Patents by Inventor Satoshi Senba

Satoshi Senba 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).

  • Optical device with improved focused error detection and tracing error detection for optical disk drive
    Patent number: 5754503
    Abstract: An optical device for an optical disk drive, for performing focusing error detection and tracking error detection of a laser beam converged on an optical disk. The optical device includes a diffraction grating having first, second, third, and fourth regions for diffracting a reflected beam from the optical disk in different directions. The optical device further includes a first photodetector for detecting a part of the reflected beam diffracted by the first region of the diffraction grating, a second photodetector for detecting a part of the reflected beam diffracted by the second region of the diffraction grating, a third photodetector for detecting a part of the reflected beam diffracted by the third region of the diffraction grating, and a fourth photodetector for detecting a part of the reflected beam diffracted by the fourth region of the diffraction grating.
    Type: Grant
    Filed: November 14, 1996
    Date of Patent: May 19, 1998
    Assignee: Fujitsu Limited
    Inventors: Satoshi Senba, Shinya Hasegawa, Hiroyasu Yoshikawa, Fumihiro Tawa