| 摘要 |
PURPOSE:To deliver a broadcast exclusively to specific receivers as well through a single transmission line, by providing a call signal transmitter, etc. capable of sending call signals that control parts of receivers respectively respond to. CONSTITUTION:A call signal selected by a selection part 10 is sent from a call signal transmitter 9 to the input terminal 2a of each receiver 2 through a signal synthesis part 11, an output terminal 1a, a transmission line, and a branch part 4. At a receiver 2 which corresponds to said call signal among many receivers 2, the call signal is inputted through a signal separation part 12 to a call signal reception part 16, which generates an output to operate a switch control part 17, closing a switch 13. In this state, when the voice transmitter 6 of a transmitter 1 sends a voice signal to the transmission line 3 through the signal synthesis part 11 and output terminal 1a, the voice signal reaches a loudspeaker 14 through the switch 13 to output a voice. |
