Abstract: A retractable holographic combiner, of the type comprising a movable holographic mirror placed before the pilot's eyes and designed for the presenting of light images collimated at infinity, superimposed on the external scene, and coming from a projector positioned upline with respect to the combiner, the holographic mirror being connected to a fixed part of the aircraft by a hinged support that provides for holding it and positioning it, wherein the support of the holographic mirror is constituted by a single lateral connecting arm comprising a first upper hinge connecting said arm by one of its ends to the fixed part of the aircraft and a second lower hinge connecting said arm by its other end to a side of the holographic mirror so as to obtain a complete retraction of the assembly.

Abstract: A head-up display system for a vehicle includes a front windshield, a display, a polarizing member and an optical rotatory film. The display for displaying an image on the front windshield to be viewed by a driver of the vehicle is disposed such that light therefrom is incident on the front windshield at an angle which is substantially equal to Brewster's angle. The polarizing member is disposed between the front windshield and the display for polarizing light from the display. The optical rotatory film serves to rotate the plane of polarization of light polarized by the polarizing member. The optical rotatory film installed on the front windshield includes a liquid crystal high polymer which is in twisted nematic orientation under liquid crystal condition and is in glassy condition at a temperature which is lower than liquid crystal transition point. Thus, double image problem can be eliminated with respect to light having a wide range of wavelengths.

Abstract: A vehicular display system can project optical images onto different areas on a front windshield in accordance with the effective height of a driver's eyes. The display system includes an image source and a mirror, either of which can be tilted manually and/or automatically. The mirror reflecting an image from the image source onto the inside of the windshield at an angle suitable for reflection toward the driver's eyes and at a height on the windshield fully within the driver's field of view. An electrically controlled seat can provide seat position and inclination signals for use in automatically adjusting the display height. In addition, a memory may hold manually entered display-height information to expedite readjustment of the display height in cases where more than one driver uses the vehicle.

Abstract: Holographic flake pigments, processes for making the pigments, decorative coatings comprising the pigments, and articles comprising the decorative coatings are disclosed. The pigment comprises particles that (1) comprise an organic polymer and further comprise one or more volume phase holograms; and (2) have a thickness of about 1 micrometer to about 100 micrometers, an average diameter of about 10 micrometers to about 300 micrometers, and a thickness to diameter ratio of about 1:2 to about 1:60.

Abstract: A hologram structure for use in a holographic center high mounted stoplight system for a vehicle. The hologram structure includes an illumination source for providing a reconstruction beam, a first array of non-overlapping hologram cells and non-hologram cells, and a second array of non-overlapping hologram and non-hologram cells. Each hologram cell of the first array produces a specular image that is viewable in a first predetermined angular field pursuant to diffraction of a portion of the reconstruction beam, and each hologram cell of the second array produces a diffuse image that is viewable in a second predetermined angular field pursuant to diffraction of a portion of the reconstruction beam. The specular images and diffuse images produced by the first and second holograms form stoplight illumination.

Abstract: A holographic center high mounted stoplight system that includes a light source for providing a nearly collimated beam, an expanding lens responsive to the nearly collimated beam for providing a diverging or converging reconstruction beam, and a stoplight hologram responsive to the expanding beam for producing stoplight illumination. Also disclosed is a holographic center high mounted stoplight system that includes a light source for providing a nearly collimated beam, a light bending hologram for providing a diffracted near collimated beam, and an expanding stoplight lens array responsive to the diffracted near collimated beam for providing non-collimated stoplight illumination.

Abstract: Glare and spurious reflections of external light on the image source of a head up display are eliminated by a circular polarizer in the optical path of the display. The head up display includes a mirror system for projecting a pattern from the image source onto a vehicle windshield where it is reflected to the operator, wherein polarization is effected at the windshield reflection. The circular polarizer includes a linear polarizer and a quarter wave plate arranged to extinguish the external incident light after reflection from the image source. The linear polarizer axis is aligned with the polarization axis at the windshield to optimize the brightness of the display.

Abstract: A holographic sight which includes a base having at least one connector for mounting the base on a small arm, and a hologram of a reticle pattern, a compact laser light source for illuminating the hologram, and a power source for the laser diode, each mounted on the base. The sight also includes an achromatizer supported in the path of the light beam for reducing shifts in the position of the reticle pattern due to variations in the wavelength of the light beam emitted from the laser diode. The sight may further include means for circularizing the generally elliptical beam emitted by the laser diode to provide a uniform illumination pattern for the hologram. A brightness adjuster and position adjuster, for varying the brightness and relative position of the reticle, respectively, may also be provided.

Abstract: A hed-up display comprises a light source and a liquid crystal display device for displaying an image, and a hologram arranged on a windshield glass of a vehicle to diffract the light to an observer, wherein the hologram has the half width of the diffraction spectrum so that a white light entering into the vehicle from the outside is diffracted as substantially a white light.

Abstract: Heads-up and heads-down displays employing holographic stereograms are provided. The stereograms can be oriented perpendicular to the user's line of sight (the "90.degree. case") or at angle to the line of sight (the "non-90.degree. case"). The stereograms are produced using a three-step process in which a series of two-dimensional perspective views are prepared, a H.sub.1 hologram is prepared from the two-dimensional perspective views, and a H.sub.2 hologram is prepared from the H.sub.1 hologram. For the non-90.degree. case, the two-dimensional perspective views are oriented at an angle relative to the plane of the H.sub.1 hologram during the preparation of that hologram. Similarly, during the preparation of the H.sub.2 hologram for this case, the H.sub.2 hologram is oriented at an angle relative to the H.sub.1 hologram. In this way, the viewing slits generated by the holographic stereogram are located in the vicinity of the user's eyes for the non-90.degree. case as is desired.

Abstract: A non-regular reflection type holographic mirror which can reduce, when mounted as a reflection plate on a windshield of a vehicle, the inclination of a display image visually discerned by reflection and a process of manufacturing the same. The holographic mirror comprises a hologram plate including a transparent support member and a photosensitive agent layer formed on the transparent support member and having interference fringes formed therein such that the hologram plate has a function of a concave mirror at a first portion of the hologram plate and another function of a convex mirror at a second portion of the hologram plate on opposite sides of a horizontal center line. A reflection type display apparatus for a vehicle employing a non-regular reflection type hologram or a regular reflection type hologram constituting a concave mirror as a hologram combiner wherein a virtual image of a display unit is reversed into an erect image and compensated for in contraction to improve the discernibility.

Abstract: A hologram structure for use in a holographic center high mounted stoplight system for a vehicle. The hologram structure includes first and second hologram layers laminarly secured to each other, each having a plurality of bright hologram cells and dim hologram cells formed therein, and each hologram cell being configured to diffract light into a predetermined solid angular region. The bright hologram cells and the dim hologram cells of each hologram are arranged in a pattern to produce a recognizable pattern of bright and dim areas.

Abstract: To servocontrol the direction and the position of a collimation mirror of a head-up visor, holographic elements are used. These holographic elements deflect a part of the light reflected by the mirror towards sensors located outside the field of view.

Abstract: In a windshield having a holographic element integrated in the windshield for example a reflection hologram for reflecting optical information into the visual range of the driver, the edge region (4) of the hologram is resolved like a web. The web decreases from a high area fraction in the zone adjoining the actual hologram to a low area fraction in the zone bordering the glass area.

Abstract: A compact, inexpensive and mass-producible optical display system for an automobile creates a dramatic and highly stylistic, sharp, high contrast and pleasing, multi-color or monochromatic 3-D magnified image of an instrument cluster, at least a portion of the 3-D image being located at a viewing distance greater than the actual optical distance between the dashboard and the driver's eyes. A non-pupil forming display system uses an off-axis aspherical narrow-band reflecting mirror with power to create a magnified virtual image of a miniaturized passive image source, such as a segmented LCD panel, which is backlighted by a small filament incandescent light bulb. A single mirror produces a single monochromatic virtual image, whereas a plurality of stacked and differently curved mirrors, each tuned to different wavelength bandwidth, produces a plurality of spatially separated virtual images of differing colors. The mirrors are holographic optical elements or graded index optical elements.

Abstract: A hologram structure for use in a holographic center high mounted stoplight system for a vehicle. The hologram structure includes a hologram layer having a plurality of holographic lenses formed therein, each holographic lens being configured to diffract light into a predetermined solid angular region.

Abstract: A holographic center high mounted stoplight (CHMSL) system for a vehicle having a rear window. The CHMSL system includes a stoplight hologram secured adjacent the rear window, a playback illumination source for providing along a source optical axis a vertically converging beam that converges to a horizontal line focus, and a thick concave/convex lens responsive to the vertically converging beam for (1) controlling the vertically converging beam to converge to a line focus that is within said lens and further from the illumination source than such line focus would be without the lens and (2) providing an output beam along an output axis that is tilted upwardly relative to the source optical axis.

Abstract: A display apparatus having an image generator and a beam combiner including a hologram for displaying a reduced image by receiving beams from the image generator. A virtual image of an image generated by the image generator is formed in the vicinity of the beam combiner by virtue of the image reductioning function of the beam combiner, so that the displayed image is visible from a wider range of viewing positions.

Abstract: An automotive display apparatus displays synthetically an ordinary information like a vehicle speed value and a warning information like a remaining fuel amount by using a half mirror as a close range view and a distant range view. A control means determines contents of the ordinary information and the warning information on the basis of input signals from a plurality of sensors. When the warning information is displayed, the warning information is provided at a position that the warning information overlaps with the ordinary information in the line direction of a driver's sight and the warning information is away from the ordinary information by a predetermined distance to enable the driver to notice and observe the warning information easily. At the same time, the ordinary information at the overlap portion of the ordinary and warning information in the line direction of the driver's sight is inhibited from being displayed.

Abstract: The present invention provides a diffraction device having a high diffraction efficiency with respect to a wide-band radiation beam. A diffraction device comprises a substrate and a diffraction grating formed on the substrate, wherein the diffraction grating is formed so that a full-width of wavelength at half maximum of a diffraction efficiency of a beam diffracted by the diffraction grating is not less than about 8% of a value of a center wavelength of the diffracted beam.

Abstract: A system for evaluating the head-up display aperture of a vehicle windshield with respect to established optical standards, independently of the projection system with which it is to be utilized. A fixture is provided for mounting a windshield in a predetermined position. An object plate having a series of accurately spaced parallel slits therethrough is positioned so that a light source positioned behind the object plate directs a series of narrow elongated light beams corresponding to the slits against the interior surface of the windshield within the display area. A line scan camera array system scans the display area and produces signals indicative of the apparent positions of the primary and secondary images of the beams reflected by the opposite surfaces of the windshield. The signals are transmitted to and stored within a computer system as a measured data base or map.

Abstract: A waveguide holographic telltale display for displaying images to a vehicle driver via the vehicle windshield. A light source injects light into the base of a clear inner windshield singlet. A mirror hologram between the inner and outer singlets confines a majority of the injected light to the inner singlet. An image hologram between the windshield singlets diffracts light out to the vehicle driver. A halfwave plate between the image hologram and the inner singlet reduces ghosting and allows the driver to view the images even through polarized sunglasses. IR light is blocked by a tinted outer singlet or a holographic solar coating. The display does not suffer from ambient turn from the sun, and the light source is hidden away from the vehicle dash.

Abstract: In a photomagnetic eraser, information recorded on a magnetic-layer of a photomagnetic recording medium is erased or initialized by applying light over the photomagnetic recording medium from a light source in a reflector with heating and also by supplying a magnetic field to the photomagnetic recording medium along its axis of easy magnetization. In one form, a plurality of light sources may be disposed in the concave surface of a single reflector. Alternatively, the photomagnetic recording medium may be double-faced, and the light source and reflector may be disposed on each side of the double-face recording medium.

Abstract: A windshield display system for automobile includes a wavelength selective holographic combiner (12) laminated within the plies (36, 50) of an automobile windshield. A lamination process is provided to prevent degradation of the holographic combiner (12), which might otherwise occur with conventional windshield lamination processes. The holographic combiner (12) is processed in a manner that permits it to withstand the temperature and pressure extremes of the windshield lamination process. Also provided is a display system (60) for producing an image of vehicle information and the motorist's field of view as the motorist observes the real world scene.

Abstract: A hologram includes an optically transparent base plate having first and second opposite surfaces. A hologram element is provided on the first surface of the base plate, and has a predetermined holographic pattern. An optically transparent member has first and second opposite surfaces. The first surface of the member faces the hologram element. An arrangement serves to prevent light, which successively passes through the transparent base plate, the hologram element, and the member and is then reflected at a boundary between the second surface of the member and an atmosphere, from travelling back to the hologram element.

Abstract: A virtual image display system for displaying a relatively large virtual image to a user derived from a relatively small image source. A lens group is provided for amplifying an image provided by the image source. A plurality of reflecting elements are provided for magnifying the image provided by the lens group and for displaying the relatively large virtual image. Several embodiments are provided that include on-axis and off-axis reflecting versions, and a holographic virtual image version. Conventional lenses and reflecting optics are used to provide the on- and off-axis versions of the system, while a holographic reflecting element is used to provide a holographic virtual image. A window element may also be employed to minimize ambient reflection viewed by the user and eliminates ambient reflection to reduce the user's eye fatigue. The display system improves a user's viewing comfort by positioning the image at a distance matching the visual requirements of the user's eye.

Abstract: An information display system has a display screen which is substantially transparent to a selected band of wavelengths of light and can be mounted on a window. A projector projects an image of light of the wavelengths to which the display screen responds onto the screen to reflect or transmit the selected wavelengths of light from the screen. The screen is formed as a holographic optical element which reflects the light such that an observer is able to see the projected image from the display screen only if his eyes are within a predetermined area, while observers outside of the area see only a substantially transparent display screen on the window.

Abstract: A compact, inexpensive and mass-producible optical display system for an automobile creates a highly visible and sharp, high contrast and pleasing, multi-color magnified virtual image of a primary instrument cluster at a viewing distance which is greater than the actual optical distance between the dashboard and the driver's eyes in order to enhance instrument readability, minimize driver eye strain, and reduce eye focus problems which are associated with transitioning between the far range viewing used for watching the road ahead and the near range viewing used for glancing at the instruments. A non-pupil forming display system uses a single off-axis aspherical mirror with power to create a virtual image of a miniaturized, multi-color passive image source, such as a segmented LCD panel, which is backlighted by a small filament incandescent light bulb. The aspheric surface is optimized to minimize aberrations and reduce vertical disparity and field curvature.

Abstract: A holographic display system is disclosed. Utilization of holographic elements provides good transmissivity with respect to both outside stimulus and the superimposed display information. Full color display is enabled by a composite spherical lens and the efficient optical coupling of the display information and the pupil allows the weight of the helmet with the display system to be kept to a minimum.

Abstract: An optical mixer for use in a helmet visual display system including a light intensifier tube for night vision and a cathode-ray tube for the display of a synthetic image. The mixer includes a swinging glass plate with a spectrally reflective and angularly selective coating. When the angle of the swinging glass plate is changed, the amount of light transmitted through the mixer is changed.

Abstract: A guard hologram blocks ambient turn-on of an image hologram. In a center high-mounted rearview stoplight assembly, a guard hologram is used to prevent ambient turn-on by the sun and still allow optical transparency of the image hologram. The guard hologram preferred is optically mounted to the lamp side of the image hologram and includes two 0-degree reflection holograms separated by a halfwave film.

Abstract: A low-cost head-up display suitable for automobiles consists of a transmitting diffractive element (3) located below an observer's line of sight for diffracting light from an information display (2)onto a combiner glass or the windscreen (1) of the automobile, and an opaque mask (4) positioned close to the diffractive (3) element so that specular reflections from the display (2) are screened from the observer's field of view.

Abstract: A waveguide virtual image display including image generation apparatus providing a real image at an inlet of an optical waveguide. The real image being reflected a plurality of times within the optical waveguide by diffractive optical elements that magnify and filter the real image and produce a virtual image at a viewing aperture. The display is mounted on an eyeglasses frame for hands-free viewing.

Abstract: A head-up display for vehicle including a windshield having first and second opposing air interfaces for partially reflecting imaging illumination at a predetermined air interface to produce a primary virtual image viewable by the operator of the vehicle, and a half-wave retarder interposed between the first and second air interfaces of the windshield for rotating the linear polarization of illumination transmitted therethrough. An imaging illumination source provides linearly polarized imaging illumination to the first air interface of the windshield at an angle which is selected to enhance the reflection of S-polarized light and the transmission of P-polarized light, with the polarization being selected so as to provide S-polarized imaging illumination at the predetermined beam splitting air interface.

Abstract: A heads-up display including a holographic optical element which reflects only at least one specific wavelength and allows a background light of other wavelengths to pass therethrough, an information source which emits information light having the specific wavelength, and a device for removing a wavelength of light corresponding to a complementary color of the specific wavelength.

Abstract: A head-up display device comprises an image generator, a beam combiner having a light receiving plane tilted laterally for receiving a light from the image generator and diffracting the light, and a compensator arranged between the image generator and the beam combiner for receiving the light from the image generator by a light receiving plane thereof and directing the light to the beam combiner to correct an aberration created by the beam combiner. The compensator is arranged such that a normal line extending through a center of the light receiving plane thereof and a normal line extending through a center of the light receiving plane of the beam combiner are in a common plane.

Abstract: An indication display unit for vehicles of this invention is provided with a head-up display (HUD), an indication projector, a display device located at the ceiling of the vehicle, and a reflector forwardly located relative to a driver's seat. The indication display unit of this invention further includes a shifting mechanism for the reflector so that when the vehicle speed decreases lower than a predetermined low speed limit, the reflector can be completely shifted away from the driver's visual field. The shifting of the reflector can be accomplished by having the reflector shift in a vertical direction or just outside, but near the driver's visual field, in a horizontal direction.

Abstract: A display unit including an indicator (1) for projecting a predetermined image, an image forming optical system (3) for forming a real image at a predetermined position according to the image projected by the indicator, and a transparent hologram screen (10) disposed at the image forming position of the image forming optical system to diffract the real image in a predetermined direction with a directivity.

Abstract: A lamp arrangement for a motor vehicle comprises a light source including a plurality of bulbs and arranged in a rear shelf panel, and a transmission hologram mounted on a rear window on the cabin side thereof. The transmission hologram includes a plurality of divisions which have different diffraction characteristics from each other. Almost all incident lights from the light source are diffracted by any of the divisions rearward of the vehicle.

Abstract: A helmet system comprising a helmet (11), a vizor (13) pivotally mounted on the helmet, and mounted on the vizor (13), an electro-optical system, e.g. a night vision goggle, including an eyepiece (33) positioned between a transparent part (19) of the vizor and the user's eye so as to provide the user with a view of a scene forward of the user through the eyepiece, the eyepiece also serving as a combiner to provide the user with a virtual image of a display produced by the electro-optical system superimposed on his view of the forward scene through the eyepiece.

Abstract: A holographic objective system (3) produces an intermediate real image (4) of information displayed on an electrically addressable spatial light modulator or SLM (1), the real image (4) being collimated by a powered holographic reflector (5) constructed as part of the visor of a helmet worn by the viewer (9). The SLM (1) is illuminated by laser light from a remote laser (8) via a single optical fibre (6) and beam splitter (2). A diffuser (7) is provided either between the laser and the beam splitter or in the plane of the intermediate image (4). The objective system (3) may alternatively include, or consist entirely of, conventional optical elements.

Abstract: A method of observing information includes the steps of converting a radiation beam into a visible harmonic beam conforming to the information and observing the information by the harmonic beam. An apparatus for observing information therethrough includes a source for producing a radiation beam conforming to the information, and a converter for converting the radiation beam into a visible harmonic beam, with the information being observed with the aid of the harmonic beam. In addition, a head-up display apparatus includes a source for producing a radiation beam conforming to information to be displayed, a converter for converting the radiation beam into a visible harmonic beam, and a beam combiner for receiving the harmonic beam and directing it in a predetermined direction to effect the display of the information by the harmonic beam.

Abstract: The automotive headup display apparatus contains an indicator and a reflection member and has an opening directed toward a reflection surface as on a windshield. A Fresnel lens is installed in the opening for enlarging a display image of the indicator. The reflection member is disposed facing and between the indicator and the reflection surface. The reflection member is coated with a hologram emulsion layer to have a wavelength selection capability such that only the rays of light with almost the same wavelength as display light of the indicator are reflected by the reflection membeer. With this arrangement, when external light should enter the indicator unit from the reflection surface on the windshield, those rays of light different in wavelength from the display light are not reflected toward the indicator, preventing the display of the indicator from being obscured as in the conventional apparatus.

Abstract: The invention relates to a holographic display element which includes a reflection hologram and is attached to, for example, an automobile windshield so as to project light rays carrying images of display information onto the display element from a luminous source in the car. When external light such as sunlight coming is diffracted by the reflection hologram there is a possibility that visible light ranging from 570 nm (greenish yellow) to 780 nm (red) is diffracted into a certain range of angles in a horizontal plane and makes a strange impression on persons viewing the windshield from the outside. According to the invention another reflection hologram having different diffraction characteristics is superposed on the first hologram on the outer side in order that diffraction of visible light into the aforementioned range of angles may become inconspicuous.

Abstract: The present invention has disclosed an indication display unit for a vehicle enabling a driver to sight an indicated image on a windshield thereof comprising, a display device for indicating an image thereon, a light source for projecting light to the above display device, a lens through which the indicated image is projected on the windshield, a light conducting means provided between the display device and the lens, having a light detecting element and a window portion therein, a shutter means for intercepting incident sunbeams or the like rotatably arranged near said light conducting means, and a control means for controlling the shutter means.

Abstract: A windshield (1) for motor vehicles provided with a reflecting arrangement (6) for making optical information or signals visible to the driver of the vehicle; said information or signals being made recognizable in the same field of view as is suitable for the observation of traffic and the road ahead by said driver. According to the invention, the reflecting arrangement (6) is a hologram with the characteristic of a mirror. The angle of reflection .alpha. of the holographic mirror is different from the angle of reflection .beta. of the surface of the glass upon which said hologram is mounted. As a result the rays R' reflected from the surface of the glass do not reach the eye (8) of the observer, whereas the rays R reflected from the holographic mirror do.

Abstract: A method for processing exposed holograms to enhance their thermal stability and enable them to withstand a windshield lamination process is disclosed. The secondary processing procedure entails an optional step of applying a moisture barrier to the hologram, followed by heat stabilizing the hologram and storing it in a relatively low humidity environment. Specifically, the exposed holographic material is heated to a peak temperature of about 135.degree. C. and thereafter cooled to provide a thermally stabilized holographic material that maintains its holographic qualities over a relatively broad range of temperatures.

Abstract: A head-up display for a vehicle, including a primary image reflection hologram supported by a transparent substrate located in the vehicle operator's field of view for the ambient scene in front of the vehicle, a light source for providing playback illumination to the primary image hologram, and a guard hologram in front of the primary image hologram for substantially reflecting ambient illumination that otherwise could spuriously turn on the first reflection hologram, the guard hologram having an angular bandwidth and a spectral bandwidth that are greater than the angular bandwidth and the spectral bandwidth of the primary image hologram, and having an optical density of 2.0 or greater. The guard hologram can be parallel fringe reflection hologram or a slant fringe reflection hologram.

Abstract: The invention relates to a laminated glass panel incorporating therein a hologram sheet. For example, the laminated glass panel is a vehicle windshield in which the hologram sheet is used as a combiner of a head-up display. As adhesive means, the laminated glass panel uses either one sheet or two sheets of polyvinyl butyral resin (PVB) film. In the former case the hologram sheet is interposed between the PVB film and one of the glass plate and shielded from the PVB film by a transparent resin or glass film which prevents the plasticizer contained in the PVB film from transferring to the hologram sheet. In the latter case the hologram sheet is interposed between the two sheets of PBB film and shielded from each PVB film by a transparent resin or glass film having the aforementioned property. By virtue of the shielding of the hologram sheet from the PVB film, the diffraction wavelength of the hologram sheet does not significantly shift from the aimed wavelength.

Abstract: A head-up display having an image source for producing imaging illumination, an optical combiner for partially reflecting the imaging illumination to produce a virtual image of the image source that is viewable by the operator of the vehicle, and a polarizer which can be controllably interposed between the image source and the optical combiner for nighttime use. The polarizer tends to block the illumination that otherwise would produce objectionable ghost images.