| 摘要 |
PROBLEM TO BE SOLVED: To assure a large sound pressure to be adopted for a portable telephone set or a pager, etc., by forming a sound-producing body in such a manner that a metallic plate is bent largely for assuring a large sound pressure by a piezoelectric effect and the excitation effect of a coil disposed at the metallic plate for the purpose of generating the sounds of the large sound pressure and to utilize this coil for the purpose of vibration generation as well. SOLUTION: A piezoelectric diaphragm 1, consisting of a piezoelectric element 2 and a metal plate 3, is provided with a coil 4 to be excited by inputting of pulse waves. The electrode of the piezoelectric element 2 and the terminal of the coil 4 are electrically connected. A stator 5 is fixed to a leaf spring 9. The coil 4 is inserted into the magnetic circuit of the stator 5. An excitation part B is formed by the stator 5 and the leaf spring 9. |
