Patents by Inventor Hongchao Tim Zhao

Hongchao Tim Zhao 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).

  • Adaptive threshold for detecting touchdown or contamination
    Patent number: 8665546
    Abstract: A disk drive is disclosed comprising a disk, a head for writing data to the disk, and control circuitry coupled to the head. The control circuitry is operable to determine a first set of fly height values and determine a threshold based on the first set of fly height values. The control circuitry determines a second set of fly height values, adjusts the threshold based on the second set of fly height values, and detects a head characteristic based on the adjusted threshold. The head characteristic is detected by detecting a head touchdown event and/or detecting contamination related to the head based on the adjusted threshold.
    Type: Grant
    Filed: January 7, 2010
    Date of Patent: March 4, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Hongchao Tim Zhao, Jiangang Liang, Yilin Cai, Don Brunnett
  • Disk drive to reduce head instability
    Patent number: 7974039
    Abstract: A disk drive to reduce head instability during disk drive manufacturing is disclosed. The disk drive comprises: a disk; a dynamic flying height (DFH) read/write head; a flying height actuator to control the spacing between the DFH read/write head and the disk; and a controller. The controller controls operations in the disk drive including applying a sloped increasing power between a first voltage and a second voltage to move the DFH read/write head towards the disk.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: July 5, 2011
    Assignee: Western Digital Technology, Inc.
    Inventors: Jianfeng Xu, Soo-Choon Kang, Kazuhiro Saito, Hongchao Tim Zhao
  • Disk drive servoing off of first head while determining fly height for second head
    Patent number: 7630162
    Abstract: A method is disclosed for selecting a dynamic fly height (DFH) control setting for a head in a disk drive, the disk drive comprising a plurality of disk surfaces and plurality of respective heads. The method comprises servoing a first head over a first disk surface in response to servo data recorded on the first disk surface, adjusting a DFH control setting for a second head, and while servoing the first head over the first disk surface, detecting whether the second head has contacted a second disk surface.
    Type: Grant
    Filed: February 4, 2008
    Date of Patent: December 8, 2009
    Assignee: Western Digital Technologies, Inc.
    Inventors: Hongchao Tim Zhao, Jiangang Liang
  • DISK DRIVE SERVOING OFF OF FIRST HEAD WHILE DETERMINING FLY HEIGHT FOR SECOND HEAD
    Publication number: 20090195936
    Abstract: A method is disclosed for selecting a dynamic fly height (DFH) control setting for a head in a disk drive, the disk drive comprising a plurality of disk surfaces and plurality of respective heads. The method comprises servoing a first head over a first disk surface in response to servo data recorded on the first disk surface, adjusting a DFH control setting for a second head, and while servoing the first head over the first disk surface, detecting whether the second head has contacted a second disk surface.
    Type: Application
    Filed: February 4, 2008
    Publication date: August 6, 2009
    Applicant: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: HONGCHAO TIM ZHAO, JIANGANG LIANG