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:
Mar. 22, 1994
Filed:
Nov. 29, 1991
Applicant:
Inventors:
Tsuyoshi Itoh, Tokyo, JP;
Isao Okuda, Tokyo, JP;
Toshiyuki Kase, Tokyo, JP;
Hiroshi Nishikawa, Tokyo, JP;
Ryoto Ogawa, Tokyo, JP;
Masahiro Oono, Tokyo, JP;
Koichi Maruyama, Tokyo, JP;
Makoto Iki, Tokyo, JP;
Isao Takahashi, Tokyo, JP;
Assignee:
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4432 ; 369 4425 ; 369 4429 ; 369 4435 ; 2502015 ;
Abstract
In the magneto-optic recording/reproduction apparatus, a light beam from a semiconductor laser that can be used with two wavelengths, for recording and reproduction is converged by an objective lens on a magneto-optic disk, a predetermined offset is added to this focusing error signal by an offset adjusting circuit, and the objective lens is driven in the direction of the optical axis based on the focusing error signal to which an offset was added.