Patent ID: 7944589

Claim:
An image forming apparatus, comprising: a document feeding section for feeding a document at a predetermined feeding speed; and a document reading section for reading a document at a document reading position, the document reading section including: a reading position setter which determines whether or not dirt adheres on an instant document reading position, and, when the reading position setter determines that dirt adheres on the instant document reading position, the reading position setter sets a fresh document reading position within a predetermined reading position range along a document feeding path where no dirt adheres; an image sensor; a distance calculator which calculates a shift distance between the fresh document reading position and an upstream end of the reading position shiftable range; and a time calculator which calculates a delay time based on the feeding speed and the calculated shift distance, wherein the document feeding section includes a start signal sender which sends a start signal to the document reading section when a predetermined portion of the document being fed reaches the upstream end of the reading position shiftable range, and the document reading section further includes a reading controller which allows the image sensor to start reading of the document after elapse of the delay time from the reception of the start signal.