| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to efficiently obtain large amplitude over a long time by impressing electric fields of an always the same direction as a polarization direction to respective piezoelectric substances of which the polarization directions face the same direction. SOLUTION: The piezoelectric vibrator 1 is formed by sticking the piezoelectric substance 11 consisting of piezoelectric ceramics onto a diaphragm 10 and sticking the piezoelectric substance 12 to the rear surface of the diaphragm 10. Quadrisected weights 14 are fixed to the circumference of the diaphragm 10 by holding the piezoelectric substance 11 with a holding member 13. The piezoelectric substances 11 and 12 are reverse biased by DC power sources 4 and 5 and the excitation voltages of the same phase are set by an AC power source 3 within the range of the bias voltage. The electric fields of always the forward direction are impressed to the respective piezoelectric substances 11 and 12. The same bias voltages varying in the absolute value are, therefore, impressed to the two piezoelectric substances 11 and 12 when the excitation respective voltages are respectively at a mid-point potential and, therefore, the two piezoelectric substances 11 and 12 spread by the same quantity and a vibrator does not deflect. |
