| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of reliably determining size of a document with a white background, even when the document is placed on platen glass without largely opening a platen cover.SOLUTION: An image forming apparatus includes: a first open/close detection sensor 35 for detecting opening of a document feeding unit 3 (a platen cover) covering platen glass; and a second open/close detection sensor 26 for detecting opening of the document feeding unit 3 at a pre-set threshold angle. When the opening at the threshold angle is not detected by the second open/close detection sensor 26 and open and close of the document feeding unit 3 is detected by the first open/close detection sensor 35, a document size determination unit 71 acquires third determination data by determination scan in which only a part near a center line of a main scanning direction in a plurality of LED arrays 241a to 241k is turned on by a scanner 21, and determines size of the document in the main scanning direction on the basis of the acquired third determination data. |
