JPH1068803A - Film with reduced scattering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change the emission angle profile of light from a light source and to obtain brighter light with same power consumption by forming a first surface facing the light source, the optical axis perpendicular to the film and a second surface having lots of shapes. SOLUTION: This device 50 has an almost flat first surface 52 and a second surface comprising plural numbers of pyramid-like bodies 54 having irregular polygonal bottoms. The device 50 is generally disposed between a light source for illumination and an image source (such as an LCD). The light emitting from the light source enters the flat first surface 52. The shapes and dimensions of bodies 54 on the second surface are selected in such a manner that the light entering the film within a desired observation angle range is transmitted but the light out of this observation angle range is completely reflected in the inside and returned to the light source. Each body 54 is formed in such a manner that almost all of incident light beams on the second surface of the body show a first incident angle and a second incident angle different from each other. Therefore, the light out of the desired observation angle range of the film is reflected so that a brighter image can be obtd. with same quantity of light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film for changing an angular emission profile of light emitted from a light source, and in particular, to a viewing angle.
e) For a film that totally internally reflects light incident on the film outside the range.

[0002]

BACKGROUND OF THE INVENTION Devices, such as films, that modify the light emission profile have many useful applications. One application is to modify the light sent to a liquid crystal display (LCD). LCDs are optical devices that are widely used in applications such as thermostat displays, gas pump displays, portable computers, and TV displays, but have problems of high power consumption and low illuminance. LCDs are classified according to the type of display illumination source. A "reflective" or "passive" display illuminates with ambient light incident on the display from the viewer side, and generally has a reflector on the LCD opposite the viewer. This reflector changes the ambient light to L
Returning to a CD to illuminate the LCD, this type of display can only be used satisfactorily where there is sufficient ambient light to be reflected. Also, full color or color displays made in this manner cannot be viewed outdoors because the reflected light to illuminate the display is generally insufficient.

[0003] A "backlight" type display is one in which the reflector of a passive display is replaced by an optical space containing lamps and other illumination sources. This display provides better illumination for the LCD, but at the cost of shorter battery life. The reason is the backlight L
CD is because it generally uses an illumination source having a Lambertian emission profile. In this Lambert illumination, the brightness is constant in all directions, but the LCD shows acceptable performance only in a very narrow viewing angle range, and brightness outside this range is wasted. That is, only a small portion of the battery energy is used to generate light within a narrow viewing angle range, and the light generated by the remaining majority of the battery energy is unusable and wasted.

Attempts to solve this problem have created yet another problem. FIG. 1 is an example of an attempt to solve the problem of light transmission outside the desired observation angle range, and shows a perspective view of a film having grooves on the surface. In this FIG.
Gain is limited due to increased side lobe scattering of the grooved surface 10 of the device. In other words, a significant amount of the transmitted light of this device is transmitted at angles outside the desired viewing angle range. The maximum effective viewing angle of this device is 104 ° x
70 ° full width at halfmaximum
And the theoretical gain is limited to 200%. The reason will be described below with reference to FIGS. 1, 2A, 2B, 3A, 3B, 4A, and 4B.

[0005] The light beam 12 has a triangular surface protrusion 10 at a first point of incidence.
Incident on. If this ray 12 is not transmitted, ray 12
Is reflected and enters the surface protrusion at the second incidence point. Light rays
The angle at which 12 strikes the triangular surface protrusion 10 is measured in a plane perpendicular to one of the three dimensional axes of the film and containing the point of incidence. For example, FIG. 2A
A first plane 14 perpendicular to the first of the three dimensional axes of the film includes a first point of incidence and a triangular surface projection.
The angle of incidence of the light beam 12 on 10 is measured in this plane. Similarly, if the ray 12 is reflected and is incident at the second point of incidence 16, the plane perpendicular to the same axis as above and containing the second point of incidence defines the plane at which the second angle of incidence is to be measured. . FIG. 2B is a plane
FIG. 3 shows the projection of the ray 12 onto 14 and 16 and shows the angle of incidence measured at these planes when the ray 12 is incident on the triangular surface protrusion 10. FIG. 2B shows that on the first axis, the first and second angles of incidence of the light beam 12 are equal.

As shown in FIGS. 2A and 2B, FIGS. 3A and 3B
3A and FIG. 3B show the light beam 12 incident on the triangular surface protrusion 10, but the light beam 12 is incident on the first incident point in FIGS.
The angle of incidence is measured at a first plane 18 perpendicular to the second of the three dimensional axes of the film and including a second point of incidence. Similarly, the second point of incidence is in a plane perpendicular to the second of the three dimensional axes of the film. In this embodiment, the second plane is plane 18. FIG. 3B shows the plane 18 of the ray 12.
The projection line above and the projection line of the first normal to the plane 18 at the first point of incidence on the plane 18 and the normal to the plane 18 at the second point of incidence are shown. Has a triangular surface protrusion
The angle of incidence of the ray 12 on 10 is the projection line 22 on the first normal and the ray 12
And the angle between the projection line 24 of the second normal surface and the projection line of the light ray 12. These two angles are different from each other as shown in FIG. 3B.

FIG. 4A shows a light beam 12 incident on a triangular surface protrusion 10, again in which the light beam 12 is incident at a first point of incidence and a second point of incidence. Each incident point is on the first plane 26 and on the second plane 28, respectively. FIG. 4B shows the projected lines of the light beam 12 on the first plane 26 and the second plane 28,
And the second angles of incidence are equal to each other.
In the above known film, substantially all of the light incident on the film has the same first and second angles of incidence with respect to two of the three dimensional axes (FIGS. 2B and 4B) including the optical axis (FIG. 4B). have. This symmetry results in higher sidelobe emission, more light emitted outside the preferred viewing angle range, and lower illuminance.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a film having low sidelobe radiation. When the film of the present invention is used, light outside the desired observation angle range is completely reflected inside, so that the display becomes bright and power consumption is reduced. Light that is completely internally reflected is then re-reflected toward the film, at least a portion of which is incident within the desired viewing angle range, producing brighter light with the same power consumption.

[0009] The film of the present invention is a non-imaging film that is placed between a light source and an image source to change the emission angular profile of light emitted from the light source. Light incident on the film within the desired viewing angle range is transmitted, and light outside the desired viewing angle range is completely internally reflected.

[0010]

SUMMARY OF THE INVENTION In one aspect, the present invention is directed to a film that changes the angular emission profile of light emitted from a light source. The film has a first surface facing the light source, an optical axis perpendicular to the film, and a second surface having a number of shapes. Each feature on the second surface of the film has a first face and a second face, and light rays emanating from the light source are projected at multiple first angles of incidence at the first point of incidence of the feature at the first incidence point of the feature. Light is incident on one surface. This first angle of incidence is measured on a first plane perpendicular to the optical axis of the film and including the first point of incidence. Each first angle of incidence is an angle formed between a projection line of the corresponding ray on the first plane on the first plane and a projection line of the normal of the first surface on the first plane at the first incidence point. Is measured.

Light that does not pass through the first surface, that is, light that enters outside the desired observation angle range, is reflected. This reflected light beam is incident on the second surface of the shaped body at a plurality of second incident angles at the second incident point. This second angle of incidence is also measured on a second plane perpendicular to the optical axis of the film and including the second point of incidence. Each second angle of incidence is defined by a projection line onto any of the second planes among the rays reflected in the second plane, and a normal to the second plane at the second point of incidence on the second plane. It is measured at an angle between the projection line. Each shaped body is configured such that substantially all of the light rays incident on the second surface of the shaped body have different first and second angles of incidence. Thus, light outside the desired viewing angle range of the film is reflected, and the light thus reflected is then redirected back to the film and transmitted through the film. This means that a brighter image can be obtained with the same amount of light.

[0012]

In an embodiment according to this aspect of the invention, the features on the second surface of the film are not continuous, and the film between the discontinuous features is transparent, reflective or opaque. It can be a film. In some other embodiments according to this aspect of the invention, the faces of the features have a slope (measured from the optical axis of the film) of between 10 ° and 80 °. In one preferred embodiment, each surface has a slope of 35 ° to the optical axis of the film, and in yet another embodiment the film has a refractive index of about 1.3 to 2.9 and in one preferred embodiment about It has a refractive index of 1.59. The film can be manufactured using partially reflective, light transmissive or partially transmissive materials. The film can be manufactured using a rigid material. The first surface of the film itself may be irregular. In some embodiments, the first surface of the film has an anti-reflective coating to selectively filter light of a particular wavelength. In another embodiment, the first surface may be partially reflective, for example, alternating strip-like reflective and transmissive materials on the first surface.

Another aspect of the present invention relates to a non-imaging film disposed between a light source and an image source to increase the brightness of the light provided to the image. Light incident on the film within the viewing angle range desired for the display is sent to the display to illuminate the display, and light outside the viewing angle of the display is completely internally reflected. This film is the first facing the light source
It has a surface, three dimensional axes, and a second surface having a number of features. Each feature on the second surface of the film has a first surface and a second surface. Light rays emitted from the light source are incident on the first surface of the shape at a first incidence point at a plurality of first angles of incidence and at a plurality of second angles of incidence. The first angle of incidence is measured on a first plane perpendicular to the first axis of the film's dimensional axis and including the first point of incidence. Each first angle of incidence is measured as the angle between the projection line of the ray on the first plane on the first plane and the projection line of the normal to the first plane on the first plane at the first point of incidence. Is done.

The second angle of incidence is measured on a second plane perpendicular to the second axis of the film's dimensional axis and including the first point of incidence. Each second angle of incidence is the second angle of the ray on the second plane.
It is measured at the angle between the projection line on the plane and the projection line on the second plane of the normal to the first plane at the first point of incidence. Light that does not pass through the first surface (therefore, light outside the desired observation angle range) is reflected. The reflected light is incident on the second surface of the profile at a second incidence point at a number of third angles of incidence and at a number of fourth angles of incidence. This third angle of incidence is also measured on a third plane perpendicular to the first axis of the film's dimensional axis and including the second point of incidence. Each third angle of incidence is defined by a projection line of one of the reflected rays on the third plane onto the third plane and a projection line of the normal to the second plane at the second point of incidence on the third plane. It is measured at the angle between Similarly, each fourth angle of incidence is measured on a fourth plane perpendicular to the second dimension axis of the film and including the second point of incidence. Each fourth angle of incidence is defined between a projected line on a fourth plane of one of the reflected rays and a projected line on a fourth plane normal to the second plane at the second point of incidence. It is measured at the angle formed. In each of the shaped bodies, substantially all of the light incident on the second surface of the shaped body has different first and third incident angles, and similarly has different shapes from the second and fourth incident angles.

In an embodiment according to this aspect of the invention, each shape on the second surface of the film is a polyhedron having at least three faces and a polygonal base having an odd number of sides. In another embodiment, each shape on the second surface of the film is a polyhedron having an irregular polygonal base having an even number of sides and at least four faces. The shapes can be discontinuous. In another embodiment, the second side of the film has a plurality of pyramid-shaped features, each pyramid-shaped feature having an irregular polygonal base with four sides and four faces, and four faces. Gradient (angle measured with respect to the first surface of the film)
Are each about 35 °.

According to yet another aspect, the present invention is directed to an article for changing the angular emission profile of light passing through the article. The article of the present invention has at least one structure having one optical axis and a surface that transmits some of the incident light rays and reflects the rest. The light ray is incident on the surface at a first point of incidence at a number of first angles of incidence. Each first angle of incidence is measured on a first plane perpendicular to the optical axis and including the first point of incidence. Each first angle of incidence is measured as the angle between the projection of one of the incident rays onto the first plane and the projection of the normal to the surface at the first point of incidence on the first plane. You. Light that does not pass through the surface is reflected. The reflected light beam is incident at a second incident point at a number of second incident angles. Each second
The angle of incidence is measured at a second plane perpendicular to the optical axis at the surface and including the second point of incidence. Each second angle of incidence is measured between a projected line on one second plane of the reflected light and a projected line on a second plane of a normal to the surface at the second point of incidence. . For substantially all of the reflected light, the first and second angles of incidence are different from each other, so that light outside the desired viewing angle range for the articles of the present invention is reflected. In still another aspect, the present invention is directed to a film comprising a display device having a low emission angle profile disposed between a light source and an image source. This film is laminated to the image source. Other objects, features, features, and advantages of the present invention will be apparent from the description and from the claims.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, like reference numbers indicate common parts.
The drawings are not necessarily to scale, and are exaggerated to illustrate the principles of the present invention. Referring to FIG. 5A, the present invention provides a device 50 having a substantially planar first surface 52 and a second surface comprising a plurality of pyramidal shapes 54 having an irregular polygonal base. For example, a film). The device 50 of the present invention is generally located between a light source for illumination and an image source (eg, LCD). Light emitted from the light source is incident on the first flat surface 52. The geometry of the profile 54 is selected to transmit light incident on the film within a desired viewing angle range, while at the same time light outside this viewing angle range is completely internally reflected back to the light source. In some embodiments, the light source can be a reflective surface or a Lambertian light source housed in a cavity, such that light internally completely reflected by the film returns to the flat surface 52 of the film 50. It has become.

For example, FIG. 5B shows a display device including the device 50 of FIG. 5A. Device 50 is light source 51
And the image source 53. The light source 51 may be a metallized reflective screen or a light source receiving cavity. Light that exits the light source 51 and is completely reflected internally by the device 50 is eventually reflected back by the light source back to the device 50. In the case where the light source 51 is a cavity accommodating a light, the cavity may be provided with a reflective coating for improving light re-reflection. Light that is not completely reflected internally by the device 50, ie, within the desired viewing angle range, is sent to the image source 53 to illuminate the image displayed thereon. Image source 53 can be a liquid crystal display. Further, the image source 53 may be a transparent or transparent film, and an image may be displayed thereon.

FIG. 5C is a top view of a portion of the embodiment of FIG. 5A. FIG. 5D is a top view of a portion of another embodiment, in which the shape 54 has a regular polygonal bottom surface and a polyhedral shape having an odd number of faces. In another embodiment of the present invention, the shape of the shape 54 is completely irregular. The shape body 54 does not necessarily have to be a continuous shape. FIG.
E shows the specific example of FIG. 5A in which the shape bodies are arranged at intervals from each other. Shape on the second surface of device 50
54 need not be of a single type. Conversely, device 50 may be a single large feature 54 having the properties of the present invention. Device 50 can be made of a partially reflective, transmissive, or partially transmissive material. The refractive index (n) of the material chosen to make device 50 must be known. This is because it is necessary to use this number in order to calculate an appropriate shape and size of the pyramid 54 as described below. For example, the device is polycarbonate (n = 1.59), glass (1.5 <n <1.
7) or made from a material selected from titanium oxide (n = 2.9).

In a preferred embodiment, device 50 is made in the form of a film. In this embodiment, the film can be manufactured using a polymer selected from the group consisting of polystyrene, polyolefin, acrylic resin and copolymers of these polymers. Also, the film can be made of a methyl methacrylate / styrene / hydroxyethyl acrylate terpolymer. Light first strikes the flat surface 52 of the device 50. The light source can be a lamp that emits light as in a backlight LCD. The light source may be a reflective screen, on which the device 50 may be stacked.

As shown in FIGS. 6A and 6B, with any light source, a ray 56 propagates through the device 50 and strikes either feature 54 at a first point of incidence 58. Whether the light ray 56 exits the film and is directed toward the image source or reflected depends on Snell's law. Snell's law is expressed by the following equation. n ₁ sinΘ ₁ = n ₂ sinΘ ₂ (where n ₁ is the refractive index of the device 50, n ₂ is the refractive index of the surrounding environment (eg, n ₂ = 1 for air), and Θ ₁
Is the angle of incidence measured perpendicular to the normal at the first point of incidence 58, and Θ ₂ is the angle of incidence of the ray 56 measured at the first point of incidence 58 relative to the normal and exits the profile 54 Thus, by appropriately selecting the material of the device 50 and the angle of the first surface of the profile 54, the transmission of the light beam can be adjusted so that transmission only occurs within a particular angular range.

For example, if the device 50 is made of polycarbonate having a refractive index n = 1.59, the refractive index of air is n = 1.0.
Therefore, applying Snell's law yields the following relation: 1.59 sin Θ ₁ = sin Θ ₂ Angles Θ ₁ and に 対 し て₂ are measured relative to the normal to the surface. Theta various values of the put value theta ₂ of the ₁ is obtained. For example, if Θ ₁ = 20 °, Θ ₂ = 32.94 °. Similarly Θ
_{If 1} = 15 °, then Θ ₂ = 24.30 °. Also, rays
56 is a medium having a high refractive index, for example, polycarbonate (n =
When traveling from 1.59) or quartz glass (n = 1.458) to a medium of lower refractive index, for example air, the light rays are totally internally reflected. In other words, for a critical angle Θ _c , the refracted ray moves parallel to the surface of device 50, and for incident angles greater than the critical angle, the ray is completely reflected off the surface. The critical angle is Snell's law, Θ ₂ = 90 ° and Θ ₁ = Θ
Obtained when _c is set. Thus, for polycarbonate, solving for: 1.59 sin Θ _c = sin (90 °) Θ _c gives the following solution: Θ _c = sin ^-1 (.629) = 38.97 °

That is, the critical angle of the polycarbonate device in air is 38.97 °. Light rays incident on the first surface of the device 50 at angles above this critical angle are completely internally reflected. The critical angle of device 50 is the device
It can be changed by beveling the surface 54 of 50. For example, if the device 50 is a polycarbonate having a pyramid with a surface having a slope angle of 1 °, the light beam enters the device 50 even at an angle smaller than the critical angle. This is 1 °
Because light incident on a flat surface at 39 ° (greater than the critical angle of polycarbonate and therefore totally reflected internally) is incident on the pyramid surface at an angle of 38 °. Since 38 ° is smaller than the critical angle of polycarbonate, this light ray is transmitted without being completely reflected inside.

As shown in FIG. 6A, when light ray 50 is completely internally reflected, the light ray enters shape 54 at a second point of incidence 60. The angle at which the light beam 56 is incident at the second point of incidence 60 also follows Snell's law and can be adjusted to allow the light beam 56 to be transmitted or reflected back to the device 50. Device out of light source 51
For each ray 56 propagating in 50, ray 56 is the first
There are three types of angles at which the light enters the shape 54 at the incident point 58.
For example, with reference to FIGS. 6A, B, 7A, B and 8A, B, the light beam 56 has a first point of incidence 58 and a second point of incidence 60.
And enters the shaped body 54. 6B, 7B and 8B
Shows a method of measuring all three first angles of incidence and all three second angles of incidence corresponding to the three dimensional axes of device 50.

Three planes 62, 66, 70 including a first point of incidence 58
Can be defined. Each plane is perpendicular to one of the dimensional axes of device 50. Each plane 62, 66 and 70
Defines the angle at which the light ray 56 is incident on the shape body 54 (光線₁ in Snell's law). For example, FIG. 6B shows the projection of ray 56 onto plane 62. The projection lines of the normal plane 72 are also shown. The angle of incidence of the ray 56 is the ray 56 on the plane 62
And the projection line of the normal plane 72 on the plane 62. Similarly, FIG. 7B shows that the angle of incidence is measured between the line of projection of ray 56 on plane 66 and the line of projection 74 on plane 66 of normal 54 to feature 54 at point of incidence 58. Is shown. FIG. 8B illustrates a method of measuring the angle of incidence of light ray 56 on plane 70 between the projection of light ray 56 on plane 70 and the projection of normal 76 on plane 70. The reflected ray 56 is the second incident point 60
6B, 7B and 8B show a second angle of incidence between the projection line of the reflected ray 56 and the projection lines of the normal planes 78, 80 and 82 at planes 64, 68 and 72. 2 shows a method for measuring

The geometric dimensions of the profile 54 are such that for almost all of the rays 56 incident at the second point of incidence 60, the second angle of incidence is at least with respect to a plane perpendicular to the optical axis of the film (planes 70 and 72 in this embodiment). Must be selected to be different from the first angle of incidence. Thereby, side lobe radiation along the axis is reduced. In an embodiment of the invention, each angle of incidence is different in a plane perpendicular to two of the three axes or in a plane perpendicular to all three axes. For example, as shown in FIGS. 5A, C, 6A, 7A, and B, the device 50 can have pyramidal surface protrusions on which light rays 56 are incident. Light rays are applied to each of the shapes 54, for example, at 45 ° (FIG. 6B), 45 ° (FIG. 7B) and
Light is incident at an angle B). This angle is only an example,
It should be understood that light from a light source generally includes light rays having a wide range of angles of incidence. Now, considering the use of the polycarbonate device 50 in air, the light beam
It can be seen that because 56 is incident at an angle greater than the critical angle (38.97 ° for polycarbonate), ray 56 is completely internally reflected and enters shape 54 at second point of incidence 60. Ray 56 is from the first point of incidence due to the law of reflection
It is reflected at angles of 45 °, 45 ° and 40 °. However, the angle at which the light ray 56 is incident at the second point of incidence naturally depends on the actual shape and size of the shape 54.

Light rays having different first and second angles of incidence are reflected back to device 50. These reflected rays 56 are then directed towards the device and attempt to transmit again.
This can be achieved by providing a reflective light cavity in embodiments where the light source is a lamp. In such an embodiment, light can also be reflected off a metallized screen. FIG. 9 is a graph showing an energy flux with respect to a vertical observation angle and a horizontal observation angle in a specific example of the present invention.
Side lobe radiation corresponding to energy loss appears as a depression near the end of the flux plot. Inventive device 50
Can be designed using an iterative method.
That is, the initial gradient of the surface or surface of the shape 54 is selected, and the transmission or reflection of a large number of incident light rays is calculated from Snell's law. The number of rays to simulate depends on the level of the dedicated computer. The initial gradient is chosen to maximize light transmission within the desired viewing angle range. Generally, this is done based on the critical angle of the selected material. For example, an approximate expression for subtracting the critical angle from 90 ° can be used.

Light that is not transmitted, that is, light that is incident on the first surface at an angle greater than the critical angle of the material forming the profile 54, is completely reflected inward. The reflection paths of these light rays can be determined by any known method, for example, a ray tracing method. Whatever method is used to determine the path of the reflected light, the second angle of incidence of each light is
54 and the angle at which the ray is reflected at the first point of incidence. In a preferred embodiment, the second
The slope of the surface or surface of the feature 54 at the point of incidence is the same as the initial slope. If the shape 54 is a regular polyhedron, this means that the light ray is incident at the second incident point at substantially the same angle as the first incident angle. To avoid this, the shape 54 is made asymmetric.

There are many ways to make it asymmetric. For example, a polyhedron having an odd number of faces is used. In this specific example, the first angle of incidence and the second angle of incidence of the light beam are different because the surfaces do not face each other. Another way to treat rays asymmetrically is to use a polygonal polyhedron 54 with an even number of sides but an irregular base. In this specific example, since the bottom surface is an irregular polygon, the surfaces of the pyramid 54 do not face each other exactly. The degree of irregularity of the polyhedral bottom is chosen to be half the critical angle of the material. For example, for a polycarbonate device 50 with a critical angle of 38.97 °, the initial anomaly is 20
° and the bottom with four sides is not square, 110 °
And a parallelogram with an angle of 70 °.

Once the shape 54 has been asymmetrically determined, Snell's law is used to determine which reflected light is transmitted and which is completely internally reflected at the second point of incidence. If too much light is transmitted outside the desired viewing angle range, i.e., the filtering effect is too low, the surface or surface gradient of the shape 54 or the degree of asymmetry of the shape 54 is slightly changed. After changing the shape 54, the ray path is calculated again. Repeat this process until acceptable results are obtained.

In embodiments of the present invention, the flat surface 52 may be grooved to redirect light before it is reflected by the device 50. This groove is shown in FIGS. 1, 2A, B,
3A, B and 4A-C, or carve facets on flat surface 52 to accommodate the present invention (fac
eted) can be. Alternatively, the flat surface 52 can be covered with an anti-reflective coating to reduce or eliminate the reflection of light at certain wavelengths. The anti-reflective coating can be applied to the entire flat surface 52 or formed in a strip. When the antireflection film is formed in a band shape on the flat surface 52, the antireflection band and the reflection band can be alternately arranged. In a specific example in which a rigid material, for example, glass is selected as a material forming the device 50, the shape body 54 can be formed on the device surface by any known embossing method. Or an appropriate shape
The film having 54 can also be produced by a known extrusion molding method such as blow molding.

In the above embodiment, the shapes 54 are continuous, but need not be continuous, because the desired shape is not "dense" or using the device 50 of the present invention. Because the application does not require a continuous shape 54, the shape 54 may be discontinuous. . In embodiments where the features 54 are not continuous, the material between each feature 54 may be opaque, reflective, transmissive or partially transmissive. Various changes, improvements and additions to the above specific examples do not depart from the scope of the present invention. The present invention is not limited to the above embodiments, but is limited only by the spirit and scope of the claims.

[Brief description of the drawings]

FIG. 1 is a perspective view of a film having a groove on a surface.

FIG. 2A is a perspective view showing one of the triangular protrusions of the film of FIG. 1, showing one incident light beam. B is a side view of the triangular protrusion of A, showing the incident angle of the light beam.

FIG. 3A is a perspective view showing one of the triangular protrusions of the film of FIG. 1, showing one incident light beam. B is an end view of the triangular protrusion of A, showing the incident angle of the light beam.

FIG. 4A is a perspective view showing one of the triangular protrusions of the film of FIG. 1, showing one incident light beam. B is a plan view of the triangular protrusion of A, showing the incident angle of the light beam.

5A is a perspective view of an embodiment of the present invention showing a plurality of asymmetric pyramid-shaped projections formed on one side, FIG. 5B is an exploded view of a display device incorporating A, FIG. E is a plan view of another embodiment of the present invention in which a plurality of polyhedrons each having a regular polygonal bottom surface and an odd number of surfaces are arranged on one side; FIG.
FIG. 7 is a perspective view of another embodiment of the present invention in which a plurality of discontinuous asymmetric pyramid-shaped projections are formed on one side.

FIG. 6A is a perspective view showing one of the asymmetric pyramid-shaped protrusions of the film of FIG. 5A, showing one incident light beam. B is a side view of the triangular protrusion of A, showing the incident angle of the light beam.

FIG. 7A is a perspective view of one of the asymmetric pyramid-shaped protrusions of the film of FIG. 5A, showing one incident light beam. B is an end view of the triangular protrusion of A, showing the incident angle of the light beam.

FIG. 8A is a perspective view showing one of the asymmetric pyramid-shaped protrusions of the film of FIG. 5A, showing one incident light beam. B is a plan view of the triangular protrusion of A, showing the incident angle of the light beam.

FIG. 9 is a light intensity isometric graph of the film of FIG. 5A.

Claims (43)

[Claims] A first surface facing the light source, an optical axis perpendicular to the film, and a second surface having a plurality of features for altering an emission angular profile of light emitted from the light source. (1) a first surface on which a plurality of light beams from a light source are incident at a first incident point at a plurality of respective first incident angles, wherein each of the first incident angles is a light Measured at a first plane perpendicular to the axis and including the first point of incidence, wherein each first angle of incidence is relative to a line of projection of each incident ray onto the first plane and a first plane at the first point of incidence. A first surface measured at an angle between a normal and a projection line onto a first plane; and (2) a plurality of light rays reflected by the first surface are reflected at a second point of incidence by a plurality of respective second light sources. A second surface incident at an angle of incidence, wherein each second angle of incidence is measured on a second plane perpendicular to the optical axis and including the second point of incidence; The the elevation angles of the reflected light 2
A second plane measured at an angle between a line of projection onto the plane and a line of projection normal to the second plane at the second point of incidence on the second plane, and incident on the second plane The first incident angle and the second incident angle of almost all of the incident light are different. 2. The film according to claim 1, wherein the shape is discontinuous. 3. The film according to claim 2, wherein the area between each feature of the film is made of a transparent material. 4. The film of claim 2, wherein the area between each feature of the film is made of an opaque material. 5. The optical system according to claim 1, wherein the first surface and the second surface are 10
2. The film according to claim 1, having a gradient of from 80 to 80. 6. The film according to claim 5, wherein the gradient is about 35 °. 7. The film according to claim 1, wherein the film is made of a material having a refractive index of 1.3 to 2.9. 8. The film of claim 7, having a refractive index of about 1.59. 9. The film of claim 1, wherein the light source comprises a reflective material. 10. The film according to claim 1, comprising a permeable material. 11. The method according to claim 1, comprising a partially permeable material.
The film according to 1. 12. The film of claim 1, comprising a rigid material. 13. The method of claim 1, wherein the first surface comprises an irregular surface.
The film according to 1. 14. A film for altering the emission angular profile of light emitted from a light source, said film having three axes, and having a first surface facing the light source and a plurality of features. (1) a plurality of light rays from a light source are incident at a first point of incidence at a plurality of respective first incident angles and at a plurality of respective second incident angles. Plane, wherein each first angle of incidence is measured on a first plane perpendicular to the first of the three axes and including the first point of incidence, wherein each first angle of incidence is Measured at an angle between a projection line onto one first plane and a projection line onto the first plane with a normal perpendicular to the first plane at the first point of incidence; The angles of incidence are measured on a second plane perpendicular to the second of the three axes and including the first point of incidence, where each second angle of incidence is Measured at an angle between the projection line of the same incident ray on the second plane at the first incidence point and the projection line of the normal to the first plane at the first point of incidence on the second plane. (2) a plurality of light beams reflected by the first surface are reflected at a second incidence point at a corresponding plurality of third incident angles and a corresponding plurality of fourth surfaces; A second surface incident at an angle of incidence, wherein each third angle of incidence is measured on a third plane perpendicular to the first axis and including the second point of incidence, wherein each third angle of incidence is Measured at an angle between a projection line onto one third plane and a projection line onto the third plane of a normal to the second plane at the second point of incidence, wherein each fourth angle of incidence is a second The fourth angle of incidence is measured on a fourth plane perpendicular to the axis and including the second point of incidence, where each fourth angle of incidence is a line of projection of the reflected ray onto one fourth plane and a second angle of incidence at the second point of incidence. A second plane measured at an angle between a normal to the projection plane on a fourth plane and substantially all of the rays incident on the second plane are different from each other. And the second incident angle and the fourth incident angle are different. 15. The film of claim 14, wherein each shape comprises a polyhedron having a polygonal bottom surface having an odd number of sides and at least three surfaces. 16. The film of claim 14, wherein each shape comprises a polyhedron having an irregular polygonal bottom surface having an even number of sides and at least four surfaces. 17. The film according to claim 14, wherein the shapes are discontinuous. 18. The film according to claim 17, wherein the area between each feature of the film is made of a transparent material. 19. The film of claim 17, wherein the area between each feature of the film is made of an opaque material. 20. The first surface and the second surface have a slope of 10 ° to 80 ° with respect to a normal to the first surface.
The film according to 1. 21. The film according to claim 20, wherein the gradient is about 35 °. 22. The film according to claim 14, comprising a material having a refractive index in the range of about 1.3 to 2.9. 23. The film according to claim 22, having a refractive index of about 1.59. 24. The film according to claim 14, comprising a rigid material. 25. The film according to claim 14, wherein the light source comprises a reflective material. 26. The film according to claim 14, comprising a permeable material. 27. The method of claim 14, comprising a partially permeable material.
The film according to 1. 28. The method of claim 1, wherein the first surface has an irregular surface.
14. The film according to 14. 29. An article for changing the angular emission profile of light, comprising at least one structure having one optical axis and one surface that transmits some of the plurality of incident light rays and reflects the rest. Wherein a plurality of light rays impinge on the surface at a first point of incidence at a plurality of first angles of incidence, each first angle of incidence being orthogonal to the optical axis and a first angle of incidence.
The first angle of incidence is measured on a first plane containing the point of incidence, wherein each first angle of incidence is a line of projection of one of the incident rays onto the first plane and a first normal of the surface to the surface at the first point of incidence. A plurality of reflected rays are incident on the surface at a second point of incidence at a plurality of second angles of incidence, each second angle of incidence being relative to the optical axis The second angle of incidence, measured at a right angle and on a second plane containing a second point of incidence, wherein each second angle of incidence is one of the reflected rays projected onto the second plane and the surface at the second point of incidence. An article, characterized in that substantially all of the reflected light has a first angle of incidence and a second angle of incidence that are different from each other, measured at an angle between the second normal to the projection line of the second normal onto the second plane. 30. The article according to claim 29, wherein the article is comprised of a plurality of structures. 31. The article of claim 30, wherein the structure is discontinuous. 32. The article of claim 31, wherein the area between each structure of the article is comprised of a transparent material. 33. The article of claim 31, wherein the area between each structure of the article is comprised of an opaque material. 34. The article of claim 29 comprising a permeable material. 35. The method of claim 29, comprising a partially permeable material.
Articles described in. 36. The article of claim 29 comprising a rigid material. 37. The method according to claim 29, wherein the first surface comprises an irregular surface.
Products described in. 38. A display device having a small emission angle profile comprising a light source, an image source, and the article of claim 29 disposed between the light source and the image source. 39. The display device according to claim 38, wherein the article is a film laminated to an image source. 40. A display device having a low angular emission profile comprising a light source, an image source, and the film of claim 1 disposed between the light source and the image source. 41. A film according to claim 41, wherein the film is laminated to the image source.
41. The display device according to 40. 42. A plurality of pyramid-shaped bodies each comprising (a) a first surface facing a light source, and (b) an irregular polygonal bottom surface having four sides and four surfaces. A film for changing the emission angle profile of light emitted from the light source. 43. The film of claim 42, wherein the four sides have a slope of about 35 ° to the first side.