Planar directed light source

• US 7,011,420 B2
• Filed: 09/04/2002
• Issued: 03/14/2006
• Est. Priority Date: 09/04/2002
• Status: Expired due to Term

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Cok, Ronald S.
• Primary Examiner(s): Husar, Stephen
• Assistant Examiner(s): Lee, Guiyoung
• Application Number:
  US10/234,553
• Publication Number:
  US 20040042198A1
• Time in Patent Office: 1,287 Days
• Field of Search: 362/84, 362/244, 362/800, 362/226, 362/98, 362/330, 362/355, 362/333, 362/237, 362/331, 257/98, 313/504, 359/15
• US Class Current: 362/84
• CPC Class Codes: F21Y 2105/00 Planar light sources
• CPC Class Codes: F21Y 2115/15 Organic light-emitting diodes [OLED]
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A solid-state light source includes a planar substrate, a single unitary organic light emitting diode (OLED) layer deposited on the planar substrate, the organic light emitting diode layer including first and second electrodes for providing electrical power to the OLED layer, an encapsulating cover covering the OLED layer; first and second conductors electrically connected to the first and second electrodes, and extending beyond the encapsulating cover for making electrical contact to the first and second electrodes by an external power source; and a lenslet array located on the substrate and/or encapsulating cover and coextensive with the OLED layer for directing the light emitted by the OLED layer.

Claims

1. A solid-state area illumination light source, comprising:

a) a planar substrate,

b) a non-pixellated organic light emitting diode (OLED) layer deposited on the planar substrate, the organic light emitting diode layer including first and second electrodes for providing electrical power to the OLED layer,

c) an encapsulating cover covering the OLED layer;

d) first and second conductors electrically connected to the first and second electrodes, and extending beyond the encapsulating cover for making electrical contact to the first and second electrodes by an external power source; and

e) a lenslet array located on the encapsulating cover and coextensive with the OLED layer for directing the light emitted by the OLED layer, wherein the encapsulating cover is transparent, and light is emitted from the OLED layer through the encapsulating cover.

2. The solid-state light source claimed in claim 1, wherein the lenslet array is formed in the encapsulating cover.

3. The solid-state light source claimed in claim 1, wherein the lenslet array is attached to the encapsulating cover by an optical adhesive.

4. The light source claimed in claim 1, wherein the substrate is a rigid planar substrate.

5. The light source claimed in claim 1, wherein the substrate is flexible.

6. The light source claimed in claim 5, further comprising a support for holding the substrate in a plane.

7. The lighting apparatus claimed in claim 1, wherein the lenslet array is embossed.

8. The lighting apparatus claimed in claim 1, wherein the lenslet array is molded.

9. The light source claimed in claim 1, wherein the cover is a hermetically sealed cover plate.

10. The light source claimed in claim 1, wherein the cover is a coated layer.

11. The lighting apparatus claimed in claim 1, wherein the light source operates on standard power.

12. The lighting apparatus claimed in claim 1, wherein the planar substrate is transparent.

13. The lighting apparatus claimed in claim 1, wherein the planar substrate is transparent, and light is emitted from the OLED layer through the encapsulating cover and through the planar substrate.

14. The lighting apparatus claimed in claim 1, wherein the OLED layer emits light through the encapsulating cover and further includes a reflective layer between the light emitter and the substrate.

15. The light source claimed in claim 13,

wherein a lenslet array is located on each of the substrate and the cover.

16. The light source claimed in claim 1, wherein the lenslets are hemispheres.

17. The light source claimed in claim 1, wherein the lenslets are pyramids.

18. The light source claimed in claim 1, wherein the lenslets are cones.

19. The light source claimed in claim 1, wherein the lenslets are fresnel lenslets.

20. The light source claimed in claim 1, wherein the lenslets have a focal length less than 1 mm, and are arranged such that their focal point is located at the light emitting layer.