Ultrasonic motor and method of driving the same

摘要

An ultrasonic motor comprises a piezoelectric element functioning as a driving source; a rectangular-parallelepipedic elastic body coupled to the piezoelectric element and vibrated by the piezoelectric element; and a driving circuit for generating a driving signal consisting of a burst wave with an envelope having attenuation characteristics in a vibration attenuation period of the elastic body and applying the driving signal to the piezoelectric element, thereby generating an extending/contracting vibration along a longitudinal direction of the elastic body and a bending vibration propagating in the longitudinal direction of the elastic body.