| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric actuator that has a function for detecting the amount of own displacement and the direction without adding any external sensors. SOLUTION: In this piezoelectric actuator having electrodes on a wall surface inside and outside a tube piezoelectric body 101, at least one of the electrodes existing inside and outside the tube is composed of electrodes 102, 103, 104, and 105 for displacement generation, and electrodes 106, 107, 108, and 109 for displacement detection, thus detecting the amount of own displacement and the direction of the displacement by utilizing the own piezoelectric effect of the actuator itself without requiring any external sensors. |
