Flat Rotating Disk Patents (Class 359/18)
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Patent number: 5859715Abstract: A scanner (40) is disclosed which includes a source of coherent light (12), a radial holographic deflector (16), a F.theta. lens (62), which images a scanned spot onto an image plane (18). The F.theta. lens (62) is comprised of a decentered aspheric mirror (64) and a diffractive--refractive toroidal lens (66). The apparatus is relatively insensitive to variations in the wavelength of the source of coherent light.Type: GrantFiled: July 19, 1996Date of Patent: January 12, 1999Assignee: Eastman Kodak CompanyInventors: Mark M. Meyers, Badhri Narayan
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Patent number: 5805315Abstract: A holographic scanner for scanning a surface with a light beam is provided. The holographic scanner includes a light source for emitting light used as the light beam, a front hologram for diffracting the light emitted from the light source to produce a first diffracted beam, a rotary hologram disk having a disk plane and rotatable around an axis thereof vertical to the disk plane, the rotary hologram disk including a plurality of scanning holograms arranged on the disk plane in a circumferential direction, the scanning holograms diffracting the first diffracted beam to produce a second diffracted beam, and a rear hologram for diffracting the second diffracted beam to produce a third diffracted beam, the third diffracted beam being used as the light beam for illuminating the scanning plane.Type: GrantFiled: May 15, 1997Date of Patent: September 8, 1998Assignee: Sharp Kabushiki KaishaInventors: Tadashi Iwamatsu, Tetsuro Toyoshima
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Patent number: 5798851Abstract: An optical scanner including a light source which is turned ON and OFF in accordance with drawing data. A hologram deflector, made of a rotatable planar hologram disc, provided with a plurality of hologram facets through which light emitted from the light source passes, is rotated to scan an image surface with light emitted from the light source. An optical detector detects light passing in a scanning direction through at least a first reference point, for the commencement of the scanning, and a second reference point, for the completion of the scanning. A scanning time detector detects a scanning time period in which the light deflected by each hologram facet of the hologram disc, passes the first reference point and reaches the second reference point. Finally, a frequency varying device varies the frequency of the light source for each hologram facet in accordance with a unique scanning time period directed by the scanning time detector for each hologram facet.Type: GrantFiled: April 22, 1997Date of Patent: August 25, 1998Assignee: Asahi Kogaku Kogyo Kabushiki KaishaInventors: Satoru Tachihara, Ryota Ogawa, Katsuhiro Yoshino
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Patent number: 5764391Abstract: A holographic display including a planar transparent light pipe (11) configured for rotation about a light pipe rotation axis that is orthogonal to the planar extent of the transparent light pipe and passes through a rotational center of the light, a multiple image hologram structure (13) having a plurality of holographic images attached to one side of the planar transparent light pipe, wherein the images are at different azimuthal angular positions on the light pipe about the light pipe rotation center, and a light source (17) for illuminating an input surface of the transparent light pipe such that an injected beam propagates within the light pipe to provide reconstruction illumination for a portion of the multiple image hologram structure.Type: GrantFiled: December 18, 1996Date of Patent: June 9, 1998Assignee: Raytheon CompanyInventor: Ronald T. Smith
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Patent number: 5691831Abstract: A laser source and a converging lens are provided so that a laser beam emitted from the converging lens travels substantially parallel to the surface of a hologram disc. A incidence mirror is provided for causing the laser beam emitted from the lens to fall incident on the hologram disc at an angle of incidence of about 45 degrees. By merely moving or rotating the incidence mirror, the position of and the angle of incidence of laser beam to the hologram disc can be easily adjusted.Type: GrantFiled: June 28, 1995Date of Patent: November 25, 1997Assignee: Brother Kogyo Kabushiki KaishaInventor: Kazunari Taki
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Patent number: 5680253Abstract: A high-resolution light-beam scanning apparatus utilizing only mass-producible holograms instead of utilizing auxiliary optical systems, and capable of compensating for disadvantages.Type: GrantFiled: November 25, 1992Date of Patent: October 21, 1997Assignee: Fujitsu LimitedInventors: Shinya Hasegawa, Shigeo Kayashima, Satoshi Maeda, Shigetake Iwata, Fumio Yamagishi, Masato Nakashima, Hirokazu Aritake, Mamoru Hokari
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Patent number: 5680232Abstract: A holographic scanner for scanning a surface with a light beam is provided. The holographic scanner includes a light source for emitting light used as the light beam, a front hologram for diffracting the light emitted from the light source to produce a first diffracted beam, a rotary hologram disk having a disk plane and rotatable around an axis thereof vertical to the disk plane, the rotary hologram disk including a plurality of scanning holograms arranged on the disk plane in a circumferential direction, the scanning holograms diffracting the first diffracted beam to produce a second diffracted beam, and a rear hologram for diffracting the second diffracted beam to produce a third diffracted beam, the third diffracted beam being used as the light beam for illuminating the scanning plane.Type: GrantFiled: May 12, 1995Date of Patent: October 21, 1997Assignee: Sharp Kabushiki KaishaInventors: Tadashi Iwamatsu, Tetsuro Toyoshima
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Patent number: 5646774Abstract: This invention is an improvement of a mode-locked laser stabilizing method and apparatus used with a mode-locked laser apparatus which comprises an optical cavity which consists of an optical modulator which modulates the loss or the phase of light at a fixed frequency, an optical delay line to electrically change the optical path length of the cavity, and an optical amplifier which amplifies a modulated optical pulses. In this method, at least one of the relaxation oscillation frequency components and the harmonic components in the output optical pulses of the mode-locked laser are extracted, and a process of controlling the optical delay line by using the extracted frequency component as an error signal for feedback control and to suppress the error signal below a fixed value.Type: GrantFiled: January 16, 1996Date of Patent: July 8, 1997Assignee: Nippon Telegraph and Telephone CorporationInventors: Hidehiko Takara, Satoki Kawanishi, Masatoshi Saruwatari
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Patent number: 5621548Abstract: A method for fabricating a holeless hologon disk includes the steps of relatively positioning a disk assembly and a drive shaft assembly in closely spaced relation with the planar surface of the disk normal to the drive shaft's rotational axis. Adhesive is applied between the assemblies and allowed to fix while the relative assembly positions are maintained. In one construction fabricated by such method, the disk assembly comprises a flanged coupling attached to a planar glass disk with compliant adhesive.Type: GrantFiled: March 31, 1995Date of Patent: April 15, 1997Assignee: Eastman Kodak CompanyInventors: John R. Debesis, Robert C. Bryant, James S. Newkirk, Richard A. Colleluori, Timothy A. Peter
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Patent number: 5619350Abstract: An optical scanning device including a semiconductor laser and a scanning optical system which transmits a laser beam emitted from the semiconductor laser and scans the laser beam on a photosensitive drum. The scanning optical system includes at least one hologram having relief on at least one surface with the ratio h/P of the depth h and the minimum pitch P of the relief being set to about 1 or less in an area of the hologram surface the laser beam irradiates.Type: GrantFiled: February 21, 1995Date of Patent: April 8, 1997Assignee: Brother Kogyo Kabushiki KaishaInventor: Kazunari Taki
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Patent number: 5555130Abstract: A holographic grating element is provided which enables tracing different scan lines. The element is divided into a plurality of sectors. A first grating pattern is provided which diffracts a beam in one direction, and a second grating pattern is next to the first and diffracts the scan beam in the reverse direction. Sectors can be produced with different sector sizes to enable scanning at different rates in the reverse direction, or in successive scans in the same direction. Angle relationships are described to produce diffraction patterns for a desired relationship between disc rotation and the angle of the scan line.Type: GrantFiled: June 6, 1995Date of Patent: September 10, 1996Assignee: Symbol Technologies, Inc.Inventors: Emanuel Marom, Joseph Katz, Edward Barkan
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Patent number: 5550655Abstract: A laser beam passes through two holograms or through a hologram twice to reduce the ratio .lambda./d so that P-polarized light, as well as S-polarized light, can be diffracted with high diffraction efficiency and uses a hologram or holograms formed on a base plate and facilitates the separation of a stamper from the base plate in producing replicas of the hologram. A laser beam (5) passes through two holograms formed on a transparent base plate or through a hologram formed on a transparent base plate twice. The ratio .lambda./d, where .lambda. is the wavelength of the laser beam and d is the grating constant of the hologram, is in the range of 0.4 to 1.1.Type: GrantFiled: April 22, 1994Date of Patent: August 27, 1996Assignee: Fujitsu LimitedInventors: Shigeo Kayashima, Shinya Hasegawa, Satoshi Maeda, Hirokazu Aritake
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Patent number: 5506703Abstract: A three-dimensional image display device which comprises a holographic plate having a plurality of holograms divided in correspondence with rotational angles, the holographic plate being exposed so that when light is irradiated, each of the holograms forms a point image at a different position in a depth direction of the holographic plate; a drive unit for rotating the holographic plate; a light irradiating unit including a plurality of light sources arranged substantially in a straight line so that the light sources are kept at substantially equal distances from the holographic plate, for irradiating the holographic plate with light from the light sources; and a controller for controlling the drive unit and lighting operations of the plurality of light sources of the light irradiating unit in accordance with a signal indicative of a three-dimensional image to be displayed so as to control lighting of a plurality of point images formed in a three-dimensional space, whereby a three-dimensional image can be obtType: GrantFiled: February 16, 1994Date of Patent: April 9, 1996Assignee: Kabushiki Kaisha Komatsu SeisakushoInventors: Toru Suzuki, Hideyuki Wakai, Manabu Ando, Kiyokazu Mizoguchi, Keiji Terada, Masato Moriya, Koji Shio
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Patent number: 5504595Abstract: A holographic grating element is provided which enables tracing different scan lines. The element is divided into a plurality of sectors. A first grating pattern is provided which diffracts a beam in one direction, and a second grating pattern is next to the first and diffracts the scan beam in the reverse direction. Sectors can be produced with different sector sizes to enable scanning at different rates in the reverse direction, or in successive scans in the same direction. Angle relationships are described to produce diffraction patterns for a desired relationship between disc rotation and the angle of the scan line.Type: GrantFiled: April 8, 1994Date of Patent: April 2, 1996Assignee: Symbol Technologies, Inc.Inventors: Emanuel Marom, Joseph Katz, Edward Barkan
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Patent number: 5471326Abstract: A holographic optical element (HOE) includes a substrate structure having rotational symmetry with respect to a rotational axis for rotatively supporting at least two holograms. A first hologram on the substrate structure in the path of a normally incident beam diffracts the beam by a first acute angle and in a first radial direction from the rotational axis to a first redirected path. A second hologram on the substrate structure in the first redirected path diffracts the beam by a different second acute angle and in an opposite second radial direction from the rotational axis to a second redirected path. As a result, the two holograms may be used to achieve a second redirected path at an angle to the rotational axis that has a size which is the difference between the size of the first angle and the size of the second angle.Type: GrantFiled: April 30, 1993Date of Patent: November 28, 1995Assignee: Northrop Grumman CorporationInventors: James T. Hall, Arthur B. O'Connor, Susan M. Raffensperger, Seymour Levine
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Patent number: 5457550Abstract: An optical scanner unit for scanning a document includes a laser unit for emitting a laser beam used for scanning the document, an optical system in which the laser beam emitted from the laser unit travels to the document and a reflection light beam obtained by reflection of the laser beam on the document can turn back through the optical system, the optical system having a scanning device for moving the laser beam which passes through the optical system so that a two dimensional scanning of the document is carried out by the light beam, and an optical sensor for detecting the reflection light beam turning back through the optical system, wherein an image formed on the document is read based on results obtained by the optical sensor.Type: GrantFiled: February 26, 1992Date of Patent: October 10, 1995Assignee: Ricoh Company, Ltd.Inventors: Nobuyuki Baba, Toshiyuki Inokuchi
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Patent number: 5448403Abstract: An optical scanning system uses a stationary binary diffractive optical element and a rotating binary diffractive element to focus and scan a beam along the scan line.Type: GrantFiled: April 8, 1994Date of Patent: September 5, 1995Assignee: Xerox CorporationInventor: Ellis D. Harris
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Patent number: 5430560Abstract: A three-dimensional image display device which comprises a light source; a hologram divided into a plurality of divided areas and exposed so that point images are formed at different positions in a three-dimensional space in the respective divided areas when the light from the light source is irradiated; a hologram driver unit for driving the hologram such that light from the light source is selectively entered into one of the plurality of divided areas and; a control unit for controlling the lighting up of the point images formed in the three-dimensional space in correspondence to a three-dimensional image signal by controlling the hologram and the light source in accordance with the three-dimensional image signal to be displayed, whereby a three-dimensional image is obtained by the hologram with the simple-configured device.Type: GrantFiled: December 13, 1993Date of Patent: July 4, 1995Assignee: Kabushiki Kaisha Komatsu SeisakushoInventors: Hideyuki Wakai, Toru Suzuki, Keiji Terada, Masato Moriya, Manabu Ando
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Patent number: 5418632Abstract: A three dimensional display having a rotating screen, preferably helical in shape, a light source providing a beam of light and a holographic pattern deflecting the beam of light to predetermined points on the screen. The light is modulated, preferably by the holographic pattern. The holographic pattern rotates with the same angular velocity as the screen. The holographic pattern comprises a plurality of concentric circles, each of the circles comprising a plurality of cells, each of the cells representing a point on the screen.Type: GrantFiled: January 21, 1994Date of Patent: May 23, 1995Assignee: Texas Instruments IncorporatedInventor: Douglas W. Anderson
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Patent number: 5379134Abstract: A holographic disk mounting system and method is disclosed utilizing a compressible O-ring which eliminates the clearance between the spin motor shaft and the holographic disk. The holographic disk has an axial bore with a diameter slightly greater than the diameter of the spin motor shaft. A compressible O-ring is placed around the spin motor shaft and then the holographic disk is mounted thereon with the O-ring and O-ring surrounded portion of the spin motor shaft positioned within the axial bore of the holographic disk. The O-ring is axially compressed to radially expand the O-ring thereby eliminating the clearance between the spin motor shaft and the bore of the holographic disk. Thereafter, the holographic disk is secured to the motor shaft with the O-ring remaining in a compressed state.Type: GrantFiled: August 5, 1993Date of Patent: January 3, 1995Assignee: Miles Inc.Inventor: Daniel L. Manitakos
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Patent number: 5335108Abstract: An optical synchronization system uses a rotating disc with alternating binary diffractive optical elements for a synchronization signal for a pixel clock.Type: GrantFiled: November 22, 1993Date of Patent: August 2, 1994Assignee: Xerox CorporationInventor: Ellis D. Harris
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Patent number: 5309272Abstract: An optical scanning system uses a double pass of a light beam through two rotating binary diffractive optical elements on a disc to focus a scan beam at a scan line and to scan the beam along the scan line which doubles the scan angle of the beam.Type: GrantFiled: December 11, 1992Date of Patent: May 3, 1994Assignee: Xerox CorporationInventor: Ellis D. Harris
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Patent number: 5296958Abstract: Laser beam scanning system combines multiple light beams, each of differing wavelengths, to achieve a multiple wavelength scan exposure of a medium, or to increase throughput by writing plural lines simultaneously, or to provide one or more scanning beams of selected wavelength. A polarizing beam splitting prism of the Thompson type is employed as a multiple input beam combiner. The two input laser beam components can be made selectively coincident or closely parallel to form an output beam which is then redirected in a scanning motion and focused to an exposure plane.Type: GrantFiled: May 29, 1992Date of Patent: March 22, 1994Assignee: Eastman Kodak CompanyInventors: James E. Roddy, Badhri Narayan
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Patent number: 5295004Abstract: An optical beam scanning apparatus includes one rotatable hologram which is rotatable about an axis, and at least two laser beam sources which emit laser beams. The rotatable hologram is provided with at least two hologram areas whose number corresponds to the number of the laser beam sources, so that the laser beams emitted from the respective laser beam sources are made incident upon the respective hologram areas. Each of the hologram areas is provided with a plurality of hologram facets which are concentrically arranged with respect to the axis of rotation of the rotatable hologram to emit laser beams of the same F number. The hologram areas having different numbers of hologram facets having different F numbers.Type: GrantFiled: November 6, 1992Date of Patent: March 15, 1994Assignee: Fujitsu LimitedInventors: Shinya Hasegawa, Fumio Yamagishi, Youji Houki, Shigetake Iwata, Shigeo Kayashima, Satoshi Maeda
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Patent number: 5291319Abstract: An optical synchronization system uses a stationary binary diffractive optical element and a rotating disc with alternating scattering binary diffractive optical elements and transmissive elements to create a moire pattern for a synchronization signal for a pixel clock.Type: GrantFiled: December 11, 1992Date of Patent: March 1, 1994Assignee: Xerox CorporationInventor: Ellis D. Harris
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Patent number: 5258862Abstract: An optical synchronization system uses a stationary binary diffractive optical element and a rotating disc with alternating binary diffractive optical elements and blocking elements to create a moire pattern of a synchronization signal for a pixel clock.Type: GrantFiled: December 10, 1992Date of Patent: November 2, 1993Assignee: Xerox CorporationInventor: Ellis D. Harris
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Patent number: 5255108Abstract: By modifying the exposure sequence of the facets in a hologon during manufacture, it is intended to maximize the spatial frequency of the error especially in hologons having large numbers of facets so that the error frequency is multiplied by a large factor, thereby greatly reducing the eye's ability to detect banding problems. This method also minimizes the adjacent facet error as far as is practical.Type: GrantFiled: April 27, 1992Date of Patent: October 19, 1993Assignee: Eastman Kodak CompanyInventors: Badhri Narayan, James E. Roddy
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Patent number: 5255065Abstract: An optical scanning device utilizing a source of optical energy such as laser light backscattered from the earth's atmosphere or transmitted outward as in a lidar, a rotating holographic optical element having an axis of rotation perpendicular to the plane of its substrate, and having a stationary focus which may or may not be located on its axis of rotation, with the holographic optical element diffracting the source of optical energy at an angle to its rotation axis enabling a conical scanning area and a motor for supporting and rotating the rotating holographic optical element.Type: GrantFiled: March 10, 1992Date of Patent: October 19, 1993Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventor: Geary Schwemmer
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Patent number: 5253087Abstract: A holographic laser beam scanning apparatus capable of removing astigmatism created by a hologram disc of the apparatus due to discordance of wave fronts of the laser beams, thereby allowing precise scanning to be effected. The apparatus includes a focusing lens for focusing a laser beam generated by a laser generator, and a hologram for converting the focused beam into a parallel beam, both the lens and hologram being disposed between the laser generator for generating the laser beam and the hologram disc for irradiating the parallel beam as a diffracted beam.Type: GrantFiled: December 13, 1991Date of Patent: October 12, 1993Assignee: Gold Star Co., Ltd.Inventor: Keun Y. Yang
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Patent number: 5253088Abstract: By modifying the exposure sequence of the facets during manufacture of a hologon image writer the visibility of cross scan errors are minimized, thereby reducing exposure error and visible banding. With hologons having a number of facets "n" the general form of the exposure sequence is 1, n, 2, n-1, 3, n-2 . . . .Type: GrantFiled: April 27, 1992Date of Patent: October 12, 1993Assignee: Eastman Kodak CompanyInventors: Badhri Narayan, James E. Roddy
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Patent number: 5245442Abstract: A multi-functional laser printer capable of executing both the printing operation and the manuscript readout operation with one unit. The laser printer comprises a printing unit for splitting a laser beam generated from a laser into a picture forming beam and a manuscript reading-out beam by a beam splitter, and a manuscript readout unit for reading out the content of the manuscript by scanning the manuscript reading-out beam on the manuscript. The printing unit and the manuscript readout unit commony have a double-structured hologram disk for diffracting and scanning the splitted beams. The double-structured hologram disk comprises picture forming holograms formed on the outer peripheral surface thereof and manuscript reading-out holograms formed on the interior thereof.Type: GrantFiled: November 15, 1990Date of Patent: September 14, 1993Assignee: Goldstar Co., Ltd.Inventor: Keun Y. Yang
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Patent number: 5237160Abstract: A bar code scanner includes a semiconductor laser device for emitting a light beam, a hologram disc on which a grating is formed, the hologram disc rotating around a predetermined axis, an incident optical system provided for perpendicularly projecting the light beam emitted from the light source onto the grating formed on the hologram member, a first optical system which projects the light beam passing through the grating formed on the hologram member onto the medium, and a second optical system for guiding the light beam reflected by the medium to a detector. The first optical system includes a plurality of mirrors arranged under the hologram disc so as to surround the axis of rotation of the disc so that each of the mirrors reflects light diffracted by the hologram disc and thereby forms a scanning line.Type: GrantFiled: December 15, 1992Date of Patent: August 17, 1993Assignee: Ricoh Company, Ltd.Inventor: Nobuyuki Baba
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Patent number: 5223957Abstract: An optical scanning device which includes a laser light source, an aspheric lens for converging a laser beam emitted from the laser light source, and a reflection type holographic disk for diffracting and scanning the laser beam passing through the aspheric lens.Type: GrantFiled: May 12, 1992Date of Patent: June 29, 1993Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Tatsuo Itoh, Shinichi Mizuguchi
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Patent number: 5212572Abstract: An optical data storage system having a highly integrated optical storage head that (1) integrates the read, write and servo paths, (2) comprises a monolithic laser-detector storage array that is integrated on a single chip an, wherein laser-detector alignment desirably is fixed at the time of fabrication, and (3) comprises a four-hologram optical element that directs light to an optical disk and divides the returning light into one track error and two focus error servo beams and two polarization component beams for data detection, and also provides a satellite beam of the incident laser beam for monitoring power of the laser beam.Type: GrantFiled: November 22, 1991Date of Patent: May 18, 1993Assignee: International Business Machines CorporationInventors: Matthias C. Krantz, LeRoy D. Dickson
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Patent number: 5189533Abstract: An optical information reading apparatus for optically reading information recorded on a recording medium with a laser light beam emitted from a light source. The apparatus comprises a hologram device for receiving at its center portion a laser light beam. The hologram diffracts the received light so as to produce a first diffracted light beam and is arranged to receive at its entire surface light to be reflected from the recording medium and to diffract the received light so as to produce a second diffracted light beam. This hologram device is arranged to be driven by a motor so as to move the first diffracted light beam for a scanning operation. Also included in the reading apparatus is a reflection assembly for reflecting the first diffracted light beam from the hologram device toward the recording medium and further for reflecting light reflected from the recording medium toward substantially the entire surface of the hologram device whereby the hologram device produces the second diffracted light beam.Type: GrantFiled: April 1, 1991Date of Patent: February 23, 1993Assignees: Nippondenso Co., Ltd., Nippon Soken, Inc.Inventors: Masahiro Taguchi, Atsushi Hashikawa, Katsunori Goto
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Patent number: 5182659Abstract: A system that provides a structure which makes use of a recording geometry in which no significant Seidel induced aberrations arise. The recording geometry results in a pattern recorded on a photosensitive surface, thereby creating the hologram on the scanning disc. Reconstruction of the recorded object may be made by exposing the scanning disc to substantially monochromatic light. The hologram on the scanning disc not only directs the reconstruction beam, but also focuses it. An optical element may be used during reconstruction to correct for bow and linearity, and also optimize flatness of the focal plane. Reconstruction also involves achromatization, or correction of beam placement because of mode hops or drift in laser frequency. The reconstruction comprises both pre-scan holograms and post-scan holograms. Recording of the post-scan hologram is achieved with a plurality of lenses which possess different collimating properties in the vertical and horizontal planes.Type: GrantFiled: February 20, 1991Date of Patent: January 26, 1993Assignee: Holographix, Inc.Inventors: Burton R. Clay, David M. Rowe
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Patent number: 5172252Abstract: A hologram scanner includes a reproducing light source for generating a collimated reproducing light beam, a hologram disk being adapted to rotate, and a hologram disposed on the hologram disk for deflecting the reproducing light beam by diffraction so as to scan an image surface by the deflected reproducing light beam during a rotation of the hologram disk. The hologram has interference fringes recorded by a mutual interference of an object light of divergent spherical wave and a reference light of divergent spherical wave. The object light is generated by an object light source positioned at a first position apart from a hologram recording plane of the hologram disk, on which the hologram is to be recorded, by a first distance. The reference light is generated by a reference light source positioned at a second position apart from the hologram recording plane by a second distance.Type: GrantFiled: December 21, 1990Date of Patent: December 15, 1992Assignee: Sharp Kabushiki KaishaInventors: Tetsuro Toyoshima, Tetsuyuki Ueda
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Patent number: 5162929Abstract: A three-color laser scanner using a holographically-generated plane linear grating disk (hologon). The disk includes peripherally-arranged facets having identical multiplexed diffraction gratings. Each multiplexed grating is formed from plural superimposed interference patterns accumulated by multiple exposures to light from a single monochromatic laser beam source. The multiplexed grating is optimized to diffract certain light wavelengths in a single, multichromatic (plural wavelength) input laser beam. The diffracted output beam comprises respective wavelength beam components that simultaneously scan in collinear fashion. Modulation of the plural wavelength components in the incident beam allows the output beam to scan expose a multicolor image at the image plane.Type: GrantFiled: July 5, 1991Date of Patent: November 10, 1992Assignee: Eastman Kodak CompanyInventors: James E. Roddy, Badhri Narayan, Robert H. Cuffney, Kevin J. Klees, Laurie L. Voci
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Patent number: 5157522Abstract: A calibration method and apparatus is disclosed that includes a power stabilized laser diode to generate a laser beam that is passed through the hologon scanner to be calibrated and a mechanism for measuring the power intensity of the laser beam at a plurality of positions at an exposure plane for each facet of the hologon scanner. The measured light levels are converted to correction factors that are stored in a corresponding programmable read only memory (PROM) as a function of facet number and scan position. The hologon scanner and its corresponding programmable PROM are then installed in a laser scanning apparatus. The laser scanning apparatus adjusts the output of its light source in accordance with the correction factors stored in the PROM in order to compensate for variations in the light transmission efficiency of the facets of the hologon scanner.Type: GrantFiled: April 1, 1991Date of Patent: October 20, 1992Assignee: Eastman Kodak CompanyInventor: William R. Markis
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Patent number: 5061025Abstract: In a laser scanner of the type having beam shaping means and a stationary diffraction grating for directing the shaped beam to a hologon scanning disc, the beam shaping means is combined with the stationary diffraction grating by providing a shaped stationary diffraction grating, thereby eliminating the need for other beam shaping means prior to the shaped diffraction grating, thereby simplifying construction of the apparatus.Type: GrantFiled: April 13, 1990Date of Patent: October 29, 1991Assignee: Eastman Kodak CompanyInventor: John R. Debesis
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Patent number: 5046794Abstract: A hologon scanning system which provides two sequential scans across an image plane per revolution of the hologon. The hologon is a disc having a single facet with a planar linear diffraction grating in a surface which is perpendicular to the axis of rotation of the disc and which is centered on the axis of rotation. An incident laser beam which preferably overfills the facet is diffracted and scanned by the rotation of the facet. The facet is preferably elliptical in shape with its major axis perpendicular to the facet grating lines. The diameter of the disc can be made only slightly larger than the profile of the incident beam on the disc so as to minimize inertia and enable the disc to be rotated at very high speeds without failure due to centrifugal force induced stress. Four sequential scans per revolution can be produced by using a pair of superimposed centered facets with their grating lines oriented orthogonally to each other.Type: GrantFiled: March 30, 1990Date of Patent: September 10, 1991Assignee: Holotek Ltd.Inventors: Joachim A. Ritter, Mehdi N. Araghi, Charles J. Kramer