CONDENSER MICROPHONE

摘要

An elliptical condenser microphone easily using space is provided to reduce space of a condenser microphone occupying in the electronics by deforming a horizontal section of the condenser microphone into an elliptical shape. A metallic case(8) comprises a horizontal section of an elliptical shape and a horizontal surface having a sonic wave inducing hole and a bent-up end to fix inner components. A diaphragm plate(7) is arranged within the metallic case(8) and has an elliptical horizontal section. A diaphragm(6) is disposed on an upper of the diaphragm plate(7) and made of a metallic film plate. A spacer(5) made of an insulating material is located on an upper of the diaphragm(6) and sustains an air gap between the diaphragm(6) and a back plate. A base(4) having an elliptical horizontal section is arranged on an upper of the spacer(5) and maintains an insulating state of the case(8) and a back plate(3). The back plate(3) is made of a metal material having a charge-accumulated film and positioned on a surface facing the diaphragm(6). The back plate(3) is arranged within the base(4) to maintains the air gap through the spacer(5). A connecting ring(2) is located within the base(4) and on an upper of the back plate(3) and connects a gate of an FET(Field Effect Transistor) to the back plate(3). A printed circuit board(1) is inserted into the case(8) and has an elliptical horizontal section connected electrically to the case(8) and the connecting ring(2). The FET is placed on the printed circuit board(1).