Condenser microphone structure

Condenser microphone structure which comprises a microphone housing, a condenser microphone accommodated in the microphone housing to produce a sound signal indicative of a voice sound, first and second terminal connecters provided on the microphone housing in the neighborhood of each other under an insulated state from each other.

Each of the first and second terminal connecters including a helical spring portion, and an end portion integrally formed with the helical spring portion, the helical spring portion and the end portion being made of an electrically conductive material, the end portions being electrically connected with the condenser microphone to discharge the sound signal from the condenser microphone through the first and second terminal connecters, and an insulating member accommodated in the microphone housing to retain the condenser microphone and the first and second terminal connecters with the microphone housing and to insulate the first terminal connecter from the second terminal connecter. The condenser microphone thus constructed can cause high frequency noises to be reduced to as a small level as possible, and can be produced at a relatively low production price and at a considerably short production period.

As such a conventional condenser microphone structure assembled in a cellular phone to enable communications with other cellular phones, there has so far been proposed and developed a wide variety of condenser microphone structures which areknown as being small in size and as having one or more terminal connecters electrically connected with parts or elements forming part of the cellular phone.

The conventional condenser microphone structure thus constructed is operated to generate a sound signal with the condenser microphone serving to transform a voice sound into the sound signal when receiving the voice sound from the exterior of thecellular phone.

The conventional condenser microphone structure, however, encounters such problems that the condenser microphone tends to receive high frequency noises through the terminal connecters other than voice sounds, resulting from the fact that theterminal connecters each made of a metal plate material has a relatively large surface area. In addition, the conventional condenser microphone structure is produced through the steps of punching a sheet metal, and bending the punched sheet metal by ametal mold high in precision to produce a terminal connecter in the form of a plate having a uniformed shape as required by customers.

The metal mold high in precision needed for production of the conventional microphone structure leads to the fact thatthe metal mold inevitably becomes at a markedly high production price and needs a relatively long production period for producing the metal mold and punching and bending a sheet metal. In the case of the metal mold low in precision, on the other hand,unstable electric connections are liable to be caused between the terminal connecters and the board terminals and between the terminal connecters and the condenser microphone when the terminal connecters terminal connecters are assembled with theinsulator and the condenser microphone.

It is, therefore, an object of the present invention to provide a condenser microphone structure which can reduce high frequency noises to as a small level as possible.

It is another object of the present invention to provide a condenser microphone structure which can be produced at a relatively lower production price and at a considerably shorter production period without any metal mold needed to be used forproducing terminal connecters forming part of the condenser microphone structure.

It is a further object of the present invention to provide a condenser microphone structure which can realize a stable electrical connection between the elements or parts forming part of the condenser microphone structure.

According to a first aspect of the present invention, there is provided a condenser microphone structure, comprising: a microphone housing formed with an opening; a condenser microphone accommodated in the microphone housing and partly exposed tothe exterior through the opening to produce a sound signal indicative of a voice sound after receiving the voice sound through the opening; a pair of terminal connecters consisting of first and second terminal connecters provided on the microphonehousing in the neighborhood of each other under an insulated state from each other, each of the first and second terminal connecters including a helical spring portion, and an end portion integrally formed with the helical spring portion, the helicalspring portion and the end portion being made of an electrically conductive material, the end portions being electrically connected with the condenser microphone to discharge the sound signal from the condenser microphone through the first and secondterminal connecters; and an insulating member accommodated in the microphone housing to retain the condenser microphone and the first and second terminal connecters with the microphone housing and to insulate the first terminal connecter from the secondterminal connecter.

According to a second aspect of the present invention, A cellular phone, comprising: a cellular phone housing; a printed circuit board unit including a printed circuit board accommodated in the cellular phone, and first and second board terminalsmounted on the printed circuit board in spaced and insulated relationship with each other; a microphone housing formed with an opening; a condenser microphone accommodated in the microphone housing and partly exposed to the exterior through the openingto produce a sound signal indicative of a voice sound after receiving the voice sound through the opening;

As will be understood from the foregoing description, the condenser microphone structure according to the present invention can reduce high frequency noises level to a small value as compared with that of the conventional condenser microphonestructure, viz., can cause high frequency noises to be reduced to as a small level as possible. The condenser microphone structure according to the present invention can be produced at a relatively low production price and at a considerably shortproduction period. The condenser microphone structure according to the present invention can realize a stable electrical connection between the terminal connecters and the board terminals.