Patent ID: 8654417

Claim:
An image reading apparatus comprising: a transport unit which transports a document placed on a paper feed tray to a paper discharge tray along a transport path; a first reading unit which reads one surface of the document transported by the transport unit and generates first read data of a front end portion or a rear end portion of the one surface of the document; a second reading unit which reads the other surface of the document transported by the transport unit and generates second read data of a front end portion or a rear end portion of the other surface of the document; an edge detection unit which performs enhancement processing and binarization processing on the first read data and the second read data and detects edges based on the processed first read data and the processed second read data; and a determination unit which determines that there is double feeding of documents by the transport unit when the edge detection unit detects a plurality of edges from at least either the processed first read data or the processed second read data, wherein the determination unit determines that there is double feeding of documents by the transport unit when the edge detection unit detects from the processed first read data a plurality of edges in one of the front end portion and the rear end portion of the one surface of the document and detects from the processed second read data a plurality of edges in the opposite end portion of the other surface of the document to the one end portion of the one surface of the document.