Tiled OLED device with edge light extraction

• US 8,222,804 B2
• Filed: 11/17/2008
• Issued: 07/17/2012
• Est. Priority Date: 11/17/2008
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Inventors: Miller, Michael E., Hamer, John W., Cok, Ronald S.
• Primary Examiner(s): Mai, Anh
• Assistant Examiner(s): Breval, Elmito
• Application Number:
  US12/271,978
• Publication Number:
  US 20100123384A1
• Time in Patent Office: 1,338 Days
• Field of Search: 313495-512
• US Class Current: 313/498
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/854 comprising scattering means
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 59/18 Tiled displays

Abstract

An area-emissive light-emitting diode (LED) device comprises a substrate having an internal substrate surface, an external substrate surface opposite the internal substrate surface, and a substrate edge; an array of area-emissive LED pixels formed on the internal substrate surface with an edge gap between the substrate edge and the LED pixel on the internal substrate surface nearest the substrate edge; and a light-extraction structure formed in the edge gap and at least partially exterior to the LED pixels.

Claims

1. An area-emissive light-emitting diode (LED) device, comprising:

a) a substrate having an internal substrate surface, an external substrate surface opposite the internal substrate surface, and a substrate edge;

b) an array of area-emissive LED pixels formed on the internal substrate surface with an edge gap between the substrate edge and the LED pixel on the internal substrate surface nearest the substrate edge;

c) an array of color filters formed in a layer between each of the area-emissive LED pixels and the internal substrate surface or in a layer on a side of at each of the LED pixels opposite the internal substrate surface;

d) a black matrix formed in a layer between the area-emissive LED pixels;

e) a light-extraction structure formed in the edge gap and at least partially exterior to the LED pixels; and

f) another array of area-emissive LED pixels having another edge gap that is adjoined to the edge gap of the array of area-emissive LED pixels,

wherein the edge gaps emit between 5% to 150% of an average area luminance of the arrays of area-emissive LED pixels.

2. The area-emissive light-emitting diode device of claim 1, wherein a reflective surface is formed in combination with the light-extraction structure.

3. The area-emissive light-emitting diode device of claim 1, wherein the light-extraction structure is located on or in the external substrate surface, on or in the internal substrate surface, or on or in the substrate edge.

4. The area-emissive light-emitting diode device of claim 1, wherein the pixels emit light through the substrate and further comprising a circular polarizer adhered to the external substrate surface.

5. The area-emissive light-emitting diode device of claim 1, wherein the light-extraction structure is further formed between pixels nearest the substrate edge.

6. The area-emissive light-emitting diode device of claim 1, wherein the edge gap is larger than the distance between neighboring pixels.

7. The area-emissive light-emitting diode device of claim 1, further comprising a controller for driving at least one LED pixel nearest the substrate edge with a reduced current compared to other LED pixels in the array.

8. The area-emissive light-emitting diode device of claim 1, wherein at least a portion of the substrate edge is an angled surface formed at an angle other than 90 degrees with respect to the internal or the external substrate surfaces.

9. The area-emissive light-emitting diode device of claim 8, wherein the angled surface is beveled, or partially beveled, to form a flat surface having an angle between 0 and 90 degrees with respect to either the internal or the external substrate surfaces.

10. The area-emissive light-emitting diode device of claim 8, wherein the angled surface has an angle between 55 and 65 degrees.

11. The area-emissive light-emitting diode device of claim 8, wherein the angled surface is an optical surface, so that at least some of the LED pixels are imaged in the area of the edge gap.

12. The area-emissive light-emitting diode device of claim 8, wherein the angled surface is curved.

13. The area-emissive light-emitting diode device of claim 1, further comprising:

a cover having an internal cover surface adhered to the internal substrate surface, an external cover surface opposite the internal cover surface, and having a cover edge and wherein the light-extraction structure is located on the internal cover surface, the external cover surface, or cover edge.

14. The area-emissive light-emitting diode device of claim 13, wherein the cover is transparent and the pixels emit light through the cover and further comprising a circular polarizer adhered to the external cover surface.

15. An area-emissive light-emitting device having tiles formed from a plurality of area-emissive light-emitting diodes of claim 1 and wherein substrate edges of adjoining tiles abut.

16. The area-emissive light-emitting device of claim 15, wherein at least a portion of the substrate edge of each tile has an angled surface formed at an angle other than 90 degrees with respect to the internal or the external substrate surfaces of the tile and the abutted substrate edges of the tiles have parallel surfaces.

17. The area-emissive light-emitting device of claim 15, wherein at least a portion of the substrate edge of each tile has an angled surface formed at an angle other than 90 degrees with respect to the internal or the external substrate surfaces of the tile and the abutted substrate edges of the tiles have an angled surface formed at the same angle.

18. The area-emissive light-emitting diode device of claim 1, wherein the light-extraction structure is a diffuser, a scattering layer, one or more lenslets, a brightness enhancement filter, a grating, a reflective or refractive element, or a photonic crystal.

19. The area-emissive light-emitting diode device of claim 1, wherein the edge gaps emit between 50% to 120% of an average area luminance of the arrays of area-emissive LED pixels.