The ultrasonic motor null which utilizes the vibration with the traveling wave

摘要

PURPOSE:To obtain an ultrasonic motor having a small size and high wiring operability by wiring a first electrode phase electrically connected with a plurality of first electrodes, a second electrode phase electrically connected with a plurality of second electrodes, and a monitor electrode. CONSTITUTION:A ringlike piezoelectric element 1 is coated on entire one side surface with a ringlike common electrode 2 and on the other surface with a segment electrode group 3. The group 3 has sixteen segment electrodes 3a-3p. The electrode 3a of them has a length of 3/4lambda in a circumferential direction, and the electrode 3b is deviated in a length of 1/4lambda at 180 deg.C from the electrode 3a in a circumferential direction. The electrodes 3c-3i are disposed at one side between the electrodes 3a and 3b in a length of lambda/2 in a circumferential direction. On the other hand, the electrodes 3j-3p are disposed at the other side between the electrodes 3a and 3b in a length of lambda/2 in a circumferential direction. Regions of the element 1 in which the electrodes 3a-3i are opposed to the electrodes 3j-3p are so polarized as to be different in polarized directions from adjacent regions.