Patent ID: 7463843

Claim:
A developing device comprising: a toner; a casing arranged to accommodate the toner; a developing roller fixed rotatably on the casing; an elastic blade in contact with a circumferential surface of the developing roller; a seal member arranged between the developing roller and a wall surface of the casing, the seal member in contact with the circumferential surface of an end portion of the developing roller and a side surface of a tip end of the elastic blade; and a cutout portion provided in the seal member at a side surface of the seal member making contact with the side surface of the tip end of the elastic blade and in a side located closer to the wall surface of the casing than the elastic blade in a radial direction of the developing roller; wherein the seal member includes a first seal member arranged to make contact with the circumferential surface of both end portions of the developing roller so that a side surface of the first seal member makes contact with the side surface of the elastic blade, and a second seal member arranged between the first seal member and the wall surface of the casing, the second seal member having the cutout portion.