Abstract: Device, method, and system for recording diffractive high resolution text, pictorial, and/or other graphical information is provided which is particularly suited to recording information that would be difficult to reproduce by typical counterfeiting methods. The information recorded may be used to authenticate the recorded item, or indirectly, an item to which the recording is attached. Such items may include legal, financial and commercial instruments, credit cards, and packaging for such items as software, art, and other items where forgery of the item may be a concern. In one embodiment of the invention light is selectively passed by a shutter, and a spatial filter then cleans the beam to remove undesirable frequency components.

Abstract: A holographic image produced by the impression of a shim onto a metallic ink coating comprising a plurality of metallic particles suspended in a resinous ink binder. A resinous or substantially tactile and nonresilient undercoat can be applied to the substrate also to receive the impression of the shim and to create more distinct holographic imagery. A substantially clear overcoat can also be applied over the metallic ink coating to enhance the reflectivity of the image.

Abstract: The reconstruction region of a hologram reconstructed image is segmented. A fast Fourier transform (FFT) is carried out after multiplying the hologram measurement data V(R) by a weighting function. A fast Fourier transform (FFT) is carried out after multiplying the antenna sensitivity inverse matrix A.sup.-1 (R'.sub.a,b) for each segment by inverse propagation function r'.sub.a,b exp(j2.pi.r'.sub.a,b /.lambda.) to find B.sup.-1.sub.a,b (s, t), and then multiplying this by a weighting function. After the two FFT outputs are multiplied by each other, inverse fast Fourier transform (IFFT) is carried out. Compensation is performed for the weighting function and the output is made the segment reconstructed image. In addition, radio hologram observation is carried out at two scan surfaces, a horizontal polarization antenna and a vertical polarization antenna are placed at each scan surface, and the voltage vector distribution received by the antennas is stored.

Abstract: Holographic test structures on a semiconductor wafer are used to provide real-time analysis of upstream fabrication processing parameters. The test structures comprise reflective segments within multiple cells on the test structure. The size and placement of the reflective segments within the cells are determined by diffraction theory in such a way that a desired image is projected from the test structure. The intensity, sharpness, and shape of the image is used as a direct measure of the upstream fabrication process parameters.

Abstract: A polarisation independent optical switch is constituted by a light input (6), a diffractive and re-configurable liquid crystal device (8), a collimating lens (7) for distributing the input light over the liquid crystal device (8), a transform lens (9) receiving light from the liquid crystal device (8) and light output (6), wherein no polarisers are present between the light input and output. The diffractive and re-configurable liquid crystal device (8) may be formed as a liquid crystal spatial light modulator configured as a binary phase computer generated hologram with the holograms required to form broadcast, individual or multicast switching being re-generated using an iterative algorithm and then being recalled on demand. In one embodiment the switch has a folded configuration and includes a reflector (10) so that the light input and output are both on the same side of the liquid crystal device (8).

Abstract: A compound semiconductor that is suitably doped to exhibit the DX effect is irradiated with an optical beam of spatially varying intensity whereby localized regions of persistently higher conductivity and lower refractive index are created in the semiconductor where sufficient intensity of the beam was incident. The persistently higher conductive region can be used to bridge selected gaps in conductive paths on a support member use in memory device and the regions of lower refractive index can be used to providing guiding in a wave guide, to form high resolution gratings, or to form holograms.

Abstract: A pixellated diffractive device includes a multiplicity of pixels in turn divided into multiple sub-pixels. The device is related to one or more pixellated diffraction surface structures which when illuminated generate respective corresponding optically variable images. The sub-pixels of each pixel of the diffractive device include diffractive elements arranged in one or more groups, the diffractive elements of each group matching diffractive elements of a corresponding single pixel of the respective pixellated diffraction surface structures. In each pixel of the device the diffractive elements of the or each said group are intermixed with other subpixels and cooperatively contribute a single element of the corresponding optically variable image which is generated on illumination of the diffractive device.

Abstract: An output light from an light source lamp unit 8 in a projection-type display apparatus illuminates liquid-crystal light valves 925R, 925G and 925B for three colors via an integrator optical system 923. A superimposing lens 930 that is a component of the integrator optical system 923 as a uniform illumination optical system is arranged such that the mounting position of the superimposing lens 930 is fine-adjustable in a direction orthogonal to an optical axis 1a. By fine-adjusting the mounting position of the superimposing lens 930, the position of an illumination area B is adjusted such that the illumination area includes the image forming area A of the liquid-crystal light valve. It is not necessary to assure a wide margin around the image forming area A to cover the offset of the position of the illumination area B. As a result, the utilization of illumination light is heightened and a bright projected image results.

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 beam homogenizer that minimizes undesired intensity variations at the output plane caused by sharp breaks between facets in previous embodiments. The homogenizer includes a hologram made up of irregularly patterned diffractive fringes. An input beam illuminates at least part of the hologram. The hologram transmits a portion of the input beam onto an output plane. In doing so, the energy of the input beam is spatially redistributed at the output plane into a homogenized output beam having a preselected spatial energy distribution at the output plane. Thus, the illuminated portion of the output plane has a shape predetermined by the designer of the homogenizer.

Abstract: A means, method and apparatus for producing a parallel addressable set of images by modulating a set of input beams with addressing information, and projecting the energy from a three-dimensional array of first pixel locations which decode in parallel to produce an interference image at the location of a second three-dimensional array of pixel locations, energizing at least one of the second pixels. Each image corresponds with an input address. A subset of addresses, projection surface configurations, and images exhibit useful synergistic relationships. These are used to address a ROM, RAM, or content addressable memory, provide a visual display of selected images, iterate in a series to produce four dimensional computing, integrate information from multiple energy forms, and accomplish signal processing and channel switching.

Abstract: An object of the present invention is to provide a simple image projection apparatus which prevents color shading. First, second and third dichroic mirrors are provided in parallel which separate light from a source into red, blue, and green components. First and second polarization beam splitters are provided with operative surfaces perpendicular to the dichroic mirrors for reflecting predetermined polarization light components of two colors to two reflection type liquid crystal devices. A third polarization beam splitter having an operative surface in parallel to the dichroic mirrors is provided for reflecting a predetermined polarized light component of the third color component to a third reflection type liquid crystal device. A cross dichroic prism device is provided for combining the modulated light from the three liquid crystal devices and transmitting the synthesized light for projection.

Abstract: A projecting type image display apparatus includes a calculation processing unit for calculating a Fraunhofer diffraction image of an original image, an image display unit for producing/displaying the calculated Fraunhofer diffraction image, and an image converting unit for projecting the produced/displayed Fraunhofer diffraction image to the original image and projecting the original image on the screen. The calculation processing unit has a function of calculating the Fraunhofer diffraction image of the projection image and outputting the same to the image display unit. The image display unit is provided with an image display element on which the Fraunhofer diffraction image is optically displayed. The image projecting unit is provided with first and second lenses for converting the Fraunhofer diffraction image to the original image and projecting the original image on the screen.

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: A mask for generating a high density regular matrix of working images for generating a corresponding high density regular matrix of vias in a substrate, the computer generated holographic images from overlapped subapertures are processed for maximum fluence. For each working image, a diverging wave front of the first order is propagated using Fresnel diffraction to produce for that wave front the corresponding first order holographic image at a central unit cell. The first order holographic image for each of the working images to be produced by the unit cell is added until the configuration of a unit mask cell containing portions of all working images to be broadcast is attained. The projection from the unit cell to working image is arbitrarily altered to attain the smallest local maximum first order transmission requirement within the central unit cell; the large local maximum first order transmission requirements are essentially moved outside the bounds of the central unit cell.

Abstract: An achromatic optical system that preferably includes a light source for emitting light therefrom, an achromatic optical element positioned to receive light emitted from the light source, and an optical detector positioned to receive and detect light passing through the optical element. The achromatic optical element preferably includes a substrate having opposing sides, a first computer generated hologram positioned on one side of the substrate and adapted to receive light emitted from the light source, and a second computer generated hologram positionally aligned on the opposite side of the substrate and adapted to receive light passing through the substrate from the first hologram at a predetermined location thereon.

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: 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: 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 tight packed array of amplitude controlled in-phase light emitters produces dynamic real holographic images. A partially reflecting mirror is applied to a planar array of amplitude controlled laser diode emitters which are stimulated by each other. The emitters are forced into phase with each other by partially reflecting light energy from adjacent row and column elements onto each other. Incident energy stimulates the element receiving the energy to fire in phase with the incident energy. The array may be forced in phase by directly illumination from a master laser. A single laser is used to illuminate a flat surface containing an array of transmissive apertures which act as emitters. Amplitudes are controlled by liquid crystals. Light from the emitters forms an image which changes according to amplitudes of the individual emitters. Optical focal plane reducers reduce the effective inter element spacing.

Abstract: A method for manufacturing optical components having a periodic or quasi-periodic structure such as diffraction gratings, volume holograms or distributed feedback mirrors in optical fibers. An optical medium is subjected to acoustic waves which induce periodic or quasi-periodic changes in the optical properties of the medium, the changes being at least partially retained on removal of the waves. The changes may result from stress associated with the antinodes of an acoustic standing wave, alteratively the stress distribution associated with a travelling acoustic wave in an electro-viscous liquid may be semi-permanently retained by the solidification of the material resulting from the application of an electric field.

Abstract: A computer-assisted holographic-display apparatus comprises a diffraction image generator which receives an input image signal representing an object and computes corresponding diffraction pattern with a first sampling density. An interpolation processor is connected to the diffraction image generator via an intermediate page memory. The interpolation processor subjects the diffraction pattern to the interpolation process to create an interpolated diffraction pattern with an increased second sampling density. An interference pattern generator is connected to the interpolation processor to compute an interference caused pattern between the interpolated diffraction pattern and a reference wave by converting amplitude and phase distributions of the input image signal into the intensity distribution. The interference pattern is displayed on a previously selected displaying device.

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: Optical machining of a workpiece with coherent light scanning a plate with a plurality of subaperture subapertures is disclosed. Each of the subapertures creates a working image which when scanned with a coherent wave front of the design frequency forms in three dimensional space the working image. The working image when registered to a workpiece effect processing of the workpiece, usually ablating an aperture such as a blind via of small dimension. Improved techniques of dimensioning and fabricating the subaperture, creating amplitude modulation with the phase plate, and finally controlling amplitude with optical features close to the limit of producible optical elements is disclosed. The apparatus for the process, the process and the plate for utilization in the process are set forth.

Abstract: A holographic display apparatus has a display section including a back plate, on which a cold cathode device of the field emission type having a great number of fine emitter electrodes is arranged. The display section includes a transparent and conductive front plate, on which a great number of anode electrodes, which define pixels, are arranged respectively opposite the emitter electrodes. The emitter electrodes are selected so as to emit electrons by an input signal prepared in accordance with the interference pattern of a holographic diffraction figure. The anode electrodes are excited and induced by electron rays from the emitter electrodes to change their reflection coefficient. The interference pattern is displayed on the basis of the change in the reflection coefficient of the anode electrodes.

Abstract: In a system of proximity printing utilizing coherent light, a technique of phase only image correction is disclosed. Specifically, a holographic corrector plate is utilized. The image on the holographic corrector plate is produced by constructing a holographic image from the broadcast image and the intended working image. The broadcast image and the intended working image are placed in precise proximity printing alignment. With the respective images aligned, a coherent light beam is split to provide two temporally and spatially coherent beams. One of the temporally and spatially coherent beams scans the broadcast image. The other temporally and spatially coherent beam scans a mask containing the intended working image in a corresponding scan. A plane of beam intersection is chosen, with precise correspondence between rays at any point on the broadcast mask to rays from corresponding points on the working image mask.

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: Light diffraction device using reconfigurable spatial light modulators and the fractional Talbot effect. This device comprises two liquid crystal, electrically addressable spatial light modulators (M1, M2) on a semiconductor substrate and at least one polarizing beam splitter (2), the optical path between the modulators being equal to (2k+1) Z.sub.T /4.sup.n in which k and n are natural integers, n differing from zero, and Z.sub.T is the Talbot distance relative to a biperiodic hologram obtained by means of one of the modulators and at one of the periods equal to double the other, which makes it possible to obtain a reconfigurable hologram having four phase levels. Application to optical telecommunications.

Abstract: A beam homogenizer for converting an incident beam of non-uniform spatial power or energy distribution into an output beam of uniform spatial power or energy distribution. The homogenizer is a holographic optical element constructed from an array of facets or subholograms and positioned at a first plane in the path of an incident signal. The transmittance from each subhologram is uniformly spread across a target at a second plane that is spaced away from the first plane Another optical element, such as a holographic collimation element, may be placed at the second plane to collimate the transmittances thereupon.

Abstract: An aromatic optical system that preferably includes a light source for emitting light therefrom, an achromatic optical element positioned to receive light emitted from the light source, and an optical detector positioned to receive and detect light passing through the optical element. The achromatic optical element preferably includes a substrate having opposing sides, a first computer generated hologram positioned on one side of the substrate and adapted to receive light emitted from the light source, and a second computer generated hologram positionally aligned on the opposite side of the substrate and adapted to receive light passing through the substrate from the first hologram at a predetermined location thereon.

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: The invention provides an optical device with high light utilization efficiency that is capable of scribing patterns on curved surfaces, as well as flat surfaces, using a liquid crystal spatial light modulator. The invention offers an optical device with high light utilization efficiency and that is capable of three-dimensional formation of curved surfaces using a liquid crystal spatial light modulator. Additionally, the invention offers a widely applicable optical processing system that mounts these optical devices on robots. The invention includes at least a coherent light source, a liquid crystal spatial light modulator for controlling the wavefront of the light from the coherent light source, and a means that records the complex amplitude distribution on the liquid crystal spatial light modulator.

Abstract: This is a processing module which may be used for parallel processing. Multiple software configurable optical interconnections provide for high speed processing which preferably use computer generated holograms to communicate among multiple processing elements. Other methods and devices are disclosed.

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: 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: A method and a viewing device for generation of selective visual effects. The method entails encoding a holographic optical transparency for generating pre-selected patterns of light when stimulated by appropriate sources of light and a structure to enable viewing through such a transparency. The viewing device contains a suitably encoded holographic optical transparency and a structure produced with semi-rigid material which allow viewing of the natural scene through the transparency with two eyes. The encoding of the transparencies causes all limited extent light sources in a scene to be replaced with pre-selected patterns of light while producing minimal distortion in the remainder of the scene.

Abstract: A system for optically providing one-to-many irregular interconnections, and strength-adjustable many-to-many irregular interconnections which may be provided with strengths (weights) w.sub.ij using multiple laser beams which address multiple holograms and means for combining the beams modified by the holograms to form multiple interconnections, such as a cross-bar switching network. The optical means for interconnection is based on entering a series of complex computer-generated holograms on an electrically addressed spatial light modulator for real-time reconfigurations, thus providing flexibility for interconnection networks for large-scale practical use. By employing multiple sources and holograms, the number of interconnection patterns achieved is increased greatly.

Abstract: A real-time holography system includes a matrix liquid crystal display, as used in a liquid-crystal television set, for producing a hologram. An image of an interference-fringe pattern caused by an object light wave and a reference light wave is converted into a video signal by a CCD camera, and the image of the pattern is reproduced on the display on the basis of the video signal. Therefore, a three-dimensional image can be reconstructed in real-time by making a reference light wave on the display.

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: An optical apparatus for controlling a wave front of a coherent light including at least a coherent light source, an electrically addressable liquid crystal device having a plurality of pixels receiving the light from said light source, and a signal generator for recording a complex amplitude distribution or hologram on the liquid crystal device.

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: The method involves directing first and second separate illuminating beams towards a photosensitive film from separate fixed apparent beam source positions respectively in such a manner that the beams are caused to overlap at the point of incidence at the photosensitive film. Stationary interference fringes are generated and the beams are caused to scan in a raster type pattern over the photosensitive film in such a manner whereby overlapping of the beams is maintained throughout the exposure of the film. The apparatus in one embodiment involves the generation of a third illuminating beam which is used to control means to control an associated scanner to effect synchronised movement of the second beam with the first beam. A further embodiment involves memorising the scanning movement of beam in a memory and using the memorised scanning pattern to control the scanner to maintain beam overlap.

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: 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 method of and apparatus for efficiently correcting an aberration of an optical system used to record a hologram at the stage of reconstructing an image of the hologram. At the stage of reconstructing an image of a hologram (3), which contains the record of interference fringes formed by a reference plane wave and an object wave modulated by a sample, by applying a plane wave for reconstruction to the hologram (3) from a laser (1), an aberration of an optical system used to record the hologram (3) is canceled by the phase distribution on a liquid crystal panel (6) having a spatial phase modulation function, which is disposed on the Fourier transform plane, thereby correcting the aberration. The phase distribution on the liquid crystal panel (6) can be changed flexibly by a computer (9) in accordance with the aberration coefficients or degree of defocusing of the recording optical system.

Abstract: A dynamic holographic display has an array of reflective surfaces formed on cantilever structures substantially parallel to the surface of a substrate, such as a silicon wafer. A holographic image is formed by controlling electrical currents passed through the cantilever structures to position the reflective surfaces of the cells in the array so the topography forms a hologram, and reflected light interferes to form a holographic image. In a preferred embodiment, control is by computer and positions of reflective surfaces are determined by calculation from dimensional data available to the control computer.

Abstract: A hologram surface to express a phase distribution, a visual field in which a solid image can be seen; and a stereoscopic display limit are set in a virtual space. A target to be stereoscopically displayed is subsequently expressed in the virtual space by a set of micro polygons. A plurality of slice planes which are parallel with the horizontal plane are set into the virtual space including the target. The line segments which intersect the polygons are obtained for every slice plane. The detected line segment is divided or clipped as necessary and is finally divided into the portion which can be always seen from the whole region of the visual field and a portion which is obstructed by another line segment and can be seen from only a part of the visual field, thereby extracting the line segment.