| 摘要 |
PURPOSE:To prevent occurrence of defective copies such as a black band copy or image omission copy etc. by providing a detecting device that detects the maximum exposure width on the back of exposure position to a transparent photosensitive body, and making erasing of a latent image outside of the maximum exposure width by an erasing device. CONSTITUTION:A lens 8 is shifted to a position corresponding to magnification, and at the same time, scanning speed of a contact glass 2 also becomes a speed corresponding to the magnification and copying operation is executed. The maximum exposure width (w) is detected by a light detecting element array 14. That is, a transparent photosensitive body 4 is used as a photosensitive body, and the light for the maximum exposure width (w) passes through the transparent photosensitive body 4, and a light detecting element 13 in the maximum exposure width (w) of the light detecting element array 14 is exposed, and light detecting elements 13 outside of the maximum exposure width (w) are not exposed. By controlling to give detected information of maximum exposure width (w) to an eraser 15 and to make erasing of unexposed part outside of the maximum exposure width (w) of the transparent photosensitive body 4, erasing suitable for the image area is performed. |
