Vibration wave driven motor

摘要

In a vibration wave driven motor wherein an AC electric field is applied to an electro-mechanical energy conversion element secured to an elastic member to thereby excite a plurality of standing waves differing in phase from each other in the elastic member and a travelling wave is formed in the elastic member by the combination of the standing waves, whereby a member which is in pressure contact with the elastic member and the elastic member are moved relative to each other by a frictional force, provision is made of means for making the contact pressure on the surface of contact between the elastic member and the member which is in pressure contact with the elastic member non-uniform, and means for making the dynamic rigidity of a vibration member non-uniform in an unnecessary vibration mode created by the means for making the contact pressure non-uniform, whereby the occurrence of noise is prevented by simple and inexpensive means.