| 摘要 |
PURPOSE: To start a motor smoothly by prohibiting the frequency holding operation of drive voltage and the shifting operation to high frequency side for a predetermined time after application of a drive voltage to a vibration wave motor and allowing the operations when the motor is started within a predetermined time. CONSTITUTION: A CPU 24 neglects the output from magnitude comparators 22, 25 for a predetermined time after sterting application of a drive voltage to a vibration wave motor and prohibits the drive frequency holding operation and the shifting operation to high frequency side. Immediately upon elapse of the predetermined time or upon starting rotation of the motor even within the predetermined time, the drive frequency holding operation and the shift operation to high frequency side are started based on the signals from the magnitude comparators 22, 25. Consequently, the vibration motor can be started smoothly and driven stably without being driven at a frequency lower than the resonance frequency. |
