VIBRATION MOTOR CONTROLLER, AND LENS APPARATUS AND IMAGE PICKUP APPARATUS THAT INCLUDE THE SAME

摘要

A vibration motor controller controls driving velocity of a vibration motor relatively moving a vibrator and a contactor contacting the vibrator, the vibrator oscillated by an electromechanical energy transducer to which first and second frequency signals having a phase difference are applied, and includes a phase difference determiner storing a relationship between the frequency and phase difference between the first and second frequency signals, and determines the phase difference with respect to the frequency based on the relationship, and a controller controlling velocity of the vibration motor based on the frequency of the first and second frequency signals and the phase difference determined by the phase difference determiner based on the frequency. The relationship between the frequency and phase difference in the phase difference determiner does not include a relationship between frequency lower than a resonance frequency in frequency-velocity characteristics of the vibration motor, and the phase difference.

主权项

1. A vibration motor controller for controlling driving velocity of a vibration motor that relatively moves a vibrator and a contactor in contact with the vibrator, the vibrator oscillated by an electromechanical energy transducer to which a first frequency signal and a second frequency signal having a phase difference are applied,
the vibration motor controller comprising: a phase difference determiner that stores a relationship between a frequency and the phase difference between the first and second frequency signals, and determines the phase difference with respect to the frequency based on the relationship; and a controller that controls velocity of the vibration motor based on the frequency of the first and second frequency signals and the phase difference determined by the phase difference determiner based on the frequency, wherein the relationship between the frequency and the phase difference stored in the phase difference determiner does not include a relationship between a frequency lower than a resonance frequency in frequency-velocity characteristics of the vibration motor, and the phase difference.