Diffusion plate and backlight module

Abstract

The diffusion plate is arranged above a back plate, at least one light source is arranged on the back plate, the diffusion plate comprises a diffusion layer and at least one light guide column connected to the diffusion layer, the light guide column is correspondingly arranged above the light source, and the refractive index of the light guide column is larger than that of air. Light beams emitted from the light source are totally reflected in the light guide column, mixed through the diffusion layer and emitted from the side, away from the light guide column, of the diffusion layer. According to the technical scheme, the technical problems that a traditional backlight module cannot achieve local area light equalization, light crosstalk is serious, the light mixing effect is poor, and the display effect is poor are effectively solved.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and particularly relates to a diffusion plate and a backlight module. Background Art

[0002] With the rapid development of science and technology, the use of liquid crystal displays has become more and more popular. At present, the backlights of liquid crystal displays mainly include two types: edge-lit type and direct-lit type. Among them, for the edge-lit type backlight, the LED light bars are placed on the side edges of the backlight module, and the light is evenly distributed on the surface by means of a light guide plate, and local area light uniformity cannot be achieved; for the direct-lit type backlight, the LED arrays are placed on the backplane, and then the diffusion plate is supported by support columns to form a light channel between the diffusion plate and the backplane, and the light is emitted from the front surface of the diffusion plate. Although the direct-lit type backlight can achieve local area light uniformity adjustment, when different LED lights pass through the light channel, light crosstalk is likely to occur, resulting in a poor overall light mixing effect and a poor display effect. Utility Model Content

[0003] The present application provides a diffusion plate and a backlight module to solve the technical problems that the traditional backlight module cannot achieve local area light uniformity, has serious light crosstalk, a poor light mixing effect, and a poor display effect.

[0004] To this end, in a first aspect, an embodiment of the present application provides a diffusion plate disposed above a backplane, at least one light source is provided on the backplane, the diffusion plate includes a diffusion layer and at least one light guide column connected to the diffusion layer, the light guide column is correspondingly disposed above the light source, and the refractive index of the light guide column is greater than the refractive index of air, so that the light beam emitted from the light source undergoes total internal reflection in the light guide column, and then is mixed with light through the diffusion layer and emitted from the side of the diffusion layer away from the light guide column.

[0005] In a possible implementation manner, the light guide column includes an incident surface and a plurality of total internal reflection surfaces wound around the periphery of the incident surface, the plurality of total internal reflection surfaces extend in the same direction and are connected to the diffusion layer to enclose a light diffusing surface on the diffusion layer, and the projected area of the incident surface on the diffusion layer is received in the light diffusing surface.

[0006] In a possible implementation manner, the angle between the total internal reflection surface and the diffusion layer is 110° to 150°.

[0007] In a possible implementation manner, it further includes an avoidance groove provided on the incident surface, the avoidance groove extends toward the diffusion layer and is used to receive the light source.

[0008] In a possible implementation manner, in the direction from the diffusion layer to the light guide column, the thickness of the light guide column is 3 mm to 8 mm; and / or,

[0009] In the direction from the diffusion layer to the light guide column, the thickness of the diffusion layer is 0.5 mm to 3 mm.

[0010] In a possible implementation, the haze of the diffusion layer is 20% - 80%.

[0011] In a possible implementation, the side of the diffusion layer away from the light guide column is a frosted surface;

[0012] Alternatively, a plurality of light diffusing agents are provided in the diffusion layer.

[0013] In a possible implementation, the diffusion layer and the light guide column are integrally formed.

[0014] In a possible implementation, the material of the light guide column is any one of polycarbonate, polymethyl methacrylate, epoxy resin, polyurethane, or polystyrene; and / or,

[0015] The material of the diffusion layer is any one of polycarbonate, polymethyl methacrylate, epoxy resin, polyurethane, or polystyrene.

[0016] In a second aspect, the present application further provides a backlight module, including a backplane, at least one light source, and the diffusion plate as described above. The light source is disposed on the backplane, and the light guide column of the diffusion plate is disposed above the light source.

[0017] According to the diffusion plate and the backlight module provided by the embodiments of the present application, the diffusion plate is disposed above the backplane, at least one light source is provided on the backplane, the diffusion plate includes a diffusion layer and at least one light guide column connected to the diffusion layer. The light guide column is correspondingly disposed above the light source, and the refractive index of the light guide column is greater than the refractive index of air, so that after the light beam emitted from the light source undergoes total internal reflection in the light guide column, it is mixed with light through the diffusion layer and exits from the side of the diffusion layer away from the light guide column. Compared with the optical path mode of the traditional backlight module that needs to support the diffusion plate through support columns and the light beam is prone to crosstalk when propagating in the air channels formed by the support columns, the technical solution of the present application provides a new optical path mode in which the light beam only propagates in the light guide column and the diffusion layer and does not propagate through the air, avoiding the problem of crosstalk during the propagation of the light beam and improving the light homogenization effect of the diffusion plate. The refractive index of the light guide column is relatively high, enabling the light beam to undergo total internal reflection at the interface between the light guide column and the air, thereby confining the light beam in the light guide column and making it propagate in the light guide column, reducing light loss and waste, and improving light utilization rate; then it is mixed with light through the diffusion layer and exits, improving the light mixing effect and the display effect of the display module. Moreover, since the light guide column provides a light channel for the light source disposed below it, the local light homogenization effect can be achieved by controlling the on and off of the light source below. In addition, the light guide column in the diffusion plate provided in this embodiment can also act as the role of the traditional support column, reducing the setting of the traditional support column, with stronger support stability and a more reliable overall structure. Description of the Drawings

[0018] The accompanying drawings here are incorporated into and constitute a part of this specification, showing embodiments in line with this application, and are used together with the specification to explain the principles of this application. To more clearly illustrate the technical solutions in the embodiments of this application or in the prior art, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. One or more embodiments are exemplarily illustrated by the pictures in the corresponding accompanying drawings. These exemplary illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the drawings in the figures do not constitute a scale limitation.

[0019] Figure 1 Schematic three-dimensional structure diagram of the diffusion plate provided for the embodiment of this application;

[0020] Figure 2 is Figure 1 side view of;

[0021] Figure 3 Schematic three-dimensional structure diagram of the diffusion plate provided for the embodiment of this application from a bottom-up perspective;

[0022] Figure 4 is Figure 3 partial enlarged view of;

[0023] Figure 5 Side view of the backlight module provided for the embodiment of this application.

[0024] Explanation of reference numerals in the drawings:

[0025] 100, diffusion layer;

[0026] 200, light guide column; 201, incident surface; 202, total reflection surface;

[0027] 300, avoidance groove;

[0028] α, included angle;

[0029] 10, back plate; 20, light source; 30, diffusion plate. Detailed implementation manners

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some but not all of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts fall within the scope of protection of this application.

[0031] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the applicability of other processes and / or the use of other materials.

[0032] For ease of description, spatially relative relationship terms may be used in the text to describe the relative positional relationship or movement of one element or feature shown in the figure with respect to another element or feature. These relative relationship terms such as "inside", "outside", "inner side", "outer side", "below", "beneath", "above", "over", "front", "rear", etc. This spatially relative relationship term is intended to include different orientations of the device in use or operation other than the orientation depicted in the figure. For example, if the device in the figure undergoes a position flip or a posture change or a change in the motion state, then these directional indications will also change accordingly. For example, an element described as "below other elements or features" or "beneath other elements or features" will then be oriented as "above other elements or features" or "over other elements or features". Therefore, the exemplary term "below" can include both the upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or in other directions) and the spatially relative relationship descriptors used in the text are interpreted accordingly.

[0033] See Figures 1 to 4 , an embodiment of the present application provides a diffusion plate disposed above a back plate 10. At least one light source 20 is provided on the back plate 10. The diffusion plate 30 includes a diffusion layer 100 and at least one light guide column 200 connected to the diffusion layer 100. The light guide column 200 is correspondingly disposed above the light source 20, and the refractive index of the light guide column 200 is greater than the refractive index of air, so that the light beam emitted from the light source 20 undergoes total internal reflection in the light guide column 200, is mixed with light by the diffusion layer 100, and is emitted from the side of the diffusion layer 100 away from the light guide column 200.

[0034] Compared with the optical path mode of the traditional backlight module where the diffusion plate 30 is supported by support columns and light beams are prone to crosstalk when propagating in the air channels formed by the support columns, the technical solution of the present application provides a new optical path mode in which the light beams only propagate within the light guide column 200 and the diffusion layer 100, without passing through the air, avoiding the problem of crosstalk during the propagation of the light beams and improving the light homogenization effect of the diffusion plate 30. The refractive index of the light guide column 200 is relatively high, enabling total internal reflection of the light beams at the interface between the light guide column 200 and the air, thereby confining the light beams within the light guide column 200, making them propagate within the light guide column 200, reducing light refraction loss and waste, and improving light utilization efficiency; then, the light beams are mixed and emitted through the diffusion layer 100, improving the light mixing effect and the display effect of the display module. Moreover, since the light guide column 200 provides a light channel for the light source 20 disposed below it, the local light homogenization effect can be achieved by controlling the on / off of the light source 20 below. In addition, the light guide column 200 in the diffusion plate 30 provided in this embodiment can also act as a traditional support column, reducing the setting of traditional support columns, with stronger support stability and a more reliable overall structure.

[0035] Specifically, the diffusion plate 30 is configured as a combined component including at least the diffusion layer 100 and at least one light guide column 200. The diffusion layer 100 can be a flat plate-like structure, used to provide a light mixing space for the light beams emitted from the light guide column 200 and improve the light homogenization effect. The light guide column 200 can be a near-conical polyhedron component, which can be disposed below the diffusion layer 100 and is used to guide the light beams emitted from the light source 20 into the diffusion layer 100; at the same time, the refractive index of the light guide column 200 is greater than the refractive index of the air, so as to avoid refraction of the light beams at the interface between the light guide column 200 and the air, causing crosstalk and light loss, ensuring total internal reflection of the light beams at this interface, thereby confining the light beams within the light guide column 200, improving the light propagation effect, and improving the display effect of the backlight module. The diffusion plate 30 provided in this example can achieve local light homogenization and zonal dimming effects, without the problem of crosstalk, no smear in dynamic pictures, excellent image quality, and high contrast; moreover, the support stability is high and the reliability is strong.

[0036] In one example, the refractive index of the light guide column 200 is 1.4 - 1.6, and the refractive index of the air is 1. The refractive index of the light guide column 200 is much greater than the refractive index of the air, which can ensure that the light beams within the light guide column 200 will not refract into the surrounding air and only propagate within the light guide column 200, improving light utilization efficiency. For example but not limited to, the refractive index of the light guide column 200 is 1.5.

[0037] As Figure 3As shown, in one example, a plurality of light sources 20 are provided. The plurality of light sources 20 are arranged in columns or rows or an array on the backplane 10; a plurality of light guide columns 200 are provided. The plurality of light guide columns 200 are arranged in columns or rows or an array on the diffusion layer 100, and one light guide column 200 corresponds to one light source 20. In this way, a large-area uniform light effect can be achieved, and the display size can be increased; moreover, zoned light control and local uniform light can be performed as needed, improving the display effect of dynamic pictures, with excellent picture quality and high picture contrast.

[0038] As Figures 1 to 4 shown, in a possible implementation manner, the light guide column 200 includes an incident surface 201 and a plurality of total reflection surfaces 202 wound around the periphery of the incident surface 201. The plurality of total reflection surfaces 202 extend in the same direction and are connected to the diffusion layer 100 to enclose a light expansion surface on the diffusion layer 100. The projected area of the incident surface 201 on the diffusion layer 100 is received within the light expansion surface.

[0039] In this embodiment, the specific configuration of the light guide column 200 is optimized. Specifically, the light guide column 200 is configured to be a composite structure including at least an incident surface 201 and a plurality of total reflection surfaces 202. The incident surface 201 can be a nearly rectangular surface, with a size comparable to that of the LED light source. The light beam emitted by the LED light source enters the light guide column 200 from the incident surface 201. The total reflection surface 202 can be a nearly trapezoidal surface, which constitutes the peripheral side wall of the light guide column 200 and is the interface between the light guide column 200 and the air; the plurality of total reflection surfaces 202 enclose a light expansion surface on the diffusion layer 100, and the size of the light expansion surface is larger than that of the incident surface 201. In this way, light expansion of the light beam can be achieved through the light guide column 200; the light beam propagates in the light guide column 200 and undergoes multiple total reflections by different total reflection surfaces 202, with a good uniform light effect; moreover, the plurality of light sources 20 respectively propagate light beams through the corresponding light guide columns 200, and there is no light crosstalk problem, and the light propagation effect is good. The light guide column 200 provided in this example has a simple structure, is convenient for processing, can be mass-produced on an assembly line, and has strong versatility.

[0040] As Figure 2As shown, in a possible implementation, the included angle α between the total reflection surface 202 and the diffusion layer 100 is 110° to 150°. With such a setting, the slope of the total reflection surface 202 can be maintained within a suitable range, avoiding the situation that the included angle α between the total reflection surface 202 and the bottom surface of the diffusion layer 100 is too large, resulting in too small a light diffusion surface on the diffusion layer 100 and an increase in the number of required LED light sources, reducing the cost of the diffusion plate 30 and increasing market competitiveness; or, avoiding the situation that the included angle α between the total reflection surface 202 and the bottom surface of the diffusion layer 100 is too small, resulting in too large a light diffusion surface on the diffusion layer 100 and too low brightness of the light diffusion surface, improving the light propagation effect. The display screen of the diffusion plate 30 provided in this example has high brightness and contrast, and good display screen quality. For example but not limited to, the included angle α between the total reflection surface 202 and the diffusion layer 100 is 120°, 130° or 140°.

[0041] As Figure 3 and Figure 4 shown, in a possible implementation, it further includes an avoidance groove 300 provided on the incident surface 201, and the avoidance groove 300 extends towards the diffusion layer 100 for accommodating the light source 20.

[0042] In this embodiment, the specific configuration of the diffusion plate 30 is further optimized. Specifically, the diffusion plate 30 is configured as a combined component at least including a diffusion layer 100, at least one light guide column 200 and a plurality of avoidance grooves 300. The avoidance grooves 300 are provided on the incident surface 201 and recess into the light guide column 200 to form an accommodation chamber for accommodating the light source 20. In this way, it can not only avoid the situation that the light guide column 200 directly contacts the light source 20 and damages the light source 20, strengthening the mechanical protection of the light source 20; but also enable the incident surface 201 to abut against the back plate 10 on the periphery of the light source 20, gather the light beam emitted by the light source 20 in the avoidance groove 300 and inject it into the light guide column 200, avoiding light leakage and light crosstalk problems at the gap between the incident surface 201 and the back plate 10, and improving the light propagation effect and light homogenization effect. In addition, arranging the light source 20 in the avoidance groove 300 can also reduce the overall thickness of the backlight module, making the layout more compact and facilitating the realization of a thin and light layout of the backlight module.

[0043] In an example, the LED light source can be encapsulated in the avoidance groove 300 through a transparent encapsulation adhesive, and the connection fastening property is strong. Of course, in other embodiments, a limit snap ring structure can also be provided at the open end of the avoidance groove 300 to cooperate with the peripheral edge of the light source 20, insert the light source 20 into the avoidance groove 300, and clamp the light source 20 through the limit snap ring to realize the connection fastening between the light guide column 200 and the light source 20. The specific connection manner between the light source 20 and the avoidance groove 300 is not limited herein.

[0044] In a possible implementation, in the direction from the diffusion layer 100 to the light guide column 200, the thickness of the light guide column 200 is 3 mm to 8 mm. With such a setting, the thickness of the light guide column 200 can be within a suitable range, avoiding the excessive thickness of the light guide column 200 resulting in too long a light propagation path and too large an overall thickness of the backlight module, improving the light propagation speed and display effect, reducing the weight of the backlight module, and achieving a thin and light layout of the backlight module; or, avoiding the too small thickness of the light guide column 200 from affecting the light homogenization effect. The light diffusing plate 30 provided in this example has high light uniformity and good display picture quality. For example but not limited to, the thickness of the light guide column 200 is 4 mm, 5 mm, 5.5 mm, 6 mm or 7 mm.

[0045] In a possible implementation, in the direction from the diffusion layer 100 to the light guide column 200, the thickness of the diffusion layer 100 is 0.5 mm to 3 mm. With such a setting, the diffusion layer 100 can be within a suitable range, avoiding the excessive thickness of the diffusion layer 100 resulting in too large an overall thickness of the backlight module and achieving a thin and light layout of the backlight module; or, avoiding the too small thickness of the diffusion layer 100 from affecting the light mixing and diffusing effect and improving the dynamic display picture quality. For example but not limited to, the thickness of the diffusion layer 100 is 1 mm, 1.5 mm, 2 mm or 2.5 mm.

[0046] In a possible implementation, the haze of the diffusion layer 100 is 20% to 80%. With such a setting, the diffusion layer 100 can be kept within a suitable light transmission range, avoiding the excessive haze of the diffusion layer 100 from affecting the light transmission effect, or, avoiding the too small haze of the diffusion layer 100 from affecting the light mixing and diffusing effect, improving the light output effect of the light diffusing plate 30, and improving the display quality of the backlight module. For example but not limited to, the haze of the diffusion layer 100 is 30%, 50% or 70%.

[0047] In a possible implementation, the side of the diffusion layer 100 away from the light guide column 200 is a frosted surface. This example provides a surface diffusion method, which sets the light output side of the diffusion layer 100 as a frosted surface to enhance the light diffusing effect at the light output surface and improve the light homogenization effect of the light diffusing plate 30. In addition, the frosted surface can be obtained by sandblasting process, or by processes such as grinding and deburring. The obtaining method of the frosted surface is not limited here.

[0048] In a possible implementation, a plurality of light diffusing agents are provided in the diffusion layer 100. This example provides a volume diffusion method, in which a plurality of light diffusing agents are arranged in the diffusion layer 100 to enhance the light diffusion effect of the entire diffusion layer 100 and improve the light homogenization and mixing effect of the diffusion plate 30. During preparation, a plurality of light diffusing agents can be first added to the molten diffusion layer 100, and then the mixed melt is placed in a molding die for cooling and forming; alternatively, the molten diffusion layer 100 can be first placed in a molding die, and then a plurality of light diffusing agents are placed into the molten diffusion layer 100, stirred and mixed evenly, and then cooled and formed.

[0049] The light diffusing agent is a microsphere product obtained by using polymer polymerization technology through means such as crosslinking and grafting functional groups. It can be an inorganic light diffusing agent and an organic light diffusing agent. The inorganic light diffusing agent mainly includes solid microsphere balls such as nano barium sulfate, calcium carbonate, and silicon dioxide, allowing part of the light to pass through, and can adjust the light brightness and light transmission performance; the organic light diffusing agent mainly includes transparent or semi-transparent resins such as acrylic type, styrene type, and acrylic resin type, allowing most of the light to pass through, and can make the light soft.

[0050] In a possible implementation, the diffusion layer 100 and the light guide column 200 are integrally formed. Such a setting is convenient for processing and cost-saving; moreover, it can improve the overall strength of the diffusion plate 30 and extend the service life of the diffusion plate 30.

[0051] In a possible implementation, the material of the light guide column 200 is any one of polycarbonate, polymethyl methacrylate, epoxy resin, polyurethane, or polystyrene; and / or, the material of the diffusion layer 100 is any one of polycarbonate, polymethyl methacrylate, epoxy resin, polyurethane, or polystyrene. The light guide column 200 and the diffusion layer 100 provided in this example can be prepared from the same material. At this time, they can be integrally cast and formed using the same mold; alternatively, they can be separately formed using different molds and then connected and fastened by hot melt adhesive or the like. Of course, the light guide column 200 and the diffusion layer 100 can also be prepared from different materials. At this time, the molten material of the light guide column 200 can be poured into the molding die first. After the light guide column 200 is cooled and formed, the molten material of the diffusion layer 100 is then poured. After complete cooling, the diffusion plate 30 is demolded; or, they are separately formed using different molds and then connected and fastened by hot melt adhesive or the like. For example, but not limited to, the materials of both the light guide column 200 and the diffusion layer 100 are PC, PMMA, or PS.

[0052] In addition, as Figure 5As shown in the figure, the present application also provides a backlight module, which includes a backplane 10, at least one light source 20, and the diffusion plate 30 as described above. The light source 20 is disposed on the backplane 10, and the light guide column 200 of the diffusion plate 30 is disposed above the light source 20. For the specific structure of the diffusion plate 30, reference may be made to the above embodiments. Since this backlight module adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated herein one by one.

[0053] In this embodiment, the light source 20 may be an LED lamp, and multiple of them may be provided. The multiple LED light sources are arranged in an array on the backplane 10. At this time, multiple light guide columns 200 are provided on the diffusion layer 100 of the diffusion plate 30, and the multiple light guide columns 200 are arranged in an array, with one light guide column 200 corresponding to one LED light source; multiple avoidance grooves 300 are provided on the diffusion plate 30, and one avoidance groove 300 is correspondingly disposed on the incident surface 201 of one light guide column 200 to accommodate the corresponding LED light source. The backlight module provided in this example can achieve a local light homogenization effect, and the contrast of the display screen is high; moreover, the light homogenization and mixing effect of the diffusion plate 30 is good, and the display image quality is good; in addition, there is no light crosstalk problem between the diffusion plate 30 and the light source 20, and there is no smear problem in the dynamic display screen. The dynamic display screen is clear and the display effect is good.

[0054] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" as used herein may also include the plural forms. The terms "include", "comprise", "contain", and "have" are inclusive and thus specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the particular order described or illustrated, unless the order of performance is explicitly stated. It should also be understood that additional or alternative steps may be used.

[0055] Although the terms first, second, third, etc. may be used in the text to describe multiple elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, or section from another region, layer, or section. Unless the context clearly indicates otherwise, terms such as "first" and "second" and other numerical terms used in the text do not imply an order or sequence. Therefore, the first element, component, region, layer, or section discussed below may be referred to as the second element, component, region, layer, or section without departing from the teachings of the example embodiments.

[0056] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A diffusion plate is disposed above a back plate (10), and at least one light source (20) is provided on the back plate (10), characterized in that, The diffusion plate (30) includes a diffusion layer (100) and at least one light guide column (200) connected to the diffusion layer (100). The light guide column (200) is correspondingly arranged above the light source (20), and the refractive index of the light guide column (200) is greater than that of air. After the light beam emitted from the light source (20) undergoes total internal reflection in the light guide column (200), it is mixed with light by the diffusion layer (100) and emitted from the side of the diffusion layer (100) away from the light guide column (200).

2. The diffusion plate (30) according to claim 1, wherein The light guide column (200) includes an incident surface (201) and a plurality of total reflection surfaces (202) arranged around the periphery of the incident surface (201). The plurality of total reflection surfaces (202) extend in the same direction and are connected to the diffusion layer (100) to enclose a light diffusing surface on the diffusion layer (100). The projected area of the incident surface (201) on the diffusion layer (100) is accommodated within the light diffusing surface.

3. The diffusion plate (30) according to claim 2, wherein, The included angle (α) between the total reflection surface (202) and the diffusion layer (100) is 110° to 150°.

4. The diffusion plate (30) according to claim 2, characterized in that, A relief groove (300) is further provided on the incident surface (201). The relief groove (300) extends towards the diffusion layer (100) and is used to accommodate the light source (20).

5. The diffusion plate (30) according to claim 1, characterized in that, In the direction from the diffusion layer (100) to the light guide column (200), the thickness of the light guide column (200) is 3 mm to 8 mm; and / or, In the direction from the diffusion layer (100) to the light guide column (200), the thickness of the diffusion layer (100) is 0.5 mm to 3 mm.

6. The diffusion plate (30) according to claim 1, characterized in that, The haze of the diffusion layer (100) is 20% to 80%.

7. The diffusion plate (30) according to claim 6, characterized in that, The side of the diffusion layer (100) away from the light guide column (200) is a frosted surface; Alternatively, a plurality of light diffusing agents are provided in the diffusion layer (100).

8. The diffusion plate (30) according to claim 1, wherein, The diffusion layer (100) and the light guide column (200) are integrally formed.

9. The diffusion plate (30) according to claim 1, characterized in that, The material of the light guide column (200) is any one of polycarbonate, polymethyl methacrylate, epoxy resin, polyurethane or polystyrene; and / or, The material of the diffusion layer (100) is any one of polycarbonate, polymethyl methacrylate, epoxy resin, polyurethane or polystyrene.

10. A backlight module, characterized in that, It includes a back plate (10), at least one light source (20) and the diffusion plate (30) as described in any one of claims 1 to 9. The light source (20) is arranged on the back plate (10), and the light guide column (200) of the diffusion plate (30) is arranged above the light source (20).

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