| 摘要 |
PURPOSE:To erase an unnecessary black image which appears on a part other than the image of an original by detecting a dark part with the aid of reflected light from an original surface by preliminary scanning and removing charges on corresponding photosensitive body. CONSTITUTION:A dark part detector 180 is movably provided between a lens block 8 for variable magnification and a mirror 9 as a detection means for detecting the dark part with the aid of the reflected light from the original surface. The preliminary scanning is performed separately from the scanning for forming an image and the reflected light from the original surface by the photoirradiation of an exposure lamp 4 is received by a line sensor 131. An output from the line sensor 131 is used to identify a black area on image information, so that the area where the original does not exist is detected as the dark part and the surface charges of the photosensitive drum 10 corresponding to the dark part can be removed. Thus, the high-quality copied image without the unnecessary black image can be obtained. |
