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:
Jun. 05, 1984
Filed:
Aug. 14, 1981
Applicant:
Inventors:
Assignee:
Olympus Optical Company, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 45 ; 369 44 ; 369 46 ; 369112 ; 250201 ; 250204 ;
Abstract
An apparatus and method for recording optically an information signal on a disk-like record medium as a spiral track or concentrical tracks by modulating a main beam by the information signal to be recorded and projecting the modulated main beam onto the record medium. In order to obtain a tracking error signal, a sub beam is also projected on the record medium at an edge of an adjacent track which has been previously recorded and the sub beam reflected by the record medium is detected by a light detector to produce the tracking error signal which is then supplied to a high pass filter to remove a low frequency component from the tracking error signal.