BACKLIGHT UNIT AND DISPLAY DEVICE HAVING THE SAME

• US 20200132914A1
• Filed: 10/15/2019
• Published: 04/30/2020
• Est. Priority Date: 10/29/2018
• Status: Abandoned Application

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: SONG, Hee Kwang, KIM, Hyun Jeong
• Application Number:
  US16/653,634
• Publication Number:
  US 20200132914A1
• Time in Patent Office: Days
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements

Abstract

A backlight unit comprising a light guide plate, a wavelength conversion layer disposed on the light guide plate and an optical film disposed on the wavelength conversion layer. The optical film includes a first film including a prism pattern layer, and a first low-refractive layer disposed on the first film and having a complementary shape to the prism pattern layer. The first low-refractive layer has a refractive index smaller than a refractive index of the first film.

Claims

1. A backlight unit comprising:

a light guide plate;

a wavelength conversion layer disposed on the light guide plate; and

an optical film disposed on the wavelength conversion layer, wherein the optical film comprises;

a first film comprising a prism pattern layer; and

a first low-refractive layer disposed on the first film and having a complementary shape to the prism pattern layer, and

wherein the first low-refractive layer has a refractive index less than a refractive index of the first film.

2. The backlight unit of claim 1, wherein the refractive index of the first low-refractive layer is in a range from about 1.2 to about 1.28.

3. The backlight unit of claim 1, wherein an upper surface of the first low-refractive layer is parallel to a lower surface of the first film.

4. The backlight unit of claim 3, wherein

the prism pattern layer comprises convex portions and concave portions, and

a first distance from a vertex of each of the convex portions to the upper surface of the first low-refractive layer is smaller than a second distance from a vertex of each of the concave portions to the upper surface of the first low-refractive layer.

5. The backlight unit of claim 1, further comprising:

a second low-refractive layer between the light guide plate and the wavelength conversion layer,

wherein the second low-refractive layer is in contact with the light guide plate.

6. The backlight unit of claim 5, wherein a refractive index of the second low-refractive layer is equal to the refractive index of the first low-refractive layer.

7. The backlight unit of claim 6, further comprising:

a light source disposed adjacent to a side of the light guide plate.

8. The backlight unit of claim 7, wherein

the light source emits a first light and a second light,

the first light is a near-ultraviolet light having a peak wavelength between about 390 nm and about 410 nm, and

the second light is a blue light having a peak wavelength between about 430 nm and about 470 nm.

9. The backlight unit of claim 7, wherein

the wavelength conversion layer comprises a first wavelength conversion material and a second wavelength conversion material,

wherein the first wavelength conversion material converts light emitted from the light source into a green light, and

the second wavelength conversion material converts the light emitted from the light source into a red light.

10. The backlight unit of claim 1, further comprising:

a second film disposed between the first film and the wavelength conversion layer, wherein the second film comprises a scattering layer.

11. The backlight unit of claim 10, wherein the optical film further comprises:

a third film comprising a prism pattern disposed on the first low-refractive layer; and

a fourth film comprising a reflective polarizing layer.

12. The backlight unit of claim 11, wherein the optical film further comprises a protective layer,

wherein the protective layer is in contact with a lower surface of the first film, in contact with side surfaces of each of the first film, the second film and the first low-refractive layer, and in contact with an upper surface of the first low-refractive layer.

13. The backlight unit of claim 1, further comprising:

a reflection member disposed under the light guide plate.

14. The backlight unit of claim 13, wherein the light guide plate comprises a scattering pattern disposed on a surface opposite to a surface facing the wavelength conversion layer.

15. A display device comprising:

a backlight unit comprising a light guide plate, a wavelength conversion layer disposed on the light guide plate, an optical film disposed on the wavelength conversion layer, and a light source disposed on a side of the light guide plate; and

a display panel disposed above the backlight unit,

wherein the optical film comprises

a first film comprising a prism pattern layer, and

a first low-refractive layer disposed on the first film and having a complementary shape to the prism pattern layer, and

wherein the first low-refractive layer has a refractive index less than a refractive index of the first film.

16. The display device of claim 15, wherein the refractive index of the first low-refractive layer is in a range from about 1.2 to about 1.28.

17. The display device of claim 16, wherein an upper surface of the first low-refractive layer is parallel to a lower surface of the first film.

18. The display device of claim 17, further comprising:

a second film disposed between the first film and the wavelength conversion layer, wherein the second film comprises a scattering layer.

19. The display device of claim 18, wherein

the light source emits a first light and a second light,

wherein the first light is a near-ultraviolet light having a peak wavelength between about 390 nm and about 410 nm, and

the second light is a blue light having a peak wavelength between about 430 nm and about 470 nm.

20. The display device of claim 19, further comprising:

an inter-module coupling member disposed at an edge of the wavelength conversion layer,

wherein the inter-module coupling member couples the light guide plate with the display panel,

wherein the optical film is disposed in a space surrounded by the light guide plate, the display panel and the inter-module coupling member.