| 摘要 |
PURPOSE:To eliminate the necessity of providing an elastic body with a detecting piezoelectric body separate from an exciting piezoelectric body and also to make a wiring for taking out the output signal of an applied voltage- detecting means and conducting current-detecting means unnecessary by making it possible to detect the vibrational state of a vibrator from the output signal. CONSTITUTION:An apparatus is provided with a quantity of state-detecting means composed of an applied voltage-detecting means 6a for detecting an applied voltage to a piezoelectric body 1, a conducting current-detecting means 6b for detecting a conducting current and an operational means 6c for outputting a deviation quantity between the resonance frequency of a vibrator 3' and the frequency of the applied voltage from the output signal of the applied voltage-detecting means 6a and conducting current-detecting means 6b. Then, the oscillation frequency of a power supply means 5 is controlled appropriately to operate an ultrasonic motor stably. Thus, it is made unnecessary to provide an elastic body 2 with a detecting piezoelectric body separate from an exciting piezoelectric body 1 and also a wiring for taking out the signal so that the manufacturing process of a motor is simplified. |
