Developing device, image forming apparatus, image forming system, and method of assembling developer supplying roller

摘要

A developing device includes a housing, a developer bearing roller, a first seal member, a second seal member, a second seal supporting member, and an urging member. The housing has an opening and is adapted to contain a developer. The developer bearing roller is arranged facing the opening and adapted to bear the developer. The first seal member abuts against the developer bearing roller along an axial direction thereof to prevent the developer from spilling. The second seal member abuts against an end, in the axial direction, of the developer bearing roller along a circumferential direction thereof to prevent the developer from spilling. The second seal supporting member supports an end, in a longitudinal direction, of the second seal member, and is attached to the housing such that a boundary section between the second seal member and the second seal supporting member faces the housing. The urging member is arranged along the axial direction of the developer bearing roller and is adapted to urge the first seal member toward the developer bearing roller by abutting against the first seal member. The urging member has, at an end in its longitudinal direction, an extending section extending up to a position between the boundary section and the housing.