Developing unit, image forming unit, and image forming apparatus

1. A developing unit comprising:

a body; and

a displacement member that is to be held by the body in a first mode in a first mounting state, and is to be held by the body displaceably between the first mode and a second mode in a reversible fashion in a second mounting state, the displacement member comprising a rotating member that is rotatable around a first rotation axis in both a first rotation direction and a second rotation direction, the second rotation direction being opposite to the first rotation direction, the first mode being a mode in which the displacement member rotates in the first rotation direction, and part or all of the displacement member is protruded from the body, and the first mounting state being a state in which a first toner cartridge is mounted on the developing unit, the first toner cartridge including a protrusion which limits rotation of the rotating member in the second rotation direction in the first mode, the second mounting state being a state in which a second toner cartridge is mounted on the developing unit.

2. The developing unit according to claim 1 , wherein the rotating member is in contact with the protrusion in the first mode.

3. The developing unit according to claim 1 , further comprising a biasing member that biases the rotating member in the first rotation direction.

4. The developing unit according to claim 1 , wherein

the developing unit is mountable on an image forming apparatus including a first attachment part and a second attachment part,

the displacement member is to be held by the image forming apparatus in the first mode in a first attachment state in which the developing unit is attached to the first attachment part of the image forming apparatus, and

the displacement member is to be held by the image forming apparatus in the second mode in a second attachment state in which the developing unit is attached to the second attachment part of the image forming apparatus.

5. An image forming apparatus comprising:

a first developing unit in accordance with claim 1 that allows a first toner cartridge to be mounted on the first developing unit detachably; and

a frame including a first attachment part that allows the first developing unit to be attached to the first attachment part detachably.

6. The image forming apparatus according to claim 5 , further comprising

a second developing unit that allows a second toner cartridge to be mounted on the second developing unit detachably,

the second developing unit including

a second body, and

a second displacement member that is to be held by the second body displaceably between a third mode and a fourth mode in a reversible fashion in a second mounting state, the second mounting state being a state in which the second toner cartridge is mounted on the second developing unit, wherein

the frame further includes a second attachment part that allows the second developing unit to be attached to the second attachment part detachably.

7. The image forming apparatus according to claim 6 , wherein the first developing unit and the second developing unit have respective structures that are substantially same with each other.

8. An image forming unit comprising:

a toner cartridge; and

a developing unit that allows the toner cartridge to be mounted on the developing unit detachably,

the developing unit including

a body, and

a displacement member that is to be held by the body in a first mode in a first mounting state, and is to be held by the body displaceably between the first mode and a second mode in a reversible fashion in a second mounting state, the displacement member comprising a rotating member that is rotatable around a first rotation axis in both a first rotation direction and a second rotation direction, the second rotation direction being opposite to the first rotation direction, the first mode being a mode in which the displacement member rotates in the first rotation direction, and part or all of the displacement member is protruded from the body, and the first mounting state being a state in which a first toner cartridge is mounted on the developing unit, the first toner cartridge including a protrusion which limits rotation of the rotating member in the second rotation direction in the first mode, the second mounting state being a state in which a second toner cartridge is mounted on the developing unit.

9. The image forming unit according to claim 8 , wherein the rotating member is in contact with the protrusion in the first mode.

10. The image forming unit according to claim 8 , further comprising a biasing member that biases the rotating member in the first rotation direction.

11. An image forming apparatus comprising:

a first toner cartridge containing a first toner;

a second toner cartridge containing a second toner;

a developing unit to which both the first toner cartridge and the second toner cartridge are attachable, and that allows one of the first toner cartridge and the second toner cartridge to be attached to the developing unit;

an attachment part to which the developing unit is to be attached; and

a displacement member displaceable between a first mode and a second mode, the first mode allowing the developing unit, to which the first toner cartridge is attached, to be attached to the attachment part, the second mode preventing the developing unit, to which the second toner cartridge is attached, from being attached to the attachment part.

12. The image forming apparatus according to claim 11 , wherein

the displacement member allows the first toner cartridge to be attached to the developing unit that is attached to the attachment part, and

the displacement member prevents the second toner cartridge from being attached to the developing unit that is attached to the attachment part.

13. The image forming apparatus according to claim 11 , wherein the attachment part accepts attaching of the developing unit to which the first toner cartridge is attached, or attaching of the developing unit to which neither of the first and the second toner cartridges is attached.

14. The image forming apparatus according to claim 11 , wherein the displacement member is held by the developing unit.