| 摘要 |
PROBLEM TO BE SOLVED: To provide a directional capacitor microphone with improved directional characteristics so as to enhance the directional characteristics, while reducing the number of parts of the capacitor microphone, minimizing its thickness, and simplifying its assembly process. SOLUTION: There are provided with a support structure 20 to be positioned at an upper step of a fixed electrode 17 and to insulate the fixed electrode 17 and a metal case 11; and a FET to be positioned between the most upper step in the metal case 11 and the support structure 20, to be connected to the metal case 11 and the support structure 20 electrically and to amplify and convert a potential change by the change in the capacitance due to the vibration of a vibrating plate 103 between the vibration plate 103 and the fixed electrode 17 into a electrical signal. A printing circuit substrate 25 punched by a plurality of acoustic wave inflow holes 26 is included, the transfer of the acoustic wave to flow in the acoustic wave inflow holes 26 of the printed-circuit board 25 is delayed, and the fixed electrode 17 is electrically connected to the gate of the FET formed on the printed circuit board 25. COPYRIGHT: (C)2006,JPO&NCIPI
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