An image forming apparatus, one of the influence of fluctuations in speed of the conveyor belt on the correction of the offset in the case of the ink coverage eliminated

摘要

The apparatus has an endless conveyor belt (35) driven by a roller (36) for transporting the copy paper. A number of image producing units (20Y,20M,20C,20K) are positioned along the conveyor belt which transfer a colour component image on to the copy paper and at the same time a lining up mark (23) on to the conveyor belt. A lining up mark detector (22) is located along the conveyor belt. The gap between the detector and one (20k) of the image producing units adjacent to the detector amounts to a whole number multiple of the periphery of the drive roller as is the gap between adjacent image producing units