MAGNETORESTRICTIVE ACTUATOR AND SPEAKER AND DEVICE USING SAID MAGNETORESTRICTIVE ACTUATOR

摘要

Disclosed is a magnetorestrictive actuator equipped with: a magnetorestrictive element that extends along a central axis; a movable unit that is displaced in response to the deformation of the magnetorestrictive element; a voice coil wound around the center of the magnetorestrictive element; a magnet that encloses the magnetorestrictive element and the voice coil; a lower yoke having an upper surface joined to the lower surface of the magnet and the lower surface of the magnetorestrictive element; a lower surface joined to the upper surface of the magnet; an upper yoke having an inside surface that faces the outside surface of the movable unit, with a space intervening therebetween, and an elastic material provided in said space and joined to the outside surface of the movable unit and the inside surface of the upper yoke. This magnetorestrictive actuator can be made thin, suppresses unnecessary oscillation, and has good linearity.