Patents by Inventor Junichi Yasumori

Junichi Yasumori 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: 9093100
    Abstract: A magnetic recording medium enabling excellent magnetic recording reproduction characteristics to be exhibited with the spacing loss reduced. The magnetic recording medium has a magnetic recording layer of a granular structure having nonmagnetic boundary portions between pillar-shaped magnetic particles on a nonmagnetic substrate, and an exchange coupling layer provided on the magnetic recording layer to add an action of exchange coupling the magnetic particles. Ion irradiation on the entire surface of the exchange coupling layer after layering the exchange coupling layer on the magnetic recording layer is performed.
    Type: Grant
    Filed: March 22, 2013
    Date of Patent: July 28, 2015
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Junichi Yasumori, Yoshiaki Sonobe
  • Patent number: 8634155
    Abstract: The invention provides a magnetic disk that solves (1) a problem of cross-talk that cannot be solved even by an existing thermally assisted recording method or a discrete method (DTM or the like), (2) a problem of surface flatness, which an existing embedding type DTM or the like has, and (3) a problem of a difference in thermal expansion coefficient between materials when a thermally assisted method is applied to the DTM, and that (4) does not necessitate a special medium structure, and is excellent in a surface flatness and economically and functionally high in realizability. A DTM manufactured by ion implantation is excellent in the surface flatness, and can solve the cross-talk problem by conducting the thermally assisted recording at a temperature between a Curie temperature (Tcn) of a portion where ions are implanted (non-recording region) and a Curie temperature (Tcr) of a portion where ions are not implanted (recording region).
    Type: Grant
    Filed: March 29, 2011
    Date of Patent: January 21, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Junichi Yasumori, Yoshiaki Sonobe
  • Patent number: 8605388
    Abstract: It is an object to manufacture magnetic recording media with the high recording density. Since nonmagnetic portions (8) with a predetermined pattern are formed in a recording auxiliary layer (4) formed on a magnetic recording layer (3), it is possible to actualize a magnetic recording medium where magnetic portions (7) and the magnetic recording layer (3) immediately below the portions (7) are recording units. The nonmagnetic portions (8) are formed by non-magnetization using ion implantation, and it is thereby possible to manufacture magnetic recording media with the high recording density.
    Type: Grant
    Filed: March 9, 2009
    Date of Patent: December 10, 2013
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Junichi Yasumori, Yoshiaki Sonobe, Tadashi Tomonaga
  • Patent number: 8414966
    Abstract: To provide a magnetic recording medium enabling excellent magnetic recording reproduction characteristics to be exhibited with the spacing loss reduced and a manufacturing method of the medium, a method of manufacturing a magnetic recording medium of the invention is to manufacture a magnetic recording medium having a magnetic recording layer of a granular structure having nonmagnetic boundary portions between pillar-shaped magnetic particles on a nonmagnetic substrate, and an exchange coupling layer provided on the magnetic recording layer to add an action of exchange coupling the magnetic particles, and is characterized by having an ion irradiation step of performing ion irradiation on the entire surface of the exchange coupling layer after layering the exchange coupling layer on the magnetic recording layer.
    Type: Grant
    Filed: March 9, 2009
    Date of Patent: April 9, 2013
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Junichi Yasumori, Yoshiaki Sonobe
  • Publication number: 20120075740
    Abstract: The invention provides a magnetic disk that solves (1) a problem of cross-talk that cannot be solved even by an existing thermally assisted recording method or a discrete method (DTM or the like), (2) a problem of surface flatness, which an existing embedding type DTM or the like has, and (3) a problem of a difference in thermal expansion coefficient between materials when a thermally assisted method is applied to the DTM, and that (4) does not necessitate a special medium structure, and is excellent in a surface flatness and economically and functionally high in realizability. A DTM manufactured by ion implantation is excellent in the surface flatness, and can solve the cross-talk problem by conducting the thermally assisted recording at a temperature between a Curie temperature (Tcn) of a portion where ions are implanted (non-recording region) and a Curie temperature (Tcr) of a portion where ions are not implanted (recording region).
    Type: Application
    Filed: March 29, 2011
    Publication date: March 29, 2012
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: JUNICHI YASUMORI, YOSHIAKI SONOBE
  • Publication number: 20100321826
    Abstract: It is an object to manufacture magnetic recording media with the high recording density. Since nonmagnetic portions (8) with a predetermined pattern are formed in a recording auxiliary layer (4) formed on a magnetic recording layer (3), it is possible to actualize a magnetic recording medium where magnetic portions (7) and the magnetic recording layer (3) immediately below the portions (7) are recording units. The nonmagnetic portions (8) are formed by non-magnetization using ion implantation, and it is thereby possible to manufacture magnetic recording media with the high recording density.
    Type: Application
    Filed: March 9, 2009
    Publication date: December 23, 2010
    Applicant: HOYA CORPORATION
    Inventors: Junichi Yasumori, Yoshiaki Sonobe, Tadashi Tomonaga
  • Publication number: 20100309584
    Abstract: To provide a magnetic recording medium enabling excellent magnetic recording reproduction characteristics to be exhibited with the spacing loss reduced and a manufacturing method of the medium, a method of manufacturing a magnetic recording medium of the invention is to manufacture a magnetic recording medium having a magnetic recording layer of a granular structure having nonmagnetic boundary portions between pillar-shaped magnetic particles on a nonmagnetic substrate, and an exchange coupling layer provided on the magnetic recording layer to add an action of exchange coupling the magnetic particles, and is characterized by having an ion irradiation step of performing ion irradiation on the entire surface of the exchange coupling layer after layering the exchange coupling layer on the magnetic recording layer.
    Type: Application
    Filed: March 9, 2009
    Publication date: December 9, 2010
    Applicant: HOYA CORPORATION
    Inventors: Junichi Yasumori, Yoshiaki Sonobe