| 摘要 |
PROBLEM TO BE SOLVED: To construct a system such as a TV telephone system, without increasing the scale or the weight of a portable telephone set. SOLUTION: A digital connector 10 and an analog connector 11 of a portable telephone A are connected via a digital signal line 41 and an analog signal line 42 to a digital connector 21 and an analog connector 22 of a TV telephone system B. Afterwards, when a control part 17 detects an instruction to use a TV telephone device B as well, based on a control signal from the control signal input/output terminal of the digital connector 10 or instruction from an operating part 16, the switching of first to fourth switches 12 to 15 is controlled, the external audio output terminals of a built-in microphone 1 and analog connector 11, external digital input terminals of encoding modulating part 3 and digital connector 10, external digital output terminals of encoding demodulating part 7 and digital connector 10 and external audio input terminals of a built-in speaker 9 and analog connector 11 are respectively connected. |
