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. 05, 1994
Filed:
Sep. 28, 1992
Applicant:
Inventors:
Itaru Suzuki, Miyagi, JP;
Hajima Yano, Kanagawa, JP;
Hiroyuki Wakasugi, Miyagi, JP;
Kaoru Nakajima, Miyagi, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; G01J / ;
U.S. Cl.
CPC ...
369 4426 ; 369110 ; 369 13 ; 2502015 ;
Abstract
A magneto-optical disc system and a medium used therewith are disclosed in which a magneto-optical disk having a magneto-optical recording layer on one major surface with a protective film formed on said magneto-optical recording layer, on which a magnetic head is slid, and an optical system having a focus servo mechanism on the other surface. The focus servo mechanism of the optical system satisfies a certain condition to avoid any focal blank.