Backlight module and display apparatus

Patent metadata

Field	Value
Publication number	US-11635656-B2
Application number	US-202117344054-A
Country	US
Kind code	B2
Filing date	Jun 10, 2021
Priority date	Jun 29, 2020
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

The present disclosure discloses a backlight module and a display apparatus. A microprism film layer is further arranged on a light emitting side of a light guide plate, and the microprism film layer is located in a range of a preset distance by which the light guide plate extends from a side close to a light source to a side away from the light source; and the microprism film layer includes a plurality of first microprism structures, and the first microprism structures are configured to make an incident angle of light at a first interface when entering the first microprism structures greater than an emitting angle of the light at the first interface when exiting from the first microprism structures when the light in the light guide plate enters the first microprism structures from the light guide plate and then enters the light guide plate from the first microprism structures.

First claim

What is claimed is:

1. A backlight module, comprising: a light source, a light guide plate and a microprism film layer, wherein
light emitted by the light source is incident into the light guide plate in a side-entry mode;
the light guide plate is provided with a plurality of dots on a backlight side thereof, and the plurality of dots and the light guide plate are an integral structure;
a refractive index of the microprism film layer is same as that of the light guide plate, the microprism film layer is located on a light emitting side of the light guide plate, and the microprism film layer is located in a range of a preset distance by which the light guide plate extends from a side close to the light source to a side away from the light source;
the microprism film layer comprises a plurality of first microprism structures, the first microprism structures are configured to make an incident angle of light at a first interface when entering the first microprism structures greater than an emitting angle of the light at the first interface when exiting from the first microprism structures in response to that the light in the light guide plate entering the first microprism structures from the light guide plate and then entering the light guide plate from the first microprism structures, and the first interface is an interface between the light guide plate and the first microprism structures; and
a pattern of the dots and a pattern of the first microprism structures are mirror-symmetrical about the light guide plate, a cross-section of each of the first microprism structures in a first direction is a triangle, a base angle of a side of the triangle away from the light source ranges from 2° to 10°, and the first direction is a direction perpendicular to the light source.

2. The backlight module according to claim 1 , wherein a height of the triangle is 2 μm to 5 μm.

3. The backlight module according to claim 2 , wherein a base angle of a side of the triangle close to the light source ranges from Arcsin (1/n) to 90°, and n is the refractive index of the microprism film layer; and
a cross-section of each of the first microprism structures in a second direction is a trapezoid, a base angle of the trapezoid ranges from Arcsin (1/n) to 90°, and the second direction is a direction parallel to the light source.

4. The backlight module according to claim 3 , wherein a length of a bottom edge of the trapezoid is 20 μm to 70 μm; and a length of a bottom edge of the triangle is 20 μm to 70 μm.

5. The backlight module according to claim 1 , wherein the plurality of first microprism structures in the microprism film layer are arranged on the light emitting side of the light guide plate in a two-dimensional array;
a row direction of the two-dimensional array is parallel to the light source, and a column direction of the two-dimensional array is perpendicular to the light source;
a spacing between centers of two adjacent first microprism structures in the column direction is 0.1 mm to 0.3 mm; and
a spacing between centers of two adjacent first microprism structures in the row direction is 0.1 mm to 0.4 mm.

6. The backlight module according to claim 1 , wherein the light guide plate and the microprism film layer are of an integrated structure.

7. The backlight module according to claim 1 , further comprising: an inverse prism sheet; wherein the microprism film layer is located between the inverse prism sheet and the light guide plate.

8. A display apparatus, comprising: a liquid crystal display panel and a backlight module, wherein the backlight module comprises: a light source, a light guide plate and a microprism film layer, wherein
light emitted by the light source is incident into the light guide plate in a side-entry mode;
the light guide plate is provided with a plurality of dots on a backlight side thereof, and the plurality of dots and the light guide plate are an integral structure;
a refractive index of the microprism film layer is same as that of the light guide plate, the microprism film layer is located on a light emitting side of the light guide plate, and the microprism film layer is located in a range of a preset distance by which the light guide plate extends from a side close to the light source to a side away from the light source;
the microprism film layer comprises a plurality of first microprism structures, the first microprism structures are configured to make an incident angle of light at a first interface when entering the first microprism structures greater than an emitting angle of the light at the first interface when exiting from the first microprism structures in response to that the light in the light guide plate entering the first microprism structures from the light guide plate and then entering the light guide plate from the first microprism structures, and the first interface is an interface between the light guide plate and the first microprism structures; and
a pattern of the dots and a pattern of the first microprism structures are mirror-symmetrical about the light guide plate, a cross-section of each of the first microprism structures in a first direction is a triangle, a base angle of a side of the triangle away from the light source ranges from 2° to 10°, and the first direction is a direction perpendicular to the light source.

9. The display apparatus according to claim 8 , wherein a height of the triangle is 2 μm to 5 μm.

10. The display apparatus according to claim 9 , wherein a base angle of a side of the triangle close to the light source ranges from Arcsin (1/n) to 90°, and n is the refractive index of the microprism film layer; and a cross-section of each of the first microprism structures in a second direction is a trapezoid, a base angle of the trapezoid ranges from Arcsin (1/n) to 90°, and the second direction is a direction parallel to the light source.

11. The display apparatus according to claim 10 , wherein a length of a bottom edge of the trapezoid is 20 μm to 70 μm; and a length of a bottom edge of the triangle is 20 μm to 70 μm.

12. The display apparatus according to claim 8 , wherein the plurality of first microprism structures in the microprism film layer are arranged on the light emitting side of the light guide plate in a two-dimensional array;
a row direction of the two-dimensional array is parallel to the light source, and a column direction of the two-dimensional array is perpendicular to the light source;
a spacing between centers of two adjacent first microprism structures in the column direction is 0.1 mm to 0.3 mm; and
a spacing between centers of two adjacent first microprism structures in the row direction is 0.1 mm to 0.4 mm.

13. The display apparatus according to claim 8 , wherein the light guide plate and the microprism film layer are of an integrated structure.

14. The display apparatus according to claim 8 , wherein the backlight module further comprises: an inverse prism sheet; wherein
the microprism film layer is located between the inverse prism sheet and the light guide plate.

Assignees

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

Inventors

• Wang Qiuli
• Chen Lei
• Wang Zhiqiang
• Ma Xin
• Sun Chuan
• Yao Jianfeng
• Wang Xinyu
• Tan Dingyang

Classifications

• G02B6/0053 Primary

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

• G02F1/133607 Primary

  the light controlling member including light directing or refracting elements, e.g. prisms or lenses · CPC title

• G02B30/33

  involving directional light or back-light sources · CPC title

• G02F1/133606 Primary

  including a specially adapted diffusing, scattering or light controlling members · CPC title

• G02B6/0043

  provided on the surface of the light guide · CPC title