The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 21, 2003
Filed:
Nov. 19, 1999
Masato Sakamoto, Kawagoe, JP;
Katsunori Tamamura, Kawagoe, JP;
Kazuhiko Oogami, Kawagoe, JP;
Norikazu Tada, Tendo, JP;
Atsushi Kusaka, Tendo, JP;
Akihito Fujiwara, Tendo, JP;
Mayumi Takahashi, Kawagoe, JP;
Other;
Abstract
An apparatus for driving an optical pickup for a tracking servo control. The apparatus includes an emitting device disposed in the optical pickup for emitting a main beam to a first position on an information track of a recording medium and emitting at least two subsidiary beams to a second position and a third position on the information track of the recording medium, respectively. The positions of the main beam and the subsidiary beams are determined appropriately for a three beam method. The apparatus further includes: a tracking error signal generating device for generating a tracking error signal using returned light beams of the subsidiary beams from the recording medium; a driving device for moving the first position of the main beam and the second position and the third position of the subsidiary beams with respect to the recording medium; a tracking control device for outputting a driving signal based on the tracking error signal to the driving device; and a detecting device for detecting a damaged part on the recording medium. The tracking control device generates a pulse signal having a polarity opposite to a disturbance part of the driving signal generated due to at least one of the subsidiary beams passing on the damaged part, and uses this pulse signal as a part of the driving signal.