Sheet feeding apparatus, image reading apparatus equipped with the same, and method of detecting double feed

摘要

A sheet feeding apparatus includes two transport devices arranged in a sheet guide that guides a sheet from a stacker to a processing position for reading an image or printing. A double feed detection device is arranged between the transport devices for detecting a double feed of the sheets over a predetermined length region (measurement length). A sheet length recognition device is provided for recognizing at least two portions of a length of the sheet stacked on the stacker in a transport direction, and a judgment device is provided for judging the double feed of the sheets based upon detection data from the double feed detection device. The judgment device judges the double feed of the sheets according to detection data of one measurement region selected from a plurality of measurement regions based on information obtained from the sheet length recognition device.