| 摘要 |
In a land mobile radio telephone apparatus, a microphone unit for inputting speeches to be transmitted in incorporated in a plug that can be connected to a cigar lighter socket provided near a driver's seat in a vehicle, and the plug with the microphone unit built therein is connected to a radio telephone apparatus body via cables for supplying power from a power source and a cable for inputting the speech voices. A speaker unit is built in the radio telephone apparatus body. An end portion of a casing of the plug is formed into a tubular shape, and the microphone having a directivity is incorporated in the tubular end portion in such a manner that it can be semi-fixed. Directivity of the microphone is thus directed toward the driver. The microphone unit has a directivity adjusting mechanism, and is supported by supporting member having a vibration-proof effect. Furthermore, a noise removing circuit is provided between the microphone unit and a circuit unit for suppressing sound coupling between the microphone unit and the speaker unit. |
