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. 02, 1993
Filed:
Apr. 29, 1992
Applicant:
Inventors:
Assignee:
Alps Electric Co., Ltd., Tokyo, JP;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
318135 ; 310316 ; 310323 ; 318460 ;
Abstract
A control device for an ultrasonic motor for controlling to drive the ultrasonic motor according to a logical AND operation between a control pulse having a duty ratio changing from 100% to 0% according to a moving position of the ultrasonic motor and a driving signal having a resonance frequency of the ultrasonic motor. Accordingly, after starting the ultrasonic motor at a maximum speed, a moving speed of the ultrasonic motor can be gradually reduced until it reaches a target position, and when reaching the target position, the ultrasonic motor can be stopped precisely at the target position.