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:
Nov. 19, 1991
Filed:
Jun. 15, 1989
Applicant:
Inventor:
Tetsuya Wakui, Chiba, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
360 70 ; 360 7713 ;
Abstract
A rotation control device comprises a rotary body arranged to move a head and a recording medium relative to each other in performing recording or reproduction on or from the recording medium; means for performing speed servo-control by detecting any speed deviation of the rotary body; means for performing phase servo-control by detecting any phase deviation of the rotary body; and means for performing the speed servo-control over the rotary body by detecting a phase-locked state of the rotary body and by synchronizing the rotary body with a synchronizing signal reproduced from the recording medium.