Backlight unit and display device having the same

Patent metadata

Field	Value
Publication number	US-9995869-B2
Application number	US-201514737669-A
Country	US
Kind code	B2
Filing date	Jun 12, 2015
Priority date	Oct 15, 2014
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

A backlight unit includes a light conversion member; a light guide plate including a light exit surface, a rear surface facing the light exiting surface, and connection surfaces including a first surface and a second surface facing each other to connect the light exit surface and the rear surface; a reflective member; and a light source emitting a first color light incident to the first surface and a portion of the first color light reaches the second surface on which the reflective member is disposed to specularly reflect the portion of the first color light. The light conversion member is disposed on the light exit surface, receives the first color light from the light guide plate, and emits a second color light different from the first color light.

First claim

What is claimed is:

1. A backlight unit, comprising:
a light source emitting a first color light;
a light guide plate comprising a light exit surface, a rear surface facing the light exiting surface, and a plurality of connection surfaces connecting the light exit surface and the rear surface, the connection surfaces comprising a first surface, a second surface facing the first surface, and third and fourth surfaces facing each other to connect the first and second surfaces, wherein the first surface faces the light source to receive the first color light and the first color light exits through the light exit surface;
a reflective member disposed on the second surface to specularly reflect a light reaching the second surface, wherein the light reaching the second surface corresponds to a portion of the first color light, the portion of the first color light is incident to the first surface and reaches the second surface;
a plurality of sub-reflective members respectively disposed on the third and fourth surfaces, the sub-reflective members specularly reflecting lights respectively reaching the third and fourth surfaces; and
a light conversion member disposed on the light exit surface and overlapping the entire light exit surface, receiving the first color light from the light guide plate, and emitting a second color light different from the first color light,
wherein a light incident to the reflective member has same wavelength after being reflected from the reflective member; and
wherein the light conversion member comprises quantum dots dispersed to overlap the entire light exit surface.

2. The backlight unit of claim 1 , wherein the light incident to the reflective member has substantially a same wavelength as a wavelength of the light reflected by the reflective member.

3. The backlight unit of claim 1 , wherein the reflective member comprises a polymer material.

4. The backlight unit of claim 1 , wherein the reflective member comprises a metal material.

5. The backlight unit of claim 1 , wherein the second color light is a white light.

6. The backlight unit of claim 5 , wherein the first color light is a blue light.

7. The backlight unit of claim 1 , further comprising an adhesive member disposed on the second surface to couple the light guide plate and the reflective member.

8. The backlight unit of claim 7 , wherein the adhesive member has a refractive index substantially equal to a refractive index of the light guide plate.

9. The backlight unit of claim 7 , wherein the adhesive member is comprised of a polymer material, is optically colorless and transparent and is selected from a pressure sensitive adhesive, a thermal curable material and a photo-curable material.

10. The backlight unit of claim 1 , wherein the light guide plate further comprises reflective patterns disposed on the rear surface facing the light exit surface and the reflective patterns reflect a light reaching the rear surface.

11. The backlight unit of claim 1 , wherein the reflective member comprises an enhanced specular reflector film.

12. A display device comprising:
a receiving unit;
a display panel accommodated in the receiving unit; and
a backlight unit accommodated in the receiving unit and disposed under the display panel to supply a first color light to the display panel, the backlight unit comprising:
a light source emitting a second color light different from a first color light;
a light guide plate comprising a light incident surface facing the light source to receive the second color light, a light exit surface bent from the light incident surface to face the display panel and emitting the second color light to the display panel, a rear surface opposite the light exit surface, and four connecting surfaces connecting the light exit surface and the rear surface, the connecting surfaces including a first connecting surface opposite a second connecting surface, and third and fourth connecting surfaces facing each other to connect the first and second connecting surfaces;
a reflective member disposed on a light facing surface facing the light incident surface to specularly reflect a light reaching the facing surface, and wherein the light reaching the facing surface corresponds to a portion of the second color light incident from the light incident surface;
a light conversion member disposed between the light guide plate and the display panel, overlapping the entire light exit surface, and receiving the second color light exiting through the light exit surface to provide the first color light to the display panel; and
a plurality of sub-reflective members respectively disposed on the third and fourth connecting surfaces, the sub-reflective members specularly reflecting light respectively reaching the third and fourth connecting surfaces, and
wherein a light incident to the reflective member has same wavelength after being reflected from the reflective member.

13. The display device of claim 12 , wherein the light conversion member comprises a quantum dot.

14. The display device of claim 13 , wherein the first color light is a white light.

15. The display device of claim 14 , further comprising an optical member accommodated in the receiving unit and disposed between the light conversion member and the display panel.

16. The display device of claim 12 , wherein the reflective member comprises a polymer material.

17. The display device of claim 12 , wherein the reflective member comprises silver.

18. The display device of claim 12 , wherein the reflective member covers an entire surface of the light facing surface.

Assignees

• Samsung Display Co Ltd

Inventors

• Yeom Dong-Yeol
• Choi Youngjun
• Bang Jinsook

Classifications

• G02B6/0065

  Manufacturing aspects; Material aspects · CPC title

• G02B6/0055 Primary

  Reflecting element, sheet or layer · CPC title

• G02B6/0088

  of the light guide or other optical sheets in the package · CPC title

• G02B6/0041

  provided in the bulk of the light guide · CPC title

• Y10S977/774

  Exhibiting three-dimensional carrier confinement, e.g. quantum dots · CPC title