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. 01, 2002
Filed:
Apr. 11, 2000
Applicant:
Inventors:
Hideshi Mochizuki, Kawasaki, JP;
Hiroshi Kumita, Higashichikuma-gun, JP;
Shigenori Yanagi, Kawasaki, JP;
Tomoki Yokoyama, Higashine, JP;
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P 6/02 ;
U.S. Cl.
CPC ...
H02P 6/02 ;
Abstract
This invention relates to a control method, control device, and drive circuit for controlling the rpm of a spindle motor in order to reduce the rise time of the spindle motor. There is a discharge circuit ( - ) in the charge pump ( ) of a spindle-motor driver ( ). A control circuit ( ) detects when the rpm of the spindle motor reaches near a target rpm, and discharges the charge pump ( ). In this way, the rotation error near the target rpm is discharged, so it is possible to control and suppress overshoot. This makes it possible to reduce the rise time.