Electron emission device, backlight unit (BLU) including the electron emission device, flat display apparatus including the BLU, and method of driving the electron emission device

Abstract

An electron emission device effectively blocks an electric field generated by an anode, consistently and stably emits electrons at a low gate voltage, and provides a high luminous uniformity and luminous efficiency. In addition, a flat display apparatus using the electron emission device as a backlight unit (BLU) and a method of driving the light emission device are provided. The electron emission device includes: a base substrate; a first electrode including a first main electrode portion arranged on a surface of the base substrate and extending in a predetermined direction and a first auxiliary electrode extending from the first main electrode portion; a second electrode including a second main electrode portion arranged on the surface of the base substrate and separated from the first electrode and extending in a predetermined direction and a second auxiliary electrode extending from the second main electrode portion; and an electron emission source arranged on at least one of the first and second electrodes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention and many of the attendant advantages thereof, will be readily apparent as the present invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:

FIG. 1 is a cross-sectional view of a conventional Field Emitter Array (FEA) electron emission device;

FIG. 2 is a perspective view of an electron emission device according to a first embodiment of the present invention;

FIG. 3 is a plan view of the electron emission device of FIG. 2;

FIG. 4 is a perspective view of an electron emission device according to a second embodiment of the present invention;

FIG. 5 is a plan view of the electron emission device of FIG. 4;

FIGS. 6 through 15 are views of modified versions of the electron emission device of FIG. 3 or FIG. 4;

FIG. 16 is a timing diagram relating to a method of driving an electron emission device according to an embodiment of the present invention;

FIG. 17 is an exploded perspective view of a flat display apparatus including a backlight unit (BLU) having the electron emission device of FIG. 2 according to an embodiment of the present invention;

FIG. 18 is a plan view of a rear panel of the BLU of FIG. 17 according to an embodiment of the present invention;

FIG. 19 is a plan view of a rear panel according to another embodiment of the present invention; and

FIG. 20 is a cross-sectional view of the flat display apparatus taken along line VIII-VIII of FIG. 17.

Claims

1. An electron emission device comprising: a base substrate;a first electrode including a first main electrode portion arranged on a surface of the base substrate and extending in a predetermined direction and a first auxiliary electrode extending from the first main electrode portion;a second electrode including a second main electrode portion arranged on the surface of the base substrate and separated from the first electrode and extending in a predetermined direction and a second auxiliary electrode extending from the second main electrode portion; andan electron emission source arranged on at least one of the first and second electrodes.

2. The electron emission device of claim 1, wherein the first and second auxiliary electrodes are respectively arranged on at least a portion of the first and second electrodes and block an external electric field from affecting an electric field between the first and second electrodes.

3. The electron emission device of claim 2, wherein the first and second auxiliary electrodes are respectively arranged on all of the first and second electrodes.

4. The electron emission device of claim 2, wherein the first and second auxiliary electrodes are thicker than the first and second electrodes.

5. The electron emission device of claim 2, further comprising an insulating layer interposed between the first and second auxiliary electrodes and portions of the first and second electrodes on which the first and second auxiliary electrodes are respectively arranged.

6. The electron emission device of claim 1, wherein a constant distance is maintained between the first and second auxiliary electrodes.

7. The electron emission device of claim 1, wherein the first and second auxiliary electrodes each have a spiral pattern in which a radius of curvature of the first and second auxiliary electrodes are gradually reduced.

8. The electron emission device of claim 1, wherein the first and second auxiliary electrodes each have a bent pattern in which lengths of sides of each of the first and second auxiliary electrodes are gradually reduced.

9. The electron emission device of claim 8, wherein the first and second auxiliary electrodes each have a right-angled pattern in which adjacent sides of each of the first and second auxiliary electrodes are perpendicular to each other.

10. The electron emission device of claim 1, wherein a shortest distance between the first main electrode portion and the second auxiliary electrode is equal to a distance between the first and second auxiliary electrodes.

11. The electron emission device of claim 1, wherein a shortest distance between the second main electrode portion and the first auxiliary electrode is equal to a distance between the first and second auxiliary electrodes.

12. The electron emission device of claim 1, wherein the electron emission source is disposed on only a portion of either the first or second electrodes.

13. The electron emission device of claim 1, wherein the first and second electrodes have surfaces facing each other and wherein the electron emission source is disposed on one of the surfaces of the first and second electrodes facing each other.

14. The electron emission device of claim 1, wherein a distance between either an end of the electron emission source on one of the first and second electrodes and the other of the first and second electrodes or another electron emission source which faces and is separated from the electron emission source is in a range of 1.0 nm to 0.01 μm.

15. The electron emission device of claim 1, wherein a portion of the base substrate occupied by the electron emission source is in a range of 0.0001 to 50.0% of a portion of the base substrate occupied by the first and second electrodes and a space between the first and second electrodes.

16. A backlight unit (BLU) comprising: a base substrate;a plurality of first electrodes, each including: a first main electrode portion arranged on a surface of the base substrate and extending in a predetermined direction and a first auxiliary electrode extending from the first main electrode portion;a plurality of second electrodes corresponding to the first electrodes, each of the second electrodes including: a second main electrode portion arranged on the surface of the base substrate and separated from the corresponding first electrode and extending in a predetermined direction and a second auxiliary electrode extending from the second main electrode portion;an electron emission source arranged on at least one of the first and second electrodes; anda phosphor layer arranged in front of the base substrate, the phosphor layer excited by electrons emitted from the electron emission source in response to an electric field between the first and second electrodes to generate visible light.

17. The BLU of claim 16, wherein the first main electrode portions and the second main electrode portions are arranged alternately and parallel to each other on the base substrate, the first auxiliary electrodes extend from one side of each of the first main electrode portions, and the second auxiliary electrodes extend from one side of each of the second main electrode portions.

18. The BLU of claim 16, wherein the first main electrode portions and the second main electrode portions are arranged alternately and parallel to each other on the base substrate, the first auxiliary electrodes extend from both sides of the first main electrode portions, and the second auxiliary electrodes extend from both sides of the first main electrode portions.

19. The BLU of claim 16, further comprising: a front substrate arranged parallel to the base substrate; andan anode arranged behind the front substrate to accelerate electrons emitted from the electron emission source toward the phosphor layer.

20. The BLU of claim 16, wherein the first and second auxiliary electrodes are respectively arranged on at least a portion of the first and second electrodes to block an external electric field from affecting an electric field between the first and second electrodes.

21. The BLU of claim 20, wherein the first and second auxiliary electrodes are respectively arranged on all of the first and second electrodes.

22. The BLU of claim 20, wherein the first and second auxiliary electrodes are thicker than first and second electrodes.

23. The BLU of claim 20, further comprising an insulating layer interposed between the first and second auxiliary electrodes and portions of the first and second electrodes on which the first and second auxiliary electrodes are respectively arranged.

24. The BLU of claim 16, wherein a constant distance is maintained between the first and second auxiliary electrodes.

25. The BLU of claim 16, wherein the first and second auxiliary electrodes each have a spiral pattern in which a radius of curvature of the first and second auxiliary electrodes are gradually reduced.

26. The BLU of claim 16, wherein the first and second auxiliary electrodes form a bent pattern in which lengths of sides of each of the first and second auxiliary electrodes are gradually reduced.

27. The BLU of claim 26, wherein the first and second auxiliary electrodes form a right-angled pattern in which adjacent sides of each of the first and second auxiliary electrodes are perpendicular to each other.

28. The BLU of claim 16, wherein a shortest distance between the first main electrode portions and the second auxiliary electrodes is equal to a distance between the first and second auxiliary electrodes.

29. The BLU of claim 16, wherein a shortest distance between the second main electrode portions and the first auxiliary electrodes is equal to a distance between the first and second auxiliary electrodes.

30. The BLU of claim 16, wherein the electron emission source is disposed on only a portion of the first or second electrodes.

31. The BLU of claim 16, wherein the electron emission source is disposed on one of surfaces of the first and second electrodes facing each other.

32. The BLU of claim 16, wherein a distance between either an end of the electron emission source on one of the first and second electrodes and the other of the first and second electrodes or another electron emission source which faces and is separated from the electron emission source is in a range of 1.0 nm to 0.01 μm.

33. The BLU of claim 16, wherein a portion of the base substrate occupied by the electron emission source is in a range of 0.0001 to 50.0% of a portion of the base substrate occupied by the first and second electrodes and a space between the first and second electrodes.

34. A flat display apparatus comprising: a backlight unit (BLU) including: a base substrate;a plurality of first electrodes, each including: a first main electrode portion arranged on a surface of the base substrate and extending in a predetermined direction and a first auxiliary electrode extending from the first main electrode portion;a plurality of second electrodes corresponding to the first electrodes, each of the second electrodes including: a second main electrode portion arranged on the surface of the base substrate and separated from the corresponding first electrode and extending in a predetermined direction and a second auxiliary electrode extending from the second main electrode portion;an electron emission source arranged on at least one of the first and second electrodes; anda phosphor layer arranged in front of the base substrate, the phosphor layer excited by electrons emitted from the electron emission source in response to an electric field between the first and second electrodes to generate visible light; anda display panel including a light receiving/generating device arranged in front of the BLU and displaying an image by controlling light supplied from the BLU.

35. The apparatus of claim 34, wherein the light receiving/generating device comprises a liquid crystal device.

36. A method of driving an electron emission device including a first electrode, a second electrode separated from the first electrode, and an electron emission source arranged on the first and second electrodes, the method comprising: alternately supplying positive and negative voltages to the first and second electrodes by: supplying the negative voltage to one of the first and second electrodes for a predetermined period of time while supplying the positive voltage to the other of the first and second electrodes for the predetermined period of time; andsupplying the positive voltage to the one of the first and second electrodes for a predetermined period of time while supplying the negative voltage to the other of the first and second electrodes;wherein the first and second electrodes alternately function as a cathode of the electron emission device.