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:
Apr. 09, 1991
Filed:
Aug. 01, 1988
Applicant:
Inventors:
Kazuhiko Nakane, Amagasaki, JP;
Teruo Furukawa, Amagasaki, JP;
Masayoshi Shimamoto, Amagasaki, JP;
Kyosuke Yoshimoto, Amagasaki, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4411 ; 369 4436 ;
Abstract
When recording, reproducing or erasing data signal by illuminating a recording medium surface with a condensed light spot, a tracking sensor signal or a focusing sensor signal is detected from light reflected from the recording medium surface. The detected signal is subjected to current-to-voltage conversion, and the current-to-voltage conversion gain is switched by estimating reflected light power from the recording medium surface.