| 摘要 |
<p>PURPOSE:To obtain a double feed detector having a simple constitution at a low cost, by installing a distance measurement sensor for measuring the distance up to a sheet surface on a placing part, and detecting the double feed of the sheet on the basis of the distance measured by the distance measurement sensor. CONSTITUTION:A sheet type original document D placed on a placing tray 3-1 is fed from the lowest document by a feeding roller 3-2a, and transferred at a prescribed position on an original document board 2 by a belt transfer part 3-4 opposed to the original document board 2 through a reversing transfer part 3-3. After light exposure, the sheet type original document D is returned to the uppermost part of the placing tray 3-1 through the second reversing transfer part 3-5 and a discharge part 3-6. In this case, the distance before transfer up to the uppermost part of the sheet placed on the placing tray 3-1 is detected by a distance measurement sensor 37, and the distance after transfer is detected, and the thickness of the supplied sheet type original document is obtained from the difference of both the detected distances. On the basis of the thickness, the (double feed of the sheet type original document is detected, and sheet control is executed.</p> |
