Backlight module and display device

Patent metadata

Field	Value
Publication number	US-12130463-B2
Application number	US-202218022673-A
Country	US
Kind code	B2
Filing date	Mar 25, 2022
Priority date	Mar 25, 2022
Publication date	Oct 29, 2024
Grant date	Oct 29, 2024

Abstract

Provided in the present disclosure are a backlight module and a display device. The backlight module includes: a first light guide plate, including: a first surface, a second surface, and a first side surface, where the second surface includes a plurality of first mesh points arranged in arrays; at least one first light source, adjacent to the first side surface; a first reverse prism, located on a side of the first surface away from the second surface; a first privacy filter, located on a side of the first reverse prism away from the first light guide plate; a second light guide plate, located on a side of the first privacy filter away from the first reverse prism, and including: a third surface and a fourth surface that are opposite, and a second side surface connecting the third surface and the fourth surface.

First claim

What is claimed is:

1. A backlight module, comprising:
a first light guide plate, comprising: a first surface and a second surface that are opposite, and a first side surface connecting the first surface and the second surface, wherein the second surface comprises a plurality of first mesh points arranged in arrays;
at least one first light source, adjacent to the first side surface;
a first reverse prism, located on a side of the first surface away from the second surface;
a first privacy filter, located on a side of the first reverse prism away from the first light guide plate, wherein the first privacy filter has a first privacy filtering direction, and the first privacy filter is used to block light at a preset angle in the first privacy filtering direction for collimated incident light;
a second light guide plate, located on a side of the first privacy filter away from the first reverse prism, and comprising: a third surface and a fourth surface that are opposite, and a second side surface connecting the third surface and the fourth surface, wherein the third surface is located on a side of the fourth surface away from the first privacy filter, and the fourth surface comprises a plurality of second mesh points arranged in arrays; and
at least one second light source, adjacent to the second side surface.

2. The backlight module according to claim 1 , further comprising:
a viewing angle control module, located on a side of the second light guide plate away from the first privacy filter; and
a first driving circuit, electrically connected to the viewing angle control module, and used to: provide an electric signal to the viewing angle control module, to enable a propagation direction of light that exits after passing through the viewing angle control module to change.

3. The backlight module according to claim 2 , wherein the viewing angle control module comprises: a first conductive layer, a first liquid crystal layer, and a second conductive layer that are stacked.

4. The backlight module according to claim 1 , wherein the third surface comprises a plurality of continuously arranged prism structures.

5. The backlight module according to claim 1 , further comprising:
a semi-transparent and semi-reflective film, located between the first privacy filter and the second light guide plate.

6. The backlight module according to claim 5 , wherein the semi-transparent and semi-reflective film is a polarizer film.

7. The backlight module according to claim 1 , further comprising: a second privacy filter located on the side of the second light guide plate away from the first privacy filter, wherein the second privacy filter has a second privacy filtering direction, and the second privacy filtering direction and the first privacy filtering direction intersect.

8. The backlight module according to claim 7 , wherein the plurality of second mesh points are arranged in arrays in a first direction and a second direction; the first direction and the second direction intersect; and
a shape of each second mesh point is a circle or an ellipse.

9. The backlight module according to claim 8 , wherein a width of the second light guide plate in the first direction is larger than a width of the second light guide plate in the second direction; and the at least one second light source is adjacent to the second side surface in the second direction.

10. The backlight module according to claim 1 , wherein the plurality of second mesh points are arranged in arrays in a first direction and a second direction; the first direction and the second direction intersect; and
a shape of each second mesh point is a wedge; and
the backlight module further comprises: a second reverse prism located on the side of the second light guide plate away from the first privacy filter.

11. The backlight module according to claim 10 , wherein the first privacy filtering direction is the second direction;
a width of the second light guide plate in the first direction is larger than a width of the second light guide plate in the second direction; and
the at least one second light source is adjacent to the second side surface in the second direction.

12. The backlight module according to claim 11 , wherein a cross-sectional pattern of the second mesh point in the first direction is an isosceles trapezoid; and a cross-sectional pattern of the second mesh point in the second direction is a non-right non-isosceles triangle.

13. The backlight module according to claim 1 , wherein a shape of each first mesh point is a wedge.

14. The backlight module according to claim 13 , wherein the first light source and the second light source are located on a same side of the first light guide plate, or the first light source and the second light source are respectively located on two sides of the first light guide plate.

15. The backlight module according to claim 1 , further comprising:
a reflective sheet, located on a side of the second surface away from the first surface.

16. A display device, comprising:
a backlight module; and
a display panel, located on a light exit side of the backlight module;
wherein the backlight module comprises:
a first light guide plate, comprising: a first surface and a second surface that are opposite, and a first side surface connecting the first surface and the second surface, wherein the second surface comprises a plurality of first mesh points arranged in arrays;
at least one first light source, adjacent to the first side surface;
a first reverse prism, located on a side of the first surface away from the second surface;
a first privacy filter, located on a side of the first reverse prism away from the first light guide plate, wherein the first privacy filter has a first privacy filtering direction, and the first privacy filter is used to block light at a preset angle in the first privacy filtering direction for collimated incident light;
a second light guide plate, located on a side of the first privacy filter away from the first reverse prism, and comprising: a third surface and a fourth surface that are opposite, and a second side surface connecting the third surface and the fourth surface, wherein the third surface is located on a side of the fourth surface away from the first privacy filter, and the fourth surface comprises a plurality of second mesh points arranged in arrays; and
at least one second light source, adjacent to the second side surface.

17. The display device according to claim 16 , wherein the backlight module further comprises:
a viewing angle control module, located on a side of the second light guide plate away from the first privacy filter; and
a first driving circuit, electrically connected to the viewing angle control module, and used to: provide an electric signal to the viewing angle control module, to enable a propagation direction of light that exits after passing through the viewing angle control module to change.

18. The display device according to claim 17 , wherein the viewing angle control module comprises: a first conductive layer, a first liquid crystal layer, and a second conductive layer that are stacked.

19. The display device according to claim 16 , wherein the third surface comprises a plurality of continuously arranged prism structures.

20. The display device according to claim 16 , wherein the backlight module further comprises:
a semi-transparent and semi-reflective film, located between the first privacy filter and the second light guide plate.

Assignees

• Beijing Boe Display Tech Co
• Boe Technology Group Co Ltd

Inventors

• Zhang Zhipeng
• Cui Dong
• Chi Weining
• Qi yongle
• Leng Shouyang
• Wang Fengping
• Ma Qing
• Yoon Daekeun
• Li Wenyang
• Zhai Yue
• Zhu Yuanyuan

Classifications

• G02B6/0076 Primary

  Stacked arrangements of multiple light guides of the same or different cross-sectional area · CPC title

• G02B6/0016

  Grooves, prisms, gratings, scattering particles or rough surfaces · CPC title

• G02B6/0038 Primary

  Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide · CPC title

• G02B6/0053

  Prismatic sheet or layer; Brightness enhancement element, sheet or layer · CPC title

• G02F1/1336

  Illuminating devices · CPC title