| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric acoustic transducer, capable of keeping a flat sound pressure level in decibel over a wide frequency band. SOLUTION: A piezoelectric acoustic transducer 10 is provided with a piezoelectric diaphragm, formed by sticking a piezoelectric element 11 onto a substrate 12 and a case for holding the circumferential part of the piezoelectric diaphragm. The substrate 12 has a sheet-like a shape, formed by sticking a metal foil 18 onto an insulator 17, a prescribed pattern is formed on the foil 18, and modulus of elasticity is nonuniform on the substrate 12. In this way, various oscillation modes can be produced on the substrate 12, to keep the flat sound pressure level over a wide frequency band. |
