| 摘要 |
PURPOSE:To reduce sharply wore material cost and construction cost by eliminating the need for wiring for control, by operating a switch circuit by providing a priority encoder. CONSTITUTION:A video signal, when supplied to vedeo signal channel CH1, is detected by detecting circuit VD1, whose detection output is supplied to input 1 of priority encoder PE, which generates an output and operates switch change-over circuit EX to turn on only switch SW<1> is connected to video signal output VO. At this time, only switch BW1-BWn of answer signal channels CS1-CSn turns on and the others turn off, thereby sending answer signal AS out to only answer signal channel CS1. Encoder PE, when the detection output is supplied to any of inputs 1- (n), sends start signal ST out to CRT hard-copy device HCP. |
