Patent ID: 7701119
Filing Date: 2010-04-20
Classification: H04R

Abstract:
1. A piezo-electric actuator comprising: a piezo-electric element having a piezo-electric body which is provided with at least two opposing surfaces, wherein the surfaces perform an expanding and contracting motion in accordance with a state of an electric field; a constraint member for constraining the piezo-electric element on at least one of the two surfaces, a supporting member disposed around the constraint member, but not below the constraint member, and a plurality of beam members each having both ends that are fixed to the constraint member and the supporting member, respectively, wherein each beam member has a neutral axis for bending in a direction substantially parallel with the constrained surface, wherein the constraint member vibrates by vibration which is generated by constraining effect between the constraint member and the piezo-electric element, and is amplified by the beam members, wherein said beam members are straight beams, wherein said beam members are made of resin, wherein the constraint member and the plurality of beam members comprise an integrated unit, and wherein a vibrating film made of polyethylene terephthalate (PET) is attached to the integrated unit.