SHEET CONVEYER, AUTOMATIC DOCUMENT FEEDER PROVIDED THEREWITH, AND IMAGE FORMING DEVICE

摘要

PPROBLEM TO BE SOLVED: To provide a sheet conveyer capable of separating surely doubly conveyed sheets without damaging those as much as possible, and to separate the doubly conveyed sheets without spending an excessive time. PSOLUTION: This sheet conveyer is provided with a sheet feed part for feeding the plurality of sheets sequentially to a conveying route, three or more of roller pairs arranged in a prescribed position along the conveying route to convey the sheet while clamping it therebetween, a double conveyance detecting part for detecting a length of a double conveyance portion that is a duplicated portion when one portion of the sheet is fed doubly with the other sheet, a selection part for selecting two out of the three or more of roller pairs, and a conveyance control part for switching a conveying speed in at least one of the selected roller pairs. The selection part selects two roller pairs having a clearance capable of clamping the double conveyance portion therebetween, and the conveyance control part separates the sheet duplicated on the other sheet therefrom, by differing the conveying speeds each other in the selected roller pairs. PCOPYRIGHT: (C)2008,JPO&INPIT