Patent ID: 8112018

Claim:
A developing unit comprising: a developing unit body having a toner inlet, the developing unit body having a main frame with an open upper surface, and a cover frame coupled to the main frame and enclosing the open upper end of the main frame, the cover frame defining a top wall of the developing unit body, said main frame including a first rib extending upwardly from a bottom surface thereof, said cover frame having a second rib extending downwardly from a top surface thereof toward said first rib and spaced therefrom, said first and second ribs having a length less than a width of the developing body; a developing roller mounted in the main frame of the developing unit body; a toner feeding unit in the main frame for feeding toner charged through the toner inlet to the developing roller, the toner feeding unit including first and second spaced-apart augers, said first auger being on a first side of said ribs and said second auger being on a second side of said ribs, said ribs forming a circulation path between the augers; a toner feeding belt coupled to a middle portion of the second auger for supplying toner from the inlet to the second auger, the toner feeding belt being driven by the second auger; and a doctor blade positioned for controlling thickness of the toner supplied to the developing roller and being integrally formed with the cover frame.