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:
Sep. 07, 1999
Filed:
Jan. 07, 1998
Michael J O'Brien, Rochester, NY (US);
Robert C Bryant, Honeoye Falls, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
A piezoelectric motor system is formed with a piezoelectric motor incorporating an element that is physically displaced as a function of an applied voltage resulting in the generation of a back electromotive force. The system incorporates a controller having an output connected to the piezoelectric motor. The controller receives a direction signal indicating the desired drive direction of the piezoelectric motor and a velocity signal indicating the desired velocity of the piezoelectric motor. The controller provides a drive voltage for driving the piezoelectric motor in the desired drive direction. An electrical equivalent circuit that mirrors the electrical characteristics of the piezoelectric motor is connected to receive the drive voltage from the controller. A comparator provides a difference signal indicative of the difference in voltage developed across the piezoelectric motor and the voltage developed across the electrical equivalent circuit. An integrating circuit receives the difference signal and provides a feedback signal to the controller. The difference signal is compared with the velocity signal to either increase or decrease the drive voltage applied to the piezoelectric motor so as to cause the piezoelectric motor to achieve the desired velocity.