Patent ID: 7190912

Claim:
An image forming apparatus comprising: a plurality of image bearing members, wherein each image bearing member is rotatable around an axis of rotation and bears a latent image; a charging unit that electrically charge the image bearing member; a light illuminating unit corresponding to each image bearing member, wherein the light illuminating unit illuminates light on a corresponding one of the image bearing members so as to form a latent image on the image bearing member; a developing unit corresponding to each image bearing member, wherein the developing unit develops the latent image on a corresponding one of the image bearing members to form a toner image; an intermediate transfer belt onto which the toner images on the image bearing members are transferred and from where the toner images are transferred onto a recording medium; a driving unit that drives and rotates the intermediate transfer belt; a supplying unit that supplies the recording medium to the intermediate transfer belt; and a detector corresponding to each image bearing member, wherein the detector optically detects a density of a toner image present on a corresponding one of the image bearing members, wherein at least two of the detectors are shifted in the direction of the axis of rotation of the corresponding image bearing member as compared to other detectors.