Patents Represented by Attorney, Agent or Law Firm MacPherson Kwok Ohen & Heid LLP
  • Patent number: 6781929
    Abstract: A servo system with a multi-track seek algorithm is presented. The multi-track seek algorithm detects zero crossings in a tracking error signal, counts the number of zero crossings to form a count, and calculates a reference velocity from the count. The algorithm also determines a time period between successive zero crossings, calculates a velocity from the time period, calculates a difference signal between the reference velocity and the velocity, and adjusts the control signal so that the velocity follows the reference velocity. The reference velocity can follow a velocity profile with acceleration portions, coasting portions, and deceleration portions which move an optical pick-up unit from a starting position to a target position.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: August 24, 2004
    Assignee: DPHI Acquisitions, Inc.
    Inventor: Ron J. Kadlec