Patents by Inventor Choonkiat Lim

Choonkiat Lim 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: 20020101688
    Abstract: A disc drive having an actuator assembly which includes an actuator arm and having a pivot cartridge which consists of a sleeve, a shaft and a hinge. The hinge is thin and short in the horizontal direction along the x-y plane and long in the vertical direction along the z-axis. The hinge engages the sleeve and the shaft with the ends of the hinge, allowing only the central part of the hinge configured to be flexible. The assembly of the pivot cartridge into the actuator assembly forces the actuator arm to rotate only about the z-axis.
    Type: Application
    Filed: December 1, 2000
    Publication date: August 1, 2002
    Inventors: Joseph Cheng-Tsu Liu, Xiong Liu, Michael Joo Chiang Toh, Choonkiat Lim, Kevin Arthur Gomez
  • Publication number: 20020064000
    Abstract: An actuator having a relatively low mass for supporting flexible head suspension assemblies to read data from or write data to discs. The actuator includes an actuator body adapted to rotationally coupled to a base chassis of the disc drive and a yoke assembly including yoke arms extending from the actuator body. The actuator includes at least one rigid actuator arm rigidly supporting the flexible head suspension assemblies. The rigid actuator arm includes multiple arm plates supported in spaced relation to provide a thickness of the actuator arm for lateral stiffness.
    Type: Application
    Filed: June 29, 2001
    Publication date: May 30, 2002
    Inventors: Xiong Liu, Shri Hari Narayan, Michael Joo Chiang Toh, Choonkiat Lim, ChorShan Cheng
  • Publication number: 20020039248
    Abstract: Steps for isolating and correcting total written-in repeatable run-out error written into servo sectors of a disc drive include, determining a total repeatable run-out error value for each servo sector, isolating a repeatable error value component of the total written-in repeatable run-out error value for each servo sector, removing the repeatable error value component from total written-in repeatable run-out error value to provide a non-repeatable error value component of the total written-in repeatable run-out error value for each servo sector, providing both the repeatable and non-repeatable error value components to a processor for generation of compensation signals, and applying the compensation signals into a servo control circuit of control loop of the disc drive using compensation circuits to compensate for each component of the total written-in repeatable run-out error.
    Type: Application
    Filed: June 19, 2001
    Publication date: April 4, 2002
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xiong Liu, Kian Keong Ooi, ChoonKiat Lim, Yangquan Chen, Qiang Bi, Mingzhong Ding, ShuangQuan Min, WeiSung Lee
  • Publication number: 20020036858
    Abstract: A disc drive including rotatable disc surface adjacent a positionable read/write head having a write element offset from a read element in one direction across the rotatable disc surface from an outer diameter of the disc surface to an inner diameter of the disc surface for writing head position control fields by steps for controlling writing of second head position control fields on a second portion of the disc surface while reading head position control fields written on a first portion of the disc surface, using the read element, to augment position-control of the write element being controlled by a position information writing apparatus, while writing the second head position control field to the second portion of the disc surface.
    Type: Application
    Filed: April 30, 2001
    Publication date: March 28, 2002
    Applicant: Seagate Technology LLC
    Inventors: Qiang Bi, Xiong Liu, Kevin A. Gomez, Jimmy T. Pang, ChoonKiat Lim
  • Publication number: 20010053041
    Abstract: A disc clamp made from a shape memory alloy is configured for tight fit between an upper ledge of a spindle hub and the upper surface of a disc when the disc clamp is in an austenitic phase. In a martensitic phase, the disc clamp is configured for easy assembly over the spindle hub. The disc of the present invention provides for uniform distribution of clamping forces on the disc, and avoids the need for threaded holes in the spindle hub.
    Type: Application
    Filed: May 19, 2001
    Publication date: December 20, 2001
    Inventors: Quock Ying Ng, Xiong Liu, Choonkiat Lim
  • Publication number: 20010040770
    Abstract: A disc drive having a pivot cartridge and an actuator assembly. The actuator assembly consists of an actuator body which has a bore therein to receive the pivot cartridge. The actuator body further consists of an opening which serves as a ledge to engage a biased retaining ring. The biased retaining ring couples onto the pivot cartridge and forces the pivot cartridge to contact against one side of the bore of the actuator body.
    Type: Application
    Filed: January 9, 2001
    Publication date: November 15, 2001
    Inventors: Michael Joo Chiang Toh, Xiong Liu, Joseph Cheng-Tsu Liu, Choonkiat Lim
  • Patent number: 6308555
    Abstract: Embodiments of apparatus are directed to a rotational shock tester system comprising a disc drive support system, a drop mechanism and an impact apparatus. The disc drive support system includes a rotation plate, wherein a disc drive is coupled to the rotation plate. The drop mechanism is coupled to the disc drive support system and includes an elevating apparatus, wherein the elevating apparatus elevates and releases the rotation plate which is supporting the disc drive. The impact apparatus is releasably coupled to the drop mechanism and is aligned with the rotation plate such that upon release of the rotation plate, the rotation plate impacts the impact apparatus such that the impact apparatus imparts an angular acceleration to the rotation plate and imparts a rotational shock to the disc drive.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: October 30, 2001
    Assignee: Seagate Technology LLC
    Inventors: Andre Y. Liem, Joseph C. Liu, ChoonKiat Lim, Sen Chai Khew