Lighting systems and devices including same

• US 9,207,385 B2
• Filed: 11/11/2010
• Issued: 12/08/2015
• Est. Priority Date: 05/06/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: QD Vision, Inc. (Samsung Electronics Co. Ltd.)
• Inventors: Coe-Sullivan, Seth, Linton, John R., Cohen, Daniel, Ritter, John E.
• Primary Examiner(s): WONG, ERIC K
• Application Number:
  US12/944,681
• Publication Number:
  US 20110199555A1
• Time in Patent Office: 1,853 Days
• Field of Search: 349/62, 362/601
• US Class Current: 1/1
• CPC Class Codes: G02B 6/0026 Wavelength selective element, sheet or layer, e.g. filter or grating
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]

Abstract

A lighting system is disclosed. The lighting system comprises at least one light source comprising a light emitting diode (LED) and one or more phosphors optically coupled to the LED to convert at least a portion of original light emitted by the LED to provide a modified LED light having a first predetermined spectral output, and an optical material that is optically coupled to at least a portion of a surface of a light guide plate and optically coupled to receive at least a portion of the modified LED light and to convert at least a portion of the modified LED light to at least one predetermined wavelength to provide modified light having a second predetermined spectral output, wherein the optical material comprises one or more types of quantum confined semiconductor nanoparticle. A device including a lighting system is also disclosed.

Claims

1. A lighting system comprising:

at least one light source comprising a phosphor-converted light emitting diode (LED), wherein one or more phosphors are optically coupled to the LED to convert at least a portion of original light emitted by the LED to provide a modified LED light having a first predetermined spectral output, and

an optical material that is optically coupled to at least a portion of a surface of a light guide plate and optically coupled to receive at least a portion of the modified LED light from the light source and to convert at least a portion of the modified LED light to at least one predetermined wavelength to provide modified light having a second predetermined spectral output, wherein the optical material comprises a first type of quantum confined semiconductor nanoparticle capable of emitting red light and a second type of quantum confined semiconductor nanoparticle capable of emitting green light, wherein the optical material is spaced from the light source, and wherein the second predetermined spectral output includes a red component having a CIE x>

0.64.

2. A lighting system in accordance with claim 1 wherein the optical material is positioned between the light source and the light guide plate.

3. A lighting system in accordance with claim 2 wherein the optical material is positioned between the light source and an edge surface of the light guide plate.

4. A lighting system in accordance with claim 2 wherein the optical material is positioned between the light source and a major surface of the light guide plate.

5. A lighting system in accordance with claim 1 wherein the light guide plate is positioned between the light source and the optical material.

6. A lighting system in accordance with claim 1 wherein the optical material is included in a layer disposed over a surface of the light guide plate.

7. A lighting system in accordance with claim 1 wherein modified light having a second predetermined spectral output is emitted from the lighting system.

8. A lighting system in accordance with claim 1 wherein the optical material further comprises a host material in which the quantum confined semiconductor nanoparticles are distributed.

9. A lighting system in accordance with claim 8 wherein quantum confined semiconductor nanoparticles are included in the host material in an amount in the range from about 0.001 to about 5 weight percent of the weight of the host material.

10. A lighting system in accordance with claim 9 wherein the optical material further includes scatterers in an amount in the range from about 0.001 to about 5 weight percent of the weight of the optical material.

11. A lighting system in accordance with claim 1 wherein the optical material further includes scatterers in an amount in the range from about 0.001 to about 5 weight percent of the weight of the optical material.

12. A lighting system in accordance with claim 1 wherein the temperature at the location of the nanoparticles during operation of the lighting system is less than 90°

C.

13. A lighting system in accordance with claim 1 wherein the optical material does not include phosphor particles.

14. A lighting system in accordance with claim 1 which does not include a filter layer.

15. A lighting system in accordance with claim 1 wherein optical material is included in a layer disposed over a predetermined area of the surface of the light guide plate to which it is optically coupled.

16. A lighting system in accordance with claim 1 wherein the optical material further comprises scatterers.

17. A lighting system in accordance with claim 1 further comprising means for coupling light from the light source into the light guide plate.

18. A lighting system in accordance with claim 1 wherein the LED is encapsulated with an encapsulant including one or more phosphors.

19. A lighting system in accordance with any of claim 1 wherein the light source comprises at least one phosphor-converted LED comprising a blue LED including one or more phosphors optically coupled thereto to provide a white modified LED light.

20. A lighting system in accordance with any of claim 1 wherein the light source comprises at least one phosphor-converted LED comprising a blue LED including one or more phosphors optically coupled thereto to provide an off-white modified LED light that includes a spectral output including at least one spectral component in a first spectral region from about 360 nm to about 475 nm, at least one spectral component in a second spectral region from about 475 nm to about 575 nm.

21. A device comprising a liquid crystal display including a lighting system in accordance with claim 1.

22. A backlight unit for a liquid crystal display, the unit comprising a lighting system in accordance with claim 1.

23. A backlight unit in accordance with claim 22 wherein the backlight unit includes one or more red subpixels and wherein the red subpixel power efficiency is improved by a factor of greater than 1 up to about 3 compared to a backlight unit that utilizes no additional red emitting material to add a red spectral component to the lighting system output.

24. A lighting system in accordance with claim 1 wherein the light source is optically coupled to an edge of the light guide plate.

25. A lighting system in accordance with claim 1 wherein outcoupling structures are included across a surface of the light guide plate.

26. A lighting system in accordance with claim 1 wherein the second predetermined spectral output includes red peak emission, blue peak emission, and green peak emission.

27. A lighting system in accordance with claim 1 wherein quantum confined semiconductor nanoparticles are included within or adsorbed onto polymer particles.

28. A lighting system in accordance with claim 1 wherein the optical material is included in a layer disposed on the surface of the light guide plate to which it is optically coupled.

29. A lighting system in accordance with claim 8 wherein the optical material further comprises scatterers.