Patent ID: 7881634
Filing Date: 2011-02-01
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a plurality of units, each unit comprising an image bearing member for bearing a toner image, each unit being detachably mountable to a main assembly of the image forming apparatus; a belt for transferring the toner image from the image bearing member of each unit onto a transfer material; a plurality of transfer members, each transfer member corresponding to one of said plurality of units and being provided at a position in which the transfer member opposes a corresponding image bearing member of a corresponding unit through said belt, for transferring the toner image from the corresponding image bearing member; a moving mechanism for moving said plurality of transfer members between a first position and a second position in which each transfer member of said plurality of transfer members is moved farther from the corresponding image bearing member than the first position; current detecting means for detecting a current passing through each transfer member of said plurality of transfer members; and a recognizing portion for detecting a position of each transfer member of said plurality of transfer members, to which a voltage has been applied, on the basis of a detection result of said current detecting means, wherein a force, with which each transfer member of said plurality of transfer members presses said belt against the corresponding image bearing member when the transfer member is moved from the second position to the first position by said moving mechanism, is capable of pressing a corresponding unit of said plurality of units into a predetermined position in the main assembly of said image forming apparatus, and wherein said moving mechanism always performs, before said recognizing portion detects the position of each transfer member of said plurality of transfer members, an operation for moving each transfer member of said plurality of transfer members from the second position to the first position at least one time.