PIEZOELECTRIC ACTUATOR

PROBLEM TO BE SOLVED: To provide a piezoelectric actuator that maintains the polarization property of a piezoelectric material element well, and is suitable for a long duration drive. SOLUTION: In the piezoelectric actuator constituted by adhering a pair of piezoelectric material elements 12 to the front and rear of a shim 11 made of a metal thin plate, an alternating voltage is applied to only one side of the pair of the piezoelectric material elements 12 by an alternating current power supply 16, a feed switching means 20 is provided, which switches the piezoelectric material element 12 to which the alternating voltage is applied, for every constant time longer than the cycle of the alternative voltage. If the piezoelectric material element 12 which is made to drive is switched before the vibration displacement of the piezoelectric material element 12 decreases, or before the temperature rise of the piezoelectric material element 12 increases, the deterioration of the polarization property caused by the temperature rise and the deterioration of vibration property of the piezoelectric material element 12 can be prevented, and the piezoelectric material element 12 which is not made to drive acts so as to increase vibration acceleration. COPYRIGHT: (C)2010,JPO&INPIT