Patents by Inventor Huanxiang Ruan

Huanxiang Ruan 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: 9972344
    Abstract: A data storage device is disclosed comprising a first head actuated over a first disk surface, wherein the first head comprises a laser configured to heat the first disk surface while writing data to the first disk surface. A write power is applied to the laser and a first write operation is executed to write first data to the first disk surface during a first revolution of the first disk surface. A first transient decrease in an output power of the laser is detected during the first write operation, and when the first transient decrease in the output power of the laser is detected during the first write operation, a write-verify of the first data is executed during a second revolution of the first disk surface.
    Type: Grant
    Filed: July 24, 2017
    Date of Patent: May 15, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Huanxiang Ruan, Galvin Chia, Prakash Balasubramaniam, Phillip S. Haralson, Dennis W. Hogg
  • Publication number: 20170323657
    Abstract: A data storage device is disclosed comprising a first head actuated over a first disk surface, wherein the first head comprises a laser configured to heat the first disk surface while writing data to the first disk surface. A write power is applied to the laser and a first write operation is executed to write first data to the first disk surface during a first revolution of the first disk surface. A first transient decrease in an output power of the laser is detected during the first write operation, and when the first transient decrease in the output power of the laser is detected during the first write operation, a write-verify of the first data is executed during a second revolution of the first disk surface.
    Type: Application
    Filed: July 24, 2017
    Publication date: November 9, 2017
    Inventors: HUANXIANG RUAN, GALVIN CHIA, PRAKASH BALASUBRAMANIAM, PHILLIP S. HARALSON, DENNIS W. HOGG
  • Patent number: 9747928
    Abstract: A data storage device is disclosed comprising a first head actuated over a first disk surface, wherein the first head comprises a laser configured to heat the first disk surface while writing data to the first disk surface. A write power is applied to the laser when executing a first write operation, and the first write operation is paused when a transient increase in the output power of the laser is detected. In another embodiment, a write-verify of the written data is executed when a transient decrease in the output power of the laser is detected.
    Type: Grant
    Filed: September 25, 2014
    Date of Patent: August 29, 2017
    Assignee: Western Digital Technologies, Inc.
    Inventors: Huanxiang Ruan, Galvin Chia, Prakash Balasubramaniam, Phillip S. Haralson, Dennis W. Hogg
  • Patent number: 9230585
    Abstract: A disk drive is disclosed including a disk having a plurality of tracks, wherein each track comprises a plurality of data sectors and a plurality of servo sectors. The disk drive further comprises a spindle motor for rotating the disk, and a head actuated radially over the disk, wherein the head comprises a dynamic fly height (DFH) heater. Control circuitry within the disk drive is operable to position the head over one of the tracks; determine a number of servo sectors to pass under the head before a target location over the track is reached, apply an initial amount of power to the DFH heater that is dependent at least in part on the determined number of servo sectors, and decrease the initially-applied amount of power applied to the DFH heater until a predetermined target power is reached.
    Type: Grant
    Filed: January 31, 2014
    Date of Patent: January 5, 2016
    Assignee: Western Digital Technologies, Inc.
    Inventor: Huanxiang Ruan
  • Patent number: 9123370
    Abstract: A data storage device is disclosed comprising a disk, a head comprising a laser, and a fly height actuator (FHA) configured to actuate the head vertically over the disk based on an FHA setting. A first fly height of the head is measured at a first laser power setting, and a second fly height of the head is measured at a second laser power. A FHA write setting is generated based on a calibrated write laser power, the first and second fly height measurements, and a first function representing a nominal FHA delta setting between a read touchdown FHA setting and a write touchdown FHA setting relative to a delta in a fly height of the head due to a corresponding change in laser power applied to the laser, where the FHA write setting is applied to the FHA during the write operation.
    Type: Grant
    Filed: December 19, 2014
    Date of Patent: September 1, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Huanxiang Ruan, Galvin T. Chia
  • Patent number: 8976633
    Abstract: A data storage device is disclosed comprising a disk, a head comprising a laser configured to heat the disk while writing data to the disk, and a fly height actuator (FHA) configured to actuate the head vertically over the disk based on an FHA setting. A write laser power applied to the laser during a write operation is calibrated, a first fly height of the head is measured at a first laser power setting, and a second fly height of the head is measured at a second laser power setting different from the first laser power setting. A FHA write setting is generated based on the calibrated write laser power and the first and second fly height measurements, where the FHA write setting is applied to the FHA during the write operation.
    Type: Grant
    Filed: April 15, 2014
    Date of Patent: March 10, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Huanxiang Ruan, Galvin T. Chia
  • Patent number: 8922929
    Abstract: A disk drive is disclosed comprising a disk, a head comprising a laser operable to heat the disk while writing data to the disk, and a fly height actuator (FHA) operable to actuate the head vertically over the disk. A laser power applied to the laser during a write operation is calibrated, and a FHA write setting is generated for the FHA as a function of the calibrated laser power.
    Type: Grant
    Filed: June 25, 2013
    Date of Patent: December 30, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Huanxiang Ruan, Galvin T. Chia, Poornima Nookala
  • Patent number: 8902718
    Abstract: A disk drive is disclosed comprising a disk and a head actuated over the disk, the head comprising a fly height actuator (FHA). The disk drive further comprises control circuitry including disk access circuitry, wherein during a calibration operation, the disk access circuitry is configured into a calibration mode that increases a heating of the head, and a fly height of the head is measured periodically to generate periodic fly height measurements that vary due to the heating of the head. A dynamic fly height (DFH) write profile is generated based on the periodic fly height measurements. During a write operation, the disk access circuitry is configured into a write mode and a DFH control signal is generated and applied to the FHA based on the DFH write profile.
    Type: Grant
    Filed: June 3, 2013
    Date of Patent: December 2, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Huanxiang Ruan, Pradeep K. Thayamballi, Galvin T. Chia
  • Publication number: 20140347965
    Abstract: A disk drive is disclosed comprising a disk and a head actuated over the disk, the head comprising a fly height actuator (FHA). The disk drive further comprises control circuitry including disk access circuitry, wherein during a calibration operation, the disk access circuitry is configured into a calibration mode that increases a heating of the head, and a fly height of the head is measured periodically to generate periodic fly height measurements that vary due to the heating of the head. A dynamic fly height (DFH) write profile is generated based on the periodic fly height measurements. During a write operation, the disk access circuitry is configured into a write mode and a DFH control signal is generated and applied to the FHA based on the DFH write profile.
    Type: Application
    Filed: June 3, 2013
    Publication date: November 27, 2014
    Inventors: HUANXIANG RUAN, PRADEEP K. THAYAMBALLI, GALVIN T. CHIA
  • Patent number: 8773807
    Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of normal servo tracks each comprising a plurality of normal servo sectors storing head position information, and a fly height calibration servo track comprising fly height calibration servo sectors, each fly height calibration servo sector comprising head position information and a spacing pattern. After positioning the head over the fly height calibration servo track, the head is servoed over the fly height calibration servo track in response to the fly height calibration servo sectors. A dynamic fly height (DFH) setting is calibrated for the DFH actuator in response to the spacing pattern in the fly height calibration servo sectors. After calibrating the DFH setting, the control circuitry seeks the head to a data track defined by at least one of the normal servo tracks, and startup data is read from the data track.
    Type: Grant
    Filed: July 24, 2012
    Date of Patent: July 8, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Galvin T. Chia, Huanxiang Ruan
  • Patent number: 8576506
    Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of servo sectors defining a plurality of servo tracks. The servo tracks form a plurality of servo zones. A disk locked clock is synchronized relative to a servo data rate of the servo zone the head is over. A first reader/writer gap is measured in cycles of the disk locked clock at a first servo track in the first servo zone. A second reader/writer gap is measured in cycles of the disk locked clock at a second servo track in the second servo zone. The first and second reader/writer gaps are normalized to generate a normalized first and second reader/writer gaps. A third reader/writer gap is estimated in cycles of the disk locked clock at a third servo track in the second servo zone based on the normalized first and second reader/writer gaps.
    Type: Grant
    Filed: June 21, 2012
    Date of Patent: November 5, 2013
    Assignee: Western Digital Technologies, Inc.
    Inventors: Honge Wang, Michael Chang, Abhishek Dhanda, Huanxiang Ruan, Guoxiao Guo