Abstract: A system and method onboard an aircraft generates pilot awareness of obstacle clearance during an engine out (EO) go around (GA) situation. The system herein receives inputs from either a pilot selection or aircraft state change indicating a GA below a published missed approach altitude and also receives an input from an engine status monitor indicating an EO situation. As a GA below the published missed approach altitude does not ensure obstacle clearance with an EO, the systems herein generate a pseudo engine out go around procedure (PEOGAP) which calculates a minimum climb gradient maintaining a minimum separation from all obstacles within an area bound by the published missed approach. Once generated, the systems herein display the PEOGAP to the pilot for adequate obstacle separation and pilot awareness.

Abstract: A head-up display for a vehicle, the head-up display including a picture generating unit arranged to generate a picture on a light receiving surface; and an optical system arranged to image the picture, where the optical system includes an input arranged to receive light of the picture; an output arranged to output light forming an image of the picture; a first mirror and second mirror arranged to guide light from the input to the output along an optical path, where the optical path includes a first optical path from the input to the second mirror including a transmission through the first mirror; and second optical path from the second mirror to the output including a reflection off the first mirror.

Abstract: In an optical system of a display device, an image light projecting device emits image light toward a first side in a first direction. A reflective element of a first light-guiding system emits the image light emitted from the image light projecting device toward a second side in the first direction. A first diffraction element having a reflectivity emits the image light emitted from the reflective element toward the first side in the first direction. A second diffraction element having a reflectivity emits the image light emitted from the first diffraction element toward the second side in the first direction and causes the image light to be incident on an eye of an observer. An optical path from the first diffraction element to the second diffraction element is provided in a second light-guiding system.

Abstract: A pad shape for a support assembly is optimized to provide universal fitting characteristics to Head-Mounted Display (HMD) devices. The pad shape enables a display of a single HMD device to be reliably aligned within multiple users' fields-of-view notwithstanding significant variations of shape and size between these users' heads. Optimal positioning of the display within the multiple users' fields-of-view may be achieved by positionally constraining the HMD device against a portion of the head that varies relatively slightly as compared to other portions of the head. The contact pad includes a curved region having a shape defined by a high order polynomial that corresponds to an empirically determined best fit surface. Empirically determining one or both of the best fit surface or the high order polynomial may include aligning a plurality of “forehead” point clouds that map the geometries of a sample set of users' foreheads.

Abstract: A backlight unit includes: a light source unit which outputs coherent light; a first reflection unit including a parabolic mirror; a second reflection unit facing the first reflection unit and including a flat mirror; and a holographic optical element which changes a path of incident light, where a reflection surface of the second reflection unit forms an acute angle with an light incident surface of the holographic optical element, and the coherent light output from the light source unit sequentially passes the first reflection unit, the second reflection unit, and the holographic optical element.

Abstract: Provided is a backlight unit having high optical efficiency and a holographic display device including the backlight unit. The backlight unit includes a light source unit configured to provide a light beam, a first beam expander configured to mix the light beam provided from the light source unit, expand the light beam in a first direction, and output the mixed and expanded light beam as white light, and a second beam expander configured to expand the white light output from the first beam expander in a second direction perpendicular to the first direction and output the expanded white light as surface light.

Abstract: A projection display 210 arranged to display an image to an observer 212 use waveguide techniques to generate a display defining a large exit pupil at the point of the observer 212 and a large field of view, while using a small image-providing light source device. The projection display 210 uses two parallel waveguides 214, 216 made from a light transmissive material. One waveguide 214 stretches the horizontal pupil of the final display and the other waveguide 216 stretches the vertical pupil of the final display and acts as a combiner through which the observer 212 views an outside world scene 220 and the image overlaid on the scene 220. In a color display, each primary color is transmitted within a separate channel R, G, B.

Abstract: A Head Up Display can be utilized to find light from an energy source. The Head Up Display includes a first waveguide having a first input coupler and a first output coupler. The Head Up Display can also include a second waveguide having a second input coupler and a second output coupler. The first waveguide has a first major surface and the second waveguide has a second major surface, which are disposed approximately parallel to each other. The first waveguide and the second waveguide are positioned as a combiner and allowing viewing an outside feed and information from an image source. The first input coupler diffracts light in the first field of view into the first waveguide and light in a second field of view reaches the second input coupler and is diffracted into the second waveguide.

Abstract: Provided is a head-mounted display element, including: a first casing (11) which incorporates therein at least a display element (21), and has a light projection window (11a) for projecting image light from the display element (21); a second casing (12) which incorporates therein an eyepiece optical system (31) with a refractive power, and has a light receiving window (12a) for receiving incident image light projected through the light projection window (11a) and an eyepiece window (12b) for emitting the image light that has passed through the eyepiece optical system (31); and a coupling portion (13) for coupling the second casing (12) to the first casing (11) so as to make adjustable a length of an optical path between the light projection window (11a) and the light receiving window (12a).

Abstract: The welding filter device includes a light sensor, a microprocessor, a liquid crystal display, and a user interface. The light sensor senses light to generate a welding signal and a light source intensity signal. The microprocessor comprises a determining module, a control module, a regulating module, and a storage module. The determining module receives the welding signal and determines whether to activate a welding mechanism. The control module receives the light source intensity signal and outputs a control signal. The liquid crystal display presents a first display status according to the control signal. The user interface is used to generate a setting signal; wherein when the liquid crystal display presents the first display status, the regulating module receives the setting signal to regulate the settings so that the liquid crystal display presents a second display status. Furthermore, a method for controlling the welding filter device is also disclosed herein.

Abstract: An image display apparatus includes: a left-eye light source (101) that outputs a left-eye image constituting an original image in whole or in part; a left-eye deflection unit (104) that deflects, toward a left eye of the user, the left-eye image outputted by the left-eye light source (101); a right-eye light source (110) that outputs a right-eye image constituting the original image in whole or in part; a right-eye deflection unit (107) that deflects, toward a right eye of the user, the right-eye image outputted by the right-eye light source (110); and a control unit (105, 111) that controls the left-eye light source (101) and the right-eye light source (110) such that the left-eye image and the right-eye image are outputted which are different from each other in at least one of pixel position, image shape, image size, image resolution, and display frame rate so that the user can recognize the original image from the left-eye image and the right-eye image by an image fusion effect.

Abstract: A head up display signal processing system is disclosed. The system comprises an image projector for projecting an image onto a screen, the screen being partially reflective and partially transmissive. The system is operable to provide a separate optical element at a plurality of locations upon the screen, wherein each element comprises an optical phase representative of the location of the element upon the screen, such that the combination of optical elements is arranged to produce an optical hologram upon the screen.

Abstract: A video display includes a light signal generator that generates modulated light signals containing video information propagating along an optical guideway. A light-releasing mechanism releases light from the optical guideway in a timed relationship with the modulation of the light signals. A traveling lens propagates in communication with an optical guideway for guiding light released from the optical guideway into selected directions in a timed relationship with a modulation of the light signals.

Abstract: In a holographic heads-up display, a first set of data and a second set of data are provided. A three-dimensional image or scenery displaying the first set of data in a first layer and the second set of data in a second layer are created. The first layer is separated from the second layer by a specified distance. A hologram is determined, which corresponds to a recording of the scenery via a reference beam. A plurality of controllable phase delay elements are set according to the determined hologram. The hologram is reconstructed by illuminating the plurality of phase delay elements using a coherent light source. The light of the reconstructed hologram is directed into the visual field of a driver via a wind screen of a vehicle.

Abstract: An image processing apparatus has a distortion correction processing unit. The image processing apparatus has a distortion correcting range calculating unit that calculates an input image range necessary for distortion correction processing of the distortion correction processing unit. Thus, the corrected image (output image) obtained by the distortion correction processing can be outputted without overs and shorts for the image output range. The distortion is corrected by effectively using input (picked-up) image data, serving as the original data. Further, the distortion including the pincushion distortion, the barrel distortion, and the curvilinear distortion is effectively corrected.

Abstract: A holographic head up display (HUD) for a vehicle to display an image holographically on a curved display surface such as a windshield is disclosed. The HUD can include a spatial light modulator (SLM) to display a hologram, an illumination system to illuminate said displayed hologram, projection optics to project light from said hologram onto said display surface to form said image, and a processor configured to process said image data to generate hologram data for display on the SLM to form said image. The HUD can further include a non-volatile data memory coupled to said processor to store wavefront correction data for said display surface, and the processor can be configured to apply a wavefront correction responsive to said stored wavefront correction data when generating the hologram data to correct the image for aberration due to a shape of said display surface.

Abstract: An image display system for use of a driver in a subject vehicle includes a look area detector for detecting a look area of the driver who watches a real leading vehicle on a transparent glass in a front of the driver and a control unit for controlling display of a transparent image on the transparent glass in the front of the driver for representing a virtual leading vehicle. When the look area detected by the look area detector overlaps at least a portion of the transparent image of the virtual leading vehicle displayed on the transparent glass, the control unit increases a degree of transparency of at least an overlapping portion of the transparent image of the virtual leading vehicle relative to a non-overlapping portion of the transparent image of the virtual leading vehicle.

Abstract: The present invention relates to a three-dimensional (3D) hologram display system. The 3D hologram display system includes a projector device for projecting an image upon a display medium to form a 3D hologram. The 3D hologram is formed such that a viewer can view the holographic image from multiple angles up to 360 degrees. Multiple display media are described, namely a spinning diffusive screen, a circular diffuser screen, and an aerogel. The spinning diffusive screen utilizes spatial light modulators to control the image such that the 3D image is displayed on the rotating screen in a time-multiplexing manner. The circular diffuser screen includes multiple, simultaneously-operated projectors to project the image onto the circular diffuser screen from a plurality of locations, thereby forming the 3D image. The aerogel can use the projection device described as applicable to either the spinning diffusive screen or the circular diffuser screen.

Abstract: The present invention relates to an image display device in which a virtual image of an image display element is formed to display an image. The image display device includes a transmission type diffraction optical element (50) for diffracting exit lights from the image display element (20) and a reflection type optical element (70) having a positive optical power for reflecting the diffracted lights from the transmission type diffraction optical element (50). When the reflected lights reflected by the reflection type optical element (70) are incident again on the transmission type diffraction optical element (50), the transmission type diffraction optical element (50) diffracts the reflected lights with a diffraction efficiency lower than a diffraction efficiency for the exit lights from the image display element (20).

Abstract: The invention relates to a method for calculating a light field which propagates between a non planar surface of a computer-generated hologram and a planar reconstruction surface, in which an intermediate plane arranged in front of the hologram is defined, in which the propagation of the light field between the reconstruction plane and the intermediate plane is calculated by means of a transformation, and in which the propagation of the light field between the non-planar hologram surface and the intermediate plane is estimated. This method solves the technical problem of taking account of the geometrical distance differences that arise on account of unevennesses of the storage medium ill the calculation of the hologram function and the reconstruction or read-out and at the same time of specifying a fast algorithm. The invention also relates to a method for producing a hologram, storage medium and a device for reading out a hologram.

Abstract: Optical elements and methods of forming optical elements are described. In one example, a method applies a photosensitive ink to a substrate and exposes the ink to create an optical element, such as an optical lens or holographic recording medium.

Abstract: A holographic display system for a vehicle includes a projection unit (2), a holographic beam combiner (3), and a viewing mirror (4, 4?). The projection unit includes a light source for the emission of a luminous signal and a controllable imaging unit illuminated by the light source, with which image information can be modulated on the luminous signal. The modulated luminous signal can be directed against the holographic beam combiner. The viewing mirror (4, 4?) is provided in or on the vehicle, by which mirror light radiated from the holographic beam combiner (3, 3?) can be directed into the optical perception range of a user.

Abstract: The light from the image forming element 2 is reflected by the PBS 8, and is incident on the ?/4 plate 7 so that this light is converted into circularly polarized light. Subsequently, the light is subjected to a reflection/diffraction effect and image focusing effect by the reflective type HOE 6. Then, this light again passes through the ?/4 plate 7, and is transmitted through the PBS 8. As a result, the light enters the eye of the user after being synthesized with light from the outside world. The system is devised so that the relationships of ?5<?1<5 and |?1??2|<3 are established between the angle of incidence ?1 (°) at which the principal rays emitted from the center of the display part of the image forming means are incident on the reflective type holographic optical element, and the reflection/diffraction angle ?2 (°) when this light is diffracted/reflected by the reflective type holographic optical element.

Abstract: A viewing optical system for display apparatus, includes an ocular optical member for leading an observation image formed by an observation image forming member to an exit pupil has a first prism member and a second prism member. The first prism member has a first entrance surface, a reflecting surface and a first exit surface disposed to face each other across a first prism medium. The second prism member has a second entrance surface and a second exit surface disposed to face each other across a second prism medium. The first and second prism members are cemented together with a holographic element interposed between the first exit surface and the second entrance surface. The reflecting surface has a positive power. The first exit surface and the second entrance surface are each formed from a plane or cylindrical surface. The holographic element also has a plane of cylindrical surface.

Abstract: An eyepiece optical member introduces into an exit pupil an observation image formed by an observation image forming member. The eyepiece optical member is configured so that a first prism that has a first entrance surface, a reflecting surface and a first exit surface arranged with a first prism medium between and a second prism that has a second entrance surface and a second exit surface arranged with a second prism medium between are joined to each other via a hologram element interposed between the first exit surface and the second entrance surface. The reflecting surface is shaped as a concave surface to give a positive power for rays reflected therefrom. The first entrance surface and the second exit surface are shaped as curved surfaces, respectively, to give a power for rays transmitted therethrough.

Abstract: Disclosed is an optical switch for transmitting or shutting down an input light signal in accordance with a set switching state. The optical switch comprises first and second optical amplifiers connected in cascade. When an optical fiber amplifier comprising EDFs (11 and 12) and pumping sources (31 and 32) is used as the first and second optical amplifiers, the switching is accomplished by switching on or off the pumping sources (31 and 32) in accordance with control signals supplied from a control circuit (300). One input light signal can be dropped through a first optical branch (51) located on the input side of the optical switch, while another input light signal can be added through a second optical branch (53).

Abstract: The invention relates to a light indicator, comprising an indicator element (2) illuminable by a light source (1). The indicator element is manufactured from a substantially transparent material provided with an informative indicator pattern. The indicator element (2) is designed as a waveguide panel, wherein light beams propagate with total reflection and get outcoupled therefrom with a diffractive outcoupling system (2u), such as a grating structure or the like, which is configured as an indcator pattern, for producing an indicator pattern (2a) activable in the indicator element (2) by the action of light, such that divergent recesses and/or grooves of various sizes and/or shape constitute divergent local gratings of various sizes and/or shapes, such as multi-shaped and/or binary pixels and/or units, the filling factor, shape, profile and/or size thereof being optimized in such a way that the difraction efficiency is a function of place.

Abstract: An imaging system for motor vehicles has a holographic screen, which scatters incident narrow band light at a predetermined solid angle, and a modulator and a lens to project images on the holographic screen. A holographic, transparent ray uniter, which allows broad band ambient light to pass through essentially unimpeded, guides the narrow band light, coming from the holographic screen to the viewer, whereby a virtual image is produced at the viewing location by means of an imaging function. Images from the outside of the motor vehicle are shot by means of a camera system and are faded as virtual images into the windshield of the motor vehicle in order to enable there additionally a view to the rear or to the side.

Abstract: A viewing optical system for display apparatus, includes an ocular optical member for leading an observation image formed by an observation image forming member to an exit pupil has a first prism member and a second prism member. The first prism member has a first entrance surface, a reflecting surface and a first exit surface disposed to face each other across a first prism medium. The second prism member has a second entrance surface and a second exit surface disposed to face each other across a second prism medium. The first and second prism members are cemented together with a holographic element interposed between the first exit surface and the second entrance surface. The reflecting surface has a positive power. The first exit surface and the second entrance surface are each formed from a plane or cylindrical surface. The holographic element also has a plane of cylindrical surface.

Abstract: An alignment detector is disclosed that determines whether a first element has been moved to a predetermined position relative to a second element. The detector includes an emitter that is secured within a first optical chamber. A first detector is secured within a second optical chamber. The first optical chamber is optically connected to the second optical chamber such that a signal emitted from the emitter is detectable by the detector. An occluding element at least partially obstructs the signal when the first element has been moved to the predetermined position.

Abstract: A holographic display device, e.g. for a vehicle, which reduces a color of hologram reflection toward the outside of the vehicle or a color of hologram transmission toward the inside of the vehicle generated at a hologram installation portion of a wind-proof glass, and which further reduces an external light noise. Light from a display element is transmitted through an imaging optical component to form a display image on a transmission diffusion hologram provided to a wind-proof glass, and the display image is reflected on the surface on the vehicle outer side of the wind-proof glass for visual recognition by an observer. The above transmission diffusion hologram is produced by diffused light, which is transmitted through a diffusion optical component, being made to fall on one side of a hologram photosensitive material.

Abstract: A viewing optical system for display apparatus allows observation of a bright displayed image favorably corrected for aberrations and is easy to assemble, resistant to impact such as vibration, lightweight and compact. An ocular optical member for leading an observation image formed by an observation image forming member to an exit pupil has a first prism member and a second prism member. The first prism member has a first entrance surface, a reflecting surface and a first exit surface disposed to face each other across a first prism medium. The second prism member has a second entrance surface and a second exit surface disposed to face each other across a second prism medium. The first and second prism members are cemented together with a holographic element interposed between the first exit surface and the second entrance surface. The reflecting surface has a positive power. The first exit surface and the second entrance surface are each formed from a plane or cylindrical surface.

Abstract: An optical system invention is interposed between a pupil plane and an image plane, and includes a first prism, a second prism, and a holographic element which is sandwiched between the first prism and the second prism and is cemented to these prisms. When a light beam traveling along the optical path connecting the pupil plane and the image plane through the optical system is called a first beam, the first prism has a 1-1 surface placed on the pupil side, combining the function of transmission with the function of reflection of the first beam; a 1-2 surface placed on the opposite side of the pupil with respect to the 1-1 surface; and a 1-3 surface placed on the image side, transmitting the first beam. The second prism includes a 2-1 surface having the same shape as the 1-2 surface and placed opposite thereto, transmitting the first beam at least twice, and a 2-2 surface placed on the opposite side of the pupil with respect to the 2-1 surface of the second prism, reflecting the first beam.

Abstract: An image display device for displaying a combined image by combining an virtual image with an external object, has a reflective type hologram combiner having an optical power for forming a surface optically equivalent to the external object at a position different from the external object, an image display for displaying an image to be provided as the virtual image at the position of the surface formed by the optical power of the combiner, and a selection surface for selectively reflecting and transmitting an image light from the image display and an external light from the external object. In the image display device, the image light is reflected by the selection surface, reflected by the hologram combiner, transmitted through the selection surface, and thereafter directed to the pupil of an observer, while an external light is transmitted through the hologram combiner, transmitted through the selection surface, and thereafter directed to the pupil of the observer.

Abstract: A method for fabricating an error-free linear position encoder incorporates the generation of fringes on a holographic plate by the interference of light from two point sources. The fringes are projected onto a curved holographic plate without intervening optical elements, the curve being such that the fringes have a constant pitch along the surface of the plate. A methodology for generating such a curve includes the creation of a graphic representation of the hyperbolic fringes generated by the interference between two coherent point sources, which would fall on an appropriately curved holographic plate. A numerical technique derived from the graphic representation produces a “constant-pitch” curve such that all of the fringes projected onto the curve are equidistant. The holographic plate, coated with a photosensitive material, is fabricated or formed in the shape of the constant-pitch curve.

Abstract: In an optical system used for observing a virtual image, in which a Lippman volumetric hologram is used as a reflection type holographic optical element, the generation of aberration needs to be minimized to enable an optimum virtual image to be viewed. To this end, at least one optical element and the Lippman volumetric hologram 10 are provided for cooperating to form a virtual image of the display image on an image display device 6. The Lippman volumetric hologram 10 is contoured so that its curvature is in the same direction as the curvature of interference fringes operating for generating a refractive power in this Lippman volumetric hologram 10.

Abstract: A method is provided for the manufacture of a holographic eye-covering article, the eye-covering article having an interference pattern corresponding to a predetermined three-dimensional object holographically prerecorded in a planar hologram layer, the interference pattern capable of being "played back" to an observer without being "played back" to said bearer. Functionality of the eye-covering article is effected in part by a light transmissive eyepiece, the eyepiece being uniaxially-curved and preferably comprising in sequence a thin web, a planar layer comprising the holographically prerecorded interference pattern, an adhesive layer, and a rigid optical substrate.

Abstract: A system which enables a film, e.g. a photosensitive material film, to be continuously laminated on and delaminated from a surface of a substrate, e.g. a hologram original plate, and allows duplication to be continuously effected. The system includes a film supply part (32) for supplying a film (1), a film laminating part (37) for continuously laminating the supplied film (1) on a film laminating substrate (35), a film delaminating part (37') for continuously delaminating the film from the substrate (35), and a film take-up part (43) for taking up the delaminated film. In the system, no air bubbles are trapped when the film (1) is laminated on the substrate (35), and no peel unevenness, e.g. undesired line, occurs when the film (1) is delaminated from the substrate (35). The system is suitable for use in a hologram duplicating apparatus, a dimple relief pattern duplicating apparatus, a microscopic test sample preparing apparatus, etc.

Abstract: A wide field-of-view simulator heads-up display provides images to a user along an optical axis. A HUD CRT provides images of a predetermined design wavelength, while rear projection screen CRTs provide out-of-window scenery that does not contain the predetermined design wavelength. A curved holographic combiner is mounted on the optical axis with a reflective hologram on a concave surface covered with a urethane overcoat. The convex surface has an antireflective coating. A tilted beamsplitter cooperates with a folding mirror in a relay optical system for providing a virtual image of the HUD CRT for reflection from the holographic combiner.

Abstract: A holographic stoplight system that includes a stoplight hologram (21, 21') supported adjacent the inside surface of a rear window (211) of a vehicle, and a light source (29, 31) for providing a converging beam that is vertically converging and predominantly horizontally colimated. The stoplight hologram is illuminated with the vertically converging beam, or with a predominantly collimated beam provided by a collimating lens (27) that collimates the vertically converging beam.

Abstract: A heads-up display unit provided with a display device serving as display image forming means which displays a display image. A hologram serves as a reflecting means, and reflects the display light emitted from the display device, causing reflection of the display image on the interior surface of a vehicle's windshield. A display image is formed outside the windshield towards the front of the vehicle. A concave mirror having a different focal length in different directions is recorded in the hologram serving as a reflecting means so as to offset distortion of the display image caused by curvatures of the windshield. This construction makes it possible to cause the windshield to display a display image free from distortion.

Abstract: A system which enables a film, e.g. a photosensitive material film, to be continuously laminated on and delaminated from a surface of a substrate, e.g. a hologram original plate, and allows duplication to be continuously effected. The system includes a film supply part (32) for supplying a film (1), a film laminating part (37) for continuously laminating the supplied film (1) on a film laminating substrate (35), a film delaminating part (37') for continuously delaminating the film from the substrate (35), and a film take-up part (43) for taking up the delaminated film. In the system, no air bubbles are trapped when the film (1) is laminated on the substrate (35), and no peel unevenness, e.g. undesired line, occurs when the film (1) is delaminated from the substrate (35). The system is suitable for use in a hologram duplicating apparatus, a dimple relief pattern duplicating apparatus, a microscopic test sample preparing apparatus, etc.

Abstract: A head-up display includes a projector which projects an image light and a hologram lens which diffracts and reflects the projected image and form a virtual image located ahead of a windshield. The hologram lens has a vertical diffraction characteristic which is equivalent to a hyperbolic or parabolic-curve mirror along a line formed by the intersection of the hologram lens and a vertical plane which includes an axis of the image light and a horizontal diffraction characteristic which is equivalent to a parabolic or elliptic curve mirror along a line which is formed by the intersection of the hologram lens and a horizontal plane which includes the axis of the image light. When the hologram is directly attached on a curved windshield which has a focal length fs (in case it is a mirror), the focal length fo of the hologram and the former focal length fs has the following relationship; 1/fo=1/fh+1/fs, where fh is a focal point when the hologram is flat.

Abstract: A hologram display apparatus in which chromatic aberration hardly occurs even when light of a wide bandwidth is used as a reproducing light. The apparatus has a hologram combiner 10 with a diffraction characteristic of lens, and is adapted to receive a signal light including information to be displayed and to generate, in response to the signal light, a reproduced light to be seen and acknowledged by an observer. The hologram combiner 10 has a curved surface with a constant curvature in at least one of a first direction and a second direction perpendicular to the first direction. The center 01 of curvature of the curved surface is positioned at substantially the same position of the center 02 of curvature of the lens equivalent to the hologram 11.

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 helmet display system is provided comprising a display visor 3 located on helmet 1 on which helmet is also positioned image projection means for projecting an image via a holographic combiner 4 on the display visor 3. The helmet further comprises an anti-glare visor 2 which has optical transmission characteristics similar to those of a neutral density visor, with the exception that these characteristics are modified to compensate for the low transmission value of the display visor 3 to frequencies within a narrow waveband to which the combiner 4 is tuned. The invention provides a helmet display system which can be used in conjunction with an aircraft head-up display if required.

Abstract: A head-up display for an automobile utilizing a light transmission hologram optical device as well as a light reflection hologram optical device. The head-up display is installed in a large truck or in a special freight car, such as a container car or a ready mixed concrete car, so that the head-up display informs a driver of information of conditions of dead ground of the car. The head-up display includes a hologram optical projection system and a holographic combiner. The projection system for projecting the light has a light source, an LCD for partially transmitting and shielding the light of the light source, and a light transmission hologram optical device for projecting the light. The holographic combiner for displaying the image includes a light reflection hologram optical device.

Abstract: A space light modulating apparatus and a stereoscopic display apparatus which are used in a rewritable hologram stereoscopic display. A solid image can be properly displayed by a phase distribution of a low spatial frequency. A plurality of flat space light modulating units, each having a predetermined area for performing a wave front conversion while setting a position near the position of a cross point (center position) of a normal line from a virtual display surface of a non-flat shape to display the phase distribution into a producing position of a solid image, are arranged along the virtual display surface such as a cylindrical surface or a spherical surface.

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.