| 摘要 |
PURPOSE:To develop toner sticking to a seal member at a no-picture part on reversal basis, clean it and prevent the toner from appearing on a copy as stains, by forming a pattern for image formation at an exposure position before image exposure starts. CONSTITUTION:The pattern 27 for image formation such as a mesh-dot or properly rough caterpillar image is formed at the exposure position before the starting position P of exposure of an effective image which is not transferred to transfer paper to maximum exposure width at right angles to the exposure direction. A blade is turned on and off, and then this image formation cycle is carried out only for only the next sheet. An erasing lamp 3 is turned on after the 2nd and succeeding sheets in consideration of the timing of the lamp 3 to erase an image charged electrostatically by a charger 2. Further, a slight cleaning defect is caused without turning on nor off the blade, so the image forming cycle for cleaning the seal member is performed periodically. |
