| 摘要 |
PURPOSE:To make the quantity of step of a mover smaller than the interval between the nodes of standing waves and the quantity of shifting of nodes of standing waves, in an ultrasonic motor for driving a mover by steps. CONSTITUTION:An ultrasonic wave oscillating circuit 107 generates progressive waves for rotating a mover 112 or standing waves for stopping it. A changeover circuit 108 controls the operation of inputting the output signal of the ultrasonic wave oscillation generating circuit 107 and outputting output pulses to a piezoelectric oscillator driving circuit 109. Ultrasonic oscillation is generated in an oscillator 111 which has a plurality of comb-toothed projections. The mover 112 has unequal parts, and the number of unequal parts is larger than the number of nodes at standing wave oscillation. The mover 112 performs operation such as rotation, stoppage, etc. The mover stops in the position where the force is balanced, by the position of the unequal part of itself, the position of the node of the standing wave, and the position of the projection of the oscillator, by changing progressive waves and standing waves over to each other in proper condition. That is, the step angle of the mover can be made smaller than the interval between the nodes of the standing waves or the quantity of shifting of the nodes of the standing waves. |
