IP Library › Granted Patent US 9,541,256
Granted Patent B2
US 9,541,256 · App. 14/675,181 · Granted Jan 10, 2017

Light conversion film, and backlight unit and display device having the same

Inventors: Jinwoo Sung (Seoul, KR); Jinmok Oh (Seoul, KR); Byoungkwon Cho (Seoul, KR); Moongoo Choi (Seoul, KR)
Assignee: LG ELECTRONICS INC.
F21V9/16H01L33/502F21Y2113/005
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Quick Facts
Patent No.
US 9,541,256
App. No.
14/675,181
Granted
Jan 10, 2017
Kind
B2
Abstract

A light conversion film including a first barrier film, a light conversion layer disposed on the first barrier film, the light conversion layer including a matrix resin and red quantum dots that are dispersed into the matrix resin, and a second barrier film disposed on the light conversion layer. The light conversion film satisfies following Equation (1): 5≦(weight of quantum dot within light conversion layer/total weight of light conversion layer)×100×t≦50, where, t is a thickness of the light conversion layer.

Claims (64)

1. A light conversion film comprising:

a first barrier film;

a light conversion layer disposed on the first barrier film, the light conversion layer comprising a matrix resin, red quantum dots dispersed into the matrix resin, microphases each including at least the red quantum dots, and a dispersing agent on a surface of the microphases; and

a second barrier film disposed on the light conversion layer,

wherein the light conversion film satisfies the following Equation (1):

5≦(weight of the red quantum dots within the light conversion layer/total weight of light conversion layer)×100×t≦50  Equation (1):,

where t is a thickness of the light conversion layer, and

wherein the light conversion layer has the thickness t of about 5 μm to about 100 μm.

2. The light conversion film according to claim 1 , wherein the light conversion film satisfies Equation (2):

0.05≦(weight of the red quantum dots within the light conversion layer/total weight of light conversion layer)×100≦5  Equation (2):.

3. The light conversion film according to claim 1 , wherein, when excitation light having a wavelength of about 420 nm is irradiated, the light conversion film has emission peaks in a wavelength band of about 400 nm to about 450 nm and a wavelength band of about 600 nm to about 680 nm.

4. The light conversion film according to claim 1 , wherein the microphases include a quantum dot-polymer bead composite or quantum dot-oligomer liquid drop.

5. The light conversion film according to claim 4 , wherein the quantum dot-polymer bead composite further includes:

a polymer of which a portion of a chain is bonded to surfaces of the red quantum dots, the polymer comprising a polar group on a main or side chain thereof.

6. The light conversion film according to claim 4 , wherein the quantum dot-oligomer liquid drop further includes:

oligomer having polar moiety and nonpolar moiety, and

a nonpolar (meth) acrylate monomer.

7. The light conversion film according to claim 1 , wherein the light conversion layer further comprises a light scattering agent.

8. The light conversion film according to claim 7 , wherein the light scattering agent has a content of about 0.1 wt % to about 40 wt % of the total weight of the light conversion layer.

9. The light conversion film according to claim 7 , wherein the light scattering agent comprises a micro scattering agent having a diameter of about 0.5 μm to about 10 μm, a nano scattering agent having a diameter of about 5 nm to about 200 nm, and a combination thereof.

10. The light conversion film according to claim 9 , wherein the micro scattering agent has a content of about 1 wt % to about 40 wt % of the total weight of the light conversion layer.

11. The light conversion film according to claim 9 , wherein the nano scattering agent has a content of about 1 wt % to about 20 wt % of the total weight of the light conversion layer.

12. The light conversion film according to claim 1 , wherein the light conversion layer further comprises a photo-initiator.

13. The light conversion film according to claim 12 , wherein the photo-initiator has a content of about 1 wt % to about 15 wt % of the total weight of the light conversion layer.

14. The light conversion film according to claim 1 , wherein the light conversion layer further comprises a green phosphor.

15. The light conversion film according to claim 14 , wherein when excitation light having a wavelength of about 420 nm is irradiated, the light conversion film has emission peaks in a wavelength band of about 400 nm to about 450 nm, a wavelength band of about 500 nm to about 550 nm, and a wavelength band of about 600 nm to about 680 nm.

16. The light conversion film according to claim 1 , wherein each of the first and second barrier films has a moisture-permeation rate of about 10 −1 g/m 2 /day to about 10 −5 g/m 2 /day under a temperature of about 37.8° C. and relative humidity of about 100%.

17. The light conversion film according to claim 1 , wherein each of the first and second barrier films has a moisture-permeation rate of about 10 −1 cc/m 2 /day to about 10 −2 cc/m 2 /day under a temperature of about 23° C. and relative humidity of about 0%.

18. The light conversion film according to claim 1 , wherein each of the first and second barrier films has a thickness of about 20 μm to about 100 μm.

19. The light conversion film according to claim 2 , wherein the light conversion film has a light conversion efficiency of about 40% to about 80% that are expressed as following Equation (3):

light conversion efficiency={amount of red light emitted from light conversion film/total amount of light absorbed into light conversion film}×100  Equation (3):.

20. The light conversion film according to claim 1 , wherein after the light conversion film is disposed on a light emitting diode package comprising a green phosphor and a blue light emitting diode, a coordinate value measured by using a CIE coordinate system has an x value of about 0.255 to about 0.355.

21. The light conversion film according to claim 1 , wherein, after the light conversion film is disposed on a light emitting diode package comprising a green phosphor and a blue light emitting diode, a coordinate value measured by using a CIE coordinate system has a y value of about 0.255 to about 0.355.

22. A backlight unit comprising:

a light source unit comprising at least one light source; and

a light conversion film disposed on the light source unit,

wherein the light conversion film comprises:

a first barrier film;

a light conversion layer disposed on the first barrier film, the light conversion layer comprising a matrix resin, red quantum dots dispersed into the matrix resin, microphases each including at least the red quantum dots, and a dispersing agent on a surface of the microphases; and

a second barrier film disposed on the light conversion layer,

wherein the light conversion film satisfies following Equation (1):

5≦(weight of the red quantum dots within the light conversion layer/total weight of light conversion layer)×100×t≦50  Equation (1):,

where t is a thickness of the light conversion layer, and

wherein the light conversion layer has the thickness t of about 5 μm to about 100 μm.

23. The backlight unit according to claim 22 , wherein the at least one light source comprises a blue light source and a green light source.

24. The backlight unit according to claim 22 , wherein the light source comprises a light emitting diode package comprising a green phosphor and a blue light emitting diode.

25. The backlight unit according to claim 22 , wherein the light source comprises a blue light source, and

wherein the light conversion film further comprises a green phosphor in the light conversion layer.

26. A display device comprising:

a display panel; and

a backlight unit disposed under the display panel,

wherein the backlight unit comprises:

a light source unit comprising at least one light source; and

a light conversion film disposed on the light source unit,

wherein the light conversion film comprises:

a first barrier film;

a light conversion layer disposed on the first barrier film, the light conversion layer comprising a matrix resin, red quantum dots dispersed into the matrix resin, microphases each including at least the red quantum dots, and a dispersing agent on a surface of the microphases; and

a second barrier film disposed on the light conversion layer,

wherein the light conversion film satisfies following Equation (1):

5≦(weight of the red quantum dots within the light conversion layer/total weight of light conversion layer)×100×t≦50  Equation (1):,

where t is a thickness of the light conversion layer, and

wherein the light conversion layer has the thickness t of abut 5 μm to about 100 μm.

27. The display device according to claim 26 , wherein in the display device, a coordinate value measured by using a CIE coordinate system has an x value of about 0.255 to about 0.355.

28. The display device according to claim 26 , wherein in the display device, a coordinate value measured by using a CIE coordinate system has a y value of about 0.255 to about 0.355.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 1, 2015
From: SUNG, JINWOO; OH, JINMOK; CHO, BYOUNGKWON; CHOI, MOONGOO
To: LG ELECTRONICS INC.
Reel/Frame 035314/0885 →
Priority Claims (1)
KR 10-2014-0175572 · Dec 9, 2014 · national
Continuity (1)
Related Publication 20160161088A1 · Jun 9, 2016