Patent ID: 7493066

Claim:
A developing device comprising: a development roller having an elastic outer layer and a compaction mechanism; and a development roller cleaning blade that is in contact with the development roller to clean a surface of the development roller, wherein θ is an angle of a contact face of the development roller cleaning blade relative to a perpendicular line v perpendicular to a generating line Ø passing through a rotational axis of the development roller at a contact point where a tip end of the development roller cleaning blade is pressed against and in contact with the development roller, a is an angle of a rising contour of a deformed portion of the elastic outer layer that is deformed by pressure of the development roller cleaning blade against the development roller relative to the perpendicular line v, a hardness of the development roller and an attitude of the development roller cleaning blade are set to achieve a relation a>θ, and the elastic outer layer is made of a rubber having a JIS A hardness of from 30 to 50 degrees.