Light guide assembly, light collimation assembly, backlight module and display device

Patent metadata

Field	Value
Publication number	US-10761259-B2
Application number	US-201916527304-A
Country	US
Kind code	B2
Filing date	Jul 31, 2019
Priority date	Oct 26, 2018
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

A light guide assembly, a light collimation assembly, a backlight module and a display device are provided. The light guide assembly includes a first prism sheet, a dielectric layer and a second prism sheet sequentially laminated, a light refractive index of the dielectric layer is smaller than that of the first prism sheet and that of the second prism sheet, the first prism sheet includes a light incident side surface, and a first plane and a first prism surface, the first plane is closer to the dielectric layer, and the first prism surface includes first prism portions extending along a second direction, the second prism sheet includes a second plane and a second prism surface, the second plane is closer to the dielectric layer, the second prism surface includes second prism portions extending along the second direction, and the second prism portion has a reflection surface.

First claim

The invention claimed is:

1. A light guide assembly, comprising: a first prism sheet, a dielectric layer and a second prism sheet which are sequentially laminated along a first direction,
wherein a light refractive index of the dielectric layer is smaller than a light refractive index of the first prism sheet and a light refractive index of the second prism sheet;
the first prism sheet includes a light incident side surface, and a first plane and a first prism surface which are opposite to each other, the first plane is closer to the dielectric layer with respect to the first prism surface, and the first prism surface includes a plurality of first prism portions extending along a second direction;
the second prism sheet includes a second plane and a second prism surface which are opposite to each other, the second plane is closer to the dielectric layer with respect to the second prism surface, the second prism surface includes a plurality of second prism portions extending along the second direction, and the second prism portion has a reflection surface;
the first prism sheet is configured to receive light being incident to the light incident side surface, totally reflect light with an included angle not smaller than a first angle with a surface of the dielectric layer by the first prism portion, and reduce an included angle between the light being totally reflected and the first direction;
the second prism sheet is configured to enable light incident to the second prism portion through the second plane to be reflected towards the first direction by the reflection surface of the second prism portion and emerge from the first prism surface;
wherein the second direction is parallel to the light incident side surface, and the first angle is a total reflection critical angle between the first prism sheet and the dielectric layer;
the plurality of second prism portions are continuously disposed on the second prism surface;
a main cross-section of the second prism portion is of a triangle shape;
the second prism portion includes a third sub prism surface; and
the third sub prism surface is configured as the reflection surface, a vertex of an included angle α 3 between a plane where the third sub prism surface is positioned and the second plane is away from the light incident side surface, and the included angle α 3 is calculated by a formula below:

α
⁢

⁢
3

=

1
2

⁢

arcsin
⁡

[

⁢

n
⁢

⁢
1

n
⁢

⁢
3

×

sin
⁡

(

arcsin
⁡

(

n
⁢

⁢
2

n
⁢

⁢
1

)

-

α
⁢

⁢
1

)

]

where n1 represents a refractive index of the first prism sheet, n2 represents a refractive index of the dielectric layer, n3 represents a refractive index of the second prism sheet, and α1 is an included angle between the first sub prism surface and the first plane.

2. The light guide assembly according to claim 1 , wherein the first prism portion includes a first prism portion surface positioned on a side of the first prism sheet, which is away from the dielectric layer, a first included angle between a tangent plane at each point in the first prism portion surface and the first plane is γ1, where 0°<γ1≤10°, and a vertex of the first included angle is away from the light incident side surface.

3. The light guide assembly according to claim 2 , wherein the first prism portion surface is an inclined plane or a curved surface; or
the first prism portion surface includes a plurality of inclined plane portions, and two adjacent inclined plane portions in the plurality of inclined plane portions have different first included angles.

4. The light guide assembly according to claim 2 , wherein the first prism portion further includes a second prism portion surface intersecting with the first prism portion surface, a second included angle between a tangent plane at each point in the second prism portion surface and the first plane is γ2, where 15°<γ2≤90°, and a vertex of the second included angle is close to the light incident side surface.

5. The light guide assembly according to claim 2 , wherein
the first prism surface further includes a plurality of first plane portions, each of the plurality of first plane portions is positioned between the adjacent first prism portions.

6. The light guide assembly according to claim 2 , wherein the first prism portion is of a block shape, and an arrangement density of the first prism portion is increased along a direction away from the light incident side surface.

7. The light guide assembly according to claim 5 , wherein the first prism portion is of a strip shape,
at least one of at least two first prism portions and at least two first plane portions is different in width in a third direction, wherein the third direction is perpendicular to the second direction.

8. The light guide assembly according to claim 2 , wherein a main cross-section of the first prism portion along the first directi

Assignees

• Hefei Boe Optoelectronics Tech
• Boe Technology Group Co Ltd

Inventors

• Tang Hai
• Jie Jingbin
• Gao Liang
• Zhang Bing
• Geng Xiaolin
• Gao Lu
• Han Bo
• Qin Jianwei

Classifications

• G02B6/0065

  Manufacturing aspects; Material aspects · CPC title

• G02B6/0061

  to provide homogeneous light output intensity · CPC title

• G02B6/0053 Primary

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

• G02B6/0038

  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

• G02B6/0036

  2-D arrangement of prisms, protrusions, indentations or roughened surfaces · CPC title