Patents by Inventor Lan V. Ngo

Lan V. Ngo 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).

  • Publication number: 20200372931
    Abstract: A data storage device is disclosed comprising a first disk comprising a first disk surface, a second disk comprising a second disk surface, an actuator arm, a head coupled to a distal end of the actuator arm, and a ramp for loading/unloading the head. A first elevator actuator is configured to actuate the actuator arm along an axial dimension relative to the first and second disks, and a second elevator actuator is configured to actuate at least part of the ramp along the axial dimension, wherein a simultaneous movement of the first and second elevator actuators is synchronized.
    Type: Application
    Filed: March 2, 2020
    Publication date: November 26, 2020
    Inventors: Kuang-Yang Tu, Jenghung Chen, Lan V. Ngo
  • Patent number: 10839838
    Abstract: A data storage device is disclosed comprising a first disk comprising a first disk surface, a second disk comprising a second disk surface, an actuator arm, a head coupled to a distal end of the actuator arm, and a ramp for loading/unloading the head. A first elevator actuator is configured to actuate the actuator arm along an axial dimension relative to the first and second disks, and a second elevator actuator is configured to actuate at least part of the ramp along the axial dimension, wherein a simultaneous movement of the first and second elevator actuators is synchronized.
    Type: Grant
    Filed: March 2, 2020
    Date of Patent: November 17, 2020
    Assignee: Western Digital Technologies, Inc.
    Inventors: Kuang-Yang Tu, Jenghung Chen, Lan V. Ngo
  • Patent number: 10622012
    Abstract: A data storage device is disclosed comprising a first disk comprising a first disk surface, a second disk comprising a second disk surface, an elevator actuator configured to actuate a head along an axial dimension relative to the first and second disks, a radial actuator configured to actuate the head radially over the first disk surface or the second disk surface, and a position sensor configured to generate a sinusoidal sensor signal representing a position of the head along the axial dimension. A crashstop_offset along the axial dimension is measured from a crashstop position of the elevator actuator to a zero crossing of the sinusoidal sensor signal.
    Type: Grant
    Filed: June 6, 2019
    Date of Patent: April 14, 2020
    Assignee: Western Digital Technologies, Inc.
    Inventors: Kuang-Yang Tu, Jenghung Chen, Lan V. Ngo
  • Patent number: 7023640
    Abstract: A disk drive comprising a first sensor mounted on a nominally stationary portion of the disk drive and adapted to detect acceleration disturbances of the disk drive. The disk drive further comprising: a dual-function subsystem having a first circuit adapted to provide a write-inhibit signal and a second circuit adapted to provide a feed-forward basis signal, the dual-function subsystem adapted to receive a first sensor signal from the first sensor and to provide (a) the write-inhibit signal based on the received first sensor signal and a first threshold value, and (b) the feed-forward basis signal based on the received first sensor signal.
    Type: Grant
    Filed: May 27, 2004
    Date of Patent: April 4, 2006
    Assignee: Western Digital Technologies, Inc.
    Inventors: Raffi Codilian, Lan V. Ngo, Norman D. Gardner
  • Patent number: 6952318
    Abstract: A method for reducing the effects of rotational vibration in a disk drive comprising generating a self-induced vibration in the disk drive, and sensing the self-induced vibration in the first and second sensors and generating a corresponding first and second sensor data. The method further comprises comparing the first and second sensor data to determine a gain-differential, and scaling at least one of the first and second sensor data to reduce the gain-differential between the first and second sensors.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: October 4, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventor: Lan V. Ngo
  • Patent number: 6937423
    Abstract: A method of reducing rotational vibration effects in a disk drive by sensing vibration in a sensor and generating corresponding sensor data; deriving a statistical sensor (SS) value based on the sensor data; deriving a statistical position error signal (SPES) value from servo sectors read by the head; comparing the SS value to a SS-threshold value; comparing SPES value to a SPES-threshold value; and generating a feed-forward command effort signal for reducing rotational vibration effects if the SS value exceeds the SS-threshold value and if SPES value exceeds the SPES-threshold value.
    Type: Grant
    Filed: February 6, 2004
    Date of Patent: August 30, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventors: Lan V. Ngo, Raffi Codilian
  • Patent number: 6914743
    Abstract: Disclosed is a disk drive using an accelerometer to sense linear vibration and cancel its effects with an adaptive algorithm during track following. The accelerometer is oriented to detect acceleration associated with torque that tends to cause the actuator to move off-track notwithstanding the efforts of the servo control system. The accelerometer's filtered output is used to modify the control effort. The disk drive uses the position error signal to adaptively filter the accelerometer's output in an effort to mathematically converge on a set of optimal filter coefficients and thereby reduce the effect of vibration that may otherwise impose a torque on the actuator.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: July 5, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventors: Aswartha Narayana, Raffi Codilian, Lan V. Ngo
  • Patent number: 6710966
    Abstract: The present invention may be embodied in a method, implemented in a disk drive, for adaptively reducing an effect of vibration during a track following operation. The disk drive includes a disk and a rotary actuator. The disk includes distributed position information in a plurality of servo wedges. The actuator carries a transducer and pivots on a base of the disk drive. The actuator may exhibit an imbalance that may be affected by a linear vibration. In the method, a sensor signal is generated that is responsive to a vibration to the disk drive. The sensor value is modified based on an adaptive-filter gain to generate a position error adjustment signal for modifying a nominal position error signal. The adaptive-filter gain is then altered based on an adjusted position error signal and the sensor value associated with the current servo wedge for use during a next servo wedge.
    Type: Grant
    Filed: October 23, 2001
    Date of Patent: March 23, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Raffi Codilian, Aswartha Narayana, Lan V. Ngo