Patents by Inventor Yoshihiro Hamakawa
Yoshihiro Hamakawa 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: 4820915Abstract: A color sensor has a layered body obtained by stacking a first photoelectric sensor which is constituted by an amorphous semiconductor having a "PIN" structure and a spectral sensitivity which has a peak with respect to blue light and a second photoelectric sensor which is constituted by an amorphous semiconductor having a "PIN" structure and a spectral sensitivity which has a peak with respect to red light, so that a p-n junction is formed therebetween, and a pair of electrodes with each of the electrodes being provided at a respective end of the body, at least one of the pair of electrodes being transparent. A color measuring apparatus uses the color sensor with a bias voltage supply for supplying three different bias voltages between the sensor and the pair of electrodes, a photo-current detector for detecting photo-currents for each bias voltage and a color discriminator for discriminating incident light color on the basis of the detected photo-currents.Type: GrantFiled: October 5, 1987Date of Patent: April 11, 1989Assignee: Yamatake-Honeywell Co., Ltd.Inventors: Yoshihiro Hamakawa, Funio Koike, Tetsuya Miyagishi
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Patent number: 4814921Abstract: Multilayered magnetic films of the invention comprising at least two unit magnetic films each of which has a thickness of from 0.05 to 0.9 .mu.m and includes a plurality of ferromagnetic layers each having a thickness of from 0.01 to 0.2 .mu.m and a 1 nm to 10 nm thick first intermediate layer consisting of a ferromagnetic, nonmagnetic or antiferromagnetic material and provided between adjacent ferromagnetic layers, and a second intermediate layer having a thickness of from 10 to 40 nm, consisting of a nonmagnetic or antiferromagnetic material and provided between the at least two unit magnetic films. The multilayered magnetic film is suitable as a pole of a thin-film magnetic head. An underlayer may be further provided between the magnetic film and a substrate whereby a multilayered magnetic film having good characteristics can be obtained.Type: GrantFiled: February 1, 1988Date of Patent: March 21, 1989Assignee: Hitachi, Ltd.Inventors: Yoshihiro Hamakawa, Kazuo Shiiki, Yoshihiro Shiroishi, Isamu Yuitoo, Hitoshi Numasaka, Noriyuki Kumasaka, Shigekazu Otomo, Eijin Moriwaki
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Patent number: 4773942Abstract: A flexible photovoltaic device includes a flexible substrate and a photovoltaic device body. The flexible substrate is a metal foil or film provided with an electric insulating layer of a material having an electric conductivity of not more than 10.sup.-7 (.OMEGA..multidot.cm.).sup.-1 at the time of light impinging and made of an amorphous silicon nitride containing hydrogen.Type: GrantFiled: March 3, 1986Date of Patent: September 27, 1988Assignee: Kanegafuchi Kagaku Kogyo Kabushiki KaishaInventors: Yoshihiro Hamakawa, Yoshihisa Tawada, Kazunori Tsuge, Masanobu Izumina
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Patent number: 4766039Abstract: A magnetic head comprising a magnetic film in at least a part of a magnetic circuit, at least a part of the magnetic film being formed in contact with, or being exposed to, an oxide or oxygen at least in a heating step at 150.degree. C. or higher in a process for preparing the magnetic head is disclosed. An amorphous alloy film for the magnetic film has the following composition formula to give distinguished head characteristics without any oxidation:Co.sub.a T.sub.b Zr.sub.c N.sub.dwhere T is at last one of Nb, Ta, W, Mo, V and Cr; N is at least one of Au, Pt and Ag; d.gtoreq.1, b>0, b.sub.1 +b.sub.2 +2c.gtoreq.10, a+d.gtoreq.80, -1.ltoreq.(3c-b.sub.1 -3b.sub.2 -5b.sub.3 -3b.sub.4 -4d)/(c+b.sub.1 +b.sub.2 +b.sub.3 +b.sub.4 +d).ltoreq.1, and a+b+c+d=100, where b.sub.1 is a Nb concentration, b.sub.2 is a Ta concentration, b.sub.3 is a W concentration, b.sub.4 is sum total of Mo, Cr and V concentrations and b=b.sub.1 +b.sub.2 +b.sub.3 +b.sub.4.Type: GrantFiled: June 17, 1986Date of Patent: August 23, 1988Assignee: Hitachi, Ltd.Inventors: Shigekazu Otomo, Noriyuki Kumasaka, Noritoshi Saito, Takeo Yamashita, Kazuo Shiiki, Yoshihiro Hamakawa
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Patent number: 4762755Abstract: A ferromagnetic material is composed of an iron alloy which contains 2 to 12% by weight of silicon and 5 to 25% by weight of at least one element selected from the group consisting of ruthenium, rhodium, palladium, iridium, platinum, gold and silver. This ferromagnetic material exhibits a high saturation flux density and good corrosion resistance. Excellent magnetic characteristics are obtained by a multilayered film which is obtained by alternatingly laminating the above ferromagnetic material and a spacer layer composed of other material. Further, a markedly increased recording density is exhibited by a magnetic head for perpendicular magnetic recording, when the end of the main pole is composed of the ferromagnetic material.Type: GrantFiled: October 29, 1984Date of Patent: August 9, 1988Assignee: Hitachi, Ltd.Inventors: Kazuo Shiiki, Noriyuki Kumasaka, Yoshihiro Shiroishi, Hitoshi Nakamura, Yoshihiro Hamakawa, Noritoshi Saito, Shigeo Aoki, Kiminari Shinagawa, Mitsuhiro Kudo
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Patent number: 4760481Abstract: Disclosed is a thin film magnetic head having a structure wherein the main portion of a coil consists of a copper or copper alloy layer and its upper surface is covered with a thin film mask consisting of titanium, titanium oxide, chromium and/or chromium oxide. The magnetic head of the invention can prevent the occurrence of projecting etching residues at the upper edge portion of the coil and can easily increase the cross-sectional area and the winding density of the coil. Furthermore, when the thin film mask consists of titanium and/or titanium oxide, a titanium diffusion prevention film consisting of chromium, for example, is interposed between the thin film mask and the copper or copper alloy, so that the resistance change of the coil scarcely takes place owing to heat treatment in a production process after the formation of the coil and the head reliability can be further improved.Type: GrantFiled: July 22, 1986Date of Patent: July 26, 1988Assignee: Hitachi, Ltd.Inventors: Isamu Yuito, Eijin Moriwaki, Kazuo Shiiki, Keiko Shiokawa, Yoshihiro Hamakawa, Saburo Suzuki, Harunobu Saito
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Patent number: 4758399Abstract: A method of forming a substrate for manufacturing single crystal thin films, wherein the substrate is a replica pattern of a monocrystalline or single crystal cleavage plane. Such replica pattern may be formed by pressing a material in a softened state against the cleavage plane of the single crystal, with subsequent hardening, and also, by subjecting the single crystal cleavage plane to vapor deposition or plating, and thereafter removing the formed layer from the single crystal cleavage plane.Type: GrantFiled: November 7, 1986Date of Patent: July 19, 1988Assignee: Yoshihiro HamakawaInventors: Yoshihiro Hamakawa, Hideyuki Takakura
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Patent number: 4735396Abstract: The invention is directed to a substrate for manufacturing single crystal thin films, wherein the substrate is a replica pattern of a monocrystalline or single crystal cleavage plane. Such replica pattern may be formed by pressing a material in a softened state against the cleavage plane of the single crystal, with subsequent hardening, and also, by subjecting the single crystal cleavage plane to vapor deposition or plating, and thereafter removing the formed layer from the single crystal cleavage plane.Type: GrantFiled: May 10, 1985Date of Patent: April 5, 1988Assignee: Yoshihiro HamakawaInventors: Yoshihiro Hamakawa, Hideyuki Takakura
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Patent number: 4717630Abstract: The invention is directed to a substrate for manufacturing single crystal thin films wherein the substrate is a replica pattern of a monocrystalline or single crystal cleavage plane. Such replica pattern may be formed by pressing a material in a softened state against the cleavage plane of the single crystal, with subsequent hardening, and also, by subjecting the single crystal cleavage plane to vapor deposition or plating, and thereafter removing the formed layer from the single crystal cleavage plane.Type: GrantFiled: May 9, 1986Date of Patent: January 5, 1988Assignee: Yoshihiro HamakawaInventors: Yoshihiro Hamakawa, Hideyuki Takakura
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Patent number: 4670762Abstract: A process for preparing an amorphous silicon semiconductor comprising steps of plasma decomposing silicon compounds and carrying out photolysis of the silicon compounds. According to the process, a growth rate of the semiconductor is greatly increased. The obtained amorphous silicon semiconductor has excellent electrical and optical properties and is useful as a photovoltaic element.Type: GrantFiled: July 3, 1985Date of Patent: June 2, 1987Assignee: Kanegafuchi Kagaku Kogyo Kabushiki KaishaInventors: Kazunori Tsuge, Yoshihisa Tawada, Yoshihiro Hamakawa
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Patent number: 4634601Abstract: The production of a semiconductor by the glow discharge decomposition of a silane type gas is accomplished advantageously by a method which comprises effecting the glow discharge decomposition of introduced silane type gas with a plurality of opposed electrodes disposed substantially perpendicularly to a substrate and insulated from the ground potential and subsequently allowing the product of the decomposition to be deposited on the substrate disposed so as to be exposed to the introduced silane type gas. The semiconductor obtained by this method is free from the drawbacks suffered by the conventional method using a power source of high frequency.Type: GrantFiled: March 26, 1985Date of Patent: January 6, 1987Assignee: Kanegafuchi Kagaku Kogyo Kabushiki KaishaInventors: Yoshihiro Hamakawa, Hideo Yamagishi, Yoshihisa Tawada
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Patent number: 4612409Abstract: A flexible photovoltaic device includes a flexible substrate and a photovoltaic device body. The flexible substrate is a metal foil or film provided with an electric insulating layer of a material having an electric conductivity of not more than 10.sup.-7 (.OMEGA..multidot.cm.).sup.-1 during of light impingement and selected from a heat resistant polymer, a metal oxide, a crystalline or amorphous silicon compound, and an organometallic compound.Type: GrantFiled: November 4, 1982Date of Patent: September 16, 1986Assignee: Kanegafuchi Kagaku Kogyo Kabushiki KaishaInventors: Yoshihiro Hamakawa, Yoshihisa Tawada, Kazunori Tsuge, Masanobu Izumina
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Patent number: 4544423Abstract: A process for preparing an amorphous silicon semiconductor comprising steps of plasma decomposing silicon compounds and carrying out photolysis of the silicon compounds. According to the process, the growth rate of the semiconductor is greatly increased. The obtained amorphous silicon semiconductor has excellent electrical and optical properties and is useful as a photovoltaic element.Type: GrantFiled: February 10, 1984Date of Patent: October 1, 1985Assignee: Kanegafuchi Kagaku Kogyo Kabushiki KaishaInventors: Kazunori Tsuge, Yoshihisa Tawada, Yoshihiro Hamakawa
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Patent number: 4499331Abstract: An amorphous silicon semiconductor of the general formula: a-Si.sub.(1-x-y) C.sub.x N.sub.y containing hydrogen and/or fluorine, which provides an amorphous silicon PIN junction photovoltaic device having an improved conversion efficiency when it is used as a P-type or N-type layer on the light impinging side of the PIN junction photovoltaic device. Also, the conversion efficiency of an amorphous silicon PIN junction photovoltaic device is improved by using a two-layer film structure of ITO and SnO.sub.2 as a transparent electrode for the photovoltaic device, with the SnO.sub.2 layer contacting the P or N layer. The improvement is particularly marked in the case of heterojunction photovoltaic devices.Type: GrantFiled: November 17, 1983Date of Patent: February 12, 1985Assignee: Kanegafuchi Kagaku Kogyo Kabushiki KaishaInventors: Yoshihiro Hamakawa, Yoshihisa Tawada
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Patent number: 4496788Abstract: A photovoltaic device comprising at least one crystalline and one amorphous semiconductor region with different photosensitivity is provided to absorb light in a wide range of wavelength, and serves, for example, as a solar battery or a color sensor. Amorphous or microcrystalline semiconductor regions comprising those devices can be deposited easily and in a continuous manufacturing process by the use of a low temperature process, and this allows manufacture of a photovoltaic device at low cost.Type: GrantFiled: September 2, 1983Date of Patent: January 29, 1985Assignee: Osaka Transformer Co., Ltd.Inventors: Yoshihiro Hamakawa, Hiroaki Okamoto, Kouji Okuda
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Patent number: 4491682Abstract: An amorphous silicon semiconductor of the general formula: a-Si.sub.(1-x-y) C.sub.x N.sub.y containing hydrogen and/or fluorine, which provides an amorphous silicon PIN junction photovoltaic device having an improved conversion efficiency when it is used as a P-type or N-type semiconductor in the layer on the light impinging side of the PIN junction photovoltaic device. Also, the conversion efficiency of an amorphous silicon PIN junction photovoltaic device is improved by using a film of ITO and SnO.sub.2 two layer structure as a transparent electrode for the photovoltaic device with the SnO.sub.2 layer contacting the P or N layer, and the improvement is particularly marked in the heterojunction photovoltaic device.Type: GrantFiled: November 17, 1983Date of Patent: January 1, 1985Assignee: Kanegafuchi Kagaku Kogyo Kabushiki KaishaInventors: Yoshihiro Hamakawa, Yoshihisa Tawada
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Patent number: 4453184Abstract: A solid state imaging device using a non-crystalline semiconductor material as a photoconductive member. The photoconductive member is arranged in repetitive p-i-n layers such that an opto electromotive force is developed sufficient to drive charges to an integrated scanning circuit even in the absence of an external bias voltage.Type: GrantFiled: December 9, 1981Date of Patent: June 5, 1984Assignee: Fuji Photo Film Co., Ltd.Inventors: Yoshihiro Hamakawa, Yosuke Nakajima
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Patent number: 4450316Abstract: An amorphous silicon semiconductor of the general formula: a-Si.sub.(1-x-y) C.sub.x N.sub.y containing hydrogen and/or fluorine, which provides an amorphous silicon PIN junction photovoltaic device having an improved conversion efficiency when it is used as a P-type or N-type layer on the light impinging side of the PIN junction photovoltaic device. Also, the conversion efficiency of an amorphous silicon PIN junction photovoltaic device is improved by using a two-layer film structure of ITO and SnO.sub.2 as a transparent electrode for the photovoltaic device, with the SnO.sub.2 layer contacting the P or N layer. The improvement is particularly marked in the case of heterojunction photovoltaic devices.Type: GrantFiled: July 19, 1982Date of Patent: May 22, 1984Assignee: Kanegafuchi Kagaku Kogyo Kabushiki KaishaInventors: Yoshihiro Hamakawa, Yoshihisa Tawada
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Patent number: 4410559Abstract: In a method of forming a layer of an amorphous silicon compound by subjecting a gas containing a silane compound to glow discharge decomposition, the improvement wherein the substrate on which the amorphous silicon compound is to be deposited is positioned within 3 cm above or below the end of a positive column formed by said glow discharge.Type: GrantFiled: October 29, 1981Date of Patent: October 18, 1983Inventors: Yoshihiro Hamakawa, Yoshihisa Tawada
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Patent number: 4388482Abstract: A p-i-n amorphous silicon photovoltaic cell of improved conversion efficiency is obtained by incorporating, as either the p or n type side of the cell exposed to the incident light, an amorphous semiconductor which satisfies the requirements that the optical band gap, Eg.opt, be not less than about 1.85 eV, the electric conductivity be not less than about 10.sup.-8 (.OMEGA..cm).sup.-1 the p-i-n junction diffusion potential, Vd, be not less than about 1.1 volts, and be formed of a substance represented by one of the general formulas, a-Si.sub.1-x C.sub.x and a-Si.sub.1-y N.sub.y.Type: GrantFiled: May 19, 1981Date of Patent: June 14, 1983Inventors: Yoshihiro Hamakawa, Yoshihisa Tawada