Abstract

An ultrasonic motor comprises a piezo-electric element and electrode patterns disposed on a surface of the piezo-electric element at nearly equal intervals in a multiple of four. A vibrating member is disposed on another surface of and electrically connected to the piezo-electric element. A moving member is movably disposed on the vibrating member. First projections which frictionally drive the moving member by expansion and contraction movement of the piezo-electric element are disposed on a surface of the vibrating member near every other one of the boundaries of the electrode patterns of the piezo-electric element. Second projections are provided at each intermediate position between the first projections near all of the boundaries of the electrode patterns other than the boundaries near which the first projections are provided for adjusting the vibrating conditions of the vibrating member. The second projections have a different height from the first projection and do not frictionally drive the moving member. A pressure-regulating member urges the moving member into pressure contact with the vibrating member at a predetermined pressure.