TW201405216A - Backlight module - Google Patents

Abstract

A backlight module comprises a diffusion board and a diffusion unit formed on a surface of the diffusion board. The diffusion unit comprises a first diffusion structure and a second diffusion structure surrounding the first diffusion structure. The first diffusion structure comprises a light permeable zone that allows light to penetrate and a first light-shielding zone that does not allow light to penetrate. The second diffusion structure comprises a continuous light permeable zone that allows light to penetrate and a second light-shielding zone that is distributed in the continuous light permeable zone and does not allow light to penetrate. The arrangement of the first and second diffusion structures helps enhance light diffusion performance to further improve uniformity of exiting light from backlight module.

Description

Backlight module

The invention relates to a backlight module of a display device, in particular to a backlight module with various microstructure designs.

At present, most of the liquid crystal modules commonly used in flat panel displays are TFT-LCDs. The TFT-LCD is a non-active light-emitting display. It usually provides a system brightness by a backlight module that provides white light, and then obtains a rich color display through a color filter.

The structure of the backlight module generally includes a diffusing plate and a light source, and the light-emitting diode (LED) is gradually becoming a light source used in the backlight module of the liquid crystal display because of its small size and low energy consumption. However, the LED as the light source of the backlight module generally has a plurality of LEDs arranged in a dot matrix arrangement on the surface of the diffusion plate, so that the backlight module is prone to uneven light emission, and the backlight module is improved to improve the shortcoming. The group can provide uniform brightness. Therefore, most of the micro-structures are formed on the light-emitting surface or the light-incident surface of the diffusion plate, or the optical film is further added to the light-emitting surface of the backlight module, or further to the optical film. The microstructure is printed on the chip to improve the unevenness of the light output of the dot matrix LED light source.

However, the foregoing method for forming the microstructure to improve the light uniformity of the backlight module is mainly composed of a plurality of concentric circles, or a plurality of solid circles arranged in a concentric circle, but The light diffusion of the single pattern microstructure makes it easy for the light diffusion effect to be limited by the microstructure and the light uniformity cannot be improved more effectively.

Accordingly, it is an object of the present invention to provide a backlight module for use in a display that utilizes a microstructure to effectively enhance light uniformity.

Therefore, a backlight module of the present invention comprises a light diffusing element and a light source.

The light diffusing element comprises a diffusing plate, and a plurality of diffusing units formed on one surface of the diffusing plate, each of the diffusing units comprising a first diffusing structure and a second diffusing structure, the first diffusing structure having a a light transmissive light transmissive region and a first light-shielding region that is opaque to light, the second diffusion structure surrounding the first diffusion structure, having a transparent light transmissive region and being dispersed in the continuous transparent In the light zone, it is a second light-shielding zone that is not permeable to light.

The light source is disposed adjacent to one surface of the diffuser plate, and light emitted from the light source is uniformly emitted outward through the action of the diffusion units.

The effect of the present invention is that, by using the design of the first and second diffusion structures, when the light emitted from the light source passes through the diffusion plate and contacts the first and second diffusion structures, the diffusion unit can function Efficiently and evenly emitted toward the outside of the diffuser plate to enhance the uniformity of light output of the backlight module.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are Still It is within the scope of the patent of the present invention.

Referring to FIG. 1 and FIG. 2, FIG. 1 is a view showing a preferred embodiment of a liquid crystal display having a backlight module of the present invention, and FIG. 2 is a light diffusing unit for assisting the backlight module of FIG.

The liquid crystal display comprises a liquid crystal display unit 2 and a backlight module 3.

The liquid crystal display unit 2 has a thin film transistor substrate 21, a color filter substrate 22, and a liquid crystal layer 23 interposed between the thin film transistor substrate 21 and the color filter substrate 22. . It should be noted that the liquid crystal display unit 2 can also add polarizers and other optical components (not shown) according to design requirements and structural design. Since the liquid crystal display unit 2 and related optical components are similar in design to general liquid crystal displays, It is known in the art and therefore will not be described again.

The backlight module 3 is disposed on a side of the thin film transistor substrate 21 away from the liquid crystal layer 23, and has a light diffusing element 4 and a light source 5.

The light diffusing element 4 includes a diffusing plate 6 and a plurality of diffusing units 7. The material of the diffusing plate 6 may be selected from PET, PC, PMMA, PS, Acrylic or other organic polymer materials, the light transmittance is between 40 and 80%, the haze is higher than 60%, and the thickness is about 0.5 to 3 mm. A light-emitting surface 61 substantially parallel to the liquid crystal display unit 2, a back surface 62 opposite to the light-emitting surface 61, and four side surfaces 63 respectively connecting the light-emitting surface 61 and the back surface 62 are provided.

The diffusion units 7 are formed by etching, inkjet, attaching or screen printing, and may be arranged in a matrix or staggered on the diffusion plate 6. Preferably, the diffusion units 7 are screen printed or The inkjet method is formed.

Specifically, each of the diffusion units 7 includes a first diffusion structure. 71, and a second diffusion structure 72, and the center position of each of the first diffusion structures 71 is respectively corresponding to some LED die.

The first diffusing structure 71 has a light-transmissive light-transmissive region 711 and a light-impermeable first light-shielding region 712. In this embodiment, the first light-shielding region 712 is a continuous phase, and the light-transmitting region 711 The light-transmitting points are arranged along a plurality of concentric loops to form a plurality of first concentric rings distributed in the first light-shielding region 712, and each of the concentric rings The spacing of the adjacent light-transmitting dots is about the same, that is, the density of the light-transmitting points of each of the first concentric rings is the same. In FIG. 2, the light-transmitting dots are represented by a circle, however, the light-transmitting dots are The shape of the dots is not limited thereto, and may be different geometric shapes such as a triangle, a quadrangle, and a star.

The second diffusion structure 72 surrounds the first diffusion structure 71, and has a light transmissive continuous light transmission area 721 and a second light shielding area 722 dispersed in the continuous light transmission area 721 and being opaque. In this embodiment, the second light-shielding region 722 is formed by a plurality of light-shielding points spaced apart from each other, and the light-shielding points are arranged along a plurality of concentric loop lines to form a plurality of light-distributing regions 721. a concentric ring, and the spacing of adjacent shading points in each of the second concentric rings is substantially the same, that is, the density of the shading points of each of the second concentric rings is the same, as shown in FIG. The shading points are represented by circles. However, the shape of the shading points is not limited thereto, and may be different geometric shapes such as a triangle, a quadrangle, and a star.

The light source 5 is disposed on one of the surfaces adjacent to the diffusing plate 6, and the light emitted from the light source 5 is uniformly emitted outward through the action of the diffusing units 7.

It should be noted that when the backlight module 3 is a direct type backlight, the light source 5 is disposed at a position close to the back surface 62; and when the light source 5 is disposed on the back surface 62 of the diffusion plate 6, the The diffusion unit 7 may be disposed on one side of the light-emitting surface 61 or the back surface 62, or may be disposed on the light-emitting surface 61 and the back surface 62 at the same time, and when the diffusion unit 7 is disposed on the light-emitting surface 61 or the back surface When one side of the 62 is used, the other side can be further equipped with a light diffusing member commonly used in the industry, such as a flat diffusing plate or a diffusing plate having a 稜鏡 structure on the surface, and the effect of optimizing light diffusion can also be achieved.

In the preferred embodiment, the backlight module 3 is a direct-type backlight. The light source 5 has a plurality of LED dies disposed in an array adjacent to the back surface 62. The diffusion units 7 are disposed on the back surface 62. And the centers of the diffusion units 7 respectively correspond to the illuminating centers of the LED dies. It is worth mentioning that the LED dies may further have secondary optical components (not shown) corresponding to the light-emitting surfaces of the LED dies, and the secondary optical components may be used for the LED crystals. The light emitted by the particles produces a diffusing effect and reduces the amount of LED crystal grains.

By using the first and second diffusion structures 71 and 72, the light emitted from the LED dies can be connected to the structures of the diffusion units 7 by the first and second diffusions 71 and 72. The function is effectively and uniformly diffused, and is emitted outward toward the light-emitting surface 61 to improve the light uniformity of the backlight module.

It is worth mentioning that the distribution density of the light-transmitting points and the light-shielding points is generally set according to the illuminance distribution of the light source 5, and the first and second diffusion junctions are The distribution density of the structures 71, 72 near the center of the light source 5 is relatively large and is distributed toward the density away from the light element 5, so that a better light diffusion uniform effect can be obtained; preferably, close to the The light transmission point and the light shielding point of the center of the first and second diffusion structures 71 and 72 have a density ranging from 0.4 to 1.0, away from the light transmission point and the light shielding point of the center of the first and second diffusion structures 71 and 72. The density ranges from greater than zero and less than or equal to 0.6.

In addition, referring to FIG. 3 to FIG. 5 , the light-transmitting points in the two adjacent first concentric rings in each of the first diffusion structures 71 and the second diffusion structure 72 in each of the first diffusion structures 71 are illustrated. The density of the light-shielding points in any two adjacent second concentric rings may be adjusted to different density distribution patterns, or the light transmission points and the light-shielding points may be adjusted in size, for example, The density of the light-shielding points located in the different second concentric rings is adjusted to be increased or decreased outwardly from the center of the structures of the second concentric rings, or the light-transmitting points of the first and second concentric rings are adjusted. And the size of the light-shielding point, such that the distance between the light-transmitting point and the light-shielding point has different density distribution due to the change of the size, or the size of the light-shielding point and the light-transmitting point can be determined by the first The center of the structure of the two concentric rings is outwardly incremented or decremented, so that the light-shielding points and the light-transmitting points form different density and different distribution shapes, such as triangular, rectangular, etc., to achieve an uneven structure distribution. And the diffusion unit 7 can have The light diffusion effect is good; that is, by adjusting the density and the shape of the light-shielding points and the light-shielding points, the diffusion units 7 can be formed with different dot density and different distribution shapes to achieve the Set the diffusion effect.

Referring to FIG. 6, in addition, the light-transmitting points constituting the light-transmitting region 711 can also be The light-transmitting regions 711 are connected to each other to form a plurality of light-transmitting rings in a concentric annular shape and distributed in the first light-shielding region 712.

In summary, the present invention is designed by using the first and second diffusion structures 71 and 72 of two different distribution types, and different diffusion effects are caused by different structures. Therefore, the backlight module 3 of the present invention can be achieved. Compared with the conventional backlight module having a single light diffusion microstructure, the light distribution uniformity can be improved by controlling the distribution pattern and distribution density of the light transmission points and the light shielding points. The backlight module 3 is provided with better light uniformity, so that the object of the present invention can be achieved.

2‧‧‧LCD unit

21‧‧‧Film Optoelectronic Substrate

22‧‧‧Color filter substrate

23‧‧‧Liquid layer

3‧‧‧Backlight module

4‧‧‧Light diffusing elements

5‧‧‧Light source

6‧‧‧Diffuser

61‧‧‧Glossy

62‧‧‧Back

63‧‧‧ side

7‧‧‧Diffusion unit

71‧‧‧First diffusion structure

711‧‧‧Light transmission area

712‧‧‧ first shade

72‧‧‧Second diffusion structure

721‧‧‧Continuous light transmission area

722‧‧‧second shade

1 is a schematic view showing a liquid crystal display having a backlight module according to a preferred embodiment of the present invention; FIG. 2 is a schematic view for explaining the light diffusing unit of the backlight module in FIG. 1; FIG. Another aspect of the distribution of the first and second diffusion structures is illustrated; FIG. 4 is a schematic diagram for explaining another aspect of the distribution of the first and second diffusion structures; FIG. 5 is a schematic diagram for explaining the first and second A further aspect of the distribution of the diffusion structure; and Figure 6 is a schematic diagram illustrating another aspect of the first diffusion structure.

61‧‧‧Glossy

62‧‧‧Back

7‧‧‧Diffusion unit

71‧‧‧First diffusion structure

711‧‧‧Light transmission area

712‧‧‧ first shade

72‧‧‧Second diffusion structure

721‧‧‧Continuous light transmission area

722‧‧‧second shade

Claims (15)

A backlight module for a display, comprising: a light diffusing element having a diffusing plate and a plurality of diffusing units, the diffusing plate having a light emitting surface and a back surface opposite to the light emitting surface, a diffusion unit is formed on at least one of the light-emitting surface and the light-emitting surface, each of the diffusion units includes a first diffusion structure, a light-transmissive light-transmissive region, and a first light-shielding region that is opaque to light, and a second diffusion structure surrounding the first diffusion structure, having a transparent light transmissive region and a second light shielding region dispersed in the continuous light transmission region and being opaque; and a light source, The light source is disposed adjacent to one of the surfaces of the diffuser plate, and light emitted from the light source is uniformly emitted outward through the action of the diffusion units. The backlight module of claim 1, wherein the light source has a plurality of LED dies arranged in an array, and the centers of the diffusion units are disposed corresponding to the illuminating centers of the LED dies. The backlight module of claim 2, wherein the LED dies further have secondary optical elements corresponding to the light emitting surfaces of the LED dies. The backlight module of claim 1, wherein the diffusion units are formed on the light-emitting surface and the back surface at the same time. The backlight module of claim 1, further comprising a light diffusing member, wherein the diffusing units are formed on a light emitting surface of the diffusing plate or any one of the back surfaces, and the light diffusing member is disposed on the light diffusing member Diffuser plate The other side of the diffusion unit is opposite. The backlight module of claim 1, wherein the diffusion units are formed by etching, inkjet, attaching or screen printing. The backlight module of claim 1, wherein the first light-shielding region is a continuous phase, and the light-transmitting region is formed by a plurality of light-transmitting dots spaced apart from each other, and the light-transmitting dots are It is a geometric shape such as a circle, a triangle, a quadrangle, or a star. The backlight module of claim 7, wherein the light-transmitting points are arranged along a concentric loop and are a plurality of first concentric rings distributed in the first light-shielding region and spaced apart from each other. The backlight module of claim 8, wherein the density of the light-transmitting points in any two adjacent first concentric rings may be the same or different. The backlight module of claim 8, wherein the density of the light-transmitting points of the first concentric rings is increased or decreased outward from the center of the structures of the first concentric rings. The backlight module of claim 1, wherein the second light-shielding region is formed by a plurality of light-shielding points spaced apart from each other, and the light-shielding points may be circular, triangular, quadrangular, and star-shaped. Equal geometric shapes. The backlight module of claim 11, wherein the light-shielding points are arranged along a concentric loop and are a plurality of second concentric rings distributed in the light-transmitting region and spaced apart from each other. According to the backlight module of claim 12, wherein the phase is The density of the light-shielding points in the two adjacent second concentric rings may be the same or different. The backlight module of claim 12, wherein the density of the light-shielding points of the second concentric rings is increased or decreased outward from the center of the structure of the second concentric rings. The backlight module of claim 1, wherein the light-transmitting region has a plurality of light-transmitting rings distributed in a concentric annular shape in the first light-shielding region.