Developing unit, image forming apparatus, and floating developer collecting method for developing unit

摘要

A suction duct that sucks air is provided downstream from a magnet roller that applies a developer to a photoconductor while rotating, in a direction of rotation of the photoconductor, and upstream of a surface potential sensor that measures surface potential of the photoconductor. Moreover, ribs for adjusting an air flow are arranged within the suction duct in such a manner that a width of an air flow passage formed by a rear end in a direction of air flow and a forward end of a nearest rib in the direction of air flow is narrowed from a rib installed upstream in the direction of air flow toward a rib installed downstream. The collection duct collects a floating developer by using a negative pressure.