Patents by Inventor Quan-Chiu Lam

Quan-Chiu Lam 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: 20180012627
    Abstract: A method may include causing a write head of a magnetic data storage drive to write a first portion of data to a magnetic data storage device of the magnetic data storage drive based at least in part on a first value of at least one parameter of a write current. The method may include updating a value of a write counter and determining whether the value of the write counter is greater than or equal to a threshold write count. The method may also include adjusting the at least one parameter of the write current to a second, different value. The method may further include causing the write head to write a second portion of data to the magnetic data storage device based at least in part on the second value of the at least one parameter of the write current.
    Type: Application
    Filed: July 7, 2016
    Publication date: January 11, 2018
    Inventors: Mark Hutcheson Burkhardt, Venkatesh Chembrolu, Zhaohui Chen, Quan-Chiu Lam, Supradeep Narayana
  • Publication number: 20060114587
    Abstract: A method is presented for writing data to a surface of a magnetic disk in a disk drive. The method includes determining a number of sector groups into which sectors of the data to be written will be grouped, loading registers with current values, kick-latching values, and precompensation values for each of said sector groups, and applying the current values, kick-latching values, and precompensation values for each of the sector groups to the write head while writing data to the sector groups of the recording media.
    Type: Application
    Filed: November 30, 2004
    Publication date: June 1, 2006
    Inventors: Indukumar Kalahasthi, Quan-chiu Lam, Guo Mian, Kris Schouterden, Joseph Silva, Christopher Wiederholt, Douglas Zuercher
  • Publication number: 20050264930
    Abstract: A method and apparatus for providing a write head with an improved pole tip to improve overwrite and/or adjacent track interference. A cross pole tip writer is provided with a shape that is designed to reduce the saturation on the pole tip and aid in the concentration of flux to the down track.
    Type: Application
    Filed: May 28, 2004
    Publication date: December 1, 2005
    Inventors: Savas Gider, Wen-Chien Hsiao, Quan-chiu Lam, Terence Lam, Edward Hin Lee, Yansheng Luo, Vladimir Nikitin, Changqing Shi, Xiaoyu Sui
  • Publication number: 20050120544
    Abstract: A pole piece of a magnetic write head is formed over a substrate and includes a pole tip having a width that is less than its height which is normal the substrate. Due to stress-anisotropy, the pole tip structure has an inherent easy-axis which is oriented in an unfavorable direction (i.e. perpendicular to the ABS and almost collinear with a driving field of the write head). To alleviate this problem, during electroplating or annealing of the pole piece a magnetic field is applied to the pole tip in a direction which is out-of-plane from the substrate but in-plane with a side wall of the pole tip which vertically projects from the substrate. By applying the magnetic field in this manner, the easy axis of the pole piece is oriented in the direction of the applied magnetic field to facilitate more efficient switching in the write head. Ideally, the angle ? is about 90° for Hexagonal-Closed Packed (HCP) materials or about 50° for Face-Centered Cubic or Body-Centered Cubic (BCC) materials (e.g. NiFe and CoFe).
    Type: Application
    Filed: December 8, 2003
    Publication date: June 9, 2005
    Inventor: Quan-Chiu Lam
  • Publication number: 20050024768
    Abstract: An apparatus for providing transverse magnetic bias proximate to a pole tip to speed up the switching time of the pole-tip during the writing operation is disclosed. The transverse field disposed proximate the pole-tip helps the conventional driving field in rotating the magnetization through the first 90-degrees, especially at small angle where the effective anisotropy-field is strongest in opposing the conventional driving field. By offsetting the magnetization from its easy-axis, the transverse field also increases the torque that the collinear driving field would have on the magnetization.
    Type: Application
    Filed: July 28, 2003
    Publication date: February 3, 2005
    Inventor: Quan-Chiu Lam
  • Publication number: 20050024177
    Abstract: A method for providing transverse magnetic bias proximate to a pole tip to speed up the switching time of the pole-tip during the writing operation is disclosed. The transverse field disposed proximate the pole-tip helps the conventional driving field in rotating the magnetization through the first 90-degrees, especially at small angle where the effective anisotropy-field is strongest in opposing the conventional driving field. By offsetting the magnetization from its easy-axis, the transverse field also increases the torque that the collinear driving field would have on the magnetization.
    Type: Application
    Filed: July 28, 2003
    Publication date: February 3, 2005
    Inventor: Quan-Chiu Lam
  • Publication number: 20050018347
    Abstract: The magnetic head is formed with a narrow pole tip, and a pole tip heating element is fabricated to reduce the pole tip stress and increase its permeability, such that the magnetization switching speed of the pole tip is increased. The heating element is preferably electrically interconnected within the induction coil circuit of the magnetic head, such that the electrical current flowing through the induction coil also flows through the heating element. In a preferred embodiment, the heating element is fabricated above the second magnetic pole. The heating element is preferably formed with a resistance of approximately 0.2 to 1.0 ohms, such that the approximately 40 mA current that flows through the induction coil and the heating element creates a heating energy of the heating element of approximately 0.3 to 1.6 mW. The heating element can be comprised of a variety of materials such as Cu, W, NiFe, NiCr and IrRh.
    Type: Application
    Filed: July 21, 2003
    Publication date: January 27, 2005
    Inventors: Wen-Chien Hsiao, Quan-Chiu Lam