| 摘要 |
PURPOSE:To reduce generation of unnecessary vibration by forming no electrode of 3/4lambda of the electrode patterns of a piezoelectric material. CONSTITUTION:An ultrasonic motor is provided in its piezoelectric material with A to B phase electrodes 3 to 4 arranged by shifting a relative position each by 1/2lambda and applying voltage of 90 deg. different phase, sensor electrodes 1, 5 by an electrode pattern part of 1/4lambda and non-electrode parts 2, 6. A motor driving circuit consists of a VCO circuit holding in a fixed value voltage, generated in the sensor electrodes 1, 5, and a phase difference of voltage between A and B phases. As the result, a decrease of driving efficiency by a temperature change or the like can be prevented. |
