Patent attributes
A developer supply cartridge detachably mountable to a main assembly of an image forming apparatus includes: a developer accommodating portion; a shutter portion movable between a closed position and an open position; and a movable portion for moving the shutter portion. The movable portion is movable between a first position where the shutter portion is positioned in the closed position. When the movable portion is positioned in a position other than a first position provided in an apparatus main assembly side of an image forming apparatus before being engaged with the first engaging portion, the movable portion is moved, until being engaged with the first engaging portion, to the first position by engagement thereof with a second engaging portion provided in the accommodate main assembly side.