Patents by Inventor Miyozo Maeda
Miyozo Maeda 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: 6804183Abstract: A storage apparatus has a function of controlling rotation of a recording medium which is divided into a plurality of zones in a radial direction thereof and employing a ZCAV system. The storage apparatus is provided with a setting part for setting a mode to one of a normal mode in which the recording medium is controlled to rotate at a first rotational speed, and a high-speed mode in which the recording medium is controlled to rotated at a plurality of second rotational speeds respectively corresponding to a plurality of areas to which the recording medium is divided in the radial direction thereof.Type: GrantFiled: March 7, 2001Date of Patent: October 12, 2004Assignee: Fujitsu LimitedInventors: Toru Ikeda, Shigenori Yanagi, Miyozo Maeda
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Publication number: 20020041548Abstract: A storage apparatus has a function of controlling rotation of a recording medium which is divided into a plurality of zones in a radial direction thereof and employing a ZCAV system. The storage apparatus is provided with a setting part for setting a mode to one of a normal mode in which the recording medium is controlled to rotate at a first rotational speed, and a high-speed mode in which the recording medium is controlled to rotated at a plurality of second rotational speeds respectively corresponding to a plurality of areas to which the recording medium is divided in the radial direction thereof.Type: ApplicationFiled: March 7, 2001Publication date: April 11, 2002Applicant: FUJITSU LIMITEDInventors: Toru Ikeda, Shigenori Yanagi, Miyozo maeda
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Patent number: 6030716Abstract: A magneto-optical recording medium adapted for reproduction of a high resolution signal without the necessity of a reproducing magnetic field. The magneto-optical recording medium comprises a transparent substrate and deposits of a reproducing layer, a switch layer and a recording layer formed on the transparent substrate successively. The reproducing layer is a perpendicular magnetization film at a room temperature but is turned to an in-plane magnetization film when heated beyond a predetermined temperature. Each of the switch layer and the recording layer is a perpendicular magnetization film. The respective Curie temperatures Tc1, Tc2 and Tc3 of the reproducing layer, the switch layer and the recording layer satisfy the relationship of Tc1>Tc3>Tc2.Type: GrantFiled: November 17, 1997Date of Patent: February 29, 2000Assignee: Fujitsu LimitedInventors: Haruhiko Izumi, Ken Tamanoi, Masaharu Moritsugu, Miyozo Maeda, Toshio Sugimoto, Koji Matsumoto, Motonobu Mihara
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Patent number: 5796712Abstract: An optical disk is made up of a disk-shaped substrate having a surface, a first track and a second track provided on the surface of the substrate, where the first and second tracks are two mutually adjacent concentric tracks or two mutually adjacent track turns of a single spiral track, the first track extends along a first center line and the second track extends along a second center line, and an identification signal recording part extending along a third center line and prerecorded with an identification signal including at least a sector number and a track number for identifying a position on the optical disk. The third center line is arranged between the first and second center lines, and the identification signal prerecorded in the identification signal recording part is common to the first and second tracks on both sides of the identification signal recording part.Type: GrantFiled: January 8, 1997Date of Patent: August 18, 1998Assignee: Fujitsu LimitedInventors: Mineo Moribe, Miyozo Maeda, Susumu Satoh, Kyoko Miyabe
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Patent number: 5768245Abstract: Marks are recorded on an optical disk which is rotated at a constant rotational speed by laser light which is converged on a substantially circular spot. The pulse width of a recording pulse is set at a sufficiently narrow value and the recording power of the laser light is maintained at a constant value. Marks (corresponding to "1") are recorded on the entire disk surface by the laser light with the same recording pulse width and with the same recording power. The recording pulse width is less than about 30% of the mark interval obtained when they are recorded on the optical disk at the highest density. The recording power is set at the value which produces the maximum reproduction amplitude when said marks are recorded on the optical disk at the highest density.Type: GrantFiled: October 28, 1994Date of Patent: June 16, 1998Assignee: Fujitsu LimitedInventors: Miyozo Maeda, Yoshiyuki Nanba, Takehiko Numata
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Patent number: 5691072Abstract: Disclosed is a magneto-optical recording medium adapted for reproduction of a high resolution signal without the necessity of a reproducing magnetic field, whereby the magneto-optical recording medium comprises a transparent substrate, a reproducing layer, a switch layer and a recording layer formed on the transparent substrate successively. The reproducing layer is a perpendicular magnetization film at a room temperature but is turned to an in-plane magnetization film when heated beyond a predetermined temperature. Each of the switch layer and the recording layer is a perpendicular magnetization film. The respective Curie temperatures Tc1, Tc2 and Tc3 of the reproducing layer, the switch layer and the recording layer satisfy the relationship of Tc1>Tc3>Tc2.Type: GrantFiled: January 31, 1995Date of Patent: November 25, 1997Assignee: Fujitsu LimitedInventors: Haruhiko Izumi, Ken Tamanoi, Masaharu Moritsugu, Miyozo Maeda, Toshio Sugimoto, Koji Matsumoto, Motonobu Mihara
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Constant amplitude of tracking error signals generated from a head guide track and a performed track
Patent number: 5402411Abstract: An optical disk is adapted for use in an optical disk unit which irradiates a light beam spot on a target track on the optical disk and controls tracking of the light beam spot based on a tracking error signal which is generated based on a reflected light beam from the optical disk. The optical disk includes a disk shaped substrate, a spiral or concentric guide tracks provided on the substrate, a writable region provided on the substrate between two mutually adjacent track turns of the guide track, and a preformed track provided within the guide track and prerecorded with read-only information in a form of variations of a topological feature.Type: GrantFiled: March 2, 1993Date of Patent: March 28, 1995Assignee: Fujitsu LimitedInventors: Miyozo Maeda, Mineo Moribe, Susumu Satoh, Kyoko Miyabe -
Patent number: 5381396Abstract: A process for recording information on a magneto-optical recording medium according to a (2, 7) RLL modulated signal includes a step of setting an optical power of a laser beam to a high level state in response to a logic value "1" and a step of alternately switching the optical power of the laser beam between the high level state and a low level state in correspondence to a logic value "0" except for the bit that is immediately adjacent to the bit of the logic value "1.Type: GrantFiled: July 20, 1993Date of Patent: January 10, 1995Assignee: Fujitsu LimitedInventors: Tsutomu Tanaka, Keiji Shono, Yoshiyuki Namba, Koji Matsumoto, Miyozo Maeda
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Patent number: 5353265Abstract: A method for overwriting information in a magneto-optical memory medium which includes a simultaneous writing and erasing step of continuously irradiating a written information-carrying area of the recording layer of the memory medium with two different pulses from a single laser beam head in accordance with information to be written, regardless of the presence or absence of written information. A variation includes irradiating the written information-carrying area with an erasing pulse from a laser beam head, regardless of the presence or absence of written information, and then selectively irradiating the information-erased area with a writing pulse from another laser beam head in accordance with information to be written. According to these methods, it becomes possible to carry out a simple and high-speed overwriting with an increased and stabilized bit positioning accuracy.Type: GrantFiled: February 7, 1990Date of Patent: October 4, 1994Assignee: Fujitsu LimitedInventors: Miyozo Maeda, Yuji Inouye, Yasunobu Hashimoto, Ken-ichi Itoh, Seiya Ogawa
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Patent number: 5337303Abstract: A disk storage device includes a light source emitting a light, an objective lens for focusing the light on a surface of a recording film of a disk via a protection film protecting the recording film, and a motor for rotating the disk. A detector receives the light reflected by the surface of the recording film and reproduces information recorded on the recording film. The detector is located at a position where the following condition is satisfied:D.gtoreq.F.times.A.times..alpha.where D is the distance between the objective lens and the detector, F is the focal length of the objective lens, A is equal to F/t2 where t2 is the thickness of the protection film, and .alpha.is a constant equal to or greater than 1.0.Type: GrantFiled: February 19, 1993Date of Patent: August 9, 1994Assignee: Fujitsu LimitedInventor: Miyozo Maeda
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Patent number: 5214627Abstract: An optical disk provided with read-exclusive regions where previously recorded information can be read, and with write-enable regions where information can be written. Information not desired to be rewritten can be recorded on the read-exclusive regions. The write-enable regions are open to users to freely add information thereto and to re-write information recorded. This optical disk can thus be used in various fields.Type: GrantFiled: February 7, 1990Date of Patent: May 25, 1993Assignee: Fujitsu LimitedInventors: Kazuo Nakashima, Yasunobu Hashimoto, Miyozo Maeda, Seiya Ogawa
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Patent number: 5144601Abstract: A method of overwriting information in a magneto-optical memory medium which includes a simultaneous writing and erasing step of continuously irradiating a written information-carrying area of the recording layer of the memory medium with two different pulses from a single laser beam head in accordance with information to be written, regardless of the presence or absence of written information. A variation includes irradiating the written information-carrying area with an erasing pulse from a laser beam head, regardless of the presence or absence of written information, and the then selectively irradiating the information-erased area with a writing pulse from another laser beam head in accordance with information to be written. According to these methods, it becomes possible to carry out a simple and high-speed overwriting with an increased and stabilized bit positioning accuracy.Type: GrantFiled: February 14, 1991Date of Patent: September 1, 1992Assignee: Fujitsu LimitedInventors: Miyozo Maeda, Yuji Inouye, Yasunobu Hashimoto, Ken-ichi Itoh, Seiya Ogawa
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Patent number: 5138572Abstract: Recording and erasing optical information can be done by using an alloy film capable of forming two stable crystalline states differing in crystal texture and optical characteristics by being irradiated with optical energies under different conditions. A thin memory film preferably including 60 to 90 atom % of Indium (IN) and 10 to 40 atom % of Bismuth (Bi) is formed on a substrate.Type: GrantFiled: February 20, 1991Date of Patent: August 11, 1992Assignee: Fujitsu LimitedInventors: Nagaaki Koshino, Miyozo Maeda, Yasuyuki Goto, Itaru Shibata, Kenichi Utsumi, Akira Ushioda, Ken-ichi Itoh, Kozo Sueishi
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Patent number: 5072423Abstract: Recording and erasing optical information can be done by using an alloy film capable of forming two stable crystalline states differing in crystal texture and optical characteristics by being irradiated with optical energies under different conditions. The thin memory film preferably includes not more than 60 atom % of Gallium (Ga) and not less than 40 atom % of Antimony (Sb).Type: GrantFiled: April 4, 1991Date of Patent: December 10, 1991Assignee: Fujitsu LimitedInventors: Nagaaki Koshino, Miyozo Maeda, Yasuyuki Goto, Itaru Shibata, Kenichi Utsumi, Akira Ushioda, Ken-ichi Itoh, Kozo Sueishi
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Patent number: 5058061Abstract: Recording and erasing optical information can be done by using an alloy film capable of forming two stable crystalline states differing in crystal texture and optical characteristics by being irradiated with optical energies under different conditions. The memory film includes 35-45 atom % of indium (In) and 55-65 atom % of antimony (Sb). The memory film may include an additional element M selected from the group consisting of Al, Si, P, S, Zn, Ga, Ge, As, Se, Ag, Cd, Sn, Te, Tl, Pb, Bi, and a combination of these elements, the composition of the memory film being expressed by the formula (In.sub.x Sb.sub.1-x).sub.1-y M.sub.y.Type: GrantFiled: August 31, 1989Date of Patent: October 15, 1991Assignee: Fujitsu LimitedInventors: Nagaaki Koshino, Miyozo Maeda, Yasuyuki Goto, Itaru Shibata, Kenichi Utsumi, Akira Ushioda, Ken-ichi Itoh, Kozo Sueishi
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Patent number: 4947372Abstract: Recording and erasing optical information can be done by using an alloy film capable of forming two stable crystalline states differing in crystal texture and optical characteristics by being irradiated with optical energies under different conditions. The memory film includes 35-45 atom % of Indium (In) and 55-65 atom % of antimony (Sb).Type: GrantFiled: November 30, 1989Date of Patent: August 7, 1990Assignee: Fujitsu LimitedInventors: Nagaaki Koshino, Miyozo Maeda, Yasuyuki Goto, Itaru Shibata, Kenichi Utsumi, Akira Ushioda, Ken-ichi Itoh, Kozo Sueishi