| 摘要 |
PURPOSE:To realize a high-sensitive and stable-characteristic directional wave receiver by arranging plural vibrometers, where internal materials are supported in the housing by two diaphragms where piezoelectric elements are stuck, in a case in orthogonal directions. CONSTITUTION:Sound receiving of case 6 is the pressure gradient type; and since case 6 is operated in the mass control region by suspended rubber 5, response of the vibration speed for the acoustic pressure is fixed in the used frequency band. Meanwhile, the vibration system is formed in vibrometer 7 by mass of internal material 13 and the spring constant of diaphragms 9 and 10, and response of pressure change of diaphragms 9 and 10 for the speed of housing 8 indicates the phase characteristic having a gradient of +6dB/octave and -6dB/octave for frequency f0 peculiar to the vibration system or less and frequency f0 or more respectively. However, output voltage response of piezeelectric elements 11 and 12 for diaphragms 9 and 10 is independent of the frequency, and therefore, the phase characteristic above is response of the directional wave receiver. |
