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:
Dec. 03, 1985
Filed:
Mar. 09, 1981
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
369 45 ; 369 46 ; 369112 ; 369121 ;
Abstract
In an information recording apparatus for recording predetermined information on a recording medium by means of a laser beam, an optical system and a light detector are arranged for detecting a reflected version of the laser beam from the recording medium, whereby the focusing of the laser beam on the recording medium is automatically controlled.