Patents by Inventor Noriyoshi Takahashi

Noriyoshi Takahashi 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).

  • Patent number: 5262262
    Abstract: An electrophotographic photoreceptor having excellent dark resistance is disclosed, which comprises a photoconductive layer and a surface layer formed successively on a conductive substrate, wherein the photoconductive layer mainly comprises hydrogen-containing amorphous silicon, and the surface layer comprises amorphous carbon which contains not more than 50 atomic percent of hydrogen.
    Type: Grant
    Filed: September 30, 1991
    Date of Patent: November 16, 1993
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Shigeru Yagi, Masayuki Nishikawa, Te Nam Roh, Ken-ichi Karakida, Masahito Tokuhiro, Yuzuru Fukuda, Noriyoshi Takahashi
  • Patent number: 5139911
    Abstract: An electrophotographic photoreceptor comprising a conductive support having thereon an amorphous silicon photoconductive layer and a surface protective layer is disclosed, the surface protective layer having a laminated structure comprised of a lower layer comprising nitrogen-containing amorphous silicon and an upper layer comprising amorphous carbon.The photoreceptor causes no image deletion even after repeated use under a high temperature and high humidity condition and exhibits excellent scratch resistance.
    Type: Grant
    Filed: December 28, 1989
    Date of Patent: August 18, 1992
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Shigeru Yagi, Masato Ono, Noriyoshi Takahashi, Masayuki Nishikawa, Yuzuru Fukuda, Kenichi Karakida
  • Patent number: 5094929
    Abstract: An electrophotographic photoreceptor having a light-sensitive layer formed on an electrically conductive substrate is disclosed, which contains at least a layer chiefly made of a germanium-containing amorphous carbon as a light-sensitive layer or an anti-reflection layer.
    Type: Grant
    Filed: December 29, 1989
    Date of Patent: March 10, 1992
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Shigeru Yagi, Masato Ono, Noriyoshi Takahashi, Masayuki Nishikawa, Yuzuru Fukuda, Ken-ichi Karakida
  • Patent number: 5089737
    Abstract: A novel DC rotary electric machine of permanent magnet field type is disclosed, in which a plurality of permanent field magnets having an auxiliary pole of magnetic material are arranged alternately with a plurality of field magnets including only a magnetic material along the peripheral direction. The field magnets with the auxiliary poles are arranged adjacently with the field magnets of magnetic material with through bolts extending therebetween.
    Type: Grant
    Filed: April 24, 1989
    Date of Patent: February 18, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Toshimi Abukawa, Kazuo Tahara, Noriyoshi Takahashi, Toshio Tomite
  • Patent number: 5059501
    Abstract: An electrophotographic photoreceptor having a photosensitive layer essentially made of amorphous silicon formed over a support, and a surface layer made of amorphous silicon formed over the photosensitive layer. The amorphous silicon of the photosensitive layer includes boron of 0.1-5 ppm, and the amorphous silicon of the surface layer includes nitrogen. The layers of material formed over the support include a charge blocking layer.
    Type: Grant
    Filed: October 10, 1989
    Date of Patent: October 22, 1991
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Shigeru Yagi, Masato Ono, Noriyoshi Takahashi, Masayuki Nishikawa, Yuzuru Fukuda, Kenichi Karakida
  • Patent number: 5008170
    Abstract: A photoreceptor for electrophotography, comprising: a photoconductive layer substantially composed of amorphous silicon, and first, second and third surface layers substantially composed of amorphous silicon added with nitrogen atom, those layers being formed on a support. The thickness d.sub.1, d.sub.2 and d.sub.3 of the first, second and third surface layers satisfies the following relation: d.sub.2 >d.sub.1 and d.sub.2 >d.sub.3, and the nitrogen concentrations c.sub.1, c.sub.2 and c.sub.3 of said first, second and third surface layers satisfy the following relation: c.sub.3 >c.sub.2 >c.sub.1.
    Type: Grant
    Filed: June 23, 1989
    Date of Patent: April 16, 1991
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kenichi Karakida, Shigeru Yagi, Yuzuru Fukuda, Masayuki Nishikawa, Te N. Roh, Noriyoshi Takahashi, Masato Ono, Masaki Yokoi, Yumiko Komori
  • Patent number: 4965154
    Abstract: An electrophotographic photoreceptor comprising a photoconductive layer, a first surface layer and a second surface layer formed in sequence on a support, said photoconductive layer being substantially composed of amorphous silicon, and each of said first and second surface layers being substantially composed of nitrogen-doped amorphous silicon, the concentration of nitrogen atoms in the second surface layer being higher than that in the first surface layer. The photoconductive layer is doped with atoms of an element of group III, or in at least a part of the photoconductive layer doped with germanium atoms in place of the element of group III.
    Type: Grant
    Filed: June 19, 1989
    Date of Patent: October 23, 1990
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kenichi Karakida, Shigeru Yagi, Yuzuru Fukuda, Masayuki Nishikawa, Te Nam Roh, Noriyoshi Takahashi, Masato Ono
  • Patent number: 4960662
    Abstract: A positively and negatively chargeable electrophotographic photoreceptor is disclosed, comprising a substrate having thereon a charge blocking layer, an amorphous silicon photoconductive layer, and an amorphous silicon nitride surface layer provided in that order, wherein the charge blocking layer comprises of amorphous silicon nitride and the amorphous silicon photoconductive layer comprises of an i-type amorphous silicon containing 0.05 to 5.0 ppm of boron.
    Type: Grant
    Filed: January 5, 1989
    Date of Patent: October 2, 1990
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Masayuki Nishikawa, Yumiko Komori, Masaki Yokoi, Masato Ono, Noriyoshi Takahashi, Yuzuru Fukuda, Shigeru Yagi, Ken-ichi Karakida
  • Patent number: 4959575
    Abstract: Disclosed is a bar or conductor constituted by a plurality of strands disposed in a slot and extending outward from the opposite ends of the slot with each of the strands being substantially bisymmetrically vertically slanted so as to be transposed in the vicinity of a longitudinally central portion of the slot-inside bar portion. Each of the strands being transposed such that the respective strand arrangements at the opposite ends of the slot-outside bar end portions are reversed with respect to each other, with the total number of transposed portions of all the strands is less than three times the number of the strands.
    Type: Grant
    Filed: July 10, 1989
    Date of Patent: September 25, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Toshio Saitoh, Noriyoshi Takahashi, Masaki Satoh
  • Patent number: 4932859
    Abstract: An electrophotographic photoreceptor having excellent dark resistance is disclosed, which comprises a photoconductive layer and a surface layer formed successively on a conductive substrate, wherein the photoconductive layer mainly comprises hydrogen-containing amorphous silicon, and the surface layer comprises amorphous carbon which contains not more than 50 atomic percent of hydrogen. The surface layer contains phosphorous or boron as a dopant and/or comprises two sublayers where the sublayer has a lower hydrogen content than the lower sublayer.
    Type: Grant
    Filed: July 5, 1988
    Date of Patent: June 12, 1990
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Shigeru Yagi, Masayuki Nishikawa, Te Nam Roh, Ken-ichi Karakida, Masahito Tokuhiro, Noriyoshi Takahashi, Yuzuru Fukuda
  • Patent number: 4923773
    Abstract: An electrophotographic photoreceptor comprising a support, a charge blocking layer, a first photoconductive layer composed of at least amorphous silicon, a second photoconductive layer composed of at least boron-containing amorphous silicon, a surface layer composed of at least nitrogenated amorphous silicon, the surface layer having an interface for contacting the second photoconductive layer, the surface layer including a lower region corresponding to an area not greater than approximately 100 .ANG. away from the interface, the lower region having a ratio of not less than 0.5 parts of nitrogen atoms for one part of silicon atoms, the nitrogen ratio of the lower region and the boron content of the second photoconductive layer corresponding to the relation B.gtoreq.10.sup.(9N-5.5) where B is the boron content in PPM and N is the ratio of nitrogen atoms to silicon atoms.
    Type: Grant
    Filed: October 18, 1988
    Date of Patent: May 8, 1990
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Shigeru Yagi, Masato Ono, Noriyoshi Takahashi, Masayuki Nishikawa, Yuzuru Fukuda, Kenichi Karakida
  • Patent number: 4823037
    Abstract: A DC electric motor which comprises: a reversibly rotatable rotor having an armature core, an armature winding and a commutator; a stator having a yoke and a plurality of field poles provided on an inner circumference of the yoke and each having a permanent magnet and an auxiliary pole; and brush means including a plurality of brushes arranged to be slidably electrically conductively in contact with the commutator; in which the auxiliary pole of each of the field poles is disposed at an exit side of the field pole in the normal foward rotating direction of the rotor; each of the brushes is held movably between a first position corresponding to a position near a geometrically neutral point between a pair of adjacent field poles and a second position corresponding to a position separated at the maximum by an electrical angle of 90 degrees from the geometrically neutral point reversely to the normal rotating direction, and each of the brushes is fixed in the vicinity of the second position in normal use.
    Type: Grant
    Filed: October 28, 1987
    Date of Patent: April 18, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Toshimi Abukawa, Kazuo Tahara, Noriyoshi Takahashi, Toshio Tomite
  • Patent number: 4794291
    Abstract: A permanent magnet field DC machine comprises a rotor and a stator. The rotor comprises an armature core (3), an armature winding (4), and a commutator (2). The stator comprises a yoke (7), permanent magnets (8) disposed on the inner periphery of the yoke (7), and magnetic pole pieces (9) interposed between the yoke (7) and a portion of each magnetic pole (8). The magnetic pole pieces (8) are made of a material the permeability of which is greater than that of the permanent magnets.
    Type: Grant
    Filed: March 16, 1987
    Date of Patent: December 27, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Toshimi Abukawa, Kazuo Tahara, Noriyoshi Takahashi, Toshio Tomite
  • Patent number: 4777396
    Abstract: A rotor of induction motor comprises a rotary shaft, a cylindrical rotor core fixedly secured on the rotary shaft, a conductive cover fixed on the outer circumferential surface of the rotor core, the conductive cover being formed of a composite material of magnetic material and electrically highly conductive material to have a circumferential permeability smaller than a radial permeability, and a magnetic skin made of a magnetic material and provided on the outer circumferential surface of the conductive cover, the magnetic skin having a circumferential permeability and an electrical conductivity which are set to be larger than the circumferential permeability and an electrical resistivity of the conductive cover, respectively, whereby a loss due to a spatial higher harmonics magnetic flux of higher order generated by a pulsating magnetic flux of slots in a stator of induction motor can be prevented.
    Type: Grant
    Filed: October 23, 1987
    Date of Patent: October 11, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Motoya Ito, Keiji Arai, Noriyoshi Takahashi, Noboru Fujimoto, Yoshitaka Kojima
  • Patent number: 4704789
    Abstract: Disclosed is a method of manufacturing an electromagnetic member having properties of magnetic anisotropy as well as electrical conductivity, comprising the steps of coating an outer circumferential surface of each of a plurality of magnetic strips with a first electrically conductive material to a predetermined thickness to thereby form a plurality of composite magnetic strips, binding the plurality of composite magnetic strips, and filling spaces among the plurality of composite magnetic strips in the bundle with a second electrically conductive material substantially the same as the first electrically conductive material. By this method, a mechanically strong electromagnetic member can be obtained in which adjusting the thickness of the first electrically conductive material, the ratio between the magnetic property and the electrically conductive property can be easily adjusted by adjusting the thickness of the first electrically conductive material and blow-holes can be prevented from being generated.
    Type: Grant
    Filed: February 26, 1986
    Date of Patent: November 10, 1987
    Assignees: Hitachi, Ltd., Hitachi Cable, Ltd.
    Inventors: Motoya Ito, Noriyoshi Takahashi, Masatoshi Watanabe, Toshimi Abukawa, Takeshi Seya, Hiroshi Kainuma, Toshiyuki Syutoo
  • Patent number: 4703210
    Abstract: A miniature electric rotating machine has a stator equipped with a field pole on a peripheral circle of a rotor, and the field pole is constituted by a permanent magnet. Each permanent magnet of a miniature electric rotating machine of this type can be divided into a magnetizing side and a demagnetizing side with respect to armature reaction. In the permanent magnet of the present invention, an end portion on the demagnetizing side, which has directivity different from the magnetizing directions on the magnetizing and demagnetizing sides, is disposed adjacent to the portion on the demagnetizing side.
    Type: Grant
    Filed: September 9, 1986
    Date of Patent: October 27, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Toshimi Abukawa, Kazuo Tahara, Noriyoshi Takahashi, Toshio Tomite
  • Patent number: 4657818
    Abstract: A sliding current collector comprises a pair of sliding members which are slidable relative to each other for supply and reception of current through sliding surfaces of the paired sliding members wherein the two sliding members are made of conductive ceramics, and the sliding surface of each of the sliding members has a film surface made of a soft conductive material which is softer than the conductive ceramics so that the sliding current collector can suppress variations in contact voltage drop across the sliding surfaces.
    Type: Grant
    Filed: June 13, 1985
    Date of Patent: April 14, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Nobuyuki Yamashita, Kazuo Tahara, Masatoshi Watanabe, Noriyoshi Takahashi
  • Patent number: 4639625
    Abstract: A direct-current machine having a rotor which includes a commutator, an armature core and an armature winding and is sustained rotatably in a field system constituted by a cylindrical housing and permanent magnets disposed inside the same. A demagnetizing force of an armature reaction due to an armature current is reduced by attaching a magnetic plate made of high saturation magnetic flux density material to a part of the pole-face of said field system of permanent magnets which is in the demagnetizing field.
    Type: Grant
    Filed: August 22, 1985
    Date of Patent: January 27, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Toshimi Abukawa, Kazuo Tahara, Noriyoshi Takahashi, Fumio Tajima, Tosio Tomite
  • Patent number: 4633115
    Abstract: An apparatus for connecting conductor strands with transposition in an electrical rotary machine is disclosed to include a plurality of electrically conductive connector rods respectively connected to ends of the individual strands of each conductor, and a plurality of electrically conductive plates arrayed in the axial direction of the conductive connector rods and adapted to mutually connect respective pairs of strands of the multiple strand conductors through the corresponding conductive rods while electrically insulating one strand pair from other strand pairs.
    Type: Grant
    Filed: March 7, 1985
    Date of Patent: December 30, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Toshio Saitoh, Noriyoshi Takahashi, Masaki Sato, Masatoshi Watanabe
  • Patent number: 4562397
    Abstract: A squirrel-cage induction motor comprises a stator having a stator core and stator windings divided into first and second coils with different numbers of poles, and a squirrel-cage rotor including a rotor core and a plurality of rotor conductors embedded in the vicinity of the surface of the core. The number of the rotor conductors is the same as the average number of poles of the first and second stator coils, which conductors are arranged equidistantly along the periphery. This induction motor, with the construction of a squirrel-cage rotor, permits a variable speed operation without using any special device.
    Type: Grant
    Filed: July 26, 1984
    Date of Patent: December 31, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Yukio Kitabayashi, Noriyoshi Takahashi, Toshiaki Okuyama, Masatoshi Watanabe, Hitoshi Ohura