| 摘要 |
PROBLEM TO BE SOLVED: To surely prevent the leakage of secret information of a black image by making easily specifiable an image forming device from an image on a recording medium with the black image formed. SOLUTION: A driving roller 214, a tension roller 320c and a supporting body 331 are supported by a frame 300 so as to be freely moved in the vertical direction, and also, a part separation mechanism 330 for vertically moving an elevation bar 314 in accordance with the rotation of a motor 308 is installed. At a black image forming processing, the driving roller 214, the tension roller 320c and the supporting body 331 are moved downward by the mechanism 330, a transfer/carrying belt 216 and transfer devices 225c and 225d are separated from photoreceptor drums 222c and 222d included in image forming stations Pc and Pd for forming magenta and cyan images, and only the image forming processing related with the black image and the image of discrimination information by image forming stations Pa and Pb is validated. |
