| 摘要 |
PURPOSE:To increase the amplitude of ultrasonic wave oscillation, by dividing each electrode jointed to a piezoelectric ceramic unit, into four or more, and by contriving the voltage of mutually different polarities to be applied to the divided electrodes. CONSTITUTION:An ultrasonic wave driving device is composed of the piezoelectric ceramic unit 13 of a driving member 11 contacted to a driven member (ring-formed rotor) 12. On the surface of the piezoelectric ceramic unit 13, in the direction crossed over the direction of polarization, at a specified interval particularly in the orthogonal direction, a first-a second electrodes 15-16 are jointed, and are formed with four divided electrodes 15a-15d, 16a-16d separated at specified intervals along the direction of the polarization (radial direction). In this case, when specified control voltage is applied to spaces between respective divided electrodes 15a-15d, 16a-16d, then the piezoelectric ceramic unit 13 is moved in the circumferential direction with elongation-shrink mode as a whole, and ultrasonic wave oscillation is multiplied. As this result, the rotor 12 can be driven in the specified direction. |
