WO2024051788A1 - 光波导结构及其制作方法、光学组件和近眼显示设备 - Google Patents

光波导结构及其制作方法、光学组件和近眼显示设备 Download PDF

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Publication number
WO2024051788A1
WO2024051788A1 PCT/CN2023/117571 CN2023117571W WO2024051788A1 WO 2024051788 A1 WO2024051788 A1 WO 2024051788A1 CN 2023117571 W CN2023117571 W CN 2023117571W WO 2024051788 A1 WO2024051788 A1 WO 2024051788A1
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WO
WIPO (PCT)
Prior art keywords
grating
layer
waveguide
optical waveguide
optical
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2023/117571
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English (en)
French (fr)
Inventor
丁武文
孙鹏
朱璐璐
杨健晗
赵骁宇
刘琦
邓焯泳
蒋珺楠
鲁云开
郭艳君
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Filing date
Publication date
Application filed by Huawei Technologies Co Ltd filed Critical Huawei Technologies Co Ltd
Priority to EP23862482.9A priority Critical patent/EP4575610A4/en
Publication of WO2024051788A1 publication Critical patent/WO2024051788A1/zh
Priority to US19/073,571 priority patent/US20250208424A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01Head-up displays
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/11Anti-reflection coatings
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/0018Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 with means for preventing ghost images
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01Head-up displays
    • G02B27/017Head mounted
    • G02B27/0172Head mounted characterised by optical features
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01Head-up displays
    • G02B27/017Head mounted
    • G02B27/0176Head mounted characterised by mechanical features
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/10Beam splitting or combining systems
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/10Beam splitting or combining systems
    • G02B27/12Beam splitting or combining systems operating by refraction only
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/10Beam splitting or combining systems
    • G02B27/12Beam splitting or combining systems operating by refraction only
    • G02B27/126The splitting element being a prism or prismatic array, including systems based on total internal reflection
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0013Means for improving the coupling-in of light from the light source into the light guide
    • G02B6/0015Means for improving the coupling-in of light from the light source into the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/0016Grooves, prisms, gratings, scattering particles or rough surfaces
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0013Means for improving the coupling-in of light from the light source into the light guide
    • G02B6/0023Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
    • G02B6/0026Wavelength selective element, sheet or layer, e.g. filter or grating
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033Means for improving the coupling-out of light from the light guide
    • G02B6/005Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0065Manufacturing aspects; Material aspects
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/10Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24Coupling light guides
    • G02B6/26Optical coupling means
    • G02B6/262Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24Coupling light guides
    • G02B6/26Optical coupling means
    • G02B6/34Optical coupling means utilising prism or grating
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00Printed circuits
    • H05K1/02Details
    • H05K1/0277Bendability or stretchability details
    • H05K1/028Bending or folding regions of flexible printed circuits
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/10Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
    • G02B6/12Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
    • G02B2006/12035Materials
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/10Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
    • G02B6/12Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
    • G02B2006/12083Constructional arrangements
    • G02B2006/12107Grating
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01Head-up displays
    • G02B27/0101Head-up displays characterised by optical features
    • G02B2027/0112Head-up displays characterised by optical features comprising device for genereting colour display
    • G02B2027/0114Head-up displays characterised by optical features comprising device for genereting colour display comprising dichroic elements
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01Head-up displays
    • G02B27/0149Head-up displays characterised by mechanical features
    • G02B2027/015Head-up displays characterised by mechanical features involving arrangement aiming to get less bulky devices
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01Head-up displays
    • G02B27/017Head mounted
    • G02B27/0172Head mounted characterised by optical features
    • G02B2027/0174Head mounted characterised by optical features holographic
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01Head-up displays
    • G02B27/017Head mounted
    • G02B2027/0178Eyeglass type
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/10Beam splitting or combining systems
    • G02B27/14Beam splitting or combining systems operating by reflection only
    • G02B27/149Beam splitting or combining systems operating by reflection only using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes

Definitions

  • the optical waveguide structure can be a grating structure, a coupling grating, an optical waveguide structure with a grating structure, etc.
  • the optical component can be an optical machine, a light combining unit, an optical component having a light machine and a light combining unit, etc.
  • Near-to-eye display also known as head-mounted display or wearable display
  • head-mounted display or wearable display can create virtual images in the field of view of one eye or both eyes.
  • Near-to-eye display displays to people through a display device placed within the non-photopic distance of the human eye.
  • the technology uses the eye to render light field information and then reconstruct the virtual scene in front of the eyes.
  • Augmented reality (AR) technology is a new technology that "seamlessly" integrates real world information and virtual world information. It integrates entity information that is difficult to experience within a certain time and space in the real world (such as : visual information, three-dimensional appearance, sound, taste, touch, etc.), through optics, computers, electronics, etc., simulated and then superimposed, not only showing the real world information, but also displaying the virtual information at the same time, two kinds of information Complement and superimpose each other.
  • visual augmented reality users use optical display devices to combine the real world with virtual images to form an immersive visual experience that combines reality and reality.
  • AR can realize many functions and can be regarded as a miniature mobile phone. It can determine the user's state by tracking the trajectory of the eye's gaze and enable corresponding functions.
  • Near-eye display technology products (such as AR glasses) are developing in the direction of being lighter, thinner, and more portable. At the same time, the content rendered by near-eye display devices is also required to be more comfortable, more realistic, and smoother. Therefore, for near-eye display devices, the industry design development trends are: lightweight design, thin and small-size design, improved optical display effect, etc.
  • the present application provides an optical waveguide structure and its manufacturing method, optical components and near-eye display equipment.
  • the optical waveguide structure can be a grating structure, a coupling grating, an optical waveguide structure with a grating structure, etc.
  • the optical component can be an optical waveguide structure.
  • Machines, light combining units, optical components with light machines and light combining units, etc. can achieve lightweight, thin and small size near-eye display devices, and improve optical display effects.
  • a light combining unit for use in an optical machine of a near-eye display device.
  • the light combining unit includes a first prism unit, a second prism unit, a third prism unit and a fourth prism unit.
  • the first prism unit and the third prism unit have a pentahedral structure
  • the second prism unit and the fourth prism unit have a tetrahedral structure
  • the third prism unit and the fourth prism unit are spliced to form a hexahedral structure.
  • the butt position between the first prism unit and the second prism unit is the first surface.
  • the third prism unit and the fourth prism unit are spliced to form a hexahedral structure.
  • the joint position between the prism units is the second surface
  • the joint position between the first prism unit and the fourth prism unit is the third surface
  • the joint position between the second prism unit and the third prism unit is
  • the docking position is the fourth side
  • the first side and the second side are provided with a first dichroic film
  • the third side and the fourth side are provided with a second dichroic film
  • the wavelength range of the light reflected by the second dichroic film is different.
  • the first surface and the second surface constitute the first diagonal surface of the hexahedral structure.
  • the third surface and the fourth surface constitute the hexahedron.
  • the second diagonal surface of the structure, the intersection line between the first diagonal surface and the second diagonal surface is the body diagonal of the hexahedral structure.
  • the first prism unit and the third prism unit among the four prism units in the light combining unit are designed as a pentahedral structure
  • the second prism unit and the fourth prism unit among the four prism units are designed as a tetrahedral structure.
  • these four prism units can be spliced to form a hexahedral structure by setting light splitting films on the first diagonal surface and the second diagonal surface, and the intersection line between the first diagonal surface and the second diagonal surface is as described
  • the body diagonal of the hexahedral structure allows the light combining unit to match the light-emitting unit more flexibly. That is, the display screens of the light-emitting unit have more placement options and are more flexible.
  • the first prism unit, the second prism unit, the third prism unit and the fourth prism unit are all integrated prism structures.
  • This embodiment provides a light combining unit composed of four prisms, which has a simple structure and is compatible with the light emitting unit. Meta-configuration still has the advantage of flexibility.
  • the first dichroic film is used to reflect light in a first wavelength range and transmit light in a second wavelength range and a third wavelength range
  • the second dichroic film is used to reflect light in a second wavelength range.
  • the light in the wavelength range transmits the light in the first wavelength range and the light in the third wavelength range.
  • the first dichroic film is used to reflect light in the second wavelength range and transmit light in the first wavelength range and light in the third wavelength range
  • the second dichroic film is used to reflect the light in the third wavelength range.
  • the first prism unit includes a first sub-prism and a second sub-prism, and the butt position between the first sub-prism and the second sub-prism is the first sub-surface;
  • the second prism unit includes a third sub-prism and a fourth sub-prism, and the butt position between the third sub-prism and the fourth sub-prism is the second sub-surface;
  • the third prism unit includes a fifth sub-prism and a sixth sub-prism, the joint position between the fifth sub-prism and the sixth sub-prism is the third sub-surface;
  • the fourth prism unit includes a seventh sub-prism and an eighth sub-prism, the third sub-prism The joint position between the seventh sub-prism and the eighth sub-prism is the fourth sub-surface;
  • the first sub-surface, the second sub-surface, the third sub-surface and the fourth sub-surface constitute the The third diagonal surface of the hexahedral structure, the intersection line between the third diagonal surface and the first diagonal surface
  • This embodiment provides a light combining unit composed of eight prisms. Compared with the four-prism structure, this solution has a more flexible solution for matching with the light-emitting units. This solution can realize the configuration of more light-emitting units, so that the light There are more application solutions for the machine, and you can choose the appropriate configuration of the light-emitting unit according to the specific design needs, with better flexibility.
  • both the first sub-prism and the second sub-prism are pentahedral prisms; one of the third sub-prism and the fourth sub-prism is a tetrahedral prism, and the other one is a tetrahedral prism. It is a pentahedral prism; the fifth sub-prism and the sixth sub-prism are both pentahedral prisms; one of the seventh sub-prism and the eighth sub-prism is a tetrahedral prism, and the other is a pentahedral prism. prism.
  • This solution defines the specific shape of each prism in the light combining unit composed of eight prisms. This application provides the light combining unit with the advantage of flexibly arranging light emitting units through the arrangement of prisms of different shapes.
  • a third dichroic film is provided on the third diagonal surface, and the third dichroic film, the first dichroic film and the second dichroic film are respectively used to reflect light in different wavelength ranges. light.
  • This plan limits the arrangement of the light splitting films in the light combining unit composed of eight prisms.
  • the light combining unit has flexibility. Advantages of arranging lighting units.
  • the second light-splitting film and the third light-splitting film each include four sub-films, and the first light-splitting film has an integrated structure.
  • This plan limits the specific structures of the second light-splitting film and the third light-splitting film, and the plan that the first light-splitting film has an integrated structure.
  • the light-splitting film designed in this plan is used in a light combining unit composed of eight prisms. Since The first light-splitting film can have an integrated structure, which has the advantages of simple structure and convenient assembly.
  • the second light-splitting film includes two sub-films, and the first light-splitting film has an integrated structure.
  • the dichroic film designed in this solution is used in a light combining unit composed of four prisms. Since the first dichroic film can be an integrated structure, it has the advantages of simple structure and easy assembly.
  • the first light-splitting film is a reflective green-transparent red-blue film layer
  • the second light-splitting film is a reflective blue-transparent red-green film layer
  • the third light-splitting film is a reflective red-transparent blue-green film. film layer.
  • the hexahedral structure is a cube.
  • the design of the cubic structure allows the light paths of light sources of different colors in the light-emitting unit (i.e., the first wavelength range emission unit, the second wavelength range emission unit, and the third wavelength range emission unit) to remain consistent from the light incident surface to the light exit surface. That is, the lengths of the transmission paths of the red light emitted by the first wavelength range emitting unit, the blue light emitted by the second wavelength range emitting unit, and the green light emitted by the third wavelength range emitting unit in the light combining unit are the same.
  • the transmission path of light is the optical path, and the optical path is the same, which is beneficial to ensuring the clarity of optical-mechanical imaging. If the optical path of a certain color of light is inconsistent with the optical path of other colors of light, the clarity of the image projected by the light machine will be poor and the image will be blurry.
  • an optical machine including a light-emitting unit, an optical imaging unit, and a light-combining unit provided in any possible implementation manner in the first direction.
  • the light-combining unit is used to emit light from the light-emitting unit.
  • the monochromatic light is combined, and the optical imaging unit is located on the light exit side of the light combining unit. Since the optical machine provided by this application includes the light combining unit described in the first aspect, the optical machine has a more flexible configuration scheme, so that the optical machine can be configured in more environments in near-eye display devices.
  • the structure of the optical machine can be more compact, which is beneficial to saving space.
  • the light emitting unit includes a first wavelength range emitting unit, a second wavelength range emitting unit and a third wave Long range emission unit, the first wavelength range emission unit is facing the first light incident surface of the hexahedral structure of the light combining unit, and the second wavelength range emission unit is facing the said light combining unit
  • the second light incident surface of the hexahedral structure, the third wavelength range emission unit is facing the third light incident surface of the hexahedral structure of the light combining unit, the first light incident surface, the second light incident surface
  • the surface and the third light incident surface are arranged perpendicularly adjacent to each other, and the normal direction of the light emitting surface of the first wavelength range emitting unit and the normal direction of the light emitting surface of the second wavelength range emitting unit are both vertical.
  • the normal direction of the light-emitting surface of the third wavelength range emitting unit is the same as the optical axis direction of the optical imaging unit of the optical machine.
  • This solution provides a specific solution in which each light incident surface of the light emitting unit and the light combining unit is arranged correspondingly.
  • the light emitting unit includes a first wavelength range emitting unit, a second wavelength range emitting unit and a third wavelength range emitting unit, and the light emitting surface of the first wavelength range emitting unit faces the combination.
  • the first light incident surface of the hexahedral structure of the light unit, the light emitting surface of the second wavelength range emitting unit is facing the second light incident surface of the hexahedral structure of the light combining unit, and the third wavelength range
  • the light-emitting surface of the emitting unit faces the third light-incident surface of the hexahedral structure of the light-combining unit, the first light-incident surface and the second light-incident surface are parallel to each other, and the third light-incident surface is vertical
  • the normal direction of the light-emitting surface of the first wavelength range emission unit, the normal direction of the light-emitting surface of the third wavelength range emission unit and the normal direction of the second wavelength range emission unit The normal direction of the light-emitting
  • the area of the light incident surface of the light combining unit is larger than the area of the light emitting surface of the corresponding light emitting unit. This can ensure that more light emitted by the light emitting unit enters the light combining unit and improves the efficiency of light transmission.
  • a near-eye display device including a structural member and a lens.
  • the structural member includes a temple and a frame.
  • the temple is connected to the frame, and the lens has an optical waveguide.
  • the lens is fixed on the frame, and the near-eye display device includes the optical engine provided by any possible implementation of the second aspect, and the optical engine is fixed to the structural member.
  • This solution provides a near-eye display device. Since it includes the optical engine described in the second aspect, the near-eye display device has more design solutions and the position arrangement of the optical engine is flexible. Moreover, since the structure of the optical machine can be more compact, it is conducive to saving space and miniaturizing the size of the near-eye display device.
  • the near-eye display device is provided with a controller
  • the light-emitting unit includes a first flexible circuit board, a second flexible circuit board and a third flexible circuit board
  • the first flexible circuit board is electrically connected to Between the first wavelength range transmitting unit and the controller, the second flexible circuit board is electrically connected between the second wavelength range transmitting unit and the controller, and the third flexible circuit board Electrically connected between the third wavelength range transmitting unit and the controller, at least one of the first flexible circuit board, the second flexible circuit board and the third flexible circuit board has no bending shape Extend along the structural member.
  • At least one of the flexible circuit boards of the optical machine does not need to be folded, that is, it extends along the structural member without bending, which is beneficial to reducing the size of the entire machine. It is understandable that if the flexible circuit board is folded, the overall size of the optical machine will become larger due to the folding of the flexible circuit board, which will take up more space in a near-eye display device.
  • the optical machine is fixed to the temple leg, and at least one of the first flexible circuit board, the second flexible circuit board and the third flexible circuit board has no bending shape.
  • one outer surface of the hexahedral structure of the light combining unit is a non-light incident surface, and the non-light incident surface is adjacent to the light exit surface of the light combining unit.
  • the non-light incident surface The surface faces the inner side of the temple legs, and the inner side of the temple legs is used to be close to the human face.
  • Such a setting can also ensure that the near-eye display device does not have a light-emitting unit on the side close to the face, reducing the risk of users sensing heat and improving the user experience.
  • the application provides an optical component including an optical machine and an optical waveguide.
  • the optical waveguide includes a waveguide base and a coupling grating.
  • the waveguide base includes a slope, and the slope is located between the coupling grating and the waveguide.
  • the position where the substrate is coupled is either located on the light incident side of the coupling position of the coupling grating and the waveguide substrate.
  • the coupling grating is used to receive the light of the optical machine.
  • the inclined surface faces the optical machine. The light The machine has an optical axis, and the direction perpendicular to the optical axis is the first direction.
  • the angle between the inclined plane and the first direction is greater than or equal to half of the field of view of the optical machine, so that The edge light of the field of view of the optical machine reflected by the coupling grating can deflect from the optical machine.
  • the optical component provided by this application through the structural design of the optical waveguide, specifically, through the design of the light input position of the optical waveguide, causes the light reflected at the grating position to deviate from the optical machine, that is, the light reflected at the grating position is coupled to The direction will be outside the optical effective area of the optical engine and will not return to the optical engine. This allows the optical components to obtain better image display efficiency and solves the problem of ghost images.
  • the angle between the slope and the first direction is greater than or equal to half of the field of view of the optical machine, so that the viewing angle of the optical machine reflected by the coupling grating is Edge rays at the field angle can deflect off the optical machine.
  • the field of view of the optical machine is a horizontal field of view or a vertical field of view.
  • This application defines that the field of view of the optical machine can be a horizontal field of view or a vertical field of view.
  • any field of view can be used to obtain a suitable angle. This reflects the more flexible aspect of this program design.
  • the optical axis of the optical machine is the central axis of the effective optical zone of the optical machine. It can be understood that this plan proposes
  • the optical engine provided is a non-off-axis optical axis system, and the central axis of the optical effective area is the optical axis, which provides convenience for the design of the optical engine.
  • the waveguide base is an integrally formed structure
  • the slope is a structure formed by removing part of the material from the waveguide base.
  • the coupling grating is formed on the inclined surface, the angle between the light reflected by the coupling grating and the optical axis is a second angle, and the light incident on the coupling grating
  • the angle between the edge ray of the field of view of the optical machine on the grating and the optical axis is a first angle, and the second angle is greater than the first angle.
  • This solution defines a solution for a slope obtained by removing material, and defines a specific solution for the coupling grating to be located on the slope.
  • This solution uses the inclined surface and the setting of the coupling grating to form an inclined state between the setting angle of the coupling grating and the main plane of the waveguide substrate.
  • the optical component provided by this embodiment does not have the phenomenon that the reflected light coupled out of the grating enters the optical machine and is reflected again to form a ghost image.
  • the waveguide substrate includes a main plane, the inclined plane is inclined relative to the main plane, the coupling grating is formed on the main plane, and in the extension direction of the optical axis, the The inclined plane is located between the coupling grating and the optical machine.
  • the edge light of the field of view of the optical machine is incident on the coupling grating through the inclined plane, and the light reflected by the coupling grating is The edge rays of the field of view of the optical machine are deflected out of the optical machine through the inclined plane.
  • This solution defines a solution of a slope obtained by removing material, and a solution in which the coupling grating is located on the main plane of the waveguide substrate.
  • the optical component provided by this embodiment does not have the phenomenon that the reflected light coupled out of the grating enters the optical machine and is reflected again to form a ghost image.
  • the coupling grating is formed on the main plane of the waveguide substrate. Since the main plane is the overall planar outer surface of the waveguide substrate, the manufacturing process of the coupling grating has the advantage of being easy to manufacture, and both the design and process steps are Advantages. Although the manufacturing process of the coupling grating on the inclined surface is challenging, the optical path between the coupling grating and the optical machine is relatively simple, making it easy to control the light transmission efficiency.
  • the waveguide substrate includes a waveguide main structure and an additional structure
  • the additional structure is fixed to a surface of the waveguide main structure facing the optical machine
  • the slope is formed on the additional structure. on the surface of the additional structure facing away from the main waveguide structure.
  • the coupling grating is formed on the inclined surface, and the light incident from the coupling grating enters the main waveguide structure after passing through the additional structure, and the light reflected by the coupling grating
  • the angle between the light ray and the optical axis is the second angle
  • the angle between the edge ray of the field of view of the optical machine incident on the coupling grating and the optical axis is the first angle.
  • the second angle is greater than the first angle.
  • the waveguide main structure includes a main plane, the inclined plane is inclined relative to the main plane, the coupling grating is formed on the main plane, and in the extension direction of the optical axis, The inclined plane is located between the coupling grating and the optical machine.
  • the edge rays of the field of view of the optical machine enter the additional structure and the waveguide conductor structure through the inclined plane and are incident on the coupling grating.
  • the edge rays of the optical machine's field of view reflected by the coupling grating pass through the waveguide main structure and the additional structure and emerge from the inclined surface and deflect out of the optical machine.
  • This solution limits the specific position of the coupling grating in the solution of arranging additional structures combined with the waveguide substrate.
  • This solution sets the coupling grating on the main plane of the waveguide substrate, because the main plane is the entire waveguide substrate.
  • the planar outer surface has the advantage of being easy to manufacture for the manufacturing process of the coupling grating, and has advantages in both design and process steps.
  • the material of the additional structure is the same as the material of the main waveguide structure.
  • this solution can obtain an additional structure with the same or similar refractive index as the waveguide main structure, to ensure that the light incident on the waveguide base is transmitted consistently in the additional structure and the waveguide main structure, and to avoid problems caused by different refractive indexes.
  • the deflection of light affects the diffraction efficiency or the required angle of incident light cannot be obtained. Therefore, this application can ensure the optical performance of the optical waveguide by limiting the refractive index and material of the additional structure to be consistent with the waveguide substrate.
  • the refractive index of the additional structure is the same as the refractive index of the main waveguide structure.
  • the additional structure may be a high-fold substrate material.
  • the refractive index defined in this application is the same, and the "same” can be understood to mean exactly the same, with a small tolerance, or to be approximately the same, as long as the angle of the incident light is within the design requirements.
  • the additional structure and the waveguide main structure are bonded by optical glue, and the refractive index of the optical glue is the same as the refractive index of the additional structure and the waveguide main structure.
  • This plan defines the specific connection method between the additional structure and the main structure of the waveguide, and constrains the refractive index of the optical glue, so that the refractive index of the waveguide substrate of the optical waveguide is consistent, and avoids light deflection affecting diffraction due to different refractive indexes. Efficiency or inability to obtain the required angle of incident light.
  • the position of the bevel on the additional structure is polished to improve the light transmittance.
  • the additional structure and the waveguide main structure are combined through intermolecular bonding.
  • This plan defines a specific connection method between the additional structure and the waveguide main structure. Through molecular bonding, the use of other media connections, such as optical glue, can be avoided.
  • the connection between the additional structure and the waveguide main structure obtained by this plan is The combination is more direct, which helps to ensure that the refractive index of the optical waveguide substrate is consistent, and avoids the deflection of light due to different refractive indexes that affects the diffraction efficiency or the required angle of incident light.
  • the present application provides a near-eye display device, including a structural member and the optical component provided in any possible implementation manner of the fourth aspect, and the optical component is installed on the structural member.
  • the near-eye display device provided by this solution solves the problem of ghost images due to the design of optical components and obtains superior image display effects.
  • the optical engine in the optical assembly provided in the fourth aspect of the application may also include the light combining unit provided in any possible implementation manner of the first aspect of the application.
  • optical machine in the optical assembly provided in the fourth aspect of the present application is also the optical machine provided by any possible implementation of the second aspect of the present application.
  • the near-eye display device provided in the fifth aspect of the application may include: a light combining unit provided by any possible implementation of the first aspect of the application, and/or a light combining unit provided by any possible implementation of the second aspect of the application. machine.
  • the near-eye display device provided in the third aspect of this application may include the optical component provided in any possible implementation manner of the fourth aspect of this application.
  • the present application provides an optical waveguide that can solve the problems of light waste and uneven light.
  • the optical waveguide includes a coupling grating and a coupling grating.
  • the coupling grating is used to couple the light into the optical waveguide and perform total reflection in the optical waveguide.
  • the coupling grating is used to couple the light out.
  • the coupling grating includes a first region and a second region, the first region is located on the light incident side of the second region along the first direction, and the first region includes a first sub-region and a second sub-region, The first sub-region and the second sub-region are arranged along a second direction, the second direction intersects the first direction, and the grating types in the first sub-region and the second sub-region are both It is a one-dimensional grating, the second region is used to couple out light, the grating type of at least part of the grating in the second region is a two-dimensional grating, the central axis of the second region extends and passes through the coupling grating, the first sub-region and the second sub-region are distributed on both sides of the central axis.
  • This application uses the one-dimensional grating in the first area to transmit most of the energy of the light to the second area, which can improve the efficiency of light propagation, improve the uniformity of light, and can reduce the difficulty of processing and production and
  • both the first sub-region and the second sub-region are in contact with the second region. It can also be understood that there is no gap between the first sub-region and the second sub-region and the second region.
  • the grating in the second region has continuity, which can improve the light coupling efficiency.
  • a first spacing area is formed between the first sub-region and the second area
  • a second spacing area is formed between the second sub-region and the second area.
  • the extension size of the first spacing area along the first direction is less than or equal to 4 mm, and the extension size of the second spacing area along the first direction is less than or equal to 4 mm.
  • This solution limits the size of the first spacing area and the second spacing area along the first direction, which is beneficial to ensuring the utilization of light and the intensity of the coupled light.
  • the center of the coupling grating is located on the central axis of the second area. This solution limits the relationship between the central axis of the second region and the coupling grating, that is, the connection between the center of the second region and the center of the coupling grating can be considered as the central axis.
  • the first sub-region and the second sub-region are distributed mirror-symmetrically with the central axis as the center. This solution constrains the relationship between the first sub-region and the second sub-region and the central axis, and uses a mirror-symmetric design to make the energy of the light coupled out of the second region of the grating more balanced.
  • the first sub-region and the second sub-region have different areas. This solution can adjust the specific size and shape of the first sub-region and the second sub-region according to specific needs, making the optical waveguide have a wider range of application scenarios.
  • the connecting direction between the center of the first sub-region and the center of the second sub-region is the direction of the second sub-region. direction, the angle between the second direction and the central axis is less than 90 degrees.
  • the specific structural form of the first sub-region and the second sub-region in the first region changes, but the first sub-region and the second sub-region can still achieve constraint
  • the propagation direction of the light beam plays a role in improving the efficiency of light propagation.
  • the grating line extending direction of the one-dimensional grating in the first sub-region is the first grating line direction
  • the grating line extending direction of the one-dimensional grating in the second sub-region is the second grating line direction.
  • the two-dimensional grating in the second area includes a first grating line and a second grating line that are arranged to intersect.
  • the extending direction of the first grating line is the direction of the first grating line.
  • the extension direction of the grid line is the second grid line direction.
  • the extending direction of the first raster line is substantially the same as the direction of the first raster line
  • the extending direction of the second raster line is substantially the same as the direction of the second raster line, so that the image information transmitted by the optical waveguide has authenticity. There will be no distortion of the image, ensuring the image display effect.
  • the distribution period of the one-dimensional grating in the first sub-region is the same as the distribution period of the first grating line; and/or the distribution period of the one-dimensional grating in the second sub-region is the same.
  • the distribution period is the same as the distribution period of the second gate line.
  • the angle between the first grid line direction and the second grid line direction is 60 degrees.
  • This solution can constrain the propagation direction of light by making the angle between the first grating line direction and the second grating line direction 60 degrees, so that the propagation direction of the light matches the grating line direction of the two-dimensional grating in the second area 122, so that It can ensure that more light is coupled out and achieve higher light efficiency.
  • the first sub-region and the second sub-region are in contact.
  • the one-dimensional grating in the first sub-area is connected to the one-dimensional grating in the second sub-area, which can improve the efficiency of light transmission.
  • a third spacing area is formed between the first sub-region and the second sub-region.
  • the size of the third spacing area extending along the second direction is less than or equal to the maximum radial size of the coupling grating.
  • all grating types in the second area are two-dimensional gratings.
  • the second area provided by this solution has the advantages of simple structure and easy production.
  • the second area includes N two-dimensional areas and N-1 one-dimensional areas, N ⁇ 2, and the N-1 one-dimensional areas are respectively located in two adjacent areas. Between the two-dimensional areas, one of the two-dimensional areas is adjacent or adjacent to the first area, the grating type in the one-dimensional area is a one-dimensional grating, and the grating type in the two-dimensional area is a two-dimensional grating. .
  • the second area by arranging a two-dimensional grating and a one-dimensional grating in the second area, and arranging the one-dimensional grating in the middle of the two-dimensional grating, it is conducive to regulating the intensity of the coupled light and making the entire picture more uniform.
  • the light intensity of a part adjacent to the first area is greater than the light intensity of a part far away from the first area.
  • One-dimensional areas are set between adjacent two-dimensional areas.
  • the one-dimensional grating in the one-dimensional area can weaken the light intensity at the position of the one-dimensional area.
  • the one-dimensional grating in the one-dimensional area can constrain The light propagation direction makes the light propagate concentratedly to the two-dimensional area on the light exit side of the one-dimensional area. This can enhance the light intensity in the two-dimensional area. Therefore, overall, it can ensure that the intensity of the coupled light in the second area is uniform. sex.
  • the one-dimensional area includes a third sub-region and a fourth sub-region, the third sub-region and the fourth sub-region are arranged along the second direction and distributed in the both sides of the axis.
  • the grating line direction of some gratings in the two-dimensional area is the same as the grating line direction of the grating in the third sub-area, and the grating line direction of some gratings in the two-dimensional area is the same.
  • the direction of the grating lines is the same as that of the grating in the fourth sub-region.
  • the present application provides a near-eye display device, including an optical machine and an optical waveguide provided by any possible implementation of the sixth aspect, where the optical machine is located on the light incident side of the coupling grating.
  • the near-eye display device provided by this solution adopts the optical waveguide described in the sixth aspect, so that the effect of the virtual image generated by the near-eye display device is better, and the light intensity and light uniformity are optimized.
  • the near-eye display device provided in the seventh aspect of the application may include any one of the following solutions or a combination of solutions: the light combining unit provided by any possible implementation of the first aspect of the application, any possible implementation of the second aspect of the application.
  • the near-eye display device provided in the fifth aspect of the present application may include: the light wave provided by any possible implementation manner of the sixth aspect of the present application. guide.
  • the near-eye display device provided in the third aspect of this application may include: the optical waveguide provided in any possible implementation manner of the sixth aspect of this application.
  • the application provides an optical waveguide, including a coupling grating.
  • the coupling grating includes a plurality of sub-gratings arranged at intervals.
  • the spacing between two adjacent sub-gratings is L, 3mm ⁇ L ⁇ 5mm, L refers to the distance between the centers of two adjacent sub-gratings, one of which is the first sub-grating, and the first sub-grating is different from other sub-gratings adjacent to the first sub-grating.
  • There are separation areas between the gratings the maximum radial size of the first sub-grating is less than or equal to 1.5 mm, and the separation areas have no grating structure.
  • the light coupled out by the sub-gratings is A thin beam can be understood as a small beam, and only one beam of light can enter the pupil, so that the beam does not fill the pupil.
  • the depth of field becomes very large. Therefore, no matter where the user focuses, the user can clearly see the virtual image when observing virtual images with different parallaxes, without having to worry about the virtual image. Where the virtual image distance of the image is actually located, thereby solving the problem that the virtual image distance of the optical waveguide is a fixed value and eliminating the VAC problem.
  • the maximum radial size of the first sub-grating is D, 0.5mm ⁇ D ⁇ 1mm.
  • This plan limits the radial size of the first sub-grating to be greater than or equal to 0.5mm, which can ensure that the first sub-grating can have the function of coupling out the grating, that is, it can couple the light in the optical waveguide to the human eye.
  • This plan limits the first sub-grating to The radial size of the sub-grating is less than or equal to 1mm, which can ensure that the light projected by the first sub-grating is a thin beam. Even if the pupil size becomes smaller due to environmental factors, the light beam projected by the first sub-grating to the pupil is still a thin beam. , cannot fill the pupil.
  • the maximum radial dimension of each of the plurality of sub-gratings is D, 0.25mm ⁇ D ⁇ 0.75mm; or, 0.75mm ⁇ D ⁇ 1.5mm.
  • This solution limits all sub-gratings to be able to couple out thin beams to solve the VAC problem.
  • the radial size range of each of the sub-gratings is smaller, specifically as follows: :0.25mm ⁇ D ⁇ 0.75mm.
  • the radial size range of each of the sub-gratings is larger, specifically as follows: :0.75mm ⁇ D ⁇ 1.5mm.
  • 3.5mm ⁇ L ⁇ 4.5mm In one possible implementation, 3.5mm ⁇ L ⁇ 4.5mm.
  • the range of spacing between two adjacent sub-gratings defined in this embodiment can meet various application environments and different application scenarios, and it is easier to ensure that the light coupled out by the sub-gratings is a thin beam.
  • the plurality of sub-gratings are arranged in an array of multiple rows and multiple columns, and the array arrangement has the same row spacing and the same column spacing.
  • This solution defines a specific sub-grating array arrangement solution, which can solve the VAC problem.
  • the plurality of sub-gratings are arranged in multiple rows, and the arrangement direction of the sub-gratings in each row is a first direction.
  • the odd-numbered rows and even-numbered rows in the multiple rows of sub-gratings are arranged in staggered positions.
  • the direction is perpendicular to the first direction, and in the second direction, the sub-gratings of the odd-numbered rows face the separation area between the two adjacent sub-gratings of the even-numbered rows.
  • This embodiment provides a honeycomb array arrangement scheme, which has the following advantages: this scheme can ensure that the relative distance of each thin beam at the eye movement space position is a constant value, while the spacing between each thin beam in the orthogonal array arrangement scheme is The hypotenuse direction is slightly larger than the horizontal and vertical directions.
  • this solution when the human eye moves within the eye movement space, such as when the eye rotates or the glasses slide, different thin light beams entering the pupil of the human eye will change. Due to the honeycomb-like arrangement of each The relative distance of the fine grating is constant. Since the human eye is displaced relative to the eye movement space, the energy of the beam entering the human eye can be guaranteed to be equal. Therefore, the changes in the image will be flatter, which can improve the user experience of near-eye display devices.
  • the spacing between any two adjacently arranged sub-gratings is equal.
  • uniformity of the outcoupled light can be achieved.
  • the outer contour shape of the sub-grating is a circle, a square, or a hexagon.
  • each of the sub-gratings includes grating microstructures arranged in a preset period, and the preset period is 200-500 nm.
  • the specific shape of the grating microstructure can be but is not limited to: hexagon, parallelogram, triangle, trapezoid, etc.
  • the sub-grating due to the arrangement of the grating microstructure, the sub-grating can couple out the light in the optical waveguide and project it to the human eye.
  • a plurality of the sub-gratings are coplanar, that is, the plurality of sub-gratings are arranged on the same surface of the waveguide substrate.
  • one of the two adjacent sub-gratings is located on the front side of the waveguide substrate of the optical waveguide, and the other of the two adjacent sub-gratings is located on the reverse side of the waveguide substrate,
  • the center of the sub-grating located on the front side of the waveguide substrate is center one
  • the vertical projection of the center of the sub-grating located on the back side of the waveguide substrate on the front side of the waveguide substrate is center two
  • the adjacent The spacing between the two sub-gratings is the distance between the center one and the center two.
  • the optical waveguide includes a waveguide substrate, a coupling grating, a relay grating and the coupling-out grating, the relay grating is located between the coupling-in grating and the coupling-out grating, so
  • the coupling-out grating includes a first sub-grating region and a second sub-grating region, and the distance between the first sub-grating region and the relay grating is less than the distance between the second sub-grating region and the relay grating, so
  • the height of the sub-grating in the first sub-grating area is smaller than the height of the sub-grating in the second sub-grating area.
  • the coupling grating includes a first edge and a second edge, the first edge is an edge of the coupling grating adjacent to the relay grating, and the second edge is the The coupling grating is away from the edge of the relay grating, and the height of the sub-grating increases gradually from the first edge to the second edge.
  • this application provides a near-eye display device, including an optical machine and an optical waveguide provided by any possible implementation of the eighth aspect, where the optical waveguide is used to receive light projected by the optical machine.
  • the near-eye display device provided by this solution uses the optical waveguide described in the eighth aspect, which can solve the VAC problem and improve the image display effect of the near-eye display device.
  • the present application provides a near-eye display device, including an optical waveguide, a control unit, a pupil detection component, and a grating adjustment component.
  • the optical waveguide includes a coupling grating
  • the coupling grating includes a plurality of sub-gratings, and a plurality of so-called gratings.
  • the sub-grating array is arranged, the maximum radial size of each sub-grating is D, D ⁇ 1.5mm, the spacing between two adjacent sub-gratings is L', D ⁇ L' ⁇ 4mm, L' refers to is the distance between the centers of two adjacent sub-gratings;
  • the pupil detection component is used to detect the size of the pupil, and the control unit is used to receive the signal of the pupil detection component and drive the grating
  • the grating adjusting member is used to control part of the sub-gratings of the coupling grating to open or close, so that part of the sub-gratings is in a working state, and the two adjacent sub-gratings in the working state are
  • the spacing between gratings is L, 3mm ⁇ L ⁇ 5mm, and L refers to the distance between the centers of two adjacent sub-gratings in the working state.
  • the array of sub-gratings set up in this solution is arranged in a dense manner, and the distance between adjacent sub-gratings can be zero. That is to say, the sub-gratings can be arranged in such a way that they are in contact with each other one by one. Gaps can also be set between gratings.
  • This solution uses an arrangement scheme in which the spacing between two adjacent sub-gratings is L', and is combined with a grating adjustment member to realize opening of part of the sub-gratings, so that in the sub-grating array in the working state, the adjacent sub-gratings in the working state
  • the range of the distance L between the centers is: 3mm ⁇ L ⁇ 5mm.
  • This solution uses switchable optical elements.
  • the working sub-grating can respond to pupils of different sizes. For example, when the pupil size changes, the grating adjustment member can be used to adjust the working state of the sub-grating. spacing to improve image display efficiency. This solution does not need to switch the virtual image distance according to the actual content, and can reduce system power consumption.
  • the near-eye display device provided by the ninth and tenth aspects of the application may include any one of the following solutions or a combination of solutions: the light combining unit provided by any possible implementation of the first aspect of the application, any of the light combining units provided by the second aspect of the application An optical machine provided by one possible implementation, an optical component provided by the fourth aspect of this application, and an optical waveguide provided by any possible implementation of the sixth aspect.
  • the near-eye display devices provided in the third, fifth, and seventh aspects of this application may all include the optical waveguide provided in any possible implementation manner of the eighth aspect.
  • the present application provides an optical waveguide, including a waveguide substrate and a grating structure formed on the waveguide substrate.
  • the grating structure includes a plurality of core structures and a film structure. The refractive index of the film structure and the The refractive index of the core structures is different.
  • a plurality of the core structures are arranged at intervals along the vector direction of the grating structure.
  • Each of the core structures includes a connecting end, a free end and a side surface. The connecting end is connected to the waveguide substrate.
  • the free end and the connecting end are arranged oppositely in the height direction of the core structure, the side surface is connected between the connecting end and the free end, the membrane structure includes a membrane body, a first end and a second end, the membrane body covers the side of the core structure, the first end and the second end are respectively located at both ends of the membrane body, the first end The second end is connected to the waveguide substrate, the second end and the free end of the core structure are coplanar, and the free ends of all the core structures and the second end of the membrane structure jointly form The end surface of the grating structure.
  • This solution improves the diffraction efficiency and optical utilization through changes in the refractive index of the grating. Specifically, the diffraction efficiency and optical utilization are improved through the difference in refractive index between the core structure and the film structure of the grating structure.
  • the free end of the core structure and the second end of the film structure jointly form the end face of the grating structure, so that the diffraction efficiency of the grating structure is better.
  • the grating structure only has a core structure and a film structure with different refractive indexes in its vector direction.
  • the grating structure Diffraction efficiency can be guaranteed. If the free end of the core structure is covered by a film structure, part of the film structure covering the free end of the core structure will produce a diffraction effect in the height direction of the grating structure. However, the diffraction in the height direction of the grating structure is different from the vector direction of the grating structure. It will have a negative impact on the diffraction in the vector direction of the grating structure, that is, it will reduce the diffraction efficiency of the grating structure.
  • the end surface of the free end of the core structure and the end surface of the second end of the membrane structure are coplanar.
  • the end face of the free end and the end face of the second end are coplanar.
  • the membrane structure can be made by coating the core structure, and the membrane structure on the surface of the grating structure can be polished through processes such as chemical mechanical polishing (CMP). Smooth and achieve a coplanar structure.
  • CMP chemical mechanical polishing
  • the membrane structure between the adjacent core structures, includes at least three membrane layers, and at least three membrane layers are stacked on the adjacent core structures. Between the side surfaces, at least three of the film layers have different refractive indexes, and along the vector direction of the grating structure, the refractive index of at least three of the film layers exhibits a sinusoidal distribution gradient.
  • the sinusoidal graded refractive index grating provided by this solution can have higher diffraction efficiency and narrower full width at half maximum, which can meet the modulation requirements of the incident efficiency at a specific angle, thereby improving the light efficiency of the entire system.
  • the at least three film layers have different thicknesses between adjacent core structures, the film layer with the largest thickness is adjacent to the core structure, and the core structure has The thickness is greater than the thickness of the film layer with the largest thickness; or, the film layer with the smallest thickness is adjacent to the core structure, and the thickness of the core structure is smaller than the thickness of the film layer with the smallest thickness.
  • one of the film layers includes multiple layers of first sub-films and multiple layers of second sub-films arranged in alternating intervals, and the refractive index of the first sub-films is N1, The refractive index of the second sub-film is N2, and the refractive index of the film layer composed of the multi-layered first sub-film and the multi-layered second sub-film is N, N1 ⁇ N ⁇ N2.
  • This solution provides a modulation scheme for the refractive index of the film layer.
  • a film layer that meets the conditions is obtained. It has multiple manufacturing process levels and is easy to implement. The advantages.
  • part of the membrane structures between adjacent core structures has a seamless structure. It can be understood that the space between adjacent core structures is filled by the membrane structure without leaving any gaps.
  • the grating structure provided by this solution has no gaps inside, making the grating structure less susceptible to environmental factors affecting its diffraction efficiency.
  • the refractive index at any position within the core structure is the same. This solution is conducive to ensuring the stability of the diffraction efficiency of the grating structure.
  • the core structure is formed on the waveguide substrate through a nanoimprint process or an etching process, and the film structure is produced through a coating process.
  • the coating production process is easy to process in batches and can improve the production efficiency of grating structures.
  • the material of the core structure includes metal oxide.
  • the optical waveguide includes a coupling grating
  • the coupling grating includes a first coupling structure and a second coupling structure
  • the first coupling structure and the second coupling structure are arranged oppositely.
  • the first coupling structure and the second coupling structure have different grating inclination angles;
  • the grating structure is at least part of the coupling grating.
  • the first coupling structure and the second coupling structure can diffract light in different directions, so that more light is coupled into the waveguide substrate, that is, the first coupling structure and the second coupling structure are combined to achieve a large angle High diffraction efficiency within the range.
  • both the first coupling structure and the second coupling structure are the grating structures, and the refractive index of the core structure of the first coupling structure is higher than that of the second coupling structure.
  • the refractive index of the core structure of the coupling structure, the refractive index of the film structure of the first coupling structure is higher than the refractive index of the film structure of the second coupling structure.
  • One possible implementation includes a coupling grating and a coupling grating formed on the waveguide substrate, the coupling grating is the grating structure, and the coupling grating includes a first region and a second region, The first area is closer to the coupling grating than the second area, and the refractive index difference between the core structure and the film structure of the coupling grating in the first area is a first value, The refractive index difference between the core structure and the film structure of the coupling grating in the second region is a second value, and the first value is smaller than the second value.
  • This scheme is used to modulate the diffraction efficiency.
  • a possible implementation includes a relay grating, the relay grating is located between the coupling grating and the coupling grating, the relay grating is the grating structure, and the relay grating includes The third area and the fourth area, the third area is closer to the coupling grating than the fourth area, the core structure and the film of the relay grating in the third area
  • the refractive index difference between the structures is a third value
  • the refractive index difference between the core structure and the film structure of the relay grating in the fourth area is a fourth value
  • the third value is less than the fourth value
  • the fourth value is less than the first value.
  • the relay grating includes a first relay structure and a second relay structure, and the first relay structure and the second relay structure are respectively arranged on the top of the waveguide base. On the surface and the bottom surface, the first relay structure and the second relay structure have different vector directions. This scheme is used to modulate the diffraction efficiency.
  • both the first relay structure and the second relay structure are the grating structures, along the first center Following the vector direction of the structure, the refractive index difference between the core structure of the first relay structure and the film structure of the first relay structure gradually increases. This scheme is used to modulate the diffraction efficiency.
  • this application provides a near-eye display device, including an optical machine and an optical waveguide provided in any possible implementation manner of the eleventh aspect, where the optical waveguide is used to receive light projected by the optical machine.
  • the near-eye display device provided by this solution adopts the optical waveguide provided by any possible implementation method of the eleventh aspect, so that the near-eye display device can have a better image display effect.
  • the near-eye display device provided in the twelfth aspect of the application may include any one of the following solutions or a combination of solutions: the light combining unit provided by any possible implementation of the first aspect of the application, any possible implementation of the second aspect of the application.
  • the near-eye display devices provided in the third, fifth, seventh, ninth and tenth aspects of this application may all include the optical waveguide provided in any possible implementation manner of the eleventh aspect.
  • the present application provides an optical waveguide, including a coupling-in region, a coupling-out region and a light propagation region.
  • the coupling-in region is provided with a coupling grating, and the coupling grating is used to receive incident light. After the incident light enters the optical waveguide, it is totally reflected in the light propagation area.
  • the coupling-out area is provided with a coupling grating.
  • the coupling-out grating is used to couple out the light.
  • the light The waveguide includes a dielectric layer and first grating layers and second grating layers located on both sides of the dielectric layer. At least one of the first grating layer and the second grating layer has different periods, and the refractive index of the dielectric layer is less than equal to 1.5.
  • the specific implementation mode of the present application realizes the total reflection propagation of light in the light propagation area through the first grating layer and the second grating layer located on both sides of the dielectric layer.
  • a separate dielectric layer cannot Achieve total reflection propagation of light.
  • this solution can ensure that the dielectric layer has the advantage of low density and light weight, which is conducive to the lightweight design of optical waveguides.
  • This solution defines at least one of the first grating layer and the second grating layer to have different periods, so that at least one of the first grating layer and the second grating layer can transmit ambient light, and also It can completely reflect the light transmitted inside the optical waveguide.
  • the first grating layer and the second grating layer have different periods. This solution can improve the light transmittance of the optical waveguide by limiting the first grating layer and the second grating layer to have different periods.
  • both the first grating layer and the second grating layer are volume holographic gratings.
  • this solution enables the light propagation area to fully reflect the incident light entering the optical waveguide, and also has good transmittance to ambient light.
  • holographic grating has the advantage of being thin and light. Therefore, this solution is beneficial to the lightweight design of optical waveguides.
  • the optical waveguide further includes a relay grating.
  • the relay grating In the direction of optical path transmission, the relay grating is located between the coupling-in area and the out-coupling area. The light propagation area The first grating layer and the second grating layer are located between the coupling grating and the coupling grating and surround the relay grating.
  • This solution provides an optical waveguide structure with a relay grating. The location of the relay grating is not within the light propagation area. The first grating layer and the second grating layer are distributed around the relay grating.
  • the coupling grating, the coupling grating, the relay grating, the first grating layer and the second grating layer can all be volume holographic gratings.
  • the coupling-out grating is a two-dimensional grating
  • the light transmission area is located between the coupling-in grating and the coupling-out grating
  • the first grating layer and the second grating The layer fills all areas between the coupling-in grating and the coupling-out grating.
  • the conditions that the period of the coupling-out grating and the relay grating need to meet are the same as the conditions that the period of the coupling-in grating meets.
  • the coupling-in grating and the relay grating The periodic direction and size of the grating and the coupling-out grating need to form a closed k-space. Meeting this condition can ensure that the virtual image projected by the optical waveguide will not be distorted, which means the authenticity of the image can be ensured and the image display effect of the optical waveguide can be improved.
  • the optical waveguide further includes a first protective layer and a second protective layer.
  • the first protective layer is located on a side of the first grating layer facing away from the dielectric layer.
  • the first protective layer covers the first grating layer and the coupling layer.
  • the first protective layer is used to protect the first grating layer, the coupling-in grating and the coupling-out grating, so that the first grating layer, the coupling-in grating and the coupling-out grating are protected from external dust, air or water. Air erosion.
  • the second protective layer covers the surface of the second grating layer and is used to protect the second grating layer from erosion by external dust, air or water vapor, thereby ensuring the diffraction efficiency and optical performance of the optical waveguide. .
  • the optical waveguide includes a functional area and an edge area, and the coupling grating, the coupling grating and the first grating layer in the light propagation area are provided in the functional area. and the second grating layer, the refractive index of the edge area is smaller than the refractive index of the functional area.
  • the emissivity, or the material of the edge area and the material of the functional area are different.
  • the optical waveguide provided by this solution combines the functional area and the edge area.
  • the edge area can be made of lighter material, which is conducive to lightweighting the optical waveguide.
  • the period range of the first grating layer and the second grating layer is: greater than or equal to 100 nm and less than or equal to 700 nm.
  • the period corresponds to the incident angle.
  • the volume shrinkage range of the material of the first grating layer and the volume shrinkage range of the material of the second grating layer are: less than or equal to 0.1%.
  • the film thickness of the first grating layer and the second grating layer may be: >20um.
  • the bandwidth of the incident light that the first grating layer and the second grating layer cooperate with is less than 5 nm (that is, the incident light with a narrow bandwidth) to achieve total reflection propagation of the coupled light.
  • the production process of the first grating layer and the second grating layer can be obtained through multiple exposures, so that the first grating layer and the second grating layer have multiple periods, so as to achieve total reflection and propagation of incident light and enhance ambient light. transmittance.
  • the optical waveguide has a single-layer structure; or the optical waveguide has a double-layer structure; or the optical waveguide has a three-layer structure.
  • each layer has Each of the optical waveguides includes the coupling grating, the coupling grating, the first grating layer and the second grating layer.
  • This solution limits the single-layer architecture or the three-layer architecture of the optical waveguide. In either architecture, the first grating layer and the second grating layer can be used as the medium for total reflection propagation in the light propagation area. This solution is flexible. Good advantage.
  • this application provides a near-eye display device, including an optical machine and an optical waveguide provided in any possible implementation of the thirteenth aspect.
  • the light emitted by the optical machine is incident on the coupling grating to form a Incident light.
  • the bandwidth of the incident light is less than or equal to 5 nm.
  • the near-eye display device provided by this application adopts the optical waveguide provided by any possible implementation method of the thirteenth aspect, so that the near-eye display device can have the advantages of light weight and small size, and can improve the user's wearing experience.
  • the near-eye display device provided by the fourteenth aspect of the application may include any one of the following solutions or a combination of solutions: the light combining unit provided by any possible implementation of the first aspect of the application, any possible implementation of the second aspect of the application.
  • any possible implementation provides an optical waveguide.
  • the near-eye display devices provided by the third, fifth, seventh, ninth, tenth and twelfth aspects of this application may all include the optical waveguide provided by any possible implementation method of the thirteenth aspect. .
  • the present application provides an optical waveguide, including a waveguide substrate and an anti-reflective layer.
  • the anti-reflective layer is formed on the surface of the waveguide substrate.
  • the anti-reflective layer includes a volume holographic material.
  • the anti-reflective layer It includes a high refractive index phase region and a low refractive index phase region with different refractive indexes.
  • the high refractive index phase region and the low refractive index phase region are stacked on the surface of the waveguide substrate.
  • the high refractive index phase region and The low refractive index phase regions are different regions separated from each other.
  • the refractive index range of the high refractive index phase region is: 1.5-2.0.
  • the refractive index range of the low refractive index phase region is 1.1-1.5.
  • the high refractive index phase region has a refractive index range of 1.1-1.5.
  • the components in the refractive index phase region are different from the components in the low refractive index phase region.
  • This solution can reduce the haze of the volume holographic material by changing the internal structure or the arrangement of the internal components of the volume holographic material. Specifically, this solution forms the internal structure of the anti-reflection layer into alternately distributed high refractive index phase regions and low refractive index phase regions, and the high refractive index phase regions and low refractive index phase regions have different compositions. It can be understood that materials with the same components in the anti-reflection layer are gathered in a phase area. For example, the components in the high-refractive index phase area are polymers and nanoparticles, while the components in the low-refractive index phase area are polymers and nanoparticles.
  • the rate zones are alternately distributed along a direction perpendicular to the surface of the waveguide substrate.
  • the interphase distribution can be understood as the arrangement of ABABAB.
  • the low refractive index phase areas are stacked and arranged between adjacent high refractive index phase areas, or the high refractive index phase areas are stacked and arranged between adjacent low refractive index phase areas.
  • This plan defines a specific structure of the anti-reflection layer, and solves the zoning management of material components in the anti-reflection layer through the alternating distribution of high and low refractive index phase areas to avoid the formation of micro-area agglomeration, thereby allowing light to
  • the waveguide has low haze, which improves the light transmittance of the optical waveguide.
  • the main body of the volume holographic material is a high molecular polymer material
  • the main body of the high molecular polymer material is The element composition includes: one, several or all of C, H, O, N, S, P. This solution defines the specific components of the volume holographic material, making the production of the anti-reflection layer feasible.
  • the volume holographic material includes nanoparticles. This solution limits the presence of nanoparticles in the volume holographic material, and achieves zoning of different components through nanoparticles.
  • the diameter of the nanoparticles is: 1 nm to 50 nm.
  • the nanoparticles are distributed in the high refractive index phase region, and the nanoparticles distributed in the high refractive index phase region are titanium dioxide, zirconium dioxide, zinc sulfide, carbon quantum One, several or all of the points; and/or
  • Nanoparticles of different materials can be selectively distributed in the high refractive index phase area or the low refractive index phase area.
  • the volume fraction content of the nanoparticles is 0-60%.
  • This solution controls the formation of high refractive index regions and low refractive index phase regions as well as their refractive index by limiting the volume fraction of nanoparticles, and solves the problem of optical waveguide haze. Specifically, there should not be too many nanoparticles, as too many will cause the nanoparticles to agglomerate themselves and increase haze; nor should there be too few nanoparticles, which will reduce the refractive index difference between different phase regions.
  • the high refractive index phase region and the low refractive index phase region are layer structures that are laminated in sequence and arranged on the surface of the waveguide substrate.
  • the layer structure formed by the high refractive index phase region The thickness is the same as or different from the thickness of the layer structure formed by the low refractive index phase region.
  • the thickness of each of the high refractive index phase regions or the thickness of each of the low refractive index phase regions ranges from 100 nm to 1000 nm.
  • the thickness of each of the high refractive index phase regions or the thickness of each of the low refractive index phase regions is: 200 nm.
  • the optical waveguide further includes a coupling grating and a coupling grating.
  • the coupling grating and the coupling grating are both formed on the surface of the waveguide substrate.
  • the surface of the waveguide substrate is provided with There is a non-grating area, the non-grating area is the coupling grating and the area outside the coupling grating, and at least part of the anti-reflection layer is located in the non-grating area.
  • This solution limits the anti-reflection layer to be located in the non-grating area on the optical waveguide, which is used to improve the transmittance and light uniformity of ambient light in the non-grating area, and can solve the haze problem in the non-grating area.
  • the optical waveguide further includes a coupling grating, a relay grating, and a coupling grating, and the coupling grating, the relay grating, and the coupling grating are formed on the waveguide substrate.
  • the surface of the waveguide substrate is provided with a non-grating area, the non-grating area is the area outside the coupling grating, the relay grating and the coupling out grating, and at least part of the anti-reflection layer is located The non-grating area.
  • This solution limits the anti-reflection layer to be located in the non-grating area on the optical waveguide, which is used to improve the transmittance and light uniformity of ambient light in the non-grating area, and can solve the haze problem in the non-grating area.
  • part of the anti-reflection layer is located at the position of the coupling-out grating and forms a common structure with the coupling-out grating, and the common structure includes a vector along the direction of the coupling-out grating.
  • the common structure also includes the high refractive index phase regions and the low refractive index phase regions alternately distributed along the normal direction of the optical waveguide.
  • the surface connecting the coupling grating and the waveguide substrate is the coupling bottom surface of the coupling grating, and the surface of the coupling grating away from the waveguide substrate is the coupling surface.
  • the coupling-out top surface of the grating, and the coupling-out grating form part of the common structure, and the anti-reflection layer is formed between the coupling-out bottom surface and the coupling-out top surface.
  • the transparent layer structure can ensure or try not to affect the diffraction efficiency of the coupling grating. If material is added outside the coupling top surface to make an anti-reflection layer, the added material will affect the diffraction efficiency of the coupling grating.
  • the material of the coupling grating is a volume holographic material, and the common volume structure is produced through holographic multiplexing technology.
  • the optical waveguide provided by this solution has the advantages of simple manufacturing process and easy implementation.
  • the optical waveguide includes a grating structure
  • the grating structure is a volume holographic material
  • the grating structure is formed on the surface of the waveguide substrate
  • the anti-reflection layer is formed through a double-beam exposure process.
  • the grating structure the angle bisector of the angle between the two beams in the double-beam exposure process to form the anti-reflection layer is parallel to the surface of the waveguide substrate.
  • the vector direction of the anti-reflection layer obtained in this way is the direction perpendicular to the surface of the waveguide substrate, that is, the anti-reflection layer is a stacked distribution structure laminated on the surface of the waveguide substrate. Since the vector direction of the anti-reflection layer is different from the vector direction of the grating structure, This plan provides In the optical waveguide, the introduction of the anti-reflection layer will not affect the diffraction of the grating structure.
  • this application provides a near-eye display device, including an optical machine and an optical waveguide provided by any possible implementation of the fifteenth aspect, where the optical machine is located on the light incident side of the optical waveguide.
  • the near-eye display device provided in the sixteenth aspect of the application may include any one of the following solutions or a combination of solutions: the light combining unit provided by any possible implementation of the first aspect of the application, any possible implementation of the second aspect of the application.
  • the optical waveguide provided by any possible implementation manner and on the thirteenth aspect, the optical waveguide provided by any possible implementation manner.
  • the near-eye display devices provided in the third, fifth, seventh, ninth, tenth, twelfth and fourteenth aspects of this application may include any possible implementation of the fifteenth aspect.
  • Optical waveguide provided by the way.
  • this application provides a method for manufacturing an optical waveguide, which is used to manufacture the optical waveguide provided by any possible implementation of the fifteenth aspect.
  • the manufacturing method of the optical waveguide includes:
  • the substrate being a waveguide base of the optical waveguide
  • a material layer is provided on the surface of the substrate, and the material layer includes a volume holographic material
  • Curing and shaping such that the material layer is modulated into an anti-reflective layer on the waveguide substrate.
  • the material layer includes a high molecular polymer, a monomer, a photoinitiation system, and a solvent.
  • the high molecular polymer is a polymer containing C, H, O, and N with a molecular weight greater than 1000.
  • the monomers include at least one of acrylic esters, acrylamide, sulfhydryl-containing compounds, allyl compounds, and vinyl compounds.
  • the photoinitiation system is used to absorb laser energy and form active substances so that The active material reacts with the monomer to convert the monomer into a sub-high molecular polymer.
  • the light source of the double-beam exposure process includes two beam-expanded coherent laser beams.
  • the two beam-expanded coherent laser beams interfere with each other to form a sinusoidal light intensity distribution, so that the material layer A high light intensity area and a low light intensity area are formed on the high light intensity area, and the energy absorbed by the photoinitiation system in the high light intensity area is more than the energy absorbed by the photoinitiation system in the low light intensity area, so that the active material in the high light intensity area There are more active substances than in the low light intensity area, so that the high molecular polymer and the sub-high molecular polymer are separated to form an interphase distribution between the high refractive index phase region and the low refractive index phase region.
  • architecture
  • the high molecular polymer includes polyether, polyvinyl acetate, polyvinyl acetate-propylene copolymer, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, At least one of polystyrene, polycarbonate, polyurethane, polyester polyol, cellulose acetate, and polyvinyl alcohol.
  • the material layer is provided on the surface of the substrate through a coating process.
  • the step of pre-processing the substrate with the material layer includes: high-temperature treatment at 25 to 100°C, low-pressure treatment, light-protection treatment, or room temperature treatment.
  • the steps of curing and molding include high-temperature curing and molding, the temperature of the high-temperature curing and molding is 40 to 150°C, and the light intensity of the illumination curing and molding is 0.1 to 5000 mWcm-2.
  • the wavelength range of the light curing molding is 254nm ⁇ 1000nm
  • the type of light used for the light curing molding includes any one of UVA, UVB, UVC, visible light, and infrared light bands.
  • the angle between the two beams is a first angle.
  • the manufacturing method of the optical waveguide further includes manufacturing a grating structure through a double-beam exposure process, and exposing through a double-beam with an included angle of a second angle to form the grating structure, the grating structure and at least part of The antireflection layer may be located at the same location on the substrate, and the first angle and the second angle are different.
  • the present application provides an optical waveguide for use in near-eye display devices.
  • the optical waveguide includes a first waveguide substrate, a first grating structure and a first filling layer.
  • the first grating structure is formed on the optical waveguide.
  • the surface of the first waveguide substrate, the first filling layer and the first waveguide substrate are stacked, and the first filling layer and the first waveguide substrate together form a closed surrounding structure, the first grating structure Located within the surrounding structure to isolate the first grating structure from outside air, the difference between the refractive index of the first filling layer and the refractive index of air is less than or equal to 0.2.
  • One embodiment of the present application provides a filling layer around the grating structure on the waveguide substrate, and uses the filling layer to protect the grating structure and the waveguide substrate, thereby protecting the optical waveguide and improving the life and optical performance of the optical waveguide.
  • this program By providing the first filling layer, the first waveguide substrate and the first grating structure are protected, so that the first waveguide substrate and the first grating structure are isolated from the outside air, and it is ensured that the first waveguide substrate and the first grating structure avoid long-term contact.
  • the water and oxygen environment solves the problems of easy aging, corrosion and atomization of optical waveguides, and can also resist external impact forces to avoid damage to the optical waveguide.
  • the implementation provided in this application can ensure the service life and optical performance of the optical waveguide.
  • the first filling layer includes a grating contact surface, and the grating contact surface has the same periodically arranged microstructure as the first grating structure, so that the first filling layer
  • the grating contact surface is bonded to the surface of the microstructure of the first grating structure.
  • the first filling layer includes a grating contact surface, the grating contact surface is planar, and there are periodically arranged slits between the first filling layer and the first grating structure. .
  • This solution allows a slit to exist between the grating contact surface and the surface of the first grating structure.
  • the manufacturing process of the first filling layer provided by this solution has lower precision requirements and is easy to manufacture.
  • the light transmittance of the first filling layer is greater than or equal to 80%. This solution limits the light transmittance of the first filling layer, which can ensure the light transmittance of the optical waveguide.
  • the thickness of the first filling layer is less than or equal to 1000um. This solution ensures the refractive index and light transmittance of the optical waveguide by limiting the thickness of the first filling layer, and gives the optical waveguide the advantage of being lightweight.
  • the material of the first filling layer includes any one or a combination of aerogel materials, resin materials, inorganic materials, and organic materials.
  • the material of the first filling layer is silica aerogel.
  • pores are introduced into the silica material to form a silica aerogel.
  • Silica aerogel can be used as the material of the first filling layer.
  • Silica aerogel is a solid material with a three-dimensional porous network structure composed of nano-silica particles connected to each other. These pores are filled with air. By adjusting the pores of the silica aerogel, By adjusting the refractive index, more than 90% of the volume of aerogels can currently be made up of air.
  • Pure silica aerogels are transparent and colorless, and the lowest refractive index can reach 1.007, which is close to the refractive index of air. And because most of the volume is air, the density is also very low. It also has good light transmittance and hardness. It can currently reach 95% light transmittance and can withstand pressure thousands of times its own weight.
  • the optical waveguide further includes a first cover plate, the first cover plate is fixedly connected to the first waveguide base, and the first filling layer is stacked on the first cover plate.
  • the first filling layer and the first cover plate are bonded between the first waveguide substrate and the first waveguide substrate.
  • the first cover plate and the first waveguide base are fixedly connected through a glue dispensing structure, and the glue dispensing structure is distributed around the first filling layer.
  • This solution provides a fixing solution between the first cover plate and the first waveguide base.
  • the glue-dispensing fixation structure is easy to operate.
  • the glue will not damage the first waveguide base.
  • the optical properties of the first waveguide substrate have destructive effects.
  • the optical waveguide further includes a second grating structure, a second filling layer and a second cover plate, and the second grating structure and the first grating structure are distributed on the first waveguide substrate.
  • the second filling layer and the first waveguide base are stacked, and the second filling layer and the first light wave base jointly enclose the second grating structure, and the second filling layer
  • the difference between the refractive index of the layer and the refractive index of air is less than or equal to 0.2
  • the second cover plate and the first waveguide base are fixedly connected, and the second filling layer is stacked between the second cover plate and the first waveguide base.
  • the second filling layer and the second cover plate are bonded between the first waveguide substrate.
  • the optical waveguide further includes a second waveguide substrate and a third grating structure, the third grating structure is formed on the second waveguide substrate, and the second waveguide substrate and the third grating structure are formed on the second waveguide substrate.
  • a waveguide substrate is stacked, and a third filling layer is provided between the second waveguide substrate and the first optical waveguide substrate. The difference between the refractive index of the third filling layer and the refractive index of air is less than or equal to 0.2.
  • the optical waveguide further includes at least two second waveguide substrates, each of the second waveguide substrates is provided with a third A three-grating structure, at least two second waveguide substrates are stacked on a side of the first waveguide substrate away from the first filling layer, between the second waveguide substrate and the first waveguide substrate, and A third filling layer is disposed between adjacent second waveguide substrates.
  • the third filling layer and the second waveguide substrate together surround the third grating structure.
  • the refractive index of the third filling layer The difference between the refractive index and the refractive index of air is less than or equal to 0.2.
  • the optical waveguide further includes a second waveguide substrate, the second waveguide substrate and the first waveguide substrate are stacked and arranged, and a third grating structure is provided on the surface of the second waveguide substrate, The third grating structure and the first grating structure are arranged oppositely, the first filling layer is filled between the first waveguide substrate and the second waveguide substrate, and the first filling layer covers the second waveguide. substrate and third grating structure.
  • the top surface of the first waveguide substrate and the bottom surface of the second waveguide substrate can be used as the surface layer of the optical waveguide, without the need to provide other cover structures, which is conducive to the design of light and thin optical waveguides.
  • the optical waveguide provided by this solution has the advantage of being lightweight.
  • the present application provides an optical waveguide, including a first waveguide substrate, a first grating structure, a waveguide filling structure, a third grating structure and a first filling layer, the first grating structure being formed on the first
  • the surface of the waveguide substrate, the waveguide filling structure wraps the first grating structure and covers the first waveguide substrate
  • the third grating structure is formed on the surface of the waveguide filling structure facing away from the first waveguide substrate, so
  • the first filling layer covers the waveguide filling structure, the first filling layer and the waveguide filling structure together form a closed surrounding structure
  • the third grating structure is located within the surrounding structure, so that the third grating structure
  • the grating structure is isolated from the outside air, and the difference between the refractive index of the first filling layer and the refractive index of air is less than or equal to 0.2.
  • a multi-layer (two or more layers) grating structure can also be constructed by means of a waveguide filling structure.
  • This solution provides a multi-layer architecture based on a single-layer waveguide substrate combined with a waveguide filling structure.
  • the waveguide filling structure and the first filling layer are used to protect the grating structures of each layer.
  • the outermost first filling layer Combined with the cover, it also has the function of supporting and protecting the cover.
  • the difference between the refractive index of the waveguide filling structure and the refractive index of the first waveguide substrate is between 0-0.5.
  • This solution limits the range of the refractive index difference between the waveguide filling structure and the first waveguide substrate. Through the restriction of this range, each layer of the grating structure can perform diffraction efficiency, so that both the waveguide filling structure and the first waveguide substrate have full The function of reflecting and spreading light.
  • the optical waveguide further includes a first cover plate, and the first cover plate is located on a side of the first filling layer facing away from the waveguide filling structure.
  • a first cover plate is provided as a protective layer of the optical waveguide. The first filling layer can support and protect the first cover plate to prevent the first cover plate from being damaged under the action of external stress.
  • the edge of the waveguide filling structure is retracted compared to the first waveguide base, so as to reserve a position at the edge of the first waveguide base for setting a dispensing structure, and the dispensing structure is fixedly connected to the the first cover plate and the first waveguide substrate.
  • This solution limits the fixed connection method between the first cover plate and the first waveguide base. Through glue dispensing connection, the structural stability of the optical waveguide can be ensured.
  • this application provides a near-eye display device, including an optical machine and an optical waveguide described in any possible implementation of the eighteenth aspect or an optical waveguide described in any possible implementation of the nineteenth aspect.
  • Waveguide, the optical waveguide is located on the light exit side of the optical machine.
  • the near-eye display device provided in the twentieth aspect of this application may include any one of the following solutions or a combination of solutions: the light combining unit provided by any possible implementation of the first aspect of this application, any possible implementation of the second aspect of this application
  • the near-eye display devices provided in the third, fifth, seventh, ninth, tenth, twelfth, fourteenth and sixteenth aspects of this application may include any of the eighteenth aspects.
  • this application provides a method for manufacturing an optical waveguide, including:
  • the difference between the refractive index of the first filling layer and the refractive index of air is less than or equal to 0.2.
  • this application provides a method for manufacturing an optical waveguide, including:
  • the hard master mold has a grating mold structure, and the grating mold structure has the same shape as the first grating structure;
  • this application provides a method for manufacturing an optical waveguide, including:
  • the optical waveguide intermediate structure includes a first waveguide substrate, a first grating structure and a first cover plate.
  • the first grating structure is formed on the surface of the first waveguide substrate, and the third grating structure is formed on the surface of the first waveguide substrate.
  • a cover plate and the first waveguide base are stacked and fixedly connected, and a gap is formed between the first cover plate and the first waveguide base and between the first cover plate and the first grating structure;
  • An injection hole is provided on the first cover plate
  • Filling material is injected through the injection hole to form a first filling, the first filling layer and the first waveguide substrate together form a closed surrounding structure, and the first grating structure is located within the surrounding structure, so that The first grating structure is isolated from the outside air, and the difference between the refractive index of the first filling layer and the refractive index of air is less than or equal to 0.2.
  • this application provides a method for manufacturing an optical waveguide, including:
  • the first grating structure is located within the surrounding structure to isolate the first grating structure from the outside air, and the difference between the refractive index of the first filling layer and the refractive index of air is less than or equal to 0.2;
  • a dispensing structure is provided at the edge of the first filling layer and on the surface of the first waveguide substrate;
  • the first cover plate is fixed to the dispensing structure, so that the first cover plate and the first waveguide structure are fixedly connected.
  • the present application provides an optical waveguide, including a waveguide substrate and a grating structure.
  • the grating structure is combined with the waveguide substrate.
  • the waveguide substrate includes a first base material layer and a second base material layer.
  • the refractive index of the first base material layer is lower than the refractive index of the second base material layer, and the difference between the refractive index of the second base material layer and the refractive index of the first base material layer is greater than or equal to 0.1
  • the thickness of the second base material layer is between 50 microns and 300 microns; the grating structure is located on a side of the second base material layer away from the first base material layer, and/or the grating A structure is located between the first substrate layer and the second substrate layer.
  • the material of the first base material layer is glass, and the refractive index of the first base material layer is less than or equal to 1.55.
  • this solution makes the first base material layer a low refractive index material, which has the characteristics of low density, light weight and small thickness.
  • the implementation provided in this application can not only reduce the weight and thickness of the waveguide substrate, but also reduce the weight and thickness of the optical waveguide. Therefore, the light weight of the optical waveguide can be achieved on the basis of satisfying the requirement that light can propagate through total reflection (optical performance).
  • the refractive index of the second base material layer is greater than or equal to 1.65. This solution constrains the refractive index range of the second base material layer, so that the second base material layer can meet the function of total reflection propagation of light.
  • the material of the second base material layer is one or a combination of at least two of TiO2, silicon nitride, gallium nitride, and high-folding resin materials.
  • the first base material layer is used to carry the material forming the second base material layer during the process of making the second base material layer, and the second base material layer passes through a manufacturing process. It is combined with the first base material layer to form an integrated structure.
  • the surface of the first base material layer forms a trench-like microstructure through an etching process
  • the second base material layer is formed on the surface of the first base material layer and is connected to the surface of the first base material layer.
  • the groove-shaped microstructures are combined to form at least part of the grating structure.
  • This solution limits the grating structure that can be formed between the first base material layer and the second base material layer.
  • the etching process forms a trench-like microstructure, which is conducive to realizing the overall optical waveguide. To reduce the weight, setting the grating structure at this position can also improve the diffraction efficiency of the optical waveguide.
  • At least part of the grating layer is provided on the surface of the first base material layer, at least part of the grating structure is located on the grating layer, and the second base material layer is directly formed on the grating layer through a manufacturing process.
  • the grating layer faces away from the surface of the first substrate layer.
  • the thickness of the waveguide substrate is less than 0.35 mm.
  • the first base material layer is not only used to carry the second base material layer in the process of making the optical waveguide, but also to protect the second base material layer and the grating structure from erosion by external dust, air or moisture. , ensuring the diffraction efficiency of the optical waveguide.
  • At least part of the grating structure is formed on a surface of the second base material layer facing away from the first base material layer.
  • This solution provides a solution with a grating structure on the surface of the second base material layer facing away from the first base material layer. The design of this solution provides more flexibility in the design of the optical waveguide.
  • a protective layer is provided on a side of the second base material layer facing away from the first base material layer.
  • the protective layer is used to protect the second substrate layer and the grating structure.
  • the optical waveguide includes a functional area and an edge area, the edge area surrounds the functional area, the waveguide substrate and the grating structure are located in the functional area, and the edge area is provided with a waveguide.
  • An edge body, the waveguide edge body is combined with the edge of the waveguide base, the waveguide edge body is light-transmissive, and the density of the waveguide edge body is smaller than the density of the first waveguide base material.
  • the density of the edge region is smaller than the density of the first base material layer, so the edge region located outside the waveguide base is beneficial to achieving lightweighting of the optical waveguide.
  • the waveguide edge body is made of resin material. This solution achieves lightweight optical waveguides by limiting the material of the edge body of the waveguide.
  • the refractive index of the waveguide edge body is: 1.55-1.75. This solution achieves lightweight optical waveguides by limiting the refractive index range of the edge body of the waveguide.
  • the optical waveguide further includes a wrapping layer, the wrapping layer fully wraps or half wraps the waveguide substrate and the grating structure, the outer surface of the wrapping layer includes a first surface, and the The first surface is a curved surface to correct different degrees of myopia.
  • At least one surface of the wrapping layer has different curvatures. This solution limits the wrapping layer to have surfaces with different curvatures, so that the wrapping layer can not only compensate for the viewing angle deviation caused by the difference in refractive index between the waveguide base and the wrapping layer, but can also be used to correct different degrees of myopia.
  • this application provides a near-eye display device, including an optical machine and an optical waveguide provided by any possible implementation of the twenty-fifth aspect, where the optical waveguide is located on the light exit side of the optical machine.
  • the near-eye display device provided by the twenty-sixth aspect of the application may include any one of the following solutions or a combination of solutions: the light combining unit provided by any possible implementation of the first aspect of the application, any of the second aspects of the application.
  • the optical machine provided by the possible implementation manner, the optical component provided by the fourth aspect of the present application, the optical waveguide provided by any possible implementation manner of the sixth aspect, the optical waveguide provided by any possible implementation manner of the eighth aspect, the optical waveguide provided by any possible implementation manner of the eighth aspect, The optical waveguide provided by any possible implementation method of the eleventh aspect, the optical waveguide provided by any possible implementation method of the thirteenth aspect, the optical waveguide provided by any possible implementation method of the fifteenth aspect, the eighteenth aspect The optical waveguide described in any possible implementation manner of the aspect, and the optical waveguide described in any possible implementation manner of the nineteenth aspect.
  • the near-eye display devices provided in the third, fifth, seventh, ninth, tenth, twelfth, fourteenth, sixteenth and twentieth aspects of this application may all include The optical waveguide described in any possible implementation manner of the twenty-fifth aspect.
  • embodiments of the present application provide a method for manufacturing an optical waveguide, including: manufacturing a first grating layer on a base layer, the first grating layer having a first grating structure, such that the first grating layer It is stacked with the base layer; a second grating layer is made through a grating structure template, and the second grating layer is made on the side of the first grating layer away from the base layer, and the second grating layer has a Two grating structures, with an adhesion-promoting layer between the first grating layer and the second grating layer; demolding the grating structure template so that the base layer, the first grating layer and the second grating layer The two grating layers are combined into one body to form an optical waveguide.
  • a first imprinting material layer is spin-coated on the base layer to provide a first grating structure template, the first grating structure template is pressed onto the first imprinting material layer through a nanoimprinting process, and then the first imprinting is cured.
  • the material layer is demoulded to obtain the first grating layer; then the second grating layer is made through the second grating structure template, and the first grating layer and the second grating layer are bonded using an adhesion-promoting layer.
  • an adhesion-promoting layer is provided between the first grating layer and the second grating layer to separate the first grating layer and the second grating layer. Therefore, when the second grating layer is made, the first grating layer will not be damaged due to pressure or impact force. The impact of the grating layer reduces the probability of deformation and damage of the first grating layer. and Moreover, by taking advantage of the adhesiveness of the adhesion-promoting layer, the second grating layer and the adhesion-promoting layer can maintain the firmness between them after they are connected, thereby improving the reliability of demolding.
  • the second grating layer can be bonded to the first grating layer through the adhesion-promoting layer, thereby improving the connection strength between the first grating layer and the second grating layer and preventing the first grating layer and the second grating layer from loosening. , which is beneficial to the subsequent processing of optical waveguides.
  • the step of making the second grating layer through the grating structure template includes: making a dielectric layer on the first grating layer; and coating the adhesion promoter layer on the dielectric layer. ; Coating a second embossing material layer on the adhesion-promoting layer; applying the second grating structure to the second embossing material layer through the grating structure template to form the second grating layer.
  • the grating structure template in the above steps should be a second grating structure template, used to make the second grating layer.
  • the dielectric layer can form mechanical protection for the first grating layer, ensuring that the first grating layer is not easily deformed during the process of imprinting the second grating layer.
  • the refractive index of light in the first grating layer can also be increased, thereby achieving excellent optical properties of the optical waveguide.
  • the production method before the step of producing the second grating layer through the grating structure template, includes: performing anti-adhesive treatment on the working surface of the grating structure template, through the grating structure During the process of using the template to form the second grating layer on the second embossing material layer, the working surface is in contact with the second embossing material layer.
  • the purpose of anti-adhesive treatment on the working surface is to enable smoother demoulding after the second imprinting material layer is solidified into the second grating layer, to avoid adhesion between the second grating layer and the second grating structure template, and to prevent damage to the second grating. layer integrity.
  • the step of forming a dielectric layer on the first grating layer includes: forming the dielectric layer on the first grating layer through a coating process.
  • the advantage of manufacturing the dielectric layer through the coating process is that the process technology is simple and easy to achieve mass production.
  • the material of the dielectric layer includes oxide or nitride; in a possible implementation, the refractive index of the dielectric layer is between 1.8 and 2.3.
  • the refractive index of the dielectric layer is high, which can effectively improve the optical efficiency and improve the viewing angle of the electronic device with the optical waveguide structure. In other embodiments, the refractive index of the dielectric layer can be greater than 2.3.
  • the step of forming a dielectric layer on the first grating layer further includes: performing surface treatment on the dielectric layer through a chemical mechanical polishing process.
  • the side of the dielectric layer produced through the steps in the above embodiments facing away from the first grating layer can be formed with a surface parallel (or approximately parallel) to the base layer. The purpose of processing this surface is to improve The roughness of the surface improves the adsorption force on the surface of the medium layer and prevents the adhesion-promoting layer from falling off.
  • the refractive index of the second imprinting material layer is between 1.6 and 1.9. In a possible implementation, the thickness of the second imprinting material layer is between 100 and 400 nm.
  • the second imprinting material layer has a high refractive index, which can effectively improve the light efficiency and improve the viewing angle of the electronic device with the optical waveguide structure. In other embodiments, the refractive index of the second imprinting material layer may be greater than 1.9.
  • controlling the thickness of the second imprinting material layer between 100 and 400 nm can ensure that the thickness of the second grating layer does not exceed the maximum value of this range, thereby effectively controlling the overall thickness of the optical waveguide structure and realizing the optical waveguide structure. Lightening and thinning of electronic devices with waveguide structures.
  • the thickness of the adhesion-promoting layer is between 0 and 20 nm. It can be understood that controlling the thickness of the adhesion-promoting layer within this range can ensure the connection strength between the first grating layer and the base layer without affecting the overall thickness of the optical waveguide structure. When the thickness of the adhesion-promoting layer exceeds this range, it is easy to cause the overall thickness of the optical waveguide structure to be too thick and affect the refraction of light.
  • the step of producing the second grating layer through the grating structure template includes: providing the grating structure template; producing a second grating layer on the grating structure template; A layer bonds the second grating layer connecting the grating structure template to the first grating layer.
  • the grating structure template in the above steps should be a second grating structure template, used to make the second grating layer.
  • the fabrication steps of the first grating layer and the second grating layer can be performed simultaneously, without the need to fabricate each hierarchical structure in sequence; after fabricating the first grating layer and the second grating layer separately, The layers are then bonded through an adhesion-promoting layer, which can improve manufacturing efficiency and facilitate large-scale production.
  • the step of producing the second grating layer through the grating structure template includes: first coating the adhesion-promoting layer on the surface of the second grating layer facing away from the grating structure template, and then The first grating layer is pasted on the adhesion-promoting layer.
  • the second grating layer should be made by coating a second layer of imprinting material on the second grating structure template. Before the second imprinting material layer is cured, an adhesion-promoting layer can be provided on the side of the second imprinting material layer facing away from the second grating structure template, and then the second imprinting material layer together with the second grating structure template are placed on the On the first grating layer, the second imprinting material layer is solidified.
  • the adhesion-promoting layer provided in this way can be completely covered on the first grating layer through the deformability of the second imprinting material layer, thereby improving the uniformity of the adhesion-promoting layer.
  • the manufacturing method further includes: manufacturing a dielectric layer on the first grating layer, and bonding the second grating layer connected to the grating structure template through the adhesion-promoting layer. on the dielectric layer.
  • the dielectric layer can form mechanical protection for the first grating layer, further ensuring that the first grating layer is not easily deformed during the process of imprinting the second grating layer.
  • the refractive index of light in the first grating layer can also be increased, thereby achieving excellent optical performance of the optical waveguide structure.
  • the surface morphology of the dielectric layer is the same as the surface morphology of the first grating layer.
  • the dielectric layer can be formed on the surface of the first grating layer through a coating process, and the two opposite sides of the dielectric layer have the same surface morphology as the first grating layer. It can be understood that the dielectric layer can form a thinner film layer on the surface of the first grating layer to ensure the reflective effect on the first grating layer.
  • the dielectric layer in this embodiment is thinner, which can achieve a thinning effect on the optical waveguide structure, thereby manufacturing thinner and lighter electronic devices.
  • the refractive index of the dielectric layer is between 1.8 and 2.3, and the thickness of the dielectric layer is between 0 and 50 nm.
  • the specific material of the dielectric layer may be an oxide, such as titanium dioxide.
  • the adhesion-promoting layer and the The first grating layer is in direct contact.
  • the working surface of the grating structure template is subjected to anti-adhesive treatment, and the second grating layer is made on the grating structure template.
  • the second grating layer is produced on the working surface.
  • the purpose of anti-adhesive treatment on the working surface is to enable smoother demoulding after the second imprinting material layer is solidified into the second grating layer, to avoid adhesion between the second grating layer and the second grating structure template, and to prevent damage to the second grating. layer integrity.
  • the step of producing the first grating layer on the base layer includes: coating a first imprint material layer on the base layer, and applying a nanoimprint process to the first grating layer.
  • the first grating layer is formed on the imprinting material layer.
  • the force endured by the first imprinting material is the first pressure
  • the grating structure is connected through the adhesion-promoting layer.
  • both the first grating layer and the second grating layer produced by the nanoimprinting process can have micro-nano structures.
  • the first grating layer When the first grating layer is produced, there is a base layer underneath and does not have micro-nano structures. Therefore, in order to ensure that the second grating layer A larger first pressure can be used for forming a grating layer.
  • the first grating layer When making the second grating layer on the first grating layer, the first grating layer has micro-nano structures.
  • the second pressure should be smaller than the first grating layer. A pressure to achieve the purpose of protecting the first grating layer.
  • the material of the first grating layer and the second grating layer are different. It can be understood that the material of the first grating layer and the material of the second grating layer may be the same or different.
  • the first grating layer and the second grating layer contact different substrates when they are made, so different materials can be selected to make the first grating layer and the second grating layer respectively according to the material properties.
  • the first grating structure on the first grating layer and the second grating structure on the second grating layer have different structures.
  • the The first grating structure and the second grating structure have different sizes or periods.
  • the first grating structure is a coupling structure
  • the second grating structure is a coupling structure.
  • the first grating structure and the second grating structure are micro-nano structures on the optical waveguide structure, used for light reflection or light transmission, so the first grating structure and the second grating structure can be designed in different shapes according to the light that needs to be acted on. , size or period.
  • embodiments of the present application further provide an optical waveguide, including a base layer, a first grating layer, a second grating layer and an adhesion-promoting layer; the first grating layer and the base layer are stacked, and the third grating layer
  • a grating layer has a first grating structure; a second grating layer is stacked on a side of the first grating layer away from the base layer, the second grating layer has a second grating structure, and the adhesion-promoting layer is on the side of the first grating layer facing away from the base layer. between a grating layer and the second grating layer.
  • an adhesion-promoting layer is provided between the first grating layer and the second grating layer to separate the first grating layer and the second grating layer. Therefore, when the second grating layer is made, the first grating layer will not be damaged due to pressure or impact force. The impact of the grating layer reduces the probability of deformation and damage of the first grating layer. Furthermore, by taking advantage of the adhesiveness of the adhesion-promoting layer, the second grating layer and the adhesion-promoting layer can maintain the firmness between them after they are connected, thereby improving the reliability of demolding.
  • the second grating layer can be bonded to the first grating layer through the adhesion-promoting layer, thereby improving the connection strength between the first grating layer and the second grating layer and preventing the first grating layer and the second grating layer from loosening. , which is beneficial to the subsequent processing of optical waveguide structures.
  • the material of the dielectric layer includes oxide or nitride; in a possible implementation, the refractive index of the dielectric layer is between 1.8 and 2.3.
  • the surface morphology of the dielectric layer is the same as the surface morphology of the first grating layer.
  • the thickness of the adhesion-promoting layer is between 0 and 20 nm.
  • the refractive index of the first grating layer is between 1.6 and 1.9. In a possible implementation, the refractive index of the first grating layer is between 1.6 and 1.9.
  • the thickness of a grating layer is between 100 and 400nm.
  • the first grating layer includes a first grating structure
  • the second grating layer includes a second grating structure
  • the first grating structure and the second grating structure have different structures
  • the first grating structure and the second grating structure have different sizes or periods.
  • the present application provides a near-eye display device, including an optical machine and any possible implementation method in the twenty-eighth aspect, providing the optical waveguide, which is located at the light output of the optical machine. side.
  • the near-eye display device provided by the twenty-ninth aspect of the application may include any one of the following solutions or a combination of solutions: the light combining unit provided by any possible implementation of the first aspect of the application, any of the second aspects of the application.
  • the optical machine provided by the possible implementation manner, the optical component provided by the fourth aspect of the present application, the optical waveguide provided by any possible implementation manner of the sixth aspect, the optical waveguide provided by any possible implementation manner of the eighth aspect, the optical waveguide provided by any possible implementation manner of the eighth aspect,
  • the optical waveguide provided by any possible implementation method of the eleventh aspect, the optical waveguide provided by any possible implementation method of the thirteenth aspect, the optical waveguide provided by any possible implementation method of the fifteenth aspect, the eighteenth aspect The optical waveguide described in any possible implementation manner of the aspect, the optical waveguide described in any possible implementation manner of the nineteenth aspect, and the optical waveguide described in any possible implementation manner of the twenty-fifth aspect.
  • the display device may include the optical waveguide described in any possible implementation manner of the twenty-eighth aspect.
  • the present application provides an optical waveguide.
  • the optical waveguide includes an optical waveguide body, a first anti-reflection layer, a filling body layer, a second anti-reflection layer and a surface protection layer that are stacked in sequence.
  • the first anti-reflection layer Located between the optical waveguide body and the filling body layer, the difference between the refractive index of the filling body layer and the refractive index of air is within a first preset range, and the second anti-reflection layer is located at the Between the filling body layer and the surface protection layer, the refractive index of the second anti-reflection layer changes in a gradual trend, and the refractive index of the part adjacent to the second anti-reflection layer and the filling body layer is different from the refractive index of the second anti-reflection layer.
  • the refractive index difference between the filling body layers is within a second preset range
  • the refractive index of the portion adjacent to the second anti-reflection layer and the surface protective layer and the refractive index difference between the surface protective layer are within a second preset range. 2 within the preset range.
  • this application can support and protect the optical waveguide body and the surface protective layer, and avoid the optical performance of the optical waveguide body being affected by environmental factors.
  • the refractive index of the filling body layer is small, such as close to air, there is a refractive index difference between the refractive index of the filling body layer and the refractive index of the surface protective layer, and between the refractive index of the filling body layer and the refractive index of the optical waveguide body. There is also a refractive index difference. If the first anti-reflection layer and the second anti-reflection layer are not provided, there will be a difference in the connection position between the filling body layer and the optical waveguide body and between the filling body layer and the surface protection layer. Light reflection affects the transmittance of the optical waveguide. Therefore, this application achieves the overall anti-reflection effect of the optical waveguide by providing a first anti-reflection layer and a second anti-reflection layer.
  • the first anti-reflection layer can be formed on the surface of the optical waveguide main body in the form of a coating to achieve total reflection of the optical waveguide main body through the principle of optical interference.
  • the first anti-reflection layer can improve the scattering absorption problem at the optical waveguide interface. Increase the anti-reflection and anti-reflection effect at this interface.
  • the first anti-reflection layer can be a single-layer structure.
  • the refractive index of the first anti-reflection layer is related to the refractive index of the medium at the two interfaces above and below, and it is estimated that the two Taking the square root of the product, the thickness of the first antireflection layer is 1/4 of the incident wavelength.
  • the first anti-reflection layer can also be a multi-layer film structure. If it is a multi-layer film structure, the equivalent refractive index of the multi-layer film layers is required to be the above value to achieve a low reflectivity at the interface (theoretically reduced to 0). It plays the role of reducing reflection on the surface.
  • the second anti-reflection layer has a gradient refractive index solution, forming a gradient refractive index design between the surface protective layer and the filling body layer, solving the problem of light reflection between the surface protection layer and the filling body layer, and improving the performance of the optical waveguide Translucency.
  • the surface of the optical waveguide body can form a relief grating for transmitting light, so providing a filling body layer between the optical waveguide body and the surface protection layer can also protect the relief grating from being scratched. scratches.
  • the difference between the refractive index of the filling body layer and the refractive index of air is between 0.1 and 0.25, and/or the thickness of the filling body layer is between 30 and 50 ⁇ m.
  • the filling body layer includes a base and a refractive medium, and the refractive medium is dispersed in the base.
  • a refractive medium can be added to the material for making the filling body layer, and then the filling body layer is made by the manufacturing method in the above embodiment.
  • the specific material of the base may be the silicone polymer mentioned above.
  • the specific form of the refractive medium is not limited and can be granular microspheres or hollow areas formed in the filled body layer.
  • the refractive medium may be a particulate material, and the refractive index of the refractive medium may be different from the refractive index of the substrate.
  • the light-shielding medium dispersed in the substrate can be used to adjust the refractive index of the filling body layer, so that the refractive index of the filling body layer can be within the range of the above embodiments.
  • the refractive medium is resin particles
  • the refractive index of the resin particles is 1, and/or the particle size of the resin particles is between 0.1 and 100 ⁇ m.
  • the reason for using resin particles as the refractive medium is that the resin particles have good light transmittance and high transmittance to visible light. Therefore, adding resin particles to the base will not affect the light transmittance of the filled main layer.
  • the use of resin particles as the refractive medium is also beneficial to the stability of the filled main layer structure. Because the chemical properties of the resin particles and the siloxane polymer are similar, the base and the refractive medium are not easily separated after the filled main layer is formed.
  • the adhesion between the substrate and the refractive medium is better and easy to encapsulate; then by adjusting the content and distribution of the resin particles with a refractive index of 1 in the substrate, the purpose of controlling the refractive index of the filling body layer is achieved; and, Controlling the particle size of the resin particles within the above range is beneficial to the molding of the filled main layer, and the manufacturing difficulty of the resin particles is low and easy for industrial production.
  • the particle size of the resin particles is smaller than the above range, the size of the resin particles is too small, making manufacturing more difficult; when the particle size of the resin particles is larger than the above range, the size of the resin particles is too large, which is not conducive to the molding of the filled main layer.
  • the resin particles have an internal hollow structure.
  • the resin particles may have a core-shell structure, the outer shell may be made of resin material, and the inner core may be air.
  • the purpose of this design is to make the refractive index of the resin particles closer to that of air.
  • the refractive index of the substrate is 1.4.
  • the material of the base may be the same siloxane polymer as the material of the first anti-reflection layer.
  • the reason for using the same silicone polymer as the first anti-reflection layer is that the filling body layer using the same material as the base is easier to bond with the first anti-reflection layer and can avoid layer separation due to different materials. Phenomenon. In addition, it can also reduce the steps of replacing materials, and the same kind of materials is easy to obtain, which is conducive to industrial production and cost reduction.
  • the filling body layer is aerogel.
  • airgel By using airgel as the filling main layer, it can not only save the steps of mixing the substrate and the refractive medium, reduce the preparation process, but also reduce the manufacturing cost of the filling main layer.
  • the refractive index of the second anti-reflection layer is between 1.1 and 1.4, and/or the thickness of the second anti-reflection layer is between 1 and 2 ⁇ m.
  • the refractive index of the second anti-reflective layer is prevented from being too high, which is conducive to controlling the refractive index of the entire optical waveguide within an appropriate range to avoid damage to the user's vision; and the thickness It can effectively support the wafer (optical waveguide main body) and avoid the optical waveguide from being too thick or too thin.
  • the second anti-reflection layer includes a plurality of second anti-reflection sub-layers arranged in a stack, and the difference between the refractive index of any two adjacent layers of the second anti-reflection sub-layer is within a predetermined value. within the setting range.
  • the refractive index of the plurality of second antireflective sub-layers increases along a gradient.
  • the second anti-reflection layer and the filling body layer are made of the same material but have different densities; or the second anti-reflection layer and the filling body layer are formed through the same manufacturing process.
  • the first anti-reflection layer is formed on the surface of the optical waveguide body by coating.
  • this application also provides a near-eye display device, including the optical waveguide described in any possible implementation manner of the thirtieth aspect.
  • the near-eye display device provided in the thirty-first aspect of this application may include any one of the following solutions or a combination of solutions: the light combining unit provided by any possible implementation of the first aspect of this application, any one of the second aspects of this application
  • the near-eye display device provided in the nineteenth aspect may include the optical waveguide described in any possible implementation manner of the thirtieth aspect.
  • the present application also provides a method for preparing an optical waveguide, including: forming a first anti-reflection layer on the optical waveguide main body, so that the first anti-reflection layer and the optical waveguide main body are stacked; A filling body layer is formed on the side of the first anti-reflection layer facing away from the optical waveguide body; a second anti-reflection layer is formed on the side of the filling body layer facing away from the first anti-reflection layer.
  • the refractive index of the anti-reflective layer changes in a gradient trend; a surface protective layer is formed on the side of the second anti-reflective layer away from the filling body layer.
  • the optical waveguide prepared by the above preparation method in this application can use the filling body layer filled between the optical waveguide body and the surface protective layer to support and protect the optical waveguide body and the surface protective layer; at the same time, the first anti-reflection layer is used It can improve the scattering and absorption problem of the optical waveguide body at the interface and increase the anti-reflection and anti-reflection effect at the interface.
  • the second anti-reflection layer with a gradient refractive index a gradient refractive index design is formed between the surface protective layer and the filling body layer, solving the problem of light reflection between the surface protection layer and the filling body layer, and improving the optical waveguide of light transmittance.
  • the step of making a filling body layer on the side of the first anti-reflection layer away from the optical waveguide body includes: adding a refractive medium to the base material and uniformly mixing to obtain a filling body material;
  • the filling body material is coated on the first anti-reflection layer by multiple glue spreading methods, roller coating ultrasonic spraying method, air spraying method, or pulling method; the filling body material is solidified to obtain the filling body material. Fill the body layer.
  • the step of adding the refractive medium to the base material includes: adding the refractive material to the dispersion liquid and mixing it evenly; producing the refractive medium by using the spray granulation method.
  • the particle size of the refractive medium is between 0.1 and 100 ⁇ m. Compared with ordinary drying, spray drying has the function of granulation, which can reduce the size of the finished particles to a certain extent and make the shape relatively regular.
  • the step of making a filling body layer on the side of the first anti-reflection layer facing away from the optical waveguide body includes: adding a silicon source material to a solvent and coating it on the first anti-reflection layer. On the reverse layer; solidify the silicon source material through an acid-base two-step method and an alcohol supercritical drying method to obtain the filling body layer.
  • the purpose of the above steps is to use aerogel as the main filling layer and the pores in the aerogel can be adjusted to produce an aerogel that meets the refractive index requirements on the first anti-reflection layer through the supercritical drying method. Compared with the substrate and refractive medium in the above embodiments, the steps for making aerogel are simple and the material cost is low.
  • the step of forming a second anti-reflection layer on the side of the filling body layer facing away from the first anti-reflection layer includes: A plurality of second anti-reflection sub-layers are formed in a stack on one side, and the refractive index of the plurality of second anti-reflection sub-layers increases along a gradient in the direction from the optical waveguide body to the surface protection layer.
  • the plurality of second antireflective sublayers can be produced one by one in a step-by-step manner, and the properties of the raw materials for producing the second antireflective sublayer can be adjusted to obtain second antireflective sublayers with different refractive indexes.
  • the step of making a plurality of stacked second antireflection sub-layers on the side of the filling body layer away from the first antireflection layer includes: adding a refractive medium to the base material, and uniformly mixing to obtain a filling body material; mixing the filling body material and the base material according to a preset ratio to obtain multiple groups of second anti-reflection materials, and the multiple groups of second anti-reflection materials have different refractive indexes; in the Multiple sets of the second anti-reflection materials are sequentially coated and solidified on the filling body layer to obtain multiple stacked second anti-reflection sub-layers.
  • the second antireflection sublayer is produced by the method provided in the above steps.
  • the characteristic is that the filling host material provided in the above embodiment can be used, supplemented by base materials in different proportions, thereby preparing a variety of second antireflection sublayers with different refractive indexes.
  • the advantage of anti-reflection materials is that there is no need to add new ingredients and the existing materials filling the main layer can be used to continue preparation without changing the process production line. It is suitable for mass production and the cost is controllable.
  • the step of making a plurality of stacked second anti-reflection sub-layers on the side of the filling body layer away from the first anti-reflection layer includes: adding a silicon source material to a solvent to obtain Multiple sets of second anti-reflection materials, the volume ratios of the silicon source material and the solvent in the multiple sets of second anti-reflection materials are different; multiple sets of the second anti-reflection materials are sequentially coated and cured on the filling body layer.
  • Anti-reflection material is used to obtain a plurality of second anti-reflection sub-layers arranged in a stack.
  • the second antireflection sub-layer is produced by the method provided in the above steps, which is characterized in that the filling host material provided in the above embodiment can be used, supplemented by different proportions of silicon source materials, that is, the second antireflection sublayer can be made with different concentration ratios.
  • Anti-reflection materials can produce aerogels with various porosity. The advantage is that there is no need to add new ingredients and the existing materials filling the main layer can be used to continue preparation without changing the process production line. It is suitable for mass production and the cost is controllable.
  • the present application provides an optical waveguide for use in near-eye display devices, including a first waveguide substrate and a first grating structure formed on the surface of the first waveguide substrate, and the first waveguide substrate is used for Total reflection of the light path, the first waveguide base and the first grating structure are both flexible, and the optical waveguide has deformation characteristics so that the optical waveguide can adapt to lenses with different curvatures of the near-eye display device.
  • the first waveguide base and the first grating structure are both flexible. It can be understood that all structures in the optical waveguide are flexible, so that the optical waveguide can be bent arbitrarily to match lenses with different curvatures and achieve lightness and thinness of the lens. ization, bringing about lightweight near-eye display devices.
  • the refractive index of the first waveguide substrate is greater than or equal to 1.6, and the thickness of the first waveguide substrate is less than 300um.
  • the material of the first waveguide substrate is flexible glass or flexible optical resin material. This solution constrains the flexibility performance of the first waveguide substrate by limiting the material of the first waveguide substrate.
  • the first grating structure is integrally formed in the first waveguide substrate.
  • the first grating structure is formed on the surface of the first waveguide substrate through an etching process.
  • the first grating structure is directly fabricated on the first waveguide substrate, and there is no need to provide an additional material layer for making the grating.
  • the first grating structure and the first waveguide substrate are an integrated structure, and the structure is stable. Better, easy to modulate diffraction efficiency and maintain optical performance.
  • the first grating structure is formed on the surface of the first waveguide substrate through an etching process.
  • the first grating structure is formed on the first grating layer, the first grating layer and the first waveguide base are stacked, the first grating layer is flexible, and the third grating layer
  • the material of the first grating layer is imprinting glue.
  • the thickness of the first grating layer is greater than or equal to 0.2um and less than or equal to 1.2um, and the refractive index of the first grating layer is greater than or equal to 1.6.
  • This solution ensures its flexibility by constraining the thickness range and refractive index range of the first grating layer. This solution can modulate the diffraction efficiency by setting different refractive indexes.
  • the optical waveguide further includes a first modulation layer, the first modulation layer and the first waveguide base are stacked, and part of the first modulation layer is filled in the first grating.
  • the difference between the refractive index of the first modulation layer and the refractive index of the first grating structure is greater than or equal to 0.1.
  • a first modulation layer is added to the surface where the grating of the optical waveguide is located.
  • the first modulation layer covers the first grating structure, and the first modulation layer is used to protect the first grating structure.
  • the first modulation layer can also modulate the diffraction efficiency of the optical waveguide, which can make the diffraction efficiency of the optical waveguide meet the needs of the use scenario, making the optical waveguide applicable to more scenarios.
  • the refractive index of the first modulation layer is smaller than the refractive index of the first grating structure.
  • the refractive index of the first modulation layer is greater than or equal to 1.9.
  • This solution is mainly to adjust the diffraction efficiency of the first grating structure. Because the first modulation layer and the first grating structure have a refractive index difference (the refractive index difference is greater than or equal to 0.1), the diffraction efficiency will change. In order to ensure that the first modulation layer The refractive index difference between the first grating structure and the first grating structure can constrain the refractive index of the first modulation layer to a range of greater than or equal to 1.9.
  • the refractive index of the first modulation layer is greater than the refractive index of the first grating structure.
  • this solution is mainly to adjust the diffraction efficiency of the first grating structure. Because the first modulation layer and the first grating structure have a refractive index difference (the refractive index difference is greater than or equal to 0.1), the diffraction efficiency will change. In order to ensure The refractive index difference between the first modulation layer and the first grating structure can constrain the refractive index of the first modulation layer to a range of less than or equal to 1.6.
  • a first auxiliary grating structure is provided on a surface of the first modulation layer facing away from the first grating structure, and the first auxiliary grating structure is used for modulation of light.
  • the first auxiliary grating structure may be a coupling grating, a relay grating or an outcoupling grating.
  • the optical waveguide further includes a second grating structure, and the first grating structure and the second grating structure are respectively located on opposite sides of the first waveguide substrate.
  • This solution defines a double-sided optical waveguide architecture, which improves the diffraction efficiency of the optical waveguide through the combination of the first grating structure and the second grating structure.
  • the optical waveguide further includes a second modulation layer, the second modulation layer and the first waveguide base are stacked, and part of the second modulation layer is filled in the second grating.
  • the difference between the refractive index of the second modulation layer and the refractive index of the second grating structure is greater than 0.1.
  • the optical waveguide further includes a second waveguide substrate, a light confinement layer and a third grating structure
  • the second waveguide substrate is used for total reflection of the optical path
  • the second waveguide substrate is flexible
  • the light confinement layer is stacked between the first waveguide substrate and the second waveguide substrate.
  • the light confinement layer is also flexible and transparent.
  • the refractive index of the light confinement layer is lower than that of the first waveguide substrate.
  • the refractive index of the waveguide substrate is also lower than the refractive index of the second waveguide substrate.
  • the light confinement layer is used to ensure total reflection of the first waveguide substrate and the second waveguide substrate.
  • the third grating Structures are formed on the second waveguide substrate.
  • the thickness of the light limiting layer is less than or equal to 100um.
  • This solution controls the thickness of the light confinement layer to less than or equal to 100um, which is conducive to controlling the thinning of the optical waveguide, so that the optical waveguide forms a thin film structure and can have a better fit with the curved lens surface.
  • the optical waveguide further includes a flexible substrate layer, the flexible substrate layer and the first waveguide base are stacked and located on a side of the first waveguide base away from the first grating structure.
  • the flexible substrate layer is transparent and has a refractive index lower than that of the first waveguide substrate, and the flexible substrate layer is used to fit the lens of the near-eye display device.
  • a flexible substrate layer is added to the first waveguide base, and the flexible substrate layer is attached to the lens, thereby preventing the first waveguide base from being directly attached to the lens. If the first waveguide base is directly attached to the lens, the fit will The glue used may affect the optical parameters of the first waveguide substrate, and the flexible substrate layer can protect the first waveguide substrate to ensure the optical performance of the optical waveguide.
  • this application provides a method for manufacturing an optical waveguide, which is used to manufacture the optical waveguide described in any one of the possible implementation methods of the thirty-third aspect, and the manufacturing method includes:
  • the hard base including a fabrication plane
  • the sacrificial layer is dissolved to obtain the optical waveguide.
  • the step of fabricating the optical waveguide on the sacrificial layer includes:
  • a first waveguide substrate is provided on the sacrificial layer, the refractive index of the first waveguide substrate is greater than or equal to 1.6, and the thickness of the first waveguide substrate is less than 300um;
  • a first grating structure is fabricated on the first waveguide substrate.
  • the step of fabricating an optical waveguide on the sacrificial layer includes:
  • the optical waveguide intermediate structure is flexible and includes a first waveguide substrate and a first grating structure formed on a surface of the first waveguide substrate;
  • the optical waveguide intermediate structure is arranged on the sacrificial layer, and the first grating structure is in full contact with the sacrificial layer;
  • a second grating structure is formed on a side of the first waveguide substrate away from the first grating structure.
  • the step of fabricating an optical waveguide on the sacrificial layer includes:
  • a first waveguide substrate is provided on the sacrificial layer, the first waveguide substrate is used for total reflection of the optical path, and the first waveguide substrate is flexible;
  • a light confinement layer is formed on the first grating structure, the light confinement layer is also flexible and transparent, and the refractive index of the light confinement layer is lower than the refractive index of the first waveguide substrate;
  • the second waveguide substrate is used for total reflection of the light path, and the second waveguide substrate is flexible;
  • a third grating structure is fabricated on the second waveguide substrate.
  • the optical waveguide manufacturing method provided by this application utilizes a planar manufacturing process to manufacture optical waveguides on a hard substrate and a sacrificial layer, which can easily achieve mass production. Then, using the properties of the sacrificial layer, the sacrificial layer is melted to separate the hard substrate, forming a flexible optical waveguide.
  • the manufacturing method of the optical waveguide provided by this application is easy to process, has low manufacturing cost, and can protect the flexibility of the optical waveguide while being produced.
  • flexible optical waveguides with surface relief gratings can be prepared on a large scale using the nanoimprint process.
  • the present application provides a near-eye display device, including a lens and the optical waveguide provided in any possible implementation manner of the thirty-third aspect, the lens includes a curved surface portion, and the optical waveguide is attached to The surface layer or the middle layer that is bonded to the curved portion of the lens.
  • the near-eye display device provided in the thirty-fifth aspect of this application may include any one of the following solutions or a combination of solutions: the light combining unit provided by any possible implementation of the first aspect of this application, any one of the second aspects of this application
  • the near-eye display devices provided in the nineteenth aspect and the thirty-first aspect may include the optical waveguide described in any possible implementation manner of the thirty-third aspect.
  • Figure 1 is a schematic diagram of a near-eye display device provided by an embodiment of the present application.
  • FIG. 2 is a schematic diagram of a near-eye display device provided by an embodiment of the present application.
  • FIG. 3 is a schematic diagram of the embodiment shown in FIG. 1 or the embodiment shown in FIG. 2 from another direction.
  • FIG. 4 is a schematic plan view of a near-eye display device provided by an embodiment of the present application.
  • Figure 5 is a schematic diagram of an optical machine provided by an embodiment of the present application.
  • Figure 6 is a three-dimensional view of a light combining unit provided by an embodiment of the present application.
  • FIG. 7 is an exploded perspective view of the light combining unit shown in FIG. 6 .
  • FIG. 8 is an exploded view of the light combining unit shown in FIG. 6 in one state.
  • FIG. 9 is an exploded view of the light combining unit shown in FIG. 6 in one state.
  • FIG. 10A is a three-dimensional schematic diagram of an optical machine provided by an embodiment of the present application.
  • FIG. 10B is a schematic diagram of the optical path of the second wavelength range emission unit in the embodiment provided in FIG. 10A.
  • Figure 10C is a schematic diagram of an optical waveguide provided in an embodiment.
  • Figure 11 is a three-dimensional schematic diagram of an optical machine provided by an embodiment of the present application.
  • Figure 12 is a three-dimensional schematic diagram of an optical machine provided by an embodiment of the present application.
  • Figure 13 is a three-dimensional view of a light combining unit provided by an embodiment of the present application.
  • FIG. 14 is an exploded perspective view of the light combining unit shown in FIG. 13 .
  • FIG. 15 is an exploded perspective view of the light combining unit shown in FIG. 13 in one state.
  • FIG. 16 is an exploded perspective view of the light combining unit shown in FIG. 13 in one state.
  • FIG. 17 is a three-dimensional exploded schematic diagram of a state of the light combining unit shown in FIG. 13 .
  • FIG. 18 is a three-dimensional exploded schematic diagram of a state of the light combining unit shown in FIG. 13 .
  • Figure 19 is a three-dimensional schematic diagram of an optical machine provided by an embodiment of the present application.
  • FIG. 20 is a plan view of the optical machine shown in FIG. 19 in one direction.
  • FIG. 21 is an exploded schematic diagram of the light combining unit and the light emitting unit in the optical machine shown in FIG. 19 .
  • Figure 22 is a schematic diagram of an optical component provided by an embodiment of the present application.
  • FIG. 23 is a schematic diagram of the ghost image problem caused by the optical assembly shown in FIG. 22 .
  • Figures 24A and 24B are schematic diagrams of optical components provided by an embodiment of the present application.
  • Figures 24A and 24B respectively show schematic diagrams of the light emitted from positions B1 and B2 on the light-emitting unit being reflected by the coupling grating.
  • Figures 25A and 25B are schematic diagrams of optical components provided by an embodiment of the present application.
  • Figures 25A and 25B respectively show schematic diagrams of the light emitted from positions B1 and B2 on the light-emitting unit being reflected by the coupling grating.
  • Figures 26A and 26B are schematic diagrams of optical components provided by an embodiment of the present application.
  • Figures 26A and 26B respectively show schematic diagrams of the light emitted from positions B1 and B2 on the light-emitting unit being reflected by the coupling grating.
  • Figures 27A and 27B are schematic diagrams of optical components provided by an embodiment of the present application.
  • Figures 27A and 27B respectively show schematic diagrams of the light emitted from positions B1 and B2 on the light-emitting unit being reflected by the coupling grating.
  • Figure 28 schematically depicts the positional relationship between the three additional structures and the waveguide main structure.
  • Figure 29 schematically depicts the parameters of the optomechanical field of view.
  • Figure 30 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 31 is a schematic diagram of a two-dimensional grating dividing light into eight propagation directions.
  • FIG. 32 is a diagram of the outcoupled light efficiency of the optical waveguide shown in FIG. 31 .
  • Figure 33 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 34 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 35 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 36 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 37 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 38 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 39 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 40 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 41 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 42A is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 42B is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 43 is a schematic diagram of three different configurations of the virtual image distance and the visual distance difference corresponding to the virtual image on the virtual image plane generated by the optical waveguide provided by the present application.
  • Figure 44 is a schematic diagram of the eye movement space formed by the decoupling grating of the optical waveguide provided by an embodiment of the present application.
  • Figure 45 is the optical path principle diagram of the VAC phenomenon caused by wide beam imaging.
  • Figure 46 is a schematic diagram of the optical path for solving the VAC problem with thin beam imaging.
  • Figure 47 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • the coupling grating in the optical waveguide includes a structure of multiple sub-gratings.
  • FIG. 48 is a schematic diagram of the coupling grating of the optical waveguide shown in FIG. 47 .
  • Figure 49A shows the specific structural form of two sub-gratings provided by an embodiment of the present application.
  • Figure 49B shows the specific structural form of two sub-gratings provided by an embodiment of the present application.
  • Figure 50 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • the coupling grating in the optical waveguide includes a structure of multiple sub-gratings.
  • Figure 51 is a schematic diagram of an optical waveguide provided by an embodiment, in which grating structures are provided on both front and back sides of the waveguide substrate.
  • FIG. 52 is a schematic diagram of the grating structure on the front side of the waveguide substrate in FIG. 51 .
  • FIG. 53 is a schematic diagram of the grating structure on the reverse side of the waveguide substrate in FIG. 51 .
  • Figure 54 is a schematic diagram of two sub-gratings provided in an embodiment of the present application.
  • Figure 55 is a schematic diagram of an outcoupling grating of an optical waveguide provided by an embodiment of the present application.
  • Figure 56 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 57 is a schematic diagram of a near-eye display device provided by an embodiment of the present application.
  • FIG. 58 is a schematic diagram of the control architecture between the control unit and the outcoupling grating in the near-eye display device shown in FIG. 57 .
  • FIG. 59 shows the structure of the coupling grating in the embodiment shown in FIGS. 57 and 58 .
  • FIG. 60 is a schematic diagram of the sub-grating distribution structure in one working state of the coupling grating shown in FIG. 59 .
  • Figure 61 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 62 is an exploded schematic diagram of part of the grating structure and part of the waveguide substrate in Figure 61.
  • Figure 63 is a schematic diagram of the end face of the grating structure of the optical waveguide provided by an embodiment of the present application.
  • Figure 64 is a schematic graph comparing the incident angle and diffraction efficiency of a grating structure with sinusoidal gradient refractive index distribution and a grating structure with a single core structure.
  • Figure 65 is an exploded schematic diagram of part of the grating structure and part of the waveguide substrate of the optical waveguide provided by an embodiment of the present application.
  • Figure 66 is a schematic diagram of the second film layer in the grating structure of the optical waveguide provided by an embodiment of the present application.
  • Figure 67 is a schematic diagram of fabricating a core structure on a waveguide substrate.
  • Figure 68 is a schematic diagram of the three steps of completing the fabrication of the grating structure based on the structure shown in Figure 67.
  • Figure 69 is a schematic diagram of the core structure and film structure on the waveguide substrate of the optical waveguide provided by an embodiment of the present application.
  • Figure 70 is a schematic diagram of a grating structure on a waveguide substrate of an optical waveguide provided by an embodiment of the present application.
  • Figure 71 is a three-dimensional schematic view of an optical waveguide provided by an embodiment of the present application.
  • Figure 72 is a schematic plan view of an optical waveguide provided by an embodiment of the present application.
  • Figure 73 is a schematic plan view of an optical waveguide provided by an embodiment of the present application.
  • Figure 74 is a schematic plan view of an optical waveguide provided by an embodiment of the present application.
  • Figure 75 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 76 is a K-space schematic diagram of the grating period of an optical waveguide provided by an embodiment of the present application.
  • Figure 77 is a K-space schematic diagram of the grating period of an optical waveguide provided by an embodiment of the present application.
  • Figure 78 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 79 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 80 is a schematic diagram of the diffraction efficiency of a single grating of an optical waveguide provided by an embodiment of the present application.
  • Figure 81 is a schematic diagram of the wavelength bandwidth of an optical waveguide provided by an embodiment of the present application.
  • Figure 82 is a schematic diagram of the angular bandwidth of an optical waveguide provided by an embodiment of the present application.
  • Figure 83 is a schematic diagram of the manufacturing process of multiple exposures during the manufacturing process of the first grating layer or the second grating layer of the optical waveguide provided by an embodiment of the present application.
  • Figure 84 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 85 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 86 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 87 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 88 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 89 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 90 is an enlarged schematic diagram of part I in Figure 89.
  • Figure 91 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 92 is a schematic diagram of a common structure formed by an anti-reflection layer and a decoupling grating in an optical waveguide according to an embodiment of the present application.
  • Figure 93 is a schematic diagram of a common structure formed by an anti-reflection layer and a decoupling grating in an optical waveguide according to an embodiment of the present application.
  • Figure 94 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 95 is a schematic diagram of a specific manufacturing method for forming a unified structure composed of an anti-reflection layer and a grating structure.
  • Figure 96 is a flow chart of a method for manufacturing an optical waveguide according to an embodiment of the present application.
  • Figure 97 is a schematic diagram of the changes in each component during the double-beam exposure of the material layer during the manufacturing method of the optical waveguide provided by an embodiment of the present application.
  • Figure 98 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 99 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 100 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 101 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 102 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 103 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 104 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 105 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 106A is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 106B is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 106C is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 107 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 108 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 109 is a schematic flowchart of a method for manufacturing an optical waveguide according to an embodiment of the present application.
  • Figure 110 is a schematic flowchart of a method for manufacturing an optical waveguide according to an embodiment of the present application.
  • Figure 111 is a schematic flowchart of a method for manufacturing an optical waveguide according to an embodiment of the present application.
  • Figure 112 is a schematic flowchart of a method for manufacturing an optical waveguide according to an embodiment of the present application.
  • Figure 113 is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 114 is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 115 is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 116 is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 117 is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 118A is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 118B is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 118C is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 119 is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 120 is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 121 is a schematic cross-sectional structural diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 122 is a schematic plan view of an optical waveguide provided by an embodiment of the present application.
  • Figure 123 is a schematic cross-sectional structural diagram of the optical waveguide shown in Figure 122 at A-A.
  • FIG. 124 is another schematic cross-sectional structural diagram of the optical waveguide shown in FIG. 122 at A-A.
  • Figure 125 is a schematic plan view of an optical waveguide provided by an embodiment of the present application.
  • Figure 126 is a schematic cross-sectional structural diagram of the optical waveguide shown in Figure 125 at B-B.
  • Figure 127 is another sectional structural schematic diagram of the optical waveguide shown in Figure 125 at B-B.
  • Figure 128 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 129 is an exploded schematic diagram of the structure of each layer of the optical waveguide provided by an embodiment of the present application.
  • Figure 130 is a schematic diagram of the optical path of light propagating in the optical waveguide shown in Figure 129.
  • FIG. 131 is a schematic diagram of the division of the first region and the second region of the optical waveguide shown in FIG. 129 .
  • Figure 132 is a schematic structural diagram of the first grating layer provided by an embodiment of the present application.
  • Figure 133 is a schematic structural diagram of the first grating layer in some other embodiments.
  • Figure 134 is a schematic structural diagram of the second grating layer provided by an embodiment of the present application.
  • Figure 135 is a schematic structural diagram of the second grating layer in some other embodiments.
  • Figure 136 is a schematic structural diagram of the second grating layer in some other embodiments.
  • FIG. 137 is a schematic structural diagram of an optical waveguide composed of the first grating layer in FIG. 133 and the second grating layer in FIG. 135 .
  • FIG. 138 is a schematic structural diagram of an optical waveguide composed of the first grating layer in FIG. 132 and the second grating layer in FIG. 136 .
  • Figure 139 is a schematic structural diagram of an optical waveguide composed of the first grating layer in Figure 133 and the second grating layer in Figure 136.
  • Figure 140 is a flow chart of a method for manufacturing an optical waveguide provided by an embodiment of the present application.
  • FIG. 141 is a schematic diagram of the preparation of the first grating layer in step S1 in FIG. 140 .
  • FIG. 142 is a flow chart of the steps for making the second grating layer with the grating structure template in step S2 in FIG. 140 .
  • FIG. 143 is a schematic diagram of the preparation of the second grating layer in step S24 in FIG. 142 .
  • FIG. 144 is a flow chart of the steps of preparing the second grating layer with the grating structure template in step S2 in FIG. 140 in other embodiments.
  • FIG. 145 is a schematic diagram of the preparation of bonding the second grating layer of the grating structure template to the first grating layer through the adhesion promoter layer in step S24 in FIG. 144 .
  • Figure 146 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 147 is a schematic cross-sectional view of each hierarchical structure of an optical waveguide provided by an embodiment of the present application.
  • Figure 148 is an exploded schematic diagram of the hierarchical structure of the optical waveguide in Figure 147.
  • Figure 149 is a schematic cross-sectional view of a base and a refractive medium provided by a filling body layer according to an embodiment of the present application.
  • Figure 150 is a schematic cross-sectional view of an aerogel-filled main layer provided in an embodiment of the present application.
  • Figure 151 is a schematic cross-sectional view of a second anti-reflection layer provided by an embodiment of the present application and divided into multiple second anti-reflection sub-layers.
  • FIG. 152 is a schematic cross-sectional view of FIG. 151 including four second antireflection sublayers.
  • Figure 153 is a schematic cross-sectional view of a second anti-reflection layer provided in another embodiment of the present application and divided into multiple second anti-reflection sub-layers.
  • Figure 154 is a schematic cross-sectional view of the filling body layer and the second anti-reflection layer provided by an embodiment of the present application.
  • Figure 155 is a schematic cross-sectional view of the filling body layer and the second anti-reflection layer provided by another embodiment of the present application.
  • Figure 156 is a schematic cross-sectional view of an optical waveguide including an adhesion-promoting layer provided by an embodiment of the present application.
  • Figure 157 is a flow chart of a method for manufacturing an optical waveguide according to an embodiment of the present application.
  • Figure 158 is a schematic diagram of the preparation of the filling body layer in step S2 of Figure 157.
  • Figure 159 is a schematic diagram of the preparation of the refractive medium in step S21 of Figure 158.
  • Figure 160 is a flow chart of the preparation steps of filling the main body layer in step S2 of Figure 157.
  • Figure 161 is a schematic diagram of the preparation of another filling body layer in step S2 of Figure 157.
  • Figure 162 is a flow chart of preparation steps of another filling body layer in step S2 of Figure 157.
  • Figure 163 is a schematic diagram of the preparation of the second anti-reflection layer in step S3 of Figure 157.
  • Figure 164 is a flow chart of the preparation steps of the second anti-reflection layer in step S3 of Figure 157.
  • Figure 165 is a schematic diagram of the preparation of another second anti-reflection layer in step S3 of Figure 157.
  • Figure 166 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • FIG. 167 is a schematic diagram of the optical waveguide shown in FIG. 166 combined with the lens of the near-eye display device.
  • Figure 168 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 169 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 170 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 171 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 172A is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 172B is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 173A is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 173B is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 173C is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 174A is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 174B is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 175A is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 175B is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 175C is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 176A is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 176B is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 177 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 178A is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 178B is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 178C is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • Figure 179A is a schematic diagram of a manufacturing method of an optical waveguide provided by an embodiment of the present application.
  • Figure 179B is a schematic diagram of a method for manufacturing an optical waveguide provided by an embodiment of the present application.
  • Figure 180A is a schematic diagram of a manufacturing method of an optical waveguide provided by an embodiment of the present application.
  • Figure 180B is a schematic diagram of a method for manufacturing an optical waveguide according to an embodiment of the present application.
  • the following embodiments of the present application provide a near-eye display device, which may include but is not limited to an AR device.
  • the near-eye display device provided by this application is in the form of AR glasses, head-mounted devices, etc.
  • the near-eye display device of the present application will be described, taking the near-eye display device as AR glasses as an example.
  • FIG. 1 is a schematic diagram of a near-eye display device provided by an embodiment of the present application.
  • a near-eye display device 1000 includes a structural member 100 and an optical component 200 .
  • the structural member 100 is used to construct the overall shape structure of the near-eye display device 1000 and install internal optical devices and electronic devices.
  • the optical assembly 200 belongs to optical devices.
  • the structural member 100 includes a frame 102 and a temple, and the temple includes a right temple 101 and a left temple 103 .
  • the right temple 101 and the left temple 103 are respectively connected to both sides of the frame 102.
  • the connection between the temples and the frame 102 may be a rotational connection or a fixed connection.
  • the frame 102 When the user wears the near-eye display device 1000, the frame 102 is located in front of the user's eyes, and the temples (right temple 101 and left temple 103) rest on the user's ears.
  • the above-mentioned structure of the structural member 100 is only an example, and in other embodiments, it can be designed as needed.
  • the structural member can be a headband or a helmet of a head-mounted display device.
  • the optical assembly 200 includes a lens 10 and an optical machine 20.
  • the lens 10 is mounted to the frame 102 and is used to be worn directly in front of the human eye.
  • the lens 10 is light-transmissive, and has an optical waveguide 10A on the lens 10.
  • the optical waveguide 10A can be a diffractive optical waveguide structure.
  • all areas on the lens 10 are optical waveguides 10A, that is, the optical waveguides 10A constitute the lens of the near-eye display device 1000 .
  • the optical waveguide 10A may only constitute part of the lens 10 .
  • the optical waveguide 10A has a coupling grating 11 and a coupling grating 12.
  • the optical engine 20 is used to project light onto the optical waveguide 10A.
  • the optical engine 20 projects the light onto the coupling grating 11.
  • the light is coupled into the optical waveguide 10A through the coupling grating 11 and undergoes total reflection in the optical waveguide 10A.
  • the coupling grating 12 emits light, and the coupling grating 12 emits light to generate a virtual image and enter the human eye.
  • the optical engine 20 is located between the left lens 10L and the right lens 10R, and the optical engine 20 is located in the top area of the frame 102 .
  • the light emitted by the optical engine 20 includes two lines of light, one of which passes through the coupling grating 11 on the left lens 10L, enters the optical waveguide 10A on the left lens 10L, and then exits through the coupling grating 12 on the left lens 10L to form a virtual image.
  • Another path of light emitted by the optical engine 20 enters the optical waveguide 10A on the right lens 10R through the coupling grating 11 on the right lens 10R, and then exits through the coupling grating 12 on the right lens 10R to form a virtual image.
  • the optical engine 20 and the two coupling gratings 11 are located at the intersection of the left lens 10L and the right lens 10R, that is, the adjacent area.
  • FIG. 2 is a schematic diagram of a near-eye display device provided by another embodiment of the present application.
  • the structural member 100 of the near-eye display device provided by this embodiment is the same as the structural member 100 of the embodiment shown in FIG. 1 .
  • the number of optical engines 20 in the optical assembly 200 is two, and the two optical engines 20 are respectively located at or near the connection between the two temples and the frame.
  • One of the optical engines 20 is located at the connection position between the left temple leg 103 and the frame 102 or is located on the frame 10 close to the left temple 103.
  • the other optical engine 20 is located at the connection position between the right temple leg 101 and the frame 102 or is located on the frame 10 close to the right side.
  • One of the optical machines 20 is located above the left side of the left lens 10L, and the other optical machine 20 is located above the right side of the right lens 10R.
  • two coupling gratings 11 are respectively located at the upper left corner of the left lens 10L and the upper right corner of the right lens 10R.
  • the light emitted by the optical engine 20 passes through the coupling grating 11 on the left lens 10L, enters the optical waveguide 10A on the left lens 10L, and then exits through the coupling grating 12 on the left lens 10L to form a virtual image.
  • the light emitted by the optical engine 20 passes through the coupling grating 11 on the right lens 10R, enters the optical waveguide 10A on the right lens 10R, and then exits through the coupling grating 12 on the right lens 10R to form a virtual image.
  • FIG. 3 is a schematic diagram of the embodiment shown in FIG. 1 or the embodiment shown in FIG. 2 from another direction.
  • the frame 102 surrounds two light-transmitting areas 1021 and 1022 .
  • the two light-transmitting areas 1021 and 1022 face the left eye and the right eye respectively.
  • the left lens 10L and the right lens 10R are respectively provided corresponding to the two light-passing areas 1021 and 1022.
  • the space surrounded by the light-passing areas 1021 and 1022 is the optical waveguide 10A (or part of the optical waveguide 10A).
  • FIG. 4 is a schematic plan view of a near-eye display device provided in an embodiment.
  • the near-eye display device 1000 also includes an electronic component 300.
  • the electronic component 300 includes: a controller 301, a battery 302, a voice device 303, an antenna 304, a camera 305, and so on.
  • the number of optical engines 20 is two, one of which is located at the position of the right temple leg 101 adjacent to the optical waveguide 10A on the lens, and the other optical engine 20 is located at the position of the left temple leg 103 adjacent to the optical waveguide 10A on the lens.
  • the number of controllers 301 may also be two.
  • One controller 301 is located in the left temple 103 for driving the optical engine 20 installed at the left temple 103, and the other controller 301 is located on the right.
  • the temple 101 is used to drive the optical engine 20 installed at the right temple 101 position.
  • the controller 301 may be provided on the motherboard of the near-eye display device 1000 and may be the CPU of the near-eye display device 1000.
  • the controller 301 may be used to control the switch of the light machine 20.
  • the battery 302 is used to provide power for the near-eye display device 1000.
  • the number of the batteries 302 is also two, which are respectively located on the left temple 103 and the right temple 101.
  • the battery 302 is located at the end of the temple away from the lens. Convenient to charge.
  • a charging port can be set on the temples.
  • the number of cameras 305 is two. One camera 305 is located at the left edge of the left lens, and the other camera 305 is located at the right edge of the right lens.
  • the camera 305 can be connected to the image processor.
  • the camera 305 can be connected to the image processor. 305 is used to capture images and transmit them to the image processor, where the image information is processed by the image processor.
  • the near-eye display device 1000 can also be provided with electronic components such as memory, sensors, and positioning components.
  • the memory is used to store image information
  • the sensors can include power sensors (such as gyroscopes), biosensors, temperature sensors, and humidity sensors. wait.
  • the positioning component may include GPS or Beidou positioning equipment.
  • the embodiment of the present application provides an optical machine.
  • the optical machine is a self-luminous projection display system.
  • the optical machine is a light source for image display of a near-eye display device.
  • the light path emitted by the optical machine passes through the coupling grating of the optical waveguide. After entering the optical waveguide, the light is coupled out to the human eye by the coupling grating of the optical waveguide.
  • the coupled light forms a virtual image, so the human eye can see the virtual image.
  • the optical engine is a micro-display full-color optical engine, which can form a color image.
  • Figure 5 is a schematic diagram of an optical machine provided by an embodiment of the present application.
  • the optical engine 20 includes a light emitting unit 21 , a light combining unit 22 and an optical imaging unit 23 .
  • the light emitting unit 21 is located on the light entrance side of the light combining unit 22
  • the optical imaging unit 23 is located on the light exit side of the light combining unit 22 .
  • the light-emitting unit 21 is electrically connected to the controller 301, and the controller 301 can control the light-emitting unit 21 to switch on or off or perform data transmission with the light-emitting unit 21.
  • the light emitting unit 21 is the light source of the light machine 20 .
  • the light combining unit 22 is used to combine the monochromatic light emitted by the light emitting unit 21 to form a mixed beam.
  • the light combining unit 22 emits the mixed light beam to the optical imaging unit 23 .
  • the optical imaging unit 23 is used to receive signals from the light combining unit 22
  • the mixed light beam passes through the optical imaging unit 23 and then exits onto the coupling grating 11 of the optical waveguide 10A.
  • the optical imaging unit 23 may be a lens group, and the optical axis 23P of the optical imaging unit 23 may be the optical axis of the optical machine 20 .
  • the coupling grating 11 on the optical waveguide 10A is only schematically represented, and does not represent the specific structural form of the optical waveguide 10A and the coupling grating 11 .
  • the light-emitting unit 21 includes a first wavelength range emission unit 211, a second wavelength range emission unit 212, and a third wavelength range emission unit 213.
  • Both 212 and the third wavelength range emission unit 213 may be light-emitting chips, such as LED chips.
  • the first wavelength range emitting unit 211 is a red light unit, such as a red LED.
  • the second wavelength range emitting unit 212 is a blue light unit, such as a blue LED.
  • the third wavelength range emitting unit 213 is a green light unit, such as a green LED.
  • the first wavelength range emission unit 211 , the second wavelength range emission unit 212 and the third wavelength range emission unit 213 are respectively arranged at different light incident surface positions of the light combining unit 22 . It can be understood that the first wavelength range emission unit 211 The second wavelength range emission unit 212 and the third wavelength range emission unit 213 are arranged around the light combining unit 22. The light emitted by the first wavelength range emission unit 211, the second wavelength range emission unit 212 and the third wavelength range emission unit 213 is from Different directions enter the light combining unit 22 .
  • the light-emitting unit 21 is electrically connected to the controller 301 in the near-eye display device 1000 , and the controller 301 is used to turn on or off the light-emitting unit 21 .
  • the positional relationship between the components shown in Figure 5 does not represent the positional relationship between the light-emitting unit 21 and the light combining unit 22 in the assembled state provided in any embodiment.
  • the first wavelength in the light-emitting unit 21 is The positions of the range emission unit 211, the second wavelength range emission unit 212 and the third wavelength range emission unit 213 are moved so that they are separated from the light combining unit 22, so that Figure 5 forms an explosion between the light emitting unit 21 and the light combining unit 22. Schematic diagram of the decomposition state.
  • the light-emitting unit 21 includes a first flexible circuit board 214, a second flexible circuit board 215 and a third flexible circuit board 216.
  • the first flexible circuit board 214 is connected to the first wavelength range emission unit 211. and the controller 301
  • the second flexible circuit board 215 is connected between the second wavelength range transmitting unit 212 and the controller 301
  • the third flexible circuit board 216 is connected between the second wavelength range transmitting unit 212 and the controller 301. between the three-wavelength range transmitting unit 213 and the controller 301.
  • Figure 6 is a three-dimensional view of the light combining unit 22 provided by an embodiment of the present application.
  • the light combining unit 22 can have a hexahedral structure.
  • A, B, C, D, E, F, G and H represent the eight vertices of the light combining unit 22 .
  • the outer surface of the light combining unit 22 is composed of six outer surfaces of a hexahedral structure.
  • the four outer surfaces are respectively the first light incident surface S1, the second light incident surface S2, and the third light incident surface S3. and the light-emitting surface S4, and the other two outer surfaces are the non-light-incident surface S5.
  • the four vertices of the first light incident surface S1 are A, B, C, and D; the four vertices of the second light incident surface S2 are B, C, E, and H;
  • the four vertices of the third light incident surface S3 are C, D, F and E;
  • the four vertices of the light exit surface S4 are E, F, G and H;
  • the four vertices of one of the non-light incident surfaces S5 are A and B.
  • H, G the four vertices of the other non-light-incident surface S5 are A, D, F, and G.
  • This application does not limit the specific position of each light incident surface, as long as these three light incident surfaces correspond to light emitting units in different wavelength ranges (or different colors), and can ensure that the light incident from these three light incident surfaces to the light combining unit of light can A mixed light beam is synthesized in the light combining unit and emitted from the light exit surface S4.
  • the light combining unit 22 provided in the embodiment shown in FIG. 6 is formed by cutting a cubic optical element along two diagonal surfaces to form four prism structures.
  • the four vertices of one of the two diagonal surfaces are C, D, G, H; the four vertices of the other of the two diagonal surfaces are B, C, F, G; the two The intersection line of the diagonal surfaces is the body diagonal CG of the hexahedral structure.
  • Figure 7 is a three-dimensional exploded view of the light combining unit shown in Figure 6.
  • the specific structural form of the four prism structures can be seen more clearly from Figure 7.
  • These four prism structures are respectively the first prism unit 221, the second prism unit 222, the third prism unit 223 and the fourth prism unit 224.
  • These four prism structures are all special-shaped prisms.
  • the first prism unit 221, the The second prism unit 222 , the third prism unit 223 and the fourth prism unit 224 are all integrated prism structures, and the four are jointly spliced to form a hexahedral structure.
  • the first prism unit 221 and the third prism unit 223 have a pentahedral structure (pentahedral prism), and the second prism unit 222 and the fourth prism unit 224 have a tetrahedral structure (tetrahedral prism).
  • the first prism unit 221 includes five vertices A, B, C, D, and G.
  • the outer surface of the first prism unit 221 is composed of four triangular surfaces and one square surface; the second prism unit 221 includes five vertices A, B, C, D, and G.
  • the 222 includes four vertices C, D, G, F, and the outer surface of the second prism unit 222 is composed of four triangular surfaces; the third prism unit 223 includes five vertices C, E, F, G, H, and the third prism unit 223
  • the structural shape and size of the fourth prism unit 224 are the same as those of the first prism unit 221; the fourth prism unit 224 includes four vertices B, C, H, and G.
  • the structural shape and size of the fourth prism unit 224 are the same as those of the second prism unit 222.
  • a hexahedral structure can be provided first, and then the hexahedral structure can be cut, that is, cut along two diagonal planes. As shown in Figure 6, these two The diagonal surfaces are respectively the first diagonal surface S67 (the four vertices of the first diagonal surface S67 are C, D, G, and H) and the second diagonal surface S89 (the four vertices of the second diagonal surface S89 are B, C, G, F). After cutting, set the light splitting film at the corresponding position.
  • first prism unit 221, the second prism unit 222, the third prism unit 223 and the fourth prism unit 224 may also be manufactured separately, and then the first prism unit 221, the second prism unit 222, The third prism unit 223 and the fourth prism unit 224 are spliced, and the splicing process is combined with the light splitting film to form a light combining unit.
  • Figure 8 is an exploded view of a state of the light combining unit shown in Figure 6.
  • the docking structure formed by the docking of the first prism unit 221 and the second prism unit 222 is in the shape of a pentahedron
  • the third prism unit 223 The docking structure formed by docking with the fourth prism unit 224 is in the shape of a pentahedron, and both of the two pentahedral-shaped docking structures are half of the hexahedral structure.
  • the hexahedral structure is a cube.
  • the butt position between the first prism unit 221 and the second prism unit 222 is the first surface S6, and the butt position between the third prism unit 223 and the fourth prism unit 224 is the second surface S7.
  • the first surface S6 is in the shape of a triangle, and the three vertices of the first surface S6 are C, D, and G;
  • the second surface S7 is in the shape of a triangle, and the three vertices of the second surface S7 are C, H, and G.
  • Figure 9 is an exploded view of a state of the light combining unit shown in Figure 6.
  • the docking structure formed by the docking of the first prism unit 221 and the fourth prism unit 224 is in the shape of a tetrahedron
  • the second prism unit The docking structure formed by the docking of 222 and the third prism unit 223 is in the shape of a tetrahedron, and both of the two tetrahedral docking structures are half of the hexahedral structure.
  • the butt position between the first prism unit 221 and the fourth prism unit 224 is the third surface S8, and the butt position between the second prism unit 222 and the third prism unit 223 is the fourth surface S9. .
  • the third surface S8 is in the shape of a triangle, and the three vertices of the third surface S8 are B, C, and G;
  • the fourth surface S9 is in the shape of a triangle, and the three vertices of the fourth surface S9 are C, G, and F.
  • the first surface S6 and the second surface S7 constitute the first diagonal surface S67 of the hexahedral structure (the four vertices of the first diagonal surface S67 are C, D, G, H), the third surface S8 and the fourth surface S9 constitute the second diagonal surface S89 of the hexahedral structure (the four vertices of the second diagonal surface S89 are B, C, G, F), the intersection line L1 between the first diagonal surface S67 and the second diagonal surface S89 is the body diagonal of the hexahedral structure, and the two vertices of the intersection line L1 are C and G.
  • the first surface S6 and the second surface S7 are provided with a first dichroic film 225
  • the third surface S8 and the fourth surface S9 are provided with a second dichroic film 226
  • FIG. 8 the rectangle with vertices B, C, G, and F is schematically represented as the second dichroic film 226
  • the rectangle with vertices C, D, G, and H is schematically represented as the first dichroic film 225 .
  • the first dichroic film 225 can completely cover the first surface S6 and the second surface S7.
  • the size and shape of the first dichroic film 225 can also be adjusted according to needs, for example 225 may only cover part of the first surface S6 and the second surface S7, or the shape of the first dichroic film 225 may be other shapes (such as a circle, a polygon, etc.).
  • the second dichroic film 226 can completely cover the third surface S8 and the fourth surface S9.
  • the size and shape of the second dichroic film 226 can also be adjusted according to needs, for example, the second dichroic film 226 can completely cover the third surface S8 and the fourth surface S9.
  • the dichroic film 226 may only cover part of the third surface S8 and the fourth surface S9, or the shape of the second dichroic film 226 may be other shapes (eg, circular, polygonal, etc.).
  • the first dichroic film 225 and the second dichroic film 226 are used to reflect light in different wavelength ranges. Alternatively, the first dichroic film 225 and the second dichroic film 226 are used to reflect light of different colors. In this application, the first dichroic film 225 is provided on the first diagonal surface S67 and the second dichroic film 226 is provided on the second diagonal surface S89.
  • the light splitting film 225 and the second light splitting film 226 can split light in different wavelength ranges, so that after entering the light combining unit 22 , the light in three different wavelength ranges can be combined to form a mixed light beam, and emitted from the light exit surface S4 .
  • light in different wavelength ranges can be of different colors. light.
  • the second light-splitting film 226 includes two sub-films. Specifically, the two sub-films are triangular in shape, namely sub-film BCG and sub-film CGF. As shown in FIG. 9 , the first light-splitting film 225 has an integrated structure, that is, the first light-splitting film 225 has a rectangular structure. In this embodiment, during the process of splicing the first prism unit 221 and the fourth prism unit 224, a sub-film BCG of the second dichroic film 226 is disposed between the first prism unit 221 and the fourth prism unit 224.
  • a sub-film CGF of the second dichroic film 226 is disposed between the second prism unit 222 and the third prism unit 223 . That is, the exploded view shown in FIG. 9 is formed, and then the two separated prism groups shown in FIG. 9 are docked. During the docking process, the first light splitting film 225 is set at the docking position.
  • the dichroic film designed in this solution is used in a light combining unit composed of four prisms. Since the first dichroic film 225 can be an integrated structure, it has the advantages of simple structure and convenient assembly.
  • the first light-splitting film 225 has a structure of two sub-films
  • the second light-splitting film 226 has an integrated structure.
  • both the first light-splitting film 225 and the second light-splitting film 226 can be a structure composed of two sub-films.
  • FIG. 10A is a three-dimensional schematic diagram of the optical engine 20 provided by an embodiment of the present application.
  • FIG. 10A schematically expresses the specific positional relationship between the light combining unit 22 and the light emitting unit 21 in the optical engine 20 shown in FIG. 6 .
  • the light emitting unit 21 includes a first wavelength range emitting unit 211 , a second wavelength range emitting unit 212 and a third wavelength range emitting unit 213 , a first flexible circuit board 214 , a second flexible circuit board 215 and a third Flexible circuit board 216.
  • the first wavelength range emitting unit 211 is facing the first light incident surface S1 of the hexahedral structure of the light combining unit 22 (the front side of the light combining unit 22 in FIG. 10A ), and the second wavelength range emitting unit 212 is facing For the second light incident surface S2 of the hexahedral structure of the light combining unit 22 (the bottom surface of the light combining unit 22 in FIG. 10A ), the third wavelength range emitting unit 312 is facing all sides of the light combining unit 22 .
  • the third light incident surface S3 of the hexahedral structure (the left side of the light combining unit 22 in FIG. 10A).
  • the first light incident surface S1, the second light incident surface S2 and the third light incident surface S3 are arranged perpendicular to each other and adjacent to each other, and the three respectively correspond to three of the hexahedral structures. outer surfaces adjacent to each other.
  • the normal direction A1 of the light-emitting surface of the first wavelength range emitting unit 211 and the normal direction A2 of the light-emitting surface of the second wavelength range emitting unit 212 are both perpendicular to the optical imaging unit 23 of the optical machine 20
  • the normal direction A3 of the light-emitting surface of the third wavelength range emission unit 212 is the same as the optical axis 23P of the optical imaging unit 23 of the optical machine 20 .
  • the first light splitting film 225 is used to reflect light in the first wavelength range and transmit light in the second wavelength range and light in the third wavelength range.
  • the first light-splitting film 225 is a red-reflecting and blue-green film layer. All the red light emitted by the first wavelength range emitting unit 211 will be transmitted to the first dichroic film 225.
  • the first dichroic film 225 reflects the red light, so that the red light is reflected and emits out of the light exit surface S4 along the direction of the optical axis 23P. , and enters the optical imaging unit 23.
  • the second light splitting film 226 is used to reflect light in the second wavelength range and transmit light in the first wavelength range and light in the third wavelength range.
  • the second dichroic film 226 is a blue-reflective, red-green, and translucent film layer. All the blue light emitted by the second wavelength range emission unit 212 will be transmitted to the second dichroic film 226.
  • the second dichroic film 226 The blue light is reflected, so that the blue light is reflected and then emitted from the light exit surface S4 along the direction of the optical axis 23P, and enters the optical imaging unit 23 .
  • Imaging unit 23 The three colors of light are emitted from the light exit surface S4 and are emitted along the direction of the optical axis 23P to form a mixed light beam.
  • the extension direction of the second flexible circuit board 215 in the optical machine 20 provided by the embodiment shown in FIG. 10A is similar or the same as the direction of the optical axis 23P. Refer to FIGS. 1, 2 and 3 in combination.
  • the second flexible circuit board 215 can extend along the structural member 100 without folding the second flexible circuit board 215 , that is, it extends along the structural member without bending, which is beneficial to reducing the size of the entire device. It is understandable that if the flexible circuit board is folded, the overall size of the optical machine will become larger due to the folding of the flexible circuit board, which will take up more space in a near-eye display device.
  • the optical machine provided by this application includes the aforementioned light combining unit, the optical machine has a more flexible configuration scheme, so that the optical machine can be configured in more environments in near-eye display devices.
  • the temple When the optical engine 20 provided in the embodiment shown in FIG. 10A is installed on the temple of the structural member, the temple includes an inner side and an outer side.
  • the inner side of the temple is the part of the near-eye display device that is close to the human face when worn, and the outer side is The side is the part of the near-eye display device that is far away from the human face when worn.
  • the present application places the first wavelength range emitting unit 211 close to the outer side of the temple, and a non-light incident surface S5 (specifically, a non-light incident surface S5 arranged opposite to the first light incident surface S1) on the light combining unit 22.
  • the light-incident surface S5) is close to the inner side of the temple.
  • the near-eye display device does not have a light-emitting unit on the side close to the face, which can reduce the risk of users sensing heat and improve the user experience.
  • the second wavelength range emitting unit 212 can also be disposed close to the outer side of the temples, and the non-light incident surface S5 located on the top surface of the light combining unit 22 is close to the inner side of the temples.
  • the optical engine 20 provided in the embodiment shown in FIG. 10A is installed on the temple of the structural member, the light exit side of the optical engine 20 is the optical waveguide on the lens of the near-eye display device. In the manner shown in FIG.
  • the second wavelength range emission unit 212 is located on the bottom side of the light combining unit 22 , which can make the blue light energy at the exit pupil of the optical machine weaker at the top and stronger at the lower end.
  • the specific structure of the optical machine 20 is related to the light source.
  • the combination of the waveguide structure can make the optical waveguide utilize the stronger part of the blue light and improve the light efficiency.
  • the second wavelength range emission unit 212 is placed close to the relay area of the optical waveguide (ie, the relay grating). Therefore, this solution can improve the light efficiency of the near-eye display device.
  • the light combining unit 22 is composed of a prism, and an optical film layer is provided on the prism, such as a first dichroic film and a second dichroic film. Since the transmittance or reflectivity of each film layer is different, There are differences in the angle of incidence. For example, the greater the angle incident on the dichroic film (i.e., the dichroic slope of the prism), the lower the light efficiency. The angle refers to the angle between the light and the normal line of the dichroic film. Therefore, the light intensity distribution at the exit pupil of the optical machine is uneven.
  • Figure 10B shows a schematic diagram of the optical path of the second wavelength range emission unit 212 in the embodiment provided in Figure 10A.
  • the light emitted by the second wavelength range emitting unit 212 is blue light.
  • the second wavelength range emitting unit 212 enters the light combining unit 22 and is reflected by the second dichroic film 226.
  • the angle of the light reflected from the lower left corner of the second dichroic film 226 is smaller, and the upper right part of the second dichroic film 226
  • the angle of light reflected in the corner part is larger, and the light effect in the upper right corner part is lower.
  • the light partially reflected from the upper right corner of the second dichroic film 226 will be partially reflected after passing through the optical imaging unit 23 and projected onto the coupling grating 11.
  • the reflected light is represented by a dotted line in FIG. 10B.
  • the coupling grating 11 includes a first coupling area 11C and a second coupling area 11D. As shown in FIG. 10B , in one embodiment, the first coupling area 11C is located above the second coupling area. It can be understood that FIG. 10B only schematically encircles the first coupling area 11C and the second coupling area 11D with a rectangular dotted frame. In actual application, the specific details of the first coupling area 11C and the second coupling area 11D are The position of is not limited to the solution shown in FIG.
  • the first coupling area 11C and the second coupling area 11D may be connected or partially overlapped. This application only uses FIG. 10B to express that the first coupling area 11C is an area with lower energy of incident light, and the second coupling area 11D is an area with higher energy of incident light.
  • the second wavelength range emitting unit 212 is arranged in a position such that more energy of the light projected by the second wavelength range emitting unit 212 is concentrated to the second coupling region 11D of the coupling grating 11 .
  • FIG. 10C is a schematic diagram of an optical waveguide provided in an embodiment, expressing the positional relationship between the coupling grating 11 in FIG. 10B and other gratings on the optical waveguide plane.
  • the optical waveguide 10A includes a coupling grating 11 , a relay grating 13 and an coupling grating 12 .
  • the second coupling area D of the coupling grating 11 is arranged adjacent to the relay grating 13 , that is, the first coupling area 11C is located on the side away from the relay grating 13 .
  • the arrangement direction of the optical machine provided in this application combined with the arrangement of the coupling grating 11, can improve the utilization rate of the light sent by the second wavelength range emission unit 212.
  • the optical waveguide does not fully utilize the light at the exit pupil of the optical machine.
  • the light that is far away from the relay grating will be re-reflected back to the optical machine, forming a ghost image.
  • the present application can place the second wavelength range emitting unit 212 (for example, a light emitting unit for emitting blue light) close to the relay area of the optical waveguide, which can improve the overall light efficiency.
  • Figure 11 is a three-dimensional schematic diagram of an optical machine provided by an embodiment of the present application.
  • the implementation shown in Figure 11 is based on the implementation shown in Figure 10A.
  • the second wavelength range transmitting unit 212 and the first wavelength range The transmitting units 211 exchange positions.
  • the first wavelength range emitting unit 211 is located on the bottom side of the light combining unit 22
  • the second wavelength range emitting unit 212 is located on the front side of the light combining unit 22 .
  • the first dichroic film 225 is a blue-reflective, red-green, and translucent film layer, and all the blue light emitted by the second wavelength range emission unit 212 will be transmitted to the first dichroic film 225.
  • the first dichroic film 225 The blue light is reflected, so that the blue light is reflected and then emitted from the light exit surface S4 along the direction of the optical axis 23P, and enters the optical imaging unit 23 .
  • the second dichroic film 226 is an anti-red and translucent blue-green film layer. All the red light emitted by the first wavelength range emission unit 211 will be transmitted to the second dichroic film 226.
  • the second dichroic film 226 reflects the red light, so that the red light After being reflected, it exits the light exit surface S4 along the direction of the optical axis 23P and enters the optical imaging unit 23 .
  • the extension direction of the first flexible circuit board 214 is similar or the same as the direction of the optical axis 23P.
  • the first flexible circuit board 214 can extend along the structural member 100, and there is no need to fold the first flexible circuit board 214, which is beneficial to reducing the size of the entire machine.
  • the position of the non-light incident surface S5 of the light combining unit 22 is the same as the position of the non-light incident surface S5 in the embodiment shown in FIG. 10A , and both are located on the top side and back of the light combining unit 22 .
  • side (the back side is the side opposite to the first light incident surface S1).
  • the second wavelength range emitting unit 212 or the first wavelength range emitting unit 211 can be placed close to the outer side of the temples, so as to ensure that the near-eye display device is positioned close to the face. There is no light-emitting unit on the side, which reduces the risk of users sensing heat and improves the user experience.
  • Figure 12 is a three-dimensional schematic diagram of an optical machine provided by an embodiment of the present application. This embodiment is based on the embodiment shown in Figure 10A.
  • the position of the second wavelength range emission unit 212 is adjusted to the second wavelength range.
  • the emission unit 212 is placed on the top side of the light combining unit 22 (in the embodiment shown in FIG. 10A , the second wavelength range emission unit 212 is located on the bottom side of the light combining unit 22).
  • the position of the second wavelength range emitting unit 212 together with the second flexible circuit board 215 is moved upward from the top side of the light combining unit 22.
  • the state shown in Figure 12 is the second
  • the separation state between the wavelength range emission unit 212 and the light combining unit 22 is not the positional relationship in the assembled state of the optical machine.
  • the position of the second dichroic film 226 is also adjusted adaptively.
  • the second light-splitting film 226 is a blue-reflecting, red-green, and translucent film layer
  • the first light-splitting film 225 is a red-reflecting, blue-green film layer.
  • the specific light-splitting principle is the same as the embodiment shown in FIG. 10A .
  • there is no intersection between the second flexible circuit board 215 and the third flexible circuit board 216 so that the arrangement of the two in the structural member of the near-eye display device can be more flexible.
  • the second light incident surface S2 of the light combining unit 22 is located on the top side of the light combining unit 22
  • the non-light incident surface of the light combining unit 22 is located on the bottom side and back of the light combining unit 22 .
  • side (although not numbered, it is easy to understand that it is the corresponding surface where the light-emitting unit is not provided).
  • the second wavelength range emitting unit 212 or the first wavelength range emitting unit 211 can be placed close to the outer side of the temple. position to ensure that the near-eye display device does not have a light-emitting unit on the side close to the face, reducing the risk of users sensing heat and improving the user experience.
  • the first wavelength range transmitting unit and the second wavelength range transmitting unit need to be
  • the AA direction of the range emission unit is aligned with the third wavelength range emission unit, that is, the direction of the long side and the short side is adjusted.
  • the AA area refers to the active area, which is the effective pixel area, and is rectangular, including the long side and the short side.
  • the long side of the third wavelength range emitting unit 213 is along the horizontal direction and the short side is along the vertical direction.
  • the long side of the first wavelength range emitting unit 211 is parallel to the optical axis and the short side is along the vertical direction.
  • the second wavelength The long side of the range emission unit 212 is perpendicular to the optical axis, and the short side is parallel to the optical axis. If the long side and short side of the AA area are equal in length and the number of pixels is equal, the first wavelength range emitting unit 211 can also extend the first flexible circuit board 214 along the structural member 100 .
  • the image projected by the first wavelength range emission unit 211, the image projected by the second wavelength range emission unit 212, and the upper image projected by the third wavelength range emission unit 213 are consistent. It can be understood that the images projected by each light-emitting unit are combined. After the light unit is turned, the directions of the images formed are consistent. As shown in Figure 12, the image projected by the first wavelength range emitting unit 211 remains consistent with the upper image projected by the third wavelength range emitting unit 213 after being combined by the light combining unit. Similarly, the image projected by the second wavelength range emitting unit 212 is combined. The light unit is also consistent with the upper image projected by the third wavelength range emission unit 213.
  • the light combining unit provided in this application can be flexibly configured with the light emitting unit.
  • the three specific implementations provided in Figure 10A, Figure 11 and Figure 12 all use the light combining unit shown in Figure 6.
  • the light combining unit can be adjusted by adjusting the first wavelength.
  • the positions of the range emission unit and the second wavelength range emission unit constitute different configuration schemes. This application only schematically lists these three specific implementation modes. In the specific application process, it is not limited to these three specific configuration solutions, and the configuration solutions can have more possibilities.
  • Figure 13 is a three-dimensional view of the light combining unit 22 provided by an embodiment of the present application.
  • the light combining unit 22 can have a hexahedral structure.
  • A, B, C, D, E, F, G and H represent the eight vertices of the light combining unit 22 .
  • the outer surface of the light combining unit 22 is composed of six outer surfaces of a hexahedral structure. In one embodiment, the four outer surfaces are respectively the first light incident surface S1, the second light incident surface S2, and the third light incident surface S3.
  • the four vertices of the first light incident surface S1 are A, D, F, and G, that is, the first light incident surface S1 is the top side of the hexahedral structure shown in Figure 13;
  • the four vertices of the second light incident surface S2 are B, C, E, and H.
  • the second light incident surface S2 is the bottom side of the hexahedral structure shown in Figure 13;
  • the four vertices of the third light incident surface S3 are C, D, F, and E, that is, the third light incident surface is the front side of the hexahedral structure shown in Figure 13;
  • the four vertices of the light exit surface S4 are E, F, G, and H, that is, the light exit surface S4 is The right side of the hexahedral structure shown in 13;
  • the four vertices of one non-light incident surface S5 (the non-light incident surface located adjacent to the light exit surface S4) are A, B, H, and G;
  • the four vertices of surface S5 are A, B, C, and D.
  • This application does not limit the specific position of each light incident surface, as long as the three light incident surfaces correspond to light-emitting units of different colors, and it can ensure that the light incident from these three light incident surfaces to the light combining unit can be combined.
  • a mixed beam is synthesized in the unit and emitted from the light exit surface S4.
  • the embodiment shown in Fig. 13 is based on the embodiment shown in Fig. 6 and is cut once along the diagonal plane.
  • the embodiment shown in Figure 6 is to form four independent prism units on the hexahedral structure along the first diagonal surface S67 and the second diagonal surface S89 respectively.
  • the implementation shown in Figure 13 is to form four independent prism units on the hexahedral structure along the first diagonal surface S67 and the second diagonal surface S89.
  • Eight prism structures are formed by cutting along the first diagonal surface S67, the second diagonal surface S89 and the third diagonal surface S10.
  • the intersection line L1 between the first diagonal surface S67 and the second diagonal surface S89 is the body diagonal of the hexahedral structure, and the two vertices of the intersection line L1 are C and G.
  • intersection line L2 between the first diagonal surface S67 and the third diagonal surface S10 is the body diagonal of the hexahedral structure, and the two vertices of the intersection line L2 are D and H.
  • the intersection line L3 between the second diagonal surface S89 and the third diagonal surface S10 is the center line of the hexahedral structure.
  • the two vertices of the intersection line L3 are Q1 and Q2.
  • the length of the intersection line L3 is equal to the hexahedral structure.
  • the edge length is, in this embodiment, the hexahedral structure is a cube, and all its edge lengths are equal.
  • FIG. 14 is an exploded perspective view of the light combining unit shown in FIG. 13 .
  • this embodiment is based on the embodiment shown in FIG. 6 and then cuts along the third diagonal plane S10 , so that the first prism unit 221 is divided into a first sub-prism 2211 and a third sub-prism 2211 .
  • Second son Prism 2212 so that the second prism unit 222 is divided into a third sub-prism 2221 and a fourth sub-prism 2222, so that the third prism unit 223 is divided into a fifth sub-prism 2231 and a sixth sub-prism 2232, so that the fourth prism unit 224 It is divided into a seventh sub-prism 2241 and an eighth sub-prism 2242.
  • the butt position between the first sub-prism 2211 and the second sub-prism 2212 is the first sub-surface S101.
  • the first sub-surface S101 is a quadrilateral, and both the first sub-prism 2211 and the second sub-prism 2212 are pentahedral prisms.
  • the butt position between the third sub-prism 2221 and the fourth sub-prism 2222 is the second sub-surface S102, the second sub-surface S102 is triangular, the third sub-prism 2221 is a pentahedral prism, and the fourth sub-prism 2222 is a tetrahedral prism.
  • the butt position between the fifth sub-prism 2231 and the sixth sub-prism 2232 is the third sub-surface S103.
  • the third sub-surface S103 is a quadrilateral, and both the fifth sub-prism 2231 and the sixth sub-prism 2232 are pentahedral prisms.
  • the joint position between the seventh sub-prism 2241 and the eighth sub-prism 2242 is the fourth sub-surface S104.
  • the fourth sub-surface S1042 is triangular.
  • the seventh sub-prism 2241 is a pentahedral prism.
  • the octagonal prism 2242 is a tetrahedral prism.
  • the first sub-surface S101, the second sub-surface S102, the third sub-surface S103 and the fourth sub-surface S104 constitute the third diagonal surface S10 of the hexahedral structure.
  • FIG. 15 is a three-dimensional exploded schematic diagram of a state of the light combining unit 22 shown in FIG. 13 .
  • the state shown in FIG. 15 is based on the state shown in FIG. 14 , with the first prism unit 221 and the second prism unit 221 .
  • the prism unit 222, the third prism unit 223 and the fourth prism unit 224 are all shown as a whole, that is, the first sub-prism 2211 and the second sub-prism 2212 are connected, the third sub-prism 2221 and the fourth sub-prism 2222 are connected, and the fifth sub-prism 2211 and the fourth sub-prism 2222 are connected.
  • the prism 2231 and the sixth sub-prism 2232 are butt-jointed, and the seventh sub-prism 2241 and the eighth sub-prism 2242 are butt-jointed. Comparing Figure 15 and Figure 7, it can be found that the overall appearance of the first prism unit 221, the overall appearance of the second prism unit 222, the overall appearance of the third prism unit 223 and the fourth prism unit 224 in the light combining unit shown in Figure 15 The overall appearance is the same structural form as the corresponding features in Figure 7.
  • the light combining unit 22 shown in FIG. 13 includes three light-splitting films, namely a first light-splitting film 225, a second light-splitting film 226, and a third light-splitting film 227.
  • three light-splitting films namely a first light-splitting film 225, a second light-splitting film 226, and a third light-splitting film 227.
  • Figure 16, Figure 17 and Figure 18 respectively show the locations of the three light splitting films.
  • Figure 16, Figure 17 and Figure 18 respectively show the positions of the three dichroic films.
  • the first dichroic film 225, the second dichroic film 226 and the third dichroic film 227 are separated from the light combining unit 22 and shown separately. These three dichroic films are all rectangular structures.
  • the first dichroic film 225 is located at the first diagonal surface S67 , and the area of the first dichroic film 225 may be equal to the area of the first diagonal surface S67 (as shown in FIG. 16 ). In other embodiments, the area of the first dichroic film 225 may be smaller than the area of the first diagonal surface S67. It is understood that the shape of the first dichroic film 225 may also be different from the shape of the first diagonal surface S67. As shown in FIG.
  • the second dichroic film 226 is located at the second diagonal surface S89 , and the area of the second dichroic film 226 may be equal to the area of the second diagonal surface S89 .
  • the third dichroic film 227 is located at the third diagonal surface S10 , and the area of the third dichroic film 227 may be equal to the area of the third diagonal surface S10 .
  • the third dichroic film 227 , the first dichroic film 225 and the second dichroic film 226 are respectively used to reflect light in different wavelength ranges.
  • the first light splitting film 225 is used to reflect the light in the third wavelength range, and transmit the light in the first wavelength range and the light in the second wavelength range.
  • the first light-splitting film 225 is a green-reflective, red-blue, translucent film layer.
  • the second dichroic film 226 reflects the light in the second wavelength range, and transmits the light in the first wavelength range and the light in the third wavelength range.
  • the second dichroic film 226 is a blue-reflecting, red-green, translucent film layer.
  • the third dichroic film 227 reflects the light in the first wavelength range and transmits the light in the second wavelength range and the light in the third wavelength range.
  • the third dichroic film 227 is a red-reflecting, blue-green film layer.
  • the second light-splitting film 226 and the third light-splitting film 227 each include four sub-films, as shown in Figures 17 and 18. Among the four sub-films, two are triangular in shape, and the other two are triangular in shape. It is trapezoidal.
  • the first light splitting film 225 has an integrated structure and is rectangular. This plan limits the specific structures of the second dichroic film 226 and the third dichroic film 227, and the plan that the first dichroic film 225 is an integrated structure.
  • the dichroic film designed in this plan is applied to a light combining unit composed of eight prisms. Among them, since the first light-splitting film can be an integrated structure, it has the advantages of simple structure and convenient assembly.
  • FIG. 19 is a three-dimensional schematic diagram of the optical engine 20 provided by an embodiment of the present application.
  • FIG. 19 schematically expresses the specific positional relationship between the light combining unit shown in FIG. 13 and the light-emitting unit in the optical engine 20 .
  • the light emitting unit 21 includes a first wavelength range emitting unit 211, a second wavelength range emitting unit 212, a third wavelength range emitting unit 213, a first flexible circuit board 214, a second flexible circuit board 215 and a third Flexible circuit board 216.
  • the first wavelength range transmitting unit 211 and the second wavelength range transmitting unit 212 are disposed oppositely on two opposite sides of the light combining unit 22, and the third wavelength range transmitting unit 213 is located between the first wavelength range transmitting unit 211 and the second wavelength range transmitting unit 211. between units 212.
  • Figure 20 is a plan view of the optical machine shown in Figure 19 in one direction.
  • Figure 21 is an exploded schematic diagram of the light combining unit and the light emitting unit in the optical machine shown in Figure 19. Combining Figures 19, 20 and 21, it can be clearly understood The positional relationship between the light combining unit 22 and the light emitting unit 21 is expressed graphically.
  • the light-emitting surface of the first wavelength range emitting unit 211 faces the first light incident surface S1 of the hexahedral structure of the light combining unit 22, and the light-emitting surface of the second wavelength range emitting unit 212 faces the combined light unit 22.
  • the second light incident surface S2 of the hexahedral structure of the light unit 22 and the light emitting surface of the third wavelength range emission unit 213 are facing the third light incident surface S3 of the hexahedral structure of the light combining unit 22, so The first light incident surface S1 and the second light incident surface S2 are parallel to each other, and the third light incident surface S3 is perpendicular to the first light incident surface S1.
  • the normal direction A1 of the light-emitting surface of the first wavelength range emitting unit 211 and the normal direction A1 of the light-emitting surface of the second wavelength range emitting unit 213 The normal direction A2 is the same direction, and the normal direction A3 of the light-emitting surface of the third wavelength range emitting unit 213 is perpendicular to the normal direction A1 of the light-emitting surface of the first wavelength range emitting unit 211 .
  • the extension directions of the first flexible circuit board 214, the second flexible circuit board 215, and the third flexible circuit board 216 in the optical machine 20 provided by the embodiment shown in FIG. 19 are similar or the same as the direction of the optical axis 23P.
  • FIG. 1 Figure 2 and Figure 3.
  • the second flexible circuit board 215 can extend along the structural member 100. There is no need to fold the second flexible circuit board 215, which is beneficial to the overall size of the device. decrease.
  • the temple When the optical engine 20 provided in the embodiment shown in Figure 19 is installed on the temple of the structural member, the temple includes an inner side and an outer side.
  • the inner side of the temple is the part of the near-eye display device that is close to the human face when worn, and the outer side is The side is the part of the near-eye display device that is far away from the human face when worn.
  • the present application places the third wavelength range emitting unit 213 close to the outer side of the temple, and a non-light incident surface S5 (specifically, a non-light incident surface S5 arranged opposite to the third light incident surface S3) on the light combining unit 22.
  • the light-incident surface S5 (as shown in Figure 21) is close to the inner side of the temples.
  • Such a setting means that the near-eye display device does not have a light-emitting unit on the side close to the face, which can reduce the risk of users sensing heat and improve user use. sense of experience.
  • the light exit side of the optical engine 20 is the optical waveguide on the lens of the near-eye display device.
  • the second wavelength range emitting unit 212 can be located on the bottom side of the light combining unit 22
  • the first wavelength range emitting unit 211 can be located on the top side of the light combining unit 22 .
  • the second wavelength range emitting unit 212 is located on the bottom side of the light combining unit 22, which can make the blue light energy at the exit pupil of the optical machine weak at the top and strong at the bottom.
  • the specific structure of the optical machine 20 is used in conjunction with the structure of the optical waveguide, so that the optical waveguide can be utilized to the stronger part of blue light to improve light efficiency.
  • the second wavelength range emission unit 212 is placed close to the relay area of the optical waveguide (ie, the relay grating). Therefore, this solution can improve the light efficiency of the near-eye display device.
  • Figures 19 to 21 only schematically describe an arrangement scheme between the light emitting unit and the light combining unit.
  • the light combining unit shown in Figure 13 since the light combining unit 13 includes 8 mutually independent prism structures, Moreover, it is formed by cutting along the third diagonal plane on the basis of the four prisms shown in Figure 6.
  • the light combining unit shown in Figure 6 can realize all possible positional relationships between the light-emitting unit and the light-emitting unit in the optical machine.
  • Flexible layout solutions are applicable to the light combining unit shown in Figure 13. That is, the layout scheme of the light combining unit and the light emitting unit in the optical machine shown in Figure 10A, Figure 11 and Figure 12 is also applicable to the light combining unit shown in Figure 13. It is only necessary to adjust the properties of each light splitting film according to the specific layout plan. .
  • the present application provides that the light combining unit 22 has a cubic structure as a whole.
  • the cubic structure is designed so that the light sources of different colors in the light-emitting unit (i.e., the first wavelength range emission unit 211, the second wavelength range emission unit 212 and the third wavelength range emission unit 211)
  • the optical path of the three-wavelength range emission unit 213) from the light entrance surface to the light exit surface can be kept consistent, that is, the red light emitted by the first wavelength range emission unit, the blue light emitted by the second wavelength range emission unit and the third wavelength
  • the length of the transmission path of the green light emitted by the range emission unit in the light combining unit is the same.
  • the transmission path of the light is the optical path.
  • the same optical path is beneficial to ensuring the clarity of the optical-mechanical imaging. If the optical path of a certain color of light is inconsistent with the optical path of other colors of light, the clarity of the image projected by the light machine will be poor and the image will be blurry.
  • the area of the light incident surface of the light combining unit 22 is larger than the area of the light emitting surface of the corresponding light emitting unit. This ensures that more light emitted by the light emitting unit enters the light combining unit and improves the efficiency of light transmission.
  • the area of the light incident surface of the optical imaging unit is larger than the area of the light exit surface of the light combining unit. This ensures that more light emitted from the light combining unit enters the optical imaging unit and improves the efficiency of light transmission.
  • the optical imaging unit may be a lens group, that is, it may be composed of one or more lenses.
  • the direction in which the mixed light beam is emitted may be the direction of the optical axis of the optical imaging unit.
  • the light combining unit provided by the present application can be based on a hexahedral optical structure, which is first cut, that is, cut along the diagonal plane.
  • a hexahedral optical structure which is first cut, that is, cut along the diagonal plane.
  • the light combining unit 22 shown in FIG. 6 it needs to be cut at the first diagonal.
  • the light combining unit 22 shown in FIG. 13 it is necessary to cut at the first diagonal surface, the second diagonal surface and the third diagonal surface.
  • each individual prism structure is processed, for example, by chemical deposition, coating or electroplating to set the light-splitting film at the location where the light-splitting film needs to be set. Then, each prism structure is butted and glued to form an integrated structure.
  • Option 2 Optical components (coupling into grating to reflect 0-level light and deflecting light out)
  • Figure 22 is a schematic diagram of an optical assembly 200 provided by an embodiment of the present application.
  • the optical component 200 provided by the present application includes an optical machine 20 and an optical waveguide 10A.
  • the optical machine 20 includes a light-emitting unit 21, a light combining unit 22 and an optical imaging unit 23.
  • the optical waveguide 10A is located in the optical machine 20.
  • the optical waveguide 10A includes a waveguide substrate 19, a coupling grating 11, a relay grating 13 and an coupling grating 12.
  • the coupling grating 11 , the relay grating 13 and the coupling grating 12 are all formed on the surface of the waveguide substrate 19 .
  • the coupling grating 11 is facing the optical machine 20 Shiny surface.
  • the light emitted by the light emitting unit 21 of the optical engine 20 is synthesized by the light combining unit 22 and the mixed beam passes through the optical imaging unit 23 and then is projected onto the coupling grating 11 .
  • the light coupling grating 11 is formed on the coupling surface 11S on the waveguide substrate 19 .
  • the coupling surface 11S is substantially planar, and the coupling surface 11S is nearly perpendicular to the optical axis 23P of the optical machine 20 .
  • the coupling surface 11S can be perpendicular to the optical axis 23P of the optical machine 20, or the angle between the coupling surface 11S and the optical axis 23P of the optical machine 20 is within a smaller range, for example, the coupling surface 11S and the optical machine 20
  • the angle between the optical axes 23P of the optical machine 20 is less than one-half of the field of view of the optical machine 20, that is,
  • the light emitted from the first position B1 in the light-emitting unit 21 is modulated into parallel light in a certain direction after passing through the light combining unit 22 and the optical imaging unit 23.
  • the coupling grating 11 20 %-30% of the energy enters the waveguide substrate 19.
  • the light entering the waveguide substrate 19 will be totally reflected in the waveguide substrate 19, and then pass through the relay grating 13, transmitted to the coupling grating 12, and coupled out through the coupling grating 12 to
  • the human eye forms a virtual image B11 (as shown in Figure 23).
  • the light focused on the second position B2 will return along the original path, be coupled into the grating 11 for modulation, and finally enter the waveguide substrate 19. After total reflection in the waveguide substrate 19, it is coupled out to the human eye by the coupling grating 12, forming a ghost image B21 (as shown in Figure 23).
  • FIG. 23 is a schematic diagram of the ghost image problem caused by the optical assembly shown in FIG. 22 .
  • it can be analyzed based on the optical path that the ghost image B21 and the original image (virtual image B11) will have a 180° rotational symmetry relationship.
  • the optical waveguide includes a waveguide base and a coupling grating.
  • the waveguide base includes a slope. The slope is located at a position where the coupling grating and the waveguide base are combined or at a position where the coupling grating and the coupling grating are combined.
  • the coupling grating is used to receive the light of the optical machine, the inclined surface faces the optical machine, the optical machine has an optical axis, and the direction perpendicular to the optical axis is In the first direction, the angle between the inclined plane and the first direction is greater than or equal to half of the field of view of the optical machine, so that the field of view of the optical machine reflected by the coupling grating
  • the edge light of the corner can deflect from the optical machine, so that the optical component can obtain better image display efficiency and solve the problem of ghost images.
  • Figures 24A and 24B are schematic diagrams of optical components provided by an embodiment of the present application.
  • Figures 24A and 24B respectively show schematic diagrams of the light emitted from positions B1 and B2 on the light-emitting unit being reflected by the coupling grating.
  • the optical component includes an optical machine 20 and an optical waveguide 10A.
  • the optical waveguide 10A includes a waveguide substrate 19 , a coupling grating 11 , a relay grating 13 and an outcoupling grating 12 .
  • the coupling grating 11 , the relay grating 13 and the coupling grating 12 are formed on the surface of the waveguide substrate 19 .
  • the waveguide substrate 19 is a high-refractive waveguide substrate material, and the refractive index of the waveguide substrate 19 can be greater than or equal to 1.6.
  • the material of the waveguide substrate 19 is TiO2, silicon nitride, gallium nitride, high-folding resin material, etc.
  • the optical signal can be transmitted by total reflection in the waveguide substrate 19 .
  • the waveguide substrate 19 has a flat structure as a whole. Most of the outer surface area of the waveguide substrate 19 is the main plane 190.
  • the main plane 190 is flat, and the main plane 190 is perpendicular to the optical axis 23P of the optical machine 20 or is sandwiched between them. The angle is in a smaller range, which can be understood as allowing a smaller included angle between the main plane 190 and the optical axis 23P caused by factors such as manufacturing process errors or assembly tolerances.
  • the relay grating 13 and the decoupling grating 12 are formed on the main plane 190 . As shown in FIGS.
  • the surface of the waveguide substrate 19 on the side facing the optical engine 20 and perpendicular to the optical axis 23P and on the side facing away from the optical engine 20 and perpendicular to the optical axis 23P are both main planes 190 .
  • the waveguide substrate 19 includes a slope 191 located at a position where the coupling grating 11 and the waveguide substrate 19 are combined.
  • the waveguide base 19 is an integrally formed structure
  • the slope 191 is a structure formed by removing part of the material from the waveguide base 19 .
  • the slope 191 is formed on the surface of the waveguide substrate 19 facing the optical engine 20 . This solution defines a specific bevel formation method.
  • the manufacturing process of the bevel 191 is as follows: first provide a flat waveguide substrate, both surfaces of the waveguide substrate are planar, and remove a part of the material near the edge of one of the planes by cutting. , form a bevel, and then perform surface treatment on the bevel, such as polishing.
  • the two main planes 190 of the waveguide substrate 19 are respectively the first main plane and the second main plane.
  • the first main plane and the second main plane are arranged oppositely, and the first main plane and the second main plane are arranged oppositely.
  • the second main planes may be perpendicular to the optical axis 23P of the optical machine 20 .
  • One end of the slope 191 is connected to the first main plane of the waveguide substrate 19
  • the other end of the slope 191 is connected to the second main plane of the waveguide substrate 19 .
  • a sharp angle is formed between the slope 191 and the main plane 190 away from the optical machine 20 structure.
  • the planes 190 can also be connected through side planes or arc surfaces.
  • the coupling grating 11 is formed on the inclined surface 191 .
  • the coupling grating 11 is a diffraction grating, such as a Surface Relief Grating manufactured using photolithography technology, or a Volumetric Holographic Grating manufactured based on holographic interference technology.
  • the coupling grating 11 is used to receive the mixed light beam transmitted by the optical engine 20 and modulate the mixed light beam. At the position of the coupling grating 11, part of the light beam enters the waveguide substrate 19 through the coupling grating, and part of the light beam is reflected by the coupling grating.
  • FIG. 24A schematically expresses the FOV edge light of the optical engine 20 , that is, the light incident on the coupling grating 11 at the B1 position of the light-emitting unit 21 , and the schematic diagram of the reflected light after being reflected by the coupling grating 11 .
  • the light emitted from the first position B1 of the light-emitting unit 21 of the optical engine 20 passes through the light combining unit 22 and then enters the optical imaging unit 23. After being modulated by the optical imaging unit 23, it forms the incident angle of the field of view of the optical engine 20.
  • the edge light is projected onto the coupling grating 11.
  • the coupling grating 11 modulates the incident light, and 20%-30% of the energy enters the waveguide substrate 19.
  • the light entering the waveguide substrate 19 will be totally reflected in the waveguide substrate 19, and then transmitted to the coupling grating through the relay grating 13. 12, and is coupled out to the human eye through the coupling grating 12 to form a virtual image.
  • 40% of the energy of the parallel light projected by the optical engine 20 onto the coupling grating 11 is directly reflected (the light represented by the dotted line), that is, reflection level 0.
  • the angle between the incident edge ray of the field of view of the optical machine 20 incident on the coupling grating 11 and the optical axis 23P is the first angle ⁇ 1.
  • the reflected light ray passing through the coupling grating 11 (referred to as the coupled grating reflected light) and the optical axis 23P is a second angle ⁇ 2, and the second angle ⁇ 2 is greater than the first angle ⁇ 1. Since the second angle ⁇ 2 is greater than the first angle ⁇ 1 , it can be ensured that the reflected light does not enter the optical engine 20 .
  • manufacturing tolerances or assembly errors can easily lead to the angle between the coupled grating reflected light and the optical axis and edge incident light. and the optical axis.
  • one embodiment of the present application can improve the manufacturing yield by defining a difference of at least 0.1° between the second angle ⁇ 2 and the first angle ⁇ 1.
  • the second angle ⁇ 2 between the reflected light of the coupling grating and the optical axis 23P is greater than the angle between the incident edge light and the optical axis 23P of the field of view of the optical machine 20 incident on the coupling grating 11 angle (first angle ⁇ 1), in this way, it can be ensured that the light reflected by the coupling grating 11 is deflected out of the optical machine 20.
  • the "polarized light machine 20" can be understood as the light reflected by the coupled grating will not enter the effective optical system of the optical machine 20. area, the light reflected by the coupled grating is outside the optical effective area of the optical engine 20 and will not be reflected back to the light-emitting unit 21 of the optical engine 20 . Therefore, the optical component provided by this embodiment does not have the phenomenon that the reflected light coupled out of the grating 11 enters the optical engine 20 and is reflected again to form a ghost image.
  • the reflected light coupled into the grating 11 deviates from the optical machine. Since the incident edge ray is the light at the extreme position of the optical machine FOV, combined with The coupling grating 11 is set on the slope 191.
  • the relationship between the slope 191 and the optical axis 23P is not perpendicular, but forms a certain angle. This design can ensure that the light emitted from other positions on the light-emitting unit 21 is deflected light. Machine.
  • FIG. 24B schematically expresses the reflection path of the light emitted at the second position B2 on the light-emitting unit 21 after being coupled into the grating 11 .
  • the light emitted from the second position B2 on the light-emitting unit 21 passes through the light combining unit 22 and then enters the optical imaging unit 23. After being modulated by the optical imaging unit 23, it is projected on the coupling grating 11.
  • the position of the grating 11 is reflected, and the angle between the reflected light and the optical axis 23P is the third angle ⁇ 3.
  • the third angle ⁇ 3 is greater than the second angle ⁇ 2. Therefore, the light emitted at the second position B2 will deviate from the optical engine 20 after being reflected by the coupling grating 11 .
  • Figures 25A and 25B are schematic diagrams of optical components provided by an embodiment of the present application.
  • Figures 25A and 25B respectively show schematic diagrams of the light emitted from positions B1 and B2 on the light-emitting unit being reflected by the coupling grating.
  • the waveguide substrate 19 includes a main plane 190 , the inclined plane 191 is inclined relative to the main plane 190 , and the coupling grating 11 is formed on the main plane 190 .
  • the inclined surface 191 is located between the coupling grating 11 and the optical engine 20 , and the incident edge light of the viewing angle of the optical engine 20 enters the light through the inclined surface 191 .
  • the waveguide 10A is incident on the coupling grating 11 .
  • the incident edge light When the incident edge light is projected on the inclined surface 191, it will be reflected, forming the inclined surface reflected light as shown in Figure 25A.
  • the energy of this inclined surface reflected light is weak, for example, less than 10% of the energy incident on the coupling grating position.
  • the inclined surface reflected light Even if it enters the optical machine, it will not affect the imaging effect and cannot produce ghost images. Therefore, this application does not consider whether the light reflected from the inclined surface will enter the optical machine.
  • the incident edge light shown in Figure 25A enters the optical waveguide 10A at the position of the inclined surface 191 and is projected onto the coupling grating 11.
  • a reflection level 0 will be formed at the position of the coupling grating 11, that is, the coupling grating reflects the light.
  • the design of this application enables the light reflected by the coupling grating to be deflected out of the optical machine 20 . specific and In other words, the coupling grating 11 will reflect part of the light, and the reflected part of the light will directly emit the optical waveguide 10A, forming the coupling grating reflected light.
  • the inclined surface 191 is inclined relative to the main plane 190 where the coupling grating 11 is located, the light that enters the optical waveguide 10A from the inclined surface 191 and is projected on the coupling grating 11 is refracted at the position of the inclined surface 191, which ensures that the coupling grating 11
  • the reflected light of the coupling grating that is positionally reflected will deflect out of the light engine 20.
  • the "deviated light engine 20" can be understood to mean that the reflected light will not enter the optical effective area of the optical engine.
  • the reflected light is located outside the effective light area of the optical engine. That is, It will not be reflected back to the light-emitting unit of the light machine. Therefore, the optical component provided by this embodiment does not have the phenomenon that the reflected light coupled out of the grating 11 enters the optical engine 20 and is reflected again to form a ghost image.
  • the coupling grating of the polarizing light machine can be formed to reflect the light.
  • the angle between the incident edge ray projected on the inclined plane 191 and the field of view of the optical engine 20 and the optical axis 23P of the optical engine 20 is the first angle ⁇ 1
  • the coupling grating reflected at the coupling grating 11 reflects
  • the angle between the light and the optical axis 23P of the optical engine 20 is a second angle ⁇ 2, and the second angle ⁇ 2 is greater than the second angle ⁇ 1.
  • the embodiment shown in FIG. 25A limits the second angle ⁇ 2 to be greater than the first angle ⁇ 1, so that the light emitted from the first position B1 of the light-emitting unit 21, that is, the incident edge light, deviates from the reflected light coupled into the grating 11.
  • the coupling grating 11 since the incident edge light is the light at the extreme position of the FOV of the optical machine, the coupling grating 11 is set on the side of the inclined plane 191 away from the optical machine.
  • the inclined plane 191 and the optical axis 23P are not in a vertical relationship, but form a At a certain angle, the incident edge light is refracted.
  • Such a design can ensure that the light emitted from other positions on the light-emitting unit 21 is deflected out of the light machine after being reflected by the coupling grating 11 .
  • FIG. 25B schematically expresses the reflection path of the light emitted at the second position B2 on the light-emitting unit 21 after being coupled into the grating 11 .
  • the light emitted from the second position B2 on the light-emitting unit 21 passes through the light combining unit 22 and then enters the optical imaging unit 23. After being modulated by the optical imaging unit 23, it is projected on the inclined surface 191 and is refracted by the inclined surface 191. Then it enters the optical waveguide 10A, and is projected on the coupling grating 11, and is reflected at the position of the coupling grating 11, and the angle between the reflected light and the optical axis 23P is the third angle ⁇ 3.
  • the third angle ⁇ 3 is greater than the second angle ⁇ 2. Therefore, the light emitted at the second position B2 will deviate from the optical engine 20 after being reflected by the coupling grating 11 .
  • the manufacturing process of the coupling grating 11 is It is easy to produce and has advantages in both design and process steps.
  • the coupling grating 11 is fabricated on the slope 191.
  • the optical path between the coupling grating 11 and the optical engine 20 is better than that shown in Figures 25A and 25B.
  • the implementation shown is simple and easy to control the light transmission efficiency.
  • Figures 26A and 26B are schematic diagrams of optical components provided by an embodiment of the present application.
  • Figures 26A and 26B respectively show schematic diagrams of the light emitted from positions B1 and B2 on the light-emitting unit being reflected by the coupling grating.
  • the optical component includes an optical machine 20 and an optical waveguide 10A.
  • the optical waveguide 10A includes a waveguide substrate 19 , a coupling grating 11 , a relay grating 13 and an outcoupling grating 12 .
  • the waveguide substrate 19 includes a waveguide main structure 192 and an additional structure 193.
  • the additional structure 193 is fixed to a surface of the waveguide main structure 192 facing the optical machine 20.
  • a slope 191 is formed on the additional structure 192.
  • the inclined surface 191 is located on the surface of the additional structure 193 facing away from the main waveguide structure 192 .
  • the waveguide main structure 192 is a flat-plate structure. As shown in FIG.
  • the waveguide main structure 192 has a rectangular cross-section.
  • This solution adds an additional structure 193 to the waveguide base and forms a slope through the additional structure.
  • This solution has the advantage of protecting the structural integrity of the waveguide base.
  • the structural integrity of the waveguide base is conducive to ensuring the life of the waveguide base. Without removing part of the structure,
  • the waveguide substrate has better strength and stability, and the optical waveguide with good structural stability has relatively stable optical transmission efficiency.
  • the additional structure 193 may be a triangular body-shaped structure. As shown in FIG. 26A , the additional structure 193 has a triangular cross-section.
  • the material of the waveguide main structure 192 and the additional structure 193 are the same.
  • the refractive index of the main waveguide structure 192 and the refractive index of the additional structure 193 are the same.
  • the material of the waveguide main structure 192 and the additional structure 193 are both high-fold substrate materials.
  • the high-fold substrate materials can be but are not limited to: TiO2, silicon nitride, gallium nitride, high-fold resin materials, etc.
  • the materials of the waveguide main structure 192 and the additional structure 193 are designed to be the same, which can ensure that the light incident on the waveguide base 19 is transmitted in the additional structure 193 and the waveguide main structure 192 in a consistent manner, thereby avoiding light deflection due to different refractive indexes.
  • the diffraction efficiency is affected or the required incident light angle cannot be obtained. Therefore, this application can ensure the optical performance of the optical waveguide 10A by limiting the refractive index and material of the additional structure 193 to be consistent with the waveguide substrate 19 .
  • the refractive index defined in this application is the same, and the "same" can be understood to mean exactly the same, with a small tolerance, or to be approximately the same, as long as the angle of the incident light is within the design requirements.
  • the waveguide main structure 192 and the additional structure 193 may be bonded together by optical glue.
  • the optical glue has a high refractive index.
  • the refractive index of the optical glue is the same as the refractive index of the waveguide main structure and the additional structure.
  • the surface where the waveguide main structure 192 and the additional structure 193 are combined can be polished and then bonded and fixed.
  • the additional structure 193 The position of the bevel 191 needs to be polished to improve the light transmittance.
  • the waveguide main structure 192 and the additional structure 193 can also be integrated into one through intermolecular bonding.
  • the molecular bonding method avoids the introduction of other media such as glue, which can better ensure that the waveguide main structure 192 and The refractive index of the additional structure 193 is matched.
  • the coupling grating 11 is formed on the slope 191.
  • the light incident from the coupling grating 11 passes through the additional structure 193 and then enters the waveguide main structure 192.
  • the angle between the reflected light ray coupled into the grating 11 (that is, the reflected light ray coupled into the grating 11) and the optical axis 23P is the second angle ⁇ 2.
  • the angle between the incident edge ray of the field angle and the optical axis 23P is a first angle ⁇ 1, and the second angle ⁇ 2 is greater than the first angle ⁇ 1.
  • This solution limits the specific position of the coupling grating in the solution of arranging an additional structure combined with the waveguide substrate.
  • the coupling grating is arranged on a slope. This makes the optical path of the incident light coupled into the grating simple and the energy of the incident light easy to control, which is beneficial to improving the light efficiency.
  • the working principle of the embodiment shown in FIG. 26A is the same as the working principle of the embodiment shown in FIG. 24A.
  • the embodiment shown in Figure 26A limits the light emitted from the first position B1 of the light-emitting unit 21, that is, the incident edge ray, and the reflected light coupled into the grating 11 deviates from the optical machine, because this incident edge ray is the extreme position of the optical machine FOV.
  • the light combined with the coupling grating 11 is set on the inclined plane 191.
  • the inclined plane 191 and the optical axis 23P are not perpendicular to each other, but form a certain angle. This design can ensure that the light emitted from other positions on the light-emitting unit 21 is even. It's a partial light machine.
  • FIG. 26B schematically expresses the reflection path of the light emitted at the second position B2 on the light-emitting unit 21 after being coupled into the grating 11 .
  • the light emitted from the second position B2 on the light-emitting unit 21 passes through the light combining unit 22 and then enters the optical imaging unit 23. After being modulated by the optical imaging unit 23, it is projected on the coupling grating 11.
  • the position of the grating 11 is reflected, and the angle between the reflected light and the optical axis 23P is the third angle ⁇ 3.
  • the third angle ⁇ 3 is greater than the second angle ⁇ 2. Therefore, the light emitted at the second position B2 is reflected by the coupling grating 11 (ie, the coupling grating reflected light) will deviate from the optical engine 20.
  • Figures 27A and 27B are schematic diagrams of optical components provided by an embodiment of the present application.
  • Figures 27A and 27B respectively show schematic diagrams of the light emitted from positions B1 and B2 on the light-emitting unit being reflected by the coupling grating.
  • the difference between this embodiment and the embodiment shown in FIG. 26A is that the installation position of the coupling grating 11 is different.
  • the waveguide main structure 192 includes a main plane 190, the inclined surface 191 on the additional structure 193 is inclined relative to the main plane 190, and the coupling grating 11 is formed on the main plane 190.
  • the inclined surface 191 is located between the coupling grating 11 and the optical engine 20 .
  • the edge rays of the field of view of the optical engine 20 enter the additional structure 193 and the waveguide conductor structure 192 through the bevel 191 and are incident on the coupling grating 11 and are reflected by the coupling grating 11
  • the edge light at the field of view of the optical machine 20 is reflection level 0, that is, the light is coupled into the grating and reflected.
  • the light reflected by the coupling-in grating directly exits the optical waveguide 10A and is deflected out of the optical machine 20.
  • the "deviated light machine 20" can be understood to mean that the reflected light will not enter the optical effective area of the optical machine.
  • the light reflected by the coupling-in grating is located in the optical machine 20.
  • the optical component provided by this embodiment does not have the phenomenon that the reflected light coupled out of the grating 11 enters the optical engine 20 and is reflected again to form a ghost image.
  • the angle between the coupling grating reflected light reflected by the coupling grating 11 and the optical axis 23P is the second angle ⁇ 2
  • the edge light of the field of view of the optical machine 20 is incident on
  • the angle between the incident edge ray on the inclined surface 191 and the optical axis 23P is a first angle ⁇ 1
  • the second angle ⁇ 2 is greater than the first angle ⁇ 1.
  • the incident edge light When the incident edge light is projected onto the inclined surface 191, it will be reflected at the position of the inclined surface 191, which is called inclined surface reflected light.
  • the energy of the light reflected by the inclined surface is weak, for example, less than 10% of the energy incident on the coupling grating position. Even if the light reflected by the inclined surface enters the optical machine, it will not affect the imaging effect and cannot produce ghost images. Therefore, the inclined surface reflection will not be considered in this application. Whether light will enter the optical machine.
  • the embodiment shown in FIG. 27A is similar in principle to the embodiment shown in FIG. 25A.
  • the light emitted from the first position B1 of the light-emitting unit 21, that is, the incident edge light is coupled into the grating 11 and the reflected light deviates from the optical machine. Due to this incident edge
  • the light is the light at the extreme position of the optical machine FOV.
  • the coupling grating 11 is set on the side of the inclined plane 191 facing away from the optical machine.
  • the inclined plane 191 and the optical axis 23P are not perpendicular to each other, but form a certain angle. Light is refracted. Such a design can ensure that the light emitted from other positions on the light-emitting unit 21 is deflected out of the light machine after being reflected by the coupling grating 11 .
  • FIG. 27B schematically expresses the reflection path of the light emitted at the second position B2 on the light-emitting unit 21 after being coupled into the grating 11 .
  • the light emitted from the second position B2 on the light-emitting unit 21 passes through the light combining unit 22 and then enters the optical imaging unit 23. After being modulated by the optical imaging unit 23, it is projected on the inclined surface 191 and is refracted by the inclined surface 191. Then it enters the optical waveguide 10A, and is projected on the coupling grating 11, and is reflected at the position of the coupling grating 11, and the angle between the reflected light and the optical axis 23P is the third angle ⁇ 3.
  • the third angle ⁇ 3 is greater than the second angle ⁇ 2. Therefore, the light emitted at the second position B2 will deviate from the optical engine 20 after being reflected by the coupling grating 11 .
  • the positional relationship between the additional structure 193 and the waveguide main structure 192 may have Many different forms.
  • Figure 28 schematically describes the positional relationship between the three additional structures 193 and the waveguide main structure 192.
  • the inclination direction of the inclined surface 191 on the additional structure 93 relative to the waveguide main structure 192 is adjustable.
  • the inclined direction of the inclined plane 191 can correspond to different definitions of the field of view angle of the optical machine.
  • the field of view angle of the optical machine can be a horizontal plane field of view angle and a vertical plane field of view angle.
  • the direction perpendicular to the extension direction of the optical axis 23P of the optical machine 20 is the reference direction. Therefore, in the optical assembly provided by this application, the angle between the slope on the waveguide substrate and this reference direction is greater than or equal to the angle of the optical machine. : One-half of the horizontal field of view angle or one-half of the vertical field of view angle.
  • the optical axis of the optical machine is the central axis of the effective optical area of the optical machine. It can be understood that the optical machine can be a non-off-axis optical system, and the central axis of the optical effective area is the optical axis. It provides convenience for the design of optical machines. In other embodiments, the optical machine may also be an off-axis optical system.
  • Figure 29 schematically depicts the parameters of the optomechanical field of view.
  • the definition and calculation rules of the field of view (FOV) of the optical machine are as follows, as shown in Figure 29.
  • the square area with the diagonal line AB is the entire image display area, and the position of point O is the human eye. position, then the FOV size corresponding to the square area observed by the human eye is 2*tan(AC/S).
  • the horizontal FOV and vertical FOV are 24 degrees and 18 degrees respectively.
  • the direction perpendicular to the optical axis 23P is the reference direction, and the angle between the inclined surface 191 and the reference direction is greater than or equal to 12 degrees.
  • the optical machine edge FOV corresponds to point E in FIG. 29 .
  • the angle between the slope 191 and the reference direction is greater than or equal to ⁇ 2
  • the refractive index of the medium around the waveguide base 19 is n1
  • the refractive index of the waveguide base 19 is n2
  • the angle between the inclined plane 191 and the reference direction only needs to be greater than or equal to this value.
  • Option 3 Coupling grating architecture including one-dimensional grating and two-dimensional grating
  • the present application provides an optical waveguide.
  • the optical waveguide can be a diffractive optical waveguide.
  • the diffractive optical waveguide has the advantages of being light, thin, compact, and high-brightness. This type of optical waveguide is used in near-eye display devices and can promote near-eye display.
  • the display device has two advantages: lightweight and easy to wear. For optical waveguides, during the design process, how to improve the efficiency of light transmission, ensure the uniformity of image light, and reduce the difficulty of processing and manufacturing are the directions of industry research and development.
  • Figure 30 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • the optical waveguide 10A includes a waveguide substrate 19 and a coupling grating 11 and a coupling grating 12 formed on the waveguide substrate 19.
  • the coupling grating 11 is arranged opposite to the optical machine and is used to receive light.
  • the light beam transmitted by the machine is coupled into the waveguide base 19.
  • the light beam propagates through total reflection in the waveguide base 19, and is coupled out through the coupling grating 12, so that the human eye can see the image.
  • the coupling grating 12 mainly has two functions: one is to expand the pupil so that light can cover a larger area; the other is to couple out the light so that the light enters the human eye.
  • the coupling grating 12 is a two-dimensional grating structure.
  • the coupling grating 12 has two periodic directions.
  • a beam of light can be coupled out of the grating. 12 is divided into 8 propagation directions (as shown in Figure 31, which is a schematic diagram of a two-dimensional grating dividing light into 8 propagation directions). It is understandable that light in the eight propagation directions will not be coupled out, and light in some directions is wasted because it cannot be coupled out.
  • FIG. 32 is a diagram of the outcoupled light efficiency of the optical waveguide shown in FIG. 31 . Figure 32 shows the efficiency diagram of coupled light.
  • the darker areas are areas with high coupling efficiency, and the lighter areas are areas with lower coupling efficiency.
  • the coupling efficiency of the middle area on the left side of the square area is the highest, the light coupling efficiency of the middle area of the square gradually becomes weaker from left to right, and the light coupling efficiency of the four corners of the square is the lowest.
  • the entire area of the coupling grating 12 in the optical waveguide 10A shown in Figure 30 is a two-dimensional grating structure, a beam of light will produce 8 propagation directions after passing through the coupling grating, and a lot of light will not enter the human eye and be directly wasted. fall out, resulting in a waste of energy.
  • the light from different FOV enters the human eye and is modulated by the two-dimensional grating for different times, resulting in different energy entering the human eye, that is, the light uniformity of the image seen by the human eye is inconsistent.
  • the coupling grating includes a first region and a second region.
  • the first region includes a first sub-region and a second region.
  • the second sub-region, the grating type in the first sub-region and the second sub-region are both one-dimensional gratings
  • the grating type in the second region is a two-dimensional grating
  • the center of the second region and The connection line between the centers of the coupling grating is called a central axis
  • the first sub-region and the second sub-region are distributed on both sides of the central axis.
  • the waveguide substrate 19 of the optical waveguide 10A may be a wafer or imprinting glue with a higher refractive index.
  • the coupling-in grating 11 and the coupling-out grating 12 are formed on the surface of the waveguide substrate 19 .
  • the coupling grating 11 is located in the light incident area of the optical waveguide 10A
  • the coupling grating 12 is located in the light output area of the optical waveguide 10A.
  • the coupling grating 12 includes a first region 121 and a second region 122 .
  • the coupling-in grating 11 and the coupling-out grating 12 are arranged along the first direction X.
  • the first area 121 is located on the light incident side of the second area 122 , and the first area 121 is located between the coupling grating 11 and the second area 122 .
  • the first area 121 includes a first sub-area 1211 and a second sub-area 1212.
  • the first sub-area 1211 and the second sub-area 1212 are arranged along the second direction Y.
  • the center of the first sub-area 1211 and the The connecting direction between the centers of the two sub-regions 1212 is the second direction Y, and the second direction Y intersects the first direction are perpendicular or nearly perpendicular to each other.
  • the grating type in the first sub-region 1211 and the second sub-region 1212 is a one-dimensional grating
  • the grating type in the second region 122 is a two-dimensional grating.
  • the one-dimensional grating is schematically represented by a pattern of mutually parallel lines in the first sub-region 1211 and the second sub-region 1212
  • the two-dimensional grating is represented by a grid pattern in the second region 122 .
  • Figure 33 only schematically shows the one-dimensional grating and the two-dimensional grating, and does not limit the specific structure, specific position distribution, specific size and area of the one-dimensional grating and the two-dimensional grating.
  • the connection line between the center of the coupling grating 11 and the center of the second region 122 is called the central axis 12L.
  • the extending direction of the central axis 12L is the first direction X.
  • the first sub-region 1211 and the second sub-region 1212 are distributed on both sides of the central axis 12L. Specifically, the first sub-region 1211 is located on one side of the central axis 12L, and the second sub-region 1212 is located in the middle. The other side of axis 12L.
  • the central axis 12L is also the central axis of the coupling grating 12, and the coupling grating 12 can be a symmetrical distribution structure with the central axis 12L as the center of symmetry.
  • the first sub-region 1211 and the second sub-region 1212 are distributed mirror-symmetrically around the central axis 12L. This solution constrains the relationship between the first sub-region and the second sub-region and the central axis, and uses a mirror-symmetric design to make the energy of the light coupled out of the second region of the grating more balanced.
  • FIG. 34 takes a beam of light as an example to show that the coupling grating 12 can improve the efficiency of light propagation and improve the uniformity of light through the one-dimensional grating in the first area.
  • the first beam 01 entering the optical waveguide from the coupling grating 11 is transmitted to the first region 121 of the coupling grating 12, since the grating type in the first region 121 is a one-dimensional grating, in the first region 121 , the first beam 01 is divided into two parts (i.e., the first beam 02 and the second beam 03), the first beam 02 propagates downward and enters the second area 122, and the second beam 03 continues to propagate forward and enters the second area 122.
  • the second partial beam 03 entering the second area 122 will also propagate downward under the action of the two-dimensional grating in the second area 122, forming a covering of the second area 122 and the third partial beam 04.
  • the first area 121 is set as a one-dimensional grating.
  • the first area 121 has a pupil expansion, which can also constrain the direction of light propagation and improve energy utilization.
  • the light modulated by the first area 121 has only two directions, and the light in these two directions All can enter the second area 122.
  • the coupling grating 12 provided in this application can allow a larger area of light to enter the human eye, or in other words, the human eye can observe images over a larger area.
  • the light beam is in the coupling grating. Since the coupling gratings are two-dimensional gratings, the light beam will be divided into eight directions of light, and most of the eight directions of light cannot be coupled out, forming waste. It is obvious that in the optical waveguide 10A provided by the embodiment shown in Figure 33, when the first beam 01 propagates to the first area 121, since the grating type in the first area 121 is a one-dimensional grating, the first beam 01 is divided into Light in two directions, namely the first partial beam 02 and the second partial beam 03 , eventually enters the second region 122 . Therefore, the embodiment shown in FIG. 33 can improve the efficiency of light propagation.
  • FIG. 33 refers to Figure 33.
  • the dotted lines with arrows in Figure 33 represent the first gate line direction F1 and the second gate line direction F2.
  • the extending direction of the gate lines of the one-dimensional grating in the first sub-region 1211 is The first gate line direction F1
  • the extending direction of the gate lines of the one-dimensional grating in the second sub-region 1212 is the second gate line direction F2.
  • the two-dimensional grating in the second area 122 includes first grating lines 1221 and second grating lines 1222 arranged to intersect.
  • the extending direction of the first gate line 1221 is the first gate line direction F1, and the extending direction of the second gate line 1222 is the second gate line direction F2; or, the extending direction of the first gate line 1221
  • the extending direction of the second gate line 1222 is substantially the same as the first gate line direction F1.
  • the extending direction of the second gate line 1222 is substantially the same as the second gate line direction F2. It can be understood that the extension direction of the first grid line 1221 and the first grid line direction F1 can be within a small allowable included angle range. When the included angle is 0, the two are in the same direction or in the same direction. Parallel relationship.
  • the extension direction of the first raster line 1221 is substantially the same as the first raster line direction F1
  • the extension direction of the second raster line 1222 is substantially the same as the second raster line direction F2 so that the image information transmitted by the optical waveguide is It is authentic, does not produce image distortion, and ensures the image display effect.
  • the angle between the first grid line direction F1 and the second grid line direction F2 is 60 degrees.
  • the angle between the first grating line direction F1 and the second grating line direction F2 is 60 degrees, which can constrain the propagation direction of the light so that the propagation direction of the light matches the grating line direction of the two-dimensional grating in the second area 122 , which can ensure that more light is coupled out and achieve higher light efficiency.
  • the distribution period of the one-dimensional grating in the first sub-region 1211 is the same as the distribution period of the first grating line 1221
  • the distribution period of the one-dimensional grating in the second sub-region 1212 is the same as that of the first grating line 1221.
  • the distribution periods of the second gate lines 1222 are the same.
  • the distribution period of the one-dimensional gratings in the first sub-region 1211 and the second sub-region 1212 may both be 300 nm.
  • This scheme constrains the first sub-region
  • the period of the one-dimensional grating in is the same as the period of the first grating line in the second region, and the period of the one-dimensional grating in the second sub-region is the same as the period of the second grating line in the second region, which can be guaranteed
  • the coupled image will not be distorted, and the image will not produce distortion or other undesirable phenomena, ensuring the display effect of the image.
  • the direction and period of the grating lines of the two-dimensional grating in the second area 122 change, the first sub-area 1211 and the second sub-area 1212 of the first area 121
  • the direction and period of the grating lines of the one-dimensional grating also need to be changed accordingly.
  • the contact between the first sub-region 1211 and the second sub-region 1212 can also be understood as there is no gap between the first sub-region 1211 and the second sub-region 1212, or the first sub-region 1211 and the second sub-region 1212 are in contact with each other. There are no other structural features between the area 1211 and the second sub-area 1212 that do not belong to the first area. There is contact between the first sub-region 1211 and the second region 122, and between the second sub-region 1212 and the second region 122.
  • the areas of the first sub-region 1211 and the second sub-region 1212 are equal. In other embodiments, the areas of the first sub-region 1211 and the second sub-region 1212 may not be equal. The areas of the first sub-region 1211 and the second sub-region 1212 may not be equal. The specific size and shape of the first sub-area 1211 and the second sub-area 1212 are adjusted according to the needs. In the embodiment shown in FIG. 33 , the areas of the first sub-region 1211 and the second sub-region 1212 are equal. In other embodiments, the areas of the first sub-region 1211 and the second sub-region 1212 may not be equal. The areas of the first sub-region 1211 and the second sub-region 1212 may not be equal. The specific size and shape of the first sub-area 1211 and the second sub-area 1212 are adjusted according to the needs. In the embodiment shown in FIG.
  • the first area 121 and the second area 122 have the same size, and in the first direction, the size of the second area 122 is larger than the size of the first area 121 . It can also be understood that the area of the second region 122 is larger than the area of the first region 121 .
  • the first area 121 and the second area 122 may not be in contact, that is, there is a separation area between the first area 121 and the second area 122 , and there is no grating structure in this separation area.
  • a first spacing area 1213 is formed between the first sub-region 1211 and the second area 122, and there is no grating structure in the first spacing area 1213.
  • a second spacing area 1214 is formed between the second sub-region 1212 and the second area 122, and there is no grating structure in the second spacing area 1214.
  • the first spacing area 1213 and the second spacing area 1214 are connected.
  • the arrangement of the first spacing area 1213 and the second spacing area 1214 is conducive to ensuring that the manufacturing yield and efficiency are improved during the process of manufacturing the coupling grating 12 . Since the first area 121 is a one-dimensional grating, and the part of the second area 122 adjacent to the first area is a two-dimensional grating, if the first area 121 and the second area 122 are in contact, no separation area is provided. During the process, the boundaries of each part need to be accurately controlled to avoid the edges of the first region 121 and the edges of the second region 122 from overlapping. Therefore, this solution can save manufacturing costs through the arrangement of the first spacing area 1213 and the second spacing area 1214.
  • the extension size of the first spacing area 1213 in the first direction X is less than or equal to 4 mm.
  • the extension size of the second spacing area 1214 in the first direction X is less than or equal to 4 mm.
  • a third spacing region 1215 is formed between the first sub-region 1211 and the second sub-region 1212 , and there is no grating structure in the third spacing region 1215 . Since the grating types in the first sub-region 1211 and the second sub-region 1212 are both one-dimensional gratings, if the first sub-region 1211 and the second sub-region 1212 are in contact, it is necessary to accurately control the first sub-region 1211 and the second sub-region 1212 during the production process. The boundary of the second sub-area 1212 ensures that the two boundaries do not overlap. If the boundaries of the two overlap, a two-dimensional grating will be formed in the overlapping part.
  • the two-dimensional grating will divide the light into eight different directions, resulting in a waste of light and loss of energy. Therefore, this solution can save production costs and ensure production yield by separating the first sub-region 1211 and the second sub-region 1212 so that their edges do not contact.
  • the size of the third spacing area 1215 extending in the second direction Y is less than or equal to the maximum radial size of the coupling grating.
  • the third spacing area As long as the third spacing area is reserved, it can be ensured that the one-dimensional grating in the two areas is easier to produce, saving production and R&D costs.
  • This solution constrains the relationship between the third spacing area and the maximum radial size of the coupling grating, so that the light transmitted by the coupling grating to the third spacing area can still pass through the one-dimensional gratings in the first sub-region and the second sub-region. The structure is transmitted to the second area, which can avoid more waste of light energy.
  • the center positions of the coupling grating 11 and the coupling grating 12 are directly opposite, and the coupling grating 11 and the coupling grating 12 are symmetrically distributed in the second direction Y with the central axis 12L as the center. It can be understood that in different application scenarios, the positions of the coupling grating 11 and the coupling grating 12 will be adjusted. When the coupling grating 11 moves relative to the coupling grating 12, the central axis 12L changes accordingly.
  • the optical waveguide 10A provided in this application is used in a near-eye display device, that is, AR glasses. In the near-eye display device, the optical waveguide 10A needs to be combined with the lens. It can also be understood that the optical waveguide 10A needs to be installed on the lens. Or integrated with the lens. In this application scenario, the coupling grating 12 is usually located near the edge or corner of the lens.
  • the in-coupling grating 11 faces the first sub-region 1211 on the out-coupling grating 12 .
  • An included angle is formed between the extending direction of the central axis 12L and the first direction X.
  • the dividing line between the first sub-region 1211 and the second sub-region 1212 in the first region 121 is located on the central axis 12L.
  • the first sub-region 1211 and the second sub-region 1212 in the first region 121 have different outline shapes and areas. Not the same either.
  • the connecting direction between the center positions in the first direction X is the second direction Y.
  • An included angle of less than 90 degrees is formed between the first direction Y and the central axis 12L.
  • the specific structural form of the first sub-region 1211 and the second sub-region 1212 in the first region 121 changes.
  • the first sub-region 1211 and the second sub-region 1211 The area 1212 can still constrain the propagation direction of the light beam and improve the light propagation efficiency. Its optical principle is the same as that shown in Figure 34.
  • a first spacing area 1213 is provided between the first sub-area 1211 and the second area 122.
  • a second spacing area 1214 is provided between the sub-region 1212 and the second area 122, and a third spacing area 1215 is provided between the first sub-region 1211 and the second sub-region 1212.
  • the specific size areas of the first sub-region 1211 and the second sub-region 1212 have also been adjusted accordingly.
  • the first sub-region 1211 protrudes from the top edge of the second region 122 in the second direction Y, and the second sub-region 1212 is The bottom edge of the second region 122 is retracted in the second direction Y.
  • the coupling grating 12 may include only one or two of the first spacing area 1213, the second spacing area 1214, and the third spacing area 1215.
  • the benefits brought by the setting of each spacing area are the same as the corresponding parts of the embodiment shown in FIG. 36 and FIG. 37 , and will not be described again.
  • the second region 122 in the coupling grating 12 includes N two-dimensional regions 1222 and N-1 one-dimensional regions 1221 , N ⁇ 2.
  • the N-1 one-dimensional regions 1221 are respectively located between two adjacent two-dimensional regions 1222, and one of the two-dimensional regions 1222 is adjacent to or adjacent to the first region 121.
  • the fact that the two-dimensional area 1222 is adjacent to the first area 121 can be understood as: the two-dimensional area 1222 and the first area 121 are in contact with each other, and there is no gap between them.
  • the fact that the two-dimensional area 1222 is adjacent to the first area 121 can be understood as: there is no contact between the two-dimensional area 1222 and the second area 121, and there is a space between them.
  • the grating type in the one-dimensional area 1221 is a one-dimensional grating
  • the grating type in the two-dimensional area 1222 is a two-dimensional grating.
  • this application by arranging a two-dimensional grating and a one-dimensional grating in the second area 122, and arranging the one-dimensional grating in the middle of the two-dimensional grating, it is beneficial to regulate the intensity of the coupled light and make the entire picture more uniform.
  • the light intensity of a part adjacent to the first area 121 is greater than the light intensity of a part far away from the first area 121 .
  • the one-dimensional region 1221 is arranged between adjacent two-dimensional regions 1222.
  • the one-dimensional grating in the one-dimensional region 1221 can weaken the light intensity at the position of the one-dimensional region 1221.
  • the one-dimensional grating in the one-dimensional region 1221 The one-dimensional grating can constrain the direction of light propagation, allowing the light to be concentrated in the two-dimensional area on the light exit side of the one-dimensional area (the right side of the one-dimensional area shown in Figure 40). This can enhance the light intensity in the two-dimensional area. Therefore, overall, the intensity uniformity of the coupled light in the second area 122 can be ensured.
  • the second area 122 includes three two-dimensional areas 1222 and two one-dimensional areas 1221 .
  • Each one-dimensional region 1221 includes a third sub-region 12211 and a fourth sub-region 12212.
  • the third sub-region 12211 and the fourth sub-region 12212 are arranged along the second direction Y and distributed on the central axis 12L. both sides.
  • the raster line direction of some gratings in the two-dimensional area 1222 is the same as the raster line direction of the grating in the third sub-area 12211.
  • the raster line direction of some gratings in the two-dimensional area 1222 is the same as the raster line direction of the fourth sub-area 12211.
  • the grating lines in sub-region 12212 have the same direction.
  • the extension direction of the central axis 12L is the first direction X, and the coupling grating 11 is opposite to the center position of the coupling grating 12 .
  • the third sub-region 12211 and the fourth sub-region 12212 may have the same area, and are mirror-image distributed on both sides of the central axis 12L.
  • the coupling grating 11 is opposite to the corner position of the coupling grating 12, the extending direction of the central axis 12L is inclined relative to the first direction X, and an included angle is formed between the central axis 12L and the first direction X.
  • the third sub-region 12211 and the fourth sub-region 12212 may have different areas.
  • the top and bottom surfaces of the waveguide substrate 19 in the optical waveguide 10A provided by the present application are provided with coupling gratings 12.
  • the specific structure of the coupling grating 12 can be any one of Figures 33 to 41.
  • the first region 121 of the coupling grating 12 located on the top surface of the waveguide substrate 19 is directly opposite to the first region 121 of the coupling grating 12 located on the bottom surface of the waveguide substrate 19 .
  • the second area 122 of the outcoupling grating 12 is directly opposite to the second area 122 of the outcoupling grating 12 located on the bottom surface of the waveguide substrate 19 .
  • decoupling gratings are provided on both the top and bottom surfaces of the waveguide substrate 19, and the decoupling gratings constrain the light propagation direction through the first area, which can more effectively improve the light propagation efficiency and light uniformity.
  • the coupling grating 12 of the optical waveguide 10A can also be provided on only one side of the waveguide substrate 19.
  • the coupling grating 12 is not provided on the bottom surface of the waveguide substrate 19, only the waveguide substrate.
  • the top surface of 19 is provided with a coupling grating.
  • the coupling grating 12 described in any embodiment of Figures 33 to 41 is provided on the top surface of the waveguide substrate 19, and other types of coupling grating 12' are provided on the bottom surface of the waveguide substrate 19. , other types of coupling gratings 12' are directly opposite to the second region 122 in the coupling grating 12 described in any embodiment of FIGS. 33 to 41 .
  • the near-eye display device (such as AR glasses) provided by this application allows the user to simultaneously observe the surrounding real mirror image and virtual information through an optical fusion device.
  • the near-eye display device performs this function through a waveguide structure.
  • this application has a The optical waveguide 10A provided by the embodiment includes a coupling grating 11 and a coupling grating 12.
  • the coupling grating 11 is used to inject the light of each field of view generated by the optical machine 20 into the optical waveguide 10A, and propagates in the optical waveguide 10A, and is coupled by the coupling grating.
  • the output grating 12 couples the light out of the optical waveguide 10A, so that the light enters the human eye and is imaged, thereby generating virtual image information.
  • the optical waveguide 10A in the near-eye display device allows the surrounding scene to pass through the optical waveguide and enter the human eye for imaging, thereby enabling the user to observe real scenes and virtual image information at the same time.
  • VAC convergence conflict
  • the mechanism of the convergence conflict (VAC) phenomenon is that optical waveguides can generally only produce a virtual image position.
  • the human eye must focus on the virtual image to see a clear image.
  • the vertical distance between the human eye and the virtual image position is the virtual image.
  • Distance from L1 At the same time, in order to produce stereoscopic vision, a visual gap is generated through binocular parallax, and the visual gap L2 is related to the displayed content.
  • L1 ⁇ L2 VAC problems will occur, affecting the user experience.
  • Figure 43 is a schematic diagram of three different configurations of the virtual image distance and the visual distance difference corresponding to the virtual image on the virtual image plane generated by the optical waveguide provided by the present application.
  • the virtual image distance L1 and the visual distance L2 are equal.
  • the human eye's perceived distance is consistent with the human eye's focusing distance, and the user will not feel uncomfortable.
  • picture b (middle picture) of Figure 43 the virtual image where the virtual image is located is far away from L1. The human eye needs to relax and focus to the distance to see the virtual image clearly.
  • the generated visual difference L2 (composed by the two virtual images)
  • the opening angle ⁇ of the human eye (determined by the opening angle ⁇ of the human eye) is relatively close, and the opening angle ⁇ of the virtual image is large.
  • the user will feel that the virtual image is close, and VAC problems will occur at this time, making the user feel uncomfortable.
  • the virtual image distance L1 where the virtual image is located is relatively close, and the human eye needs to focus close to see the virtual image clearly.
  • the generated visual distance L2 is far away, and the virtual image is The angle ⁇ is small, which will also conflict with the user's usual eye habits, causing VAC problems.
  • the light emitted from the optical engine 20 enters the optical waveguide 10A through the coupling grating 11, and propagates through total reflection in the optical waveguide 10A, and is turned after passing through the relay grating 13, and It is emitted to the human eye through the coupling grating 12 .
  • the coupling grating 12 is a continuously extending large-area grating structure, the coupled light is a wide aperture beam, and the coupled light 12 is coupled out to the pupil of the human eye. will fill the entire pupil, and the coupled light forms an eye movement space (EyeBox) EB of a certain size at the position of the human eye.
  • the distance between the pupil and the coupling grating is the exit pupil distance (EyeRelief) LER, as shown in Figure 44.
  • the outer contour of the coupling grating 12 is rectangular, and the eye movement space ER projected by the coupling light is also rectangular.
  • the area of the eye movement space ER is much larger than that of the eye, and the pupil of the human eye is filled with the coupling light.
  • the light emitted from the coupling grating enters the human eye, is imaged on the retina, and the light beam fills the pupil. Since the pupil size of the human eye is generally 2-4mm in a bright environment, when the human eye focuses correctly, a clear image will be formed on the retina. For out-of-focus objects, they cannot be focused on the retina through the pupil, but will become diffuse. spot.
  • Figure 45 is the optical path principle diagram of the VAC phenomenon caused by wide beam imaging. Refer to Figure 45. When the human eye focuses on the depth A, A will be correctly focused on the retina through the pupil of the human eye to form the image A'.
  • the distance The object point at depth B that is closer to the human eye is imaged at the back of the retina B' after passing through the pupil of the human eye. At this time, it is a diffuse spot of a certain size on the retina, and the human eye cannot clearly distinguish the object point at depth B. imaging.
  • the light coupled out by the coupling grating is an array of thin beams. It can be understood that the size of each beam is small, and the number of beams entering the pupil can be only one beam, so that the beam The pupil will not be filled. In one embodiment, the size range of the light beam is: less than or equal to 1.5 mm.
  • Figure 46 is a schematic diagram of the optical path for thin beam imaging to solve the VAC problem. When a thin beam enters the human eye for imaging, the depth of field will become very large, allowing the user to observe virtual images with different parallaxes no matter where the user focuses.
  • the virtual image can be clearly seen without caring about where the virtual image distance of the virtual image is actually located, thus solving the problem that the virtual image distance of the optical waveguide is a fixed value and eliminating the VAC problem.
  • the thin beam emitted from the object point A passes through the human eye and is focused on the retina, forming a clear object point A’.
  • the thin beam emitted by the object point at depth B which is closer to the human eye, will not fill the pupil when it passes through the pupil.
  • After passing through the human eye it will form a diffuse spot on the retina due to defocus.
  • due to the thin beam it will not fill the pupil.
  • the aperture of the beam is very small, and the size of the dispersion spot formed is also very small, so the human eye can still clearly see the image at B.
  • Figure 47 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • the optical waveguide 10A includes a waveguide substrate 19 , a coupling grating 11 , a relay grating 13 and an coupling grating 12 .
  • the relay grating 13 is located between the coupling grating 11 and the coupling grating 12 .
  • the coupling grating 11 receives the light projected by the optical machine, couples the light into the waveguide substrate 19 and performs total reflection propagation in the waveguide substrate 19 .
  • the light propagates to the relay grating 13
  • the light is projected to the position of the coupling grating 12 through the turning of the relay grating 13.
  • the coupling grating 12 couples out the light and projects it to the human eye to form a virtual image.
  • the coupling grating 12 includes a plurality of sub-gratings 125, and the plurality of sub-gratings 125 are arranged at intervals from each other.
  • the plurality of sub-gratings 125 are arranged in an array of multiple rows and columns.
  • the array arrangement has the same row spacing and the same column spacing, that is, the spacing between any two adjacent sub-gratings 125 is equal.
  • the array arrangement structure composed of multiple sub-gratings 125 includes 60 sub-gratings 125 , arranged in 6 rows and 10 columns.
  • each sub-grating 15 is the same, for example, the outer contour of all the sub-gratings 125 is circular.
  • the coupling grating 12 may include sub-gratings 125 of different sizes, or the coupling grating 12 may include sub-gratings 125 of different shapes.
  • the outer contour shape of the sub-grating 125 may be but is not limited to: circle, triangle, Square or hexagon.
  • the overall outer contour of the coupling grating 12 shown in FIG. 47 is rectangular. It can be understood that in other embodiments, the coupling grating 12 with different shapes of outer contours can be designed according to specific design requirements.
  • the coupling grating 12 is no longer a continuous grating overall structure, but is divided into multiple sub-gratings 125, each sub-grating 125. It has the function of coupling out light and projecting the light to the human eye, but the light projected by each sub-grating 125 is a thin beam. When the thin beam is projected to the human eye, due to its small size, it cannot fill the pupil. The size of the thin beam can is 0.5mm-1.5mm.
  • FIG. 48 is a schematic diagram of the coupling grating of the optical waveguide shown in FIG. 47 .
  • the maximum radial dimension D of each sub-grating 125 is less than or equal to 1.5 mm.
  • the spacing between two adjacent sub-gratings 125 is L, 3mm ⁇ L ⁇ 5mm.
  • the spacing between two adjacent sub-gratings 125 refers to the distance between the centers of the two adjacent sub-gratings 125. distance.
  • one of the sub-gratings 125 is a first sub-grating 1251, and there are intervals between the first sub-grating 1251 and other sub-gratings 125 adjacent to the first sub-grating 1251. In the area 125G, in FIG.
  • the area outside the sub-grating 125 (that is, the areas in the coupling grating 12 that do not belong to the sub-grating are all isolated areas) are all isolated areas 125G. There is no grating structure in the isolation area 125G, and the isolation area 125G cannot couple out the light beam.
  • the maximum radial dimension D of the first sub-grating 1251 is less than or equal to 1.5 mm. It can be understood that, in one implementation, all the sub-gratings 125 may be the first sub-gratings 1251 of the same size.
  • the size and shape of other sub-gratings may be different from the size and shape of the first sub-grating 1251, but the maximum radial dimension D of the other sub-gratings is less than or equal to 1.5 mm. . To ensure that all sub-gratings 125 project thin beams.
  • the radial size of the first sub-grating 1251 is D, 0.5mm ⁇ D ⁇ 1mm.
  • This plan limits the radial size of the first sub-grating 1251 to be greater than or equal to 0.5mm, which can ensure that the first sub-grating 1251 can have the function of coupling out the grating, that is, it can couple the light in the optical waveguide to the human eye.
  • This plan limits The radial size of the first sub-grating 1251 is less than or equal to 1 mm, which can ensure that the light projected by the first sub-grating 1251 is a thin beam. Even if the pupil size becomes smaller due to environmental factors, the first sub-grating 1251 projects to the pupil. The beam is still a thin beam and cannot fill the pupil.
  • the radial size range of each of the sub-gratings 125 is smaller. Specifically: 0.25mm ⁇ D ⁇ 0.75mm.
  • the radial size range of each of the sub-gratings 125 is larger. Specifically: 0.75mm ⁇ D ⁇ 1.5mm.
  • the size range of the spacing between two adjacent sub-gratings 125 is: 3.5mm ⁇ L ⁇ 4.5mm.
  • the range of spacing between two adjacent sub-gratings 125 defined in this embodiment can meet various application environments and different application scenarios, and it is easier to ensure that the light coupled out by the sub-gratings 125 is a thin beam.
  • the sub-grating 125 is a two-dimensional grating structure.
  • Each of the sub-gratings 125 includes grating microstructures 1252 arranged in a preset period.
  • the preset period may be 200-500 nm.
  • the specific shape of the grating microstructure 1252 may be but is not limited to: hexagon, parallelogram, triangle, trapezoid, etc.
  • the sub-grating 125 can couple out the light in the optical waveguide and project it to the human eye.
  • the area between the two sub-gratings 125 is the separation area 125G.
  • the size of 125G can ensure that the light beam coupled out by the sub-grating 125 is a thin beam, and can ensure that only one beam of light enters the human eye pupil for imaging at the same time. Combined with the imaging principle shown in Figure 46, it can be determined that this solution can solve the problem. VAC issue.
  • the size of the separation area 125G can be understood as: the difference between the spacing between two adjacent sub-gratings 125 and the diameter of one sub-grating.
  • the difference between the embodiment shown in FIG. 49B and the embodiment shown in FIG. 49A is that the grating type in the sub-grating 125 is different.
  • the sub-grating 125 is a one-dimensional grating structure.
  • the sub-grating 125 has periodically arranged grating microstructures 1252 .
  • Figure 50 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • the difference between the embodiment shown in FIG. 50 and the embodiment shown in FIG. 47 lies in the arrangement of the sub-gratings 125 in the coupling structure 12 .
  • a plurality of sub-gratings 125 are arranged in multiple rows.
  • the arrangement direction of the sub-gratings 125 in each row is the first direction Y is perpendicular to the first direction 125G.
  • the sub-gratings 15 in the coupling grating 12 are arranged in 7 rows, the 1st, 3rd, 5th, and 7th rows are odd-numbered rows, and the 2nd, 4th, and 6th rows are even-numbered rows.
  • the odd-numbered rows are opposite to the separation area 125G between two adjacent sub-gratings 125 of the even-numbered rows. Any sub-grating 125 in the odd-numbered rows and two adjacent sub-gratings 125 in the even-numbered rows form an equilateral triangle.
  • the sub-gratings 125 are arranged in a plurality of regular hexagonal structures. This solution is also called a honeycomb array arrangement solution.
  • the honeycomb array arrangement scheme provided by this embodiment has the following advantages: this scheme can ensure that each position in the eye movement space is The relative distance of the thin beams is The spacing of each thin beam in the orthogonal array arrangement scheme is slightly larger in the hypotenuse direction than in the horizontal and vertical directions.
  • this solution when the human eye moves within the eye movement space, such as when the eye rotates or the glasses slide, different thin light beams entering the pupil of the human eye will change. Due to the honeycomb-like arrangement of each The relative distance of the fine grating is constant. Since the human eye is displaced relative to the eye movement space, the energy of the beam entering the human eye can be guaranteed to be equal. Therefore, the changes in the image will be flatter, which can improve the user experience of near-eye display devices.
  • multiple sub-gratings 125 may be disposed coplanarly, that is, multiple sub-gratings 125 may be disposed on the same surface of the waveguide substrate.
  • Figure 51 is an optical waveguide 10A provided in one embodiment.
  • Grating structures are provided on both front and back sides of the waveguide substrate 19, that is, the coupling grating 11, the relay The grating 13 and the coupling grating 12 are arranged in pairs on the front and back sides of the waveguide substrate 19 .
  • FIG. 51 simultaneously draws the grating structure on both front and back sides of the waveguide substrate 19 , FIG.
  • FIG. 52 only draws the grating structure on the front side of the waveguide substrate 19
  • FIG. 53 only draws the grating structure on the back side of the waveguide substrate 19 .
  • each sub-grating 125 of the coupling grating 12 located on the front side of the waveguide substrate 19 and each sub-grating 125 of the coupling grating 12 located on the reverse side of the waveguide substrate 19 are arranged in one-to-one correspondence. Therefore, FIG.
  • the front and back sub-gratings 125 shown in 51 are in an overlapping relationship.
  • one of the two adjacent sub-gratings 125 is located on the front side of the waveguide substrate 19 of the optical waveguide, and the other of the two adjacent sub-gratings 125 is located on the On the reverse side of the waveguide substrate 19, the center of the sub-grating 125 located on the front side of the waveguide substrate 19 is the center - 125C1, and the center of the sub-grating 125 located on the reverse side of the waveguide substrate is perpendicular to the front side of the waveguide substrate.
  • the projection is center two 125C2, and the distance L between the two adjacent sub-gratings 125 is the distance between center one 125C1 and center two 125C2.
  • the sub-gratings 125 in the coupling grating 12 are distributed on different surfaces of the waveguide substrate 19.
  • the sub-gratings 125 marked with cross-section lines in the circle are located on the front side of the waveguide substrate 19.
  • the sub-grating 125 with a blank space in the circle (not shown as a cross-section line) is located on the opposite side of the waveguide substrate 19 .
  • the relay grating and/or the outcoupling grating may adopt a zone design or a gradient design.
  • the grating height in the area of the relay grating close to the coupling grating is shorter, and the grating height in the area far away from the coupling grating is shorter. High; the area where the coupling grating is close to the relay grating has a shorter grating height, and the area away from the relay grating has a higher height.
  • a coupling grating 11, a relay grating 13 and a coupling grating 12 are provided on the surface of the waveguide substrate 19.
  • the top surface of the relay grating 13 (the surface away from the waveguide substrate 19) extends in an inclined plane.
  • the left side is close to the coupling grating 11, and the right side is close to the coupling grating 12.
  • the grating height on the left side of the relay grating is lower, and the grating height on the right side is higher. From the left side to the right side of the relay grating 13, the relay grating 13 The grating height can show a gradual growth trend.
  • the coupling grating 12 includes a first sub-grating region 126 and a second sub-grating region 127.
  • the first sub-grating region 126 is closer to the relay grating 12 than the second sub-grating region 127 is to the relay.
  • the coupling grating 12 includes a first edge 1261 and a second edge 1271.
  • the first edge 1261 is the edge of the coupling grating 12 adjacent to the relay grating 13.
  • the second edge 1271 is the coupling grating. 12 Far from the edge of the relay grating 13, from the first edge 1261 to the second edge 1271, the height of the sub-gratings in the coupling grating 12 gradually increases.
  • the design of the coupling grating partition or gradient provided by this solution can adjust the diffraction efficiency and improve the light uniformity.
  • the grating microstructures in each sub-grating have the same height or have the same shape.
  • coupling gratings, coupling gratings and relay gratings can have different grating morphologies.
  • FIG. 58 is a schematic diagram of the control architecture between the control unit and the outcoupling grating in the near-eye display device shown in FIG. 57 .
  • the near-eye display device 1000 provided by this application includes an optical engine 20, an optical waveguide 10A, a control unit 181, a pupil detection component 182, and a grating adjustment component 183.
  • the optical engine 20 is used to project light to the optical waveguide 10A.
  • the optical waveguide 10A includes a coupling grating 11 , a relay grating 13 and a coupling grating 12 .
  • the coupling grating 11 receives the light projected by the optical engine 20 and couples the light into the optical waveguide 10A.
  • the outcoupling grating 12 includes a plurality of sub-gratings 125 arranged in an array. It can be understood that the arrangement of the plurality of sub-gratings 125 may be, but is not limited to, an array arrangement of multiple rows and columns (similar to the arrangement of multiple sub-gratings in the embodiment shown in FIG. 47 ), a honeycomb array arrangement (similar to the arrangement of FIG. 47 ). The arrangement of multiple sub-gratings in the embodiment shown in 50).
  • FIG. 59 shows a specific structure of the coupling grating 12 in the embodiment shown in FIGS. 57 and 58 .
  • the maximum radial dimension D of each sub-grating 125 is less than or equal to 1.5mm, and the spacing between two adjacent sub-gratings is L', D ⁇ L' ⁇ 4mm, L' refers to adjacent The distance between the centers of the two sub-gratings 125.
  • the array of sub-gratings 125 set up in this solution is arranged in a dense manner, and the distance between adjacent sub-gratings 125 can be zero. That is to say, the sub-gratings can be arranged in such a way that they are in contact with each other one by one.
  • Gaps can also be set between the sub-gratings 125 .
  • This solution uses an arrangement scheme in which the distance between two adjacent sub-gratings is L', and is combined with the grating adjustment member 182 to realize opening some of the sub-gratings, so that in the sub-grating array in the working state, the adjacent sub-gratings in the working state are The range of the distance L between the centers of the grating is: 3mm ⁇ L ⁇ 5mm.
  • the pupil detection parts 182 are used to detect the size of the pupils.
  • the number of the pupil detection parts 182 is two. two, respectively disposed on the left lens 10L and the right lens 10R of the near-eye display device 1000.
  • the pupil detection component 182 is disposed adjacent to the coupling grating 12, so that the pupil detection component 182 can more accurately detect the size of the pupil.
  • the control unit 181 is configured to receive signals from the pupil detection component 182 .
  • the control unit 181 is also used to drive the grating adjustment member 183 .
  • the grating adjustment member 183 includes a row controller 1831 and a column controller 1832.
  • the row controller 1831 is used to control the switch of the area corresponding to each row of sub-gratings 125
  • the column controller 1832 is used to control the switch of the area corresponding to each column of sub-gratings 125.
  • the grating adjustment member 183 is used to control the opening or closing of some rows or columns of the coupling grating 12, so that some sub-gratings enter the working state, and can ensure the smoothness between adjacent sub-gratings in the working state.
  • the range of the spacing L is: 3mm ⁇ L ⁇ 5mm, so as to realize the sub-grating to emit thin beams, and the number of thin beams entering the pupil is one, thereby solving the VAC problem.
  • Figure 60 schematically expresses the distribution of sub-gratings 125 in a working state.
  • the structure of the coupling grating 12 shown in Figure 60 is: the sub-gratings of some rows and some columns are closed through the row controller and column controller of the grating adjustment member. The closed sub-gratings of some rows and some columns are not shown in the figure.
  • the displayed sub-gratings 125 are all in the open state, that is, the sub-gratings 125 are in the working state.
  • the spacing between adjacent sub-gratings 125 in each row is L
  • the spacing between adjacent sub-gratings 125 in each column is L.
  • the working sub-grating can respond to pupils of different sizes. For example, when the pupil size changes, the grating adjustment member can be used to adjust the working state of the sub-grating. spacing to improve image display efficiency. This solution does not need to switch the virtual image distance according to the actual content, and can reduce system power consumption.
  • the optical waveguide provided by the specific embodiment of the present application injects light from each field of view generated by the optical machine into the optical waveguide through a coupling grating.
  • the light will propagate through total reflection in the optical waveguide, and will be coupled out of the optical waveguide by the coupling grating and enter the human body. Eye imaging.
  • the optical waveguide allows the surrounding scene to pass through the optical waveguide and enter the human eye for imaging, so that the user can observe the real scene and virtual information (image information) at the same time.
  • the optical waveguide provided by this application can be applied to vehicle HUD, head-mounted augmented reality glasses, etc.
  • the coupling grating couples light into the optical waveguide through the diffraction effect, and the coupling out grating can also couple the light out of the optical waveguide through the diffraction effect. Therefore, how to improve the coupling efficiency and coupling efficiency to improve the optical utilization of optical waveguides is a research direction in the industry.
  • the diffraction efficiency and optical utilization can be improved by changing the refractive index of the grating.
  • the volume holographic grating obtains a higher average refractive index and refractive index modulation by adjusting the formula of the holographic material, and obtains a Volume holographic gratings with different refractive index distributions, but by changing the holographic material to obtain the ideal average refractive index and refractive index modulation, the ideal effect cannot be achieved.
  • the main reason is that it is limited by the characteristics of the holographic material. Specifically, holographic materials are usually composed of polymer monomers and inert polymers.
  • the present application provides an optical waveguide by designing the grating structure of the optical waveguide.
  • the structure of one period of the grating structure is designed as layers with different refractive indexes stacked along the vector direction of the grating structure. Structure, through the design of different refractive indexes in one cycle of the grating structure, the refractive index of the grating structure is changed to improve the diffraction efficiency and optical utilization of the optical waveguide.
  • the optical waveguide 10A includes a waveguide substrate 19 and a grating structure 14 formed on the waveguide substrate 19 .
  • Figure 61 schematically expresses a specific positional relationship and structural components between the waveguide substrate 19 and the grating structure 14, and does not represent the specific structural form of the optical waveguide 10A.
  • the grating structure 14 protrudes from the surface of the waveguide substrate 19 , and the waveguide substrate 19 is in the shape of a flat plate.
  • the surface of the waveguide substrate 19 may be in the shape of a plane.
  • the grating structure 14 may be a coupling grating, a coupling grating or a relay grating.
  • the light is coupled into the optical waveguide 10A through the grating structure 14 and can propagate through total reflection in the waveguide substrate 19 .
  • the waveguide substrate 19 is a material with a relatively high refractive index.
  • the refractive index of the waveguide substrate 19 is between 1.38-2.6.
  • the material of the waveguide substrate 19 may include metal oxide.
  • the material of the waveguide substrate 19 can be any one of MgF2, TiO2, silicon nitride, gallium nitride, and high-folding resin materials.
  • the material of the waveguide substrate 19 can also be a mixed material.
  • the mixed material includes two of the above materials. or a mixture of several.
  • the waveguide substrate 19 may have a single-layer structure, or the waveguide substrate 19 may have a multi-layer structure, such as a composite layer structure composed of different materials for each layer.
  • the grating structure 14 includes a plurality of core structures 141 and a film structure 142.
  • the refractive index of the film structure 142 is different from the refractive index of the core structure 141.
  • the plurality of core structures 141 are sequentially along the vector direction of the grating structure 14. Arranged at intervals, the vector direction of the grating structure in Figure 61 is from left to right. Adjacent core structures 141 are spaced apart by a preset distance, and the membrane structure 142 is disposed within this preset distance range.
  • both sides of the core structure 141 are used to provide film structures 142. As shown in FIG.
  • the core structure 141 arranged on the far left side has a membrane structure 142 on the left side
  • the core structure 141 arranged on the far right side also has a membrane structure 142 on the right side.
  • the membrane structure 142 may only be provided between adjacent core structures 141 , that is, neither the left side of the leftmost core structure 141 nor the right side of the rightmost core structure 142 is provided.
  • the area between adjacent core structures 141 is filled with membrane structures 142 , that is to say, there is no gap (or separation space, no space) in the area between adjacent core structures 141 .
  • Air is present inside the grating structure 14).
  • the grating structure 14 is a continuously extending seamless structure in its vector direction. Such a structural design ensures that there is no air inside the grating structure 14, which is conducive to ensuring the diffraction efficiency of the grating structure 14, and is also conducive to ensuring The grating structure 14 is not affected by environmental factors. For example, dust, moisture, etc. in the air will affect the function and life of the grating structure 14 .
  • FIG 62 is an exploded schematic diagram of part of the grating structure 14 and part of the waveguide substrate 19 in Figure 61.
  • each core structure 141 includes a connection end 1412 , a free end 1413 and a side surface 1411 .
  • the connection end 1412 is connected to the waveguide substrate 19 .
  • the free end 1413 and the connection end 1412 are arranged oppositely in the height direction of the core structure 141 , the height direction of the core structure 141 can be understood as the direction perpendicular to the surface of the waveguide substrate 19 .
  • the side 1411 is connected between the connecting end 1412 and the free end 1412 .
  • the membrane structure 142 includes a membrane main body 1421, a first end 1422 and a second end 1423.
  • the membrane main body 1421 covers the side 1411 of the core structure 141. It can also be understood that the membrane main body 1421 is attached to the side 1411, and the membrane main body 1421 It is in contact with the side 1411 and combined into one body.
  • the first end 1422 and the second end 1423 are respectively located at two ends of the film body 1421 , and the first end 1422 is connected to the waveguide substrate 19 .
  • the end surface of the second end 1423 and the end surface of the free end 1413 of the core structure 141 are coplanar, and the free ends 1411 of all the core structures 141 and the second end 1423 of the film structure 142 together form a grating structure. 14 end face 143.
  • This solution improves diffraction efficiency and optical utilization through the different refractive indexes of the core structure 141 and the film structure 142 of the grating structure 14 .
  • the free end 1411 of the core structure 141 and the second end 1423 of the film structure 142 jointly form the end surface of the grating structure 14, so that the diffraction efficiency of the grating structure 14 is better.
  • the grating structure 14 only has different refractive indexes in its vector direction.
  • the outside of the core structure 141 is not covered by the film structure 142, and the diffraction efficiency of the grating structure 14 can be ensured.
  • the free end of the core structure is covered by a film structure, part of the film structure covering the free end of the core structure will produce a diffraction effect in the height direction of the grating structure.
  • the diffraction in the height direction of the grating structure is different from the vector direction of the grating structure. It will have a negative impact on the diffraction in the vector direction of the grating structure, that is, it will reduce the diffraction efficiency of the grating structure.
  • Figure 63 is a schematic diagram of the end surface 143 of the grating structure 14.
  • the end surface 143 of the grating structure 14 is composed of the end surface of the free end 1413 of the core structure 141 and the end surface of the second end 1423 of the membrane structure 142. Spaced striped structure.
  • the end surface 143 of the grating structure 14 is a planar structure.
  • the membrane structure between adjacent core structures, includes at least three membrane layers, and at least three membrane layers are stacked on the side surfaces of the adjacent core structures. At least three of the film layers have different refractive indexes. Along the vector direction of the grating structure, the refractive index of at least three of the film layers exhibits a sinusoidal distribution gradient trend.
  • the three-layer film structures 142 are the first film layer 142A, the second film layer 142B and the third film layer 142B.
  • Film layer 142C, along the vector direction of the grating structure 14, the first film layer 142A, the second film layer 142B and the third film layer 142C are stacked and arranged between the side surfaces 1411 of adjacent core structures 141.
  • the first film layer 142A and the third film layer 142C are respectively combined on the side 1411 of the adjacent core structure 141.
  • the first film layer 142A and the third film layer 142C are both in direct contact with the side 1411 of the core structure 141.
  • the second film Layer 142B is located between first film layer 142A and third film layer 142C.
  • the first film layer 142A, the second film layer 142B and the third film layer 142C have different refractive indexes.
  • the vector direction of the grating structure 14 can be understood as the direction in which the side surface 1411 of one of the two adjacent core structures 141 faces the side surface 1411 of the other core structure 141 .
  • the refractive index of the first film layer 142A, the refractive index of the second film layer 142B, and the refractive index of the third film layer 142C are sinusoidally distributed, which can be understood as: the changing trend of these three refractive indexes can be from large to small and then to large. changes, or can be changes from small to large and then to small.
  • the refractive index of the first film layer 142A and the refractive index of the third film layer 142C are both greater than the refractive index of the second film layer 142B.
  • the refractive index of the first film layer 142A and the refractive index of the third film layer 142C The refractive index can be equal.
  • the refractive index of the core structure 141 is greater than the refractive index of the first film layer 142A, and the refractive index of the core structure 141 is greater than the refractive index of the third film layer 142C.
  • the refractive index range of each partial structure may be, but is not limited to, the following description: the refractive index range of the core structure 141 may be 1.38-2.6, and the refractive index range of the first film layer 142A and the third film layer 142C may be 1.38-2.6, the refractive index range of the second film layer 142B may be 1.0-2.6.
  • the refractive index of the first film layer 142A and the refractive index of the third film layer 142C are both smaller than the refractive index of the second film layer 142B, and the refractive index of the first film layer 142A and the refractive index of the third film layer 142C
  • the refractive index can be equal.
  • the refractive index of the core structure 141 is smaller than the refractive index of the first film layer 142A, and the refractive index of the core structure 141 is smaller than the refractive index of the third film layer 142C.
  • the refractive index range of each partial structure may be, but is not limited to, the following description: the refractive index range of the core structure 141 may be 1.0-2.6, and the refractive index range of the first film layer 142A and the third film layer 142C may be 1.38-2.6, the refractive index range of the second film layer 142B may be 1.38-2.6.
  • Figure 64 is a schematic diagram comparing the incident angle and diffraction efficiency of a grating structure with a sinusoidal gradient refractive index distribution and a grating structure with a single core structure.
  • the grating structure with a single core structure refers to a grating structure with a single refractive index. Design, in a period of a grating structure, the light has a separate core structure, and the refractive index of the core structure is a fixed value; the grating structure with a sinusoidal gradient refractive index distribution refers to a grating structure that includes the core structure and the film in a period Structure, core structure and film structure have different refractive indexes, resulting in a sinusoidal gradient refractive index distribution.
  • the sinusoidal gradient refractive index grating can have a higher The diffraction efficiency and narrower full width at half maximum can meet the modulation requirements of the incident efficiency at a specific angle, thereby improving the light efficiency of the entire system.
  • the at least three film layers have different thicknesses between adjacent core structures, the film layer with the largest thickness is adjacent to the core structure, and the thickness of the core structure is greater than The thickness of the film layer with the largest thickness.
  • the thickness of the first film layer 142A and the third film layer 142C are the same. They can be made on the side of the core structure 141 through the same coating process. From a production perspective, it has the advantage of being easier to implement and saving man-hours.
  • the thickness of the second film layer 142B is not equal to the thickness of the first film layer 142A. In the specific implementation shown in FIG. 61 , the thickness of the second film layer 142B is smaller than the thickness of the first film layer 142A.
  • the thickness of the core structure 141 may also be smaller than the thickness of the membrane layer in the membrane structure 142 with the smallest thickness, and the membrane layer with the smallest thickness is adjacent to the core structure 141 .
  • the thickness of the second film layer 142B may also be greater than the thickness of the first film layer 142A.
  • Figure 65 is an exploded schematic diagram of part of the grating structure and part of the waveguide substrate of the optical waveguide provided by an embodiment of the present application.
  • the thickness of the core structure 141 is less than the thickness of the first film layer 142A, and the thickness of the core structure 141 is also less than the thickness of the third film layer 142C.
  • the thickness of the first film layer 142A and the thickness of the third film layer 142C can be equal.
  • the second film layer 142B is the layer with the largest thickness in the film structure 142 .
  • the thickness of the film structure 142 covering the side 1411 of the core structure 141 of the grating structure 14 provided by the present application can range from several angstroms to several nanometers.
  • One core structure 141 and the film structure 142 between adjacent core structures 141 constitute a grating period.
  • the number of layers of the membrane structure 142 is a random number layer.
  • the number of layers of the membrane structure 142 is three layers, five layers, seven layers, etc.
  • the layer located in the middle is the middle layer, and the remaining layers can be symmetrically distributed on both sides of the middle layer.
  • the first film layer 142A and the third film layer 142C are symmetrically distributed on both sides of the second film layer 142B.
  • the symmetrical distribution can be understood as symmetry in physical dimensions and symmetry in refractive index.
  • the symmetrical arrangement in physical dimensions is conducive to achieving the advantages of low manufacturing difficulty and easy guarantee of yield.
  • the symmetry in refractive index is conducive to achieving precise control of diffraction efficiency and corresponding incident angle.
  • some of the membrane structures 142 between adjacent core structures 141 have a seamless structure. It can be understood that the space between adjacent core structures 141 is filled by the membrane structure 142 without leaving any gaps.
  • the first film layer 142A and the third film layer 142C are attached to the side surfaces 1411 of the core structure 141 , and the two sides of the second film layer 142B are directly connected to the first film layer 142A and the third film layer 142C respectively. connect.
  • the core structure 141 in the grating structure 14 provided by this application can be a blazed grating or a tilted grating.
  • the refractive index at any position within the core structure 141 is the same.
  • the core structure 141 can be fabricated on the waveguide substrate 19 through a nanoimprinting process or an etching process.
  • the film structure 142 is formed through a coating process. Specifically, a multi-layer film structure can be produced through two or more coating processes. For example, in the embodiment shown in Figure 61, a total of two coating processes are used.
  • the first film layer 142A and the third film layer 142C are produced through the first coating process, and the second film layer 142B is produced through the second coating process.
  • the film structure 142 can also be made by other processes such as atomic layer deposition (ALD), immersion pulling, spin coating, etc.
  • one of the film layers in the film structure 142 is subdivided into a first sub-film and a second sub-film with two different refractive indexes to obtain the target refractive index solution.
  • the target refractive index of the second film layer 142 is N, but directly producing a film layer to obtain an accurate refractive index N film layer is relatively complicated from the process level. Difficult to achieve, factors affecting production may include material selection, film thickness control, etc.
  • the second film layer 142B includes multiple layers of first sub-films 142B1 and multiple layers of second sub-films 142B2 arranged alternately in one-to-one correspondence.
  • the refractive index of the first sub-films 142B1 is N1.
  • the refractive index of the second sub-film 142B2 is N2, and the refractive index of the second film layer 142B composed of the multi-layer first sub-film 142B1 and the multi-layer second sub-film 142B2 is N, N1 ⁇ N ⁇ N2 .
  • the materials of the first sub-film 142B1 and the second sub-film 142B2 may be different, and the thicknesses may also be different.
  • the first sub-film 142B1 and the second sub-film 142B2 can be realized through the same process technology. The production process of these two film layers is simple and easy to control their respective refractive indexes.
  • the refractive index N of the second film layer 142B is finally obtained. Can meet design needs.
  • a core structure 141 is fabricated on the waveguide substrate 19.
  • the core structure 141 protrudes from the surface of the waveguide substrate 19 .
  • the core structure 141 is embedded in the waveguide substrate. 19, that is, the core structure 141 is formed in the concave portion of the waveguide substrate 19.
  • the core structure 141 can be produced on the waveguide substrate 19 through an etching process.
  • the core structure 141 produced through the etching process can have a refractive index range of 1.38-2.6. For example, when the material of the core structure 141 is MgF2.
  • its refractive index can be 1.38, and when the material of the core structure 141 is TiO2, its refractive index can be 2.6.
  • the core structure 141 can also be produced on the waveguide substrate 19 through nanoimprint technology, and the refractive index range of the grating core layer can be approximately 1.4-2.6.
  • the grating period p of the grating structure 14 ranges from 200 to 800 nm
  • the grating height h ranges from 5 to 3000 nm
  • the grating inclination angle ⁇ ranges from approximately 0 to 60°.
  • the period p 400nm
  • the grating height h 600nm
  • the grating tilt angle ⁇ is 55°
  • the width of the grating core layer p0 130nm.
  • Figure 68 shows Figure a, Figure B and Figure C from top to bottom respectively. These three figures are used to express the three steps of completing the production of the grating structure based on the structure shown in Figure 67.
  • a film structure is made using a coating process.
  • a film layer I is formed on the surface of the core structure 141.
  • the film layer I is wrapped around the periphery of the core structure 141.
  • the core structure 141 is covered on the waveguide substrate 19.
  • the thickness p1 of the film layer I may be 70 nm.
  • a gap g is formed between the film layers I.
  • the refractive index of film layer I may be 1.38-2.6.
  • the film layer II is produced.
  • the production method of the film layer II can be the same as the production method of the film layer I, for example, both are produced by a coating process.
  • Film layer II completely covers film layer I, and the gap g formed by film layer I is also filled by film layer II.
  • the film layer I and the film layer II are sequentially stacked above the free end 1413 of the core structure 141 in the height direction of the grating structure.
  • the refractive index of film layer II may be 1.38-2.6.
  • the thickness p2 of the film layer I may be 65 nm.
  • the film structure on the surface of the grating structure is polished smooth through processes such as chemical mechanical polishing (CMP), so that the free end 1413 of the core structure 141 is exposed.
  • CMP chemical mechanical polishing
  • the membrane structure 142 forms a state of incompletely covering the core structure 141.
  • the membrane structure 142 forms the membrane main body and the first and second ends respectively located at both ends of the membrane main body.
  • the second end and the core The free ends 1413 of the structures 141 are coplanar, and the free ends of all the core structures and the second end of the membrane structure together constitute the end surface of the grating structure.
  • a film structure 142 of a gradient refractive index film layer can be plated on the basis of the core structure 141, so as to obtain better angle and wavelength selection characteristics.
  • a high refractive index SRG grating structure ie, core structure 141
  • the refractive index of the SRG grating structure can reach 2.0 or even higher.
  • the refractive index of the SRG grating i.e., the core structure 141) obtained through the etching process can reach a maximum of 2.6.
  • the film structure 142 is formed through a multi-layer coating process, and the refractive index can be gradually changed.
  • the thickness of each coating layer can be from several angstroms to several nanometers.
  • the lowest refractive index can be the air layer, and the maximum ⁇ n can reach 1.6.
  • the core structure 141 has a higher refractive index (for example, the refractive index range is between 1.38-2.6)
  • the change is as shown in the sinusoidal curve in Figure 69: the refractive index gradually becomes lower and then gradually becomes higher.
  • the lowest refractive index of the film structure 142 with gradient refractive index can reach 1.38, and the highest can reach 2.6.
  • the refractive index of the core structure 141 is low (for example, the refractive index range is between 1.38-2.6)
  • the refractive index change between the two core structures 141 is still a sinusoidal distribution, and the refractive index will gradually become higher and then gradually lower. .
  • the benefits of this solution are: it can greatly improve the average refractive index and refractive index modulation of the grating.
  • the average refractive index can reach more than 2.0, and the maximum ⁇ n can reach more than 1.0. It can expand the parameter range and provide suitable parameters for subsequent optical waveguide design. Optimize space.
  • a similar grating structure in which the refractive index change is still sinusoidally distributed can be obtained.
  • the gap 144 may be air, and the refractive index of air is 1.
  • the refractive index of the core structure 141 is greater than the refractive index of the film structure 142, and the refractive index of the film structure 142 is greater than 1.38. In this way, between adjacent core structures 141, the refractive index of the grating structure exhibits a sinusoidal distribution gradient trend.
  • the film structure 142 can be formed on the surface of the core structure 141 through one-time coating.
  • Figure 71 is a three-dimensional schematic diagram of an optical waveguide provided by an embodiment of the present application, schematically expressing the grating structure provided on the surface of the waveguide substrate 19.
  • Figure 71 only schematically represents the coupling grating 11 and the relay grating 13. and the coupling grating 12 are arranged on the waveguide substrate 19, the specific structure and positional relationship of the coupling grating 11, the relay grating 13 and the coupling grating 12, as well as the connection relationship and position between the three and the waveguide substrate 19 are not limited. Relationships and so on.
  • the coupling gratings 12 are distributed on both sides of the waveguide substrate 19, that is, the coupling gratings 12 are provided on both the top and bottom surfaces of the waveguide substrate 19.
  • the coupling gratings 12 are located on the top surface of the waveguide substrate 19.
  • the grating inclination angle of 12 and the grating inclination angle of the coupling grating 12 located on the bottom surface of the waveguide substrate 19 can be different, so that the coupling grating 12 can diffract light in different directions, so that more light is coupled out of the waveguide substrate 19 and the diffraction is improved. efficiency.
  • Figure 72 is a schematic plan view of an optical waveguide provided by an embodiment of the present application.
  • the coupling grating 11 includes a first coupling structure 11A and a second coupling structure 11B.
  • the first coupling structure 11A and the second coupling structure 11B are arranged opposite and respectively Located on the top and bottom surfaces of the waveguide substrate 19, the first coupling structure 11A and the second coupling structure 11B have different Same grating tilt angle.
  • the first coupling structure 11A and the second coupling structure 11B can diffract light in different directions, so that more light is coupled into the waveguide substrate 19 , that is, the first coupling structure 11A and the second coupling structure 11B Combined to achieve high diffraction efficiency over a wide angular range.
  • the first coupling structure 11A and the second coupling structure 11B may have different grating structures and may have different grating parameters such as grating height and grating duty cycle.
  • the first coupling structure 11A and the second coupling structure 11B may adopt the grating structure provided by the embodiment shown in FIG. 61 or FIG. 69 or FIG. 70 .
  • the first coupling structure 11A and the second coupling structure 11B may have different grating core layers (ie, the core structures may be different).
  • the first coupling structure 11A and the second coupling structure 11B may have different film structures (ie, grating coating layers), or may have the same film structure (ie, grating coating layers).
  • the refractive index of the core structure of the first coupling structure 11A may be higher than that of the core structure of the second coupling structure 11B, and the refractive index of the film structure of the first coupling structure 11A may be higher than that of the second coupling structure 11B.
  • the first coupling structure 11A has a core structure with a relatively high refractive index (for example, the refractive index range of the core structure is: 1.9-2.3), and the refractive index of the film structure of the first coupling structure 11A is It is also a high refractive index material.
  • the refractive index range of the film structure is: 2.1-2.6.
  • the first coupling structure 11A can respond to light in the angle range of [-20°, 10°].
  • the second coupling structure 11B adopts a core structure with a lower refractive index (for example, the refractive index range of the core structure is: 1.5-1.9), and the refractive index range of the film structure of the second coupling structure 11B is: 1.7-2.1.
  • the second coupling structure 11B can respond to light in the angle range of [10°, 20°].
  • the first coupling structure 11A and the second coupling structure 11B work simultaneously to achieve response to light in the incident angle range of [-20°, 20°].
  • the coupling grating 12 also has grating structures distributed on the top and bottom surfaces of the waveguide substrate 19.
  • the coupling grating 12 and the coupling grating 11 are both shown in Figure 61 or Figure 72. 69 or the grating structure provided by the embodiment shown in FIG. 70 .
  • the film structure of the outcoupling grating 12 may be different from the film structure of the coupling grating 11 , such as different materials, different refractive indexes, different thicknesses, and so on.
  • a narrower angular bandwidth can be achieved, allowing the optical waveguide to meet specific design requirements.
  • the coupling grating 12 when a grating area only needs to modulate light in a specific direction, that is, it can couple light in a specific direction to the human eye. Therefore, in this case, the angular bandwidth needs to be narrower. Higher diffraction efficiency can be obtained at specific angles.
  • the diffraction efficiency of the middle area of the coupling grating also requires a narrower angular bandwidth. Obtain higher diffraction efficiency.
  • the light on the right side of the coupling grating (the three dotted lines on the right side of the coupling grating 12 schematically express the light projected at the middle position of the coupling grating 12), it is also necessary to have a narrow bandwidth for the light coupling out on the right side of the coupling grating. , to obtain higher diffraction efficiency.
  • Figure 73 is a schematic plan view of an optical waveguide provided by an embodiment of the present application.
  • the relay grating 13 is located between the coupling grating 11 and the coupling grating 12.
  • the relay grating 13 is distributed on the top and bottom surfaces of the waveguide substrate 19.
  • Figure 73 shows the distribution on the top surface. and the relay grating 13 on the bottom surface.
  • the relay grating 13 on the top surface and the relay grating 13 on the bottom surface can have the same structural form, and different grating inclination angles.
  • the relay grating 13 on the top surface and the relay grating 13 on the bottom surface can be composed of It is a symmetrical distribution structure with the central axis 12L as the center.
  • the central axis 12L can be understood as the connection between the center of the coupling grating 11 and the center of the coupling grating 12 .
  • the coupling grating 12 adopts the grating structure provided in the embodiment shown in FIG. 61 or FIG. 69 or FIG. 70 .
  • the coupling-out grating 12 includes a first region 12A and a second region 12B.
  • the first region 12A is closer to the coupling-in grating 11 than the second region 12B.
  • the coupling in the first region 12A is
  • the refractive index difference between the core structure and the film structure of the outcoupling grating 14 is a first value
  • the refractive index difference between the core structure and the film structure of the outcoupling grating 12 in the second region 12B is a second value.
  • the first value is smaller than the second value.
  • a rectangular dotted box is used to represent the first area 12A and the second area 12B.
  • the two rectangular dotted boxes in Figure 73 only schematically express the positional relationship between the first area 12A and the second area 12B, and do not represent the first area 12A and the second area 12B.
  • the first area 12A and the second area 12B may be adjacent, that is, their boundaries may be in contact, or may be referred to as a common boundary.
  • the first area 12A and the second area 12B can also be spaced apart as shown in FIG. 73 , that is, they are separated by other parts of the coupling grating.
  • the relay grating 13 includes a first relay structure 13C and a second relay structure 13D.
  • the first relay structure 13C and the second relay structure 13D are respectively Disposed on the top and bottom surfaces of the waveguide substrate 19, the first relay structure 13C and the second relay structure 13D may have different vector directions. By arranging the first relay structure 13C and the second relay structure 13D with different vector directions, more light can enter the coupling grating 12 and the light utilization rate can be improved.
  • the film structures at different positions have different coating parameters.
  • the coating parameters may be but are not limited to: refractive index, thickness, density, etc.
  • the relay grating 13 adopts the grating provided in the embodiment shown in Figure 61 or Figure 69 or Figure 70. structure.
  • the relay grating 13 includes a third area 13A and a fourth area 13B.
  • the third area 13A is closer to the coupling grating 11 than the fourth area 13B.
  • the center of the third area 13A is
  • the refractive index difference between the core structure and the film structure of the relay grating 13 is a third value, and the difference between the core structure and the film structure of the relay grating 13 in the fourth region 13B
  • the refractive index difference is a fourth value, and the third value is smaller than the fourth value.
  • the coupling grating 12 may also have the structure of the coupling grating 12 shown in FIG. 73 , that is, the coupling grating 12 may also include a first region 12A and a second region 12B.
  • the refractive index difference between the core structure and the film structure of the coupling grating 14 is a first value
  • the refractive index difference between the core structure and the film structure of the coupling grating 12 in the second region 12B is A second value, the first value being less than the second value.
  • the refractive index difference (ie, the fourth value) between the core structure and the film structure in the fourth region 13B of the relay grating 13 is smaller than the first value.
  • the refractive index of the core structure of the relay grating 13 is 2.4, the refractive index of the film structure is 1.9, and the third value (ie, the relay grating in the third area 13A The refractive index difference between the core structure and the film structure of 13) is 0.5.
  • the refractive index of the core structure of the relay grating 13 is 2.4, the refractive index of the film structure is 1.5, and the fourth value (ie, the core structure of the relay grating 13 in the fourth region 13B The refractive index difference between the film structure and the film structure is 0.9.
  • the grating efficiency in the third region 13A is lower than that in the fourth region 13B.
  • the refractive index difference between the core structure and the film structure shows a gradual change trend.
  • the refractive index difference gradually increases, and the refractive index of the relay grating also gradually increases.
  • the optical waveguide needs to continuously improve the diffraction efficiency.
  • the diffraction efficiency needs to have an increasing trend.
  • the present application can increase the diffraction index of the grating by gradually increasing the refractive index difference. The increase in the refractive index also helps to improve the diffraction efficiency of the grating.
  • At least part of the coupling grating 11, the relay grating 13 and the coupling grating 12 in the embodiments shown in Figures 71, 72, 73 and 74 may include those shown in Figure 61 or Figure 69 or Figure 70
  • the optical waveguide provided in one embodiment of the present application is used in near-eye display devices as a medium for light propagation.
  • the optical waveguide includes a waveguide substrate and a coupling grating and a coupling grating formed on the waveguide substrate.
  • the coupling grating transmits the light transmitted by the optical machine. After light is coupled into the optical waveguide, the light needs to be able to propagate through total reflection in the waveguide substrate.
  • the refractive index of the waveguide substrate needs to be increased. Therefore, in order to obtain a better field of view and an image with optical effects, the waveguide substrate needs to have a higher refractive index.
  • the greater the refractive index the greater the weight, but the greater weight will affect the comfort of wearing the near-eye display device.
  • how to reduce weight is an important research and development direction.
  • the present application uses a low refractive index dielectric layer and a grating structure formed on the top and bottom surfaces of the dielectric layer to form a waveguide substrate, and the light is propagated by total reflection through the grating structures formed on the top and bottom surfaces of the dielectric layer.
  • the grating structure described here is not a coupling grating, a coupling grating, or a relay grating. Its function is only to realize the total reflection propagation of light in the waveguide substrate.
  • the low refractive index dielectric layer has the advantage of being lightweight. The overall weight of the waveguide substrate formed by the low refractive index dielectric layer and the grating structures formed on the top and bottom surfaces of the dielectric layer can also be controlled within a smaller range.
  • Solution 6 Volume holographic grating constitutes total reflection propagation
  • FIG. 75 is a schematic diagram of an optical waveguide provided by an embodiment of the present application.
  • an optical waveguide provided in one embodiment includes a coupling region 10Ai, a coupling region 10Ao, and a light propagation region 10Ap.
  • the coupling region 10Ai is provided with a coupling grating 11, which is used to receive the incident light emitted by the optical engine 20. It can be understood that the light emitted by the optical engine 20 is incident on the coupling grating 11 to form incident light. The incident light enters the optical waveguide 10A and is totally reflected in the light propagation area 10Ap.
  • the coupling grating 12 is used to couple out light, so that the light is projected to the human eye to form a virtual image.
  • the waveguide base of the optical waveguide 10A is a low refractive index material.
  • the optical waveguide 10A includes a dielectric layer 194 and a first grating layer located on both sides of the dielectric layer 194. 19A and the second grating layer 19B. Specifically, the first grating layer 19A and the second grating layer 19B are formed on the top and bottom surfaces of the dielectric layer 194 respectively.
  • the total reflection propagation of light in the light propagation area 10Ap is achieved through the first grating layer 19A and the second grating layer 19B distributed on both sides of the dielectric layer 194.
  • the dielectric layer 194 alone cannot achieve total reflection propagation of light. of.
  • the refractive index of the dielectric layer 194 is less than or equal to 1.5. By constraining the range of the refractive index of the dielectric layer 194, this solution can ensure that the dielectric layer 194 has the advantage of low density and light weight, which is conducive to the lightweight design of the optical waveguide 10A.
  • This solution defines at least one of the first grating layer and the second grating layer to have different periods, so that at least one of the first grating layer and the second grating layer can transmit ambient light, and also It can completely reflect the light transmitted inside the optical waveguide.
  • the material of the dielectric layer 194 is a low-fold material, such as glass or tree fingers.
  • the thickness of the dielectric layer 194 can be: greater than or equal to 0.1 mm and less than or equal to 1 mm. Specifically, the thickness of the dielectric layer 194
  • the thickness and refractive index settings can be combined with the near-eye display settings.
  • the exit pupil size of the optical machine in the equipment matches the FOV size.
  • the dielectric layer 194 can also be air.
  • the waveguide substrate in the optical waveguide 10A is composed of a dielectric layer 194, that is, part of the waveguide substrate in the coupling region 10Ai is used to carry the coupling grating 11, and the coupling region 10Ao is used to carry the coupling grating 12.
  • the part of the waveguide substrate and the dielectric layer 194 in the light propagation area 10Ap have an integrated structure, have the same materials and the same refractive index, and can be formed through the same manufacturing process.
  • the bandwidth of the incident light is less than or equal to 5 nm.
  • the incident light can be a laser light source. This embodiment limits the bandwidth range of the incident light so that the light emitted by the optical engine 20 onto the coupling grating 11 is a narrow-bandwidth light source, which is beneficial to ensuring the image quality of the virtual image formed by the optical waveguide 10A projected onto the human eye.
  • the incident light projected by the optical machine 20 to the coupling grating 11 provided in this application is the incident light with a narrow wavelength bandwidth. Specifically, it refers to limiting the incident wavelength bandwidth for the light entering the coupling grating from the optical machine. The purpose is to ensure that Observations of the environment have a smaller impact. Assume that the wavelength bandwidth of the incident light is 1nm (532nm ⁇ 533nm).
  • the first grating layer 19A and the second grating layer 19B are designed for this wavelength and can normally transmit other wavelengths such as 520nm without affecting the observation of the environment.
  • the ambient light will be diffracted when it hits the first grating layer 19A and the second grating layer 19B. That is to say, the external environment assumes that what we observe is White screen, then part of the external ambient light in the 520-540nm band is diffracted away, and the transmittance is lower than that of other bands, which affects the color ratio, that is, the color is distorted. , thus affecting the observation of the external environment.
  • the incident light projected by the optical engine 20 onto the coupling grating 11 is diffracted by the coupling grating 11 and separated from the angle of the incident light. It needs to be transmitted in the medium body 194. In the light propagation area 10Ap total reflection propagation.
  • the period of the coupling grating 11 satisfies the conditions: ⁇ /d>2*sin(FOVx), sin(FOVx)+ ⁇ /d ⁇ n_base*sin(75°) , where ⁇ is the wavelength of the incident light incident on the coupling grating, d is the period of the coupling grating, FOVx is the maximum incident angle of the incident light incident on the coupling grating in the horizontal direction, n_base refers to The refractive index of the waveguide substrate corresponding to the coupling grating 11, in the embodiment shown in Figure 75, can be understood as: the waveguide substrate corresponding to the coupling grating 11 is part of the dielectric layer and part of the second layer below the coupling grating 11 The grating layer, that is, n_base is the refractive index of the waveguide base corresponding to the coupling grating 11, which is part of the dielectric layer and part of the second grating layer below the coupling
  • Figure 76 shows a K-space schematic diagram of the grating period of an optical waveguide provided by an embodiment of the present application.
  • Line circle, the angular range of the light emitted by the optical machine can be described as the box area in the K-space diagram.
  • the angle changes, and the performance in the K-space is that the box is translated, and the translated
  • the distance is related to the incident wavelength and the coupling grating period, which is equal to ⁇ /d.
  • the angle ranges cannot intersect after translation (if the angle ranges intersect, it will cause angular aliasing, thus producing ghost images), nor can it exceed the circle of n_base ( If it exceeds the circle of n_base, the light will not be able to propagate in the medium n_base), so the grating period coupled into the grating needs to meet the conditions: ⁇ /d>2*sin(FOVx), sin(FOVx)+ ⁇ /d ⁇ n_base* sin(75°).
  • the periods of the coupling grating and the relay grating on the optical waveguide 10A (if the optical waveguide includes a relay grating between the coupling grating and the coupling grating) also need to meet the grating period of the coupling grating. conditions that need to be met.
  • Figure 77 shows a K-space schematic diagram of the grating period of an optical waveguide provided by an embodiment of the present application.
  • the periodic direction and size of the coupling grating 11, the relay grating 13 and the coupling grating 12 need to form a closed K space. If this condition is met, it can be ensured that the virtual image projected by the optical waveguide will not be distorted, that is, it can be guaranteed The authenticity of the image improves the image display effect of the optical waveguide.
  • the optical waveguide 10A provided by this application includes a coupling grating 11, a relay grating 13 and an outcoupling grating 12.
  • the relay grating 13 is located between the coupling-in region 10Ai and the coupling-out region 10Ao, and the first grating layer 19A and the second grating layer 19B in the light propagation region 10Ap are located between the coupling-in grating 11 and the coupling-out region 10Ao.
  • the cross-sectional lines on the periphery of the coupling grating 11 , the relay grating 13 and the coupling grating 12 represent the first grating layer 19A and the second grating layer 19B, and may also represent the light transmission area 10Ap.
  • the coupling grating 12 may be a one-dimensional grating.
  • the coupling grating 11, the coupling grating 12, and the relay grating 13 can be different types of gratings; any one of the coupling grating 11, the coupling grating 12, and the relay grating 13 is different from the first grating.
  • Both the first grating layer 19A and the second grating layer 19B can be the same type of grating, for example, they can be volume holographic gratings; the coupling grating 11, the coupling grating 12, the relay grating 13, the first grating layer 19A and the second grating.
  • Layer 19B may be a volume holographic grating.
  • the coupling grating 12 may be a two-dimensional grating, and the light transmission area 10Ap is located between the coupling grating 11 and the coupling grating 13.
  • the first The grating layer 19A and the second grating layer 19B fill all areas between the coupling grating 11 and the coupling grating 12.
  • the optical waveguide 10A provided in this embodiment does not have a relay grating.
  • the light coupled into the grating 11 propagates to the outcoupling grating 12 through total reflection of the first grating layer 19A and the second grating layer 19B.
  • the cross-sectional lines on the periphery of the coupling grating 11 and the coupling grating 12 represent the first grating layer 19A and the second grating layer 19B, and may also represent light rays. Transmission area 10Ap.
  • the coupling grating 11, the coupling grating 12, and the relay grating 13 can be different types of gratings; any one of the coupling grating 11, the coupling grating 12 and the first grating layer 19A and The second grating layer 19B can all be the same type of grating, for example, it can be a volume holographic grating; the coupling grating 11 , the coupling grating 12 , the first grating layer 19A and the second grating layer 19B can all be volume holographic gratings.
  • the coupled propagation angle range ⁇ 1 to ⁇ 2 can be obtained, which needs to pass through the first grating layer 19A and the second grating layer 19B. Diffraction occurs and propagates forward, and the period acting in the first grating layer 19A and the second grating layer 19B corresponding to the corresponding angle is ⁇ /(2*n_base*sin( ⁇ )).
  • the FOV range of the incident light is -15 ⁇ 15°
  • the incident wavelength is 532nm
  • the period range of the coupling grating 11 is 533.7nm ⁇ 1.028um. Assume that the coupling grating If the period of 11 is set to 600 nm, the corresponding diffraction angle is 28.9° to 61.8°, and the corresponding periods of the first grating layer 19A and the second grating layer 19B are 233.2 nm to 423.4 nm. The larger the FOV range of the incident light, the larger the upper limit of the diffraction angle is when the period of the coupling grating 11 and the refractive index of the dielectric layer 194 remain unchanged, then the period of the first grating layer 19A and the second grating layer 19B The lower limit is smaller.
  • the larger the FOV range of the incident light projected by the optical engine 20 onto the coupling grating 11 the greater the FOV range of at least one of the first grating layer 19A and the second grating layer 19B.
  • the larger the FOV range of the incident light projected onto the coupling grating 11 by the optical engine 20 the diffraction will occur when the period of the coupling grating 11 and the refractive index of the dielectric layer 194 remain unchanged.
  • the larger the upper limit of the angle the smaller the lower limit of the number of periods that at least one of the first grating layer 19A and the second grating layer 19B has.
  • the present application uses a multiplexed volume holographic grating method to achieve total reflection and propagation of light in the optical waveguide and transmit ambient light.
  • the current FOV is smaller at 12° and the PPD requires a minimum of 18PPD, so the number of cycles of the first grating layer 19A and the second grating layer 19B is at least greater than 216.
  • At least one of the first grating layer 19A and the second grating layer 19B has different periods. If the first grating layer 19A and the second grating layer 19B both have a single period, and their periods are the same, they work in the same reflection and diffraction order, resulting in a low ambient light transmittance when observing the outside world, that is to say. , the user can see the virtual image projected by the coupling grating, but cannot clearly see the environment outside the near-eye display device.
  • this application can, on the one hand, perform total reflection propagation of incident light at multiple viewing angles, allowing more light energy to enter and couple out.
  • the grating can improve the diffraction efficiency; on the other hand, it can ensure the transmittance of ambient light, so that the user can not only clearly see the virtual image projected by the coupling grating, but also clearly see the environment outside the near-eye display device.
  • both the first grating layer 19A and the second grating layer 19B have different periods. This solution can improve the light transmittance of the optical waveguide by limiting the first grating layer and the second grating layer to have different periods.
  • both the first grating layer 19A and the second grating layer 19B are volume holographic gratings.
  • This solution multiplexes volume holographic gratings with different periods, so that the light propagation area 10Ap can fully reflect the incident light entering the optical waveguide, and also have good transmittance for ambient light.
  • holographic grating has the advantage of being thin and light. Therefore, this solution is beneficial to the lightweight design of the optical waveguide 10A.
  • the dielectric layer 194 has a flat structure, and all grating structures formed on the top and bottom surfaces of the dielectric layer 194 can be volume holographic gratings. All the grating structures described here are It includes a coupling grating 11, a coupling grating 12, a first grating layer 19A and a second grating layer 19B.
  • the number of periods that one of the first grating layer 19A and the second grating layer 19B has depends on the required angular resolution of the optical waveguide 10A and the size of the FOV of the incident light of the optical machine 20 .
  • Period is an important feature of the grating structure. Different periods correspond to different Bragg angles, that is, different incident angles. Therefore, the diffraction efficiency of a grating structure with different periods is higher than that of a grating structure with only one period, and the grating structure with different periods can not only completely reflect the light in the optical waveguide, but also transmit ambient light.
  • the period range of the first grating layer 19A and the second grating layer 19B is: greater than or equal to 100 nm and less than or equal to 700 nm.
  • the period corresponds to the incident angle.
  • the volume shrinkage range of the material of the first grating layer 19A and the volume shrinkage range of the material of the second grating layer 19B are: less than or equal to 0.1%.
  • This solution can reduce the lateral and longitudinal change rates of the first grating layer 19A and the second grating layer 19B through a grating structure with a smaller volume shrinkage, thereby reducing the changes in period, thickness and inclination, ensuring that the first grating There is no major deviation between the design of the layer 19A and the second grating layer 19B and the actual angle and efficiency.
  • the coupling grating 11, the first grating structure 195 and the coupling grating 12 are located on the top surface of the dielectric layer 194, and on the bottom surface of the dielectric layer 194 is the second grating layer 19B.
  • the The two grating layers 19B not only cover the dielectric layer 194 of the light propagation area 10Ap, but also cover the dielectric layers of the coupling area 10Ai and the outcoupling area 10Ao, so that the surface of the optical waveguide 10A on one side of the bottom surface of the dielectric layer 194 has better Flatness.
  • the surface of the coupling grating 11 facing away from the dielectric layer, the surface of the first grating layer 19A facing away from the dielectric layer 194, and the surface of the outcoupling grating 12 facing away from the dielectric layer 194 may form a coplanar structure, so as to This allows the surface of the optical waveguide 10A on one side of the top surface of the dielectric layer 194 to have better flatness.
  • the optical waveguide 10A further includes a first protective layer 151 and a second protective layer 152.
  • the first protective layer 151 is located on the side of the first grating layer 19A away from the dielectric layer 194.
  • the first protective layer 151 covers the first grating layer 19A.
  • the first protective layer 151 is used to protect the first grating layer 19A, the coupling grating 11 and the coupling out grating 12, so that the first grating layer 19A, coupling in The grating 11 and the outcoupling grating 12 are protected from external dust, air or moisture.
  • the second protective layer 152 covers the surface of the second grating layer 19B and is used to protect the second grating layer 19B so that the second grating layer 19B is protected from external dust, air or water vapor, thereby ensuring the diffraction of the optical waveguide. efficiency and optical performance.
  • the optical waveguide uses the total reflection of the first grating layer and the second grating layer to propagate the incoming image in its light transmission area 10Ap while ensuring the transmittance of the ambient light of the entire optical waveguide, ensuring that people The eyes can observe the external environment normally.
  • the film thickness of the first grating layer and the second grating layer may be: >20um.
  • the bandwidth of the incident light that the first grating layer and the second grating layer cooperate with is less than 5 nm (that is, the incident light with a narrow bandwidth) to achieve total reflection propagation of the coupled light.
  • the production process of the first grating layer and the second grating layer can be obtained through multiple exposures, so that the first grating layer and the second grating layer have multiple periods, so as to achieve total reflection and propagation of incident light and enhance ambient light. transmittance.
  • Figure 80 shows a schematic diagram of the diffraction efficiency of a single grating.
  • the horizontal axis represents the incident angle
  • the vertical axis represents the diffraction efficiency.
  • Figure 80 it can be seen that this application can obtain a small angle range in the angular space.
  • 1 is the efficiency target value we need, that is, total reflection propagates forward
  • DE_t is other angles.
  • minimize the objective function as the goal of optimizing the grating structure. This goal represents our expectation to obtain the forward propagation image of the waveguide reflection while ensuring the transmission of ambient light. Rate.
  • Optimization is performed through a global optimization algorithm such as a simulated annealing algorithm or a genetic algorithm to obtain specific parameter values of the first grating layer 19A and the second grating layer 19B and the optimized effect.
  • a global optimization algorithm such as a simulated annealing algorithm or a genetic algorithm to obtain specific parameter values of the first grating layer 19A and the second grating layer 19B and the optimized effect.
  • the target optimization effect is shown in Figure 81 and Figure 82.
  • Figure 81 shows a schematic diagram of the wavelength bandwidth.
  • the horizontal axis represents the incident wavelength
  • the vertical axis represents the diffraction efficiency. It can be seen from Figure 81 that the optimized multiplexed volume holographic grating only has a very narrow bandwidth wavelength range. High diffraction efficiency, high efficiency transmission for other wave bands, without affecting the observation of the external environment.
  • Figure 82 shows a schematic diagram of the angular bandwidth.
  • the horizontal axis represents the incident angle on the multiplexed volume holographic grating
  • the vertical axis represents the diffraction efficiency. It can be seen from Figure 82: only within the applied angle range, The multiplex volume holographic grating provided by this application has high-efficiency diffraction characteristics, which also ensures total reflection propagation at the required angle and high-efficiency transmission to other external environmental angles.
  • the exposure diagram is shown in Figure 83.
  • the first grating layer 19A and the second grating layer 19B on the light propagation area 10Ap need to diffract the light hitting this area and continue to propagate forward while maintaining the original direction and angle.
  • the multiplexing characteristics require exposing multiple different gratings to the incident light in different fields of view.
  • the angle of exposure is the direction of the incident light and the required diffraction direction.
  • the grating formed by exposure in two directions is the first grating layer 19A and the second grating layer 19B formed after multiple exposures for the direction of the incident light. It can be diffracted to the required diffraction direction for multiple fields of view in the waveguide, so that it can propagate forward to the coupling grating after total reflection in this area, and be coupled out to the human eye normally.
  • the production process of multiple exposures is as shown in Figure 83.
  • the first exposure is exposed at angle 1, and the second exposure is exposed at angle 2.
  • the third exposure is at angle 3, and so on.
  • Multiple exposures may be performed during the process of forming the first grating layer 19A and the second grating layer 19B.
  • the exposure angle can be increased sequentially, as shown in Figure 83, angle 1 ⁇ angle 2 ⁇ angle 3.
  • the coupling gratings 11 are distributed on both sides of the dielectric layer 194 , which can improve the coupling efficiency of incident light.
  • the coupling grating 11 located on the top surface of the dielectric layer 194 and the coupling grating 11 located on the bottom surface of the dielectric layer can have different inclination angles, which can enable the coupling grating 11 to couple in a larger range of incident angles. light.
  • the outcoupling gratings 12 are distributed on both sides of the dielectric layer 194, which can increase the outcoupling energy of the incident light, so that more light is coupled out to the human eye, and a better image can be obtained. quality.
  • the coupling grating 12 located on the top surface of the dielectric layer 194 and the coupling grating 12 located on the bottom surface of the dielectric layer may have different inclination angles, which enables the coupling grating 12 to couple out light in a wider angular range. .
  • the optical waveguide 10A includes a functional area 10AA and an edge area 10AE.
  • the functional area 10AA performs the functions of the optical waveguide 10A in diffracting incident light, total reflection propagation, and coupling out light.
  • the edge area 10AE surrounds the functional area 10AA, and the edge area 10AE can transmit ambient light.
  • the edge area 10AE and the functional area 10AA are spliced together to form the shape of a lens of a near-eye display device. There is no need to configure the first grating layer and the second grating layer at the edge area 10AE.
  • the optical waveguide provided by this solution combines the functional area and the edge area.
  • the edge area can be made of lighter material, which is conducive to lightweighting the optical waveguide.
  • the refractive index of the edge area 10AE is smaller than the refractive index of the functional area 10AA, or the material of the edge area 10AE is different from the material of the functional area 10AA.
  • the edge area 10AE can be made of low refractive index material or low density material, which is beneficial to the overall lightweight design of the near-eye display device.
  • the functional area 10AA includes the coupling grating 11, the relay grating 13, the coupling grating 12 and the first grating layer 195 and the second grating layer 196 in the light propagation area 10Ap.
  • the area between the coupling grating 11 and the relay grating 13, and the area between the relay grating 13 and the outcoupling grating 12 are the light propagation areas 10Ap.
  • the functional area 10AA includes the coupling grating 11, the coupling grating 12 and the first grating layer 195 and the second grating layer 196 in the light propagation area 10Ap.
  • the coupling grating The area between 11 and the coupling grating 12 is the light propagation area 10Ap.
  • the optical waveguide 10A provided by the embodiment shown in Figure 75 can be a single-layer single-sided grating optical waveguide structure, that is, the optical waveguide has only one dielectric layer, and the coupling grating and the coupling grating are only provided on one side of the dielectric layer.
  • the optical waveguide 10A provided by the embodiment shown in Figure 84 can be a single-layer double-sided grating optical waveguide structure, that is, the optical waveguide has only one dielectric layer, and the coupling grating and the coupling grating are only provided on both sides of the dielectric layer.
  • the optical waveguide provided by this application can also be a multi-layer single-sided structure or a multi-layer double-sided structure.
  • “Multilayer” refers to an optical waveguide having two or more dielectric layers arranged in a stack.
  • “Multilayer single-sided architecture” means that the optical waveguide has two or more dielectric layers, and each dielectric layer has only one side with a grating structure.
  • “Multi-layer double-sided architecture” means that the optical waveguide has two or more dielectric layers, and grating structures are provided on both sides of each dielectric layer.
  • the number of layers of the optical waveguide may be two layers, for example, one layer transmits red light and blue light, and the other layer transmits blue light and green light.
  • the number of layers of the optical waveguide may also be three.
  • these three layers transmit red light, blue light and green light respectively.
  • This solution limits the single-layer architecture or the three-layer architecture of the optical waveguide.
  • the first grating layer and the second grating layer can be used as the medium for total reflection propagation in the light propagation area. This solution is flexible. Good advantage.
  • Figure 87 schematically expresses a three-layer single-sided optical waveguide architecture.
  • the optical waveguide 10A includes three dielectric layers 194 , which are stacked.
  • the grating structures provided on the top and bottom surfaces of each dielectric layer 194 are the same. In other embodiments, the grating structures provided on the top or bottom surfaces of dielectric layers of different layers may also be different.
  • the architecture of each dielectric layer 194 and the coupling grating 11, coupling grating 12, first grating layer 195A, and second grating layer 195B on the top and bottom surfaces is the same as that of Figure 75
  • the optical waveguide architecture shown is the same.
  • the uppermost dielectric layer 194 and the coupling grating 11 are used to couple the red incident light R
  • the middle dielectric layer 194 and the coupling grating 11 are used to couple the green incident light G
  • the bottom dielectric layer 194 and the coupling grating 19 are used to couple the green incident light G.
  • the grating 11 is used to couple in the blue incident light B. All coupling gratings 12 in the three-layer architecture project coupling light to the human eye, so that the human eye can see a color virtual image.
  • the first grating layer 195 and the second grating layer 196 are volume holographic gratings.
  • the number of cycles of each layer may be less than the cycles of the first grating layer 195 and the second grating layer 196 in the embodiment shown in FIG. 75 quantity. Therefore, this embodiment can reduce the number of exposures of the first grating layer 195 and the second grating layer 196 of each layer structure, thereby reducing the process difficulty.
  • the optical waveguide provided in one embodiment of the present application is a diffractive optical waveguide.
  • the diffractive optical waveguide uses the diffraction characteristics of the grating to design an "optical path", allowing light to propagate on the designed path, and converting micro-projection systems (such as near-eye display devices) into The light emitted by the optical machine is introduced into the human eye.
  • Diffraction grating is an optical element with periodic structure and is the core part of diffractive optical waveguide.
  • the diffracted light wave can be Guides are divided into two categories: surface relief grating waveguides and volume holographic grating waveguides.
  • Holographic gratings made of holographic materials have many benefits, such as angle selectivity, wavelength selectivity and high diffraction efficiency.
  • the propagation process of light in the volume holographic grating waveguide is basically the same as that in the surface relief grating waveguide. The difference is that the volume holographic grating is not "engraved” but uses alternating light and dark interference fringes formed by two beams of coherent light to expose the light-sensitive film on the substrate, thereby forming a period with a refractive index difference at the molecular level.
  • Sexual spatial distribution is not “engraved” but uses alternating light and dark interference fringes formed by two beams of coherent light to expose the light-sensitive film on the substrate, thereby forming a period with a refractive index difference at the molecular level.
  • an optical waveguide 10A provided in one embodiment includes a waveguide substrate 19 and a grating layer 197 formed on the surface of the waveguide substrate 19.
  • the grating layer 197 is a volume holographic material.
  • the grating layer 197 is used to make a grating structure, such as coupling. Grating 11 and coupling-out grating 12.
  • the waveguide substrate 19 can be a high refractive index material, used to carry the grating layer 197 during the process of making the grating layer 197, and also used for total reflection propagation of light. Specifically, the incident light enters the waveguide substrate 19 through the coupling grating 11, and propagates through total reflection in the waveguide substrate 19. When it propagates to the coupling grating 12, it is coupled out to the human eye by the coupling grating 12.
  • the optical waveguide 10A is also used for transmitting ambient light. Through the optical waveguide 10A, the human eye not only sees the virtual image coupled out by the coupling grating 12, but also sees the external environment.
  • volume holographic materials expanding the refractive index difference of different components is the key to obtaining high refractive index modulation.
  • a high refractive index difference means low material compatibility, which makes it easy for micro-region agglomeration between different components to form large polymer particles, which is prone to light scattering, resulting in low Excellent stability and high haze.
  • the haze of volume holographic materials seriously affects the clarity and look and feel of external windows.
  • the grating layer 197 is a volume holographic material and covers the surface of the waveguide substrate 19
  • the positions of the coupling grating 11 and the coupling grating 12 are grating structures made of volume holographic material, except for the coupling grating.
  • the other areas of the grating layer 197 outside the coupling grating 11 and the coupling-out grating 12 are covered with volume holographic materials on the waveguide substrate. This part of the volume holographic material and the volume holographic materials at the coupling-in grating 11 and coupling-out grating 12 are prone to produce high Haze problem.
  • One embodiment of the present application provides an optical waveguide structure that can reduce the haze of the volume holographic material by changing the internal structure or the arrangement of the internal components of the volume holographic material.
  • an optical waveguide 10A provided in one embodiment includes a waveguide substrate 19 and an anti-reflection layer 16 .
  • the anti-reflection layer 16 is formed on the surface of the waveguide substrate 19 .
  • the anti-reflection layer 16 includes a volume hologram material.
  • the anti-reflection layer 16 is at least part of the grating layer 197, which is a layer structure disposed on the surface of the waveguide substrate 19 for making grating structures (such as the coupling grating 11 and the coupling grating 12).
  • the grating layer The material 197 is a volume holographic material.
  • the grating structure (such as the coupling grating 11 and the coupling grating 12) formed on the waveguide substrate 19 is a volume holographic grating.
  • the antireflection layer 16 is located between the coupling grating 11 and the coupling grating 12.
  • the antireflection layer 16 does not have the function of diffracting light, but only has the function of transmitting light, and through the antireflection layer 16
  • the internal structure of the polymer can solve the problem of micro-region agglomeration between different internal components and the formation of large polymer particles, which are prone to light scattering, resulting in low stability and high haze.
  • FIG. 90 is an enlarged schematic diagram of part I in FIG. 89 .
  • the antireflection layer 16 includes a high refractive index phase region 161 and a low refractive index phase region 162 with different refractive indexes.
  • the high refractive index phase region 161 and the low refractive index phase region 162 are stacked on the waveguide substrate 19.
  • the high refractive index phase region 161 and the low refractive index phase region 162 are different regions separated from each other.
  • the refractive index range of the high refractive index phase region 161 is: 1.5-2.0, and the refractive index range of the low refractive index phase region 162 is 1.1. -1.5, the components in the high refractive index phase region 161 and the low refractive index phase region 162 are different. Different components can be understood as different types of materials. Materials with the same components will not agglomerate and form large polymer particles, which can make the optical waveguide have low haze and improve the light transmittance of the optical waveguide. .
  • the internal structure of the anti-reflection layer 16 is formed into alternately distributed high refractive index phase regions 161 and low refractive index phase regions 162, and the high refractive index phase regions 161 and low refractive index phase regions 162 have different compositions.
  • materials with the same components in the antireflection layer 16 are gathered in one phase region.
  • the components in the high refractive index phase region 161 are polymers and nanoparticles, while the components in the low refractive index phase region 162
  • the components in it are high molecular polymers formed by monomers, that is, sub-high molecular polymers. In this way, the polymer compounds and sub-polymer compounds are separated instead of mixed together, and it is not easy to form micro-area agglomeration.
  • the phase regions are alternately distributed along the direction perpendicular to the surface of the waveguide substrate 19 .
  • the interphase distribution can be understood as the arrangement of ABABAB.
  • the low refractive index phase regions 162 are stacked between adjacent high refractive index phase regions 161 , or the high refractive index phase regions 162 are stacked between adjacent low refractive index phase regions 161 . In the embodiment shown in FIG.
  • the number of high refractive index phase regions 161 and low refractive index phase regions 162 are both three.
  • the three high refractive index phase regions 161 are respectively located at the first, second and third high refractive index phase regions 161 .
  • the three low refractive index phase regions 162 are located in the second, fourth and sixth layers respectively.
  • the number of the high refractive index phase region 161 and the low refractive index phase region 162 may both be one, and the high refractive index phase region 161 is stacked between the low refractive index phase region 162 and the waveguide substrate 19, or, the low refractive index phase region 161 is stacked between the low refractive index phase region 162 and the waveguide substrate 19.
  • the refractive index phase region 162 is stacked between the high refractive index phase region 161 and the waveguide substrate 19 .
  • the number of the high refractive index phase region 161 and the low refractive index phase region 162 may also be two, four or more.
  • the material of the anti-reflection layer is a volume holographic material.
  • the main body of the volume holographic material is a high molecular polymer material, and the main element composition of the high molecular polymer material includes: one or more of C, H, O, N, S, P or all.
  • the volume holographic material further includes nanoparticles, and the diameter of the nanoparticles is: 1 nm to 50 nm.
  • at least part of the nanoparticles are distributed in the high refractive index phase region, and the nanoparticles distributed in the high refractive index phase region are titanium dioxide, zirconium dioxide, zinc sulfide, and carbon quantum dots. One or several or all of them.
  • at least part of the nanoparticles are distributed in the low refractive index phase region, and the nanoparticles distributed in the low refractive index phase region are one or all of silicon dioxide and magnesium fluoride. .
  • the volume fraction content of the nanoparticles is 0-60%.
  • This solution controls the formation of high refractive index regions and low refractive index phase regions as well as their refractive index by limiting the volume fraction of nanoparticles, and solves the problem of optical waveguide haze. Specifically, there should not be too many nanoparticles, as too many will cause the nanoparticles to agglomerate themselves and increase haze; nor should there be too few nanoparticles, as too few will reduce the refractive index difference between different phase regions.
  • the high refractive index phase region and the low refractive index phase region are layer structures that are sequentially stacked and distributed on the surface of the waveguide substrate 19.
  • the size of the layer structure along the direction perpendicular to the surface of the waveguide substrate is the thickness of the layer structure.
  • the thickness of the layer structure formed by the high refractive index phase region is the same as the thickness of the layer structure formed by the low refractive index phase region.
  • the thickness of the layer structure formed by the high refractive index phase region and the thickness of the layer structure formed by the low refractive index phase region may also be different.
  • the thickness of each high refractive index phase region ranges from 100 nm to 1000 nm.
  • the thickness of each low refractive index phase region may also range from 100 nm to 1000 nm.
  • the thickness of each of the high refractive index phase regions or the thickness of each of the low refractive index phase regions is: 200 nm.
  • the volume holographic material only exists in the non-grating region 19S (the region schematically marked between the coupling grating 11 and the coupling grating 12 in the figure).
  • the anti-reflection layer 16 while the coupling-in grating 11 and the coupling-out grating 12 are only diffraction grating structures made of volume holographic materials and do not have an anti-reflection layer structure.
  • the implementation shown in Figure 89 can reduce the haze at the non-grating area 19S and improve light uniformity and ambient light transmittance.
  • an anti-reflection layer structure can also be provided at the position where the grating structure is located. That is to say, the position of the grating structure has a diffraction grating structure and an anti-reflection layer structure.
  • the direction and period of the grating vector of the diffraction grating structure are It is set to meet the diffraction optical performance.
  • the direction and period of the grating vector at the coupling grating position are set to satisfy the coupling of incident light into the waveguide substrate.
  • the direction and period of the grating vector at the coupling out grating position are set to satisfy the coupling of light. Out to the human eye.
  • the position of the relay grating can also be equipped with an anti-reflection layer structure.
  • the anti-reflection layer 16 of the optical waveguide 10A is formed in the non-grating region 19S and the position where the outcoupling grating 12 is located.
  • the anti-reflection layer in the non-grating region 19S has the same structure as the anti-reflection layer 16 in the embodiment shown in FIG. 89 .
  • FIG. 92 is an enlarged schematic diagram of the position of the coupling grating 12 in FIG. 91 . Referring to Figure 92, at the position of the coupling grating 12, the antireflection layer 16 and the coupling grating 12 form a common structure 17.
  • the common structure 17 includes grating microstructures arranged along the vector direction of the coupling grating 12.
  • the common structure 17 also includes high refractive index phase regions 161 and low refractive index phase regions 162 alternately distributed along the normal direction of the optical waveguide 10A.
  • This solution can improve the light transmittance of the coupling grating 12 by arranging the anti-reflection layer 16 at the position of the coupling grating 12.
  • the coupling grating 12 can not only couple the light in the optical waveguide 10A to the human eye, but also transmit light through the coupling grating 12. Through ambient light, the position of the coupling grating 12 of the optical waveguide provided by this solution has better light transmittance.
  • the anti-reflection layer 16 is disposed in all areas of the coupling grating 12 , that is, the anti-reflection layer 16 and the coupling grating 12 have the same outer contour.
  • the connecting surface of the coupling grating 12 and the waveguide substrate 19 is the coupling bottom surface 12S1 of the coupling grating 12, and the coupling surface of the coupling grating 12 is away from the waveguide substrate 19.
  • the anti-reflection layer 16 is formed on the coupling bottom surface 12S1 and the coupling top surface 12S2 of the coupling grating 12 and forms part of the common structure 17 with the coupling grating 12 . Between surface 12S2.
  • the anti-reflection layer 16 is formed at the position of the coupling grating 12 by using multiplexed holographic technology. This solution limits the specific architecture of a common structure formed by the coupling grating and the anti-reflection layer.
  • This solution does not require the addition of volume holographic materials in the area outside the coupling grating. Instead, the dual-beam exposure is based on the coupling grating itself to obtain enhancement.
  • the transparent layer structure can ensure or try not to affect the diffraction efficiency of the coupling grating. If material is added outside the coupling top surface to make an anti-reflection layer, the added material will affect the diffraction efficiency of the coupling grating.
  • the anti-reflection layer 16 may also be provided in only part of the outcoupling grating 12 .
  • the left edge of the anti-reflection layer 16 is located inside the coupling grating 12, and there is no anti-reflection layer 16 on the left side of the anti-reflection layer 16 where the coupling grating 12 is located.
  • the right edge of the anti-reflection layer 16 coincides with the right edge of the coupling grating 12 .
  • the anti-reflection layer 16 in the optical waveguide 10A is only provided at the position where the coupling grating 12 is located.
  • the anti-reflection layer 16 and the coupling grating 12 form a common structure, and in the non-grating area 19S No anti-reflection layer is provided.
  • This solution is mainly aimed at improving the transmittance of ambient light based on the position of the coupling grating 12 .
  • the production of anti-reflection layer in a small area is conducive to saving production costs while obtaining the required optical waveguide solution.
  • Figure 95 is a schematic diagram of a specific manufacturing method for forming a unified structure composed of an anti-reflection layer and a grating structure. It includes the first production method M1 and the second production method M2.
  • the schematic diagram in the upper rectangular frame in Figure 95 is the first production method M1.
  • the lower rectangular frame in Figure 95 The schematic diagram inside shows the second production method M2.
  • the grating structure taking the coupling grating 12 as an example
  • the holographic material is formed on the surface of the waveguide substrate, and the anti-reflection layer 16 and the grating structure are formed through a double-beam exposure process (taking the coupling grating 12 as an example).
  • the angle between the two beams in the double-beam exposure process for making the anti-reflection layer 16 is the first angle ⁇ 1.
  • the angle between the two beams and the anti-reflection layer 16 is half of the first angle ⁇ 1.
  • the two beams are symmetrically distributed on both sides of the anti-reflection layer 16, and the angle bisector OC of the angle formed by the two beams is parallel to the surface of the waveguide substrate (or the plane where the anti-reflection layer is located). In this way, the double beams Exposure will form high refractive index phase areas and low refractive index phase areas of the anti-reflection layer stacked with the waveguide base.
  • the angle between the two beams in the double-beam exposure process for making the grating structure is the second angle ⁇ 2.
  • the angle bisector OC formed by the two beams in the double beam forms an angle with the surface of the waveguide substrate, so that a diffractive waveform is formed after exposure.
  • the first angle ⁇ 1 and the second angle ⁇ 2 may be different.
  • the double-beam exposure step of making the anti-reflection layer 16 and the double-beam exposure step of making the coupling grating 12 are shown separately.
  • the order of these two steps can be exchanged, or That is to say, the anti-reflection layer 16 can be formed by exposure first, and then the coupling grating 12 can be formed by exposure; or the coupling grating 12 can be formed by exposure first, and then the anti-reflection layer 16 can be formed by exposure.
  • This solution only needs to adjust the angle of the double-beam exposure.
  • the integrated structure of the anti-reflection layer 16 and the grating structure can be realized in the same area. It has the advantages of simple manufacturing process and high efficiency. The advantage of low cost.
  • the present application provides a method for manufacturing an optical waveguide, which is used to manufacture the aforementioned optical waveguide with an anti-reflection layer.
  • a method of manufacturing an optical waveguide includes the following steps:
  • a substrate which is a waveguide substrate of the optical waveguide.
  • the substrate can be a glass material.
  • the refractive index of the substrate needs to be sufficient to achieve total reflection propagation of light therein, and the substrate also needs to be translucent to allow ambient light to pass through.
  • a material layer is provided on the surface of the substrate, and the material layer includes volume holographic material.
  • the material layer is disposed on the surface of the substrate by coating.
  • the coating method includes spin coating, pull-up dip coating, spray coating, gravure coating, reverse roller coating, knife roller coating, metering Any of rod coating, slot die coating, dipping, curtain coating, and air knife coating.
  • Preprocess the substrate with the material layer Preprocess the substrate with the material layer.
  • the steps of pre-treatment include: high temperature treatment at 25 ⁇ 100°C, low pressure treatment, light protection treatment, and room temperature treatment.
  • the material formula of the material layer contains solvents, which need to be removed in pre-treatment. Some solvents have high boiling points, so low-pressure treatment is required. Low pressure can specifically be understood as pressure below 1 atmosphere.
  • a double-beam exposure process is performed, so that the material layer forms a structure with high refractive index phase areas and low refractive index phase areas alternately distributed.
  • the steps of curing and molding include high-temperature curing and molding.
  • the temperature of the high-temperature curing and molding is 40-150°C.
  • the light intensity of the light-curing and molding is 0.1-5000mW cm-2.
  • the wavelength range of the light-curing and molding is The range is 254nm to 1000nm, and the type of light used for the light curing molding includes any one of UVA, UVB, UVC, visible light, and infrared light bands.
  • a material layer is coated on the substrate, and the material layer is defined as a volume holographic material, and the material layer is modulated into an anti-reflection layer with a high refractive index phase area and a low refractive index phase area through a double-beam exposure process to achieve reduction of Optical waveguide haze improves light uniformity and transmittance.
  • the material layer includes a high molecular polymer, a monomer, a photoinitiation system, and a solvent.
  • the high molecular polymer is a polymer containing C, H, O, and N with a molecular weight greater than 1000.
  • the monomer Including at least one of acrylates, acrylamide, sulfhydryl-containing compounds, allyl compounds, and vinyl compounds, the photoinitiation system is used to absorb laser energy and form active materials, so that the active materials Reacts with the monomer to convert the monomer into a sub-polymer polymer.
  • the high molecular polymer includes polyether, polyvinyl acetate, polyvinyl acetate-propylene copolymer, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polyphenylene At least one of ethylene, polycarbonate, polyurethane, polyester polyol, cellulose acetate, and polyvinyl alcohol.
  • the acrylate compounds include polyethylene glycol acrylate, 3-hydroxypropyl acrylate, pentabromophenyl acrylate, ethoxylated trimethylolpropane triacrylate, isooctyl acrylate, and sulfur-containing acrylic acid. At least one of esters, phenyl-containing acrylates, benzyl-containing acrylates, biphenyl-containing acrylates, and pentaerythritol tetraacrylate and their corresponding methacrylate analogues;
  • the acrylamide compounds include at least one of methyl alcohol acrylamide, N-benzyl methacrylamide and N,N-dimethylacrylamide, and the mercapto-containing compounds include propanethiol, bis(3 -At least one of ethylene glycol, trimethylolpropane tris(3-mercaptopropionate) and tetrakis(3-mercaptopropionate) pentaerythritol;
  • the allyl compound includes at least one of allyl urea, allyl ethyl ether, allyl phenyl ether, 1-allyl piperazine and triallyl isocyanurate;
  • the vinyl compounds include N-vinylcarbazole, N-vinylimidazole, dibromo-N-vinylcarbazole, tribromo-N-vinylcarbazole, tetrabromo-N-vinylcarbazole, At least one kind of N-vinylpyrrole.
  • Figure 97 is a schematic diagram of the changes in each component during the double-beam exposure of the material layer during the manufacturing method of the optical waveguide provided by an embodiment of the present application.
  • the material layer Before double-beam exposure, the material layer is shown on the left in Figure 97.
  • the material layer includes polymers, monomers and nanoparticles. The polymers and monomers are randomly arranged, and the nanoparticles are dispersed. between polymers and monomers.
  • the light source of the double-beam exposure process includes two expanded coherent laser beams. The two expanded coherent laser beams interfere with each other to form a sinusoidal light intensity distribution to form a high light intensity area on the material layer.
  • the energy absorbed by the photoinitiating system in the high light intensity area is more than the energy absorbed by the photoinitiating system in the low light intensity area, so that the active material in the high light intensity area is more than the
  • the active material in the low light intensity area is used to separate the high molecular polymer and the sub-high molecular polymer.
  • the high molecular polymer and nanoparticles are in the direction indicated by the arrow. move. In this way, an interphase distribution structure of the high refractive index phase region and the low refractive index phase region will be formed.
  • the polymer and the monomer phase separate to form a refractive index n1.
  • the angle between the two beams in the double-beam exposure process is a first angle, and the first angle range is: 10 degrees to 180 degrees.
  • the angle between the two beams is 120 degrees.
  • This solution limits the angle range between the two beams in the double-beam exposure process, and can obtain a structure in which the high-refractive index phase zone and the low-refractive index phase zone are parallel and stacked.
  • the vector direction of the anti-reflection layer can be understood as high refractive index
  • the stacking direction of the high-refractive index phase region and the low-refractive index phase region can also be a direction perpendicular to the surface of the waveguide substrate.
  • the manufacturing method of the optical waveguide further includes manufacturing a grating structure through a double-beam exposure process, and forming the grating structure by exposing the double-beam with an included angle of a second angle, and the second angle is different from the first angle. to form different vector directions.
  • the grating structure and at least part of the antireflection layer may be located at the same location on the substrate.
  • the grating structure can be a coupling grating, a coupling grating or a relay grating of an optical waveguide.
  • the type of grating structure is volume holographic grating.
  • the optical waveguide provided by this application is made of an anti-reflection layer based on holographic materials.
  • the structure of the anti-reflection layer is a material with high and low refractive index distributed alternately.
  • the high and low refractive index phase areas are filled with volume holographic materials, and the high refractive index components are filled to high
  • the refractive index phase area is filled with low refractive index components into the low refractive index phase area.
  • the refractive index modulation of volume holographic materials is as high as 0.2.
  • increasing the refractive index modulation degree helps increase the FOV of AR glasses.
  • AR glasses with an FOV of up to 40° can be prepared.
  • the included angle of the double-beam exposure is 120°, and the number of exposures is 1, forming an anti-reflection layer structure in which high refractive index phase areas and low refractive index phase areas are alternately distributed.
  • Each high refractive index phase area or The thickness of each low refractive index phase region is 200nm.
  • the anti-reflection layer can reduce the haze of volume holographic materials and improve the optical performance of optical waveguides.
  • the FOV of the incident light of the optical waveguide is 40°, the light uniformity is 0.3, the haze is 0.5%, and the transmittance range is 80%-100%, for example, the transmittance is 95%.
  • Option 8 Filling layer protects the grating structure
  • the optical waveguide provided in this application is a media device that guides light waves to propagate in it. Its thinness and high penetration of external light are considered to be a necessary solution for near-eye display devices (such as augmented reality (AR) glasses).
  • Optical waveguides can generally be divided into two categories: geometric optical waveguides and diffractive optical waveguides. Geometric optical waveguides are also called array optical waveguides. They achieve image output and eye movement frame expansion through array mirror stacking. Diffractive optical waveguides can be divided into Surface relief grating waveguides and volume holographic grating waveguides. In near-eye display devices, optical waveguides with surface relief gratings are widely used.
  • the optical waveguide 10A includes a waveguide substrate 19 and a cover plate 15.
  • the waveguide substrate 19 has a grating structure 14.
  • the grating structure 14 can be a coupling grating, a coupling grating or a relay grating.
  • the cover plate 15 is used to shield the waveguide base 19 and the grating structure 14.
  • the cover plate 15 is the outermost structure of the optical waveguide 10A.
  • the cover plate 15 can be made of glass.
  • the waveguide base 19 and the cover plate 15 are stacked and need to be connected.
  • the waveguide base 19 and the cover plate 15 are fixedly connected through an adhesive dispensing structure 154 (adhesive).
  • the height of the dispensing structure 154 is about tens of microns.
  • One embodiment of the present application provides a filling layer around the grating structure on the waveguide substrate, and uses the filling layer to protect the grating structure and the waveguide substrate, thereby protecting the optical waveguide and improving the life and optical performance of the optical waveguide.
  • the optical waveguide 10A includes a first waveguide substrate 19S1, a first grating structure 14S1 and a first filling layer 15S1.
  • the first grating structure 14S1 is formed on the surface of the first waveguide substrate 19S1
  • the first filling layer 15S1 is formed on the surface of the first waveguide substrate 19S1.
  • the layer 15S1 and the first waveguide substrate 19S1 are stacked.
  • the first filling layer 15S1 covers the surface of the first waveguide substrate 19S1.
  • the first filling layer 15S1 and the first waveguide substrate 19S1 together form a closed surrounding structure 19C, a first grating structure.
  • the 14S1 is located within the surrounding structure 19C to isolate the first grating structure 14S1 from the external air surrounding the structure 19C.
  • the difference between the refractive index of the first filling layer 15S1 and the refractive index of the air is less than or equal to 0.2.
  • the first waveguide substrate 19S1 can be made of inorganic materials, high-refractive resin materials, etc. This application does not limit the specific material of the first waveguide substrate 19S1.
  • the first waveguide substrate 19S1 can be any material or combination of materials that can achieve total reflection propagation of light. .
  • the first filling layer 15S1 is made of a transparent material and has good light transmittance.
  • the light transmittance can be greater than or equal to 80%.
  • the first filling layer 15S1 may be a material with a low refractive index. The low refractive index is reflected in the fact that the refractive index of the first filling layer 15S1 is close to the refractive index of air.
  • the refractive index of the first filling layer 15S1 is between the refractive index of the air and the refractive index of the air. The difference is less than or equal to 0.2.
  • This solution realizes the protection of the first waveguide substrate 19S1 and the first grating structure 14S1 by setting the first filling layer 15S1, so that the first waveguide substrate 19S1 and the first grating structure 14S1 are isolated from the outside air and can ensure the first waveguide substrate 19S1 and the first grating structure 14S1 avoid long-term contact with water and oxygen environment, solve the problems of easy aging, corrosion and atomization of the optical waveguide 10A, and can also resist external impact force to avoid damage to the optical waveguide.
  • the implementation provided by this application can ensure that the optical waveguide 10A lifespan and optical performance.
  • a cover plate may not be provided outside the first filling layer 15S1 , that is to say, the first filling layer 15S1 may serve as the outermost layer structure of the optical waveguide 10A.
  • the first filling layer 15S1 can fully cover the surface of the first waveguide substrate.
  • the first grating structure 14S1 may be a blazed grating, a straight grating, a tilted grating or a volume holographic grating.
  • the first grating structure 14S1 may be a coupling grating, a coupling grating or a relay grating.
  • the optical waveguide 10A includes a first cover plate 15A, a first waveguide substrate 19S1 and a first filling layer 15S1.
  • the first grating structure 14S1 is formed on the first waveguide substrate 19S1.
  • the first filling layer 15S1 is disposed between the first cover plate 15A and the first waveguide substrate 19S1.
  • the first filling layer 15S1 and the first waveguide substrate 19S1 together form a closed surrounding structure 19C.
  • the first grating structure 14S1 is located within the surrounding structure 19C. To isolate the first grating structure 14S1 from the external air surrounding the structure 19C, the difference between the refractive index of the first filling layer 15S1 and the refractive index of the air is less than or equal to 0.2.
  • This solution provides an optical waveguide structure with a first cover plate, which is filled between the first cover plate and the first waveguide base by a first filling layer, so that there is no air gap between the first cover plate and the first waveguide base.
  • the first filling layer provides supporting force to the first cover plate and can prevent the first cover plate from being damaged by external applications.
  • the first cover plate 15A and the first waveguide base 19S1 are fixedly connected, and the surface of the first filling layer 15S1 facing away from the first waveguide base 19S1 is attached to the inner surface of the first cover plate 15A.
  • the embodiment shown in Fig. 100 has an added structure of the first cover plate 15A.
  • the thickness of the first filling layer 15S1 in the embodiment shown in Fig. 100 can be thinner, as long as Just fill the gap between the first cover plate 15A and the first waveguide base 19S1.
  • This solution provides a fixing solution between the first cover plate and the first waveguide base.
  • the glue-dispensing fixation structure is easy to operate.
  • the glue will not damage the first waveguide base.
  • the optical properties of the first waveguide substrate have destructive effects.
  • the first cover plate 15A and the first waveguide substrate 19S1 are fixedly connected through a glue dispensing structure 154, and the glue dispensing structure 154 is distributed around the first filling layer 15S1.
  • the glue dispensing structure 154 forms a closed structure surrounding the first filling layer 15S1 on the periphery of the first filling layer 15S1, and the glue dispensing structure 154 constitutes a sealing structure on the periphery of the first filling layer 15S1.
  • the dispensing structure 154 is a plurality of spaced connection structures and is arranged in sequence around the first filling layer 15S1.
  • first cover plate 15A and the first waveguide base 19S1 may also be connected through other fixing methods, such as screw fixation.
  • the surface of the first waveguide substrate 19S1 is planar, and the first grating structure 14S1 protrudes from the surface of the first waveguide substrate 19S1 .
  • the first filling layer 15S1 surrounds the top surface and side surfaces of the first grating structure 14S1, and the bottom surface of the first grating structure 14S1 is connected to the first waveguide substrate 19S1.
  • the first grating structure 14S1 can also be embedded in the first waveguide substrate 19S1.
  • the bottom surface and side surfaces of the first grating structure 14S1 are located inside the first waveguide substrate 19S1 , and the first filling layer 15S1 covers the top surface of the first grating structure 14S1 and the outer surface of the first waveguide substrate 19S1 .
  • the first filling layer 15S1 covers the top surface of the first grating structure 14S1 and the outer surface of the first waveguide substrate 19S1 .
  • the top surface of the first grating structure 14S1 may be concave compared to the outer surface of the first waveguide substrate 19S1 , so that part of the first filling layer 15S1 is located in the first waveguide. within the groove formed by base 19S1.
  • this embodiment can use a smaller amount of adhesive to fix the first waveguide substrate 19S1 and the first cover plate 15A.
  • the small size design of the dispensing structure 154 is beneficial to reducing the impact of the dispensing structure on the first waveguide substrate 19S1. It can be understood that the adhesive penetrating into the first waveguide substrate 19S1 affects the refractive index of the first waveguide substrate 19S1.
  • FIGS. 99 to 101 the arrangement of the first grating structure 14S1 on the first waveguide substrate 19S1 and the positional relationship between the first grating structure 14S1 and the first filling layer 15S1 are schematically expressed.
  • the microstructure in the first grating structure 14S1 is not drawn in detail.
  • Figures 102 and 103 schematically describe the positional relationship between the microstructures in the first grating structure 14S1 and the first filling layer 15S1.
  • the first filling layer 15S1 includes a grating contact surface 15S11, and the grating contact surface 15S11 is planar.
  • the first grating structure 14S1 includes periodically arranged microstructures 14S11. There are periodically arranged slits 14S12 between the grating contact surface 15S11 and the first grating structure 14S1.
  • the periodically arranged slits 14S12 can be understood as the first grating structure 14S1.
  • the dimensions of the microstructure 14S11 and the slit 14S12 are nanoscale units, which are used to form a diffraction grating structure.
  • This solution allows a slit to exist between the grating contact surface 15S11 and the surface of the first grating structure 14S1.
  • the manufacturing process of the first filling layer 15S1 provided by this solution has low precision requirements and is easy to manufacture.

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Abstract

本申请提供了一种合光单元、光学组件、光机、光波导、近眼显示设备及光波导的制作方法。通过合光单元四个棱镜单元的设计,使得光学组件中发光单元的布置方案更灵活,有利于近眼显示设备和光机的结构紧凑。通过对光波导的具体的结构设计能够提升光波导的衍射效率、提升图像显示效果、解决鬼像问题、使得近眼显示设计具有轻量化等优势,本申请还提供一种具有柔性的光波导。采用本申请提供的光波导的制作方法能够提高制作过程脱模的可靠性,能够提升光波导的结构稳定性,且提升光学减反的功能。

Description

光波导结构及其制作方法、光学组件和近眼显示设备
本申请要求于2022年09月08日提交中国专利局、申请号为202211092291.2、申请名称为“一种增强现实设备及其显示方法”的中国专利申请的优先权,2022年12月30日提交中国专利局、申请号为202211731720.6、申请名称为“光波导结构及其制作方法、光学组件和近眼显示设备”的中国专利申请的优先权,其全部内容通过引用结合在本申请中。
技术领域
本申请涉及光学显示技术领域,尤其涉及一种光波导结构及其制作方法、光学组件和近眼显示设备,其中,光波导结构可以为光栅结构、耦出光栅、具有光栅结构的光波导结构等等,光学组件可以为光机、合光单元、具有光机与合光单元的光学组件等等。
背景技术
近眼显示(near-to-eye display),也称头戴显示或可穿戴显示,可在单眼或双眼视场中创建虚像,近眼显示通过置于人眼非明视距离内的显示设备,向人眼渲染出光场信息,进而在眼前重建虚拟场景的技术。
增强现实(augmented reality,AR)技术是一种将真实世界信息和虚拟世界信息“无缝”集成的新技术,是把原本在现实世界的一定时间空间范围内很难体验到的实体信息(如:视觉信息,三维形貌,声音,味道,触觉等),通过光学、计算机、电子等,模拟仿真后再叠加,不仅展现了真实世界的信息,而且将虚拟的信息同时显示出来,两种信息相互补充、叠加。在视觉化的增强现实中,用户利用光学显示装置,把真实世界与虚拟图像结合在一起,形成虚实结合的沉浸式视觉体验。
将AR技术应用在近眼显示设备中,产生了AR眼镜,AR可以实现诸多功能,可以看作是一台微型的手机,通过跟踪眼球视线轨迹判断用户处于的状态,并且可以开启相应功能。近眼显示技术产品(例如AR眼镜)正在朝着更轻、更薄、更便携的方向发展,同时对近眼显示设备所渲染的内容也要求更加舒适、更加真实、更加流畅。因此,对于近眼显示设备而言,行业设计发展的趋势为:轻量化的设计、薄型小尺寸的设计、提升光学显示效果等。
发明内容
本申请提供了一种光波导结构及其制作方法、光学组件和近眼显示设备,其中,光波导结构可以为光栅结构、耦出光栅、具有光栅结构的光波导结构等等,光学组件可以为光机、合光单元、具有光机与合光单元的光学组件等等,能够实现近眼显示设备的轻量化、薄型小尺寸、及提升光学显示效果。
第一方面,本申请具体实施方式提供一种合光单元,用于近眼显示设备的光机中,所述合光单元包括第一棱镜单元、第二棱镜单元、第三棱镜单元和第四棱镜单元,所述第一棱镜单元和所述第三棱镜单元为五面体结构,所述第二棱镜单元和所述第四棱镜单元为四面体结构,所述第一棱镜单元、所述第二棱镜单元、所述第三棱镜单元和所述第四棱镜单元拼接形成六面体架构,所述第一棱镜单元和所述第二棱镜单元之间对接的位置为第一面,所述第三棱镜单元和所述第四棱镜单元之间的对接位置为第二面,所述第一棱镜单元和所述第四棱镜单元之间对接的位置为第三面,所述第二棱镜单元和所述第三棱镜单元之间的对接位置为第四面,所述第一面和所述第二面设置第一分光膜,所述第三面和所述第四面设置第二分光膜,所述第一分光膜和所述第二分光膜反射的光线的波长范围不同,所述第一面和所述第二面构成所述六面体架构的第一对角面,所述第三面和所述第四面构成所述六面体结构的第二对角面,所述第一对角面和所述第二对角面之间的相交线为所述六面体结构的体对角线。
本申请通过将合光单元中的四个棱镜单元中的第一棱镜单元和第三棱镜单元设计为五面体结构,将四个棱镜单元中的第二棱镜单元和第四棱镜单元设计为四面体结构,这四个棱镜单元拼接能形成六面体架构,通过在第一对角面和第二对角面上设置分光膜,而且第一对角面和第二对角面之间的相交线为所述六面体结构的体对角线,使得合光单元能够更灵活地匹配发光单元,即发光单元的各显示屏的摆放方案更多,更灵活,可以根据具体的使用环境的需求采用合适的摆放方案,有利于近眼显示设备的光机结构紧凑,特别是光机中的柔性电路板可以沿着近眼显示设备的结构件延伸布置,不需要弯折,能够节约空间。
一种可能的实现方式中,所述第一棱镜单元、所述第二棱镜单元、所述第三棱镜单元和所述第四棱镜单元均为一体式棱镜结构。本实施方式提供一种由四块棱镜构成的合光单元,具有结构简洁,且与发光单 元配置仍具灵活性的优势。
一种可能的实现方式中,所述第一分光膜用于反射第一波长范围的光且透射第二波长范围的光及第三波长范围的光,所述第二分光膜用于反射第二波长范围的光且透射第一波长范围的光及第三波长范围的光。本方案限定了在由四块棱镜构成的合光单元中的一种分光膜的配置方案,通过分光膜的配置,影响发光单元的配置,使得合光单元和发光单元结合后的交机能够具有结构紧凑、节约空间的优势。
一种可能的实现方式中,所述第一分光膜用于反射第二波长范围的光且透射第一波长范围的光及第三波长范围的光,所述第二分光膜为用于反射第一波长范围的光且透射第二波长范围的光及第三波长范围的光。本方案限定了在由四块棱镜构成的合光单元中的一种分光膜的配置方案,通过分光膜的配置,影响发光单元的配置,使得合光单元和发光单元结合后的交机能够具有结构紧凑、节约空间的优势。
一种可能的实现方式中,所述第一棱镜单元包括第一子棱镜和第二子棱镜,所述第一子棱镜和所述第二子棱镜之间对接的位置为第一子面;所述第二棱镜单元包括第三子棱镜和第四子棱镜,所述第三子棱镜和所述第四子棱镜之间对接的位置为第二子面;所述第三棱镜单元包括第五子棱镜和第六子棱镜,所述第五子棱镜和所述第六子棱镜之间对接的位置为第三子面;所述第四棱镜单元包括第七子棱镜和第八子棱镜,所述第七子棱镜和所述第八子棱镜之间对接的位置为第四子面;所述第一子面、所述第二子面、所述第三子面和所述第四子面构成所述六面体结构的第三对角面,所述第三对角面和所述第一对角面之间的相交线为所述六面体结构的体对角线,所述第三对角面和所述第二对角面之间的相交线的长度等于所述六面体结构的棱长。本实施方式提供一种由八块棱镜构成的合光单元,相较四块棱镜架构,本方案具有更灵活地与发光单元搭配的方案,本方案能够实现更多的发光单元的配置,使得光机的应用方案更多,可以根据具体的设计需求,选择合适的发光单元的配置方案,灵活性更好。
一种可能的实现方式中,所述第一子棱镜和所述第二子棱镜均为五面体棱镜;所述第三子棱镜和所述第四子棱镜中的一个为四面体棱镜,另一个为五面体棱镜;所述第五子棱镜和所述第六子棱镜均为五面体棱镜;所述第七子棱镜和所述第八子棱镜中的一个为四面体棱镜,另一个为五面体棱镜。本方案限定了由八块棱镜构成的合光单元中的各棱镜的具体的形态,本申请通过不同形态的棱镜的设置,使得合光单元具有灵活布置发光单元的优势。
一种可能的实现方式中,所述第三对角面设有第三分光膜,所述第三分光膜、所述第一分光膜和所述第二分光膜分别用于反射不同波长范围的光线。本方案限定了由八块棱镜构成的合光单元中分光膜的设置方案,通过三个分光膜的设置,且三个分光膜分别用于反射不同波长范围的光线,使得合光单元具有灵活的布置发光单元的优势。
一种可能的实现方式中,所述第二分光膜和所述第三分光膜均包括四个子膜,所述第一分光膜为一体式的结构。本方案限定了第二分光膜和第三分光膜的具体的结构,及第一分光膜为一体式结构的方案,本方案设计的分光膜应用在由八块棱镜构成的合光单元中,由于第一分光膜可以为一体式结构,具有结构简洁,组装方便的优势。
一种可能的实现方式中,所述第二分光膜包括两个子膜,所述第一分光膜为一体式的结构。本方案设计的分光膜应用在由四块棱镜构成的合光单元中,由于第一分光膜可以为一体式结构,具有结构简洁,组装方便的优势。
一种可能的实现方式中,所述第一分光膜为反绿透红蓝膜层,所述第二分光膜为反蓝透红绿膜层,所述第三分光膜为反红透蓝绿膜层。本方案具体限定一种三个分光膜的具体配置方案。
一种可能的实现方式中,所述六面体结构为立方体。立方体结构的设计,使得发光单元中不同颜色的光源(即第一波长范围发射单元、第二波长范围发射单元和第三波长范围发射单元)从入光面至出光面的光程可以保持一致,即第一波长范围发射单元所发出的红色光线、第二波长范围发射单元所发出的蓝色光线及第三波长范围发射单元所发出的绿色光线在合光单元内的传输路径的长度是一样的,光的传输路径即光程,光程相同,有利于保证光机成像的清晰度。若某一种颜色的光的光程与其它颜色光的光程不一致,会导致光机投影的图像清晰度不好,图像较模糊。
第二方面,本申请具体实施例提供一种光机,包括发光单元、光学成像单元和第一方向任意一种可能的实施方式提供的合光单元,所述合光单元用于将发光单元发出的单色光进行合光,所述光学成像单元位于所述合光单元的出光侧。本申请提供的光机,由于包括第一方面所述的合光单元,使得光机具有更灵活的配置方案,使光机可以配置在近眼显示设备中更多的环境。光机的结构可以更紧凑,有利于节约空间。
一种可能的实现方式中,所述发光单元包括第一波长范围发射单元、第二波长范围发射单元和第三波 长范围发射单元,所述第一波长范围发射单元正对所述合光单元的所述六面体结构的第一入光面,所述第二波长范围发射单元正对所述合光单元的所述六面体结构的第二入光面,所述第三波长范围发射单元正对所述合光单元的所述六面体结构的第三入光面,所述第一入光面、所述第二入光面和所述第三入光面两两相互垂直相邻设置,所述第一波长范围发射单元的发光面的法线方向和所述第二波长范围发射单元的发光面的法线方向均垂直于所述光机的所述光学成像单元的光轴,所述第三波长范围发射单元的发光面的法线方向与所述光机的所述光学成像单元的光轴方向相同。本方案提供了一种具体的发光单元和合光单元的各入光面对应设置的方案。
一种可能的实现方式中,所述发光单元包括第一波长范围发射单元、第二波长范围发射单元和第三波长范围发射单元,所述第一波长范围发射单元的发光面正对所述合光单元的所述六面体结构的第一入光面,所述第二波长范围发射单元的发光面正对所述合光单元的所述六面体结构的第二入光面,所述第三波长范围发射单元的发光面正对所述合光单元的所述六面体结构的第三入光面,所述第一入光面和所述第二入光面相互平行,所述第三入光面垂直于所述第一入光面,所述第一波长范围发射单元的发光面的法线方向、所述第三波长范围发射单元的发光面的法线方向和所述第二波长范围发射单元的发光面的法线方向均垂直于所述光机的所述光学成像单元的光轴。本方案提供了另一种具体的发光单元和合光单元的各入光面对应设置的方案。
一种可能的实现方式中,合光单元的入光面的面积大于对应的发光单元的发光面的面积,这样可以保证发光单元发出的光线更多地进入合光单元,提升光线传输的效率。
第三方面,本申请具体实施例提供一种近眼显示设备,包括结构件和镜片,所述结构件包括镜腿和镜框,所述镜腿连接于所述镜框,所述镜片具有光波导,所述镜片固定在所述镜框上,所述近眼显示设备包括第二方面任意一种可能的实施方式提供的光机,所述光机固定至所述结构件。本方案提供一种近眼显示设备,由于包括第二方面所述的光机,使得近眼显示设备具有更多的设计方案,光机的位置布置灵活。而且由于光机的结构可以更紧凑,有利于节约空间,小利于近眼显示设备的尺寸小型化。
一种可能的实现方式中,所述近眼显示设备设有控制器,所述发光单元包括第一柔性电路板、第二柔性电路板和第三柔性电路板,所述第一柔性电路板电连接在所述第一波长范围发射单元和所述控制器之间,所述第二柔性电路板电连接在所述第二波长范围发射单元和所述控制器之间,所述第三柔性电路板电连接在所述第三波长范围发射单元和所述控制器之间,所述第一柔性电路板、所述第二柔性电路板和所述第三柔性电路板中的至少一个无弯折状顺着所述结构件延伸。本方案提供的近眼显示设备中,光机的柔性电路板中的至少一个不需要折叠,即无弯折状顺着结构件延伸,有利于整机尺寸的减小。可以理解的是,若将柔性电路板折叠,光机整体的尺寸会因柔性电路板的折叠变大,在近眼显示设备中,就会占用更大的空间。
一种可能的实现方式中,所述光机固定至所述镜腿,所述第一柔性电路板、所述第二柔性电路板和所述第三柔性电路板中的至少一个无弯折状顺着所述镜腿延伸,所述合光单元的所述六面体结构中的一个外表面为非入光表面,所述非入光表面邻接所述合光单元的出光面,所述非入光表面朝向所述镜腿的内侧,所述镜腿的内侧用于贴近人脸。这样的设置也能够保证近眼显示设备在靠近有脸的一侧不设置发光单元,降低用户感知到热的风险,提升用户使用的体验感。
第四方面,本申请提供的一种光学组件包括光机和光波导,所述光波导包括波导基底和耦入光栅,所述波导基底包括斜面,所述斜面位于所述耦入光栅和所述波导基底结合的位置或者位于所述耦入光栅和所述波导基底结合位置的入光侧,所述耦入光栅用于接收所述光机的光,所述斜面朝向所述光机,所述光机具有光轴,与所述光轴垂直的方向为第一方向,所述斜面和所述第一方向之间的夹角大于等于所述光机的视场角的二分之一,以使所述耦入光栅反射的所述光机的视场角的边缘光线能够偏出所述光机。本申请提供的光学组件,通过光波导的结构设计,具体而言,通过光波导的入光位置的设计,使得耦入光栅位置反射的光线偏离光机,即,耦入光栅位置反射的光线的方向会位于光机的光学有效区之外,不会返回至光机内,这样使得光学组件能获得较好的图像显示效率,解决了鬼像的问题。具体而言,通过在波导基底上设置斜面,斜面和第一方向夹角大于等于所述光机的视场角的二分之一,以使所述耦入光栅反射的所述光机的视场角的边缘光线能够偏出所述光机。
一种可能的实现方式中,所述光机的视场角为水平面视场角或垂直面视场角。本申请限定了光机的视场角可以为水平视场角,也可以为垂直面视场角,在计算斜面的角度时候可以采用任意一种视场角来获得合适的角度。体现了本方案设计较为灵活的一面。
一种可能的实现方式中,所述光机的光轴为所述光机的有效光学区的中心轴。可以理解为,本方案提 供的光机为非离轴光轴系统,光学有效区的中心轴为光轴,为光机的设计提供了便利性。
一种可能的实现方式中,所述波导基底为一体成型结构,所述斜面为通过在所述波导基底上去除部分材料形成的结构。本方案限定一种具体的斜面形成方式,通过对波导基底去除部分材料形成斜面,易于保证斜面位置处的折射率的稳定性,即在斜面形成过程中,不容易改变波导基底的折射率,从而能够保证耦入光栅的衍射效率,保证耦入光线不会产生不需要的偏折,保证形成的虚拟图像的真实性,不产生扭曲。
一种可能的实现方式中,所述耦入光栅形成在所述斜面上,经所述耦入光栅反射的光线与所述光轴之间的夹角为第二角度,入射在所述耦入光栅上的所述光机的视场角的边缘光线与所述光轴之间的夹角为第一角度,所述第二角度大于所述第一角度。本方案限定了一种通过去除材料的方式得到的斜面的方案,限定了耦入光栅位于斜面上的具体的方案。本方案通过斜面和耦入光栅的设置,使得耦入光栅的设置的角度与波导基底的主平面之间形成倾斜状态,这样,入射在耦入光栅上的部分光线反射,反射光线直接偏离光机,本实施方式提供的光学组件不存在耦出光栅的反射光线进入光机后再一次反射形成鬼像的现象。
一种可能的实现方式中,所述波导基底包括主平面,所述斜面相对所述主平面倾斜,所述耦入光栅形成在所述主平面上,在所述光轴的延伸方向上,所述斜面位于所述耦入光栅和所述光机之间,所述光机的视场角的边缘光线经过所述斜面入射在所述耦入光栅上,经所述耦入光栅反射的所述光机的视场角的边缘光线经过所述斜面偏出所述光机。本方案限定了一种通过去除材料的方式得到的斜面的方案,限定了耦入光栅位于波导基底的主平面上的方案。由于斜面的相对耦入光栅所在的主平面倾斜设置,从斜面进入光波导后投射在耦入光栅上的光线,在斜面位置发生折射,这样可以保证在耦入光栅位置反射的耦入光栅反射光线会偏出光机。因此,本实施方式提供的光学组件不存在耦出光栅的反射光线进入光机后再一次反射形成鬼像的现象。
本申请通过将耦入光栅形成在波导基底的主平面上,由于主平面为波导基底的整体的平面状的外表面,对于耦入光栅的制作工艺,具有易于制作优势,对于设计及工艺步骤均具有优势。而将耦入光栅制作在斜面上的实施方式,虽然制作工艺方面有所挑战,但是耦入光栅和光机之间的光路相对更简洁,易于控制光传输效率。
一种可能的实现方式中,所述波导基底包括波导主体结构和附加结构,所述附加结构固定至所述波导主体结构的面对所述光机的表面,所述斜面形成在所述附加结构上,所述斜面位于所述附加结构背离所述波导主体结构的表面。本方案通过在波导基底上增加附加结构,通过附加结构形成斜面,本方案具有保护波导基底结构完整性的优势,波导基底的结构完整性有利于保证波导基底的寿命,未经切除部分结构的波导基底,强度和稳定性更好,结构稳定性好的光波导,光传输效率就相对稳定,本方案有利于保证光波导的寿命和光传输效率。
一种可能的实现方式中,所述耦入光栅形成在所述斜面上,从所述耦入光栅入射的光线经过所述附加结构后进入所述波导主体结构,经所述耦入光栅反射的光线与所述光轴之间的夹角为第二角度,入射在所述耦入光栅上的所述光机的视场角的边缘光线与所述光轴之间的夹角为第一角度,所述第二角度大于所述第一角度。本方案限定了设置附加结构与波导基底结合的方案中,耦入光栅的具体的位置的一种方案,本方案将耦入光栅设置在斜面上。使得耦入光栅的入射光的光路简洁,入射光的能量易于控制,有利于提升光效。
一种可能的实现方式中,所述波导主体结构包括主平面,所述斜面相对所述主平面倾斜,所述耦入光栅形成在所述主平面上,在所述光轴的延伸方向上,所述斜面位于所述耦入光栅和所述光机之间,所述光机的视场角的边缘光线经过所述斜面进入所述附加结构和所述波主导体结构且入射在所述耦入光栅上,经所述耦入光栅反射的所述光机的视场角的边缘光线经过所述波导主体结构和所述附加结构且从所述斜面射出且偏出所述光机。本方案限定了设置附加结构与波导基底结合的方案中,耦入光栅的具体的位置的一种方案,本方案将耦入光栅设置在波导基底的主平面上,由于主平面为波导基底的整体的平面状的外表面,对于耦入光栅的制作工艺,具有易于制作优势,对于设计及工艺步骤均具有优势。
一种可能的实现方式中,所述附加结构的材料与所述波导主体结构的材料相同。本方案通过限定材料相同,可以得到折射率与波导主体结构相同或相近的附加结构,以保证入射至波导基底的光线在附加结构和波导主体结构中的传输具有一致性,避免因折射率不同导致光线偏折影响衍射效率或无法得到需要的入射光的角度,因此,本申请通过限定附加结构的折射率和材质与波导基底一致,能够保证光波导的光学性能。
一种可能的实现方式中,所述附加结构的折射率与所述波导主体结构的折射率相同。具体而言,附加结构可以为高折衬底材料。通过对附加结构的折射率限定为与波导主体结构的折射率相同或近似,能够保 证入射至波导基底的光线在附加结构和波导主体结构中的传输具有一致性,避免因折射率不同导致光线偏折影响衍射效率或无法得到需要的入射光的角度。
本申请所定义的折射率相同,其中的“相同”,可以理解为完全相同,可存在较小的公差,也可以理解为近似相同,只要使得入射光的角度在设计需求范围内即可。
一种可能的实现方式中,所述附加结构和所述波导主体结构之间通过光学胶水粘合,所述光学胶水的折射率和所述附加结构及所述波导主体结构的折射率相同。本方案限定了种附加结构和波导主体结构之间连接的具体方式,且约束光学胶水的折射率,使得光波导的波导基底的折射率具有一致性,避免因折射率不同导致光线偏折影响衍射效率或无法得到需要的入射光的角度。
一种可能的实现方式中,附加结构上的斜面的位置抛光处理,以提升光的透过率。
一种可能的实现方式中,所述附加结构和所述波导主体结构之间通过分子间键合方式结合。本方案限定了种附加结构和波导主体结构之间连接的具体方式,通过分子键合的方式结合,可以避免使用其它介质连接,例如光学胶水,本方案获得的附加结构和波导主体结构之间的结合更直接,有利于保证光波导基底的折射率具有一致性,避免因折射率不同导致光线偏折影响衍射效率或无法得到需要的入射光的角度。
第五方面,本申请提供一种近眼显示设备,包括结构件和第四方面任意一种可能的实施方式提供的所述光学组件,所述光学组件安装于所述结构件。本方案提供的近眼显示设备,因光学组件的设计,解决了鬼像的问题,获得优势的图像显示效果。
本申请第四方面提供的光学组件中的光机也可以包括本申请第一方面任意一种可能的实现方式提供的合光单元。
本申请第四方面提供的光学组件中的光机也为本申请第二方面任意一种可能的实现方式提供的光机。
本申请第五方面提供的近眼显示设备可以包括:本申请第一方面任意一种可能的实现方式提供的合光单元,和/或,本申请第二方面任意一种可能的实现方式提供的光机。
本申请第三方面提供的近眼显示设备可以包括本申请第四方面任意一种可能的实现方式提供的光学组件。
第六方面,本申请提供一种光波导,能够解决光线浪费和光线不均匀的问题。光波导包括耦入光栅和耦出光栅,所述耦入光栅用于将光线耦入所述光波导并在所述光波导内进行全反射,所述耦出光栅用于将光线耦出,所述耦出光栅包括第一区域和第二区域,沿第一方向,所述第一区域位于所述第二区域的入光侧,所述第一区域包括第一子区域和第二子区域,所述第一子区域和所述第二子区域沿第二方向排列,所述第二方向和所述第一方向相交,所述第一子区域和所述第二子区域内的光栅类型均为一维光栅,所述第二区域用于耦出光线,所述第二区域中至少部分光栅的光栅类型为二维光栅,所述第二区域的中轴线的延伸并穿过所述耦入光栅,所述第一子区域和所述第二子区域分布在所述中轴线的两侧。本申请通过第一区域中的一维光栅使得光线大部分能量均被传送至第二区域,能够提升光传播的效率,提升光的均匀性,而且可以降低加工制作的难度,降低成本。
一种可能的实现方式中,所述第一子区域、所述第二子区域均和所述第二区域接触。也可以理解为,第一子区域、第二子区域均和第二区域之间无任何间隙,通过连续制作第二区域,使得第二区域的光栅具有连续性,能够提升光线耦出效率。
一种可能的实现方式中,所述第一子区域和所述第二区域之间形成第一间隔区域,所述第二子区域和所述第二区域之间形成第二间隔区域,所述第一间隔区和所述第二间隔区内均无光栅结构。本方案有利于保证在制作耦出光栅的过程中,提升制作良率及效率。
一种可能的实现方式中,所述第一间隔区域沿所述第一方向延伸的尺寸小于等于4毫米,所述第二间隔区域沿所述第一方向延伸的尺寸小于等于4毫米。本方案限定第一间隔区域和第二间隔区域沿第一方向的尺寸,有利于保证光线的利用率,及耦出光线的强度。
一种可能的实现方式中,所述耦入光栅的中心位于所述第二区域的中轴线上。本方案限制了第二区域的中轴线的与耦入光栅之间的有关系,即第二区域的中心和耦入光栅的中心之间的连线可以认为是中轴线。
一种可能的实现方式中,所述第一子区域和所述第二子区域以所述中轴线为中心呈镜相对称分布。本方案通过约束所述第一子区域和所述第二子区域与中轴线之间的关系,通过镜相对称的设计,使得耦出光栅的第二区域的光的能量更均衡。
一种可能的实现方式中,所述第一子区域和所述第二子区域的面积不同。本方案可以根据具体的需求调节第一子区域和第二子区域的具体的尺寸和形态,使得光波导具有更广泛的应用场景。
一种可能的实现方式中,所述第一子区域的中心和所述第二子区域的中心之间的连线方向为所述第二 方向,所述第二方向和所述中轴线之间的夹角小于90度。本实施方式,因着耦入光栅位置的调整,使得第一区域中的第一子区域和第二子区域具体的结构形态发生变化,但是,第一子区域和第二子区域仍然能够实现约束光束的传播方向,提升光传播效率的作用。
一种可能的实现方式中,所述第一子区域内的一维光栅的栅线延伸方向为第一栅线方向,所述第二子区域内的一维光栅的栅线延伸方向为第二栅线方向,所述第二区域内的二维光栅包括相交设置的第一栅线和第二栅线,所述第一栅线的延伸方向为所述第一栅线方向,所述第二栅线的延伸方向为第二栅线方向。本申请通过第一栅线的延伸方向与第一栅线方向大致相同,所述第二栅线的延伸方向和第二栅线方向大致相同的设置,使得光波导传送的图像信息具有真实性,不会产生图像的扭曲,保证图像显示效果。
一种可能的实现方式中,所述第一子区域内的一维光栅的分布周期与所述第一栅线的分布周期相同;和/或,所述第二子区域内的一维光栅的分布周期与所述第二栅线的分布周期相同。本方案通过约束第一子区域中的一维光栅的周期和第二区域中的第一栅线的周期相同,以及约束第二子区域中的一维光栅的周期和第二区域中的第二栅线的周期相同,可以保证耦出图像不失真,图像不会产生扭曲等不良现象,能够保证图像的显示效果。
一种可能的实现方式中,所述第一栅线方向和所述第二栅线方向之间的夹角为60度。本方案通过第一栅线方向和第二栅线方向之间的夹角为60度,能约束光线的传播方向,使得光线的传播方向匹配第二区域122中二维光栅的栅线方向,这样能够保证光线更多地被耦出,能够得到较高的光效。
一种可能的实现方式中,所述第一子区域和所述第二子区域接触。本方案提供的第一区域中,第一子区域中的一维光栅和第二子区域中的一维光栅连接,可以提高光传导的效率。
一种可能的实现方式中,所述第一子区域和所述第二子区域之间形成第三间隔区域。本方案通过在第一子区域和第二子区域之间设第三间隔区,有利于保证第一子区域中的一维光栅和第二子区域中的一维光栅的制作过程的简化,不需要精确控制二者邻接位置的光栅结构,只要预留第三间隔区域,就可以保证两个了区域中的一维光栅制作的更容易,节约制作和研发的成本。
一种可能的实现方式中,所述第三间隔区域内无光栅结构,所述第三间隔区域沿所述第二方向延伸的尺寸小于等于耦入光栅的最大径向尺寸。本方案通过约束第三间隔区域和耦入光栅最大径向尺寸的关系,使得耦入光栅传送至第三间隔区域位置的光线,仍然可以通过第一子区域和第二子区域中的一维光栅结构传送至第二区域,能够避免更多的光能的浪费。
一种可能的实现方式中,所述第二区域内所有的光栅类型均为二维光栅。本方案提供的第二区域具有结构简洁,易于制作的优势。
一种可能的实现方式中,所述第二区域内包括N个二维区和N-1个一维区,N≥2,N-1个所述一维区分别位于相邻的两个所述二维区之间,其中一个所述二维区邻接或邻近所述第一区域,所述一维区内的光栅类型为一维光栅,所述二维区内的光栅类型为二维光栅。本申请通过在第二区域中设置二维光栅和一维光栅,且将一维光栅设置在二维光栅中间,有利于调控耦出光线的强度,使整个画面均匀性更好。具体而言,在第二区域中,邻近第一区域的部分光线强度大于远离第一区域的部分的光线强度。一维区设置在相邻的二维区之间,一方面,通过一维区中的一维光栅能够减弱一维区位置的光强,另一方面,一维区中的一维光栅能够约束光线传播方向,使光线集中传播至一维区出光侧的二维区中,这样可以将二维区的光强补强,因此,整体而言,能够保证第二区域的耦出光线的强度均匀性。
一种可能的实现方式中,所述一维区包括第三子区域和第四子区域,所述第三子区域和所述第四子区域沿所述第二方向排列且分布在所述中轴线的两侧。本方案提供了一维区的具体的设计,通过第一子区域和第四子区域的设置,使得第二区域具有更好的均光性。
一种可能的实现方式中,所述二维区中的部分光栅的栅线方向和所述第三子区域中的光栅的栅线方向相同,所述二维区中的部分光栅的栅线方向和所述第四子区域中的光栅的栅线方向相同。本方案有利于保证图像的真实性,保证图像的质量,避免图像产生扭曲等不良现象。
第七方面,本申请提供一种近眼显示设备,包括光机和第六方面任意一种可能的实现方式提供的光波导,所述光机位于所述耦入光栅的入光侧。本方案提供的近眼显示设备通过采用第六方面所述的光波导,使得近眼显示设备所产生的虚拟图像的效果更好,光强及光均匀性都得到优化。
本申请第七方面提供的近眼显示设备可以包括如下任意一种方案或方案的组合:本申请第一方面任意一种可能的实现方式提供的合光单元、本申请第二方面任意一种可能的实现方式提供的光机、本申请第四方面提供的光学组件。
本申请第五方面提供的近眼显示设备可以包括:本申请第六方面任意一种可能的实现方式提供的光波 导。
本申请第三方面提供的近眼显示设备可以包括:本申请第六方面任意一种可能的实现方式提供的光波导。
第八方面,本申请提供一种光波导,包括耦出光栅,耦出光栅包括多个子光栅相互间隔排布,相邻的两个所述子光栅的间距为L,3mm≦L≦5mm,L指的是相邻的两个所述子光栅的中心之间的距离,其中一个所述子光栅为第一子光栅,所述第一子光栅与邻近所述第一子光栅的其它所述子光栅之间均设有隔开区域,所述第一子光栅的最大径向尺寸小于等于1.5mm,所述隔开区域无光栅结构。本方案提供的光波导中,通过将耦出光栅设计为多个相互间隔的子光栅,且限制子光栅的最大径向尺寸及相邻的子光栅之间的距离,使得子光栅耦出的光线为细光束,细光束可以理解为,光束的尺寸较小,进入瞳孔光束数量可以只有一束光,以至于光束不会充满瞳孔。细光束进入人眼成像时,景深会变得很大,从而不论使用者聚焦在何处,即可使使用者观察不同视差的虚拟图像时,均能清晰的看到虚拟图像,而不用在意虚拟图像虚像距实际位于何处,从而解决光波导存在的虚像距是固定值的问题,消除VAC问题。
一种可能的实现方式中,所述第一子光栅的最大径向尺寸为D,0.5mm≦D≦1mm。本方案限定了第一子光栅的径向尺寸大于等于0.5mm,可以保证第一子光栅能够具有耦出光栅的功能,即可以将光波导内的光线耦出至人眼,本方案限定第一子光栅的径向尺寸小于等于1mm,可以保证第一子光栅投射出的光线为细光束,即使瞳孔尺寸受环境因素影响变小的情况下,第一子光栅投射至瞳孔的光束仍然是细光束,不能充满瞳孔。
一种可能的实现方式中,所述多个子光栅中的每一个所述子光栅的最大径向尺寸均为D,0.25mm≦D≦0.75mm;或,0.75mm≦D≦1.5mm。本方案限定所有的子光栅均能够耦出细光束,解决VAC问题。针对应用在室外明亮场所的环境,由于人眼瞳孔受环境的影响,会变小,因此,一种实施方式中,子光栅中的每一个所述子光栅的径向尺寸范围较小,具体为:0.25mm≦D≦0.75mm。针对应用在室内较阴暗的环境,由于人眼瞳孔受环境的影响,会变大,因此,一种实施方式中,子光栅中的每一个所述子光栅的径向尺寸范围较大,具体为:0.75mm≦D≦1.5mm。
一种可能的实现方式中,3.5mm≦L≦4.5mm。本实施方式所限定的相邻的两个所述子光栅的间距的范围可以满足多种应用环境和不同的应用场景,更容易保证子光栅所耦出的光线为细光束。
一种可能的实现方式中,所述多个子光栅呈多行多列的阵列排布,所述阵列排布具有相同的行间距和相同的列间距。本方案限定一种具体的子光栅的阵列排布的方案,可以解决VAC问题。
一种可能的实现方式中,所述多个子光栅排列为多行,各行所述子光栅的排列方向为第一方向,多行所述子光栅中的奇数行和偶数行在错位设置,第二方向垂直于第一方向,在第二方向上,所述奇数行的所述子光栅正对所述偶数行的相邻的两个所述子光栅之间的所述隔开区域。本实施方式提供一种蜂窝状的阵列排布方案,具有的好处为:本方案能保证眼动空间位置处各细光束的相对距离为恒定值,而正交阵列排布方案中各细光束间距在斜边方向略大于水平及竖直方向。对于本方案而言,当人眼在眼动空间内发生移动时,如眼睛转动或眼镜发生滑动时,不同的进入人眼瞳孔的细光束会发生变化,由于蜂窝状的排布方式中的各细光栅相对距离恒定,既然人眼相对眼动空间发生位移,进入人眼的光束能量能够保证相等,因此图像的变化也会更加平坦,能够提升近眼显示设备的使用体验感。
一种可能的实现方式中,任意两个邻近设置的所述子光栅之间的间距均相等。通过限制子光栅的间距相等,可以实现耦出光线的均匀性。
一种可能的实现方式中,所述子光栅的外轮廓形状为圆形或正方形或六边形。
一种可能的实现方式中,各所述子光栅包括按预设周期排布的光栅微结构,所述预设周期为200-500nm。光栅微结构的具体形状可以为但不限于:六边形、平行四边形、三角形、梯形等。在子光栅内,因光栅微结构的设置,使得子光栅能够将光波导内的光线耦出,并投射至人眼。
一种可能的实现方式中,多个所述子光栅共面,即多个子光栅设置在波导基底的同一个表面上。本方案具有方便控制子光栅之间的间距的优势,易于获得精确的子光栅的排列。
一种可能的实现方式中,相邻的两个所述子光栅中的一个位于光波导的波导基底的正面,相邻的两个所述子光栅中的另一个位于所述波导基底的反面,位于所述波导基底的正面的所述子光栅的中心为中心一,位于所述波导基底的反面的所述子光栅的中心在所述波导基底的正面的垂直投影为中心二,所述相邻的两个所述子光栅的间距为所述中心一和所述中心二之间的距离。本方案提供了分布在波导基底的正反两面的耦出光栅的分布架构。
一种可能的实现方式中,光波导包括波导基底、耦入光栅、中继光栅和所述的耦出光栅,所述中继光栅位于所述耦入光栅和所述耦出光栅之间,所述耦出光栅包括第一子光栅区域和第二子光栅区域,所述第一子光栅区域距离所述中继光栅的距离小于所述第二子光栅区域距离所述中继光栅的距离,所述第一子光栅区域中的所述子光栅的高度小于所述第二子光栅区域中的所述子光栅的高度。本方案通过对耦出光栅的分区设置,并通过不同区域中的子光栅高度不同的设计,可以实现调节耦出光栅的衍射效率,有利于提升光均匀性。
一种可能的实现方式中,所述耦出光栅包括第一边缘和第二边缘,所述第一边缘为所述耦出光栅邻近所述中继光栅的边缘,所述第二边缘为所述耦出光栅远离所述中继光栅的边缘,从所述第一边缘向所述第二边缘的方向,所述子光栅的高度呈渐变增长趋势。本方案通过对耦出光栅中子光栅高度渐变的设计,可以实现调节耦出光栅的衍射效率,有利于提升光均匀性。
第九方面,本申请提供一种近眼显示设备,包括光机和第八方面任意一种可能的实现方式提供的光波导,所述光波导用于接收所述光机投射的光线。本方案提供的近眼显示设备因采用第八方面所述的光波导,能够解决VAC问题,提升近眼显示设备的图像显示效果。
第十方面,本申请提供一种近眼显示设备,包括光波导、控制单元、瞳孔检测件和光栅调节件,所述光波导包括耦出光栅,所述耦出光栅包括多个子光栅,多个所述子光栅阵列排布,各所述子光栅的最大径向尺寸为D,D≦1.5mm,相邻的两个所述子光栅的间距为L’,D≦L’≦4mm,L’指的是相邻的两个所述子光栅的中心之间的距离;所述瞳孔检测件用于检测瞳孔的尺寸,所述控制单元用于接收所述瞳孔检测件的信号,并驱动所述光栅调节件,所述光栅调节件用于控制所述耦出光栅的部分所述子光栅开启或关闭,以使部分所述子光栅处于工作状态,在工作状态下的相邻的两个所述子光栅之间的间距为L,3mm≦L≦5mm,L指的是工作状态下的相邻的两个所述子光栅的中心之间的距离。本方案设置的子光栅的阵列排列为较密集的方式,相邻的子光栅之间的距离可以为零,也就是说,子光栅可以一个挨着一个地相互接触的方式排列,相邻的子光栅之间也可以设置间隙。本方案通过相邻的两个所述子光栅的间距为L’的排列方案,结合光栅调节件实现开启部分子光栅,以使工作状态下的子光栅阵列中,相邻的工作状态的子光栅的中心之间的距离L的范围为:3mm≦L≦5mm。本方案采用可切换光学元件,通过控制子光栅的开关,使得工作状态的子光栅可以响应不同尺寸的瞳孔,例如,瞳孔尺寸变化的情况下,能够通过光栅调节件去调节工作状态的子光栅的间距,提高图像显示效率。本方案无需根据现实内容进行虚像距的切换,可以降低系统功耗。
本申请第九方面和第十方面提供的近眼显示设备可以包括如下任意一种方案或方案的组合:本申请第一方面任意一种可能的实现方式提供的合光单元、本申请第二方面任意一种可能的实现方式提供的光机、本申请第四方面提供的光学组件、第六方面任意一种可能的实现方式提供的光波导。
本申请第三方面、第五方面、第七方面提供的近眼显示设备,均可以包括第八方面任意一种可能的实现方式提供的光波导。
第十一方面,本申请提供一种光波导,包括波导基底和形成在所述波导基底上的光栅结构,所述光栅结构包括多个芯结构和膜结构,所述膜结构的折射率和所述芯结构的折射率不同,多个所述芯结构沿所述光栅结构的矢量方向依次间隔排列,各所述芯结构包括连接端、自由端和侧面,所述连接端连接至所述波导基底,所述自由端和所述连接端在所述芯结构的高度方向上相对设置,所述侧面连接在所述连接端和所述自由端之间,所述膜结构包括膜主体,第一端部和第二端部,所述膜主体包覆所述芯结构的所述侧面,所述第一端部和所述第二端部分别位于所述膜主体的两端,所述第一端部连接所述波导基底,所述第二端部和所述芯结构的所述自由端共面,所有所述芯结构的所述自由端和所述膜结构的所述第二端部共同构成所述光栅结构的端面。
本方案通过光栅的折射率的变化实现提升衍射效率及光学利用率,具体而言,通过光栅结构的芯结构和膜结构的折射率不同来提升衍射效率和光学利用率。通过芯结构的自由端和膜结构的第二端部共同构成光栅结构的端面,使得光栅结构的衍射效率更好,光栅结构只有在其矢量方向上具有折射率不同的芯结构和膜结构,在光栅结构的高度方向上,由于在光栅结构的端面位置,芯结构的自由端和膜结构的第二端部均外露状态,即光栅高度方向上芯结构的外部未被膜结构包覆,光栅结构的衍射效率可以得到保证。假若芯结构的自由端被膜结构包覆,包覆在芯结构自由端的部分膜结构会产生光栅结构高度方向上的衍射效果,但是,光栅结构高度方向上的衍射由于与光栅结构的矢量方向不同,会对光栅结构矢量方向上的衍射形成负面影响,即会降低光栅结构的衍射效率。
一种可能的实现方式中,所述芯结构的所述自由端的端面和所述膜结构的所述第二端部的端面共面。本方案提供的光栅结构中,自由端的端面和第二端部的端面共面,可以通过在芯结构上镀膜制作膜结构,通过化学机械抛光(CMP)等工艺将光栅结构的表面的膜结构打磨平整,实现共面的结构,本方案提供的共面结构易于实现,制作成本低。
一种可能的实现方式中,在相邻的所述芯结构之间,所述膜结构包括至少三层膜层,至少三层所述膜层层叠设置在相邻的所述芯结构的所述侧面之间,至少三层所述膜层具有不同的折射率,沿所述光栅结构的矢量方向,至少三层所述膜层的折射率呈正弦分布的渐变趋势。本方案提供的正弦渐变折射率光栅可以具有更高的衍射效率及更窄的半高全宽,可以满足特定角度入射效率的调制需求,从而提高整个系统的光效。
一种可能的实现方式中,在相邻的所述芯结构之间,所述至少三层膜层具有不同的厚度,厚度最大的所述膜层邻接所述芯结构,且所述芯结构的厚度大于厚度最大的所述膜层的厚度;或者,厚度最小的所述膜层邻接所述芯结构,且所述芯结构的厚度小于厚度最小的所述膜层的厚度。本方案通过厚度的差异化设计,实现折射率的不同。
一种可能的实现方式中,其中一层所述膜层包括一一对应交替间隔排布的多层第一子膜和多层第二子膜,所述第一子膜的折射率为N1,所述第二子膜的折射率为N2,所述多层第一子膜和所述多层第二子膜构成的所述膜层的折射率为N,N1<N<N2。本方案提供一种膜层折射率的调制方案,通过交替间隔排布的多层第一子膜和多层第二子膜的设置,得到满足条件的膜层,多制作工艺层面,具有易于实现的优势。
一种可能的实现方式中,相邻的所述芯结构之间的部分所述膜结构呈无缝隙结构。可以理解为,相邻的芯结构之间的空间被膜结构填满,没有留下任何空隙。本方案提供的光栅结构内部无空隙,使得光栅结构不易受环境因素影响其衍射效率。
一种可能的实现方式中,相邻的所述芯结构之间的所述膜结构的中间位置具有间隙。本方案提供一种芯结构之间具有间隙的方案,可以借助空气调制折射率,简化制作工艺,节约成本。
一种可能的实现方式中,所述芯结构内任意位置的折射率均相同。本方案有利于保证光栅结构的衍射效率稳定性。
一种可能的实现方式中,通过纳米压印工艺或刻蚀工艺在所述波导基底上形成所述芯结构,通过镀膜工艺制作所述膜结构。镀膜的制作工艺,易于批量处理,可以提升光栅结构的制作效率。
一种可能的实现方式中,所述芯结构的材料包括金属氧化物。
一种可能的实现方式中,光波导包括耦入光栅,所述耦入光栅包括第一耦入结构和第二耦入结构,所述第一耦入结构和所述第二耦入结构相对设置且分别位于所述波导基底的顶面和底面,所述第一耦入结构和所述第二耦入结构具有不同的光栅倾角;所述光栅结构为至少部分所述耦入光栅。第一耦入结构和第二耦入结构可以对不同方向的光线发生衍射,以使更多的光线被耦入波导基底,即,第一耦入结构和第二耦入结构结合以实现大角度范围内的高衍射效率。
一种可能的实现方式中,所述第一耦入结构和所述第二耦入结构均为所述光栅结构,所述第一耦入结构的芯结构的折射率高于所述第二耦入结构的芯结构的折射率,所述第一耦入结构的膜结构的折射率高于所述第二耦入结构的膜结构的折射率。本方案通过约束第一耦入结构与第二耦入结构之间的折射率不同,使得耦入光栅可以针对不同的角度或波长的光进行衍射。
一种可能的实现方式中,包括形成在所述波导基底上的耦入光栅和耦出光栅,所述耦出光栅为所述光栅结构,所述耦出光栅包括第一区和第二区,所述第一区相较所述第二区距离所述耦入光栅更近,所述第一区中的所述耦出光栅的芯结构和膜结构之间的折射率差为第一值,所述第二区中的所述耦出光栅的芯结构和膜结构之间的折射率差为第二值,所述第一值小于所述第二值。本方案用于调制衍射效率。
一种可能的实现方式中,包括中继光栅,所述中继光栅位于所述耦入光栅和所述耦出光栅之间,所述中继光栅为所述光栅结构,所述中继光栅包括第三区和第四区,所述第三区相较所述第四区距离所述耦入光栅更近,所述第三区中的所述中继光栅的所述芯结构和所述膜结构之间的折射率差为第三值,所述第四区中的所述中继光栅的所述芯结构和所述膜结构之间的折射率差为第四值,所述第三值小于所述第四值,所述第四值小于所述第一值。本方案用于调制衍射效率。
一种可能的实现方式中,所述中继光栅包括第一中继结构和第二中继结构,所述第一中继结构和所述第二中继结构分别设置在所述波导基底的顶面和底面,所述第一中继结构和所述第二中继结构具有不同的矢量方向。本方案用于调制衍射效率。
一种可能的实现方式中,所述第一中继结构和所述第二中继结构均为所述光栅结构,沿着所述第一中 继结构的矢量方向,所述第一中继结构的芯结构和所述第一中继结构的膜结构之间的折射率差逐渐增大。本方案用于调制衍射效率。
第十二方面,本申请提供一种近眼显示设备,包括光机和第十一方面任意一种可能的实现方式提供的光波导,所述光波导用于接收所述光机投射的光线。本方案提供的近眼显示设备由于采用了第十一方面任意一种可能的实现方式提供的光波导,使得近眼显示设备可以具有较好的图像显示效果。
本申请第十二方面提供的近眼显示设备可以包括如下任意一种方案或方案的组合:本申请第一方面任意一种可能的实现方式提供的合光单元、本申请第二方面任意一种可能的实现方式提供的光机、本申请第四方面提供的光学组件、第六方面任意一种可能的实现方式提供的光波导、第八方面任意一种可能的实现方式提供的光波导。
本申请第三方面、第五方面、第七方面、第九方面、第十方面提供的近眼显示设备,均可以包括第十一方面任意一种可能的实现方式提供的光波导。
第十三方面,本申请提供一种光波导,包括耦入区、耦出区和光线传播区,所述耦入区设有耦入光栅,所述耦入光栅用于接收入射光线,所述入射光线进入所述光波导后在所述光线传播区中全反射,所述耦出区设有耦出光栅,所述耦出光栅用于耦出光线,在所述光线传播区,所述光波导包括介质层和位于介质层两侧的第一光栅层和第二光栅层,所述第一光栅层和所述第二光栅层中的至少一个具有不同周期,所述介质层的折射率小于等于1.5。
本申请具体实施方式通过位于介质层两侧的第一光栅层和第二光栅层实现光线在光线传播区的全反射传播,通过限定介质层的折射率小于等于1.5,使得单独的介质层是无法实现光线的全反射传播的。本方案通过对介质层的折射率的范围的约束,能够保证介质层具有密度低重量轻的优势,有利于实现光波导的轻量化设计。本方案通过限定所述第一光栅层和所述第二光栅层中的至少一个具有不同周期,使得所述第一光栅层和所述第二光栅层中的至少一个即可以透射环境光,又可以全反射光波导内部传输的光线。
一种可能的实现方式中,所述第一光栅层和所述第二光栅层均具有不同周期。本方案通过限定第一光栅层和第二光栅层均具有不同的周期,能够提升光波导的透光性。
一种可能的实现方式中,所述第一光栅层和所述第二光栅层均为体全息光栅。本方案通过复用不同周期的体全息光栅,使得光线传播区即能够对进入光波导的入射光线进行全反射,还能对环境光具有较好的透过率。而且相对其它光栅类型(例如闪耀光栅、倾斜光栅),休全息光栅具有轻薄的优势。因此本方案有利于光波导的轻量化的设计。
一种可能的实现方式中,所述光波导还包括中继光栅,在光路传输的方向上,所述中继光栅位于所述耦入区和所述耦出区之间,所述光线传播区中的所述第一光栅层和所述第二光栅层位于所述耦入光栅和所述耦出光栅之间,且包围所述中继光栅。本方案提供了一种具有中继光栅的光波导架构,中继光栅的位置不在光线传播区内,第一光栅层和第二光栅层环绕中继光栅分布。一种具体的实施方式中,耦入光栅、耦出光栅、中继光栅、第一光栅层和第二光栅层均可以为体全息光栅。
一种可能的实现方式中,所述耦出光栅为二维光栅,所述光线传输区位于所述耦入光栅和所述耦出光栅之间,所述第一光栅层和所述第二光栅层填充所述耦入光栅和所述耦出光栅之间的所有区域。本方案提供了一种不具有中继光栅的具体的光波导架构,耦出光栅为二维光栅,这样,光线传播区就形成在耦入光栅和耦出光栅之间的区域。
一种可能的实现方式中,所述耦出光栅的周期和所述中继光栅的周期均需要满足的条件与所述耦入光栅的周期满足条件相同,所述耦入光栅、所述中继光栅和所述耦出光栅的周期方向和大小需要形成闭合的k空间。满足此条件,可以保证光波导投射的虚拟图像不会产生畸变,即能够保证图像的真实性,提升光波导的图像显示效果。
一种可能的实现方式中,光波导还包括第一保护层和第二保护层,第一保护层位于第一光栅层背离介质层的一侧,第一保护层覆盖在第一光栅层、耦入光栅和耦出光栅的表面,第一保护层用于保护第一光栅层、耦入光栅和耦出光栅,使得第一光栅层、耦入光栅和耦出光栅免受外界粉尘、空气或水气的侵蚀。第二保护层覆盖在第二光栅层的表面,用于保护第二光栅层,使得第二光栅层免受外界粉尘、空气或水气的侵蚀,从而有利于保证光波导的衍射效率及光学性能。
一种可能的实现方式中,所述光波导包括功能区和边缘区,所述功能区内设所述耦入光栅、所述耦出光栅和所述光线传播区中的所述第一光栅层和所述第二光栅层,所述边缘区的折射率小于所述功能区的折 射率,或者,所述边缘区的材料和所述功能区的材料不同。本方案提供的光波导通过功能区和边缘区的结合,边缘区可以为较轻的材质,有利于实现光波导的轻量化。
一种可能的实现方式中,所述第一光栅层和所述第二光栅层的周期范围为:大于等于100nm且小于等于700nm。对于复用体全息光栅的方案形成的第一光栅层和第二光栅层而言,其周期是和入射角度相对应的,通过限定大于等于100nm且小于等于700nm的光栅周期范围可以在保证入射角度的前提下,获得较高的衍射效率。
一种可能的实现方式中,所述第一光栅层的材料的体积收缩率范围和所述第二光栅层的材料的体积收缩率范围为:小于等于0.1%。本方案通过较小的体积收缩率的光栅结构,可以减小第一光栅层和第二光栅层的横向和纵向的变化率,从而减小周期、厚度和倾角的变化,保证第一光栅层和第二光栅层的设计和实际作用的角度和效率没有较大偏差。
一种具体的方案中,第一光栅层和第二光栅层膜厚可以为:>20um。第一光栅层和第二光栅层配合的入射光线的带宽<5nm(即窄带宽的入射光线),实现对耦入的光线的全反射传播。第一光栅层和第二光栅层的制作过程可以通过多次曝光获得,以使第一光栅层和第二光栅层具有多个周期,以实现即能全反射传播入射光线,又能提升环境光的透过率。
一种可能的实现方式中,所述光波导为单层架构;或所述光波导为双层架构;或所述光波导为三层架构,所述光波导为三层架构时,每层所述光波导均包括所述耦入光栅、所述耦出光栅和所述第一光栅层和所述第二光栅层。本方案限定了光波导的单层架构或三层架构,在任意一种架构下,均可以使用第一光栅层和第二光栅层作为光线传播区的全反射传播的媒介,本方案具有灵活性好的优势。
第十四方面,本申请提供一种近眼显示设备,包括光机和第十三方面任意一种可能的实现方式提供的光波导,所述光机发射的光线入射至所述耦入光栅上形成入射光线。一种可能的实现方式中,所述入射光线的带宽小于等于5nm。本申请提供的近眼显示设备,由于采用了第十三方面任意一种可能的实现方式提供的光波导,使得近眼显示设备可以具有重量轻,尺寸小的优势,能够提升使用者佩戴的体验感。
本申请第十四方面提供的近眼显示设备可以包括如下任意一种方案或方案的组合:本申请第一方面任意一种可能的实现方式提供的合光单元、本申请第二方面任意一种可能的实现方式提供的光机、本申请第四方面提供的光学组件、第六方面任意一种可能的实现方式提供的光波导、第八方面任意一种可能的实现方式提供的光波导、第十一方面任意一种可能的实现方式提供的光波导。
本申请第三方面、第五方面、第七方面、第九方面、第十方面、第十二方面提供的近眼显示设备,均可以包括第十三方面任意一种可能的实现方式提供的光波导。
第十五方面,本申请提供一种光波导,包括波导基底和增透层,所述增透层形成在所述波导基底的表面,所述增透层包括体全息材料,所述增透层包括折射率不同的高折射率相区和低折射率相区,所述高折射率相区和所述低折射率相区层叠设置在所述波导基底的表面,所述高折射率相区和所述低折射率相区为互相分离的不同区域,所述高折射率相区的折射率范围为:1.5-2.0,所述低折射率相区的折射率范围为1.1-1.5,所述高折射率相区中的组分和所述低折射率相区组分不同。
本方案通过改变体全息材料的内部结构或内部组分的排列方式,能够降低体全息材料的雾度。具体而言,本方案通过将增透层内部结构形成相间分布的高折射率相区和低折射率相区,而且高折射率相区和低折射率相区的组分不同。可以理解为,在增透层内相同组分的材料聚集在一个相区内,例如,高折射率相区中的组分为高分子聚合物和纳米粒子,而低折射率相区中的组分为单体所形成的高分子聚合物,即次高分子聚合物。这样高分子化合物和次高分子化合物分开,而不是混杂在一起,不容易形成微区团聚现象。因此,在增透层中无法形成大的聚合物颗粒,从而可以使得光波导具有低的雾度,提高光波导的透光性。
一种可能的实现方式中,所述高折射率相区的数量为多个,所述低折射率相区的数量为多个,多个所述高折射率相区和多个所述低折射率相区沿垂直于所述波导基底的表面的方向上相间分布。相间分布可以理解为ABABAB的排列方式。低折射率相区层叠设置在相邻的高折射率相区之间,或高折射率相区层叠设置在相邻的低折射率相区之间。本方案限定了一种增透层的具体的架构,通过高、低折射率相区的相间分布来解决增透层内的材料组分分区化管理,避免形成微区团聚现象,从而可以使得光波导具有低的雾度,提高光波导的透光性。
一种可能的实现方式中,所述体全息材料的主体为高分子聚合物材料,所述高分子聚合物材料的主要 元素组成包括:C、H、O、N、S、P中的一种或几种或全部。本方案限定了体全息材料的具体的成分,使得增透层的制作具有可实施性。
一种可能的实现方式中,所述体全息材料包括纳米粒子。本方案通过限定体全息材料中具有纳米粒子,通过纳米粒子实现不同组分的分区。
一种可能的实现方式中,所述纳米粒子的直径为:1nm~50nm。
一种可能的实现方式中,至少部分所述纳米粒子分布在所述高折射率相区,分布在所述高折射率相区的所述纳米粒子为二氧化钛、二氧化锆、硫化锌、碳量子点中的一种或几种或全部;和/或
至少部分所述纳米粒子分布在所述低折射率相区,分布在所述低折射率相区的所述纳米粒子为二氧化硅、氟化镁中的一种或全部。本方案限定了纳米粒子的具体分布方案,不同材质的纳米粒子可以选择性地分布在高折射率相区或低折射率相区。
一种可能的实现方式中,所述纳米粒子的体积分数含量为0~60%。本方案通过限制纳米粒子的体积分数来控制高折射率区和低折射率相区的形成以及二者的折射率,且解决光波导雾度的问题。具体而言,纳米粒子不能太多,太多会造成纳米粒子自身团聚,雾度增加;纳米粒子也不能太少,太少会减少不同相区之间的折射率差异。
一种可能的实现方式中,所述高折射率相区和所述低折射率相区为依次间隔层叠设置在所述波导基底表面的层结构,所述高折射率相区所形成的层结构的厚度和所述低折射率相区所形成的层结构的厚度相同或不同。
一种可能的实现方式中,各所述高折射率相区的厚度或各所述低折射率相区的厚度范围为:100nm~1000nm。例如,各所述高折射率相区的厚度或各所述低折射率相区的厚度为:200nm。本方案通过厚度范围的限制来控制增透层能够透过光的波长范围,不同厚度的增透膜对应不同的波长范围。
一种可能的实现方式中,所述光波导还包括耦入光栅和耦出光栅,所述耦入光栅和所述耦出光栅均形成在所述波导基底的表面,所述波导基底的表面设有非光栅区,所述非光栅区为所述耦入光栅和所述耦入光栅之外的区域,至少部分所述增透层位于所述非光栅区。本方案提供一种具体的光波导架构,光波导包括耦入光栅和耦出光栅,不具有中继光栅。本方案限定增透层位于光波导上非光栅区,用于提升非光栅区的环境光的透过性及光均匀性,能解决非光栅区的雾度问题。
一种可能的实现方式中,所述光波导还包括耦入光栅、中继光栅和耦出光栅,所述耦入光栅、所述中继光栅和所述耦出光栅形成在所述波导基底的表面,所述波导基底的表面设有非光栅区,所述非光栅区为所述耦入光栅、所述中继光栅和所述耦出光栅之外的区域,至少部分所述增透层位于所述非光栅区。本方案提供一种具体的光波导架构,光波导包括耦入光栅、中继光栅和耦出光栅。本方案限定增透层位于光波导上非光栅区,用于提升非光栅区的环境光的透过性及光均匀性,能解决非光栅区的雾度问题。
一种可能的实现方式中,部分所述增透层位于所述耦出光栅所在的位置且和所述耦出光栅形成共体结构,所述共体结构包括沿所述耦出光栅的矢量方向排列的光栅微结构,所述共体结构还包括沿所述光波导的法线方向相间分布的所述高折射率相区和所述低折射率相区。本方案通过在耦出光栅的位置处设置增透层,能够提升耦出光栅的透光率,耦出光栅不仅能将光波导中的光线耦出至人眼,还能透过环境光,本方案提供的光波导的耦出光栅的位置具有较好的透光性。
一种可能的实现方式中,所述耦出光栅与所述波导基底的连接的面为所述耦出光栅的耦出底面,所述耦出光栅背离所述波导基底的面为所述耦出光栅的耦出顶面,和所述耦出光栅形成所述共体结构的部分所述增透层形成在所述耦出底面和所述耦出顶面之间。本方案限定了耦出光栅和增透层形成共体结构的具体的架构,本方案不需要在耦出光栅之外的区域增加体全息材料,而是基于耦出光栅本身进行双光束曝光得到增透层结构,能够保证或尽量不影响耦出光栅的衍射效率。若在耦出顶面之外增加材料制作增透层,增加的材料部分会影响耦出光栅的衍射效率。
一种可能的实现方式中,所述耦出光栅的材料为体全息材料,通过全息复用技术制作所述共体结构。本方案提供的光波导具有制作工艺简单,易于实现的优势。
一种可能的实现方式中,所述光波导包括光栅结构,所述光栅结构为体全息材料,所述光栅结构形成在所述波导基底的表面,通过双光束曝光的工艺形成所述增透层和所述光栅结构,形成所述增透层的所述双光束曝光的工艺中的双光束之间的夹角的角平分线与所述波导基底的表面平行。本方案限定了使用双光束曝光的工艺制作增透层和光栅结构的过程中,双光束曝光的工艺中的双光束之间的夹角的角平分线与所述波导基底的表面平行,此种方式得到的增透层的矢量方向为垂直于波导基底的表面的方向,即增透层为层叠在波导基底表面的层叠分布的架构,由于增透层的矢量方向和光栅结构的矢量方向不同,本方案提供 的光波导中,增透层的引入不会影响光栅结构的衍射性。
第十六方面,本申请提供一种近眼显示设备,包括光机和第十五方面任一种可能的实现方式提供的光波导,所述光机位于所述光波导的入光侧。
本申请第十六方面提供的近眼显示设备可以包括如下任意一种方案或方案的组合:本申请第一方面任意一种可能的实现方式提供的合光单元、本申请第二方面任意一种可能的实现方式提供的光机、本申请第四方面提供的光学组件、第六方面任意一种可能的实现方式提供的光波导、第八方面任意一种可能的实现方式提供的光波导、第十一方面任意一种可能的实现方式提供的光波导、第十三方面任意一种可能的实现方式提供的光波导。
本申请第三方面、第五方面、第七方面、第九方面、第十方面、第十二方面、第十四方面提供的近眼显示设备,均可以包括第十五方面任意一种可能的实现方式提供的光波导。
第十七方面,本申请提供一种光波导的制作方法,用于制作第十五方面任意一种可能的实现方式提供的光波导,所述光波导的制作方法包括:
提供基板,所述基板为所述光波导的波导基底;
在所述基板的表面设置材料层,所述材料层包括体全息材料;
对具有所述材料层的所述基板进行前处理;
执行双光束曝光工艺,使得所述材料层形成具有高折射率相区和低折射率相区相间分布的结构;
固化成型,以使所述材料层被调制为所述波导基底上的增透层。
一种可能的实现方式中,所述材料层包括高分子聚合物、单体、光引发体系、溶剂,所述高分子聚合物为含有C、H、O、N的分子量大于1000的聚合物,所述单体包括丙烯酸酯类、丙烯酰胺类、含巯基化合物、烯丙基类、乙烯基类化合物中的至少一种,所述光引发体系用于吸收激光能量,且形成活性物质,以使所述活性物质与所述单体反应,将所述单体转化为次高分子聚合物。
一种可能的实现方式中,所述双光束曝光工艺的光源包括两束扩束的相干激光,所述两束扩束的相干激光相互干涉形成光强呈正弦波分布,以在所述材料层上形成高光强区和低光强区,所述高光强区所述光引发体系吸收的能量多于所述低光强区所述光引发体系吸收的能量,以使得所述高光强区的所述活性物质多于所述低光强区的所述活性物质,以使所述高分子聚合物和所述次高分子聚合物分离,形成所述高折射率相区与所述低折射率相区相间分布架构。
一种可能的实现方式中,所述高分子聚合物包括聚醚、聚醋酸乙烯酯、聚醋酸乙烯-丙烯共聚物、聚乙烯、聚丙烯、聚氯乙烯、聚对苯二甲酸乙二酯、聚苯乙烯、聚碳酸酯、聚氨酯、聚酯多元醇、醋酸纤维素、聚乙烯醇中的至少一种。
一种可能的实现方式中,通过涂布的工艺在所述基板的表面设置所述材料层。
一种可能的实现方式中,对具有所述材料层的所述基板进行前处理的步骤包括:25~100℃高温处理,或低压处理,或避光处理,或室温放置处理。
一种可能的实现方式中,所述固化成型的步骤包括高温固化成型和光照固化成型,所述高温固化成型的温度为40~150℃,所述光照固化成型的光强为0.1~5000mWcm-2,所述光照固化成型的波长范围为254nm~1000nm,用于所述光照固化成型的光的类型包括UVA、UVB、UVC、可见光、红外光波段中的任一种。
一种可能的实现方式中,所述执行双光束曝光工艺的步骤中,双光束之间的夹角为第一角度。
一种可能的实现方式中,光波导的制作方法还包括通过双光束曝光工艺制作光栅结构,通过夹角为第二角度的双光束进行曝光,形成所述光栅结构,所述光栅结构和至少部分所述增透层可以位于所述基底上的同一位置,所述第一角度和所述第二角度不同。
第十八方面,本申请提供一种光波导,应用于近眼显示设备,所述光波导包括第一波导基底、第一光栅结构和第一填充层,所述第一光栅结构形成于所述光第一波导基底的表面,所述第一填充层和所述第一波导基底层叠设置,且所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2。本申请一种实施方式通过在波导基底上的光栅结构的外围设置填充层,利用填充层保护光栅结构和波导基底,实现对光波导的保护及提升光波导的寿命和光学性能。具体而言,本方案 通过设置第一填充层,实现对第一波导基底和第一光栅结构的保护,使得第一波导基底和第一光栅结构与外界空气隔离,能够保证第一波导基底和第一光栅结构避免长期接触水氧环境,解决了光波导易老化、被腐蚀及雾化等问题,还能够抵御外界冲击力避免光波导损坏,本申请提供的实施方式能够保证光波导的使用寿命和光学性能。
一种可能的实现方式中,所述第一填充层包括光栅接触面,所述光栅接触面具有与所述第一光栅结构相同的周期性排列的微结构,以使得所述第一填充层的所述光栅接触面和所述第一光栅结构的微结构的表面贴合。本方案实现了第一填充层和第一光栅结构之间无气隙式地接触。第一填充层的光栅接触面和第一光栅结构的微结构的表面贴合,即部分第一填充层填充在第一光栅结构和周期性排列的微结构所构成的狭缝中。本实施方式提供的光波导中,第一光栅结构的外围没有任何气隙,第一光栅结构通过与第一填充层完全接触,实现与空气的完全隔离,这样可以提升第一光栅结构的寿命。
一种可能的实现方式中,所述第一填充层包括光栅接触面,所述光栅接触面为平面状,所述第一填充层和所述第一光栅结构之间具有周期性排列的狭缝。本方案允许光栅接触面和第一光栅结构的表面之间存在狭缝,本方案提供的第一填充层的制作工艺的精度要求较低,易于制作。
一种可能的实现方式中,所述第一填充层的透光性大于等于80%。本方案限定第一填充层的透光性,可以保证光波导的透光性。
一种可能的实现方式中,所述第一填充层的厚度小于等于1000um。本方案通过限定第一填充层的厚度保证光波导的折射率、透光性,以及使得光波导具有轻量化优势。
一种可能的实现方式中,所述第一填充层的材料包括气凝胶材料、树脂材料、无机材料、有机材料中的任意一种或多种的组合。
一种可能的实现方式中,所述第一填充层的材料为二氧化硅气凝胶。具体而言,在二氧化硅材料中引入孔隙构成二氧化硅气凝胶。让空气分担一部分折射率,例如二氧化硅50%的孔隙率,那么复合折射率就是1.5*50%+1*50%=1.25。二氧化硅气凝胶可以作为第一填充层的材料。二氧化硅气凝胶是由纳米二氧化硅粒子相互连接构成的一种具有纳米级孔径的三维多孔网络结构的固态材料,这些孔洞中充满了空气,通过调节二氧化硅气凝胶的孔隙来调节折射率,目前可以做到气凝胶90%以上的体积都是空气,纯净的二氧化硅气凝胶透明无色,折射率最低可达到1.007,接近空气折射率。且由于大部分体积都是空气,因此密度也非常低,同时还具有良好的透光性和硬度,目前可达到95%的光透过性,亦可承受自身重量几千倍的压力。
一种可能的实现方式中,所述光波导还包括第一盖板,所述第一盖板和所述第一波导基底固定连接,所述第一填充层层叠设置在所述第一盖板和所述第一波导基底之间,所述第一填充层和所述第一盖板贴合。本方案提供了一种具有第一盖板的光波导架构,通过第一填充层填充在第一盖板和第一波导基底之间,使得第一盖板和第一波导基底之间无气隙,第一填充层对第一盖板提供支撑力,能够防止第一盖板受外部应用破损。
一种可能的实现方式中,所述第一盖板和所述第一波导基底之间通过点胶结构固定连接,所述点胶结构分布在所述第一填充层的周围。本方案提供了第一盖板和第一波导基底之间的固定方案,点胶固定的结构易于操作,而且,由于第一填充层已经覆盖了第一波导基底的大部分面积,胶水不会对第一波导基底的光学性能带来破坏性的影响。
一种可能的实现方式中,所述光波导还包括第二光栅结构、第二填充层和第二盖板,所述第二光栅结构和所述第一光栅结构分布在所述第一波导基底相对的两侧,所述第二填充层和所述第一波导基底层叠设置,且所述第二填充层和所述第一光波基底共同封闭包围所述第二光栅结构,所述第二填充层的折射率和空气的折射率之间的差值小于等于0.2,所述第二盖板和所述第一波导基底固定连接,所述第二填充层层叠设置在所述第二盖板和所述第一波导基底之间,所述第二填充层和所述第二盖板贴合。本方案提供一种单层双面的光波导架构,通过第二填充层和第二盖板实现对第二光栅结构的保护。
一种可能的实现方式中,所述光波导还包括第二波导基底和第三光栅结构,所述第三光栅结构形成在所述第二波导基底上,所述第二波导基底和所述第一波导基底层叠设置,所述第二波导基底和所述第一光波导基底之间设有第三填充层,所述第三填充层的折射率和空气的折射率之间的差值小于等于0.2。本方案提供一种双层光波导架构,且通过在第一波导基底和第二波导基底之间设第三填充层来保护第三光栅结构。
一种可能的实现方式中,所述光波导还包括至少两个第二波导基底,各所述第二波导基底上均设有第 三光栅结构,至少两个所述第二波导基底层叠设置在所述第一波导基底背离所述第一填充层的一侧,所述第二波导基底和所述第一波导基底之间,以及相邻的所述第二波导基底之间均设有第三填充层,所述第三填充层和所述第二波导基底共同包围所述第三光栅结构,所述第三填充层的折射率和空气的折射率之间的差值小于等于0.2。本方案提供一种多层光波导架构,相邻层之间通过第三填充层填充,保护第三光栅结构,且提供多层波导基底之间的支撑和连接。
一种可能的实现方式中,所述光波导还包括第二波导基底,所述第二波导基底和所述第一波导基底层叠设置,所述第二波导基底的表面设有第三光栅结构,所述第三光栅结构和所述第一光栅结构相对设置,所述第一填充层填充在所述第一波导基底和所述第二波导基底之间,所述第一填充层覆盖第二波导基底和第三光栅结构。本实施方式提供的光波导中第一波导基底的顶面和第二波导基底的底面可以作为光波导的表层,不需要再设置其它的盖板结构,有利于光波导轻薄化的设计。本方案提供的光波导具有轻量化的优势。
第十九方面,本申请提供一种光波导,包括第一波导基底、第一光栅结构、波导填充结构、第三光栅结构和第一填充层,所述第一光栅结构形成在所述第一波导基底的表面,所述波导填充结构包裹所述第一光栅结构且覆盖所述第一波导基底,所述第三光栅结构形成在所述波导填充结构背离所述第一波导基底的表面,所述第一填充层覆盖所述波导填充结构,所述第一填充层和所述波导填充结构共同形成封闭的包围架构,所述第三光栅结构位于所述包围架构内,以使所述第三光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2。本方案借助波导填充结构构建了一层光栅结构。其它实施方式中,也可以借助波导填充结构构建多层(两层或两层以上)光栅结构。本方案提供一种单层波导基底的基础上,结合波导填充结构所构建的多层架构,利用波导填充结构和第一填充层实现对各层光栅结构的保护,最外层的第一填充层与盖板合,还具有支撑和保护盖板的作用。
一种可能的实现方式中,所述波导填充结构的折射率和所述第一波导基底的折射率之间的差值在0-0.5之间。本方案限制了波导填充结构和第一波导基底之间的折射率差的范围,通过此范围的约束,使得各层光栅结构均能够执行衍射效率,使得波导填充结构和第一波导基底均具有全反射传播光线的功能。
一种可能的实现方式中,所述光波导还包括第一盖板,所述第一盖板位于所述第一填充层背离所述波导填充结构的一侧。本方案通过设置第一盖板来做为光波导的保护层,通过第一填充层可以支撑和保护第一盖板,避免第一盖板在外部应力作用下破损。
一种可能的实现方式中,所述波导填充结构的边缘相较第一波导基底内缩,以在第一波导基底的边缘预留位置用于设置点胶结构,所述点胶结构固定连接所述第一盖板和所述第一波导基底。本方案限定了第一盖板和第一波导基底之间的固定连接方式,通过点胶连接,可以保证光波导的结构稳定性。
第二十方面,本申请提供一种近眼显示设备,包括光机和第十八方面任意一种可能的实现方式所述的光波导或第十九方面任意一种可能的实现方式所述的光波导,所述光波导位于所述光机的出光侧。
本申请第二十方面提供的近眼显示设备可以包括如下任意一种方案或方案的组合:本申请第一方面任意一种可能的实现方式提供的合光单元、本申请第二方面任意一种可能的实现方式提供的光机、本申请第四方面提供的光学组件、第六方面任意一种可能的实现方式提供的光波导、第八方面任意一种可能的实现方式提供的光波导、第十一方面任意一种可能的实现方式提供的光波导、第十三方面任意一种可能的实现方式提供的光波导、第十五方面任意一种可能的实现方式提供的光波导。
本申请第三方面、第五方面、第七方面、第九方面、第十方面、第十二方面、第十四方面、第十六方面提供的近眼显示设备,均可以包括第十八方面任意一种可能的实现方式所述的光波导或第十九方面任意一种可能的实现方式所述的光波导。
第二十一方面,本申请提供一种光波导的制作方法,包括:
提供第一盖板,在所述第一盖板上涂设第一填充材料,以在第一盖板上形成第一填充层;
提供第一波导基底,所述第一波导基底上设有第一光栅结构;
对位所述第一盖板和所述第一波导基底,使得所述第一填充层和所述第一波导基底结合且共同封闭包围所述第一光栅结构;
固定所述第一盖板和所述第一波导基底,以使所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2。
第二十二方面,本申请提供一种光波导的制作方法,包括:
提供第一波导基底,所述第一波导基底上设有第一光栅结构;
提供硬质母模,所述硬质母模上具有光栅模结构,所述光栅模结构与所述第一光栅结构形态相同;
对所述硬质母模承载所述光栅模结构的表面及所述光栅模结构的表面进行疏水处理;
在所述硬质母模上涂设第一填充材料,以形成第一填充层;
将第一盖板贴设在所述第一填充层上,使得所述第一盖板和所述第一填充层结合为一体;
脱模,使得所述第一盖板和所述第一填充层与所述硬质母模脱离;
对位所述第一盖板和所述第一波导基底,以使所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2;
固定所述第一盖板和所述第一波导基底。
第二十三方面,本申请提供一种光波导的制作方法,包括:
提供一种光波导中间结构,所述光波导中间结构包括第一波导基底、第一光栅结构和第一盖板,所述第一光栅结构形成在所述第一波导基底的表面,所述第一盖板和所述第一波导基底层叠设置且固定连接,所述第一盖板和所述第一波导基底之间及所述第一盖板和所述第一光栅结构之间形成间隙;
在所述第一盖板上设注入孔;
通过所述注入孔注入填充材料,以形成第一填充,所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2。
第二十四方面,本申请提供一种光波导的制作方法,包括:
提供第一波导基底,所述第一波导基底上设有第一光栅结构;
将填充材料涂覆至所述第一波导基底的表面和所述第一光栅结构的表面,形成第一填充层,所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2;
在所述第一填充层的边缘,且在所述第一波导基底的表面设置点胶结构;
将第一盖板固定至所述点胶结构,使得所述第一盖板和所述第一波导结构固定连接。
第二十五方面,本申请提供一种光波导,包括波导基底和光栅结构,所述光栅结构和所述波导基底结合,所述波导基底包括第一基材层和第二基材层,所述第一基材层的折射率低于所述第二基材层的折射率,所述第二基材层的折射率和所述第一基材层的折射率的差值大于等于0.1,所述第二基材层的厚度介于50微米至300微米之间;所述光栅结构位于所述第二基材层背离所述第一基材层的一侧,和/或,所述光栅结构位于所述第一基材层和所述第二基材层之间。本方案通过将波导基底设计为由第一基材层和第二基材层层叠构成的复合材料,通过对第二基材层的厚度的约束,以及对第一基材层和第二基材层的折射率差的约束,能够实现光波导的轻量化。
一种可能的实现方式中,所述第一基材层的材料为玻璃,且所述第一基材层的折射率小于等于1.55。本方案通过限制第一基材层的材料和折射率范围,实现第一基材层为低折射率的材料,具有密度小、重量轻和厚度小的特点。本申请提供的实施方式不仅能够降低波导基底的重量、减小波导基底的厚度,还能够降低光波导的重量、减小光波导的厚度。从而能够在满足光线能够在其中全反射传播(光学性能)的基础上,实现光波导的轻量化。
一种可能的实现方式中,所述第二基材层的折射率大于等于1.65。本方案约束第二基材层的折射率范围,使得第二基材层可以满足光的全反射传播的功能。
一种可能的实现方式中,所述第二基材层的材料为TiO2、氮化硅、氮化镓、高折树脂材料中的一种或至少两种的组合。
一种可能的实现方式中,所述第一基材层用于在制作所述第二基材层过程中承载形成所述第二基材层的材料,所述第二基材层通过制作工艺和所述第一基材层结合为一体成型的结构。本方案有利于光波导的轻量化的实现。
一种可能的实现方式中,所述第一基材层的表面通过刻蚀工艺形成沟槽状的微结构,所述第二基材层形成在所述第一基材层的表面且与所述沟槽状的微结构结合,以形成至少部分所述光栅结构。本方案限定了第一基材层和第二基材层之间可以形成光栅结构,刻蚀工艺形成沟槽状的微结构有利于实现光波导整体 的轻量化,在此位置设置光栅结构也能够提升光波导的衍射效率。
一种可能的实现方式中,所述第一基材层的表面设有至少部分光栅层,所述光栅结构的至少部分位于所述光栅层,所述第二基材层通过制作工艺直接形成在所述光栅层背离所述第一基材层的表面。本方案限定了在第一基材层和第二基材层之间通过光栅层来制作光栅结构的具体方式,有利于提升光波导的衍射效率。
一种可能的实现方式中,所述波导基底的厚度小于0.35mm。第一基材层不但用于在制作光波导的过程中承载第二基材层,第一基材层还用做保护第二基材层和光栅结构免受外界粉尘、空气或水气的侵蚀,保证光波导的衍射效率。
一种可能的实现方式中,至少部分所述光栅结构形成在所述第二基材层背离所述第一基材层的表面。本方案提供一种在第二基材层的背离第一基材层的表面具有光栅结构的方案,本方案的设计使得光波导的设计具有更多的灵活性。
一种可能的实现方式中,所述第二基材层背离所述第一基材层的一侧设有保护层。保护层用于保护第二基材层和光栅结构。
一种可能的实现方式中,所述光波导包括功能区和边缘区,所述边缘区包围所述功能区,所述波导基底和所述光栅结构位于所述功能区,所述边缘区设波导边缘主体,所述波导边缘主体和所述波导基底的边缘结合,所述波导边缘主体具透光性,且所述波导边缘主体的密度小于所述第一波导基底材料的密度。本实施例中,边缘区密度小于第一基材层的密度,所以位于波导基底外侧的边缘区有利于实现光波导的轻量化。
一种可能的实现方式中,所述波导边缘主体的材质为树脂材料。本方案通过限定波导边缘主体的材质实现光波导的轻量化。
一种可能的实现方式中,所述波导边缘主体的折射率为:1.55-1.75。本方案通过限定波导边缘主体的折射率范围实现光波导的轻量化。
一种可能的实现方式中,所述光波导还包括包裹层,所述包裹层全包裹或半包裹所述波导基底和所述光栅结构,所述包裹层的外表面包括第一表面,所述第一表面为曲面,以矫正不同的近视度数。本方案通过包裹层和波导基底及光栅结构的结构,使得光波导可以适用于正不同的近视度数。
一种可能的实现方式中,所述包裹层的至少一个表面具有不同的曲率。本方案通过限制包裹层具有不同曲率的表面,使得包裹层不仅可以补偿因波导基底与包裹层之间折射率差异导致的视角偏差,还可以用于矫正不同的近视度数。
第二十六方面,本申请提供一种近眼显示设备,包括光机和第二十五方面任意一种可能的实现方式提供的光波导,所述光波导位于所述光机的出光侧。
本申请第二十六方面提供的近眼显示设备可以包括如下任意一种方案或方案的组合:本申请第一方面任意一种可能的实现方式提供的合光单元、本申请第二方面任意一种可能的实现方式提供的光机、本申请第四方面提供的光学组件、第六方面任意一种可能的实现方式提供的光波导、第八方面任意一种可能的实现方式提供的光波导、第十一方面任意一种可能的实现方式提供的光波导、第十三方面任意一种可能的实现方式提供的光波导、第十五方面任意一种可能的实现方式提供的光波导、第十八方面任意一种可能的实现方式所述的光波导、第十九方面任意一种可能的实现方式所述的光波导。
本申请第三方面、第五方面、第七方面、第九方面、第十方面、第十二方面、第十四方面、第十六方面、第二十方面提供的近眼显示设备,均可以包括第二十五方面任意一种可能的实现方式所述的光波导。
第二十七方面,本申请实施例提供一种光波导的制作方法,包括:在基底层上制作第一光栅层,所述第一光栅层具有第一光栅结构,使得所述第一光栅层和所述基底层层叠设置;通过光栅结构模板制作第二光栅层,将所述第二光栅层制作在所述第一光栅层背离所述基底层的一侧,所述第二光栅层具有第二光栅结构,在所述第一光栅层和所述第二光栅层之间具有增粘层;脱模所述光栅结构模板,以使所述基底层、所述第一光栅层和所述第二光栅层结合为一体构成光波导。具体地,在基底层上旋涂第一压印材料层,提供第一光栅结构模板,通过纳米压印工艺把第一光栅结构模板压到第一压印材料层上,然后固化第一压印材料层,脱模后得到第一光栅层;再通过第二光栅结构模板制作第二光栅层,并利用增粘层将第一光栅层和第二光栅层粘接。
本申请通过在第一光栅层和第二光栅层之间设置增粘层,使得第一光栅层和第二光栅层分隔,所以在制作第二光栅层时不会由于压力或冲击力对第一光栅层造成影响,降低了第一光栅层变形损坏的概率。并 且,利用增粘层具有粘接性的特点,能够在第二光栅层与增粘层连接后保持二者之间的牢固性,从而提高脱模的可靠性。同时,第二光栅层可以通过增粘层粘接在第一光栅层上,从而提高了第一光栅层和第二光栅层连接强度,能够避免第一光栅层和第二光栅层之间松脱,有利于光波导的后续加工。
一种可能的实施方式中,通过所述光栅结构模板制作所述第二光栅层的步骤包括:在所述第一光栅层上制作介质层;在所述介质层上涂覆所述增粘层;在所述增粘层上涂覆第二压印材料层;通过所述光栅结构模板在所述第二压印材料层所述第二光栅结构,以形成所述第二光栅层。具体地,上述步骤中的光栅结构模板应该为第二光栅结构模板,用于制作第二光栅层。通过在涂覆增粘层前在制第一光栅层上作介质层,使得介质层可以对第一光栅层形成力学保护,确保在压印第二光栅层的过程中第一光栅层不易变形。同时通过在第一光栅层表面制作介质层还能够提高光线在第一光栅层的折射率,从而实现光波导的优异光学性能。
一种可能的实施方式中,通过所述光栅结构模板制作所述第二光栅层的步骤之前,所述制作方法包括:对所述光栅结构模板的工作表面做抗粘处理,通过所述光栅结构模板在所述第二压印材料层上制作所述第二光栅层的过程中,所述工作表面和所述第二压印材料层接触。通过对工作表面进行抗粘处理是为了能够在第二压印材料层固化为第二光栅层之后更为顺利的脱模,避免第二光栅层与第二光栅结构模板粘连,防止破坏第二光栅层的完整性。
一种可能的实施方式中,在所述第一光栅层上制作介质层的步骤包括:通过镀膜工艺将所述介质层形成在所述第一光栅层上。通过镀膜工艺制作介质层的优点在于该工艺技术简单,且易于实现量产。
一种可能的实施方式中,所述介质层的材料包括氧化物或氮化物;一种可能的实施方式中,所述介质层的折射率在1.8~2.3之间。介质层的折射率高,能有效提升光效率,提高具有该光波导结构的电子设备的视场角。在其他实施方式中,介质层的折射率还可以大于2.3。
一种可能的实施方式中,在所述第一光栅层上制作介质层的步骤还包括:通过化学机械研磨工艺对所述介质层进度表面处理。具体地,通过上述实施方式中的步骤所制作的介质层背向第一光栅层的一侧可以形成具有平行于(或近似平行于)基底层的表面,通过对该表面进行处理的目的在于提高该表面的粗糙度,从而提高介质层表面的吸附力,避免增粘层脱落。
一种可能的实施方式中,所述第二压印材料层的折射率在1.6~1.9之间,一种可能的实施方式中,所述第二压印材料层厚度在100~400nm之间。第二压印材料层的折射率高,能有效提升光效率,提高具有该光波导结构的电子设备的视场角。在其他实施方式中,第二压印材料层的折射率还可以大于1.9。同时,控制第二压印材料层厚度在100~400nm之间可以确保所得到的第二光栅层的厚度不超过该范围的最大值,从而能够有效控制光波导结构的整体厚度,实现具有该光波导结构的电子设备的轻薄化。
一种可能的实施方式中,所述增粘层的厚度在0~20nm之间。可以理解地,将增粘层的厚度控制在该范围内,可以在不影响光波导结构的整体厚度的情况下,确保第一光栅层和基底层之间的连接强度。当增粘层的厚度超过这个范围时,容易导致光波导结构的整体厚度过厚,且影响光线的折射。
一种可能的实施方式中,通过所述光栅结构模板制作所述第二光栅层的步骤包括:提供所述光栅结构模板;在所述光栅结构模板上制作第二光栅层;通过所述增粘层将连接所述光栅结构模板的所述第二光栅层粘接在所述第一光栅层上。具体地,上述步骤中的光栅结构模板应该为第二光栅结构模板,用于制作第二光栅层。通过将第二光栅层预先制作在光栅结构模板上,使得第一光栅层和第二光栅层的制作步骤可以同时进行,无需依顺序制作各层级结构;在分别制作第一光栅层和第二光栅层后再通过增粘层粘接,以此可以提高制造效率,有助于规模化生产。
一种可能的实施方式中,通过所述光栅结构模板制作所述第二光栅层的步骤包括:先在所述第二光栅层背离所述光栅结构模板的表面涂覆所述增粘层,再将所述第一光栅层粘贴在所述增粘层上。具体地,第二光栅层应该通过在第二光栅结构模板上涂覆第二压印材料层制作而成。而在第二压印材料层未固化前,可以在第二压印材料层背离第二光栅结构模板的一面设置增粘层,然后将第二压印材料层连同第二光栅结构模板一起设置在第一光栅层上,再固化第二压印材料层。通过该方式设置的增粘层可以通过第二压印材料层可形变的特点完全被覆盖在第一光栅层上,提高增粘层的均匀性。
一种可能的实施方式中,所述制作方法还包括,在所述第一光栅层上制作介质层,通过所述增粘层将连接所述光栅结构模板的所述第二光栅层粘接在所述介质层上。通过在涂覆增粘层前在制第一光栅层上作介质层,使得介质层可以对第一光栅层形成力学保护,进一步确保在压印第二光栅层的过程中第一光栅层不易变形。同时通过在第一光栅层表面制作介质层还能够提高光线在第一光栅层的折射率,从而实现光波导结构的优异光学性能。
一种可能的实施方式中,所述介质层的表面形态与所述第一光栅层的表面形态相同。介质层可以通过镀膜工艺制作在第一光栅层的表面,并且介质层相背的两面形态均与第一光栅层的表面形态相同。可以理解地,介质层可以在第一光栅层的表面形成较薄的膜层,用于确保第一光栅层上的反光效果,相比于上述实施方式中制作介质层且呈现平铺的表面,本实施方式中的介质层更薄,可以实现对光波导结构的减薄效果,从而制造更为轻薄的电子设备。
一种可能的实施方式中,所述介质层的折射率在1.8~2.3之间,所述介质层的厚度在0~50nm之间。介质层具体材质可以为氧化物,如二氧化钛等。通过设计介质层的折射率在1.8~2.3之间,使得介质层能够具有高折射率,从而光机发射的光线能够通过介质层在第一光栅层上形成更好的反射效果,从而实现光波导结构的优异光学性能。
一种可能的实施方式中,通过所述增粘层将连接所述光栅结构模板的所述第二光栅层粘接在所述第一光栅层上的过程中,所述增粘层和所述第一光栅层直接接触。通过设计增粘层和第一光栅层直接接触,即增粘层和第一光栅层之间不设置介质层,可以实现光波导结构的减薄效果,以此在各层级厚度不变的情况下降低光波导结构的厚度。
一种可能的实施方式中,在所述光栅结构模板上制作第二光栅层的步骤之前,对所述光栅结构模板的工作表面做抗粘处理,在所述光栅结构模板上制作第二光栅层的过程中,在所述工作表面上制作所述第二光栅层。通过对工作表面进行抗粘处理是为了能够在第二压印材料层固化为第二光栅层之后更为顺利的脱模,避免第二光栅层与第二光栅结构模板粘连,防止破坏第二光栅层的完整性。
一种可能的实施方式中,在所述基底层上制作所述第一光栅层的步骤包括:在所述基底层上涂覆第一压印材料层,通过纳米压印工艺在所述第一压印材料层上形成所述第一光栅层,形成所述第一光栅层的过程中所述第一压印材料承受的力为第一压力,通过所述增粘层将连接所述光栅结构模板的所述第二光栅层粘接在所述第一光栅层上的过程中,所述第一光栅层和所述第二光栅层承受的力为第二压力,所述第二压力小于等于所述第一压力。可以理解地,通过纳米压印工艺制作的第一光栅层和第二光栅层均可以具有微纳米结构,在制作第一光栅层时其下方为基底层且不具备微纳米结构,所以为了保证第一光栅层成型可以使用较大的第一压力。而在第一光栅层上制作第二光栅层时,第一光栅层上具备微纳米结构,为了防止压印力过大而破坏第一光栅层上的微纳米结构,所以第二压力应该小于第一压力,从而达到保护第一光栅层的目的。
一种可能的实施方式中,所述第一光栅层的材料和所述第二光栅层的材料不同。可以理解地,第一光栅层的材料和所述第二光栅层的材料可以相同或不同。而第一光栅层和第二光栅层制作时所接触的基底不同,所以可以根据材料特性选着不同的材料分别制作第一光栅层和第二光栅层。
一种可能的实施方式中,所述第一光栅层上的第一光栅结构和所述第二光栅层上的所述第二光栅结构具有不同的结构,一种可能的实施方式中,所述第一光栅结构和所述第二光栅结构具有不同尺寸或周期。具体地,第一光栅结构为耦入结构,第二光栅结构为耦出结构。第一光栅结构和第二光栅结构为光波导结构上的微纳米结构,用于反光或透光,所以第一光栅结构和所述第二光栅结构可以根据所需作用的光线从而设计不同的形状、尺寸或周期。
第二十八方面,本申请实施例还提供一种光波导,包括基底层、第一光栅层、第二光栅层和增粘层;第一光栅层与所述基底层层叠设置,所述第一光栅层具有第一光栅结构;第二光栅层层叠设置在所述第一光栅层背离所述基底层的一侧,所述第二光栅层具有第二光栅结构,增粘层在所述第一光栅层和所述第二光栅层之间。
本申请通过在第一光栅层和第二光栅层之间设置增粘层,使得第一光栅层和第二光栅层分隔,所以在制作第二光栅层时不会由于压力或冲击力对第一光栅层造成影响,降低了第一光栅层变形损坏的概率。并且,利用增粘层具有粘接性的特点,能够在第二光栅层与增粘层连接后保持二者之间的牢固性,从而提高脱模的可靠性。同时,第二光栅层可以通过增粘层粘接在第一光栅层上,从而提高了第一光栅层和第二光栅层连接强度,能够避免第一光栅层和第二光栅层之间松脱,有利于光波导结构的后续加工。
一种可能的实施方式中,所述第一光栅层和所述增粘层之间具有介质层。
一种可能的实施方式中,所述介质层的材料包括氧化物或氮化物;一种可能的实施方式中,所述介质层的折射率在1.8~2.3之间。
一种可能的实施方式中,所述介质层的表面形态与所述第一光栅层的表面形态相同。
一种可能的实施方式中,所述增粘层厚度在0~20nm之间。
一种可能的实施方式中,所述第一光栅层的折射率在1.6~1.9之间,一种可能的实施方式中,所述第 一光栅层厚度在100~400nm之间。
一种可能的实施方式中,所述第一光栅层包括第一光栅结构,所述第二光栅层包括第二光栅结构,所述第一光栅结构和所述第二光栅结构具有不同的结构,一种可能的实施方式中,所述第一光栅结构和所述第二光栅结构具有不同尺寸或周期。
第二十九方面,本申请提供一种近眼显示设备,包括光机和第二十八方面中任意一种可能的实现方式提供所述的光波导,所述光波导位于所述光机的出光侧。
本申请第二十九方面提供的近眼显示设备可以包括如下任意一种方案或方案的组合:本申请第一方面任意一种可能的实现方式提供的合光单元、本申请第二方面任意一种可能的实现方式提供的光机、本申请第四方面提供的光学组件、第六方面任意一种可能的实现方式提供的光波导、第八方面任意一种可能的实现方式提供的光波导、第十一方面任意一种可能的实现方式提供的光波导、第十三方面任意一种可能的实现方式提供的光波导、第十五方面任意一种可能的实现方式提供的光波导、第十八方面任意一种可能的实现方式所述的光波导、第十九方面任意一种可能的实现方式所述的光波导、第二十五方面任意一种可能的实现方式所述的光波导。
本申请第三方面、第五方面、第七方面、第九方面、第十方面、第十二方面、第十四方面、第十六方面、第二十方面、第二十六方面提供的近眼显示设备,均可以包括第二十八方面任意一种可能的实现方式所述的光波导。
第三十方面,本申请提供一种光波导,光波导包括依次层叠设置光波导主体、第一减反层、填充主体层、第二减反层和表面保护层,所述第一减反层位于在所述光波导主体和所述填充主体层之间,所述填充主体层的折射率和空气的折射率之间的差在第一预设范围内,所述第二减反层位于所述填充主体层和所述表面保护层之间,所述第二减反层的折射率呈渐变趋势变化,所述第二减反层与所述填充主体层邻近的部分的折射率和所述填充主体层之间的折射率差在第二预设范围内,所述第二减反层与所述表面保护层邻近的部分的折射率和所述表面保护层之间的折射率差在第二预设范围内。
本申请通过在光波导主体和表面保护层之间设置填充主体层,能够实现对光波导主体和表面保护层的支撑和保护,避免光波导主体受环境因素影响光学性能。
由于填充主体层的折射率较小,例如接近空气,填充主体层的折射率和表面保护层的折射率之间存在折射率差,填充主体层的折射率和光波导主体之间的折射率之间亦存在折射率差,若不设置第一减反层和第二减反层,在填充主体层和光波导主体之间连接的位置及在填充主体层和表面保护层之间的连接位置均会有光线反射,此反射影响光波导的透过率。因此,本申请通过设置第一减反层和第二减反层实现光波导整体的减反射效果
具体而言,第一减反层可以为镀膜的方式形成在光波导主体的表面,通过光干涉原理实现光波导主体的全反射,第一减反层可以改善光波导界面处的散射吸收问题,增加该界面处的减反增透效果。
一种实施方式中,对于第一减反层而言,可以为单层膜层架构,此情况下,第一减反层的折射率跟上下两个界面的介质折射率相关,估算为两者乘积开平方,第一减反层的厚度为入射波长的1/4。第一减反层也可以为多层膜结构,若为多层膜结构,要求多层膜层的等效折射率为上述值,才能达到界面处反射率较低(理论上减为0),起到该表面处减反的作用。
第二减反层具渐变的折射率的方案,在表面保护层和填充主体层之间形成梯度变化的折射率设计,解决表面保护层和填充主体层之间的光反射问题,提升光波导的透光性。
具体而言,一种可能的实现方式中,光波导主体表面可以形成用于传到光线的浮雕光栅,所以在光波导主体和表面保护层之间设置填充主体层还可以保护浮雕光栅不被剐蹭刮伤。
一种可能的实施方式中,所述填充主体层的折射率和空气的折射率之间的差在0.1~0.25之间,和/或,所述填充主体层的厚度在30~50μm之间。通过控制填充主体层的折射率和厚度,避免填充主体层的折射率过大,从而有利于控制光波导整体的折射率在合适的范围内,避免用户视力受损;并且此间厚度可以有效地实现对(光波导主体)晶圆的支撑,避免光波导过厚或过薄。
一种可能的实施方式中,所述填充主体层包括基底和折光介质,所述折光介质分散在所述基底内。制作填充主体层的材料中可以添加折光介质,然后通过上述实施方式中的制作方法制作填充主体层。基底的具体材质可以为上述中的硅氧烷聚合物。折光介质的具体形式不做限制,可以为颗粒状的微球,也可以是形成在填充主体层内的空心区域。举例而言,折光介质可以是颗粒材料,并且折光介质的折射率可以与基底的折射率不同。分散在基底内的遮光介质可以用于调节填充主体层的折射率,以使得填充主体层的折射率能够在上述实施方式的范围内。
一种可能的实施方式中,所述折光介质为树脂颗粒,所述树脂颗粒的折射率为1,和/或,所述树脂颗粒的粒径在0.1~100μm之间。使用树脂颗粒作为折光介质的原因是树脂颗粒具有较好的透光性,对可见光的透光性高。因此加入树脂颗粒到基底中,不会影响填充主体层的透光性。并且使用树脂颗粒作为折光介质还有利于填充主体层结构的稳定性,因为树脂颗粒与硅氧烷聚合物的化学性质相近,所以在填充主体层制作成型后,基底和折光介质之间不容易分离,基底和折光介质之间的粘合性更好,易于封装;然后通过调节折射率为1的树脂颗粒在基底内的含量和分布情况,从而达到控制填充主体层的折射率的目的;并且,控制树脂颗粒的粒径在上述范围内,有利于填充主体层的成型,且树脂颗粒的制造难度较低,易于工业化生产。当树脂颗粒的粒径小于上述范围时,树脂颗粒的尺寸过小,制造难度加大;当树脂颗粒的粒径大于上述范围时,树脂颗粒的尺寸过大,不利于填充主体层的成型。
一种可能的实施方式中,所述树脂颗粒为内部空心结构。具体地,树脂颗粒可以为核壳结构,其外壳为树脂材料成型,内核可以为空气。此设计的目的在于使得树脂颗粒的折射率能够更为接近空气。
一种可能的实施方式中,所述基底的折射率为1.4。基底的材质可以与第一减反层的材质相同的硅氧烷聚合物。使用与第一减反层的材质相同的硅氧烷聚合物的原因是,利用相同材质作为基底的填充主体层更容易与第一减反层粘合,能够避免由于材料不同而出现的层分离现象。并且,还可以减少更换材料的步骤,同种材料易于获取,有利于工业化生产和降低成本。
一种可能的实施方式中,所述填充主体层为气凝胶。通过以气凝胶为填充主体层,不但可以节省混合基底和折光介质的步骤,减少制备工艺;还可以降低填充主体层的制造成本。
一种可能的实施方式中,所述第二减反层的折射率在1.1~1.4之间,和/或,所述第二减反层的厚度在1~2μm之间。通过控制第二减反层的折射率和厚度,避免第二减反层的折射率过大,从而有利于控制光波导整体的折射率在合适的范围内,避免用户视力受损;并且此间厚度可以有效地实现对(光波导主体)晶圆的支撑,避免光波导过厚或过薄。
一种可能的实施方式中,所述第二减反层包括多个层叠设置的第二减反子层,任意相邻两层所述第二减反子层的折射率之间的差在预设范围内。通过将第二减反层设计为多个第二减反子层的方式,有利于第二减反层的分步多次制备,提高第二减反层的成型精度,并且第二减反子层的折射率不全相同,有利于通过多种不同的折射率逐步减少光线反射。
一种可能的实施方式中,自所述光波导主体至所述表面保护层的方向上,多个所述第二减反子层的折射率沿梯度递增。
一种可能的实施方式中,所述第二减反层和所述填充主体层的材料相同,密度不同;或,所述第二减反层和所述填充主体层通过同样的制作工艺形成。
一种可能的实施方式中,所述第一减反层通过镀膜的方式形成在所述光波导主体的表面。
第三十一方面,本申请还提供一种近眼显示设备,包括第三十方面任意一种可能的实现方式所述的光波导。
本申请第三十一方面提供的近眼显示设备可以包括如下任意一种方案或方案的组合:本申请第一方面任意一种可能的实现方式提供的合光单元、本申请第二方面任意一种可能的实现方式提供的光机、本申请第四方面提供的光学组件、第六方面任意一种可能的实现方式提供的光波导、第八方面任意一种可能的实现方式提供的光波导、第十一方面任意一种可能的实现方式提供的光波导、第十三方面任意一种可能的实现方式提供的光波导、第十五方面任意一种可能的实现方式提供的光波导、第十八方面任意一种可能的实现方式所述的光波导、第十九方面任意一种可能的实现方式所述的光波导、第二十五方面任意一种可能的实现方式所述的光波导、第二十八方面任意一种可能的实现方式所述的光波导。
本申请第三方面、第五方面、第七方面、第九方面、第十方面、第十二方面、第十四方面、第十六方面、第二十方面、第二十六方面、第二十九方面提供的近眼显示设备,均可以包括第三十方面任意一种可能的实现方式所述的光波导。
第三十二方面,本申请还提供一种光波导的制备方法,包括:在光波导主体上制作第一减反层,使得所述第一减反层和所述光波导主体叠设置;在所述第一减反层背离所述光波导主体的一侧制作填充主体层;在所述填充主体层背离所述第一减反层的一侧制作第二减反层,所述第二减反层的折射率呈渐变趋势变化;在所述第二减反层背离所述填充主体层的一侧制作表面保护层。本申请通过上述制备方法制备的光波导,能够利用填充在光波导主体和表面保护层之间的填充主体层实现对光波导主体和表面保护层的支撑和保护;同时,利用第一减反层可以改善光波导主体在界面处的散射吸收问题,增加该界面处的减反增透效果, 利用第二减反层具渐变的折射率的方案,在表面保护层和填充主体层之间形成梯度变化的折射率设计,解决表面保护层和填充主体层之间的光反射问题,提升光波导的透光性。
一种可能的实施方式中,在所述第一减反层背离所述光波导主体的一侧制作填充主体层的步骤包括:在基底材料中加入折光介质,并均匀混合得到填充主体材料;通过多次匀胶法、或辊涂超声喷雾法、或空气喷雾法、或提拉法在所述第一减反层上涂覆所述填充主体材料;将所述填充主体材料固化,得到所述填充主体层。
一种可能的实施方式中,在基底材料中加入折光介质的步骤包括:将折光材料加入分散液中,并均匀混合;通过喷雾造粒法将所述折光材料制作得到所述折光介质,所述折光介质的粒径在0.1~100μm之间。喷雾干燥相比于普通干燥而言,多了造粒的功能,能一定程度减小成品颗粒尺寸且形貌相对规整。
一种可能的实施方式中,在所述第一减反层背离所述光波导主体的一侧制作填充主体层的步骤包括:在溶剂中加入硅源材料,并涂覆在所述第一减反层上;通过酸碱两步法和酒精超临界干燥法将所述硅源材料固化,得到所述填充主体层。上述步骤的目的在于,以气凝胶作为填充主体层,并且气凝胶中气孔可调的特性,通过超临界干燥法在第一减反层上制作出具有符合折射率要求的气凝胶,相对于上述实施方式中的基底和折光介质,制作气凝胶的步骤简单,且材料成本较低。
一种可能的实施方式中,在所述填充主体层背离所述第一减反层的一侧制作第二减反层的步骤包括:在所述填充主体层背离所述第一减反层的一侧制作多个层叠设置的第二减反子层,自所述光波导主体至所述表面保护层的方向上,多个所述第二减反子层的折射率沿梯度递增。多个第二减反子层可以通过分步制作的方式逐个制作,并且可以通过调节制作第二减反子层的原料属性,从而获得不同折射率的第二减反子层。
一种可能的实施方式中,在所述填充主体层背离所述第一减反层的一侧制作多个层叠设置的第二减反子层的步骤包括:在基底材料中加入折光介质,并均匀混合得到填充主体材料;将所述填充主体材料和所述基底材料按预设比例混合后得到多组第二减反材料,多组所述第二减反材料的折射率不同;在所述填充主体层上依次涂覆并固化多组所述第二减反材料,得到多个层叠设置的所述第二减反子层。以上述步骤所提供的方法制作第二减反子层,其特点在于可以利用上述实施方式中所提供的填充主体材料,辅以不同比例的基底材料,从而调配出多种不同折射率的第二减反材料,优势在于无需新增配料,利用填充主体层的现有材料即可继续制备,且无需改动工艺生产线,适用于大批量生产,成本可控。
一种可能的实施方式中,在所述填充主体层背离所述第一减反层的一侧制作多个层叠设置的第二减反子层的步骤包括:在溶剂中加入硅源材料,得到多组第二减反材料,多组所述第二减反材料中所述硅源材料和所述溶剂的体积比不同;在所述填充主体层上依次涂覆并固化多组所述第二减反材料,得到多个层叠设置的所述第二减反子层。以上述步骤所提供的方法制作第二减反子层,其特点在于可以利用上述实施方式中所提供的填充主体材料,辅以不同比例的硅源材料,即可以通过不同浓度配比的第二减反材料制作出多种孔隙率的气凝胶,优势在于无需新增配料,利用填充主体层的现有材料即可继续制备,且无需改动工艺生产线,适用于大批量生产,成本可控。
第三十三方面,本申请提供一种光波导,应用于近眼显示设备,包括第一波导基底和形成在所述第一波导基底的表面的第一光栅结构,所述第一波导基底用于光路的全反射,所述第一波导基底和所述第一光栅结构均呈柔性,所述光波导具有变形特性,以使得所述光波导能够适配所述近眼显示设备的不同曲率的镜片。本实施方式中,第一波导基底和第一光栅结构均呈柔性,可以理解为光波导中所有的结构均为柔性,以使光波导可以任意弯曲,以匹配不同曲率的镜片,实现镜片的轻薄化,带来近眼显示设备的轻量化。
一种可能的实施方式中,所述第一波导基底的折射率大于等于1.6,所述第一波导基底的厚度小于300um。本方案通过限制第一波导基底的折射率和厚度,使得第一波导基底的设置能够满足光在其中进行全反射传播,具有较好的光学性能的基础上,保证薄型化设计。将第一波导基底的厚度设置在300um以内,再配合第一波导基底的材质的限定,能够提升柔性性能。
一种可能的实施方式中,所述第一波导基底的材料为柔性玻璃或柔性光学树脂材料。本方案通过限制第一波导基底的材料,约束第一波导基底的柔性性能。
一种可能的实施方式中,所述第一光栅结构一体成型在所述第一波导基底中。例如,第一光栅结构通过刻蚀工艺形成在第一波导基底的表面。本实施方式提供的光波导中,第一光栅结构直接制作在第一波导基底上,不需要额外设置制作光栅的材料层,第一光栅结构和第一波导基底为一体式的结构,结构稳定性更好,易于调制衍射效率,及保持光学性能。
一种可能的实施方式中,所述第一光栅结构通过刻蚀工艺形成在所述第一波导基底的表面。
一种可能的实施方式中,所述第一光栅结构形成于第一光栅层上,所述第一光栅层和所述第一波导基底层叠设置,所述第一光栅层呈柔性,所述第一光栅层材料为压印胶。
一种可能的实施方式中,所述第一光栅层的厚度为:大于等于0.2um小于等于1.2um,所述第一光栅层的折射率大于等于1.6。本方案通过约束第一光栅层的厚度范围及折射率范围,保证其柔性性能,本方案可以通过折射率不同的设置来调制衍射效率。
一种可能的实施方式中,所述光波导还包括第一调制层,所述第一调制层和所述第一波导基底层叠设置,且部分所述第一调制层填充在所述第一光栅结构中,所述第一调制层的折射率和所述第一光栅结构折射率之间的差值大于等于0.1。本方案通过在光波导的光栅所在的面上增设第一调制层,一方面,第一调制层将第一光栅结构遮盖,第一调制层用于保护第一光栅结构。另一方面第一调制层也能够调制光波导的衍射效率,可以使得光波导的衍射效率符合使用场景的需求,使光波导能够适用较多的场景。
一种可能的实施方式中,所述第一调制层的折射率小于所述第一光栅结构的折射率。
具体而言,所述第一调制层的折射率大于等于1.9。本方案主要是为了调节第一光栅结构的衍射效率,因为第一调制层与第一光栅结构有折射率差(折射率差大于等于0.1),所以衍射效率会发生变化,为了保证第一调制层与第一光栅结构之间的折射率差,可以将第一调制层的折射率约束在大于等于1.9的范围内。
一种可能的实施方式中,所述第一调制层的折射率大于所述第一光栅结构的折射率。
具体而言,本方案主要是为了调节第一光栅结构的衍射效率,因为第一调制层与第一光栅结构有折射率差(折射率差大于等于0.1),所以衍射效率会发生变化,为了保证第一调制层与第一光栅结构之间的折射率差,可以将第一调制层的折射率约束在小于等于1.6的范围内。
一种可能的实施方式中,所述第一调制层背离所述第一光栅结构的表面设有第一辅助光栅结构,所述第一辅助光栅结构用于光线的调制。第一辅助光栅结构可以为耦入光栅、中继光栅或耦出光栅。
一种可能的实施方式中,所述光波导还包括第二光栅结构,所述第一光栅结构和所述第二光栅结构分别位于所述第一波导基底相对的两侧。本方案限定了一种双面光波导架构,通过第一光栅结构和第二光栅结构结合提升光波导的衍射效率。
一种可能的实施方式中,所述光波导还包括第二调制层,所述第二调制层和所述第一波导基底层叠设置,且部分所述第二调制层填充在所述第二光栅结构中,所述第二调制层的折射率和所述第二光栅结构的折射率之间的差值大于0.1。
一种可能的实施方式中,所述光波导还包括第二波导基底、光限制层和第三光栅结构,所述第二波导基底用于光路的全反射,所述第二波导基底呈柔性,所述光限制层层叠设置在所述第一波导基底和所述第二波导基底之间,所述光限制层亦呈柔性且透明状,所述光限制层的折射率低于所述第一波导基底的折射率,也低于所述第二波导基底的折射率,所述光限制层用于保证所述第一波导基底和所述第二波导基底各自的全反射,所述第三光栅结构形成在所述第二波导基底上。本方案提供一种多层光波导架构,通过限制层将双层架构之间隔开保证每一层的独立工作。
一种可能的实施方式中,所述光限制层的厚度小于等于100um。本方案将光限制层的厚度控制在小于等于100um,有利于控制光波导的薄型化,使光波导形成薄膜式架构,与弯曲的镜片表面贴合的过程,能够具有较好的贴合度。
一种可能的实施方式中,所述光波导还包括柔性衬底层,所述柔性衬底层和所述第一波导基底层叠设置,且位于所述第一波导基底的背离所述第一光栅结构的一侧,所述柔性衬底层呈透明状且折射率低于所述第一波导基底的折射率,所述柔性衬底层用于与所述近眼显示设备的镜片贴合。本方案通过在第一波导基底上增设一层柔性衬底层,通过柔性衬底层与镜片贴合,可以避免第一波导基底直接与镜片贴合,若第一波导基底直接与镜片贴合,贴合用的胶水可能会影响第一波导基底的光学参数,柔性衬底层能够第一波导基底形成保护,以保证光波导的光学性能。
第三十四方面,本申请提供一种光波导的制作方法,用于制作第三十三方面任意一项可能的实现方式提供所述的光波导,所述制作方法包括:
提供硬质基底,所述硬质基底包括制作平面;
在所述制作平面上形成一层牺牲层;
在所述牺牲层上制作所述光波导;
溶解所述牺牲层,得到所述光波导。
一种可能的实施方式中,在所述牺牲层上制作所述光波导的步骤包括:
在所述牺牲层上设置第一波导基底,所述第一波导基底的折射率大于等于1.6,所述第一波导基底的厚度小于300um;
在所述第一波导基底上制作第一光栅结构。
一种可能的实施方式中,在所述牺牲层上制作光波导的步骤包括:
提供光波导中间结构,所述光波导中间结构呈柔性,且包括第一波导基底和形成在第一波导基底的表面的第一光栅结构;
将所述光波导中间结构设置在所述牺牲层上,所述第一光栅结构和所述牺牲层充分接触;
在所述第一波导基底背离所述第一光栅结构的一侧制作第二光栅结构。
一种可能的实施方式中,在所述牺牲层上制作光波导的步骤包括:
在所述牺牲层上设置第一波导基底,所述第一波导基底用于光路的全反射,所述第一波导基底呈柔性;
在所述第一波导基底上制作第一光栅结构;
在所述第一光栅结构上形成光限制层,所述光限制层亦呈柔性且透明状,所述光限制层的折射率低于所述第一波导基底的折射率;
在所述光限制层上制作第二波导基底,所述第二波导基底用于光路的全反射,所述第二波导基底呈柔性;
在所述第二波导基底上制作第三光栅结构。
本申请提供的光波导的制作方法利用了平面制作工艺,在硬质基底和牺牲层上制作光波导,容易实现批量化的生产。再利用牺牲层的属性,将牺牲层熔解,使得硬质基底脱离,就形成了柔性的光波导。本申请提供的光波导的制作方法,易于加工,制作成本低,能够生产的同时还能保护光波导的柔性性能。特别是可以使用纳米压印工艺大规模制备具有表面浮雕光栅的柔性的光波导。
第三十五方面,本申请提供一种近眼显示设备,包括镜片和第三十三方面任意一种可能的实现方式提供的所述的光波导,所述镜片包括曲面部分,所述光波导贴合至所述镜片的所述曲面部分的表层或中间层。
本申请第三十五方面提供的近眼显示设备可以包括如下任意一种方案或方案的组合:本申请第一方面任意一种可能的实现方式提供的合光单元、本申请第二方面任意一种可能的实现方式提供的光机、本申请第四方面提供的光学组件、第六方面任意一种可能的实现方式提供的光波导、第八方面任意一种可能的实现方式提供的光波导、第十一方面任意一种可能的实现方式提供的光波导、第十三方面任意一种可能的实现方式提供的光波导、第十五方面任意一种可能的实现方式提供的光波导、第十八方面任意一种可能的实现方式所述的光波导、第十九方面任意一种可能的实现方式所述的光波导、第二十五方面任意一种可能的实现方式所述的光波导、第二十八方面任意一种可能的实现方式所述的光波导、第三十方面任意一种可能的实现方式所述的光波导。
本申请第三方面、第五方面、第七方面、第九方面、第十方面、第十二方面、第十四方面、第十六方面、第二十方面、第二十六方面、第二十九方面、第三十一方面提供的近眼显示设备,均可以包括第三十三方面任意一种可能的实现方式所述的光波导。
附图说明
图1为本申请一种实施方式提供的近眼显示设备的示意图。
图2为本申请一种实施方式提供的近眼显示设备的示意图。
图3为图1所示的实施方式或图2所示的实施方式的另一个方向的示意图。
图4为本申请一种实施方式提供的近眼显示设备的平面示意图。
图5为本申请一种实施方式提供的光机的示意图。
图6为本申请一种实施方式提供的合光单元的立体示图。
图7为图6所示的合光单元的立体分解图。
图8为图6所示的合光单元的一种状态的分解图。
图9为图6所示的合光单元的一种状态的分解图。
图10A为本申请一种实施方式提供的光机的立体示意图。
图10B为图10A提供的实施方式中第二波长范围发射单元的光路示意图。
图10C为一种实施方式提供的光波导的示意图。
图11为本申请一种实施方式提供的光机的立体示意图。
图12为本申请一种实施方式提供的光机的立体示意图。
图13为本申请一种实施方式提供的合光单元的立体示图。
图14为图13所示的合光单元的立体分解图。
图15为图13所示的合光单元的一种状态的立体分解示意图。
图16为图13所示的合光单元的一种状态的立体分解示意图。
图17为图13所示的合光单元的一种状态的立体分解示意图。
图18为图13所示的合光单元的一种状态的立体分解示意图。
图19为本申请一种实施方式提供的光机的立体示意图。
图20为图19所示的光机的一个方向的平面图。
图21为图19所示的光机中的合光单元和发光单元的分解示意图。
图22为本申请一种实施方式提供的光学组件的示意图。
图23为图22所示的光学组件所产生的鬼像问题的示意图。
图24A和图24B为本申请一种实施方式提供的光学组件的示意图,图24A和图24B分别显示了发光单元上的B1位置和B2位置发出的光线,经过耦入光栅反射的示意图。
图25A和图25B为本申请一种实施方式提供的光学组件的示意图,图25A和图25B分别显示了发光单元上的B1位置和B2位置发出的光线,经过耦入光栅反射的示意图。
图26A和图26B为本申请一种实施方式提供的光学组件的示意图,图26A和图26B分别显示了发光单元上的B1位置和B2位置发出的光线,经过耦入光栅反射的示意图。
图27A和图27B为本申请一种实施方式提供的光学组件的示意图,图27A和图27B分别显示了发光单元上的B1位置和B2位置发出的光线,经过耦入光栅反射的示意图。
图28示意性地描述了三种附加结构和波导主体结构之间的位置关系。
图29示意性地描述了光机视场角的参数。
图30为本申请一种实施方式提供的光波导的示意图。
图31为二维光栅将光分为8个传播方向的示意图。
图32为图31所示的光波导的耦出光效率图。
图33为本申请一种实施方式提供的光波导的示意图。
图34为本申请一种实施方式提供的光波导的示意图。
图35为本申请一种实施方式提供的光波导的示意图。
图36为本申请一种实施方式提供的光波导的示意图。
图37为本申请一种实施方式提供的光波导的示意图。
图38为本申请一种实施方式提供的光波导的示意图。
图39为本申请一种实施方式提供的光波导的示意图。
图40为本申请一种实施方式提供的光波导的示意图。
图41为本申请一种实施方式提供的光波导的示意图。
图42A为本申请一种实施方式提供的光波导的示意图。
图42B为本申请一种实施方式提供的光波导的示意图。
图43为本申请提供的光波导产生的虚像面上的虚拟图像对应的虚像距和视距差的三种不同的配置的示意图。
图44为本申请一种实施方式提供的光波导的耦出光栅形成眼动空间的示意图。
图45为宽光束成像形成VAC现象的光路原理图。
图46为细光束成像解决VAC问题的光路原理图。
图47为本申请一种实施方式提供的光波导的示意图,光波导中的耦出光栅包括多个子光栅的架构。
图48为图47所示的光波导的耦出光栅的示意图。
图49A为本申请一中种实施方式提供的两个子光栅的具体的结构形态。
图49B为本申请一中种实施方式提供的两个子光栅的具体的结构形态。
图50为本申请一种实施方式提供的光波导的示意图,光波导中的耦出光栅包括多个子光栅的架构。
图51为一种实施方式提供的光波导,在波导基底的正反两面均设置光栅结构的示意图。
图52为图51中的波导基底的正面的光栅结构的示意图。
图53为图51中的波导基底的反面的光栅结构的示意图。
图54为本申请一中种实施方式提供的两个子光栅的示意图。
图55为本申请一种实施方式提供的光波导的耦出光栅的示意图。
图56为本申请一种实施方式提供的光波导的示意图。
图57为本申请一种实施方式提供的近眼显示设备的示意图。
图58为图57所示的近眼显示设备中的控制单元和耦出光栅之间控制架构的示意图。
图59为图57和图58所示的实施方式中的耦出光栅的架构。
图60为图59所示的耦出光栅的一种工作状态的子光栅分布架构示意图。
图61为本申请一种实施方式提供的光波导的示意图。
图62为图61中部分光栅结构和部分波导基底的分解示意图。
图63为本申请一种实施方式提供的光波导的光栅结构的端面的示意图。
图64为对比正弦渐变折射率分布的光栅结构和单独芯结构的光栅结构的入射角和衍射效率对应关系的曲线示意图。
图65为本申请一种实施方式提供的光波导的部分光栅结构和部分波导基底的分解示意图。
图66为本申请一种实施方式提供的光波导中的光栅结构中的第二膜层的示意图。
图67为在波导基底上制作芯结构的示意图。
图68为在图67所示的结构的基础上完成光栅结构制作的三个步骤的示意图。
图69为本申请一种实施方式提供的光波导的波导基底上的芯结构和膜结构的示意图。
图70为本申请一种实施方式提供的光波导的波导基底上的光栅结构的示意图。
图71为本申请一种实施方式提供的光波导的立体示意图。
图72为本申请一种实施方式提供的光波导的平面示意图。
图73为本申请一种实施方式提供的光波导的平面示意图。
图74为本申请一种实施方式提供的光波导的平面示意图。
图75为本申请一种实施方式提供的光波导的示意图。
图76为本申请一种实施方式提供的光波导的光栅周期的K空间示意图。
图77为本申请一种实施方式提供的光波导的光栅周期的K空间示意图。
图78为本申请一种实施方式提供的光波导的示意图。
图79为本申请一种实施方式提供的光波导的示意图。
图80为本申请一种实施方式提供的光波导的单光栅衍射效率示意图。
图81为本申请一种实施方式提供的光波导的波长带宽的示意图。
图82为本申请一种实施方式提供的光波导的角度带宽的示意图。
图83为本申请一种实施方式提供的光波导的第一光栅层或第二光栅层制作过程中的多次曝光的制作流程示意图。
图84为本申请一种实施方式提供的光波导的示意图。
图85为本申请一种实施方式提供的光波导的示意图。
图86为本申请一种实施方式提供的光波导的示意图。
图87为本申请一种实施方式提供的光波导的示意图。
图88为本申请一种实施方式提供的光波导的示意图。
图89为本申请一种实施方式提供的光波导的示意图。
图90为图89中I部分的放大示意图。
图91为本申请一种实施方式提供的光波导的示意图。
图92为本申请一种实施方式提供的光波导中的增透层和耦出光栅构成共体结构的示意图。
图93为本申请一种实施方式提供的光波导中的增透层和耦出光栅构成共体结构的示意图。
图94为本申请一种实施方式提供的光波导的示意图。
图95为形成增透层与光栅结构构成的共体结构的具体的制作方法的示意图。
图96为本申请一种实施方式提供的光波导的制作方法的流程图。
图97为本申请一种实施方式提供的光波导的制作方法的过程中,材料层进行双光束曝光过程中,各组分的变化示意图。
图98为本申请一种实施方式提供的光波导的示意图。
图99为本申请一种实施方式提供的光波导的示意图。
图100为本申请一种实施方式提供的光波导的示意图。
图101为本申请一种实施方式提供的光波导的示意图。
图102为本申请一种实施方式提供的光波导的示意图。
图103为本申请一种实施方式提供的光波导的示意图。
图104为本申请一种实施方式提供的光波导的示意图。
图105为本申请一种实施方式提供的光波导的示意图。
图106A为本申请一种实施方式提供的光波导的示意图。
图106B为本申请一种实施方式提供的光波导的示意图。
图106C为本申请一种实施方式提供的光波导的示意图。
图107为本申请一种实施方式提供的光波导的示意图。
图108为本申请一种实施方式提供的光波导的示意图。
图109为本申请一种实施方式提供的光波导的制作方法的流程示意图。
图110为本申请一种实施方式提供的光波导的制作方法的流程示意图。
图111为本申请一种实施方式提供的光波导的制作方法的流程示意图。
图112为本申请一种实施方式提供的光波导的制作方法的流程示意图。
图113为本申请一种实施方式提供的光波导的剖视结构示意图。
图114为本申请一种实施方式提供的光波导的剖视结构示意图。
图115为本申请一种实施方式提供的光波导的剖视结构示意图。
图116为本申请一种实施方式提供的光波导的剖视结构示意图。
图117为本申请一种实施方式提供的光波导的剖视结构示意图。
图118A为本申请一种实施方式提供的光波导的剖视结构示意图。
图118B为本申请一种实施方式提供的光波导的剖视结构示意图。
图118C为本申请一种实施方式提供的光波导的剖视结构示意图。
图119为本申请一种实施方式提供的光波导的剖视结构示意图。
图120为本申请一种实施方式提供的光波导的剖视结构示意图。
图121为本申请一种实施方式提供的光波导的剖视结构示意图。
图122为本申请一种实施方式提供的光波导的平面示意图。
图123为图122所示光波导在A-A处的剖视结构示意图。
图124为图122所示光波导在A-A处的另一种剖视结构示意图。
图125为本申请一种实施方式提供的光波导的平面示意图。
图126为图125所示光波导在B-B处的剖视结构示意图。
图127为图125所示光波导在B-B处的另一种剖视结构示意图。
图128为本申请一种实施方式提供的光波导的示意图。
图129为本申请一种实施方式提供的光波导各层的结构爆炸示意图。
图130为光线在图129所示的光波导中传播的光路示意图。
图131为图129所示的光波导得第一区域和第二区域的划分示意图。
图132为本申请一种实施方式提供的第一光栅层的结构示意图。
图133为第一光栅层在其他一些实施方式中的结构示意图。
图134为本申请一种实施方式提供的第二光栅层的结构示意图。
图135为第二光栅层在其他一些实施方式中的结构示意图。
图136为第二光栅层在其他一些实施方式中的结构示意图。
图137为由图133中第一光栅层和图135中第二光栅层组成的光波导的结构示意图。
图138为由图132中第一光栅层和图136中第二光栅层组成的光波导的结构示意图。
图139为由图133中第一光栅层和图136中第二光栅层组成的光波导的结构示意图。
图140为本申请一种实施方式提供的光波导的制作方法流程图。
图141为图140中的步骤S1中第一光栅层的制备示意图。
图142为图140中的步骤S2中光栅结构模板制作第二光栅层的步骤流程图。
图143为图142中的步骤S24中第二光栅层的制备示意图。
图144为图140中的步骤S2中光栅结构模板制作第二光栅层在其他实施方式中的步骤流程图。
图145为图144中的步骤S24中通过增粘层将光栅结构模板的第二光栅层粘接在第一光栅层上的制备示意图。
图146为本申请一种实施方式提供的光波导的示意图。
图147为本申请一种实施方式提供的光波导各层级结构的截面示意图。
图148为图147中的光波导各层级结构的爆炸示意图。
图149为本申请一种实施方式提供的填充主体层为基底和折光介质的截面示意图。
图150为本申请一种实施方式提供的填充主体层为气凝胶的截面示意图。
图151为本申请一种实施方式提供的第二减反层并分为多个第二减反子层的截面示意图。
图152为图151中包括四个第二减反子层的截面示意图。
图153为本申请另一种实施方式提供的第二减反层并分为多个第二减反子层的截面示意图。
图154为本申请一种实施方式提供的填充主体层和第二减反层的截面示意图。
图155为本申请另一种实施方式提供的填充主体层和第二减反层的截面示意图。
图156为本申请一种实施方式提供的包括增粘层的光波导的截面示意图。
图157为本申请一种实施方式提供的光波导的制备方法流程图。
图158为图157步骤S2中填充主体层的制备示意图。
图159为图158步骤S21中折光介质的制备示意图。
图160为图157步骤S2中填充主体层的制备步骤流程图。
图161为图157步骤S2中另一种填充主体层的制备示意图。
图162为图157步骤S2中另一种填充主体层的制备步骤流程图。
图163为图157步骤S3中第二减反层的制备示意图。
图164为图157步骤S3中第二减反层的制备步骤流程图。
图165为图157步骤S3中另一种第二减反层的制备示意图。
图166为本申请一种实施方式提供的光波导的示意图。
图167为图166所示的光波导与近眼显示设备的镜片结合的示意图。
图168为本申请一种实施方式提供的光波导的示意图。
图169为本申请一种实施方式提供的光波导的示意图。
图170为本申请一种实施方式提供的光波导的示意图。
图171为本申请一种实施方式提供的光波导的示意图。
图172A为本申请一种实施方式提供的光波导的示意图。
图172B为本申请一种实施方式提供的光波导的示意图。
图173A为本申请一种实施方式提供的光波导的示意图。
图173B为本申请一种实施方式提供的光波导的示意图。
图173C为本申请一种实施方式提供的光波导的示意图。
图174A为本申请一种实施方式提供的光波导的示意图。
图174B为本申请一种实施方式提供的光波导的示意图。
图175A为本申请一种实施方式提供的光波导的示意图。
图175B为本申请一种实施方式提供的光波导的示意图。
图175C为本申请一种实施方式提供的光波导的示意图。
图176A为本申请一种实施方式提供的光波导的示意图。
图176B为本申请一种实施方式提供的光波导的示意图。
图177为本申请一种实施方式提供的光波导的示意图。
图178A为本申请一种实施方式提供的光波导的示意图。
图178B为本申请一种实施方式提供的光波导的示意图。
图178C为本申请一种实施方式提供的光波导的示意图。
图179A为本申请一种实施方式提供的光波导的制作方法的示意图。
图179B为本申请一种实施方式提供的光波导的制作方法的示意图。
图180A为本申请一种实施方式提供的光波导的制作方法的示意图。
图180B为本申请一种实施方式提供的光波导的制作方法的示意图。
具体实施方式
本申请以下实施例提供了一种近眼显示设备,该近眼显示设备可以包括但不限于AR设备。具体实施方式中,本申请提供的近眼显示设备为AR眼镜、头戴式设备等形态。接下来以近眼显示设备为AR眼镜为例对本申请的近眼显示设备进行描述。
图1为本申请一种实施方式提供的近眼显示设备的示意图,如图1所示,近眼显示设备1000包括结构件100和光学组件200。结构件100用于构建近眼显示设备1000的整体外形架构及安装内部光学器件和电子器件,光学组件200属于光学器件。结构件100包括镜框102和镜腿,镜腿包括右镜腿101和左镜腿103。右镜腿101和左镜腿103分别连接在镜框102的两侧,镜腿和镜框102之间的连接可以为转动连接,也可以为固定连接。当用户佩戴近眼显示设备1000时,镜框102位于用户双眼的前方,镜腿(右镜腿101和左镜腿103)则搭在用户的双耳处。结构件100的上述结构仅仅是一种举例,在其他实施例中可以根据需要进行设计,例如,结构件可以为头戴式显示设备的头箍或头盔等。
光学组件200包括镜片10和光机20,镜片10安装至镜框102且用于佩戴在人眼正前方。镜片10具有透光性,镜片10上具有光波导10A,例如,光波导10A可以为衍射光波导结构。一种实施方式中,镜片10上的所有区域均为光波导10A,即光波导10A构成近眼显示设备1000的镜片。其它实施方式中,光波导10A也可以只构成部分镜片10。光波导10A上具有耦入光栅11和耦出光栅12。光机20用于投射光线至光波导10A上,光机20将光线投射在耦入光栅11上,通过耦入光栅11将光线耦入光波导10A并在光波导10A内进行全反射,再经耦出光栅12射出,耦出光栅12将光线射出,以产生虚拟图像进入人眼。
图1所示的实施方式中,光机20位于左镜片10L和右镜片10R之间,且,光机20位于镜框102顶部的区域。光机20发出的光线包括两路光线,其中一路通过左镜片10L上的耦入光栅11进入左镜片10L上的光波导10A中,再通过左镜片10L上的耦出光栅12出射形成虚拟图像。光机20发出的另一路光线通过右镜片10R上的耦入光栅11进入右镜片10R上的光波导10A中,再通过右镜片10R上的耦出光栅12出射形成虚拟图像。图1所示的实施方式中,光机20和两个耦入光栅11均位于左镜片10L和右镜片10R交汇之处,即邻接区域。
图2为本申请另一种实施方式提供的近眼显示设备的示意图,如图2所示,此实施方式提供的近眼显示设备的结构件100和图1所示的实施方式的结构件100相同。图2所示的实施方式中,光学组件200中的光机20的数量为两个,这两个光机20分别位于两个镜腿和镜框连接的位置或附近位置。其中一个光机20位于左镜腿103和镜框102连接位置或者位于镜框10上靠近左镜腿103的位置,另一个光机20位于右镜腿101和镜框102连接位置或者位于镜框10上靠近右镜腿101的位置。其中一个光机20位于左镜片10L的左侧上方,另一个光机20位于右镜片10R的右侧上方。图2所示的实施方式中,两个耦入光栅11分别位于左镜片10L的左上角及右镜片10R的右上角。对于左镜片10L而言,光机20出射的光经过左镜片10L上的耦入光栅11进入左镜片10L上的光波导10A,再通过左镜片10L上的耦出光栅12出射形成虚拟图像。类似地,对于右镜片10R而言,光机20出射的光经过右镜片10R上的耦入光栅11进入右镜片10R上的光波导10A,再通过右镜片10R上的耦出光栅12出射形成虚拟图像。
图3为图1所示的实施方式或图2所示的实施方式的另一个方向的示意图。如图3所示,镜框102包围形成两个通光区域1021、1022,近眼显示设备1000在佩戴状态下,这两个通光区域1021、1022分别与左眼和右眼正对。具体而言,左镜片10L和右镜片10R分别和两个通光区域1021、1022对应设置。通光区域1021、1022包围的空间内为光波导10A(或部分光波导10A)。
图4为一种实施方式提供的近眼显示设备的平面示意图。如图4所示,近眼显示设备1000还包括电子组件300,一种实施方式中,电子组件300包括:控制器301、电池302、语音装置303、天线304、摄像头305等等。光机20的数量为两个,其中一个光机20位于右镜腿101的邻近镜片上的光波导10A的位置,另一个光机20位于左镜腿103的邻近镜片上的光波导10A的位置。一种实施方式中,控制器301的数量也可以为两个,其中一个控制器301位于左镜腿103内用于驱动安装在左镜腿103位置的光机20,另一个控制器301位于右镜腿101内用于驱动安装在右镜腿101位置的光机20。控制器301可以设置在近眼显示设备1000的主板上,可以为近眼显示设备1000的CPU,控制器301可以用于控制光机20的开关。一种实施方式中,电池302用于为近眼显示设备1000提供电源,电池302的数量也为两个,分别位于左镜腿103和右镜腿101上,电池302位于镜腿远离镜片的一端,方便充电。可以在镜腿上设置充电接口。 一种实施方式中,语音装置303和天线304的数量也都是两个,每个镜腿里都设一个语音装置303和一个天线304。天线304用于收发无线信号,例如,可以是WIFI、蓝牙或者移动通信信号。语音装置303可以用于输入或输出声音,例如麦克风或扬声器。一种实施方式中,摄像头305的数量为两个,其中一个摄像头305位于左镜片的左侧边缘位置,另一个摄像头305位于右镜片的右侧边缘位置,摄像头305可以与图像处理器连接,摄像头305用于拍摄影像,并传送至图像处理器,通过图像处理器处理影像信息。其它实施方式中,近眼显示设备1000还可以设置存储器、传感器、定位组件等电子组件,例如:存储器用于存储图像信息,传感器可以包括动力传感器(如陀螺仪)、生物传感器、温度传感器、湿度传感器等。定位组件可以包括GPS或北斗定位设备。
方案一:光机
一种实施方式中,本申请实施例提供一种光机,光机为自发光投影显示系统,光机为近眼显示设备的图像显示的光源,光机发射出的光路通过光波导的耦入光栅进入光波导后,再由光波导的耦出光栅将光线耦出至人眼,耦出的光线形成虚拟的图像,因此人眼能够看到虚拟的图像。一种实施方式中,光机为微显示全彩光机,这样可以形成彩色图像。
图5为本申请一种实施方式提供的光机的示意图。参阅图5,一种实施方式中,光机20包括发光单元21、合光单元22和光学成像单元23。发光单元21位于合光单元22的入光侧,光学成像单元23位于合光单元22的出光侧。发光单元21和控制器301电连接,控制器301可以控制发光单元21开关或与发光单元21之间进行数据传输。发光单元21为光机20的光源。所述合光单元22用于将发光单元21发出的单色光进行合光,形成混合光束,合光单元22发射混合光束至光学成像单元23,光学成像单元23用于接收从合光单元22出来的混合光束,混合光束经过光学成像单元23后出射至光波导10A的耦入光栅11上。光学成像单元23可以为透镜组,光学成像单元23的光轴23P可以为光机20的光轴。
图5所示的实施方式中,只是示意性地表达了光波导10A上的耦入光栅11,并不代表光波导10A和耦入光栅11的具体的结构形态。
一种具体的实施方式中,发光单元21包括第一波长范围发射单元211、第二波长范围发射单元212和第三波长范围发射单元213,第一波长范围发射单元211、第二波长范围发射单元212和第三波长范围发射单元213均可以为发光芯片,例如LED芯片。一种实施方式中,第一波长范围发射单元211为红光单元,例如红光LED。第二波长范围发射单元212为蓝光单元,例如蓝光LED。第三波长范围发射单元213为绿光单元,例如绿光LED。第一波长范围发射单元211、第二波长范围发射单元212和第三波长范围发射单元213分别对应设置在合光单元22的不同的入光面位置,可以理解为,第一波长范围发射单元211、第二波长范围发射单元212和第三波长范围发射单元213环绕合光单元22设置,第一波长范围发射单元211、第二波长范围发射单元212和第三波长范围发射单元213发出的光从不同的方向进入合光单元22。
结合参阅图4和图5,发光单元21和近眼显示设备1000中的控制器301电连接,控制器301用于开启或关闭发光单元21。图5所示的各元件之间的位置关系并不能表示任何一种实施方式提供的组装状态的发光单元21和合光单元22之间的位置关系,本申请通过将发光单元21中的第一波长范围发射单元211、第二波长范围发射单元212和第三波长范围发射单元213的位置挪移,使它们与合光单元22分离,使得图5形成为:发光单元21和合光单元22之间呈爆炸分解状态的示意图。
一种实施方式中,发光单元21包括第一柔性电路板214、第二柔性电路板215和第三柔性电路板216,所述第一柔性电路板214连接在所述第一波长范围发射单元211和所述控制器301之间,所述第二柔性电路板215连接在所述第二波长范围发射单元212和所述控制器301之间,所述第三柔性电路板216连接在所述第三波长范围发射单元213和所述控制器301之间。
图6为本申请一种实施方式提供的合光单元22的立体示图,如图6所示,合光单元22可以呈六面体结构,本申请用A、B、C、D、E、F、G、H表示合光单元22的八个顶点。合光单元22的外表面由六面体结构的六个外表面构成,一种实施方式中,其中四个外表面分别为第一入光面S1、第二入光面S2、第三入光面S3和出光面S4,另两个外表面为非入光面S5。一种实施方式中,如图6所示,第一入光面S1的四个顶点为A、B、C、D;第二入光面S2的四个顶点为B、C、E、H;第三入光面S3的四个顶点为C、D、F、E;出光面S4的四个顶点为E、F、G、H;其中一个非入光面S5的四个顶点为A、B、H、G;另一个非入光面S5的四个顶点为A、D、F、G。本申请并不限定各入光面的具体的位置,只要这三个入光面对应不同波长范围(或不同颜色)的发光单元,且能够保证从这三个入光面入射至合光单元的光线能够 在合光单元内合成一束混合光束且从出光面S4出射。
图6所示的实施方式提供的合光单元22为通过在一个立方体光学元件上沿两个对角面切割形成四个棱镜结构。例如,这两个对角面中的一个的四个顶点为C、D、G、H;这两个对角面中的另一个的四个顶点为B、C、F、G;这两个对角面的相交线为六面体结构的体对角线CG。
图7为图6所示的合光单元的立体分解图,从图7更清楚地看到四个棱镜结构具体结构形态。这四个棱镜结构分别为第一棱镜单元221、第二棱镜单元222、第三棱镜单元223和第四棱镜单元224,这四个棱镜结构均为异形棱镜,所述第一棱镜单元221、所述第二棱镜单元222、所述第三棱镜单元223和所述第四棱镜单元224均为一体式的棱镜结构,且四者共同拼接形成六面体架构。所述第一棱镜单元221和所述第三棱镜单元223为五面体结构(五面体棱镜),所述第二棱镜单元222和所述第四棱镜单元224为四面体结构(四面体棱镜)。一种具体的实施方式中,第一棱镜单元221包括五个顶点A、B、C、D、G,第一棱镜单元221的外表面由四个三角形表面和一个正方形表面构成;第二棱镜单元222包括四个顶点C、D、G、F,第二棱镜单元222的外表面由四个三角形表面构成;第三棱镜单元223包括五个顶点C、E、F、G、H,第三棱镜单元223的结构形态及尺寸均与第一棱镜单元221相同;第四棱镜单元224包括四个顶点B、C、H、G,第四棱镜单元224的结构形态及尺寸均与第二棱镜单元222相同。
一种实施方式中,在合光单元22的制作过程中,可以先提供一个六面体结构,再对这个六面体结构进行切割,即沿两个对角面进行切割,如图6所示,这两个对角面分别为第一对角面S67(第一对角面S67的四个顶点为C、D、G、H)和第二对角面S89(第二对角面S89的四个顶点为B、C、G、F)。切割后在相应的位置设置分光膜。一种实施方式中,也可以单独制作第一棱镜单元221、第二棱镜单元222、第三棱镜单元223和第四棱镜单元224,再将彼此独立的第一棱镜单元221、第二棱镜单元222、第三棱镜单元223和第四棱镜单元224拼接,且拼接过程与分光膜结合,就形成了合光单元。
图8为图6所示的合光单元的一种状态的分解图,如图8所示,第一棱镜单元221和第二棱镜单元222对接构成的对接架构呈五面体状,第三棱镜单元223和第四棱镜单元224对接构成的对接架构呈五面体状,这两个五面体状的对接架构均为六面体结构的一半。一种实施方式中,此六面体结构为立方体。所述第一棱镜单元221和所述第二棱镜单元222之间对接的位置为第一面S6,所述第三棱镜单元223和所述第四棱镜单元224之间的对接位置为第二面S7。如图8所示,第一面S6呈三角形,第一面S6的三个顶点为C、D、G;第二面S7呈三角形,第二面S7的三个顶点为C、H、G。
图9为图6所示的合光单元的一种状态的分解图,如图9所示,第一棱镜单元221和第四棱镜单元224对接构成的对接架构呈四面体状,第二棱镜单元222和第三棱镜单元223对接构成的对接架构呈四面体状,这两个四面体状的对接架构均为六面体结构的一半。所述第一棱镜单元221和所述第四棱镜单元224之间对接的位置为第三面S8,所述第二棱镜单元222和所述第三棱镜单元223之间的对接位置为第四面S9。如图9所示,第三面S8呈三角形,第三面S8的三个顶点为B、C、G;第四面S9呈三角形,第四面S9的三个顶点为C、G、F。
结合参阅图6、图8和图9,所述第一面S6和所述第二面S7构成所述六面体架构的第一对角面S67(第一对角面S67的四个顶点为C、D、G、H),所述第三面S8和所述第四面S9构成所述六面体结构的第二对角面S89(第二对角面S89的四个顶点为B、C、G、F),所述第一对角面S67和所述第二对角面S89之间的相交线L1为所述六面体结构的体对角线,相交线L1的两个顶点为C、G。
结合参阅图8和图9,所述第一面S6和所述第二面S7设置第一分光膜225,所述第三面S8和所述第四面S9设置第二分光膜226,图8中示意性地将顶点为B、C、G、F的长方形表示为第二分光膜226,图9中示意性地将顶点为C、D、G、H的长方形表示为第一分光膜225,一种实施方式中,第一分光膜225可以完全覆盖第一面S6和第二面S7,基它实施方式中,也可以根据需求调节第一分光膜225的尺寸和形状,例如第一分光膜225可以只覆盖第一面S6和第二面S7的部分区域,或者第一分光膜225的形状可以为其它形状(例如圆形、多边形等)。类似的,一种实施方式中,第二分光膜226可以完全覆盖第三面S8和第四面S9,其它实施方式中,也可以根据需求调节第二分光膜226的尺寸和形状,例如第二分光膜226可以只覆盖第三面S8和第四面S9的部分区域,或者第二分光膜226的形状可以为其它形状(例如圆形、多边形等)。第一分光膜225和第二分光膜226用于反射不同波长范围的光线。或者,第一分光膜225和第二分光膜226用于反射不同颜色的光线。本申请通过在这四个棱镜单元的对接面上设置分光膜,即在第一对角面S67上设置第一分光膜225,在第二对角面S89上设置第二分光膜226,第一分光膜225和第二分光膜226能够对不同波长范围的光线进行分光处理,使得三个不同波长范围的光线进入合光单元22后可以合光形成混合光束,并从出光面S4射出。一种实施方式中,不同波长范围的光线可以为不同颜色的 光线。
一种实施方式中,如图8所示,所述第二分光膜226包括两个子膜,具体而言,这两个子膜均呈三角形,分别为子膜BCG和子膜CGF。如图9所示,所述第一分光膜225为一体式的结构,即第一分光膜225为长方形的结构。本实施方式中,在拼接第一棱镜单元221和第四棱镜单元224的过程中将第二分光膜226的一个子膜BCG设置在第一棱镜单元221和第四棱镜单元224之间,在拼接第二棱镜单元222和第三棱镜单元223的过程中将第二分光膜226的一个子膜CGF设置在第二棱镜单元222和第三棱镜单元223之间。即构成图9所示的分解图状态,再将图9所示的分开的两部分棱镜组对接,对接的过程中,接第一分光膜225设置在对接位置。本方案设计的分光膜应用在由四块棱镜构成的合光单元中,由于第一分光膜225可以为一体式结构,具有结构简洁,组装方便的优势。
可以理解的是,其它实施方式中,第一分光膜225为两个子膜的架构,第二分光膜226为一体式结构。其它实施方式中,第一分光膜225和第二分光膜226均可以为两个子膜构成的架构。
图10A为本申请一种实施方式提供的光机20的立体示意图,图10A示意性地表达了图6所示的合光单元22在光机20中与发光单元21之间的具体的位置关系。如图10A所示,发光单元21包括第一波长范围发射单元211、第二波长范围发射单元212和第三波长范围发射单元213、第一柔性电路板214、第二柔性电路板215和第三柔性电路板216。第一波长范围发射单元211正对所述合光单元22的所述六面体结构的第一入光面S1(图10A中合光单元22的前侧面),所述第二波长范围发射单元212正对所述合光单元22的所述六面体结构的第二入光面S2(图10A中合光单元22的底面),所述第三波长范围发射单元312正对所述合光单元22的所述六面体结构的第三入光面S3(图10A中合光单元22的左侧面)。一种实施方式中,所述第一入光面S1、所述第二入光面S2和所述第三入光面S3两两相互垂直且相邻设置,三者分别对应六面体结构的三个彼此相邻的外表面。所述第一波长范围发射单元211的发光面的法线方向A1和所述第二波长范围发射单元212的发光面的法线方向A2均垂直于所述光机20的所述光学成像单元23的光轴23P,所述第三波长范围发射单元212的发光面的法线方向A3与所述光机20的所述光学成像单元23的光轴23P方向相同。
本实施方式中,所述第一分光膜225用于反射第一波长范围的光且透射第二波长范围的光及第三波长范围的光。一种实施方式中,所述第一分光膜225为反红透蓝绿膜层。第一波长范围发射单元211发出的所有的红色光线均会传送至第一分光膜225上,第一分光膜225反射红色光线,使得红色光线被反射后沿着光轴23P的方向射出出光面S4,并进入光学成像单元23。所述第二分光膜226用于反射第二波长范围的光且透射第一波长范围的光及第三波长范围的光。一种实施方式中,第二分光膜226为反蓝透红绿膜层,第二波长范围发射单元212发出的所有的蓝色光线均会传送至第二分光膜226上,第二分光膜226反射蓝色光线,使得蓝色光线被反射后沿着光轴23P的方向射出出光面S4,并进入光学成像单元23。第三波长范围发射单元213发出的绿色光线进入合光单元22后,会透过第一分光膜225和第二分光膜226,绿色光线沿着光轴23P的方向射出出光面S4,并进入光学成像单元23。三种颜色的光线均从出光面S4射出,且都沿着光轴23P的方向射出,以形成混合光束。
图10A所示的实施方式提供的光机20中的第二柔性电路板215的延伸方向和光轴23P的方向相近或相同,结合参阅图1、图2和图3,当光机20安装在近眼显示设备内时,第二柔性电路板215可以顺着结构件100延伸,不需要折叠第二柔性电路板215,即无弯折状顺着结构件延伸,有利于整机尺寸的减小。可以理解的是,若将柔性电路板折叠,光机整体的尺寸会因柔性电路板的折叠变大,在近眼显示设备中,就会占用更大的空间。
本申请提供的光机,由于包括前述合光单元,使得光机具有更灵活的配置方案,使光机可以配置在近眼显示设备中更多的环境。
图10A所示的实施方式提供的光机20安装至结构件的镜腿时,镜腿包括内侧面和外侧面,镜腿的内侧面为近眼显示设备在佩戴状态下贴近人脸的部分,外侧面则是近眼显示设备在佩戴状态下远离人脸的部分。一种实施方式中,本申请通过将第一波长范围发射单元211靠近镜腿的外侧面,合光单元22上的一个非入光面S5(具体为和第一入光面S1相对设置的非入光面S5)靠近镜腿的内侧面,这样的设置,使得近眼显示设备在靠近人脸的一侧不设置发光单元,能够降低用户感知到热的风险,提升用户使用的体验感。其它实施方式中,也可以将第二波长范围发射单元212靠近镜腿的外侧面设置,位于合光单元22的顶面的非入光面S5靠近镜腿的内侧面,一种实施方式中,图10A所示的实施方式提供的光机20安装至结构件的镜腿时,光机20的出光侧为近眼显示设备的镜片上的光波导。图10A所示的方式中,第二波长范围发射单元212位于合光单元22的底侧,可以使得光机出瞳处的蓝光能量上弱下强,光机20的具体架构与光 波导的结构搭配使用,可以使得光波导利用到较强部分的蓝光,提升光效。具体而言,第二波长范围发射单元212的摆放位置靠近光波导的中继区(即中继光栅),因此,本方案可以提升近眼显示设备的光效。
对于合光单元22而言,可以理解为合光单元22由棱镜构成,棱镜上设置光学膜层,例如第一分光膜和第二分光膜,由于各膜层的透过率或反射率在不同入射角的时候有差异,例如:入射到分光膜(即棱镜的分光斜面)上的角度越大,光效越低。角度指光线与分光膜的法线的夹角。故在光机出瞳处的光强分布不均。图10B所示为图10A提供的实施方式中第二波长范围发射单元212的光路示意图。例如第二波长范围发射单元212发出的光为蓝色光线。第二波长范围发射单元212进入合光单元22且经过第二分光膜226进行反射,如图10B所示,第二分光膜226左下角部分反射的光线的角度较小,第二分光膜226右上角部分反射的光线的角度较大,右上角部分的光效较低。而且,经过第二分光膜226右上角部分反射的光线,经过光学成像单元23后,投影至耦入光栅11时,会有部分反射,反射回的光线在图10B中用虚线表示。由于第二波长范围发射单元212从光机出射的光线强度不均,导致在耦入光栅11上的光线强度也不均匀。耦入光栅11包括第一耦入区11C和第二耦入区11D,如图10B所示,一种实施方案发中,第一耦入区11C位于第二耦入区的上方。可以理解的是,图10B只是示意性地用矩形虚线框圈出第一耦入区11C和第二耦入区11D,实际应用中,第一耦入区11C和第二耦入区11D的具体的位置并不限于图10B所示的方案,第一耦入区11C和第二耦入区11D可以连接或部分重合。本申请只是借用图10B表达第一耦入区11C为入射光线能量较低的区域,第二耦入区11D为入射光线能量较强的区域。
本申请一种实施方式中,将第二波长范围发射单元212布置的位置,使得第二波长范围发射单元212投射光线的更多的能量集中至耦入光栅11的第二耦入区11D。参阅图10C,图10C为一种实施方式提供的光波导的示意图,表达了图10B中的耦入光栅11在光波导平面上与其它光栅之间的位置关系。具体而言,光波导10A包括耦入光栅11、中继光栅13和耦出光栅12。耦入光栅11的第二耦入区D邻近中继光栅13设置,即第一耦入区11C位于远离中继光栅13的一侧。这样,结合图10B和图10C,可以理解的是,第二波长范围发射单元212的更多的光的能量可以集中在第二耦入区11D,而由于第二耦入区11D和中继光栅13邻近,可以保证第二波长范围发射单元212投影至耦入光栅11上的光的能量得到较好的利用,更多的第二波长范围发射单元212的光能量能够进入中继光栅13,并通过耦出光栅12耦出至人眼。因此,本申请提供的光机的布置方向,结合耦入光栅11的布置能够提升第二波长范围发射单元212发送的光的利用率。
概括而言,光波导对于光机出瞳处的光并非全部利用,远离中继光栅的光线会重新反射回光机,形成鬼像。对于蓝光而言,由于蓝光波长短,衍射角度小,即全反射步长小,会有较多的光不能正常传播到中继光栅。因此,本申请可以将第二波长范围发射单元212(例如用于发射蓝色光的发光单元)摆放位置靠近光波导的中继区,能够提升整体光效。
图11为本申请一种实施方式提供的光机的立体示意图,图11所示的实施方式是在图10A所示的实施方式的基础上,将第二波长范围发射单元212和第一波长范围发射单元211交换位置。如图11所示,第一波长范围发射单元211位于合光单元22的底侧,第二波长范围发射单元212位于合光单元22的前侧。一种实施方式中,第一分光膜225为反蓝透红绿膜层,第二波长范围发射单元212发出的所有的蓝色光线均会传送至第一分光膜225上,第一分光膜225反射蓝色光线,使得蓝色光线被反射后沿着光轴23P的方向射出出光面S4,并进入光学成像单元23。第二分光膜226为反红透蓝绿膜层,第一波长范围发射单元211发出的所有的红色光线均会传送至第二分光膜226上,第二分光膜226反射红色光线,使得红色光线被反射后沿着光轴23P的方向射出出光面S4,并进入光学成像单元23。
图11所示的实施方式中,第一柔性电路板214的延伸方向和光轴23P的方向相近或相同,结合参阅图1、图2和图3,当光机20安装在近眼显示设备内时,第一柔性电路板214可以顺着结构件100延伸,不需要折叠第一柔性电路板214,有利于整机尺寸的减小。
图11所示的实施方式中,合光单元22的非入光面S5的位置与图10A所示的实施方式的非入光面S5的位置相同,均位于合光单元22的顶侧和背侧(背侧是与第一入光面S1相对的一侧)。图11所示的实施方式,可以将通过第二波长范围发射单元212或第一波长范围发射单元211放置在靠近镜腿外侧面的位置,以实现也能够保证近眼显示设备在靠近有脸的一侧不设置发光单元,降低用户感知到热的风险,提升用户使用的体验感。
图12为本申请一种实施方式提供的光机的立体示意图,本实施方式是在图10A所示的实施方式的基础上,将第二波长范围发射单元212的位置调整,将第二波长范围发射单元212放置至合光单元22的顶侧(图10A所示的实施方式中,第二波长范围发射单元212位于合光单元22的底侧)。如图12所示,为 了清晰显示合光单元的特征,将第二波长范围发射单元212连同第二柔性电路板215的位置从合光单元22的顶侧向上挪移,也就是说,图12所示的状态为第二波长范围发射单元212和合光单元22之间的分离状态,并不是组装好的光机的状态下的位置关系。图12所示的实施方式中,第二分光膜226的位置也做适应性的调整。一种实施方式中,第二分光膜226为反蓝透红绿膜层,第一分光膜225为反红透蓝绿膜层,具体的分光原理与图10A所示的实施方式相同。图12所示的实施方式中,第二柔性电路板215与第三柔性电路板216之间无交叉,使得二者在近眼显示设备的结构件内的布置可以更灵活。
图12所示的实施方式中,合光单元22的第二入光面S2位于合光单元22的顶侧,合光单元22的非入光面的位置为合光单元22的底侧和背侧(虽未标号,但容易理解是不设置发光单元的相应的表面),本实施方式中,可以通过将第二波长范围发射单元212或第一波长范围发射单元211放置在靠近镜腿外侧面的位置,以实现也能够保证近眼显示设备在靠近有脸的一侧不设置发光单元,降低用户感知到热的风险,提升用户使用的体验感。
一种实施方式中,为了保证第一波长范围发射单元211和第二波长范围发射单元212投射出的画面与第三波长范围发射单元213保持一致,需要将第一波长范围发射单元和第二波长范围发射单元的AA方向与第三波长范围发射单元对齐,即调整长边与短边的方向。通常,AA区是指activearea,即有效像素区,呈长方形,包括长边和短边。如图12中,第三波长范围发射单元213长边沿水平方向,短边沿竖直方向,则第一波长范围发射单元211长边方向与光轴平行,短边方向沿竖直方向,第二波长范围发射单元212长边垂直于光轴,短边平行于光轴。若AA区长边与短边长度相等,且像素个数相等,则第一波长范围发射单元211亦可将第一柔性电路板214顺着结构件100延伸。
第一波长范围发射单元211投射的画面、第二波长范围发射单元212投射出的画面与第三波长范围发射单元213投影的上画面保持一致,可以理解为,各发光单元所投影的图像经过合光单元转折后,形成的画面的方向是一致的。如图12所示,第一波长范围发射单元211投射的画面经合光单元后与第三波长范围发射单元213投影的上画面保持一致,同样,第二波长范围发射单元212投射的画面经合光单元后亦与第三波长范围发射单元213投影的上画面保持一致。
本申请提供的合光单元可以与发光单元灵活配置,例如,图10A、图11和图12提供的三种具体的实施方式均采用了图6所示的合光单元,可以通过调节第一波长范围发射单元和第二波长范围发射单元的位置,构成不同的配置方案。本申请只是示意性地列出了这三种具体实施方式,具体的应用过程中,不限于这三种具体的配置方案,配置方案可以具有更多的可能性。
图13为本申请一种实施方式提供的合光单元22的立体示图,如图13所示,合光单元22可以呈六面体结构,本申请用A、B、C、D、E、F、G、H表示合光单元22的八个顶点。合光单元22的外表面由六面体结构的六个外表面构成,一种实施方式中,其中四个外表面分别为第一入光面S1、第二入光面S2、第三入光面S3和出光面S4,另两个外表面为非入光面S5,其中一个非入光面S5和出光面S4相邻,另一个非入光面S5和出光面S4相对设置。一种实施方式中,如图13所示,第一入光面S1的四个顶点为A、D、F、G,即第一入光面S1为图13所示的六面体结构的顶侧面;第二入光面S2的四个顶点为B、C、E、H,即,第二入光面S2为图13所示的六面体结构的底侧面;第三入光面S3的四个顶点为C、D、F、E,即,第三入光面为图13所示的六面体结构的前侧面;出光面S4的四个顶点为E、F、G、H,即,出光面S4为图13所示的六面体结构的右侧面;其中一个非入光面S5(与出光面S4相邻设置的非入光面)的四个顶点为A、B、H、G;另一个非入光面S5的四个顶点为A、B、C、D。本申请并不限定各入光面的具体的位置,只要这三个入光面对应不同颜色的发光单元,且能够保证从这三个入光面入射至合光单元的光线能够在合光单元内合成一束混合光束且从出光面S4出射。
图13所示的实施方式为在图6所示的实施方式的基础上,再沿对角面切割一次。图6所示的实施方式为在六面体结构上分别沿第一对角面S67和第二对角面S89切割形成四个独立的棱镜单元,图13所示的实施方式为在六面体结构上分别沿着第一对角面S67、第二对角面S89和第三对角面S10切割形成八个棱镜结构。第一对角面S67和第二对角面S89之间的相交线L1为所述六面体结构的体对角线,相交线L1的两个顶点为C、G。第一对角面S67和第三对角面S10之间的相交线L2为所述六面体结构的体对角线,相交线L2的两个顶点为D、H。第二对角面S89和第三对角面S10之间的相交线L3为所述六面体结构的中心线,相交线L3的两个顶点为Q1、Q2,相交线L3的长度等于所述六面体结构的棱长,本实施方式中,此六面体结构为立方体,其所有的棱长均相等。
图14为图13所示的合光单元的立体分解图。结合参阅图13和图14,本实施方式为在图6所示的实施方式的基础上,再沿第三对角面S10切割,使得第一棱镜单元221被分割为第一子棱镜2211和第二子 棱镜2212,使得第二棱镜单元222被分割为第三子棱镜2221和第四子棱镜2222,使得第三棱镜单元223被分割为第五子棱镜2231和第六子棱镜2232,使得第四棱镜单元224被分割为第七子棱镜2241和第八子棱镜2242。如图14所示,所述第一子棱镜2211和所述第二子棱镜2212之间对接的位置为第一子面S101。第一子面S101为四边形,第一子棱镜2211和第二子棱镜2212均为五面体棱镜。所述第三子棱镜2221和所述第四子棱镜2222之间对接的位置为第二子面S102,第二子面S102呈三角形,第三子棱镜2221为五面体棱镜,第四子棱镜2222为四面体棱镜。所述第五子棱镜2231和所述第六子棱镜2232之间对接的位置为第三子面S103。第三子面S103为四边形,所述第五子棱镜2231和所述第六子棱镜2232均为五面体棱镜。所述第七子棱镜2241和所述第八子棱镜2242之间对接的位置为第四子面S104,第四子面S1042呈三角形,所述第七子棱镜2241为五面体棱镜,所述第八子棱镜2242为四面体棱镜。所述第一子面S101、所述第二子面S102、所述第三子面S103和所述第四子面S104构成所述六面体结构的第三对角面S10。
图15所示为图13所示的合光单元22的一种状态的立体分解示意图,图15所示的状态为在图14所示的状态的基础上,将第一棱镜单元221、第二棱镜单元222、第三棱镜单元223和第四棱镜单元224均作为一个整体显示,即第一子棱镜2211和第二子棱镜2212对接、第三子棱镜2221和第四子棱镜2222对接、第五子棱镜2231和第六子棱镜2232对接、及第七子棱镜2241和第八子棱镜2242对接。对比图15和图7,可以发现,图15所示合光单元中的第一棱镜单元221的整体外形、第二棱镜单元222的整体外形、第三棱镜单元223的整体外形和第四棱镜单元224的整体外形均与图7中对应的特征是相同的结构形态。
一种实施方式中,图13所示的合光单元22包括三个分光膜,分别为第一分光膜225、第二分光膜226和第三分光膜227。参阅图16、图17和图18,这三个图分别表示了三个分光膜所在的位置,为了清楚地表达分光膜和合光单元棱镜之间的关系,图16、图17和图18分别将第一分光膜225、第二分光膜226和第三分光膜227从合光单元22中分离出来单独显示,这三个分光膜均为长方形结构,通过长方形的四个顶点的标号可以判断它们所在的合光单元中的具体的位置。具体而言,如图16所示,第一分光膜225位于第一对角面S67处,第一分光膜225的面积可以与第一对角面S67的面积相等(如图16所示)。其它实施方式中,第一分光膜225的面积可以小于第一对角面S67的面积,可以理解的是,第一分光膜225的形状也可以不同于第一对角面S67的形状。如图17所示,第二分光膜226位于第二对角面S89处,第二分光膜226的面积可以与第二对角面S89的面积相等。如图18所示,第三分光膜227位于第三对角面S10处,第三分光膜227的面积可以与第三对角面S10的面积相等。
所述第三分光膜227、所述第一分光膜225和所述第二分光膜226分别用于反射不同波长范围的光线。一种实施方式中,第一分光膜225用于反射第三波长范围的光,且透射第一波长范围的光和第二波长范围的光。例如,所述第一分光膜225为反绿透红蓝膜层。第二分光膜226为反射第二波长范围的光,且透射第一波长范围的光和第三波长范围的光,例如,所述第二分光膜226为反蓝透红绿膜层。第三分光膜227为反射第一波长范围的光且透射第二波长范围的光及第三波长范围的光,例如,所述第三分光膜227为反红透蓝绿膜层。
一种实施方式中,所述第二分光膜226和所述第三分光膜227均包括四个子膜,如图17和图18所示,这四个子膜中,两个呈三角形,另两个呈梯形。所述第一分光膜225为一体式的结构,且呈长方形。本方案限定了第二分光膜226和第三分光膜227的具体的结构,及第一分光膜225为一体式结构的方案,本方案设计的分光膜应用在由八块棱镜构成的合光单元中,由于第一分光膜可以为一体式结构,具有结构简洁,组装方便的优势。
图19为本申请一种实施方式提供的光机20的立体示意图,图19示意性地表达了图13所示的合光单元在光机20中与发光单元之间的具体的位置关系。如图19所示,发光单元21包括第一波长范围发射单元211、第二波长范围发射单元212、第三波长范围发射单元213、第一柔性电路板214、第二柔性电路板215和第三柔性电路板216。第一波长范围发射单元211和第二波长范围发射单元212相对设置在合光单元22的相对的两个侧面,第三波长范围发射单元213位于第一波长范围发射单元211和第二波长范围发射单元212之间。
图20为图19所示的光机的一个方向的平面图,图21为图19所示的光机中的合光单元和发光单元的分解示意图,结合图19、图20和图21,能够清楚地表达合光单元22和发光单元21之间的位置关系。所述第一波长范围发射单元211的发光面正对所述合光单元22的所述六面体结构的第一入光面S1,所述第二波长范围发射单元212的发光面正对所述合光单元22的所述六面体结构的第二入光面S2,所述第三波长范围发射单元213的发光面正对所述合光单元22的所述六面体结构的第三入光面S3,所述第一入光面S1和所述第二入光面S2相互平行,所述第三入光面S3垂直于所述第一入光面S1。如图19所示,所述第 一波长范围发射单元211的发光面的法线方向A1、所述第三波长范围发射单元213的发光面的法线方向A3和所述第二波长范围发射单元213的发光面的法线方向A2均垂直于所述光机的所述光学成像单元23的光轴23P,所述第一波长范围发射单元211的发光面的法线方向A1和所述第二波长范围发射单元213的发光面的法线方向A2为相同的方向,所述第三波长范围发射单元213的发光面的法线方向A3垂直于所述第一波长范围发射单元211的发光面的法线方向A1。
图19所示的实施方式提供的光机20中的第一柔性电路板214、第二柔性电路板215、第三柔性电路板216的延伸方向均和光轴23P的方向相近或相同,结合参阅图1、图2和图3,当光机20安装在近眼显示设备内时,第二柔性电路板215可以顺着结构件100延伸,不需要折叠第二柔性电路板215,有利于整机尺寸的减小。
图19所示的实施方式提供的光机20安装至结构件的镜腿时,镜腿包括内侧面和外侧面,镜腿的内侧面为近眼显示设备在佩戴状态下贴近人脸的部分,外侧面则是近眼显示设备在佩戴状态下远离人脸的部分。一种实施方式中,本申请通过将第三波长范围发射单元213靠近镜腿的外侧面,合光单元22上的一个非入光面S5(具体为和第三入光面S3相对设置的非入光面S5,如图21所示)靠近镜腿的内侧面,这样的设置,使得近眼显示设备在靠近人脸的一侧不设置发光单元,能够降低用户感知到热的风险,提升用户使用的体验感。
一种实施方式中,图19所示的实施方式提供的光机20安装至结构件的镜腿时,光机20的出光侧为近眼显示设备的镜片上的光波导。布置光机20的各部分结构的具体位置时,可以将第二波长范围发射单元212位于合光单元22的底侧,第一波长范围发射单元211位于合光单元22的顶侧。第二波长范围发射单元212位于合光单元22的底侧,可以使得光机出瞳处的蓝光能量上弱下强,光机20的具体架构与光波导的结构搭配使用,可以使得光波导利用到较强部分的蓝光,提升光效。具体而言,第二波长范围发射单元212的摆放位置靠近光波导的中继区(即中继光栅),因此,本方案可以提升近眼显示设备的光效。
图19-图21只是示意性地描述了一种发光单元和合光单元之间的布置方案,对于图13所示的合光单元而言,由于合光单元13包括8个彼此独立的棱镜结构,而且是在图6所示的四个棱镜的基础上再沿第三对角面切割形成的,图6所示的合光单元在光机中与发光单元之间位置关系的所有的可能实现的灵活布置的方案均适用于图13所示的合光单元。即图10A、图11和图12所示的光机中的合光单元和发光单元的布置方案也适用图13所示的合光单元,只需要根据具体的布置方案去调节各分光膜的属性。
一种实施方式中,本申请提供合光单元22整体呈立方体结构,立方体结构的设计,使得发光单元中不同颜色的光源(即第一波长范围发射单元211、第二波长范围发射单元212和第三波长范围发射单元213)从入光面至出光面的光程可以保持一致,即第一波长范围发射单元所发出的红色光线、第二波长范围发射单元所发出的蓝色光线及第三波长范围发射单元所发出的绿色光线在合光单元内的传输路径的长度是一样的,光的传输路径即光程,光程相同,有利于保证光机成像的清晰度。若某一种颜色的光的光程与其它颜色光的光程不一致,会导致光机投影的图像清晰度不好,图像较模糊。
一种实施方式中,合光单元22的入光面的面积大于对应的发光单元的发光面的面积,这样可以保证发光单元发出的光线更多地进入合光单元,提升光线传输的效率。一种实施方式中,光学成像单元的入光面的面积大于所述合光单元的出光面的面积,这样可以保证合光单元出射的光线更多地进入光学成像单元,提升光线传输的效率。一种具体的实施方式中,光学成像单元可以为镜组,即由一个或多个透镜构成。混合光束射出的方向可以为光学成像单元的光轴方向。
一种实施方式中,本申请提供的合光单元可以基于呈六面体状的光学结构,先做切割,即沿对角面切割,针对图6所示的合光单元22,需要在第一对角面和第二对角面位置切割,针对图13所示的合光单元22,需要在第一对角面、第二对角面和第三对角面位置切割。切割后对各单独的棱镜结构进行处理,例如,在需要设置分光膜的位置通过化学沉积、涂覆或电镀的方式设置分光膜。然后再将各棱镜结构进行对接胶合固定为一体式结构。
方案二:光学组件(耦入光栅反射0级光线偏出光机)
图22为本申请一种实施方式提供的光学组件200的示意图。参阅图22,一种实施方式中,本申请提供的光学组件200包括光机20和光波导10A,光机20包括发光单元21、合光单元22和光学成像单元23,光波导10A位于光机20的出光侧,光波导10A包括波导基底19、耦入光栅11、中继光栅13和耦出光栅12。耦入光栅11、中继光栅13和耦出光栅12均形成在波导基底19的表面。耦入光栅11正对光机20的 出光面。光机20的发光单元21所发出的光线经过合光单元22合成的混合光束经过光学成像单元23后投射至耦入光栅11上。本实施方式中,耦光入栅11形成在波导基底19上的耦入表面11S,耦入表面11S基本上呈平面状,耦入表面11S与光机20的光轴23P接近垂直。可以理解的是,耦入表面11S可以与光机20的光轴23P垂直,或者耦入表面11S和光机20的光轴23P之间的夹角在较小范围内,例如耦入表面11S和光机20的光轴23P之间的夹角小于光机20的视场角的二分之一,即
如图22所示,发光单元21中第一位置B1所发出光线经过合光单元22和光学成像单元23后被调制为某一方向的平行光,这一光线经过耦入光栅11调制后,20%-30%的能量进入波导基底19,进入波导基底19的光线会在波导基底19中进行全反射,再通过中继光栅13,传送至耦出光栅12,且通过耦出光栅12耦出至人眼,形成虚拟图像B11(如图23所示)。光机投射至耦入光栅11的平行光的40%的能量被直接反射(虚线表示的光线),即反射0级,由于耦入光栅11所在的耦入表面11S与光轴23P垂直或二者之间的夹角在较小范围,导致被耦入光栅11反射的光线会进入光机20。进入光机20的这部分光线经过光学成像单元23和合光单元22后聚焦于发光单元21的第二位置B2。由于发光单元21的屏幕上的金属背板和玻璃盖板有较高的反射率,聚焦于第二位置B2的光线将原路返回,并被耦入光栅11调制,最终进入波导基底19,在波导基底19内进行全反射后由耦出光栅12耦出至人眼,形成鬼像B21(如图23所示)。
图23为图22所示的光学组件所产生的鬼像问题的示意图。一种实施方式中,如图23所示,根据光路可分析得到,鬼像B21和原像(虚拟图像B11)将成180°旋转对称关系。
本申请为了解决如图23所示的鬼像问题,提供一种新的光波导的结构,通过光波导的入光位置的设计,使得耦入光栅位置反射的光线偏离光机,即,耦入光栅位置反射的光线的方向会位于光机的光学有效区之外,不会返回至光机内。一种实施方式中,光波导包括波导基底和耦入光栅,所述波导基底包括斜面,所述斜面位于所述耦入光栅和所述波导基底结合的位置或者位于所述耦入光栅和所述波导基底结合位置的入光侧,所述耦入光栅用于接收所述光机的光,所述斜面朝向所述光机,所述光机具有光轴,与所述光轴垂直的方向为第一方向,所述斜面和所述第一方向之间的夹角大于等于所述光机的视场角的二分之一,以使所述耦入光栅反射的所述光机的视场角的边缘光线能够偏出所述光机,这样使得光学组件能获得较好的图像显示效率,解决了鬼像的问题。
图24A和图24B为本申请一种实施方式提供的光学组件的示意图,图24A和图24B分别显示了发光单元上的B1位置和B2位置发出的光线,经过耦入光栅反射的示意图。
一种实施方式中,如图24A和图24B所示,光学组件包括光机20和光波导10A,光波导10A包括波导基底19、耦入光栅11、中继光栅13和耦出光栅12。一种实施方式中,耦入光栅11、中继光栅13和耦出光栅12形成在波导基底19的表面。一种实施方式中,波导基底19为高折波导衬底材料,波导基底19的折射率可以大于等于1.6。一种实施方式中,波导基底19的材料为TiO2、氮化硅、氮化镓、高折树脂材料等等。光信号在波导基底19内能够产生全反射传输。
波导基底19整体呈平板状架构,波导基底19的外表面大部分面积为主平面190,主平面190呈平面状,且主平面190与光机20的光轴23P垂直或二者之间的夹角在较小范围,可以理解为,允许制作工艺的误差或组装公差等因素形成的主平面190与光轴23P之间形成较小的夹角。中继光栅13和耦出光栅12形成在主平面190上。如图24A和图24B所示,波导基底19面向光机20的一侧、且垂直于光轴23P的表面和背离光机20的一侧、且垂直于光轴23P的表面均为主平面190。波导基底19包括斜面191,斜面191位于所述耦入光栅11和所述波导基底19结合的位置。本实施方式中,所述波导基底19为一体成型结构,所述斜面191为通过在所述波导基底19上去除部分材料形成的结构。一种实施方式中,斜面191形成在波导基底19上面对光机20的表面。本方案限定一种具体的斜面形成方式,通过对波导基底去除部分材料形成斜面,易于保证斜面位置处的折射率的稳定性,即在斜面形成过程中,不容易改变波导基底的折射率,从而能够保证耦入光栅的衍射效率,保证耦入光线不会产生不需要的偏折,保证形成的虚拟图像的真实性,不产生扭曲。
一种实施方式中,斜面191的制作过程如下:先提供一个平板状的波导基底,此波导基底的两个表面均为平面状,在其中一个平面的靠近边缘的位置通过切割的方式去掉一部分材料,形成斜面,再对斜面进行表面处理,例如抛光。
一种实施方式中,如图24A所示,波导基底19的两个主平面190分别为第一主平面和第二主平面,第一主平面和第二主平面相对设置,第一主平面和第二主平面均可以垂直于光机20的光轴23P。斜面191的一端连接波导基底19的第一主平面,斜面191的另一端连接波导基底19的第二主平面,本实施方式中,斜面191与远离光机20的主平面190之间构成尖角结构。其它实施方式中,斜面191和远离光机20的主 平面190之间也可以通过侧平面或弧形表面连接。
为了方便描述,图24A中,在光机20的下方位置示意性地绘出入射边缘光线、光轴23P、反射光线之间的位置关系及角度标号。图24A所示的实施方式中,耦入光栅11形成在所述斜面191上。一种实施方式中,耦入光栅11为衍射光栅,例如:利用光刻技术制造的表面浮雕光栅(Surface Relief Grating)、或基于全息干涉技术制造的全息体光栅(Volumetric Holographic Grating)。耦入光栅11用于接受光机20传输的混合光束,并对混合光束进行调制,在耦入光栅11位置,部分光束通过耦入光栅进入波导基底19,部分光束被耦入光栅反射。
图24A中示意性地表达光机20的FOV边缘光线,即发光单元21的B1位置入射至耦入光栅11上的光线,及此光线经过耦入光栅11反射后形成反射光线的示意图。具体而言,光机20的发光单元21的第一位置B1发出的光线,经过合光单元22后进入光学成像单元23,经过光学成像单元23调制后,形成光机20的视场角的入射边缘光线,且投射至耦入光栅11上。耦入光栅11对入射光进行调制,20%-30%的能量进入波导基底19,进入波导基底19的光线会在波导基底19中进行全反射,再通过中继光栅13,传送至耦出光栅12,且通过耦出光栅12耦出至人眼,形成虚拟图像。光机20投射至耦入光栅11的平行光的40%的能量被直接反射(虚线表示的光线),即反射0级。入射在所述耦入光栅11上的所述光机20的视场角的入射边缘光线与所述光轴23P之间的夹角为第一角度β1,经所述耦入光栅11的反射光线(称为耦入光栅反射光线)与所述光轴23P之间的夹角为第二角度β2,所述第二角度β2大于所述第一角度β1。由于第二角度β2大于所述第一角度β1,可以保证反射光线不进入光机20。
一种实施方式中,β2>β1+0.1°。光波导在制作过程中,或在将光导波组装至近眼显示设备中的过程中,制作的公差或组装的误差,很容易导致耦入光栅反射光线与光轴之间的夹角和边缘入射光线和光轴之间夹角的角度误差,为了补偿此误差,本申请一种实施方式通过限定第二角度β2和第一角度β1之间至少具有0.1°的差值,能够提升制作良率。
本方案通过斜面191和耦入光栅11的设置,使得耦入光栅11的设置的角度与波导基底19的主平面190之间形成倾斜状态,这样,入射在耦入光栅11上的部分光线反射,就形成了与光轴23P之间形成夹角为第二角度β2的耦入光栅反射光线。耦入光栅反射光线和光轴23P之间的夹角第二角度β2大于入射在所述耦入光栅11上的所述光机20的视场角的入射边缘光线与所述光轴23P之间的夹角(第一角度β1),这样,可以保证耦入光栅11反射的光线偏出光机20,“偏出光机20”可以理解为耦入光栅反射光线不会进入光机20的光学有效区,耦入光栅反射光线位于光机20的光学有效区之外,就不会反射回光机20的发光单元21上。因此,本实施方式提供的光学组件不存在耦出光栅11的反射光线进入光机20后再一次反射形成鬼像的现象。
本实施方式通过限定发光单元21的第一位置B1发出的光线,即入射边缘光线,经过耦入光栅11的反射光线偏离光机,由于此入射边缘光线为光机FOV的极限位置的光线,结合耦入光栅11是设置在斜面191上的,斜面191和光轴23P之间并非垂直关系,而是形成一定的角度,这样的设计,可以保证发光单元21上其它位置发出的光线均是偏出光机的。
参阅图24B,图24B中示意性地表达了发光单元21上的第二位置B2处发射的光线经过耦入光栅11后的反射路径。如图24B所示,发光单元21上的第二位置B2处发出的光线经过合光单元22后进入光学成像单元23,经过光学成像单元23调制后,投射在耦入光栅11上,在耦入光栅11的位置进行反射,且反射光线与光轴23P之间的夹角为第三角度β3。第三角度β3大于第二角度β2,因此,第二位置B2处发射的光线经过耦入光栅11反射后的光线会偏离光机20。
图25A和图25B为本申请一种实施方式提供的光学组件的示意图,图25A和图25B分别显示了发光单元上的B1位置和B2位置发出的光线,经过耦入光栅反射的示意图。
图25A所示的实施方式与图24A所示的实施方式的区别在于:耦入光栅11的设置位置不同。如图25A所示,一种实施方式中,所述波导基底19包括主平面190,所述斜面191相对所述主平面190倾斜,所述耦入光栅11形成在所述主平面190上,在所述光轴23P的延伸方向上,所述斜面191位于所述耦入光栅11和所述光机20之间,所述光机20的视场角的入射边缘光线经过所述斜面191进入光波导10A,并入射在所述耦入光栅11上。入射边缘光线投射在斜面191上时,会发生反射,形成图25A所示的斜面反射光线,此斜面反射光线的能量较弱,例如不足入射至耦入光栅位置的能量的10%,斜面反射光线即使进入光机亦不影响成像效果,无法产生鬼像,因此,本申请暂不考虑斜面反射光线是否会进入光机。
图25A所示的入射边缘光线在斜面191位置进入光波导10A,并投射耦入光栅11上,在耦入光栅11位置会形成反射0级,即耦入光栅反射光线。本申请的设计能够使耦入光栅反射光线偏出光机20。具体而 言,耦入光栅11会反射部分光线,反射的部分光线直接射出光波导10A,构成耦入光栅反射光线。由于斜面191的相对耦入光栅11所在的主平面190倾斜设置,从斜面191进入光波导10A后投射在耦入光栅11上的光线,在斜面191位置发生折射,这样可以保证在耦入光栅11位置反射的耦入光栅反射光线会偏出光机20,“偏出光机20”可以理解为反射光线不会进入光机的光学有效区,反射光线位于光机的光线有效区之外,就不会反射回光机的发光单元上。因此,本实施方式提供的光学组件不存在耦出光栅11的反射光线进入光机20后再一次反射形成鬼像的现象。
图25A所示的实施方式,经所述耦入光栅11反射的所述光机20的视场角的边缘光线经过所述斜面191进入光波导内部时,发生光线的折射,使得光线投射在耦入光线上后,能够形成偏出光机的耦入光栅反射光线。具体而言,投射在斜面191上和光机20的视场角的入射边缘光线和光机20的光轴23P之间的夹角为第一角度β1,在耦入光栅11处反射的耦入光栅反射光线和光机20的光轴23P之间的夹角为第二角度β2,所述第二角度β2大于所述第二角度β1。一种实施方式中,β2>β1+0.1°。
图25A所示的实施方式通过限定所述第二角度β2大于所述第一角度β1,使得发光单元21的第一位置B1发出的光线,即入射边缘光线,经过耦入光栅11的反射光线偏离光机,由于此入射边缘光线为光机FOV的极限位置的光线,结合耦入光栅11是设置在斜面191的背离光机的一侧,斜面191和光轴23P之间并非垂直关系,而是形成一定的角度,对入射边缘光线进行折射。这样的设计,可以保证发光单元21上其它位置发出的光线经过耦入光栅11的反射后均是偏出光机的。
参阅图25B,图25B中示意性地表达了发光单元21上的第二位置B2处发射的光线经过耦入光栅11后的反射路径。如图25B所示,发光单元21上的第二位置B2处发出的光线经过合光单元22后进入光学成像单元23,经过光学成像单元23调制后,投射在斜面191上,经过斜面191的折射后进入光波导10A,并投射在耦入光栅11上,在耦入光栅11的位置进行反射,且反射光线与光轴23P之间的夹角为第三角度β3。第三角度β3大于第二角度β2,因此,第二位置B2处发射的光线经过耦入光栅11反射后的光线会偏离光机20。
图25A和图25B所示的实施方式中,由于耦入光栅11形成在主平面190上,由于主平面190为波导基底19的整体的平面状的外表面,对于耦入光栅11的制作工艺,具有易于制作,对于设计及工艺步骤均具有优势。而图24A和图24B所示的实施方式,将耦入光栅11制作在斜面191上,虽然制作工艺方面有所挑战,但是耦入光栅11和光机20之间的光路比图25A和图25B所示的实施方式简洁,易于控制光传输效率。
图26A和图26B为本申请一种实施方式提供的光学组件的示意图,图26A和图26B分别显示了发光单元上的B1位置和B2位置发出的光线,经过耦入光栅反射的示意图。
如图26A所示,本实施方式中,光学组件包括光机20和光波导10A,光波导10A包括波导基底19、耦入光栅11、中继光栅13和耦出光栅12。所述波导基底19包括波导主体结构192和附加结构193,所述附加结构193固定至所述波导主体结构192的面对所述光机20的表面,斜面191形成在所述附加结构192上,所述斜面191位于所述附加结构193背离所述波导主体结构192的表面。一种实施方式中,波导主体结构192为平板状结构,如图26A所示,波导主体结构192的截面呈矩形。本方案通过在波导基底上增加附加结构193,通过附加结构形成斜面,本方案具有保护波导基底结构完整性的优势,波导基底的结构完整性有利于保证波导基底的寿命,未经切除部分结构的波导基底,强度和稳定性更好,结构稳定性好的光波导,光传输效率就相对稳定。
附加结构193可以为三角体状结构,如图26A所示,附加结构193的截面呈三角形。一种实施方式中,波导主体结构192的材料和附加结构193的材料相同。一种实施方式中,波导主体结构192的折射率和附加结构193的折射率相同。例如,波导主体结构192的材料和附加结构193的材料均为高折衬底材料,高折衬底材料可以为但不限于:TiO2、氮化硅、氮化镓、高折树脂材料等等。波导主体结构192的材料和附加结构193的材料相同的设计,可以保证入射至波导基底19的光线在附加结构193和波导主体结构192中的传输具有一致性,避免因折射率不同导致光线偏折影响衍射效率或无法得到需要的入射光的角度,因此,本申请通过限定附加结构193的折射率和材质与波导基底19一致,能够保证光波导10A的光学性能。本申请所定义的折射率相同,其中的“相同”,可以理解为完全相同,可存在较小的公差,也可以理解为近似相同,只要使得入射光的角度在设计需求范围内即可。
一种实施方式中,波导主体结构192和附加结构193之间可以通过光学胶水粘合。所述光学胶水具有高折射率,例如所述光学胶水的折射率和所述波导主体结构及所述附加结构的折射率相同。导波主体结构192和附加结构193结合的表面处可以进行抛光处理后再进行粘接固定。本实施方式中,附加结构193上 的斜面191的位置需要抛光处理,以提升光的透过率。
一种实施方式中,波导主体结构192和附加结构193之间也可以通过分子间键合方式结合为一体,分子键合的方式避免引入胶水等其他介质,可以更好的保证波导主体结构192和附加结构193的折射率匹配。
图26A所示的实施方式中,所述耦入光栅11形成在所述斜面191上,从所述耦入光栅11入射的光线经过所述附加结构193后进入所述波导主体结构192,经所述耦入光栅11的反射光线(即耦入光栅反射光线)与所述光轴23P之间的夹角为第二角度β2,入射在所述耦入光栅11上的所述光机20的视场角的入射边缘光线与所述光轴23P之间的夹角为第一角度β1,所述第二角度β2大于所述第一角度β1。一种实施方式中,β2>β1+0.1°。本方案限定了设置附加结构与波导基底结合的方案中,耦入光栅的具体的位置的一种方案,本方案将耦入光栅设置在斜面上。使得耦入光栅的入射光的光路简洁,入射光的能量易于控制,有利于提升光效。
图26A所示的实施方式的工作原理与图24A所示的实施方式的工作原理相同。图26A所示的实施方式通过限定发光单元21的第一位置B1发出的光线,即入射边缘光线,经过耦入光栅11的反射光线偏离光机,由于此入射边缘光线为光机FOV的极限位置的光线,结合耦入光栅11是设置在斜面191上的,斜面191和光轴23P之间并非垂直关系,而是形成一定的角度,这样的设计,可以保证发光单元21上其它位置发出的光线均是偏出光机的。
参阅图26B,图26B中示意性地表达了发光单元21上的第二位置B2处发射的光线经过耦入光栅11后的反射路径。如图26B所示,发光单元21上的第二位置B2处发出的光线经过合光单元22后进入光学成像单元23,经过光学成像单元23调制后,投射在耦入光栅11上,在耦入光栅11的位置进行反射,且反射光线与光轴23P之间的夹角为第三角度β3。第三角度β3大于第二角度β2,因此,第二位置B2处发射的光线经过耦入光栅11反射后的光线(即耦入光栅反射光线)会偏离光机20。
图27A和图27B为本申请一种实施方式提供的光学组件的示意图,图27A和图27B分别显示了发光单元上的B1位置和B2位置发出的光线,经过耦入光栅反射的示意图。
如图27A所示,本实施方式与图26A所示的实施方式的区别在于:耦入光栅11的设置位置不同。如图27A所示,一种实施方式中,所述波导主体结构192包括主平面190,附加结构193上的所述斜面191相对所述主平面190倾斜,所述耦入光栅11形成在所述主平面190上,在所述光轴23P的延伸方向上,所述斜面191位于所述耦入光栅11和所述光机20之间。所述光机20的视场角的边缘光线经过所述斜面191进入所述附加结构193和所述波主导体结构192且入射在所述耦入光栅11上,经所述耦入光栅11反射的所述光机20的视场角的边缘光线为反射0级,即耦入光栅反射光线。耦入光栅反射光线直接射出光波导10A,且偏出所述光机20,“偏出光机20”可以理解为反射光线不会进入光机的光学有效区,耦入光栅反射光线位于光机的光线有效区之外,就不会反射回光机的发光单元上。因此,本实施方式提供的光学组件不存在耦出光栅11的反射光线进入光机20后再一次反射形成鬼像的现象。
本实施方式中,经所述耦入光栅11反射的耦入光栅反射光线与所述光轴23P之间的夹角为第二角度β2,所述光机20的视场角的边缘光线入射在所述斜面191上的入射边缘光线和所述光轴23P之间的夹角为第一角度β1,所述第二角度β2大于所述第一角度β1。一种实施方式中,β2>β1+0.1°。
入射边缘光线投射至斜面191上时,在斜面191的位置会发生反射,称为斜面反射光线。此斜面反射光线的能量较弱,例如不足入射至耦入光栅位置的能量的10%,斜面反射光线即使进入光机亦不影响成像效果,无法产生鬼像,因此,本申请暂不考虑斜面反射光线是否会进入光机。
图27A所示的实施方式与图25A所示的实施方式的原理相似。通过限定所述第二角度β2大于所述第一角度β1,使得发光单元21的第一位置B1发出的光线,即入射边缘光线,经过耦入光栅11的反射光线偏离光机,由于此入射边缘光线为光机FOV的极限位置的光线,结合耦入光栅11是设置在斜面191的背离光机的一侧,斜面191和光轴23P之间并非垂直关系,而是形成一定的角度,对入射边缘光线进行折射。这样的设计,可以保证发光单元21上其它位置发出的光线经过耦入光栅11的反射后均是偏出光机的。
参阅图27B,图27B中示意性地表达了发光单元21上的第二位置B2处发射的光线经过耦入光栅11后的反射路径。如图27B所示,发光单元21上的第二位置B2处发出的光线经过合光单元22后进入光学成像单元23,经过光学成像单元23调制后,投射在斜面191上,经过斜面191的折射后进入光波导10A,并投射在耦入光栅11上,在耦入光栅11的位置进行反射,且反射光线与光轴23P之间的夹角为第三角度β3。第三角度β3大于第二角度β2,因此,第二位置B2处发射的光线经过耦入光栅11反射后的光线会偏离光机20。
对于图26A和图27A所示的实施方式,附加结构193和波导主体结构192之间的位置关系可以具有 多种不同的形态。如图28所示,图28示意性地描述了三种附加结构193和波导主体结构192之间的位置关系,可以理解为,附加结构93上的斜面191相对波导主体结构192倾斜的方向可调,斜面191倾斜的方向不同,可以对应不同的光机的视场角的定义,例如,光机的视场角可以为水平面视场角、垂直面视场角。
与光机20的光轴23P的延伸方向相垂直的方向为参考方向,因此,本申请提供的光学组件中,波导基底上的斜面和此参考方向之间的夹角大于等于所述光机的:水平面视场角的二分之一或垂直面视场角的二分之一。一种实施方式中,所述光机的光轴为所述光机的有效光学区的中心轴,可以理解为,光机可以为非离轴光学系统,光学有效区的中心轴为光轴,为光机的设计提供了便利性。其它实施方式中,光机也可以为离轴光学系统。
图29示意性地描述了光机视场角的参数。一种具体的实施方式中,光机的视场角(FOV)定义和计算规则如下,如图29所示,对角线为AB的方形区域为整个图像显示区域,O点的位置为人眼的位置,那么人眼观察到的方形区域对应的FOV大小即为2*tan(AC/S)。
举例说明,在图25A和图27A所示的实施方式的基础上,比如显示画面FOV为30度,比例为4:3,那么水平方向FOV和垂直方向FOV分别为24度和18度。一种实施方式中,垂直于光轴23P的方向为参考方向,所述斜面191和参考方向之间的夹角大于等于12度。
结合参阅图25A、图27A和图29,一种实施方式中,光机边缘FOV对应图29中的点E。假设此时水平方向FOV的一半为β1,所述斜面191和所述参考方向之间的夹角大于等于β2,波导基底19周围介质折射率为n1,波导基底19折射率为n2,那么根据折射定律将存在公式:
n1sin(β1+β2)=n2sin(β2),
可以得到
那么斜面191和所述参考方向之间的夹角大于等于这个值即可。
假设n1为1,n2为1.9,那么计算可得:斜面191和参考方向之间的夹角大于等于12.7°。
方案三:包括一维光栅和二维光栅的耦出光栅架构
一种实施方式中,本申请提供一种光波导,光波导可为衍射光波导,衍射光波导具有轻薄、紧凑、高亮度等优势,此类型的光波导应用在近眼显示设备中,能够促进近眼显示设备轻量化及易于穿戴两方面优势。对于光波导而言,在其设计过程中,如何提升光传输的效率、保证图像光的均匀性以及降低加工制作难度为业界研发的方向。
图30为本申请一种实施方式提供的光波导的示意图。参阅图30,一种实施方式中,光波导10A包括波导基底19和形成在波导基底19上的耦入光栅11和耦出光栅12,耦入光栅11用于和光机相对设置,用于接收光机传送的光束,并将光束耦入波导基底19内,光束在波导基底19中进行全反射传播,通过耦出光栅12耦出,使人眼看到图像。一种实施方式中,耦出光栅12主要有两个作用:一是扩瞳,让光线可以覆盖更大的面积;二是耦出光线,使光线进入人眼。
一种实施方式中,耦出光栅12为二维光栅结构,本方案中,耦出光栅12具有两个周期方向,光线在耦出光栅12中的传播过程中,一束光能够被耦出光栅12分为8个传播方向(如图31所示,图31为二维光栅将光分为8个传播方向的示意图)。可以理解的是,8个传播方向的光不会都被耦出,某些方向的光线因无法耦出而浪费。图32为图31所示的光波导的耦出光效率图。如图32所示为耦出光线的效率图,其中颜色较深的区域为耦出效率高的区域,颜色较浅的区域为耦出效率较低的区域,从图32所示的耦出光效率图,可以看出,方形区域中左侧中间区域的耦出效率最高,方形中间区域从左至右耦出光效率渐渐变弱,方形四个角落位置耦出光效率最低。
图30所示的光波导10A中的耦出光栅12由于全部区域均为二维光栅架构,导致一束光经过耦出光栅将产生8个传播方向,很多光线并不会进入人眼被直接浪费掉,造成能量浪费。而且不同FOV的光线进入人眼前被二维光栅调制的次数不同,造成进入人眼的能量不同,即人眼看到的图像的光均匀性不一致。
为了解决能量浪费及光线不均匀的问题,本申请一种实施方式提供一种耦出光栅结构,所述耦出光栅包括第一区域和第二区域,所述第一区域包括第一子区域和第二子区域,所述第一子区域和所述第二子区域内的光栅类型均为一维光栅,所述第二区域内的光栅类型为二维光栅,所述第二区域的中心和所述耦入光栅的中心之间的连线称为中轴线,所述第一子区域和所述第二子区域分布在所述中轴线的两侧。本申请 通过第一区域中的一维光栅使得光线大部分能量均被传送至第二区域,能够提升光传播的效率,提升光的均匀性,而且可以降低加工制作的难度,降低成本。具体描述如下。
一种实施方式中,参阅图33,光波导10A的波导基底19可以为具有较高折射率的晶圆或压印胶。耦入光栅11和耦出光栅12形成在波导基底19的表面。耦入光栅11位于光波导10A的入光区域,耦入光栅12位于光波导10A的出光区域。本实施方式中,耦出光栅12包括第一区域121和第二区域122。耦入光栅11和耦出光栅12沿第一方向X排列。在第一方向上,第一区域121位于第二区域122的入光侧,第一区域121位于耦入光栅11和第二区域122之间。所述第一区域121包括第一子区域1211和第二子区域1212,所述第一子区域1211和所述第二子区域1212沿第二方向Y排列,第一子区域1211的中心和第二子区域1212的中心之间的连线方向为所述第二方向Y,所述第二方向Y和所述第一方向X相交,具体实施方式中,第一方向X和第二方向Y之间相互垂直或接近垂直。所述第一子区域1211和所述第二子区域1212内的光栅类型均为一维光栅,所述第二区域122内的光栅类型为二维光栅。图33中在第一子区域1211和第二子区域1212内示意性地用相互平行的线构成的图案表示一维光栅,第第二区域122中用网格图案表示二维光栅。图33只是示意性地表示一维光栅和二维光栅,并不是对一维光栅和二维光栅的具体结构、具体位置分布、具体的尺寸面积等参数的限定。耦入光栅11的中心和所述第二区域122的中心之间的连线称为中轴线12L,图33所示的实施方式中,中轴线12L的延伸方向为第一方向X。所述第一子区域1211和所述第二子区域1212分布在所述中轴线12L的两侧,具体而言,第一子区域1211位于中轴线12L的一侧,第二子区域1212位于中轴线12L的另一侧。本实施方式中,中轴线12L亦为耦出光栅12的中轴线,耦出光栅12可以为以此中轴线12L为对称中心的对称分布架构。所述第一子区域1211和所述第二子区域1212以所述中轴线12L为中心呈镜相对称分布。本方案通过约束所述第一子区域和所述第二子区域与中轴线之间的关系,通过镜相对称的设计,使得耦出光栅的第二区域的光的能量更均衡。
图34以一束光线为例表示耦出光栅12通过第一区域的一维光栅能够提升光传播的效率,提升光的均匀性的示意图。参阅图34,从耦入光栅11进入光波导的第一光束01传送至耦出光栅12的第一区域121时,由于第一区域121中的光栅类型为一维光栅,在第一区域121中,第一光束01被分两部分(即第一部分光束02和第二部分光束03),第一部分光束02向下传播并进入第二区域122,第二部分光束03继续向前传播并进入第二区域122,进入第二区域122的第二部分光束03在第二区域122内的二维光栅的作用下也会向下传播,形成覆盖第二区域122和第三部分光束04。第一区域121设置为一维光栅,第一区域121具有扩瞳,也可以约束光线传播方向,提高能量利用率,经过第一区域121调制的光线只有两个方向,而且这两个方向的光线均能够进入第二区域122。本申请提供的耦出光栅12可以使更大面积的光线进入人眼,或者说人眼可以在更大的面积上观察到图像。
图30所示的实施方式中,光束在耦出光栅,由于耦出光栅均是二维光栅,光束会被分成8个方向的光,而且这8个方向的光大部分都无法被耦出,形成浪费。明显可见,图33所示的实施方式提供的光波导10A中,第一光束01传播至第一区域121位置时,由于第一区域121中的光栅类型为一维光栅,第一光束01分为两个方向的光,即第一部分光束02和第二部分光束03,这两个方向的光最终均进入第二区域122。因此,图33所示的实施方式能够提升光传播的效率。
一种实施方式中,参阅图33,图33中带箭头的虚线表示第一栅线方向F1和第二栅线方向F2,所述第一子区域1211内的一维光栅的栅线延伸方向为第一栅线方向F1,所述第二子区域1212内的一维光栅的栅线延伸方向为第二栅线方向F2。所述第二区域122内的二维光栅包括相交设置的第一栅线1221和第二栅线1222。所述第一栅线1221的延伸方向为所述第一栅线方向F1,所述第二栅线1222的延伸方向为第二栅线方向F2;或者,所述第一栅线1221的延伸方向与第一栅线方向F1大致相同,所述第二栅线1222的延伸方向和第二栅线方向F2大致相同。大致相同可以理解为,所述第一栅线1221的延伸方向与第一栅线方向F1之间可以在允许的较小的夹角范围内,当夹角为0时,二者为同向或平行的关系。本申请通过第一栅线1221的延伸方向与第一栅线方向F1大致相同,所述第二栅线1222的延伸方向和第二栅线方向F2大致相同的设置,使得光波导传送的图像信息具有真实性,不会产生图像的扭曲,保证图像显示效果。
一种实施方式中,所述第一栅线方向F1和所述第二栅线方向F2之间的夹角为60度。本方案通过第一栅线方向F1和第二栅线方向F2之间的夹角为60度,能约束光线的传播方向,使得光线的传播方向匹配第二区域122中二维光栅的栅线方向,这样能够保证光线更多地被耦出,能够得到较高的光效。
一种实施方式中,所述第一子区域1211内的一维光栅的分布周期与所述第一栅线1221的分布周期相同,所述第二子区域1212内的一维光栅的分布周期与所述第二栅线1222的分布周期相同。例如,所述第一子区域1211和第二子区域1212内的一维光栅的分布周期均可以为300nm。本方案通过约束第一子区域 中的一维光栅的周期和第二区域中的第一栅线的周期相同,以及约束第二子区域中的一维光栅的周期和第二区域中的第二栅线的周期相同,可以保证耦出图像不失真,图像不会产生扭曲等不良现象,能够保证图像的显示效果。
结合参阅图33和图35,一种实施方式中,如果第二区域122中的二维光栅的栅线方向和周期发生改变,第一区域121的第一子区域1211和第二子区域1212中的一维光栅的栅线方向和周期也需要发生相应的改变。
图33所示的实施方式中,第一子区域1211和第二子区域1212之间接触,也可以理解为,第一子区域1211和第二子区域1212之间无任何间隙,或第一子区域1211和第二子区域1212之间无其它不属于第一区域的结构特征。第一子区域1211和第二区域122之间,以及第二子区域1212和第二区域122之间均为接触状态,也可以理解为,第一子区域1211和第二区域122之间,以及第二子区域1212和第二区域122之间无任何间隙,或无其它不属于耦出光栅12的结构。图33所示的实施方式中,第一子区域1211和第二子区域1212的面积相等,其它实施方式中,第一子区域1211和第二子区域1212的面积也可以不相等,可以根据具体的需求调节第一子区域1211和第二子区域1212的具体的尺寸和形态。图33所示的实施方式中,在第二方向上,第一区域121和第二区域122具有相同的尺寸,在第一方向上,第二区域122的尺寸大于第一区域121的尺寸。也可以理解为,第二区域122的面积大于第一区域121的面积。
参阅图36,一种实施方式中,第一区域121和第二区域122也可以不接触,即第一区域121和第二区域122之间具有间隔区域,而此间隔区域内无光栅结构。具体而言,第一子区域1211和第二区域122之间形成第一间隔区域1213,所述第一间隔区域1213内无光栅结构。第二子区域1212和所述第二区域122之间形成第二间隔区域1214,所述第二间隔区域1214内亦无光栅结构。一种实施方式中,所述第一间隔区域1213和所述第二间隔区域1214之间相连通。第一间隔区域1213和第二间隔区域1214的设置,有利于保证在制作耦出光栅12的过程中,提升制作良率及效率。由于第一区域121内均是一维光栅,而第二区域122中和第一区域邻近的部分为二维光栅,若第一区域121和第二区域122接触,不设置间隔区域,在制作的过程中需要精确控制各部分的边界,避免第一区域121的边缘和第二区域122的边缘重合。因此,本方案通过第一间隔区域1213和第二间隔区域1214的设置能够节约制作成本。
一种具体的实施方式中,第一间隔区域1213在第一方向X上的延伸的尺寸小于等于4mm。第二间隔区域1214在第一方向X上的延伸的尺寸小于等于4mm。本方案限定第一间隔区域和第二间隔区域沿第一方向的尺寸,有利于保证光线的利用率,及耦出光线的强度。
参阅图37,所述第一子区域1211和所述第二子区域1212之间形成第三间隔区域1215,第三间隔区域1215内无光栅结构。由于第一子区域1211和第二子区域1212中的光栅类型均为一维光栅,若第一子区域1211和第二子区域1212接触,在制作过程中,需要精确控制第一子区域1211和第二子区域1212的边界,确保二者边界不重合。若二者边界重合,在重合的部分会形成二维光栅,二维光栅会将光线分成8个不同的方向,形成光线浪费及能量的损耗。因此,本方案通过将第一子区域1211和第二子区域1212隔开,使二者边缘不接触,能够节约制作成本,保证制作良率。第三间隔区域1215在第二方向Y上延伸的尺寸为小于等于耦入光栅的最大径向尺寸。本方案通过在第一子区域和第二子区域之间设第三间隔区,有利于保证第一子区域中的一维光栅和第二子区域中的一维光栅的制作过程的简化,不需要精确控制二者邻接位置的光栅结构,只要预留第三间隔区域,就可以保证两个了区域中的一维光栅制作的更容易,节约制作和研发的成本。本方案通过约束第三间隔区域和耦入光栅最大径向尺寸的关系,使得耦入光栅传送至第三间隔区域位置的光线,仍然可以通过第一子区域和第二子区域中的一维光栅结构传送至第二区域,能够避免更多的光能的浪费。
图33所示的实施方式中,耦光光栅11和耦出光栅12的中心位置正对,耦光光栅11和耦出光栅12均以中轴线12L为中心在第二方向Y上呈对称分布。可以理解的是,不同的应用场景下,耦入光栅11和耦出光栅12的位置会做调整,当耦入光栅11相对耦出光栅12位置移动后,中轴线12L随之改变。一种实施方式中,本申请提供的光波导10A应用在近眼显示设备,即AR眼镜,在近眼显示设备中,光波导10A需要与镜片结合,也可以理解为,光波导10A需要安装在镜片上或与镜片结合为一体。在这种应用场景下,耦入光栅12通常位于靠近镜片边缘或角落位置。
参阅图38,本实施方式中,沿第一方向X,至少部分耦入光栅11正对耦出光栅12上的第一子区域1211。中轴线12L的延伸方向和第一方向X之间形成夹角。第一区域121中的第一子区域1211和第二子区域1212之间的分界线位于中轴线12L上,第一区域121中的第一子区域1211和第二子区域1212轮廓形状不同,面积也不相同。本实施方式中,第一子区域1211在第一方向X上的中心位置和第二子区域在 第一方向X上的中心位置之间的连线方向为第二方向Y。第一方向Y和中轴线12L之间形成小于90度的夹角。本实施方式,因着耦入光栅11位置的调整,使得第一区域121中的第一子区域1211和第二子区域1212具体的结构形态发生变化,但是,第一子区域1211和第二子区域1212仍然能够实现约束光束的传播方向,提升光传播效率的作用,其光学原理与图34所示的光学原理相同。
参阅图39,图39所示的一种实施方式是在基于图38所示的实施方式的其中上,在第一子区域1211和第二区域122之间设置第一间隔区域1213,在第二子区域1212和第二区域122之间设置第二间隔区域1214,在第一子区域1211和第二子区域1212之间设置第三间隔区域1215。第一子区域1211和第二子区域1212的具体的尺寸面积也做了相应的调整,第一子区域1211在第二方向Y上突出于第二区域122的顶边,第二子区域1212在第二方向Y上相对第二区域122的底边内缩。可以理解的是,其它实施方式中,耦出光栅12可以只包括第一间隔区域1213、第二间隔区域1214和第三间隔区域1215中的一个或两个。各间隔区域设置所带来的好处与图36和图37所示的实施方式相应的部分相同,不再赘述。
参阅图40,耦出光栅12中的第二区域122内包括N个二维区1222和N-1个一维区1221,N≥2。N-1个所述一维区1221分别位于相邻的两个所述二维区1222之间,其中一个所述二维区1222邻接或邻近所述第一区域121。二维区1222邻接第一区域121可以理解为:二维区1222和第一区域121接触,二者之间无间隔。二维区1222邻近第一区域121可以理解为:二维区1222和第二区域121之间不接触,二者之间具有间隔空间。所述一维区1221内的光栅类型为一维光栅,所述二维区1222内的光栅类型为二维光栅。本申请通过在第二区域122中设置二维光栅和一维光栅,且将一维光栅设置在二维光栅中间,有利于调控耦出光线的强度,使整个画面均匀性更好。具体而言,在第二区域122中,邻近第一区域121的部分光线强度大于远离第一区域121的部分的光线强度。一维区1221设置在相邻的二维区1222之间,一方面,通过一维区1221中的一维光栅能够减弱一维区1221位置的光强,另一方面,一维区1221中的一维光栅能够约束光线传播方向,使光线集中传播至一维区出光侧(图40所示的一维区的右侧)的二维区中,这样可以将二维区的光强补强,因此,整体而言,能够保证第二区域122的耦出光线的强度均匀性。
图40所示的实施方式中,第二区域122包括三个二维区1222和两个一维区1221。每一个一维区1221包括第三子区域12211和第四子区域12212,所述第三子区域12211和所述第四子区域12212沿所述第二方向Y排列且分布在所述中轴线12L的两侧。所述二维区1222中的部分光栅的栅线方向和所述第三子区域12211中的光栅的栅线方向相同,所述二维区1222中的部分光栅的栅线方向和所述第四子区域12212中的光栅的栅线方向相同。
参阅图40,一种实施方式中,中轴线12L的延伸方向为第一方向X,耦入光栅11正对耦出光栅12的中心位置。本实施方式中,第三子区域12211和第四子区域12212可以具有相同的面积,且镜像分布在中轴线12L的两侧。
参阅图41,一种实施方式中,耦出光栅11正对耦出光栅12的角落位置,中轴线12L的延伸方向相对第一方向X倾斜,中轴线12L和第一方向X之间形成夹角。本实施方式中,第三子区域12211和第四子区域12212可以具有不同的面积。
参阅图42A,一种实施方式中,本申请提供的光波导10A中的波导基底19的顶面和底面均设置耦出光栅12,耦出光栅12的具体架构可以为图33-图41任意一种实施方式所述的耦出光栅。在波导基底19的厚度方向上,位于波导基底19顶面的耦出光栅12的第一区域121和位于波导基底19底面的耦出光栅12的第一区域121正对,位于波导基底19顶面的耦出光栅12的第二区域122和位于波导基底19底面的耦出光栅12的第二区域122正对。本方案通过在波导基底19的顶面和底面均设置耦出光栅,且,耦出光栅均通过第一区域实现约束光传播方向,能更有效地提升光传播效率,提高光均匀性。
其它实施方式中,光波导10A的耦出光栅12也可以只设置在波导基底19的单面,例如,图42A所示的实施方式中,波导基底19的底面不设置耦出光栅,只有波导基底19的顶面设置耦出光栅。
其它实施方式中,参阅图42B,在波导基底19的顶面设置图33-图41任意一种实施方式所述的耦出光栅12,在波导基底19的底面设置其它类型的耦出光栅12’,其它类型的耦出光栅12’和图33-图41任意一种实施方式所述的耦出光栅12中的第二区域122正对。
方案四:稀疏孔径耦出光栅
本申请提供的近眼显示设备(例如AR眼镜)允许使用者通过一个光学融合器来同时观察周围的真实镜像及虚拟信息。具体实施方式中,近眼显示设备通过波导结构执行此功能。如图42A所示,本申请一种 实施方式提供的光波导10A包括耦入光栅11和耦出光栅12,耦入光栅11用于将光机20产生的各个视场的光线注入光波导10A,并在光波导10A传播,并由耦出光栅12将光线耦出光波导10A,以使光线进入人眼成像,产生虚拟图像信息。同时,近眼显示设备中的光波导10A允许周围景象通过光波导并进入人眼成像,从而实现使用者同时观察到真实景像及虚拟图像信息。
本申请一种具体实施方式提供的光波导10A作为AR显示方案时,存在辐辏冲突(VAC)问题,即单眼聚焦位置和双眼视差位置的冲突。辐辏冲突(VAC)现象产生的机理为:光波导一般只能产生一个虚拟的图像位置,人眼必须聚焦到该虚像处才能看到清晰的像,人眼和虚像位置之间的垂直距离为虚像距L1。同时,为了产生立体视觉,会通过双目视差来产生视差距,而视差距L2和显示的内容相关。L1≠L2时,将产生VAC问题,影响使用体验。
图43为本申请提供的光波导产生的虚像面上的虚拟图像对应的虚像距和视距差的三种不同的配置的示意图。参阅图43,在图43的a图(最左侧的图)中,虚像距L1和视差距L2相等,此时人眼感知距离和人眼聚焦距离相一致,使用者不会有不适感。在图43的b图(中间的图)中,虚拟图像所在的虚像距L1较远,人眼需要放松眼睛聚焦到远处才能看清楚虚像,但是,生成的视差距L2(由两个虚像对人眼的张角θ决定)较近,虚像张角θ较大,使用者会觉得虚拟图像在近处,此时就会产生VAC问题,使得使用者感到不适。在图43的c图(最右侧的图)中,虚拟图像所在的虚像距L1较近,人眼需要聚焦在近处才能看清虚拟图像,但是生成的视差距L2却较远,虚像张角θ较小,此时也会和使用者平时的用眼习惯相矛盾,导致VAC问题。
参阅图44,一种实施方式提供的近眼显示设备中,光机20出射光经过耦入光栅11进入光波导10A,并在光波导10A内进行全反射传播,经过中继光栅13进行转折,并通过耦出光栅12出射至人眼。光线经由耦出光栅12耦出的过程中,由于耦出光栅12为连续延伸的较大面积的光栅结构,导致耦出的光线为一个宽孔径的光束,耦出光线12耦出至人眼瞳孔处会充满整个瞳孔,耦出光线在人眼位置形成一定尺寸的眼动空间(EyeBox)EB,瞳孔和耦出光栅之间的间距为出瞳距(EyeRelief)LER,如图44所示,一种实施方式中,耦出光栅12的外轮廓呈矩形,耦出光线投射的眼动空间ER亦呈矩形,眼动空间ER的面积远大于眼睛,人眼瞳孔被耦出光线充满。
对于图44所示的光波导而言,从耦出光栅出射的光线进入人眼,在视网膜上成像,且光束会充满瞳孔。由于人眼的瞳孔尺寸在光亮环境下一般为2-4mm,因而人眼正确聚焦时,会在视网膜上成清晰的像,对于离焦的物体,经过瞳孔无法在视网膜上聚焦,而是形成弥散斑。图45为宽光束成像形成VAC现象的光路原理图,参阅图45,当人眼聚焦在深度A时,A经由人眼的瞳孔会正确聚焦在视网膜上,形成图像A’,而此时,距离人眼更近的深度B的物点,经由人眼瞳孔之后成像在视网膜的后方B’处,此时在视网膜上是成一定尺寸的弥散斑的,人眼无法对深度B的物点进行清晰成像。
本申请一种实施方式提供一种耦出光栅,耦出光栅耦出的光线为细光束阵列,可以理解为,每个光束的尺寸较小,进入瞳孔光束数量可以只有一束光,以至于光束不会充满瞳孔,一种实施方式中,光束的尺寸范围为:小于等于1.5mm。图46为细光束成像解决VAC问题的光路原理图,细光束进入人眼成像时,景深会变得很大,从而不论使用者聚焦在何处,即可使使用者观察不同视差的虚拟图像时,均能清晰的看到虚拟图像,而不用在意虚拟图像虚像距实际位于何处,从而解决光波导存在的虚像距是固定值的问题,消除VAC问题。参阅图46,当人眼聚焦到深度A时,A处物点发出的细光束经过人眼正好聚焦在视网膜上,形成清晰的物点A’。此时,距离人眼更近的深度B处的物点发出的细光束,经过瞳孔,同样不会充满瞳孔,之后经过人眼,由于离焦,会在视网膜上形成一弥散斑,但是由于细光束的孔径很小,形成的弥散斑尺寸也很小,因而人眼仍会清晰地看到B处的图像。
图47为本申请一种实施方式提供的光波导的示意图。参阅图47,本实施方式中,光波导10A包括波导基底19、耦入光栅11、中继光栅13和耦出光栅12。中继光栅13位于耦入光栅11和耦出光栅12之间,耦入光栅11接收光机投射的光线,并将光线耦入波导基底19内且在波导基底19内进行全反射传播。光线传播至中继光栅13时,通过中继光栅13的转折,使得光线投射至耦出光栅12位置。耦出光栅12将光线耦出且投射至人眼形成虚拟图像。本实施方式中,耦出光栅12包括多个子光栅125,多个子光栅125相互间隔排布。多个子光栅125呈多行多列的阵列排布,阵列排布具有相同的行间距和相同的列间距,即,任意两个邻近设置的所述子光栅125之间的间距均相等。图47所示的实施方式中,多个子光栅125构成的阵列排布架构包括60个子光栅125,排列为6行10列。每个子光栅15的外轮廓均相同,例如所有的子光栅125的外轮廓均为圆形。其它实施方式中,耦出光栅12中可以包括不同尺寸的子光栅125,或者,耦出光栅12中可包括不同形状的子光栅125,所述子光栅125的外轮廓形状可以为但不限于:圆形、三角形、 正方形或六边形。图47中所示的耦出光栅12的整体的外轮廓呈矩形,可以理解的是,其它实施方式中,可以根据具体的设计需求设计不同形状的外轮廓的耦出光栅12。
相较图44所示的实施方式,图47所示的实施方式的核心区别在于:耦出光栅12不再是一个连续的光栅整体结构,而是被分成多个子光栅125,每个子光栅125均具有耦出光线并将光线投射至人眼的功能,但每个子光栅125投射出的光线均为细光束,细光束投射至人眼时,由于其尺寸小,不能充满瞳孔,细光束的尺寸可以为0.5mm-1.5mm。
图48为图47所示的光波导的耦出光栅的示意图。参阅图48,具体而言,每个子光栅125的最大径向尺寸D小于等于1.5mm。相邻的两个所述子光栅125的间距为L,3mm≦L≦5mm,相邻的两个所述子光栅125的间距指的是相邻的两个所述子光栅125的中心之间的距离。一种实施方式中,其中一个所述子光栅125为第一子光栅1251,所述第一子光栅1251与邻近所述第一子光栅1251的其它所述子光栅125之间均设有隔开区域125G,图48中,子光栅125之外的区域(即耦出光栅12中不属于子光栅的区域均为隔开区域)均为隔开区域125G。隔开区域125G中无光栅结构,隔开区域125G无法将光束耦出。第一子光栅1251的最大径向尺寸D小于等于1.5mm。可以理解的是,一种实施方式中,所有的子光栅125均可以为同一尺寸形态的第一子光栅1251。一种实施方式中,所有的子光栅125中,其它的子光栅的尺寸和形态可以与第一子光栅1251的尺寸和形态不同,但,其它子光栅的最大径向尺寸D均小于等于1.5mm。以保证所有的子光栅125均投影细光束。
一种实施方式中,第一子光栅1251的径向尺寸为D,0.5mm≦D≦1mm。本方案限定了第一子光栅1251的径向尺寸大于等于0.5mm,可以保证第一子光栅1251能够具有耦出光栅的功能,即可以将光波导内的光线耦出至人眼,本方案限定第一子光栅1251的径向尺寸小于等于1mm,可以保证第一子光栅1251投射出的光线为细光束,即使瞳孔尺寸受环境因素影响变小的情况下,第一子光栅1251投射至瞳孔的光束仍然是细光束,不能充满瞳孔。
针对应用在室外明亮场所的环境,由于人眼瞳孔受环境的影响,会变小,因此,一种实施方式中,子光栅125中的每一个所述子光栅125的径向尺寸范围较小,具体为:0.25mm≦D≦0.75mm。
针对应用在室内较阴暗的环境,由于人眼瞳孔受环境的影响,会变大,因此,一种实施方式中,子光栅125中的每一个所述子光栅125的径向尺寸范围较大,具体为:0.75mm≦D≦1.5mm。
一种具体实施方式中,相邻的两个所述子光栅125的间距的尺寸范围为:3.5mm≦L≦4.5mm。本实施方式所限定的相邻的两个所述子光栅125的间距的范围可以满足多种应用环境和不同的应用场景,更容易保证子光栅125所耦出的光线为细光束。
图49A和图49B为本申请一中种实施方式提供的两个子光栅125的具体的结构形态。参阅图49A,一种实施方式中,子光栅125内为二维光栅架构,各所述子光栅125包括按预设周期排布的光栅微结构1252,预设周期可以为200-500nm。光栅微结构1252的具体形状可以为但不限于:六边形、平行四边形、三角形、梯形等。在子光栅125内,因光栅微结构1252的设置,使得子光栅125能够将光波导内的光线耦出,并投射至人眼。两个子光栅125之间的区域为隔开区域125G,隔开区域125G中无光栅结构,因此,隔开区域125G位置无耦出光线,因此,本申请通过限制子光栅1252的尺寸和隔开区域125G的尺寸,就能够保证子光栅125耦出的光束为细光束,且能保证在同一时刻只有一束光进入人眼瞳孔成像,结合图46所示的成像原理,可以确定,本方案可以解决VAC问题。隔开区域125G的尺寸可以理解为:相邻的两个所述子光栅125的间距和一个子光栅直径的差值。
图49B所示的实施方式与图49A所示的实施方式的区别在于:子光栅125中的光栅类型不同。图49B所示的实施方式中,子光栅125内为一维光栅架构,类似地,子光栅125中具有周期排布的光栅微结构1252。
图50为本申请一种实施方式提供的光波导的示意图。图50所示的实施方式和图47所示的实施方式的区别在于耦出结构12中的子光栅125的排布方式不同。本实施方式中,多个子光栅125排列为多行,各行所述子光栅125的排列方向为第一方向X,多行所述子光栅125中的奇数行和偶数行在错位设置,第二方向Y垂直于第一方向X,在第二方向Y上,所述奇数行的所述子光栅125正对所述偶数行的相邻的两个所述子光栅125之间的所述隔开区域125G。如图50所示,耦出光栅12中的子光栅15排列为7行,第1、3、5、7行为奇数行,第2、4、6行为偶数行,在第二方向Y上,奇数行的子光栅125正对偶数行的相邻的两个子光栅125之间的隔开区域125G。奇数行的任意一个子光栅125与偶数行的相邻的两个子光栅125构成等边三角形。在子光栅125的阵列架构中,子光栅125排列呈多个正六边形架构,本方案也称为蜂窝状的阵列排布方案。与图47所示的实施方式提供的子光栅125的正交阵列排布方案相比,本实施方式提供的蜂窝状的阵列排布方案具有的好处为:本方案能保证眼动空间位置处各细光束的相对距离为 恒定值,而正交阵列排布方案中各细光束间距在斜边方向略大于水平及竖直方向。对于本方案而言,当人眼在眼动空间内发生移动时,如眼睛转动或眼镜发生滑动时,不同的进入人眼瞳孔的细光束会发生变化,由于蜂窝状的排布方式中的各细光栅相对距离恒定,既然人眼相对眼动空间发生位移,进入人眼的光束能量能够保证相等,因此图像的变化也会更加平坦,能够提升近眼显示设备的使用体验感。
一种实施方式中,对于耦出光栅在光波导上的具体位置而言,多个子光栅125可以共面设置,即多个子光栅设置在波导基底的同一个表面上。一种实施方式中,参阅图51、图52和图53,图51为一种实施方式提供的光波导10A,在波导基底19的正反两面均设置光栅结构,即耦入光栅11、中继光栅13、耦出光栅12均成对设置在波导基底19的正面和反面。图51同时绘制出波导基底19正反两面的光栅结构,图52只绘制出波导基底19的正面的光栅结构,图53只绘制出波导基底19的反面的光栅结构。在波导基底19的厚度方向上,位于波导基底19的正面的耦出光栅12的各子光栅125和位于波导基底19的反面的耦出光栅12的各子光栅125一一对应设置,因此,图51中所示的正反两面的子光栅125为重合的关系。
参阅图54,一种实施方式中,相邻的两个所述子光栅125中的一个位于光波导的波导基底19的正面,相邻的两个所述子光栅125中的另一个位于所述波导基底19的反面,位于所述波导基底19的正面的所述子光栅125的中心为中心一125C1,位于所述波导基底的反面的所述子光栅的中心在所述波导基底的正面的垂直投影为中心二125C2,所述相邻的两个所述子光栅125的间距L为所述中心一125C1和所述中心二125C2之间的距离。
参阅图55,一种实施方式中,耦出光栅12中的子光栅125分布在波导基底19的不同的面上,图55中,圆内标有剖面线的子光栅125位于波导基底19的正面,圆内空白(未示剖面线)的子光栅125位于波导基底19的反面。
一种实施方式中,中继光栅和/或耦出光栅可以采用分区设计或渐变设计,例如,中继光栅靠近耦入光栅的区域的光栅高度较矮,远离耦入光栅的区域的光栅高度较高;耦出光栅靠近中继光栅的区域的光栅高度较矮,远离中继光栅的区域的没高度较高。参阅图56,在波导基底19的表面设置耦入光栅11、中继光栅13和耦出光栅12,中继光栅13的顶面(远离波导基底19的表面)呈斜面延伸,中继光栅13的左侧靠近耦入光栅11,右侧靠近耦出光栅12,中继光栅左侧的光栅高度较低,右侧的光栅高度较高,从中继光栅13的左侧至右侧,中继光栅13的光栅高度可以呈渐变增长的变化趋势。耦出光栅12包括第一子光栅区域126和第二子光栅区域127,所述第一子光栅区域126距离所述中继光栅12的距离小于所述第二子光栅区域127距离所述中继光栅13的距离,所述第一子光栅区域126中的所述子光栅的高度小于所述第二子光栅区域127中的所述子光栅的高度。耦出光栅12包括第一边缘1261和第二边缘1271,所述第一边缘1261为所述耦出光栅12邻近所述中继光栅13的边缘,所述第二边缘1271为所述耦出光栅12远离所述中继光栅13的边缘,从所述第一边缘1261向所述第二边缘1271的方向,耦出光栅12中的子光栅的高度呈渐变增长趋势。本方案提供的耦出光栅分区或渐变的设计有处于调节衍射效率,提升光均匀性。
一种实施方式中,每个子光栅内的光栅微结构具有相同的高度,或者具有相同的形态。在光波导中,耦入光栅、耦出光栅和中继光栅可以具有不同的光栅形貌。
一种实施方式中,参阅图57和图58,图58为图57所示的近眼显示设备中的控制单元和耦出光栅之间控制架构的示意图。本申请提供的近眼显示设备1000包括光机20、光波导10A、控制单元181、瞳孔检测件182和光栅调节件183。光机20用于投射光线至光波导10A。光波导10A包括耦入光栅11、中继光栅13和耦出光栅12。耦入光栅11接收光机20投射的光线,并将光线耦入光波导10A,光线在光波导10A内全反射传播,中继光栅13用于转折光线,以使光线投射至耦出光栅12。本实施方式中,耦出光栅12包括多个阵列排布的子光栅125。可以理解的是,多个子光栅125的排列方式可以为但不限于多行多列的阵列排列(类似图47所示的实施方式中多个子光栅的排列方式)、蜂窝状阵列排布(类似图50所示的实施方式中多个子光栅的排列方式)。
图59所示为图57和图58所示的实施方式中的一种具体的耦出光栅12的架构。参阅图59,各所述子光栅125的最大径向尺寸D小于等于1.5mm,相邻的两个所述子光栅的间距为L’,D≦L’≦4mm,L’指的是相邻的两个所述子光栅125的中心之间的距离。本方案设置的子光栅125的阵列排列为较密集的方式,相邻的子光栅125之间的距离可以为零,也就是说,子光栅可以一个挨着一个地相互接触的方式排列,相邻的子光栅125之间也可以设置间隙。本方案通过相邻的两个所述子光栅的间距为L’的排列方案,结合光栅调节件182实现开启部分子光栅,以使工作状态下的子光栅阵列中,相邻的工作状态的子光栅的中心之间的距离L的范围为:3mm≦L≦5mm。
一种实施方式中,所述瞳孔检测件182用于检测瞳孔的尺寸,具体而言,瞳孔检测件182的数量为两 个,分别设置在近眼显示设备1000的左镜片10L和右镜片10R上,瞳孔检测件182邻近耦出光栅12设置,使得瞳孔检测件182可以更精确地检测瞳孔的尺寸。所述控制单元181用于接收所述瞳孔检测件182的信号。控制单元181还用于驱动所述光栅调节件183。光栅调节件183包括行控制器1831和列控制器1832,行控制器1831用于控制各行子光栅125对应的区域的开关,列控制器1832用于控制各列子光栅125对应的区域的开关。所述光栅调节件183用于控制所述耦出光栅12的部分行或部分列的开启或关闭,以使部分子光栅进入工作状态,且能够保证工作状态下的相邻的子光栅之间的间距L的范围为:3mm≦L≦5mm,以实现子光栅出射细光束,且进入瞳孔的细光束的数量为一个,从而解决VAC问题。
参阅图60,图60示意性地表达了一种工作状态的子光栅125分布。图60中显示的耦出光栅12的架构为:通过光栅调节件的行控制器和列控制器关闭了部分行及部分列的子光栅,关闭的部分行和部分列的子光栅未显示在图中,显示的子光栅125均为开启状态的,即工作状态的子光栅125。对于工作状态的子光栅125而言,各行中,相邻的子光栅125之间的间距为L;各列中,相邻的子光栅之间的间距为L。本方案采用可切换光学元件,通过控制子光栅的开关,使得工作状态的子光栅可以响应不同尺寸的瞳孔,例如,瞳孔尺寸变化的情况下,能够通过光栅调节件去调节工作状态的子光栅的间距,提高图像显示效率。本方案无需根据现实内容进行虚像距的切换,可以降低系统功耗。
方案五:具渐变折射率的镀膜光栅
本申请具体实施方式提供的光波导通过耦入光栅将光机产生的各个视场的光线注入光波导内,光线将在光波导内经由全反射传播,并由耦出光栅耦出光波导,进入人眼成像。同时,光波导允许周围景象通过光波导,并进入人眼成像,从而使得使用者可以同时观察到真实景像及虚拟信息(图像信息)。本申请提供的光波导可以应用于车载HUD、头戴式增强现实眼镜等。
一种实施方式中,耦入光栅通过衍射效应将光线耦入光波导,耦出光栅也可以通过衍射效应将光线耦出光波导。因此,如何提升耦入效率和耦出效率,以提升光波导的光学利用率为业界研究的方向。
一种实施方式中,可以通过光栅的折射率的变化实现提升衍射效率及光学利用率,例如,体全息光栅通过调配全息材料的配方,获得更高的平均折射率和折射率调制度,得到具有不同折射率分布的体全息光栅,但是通过改变全息材料获得理想的平均折射率和折射率调制度,得不到理想的效果,主要原因是受限于全息材料的特性。具体而言,全息材料通常由聚合物单体和惰性聚合物构成,这些材料的折射率较低(1.45-1.65),导致材料的平均折射率也比较低。并且,由于光聚合的过程中聚合物单体和惰性聚合物不会完全分离,导致体全息材料制成的光栅结构的折射率调制度也较低(低于0.15),因此,体全息光栅无法获得理想的平均折射率和折射率调制度。
一种实施方式中,本申请通过提供一种光波导,通过对光波导的光栅结构设计,具体为将光栅结构一个周期的结构设计为沿光栅结构矢量方向层叠设置的具有不同的折射率的层结构,通过光栅结构的一个周期中具有不同折射率的设计,实现光栅结构折射率变化,来提升光波导的衍射效率和光学利用率。
参阅图61,一种实施方式中,光波导10A包括波导基底19和形成在波导基底19上的光栅结构14。图61示意性地表达了波导基底19和光栅结构14之间的一种具体的位置关系和结构组成部分,并不代表光波导10A的具体结构形态。图61所示的实施方式中,光栅结构14突出在波导基底19的表面,波导基底19呈平板状,波导基底19的表面可以呈平面状。光栅结构14可以为耦入光栅,也可以为耦出光栅或中继光栅。光线经过光栅结构14耦入光波导10A,且能够在波导基底19中进行全反射传播。波导基底19为具有较高折射率的材料,例如波导基底19的折射率在1.38-2.6之间。波导基底19的材料可以包括金属氧化物。波导基底19的材料可以为:MgF2、TiO2、氮化硅、氮化镓、高折树脂材料中的任意一种,波导基底19的材料也可以为混合材料,混合材料包括上述材料中的两种或多种的混合。波导基底19可以为单层结构,波导基底19也可以为多层结构,例如每一层材料不同,构成的复合层结构。
所述光栅结构14包括多个芯结构141和膜结构142,所述膜结构142的折射率和所述芯结构141的折射率不同,多个芯结构141沿所述光栅结构14的矢量方向依次间隔排列,图61中光栅结构的矢量方向为从左向右的方向。相邻的芯结构141之间间隔预设的距离,此预设的距离范围内用于设置膜结构142。沿所述光栅结构14的矢量方向,芯结构141的两侧均用于设置膜结构142。如图61所示,排列在最左侧的芯结构141的左侧具有膜结构142,排列在最右侧的芯结构141的右侧也具有膜结构142。其它实施方式中,膜结构142可以只设置在相邻的芯结构141之间,即排列在最左侧的芯结构141的左侧及排列在最右侧的芯结构142的右侧均不设置膜结构。
图61所示的实施方式中,相邻的芯结构141之间的区域内被膜结构142填满,也就是说,相邻的芯结构141之间的区域内没有任何间隙(或间隔空间,没有空气存在于光栅结构14的内部)。本实施方式中,光栅结构14在其矢量方向上是连续延伸无缝隙的结构,这样的结构设计,使得光栅结构14的内部没有任何空气,有利于保证光栅结构14的衍射效率,也有利于保证光栅结构14的不受环境因素影响,例如空气中灰尘、水气等会影响光栅结构14的功能及寿命。
图62为图61中部分光栅结构14和部分波导基底19的分解示意图,通过将芯结构141和膜结构142分离,可以方便标示芯结构141和膜结构142的详细的结构特征。结合参阅图61和图62,各芯结构141包括连接端1412、自由端1413和侧面1411,连接端1412连接至波导基底19,自由端1413和连接端1412在芯结构141的高度方向上相对设置,芯结构141的高度方向可以理解为垂直于波导基底19的表面的方向。侧面1411连接在连接端1412和自由端1412之间。膜结构142包括膜主体1421,第一端部1422和第二端部1423,膜主体1421包覆芯结构141的侧面1411,也可以理解为,膜主体1421贴合在侧面1411上,膜主体1421和侧面1411接触且结合为一体。第一端部1422和第二端部1423分别位于膜主体1421的两端,第一端部1422连接波导基底19。一种实施方式中,第二端部1423的端面和芯结构141的自由端1413的端面共面,所有芯结构141的自由端1411和膜结构142的所述第二端部1423共同构成光栅结构14的端面143。
本方案通过光栅结构14的芯结构141和膜结构142的折射率不同来提升衍射效率和光学利用率。通过芯结构141的自由端1411和膜结构142的第二端部1423共同构成光栅结构14的端面,使得光栅结构14的衍射效率更好,光栅结构14只有在其矢量方向上具有折射率不同的芯结构和膜结构,在光栅结构14的高度方向上,由于在光栅结构14的端面位置,芯结构141的自由端1411和膜结构142的第二端部1423均外露状态,即光栅高度方向上芯结构141的外部未被膜结构142包覆,光栅结构14的衍射效率可以得到保证。假若芯结构的自由端被膜结构包覆,包覆在芯结构自由端的部分膜结构会产生光栅结构高度方向上的衍射效果,但是,光栅结构高度方向上的衍射由于与光栅结构的矢量方向不同,会对光栅结构矢量方向上的衍射形成负面影响,即会降低光栅结构的衍射效率。
图63所示为光栅结构14的端面143的示意图,参阅图63,光栅结构14的端面143为由芯结构141的自由端1413的端面和膜结构142的第二端部1423的端面所构成的间隔排列的条纹状架构。结合参阅图61和图63,光栅结构14的端面143为平面状架构。
一种实施方式中,在相邻的所述芯结构之间,所述膜结构包括至少三层膜层,至少三层所述膜层层叠设置在相邻的所述芯结构的所述侧面之间,至少三层所述膜层具有不同的折射率,沿所述光栅结构的矢量方向,至少三层所述膜层的折射率呈正弦分布的渐变趋势。
如图61和图62所示,相邻的芯结构141之间具有三层膜结构142,具体而言,这三层膜结构142分别为第一膜层142A、第二膜层142B和第三膜层142C,沿光栅结构14的矢量方向,第一膜层142A、第二膜层142B和第三膜层142C层叠设置在相邻的芯结构141的侧面1411之间。第一膜层142A和第三膜层142C分别结合在相邻芯结构141的侧面1411上,第一膜层142A和第三膜层142C均和芯结构141的侧面1411直接接触连接,第二膜层142B位于第一膜层142A和第三膜层142C之间。
第一膜层142A、第二膜层142B和第三膜层142C具有不同的折射率。光栅结构14的矢量方向可以理解为相邻的两个芯结构141中的一个芯结构141的侧面1411朝向另一个芯结构141的侧面1411的方向。第一膜层142A的折射率、第二膜层142B的折射率、第三膜层142C的折射率呈正弦分布可以理解为:这三个折射率的变化趋势可以为从大至小再至大的变化,或者可以为从小至大再至小的变化。芯结构141和膜结构142之间具有折射率差,膜结构142的内部,相邻的膜层之间亦具有折射率差。
一种实施方式中,第一膜层142A的折射率和第三膜层142C的折射率均大于第二膜层142B的折射率,第一膜层142A的折射率和第三膜层142C的折射率可以相等,此实施方式中,芯结构141的折射率大于第一膜层142A的折射率,芯结构141的折射率大于第三膜层142C的折射率。本实施方式中,各部分结构的折射率范围可以为但不限于如下描述:芯结构141的折射率范围可以为1.38-2.6,第一膜层142A和第三膜层142C的折射率范围可以为1.38-2.6,第二膜层142B的折射率范围可以为1.0-2.6。
另一种实施方式中,第一膜层142A的折射率和第三膜层142C的折射率均小于第二膜层142B的折射率,第一膜层142A的折射率和第三膜层142C的折射率可以相等,此实施方式中,芯结构141的折射率小于第一膜层142A的折射率,芯结构141的折射率小于第三膜层142C的折射率。本实施方式中,各部分结构的折射率范围可以为但不限于如下描述:芯结构141的折射率范围可以为1.0-2.6,第一膜层142A和第三膜层142C的折射率范围可以为1.38-2.6,第二膜层142B的折射率范围可以为1.38-2.6。
图64为对比正弦渐变折射率分布的光栅结构和单独芯结构的光栅结构的入射角和衍射效率对应关系的曲线示意图,其中,单独芯结构的光栅结构指的是光栅结构的折射率为单一的设计,在一个光栅结构的周期内,光有一个单独的芯结构,而且芯结构的折射率是固定值;正弦渐变折射率分布的光栅结构指的是光栅结构的一个周期内包括芯结构和膜结构,芯结构和膜结构折射率不同,从而产生正弦渐变折射率分布。参阅图64,可以看出,在所需的入射角度处,(如图64中入射角度为0度附近,可以根据需要设定到其他入射角度处),正弦渐变折射率光栅可以具有更高的衍射效率及更窄的半高全宽,可以满足特定角度入射效率的调制需求,从而提高整个系统的光效。
一种实施方式中,在相邻的所述芯结构之间,所述至少三层膜层具有不同的厚度,厚度最大的所述膜层邻接所述芯结构,且所述芯结构的厚度大于厚度最大的所述膜层的厚度,如图61所示的实施方式中,第一膜层142A和第三膜层142C的厚度相同,二者可以通过同一道镀膜工艺制作在芯结构141的侧面上,从制作角度而言,具有亦于实现,节约工时的优势。第二膜层142B的厚度与第一膜层142A的厚度不相等,图61所示的具体实施方式中,第二膜层142B的厚度小于第一膜层142A的厚度。
一种实施方式中,芯结构141的厚度也可以小于厚度最小的膜结构142中的膜层的厚度,厚度最小的所述膜层邻接所述芯结构141。第二膜层142B的厚度也可以大于第一膜层142A的厚度。
图65为本申请一种实施方式提供的光波导的部分光栅结构和部分波导基底的分解示意图。参阅图65,芯结构141的厚度小于第一膜层142A的厚度,芯结构141的厚度也小于第三膜层142C的厚度,第一膜层142A的厚度和第三膜层142C的厚度可以相等,第二膜层142B为膜结构142中厚度最大的一层。
本申请提供的光栅结构14的覆盖在芯结构141的侧面1411上的膜结构142的厚度可以从数埃至数纳米。一个芯结构141和相邻的芯结构141之间的膜结构142构成一个光栅周期。
参阅图61,在相邻的芯结构141之间的一个周期内,膜结构142的层数为寄数层,例如,膜结构142的层数为三层、五层、七层等。位于中间位置的一层为中间层,其余层可以对称分布在中间层的两侧,例如,第一膜层142A和第三膜层142C对称分布在第二膜层142B的两侧,这里所述的对称分布可以理解为物理尺寸上的对称及折射率方面的对称。物理尺寸上的对称布置有利于实现制作难度低,易保证良率的优势,折射率方面的对称有利于实现衍射效率和对应的入射角的精确的控制。
一种实施方式中,相邻的芯结构141之间的部分膜结构142呈无缝隙结构。可以理解为,相邻的芯结构141之间的空间被膜结构142填满,没有留下任何空隙。如图61所示,第一膜层142A和第三膜层142C贴覆在芯结构141的侧面1411上,第二膜层142B的两侧分别与第一膜层142A和第三膜层142C直接连接。
本申请提供的光栅结构14中的芯结构141可以为闪耀光栅或者倾斜光栅。芯结构141内任意位置的折射率均相同,芯结构141可以通过纳米压印工艺或刻蚀工艺制作在所述波导基底19上。膜结构142通过镀膜工艺形成,具体而言,可以通过两次或多次镀膜制程制作出多层膜结构,例如图61所示的实施方式中,共使用了两次镀膜制程,第一膜层142A和第三膜层142C通过第一次镀膜制程制作,第二膜层142B通过第二次镀膜制程制作。膜结构142也可以通过原子层沉积(ALD)、浸润提拉、旋涂等其它工艺制作。
一种实施方式中,膜结构142的其中一层膜层通过将膜结构142中的一个膜层细分为两种不同折射率的第一子膜和第二子膜,以得到目标折射率方案。参阅图66,以第二膜层142B的制作过程为例,第二膜层142的目标折射率为N,但是直接制作一层膜层,得到精确的折射率为N的膜层从工艺层面较难实现,影响制作的因素可能包括材料的选择、膜层厚度控制等等。一种实施方式,第二膜层142B包括一一对应交替间隔排布的多层第一子膜142B1和多层第二子膜142B2,所述第一子膜142B1的折射率为N1,所述第二子膜142B2的折射率为N2,所述多层第一子膜142B1和所述多层第二子膜142B2构成的所述第二膜层142B的折射率为N,N1<N<N2。第一子膜142B1和第二子膜142B2的材料可以不同,厚度也可以不同。第一子膜142B1和第二子膜142B2可是通过同样的制程工艺实现,这两个膜层的制作过程简单易行,容易控制各自的折射率,最终得到的第二膜层142B的折射率N可以满足设计需求。
图61所示的光波导10A的制作方法,结合图67和图68,具体描述如下。
参阅图67,在波导基底19上制作芯结构141。一种实施方式中,如图67中上面的图示,芯结构141突出于波导基底19的表面,另一种实施方式中,如图67中下面的图示,芯结构141内嵌于波导基底19中,也就是说,芯结构141形成在波导基底19的内凹部分。可以通过刻蚀工艺在波导基底19上制作芯结构141,通过刻蚀工艺制作的芯结构141,可以获得的芯结构141的折射率范围可以为1.38-2.6,例如芯结构141的材料为MgF2时,其折射率可以为1.38,芯结构141的材料为TiO2时,其折射率可以为2.6。也可以通过纳米压印技术在波导基底19上制作芯结构141,可以获得光栅芯层的折射率范围约为1.4-2.6。
如图67所示,一种具体实施方式中,光栅结构14的光栅周期p的范围为200-800nm,光栅高度h的范围为5-3000nm,光栅倾角θ的范围约为0-60°。一个典型的实施例中,周期p=400nm,光栅高度h=600nm,光栅倾角θ为55°,光栅芯层的宽度p0=130nm。
参阅图68,图68中从上至下分别为a图、b图和c图,用这三个图表达在图67所示的结构的基础上完成光栅结构制作的三个步骤。
如图68中的a图所示,制作好芯结构141后,使用镀膜工艺制作膜结构,先在芯结构141的表面制作形成膜层I,膜层I包覆在芯结构141的外围,将芯结构141罩设在波导基底19上,此状态下,芯结构141的侧面1411、自由端1413均被膜层I覆盖。膜层I的厚度p1可以为70nm。在相邻的芯结构141之间的区域内,膜层I之间形成缝隙g。膜层I的折射率可以为1.38-2.6。
如图68中的b图所示,制作好膜层I后,制作膜层II,膜层II的制作方法可以与膜层I的制作方法相同,例如,均通过镀膜工艺制作。膜层II完全包覆膜层I,且膜层I所形成的缝隙g中也被膜层II填充。膜层II制作好后,在光栅结构的高度方向上,芯结构141的自由端1413的上方依次层叠膜层I和膜层II。膜层II的折射率可以为1.38-2.6。膜层I的厚度p2可以为65nm。
如图68中的c图所示,制作好膜层Ii后,通过化学机械抛光(CMP)等工艺将光栅结构的表面的膜结构打磨平整,使得芯结构141的自由端1413外露。经过打磨的工艺,使得膜结构142形成不完全包覆芯结构141的状态,膜结构142形成了膜主体和分别位于膜主体两端的第一端部和第二端部,第二端部和芯结构141的自由端1413共面,所有所述芯结构的所述自由端和所述膜结构的所述第二端部共同构成所述光栅结构的端面。
一种实施方式中,当芯结构的折射率选为1.9时,膜结构中的膜层I的折射率选为2.1,膜层II的折射率选为2.3时,可以获得平均折射率n=2.1,折射率调制度Δn=0.4,此方案获得的光栅结构具有衍射效率高的优势。
参阅图69,一种实施方式中,可以在芯结构141的基础上,镀制折射率渐变膜层的膜结构142,可以获得较好的角度、波长选择特性。其中,在波导基底19上,通过刻蚀工艺或者纳米压印工艺来获得高折射率SRG光栅结构(即芯结构141),SRG光栅结构(即芯结构141)的折射率可以达到2.0甚至更高,比如使用TiO2作为波导基底19,通过刻蚀工艺获得的SRG光栅(即芯结构141)折射率最高可以达到2.6。然后通过多层镀膜工艺形成膜结构142,可以逐渐渐变折射率,每层镀膜的厚度可以为数埃至数纳米,最低折射率可以为空气层,则Δn最大可以达到1.6。芯结构141具有较高折射率(例如:折射率范围为1.38-2.6之间)时,两个芯结构141之间具有多层材料构成的膜结构142,膜结构142的折射率的分布为正弦变化,如图69中的正弦曲线所示:折射率逐渐变低之后再逐渐变高,折射率渐变的膜结构142的最低折射率可以达到1.38,最高可以达到2.6。当芯结构141的折射率较低(例如:折射率范围为1.38-2.6之间)时,两个芯结构141之间折射率变化仍为正弦分布,折射率会逐渐变高之后再逐渐变低。本方案能够获得好处在于:可以极大提高光栅平均折射率及折射率调制度,平均折射率可以达到2.0以上,Δn最大可以达到1.0以上,能够扩大参数范围,为后续光波导设计提供了合适的优化空间。
类似地,其它实施方式中,如果使用低折材料制作芯结构141,然后使用高折材料来进行膜结构142的加工,可以获得类似的折射率变化仍为正弦分布的光栅结构。
参阅图70,一种实施方式中,相邻的芯结构141之间的膜结构142的中间位置具有膜间隙144。间隙144中可以为空气,空气的折射率为1。本实施方式中,芯结构141的折射率大于膜结构142的折射率,膜结构142的折射率大于1.38,这样在相邻的芯结构141之间,光栅结构的折射率呈正弦分布的渐变趋势。本实施方式中,膜结构142可以通过一次镀膜的方式形成在芯结构141表面。
图71所示为本申请一种实施方式提供的光波导的立体示意图,示意性地表达了波导基底19的表面设置的光栅结构,图71只是示意性地表示耦出光栅11、中继光栅13及耦出光栅12设置在波导基底19上,并不限定耦出光栅11、中继光栅13及耦出光栅12的具体结构和位置关系,以及三者与波导基底19之间的连接关系、位置关系等等。图71所示的实施方式中,耦出光栅12分布在波导基底19的两侧,即在波导基底19的顶面和底面均设有耦出光栅12,位于波导基底19顶面的耦出光栅12的光栅倾角和位于波导基底19底面的耦出光栅12的光栅倾角可以不同,这样耦出光栅12可以对不同方向的光线发生衍射,以使更多的光线被耦出波导基底19,提升衍射效率。
图72所示为本申请一种实施方式提供的光波导的平面示意图。参阅图72,一种实施方式中,耦入光栅11包括第一耦入结构11A和第二耦入结构11B,所述第一耦入结构11A和所述第二耦入结构11B相对设置且分别位于所述波导基底19的顶面和底面,所述第一耦入结构11A和所述第二耦入结构11B具有不 同的光栅倾角。第一耦入结构11A和第二耦入结构11B可以对不同方向的光线发生衍射,以使更多的光线被耦入波导基底19,即,第一耦入结构11A和第二耦入结构11B结合以实现大角度范围内的高衍射效率。
第一耦入结构11A和第二耦入结构11B可以为不同的光栅结构、可以具有不同的光栅高度、光栅占空比等光栅参数。第一耦入结构11A和第二耦入结构11B可以采用图61或图69或图70所示的实施方式提供的光栅结构。第一耦入结构11A和第二耦入结构11B可以具有不同的光栅芯层(即芯结构可以不同)。第一耦入结构11A和第二耦入结构11B可以具有不同的膜结构(即光栅镀膜层),也可以具有相同的膜结构(即光栅镀膜层)。
第一耦入结构11A的芯结构的折射率可以高于所述第二耦入结构11B的芯结构的折射率,所述第一耦入结构11A的膜结构的折射率可以高于所述第二耦入结构11B的膜结构的折射率。一种具体的实施方式中,第一耦入结构11A具有较高折射率的芯结构(例如芯结构的折射率范围为:1.9-2.3),并且第一耦入结构11A的膜结构的折射率也为高折射率材料,例如膜结构的折射率范围为:2.1-2.6。第一耦入结构11A能够对[-20°,10°]角度范围内的光线响应。第二耦入结构11B采用较低折射率的芯结构(例如芯结构的折射率范围为:1.5-1.9),并且第二耦入结构11B的膜结构的折射率范围为:1.7-2.1。第二耦入结构11B能够对[10°,20°]角度范围内的光线响应。第一耦入结构11A和第二耦入结构11B同时作用,能够实现对[-20°,20°]入射角度范围内的光线的响应。
图72所示的实施方式中,耦出光栅12也具有分布在波导基底19的顶面和底面的光栅结构,一种实施方式中,耦出光栅12和耦入光栅11均采用图61或图69或图70所示的实施方式提供的光栅结构。耦出光栅12的膜结构可以与耦入光栅11的膜结构不同,例如材料不同、折射率不同、厚度不同等等。
一种情况下,使用图72所示的实施方式,能够实现较窄的角带宽,可以使光波导满足特定的设计需求。具体而言,对于耦出光栅12而言,一块光栅区域只需要对特定方向光进行调制作用时,即耦出特定方向的光至人眼,因此,此种情况下,需要角带宽更窄。在特定的角度上能够获得更高的衍射效率。如图72所示,人眼看到耦出光栅12的左侧投射的光线(耦出光栅12左侧三条虚线示意性地表达耦出光栅12左侧投射的光线),只需要耦出光栅12的左侧部分区域将光线耦出,因此,这部分耦出光栅需要对该出射角度具有高的衍射效率即可,对这部分光栅所需的衍射效率的角带宽就比较窄。类似地,对于中间部分的光线(耦出光栅12中间位置三条实线示意地表达耦出光栅12中间位置投射的光线),对耦出光栅中间区域的衍射效率,也是需要较窄的角带宽,获得较高的衍射效率。对于耦出光栅右侧的光线(耦出光栅12右侧位置三条点划线示意地表达耦出光栅12中间位置投射的光线),同样需要针对耦出光栅右侧耦出的光线具有较窄带宽,获得较高的衍射效率。
图73所示为本申请一种实施方式提供的光波导的平面示意图。图73所示的实施方式中,中继光栅13位于耦入光栅11和耦出光栅12之间,中继光栅13分布在波导基底19的顶面和底面,图73中显示了分布在顶面和底面的中继光栅13,顶面的中继光栅13和底面的中继光栅13可以具有相同的结构形态,不同的光栅倾角,顶面的中继光栅13和底面的中继光栅13可以构成以中轴线12L为中心的对称分布架构,中轴线12L可以理解为耦入光栅11的中心和耦出光栅12的中心之间的连线。
如图73所示,一种实施方式中,耦出光栅12采用图61或图69或图70所示的实施方式提供的光栅结构。耦出光栅12包括第一区12A和第二区12B,所述第一区12A相较所述第二区12B距离所述耦入光栅11更近,所述第一区12A中的所述耦出光栅14的芯结构和膜结构之间的折射率差为第一值,所述第二区12B中的所述耦出光栅12的芯结构和膜结构之间的折射率差为第二值,所述第一值小于所述第二值。图73中用矩形虚线框表示第一区12A和第二区12B,图73中的两个矩形虚线框只是示意性地表达第一区12A和第二区12B的位置关系,并不代表第一区12A和第二区12B的具体的外轮廓的结构形态和尺寸。第一区12A和第二区12B可以邻接,即二者边界接触,或称为共用边界。第一区12A和第二区12B之间也可以像图73所示的间隔设置,即二者之间通过其它部分的耦出光栅隔开。
参阅图73和图74,一种实施方式中,中继光栅13包括第一中继结构13C和第二中继结构13D,所述第一中继结构13C和所述第二中继结构13D分别设置在所述波导基底19的顶面和底面,所述第一中继结构13C和所述第二中继结构13D可以具有不同的矢量方向。通过第一中继结构13C和第二中继结构13D具有不同的矢量方向的设置,能够使得更多的光进入耦入光栅12,提升光利用率。
一种实施方式中,对于中继光栅13而言,不同位置的膜结构具有不同的镀膜参数,镀膜参数可以为但不限于:折射率、厚度、密度等等。
如图74所示,一种实施方式中,中继光栅13采用图61或图69或图70所示的实施方式提供的光栅 结构。中继光栅13包括第三区13A和第四区13B,所述第三区13A相较所述第四区13B距离所述耦入光栅11更近,所述第三区13A中的所述中继光栅13的所述芯结构和所述膜结构之间的折射率差为第三值,所述第四区13B中的所述中继光栅13的所述芯结构和所述膜结构之间的折射率差为第四值,所述第三值小于所述第四值。本实施方式中,耦出光栅12也可以为图73所示的耦出光栅12的架构,即耦出光栅12也可以包括第一区12A和第二区12B,所述第一区12A中的所述耦出光栅14的芯结构和膜结构之间的折射率差为第一值,所述第二区12B中的所述耦出光栅12的芯结构和膜结构之间的折射率差为第二值,所述第一值小于所述第二值。本方案中,中继光栅13第四区13B中的芯结构和膜结构之间的折射率差(即第四值)小于第一值。
一种具体的实施方式中,在第三区13A中,中继光栅13的芯结构的折射率为2.4,膜结构的折射率为1.9,第三值(即第三区13A中的中继光栅13的所述芯结构和所述膜结构之间的折射率差)为0.5。在第四区13B中,中继光栅13的芯结构的折射率为2.4,膜结构的折射率为1.5,第四值(即第四区13B中的所述中继光栅13的所述芯结构和所述膜结构之间的折射率差)为0.9。第三区13A中的光栅效率较第四区13B中的光栅效率低。
一种实施方式中,沿着中继光栅13的矢量方向,芯结构和膜结构之间的折射率差呈渐变的趋势,折射率差逐渐增大,中继光栅的折射率也是逐渐增大。
概括而言,本申请为了获得均匀的亮度分布,光波导需要衍射效率不断提高,例如沿着耦入光栅向耦出光栅延伸的方向,衍射效率需要具有增加的趋势。为了实现衍射效率的逐渐提高,本申请可以通过逐渐提高折射率差值,提高光栅的衍射率,折射率的提高也有助于提高光栅的衍射效率。
图71、图72、图73和图74所示的实施方式中的耦出光栅11、中继光栅13及耦出光栅12中的至少部分均可以包括图61或图69或图70所示的实施方式提供的光栅结构。
本申请一种实施方式提供的光波导作为光线传播的媒介应用在近眼显示设备中,光波导包括波导基底和形成在波导基底上的耦入光栅和耦出光栅,耦入光栅将光机传送的光线耦入光波导后,光线需要能够在波导基底中进行全反射传播。为了实现较大的视场角,需要提升波导基底的折射率,因此,若要得到较好的视场角及光学效果的图像,波导基底需要具有较高的折射率。对于波导基底而言,折射率越大,重量越大,但是较大的重量会影响近眼显示设备佩戴的舒适性。对于光波导的设计而言,如何减重为重要的研发方向。
一种实施方式中,本申请使用低折射率的介质层和形成在介质层顶面和底面的光栅结构共同构成波导基底,通过形成在介质层顶面和底面的光栅结构对光线进行全反射传播。这里所述的光栅结构不是耦入光栅,也不是耦出光栅和中继光栅,其功能只是实现光线在波导基底中全反射传播。低折射率的介质层具有轻量化的优势,低折射率的介质层和形成在介质层顶面和底面的光栅结构所形成的波导基底的整体的重量也可以控制在较小的范围内。
方案六:体全息光栅构成全反射传播
图75为本申请一种实施方式提供的光波导的示意图。参阅图75,一种实施方式提供的光波导包括耦入区10Ai、耦出区10Ao和光线传播区10Ap。耦入区10Ai设有耦入光栅11,耦入光栅11用于接收光机20发射的入射光线,可以理解为,光机20发射的光线入射至耦入光栅11上形成入射光线。所述入射光线进入所述光波导10A后在所述光线传播区10Ap中全反射。耦出光栅12用于耦出光线,使得光线投影至人眼,形成虚拟图像。
图75所示的实施方式中,光波导10A的波导基底为低折射率的材料,在光线传播区10Ap内,所述光波导10A包括介质层194和位于介质层194两侧的第一光栅层19A和第二光栅层19B,具体而言,第一光栅层19A和第二光栅层19B分别形成在介质层194的顶面和底面。本实施方式通过分布在介质层194的两侧的第一光栅层19A和第二光栅层19B实现光线在光线传播区10Ap的全反射传播,而单独的介质层194是无法实现光线的全反射传播的。介质层194的折射率小于等于1.5,本方案通过对介质层194的折射率的范围的约束,能够保证介质层194具有密度低重量轻的优势,有利于实现光波导10A的轻量化设计。本方案通过限定所述第一光栅层和所述第二光栅层中的至少一个具有不同周期,使得所述第一光栅层和所述第二光栅层中的至少一个即可以透射环境光,又可以全反射光波导内部传输的光线。
一种具体的实施方式中,介质层194的材料为低折材料,例如玻璃或树指,介质层194的厚度为可以为:大于等于0.1mm且小于等于1mm,具体而言,介质层194的厚度及折射率的设置可以与近眼显示设 备中的光机的出瞳大小和FOV大小相匹配。介质层194也可以为空气。
一种实施方式中,光波导10A中的波导基底均由介质层194构成,即,耦入区10Ai中用于承载耦入光栅11的部分波导基底、耦出区10Ao用于承载耦出光栅12的部分波导基底与光线传播区10Ap中的介质层194为一体式的结构,材料相同,折射率相同,可以通过同一道制作工艺加工形成。
一种实施方式中,入射光线的带宽小于等于5nm。入射光线可以为激光光源。本实施方式通过限定入射光线的带宽范围,使得光机20发射至耦入光栅11上的光线为窄带宽光源,有利于保证光波导10A投影至人眼形成的虚像的图像质量。
本申请提供的光机20投射至耦入光栅11的入射光线为较窄波长带宽的入射光线,具体指的是针对光机进入耦入光栅的光线,限定入射波长带宽,其目的是为了保证对环境的观测产生较小的影响。假设入射光线波长带宽为1nm(532nm~533nm),第一光栅层19A和第二光栅层19B针对该波长设计,对其他波长如520nm等正常透过,不影响环境的观测。但假设入射光线的波长带宽较宽,例如为20nm(520~540nm),环境光打到第一光栅层19A和第二光栅层19B上时会发生衍射,也就是说外界环境假设我们观察的是白画面,那在520~540nm波段的外界环境光有部分光就被衍射走了,透过率相比于其他波段的透过率低了,就影响了颜色的配比,也就是颜色失真了,从而影响观察外界环境。
对于本申请提供的光波导,光机20投射至耦入光栅11上的入射光线,经过耦入光栅11衍射后角度与入射光线的角度分开,需要在介质体194中传送,在光线传播区10Ap中进行全反射传播。对于近眼显示设备而言,一种实施方式中,耦入光栅11的周期满足条件为:λ/d>2*sin(FOVx),sin(FOVx)+λ/d<n_base*sin(75°),其中,λ为入射至所述耦入光栅的入射光线的波长,d为耦入光栅的周期,FOVx为入射至所述耦入光栅的入射光线的水平方向的最大入射角度,n_base指的是所述耦入光栅11对应的波导基底的折射率,图75所示的实施方式中,可以理解为:耦入光栅11所对应的波导基底为耦入光栅11下方的部分介质层和部分第二光栅层,即n_base为耦入光栅11所对应的波导基底为耦入光栅11下方的部分介质层和部分第二光栅层的折射率。
图76所示为本申请一种实施方式提供的光波导的光栅周期的K空间示意图。参阅图76,n=1的折射率在K空间所围成虚线圆圈为能够在介质n=1中传播的角度范围,同样能够在波导基底中传播的角度范围即为n=n_base围成的实线圆圈,光机出射的光的角度范围可以描述为K空间图中的方框区域,经耦入光栅11耦入后,角度发生改变,在K空间中的表现为方框发生平移,平移的距离与入射波长和耦入光栅周期相关,等于λ/d,平移后角度范围不能发生相交(若角度范围发生相交,会造成角度的混叠,从而产生鬼像),也不能超出n_base的圆圈(若超出n_base的圆圈,光线会无法在介质n_base中进行传播),因此耦入光栅的光栅周期需要满足条件:λ/d>2*sin(FOVx),sin(FOVx)+λ/d<n_base*sin(75°)。
一种实施方式中,光波导10A上的耦出光栅、中继光栅(若光波导包括位于耦入光栅和耦出光栅之间的中继光栅)的周期也需要满足前述耦入光栅的光栅周期需要满足的条件。
图77所示为本申请一种实施方式提供的光波导的光栅周期的K空间示意图。参阅图77,耦入光栅11、中继光栅13和耦出光栅12的周期方向和大小需要形成闭合的K空间,满足此条件,可以保证光波导投射的虚拟图像不会产生畸变,即能够保证图像的真实性,提升光波导的图像显示效果。
基于图77所示的K空间示意图,一种实施方式中,如图78所示,本申请提供的光波导10A包括耦入光栅11、中继光栅13和耦出光栅12,在光路传输的方向上,所述中继光栅13位于耦入区10Ai和耦出区10Ao之间,所述光线传播区10Ap中的第一光栅层19A和第二光栅层19B位于所述耦入光栅11和所述耦出光栅12之间,且所述光线传播区10Ap中的第一光栅层19A和第二光栅层19B包围所述中继光栅13。即中继光栅13的位置不需要设置第一光栅层19A和第二光栅层19B。图78中,耦入光栅11、中继光栅13和耦出光栅12外围的剖面线表示第一光栅层19A和第二光栅层19B,也可以表示光线传输区10Ap。本实施方式中,耦出光栅12可以为一维光栅。图78所示的实施方式中,耦入光栅11、耦出光栅12、中继光栅13可以为不同类型的光栅;耦入光栅11、耦出光栅12、中继光栅13中的任何一个与第一光栅层19A和第二光栅层19B均可以为相同类型的光栅,例如,可以为体全息光栅;耦入光栅11、耦出光栅12、中继光栅13、第一光栅层19A和第二光栅层19B均可以为体全息光栅。
一种实施方式中上,如图79所示,耦出光栅12可以为二维光栅,所述光线传输区10Ap位于所述耦入光栅11和所述耦出光栅13之间,所述第一光栅层19A和所述第二光栅层19B填充所述耦入光栅11和所述耦出光栅12之间的所有区域,可以理解为,本实施方式提供的光波导10A不具有中继光栅,耦入光栅11耦入的光线,经过所述第一光栅层19A和所述第二光栅层19B的全反射传播至耦出光栅12处。图79中,耦入光栅11和耦出光栅12外围的剖面线表示第一光栅层19A和第二光栅层19B,也可以表示光线 传输区10Ap。图78所示的实施方式中,耦入光栅11、耦出光栅12、中继光栅13可以为不同类型的光栅;耦入光栅11、耦出光栅12中的任何一个与第一光栅层19A和第二光栅层19B均可以为相同类型的光栅,例如,可以为体全息光栅;耦入光栅11、耦出光栅12、第一光栅层19A和第二光栅层19B均可以为体全息光栅。
图78和图79中,虽然第一光栅层19A和第二光栅层19B为分布在介质层两侧的,但由于图78和图79表示各光栅结构之间的位置关系,并不区分各光栅结构在光波导厚度方向上位于介质层的顶面还是底面。
确定光机20出射的入射光线的FOV角度范围和耦入光栅11的光栅周期后,就可以得到经耦入后的传播角度范围θ1~θ2,需经第一光栅层19A和第二光栅层19B发生衍射向前传播,相应角度对应的第一光栅层19A和第二光栅层19B中作用的周期为λ/(2*n_base*sin(θ))。假设入射光线的FOV范围为-15~15°,入射波长532nm,介质层194的折射率为n=1.3,根据上述计算方法耦入光栅11的周期范围为533.7nm~1.028um,假设耦入光栅11周期设定为600nm,则相应的衍射的角度为28.9°~61.8°,对应的第一光栅层19A和第二光栅层19B的周期为233.2nm~423.4nm。入射光线的FOV范围越大,在耦入光栅11的周期和介质层194的折射率保持不变的情况下,衍射角度的上限越大,则第一光栅层19A和第二光栅层19B的周期的下限就越小。
概括而言,一种具体的实施方式中,光机20投射至耦入光栅11上的入射光线的FOV范围越大,所述第一光栅层19A和所述第二光栅层19B中的至少一个所具有的周期数量越多。一种具体的实施方式中,光机20投射至耦入光栅11上的入射光线的FOV范围越大,在所述耦入光栅11周期和介质层194的折射率保持不变的情况下,衍射角度的上限越大,所述第一光栅层19A和所述第二光栅层19B中的至少一个所具有的周期的数量的下限就越小。
第一光栅层19A和第二光栅层19B为体全息光栅的情况下,本申请使用复用体全息光栅的方式实现即对光波导内的光线进行全反射传播,又能透射环境光。此种情况下,第一光栅层19A和第二光栅层19B的光栅周期的数量则取决于所需的角度分辨率,假设所需角度分辨率为18PPD(pixel per degree),入射角度范围为-15~15°,则需要的光栅周期数量为18*30=540个,所需角度分辨率越高,入射FOV范围越大,需要的光栅周期数量越多。目前的FOV较小的12°,PPD所需最低18PPD,则第一光栅层19A和第二光栅层19B的周期数目至少大于216个。
图75所示的实施方式中,第一光栅层19A和第二光栅层19B中的至少一个具有不同的周期。若第一光栅层19A和第二光栅层19B均为单一的周期,且二者周期相同,二者工作于相同的反射衍射级次,导致观察外界的环境光透过率较低,也就是说,使用者能看到耦出光栅投射出的虚拟图像,便是不能清楚地看到近眼显示设备外界的环境。本申请通过限制第一光栅层19A和第二光栅层19B中的至少一个具有不同的周期,一方面能够对多个视场角的入射光进行全反射传播,使得更多的光线能量进入耦出光栅,可以提升衍射效率;另一方面,能够保证环境光的透过率,使得使用者不但能清楚地看到耦出光栅投射的虚拟图像,还能清楚地看到近眼显示设备外界的环境。
一种实施方式中,第一光栅层19A和第二光栅层19B均具有不同的周期。本方案通过限定第一光栅层和第二光栅层均具有不同的周期,能够提升光波导的透光性。
具体而言,第一光栅层19A和第二光栅层19B均为体全息光栅。本方案通过复用不同周期的体全息光栅,使得光线传播区10Ap即能够对进入光波导的入射光线进行全反射,还能对环境光具有较好的透过率。而且相对其它光栅类型(例如闪耀光栅、倾斜光栅),休全息光栅具有轻薄的优势。因此本方案有利于光波导10A的轻量化的设计。
一种实施方式中,如图75所示,介质层194为平板状结构,形成在介质层194的顶面和底面的所有的光栅结构均可以为体全息光栅,这里所述的所有的光栅结构包括耦入光栅11、耦出光栅12、第一光栅层19A和第二光栅层19B。
具体而言,第一光栅层19A和第二光栅层19B中的一个所具有的周期的数量取决于光波导10A所需的角度分辨率和光机20的入射光线的FOV的大小。周期是光栅结构的重要特征,不同周期对应的是不同的布拉格角度,也就是不同的入射角度。因此,具有不同的周期的光栅结构的衍射效率高于只有一种周期的光栅结构的衍射效率,而且具有不同周期的光栅结构即可以对光波导内的光线进行全反射,又可以透射环境光。
一种实施方式中,第一光栅层19A和第二光栅层19B的周期范围为:大于等于100nm且小于等于700nm。对于复用体全息光栅的方案形成的第一光栅层19A和第二光栅层19B而言,其周期是和入射角度相对应的,通过限定大于等于100nm且小于等于700nm的光栅周期范围可以在保证入射角度的前提下,获得较高的 衍射效率。
一种实施方式中,第一光栅层19A的材料的体积收缩率范围和第二光栅层19B的材料的体积收缩率范围为:小于等于0.1%。本方案通过较小的体积收缩率的光栅结构,可以减小第一光栅层19A和第二光栅层19B的横向和纵向的变化率,从而减小周期、厚度和倾角的变化,保证第一光栅层19A和第二光栅层19B的设计和实际作用的角度和效率没有较大偏差。
图75所示的实施方式中,耦入光栅11、第一光栅结构195和耦出光栅12位于介质层194的顶面,在介质层194的底面为第二光栅层19B,具体而言,第二光栅层19B不只覆盖光线传播区10Ap的介质层194,还覆盖耦入区10Ai和耦出区10Ao的介质层,以使得介质层194的底面的一侧的光波导10A的表面具有较好的平面度。在介质层194的顶面的一侧,耦入光栅11背离介质层的表面、第一光栅层19A背离介质层194的表面和耦出光栅12背离介质层194的表面可以形成共面架构,以使得介质层194的顶面的一侧的光波导10A的表面具有较好的平面度。
一种实施方式中,光波导10A还包括第一保护层151和第二保护层152,第一保护层151位于第一光栅层19A背离介质层194的一侧,第一保护层151覆盖在第一光栅层19A、耦入光栅11和耦出光栅12的表面,第一保护层151用于保护第一光栅层19A、耦入光栅11和耦出光栅12,使得第一光栅层19A、耦入光栅11和耦出光栅12免受外界粉尘、空气或水气的侵蚀。第二保护层152覆盖在第二光栅层19B的表面,用于保护第二光栅层19B,使得第二光栅层19B免受外界粉尘、空气或水气的侵蚀,从而有利于保证光波导的衍射效率及光学性能。
本申请具体实施方式提供的光波导,在其光线传输区10Ap中,利用第一光栅层和第二光栅层全反射传播耦入进来的图像同时保证整体光波导的环境光的透过率,保证人眼能够正常观察外界环境。一种具体的方案中,第一光栅层和第二光栅层膜厚可以为:>20um。第一光栅层和第二光栅层配合的入射光线的带宽<5nm(即窄带宽的入射光线),实现对耦入的光线的全反射传播。第一光栅层和第二光栅层的制作过程可以通过多次曝光获得,以使第一光栅层和第二光栅层具有多个周期,以实现即能全反射传播入射光线,又能提升环境光的透过率。
图80所示为单光栅衍射效率示意图,图80中,横轴代表入射角度,纵轴代表衍射效率,通过图80,可以看到本申请可以获得一个在角度空间上在很小的角度范围内具有很高衍射效率的体全息光栅。复用体全息光栅是多个周期的光栅曝光在同一层中形成的,图80所示的单光栅衍射效率,其中单光栅指的是其中某个周期的一个光栅。基于本申请提供的复用体全息光栅架构,针对每一个周期的光栅都可以使其针对特定角度进行高效率的衍射。
通过计算模拟保证不同角度的反射衍射效率,具体地,可通过目标函数MF=sum((DE_s-1)2+(DE_p-1)2)+sum(DE_t^2),式中DE_s和DE_p分别代表目标角度的s偏振光和p偏振光入射到第一光栅层19A和第二光栅层19B后的反射衍射效率,1是我们需要的效率目标值,即全反射向前传播,DE_t为其他角度打到第一光栅层19A和第二光栅层19B的衍射效率,将该目标函数最小作为优化光栅结构的目标,这个目标代表着我们期望得到波导反射向前传播图像的同时保证环境光的透过率。
通过模拟退火算法或者是基因算法等全局优化算法进行优化,得到具体的第一光栅层19A和第二光栅层19B的参数值和优化后的效果。以衍射角度范围(25~45)为例,目标优化效果如图81和图82所示。
图81所示为波长带宽的示意图,图81中,横轴代表入射波长,纵轴代表衍射效率,通过图81可以看到:优化后的复用体全息光栅仅对很窄带宽的波长范围具有高衍射效率,对其余波段均是高效率透过,不影响观察外界环境。
图82所示为角度带宽的示意图,图82中,横轴代表入射到复用体全息光栅上的入射角度,纵轴代表衍射效率,通过图82可以看到:仅在应用的角度范围内,本申请提供的复用体全息光栅具有高效率的衍射特性,同样保证了全反射传播所需角度的同时,对其他外界环境角度均高效率透射。
以三个视场为例(不同视场用不同颜色的线条所表示),曝光示意图如图83所示。光线传播区10Ap上的第一光栅层19A和第二光栅层19B需要将打到该区域的光衍射后保持原本的方向和角度继续向前传播,根据第一光栅层19A和第二光栅层19B的复用特性,需要曝光多个不同的光栅针对不同视场的入射光作用。曝光的角度为入射光来的方向以及需要的衍射方向,两个方向曝光形成的光栅即为针对该入射光方向的,进行多次曝光后形成的第一光栅层19A和第二光栅层19B即可针对波导内的多个视场进行衍射至所需的衍射方向,使之经过该区域全反射后向前传播至耦出光栅处,正常耦出至人眼。
在制作第一光栅层19A和第二光栅层19B的过程中,多次曝光的制作流程,参阅图83,第一次曝光是以角度1进行曝光,第二次曝光是以角度2进行曝光,第三次曝光是以角度3进行曝光,以此类推,制 作第一光栅层19A和第二光栅层19B的过程中可以进行多次曝光。多次曝光的过程中,曝光角度可以依次增大,如图83所示,角度1<角度2<角度3。
参阅图84,一种实施方式中,在耦入区10Ai,耦入光栅11分布在介质层194的两侧,能够提升入射光线的耦入效率。一种实施方式中,位于介质层194的顶面的耦入光栅11和位于介质层底面的耦入光栅11可以具有不同的倾角,这样可以使得耦入光栅11能够耦入更大角度范围的入射光线。一种实施方式中,在耦出区10Ao,耦出光栅12分布在介质层194的两侧,能够提升入射光线的耦出能量,使得更多的光线耦出至人眼,获得较佳的图像质量。一种实施方式中,位于介质层194的顶面的耦出光栅12和位于介质层底面的耦入光栅12可以具有不同的倾角,这样可以使得耦出光栅12能够耦出更大角度范围的光线。
参阅图85和图86,一种实施方式中,光波导10A包括功能区10AA和边缘区10AE,功能区10AA为执行光波导10A的对入射光线的衍射、全反射传播及耦出光线的功能。边缘区10AE包围功能区10AA,边缘区10AE可以透射环境光,边缘区10AE和功能区10AA拼接共同形成近眼显示设备的镜片的形态。边缘区10AE位置不需要配置第一光栅层和第二光栅层。本方案提供的光波导通过功能区和边缘区的结合,边缘区可以为较轻的材质,有利于实现光波导的轻量化。
具体而言,所述边缘区10AE的折射率小于所述功能区10AA的折射率,或者,所述边缘区10AE的材料和所述功能区10AA的材料不同。边缘区10AE可以为低折射率材料,或密度低的材料,这样有利于近眼显示设备整体的轻量化设计。
图85所示的实施方式中,功能区10AA中包括耦入光栅11、中继光栅13、耦出光栅12和光线传播区10Ap中的第一光栅层195和第二光栅层196,本实施方式中,耦入光栅11和中继光栅13之间的区域,及中继光栅13和耦出光栅12之间的区域为光线传播区10Ap。图86所示的实施方式中,功能区10AA中包括耦入光栅11、耦出光栅12和光线传播区10Ap中的第一光栅层195和第二光栅层196,本实施方式中,耦入光栅11和耦出光栅12之间的区域为光线传播区10Ap。
图75所示的实施方式提供的光波导10A可以为单层单面光栅的光波导结构,即,光波导只有一层介质层,且耦入光栅和耦出光栅只设置在介质层的一面。图84所示的实施方式提供的光波导10A可以为单层双面光栅的光波导结构,即,光波导只有一层介质层,且耦入光栅和耦出光栅只设置在介质层的两面。
其它实施方式中,本申请提供的光波导也可以为多层单面架构,或多层双面架构。“多层”指的是光波导具有两层或两层以上的层叠设置的介质层。“多层单面架构”指的是光波导具有两层或两层以上的介质层,且每层介质层只有一面设置光栅结构。“多层双面架构”指的是光波导具有两层或两层以上的介质层,且每层介质层的两面均设置光栅结构。其它实施方式中,光波导的层数可以为两层,例如其中一层传送红色光和蓝色光,另一层传送蓝色光和绿色光。其它实施方式中,光波导的层数也可以为三层,例如这三层分别传送红色光、蓝色光和绿色光。本方案限定了光波导的单层架构或三层架构,在任意一种架构下,均可以使用第一光栅层和第二光栅层作为光线传播区的全反射传播的媒介,本方案具有灵活性好的优势。
图87示意性地表达了一种三层单面的光波导架构。参阅图87,光波导10A包括三层介质层194,这三层介质层194层叠设置。每层介质层194的顶面和底面设置的光栅结构相同。其它实施方式中,不同层的介质层的顶面或底面所设置的光栅结构也可以不同。图87所示的实施方式中,每一层介质层194及其顶面和底面的耦入光栅11、耦出光栅12、第一光栅层195A、第二光栅层195B所构成的架构与图75所示的光波导架构相同。最上层的介质层194与耦入光栅11用于耦入红色入射光线R,中间一层的介质层194与耦入光栅11用于耦入绿色入射光线G,最下层的介质层194和耦入光栅11用于耦入蓝色入射光线B。三层架构的所有的耦出光栅12均将耦出光线投射至人眼,以使人眼看到彩色的虚拟图像。
对于图87所示的实施方式而言,由于每一层架构传送的光线的颜色不同,而且每一层只传送一种颜色的光线,第一光栅层195和第二光栅层196为体全息光栅的情况下,在制作第一光栅层195和第二光栅层196时,每一层的周期数量可以少于图75所示的实施方式中的第一光栅层195和第二光栅层196的周期数量。因此本实施方式可以降低每一层架构的第一光栅层195和第二光栅层196的曝光次数,降低了工艺难度。
方案七:增透层
本申请一种实施方式提供的光波导为衍射光波导,衍射光波导就是利用光栅的衍射特性来设计“光路”,让光在设计好的路径上传播,将微投影系统(例如近眼显示设备中的光机)发出的光导入人眼。衍射光栅为具有周期性结构的光学元件,是衍射光波导最为核心的部分。根据光栅类型的不同,又可以将衍射光波 导分为两类:表面浮雕光栅波导和体全息光栅波导。
全息材料制作的全息光栅具有多种好处,如角度选择性、波长选择性及高的衍射效率。光在体全息光栅波导中的传播过程与表面浮雕光栅波导基本相同。不同之处在于,体全息光栅不是通过“雕刻”,而是通过两束相干光形成的明暗相间的干涉条纹来对基板上的光感应薄膜进行曝光,进而在分子层面形成具有折射率差的周期性空间分布。
增强现实(AR)技术是备受关注的人机交互技术。近眼显示设备中的镜片上的光波导可以采用体全息材料制作光栅结构,以获得较高的衍射效率。参阅图88,一种实施方式提供的光波导10A包括波导基底19和形成在波导基底19的表面的光栅层197,光栅层197为体全息材料,光栅层197用于制作光栅结构,例如耦入光栅11和耦出光栅12。波导基底19可以为高折射率材料,用于在制作光栅层197的过程中承载光栅层197,还用于光线的全反射传播。具体而言,入射光线经耦入光栅11进入波导基底19,并在波导基底19内全反射传播,且传播至耦出光栅12时,由耦出光栅12耦出至人眼。光波导10A还用于环境光的透射,人眼通过光波导10A不只要看到耦出光栅12耦出的虚拟图像,还要看到外界的环境。
在体全息材料中,扩大不同组分折射率差异是获得高折射率调制度的关键。但是,根据“相似相容”原理,高的折射率差异意味着低的物质相容性,使不同组分间容易发生微区团聚,形成大的聚合物颗粒,从而易发生光散射,导致低的稳定性、高的雾度。体全息材料的雾度严重影响外界视窗的清晰度和观感。图88所示的实施方式中,由于光栅层197为体全息材料且覆盖在波导基底19的表面,耦入光栅11和耦出光栅12的位置为体全息材料制作的光栅结构,除耦入光栅11和耦出光栅12之外的光栅层197的其它区域为体全息材料覆盖在波导基底上,这部分体全息材料及耦入光栅11和耦出光栅12位置处的体全息材料均容易产生高雾度的问题。
本申请一种实施方式提供一种光波导结构,通过改变体全息材料的内部结构或内部组分的排列方式,能够降低体全息材料的雾度。
参阅图89,一种实施方式提供的光波导10A包括波导基底19和增透层16,增透层16形成在波导基底19的表面,增透层16包括体全息材料。具体而言,增透层16为光栅层197的至少部分,光栅层197为设置在波导基底19的表面用于制作光栅结构(例如耦入光栅11和耦出光栅12)的层结构,光栅层197材料为体全息材料,可以理解的是,形成在波导基底19上的光栅结构(例如耦入光栅11和耦出光栅12)为体全息光栅。图89所示的实施方式中,增透层16位于耦入光栅11和耦出光栅12之间,增透层16不具有衍射光线的功能,只具有透射光线的功能,而且通过增透层16的内部结构可以解决其内部不同组分之间发生微区团聚,形成大的聚合物颗粒,从而易发生光散射,导致低的稳定性、高的雾度的问题。
图90为图89中I部分的放大示意图,通过图90可以清楚地看到增透层16的内部结构的设置方案。如图90所示,增透层16包括折射率不同的高折射率相区161和低折射率相区162,高折射率相区161和低折射率相区162层叠设置在述波导基底19的表面,高折射率相区161和低折射率相区162为互相分离的不同区域,高折射率相区161的折射率范围为:1.5-2.0,低折射率相区162的折射率范围为1.1-1.5,高折射率相区161中的组分和低折射率相区162组分不同。组分不同可以理解为材料类型不同,相同组分的材料之间不会发生微区团聚,无法形成大的聚合物颗粒,从而可以使得光波导具有低的雾度,提高光波导的透光性。
本方案通过将增透层16内部结构形成相间分布的高折射率相区161和低折射率相区162,而且高折射率相区161和低折射率相区162的组分不同。可以理解为,在增透层16内相同组分的材料聚集在一个相区内,例如,高折射率相区161中的组分为高分子聚合物和纳米粒子,而低折射率相区162中的组分为单体所形成的高分子聚合物,即次高分子聚合物。这样高分子化合物和次高分子化合物分开,而不是混杂在一起,不容易形成微区团聚现象。
一种实施方式中,如图90所示,高折射率相区161的数量为多个,低折射率相区162的数量也为多个,从个高折射率相区和多个低折射率相区沿垂直于波导基底19表面的方向相间分布。相间分布可以理解为ABABAB的排列方式。低折射率相区162层叠设置在相邻的高折射率相区161之间,或高折射率相区162层叠设置在相邻的低折射率相区161之间。图90所示的实施方式中,高折射率相区161和低折射率相区162的数量均为三个,在波导基底19的表面上,三个高折射率相区161分别位于第一、第三、第五层,三个低折射率相区162分别位于第二、第四、第六层。
其它实施方式中,高折射率相区161和低折射率相区162的数量可以均为一个,高折射率相区161层叠设置在低折射率相区162和波导基底19之间,或,低折射率相区162层叠设置在高折射率相区161和波导基底19之间。高折射率相区161和低折射率相区162的数量也可以均为两个、四个或更多个。
本申请提供的光波导中,增透层的材料为体全息材料。一种实施方式中,体全息材料的主体为高分子聚合物材料,所述高分子聚合物材料的主要元素组成包括:C、H、O、N、S、P中的一种或几种或全部。
一种实施方式中,体全息材料还包括纳米粒子,纳米粒子的直径为:1nm~50nm。一种实施方式中,至少部分所述纳米粒子分布在所述高折射率相区,分布在所述高折射率相区的所述纳米粒子为二氧化钛、二氧化锆、硫化锌、碳量子点中的一种或几种或全部。一种实施方式中,至少部分所述纳米粒子分布在所述低折射率相区,分布在所述低折射率相区的所述纳米粒子为二氧化硅、氟化镁中的一种或全部。所述纳米粒子的体积分数含量为0~60%。本方案通过限制纳米粒子的体积分数来控制高折射率区和低折射率相区的形成以及二者的折射率,且解决光波导雾度的问题。具体而言,纳米粒子不能太多,太多会造成纳米粒子自身团聚,雾度增加;纳米粒子也不能太少,太少会减少不同相区之间的折射率差异。
高折射率相区和低折射率相区为依次层叠相间分布在波导基底19的表面的层结构,层结构沿垂直于波导基底的表面方向上的尺寸为层结构的厚度。一种实施方式中,所述高折射率相区所形成的层结构的厚度和所述低折射率相区所形成的层结构的厚度相同。一种实施方式中,所述高折射率相区所形成的层结构的厚度和所述低折射率相区所形成的层结构的厚度也可以不同。
一种实施方式中,每个高折射率相区的厚度范围为100nm~1000nm。每个低折射率相区的厚度范围也可以为100nm~1000nm。例如,各所述高折射率相区的厚度或各所述低折射率相区的厚度为:200nm。本方案通过厚度范围的限制来控制增透层能够透过光的波长范围,不同厚度的增透膜对应不同的波长范围。
图89所示的实施方式中,在波导基底19的表面,只有非光栅区19S的位置(图中示意性地标示在耦入光栅11和耦出光栅12之间的区域)的体全息材料为增透层16,而耦入光栅11和耦出光栅12位置处,只是利用体全息材料制作形成的衍射光栅架构,并不具有增透层的架构。图89所示的实施方式能降低非光栅区19S位置的雾度,提升光均匀性和环境光线的透过率。
其它实施方式中,也可以在光栅结构所在的位置设置增透层结构,也就是说,光栅结构的位置即具有衍射光栅的结构也具有增透层结构,衍射光栅结构的光栅矢量方向及周期的设置为了满足衍射光学性能,例如耦入光栅位置处的光栅矢量方向及周期的设置为了满足将入射光线耦入波导基底中,耦出光栅位置处的光栅矢量方向及周期的设置为了满足将光线耦出至人眼。若光波导具有中继光栅,中继光栅位置处也可以同时具备增透层的架构。
参阅图91,一种实施方式中,光波导10A的增透层16形成在非光栅区19S和耦出光栅12所在的位置。在非光栅区19S中的增透层与图89所示的实施方式中的增透层16的结构相同。图92为图91中的耦出光栅12位置的放大示意图。参阅图92,在耦出光栅12的位置处,增透层16和耦出光栅12形成共体结构17,共体结构17包括沿耦出光栅12的矢量方向排列的光栅微结构,共体结构17还包括沿光波导10A的法线方向相间分布的高折射率相区161和低折射率相区162。本方案通过在耦出光栅12的位置处设置增透层16,能够提升耦出光栅12的透光率,耦出光栅12不仅能将光波导10A中的光线耦出至人眼,还能透过环境光,本方案提供的光波导的耦出光栅12的位置具有较好的透光性。
图92所示的实施方式中,增透层16设置在耦出光栅12的所有的区域,即,增透层16和耦出光栅12具有相同的外轮廓。
参阅图91和图92,所述耦出光栅12与所述波导基底19的连接的面为所述耦出光栅12的耦出底面12S1,所述耦出光栅12背离所述波导基底19的面为所述耦出光栅12的耦出顶面12S2,和所述耦出光栅12形成所述共体结构17的部分所述增透层16形成在所述耦出底面12S1和所述耦出顶面12S2之间。通过复用全息技术在耦出光栅12的位置制作增透层16。本方案限定了耦出光栅和增透层形成共体结构的具体的架构,本方案不需要在耦出光栅之外的区域增加体全息材料,而是基于耦出光栅本身进行双光束曝光得到增透层结构,能够保证或尽量不影响耦出光栅的衍射效率。若在耦出顶面之外增加材料制作增透层,增加的材料部分会影响耦出光栅的衍射效率。
其它实施方式中,增透层16也可以只设置在耦出光栅12中的部分区域。例如:如图93所示,增透层16的左边缘位于耦出光栅12的内部,增透层16的左侧有部分耦出光栅12的位置并没有设置增透层16。增透层16的右边缘与耦出光栅12的右边缘重合。
参阅图94,一种实施方式中,光波导10A中的增透层16只设置在耦出光栅12所在的位置,增透层16和耦出光栅12构成共体结构,而在非光栅区19S并不设置增透层。本方案主要是针对耦出光栅12的位置提高环境光的透光性。小面积的制作增透层,有利于在获得需要的光波导的方案下,节约制作成本。
图95为形成增透层与光栅结构构成的共体结构的具体的制作方法的示意图。其中包括第一种制作方法M1和第二种制作方法M2,图95中上方矩形框内的示意图为第一种制作方法M1,图95中下方矩形框 内的示意图为第二种制作方法M2。参阅图95,对于增透层16和光栅结构(例如耦出光栅12、耦入光栅或中继光栅)形成共体结构17的方案而言,光栅结构(以耦出光栅12为例)为体全息材料形成在波导基底的表面,通过双光束曝光工艺形成增透层16和光栅结构(以耦出光栅12为例)。
制作增透层16的双光束曝光工艺中的双光束之间的夹角为第一角度θ1,具体而言,两个光束与增透层16之间的夹角为第一角度θ1的二分之一,即两个光束对称分布在增透层16的两侧,两个光束构成的夹角的角平分线OC平行于波导基底的表面(或增透层所在的平面),这样,双光束曝光就会形成与波导基底层叠设置的增透层的高折射率相区和低折射率相区。
制作光栅结构的双光束曝光工艺中的双光束的夹角为第二角度θ2。以耦出光栅12为例,在曝光形成耦出光栅12的过程中,双光束中的两个光束形成的夹角的角平分线OC与波导基底的表面形成夹角,这样曝光后形成具有衍射功能的耦出光栅12。可以理解的是,根据不同的光栅类型,调节双光束和波导基底的表面之间的夹角,调节角平分线OC和波导基底之间的夹角,可以制作出不同类型的光栅结构。
第一角度θ1和第二角度θ2可以不同。
图95所示的图示中,将制作增透层16的双光束曝光步骤和制作耦出光栅12的双光束曝光步骤分开表示,具体的制作过程中,这两个步骤的顺序可以调换,也就是说,可以先曝光形成增透层16,再在此基础上曝光形成耦出光栅12;也可以先曝光形成耦出光栅12,再在此基础上曝光形成增透层16。本方案只需要调整双光束曝光的角度,借用一套设备即可以在同一个区域中实现增透层16和光栅结构(以耦出光栅12为例)的共体结构,具有制作工艺简单,制作成本低的优势。
本申请提供一种光波导的制作方法,用于制作前述具有增透层的光波导。
参阅图96,一种实施方式中,光波导的制作方法包括如下步骤:
提供基板,此基板为光波导的波导基底,例如基板可以为玻璃材料。一种实施方式中,基板的折射率需要满足能够实现光线在其中的全反射传播,基板还需要具有透光性,以透过环境光。
在基板的表面设置材料层,材料层包括体全息材料。通过涂布的方式在所述基板的表面设置所述材料层,例如,所述涂布方式包括旋涂、提拉浸涂、喷涂、凹版涂布、反向辊涂、刀辊涂层、计量棒涂布、槽模涂布、浸渍、幕帘涂层、气刀涂层中的任一种。
对具有材料层的基板进行前处理。前处理的步骤包括:25~100℃高温处理、低压处理、避光处理、室温放置处理。具体而言,材料层的材料配方中含有溶剂,前处理需要除去溶剂,有些溶剂沸点高,因此,需要低压处理。低压具体可以理解为低于1个大气压。
执行双光束曝光工艺,使得所述材料层形成具有高折射率相区和低折射率相区相间分布的结构。
固化成型,以使所述材料层被调制为所述波导基底上的增透层。固化成型的步骤包括高温固化成型和光照固化成型,所述高温固化成型的温度为40~150℃,所述光照固化成型的光强为0.1~5000mW cm-2,所述光照固化成型的波长范围为254nm~1000nm,用于所述光照固化成型的光的类型包括UVA、UVB、UVC、可见光、红外光波段中和任一种。
本申请通过在基板上涂布材料层,并限定材料层为体全息材料,通过双光束曝光工艺将材料层调制为具有高折射率相区和低折射率相区的增透层,以实现降低光波导雾度,提升光均匀性及透光率。
一种实施方式中,材料层包括高分子聚合物、单体、光引发体系、溶剂,所述高分子聚合物为含有C、H、O、N的分子量大于1000的聚合物,所述单体包括丙烯酸酯类、丙烯酰胺类、含巯基化合物、烯丙基类、乙烯基类化合物中的至少一种,所述光引发体系用于吸收激光能量,且形成活性物质,以使所述活性物质与所述单体反应,将所述单体转化为次高分子聚合物。
一种实施方式中,所述高分子聚合物包括聚醚、聚醋酸乙烯酯、聚醋酸乙烯-丙烯共聚物、聚乙烯、聚丙烯、聚氯乙烯、聚对苯二甲酸乙二酯、聚苯乙烯、聚碳酸酯、聚氨酯、聚酯多元醇、醋酸纤维素、聚乙烯醇中的至少一种。
所述丙烯酸酯类化合物包括聚乙二醇丙烯酸酯、3-羟丙基丙烯酸酯、五溴苯基丙烯酸酯、乙氧基化三羟甲基丙烷三丙烯酸酯、丙烯酸异辛酯、含硫丙烯酸酯、含苯丙烯酸酯、含苄基丙烯酸酯、含联苯丙烯酸酯、和季戊四醇四丙烯酸酯中的至少一种以及其对应的甲基丙烯酸酯类似物;
所述丙烯酰胺类化合物包括甲基醇丙烯酰胺、N-苄基甲基丙烯酰胺和N,N-二甲基丙烯酰胺中的至少一种,所述含巯基化合物包括丙硫醇、双(3-巯基丙酸)乙二醇、三羟甲基丙烷三(3-巯基丙酸酯)和四(3-巯基丙酸)季戊四醇酯中的至少一种;
所述烯丙基类化合物包括烯丙基脲、烯丙基乙醚、烯丙基苯基醚、1-烯丙基哌嗪和三烯丙基异氰脲酸酯中的至少一种;
所述乙烯基类化合物包括N-乙烯基咔唑、N-乙烯基咪唑、二溴-N-乙烯基咔唑、三溴-N-乙烯基咔唑、四溴-N-乙烯基咔唑、N-乙烯基吡咯中的至少一种。
图97为本申请一种实施方式提供的光波导的制作方法的过程中,材料层进行双光束曝光过程中,各组分的变化示意图。参阅图97,材料层在进行双光束曝光之前,如图97中的左图,材料层中包括高分子聚合物、单体和纳米粒子,高分子聚合物和单体随机排布,纳米粒子分散在高分子聚合物和单体之间。一种实施方式中,双光束曝光工艺的光源包括两束扩束的相干激光,所述两束扩束的相干激光相互干涉形成光强呈正弦波分布,以在所述材料层上形成高光强区和低光强区,所述高光强区所述光引发体系吸收的能量多于所述低光强区所述光引发体系吸收的能量,以使得所述高光强区的所述活性物质多于所述低光强区的所述活性物质,以使所述高分子聚合物和所述次高分子聚合物分离,参阅图97中的中间的图示,高分子聚合物和纳米粒子按箭头指示的方向移动。这样,就会形成所述高折射率相区与所述低折射率相区相间分布架构,如图97中的右图所示,高分子聚合物和单体相分离,形成折射率为n1的高折射率相区和折射率为n2的低折射率相区;或者形成折射率为n1的低折射率相区和折射率为n2的高折射率相区。
一种实施方式中,双光束曝光工艺中的双光束之间的夹角为第一角度,第一角度范围以为:10度-180度,例如,双光束之间的夹角为120度。本方案限制双光束曝光工艺中的双光束之间的夹角范围,可以得到高折射率相区和低折射率相区相平行且层叠设置的架构,增透层的矢量方向可以理解为高折射率相区和低折射率相区的层叠方向,也可以为垂直于波导基底表面的方向。
一种实施方式中,光波导的制作方法还包括通过双光束曝光工艺制作光栅结构,通过夹角为第二角度的双光束进行曝光,形成所述光栅结构,第二角度和第一角度不同,以形成不同的矢量方向。所述光栅结构和至少部分所述增透层可以位于所述基底上的同一位置。光栅结构可以为光波导的耦入光栅、耦出光栅或中继光栅。光栅结构的类型为体全息光栅。
本申请提供的光波导通过基于休全息材料制作增透层,增透层的结构为高低折射率相间分布的材料,其中,高低折射率相区由体全息材料填充,高折射率组分填充至高折射率相区,低折射率组分填充至低折射率相区。本申请能够在提高体全息材料折射率调制度的同时,降低了体全息材料的雾度,提高了光波导的光学性能,可以将透过率提升至98%以上。由于体全息材料中的高低折射率组分发生相分离,且各自成相区,避免了组分间的相互接触、抑制聚合物颗粒形成,最终使体全息材料雾度降低50%以上,可以低至0.1。同时,体全息材料的折射率调制度高达0.2。在AR领域,折射率调制度的提升有助于增加AR眼镜的FOV,对于折射率调制度为0.2的体全息材料,可以制备FOV高达40°的AR眼镜。
一种实施方式中,双光束曝光的夹角为120°,曝光次数为1次,形成高折射率相区、低折射率相区相间分布的增透层结构,每个高折射率相区或每个低折射率相区的厚度为200nm。由于增透层仅增加光线的透过率,不会影响光机投射至光波导的光线在光波导中的全反射传播。增透层能够降低体全息材料的雾度,提升光波导的光学性能。光波导的入射光线的FOV为40°,光均匀性为0.3,雾度为0.5%,透过率范围为80%-100%,例如,透过率为95%。
方案八:填充层保护光栅结构
本申请提供的光波导是引导光波在其中传播的介质装置,其轻薄和外界光线的高穿透特性被认为是近眼显示设备(例如增强现实(AR)眼镜)的一种必选解决方案。光波导大体上可分为几何光波导和衍射光波导两类,其中几何光波导又叫阵列光波导,其通过阵列反射镜堆叠实现图像的输出和动眼框的扩大,衍射光波导可分为表面浮雕光栅波导和体全息光栅波导。在近眼显示设备中,具有表面浮雕光栅的光波导被广泛使用。
一种实施方式中,参阅图98,光波导10A包括波导基底19和盖板15,波导基底19上具有光栅结构14,此光栅结构14可以为耦入光栅、耦出光栅或中继光栅。盖板15用于遮挡波导基底19和光栅结构14,盖板15为光波导10A的最外层结构,例如,盖板15可以为玻璃材质。波导基底19和盖板15层叠设置,且二者之间需要连接,本实施方式中,波导基底19和盖板15之间通过点胶结构154(胶粘剂)实现固定连接。点胶结构154高度约几十微米左右。波导基底19和盖板15之间具有间隙15G,此间隙15G中存在 空气。
由于波导基底19与盖板15之间留有几十微米的间隙15G,当外力作用在盖板15上时,间隙15G的存在,容易造成波导基底19和光栅结构14的损坏。点胶的方式密封固定盖板15和波导基底19,使得波导基底19和盖板15之间的间隙15G中存在空气,会导致波导基底19长期接触水氧的风险。空气中的水、氧气容易加速波导基底19和光栅结构14的老化。空气中的水蒸气附着在盖板15上,外界温差变化使盖板15发生雾化,影响人眼视线。
若用点胶方式密封波导基底19和盖板15,会导致波导基底19和盖板15之间存在内外压差,外界环境改变(压强过大)导致盖板15开裂。点胶贴合的方式存在胶粘剂不均匀、胶粘剂渗透到波导基底19影响波导基底19的折射率。
本申请一种实施方式通过在波导基底上的光栅结构的外围设置填充层,利用填充层保护光栅结构和波导基底,实现对光波导的保护及提升光波导的寿命和光学性能。
一种实施方式中,参阅图99,光波导10A包括第一波导基底19S1、第一光栅结构14S1和第一填充层15S1,第一光栅结构14S1形成于第一波导基底19S1的表面,第一填充层15S1和第一波导基底19S1层叠设置,第一填充层15S1覆盖第一波导基底19S1的表面,第一填充层15S1和所述第一波导基底19S1共同形成封闭的包围架构19C,第一光栅结构14S1位于包围架构19C内,以使第一光栅结构14S1与此包围架构19C的外界的空气隔离,第一填充层15S1的折射率和空气的折射率之间的差值小于等于0.2。
第一波导基底19S1可以为无机材料、高折树脂材料等等,本申请不限定第一波导基底19S1的具体材料,第一波导基底19S1可以为任意能够实现光全反射传播的材料或材料的组合。
具体而言,第一填充层15S1为透明材质,具有较好的透光性,例如透光性可以大于等于80%。第一填充层15S1可以为低折射率的材料,低折射率体现在第一填充层15S1的折射率接近空气的折射率,例如:第一填充层15S1的折射率和空气的折射率之间的差值小于等于0.2。本方案通过设置第一填充层15S1,实现对第一波导基底19S1和第一光栅结构14S1的保护,使得第一波导基底19S1和第一光栅结构14S1与外界空气隔离,能够保证第一波导基底19S1和第一光栅结构14S1避免长期接触水氧环境,解决了光波导10A易老化、被腐蚀及雾化等问题,还能够抵御外界冲击力避免光波导损坏,本申请提供的实施方式能够保证光波导10A的使用寿命和光学性能。
图99所示的实施方式中,第一填充层15S1的外部可以不设置盖板,也就是说,第一填充层15S1可以作为光波导10A的最外层结构。第一填充层15S1可以全面覆盖第一波导基底的表面。第一光栅结构14S1可以为闪耀光栅、直光栅、倾斜光栅或体全息光栅。第一光栅结构14S1可以为耦入光栅、耦出光栅或中继光栅。
参阅图100,一种实施方式中,光波导10A包括第一盖板15A、第一波导基底19S1和第一填充层15S1,第一光栅结构14S1形成在第一波导基底19S1上,第一填充层15S1设置在第一盖板15A和第一波导基底19S1之间,第一填充层15S1和所述第一波导基底19S1共同形成封闭的包围架构19C,第一光栅结构14S1位于包围架构19C内,以使第一光栅结构14S1与此包围架构19C的外界的空气隔离,第一填充层15S1的折射率和空气的折射率之间的差值小于等于0.2。本方案提供了一种具有第一盖板的光波导架构,通过第一填充层填充在第一盖板和第一波导基底之间,使得第一盖板和第一波导基底之间无气隙,第一填充层对第一盖板提供支撑力,能够防止第一盖板受外部应用破损。
本方案中,第一盖板15A和第一波导基底19S1固定连接,第一填充层15S1背离第一波导基底19S1的表面和第一盖板15A的内表面贴合。图100所示的实施方式相较图99所示的实施方式,增加了第一盖板15A的结构,图100所示的实施方式中的第一填充层15S1的厚度可以较薄,只需要满足填充第一盖板15A和第一波导基底19S1之间的间隙即可。本方案提供了第一盖板和第一波导基底之间的固定方案,点胶固定的结构易于操作,而且,由于第一填充层已经覆盖了第一波导基底的大部分面积,胶水不会对第一波导基底的光学性能带来破坏性的影响。
一种具体的实施方式中,所述第一盖板15A和所述第一波导基底19S1之间通过点胶结构154固定连接,所述点胶结构154分布在所述第一填充层15S1的周围。一种实施方式中,点胶结构154在第一填充层15S1的外围包围形成封闭的环绕第一填充层15S1的结构,点胶结构154构成第一填充层15S1外围的密封结构。一种实施方式中,点胶结构154为多个间隔分布的连接结构且依次间隔排列在第一填充层15S1的周围。
其它实施方式中,所述第一盖板15A和所述第一波导基底19S1之间也可以通过其它的固定方式连接,例如螺丝固定。
图100所示的实施方式中,第一波导基底19S1的表面为平面状,第一光栅结构14S1突出设置在第一波导基底19S1的表面。第一填充层15S1包围第一光栅结构14S1的顶面和侧面,第一光栅结构14S1的底面连接第一波导基底19S1。
参阅图101,一种实施方式中,第一光栅结构14S1也可以内嵌在第一波导基底19S1中,图101所示的实施方式中的第一波导基底19S1的表面和第一盖板15A之间的垂直间距小于图100所示的实施方式中的第一波导基底19S1的表面和第一盖板15A之间的垂直间距。图101所示的实施方式中,第一光栅结构14S1的底面和侧面均位于第一波导基底19S1内部,第一填充层15S1覆盖第一光栅结构14S1的顶面和第一波导基底19S1的外表面。具体而言,在图101所示的实施方式的基础上,第一光栅结构14S1的顶面可以相较第一波导基底19S1的外表面内凹,这样,部分第一填充层15S1位于第一波导基底19S1形成的凹槽内。
相较图100所示的实施方式,图101所示的实施方式中,由于第一波导基底19S1和第一盖板15A之间的垂直距离变小,点胶结构154的尺寸也变小,因此,本实施方式可以使用较少量的粘胶来固定第一波导基底19S1和第一盖板15A。点胶结构154的小尺寸设计,有利于减少点胶结构对第一波导基底19S1的影响,可以理解的是,胶粘剂渗透到第一波导基底19S1影响第一波导基底19S1的折射率。
图99至图101所示的实施方式中,示意性地表达了第一光栅结构14S1在第一波导基底19S1上的布置方式,及第一光栅结构14S1和第一填充层15S1之间的位置关系,并没有详细绘出第一光栅结构14S1中的微结构。图102和图103示意性地描述了第一光栅结构14S1中的微结构与第一填充层15S1之间的位置关系。
参阅图102,第一填充层15S1包括光栅接触面15S11,光栅接触面15S11为平面状。第一光栅结构14S1包括周期性排列的微结构14S11,光栅接触面15S11和第一光栅结构14S1之间具有周期性排列的狭缝14S12,周期性排列的狭缝14S12可以理解为第一光栅结构14S1的周期性排列的微结构14S11所形成的狭缝结构。微结构14S11和狭缝14S12的尺寸均是纳米级单位,用于形成衍射光栅架构。本方案允许光栅接触面15S11和第一光栅结构14S1的表面之间存在狭缝,本方案提供的第一填充层15S1的制作工艺的精度要求较低,易于制作。
参阅图103,第一光栅结构14S1包括周期性排列的微结构14S11。第一填充层15S1包括光栅接触面15S11,光栅接触面15S11具有与第一光栅结构的微结构14S11相同的结构形态,以使得第一填充层15S1和第一光栅结构14S1之间无气隙式地接触。第一填充层15S1的光栅接触面15S11和第一光栅结构14S1的微结构14S11的表面贴合,即部分第一填充层15S1填充在第一光栅结构14S1和周期性排列的微结构14S11所构成的狭缝中。本实施方式提供的光波导10A中,第一光栅结构14S1的外围没有任何气隙,第一光栅结构14S1通过与第一填充层15S1完全接触,实现与空气的完全隔离,这样可以提升第一光栅结构14S1的寿命。
图99-图103所示的实施方式均可以视为单层单面的光波导架构,可以理解为在波导基底的其中一个表面设置光栅结构和填充层,波导基底的另一个表面不设置光栅结构和填充层。在这几个实施方式的基础上,任一实施方式均可以扩展为单层双面的光波导架构,即光波导具有一层波导基底,波导基底的正面和反面均设置光栅结构和填充层。
图104所示的实施方式为在图99所示的实施方式的基础上构建的单层双面的光波导架构。参阅图104,第一波导基底19S1的顶面设第一光栅结构14S1和第一填充层15S1,第一填充层15S1和第一波导基底19S1共同包围第一光栅结构14S1,第一填充层15S1在第一波导基底19S1的顶面的一侧保护第一波导基底19S1和第一光栅结构14S1。第一波导基底19S1的底面设有第二光栅结构14S2和第二填充层15S2,第二填充层15S2和第一波导基底19S1共同包围第二光栅结构14S2,第二填充层15S2在第一波导基底19S1的底面的一侧保护第一波导基底19S1和第二光栅结构14S2。所述第二填充层的折射率和空气的折射率之间的差值小于等于0.2。本实施方式中,第一光栅结构14S1和第二光栅结构14S2可以为同样的光栅类型,也可以为不同的光栅类型,二者可以具有相同的折射率,也可以具有不同的折射率。第一填充层15S1和第二填充层15S2可以为相同的材料,也可以为不同的材料,二者的折射率可以相同也可以不同。
图105所示的实施方式为在图103所示的实施方式的基础上构建的单层双面的光波导架构。参阅图105,光波导10A还包括第二光栅结构14S2、第二填充层15S2和第二盖板15B。第一光栅结构14S1、第一填充层15S1和第一盖板15A位于第一波导基底19S1顶面的一侧。第二光栅结构14S2、第二填充层15S2和第二盖板15B位于第一波导基底19S1底面的一侧。所述第二光栅结构14S2和所述第一光栅结构14S1分布在所述第一波导基底19S1相对的两侧,所述第二填充层15S2和所述第一波导基底19S1层叠设置,且所 述第二填充层15S2和所述第一光波基底19S1共同封闭包围所述第二光栅结构14S2。所述第二填充层15S2的折射率和空气的折射率之间的差值小于等于0.2。所述第二盖板15B和所述第一波导基底19S1固定连接,所述第二填充层15S2层叠设置在所述第二盖板15B和所述第一波导基底19S1之间,所述第二填充层15S2和所述第二盖板15B贴合。
一种实施方式中,第二盖板15B和第一波导基底19S1之间通过点胶结构154固定连接。点胶结构的具体设置方向可以参考第一盖板15A和第一波导基底19S1之间的点胶结构154的设置,不再赘述。
一种实施方式中,本申请还提供一种双层单面的光波导架构,即,光波导具有两层波导基底,每层波导基底均为单面设置光栅结构。一种实施方式中,整体光波导可以只有一个盖板结构。一种实施方式中,整体光波导也可以不设盖板结构。
如图106A所示的实施方式,在图103所示的实施方式的基础上,光波导10A还包括第二波导基底19S2、第三填充层15S3和第三光栅结构14S3。第一波导基底19S1和第二波导基底19S2层叠设置,第二波导基底19S2位于第一波导基底19S1背离第一盖板15A的一侧,第三光栅结构14S3形成在第二波导基底19S2的表面,且,第三光栅结构14S3位于第二波导基底19S2朝向第一波导基底19S1的一侧。第三填充层设置在第一波导基底19S1和第二波导基底19S2之间,第三填充层15S3和第二波导基底19S2共同包围第三光栅结构14S3。第三填充层15S3用于保护第三光栅结构14S3。第三填充层15S3的顶侧与第一波导基底19S1的底面贴合,第三填充层15S3的底侧与第二波导基底19S2的顶面贴合,因此,第三填充层15S3能够同时覆盖第一波导基底19S1的底面和第二波导基底19S2的顶面,能够实现对第一波导基底19S1和第二波导基底19S2的保护。所述第三填充层15S3的折射率和空气的折射率之间的差值小于等于0.2。
一种实施方式中,如图106A所示,第二波导基底19S2和第一波导基底19S1之间也可以通过点胶结构154固定连接。
如图106B所示的实施方式,光波导10A包括第一波导基底19S1和第二波导基底19S2,第一波导基底19S1的底面设有第一光栅结构14S1,第二波导基底19S2的顶面具有第三光栅结构14S3,第一波导基底19S1和第二波导基底19S2层叠设置,且第一光栅结构14S1和第三光栅结构14S3相对设置,即第一波导基底19S1的底面朝向第二波导基底19S2的顶面。本实施方式中,第一波导基底19S1和第二波导基底19S2之间通过填充层来保护第一光栅结构14S1和第三光栅结构14S3,如图106B所示,第一波导基底19S1和第二波导基底19S2之间的填充层为第一填充层15S1,第一填充层15S1能够同时覆盖第一波导基底19S1的底面、第一光栅结构14S1、第二波导基底19S2的顶面和第三光栅结构14S3。即,第一填充层15S1与第二波导基底19S2共同构成用于包围第三光栅结构15S3的包围构架。第一波导基底19S1和第二波导基底19S2之间通过点胶结构154固定连接,点胶结构154位于第一填充层15S1的外围。本方案提供的光波导10A中的第一填充层15S1的物理属性与图99所示的光波导中的第一填充层的物理属性可以相同。本实施方式提供的光波导10A中第一波导基底19S1的顶面和第二波导基底19S2的底面可以作为光波导的表层,不需要再设置其它的盖板结构,有利于光波导轻薄化的设计。
一种实施方式中,本申请还提供一种双层光栅架构的光波导,但是这种双层光栅架构的光波导只具有一个光导基底,其中一层光栅形成在波导基底上,另一层光栅形成在波导填充结构上,波导填充结构一方面可以承载光栅进行光线的全反射传播,另一方面可以保护波导基底上的光栅层。参阅图106C,一种实施方式中,光波导10A包括第一波导基底19S1,第一光栅结构14S1形成在第一波导基底19S1的顶面一侧,在第一波导基底19S1的顶面一侧设置波导填充结构19S3,波导填充结构19S3可以包裹第一光栅结构14S1且覆盖第一波导基底19S1的顶面。波导填充结构19S3的边缘相较第一波导基底19S1内缩,以在第一波导基底19S1的边缘预留位置用于点胶。波导填充结构19S3为高折射率材料,能够实现光线在其中进行全反射传播。波导填充结构19S3和第一波导基底19S1的折射率可以不同。波导填充结构19S3和第一波导基底19S1的折射率差可以在0-0.5之间。本方案限制了波导填充结构和第一波导基底之间的折射率差的范围,通过此范围的约束,使得各层光栅结构均能够执行衍射效率,使得波导填充结构和第一波导基底均具有全反射传播光线的功能。
波导填充结构19S3还用于形成第三光栅结构14S3,第三光栅结构14S3可以通过压印工艺形成在波导填充结构19S3背离第一波导基底19S1的一侧。光波导10A还包括第一填充层15S1,第一填充层15S1覆盖波导填充结构19S3且包覆第三光栅结构14S3。所述第一填充层15S1和所述波导填充结构19S3共同形成封闭的包围架构,所述第三光栅结构14S3位于所述包围架构内,以使所述第三光栅结构14S3与外界空气隔离,所述第一填充层15S1的折射率和空气的折射率之间的差值小于等于0.2。第一盖板15A形成在第一填充层15S1背离波导填充结构19S3的一侧,第一盖板15A和第一波导基底19S1之间通过点胶结构 154固定连接。图106C所示的实施方式,借助波导填充结构19S3构建了一层光栅结构。其它实施方式中,也可以借助波导填充结构19S3构建多层(两层或两层以上)光栅结构。本方案借助波导填充结构构建了一层光栅结构。其它实施方式中,也可以借助波导填充结构构建多层(两层或两层以上)光栅结构。本方案提供一种单层波导基底的基础上,结合波导填充结构所构建的多层架构,利用波导填充结构和第一填充层实现对各层光栅结构的保护,最外层的第一填充层与盖板合,还具有支撑和保护盖板的作用。
一种实施方式中,本申请还提供一种多层单面的光波导架构,即,光波导具有三层或三层以上的波导基底,每层波导基底均为单面设置光栅结构,整体光波导只有一个盖板结构。如图107所示的实施方式中,在图103所示的实施方式的基础上,所述光波导10A还包括至少两个第二波导基底19S2(图107所示的实施方式中,以两个第二波导基底19S2为例进行描述),各所述第二波导基底19S2上均设有第三光栅结构14S3,至少两个所述第二波导基底19S2层叠设置在所述第一波导基底19S1背离所述第一盖板15A的一侧,所述第二波导基底19S2和所述第一波导基底19S1之间,以及相邻的所述第二波导基底19S2之间均设有第三填充层15S3,所述第三填充层15S3和所述第二波导基底19S2共同包围所述第三光栅结构14S3,所述第三填充层15S3的折射率和空气的折射率之间的差值小于等于0.2。
在图106A和图107所示的实施方式的基础上,本申请还可以提供一种多层双面的光波导架构,即图106A和图107所示的实施方式中的第一波导基底19S1的顶面和底面均可以设置光栅结构,类似地,第二波导基底19S2的顶面和底面也为均可以设置光栅结构的状态。参阅图108,一种实施方式中,光波导10A包括层叠设置的第一波导基底19S1和第二波导基底19S2。第一波导基底19S1的顶面设有第一光栅结构14S1,第一波导基底19S1的底面设有第二光栅结构14S2。第二波导基底19S2的顶面设有第三光栅结构14S3,第二波导基底19S2的底面设有第四光栅结构14S4。第一盖板15A位于第一波导基底19S1顶面的一侧,第一盖板15A和第一波导基底19S1之间设有第一填充层15S1。第一填充层15S1和第一波导基底19S1共同包围第一光栅结构14S1。第二波导基底19S2和第一波导基底19S1之间设有第二填充层15S2,第二填充层15S2和第一波导基底19S1共同包围第二光栅结构14S2,第二填充层15S2和第二波导基底19S2共同包围第三光栅结构14S3。第二波导基底19S2背离第一波导基底19S1的一侧设有第三填充层15S3,第三填充层15S3和第二波导基底19S2共同包围第四光栅结构14S4。
图108所示的实施方式中,可以在第三填充层15S3的底部设置一个第二盖板。
图108所示的实施方式中,第一填充层15S1、第二填充层15S2和第三填充层15S3均可以满足:其折射率和空气的折射率之间差值小于等于0.2。一种具体的实施方式中,第一填充层15S1、第二填充层15S2和第三填充层15S3均可以满足:其折射率和空气的折射率之间差值小于等于0.1,通过控制各填充层的折射率更接近空气,可以提升光波导的透光性。
图99-图108示意性地举例说明本申请提供的几种具体的实施方式,本申请不限于上述具体实施方式。
针对上述实施方式中的第一填充层、第二填充层和第三填充层,还可以具有如下的限定,接下来,以第一填充层为例进行描述,第二填充层和第三填充层可以与第一填充层为相同的材料或属性。
一种实施方式中,第一填充层的透光性大于等于80%。本方案限定第一填充层的透光性,可以保证光波导的透光性。
一种实施方式中,第一填充层的厚度小于等于1000um。本方案通过限定第一填充层的厚度保证光波导的折射率、透光性,以及使得光波导具有轻量化优势。
一种实施方式中,第一填充层的厚度介于1um至1000um之间。为了保证光波导的轻薄化,可以将第一填充层的厚度控制在100um以内。
一种实施方式中,第一填充层的材料包括气凝胶材料、树脂材料、无机材料、有机材料中的任意一种或多种的组合。气凝胶材料可以是二氧化硅、碳化物、氧化物、非氧化物、有机聚合物等。
二氧化硅折射率1.5左右,本身并不是理想的低折材料,在二氧化硅材料中引入孔隙构成二氧化硅气凝胶。让空气分担一部分折射率,例如二氧化硅50%的孔隙率,那么复合折射率就是1.5*50%+1*50%=1.25。二氧化硅气凝胶可以作为第一填充层的材料。二氧化硅气凝胶是由纳米二氧化硅粒子相互连接构成的一种具有纳米级孔径的三维多孔网络结构的固态材料,这些孔洞中充满了空气,通过调节二氧化硅气凝胶的孔隙来调节折射率,目前可以做到气凝胶90%以上的体积都是空气,纯净的二氧化硅气凝胶透明无色,折射率最低可达到1.007,接近空气折射率。且由于大部分体积都是空气,因此密度也非常低,同时还具有良好的透光性和硬度,目前可达到95%的光透过性,亦可承受自身重量几千倍的压力。
一种实施方式中,第一填充层具有弹性模量,可以理解为,第一填充层在第一盖板和第一波导基底之间,通过其自身的弹性模量,可以保证第一填充层和第一盖板之间的紧密贴合,以及第一填充层和第一波 导基底之间的紧密贴合。
本申请具体实施方式中的填充层,例如第一填充层,的折射率接近空气的折射率,其折射率和空气的折射率之间差值小于等于0.2。填充层与空气的折射率相差越大,FOV视场范围缩小越多,光栅调制效果降低越多,因此本申请提供的填充层在保证各方面的物理特性接近空气的状态下,能够保证了光学效果的同时还起到了缓冲和排除水氧的作用。
参阅图109,一种实施方式中,本申请提供一种光波导的制作方法,包括如下步骤。
步骤ST11,提供第一盖板15A,在所述第一盖板15A上涂设第一填充材料15S10。具体而言,可以通过旋涂或喷涂原料的方式,将第一填充材料15S10涂满第一盖板15A的表面。
步骤ST12,去除第一盖板15A边缘位置的部分第一填充材料15S10,保留的部分第一填充材料15S10构成第一填充层15S1。
步骤ST13,固化处理,使得第一填充层15S1在第一盖板15A上固化成型,以在第一盖板15A上形成预设形态的第一填充层15S1,预设形态可以理解为,第一填充层15S1具有预设的厚度,预设的面积等参数。
步骤ST14,提供第一波导基底19S1,所述第一波导基底19S1上设有第一光栅结构14S1,对位所述第一盖板15A和所述第一波导基底19S1,使得所述第一填充层15S1和所述第一波导基底19S1结合且共同封闭包围所述第一光栅结构14S1。
步骤ST15,固定所述第一盖板15A和所述第一波导基底19S1,以使所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2。
具体而言,通过点胶结构154固定连接第一盖板15A和第一波导基底19S1。具体而言,在固定第一盖板15A和第一波导基底19S1的过程中,施加压力至第一盖板15A上,使得第一填充层15S1受压力产生弹性形变,由于第一填充层15S1具有弹性模量,储存弹性势能,固定第一盖板15A和第一波导基底19S1后,在第一填充层15S1的弹性势能的作用下,使得第一填充层15S1能够与第一波导基底19S1和第一光栅结构14S1紧密贴合。
参阅图110,一种实施方式中,本申请提供一种光波导的制作方法,包括如下步骤。
步骤ST21,提供硬质母模19S10,所述硬质母模19S10上具有光栅模结构14S10。硬质母模19S10和光栅模结构14S10的选择和制作过程,需要考虑本申请要制作的光波导中的波导基底和光栅结构的具体的结构形态和尺寸参数。例如,硬质母模19S10和光栅模结构14S10构成的结构和尺寸与后续制作的光波导的第一波导基底和第一光栅结构的结构和尺寸均相同,也可以在保证基本结构形态的基础上,具有较小范围的公差。
步骤ST22,对所述硬质母模19S10的表面及所述光栅模结构14S10的表面进行疏水处理,形成疏水膜层19S11。
步骤ST23,在所述硬质母模19S10上涂设第一填充材料,具体为疏水膜层19S11涂设第一填充材料,在以形成第一填充层15S1。具体而言,疏水膜层19S11为承载第一填充材料的基底。可以先将第一填充材料涂满疏水膜层19S11的表面,再将边缘的部分去除,便形成第一填充层15S1。
步骤ST24,将第一盖板15A贴设在所述第一填充层15S1上,第一盖板15A和第一填充层15S1结合为一体。
步骤ST25,脱模,使得所述第一盖板15A和所述第一填充层15S1与所述硬质母模19S11脱离。具体而言,从步骤ST24至步骤ST25的过程中,由于疏水膜层19S11的存在,使得第一填充层15S1能够与硬质母模19S11分离,即构成了第一盖板15A和第一填充层15S1互连为一体的结构。
步骤ST26,提供第一波导基底19S1,所述第一波导基底19S1上设有第一光栅结构14S1。对位所述第一盖板15A和所述第一波导基底19S1,使得所述第一填充层15S1和所述第一波导基底19S1结合且共同封闭包围所述第一光栅结构14S1。
步骤ST27,固定所述第一盖板15A和所述第一波导基底19S1,以使所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2。
具体而言,通过点胶结构154固定连接第一盖板15A和第一波导基底19S1。具体而言,在固定第一 盖板15A和第一波导基底19S1的过程中,施加压力至第一盖板15A上,使得第一填充层15S1受压力产生弹性形变,由于第一填充层15S1具有弹性模量,储存弹性势能,固定第一盖板15A和第一波导基底19S1后,在第一填充层15S1的弹性势能的作用下,使得第一填充层15S1能够与第一波导基底19S1和第一光栅结构14S1紧密贴合。本实施方式中,第一填充层15S1具有与所述第一光栅结构相同的周期性排列的微结构,所述第一填充层的所述光栅接触面和所述第一光栅结构的微结构的表面贴合。
参阅图111,一种实施方式中,本申请提供一种光波导的制作方法,包括如下步骤。
提供一种光波导中间结构,所述光波导中间结构包括第一波导基底19S1、第一光栅结构14S1和第一盖板15A,所述第一光栅结构14S1形成在所述第一波导基底19S1的表面,所述第一盖板15A和所述第一波导基底19S1层叠设置且固定连接,所述第一盖板15A和所述第一波导基底19S1之间及所述第一盖板15A和所述第一光栅结构14S1之间形成间隙15G。
步骤ST31,在第一盖板15A上打孔开成注入孔15H,具体而言,注入孔15H可以设置在第一盖板15A的边缘位置,注入孔15H避开第一光栅结构14S1所对应的第一盖板15A上的区域。即,第一光栅结构14S1在第一盖板15A上的垂直投影和注入孔15H无交集,且二者相隔离。这样,注入孔15H的位置不会影响第一光栅结构14S1的衍射效率。
一种实施方式中,注入孔15H的数量为一个,设在第一盖板15A的边缘位置。其它实施方式中,注入孔15H的数量为两个,两个注入孔15H可以分别设置在第一盖板15A相对的边缘位置。
一种实施方式中,第一盖板15A和第一波导基底19S1之间通过点胶结构154固定连接,注入孔15H的位置邻近点胶结构154设置。点胶结构154的附近的位置设置注入孔15H能够使得注入孔15H对光波导的光学性能的影响较小,或不影响光波导的光学性能。
步骤ST32,通过注入孔15H,将填充材料注入间隙15G中,形成第一填充层15S1,所述第一填充层15S1和所述第一波导基底19S1共同形成封闭的包围架构,所述第一光栅结构14S1位于所述包围架构内,以使所述第一光栅结构14S1与外界空气隔离,所述第一填充层15S1的折射率和空气的折射率之间的差值小于等于0.2。
具体而言,在将填充材料注入间隙的过程中,可以通过控制注入的填充材料的重量或体积来判断是否将间隙15G填满。当注入孔的数量为两个时,可以使用其中一个注入孔注入填充材料,当将间隙15G填满的状态下,填充材料会从另一个注入孔冒出来,因此,两个注入孔的设计方案不但可以判断填充材料填充的状态,也可以在注入填充材料的过程中,将间隙15G的气体排出,有利于保证填充材料的折射率和透光性。
注入完成第一填充层后,将第一盖板15A外表面的残留的填充材料清除,然后进行固化处理。
参阅图112,一种实施方式中,本申请提供一种光波导的制作方法,包括如下步骤。
步骤ST41,提供第一波导基底19S1,所述第一波导基底19S1上设有第一光栅结构14S1。
步骤ST42,通过旋涂或喷涂的方式将填充材料直接涂在第一波导基底19S1和第一光栅结构14S1的表面,形成填充层。具体而言,填充层可以完全覆盖在第一波导基底19S1和第一光栅结构14S1的表面,再将第一波导基底19S1边缘位置的填充材料去除,便形成了第一填充层15S1。
步骤ST43,在第一填充层15S1的外围,且在第一波导基底19S1上设置点胶结构154。一种实施方式中,点胶结构154背离第一波导基底19S1的面可以与第一填充层15S1背离第一波导基底19S1的表面共面。一种实施方式中,或者点胶结构154背离第一波导基底19S1的面可以低于第一填充层15S1背离第一波导基底19S1的表面,即第一填充层15S1突出于点胶结构154。
步骤ST44,提供第一盖板15A,对位第一盖板15A和点胶结构154,将第一盖板15A粘贴在点胶结构154上,以使得第一盖板15A和第一波导基底19S1固定连接。一种实施方式中,在步骤ST43完成后,点胶结构154背离第一波导基底19S1的面可以低于第一填充层15S1背离第一波导基底19S1的表面,在将第一盖板15A和第一波导基底19S1固定连接的过程中,第一盖板15A施加压力至第一填充层15S1,使得第一填充层15S1受压力产生弹性形变,由于第一填充层15S1具有弹性模量,储存弹性势能,固定第一盖板15A和第一波导基底19S1后,在第一填充层15S1的弹性势能的作用下,使得第一填充层15S1能够与第一盖板15A紧密贴合。
方案九:光波导的轻量化基底
如图113所示,一种实施例中,光波导10A可以包括保护层198、光栅结构14、波导层19a和集成镜片199。光栅结构14位于波导层19a表面。保护层198与集成镜片199分别位于波导层19a的两侧。光栅结构14用于衍射偏转光线。波导层19a用于全反射光线。保护层198与集成镜片199用于保护光栅结构14与波导层19a。
波导层19a的材料是高折射率玻璃材料,例如,波导层19a的折射率大于等于1.6,以使耦入其中的光线可以在其中进行全反射传播。但因考虑量产时高折射率玻璃的晶圆较大(8寸或12寸),所以在加工过程中无法将波导层19a做的太薄。又因玻璃材料的折射率越高其密度也会越大,所以使用高折射率玻璃材料制成的波导层19a的重量较大。
图113示意了一种光波导的设计方案,由图113所示的光波导10A构成近眼显示设备时,单个镜片(左镜片或右镜片)的整体(包括保护层198、光栅结构14、波导层19a和集成镜片199)重量会超过20克。因此,该光波导10A制成的近眼显示设备存在重量和厚度较大的问题,不便于长时间佩戴。因此如何降低单侧近眼显示设备的重量和厚度是光波导领域研究的热点之一,而光波导则的轻量化成为业内研发的方向。
一种实施方式中,本申请通过将波导基底设计为复合材料,以实现光波导的轻量化,解决近眼显示设备重量和厚度较大的问题。
如图114所示,一种实施例中,光波导10A可以包括层叠设置的波导基底19和光栅层197,光栅结构14可以形成于光栅层197上。波导基底19用于光线的传输,光栅结构14用于衍射偏转光线。波导基底19可以包括第一基材层195和第二基材层196。第一基材层195的折射率低于第二基材层196的折射率,第二基材层196的折射率和第一基材层195的折射率的差值大于等于0.1,第二基材层196的厚度介于50微米至300微米之间。光栅结构14位于第二基材层196背离第一基材层195的一侧。本方案通过将波导基底19设计为由第一基材层195和第二基材层196层叠构成的复合材料,通过对第二基材层196的厚度的约束,以及对第一基材层195和第二基材层196的折射率差的约束,能够实现光波导10A的轻量化。
对比图113和图114所示方案,图113所示方案中波导层19a由高折射率玻璃材料制成,存在重量较重(由图113所示方案制成的近眼显示设备的单眼镜片重量超过20克)的问题。而图114所示的光波导10A的波导基底19包括第一基材层195和第二基材层196,其中,第一基材层195由低折射率材料制成,而第二基材层196为通过制作工艺形成于第一基材层195上膜结构,这使得图114所示光波导10A的波导基底19的重量可以较小(由图114所示方案制成的近眼显示设备的单眼镜片重量可以小于20克)。也即,相比本实施方案与图113所示方案,本实施例中的光波导10A的重量更小,更能实现光波导的轻量化。
具体而言,第一基材层195由低折射率材料(例如低折玻璃)制成,使得第一基材层195具有密度小、重量轻和厚度小的特点。第一基材层195不具备全反射光线的性能,所以第一基材层可以做得较薄、较轻。第一基材层195作为第二基材层196承载层,形成在第一基材层195上的第二基材层196的厚度可以介于50微米至300微米之间。第二基材层196具有折射率高的特点,能够满足光线的全反射的要求,从而能够传播光信号。第一基材层195与第二基材层196结合成一体结构时,波导基底19的总厚度可以小于0.35mm。因此,本申请提供的实施方式不仅能够降低波导基底19的重量、减小波导基底19的厚度,还能够降低光波导10A的重量、减小光波导10A的厚度。从而能够在满足光线能够在其中全反射传播(光学性能)的基础上,实现光波导10A的轻量化。
第一基材层195的材料可以为玻璃,第一基材层195的折射率可以小于或等于1.55。第二基材层196的材料可以为TiO2、氮化硅、氮化镓、高折树脂材料中的一种或至少两种的组合。第二基材层196的折射率可以大于或等于1.65。本方案约束第二基材层的折射率范围,使得第二基材层可以满足光的全反射传播的功能。
如图114所示,第一基材层195用于在制作第二基材层196过程中承载形成第二基材层196的材料,第二基材层196通过制作工艺和第一基材层195结合为一体成型的结构。制作工艺可以是气相沉积、物理沉积、旋涂、刮涂、喷涂、注塑、电镀等,也可以是其他可以直接形成的工艺方法。第二基材层196与第一基材层195结合为一体成型的结构,可以是指制作第二基材层196可以与第一基材层195直接连接为一体,二者之间无其它层结构,即第二基材层196的过程中,可以直接在第一基材层195的表面通过上述制作工艺设置第二基材层196的材料。其它实施方式中,第二基材层196与第一基材层195结合为一体成型的结构,也可以是指第一基材层195与第二基材层196之间还有其他层结构,例如在制作第二基材层196之前可以在第一基材层195表面制作具有光栅结构的光栅层,例如压印胶,再在光栅层上通过上述制作工 艺设置第二基材层196的材料。
图114所示的实施方式中,光栅层197形成于第二基材层196背离第一基材层195的表面。可以通过旋涂或沉积工艺将光栅层197设置在第二基材层196的表面,光栅层197可以为但不限于压印胶材料。光栅层197的折射率可以与第二基材层196的折射率相同。光栅层197的折射率也可以与第二基材层196的折射率不同。本申请可以通过调制光栅层197的折射率来调制光波导10A的衍射效率。光栅结构14可以通过压印工艺形成于光栅层197上。一种实施方式中,光栅层197可以由相同于第二基材层196材料的压印胶制成,也可以由其他高折射率材料的压印胶制成。光栅结构14可以是倾斜光栅、闪耀光栅,也可以是其他光栅,本实施例并不限定光栅结构14具体结构和类型,本领域的技术人员能够根据实际对其进行设计。
图114所示的实施方式中,第一基材层195不但用于在制作光波导10A的过程中承载第二基材层196,第一基材层195还用做保护第二基材层196和光栅结构免受外界粉尘、空气或水气的侵蚀,保证光波导的衍射效率。因此,本申请提供的光波导10A,在第一基材层195背离第二基材层196的一侧无需要再设置保护层,有利于光波导10A的轻量化的发展。
一种实施例中,光栅结构可以通过刻蚀工艺形成于波导基底和第二基材层上。具体的,如图115所示,与图114所示的光波导10A不同的是,光栅结构14通过刻蚀工艺形成于第二基材层196背离第一基材层195的一侧。通过刻蚀工艺形成光栅结构14可以保证波导基底19与光栅结构14的结合为一体,提升光栅结构14的结构稳定性和可靠性,保证光波导10A的衍射效率,提升光波导10A的光学性能。
一种实施方式中,光栅结构也可以形成在第一基材层和第二基材层之间。或者,光栅结构可以分布在第二基材层的两侧,即在第二基材层和第一基材层之间及在第二基材层背离第一基材层的一侧均可以设置光栅结构。
参阅图116,一种实施方式中,部分光栅结构14可以通过刻蚀工艺形成于波导基底19的内部。图116所示的实施方式与图114所示的光波导10A的区别在于:通过刻蚀工艺在第一基材层195的表面形成光栅结构14。第二基材层196通过制作工艺形成于第一基材层195的表面,且第二基材层196与第一基材层195上的光栅结构14结合。具体而言,先在第一基材层195的表面通过刻蚀工艺形成多个沟槽状的微结构14a,再在第一基材层195上通过制作工艺设置第二基材层196,例如,沉积或涂覆的方式将第二基材层196的材料设置在第一基材层195上,这个过程中,第二基材层196的材料填充在多个沟槽状的微结构14a中,便使得第二基材层196和多个沟槽状的微结构14a结合形成光栅结构14。位于第一基材层195上的光栅结构14与位于光栅层197上光栅结构14布置于第二基材层196的两侧。
其它实施方式中,在第一基材层195的表面制作好多个沟槽状的微结构14a,也可以先填充高折射率的材料形成光栅结构,再制作第二基材层196,也就是说,沟槽状的微结构14a中的高折射率的材料可以和第二基材层196的材料可以不同,可以用两道工序制作形成。
图116所示的实施方式中,分布在第二基材层196两侧的光栅结构14分别通过压印工艺和刻蚀工艺形成,具体而言,在第一基材层和第二基材层之间的光栅结构使用刻蚀工艺形成,而形成于第二基材层196背离第一基材层195一侧的光栅结构通过设置光栅层197,在光栅层197上采用在压印工艺制作。在其他实施例中,可以在第一基材层195和第二基材层196之间形成光栅层197,采用压印技术在此光栅层上制作光栅结构14,形成于第二基材层196背离第一基材层195一侧的光栅结构14通过刻蚀工艺形成。
图116所示的实施方式提供的光波导10A为构成单层波导基底19双面光栅结构14的架构,这不仅有利于提升光波导10A的衍射效率以及减轻光波导10A的重量,还能对光栅结构14设计更多的变量,以提升光波导10A的成像均匀性。
此外,在其他实施例中,光波导10A可以仅具有第一基材层195和第二基材层196之间的光栅结构,在第二基材层196背离第一基材层195的一侧不设置光栅结构。本实施例对光栅结构的数量、制作工艺和具体结构不做具体的限定,本领域的技术人员能够根据实际对光栅结构14进行具体设计。
参阅图117,图117所示的实施方式与图114所示的光波导10A的区别在于:第一基材层195和第二基材层196之间的光栅结构是通过在光栅层197上采用压印技术形成的。具体而言,在第一基材层195的表面设有光栅层197,光栅层197的表面压印有光栅结构14。第二基材层196通过制作工艺直接形成于光栅层197背离第一基材层195的表面。再在第二基材层196的表面设置另一层光栅层197,光栅层197上形成光栅结构14。图117示意性地表达了第二基材层196两侧的光栅结构14均通过压印工艺形成在光栅层197上。本方案并不限定光栅层197的材料,两个光栅层197可以由相同材料的压印胶制成,也可以由不同材料的压印胶制成。本实施例对光栅层197的材料不做具体的限定,本领域的技术人员能够根据实际 对光栅结构14进行具体设计。
图114、图116和图117所示的实施方式中,光波导10A均包括光栅层197,一种实施方式中,光栅层197也可以由多层材料构成,即光栅层可以为复合材料。一种实施方式中,光栅层197的材料可以为体全息材料,在光栅层197上全息曝光形成光栅结构14,形成的光栅结构14可以是体全息光栅。光栅层197上的光栅结构也可以为其它类型的光栅结构,或者复合光栅(包括多种光栅类型或多种材料、多种不同的矢量方向或周期等等)。
前述各实施方式提供的光波导10A可以内置在近眼显示设备的镜片中,光波导10A的两侧均与镜片的层结构相贴合,这样,第二基材层196背离第一基材层195的一侧不需要设置其它的保护层,可以借助镜片的材料将光栅结构和第二基材层196包覆,以实现对光栅结构和第二基材层196的保护。
前述各实施方式提供的光波导10A也可以位于镜片的表层,例如,第一基材层195位于最外层,第二基材层196背离第一基材层195的一侧和镜片的表面贴合,这样,第二基材层196和光栅结构设置在第一基材层195和镜片之间,通过第一基材层和镜片共同保护光栅结构和第二基材层196。
前述各实施方式提供的光波导10A应用在镜片中,由于第二基材层196背离第一基材层195的一侧不需要设置其它的保护层,与镜片结合时能够实现镜片的轻量化,提升近眼显示设备佩戴的舒适性。
一种实施例中,光波导还可以包括填充层和保护层,通过填充层和保护层覆盖在第二基材层背离第一基材层的一侧,填充层和保护层用于保护第二基材层和光栅结构。
如图118A所示,一种实施方式中,波导基底19包括层叠设置的第一基材层195和第二基材层196,第一基材层195和第二基材层196的具体的设计与前述各实施方式可以相同,不再赘述。第二基材层196背离第一基材层195的一侧具有光栅结构14,光栅结构14是通过刻蚀工艺形成在第二基材层196上。具体而言,在第二基材层196上刻蚀形成周期性排列的具有狭缝的微结构14a。光波导10A还包括填充层14b。具体而言,在第二基材层196背离第一基材层195的一侧层叠填充层14b。填充层14b覆盖第二基材层196和微结构14a并填充微结构14a形成的狭缝。在填充层14b背离第二基材层的一侧设保护层198。保护层198可以通过胶粘的方式形成于第二基材层196的一侧。填充层14b不仅可以用于保护第二基材层196和光栅结构14,还可以用于避免第二基材层196和光栅结构14与胶接触,若第二基材层196和光栅结构14和胶接触,胶水可能会渗入第二基材层196和光栅结构14中,影响第二基材层196和光栅结构14的折射率,影响光波导的衍射效率,因此,本方案能够保证光波导的衍射效率。
一种实施方式中,保护层198的折射率可以为小于等于1.55。示意性的,保护层198的材料可以与第一基材层195的材料一样,也可以由其他折射率较低的玻璃材料制成。保护层198可以保护波导基底19表层的光栅结构14不受外界环境影响。本实施例中,第一基材层195与保护层198可以保护位于两者中间的第二基材层196与光栅结构14,使得第二基材层196和光栅结构14免受外界粉尘、空气后水气的侵蚀,保证光波导10A的衍射效率。
一种实施例中,可以基于图114、图116和图117的方案进行设计改进,增设保护层198和填充层14b,以保护第二基材层196与光栅结构14不被外界因素损伤。
图118B所示的实施方式是基于图114所示方案,增设保护层198和填充层14b的架构。如图118B所示,第二基材层196背离第一基材层195的表面设置光栅层197,光栅层197上具有光栅结构14,填充层14b位于第二基材层196背离第一基材层195的一侧,且和光栅层197层叠设置。填充层14b覆盖光栅层197和光栅结构14。填充层14b背离第二基材层196的一侧设有保护层198。
图118A所示的实施方式和图118B所示的实施方式中,与填充层14b接触的部分光栅结构14可以为闪耀光栅或倾斜光栅等,光栅结构14具有微结构14a,填充层14b的设置可以填充微结构14a之间的狭缝,以实现对光栅结构14的全面保护。
其它实施方式中,也可以不在光栅结构14和保护层198之间形成填充层14b。可以直接使用保护层198遮盖光栅层197。
参阅图118C,一种实施方式中,形成在第二基材层196背离第一基材层195的表面的光栅层197为体全息材料,光栅结构14通过全息曝光的方式形成。本方案中,光栅结构14的表面为平面状,光栅结构14不具有狭缝结构,因此本方案不需要设置填充层。在光栅层197背离第二基材层196的一侧设保护层198,直接通过保护层198对光栅层197和光栅结构14进行保护。
本申请通过第一基材层195与保护层198可以保护位于两者中间的第二基材层196与光栅结构14,使得第二基材层196和光栅结构14免受外界粉尘、空气后水气的侵蚀,保证光波导10A的衍射效率。
图118A、图118B和图118C是基于单层波导基底具有单面光栅结构的光波导的方案的基础上设置填 充层和保护层的方案。其它实施方式中,也可以基于单层波导基底具有双面光栅结构的光波导的方案的基础上设置填充层和保护层。
一种实施方式中,参阅图119,光波导10A包括依次层叠设置的第一基材层195、第二基材层196、光栅层197、填充层14b和保护层198。第一基材层195的表面具有光栅结构14,此部分光栅结构14通过刻蚀工艺形成。第二基材层196的表面具有光栅层197,光栅层197上具有光栅结构14,此部分光栅结构14通过压印工艺形成。光栅层197背离第二基材层196的一侧具有填充层14b,填充层14b背离光栅层197的一侧具有保护层198。本实施例中,第一基材层195与保护层198可以保护第二基材层196与光栅结构14,使得第二基材层196和光栅结构14免受外界粉尘、空气后水气的侵蚀,保证光波导10A的衍射效率。
一种实施方式中,参阅图120,光波导10A包括依次层叠设置的第一基材层195、光栅层197、第二基材层196、填充层14b和保护层198。第一基材层195的表面具有光栅层197,光栅层197上具有光栅结构14,此部分光栅结构14通过压印工艺形成。第二基材层196形成在光栅层197的表面。第二基材层196的表面具有光栅结构14,此部分光栅结构14通过刻蚀工艺形成。填充层14b覆盖在第二基材层196的表面且填充光栅结构14。填充层14b背离第二基材层196的一侧具有保护层198。本实施例中,第一基材层195与保护层198可以保护位于两者之间的第二基材层196与光栅结构14,使得第二基材层196和光栅结构14免受外界粉尘、空气后水气的侵蚀,保证光波导10A的衍射效率。
图114至图120所示的光波导10A可以通过同一波导基底19传输不同波长范围的光,例如红绿蓝三种颜色的光信号来实现红绿蓝三种颜色的全彩显示的,这样的光波导结构可以称为单层光波导。
其它实施方式中,光波导还可以通过多层波导基底层叠的方式,将不同波长范围的光,例如红绿蓝三种颜色光信号,分开走不同的通道单独传输,或者将不同波长范围的光,例如红绿蓝三种颜色光信号,分为两组传输,例如可以将红绿两种颜色光信号分为一组传输,绿蓝两种颜色光信号分为一组传输。
一种实施方式中,如图121所示,光波导10A的波导基底19可以包括第一波导基底19S1和第二波导基底19S2,其中,第一波导基底19S1与第二波导基底19S2均包括第一基材层195和第二基材层196,且第二基材层196通过制作工艺形成在第一基材层195上,第一基材层195与第二基材层196结合为一体成型结构。在第一波导基底19S1和第二波导基底19S2中,第二基材层196背离第一基材层195的一侧刻蚀有光栅结构14。第一波导基底19S1、第二波导基底19S2与光栅结构之间具体的制作工艺和位置关系可以参见图114和图115所示的实施方式的相关内容,此处不再赘述。
如图121所示,第一波导基底19S1的第一基材层195位于第二波导基底19S2的第二基材层196背离第二波导基底19S2的第一基材层195的一侧,第一波导基底19S1的第一基材层195与第二波导基底19S2中的第二基材层196之间具有填充层14b,该填充层14b覆盖第二波导基底19S2上的光栅结构14,用于保护第二波导基底19S2中的光栅结构14和第二基材层196表面。保护层198位于第一波导基底19S1中的第二基材层196背离第一基材层195的一侧。保护层198与第一波导基底19S1的第二基材层196之间形成有填充层14b,该填充层14b覆盖第一波导基底19S1的光栅结构14,用于保护第一波导基底19S1中的光栅结构14和第二基材层196。
在本实施例中,波导基底19中的第一波导基底19S1和第二波导基底19S2可以将不同波长的光,例如红绿蓝三种颜色的光信号,成两组传输,这不仅能够提升光波导10A的光学利用率和光学性能,还能提升光波导10A的显示视场角、亮度均匀性和颜色均匀性。
可以理解的是,图114至图120中任意一种实施方式提供的光波导均可以构成双层光波导架构中的某一层。
一种实施例中,光波导还可以包括位于功能区和边缘区。具体的如图122和图123所示,其中,图122是本实施例中的一种光波导10A的结构示意图,图123是图122所示光波导10A在A-A处的剖视结构示意图。
如图122和图123所示,光波导10A包括功能区19D和边缘区19E。波导基底19和光栅结构14位于功能区19D内,其中,波导基底19可以包括第一基材层195和第二基材层196。光栅结构14和波导基底19可以是图114至图121所示实施例中任一实施例中的光栅结构14和波导基底19的结合,此处不再赘述。
如图122和图123所示,边缘区19E位于功能区19D的外周。波导基底19和光栅结构14用于光信号的传输和显示。功能区19D用于承载光栅结构14和波导基底19。在近眼显示设备的镜片中,功能区19D可以与人眼的瞳孔部分相对应,其尺寸可以小于镜片的整体尺寸。边缘区19E可以为位于瞳孔的外周的镜片部分。
如图123所示,边缘区19E内设有波导边缘主体19E1。波导边缘主体19E1可以由树脂材料制成,其折射率可以位于1.55至1.75之间。波导边缘主体19E1具透光性,外界光线通过光波导10A的波导边缘主体19E1可以进行入眼,从而扩大视野范围。
如图123所示,位于边缘区19E中的波导边缘主体19E1和位于功能区19D内的波导基底19的边缘结合。波导边缘主体19E1的密度可以小于第一基材层195的密度。示意性的,波导基底19与波导边缘主体19E1可以是一体成型,也可以是胶粘结合,或者其他可结合连接的方式。
如图123所示,波导边缘主体19E1近眼侧的边缘表面19E2为具备一定曲率的曲面,该曲面可以用于补偿因波导边缘主体19E1与波导基底19折射率不同而导致的视觉偏差,从而能够提升光波导10A的显示性能。
包括波导边缘主体19E1的功能区16的尺寸参数、材料和形状结构可以根据需要就行调节,以便更好地补偿因波导边缘主体19E1与波导基底19折射率不同而导致的视觉偏差,如图123和图124所示,在功能区19D与边缘区19E的边缘处,两者的厚度可以相等,也可以功能区19D的厚度小于边缘区19E的厚度。此外,边缘区19E的近眼侧表面的曲率也可以不相同。
本实施例中,边缘区19E密度小于第一基材层195的密度,所以位于波导基底19外侧的边缘区19E能够降低光波导10A的重量,实现光波导10A的轻量化。
另一种实施例中,光波导还可以包括包裹层。具体的,如图125和图126所示,其中,图125是本申请实施例中另一种光波导10A的结构示意图,其中图126是图125所示光波导10A在B-B处的剖视结构示意图。
如图125和图126所示,光波导10A可以包括光栅结构14、波导基底19和包裹层19G,其中,波导基底19可以包括第一基材层195和第二基材层196。光栅结构14与波导基底19可以被包裹层19G包裹。光栅结构14和波导基底19可以是图114至图121所示实施例中任一实施例中的光栅结构14和波导基底19的结合,此处不再赘述。在近眼显示设备的镜片中,光栅结构14和波导基底19可以与人眼瞳孔部分相对应,其尺寸小于镜片的整体尺寸,用于光信号的传输和显示。边缘区19E除了光栅结构14和波导基底19对应的区域外,包裹层19G中其他区域可以为位于瞳孔的外侧的镜片部分,用于承载光栅结构14和波导基底19。
示意性的,本申请实施例中,光栅结构14和波导基底19可以被包裹层19G全包裹,在其他实施例中,光栅结构14和波导基底19也可以被包裹层19G半包裹。
如图126所示,包裹层19G可以由树脂材料制成,其折射率可以位于1.55至1.75之间,且包裹层19G具有透光性能。包裹层19G包括第一表面19G1和第二表面19G2,其中。第一表面19G1是包裹层19G中近眼一侧的外表面,第二表面19G2是包裹层19G远离眼一侧外表面。
如图126所示,第一表面19G1可以为曲面,例如可以为具有不同曲率的凹面,或者可以是其他形状的光滑曲面。第一表面19G1可以通过3D打印、浇注或者其他可以实现的方式形成。第一表面19G1不仅可以补偿因波导基底19与包裹层19G之间折射率差异导致的视角偏差,还可以用于矫正不同的近视度数。
如图126所示,第二表面19G2可以为平面。在其他实施例中,包裹层19G远离眼一侧的第二表面19G2也可以为具有不同曲率的凸面,如图127所示。
示意性的,本实施例不对包裹层19G的外表面做具体的限定,只要包裹层19G的外表面可以矫正不同的近视度数即可,本领域的技术人可以根据实际需要对其进行设计。
本实施例中,包裹层19G不仅可以进一步降低光波导10A的重量,还可以通过外表面的曲率矫正近视度数,使得光波导10A可以集成了近视镜的作用,从而可以适应于近视人群。
方案十:纳米压印方法制作双层光波导
图128是本申请一种实施方式提供的光波导10A的示意图。一种可能的实施方式中,光波导10A包括基底层19S、第一光栅层19A、第二光栅层19B和增粘层114。第一光栅层19A与所述基底层19S层叠设置。第二光栅层19B层叠设置在所述第一光栅层19A背离所述基底层19S的一侧,在所述第一光栅层19A和所述第二光栅层19B之间具有增粘层114,通过增粘层114使得第一光栅层19A和第二光栅层19B稳固结合,在光波导的制作过程中,具有能够保证第一光栅层19A和第二光栅层19B连接可靠性利于脱膜的好处,在光波导10A的具体应用过程中,也有利于保证第一光栅层19A和第二光栅层19B结合状态的稳定性。
图128所示的实施方式中,第一光栅层19A具有第一光栅结构14S1,第二光栅层19B具有第二光栅结构14S1,光波导10A为双层光栅架构。一种实施方式中,在基底层19S和第一光栅层19A之间也具有增粘层114。其它实施方式中,基底层19S和第一光栅层19A之间也可以直接接触,或设置其它的基材层,不设置增粘层。
具体地,请参考图129,图129是本申请一种实施方式提供的光波导10A各层的结构爆炸示意图。基底层19S呈表面平整的平板状,且包括基底顶面19SS1和基底底面19SS2。基底层19S的材质可以为玻璃或者树脂等透明度较高的材料。可以理解地,光波导10A可以为近眼显示设备的镜片的部分之一,不但要承担显示图像信息的任务,还需要具有透明透光的性能,以此才能够保证用户在佩戴电子设备1000时不影响行动。
一种实施方式中,第一光栅层19A设置在基底层19S的基底顶面19SS1上,与基底层19S形成层叠设置。第一光栅层19A的材质可以为高分子聚合物,具体可以为一种光固化、或热固化、或化学固化的材料。第一光栅层19A可以通过自身的粘连特性与基底层19S形成粘接。可以理解地,第一光栅层19A可以使用上述材料且在具有流动性或可变形性的情况下覆盖在基底层19S上,并等待固化后与基底层19S形成粘接。
一种实施方式中,第一光栅层19A在背离基底层19S的一面可以为第一顶面19AS,增粘层114可以直接形成在第一光栅层19A的第一顶面19AS。增粘层114的材质可以为透明度较高的高分子聚合物材料,并且具有粘接性。可以理解地,增粘层114需要透明度较高的原因是为了确保光波导10A的透光性,而增粘层114的粘接性是用于将第一光栅层19A和第二光栅层19B紧密粘接,提高光波导10A的可靠性。
第二光栅层19B层叠设置在增粘层114背离第一光栅层19A的一侧。增粘层114在背离第一光栅层19A的一面形成增粘顶面114S,第二光栅层19B设置在增粘层114的增粘顶面114S上。第二光栅层19B的材质可以与第一光栅层19A的材质相同或不同。并且,第二光栅层19B的制造工艺可以和第一光栅层19A相同。
一种可能的实施方式中,请参考图128和图129,基底层19S和第一光栅层19A之间也具有增粘层114。具体地,基底层19S的基底顶面19SS1上可以预先设置有增粘层114,然后将第一光栅层19A设置在增粘层114上。基底层19S和第一光栅层19A之间的增粘层114,与第一光栅层19A和第二光栅层19B之间的增粘层114的材质可以相同或不同。可以理解地,由于基底层19S和第二光栅层19B的材质不一定相同,所以为了确保增粘层114在基底层19S和第一光栅层19A之间也能够保持较高的粘接性,增粘层114可以使用适应于基底层19S的粘接材料。
本申请通过在第一光栅层19A和第二光栅层19B之间设置增粘层114,使得第一光栅层19A和第二光栅层19B分隔,所以在制作第二光栅层19B时不会由于压力或冲击力对第一光栅层19A造成影响,降低了第一光栅层19A变形损坏的概率。并且,利用增粘层114具有粘接性的特点,能够在第二光栅层19B与增粘层114连接后保持二者之间的牢固性,从而提高脱模的可靠性。同时,第二光栅层19B可以通过增粘层114粘接在第一光栅层19A上,从而提高了第一光栅层19A和第二光栅层19B连接强度,能够避免第一光栅层19A和第二光栅层19B之间松脱,有利于光波导10A的后续加工。
一种可能的实施方式中,所述增粘层114厚度在0~20nm之间。可以理解地,将增粘层114的厚度控制在该范围内,可以在不影响光波导10A的整体厚度的情况下,确保第一光栅层19A和基底层19S之间的连接强度。当增粘层114的厚度超过这个范围时,容易导致光波导10A的整体厚度过厚,且影响光线的折射。
一种可能的实施方式中,请参考图128和图129,所述第一光栅层19A和所述第二光栅层19B之间具有介质层115。具体而言,介质层115可以位于第一光栅层19A和增粘层114之间。具体介质层115可以设置在第一顶面19AS,介质层115背离第一光栅层19A的表面为介质顶面115S。增粘层114形成在介质顶面115S上。介质层115可以采用在可见光波段具有高透过率的材料。举例而言,可以采用氧化硅、氮化硅、氮化镓和二氧化钛等中的一种或多种,本发明对此不作限定。并且介质层115可以采用半导体制造工艺制作,以满足高量产、高精度的要求。介质层115的制作工艺可以包括涂胶、或曝光、和/或原子层沉积、和/或刻蚀、和/或除胶等工序。
一种可能的实施方式中,所述介质层115的折射率在1.8~2.3之间。介质层115的折射率高,能有效提升光效率,提高具有该光波导10A的电子设备1000的视场角。在其他实施方式中,介质层115的折射率还可以大于2.3。
图130是光线在图129所示的光波导10A中传播的光路示意图。一种可能的实施方式中,第一光栅层 19A背向基底层19S的一侧具有耦入光栅11,第二光栅层19B背向第一光栅层19A的一侧具有耦出光栅12,并且耦入光栅11在基底层19S上的垂直投影与耦出光栅12在基底层19S上的垂直投影具有间隔距离。耦入光栅11和光机20相对,光机20所发射的图像光线通过耦入光栅11进入光波导10A,并通过耦出光栅12耦出光波导10A。耦入光栅11和耦出光栅12均可以为光波导10A上的微纳米结构,具有衍射功能。
图131是图129所示的光波导10A得第一区域A和第二区域B的划分示意图。一种可能的实施方式中,光波导10A包括第一方向X和第二方向Y,第一方向X可以为光波导10A的长度方向,第二方向Y可以为光波导10A的厚度方向。光机和用户均可位于第二方向Y上的同侧。可以理解地,第二方向Y即为近眼显示设备的镜片的厚度方向。其中,基底层19S、第一光栅层19A、介质层115、增粘层114和第二光栅层19B沿光波导10A的第二方向Y依次层叠设置。光波导10A可以包括在第一方向X上并列设置的第一区域A和第二区域B,图131中虚线矩形框代表第一区域A和第二区域B。第一光栅层19A和第二光栅层19B均有至少部分位于第一区域A,并且还有部分位于第二区域B。光机可以与第一区域A正对,用户的眼睛可以与第二区域B正对。以此,光机可以向第一区域A发射图像光线,并经由第一区域A中的光栅结构耦入光波导,在光波导内全反射传播,且传播至第二区域B,并在第二区域B中,通过第二区域中的光栅结构耦出至人眼,形成供用户观看的虚拟图像。
一种可能的实施方式中,请参考图131,所述第一光栅层19A包括第一光栅结构14S1。具体地,第一光栅层19A包括相连接的第一光栅结构14S1和第一光栅层主体19A0,第一光栅结构14S1可以作为耦入光栅,用于将入射光线衍射至光波导内部。第一光栅结构14S1位于第一区域A,第一光栅层主体19A0位于第二区域B。
请参考图132,图132是本申请一种实施方式提供的第一光栅层19A的结构示意图。第一光栅结构14S1包括多个第一光栅单元14S1A。一种实施方式中,第一光栅单元14S1A可以为横截面为三角形的微纳米结构,也可以为其它形态的微纳米结构。在截面图上,多个第一光栅单元14S1A可以沿第一方向X呈周期性排列。相邻两个第一光栅单元14S1A之间形成第一凹槽14S1B。多个第一光栅单元14S1A可以具有相同的高度H1,具有相同的宽度L1,还具有相同的间距。可以理解地,第一光栅单元14S1A的具体形状尺寸可以根据所需折射的光线而具体设置,所以在不同尺寸的光波导10A中第一光栅单元14S1A的形状和尺寸可以不同。第一光栅层主体19A0位于第一光栅结构14S1的右侧,且第一光栅层主体19A0的截面为可以为矩形。第一光栅单元14S1A的高度H1可以与第一光栅层主体19A0的高度H3相同或不同。
图133所示为另一种第一光栅层19A的架构。一种可能的实施方式中,请参考图133,第一光栅单元14S1A的高度H1与第一光栅层主体19A0的高度H3不同。第一光栅层主体19A0的高度H3可以小于第一光栅单元14S1A的高度H1。相邻两个第一光栅单元14S1A之间具有第一凹槽14S1B。一种可能的实施方式中,第一光栅单元14S1A的高度H1可以在100~400nm之间,第一光栅单元14S1A的宽度L1可以在200-600nm之间。一种可能的实施方式中,请参考图132,第一光栅单元14S1A可以包括闪耀角α和反闪耀角β,其中闪耀角α为图中第一光栅单元14S1A右侧斜边与水平面所形成的角,反闪耀角β为图中第一光栅单元14S1A左侧斜边与水平面所形成的角。闪耀角α可以在为20~50°之间,反闪耀角β可以在70~90°之间。
一种可能的实施方式中,第一光栅层19A的折射率在1.6~1.9之间,一种可能的实施方式中,第一光栅层19A厚度在100~400nm之间。第一光栅层19A的折射率高,能有效提升光效率,提高具有该光波导10A的电子设备1000的折射率。在其他实施方式中,第一光栅层19A的折射率还可以大于1.9。同时,控制第一光栅层19A厚度在100~400nm之间能够有效控制光波导10A的整体厚度,实现具有该光波导10A的电子设备1000的轻薄化。
一种可能的实施方式中,请参考图131,第二光栅层19B包括相连接的第二光栅结构14S2和第二光栅层主体19B0,所述第一光栅结构14S1和所述第二光栅结构14S2可以具有不同的结构,所述第一光栅结构14S1和所述第二光栅结构14S2可以具有不同尺寸或周期。具体地,第二光栅结构14S2可以作为耦出光栅,用于将光波导内的光线耦出至人眼。第二光栅结构14S2位于第二区域B,第二光栅层主体19B0位于第一区域A和第二区域B。第二光栅结构14S2在基底层19S上的正投影和第一光栅层主体19A0在基底层19S上的正投影至少部分重合。第二光栅层主体19B0基底层19S上的正投影和第一光栅结构14S1在基底层19S上的正投影至少部分重合。
图134是本申请一种实施方式提供的第二光栅层19B的结构示意图。请参考图134,第二光栅结构14S2包括多个第二光栅单元14S2A。一种实施方式中,第二光栅结构14S2为倾斜光栅,第二光栅单元14S2A 可以为横截面为四边形的微纳米结构。在截面图上,多个第二光栅单元14S2A可以沿光波导10A的第一方向X呈周期性排列。多个第二光栅单元14S2A可以具有相同的高度H2,具有相同的宽度L2,也可以具有相同的间距D2。当然,在其他实施方式中,第二光栅单元14S2A的截面形状还可以为其他形状,或者多个第二光栅单元14S2A的具体尺寸不全相同,具体不做限制。
部分第二光栅层主体19B0位于第二光栅结构14S2的下方,即第二光栅结构14S2形成在部分第二光栅层主体19B0上。第二光栅层主体19B0的截面为可以为矩形。第二光栅层主体19B0具有高度H4。一种可能的实施方式中,第二光栅单元14S2A的高度H2和第二光栅层主体19B0的高度H4之和为第二光栅层19B的高度,第二光栅层19B的高度可以在100~400nm之间。第二光栅单元14S2A的宽度L1可以在200-600nm之间。第二光栅单元14S2A的倾斜角γ可以在20~50°之间。
图135是本申请一种实施方式提供的第二光栅层19B的结构示意图。参阅图135,一种实施方式中,第二光栅层19B可以具有双面光栅结构,即部分第二光栅结构14S2分布在第二光栅层主体19B0的顶面的一侧,部分第二光栅结构14S2分布在第二光栅层主体19B0的底面的一侧。结合参阅图131和图135,一种实施方式中,分布在第二光栅层主体19B0的顶面的第二光栅结构14S2可以位于第二区域B,分布在第二光栅层主体19B0的底面的第二光栅结构14S2可以位于第一区域A。如图135所示,一种实施方式中,分布在第二光栅层主体19B0的底面的第二光栅结构14S2的结构形态与分布在第二光栅层主体19B0的顶面的第二光栅结构14S2的结构形态不同,或者二者的排列周期不同,矢量方向不同。通过这样的不同的光栅架构的设计,可以调制光波导的衍射效率。
图136是本申请一种实施方式提供的第二光栅层19B的结构示意图。参阅图136,一种实施方式中,第二光栅层19B整体的厚度比图135所示的实施方式提供的第二光栅层的整体厚度薄。第二光栅结构14S2的多个第二光栅单元14S2A的顶面和第二光栅层主体19B0的顶面齐平。第二光栅结构14S2所在的第二光栅层19B的底面与第二光栅层主体19B0的底面共面。
图131所示的光波导中,在第一光栅层19A上通过设置介质层115,利用介质层115填充第一光栅结构14S1的第一凹槽14S1B,而且介质层115层叠在第一光栅层19A上构成平坦的表面,即介质顶面115S呈平面状。增粘层114形成在介质顶面115S,且在增粘层114还需要设置第二光栅层19B。通过介质层115构建的平坦的介质顶面115S,为制作增粘层114和第二光栅层19B提供了基础,具有方便制作,容易控制光波导衍射效率的优势。
图137为本申请一种实施方式提供的光波导的示意图。一种实施方式中,参阅图137,基底层19S和第一光栅层19A之间通过增粘层114连接,这层增粘层为平板状架构。第一光栅层19A的结构形态与图133所示的第一光栅层19A的结构形态相同或相似。介质层115呈薄膜状结构。介质层115覆盖在第一光栅层19A的表面,介质层115覆盖第一光栅结构14S1的表面。可以理解为,介质层115为厚度均匀地设置在第一光栅层19A背离基底层19S的表面的层结构。本实施方式中,介质层115不能构建一个平坦的表面来承载第二光栅层19B。介质层115的形态和第一光栅层19A的表面形态一致。本实施方式中,第二光栅层19B和介质层115之间具有增粘层114,这层增粘层114的形态与介质层115的形态一致。
图137所示的实施方式中,第二光栅层19B的底面与第一光栅层19A的顶面的结构形态相适配,以使第二光栅层19B贴合在增粘层114的表面。第二光栅层19B的表面通过与第一光栅层19A上的第一光栅结构14S1的形态一致,使得第二光栅层19B的底面形成光栅结构。可以理解的是,本实施方式中,第二光栅层19B上的第二光栅结构14S2分布在第二光栅层19B的顶面和底面。部分第二光栅结构14S2通过制作工艺形成在第二光栅层19B的顶面,还有部分第二光栅结构14S2是通过第二光栅层19B与第一光栅层19A的结构形成的。图137所示的实施方式提供的光波导具有薄型化的优势,还有利于提升光波导的衍射效率。
图138为本申请一种实施方式提供的光波导的示意图。参阅图138,一种实施方式中,基底层19S和第一光栅层19A之间通过增粘层114连接,这层增粘层为平板状架构。第一光栅层19A的结构形态与图132所示的第一光栅层19A的结构形态相同或相似。介质层115的结构形态与图131中的介质层115的结构形态相同或相似。介质层115层叠在第一光栅层19A上构成平坦的表面,即介质顶面115S呈平面状。增粘层114形成在介质顶面115S。第二光栅层19B和介质层115之间的增粘层114呈平板状架构。本实施方式中,第二光栅层19B的结构形态与图136所示的第二光栅层19B的结构形态相同或相似。
图139为本申请一种实施方式提供的光波导的示意图。参阅图139,一种实施方式中,基底层19S和第一光栅层19A之间通过增粘层114连接,这层增粘层为平板状架构。第一光栅层19A的结构形态与图133所示的第一光栅层19A的结构形态相同或相似。介质层115的结构形态与图137所示的实施方式中的 介质层115的结构形态相同或相似。即,介质层115呈薄膜状,覆盖在第一光栅层19A的表面。第二光栅层19B和介质层115之间的增粘层114的结构形态亦与图137所示的实施方式中的增粘层114的结构形态相同或相似。本实施方式中,第二光栅层19B的结构形态与前述实施方式不同。第二光栅层19B的底面亦形成光栅结构。第二光栅层19B上的第二光栅结构14S2分布在第二光栅层19B的顶面和底面。部分第二光栅结构14S2是通过第二光栅层19B与第一光栅层19A的结构形成的。部分第二光栅结构14S2通过制作工艺形成在第二光栅层19B的顶面,如图139所示,分布在第二光栅层19B的顶面的第二光栅结构14S2的顶面与第二光栅层19B的顶面共面,即,分布在第二光栅层19B的顶面的第二光栅结构14S2为内嵌在第二光栅层19B内部的结构。
本申请还提供一种光波导的制作方法,请参考图140,图140是本申请一种实施方式提供的光波导的制作方法流程图。本申请提供的光波导的制作方法用于制备上述各项实施方式中所提供的光波导。一种实施方式中,光波导制作方法具体包括步骤S1~S3。
步骤S1,在基底层上制作第一光栅层。
步骤S2,通过光栅结构模板制作第二光栅层,将第二光栅层制作在第一光栅层背离基底层的一侧,在第一光栅层和第二光栅层之间具有增粘层。
步骤S3,脱模光栅结构模板。
对于步骤S1的具体描述,一种具体的实施方式请参考图141,在基底层19S上制作第一光栅层19A,使得所述第一光栅层19A和所述基底层19S层叠设置。基底层19S可以为玻璃或者树脂等透明度较高的材料制成,基底层19S用于承载第一光栅层19A。第一光栅层19A可以通过纳米压印工艺形成。
如图141所示,在基底层19S上旋涂第一压印材料层112S,第一压印材料层112S具体可以为纳米压印胶。提供第一光栅结构模板412,通过纳米压印工艺,在纳米压印设备上把第一光栅结构模板412压到第一压印材料层112S上,然后固化第一压印材料层112S,脱模后得到第一光栅层19A。
具体而言,第一光栅结构模板412应该可以包括两个部分,分别为对应第一光栅结构14S1的第一模板结构4121,和对应第一光栅层主体19A0的第二模板结构4122。一种实施方式中,第一模板结构4121与第一光栅结构14S1的结构相适配,例如:第一光栅结构14S1呈锯齿状,第一模板结构4121为与第一光栅结构14S1形态互补的锯齿状。第二模板结构4122为与第一光栅层主体19A0相同的平面状。在其他实施方式中,第一光栅结构模板412可以仅有第一模板结构4121,即仅需第一光栅结构模板412按压在第一区域A的第一压印材料层112S,即可得到第一光栅结构14S1。
一种可能的实施方式中,固化第一压印材料层112S的方式可以为:光固化、或热固化、或化学固化等方式。一种可能的实施方式中,固化第一压印材料层112S的方式为紫外光固化,因为紫外光固化的工艺成熟且易于实现量产。
一种可能的实施方式中,第一压印材料层112S为高折射率纳米压印胶材料,例如聚有机硅氧烷类,第一光栅层19A的折射率在1.6~1.9之间。第一光栅层19A的厚度在100~400nm之间,可以理解地,第一光栅层19A的厚度应该指在光波导10A的厚度方向Y上,第一光栅层19A距离基底层19S最远处至距离基底层19S最近处的直线距离。设计第一光栅层19A的折射率在1.6~1.9之间,能有效提升第一光栅层19A的折光效率。并且第一光栅层19A采用纳米压印工艺形成,工艺简单,易于实现量产。
参阅图128和图129,一种可能的实施方式中,在基底层19S上制作第一光栅层19A之前,本申请提供的光波导制作方法还可以包括:在基底层19S上制作增粘层114,第一光栅层19A制作在增粘层114上。增粘层114的在0~20nm之间。可以理解地,将增粘层114的厚度控制在该范围内,可以在不影响光波导10A的整体厚度的情况下,确保第一光栅层19A和基底层19S之间的连接强度。当增粘层114的厚度超过这个范围时,容易导致光波导10A的整体厚度过厚,且影响光线的折射。
对于图140所提供的实施方式中的步骤S2(即通过光栅结构模板制作第二光栅层,在第一光栅层和所述第二光栅层之间具有增粘层)的具体描述如下。
参阅图128和图129,一种可能的实施方式中,增粘层114可以预先制作在第一光栅层19A上,然后在增粘层114上制作第二光栅层19B。
一种可能的实施方式中,请参考图142,图142是图140所示的实施方式中的步骤S2中光栅结构模板制作第二光栅层19B的步骤流程图。通过所述光栅结构模板制作所述第二光栅层19B的步骤,具体包括步骤S21~步骤S24。
步骤S21,在所述第一光栅层上制作介质层。
步骤S22,在所述介质层上涂覆所述增粘层。
步骤S23,在所述增粘层上涂覆第二压印材料层。
步骤S24,通过所述光栅结构模板在所述第二压印材料层上制作所述第二光栅层。
参阅图143,结合图示具体说明图142所提供的实施方式中的第二光栅层的制作方法。
图143所示的压印材料层113S为步骤S23中在增粘层上涂覆的第二压印材料层。图143所示的制作方法为在步骤23的基础上制作第二光栅层的具体方法(即步骤S24的具体描述)。提供第二光栅结构模板413,通过纳米压印工艺,在纳米压印设备上把第二光栅结构模板413压到第二压印材料层113S上,然后固化第二压印材料层113S,脱模后得到第二光栅层19B。
可以理解地,第二光栅结构模板413应该也可以包括为两个部分,分别为对应第二光栅结构14S2的第三模板结构4131,和对应第二光栅层主体19B0的第四模板结构4132。其中,第三模板结构4131与第二光栅结构14S2的形态相适配,具体而言,第二光栅结构14S2为斜条状光栅结构,第三模板结构4131可以为与第二光栅结构14S2互补的斜条状结构。第四模板结构4132可以为与第二光栅层主体19B0相同的平面状。在其他实施方式中,第二光栅结构模板413可以仅有第三模板结构4131,即仅需第二光栅结构模板413按压在第二区域B的第二压印材料层113S,即可得到第二光栅结构14S2。
概括而言,一种具体的实施方式中,第二光栅层19B可以通过纳米压印工艺形成,即提供第二光栅结构模板413,并采用第二压印材料层113S和第二光栅结构模板413共同作用获得第二光栅层19B。其中,第二光栅层19B所使用的材料可以和第一光栅层19A所使用的材料相同或不同。举例而言,第一光栅层19A所使用的材料可以为热固化材料,即通过加热的方式使得第一压印材料层112S固化形成第一光栅层19A。而第二光栅层19B所使用的材料可以为紫外光固化材料,即通过紫外光照射的方式使得第二压印材料层113S固化形成第二光栅层19B。
一种实施方式中,第二压印材料层113S的折射率在1.6~1.9之间,一种可能的实施方式中,第二压印材料层113S厚度在100~400nm之间。第二压印材料层113S的折射率高,能有效提升衍射效率。在其他实施方式中,第二压印材料层113S的折射率还可以大于1.9。同时,控制第二压印材料层113S厚度在100~400nm之间可以确保所得到的第二光栅层19B的厚度不超过该范围的最大值,从而能够有效控制光波导10A的整体厚度,实现光波导10A的轻薄化。
在其他实施方式中,图140所示的实施方式中的步骤S2的具体的制作方法还可以先使用光栅结构模板制作第二光栅层,再通过增粘层将第二光栅层粘接至第一光栅层,然后再脱模光栅结构模板。概括而言,通过将第二光栅层预先制作在光栅结构模板上,使得第一光栅层和第二光栅层的制作步骤可以同时进行,无需依顺序制作各层级结构;在分别制作第一光栅层和第二光栅层后再通过增粘层粘接,以此可以提高制造效率,有助于规模化生产。
一种可能的实施方式中,请参考图144,图144是图140所示的实施方式中的步骤S2中光栅结构模板制作第二光栅层19B在其他实施方式中的步骤流程图。通过所述光栅结构模板制作所述第二光栅层19B的步骤包括步骤S21’~步骤S23’。
步骤S21’,提供所述光栅结构模板。具体地,该步骤所提供的光栅结构模板可以为与第二光栅层相互补的第二光栅结构模板。
步骤S22’,在所述光栅结构模板上制作第二光栅层。具体地,在光栅结构模板上旋涂第二压印材料层,第二压印材料层具体可以为纳米压印胶。所述第一光栅层的材料和所述第二光栅层的材料可以不同,也可以相同。
步骤S23’,通过所述增粘层将连接所述光栅结构模板的所述第二光栅层粘接在所述第一光栅层上。
参阅图145,结合图示具体说明图144所提供的实施方式中的第二光栅层的制作方法。具体地,请参考图145,将第二压印材料层113S涂覆在第二光栅结构模板413上,第二光栅结构模板413上具有用于形成第二光栅结构14S2的微纳结构,第二压印材料层113S和第二光栅结构模板413结合,便在第二压印材料层113S上形成了第二光栅结构14S2。在第二压印材料层113S未固化前,可以在第二压印材料层113S背离第二光栅结构模板413的一面设置增粘层114。然后将第二压印材料层113S连同第二光栅结构模板413一起设置在第一光栅层19A上,再固化第二压印材料层113S。通过该方式设置的增粘层114可以通过第二压印材料层113S可形变的特点完全被覆盖在第一光栅层19A上,提高增粘层114的均匀性。
其它实施方式中,也可以在第一光栅层19A上设置增粘层114。然后将第二压印材料层113S连同第二光栅结构模板413一起设置在第一光栅层19A上,再固化第二压印材料层113S。
可以理解地,在第二压印材料层113S还具有可变形能力时,能够较为容易的将其设置在第一光栅层19A上。并且第二压印材料层113S和第一光栅层19A上的第一光栅结构14S1充分接触,以此第二压印材料层113S朝向第一光栅层19A的一面可以形成与第一光栅结构14S1互补的结构。在第二压印材料层113S固化形成第二光栅层19B后,第二光栅层19B朝向第一光栅层19A一面的表面形态与第一光栅层19A的表面形态相同。
图140所示的实施方式中的步骤S3中,脱模所述光栅结构模板的步骤可以在第二光栅层固化成型后,且通过增粘层和第一光栅层紧密连接后实行。
参阅图137、图138和图139,本申请通过在第一光栅层19A和第二光栅层19B之间设置增粘层114,使得第一光栅层19A和第二光栅层19B分隔,所以在制作第二光栅层19B时不会由于压力或冲击力对第一光栅层19A造成影响,降低了第一光栅层19A变形损坏的概率。并且,利用增粘层114具有粘接性的特点,能够在第二光栅层19B与增粘层114连接后保持二者之间的牢固性,从而提高脱模的可靠性。同时,第二光栅层19B可以通过增粘层114粘接在第一光栅层19A上,从而提高了第一光栅层19A和第二光栅层19B连接强度,能够避免第一光栅层19A和第二光栅层19B之间松脱,有利于光波导10A的后续加工。
参阅图137和图139,在第一光栅层19A上可以通过镀膜工艺制作介质层115。介质层115的厚度在0~50nm之间。具体的镀膜方式可以是电子束蒸镀、磁控溅射、原子层沉积等。通过镀膜工艺形成介质层115更易实现,能提高产品的量产性。一种可能的实施方式中,通过镀膜工艺制作的介质层115可以填充在第一光栅结构14S1的微纳结构的狭缝内。一种可能的实施方式中,所述介质层115的材料包括氧化物或氮化物,具体可以包括氧化硅、氮化硅、氮化镓和二氧化钛中的至少一种。一种可能的实施方式中,介质层115的材料可以为二氧化钛。一种可能的实施方式中,所述介质层115的折射率在1.8~2.3之间。
一种可能的实施方式中,介质层115也可以通过涂覆的方向形成在第一光栅层19A上,介质层115的厚度可以在100~400nm之间。
参阅图137、图138和图139,本申请提供的光波导制作方法包括在所述介质层115上涂覆所述增粘层114。所述增粘层114的厚度在0~20nm之间。可以理解地,将增粘层114的厚度控制在该范围内,可以在不影响光波导10A的整体厚度的情况下,确保第一光栅层19A和基底层19S之间的连接强度。当增粘层114的厚度超过这个范围时,容易导致光波导10A的整体厚度过厚,且影响光线的折射。增粘层114用于与第二光栅层结合。
本申请通过在涂覆增粘层114前在第一光栅层19A上制作介质层115,使得介质层115可以对第一光栅层19A形成力学保护,确保在压印第二光栅层19B的过程中第一光栅层19A不易变形。同时通过在第一光栅层19A表面制作介质层115还能够提高光线在第一光栅层19A的折射率,从而实现光波导10A的优异光学性能。
一种可能的实施方式中,通过所述增粘层将连接所述光栅结构模板的所述第二光栅层粘接在所述第一光栅层上的过程中,所述增粘层和所述第一光栅层可以直接接触,即增粘层和第一光栅层之间不设置介质层,可以实现光波导的减薄效果,以此在各层级厚度不变的情况下降低光波导的厚度。
参阅图143和图145所示的实施方式,通过所述光栅结构模板制作所述第二光栅层19B的步骤之前,光波导制作方法包括:对第二光栅结构模板413的工作表面做抗粘处理,通过第二光栅结构模板413在所述第二压印材料层113S上制作所述第二光栅层19B的过程中,第二光栅结构模板413的工作表面和所述第二压印材料层接触。具体地,第二光栅结构模板413的工作表面可以为第二光栅结构模板413上与第二压印材料层113S接触的表面。对工作表面进行抗粘处理是为了能够更为顺利的脱模,避免第二光栅层19B与第二光栅结构模板413粘连,防止破坏第二光栅结构14S2。抗粘处理的具体形式不做具体限制。举例而言,抗粘处理可以为对第二光栅结构模板413的工作表面进行蒸镀或浸润氟化物处理,从而便于脱模。在其他实施方式中,还可以为对工作表面涂覆抗粘剂,例如石蜡或是润滑油。
一种可能的实施方式中,在所述第一光栅层上制作介质层的步骤还包括:通过化学机械研磨工艺对所述介质层进度表面处理。具体地,可以对介质层的介质顶面进行表面处理,处理的目的在于提高该表面的粗糙度,从而提高介质层表面的吸附力,增加介质层和增粘层之间的结合力,避免增粘层脱落。
一种可能的实施方式中,在所述基底层上制作所述第一光栅层过程中,通过纳米压印工艺在所述第一压印材料层上形成第一光栅层,在这个过程中,第一压印材料承受的力为第一压力。通过增粘层将连接所述光栅结构模板的第二光栅层粘接在第一光栅层上的过程中,所述第一光栅层和所述第二光栅层承受的力为第二压力。第二压力小于等于第一压力。可以理解地,通过纳米压印工艺制作的第一光栅层和第二光栅 层均可以具有微纳米结构,在制作第一光栅层时,第一光栅层的下方为基底层,且基底层不具备微纳米结构,所以为了保证第一光栅层成型可以使用较大的第一压力。而在第一光栅层上制作第二光栅层时,第一光栅层上具备第一光栅结构,第一光栅结构为微纳米结构,为了防止压印力过大而破坏第一光栅结构,本申请限定第二压力小于等于第一压力,能够实现在制作过程中保护第一光栅层上的第一光栅结构。
方案十一:波导基底和保护层之间填充保护和减反结构
一种可能的实施方式中,请参考图146,光波导10A包括耦入光栅11和耦出光栅12。耦入光栅11和耦出光栅12均可以为光波导10A上的微纳米结构,具有反光和透光的能力。耦入光栅11和耦出光栅12可以位于镜片10上相同的一面或分别位于镜片10上相背的两面上。耦入光栅11和光机20相对,光机20所发射的光线投射至耦入光栅11上,入射光线通过耦入光栅11进入光波导10A,在光波导10A内进行全反射传播,并通过耦出光栅12投影至人眼,使人跟看到虚拟图像。
图147为一种光波导10A的截面示意图,光波导10A包括依次层叠设置光波导主体111、第一减反层112、填充主体层113、第二减反层114和表面保护层115,所述第一减反层112位于在所述光波导主体111和所述填充主体层113之间,所述填充主体层113的折射率和空气的折射率之间的差在第一预设范围内,所述第二减反层114位于所述填充主体层113和所述表面保护层115之间,所述第二减反层114的折射率呈渐变趋势变化,所述第二减反层114与所述填充主体层113邻近的部分的折射率和所述填充主体层113之间的折射率差在第二预设范围内,所述第二减反层114与所述表面保护层115邻近的部分的折射率和所述表面保护层115之间的折射率差在第三预设范围内。
本申请通过在表面保护层115和光波导主体111之间设置填充主体层113,由于填充主体层113的折射率较小,例如接近空气,填充主体层113的折射率和表面保护层115的折射率之间存在折射率差,填充主体层113的折射率和光波导主体111之间的折射率之间亦存在折射率差,若不设置第一减反层112和第二减反层114,在填充主体层113和光波导主体111之间连接的位置及在填充主体层113和表面保护层115之间的连接位置均会有光线反射,此反射影响光波导的透光性。因此,本申请通过设置第一减反层112和第二减反层114实现光波导整体的减反射效果。
对于第一减反层112而言,可以为单层膜层架构,此情况下,第一减反层112的折射率跟上下两个界面的介质(填充主体层113和光波导主体111)折射率相关,估算为两者(填充主体层113的折射率和光波导主体111的折射率)乘积开平方,第一减反层112的厚度为入射波长的1/4。第一减反层112也可以为多层膜结构,若为多层膜结构,要求多层膜层的等效折射率为上述值,才能达到界面处反射率较低(理论上减为0),起到该表面处减反的作用。
具体地,图147和图148所示的光波导10A包括:自下而上依次分布的光波导主体111、第一减反层112、填充主体层113、第二减反层114和表面保护层115。其中图148为图147的结构爆炸示意图,光波导主体111可以为一种光波导晶圆,并包括相背离的第一表面1111和第二表面1112,第一减反层112设置在第二表面1112上。光波导主体111一方面用于接收光机的入射光线且将此入射光线耦入,使入射光线在其中进行全反射传播,并耦出至人眼形成虚拟图像。具体而言,光波导主体111包括耦入光栅、耦出光栅及波导基底,耦入光栅用于接收光机发送的入射光线,并将入射光线耦入波导基底内,且在波导基底内进行全反射传播,在波导基底内传播的光线遇到耦出光栅时,耦出光栅将光线耦出至人眼,形成虚拟图像。另一方面,光波导主体111用于透射环境光。
图147和图148示意性地表达一种实施方式提供的光波导10A的厚度方向上截面图,可以理解地,光波导主体111整体的面积或外轮廓的形状不做具体限制。制作光波导主体111的材料可以为硅或二氧化硅等,具体不做限制。光波导主体111可以具有透光性,一种可能的实施方式中,光波导主体111的折射率为1.9。在其他实施方式中,光波导主体111的折射率还可以为1.7、或1.8、或2.0。
一种可能的实施方式中,请参考图147和图148,第一减反层112包括相背离的第三表面1121和第四表面1122,其中第三表面1121和第二表面1112相接触。第一减反层112可以由一种透光材料制成,并且制作第一减反层112的材料的折射率可以接近于空气的折射率。可以理解地,折射率是光在真空中的传播速度与光在该介质中的传播速度之比。材料的折射率越高,使入射光发生折射的能力越强,但是长期使用高折射率的材料作为镜片可能会对眼睛有一定的损害,长期配戴可能会导致视觉质量下降,眼睛看不清楚物体,导致色散加重,对于视力也会造成影响。所以为了确保近眼显示设备的安全性,本申请中使用低折射率的材料作为第一减反层112。举例而言,制作第一减反层112的材料为硅氧烷聚合物。并且第一减反 层112的折射率可以为1.37。当然,在其他实施方式中第一减反层112的折射率还可以为1.2、或1.3、或1.4等。
一种可能的实施方式中,制作第一减反层112的材料还可以具有较低的雾度。雾度(haze)是偏离入射光2.5°角以上的透射光强占总透射光强的百分数,雾度越大意味着薄膜光泽以及透明度尤其成像度下降。所以本申请在选取制作第一减反层112的材料时,还需考虑材料的雾度,以此提高第一减反层112的透明度还成像效果。举例而言,第一减反层112的雾度可以低于1%。
一种可能的实施方式中,制作第一减反层112的工艺方法包括但不限于电子束蒸镀、溅射、原子层沉积(ALD,Atomic Layer Deposition)、物理气相沉积(PVD,Physical Vapor Deposition)、化学气相沉积(CVD,Chemical Vapour Deposition)等。
一种可能的实施方式中,所述第一减反层112通过镀膜的方式形成在所述光波导主体111的表面。并且,所述第一减反层112的厚度可以为137.5nm。
一种可能的实施方式中,请参考图147和图148,填充主体层113包括相背离的第五表面1131和第六表面1132,其中第五表面1131和第四表面1122相接触。填充主体层113也可以由一种透光材料制成,且具有低折射率和低雾度。一种可能的实施方式中,填充主体层113的折射率和空气的折射率之间的差在第一预设范围内。举例而言,第一预设范围可以为0.1~0.4。由于空气的折射率为1,所以填充主体层113的折射率可以在1.1~1.4之间。一种可能的实施方式中,所述第一预设范围为小于等于0.25的范围。举例而言,填充主体层的折射率可以在1.1~1.25的范围。将填充主体层的折射率控制在小于等于0.25的范围内,主要为在实现光波导主体与表面保护层之间的填充保护,使光波导主体与表面保护层相对固定的同时,填充主体层的折射率趋近于空气的折射率,可以不影响光波导的视场角。
填充主体层113的雾度可以小于1%。一种可能的实施方式中,制作填充主体层113的材料也可以为硅氧烷聚合物。但是由于硅氧烷聚合物包括多种分子结构类型,所以制作填充主体层113所使用的硅氧烷聚合物可以与第一减反层112相同或不同。
一种可能的实施方式中,请参考图147和图148,第二减反层114包括相背离的第七表面1141和第八表面1142,表面保护层115包括第九表面1151,其中第七表面1141和第六表面1132相接触,第八表面1142与第九表面1151相接触。第二减反层114也可以由一种透光材料制成,且具有低折射率和低雾度。一种可能的实施方式中,第二减反层114的折射率可以自下而上呈渐变趋势变化。
一种实施方式中,第二减反层114的第七表面1141与填充主体层113的第六表面1132的折射率差在第二预设范围内。一种可能的实施方式中,所述第二预设范围为小于等于0.1的范围。第二减反层114的第八表面1142与表面保护层115的第九表面1151的折射率差在第三预设范围内。一种可能的实施方式中,所述第三预设范围为小于等于0.1的范围。本申请通过限定第二预设范围和第三预设范围小于等于0.1,能够使得第二减反层相背两面的折射率可以与相连接的层级的折射率趋近,以此能够减少不同层级之间的反射效果,从而利用第二减反层实现减反效果,增强光波导的整体光学透过效率。
一种可能的实施方式中,表面保护层115的折射率可以为1.4,例如表面保护层115为玻璃材质或树脂材质。本申请不限定表面保护层115的折射率,可以根据光波导具体的应用环境选择不同的表面保护层,表面保护层115的折射率也随着材质、尺寸等变化而不同。
本申请通过在光波导主体111和表面保护层115之间设置填充主体层113,能够实现对光波导主体111和表面保护层115的支撑和保护,避免光波导主体111受环境因素影响光学性能;由于填充主体层113和光波导主体111之间邻接的表面,以及表面保护层115和填充主体之间邻接的表面均会产生光的反射,影响光波导10A的透过率,所以本申请还在光波导主体111和填充主体层113之间设置第一减反层112,在填充主体层113和表面保护层115之间设置第二减反层114以解决光反射问题,第一减反层112可以为镀膜的方式形成在光波导主体111的表面,通过光干涉原理实现光波导主体111的全反射,第一减反层112可以改善光波导界面处的散射吸收问题,增加该界面处的减反增透效果。第二减反层114具渐变的折射率的方案,在表面保护层115和填充主体层113之间形成梯度变化的折射率设计,解决表面保护层115和填充主体层113之间的光反射问题,提升光波导10A的透光性。由于光波导主体111表面会形成用于传到光线的光栅结构(包括耦入光栅、耦出光栅、中继光栅),例如,光栅结构的类型可以为浮雕光栅,所以在光波导主体111和表面保护层115之间设置填充主体层113可以保护光栅结构不被剐蹭刮伤,提升光波导主体111的使用寿命,保证衍射效率。
一种可能的实施方式中,所述第一预设范围为小于等于0.25的范围。举例而言,填充主体层113的折射率可以在1.1~1.25的范围。所以第一预设范围应该为小于等于0.25的范围。将填充主体层113的折射率 控制在上述范围内,主要为在实现光波导主体111与表面保护层115之间的填充保护,使光波导主体111与表面保护层115相对固定的同时,填充主体层113的折射率趋近于空气的折射率,可以不影响光波导10A的视场角。
一种可能的实施方式中,第二减反层114的折射率可以在1.1~1.4的范围内渐变。如填充主体层113的折射率为1.1时,第七表面1141的折射率也可以为1.1或趋近于1.1;或者,当填充主体层113的折射率为1.25时,第七表面1141的折射率也可以为1.25或趋近于1.25。一种可能的实施方式中,表面保护层115的折射率为1.4,第八表面1142的折射率可以为1.4或趋近于1.4。第二预设范围和第三预设范围均为小于等于0.1的范围。本申请具体实施方式能够使得第二减反层114相背两面的折射率可以与相连接的层级的折射率趋近,以此能够减少不同层级之间的反射效果,从而利用第二减反层114实现减反效果,增强光波导10A的整体光学透过效率。
一种可能的实施方式中,所述填充主体层113的折射率和空气的折射率之间的差在0.1~0.25之间。一种可能的实施方式中,所述填充主体层113的厚度在30~50μm之间。具体地,控制填充主体层113的折射率和厚度,避免填充主体层113的折射率过大,从而有利于控制光波导10A整体的折射率在合适的范围内,避免用户视力受损。本方案通过对填充主体层113的厚度的约束,可以有效地实现对光波导主体111的支撑,避免光波导10A过厚或过薄。
一种可能的实施方式中,请参考图149,所述填充主体层113包括基底113A和折光介质113B,所述折光介质113B分散在所述基底113A内。基底113A的具体材质可以为硅氧烷聚合物。折光介质113B的具体形式不做限制,可以为颗粒状的微球,也可以是形成在填充主体层113内的空心区域。举例而言,折光介质113B可以是颗粒材料,并且折光介质113B的折射率可以与基底113A的折射率不同。分散在基底113A内的遮光介质可以用于调节填充主体层113的折射率,例如,可以实现得填充主体层113的折射率接近空气的折射率。可以理解地,基底113A的材质可以与第一减反层112的材质相同,均使用折射率为1.37的硅氧烷聚合物。然而,为了使得填充主体层113的折射率与第一减反层112的折射率不同,所以可以通过加入折射率更低的折光介质113B降低填充主体层113的折射率。
一种可能的实施方式中,请参考图149,折光介质113B为树脂颗粒。使用树脂颗粒作为折光介质113B的原因是树脂颗粒具有较好的透光性,对可见光的透光性高。因此加入树脂颗粒到基底113A中,不会影响填充主体层113的透光性。并且使用树脂颗粒作为折光介质113B还有利于填充主体层113结构的稳定性,因为树脂颗粒与硅氧烷聚合物的化学性质相近,所以在填充主体层113制作成型后,基底113A和折光介质113B之间不容易分离,基底113A和折光介质113B之间的粘合性更好,易于封装。
一种可能的实施方式中,所述树脂颗粒的折射率为1。可以通过选用折射率较低的树脂颗粒作为折光介质113B,然后通过调节树脂颗粒在基底113A内的含量和分布情况,从而达到控制填充主体层113的折射率的目的。
一种可能的实施方式中,所述树脂颗粒的粒径在0.1~100μm之间。树脂颗粒的外观形状可以为圆球形,并且通过喷雾造粒的方法制作成型。控制树脂颗粒的粒径在上述范围内,有利于填充主体层113的成型,且树脂颗粒的制造难度较低,易于工业化生产。当树脂颗粒的粒径小于上述范围时,树脂颗粒的尺寸过小,制造难度加大;当树脂颗粒的粒径大于上述范围时,树脂颗粒的尺寸过大,不利于填充主体层113的成型。
一种可能的实施方式中,请参考图149,所述树脂颗粒为内部空心结构。具体地,树脂颗粒可以为核壳结构,其外壳为树脂材料成型,内核可以为空气。此设计的目的在于使得树脂颗粒的折射率能够更为接近空气。当然,在其他实施方式中,树脂颗粒还可以为实心的核壳结构。举例而言,树脂颗粒的外壳为树脂材料成型,内核可以为其他接近空气折射率的材料支撑。
一种可能的实施方式中,所述基底113A的折射率为1.4。具体地,基底113A的折射率可以为1.4左右,如上述实施方式所述,基底113A的材质可以与第一减反层112的材质相同的硅氧烷聚合物。使用与第一减反层112的材质相同的硅氧烷聚合物的原因是,利用相同材质作为基底113A的填充主体层113更容易与第一减反层112粘合,能够避免由于材料不同而出现的层分离现象。并且,还可以减少更换材料的步骤,同种材料易于获取,有利于工业化生产和降低成本。
一种可能的实施方式中,请参考图150,所述填充主体层113为气凝胶。具体地,气凝胶是指通过溶胶凝胶法,采用干燥方式使气体取代凝胶中的液相而形成的一种纳米级多孔固态材料,并且气凝胶的密度极低。由于气凝胶的成型方式和多孔的特性,所以使用气凝胶作为填充主体层113,更容易控制其折射率范围内。填充主体层113为类似气凝胶的多孔固态材料,一方面可以保证填充主体层113的折射率接近空气,另一方面,也使填充主体层113具有支撑的作用,填充主体层113在表面保护层115和光波导主体111 之间能够对表面保护层115提供较好的缓冲和支撑作为,保护表面保护层115,避免表面保护层115受外力损坏。一种可能的实施方式中,填充主体层113可以为通过正硅酸酯、甲基三甲氧基硅烷等硅源制作的气凝胶。通过以气凝胶为填充主体层113,不但可以节省混合基底113A和折光介质113B的步骤,减少制备工艺;还可以降低填充主体层113的制造成本。
一种可能的实施方式中,所述第二减反层114的折射率在1.1~1.4之间。一种可能的实施方式中,所述第二减反层114的厚度在1~2μm之间。具体地,控制第二减反层114的折射率和厚度,避免第二减反层114的折射率过大,从而有利于控制光波导10A整体的折射率在合适的范围内,避免用户视力受损。
图151为一种可能的实施方式中第二减反层114的截面结构示意图,所述第二减反层114包括多个层叠设置的第二减反子层114A,任意相邻两层所述第二减反子层114A的折射率之间的差在预设范围内。举例而言,图152为一种具有四层第二减反子层114A的结构示意图,第二减反层114自第七表面1141向第八表面1142的方向上,可以依次包括第二减反子层A1、第二减反子层A2、第二减反子层A3、第二减反子层A4。并且第二减反子层A1朝向填充主体层113的一面为第七表面1141,第二减反子层A4朝向表面保护层115的一面为第八表面1142。任意相邻两层第二减反子层114A的折射率之间的差在预设范围(例如0.1或0.05)内。该预设范围内可以根据第二减反层114的具体设计需求而确定。例如,第二减反子层A1的折射率与第二减反子层A2的折射率差为0.1;第二减反子层A1的折射率可以为1.1,第二减反子层A2的折射率可以为1.2。当然在其他实施方式中,还可以为其他的数值。即可以理解为第二减反子层114A的折射率均不相同。在其他实施方式中,第二减反子层114A的数量还可以为更多或更少,具体不做限制。
一种可能的实施方式中,自所述光波导主体111至所述表面保护层115的方向上,多个所述第二减反子层114A的折射率沿梯度递增。举例而言,第二减反子A1的折射率可以为1.1,第二减反子层A2的折射率可以为1.2、第二减反子层A3的折射率可以为1.3、第二减反子层A4的折射率可以为1.4。所以,任意相邻两层第二减反子层114A的折射率之间的差可以为0.1。在其他实施方式中,任意相邻两层第二减反子层114A的折射率之间的差可以为0.2或0.05,具体不做限制。
图153为一种可能的实施方式中第二减反层114的截面结构示意图,第二减反子层114A均由气凝胶制备而成。并且如图所示,每层中的孔隙率可以不同。可以理解地,图中六边形仅为气孔示意图,并非气孔的实际形状。
通过将第二减反层114设计为多个第二减反子层114A的方式,有利于第二减反层114的分步多次制备,提高第二减反层114的成型精度,并且第二减反子层114A的折射率不全相同,有利于通过多种不同的折射率逐步减少光线反射。
一种可能的实施方式中,所述第二减反层114和所述填充主体层113的材料相同,密度不同。具体地,制作第二减反层114的材料可以为上述实施方式中的硅氧烷聚合物和折光介质113B的混合,所以第二减反层114的材质可以和填充主体层113的材料相同。但是为了设计第二减反层114和填充主体层113的折射率不同,所以硅氧烷聚合物和折光介质113B的比例不同,导致二者的密度不同。在其他实施方式中,第二减反层114还可以为气凝胶。通过调节气凝胶中孔洞密度可以制作出不同折射率的第二减反子层114A。
一种可能的实施方式中,所述第二减反层114和所述填充主体层113通过同样的制作工艺形成。
一种可能的实施方式中,请参考图154,填充主体层113可以为上述实施方式中的树脂颗粒和硅氧烷聚合物制作而成,第二减反层114可以为上述实施方式中的气凝胶制作而成。当然,请参考图155,在其他实施方式中,填充主体层113可以为上述实施方式中的气凝胶制作而成,第二减反层114可以为上述实施方式中的树脂颗粒和硅氧烷聚合物制作而成。可以理解地,本申请提供了两种不同类型的膜层结构,分别为具有基底113A和折光介质113B的膜层结构,和气凝胶膜层结构。填充主体层113和第二减反层114可以通过两种膜层结构中任一种构成,也可以通过两种膜层结构组合构成。
一种可能的实施方式中,请参考图156,可以在第二减反层与表面保护层制作一层50nm以内的增粘层116,用于增加两者之间的封装强度。
本申请还提供一种光波导10A的制备方法,请参考图157,图157是本申请一种实施方式提供的光波导10A的制备方法流程图。具体制备上述各项实施方式中所提供的光波导10A。制备方法具体包括步骤S1~S3。
步骤S1,在光波导主体上制作第一减反层,使得所述第一减反层和所述光波导主体叠设置。
具体地,提供光波导主体,并在光波导主体上制作第一减反射层。第一减反层应该为上述实施方式中的硅氧烷聚合物制成。第一减反层可以通过电子束蒸镀工艺和/或溅射和/或ALD工艺和/或PVD工艺和/或CVD工艺制作成型。并且第一减反层的折射率可以为1.37,且厚度为137.5nm。
一种可能的实施方式中,第一减反层可以通过多次制作成型。举例而言,第一减反层可以为多层结构,可以通过上述工艺中的一种或多种分别制作多层子系减反层,多层子系减反层共同组成第一减反层。并且每一子系减反层的折射率可以相同,均为1.37,以此确保第一减反层各处的折射率均相同。但是,多层子系减反层的厚度可以相同也可以不全相同。其原因在于,第一减反层可以通过多次制作,以使得第一减反层的厚度可以精准,所以每一子系减反层的厚度可以依据之前子系减反层的厚度总和而确定。多次制作成型的好处在于可以精准调控第一减反层的厚度,也可通过该方式制作出不同厚度规格的第一减反层用于不同规格需求的光波导中。
步骤S2,在所述第一减反层背离所述光波导主体的一侧制作填充主体层。
具体地,请参考图158和图160,步骤S2可以包括步骤S21~S23,且具体如下所示。
步骤S21,在基底材料中加入折光介质,并均匀混合得到填充主体材料。其中,基底材料可以为上述中的折射率为1.4的硅氧烷聚合物。在硅氧烷聚合物溶液中加入折光介质。通过折光介质的与基底材料的配比调控出折射率在1-1~1.25范围内的填充主体材料。
一种可能的实施方式中,基底材料还可以是折射率为1.5的硅氧烷聚合物或1.3的硅氧烷聚合物。选用硅氧烷聚合物的原因在于其透光性较好且成本低廉。并且,填充主体层的基底材料与第一减反层相同或相近,更有利于制作成型。当然,在其他实施方式中,还可以选用其他材料作为基底材料,具体不作限制。可以理解地,本申请使用基底材料和折光介质制作填充主体层的原因在于,可以通过调控配比提供折射率范围较大的材料。相对于使用单一材料制作的方式而言,为了满足较大折射率范围的需求,所以需要提供多种折射率不同的单一材料,成本较高。而通过调控的方式,所需的原料种类少,可以降低成本。
一种可能的实施方式中,基底材料和折光介质的混合方式可以是使用高剪切混合器或三辊轧机充分混合。上述混合方式已经是较为成熟的技术,易于工业化。
步骤S22,通过多次匀胶法、或辊涂超声喷雾法、或空气喷雾法、或提拉法在所述第一减反层上涂覆所述填充主体材料。涂覆填充主体材料的厚度可以为30~50μm。
步骤S23,将所述填充主体材料固化,得到所述填充主体层。
具体地,请参考图160,可以将制备好第一减反层的光波导主体固定在一个旋涂基台上,旋涂基台是一个表面上有很多真空孔以便固定硅片的平的金属或聚四氯乙烯盘。将填充主体材料设置在第一减反层背向旋涂基台的一面,然后通过旋转旋涂基台使得光波导主体和第一减反层旋转后得到一层均匀平铺的填充主体材料。然后在步骤S23中可以通过UV光照射的方式,使得催化剂与硅氧烷聚合物中的官能团交联,从而现实填充主体材料固化,以形成均匀填充主体层。当然,在其他实施方式中,步骤S23中的固化方式还可以为热固化或化学固。可以理解地,步骤S23的目的在于将填充主体材料固化,形成完整的固体膜结构,所以具体固化方式不做限制。
一种可能的实施方式中,请参考图159和图160,在基底材料中加入折光介质的步骤还可以包括制作折光介质,具体如下。
步骤S211,将折光材料加入分散液中,并均匀混合。具体地,折光材料可以为水溶性树脂,分散液可以为纯净水。通过充分搅拌,水溶性树脂可以溶解在纯净水中。选用水溶性树脂的好处在于,此类材料的获取工艺和使用方法较为成熟,且获取成本低廉。同时,水溶性树脂以水位溶剂,不会产生化学污染,有较好的环保属性。
步骤S212,通过喷雾造粒法将所述折光材料制作得到所述折光介质,所述折光介质的粒径在0.1~100μm之间。具体地,喷雾造粒法是通过喷雾干燥机的机械作用,将需干燥的物料,分散成很细的像雾一样的微粒,在微粒与热空气接触的瞬间将大部分水分除去,使物料中的固体物质干燥成粉末。喷雾干燥相比于普通干燥而言,多了造粒的功能,能减小成品颗粒尺寸且形貌相对规整。一种可能的实施方式中,喷雾干燥的温度可以为100℃-130℃,喷料速度为10mL/min-30mL/min。上述实施方式中所提供的分散液沸点为100℃,所以为了充分去分散液得到折光介质,可以将干燥喷雾机的温度设置在100℃以上,且不高于130℃。当干燥温度低于该范围的下限时,干燥温度不足,会造成分散液去除不充分,干燥腔体中出现大量液滴,达不到干燥的目的。当干燥温度高于该范围的上限时,可能会导致折光介质受热过高从而被熔化。
一种可能的实施方式中,请参考图161和图162,填充主体层还可以为气凝胶,所以在所述第一减反层背离所述光波导主体的一侧制作填充主体层可以包括如下步骤。
步骤S21’,在溶剂中加入硅源材料,并涂覆在所述第一减反层上。具体地,硅源材料可以为气凝胶的 前驱体溶液。请参考图162,具体制备方式可以为,将硅源和溶剂按特定体积比分数混合,并且硅源和溶剂体积比可以根据折射率的需求设定,本申请不做限制。然后加入碱性催化剂,以使得硅源可以水解缩合,从而得到具有流动性的硅源材料。然后将制备好第一减反层的光波导主体放在旋涂基台上,通过旋转旋涂基台,将硅原材料均匀涂覆在第一减反层上等待下一步骤。其中,硅源包括正硅酸酯、甲基三甲氧基硅烷等中的一种或多种,溶剂包括甲醇、乙醇和水中的一种或多种。
步骤S22’,通过酸碱两步法和酒精超临界干燥法将所述硅源材料固化,得到所述填充主体层。具体地,在硅原材料涂覆在第一减反层上后,可以通过超临界干燥法将硅源材料固化,从而可以得到由气凝胶构成的填充主体层。
上述步骤的目的在于,以气凝胶作为填充主体层,并且气凝胶中气孔可调的特性,通过超临界干燥法在第一减反层上制作出具有符合折射率要求的气凝胶,相对于上述实施方式中的基底和折光介质,制作气凝胶的步骤简单,且材料成本较低。
请参考图157,本申请提供的制备方法还包括步骤S3,在所述填充主体层背离所述第一减反层的一侧制作第二减反层,所述第二减反层的折射率呈渐变趋势变化。
具体地,制作第二减反层可以包括在所述填充主体层背离所述第一减反层的一侧制作多个层叠设置的第二减反子层,自所述光波导主体至所述表面保护层的方向上,多个所述第二减反子层的折射率沿梯度递增。多个第二减反子层可以通过分步制作的方式逐个制作,并且可以通过调节制作第二减反子层的原料属性,从而获得不同折射率的第二减反子层。
一种可能的实施方式中,请参考图163和图164,在所述填充主体层背离所述第一减反层的一侧制作多个层叠设置的第二减反子层的步骤包括:
步骤S31,在基底材料中加入折光介质,并均匀混合得到填充主体材料。该步骤的具体实现方式可以参照步骤S21。
步骤S32,将所述填充主体材料和所述基底材料按预设比例混合后得到多组第二减反材料,多组所述第二减反材料的折射率不同。具体地,可以在上述步骤的基础上,向填充主体材料内添加基底材料,该步骤的实现方式类似于稀释。通过添加不同比例的基底材料从而可以获得不同折射率的第二减反材料。举例而言,请参考图164,提供多组填充主体材料,然后分别在多组填充主体材料内添加不同质量的基底材料,充分搅拌后获得多组折射率不同的减反材料。填充主体材料的折射率可以在1.1~1.25的范围内。然后通过添加折射率为1.4的基底材料,可以提升其所混合的材料的折射率。以此可以获得折射率在1.1~1.4范围内的第二减反材料。
步骤S33,在所述填充主体层上依次涂覆并固化多组所述第二减反材料,得到多个层叠设置的所述第二减反子层。该步骤可以通过多次匀胶法实现,具体可以参照步骤S22,即在旋涂基台上通过旋转涂覆成膜的方式,平铺第二减反材料。根据上述步骤制得的多种折射率的第二减反材料并按照折射率由小至大,通过多次的旋涂和固化,可以得到多个层叠设置的第二减反子层。并且每一层第二减反子层的厚度可以相同或不同。一种可能的实施方式中,第二减反层的总厚度应该在1~2μm。所以第二减反子层的厚度可以为0.3μm、或0.5μm、或0.8μm。
以上述步骤S31~步骤S33所提供的方法制作第二减反子层,其特点在于可以利用上述实施方式中所提供的填充主体材料,辅以不同比例的基底材料,从而调配出多种不同折射率的第二减反材料,优势在于无需新增配料,利用填充主体层的现有材料即可继续制备,且无需改动工艺生产线,适用于大批量生产,成本可控。
一种可能的实施方式中,请参考图165,第二减反子层还可以为气凝胶,在所述填充主体层背离所述第一减反层的一侧制作多个层叠设置的第二减反子层的步骤可以包括:
步骤S31’,在溶剂中加入硅源材料,得到多组第二减反材料,多组所述第二减反材料中所述硅源材料和所述溶剂的体积比不同。该步骤的具体实现方式可以参照步骤S21’。
步骤S32’,在所述填充主体层上依次涂覆并固化多组所述第二减反材料,得到多个层叠设置的所述第二减反子层。该步骤的具体实现方式可以参照步骤S22’。根据上述步骤制得的多种折射率的第二减反材料并按照折射率由小至大,通过多次的超临界干燥,可以得到多个层叠设置的第二减反子层,并且每一层第二减反子层的厚度可以相同或不同。
以上述步骤所提供的方法制作第二减反子层,其特点在于可以利用上述实施方式中所提供的填充主体材料,辅以不同比例的硅源材料,即可以通过不同浓度配比的第二减反材料制作出多种孔隙率的气凝胶,优势在于无需新增配料,利用填充主体层的现有材料即可继续制备,且无需改动工艺生产线,适用于大批 量生产,成本可控。
请参考图156和图157,本申请提供的制备方法还包括步骤S4,在所述第二减反层背离所述填充主体层的一侧制作表面保护层。具体地,可以在第二减反层与表面保护层制作一层50nm以内的增粘层,从而增加两者之间的封装强度。
方案十二:柔性光波导及制作方法
本申请一种实施方式提供的光波导的波导基底为硬质板状,例如,波导基底的制作过程是在硬质的玻璃基板上设置高折波导材料形成波导基底,玻璃基板本身就是硬质板状,以玻璃基板为承载体制作形成的光波导自然也是硬质板状,形成在波导基底上的光栅结构也随之成为硬质状。呈硬质平板状的光波导没有柔性,不能弯曲。
光波导应用在近眼显示设备中,例如AR眼镜,一方面需要能将光机的入射光投射至人跟形成虚拟图像,另一方面需要和近眼显示设备的镜片结构,具有透过环境光的功能。众多情况下,镜片需要具有曲面形态,例如用于近视眼的镜片。对于平板状硬质的光波导而言,与具有曲面的镜片结合的过程中,由于光波导的硬质特性,无法弯曲,无法匹配镜片的曲面的外形,镜片的厚度就需要足够大,以使镜片可以和平板状的硬质光波导结合且连接为一体。这样的设计会导致镜片厚且重,在镜片轻薄的设计方面形成障碍。
本申请具体实施方式提供一种光波导及光波导的制作方法。光波导具有柔性,能够任意弯曲,可以匹配不同曲面形态的镜片,有利于镜片的轻薄设计。
一种实施方式中,参阅图166,本申请提供的光波导10A具有变形特性,以使得所述光波导10A能够适配所述近眼显示设备的不同曲率的镜片。光波导10A包括第一波导基底19S1和形成在所述第一波导基底19S1的表面的第一光栅结构14S1。第一波导基底19S1用于光路的全反射,第一光栅结构14S1可以用于光的衍射,例如,第一光栅结构14S1可以为耦入光栅、耦出光栅,通过耦入光栅将光机投射的入射光线耦入第一波导基底19S1,入射光线进入第一波导基底19S1后在第一波导基底19S1中进行全反射传播,光线传播至耦出光栅位置时,由耦出光栅耦出至人眼,形成虚拟图像。本实施方式中,第一波导基底19S1和第一光栅结构14S1均呈柔性,可以理解为光波导10S中所有的结构均为柔性,以使光波导10S可以任意弯曲,以匹配不同曲率的镜片,实现镜片的轻薄化,带来近眼显示设备的轻量化。
图166所示为光波导10A的一种展平状态下的示意图,光波导10A未与镜片结合的状态下,为柔性可以任意弯曲的状态。参阅图166和图167,光波导10A可以和曲面的镜片10结合,或者光波导10A可以与镜片10的曲面部分结合。图167中上面的图所示为:光波导10A贴合在镜片10的表层,光波导10A与镜片10贴合的过程中,第一光栅结构14S1可以位于第一波导基底19S1和镜片10之间,第一光栅结构14S1也可以位于第一波导基底19S1背离镜片10的一侧。图167中下面的图所示为:光波导10A贴合在镜片10的中间层,即镜片10为至少两层结构,光波导10A夹设在相邻的两层之间,这样镜片10对光波导10A具有保护作用,光波导10A本身不需要设置保护层。
一种实施方式中,第一波导基底19S1的折射率大于等于1.6,第一波导基底19S1的厚度小于300um。本方案通过限制第一波导基底19S1的折射率和厚度,使得第一波导基底19S1的设置能够满足光在其中进行全反射传播,具有较好的光学性能的基础上,保证薄型化设计。将第一波导基底19S1的厚度设置在300um以内,再配合第一波导基底19S1的材质的限定,能够提升柔性性能。具体而言,第一波导基底19S1的材料为柔性玻璃或柔性光学树脂材料。
柔性玻璃为厚度小于1mm的玻璃,属于超薄玻璃范畴,柔性玻璃可以为纳钙玻璃、高铝玻璃或低碱玻璃。柔性玻璃是一种能够弯曲、非常柔韧材质,其外层为一层层压塑料,通过这些层压塑料,可以轻松弯折柔性玻璃。
柔性光学树脂材料可以为由高分子有机化合物,例如:丙烯基二甘醇碳酸酯(CR-39)、聚甲基丙烯酸甲酯(PMMA)、聚碳酸酯(PC)。使用柔性光学树脂材料的好处在于:重量轻,柔性光学树脂材料制成的光波导可以为玻璃材料的光波导重量的一半;抗冲击性强,柔性光学树脂材料制成的光波导的抗冲击性比玻璃高10倍;此外,使用柔性光学树脂材料还具有较好的化学稳定性,透光性等等。
第一光栅结构14S1可以为表面浮雕光栅(SRG)、体全息光栅(VHG)。第一光栅结构14S1的类型可以为闪耀光栅、倾斜光栅等等。
图166所示的一种实施方式中,第一光栅结构14S1一体成型在第一波导基底19S1中。例如,第一光 栅结构14S1通过刻蚀工艺形成在第一波导基底19S1的表面。本实施方式提供的光波导10A中,第一光栅结构14S1直接制作在第一波导基底19S1上,不需要额外设置制作光栅的材料层,第一光栅结构14S1和第一波导基底19S1为一体式的结构,结构稳定性更好,易于调制衍射效率,及保持光学性能。
参阅图168,一种实施方式中,所述第一光栅结构14S1形成于第一光栅层19A上,第一光栅层19A和第一波导基底19S1层叠设置,第一波导基底19S1和第一光栅层19A均呈柔性,所述第一光栅层19A材料为压印胶。本实施方式中,第一光栅结构14S1可以通过纳米压印的工艺制作形成。第一光栅层19A的厚度可以为大于等于0.2um小于等于1.2um,所述第一光栅层19A的折射率大于等于1.6。第一光栅层19A的折射率可以与第一波导基底19S1的折射率不同,本方案可以通过折射率不同的设置来调制衍射效率。
图166所示的实施方式和图168所示的实施方式均为单层单面的光波导架构,即光波导只包括一层波导基底(即第一波导基底19S1)和一层光栅结构(即第一光栅结构14S1)。一种实施方式中,本申请还提供一种单层双面的光波导架构,即光波导只包括一层波导基底和两层光栅结构,可以理解为,在第一波导基底的两面均设置光栅结构。
参阅图169,一种实施方式中,第一波导基底19S1包括顶面S11和底面S12,第一光栅结构14S1形成在第一波导基底19S1的顶面S11的一侧,光波导10A还包括第二光栅结构14S2,第二光栅结构14S2形成在第一波导基底19S1的底面S12的一侧。一种实施方式中,第一光栅结构14S1和第二光栅结构14S2可以为相同的结构,例如,第一光栅结构14S1和第二光栅结构14S2均为一种型号的表面浮雕光栅(SRG)。一种实施方式中,第一光栅结构14S1和第二光栅结构14S2可以为不同的结构,例如:第一光栅结构14S1为闪耀光栅,第二光栅结构14S2为倾斜光栅,本申请不限定第一光栅结构14S1和第二光栅结构14S2的具体的光栅类型和光栅结构。第一光栅结构14S1和第二光栅结构14S2的折射率可以相同,也可以不同。
一种实施方式中,第一光栅结构14S1和第二光栅结构14S2均包括耦入光栅,即本方案将耦入光栅分布在第一波导基底19S1的顶面S11和底面S12,能够提升光波导10A的入射光线的耦入范围及衍射效率,可以获得较大的入射光线的FOV。
一种实施方式中,第一光栅结构14S1和第二光栅结构14S2均包括耦出光栅,第一光栅结构14S1所包括的部分耦出光栅的折射率和第二光栅结构14S2所包括的部分耦出光栅的折射率可以不同,通过调节第一波导基底19S1的顶面S11和底面S12的耦出光栅的折射率及相貌(可以理解为光栅的结构形态、周期、矢量方向等参数),可以调制光波导10A的光线耦出效率,可以调制光波导10A耦出光线的带宽等属性。
如图169所示,一种具体的实施方式中,两个矩形虚线方框内的部分光栅结构分别为耦入光栅11和耦出光栅12。在耦入光栅11所在的区域内,第二光栅结构14S2的面积大于第一光栅结构14S1的面积,且第二光栅结构14S2远离耦出光栅12的部分与第一光栅结构14S1重叠,第二光栅结构14S2靠近耦出光栅12的部分所对应的顶面S11上无光栅结构。在耦出光栅12所在的区域内,第一光栅结构14S1的面积大于第二光栅结构14S2的面积,且第一光栅结构14S1远离耦入光栅11的部分与第二光栅结构14S2重叠,第一光栅结构14S1靠近耦入光栅11的所对应的底面上无光栅结构。通过这种光栅配置架构,可以在有限的空间内实现较好的衍射效率,而且有利于保证光线的均匀性。其它实施方式中,本申请不限定第一光栅结构14S1和第二光栅结构14S2之间的面积关系,也不限定二者之间重叠关系,第一光栅结构14S1和第二光栅结构14S2的面积、结构形态、以及位置设置,可以根据具体的设计需求确定。
图169所示的实施方式中,第一光栅结构14S1和第二光栅结构14S2均一体成型于第一波导基底19S1,例如通过刻蚀的方式将第一光栅结构14S1形成在第一波导基底19S1的顶面,及将第二光栅结构14S2形成在第一波导基底19S2的底面。
参阅图170,一种实施方式中,光波导10A包括层叠设置的第一波导基底19S1和第一光栅层19A,第一光栅层19A可以通过旋涂的方式形成在第一波导基底19S1的表面。第一光栅结构14S1通过压印技术形成在第一光栅层19A上,第二光栅结构14S2一体成型于第一波导基底19S1,例如通过刻蚀的方式将第二光栅结构14S2形成在第一波导基底19S2的底面。
参阅图171,一种实施方式中,光波导10A包括依次层叠设置的第一光栅层19A、第一波导基底19S1和第二光栅层19B。第一光栅层19A和第二光栅层19B可以通过旋涂的方式形成在第一波导基底19S1的表面。第一光栅结构14S1通过压印技术形成在第一光栅层19A上,第二光栅结构14S2通过压印技术形成在第二光栅层19B上。第一光栅层19A和第二光栅层19B均可以为压印胶材料。一种实施方式中,第一 光栅层19A和第二光栅层19B的材料可以不同,第一光栅层19A和第二光栅层19B可以具有不同的折射率,且二者的折射率均可以与第一波导基底19S1的折射率不同,通过这样的设置架构,可以用于实现调制光波导的衍射效率,同时可以分别压印不同的光栅形貌,后续可在任意单面增加其他结构,如镀膜覆盖光栅等等,形成非对称结构。
参阅图172A和图172B,一种实施方式中,在图166所示的实施方式和图168所示的实施方式的基础上,所述光波导10A还包括第一调制层19M1,所述第一调制层19M1和所述第一波导基底19S1层叠设置,且部分所述第一调制层19M1填充在所述第一光栅结构14S1中,所述第一调制层19M1的折射率和所述第一光栅结构14S1的折射率之间的差值大于等于0.1。本方案通过在光波导10A的光栅所在的面上增设第一调制层19M1,一方面,第一调制层19M1将第一光栅结构14S1遮盖,第一调制层19M1用于保护第一光栅结构14S1。另一方面第一调制层19M1也能够调制光波导10A的衍射效率,可以使得光波导10A的衍射效率符合使用场景的需求,使光波导10A能够适用较多的场景。
一种实施方式中,第一调制层19M1可以为低折胶水或镀膜结构,第一调制层19M1可以通过旋涂的工艺或电镀的工艺形成在第一波导基底19S1的具有第一光栅结构14S1的表面,或者形成在第一光栅层19A的表面。
一种实施方式中,所述第一调制层的厚度为0.2um至1.2um之间。
一种实施方式中,第一调制层19M1的折射率小于所述第一光栅结构14S1的折射率。具体而言,第一调制层19M1的折射率可以小于等于1.6。本方案主要是为了调节第一光栅结构14S1的衍射效率,因为第一调制层19M1与第一光栅结构14S1有折射率差(折射率差大于等于0.1),所以衍射效率会发生变化,为了保证第一调制层19M1与第一光栅结构14S1之间的折射率差,可以将第一调制层19M1的折射率约束在小于等于1.6的范围内。
一种实施方式中,所述第一调制层19M1的折射率大于所述第一光栅结构14S1的折射率。具体而言,所述第一调制层19M1的折射率大于等于1.9。本方案主要是为了调节第一光栅结构14S1的衍射效率,因为第一调制层19M1与第一光栅结构14S1有折射率差(折射率差大于等于0.1),所以衍射效率会发生变化,为了保证第一调制层19M1与第一光栅结构14S1之间的折射率差,可以将第一调制层19M1的折射率约束在大于等于1.9的范围内。
参阅图173A、图173B和图173C,一种实施方式中,在图169所示的实施方式、图170所示的实施方式和图171所示的实施方式的基础上,所述光波导10A还包括第一调制层19M1和第二调制层19M2。如图173A所示,第一调制层19M1设置在第一波导基底19S1的顶面,且遮盖第一光栅结构14S1,第二调制层19M2设置在第一波导基底19S1的底面,且遮盖第二光栅结构14S2。如图173B所示,第一调制层19M1设置在第一光栅层19A上,且遮盖第一光栅结构14S1,第二调制层19M2设置在第一波导基底19S1的底面,且遮盖第二光栅结构14S2。如图173C所示,第一调制层19M1设置在第一光栅层19A上,且遮盖第一光栅结构14S1,第二调制层19M2设置在第二光栅层19B上,且遮盖第二光栅结构14S2。
参阅图174A和图174B,一种实施方式中,所述第一调制层19M1背离所述第一光栅结构14S1的表面设有第一辅助光栅结构14M1,所述第一辅助光栅结构14M1用于光线的调制。
一种实施方式中,通过第一辅助光栅结构14M1和部分第一光栅结构14S1共同构成光波导10A的耦出光栅,如图174A所示,其中矩形虚线框内的光栅结构代表耦出光栅12。本方案可以理解为,将耦出光栅12分层设置,部分耦出光栅12为第一光栅结构14S1,部分耦出光栅12为第一辅助光栅结构14M1,这两部分耦出光栅12的折射率不同,能够调制耦出光栅12的衍射效率。一种具体的实施方式中,在耦出光栅12所在的区域中,第一辅助光栅结构14M1的折射率小于第一光栅结构14S1的折射率,第一辅助光栅结构14M1位于第一光栅结构14S1的靠近耦入光栅的一侧,即位于第一光栅结构14S1的入光侧,这种设计可以使得耦出光栅12整体耦出光线具有均匀性。其它实施方式中,在耦出光栅12所在的区域中,第一辅助光栅结构14M1的折射率大于第一光栅结构14S1的折射率,通过第一辅助光栅结构14M1能够提升光波导的衍射效率。第一辅助光栅结构14M1可以为耦入光栅、中继光栅或耦出光栅。
参阅图175A、图175B和图175C,一种实施方式中,在图173A、图173B和图173C所示的实施方式的基础上,光波导10A还包括设置在第二调制层上的第二辅助光栅结构14M2。
参阅图175A,光波导10A包括依次层叠设置的第二调制层19M2、第一波导基底19S1和第一调制层19M1,第一调制层19M1和第一波导基底19S1之间设有第一光栅结构14S1,第二调制层19M2和第一波导基底19S1之间设有第二光栅结构14S2,第一调制层19M1背离第一波导基底19S1的表面设有第一辅助 光栅结构14M1,第二调制层19M2背离第一波导基底19S1的表面设有第二辅助光栅结构14M2。第一辅助光栅结构14M1和第二辅助光栅结构14M2可以对称分布在第一波导基底19S1的两侧,第一辅助光栅结构14M1和第二辅助光栅结构14M2可以具有相同的结构、相同的折射率、相同的矢量方向等参数。其它实施方式中,第一辅助光栅结构14M1和第二辅助光栅结构14M2可以具有不同的折射率,或,具有不同的矢量方向,或不同的结构形态。
参阅图175B,光波导10A包括依次层叠设置的第二调制层19M2、第一波导基底19S1、第一光栅层19A和第一调制层19M1,第一光栅层19A上设有第一光栅结构14S1,第一调制层19M1覆盖第一光栅层19A,第一辅助光栅结构14M1设在第一调制层19M1背离第一光栅层19A的表面,第二调制层19M2和第一波导基底19S1之间设有第二光栅结构14S2,第二调制层19M2背离第一波导基底19S1的表面设有第二辅助光栅结构14M2。
参阅图175C,光波导10A包括依次层叠设置的第二调制层19M2、第二光栅层19B、第一波导基底19S1、第一光栅层19A和第一调制层19M1,第一光栅层19A上设有第一光栅结构14S1,第一调制层19M1覆盖第一光栅层19A,第一辅助光栅结构14M1设在第一调制层19M1背离第一光栅层19A的表面。第二光栅层19B上设有第二光栅结构14S1,第二调制层19M2背离第二光栅层19B的表面设有第二辅助光栅结构14M2。
图175A、图175B和图175C所示的实施方式的基础上,第二调制层19M2上也可以不设置光栅结构,即光波导10A可以不设置第二辅助光栅结构14M2。
一种实施方式中,第二调制层19M2的折射率和所述第二光栅结构14S2的折射率之间的差值大于等于0.1。第二调制层19M2的厚度可以为0.2um至1.2um之间。第二调制层19M2的厚度可以与第一调制层19M1的厚度相等。第二调制层M2的厚度可以与第一调制层19M1的厚度不等。
一种实施方式中,本申请提供一种多层单面的光波导,可以理解的是,光波导具有至少两层波导基底,每层波导基底均为单面设置光栅结构。
参阅图176A,一种实施方式中,光波导10A包括第一波导基底19S1和第二波导基底19S2,第一波导基底19S1和第二波导基底19S均呈柔性,能够任意弯曲变形,使得光波导10A为柔性,可以匹配任意弯曲形状的近眼显示设备的镜片。第二波导基底19S2与第一波导基底19S1均用于光路的全反射。第一波导基底19S1的顶面设有第一光栅结构14S1,第一光栅结构14S1的表面设有第一调制层19M1,第一调制层19M1的表面设有第一辅助光栅结构14M1。第二波导基底19S2的顶面设有第三光栅结构14S3。光波导10A还包括光限制层19N,光限制层19N位于第一调制层19M1和第二波导基底19S2的底面之间。光限制层19N呈透明状,用于将隔离第一波导基底19S1和第二波导基底19S2的全反射光路,用于保证所述第一波导基底19S1和所述第二波导基底19S2各自的全反射。光限制层19N亦呈柔性。
一种实施方式中,所述光限制层19N的厚度小于等于100um。本方案将光限制层的厚度控制在小于等于100um,有利于控制光波导10A的薄型化,使光波导10A形成薄膜式架构,与弯曲的镜片表面贴合的过程,能够具有较好的贴合度。
一种实施方式中,光限制层19N的折射率小于等于1.2,光限制层19N可以为低折透明填充胶,可以通过旋涂或沉积的方式形成。
参阅图176B,一种实施方式中,在图176A所示的实施方式的基础上,光波导10A还包括第三调制层19M3,第三调制层19M3覆盖第三光栅结构14S3,用于保护第三光栅结构14S3,及用于调制第三光栅结构14S3的衍射效率。第三调制层19M3的表面还设有第三辅助光栅结构14M3,第三辅助光栅结构14M3用于调制第三光栅结构14S3的衍射效率。
一种实施方式中,光波导为多层波导架构,每层波导架构均为双面光栅结构,即每层波导架构的波导基底的顶面和底面均具有光栅结构。参阅图177,光波导10A包括层叠设置的第一层波导架构10A1、光限制层19N和第二层波导架构10A2。第一层波导架构10A1包括依次层叠设置的第二调制层19M2、第二光栅层19B、第一波导基底19S1、第一光栅层19A和第一调制层19M1。第一光栅层19A上设有第一光栅结构14S1,第一调制层19M1覆盖第一光栅层19A,用于保护第一光栅结构14S1及调制第一光栅结构14S1的衍射效率。第一调制层19M1背离第一光栅层19A的一侧具有第一辅助光栅结构14M1。第一辅助光栅结构14M1用于调制第一光栅结构14S1的衍射效率。第二光栅层19B上设有第二光栅结构14S2,第二调制层19M2覆盖第二光栅层19B,用于保护第二光栅结构14S2及调制第二光栅结构14S2的衍射效率。第二调制层19M2背离第二光栅层19B的一侧具有第二辅助光栅结构14M2。第二辅助光栅结构14M2用于调制第二光栅结构14S2的衍射效率。第二层波导架构10A2包括依次层叠设置的第四调制层19M4、第四 光栅层19E、第二波导基底19S2、第三光栅层19D、第三调制层19M3。第三光栅层19D上具有第三光栅结构14S3,第三调制层19M3覆盖第三光栅层19D,用于保护第三光栅结构14S3及调制第三光栅结构14S3的衍射效率。第三调制层19M3上具有第三辅助光栅结构14M3,第三辅助光栅结构14M3用于调制第三光栅结构14S3的衍射效率。第四光栅层19E上具有第四光栅结构14S4,第四调制层19M4覆盖第四光栅层19E,用于保护第四光栅结构14S4及用于调制第四光栅结构14S4的衍射效率。第四调制层19M4背离第四光栅层19E的表面具有第四辅助光栅结构14M4,第四辅助光栅结构14M4用于调制第四光栅结构14S4的衍射效率。
第四调制层19M4和第一调制层19M1分布在光限制层19N的两侧,且分别贴合于光限制层19N的顶面和底面。第四调制层19M4和第一调制层19M1的折射率均与光限制层19N的折射率形成折射率差,例如,折射率差大于等于0.2或大于等于0.4,通过折射率差的约束,可以保证第一层波导架构10A1和第二层波导架构10A2之间隔离,分别形成独立的全反射路径。
参阅图178A、图178B、图178C,一种实施方式中,光波导10A还包括柔性衬底层19F,柔性衬底层19F和第一波导基底19S1层叠设置,且位于所述第一波导基底19S1的背离所述第一光栅结构14S1的一侧,所述柔性衬底层19F呈透明状且折射率低于所述第一波导基底19S1的折射率,所述柔性衬底层19F用于与近眼显示设备的镜片贴合。本方案通过在第一波导基底19S1上增设一层柔性衬底层19F,通过柔性衬底层19F与镜片贴合,可以避免第一波导基底19S1直接与镜片贴合,若第一波导基底19S1直接与镜片贴合,贴合用的胶水可能会影响第一波导基底19S1的光学参数,柔性衬底层19F能够第一波导基底19S1形成保护,以保证光波导的光学性能。
可以理解的是,其它实施方式中,本申请提供的光波导10A也可以不设置柔性衬底层19F,可以通过第一波导基底19S1直接与近眼显示设备的镜片贴合。
本申请提供一种光波导的制作方法,用于制作前述任意一种实施方式提供的具有柔性的所述的光波导。一种实施方式中,光波导的制作方法包括如下步骤:
提供硬质基底,所述硬质基底包括制作平面;
在所述制作平面上形成一层牺牲层;
在所述牺牲层上制作所述光波导,光波导呈柔性,能够与曲面的近眼显示设备的镜片贴合;
溶解所述牺牲层,得到所述光波导。
本申请提供的光波导的制作方法利用了平面制作工艺,在硬质基底和牺牲层上制作光波导,容易实现批量化的生产。再利用牺牲层的属性,将牺牲层熔解,使得硬质基底脱离,就形成了柔性的光波导。本申请提供的光波导的制作方法,易于加工,制作成本低,能够生产的同时还能保护光波导的柔性性能。特别是可以使用纳米压印工艺大规模制备具有表面浮雕光栅的柔性的光波导。
参阅图179A,一种实施方式中,本申请提供的光波导的制作方法,包括如下步骤:
提供硬质基底19H,硬质基底19H包括制作平面19H1,例如制作平面19H1为硬质基底19H的顶面。
在制作平面19H1上形成牺牲层19X,具体而言,可以通过旋涂工艺或沉积工艺将牺牲层19X的材料设置在制作平面19H1上,确保牺牲层19X的表面是平面状,牺牲层19X的表面需要制作光波导。
在牺牲层19X上制作光波导10A,具体包括:在所述牺牲层19X上设置第一波导基底19S1,在所述第一波导基底19S1上制作第一光栅结构14S1。第一波导基底19S1的折射率大于等于1.6,第一波导基底19S1的厚度小于300um,第一波导基底19S1为柔性材质,脱离硬质基底19H后,能够任意弯曲变形,能够与曲面的近眼显示设备的镜片贴合。
溶解所述牺牲层19X,使得光波导10A和硬质基底19H脱离,便得到了柔性的光波导10A。
通过上述方法可以制作形成单层单面的光波导10A。
一种实施方式中,可以将图179A制成的光波导作为光波导中间结构,继续制作形成单层双面光波导架构,即第一波导基底的两侧均具有光栅结构。
参阅图179B,一种实施方式中,光波导的制作方法包括如下步骤:
提供光波导中间结构10A0,所述光波导中间结构10A0呈柔性,且包括第一波导基底19S1和形成在第一波导基底19S1的表面的第一光栅结构14S1。
提供硬质基底19H,在硬质基底19H上形成牺牲层19X。
将光波导中间结构10A0设置在所述牺牲层19X上,所述第一光栅结构14S1和所述牺牲层19X充分接触;
所述第一波导基底19S1背离所述第一光栅结构14S1的一侧制作第二光栅结构14S2,形成光波导10A。
溶解所述牺牲层19X,使得光波导10A和硬质基底19H脱离,便得到了柔性的光波导10A。
参阅图180A,一种实施方式中,在图179A所示的实施方式提供的光波导的制作方法的基础上,还可以在溶解牺牲层之前继续制作光限制层19N、第二波导基底19S2、第三光栅结构14S3,形成多层光波导架构。具体的方法包括如步骤。
在硬质基板19H上形成牺牲层19X,在牺牲层19X上设置第一波导基底19S1,所述第一波导基底19S1用于光路的全反射,所述第一波导基底19S1呈柔性;
在所述第一波导基底19S1上制作第一光栅结构14S1;
在所述第一光栅结构14S1上形成光限制层19N,所述光限制层19N亦呈柔性且透明状,所述光限制层19N的折射率低于所述第一波导基底19S1的折射率;
在所述光限制层19N上制作第二波导基底19S2,所述第二波导基底19S2用于光路的全反射,所述第二波导基底19S2呈柔性;
在所述第二波导基底19S2上制作第三光栅结构14S3。
具体而言,在图180A所示的实施方式中,第三光栅结构14S3设置在光栅层上,光栅层涂设在第二波导基底19S2的表面。可以理解的是,第三光栅结构14S3也可以通过刻蚀工艺一体成型在第二波导基底19S2上。一种实施方式中,可以在第三光栅结构14S3的表面设置第一调制层19M1,第一调制层19M1的表面可以设置第一辅助光栅结构14M1,第一辅助光栅结构14M1用于调制第三光栅结构14S3的衍射效率。
参阅图180B,一种实施方式中,在图179B所示的实施方式提供的光波导的制作方法的基础上,还可以在溶解牺牲层之前继续制作光限制层19N、第二波导基底19S2、第三光栅结构14S3、第一调制层19M1,形成多层光波导架构。第一调制层19M1的表面可以设置第一辅助光栅结构14M1,第一辅助光栅结构14M1用于调制第三光栅结构14S3的衍射效率。
在本公开的描述中,需要理解的是:
术语“和/或”代表两个方案可以单独存在,也可以同时存在,例如,A和/或B,包括三种方案,第一种方案是A,第二种方案是B,第三种方案包括A和B。
术语“中心”、“纵向”、“横向”、“长度”、“宽度”、“厚度”、“上”、“下”、“前”、“后”、“左”、“右”、“竖直”、“水平”、“顶”、“底”“内”、“外”、“顺时针”、“逆时针”、“轴向”、“径向”、“周向”等指示的方位或位置关系为基于附图所示的方位或位置关系,仅是为了便于描述本公开和简化描述,而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作,因此不能理解为对本公开的限制。
此外,术语“第一”、“第二”仅用于描述目的,而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此,限定有“第一”、“第二”的特征可以明示或者隐含地包括至少一个该特征。在本公开的描述中,“多个”的含义是至少两个,例如两个,三个等,除非另有明确具体的限定。
在本公开中,除非另有明确的规定和限定,术语“安装”、“相连”、“连接”、“固定”等术语应做广义理解,例如,可以是固定连接,也可以是可拆卸连接,或成一体;可以是机械连接,也可以是电连接或彼此可通讯;可以是直接相连,也可以通过中间媒介间接相连,可以是两个元件内部的连通或两个元件的相互作用关系,除非另有明确的限定。对于本领域的普通技术人员而言,可以根据具体情况理解上述术语在本公开中的具体含义。
在本公开中,除非另有明确的规定和限定,第一特征在第二特征“上”或“下”可以是第一和第二特征直接接触,或第一和第二特征通过中间媒介间接接触。而且,第一特征在第二特征“之上”、“上方”和“上面”可是第一特征在第二特征正上方或斜上方,或仅仅表示第一特征水平高度高于第二特征。第一特征在第二特征“之下”、“下方”和“下面”可以是第一特征在第二特征正下方或斜下方,或仅仅表示第一特征水平高度小于第二特征。
在本公开中,术语“一个实施例”、“一些实施例”、“示例”、“具体示例”、或“一些示例”等意指结合该实施例或示例描述的具体特征、结构、材料或者特点包含于本公开的至少一个实施例或示例中。在本说明书中,对上述术语的示意性表述不必须针对的是相同的实施例或示例。而且,描述的具体特征、结构、材料或者特点可以在任一个或多个实施例或示例中以合适的方式结合。此外,在不相互矛盾的情况下,本领域的技术人员可以将本说明书中描述的彼此不同实施例或示例以及彼此不同实施例或示例的特征进行结合和组合。
以上,仅为本申请的具体实施方式,但本申请的保护范围并不局限于此,任何熟悉本技术领域的技术人员在本申请揭露的技术范围内,可轻易想到变化或替换,都应涵盖在本申请的保护范围之内。因此,本申请的保护范围应以权利要求的保护范围为准。

Claims (161)

  1. 一种合光单元,用于近眼显示设备的光机中,其特征在于,所述合光单元包括第一棱镜单元、第二棱镜单元、第三棱镜单元和第四棱镜单元,所述第一棱镜单元和所述第三棱镜单元为五面体结构,所述第二棱镜单元和所述第四棱镜单元为四面体结构,所述第一棱镜单元、所述第二棱镜单元、所述第三棱镜单元和所述第四棱镜单元拼接形成六面体架构,所述第一棱镜单元和所述第二棱镜单元之间对接的位置为第一面,所述第三棱镜单元和所述第四棱镜单元之间的对接位置为第二面,所述第一棱镜单元和所述第四棱镜单元之间对接的位置为第三面,所述第二棱镜单元和所述第三棱镜单元之间的对接位置为第四面,所述第一面和所述第二面设置第一分光膜,所述第三面和所述第四面设置第二分光膜,所述第一分光膜和所述第二分光膜反射的光线的波长范围不同,所述第一面和所述第二面构成所述六面体架构的第一对角面,所述第三面和所述第四面构成所述六面体结构的第二对角面,所述第一对角面和所述第二对角面之间的相交线为所述六面体结构的体对角线。
  2. 如权利要求1所述的合光单元,其特征在于,所述第一棱镜单元、所述第二棱镜单元、所述第三棱镜单元和所述第四棱镜单元均为一体式棱镜结构。
  3. 如权利要求2所述的合光单元,其特征在于,
    所述第一分光膜用于反射第一波长范围的光且透射第二波长范围的光及第三波长范围的光,所述第二分光膜用于反射第二波长范围的光且透射第一波长范围的光及第三波长范围的光;或者,
    所述第一分光膜用于反射第二波长范围的光且透射第一波长范围的光及第三波长范围的光,所述第二分光膜为用于反射第一波长范围的光且透射第二波长范围的光及第三波长范围的光。
  4. 如权利要求1所述的合光单元,其特征在于,
    所述第一棱镜单元包括第一子棱镜和第二子棱镜,所述第一子棱镜和所述第二子棱镜之间对接的位置为第一子面;
    所述第二棱镜单元包括第三子棱镜和第四子棱镜,所述第三子棱镜和所述第四子棱镜之间对接的位置为第二子面;
    所述第三棱镜单元包括第五子棱镜和第六子棱镜,所述第五子棱镜和所述第六子棱镜之间对接的位置为第三子面;
    所述第四棱镜单元包括第七子棱镜和第八子棱镜,所述第七子棱镜和所述第八子棱镜之间对接的位置为第四子面;
    所述第一子面、所述第二子面、所述第三子面和所述第四子面构成所述六面体结构的第三对角面,所述第三对角面和所述第一对角面之间的相交线为所述六面体结构的体对角线,所述第三对角面和所述第二对角面之间的相交线的长度等于所述六面体结构的棱长。
  5. 如权利要求4所述的合光单元,其特征在于,所述第一子棱镜和所述第二子棱镜均为五面体棱镜;所述第三子棱镜和所述第四子棱镜中的一个为四面体棱镜,另一个为五面体棱镜;所述第五子棱镜和所述第六子棱镜均为五面体棱镜;所述第七子棱镜和所述第八子棱镜中的一个为四面体棱镜,另一个为五面体棱镜。
  6. 如权利要求4或5所述的合光单元,其特征在于,所述第三对角面设有第三分光膜,所述第三分光膜、所述第一分光膜和所述第二分光膜分别用于反射不同波长范围的光线。
  7. 如权利要求6所述的合光单元,其特征在于,所述第二分光膜和所述第三分光膜均包括四个子膜,所述第一分光膜为一体式的结构。
  8. 如权利要求1-3任一项所述的合光单元,其特征在于,所述第二分光膜包括两个子膜,所述第一分光膜为一体式的结构。
  9. 一种光机,其特征在于,包括发光单元、光学成像单元和权利要求1-8任一项所述的合光单元,所述合光单元用于将发光单元发出的单色光进行合光,所述光学成像单元位于所述合光单元的出光侧。
  10. 如权利要求9所述的光机,其特征在于,所述发光单元包括第一波长范围发射单元、第二波长范围发射单元和第三波长范围发射单元,所述第一波长范围发射单元正对所述合光单元的所述六面体结构的第一入光面,所述第二波长范围发射单元正对所述合光单元的所述六面体结构的第二入光面,所述第三波长范围发射单元正对所述合光单元的所述六面体结构的第三入光面,所述第一入光面、所述第二入光面和所述第三入光面两两相互垂直相邻设置,所述第一波长范围发射单元的发光面的法线方向和所述第二波长范围发射单元的发光面的法线方向均垂直于所述光机的所述光学成像单元的光轴,所述第三波长范围发射单元的发光面的法线方向与所述光机的所述光学成像单元的光轴方向相同。
  11. 如权利要求9所述的光机,其特征在于,所述发光单元包括第一波长范围发射单元、第二波长范围发射 单元和第三波长范围发射单元,所述第一波长范围发射单元的发光面正对所述合光单元的所述六面体结构的第一入光面,所述第二波长范围发射单元的发光面正对所述合光单元的所述六面体结构的第二入光面,所述第三波长范围发射单元的发光面正对所述合光单元的所述六面体结构的第三入光面,所述第一入光面和所述第二入光面相互平行,所述第三入光面垂直于所述第一入光面,所述第一波长范围发射单元的发光面的法线方向、所述第三波长范围发射单元的发光面的法线方向和所述第二波长范围发射单元的发光面的法线方向均垂直于所述光机的所述光学成像单元的光轴。
  12. 一种近眼显示设备,包括结构件和镜片,所述结构件包括镜腿和镜框,所述镜腿连接于所述镜框,所述镜片具有光波导,所述镜片固定在所述镜框上,其特征在于,所述近眼显示设备包括如权利要求9-11任一项所述的光机,所述光机固定至所述结构件。
  13. 如权利要求12所述的近眼显示设备,其特征在于,所述近眼显示设备设有控制器,所述发光单元包括第一柔性电路板、第二柔性电路板和第三柔性电路板,所述第一柔性电路板电连接在所述第一波长范围发射单元和所述控制器之间,所述第二柔性电路板电连接在所述第二波长范围发射单元和所述控制器之间,所述第三柔性电路板电连接在所述第三波长范围发射单元和所述控制器之间,所述第一柔性电路板、所述第二柔性电路板和所述第三柔性电路板中的至少一个无弯折状地顺着所述结构件延伸。
  14. 如权利要求13所述的近眼显示设备,其特征在于,所述光机固定至所述镜腿,所述第一柔性电路板、所述第二柔性电路板和所述第三柔性电路板中的至少一个无弯折状顺着所述镜腿延伸,所述合光单元的所述六面体结构中的一个外表面为非入光表面,所述非入光表面邻接所述合光单元的出光面,所述非入光表面朝向所述镜腿的内侧,所述镜腿的内侧用于贴近人脸。
  15. 一种光学组件,其特征在于,包括光机和光波导,所述光波导包括波导基底和耦入光栅,所述波导基底包括斜面,所述斜面位于所述耦入光栅和所述波导基底结合的位置或者位于所述耦入光栅和所述波导基底结合位置的入光侧,所述耦入光栅用于接收所述光机的光,所述斜面朝向所述光机,所述光机具有光轴,与所述光轴垂直的方向为第一方向,所述斜面和所述第一方向之间的夹角大于等于所述光机的视场角的二分之一,以使所述耦入光栅反射的所述光机的视场角的边缘光线能够偏出所述光机。
  16. 如权利要求15所述的光学组件,其特征在于,所述光机的视场角为水平面视场角或垂直面视场角。
  17. 如权利要求15或16所述的光学组件,其特征在于,所述光机的光轴为所述光机的有效光学区的中心轴。
  18. 如权利要求15-17任一项所述的光学组件,其特征在于,所述波导基底为一体成型结构,所述斜面为通过在所述波导基底上去除部分材料形成的结构。
  19. 如权利要求18所述的光学组件,其特征在于,所述耦入光栅形成在所述斜面上,经所述耦入光栅反射的光线与所述光轴之间的夹角为第二角度,入射在所述耦入光栅上的所述光机的视场角的边缘光线与所述光轴之间的夹角为第一角度,所述第二角度大于所述第一角度。
  20. 如权利要求18所述的光学组件,其特征在于,所述波导基底包括主平面,所述斜面相对所述主平面倾斜,所述耦入光栅形成在所述主平面上,在所述光轴的延伸方向上,所述斜面位于所述耦入光栅和所述光机之间,所述光机的视场角的边缘光线经过所述斜面入射在所述耦入光栅上,经所述耦入光栅反射的所述光机的视场角的边缘光线经过所述斜面偏出所述光机。
  21. 如权利要求15-17任一项所述的光学组件,其特征在于,所述波导基底包括波导主体结构和附加结构,所述附加结构固定至所述波导主体结构的面对所述光机的表面,所述斜面形成在所述附加结构上,所述斜面位于所述附加结构背离所述波导主体结构的表面。
  22. 如权利要求21所述的光学组件,其特征在于,所述耦入光栅形成在所述斜面上,从所述耦入光栅入射的光线经过所述附加结构后进入所述波导主体结构,经所述耦入光栅反射的光线与所述光轴之间的夹角为第二角度,入射在所述耦入光栅上的所述光机的视场角的边缘光线与所述光轴之间的夹角为第一角度,所述第二角度大于所述第一角度。
  23. 如权利要求21所述的光学组件,其特征在于,所述波导主体结构包括主平面,所述斜面相对所述主平面倾斜,所述耦入光栅形成在所述主平面上,在所述光轴的延伸方向上,所述斜面位于所述耦入光栅和所述光机之间,所述光机的视场角的边缘光线经过所述斜面进入所述附加结构和所述波主导体结构且入射在所述耦入光栅上,经所述耦入光栅反射的所述光机的视场角的边缘光线经过所述波导主体结构和所述附加结构且从所述斜面射出且偏出所述光机。
  24. 如权利要求21-23任一项所述的光学组件,其特征在于,所述附加结构的材料与所述波导主体结构的材料相同;和/或,所述附加结构的折射率与所述波导主体结构的折射率相同。
  25. 如权利要求24所述的光学组件,其特征在于,
    所述附加结构和所述波导主体结构之间通过光学胶水粘合,所述光学胶水的折射率和所述附加结构及所述波导主体结构的折射率相同;或,
    所述附加结构和所述波导主体结构之间通过分子间键合方式结合。
  26. 一种近眼显示设备,其特征在于,包括结构件和权利要求15-25任一项所述光学组件,所述光学组件安装于所述结构件。
  27. 一种光波导,其特征在于,包括耦入光栅和耦出光栅,所述耦入光栅用于将光线耦入所述光波导并在所述光波导内进行全反射,所述耦出光栅用于将光线耦出,所述耦出光栅包括第一区域和第二区域,沿第一方向,所述第一区域位于所述第二区域的入光侧,所述第一区域包括第一子区域和第二子区域,所述第一子区域和所述第二子区域沿第二方向排列,所述第二方向和所述第一方向相交,所述第一子区域和所述第二子区域内的光栅类型均为一维光栅,所述第二区域用于耦出光线,所述第二区域中至少部分光栅的光栅类型为二维光栅,所述第二区域的中轴线的延伸并穿过所述耦入光栅,所述第一子区域和所述第二子区域分布在所述中轴线的两侧。
  28. 如权利要求27所述的光波导,其特征在于,所述第一子区域、所述第二子区域均和所述第二区域接触。
  29. 如权利要求27所述的光波导,其特征在于,所述第一子区域和所述第二区域之间形成第一间隔区域,所述第二子区域和所述第二区域之间形成第二间隔区域,所述第一间隔区和所述第二间隔区内均无光栅结构。
  30. 如权利要求29所述的光波导,其特征在于,所述第一间隔区域沿所述第一方向延伸的尺寸小于等于4毫米,所述第二间隔区域沿所述第一方向延伸的尺寸小于等于4毫米。
  31. 如权利要求27-30任一项所述的光波导,其特征在于,所述耦入光栅的中心位于所述第二区域的中轴线上。
  32. 如权利要求27-31任一项所述的光波导,其特征在于,所述第一子区域和所述第二子区域以所述中轴线为中心呈镜相对称分布;或,所述第一子区域和所述第二子区域的面积不同。
  33. 如权利要求27-31任一项所述的光波导,其特征在于,所述第一子区域的中心和所述第二子区域的中心之间的连线方向为所述第二方向,所述第二方向和所述中轴线之间的夹角小于90度。
  34. 如权利要求27-33任一项所述的光波导,其特征在于,所述第一子区域内的一维光栅的栅线延伸方向为第一栅线方向,所述第二子区域内的一维光栅的栅线延伸方向为第二栅线方向,所述第二区域内的二维光栅包括相交设置的第一栅线和第二栅线,所述第一栅线的延伸方向为所述第一栅线方向,所述第二栅线的延伸方向为第二栅线方向。
  35. 如权利要求34所述的光波导,其特征在于,所述第一子区域内的一维光栅的分布周期与所述第一栅线的分布周期相同;和/或,所述第二子区域内的一维光栅的分布周期与所述第二栅线的分布周期相同。
  36. 如权利要求27-35任一项所述的光波导,其特征在于,所述第一子区域和所述第二子区域接触;或,所述第一子区域和所述第二子区域之间形成第三间隔区域。
  37. 如权利要求36所述的光波导,其特征在于,所述第三间隔区域内无光栅结构,所述第三间隔区域沿所述第二方向延伸的尺寸小于等于耦入光栅的最大径向尺寸。
  38. 如权利要求27-37任一项所述的光波导,其特征在于,所述第二区域内所有的光栅类型均为二维光栅。
  39. 如权利要求27-37任一项所述的光波导,其特征在于,所述第二区域内包括N个二维区和N-1个一维区,N≥2,N-1个所述一维区分别位于相邻的两个所述二维区之间,其中一个所述二维区邻接或邻近所述第一区域,所述一维区内的光栅类型为一维光栅,所述二维区内的光栅类型为二维光栅。
  40. 如权利要求39所述的光波导,其特征在于,所述一维区包括第三子区域和第四子区域,所述第三子区域和所述第四子区域沿所述第二方向排列且分布在所述中轴线的两侧,所述二维区中的部分光栅的栅线方向和所述第三子区域中的光栅的栅线方向相同,所述二维区中的部分光栅的栅线方向和所述第四子区域中的光栅的栅线方向相同。
  41. 一种近眼显示设备,其特征在于,包括光机和权利要求27-40任一项所述光波导,所述光机位于所述耦入光栅的入光侧。
  42. 一种光波导,其特征在于,包括耦出光栅,所述耦出光栅包括多个子光栅相互间隔排布,相邻的两个所述子光栅的间距为L,3mm≦L≦5mm,L指的是相邻的两个所述子光栅的中心之间的距离,其中一个所述子光栅为第一子光栅,所述第一子光栅与邻近所述第一子光栅的其它所述子光栅之间均设有隔开区域,所述第一子光栅的最大径向尺寸小于等于1.5mm,所述隔开区域无光栅结构。
  43. 如权利要求42所述的光波导,其特征在于,所述第一子光栅的最大径向尺寸为D,0.5mm≦D≦1mm。
  44. 如权利要求42所述的光波导,其特征在于,所述多个子光栅中的每一个所述子光栅的最大径向尺寸均为D,0.25mm≦D≦0.75mm;或,0.75mm≦D≦1.5mm。
  45. 如权利要求42-44任一项所述的光波导,其特征在于,所述多个子光栅呈多行多列的阵列排布,所述阵列排布具有相同的行间距和相同的列间距。
  46. 如权利要求42-44任一项所述的光波导,其特征在于,所述多个子光栅排列为多行,各行所述子光栅的排列方向为第一方向,多行所述子光栅中的奇数行和偶数行在错位设置,第二方向垂直于第一方向,在第二方向上,所述奇数行的所述子光栅正对所述偶数行的相邻的两个所述子光栅之间的所述隔开区域。
  47. 如权利要求46所述的光波导,其特征在于,任意两个邻近设置的所述子光栅之间的间距均相等。
  48. 如权利要求42-47任一项所述的光波导,其特征在于,各所述子光栅包括按预设周期排布的光栅微结构,所述预设周期为200-500nm。
  49. 如权利要求42-48任一项所述的耦出光栅,其特征在于,多个所述子光栅共面。
  50. 如权利要求42-48任一项所述的耦出光栅,其特征在于,相邻的两个所述子光栅中的一个位于光波导的波导基底的正面,相邻的两个所述子光栅中的另一个位于所述波导基底的反面,位于所述波导基底的正面的所述子光栅的中心为中心一,位于所述波导基底的反面的所述子光栅的中心在所述波导基底的正面的垂直投影为中心二,所述相邻的两个所述子光栅的间距为所述中心一和所述中心二之间的距离。
  51. 如权利要求42-50任一项所述的光波导,其特征在于,所述光波导包括波导基底、耦入光栅、中继光栅和所述耦出光栅,所述中继光栅位于所述耦入光栅和所述耦出光栅之间,所述耦出光栅包括第一子光栅区域和第二子光栅区域,所述第一子光栅区域距离所述中继光栅的距离小于所述第二子光栅区域距离所述中继光栅的距离,所述第一子光栅区域中的所述子光栅的高度小于所述第二子光栅区域中的所述子光栅的高度。
  52. 如权利要求51所述的光波导,其特征在于,所述耦出光栅包括第一边缘和第二边缘,所述第一边缘为所述耦出光栅邻近所述中继光栅的边缘,所述第二边缘为所述耦出光栅远离所述中继光栅的边缘,从所述第一边缘向所述第二边缘的方向,所述子光栅的高度呈渐变增长趋势。
  53. 一种近眼显示设备,其特征在于,包括光机和如权利要求42-52任一项所述的光波导,所述光波导用于接收所述光机投射的光线。
  54. 一种近眼显示设备,其特征在于,包括光波导、控制单元、瞳孔检测件和光栅调节件,
    所述光波导包括耦出光栅,所述耦出光栅包括多个子光栅,多个所述子光栅阵列排布,各所述子光栅的最大径向尺寸为D,D≦1.5mm,相邻的两个所述子光栅的间距为L’,D≦L’≦4mm,L’指的是相邻的两个所述子光栅的中心之间的距离;
    所述瞳孔检测件用于检测瞳孔的尺寸,所述控制单元用于接收所述瞳孔检测件的信号,并驱动所述光栅调节件,所述光栅调节件用于控制所述耦出光栅的部分所述子光栅开启或关闭,以使部分所述子光栅处于工作状态,在工作状态下的相邻的两个所述子光栅之间的间距为L,3mm≦L≦5mm,L指的是工作状态下的相邻的两个所述子光栅的中心之间的距离。
  55. 一种光波导,其特征在于,包括波导基底和形成在所述波导基底上的光栅结构,所述光栅结构包括多个芯结构和膜结构,所述膜结构的折射率和所述芯结构的折射率不同,多个所述芯结构沿所述光栅结构的矢量方向依次间隔排列,各所述芯结构包括连接端、自由端和侧面,所述连接端连接至所述波导基底,所述自由端和所述连接端在所述芯结构的高度方向上相对设置,所述侧面连接在所述连接端和所述自由端之间,所述膜结构包括膜主体,第一端部和第二端部,所述膜主体包覆所述芯结构的所述侧面,所述第一端部和所述第二端部分别位于所述膜主体的两端,所述第一端部连接所述波导基底,所述第二端部和所述芯结构的所述自由端共面,所有所述芯结构的所述自由端和所述膜结构的所述第二端部共同构成所述光栅结构的端面。
  56. 如权利要求55所述的光波导,其特征在于,所述芯结构的所述自由端的端面和所述膜结构的所述第二端部的端面共面。
  57. 如权利要求55或56所述的光波导,其特征在于,在相邻的所述芯结构之间,所述膜结构包括至少三层膜层,至少三层所述膜层层叠设置在相邻的所述芯结构的所述侧面之间,至少三层所述膜层具有不同的折射率,沿所述光栅结构的矢量方向,至少三层所述膜层的折射率呈正弦分布的渐变趋势。
  58. 如权利要求57所述的光波导,其特征在于,在相邻的所述芯结构之间,所述至少三层膜层具有不同的厚度,
    厚度最大的所述膜层邻接所述芯结构,且所述芯结构的厚度大于厚度最大的所述膜层的厚度;或者,厚度 最小的所述膜层邻接所述芯结构,且所述芯结构的厚度小于厚度最小的所述膜层的厚度。
  59. 如权利要求57或58所述的光波导,其特征在于,其中一层所述膜层包括一一对应交替间隔排布的多层第一子膜和多层第二子膜,所述第一子膜的折射率为N1,所述第二子膜的折射率为N2,所述多层第一子膜和所述多层第二子膜构成的所述膜层的折射率为N,N1<N<N2。
  60. 如权利要求55-59任一项所述的光波导,其特征在于,相邻的所述芯结构之间的部分所述膜结构呈无缝隙结构。
  61. 如权利要求55-59任一项所述的光波导,其特征在于,相邻的所述芯结构之间的所述膜结构的中间位置具有间隙。
  62. 如权利要求55-61所述的光波导,其特征在于,包括耦入光栅,所述耦入光栅包括第一耦入结构和第二耦入结构,所述第一耦入结构和所述第二耦入结构相对设置且分别位于所述波导基底的顶面和底面,所述第一耦入结构和所述第二耦入结构具有不同的光栅倾角;所述光栅结构为至少部分所述耦入光栅。
  63. 如权利要求62所述的光波导,其特征在于,所述第一耦入结构和所述第二耦入结构均为所述光栅结构,所述第一耦入结构的芯结构的折射率高于所述第二耦入结构的芯结构的折射率,所述第一耦入结构的膜结构的折射率高于所述第二耦入结构的膜结构的折射率。
  64. 一种近眼显示设备,其特征在于,包括光机和如权利要求55-63任一项所述的光波导,所述光波导用于接收所述光机投射的光线。
  65. 一种光波导,其特征在于,包括耦入区、耦出区和光线传播区,所述耦入区设有耦入光栅,所述耦入光栅用于接收入射光线,所述入射光线进入所述光波导后在所述光线传播区中全反射,所述耦出区设有耦出光栅,所述耦出光栅用于耦出光线,在所述光线传播区,所述光波导包括介质层和位于介质层两侧的第一光栅层和第二光栅层,所述第一光栅层和所述第二光栅层中的至少一个具有不同周期,所述介质层的折射率小于等于1.5。
  66. 如权利要求65所述的光波导,其特征在于,所述第一光栅层和所述第二光栅层均具有不同周期。
  67. 如权利要求66所述的光波导,其特征在于,所述第一光栅层和所述第二光栅层均为体全息光栅。
  68. 如权利要求65-67任一项所述的光波导,其特征在于,所述光波导还包括中继光栅,在光路传输的方向上,所述中继光栅位于所述耦入区和所述耦出区之间,所述光线传播区中的所述第一光栅层和所述第二光栅层位于所述耦入光栅和所述耦出光栅之间,且包围所述中继光栅。
  69. 如权利要求65-67任一项所述的光波导,其特征在于,所述耦出光栅为二维光栅,所述光线传输区位于所述耦入光栅和所述耦出光栅之间,所述第一光栅层和所述第二光栅层填充所述耦入光栅和所述耦出光栅之间的所有区域。
  70. 如权利要求65-69任一项所述的光波导,其特征在于,所述光波导包括功能区和边缘区,所述功能区内设所述耦入光栅、所述耦出光栅和所述光线传播区中的所述第一光栅层和所述第二光栅层,所述边缘区的折射率小于所述功能区的折射率,或者,所述边缘区的材料和所述功能区的材料不同。
  71. 如权利要求65-69任一项所述的光波导,其特征在于,所述第一光栅层和所述第二光栅层的周期范围为:大于等于100nm且小于等于700nm。
  72. 如权利要求65-71任一项所述的光波导,其特征在于,所述第一光栅层的材料的体积收缩率范围和所述第二光栅层的材料的体积收缩率范围为:小于等于0.1%。
  73. 一种近眼显示设备,其特征在于,包括光机和如权利要求65-72任一项所述的光波导,所述光机发射的光线入射至所述耦入光栅上形成入射光线。
  74. 一种光波导,其特征在于,包括波导基底和增透层,所述增透层形成在所述波导基底的表面,所述增透层包括体全息材料,所述增透层包括折射率不同的高折射率相区和低折射率相区,所述高折射率相区和所述低折射率相区层叠设置在所述波导基底的表面,所述高折射率相区和所述低折射率相区为互相分离的不同区域,所述高折射率相区的折射率范围为:1.5-2.0,所述低折射率相区的折射率范围为1.1-1.5,所述高折射率相区中的组分和所述低折射率相区组分不同。
  75. 如权利要求74所述的光波导,其特征在于,所述高折射率相区的数量为多个,所述低折射率相区的数量为多个,多个所述高折射率相区和多个所述低折射率相区沿垂直于所述波导基底的表面的方向上相间分布。
  76. 如权利要求74或75所述的光波导,其特征在于,所述体全息材料的主体为高分子聚合物材料,所述高分子聚合物材料的主要元素组成包括:C、H、O、N、S、P中的一种或几种或全部。
  77. 如权利要求76所述的光波导,其特征在于,所述体全息材料包括纳米粒子。
  78. 如权利要求77所述的光波导,其特征在于,至少部分所述纳米粒子分布在所述高折射率相区,分布在所述高折射率相区的所述纳米粒子为二氧化钛、二氧化锆、硫化锌、碳量子点中的一种或几种或全部;和/或
    至少部分所述纳米粒子分布在所述低折射率相区,分布在所述低折射率相区的所述纳米粒子为二氧化硅、氟化镁中的一种或全部。
  79. 如权利要求77或78所述的光波导,其特征在于,所述纳米粒子的体积分数含量为0~60%。
  80. 如权利要求74-79任一项所述的光波导,其特征在于,所述高折射率相区和所述低折射率相区的数量均为多层,且依次间隔层叠设置在所述波导基底表面。
  81. 如权利要求80所述的光波导,其特征在于,各所述高折射率相区的厚度或各所述低折射率相区的厚度范围为:100nm~1000nm。
  82. 如权利要求74-81任一项所述的光波导,其特征在于,所述光波导还包括耦入光栅和耦出光栅,所述耦入光栅和所述耦出光栅均形成在所述波导基底的表面,所述波导基底的表面设有非光栅区,所述非光栅区为所述耦入光栅和所述耦入光栅之外的区域,至少部分所述增透层位于所述非光栅区。
  83. 如权利要求74-81任一项所述的光波导,其特征在于,所述光波导还包括耦入光栅、中继光栅和耦出光栅,所述耦入光栅、所述中继光栅和所述耦出光栅形成在所述波导基底的表面,所述波导基底的表面设有非光栅区,所述非光栅区为所述耦入光栅、所述中继光栅和所述耦出光栅之外的区域,至少部分所述增透层位于所述非光栅区。
  84. 如权利要求82或83所述的光波导,其特征在于,部分所述增透层位于所述耦出光栅所在的位置且和所述耦出光栅形成共体结构,所述共体结构包括沿所述耦出光栅的矢量方向排列的光栅微结构,所述共体结构还包括沿所述光波导的法线方向相间分布的所述高折射率相区和所述低折射率相区。
  85. 如权利要求84所述的光波导,其特征在于,所述耦出光栅与所述波导基底的连接的面为所述耦出光栅的耦出底面,所述耦出光栅背离所述波导基底的面为所述耦出光栅的耦出顶面,和所述耦出光栅形成所述共体结构的部分所述增透层形成在所述耦出底面和所述耦出顶面之间。
  86. 一种近眼显示设备,其特征在于,包括光机和权利要求74-85任一项所述的光波导,所述光机位于所述光波导的入光侧。
  87. 一种光波导,应用于近眼显示设备,其特征在于,所述光波导包括第一波导基底、第一光栅结构和第一填充层,所述第一光栅结构形成于所述光第一波导基底的表面,所述第一填充层和所述第一波导基底层叠设置,且所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2。
  88. 如权利要求87所述的光波导,其特征在于,所述第一填充层包括光栅接触面,所述光栅接触面具有与所述第一光栅结构相同的周期性排列的微结构,以使得所述第一填充层的所述光栅接触面和所述第一光栅结构的微结构的表面贴合。
  89. 如权利要求87所述的光波导,其特征在于,所述第一填充层包括光栅接触面,所述光栅接触面为平面状,所述第一填充层和所述第一光栅结构之间具有周期性排列的狭缝。
  90. 如权利要求87-89任一项所述的光波导,其特征在于,所述第一填充层满足如下条件中的一种或多种的组合:
    所述第一填充层的透光性大于等于80%;
    所述第一填充层的厚度小于等于1000um;
    所述第一填充层的材料包括气凝胶材料、树脂材料、无机材料、有机材料中的任意一种或多种的组合;
    所述第一填充层的材料为二氧化硅气凝胶。
  91. 如权利要求87-90任一项所述的光波导,其特征在于,所述光波导还包括第一盖板,所述第一盖板和所述第一波导基底固定连接,所述第一填充层层叠设置在所述第一盖板和所述第一波导基底之间,所述第一填充层和所述第一盖板贴合。
  92. 如权利要求91所述的光波导,其特征在于,所述第一盖板和所述第一波导基底之间通过点胶结构固定连接,所述点胶结构分布在所述第一填充层的周围。
  93. 如权利要求91或92所述的光波导,其特征在于,所述光波导还包括第二光栅结构、第二填充层和第二盖板,所述第二光栅结构和所述第一光栅结构分布在所述第一波导基底相对的两侧,所述第二填充层和所述第一波导基底层叠设置,且所述第二填充层和所述第一光波基底共同封闭包围所述第二光栅结构,所述 第二填充层的折射率和空气的折射率之间的差值小于等于0.2,所述第二盖板和所述第一波导基底固定连接,所述第二填充层层叠设置在所述第二盖板和所述第一波导基底之间,所述第二填充层和所述第二盖板贴合。
  94. 如权利要求87-93任一项所述的光波导,其特征在于,所述光波导还包括第二波导基底和第三光栅结构,所述第三光栅结构形成在所述第二波导基底上,所述第二波导基底和所述第一波导基底层叠设置,所述第二波导基底和所述第一光波导基底之间设有第三填充层,所述第三填充层的折射率和空气的折射率之间的差值小于等于0.2。
  95. 如权利要求87-93任一项所述的光波导,其特征在于,所述光波导还包括至少两个第二波导基底,各所述第二波导基底上均设有第三光栅结构,至少两个所述第二波导基底层叠设置在所述第一波导基底背离所述第一填充层的一侧,所述第二波导基底和所述第一波导基底之间,以及相邻的所述第二波导基底之间均设有第三填充层,所述第三填充层和所述第二波导基底共同包围所述第三光栅结构,所述第三填充层的折射率和空气的折射率之间的差值小于等于0.2。
  96. 如权利要求87-90任一项所述的光波导,其特征在于,所述光波导还包括第二波导基底,所述第二波导基底和所述第一波导基底层叠设置,所述第二波导基底的表面设有第三光栅结构,所述第三光栅结构和所述第一光栅结构相对设置,所述第一填充层填充在所述第一波导基底和所述第二波导基底之间,所述第一填充层覆盖第二波导基底和第三光栅结构。
  97. 一种光波导,其特征在于,包括第一波导基底、第一光栅结构、波导填充结构、第三光栅结构和第一填充层,所述第一光栅结构形成在所述第一波导基底的表面,所述波导填充结构包裹所述第一光栅结构且覆盖所述第一波导基底,所述第三光栅结构形成在所述波导填充结构背离所述第一波导基底的表面,所述第一填充层覆盖所述波导填充结构,所述第一填充层和所述波导填充结构共同形成封闭的包围架构,所述第三光栅结构位于所述包围架构内,以使所述第三光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2。
  98. 如权利要求97所述的光波导,其特征在于,所述波导填充结构的折射率和所述第一波导基底的折射率之间的差值在0-0.5之间。
  99. 如权利要求97或98所述的光波导,其特征在于,所述光波导还包括第一盖板,所述第一盖板位于所述第一填充层背离所述波导填充结构的一侧。
  100. 如权利要求99所述的光波导,其特征在于,所述波导填充结构的边缘相较第一波导基底内缩,以在第一波导基底的边缘预留位置用于设置点胶结构,所述点胶结构固定连接所述第一盖板和所述第一波导基底。
  101. 一种近眼显示设备,其特征在于,包括光机和如权利要求87-100任一项所述的光波导,所述光波导位于所述光机的出光侧。
  102. 一种光波导的制作方法,其特征在于,包括:
    提供第一盖板,在所述第一盖板上涂设第一填充材料,以在第一盖板上形成第一填充层;
    提供第一波导基底,所述第一波导基底上设有第一光栅结构;
    对位所述第一盖板和所述第一波导基底,使得所述第一填充层和所述第一波导基底结合且共同封闭包围所述第一光栅结构;
    固定所述第一盖板和所述第一波导基底,以使所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2。
  103. 一种光波导的制作方法,其特征在于,包括:
    提供第一波导基底,所述第一波导基底上设有第一光栅结构;
    提供硬质母模,所述硬质母模上具有光栅模结构,所述光栅模结构与所述第一光栅结构形态相同;
    对所述硬质母模承载所述光栅模结构的表面及所述光栅模结构的表面进行疏水处理;
    在所述硬质母模上涂设第一填充材料,以形成第一填充层;
    将第一盖板贴设在所述第一填充层上,使得所述第一盖板和所述第一填充层结合为一体;
    脱模,使得所述第一盖板和所述第一填充层与所述硬质母模脱离;
    对位所述第一盖板和所述第一波导基底,以使所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2;
    固定所述第一盖板和所述第一波导基底。
  104. 一种光波导的制作方法,其特征在于,包括:
    提供一种光波导中间结构,所述光波导中间结构包括第一波导基底、第一光栅结构和第一盖板,所述第一光栅结构形成在所述第一波导基底的表面,所述第一盖板和所述第一波导基底层叠设置且固定连接,所述第一盖板和所述第一波导基底之间及所述第一盖板和所述第一光栅结构之间形成间隙;
    在所述第一盖板上设注入孔;
    通过所述注入孔注入填充材料,以形成第一填充,所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2。
  105. 一种光波导的制作方法,其特征在于,包括:
    提供第一波导基底,所述第一波导基底上设有第一光栅结构;
    将填充材料涂覆至所述第一波导基底的表面和所述第一光栅结构的表面,形成第一填充层,所述第一填充层和所述第一波导基底共同形成封闭的包围架构,所述第一光栅结构位于所述包围架构内,以使所述第一光栅结构与外界空气隔离,所述第一填充层的折射率和空气的折射率之间的差值小于等于0.2;
    在所述第一填充层的边缘,且在所述第一波导基底的表面设置点胶结构;
    将第一盖板固定至所述点胶结构,使得所述第一盖板和所述第一波导结构固定连接。
  106. 一种光波导,其特征在于,包括波导基底和光栅结构,所述光栅结构和所述波导基底结合,所述波导基底包括第一基材层和第二基材层,所述第一基材层的折射率低于所述第二基材层的折射率,所述第二基材层的折射率和所述第一基材层的折射率的差值大于等于0.1,所述第二基材层的厚度介于50微米至300微米之间;所述光栅结构位于所述第二基材层背离所述第一基材层的一侧,和/或,所述光栅结构位于所述第一基材层和所述第二基材层之间。
  107. 如权利要求106所述的光波导,其特征在于,所述第一基材层的材料为玻璃,且所述第一基材层的折射率小于等于1.55。
  108. 如权利要求106或107所述的光波导,其特征在于,所述第二基材层的折射率大于等于1.65。
  109. 如权利要求106-108任一项所述的光波导,其特征在于,所述第一基材层用于在制作所述第二基材层过程中承载形成所述第二基材层的材料,所述第二基材层通过制作工艺和所述第一基材层结合为一体成型的结构。
  110. 如权利要求106-109任一项所述的光波导,其特征在于,所述第一基材层的表面通过刻蚀工艺形成沟槽状的微结构,所述第二基材层形成在所述第一基材层的表面且与所述沟槽状的微结构结合,以形成至少部分所述光栅结构。
  111. 如权利要求106-110任一项所述的光波导,其特征在于,所述波导基底的厚度小于0.35mm。
  112. 如权利要求106-111任一项所述的光波导,其特征在于,所述第二基材层背离所述第一基材层的一侧设有保护层。
  113. 如权利要求106-112任一项所述的光波导,其特征在于,所述光波导包括功能区和边缘区,所述边缘区包围所述功能区,所述波导基底和所述光栅结构位于所述功能区,所述边缘区设波导边缘主体,所述波导边缘主体和所述波导基底的边缘结合,所述波导边缘主体具透光性,且所述波导边缘主体的密度小于所述第一波导基底材料的密度。
  114. 如权利要求106-113任一项所述的光波导,其特征在于,所述光波导还包括包裹层,所述包裹层全包裹或半包裹所述波导基底和所述光栅结构,所述包裹层的外表面包括第一表面,所述第一表面为曲面,以矫正不同的近视度数。
  115. 一种近眼显示设备,其特征在于,包括光机和如权利要求106-114任一项所述的光波导,所述光波导位于所述光机的出光侧。
  116. 一种光波导的制作方法,其特征在于,包括:
    在基底层上制作第一光栅层,所述第一光栅层具有第一光栅结构;
    通过光栅结构模板制作第二光栅层,将所述第二光栅层制作在所述第一光栅层背离所述基底层的一侧,所述第二光栅层具有第二光栅结构,在所述第一光栅层和所述第二光栅层之间设置增粘层;
    脱模所述光栅结构模板,以使所述基底层、所述第一光栅层、所述增粘层和所述第二光栅层结合为一体构成光波导。
  117. 根据权利要求116所述的制作方法,其特征在于,通过所述光栅结构模板制作所述第二光栅层的步骤包括:
    在所述第一光栅层上制作介质层;
    在所述介质层上涂覆所述增粘层;
    在所述增粘层上涂覆第二压印材料层;
    通过所述光栅结构模板在所述第二压印材料层上制作所述第二光栅结构,以形成所述第二光栅层。
  118. 根据权利要求117所述的制作方法,其特征在于,通过所述光栅结构模板制作所述第二光栅层的步骤之前,所述制作方法包括:对所述光栅结构模板的工作表面做抗粘处理,通过所述光栅结构模板在所述第二压印材料层上制作所述第二光栅层的过程中,所述工作表面和所述第二压印材料层接触。
  119. 根据权利要求117或118所述的制作方法,其特征在于,在所述第一光栅层上制作介质层的步骤包括:通过镀膜工艺将所述介质层形成在所述第一光栅层上。
  120. 如权利要求119所述的制作方法,其特征在于,所述介质层的材料包括氧化物或氮化物;和/或,所述介质层的折射率在1.8~2.3之间。
  121. 如权利要求119所述的制作方法,其特征在于,在所述第一光栅层上制作介质层的步骤还包括:通过化学机械研磨工艺对所述介质层进度表面处理。
  122. 如权利要求117-121任一项所述的制作方法,其特征在于,所述第二压印材料层的折射率在1.6~1.9之间,和/或,所述第二压印材料层厚度在100~400nm之间。
  123. 根据权利要求116-122任一项所述的制作方法,其特征在于,通过所述光栅结构模板制作所述第二光栅层的步骤包括:
    提供所述光栅结构模板;
    在所述光栅结构模板上制作所述第二光栅层;
    通过所述增粘层将连接所述光栅结构模板的所述第二光栅层粘接在所述第一光栅层上。
  124. 根据权利要求123所述的制作方法,其特征在于,通过所述光栅结构模板制作所述第二光栅层的步骤包括:先在所述第二光栅层背离所述光栅结构模板的表面涂覆所述增粘层,再将所述第一光栅层粘贴在所述增粘层上。
  125. 根据权利要求123或124所述的制作方法,其特征在于,所述制作方法还包括,在所述第一光栅层上制作介质层,通过所述增粘层将连接所述光栅结构模板的所述第二光栅层粘接在所述介质层上。
  126. 根据权利要求125所述的制作方法,其特征在于,所述介质层的表面形态与所述第一光栅层的表面形态相同。
  127. 根据权利要求123或124所述的制作方法,其特征在于,通过所述增粘层将连接所述光栅结构模板的所述第二光栅层粘接在所述第一光栅层上的过程中,所述增粘层和所述第一光栅层直接接触。
  128. 根据权利要求122-127任一项所述的制作方法,其特征在于,在所述光栅结构模板上制作第二光栅层的步骤之前,对所述光栅结构模板的工作表面做抗粘处理,在所述光栅结构模板上制作第二光栅层的过程中,在所述工作表面上制作所述第二光栅层。
  129. 根据权利要求122-128任一项所述的制作方法,其特征在于,在所述基底层上制作所述第一光栅层的步骤包括:在所述基底层上涂覆第一压印材料层,通过纳米压印工艺在所述第一压印材料层上形成所述第一光栅层,形成所述第一光栅层的过程中所述第一压印材料承受的力为第一压力,通过所述增粘层将连接所述光栅结构模板的所述第二光栅层粘接在所述第一光栅层上的过程中,所述第一光栅层和所述第二光栅层承受的力为第二压力,所述第二压力小于等于所述第一压力。
  130. 一种光波导,其特征在于,包括:
    基底层;
    第一光栅层,与所述基底层层叠设置,所述第一光栅层具有第一光栅结构;
    第二光栅层,层叠设置在所述第一光栅层背离所述基底层的一侧,所述第二光栅层具有第二光栅结构;
    在所述第一光栅层和所述第二光栅层之间具有增粘层。
  131. 一种近眼显示设备,其特征在于,包括光机和如权利要求130所述的光波导,所述光波导位于所述光机的出光侧。
  132. 一种光波导,应用于近眼显示设备,其特征在于,所述光波导包括依次层叠设置光波导主体、第一减反层、填充主体层、第二减反层和表面保护层,所述第一减反层位于在所述光波导主体和所述填充主体层之间,所述填充主体层的折射率和空气的折射率之间的差在第一预设范围内,所述第二减反层位于所述填充主体层和所述表面保护层之间,所述第二减反层的折射率呈渐变趋势变化,所述第二减反层与所述填充主体层邻近的部分的折射率和所述填充主体层之间的折射率差在第二预设范围内,所述第二减反层与所述 表面保护层邻近的部分的折射率和所述表面保护层之间的折射率差在第三预设范围内。
  133. 根据权利要求132所述的光波导,其特征在于,所述光波导满足如下条件中的任一项或多项的组合:
    所述第一预设范围为小于等于0.25的范围;
    所述第二预设范围为小于等于0.1的范围;
    所述第三预设范围为小于等于0.1的范围。
  134. 根据权利要求132或133所述的光波导,其特征在于,所述填充主体层的折射率和空气的折射率之间的差在0.1~0.25之间,和/或,所述填充主体层的厚度在30~50μm之间。
  135. 根据权利要求132-134任一项所述的光波导,其特征在于,所述填充主体层包括基底和折光介质,所述折光介质分散在所述基底内。
  136. 根据权利要求135所述的光波导,其特征在于,所述树脂颗粒为内部空心结构。
  137. 根据权利要求132-134任一项所述的光波导,其特征在于,所述填充主体层为气凝胶。
  138. 根据权利要求132-137任一项所述的光波导,其特征在于,所述第二减反层包括多个层叠设置的第二减反子层,任意相邻两层所述第二减反子层的折射率之间的差在预设范围内。
  139. 根据权利要求138所述的光波导,其特征在于,自所述光波导主体至所述表面保护层的方向上,多个所述第二减反子层的折射率沿梯度递增。
  140. 根据权利要求138或139所述的光波导,其特征在于,所述第二减反层和所述填充主体层的材料相同,密度不同;和/或,所述第二减反层和所述填充主体层通过同样的制作工艺形成。
  141. 根据权利要求132-140任一项所述的光波导,其特征在于,所述第一减反层通过镀膜的方式形成在所述光波导主体的表面。
  142. 一种近眼显示设备,其特征在于,包括如权利要求132-141任一项所述的光波导。
  143. 一种光波导的制备方法,其特征在于,包括:
    在光波导主体上制作第一减反层,使得所述第一减反层和所述光波导主体叠设置;
    在所述第一减反层背离所述光波导主体的一侧制作填充主体层;
    在所述填充主体层背离所述第一减反层的一侧制作第二减反层,所述第二减反层的折射率呈渐变趋势变化;
    在所述第二减反层背离所述填充主体层的一侧制作表面保护层。
  144. 根据权利要求143所述的制备方法,其特征在于,在所述填充主体层背离所述第一减反层的一侧制作第二减反层的步骤包括:
    在所述填充主体层背离所述第一减反层的一侧制作多个层叠设置的第二减反子层,自所述光波导主体至所述表面保护层的方向上,多个所述第二减反子层的折射率沿梯度递增。
  145. 根据权利要求144所述的制备方法,其特征在于,在所述填充主体层背离所述第一减反层的一侧制作多个层叠设置的第二减反子层的步骤包括:
    在基底材料中加入折光介质,并均匀混合得到填充主体材料;
    将所述填充主体材料和所述基底材料按预设比例混合后得到多组第二减反材料,多组所述第二减反材料的折射率不同;
    在所述填充主体层上依次涂覆并固化多组所述第二减反材料,得到多个层叠设置的所述第二减反子层。
  146. 根据权利要求144所述的制备方法,其特征在于,在所述填充主体层背离所述第一减反层的一侧制作多个层叠设置的第二减反子层的步骤包括:
    在溶剂中加入硅源材料,得到多组第二减反材料,多组所述第二减反材料中所述硅源材料和所述溶剂的体积比不同;
    在所述填充主体层上依次涂覆并固化多组所述第二减反材料,得到多个层叠设置的所述第二减反子层。
  147. 一种光波导,应用于近眼显示设备,其特征在于,包括第一波导基底和形成在所述第一波导基底的表面的第一光栅结构,所述第一波导基底用于光路的全反射,所述第一波导基底和所述第一光栅结构均呈柔性,所述光波导具有变形特性,以使得所述光波导能够适配所述近眼显示设备的不同曲率的镜片。
  148. 如权利要求147所述的光波导,其特征在于,所述第一波导基底的折射率大于等于1.6,所述第一波导基底的厚度小于300um。
  149. 如权利要求147所述的光波导,其特征在于,所述第一波导基底的材料为柔性玻璃或柔性光学树脂材料。
  150. 如权利要求147-149任一项所述的光波导,其特征在于,所述第一光栅结构一体成型在所述第一波导基底中。
  151. 如权利要求147-150任一项所述的光波导,其特征在于,所述光波导还包括第一调制层,所述第一调制层和所述第一波导基底层叠设置,且部分所述第一调制层填充在所述第一光栅结构中,所述第一调制层的折射率和所述第一光栅结构折射率之间的差值大于等于0.1。
  152. 如权利要求151所述的光波导,其特征在于,所述第一调制层的折射率小于所述第一光栅结构的折射率;或,所述第一调制层的折射率大于所述第一光栅结构的折射率。
  153. 如权利要求151或152所述的光波导,其特征在于,所述第一调制层背离所述第一光栅结构的表面设有第一辅助光栅结构,所述第一辅助光栅结构用于光线的调制。
  154. 如权利要求147-153任一项所述的光波导,其特征在于,所述光波导还包括第二光栅结构,所述第一光栅结构和所述第二光栅结构分别位于所述第一波导基底相对的两侧。
  155. 如权利要求147-154任一项所述的光波导,其特征在于,所述光波导还包括第二波导基底、光限制层和第三光栅结构,所述第二波导基底用于光路的全反射,所述第二波导基底呈柔性,所述光限制层层叠设置在所述第一波导基底和所述第二波导基底之间,所述光限制层亦呈柔性且透明状,所述光限制层的折射率低于所述第一波导基底的折射率,也低于所述第二波导基底的折射率,所述光限制层用于保证所述第一波导基底和所述第二波导基底各自的全反射,所述第三光栅结构形成在所述第二波导基底上。
  156. 如权利要求147-155任一项所述的光波导,其特征在于,所述光波导还包括柔性衬底层,所述柔性衬底层和所述第一波导基底层叠设置,且位于所述第一波导基底的背离所述第一光栅结构的一侧,所述柔性衬底层呈透明状且折射率低于所述第一波导基底的折射率,所述柔性衬底层用于与所述近眼显示设备的镜片贴合。
  157. 一种光波导的制作方法,用于制作权利要求147-156任一项所述的光波导,其特征在于,所述制作方法包括:
    提供硬质基底,所述硬质基底包括制作平面;
    在所述制作平面上形成一层牺牲层;
    在所述牺牲层上制作所述光波导;
    溶解所述牺牲层,得到所述光波导。
  158. 如权利要求157所述的光波导的制作方法,其特征在于,在所述牺牲层上制作所述光波导的步骤包括:
    在所述牺牲层上设置第一波导基底,所述第一波导基底的折射率大于等于1.6,所述第一波导基底的厚度小于300um;
    在所述第一波导基底上制作第一光栅结构。
  159. 如权利要求157所述的光波导的制作方法,其特征在于,在所述牺牲层上制作光波导的步骤包括:
    提供光波导中间结构,所述光波导中间结构呈柔性,且包括第一波导基底和形成在第一波导基底的表面的第一光栅结构;
    将所述光波导中间结构设置在所述牺牲层上,所述第一光栅结构和所述牺牲层充分接触;
    在所述第一波导基底背离所述第一光栅结构的一侧制作第二光栅结构。
  160. 如权利要求157所述的光波导的制作方法,其特征在于,在所述牺牲层上制作光波导的步骤包括:
    在所述牺牲层上设置第一波导基底,所述第一波导基底用于光路的全反射,所述第一波导基底呈柔性;
    在所述第一波导基底上制作第一光栅结构;
    在所述第一光栅结构上形成光限制层,所述光限制层亦呈柔性且透明状,所述光限制层的折射率低于所述第一波导基底的折射率;
    在所述光限制层上制作第二波导基底,所述第二波导基底用于光路的全反射,所述第二波导基底呈柔性;
    在所述第二波导基底上制作第三光栅结构。
  161. 一种近眼显示设备,其特征在于,包括镜片和如权利要求147-156任一项所述的光波导,所述镜片包括曲面部分,所述光波导贴合至所述镜片的所述曲面部分的表层或中间层。
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