Patents by Inventor Tsz Lok Cheng

Tsz Lok Cheng 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).

  • Performance test method of head gimgal assembly with precise positioning actuator
    Patent number: 6989949
    Abstract: A method of testing a performance of the HGA has a step of writing information from the at least one thin-film magnetic head element onto a magnetic disk with driving the actuator for displacement by applying an alternating drive signal to the actuator, a step of reading out the information of at least one rotation of the magnetic disk by the at least one thin-film magnetic head element without driving the actuator for displacement, a step of storing the information read-out from the magnetic disk as a read-out information along a disk-rotating direction, a step of moving the HGA toward an off-track direction by a predetermined distance, a step of repeatedly executing the reading, storing and moving steps to obtain two-dimensional read-out information along the disk-rotating direction and the off-track direction, and a step of determining, from the two-dimensional read-out information, an off-track position where the read-out information becomes maximum at each position along the disk-rotating direction, the
    Type: Grant
    Filed: January 17, 2003
    Date of Patent: January 24, 2006
    Assignees: SAE Magnetics (H.K.) Ltd., TDK Corporation
    Inventors: Tsz Lok Cheng, Tamon Kasajima, Masashi Shiraishi, Katsuhiko Tomita, Takashi Honda, Takeshi Wada
  • Performance test method of head gimbal assembly with precise positioning actuator
    Publication number: 20030103284
    Abstract: A method of testing a performance of the HGA has a step of writing information from the at least one thin-film magnetic head element onto a magnetic disk with driving the actuator for displacement by applying an alternating drive signal to the actuator, a step of reading out the information of at least one rotation of the magnetic disk by the at least one thin-film magnetic head element without driving the actuator for displacement, a step of storing the information read-out from the magnetic disk as a read-out information along a disk-rotating direction, a step of moving the HGA toward an off-track direction by a predetermined distance, a step of repeatedly executing the reading, storing and moving steps to obtain two-dimensional read-out information along the disk-rotating direction and the off-track direction, and a step of determining, from the two-dimensional read-out information, an off-track position where the read-out information becomes maximum at each position along the disk-rotating direction, the
    Type: Application
    Filed: January 17, 2003
    Publication date: June 5, 2003
    Inventors: Tsz Lok Cheng, Tamon Kasajima, Masashi Shiraishi, Katsuhiko Tomita, Takashi Honda, Takeshi Wada