Patent ID: 7679848
Filing Date: 2010-03-16
Classification: G02B,H02N

Abstract:
1. An actuator comprising: an electro-mechanical conversion element; a driving frictional member attached at one end of the electro-mechanical conversion element with respect to a direction of expansion and contraction thereof; a plurality of driven members frictionally engaged with the same driving frictional member; a plurality of biasing units, each biasing one of the plurality of driven members with a biasing force which is perpendicular to said same driving frictional member, to frictionally engage said driven members with said same driving frictional member; a biasing-force adjusting unit that adjusts said respective biasing-forces of the plurality of biasing units; and a controller that controls the biasing-force adjusting unit to vary a value of said biasing force applied to one of said driven members.