Patents by Inventor Sung Gul Lee

Sung Gul Lee 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).

  • Patent number: 8149658
    Abstract: A method and device for erasing data from an optical disc, are discussed. In an embodiment of the present invention, the area of the optical disc where data has been written is overwritten with arbitrary data using a beam spot spanning over two or more radially adjacent tracks. The beam spot can be formed by adjusting a location of an objective lens to a defocused location, and the power of the laser beam can be increased so as to maintain a certain power level. The beam spot is moved from the inner circumference of the optical disc to the outer circumference under feed-forward control over an actuator and a sled motor, in which case the beam spot may be moved sequentially toward the outer circumference in steps of beam spot size or be moved repeatedly across radially adjacent tracks in a zigzag manner by the actuator and/or the sled motor.
    Type: Grant
    Filed: November 13, 2007
    Date of Patent: April 3, 2012
    Assignee: Hitachi-LG Data Storage Korea, Inc.
    Inventors: Hansuk Kim, Sung Gul Lee
  • Publication number: 20080130477
    Abstract: A method and device for erasing data from an optical disc, are discussed. In an embodiment of the present invention, the area of the optical disc where data has been written is overwritten with arbitrary data using a beam spot spanning over two or more radially adjacent tracks. The beam spot can be formed by adjusting a location of an objective lens to a defocused location, and the power of the laser beam can be increased so as to maintain a certain power level. The beam spot is moved from the inner circumference of the optical disc to the outer circumference under feed-forward control over an actuator and a sled motor, in which case the beam spot may be moved sequentially toward the outer circumference in steps of beam spot size or be moved repeatedly across radially adjacent tracks in a zigzag manner by the actuator and/or the sled motor.
    Type: Application
    Filed: November 13, 2007
    Publication date: June 5, 2008
    Applicant: HITACHI-LG DATA STORAGE KOREA, INC.
    Inventors: Hansuk Kim, Sung Gul Lee