Diffusion plate, direct type backlight module and display device

Abstract

The utility model discloses a diffusion plate, direct type backlight module and display device, this diffusion plate is including by the diffusion plate main part of the light -transmitting material, and the diffusion plate main part is equipped with the light entrance surface and the light exit surface of opposite setting, and the light entrance surface is the plane, and the light exit surface is equipped with the convex part and the recess, to form the uneven plane, and the height of convex part is 100~150um, and, the surface roughness Ra of light exit surface is 35~50um. The simple, novel, reasonable of this diffusion plate, the light -emitting performance is good, and the yield is high, and can realize bigger, more thin -type development, very good satisfied direct type backlight module and display device and other product's use demand.

Description

Technical Field

[0001] This utility model relates to the field of optoelectronic display technology, and in particular to a diffuser plate, a direct-lit backlight module, and a display device. Background Technology

[0002] When manufacturing diffuser plates using injection molding, the presence of silicon particles in the raw material formulation can cause these particles to scrape away impurities adhering to the screw and carry them into the finished diffuser plate. This is especially true under high-temperature molding conditions, where impurities adhering to the screw are particularly prone to detachment. Once these impurities are mixed into the diffuser plate product, they are identified as black spots, thus being judged as defective and scrapped. Compared to ordinary transparent materials, diffuser plates containing silicon particles have an average yield reduction of about 10%, leading to the challenge of controlling and reducing processing costs.

[0003] Production testing has shown that controlling the processing temperature at around 280℃ increases the yield rate of diffuser plates. However, as diffuser plate products become larger and thinner, the desired shape cannot be achieved without increasing the resin molding temperature. In this case, there is currently no other solution than increasing the defect rate.

[0004] In view of the above, this utility model is hereby proposed. Summary of the Invention

[0005] To overcome the above-mentioned defects, this utility model provides a diffuser plate, a direct-lit backlight module, and a display device. The diffuser plate has a simple, novel, and reasonable structure, excellent light emission performance, high yield, and can be made larger and thinner, which well meets the usage requirements of products such as direct-lit backlight modules and display devices.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a diffuser plate, including a diffuser plate body made of light-transmitting material, the diffuser plate body having an incident light surface and an exit light surface arranged opposite to each other, the incident light surface being a plane, the exit light surface having a protrusion and a concave part to form an uneven plane, and the height of the protrusion being 100-150μm, and the surface roughness Ra of the exit light surface being 35-50μm.

[0007] As a further improvement of this utility model, the surface roughness Sa of the light-emitting surface is 35-50 μm.

[0008] As a further improvement of this utility model, the convex part and the concave part are integrally formed on the light-emitting surface.

[0009] As a further improvement of this utility model, the convex portion and the concave portion extend from one side of the light-emitting surface to the opposite side of the light-emitting surface, and the convex portion and the concave portion are configured in multiples and alternately arranged in sequence, so that the light-emitting surface presents a wavy shape.

[0010] As a further improvement of this utility model, based on the horizontal placement of the diffuser plate, the vertical cross-sectional shape of the convex part and the vertical cross-sectional shape of the concave part are inverted relative to each other, and both are regular or irregular shapes.

[0011] As a further improvement of this utility model, the protrusions and the concave parts are configured in multiple ways and distributed on the light-emitting surface in a regular array arrangement or an irregular array arrangement.

[0012] As a further improvement of this utility model, based on the horizontal placement of the diffuser plate, the protrusion is a hemispherical, truncated cone, square pyramid, frustum, or irregular shape.

[0013] This utility model also provides a direct-lit backlight module, including a light source, a diffuser plate as described in this utility model, and an optical film assembly. The diffuser plate is disposed above the light source to uniformly diffuse the light emitted by the light source. The optical film assembly is disposed above the light-emitting surface of the diffuser plate to optimize the light emitted from the light-emitting surface.

[0014] As a further improvement of this utility model, the optical film assembly includes a beam-splitting film, a diffusion film, and a DBEF film arranged sequentially from bottom to top.

[0015] This utility model also provides a display device, including the direct-lit backlight module as described in this utility model.

[0016] The beneficial effects of this utility model are: 1) By designing the light-emitting surface as a non-planar surface and specifically controlling the height of the protrusion and the surface roughness of the light-emitting surface, this utility model can effectively improve the problems caused by black spot defects, significantly improving the light emission performance of the diffuser plate, greatly increasing the yield rate of the diffuser plate, and promoting the thinning development of the diffuser plate. 2) The diffuser plate of this utility model has a simple, novel, and reasonable structure, is easy to process and manufacture, and has low manufacturing cost, which is conducive to product processing and production. 3) With the diffuser plate provided by this utility model, products such as direct-lit backlight modules and display devices using the diffuser plate can have advantages such as excellent light emission performance, high yield rate, and the ability to achieve larger and thinner designs, which well meets market demand. Attached Figure Description

[0017] Figure 1This is a three-dimensional structural diagram of the diffuser plate described in Embodiment 1 of this utility model;

[0018] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure of the diffuser plate shown;

[0019] Figure 3 This is a three-dimensional structural diagram of the diffuser plate described in Embodiment 2 of this utility model;

[0020] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of the diffuser plate shown;

[0021] Figure 5 This is a cross-sectional structural diagram of the direct-lit backlight module described in Embodiment 3 of this utility model;

[0022] Figure 6 This is a view of the diffuser plate under illumination; where... Figure 6 Figure a) shows the appearance of a conventional diffuser plate under light source illumination; Figure b) shows the appearance of the diffuser plate provided in Example 1 under light source illumination.

[0023] Figure 7 This is a diagram showing the appearance of an optical assembly composed of a brightness enhancement film (BEF) and a diffuser plate stacked together under illumination; where... Figure 7 Figure a) shows the appearance of optical component A, which is composed of a brightness enhancement film BEF and a conventional diffuser plate stack, under light source illumination; Figure b) shows the appearance of optical component B, which is composed of a brightness enhancement film BEF and a diffuser plate stack provided in Example 1, under light source illumination.

[0024] Referring to the accompanying drawings, the following explanations are provided:

[0025] 1. Diffuser plate; 10. Diffuser plate body; 100. Light-incident surface; 101. Light-exiting surface; 102. Protrusion; 103. Recess; 2. Light source; 3. Beam splitter; 4. Diffuser film; 5. DBEF film; 6. Display panel. Detailed Implementation

[0026] The preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0027] Example 1

[0028] This embodiment 1 provides a diffuser plate that effectively overcomes the problems of low yield and limited thin-film development caused by black spot defects in existing diffuser plates. It significantly improves the light emission performance of the diffuser plate, greatly increases its yield, and promotes its thin-film development. Therefore, the diffuser plate provided in this embodiment 1 can be well applied to direct-lit backlight modules and display devices (such as flat panel displays, FPDs) that include direct-lit backlight modules.

[0029] The specific structure of the diffuser plate described in Embodiment 1 will be described in detail below.

[0030] Please see the appendix Figure 1 and 2 As shown, the diffuser plate 1 provided in this embodiment 1 includes a diffuser plate body 10 made of a light-transmitting material. The diffuser plate body 10 has a light-incident surface 100 and a light-emitting surface 101 arranged opposite to each other. In particular, the light-incident surface 100 is a plane, and the light-emitting surface 101 has a protrusion 102 and a concave surface 103 to form a non-planar surface. The height H of the protrusion 102 is optimally designed to be 100-150 μm, and the surface roughness Ra of the light-emitting surface 101 is optimally designed to be 35-50 μm and the surface roughness Sa is optimally designed to be 35-50 μm.

[0031] Understandably, the raw material formulation of the diffuser plate typically includes, in addition to the main optical polycarbonate material, a predetermined amount of light diffusing agent. This light diffusing agent is generally composed of silicon particles (or organosilicon microspheres), silica, and silicone oil. By utilizing the refractive index difference between air, polycarbonate material, and the light diffusing agent, the LED light source, substrate, reflector cup, etc., located below the diffuser plate are not easily visible, effectively ensuring the performance of the direct-lit backlight module and display device. However, black spots distributed on the diffuser plate body 10, especially large black spots with a diameter of 0.3 mm or more, are easily visible. Therefore, in order to improve the adverse effects caused by black spots, this application designs the light-emitting surface 101 as a non-planar surface with concave and convex features, and specifically optimizes the height of the protrusion 102 and the surface roughness of the light-emitting surface 101. On the one hand, by using the concave and convex structure and controlling the roughness, the multiple refractions and diffuse reflections of light on the light-emitting surface 101 can be enhanced, thereby effectively eliminating the phenomenon of local over-brightness or dark areas, achieving a more uniform distribution of surface light sources, and thus better covering the black spots distributed inside the diffuser plate body 10 and on the light-incident surface 100. On the other hand, by controlling the height of the protrusion 102 within a reasonable range (which can also be understood as controlling the distance between the protrusion 102 and the concave part 103 within a reasonable range), the scattered light at the concave part 103 can be increased, thereby achieving a good halo effect (also known as a blurring effect or shadow effect) on the black spots distributed at the concave part 103, that is, making the black spots distributed at the concave part 103 less noticeable. In summary, through the above-mentioned structural improvements of this application, although the black spots distributed at the protrusion 102 are still visible, the black spots distributed at the recess 103, inside the diffuser plate body 10, and on the light-incident surface 100 are all effectively covered, thereby effectively improving the problems caused by the black spot defects. This not only significantly improves the light emission performance of the diffuser plate, but also greatly increases the yield of the diffuser plate and promotes the thinning development of the diffuser plate.

[0032] Additional notes: Surface roughness Ra is evaluated based on the line profile method, while surface roughness Sa is based on the regional topography.

[0033] Please continue to refer to the appendix. Figure 1 and attached Figure 2 As shown, in the structure of the diffuser plate 1 provided in this embodiment 1, the protrusion 102 and the recess 103 extend from one side of the light-emitting surface 101 to the opposite side of the light-emitting surface 101, and the protrusion 102 and the recess 103 are arranged in multiples and alternately arranged in sequence, so that the light-emitting surface 101 presents a wave shape. It can be understood that the height H of the protrusion 102 is the wave height.

[0034] Furthermore, the protrusion 102 and the recess 103 are integrally formed on the light-emitting surface 101, which can be achieved through etching or injection molding processes, but not limited to.

[0035] Furthermore, taking the horizontal placement of the diffuser plate 1 as a reference, the vertical cross-sectional shape of the protrusion 102 and the vertical cross-sectional shape of the recess 103 are inverted relative to each other, and both are either regular or irregular shapes; specifically, regular shapes may include, but are not limited to, arcs, rectangles, or triangles. Additionally, according to product design requirements, the vertical cross-sectional shapes of the protrusion 102 and the recess 103 may also be designed to be different.

[0036] In addition, this application also conducts performance tests on the diffusion plate, and the specific test content and results are as follows:

[0037] 1.1) Place the conventional diffuser plate and the diffuser plate provided in Embodiment 1 above the LED light source respectively. After the LED light source is turned on, visually observe the appearance of the two diffuser plates; the test results are shown in the appendix. Figure 6 As shown.

[0038] From the appendix Figure 6 As can be seen, black spots are clearly visible on traditional diffuser plates. Figure 6 The part circled in red in figure a) is shown; while the black dots on the diffuser plate described in embodiment 1 are more blurred and visible. Figure 6 (b) The part circled in yellow in the picture is not easy to see.

[0039] 1.2) The brightness enhancement film BEF and the conventional diffuser plate are stacked together to form optical component A, and the brightness enhancement film BEF and the diffuser plate provided in Embodiment 1 are stacked together to form optical component B; then the two optical components are respectively placed above the LED light source, and after the LED light source is turned on, the appearance of the two optical components is visually observed; the test results are shown in the appendix. Figure 7 As shown.

[0040] From the appendix Figure 7 As can be seen, black spots are easily visible on optical component A. Figure 7 a) The part circled in yellow in the figure; while no black dots are visible on optical component B, specifically... Figure 7 As shown in Figure b).

[0041] The above tests verify that the diffuser plate provided in this embodiment 1 can effectively improve the problems caused by black spot defects, significantly improve the light emission performance of the diffuser plate, increase the yield of the diffuser plate, and promote the thinning of the diffuser plate.

[0042] Example 2

[0043] This embodiment 2 also provides a diffusion plate, and compared with embodiment 1, the diffusion plate provided in this embodiment 2 has the following differences: ① The shape and distribution of the protrusion 102 and the concave portion 103 in the diffusion plate of this embodiment 2 are different from those in embodiment 1.

[0044] Specifically, in the diffuser plate structure provided in Embodiment 2, the distribution of the protrusions 102 and the recesses 103 is as follows: Multiple protrusions 102 and recesses 103 are respectively configured and distributed on the light-emitting surface 101 in a regular array arrangement or an irregular array arrangement. (See attached diagram) Figure 3 The illustration shows a scenario where multiple protrusions 102 and multiple recesses 103 are arranged in a regular array on the light-emitting surface 101. More specifically, multiple protrusions 102 are arranged into a protrusion group along a first direction, and multiple recesses 103 are also arranged into a recess group along the first direction. Then, multiple protrusion groups and multiple recess groups are arranged alternately side by side along a second direction perpendicular to the first direction.

[0045] Furthermore, based on the horizontal placement of the diffuser plate, the protrusion 102 can be designed as, but is not limited to, a hemisphere, a truncated cone, a square pyramid, a frustum, or an irregular shape. (The attached text appears to be incomplete and requires further context.) Figure 3 and attached Figure 4 This illustrates a scenario where the protrusion 102 is a hemispherical shape and the shape of the concave portion 103 is an inversion of the shape of the protrusion 102.

[0046] In addition to the differences mentioned above, in the diffuser plate structure described in this embodiment 2, the height control of the protrusion 102, the surface roughness control of the light-emitting surface 101, and the forming methods of the protrusion 102 and the concave portion 103 relative to the light-emitting surface 101 can all adopt the same technical means as in embodiment 1, so they will not be described in detail here.

[0047] Example 3

[0048] Please see the appendix Figure 5 As shown, this embodiment 3 provides a direct-lit backlight module, which includes a light source 2, a diffuser plate 1 as prepared in embodiment 1 or 2 above, and an optical film assembly. The diffuser plate 1 is disposed above the light source 2 to uniformly diffuse the light emitted by the light source 2. The optical film assembly is disposed above the light-emitting surface 101 of the diffuser plate 1 to optimize the light emitted from the light-emitting surface 101.

[0049] Furthermore, the optical film assembly includes a beam-splitting film 3, a diffusion film 4, and a DBEF film 5 (also known as a dual brightness enhancement film) arranged sequentially from bottom to top. The beam-splitting film 3 is used to control the scattering, reflection, and absorption of light of a specific wavelength. It can separate photons of different wavelengths to analyze the spectrum of different wavelengths and use them to achieve specific optical effects. The diffusion film 4 can correct the light to a uniform surface light source to achieve the effect of optical diffusion. The DBEF film 5 can maximize the utilization efficiency of the light source.

[0050] Based on the functional advantages of the diffuser plate obtained in Embodiment 1 or 2 above, the direct-lit backlight module provided in Embodiment 3 has excellent light emission performance, high yield, and can achieve larger and thinner designs.

[0051] Example 4

[0052] This embodiment 4 provides a display device, which includes a display panel 6 and a direct-lit backlight module as provided in embodiment 3 above, wherein the display panel 6 is disposed above the direct-lit backlight module.

[0053] Understandably, based on the functional advantages of the diffuser plate and the direct-lit backlight module, the display device has excellent display effect, high yield rate, and can achieve a large viewing area and thin size, making it more comfortable for users to watch and use, and providing a very good experience.

[0054] Note: The prefixes "first", "second", etc. (e.g., first direction, second direction, etc.) in the component names of this specification, as well as the suffixes "A", "B", etc. (e.g., optical component A, optical component B, etc.) in the component names, are only for ease of description and are not intended to limit the scope of implementation of this invention.

[0055] In summary, compared with the prior art, the diffuser plate of this utility model has a simple, novel, and reasonable structure, excellent light emission performance, high yield rate, and can achieve larger and thinner designs, which well meets the usage requirements of products such as direct-lit backlight modules and display devices.

[0056] Many specific details have been set forth in the above description to provide a full understanding of this utility model. However, the above description is only a preferred embodiment of this utility model, and this utility model can be implemented in many other ways different from those described herein. Therefore, this utility model is not limited to the specific embodiments disclosed above. Furthermore, any person skilled in the art can make many possible variations and modifications to the technical solution of this utility model using the methods and techniques disclosed above, or modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of this utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model, without departing from the content of the technical solution of this utility model, shall still fall within the protection scope of the technical solution of this utility model.

Claims

1. A diffuser plate, comprising a diffuser plate body (10) made of a light-transmitting material, wherein the diffuser plate body (10) has an incident light surface (100) and an exit light surface (101) disposed opposite to each other, characterized in that: The light-incident surface (100) is a plane, and the light-exiting surface (101) is provided with a protrusion (102) and a recess (103) to form an uneven plane. The height of the protrusion (102) is 100-150 μm, and the surface roughness Ra of the light-exiting surface (101) is 35-50 μm.

2. The diffusion plate of claim 1, wherein: The surface roughness Sa of the light-emitting surface (101) is 35-50 μm.

3. The diffuser plate according to claim 1, characterized in that: The protrusion (102) and the recess (103) are integrally formed on the light-emitting surface (101).

4. The diffusion plate of claim 1, wherein: The protrusion (102) and the recess (103) extend from one side of the light-emitting surface (101) to the opposite side of the light-emitting surface (101), and the protrusion (102) and the recess (103) are arranged in multiples and alternately arranged in sequence, so that the light-emitting surface (101) appears wavy.

5. The diffusion plate of claim 4, wherein: Based on the horizontal placement of the diffuser plate, the vertical cross-sectional shape of the protrusion (102) and the vertical cross-sectional shape of the concave part (103) are inverted relative to each other, and both are either regular or irregular shapes.

6. The diffusion plate of claim 1, wherein: The protrusions (102) and the recesses (103) are configured in multiple ways and are distributed on the light-emitting surface (101) in a regular array or an irregular array.

7. The diffuser plate according to claim 6, characterized in that: Based on the horizontal placement of the diffuser plate, the protrusion (102) can be a hemisphere, a truncated cone, a square pyramid, a frustum, or an irregular shape.

8. A direct backlight module, characterized in that: The device includes a light source (2), a diffuser plate (1) as described in any one of claims 1-7, and an optical film assembly. The diffuser plate (1) is disposed above the light source (2) to uniformly diffuse the light emitted from the light source (2). The optical film assembly is disposed above the light-emitting surface (101) of the diffuser plate (1) to optimize the light emitted from the light-emitting surface (101).

9. The direct-lit backlight module according to claim 8, characterized in that: The optical film assembly includes a beam splitter (3), a diffuser (4), and a DBEF film (5) arranged sequentially from bottom to top.

10. A display device, characterized by comprising: Including the direct-lit backlight module as described in claim 8.

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