Abstract: A holographic optical element comprising at least two sets of regions, the regions of each set being different from the regions of the other set(s) and being interleaved or overlapping with the regions of the other set(s) and being constructed such that light incident on each set of regions is directed to a respective one of a plurality of viewing zones. The holographic optical element is typically incorporated in a display device such as a stereoscopic display device.

Abstract: A real-time, dynamic, free space-virtual reality, 3-D image display system which is enabled by using a unique form of Aerogel as the primary display media. A preferred embodiment of this system comprises a 3-D mosaic topographic map which is displayed by fusing four projected hologram images. In this embodiment, 4 holographic images are projected from 4 separate holograms. Each holographic image subtends a quadrant of the 4&pgr; solid angle. By fusing these four holographic images, a static 3-D image such as a featured terrain map would be visible for 360 degrees in the horizontal plane and 180 degrees in the vertical plane. An input, either acquired by 3-D image sensor or generated by computer animation, is first converted into a 2-D computer generated hologram (CGH). This CGH is then downloaded into large liquid crystal (LC) panel. A laser projector illuminates the CGH-filled LC panel and generates and displays a real 3-D image in the Aerogel matrix.

Abstract: A system and a method of displaying projected images on a projection screen of the system include one or more reconfigurable holographic optical elements (HOEs) in the screen to optically manipulate the projected images impinging on the screen. The reconfigurable HOEs may be configured to perform simple optical functions that are commonly associated with traditional optical devices, such as lenses, prisms and mirrors. However, the reconfigurable HOEs may also be configured to perform sophisticated optical manipulations, such as varying angular intensity of diffused light toward predefined viewing regions. Each reconfigurable HOE includes a hologram that is sandwiched between two electrode layers. The hologram is a holographic photopolymeric film that has been combined with liquid crystal. The hologram has an optical property that changes in response to an applied electrical field. The reconfigurable HOEs are utilized to control the diffusing characteristic of the projection screen.

Abstract: A holographic stereogram printing apparatus that is able to formulae a holographic stereogram superior in light utilization efficiency and in picture uniformity. The holographic stereogram printing apparatus causes the laser light from a laser light source 31 to fall on a picture display device 41 to illuminate the light transmitted through the display device 41 as object light on a holographic recording medium 30. The holographic stereogram printing apparatus also causes part of the laser light prior to being transmitted through the display device 41 to be illuminated as reference light on the holographic recording medium 30 to form the element holograms sequentially on the holographic recording medium 30. In the holographic stereogram printing apparatus, a light integrator 63 for uniforming the intensity of light incident on the display device 41 is provided on the optical path of the laser light proceeding towards the display device 41.

Abstract: A display device with a holographic diffuser which has at least first and second adjacent sets of holographic regions which overlap each other and wherein the first and second holographic regions diffract and direct light to respective first and second sets of imaging elements of a lcd to displays an image.

Abstract: A method and apparatus for making holograms includes a technique for exposing a film substrate or other light-sensitive medium to consecutive two dimensional images, together representative of a physical three-dimensional system, to generate a three dimensional hologram of the physical system. Low beam ratios are employed to superimpose multiple (20-300) images on the substrate. Each image is relatively weak, but the combination of the series of weak images ultimately appears as a single clearly defined hologram.

Abstract: An image data generating method for generating image data corresponding to a planar holographic stereogram is provided. First, an object or imaging device is rotated, while the distance between the object and the imaging device is kept substantially constant, for shooting plural images of different viewing angles by the imaging device. The image data of plural images is then corrected for keystone distortion. The image data corrected for keystone distortion is then processed with viewing point conversion processing for converting the viewing point for generating image data of images recorded on the holographic stereogram. In addition, image data including the information for plural images is compressed for storage in the internal storage device of the computer.

Abstract: An autostereoscopic display system and a method of displaying a scene in a stereoscopic form on a screen of the system include two or more reconfigurable holographic optical element (HOE) stacks in the screen. The reconfigurable HOEs may be configured to perform simple optical functions that are commonly associated with traditional optical devices, such as lenses, prisms and mirrors. However, the reconfigurable HOEs may also be configured to perform sophisticated optical manipulations, such as optimally diffusing light with respect to light intensity toward a predefined viewing region. Each reconfigurable HOE includes a hologram that is sandwiched between two electrode layers. The hologram is a holographic photopolymeric film that has been combined with liquid crystal. The hologram has an optical property that changes in response to an applied electrical field.

Abstract: The present invention is an apparatus and method for displaying large, continuous, autostereoscopic images. The present invention overcomes the size limitation of typical autostereoscopic images by recording a continuous, autostereoscopic image onto separate sheets or segments of recording material, mounting the recorded segments to separate tiles, and then displaying the tiles to display a continuous, autostereoscopic image. Although the autostereoscopic image display of the present invention is comprised of separate segments, the present invention offers viewers of the display a unitary visual impression of a large, autostereoscopic image without apparent discontinuities.In one broad aspect, the present invention provides a system for easily displaying segments of recording material to form a large, continuous, autostereoscopic image. The display can be disassembled into components that are light, compact, easily transportable, and easily storable.

Abstract: A projection system and a method displaying a high resolution composite image on a projection screen include a number of reconfigurable holographic optical elements (HOEs) in the projection optics of the system. The reconfigurable HOEs of the projection optics allow the system to direct multiple image segments of the composite image that are projected from a single image source toward different regions of the projection screen to form the composite image on the screen. The image segments have a high resolution due to the fact that they have been magnified by a relatively small degree. Consequently, the displayed composite image formed by the image segments has an equally high resolution. Each reconfigurable HOE includes a hologram that is sandwiched between two electrode layers. The hologram is a holographic photopolymeric film that has been combined with liquid crystal. The hologram has an optical property that changes in response to an applied electrical field.

Abstract: The invention is intended to provide a three-dimensional image projecting device which is capable of presenting a three-dimensional image observable in a wide visual field without tiring eyes of an observer. A three-dimensional image displayed by three-dimensional image displaying means is projected by a reflection type projecting hologram lens and reflection type hologram acting as optical transferring means and a reflection type hologram lens to produce respective three-dimensional images. These three-dimensional images are formed at the same magnification in the same space to form a continuous image area. For this purpose, reflection type hologram lenses are disposed on the periphery of a circle. Respective three-dimensional images is reflected by the reflection type hologram acting as the optical transferring means, thus an enlarged three-dimensional image can be seen over the respective visual fields.

Abstract: A three-dimensional image is reproduced by unit 3. For that purpose, the interference pattern on carrier 8 is illuminated by source 7 of noncoherent reproduction radiation. The process is that of illuminating the first interference structure 5, which is optically coupled with the interference pattern, or the second interference structure 9, the principle of spatial filtration of which corresponds to the principle of spatial filtration of the first interference structure 5 and the scale of which corresponds to the scale of the interference structure illuminated. The beams are extracted the intensities, spatial positions and directions of which correspond to the intensities, spatial positions and directions of the beams that were registered in recording the interference pattern, i.e., the beams are extracted which correspond to the independent spatial coordinates .alpha. and .beta.. The set of these beams corresponds to a three-dimensional image of object 4, which is indistinguishable from the real image.

Abstract: To produce a rainbow-type holographic stereogram, an object beam is focused in the vertical direction with a cylindrical Fresnel lens. On the other hand, according to the edge-lit scheme, a reference beam is applied to a hologram recording medium via a light introduction block. A color holographic stereogram can be produced by utilizing a phenomenon that the color of a reproduction image is varied by moving the cylindrical Fresnel lens by a proper distance in the vertical direction.

Abstract: A liquid crystal spatial light modulator comprises columns and rows of picture elements. The columns are arranged as groups of columns, for instance under respective parallax generating elements in an autostereoscopic 3D display. The picture elements are arranged as sets to form color picture elements such that the picture elements of each set are disposed at the apices of a polygon, such as a triangle, and are disposed in corresponding columns of the groups of columns.

Abstract: An image reproducing method and apparatus whereby an image with a wide angle of visibility can be reproduced from a holographic stereogram in a manner less susceptible to blurring. For reproducing an image from a holographic stereogram 80 of an edge lit system, a holographic stereogram 80 is arranged on a lateral side of a cylindrically-shaped light-introducing block 81 and a reproducing illuminating light beam 82 is illuminated on the holographic stereogram 80 via the light-introducing block 81. A reproduced image 85 is produced by a diffracted light beam obtained on diffraction of the reproducing illuminating light beam 82 transmitted through the holographic stereogram 80.

Abstract: The liquid crystal display device according to this invention realizes three-dimensional picture images without using lenticular lenses etc. In addition, this liquid crystal display device has a transparent picture screen so that remote display picture images or three-dimensional picture images of high luminance are seen multiplexed with the background. The display device is constructed by arranging picture elements in which volume-phase type holograms are formed by a periodical construction of liquid crystals and polymers. Diffraction light from first picture element groups which are distributed uniformly reaches a left eye of an observer while diffraction light from second picture element groups which are distributed uniformly reaches a right eye of an observer. The condition of the picture elements are switched to diffract irradiated light or to transmit the light, thus a desired picture image comprising a dot matrix can be displayed.

Abstract: A method and apparatus for correlating outputs of a plurality of environmental sensor signals to determine a situation. The method includes the steps of dividing a coherent light beam across a diameter of the light beam into a plurality of information transmission zones and modulating a portion of the light beam within at least some of the information transmission zones with a corresponding number of signals of the plurality of environmental sensor signals. The method further includes the steps of deflecting the modulated light beams of the at least some information transmission zones within a holographic memory to provide at least some correlated outputs among the plurality of environmental sensor signals and determining the situation based upon the at least some correlated outputs of the holographic memory.

Abstract: A method and an apparatus for creating a holographic stereogram are provided for canceling noises localized to infinity and offering a high-quality hologram. The creating method is executed to display an image corresponding to a coordinate location on the hologram recording medium on the display unit, condense the laser beam transmitted through the display unit as an object beam at the coordinate location of the hologram recording medium, and apply part of the laser beam before transmission through the display unit as a reference beam onto the hologram recording medium, for sequentially forming stripped or dotted holographic elements on the hologram recording medium. The creating apparatus includes a first diffuser panel located close to the display unit, a mask, and a second diffuser panel, the latter two of which are located immediately before the hologram recording medium. The mask has an opening corresponding to the width of the holographic element.

Abstract: According to the invention, a method to process heart motion image data into a portable display medium is provided. An image sequence of heart motion is provided. Image sequences are incorporated in angularly multiplexed holograms so that the parallax, i.e. the relative position of observer and holographic medium, encodes heart motion. This way, a change in the viewing angle of the printed hologram leads to the perception of the complete heart cycle. Using this technique, it is possible to incorporate a complete temporal image sequence of the beating human heart to a single printable image which can be used for display, storage, documentation and reporting.

Abstract: The liquid crystal display device according to this invention realizes three-dimensional picture images without using lenticular lenses etc. In addition, this liquid crystal display device has a transparent picture screen so that remote display picture images or three-dimensional picture images of high luminance are seen multiplexed with the background. The display device is constructed by arranging picture elements in which volume-phase type holograms are formed by a periodical construction of liquid crystals and polymers. Diffraction light from first picture element groups which are distributed uniformly reaches a left eye of an observer while diffraction light from second picture element groups which are distributed uniformly reaches a right eye of an observer. The condition of the picture elements are switched to diffract irradiated light or to transmit the light, thus a desired picture image comprising a dot matrix can be displayed.

Abstract: A hologram of a virtual object or an object which actually exists is formed and a solid image is displayed. 3-dimensional information of the object to be displayed is divided into regions in the depth direction. Depth images are formed as 2-dimensional images where are seen from a plurality of points which are obtained by finely dividing the hologram forming surface for every region. A phase distribution at the hologram forming surface is calculated from the depth images and displayed on a liquid crystal display or the like as an electronic hologram. A reference light is irradiated onto the display and is converted into an optical wave front, thereby displaying a solid image. When forming a hologram recording medium, a zone image corresponding to each of the finely divided exposure regions of a dry plate is exposed multiple times.

Abstract: An autostereoscopic display includes a projection system which generates a plurality of real images that represent different spatial views of an object and further includes a plurality of contiguous field lenses. From the real images, the field lenses form a plurality of exit pupils which are separated by one interpupillary distance. An observer can "walk around" the display and observe different stereoscopic views of the object by positioning his eyes at an adjacent pair of exit pupils.

Abstract: Computer-processed or computer-generated objects can be used to build holograms whose images are close to or straddle the hologram surface. No preliminary or first hologram is required. The hologram is built up from a number of contiguous, small, elemental pieces. Unorthodox views from inside the object are required for the creation of these elements. One method of generating the views employs unique object manipulations. The computational transformations ensure that no singularities arise and that more-or-less conventional modeling and rendering routines can be used. With a second method, a multiplicity of conventional object views are collected. Then, all pixels in these conventional viewplanes are reassigned to new and different locations in the new viewplanes for the elemental views. These methods may be used to build rainbow holograms or full parallax holograms. When properly executed they are visually indistinguishable from other types.

Abstract: In a method and apparatus for displaying a stereoscopic image, a plurality of 2-dimensional images having parallaxes in only horizontal directions are obtained and inputted when an object to be displayed is seen from different positions in the horizontal direction. The 2-dimensional image is divided in the vertical direction into 1-dimensional line images which are elongated in the horizontal direction. A phase distribution of a corresponding hologram segment is calculated from the pixels of the line image. The calculated phase distribution is displayed on a hologram forming surface of a phase displaying section using a display. A reproduction light is irradiated and converted into an optical wave front and is further enlarged in the vertical direction, thereby displaying a solid image. The 2-dimensional images are inputted by photographing the object by a plurality of cameras arranged in the horizontal direction.

Abstract: A display method for producing a plurality of different views of an object scene simultaneously is provided. A series of two-dimensional projections of an object is produced for the plane of a display device. Wavefront interference information, independent of the two-dimensional projections is produced for an intermediate plane. The two-dimensional projections and the wavefront interference information are combined to create a diffraction grating in the display device to provide a holographic image of the object scene from a number of positions relative to the display device.

Abstract: A holographic stereogram which includes a plurality of element holograms and which reproduces a stereoscopic image by irradiation of coherent light, wherein each element hologram is loaded with a modulation value (pattern) corresponding to the stereoscopic image, the modulation value being a one-dimensional or two-dimensional transform coefficient obtained by one-dimensional or two-dimensional cosine transform or discrete cosine transform of the distribution of the intensity of diffraction light expressing the stereoscopic image, enabling simplification of the drive system of the display device displaying the stereoscopic image and reproduction of the original stereoscopic image much more faithfully.

Abstract: A product, method, and apparatus are provided for making a stereoscopic hologram from a series of two-dimensional views of an object. The two-dimensional views are obtained from, for example, computer analysis of scans taken by standard medical diagnostic equipment. The views are reproduced on an LCD screen, and the screen then serves as the modulator of the holographic object beam. An exposure of each view is sequentially made on a different section of a holographic recording medium, which may be, for example, a photopolymer placed on a substrate. As the observer views the finished product, each eye looks at a different section of the hologram, thus providing a stereoscopic effect.

Abstract: In a display section, a plurality of pixels of minimum display units to display a hologram phase distribution are arranged to thereby construct a cell to display one pixel of a 2-dimensional image, and cells are further two-dimensionally arranged to thereby construct a display image plane. 2-dimensional image data and hologram phase distribution data from an input section are given to a display data forming section. Corresponding 2-dimensional image data and a hologram phase distribution are displayed in a display region of a display section, thereby producing hologram data for allowing a solid image to be recognized by the optical wave front conversion. A display control section executes a display control for allowing the 2-dimensional image data and hologram data from the display data forming section to be displayed in the display section.

Abstract: The liquid crystal display device according to this invention realizes three-dimensional picture images without using lenticular lenses etc. In addition, this liquid crystal display device has a transparent picture screen so that remote display picture images or three-dimensional picture images of high luminance are seen multiplexed with the background. The display device is constructed by arranging picture elements in which volume-phase type holograms are formed by a periodical construction of liquid crystals and polymers. Diffraction light from first picture element groups which are distributed uniformly reaches a left eye of an observer while diffraction light from second picture element groups which are distributed uniformly reaches a right eye of an observer. The condition of the picture elements are switched to diffract irradiated light or to transmit the light, thus a desired picture image comprising a dot matrix can be displayed.

Abstract: A hologram of a virtual object or an object which actually exists is formed and a solid image is displayed. 3-dimensional information of the object to be displayed is divided into regions in the depth direction. Depth images are formed as 2-dimensional images where are seen from a plurality of points which are obtained by finely dividing the hologram forming surface for every region. A phase distribution at the hologram forming surface is calculated from the depth images and displayed on a liquid crystal display or the like as an electronic hologram. A reference light is irradiated onto the display and is converted into an optical wave front, thereby displaying a solid image. When forming a hologram recording medium, a zone image corresponding to each of the finely divided exposure regions of a dry plate is exposed multiple times.

Abstract: A stereoscopic image information transmission system which combines into one unit the information source coding means of the stereoscopic image, which was indispensable at the transmission side in conventional systems, and the interference fringe generating means, for generating the interference fringes expressing the stereoscopic image, into one by an image processing means utilizing a specific conversion rule effective for information compression, whereby it becomes possible to eliminate the information source decoding means which had been required at the reception side in conventional systems, which system thereby enables the hardware on the transmission side to be made much smaller and which enables the load on the transmission line from the transmission side to the reception side to be lightened.

Abstract: A remote controlled locking system employing a holographic window display, particularly adapted for vehicle use. The system includes a remotely-operated transmitter for transmitting locking and unlocking signals, and a locking mechanism that is locked and unlocked in response to the transmitted signals. The locking mechanism outputs a status signal or status signals, corresponding to at least one of the locking and unlocking signals. Control electronics process the status signals from the locking mechanism to provide control signals that are coupled to first and second light emitting members, such as LED arrays. The light emitting members produce light output signals in response to the control signals. First and second prism couplers are attached to a surface of a window and are optically coupled to the first and second light emitting members. First and second hologram decals that comprise the holographic window display are attached to the surface of the window and are responsive to the light output signals.

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 method of using a display system having a spatial light modulator (14) to display holographic images. The spatial light modulator (14) generates images that represent vertical strips of a hologram. These images are de-magnified by a three-dimensional optics unit (18), in the horizontal direction so as to form image strips. A scanning mirror (45) scans the image strips in a series across an image plane at a rate sufficiently fast that the viewer perceives a composite hologram comprised of these image strips.

Abstract: A display system arranged closer than the focus point of the eyes. The display system comprises a hologram carrier for generating a virtual image by a hologram of a pixels' image arranged in two dimensions a light source for directing an incident light of a predetermined wavelength area to the hologram carrier, and a liquid crystal shutter selectively releasing and cutting-off an area of each pixel's image of the hologram carrier.

Abstract: A hologram of a virtual object or an object which actually exists is formed and a solid image is displayed. 3-dimensional information of the object to be displayed is divided into regions in the depth direction. Depth images are formed as 2-dimensional images where are seen from a plurality of points which are obtained by finely dividing the hologram forming surface for every region. A phase distribution at the hologram forming surface is calculated from the depth images and displayed on a liquid crystal display or the like as an electronic hologram. A reference light is irradiated onto the display and is converted into an optical wave front, thereby displaying a solid image. When forming a hologram recording medium, a zone image corresponding to each of the finely divided exposure regions of a dry plate is exposed multiple times.

Abstract: A plurality of 2-dimensional images of different visual directions, when an object to be displayed is seen from different directions, are inputted to an input section by photographing an object using cameras. The 2-dimensional images are then subjected to enlargement, reduction, and movement of the coordinate position, thereby adjusting the size and position of the solid image. A phase distribution at a hologram forming surface is then calculated by a phase calculating section. The phase distribution is calculated from a plurality of 2-dimensional images of red, green, and blue components, and the reproduction light of each color is irradiated, thereby displaying a color solid image. The calculated phase distribution is expressed on a hologram forming surface of a phase expressing section using a display. A reproduction light is then irradiated and converted into an optical wave front, to thereby display a solid image.

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: A diffraction light modulated by a plane type phase distribution display device is deflected by an image formation optical system and is formed as an image onto a cylindrical screen surface and is diffused in the vertical direction by a unidirectional light diffusing section such as a lenticular lens or the like, so that a stereoscopic image can be seen. As a phase distribution display device, a liquid crystal device having pixels on the order of the wavelength in the circumferential direction and having coarse pixels in the radial direction is used. Thus, it is equivalent to that the phase distribution display device is located on the cylindrical surface. A cylindrical stereoscopic display can be performed by using the plane phase distribution display device.

Abstract: A display device which is capable of producing a plurality of different views of an image simultaneously is provided. The display includes an array of semiconductor devices with an electro-optical material disposed over the array of semiconductor devices. The semiconductor devices include electrodes which are selectively activated to form refraction gratings in the electro-optical material. Each of the semiconductor devices also includes a processor layer which can determine a refraction grating which is necessary for generating a predetermined number of discrete images which are visible from a predetermined number of different vantage points or viewer positions. Since a different image is provided to each eye, the viewer is provided with a perception of depth such that a three-dimensional image is provided. In addition, since different images or at least different image perspectives are provided to different points, horizontal and/or vertical parallax of the display is attained.

Abstract: 055745798Heads-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 hologram of a virtual object or an object which actually exists is formed and a solid image is displayed. 3-dimensional information of the object to be displayed is divided into regions in the depth direction. Depth images are formed as 2-dimensional images where are seen from a plurality of points which are obtained by finely dividing the hologram forming surface for every region. A phase distribution at the hologram forming surface is calculated from the depth images and displayed on a liquid crystal display or the like as an electronic hologram. A reference light is irradiated onto the display and is converted into an optical wave front, thereby displaying a solid image. When forming a hologram recording medium, a zone image corresponding to each of the finely divided exposure regions of a dry plate is exposed multiple times.

Abstract: The position of a solid image which changes with the elapse of time is detected. The position of a virtual screen is set so that a distance from an object enters an allowable range such as to reduce a fatigue of an observer. A 2-dimensional image is formed at the set virtual screen position. A phase distribution is calculated at the hologram forming surface, thereby displaying a solid image. Even when the position of a solid image changes with the elapse of time, the fatigue of the eyes can be minimized.

Abstract: An inexpensive electronic display that presents 3D images by binocular parallax is disclosed. The effect produced is that of a real-time holographic stereogram. The pixels of a 2D display are spatially multiplexed by two HOEs to produce a plurality of lateral viewing zones of 2D rasters, similar to the method used in lenticular screen systems. A directional screen HOE scatters incident light over a lateral viewing zone so small that typically only one eye of a viewer can occupy it at a time. A multiplexer HOE comprised of thousands of tiny holograms, each when reconstructed projects a spot onto the directional screen HOE. The sum of all these spots forms a two-dimensional raster of spots on the directional screen HOE. Each spot can be projected onto the directional screen HOE from at least two laterally different angles and thus reconstruct the directional screen HOE from at least two laterally offset angles, consequently creating at least two laterally offset viewing zones of each spot.

Abstract: Three-dimensional information for each object structure is used to provide a 2-dimensional plane to obtain a 2-dimensional image. Two-dimensional images by the projection seen from a plurality of points, which were finely divided on a hologram forming surface are formed on the 2-dimensional setting plane. As for an electronic hologram, a phase distribution at the hologram forming surface is calculated from the 2-dimensional images of each figure structure. The calculated phase distribution is displayed on a liquid crystal display or the like. A reference light is irradiated onto the phase distribution and is converted into an optical wave front, thereby displaying a solid image. In case of forming a hologram recording medium, each of the 2-dimensional images of a plurality of structures is multiplexingly exposed and the exposed regions are finely divided on a dry plate.

Abstract: A stereoscopic display method whereby a hologram phase distribution is calculated and the calculated phase distribution is expressed and the expressed phase distribution is converted into a wave front of the light, thereby displaying a solid image. Further, a feature portion in a display target specified by 3-dimensional information is detected. Sampling points are set at a high density into the detected feature portion. Sampling points are set at a low density with respect to a non-feature portion as a portion other than the feature portion. In the phase calculation, a hologram phase distribution is calculated with respect to the set sampling points.

Abstract: Computer-processed or computer-generated objects can be used to build holograms whose images are close to or straddle the hologram surface. No preliminary or first hologram is required. The hologram is built up from a number of contiguous, small, elemental pieces. Unorthodox views from inside the object are required for the creation of these elements. One method of generating the views employs unique object manipulations. The computational transformations ensure that no singularities arise and that more-or-less conventional modeling and rendering routines can be used. With a second method, a multiplicity of conventional object views are collected. Then, all pixels in these conventional viewplanes are reassigned to new and different locations in the new viewplanes for the elemental views. These methods may be used to build rainbow holograms or full parallax holograms. When properly executed they are visually indistinguishable from other types.

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 holographic stereogram which includes a plurality of element holograms and which reproduces a stereoscopic image by irradiation of coherent light, wherein each element hologram is loaded with a modulation value (pattern) corresponding to the stereoscopic image, the modulation value being a one-dimensional or two-dimensional transform coefficient obtained by one-dimensional or two-dimensional sine transform or discrete sine transform of the distribution of the intensity of diffraction light expressing the stereoscopic image, enabling simplification of the drive system of the display device displaying the stereoscopic image and reproduction of the original stereoscopic image much more faithfully.

Abstract: A three-dimensional image display device which comprises a light source; a hologram divided into a plurality of divided areas and exposed so that point images are formed at different positions in a three-dimensional space in the respective divided areas when the light from the light source is irradiated; a hologram driver unit for driving the hologram such that light from the light source is selectively entered into one of the plurality of divided areas and; a control unit for controlling the lighting up of the point images formed in the three-dimensional space in correspondence to a three-dimensional image signal by controlling the hologram and the light source in accordance with the three-dimensional image signal to be displayed, whereby a three-dimensional image is obtained by the hologram with the simple-configured device.