| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric actuator being capable of producing large output while preventing breakage of a piezoelectric element, and a driving device thereof.SOLUTION: A piezoelectric actuator comprises: a piezoelectric element causing a portion brought into contact with a rotating body to be moved and the rotating body to rotate; and a driving circuit sending electric power to the piezoelectric element. The driving circuit comprises: a driving voltage generation circuit 51 generating a driving voltage including an AC component having a first frequency; a filter circuit 52 cutting off a driving voltage having a second frequency higher than the first frequency by means of action of an inductor 52 L and a capacitor 52C; and a protection circuit 53 being provided at an output side of the filter circuit so as to be connected in parallel to the piezoelectric element and energized with a current when the driving voltage exceeds a lower limit value or an upper limit value of an acceptable range of a voltage applied to the piezoelectric element.SELECTED DRAWING: Figure 7 |
