Patent ID: 8682211

Claim:
A developing device frame unit to which a regulating member for regulating a layer thickness of a developer on a developer carrying member is mountable, said developing device frame unit comprising: a developing device frame having a seal forming portion; a first sealing member which is provided at one longitudinal end of said developing device frame to prevent the developer from leaking from said developing device frame unit in an axial direction of the developer carrying member when the developer carrying member is mounted on said developing device frame; a second sealing member configured to provide a seal between the regulating member and said developing device frame to prevent the developer from leaking out of said developing device frame unit when the regulating member is mounted on said developing device frame, wherein said second sealing member comprises an elastomer resin material that is injection molded into said seal forming portion, and wherein said second sealing member is connected to said first sealing member; and a protrusion protruded from said second sealing member by injection molding said second sealing member, and wherein said protrusion is formed between an injection port through which the elastomer resin material is injected into said developing device frame and said first sealing member.