Display apparatus using electroluminescence elements

• US 6,114,715 A
• Filed: 11/28/1997
• Issued: 09/05/2000
• Est. Priority Date: 11/29/1996
• Status: Expired due to Term

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Hamada, Hiroki
• Primary Examiner(s): Hardy, David
• Assistant Examiner(s): Wilson, Allan R.
• Application Number:
  US08/969,363
• Time in Patent Office: 1,012 Days
• Field of Search: 257/59, 257/72, 257/98, 257/94, 257/88, 257/90, 257/93
• US Class Current: 257/72
• CPC Class Codes: H10K 50/865 comprising light absorbing layers, e.g. light-blocking layers
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/126 Shielding, e.g. light-blocking means over the TFTs
• CPC Class Codes: H10K 59/17 Passive-matrix OLED displays

Abstract

A display apparatus using electroluminescence elements has a substrate, a plurality of anodes arranged generally parallel to each other on a surface of the substrate, and the EL element disposed on the substrate and the anodes. In addition, a material layer is located on the substrate and between the anodes. The material layer may be either a black matrix layer constructed of a light shielding film or a highly reflective multilayer film which suppresses optical crosstalk caused by light scattering originated in the EL element. The material layer covers the anodes such that only a part of each anode corresponding to a display area is exposed. The display apparatus may be used in either a simple matrix display system or an active matrix display system.

Claims

1. An electroluminescent display apparatus comprising:

a light emitting element layer having first and second surfaces, wherein the light emitting element layer includes a light emitting layer, a hole transporting layer and an electron transporting layer;

a plurality of first electrodes arranged, generally parallel to one another, over the first surface of the light emitting element layer;

a plurality of second electrodes arranged, generally parallel to one another and crossing the first electrodes, over the second surface of the light emitting element layer, with electroluminescence elements formed at individual crossings of the first electrodes and the second electrodes; and

a black-matrix layer having an insulation property, arranged adjacent to at least one of the first and second surfaces between the first electrodes so as to expose at least the electroluminescence elements.

2. The electroluminescent display apparatus according to claim 1, further comprising driving elements, provided above at least one of the first and second surfaces, for driving the associated electroluminescence elements.

3. The electroluminescent display apparatus according to claim 2, wherein the driving elements are thin film transistors.

4. The electroluminescent display apparatus according to claim 1, wherein the light emitting element layer is formed of an organic compound.

29. The electroluminescent display apparatus of claim 1 wherein the light emitting element layer internally generates light.

30. The electroluminescent display apparatus of claim 1 wherein the light emitting element layer is configurable to generate light of multiple colors.

31. The electroluminescent display apparatus of claim 1 wherein the electroluminescence element internally generates light.

32. The electroluminescent display apparatus of claim 1 wherein the electroluminescence element is configurable to generate light of multiple colors.

33. The electroluminescent display apparatus of claim 1 wherein:

the black-matrix layer is substantially opaque, and

the first electrodes are at least partially translucent.

34. The electroluminescent display apparatus of claim 1 wherein the black-matrix layer is substantially coplanar with the first electrodes.

35. The electroluminescent display apparatus of claim 1 wherein:

the first electrodes have a thickness, and

the black-matrix layer is coextensive with the thickness of the first electrodes.

38. The electroluminescent display apparatus according to claim 1 wherein said black-matrix layer having an insulation property is located between said second surface of said light emitting element layer and said plurality of second electrodes.

5. An electroluminescent display apparatus comprising:

a transparent insulator substrate;

a plurality of first electrodes arranged, generally parallel to one another, on a surface of the transparent insulator substrate;

a black-matrix layer having an insulation property and a light-shielding property, arranged on the surface of the transparent insulator substrate between the first electrodes;

a light emitting element layer having first and second surfaces and provided above the first electrodes and the black-matrix layer, wherein the light emitting element layer includes a light emitting layer, a hole transporting layer and an electron transporting layer; and

a plurality of second electrodes arranged, in parallel to one another and crossing the first electrodes, over the light emitting element layer, with electroluminescence elements formed at individual crossings of the first electrodes and the second electrodes.

6. The electroluminescent display apparatus according to claim 5, further comprising driving elements, provided above at least one of the first and second surfaces, for driving the associated electroluminescence elements.

7. The electroluminescent display apparatus according to claim 6, wherein the driving elements are thin film transistors.

8. The electroluminescent display apparatus according to claim 5, wherein the light emitting element layer is formed of an organic compound.

9. An electroluminescent display apparatus comprising:

a transparent insulator substrate;

a plurality of first electrodes arranged, generally parallel to one another, on a surface of the transparent insulator substrate;

an insulator film provided on the surface of the transparent insulator substrate between the first electrodes and on side walls of the first electrodes;

a black-matrix layer having a light-shielding property, located on the insulator film;

a light emitting element layer having first and second surfaces, provided above the first electrodes and the black-matrix layer, wherein the light emitting element layer includes a light emitting layer, a hole transporting layer and an electron transporting layer; and

a plurality of second electrodes arranged, generally parallel to one another and crossing the first electrodes, over the light emitting element layer, with electroluminescence elements formed at individual crossings of the first electrodes and the second electrodes.

10. The electroluminescent display apparatus according to claim 9, further comprising driving elements, provided above at least one of the first and second surfaces, for driving the associated electroluminescence elements.

11. The electroluminescent display apparatus according to claim 10, wherein the driving elements are thin film transistors.

12. The electroluminescent display apparatus according to claim 9, wherein the light emitting element layer is formed of an organic compound.

36. The electroluminescent display apparatus of claim 9 wherein the black-matrix layer is an insulating material.

13. An electroluminescent display apparatus comprising:

a transparent insulator substrate;

a plurality of first electrodes arranged, generally parallel to one another, on a surface of the transparent insulator substrate;

a high-reflection multilayer film located on the surface of the transparent insulator substrate between the first electrodes;

a light emitting element layer having first and second surfaces, provided above the first electrodes and the high-reflection multilayer film, wherein the light emitting element layer includes a light emitting layer, a hole transporting layer and an electron transporting layer; and

a plurality of second electrodes arranged, generally parallel to one another and crossing the first electrodes, over the light emitting element layer, with electroluminescence elements formed at individual crossings of the first electrodes and the second electrodes.

14. The electroluminescent display apparatus according to claim 13, wherein the high-reflection multilayer film comprises at least two layers.

15. The electroluminescent display apparatus according to claim 13, wherein the high-reflection multilayer film includes a silicon oxide film provided on the surface of the transparent insulator substrate between the first electrodes and an amorphous silicon film provided on the silicon oxide film.

16. The electroluminescent display apparatus according to claim 15, wherein thicknesses of the silicon oxide film and the amorphous silicon film are set in accordance with a peak wavelength of the light emitting element layer.

17. The electroluminescent display apparatus according to claim 13, further comprising driving elements, provided above at least one of the first and second surfaces, for driving the associated electroluminescence elements.

18. The electroluminescent display apparatus according to claim 17, wherein the driving elements are thin film transistors.

19. The electroluminescent display apparatus according to claim 13, wherein the light emitting element layer is formed of an organic compound.

37. The electroluminescent display apparatus of claim 13 wherein the high-reflection multilayer film consists of a semiconductor material.

20. A pixel for an active matrix display apparatus, the pixel comprising:

a transparent insulator substrate;

an element for driving a pixel disposed on a first surface of the transparent insulator substrate, the element for driving a pixel including a source electrode and a drain electrode;

an interlayer insulator film disposed on the transparent insulator substrate and covering the driving element;

a flattening insulator film formed on the source and drain electrodes and the interlayer insulator film;

an anode formed on the flattening insulator film;

a black matrix layer disposed on the flattening insulator film adjacent to the anode; and

an organic electroluminescence (EL) element formed on the anode, wherein the element includes a light emitting layer, a hole transporting layer and an electron transporting layer.

21. The pixel of claim 20 wherein the element for driving a pixel comprises a thin film transistor (TFT).

22. The pixel of claim 21 wherein the TFT comprises a planar type transistor with a lightly doped drain (LDD) structure.

23. The pixel of claim 21 wherein an active layer of the TFT comprises a polycrystalline silicon film.

24. The pixel of claim 23 wherein the black matrix layer covers a top of the polycrystalline silicon film.

25. The pixel of claim 23 wherein light emitted by the light emitting layer of the EL element is blocked by the black matrix layer, such that the light is not irradiated on the polycrystalline silicon film.

26. The pixel of claim 21 wherein the TFT comprises:

a polycrystalline silicon film formed on the transparent insulator substrate;

a gate insulator film formed on the polycrystalline silicon film; and

a gate electrode formed on the gate insulator film.

27. The pixel of claim 26 wherein the polycrystalline silicon film includes:

a high concentration drain region;

a low concentration drain region;

a high concentration source region; and

a low concentration source region.

28. The pixel of claim 20 wherein the black matrix layer comprises a high-reflection multilayer film.

39. The pixel of claim 20, wherein said black-matrix layer disposed on the flattening insulator film adjacent to the anode is disposed between the flattening insulator film and said light emitting layer.