Abstract: The present disclosure relates to a back light unit providing direction controllable collimated light beam and a three-dimensional display using the same. The present disclosure suggests a back light unit comprising: a light source for generating light; and a light direction controller for converting the light from the light source into a direction controlled collimated light beam having a refraction angle, the direction controlled collimated light beam emitted to a predetermined area to generate a three-dimensional holographic image. The back light unit according to the present disclosure can provide direction controllable collimation light having uniform brightness distribution over a large diagonal area of the spatial light modulator with thin and simple structure.

Abstract: A method and apparatus for reducing speckle noise in an image of an object are disclosed. The method includes, placing the object in an interferometer at a first position along a beam path of an object beam, irradiating the object with the object beam, moving the object from the first position to a second position by longitudinally shifting the object along the beam path of the object beam, irradiating the object with the object beam at the second position. At each of the first and second positions a holographic image formed by interference between the object beam and a reference beam is recorded. An object image with reduced speckle noise is obtained by averaging the holographic images. Either an arithmetic mean or a weighted average may be used in the averaging of the holographic images.

Abstract: Systems and methods for infrared laser holographic projection. In one example, an optical apparatus includes a first laser source configured to generate a first laser beam having a first wavelength in an infrared spectral range and a holographic medium optically coupled to the laser source and having a transmittance range including the first wavelength. A diffraction pattern formed in the holographic medium encodes an input image and is configured to diffract the first laser beam responsive to being illuminated by the laser beam so as to construct an image in the infrared spectrum, the image being a reconstruction of the input image. The diffraction pattern may further be configured to diffract a second laser beam having a second wavelength in a visible spectral range to construct an image including a first portion in the infrared spectral range and a second portion in the visible spectral range.

Abstract: Two adjacent images are recorded in a state smoothly blended at a boundary portion. On a recording plane Rec, provided is a region M1 in which an original image Pic(A) is recorded, a region M2 in which an original image Pic(B) is recorded, and a middle region Mm positioned therebetween. The region Mm is divided into a plurality of strip-like regions f1 to f6. The widths of the strip-like regions f1, f3, and f5 that are odd-numbered when counted from the region M1 are set so as to increase monotonically in this order, while the widths of the even-numbered strip-like regions f2, f4, and f6 are set so as to decrease monotonically in this order.

Abstract: According to one embodiment, a data reproducing apparatus includes a data recording medium, light source unit, light application unit, photodetector unit and control unit. An address mark string including address marks is formed on the data recording medium. The address marks are spaced from each other by a distance depending on address data. The light application unit is configured to split the light beam into a first branch light beam and a second branch light beam and apply the first and second branch light beams to the address mark string at different angles. The photodetector unit is configured to detect first reflected light beams and second reflected light beams from the address mark string to generate image data. The first and second reflected light beams result from the first and second branch light beams, respectively. The control unit is configured to reproduce address data based on the image data.

Abstract: A holographic security device including at least first and second diffractive image generating structures recorded in respective sets of substantially non-overlapping regions of a record medium, the regions of one set being interleaved with regions of the other set, whereby both interleaved regions are substantially non-visible to the unaided eye. The holographic security device generates two or more holographic images viewed from separate and/or overlapping viewing directions around the device and seen by tilting the device, and each particular holographic image in a viewing direction is generated by the diffractive image generating structure associated with one set of interleaved lines. The first diffractive image generating structure has been formed to have a diffuse diffractive replay and the second diffractive image generating structure has been formed to have a non-diffuse or specular diffractive replay.

Abstract: Device for generating a hologram pattern including: selecting means for selecting, as cross section ranges which are in a plurality of cross sections parallel to hologram pattern in 3D object and which are ranges used for generating hologram pattern, cross section ranges which overlap ranges in other cross sections when the relevant cross section is perspectively seen from a predetermined observation point on the hologram pattern; depth integrating means for calculating, for lattice points in one cross section range, a depth integral function acquired by integrating an inverse diffraction function for determining hologram pattern for displaying points of 3D object with respect to respective lattice points in the cross section ranges which overlap the relevant lattice point; and inverse Fourier transform means for generating hologram pattern by performing two-dimensional inverse transform on depth integral functions with respect to plurality of lattice points in one cross section range.

Abstract: A three-dimensional (3D) color display apparatus may include: light sources emitting different color beams; a volume diffractive element, in which a hologram is recorded using one of the color beams that is emitted from one of the light sources as a reference beam and a signal beam, displaying color images by diffracting the color beams emitted from the light sources; and a scanning unit scanning the color beams diffracted by the volume diffractive element. A 3D color image display method may include: recording holograms in a volume diffractive element using a first color beam as a reference and signal beam; irradiating the first color beam and another color beam onto the volume diffractive element as a reproducing reference beam; forming beam spots by diffracting the first color beam and the another color beam using the volume diffractive element; and scanning the color beams diffracted by the volume diffractive element.

Abstract: A multiwavelength holographic imaging apparatus uses a frequency converter for converting input tunable coherent light having a wavelength tunable around a wavelength ?2 to tunable output coherent light having a wavelength tunable around a wavelength ?1, wherein the image receiver receiving the holographic image is sensitive to the light of wavelength ?1. The image receiver may not be sensitive to light of wavelength ?2, for example if ?2 is in the infrared spectral region greater than 1.3 microns.

Abstract: Holographic display with which voice and holographic image over internet protocol (VHIOIP) services or communications are provided.

Abstract: An apparatus and method of image reconstruction are disclosed. The method includes first breaking a holographic image into a plurality of interlaced sample sets corresponding to color separation images; and independently sampling, filtering, and reconstructing all sets. The resulting demodulated images contain no fringes. Notably, range-clipped tonal rendering curves are used to choose pixel regions of the demodulated images that will replace saturated regions. The image is reconstructed by integrating all un-saturated images into one.

Abstract: A holographic projection system with an optical wave tracking system sets the propagation direction of a modulated wave uses a position control system and an eye finder. It provides an adjustable optical wave correction system which compensates for deformations of the wave which are dependent on the current eye position. Largely dynamic changes and deformations in the form structure of the modulated and conditioned wave are reduced, which result from changes in the propagation direction of the aligned, optically enlarged and modulated wave on a focusing display screen. The optical wave correction system includes adjustable wave form means and computer means which set the optical behavior of the wave form means using the positional data from the current eye position. The adjustable wave form means are located in the light path between an illuminating system for the spatial light modulation means and the display screen of the projection system.

Abstract: A forgery prevention medium includes a volume hologram layer on which an interference pattern is recorded after being exposed to an emitted laser beam; a digital watermarking information layer that can be interpreted by emitting a light beam with a predetermined wavelength; and an adherend that has the digital watermarking information layer and is attached to the volume hologram layer, wherein the information layer is of a different color from the volume hologram layer.

Abstract: The present disclosure relates to a spatial light modulating panel using a transitive liquid crystal display panel and a three-dimensional display device using the same. The present disclosure suggests a spatial light modulator comprising: a plurality of pixels arrayed in a matrix manner; and a liquid crystal layer configured to modulate phase of an incident light passing through the each pixel, respectively. The spatial light modulator and the 3D display using the same according to the present disclosure provides thin flat type display system having the easy and simple structure and the low manufacturing cost.

Abstract: A holographic reconstruction device is designed such that visible resolution of the reconstruction of a scene is matched to the resolution capability of the human eye, to the imaging properties of the reconstruction means used or to the resolution capability of the light modulation means used. A grid scale for the object points is generated by system control means in each case in a plane of intersection, which grid scale cannot be used to separately resolve adjacent object points in the plane of intersection, and the compilation of object points of the respective plane of intersection to form an object point group with adjacent object points which can be separately resolved is carried out. In holographic displays, the invention is used to reduce speckle patterns and reduce the number of the holograms of object points of the scene, which are to be calculated and coded, and the calculation complexity.

Abstract: A method for reconstructing a holographic projection including providing a single hologram, providing at least one cyclic shift of at least a portion of the single hologram in the space domain, and reconstructing a cyclically shifted hologram by applying said cyclic shift on said portion and providing at least one cyclic shift comprises computing the cyclic shift; wherein computing at least one cyclic shift includes creating an array of shifting points in a g-h plane of the single hologram and calculating a distance vector from an origin of the plane to the shifting point.

Abstract: This invention relates to holographic image display systems, and to related methods and processor control code. We describe a method of displaying an image holographically, the method including: inputting display image data defining said image for display; processing said image data to determine first image data representing a first spatial frequency portion of said image data and second image data representing a second spatial frequency portion of said image data, wherein said second spatial frequency is higher than said first spatial frequency; displaying a hologram of said first image data on a spatial light modulator (SLM) to form a holographically-generated intermediate real image; modulating said intermediate real image using said second image data to display said image.

Abstract: A hologram reproducing apparatus includes a first reference light path leading laser light from a laser light source so that a hologram recording medium is irradiated with first reference light; a diffracted light path leading diffracted light, generated from the hologram recording medium by irradiation with the first reference light, to a light receiving element having a plurality of pixels; and a second reference light path leading second reference light, having the same polarization direction as that of the diffracted light, from the laser light source to the light receiving element. The second reference light path is provided with a phase modulating element so that the phase difference between the diffracted light and the second reference light in a light receiving surface of the light receiving element is adjusted within a predetermined range.

Abstract: Holographic display device comprising a first EASLM and a second EASLM, the pair permitting independent modification of phase and amplitude, in which holographic reconstruction is visible through one or more virtual observer windows. An advantage is that an observer may view a holographic reconstruction through one or more virtual observer windows from a device housing a pair of EASLMs which permit independent modification of phase and amplitude.

Abstract: A holographic imaging system includes an electrical addressable spatial light modulator (EASLM) and an optically addressable spatial light modulator (OASLM). A read light is configured to illuminate the OASLM, and a controller is configured to address the EASLM with both positive and negative sub-images and transmit the positive and negative sub-images to the OASLM. The controller is further configured to address the OASLM with an operating voltage, wherein the read light generates a holographic image comprised of diffraction patterns from the positive and negative sub-images.

Abstract: A method and device for manufacturing a hologram recording medium. Arrangements are made to enable different original images to be reproduced upon observation from different positions and yet enable reproduced images of high resolution to be obtained.

Abstract: A device for producing a reflection hologram by means of a master, which is formed by a substrate on which a saw-toothed shaped structure is formed by molding, mechanical or lithographical methods. The structure has a reflective finish, such that the desired surface is produced on the structure. The light of a laser light source is expanded by means of an optical device, thus enabling a beam having a predetermined beam width to be obtained. The beam radiates the master and is reflected by the structure at an angle ? in relation to the incident beam. Above the smooth surface arranged over the structure a photopolymer-film, containing a photo-sensitive layer that is disposed at a distance in relation to the structure, is arranged and the reflection hologram is produced in the photo-sensitive layer.

Abstract: The present invention relates to a projection device for holographic reconstruction of scenes, said device comprising at least one light modulator device and at least one light source which emits sufficiently coherent light for the generation of a wave front of a scene, which is encoded in the light modulator device. A Fourier transform (FT) of the light which is emitted by the light source and modulated by the light modulator device is projected by a projection means on to a screen. Further, the wave front which is encoded on the light modulator device is projected by the projection means into at least one virtual observer window in an observer plane. For tracking the observer window according to a change in an eye position of the at least one observer, the inventive device comprises at least one deflection means, which is disposed between the light modulator device and the screen.

Abstract: Method for real-time rendering and generating of computer-generated video holograms from three-dimensional image data with depth information, where the position and viewing direction of an observer defines a view of the scene, and where the observer is assigned with at least one virtual observer window, which is situated in an observer plane near the observer eyes, comprising the following process steps: 3D rendering and generation of the depth map of scene section data between two parallel section planes, which are disposed at right angles to the viewing direction of the observer, transformation of the scene section data, repetition of the steps of 3D rendering and transformation, Back-transformation, encoding in pixel values in order to reconstruct the three-dimensional scene.

Abstract: A virtual image display device with an optical waveguide to guide, by internal total reflection, parallel pencil groups meeting a condition of internal total reflection, a first reflection volume hologram grating to diffract and reflect the parallel pencil groups incident upon the optical waveguide from outside and traveling in different directions as they are so as to meet the condition of internal total reflection inside the optical waveguide and a second reflection volume hologram grating to project the parallel pencil groups guided by internal total reflection inside the optical waveguide as they are from the optical waveguide by diffraction and reflection thereof so as to depart from the condition of internal total reflection inside the optical waveguide.

Abstract: A method is disclosed for reconstructing a 3D scene made of object points in a holographic display, wherein the reconstruction is visible from a visibility region. Visibility and/or covering of parts of the 3D scene corresponding to the real parameters is realized, with the reconstruction, for a viewer from every place of the visibility region. Processor means generate a spatial point matrix for defining the positions of individual object points, which are assigned predetermined intensity and phase values. Within the visibility region, a complex-value wave front for each single object point is calculated. The intensity values of the object points are multiplied with the associated visibility function, to determine a common modified wave front of the object points, transformed into the plane of a light modulator to calculate modified control values for the object points.

Abstract: A method for reducing speckle patterns of a three-dimensional holographic reconstruction is disclosed. A controllable light modulator into which a hologram of a three-dimensional scene is coded is illuminated by coherent light, a reconstruction lens transforms the modulated light into an eye position and reconstructs the three-dimensional scene in a reconstruction space and a control means controls the illumination. This provides a holographic reproduction device in which the speckle patterns occurring during reconstruction of a three-dimensional scene are reduced. According to one embodiment, a next-to-real time method is presented using a carrier medium of conventional image refresh rate.

Abstract: A method for reducing speckle patterns of a three-dimensional holographic reconstruction is disclosed. A controllable light modulator into which a three-dimensional scene is coded is illuminated by coherent light, a reconstruction means projects the modulated light close to an eye position into a space of observation and a control means controls the illumination. This provides a holographic reproduction device in which the speckle patterns occurring during reconstruction of a three-dimensional scene are reduced. Also provided is a next-to-real time method using a carrier medium of conventional image refresh rate.

Abstract: A holographic direct-view display system uses holographic integral imaging techniques that is an auto stereoscopic way to reproduce parallax and occlusion. The display is not resolution limited and is scalable to display life size images if desired. The system can be used to transmit 3D depictions of a scene at video and sub-video rates as well as other information, such as images of documents or computer generated images. The images may be captured, transmitted and displayed in real-time (or near real-time) for telepresence or stored for time-shifted display. The system combines integral holography, a pulsed laser to record the hologram at high speed and a dynamic refreshable holographic material such as a photorefractive polymer as a recording media. The system uses techniques to write, read and erase the updateable hologram that allow the holographic material, hence direct-view display to remain stationary throughout each of the processes for continuous presentation of the hologram to the audience.

Abstract: This invention relates to a holographic projection device with an array of mirror elements in the form of micro-mirrors. The holographic projection device comprises at least one light modulator device, which contains the array of mirror elements, for an enlargement of a reconstruction space for a reconstructed scene. Each mirror element is coupled with at least one actuator. The actuators tilt the corresponding mirror elements and/or displace them axially in at least one direction. Thereby, a wave front for the representation of a reconstructed scene is directly modulated. The holographic projection device comprises an optical system for the projection of the modulated wave front into at least one observer window in an observer plane.

Abstract: A projector includes: a laser light source that emits laser light; a condensing optical system that collimates the laser light; a holographic recording medium that, when laser light for reproduction is incident thereupon, emits a reproduced holographic optical image on the basis of a holographic image; a light modulation element that modulates the reproduced holographic optical image and emits the result to a projection optical system as an optical image for projection; a projection optical system that projects the optical image for projection; and a focal depth adjustment unit that adjusts a focus depth of the ray bundle projected by the projection optical system.

Abstract: The invention generally relates to accessories for portable electronic devices that offer a screen for displaying the contents of a display of an electronic device. The invention provides, for an electronic device, an accessory that includes a reflective screen including a material such as a beam splitter to re-display the device display. In certain aspects, the invention provides a reflective screen for use with a computing device that has a reflective material and a mechanism to hold the screen above a horizontal surface at an angle.

Abstract: A floating virtual hologram display apparatus, includes a scanning mechanism, a diffractive optical element and a reconstruction light source thereof. After a light beam emitted from the reconstruction light source passes through the diffractive optical element (DOE), and is diffracted by the DOE, a hologram beam spot will be displayed in front of the diffractive optical element; a floating virtual hologram is displayed after a position of the hologram beam spot is scanned and altered by the scanning mechanism; the floating virtual hologram being allowed to display a variable virtual image by controlling the reconstruction light source to emit bright, dark and different color of light corresponding to an image through the image signal processing unit.

Abstract: A floating virtual hologram display apparatus, includes a scanning mechanism, a diffractive optical element and a reconstruction light source thereof, where the scanning mechanism is installed with a scanning mirror. After a light beam emitted from the reconstruction light source passes through the diffractive optical element is diffracted by the diffractive optical element onto the scanning mirror, and then reflected by the scanning mirror, a hologram beam spot will be displayed in front of the scanning mirror; a floating virtual hologram is displayed in front of the scanning mirror after a position of the hologram beam spot is scanned and altered by the scanning mirror.

Abstract: In a holographic projection apparatus a virtual visibility region is magnified, for observing a reconstructed scene with at least one light modulation device and with at least one light source having sufficiently coherent light for generating a wavefront of a scene that is coded in the light modulation device. By means of imaging the wavefront into a viewer plane, it is possible to generate the virtual visibility region for observing the reconstructed scene. The virtual visibility region has at least two virtual viewer windows. In this case, the virtual viewer windows are dimensioned such that the reconstructed scene can always be observed without tracking of the viewer windows upon movement of a viewer in the viewer plane.

Abstract: A video holographic display device includes a light source used to illuminate a hologram-bearing medium encoded with a hologram. The device operates so that only when an observer's eyes are positioned approximately at the image plane of the light source can the holographic reconstruction be seen properly. This contrasts with conventional holographic displays, in which the observer's eyes do not have to be at the image plane in order for a holographic reconstruction to be seen.

Abstract: The image display device including a lighting unit having a plurality of light source units, a hologram optical unit, which reproduces light to form a plurality of screen images spatially apart from each other when light is incident from the lighting unit, and a display panel, which modulates light reproduced by the hologram optical unit according to image signals.

Abstract: A technique for recording data onto a hologram recording medium using spatial light phase modulation corresponding to the recording data, and a technique for reproducing recorded data by properly reading information on phases recorded on a hologram recording medium. A signal beam having a phase modulation pattern corresponding to recording data and a reference beam having a specific phase modulation pattern are applied to the recording medium. Thus, recording data can be recorded onto the hologram recording medium using phase information. In addition, at the time of reproduction, a reference beam and a direct current (DC) beam, whose phase difference with respect to the reference beam is ?/2, are applied to the hologram recording medium. By reading the reproduction beam to which the DC beam is added, recorded information on phases can be correctly read, and recorded data can be reproduced in accordance with the phase information.

Abstract: A holographic projection system has an optical wave tracking system which adjusts the propagation direction of a modulated wavefront. It provides an adjustable wave tracking system which aligns the modulated wave with a desired eye position of one or more observers and follows the movements of the observer. The system comprises spatial light modulation means which modulate a wave with holographic information for the purpose of holographic reconstruction. The optical wave tracking provides the light path of the modulated wave with a desired propagation direction which guides the modulated wave out of the reconstruction system via a light exit position of a display screen. Position control means set adjustable tracking mirror means in terms of their inclination to a reflection direction for reflecting the modulated wave and deflection means, which are located in the set reflection direction, reflect the wave via the display screen into the desired propagation direction.

Abstract: An apparatus for reading a data page from and/or writing a data page to a holographic storage medium includes a common aperture arrangement of one or more reference beams and an object beam or a reconstructed object beam. One or more spatial light modulators are provided for generating the one or more reference beams by modulating a light beam with a modulation pattern having a spatial frequency higher than the spatial frequency of the data page.

Abstract: A hologram medium manufacturing method that includes disposing a first pair of master hologram media with a predetermined interval so that the first pair of the master hologram media face each other; forming a master hologram in the master hologram media by irradiating the first pair of the master hologram media with spherical wave light and reference light so that the spherical wave light and the reference light interfere with each other in the master hologram media. The spherical wave light and the reference light have a focal point between the first pair of the master hologram media. The method also includes disposing a hologram medium between the first pair of the master hologram media; and forming a hologram in the hologram medium by irradiating the first pair of the master hologram media with the reference light.

Abstract: The apparatus includes a light source unit and a volume diffractive element diffracting beams emitted from the light sources unit so that spots of the beams can be formed at different positions from each other in a propagating direction of the beams diffracted by the volume diffractive element to scan the beams in a first direction.

Abstract: A display apparatus configured to produce an interactive three-dimensional holographic image is disclosed. The display apparatus can include one or more coherent light sources configured to produce one or more beams, based on obtained image data of an object to display, and a lens assembly configured to direct the one or more beams to form a holographic image of the object. The lens assembly can include a collimating lens and a lens capable of beam steering one or more beams, including a micro-lens assembly with at least one micro-lens configured to generate a plurality of beams associated with a plurality of desired viewing angles. One or more optical sensors can be configured to obtain information regarding whether an interactive device interrupts the one or more beams, and a processor unit can determine a location of the interactive device with respect to the holographic image.

Abstract: The exposure method includes the steps of: illuminating a hologram recording medium, in which a hologram with a first pattern has been recorded by illumination with a laser beam emitted from a first laser oscillator, with a laser beam emitted from a second laser oscillator; and delivering the laser beam emitted from the second laser oscillator, which has passed through the hologram recording medium, onto a resist, thereby forming a second pattern in the resist. The wavelength of the laser beam used for illuminating the resist through the hologram recording medium in which the hologram is recorded is shorter than the wavelength of the laser beam used for recording the hologram in the hologram recording medium. Further, the wavelength of the laser beam used for illuminating the resist is 1/(0.5×n) (where n is an integer not less than 3) that of the laser beam used for recording the hologram.

Abstract: A holographic device is provided for recovering data in a holographic memory system. The device use homodyne detection to introduce a local oscillator beam into a reconstructed data beam of the recovered hologram. An image of the combined beam comprising the reconstructed data beam and local oscillator beam may be processed to obtain contrast level information for the pixels of the detected image. This contrast level information may then be used to obtain an increased contrast image of the recovered hologram, which may increase the signal to noise ratio (SNR) of the recovered data.

Abstract: User input is facilitated through gestural inputs with displayed two and three-dimensional objects using a holographic device and film that displays a static, digitally generated, three-dimensional, autostereoscopic, full-parallax, real image and a digital projector that displays dynamic images. A system includes computer-detectable tags mounted on a user-wearable glove, and on a base plate that holds the holographic device. The system determines the locations of the tags, and calculates a location of a feature of the image based on the locations of the tags. The system also determines the location, pose, and gestural motion of the input device based on the location of the tags. The system further calculates a distance and direction between the input device and the feature of the image.

Abstract: Marketing communications are delivered by advertising displays affixed to or surrounding vehicular parking meters. Lease arrangements are determined by a machine-based method providing equitable revenue sharing to municipality or other entity owning the parking meter spaces and the marketing communication entity while providing rapid, reliable deployment to advertisers via a machine-based method of RFID tracking and deployment.

Abstract: An optical reader module includes a first illumination light source that emits reproducing illumination light to an image-capture target containing a hologram in which information reproduced in a predetermined angle area when illuminated from a predetermined angle is recorded, thereby reproducing the information recorded in the hologram; an image-capturing device that captures an image of the information reproduced from the hologram; and a first light-projecting unit that projects first-optical-guide-forming light on the image-capture target. A first optical guide projected on the image-capture target takes a predetermined shape when the emission angle of the reproducing illumination light to the hologram is equal to the predetermined angle.

Abstract: A method of manufacturing a master for producing a hologram device. A first master is produced with a compensating angle. The second master is produced from the first master with an index matching material to reduce the interference pattern caused by internal reflections within the holographic plate of the master. The hologram device has a relatively narrow angle of reconstruction to provide visibility from a nearly perpendicular light source such as the headlight of an on-coming vehicle.

Abstract: A holographic display including a spatial light modulator, and including a position detection and tracking system, such that a viewer's eye positions are tracked, with variable beam deflection to the viewer's eye positions being performed using a microprism array which enables controllable deflection of optical beams.