| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of reliably determining the 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 that detects opening of a document feeding unit 3 covering platen glass; a second open/close detection sensor 26 that detects opening of the document feeding unit 3 at a pre-set threshold angle; and a document size determination unit 71 that, when the opening of the document feeding unit 3 at the threshold angle is not detected and the open and close of the document feeding unit 3 is detected, acquires third determination data by front side position determination scan in which a scanner 21 scans LED arrays on the depth side in a main scanning direction that are only partially turned on, acquires forth determination data by determination scan in which the scanner 21 scans the plurality of LED arrays 241a to 241k on the front side in the main scanning direction that are only partially turned on, and determines the size of the document in the main scanning direction on the basis of the third determination data and the fourth determination data. |
