ULTRASONIC TRANSDUCER AND ULTRASONIC SPEAKER EMPLOYING IT

摘要

PROBLEM TO BE SOLVED: To generate an acoustic signal having a sound pressure level high enough to attain parametric array effect over a wide frequency band. SOLUTION: The ultrasonic transducer comprises a fixed electrode 10 having irregularities on the surface; a diaphragm 12 with an electrode layer 12B arranged on the surface of the fixed electrode 10; and a member 30 for holding the fixed electrode 10 and the diaphragm 12. The ultrasonic transducer is driven by applying an AC signal between the electrode layer 12B of the diaphragm 12 and the fixed electrode 10. A sound pressure of 120 dB or above is generated in the frequency range of 20-120 kHz. COPYRIGHT: (C)2006,JPO&NCIPI