ORGANIC ELECTROLUMINESCENCE DISPLAY DEVICE

Abstract

Provided is an organic electroluminescence display device. The organic electroluminescence display device includes a bank that is provided so as to surround a central Portion of a Pixel electrode, an organic electroluminescence layer that is provided on the pixel electrode, a common electrode that is formed so as to extend from the organic electroluminescence layer to the bank, a color filter layer that overlaps the organic electro luminescence layer, a black matrix layer that overlaps the bank, a spacer that is provided on the black matrix layer, and a wiring that is provided on the black matrix layer so as to be placed on the spacer. The black matrix layer is disposed on the bank through the spacer. A convex Portion is formed by the wiring being placed on the spacer, and the convex portion is electrically connected to the common electrode above the bank.

Claims

1-12. (canceled)

13. An organic electroluminescence display device comprising: a plurality of pixels including a first pixel, a second pixel, a third pixel, and a fourth pixel, the first pixel including a first pixel electrode and a first thin film transistor, the first and second pixels arranged in a first direction, the third and fourth pixels arranged in a second direction which intersects the first direction, and the first to fourth pixels being adjacent to one another; a bank partitioning the plurality of pixels; a common electrode located above at least the first pixel electrode; an organic electroluminescence layer located at least between the first pixel electrode and the common electrode; and a plurality of spacers overlapping with the bank in a planar view, wherein the first pixel electrode is connected with the first thin film transistor via a first contact hole, the first pixel includes a first light emitting region, the second pixel includes a second light emitting region, the third pixel includes a third light emitting region, the fourth pixel includes a fourth light emitting region, the first contact hole and one of the spacers are located between the first and second light emitting regions, and the one of the spacers overlaps with an area surrounded by the first to fourth light emitting regions in a planar view.

14. The organic electroluminescence display device according to claim 13, wherein the common electrode, the bank, and the one of the spacers are stacked.

15. The organic electroluminescence display device according to claim 13, wherein the spacers are not located at all boundary areas between the pixels in a planar view.

16. The organic electroluminescence display device according to claim 13, wherein the first contact hole and the one of the spacers are arranged in the first direction.

17. The organic electroluminescence display device according to claim 13, wherein the first to fourth pixels are arranged in two columns and two rows.

18. The organic electroluminescence display device according to claim 13, wherein the first light emitting region has a first center portion therein, the second light emitting region has a second center portion therein, the third light emitting region has a third center portion therein, the fourth light emitting region has a fourth center portion therein, the one of the spacers are located in a region surrounded by imaginary lines which connect the first to fourth center portions in a planar view.

19. The organic electroluminescence display device according to claim 18, wherein the first light emitting region has a first corner, the second light emitting region has a second corner facing the first corner in the first direction, the third light emitting region has a third corner, the fourth light emitting region has a fourth corner facing the third corner in the second direction, the one of the spacers are located in a region surrounded by imaginary lines which connect the first to fourth corners in a planar view.

20. The organic electroluminescence display device according to claim 19, wherein the one of the spacers overlaps with a center of the region in a planar view.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a cross-sectional view of an organic electroluminescence display device according to an embodiment of the present invention.

[0021] FIG. 2 is a diagram illustrating a pixel electrode.

[0022] FIG. 3 is a diagram illustrating a black matrix layer.

DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0024] FIG. 1 is a plan view of an organic electroluminescence display device according to an embodiment of the present invention. The organic electroluminescence display device includes a first substrate 10 which has light transmittance and is formed of glass or the like. A semiconductor layer 12 is formed on the first substrate 10. A gate insulating film 14 is formed so as to cover the semiconductor layer 12. A gate electrode 16 is formed on the gate insulating film 14, and an interlayer insulating film 18 is formed so as to cover the gate electrode 16. A source electrode 20 and a drain electrode 22 are provided so as to pass through the interlayer insulating film 18 to reach the semiconductor layer 12. The semiconductor layer 12, the source electrode 20, the drain electrode 22, and the gate electrode 16 are components of a thin film transistor 24.

[0025] A passivation film 26 is formed on the interlayer insulating film 18 so as to cover the source electrode 20 and the drain electrode 22, and an insulating layer 28 is provided thereon. A light reflection layer 30 for reflecting light is formed on the insulating layer 28.

[0026] A pixel electrode 32 (for example, a positive electrode) is provided on the light reflection layer 30. The pixel electrode 32 passes through the insulating layer 28 to be electrically connected to one of the source electrode 20 and the drain electrode 22. The insulating layer 28 is present below the plurality of pixel electrodes 32, and the plurality of thin film transistors 24 are present below the insulating layer 28.

[0027] FIG. 2 is a diagram illustrating the pixel electrode 32. The organic electroluminescence display device has the plurality of pixel electrodes 32 which are separated from each other. Each of the pixel electrodes 32 is electrically connected to any one of the thin film transistors 24 by a contact 34 passing through the insulating layer 28. The contacts 34 included in the respective adjacent pixel electrodes 32 are disposed so as to be adjacent to each other. In other words, the plurality of contacts 34 are gathered in one place.

[0028] A bank 36 formed of an insulator such as a resin is provided so as to surround at least a central portion of each of the pixel electrodes 32. As illustrated in FIG. 1, an organic electroluminescence layer 38 is formed on the pixel electrodes 32 surrounded by the bank 36. A portion of the organic electroluminescence layer 38 is also placed on the bank 36. As illustrated in FIG. 2, the bank 36 has a coating portion 40 that continuously covers two or more adjacent contacts 34.

[0029] The organic electroluminescence layer 38 includes at least a light emitting layer, and further includes at least one of an electron transport layer, a hole transport layer, an electron injection layer, and a hole injection layer. At least one layer constituting the organic electroluminescence layer 38 is formed of an organic material. The organic electroluminescence layer 38 is formed by deposition or sputtering. The organic electroluminescence layer 38 is configured so as to emit white light through color mixture by superimposing a plurality of light emitting layers emitting different colors.

[0030] A common electrode 42 having light transmittance is formed so as to extend from the organic electroluminescence layer 38 to the bank 36. The common electrode 42 is formed so as to cover all the pixel electrodes 32. The organic electroluminescence layer 38 is disposed between the pixel electrode 32 and the common electrode 42. A voltage is applied to the pixel electrode 32 and the common electrode 42 to inject holes and electrons into the organic electroluminescence layer 38 from the pixel electrode and the common electrode, respectively. The injected holes and electrons are coupled to each other in the light emitting layer to emit light.

[0031] The organic electroluminescence display device includes a second substrate 44 which has light transmittance and is formed of glass or the like. The second substrate 44 is disposed so as to face the first substrate 10 at an interval. A color filter layer 46 is provided on a surface of the second substrate 44 on the first substrate 10 side. The color filter layer 46 overlaps the organic electroluminescence layer 38. A space 48 is formed between the organic electroluminescence layer 38 and the color filter layer 46. In other words, hollow sealing is applied. As a modified example, the space 48 may be filled with a resin. A black matrix layer 50 is formed on a surface of the second substrate 44 on the first substrate 10 side.

[0032] FIG. 3 is a diagram illustrating the black matrix layer 50. A spacer 52 is provided on the black matrix layer 50. A wiring 54 is provided on the black matrix layer 50 so as to be placed on the spacer 52. By the wiring 54 being placed on the spacer 52, a convex portion 56 is formed. Since the wiring 54 is formed on the black matrix layer 50 on the second substrate 44, a photo process or a baking process can be applied, and there is a wide range of choices for a material.

[0033] A manufacturing process includes forming the black matrix layer 50 on one surface of the second substrate 44, forming the black matrix layer 50 on the same surface, providing the spacer 52 on the black matrix layer 50 on the same side, and forming the wiring 54, in this order.

[0034] As illustrated in FIG. 1 and FIG. 2, the black matrix layer 50 overlaps the bank 36. The black matrix layer 50 is disposed on the bank 36 through the spacer 52. By the presence of the spacer 52, a gap is formed between the black matrix layer 50 and the bank 36, but the size of the gap is uniformized. In addition, by the presence of the spacer 52, the gap is increased in size in spite of the presence of external substances between the organic electroluminescence layer 38 and the color filter layer 46, and thus the organic electroluminescence layer 38 is not crushed.

[0035] The convex portion 56 of the wiring 54 is electrically connected to the common electrode 42 above the bank 36. By the presence of the convex portion 56, the wiring 54 and the common electrode 42 can stably come into contact with each other. As a modified example, when the space 48 illustrated in FIG. 1 is filled with a resin, even if an upper surface of the common electrode 42 is covered by the resin, the convex portion 56 is pushed into the resin to be brought into contact with the common electrode 42. The coating portion 40 of the bank 36 is large in width as the coating portion continuously covers two or more contacts 34, and thus the spacer 52 is located thereon. The convex portion 56 of the wiring 54 is electrically connected to the common electrode 42 above the coating portion 40.

[0036] According to this embodiment, the entire conductivity of the wiring 54 and the common electrode 42 that are electrically connected to each other is higher than the conductivity of the common electrode 42. In addition, since the wiring 54 is formed so as to overlap the black matrix layer 50 and not to protrude, the wiring does not interfere with light transmission. Therefore, it is possible to satisfy both high light transmittance and high conductivity.

[0037] While there have been described what are at present considered to be certain embodiments of the invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention.