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:
Mar. 10, 1998
Filed:
Apr. 25, 1996
Applicant:
Inventors:
Yo Sawamura, Kyoto, JP;
Yasuyuki Ohnishi, Kyoto, JP;
Assignee:
Rohm Co., Ltd., Kyoto, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
360 7311 ; 360 7308 ; 360 7309 ; 318608 ;
Abstract
A motor control circuit generates a signal representing a rotation frequency of a motor. It produces a motor speed error signal based on the rotation frequency. The error signal is changed by a speed gain circuit and supplied to the motor driving circuit through a filter. The filter is for preventing an oscillation in a servo loop. When the motor speed is out of a predetermined range, a gain of the speed error signal is reduced and the filter is disabled.