Patents by Inventor Shuitsu Takeda

Shuitsu Takeda 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).

  • Techniques for controlling beam position and focus in optical disk drives
    Patent number: 5251194
    Abstract: An optical disk drive for recording and reproducing information on an optical disk medium includes a servo circuit for controlling tracking of a light beam on a predetermined track and a servo circuit for controlling focus of the light beam on the disk surface. The disk surface is divided into a plurality of regions, and calibration values for adjusting the servo circuits are determined in each region. The calibration values are stored in a memory and are used to adjust the servo circuits during tracking on a predetermined track. The calibration values include tracking offset values, focus offset values, servo deviation threshold values and sensor gain values. A number of techniques are disclosed for automatically determining the calibration values.
    Type: Grant
    Filed: April 12, 1990
    Date of Patent: October 5, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kyosuke Yoshimoto, Osamu Ito, Kimiyuki Koyanagi, Yoshiki Nakajima, Shuitsu Takeda, Kyoji Shimoda