Abstract: A method for processing information stored in a holographic system, comprising the step of intersecting a reconstruction reference beam with a storage medium of a holographic system, the storage medium exhibiting birefringence at least partially due to coherent storage of information, wherein the reconstruction reference beam has a polarization at least 5.degree. different from the polarization exhibited by a storage reference beam during storage information in the storage medium.

Abstract: Systems and methods for steering a complex, spatially-modulated incident beam of coherent light to gain access to data locations in a holographic memory cell (HMC). One of the systems includes: (1) a reflective element, locatable proximate a first focal plane of the incident beam, (2) a rotational steering mechanism, coupled to the reflective element, that orients the reflective element according to a desired rotational angle to steer the incident beam in a desired direction and (3) a refractive element that refracts the beam reflected from the reflective element to create a second focal plane for the beam, the HMC locatable proximate the second focal plane and rotatable about an axis of a plane thereof to receive the beam at a location thereon that is a function of the desired direction and an angular position of the HMC.

Abstract: Systems and methods for steering an optical path to gain access to data locations in a holographic memory cell (HMC). One of the systems includes: (1) a reflective element, locatable proximate a first focal plane of a complex, spatially-modulated incident beam of light, (2) a polar steering mechanism, coupled to the reflective element, that orients the reflective element according to desired tilt and precession angles to steer the incident beam in a desired direction and (3) a refractive element that refracts the beam reflected from the reflective element to create a second focal plane for the beam, the HMC locatable proximate the second focal plane to receive the beam at a location thereon that is a function of the desired direction.

Abstract: A hologram display item comprising a hologram member having a front surface with a holographic image thereon and a rear surface. A light source assembly is also provided and is structurally connected to, and fixed relative to, the hologram, at a position to impinge light energy onto the holographic image. In this arrangement, the light source is fixed relative to the holographic image so as to provide, at all times, optimum viewing of the hologram by the observer independent of the position of the hologram display item relative to the position of the observer. The light source, fixed to the hologram display item, emits light energy substantially from a point within the light source at a predetermined angle advantageous for replay or viewing, the angle usually being similar to the known or discoverable angle of original hologram construction.

Abstract: Holograms and diffraction gratings are described wherein the presence of a "key-colour" (Magenta) permits an observer to identify the position where all the other colours of the hologram in question can be univocally determined. Two set of spectra are provided such that at a predetermined angle a reference beam of incident white-light illuminating the hologram or diffraction grating composition will cause the observer to see the color "Magenta" which is to be used as a reference "key-colour".

Abstract: The twin-image elimination apparatus of the present invention comprises (a) a scanning light source for emitting a scanning light beam; (b) an interference device which converts the scanning light beam from the scanning light source into a spherical wave and a plane wave having temporal frequencies different from each other and combines the spherical and plane waves together; (c) a scanner for scanning an object with the combined light beam from the interference device; (d) a photodetector for detecting a scattered wave from the object; (e) a first multiplier which converts an output signal of the photodetector into a cosine-coded holographic information; (f) a second multiplier which converts the output signal of the photodetector into a sine-coded holographic information; and (g) a holographic reconstruction device which converts output signals of the first and second multipliers into a sum signal, in which these output signals are added together with a phase difference of .pi./2+2n.pi.

Abstract: A plurality of holograms are simultaneously angularly and spatially multiplexed within a storage medium by writing the holograms at different locations within the storage medium using reference and object beams directed thereto via cooperating reference beam and object beam scanners, respectively. The simultaneously angular and spatially multiplexed holograms are subsequently read-out by directing a reference beam through a desired location within the storage medium using the reference beam scanner. The reference beam is directed from the storage medium to a phase conjugator which conjugates the phase of the reference beam and directs the phase conjugated reference beam back to the same desired location within the storage medium so as to excite a corresponding conjugate object beam which is then directed onto a detector array.

Abstract: An exposure apparatus for reproducing a mask pattern onto a photo-sensitive surface of a substrate uses holographic techniques. The apparatus includes support for holding a hologram recording plate at a predetermined position during both a recording operation and a reconstructing operation. A first illuminating optical system introduces a light beam from a coherent light source to a mask and irradiates a subject beam produced from the mask into the recording plate. A second illuminating optical system irradiates the light beam from a coherent light source as a reference beam into the recording plate, a carrier apparatus disposes during the reconstructing operation, a substrate at the position of the mask, in place of the mask. A third illuminating optical system for irradiates a conjugate beam with the reference beam into the recording plate, in which a hologram has been formed by the recording operation, to form an image of the hologram on the photo-sensitive surface of the substrate.

Abstract: A holographic apparatus for continually sensing, transmitting and reconstructing a three-dimensional image including a device for receiving a holographic interference pattern such as a video camera, a device for creating a holographic interference pattern on the receiving device, a device for focusing the interference pattern on the input of the receiving device, a device for transmitting the received holographic interference pattern including a device such as a computer, a device for converting the transmitted holographic interference pattern to a holographic interference pattern which is representative of the three-dimensional image such as an LCD and a source of coherent light illuminating the holographic interference pattern on the converting means to reconstruct the three-dimensional image.

Abstract: A method is provided for normalizing correlation data from a holographic correlator. After a sequence of object image patterns are recorded in an angularly multiplexed hologram, the entire volume hologram contents are read out with a uniform (plane wave) object beam. The plane wave readout produces an array of spots at a correlation plane, with the intensity of each spot representing the strength of the recorded hologram for the corresponding stored image pattern. The spot intensity values are accurately detected and stored as normalization factors. Holographic correlation output array values produced by parallel comparison of an input object pattern with the stored image patterns are then divided by the corresponding normalization factors. The resulting normalized correlation output accurately represents the true degree of correlation between the input object pattern and the stored image patterns by eliminating the uncertainty factor.

Abstract: A method and apparatus for producing an image of a target area, by: at an observation location spaced from the target area, transmitting a beam of electromagnetic radiation toward the target area, and receiving reflections of the radiation from the target area; providing a representation of the magnitude and direction of the distance between points on the target area which produce reflections that travel in phase to the observation location; varying the spatial relation between the observation location and the target area and/or the given radiation frequency, in order to establish a plurality of different observation states which succeed one another in time, each state being associated with a distinct combination of magnitude and direction of the distance between points on the target area which produce reflections that travel in phase to the observation location; producing two coherent radiation beams, directing the two beams onto a receiving plane provided with an array of radiation receiving cells and stori

Abstract: A multiple image multiplexed holographic display including a light pipe (11, 111) having first and second opposing surfaces (11a, 11b, 111a, 111b) and a plurality of input surfaces (15, 115) located between adjacent edges of the first and second opposing surfaces. A multiple image hologram structure (13, 113) attached to one of the first and second opposing surfaces is illuminated with respective beams injected into the light pipe by a plurality of light sources (17, 50, 61) adjacent respective input surfaces. The injected beams are incident on the hologram structure at different incidence angles, and the hologram structure contains holographic images that are recorded to reconstruct in response to respective injected beams, whereby each holographic image is selectively displayed by controlling its associated light source.

Abstract: Apparatus comprising a decal disposed on an interior surface of a window and a light source for projecting light onto the to display an image outside of the vehicle. The decal comprises a protective layer having a hologram layer disposed thereon that is designed to transmit a holographic image in a predetermined viewing direction. An opaque and clear mask layer into which an icon is incorporated may be secured to the hologram layer to provide a two-dimensional image. The hologram layer is illuminated by sunlight, skylight, or a light source and projects an image to a viewer at a predefined direction. During the day, the icon is viewable because light transmits through the clear portions of the mask layer is clear, and is blocked by opaque portions of the mask layer that define the icon. At night, the decal is illuminated by light from a light source 18, or an exterior or ambient light source to produce an image viewable by the observer.

Abstract: A method and system for recording and displaying grazing-incidence (i.e., steep reference beam angle) holograms supported on a substrate having thin edge-illuminatable geometry. The system and process of the present invention uses thin edge-illuminated substrates that facilitate optimal coupling of the reference light beam at steep angles approaching grazing incidence. Different recording techniques are employed when the index of refraction of the substrate is greater than that of the recording medium, than when the index of refraction of the substrate is less than that of the recording medium.

Abstract: A holographic data storage system includes a laser (12) for generating both data and reference beams. The reference beam is deflected by an optic system such that the reference beam can be directed at the surface of a thin holographic storage media (10) to interfere with a data beam to store data in the form of an interference grating. For each Bragg angle associated with a reference beam and a data beam, multiple pages of information are stored in the storage media (10). Each page of information stored at a given Bragg angle is associated with a different Bragg plane. Upon reconstruction of the data, a given reference beam at a given Bragg angle will reconstruct the data in the associated Bragg plane on a detector (42) and will reconstruct data for the same Bragg angle but a different Bragg plane in an off-image plane (88) or (90). This, therefore, allows multiple pages of information to be stored for the same Bragg angle in the same storage region (54).

Abstract: A holographic effect is generated on a holographic security device by diffraction of light by a surface relief pattern on a film. When illuminated, a moire pattern is generated from a pair of overlapping, regular arrays of lines or dots. Each array has a line of symmetry. The lines of symmetry are aligned. The device exhibits an ordered variation in the form of observed moire patterns in a direction parallel with the alignment direction of the lines of symmetry and a color variation but substantially no form variation transverse to alignment direction.

Abstract: A method and apparatus for fixing images, holograms and domain gratings in crystals by application of an electric field on a crystal and simultaneous illumination of it with a light pattern. The fixing procedure is based on a screening effect. The modulation of the domains may be perpendicular to the c-axis. Another application of the method is in frequency mixing such as second harmonic generation and parametric processes, by overcoming the problem of phase matching using the domain gratings. Thus, it is possible to obtain controllable broadband mixing and tailored quasi-phase matching for several wavelengths or for prespecified wavelength tuning ranges and frequency widths.

Abstract: A method and apparatus are provided for reducing speckle noise in images read out from holographic memories. An image recorded in the memory is read out using a multiple component readout beam, with each component having the same horizontal orientation but a different vertical orientation. Because the Bragg effect is pronounced only in the horizontal direction, the readout beam components all access the same stored image. Each readout beam component is set to oscillate at a slightly different frequency such that the smallest frequency difference is greater than the reciprocal of the output detector response time. The multiple oscillating readout beam components can be produced by an acoustooptic deflector driven by a wideband electrical signal. The memory readout comprises multiple reconstructions of the desired image, with each image reconstruction oscillating at a slightly different optical frequency.

Abstract: An apparatus for reconstructing holographic images includes a white light source, diffraction grating (1112) for generating zero-order diffracted light (1416) and at least first-order diffracted light, and light control film (LCF 1810) which is configured to block the zero-order diffracted light and to facilitate passage of a desired bandwidth of first-order diffracted light therethrough. In one embodiment light control film (LCF 1810) comprises a front layer (1802), a core layer (1804), and a back layer (1806). The back layer (1806) may be thought of as a datum, whereby a lateral shift in front film (1802) results in wavelength selectively, and a corresponding shift in core layer (1804) results in good zero-order light blocking. The resulting light is a pseudo-monochromatic source having sufficient coherence for use as a hologram reconstruction beam.

Abstract: An optoelectronic tomographic reconstruction system utilizes spacial light modulators in charge couple devices to perform projection iterative reconstruction techniques and simultaneous iterative reconstruction techniques. A back projection processor uses a linear array of analog spacial light modulators in a cylindrical lens, an image detection array, and an image rotator. The image rotator smears a projected image at the same angle as the projection was taken. The back projection processor thus smears the projection back to the image space. An optoelectronic forward projection processor uses an spacial light modulator array, an image rotator, and an image detecting array. A reconstructed image displayed by the spacial light modulator is smeared by the rotator to forward project the reconstructed image on the image detecting array at the same angle as when the measured projection was taken. The forward projection processor thus smears the reconstructed image back into the projection space.

Abstract: A hologram which contains the record of a parallel bar-shaped pattern, like a bar code pattern, and which can be read with a single light-receiving element of simple structure with fewer restrictions on the installation position of the light-receiving element and with a minimal lowering in the read accuracy even if the light-receiving element is disposed a little out-of-position. Also disclosed is a method of reading such a hologram. A hologram is recorded in a region that extends in a direction intersecting each bar of a reconstructed bar-shaped pattern and that is not shorter than the length of the reconstructed bar-shaped pattern at least in the above-described direction. Alternatively, the hologram is recorded in a stripe region elongated at the above-described direction.

Abstract: A method is disclosed to holographically mark an object in a way that the mark cannot be removed, reproduced, or transferred covertly. The mark can be read from a distance so that the part can be verified as the one and only original. The mark is applied to an undulating or rough surface of the object. The method requires that a reference wave be reflected from the surface and holographically recorded. This wave is then regenerated so that it travels in the opposite direction. This regenerated wave is itself reflected from the surface to form a collimated reference wave which, together with an object wave, is used to form the holographic mark. The recorded image cannot be observed without the presence of the surface itself.

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: A hologram for security markings is provided by a laser transmission hologram (1-4) formed as a surface relief pattern and a coating of a thin metallic layer (5) on the surface relief pattern whereby the hologram is capable of reflecting light from a laser (10). The metallic layer is, preferably, about 500 angstroms thick and the hologram may be mounted on a substrate (7) of an item required to bear the security marking defined by the hologram. In a feature of the invention an apparatus is provided for reading light reflected from the hologram comprising a laser (10) for projecting a beam (9) onto the hologram to be read and a detector (31) and associated logic devices for recognizing a real image of the hologram. The apparatus has the advantage that the laser (10) and detector (31) are both located on the same side of the hologram to be read.

Abstract: The present invention is directed to a diffractive display suitable for presenting graphic and the like displays. Broadly, the novel display is realized from a diffraction pattern (132) carried by (e.g. embossed) a film or element (138) connected to an energy source which is energizable for movement of the film (138). Movement of the patterned film (138) generates a display using the diffracted light from the embossed pattern (132). Electroactive films are known in the art, including, for example, piezoelectric films, electrostrictive films, electromotive films, and electrostatic films. Magnetoactive films also are known in the art. Any of these films (138) can carry the diffraction pattern (132) and be energized for movement to generate from the resulting diffracted light.

Abstract: Optical viewing system for producing a simulated three dimensional image. The system includes electronic equipment for displaying an image on a first electronic display device. Additional electronic equipment is provided for displaying an image on at least one second display device. The at least one second electronic display device is a substantially transparent display device, whereby an observer can view through transparent areas of the second electronic display device. The first and second electronic display devices are located at different, predetermined locations along an optical viewing path such that the image displayed by the first electronic display device is projected through the second electronic display device. The first electronic display device includes an image projector and the second electronic display device includes a controllable pixel display spaced therefrom.

Abstract: Materials of the formula I: ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 in each case independently of one another can be identical or different and are a hydrogen atom, halogen atom, hydroxyl group, nitro group, cyano group or monovalent, optionally substituted organic radical; R.sub.4 is a hydrogen atom, halogen atom, nitro group, cyano group or monovalent, optionally substituted organic radical; and R.sub.5 can be identical or different and is a halogen atom, hydroxyl group, nitro group, cyano group or monovalent, optionally substituted organic radical.

Abstract: The present invention is a holographic structured light generator (HSLG) for generating an array of an arbitrary number of laser beamlets from a single laser beam using a point laser light source and a hologram. In a first preferred embodiment of the present invention, a hologram having an image of four point sources in a common plane is fabricated using four point sources as the object beam, and a reference beam. A reconstruction beam, aligned identically with respect to the hologram as was the reference beam during fabrication of the hologram, is then directed at the hologram, generating the array of laser beamlets from the four point sources in the hologram. In a primary application of the HSLG, it is used to map the surface of an object in three dimensions. The HSLG is used with video cameras, computer image processing equipment and an optical spatial light modulator to yield 3-D data for use with CAD systems.

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 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: A detected image output by a holographic storage system is comprised of a grid of dark and light spots, representing high and low logic states. The image is superimposed onto a grid of detector elements or pixels in a detector. Each of the data bits is represented by a bit image or bixel, which is oversampled by a factor of two along the x- and y-axis by the pixels. A state machine is utilized to generate expected states for each of the pixels and then an energy shifting operation performed to shift energy from a pixel having a higher than expected output value to a pixel having a lower than expected output value. This operation can result in energy being shifted from the left to the right or the right to the left. Column synchronization is performed by defining a set of pixels in a row for each column as a segment with an associated parity bit and row number. Each segment may be output as validated, or may be retained in a buffer until all previous segments in a row have been accumulated and/or output.

Abstract: A three-dimensional image display device which comprises a holographic plate having a plurality of holograms divided in correspondence with rotational angles, the holographic plate being exposed so that when light is irradiated, each of the holograms forms a point image at a different position in a depth direction of the holographic plate; a drive unit for rotating the holographic plate; a light irradiating unit including a plurality of light sources arranged substantially in a straight line so that the light sources are kept at substantially equal distances from the holographic plate, for irradiating the holographic plate with light from the light sources; and a controller for controlling the drive unit and lighting operations of the plurality of light sources of the light irradiating unit in accordance with a signal indicative of a three-dimensional image to be displayed so as to control lighting of a plurality of point images formed in a three-dimensional space, whereby a three-dimensional image can be obt

Abstract: A method of reconstructing a hologram (1) recorded so that an image of a plurality of parallel bar-shaped patterns (3) is reconstructed. An image of the bar-shaped patterns (3) is reconstructed by using reconstructing light (2) having an incident region (A) in which a diameter in a direction parallel to the bar-shaped patterns (3), which are to be reconstructed by the hologram (1), is larger than a diameter in a direction intersecting perpendicularly to them. Even if a read sensor (4) is disposed in an out-of-focus position, the hologram (1) can be reconstructed with relatively high resolving power. Thus, the method minimizes restrictions on the position of the read sensor (4) and lowering of the read accuracy.

Abstract: A monochromatic-light reproduction type hologram having a hologram recorded area provided with interference fringes that form a hologram image, the hologram image being reproducible by irradiating the hologram recorded area with monochromatic light at a given angle. A plurality of hologram images different from each other in the directionality of interference fringes are multiple-recorded in the hologram recorded area. Alternatively, the hologram recorded area is divided into a plurality of regions so that a plurality of hologram images different from each other in the directionality of interference fringes are separately recorded in the divided regions. The recorded area is successively or simultaneously irradiated with monochromatic light rays at given angles corresponding to the directionality of interference fringes of the respective hologram images, to reproduce the hologram images as a plurality of information patterns or a single information pattern.

Abstract: A hologram structure including a plurality of holograms having substantially identical reconstruction characteristics disposed on a substrate for rotation about a rotation axis and containing segments of a composite image. The holograms are angularly offset relative to each other about a rotation axis such that the composite image is visible over at least one narrow solid angular region pursuant to rotation of the holograms about the rotation axis and illumination of the holograms with a reconstruction beam.

Abstract: A display hologram structure including a display hologram configured for reconstruction with a playback beam having a predetermined wavefront configuration, and a light configuring hologram that provides playback illumination for the display hologram pursuant to diffraction of an off-axis playback beam that does not have the predetermined wavefront configuration, and wherein the playback illumination provided by the light configuring hologram has the predetermined wavefront configuration.

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.

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 Fourier transform hologram image is created on a sheet on the seal. The image is made, by making a die from the Fourier transform hologram image master plate and by molding resin on the die. The image formed on the sheet is reconstructed by an identification apparatus. The identification apparatus contains the laser emitting device and the screen for receiving the reflecting laser beam. The laser beam is illuminated vertically against the sheet from the laser emitting device. The laser beam reflected from the sheet surface is received by the screen, and the image of the sheet is reconstructed on the screen. At this time, it is possible to check whether the laser beam is reaching the sheet from an opening in the casing.

Abstract: A method and apparatus for producing an image of a target area, by: at an observation location spaced from the target area, transmitting a beam of electromagnetic radiation toward the target area, and receiving reflections of the radiation from the target area; providing a representation of the magnitude and direction of the distance between points on the target area which produce reflections that travel in phase to the observation location; varying the spatial relation between the observation location and the target area and/or the given radiation frequency, in order to establish a plurality of different observation states which succeed one another in time, each state being associated with a distinct combination of magnitude and direction of the distance between points on the target area which produce reflections that travel in phase to the observation location; producing two coherent radiation beams, directing the two beams onto a receiving plane provided with an array of radiation receiving cells and stori

Abstract: A holographic apparatus for continually sensing, transmitting and reconstructing a three-dimensional image including a device for receiving a holographic interference pattern such as a video camera, a device for creating a holographic interference pattern on the receiving device, a device for focusing the interference pattern on the input of the receiving device, a device for transmitting the received holographic interference pattern including a device such as a computer, a device for converting the transmitted holographic interference pattern to a holographic interference pattern which is representative of the three-dimensional image such as an LCD and a source of coherent light illuminating the holographic interference pattern on the converting means to reconstruct the three-dimensional image.

Abstract: A laser light show device and method produces a surface projected or suspended holographic image, and includes multiple image projectors. One image projector provides the object image information representing the primary subject. For surface projections, additional background image projectors provide background image information generated using a wobbler plate-reflected beam diffracted through a spherical lens, a beam unidimensionally diffracted through a rotating cylindrical amorphic dipolyhedral lens, and a beam diffracted through multiple diffraction gratings. A suspended holographic image is produced by parabolically focusing multiple images projected onto a spherical image screen.

Abstract: A light box includes a lower casing and an upper casing pivotally connected to the lower casing. A lighting element is pivotally mounted to the inner side of the lower casing. A plurality of pairs of spaced ridges are provided on both longitudinal sides of the inner periphery of the lower casing. A plate is pivotally received in the inner side of the upper casing at an upper side thereof. The lower side of the plate is selectively supported by one of the pairs of the ridges. A hologram is provided on one side of the plate which faces the lighting element. When the upper casing is opened to a pre-determined extent, the lighting element is switched on. Under adjustment of the inclination of the hologram plate and the lighting element, a viewer may appreciate various images contained in the hologram.

Abstract: An optical device for receiving incident light having a minimum wavelength, and for producing a resultant light containing an optical image. The device includes a first material having a first index of refraction and a surface embossed with an optical interference pattern, and a second material having a second index of refraction deposited onto the embossed surface of the first material. The depth of deposition is at least equal to three quarters of the minimum wavelength component of the incident light within the second material.

Abstract: A holographic display and method for displaying hologram are disclosed. The method and apparatus provides a compact display arrangement in which the light source for illuminating the display is integral with the display, or in other words, an external light source is not necessary. The hologram utilized in the display is formed as a rainbow hologram, with a converging reference beam utilized in forming the diffraction grating upon the holographic plate. The display includes a pair of spaced transparent glass sheets, with the light source disposed between the glass sheets. The holographic plate formed with the converging reference beam is then mounted upon one of the glass sheets, with the light source illuminating the holographic plate with diverging illumination light. A mirror is associated with each of the transparent glass sheets at a location adjacent to the light source, with the reflective surfaces of the mirrors facing each other.

Abstract: The present invention provides a method and apparatus for producing a hologram from a series of two-dimensional images horizontally different in line of sight from each other. The holographic apparatus employs original images produced by photographing an object from different directions, an object optical system which makes a light be incident upon original image to project an object beam onto photo-sensitive material, and a reference optical system which projects a reference beam of a same wavelength as the object beam toward the photo-sensitive material. The horizontal component of the object beam can be converged at a rear point i.e., a point of view at image reproduction, relatively distant from the photo-sensitive material on which a hologram is produced. When the hologram is reconstructed, a beam having the same wavelength as when recorded is converged at the rear point of view, so that the reconstructed image can be viewed in a same color free from any color shading.

Abstract: Methods for generating holograms from a computer model of any object employ a combination of numerical and optical means. An illumination model and the light dispersion properties of the object are specified. The hologram is synthesized from a plurality of smaller hologram elements. Each individual element sustains a field of view of the object. The light rays from the object lying within the field of view and along the lines of sight are sampled by the computer. The sample density should not exceed the resolution limit set by the size of the hologram element. Each light ray is specified by a direction and an amplitude function. The hologram element is obtainable from a Fourier Transform fo the sampled rays. In one embodiment, optical means are employed to physically reproduce the sampled light rays using coherent radiation. The reproduced coherent light rays are then interfered with a coherent reference beam to form the hologram element.

Abstract: Holograms are formed in moldable materials of varied shapes and curvatures utilizing injection molding and the like. Instead of the conventional metallizing, there can be sprayed on flakes of highly specular metal made by breaking up a thin coating of metal metallized by conventional metallizing on a removable support. Hologram on one surface of a molding that has a 100% mirror on an opposing surface, is suitable for cosmetic compact case covers or the like. Holograms can also be applied to digital compact audio discs or video discs.

Abstract: A holographic apparatus for continually sensing, transmitting and reconstructing a three-dimensional image including a device for receiving a holographic interference pattern, a device for creating a holographic interference pattern on the receiving device, a device for transmitting the received holographic interference pattern, a device for converting the transmitted holographic interference pattern to a holographic interference pattern which is representative of the three-dimensional image and a source of coherent light illuminating the holographic interference pattern on the converting means to reconstruct the three-dimensional image.

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.