| 摘要 |
PROBLEM TO BE SOLVED: To achieve stable drive of a piezoelectric actuator, while using a drive circuit of a simple configuration. SOLUTION: Electrodes 33a, 33c are formed at two corners on a piezoelectric element 30 of a diaphragm 10, and an electrode 33b is formed on the entire surface other than the corners. A drive circuit 500 is connected in parallel with the electrodes 33a, 33c and the electrode 33b, and a capacitor 505 for adjusting a frequency is connected between the electrodes 33a, 33c and the drive circuit 500. A drive voltage, that is supplied from an oscillating circuit 504, is supplied at a frequency, as it is, to the electrode 33b, while the drive voltage of a frequency adjusted by the capacitor 505 is supplied to the electrodes 33a, 33c. Here, as the capacitor 505, a capacitor is used of such a capacity that adjusts the frequency, in such a way that the vertical oscillations of the diaphragm 10 including the capacitor 505 as seen from the drive circuit 500 almost matches with to the resonance frequency of the curvature oscillations. |
