Patent ID: 7853175

Claim:
An image forming apparatus for forming an image on a sheet, comprising: a casing; a plurality of process cartridges arrayed in line in an arraying direction, each process cartridge having a photosensitive drum; a conveyer belt that conveys the sheet; a drawer detachably holding the plurality of process cartridges and constantly supported to the casing, the drawer being movable in a pull-out and push-in direction parallel to the arraying direction relative to the casing to one of a first position where each photosensitive drum is in direct confrontation with the conveyer belt, a second position where all of the plurality of process cartridges are positioned out of the casing, and a third position further outward, relative to the casing in the pull-out direction, of the second position for removing a jammed sheet; and a regulation mechanism that regulates movement of the drawer and comprising: a first regulation mechanism that maintains the drawer at the second position engaged with the casing and prevents the drawer from moving toward the third position in a phase where a process cartridge positioned at a most upstream side in the pull-out direction is held in the drawer, the first regulation mechanism allowing the drawer to move to the third position from the second position at a phase where the process cartridge positioned at the most upstream side is removed from the drawer; and a second regulation mechanism that maintains the drawer at the third position engaged with the casing.