DEVELOPING DEVICE AND IMAGE FORMING APPARATUS

摘要

A developing device comprises a first and a second developer conveyance path. A first conveyance member is provided in the first developer conveyance path in a freely rotatable manner and has a helical blade. A developing roller supplies the developer in the first developer conveyance path to a photoconductor drum. A developer collection path guides two-component developer left on a surface of the developing roller from the first developer conveyance path. A developer surface adjustment window comprises a predetermined level for allowing excess developer exceeding the level of the window to be guided from the first developer conveyance path to the developer collection path.