Backlight module and manufacturing method thereof, and display device

Abstract

The present invention discloses a backlight module and a manufacturing method thereof, and a display device, which relate to the field of display technology, and include: a substrate, a light-emitting element arranged on one side of the substrate, and a diffusion plate arranged on the side of the light-emitting element away from the substrate; the orthographic projection of the light-emitting element on the plane where the substrate is located is located within the outer contour of the orthographic projection of the diffusion plate on the plane where the substrate is located; the diffusion plate includes a first surface and a second surface arranged opposite to each other along a first direction, the first surface is located on the side of the second surface facing the light-emitting element, and the first direction is perpendicular to the substrate; the backlight module includes a first area and a second area arranged around the first area, and in the first area, the first surface of the diffusion plate includes a first arc surface, and along the direction from the first surface to the second surface, the first arc surface is concave toward the second surface. This is conducive to improving the uniformity of the light emitted by the backlight module and improving the display effect.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and more specifically, to a backlight module and a manufacturing method thereof, and a display device. Background Art

[0002] With the evolution of optoelectronic and semiconductor technology, flat panel displays (Flat Panel Display) have also been vigorously developed. Various types of display panels are usually included in various devices such as current smart phones, notebooks, televisions and tablet personal computers, such as liquid crystal display (LCD, Liquid Crystal Display) panels, plasma display panels (PDP, Plasma Display Panel) and organic light-emitting diode (OLED, Organic Light-Emitting Diode) display panels. Such displays are generally flat and ultra-thin display devices, consisting of a large number of separately driven color pixels, which are placed in front of a light source or a reflector to produce an image. Among many flat panel displays, liquid crystal displays have been applied to various aspects of production and life due to their many superior characteristics such as high space utilization efficiency, low power consumption, no radiation and low electromagnetic interference. When liquid crystal display devices are mass-produced, it is inevitable that some process defects will cause uneven brightness of liquid crystal display devices, forming various types of Mura (Mura refers to the phenomenon that the brightness of the display device is uneven, causing various traces), resulting in poor display uniformity. Summary of the invention

[0003] In view of this, the present invention provides a backlight module and a manufacturing method thereof, and a display device, aiming to improve the uniformity of light output from the backlight module, thereby facilitating the display effect of the display device.

[0004] In a first aspect, the present invention provides a backlight module, comprising: a substrate, a light emitting element disposed on one side of the substrate, and a diffusion plate disposed on a side of the light emitting element away from the substrate;

[0005] The orthographic projection of the light emitting element on the plane where the substrate is located is located within the outer contour of the orthographic projection of the diffuser on the plane where the substrate is located;

[0006] The diffusion plate comprises a first surface and a second surface arranged opposite to each other along a first direction, the first surface is located on a side of the second surface facing the light emitting element, and the first direction is perpendicular to the substrate;

[0007] The backlight module includes a first area and a second area arranged around the first area. In the first area, the first surface of the diffusion plate includes a first curved surface, and the first curved surface is concave toward the second surface along the direction from the first surface to the second surface.

[0008] In a second aspect, the present invention further provides a display device, comprising the backlight module provided in the first aspect of the present invention.

[0009] In a third aspect, the present invention further provides a method for manufacturing a backlight module, which is used to manufacture the backlight module provided in the first aspect of the present invention, and the manufacturing method comprises:

[0010] providing a substrate;

[0011] A light emitting element is disposed on one side of the substrate;

[0012] A diffusion plate is provided on a side of the light emitting element away from the substrate;

[0013] Among them, the orthographic projection of the light-emitting element on the plane where the substrate is located is located within the outer contour of the orthographic projection of the diffuser on the plane where the substrate is located; the diffuser includes a first surface and a second surface arranged opposite to each other along a first direction, the first surface is located on the side of the second surface facing the light-emitting element, and the first direction is perpendicular to the substrate; the backlight module includes a first area and a second area arranged around the first area, and in the first area, the first surface of the diffuser includes a first curved surface, and along the direction from the first surface to the second surface, the first curved surface is recessed toward the second surface.

[0014] Compared with the prior art, the backlight module and the manufacturing method thereof, and the display device provided by the present invention achieve at least the following beneficial effects:

[0015] The backlight module and its manufacturing method and display device provided by the present invention include a substrate and a light-emitting element arranged on one side of the substrate, and a diffusion plate is arranged on the side of the light-emitting element away from the substrate, and the diffusion plate covers the light-emitting element on the substrate along the first direction. The second area of ​​the backlight module is arranged around the first area, the second area can be regarded as the edge area of ​​the backlight module, and the first area can be regarded as the area surrounded by the second area. When the light-emitting elements in the first area emit light, there may be a dark area between adjacent light-emitting elements. Therefore, the embodiment of the present invention improves the structure of the first surface of the diffusion plate in the first area, so that the first surface includes a first curved surface that is concave toward the second surface. The first curved surface constitutes a concave mirror structure. When the light emitted by the light-emitting element in the first area is emitted toward the first curved surface, the light emitted toward the first curved surface will be scattered, and more light will be emitted toward the light-emitting surface corresponding to the area between the adjacent light-emitting elements, thereby improving the problem of uneven brightness caused by the dark brightness of the light-emitting surface corresponding to the area between the adjacent light-emitting elements and the bright brightness of the light-emitting surface corresponding to the area of ​​the light-emitting element, which is conducive to improving the overall light uniformity of the backlight module, and further conducive to improving the display brightness uniformity of the display device.

[0016] Of course, any product implementing the present invention does not necessarily need to achieve all of the above-mentioned technical effects at the same time.

[0017] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0019] Figure 1 It is a schematic diagram of the light transmission principle of a direct-type backlight module in the related art;

[0020] Figure 2 FIG. 1 is a top view of a backlight module provided by an embodiment of the present invention;

[0021] Figure 3 Shown Figure 2 An AA cross-sectional view of the backlight module;

[0022] Figure 4 It is a light path diagram when the light passes through the concave mirror structure;

[0023] Figure 5 The figure shows a schematic diagram of the light path of the light emitted by the light emitting element in the backlight module after passing through the diffusion plate;

[0024] Figure 6 Shown Figure 2Another AA cross-sectional view of the backlight module;

[0025] Figure 7 Shown is a cross-sectional view of a diffusion plate in a backlight module provided by an embodiment of the present invention;

[0026] Figure 8 The figure shows a relative position relationship diagram of the diffusion plate and the light emitting element in the backlight module provided by the embodiment of the present invention;

[0027] Fig. 9 Shown is a top view of the relationship between transparent particles and light-emitting elements;

[0028] Fig.10 Another relative position relationship diagram of the diffusion plate and the light emitting element in the backlight module provided by the embodiment of the present invention is shown;

[0029] Fig.11 Shown is a schematic structural diagram of forming a first arc structure between adjacent light-emitting elements;

[0030] Fig.12 Shown is a schematic structural diagram of forming a first arc structure between adjacent light-emitting elements;

[0031] Fig.13 Another relative position relationship diagram of the diffusion plate and the light emitting element in the backlight module provided by the embodiment of the present invention is shown;

[0032] Fig.14 Another top view of the relationship between the diffuser plate and the light emitting element is shown;

[0033] Fig.15 Shown is a structural schematic diagram of a diffusion plate at a hollow position;

[0034] Fig.16 Shown Figure 2 Another AA cross-sectional view of the backlight module;

[0035] Fig.17 FIG. 1 is a schematic diagram of a structure of a display device provided by an embodiment of the present invention;

[0036] Fig.18 Shown Fig.17 A BB cross-sectional view of the display device;

[0037] Fig.19 Shown is a flow chart of a method for manufacturing a backlight module provided by an embodiment of the present invention;

[0038] Fig. 20 Shown is a flow chart of a method for manufacturing a diffusion plate in a backlight module provided by an embodiment of the present invention;

[0039] Fig.21 Another flow chart of a method for manufacturing a diffusion plate in a backlight module provided by an embodiment of the present invention is shown;

[0040] Fig. 22 FIG. 1 is another flow chart of a method for manufacturing a diffusion plate in a backlight module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0041] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0042] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0043] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0044] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0045] It is obvious to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Therefore, the present invention is intended to cover modifications and variations of the present invention that fall within the scope of the corresponding claims (technical solutions claimed for protection) and their equivalents. It should be noted that the implementation methods provided in the embodiments of the present invention can be combined with each other without contradiction.

[0046] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0047] Since the LCD panel itself does not emit light, it needs the light source provided by the backlight module to display images normally. Therefore, the backlight module becomes one of the key components of the LCD device. The backlight module is divided into two types according to the different incident positions of the light source: the side-entry backlight module and the direct-type backlight module. In the prior art, there is a direct-type backlight module, which uses an array-type LED surface light source, such as Figure 1 As shown, Figure 1It is a schematic diagram of the light transmission principle of a direct-type backlight module in the related technology. The starry sky Mura of the surface light source refers to the difference in the luminous flux values ​​of each luminous angle when the array-type LED point light source 00 emits light, resulting in a difference in the brightness B at the gap between the LED point light source 00 and the brightness A at the vertical point of the LED point light source 00. The luminous spectra at the two places are inconsistent, resulting in differences in visual brightness and chromaticity, causing the display device to have an uneven display problem as a whole.

[0048] Figure 2 FIG. 1 is a top view of a backlight module provided by an embodiment of the present invention. Figure 3 Shown Figure 2 An AA cross-sectional view of the backlight module, please refer to Figure 2 and Figure 3 , an embodiment of the present invention provides a backlight module 100, comprising: a substrate 11, a light emitting element 10 disposed on one side of the substrate 11, and a diffusion plate 20 disposed on a side of the light emitting element 10 away from the substrate 11;

[0049] The orthographic projection of the light emitting element 10 on the plane where the substrate 11 is located is located within the outer contour of the orthographic projection of the diffuser plate 20 on the plane where the substrate 11 is located;

[0050] The diffuser 20 includes a first surface M1 and a second surface M2 that are oppositely disposed along a first direction F1. The first surface M1 is located on a side of the second surface M2 that faces the light emitting element 10. The first direction F1 is perpendicular to the substrate 11.

[0051] The backlight module includes a first area A1 and a second area A2 arranged around the first area A1. In the first area A1, the first surface M1 of the diffuser 20 includes a first curved surface M01. The first curved surface M01 is concave toward the second surface M2 along the direction from the first surface M1 to the second surface M2.

[0052] It should be noted that Figure 2 The backlight module provided by the embodiment of the present invention is described by taking a rectangular backlight module as an example, but the actual shape of the backlight module is not limited. In some other embodiments of the present invention, the backlight module may also be circular, elliptical or other non-rectangular special-shaped structures. Figure 2 The light emitting elements 10 are arranged in an array on the substrate 11 as an example, and the arrangement of the light emitting elements 10 actually included in the backlight module is not limited. Figure 2 The light emitting element 10 having a rectangular structure in a top view is taken as an example for description, and the actual shape, size and number of the light emitting element 10 are not limited.

[0053] Continue to refer Figure 2 and Figure 3The backlight module 100 provided by the present invention includes a substrate 11 and a light-emitting element 10 arranged on one side of the substrate 11, and a diffusion plate 20 is arranged on the side of the light-emitting element 10 away from the substrate 11. Along the first direction F1, the diffusion plate 20 covers the light-emitting element 10 on the substrate 11, that is, the orthographic projection of the diffusion plate 20 on the substrate 11 covers the orthographic projection of each light-emitting element 10 on the substrate 11. The second area A2 of the backlight module is arranged around the first area A1. The second area A2 can be regarded as the edge area of ​​the backlight module, and the first area A1 can be regarded as the area surrounded by the second area A2. When the light-emitting element 10 in the first area A1 emits light, due to the difference in the luminous flux value of each light-emitting angle, there is a brightness difference between the area directly above the light-emitting element 10 and the area corresponding to the gap between adjacent light-emitting elements 10. There is more light and greater brightness directly above the light-emitting element 10; there is less light and lower brightness between adjacent light-emitting elements 10, and there is a dark area of ​​light. In other words, the brightness of the light emitted by the entire backlight module is uneven. When the backlight module is applied to a display device, the display device will have uneven display problems such as starry sky. Therefore, the embodiment of the present invention improves the structure of the first surface M1 of the diffuser 20 in the first area A1, so that the first surface M1 includes a first arc-shaped surface M01 that is concave toward the second surface M2. At this time, the first arc surface M01 forms a concave mirror structure. When the light emitted by the light emitting element 10 in the first area A1 is directed toward the first arc surface M01, the light deflection angle passing through the first arc surface M01 changes, and the light passing through the diffuser will be scattered. For example, please refer to Figure 4 and Figure 5 , the light path of the light vertically directed toward the first curved surface M01 changes after passing through the first curved surface M01, and part of the light in the vertical direction is directed from the direction of the large viewing angle, that is, in the backlight module, more light is directed toward the light-emitting surface corresponding to the gap between adjacent light-emitting elements 10, thereby improving the problem of uneven brightness caused by the dark brightness of the light-emitting surface corresponding to the area between adjacent light-emitting elements 10 and the bright brightness of the light-emitting surface corresponding to the area of ​​the light-emitting element 10, which is beneficial to improving the overall light uniformity of the backlight module. When the backlight module is applied to a display device, since the backlight module can provide a uniform surface light source to the display panel, it is beneficial to improve the display brightness uniformity of the display device, wherein, Figure 4 It is a light path diagram when the light passes through the concave mirror structure. Figure 5 FIG. 1 is a schematic diagram showing the optical path of the light emitted by the light emitting element 10 in the backlight module after passing through the diffusion plate 20 .

[0054] Optionally, in the backlight module provided in the embodiment of the present invention, the light-emitting element is a miniLED or a MicroLED.

[0055] In an optional embodiment of the present invention, the diffusion plate 20 includes transparent glass, transparent metal material (such as indium tin oxide) or transparent ceramic material.

[0056] In the related art, the diffuser plate 20 of the backlight module is usually made of a material with low transmittance such as PMMA (polymethyl methacrylate). The transmittance of the diffuser plate 20 made of such a material is usually around 45%, which limits the light output brightness of the backlight module and is not conducive to the effective use of the light emitted by the light-emitting element 10.

[0057] In the backlight module provided in the embodiment of the present invention, when the diffusion plate 20 is made of transparent glass, transparent metal material or transparent ceramic material, the transmittance can reach 85% or above, which can effectively improve the utilization rate of the light emitted by the light-emitting element 10, so that more light is emitted from the diffusion plate 20. When the backlight module is applied to a display device, it is beneficial to improve the overall brightness of the display device.

[0058] In addition, compared with the diffuser plate 20 made of PMMA and other materials in the related art, the present application uses transparent glass, transparent metal material or transparent ceramic material to make the diffuser plate 20, which is beneficial to reducing the overall thickness of the diffuser plate 20. The thickness of the diffuser plate in the related art is usually around 1.5 mm, while the thickness of the diffuser plate made of the above materials in the present invention does not exceed 1 mm, which is beneficial to reducing the overall thickness of the backlight module. When the backlight module with a smaller thickness is applied to the display device, it is beneficial to reduce the overall thickness of the display device and realize the thin design of the display device.

[0059] Continue to refer Figure 3 In an optional embodiment of the present invention, in the second area A2, the first surface M1 of the diffusion plate 20 is a planar structure parallel to the plane where the substrate 11 is located.

[0060] Taking the backlight module as a rectangular structure as an example, assuming that the backlight module includes a plurality of light-emitting elements 10 arranged in an array, the light-emitting elements 10 corresponding to the second area A2 can be regarded as the light-emitting elements 10 located in the outermost circle of the backlight module, and the light-emitting elements 10 corresponding to the second area A2 can be regarded as other light-emitting elements 10 surrounded by the outer circle of light-emitting elements 10. The light-emitting elements 10 located in the second area A2 are located at the outermost periphery of the backlight module. If a concave mirror structure is used to diffuse the light emitted by this part of the light-emitting elements 10, a part of the light will be emitted to the border area of ​​the backlight module, and may not be emitted from the light-emitting surface of the backlight module, so the effective utilization rate of the light of the light-emitting elements 10 in the second area A2 may be reduced. Therefore, the embodiment of the present invention has a differentiated design for the structure of the diffuser 20 located in the first area A1 and the second area A2. In the first area A1, the surface of the diffuser 20 is a concave mirror structure, so that the light emitted by the light-emitting elements 10 located in the first area A1 can be scattered, and the star-filled phenomenon of the light emitted by the backlight module can be weakened. The surface of the diffuser plate 20 in the second area A2 is set to be parallel to the plane where the substrate 11 is located. When the second light-emitting element 10 located in the second area A2 passes through the diffuser plate 20 with a planar structure, the amount of light emitted by the light-emitting element 10 in the second area A2 that is emitted toward the border area of ​​the backlight module can be reduced or avoided, so that the light emitted by the second light-emitting element 10 in the second area A2 is emitted from the light-emitting surface corresponding to the second area A2 as much as possible, which is beneficial to improving the effective utilization rate of the light emitted by the light-emitting element 10 in the second area A2, and is beneficial to ensuring the luminous brightness of the edge area of ​​the backlight module, so as to improve the overall display brightness uniformity of the display device when the backlight module is applied to the display device.

[0061] Continue to refer Figure 3 In an optional embodiment of the present invention, the orthographic projection of the first arc-shaped surface M01 on the plane where the substrate 11 is located covers the orthographic projection of each light-emitting element 10 located in the first area A1 on the plane where the substrate 11 is located.

[0062] Specifically, when the first surface M1 of the diffuser 20 facing the light-emitting element 10 includes a first curved surface M01, the first curved surface M01 can be regarded as the entire first surface M1 in the first area as a curved structure, that is, in the position of the entire first area A1, the first surface M1 as a whole can be regarded as a concave mirror structure that is concave toward the second surface M2. In this way, when the light emitted by the light-emitting element 10 in the first area A1 is directed toward the first curved surface M01 of the concave mirror structure, the light emitted by each light-emitting element 10 in the first area A1 can be scattered by the concave mirror structure, and part of the light originally emitted from the area directly above the light-emitting element 10 is directed toward the area between two adjacent light-emitting elements 10, so as to reduce the brightness difference between the area directly above the light-emitting element 10 and the area between the adjacent light-emitting elements 10, which is equivalent to homogenizing the light emitted by the first light-emitting element 10 in the first area A1, thereby effectively improving the uniformity of the light emitted by the light-emitting element 10 in the first area A1. When the backlight module with such a structure is applied to a display device, it is helpful to improve the overall display uniformity of the display device.

[0063] The above embodiment shows a scheme in which the first surface M1 of the diffuser plate 20 is set as a concave mirror structure and the second surface M2 is set as a planar structure. In some other embodiments of the present invention, the structure of the second surface M2 of the diffuser plate 20 can also be embodied in other ways, for example, please refer to Figure 6 and Figure 7 .

[0064] Figure 6 Shown Figure 2 Another AA cross-sectional view of the backlight module. Figure 7 FIG. 2 is a cross-sectional view of a diffuser plate 20 in a backlight module provided in an embodiment of the present invention. Figure 6 and Figure 7 In an optional embodiment of the present invention, the second surface M2 includes a second arcuate surface M02, and along the direction of the second surface M2 pointing to the first surface M1, the second arcuate surface M02 is concave toward the first surface M1.

[0065] Specifically, in the backlight module provided by the embodiment of the present invention, in addition to setting the first surface M1 of the diffuser 20 facing the light-emitting element 10 to include a first curved surface M01, the second surface M2 of the diffuser 20 facing away from the light-emitting element 10 can also be set to include a second curved surface M02, and the second curved surface M02 is concave toward the first surface M1, so that the second surface M2 of the diffuser 20 also presents a concave mirror structure. When the light emitted by the light-emitting element 10 in the first area A1 is emitted to the first curved surface M01 of the concave mirror structure, the light is scattered for the first time; when the scattered light passes through the second curved surface M02 of the concave mirror structure, the light is scattered again and then emitted. After the light emitted by the light-emitting element 10 in the first area A1 passes through the surface of the two concave mirror structures of the diffuser 20, the light will be scattered more evenly, which is more conducive to reducing the brightness difference of the area directly above the light-emitting element 10 and the area between adjacent light-emitting elements 10, improving the overall light uniformity of the backlight module, and avoiding the occurrence of the starry sky phenomenon.

[0066] Continue to refer Figure 6 and Figure 7 In an optional embodiment of the present invention, in the first area A1, the minimum thickness of the diffuser plate 20 is D1, wherein D1 ≥ 0.2 mm, and D1 is less than the thickness of the diffuser plate 20 in the first area A1.

[0067] Specifically, in the backlight module provided by the embodiment of the present invention, the minimum thickness of the diffuser plate 20 is the thickness corresponding to the bottom position of the concave mirror. If the minimum thickness is set too small, for example, less than 0.2 mm, the diffuser plate 20 may be deformed due to uneven force, affecting the uniformity of the overall light output. When the minimum thickness of the diffuser plate 20 is set to be greater than or equal to 0.2 mm in the present application, it can ensure that the diffuser plate 20 still maintains a certain rigidity in its thinnest area, avoiding deformation caused by uneven force, thereby facilitating the overall uniformity of the light output of the backlight module. In addition, when the minimum thickness of the diffuser plate 20 in the second area A2 is set to be less than the thickness of the diffuser plate 20 in the first area A1 in the present application, the thickness of the diffuser plate 20 will depend on the thickness of the diffuser plate 20 in the first area A1, and the thickness of the diffuser plate 20 in the first area A1 will not affect the overall thickness of the diffuser plate 20, thereby facilitating the thinning design of the diffuser plate 20 and the thinning design of the backlight module. Optionally, 0.2 mm ≤ D1 ≤ 0.5 mm.

[0068] Optionally, the thickness of the diffusion plate 20 increases in a direction from the central area of ​​the first area A1 to the second area A2.

[0069] Continuing to refer to the figure, in an optional embodiment of the present invention, in the second area A2, the thickness of the diffusion plate 20 is D0, wherein 0.5 mm≤D0≤1 mm.

[0070] Specifically, when the first area A1 of the diffuser plate 20 is set to a concave mirror structure and the second area A2 is set to a plane structure, the thickest area of ​​the diffuser plate 20 as a whole is located in the second area A2. If the thickness of the second area A2 is set to be less than 0.5mm, the overall thickness of the diffuser plate 20 is too thin, and it is easy to deform due to uneven force, affecting the uniformity of light output. If the thickness of the second area A2 is set to be greater than 1mm, the thickness of the diffuser plate 20 is relatively large, which is not conducive to achieving a thin design. Therefore, the embodiment of the present invention sets the thickness of the diffuser plate 20 in the second area A2 to 0.5mm≤D0≤1mm, which is conducive to achieving an overall thin design of the diffuser plate 20 while ensuring that the diffuser plate 20 has a certain rigidity and is not easy to deform. Optionally, 0.6mm≤≤0.8mm.

[0071] The thickness of the diffuser plate 20 in the related art is above 1 mm, for example, about 1.5 mm. The embodiment of the present invention can control the maximum thickness of the diffuser plate 20 to 1 mm or less. Compared with the related art, the overall thickness of the diffuser plate 20 can be reduced, thereby realizing the overall thin design of the backlight module and the display device.

[0072] Figure 8 The figure shows a relative position relationship diagram of the diffusion plate 20 and the light emitting element 10 in the backlight module provided by the embodiment of the present invention. This embodiment shows a solution of filling transparent particles 21 in the diffusion plate 20 .

[0073] In an optional embodiment of the present invention, the diffuser 20 includes a substrate; in the first area A1, a plurality of transparent particles 21 are filled in the substrate, and along the first direction, the transparent particles 21 overlap with the light-emitting elements 10 and do not overlap with the gaps X between adjacent light-emitting elements 10, and the refractive index of the transparent particles 21 is not equal to the refractive index of the substrate.

[0074] Specifically, in the diffuser plate 20 provided in the embodiment of the present invention, transparent particles 21 are filled in the area facing the light emitting element 10, and the refractive index of the transparent particles 21 is different from the refractive index of the matrix of the diffuser plate 20. When the light emitted by the light emitting element 10 is directed to the first surface M1 of the concave mirror structure of the diffuser plate 20, the light originally in the vertical direction is diffused in the direction of a large viewing angle. When this part of the light is further directed to the transparent particles 21, since the refractive index of the transparent particles 21 is different from the refractive index of the matrix, the above light will be further deflected in the direction of a large angle, so that more light emitted by the light emitting element 10 is directed to the area between adjacent light emitting elements 10. The deflection effect of the transparent particles 21 on the light increases the amount of light directed to the area between adjacent light emitting elements 10, so it is more conducive to balancing the amount of light corresponding to the area directly above the light emitting element 10 and between the adjacent light emitting elements 10, and is therefore more conducive to improving the uniformity of the light emitted by the backlight module.

[0075] In addition, in the embodiment of the present invention, transparent particles 21 are not arranged on the diffuser 20 at a position directly above the gap X between two adjacent light-emitting elements 10 to prevent light emitted to the area between the adjacent light-emitting elements 10 from being deflected by the transparent particles 21 and emitted to other positions, thereby facilitating ensuring the amount of light between the adjacent light-emitting elements 10.

[0076] Fig. 9 The figure shows a top view of the relationship between the transparent particles 21 and the light emitting element 10. Figure 8 and Fig. 9 In an optional embodiment of the present invention, along the first direction, the same light-emitting element 10 overlaps with at least two transparent particles 21 .

[0077] Specifically, the more transparent particles 21 that overlap with the light-emitting element 10, the more light will be deflected to the area between adjacent light-emitting elements 10 through the transparent particles 21. Therefore, the method of arranging at least two transparent particles 21 in the light-emitting direction of each light-emitting element 10 in the embodiment of the present invention is more conducive to breaking up the light emitted by the light-emitting element 10, so that the light emitted through the diffuser 20 will be more uniform.

[0078] Optionally, the number of transparent particles corresponding to each light-emitting element is the same or substantially the same, which helps to improve the consistency of the light deflection effect of the transparent particles, thereby improving the uniformity of the light emitted by the light-emitting elements in different areas.

[0079] In an optional embodiment of the present invention, the transparent particles 21 include at least one of bubbles, SiO, SiN, and PEDOT. The refractive index of these materials is different from that of the substrate. When the light is directed to the transparent particles, the light path is deflected, and more light can be directed to the position corresponding to the gap between adjacent light-emitting elements, so as to increase the luminous brightness corresponding to the gap and improve the starry sky phenomenon.

[0080] Fig.10 FIG. 1 is another relative position relationship diagram of the diffusion plate 20 and the light emitting element 10 in the backlight module provided by the embodiment of the present invention.

[0081] Please refer to Fig.10 In an optional embodiment of the present invention, the first area A1 includes a first sub-area Q1 and a second sub-area Q2, the orthographic projection of the light-emitting element 10 on the plane where the substrate 11 is located is located in the first sub-area Q1, and the orthographic projection of the gap X between adjacent light-emitting elements 10 on the plane where the substrate 11 is located is located in the second sub-area Q2; in the second sub-area Q2, a first arc-shaped structure 22 is provided on the first arc-shaped surface M01 of the diffuser 20, and the first arc-shaped structure 22 is recessed along the surface of the first arc-shaped surface M01 toward the second surface M2.

[0082] Specifically, among the light emitted by the light-emitting element 10, when a part of the light is emitted to the diffuser 20 just above the gap between the adjacent light-emitting elements 10, since the diffuser 20 is provided with a first arc structure 22 in this partial area, the first arc structure 22 can adjust the incident angle of the light, so that among the light transmitted in the corresponding area of ​​the gap between the adjacent light-emitting elements 10, the light with a smaller viewing angle can be emitted in the direction of a larger viewing angle, thereby homogenizing the light in the corresponding area of ​​the gap, which not only increases the amount of light in the corresponding area of ​​the gap, but also helps to improve the brightness uniformity of the corresponding area of ​​the gap.

[0083] Fig.11 It is a schematic diagram of a structure in which a first arc structure 22 is formed between adjacent light emitting elements 10 . This embodiment shows the corresponding relationship between the light emitting elements 10 in different regions and the first arc structure 22 .

[0084] Please refer to Fig.11 In an optional embodiment of the present invention, the light-emitting elements 10 are arranged in an array on the substrate 11, the area between two adjacent columns of light-emitting elements 10 is the first gap X1, and the area between two adjacent rows of light-emitting elements 10 is the second gap X2, and the first arc structure 22 is provided in both the first gap X1 and the second gap X2.

[0085] Specifically, this embodiment shows a solution in which a first arc structure 22 is set in the gaps between adjacent light-emitting elements 10 along the row direction and the areas corresponding to the gaps between adjacent light-emitting elements 10 along the column direction. Through the adjustment effect of the first arc structure 22 on light, more light of the central angle of view in the areas corresponding to the gaps is emitted in the direction of the wide angle of view. Moreover, when the first arc structure 22 is set in the areas corresponding to the gaps between any adjacent light-emitting elements 10, the amount of light in the areas corresponding to the gaps is more uniform, which is beneficial to reducing the problem of uneven brightness that may occur in areas corresponding to different gaps, and is therefore beneficial to improving the overall uniformity of light emitted by the backlight module.

[0086] Fig.11 The embodiment shown shows that the first arc structure 22 is provided in the area corresponding to each gap, and the first arc structures 22 corresponding to different areas are independent of each other. In some other embodiments of the present invention, the first arc structure 22 can also be embodied in other forms, for example, please refer to Fig.12 .

[0087] Fig.12 The figure shows a schematic diagram of a structure in which a first arc structure 22 is formed between adjacent light emitting elements 10. In this embodiment, the first arc structure 22 is arranged to pass through the gap between two adjacent columns / rows of light emitting elements 10 of the entire backlight module.

[0088] Please refer to Fig.12 In an optional embodiment of the present invention, in the first gap X1, the first arc structure 22 extends along the extension direction of the first gap X1, and the same first arc structure 22 corresponds to each light-emitting element 10 in two adjacent columns of light-emitting elements 10; in the second gap X2, the first arc structure 22 extends along the extension direction of the second gap X2, and the same first arc structure 22 corresponds to each light-emitting element 10 in two adjacent rows of light-emitting elements 10.

[0089] Specifically, in this embodiment, two adjacent columns of light emitting elements 10 share a plurality of first arc structures 22, and along the extension direction of the first gap X1, the length of the first arc structure 22 is greater than or equal to the total length of the gaps between the two adjacent columns of light emitting elements 10. Moreover, two adjacent rows of light emitting elements 10 share a plurality of first arc structures 22, and along the extension direction of the second gap X2, the length of the first arc structure 22 is greater than or equal to the total length of the gaps between the two adjacent rows of light emitting elements 10. In this way, by making one or more long strips of the first arc structure 22 in the gap between the two adjacent columns of light emitting elements 10, the emission angle of the light emitted by the two adjacent columns of light emitting elements 10 can be adjusted, and there is no need to make different first arc structures 22 for the gaps between each adjacent light emitting element 10, which is conducive to simplifying the overall manufacturing process of the arc structure and improving the production efficiency of the diffuser plate 20 and the backlight module. Similarly, by making one or more long strips of first arc structures 22 in the gap between two adjacent rows of light-emitting elements 10, the emission angle of the light emitted by the two adjacent rows of light-emitting elements 10 can be adjusted, without having to make different first arc structures 22 for the gaps between each adjacent light-emitting element 10. This is also beneficial for simplifying the overall manufacturing process of the arc structure and improving the production efficiency of the diffuser plate 20 and the backlight module.

[0090] Optionally, at least two first arc structures 22 can be set in the gap between two adjacent rows of light-emitting elements 10, and at least two first arc structures 22 can be set in the gap between two adjacent columns of light-emitting elements 10. By adjusting the light emission direction through multiple arc structures, it is more conducive to improving the uniformity of light in the gap between adjacent light-emitting elements 10, thereby helping to improve the overall light emission uniformity of the backlight module.

[0091] Optionally, the first arc-shaped structure 22 may be formed by etching.

[0092] Fig.13 FIG. 2 is another relative position relationship diagram of the diffusion plate 20 and the light emitting element 10 in the backlight module provided by the embodiment of the present invention. Fig.14 FIG. 1 is another top view showing the relationship between the diffuser plate 20 and the light emitting element 10 .

[0093] Please refer to Fig.13 and Fig.14 In an optional embodiment of the present invention, in the first area A1, the diffuser plate 20 includes a plurality of hollows 24, and along the first direction F1, the hollows 24 penetrate the diffuser plate 20, and the orthographic projection of the hollows 24 on the plane where the substrate 11 is located is located in the gap between adjacent light-emitting elements 10 within the orthographic projection range of the plane where the substrate 11 is located.

[0094] Specifically, in this embodiment, a hollow 24 is formed on the diffuser plate 20, and the hollow 24 is set in the area just above the gap between adjacent light-emitting elements 10. After the light emitted by the light-emitting element 10 is diffused by the arc surface of the diffuser plate 20, a part of the light is emitted from the diffuser plate 20 from the direction of the wide viewing angle; among the light emitted by the light-emitting element 10, another part of the light is directly emitted to the position corresponding to the hollow 24 and emitted from the area corresponding to the hollow 24. The light at the hollow 24 position is unobstructed, so the light emitted from the hollow 24 will not suffer light loss, so the amount of light in the area corresponding to the hollow 24, that is, the area just above the area between adjacent light-emitting elements 10, can be increased, which is conducive to balancing the difference in the amount of light in the area just above the light-emitting element 10 and the area just above the area corresponding to the area between adjacent light-emitting elements 10, thereby helping to improve the overall uniformity of the light emitted by the backlight module. When the base material of the diffuser plate is glass, the transmittance of glass is generally 92%. If a hollow is formed between adjacent light-emitting elements, there is no light loss in the hollow, and the transmittance can be optimized by 8%.

[0095] Optionally, Fig.15 The figure shows a structural schematic diagram of a diffusion plate at a hollow position. At the hollow position, the side wall of the diffusion plate adjacent to the hollow is embodied as an outwardly convex arc structure, which protrudes toward the hollow position to form a convex lens structure. The focusing of the convex lens is far away, so that large-angle light is more concentrated at the hollow position, thereby allowing more light to be emitted from the position corresponding to the hollow, which is more conducive to increasing the amount of light at the position corresponding to the gap of the light-emitting element, and is more conducive to improving the problem of uneven display of the backlight module.

[0096] Continue to refer Fig.14 In an optional embodiment of the present invention, in the first area A1, a hollow 24 is provided on a side of the gap between any two adjacent light emitting elements 10 facing the diffusion plate 20.

[0097] Specifically, when the hollows 24 are provided in the areas of the diffuser plate 20 corresponding to the gaps between any two adjacent light-emitting elements 10, most of the light emitted by the light-emitting element 10 at a wide viewing angle can be emitted through the hollows 24, and there is no light loss at the hollows 24, which is conducive to improving the light transmittance of the area corresponding to the gaps between any adjacent light-emitting elements 10 in the backlight module, and improving the amount of light in the area corresponding to the above gaps. In addition, since part of the light emitted by the light-emitting element 10 will be emitted to the area corresponding to the gaps between adjacent light-emitting elements 10 after passing through the diffuser plate 20 with a concave mirror structure, thereby further improving the amount of light in the area corresponding to the above gaps, it is conducive to balancing the brightness difference between the area corresponding to the light-emitting element 10 and the area corresponding to the gaps, eliminating or reducing the starry sky problem of the backlight module, and improving the overall uniformity of the light emitted by the backlight module.

[0098] Fig.16 Shown Figure 2 Another AA cross-sectional view of the backlight module. Optionally, other optical film layers, such as a diffusion film 30, are provided on the side of the diffuser plate 20 away from the substrate 11. The function of the diffusion film 30 is to further disperse the light emitted from the diffuser plate 20, thereby further improving the light uniformity of the backlight module. The diffusion film 30 is usually thin, for example, about 100 μm, which is much thinner than the diffuser plate 20 (for example, 0.5 mm thick) provided in the embodiment of the present invention. Optionally, in actual production, one or more layers of the diffusion film 30 can be provided according to actual needs, and the present invention does not specifically limit this.

[0099] Optionally, other optical films, such as a first prism film 41 and a second prism film 42, may be disposed on the side of the diffusion film 30 away from the diffusion plate 20. Optionally, the extension directions of the prisms of the first prism film 41 and the second prism film 42 are orthogonal, and the second prism film 42 is located between the first prism film 41 and the diffusion plate 20. By utilizing the principle of refraction and total reflection of light by the prisms in the prism film, the arrangement of the two layers of prism film is conducive to increasing the utilization rate of the light incident on the prism film. Among the light incident on the first prism film 41 and the second prism film 42, at least part of the light is reused after being reflected by the prism structure, thereby improving the effective utilization rate of the light, which is conducive to improving the light output brightness of the backlight module.

[0100] Optionally, a dual-brightness enhancing film 50 may be provided on the side of the second prism film 42 away from the first prism film 41. The dual-brightness enhancing film 50 may be regarded as a reflective polarizer, which selectively reflects the light of the light-emitting element 10 in the backlight module so that the light that may not be transmitted to the light-emitting surface of the backlight module can be reused. In combination with the first prism film 41 and the second prism film 42, it is beneficial to further improve the light-emitting brightness of the backlight module. When the backlight module is applied to a display device, it is beneficial to improve the display brightness of the display device.

[0101] Fig.17 FIG. 1 is a schematic diagram of a structure of a display device provided by an embodiment of the present invention. Fig.18 Shown Fig.17 A BB cross-sectional view of the display device, please refer to Fig.17 and Fig.18 Based on the same inventive concept, the present invention further provides a display device 300 , including a display panel 200 and the backlight module 100 provided in the above embodiment of the present invention, wherein the display panel 200 is located in the light emitting direction of the backlight module 100 .

[0102] Since the backlight module provided by the embodiment of the present invention increases the light output of the light emitting element at a large viewing angle through the diffusion plate, the difference in light emitting brightness between the area directly above the light emitting element and the area corresponding to the gap between the light emitting elements is reduced, thereby improving the overall light output uniformity of the backlight module. When the backlight module is applied to a display device, it is helpful to improve the display unevenness problem such as starry sky that may occur in the display device, so it is helpful to improve the overall display uniformity of the display device.

[0103] It is understandable that the display device provided in the embodiment of the present invention may be a mobile phone, tablet, computer, television, vehicle-mounted display device or other display device with display function, and the present invention does not specifically limit this. The display device provided in the embodiment of the present invention has the beneficial effects of the anti-peeping display module provided in the embodiment of the present invention. For details, please refer to the specific description of the anti-peeping display module in the above embodiments, and this embodiment will not be repeated here.

[0104] Based on the same inventive concept, the present invention also provides a method for manufacturing a backlight module. Fig.19 FIG. 1 is a flow chart of a method for manufacturing a backlight module provided in an embodiment of the present invention. Figure 3 and Fig.19 , the manufacturing method of the backlight module includes:

[0105] S1. Provide a substrate;

[0106] S2, disposing a light emitting element on one side of the substrate;

[0107] S3, disposing a diffusion plate on the side of the light emitting element away from the substrate;

[0108] Among them, the orthographic projection of the light-emitting element on the plane where the substrate is located is located within the outer contour of the orthographic projection of the diffusion plate on the plane where the substrate is located; the diffusion plate includes a first surface and a second surface arranged opposite to each other along a first direction, the first surface is located on the side of the second surface facing the light-emitting element, and the first direction is perpendicular to the substrate; the backlight module includes a first area and a second area arranged around the first area, in the first area, the first surface of the diffusion plate includes a first curved surface, and along the direction from the first surface to the second surface, the first curved surface is concave toward the second surface.

[0109] Specifically, in the backlight module formed by the embodiment of the present invention, the structure of the first surface M1 of the diffuser 20 in the first area A1 is improved, so that the first surface M1 includes a first curved surface M01 that is concave toward the second surface M2. At this time, the first curved surface M01 constitutes a concave mirror structure, and when the light emitted by the light-emitting element 10 in the first area A1 is directed toward the first curved surface M01, the light deflection angle of the light passing through the first curved surface M01 changes, and the light passing through the diffuser will be scattered. After the light vertically directed toward the first curved surface M01 passes through the first curved surface M01, the light path changes, and a part of the light in the vertical direction is emitted from the direction of the large viewing angle, that is, in the backlight module, more light is directed toward the light-emitting surface corresponding to the gap between adjacent light-emitting elements 10, thereby improving the problem of uneven brightness caused by the dark brightness of the light-emitting surface corresponding to the area between the adjacent light-emitting elements 10 and the bright brightness of the light-emitting surface corresponding to the area of ​​the light-emitting element 10, which is conducive to improving the overall light uniformity of the backlight module.

[0110] Fig. 20 FIG. 1 is a flow chart of a method for manufacturing a diffusion plate in a backlight module provided in an embodiment of the present invention. Please refer to FIG. Fig. 20 In an optional embodiment of the present invention, a method for manufacturing a diffusion plate in a backlight module includes:

[0111] S01. Injecting molten liquid into a mold; optionally, the molten liquid is a molten liquid corresponding to transparent glass, transparent metal material or transparent ceramic material.

[0112] S02. Drop transparent particles into at least a partial area of ​​the molten liquid.

[0113] S03, injection molding.

[0114] In the backlight module provided by the embodiment of the present invention, when the molten liquid is used to make the base of the diffusion plate, due to the high density and poor fluidity of the molten liquid, the molten liquid can be used to make a structure with it, thereby simplifying the manufacturing process of the diffusion plate. When making the diffusion plate, the transparent particles formed in the molten liquid in the embodiment of the present invention, when the diffusion plate is applied to the backlight module, please refer to Figure 8, along the first direction, the transparent particles 21 overlap with the light emitting element 10, and do not overlap with the gap X between adjacent light emitting elements, and the transparent refractive index is not equal to the refractive index of the substrate. When the light emitted by the light emitting element 10 is directed to the first surface M1 of the concave mirror structure of the diffuser plate 20, the light originally in the vertical direction is diffused in the direction of a large viewing angle. When this part of the light is further directed to the transparent particles 21, due to the difference between the refractive index of the transparent particles 21 and the refractive index of the substrate, the above light will be further deflected in the direction of a large angle, so that more light emitted by the light emitting element 10 is directed to the area between adjacent light emitting elements 10. The deflection effect of the transparent particles 21 on the light increases the amount of light directed to the area between adjacent light emitting elements 10, so it is more conducive to balancing the amount of light corresponding to the area directly above the light emitting element 10 and between adjacent light emitting elements 10, and therefore it is more conducive to improving the uniformity of the light emitted by the backlight module.

[0115] Optionally, the transparent particles 21 may be particles formed of SiO, SiN or PEDOT, for example.

[0116] Fig.21 FIG. 1 is another flow chart of a method for manufacturing a diffusion plate in a backlight module provided in an embodiment of the present invention. Please refer to FIG. Fig.21 In an optional embodiment of the present invention, after transparent particles are dripped into at least a part of the melt and before injection molding, the method further comprises:

[0117] S04, after the molten liquid solidifies, injecting the molten liquid into the mold again;

[0118] S05. Drop transparent particles into at least a partial area of ​​the re-injected molten liquid.

[0119] When using the diffuser in a backlight unit, please continue to refer to Figure 8 , along the first direction, the re-formed transparent particles 21 overlap with the light emitting elements 10, and do not overlap with the gaps between the light emitting elements 10, that is, the re-formed transparent particles are also arranged directly above the light emitting elements. By dripping transparent particles again, the number of transparent particles arranged directly above the light emitting elements is increased, which is beneficial to increase the amount of light emitted to the area corresponding to the gaps between the light emitting elements, and is more beneficial to improve the uniformity of the light emitted by the backlight module.

[0120] It should be noted that, in actual production, the number of times of dropping transparent particles can be determined according to actual needs. This embodiment only takes the example of forming transparent particles twice in the substrate, and does not limit the actual number.

[0121] Fig. 22FIG. 1 is another flow chart of a method for manufacturing a diffusion plate in a backlight module provided in an embodiment of the present invention. Please refer to FIG. Fig. 22 In an optional embodiment of the present invention, after injection molding, the process further includes step S06 of forming a first arc-shaped structure on the first surface of the diffuser plate, for example, referring to Fig.10 , wherein the method of forming the first arc-shaped structure includes a frosting process or a sandblasting process;

[0122] The frosting process includes: using an acidic liquid to corrode at least a portion of the first surface of the diffusion plate to form a first arc-shaped structure on the first surface;

[0123] The sandblasting process includes: using sand particles ejected from a spray gun to strike at least a portion of the first surface of the diffusion plate to form a first arc-shaped structure on the first surface.

[0124] Specifically, a first arc structure is formed on the first surface of the diffuser plate through the above-mentioned frosting process or sandblasting process. When the diffuser plate is applied to the backlight module, the first arc structure is located in the area directly above the gap between the light-emitting elements. Among the light emitted by the light-emitting element 10, when a part of the light is emitted to the diffuser plate 20 directly above the gap between the adjacent light-emitting elements 10, since the diffuser plate 20 is provided with the first arc structure 22 in this part of the area, the first arc structure 22 can adjust the incident angle of the light, so that among the light transmitted in the area corresponding to the gap between the adjacent light-emitting elements 10, the light with a smaller viewing angle can be emitted in the direction of a larger viewing angle, thereby homogenizing the light in the area corresponding to the gap, which not only increases the amount of light in the area corresponding to the gap, but also helps to improve the brightness uniformity of the area corresponding to the gap.

[0125] In some other embodiments of the present invention, a layer such as the following can be formed in the area just above the gap between adjacent light emitting elements by etching: Fig.13 and Fig.14 The hollowing out shown is to further increase the light flux in the gap.

[0126] It can be seen from the above embodiments that the backlight module and the manufacturing method thereof, and the display device provided by the present invention achieve at least the following beneficial effects:

[0127] The backlight module and its manufacturing method and display device provided by the present invention include a substrate and a light-emitting element arranged on one side of the substrate, and a diffusion plate is arranged on the side of the light-emitting element away from the substrate, and the diffusion plate covers the light-emitting element on the substrate along the first direction. The second area of ​​the backlight module is arranged around the first area, the second area can be regarded as the edge area of ​​the backlight module, and the first area can be regarded as the area surrounded by the second area. When the light-emitting elements in the first area emit light, there may be a dark area between adjacent light-emitting elements. Therefore, the embodiment of the present invention improves the structure of the first surface of the diffusion plate in the first area, so that the first surface includes a first curved surface that is concave toward the second surface. The first curved surface constitutes a concave mirror structure. When the light emitted by the light-emitting element in the first area is emitted toward the first curved surface, the light emitted toward the first curved surface will be scattered, and more light will be emitted toward the light-emitting surface corresponding to the area between the adjacent light-emitting elements, thereby improving the problem of uneven brightness caused by the dark brightness of the light-emitting surface corresponding to the area between the adjacent light-emitting elements and the bright brightness of the light-emitting surface corresponding to the area of ​​the light-emitting element, which is conducive to improving the overall light uniformity of the backlight module, and further conducive to improving the display brightness uniformity of the display device.

[0128] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A backlight module, characterized in that: include: A substrate, a light emitting element disposed on one side of the substrate, and a diffusion plate disposed on a side of the light emitting element away from the substrate; The orthographic projection of the light emitting element on the plane where the substrate is located is located within the outer contour of the orthographic projection of the diffuser on the plane where the substrate is located; The diffusion plate comprises a first surface and a second surface arranged opposite to each other along a first direction, the first surface is located on a side of the second surface facing the light emitting element, and the first direction is perpendicular to the substrate; The backlight module includes a first area and a second area arranged around the first area. In the first area, the first surface of the diffusion plate includes a first arc surface. In the direction from the first surface to the second surface, the first arc surface is concave toward the second surface. In the first area, the diffusion plate includes a plurality of hollows, which penetrate the diffusion plate along the first direction, and the orthographic projection of the hollows on the plane where the substrate is located is within the orthographic projection range of the gaps between adjacent light-emitting elements on the plane where the substrate is located.

2. The backlight module according to claim 1, characterized in that: The diffusion plate includes transparent glass, transparent metal material or transparent ceramic material.

3. The backlight module according to claim 1, characterized in that: In the second area, the first surface of the diffusion plate is a planar structure parallel to the plane where the substrate is located.

4. The backlight module according to claim 1, characterized in that: The orthographic projection of the first curved surface on the plane where the substrate is located covers the orthographic projection of each of the light-emitting elements located in the first area on the plane where the substrate is located.

5. The backlight module according to claim 4, characterized in that: The second surface includes a second arc-shaped surface, and along a direction from the second surface to the first surface, the second arc-shaped surface is concave toward the first surface.

6. The backlight module according to claim 4, characterized in that: In the first region, the minimum thickness of the diffuser plate is D1, wherein D1≥0.2 mm, and D1 is smaller than the thickness of the diffuser plate in the first region.

7. The backlight module according to claim 1, characterized in that: In the second zone, the diffusion plate has a thickness D0, wherein 0.5 mm ≤ D0 ≤ 1 mm.

8. The backlight module according to claim 1, characterized in that: The diffuser plate includes a substrate; in the first area, the substrate is filled with a plurality of transparent particles, along the first direction, the transparent particles overlap with the light-emitting elements and do not overlap with the gaps between adjacent light-emitting elements, and the refractive index of the transparent particles is not equal to the refractive index of the substrate.

9. The backlight module according to claim 8, characterized in that: Along the first direction, the same light-emitting element overlaps with at least two transparent particles.

10. The backlight module according to claim 8, characterized in that: The transparent particles include at least one of bubbles, SiO, SiN, and PEDOT.

11. The backlight module according to claim 1, characterized in that: The first region includes a first sub-region and a second sub-region, the orthographic projection of the light-emitting element on the plane where the substrate is located is located in the first sub-region, and the orthographic projection of the gap between adjacent light-emitting elements on the plane where the substrate is located is located in the second sub-region; In the second sub-area, a first arc-shaped structure is disposed on the first arc-shaped surface of the diffusion plate, and the first arc-shaped structure is recessed along the surface of the first arc-shaped surface toward the second surface.

12. The backlight module according to claim 11, characterized in that: The light emitting elements are arranged in an array on the substrate, the area between two adjacent columns of the light emitting elements is a first gap, the area between two adjacent rows of the light emitting elements is a second gap, and the first arc structure is disposed in both the first gap and the second gap.

13. The backlight module according to claim 12, characterized in that: In the first gap, the first arc-shaped structure extends along an extension direction of the first gap; in the second gap, the first arc-shaped structure extends along an extension direction of the second gap.

14. The backlight module according to claim 13, characterized in that: In the first area, the hollow is provided on a side of the gap between any two adjacent light emitting elements facing the diffusion plate.

15. A display device, characterized in that: The invention comprises a display panel and the backlight module according to any one of claims 1 to 14, wherein the display panel is located in the light emitting direction of the backlight module.

16. A method for manufacturing a backlight module according to any one of claims 1 to 14, characterized in that: include: providing a substrate; A light emitting element is disposed on one side of the substrate; A diffusion plate is provided on a side of the light emitting element away from the substrate; Among them, the orthographic projection of the light-emitting element on the plane where the substrate is located is located within the outer contour of the orthographic projection of the diffuser on the plane where the substrate is located; the diffuser includes a first surface and a second surface arranged opposite to each other along a first direction, the first surface is located on the side of the second surface facing the light-emitting element, and the first direction is perpendicular to the substrate; the backlight module includes a first area and a second area arranged around the first area, and in the first area, the first surface of the diffuser includes a first curved surface, and along the direction from the first surface to the second surface, the first curved surface is recessed toward the second surface.

17. The method for manufacturing a backlight module according to claim 16, characterized in that: The manufacturing method of the diffusion plate comprises: injecting molten liquid into the mold; Dropping transparent particles into at least a portion of the melt; The diffusion plate is formed by injection molding.

18. The manufacturing method according to claim 17, characterized in that: After the transparent particles are dripped into at least a part of the melt and before the injection molding, the method further comprises: After the molten liquid is solidified, injecting the molten liquid into the mold again; Transparent particles are dropped into at least a partial region of the re-injected molten liquid.

19. The manufacturing method according to claim 17, characterized in that: After the injection molding, the method further includes forming a first arc-shaped structure on the first surface of the diffuser plate, wherein the method of forming the first arc-shaped structure includes a frosting process or a sandblasting process; The frosting process includes: using an acidic liquid to corrode at least a portion of the first surface of the diffusion plate to form the first arc-shaped structure on the first surface; The sandblasting process includes: using sand ejected from a spray gun to strike at least a portion of the first surface of the diffuser plate to form the first arc-shaped structure on the first surface.

Images