Patents by Inventor Toshihiko Ohta
Toshihiko Ohta 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: 5940728Abstract: A process for manufacturing electronic circuits, according to which soldering can be carried out without using flux by applying a metal surface treatment procedure which allows oxide film, organic matters, carbon or the like on the surface of metal to be easily removed without using a complex process nor unfavorably affecting electronic devices or circuit substrates. A process of connecting an electronic device and a circuit substrate by means of solder comprises the steps of irradiating the solder with a laser beam to clean the solder, aligning and mounting the electronic device on the circuit substrate, and hot-melting said solder in a low-oxygen content atmosphere to bond the electronic device and the circuit substrate.Type: GrantFiled: May 15, 1996Date of Patent: August 17, 1999Assignee: Hitachi, Ltd.Inventors: Kaoru Katayama, Hiroshi Fukuda, Shinichi Kazui, Toshihiko Ohta, Yasuhiro Iwata, Mitsugu Shirai, Mitsunori Tamura
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Patent number: 5905611Abstract: The present invention provides a thin film head having a magnetoresistance effect element which includes at least two magnetic films, a nonmagnetic film sandwiched between the magnetic films, and leads connected to the magnetoresistance effect element wherein the width of one of the magnetic films, which essentially responds to a signal magnetic field, is not more than a distance between leads. The present invention provides a thin film head having a magnetoresistance effect element which includes at least two magnetic films and a nonmagnetic film sandwiched between the magnetic films, which makes use of a change in magnetic resistance caused by spin-dependent scattering, wherein at least a portion of one magnetic films, which essentially respond to a signal magnetic field extends in a direction same as that of the signal magnetic field.Type: GrantFiled: May 22, 1997Date of Patent: May 18, 1999Assignee: Kabushiki Kaisha ToshibaInventors: Hiroaki Yoda, Yuichi Ohsawa, Kohichi Tateyama, Reiko Kondoh, Toshihiko Ohta, Junichi Akiyama, Hitoshi Iwasaki
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Patent number: 5731066Abstract: In an electronic circuit device having an input/output pin junction electrode, in order to remarkably improve the junction characteristics such as wettability and junction strength and to drastically simplify the production process, in forming an electronic circuit board in which glass ceramics is used for board material and a wiring conductor and junction electrode wherein the Cu is sized to extend beyond the pin hole so that solder only contacts it and not the ceramic circuit board. The wiring and junction electrode is formed in a same process while forming a cover coat on the electrode using board material, and Au or Au--Ni laminated film is formed on this electrode as occasion demands, and then an electronic component is connected thereto using a solder such a Au--Sn or Au--Ge.Type: GrantFiled: October 23, 1995Date of Patent: March 24, 1998Assignee: Hitachi, Ltd.Inventors: Akihiro Ando, Osamu Yamada, Ryohei Satoh, Takashi Inoue, Masahide Okamoto, Fumiyuki Kobayashi, Toshihiko Ohta, Minoru Tanaka
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Patent number: 5499668Abstract: Oxide films, and residues of organic matters, carbons, if any, are removed from a metal surface simply without using complicated steps and without giving adverse effects on electronic parts or electronic devices by irradiating the metal surface with a laser beam of lower energy level than energy capable of changing the metal surface structure, thereby cleaning the metal surface.Type: GrantFiled: October 27, 1994Date of Patent: March 19, 1996Assignee: Hitachi, Ltd.Inventors: Kaoru Katayama, Shinichi Kazui, Yasuhiro Iwata, Hiroshi Fukuda, Toshihiko Ohta
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Patent number: 5461527Abstract: A member having a first and a second magnetic layer are magnetostatically coupled and laminated and the first magnetic layer formed on a magneto-resistive element, for creating the exchange coupling on the magneto-resistive element and the first magnetic layer. The member is formed by sequentially laminating a first ferromagnetic layer magnetized in a sense along the direction of the longitudinal bias of the magneto-resistive element, non-magnetic layer and second ferromagnetic layer magnetized in a direction opposite to the magnetized direction of the first ferromagnetic layer, for example.Type: GrantFiled: November 14, 1994Date of Patent: October 24, 1995Assignee: Kabushiki Kaisha ToshibaInventors: Junichi Akiyama, Yuichi Ohsawa, Hitoshi Iwasaki, Reiko Kondoh, Kohichi Tateyama, Toshihiko Ohta, Hiroaki Yoda
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Patent number: 5414786Abstract: An optical waveguide component which has end faces to be connected with optical fiber connectors by means of guide pins, comprises an optical waveguide component body having an optical waveguide core portion, and a resin mold cladding portion covering all the faces of the optical waveguide component body except for the end faces of the optical waveguide component body. Each end face of the resin mold portion has guide pin holes which were formed with the optical waveguide core portion being used as a positioning reference. Since the guide pin holes for connection with the optical fiber connectors are formed in the resin mold portion which, preferably has some elasticity and which covers the optical waveguide component body, the guide pin holes and a substrate are not broken even if subjected to a load after connection.Type: GrantFiled: October 4, 1993Date of Patent: May 9, 1995Assignee: The Furukawa Electric Co., Ltd.Inventors: Toshihiko Ohta, Takashi Shigematsu, Takeo Shimizu, Shiro Nakamura
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Patent number: 5361382Abstract: A method of connecting waveguides and optical fibers includes the steps of forming the waveguides and a marker at the same time on a waveguide substrate when patterning the waveguides by a photolithography method, forming a clad layer on a region other than another region when the marker is formed so as to embed the waveguides, and forming a fitting pin groove at a position corresponding to a position of the marker. By using this fitting pin groove, a waveguide module and an optical fiber connector are connected so as to connect each of the waveguides and each of the optical fibers with each other. With this method, waveguides and optical fibers can be aligned and connected with each other easily and in a short period of time without employing an expensive aligning device.Type: GrantFiled: January 7, 1993Date of Patent: November 1, 1994Assignee: The Furukawa Electric Co., Ltd.Inventors: Shirou Nakamura, Takeo Shimizu, Hisaharu Yanagawa, Toshihiko Ohta, Takashi Shigematsu, Toshihiro Ochiai, Koichi Kobayashi
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Patent number: 5329413Abstract: A magnetoresistance sensor of this invention is designed to detect a magnetic field on the basis of a change in electric resistance of a magnetoresistance layer, and includes a substrate, the magnetoresistance layer, a magnetization stabilizing layer for stabilizing magnetization of the magnetoresistance layer, and an electrical conductive layer formed on the magnetoresistance layer or the magnetization stabilizing layer. The sensor is characterized in that the magnetoresistance layer and the magnetization stabilizing layer are stacked on each other such that the layers are magnetically coupled to each other at their two end regions with an exchange coupling force higher than that at the remaining region. With this arrangement, there is provided a magnetoresistance sensor having high sensitivity, which can apply a desired bias magnetic field to the MR layer while preventing the bias magnetic field from being disturbed by a magnetic field from a magnetic recording medium or the like.Type: GrantFiled: January 5, 1993Date of Patent: July 12, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Reiko Kondoh, Hitoshi Iwasaki, Junichi Akiyama, Yuichi Ohsawa, Toshihiko Ohta
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Patent number: 5249100Abstract: Disclosed is an electronic circuit device in which the solder (14) connecting lead pins (6) to the ceramic substrate (2) has a melting point of 356.degree. C. to 450.degree. C. and has a tensile strength being low in such an extent that a thermal contraction stress generated in a cooling process of the solder (14) from the melting point thereof is low and the substrate (2) does not break. The solder (14) is a Au-Ge alloy containing 10-15 wt % of Ge. Electronic circuit devices, which employ the above solder (14) in the connections, are free from damages in the ceramic wiring substrate (2) due to the bonding. Further, when the electronic circuit device undergoes a series of assembly processes after the above bonding, such solder (14) does not melt, and wettability of such solder (14) is favorable.Type: GrantFiled: May 11, 1990Date of Patent: September 28, 1993Assignee: Hitachi, Ltd.Inventors: Ryohei Satoh, Kazuo Hirota, Takaji Takenaka, Hideki Watanabe, Toshinori Ameya, Toshihiko Ohta
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Patent number: 5222168Abstract: A method for stacking ferrules of a stacked-type optical connector wherein stacking portions for stacking are provided in corresponding positions of each ferrule, the individual ferrules are stacked with the corresponding individual stacking portions aligned, and a plurality of ferrules are simultaneously stacked up with stacking members which work in cooperation with those corresponding stacking portions in such a manner that the ferrules can practically float with a specific degree of freedom to allow a gap between the ferrules, and a stacked-type optical connector assembled according to this method.Type: GrantFiled: December 6, 1991Date of Patent: June 22, 1993Assignee: The Furukawa Electric Co., Ltd.Inventors: Masami Saito, Shinichiro Ohta, Hiroyuki Yamada, Etsuo Tanabe, Toshihiko Ohta
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Patent number: 5185825Abstract: Disclosed in an optical switching connector provided with a first and second ferrule disposed with end faces thereof abutting on each other and two reference pins disposed in parallel at a predetermined interval. The first and second ferrules have two parallel pin holes, respectively. The two reference pins are inserted in the pin holes. The pin holes have an elongated sectional shape enabling the reference pins to move laterally by exactly a certain movement pitch. The first and second ferrules are able to be positioned at one position determined by one of the inside surfaces of the pin holes being pressed against the reference pins and another position determined by the other inside surfaces of the pin holes being pressed against the reference pins.Type: GrantFiled: September 30, 1991Date of Patent: February 9, 1993Assignee: The Furukawa Electric Co., Ltd.Inventors: Takashi Shigematsu, Seiichi Imamizo, Koichi Takagi, Toshihiko Ohta, Jun Yamakawa
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Patent number: 5022140Abstract: In a magnetic head a metal magnetic layer and a non-magnetic layer are sequentially formed on a pair of magnetic cores in which track widths are formed by a predetermined pitch. The metal magnetic layer and the non-magnetic layer formed outside the track widths are removed while leaving the track widths formed in said magnetic cores, thereby forming a regulation groove. The track widths of one magnetic core from which the metal magnetic layer and the non-magnetic layer are removed are caused to oppose those of the other magnetic core. Glass as an adhesive is filled in the regulation groove and melted to bond the magnetic cores so that a gap having the metal magnetic layer is formed. The pair of magnetic cores bonded to form the gap therebetween are cut by a predetermined pitch to form a magnetic head.Type: GrantFiled: March 8, 1990Date of Patent: June 11, 1991Assignee: Kabushiki Kaisha ToshibaInventors: Shoji Tsutaki, Kazuyoshi Fuse, Toshihiko Ohta
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Patent number: 4990067Abstract: A hermetic compressor according to the present invention has an improved operating efficiency for use in a cold storage chamber, freezing chamber or the like . The compression includes a suction pipe which is formed by a material having heat conductivity lower than that of a casing of the hermetic compressor so that heat of the closed casing is not easily transmitted to the suction pipe. In this manner heating of the drawn in cooling medium gas is inhibited, and thus, cooling efficiency can be improved by preventing discharge of a low density cooling medium into the cooling system through compression of the expanded cooling medium gas.Type: GrantFiled: August 7, 1989Date of Patent: February 5, 1991Assignee: Matsushita Refrigeration CompanyInventors: Hiroshi Sasano, Hideki Kawai, Toshihiko Ohta
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Patent number: 4910394Abstract: A transducer for an IC card having a built-in semiconductor memory performs signal conversion by magnetic coupling to read out data. This transducer comprises a substrate, which has a first section of a predetermined thickness, and a second section, thinner than and formed in contact with the first section. A pair of first thin-film spiral coils, both would in the same direction, are formed on the first section of the substrate, and thin-film connection pads, respectively coupled to the first spiral coils, are formed on the second section. Then, an insulating film is deposited on the substrate and the first spiral coil. Through holes are made in the insulating film, thus exposing the center portion of the first spiral coil. A pair of second thin-film spiral coils, both also would in the same direction, are formed on the insulating film such that they are coupled to the first spiral coils.Type: GrantFiled: February 4, 1988Date of Patent: March 20, 1990Assignee: Kabushiki Kaisha ToshibaInventor: Toshihiko Ohta
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Patent number: 4851508Abstract: Polyester fibers having both a high strength and a high modulus prepared from ethylene terephthalate polyester, and having an intrinsic viscosity of not less than 1.0 and an initial tensile modulus is not less than 130 g/d, said intrinsic viscosity being determined in a mixed solvent of p-chlorophenol and tetrachloro ethane (3:1) at 30.degree. C. Processes for producing the fibers are also disclosed.Type: GrantFiled: June 30, 1987Date of Patent: July 25, 1989Assignee: Toyo Boseki Kabushiki KaishaInventors: Kazuo Kurita, Masahiro Hayashi, Toshihiko Ohta, Hideaki Ishihara, Fujio Okada, Wataru Yoshikawa, Akira Chiba, Susumu Tate
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Patent number: 4825056Abstract: A thin-film type electromagnetic transducer formed on a nonmagnetic substrate by a thin-film forming process. The transducer includes a magnetic core formed on the substrate by the thin-film forming process, and a conductor coil formed on the substrate by the thin-film forming process, so as to be wound around the core. The core is shaped so that a leakage flux generated along the plane of the substrate is greater than that generated in a direction intersecting with the plane of the substrate, the leakage fluxes being generated from the core when a current is supplied to the coil. In a method for transferring signals from the thin-film type electromagnetic transducer described above, a magnetic head is located so as to face that region of the core of the transducer where the maximum leakage flux is generated.Type: GrantFiled: November 20, 1986Date of Patent: April 25, 1989Assignee: Kabushiki Kaisha ToshibaInventors: Toshihiko Ohta, Fumio Izawa
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Patent number: 4824619Abstract: A process for producing polyethylene drawn filaments and drawn films which comprises molding under pressure a mixture of 51 to 90 parts by weight of polyethylene powder having a weight average molecular weight of at least 4.times.10.sup.5 and having no history of being molten or dissolved after polymerization, and 49 to 10 parts by weight of a solvent at a temperature lower than the melting point of the mixture, and then hot-stretching the molded product.Type: GrantFiled: December 21, 1987Date of Patent: April 25, 1989Assignee: Toyo Boseki Kabushiki KaishaInventors: Fujio Okada, Toshihiko Ohta
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Patent number: 4818853Abstract: A data card which can be resiliently flexed to a degree. The data card includes a laminated structure member having at least a synthetic resin protective layer and a ferromagnetic material layer, an electric circuit device embedded in the laminated structure member and an electro-magnetic transducer having a pair of coils which are formed on the laminated structure member. The pair of coils are coupled to the electric circuit device for generating magnetic fluxes of opposite directions with each other according to an information signal applied from the electric circuit device. Alternatively, the pair of coils are provided for receiving magnetic fluxes of opposite directions with each other and coupled to the electric circuit device for applying an electric signal generated by the magnetic fluxes of opposite directions thereto.Type: GrantFiled: May 26, 1987Date of Patent: April 4, 1989Assignee: Kabushiki Kaisha ToshibaInventors: Toshihiko Ohta, Kazuyoshi Fuse, Kunio Ohmi, Toshiaki Sato, Masayuki Shinozaki
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Patent number: 4800121Abstract: An optical fiber cord or cable comprising at least one optical fiber and at least one tensile member for reinforcing said optical fiber, said tensile member comprising at least one polyethylene filament having a viscosity average molecular weight of not less than 200,000, a tenacity of not less than 20 g/d and a tensile modulus of not less than 600 g/d.Type: GrantFiled: May 29, 1987Date of Patent: January 24, 1989Assignee: Toyo Boseki Kabushiki KaishaInventors: Toshihiko Ohta, Fujio Okada, Masahiro Hayashi
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Patent number: 4779953Abstract: An optical fiber cord or cable comprising at least one optical fiber and at least one tensile member for reinforcing said optical fiber, said tensile member comprising at least one polyethylene filament having a viscosity average molecular weight of not less than 200,000, a tenacity of not less than 20 g/d and a tensile modulus of not less than 600 g/d.Type: GrantFiled: July 21, 1986Date of Patent: October 25, 1988Assignee: Toyo Boseki Kabushiki KaishaInventors: Toshihiko Ohta, Fujio Okada, Masahiro Hayashi