초록 ▼

Disclosed is a driving apparatus for a vibration wave motor in which monitor means is provided for detecting the vibrating state of the vibration wave motor and the difference between the resonance frequency and the frequency of a driving AC signal is detected on the basis of the phase difference be

Disclosed is a driving apparatus for a vibration wave motor in which monitor means is provided for detecting the vibrating state of the vibration wave motor and the difference between the resonance frequency and the frequency of a driving AC signal is detected on the basis of the phase difference between the output signal from the monitor means and the driving AC signal and when the frequency difference is great during the change of the number of revolutions of the motor, the vibration rate of the frequency of the driving AC signal is made greater to improve the responsiveness while, on the other hand, when the frequency difference is small, the variation rate of the frequency of the driving AC signal is made smaller to thereby prevent the occurrence of an unstable operation in which the frequency of the driving AC signal exceeds the resonance frequency to cause sudden stoppage of the motor.

대표청구항 ▼

A vibration wave driven motor comprising: (a) a first member having a friction surface; (b) a vibration member arranged in contact with the friction surface of said first member; (c) an electro-mechanical transducer arranged in contact with said vibration member to generate the travelling vibration

A vibration wave driven motor comprising: (a) a first member having a friction surface; (b) a vibration member arranged in contact with the friction surface of said first member; (c) an electro-mechanical transducer arranged in contact with said vibration member to generate the travelling vibration wave to said vibration member in response to an applied driving signal with a predetermined frequency; (d) monitoring means for monitoring the vibrating state of said motor and outputting a signal conforming to the amount of deviation from the resonancevibrating state; and (e) frequency changing means responsive to the output signal from said monitoring means to change the frequency of the driving signal greatly when said amount of deviation is greater than a predetermined value, and to change the frequency of the driving signal small when said amount of deviation is smaller than said predetermined value.