Patents by Inventor Tetsunori Kouda

Tetsunori Kouda 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: 6846583
    Abstract: A magnetic recording medium comprises a magnetic recording layer 63 which is formed by using an ordered alloy containing B on a substrate 1 containing an amorphous component. A part of B in the ordered alloy is segregated in a grain boundary, and thus the magnetic interaction, which acts between magnetic grains, can be reduced. Accordingly, it is possible to form fine and minute magnetic domains in the magnetic recording layer 63, and it is possible to reduce the medium noise as well. The temperature, at which the substrate is heated during the film formation of the magnetic recording layer 63, can be suppressed to be low, because the ordering temperature for the ordered alloy containing B is lower than those of ordered alloys not containing B. Therefore, it is possible to use a substrate made of glass which is suitable for the mass production. The magnetic recording layer 63 is also excellent in thermal stability because of the use of the ordered alloy having high magnetic anisotropy.
    Type: Grant
    Filed: February 3, 2003
    Date of Patent: January 25, 2005
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Nobuyuki Inaba, Tetsunori Kouda, Hideaki Yamanaka, Satoshi Matsunuma, Enji Fujita
  • Publication number: 20030215675
    Abstract: A magnetic recording medium comprises a magnetic recording layer 63 which is formed by using an ordered alloy containing B on a substrate 1 containing an amorphous component. A part of B in the ordered alloy is segregated in a grain boundary, and thus the magnetic interaction, which acts between magnetic grains, can be reduced. Accordingly, it is possible to form fine and minute magnetic domains in the magnetic recording layer 63, and it is possible to reduce the medium noise as well. The temperature, at which the substrate is heated during the film formation of the magnetic recording layer 63, can be suppressed to be low, because the ordering temperature for the ordered alloy containing B is lower than those of ordered alloys not containing B. Therefore, it is possible to use a substrate made of glass which is suitable for the mass production. The magnetic recording layer 63 is also excellent in thermal stability because of the use of the ordered alloy having high magnetic anisotropy.
    Type: Application
    Filed: February 3, 2003
    Publication date: November 20, 2003
    Applicant: Hitachi Maxell, Ltd.
    Inventors: Nobuyuki Inaba, Tetsunori Kouda, Hideaki Yamanaka, Satoshi Matsunuma, Enji Fujita