Patents by Inventor Kazunari Usui

Kazunari Usui 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).

  • Track pitch variation measurement method using spiral DC pattern writing
    Patent number: 8861116
    Abstract: In one embodiment, a method includes spiral writing a DC pattern onto a magnetic disk medium using a writer of a magnetic head while moving the magnetic head in a direction about parallel to a radial direction of the magnetic disk medium while rotating the magnetic disk medium, reading the magnetic disk medium while moving the magnetic head in the direction about parallel to the radial direction of the magnetic disk medium while rotating the magnetic disk medium, and calculating a track pitch interval between data tracks of the magnetic disk medium based on the reading of the magnetic disk medium. In another embodiment, a magnetic disk medium includes a DC spiral pattern in a radial region further outward and/or a radial region further inward than a radial region where data is recorded.
    Type: Grant
    Filed: August 2, 2011
    Date of Patent: October 14, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Mao Nishiyama, Masafumi Mochizuki, Kyo Akagi, Shuji Nishida, Kazunari Usui
  • TRACK PITCH VARIATION MEASUREMENT METHOD USING SPIRAL DC PATTERN WRITING
    Publication number: 20130033778
    Abstract: In one embodiment, a method includes spiral writing a DC pattern onto a magnetic disk medium using a writer of a magnetic head while moving the magnetic head in a direction about parallel to a radial direction of the magnetic disk medium while rotating the magnetic disk medium, reading the magnetic disk medium while moving the magnetic head in the direction about parallel to the radial direction of the magnetic disk medium while rotating the magnetic disk medium, and calculating a track pitch interval between data tracks of the magnetic disk medium based on the reading of the magnetic disk medium. In another embodiment, a magnetic disk medium includes a DC spiral pattern in a radial region further outward and/or a radial region further inward than a radial region where data is recorded.
    Type: Application
    Filed: August 2, 2011
    Publication date: February 7, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Mao Nishiyama, Masafumi Mochizuki, Kyo Akagi, Shuji Nishida, Kazunari Usui