| 摘要 |
PROBLEM TO BE SOLVED: To realize a stable driving without installing monitor electrodes or searching for a resonance frequency before driving by providing a means for controlling a frequency signal when an actual driving speed is different from a target one. SOLUTION: In order to control a vibrating motor 9, it is necessary that the frequency of a frequency signal is so adjusted that a desired speed can be obtained at a higher frequency than a resonance frequency and a driving frequency region is so restricted that the frequency may not become lower than the resonance frequency. Therefore, the possible maximum speed is stored for each integrated value of driving time. When a revolutional speed of a motor 9 is higher than the stored maximum speed, the frequency is increased by a predetermined value to lower the speed. By this method, the driving frequency never become lower than the resonance frequency even if the resonance frequency changes with the lapse of time. Furthermore, a driving termination processing is conducted for the motor 9 and an up/down counter 13, a frequency divider/phase shifter 4, and a timer are stopped by the processing. |
