PURPOSE: To miniaturize a standing wave type of piezoelectric driving motor, and facilitate the control of the direction of normal and reverse driving.
CONSTITUTION: An elastic oscillator 1 is fixed between the mobile ends of a pair of piezoelectric elements 2a and 2b one end each of which is fixed and are counterposed in opposition, and second mode of standing wave oscillation is generated in the elastic oscillator 1 by the deformation of the elastic oscillator 1 at the time of having applied voltage while shifting the phase of each piezoelectric element 2a and 2b 90°, and at the same time, the elastic oscillator 1 causes the shifting of the center of gravity, and the specified point on the elastic oscillator performs elliptic motion, so it becomes possible to drive the mover 5. The driving direction of the mover 5 can be controlled in both normal and reverse directions by shifting the voltage phase applied to each piezoelectric element 2a and 2b π/2 or -π/2.