US Patent 7929890 Image formation device and developer supply device

There is provided an image formation device, comprising: a holding body configured to hold thereon developer and to have a center axis extending in a main scanning direction; and a developer supply unit configured to supply the developer to the holding body through a traveling electric field, the developer supply unit having an opening through which a part of the holding body is accommodated in the developer supply unit. In this configuration, the developer supply unit comprises a sliding member configured to slide on at least a part of a surface of the holding body moving toward an outside of the developer supply unit through the opening.