| 摘要 |
PURPOSE:To obtain the best exposure easily by arranging two identical slit rolls oppositely at a left and a right symmetrical position on the optical axis of a photosensitive drum. CONSTITUTION:At a left and a right symmetrical position on the optical axis 1A of a photosensitive drum 1, two identical slit rolls 2 and 3 are arranged oppositely, a rotation driving mechanism for said slit rolls 2 and 3 is provided to make an adjustment to exposure for the best copying, and a step motor 6 drives the rolls through a gear 4. Those slit rolls are step cams each having an (n)-step peripheral contours PCs with radii a1, a2-an from the center C of rotation, and the rolls 2 and 3 are rotated in the opposite direction to adjust the exposure. |
