| 摘要 |
PROBLEM TO BE SOLVED: To shorten the time to output a single color toner image in an image forming device provided with a multiple number of image forming parts and an intermediate transfer belt. SOLUTION: In this image forming device, 4 pieces of image forming parts Pd, Pc, Pb, Pa are installed along the direction of rotation (direction of arrow R31) of the intermediate transfer belt 31 in this order from upstream side. When a single color mode is selected, the output time of a black toner image of single color can be shortened by making circumferential velocity of the intermediate transfer belt 31 faster after primary transfer of the single color black toner image is carried out from a photoreceptor drum 11a to the intermediate transfer belt 31 until the start of the secondary transfer. |
