Piezoelectric or magnetostrictive actuator device

摘要

An actuator device comprises an actuator element which has a shortest length when no electric voltage is applied and which is increased in length as an electric voltage applied thereto becomes higher, a displacement extracting part 17, and a converter mechanism for carrying out conversion of converting the change in length of the actuator element 11 into the displacement of the displacement extracting part 17. The converter mechanism comprises holders 14 and 13 and a transmission member 16 and carries out the conversion so that the displacement of the displacement extracting part 17 is decreased as the length of the actuator element 11 is increased. The converter mechanism carries out the conversion so that the displacement of the displacement extracting part 17 becomes maximum when the actuator element 11 has the shortest length.