Abstract: An optical polarization apparatus for application to color displays for laptop computers and hand held computers, and other applications where it is advantageous to switchably control the polarization of monochromatic light. In a first preferred embodiment, the apparatus includes a first holographic optical device disposed between a source of randomly polarized light and a second holographic optical device that produces an output beam of plane-polarized light in a desired direction. The first optical device is a Bragg hologram that characteristically diffracts p-polarized light significantly more efficiently than s-polarized light. The first device splits the randomly polarized light into these two orthogonal components.

Abstract: The invention provides an optical lens having a combination volume holographic optical element that provides a diffractive optical power. The optical lens has a programmed activating angle in which the holographic optical element provides a diffractive optical power. The invention also provides a method for producing a multilayer holographic element suitable for the optical lens.

Abstract: A system and method for generating a composite display that includes at least one static three dimensional holographic image, and dynamic and/or static two dimensional images. An object hologram includes a three-dimensional object image. A silhouette hologram includes a silhouette image of the object, and can include a diffusion screen. The object hologram overlays the silhouette hologram with the object image substantially aligned with the silhouette image. Static and/or dynamic images can be projected on the diffusion screen or alternative background, forming a composite image that includes dynamic and/or static two-dimensional imagery combined with the static three-dimensional object image. The silhouette image thus provides a background for viewing the object image and occludes the two-dimensional imagery from the view of the object image.

Abstract: Disclosed is an apparatus and method of illuminating an image display via an electrically switchable holographic optical element. The method includes a first electrically switchable holographic optical element (ESHOE) receiving illumination light. The first ESHOE comprises oppositely facing front and back surfaces. The first ESHOE diffracts a first component (e.g., p-polarized blue light) of the illumination light while transmitting the remaining components of the illumination light without substantial alteration. An image display is provided and receives the diffracted first component. In response to receiving the diffracted first component, the image display emits image light. The first ESHOE receives and transmits this image light without substantial alteration.

Abstract: Disclosed are a holographic optical element (HOE) and a method of producing the HOE. In one embodiment of the method, a substrate is provided which is capable of recording a hologram or diffraction gratings. This substrate is illuminated with a first pair of light beams and a second pair of light beams. The first pair of light beams intersect within the substrate. The second pair of light beams also intersect within the substrate. Additionally, the first pair of light beams intersect at a region within the substrate where the second pair of light beams intersect. Normally, each of the first pair of light beams comprises light of a first wavelength, and each of the second pair of light beams comprises light of a second wavelength, where the first wavelength is different from the second wavelength.

Abstract: A switchable holographic device generally comprises a substrate having two generally opposed surfaces and a plurality of holographic fringes recorded in the substrate. The holographic fringes are configured to switch between active and passive states upon application of an electrical field. One or more of the plurality of holographic fringes are positioned such that a surface of the fringe is angled relative to one of the substrate surfaces. The holographic device further comprises a pair of electrodes each positioned generally adjacent to one of the substrate surfaces and operable to apply an electrical field to the fringes to switch the fringes between their active and passive states. One of the pair of electrodes has a plurality of independently controlled segments. Each of the segments is positioned over an area of the substrate having holographic fringes positioned within a common range of angles relative to the substrate surface.

Abstract: A positive unit magnification reflective head is used to back-reflect a primary light beam, for storing reflection microholograms at the coincident foci of the primary and reflected beams. Imaging the primary beam focus onto itself at positive unit magnification allows increasing system tolerance to tilts and transverse misalignments between the primary and reflective heads. Holograms are stored at multiple depths in a holographic storage medium. Tunable-focus primary and reflective heads are positioned on opposite sides of the storage medium. The reflective head images each storage location onto itself at positive unit magnification. Suitable reflective heads include: two lenses in an f-2f-f configuration and a planar mirror; a lens and a corner cube; a thin lens and a thick lens with a coated reflective back surface; and a thin lens and a back-coated gradient-index (GRIN) lens.

Abstract: Disclosed is an apparatus and method of illuminating an image display via an electrically switchable holographic optical element. The method includes a first electrically switchable holographic optical element (ESHOE) receiving illumination light. The first ESHOE comprises oppositely facing front and back surfaces. The first ESHOE diffracts a first component (e.g., p-polarized blue light) of the illumination light while transmitting the remaining components of the illumination light without substantial alteration. An image display is provided and receives the diffracted first component. In response to receiving the diffracted first component, the image display emits image light. The first ESHOE receives and transmits this image light without substantial alteration.

Abstract: Switchable holographic optical elements (HOEs) can used in systems and methods for projecting three-dimensional images, or for projecting two-dimensional tiled images with increased size and/or resolution. One of the methods may include sequentially displaying first, second, and third color components of a first two-dimensional image at an object plane. The first two dimensional image represents a first slice of a three-dimensional image. As the first, second, and third color components are displayed, first, second and third HOEs may be activated so that the activated first switchable HOE focuses the first color component of the first two-dimensional image onto a first image plane, the activated second switchable HOE focuses the second color component of the first two-dimensional image onto the first image plane, and the wherein the activated third switchable HOE focuses the third color component of the first two-dimensional image onto the first image plane.

Abstract: A full-color hologram capable of generating a bright image and reproducing colors in all color regions is formed by multiple recording or multilayer recording with four different dominant wavelengths for reconstruction. The full-color hologram has one reconstruction wavelength in the vicinity of the peak wavelength 555 nm of the spectral luminous efficiency curve, i.e. in the range of 550 nm to 560 nm, and further has three other reconstruction wavelengths in the three primary color regions of red, blue and green, i.e. in the three regions of 615 nm to 680 nm, 380 nm to 470 nm, and 485 nm to 515 nm, respectively.

Abstract: An image recording method and apparatus for recording an image on a holographic stereogram in such a manner as to generate an optimum reproduced image, and an image reproducing method and apparatus capable of generating an optimum reproduced image from the holographic stereogram. A parallax image string is recorded as a series of strip- or dot-shaped hologram elements by having an object light beam and a reference light beam fall on one and the other surfaces of a recording medium for hologram 130. On the reference light incident side, a light inlet block 52 is arranged for having contact with the recording medium for hologram 130 so that no significant change in the refractive index will be produced on an interface with the recording medium for hologram 130. The reference light beam is illuminated via this light inlet block 52 on the recording medium for hologram.

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 holographic resonant system includes a plurality of volume phase holograms superimposed on a single layer of photosensitive film. The volume phase holograms are oriented with respect to one another such that a first volume phase hologram selects an incoming light beam incident upon a surface of the holographic resonant system having a wavelength &lgr;playback and an angle of incidence &thgr;in and internally diffracts the incoming light beam to a second volume phase hologram. The second volume phase hologram then accepts the resulting diffracted light beam from the first volume phase hologram and diffracts the light beam to form an image reflected from the surface of the holographic resonant system at wavelength &lgr;playback and an angle &thgr;out. The result is a holographic resonant system that only permits light beams from a predetermined direction to illuminate the system, thereby reducing the effect of ambient light upon the system and thus increasing the contrast ratio of the image.

Abstract: Holographic optical elements (HOEs) can be used in systems and methods for providing illumination and for projecting images. The HOEs may be switchable HOEs, whose diffractive properties can be controlled. Described herein is a method of combining light from two or more illumination sources. In one embodiment, a reflection-type HOE is illuminated by the first illumination source. The HOE diffracts light from the first illumination source into an output direction. Light from the second illumination source is transmitted through the HOE and onto a reflective optical element, which reflects the light back through the HOE and into the same output direction. Also described is a projection system that uses two or more HOEs to combine two or more colors of light for use by a single image display. The system includes one or more light sources, an image display (such as a reflective or transmissive LCD display or a MEMS display, for example), and a first and a second HOE.

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: An improved process for holography is provided, in which the reference beam used for storage and readout has a correlated phase content. In particular, it was found that reference beams having random phase content limited the attainable storage density and the accuracy of readout of stored holograms due to uncontrolled fluctuations in the correlation selectivity. By contrast, a reference beam having correlated phase content provides accurate shift selectivity, the ability to tailor the reference beam spectrum to minimize crosstalk between neighboring holograms, and mitigation of limitations inherent in the holographic system or holographic medium. Improved storage density and readout accuracy are thereby attained.

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 system for generating an image comprising an illumination system having a light source and a plurality of holographic devices switchable between an active state wherein light from the light source is diffracted by the device and a passive state wherein the light is not diffracted by the device. A display device is positioned for illumination by the illumination system and operable to project a display image. The system further includes an optical projection device operable to receive the displayed image and form an intermediate image having a generally uniform illumination distribution on an optical diffuser. The diffuser is operable to project a resultant image with an emission angle larger than an emission angle of the display panel.

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: A holographic memory system which utilizes the Talbot Effect for the lensless, near-field propagation of repeating image planes of periodic structures. Periodic phase structures at one plane in a holographic memory system are mapped to the input amplitude data plane in the holographic memory system. In a preferred embodiment, coherent light is passed through a lenslet array and propagated via the Talbot Effect to self-image coincident on a spatial light modulator that provides the holographic memory system with input data. The lenslet array is located relative to the spatial light modulator such that the desirable phase image structure is self-imaged in its Fresnel region onto the input amplitude data structure.

Abstract: A method and an apparatus for increasing detection signal-to-noise ratio, by reducing the effect of optical scatterers from a holographic storage medium, are disclosed. The method comprises the step of sensing the phase of scattered radiation and the subsequent step of writing the hologram data into the holographic storage medium. The image containing the hologram data is written with phase characteristics such that, during a subsequent hologram readout, the electric fields from the image and scatterers are 90 degrees out of phase. This optimum phase relationship greatly reduces the effect of scatter noise, thereby increasing signal-to-noise ratio and reducing bit-error-rate.

Abstract: Holographic optical elements (HOEs) can be used in systems and methods for providing illumination and for projecting images. The HOEs may be switchable HOEs, whose diffractive properties can be controlled. Described herein is a method of combining light from two or more illumination sources. In one embodiment, a reflection-type HOE is illuminated by the first illumination source. The HOE diffracts light from the first illumination source into an output direction. Light from the second illumination source is transmitted through the HOE and onto a reflective optical element, which reflects the light back through the HOE and into the same output direction. Also described is a projection system that uses two or more HOEs to combine two or more colors of light for use by a single image display. The system includes one or more light sources, an image display (such as a reflective or transmissive LCD display or a MEMS display, for example), and a first and a second HOE.

Abstract: The present invention provides a method, device and optical package (10,22) for enhancing a temperature stability by controlling a variable characteristic of an optical package and optical interconnect system.

Abstract: The invention relates to a method for replicating a volume hologram having an image of a scattering object recorded therein according to a hologram replicating technique, wherein the diffraction 13 of unnecessary light due to zero-order light, etc. arising from regular reflection and a visual range capable of viewing a recorded image is limited to a desired range .alpha., so that the image can be displayed more brightly than would be possible with the original hologram plate, and a volume hologram as well. When replicating a volume hologram 4' having an image O' of a scattering body recorded therein, replicating illumination light is incident on the volume hologram 4' at an angle of incidence I.sub.1 at which a group of fringes can be replicated and recorded, said group of fringes being such that, in the vicinity of an apex defined by a supposed slant angle S.sub.g at which a replicated hologram 4' can be viewed at a supposed viewing center angle .phi. within a range .alpha.

Abstract: A holographic display system comprising left and right optical systems is disclosed. The optical systems each comprise an image display operable to display an input image and first and second holographic devices. The first holographic device is operable to project the input image to overlap with the input image projected from the other of the left and right optical systems to form a resultant image with a first aspect ratio. The second holographic device is operable to project the input image to overlap with the input image projected from the other of the left and right optical systems to form a resultant image with a second aspect ratio, different from the first aspect ratio. A method of changing the aspect ratio of an image is also disclosed.

Abstract: In order to depict features such as pivoting and/or the flexure of elements of an article or articles which are enclosed within a package, at least one holographic generating layer is disposed on the package to provide an enlarged highlighted view of a portion of an image which is printed on the surface of the package. In accordance with the invention, it is also possible to have two holographic image generating layers overlaid one on the other and adhered to the surface of a package. The outer layer permit the images produced by the underlying layer to be also viewed, although at different angles from the images produced by the upper or outer layer. This permits the simulation of different movements which are exhibited by the article or articles enclosed within the package.

Abstract: A method for holographic data storage comprises the step of formatting a page with calibration marks as well as data patterns representing data. The page is then stored in a holographic storage medium. A method for holographic data retrieval comprises the step of detecting locations of the calibration marks. A mathematical function is fitted to the locations, and the function is used to compensate for distortion in the detected image of the page. In the preferred embodiment, the calibration marks are also used to generate an inverse point spread function that is used to digitally sharpen the detected image of the page. In the preferred embodiment, the data patterns are dispersed throughout the page by an interleaving algorithm, so that subsequent data patterns are not stored consecutively in the page.

Abstract: A method of designing a spatial phase modulation element which has a plurality of hologram surfaces with mutually different phase patterns, and a spatial phase modulation element produced in the method. The spatial phase modulation element is designed to have a variable-phase medium located on one side of each of the hologram surfaces and modulating means for modulating the phase patterns of the hologram surfaces independently of each other. Further, if the number of output patterns to be obtained with the spatial phase modulation element is n and if the number of hologram surfaces is N, the spatial phase modulation element is so designed as to meet the condition n.gtoreq.N+2, N.gtoreq.2.

Abstract: A method for coded-wavelength multiplexing according to which a signal waves S.sub.i (r) is recorded in a holographic medium in a counter-propagating geometry using corresponding writing reference waves R.sub.i (r). The method involves selecting discrete wavelengths .lambda. and encoding reference wave vectors .rho..sub.l which make up writing reference waves R.sub.i (r) such that the writing reference waves R.sub.i (r) at each wavelength .lambda. are orthogonal. The stored signal waves S.sub.i (r) are reconstructed in the form of reconstruction waves A.sub.c (.sigma.) with reconstruction reference waves R.sub.c (r) selected from among the writing reference waves R.sub.i (r). In the event of angular multiplexing of the reference wave vectors .rho..sub.l, it is possible to use one reference wave to produce a number of reconstruction waves A.sub.c (.sigma.) and generate a mosaic of desired holographic pages.

Abstract: The present invention uses a hologram superimposed on a traditional picture such as a photograph or printed picture. The hologram is more viewable at certain angle ranges than at others. This allows the hologram image, the picture or a combination of both to be seen at different angles, thus allowing different visual effects. In a preferred embodiment a pre-made multi-channel hologram is superimposed over a user's portrait photograph taken in a photo booth. The multi-channel hologram is aligned with the photograph so that by varying the viewing angle of the combined picture and hologram an interesting, entertaining or educational effect, such as transforming, or "morphing," the user's face into another face or image, is seen. For example, a portrait photograph of the user can morph into an animal's face, a skeleton, a scary beast, etc. The morphing, or transformation, effect is easily achieved by insuring that the hologram image is substantially aligned with the portrait photograph.

Abstract: An architecture for holographic data storage and processing integrates multifunctional silicon-based optoelectronic devices, rewritable holographic material, optical devices and other electro-optical elements in compact and high-performance systems. A dynamic hologram refresher based on optoelectronic integrated circuits has a smart pixel structure including an electrically addressed SLM to write a new data page, a thresholding detector array for readout, and a memory to latch the data from the detector to the modulator in each pixel. In particular, conjugate reconstruction is used in combination with the dynamic hologram refresher to retrieve data from volume multiplexed holograms in the rewritable holographic material.

Abstract: The invention is embodied in a method of recording successive holograms in a recording medium, using at least a fan of M waves along at least a first axis with a separation angle between adjacent waves and directing the fan of M waves as a reference beam along a reference beam path onto the recording medium, successively modulating a wave with a succession of images to produce a succession of signal beams along a signal beam path lying at a propagation angle relative to the reference beam path so that the signal and reference beams intersect at abeam intersection lying within the medium, the beam intersection having a size corresponding to beam areas of the reference and signal beams, producing a succession of relative displacements in a direction parallel to the first axis between the recording medium and the beam intersection of the signal and reference beam paths in synchronism with the succession of signal beams, each of the displacements being less than the size of the intersection whereby to record succ

Abstract: Selection of individual holograms during read-out of a multiplexed array depends upon varying relative position of the recording medium in the direction orthogonal to the medium surface.

Abstract: A color filter includes a plurality of color pixels, and a first hologram diffracting an incident light beam into a first diffraction-resultant light beam. The color filter also includes a second hologram diffracting the first diffraction-resultant light beam into a second diffraction-resultant light beam having a plurality of light beams with different wavelengths respectively. The second hologram directs the different wavelength light beams toward the color pixels respectively.

Abstract: A holographic planar concentrator (HPC) for collecting and concentrating optical radiation is provided. The holographic planar concentrator comprises a planar highly transparent plate and at least one multiplexed holographic optical film mounted on a surface thereof. The multiplexed holographic optical film has recorded therein a plurality of diffractive structures having one or more regions which are angularly and spectrally multiplexed. Two or more of the regions may be configured to provide spatial multiplexing. The HPC is fabricated by: (a) recording the plurality of diffractive structures in the multiplexed holographic optical film employing angular, spectral, and, optionally, spatial multiplexing techniques; and (b) mounting the multiplexed holographic optical film on one surface of the highly transparent plate. The recording of the plurality of diffractive structures is tailored to the intended orientation of the holographic planar concentrator to solar energy.

Abstract: A video image F?k! is identified as a basis image and stored as a basis page S?k! in a holographic storage medium. A subsequent image F?k+n! is stored by recording in the medium a page S?k+n!=F?k+n!-a?k!F?k!, where a?k!.noteq.0 and preferably a?k!=1. The page S?k! is recorded with a reference beam R?k!, while S?k+n! is recorded with a reference beam R?k+n! orthogonal to R?k!. The basis page is reset whenever the average intensity of a page to be stored exceeds a predetermined threshold. An image F'?k! is retrieved by reading basis page S?k! and letting F'?k!=S?k!. Subsequent images F'?k+n! are retrieved as S?k+n!+b?k!S?k!, where b?k!.noteq.0 and preferably b?k!=a?k!=1. The page addition step is performed coherently, i.e. by accessing the medium with a reference wave function R?k+n!+b?k!R?k!.

Abstract: As a combiner, a hologram prepared by exposure to light is used wherein a combination of the central wavelength .lambda., the halfwidth .DELTA..lambda. and the diffraction efficiency .eta. of the diffraction spectrum of light minimizes the color difference between the color tone of light from a light source and the color tone in average of reflection light by the combiner, when observed by changing the angle, or the sum of the square of the color differences between the color tone of the light from the light source when observed by changing the angle and the color tone of the reflection light by the combiner.

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 method of choosing an angle between a reference beam and a signal beam in a holographic storage apparatus is presented. The angle between the reference and signal beams can be optimized in light of crosstalk, scattering and wavelength seperation considerations.

Abstract: The present invention describes a method for high capacity holographic data storage in photorefractive crystals. A doped ferroelectric crystal is used as a data storage medium. Prior to the recording, the crystal is depoled either thermally or electrically. Multiplexed photorefractive holograms are then recorded by illuminating the crystal in such a manner that domain screening of the photorefractive space-charge field occurs. The crystal is then repoled to enable the reading of the holograms stored within the crystal. Finally, any given hologram is readout by illuminating the crystal at the Bragg condition, which typically occurs while illuminating the crystal at the same angle and/or wavelength at which the hologram was recorded.

Abstract: A method and apparatus (300) for making holograms includes a technique for exposing a film substrate (319) or other light sensitive medium to consecutive two-dimensional images, together representative of a 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 (319). Each image is relatively weak, but the combination of the series of weak images ultimately appears as a single clearly defined hologram.

Abstract: A holographic imaging apparatus having a pulsed laser light source for generating an object beam and a reference beam whereby an object, obscured by a diffusing medium, is illuminated by the object beam. A real time interferogram recording medium is exposed to the coincidence of light reflected from the object and the reference beam to record an interferogram. A holographic image is then reconstructed from the interferogram and may be viewed and recorded. The pulsed laser light source generates a beam which is divided by a conventional beam splitter device into an object beam and a reference beam. The object beam is then diverged by a lens which forms a diverging object beam to illuminate the object. The reference beam is diverged through another lens to form a diverging reference beam which is directed so that it illuminates a photoreactive crystal.

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: A polarizer plate including a polarizer substrate formed of a polarizer layer and supporting layers disposed on opposite surfaces of the polarizer layer; an undercoat layer disposed on one surface of the polarizer substrate; an anti-reflection layer disposed on the undercoat layer; and an anti-staining layer including a fluorine-containing silane compound disposed on said anti-reflection layer. The undercoat layer preferably has a specular glossiness according to JIS Z 8741 of from 10 to 40 and a haze according to JIS K 6900 of from 5 to 30%.

Abstract: A method of holographic recording in a photorefractive medium wherein stored holograms may be retrieved with maximum signal-to noise ratio (SNR) is disclosed. A plurality of servo blocks containing position feedback information is recorded in the crystal and made non-erasable by heating the crystal. The servo blocks are recorded at specific increments, either angular or frequency, depending whether wavelength or angular multiplexing is applied, and each servo block is defined by one of five patterns. Data pages are then recorded at positions or wavelengths enabling each data page to be subsequently reconstructed with servo patterns which provide position feedback information. The method of recording data pages and servo blocks is consistent with conventional practices. In addition, the recording system also includes components (e.g.

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 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: 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.