DRIVING CIRCUIT OF ULTRASONIC MOTOR

PURPOSE:To provide a driving circuit of an ultrasonic motor, which can perform highly accurate speed control by suppressing the dead zone in the vicinity of the phase inversion of an ultrasonic motor, and securing a wide dynamic range or securing high resolution. CONSTITUTION:This is the drive circuit of an ultrasonic motor 9, which drives cyclic signals to an ultrasonic oscillator 8, being equipped with an oscillator 4, which outputs signals in the vicinity of resonance frequency of the ultrasonic motor 9, a cycle setter 5, which sets how many cycles of waves to apply, from the frequency signals outputted by this oscillator 4, to the ultrasonic motor 9 per unit time, and a power amplifier 7 which amplifies the output of the oscillator 4 and applies it to the ultrasonic oscillator 8.