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:
Jul. 04, 1995
Filed:
Feb. 23, 1994
Applicant:
Inventors:
Akira Matsubara, Kameoka, JP;
Takao Hayashi, Katano, JP;
Yutaka Murakami, Katano, JP;
Toru Nakamura, Katano, JP;
Hideki Aiko, Osaka, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4432 ; 369 54 ;
Abstract
The relative tilt of an optical disk and a movable objective lens holder is measured as an output of a differential amplifier which subtracts an output of first photodetectors and which detect the reflected light from optical disk from an output of second photodetectors and which detect the reflected light from a reflector mounted on movable objective lens holder. The signal from differential amplifier is used to tilt movable objective lens holder so that the movable objective lens holder compensates the tilt of optical disk.