CN101749645B - Diffusion plate with star-shaped diffusion structure and backlight module using same - Google Patents

Abstract

The invention discloses a diffusion plate used for a backlight module. The diffusion plate comprises a substrate, a plurality of circular diffusion structures and at least one starburst-shaped diffusion structure. The circular diffusion structures are formed on one surface of the substrate in a matrix distribution mode, each circular diffusion structure comprises a plurality of first partial reflection units, the first partial reflection units are arranged on the substrate in a circular distribution mode, and outer arcs of adjacent circular diffusion structures are tangent and jointly enclose a starburst area. The at least one starburst diffusion structure comprises a plurality of second partial reflection units, and the second partial reflection units are formed on one surface of the substrate and distributed in the starburst area in a starburst shape.

Description

Diffusion plate with star-shaped diffusion structure and backlight module using same

technical field

The present invention relates to a diffusion plate; specifically, the present invention relates to a diffusion plate used in a liquid crystal display backlight module.

Background technique

In recent years, liquid crystal displays (Liquid Crystal Displays) have become the mainstream of various display devices. For example, household televisions, personal computers, laptop computers, monitors, mobile phones, and digital cameras are all products that use liquid crystal display devices in large quantities. Wherein, the backlight module (Backlight Module) applied to the liquid crystal display device is used to supply the liquid crystal with sufficient brightness and evenly distributed light source, so that the liquid crystal display device can display images normally.

As shown in FIG. 1 , a conventional direct type backlight module 90 includes a light source module 200 and an optical film set 80 . Wherein, the optical film set 80 includes a first diffuser plate 81 and a second diffuser plate 82 , which belong to a double plate structure, and the first diffuser plate 81 and the second diffuser plate 82 are respectively provided with single-sided printed microstructures. On the other hand, light emitting diodes (Light Emitting Diodes, LED) have become one of the light sources used in LCD backlight modules due to their small size and low energy consumption. However, for the direct-lit backlight module using a double-plate structure, if light-emitting diodes are used as light sources, uneven light output is likely to occur even with the double-plate structure. At the same time, in order to maintain a certain degree of uniformity, it is necessary to use a double-plate structure or more optical films, resulting in an increase in the thickness and cost of the backlight module. In addition, the number of light-emitting diodes used in direct-type backlight modules in display devices such as televisions is often no less than a few hundred. Therefore, the price of light-emitting diodes often accounts for a relatively high cost of direct-type backlight modules.

Contents of the invention

The main purpose of the present invention is to provide a diffusion plate for use in a backlight module, which can improve the light uniformity of the backlight module.

Another object of the present invention is to provide a diffusion plate for use in a backlight module, which can reduce the manufacturing cost of the backlight module.

Another object of the present invention is to provide a backlight module with better light uniformity.

Another object of the present invention is to provide a backlight module with lower manufacturing cost.

The diffusion plate of the present invention includes a substrate, a plurality of circular diffusion structures and at least one star-shaped diffusion structure. A plurality of circular diffusion structures are formed on one side of the substrate in a matrix distribution manner, each circular diffusion structure includes a plurality of first partial reflection units, and the first partial reflection units are arranged on the substrate in a circular distribution manner, adjacent circles The outer arcs of the diffuse structure are tangent and together form a star-shaped area. At least one star-shaped diffusion structure includes a plurality of second partial reflection units formed on one side of the substrate and distributed in the star-shaped region in a star-shaped manner.

The substrate has a boundary, and the adjacent circular diffusion structures arranged along the boundary and the boundary together form a star-shaped region. The plurality of first partial reflection units of each circular diffusion structure are formed as a plurality of concentric circular lines outside the center of the circular diffusion structure, and are distributed outwards in a circle with the center of the circular diffusion structure as the center. The multiple first partial reflection units of each circular diffusion structure are formed as a solid circle pattern at the center of the circular diffusion structure.

A plurality of concentric circular lines are located at and outside the center of the plurality of first partial reflection units of each circular diffusion structure. The line width of the concentric circular lines decreases as the distance from the center of the circular diffusion structure increases. The distance between the concentric circular lines increases as the distance from the center of the circular diffusion structure increases. Each concentric circle consists of several paragraphs, with gaps between the paragraphs.

The second partial reflection unit is a plurality of concentric starburst lines, wherein each starburst line is composed of polygonal lines, and the sidelines are concentric arcs of adjacent circular diffusion structures. The line width of the star-shaped lines increases with the distance from the center of the star-shaped diffusion structure. The pitch of the star-shaped lines decreases with increasing distance from the center of the star-shaped diffusion structure.

The first part of the reflection unit is a solid circle pattern, and is distributed outwards into a plurality of concentric circular lines around the center of the circular diffusion structure. The diameter of the first partial reflection unit decreases gradually as the distance from the center of the circular diffusion structure increases. The distance between the concentric circular lines increases as the distance from the center of the circular diffusion structure increases.

The second partial reflection unit is formed in a dot pattern and distributed into a plurality of concentric starburst lines. Each star-shaped line is composed of polygonal lines, which are concentric arcs of adjacent circular diffusion structures. The diameter of the second partially reflecting unit increases with the distance from the center of the star-shaped diffusion structure. The pitch of the star-shaped lines decreases with increasing distance from the center of the star-shaped diffusion structure.

The diffusion plate further has an opposite diffusion unit, which is arranged on the other side of the substrate and is a mirror image of the circular diffusion unit and the star-shaped diffusion unit. The diffusion plate further has an opposite side diffusion unit covering the other side of the substrate. The circular diffusion structures are formed on one side of the substrate in the form of a square matrix distribution, and the outer arcs of the four adjacent circular diffusion structures are tangent and together form a star-shaped area. The circular diffusion structures are formed on one side of the substrate in a triangular matrix distribution manner, and the outer arcs of the three adjacent circular diffusion structures are tangent to each other and together form a star-shaped area. The backlight module of the present invention includes a light source module and the aforementioned diffusion plate. The light source module has a plurality of light source units.

Description of drawings

Fig. 1 is a schematic diagram of known technology;

2A is a schematic diagram of the explosion of the backlight module of the present invention;

Figure 2B is a schematic side view of the present invention;

3A1 and 3A2 are schematic diagrams of preferred embodiments of the present invention;

3B to 5B are schematic diagrams of different embodiments of the present invention;

6A and 6B are schematic diagrams of a preferred embodiment of the present invention with diffusion units on opposite sides.

Description of main component symbols:

100 substrates 200 light source modules

210 light source unit 300 circular diffusion structure

400 partial reflective unit 410 first partial reflective unit

420 second part reflection unit 421 concentric arc

422 concentric arcs 423 concentric arcs

424 concentric arc 480 opposite side diffusion unit

500 star-shaped diffusion structure 600 rays

700 Astral Area 710 Astral Area

800 diffusion plate 900 backlight module

Detailed ways

As shown in FIG. 2A , the exploded view of the backlight module, in a preferred embodiment, the diffusion plate 800 of the present invention can be used in the backlight module 900 . Specifically, the backlight module 900 includes a light source module 200 and a diffusion plate 800 . The light source module 200 has a plurality of light source units 210, wherein the light source units 210 include light emitting diodes. As shown in FIG. 2B , a schematic side view of the backlight module, the diffusion plate 800 of the present invention is composed of the substrate 100 and the partial reflection units 400 distributed on the surface of the substrate 100, although FIG. 2B only illustrates that the partial reflection units 400 are arranged on the substrate The lower surface of the substrate 100 , but not limited thereto, the reflective unit 400 may also be disposed on the upper surface of the substrate 100 . When the light 600 emitted by the light source unit 210 touches the partial reflection unit 400 , partial refraction and partial reflection will occur, thereby producing a diffusion effect and improving the uniformity of the backlight module. On the other hand, compared with the conventional double-plate structure, the diffuser plate 800 of the present invention uses a single-plate structure, that is, part of the reflective unit 400 is formed on at least one surface of the substrate 100 , which can reduce module thickness and cost. Wherein, the reflectivity of the diffusion plate 800 can be between 25% and 100%, preferably between 25% and 80%. As the brightness of the light source unit 210 increases, the reflectivity of the diffusion plate 800 can be designed higher. The reflectivity of the plate 800 can be determined by adjusting the configuration density/coverage ratio of the reflective unit 400 (as described below in detail) or selecting an appropriate material of the reflective unit 400 . The manufacturing process for forming the partial reflection unit 400 is preferably but not limited to screen printing, and may also be sputtering or jet printing.

The structure of the diffuser plate 800 of the present invention will be further described below. In a preferred embodiment shown in FIG. 3A1 and FIG. 3A2 , the diffusion plate 800 of the present invention includes a substrate 100 , a plurality of circular diffusion structures 300 and at least one star-shaped diffusion structure 500 . The substrate 100 can be a transparent plate or a plate containing diffused particles. A plurality of circular diffusion structures 300 are formed on one side of the substrate 100 in a matrix distribution manner. In a preferred embodiment, the circular diffusion structures 300 are formed on one side of the substrate 100 in a square matrix distribution manner as shown in FIG. 3A1 and FIG. Together they form a four-pointed star-shaped region 700 . However, in different embodiments, the circular diffusion structures 300 may be formed on one side of the substrate 100 in a triangular matrix distribution manner, and the outer arcs of the three adjacent circular diffusion structures 300 are tangent and together form a three-pointed star-shaped region. .

Each circular diffusion structure includes a plurality of first partial reflection units 410, and the first partial reflection units 410 are disposed on the substrate 100 in a circular or concentric distribution manner, and the outer arcs of adjacent circular diffusion structures 300 are tangent to each other. And they together form a star-shaped area 700. At least one star-shaped diffusion structure 500 includes a plurality of second partial reflection units 420 formed on one side of the substrate 100 and distributed in the star-shaped region 700 in a star-shaped manner. Wherein, the first partial reflection unit 410 and the second partial reflection unit 420 jointly constitute the partial reflection unit 400 shown in FIG. 2B . The thickness of the partial reflection unit 400 is preferably between 1 nm and 1 mm. Among them, when the thickness range is in the micron range, the material is preferably barium carbonate (BaCO ₃ ) or barium sulfate (BaSO ₄ ); when the thickness range is in the nanometer range, the material is preferably tantalum pentoxide (Ta2O ₅ ), silicon dioxide (SiO ₂ ) and other thin film materials.

As shown in FIG. 3A1 and FIG. 3A2 , the second partial reflection unit 420 is a plurality of concentric star-shaped lines, wherein each star-shaped line is composed of polygonal lines, and the side lines are concentric arcs of adjacent circular diffusion structures 300 . Specifically, the outermost starburst line of the second partial reflection unit 420 is formed by the concentric arcs 421, 422, 423 and 424 that are closest to the four adjacent circular diffusion structures 300 respectively, wherein the concentric arcs 421 is concentric with the upper left circular diffusion structure 300, the concentric arc 422 is concentric with the upper right circular diffusion structure 300, the concentric arc 423 is concentric with the lower right circular diffusion structure 300, and the concentric arc 424 is concentric with the lower left circular diffusion structure The structure is 300 concentric. By analogy, the other star-shaped lines of the second part of the reflection unit 420 are composed in a similar manner. The center of each circular diffusion structure 300 preferably corresponds to a light source unit 210 (see FIG. 2B ). Specifically, the center of each circular diffusion structure 300 is preferably disposed above a light source unit 210 .

As shown in FIG. 3A1 and FIG. 3A2 , viewed in different ways, on the surface of the substrate 100, a plurality of points distributed in a matrix are used as the centers of circles, and partial reflection units are arranged outwards from the center of the circle in a manner of circular distribution, and the partial reflection units would intersect and enclose a star-shaped region 700 . The partial reflection units outside the star-shaped region are the first partial reflection units 410 , and the partial reflection units inside the star-shaped region are the second partial reflection units 420 . On the other hand, the substrate 100 has a boundary, and the adjacent circular diffusion structures 300 disposed along the boundary can form a star-shaped region 710 together with the boundary.

As shown in Fig. 3A1 and Fig. 3A2, in a preferred embodiment, the plurality of first partial reflection units 410 of each circular diffusion structure 300 are a plurality of concentric circular lines outside the center of the circular diffusion structure 300, and the circles The center of the diffuser structure 300 is distributed outwards in a circle. However, in a different embodiment as shown in FIG. 3B , the plurality of first partial reflection units 410 of each circular diffusion structure 300 are formed as a solid circle pattern at the center of the circular diffusion structure 300 . Specifically, in the preferred embodiment shown in FIG. 3A1 and FIG. 3A2 , the center of the circular diffusion structure 300 is a circular line pattern, which is a hollow ring shape, and the light source unit 210 (see FIG. 2B ) emits toward the Part of the light directly above can directly pass through the diffusion plate 800 without being partially reflected by the first partial reflection unit 410 . In different embodiments shown in FIG. 3B , the center of the circular diffusion structure 300 is a solid circle pattern, and the light emitted by the light source unit 210 is directed upward, and passes through the first part of the reflection unit 410 when passing through the diffusion plate 800 . In other words, the pattern coverage ratio of the center of the circular diffuser structure 300 can be used to control the amount of light emitted from the light source unit 210 directed upward and directly passing through the diffuser plate 800 without being partially reflected by the first partial reflection unit 410 .

In the embodiment shown in FIG. 3A1, FIG. 3A2 and FIG. 3B, outside the centers of the plurality of first partial reflection units 410 of each circular diffusion structure 300 are a plurality of concentric circular lines, and the line width of the concentric circular lines varies with The distance between the center of the circular diffusion structure 300 increases and decreases. In other words, the coverage ratio of the circular diffusion structure 300 can be controlled by adjusting the line width of the concentric circles of the first partial reflection unit 410 . Wherein, the line width of the star-shaped line serving as the second part of the reflection unit 420 also decreases gradually as the distance from the center of the adjacent circular diffusion structure 300 increases, and also decreases with the distance from the center of the star-shaped diffusion structure. increase and increase.

In different embodiments, the coverage ratio of the circular diffusion structure 300 can also be controlled by adjusting the distance between the concentric circles of the first partial reflection unit 410 . That is, the line width of the concentric circles of the first partial reflection unit 410 can be fixed, and then the spacing of the concentric circles of the first partial reflection unit 410 can be adjusted. The smaller the spacing, the higher the coverage of the first partial reflection unit 410 in the unit area. In different embodiments as shown in FIG. 3C , the distance between the concentric circular lines increases as the distance from the center of the circular diffusion structure 300 increases. Wherein, the spacing of the star-shaped lines serving as the second part of the reflection unit 420 also increases gradually with the distance from the center of the adjacent circular diffusion structure 300, that is, with the distance from the center of the star-shaped diffusion structure increase and decrease.

In the embodiment shown in FIG. 3A1 and FIGS. 3A2 to 3C , each concentric circular line of the circular diffusion structure 300 is a continuous solid line. However, in different embodiments, the visual design requirements of the concentric circular lines are constituted by paragraphs or dots. In the embodiment shown in FIG. 4 , each concentric circular line is composed of multiple segments with gaps between the segments. In the embodiment shown in FIG. 5A and FIG. 5B , the first partial reflection unit 410 is a solid circle pattern, and the center of the circular diffusion structure 300 is distributed outwards to form a plurality of concentric circular lines. In other words, in the embodiment shown in FIG. 5A and FIG. 5B , the first partial reflection units 410 are solid circles distributed as concentric circles. Correspondingly, the second partial reflection unit 420 is also formed in a dot pattern, and is distributed into a plurality of concentric starburst lines. Wherein, as shown in FIG. 5A , the diameter of the first partial reflection unit 410 may decrease gradually as the distance from the center of the circular diffusion structure 300 increases. The diameter of the second partial reflection unit 420 decreases as the distance from the center of the adjacent circular diffusion structure 300 increases, that is, the diameter of the second partial reflection unit 420 increases as the distance from the center of the star-shaped diffusion structure increases. On the other hand, in the embodiment shown in FIG. 5B , the distance between the concentric circular lines increases as the distance from the center of the circular diffusion structure 300 increases. The distance between the star-shaped lines increases with the increase of the distance from the center of the adjacent circular diffusion structure 300 , that is, it decreases with the increase of the distance from the center of the star-shaped diffusion structure.

As shown in FIG. 6A and FIG. 6B , in a preferred embodiment, the diffusion plate 800 further has an opposite diffusion unit 480 disposed on the other side of the substrate 100 for further increasing the partial reflection effect on the light 600 . Wherein, the reflectivity of the diffusion plate 800 can be between 25% and 100%, preferably between 25% and 80%. As the brightness of the light source unit 210 increases, the reflectivity of the diffusion plate 800 can be set higher. The thickness of the opposite diffusion unit 480 is preferably between 1 nm and 1 mm. Among them, when the thickness range is in the micron range, the material is preferably barium carbonate (BaCO ₃ ) or barium sulfate (BaSO ₄ ); when the thickness range is in the nanometer range, the material is preferably tantalum pentoxide (Ta2O ₅ ), silicon dioxide (SiO ₂ ) and other thin film materials. In the embodiment shown in FIG. 6A , the opposite diffusion unit 480 covers the other side of the substrate 100 . In the embodiment shown in FIG. 6B , the opposite diffusion unit 480 disposed on the other side of the substrate 100 is combined with the circular diffusion unit (see FIGS. 3A1 and 3A2 ) and the star-shaped diffusion unit (see FIG. 3A1 ). and Figure 3A2) are mirror images of each other. Wherein, the circular diffusion unit and the star-shaped diffusion unit together constitute the partial reflection unit 400 shown in FIG. 6B . As shown in FIG. 6A and FIG. 6B , when the light 600 emitted by the light source unit 210 travels to the partial reflection unit 400 , a partial reflection occurs, and when it travels to the opposite diffusion unit 480 , another partial reflection occurs. Specifically, through the repeated partial reflection of the light 600 by the partial reflection unit 400 and the opposite side diffusion unit 480, the light 600 can have a wider distribution than the above-mentioned embodiment in FIG. The number of light source units 210 used further reduces energy consumption and manufacturing costs.

Although the foregoing description and accompanying drawings have disclosed preferred embodiments of the present invention, it must be understood that various additions, modifications and substitutions may be applied to the preferred embodiments of the present invention without departing from the scope of the appended application. spirit and scope of the principles of the invention. Those of ordinary skill in the art to which the invention pertains will appreciate that the invention can be employed with many modifications in form, structure, arrangement, proportion, material, element and assembly. Therefore, the embodiments disclosed herein should be regarded as illustrating the present invention rather than limiting the present invention. The scope of the present invention should be defined by the claims of the appended claims and cover their legal equivalents, not limited by the foregoing description.

Claims (24)

1. A diffusion plate, used for a backlight module, is characterized in that, the diffusion plate comprises: a substrate; A plurality of circular diffusion structures are formed on one side of the substrate in a matrix distribution manner, each circular diffusion structure includes a plurality of first partial reflection units, and the first partial reflection units are arranged in a circular distribution manner on the On the substrate, the outer arcs of the adjacent circular diffusion structures are tangent and together form a star-shaped area; and At least one star-shaped diffusion structure, including a plurality of second partial reflection units, the second partial reflection units are formed on the surface of the substrate and distributed in the star-shaped region in a star-shaped manner Inside. 2. The diffuser plate according to claim 1, wherein the substrate has a boundary, and the adjacent circular diffusion structures arranged along the boundary form the boundary together with the boundary. the star-shaped region described above. 3. The diffusion plate according to claim 1, wherein the plurality of first partial reflection units of each circular diffusion structure are a plurality of concentric circular lines outside the center of the circular diffusion structure, and The center of the circular diffusion structure is distributed outwards in a circle. 4. The diffuser plate as claimed in claim 3, wherein the plurality of first partial reflection units of each circular diffuser structure are formed as a solid circle pattern at the center of the circular diffuser structure. 5 . The diffusion plate as claimed in claim 3 , wherein a plurality of concentric circular lines are located at and outside the center of the plurality of first partial reflection units of each circular diffusion structure. 5 . 6 . The diffuser plate according to claim 3 , wherein the line width of the concentric circular lines decreases gradually as the distance from the center of the circular diffuser structure increases. 6 . 7. The diffuser plate according to claim 3, wherein the distance between said concentric circles increases gradually with the increase of the distance from the center of said circular diffuser structure. 8. The diffuser plate as claimed in claim 3, wherein each concentric circular line is composed of a plurality of segments, and the segments have gaps between each other. 9. The diffuser plate according to claim 3, wherein said second partial reflection unit is a plurality of concentric star-shaped lines, wherein each said star-shaped line is composed of polygonal lines , the sidelines are concentric arcs of adjacent circular diffusion structures. 10 . The diffuser plate according to claim 9 , wherein the width of the star-shaped lines increases gradually as the distance from the center of the star-shaped diffuser structure increases. 11 . 11. The diffuser plate as claimed in claim 9, wherein the pitch of said star-shaped lines decreases gradually as the distance from the center of said star-shaped diffuser structure increases. 12. The diffusion plate according to claim 1, wherein the first part of the reflection unit is a solid circle pattern, and is distributed outwards into a plurality of concentric circles with the center of the circular diffusion structure as the center lines, the concentric circular lines are distributed by the first reflection unit. 13. The diffusion plate according to claim 12, wherein the diameter of the first partial reflection unit decreases gradually as the distance from the center of the circular diffusion structure increases. 14. The diffuser plate according to claim 12, wherein the distance between said concentric circles increases gradually as the distance from the center of said circular diffuser structure increases. 15. The diffuser plate according to claim 12, wherein the second part of the reflection unit is formed as a solid circle pattern and distributed as a plurality of concentric star-shaped lines, wherein each of the The star-shaped lines consist of polygonal lines which are concentric arcs of adjacent circular diffusion structures. 16. The diffuser plate as claimed in claim 15, wherein the diameter of the second partial reflection unit increases gradually with the distance from the center of the star-shaped diffuser structure. 17. The diffuser plate as claimed in claim 15, wherein the pitch of said star-shaped lines decreases with increasing distance from the center of said star-shaped diffuser structure. 18. The diffuser plate according to claim 1, characterized in that, the diffuser plate further has a pair of side diffuser units, which are arranged on the other side of the substrate, and are connected to the circular diffuser unit and the The star-shaped diffusion units described above are mirror images of each other. 19. The diffusion plate according to claim 1, wherein the diffusion plate further has a pair of side diffusion units covering the other side of the substrate. 20. The diffusion plate according to claim 1, wherein the circular diffusion structures are formed on the surface of the substrate in a square matrix distribution manner, and four adjacent circular structures The outer arcs of the diffusion structure are tangent and together form the star-shaped region. 21. The diffusion plate according to claim 1, wherein the circular diffusion structure is formed on the surface of the substrate in a triangular matrix distribution manner, and three adjacent circular structures The outer arcs of the diffusion structure are tangent and together form the star-shaped region. 22. The diffuser as claimed in claim 1, wherein the reflectance of the diffuser is between 25% and 100%. 23. The diffuser as claimed in claim 22, wherein the reflectance of the diffuser is between 25% and 80%. 24. A backlight module, characterized in that the backlight module comprises: A light source module having a plurality of light source units; and A diffuser plate, comprising: a substrate, arranged on one side of the light source module; A plurality of circular diffusion structures are formed on one side of the substrate in a matrix distribution manner, and the center of each circular diffusion structure is located directly above one of the light source units, and each circular diffusion structure includes A plurality of first partial reflection units, the first partial reflection units are arranged on the substrate in a circular distribution manner, and the outer arcs of the adjacent circular diffusion structures are tangent and together form a star awn-shaped area; and At least one star-shaped diffusion structure, including a plurality of second partial reflection units, the second partial reflection units are formed on the surface of the substrate and distributed in the star-shaped distribution in the star-shaped within the area.

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