Patents by Inventor Chiyo Saito

Chiyo Saito 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: 20150027877
    Abstract: Provided is a method of manufacturing a magnetic disk comprising a granular magnetic recording layer which causes less noise even with a recording capacity thereof of 250 G or more bits per square inch; and a method for manufacturing the same. The magnetic disk according to the present invention comprises: a granular magnetic recording layer (20) which is formed on a disk substrate 10 directly or via an intermediate layer and which has non-magnetic regions between granular columnar particles; and an auxiliary recording layer (22) which is formed on the granular magnetic recording layer 20 and which causes exchange interaction among the granular columnar particles, wherein the auxiliary recording layer (22) contains 0.1 to 3 moles of oxygen.
    Type: Application
    Filed: October 14, 2014
    Publication date: January 29, 2015
    Inventors: CHIYO SAITO, TOKICHIRO SATO, TAKENORI KAJIWARA
  • Patent number: 8922936
    Abstract: An object of the present invention is to further improve a recording density in a magnetic disk apparatus using a shingle write system. In a magnetic disk apparatus including a magnetic disk, a recording head that writes information on the magnetic disk, and a controller that controls a writing operation of the recording head to the magnetic disk, the controller controls the writing operation such that the recording head writes information on a region including a target track and a portion of track adjacent thereto in an overlapping manner while position-shifting in a radial direction of the magnetic disk and a first writing frequency to a track on which information is last written is higher than a second writing frequency to another track.
    Type: Grant
    Filed: March 24, 2011
    Date of Patent: December 30, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Iwao Okamoto, Chiyo Saito, Daisuke Masuda
  • Patent number: 8877359
    Abstract: Provided are a magnetic disk comprising a granular magnetic recording layer which causes less noise even with a recording capacity thereof of 250 G or more bits per square inch; and a method for manufacturing the same. The magnetic disk according to the present invention comprises: a granular magnetic recording layer (20) which is formed on a disk substrate 10 directly or via an intermediate layer and which has non-magnetic regions between granular columnar particles; and an auxiliary recording layer (22) which is formed on the granular magnetic recording layer 20 and which causes exchange interaction among the granular columnar particles, wherein the auxiliary recording layer (22) contains 0.1 to 3 moles of oxygen.
    Type: Grant
    Filed: December 7, 2009
    Date of Patent: November 4, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Chiyo Saito, Tokichiro Sato, Takenori Kajiwara
  • Patent number: 8665541
    Abstract: A characteristic evaluation method of a perpendicular magnetic recording medium suitable for obtaining a perpendicular magnetic recording medium which can respond to much higher recording density is provided.
    Type: Grant
    Filed: June 22, 2010
    Date of Patent: March 4, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventor: Chiyo Saito
  • Patent number: 8559131
    Abstract: [Problem] A perpendicular magnetic recording medium and a magnetic disk device that are suitable for a shingle recording type are provided. [Solution] The perpendicular magnetic recording medium of the present invention is a perpendicular magnetic recording medium for a shingle recording type having a laminated film including a soft magnetic layer 13 and a main recording layer 16 formed on base 11, the soft magnetic layer 13 having a thickness found from a core width of a magnetic head for recording and reproduction with respect to the perpendicular magnetic recording medium and a track pitch narrower than the core width.
    Type: Grant
    Filed: June 15, 2011
    Date of Patent: October 15, 2013
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Daisuke Masuda, Chiyo Saito, Junichi Horikawa, Iwao Okamoto
  • Publication number: 20120194936
    Abstract: A characteristic evaluation method of a perpendicular magnetic recording medium suitable for obtaining a perpendicular magnetic recording medium which can respond to much higher recording density is provided.
    Type: Application
    Filed: June 22, 2010
    Publication date: August 2, 2012
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventor: Chiyo Saito
  • Publication number: 20120162808
    Abstract: [Problem] A perpendicular magnetic recording medium and a magnetic disk device that are suitable for a shingle recording type are provided. [Solution] The perpendicular magnetic recording medium of the present invention is a perpendicular magnetic recording medium for a shingle recording type having a laminated film including a soft magnetic layer 13 and a main recording layer 16 formed on base 11, the soft magnetic layer 13 having a thickness found from a core width of a magnetic head for recording and reproduction with respect to the perpendicular magnetic recording medium and a track pitch narrower than the core width.
    Type: Application
    Filed: June 15, 2011
    Publication date: June 28, 2012
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Daisuke Masuda, Chiyo Saito, Junichi Horikawa, Iwao Okamoto
  • Publication number: 20120069466
    Abstract: An object of the present invention is to further improve a recording density in a magnetic disk apparatus using a shingle write system. In a magnetic disk apparatus including a magnetic disk, a recording head that writes information on the magnetic disk, and a controller that controls a writing operation of the recording head to the magnetic disk, the controller controls the writing operation such that the recording head writes information on a region including a target track and a portion of track adjacent thereto in an overlapping manner while position-shifting in a radial direction of the magnetic disk and a first writing frequency to a track on which information is last written is higher than a second writing frequency to another track.
    Type: Application
    Filed: March 24, 2011
    Publication date: March 22, 2012
    Applicant: WD Media (Singapore) Pte. Ltd.
    Inventors: Iwao Okamoto, Chiyo Saito, Daisuke Masuda
  • Publication number: 20110311841
    Abstract: Provided are a magnetic disk comprising a granular magnetic recording layer which causes less noise even with a recording capacity thereof of 250 G or more bits per square inch; and a method for manufacturing the same. The magnetic disk according to the present invention comprises: a granular magnetic recording layer (20) which is formed on a disk substrate 10 directly or via an intermediate layer and which has non-magnetic regions between granular columnar particles; and an auxiliary recording layer (22) which is formed on the granular magnetic recording layer 20 and which causes exchange interaction among the granular columnar particles, wherein the auxiliary recording layer (22) contains 0.1 to 3 moles of oxygen.
    Type: Application
    Filed: December 7, 2009
    Publication date: December 22, 2011
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Chiyo Saito, Tokichiro Sato, Takenori Kajiwara