Abstract: A toner cartridge includes a container having a toner discharge opening formed therein, and an external member combined with the container so as to be relatively movable between a closed position at which the external member closes the toner discharge opening and an open position at which the external member uncovers the toner discharge opening. A compressible seal member extending along the peripheral edge of the toner discharge opening is disposed on the outer surface of the container. The seal member is compressed between the outer surface of the container and the inner surface of the external member. The seal member has a surface layer of cloth. A toner leakage preventing tape is stuck to a required site of the inner surface of the external member. The surface of the toner leakage preventing tape is non-adherent and has a coefficient of static friction .mu..sub.0, against the surface of a glazing, of 3.5 to 4.5, preferably 3.8 to 4.2.

Abstract: A toner cartridge comprising a container having a toner discharge port, a toner contained in the container and a stirrer for stirring the toner existing in the container. The stirrer includes a rotary shaft rotatably mounted between both side walls of the container, not less than four arms extending in the radial direction from the rotary shaft at fixed distances in the axial direction and not less than three paddles disposed among the ends of the arms. The paddles are arranged at not less than three angular positions having angles different from each other and spaced at a distance apart in the circumferential direction.

Abstract: A developing device includes a toner cartridge receiver, and a toner cartridge. The toner cartridge includes a container body having a toner discharge opening, and a shutter member mounted on the container body so as to be free to reciprocate between a closing position where it covers the toner discharge opening and an opening position where it is displaced from the toner discharge opening. By bringing the container body to the position of insertion, and then moving it to the position of mounting, the toner cartridge is detachably mounted on the toner cartridge receiver. The toner cartridge receiver is provided with a shutter member forwarding means and a shutter member returning means which, when the container body is brought to the position of insertion, are situated so as to face the shutter member, thereby inhibiting the movement of the shutter member.