BACKLIGHT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE INCLUDING THE SAME

• US 20180180944A1
• Filed: 02/02/2018
• Published: 06/28/2018
• Est. Priority Date: 09/07/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jang, Eun-joo, Kang, Hyun-a, Cho, Oul
• Granted Patent: US 10,732,458 B2
• Time in Patent Office: Days
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: G02B 6/0003 the light guides being doped with fluorescent agents
• 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 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133617 Illumination with ultraviolet light; Luminescent elements or materials associated to the cell
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials
• CPC Class Codes: Y10S 977/834 Optical properties of nanomaterial, e.g. specified transparency, opacity, or index of refraction

Abstract

A backlight unit for a liquid crystal display device including a liquid crystal panel, includes: a light source including a light-emitting diode (“ED”) which generates and emits light; and a light converting layer between the light source and the liquid crystal panel, spaced apart from the light source, and converting the light from the light source into white light and emitting the white light toward the liquid crystal panel. The light converting layer includes: semiconductor nanocrystals, and a barrier material which restricts penetration of moisture or oxygen.

Claims

1. A display device comprising:

a semiconductor nanocrystal composite comprising semiconductor nanocrystals and a barrier material having a moisture transmission rate and an oxygen transmission rate of equal to or less than about 0.1 cc/m2/day.

2. The display device of claim 1, further comprising a light source generating and emitting light, wherein the semiconductor nanocrystal composite converts the light from the light source into another light.

3. The display device of claim 2, wherein the semiconductor nanocrystal composite has a shape of film.

4. The display device of claim 3, wherein the semiconductor nanocrystal composite comprises at least one layer including the semiconductor nanocrystals and at least one layer including the barrier material.

5. The display device of claim 3, wherein the semiconductor nanocrystal composite comprises at least one layer including the semiconductor nanocrystals and the barrier material.

6. The display device of claim 2, wherein the semiconductor nanocrystals comprise at least one selected from a Group II-VI material, a Group III-V material, and a Group IV element.

7. The display device of claim 2, wherein the barrier material comprises at least one selected from an organic material and an inorganic material.

8. The display device of claim 2, wherein the light source comprises a light-emitting diode.

9. The display device of claim 8, wherein the semiconductor nanocrystal composite is configured to be spaced apart from the light source.

10. The display device of claim 2, further comprising a liquid crystal panel forming an image by using another light emitted from the semiconductor nanocrystal composite.

11. The display device of claim 10, further comprising a transparent substrate which at least one of the semiconductor nanocrystals and the barrier material is disposed.

12. The display device of claim 11, wherein the transparent substrate comprises polyethylene terephthalate.

13. The display device of claim 10, further comprising a diffusive plate between the light source and the semiconductor nanocrystal composite or between the semiconductor nanocrystal composite and the liquid crystal panel.

14. The display device of claim 10, wherein the semiconductor nanocrystal composite further comprises light diffusing particles which diffuse the light.

15. The display device of claim 14, wherein the semiconductor nanocrystal composite comprises at least one layer including the semiconductor nanocrystals and the light diffusing particles, and at least one layer including the barrier material.

16. The display device of claim 14, wherein the semiconductor nanocrystal composite comprises at least one layer including the semiconductor nanocrystals and the light diffusing particles and the barrier material.

17. The display device of claim 10, further comprising a light guide plate between the light source and the semiconductor nanocrystal composite, wherein the light guide plate guides the light emitted from the light source toward the semiconductor nanocrystal composite.

18. The display device of claim 17, wherein the light guide plate comprises a light emitting first surface, a second surface opposite to the light emitting first surface, and a side surface connecting the first and second surfaces to each other, and the light source faces the side surface of the light guide plate.

19. A semiconductor nanocrystal composite comprising:

semiconductor nanocrystals; and

a barrier material having a moisture transmission rate and an oxygen transmission rate of equal to or less than about 0.1 cc/m2/day.

20. The semiconductor nanocrystal composite of claim 19, wherein the semiconductor nanocrystal composite has a shape of film.

21. The semiconductor nanocrystal composite of claim 20, wherein the semiconductor nanocrystal composite comprises at least one layer including the semiconductor nanocrystals and at least one layer including the barrier material.

22. The semiconductor nanocrystal composite of claim 20, wherein the semiconductor nanocrystal composite comprises at least one layer including the semiconductor nanocrystals and the barrier material.

23. The semiconductor nanocrystal composite of claim 19, wherein the semiconductor nanocrystals comprise at least one selected from a Group II-VI material, a Group III-V material, and a Group IV element.

24. The semiconductor nanocrystal composite of claim 19, wherein the barrier material comprises at least one selected from an organic material and an inorganic material.

25. The semiconductor nanocrystal composite of claim 24, wherein the organic material comprises at least one selected from thiolene, hybrid epoxy, polyurea, polytetrafluoroethylene, polydimethylsiloxane, polyvinylchloride, polycarbonate, polystyrene, polyimide, parylene, polyethylacrylate, and polymethylmethacrylate.

26. The semiconductor nanocrystal composite of claim 24, wherein the inorganic material comprises at least one selected from silicon oxide, aluminum oxide, titanium oxide, indium oxide, tin oxide, indium oxide, tantalum oxide, zirconium oxide, and niobium oxide.