Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/1055—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer
  • B32B17/10559—Shape of the cross-section
  • B32B17/10568—Shape of the cross-section varying in thickness
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/10—Beam splitting or combining systems
  • G02B27/14—Beam splitting or combining systems operating by reflection only
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/10009—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets
  • B32B17/10036—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets comprising two outer glass sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/1055—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer
  • B32B17/10761—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer containing vinyl acetal
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B27/0101—Head-up displays characterised by optical features
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B27/0101—Head-up displays characterised by optical features
  • G02B2027/0118—Head-up displays characterised by optical features comprising devices for improving the contrast of the display / brillance control visibility
  • G02B2027/012—Head-up displays characterised by optical features comprising devices for improving the contrast of the display / brillance control visibility comprising devices for attenuating parasitic image effects
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B27/0101—Head-up displays characterised by optical features
  • G02B2027/0118—Head-up displays characterised by optical features comprising devices for improving the contrast of the display / brillance control visibility
  • G02B2027/012—Head-up displays characterised by optical features comprising devices for improving the contrast of the display / brillance control visibility comprising devices for attenuating parasitic image effects
  • G02B2027/0121—Parasitic image effect attenuation by suitable positioning of the parasitic images
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B2027/0192—Supplementary details
  • G02B2027/0194—Supplementary details with combiner of laminated type, for optical or mechanical aspects

Definitions

• This invention relates generally to display panels for vehicle windshields, and more particularly, to a display panel integral with an automotive windshield, for the head-up monitoring of vehicle operating information.
• Head-up display panels are commonly used in systems for projecting vehicle operating information onto a vehicle windshield, for reflecting images into the operator's forward field of vision. The operator can thereby simultaneously view the area in front of the vehicle and the displayed information.
• Various head-up display systems are currently utilized in the aircraft industry.
• a head-up display system in an automobile minimizes the operator's need to divert his attention from observation of the road to periodic observation of the dashboard display panel.
• Such a system which allows an operator to continuously focus his attention on the road and simultaneously view essential vehicle operating information, greatly enhances the safety of vehicle passengers and others .
• Whi_e the advantages of head-up displays are apparent, the use of such displays in automobiles will become widespread only if they can be integrated into the vehicle windshield manufacturing process, within the stringent cost and quality requirements of the automotive industry.
• the head-up display systems currently used in the aircraft industry are overly sophisticated and prohibitively expensive for use in automobiles. For example, United States Patent No. 4,775,218 to Hodel et al .
• a head-up display system comprising a movable combiner supported on brackets and positioned in the operator's forward line-of-sight.
• the display emanates from a stationary source and is projected onto a preselected position on the combiner, which is configured so that the display symbology is superimposed on the "real world" scene.
• Means for detecting the orientation of the combiner, relative to the image source, triggers a realignment of the combiner to maintain the preselected position of the display.
• laminated glazing units as employed in the windshields of automobiles, are generally produced by integrally bonding two sheets of glass to an interposed layer of plastic.
• the plastic interlayer material almost universally employed is polyvinyl butyral . Normally, the plastic interlayer material is differentially stretched to match the curvature of the associated glass sheets. Two such methods are described in United States Patent No. 3,912,440 to Koss et al . and United States Patent No. 4,554,713 to Chabal.
• the aforementioned automotive glazing units are not entirely satisfactory for use with a head-up display panel, however, for at least two reasons. Firstly, the geometry of the known glazing unit causes a reflection off the outboard surface of the windshield to appear as a secondary display image. The displacement between the secondary display image and the primary display image reflected off the inboard surface of the windshield may make the display symbology very difficult to decipher. Secondly, the relatively high transmissivity and low reflectance of the known glazing units produce a primary display image with low contrast under bright light conditions. Obviously, it is necessary that the display image be clearly visible under all ambient light conditions .
• the novel windshield for use with a head-up display system which markedly improves the image display as viewed by the vehicle operator.
• the novel windshield comprises an outboard sheet of glass, including a first, outboard or outwardly facing surface and a second surface opposite the first surface, a transparent interlayer including a first surface adjacent and adhered to the second surface of the outboard sheet of glass and a second surface opposite the first surface, with the interlayer having a predetermined wedge angle.
• An inboard sheet of glass includes a first surface adjacent and adhered to the second surface of the interlayer and a second, inboard or inwardly facing surface.
• a reflectance increasing patch of a metal oxide coating may be adhered to a portion of the inboard surface of the inboard glass sheet and positioned so as to be in the line-of-sight of an operator of the vehicle.
• the interlayer is disposed within the windshield with the wedge extending transversely thereof and tapering inwardly from the upper toward the lower regions of the head-up display viewing area.
• the interlayer wedge angle is selected pursuant to the anticipated installation angle of the windshield, thickness of the glass sheets, and angle of incidence of the projected image, so as to substantially superimpose the reflected images generated from a dashboard display device and reflected from the inboard surface or patch of the inboard sheet and from the outboard surface of the outboard sheet into a substantially singular image in the eyes of the vehicle operator.
• the vehicle windshields of the present invention are useful for providing the head-up display of operating information for the operator of a vehicle.
• a method of producing a windshield for a head-up display system of a vehicle comprising the steps of calculating the wedge angle at which the outboard and inboard sheets of glass are to be disposed in said vehicle head-up display system to cause primary and secondary reflected images of the display as viewed by a vehicle operator to be substantially superimposed, forming an interlayer sheet whose opposite major surfaces are disposed at substantially said calculated wedge angle to one another, assembling said interlayer sheet between said outboard and inboard sheets of glass, and laminating the assembly to secure said outboard and inboard sheets to said interlayer whereby said outboard and inboard sheets are disposed at said calculated wedge angle to one another .
• Fig. 1 is a perspective view of a windshield including a heads-up display panel, embodying the features of the present invention
• Fig. 2 is an enlarged, fragmentary, cross -sectional view, taken along line 2-2 of Fig. 1, illustrating the laminated glazing and the patch of metal oxide adhered thereto;
• Fig. 3 is a schematic representation of the operation of the windshield of Fig. 1.
• the windshield 10 comprises a laminated glazing 12 upon which a patch 14 of a reflecting material may be deposited to enhance visibility for the vehicle operator as will be hereinafter described.
• the laminated glazing 12 includes an outboard sheet of glass 16, a transparent interlayer 18, and an inboard sheet of glass 20.
• the outboard sheet of glass 16 includes a first, outboard surface 22 and a second surface 24 opposite the first surface 22.
• the inboard sheet of glass 20 includes a first surface 26, and a second, inboard surface 28 opposite the first surface 26.
• the transparent interlayer 18 is Interposed between the outboard sheet of glass 16 and the inboard sheet of glass 20.
• a first surface of the interlayer 18 is adjacent and adhered to the second surface 24 of the outboard sheet of glass, and a second surface of the interlayer 18 opposite the first surface is adjacent and adhered to the first surface 26 of the inboard sheet of glass 20.
• the patch 14 of reflecting material is optionally formed on a portion of the inboard surface 28 of the inboard glass sheet 20. It is positioned, as best seen in Fig. 1, so as to be directly in the line-of-sight of a person operating the vehicle and looking ahead of the vehicle through the windshield.
• the patch 14 may, for example, comprise a coating of a reflecting material such as a metal oxide, which has a reflectance greater than that of the uncoated glass surrounding the patch 14.
• the term "reflectance increasing”, as used herein, means that the coating must be sufficient to increase the reflectance of the coated surface over the uncoated inboard surface 28 of the inboard sheet of glass 20.
• the reflectance increase caused by the patch 14 results in a higher contrast ratio, the contrast ratio being equal to the intensity of the primary reflected image divided by the intensity of the outside image, and therefore in higher visibility for the vehicle operator.
• a contrast ratio of at least 1.8 is desirable. It is usually undesirable, however, to use a coating so thick that it adds color interference or iridescence to reflected or transmitted light.
• the patch 14 preferably is provided with a fade-out region 30, which immediately surrounds the periphery of the patch 14.
• the density of the metal oxide coating gradually decreases with increased distance away from the patch 14, thereby resulting in a correspondingly gradual diminution of the reflectance of the metal oxide coating.
• the thickness of the coating it is undesirable for the thickness of the coating to be such as to cause color interference or iridescence across the fade-out region.
• the fade-out region 30 minimizes the distraction to the driver caused by the higher reflectance of the patch 14, relative to the reflectance of the laminated glazing 12, which would otherwise result from an abrupt boundary between the patch 14 and the uncoated inboard surface 28 of the inboard sheet of glass 20.
• the patch 14 may conveniently be of any size or shape, as dictated by the configuration and quantity of information to be displayed.
• the geometry of the transparent interlayer 18 is generally defined as wedge-shaped, meaning that the distance between the first and second surfaces of the interlayer 18 decreases when measured at various points from the top of the laminated glazing 12 to the bottom.
• the wedge-shaped characteristic of the interlayer may be expressed in terms of the wedge angle, created by intersecting planes parallel to the first and second surfaces of interlayer 18.
• the appropriate wedge angle for a given application is a function of the windshield 10 installation angle, the glass thickness, and the angle of incidence of the projected image. Typically, the wedge angle varies between greater than zero and about 0.025° or more. In operation, as depicted in Fig.
• dashboard display device 32 an image which is intended to relate a vehicle operating parameter or any other piece of information, is projected at a predetermined angle of incidence relative to the inboard surface 28 from a dashboard display device, shown diagraminatically at 32, onto the inboard surface 28 or onto the patch 14 of reflective material as the case may be It is then reflected as the primary image to the eyes 34 of the vehicle operator.
• the dashboard display device 32 may comprise, for example, an illuminated or LED display, which is projected through an appropriate optical system either onto the patch coating 14 or directly onto the inboard surface 28 of the inboard glass sheet 20.
• a secondary image is simultaneously reflected from the outboard surface 22 of the outboard sheet of glass 16 toward the eyes of the operator.
• the primary and secondary images are substantially superimposed so as to appear as a singular image when observed by the vehicle operator.
• the reflectance increasing properties of the patch 14 will result in a higher contrast ratio between the primary and secondary images, equal to the intensity of the primary reflected image divided by the intensity of the secondary reflected image.
• the glass sheets 16 and 20 suitable for use in manufacturing the windshields 10 according to the present invention may include any of the conventional glass substrates known in the art as useful for the preparation of laminated vehicle windshields.
• the transparent interlayer 18 useful for the present invention may be prepared from conventional laminated glass interlayer materials such as, for example, polyvinyl butyral, plasticized polyvinyl chloride, multilayered thermoplastic materials including polyethylene terephthalate , etc. Suitable interlayer materials are more fully set forth in U.S. Patents, Nos. 4,287,107 and 3,762,988, which are incorporated herein in their entirety by reference thereto.
• a preferred transparent interlayer material is polyvinyl butyral .
• the windshield installation angle As heretofore indicated a number of factors, including the windshield installation angle, the image projection angle, the observers viewing position, and the interlayer wedge angle, determine the display image presented to the vehicle operator.
• these factors including the windshield installation angle, the image projection angle, the observers viewing position, and the interlayer wedge angle, determine the display image presented to the vehicle operator.
• this condition is corrected, or at least the effect is minimized, by fabricating, the windshield with an interlayer 18 having a wedge angle which results in the surfaces 22 and 28 being disposed at an angle which consequently causes the secondary image to converge toward the primary image as illustrated in Fig. 3.
• windshields having an interlayer wedge angle between about 0.006° and 0.046° produce a suitable display image in most HUD installations.
• An interlayer with a wedge angle of about 0.025° has been found very suitable for producing HUD windshields adaptable to a wide range of vehicle models wherein the secondary image of the display will be closely superimposed upon the primary image .
• Such deforming or expanding results in formation of a certain amount of thickness gradient, or wedge, across the interlayer.
• a similar procedure may be used for forming a transparent interlayer having a wedge- shaped configuration for use with the present invention, it has been found that an interlayer produced by such stretching of the plasticized material is not entirely satisfactory for use in the invention.
• the stretched material does not exhibit a uniform thickness gradient transversely across the web. Instead, the stretching has been found to result in random thickness variations transversely across the interlayer, as well as in directions disposed at an angle to the direction of stretching. In other words, the direction and magnitude of the interlayer wedge are not uniform.
• the degree of visual clarity which can be attained in superimposing the secondary Image upon the primary Image is adversely affected.
• the transparent interlayer 18 a sheet of interlayer material which has been extruded with the desired wedge angle between its opposite surfaces, so that subsequent stretching or expanding is unnecessary.
• the interlayer can thus be formed with the particular wedge angle desired and with a uniform straight line thickness variation across the interlayer.
• the extruded sheet likewise exhibits constant thickness in the longitudinal direction.
• the interlayer may be extruded with a precise predetermined wedge angle to produce in a windshield fabricated therefrom a high degree of optical uniformity.
• the interlayer material may have the aforementioned wedge angle of 0.025° found particularly suited for fabricating windshields for HUD systems Installed in many automobiles.
• a reflective patch 14 for example a metal oxide coating may be deposited on the laminated glazing 12, thereby forming the reflective display panel.
• Useful coatings are chromium oxide, tin oxide, aluminum oxide, zinc oxide, nitrides and the like.
• a preferred metal oxide is chromium oxide.
• the reflective coating may be applied to a portion of the inboard surface 28 of the inboard glass sheet 20 by conventional coating techniques such as, for example, chemical vapor deposition or reactive sputtering of a metal or metal oxide.
• a particularly useful method includes the cathode atomization sputtering of the metal oxide coating onto the inboard surface 28, utilizing a mask or shutter arrangement to define the size and shape of the patch 14.
• the mask or shutter is conveniently superposed relative to the inboard surface 28 of the inboard glass sheet 20, so as to cause overspray at the peripheral edges of the patch 14, thereby forming the fade-out region 30 of the display panel.
• Specific methods for sputter coating a metal oxide onto glass utilizing masks or shutters are described fully in U.S. Patent Nos. 4,562,093 and 4,278,528, which are incorporated herein in their entirety by reference thereto.
• the process of the present invention generally involves the aforementioned steps of assembling and laminating together an outboard sheet of glass 16, an inboard sheet of glass 20, and a wedge-shaped sheet of transparent interlayer material 18 therebetween.
• the patch 14 of reflective material may then be applied to the laminated glazing 12.
• Comparison 1 A laminated glazing is manufactured utilizing two glass sheets and a polyvinyl butyral transparent interlayer of uniform thickness therebetween.
• a patch of zinc oxide having a height of about 14 inches and a width of about 5.5 inches is sputter coated onto the inboard surface of the laminated glazing.
• the transmissivity of the coated area is about 70% while the transmissivity of the uncoated laminated glazing is about 77%.
• a fadeout region extends away from the periphery of the patch about 1.5 Inches.
• the windshield with the display panel is installed at an angle of about 27° from vertical, and light from the display device is projected onto the zinc oxide coating at an angle of incidence of about 68.75°.
• the resulting primary and secondary images are displaced by 119 mils at a distance from the windshield of about 94.5 inches.
• the corresponding angular displacement of the images is about 0.072°, which appears as a double or blurred image to the operator.
• Example I A windshield is prepared and installed, and the procedures repeated, as described in Comparison 1, excepting that a wedge-shaped interlayer of polyvinyl butyral is employed according to the present invention.
• the interlayer sheet has a thickness at the top of the laminated glazing about 10 mils greater than at the bottom, a distance of about 36 inches, resulting in a wedge angle of about 0.0155°.
• the displacement between the primary and secondary images is about 11 mils at a distance of about 94.5 inches.
• the corresponding angular displacement Is about 0.007°. This amount of angular displacement presents a substantially singular image to the vehicle operator.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Instrument Panels (AREA)
• Joining Of Glass To Other Materials (AREA)
• Window Of Vehicle (AREA)
• Devices For Indicating Variable Information By Combining Individual Elements (AREA)

Applications Claiming Priority (4)

Publications (2)

Family

ID=27025494

Family Applications (1)

Country Status (8)

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• 1990
  • 1990-10-11 MX MX022824A patent/MX171971B/es unknown
  • 1990-10-15 CA CA002027348A patent/CA2027348A1/en not_active Abandoned
  • 1990-10-15 KR KR1019910700599A patent/KR920701853A/ko not_active Withdrawn
  • 1990-10-15 EP EP19900917161 patent/EP0450058A4/en not_active Withdrawn
  • 1990-10-15 AU AU67516/90A patent/AU6751690A/en not_active Abandoned
  • 1990-10-15 JP JP3500393A patent/JPH04502525A/ja active Pending
  • 1990-10-15 WO PCT/US1990/005901 patent/WO1991006031A1/en not_active Ceased
  • 1990-10-15 BR BR909006955A patent/BR9006955A/pt unknown

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