| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ultrasonic motor, capable of driving a moving a member in the forward and the reverse direction on an AC voltage of single phase, at a high driving efficiency. <P>SOLUTION: In a piezoelectric ceramic square plate 101 of an ultrasonic motor 10, the mode shape due to resonance is asymmetric at a first corner 23 and a second corner 24. By having an AC voltage applied between any one of split electrodes 41a-41d formed on one main surface 30 of the piezoelectric ceramic square plate 101 and a common grounding electrode 102 of the other main surface 35, the corner where a maximum displacement occurs due to resonance is switched between the first corner 23 and the second corner 24. Then a frictional element 103 for driving the moving member 107 in the forward direction and a frictional element 104 for driving the moving member 107 in reverse direction are provided respectively to the first corner 23 and the second corner 24. <P>COPYRIGHT: (C)2010,JPO&INPIT |
