Abstract: Electrodes (7, 8, 9), having curved sections in the shape of the outline thereof, are disposed in areas of a rectangular plate-shaped piezoelectric transducer element (1) in which the strain in the natural mode of vibration is large. The electrodes (7, 8) which excite a bending vibration are disposed in areas in which the strain in the bending natural mode is at least a predetermined value, and the outline curved sections of the electrodes (7, 8) are shaped so as to follow along strain contours (3, 4), and the electrode (9) which excites a stretching vibration is disposed in an area in which the strain in the stretching natural mode is at least a predetermined value, thus providing a transducer for an ultrasonic motor which aims to reduce transducer loss (increasing vibration efficiency), and improve transducer durability and reliability.

Abstract: A piezoelectric actuator mechanism including: a screw-driven feeding mechanism that has a feed screw (11) and a feed screw nut (14); a disc-shaped rotor (17) mounted on the rear-end face of the feed screw nut (14); an ultrasonic motor (18) having a piezoelectric vibrator (19) that comes in contact with the circumference face of the rotor (17); and a driven mounting portion that is pressed against the leading end of the feed screw 11 by spring force, and displaced and positioned by the feeding operation of the feed screw. The driven mounting portion can be made to be a mirror holder (1) for use in an optical system, or a movable table (21) of a linear stage.

Abstract: Electrodes (7, 8, 9), having curved sections in the shape of the outline thereof, are disposed in areas of a rectangular plate-shaped piezoelectric transducer element (1) in which the strain in the natural mode of vibration is large. The eletrodes (7, 8) which excite a bending vibration are disposed in areas in which the strain in the bending natural mode is at least a predetermined value, and the outline curved sections of the electrodes (7, 8) are shaped so as to follow along strain contours (3, 4), and the electrode (9) which excites a stretching vibration is disposed in an area in which the strain in the stretching natural mode is at least a predetermined value, thus providing a transducer for an ultrasonic motor which aims to reduce transducer loss (increasing vibration efficiency), and improve transducer durability and reliability.