| 摘要 |
PURPOSE:To prevent a counter from being used illegally by outputting a check signal from a main body side to the counter side prior to a drive signal and then starting copying control on the basis of this signal and an answer signal which is shifted in phase. CONSTITUTION:When a count-up signal CO200 from a copying machine arrives at a connector 23, a micro-CPU 12 detects the count signal and outputs the answer signal AK201 to the copying machine. The signal 200 consists of the counter drive signal and check signal 200b and two check signal pulses are sent out before the drive signal; and it is checked whether or not the signal 201 is outputted in out-of-phase relation with them and when so, the drive signal is held for a time shown by a solid line. When the signals CO and AK are outputted at timing points t0 and t1 in opposite-phase relation as shown in a figure, the copying machine decides that they are outputted normally, and then holds a main relay on and also holds the counter drive signal for the time shown by the solid line. Consequently, the counter is prevented from being used illegally and driven illegally owing to its malfunction which accompanies no copying operation. |
