Patent ID: 7352109

Claim:
A flat type piezoelectric ultrasonic motor for generating a rotation force to a rotor by ultrasonic vibrations, the motor comprising: a vibrator formed of elastic material; a plurality of piezoelectric plates attached on the vibrator, each piezoelectric plate having an electrode surface to form an electrode; a rotor drivingly connected to the vibrator to be rotated thereby; and a power source unit for applying driving voltages to the piezoelectric plates, wherein the piezoelectric plates are arranged on quartered surface areas of the vibrator in such a way that longitudinal axes of neighboring piezoelectric plates form a given angle therebetween and opposing piezoelectric plates have opposite polarizations; the electrode surface of the piezoelectric plates being normal to a rotation axis of the rotor; and the power source unit configured to apply alternating driving voltages to the piezoelectric plates to thereby rotate the rotor.