Patent ID: 7831170

Claim:
A toner cartridge installed in an image forming apparatus, the toner cartridge comprising: a toner storage container that has a toner discharge port; a toner discharge roller disposed inside of the toner storage container so as to block the toner discharge port; and a seal member, wherein an inner wall of the toner storage container faced by the toner discharge roller is provided with a curved region that has a curvature that matches a curvature of the toner discharge roller, an angle θ satisfies a relationship 20°≦θ≦180° in the curved region of the toner storage container, the angle θ being formed by a first imaginary line that connects a curvature start position of one side in a rotation direction of the toner discharge roller with a center of rotation of the toner discharge roller, and a second imaginary line that connects a curvature end position of other side in the rotation direction of the toner discharge roller with the center of rotation of the toner discharge roller, one end of the seal member is fixed to the inner wall of the toner storage container on a downstream side in the rotation direction of the toner discharge roller using the toner discharge port as a reference, and a free end side is inserted between the curved region and the toner discharge roller so as to cover the toner discharge port, the free end side of the seal member is separated from the toner discharge port by a rotation of the toner discharge roller, and the seal member is disposed in a state folded back in the inner wall of the toner storage container, and after the free end side of the seal member is evacuated from the toner discharge port by rotation of the toner discharge roller and released to the outside from between the inner wall of the toner storage container and the toner discharge roller, the seal member is in a state of being not folded back.