Patents by Inventor Wen-Jun Cao

Wen-Jun Cao 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).

  • Soft sensor for operating shock in a disc drive
    Patent number: 7349174
    Abstract: A method of preventing a write operation to a disc in a disc drive during a shock event without the use of a separate shock sensor comprises steps of monitoring an actuator voice coil motor (VCM) control plant output signal, generating an actuator voice coil motor (VCM) plant model module output signal, comparing the VCM plant model module output signal to the VCM control plant module output signal to produce a difference signal, and triggering a write protect gate if the difference signal exceeds a predetermined threshold value.
    Type: Grant
    Filed: May 9, 2002
    Date of Patent: March 25, 2008
    Assignee: Seagate Technology LLC
    Inventors: Qiang Bi, Xiong Liu, LeeLing Tan, Wen-Jun Cao, ChoonKiat Lim
  • Soft sensor for operating shock in a disc drive
    Publication number: 20030103286
    Abstract: A method of preventing a write operation to a disc in a disc drive during a shock event without the use of a separate shock sensor comprises steps of monitoring an actuator voice coil motor (VCM) control plant output signal, generating an actuator voice coil motor (VCM) plant model module output signal, comparing the VCM plant model module output signal to the VCM control plant module output signal to produce a difference signal, and triggering a write protect gate if the difference signal exceeds a predetermined threshold value.
    Type: Application
    Filed: May 9, 2002
    Publication date: June 5, 2003
    Applicant: Seagate Technology LLC
    Inventors: Qiang Bi, Xiong Liu, LeeLing Tan, Wen-Jun Cao, ChoonKiat Lim