Developing agent replenishing apparatus and cartridge

摘要

A developing agent replenishing apparatus includes a developing agent receiving port for receiving a developing agent from a replenishment cartridge which stores developing agent when the cartridge is mounted and a conveyor for conveying the developing agent received in the receiving port to a developing device. The developer agent receiving port has a receiving opening and the replenishment cartridge has a replenishment opening. Cylindrical expandable covers are provided at the receiving and replenishment openings for opening or closing these openings.