Patents by Inventor Kazumasa Shimoda

Kazumasa Shimoda 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: 7525762
    Abstract: A perpendicular magnetic recording medium at least comprises a perpendicular magnetic recording layer and a backing layer backing the perpendicular magnetic recording layer. The backing layer has an in-plane magnetization and is formed of a ferrimagnetic material having a compensation temperature in the vicinity of a recording/reproducing temperature in which reproducing of magnetic information is made from the perpendicular magnetic recording layer. A magnetic storage apparatus for recording and reproducing magnetic information using the perpendicular magnetic recording medium is also disclosed.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: April 28, 2009
    Assignee: Fujitsu Limted
    Inventors: Ryosaku Inamura, Kazumasa Shimoda, Toshio Sugimoto, Takuya Uzumaki
  • Patent number: 7295404
    Abstract: A perpendicular magnetic recording medium at least comprises a perpendicular magnetic recording layer and a backing layer backing the perpendicular magnetic recording layer. The backing layer has an in-plane magnetization and is formed of a ferrimagnetic material having a compensation temperature in the vicinity of a recording/reproducing temperature in which reproducing of magnetic information is made from the perpendicular magnetic recording layer. A magnetic storage apparatus for recording and reproducing magnetic information using the perpendicular magnetic recording medium is also disclosed.
    Type: Grant
    Filed: January 30, 2007
    Date of Patent: November 13, 2007
    Assignee: Fujitsu Limited
    Inventors: Ryosaku Inamura, Kazumasa Shimoda, Toshio Sugimoto, Takuya Uzumaki
  • Publication number: 20070124749
    Abstract: A perpendicular magnetic recording medium at least comprises a perpendicular magnetic recording layer and a backing layer backing the perpendicular magnetic recording layer. The backing layer has an in-plane magnetization and is formed of a ferrimagnetic material having a compensation temperature in the vicinity of a recording/reproducing temperature in which reproducing of magnetic information is made from the perpendicular magnetic recording layer. A magnetic storage apparatus for recording and reproducing magnetic information using the perpendicular magnetic recording medium is also disclosed.
    Type: Application
    Filed: January 30, 2007
    Publication date: May 31, 2007
    Inventors: Ryosaku Inamura, Kazumasa Shimoda, Toshio Sugimoto, Takuya Uzumaki
  • Publication number: 20050196649
    Abstract: A perpendicular magnetic recording medium includes a magnetic orientation controller layer serving as a layer for controlling crystalline orientation in an upper layer. A non-magnetic orientation controller layer extends on the surface of the magnetic orientation controller layer The non-magnetic orientation controller layer serves as a layer for controlling crystalline orientation in an upper layer. A magnetic recording layer extends on the surface of the non-magnetic orientation controller layer. The perpendicular magnetic recording medium allows a reliable establishment of a uniform crystalline orientation in the magnetic recording layer based on the influences from the magnetic and non-magnetic orientation controller layers. A reliable establishment of a uniform crystalline orientation can be achieved without an increase in the thickness of the non-magnetic orientation controller layer.
    Type: Application
    Filed: March 28, 2005
    Publication date: September 8, 2005
    Inventors: Ryosaku Inamura, Hiroto Takeshita, Toshio Sugimoto, Kazumasa Shimoda, Takenori Oshima, Maki Maeda, Takuya Uzumaki, Atsushi Tanaka
  • Publication number: 20050042481
    Abstract: A perpendicular magnetic recording medium including a substrate, a roughness control layer provided on the substrate and having a rough surface with a grain size of 5 to 20 nm and an average roughness (Ra) of 0.2 to 2.0 nm, and an orientation control layer provided on the roughness control layer and containing 30 at % or more of metal solely having an fcc structure. The perpendicular magnetic recording medium further includes a magnetic recording layer having perpendicular magnetic anisotropy provided on the orientation control layer in contact therewith. The magnetic recording layer is formed from a multilayer film composed of ferromagnetic thin films and nonmagnetic thin films alternately stacked.
    Type: Application
    Filed: October 6, 2004
    Publication date: February 24, 2005
    Inventors: Kazumasa Shimoda, Takuya Uzumaki
  • Patent number: 6809893
    Abstract: A storage system has a storage medium, a head, and a control unit for carrying out refresh processing. A refresh operation extracts data that needs to be refreshed by measuring the read-out output level of target data. Then, data requiring refresh is re-recorded to the storage medium by the head. Because an actual data level is observed, it is possible to accurately detect refresh target data, and because there is no need for a reference area, it is possible to prevent a reduction in storage capacity.
    Type: Grant
    Filed: January 26, 2001
    Date of Patent: October 26, 2004
    Assignee: Fujitsu Limited
    Inventors: Takuya Uzumaki, Kazumasa Shimoda, Hiroto Takeshita, Atsushi Tanaka
  • Patent number: 6744582
    Abstract: A thermal-assisted magnetic storage device includes a magnetic recording media of a transparent material, a first marker of a material that is optically singular compared with materials therearound, and a magnetic head disposed on a magnetic head slider facing a recording surface of the magnetic recording media. A light-beam pickup faces the other surface of the magnetic recording media, so as to emit light therefrom to the surface of the magnetic recording media. A second marker is disposed on the magnetic head slider for roughly guiding the light to the first marker. An alignment between the light and the magnetic head is performed in accordance with the light reflected from the first marker.
    Type: Grant
    Filed: July 18, 2001
    Date of Patent: June 1, 2004
    Assignee: Fujitsu Limited
    Inventors: Kazumasa Shimoda, Takuya Uzumaki
  • Publication number: 20040101714
    Abstract: A perpendicular magnetic recording medium at least comprises a perpendicular magnetic recording layer and a backing layer backing the perpendicular magnetic recording layer. The backing layer has an in-plane magnetization and is formed of a ferrimagnetic material having a compensation temperature in the vicinity of a recording/reproducing temperature in which reproducing of magnetic information is made from the perpendicular magnetic recording layer.
    Type: Application
    Filed: November 20, 2003
    Publication date: May 27, 2004
    Applicant: Fujitsu Limited
    Inventors: Ryosaku Inamura, Kazumasa Shimoda, Toshio Sugimoto, Takuya Uzumaki
  • Publication number: 20030207154
    Abstract: The magnetic characteristic of a film of magnetic recording medium in the thermo-magnetic recording system is stabilized. After a non-magnetic film (3), a magnetic film (4) including magnetic material are laminated on a substrate (2), the magnetic recording medium (1) is annealed with the temperature higher than the heating temperature for the magnetic recording medium required for writing of data.
    Type: Application
    Filed: May 5, 2003
    Publication date: November 6, 2003
    Applicant: FUJITSU LIMITED
    Inventor: Kazumasa Shimoda
  • Publication number: 20020098386
    Abstract: The magnetic characteristic of a film of magnetic recording medium in the thermo-magnetic recording system is stabilized. After a non-magnetic film (3) a magnetic film (4) including magnetic material are laminated on a substrate (2), the magnetic recording medium (1) is annealed with the temperature higher than the heating temperature for the magnetic recording medium required for writing of data.
    Type: Application
    Filed: November 16, 2001
    Publication date: July 25, 2002
    Applicant: FUJITSU LIMITED
    Inventor: Kazumasa Shimoda
  • Publication number: 20020008930
    Abstract: [SUBJECT] To accomplish accurate alignment between a reading/writing magnetic head and light-beam pickup of a thermal-assisted magnetic storage device, and thereby to realize a compact-size and higher capacity magnetic storage device without reading/writing errors.
    Type: Application
    Filed: July 18, 2001
    Publication date: January 24, 2002
    Inventors: Kazumasa Shimoda, Takuya Uzumaki
  • Patent number: 6277484
    Abstract: A magnetic recording medium using a substrate, such as a glass substrate, and having, in combination, superior magnetic and magnetic recording properties and good adhesion of a magnetic layer to the substrate. The magnetic recording medium has an intermediate layer of chromium between the substrate and an underlayer of Ni-based non-magnetic material on which a magnetic layer of Co-based magnetic alloy is superimposed. A method of producing the magnetic recording medium is also disclosed, wherein each of the layers is formed by a sputtering process at a sufficient pressure to promote granular growth of crystals of the layer.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: August 21, 2001
    Assignee: Fujitsu Limited
    Inventors: Kazumasa Shimoda, Ryoichi Mukai, Hiroto Takeshita
  • Publication number: 20010010603
    Abstract: Disclosed is a data refresh method for preventing the disappearance of data on a storage medium, and for detecting refresh target data accurately and in a short time. A storage system has a storage medium 6, a head 4, and a control unit 30 for carrying out refresh processing. A refresh operation extracts data that needs to be refreshed by measuring the read-out output level of target data. Then, data requiring the refresh is re-recorded to the storage medium 6 by the head 4. Because an actual data level is observed, it is possible to accurately detect refresh target data, and because there is no need for a reference area, it is possible to prevent a reduction in storage capacity.
    Type: Application
    Filed: January 26, 2001
    Publication date: August 2, 2001
    Applicant: FUJITSU LIMITED
    Inventors: Takuya Uzumaki, Kazumasa Shimoda, Hiroto Takeshita, Atsushi Tanaka