Developing unit.

摘要

A developing unit comprises a developer container (410) having an agitation space (412) for agitating developer therein and a toner hopper (420) for feeding toner to the agitation space (412) of the developer container (410). A lower wall (421) of the toner hopper (420) includes a toner drop port (426) allowing toner to fall into the aforesaid agitation space (412). On a surface of the lower wall (421) exposed to the agitation space (412), disposed is a partition wall (427) surrounding the periphery of the toner drop port (426). The partition wall (427) defines a non-agitation space (430). The toner is allowed to fall from the toner drop port (426) smoothly into the agitation space (412) through the non-agitation space (430) which is not affected by the agitation.