Developing cartridge capable of reducing size of image forming apparatus

1. A developing cartridge comprising:

a developing roller rotatable about a rotational axis extending in a first direction, the developing roller including a roller shaft extending in the first direction and a roller body rotatable with the roller shaft;

a casing configured to accommodate developer therein;

a coupling rotatable about a first axis extending in the first direction, the coupling being positioned at one side of the casing in the first direction;

an electrode being electrically connected to the roller shaft, the electrode being positioned at the other side of the casing in the first direction; and

a storage medium including an electric contact surface, the electric contact surface being positioned at the one side of the casing in the first direction, the electrical contact surface being spaced apart from a first distal end of the roller body of the developing roller in the first direction.

2. The developing cartridge according to claim 1 ,

wherein the electrode is formed of electrically conductive resin.

3. The developing cartridge according to claim 1 ,

wherein the electrode is formed of electrically conductive metal.

4. The developing cartridge according to claim 1 ,

wherein the electrode includes a bearing through which the roller shaft is inserted.

5. The developing cartridge according to claim 1 , wherein the casing includes:

a first outer surface positioned at the one side of the casing in the first direction; and

a second outer surface positioned at the other side of the casing in the first direction.

6. The developing cartridge according to claim 5 ,

wherein the electric contact surface is positioned at the first outer surface.

7. The developing cartridge according to claim 5 ,

wherein the storage medium is positioned at the first outer surface.

8. The developing cartridge according to claim 5 ,

wherein the coupling is positioned at the first outer surface.

9. The developing cartridge according to claim 5 ,

wherein the electrode is positioned at the second outer surface.

10. The developing cartridge according to claim 1 ,

wherein the storage medium is positioned at the one side of the casing in the first direction.

11. The developing cartridge according to claim 1 , further comprising an agitator being rotatable according to rotation of the coupling.

12. The developing cartridge according to claim 11 ,

wherein the coupling includes a coupling gear, and

wherein the agitator includes an agitator gear, the agitator gear being positioned at the one side of the casing in the first direction, the agitator gear being rotatable according to rotation of the coupling gear.

13. The developing cartridge according to claim 12 ,

wherein the agitator includes a first shaft, and

wherein the agitator gear is mounted to the first shaft, the agitator gear being rotatable with the first shaft.

14. The developing cartridge according to claim 13 , further comprising an idle gear positioned at the one side of the casing in the first direction, the idle gear meshing with the coupling gear and the agitator gear.

15. The developing cartridge according to claim 1 , wherein the casing further includes:

a through-hole penetrating the other side of the casing in the first direction; and

a cap attached to the through-hole.

16. The developing cartridge according to claim 1 ,

wherein the coupling includes a recessed portion configured to receive driving force.

17. The developing cartridge according to claim 1 ,

wherein the storage medium stores information regarding the developing cartridge.

18. The developing cartridge according to claim 1 , further comprising a chip holder positioned at the one side of the casing in the first direction, and

wherein the electric contact surface is mounted to the chip holder.

19. The developing cartridge according to claim 18 ,

wherein the chip holder is movable relative to the casing.

20. The developing cartridge according to claim 19 ,

wherein the chip holder is movable relative to the casing in a second direction different from the first direction.

21. The developing cartridge according to claim 20 ,

wherein the second direction is perpendicular to the first direction.

22. The developing cartridge according to claim 1 ,

wherein the coupling is positioned between the developing roller and the electric contact surface in a second direction different from the first direction.

23. The developing cartridge according to claim 22 ,

wherein a first distance between the developing roller and the coupling in the second direction is greater than a second distance between the coupling and the electric contact surface in the second direction.

24. The developing cartridge according to claim 22 ,

wherein the second direction is perpendicular to the first direction.

25. The developing cartridge according to claim 1 ,

wherein the electrical contact surface is positioned farther from the electrode than the roller body of the developing roller is from the electrode in the first direction.

26. The developing cartridge according to claim 1 ,

wherein the developing cartridge is detachably attachable to a drum cartridge including a photosensitive drum.

27. The developing cartridge according to claim 1 ,

wherein the first distal end of the roller body of the developing roller is positioned farther from the electrode than a second distal end of the roller body of the developing roller is from the electrode in the first direction.