PIEZOELCETRIC DEVICE AND PIEZOELECTRIC SPEAKER USIONG THE SAME

摘要

PURPOSE: A piezoelectric device and a piezoelectric speaker using the same are provided to bond piezoelectric devices of different resonant frequencies with both sides of a vibration plate, thereby obtaining uniform sound features. CONSTITUTION: A piezoelectric device(100) vibrates if a signal voltage is applied to an electrode. The piezoelectric device includes three-layered piezoelectric ceramic plates(110,120,130). The piezoelectric ceramic plates are stacked wherein the polarization directions of the piezoelectric ceramic plates opposite each other. First to third piezoelectric ceramic plates are successively stacked.