Patent ID: 7672621

Claim:
A developing device to which a toner cartridge is to be attached, the developing device comprising: a developing roller comprising a rotational axis extending along a horizontal direction, the developing roller being capable of supporting a toner; a casing comprising a developing chamber for accommodating the toner to be supported by the developing roller, a feed opening for feeding the toner from the toner cartridge to the developing chamber, and a return opening for returning the toner from the developing chamber to the toner cartridge, wherein the developing chamber is defined by the developing roller; and a transporting member located within the developing chamber, wherein the transporting member transports the toner within the developing chamber from the feed opening to the return opening, wherein the feed opening and the return opening are offset along the horizontal direction, and the feed opening is located higher than the return opening, and the developing device is configured to accept the toner cartridge in a detachable manner.