| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a radio hands-free system of a portable telephone set which is easily connected to any kind of a portable telephone set where high quality speech communication can conveniently be performed without directly operating a portable telephone body and which can extend battery life by drastically saving power consumption due to the design of low power operation that makes the system operate according to the state of transmission and reception as for the radio hands-free system of a portable telephone set. SOLUTION: This system includes a main device 200 which is operated by a battery provided in the main device itself and which is connected to an earphone/microphone terminal 110 of the portable telephone body 100. The device 200 inputs/outputs a sound signal and transmits/receives the inputted and outputted sound signals by radio. This system includes also a sub device 300 which operates by a battery provided in the sub device itself and which is connected to the device 200 by radio. The device 300 transmits/receives the sound signal, inputs/outputs the transmitted and received sound signals to/from an earphone 350 and a microphone 351 to transmit the sound signals to a user.</p> |
