| 摘要 |
PURPOSE:To stop driving of a copying machine and to suppress generation of a cleaning defect by detecting overlapped feed of paper from a double-side tray and stopping driving of the copying machine prior to starting of an exposing operation. CONSTITUTION:Conveyance change-over selectors 16, 18 are changed over to positions 16b, 18b of dotted lines and paper is guided by the selector 16 and is delivered onto a discharge paper tray 15 on the outside of the machine in the stage of performing a copying operation in an ordinary copying mode. The copying operation on the front of the copying paper is first carried out in the case of performing the copying operation in a double-side mode. More specifically, the selectors 16, 18 are changed over to the positions 16a, 18a of solid lines and the copying paper fed from a paper feed cassette 9 is delivered to a double-side tray 13 via selectors 16a, 18a after the required copying operation. When plural sheets of the copying paper are simultaneously fed by feed rollers 23 for the purpose of copying the rear side, the feed is detected by an overlap feed detector 23 which emits an overlap feed detection signal to operate a control part 27. Said part outputs a control command to a driving part 28 to stop a scanning mechanism 3, a photosensitive drum 6, etc. The drum 6 is thus not exposed and therefore the generation of the cleaning defect is obviated. |
