US Patent 7079788 Developer cartridge and image forming apparatus

A cartridge is detachably mountable to an image forming apparatus and includes a first container, which contains a developer to be supplied into the image forming apparatus and a second container, which is rotatable to feed the developer toward the discharge opening. A developer discharge opening is provided at one longitudinal end of the first container. The second container accommodates a developer collected from the image forming apparatus. The first container is rotatably supported, at the other longitudinal end thereof, by the second container, which is unrotatably engageable with the image bearing member.