Patents by Inventor Noriyuki Asakura

Noriyuki Asakura 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).

  • Publication number: 20090242389
    Abstract: A method for manufacturing a magnetic recording medium including a nonmagnetic substrate, an intermediate layer over the nonmagnetic substrate, and a granular magnetic layer for recording information, disposed on the intermediate layer. The method includes sputtering a Co alloy, a Ti oxide, a Si oxide and a Co oxide simultaneously to form the granular magnetic layer containing Co alloy magnetic particles and an oxide magnetically separating the magnetic particles.
    Type: Application
    Filed: March 23, 2009
    Publication date: October 1, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Noriyuki Asakura, Hideaki Takahoshi, Jun Taguchi, Isatake Kaitsu, Akira Kikuchi
  • Publication number: 20080204937
    Abstract: This magnetic recording medium comprising at least a non-magnetic underlayer on a non-magnetic substrate, a first recording magnetic layer on the non-magnetic underlayer, a second recording magnetic layer on the first recording magnetic layer, and a third recording magnetic layer on the second recording magnetic layer. The first recording magnetic layer, the second recording magnetic layer and the third recording magnetic layer are made of a CoCrPtB alloy. The second recording magnetic layer has a smaller Cr content and a greater B content than the first recording magnetic layer, and the third recording magnetic layer has a smaller Cr content and a greater B content than the first recording magnetic layer and a smaller Pt content than the second recording magnetic layer. The magnetic recording medium according to the present invention can obtain high output medium characteristic with low noise and excellent written performance.
    Type: Application
    Filed: December 18, 2007
    Publication date: August 28, 2008
    Applicant: Fujitsu limited
    Inventors: Yuuki Yoshida, Jun Taguchi, Kazuhisa Shida, Noriyuki Asakura, Akira Kikuchi
  • Publication number: 20080131736
    Abstract: A longitudinal magnetic recording medium includes, in order from a nonmagnetic substrate, a primary coat layer that contains Cr, an intermediate layer, a magnetic layer as a recording layer made of CoCr alloy, and a protective layer, the intermediate layer including a RuCr intermediate layer made of a RuCr alloy that contains 10 to 50 at % of Cr.
    Type: Application
    Filed: September 17, 2007
    Publication date: June 5, 2008
    Applicant: Fujitsu Limited
    Inventors: Kazuhisa Shida, Yuki Yoshida, Jun Taguchi, Noriyuki Asakura, Akira Kikuchi
  • Publication number: 20080096054
    Abstract: A magnetic recording medium includes a substrate having a surface where a texture is formed along a recording direction; a first underlayer formed on the surface of the substrate and made of Cr or CrMn; a second underlayer formed on the first underlayer and made of CrMn; a third underlayer formed on the second underlayer and made of Cr—X1 alloy wherein X1 includes a material selected from the group consisting of Mo, Ti, W, V, Ta, and Nb; and a recording layer formed on the third underlayer and made of a ferromagnetic material whose main ingredient is Co; wherein content of Mn of the second underlayer is greater than content of Mn of the first underlayer if the first underlayer is made of CrMn; and a total of film thicknesses of the first underlayer and the second underlayer is in a range between 2 nm and 7 nm.
    Type: Application
    Filed: February 9, 2007
    Publication date: April 24, 2008
    Inventors: Jun Taguchi, Yuki Yoshida, Kazuhisa Shida, Noriyuki Asakura, Akira Kikuchi
  • Publication number: 20080081218
    Abstract: A magnetic recording medium includes a substrate, an underlayer of a chromium alloy formed on the substrate, a ferromagnetic layer formed on the underlayer, a spacer layer formed on the ferromagnetic layer, and a recording layer of a cobalt-chromium alloy formed on the spacer layer. The spacer layer is formed with a ruthenium-cobalt-based alloy.
    Type: Application
    Filed: April 24, 2007
    Publication date: April 3, 2008
    Applicant: Fujitsu Limited
    Inventors: Kazuhisa Shida, Yuki Yoshida, Jun Taguchi, Noriyuki Asakura, Akira Kikuchi
  • Patent number: 7273666
    Abstract: A magnetic recording medium and a magnetic recording medium driving apparatus are disclosed. By providing a plurality of intermediate layers made of a CoCr alloy of which saturation magnetic flux densities are controlled within a predetermined range, the magnetic recording medium, and the magnetic recording medium driving apparatus, realize a high S/Nm and thermal stability.
    Type: Grant
    Filed: May 4, 2004
    Date of Patent: September 25, 2007
    Assignee: Fujitsu Limited
    Inventors: Akiko Handa, Kazuhisa Shida, Noriyuki Asakura, Akira Kikuchi
  • Publication number: 20040252411
    Abstract: A magnetic recording medium and a magnetic recording medium driving apparatus are disclosed. By providing a plurality of intermediate layers made of a CoCr alloy of which saturation magnetic flux densities are controlled within a predetermined range, the magnetic recording medium, and the magnetic recording medium driving apparatus, realize a high S/Nm and thermal stability.
    Type: Application
    Filed: May 4, 2004
    Publication date: December 16, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Akiko Handa, Kazuhisa Shida, Noriyuki Asakura, Akira Kikuchi