| 摘要 |
PROBLEM TO BE SOLVED: To recognize call termination to a portable telephone set by transmitting that a call is terminated to the portable telephone set to the receiver of a headphone part or the like and reporting that to a portable telephone set carrier while using a radio type headphone stereo system. SOLUTION: The portable telephone set 4 is provided with a detection part 7 and a transmission part 8 especially for the purpose and original parts can be used together for an antenna part 5 and a reception part 6. When the portable telephone set 4 receives call termination signals and the detection part 7 recognizes them, the transmission part 8 transmits the call termination signals to the outside by the same frequency as the reception frequency of the receiver 2 of the headphone part 3. The receiver 2 radio-receives them, mixes some noise or call termination sound to the headphone stereo system and makes a listening portable telephone set carrier surely recognize the call termination to the portable telephone set. The transmission power of the transmission part 8 is sufficient when it is the same level as the radio type headphone stereo system, a modulator is allowed to transmit the noise and the kind of signals can be any. |
