DRIVING METHOD OF ULTRASONIC MOTOR

摘要

PURPOSE: To improve the positioning precision of a moved unit by a method wherein a reverse thrust is not generated in the attenuating section of an elliptical vibration. CONSTITUTION: An expansion/contraction vibration in the longitudinal direction of an elastic unit 1 which has a rectangular-parallelepiped shape and a bending vibration which is propagated in the longitudinal direction of the elastic unit 1 are generated by piezoelectric transducers 2a and 2b which are driving sources. In an ultrasonic motor like this, a driving circuit which generates a driving signal whose envelope has attenuating characteristics in the vibration attenuating section of the elastic unit 1 and applies the signal to the piezoelectric transducers 2a and 2b is provided.