Image pickup apparatus, interchangeable lens unit, camera body, and ultrasonic motor driving apparatus

摘要

An image pickup apparatus of the present invention is an image pickup apparatus including an ultrasonic motor 35 that moves a focus lens 24, and further including a correction control part 100 that operates the ultrasonic motor 35 under a predetermined condition. The correction control part 100 is capable of executing a correction process by measuring a frequency characteristic of an applied voltage at the time of operating the ultrasonic motor 35 at a predetermined rotation speed, comparing the frequency characteristic with a preset reference frequency characteristic, and correcting the frequency characteristics on the basis of a difference between the frequency characteristic and the reference frequency characteristic so as to calculate a correction frequency characteristic. Accordingly, even when the frequency characteristic of the ultrasonic motor varies due to wear of the ultrasonic motor and mechanical components coupled thereto, a stable drive can be maintained over a long time.