| 摘要 |
PURPOSE:To obtain an ultrasonic wave ceramic microphone with high sensitivity and a high band by providing a wavy vibration suppressing part to outer ridge part of a metallic resonating board. CONSTITUTION:The metallic resonating board 5 consists of a diaphragm part 5a comprising the center flat part and the vibration suppressing part 5b formed by tilting the outer ridge part of the diaphragm part 5a in wavy form. A piezoelectric porcelain vibrator 6 is fitted to the lower face of the diaphragm part 5a. Further, the resonating board 5 is fixed to a cylindrical case 7 via the vibration suppressing part 5b. Through the constitution above, the resonating board 5 prevents the vibrating energy from being absorbed into the case 7. Further, since the resonating board 5 is formed spreading outward by the provision of the vibration suppressing part 5b, sound collecting effect is obtained. Thus, the ultrasonic wave ceramic microphone with the high sensitivity and the high band is obtained. |
