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.

Date of Patent:
Aug. 20, 2002

Filed:

Dec. 02, 1999
Applicant:
Inventors:

Tadashi Takeda, Nagano, JP;

Yoshio Hayashi, Nagano, JP;

Taminori Masuzawa, Nagano, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/00 ;
U.S. Cl.
CPC ...
G11B 7/00 ;
Abstract

A returning light beam from an optical disc is divided by a separating diffractor in the directions perpendicular to a track direction of the optical recording medium, and according to respective illuminances of the divided light beams, a deviation amount of an objective lens to an optical axis is detected. By feedback-controlling an objective lens driver by using the information of the detected deviation amount, the objective lens can be made to become stationary at the desired position in a short time. Accordingly, a time period required for the oscillation attenuation of the objective lens can be shortened, thereby, a time period for the reproduction can be shortened.


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