Patent ID: 8725027

Claim:
An image forming device comprising: a main body housing; a plurality of process cartridges each of which accommodates recording agent of a specific one of colors used for image formation; a plurality of photoconductive drums each of which is configured such that an electrostatic latent image, to be developed with the recording agent of a specific one of the colors, is formed thereon; a belt unit comprising an endless belt wound around a pair of rollers inside the main body housing, the endless belt being configured such that an up-facing side of an outer surface thereof extends and travels in a predetermined direction; a drawer configured to hold the process cartridges and the photoconductive drums arranged along the predetermined direction above the belt unit, the drawer being movable between an attachment position where each photoconductive drum faces the up-facing side of the outer surface of the endless belt and a replacement position where at least one of the process cartridges is outside the main body housing; a pattern forming unit configured to form, on the up-facing side of the outer surface of the endless belt, a detection pattern corresponding to each color of the recording agent used for image formation; a detection sensor comprising a detection surface that faces the outer surface of the endless belt, the detection sensor being configured to read, through the detection surface, each detection pattern formed on the outer surface of the endless belt; a cleaning unit comprising a cleaning surface configured to be able to contact and clean the detection surface of the detection sensor; and an interlocking mechanism that causes the cleaning unit to clean the detection surface of the detection sensor with the cleaning surface in conjunction with movement of the drawer between the attachment position and the replacement position, wherein the attachment position of the drawer is lower than the replacement position, wherein in the attachment position, each photoconductive drum contacts the up-facing side of the outer surface of the endless belt, and wherein the interlocking mechanism causes the cleaning unit to clean the detection surface of the detection sensor with the cleaning surface in response to the drawer moving down to the attachment position from the replacement position.