Patent attributes
A developing device includes a developer supporting member having an elastic layer and a surface layer, and a supply member for supplying developer to the developer supporting member. The surface layer is formed of a mixture containing at least an acrylic resin and a polyether type urethane resin. The developer supporting member and the supply member are configured so that the following equations are satisfied:20≦A1≦800.6≦D≦2.045+0.1×A1×D≦F×N≦65where A1 is a weight ratio (%) of the acrylic resin relative to a total weight of the acrylic resin and the polyether type urethane resin, F is an Asker F hardness (degree) of a surface of the supply member, and N is an overlap amount (mm) representing a biting amount of the supply member relative to the developer supporting member.
