Patents by Inventor Yoshihisa Ishikawa
Yoshihisa Ishikawa 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: 7777389Abstract: A rotating electrical machine comprises a stator and a rotor; the stator comprising a stator core having teeth and slots, and stator windings disposed in the slots, wherein the stator core is made of laminated steel sheets, teeth and slots of the steel sheet are made by etching, and the thickness of the steel sheet is between 0.05 mm and 0.30 mm. Specifically, it is preferable that the steel sheet used herein be a silicon steel sheet containing crystalline particles.Type: GrantFiled: July 12, 2007Date of Patent: August 17, 2010Assignee: Hitachi, Ltd.Inventors: Teruyoshi Abe, Motoya Ito, Fumio Tajima, Yoshihisa Ishikawa
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Patent number: 7759837Abstract: Stator claw poles are disposed at a stator core at a position facing opposite a rotor so as to alternately range from the two sides along the axial direction. With a plurality of magnetic poles thus formed, the distance by which the gap between the front end portions of the stator claw poles and the stator outer circumference ranges is increased, which, in turn, reduces the reactance guided to a stator coil. It is ensured that the magnetic reluctance manifesting between the front end portions of the stator claw poles and an enclosing member that holds the stator core, facing opposite the centers of the claw poles along the circumferential direction, is greater than the magnetic reluctance manifesting between the front portions and the stator core enclosing member facing opposite the front end portions.Type: GrantFiled: June 18, 2008Date of Patent: July 20, 2010Assignee: Hitachi, Ltd.Inventors: Toshio Ishikawa, Minoru Yabuki, Yoshihisa Ishikawa, Kazuo Tahara
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Patent number: 7701109Abstract: It is an object of the present invention to make it possible to easily wind a stator winding, enhance an occupied ratio in a stator core, reduce a winding resistance because there is no coil end, and change a field magnetic flux in accordance with a use. Stator pawl magnetic poles of a stator core extend from both sides in an axial direction alternately at locations opposed to a rotor to form a plurality of magnetic poles. With this stator core, it is only necessary to annularly wind a stator winding. Therefore, it is possible to enhance operability and an occupied ratio, and since there is no coil end, it is possible to reduce winding resistance. Since the rotor is a Randall type rotor having a field winding and a rotor pawl magnetic pole, it is possible to change the field magnetic flux in accordance with a use.Type: GrantFiled: December 5, 2007Date of Patent: April 20, 2010Assignee: Hitachi, Ltd.Inventors: Toshio Ishikawa, Minoru Yabuki, Hiroshi Kanazawa, Yuji Enomoto, Yoshihisa Ishikawa
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Publication number: 20090230806Abstract: An electric motor comprising a rotor having plural magnetic poles in the circumferential direction; and a stator whose teeth are disposed opposite to the periphery of the rotor, with an air gap interposed between the rotor and the stator, wherein the coil conductors are wound on the stator so that two stator magnetic poles may be formed by two coil units of a phase wound around stator teeth within the range of 360 electrical degrees subtended by the magnetic poles of the rotor; each of the two coil units forming the stator magnetic poles spans an electrical angle less than 180 electrical degrees; the two coil turns forming the two stator magnetic poles are laid out so that they may not overlap each other; and the coil conductors are so wound that the adjacent stator magnetic poles exhibit opposite magnetic polarities.Type: ApplicationFiled: February 26, 2009Publication date: September 17, 2009Applicant: Hitachi, Ltd.Inventors: Kenji Miyata, Yoshihisa Ishikawa
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Publication number: 20090102314Abstract: A rotating electrical machine includes: a stator that includes two stator stages each constituted with a plurality of claw poles extending toward opposite sides along an axial direction at alternate positions and a ring-shaped core back that forms a magnetic path between the claw poles, the two stator stages being stacked over along the axial direction; a stator winding formed by winding a coil in a ring shape and disposed in a space enclosed by the claw poles and the core back at each of the stator stages; and a rotor rotatably disposed at a position facing the claw poles of the stator, and: stator windings corresponding to a plurality of phases are disposed together at least at one of the two stator stages.Type: ApplicationFiled: August 22, 2008Publication date: April 23, 2009Applicant: Hitachi, Ltd.Inventors: Kenji Miyata, Yoshihisa Ishikawa, Motoya Ito, Yuji Enomoto, Takayuki Koyama
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Publication number: 20090001843Abstract: A rotating electrical machine includes: a claw pole stator constituted with a stator core that includes a plurality of claw poles and a stator coil wound inside the stator core; and a rotor rotatably disposed at a position facing opposite the claw poles. The stator core is constituted of split blocks each corresponding to at least one of magnetic pole pairs each made up with two claw poles assuming different magnetic polarities when an electric current is supplied to the stator coil.Type: ApplicationFiled: June 19, 2008Publication date: January 1, 2009Applicant: Hitachi, Ltd.Inventors: Yuji Enomoto, Yoshihisa Ishikawa, Motoya Ito, Hiroshi Kanazawa, Kenji Miyata, Takahiro Makiyama, Takayuki Koyama
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Publication number: 20080315702Abstract: An alternator for vehicle includes a stator that outputs an AC voltage and a rotor that includes a field coil and a rotor core. The stator includes a plurality of phase stators that are disposed side-by-side along the rotational axis and individually output AC voltages. The phase stators include an even number of stator tabs alternately extending from one outer side of a phase stator coil toward another outer side of the phase stator coil and extending from the other outer side toward the one outer side along the rotational axis. The rotor includes a field coil and a rotor core at which an even number of rotor tabs are formed along the circumferential direction so as to alternately extend from one outer side of the field coil toward another outer side of the field coil along the rotational axis and extend from the other outer side toward the one outer side along the rotational axis. A phase stator core at each phase stator is formed by laminating a plurality of magnetic sheets.Type: ApplicationFiled: June 18, 2008Publication date: December 25, 2008Applicant: Hitachi, Ltd.Inventors: Toshio Ishikawa, Minoru Yabuki, Yoshihisa Ishikawa, Yuji Enomoto
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Publication number: 20080315700Abstract: Stator claw poles are disposed at a stator core at a position facing opposite a rotor so as to alternately range from the two sides along the axial direction. With a plurality of magnetic poles thus formed, the distance by which the gap between the front end portions of the stator claw poles and the stator outer circumference ranges is increased, which, in turn, reduces the reactance guided to a stator coil. It is ensured that the magnetic reluctance manifesting between the front end portions of the stator claw poles and an enclosing member that holds the stator core, facing opposite the centers of the claw poles along the circumferential direction, is greater than the magnetic reluctance manifesting between the front portions and the stator core enclosing member facing opposite the front end portions.Type: ApplicationFiled: June 18, 2008Publication date: December 25, 2008Applicant: Hitachi, Ltd.Inventors: Toshio Ishikawa, Minoru Yabuki, Yoshihisa Ishikawa, Kazuo Tahara
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Publication number: 20080238237Abstract: An induction machine has a stator and rotor. The stator comprises teeth and slots and stator winding disposed in the slots. The rotor comprises a rotor core having teeth and slots and a rotor-conductor disposed in the rotor slots. Both of the stator core and rotor core are made of laminated steel sheets, and the teeth and slots made of steel sheets are formed by etching.Type: ApplicationFiled: February 6, 2008Publication date: October 2, 2008Inventors: Kazuo Nishihama, Teruyoshi Abe, Yoshihisa Ishikawa, Hiroyuki Mikami
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Publication number: 20080238241Abstract: An efficient and high-performance commutator motor in which both torque enhancement and iron loss reduction are achieved is provided by ensuring a sufficient area occupied by field windings wound on main poles and further suppressing the influence of armature counteractive magnetic flux and reducing pulsating torque. The commutator motor includes a stator and an armature. The stator includes a stator iron core having the main poles and slots and the field windings disposed in the slots. The armature includes an armature iron core having slots and teeth and armature windings wound in the slots. The stator and armature iron cores are formed of laminated steel sheets. The iron cores are formed by etching process. Multiple through holes are formed in the main poles opposed to the air gap positioned on the forward side in the direction of armature rotation by etching process.Type: ApplicationFiled: January 24, 2008Publication date: October 2, 2008Inventors: Tsukasa TANIGUCHI, Yoshihisa Ishikawa, Teruyoshi Abe
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Publication number: 20080224574Abstract: A stepping motor comprising: a stator iron core with a plurality of salient poles each having a small tooth at the tip thereof and stator coils each disposed between the salient poles; a rotor core with a plurality of teeth in the faces opposite to the stator; and permanent magnets sandwiched by the rotor cores in an axial direction, wherein the stator iron core and the rotor core are formed by laminated steel plates. The salient poles of the stator iron cores of the steel plates and small teeth are shaped by etching, and a thickness of the steel plates is 0.05 to 0.30 mm.Type: ApplicationFiled: January 24, 2008Publication date: September 18, 2008Inventors: Yuji Enomoto, Yoshihisa Ishikawa, Teruyoshi Abe
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Publication number: 20080136272Abstract: It is an object of the present invention to make it possible to easily wind a stator winding, enhance an occupied ratio in a stator core, reduce a winding resistance because there is no coil end, and change a field magnetic flux in accordance with a use. Stator pawl magnetic poles of a stator core extend from both sides in an axial direction alternately at locations opposed to a rotor to form a plurality of magnetic poles. With this stator core, it is only necessary to annularly wind a stator winding. Therefore, it is possible to enhance operability and an occupied ratio, and since there is no coil end, it is possible to reduce winding resistance. Since the rotor is a Randall type rotor having a field winding and a rotor pawl magnetic pole, it is possible to change the field magnetic flux in accordance with a use.Type: ApplicationFiled: December 5, 2007Publication date: June 12, 2008Inventors: Toshio Ishikawa, Minoru Yabuki, Hiroshi Kanazawa, Yuji Enomoto, Yoshihisa Ishikawa
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Publication number: 20080136285Abstract: The spindle motor has a stator and rotor. The stator has a stator core comprising a yoke and salient poles and also includes a stator coil. The stator core is formed by laminated steel sheets. The salient poles made of the steel sheets are formed by etching. The steel sheet is 0.05 to 0.30 mm thick. The steel sheet used in the present invention is preferably a silicon steel sheet having crystal particles. The iron loss and cogging torque of the inventive spindle motor are reduced.Type: ApplicationFiled: December 7, 2007Publication date: June 12, 2008Inventors: Fumio Tajima, Teruyoshi Abe, Motoya Ito, Yoshihisa Ishikawa, Masashi Kitamura, Toshuyuki Ajima
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Publication number: 20080012445Abstract: A rotating electrical machine comprises a stator and a rotor; the stator comprising a stator core having teeth and slots, and stator windings disposed in the slots, wherein the stator core is made of laminated steel sheets, teeth and slots of the steel sheet are made by etching, and the thickness of the steel sheet is between 0.05 mm and 0.30 mm. Specifically, it is preferable that the steel sheet used herein be a silicon steel sheet containing crystalline particles.Type: ApplicationFiled: July 12, 2007Publication date: January 17, 2008Inventors: TERUYOSHI ABE, Motoya Ito, Fumio Tajima, Yoshihisa Ishikawa
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Patent number: 5537271Abstract: An apparatus comprises first and second levers supported to be rotatable on a holder which holds a disc cartridge. The first lever has one end provided with a abutting pin which abuts the shutter to open the window of the cartridge, and other end connected to a shutter-closing spring to rotate the first lever to close the window and eject the cartridge from the holder. The second lever has one end coupled to the shutter-closing spring and other end provided with a push pin and connected to a break spring to make the push pin apply a force to the side of the cartridge. When the cartridge is inserted into the holder, the shutter-closing spring decreases the bias of the brake spring whereby decreasing the force with which the push pin pushes the side of the cartridge.Type: GrantFiled: December 22, 1993Date of Patent: July 16, 1996Assignee: Olympus Optical Co., Ltd.Inventors: Katsunori Kumai, Toshikazu Hayashi, Hiroshi Kodama, Yoshihisa Ishikawa
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Patent number: 4346159Abstract: A photosensitive element for electrophotography comprising an electrically conductive backing member, a photoconductive layer overlying the backing member, and a transparent electrically insulating surface layer on the photoconductive layer, wherein the transparent electrically insulating surface layer contains a charge-retentive material or a layer of a charge-retentive material is interposed between the photoconductive layer and the transparent electrically insulating surface layer so as to form a charge-retentive layer in the boundary between the photoconductive layer and the transparent electrically insulating layer.Type: GrantFiled: February 14, 1978Date of Patent: August 24, 1982Assignee: Fuji Xerox Co., Ltd.Inventors: Shigeru Sadamatsu, Lyon S. Pu, Yoshihisa Ishikawa
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Patent number: D583504Type: GrantFiled: January 23, 2008Date of Patent: December 23, 2008Assignee: Omron CorporationInventors: Toshimitsu Fujiwara, Atsushi Sawada, Isao Kobayashi, Yoshihisa Ishikawa
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Patent number: D621992Type: GrantFiled: October 12, 2007Date of Patent: August 17, 2010Assignee: OMRON CorporationInventors: Toshimitsu Fujiwara, Tomonobu Kato, Yoshihisa Ishikawa, Kosuke Sanari