Patents by Inventor Atushi Yamamoto

Atushi Yamamoto 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: 7268536
    Abstract: A magnetic linear position sensor comprises a first yoke which is made of soft magnetic material; a first magnet which is placed at the first yoke, and whose surface is the N-pole and is inclined; a second magnet which is placed at the first yoke, and whose surface is the S-pole and is inclined in a direction opposite to the surface of the first magnet and in a direction facing the surface of the first magnet; a second yoke which is placed at a position opposing the first magnet and the second magnet through an air gap and is made of soft magnetic material; and a magnetoelectric transducer which is placed in the air gap.
    Type: Grant
    Filed: January 6, 2005
    Date of Patent: September 11, 2007
    Assignee: Japan Servo Co., Ltd.
    Inventors: Hiroshi Hagino, Atushi Yamamoto, Takanobu Igarashi, Masahiro Horiguchi
  • Patent number: 7023202
    Abstract: The invention relates to a magnetic rotary position sensor that detects the absolute position of a rotation angle as an electric output in a non-contact state with magneto-electric transducers for converting a magnetic flux variation into a voltage. The magnetic rotary position sensor of the invention includes a cylindrical yoke, semi-cylindrical first and second magnets, and magneto-electric transducers. Here, the first and second magnets are disposed on the inside of the yoke to face to each other, and are magnetized in a manner that the N-pole and S-pole face to each other.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: April 4, 2006
    Assignee: Japan Servo Co., Ltd.
    Inventors: Hiroshi Hagino, Atushi Yamamoto, Takanobu Igarashi, Masahiro Horiguchi
  • Publication number: 20050151535
    Abstract: A magnetic linear position sensor comprises a first yoke which is made of soft magnetic material; a first magnet which is placed at the first yoke, and whose surface is the N-pole and is inclined; a second magnet which is placed at the first yoke, and whose surface is the S-pole and is inclined in a direction opposite to the surface of the first magnet and in a direction facing the surface of the first magnet; a second yoke which is placed at a position opposing the first magnet and the second magnet through an air gap and is made of soft magnetic material; and a magnetoelectric transducer which is placed in the air gap.
    Type: Application
    Filed: January 6, 2005
    Publication date: July 14, 2005
    Inventors: Hiroshi Hagino, Atushi Yamamoto, Takanobu Igarashi, Masahiro Horiguchi
  • Publication number: 20050024045
    Abstract: The invention relates to a magnetic rotary position sensor that detects the absolute position of a rotation angle as an electric output in a non-contact state with magneto-electric transducers for converting a magnetic flux variation into a voltage. The magnetic rotary position sensor of the invention includes a cylindrical yoke, semi-cylindrical first and second magnets, and magneto-electric transducers. Here, the first and second magnets are disposed on the inside of the yoke to face to each other, and are magnetized in a manner that the N-pole and S-pole face to each other.
    Type: Application
    Filed: July 29, 2004
    Publication date: February 3, 2005
    Inventors: Hiroshi Hagino, Atushi Yamamoto, Takanobu Igarashi, Masahiro Horiguchi
  • Patent number: 6552453
    Abstract: The magnetic pole position detector for an electric motor comprises a detection rotor, a detection stator, and magnetic flux concentration tips and magneto electro transducers. The detection rotor is fixed to an axis of rotation of the motor and comprised of disc-like rotors having first toothlike protrusions and a permanent magnet. The disc-like rotors are assembled so as to make the first toothlike protrusions coincide in the axial direction and the permanent magnet is fixed between the disc-like rotors. The detection stator is comprised of stator cores comprised of an annular yoke and stator teeth formed at regular intervals on the former. Second toothlike protrusions are formed on the inner end of the stator teeth. The stator cores are assembled with a gap in the axial direction so as to make respective second toothlike protrusions coincide in the axial direction. The magnetic flux concentration tips and the magneto electro transducers are placed in the gaps in the axial direction.
    Type: Grant
    Filed: May 22, 2001
    Date of Patent: April 22, 2003
    Assignee: Japan Servo Co., Ltd.
    Inventors: Shoji Ohiwa, Kazuo Ohnishi, Atushi Yamamoto, Shinji Shimizu, Youji Unoki, Yukinori Kurita
  • Publication number: 20020047348
    Abstract: The magnetic pole position detector for an electric motor comprises a detection rotor, a detection stator, and magnetic flux concentration tips and magneto electro transducers. The detection rotor is fixed to an axis of rotation of the motor and comprised of disc-like rotors having first toothlike protrusions and a permanent magnet. The disc-like rotors are assembled so as to make the first toothlike protrusions coincide in the axial direction and the permanent magnet is fixed between the disc-like rotors. The detection stator is comprised of stator cores comprised of an annular yoke and stator teeth formed at regular intervals on the former. Second toothlike protrusions are formed on the inner end of the stator teeth. The stator cores are assembled with a gap in the axial direction so as to make respective second toothlike protrusions coincide in the axial direction. The magnetic flux concentration tips and the magneto electro transducers are placed in the gaps in the axial direction.
    Type: Application
    Filed: May 22, 2001
    Publication date: April 25, 2002
    Inventors: Shoji Ohiwa, Kazuo Ohnishi, Atushi Yamamoto, Shinji Shimizu, Youji Unoki, Yukinori Kurita