阅读说明：本技术 扩散板、直下式背光模块及显示装置 (Diffusion plate, direct type backlight module and display device ) 是由 施易利 廖启声 蔡丰全 于 2018-08-07 设计创作，主要内容包括：一种扩散板,包括基板、第一图案层以及第二图案层。第一图案层包括多个点状图案,分布于基板上。第二图案层与第一图案层配置于基板的同一侧,并与第一图案层有局部重叠。第二图案层包括多个遮光图案,每一遮光图案包括由内而外分布的多个遮光环,遮光环之间形成多个环状间隙。本发明另提出一种使用此扩散板的直下式背光模块及一种使用此扩散板的显示装置。(A diffusion plate comprises a substrate, a first pattern layer and a second pattern layer. The first pattern layer comprises a plurality of dot patterns distributed on the substrate. The second pattern layer and the first pattern layer are arranged on the same side of the substrate and are partially overlapped with the first pattern layer. The second pattern layer comprises a plurality of shading patterns, each shading pattern comprises a plurality of shading rings distributed from inside to outside, and a plurality of annular gaps are formed between the shading rings. The invention also provides a direct type backlight module using the diffusion plate and a display device using the diffusion plate.)

1. A diffusion plate suitable for direct type backlight module comprises a substrate, a first pattern layer and a second pattern layer,

the first pattern layer comprises a plurality of dot patterns distributed on the substrate;

the second pattern layer and the first pattern layer are arranged on the same side of the substrate and are partially overlapped with the first pattern layer, the second pattern layer comprises a plurality of shading patterns, each shading pattern comprises a plurality of shading rings distributed from inside to outside, and a plurality of annular gaps are formed among the shading rings.

2. The diffuser plate of claim 1, wherein the material of the first patterned layer comprises white ink and the material of the second patterned layer comprises black ink.

3. The diffuser plate according to claim 2, wherein the material of the second pattern layer further comprises a blue ink, the blue ink being mixed with the black ink.

4. The diffuser plate according to claim 1, wherein the first patterned layer has a thickness of between 10 and 200 microns.

5. The diffuser plate of claim 1 wherein the thickness of the first patterned layer is greater than or equal to the thickness of the second patterned layer.

6. The diffuser plate of claim 1, wherein the shape of the plurality of light-shielding rings comprises a circle, an ellipse, or a polygon.

7. The diffuser plate of claim 1, wherein the first patterned layer is between the substrate and the second patterned layer or the second patterned layer is between the substrate and the first patterned layer at an overlap of the first patterned layer and the second patterned layer.

8. A direct type backlight module is characterized in that the direct type backlight comprises a plurality of light emitting elements and a diffusion plate,

the diffusion plate is arranged above the plurality of light-emitting elements and comprises a substrate, a first pattern layer and a second pattern layer,

the first pattern layer comprises a plurality of dot patterns distributed on the substrate;

the second pattern layer and the first pattern layer are arranged on the same side of the substrate and are partially overlapped with the first pattern layer, the second pattern layer comprises a plurality of shading patterns, each shading pattern comprises a plurality of shading rings distributed from inside to outside, and a plurality of annular gaps are formed among the shading rings.

9. The direct type backlight module according to claim 8, wherein the distribution density of the dot patterns is dense at a position closer to the orthographic projection of the light emitting elements on the substrate.

10. The direct type backlight module according to claim 8, wherein the dot patterns have a larger size at a position closer to an orthographic projection of the light emitting elements on the substrate.

11. The direct type backlight module according to claim 8, wherein the plurality of light blocking patterns are disposed with respect to the plurality of light emitting elements, respectively.

12. The direct type backlight module according to claim 8, wherein the substrate has an incident surface and an emergent surface opposite to each other, the incident surface faces the light emitting devices, and the first pattern layer and the second pattern layer are disposed on the incident surface or the emergent surface.

13. The direct type backlight module according to claim 8, wherein each of the plurality of light emitting elements has a top surface facing the diffuser plate and a plurality of side surfaces connected to the top surface, the plurality of side surfaces being light emitting surfaces.

14. The direct type backlight module according to claim 13, wherein the top surface is also a light emitting surface.

15. A display device comprises a display panel and a direct-type backlight module,

the direct type backlight module is arranged opposite to the display panel, the direct type backlight module comprises a plurality of light emitting elements and a diffusion plate, the diffusion plate is arranged between the plurality of light emitting elements and the display panel, the diffusion plate comprises a substrate, a first pattern layer and a second pattern layer, wherein,

the first pattern layer comprises a plurality of dot patterns distributed on the substrate;

the second pattern layer and the first pattern layer are arranged on the same side of the substrate and are partially overlapped with the first pattern layer, the second pattern layer comprises a plurality of shading patterns, each shading pattern comprises a plurality of shading rings distributed from inside to outside, and a plurality of annular gaps are formed among the shading rings.

Technical Field

The present invention relates to an optical plate, and more particularly, to a diffusion plate, and a direct-type backlight module and a display device having the same.

Background

The liquid crystal display panel does not emit light, so a surface light source needs to be provided by the backlight module. In a conventional direct-type backlight module, a plurality of light emitting diodes arranged in a two-dimensional array are disposed below a diffusion plate, and light emitted from the light emitting diodes passes through the diffusion plate to form a surface light source. In order to obtain a surface light source with better uniformity, a proper light mixing distance is required between the light emitting diodes and the diffusion plate, and the larger the distance between two adjacent light emitting diodes, the larger the light mixing distance is often required. In the prior art, in order to obtain a surface light source with better uniformity, the ratio of the distance between two adjacent light emitting diodes divided by the light mixing distance is usually between 1 and 1.1.

In consideration of energy saving design, the number of the light emitting diodes is generally reduced, so the distance between adjacent light emitting diodes is increased, and thus the light mixing distance is also increased, otherwise the problem of poor uniformity of the surface light source is caused. However, the increase of the light mixing distance will make the whole thickness of the direct type backlight module thicker, resulting in a decrease of product competitiveness.

The background section is provided to aid in understanding the present disclosure, and thus, it is intended that all matter contained in the background section or disclosed herein may include other material which does not constitute prior art to the skilled artisan. Furthermore, the statements made in the "background" section do not represent that which is or is to be read as being known or that is known by those skilled in the art before the present application or the problems that may be solved by one or more embodiments of the present invention.

Disclosure of Invention

The invention provides a diffusion plate which is suitable for a direct type backlight module and is beneficial to reducing the thickness of the direct type backlight module.

The invention also provides a direct type backlight module which has the advantage of thinner thickness.

The invention also provides a display device which has the advantage of thinner thickness.

Other objects and advantages of the present invention will be further understood from the technical features disclosed in the present invention.

In order to achieve one or a part of or all of the above or other objects, a diffuser plate according to an embodiment of the invention is suitable for a direct-type backlight module, and includes a substrate, a first pattern layer, and a second pattern layer. The first pattern layer comprises a plurality of dot patterns distributed on the substrate. The second pattern layer and the first pattern layer are arranged on the same side of the substrate and are partially overlapped with the first pattern layer. The second pattern layer comprises a plurality of shading patterns, each shading pattern comprises a plurality of shading rings distributed from inside to outside, and a plurality of annular gaps are formed between the shading rings.

In order to achieve one or a part of or all of the above or other objects, an embodiment of the invention provides a direct type backlight module including the diffuser plate and a plurality of light emitting elements, wherein the diffuser plate is disposed above the light emitting elements.

In order to achieve one or a part of or all of the above or other objects, an embodiment of the invention provides a display device including a display panel and the direct-type backlight module, wherein a diffuser plate of the direct-type backlight module is disposed between a light emitting element of the direct-type backlight module and the display panel.

The diffusion plate of the embodiment of the invention can effectively reduce the light mixing distance between the light emitting element and the diffusion plate by matching the first pattern layer and the second pattern layer, thereby reducing the thickness of the direct type backlight module and the display device of the embodiment of the invention.

In order to make the aforementioned and other objects, features and advantages of the invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic view of a direct type backlight module according to an embodiment of the invention.

Fig. 2 is a schematic bottom view of the diffuser plate of fig. 1.

Fig. 3 is a schematic bottom view of a diffuser plate according to another embodiment of the invention.

Fig. 4 is a schematic diagram of a display device according to an embodiment of the invention.

Detailed Description

The foregoing and other aspects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment, as illustrated in the accompanying drawings. Directional terms as referred to in the following examples, for example: up, down, left, right, front or rear, etc., are referred to only in the direction of the attached drawings. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting.

Fig. 1 is a schematic view of a direct type backlight module according to an embodiment of the invention. Referring to fig. 1, a direct type backlight module 100 of the present embodiment includes a plurality of light emitting elements 110 and a diffuser plate 200, wherein the diffuser plate 200 is disposed above the light emitting elements 110. The light emitting elements 110 are used for providing light L, and the diffusion plate 200 is used for forming the light L provided by the light emitting elements 110 into a surface light source. In addition, the direct-type backlight module 100 may further include at least one optical film (not shown) disposed above the diffuser 200 to adjust the uniformity or light-emitting angle of the surface light source. For example, the optical film is, for example, a diffusion film, a brightness enhancement film, or the like.

The light emitting element 110 is, for example, a light emitting diode, but may be another type of light emitting element. In addition, each light emitting element 110 has a top surface 111 facing the diffusion plate 200 and a plurality of side surfaces 112 connected to the top surface 111, and the side surfaces 112 are, for example, light emitting surfaces. In the present embodiment, each light emitting element 110 has, for example, four side surfaces 112 connected to each other, so that light can be emitted in 360 degrees. Further, the top surface 111 may be a light emitting surface, or may not be a light emitting surface.

Fig. 2 is a schematic bottom view of the diffuser plate of fig. 1. Referring to fig. 1 and 2, the diffusion plate 200 includes a substrate 210, a first pattern layer 220, and a second pattern layer 230. The second pattern layer 230 and the first pattern layer 220 are disposed on the same side of the substrate 210, and partially overlap with the first pattern layer 220. Specifically, the substrate 210 has an incident surface 212 and an exit surface 214 opposite to each other, the incident surface 212 faces the light emitting element 110, in the embodiment, the first pattern layer 220 and the second pattern layer 230 are disposed on the incident surface 212, for example, in another embodiment, the first pattern layer 220 and the second pattern layer 230 may also be disposed on the exit surface 214. In addition, microstructures may be selectively disposed on the light incident surface 212 and/or the light emitting surface 214 of the substrate 210.

In the present embodiment, at the overlapping position of the first pattern layer 220 and the second pattern layer 230, the first pattern layer 220 is located between the substrate 210 and the second pattern layer 230, for example. For example, the first pattern layer 220 may be formed on the substrate 210 first, and then the second pattern layer 230 may be formed on the substrate 210. In another embodiment, the second patterning layer 230 may be located between the substrate 210 and the first patterning layer 220. For example, the second pattern layer 230 is formed on the substrate 210, and then the first pattern layer 220 is formed on the substrate 210.

The first pattern layer 220 includes a plurality of dot patterns 222 distributed on the substrate 210 for reducing a brightness difference between a region of the light emitting surface 214 corresponding to the light emitting element 110 and other regions of the light emitting surface 214, so as to improve uniformity of the surface light source. In the present embodiment, the distribution of the dot patterns 222 is, for example, dense at the position closer to the orthographic projection P of the light emitting device 110 on the substrate 210, and sparse at the position farther from the orthographic projection P, so as to effectively reduce the brightness difference. The dot pattern 222 is, for example, a dot shape, and the size is, for example, substantially the same, but the dot pattern 222 may have another shape. In addition, in another embodiment shown in fig. 3, the dot pattern 222 may have a larger size at a position closer to the orthographic projection P of the light emitting device 110 on the substrate 210, and the dot pattern 222 may have a smaller size at a position farther from the orthographic projection P, so as to effectively reduce the light-dark difference. In another embodiment, the above-mentioned difference in brightness can be reduced by the distribution density of the adjustment dot patterns 222 of fig. 2 and the size difference of the adjustment dot patterns 222 of fig. 3 at the same time.

The material of the first pattern layer 220 includes white ink, for example, and may be replaced with or added with other color ink according to the requirement. The material of the white ink may include titanium dioxide (TiO2) or silicon dioxide (SiO 2). In addition, the light-dark difference can be reduced by adjusting the thickness of the first pattern layer 220. The thickness of the first pattern layer 220 of the present embodiment is, for example, between 10 microns and 200 microns, preferably between 10 microns and 50 microns. In the manufacturing process, the thickness of the first pattern layer 220 may be increased by printing multiple layers of ink, but the method for adjusting the thickness is not limited thereto. In a comparative example, the difference in brightness is, for example, 26.1% when the first pattern layer 220 is printed with one layer of ink, and is reduced to 9% when the first pattern layer 220 is printed with two layers of ink under the same conditions.

Referring to fig. 1 and 2, the second pattern layer 230 includes a plurality of light-shielding patterns 232, each light-shielding pattern 232 includes a plurality of light-shielding rings 233 distributed from inside to outside, and a plurality of annular gaps 234 are formed between the light-shielding rings 233 for light L to pass through. The light-shielding patterns 232 are disposed relative to the light-emitting elements 110, for example, to improve brightness defects of the light-emitting surface 214 corresponding to the light-emitting elements 110. In the same light-shielding pattern 232, the size of the light-shielding ring 233, the line width of the light-shielding ring 233 and the width of the annular gap 234 may be adjusted according to different design requirements. In one embodiment, the line width of the light shielding ring 233 is, for example, 0.25 mm, and the width of the annular gap 234 is, for example, 0.45 mm.

The shape of the light-shielding ring 233 in fig. 2 is, for example, a circle, but not limited to this, and the shape of the light-shielding ring 233 may be adjusted to an oval shape, a polygon shape, or other shapes as needed. For example, when the pitch of the adjacent light emitting elements 110 in the X-axis direction of fig. 2 is the same as the pitch of the adjacent light emitting elements in the Y-axis direction, the shape of the light shielding ring 233 may be a circle or a regular polygon. When the distance between the adjacent light emitting elements 110 in the X-axis direction of fig. 2 is greater than the distance in the Y-axis direction, the shape of the light shielding ring 233 may be an ellipse or a polygon similar to an ellipse, wherein the major axis direction of the ellipse is, for example, parallel to the X-axis direction, whereas when the distance in the X-axis direction is smaller than the distance in the Y-axis direction, the major axis direction of the ellipse is, for example, parallel to the Y-axis direction. In addition, although each light-shielding ring 233 is a closed ring in fig. 2, the light-shielding ring 233 may also be a non-closed ring, that is, the light-shielding ring may have at least one notch.

The material of the second pattern layer 230 includes black ink, for example, so that the light-shielding pattern 232 has a better light-shielding effect. The black ink can be replaced by or added with other color ink according to the requirement. For example, the first pattern layer 220 may cause a color shift of the light-emitting surface 214 corresponding to the light-emitting device 110, in which case, the material of the second pattern layer 230 may further include a blue ink in addition to the black ink, and the blue ink and the black ink are mixed to improve the color shift.

The second pattern layer 230 may be formed by printing one or more layers of ink, but is not limited thereto. In addition, the thickness of the first pattern layer 220 is, for example, greater than or equal to the thickness of the second pattern layer 230, and if the thickness of the first pattern layer 220 is less than the thickness of the second pattern layer 230, a boundary line with uneven brightness is easily formed at the boundary between the first pattern layer 220 and the second pattern layer 230. In one embodiment, the thickness of the first pattern layer 220 is, for example, 1 to 3 times the thickness of the second pattern layer 230. For example, the first pattern layer 220 is formed by printing two layers of ink, the second pattern layer 230 is formed by printing one layer of ink, and the thickness of the first pattern layer 220 is twice the thickness of the second pattern layer 230.

Compared to the prior art, under the condition of the same light mixing distance D2, the first pattern layer 220 of the diffuser plate 200 of the embodiment can reduce the brightness difference between the area of the light emitting surface 214 corresponding to the light emitting elements 110 and other areas of the light emitting surface 214, so that the surface light source penetrating through the light emitting surface 214 has good uniformity even if the distance D1 between the light emitting elements 110 is increased. Moreover, the second pattern layer 230 can improve the brightness defect and color shift problem, so that the quality of the surface light source can be further improved.

In one embodiment, under the condition that the distance D1 between the light emitting elements 110 is 18 mm and the light mixing distance D2 is 2.5 mm, the surface light source with good uniformity can be obtained, i.e., D1/D2 can be greatly increased to 7.2. Thus, even if the number of the light emitting elements 110 is reduced, the direct-type backlight module 100 of the present embodiment still has the advantage of thin thickness, thereby improving the product competitiveness of the direct-type backlight module 100.

Fig. 4 is a schematic diagram of a display device according to an embodiment of the invention. Referring to fig. 4, the display device 300 of the present embodiment includes a display panel 310 and a direct type backlight module of any of the above embodiments, such as the direct type backlight module 100, wherein the diffuser plate 200 is disposed between the light emitting elements 110 and the display panel 310. The display panel 310 is, for example, a liquid crystal display panel or other types of display panels, the direct-type backlight module 100 is used for providing the surface light source SL to the display panel 310, and the display panel 310 is used for converting the surface light source SL into an image frame.

Since the direct type backlight module 100 has the advantage of thin thickness, the display device 300 of the present embodiment also has the advantage of thin thickness.

The above description is only a preferred embodiment of the present invention, and the scope of the present invention should not be limited thereby, and all the simple equivalent changes and modifications made by the claims and the description of the present invention are within the scope of the present invention. Moreover, it is not necessary for any embodiment or claim of the invention to address all of the objects, advantages, or features disclosed herein. In addition, the abstract and the title of the invention are provided for assisting the retrieval of patent documents and are not intended to limit the scope of the invention. Furthermore, the terms "first," "second," and the like in the description or in the claims are used only for naming elements (elements) or distinguishing different embodiments or ranges, and are not used for limiting the upper limit or the lower limit on the number of elements.

Reference numerals

100: direct type backlight module

110: light emitting element

111: the top surface

112: side surface

200: diffusion plate

210: substrate

212: light incident surface

214: light emitting surface

220: first pattern layer

222: dot pattern

230: second pattern layer

232: shading pattern

233: shading ring

234: annular gap

300: display device

310: display panel

D1: distance between each other

D2: distance of mixing light

L: light ray

SL: area light source

P: and (4) orthographic projection.