Patent ID: 7253552

Claim:
A piezoelectric actuator comprising: a support body; an oscillating plate in which a plate-shaped piezoelectric device having a lengthwise direction and a reinforcing section are layered on top of each other; and a support member for applying an elastic force to said oscillating plate so that an end of said oscillating plate contacts a target to be driven, the support member being an elastic member that has a secured section that is secured to said support body and an attachment section that is attached to said oscillating plate; wherein application of electric power to said piezoelectric device excites a longitudinal oscillation in said piezoelectric device in the lengthwise direction of said oscillating plate; wherein a stretching and contracting component of said longitudinal oscillation at least partially drives a bending oscillation of said piezoelectric device in a widthwise direction of said oscillating plate; wherein a displacement of the oscillating plate caused by said longitudinal oscillation and said bending oscillation drives said target to be driven; wherein said oscillating plate is configured such that resonant frequencies of said longitudinal oscillation and said bending oscillation are substantially the same; and wherein said end that contacts said target to be driven of said oscillating plate has a protrusion, the protrusion contacting said target to be driven.