IMAGE FORMING APPARATUS

An image forming apparatus is capable of accurately reading out a document without various data transmission between a document feeding section and a document reading section. The reading position setter sets a fresh document reading position (RP3) at a position where no foreign object (F) adheres. A shift distance calculator calculates a shift distance (Z) between an upstream-most reading position (RP2) and the refresh document reading position (RP3). A delay time calculator calculates delay time based on the calculated shift distance (Z). A start signal sender instructs the document reading section to start reading a document (P) when the leading end of the document (P) reaches the upstream-most reading position (RP2). An ASIC outputs the instruction to start reading the document to an A/D with a delay of the feed delay time found by the delay time calculator to instruct an image sensor to start reading the document (P).