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. 13, 2009
Filed:
Jul. 19, 2006
Katsumi Shirai, Kawasaki, JP;
Eiji Okamura, Kawasaki, JP;
Katsumi Shirai, Kawasaki, JP;
Eiji Okamura, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A motor drive control unit includes a chip in which everything about a control system is provided and controls a spindle motor which rotates magnetic disks at a constant speed. When a measurement instruction is received from a disturbance generating unit and the upper-level device, sine wave disturbance is generated in the revolution speed of the spindle motor which depends on the motor drive control unit. A speed detecting unit detects the revolution speed of the spindle motor as measured data while the disturbance is being generated by the disturbance generating unit. A measured data transferring unit transfers the detected measured data detected by the speed detecting unit to the upper-level device, wherein control characteristics such as gains and phases with respect to frequencies of the motor control unit are computed.