Patent ID: 6593712
Filing Date: 2003-07-15
Classification: H02N

Abstract:
A control device for a vibration wave motor which obtains a driving force by applying a periodic voltage to an electro-mechanical energy conversion element so as to generate in a vibration member thereof a plurality of standing waves having a phase difference therebetween, the plurality of standing waves being synthesized to generate a driving vibration in the vibration member, the control device comprising:a frequency control circuit which varies a frequency of the periodic voltage and, when a driving force of the vibration wave motor is to be stopped, varies the periodic voltage so as to achieve a predetermined frequency at which a rotational speed of the vibration wave motor becomes zero; and a voltage control circuit which gradually lowers a voltage level of the periodic voltage to a predetermined voltage and then, after the frequency control circuit varies the frequency so as to achieve the predetermined frequency, stops energization of the vibration wave motor.