| 摘要 |
PROBLEM TO BE SOLVED: To make a stable and precise constant-speed control available even if the environment such as the temperature changes by providing a driving signal inputting section with an integration circuit which integrates an input signal and then outputs a voltage waveform and a switching circuit which switches the input signals for the integration circuit. SOLUTION: An integration circuit 15 integrates an input signal with a desired reference voltage Vc as a control initial value. The integration circuit 15 is so structured that the output Vo may monotonicly increase when the input is switched to Va by means of a switching circuit 16 and may monotonicly decrease when the input is switched to Vb, where Va=Vc-α, Vb=Vc+α (α>0). The upper and the lower limit of the driving frequency of a vibrating actuator 1 can be set by this method and thereby an unstable control can be prevented even near the resonance frequency without decreasing the efficency. Furthermore, a stable constant-speed control can be done even if the environment such as the temperature changes and thereby and a very precise constant-speed control is available. |
