Patent ID: 8391701

Claim:
An actuator comprising: a base comprising a plate and a ring-shaped protrusion extending from the plate, the plate defining an aperture, the protrusion surrounding the aperture; a stationary frame mounted on the base; a driving member comprising a piezoelectric motor and a ring-shaped transmission unit, the piezoelectric motor fixed on the base, the transmission unit having a first end surface and an opposing second end surface, the transmission unit rotatably sleeving on the protrusion, the first end surface abutting against the piezoelectric motor, the second end surface defining a wedge-shaped groove, the wedge-shaped groove occupying a portion of the second end surface along the circumferential direction of the transmission unit; a moveable frame comprising a body and a wedge-shaped stripe extending from the body and facing toward the wedge-shaped groove, the moveable frame supported by the second end surface, the wedge-shaped stripe partially or entirely engaging in the wedge-shaped groove; and two guide poles extending through the moveable frame, one end of each of the two guide poles fixed on the base, the other end of each of the two guide poles fixed on the stationary frame.