DEVELOPER CARTRIDGE, IMAGE FORMING APPARATUS AND METHOD OF INSTALLING/REMOVING DEVELOPER CARTRIDGE INTO/FROM IMAGE FORMING APPARATUS Russian patent published in 2012 - IPC G03B21/18 

FIELD: physics.

SUBSTANCE: image forming apparatus comprising a developer cartridge, includes a bottom part of the housing and a developer cartridge fitted in the bottom part of the housing and having a photosensitive carrier. The top part of the housing can be detachably fitted on the top of the bottom part of the housing and includes an upper clamping element for pressing the developer cartridge downwards. A lower clamping element fitted in the bottom part of the housing lies such that it presses the developer cartridge upwards. If the centre of rotation defines the axis of rotation of the photosensitive carrier included in the developer cartridge, two moments of force act on the developer cartridge: the moment of force applied to the developer cartridge by the upper clamping element, and the oppositely directed moment of force applied to the developer cartridge by the lower clamping element.

EFFECT: maintaining a fixed position of the photosensitive carrier included in the developer cartridge relative the image transfer roller after replacing the developer cartridge.