| 摘要 |
PROBLEM TO BE SOLVED: To provide a vibration actuator having a piezoelectric element for detection which is arranged to detect a velocity element of an elastic body with high sensitivity. SOLUTION: When rectangular and thin piezoelectric element plates 12a to 12d bonded to the surface of an elastic body 11 is driven by application of a driven voltage, the longitudinal vibration in parallel of the contact surface with a relative motion member 21 and flexure vibration in the direction crossing the vibrating direction of longitudinal vibration are generated on the elastic body 11 and the driving force extracting members 13a and 13b make the elliptical motion due to the harmonizing mode of these vibrations and thereby the relative motion member 21 moves in straight. The piezoelectric elements 12e, 12f for detection to detect motion of elastic body 11 as an elastic signal are provided symmetrically in the right and left directions to the node in the area near the nodes B4b and B4d in both sides of the center node among a plurality of nodes of the flexure vibration and moreover locally at the area near the longer side of the elastic body 11. |
