| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive method for an ultrasonic motor which can perform the smooth rotation. SOLUTION: This ultrasonic motor is equipped with the first frequency divider 16D1 which divides the signal of frequency(f) into (n), a phase comparator 16D2 which has this divided signal and a feedback signal inputted, an integrator 16D3 which integrates the output of the phase comparator 16D2, a voltage control oscillator 16D4 which has the output of the integrator 16D3 inputted, and the second frequency divider 16D5 which divides the frequency of the output of the voltage control oscillator 16D4 into N and feeds it back as the above feedback signal to the phase comparator 16D2. Here, the signal of the frequency(f) is inputted into the first frequency divider 16D1, and a drive signal fOUT is generated from the signal of the frequency f.N/n outputted from the voltage control oscillator 16D4. The maximum value of N is under A, and 10×f/n is set to be larger than one-Ath as large as natural frequency F. |
