Patents by Inventor Toshihiko Tsunokawa

Toshihiko Tsunokawa 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: 9142252
    Abstract: In one embodiment, a magnetic disk drive includes a magnetic disk having data tracks, a magnetic head, a motion mechanism for moving the magnetic head, and a controller. The controller adds a value to a rewrite parameter for a rewrite region based on a number of writes to data tracks related to the rewrite region, the value is chosen to reflect a degree of influence the number of writes have on the rewrite region, and the magnetic head rewrites data of the rewrite region when the rewrite parameter is greater than a threshold. In another embodiment, a method includes writing data tracks in a rewrite region, defining values reflecting a degree(s) of influence on the rewrite region, adding the values to a rewrite parameter upon writing data to the data tracks, determining that the rewrite parameter has reached or exceeded a threshold and rewriting data in the rewrite region.
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: September 22, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Toru Aida, Shuhsuke Kurihara, Toshihiko Tsunokawa, Hideaki Maeda
  • Patent number: 8098448
    Abstract: A method for dividing a data area on a disk into a plurality of concentric zones and determining a format for each zone so that data tracks in the zone have the same number of data sectors. The method includes dividing a data area into a plurality of zones with provisional boundaries. The method also includes determining a linear recording density for a selected zone. The method further includes selecting the number of data sectors per data track corresponding to the determined linear recording density from specified values. Moreover, the method includes resetting a boundary of the zone at a new boundary shifted from the provisional boundary according to a selected value.
    Type: Grant
    Filed: December 16, 2009
    Date of Patent: January 17, 2012
    Assignee: Hitachi Global Storage Technologies, Netherlands B.V.
    Inventors: Yoshihiko Maeda, Masaomi Ikeda, Nobuhiro Kuwamura, Toshihiko Tsunokawa, Akira Osaki
  • Patent number: 8068299
    Abstract: Embodiments of the present invention help to reduce the occurrence of read hard errors in a hard disk drive (HDD). According to one embodiment, a HDD rewrites data on all data tracks of a block M when the number of write operations to the block consisting of continuous plural data tracks. The HDD further rewrites data on continuous plural data tracks and adjacent to the block. Since the number of write operations is counted every block, a memory area to register the number of write operations can be reduced.
    Type: Grant
    Filed: March 26, 2008
    Date of Patent: November 29, 2011
    Assignee: Hitachi Global Storage Technologies, Netherlands B.V.
    Inventors: Toshihiko Tsunokawa, Nobuhiro Kuwamura, Masutaka Harada, Yuhji Yokoe, Takao Matsui
  • Publication number: 20110085259
    Abstract: A method for dividing a data area on a disk into a plurality of concentric zones and determining a format for each zone so that data tracks in the zone have the same number of data sectors. The method includes dividing a data area into a plurality of zones with provisional boundaries. The method also includes determining a linear recording density for a selected zone. The method further includes selecting the number of data sectors per data track corresponding to the determined linear recording density from specified values. Moreover, the method includes resetting a boundary of the zone at a new boundary shifted from the provisional boundary according to a selected value.
    Type: Application
    Filed: December 16, 2009
    Publication date: April 14, 2011
    Inventors: Yoshihiko MAEDA, Masaomi Ikeda, Nobuhiro Kuwamura, Toshihiko Tsunokawa, Akira Osaki
  • Publication number: 20100321817
    Abstract: In one embodiment, a magnetic disk drive includes a magnetic disk having data tracks, a magnetic head, a motion mechanism for moving the magnetic head, and a controller. The controller adds a value to a rewrite parameter for a rewrite region based on a number of writes to data tracks related to the rewrite region, the value is chosen to reflect a degree of influence the number of writes have on the rewrite region, and the magnetic head rewrites data of the rewrite region when the rewrite parameter is greater than a threshold. In another embodiment, a method includes writing data tracks in a rewrite region, defining values reflecting a degree(s) of influence on the rewrite region, adding the values to a rewrite parameter upon writing data to the data tracks, determining that the rewrite parameter has reached or exceeded a threshold and rewriting data in the rewrite region.
    Type: Application
    Filed: June 23, 2010
    Publication date: December 23, 2010
    Inventors: Toru Aida, Shuhsuke Kurihara, Toshihiko Tsunokawa, Hideaki Maeda
  • Publication number: 20080239901
    Abstract: Embodiments of the present invention help to reduce the occurrence of read hard errors in a hard disk drive (HDD). According to one embodiment, a HDD rewrites data on all data tracks of a block M when the number of write operations to the block consisting of continuous plural data tracks. The HDD further rewrites data on continuous plural data tracks and adjacent to the block. Since the number of write operations is counted every block, a memory area to register the number of write operations can be reduced.
    Type: Application
    Filed: March 26, 2008
    Publication date: October 2, 2008
    Inventors: Toshihiko Tsunokawa, Nobuhiro Kuwamura, Masutaka Harada, Yuhji Yokoe, Takao Matsui
  • Patent number: 7019921
    Abstract: A method and apparatus for use with a rotating storage device. The rotating storage device includes a storage medium driven to rotate, a head for reading and writing information on the storage medium and a ramped loading mechanism in which the head is stored. In accordance with the method of the present invention, the head is loaded from the ramped loading mechanism onto the storage medium. Next, determining whether or not a write operation on said storage medium is performed within a predetermined amount of time after loading said head on said storage medium and in response to said determination, setting a verification flag to indicate a data verification is required immediately after said write operation.
    Type: Grant
    Filed: January 8, 2004
    Date of Patent: March 28, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Naoyuki Kagami, Masayuki Kanamaru, Shunichiroh Ohta, Akira Tokizono, Toshihiko Tsunokawa
  • Publication number: 20040179288
    Abstract: A method and apparatus for use with a rotating storage device. The rotating storage device includes a storage medium driven to rotate, a head for reading and writing information on the storage medium and a ramped loading mechanism in which the head is stored. In accordance with the method of the present invention, the head is loaded from the ramped loading mechanism onto the storage medium. Next, location information stored in said storage medium via said head is read. A location of the head is then retained for a predetermined period above a track of a region other than a valid storage region of said storage medium after successfully reading the location information.
    Type: Application
    Filed: January 8, 2004
    Publication date: September 16, 2004
    Applicant: International Business Machines Corporation
    Inventors: Naoyuki Kagami, Masayuki Kanamaru, Shunichiroh Ohta, Akira Tokizono, Toshihiko Tsunokawa
  • Patent number: 6707634
    Abstract: A method and apparatus for use with a rotating storage device. The rotating storage device includes a storage medium driven to rotate, a head for reading and writing information on the storage medium and a ramped loading mechanism in which the head is stored. In accordance with the method of the present invention, the head is loaded from the ramped loading mechanism onto the storage medium. Next, location information stored in the storage medium via the head is read. A location of the head is then retained for a predetermined period above a track of a region other than a valid storage region of the storage medium after successfully reading the location information.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: March 16, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Naoyuki Kagami, Masayuki Kanamaru, Shunichiroh Ohta, Akira Tokizono, Toshihiko Tsunokawa
  • Publication number: 20020067562
    Abstract: A method and apparatus for use with a rotating storage device. The rotating storage device includes a storage medium driven to rotate, a head for reading and writing information on the storage medium and a ramped loading mechanism in which the head is stored. In accordance with the method of the present invention, the head is loaded from the ramped loading mechanism onto the storage medium. Next, location information stored in said storage medium via said head is read. A location of the head is then retained for a predetermined period above a track of a region other than a valid storage region of said storage medium after successfully reading the location information.
    Type: Application
    Filed: September 10, 2001
    Publication date: June 6, 2002
    Inventors: Naoyuki Kagami, Masayuki Kanamaru, Shunichiroh Ohta, Akira Tokizono, Toshihiko Tsunokawa