US Patent 7885583 Development device and image forming apparatus

An aspect of the invention provides a development device including a rotatable development sleeve which supplies developer to a photosensitive drum, the development sleeve being disposed such that a rotational axis of the development sleeve is orientated toward a vertical direction; a conveying screw which conveys the developer along a rotational axis direction of the development sleeve; and a developer supply guide which guides the developer conveyed by the developer conveying device to the development sleeve. The plural developer supply guides are disposed at predetermined intervals in the rotational axis direction of the development sleeve and between the development sleeve and the conveying screw.