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:
Jan. 26, 1988
Filed:
Jul. 31, 1985
Applicant:
Inventor:
Keiichi Matsumoto, Saitama, JP;
Assignee:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 44 ; 369 45 ; 250201 ;
Abstract
In a three-beam type optical data disk player, beam output disturbances due to an external disturbance such as vibration and the beam output disturbances due to a local defect on the disk are distinguished from each other, and the servo gain is adjusted according to whether the beam output disturbance is due to the external disturbance or due to the local defect, so that the main beam is controlled to correctly follow the track at all times.