| 摘要 |
PURPOSE:To drive an optical system with high accuracy by forming a support member into a curved arm shape and providing a piezoelectric element into a space enclosed by said support member. CONSTITUTION:When the voltage is impressed to a piezoelectric element 101, the element 101 has a mechanical strain and is displaced in the direction A-A'. This displacement is transmitted to the direction (a) of a frame body part 102a via a head 103 attached at the tip part of the element 101. Then the displacement degree is mechanically amplified by the part 102a. In other words, a point of force produced by the head 103 is set closer to the fulcrum side than the position of a hinge part 102d serving as an action point with the position of a hinge part 102e defined as a fulcrum. Thus the displacement degree of the element 101 is amplified by the action of levers and transmitted to a support member 102. The end face of the part 102a is fixed to a base 111 and therefore an optical system holder attachment part 102b is displaced in the direction (b), e.g., the tracking direction with a shaft hole 102c defined as the center of a curvature radius. The distance between the action point and the the hole 102c is smaller than that between the part 102a and the hole 102c. Therefore the displacement of the element 101 is amplified further at the part 102b.
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