| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the limit to the number of receivers in use, to improve the speech quality, to improve the freedom of use and to reduce the cost by eliminating the need for connection work of a line cable with a master set. SOLUTION: A cordless telephone set 1 and a key telephone set body 2, and the key telephone set body 2 and a cordless master set 20 are respectively set is a cordless configuration. The cordless set 1 is connected to the telephone set body 2 by transmitting/receiving an infrared signal. A call of the key telephone set body 2 is sent to the cordless master set 20 in an infrared signal and sent to a telephone exchange station of a telephone network through a trunk line contained by the cordless master set 20. Furthermore, a call from the trunk line is sent by the cordless master set 20 to the key telephone set body 2 in a infrared signal and speech is handled by the cordless handset 1. |
