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. 05, 2002
Filed:
Jun. 23, 1999
Seiko Epson Corporation, Tokyo, JP;
Abstract
The present invention provides a rotation controller adjusting the speed of a rotary member ( ). Phase difference compensating means ( ) outputs a phase difference compensating signal ( ) corresponding to a phase difference between a rotation signal of the rotary member ( ) and a target signal, and frequency difference compensating means ( ) outputs a frequency difference compensating signal ( ) corresponding to a frequency difference between these signals. The rotary member ( ) is braking-controlled by means of these signals. Use of the phase difference compensating signal ( ) permits achievement of PLL control, and maintenance within the locking range allows a stable rotation control with a high response. Further, use of the frequency difference compensating signal ( ) makes it possible to quickly bring the control within the locking range even when the rotary member ( ) deviates from the target signal, and thus to carry out a control with a high response even upon riseup of the rotary member ( ).