| 摘要 |
PURPOSE:To transfer a call from either of a handset and a base unit to the other during the service to a telephone of a line wire by operating intercom keys provided on the handset and the base unit connected to a telephone line. CONSTITUTION:A handset HS1 and a base unit BU2 connected to a telephone line 3 are provided with microcomputers and intercom keys, and communication between them is performed with radio waves. If an intercom key 253 on the BU2 is depressed during the service between the BU2 and a line wire 3, a relay circuit 232 holds the line wire by the control of a microcomputer 240. Next, a control signal is sent to the HS1, and a bell is sounded in the HS1. When the response from the HS1 comes to the BU2, the intercom call to the HS1 is possible in a telephone set 4 of the BU2. When the telephone 4 is hooked on after the intercom call, holding of the line wire 3 is released by the control of the circuit 232, and the service between the telephone of the line wire and the HS1 is possible. When the key 253 is depressed again after the telephone set 4 is hooked off, the tripartite service among the HS1, the BU2, and the line wire 3 is possible. |
