Patents by Inventor Katsumoto Onoyama

Katsumoto Onoyama 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: 7872826
    Abstract: Embodiments in accordance with the present invention provide a disk storage device and a control method for the disk storage device, which are capable of precluding an off-track write resulted from stick-slip caused by thermal distortion. A magnetic disk device is provided with a magnetic disk, a head that makes a writing to the magnetic disk, and a temperature sensor that detects the temperature inside of the magnetic disk device. Moreover, the magnetic disk device 1 changes determination requirements for use to make a determination whether or not to prohibit the writing by the head to the magnetic disk based on a measurement temperature detected by the temperature sensor and an amount of temperature change calculated using the measurement temperature.
    Type: Grant
    Filed: October 27, 2006
    Date of Patent: January 18, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Sumie Takeda, Katsumoto Onoyama, Yosuke Hamada, Hiroyuki Oosawa
  • Patent number: 7636218
    Abstract: Embodiments of the present invention prevent occurrence of a write pole erasure in the event of a power failure within a magnetic disk apparatus of a perpendicular magnetic recording system. According to one embodiment of the present invention, a recording current is flowed through a magnetic head to record data in a magnetic disk. An occurrence of a power failure in the magnetic disk apparatus is detected. When a power failure has occurred, the recording head is demagnetized with power in case of a power failure. The recording head is unloaded after the recording head has been demagnetized. For the power in case of a power failure, back electromotive force of a spindle motor can be utilized. As a result, effects exerted on data recorded in the magnetic disk due to residual magnetism remaining in the recording head can be eliminated.
    Type: Grant
    Filed: July 27, 2007
    Date of Patent: December 22, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Sumie Takeda, Katsumoto Onoyama, Iwao Oshimi, Hiroyuki Oosawa
  • Publication number: 20080024897
    Abstract: Embodiments of the present invention prevent occurrence of a write pole erasure in the event of a power failure within a magnetic disk apparatus of a perpendicular magnetic recording system. According to one embodiment of the present invention, a recording current is flowed through a magnetic head to record data in a magnetic disk. An occurrence of a power failure in the magnetic disk apparatus is detected. When a power failure has occurred, the recording head is demagnetized with power in case of a power failure. The recording head is unloaded after the recording head has been demagnetized. For the power in case of a power failure, back electromotive force of a spindle motor can be utilized. As a result, effects exerted on data recorded in the magnetic disk due to residual magnetism remaining in the recording head can be eliminated.
    Type: Application
    Filed: July 27, 2007
    Publication date: January 31, 2008
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Sumie Takeda, Katsumoto Onoyama, Iwao Oshimi, Hiroyuki Oosawa
  • Publication number: 20070153412
    Abstract: Embodiments in accordance with the present invention provide a disk storage device and a control method for the disk storage device, which are capable of precluding an off-track write resulted from stick-slip caused by thermal distortion. A magnetic disk device is provided with a magnetic disk, a head that makes a writing to the magnetic disk, and a temperature sensor that detects the temperature inside of the magnetic disk device. Moreover, the magnetic disk device 1 changes determination requirements for use to make a determination whether or not to prohibit the writing by the head to the magnetic disk based on a measurement temperature detected by the temperature sensor and an amount of temperature change calculated using the measurement temperature.
    Type: Application
    Filed: October 27, 2006
    Publication date: July 5, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Sumie Takeda, Katsumoto Onoyama, Yosuke Hamada, Hiroyuki Oosawa
  • Patent number: 7154688
    Abstract: In a disk device in which heads are positioned by a servo mechanism, the object of the present invention is to prevent data from being destroyed by incorrect selection of a head and to improve reliability in recording or reproducing information and to prevent format efficiency from being decreased thereby. For this object, a SAM pattern in a servo information region is changed for each head and recorded. Then, the SAM pattern is read to determine which head makes access to a disk surface and the head is compared with a head to which a direction of making access is given thereby to make an error check. Moreover, by the use of a marker pattern of rotational synchronization compensating data added to the servo information, an error check of the head making access to the disc surface is conducted.
    Type: Grant
    Filed: February 13, 2003
    Date of Patent: December 26, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Iwao Oshimi, Kiyotada Itou, Katsumoto Onoyama, Yosuke Hamada
  • Patent number: 6909575
    Abstract: In a magnetic disk drive that performs the seek operation of a magnetic head by a VCM, a characteristic that is excellent in fault tolerance that will not generate a fault in severe environment, such as a high temperature and the issue of high frequency command without requiring a special device and special operation and without deteriorating access performance. For this purpose, a VCM current and a VCM voltage are measured and VCM back electromotive force is calculated based on both results. At seek operation, position information located on a magnetic disk is sampled and a traveling velocity is detected from the difference of the sampled result. VCM coil temperature is estimated from the difference between the traveling velocity and the VCM back electromotive force. The magnetic disk drive moves low velocity seek mode when the estimated value of this VCM coil temperature exceeded a specified value.
    Type: Grant
    Filed: July 19, 2002
    Date of Patent: June 21, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Yoshio Soyama, Yuji Hata, Katsumoto Onoyama
  • Publication number: 20040042113
    Abstract: In a disk device in which heads are positioned by a servo mechanism, the object of the present invention is to prevent data from being destroyed by incorrect selection of a head and to improve reliability in recording or reproducing information and to prevent format efficiency from being decreased thereby.
    Type: Application
    Filed: February 13, 2003
    Publication date: March 4, 2004
    Inventors: Iwao Oshimi, Kiyotada Itou, Katsumoto Onoyama, Yosuke Hamada
  • Publication number: 20030048571
    Abstract: In a magnetic disk drive that performs the seek operation of a magnetic head by a VCM, a characteristic that is excellent in fault tolerance that will not generate a fault in severe environment, such as a high temperature and the issue of high frequency command without requiring a special device and special operation and without deteriorating access performance.
    Type: Application
    Filed: July 19, 2002
    Publication date: March 13, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Yoshio Soyama, Yuji Hata, Katsumoto Onoyama
  • Patent number: 6407876
    Abstract: A sector servo type magnetic disk apparatus is provided with, in addition to servo signals, a sensor such as an accelerometer for detecting a state of a magnetic head or a support for the magnetic head at a period shorter than a sampling period of the servo signals. Since an accelerometer mounted on the magnetic head or the support for the magnetic head detects an acceleration, the control performance of a servo control system can be improved, such as reduction of generation of mechanism resonance vibrations of a carriage and improvement on detection precision of a speed signal.
    Type: Grant
    Filed: November 8, 2001
    Date of Patent: June 18, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Yamaguchi, Katsuhiro Tsuneta, Katsumoto Onoyama, Tsuyoshi Arai, Yoshikatsu Fujii, Hidehiko Numasato, Yosuke Hamada, Masahito Kobayashi
  • Patent number: 6335845
    Abstract: A sector servo type magnetic disk apparatus is provided with, in addition to servo signals, a sensor such as an accelerometer for detecting a state of a magnetic head or a support for the magnetic head at a period shorter than a sampling period of the servo signals. Since an accelerometer mounted on the magnetic head or the support for the magnetic head detects an acceleration, the control performance of a servo control system can be improved, such as reduction of generation of mechanism resonance vibrations of a carriage and improvement on detection precision of a speed signal.
    Type: Grant
    Filed: July 22, 1998
    Date of Patent: January 1, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Yamaguchi, Katsuhiro Tsuneta, Katsumoto Onoyama, Tsuyoshi Arai, Yoshikatsu Fujii, Hidehiko Numasato, Yosuke Hamada, Masahito Kobayashi
  • Patent number: 5986845
    Abstract: An apparatus for positioning a magnetic head includes a servo signal detection circuit for detecting a servo signal recorded on a magnetic disk in a predetermined first period, an acceleration measuring portion which is fitted to a part of a mechanism for mounting a magnetic head, outputs an acceleration signal in a direction of positioning the magnetic head, and samples the acceleration signal in a second period shorter than the first period, a comparison processing portion for comparing a deviation value computed from at least either one of the acceleration signal and the servo signal with a predetermined value, a write inhibit signal generating portion for generating a signal inhibiting write of data on a magnetic disk in accordance with the result of comparison in the comparison processing portion, and a manipulated variable compensation portion for generating manipulated variable for adjusting the position of the magnetic head from at least either one of the servo signal and the acceleration signal and a
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: November 16, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Yamaguchi, Katsuhiro Tsuneta, Katsumoto Onoyama, Tsuyoshi Arai, Yoshikatsu Fujii, Hidehiko Numasato, Yosuke Hamada, Masahito Kobayashi
  • Patent number: 5469311
    Abstract: A magnetic disk apparatus includes a base coupled to a supporting frame by means of a damping member so that the vibration caused by the operation of the internal actuator subsides. The damping member may include an adhesive resilient material disposed between the base and the supporting frame.
    Type: Grant
    Filed: June 13, 1994
    Date of Patent: November 21, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Nishida, Kazuo Nakagoshi, Kenjiro Kai, Katsumoto Onoyama