Patent ID: 8084921

Claim:
An ultrasonic motor drive apparatus comprising: a piezoelectric element of a cuboidal shape having a plurality of piezoelectrically active regions arranged along a first direction and a plurality of piezoelectrically active regions arranged along a second direction, in which longitudinal vibration and flexural vibration are induced with application of alternate signals to the plurality of piezoelectrically active regions; a piezoelectric element holder that is fixedly attached to the piezoelectric element at a position on and in the vicinity of a common node of the longitudinal vibration and the flexural vibration induced in the piezoelectric element; a vibrator holder having a plurality of openings provided toward the first directional axis and the second directional axis along a plane perpendicular to a third directional axis; a driven member having a substantially spherical shape that is rotationally driven by elliptical vibration generated by synthesis of the longitudinal vibration and flexural vibration induced on an end face of the piezoelectric element with respect to the third direction; an output shaft that is attached to the driven member and movable along the third direction in a certain range to transmit power output of the driven member; a pressing member that brings the driven member and the piezoelectric member into pressure contact with each other with a pressing force acting therebetween along the third direction; a cap having an opening and disposed at a position opposed to the piezoelectric member and the pressing member with the driven member between along the third direction, the cap receiving a pressing force while guiding the driven member; a link member one end of which is connected with the pressing member along the third direction and the other end of which can be connected with another apparatus; and a control section that applies an alternate signal to the piezoelectric member.