| 摘要 |
PURPOSE: A video phone system using a 2-wired video phone system is provided to facilitate extension work of a monitoring device unit and a calling device unit by enabling the transmission between those two devices. CONSTITUTION: A monitoring unit(200) is connected to a calling device unit(300) through first and second communication lines(101,102), and an external signal mixing unit and an internal signal mixing unit transmits an initial call signal and a recall signal to the monitoring device unit. A call signal detection module detects the initial call signal with the recall signal, and a control unit outputs a control signal to a first power control unit when the initial call signal is discriminated.
|
