Patent ID: 8444142

Claim:
A multifeed processing apparatus comprising a control unit and being connected to a multifeed detecting mechanism and an image reading mechanism, wherein the control unit includes a calculating unit that calculates a shape of a peripheral edge of a medium from any one or both of an output of the image reading mechanism and an image of the medium read by the image reading mechanism, a detecting unit that detects a change in the shape on a boundary of an overlap detected portion, from the shape calculated by the calculating unit and a position of the overlap detected portion detected by the multifeed detecting mechanism, a determining unit that, when the change in the shape is not detected by the detecting unit, determines whether a change similar to the change in the image of the overlap detected portion continues up to the peripheral edge of the medium, from a plurality of the images from the overlap detected portion to the peripheral edge of the medium, and a deciding unit that determines a case where the change in the shape is detected by the detecting unit, as a multifeed, and determines a case where the determining unit determines that the change in the image continues, as a multifeed.