| 摘要 |
PURPOSE:To reliably detect double feed or multi-feed in OCR or the like by providing means for applying force to sheets to be separated from each other at the time of multi-feed and means for detecting the length of a sheet along the feeding direction disposed upstream and downstream from the applying means. CONSTITUTION:If two sheets of document 2 are fed out in layers from a hopper 1, the first decision circuit 41 is adapted to decide a time t1 when two sheets of document stay in the first detector 34 and store it, and then two sheets of document and passed through a separating mechanism 37, threrby to make the double sheets of document shift from each other largely. After that, two sheets of document pass through the second detector 38, and the second decision circuit 42 is adapted to judge the period of time t2 of its stay in the detector and store it. A double-feed decision circuit 43 is adapted to compare both periods of time t1, t2 and if t2>t1, it is juged that document is doubly fed. Accordingly, if there are sheets of document different in thickness, lignt transmittivity and size, double-feed can be judged assuredly. |
