Patent ID: 7493068

Claim:
A developing unit configured to supply developer to the surface of a developer support member installed in an image forming device, comprising: a first agitation transport member comprising a rotary shaft, a helical blade formed on the outer circumference of the rotary shaft, a transport region configured to transport developer to one side in the axial direction, and a supply region arranged upstream of the transport region to be coaxial with the transport region and configured to supply externally replenished toner to the transport region; a second agitation transport member; a housing in which the first and second agitation transport members are rotatably arranged in the interior thereof, a first gap in the radial direction formed between an outer circumferential portion of the supply region of the first agitation transport member and an inner circumferential portion of the housing facing the supply region being smaller than a second gap in a radial direction formed between an outer circumferential portion of the transport region of the first agitation transport member and an inner circumferential portion of the housing facing the transport region; and a bulkhead member being arranged between the first agitation transport member and the second agitation transport member, and the bulkhead member having openings connecting the first agitation transport member side and the second agitation transport member side at both ends of the second agitation transport member in the axial direction, the bulkhead member also having a partition member being connected to the housing and dividing the first agitation member and the second agitation member in a horizontal direction, and a guide being connected to the housing on a portion opposite the connection of the partition member.