Patent ID: 7742726

Claim:
A developer cartridge comprising: a cartridge cabinet comprising: a wall surface; a developer accommodate chamber that accommodates developer; a supply opening that is provided in the wall surface and supplies the developer from an inside of the developer accommodate chamber to an outside of the developer accommodate chamber; and a return opening that is provided in the wall surface and returns the developer from the outside of the developer accommodate chamber to the inside of the developer accommodate chamber, wherein the developer cartridge further comprises: a rotational shaft that is rotatably supported in the cartridge cabinet, extends parallel to the wall surface and penetrates through the inside of the developer accommodate chamber; a first agitating blade that is attached to the rotational shaft to rotate with the rotational shaft and that is located in a position opposed to the return opening, a distance from the rotational shaft to a distal end of the first agitating blade being shorter than a distance from the rotational shaft to the return opening in a region overlapping the return opening; and a second agitating blade that is attached to the rotational shaft to rotate with the rotational shaft and that is located in a position opposed to the supply opening, a distance from the rotational shaft to a distal end of the second agitating blade being longer than a distance from the rotational shaft to the supply opening.