Patents by Inventor Keiji Kataoka
Keiji Kataoka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5444567Abstract: A light control device including an electro-optical material, a light refraction device mounted on the surface of the electro-optical material and electrodes provided on respective front and back major surfaces of the electro-optical material. A waveguide layer may be formed on the electro-optical material, with one electrode formed on an upper major surface of the waveguide layer and another electrode on the lower major surface of the electro-optical material. A prism or a diffraction grating may be used as the light refraction device. The light control device is particularly useful in laser printers and optical disk devices.Type: GrantFiled: November 9, 1992Date of Patent: August 22, 1995Assignee: Hitachi Koki Co., Ltd.Inventor: Keiji Kataoka
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Patent number: 5402409Abstract: A method of optically recording original information supplied from information generating device on an optical recording material in an optical recording apparatus, comprising the steps of: generating, from the original information, interpolating information which is to be interpolated in a sub-scanning direction of the optical recording material; and optically recording the interpolating information in the sub-scanning direction by a plurality of laser beams.Type: GrantFiled: July 19, 1993Date of Patent: March 28, 1995Assignee: Hitachi Koki Co., Ltd.Inventors: Keiji Kataoka, Susumu Saito, Yasuyuki Tsuji, Shuuho Yokokawa, Kunitomo Takahashi, Tsukasa Ogawa, Youji Hirose, Hiroshi Ueno
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Patent number: 5325172Abstract: An optical system is provided with a laser device for emitting a multiplet laser beam with two types of frequencies F1, F2, and a sample rotator on which a reference sample and a test sample containing substances are set for rotating both the test sample and the reference sample to separate the substances contained in the test sample. The test sample and the reference sample are irradiated with the multiplet laser beam one after another to shift the phase of the laser beam. The optical system is further provided with a polarizer for polarizing the multiplet laser beams transmitting through the test sample and the reference sample to produce both a test sample signal with a frequency .DELTA.F=F1-F2 and a reference sample signal with the frequency .DELTA.F, and a signal analyzer for analyzing a phase difference between the sample signals to determine an index of refraction of the test sample. Therefore, the substances containing in the test sample are specified.Type: GrantFiled: January 13, 1993Date of Patent: June 28, 1994Assignee: Hitachi Koki Company LimitedInventors: Keiji Kataoka, Sadamoto Tachihara, Masakuni Koreeda
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Patent number: 5296995Abstract: The present invention uses a magnetic recording medium equipped with those magnetically readable recording servo pits which are preformed on a magnetic recording medium and have different magnetic characteristics from those of a recording magnetic film, detects magnetically a tracking signal or preformat signals such as sync signals, address signals, and the like, from the magnetic flux distribution (leakage magnetic field) occurring at edges of each of the servo pits using a magnetic head, makes servo control of the position of the magnetic head by the detected tracking signal and records or reads magnetically the data along the center of a track.Type: GrantFiled: January 4, 1993Date of Patent: March 22, 1994Assignee: Hitachi, Ltd.Inventors: Seiji Yonezawa, Keiji Kataoka, Hajime Fukke, Tsuneo Terasawa, Keizo Kato, Harukazu Miyamoto, Klaus Kinstatter, Masaru Ito, Norio Ohta
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Patent number: 5218377Abstract: In a laser printing device in which a laser beam is deflected in a scanning mode while its intensity is being modulated, to record a halftone image on an optical recording material, the scanning laser beam is oscillated in a direction substantially perpendicular to the scanning direction within one pitch of the scanning line formed on the optical recording material, and the oscillation of the scanning laser beam is changed in amplitude by a signal provided by a computer, whereby a halftone image is recorded with high accuracy.Type: GrantFiled: April 23, 1991Date of Patent: June 8, 1993Assignee: Hitachi Koki Co., Ltd.Inventors: Keiji Kataoka, Susumu Saito, Takeshi Mochizuki
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Patent number: 5170383Abstract: A magneto-optical data recording system includes magnetic field pulse applying apparatus for applying to a magneto-optic recording medium a magnetic field pulse of a polarity corresponding to code data to be recorded, and a heating apparatus for heating the recording medium in a pulsating manner at a predetermined frequency synchronous with the code data to be recorded. During recording, the magnetic field pulse applying apparatus applies a magnetic field pulse of a polarity corresponding to code data along a track of the recording medium and the heating apparatus continuously heats the recording medium in a pulsating manner at a predetermined frequency synchronous with the code data to thereby directly overwrite the code data. The magnetic field pulse applying apparatus includes a magnetic coil driven by code data from a source of code data (data generator).Type: GrantFiled: May 18, 1989Date of Patent: December 8, 1992Assignee: Hitachi, Ltd.Inventors: Seiji Yonezawa, Norio Ohta, Toshio Niihara, Keiji Kataoka, Masahiko Takahashi, Harukazu Miyamoto, Hirofumi Sukeda, Toshiaki Tsuyoshi
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Patent number: 5142140Abstract: An apparatus for counting and analyzing sample particles such as cells suspended in a fluid by applying an irradiation beam such as a laser beam to the sample particles in a flow cell. The apparatus includes a device for supplying a flow cell with suspension of sample particles, an optical system for applying a laser beam to the sample particles in the above-mentioned suspension, a light gathering device for forming image of the above-mentioned sample particles, a light sensing device for sensing light from the above-mentioned formed image of the sample particles, and an analysis for analyzing the above-metnioned sample particles on the basis of the above-mentioned sensed light. The optical system may include a polarizing beam splitter and such convergent lenses having mutually different magnifications relative to two directions perpendicular to the optical axis of the laser beam.Type: GrantFiled: October 25, 1990Date of Patent: August 25, 1992Assignee: Hitachi, Ltd.Inventors: Isao Yamazaki, Hiroshi Ohki, Toshio Kaneko, Keiji Kataoka
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Patent number: 5134426Abstract: An optical device for illuminating an object with a rectangular pattern having a uniform light intensity distribution includes n (n.gtoreq.1) polarization separating elements which a laser beam emitted from a laser source enters and each of which separates the laser beam into two beams in two directions. The angle of separation by the polarization separating element is set to be 2.sup.(n-1) times of the smallest one of the separation angles of the polarization separating elements used. At least one quarter-wave or half-wave plate is combined with the polarization separating elements. An imaging lens is provided for forming 2.sup.n beam spots on the object such as an optical laser disk plate.Type: GrantFiled: March 29, 1990Date of Patent: July 28, 1992Assignee: Hitachi, Ltd.Inventors: Keiji Kataoka, Seiji Yonezawa, Toshio Kaneko
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Patent number: 5005969Abstract: Disclosed is an optical projection apparatus with the function of controlling laser coherency which comprises a laser source, a splitting device for splitting light emitted from the laser source into a plural incoherent split light beams having light intensity equal to each other, an illumination optical system for focusing each of the split light beams, and a projection optical system for projecting an image of a pattern of a mask illuminated with the split light beams from the illumination optical system onto a sample.Type: GrantFiled: March 29, 1989Date of Patent: April 9, 1991Assignee: Hitachi, Ltd.Inventor: Keiji Kataoka
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Patent number: 4929044Abstract: An optical pickup comprises at least a semiconductor laser, a waveguide optically coupled with the semiconductor laser for propagating therein a light from the semiconductor to guide it to a recording medium and a light deflector element provided on the waveguide for deflecting the light propagated in the waveguide by means of a surface acoustic wave. A multi-mode oscillation laser capable of stably operating in longitudinal modes the number of which is not larger than 5 is used as the semiconductor laser. The semiconductor laser is disposed in proximity to the waveguide at a distance not larger than 1 .mu.m, thereby inputting the light from the semiconductor laser into the waveguide with a high efficiency. A frequency applied to the light deflector element may be changed upon change between a read-out state and a write-in state so that a light spot on the recording medium is held at a predetermined position (track or address).Type: GrantFiled: May 13, 1988Date of Patent: May 29, 1990Assignee: Hitachi, Ltd.Inventors: Akira Arimoto, Sachiko Ishikawa, Keiji Kataoka
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Patent number: 4857744Abstract: An optical projection printing apparatus which can irradiate a mask with light from a first light source to focus the mask pattern on a resist of a semiconductor wafer in a highly accurate alignment by a first optical system including a projection lens. A wafer mark formed on the wafer to have a grating pattern shape is arranged to have its grating pitch direction located in the sagittal plane of the first optical system. The wafer mark is irradiated with the light coming from a second light source having a wavelength different from that of the first light source. Of the reflected light from the wafer mark, only the .+-. 1st order diffraction light is extracted by a filter and partially superposed on the mask in a transversely misaligned state so that the reflected light from the wafer mark may be focused by a second optical system. The aforementioned filter is disposed in the Fourier plane of the second optical system.Type: GrantFiled: July 27, 1988Date of Patent: August 15, 1989Assignee: Hitachi, Ltd.Inventors: Keiji Kataoka, Toshiei Kurosaki, Seiji Yonezawa, Soichi Katagiri
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Patent number: 4840447Abstract: A light modulating device array formed in a surface of a crystal plate with an electrooptic effect includes an optical input coupling waveguide portion receiving a laser beam from a laser source, a tapered waveguide array portion for dividing a light beam from the optical input coupling waveguide portion into a plurality of parts, and a plurality of light modulating parts juxtaposed in a predetermined direction and receiving light beams from the tapered waveguide array portion. Each of the light modulating parts includes an input waveguide portion and a pair of modulating waveguide portions formed by bifurcating the input waveguide portion, so as to form a Mach-Zehnder type waveguide structure. Further, each light modulating part includes electrodes for controlling the modulating waveguide portions, to vary the intensity of light outputted from the light modulating part, in accordance with a voltage applied to each electrode.Type: GrantFiled: September 10, 1987Date of Patent: June 20, 1989Assignee: Hitachi, Ltd.Inventor: Keiji Kataoka
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Patent number: 4802153Abstract: Accessing method and an apparatus therefor in an optical disc apparatus having an acousto-optic light deflector for deflecting a light spot to a different address or different track on an optical disc are disclosed. An auto-focus signal is held at a constant level for a predetermined period when the acousto-optic light deflector deflects the light spot. Thus, an affect caused by coexistence of a plurality of acoustic frequencies in the acoustic-optic device is eliminated and fast light accessing is attained.Type: GrantFiled: March 21, 1986Date of Patent: January 31, 1989Assignee: Hitachi, Ltd.Inventors: Keiji Kataoka, Takeshi Maeda, Yoshito Tsunoda
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Patent number: 4779943Abstract: An optical system and a optical information processing equipment utilizing the same are disclosed. The optical system comprises a laser diode and a hologram lens has an interference fringe prepared by the interference of a beam having substantially the same intensity distribution and/or phase characteristic as that of a laser beam emitted from the laser diode with a beam having a desired characteristic. The laser beam from the laser diode is irradiated on the hologram lens so that its characteristic is converted into the desired characteristic.Type: GrantFiled: February 8, 1984Date of Patent: October 25, 1988Assignees: Hitachi, Ltd., Hitachi Koki Co., Ltd.Inventors: Kimio Tatsuno, Susumu Saito, Akira Arimoto, Keiji Kataoka
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Patent number: 4759628Abstract: In an interferometry wherein a light beam from a light source is divided in two, one of which is used as a reference beam and the other beam is used as an inspecting beam, and the two beams are projected again on an identical plane so as to form an interference pattern; a wavelength scanning type laser diode interferometry characterized in that a laser diode is employed as the light source, and that an injection current of the laser diode is modulated thereby to scan a wavelength of the laser diode and to change an intensity distribution of the interference pattern.Type: GrantFiled: February 5, 1986Date of Patent: July 26, 1988Assignee: Hitachi, Ltd.Inventors: Kimio Tatsuno, Yoshito Tsunoda, Masatoshi Ohtake, Keiji Kataoka, Seiji Yonezawa
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Patent number: 4750815Abstract: A method and apparatus for generating optical information are disclosed. A plurality of electrode wires are arranged on an electro-optical crystal, a light beam passing through the electro-optical crystal is spatially phase-modulated by an electro-optical effect due to a voltage applied to the electrode wires, a portion of light distribution spread by diffraction of the phase-modulated light beam is blocked by an optical system having an aperture or a slit arranged on a focal plane of the optical system, and the light passed through the aperture is focused to generate optical information composed of a minimum unit equal to a multiple of a minimum electrode-to-electrode distance.Type: GrantFiled: November 15, 1985Date of Patent: June 14, 1988Assignee: Hitachi, Ltd.Inventors: Keiji Kataoka, Akira Arimoto
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Patent number: 4689479Abstract: This invention is characterized in that a modified polarization prism or a modified half prism is used therein. Since photodetectors serving at the same time for light signal detection, for automatic focussing and for tracking are disposed at opposite sides of the optical source of a semiconductor laser, a single axis optical system can be realized and it is possible to reduce the optical head in size.Type: GrantFiled: December 14, 1984Date of Patent: August 25, 1987Assignee: Hitachi, Ltd.Inventors: Kimio Tatsuno, Keiji Kataoka
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Patent number: 4688880Abstract: A hologram lens of the present invention has a spherical hologram surface, the center of said spherical surface being in agreement with a focal point of the lens, and the radius of said spherical surface being in agreement with a focal distance of the lens. Therefore, the hologram lens of the invention produces little aberration.Type: GrantFiled: July 20, 1984Date of Patent: August 25, 1987Assignee: Hitachi, Ltd.Inventors: Kimio Tatsuno, Keiji Kataoka, Seiji Yonezawa
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Patent number: 4656618Abstract: In an optical information recording and reproducing apparatus having a laser light source and an optical system so that a beam from the laser light source is irradiated through the optical system on an information recording medium to record and reproduce information, an accousto-optic modulator is disposed in the optical system for receiving the beam from the laser light source, and a modulation unit is provided which comprises an oscillator for generating a plurality of signals at different frequencies, a modulator for modulating the outputs of the oscillator and an adder for adding together the outputs of the modulator.Type: GrantFiled: August 9, 1984Date of Patent: April 7, 1987Assignee: Hitachi, Ltd.Inventors: Toshimitsu Kaku, Keiji Kataoka, Yoshito Tsunoda, Kazuo Shigematsu
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Patent number: 4644160Abstract: Herein disclosed is a system using a plurality of laser beams, in which the positions of the respective laser beams are detected as the differences between the outputs of detectors of an optical detector arrangement and controlled by the difference signals so that they may be held mutually precisely. This system finds its suitable application to an optical disk recording system or a laser beam printer.Type: GrantFiled: December 11, 1984Date of Patent: February 17, 1987Assignees: Hitachi, Ltd., Hitachi Koki Co., Ltd.Inventors: Akira Arimoto, Susumu Saito, Kimio Tatsuno, Keiji Kataoka