| 摘要 |
PURPOSE:To prevent noises generated at the time of reversal, and to shorten the time required for reversal by a method wherein the current value of driving frequency is stored when the direction of movement of a moving body is reversed, the driving frequency is made sufficiently higher than the current value, the phase is inverted and swept to a storage value, and the speed of travel of the moving body is controlled. CONSTITUTION:When the direction of movement of a moving body 26 is reversed, the current driving frequency is stored in an information storage means 6 while driving frequency is made sufficiently higher than a current value, the phase is inverted and swept to a storage value, and the speed of travel of the moving body 26 is controlled by a speed control means 7. A frequency signal, whose phase differs by 90 deg. is output to a power amplifying means 10 by a 90 deg.-phase means 8. Power is amplified to have a voltage level required for driving an ultrasonic motor 1 from the power amplifying means 10 and 9, and a constant voltage level is applied to each electrode of a piezoelectric body and supplied with power. Accordingly, noise generated at the time of reversal can be prevented, and the time necessary for reversal can be shortened. |
