Patent ID: 7368853

Claim:
A piezoelectric motor for moving a movable element in at least two directions, comprising: a resonator having a plane of symmetry; at least one piezoelectric component connected to the resonator for exciting the resonator to vibrate when an electric signal is applied to the piezoelectric component; wherein the piezoelectric element is located asymmetrically with respect to the resonator in such a way that the plane of symmetry of the resonator is not a plane of symmetry of the combination of resonator and piezoelectric component to cause the combination of resonator and piezoelectric component to have two distinct frequencies of operation F 1 and F 2 for moving the movable element; and resonance/anti-resonance pairs (f 1 , f 1 ′) and (f 2 , f 2 ′) such that the phase between the electric current and the electric voltage of a sinusoidal electric signal that is applied to the piezoelectric component declines for frequencies of the sinusoidal electric signal that lie inside each of the resonance/anti-resonance pairs.