Patent ID: 8824937

Claim:
A developing device, comprising: a case for housing a developer; an agitating member arranged in the case, the agitating member including a shaft center and a screw forming portion arranged around the shaft center and configured to agitate and convey the developer while rotating; a magnetic roller arranged in the case to face the agitating member, the magnetic roller including a rotary shaft and a plurality of magnetic poles to carry the developer on a circumferential surface of the magnetic roller, the magnetic poles successively moving into positions to face the agitating member and the magnetic pole that faces the agitating member defining a pumping pole that pumps up the developer from the agitating member to the circumferential surface of the magnetic roller; a layer thickness restricting member arranged to face the magnetic roller and configured to restrict the layer thickness of the developer supplied from the agitating member to the magnetic roller to a predetermined thickness; a plate-like flexible member facing the layer thickness restricting member along a rotation axis direction of the magnetic roller and extending toward the circumferential surface of the magnetic roller at a side upstream of the layer thickness restricting member in a rotating direction of the magnetic roller, the flexible member extending toward a position on the circumferential surface of the magnetic roller downstream of the pumping pole in the rotating direction of the magnetic roller; and an auxiliary developer storing portion arranged along the rotation axis direction of the magnetic roller to face the circumferential surface of the magnetic roller between the layer thickness restricting member and the flexible member; wherein the plate-like flexible member forms a wall surface on an upstream side of the auxiliary developer storing portion in the rotating direction of the magnetic roller along the rotation axis direction of the magnetic roller.