Patent ID: 8577263

Claim:
A developing device comprising: a developing unit comprising a developing frame defining therein a developing chamber, and a developing roller rotatably disposed in the developing chamber; and a developing agent unit comprising a developing agent container that accommodates therein a developing agent, and an agitator disposed in the developing agent container and rotatable about a rotation axis in a rotational direction to agitate the developing agent, the developing agent container including an arcuate bottom wall whose center of radius of a curvature is coincident with the rotation axis, and an arcuate protruding wall protruding from the bottom wall toward the developing chamber and positioned downstream of the bottom wall in the rotational direction, the arcuate protruding wall being formed with an opening providing a fluid communication between an interior of the developing agent container and the developing chamber, the bottom wall having a lowermost point, and the opening having a downstream end in the rotational direction in an operational state, the bottom wall and the arcuate protruding wall having inner surfaces extending diagonally upward from the lowermost point to the downstream end in the operational state, wherein the arcuate protruding wall is disposed above a supply roller.