| 摘要 |
PURPOSE:To prevent the start of unnecessary copying operation for the originals of more than the specified length by generating an original-detecting pulse only when the original detector detects the leading end of the next original and controlling the start of the copying operation based on this pulse. CONSTITUTION:When the 1st original detector 19 becomes ON from OFF upon insertion of an original, an FF 24 is cleared and a gate circuit 25 is opened. When the original is conveyed and the 2nd original detector 20 goes ON, a copying start pulse is supplied to the FF24 via OR circuit 27, by which the FF 24 is set and the pulse is supplied to a control circuit 26. Then, the control circuit 26 controls the operation of each part in synchronization with the copying operation. However, unless the first original detector 19 which has once gone OFF goes ON by detecting the next original, the FF 24 is held set and the gate 25 is held closed and therefore the copying start pulse from the control circuit 26 is prevented from passing therethrough, hence the unnecessary copying for the original longer than the specified is prevented. |
