Abstract: An electrophotographic image forming apparatus may include a toner supply unit comprising a toner containing unit and a toner discharging unit having a toner outlet; a photoreceptor unit comprising a photoreceptor; a development unit comprising a development roller that supplies toner to develop the electrostatic latent image on the photoreceptor and a supply roller that supplies toner to the development roller; a first toner supply member that supplies toner of the toner containing unit to the toner discharging unit; and a second toner supply member that transports toner of the toner discharging unit to the toner outlet, wherein the first toner supply member is located in a second quadrant from among first through fourth quadrants based on a vertical line and a horizontal line which intersect at the second toner supply member, and wherein the photoreceptor, the supply roller, and the development roller are located in the fourth quadrant.

Abstract: A developing unit mounted on an image forming apparatus is provided. The developing unit includes a housing, a developing agent storage chamber that is provided inside the housing and in which a developing agent is stored, a developing chamber that communicates with the developing agent storage chamber, a path on which the developing agent is moved from the developing agent storage chamber to the developing chamber, and an opening/closing unit that is provided on the path and is open/closed while interlocking with an operation of mounting the housing on the image forming apparatus. Thus, a leakage of the developing agent can be prevented, and detachment of the developing unit can be easily performed.