Toner cartridge, adaptor for toner cartridge, toner cartridge assembly and image forming apparatus

1. A toner cartridge comprising:

a cartridge main body defining a container having first and second opposed end walls and a tubular barrel extending between the end walls, the container being at least partly filled with a developer, a discharging orifice for discharging the developer being provided in the first end wall, and at least one protrusion provided to the first end wall and protruding toward the second end wall,

wherein the barrel has at least in part a portion whose outer shape of a cross section orthogonal to a direction of a tube center line is a shape of a curve of constant width other than a circle.

2. The toner cartridge according to claim 1 , wherein:

the shape of the curve of constant width is a shape of a Reuleaux polygon.

3. The toner cartridge according to claim 1 , wherein:

the developer discharging orifice is provided at a position of a center of gravity of the curve of constant width of the one of the pair of end walls.

4. The toner cartridge according to claim 3 , further comprising:

a shutter mechanism that opens and closes the developer discharging orifice,

wherein the shutter mechanism includes a shutter plate that closes the developer discharging orifice from inside the cartridge main body in a re-openable manner and a biasing member that biases the shutter plate toward the developer discharging orifice.

5. The toner cartridge according to claim 1 , wherein:

a rib for developer transportation is provided on an inner peripheral surface of the barrel so as to protrude inward.

6. The toner cartridge according to claim 1 , wherein:

the outer shape of the cross-section of the barrel orthogonal to the tube center line is a triangle.

7. An image forming apparatus, characterized by comprising:

an apparatus main body of a box shape in which various image forming devices are provided;

a toner cartridge, which is attached detachably to the apparatus main body, wherein the toner cartridge includes a cartridge main body as a container having a tubular barrel and filled with a developer, wherein the barrel has at least in part a portion whose outer shape of a cross section orthogonal to a direction of a tube center line is a shape of a curve of constant width other than a circle;

an accommodation portion including an inner surface with which an outer peripheral surface of the barrel of the toner cartridge comes into sliding contact and an opening provided to one end face through which the toner cartridge is attached and detached and having a cross section in a direction orthogonal to a direction of a tube center line in a shape of a regular tetragon;

a rotation mechanism configured to rotate the toner cartridge attached to the accommodation portion in a circumferential direction; and

a transportation mechanism configured to transport the developer inside the toner cartridge to image forming components provided inside the apparatus main body through a developer discharging orifice provided to the toner cartridge.

8. The image forming apparatus according to claim 7 , wherein:

the accommodation portion is provided with a notch window notched so as to traverse a wall surface that defines the accommodation portion; and

the rotation mechanism includes,

a drive belt that circulates while abutting on an outer peripheral surface of the toner cartridge in a state where the drive belt fits into the accommodation portion from the notch window,

a drive roller and a driven roller over which the drive belt is looped, and

a drive motor that drives the drive roller to rotate.

9. The image forming apparatus according to claim 7 , wherein:

a developer discharging orifice is provided about a position of a center of gravity of the barrel in the end wall of the toner cartridge;

the transportation mechanism includes,

a developer receiving and discharging pipe that is inserted relatively into the developer discharging orifice in a state where the toner cartridge is attached inside the accommodation portion and forces the developer discharging orifice to open by activating a shutter mechanism, and

a spiral feeder that is internally attached to the developer receiving and discharging pipe and receives and discharges the developer inside the toner cartridge; and

the spiral feeder rotates on its axis about a center of its shaft while revolving about a tube center of the cartridge accommodation portion in response to a circulation of the developer discharging orifice caused by a rotation of the toner cartridge in a state where the developer receiving and discharging pipe is inserted into the developer discharging orifice.

10. An image forming apparatus, characterized by comprising:

an apparatus main body of a box shape in which various image forming devices are provided;

a toner cartridge, which is attached detachably to the apparatus main body, wherein the toner cartridge includes a cartridge main body as a container having a tubular barrel and filled with a developer, wherein the barrel has at least in part a portion whose outer shape of a cross section orthogonal to a direction of a tube center line is a shape of a curve of Reuleaux polygon;

an accommodation portion including an inner surface with which an outer peripheral surface of the barrel of the toner cartridge comes into sliding contact and an opening provided to one end face through which the toner cartridge is attached and detached and having a cross section in a direction orthogonal to a direction of a tube center line in a shape of a regular polygon;

a rotation mechanism configured to rotate the toner cartridge attached to the accommodation portion in a circumferential direction; and

a transportation mechanism configured to transport the developer inside the toner cartridge to image forming components provided inside the apparatus main body through a developer discharging orifice provided to the toner cartridge, wherein:

the regular polygon is a 2n (where n is a natural number equal to 3 or larger) polygon; and

a shape of the Reuleaux polygon of the toner cartridge is almost a Reuleaux (2n−1) polygon.