Patent ID: 7965457

Claim:
A vibratory driving device comprising: a shaft-like driving member; an electromechanical transducer that inclines the driving member and displaces the driving member in an axial direction of the driving member, a movable member which slidably engages on the driving member; a driving circuit that applies 1) a periodical frictional driving voltage to the electromechanical transducer so as to displace the driving member back and forth with a speed varying asymmetrically in the axial direction to displace slidingly the movable member with respect to the driving member and 2) an inclination driving voltage that inclines the driving member, a waveform determiner which determines a rising condition of a voltage or a current of the electromechanical transducer when the inclination driving voltage is applied, and a position estimator which estimates a position of the movable member based on the rising condition of the voltage or the current.