Collimating device, optical film, backlight module and display apparatus

Patent metadata

Field	Value
Publication number	US-11385396-B2
Application number	US-202017264101-A
Country	US
Kind code	B2
Filing date	May 9, 2020
Priority date	May 13, 2019
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

A collimating device includes at least one microstructure portion. Each microstructure portion includes a bottom surface; a side surface connected to the bottom surface, an angle between the side surface and the bottom surface being an obtuse angle; and a top surface opposite to the bottom surface and connected to the side surface, the top surface being a convex free-form surface.

First claim

What is claimed is:

1. A collimating device, comprising at least one microstructure portion, each microstructure portion including:
a bottom surface;
a side surface connected to the bottom surface, an angle between the side surface and the bottom surface being an obtuse angle; and
a top surface opposite to the bottom surface and connected to the side surface, the top surface being a convex free-form surface; wherein
the convex free-form surface satisfies the following formula:

Δ
⁢

⁢
y

=

n
2

⁢
x

-

n
1

⁢
sin
⁢

⁢
α
⁢

x
2

+

y
2

n
1

⁢
cos
⁢

⁢
α
⁢

x
2

+

y
2

-

n
2

⁢
y

⁢
Δ
⁢

⁢
x

,

wherein (x, y) are coordinates of a point on a free-form curve, the free-form curve being an intersecting line of the convex free-form surface and a reference plane that is perpendicular to the bottom surface; n 1 is a refractive index of a medium that is in contact with the top surface; n 2 is a refractive index of the microstructure portion; α is an angle between light rays emitted from the convex free-form surface and a y-axis, the y-axis being perpendicular to the bottom surface; Δx is a variation of two adjacent points on the free-form curve in an x-axis direction, and Δy is a variation of the two adjacent points in a y-axis direction.

2. The collimating device according to claim 1 , wherein the bottom surface of each microstructure portion is in a shape of a circle; the angle between the bottom surface and the side surface is β, and β satisfies following formula:

β
=

90
°

+

arcsin
⁡

(

n
3

n
2

⁢
sin
⁢

⁢

θ
max

)

-

arctan
⁡

(

R
1

h

)

2

,

wherein θ max is a maximum value of an incident angle θ of light rays incident onto the bottom surface; R 1 is a radius of the circle; h is a height of the microstructure portion in a direction perpendicular to the bottom surface; n 2 is a refractive index of the microstructure portion, and n 3 is a refractive index of a medium that is in contact with the bottom surface.

3. The collimating device according to claim 1 , wherein each microstructure portion has an axis of rotational symmetry that is substantially perpendicular to the bottom surface.

4. The collimating device according to claim 3 , wherein the at least one microstructure portion includes two microstructure portions that intersect; and axes of rotational symmetry of the two microstructure portions are substantially parallel to each other.

5. The collimating device according to claim 4 , wherein bottom surfaces of the two microstructure portions are located in a same plane, and the two microstructure portions are located at a same side of the plane.

6. The collimating device according to claim 4 , wherein edges of the bottom surfaces of the two microstructure portions are tangent.

7. The collimating device according to claim 3 , wherein the at least one microstructure portion includes two microstructure portions, and the collimating device further comprises:
a filling portion provided between the two microstructure portions.

8. An optical film, comprising:
a substrate; and
a plurality of collimating devices according to claim 1 that are arranged in an array in the substrate, wherein bottom surfaces of microstructure portions of the collimating devices are substantially parallel to a surface of the substrate proximate to the bottom surfaces of the microstructure portions of the collimating devices.

Assignees

• Hefei Boe Optoelectronics Tech
• Boe Technology Group Co Ltd

Inventors

• Tang Hai
• Gao Liang
• Zhang Bing
• Geng Xiaolin

Classifications

• G02B6/005 Primary

  provided by one optical element, or plurality thereof, placed on the light output side of the light guide · CPC title

• G02F1/133607

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

• G02F1/133605

  including specially adapted reflectors · CPC title

• G02F1/133524

  Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides · CPC title

• F21V5/04

  of lens shape · CPC title