| 摘要 |
PURPOSE:To prevent a black stripe from being formed in normal copying operation owing to the presence of untransferred toner resulting from parallel conveyance by making a shift by delta/2 in erasure reference position between parallel conveyance and normal conveyance when the gap between sheets of transfer paper is delta. CONSTITUTION:When images are transferred to both sheets of transfer paper while the gap is formed between both sheets of transfer paper, there is no untransferred toner present at a position on a photosensitive body which corresponds to the gap. The amount of untransferred toner causes no trouble when the number of numbers of parallel conveyance copying is small, but when the number of times is large, a black stripe is formed on an image possibly if normal copying operation is performed in case of a defect in cleaning. For the purpose, the gap between sheets of transfer paper is erased previously during the parallel conveyance to inhibit a toner image from being formed during development. When the gap between the sheets of transfer paper is delta, the transfer reference position in the parallel conveyance is shifted from that in the normal copying operation by delta/2 to reduce an image absence part after transfer to half, i.e. delta/2. |
