US Patent 7183697 Actuator

An actuator, comprising a beam (2) including a laminated structure which has piezoelectric layers (30, 31, 32) and electrode layers (20, 21, 22, 23), a holding mechanism to hold the beam, a feeding terminal (10) to supply an exciting power to the electrode layers of the beam, and a contact mechanism provided in the holding mechanism, the holding mechanism comprising a case (1) including a space (5) to house the beam (2) and a holding part to hold at least one of an end and a central portion of the beam (2), the contact mechanism being configured to contact with a part of the beam (2) and prevent the beam from excessively deflecting when a great impact is added to the beam.