Piezoelectric actuator, ultrasonic motor equipped with piezoelectric actuator, and electronic apparatus equipped with piezoelectric actuator

摘要

A piezoelectric actuator comprises a plurality of piezoelectric elements stacked in a thickness direction thereof for undergoing expansion/contraction movement to vibrationally drive the piezoelectric actuator in accordance with a driving signal applied to the piezoelectric elements. Each of the piezoelectric elements has a length extending in a direction generally perpendicular to the stacking direction. The length of each of at least two of the piezoelectric elements being different from the length of at least one other of the piezoelectric elements.