| 摘要 |
PURPOSE:To stabilize the driving speed of an ultrasonic motor unaffected by ambient environment, etc., by constituting a driver of an ultrasonic motor by a reference pulse generation means to generate the reference pulse of frequency, a phase difference signal generation means and an integration means to integrate and output the phase difference signal. CONSTITUTION:The main part is composed of a reference pulse oscillator 1, a phase comparator 2, an integrator 3, a voltage control oscillator(VOC)4, a dividing phase circuit 5, power amplifiers 6a and 6b, and an ultrasonic motor 8. When the reference pulse oscillator 1 generates a reference pulse, a moving piece is rotated and a pulse is generated at an encoder 9 in proportion to the moving speed. The signal in response to the phase difference between the reference pulse and an encoder output pulse is integrated by the integrator 3 and the pulse of frequency in response to the integrated signal is amplified by power amplifiers 6a and 6b through the VOC4 and the dividing phase-shift circuit 5 and applied to the ultrasonic motor 8. Even if the condition such as ambient environment and applied force is changed, the driver can thereby be rotated at a specified rotating speed. |
