Backlight module and display device

Patent metadata

Field	Value
Publication number	US-11506830-B2
Application number	US-201816338799-A
Country	US
Kind code	B2
Filing date	Sep 6, 2018
Priority date	Sep 26, 2017
Publication date	Nov 22, 2022
Grant date	Nov 22, 2022

Abstract

A backlight module and a display device are provided. The backlight module includes a polarizing light guide plate configured to convert incident light into first polarized light and second polarized light, a polarization direction of the first polarized light being perpendicular to a polarization direction of the second polarized light.

First claim

What is claimed is:

1. A backlight module comprising:
a polarizing light guide plate configured to convert incident light into first polarized light and second polarized light, wherein a polarization direction of the first polarized light is perpendicular to a polarization direction of the second polarized light, and wherein the polarizing light guide plate comprises a Glan prism that comprises a first prism and a second prism;
a light source located adjacent to a first side surface of the first prism, wherein a light emitting direction of the light source is perpendicular to the first side surface of the first prism;
a first reflective sheet located adjacent to a second side surface of the second prism and configured to reflect the second polarized light, passing through the polarizing light guide plate, back to the polarizing light guide plate and toward the light source; and
a second reflective sheet located adjacent to the first side surface of the first prism and facing the first reflective sheet, and configured to reflect the reflected second polarized light by the first reflective sheet back to the polarizing light guide plate and to change a polarization state of the second polarized light,
wherein the light source comprises a substrate and a light emitting device on the substrate, and wherein the second reflective sheet and the light emitting device are located on a same side of the substrate and not overlapping in a direction parallel to the substrate.

2. The backlight module according to claim 1 , wherein the first polarized light is generated by reflection of the incident light within the polarizing light guide plate.

3. The backlight module according to claim 1 , wherein the first prism includes a first inclined surface, a first bottom surface, and the first side surface arranged to be orthogonal to the first bottom surface, wherein the first side surface is a rectangular surface;
wherein the second prism includes a second inclined surface, a second bottom surface, and the second side surface arranged to be orthogonal to the second bottom surface, wherein the second side surface is a rectangular surface; and
wherein the first inclined surface of the first prism is attached to the second inclined surface of the second prism, and wherein the first polarized light exits from the first bottom surface after being reflected at the first inclined surface.

4. A display device comprising the backlight module of claim 1 .

5. The display device according to claim 4 , further comprising:
a liquid crystal module arranged on a light-exiting side of the backlight module.

6. The display device according to claim 5 , further comprising:
a polarizer arranged on a side of the liquid crystal module away from the backlight module, wherein a light transmission direction of the polarizer is perpendicular to the polarization direction of the first polarized light.

7. The display device according to claim 6 , wherein a light transmittance of the polarizing light guide plate is higher than a light transmittance of the polarizer.

8. The display device according to claim 3 , wherein the display device is a transparent liquid crystal display device.

9. The display device according to claim 8 , wherein the first polarized light is generated by reflection of the incident light within the polarizing light guide plate.

10. The display device according to claim 4 ,
wherein the first prism includes a first inclined surface, a first bottom surface, and the first side surface arranged to be orthogonal to the first bottom surface, wherein the first side surface is a rectangular surface; and
wherein the second prism includes a second inclined surface, a second bottom surface, and the second side surface arranged to be orthogonal to the second bottom surface, wherein the second side surface is a rectangular surface;
wherein the first inclined surface of the first prism is attached to the second inclined surface of the second prism, and wherein the first polarized light exits from the first bottom surface of the first prism after being reflected at the first inclined surface.

Assignees

• Beijing Boe Optoelectronics Tech Co Ltd
• Boe Technology Group Co Ltd
• Beijing Boe Technology Dev Co Ltd

Inventors

• Lin Donglong
• Wu Peng
• Tong Zeyuan
• Li Wenyang
• Ren Fujian
• Cui Dong
• Zhang Zhipeng
• Long Bin
• Yoon Dae Keun
• Ma Qing
• Han Rui
• Sun Pai

Classifications

• G02B6/0056 Primary

  for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements · CPC title

• G02F1/13355

  Polarising beam splitters [PBS] · CPC title

• G02F1/133615 Primary

  Edge-illuminating devices, i.e. illuminating from the side · CPC title

• G02B6/0055

  Reflecting element, sheet or layer · CPC title

• G02F1/13362

  providing polarized light, e.g. by converting a polarisation component into another one · CPC title