Abstract: A hologram recording method comprising recording information of signal light as a reflection-type hologram on an optical recording medium, by illuminating the signal light and reference light on a same axis and from different sides of the optical recording medium is provided. Further, a hologram recording device including: a signal light illuminating section illuminating signal light onto an optical recording medium; and a reference light illuminating section illuminating reference light of a same axis as the signal light, onto the optical recording medium from a different side than the signal light is provided.

Abstract: A hologram recording device for irradiating a recording beam (S) to a hologram recording medium (B) at a fixed incident angle (?s) and irradiating a reference beam (R) to an illuminated region (p) of the recording beam (S) by variably controlling an incident angle (?r) of the reference beam (R) on the hologram recording medium (B), whereby a hologram is recorded on the illuminated region (p) in multiple, includes at least a variable reflector (10) directing the reference beam (R) to the illuminated region by reflection and being swung around a predetermined axis (x) for changing the incident angle (?r) of the reference beam (R); and a light shield (11) being swung integrally with the variable reflector (10) for partially shielding the reference beam (R) so that a luminous flux diameter thereof becomes narrower as the incident angle (?r) becomes larger.

Abstract: Light emitted from a light source and passes through a collimating lens forms a parallel beam, which is reflected by a reflecting surface of a movable mirror. The parallel beam is made incident on a recording medium at a certain incident angle. The reconstructed light beam generated by Bragg diffraction caused by a hologram recorded in the recording medium is output at a certain output angle. The output reconstructed light beam is received by a flat photosensor, and information recorded in the form of a hologram is read out. By changing the angle of the movable mirror in at least two directions, the incident angle can be changed, and a hologram recorded in an angle multiplexed manner can be reconstructed. By changing the incident angle in a direction perpendicular to the displacement direction, an incident angle of a reconstruction reference light beam made incident on a hologram region is controlled.

Abstract: A monocular holographic storage device or system to provide for compact recording and/or reading of data pages in a holographic storage medium. Also provided are methods for carrying out such data storage and/or data recovery using a monocular holographic storage device or system. Further provided are articles comprising holographic storage media for recording or for reading recorded data using such devices or systems.

Abstract: A holographic recording device for multiple recording a plurality of interference fringes of a reference light and intensity-modulated signal lights in a same area or in areas slightly shifted each other of a holographic recording medium is disclosed. The holographic recording device modulates the intensity of a signal light and modulates a phase of the signal light before or after the intensity modulation. A phase distribution of each signal light is changed every time when multiple recording is performed and after each phase modulation, the recording device determines if an assigned multiplicity has been achieved.

Abstract: Systems and methods for shearless digital hologram acquisition, including an apparatus incorporating an illumination source configured to produce a first beam of light, which is then split by a beamsplitter into a reference beam and an object illumination beam. The reference beam is directed onto a phase-shaping optical element which imparts a phase shift to the reference beam and returns the phase-shifted reference beam on itself to the beamsplitter. The object illumination beam is directed onto an object, and a portion of the beam is reflected back to the beamsplitter, which combines the phase-shifted reference beam and object illumination beam substantially coaxially. The combined beams are passed through a focusing lens which focuses them at a focal plane. A digital recorder is positioned at the focal plane to record the spatially heterodyne hologram formed by the focused phase-shifted reference beam and reflected object illumination beam.

Abstract: A hologram reading apparatus includes: a unit for holding a hologram recording medium in which data page is recorded by irradiating as a single beam both reference light and signal light modulated by a spatial light modulator including a first pixel area for modulating the reference light and a second pixel area for modulating the signal light, a direction of an arrangement period of pixels in the first pixel area being different from that in the second pixel area; a Fourier transform lens subjecting reproduction light to a Fourier transformation; a filter disposed shielding the reference light at a first spatial frequency band and transmitting the signal light at a second spatial frequency band; and a unit for receiving the reproduction light and reading the data page modulated to the signal light included in the reproduction light.

Abstract: A multiplexed holographic recording apparatus of the present invention records multiplexed holograms in a plurality of recording regions that are formed on a holographic recording medium. In particular, the apparatus first records a predetermined number of multiplexed holograms in each of the recording regions formed in a predetermined range or an overall range of the holographic recording medium through holographic recording performed N times, and then performs the (N+1)th holographic recording in each recording region formed in the predetermined range or the overall range. When n other recording regions (where n=0, 1, 2, . . . ) are superimposed on each recording region formed on the holographic recording medium, a difference in the degree of multiplexing between the recording regions formed in the predetermined range or the overall range of the holographic recording medium does not exceed a predetermined value of n+1.

Abstract: HROM replication methods, devices or systems are disclosed herein. Also disclosed herein are articles comprising conical reference (reconstruction) beam hologram elements to generate conical or conical like reference (reconstruction) beams which may be used in such HROM replication methods, devices or systems. Further disclosed herein are articles comprising a target medium which may be used in such HROM replication methods, devices or systems.

Abstract: Disclosed is a holographic data storage device including holographic media for containing data, writing data to and reading data from. The storage device also includes at least one supplemental memory for containing at least a portion of a directory of the data contained in the holographic media. By locating directory information for the holographic media in a supplemental memory, areas of the holographic media that have not yet been written to can be determined prior to accessing the holographic media. In this way, activating photo-sensitive agents in unwritten areas of the holographic media can be avoided unless these areas are being written to.

Abstract: In recording of an interference fringe of a reference beam and a signal beam in a hologram recording medium, at the time of multiple recording of holograms in the same recording region by varying the angle of incidence of the reference beam on the hologram recording medium, the angular pitch of the incidence angle of the reference beam is varied according to the incidence angle of the reference beam in the manner of ??1, ??2, . . . , ??m?1, and is thereby set to a minimum in such a range as not to worsen crosstalk. This makes it possible to increase the degree of multiplexing when the movable angle of the reference beam is the same, and to narrow the movable angle of the reference beam when the degree of multiplexing is the same, as compared with the related art.

Abstract: The present invention relates to a holographic recording apparatus that records on a multiple basis information on a holographic memory. An object of the present invention is to provide a holographic recording apparatus capable of avoiding problems of recording error of data and destruction of the existing data, which will occur when the medium of the specification shortages is used.

Abstract: A method is disclosed to store information in a holographic data storage medium. The method supplies a holographic data storage medium and provides information. The method defines an Active storage portion for the holographic data storage medium and establishes a threshold access interval. The method determines if the information was last accessed within the threshold access interval. If the information was last accessed within said threshold access interval, the method then stores that information as one or more holograms encoded in said Active storage portion of the holographic data storage medium.

Abstract: The interferometer of the invention comprises a moving mirror 106 for rotating the direction of an illumination beam on an observed sample 114, and a reference beam interfering with a beam diffracted by the object 114 on a detector 111. The reference beam is tilted relative to the diffracted beam.

Abstract: A holographic storage drive of a holographic data storage system is configured to write and read holograms with respect to a plurality of locations of a holographic storage medium; and a control is configured to operate the holographic storage drive to write a known image aggregated with data in the form of a hologram to the holographic storage medium; to operate the holographic storage drive to read back the written hologram, employing a partial matched filter to cross-correlate the read-back image with the ideal version of the known image, excluding the remainder of the written hologram; and to determine whether the cross-correlation at least meets a write/readback threshold.

Abstract: A hologram device records information of an interference fringe of signal light and reference light onto a hologram recording medium and reproduces the recorded information by emitting the reference light onto a recording area of the hologram recording medium. The hologram device includes a recording/reproducing controller performing a recording operation of the information concurrently with a reproducing operation of previously-recorded information, and an error detector detecting an error in the previously-recorded information reproduced concurrently with the recording operation.

Abstract: An optical beam emitted from a laser light source is converted by a spatial filter to have a desired beam diameter, and converted by a collimate lens into a collimated beam. The optical beam rendered to be a collimated beam has its intensity adjusted by an ND filter. The optical beam having its intensity adjusted is lead by a mirror to an angle rotation mirror. The angle rotation mirror reflects the optical beam toward a hologram element. Holograms are recorded on the hologram element in advance, so that reconstructed beams are collected at a prescribed position irrespective of an incident position of the optical beam.

Abstract: The exposure amounts of R, G, and B laser light emitted from a fabrication light source are so adjusted that the diffraction efficiency at R, G, and B wavelengths in an optical element is commensurate with the light intensity at the R, G, and B wavelengths in the light emitted from a reproduction light source. For example, when the light intensity of the light emitted from the reproduction light source is increasingly low at the B, G, and R wavelengths in this order, the exposure amounts of the R, G, B, laser light emitted from the fabrication light source are so adjusted that the diffraction efficiency in the optical element is increasingly high at the B, G, and R wavelengths in this order. In this way, the hue of the light (reproduction light) obtained from the reproduction light source via the optical element can be adjusted to the hue desired with every reproduction light source used, while the most use is made of the light emitted from the reproduction light source actually used.

Abstract: The present invention relates to a method and apparatus for producing a hologram, in particular a dot matrix volume hologram. A holographic recording system (1) comprises a source of optical radiation (7), a transparent or partially transparent holographic recording medium 6 and an optical system (10). The recording medium (6) has a first side (25), a second side (26) and a recording volume (36), the second side (26) being opposite to said first side (25) and the recording volume (36) being between said sides (25, 26). The recording medium (6) is positioned between the source of optical radiation (7) and the optical system (10) so that the first side (25) is presented towards the source of optical radiation (7) and the second side (26) is presented towards the optical system. The source (7) is arranged to project incident optical radiation (20) onto the first side (25) and through the recording volume (36) towards the optical system (10).

Abstract: A holographic memory reproduction apparatus which makes a wavelength of a reproducing laser beam coincident with a wavelength of a laser beam used for holographic recording when information is reproduced from a holographic recording medium. In the holographic memory reproduction apparatus 10, a temperature adjustment device 26 is attached to a semiconductor laser 12. On the holographic recording medium 16, wavelength information of the laser beam used for recording is recorded as a wavelength address hologram 28. When the information is reproduced, the temperature adjustment device 26 is controlled by a wavelength control device 24 in accordance with a signal beam from the wavelength address hologram 28, thereby making an oscillation peak wavelength of the semiconductor laser 12 coincident with the wavelength of the laser beam used for recording.

Abstract: An array of discrete sensors disposed on a substrate, each sensor comprising a holographic support medium and a hologram disposed throughout the volume of the medium, whereby interaction with an analyte results in a variation of a property of the medium.

Abstract: The present invention relates to a reference beam coupler for an apparatus for reading from and/or writing to holographic storage media, to a multiplexing scheme using the reference beam coupler, and to an apparatus for reading from and/or writing to holographic storage media using such reference beam coupler or multiplexing scheme. According to the invention, the reference beam coupler has: a substrate; one or more optical fibers passing through the substrate for coupling one or more reference beams; and a reflective area on the substrate for reflecting an object beam, which serves as a Fourier filter for the object beam.

Abstract: A display device for a vehicle includes a transparent window with a light emission layer intended to separate the interior of the vehicle for emitting visible light when light is beamed onto the light emission layer, a light source for beaming light onto the window, a reflector mounted in a light path between the light source and the window to reflect the light generated by the light source and an adjustable image generator located between the light source and the reflector.

Abstract: A holographic storage medium includes a hologram including data recorded in a plurality of pages in a superimposed fashion by interference of a signal beam and a reference beam, and an additional page recorded between two adjacent pages in the plurality of pages, wherein a portion of the data is recorded to a region of the additional page having a relatively small selectivity compared to other regions of the additional page without recording on the other regions.

Abstract: A hologram recording and reconstructing apparatus includes a rotating mirror, a rectangular aperture and a medium drive unit, records interference fringes of a reference beam and a signal beam in a hologram recording medium and reconstructs the hologram recorded in the hologram recording medium. The rotating mirror changes the angle of incidence of the reference beam incident on the hologram recording medium such that multiple data is recorded in the same recording region of the hologram recording medium. The rectangular aperture blocks a reconstructed beam from a hologram adjacent to the hologram to be reconstructed. The medium drive unit drives the hologram recording medium such that the angle of incidence of the signal beam and the reference beam incident on the hologram recording medium is changed.

Abstract: A method is disclosed to store information in a holographic data storage medium. The method supplies a holographic data storage medium comprising an encoded focusing hologram and one or more encoded data holograms. The method disposes the holographic data storage medium in a holographic data storage system such that a moveable imaging lens is disposed at an (i)th position. The method illuminates the encoded focusing hologram to generate an (i)th reconstructed focusing image, projects that (i)th reconstructed focusing image through the moveable imaging lens, and onto said optical detector. The method then calculates an (i)th measured focusing metric, and determines if the (i)th measured focusing metric is greater than or equal to the threshold focusing metric. If the (i)th measured focusing metric is greater than or equal to the threshold focusing metric, then the method decodes the one or more encoded data holograms.

Abstract: In a printing apparatus, a recording material ejection nozzle is configured to eject a holographic recording material in dots onto a support, and a hologram recording optical system is configured to emit a plurality of beams of laser light simultaneously onto the holographic recording material ejected on the support by the recording material ejection nozzle to record interference fringes therein. A scanning drive unit is configured to move the recording material ejection nozzle and the hologram recording optical system relative to the support.

Abstract: A method for producing an optical element, preferably a security feature, wherein a film having a first embossed hologram in an embossing layer is provided, and a second embossed hologram is embossed into the same embossing layer such that the first embossed hologram is partly replaced with the second embossed hologram. The invention further relates to a method for producing an optical element wherein an embossable film provided with an embossed hologram is partly filled with printing lacquer, and a method for producing an optical element wherein hologram embossing is prevented by prior partial printing of the embossing film with curable printing lacquer. The invention relates further to optical features producible by the inventive methods, documents of value having an inventive optical feature and a numbering embosser for use in an inventive production method.

Abstract: The light energy necessary for the precure process is held by the RFID at the holographic memory. The controller acquires the light energy corresponding to the temperature of the recording position detected by the temperature sensor out of the precure information acquired by the RFID reader. The exposure time (light emitting time of LED) Te in the precure process is calculated based on the calculating equation Te (sec)=En (joule)/Pd (watt) from the energy En and the intensity Pd of light irradiated onto the recording position detected by the light detector.

Abstract: As a result of the light from a plurality of point light sources located at an identical position being refracted at a surface of a color correction prism at the time of exposure, the chromatic aberration occurring as a result of the light (for example, image light) directed via a refractive surface of the optical system used at the time of reconstruction to the viewer's pupil being refracted at this refractive surface is corrected for. Moreover, at least two of another set of a plurality of point light sources are arranged at such positions as to provide angles of incidence commensurate with the deviation between them of the ratio between exposure wavelength and use wavelength.

Abstract: The invention relates to a hologram that enables two or more different images to be simultaneously reconstructed even in a state where the hologram is fixed in terms of relative position with respect to an eye, and a holographic viewing device that incorporates it. The hologram 14 is fabricated by applying Fourier transform to a plurality of input image to obtain a plurality of corresponding Fourier transform images 13-1, 13-2 and arraying the Fourier transform images 13-1, 13-2 on the same plane according to a given two-dimensional array principle into a computer-generated hologram. When a plurality of point light sources 231 to 239 located behind the hologram 14 are viewed through the hologram 14, a plurality of images are simultaneously and parallel reconstructed (28) in correspondence to the array positions of the plurality of Fourier transform images.

Abstract: Provided are a photo detecting device and a holographic data reproducing apparatus for a multilayered holographic data storage medium using the photo detecting device. The holographic data reproducing apparatus, which can reproduce a large amount of information recorded in multiple layers of a holographic data storage medium, includes a focusing lens focusing a plurality reproducing signal beams generated when a reference beam is incident on the holographic data storage medium and having focal points formed at different locations on the same optical axis, a volume hologram device generating secondary signal beams which travel in different directions by diffracting a plurality of reproducing signal beams having different focal points, a fourier lens focusing the secondary signal beams generated from the volume hologram device, and an optical detector array detecting the secondary signal beams focused by the fourier lens.

Abstract: A recording medium records therein image data for distributing contents as element holograms with interference fringes generated by interference between an object beam representing the image data and a reference beam. The image data to be distributed which are recorded as the element holograms in the recording medium are reproduced by applying reference beams to the recording medium.

Abstract: There is provided a hologram recording method, including generating a signal light which is spatially modulated such that digital data is represented by an image of intensity distribution, irradiating the signal light on an optical recording medium after a Fourier transformation of the signal light such that a zero-order component of the signal light comes into focus at a point removed from the optical recording medium, forming a diffraction grating in the optical recording medium by interference between the zero-order component of the signal light and a high-order component thereof, and recording digital data represented by the signal light as a hologram.

Abstract: This invention relates to improved holograms, in particular suitable for security applications, and to methods and apparatus for their fabrication. A hologram storing a pair of images, the hologram comprising: a first stored image configured to replay at a first wavelength; and a second stored image configured to replay at a second wavelength different to said first wavelength; and wherein said first and second stored images are spatially complementary such that when replayed they appear together, substantially in register, and give the appearance of a single, substantially uninterrupted image.

Abstract: A security system comprises an intrusion detector for detecting an intruder on a premises, and a hologram image generator which produces a hologram image of a live object such as a person or guard animal in response to the detection of an intruder.

Abstract: A method and apparatus for recording and/or reproducing data to and/or from a holographic storage medium and a holographic storage medium therefor are provided. The method of reproducing data from the holographic storage medium, in which a hologram containing data is recorded through interference between a signal beam and a reference beam, the data being recorded in pages and a plurality of the pages being recorded in a book, includes controlling the reference beam so that an increasing/decreasing order of a reference beam in a current book which is currently reproduced is reverse to an increasing/decreasing order of a reference beam in a previous book which was reproduced before the current book, and reproducing pages of the current book from the holographic storage medium according to the controlling of the reference beam.

Abstract: A monocular holographic storage device or system to provide for compact recording and/or reading of data pages in a holographic storage medium. Also provided are methods for carrying out such data storage and/or data recovery using a monocular holographic storage device or system. Further provided are articles comprising holographic storage media for recording or for reading recorded data using such devices or systems.

Abstract: An optical information recording-reproduction process is provide in which a reflection type holographic memory disk is used and light receiving element and other elements are placed on the side of light-projection of the holographic memory disk. Thereby, the apparatus can be made smaller in its thickness.

Abstract: A method of detecting and compensating fail pixels in a holographic storage system. The method includes steps of: providing a plurality of image frames to show on a data plane for all pixels on the data plane being capable of outputting a light state or a dark state; sequentially recording the image frames into a storage medium; detecting the image frames by using a detecting apparatus for all pixels on the detecting apparatus being capable of outputting sensing signals corresponding to the light state and the dark state; defining a sensing difference value, which is a difference of the sensing signal outputting the light state and the dark state generated by one pixel; comparing the sensing difference value with a threshold value; and defining the corresponding pixel is a fail pixel if the sensing difference value is smaller than the threshold value.

Abstract: A method of writing a single or double parallax composite 1-step hologram is disclosed. Digital data is acquired from a real or virtual object and is described by a luminous intensity tensor. A single mathematical transformation is performed to convert the luminous intensity tensor into a mask tensor. The single mathematical transformation transforms the digital data whilst integrally correcting the digital data for the finite distortion of an optical objective. Corrected data, described by the mask tensor, is written on to a spatial light modulator. A laser beam is directed on to the spatial light modulator so that at least a portion of the laser beam is spatially modulated to form a spatially modulated laser beam. The spatially modulated laser beam is then passed through an optical objective having a finite distortion and in combination with a reference recording beam forms a composite hologram.

Abstract: A holographic data recording apparatus includes: a signal beam patterning unit for irradiating a signal beam onto a holographic medium, the signal beam including a data pattern to be recorded; a cylindrical optical body including a cylindrical reflective surface, by which a first and a second reference beams alternatively incident thereto at incident angles are reflected toward the holographic medium, alternatively; and an incident angle control unit for controlling the incident angles of the first and the second reference beams incident on the cylindrical optical body, wherein the data, pattern is recorded on the holographic medium by interfering the signal beam with the first and the second reference beams on the holographic medium. The holographic data recording apparatus do not require the replacement of the conventional conical mirrors while recording a plurality of data on a holographic medium, thereby increasing the recording speed and reducing the manufacturing cost thereof.

Abstract: An object of the invention is to prevent lowering of a dynamic range of a hologram recording medium without lowering an average data transfer rate, and to provide stabilized recording sensitivity. A scheduler determines a recording interval time from the point of time when light is irradiated to record a certain hologram of holograms to be multiplex-recorded to the point of time when light is irradiated to record a succeeding hologram in such a manner that at least parts of the holograms are recorded one over the other in a certain recording area. A recording interval time controller controls a light source to irradiate the light depending on the recording interval time determined by the scheduler.

Abstract: A recording and reproducing apparatus includes a reproduction signal detection unit reproducing a two-dimensional pattern previously recorded on a holographic recording medium or user data recorded on the holographic recording medium, a reference pattern storage unit previously storing a reference pattern to be provided when the two-dimensional pattern is reproduced, a correction information generation unit comparing a reproduction reference pattern signal corresponding to the reproduced two-dimensional pattern with the stored reference pattern and removing fixed distortion contained in the reproduction reference pattern signal to generate correction information used for reproducing the reference pattern from the reproduction reference pattern signal, a correction information storage unit storing the correction information, and a distortion correction unit performing a correction calculation for a reproduction data signal using the correction information to generate corrected reproduction data from which the

Abstract: A method and apparatus for producing holograms may use a computer generated 3-D model or data generated using multiple 2-D camera images taken of a real 3-D object or scene. The data is digitally processed and displayed on a high resolution spatial light modulator (SLM). A low energy pulsed laser records composite holograms on a holographic emulsion using a special optical design. Restricted or full parallax master transmission or reflection type composite holograms, known as H1 holograms, may be created that can be copied using traditional methods to produce full or single color rainbow white-light transmission holograms, achromatic white-light transmission holograms or single or full-color white-light reflection holograms.

Abstract: While Fourier transformation of a signal light beam is performed to perform recording during holographic recording so that a focal point is formed outside a holographic recording layer (defocus recording), an aperture is arranged on an outgoing side of the reproduced signal light beam (reproduction light beam), the reproduction light beam is focused at the aperture, and low-order components of a Fourier transform image of the reproduction light beam are selectively transmitted to detect only the transmitted light beam. Therefore, information recorded as the hologram in the holographic recording layer can be reproduced with high S/N ratio from the holographic recording layer added onto a support body, particularly onto a sheet member having non-optical quality such as paper and a plastic card.

Abstract: A small, inexpensive three-dimensional image display having a structure for displaying a color three-dimensional image sharply even if a low-resolution spatial optical modulating element is used. The three-dimensional image display has an illumination light source unit, a transmission spatial optical modulating element, a lens, and a mask. The illumination light source unit includes three point light sources outputting illumination light components having wavelengths (red, green, blue) different from one another. The point light source outputting the blue illumination light component of the shortest wavelength is disposed in position B(0, 0) on the optical axis of an illumination optical system, the point light source outputting the red illumination light component is disposed in position R(xr, 0), and the point light source outputting the green illumination light component is disposed in position G(xg, 0).

Abstract: In the hologram recording and hologram-record reproduction using a one-dimensional optical modulator, the one-dimensional optical modulator where a plurality of light-modulating pixels are arranged modulates a laser beam to record a digital-data signal on a hologram recording medium, and part of the light-modulating pixels record sync signals in two or more positions on the hologram recording medium with retaining a predetermined interval, thereby improving hindrance to reproduction or readout of information recorded on the hologram recording medium, a decrease in S/N, and so on due to deformation or the like of the hologram recording medium.

Abstract: A hologram is recorded by irradiating, with a reference light beam, a region corresponding to an intensity distribution of a signal light beam on an optical recording medium. For example, the reference light beam having the intensity distribution which substantially coincides with the intensity distribution of the signal light beam is generated, and only the region which substantially coincides with the region irradiated by the signal light beam (i.e., the signal light beam defocused region) is irradiated with the reference light beam. This enables only the necessary region to be exposed and the regions which need not be exposed not to be exposed. Accordingly, the hologram can be recorded without losing information of the signal light beam and thus high-density recording can be realized.

Abstract: The invention relates to a hologram that enables two or more different images to be simultaneously reconstructed even in a state where the hologram is fixed in terms of relative position with respect to an eye, and a holographic viewing device that incorporates it. The hologram 14 is fabricated by applying Fourier transform to a plurality of input image to obtain a plurality of corresponding Fourier transform images 13-1, 13-2 and arraying the Fourier transform images 13-1, 13-2 on the same plane according to a given two-dimensional array principle into a computer-generated hologram. When a plurality of point light sources 231 to 239 located behind the hologram 14 are viewed through the hologram 14, a plurality of images are simultaneously and parallel reconstructed (28) in correspondence to the array positions of the plurality of Fourier transform images.