| 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 (platen cover) 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 by the second open/close detection sensor 26 and the open and close of the document feeding unit 3 is detected by the first open/close detection sensor 35, acquires third determination data by determination scan in which a scanner 21 scans a plurality of LED arrays 241a to 241k around a center line on a 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 acquired third determination data. |
