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:
Feb. 03, 2004
Filed:
Aug. 27, 2001
Applicant:
Inventor:
Hiroyuki Hagiwara, Tochigi, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 1/920 ; G11B 1/546 ;
U.S. Cl.
CPC ...
G11B 1/920 ; G11B 1/546 ;
Abstract
To correct the rotational balance of a spindle motor for rotating a disc on a base, a position and an amount of offset for correcting dynamic balance are determined from a position deviation signal, which is obtained from vibration transmitted to a rotary type position control unit located on the base similarly by lowering the servo gain thereof, and an index signal from the spindle motor. With this arrangement the dynamic balance of the spindle motor of an information recording/reproducing apparatus can be simply and accurately corrected without adding an accelerator sensor and the like.