Patents by Inventor Xiaokun Chew

Xiaokun Chew 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: 12046266
    Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The one or more processing devices are configured to apply a pre-bias current to the assistive energy emitter at a first value while the selected head is positioned proximate to one or more spiral patterns on the corresponding disk surface. The one or more processing devices are further configured to apply the pre-bias current to the assistive energy emitter at a boosted value while the selected head is not positioned proximate to the one or more spiral patterns, wherein the boosted value is greater than the first value.
    Type: Grant
    Filed: August 9, 2023
    Date of Patent: July 23, 2024
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Guoxiao Guo, Dan Wang, Yun Hong, Xiaokun Chew
  • Patent number: 7738206
    Abstract: A method and apparatus for providing an early warning of thermal decay in magnetic storage media are provided. In accordance with an embodiment of the present invention, a test pattern that is particularly susceptible to thermal decay is written to a disk. The test pattern is then read, and the amplitude of the signal produced by the test pattern is stored. When testing for thermal decay is desired, the test pattern is again read, and the amplitude of the signal produced in the channel is compared to the stored amplitude. If the later amplitude is less than the stored amplitude by at least a predetermined amount, a thermal decay warning signal is generated. In accordance with another embodiment of the present invention, a test pattern is written to a portion of a disk that has been identified as being particularly susceptible to thermal decay. The amplitude produced by the test pattern is then stored so that it can later be compared to an observed amplitude when testing for thermal decay.
    Type: Grant
    Filed: August 3, 2001
    Date of Patent: June 15, 2010
    Assignee: Seagate Technology LLC
    Inventors: G. Herbert Lin, Davidc Guarisco, Xiaokun Chew
  • Patent number: 7388726
    Abstract: A disk drive includes a slider assembly and a controller that directs current to the slider assembly to dynamically adjust the head-to-disk spacing. In one embodiment, the slider assembly includes a write element having a first end, a second end and an intermediate section, a conductor that is connected to the intermediate section. In this embodiment, the controller directs electrical current through the conductor to heat the write element without writing data to a storage disk. The electrical current can be directed through the conductor at any time prior to data transfer or during data transfer. Heating the write element causes a deformation of the slider assembly to decrease the head-to-disk spacing. In another embodiment, the slider assembly includes a separate slider deformer. Electrical current is selectively directed to the slider deformer to cause a deformation of the slider assembly to obtain a desired head-to-disk spacing.
    Type: Grant
    Filed: August 10, 2006
    Date of Patent: June 17, 2008
    Assignee: Seagate Technology LLC
    Inventors: Robert McKenzie, Thao Nguyen, Xiaokun Chew, Gang Herbert Lin, Jack Tsai, Bruce Schardt, Steven Marshall
  • Patent number: 7369345
    Abstract: A system provided for protecting a disk drive from impact damages. More specifically, a disk drive is provided that includes an accelerometer interconnected to a printed circuit board that detects free fall of the disk drive. In addition, the velocity of spinning disks of the disk drive is also monitored to assess changes in velocity thereof that may indicate the presence of a tumbling condition. Furthermore, the change in acceleration measured by the accelerometer is monitored to prevent false indications of free fall due to common vibrations. Thus an enhanced system is provided that protects disk drives from the effect of free falls under a wide variety of conditions and allowing for drops from shorter distances to be identified.
    Type: Grant
    Filed: December 2, 2005
    Date of Patent: May 6, 2008
    Assignee: Maxtor Corporation
    Inventors: Yunfeng Li, Erhard Schreck, Wei Guo, Tim Glassburn, Mark Heimbaugh, William Flynn, Oliver Northrup, John E. Scura, Lin Guo, Xiaokun Chew
  • Patent number: 7253980
    Abstract: Circuitry for detecting and recording latches in read bias current may include circuitry for generating a reference voltage, a pair of current to voltage converters to convert the bias and reference currents to voltage signals, a comparator to compare those two voltages, a latch to latch the compared signal, and a counter/register to count and store the number of glitches that have been detected. It may be possible to read from the register the number of detected glitches to be used in diagnosing faults in the disk drive system. In addition, it may be possible to provide a reset input to the register to zero the counter.
    Type: Grant
    Filed: June 3, 2005
    Date of Patent: August 7, 2007
    Assignee: Maxtor Corporation
    Inventors: Bac Pham, Xiaokun Chew
  • Patent number: 7092193
    Abstract: A disk drive includes a slider assembly and a controller that directs current to the slider assembly to dynamically adjust the head-to-disk spacing. In one embodiment, the slider assembly includes a write element having a first end, a second end and an intermediate section, a conductor that is connected to the intermediate section. In this embodiment, the controller directs electrical current through the conductor to heat the write element without writing data to a storage disk. The electrical current can be directed through the conductor at any time prior to data transfer or during data transfer. Heating the write element causes a deformation of the slider assembly to decrease the head-to-disk spacing. In another embodiment, the slider assembly includes a separate slider deformer. Electrical current is selectively directed to the slider deformer to cause a deformation of the slider assembly to obtain a desired head-to-disk spacing.
    Type: Grant
    Filed: August 2, 2002
    Date of Patent: August 15, 2006
    Assignee: Maxtor Corporation
    Inventors: Robert McKenzie, Thao Nguyen, Xiaokun Chew, Gang Herbert Lin, Jack Tsai, Bruce Schardt, Steven Marshall
  • Patent number: 6717757
    Abstract: A disk drive utilizes a unique write condition for each of the transducers within the drive. Each write condition is determined based upon the specific properties of the corresponding transducer. The write condition information is preferably stored within a memory within the disk drive. When a write operation is performed, the appropriate write condition for the corresponding transducer is used to determine when to write data to the disk. A write condition will typically include one or more individual write criteria. For example, a write condition can specify a write threshold value to be used during a write operation. Similarly, a write condition can involve a combination of a write threshold and a radial transducer velocity. Other write criteria are also possible.
    Type: Grant
    Filed: May 25, 2000
    Date of Patent: April 6, 2004
    Assignee: Maxtor Corporation
    Inventors: Llyod Levy, Don Brunnet, Xiaokun Chew