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:
Oct. 12, 1993
Filed:
Nov. 16, 1990
Applicant:
Inventors:
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4428 ; 369 4429 ; 369 4432 ; 369 54 ;
Abstract
A tracking control apparatus is disclosed, in which a light beam is focused on an optical recording medium to form a light spot thereon, and a tracking error signal corresponding to a maximum or minimum point of total reflected light from a portion of the optical recording medium, which is irradiated by the light spot, is detected and used as a desired value for tracking servo control, whereby accurate tracking servo control can be made without producing any offset even when the surface of the optical recording medium is inclined or the optical axis of the light reflected from the optical recording medium deviates from a proper direction.