Patents by Inventor Toshihisa KIYONAGA

Toshihisa KIYONAGA 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: 10665255
    Abstract: A data storage device is disclosed comprising a disk comprising servo data, a spindle motor configured to rotate the disk, and a head actuated over the disk. A position error signal (PES) is generated based on the servo data, and the head is actuated over the disk based on the PES. While swinging a speed of the spindle motor, the swinging is disabled based on the PES.
    Type: Grant
    Filed: June 18, 2019
    Date of Patent: May 26, 2020
    Assignee: Western Digital Technologies, Inc.
    Inventors: Peng Huang, Toshihisa Kiyonaga, Masahito Kobayashi, Hiroaki Sakuma
  • Patent number: 10347278
    Abstract: A data storage device is disclosed comprising a first actuator configured to actuate a first head over a first disk comprising a first plurality of tracks defined by first servo sectors, and a second actuator configured to actuate a second head over a second disk comprising a second plurality of tracks defined by second servo sectors. The first actuator is controlled based on the first servo sectors in order to first write data to the first disk, and the second actuator is controlled based on the second servo sectors in order to second write data to the second disk. The first writing is inhibited when a shock signal generated based on a shock sensor exceeds a first shock threshold, and the second writing is inhibited when the shock signal exceeds a second shock threshold different from the first shock threshold.
    Type: Grant
    Filed: October 24, 2018
    Date of Patent: July 9, 2019
    Assignee: Western Digital Technologies, Inc.
    Inventors: Toshihisa Kiyonaga, Peng Huang, Junya Takeda, Edward C. Sibal
  • Patent number: 10014018
    Abstract: A data storage device is disclosed comprising a first voice coil motor (VCM) configured to actuate a first head, and a second VCM configured to actuate a second head. A high priority is assigned to the first VCM and a low priority to the second VCM. A first access command is serviced using the first head by seeking the first VCM using a first high performance seek profile. When seeking the second VCM without seeking the first VCM, a second access command is serviced using the second head using a second high performance seek profile. When concurrently seeking the first VCM and the second VCM, the seeking of the second VCM is with a reduced performance seek profile, wherein the second high performance seek profile decreases a seek time of the second VCM compared to the reduced performance seek profile.
    Type: Grant
    Filed: December 15, 2017
    Date of Patent: July 3, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Toshihisa Kiyonaga, Peng Huang, Kexiu Liu
  • Patent number: 9940958
    Abstract: A data storage device is disclosed wherein multiple voice coil motors (VCMs) are unloaded using a back electromotive force (BEMF) voltage generated by a spindle motor. A velocity and position of each VCM is measured, and a priority assigned to each VCM based on the measured velocity and position. During a delay interval, the BEMF voltage is used to apply a first brake voltage to a high priority VCM and to apply a second brake voltage to a low priority VCM, wherein the second brake voltage is lower than the first brake voltage. After the delay interval, the BEMF voltage is used to apply the first brake voltage to the high priority VCM and to apply a third brake voltage to the low priority VCM, wherein the third brake voltage is higher than the second brake voltage.
    Type: Grant
    Filed: November 7, 2017
    Date of Patent: April 10, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Toshihisa Kiyonaga, Peng Huang, Brian K. Tanner, Paolo Capretta
  • Patent number: 8804269
    Abstract: A HDD including a temperature sensor for sensing ambient temperature in the HDD, a spindle motor comprising a fluid dynamic bearing; and a controller configured for adjusting a rotational speed of the spindle motor based on the measured ambient temperature while a rigidity of the fluid dynamic bearing is maintained, and reducing power consumption of the HDD based on the adjusting the rotational speed of the spindle motor.
    Type: Grant
    Filed: December 6, 2011
    Date of Patent: August 12, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Takao Suzuki, Kohji Takahashi, Tomoki Hiramatsu, Toshihisa Kiyonaga
  • Patent number: 8593752
    Abstract: A HDD including write components configured to operate within an operating voltage range, charging circuitry comprising a charging capacitor. The charging capacitor includes a higher voltage when charged than the operating voltage range. The HDD also includes pulse circuitry configured to pulse power from the charging circuitry to the write components within the operating voltage range during a controlled shut down of the write components such that remaining data-sector bits are written during the controlled shut down.
    Type: Grant
    Filed: October 8, 2010
    Date of Patent: November 26, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Toshihisa Kiyonaga, Yasuhiro Iihara, Yoshiroh Amano, Yoshifumi Kataoka
  • Publication number: 20130141815
    Abstract: A HDD including a temperature sensor for sensing ambient temperature in the HDD, a spindle motor comprising a fluid dynamic bearing; and a controller configured for adjusting a rotational speed of the spindle motor based on the measured ambient temperature while a rigidity of the fluid dynamic bearing is maintained, and reducing power consumption of the HDD based on the adjusting the rotational speed of the spindle motor.
    Type: Application
    Filed: December 6, 2011
    Publication date: June 6, 2013
    Inventors: Takao Suzuki, Kohji Takahashi, Tomoki Hiramatsu, Toshihisa Kiyonaga
  • Publication number: 20120087032
    Abstract: A HDD including write components configured to operate within an operating voltage range, charging circuitry comprising a charging capacitor. The charging capacitor includes a higher voltage when charged than the operating voltage range. The HDD also includes pulse circuitry configured to pulse power from the charging circuitry to the write components within the operating voltage range during a controlled shut down of the write components such that remaining data-sector bits are written during the controlled shut down.
    Type: Application
    Filed: October 8, 2010
    Publication date: April 12, 2012
    Inventors: Toshihisa KIYONAGA, Yasuhiro IIHARA, Yoshiroh AMANO, Yoshifumi KATAOKA