| 摘要 |
PURPOSE:To reduce an industrial cost and miniaturize a device, by detecting the cycle of waveform distortion through monitor voltage generated by excitation, on a section without the applied input voltage of a piezoelectric unit. CONSTITUTION:An ultrasonic wave motor 1 is provided with a stator 10 and a rotor 20, and the stator 10 is composed of an elastic unit 11 and a piezoelectric unit 12. The surface of the piezoelectric unit 12 is provided with electrodes 12a-12d divided into four sections. The electrode 12d is a section without applied input voltage, and on the electrode 12d, the voltage (hereinafter, monitor voltage) of the mechanical excitation of the piezoelectric unit 12 converted to voltage is generated and is detected through a terminal P. The rotor 20 is composed of a rotor base metal 21 and a slider 22. In this case, the driving surface 22a of the slider 22 is provided with a groove section 22b for a discontinuous section, and from the rotation of the rotor 20, waveform distortion is generated on surface wave by the groove section 22b. Then, through the monitor voltage, the moving speed (rotational speed) of the groove section 22b can be detected. |
