| 摘要 |
PURPOSE:To easily start an ultrasonic motor by preventing the drop of the inside temperature of the motor while the motor is stops. CONSTITUTION:A signal supply section 47 rotates an ultrasonic motor M by supplying a first drive signal SIN to the piezoelectric diaphragm 11 of the motor through an oscillation circuit 51 and drive circuit 55 and second drive signal COS to the diaphragm 11 through the circuit 51, a phase shift circuit 53, and another drive circuit 57. When the motor M stops, the section 47 stops the output of a signal phi2 from the circuit 53 through a rotation control circuit 49 and phase control circuit 59. When only the first drive signal SIN is supplied to the motor M, generation of progressive oscillatory waves from a conductive elastic body 9 is suppressed and, on the other hand, the diaphragm 11 and elastic body 9 vibrate and generate heat. |
