| 摘要 |
<P>PROBLEM TO BE SOLVED: To earlier and more surely detect signs that a recording material having an image formed thereon may crease. <P>SOLUTION: An image forming apparatus 100 uses invisible toner to form an invisible image of regular segments on a paper. The invisible image of segments on the paper is read by a sensor 45 after fixing processing to judge whether the regularity is disordered. If it is judged that the regularity is disordered, information relating to the occurrence of creases of the paper is outputted. A user is thereby informed of an occurrence of creases before the occurrence of creases exerting a serious influence upon image quality. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
