| 摘要 |
PURPOSE:To drive an oscillator with low power supply voltage by reversing the phase of voltages to be applied, respectively, on the common electrode and one or a plurality of driving electrodes of the oscillator. CONSTITUTION:A piezoelectric element 3 comprises twelve oscillatory elements which can deform independently and provided, respectively, with driving electrodes 31-42. In this case, polarizing direction may be uniform and a common electrode is arranged entirely on the rear surface. When three adjacent oscillatory elements and diagonally disposed oscillatory elements are driven in-phase, oscillation mode of 2lambda is excited. Signals d, e, f are subjected to phase inversion with the timing of a, b, c and becomes in-phase or reverse phase of phir. At the time of reverse phase, voltage is applied alternately to the driving electrode side and the common electrode side and thereby the oscillatory element has an effect equivalent to application of double voltage of the driving voltage. Consequently, the oscillator can be driven with a low power supply voltage. |
