Apparatus for detecting developer level in developing unit

Abstract

An apparatus to detect the remaining amount of developer in a developing unit is provided. The apparatus includes a light emitting prism and a light receiving prism placed opposite to each other in a developer store space of the developing unit and forming a light emitting path and a light receiving path, respectively. A light emitting element irradiates light through the light emitting prism, and a light receiving element receives a light signal through the light receiving prism. An antistatic agent is coated on a light emitting window of the light emitting prism and a light receiving window of the light receiving prism, respectively, to substantially prevent developer from attaching on the light emitting window and the light receiving window. Because the developer is not stuck on the light receiving window and the light emitting window to which the light signal is transmitted, an accurate light signal may be transmitted from the light emitting window to the light receiving window, thereby substantially preventing printing defects caused by detection errors from occurring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings, in which:

FIG. 1 is a perspective view of a developing unit having an apparatus to detect developer level according to an exemplary embodiment of the present invention;

FIG. 2 is an elevational view of a coating layer disposed on a light receiving window and a light emitting window of the developing unit of FIG. 1;

FIG. 3 is a perspective view of a cleaning tool for the light receiving window and the light emitting window of the developing unit of FIG. 1;

FIG. 4 is a graph showing a sensing level of developer using the developing unit of FIG. 1; and

FIG. 5 is an elevational view of an image forming apparatus including a developing unit according to an exemplary embodiment of the present invention.

Claims

1. An apparatus to detect developer level in a developer store space of a developing unit, the apparatus comprising: a light emitting element to irradiate light into the developer store space;a light receiving element to receive light from the light emitting element through the developer store space; andan antistatic agent coated on a window connected to the light emitting element and a window connected to the light receiving element, respectively, to substantially prevent developer from attaching to the light emitting element and/or the window connected to the light receiving element.

2. The apparatus of claim 1, further comprising a light emitting prism and a light receiving prism installed in the developer store space forming a light emitting path and a light receiving path, respectively; wherein the window connected to the light emitting element and the window connected to the light receiving element belong to the light emitting prism and the light receiving prism, respectively.

3. The apparatus of claim 1, wherein the antistatic agent is polythiophene-based pigments diluted in distilled water or isopropyl alcohol.

4. The apparatus of claim 1, wherein a surface resistance of the antistatic agent is less than approximately 105 ohm/mm2.

5. The apparatus of claim 1, wherein a coating thickness of the antistatic agent is less than approximately 5.0 μm.

6. The apparatus of claim 1, wherein a remaining amount of developer is determined according to a range of an amount of received light detected by the light receiving element.

7. The apparatus of claim 1, further comprising a cleaning tool to clean the light emitting window and the light receiving window.

8. The apparatus of claim 7, Wherein the cleaning tool comprises a cleaning blade connected to a rotating member to contact the light emitting window and the light receiving window, respectively, to clean the light emitting window and the light receiving window according to the rotation of the rotating member.

9. The apparatus of claim 8, wherein the rotating member is an auger rotating in a developer store space and conveying the developer in a predetermined direction.

10. The apparatus of claim 8, wherein the cleaning blade is made of rubber.

11. The apparatus of claim 1, wherein a developer supplying member is connected to a body of the developing unit to supply developer to the developer store space.

12. An apparatus to detect developer level in a developer store space of a developing unit, the apparatus comprising: a body having a developer store space adapted to receive developer;a light emitting element to irradiate light into the developer store space;a light receiving element to receive light from the light emitting element through the developer store space; andan antistatic agent coated on a window connected to the light emitting element and a window connected to the light receiving element, respectively, to substantially prevent developer from attaching to the window connected to the light emitting element and/or the window connected to the light receiving element.

13. The apparatus of claim 12, further comprising a light emitting prism and a light receiving prism installed in the developer store space forming a light emitting path and a light receiving path, respectively; wherein the window connected to the light emitting element and the window connected to the light receiving element belong to the light emitting prism and the light receiving prism, respectively.

14. The apparatus of claim 12, wherein the antistatic agent is polythiophene-based pigments diluted in distilled water or isopropyl alcohol.

15. The apparatus of claim 12, wherein a surface resistance of the antistatic agent is less than approximately 105 ohm/mm2.

16. The apparatus of claim 12, wherein a coating thickness of the antistatic agent is less than approximately 5.0 μm.

17. The apparatus of claim 12, wherein a remaining amount of developer is determined according to a range of an amount of emitted light detected by the light receiving element.

18. The apparatus of claim 12, further comprising a cleaning tool to clean the light emitting and the light receiving windows.

19. The apparatus of claim 18, wherein the cleaning tool comprises a cleaning blade connected to a rotating member to contact the light emitting and light receiving windows to clean the light emitting and light receiving windows according to the rotation of the rotating member.

20. The apparatus of claim 19, wherein the rotating member is an auger rotating in the developer store space and conveying the developer in a predetermined direction.

21. The apparatus of claim 19, wherein the cleaning blade is made of rubber.

22. The apparatus of claim 12, wherein a developer supplying member is connected to the body of the developing unit to supply developer to the developer store space.

23. An image forming apparatus, comprising: a photosensitive body;a developing unit to supply developer to the photosensitive body, the developing unit including a body having a developer store space adapted to receive developer;a light emitting element to irradiate light into the developer store space;a light receiving element to receive light from the light emitting element through the developer store space; andan antistatic agent coated on a window connected to the light emitting element and a window connected to the light receiving element, respectively, to substantially prevent developer from attaching to the window connected to the light emitting element and/or the window connected to the light receiving element.

24. The apparatus of claim 23, further comprising a light emitting prism and a light receiving prism installed in the developer store space forming a light emitting path and a light receiving path, respectively; wherein the window connected to the light emitting element and the window connected to the light receiving element belong to the light emitting prism and the light receiving prism, respectively.

25. The apparatus of claim 23, wherein the antistatic agent is polythiophene-based pigments diluted in distilled water or isopropyl alcohol.

26. The apparatus of claim 23, wherein a surface resistance of the antistatic agent is less than approximately 105 ohm/mm2.

27. The apparatus of claim 23, wherein a coating thickness of the antistatic agent is less than approximately 5.0 μm.

28. The apparatus of claim 23, wherein a remaining amount of developer is determined according to a range of an amount of emitted light detected by the light receiving element.

29. The apparatus of claim 23, further comprising a cleaning tool to clean the light emitting and the light receiving windows.

30. The apparatus of claim 29, wherein the cleaning tool comprises a cleaning blade connected to a rotating member to contact the light emitting and light receiving windows to clean the light emitting and light receiving windows according to the rotation of the rotating member.

31. The apparatus of claim 30, wherein the rotating member is an auger rotating in the developer store space and conveying the developer in a predetermined direction.

32. The apparatus of claim 30, wherein the cleaning blade is made of rubber.

33. The apparatus of claim 23, wherein a developer supplying member is connected to the body of the developing unit to supply developer to the developer store space.