Patents by Inventor Masatoshi Takao
Masatoshi Takao 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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Publication number: 20010019810Abstract: Phase-change type, reversible optical information recording medium, being possible for recording, reproducing, erasing, and rewriting of information, by use of a laser beam. This invention consists of recording thin film of ternary elements, for example, containing Ge, Te, Sb/or Bi or quaternary elements containing the fourth element of Se with which a part of Te is replaced, which is established on such surface—flat substrates as glass or plastics. In this case, the component ratio of Te and Se is selected not to be excess for other elements, such as Ge, Sb/or Bi so as to be fixed as stable compounds of stoichiometric compositions of GeTe, Sb2Te3/or Bi2Te3, or GeSe, Sb2Se3/Bi2Se3 when crystallized. Strictly speaking, a concentration of each component is selected to have proper ratio of the number of atomes each other so as to represent whole composition as the sum of each component. By this treatment, it is possible to have high crystallization speed and long cyclability of recording/erasing.Type: ApplicationFiled: January 22, 2001Publication date: September 6, 2001Inventors: Noboru Yamada, Kunio Kimura, Masatoshi Takao, Susumu Sanai
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Patent number: 6268107Abstract: Phase-change type, reversible optical information recording medium, being possible for recording, reproducing, erasing, and rewriting of information, by use of a laser beam. This invention, consists of recording thin film of ternary elements, for example, containing Ge, Te, Sb/or Bi or quaternary elements containing the fourth element of Se with which a part of Te is replaced, which is established on such surface—flat substrates as glass or plastics. In this case, the component ratio of Te and Se is selected not to be excess for other elements, such as Ge, Sb/or Bi so as to be fixed as stable compounds of stoichiometric compositions of GeTe, Sb2Te3/or Bi2Te3, or GeSe, Sb2Se3/Bi2Se3 when crystallized. Strictly speaking, a concentration of each component is selected to have proper ratio of the number of atoms each other so as to represent whole composition as the sum of each component. By this treatment, it is possible to have high crystallization speed and long cyclability of recording/erasing.Type: GrantFiled: April 28, 1993Date of Patent: July 31, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Noboru Yamada, Kunio Kimura, Masatoshi Takao, Susumu Sanai
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Patent number: 5385806Abstract: This invention, related to an optical information recording medium for recording, reproducing and erasing information by causing changes in the optical constant by using light, heat or other means, is intended to propose a recording film material of a novel composition in order to realize higher transfer rate of signals. Specifically, it is an alloy composed of indium (In) and A and B (A is at least one element selected from Ag, Cu, and B is at least one element selected from S, Se, Te), and more particularly it is composed in the vicinity of the stoichiometric compound of the above three-element system.Since the recording film material of this invention is fast in the rate of crystallization, it is possible to present an optical information recording medium that can cope with the forthcoming trend of higher transfer rate of signals.Type: GrantFiled: February 26, 1992Date of Patent: January 31, 1995Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Eiji Ohno, Noboru Yamada, Masatoshi Takao
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Patent number: 5294523Abstract: A rewritable phase-change type optical information recording medium having a recording film made of a material containing Te or In as a major component and further containing B or C.Type: GrantFiled: May 6, 1993Date of Patent: March 15, 1994Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Ken'chi Nagata, Susumu Sanai, Noboru Yamada, Masatoshi Takao
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Patent number: 5278011Abstract: Phase-change type, reversible optical information recording medium, being possible for recording, reproducing, erasing, and rewriting of information, by use of a laser beam. This invention consists of recording thin film of ternary elements, for example, containing Ge, Te, Sb/or Bi or quaternary elements containing the fourth element of Se with which a part of Te is replaced, which is established on such surface-flat substrates as glass or plastics. In this case, the component ratio of Te and Se is selected not to be excess for other elements, such as Ge, Sb/or Bi so as to be fixed as stable compounds of stoichiometric compositions of GeTe, Sb.sub.2 Te.sub.3 /or Bi.sub.2 Te.sub.3, or GeSe, Sb.sub.2 Se.sub.3 /Bi.sub.2 Se.sub.3 when crystallized. Strictly speaking, a concentration of each component is selected to have proper ratio of the number of atomes each other so as to represent whole composition as the sum of each component.Type: GrantFiled: April 28, 1993Date of Patent: January 11, 1994Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Noboru Yamada, Kunio Kimura, Masatoshi Takao, Susumu Sanai
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Patent number: 4847132Abstract: A protective layer which is applied to rewritable optical information recording medium comprising a substrate and a photosensitive thin film. When exposed to optical energy, the thin layer is capable of undergoing a reversible phase change by which an optical reflectivity is changed between two states. The protective layer is inhibiting the thermal damages of the substrate during light irradiation and also controlling thermal and optical boundary conditions. The protective layer is made of the mixture of mutually solid insoluble materials. The typical choice of the mixture of small crystalline grains of ZnS and noncrystalline SiO.sub.2.Type: GrantFiled: October 15, 1987Date of Patent: July 11, 1989Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masatoshi Takao, Kunio Kimura, Toshimitsu Kurumizawa, Kenichi Nagata
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Patent number: 4624914Abstract: An optical information recording medium comprising a substrate and a photosensitive thin layer consisting of Te, O and Pd. When exposed to optical energy, this thin layer is capable of undergoing a phase change by which an optical transmittance is changed. The addition of Pd results in an improvement of a response time to a great extent. This optical information recording medium is preferably made by a method using a Pd evaporation source and another source for Te+TeO.sub.2.Type: GrantFiled: September 12, 1985Date of Patent: November 25, 1986Inventors: Kunio Kimura, Masatoshi Takao, Nobuo Akahira, Mutsuo Takenaga
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Patent number: RE42222Abstract: Phase-change type, reversible optical information recording medium, being possible for recording, reproducing, erasing, and rewriting of information, by use of a laser beam. This invention, consists of recording thin film of ternary elements, for example, containing Ge, Te, Sb/or Bi or quaternary elements containing the fourth element of Se with which a part of Te is replaced, which is established on such surface—flat substrates as glass or plastics. In this case, the component ratio of Te and Se is selected not to be excess for other elements, such as Ge, Sb/or Bi so as to be fixed as stable compounds of stoichiometric compositions of GeTe, Sb2Te3/or Bi2Te3, or GeSe, Sb2Se3/Bi2Se3 when crystallized. Strictly speaking, a concentration of each component is selected to have proper ratio of the number of atoms each other so as to represent whole composition as the sum of each component. By this treatment, it is possible to have high crystallization speed and long cyclability of recording/erasing.Type: GrantFiled: March 14, 2003Date of Patent: March 15, 2011Assignee: Matsushita Electronic Industrial Co., Ltd.Inventors: Norboru Yamada, Kunio Kimura, Masatoshi Takao, Susumu Sanai