Patent ID: 7552924
Filing Date: 2009-06-30
Classification: B65H

Abstract:
1. A sheet feeding apparatus comprising: a stacker for stacking a sheet, a sheet guide for guiding the sheet from the stacker to a predetermined processing position, first and second transport devices arranged in the sheet guide for transporting the sheet, a sheet length recognition device for recognizing at least two kinds of length of a sheet placed on the stacker in a transport direction, an ultrasonic double feed detection device arranged between the first transport device and the second transport device for detecting a double feed of sheets over a measurement region of the sheet, said double feed detection device comprising an oscillating element and a receiving element facing each other to allow the sheet to pass therebetween, and a judgment device for judging the double feed, said judgment device setting non-measurement regions at a leading edge and a trailing edge of the sheet in the transport direction based upon the length of the sheet recognized by the sheet length recognition device and judging the double feed based on detection data of one measurement region shorter than the length of the sheet and excluding the non-measurement regions.