Patent ID: 7933534

Claim:
A developing device frame unit comprising: a developing device frame having a seal forming portion; a one end sealing member which is provided at one longitudinal end of said developing device frame and which is contactable to a surface of a developer carrying member 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 unit; an other end sealing member which is provided at the other longitudinal end of said developing device frame and which is contactable to the surface of the developer carrying member 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 unit; a blade sealing member configured to provide a seal between a regulating member mountable on said developing device frame unit 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 unit, wherein said blade sealing member comprises an elastomer resin material which is injection-molded with a metal mold and which is provided in said seal forming portion where said one end sealing member and said other end sealing member are provided, said blade sealing member connecting said one end sealing member and said other end sealing member with each other; and a protrusion comprising a squeezed-out portion of the elastomer resin material, wherein the squeezed-out portion is provided by injecting, into a space defined by the metal mold, said seal forming portion, said one end sealing member, and said other end sealing member, a volume of the elastomer resin material that is larger than the volume of the space.