WO2016138677A1

WO2016138677A1 - Backlight unit and light guide plate thereof

Info

Publication number: WO2016138677A1
Application number: PCT/CN2015/074387
Authority: WO
Inventors: 张简圣哲; 樊勇
Original assignee: 深圳市华星光电技术有限公司
Priority date: 2015-03-02
Filing date: 2015-03-17
Publication date: 2016-09-09
Also published as: CN104614802A; CN104614802B

Abstract

A light guide plate (10) used for a backlight unit, comprising a first light inlet side (11) and a second light inlet side (12) of which the width is smaller than that of the first light inlet side (11), first incident light and second incident light are separately imported onto the first light inlet side (11) and the second light inlet side (12) by corresponding light sources, and a plurality of first prisms (21) and second prisms (22) of which the cross sections are trapezoid or triangular or half round are arrayed on the upper surface of the light guide plate (10); long axes of the first prisms (21) are vertical to the first incident light, and long axes of the second prisms (22) are vertical to the second incident light; and a gap exists between the first prisms (21) and between the second prisms (22). The light-emitting efficiency of the light guide plate is improved, the backlight brightness is increased, and meanwhile, in combination with lattice points of the bottom surface of the light guide plate, the uniformity ratio of the backlight brightness and a visual angle can be improved.

Description

Backlight module and light guide plate thereof

Technical field

The invention relates to the technical field of liquid crystal displays, in particular to an improved structure of a light guide plate.

Background technique

With the development of LCD TVs to large size, ultra high definition 4K or even 8K technology, as the pixel unit of the liquid crystal panel increases, the pixel size decreases, the pixel aperture ratio decreases, and the transmittance decreases.

Since the transmittance of the large-sized liquid crystal panel is low, the brightness required for the backlight also increases. For the large-size side-in light, the design of the backlight module, if the single long side enters the light, due to the limitation of the current brightness and heat dissipation of the LED single lamp, coupled with the low transmittance of the large-size high-definition liquid crystal panel, the single Long design, when the brightness does not reach the brightness of the design, it is usually the choice of double short or double long side light. Due to the double-short and double-length side-in-light design, in order to avoid the mura phenomenon caused by the heat and hygroscopic expansion of the light guide plate, and to avoid the expansion of the light guide plate and the LED, the coupling between the LED and the light guide plate is generally increased. Light distance to reduce the risk of warping and the risk of hitting the light. As the coupling distance increases, the coupling efficiency of light entering the light guide plate is greatly reduced. Especially in the models requiring narrow bezel design, in order to avoid edge leakage, a low reflectivity material is usually added above the coupling region to reduce light leakage. The risk of such coupling light is further reduced.

Summary of the invention

In order to overcome the deficiencies of the prior art, the present invention provides a light guide plate for a backlight module, comprising a first light incident side and a second light incident side having a width smaller than the first light incident side, the first input The light side and the second light incident side respectively introduce a first incident light and a second incident light by a corresponding light source, and the surface of the light guide plate is arranged with a plurality of first prisms having a trapezoidal or triangular or semicircular cross section. a prism; a long axis of the first prism is perpendicular to the first incident light, a long axis of the second prism is perpendicular to a direction of the second incident light; and between the first prism and the second prism There is a gap between them.

Further, when the cross section of the first prism and the second prism is a triangle, the apex angle of the triangle is a right angle.

Further, an angle between the first light incident side and the second light incident side is a right angle.

Further, the second prism is interposed between the two rows of first prisms.

The present invention also provides a backlight module including the above-mentioned light guide plate and a light source, that is, the light guide plate includes a first light incident side and a second light incident side having a width smaller than the first light incident side, The first light incident side and the second light incident side respectively introduce a first incident light and a second incident light from the corresponding light source, wherein the surface of the light guide plate is arranged with a plurality of cross sections that are trapezoidal or triangular or semicircular a first prism, a second prism; a long axis of the first prism is perpendicular to the first incident light, and a major axis of the second prism is perpendicular to the second incident light direction; There is a gap between the second prism.

Further, when the cross section of the first prism and the second prism is a triangle, the apex angle of the cross section is a right angle.

Further, the second prism is interposed between the two rows of first prisms.

The invention relates to a light guide plate applied to a backlight module with short-side and long-side mixed light, wherein a plurality of prism structures are arranged on the surface of the light guide plate, which can improve the light-emitting efficiency of the light guide plate, improve the brightness of the backlight, and can be matched with the light guide plate. The bottom mesh improves the brightness uniformity of the backlight and improves the viewing angle.

DRAWINGS

FIG. 1 is a schematic top plan view of a light guide plate according to an embodiment of the invention.

2 is a schematic view of a prism structure of the present invention.

FIG. 3 is a schematic structural diagram of a backlight module according to an embodiment of the present invention.

detailed description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In order to avoid the problem of low coupling efficiency in the double-length and double-short side light-in methods, a new backlight design with short-side and long-side mixed light can be adopted to solve the problem of reduced coupling efficiency and narrowness. The need for a border design.

In order to better improve the backlight efficiency of the backlight with long sides and long sides mixed into the light, the present invention proposes a special microstructure design of the light exit surface of the light guide plate.

As shown in FIG. 1 , the present invention provides a light guide plate 10 for a backlight module, including a first light incident side. 11 and a second light incident side 12 having a width smaller than the first light incident side 11. That is, the first light incident side 11 is the long side of the light guide plate 10, and the second light incident side 12 is the short side of the light guide plate 10. A light source (not shown in FIG. 1) is distributed on the second light incident side 12 (short side, not restricting the left and right direction) and the first light incident side 11 (long side, not limited to the heaven and earth side). The first light incident side 11 and the second light incident side 12 respectively introduce first incident light (perpendicular to the first light incident side 11) and second incident light (perpendicular to the second input) by corresponding light sources. Light side 12).

Further, the upper surface of the light guide plate 10 is arranged with a plurality of prisms 20 having a triangular cross section (as shown in FIG. 2), and can be divided into first prisms 21 and second according to different positions and orientations of the prisms 20 Prism 22. For example, as shown in FIG. 2, for the convenience of production, the configurations of the first prism 21 and the second prism 22 are the same, and both of them have a triangular cross section. Preferably, the apex angle of the cross section is a right angle, and the other two inner corners are not particularly limited. The difference is that the long axis of the first prism 21 is perpendicular to the first incident light, and the long axis of the second prism 22 is perpendicular to the second incident light direction. In this embodiment, the first incident light and the second incident light are perpendicular to the first light incident side 11 and the second light incident side 12, respectively, so that the first prism and the second prism are respectively associated with the first The light incident side 11 and the second light incident side 12 are parallel. Moreover, in the alignment process, the first prisms 21 are sequentially arranged in parallel with the first light incident side 11, and there is a gap between the first prisms 21 in the same row, that is, the first prisms are intermittent rows in one row. Cloth. Similarly, the second prism 22 is interposed between the two rows of first prisms 21, and has a similar discontinuous arrangement. The number of the first prisms in a row does not need to be particularly limited, and can be set in accordance with the size of the prism produced by the production process. The prism can be conveniently disposed on the upper surface of the light guide plate 10 by bonding or the like.

In addition, the lower surface of the light guide plate is provided with a scattering dot (not shown), which may be printed by ink or by hot stamping or rolling. The prism arrangement method can make the light out of the light guide plate more uniform, and greatly improve the light extraction efficiency of the light guide plate, improve the brightness of the backlight, and the design of the scattering dot on the lower surface of the light guide plate can significantly improve the brightness, uniformity and vision of the backlight. effect.

Of course, in other embodiments, the structure of the prism may also be various. For example, the cross section of the prism may also be trapezoidal or semi-circular; even according to the illumination direction of the light source, the prism may be adjusted accordingly, for example, the first The prisms may be arranged in parallel parallel to the diagonal direction of the light guide plate, and the object of the present invention can be achieved.

The present invention also provides a backlight module assembled by using the above-mentioned light guide plate. As shown in FIG. 3 , the backlight module 50 includes the light guide plate 10 (the prism structure is not shown), and is disposed on the light incident side of the light guide plate 10 . The light source 30, wherein the light emitted from the light source 30 is perpendicular to the light incident side of the light guide plate 10. In this embodiment, the quality of the backlight module can be greatly improved by the improvement of the structure of the light guide plate.

Although the present invention has been particularly shown and described with reference to the exemplary embodiments thereof, those skilled in the art Various changes in form and detail can be made.

Claims

A light guide plate for a backlight module includes a first light incident side and a second light incident side having a width smaller than the first light incident side, wherein the first light incident side and the second light incident side are respectively corresponding The light source is configured to introduce a first incident light and a second incident light, wherein the surface of the light guide plate is arranged with a plurality of first prisms and second prisms having a trapezoidal or triangular or semi-circular cross section; The long axis is perpendicular to the first incident light, and the long axis of the second prism is perpendicular to the second incident light direction; a gap exists between the first prisms and the second prism.
The light guide plate according to claim 1, wherein when the cross section of the first prism and the second prism is a triangle, a vertex angle of the triangle is a right angle.
The light guide plate according to claim 1, wherein an angle between the first light incident side and the second light incident side is a right angle.
The light guide according to claim 1, wherein the second prism is interposed between two rows of first prisms.
A backlight module includes a light guide plate and a light source, the light guide plate includes a first light incident side and a second light incident side having a width smaller than the first light incident side, the first light incident side and the second light input side The light side is respectively introduced with the first incident light and the second incident light by the corresponding light source, wherein the surface of the light guide plate is arranged with a plurality of first prisms and second prisms having a trapezoidal or triangular or semi-circular cross section. The long axis of the first prism is perpendicular to the first incident light, the long axis of the second prism is perpendicular to the direction of the second incident light; and the first prism and the second prism exist gap.
The backlight module of claim 5, wherein when the cross section of the first prism and the second prism is a triangle, the apex angle of the cross section is a right angle.
The backlight module of claim 5, wherein an angle between the first light incident side and the second light incident side is a right angle.
The backlight module of claim 5, wherein the second prism is interposed between the two rows of first prisms.