Patent ID: 8346137

Claim:
A developing device comprising: a developing container configured to accommodate a two-component developer that includes a toner and a magnetic carrier; a stirring/conveyance member configured to stir and convey the developer accommodated in the developing container; a developer bearing member configured to bear and convey the developer, the developer bearing member being provided so as to be able to rotate above the stirring/conveyance member; a fixed magnet configured to have a plurality of magnetic poles that includes a release pole for releasing the developer from a surface of the developer bearing member, the fixed magnet being fixed to the inside of the developer bearing member; a regulating blade configured to be disposed facing the developer bearing member so as to be downstream in the direction of rotation of the developer bearing member as viewed from the release pole; and a backflow prevention member that is a sheet-shaped member configured to be disposed along the entire length in the longitudinal direction of the developer bearing member so as to be upstream in the direction of rotation of the developer bearing member as viewed from the release pole, the backflow prevention member being disposed so that a proximal end portion thereof is fixed to an inside surface of the developing container, and a distal end portion thereof is in contact with or adjacent to the developer hearing member and facing downstream in the direction of rotation of the developer bearing member, wherein a notch is formed in the distal end portion of the backflow prevention member.