| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a driver and a driving method of an oscillatory actuator in which a drive frequency can be controlled not to reach a cliff omission region even after the oscillatory actuator is not used for a long term and left as it is. <P>SOLUTION: After an ultrasonic motor 30 is started, a CPU 231 measures a time required for starting the rotation of the motor by using an encoder 244 and a timer 233, determines whether the ultrasonic motor 30 is started after it is left in a non-use state for a long term or not based on a time required for starting rotation. When it is determined that the motor is started after it is left in the non-use state for a long term, a minimum drive frequency, a target speed and the like, are altered appropriately in order to prevent the drive frequency from reaching a cliff omission region. <P>COPYRIGHT: (C)2007,JPO&INPIT |
