Having Optical Element Between Object And Recording Medium Patents (Class 359/30)
  • Patent number: 6903851
    Abstract: The present invention relates to a method for producing light-scattering elements by holographic illumination of a layer (10) of a photo-sensitive material on a support plate (1) and subsequent development of the layer (10) in order to generating a surface structure. The method is distinguished in that the illumination occurs using at least two mutually coherent luminous beams (2,3) which have passed through one or a plurality of primary diffusers (8,9) respectively were reflected at one or a plurality of primary diffusers, the luminous beams (2,3) being irradiated from different directions and being at least partially superimposed on the layer (10) while forming an interference pattern. This method permits producing diffusers having a leveled scatter profile in a simple manner.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: June 7, 2005
    Assignee: Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung e.V.
    Inventors: Volkmar Boerner, Andreas Gombert, Benedikt Bläsi
  • Patent number: 6894815
    Abstract: In accordance with teachings of the present invention, a device accomplishes the task of reducing or preventing reflections of the reference beam off a diffuser from striking the holographic recording material. First, the device absorbs a large percentage of the reference beam power so that portion of the reference beam never reaches the diffuser. Second, the device blocks the small amount of reference beam that is incident on the diffuser and reflects back toward the film. Thus, the proposed device operates as an absorber-blocker (AB) for the reference beam.
    Type: Grant
    Filed: May 24, 2002
    Date of Patent: May 17, 2005
    Assignee: Zebra Imaging, Inc.
    Inventors: Michael A. Klug, Deanna McMillen, Qiang Huang
  • Patent number: 6885510
    Abstract: Disclosed are holographic storage systems and lenses for holographic storage systems. The lens units can be of a two-component design. The lenses can be used to both record to photorefractive storage media and to read from photorefractive storage media.
    Type: Grant
    Filed: March 11, 2004
    Date of Patent: April 26, 2005
    Assignee: InPhase Technologies, Inc.
    Inventors: Jan Hoogland, Kevin Curtis
  • Patent number: 6870651
    Abstract: Apparatus for generating a dynamic image includes a laser light source for generating a coherent beam of light; optics for separating the light beam into a reference beam and an object beam; a lenslet light modulator, including an array of lenslets and a pixilated light modulator having a plurality of light modulating pixels associated with each lenslet in the array, the lenslet light modulator being located to modulate the object beam; image processing electronics for driving the lenslet light modulator with dynamic image data to produce a dynamic image at a recording plane; and optics for interfering the dynamic image and the reference beam at the recording plane to produce a hologram of the dynamic image in a holographic recording medium located in the recording plane.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: March 22, 2005
    Assignee: Eastman Kodak Company
    Inventors: Lee W. Tutt, Jason E. Anderson, Mitchell S. Burberry
  • Patent number: 6865002
    Abstract: An image exposure recorder for exposure-recording a holographic stereogram image or a hologram image on a recording medium for hologram. The recorder has an inverse correction system for rotating the polarization plane of a reference light (R) by means of a half-wave plate (11), directing the reference light (R) to a hologram recording medium (3), and measuring the intensity of a part of the reference light (R) transmitted through a polarizer (12) out of the reference light (R) transmitted through a part of the area of the hologram recording medium by means of a photodetector (13). In the inverse correction system, the angle of rotation of the half-wave plate is so determined that the intensity of the reference light (R) determined by the photodetector may be minimum or maximum.
    Type: Grant
    Filed: June 19, 2002
    Date of Patent: March 8, 2005
    Assignee: Sony Corporation
    Inventors: Nobuhiro Kihara, Megumi Ezura, Akira Shirakura
  • Patent number: 6842273
    Abstract: A hologram recording method using a beam with a very large incident angle includes the steps of generating a sheet beam as the reference beam, and introducing the reference beam into the recording medium at an incident angle of at least 70°. A hologram reproduction apparatus using a holographic reflector includes a light, a holographic reflector, an adjustor, and a hologram. Also, the hologram reproduction method using the hologram reproduction apparatus includes the steps of irradiating a beam emitted from a light source as a reference beam to a holographic reflector, reflecting the reference beam illuminated to the holographic reflector therefrom to generate a reconstructed beam, and allowing the generated reconstructed beam as a reference beam to pass through a hologram to reproduce the hologram. A flat display element apparatus comprises a light source, a holographic reflector, an adjustor, and a flat display element.
    Type: Grant
    Filed: May 6, 2002
    Date of Patent: January 11, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jong-man Kim
  • Publication number: 20040240013
    Abstract: Apparatus for generating a dynamic image includes a laser light source for generating a coherent beam of light; optics for separating the light beam into a reference beam and an object beam; a lenslet light modulator, including an array of lenslets and a pixilated light modulator having a plurality of light modulating pixels associated with each lenslet in the array, the lenslet light modulator being located to modulate the object beam; image processing electronics for driving the lenslet light modulator with dynamic image data to produce a dynamic image at a recording plane; and optics for interfering the dynamic image and the reference beam at the recording plane to produce a hologram of the dynamic image in a holographic recording medium located in the recording plane.
    Type: Application
    Filed: May 30, 2003
    Publication date: December 2, 2004
    Applicant: Eastman Kodak Company
    Inventors: Lee W. Tutt, Jason E. Anderson, Mitchell S. Burberry
  • Patent number: 6823113
    Abstract: A grating interference device with adjustable resolution has high stability and precision adjustment functions. The invention has two reflectors and a beam splitter. One of the reflector is installed on a rotating axis along with an optic fiber or a platform of planar waveguide. Through the rotating axis, this reflector and the platform are maintained at a fixed relative angle and rotate with respect to the other reflector and the beam splitter. The period of the interference grating is controlled by the angle change, producing a grating with a micrometer-order period on the optic fiber or the planar waveguide.
    Type: Grant
    Filed: September 13, 2002
    Date of Patent: November 23, 2004
    Assignee: Industrial Technology Research Institute
    Inventors: Ying-Tsung Lu, Ching-Chin Wu
  • Publication number: 20040218239
    Abstract: A holographic apparatus includes a mask for modulating a signal beam to generate a modulated signal beam; a conical prism, which has a cone portion and a base portion, for refracting a reference beam to generate a refracted reference beam, wherein the refracted reference beam interferes with the modulated signal beam in a holographic medium to thereby record data thereon, the base portion facing the holographic medium. The holographic apparatus can be miniaturized by a positional relationship between the conical prism and the holographic medium.
    Type: Application
    Filed: March 11, 2004
    Publication date: November 4, 2004
    Applicant: Daewoo Electronics Corporation
    Inventor: Jae-Woo Roh
  • Patent number: 6775037
    Abstract: A dot matrix system, which uses an electronic display panel as a diffractive optical device to produce two laser beams. The interference pattern of these two beams, at the focal plane of a lens, forms a grating spot with a shape and beam profile determined by the wavefronts diffracted by the electronic display device. The invention uniquely combines aspects of the interfering beam prior art and the prior art using an imaging display. Instead of simply reducing a diffraction image on a display device as in the imaging display prior art, the invention puts two different Fourier transforms on the display, the laser beam interacts with these Fourier transforms, and a lens focuses the two beams on the recording medium, with the two beams interfering with each other to produce the desired grating pattern. Because multiple orders of the wavefront will be produced by the display device, a light blocking element is used, with an aperture to pass only the desired order(s) of the beams.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: August 10, 2004
    Assignee: K Laser Technology, Inc.
    Inventor: Wai-Hon Lee
  • Patent number: 6762865
    Abstract: The invention is directed to self-referenced holographic recording techniques that make use of a diffusive element. Self-referenced holography refers to holographic recording techniques in which a reference beam is created from a zero frequency Fourier component of a data encoded object beam. In accordance with the invention, a diffusive element can be positioned in a holographic recording system to create the reference beam from the zero frequency Fourier component of the data encoded object beam. Using a diffusive element to create a reference beam in self-referenced holography can provide advantages to the self-referenced holographic recording system.
    Type: Grant
    Filed: February 7, 2003
    Date of Patent: July 13, 2004
    Assignee: Imation Corp.
    Inventor: Jathan D. Edwards
  • Patent number: 6747770
    Abstract: An illuminating optical system 36 evenly spreads an object beam L3 split from a beam splitter 34. When a control computer sends a number of images in the parallax direction, a spatial light modulation section (liquid crystal) 38 displays these images in that number of divisions under control of the control computer. A superposed projection optical system 39 superposes and projects light beams passing through the spatial light modulation section 38. A beam-condensing projection optical system 41 condenses a projected image's beam from the superposed projection optical system 39 in the parallax direction and forms this image in the non-parallax direction on the surface of a hologram recording medium 42.
    Type: Grant
    Filed: June 7, 2001
    Date of Patent: June 8, 2004
    Assignee: Sony Corporation
    Inventor: Nobuhiro Kihara
  • Patent number: 6738170
    Abstract: An optical member 7 is bonded, at its rear side 7b, to a holographic stereogram 6. The front side 7a of the optical member 7 consists of parallel triangular prisms. Illumination light 9 is applied to the front surface 7a of the optical member 7 at a predetermined angle of, for example, 60°. The optical member 7 is made of, for example, optical glass or transparent plastic. Each triangular prism has an incidence surface 8, to which the illumination light is applied at right angles. The illumination light is applied to the interface 22 between the optical member 7 and the holographic stereogram 6, at an incidence angle &thgr; of, for example, 60°, thereby to suppress surface reflection of the illumination light 9 at the interface 22.
    Type: Grant
    Filed: July 18, 2001
    Date of Patent: May 18, 2004
    Assignee: Sony Corporation
    Inventors: Nobuhiro Kihara, Akira Shirakura
  • Publication number: 20040067419
    Abstract: A holographic recording medium includes a holographic recording carrier including a first light transmittable substrate, a second light transmittable substrate and a holographic recording layer sandwiched therebetween, a first antireflection film formed on the surface of the first light transmittable substrate and a second antireflection film formed on the surface of the second light transmittable substrate, and optical characteristics of the first antireflection film and those of the second antireflection film are determined to be different from each other the thus constituted holographic recording medium can achieves improved data recording characteristics and data reproducing characteristics using an object beam and a reference beam, and concurrently enables desired positioning of an object beam and a reference beam, or only the reference beam, and detection of the address of the region in which data are being recorded or from which data are being reproduced using a position control beam.
    Type: Application
    Filed: October 1, 2003
    Publication date: April 8, 2004
    Applicant: TDK Corporation
    Inventor: Tetsuro Mizushima
  • Patent number: 6706451
    Abstract: A new photopolymerizable material allows single-step, fast recording of volume holograms with properties that can be electrically controlled. Polymer-dispersed liquid crystals (PDLCs) in accordance with the invention preferably comprise a homogeneous mixture of a nematic liquid crystal and a multifunctional pentaacrylate monomer, in combination with photoinitiator, coinitiator and cross-linking agent. Optionally, a surfactant such as octanoic acid may also be added. The PDLC material is exposed to coherent light to produce an interference pattern inside the material. Photopolymerization of the new PDLC material produces a hologram of clearly separated liquid crystal domains and cured polymer domains. Volume transmission gratings made with the new PDLC material can be electrically switched between nearly 100% diffraction efficiency and nearly 0% diffraction efficiency. By increasing the frequency of the switching voltage, switching voltages in the range of 50 Vrms can be achieved.
    Type: Grant
    Filed: March 2, 1998
    Date of Patent: March 16, 2004
    Assignee: Science Applications International Corporation
    Inventors: Richard L. Sutherland, Lalquidi V. Natarajan, Vince P. Tondiglia, Timothy J. Bunning
  • Patent number: 6674555
    Abstract: Apparatus for holographic recording of information includes a lens or lens system, referred to here as the “FT lens,” situated in such a way that light from an object beam enters the FT lens after passing through an object, and light leaving the FT lens impinges on a recording medium situated at a Fourier transform plane of the object with respect to the FT lens. Disclosed apparatus includes a phase element effectively juxtaposed with the object, in which the phase element is effective for redistributing object-beam intensity in the Fourier transform plane, and the phase element has a correlation length greater than a maximum pixel side length associated with the object. Disclosed apparatus includes an optical element or optical system, referred to here as a “power optic,” that adds convergence or divergence to the object beam before the object beam enters the FT lens.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: January 6, 2004
    Assignee: Lucent Technologies Inc.
    Inventors: Kevin Richard Curtis, Partha Pratim Mitra, Michael C. Tackitt
  • Patent number: 6674554
    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.
    Type: Grant
    Filed: October 4, 2001
    Date of Patent: January 6, 2004
    Assignee: Voxel, Inc.
    Inventor: Stephen J Hart
  • Publication number: 20030189740
    Abstract: Disclosed are holographic storage systems and lenses for holographic storage systems. The lens units can be of a two-component design. The lenses can be used to both record to photorefractive storage media and to read from photorefractive storage media.
    Type: Application
    Filed: September 19, 2002
    Publication date: October 9, 2003
    Applicant: InPhase Technologies, Inc.
    Inventors: Jan Hoogland, Kevin Curtis
  • Patent number: 6618175
    Abstract: A bright holographic stereograin having a high diffraction efficiency can be prepared by restricting vibrations. The apparatus comprises: an optical system 15 for letting an objective laser L2 beam subjected to image-modulation based on each image of a parallax image sequence and a reference laser L3 beam having coherence with respect to the objective laser beam L2 enter into a recording medium 3 and for recording interference fringes generated by the objective laser beam L2 and the reference laser beam L3, as a hologram element, onto the recording medium 3; an anti-vibration support means 19 for supporting the optical system 15 on a casing 20 while preventing vibrations; and cooling means 48 to 52 for cooling the optical system 15.
    Type: Grant
    Filed: March 6, 2000
    Date of Patent: September 9, 2003
    Assignee: Sony Corporation
    Inventor: Akira Shirakura
  • Publication number: 20030156307
    Abstract: A system for recording and reading out holograms in a storage medium comprising a pattern encoder, a first fourier transform lens with a focal length f1, a second fourier transform lens with a focal length f2, a detector array, and a first and second prism. The first prism is located between the pattern encoder and the first fourier transform lens, wherein the optical length between the pattern encoder and the first fourier transform lens through the first prism is equal to a back focal length BFL1. The second prism located between the second fourier transform lens f2 and the detector array, wherein the optical path length between the second fourier transform lens and the detector array through the second prism is equal to a back focal length BFL2.
    Type: Application
    Filed: September 27, 2002
    Publication date: August 21, 2003
    Inventors: Miller Schuck, Curt Shuman, Aaron Wegner, Michael Tackitt
  • Patent number: 6597478
    Abstract: A phase-conjugate holographic data storage device capable of enhancing the characteristics of recording and reproducing data by using a focusing lens is provided. The holographic data storage device includes a focusing lens which focuses an object beam having data, a spatial light modulator which is located on the optical path of the object beam passing through the focusing lens and modulates the object beam, and a data recording medium which records an interference pattern generated by interference between a reference beam and the object beam passing through the spatial light modulator and converging into a focus. The focusing lens is a focusing lens having at least two different focuses. The holographic data storage device is capable of effectively reducing a dc term having a bad influence on the characteristics of recording data, minimizing the size of a data unit, that is, a spot, and thus enhancing the density of recording data.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: July 22, 2003
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Ji-deog Kim, Hong-seok Lee, Suk-han Lee
  • Publication number: 20030123116
    Abstract: Disclosed are methods of producing obliquity corrected light beams, and holographic recording and retrieval systems that utilize a obliquity corrected reference beam. The obliquity correction is accomplished using off-center lenses.
    Type: Application
    Filed: August 5, 2002
    Publication date: July 3, 2003
    Applicant: InPhase Technologies, Inc.
    Inventor: Curtis Alan Shuman
  • Publication number: 20030031112
    Abstract: An object of the invention is to provide an optical pick-up device for recording and reproducing information through the use of holography, which can prevent deterioration of recording and reproduction accuracy due to vibrations from exterior or fluctuations in the relative positional relationship with a recording medium.
    Type: Application
    Filed: September 11, 2002
    Publication date: February 13, 2003
    Inventor: Hideyoshi Horimai
  • Publication number: 20030017421
    Abstract: A method and apparatus for forming a device in a substrate having grating structure, includes a substantially coherent and collimated light source, a mirror having a non-planar surface, and a substrate. The mirror, substrate, and stationary light source are disposed in fixed position with respect to one another. The components are arranged such that some light beams from the light source are projected directly onto the substrate surface and other light beams are reflected from the mirror surface onto the substrate surface. The respective beams converge at the substrate surface at different interference angles across the substrate surface. The different interference angles produce an interference pattern having a varying interference period which preferably uniformly increases or decreases across the substrate. The corresponding grating structure formed within the substrate using this interference pattern, therefore also includes the varying grating period. The device formed in the substrate may be a laser.
    Type: Application
    Filed: July 18, 2001
    Publication date: January 23, 2003
    Inventor: Miri Park
  • Patent number: 6509983
    Abstract: Systems and methods for adjusting the polarization of one or more recording laser beams can correct (in whole or in part) for the changes in the polarization of the recording laser beam(s) caused by changes in the dominant polarization direction within the film substrates used for recording holograms. Using information about the dominant polarization direction of portions of holographic film substrate, a polarization adjusting device can be used to adjust the polarization of the recording laser beam(s) to compensate for the effects that changes in the dominant polarization direction of the holographic film substrate have on the recording laser beam(s) and thus the recorded hologram.
    Type: Grant
    Filed: February 13, 2001
    Date of Patent: January 21, 2003
    Assignee: Zebra Imaging, Inc.
    Inventor: Michael A. Klug
  • Publication number: 20020135832
    Abstract: The invention presents the concept of self-referenced holographic data recording. In exemplary embodiments, the invention comprises methods of recording holograms on holographic data storage media; media produced by such methods; and self-referencing holographic data storage systems. A method of recording data in a holographic recording medium may comprise illuminating a medium with a data encoded first optical beam, optically directing a zero frequency Fourier component of the first optical beam to create a second optical beam, and illuminating the medium with the second optical. In some embodiments, for example, a self-referencing holographic data storage system has a single optical path directed towards a medium.
    Type: Application
    Filed: March 20, 2001
    Publication date: September 26, 2002
    Applicant: Imation Corp.
    Inventor: Jathan D. Edwards
  • Patent number: 6449067
    Abstract: A cartridge for holding a hologram-image recording medium for use with a hologram-image recording apparatus, including locating means for properly positioning said cartridge, for sequentially exposing and recording interference fringes generated by an object laser beam modulated in accordance with each element image of parallax images and a reference laser beam having coherency with respect to the object laser beam is provided. The cartridge includes a light shielding case capable of shielding external light from inside the cartridge. The case also defines an unreeling opening. A core is positioned within the cartridge around which the hologram recording medium is wound. The hologram recording medium is unreeled from the core to an exposing and recording portion of the hologram-image recording apparatus through the unreeling opening when the cartridge is mounted on the hologram-image recording apparatus.
    Type: Grant
    Filed: June 28, 1999
    Date of Patent: September 10, 2002
    Assignee: Sony Corporation
    Inventors: Akira Shirakura, Hirotsugu Suzuki
  • Patent number: 6441930
    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.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: August 27, 2002
    Assignee: Voxel, Inc.
    Inventor: Stephen J Hart
  • Patent number: 6414764
    Abstract: A method and apparatus is disclosed for creating a structure, such as a grating (45) in a photosensitive material (40). The method and apparatus relies upon creating at least two coherent beams of light (33, 38) and reflecting them, in a counter propagating manner, around a series of reflective elements (35, 37) along substantially equivalent paths so that the coherent beams interfere at a structure staging area (45). The structure staging area can then be utilized to create grating structures or the like having improved qualities.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: July 2, 2002
    Inventor: Francois Ouellette
  • Publication number: 20020080433
    Abstract: In a light unit that converts a false linear light into which a light from a point light source has been converted by a columnar light guide, into a planar light by a plate-shaped light guide, the point light source is arranged only at an end of the columnar light guide at which an angle between a longitudinal direction of the columnar light guide and ridge lines of recesses and projections forming a prism surface is obtuse. Thus, a positional relationship between the point light source and the ridge lines is set so that a main irradiation direction of band-shaped light emitted from the columnar light guide and which has been obtained by converting the light from the point light source to a false linear light is not substantially orthogonal to the ridge lines of the recesses and projections forming the prism surface of the plate-shaped light guide. Consequently, light obtained by totally reflecting this band-shaped light is unlikely to be viewed.
    Type: Application
    Filed: December 21, 2001
    Publication date: June 27, 2002
    Applicant: NEC Corporation
    Inventor: Masatake Baba
  • Publication number: 20020071145
    Abstract: The holographic digital data storage system is compatible with a CD/DVD player. A polarization direction of the beam is altered by a first wave plate and the size of the polarized beam is expanded by a beam expander. The expanded beam is split into a vertical polarized beam and a horizontal polarized beam by a polarization splitter; a polarization direction of the horizontal polarized beam is altered by a second wave plate. An optical path of the vertical polarized beam is adjusted by a first mirror to generate a first path-controlled beam; an optical path of a third directional polarized beam is controlled by a second mirror to generate a second path-controlled beam; the first and the second path-controlled beams are concentrated by using a first and a second lenses, respectively; and the interference of two beams is recorded on a medium.
    Type: Application
    Filed: March 2, 2001
    Publication date: June 13, 2002
    Inventor: Jae-Woo Roh
  • Patent number: 6382798
    Abstract: An optical device for projection display system comprising: a LCD projector, a luminescent spot projector for forming a luminescent spot on a screen, a luminescent spot extracting means for extracting light from the luminescent spot out of a reflected light from the screen, a luminescent spot detecting means for detecting the reflected luminescent spot and a luminescent control means for controlling a display image forming operation of the LCD projector based on the detection signal wherein the luminescent spot extracting means is an holographic mirror optically processed at, at least one wavelength of the luminescent spot projector.
    Type: Grant
    Filed: April 18, 2000
    Date of Patent: May 7, 2002
    Assignee: Universite de Liege
    Inventor: Serge Habraken
  • Patent number: 6369920
    Abstract: A system and method to divert a reference beam from intersecting with a diffuser disposed adjacent to a holographic recording material for recording a hologram. The invention includes a thin holographic deflector designed to deflect the reference beam away from the diffuser and to prevent the reference beam's passage and impingement onto the diffuser surface. The holographic deflector is designed to deflect only light impinging on it from the particular angle that the reference beam strikes the holographic recording material, and to transmit nearly all other light striking it. The deflector eliminates artifacts from the resulting hologram introduced by the reflected reference beam, while allowing the diffuser to be placed very close to the holographic material.
    Type: Grant
    Filed: August 10, 2000
    Date of Patent: April 9, 2002
    Assignee: Zebra Imaging, Inc.
    Inventor: Michael A. Klug
  • Patent number: 6366278
    Abstract: A picture recording device includes at least one photodetector for each picture element to be recorded before which one focusing element is arranged for forming an image of each element of the picture to be recorded on the photodetector. The picture recording device is fabricated as a thin, preferably flexible sheet and, on the side facing away from the picture to be recorded, further focusing elements are arranged in such a way that light emitted from a screen having the picture recording device mounted thereon is focused in a plane situated inside or directly in front of the picture recording device, ensuring an undisturbed viewing of the picture.
    Type: Grant
    Filed: November 17, 1999
    Date of Patent: April 2, 2002
    Assignee: Deutsche Telekom AG
    Inventors: Hans Wilfried Peter Koops, Ottmar Hoinkis
  • Patent number: 6356854
    Abstract: Systems and methods for determining the position and classification of an object and which may provide signals that control deployment of an active restraint device, for example. Using a pulsed laser light beam from a laser source that is spread and preferably diffused to avoid ocular damage, an interference pattern is returned to a sensing module through a spectral filter. There it is optionally combined with a reference beam from the laser source, modified to emulate coherence length effects, and incident upon a phase transmission holographic template that may be segmented into regions for example. Each region of the holographic template contains Fourier transform images of occupant types. Behind the holographic template is a detector array that is sensitive to the laser light. An interference pattern derived from the object is convoluted or cross-correlated with the template. When an match occurs, a bright spot appears on the detector array.
    Type: Grant
    Filed: April 5, 1999
    Date of Patent: March 12, 2002
    Assignee: Delphi Technologies, Inc.
    Inventors: Peter James Schubert, Michelle Lee Copeland
  • Publication number: 20020012136
    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.
    Type: Application
    Filed: April 2, 2001
    Publication date: January 31, 2002
    Inventors: Nobuhiro Kihara, Akira Shirakura
  • Publication number: 20020008889
    Abstract: A description is provided of an optical information recording and reproducing apparatus employing a holographic memory. The apparatus includes a mask disposed in an optical path of the signal light beam so as to cover a light intensity distribution of the signal light beam incident into the holographic memory at nearly a half portion thereof with respect to the center of the distribution of the zeroth-order diffracted light of the signal light beam. The center of a region of the holographic memory where the signal light beam and the reference light beam intersect with each other, is shifted by a distance substantially equal to twice the distance between peaks of the zeroth-order diffracted light or the first-order diffracted light of the signal light beam.
    Type: Application
    Filed: August 10, 2001
    Publication date: January 24, 2002
    Applicant: Pioneer Corporation, a Japanese corporation
    Inventors: Satoru Tanaka, Tomomitsu Kouno, Hideki Hatano, Yoshihisa Itoh, Hajime Matsushita, Takashi Yamaji
  • Patent number: 6330086
    Abstract: A digital holography device, applicable for example to the 3D mapping of objects, is used to determine the complex amplitude of a signal wave coming from an object illuminated by a known illumination wave. For this purpose, the device includes a source for the generation of two mutually coherent waves, the object illumination wave and a reference wave, the two waves having a phase difference &phgr;i(t) that is a function of time. The device also includes a mechanism configured to induce an interference, on a detection device, between the reference wave and the signal wave coming from the object. The detection device enables a temporal sampling of the interference pattern resulting in the acquisition of a number N of interferograms, N being greater than or equal to 2.
    Type: Grant
    Filed: April 5, 2000
    Date of Patent: December 11, 2001
    Assignee: Thomson-CSF
    Inventors: Laurent Collot, Frédérique Le Clerc, Michel Gross
  • Patent number: 6330088
    Abstract: The present invention concerns methods and devices for creating and printing variable size and variable resolution holographic stereograms and holographic optical elements using computer rendered images of three-dimensional computer models or using computer processed images. The present invention is an apparatus and method for printing one-step, full-color, full-parallax holographic stereograms utilizing a reference beam-steering system that allows a reference beam to expose a holographic recording material from different angles. More particularly, a coherent beam is split into object and reference beams. The object beam passes through an object beam unit in which a rendered image is displayed, while the reference beam passes through the reference beam-steering system. The object and reference beams interfere with each other at an elemental hologram on a holographic recording material.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: December 11, 2001
    Assignee: Zebra Imaging, Inc.
    Inventors: Michael Klug, Mark Holzbach, Alejandro Ferdman
  • Patent number: 6301028
    Abstract: A description is provided of an optical information recording and reproducing apparatus employing a holographic memory. The apparatus includes a mask disposed in an optical path of the signal light beam so as to cover a light intensity distribution of the signal light beam incident into the holographic memory at nearly a half portion thereof with respect to the center of the distribution of the zeroth-order diffracted light of the signal light beam. The center of a region of the holographic memory where the signal light beam and the reference light beam intersect with each other, is shifted by a distance substantially equal to twice the distance between peaks of the zeroth-order diffracted light or the first-order diffracted light of the signal light beam.
    Type: Grant
    Filed: March 23, 2000
    Date of Patent: October 9, 2001
    Assignee: Pioneer Corporation
    Inventors: Satoru Tanaka, Tomomitsu Kouno, Hideki Hatano, Yoshihisa Itoh, Hajime Matsushia, Takashi Yamaji
  • Patent number: 6301026
    Abstract: The purpose is to provide an illumination device for constructing a compact, light weight and inexpensive display device. The illumination device is provided with a light source for emitting light, and a holographic optical element for deflecting entering light to form light to illuminate a rectangular region, wherein the holographic optical element is arranged in contact with either the top or the bottom surface of a glass plate, and light emitted from the light source enters the glass plate through a side surface of the glass plate and is directed to the holographic optical element, such that the principal rays of the light enter the holographic optical element approximately perpendicular relative to one diagonal of the rectangular region.
    Type: Grant
    Filed: November 18, 1999
    Date of Patent: October 9, 2001
    Assignee: Minolta Co., Ltd.
    Inventor: Hiroaki Ueda
  • Patent number: 6297894
    Abstract: This invention discloses optical system and method for writing a refractive index pattern in a light transmissive or light absorbing sample. A light source for providing a short pulse laser beam in the femtosecond range having a low power per unit area is coupled to provide the short pulse beam to a diffractive optical element. A curved mirror collects light transmitted through or reflected from the diffractive optical element preserves an image relating to characteristics of the diffractive optical element encoded within the collected light, and directs the collected light in wavelength independent manner while preserving the image of the diffractive optical element encoded within the collected light. A rod lens demagnifies the image within the light received from the curved mirror so as to increase its power per unit area when directed to the light transmissive or absorbing sample to be permanently impressed therein.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: October 2, 2001
    Inventors: R. J. Dwayne Miller, Gregory D. Goodno
  • Patent number: 6293898
    Abstract: Holographic memory including a plurality of HOEs stacked in a vertical direction for two dimensional addressing of a recording medium for increasing a recording capacity and improving productivity and cost.
    Type: Grant
    Filed: August 25, 1999
    Date of Patent: September 25, 2001
    Assignee: LG Electronics Inc.
    Inventor: Keun Young Yang
  • Patent number: 6288805
    Abstract: A holographic projection screen for large screen projection and back projection with a liquid crystal projector. The screen includes at least one layer made of a photosensitive material in which at least one index grating may be recorded by an interference of an optical recording wave with an optical object wave. The thickness of the layer is equal to or greater than n0&Lgr;2/2&pgr;, where n0 is the average index of the photosensitive material, &Lgr; is the average spacing of the index grating and &lgr; is the recording wavelength.
    Type: Grant
    Filed: February 15, 1996
    Date of Patent: September 11, 2001
    Assignee: Thomson-CSF
    Inventors: Jean-Pierre Huignard, Cécile Joubert, Jean-Claude Lehureau, Brigitte Loiseaux
  • Patent number: 6236475
    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.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: May 22, 2001
    Assignee: Sony Corporation
    Inventors: Nobuhiro Kihara, Akira Shirakura
  • Patent number: 6236476
    Abstract: An apparatus for making a high quality reflection type holographic optical element (HOE) using a single input laser beam, including a reflective mirror, a holographic photoplate having a photo emulsion layer on a surface nearest the reflective mirror, a cassette for retaining the reflective mirror and the holographic photoplate, and a refractive index matching fluid containing a light absorbent dye for absorbing an input laser beam. The cassette is immersed in the fluid so that fluid is retained between the photo emulsion layer of the holographic photoplate and a reflective surface of the reflective mirror. Parasitic interference patterns are suppressed by heating the refractive index matching fluid with the input laser beam, which causes a shift of the phase of the parasitic beams with respect to the phase of the beams responsible for recording the HOE. If the photo emulsion layer of the holographic photoplate consists of a dichromated gelatin (DCG), then a photo sensitizer agent (e.g.
    Type: Grant
    Filed: April 10, 1998
    Date of Patent: May 22, 2001
    Assignee: Korea Institute of Science and Technology
    Inventors: Jung Young Son, Vadim V. Smirnov, Hyung Wook Jeon
  • Patent number: 6215546
    Abstract: The present invention discloses a method of optical correction for improving the pattern shrinkage caused by scattering of the light during photolithography processes, wherein the patterns on photomasks are corrected by providing aid patterns. Therefore, serifs or hammerheads are not necessary, and the costs can be decreased. According to the present invention, a chrome aid block is provided between the edges of the patterns. It is noted that the size of the chrome aid block is between ⅓ to ½ the wavelength of light used during exposure. Therefore, the pattern shrinkage caused by scattering of the light during exposure can be reduced, and there is no additional block formed on the photoresist layer. In addition, the standing wave effect can be prevented; thus, the pattern transfer is more accurate.
    Type: Grant
    Filed: April 3, 2000
    Date of Patent: April 10, 2001
    Assignee: Nanya Technology Corporation
    Inventors: Ronfu Chu, Quentin Chen, Chungwei Hsu, Jengping Lin
  • Patent number: 6195185
    Abstract: An image recording apparatus is capable of reducing a vibration of a hologram recording medium so that a holographic stereogram which provides an excellent reproduced image can be prepared in a short time period. A vibration member 55 is provided on the light path of reference light L4, and a hologram recording medium 10 is intermittently fed with the medium 10 kept in contact with an end portion 55a of the member 55. The reference light L4 passes through a slit 56 of the vibration restriction member 55 and is irradiated onto the hologram recording medium 10 through an opening portion 57 opened at the end side 55a.
    Type: Grant
    Filed: September 1, 1999
    Date of Patent: February 27, 2001
    Assignee: Sony Corporation
    Inventors: Akira Shirakura, Nobuhiro Kihara, Hirotsugu Suzuki
  • Patent number: 6185018
    Abstract: A holographic stereogram printing apparatus that is able to formulae a holographic stereogram superior in light utilization efficiency and in picture uniformity. The holographic stereogram printing apparatus causes the laser light from a laser light source 31 to fall on a picture display device 41 to illuminate the light transmitted through the display device 41 as object light on a holographic recording medium 30. The holographic stereogram printing apparatus also causes part of the laser light prior to being transmitted through the display device 41 to be illuminated as reference light on the holographic recording medium 30 to form the element holograms sequentially on the holographic recording medium 30. In the holographic stereogram printing apparatus, a light integrator 63 for uniforming the intensity of light incident on the display device 41 is provided on the optical path of the laser light proceeding towards the display device 41.
    Type: Grant
    Filed: December 28, 1998
    Date of Patent: February 6, 2001
    Assignee: Sony Corporation
    Inventor: Nobuhiro Kihara
  • Patent number: 6185019
    Abstract: A holographic lithography tool (110) for generating a light interference pattern used to expose a photosensitive medium (119) employs a refracting prism (121) in the optical path between divergent illuminating beams (127a, 127b). The prism is optically coupled to the photosensitive medium via an index matching fluid (123). By increasing the incident beam angle and the index of refraction, the prism reduces the size of features recorded in the photosensitive material. The divergent illuminating beams are generated by a beam delivery system which preferably employs easily adjustable fiber optic cables (176, 184). Use of the prism coupling technique facilitates use of fiber-optic-compatible wavelengths in the blue region of the spectrum in a variety of applications, such a distributed feedback grating fabrication.
    Type: Grant
    Filed: May 14, 1999
    Date of Patent: February 6, 2001
    Assignee: Optical Switch Corporation
    Inventors: Douglas S. Hobbs, Bruce D. MacLeod, Adam F. Kelsey