Patents by Inventor Michiya Kazusawa

Michiya Kazusawa 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: 10283159
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Grant
    Filed: June 8, 2018
    Date of Patent: May 7, 2019
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Satoshi Tabata, Atsushi Yamada, Michiya Kazusawa, Masato Shiimoto
  • Publication number: 20180294010
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Application
    Filed: June 8, 2018
    Publication date: October 11, 2018
    Inventors: SATOSHI TABATA, Atsushi Yamada, MICHIYA KAZUSAWA, Masato Shiimoto
  • Patent number: 10020020
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Grant
    Filed: October 19, 2017
    Date of Patent: July 10, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Satoshi Tabata, Atsushi Yamada, Michiya Kazusawa, Masato Shiimoto
  • Publication number: 20180061450
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Application
    Filed: October 19, 2017
    Publication date: March 1, 2018
    Inventors: SATOSHI TABATA, Atsushi Yamada, MICHIYA KAZUSAWA, Masato Shiimoto
  • Patent number: 9799369
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Grant
    Filed: November 24, 2015
    Date of Patent: October 24, 2017
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Satoshi Tabata, Atsushi Yamada, Michiya Kazusawa, Masato Shiimoto
  • Publication number: 20170148471
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Application
    Filed: November 24, 2015
    Publication date: May 25, 2017
    Inventors: Satoshi Tabata, Atsushi Yamada, Michiya Kazusawa, Masato Shiimoto
  • Patent number: 9070397
    Abstract: A data storage device and method for improved flying height control (TFC) in a HAMR or MAMR system employing three heat sources to control the head protrusion: write coil current, TFC heater current, and media exciter power. The TFC heater is used to pre-heat the write head. The media exciter may be operated at a either a zero level or a low level below that required for the HAMR or MAMR process, optionally serving as an additional source of heat to the write head. The HAMR or MAMR data writing process commences only after the head protrusion has been increased and stabilized. During data writing, the media exciter power is increased to the higher level required to heat the disk medium in an HAMR or MAMR process and the TFC heater power is slightly reduced to maintain the total heat into the head approximately constant.
    Type: Grant
    Filed: May 8, 2014
    Date of Patent: June 30, 2015
    Assignee: HGST NETHERLANDS B.V.
    Inventors: Naoto Ito, Jun Hashimoto, Erhard Schreck, Michiya Kazusawa
  • Publication number: 20150138937
    Abstract: A method of storing data includes providing a write signal for a write head of a hard disk drive, generating a transition pulse signal derived from the write signal using a transition pulse generator, and generating a logic signal to drive a thermal source associated with the write head of the hard disk drive. The logic signal includes the logical summation of a cyclical base pulse signal and the transition pulse signal.
    Type: Application
    Filed: November 15, 2013
    Publication date: May 21, 2015
    Applicant: HGST Netherlands B.V.
    Inventors: Naoto Ito, Michiya Kazusawa, Hiroyasu Tanabe, Sarbanoo Das, Hideki Zaitsu
  • Patent number: 9025420
    Abstract: A method of storing data includes providing a write signal for a write head of a hard disk drive, generating a transition pulse signal derived from the write signal using a transition pulse generator, and generating a logic signal to drive a thermal source associated with the write head of the hard disk drive. The logic signal includes the logical summation of a cyclical base pulse signal and the transition pulse signal.
    Type: Grant
    Filed: November 15, 2013
    Date of Patent: May 5, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Naoto Ito, Michiya Kazusawa, Hiroyasu Tanabe, Sarbanoo Das, Hideki Zaitsu
  • Patent number: 8259406
    Abstract: A disk drive including a sensor element that senses contact between a head slider and a disk, a head integrated circuit (IC) comprising an amplification circuit section that amplifies a signal of the head slider, a controller IC comprising a controller that accesses a register of the head IC for controlling the head IC, and an identification section, within the head IC, that determines a contact frequency of the contact by the sensor element by using a timing control signal of the controller IC.
    Type: Grant
    Filed: December 9, 2010
    Date of Patent: September 4, 2012
    Assignee: Hitachi Global Storage Technologies, Netherlands B.V.
    Inventors: Michiya Kazusawa, Masayuki Kurita, Kenji Kuroki, Yoshihiko Maeda
  • Publication number: 20110141603
    Abstract: A disk drive including a sensor element that senses contact between a head slider and a disk, a head integrated circuit (IC) comprising an amplification circuit section that amplifies a signal of the head slider, a controller IC comprising a controller that accesses a register of the head IC for controlling the head IC, and an identification section, within the head IC, that determines a contact frequency of the contact by the sensor element by using a timing control signal of the controller IC.
    Type: Application
    Filed: December 9, 2010
    Publication date: June 16, 2011
    Inventors: Michiya KAZUSAWA, Masayuki Kurita, Kenji Kuroki, Yoshihiko Maeda
  • Patent number: 7038870
    Abstract: A data storage device, data write method, and program to avoid extra power consumption and suppress a write error that may result from voltage variations. To write data onto a magnetic disk, a write circuit generates a write current that is to be supplied to a write head. The write circuit operates on a positive power supply voltage provided by a host computer, and on a negative power supply voltage generated by a programmable DC—DC converter mounted on a hard disk drive's card. The magnitude of the negative power supply voltage generated by the programmable DC—DC converter is varied in accordance with the temperature surrounding the magnetic disk. Further, the magnitude of the negative power supply voltage generated by the programmable DC—DC converter is varied in accordance with the magnitude of the positive power supply voltage supplied from the host computer.
    Type: Grant
    Filed: October 22, 2003
    Date of Patent: May 2, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroaki Suzuki, Noriaki Sato, Michiya Kazusawa, Hideo Asano
  • Publication number: 20040212910
    Abstract: A data storage device, data write method, and program to avoid extra power consumption and suppress a write error that may result from voltage variations. To write data onto a magnetic disk, a write circuit generates a write current that is to be supplied to a write head. The write circuit operates on a positive power supply voltage provided by a host computer, and on a negative power supply voltage generated by a programmable DC-DC converter mounted on a hard disk drive's card. The magnitude of the negative power supply voltage generated by the programmable DC-DC converter is varied in accordance with the temperature surrounding the magnetic disk. Further, the magnitude of the negative power supply voltage generated by the programmable DC-DC converter is varied in accordance with the magnitude of the positive power supply voltage supplied from the host computer.
    Type: Application
    Filed: October 22, 2003
    Publication date: October 28, 2004
    Applicant: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Hiroaki Suzuki, Noriaki Sato, Michiya Kazusawa, Hideo Asano