Organic light emitting devices for illumination

• US 20070029906A1
• Filed: 10/12/2006
• Published: 02/08/2007
• Est. Priority Date: 08/16/2002
• Status: Active Grant

• Current Assignee: Michael Hack, Michael Weaver, Min-Hao Lu
• Original Assignee: Michael Hack, Michael Weaver, Min-Hao Lu
• Inventors: Hack, Michael, Weaver, Michael, Lu, Min-Hao
• Granted Patent: US 8,100,734 B2
• Time in Patent Office: Days
• US Class Current: 313/24
• CPC Class Codes: F21Y 2105/00 Planar light sources
• CPC Class Codes: F21Y 2115/15 Organic light-emitting diodes [OLED]
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/875 Arrangements for extracting light from the devices

Abstract

An organic light emitting device an a method of obtaining illumination from such a device is provided. The device has a plurality of regions, each region having an organic emissive layer adapted to emit a different spectrum of light. The regions in combination emit light suitable for illumination purposes. The area of each region may be selected such that the device is more efficient than an otherwise equivalent device having regions of equal size. The regions may have an aspect ratio of at least about four. All parts of any given region may be driven at the same current.

Claims

1. A method of fabricating an illumination source, capable of producing light, having a CRI value of at least about 80, the method comprising:

fabricating a first stripe, having a first area, the first stripe comprising a first organic emissive layer, adapted to emit a first spectrum of light;

fabricating a second stripe, having a second area, the second stripe comprising a second organic emissive layer, adapted to emit a second spectrum of light; and

connecting a drive voltage supply across each stripe;

wherein

each stripe has an aspect ratio greater than about 4 and a width greater than about 0.5 mm;

the first organic emissive layer in the first stripe emits the first spectrum of light, the second organic emissive layer in the second stripe emits the second spectrum of light, and the first spectrum of light is different from the second spectrum of light when a voltage is applied across the first and second stripes; and

a combination of the light emitted from the emissive layers has a CRI value of at least about 80.

2. The method of claim 1, further comprising fabricating the first and second stripes so that the first area is different from the second area

3. The method of claim 1, further comprising fabricating the stripes in a process comprising stamping emissive materials over a substrate.

4. The method of claim 1, further comprising fabricating the stripes in a process comprising depositing emissive materials by OVJD over a substrate.

5. The method of claim 1, further comprising fabricating each stripe with a width greater than about 5 mm.

6. The method of claim 1, wherein the CRI value is greater than 85.

7. The method of claim 1, wherein the CRI value is greater than 90.

8. The method of claim 1, wherein the CRI value is greater than 95.

9. The method of claim 1, wherein a combination of the first spectrum of light and the second spectrum of has a CIE of (0.33±

0.04, 0.33±

0.07).

10. The method of claim 1, further comprising providing color correction circuitry, adapted to individually control the current passing through each stripe to correct for any differential aging of the stripes.

11. The method of claim 1, further comprising fabricating a third stripe having a third organic emissive layer adapted to emit a third spectrum of light from a third organic emissive material;

wherein

the third spectrum of light differs from the first and second spectra of light; and

a combination of the light emitted from the emissive layers has a CRI value greater than 80 when a voltage is applied across each of the stripes.

12. The method of claim 11, further comprising fabricating the third stripe to have an area different from the first and second areas of the first and second stripes.

13. The method of claim 11, further comprising fabricating the stripes in a process comprising stamping the emissive materials over a substrate.

14. The method of claim 11, further comprising fabricating the stripes in a process comprising depositing the emissive materials by OVJD over a substrate.

15. The method of claim 11, further comprising fabricating each stripe with a width greater than about 5 mm.

16. The method of claim 11, wherein the CRI value is greater than 85.

17. The method of claim 11, wherein the CRI value is greater than 90.

18. The method of claim 11, wherein the CRI value is greater than 95.

19. The method of claim 11, wherein the light has a CIE of (0.33±

0.04, 0.33±

0.07).

20. The method of claim 11, wherein the light has a CIE of (0.33±

0.02, 0.33±

0.02).

21. The method of claim 11, further comprising providing color correction circuitry adapted to individually control the current passing through each stripe to correct for any differential aging of the stripes.

22. A method of fabricating an illumination source, capable of producing light, having a CRI value of at least about 80, the method comprising:

fabricating a plurality of stripes, each stripe having an area, and comprising an organic emissive layer, adapted to emit a spectrum of light, wherein each stripe has an aspect ratio greater than about 4 and a width greater than about 0.5 mm; and

connecting a drive voltage supply across each stripe;

wherein

when a voltage is applied across the plurality of stripes, the stripes emit at least two different spectra of light; and

a combination of the emitted spectra of light has a CRI value of at least about 80.