| 摘要 |
PURPOSE:To eliminate a copying miss by using a light source for charge erasure which is divided into plural segments for erasing charges except in the image area of an electrophotographic sensitive body, and displaying the size of an original determined by the size of selected recording paper and copy magnification together with its position. CONSTITUTION:The light source 3 for charge erasure is constituted by arraying plural, e.g. 50-60 LEDs which are fractionized into segments to the overall width of a photosensitive drum 1 in parallel to its axis of rotation. Then, LEDs positioned in an area of the width size of recording paper to be supplied for copying are turned on on the basis of detection information on the width size to erase charges at an unnecessary area part during the rotation of the photosensitive drum 1. The light source 3 for charge erasure is rotated to, for example, a horizontal position through push-button operation; one end of a light transmissive sheet 7 which transmits luminous flux is arranged opposite to the light source and the other end is provided nearby the original reference surface of an original platen 4, so that the turn-on or turn-off range of the light source 3 for charge erasure is displayed and confirmed on the original platen 4. |
