| 摘要 |
PROBLEM TO BE SOLVED: To prevent paper from being wasted by making an optical system execute feeding operation for delayed sheet material again in timing corresponding to next optical scanning after completing optical scanning operation once. SOLUTION: In the case of obtaining two copies by consecutive copying, first copying paper is normally carried but second copying paper is faultily fed at the time of paper-feeding. It is assumed that a preresist sensor can not detect the leading edge of the paper due to slip or the like though it should detect it at a point C. In such a case, the feeding operation of the paper positioned at the uppermost part in a cassette is executed again (point D) in the midst of the advancing operation of the optical system which does not participate in image-forming. Thus, the leading edge of the paper which can not reach the nip of a separation/carrying roller because sufficient carrying amount is not obtained due to the slip between a paper feeding roller and the paper on the first try can enter the nip of the separation/carrying roller by the second paper-feeding, whereby ordinary copying sequence can be started. |
