Patent ID: 7620313

Claim:
A driving mechanism comprising: an actuator comprising: an electro-mechanical conversion element; a driving member which is connected to one end of the electro-mechanical conversion element and moves according to elongation or contraction of the electro-mechanical conversion element; and a weight member provided on the other end of the electro-mechanical conversion element; a driven member frictionally engaged with the driving member; and a driving circuit that drives the actuator, wherein the actuator allows the driven member to move along the driving member, and the driving circuit drives the electro-mechanical conversion element at a driving frequency f which gives f≧2 1/2 ·f 0 when resonance frequency of a 1-freedom system is f 0 in which the electro-mechanical conversion element and the driving member are designated as a mass and the weight member is designated as a spring, and driving frequency of the electro-mechanical conversion element is f, wherein a material of the weight member has a greater specific gravity than the driving member and is smaller in Young's modulus than the driving member and also a material of the electro-mechanical conversion element.