Patents by Inventor Kunihiro Shimada

Kunihiro Shimada 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: 10134437
    Abstract: According to one embodiment, physical position information on errors on a recording medium is acquired, physical position relationship between the errors on the recording medium is calculated based on the position information, and a failure mode related to the errors is determined based on the position relationship.
    Type: Grant
    Filed: September 6, 2016
    Date of Patent: November 20, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takehiko Tsuboi, Kunihiro Shimada, Takashi Endo, Takashi Usui, Toshiaki Ohgushi, Takeichiro Nishikawa, Daiki Kiribuchi
  • Publication number: 20170263283
    Abstract: According to one embodiment, physical position information on errors on a recording medium is acquired, physical position relationship between the errors on the recording medium is calculated based on the position information, and a failure mode related to the errors is determined based on the position relationship.
    Type: Application
    Filed: September 6, 2016
    Publication date: September 14, 2017
    Inventors: Takehiko Tsuboi, Kunihiro Shimada, Takashi Endo, Takashi Usui, Toshiaki Ohgushi, Takeichiro Nishikawa, Daiki Kiribuchi
  • Patent number: 7102843
    Abstract: A magnetic disk apparatus includes a magnetic disk with normal and double servo sectors arranged alternately. If a servo interruption period corresponding to adjacent first servo sectors is a first servo interruption period, then a second servo interruption period that is a servo interruption period corresponding to adjacent first servo sector and second servo sector is equal to or less than half of the first servo interruption period.
    Type: Grant
    Filed: October 27, 2003
    Date of Patent: September 5, 2006
    Assignee: Fujitsu Limited
    Inventors: Takeshi Hara, Mitsuo Kamimura, Yukio Abe, Yoshinari Higashino, Kunihiro Shimada, Kiyoshi Sakuma, Atsushi Suzuki, Kentaroh Katoh
  • Patent number: 6798604
    Abstract: The controller circuit is designed to generate the positioning control signal based on the positional deviation of the head from a target recording track on a recording medium. A feedback control is effected to position the head right on a trajectory corresponding to the target recording track based on the generated positioning control signal. The positioning control signal is subjected to filtering at a notch filter. The cutoff frequency of the notch filter is set depending on the temperature detected at a thermal sensor. Even when the resonant frequency shifts in response to variation in temperature, the cutoff frequency of the notch filter follows the shift of the resonant frequency. A narrower bandwidth of the cutoff frequency still achieves reduction in the amplitude of the frequency component corresponding to the resonant frequency. The resonance or continuous vibration can reliably be prevented in the head.
    Type: Grant
    Filed: October 26, 2000
    Date of Patent: September 28, 2004
    Assignee: Fujitsu Limited
    Inventors: Mitsuo Kamimura, Yoshinari Higashino, Kiyoshi Sakuma, Yukio Abe, Kunihiro Shimada, Atsushi Suzuki, Takeshi Hara, Kentaroh Katoh
  • Publication number: 20040125494
    Abstract: A magnetic disk apparatus includes a magnetic disk with normal and double servo sectors arranged alternately. If a servo interruption period corresponding to adjacent first servo sectors is a first servo interruption period, then a second servo interruption period that is a servo interruption period corresponding to adjacent first servo sector and second servo sector is equal to or less than half of the first servo interruption period.
    Type: Application
    Filed: October 27, 2003
    Publication date: July 1, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Takeshi Hara, Mitsuo Kamimura, Yukio Abe, Yoshinari Higashino, Kunihiro Shimada, Kiyoshi Sakuma, Atsushi Suzuki, Kentaroh Katoh
  • Patent number: 6084742
    Abstract: A processing unit for effecting speed control in a drive control apparatus includes a storing unit having a first table which stores discrete values having exponential intervals, and a second table which stores multiples of normalized reference values having uniform intervals from each other and relating to a distance between a driven body subject to the speed control and a target position. The discrete values lie in a range over which the normalized reference values vary and are bound in a predetermined relation to a coefficient multiplied by the normalized reference values. The normalized reference values lie in the upper 1/2 range of said discrete values.A control target value generating unit calculates a control target value relating to a target speed of the driven body, by referring to the first and second tables.
    Type: Grant
    Filed: March 28, 1997
    Date of Patent: July 4, 2000
    Assignee: Fujitsu Limited
    Inventors: Kazuhiko Takaishi, Kunihiro Shimada
  • Patent number: 5907859
    Abstract: A storage device includes: a read/write mechanism which is actuated in accordance with a selected one of two or more sets of control data so that a read/write operation is carried out to read data from or write data onto a recording medium; a detection unit for detecting a source voltage from a host system, and for detecting whether one of source voltages from the host system has been switched to another source voltage; a control unit for controlling the read/write operation of the read/write mechanism in accordance with the detected source voltage; and a reset unit for resetting the control unit to an initial condition when the switching from the one of the source voltages to the another source voltage is detected as being in process, so that the controlling of the read/write mechanism is withheld until the end of the switching.
    Type: Grant
    Filed: November 17, 1997
    Date of Patent: May 25, 1999
    Assignee: Fukitsu Limited
    Inventors: Kunihiro Shimada, Kazuhiko Takaishi, Eisaku Takahashi
  • Patent number: 5801907
    Abstract: A magnetic disk drive for locking an actuator mounted with a magnetic head in a safety zone. The magnetic disk drive comprises a magnet, fixed yoke members and a stopper for setting a stop position of rotations of the rotary actuator in such a position that torque by the fixed yoke members and the magnet is maximized. The fixed yoke members form a magnetic circuit for the magnet in all or a part of a movable range of the rotary actuator. The fixed yoke members include a first area having a gap width uniformly reduced in a lock direction to retract the rotary actuator and a second area having a gap width smaller than a gap width of the first area. The fixed yoke members are mechanically separated from each other.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: September 1, 1998
    Assignee: Fujitsu Limited
    Inventors: Norio Yagi, Kunihiro Shimada, Takehiko Katoh, Kenichi Myokan, Takashi Matsumoto, Kazuhiko Takaishi