MAGNETOSTRICTIVE ACTUATOR AND SPEAKER AND DEVICE USING SAID MAGNETOSTRICTIVE ACTUATOR

摘要

A magnetostrictive actuator includes a magnetostrictive element extending along a central axis, a movable section displaced in response to a change of a shape of the magnetostrictive element, a voice coil wound about the magnetostrictive element, a magnet surrounding the magnetostrictive element and the voice coil, a lower yoke having an upper surface coupled to a lower surface of the magnet and a lower surface of the magnetostrictive element, an upper yoke having a lower surface of the upper yoke being coupled to an upper surface of the magnet and an inside surface of the upper yoke facing the outside surface of the movable section across a clearance, and an elastic member disposed in the clearance. The elastic member joined to an outside surface of the movable section and the inside surface of the upper yoke. This magnetostrictive actuator has a low-profile structure, suppresses undesired vibration, and exhibits preferable linearity.