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:
Oct. 24, 1995
Filed:
Jan. 06, 1994
Applicant:
Inventors:
Yoshito Asoma, Saitama, JP;
Yoshiyuki Matsumoto, Tokyo, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
2502015 ; 369 4441 ;
Abstract
In an optical pick-up device, a first photodetector is disposed in such a position as to detect a light beam which is part of a light beam reflected from an optical disk and split in a direction different from a light source direction, and a second photodetector is disposed in the vicinity of the light source so that it can detect a light beam which is the other part of the light beam reflected from the optical disk and split in the light source direction, wherein a tracking control signal and a reproducing signal are detected by the first photodetector and a focusing control signal is detected by the second photodetector.