Electroluminescence display device

• US 6,492,778 B1
• Filed: 03/09/2000
• Issued: 12/10/2002
• Est. Priority Date: 03/11/1999
• Status: Expired due to Term

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Segawa, Yasuo
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Vu, Jimmy T.
• Application Number:
  US09/521,747
• Time in Patent Office: 1,006 Days
• Field of Search: 315/169.1, 315/169.3, 313/309, 313/129, 313/137, 313/504, 437/86
• US Class Current: 315/169.3
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/875 Arrangements for extracting light from the devices

Abstract

In an organic EL display device including a TFT (40) and an organic EL element (60) formed on an insulating substrate (10) of a glass substrate, insulating films, namely, a planarization insulating film (17), an interlayer insulating film (15), and a gate insulating film (12), for forming the TFT (40) are not provided at a region for forming the organic EL element (60). Instead, an opening (65) formed by removing these insulating films is provided to expose the glass substrate (10), and at this exposed region an anode (61), an emissive element layer (62), and a cathode (63) are formed in this order. Consequently, light emitted from the emissive element layer (62) is prevented from reflecting at interfaces between these insulating films (12, 15, and 17), and efficiently exits from the glass substrate (10) side.

Claims

1. A light emissive display device, comprising, for each pixel:

an emissive element composed of a first electrode of a transparent, electrically conductive material;

an emissive element layer; and

a second electrode of an opaque, electrically conductive material, formed in this order; and

a switching element for driving said emissive element;

wherein

at least part of said first electrode of said emissive element is formed in direct contact with a surface of a transparent substrate, and wherein

said switching element is formed on said transparent substrate,

an insulating layer is formed over said switching element for insulating said emissive element from said switching element except for a necessary region and separating said emissive element from said switching element,

said insulating layer includes an opening in each pixel region, and

said first electrode of said emissive element covers the surface of said transparent substrate exposed by the opening.

2. The device according to claim 1, wherein

said insulating layer includes an interlayer insulating layer, and a planarization insulating layer for planarizing a surface of a region located over said switching element.

3. The device according to claim 2, wherein

said interlayer insulating layer is composed of multiple layers including silicon dioxide and/or silicon nitride, and

said planarization insulating layer includes insulating resin.

4. The device according to claim 2, wherein said first electrode includes indium tin oxide.

5. The device according to claim 1, wherein

said switching element is a thin film transistor, and a gate insulating layer is formed on said transparent substrate for insulating a gate of said thin film transistor from an active layer, and

the opening of said insulating layer passes through said gate insulating layer.

6. The device according to claim 5, wherein

said gate insulating layer includes silicon dioxide,

said interlayer insulating layer composed of multiple layers including silicon dioxide and/or silicon nitride, and

said planarization insulating layer includes insulating resin.

7. The device according to claim 5, wherein said first electrode includes indium tin oxide.

11. The device according to claim 1, wherein said emissive element is an electroluminescence element.

12. The device according to claim 1, wherein said emissive element is an organic electroluminescence element including said emissive element layer of an organic compound.

13. The device according to claim 1, wherein light emitted from said emissive element passes through said first electrode and said transparent substrate.

8. A light emissive display device, comprising, for each pixel:

an emissive element composed of a first electrode of a transparent, electrically conductive material;

an emissive element layer; and

a second electrode of an opaque, electrically conductive material, formed in this order; and

a switching element for driving said emissive element;

wherein

at least part of said first electrode of said emissive element is formed in direct contact with a surface of a transparent substrate, and wherein

said switching element is formed on said transparent substrate,

an insulating layer is formed over said switching element for insulating said emissive element from said switching element except for a necessary region and separating said emissive element from said switching element, and

said insulating layer includes, in each pixel region, an opening having a diameter increasing from the center toward an outer end thereof.

14. The device according to claim 8, wherein said emissive element is an electroluminescence element.

15. The device according to claim 8, wherein said emissive element is an organic electroluminescence element including said emissive element layer of an organic compound.

16. The device according to claim 8, wherein light emitted from said emissive element passes through said first electrode and said transparent substrate.

9. A light emissive display device, comprising, for each pixel:

an emissive element composed of a first electrode of a transparent, electrically conductive material;

an emissive element layer; and

a second electrode of an opaque, electrically conductive material, formed in this order; and

a switching element for driving said emissive element;

wherein

at least part of said first electrode of said emissive element is formed in direct contact with a surface of a transparent substrate, and wherein

said switching element is formed on said transparent substrate,

an insulating layer is formed over said switching element for insulating said emissive element from said switching element except for a necessary region and separating said emissive element from said switching element,

said insulating layer includes, in each pixel region, an opening having a diameter increasing from the center toward an outer end thereof,

said first electrode is formed as an individual electrode in each pixel, and

a planarization insulating film is formed in the vicinity of an edge of said first electrode for separating said first electrode from said emissive element layer and said second electrode, and includes a tapered surface having a thickness that increases from the center of said first electrode toward an outer end.

10. The device according to claim 9, wherein

said insulating film for insulating said emissive element from said switching element except for a necessary region and separating the two elements includes

an interlayer insulating film including silicon dioxide, and a planarization insulating film including silicon nitride and planarizing a surface of a region located over said switching element.

17. The device according to claim 9, wherein said emissive element is an electroluminescence element.

18. The device according to claim 9, wherein said emissive element is an organic electroluminescence element including said emissive element layer of an organic compound.

19. The device according to claim 9, wherein light emitted from said emissive element passes through said first electrode and said transparent substrate.

20. A light emissive display device, comprising, for each pixel:

an emissive element composed of a first electrode of a transparent, electrically conductive material;

an emissive element layer; and

a second electrode of an opaque, electrically conductive material, formed in this order; and

a switching element for driving said emissive element;

wherein

at least part of said first electrode of said emissive element is formed in direct contact with a surface of a transparent substrate, wherein

said switching element is formed on said transparent substrate,

an insulating layer is formed over said switching element for insulating said emissive element from said switching element except for a necessary region and separating said emissive element from said switching element,

said insulating layer includes an opening in each pixel region, and

said first electrode of said emissive element covers the surface of said transparent substrate exposed by the opening.

21. A light emissive display device, comprising, for each pixel:

an emissive element composed of a first electrode of a transparent, electrically conductive material;

an emissive element layer; and

a second electrode of an opaque, electrically conductive material, formed in this order; and

a switching element for driving said emissive element;

wherein

at least part of said first electrode of said emissive element is formed in direct contact with a surface of a transparent substrate, wherein

said switching element is formed on said transparent substrate,

an insulating layer is formed over said switching element for insulating said emissive element from said switching element except for a necessary region and separating said emissive element from said switching element, and

said insulating layer includes, in each pixel region, an opening having a diameter increasing from the center toward an outer end thereof.

22. A light emissive display device, comprising, for each pixel:

an emissive element composed of a first electrode of a transparent, electrically conductive material;

an emissive element layer; and

a second electrode of an opaque, electrically conductive material, formed in this order; and

a switching element for driving said emissive element;

wherein

said first electrode of said emissive element is an individual electrode separately formed for each pixel, at least part of said first electrode being formed in direct contact with a surface of a transparent substrate, wherein

said switching element is formed on said transparent substrate,

an insulating layer is formed over said switching element for insulating said emissive element from said switching element except for a necessary region and separating said emissive element from said switching element,

said insulating layer includes an opening in each pixel region, and

said first electrode of said emissive element covers the surface of said transparent substrate exposed by the opening.

23. A light emissive display device, comprising, for each pixel:

an emissive element composed of a first electrode of a transparent, electrically conductive material;

an emissive element layer; and

a second electrode of an opaque, electrically conductive material, formed in this order; and

a switching element for driving said emissive element;

wherein

said first electrode of said emissive element is an individual electrode separately formed for each pixel, at least part of said first electrode being formed in direct contact with a surface of a transparent substrate, wherein

said switching element is formed on said transparent substrate,

an insulating layer is formed over said switching element for insulating said emissive element from said switching element except for a necessary region and separating said emissive element from said switching element, and

said insulating layer includes, in each pixel region, an opening having a diameter increasing from the center toward an outer end thereof.