Backlight module and display device

Abstract

The application provides a backlight module and a display device. The backlight module comprises a light source substrate, an optical film layer, a dam structure and a light adjusting part. The light source substrate comprises a substrate and light emitting elements arranged on one side of the substrate. The light emitting elements are arranged in an array. The optical film layer is arranged opposite to the substrate, and the light emitting elements are located between the substrate and the optical film layer. The dam structure is arranged between the substrate and the optical film layer, and comprises a reflecting wall. The reflecting wall forms containing cavities, and the light emitting elements are arranged in the containing cavities. The light adjusting part is arranged in the containing cavities and covers the light emitting surface of the light emitting elements. At least part of the light emitted by the light emitting elements changes the propagation direction through the light adjusting part and propagates to the reflecting wall.

Description

Technical Field

[0001] This application relates to the field of display device technology, and in particular to a backlight module and display device. Background Technology

[0002] Direct-lit backlight modules have gradually gained a certain market share in the display field due to their ability to achieve precise local dimming. With the development of technology, people's requirements for the light output effect of direct-lit backlight modules have also gradually increased. Direct-lit backlight modules need to have a more uniform light output effect. However, the light uniformity effect of current direct-lit backlight modules is generally average, or the overall thickness of direct-lit backlight modules is too large in order to improve the light uniformity effect, which is not conducive to the design of thin and light. Summary of the Invention

[0003] This application provides a backlight module and display device that can enhance the light emission effect.

[0004] In a first aspect, embodiments of this application provide a backlight module, which includes a light source substrate, an optical film layer, a dam structure, and a light adjustment section. The light source substrate includes a base and light-emitting elements disposed on one side of the base, with multiple light-emitting elements arranged in an array. The optical film layer is disposed opposite to the base, and the light-emitting elements are located between the base and the optical film layer. The dam structure is disposed between the base and the optical film layer, and includes a reflective wall that encloses a receiving cavity, within which multiple light-emitting elements are disposed. The light adjustment section is disposed within the receiving cavity and covers the light-emitting surface of the light-emitting elements. At least a portion of the light emitted by the light-emitting elements has its propagation direction changed by the light adjustment section and propagates to the reflective wall.

[0005] In some alternative embodiments, the light-adjusting section includes a first arcuate surface facing the optical film layer, the orthographic projection of the first arcuate surface onto the substrate covering the orthographic projection of the light-emitting element onto the substrate. The refractive index of the light-adjusting section is greater than 1, and the first arcuate surface protrudes towards the optical film layer.

[0006] In some alternative embodiments, the light-adjusting portion includes a first surface facing the substrate and a groove structure formed by recesses in the first surface, wherein the light-emitting element is at least partially located within the groove structure.

[0007] In some alternative embodiments, the first arcuate surface is connected to the first surface.

[0008] In some alternative embodiments, the reflective wall includes a second arcuate surface that protrudes toward the receiving cavity in a direction parallel to the plane of the substrate.

[0009] In some alternative embodiments, the dam structure includes a first portion located between the plane containing the light-emitting surface of the light-emitting element and the optical film layer, with at least a portion of the second arcuate surface situated on the first portion. The width of the first portion gradually decreases in the direction away from the substrate.

[0010] In some alternative embodiments, the dam structure includes a first dam section and a second dam section located on the side of the first dam section facing away from the base. The reflective wall includes a second arcuate surface on the first dam section and a third arcuate surface on the second dam section. The third arcuate surface protrudes towards the receiving cavity in a direction parallel to the first surface.

[0011] In some alternative embodiments, the curvature of the third arcuate surface is greater than the curvature of the second arcuate surface.

[0012] In some alternative embodiments, the first dam portion extends beyond the light adjustment portion in a direction away from the substrate.

[0013] In some alternative embodiments, the dimensions of the first dam section are h1 and the dimensions of the second dam section are h2 in the thickness direction of the base, and h1 and h2 satisfy: 0.4≤h2 / h1≤0.8.

[0014] In some alternative embodiments, the width of the first dam section is w1, and the width of the second dam section is w2, where w1 and w2 satisfy: 0.35≤w2 / w1≤0.65.

[0015] In some alternative embodiments, the dam structure includes a first segment located between adjacent light-emitting elements along a first direction, a second segment located between adjacent light-emitting elements along a second direction, and an intersection segment connecting the first and second segments. The first and second directions intersect and are both parallel to the plane of the substrate. In the thickness direction of the substrate, the dimension of the intersection segment is larger than the dimensions of the first and second segments.

[0016] In some alternative embodiments, the optical film layer includes a diffusion layer, the diffusion layer including a second surface facing the substrate, the second surface having microstructures, and the cross segments being disposed in contact with the second surface.

[0017] In some alternative embodiments, in the thickness direction of the substrate, the cross segment extends beyond the first segment by a dimension H1, where H1 satisfies: 0.1mm ≤ H1 ≤ 0.5mm.

[0018] In some alternative embodiments, the size of the cross segment is H2 in the thickness direction of the substrate, and the distance between adjacent light-emitting elements is t in the first direction, wherein H2 and t satisfy: 3≤H2 / t≤4.

[0019] In some optional embodiments, the dam structure further includes a third dam section disposed on the side of the second dam section away from the base, and the reflective wall includes a fourth arcuate surface located on the third dam section. Wherein, in the thickness direction of the base, the dimension of the second dam section is h2, and the dimension of the third dam section is h3, where h2 and h3 satisfy: h3 = a * h2, 0.5 ≤ a ≤ 0.8; and / or, the width of the second dam section is w2, and the width of the third dam section is w3, where w2 and w3 satisfy: w3 = b * w2, 0.4 ≤ b ≤ 0.9.

[0020] In some alternative embodiments, the substrate includes opposing first and second edges in a first direction, the first direction being parallel to the plane containing the substrate. The second arcuate surface includes a first sub-surface and a second sub-surface protruding in the first direction, the first sub-surface being located on the side of the second sub-surface closer to the first edge. Specifically, the curvature of the first sub-surface gradually decreases in the direction from the center of the substrate to the second edge, and the curvature of the second sub-surface gradually decreases in the direction from the center of the substrate to the first edge.

[0021] In some alternative embodiments, the size of the light-adjusting part is h in the thickness direction of the substrate, and the size of the light-adjusting part is d in a first direction, which is parallel to the plane of the substrate. Wherein, d and h satisfy: 1.5mm ≤ d ≤ 2.5mm; and / or, 0.18 ≤ h / d ≤ 0.35.

[0022] In some alternative embodiments, the light emission angle of the light-emitting element is c, where c satisfies: 120°≤c≤170°.

[0023] Secondly, embodiments of this application provide a display device, which includes a backlight module as described in any of the foregoing embodiments and a display panel, wherein the display panel is disposed on the side of the optical film layer away from the substrate.

[0024] This application provides a backlight module and display device. The presence of a light adjustment unit allows more light emitted by the light-emitting element to propagate to the dam structure, where it is reflected by the reflective wall, changing the propagation direction. This, through the cooperation of the light adjustment unit and the dam structure, improves the uniformity of light within the designated area, enhancing the light output performance of the backlight module. Furthermore, since the light adjustment unit is located within the receiving cavity, rather than on the side of the dam structure away from the substrate, its presence does not affect the overall thickness of the backlight module. In this embodiment, the backlight module does not require an additional air layer between the optical film layer and the dam structure to improve uniformity; the dam structure can directly contact the optical film layer. Therefore, this design improves the light output performance while reducing the overall thickness of the backlight module and lowering the risk of structural collapse of the optical film layer due to the presence of an additional air layer. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of a backlight module provided in an embodiment of this application; Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure at point AA; Figure 3 This is a cross-sectional structural diagram of a backlight module at point AA provided in an embodiment of this application; Figure 4 yes Figure 1 A magnified structural diagram of region Q in the middle region; Figure 5 yes Figure 4 Schematic diagram of the cross-sectional structure at point BB; Figure 6 This is a cross-sectional structural diagram of a backlight module at point AA provided in an embodiment of this application; Figure 7 This is a cross-sectional structural diagram of a backlight module at point AA provided in an embodiment of this application; Figure 8 This is a cross-sectional structural diagram of a backlight module at point AA provided in an embodiment of this application; Figure 9 This is a schematic diagram of the structure of a display device provided in an embodiment of this application.

[0027] Marker explanation: 100. Backlight module; 200. Display panel; 300. Display device; 10. Light source substrate; 11. Substrate; 12. Light-emitting element; 121. Light-emitting surface; 20. Optical film layer; 21. Diffusion layer; 211. Second surface; 22. Brightness enhancement layer; 30. Dike structure; 31. Reflective wall; 311. Second arc-shaped surface; 311a. First sub-surface; 311b. Second sub-surface; 312. Third arc-shaped surface; 313. Fourth arc-shaped surface; 32. First dike section; 321. First part; 322. Second part; 33. Second dike section; 34. Third dike section; 35. First segment; 36. Second segment; 37. Intersection; 40. Light adjustment section; 41. First arc-shaped surface; 42. First surface; 43. Groove structure; 50. Liquid crystal layer; R, receiving cavity; E1, first edge; E2, second edge; X, first direction; Y, second direction; Z, thickness direction. Detailed Implementation

[0028] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0030] Firstly, please refer to Figure 1 and Figure 2 This application provides a backlight module 100, which includes a light source substrate 10, an optical film layer 20, a dam structure 30, and a light adjustment section 40. The light source substrate 10 includes a base 11 and light-emitting elements 12 disposed on one side of the base 11, with multiple light-emitting elements 12 arranged in an array. The optical film layer 20 is disposed opposite to the base 11, and the light-emitting elements 12 are located between the base 11 and the optical film layer 20. The dam structure 30 is disposed between the base 11 and the optical film layer 20, and includes a reflective wall 31 that encloses a receiving cavity R, in which multiple light-emitting elements 12 are disposed. The light adjustment section 40 is disposed within the receiving cavity R and covers the light-emitting surface 121 of the light-emitting elements 12. At least a portion of the light emitted by the light-emitting elements 12 changes its propagation direction through the light adjustment section 40 and propagates onto the reflective wall 31.

[0031] The backlight module 100 is used in conjunction with the display panel to form a liquid crystal display device, and the backlight module 100 provides a light source for the display panel. Optionally, the display panel includes a liquid crystal layer, an array substrate, and a color filter substrate. The array substrate includes pixel electrodes and a common electrode. The pixel electrodes and the common electrode work together to control the deflection of liquid crystal molecules within the liquid crystal layer, thereby changing the light transmittance to present different brightness levels. The color filter in the color filter substrate can filter the light passing through the liquid crystal layer, thereby achieving a multi-color display effect.

[0032] The light source substrate 10 is a core component of the backlight module 100. The light source substrate 10 includes a substrate 11 and a light-emitting element 12. The substrate 11 supports and carries the light-emitting element 12. The light-emitting element 12 can take various forms; for example, it can be an LED (Light-Emitting-Diode), MicroLED, or similar device. LED (Micro-Light Emitting Diode), Min LED (Mini-Light-Emitting-Diode), the type of light-emitting element 12 is not limited in this application embodiment.

[0033] The dam structure 30 surrounds and defines a receiving cavity R around the light-emitting element 12. A single receiving cavity R can accommodate only one light-emitting element 12, or multiple light-emitting elements 12 can be placed in a single receiving cavity R. The presence of the dam structure 30 can divide the backlight module 100 into multiple light-control zones, that is, adjacent light-control zones are separated by the dam structure 30. The setting of the dam structure 30 can adjust the size and dimensions of the light-control zones to correspond to the liquid crystal zones in the display panel 200, thereby reducing halo phenomenon and improving local dimming performance.

[0034] The reflective wall 31 is the surface of the dam structure 30 facing the receiving cavity R. Light propagating to the reflective wall 31 can be reflected, thereby allowing the light to be better superimposed and blended. Optionally, the reflectivity of the reflective layer is greater than 90%. More optionally, the surface of the dam structure 30 facing the receiving cavity R includes a high-reflectivity coating. The morphology of the reflective wall 31 is not limited in this embodiment; the reflective wall 31 can be a planar structure, or it can be an arc surface or other regular or irregular shapes.

[0035] It should be noted that there can be multiple dam structures 30, which are set independently of each other, that is, the dam structures 30 between different adjacent light-emitting elements 12 are spaced apart from each other. Alternatively, there can be only one dam structure 30, which is a mesh structure, with multiple light-emitting elements 12 arranged in multiple grid openings formed by the mesh structure.

[0036] The optical film layer 20 is a film structure that performs certain optical functions. The optical film layer 20 is located on one side of the light-emitting surface 121 of the light-emitting element 12, and the orthographic projection of the optical film layer 20 on the substrate 11 covers the orthographic projection of multiple light-emitting elements 12 on the substrate 11. The light emitted by the light-emitting elements 12 often needs to be adjusted by the optical film layer 20 before leaving the backlight module 100.

[0037] Normally, only a small amount of light from the light-emitting element 12 can propagate obliquely to the dam structure 30. The forward light emitted by the light-emitting element 12 usually enters the optical film layer 20 directly and exits the backlight module 100. In this case, the dam structure 30 has a limited effect on improving the light uniformity of the backlight module 100. Therefore, in this embodiment, a light adjustment section 40 is added to the backlight module 100. The light adjustment section 40 is disposed together with the light-emitting element 12 within the receiving cavity R, meaning that the distance between the light adjustment section 40 and the light-emitting element 12 in the thickness direction Z of the substrate 11 is relatively close. Furthermore, the light adjustment section 40 covers the light-emitting surface 121 of the light-emitting element 12, so that all or most of the light emitted from the light-emitting surface 121 of the light-emitting element 12 enters the light adjustment section 40. A single light adjustment section 40 may cover the light-emitting surface 121 of a single light-emitting element 12, or a single light adjustment section 40 may simultaneously cover the light-emitting surfaces 121 of multiple light-emitting elements 12.

[0038] Based on this, at least part of the light emitted by the light-emitting element 12 no longer propagates directly to the optical film layer 20, but changes direction through the adjustment of the light adjustment unit 40 and propagates to the reflective wall 31. Under this design, the amount of light emitted by the light-emitting element 12 and propagating to the reflective wall 31 can be increased, so that the dam structure 30 can reflect more light, thereby mixing more light emitted by the light-emitting element 12, improving the uniformity of light in the partition, and enhancing the light output effect of the backlight module 100.

[0039] Experimental results show that, under the action of the light adjustment unit 40 and the dam structure 30, the light emitted by the light-emitting element 12 can be better mixed within the partition, and the average brightness within a single partition is improved by about 32% compared with the reflector cup architecture design in related technologies.

[0040] In summary, in this embodiment, the presence of the light adjustment unit 40 enables more light emitted by the light-emitting element 12 to propagate to the dam structure 30, and to be reflected and have its propagation direction changed by the action of the reflective wall 31. In this way, by means of the cooperation between the light adjustment unit 40 and the dam structure 30, the uniformity of light in the partition is improved and the light output effect of the backlight module 100 is enhanced.

[0041] Furthermore, since the light adjustment unit 40 is disposed within the receiving cavity R, rather than on the side of the dam structure 30 facing away from the substrate 11, the presence of the light adjustment unit 40 does not affect the overall thickness of the backlight module 100. In this embodiment, the backlight module 100 does not require an additional air layer between the optical film layer 20 and the dam structure 30 to improve light uniformity; that is, the dam structure 30 can be directly contacted with the optical film layer 20. Therefore, this design can improve the light emission effect while reducing the overall thickness of the backlight module 100 and lowering the risk of structural collapse of the optical film layer 20 due to the presence of an air layer.

[0042] In some alternative embodiments, the material of the dam structure 30 includes at least one of silicone and acrylate. The material in the reflector cup is typically polycarbonate, which is prone to deformation and yellowing. The silicone and acrylate used in this embodiment can mitigate the risks of deformation and light emission problems, thus improving the lifespan of the backlight module 100. Further optionally, the dam structure 30 can be formed by dispensing, molding, or injection molding.

[0043] In some embodiments, such as Figure 2 As shown, the light adjustment unit 40 includes a first arcuate surface 41 facing the optical film layer 20, and the orthographic projection of the first arcuate surface 41 onto the substrate 11 covers the orthographic projection of the optical element onto the substrate 11. The refractive index of the light adjustment unit 40 is greater than 1, and the first arcuate surface 41 protrudes towards the optical film layer 20.

[0044] The first arcuate surface 41 indicates that the light adjustment part 40 has a continuously curved (non-planar) geometry on the side surface facing the optical film layer 20 in at least one direction, and the first arcuate surface 41 is provided to protrude away from the substrate 11. The curvature of the first arcuate surface 41 at different positions may be consistent or may be different, and this embodiment does not limit this.

[0045] In engineering optics, the refractive index of air is often approximated as 1. The refractive index of the light adjustment unit 40 is greater than 1, meaning that the refractive index of the light adjustment unit 40 is greater than the refractive index of the surrounding environment. Based on this, light rays leaving the light adjustment unit 40 and entering the surrounding environment will be refracted or totally internally reflected at the first arc-shaped surface 41, thereby changing the direction of light propagation.

[0046] It should be noted that although the first arc-shaped surface 41 makes at least a portion of the structure in the light adjustment section 40 resemble a convex lens, and a convex lens itself has a light-focusing effect, the light-focusing effect of a convex lens is only applicable when the incident light is parallel. However, the light emitted by the light-emitting element 12 is not parallel, and in this embodiment, the refractive index of the light adjustment section 40 is greater than the refractive index of the surrounding environment. Based on this, combined with Figure 2 As can be seen from the light path shown, the light emitted by the light-emitting element 12 will increase the emission angle at the first arc-shaped surface 41 due to refraction or total internal reflection, thereby allowing more light to propagate to the reflective wall 31 of the dam structure 30.

[0047] In this embodiment, by adjusting the material and morphology of the light adjustment part 40, the light emitted from the light-emitting element 12 is refracted or totally reflected at the first arc-shaped surface 41, thereby increasing the light emission angle and allowing more light to propagate to the convex reflective wall 31 of the dam structure 30 and undergo reflection. This can improve the uniformity of light within the partition and enhance the light emission effect of the backlight module 100.

[0048] In some embodiments, such as Figure 2 As shown, the light adjustment section 40 includes a first surface 42 facing the substrate 11 and a groove structure 43 formed by the recess of the first surface 42, wherein the light-emitting element 12 is at least partially located within the groove structure 43.

[0049] The first surface 42 is the surface of the light-adjusting portion 40 facing the substrate 11. The first surface 42 may be in contact with the substrate 11, or it may be spaced apart from the substrate 11. The groove structure 43 is formed by recessing the first surface 42 inward and is used to accommodate at least a portion of the structure of the light-emitting element 12. Optionally, the light-emitting element 12 is completely located within the groove structure 43, that is, the light-adjusting portion 40 completely covers the light-emitting element 12.

[0050] In some alternative embodiments, the light adjustment part 40 includes a transparent encapsulation material. During the fabrication of the backlight module 100, a light-emitting element 12 is first formed on the substrate 11, and then the light adjustment part 40 covering the light-emitting element 12 is formed by a dispensing process.

[0051] In this embodiment, at least a portion of the structure of the light-emitting element 12 is embedded within the groove structure 43 of the light-adjusting section 40. This reduces the distance between the light-emitting element 12 and the light-adjusting section 40, and increases the coverage area of ​​the light-emitting element 12 by the light-adjusting section 40. This allows more light emitted from the light-emitting element 12 to enter the light-adjusting section 40 and undergo refraction or total internal reflection, increasing the light emission angle and thus increasing the amount of light reaching the reflective wall 31, thereby enhancing the uniform light distribution of the backlight module 100. Furthermore, this design also provides encapsulation and protection for the light-emitting element 12, improving its lifespan and enhancing the reliability of the backlight module 100. Additionally, this design reduces the overall height of the light-emitting element 12 and the light-adjusting section 40, minimizing the impact of the light-adjusting section 40 on the thickness of the backlight module 100.

[0052] In some embodiments, the first arcuate surface 41 is connected to the first surface 42. In other words, there is no other connecting surface between the first arcuate surface 41 and the first surface 42, and the first arcuate surface 41 is directly connected to the peripheral edge of the first surface 42.

[0053] In this embodiment of the application, the first arc-shaped surface 41 is connected to the first surface 42, thereby increasing the size of the first arc-shaped surface 41. Under this design, more light emitted by the light-emitting element 12 will be refracted or totally reflected at the first arc-shaped surface 41 and change its propagation direction, thereby further increasing the amount of light propagating to the dam structure 30, so that more light can be reflected and mixed at the reflective wall 31, enhancing the light output effect of the backlight module 100.

[0054] In some embodiments, such as Figure 2 As shown, the reflective wall 31 includes a second arcuate surface 311, which protrudes toward the receiving cavity R in a direction parallel to the plane of the base 11.

[0055] The second arc-shaped surface 311 is part or all of the area in the reflective wall 31, that is, light propagating to the second arc-shaped surface 311 can be reflected. The curvature of the second arc-shaped surface 311 at different positions can be consistent or different. This application embodiment does not limit this.

[0056] In this embodiment, the reflective wall 31 is not a planar structure, but includes a second arc-shaped surface 311. This allows light rays propagating to different positions on the second arc-shaped surface 311 to be affected by different reflections, making the propagation directions of the different light rays after reflection more chaotic, thereby further improving the mixing degree between different light rays and enhancing the light output effect of the backlight module 100.

[0057] Furthermore, as can be seen from the accompanying drawings, the second arc-shaped surface 311 protrudes horizontally towards the corresponding receiving cavity R. This ensures that the light reflected from the second arc-shaped surface 311 will not propagate to other locations on the second arc-shaped surface 311. In other words, the light will only be reflected once on the second arc-shaped surface 311 of the first dam portion 32, thereby reducing the number of light reflections, reducing brightness loss, and improving the overall light output brightness of the backlight module 100.

[0058] In some embodiments, such as Figure 2 As shown, the dam structure 30 includes a first portion 321 located between the plane containing the light-emitting surface 121 of the light-emitting element 12 and the optical module, and a portion of the second arc-shaped surface 311 is located on the first portion 321. The width of the first portion 321 gradually decreases in the direction away from the substrate 11. As can be seen from the accompanying drawings, the width of the first portion 321 is its dimension in the first direction X.

[0059] In addition to the first part 321, the dam structure 30 may also include a second part 322, which is located between the first part 321 and the base 11. The second arcuate surface 311 may be completely located on the first part 321, or the second arcuate surface 311 may be partially located on the first part 321 and partially located on the second part 322. This application embodiment does not limit this.

[0060] Since the first part 321 is located between the plane of the light-emitting surface 121 of the light-emitting element 12 and the optical module, and the second part 322 is located between the plane of the light-emitting surface 121 of the light-emitting element 12 and the substrate 11, the light emitted by the light-emitting element 12 can propagate to the first part 321 but not to the second part 322. Based on this, in this embodiment, the first part 321 is configured to gradually increase in width in the direction away from the substrate 11. Thus, combined with the light path, it can be seen that the light reflected by the first part 321 will propagate in the direction away from the substrate 11, but will not propagate in the direction close to the substrate 11, thereby helping to improve the overall light output brightness of the backlight module 100.

[0061] It should be noted that since the second portion 322 has a relatively small impact on the light emitted by the light-emitting element 12, the morphology of the second portion 322 is not limited in this embodiment. For example, in the direction away from the substrate 11, the width of the second portion 322 can remain constant, or the width of the second portion 322 can gradually decrease, or the width of the second portion 322 can gradually increase.

[0062] In some embodiments, please refer to Figure 3 The dam structure 30 includes a first dam section 32 and a second dam section 33 located on the side of the first dam section 32 facing away from the base 11. The reflective wall 31 includes a second arcuate surface 311 located on the first dam section 32 and a third arcuate surface 312 located on the second dam section 33. The third arcuate surface 312 protrudes towards the receiving cavity R in a direction parallel to the first surface 42.

[0063] In conjunction with the aforementioned embodiments, the first dam section 32 includes a first part 321 and a second part 322. The second dam section 33 is located on the side of the first dam section 32 away from the base 11. In the thickness direction Z of the base 11, the height of the first dam section 32 can be greater than the height of the second dam section 33, or the height of the first dam section 32 can be less than or equal to the height of the second dam section 33.

[0064] Light rays propagating to the first cofferdam section 32 can be reflected at the second arcuate surface 311, and light rays propagating to the second cofferdam section 33 can be reflected at the third arcuate surface 312. Furthermore, the second arcuate surface 311 and the third arcuate surface 312 can be arranged adjacent to each other, and the tangent plane on the second arcuate surface 311 connecting to one end of the third arcuate surface 312 intersects with the tangent plane on the third arcuate surface 312 connecting to one end of the second arcuate surface 311.

[0065] It should be noted that the curvature of the second arcuate surface 311 and the curvature of the third arcuate surface 312 may be the same or different. Curvature is a macroscopic quantity describing the overall degree of curvature of a curved surface. The greater the curvature, the higher the overall degree of curvature of the surface. In other words, the second arcuate surface 311 and the third arcuate surface 312 may have the same degree of curvature, or they may have different degrees of curvature.

[0066] As shown in the attached figures, in the thickness direction Z of the substrate 11, the height of the first dam portion 32 is h1, and the height of the second dam portion 33 is h2. In the first direction X, the width of the first dam portion 32 is w1, and the width of the second dam portion 33 is w2. Here, the widths w1 and w2 refer to the maximum width dimensions of the first dam portion 32 and the second dam portion 33. The height h1 of the first dam portion 32 is positively correlated with its width w1. Furthermore, the first dam portion 32 and the light-emitting element 12 need to be spaced a certain distance apart in the first direction X to meet the size requirements of the light control zone. Based on this, the width w1 of the first dam portion 32 should not be too large, thus indirectly limiting the height h1 of the first dam portion 32.

[0067] In view of this, in this embodiment of the application, a second dam section 33 is added on the basis of the first dam section 32. The second dam section 33 is located on the side of the first dam section 32 away from the base 11. The setting of the second dam section 33 can increase the overall height of the dam structure 30 without increasing the width w1 of the first dam section 32, so that more light emitted by the light-emitting element 12 can be transmitted to the dam structure 30 and reflected, thereby improving the uniformity of light in the partition and enhancing the light output effect of the backlight module 100.

[0068] It should be noted that, for the second dam section 33, in the direction away from the base 11, the width of the second dam section 33 can first increase and then decrease, or the width of the second dam section 33 can continue to decrease. This application embodiment does not limit this, as long as the width w2 of the second dam section 33 is not greater than the width w1 of the first dam section 32, so that the overall maximum width of the dam structure 30 is the width w1.

[0069] Furthermore, the height h1 of the first dam section 32 can be greater than the height h2 of the second dam section 33, or the height h1 of the first dam section 32 can be less than or equal to the height h2 of the second dam section 33. Optionally, the height h2 of the second dam section 33 is less than the height h1 of the first dam section 32. By limiting the height h2 of the second dam section 33, the adverse effect of the presence of the dam structure 30 on the overall thickness of the backlight module 100 is reduced, which is beneficial for a thinner and lighter design.

[0070] In some embodiments, such as Figure 3 As shown, the curvature of the third arcuate surface 312 is greater than the curvature of the second arcuate surface 311. In other words, the overall curvature of the third arcuate surface 312 is greater than the overall curvature of the second arcuate surface 311.

[0071] As can be seen from the light path diagram, light rays with a smaller tilt will propagate to the second dam section 33, while light rays with a larger tilt will propagate to the first dam section 32. Based on this, by setting the curvature of the third arc-shaped surface 312 to be greater than that of the second arc-shaped surface 311, light rays with a larger tilt propagating to the first dam section 32 will experience a significant change in propagation direction on the second arc-shaped surface 311. Conversely, light rays with a smaller tilt propagating to the second dam section 33 will experience a smaller change in propagation direction on the third arc-shaped surface 312. Thus, the first dam section 32 can achieve a better light mixing effect, while the second dam section 33, in addition to its light-uniforming effect, can also help adjust some tilted light rays to positive light, thereby achieving a light-focusing effect and improving the light output brightness of the backlight module 100.

[0072] In some embodiments, the first dam portion 32 extends beyond the light adjustment portion 40 in a direction away from the substrate 11. Exemplarily, both the first dam portion 32 and the light adjustment portion 40 are disposed in contact with the substrate 11, and the height h1 of the first dam portion 32 is greater than the height of the light adjustment portion 40.

[0073] As can be seen from the foregoing, the first dam section 32 is the main part of the dam structure 30 that plays a role in uniform light distribution. In view of this, the height h1 of the first dam section 32 in this embodiment is adjusted so that the first dam section 32 extends beyond the light adjustment section 40 in the direction away from the base 11. In this case, more light emitted by the light-emitting element 12 and whose direction is adjusted by the light adjustment section 40 can propagate to the first dam section 32 and be reflected by the second arc-shaped surface 311, thereby further improving the uniform light distribution effect and enhancing the light emission effect of the backlight module 100.

[0074] In some embodiments, h1 and h2 satisfy: 0.4 ≤ h2 / h1 ≤ 0.8. For example, the value of h2 / h1 is one of 0.4, 0.5, 0.6, 0.7, and 0.8.

[0075] In this embodiment, by setting the first dam section 32 to have a relatively large height h1, such that h2 / h1 is not greater than 0.8, more light can propagate to the first dam section 32 and be reflected by the second arc-shaped surface 311, thereby improving the light uniformity and enhancing the light emission effect of the backlight module 100. Furthermore, h2 / h1 is adjusted to be not less than 0.4, so that the height h2 of the second dam section 33 has a certain dimension. This increases the overall height of the dam structure 30 without affecting its maximum width, allowing most of the light emitted by the light-emitting element 12 to be reflected and adjusted by the dam structure 30.

[0076] In some embodiments, w1 and w2 satisfy: 0.35 ≤ w2 / w1 ≤ 0.65. Optionally, the value of w2 / w1 is one of 0.35, 0.4, 0.5, 0.6, and 0.65.

[0077] In this embodiment, by setting the first dam portion 32 to have a larger width w1, such that w2 / w1 is no greater than 0.65, the second arc-shaped surface 311 can have a larger area, allowing it to receive and reflect more light, thereby improving the uniform light distribution effect. Simultaneously, a larger width w1 also enhances the support effect of the first dam portion 32 on the second dam portion 33, strengthening the structural stability of the dam structure 30. Furthermore, setting w2 / w1 to no less than 0.35 indirectly controls the curvature of the corresponding arc-shaped surface 311 and the third arc-shaped surface 312 by limiting the height and width dimensions of the first and second dam portions 32 and 33, thereby improving the reliability of light path propagation.

[0078] In some embodiments, please refer to Figures 4 to 6 The dam structure 30 includes a first segment 35 located between adjacent light-emitting elements 12 along a first direction X, a second segment 36 located between adjacent light-emitting elements 12 along a second direction Y, and an intersection segment 37 connecting the first segment 35 and the second segment 36. The first direction X and the second direction Y intersect and are both parallel to the plane of the base 11. In the thickness direction Z of the base 11, the dimension of the intersection segment 37 is larger than the dimensions of the first segment 35 and the second segment 36.

[0079] The dam structure 30 has a mesh-like structure and defines multiple receiving cavities R, which are arranged in the first direction X and the second direction Y. A first segment 35 is a portion of the dam structure 30 located on one side of a receiving cavity R along the first direction X, and extends along the second direction Y. A second segment 36 is a portion of the dam structure 30 located on one side of a receiving cavity R along the second direction Y, and extends along the first direction X. Optionally, the first direction X, the second direction Y, and the thickness direction Z of the base 11 are perpendicular to each other.

[0080] The cross section 37 connects the first segment 35 and the second segment 36, that is, the cross section 37 is located at the corner of the receiving cavity R. The first segment 35 and the second segment 36 can both be integrally connected to the cross section 37, that is, the first segment 35, the second segment 36 and the cross section 37 are jointly formed.

[0081] The dimension of the intersection segment 37 in the thickness direction Z of the base 11 is the height dimension of the intersection segment 37. The dimension of the first segment 35 in the thickness direction Z of the base 11 is the height dimension of the first segment 35. The dimension of the second segment 36 in the thickness direction Z of the base 11 is the height dimension of the second segment 36. Optionally, the first segment 35 and the second segment 36 have the same height dimension.

[0082] The height of the intersection segment 37 is greater than the height of the first segment 35 and the second segment 36. Optionally, the first segment 35 and the second segment 36 each include a first cofferdam 32 and a second cofferdam 33, while the intersection segment 37 includes a first cofferdam 32, a second cofferdam 33 and a fourth cofferdam. The first cofferdam 32 in the intersection segment 37 is connected to the first cofferdam 32 of the first segment 35 and the first cofferdam 32 of the second segment 36. The second cofferdam 33 in the intersection segment 37 is connected to the second cofferdam 33 of the first segment 35. The fourth cofferdam in the intersection segment 37 is connected to the second cofferdam 33 of the second segment 36.

[0083] In this embodiment, the cross segment 37 has a larger height relative to the first segment 35 and the second segment 36. This allows the cross segment 37 to protrude relative to the first segment 35 and the second segment 36 on the side away from the substrate 11. Consequently, the optical film layer 20 can contact only the cross segment 37, without contacting the first segment 35 or the second segment 36. This design reduces the contact area between the dam structure 30 and the optical film layer 20, minimizing the influence between them and improving the reliability of the optical film layer 20. Furthermore, the spacing between the first segment 35 and the second segment 36 relative to the optical film layer 20 can act as an air layer to some extent, thereby further improving light uniformity and enhancing the light emission effect of the backlight module 100 without affecting the overall thickness of the backlight module 100.

[0084] In some embodiments, such as Figure 5 As shown, the optical film layer 20 includes a diffusion layer 21, which includes a second surface 211 facing the substrate 11. The second surface 211 is provided with microstructures (not shown in the figure), and the cross segment 37 is disposed in contact with the second surface 211.

[0085] The diffusion layer 21 diffuses light, thereby improving the light uniformity. Optionally, the optical film layer 20 also includes a brightness enhancement layer 22 disposed on the side of the diffusion layer 21 facing away from the substrate 11, as well as other functional film layers. Among them, the brightness enhancement layer 22 can improve the emitted light brightness.

[0086] The second surface 211 is the surface of the diffusion layer 21 facing the substrate 11. The second surface 211 has microstructures, and the presence of the microstructures makes the second surface 211 no longer flat but uneven. The microstructures can be formed by surface treatment such as roughening the second surface 211, or by forming a coating on one side of the diffusion layer 21. This application embodiment does not limit this.

[0087] In this embodiment, the intersection segment 37 is positioned in contact with the second surface 211, enabling the dam structure 30 to provide support for the diffusion layer 21 and reducing the risk of collapse and deformation of the diffusion layer 21. Furthermore, by providing microstructures on the second surface 211, the contact area between the intersection segment 37 and the diffusion layer 21 is reduced at the microscopic level, thereby reducing the adverse effects of friction between the two on the diffusion layer 21.

[0088] In some embodiments, such as Figure 4 and Figure 5 As shown, in the thickness direction Z of the base 11, the dimension of the intersection segment 37 extending beyond the first segment 35 is H1, where H1 satisfies: 0.1mm ≤ H1 ≤ 0.5mm. For example, the value of H1 is one of 0.1mm, 0.2mm, 0.3mm, 0.4mm, and 0.5mm.

[0089] As can be seen from the foregoing, the protruding design of the intersection segment 37 relative to the first segment 35 allows for contact between the dam structure 30 and the optical film layer 20, while also enabling the first segment 35 and the second segment 36 to be spaced apart from the optical film layer 20, thus acting as an air layer to some extent. Based on this, this embodiment sets the dimension H1 to be no less than 0.1 mm to improve the uniformity of light within the partition and enhance the light emission effect of the backlight module 100. Furthermore, the dimension H1 is set to be no greater than 0.5 mm to reduce its impact on the thickness of the backlight module 100, contributing to a thinner and lighter design.

[0090] In some alternative embodiments, the dimension of the intersection segment 37 extending beyond the second segment 36 in the thickness direction Z of the substrate 11 is also between 0.1mm and 0.5mm, which will not be described again in the embodiments of this application.

[0091] In some embodiments, such as Figure 4 and Figure 5 As shown, in the thickness direction Z of the substrate 11, the size of the intersection segment 37 is H2, and in the first direction X, the distance between adjacent light-emitting elements 12 is t. H2 and t satisfy: 3 ≤ H2 / t ≤ 4. For example, the value of H2 / t is one of 3, 3.2, 3.5, 3.8, and 4.

[0092] The dimension H2 of the intersection segment 37 is its height, which is positively correlated with the thickness of the air layer. The distance t between adjacent light-emitting elements 12 is generally negatively correlated with the distribution density of the light-emitting elements 12. Based on this, the embodiments of this application limit the ratio of H2 to t to between 3 and 4, thereby making the height of the intersection segment 37 positively correlated with the distance between adjacent light-emitting elements 12, and thus making a specific relationship between the thickness of the air layer and the distribution density of the light-emitting elements 12. This satisfies the required uniform light effect under different distribution densities of the light-emitting elements 12, and has strong applicability and flexibility.

[0093] In some embodiments, please refer to Figure 7 The dam structure 30 also includes a third dam section 34 disposed on the side of the second dam section 33 facing away from the base 11, and the reflective wall 31 includes a fourth arcuate surface 313 located on the third dam section 34. In the thickness direction Z of the base 11, the dimension of the second dam section 33 is h2, and the dimension of the third dam section 34 is h3, where h2 and h3 satisfy: h3 = a * h2, 0.5 ≤ a ≤ 0.8. For example, the value of a is one of 0.5, 0.6, 0.7, and 0.8.

[0094] In other embodiments, the width of the second dam portion 33 is w2, and the width of the third dam portion 34 is w3, where w2 and w3 satisfy: w3 = b * w2, 0.4 ≤ b ≤ 0.9. For example, the value of b is one of 0.4, 0.5, 0.7, and 0.9.

[0095] In addition to the first cofferdam section 32 and the second cofferdam section 33, the dam structure 30 may also include a third cofferdam section 34. Similar to the first and second cofferdam sections 32 and 33, the third cofferdam section 34 includes a fourth arcuate surface 313, which protrudes towards the receiving cavity R. Optionally, the dam structure 30 may include more cofferdam sections than the three cofferdam sections mentioned above, or it may not include any other cofferdam sections. This application embodiment does not impose any limitations on this.

[0096] In the case where the dam structure 30 includes a third dam section 34, the height and width relationship between the second dam section 33 and the third dam section 34 is restricted in this embodiment. The height h3 of the third dam section 34 is set to be less than the height h2 of the second dam section 33, and the ratio between the two is restricted to between 0.5 and 0.8. The width w3 of the third dam section 34 is set to be less than the width w2 of the second dam section 33, and the ratio between the two is restricted to between 0.4 and 0.9. This balances the overall structural reliability of the dam structure 30 and the light reflection adjustment effect of the dam structure 30, improves the uniformity of light within the partition, and enhances the light output effect of the backlight module 100.

[0097] In some optional embodiments, when the cofferdam structure 30 further includes a fifth cofferdam section disposed on the side of the third cofferdam section 34 away from the base 11, the height ratio between the fifth cofferdam section and the third cofferdam section 34 can also be between 0.5 and 0.8, and the width ratio between the fifth cofferdam section and the third cofferdam section 34 can also be between 0.4 and 0.9. The same principle applies when the cofferdam structure 30 includes more cofferdam sections, which will not be elaborated further in this application.

[0098] In some embodiments, please refer to Figure 1 and Figure 8 The base 11 includes a first edge E1 and a second edge E2 opposite to each other in a first direction X, the first direction X being parallel to the plane containing the base 11. The second arcuate surface 311 includes a first sub-surface 311a and a second sub-surface 311b protruding in the first direction X, the first sub-surface 311a being located on the side of the second sub-surface 311b closest to the first edge E1. Specifically, the curvature of the first sub-surface 311a gradually decreases in the direction from the center of the base 11 to the second edge E2, and the curvature of the second sub-surface 311b gradually decreases in the direction from the center of the base 11 to the first edge E1.

[0099] The second arc-shaped surface 311 includes a first sub-surface 311a and a second sub-surface 311b, which are used to enclose and form adjacent different receiving cavities R. When the dam structure 30 only includes the first dam section 32, the first sub-surface 311a can be directly connected to the second sub-surface 311b. However, when the dam structure 30 also includes the second dam section 33, the first sub-surface 311a and the second sub-surface 311b are spaced apart and both are connected to the third arc-shaped surface 312.

[0100] The first edge E1 and the second edge E2 are two edges of the base 11 in the first direction X. Both the first edge E1 and the second edge E2 extend along the second direction Y. Compared with the second sub-surface 311b, the first sub-surface 311a is set closer to the first edge E1, and compared with the first sub-surface 311a, the second sub-surface 311b is set closer to the second edge E2. Based on this, some light rays that are obliquely emitted towards the second edge E2 will propagate to the first sub-surface 311a and, under the effect of reflection, change their direction path and continue to propagate towards the first edge E1. On the other hand, some light rays that are obliquely emitted towards the first edge E1 will propagate to the second sub-surface 311b and, under the effect of reflection, change their direction path and continue to propagate towards the second edge E2.

[0101] For the first sub-surface 311a, the smaller the curvature of the first sub-surface 311a, the easier it is for light propagating onto the first sub-surface 311a to be tilted and reflected closer to the first edge E1. Therefore, this embodiment of the application designs the curvature of the first sub-surface 311a at different locations differently, so that the curvature of the first sub-surface 311a gradually decreases in the direction from the center of the substrate 11 to the second edge E2; that is, the closer to the second edge E2, the smaller the curvature of the first sub-surface 311a. Based on this, the closer to the second edge E2, the more light emitted by the light-emitting element 12 and reflected by the first sub-surface 311a is emitted towards the center of the substrate 11. This helps to even out the light emitted from more edges to the central area of ​​the backlight module 100, improving light leakage. Thus, during the use of the display device 300, the display brightness at tilted viewing angles is reduced, the display brightness at normal viewing angles is increased, and the display experience is improved.

[0102] Similarly, for the second sub-surface 311b, the smaller the curvature of the second sub-surface 311b, the easier it is for light propagating onto the second sub-surface 311b to be tilted and reflected closer to the second edge E2. Therefore, this embodiment of the application designs the curvature of the second sub-surface 311b at different locations differently, so that the curvature of the second sub-surface 311b gradually decreases in the direction from the center of the substrate 11 to the first edge E1; that is, the closer to the first edge E1, the smaller the curvature of the second sub-surface 311b. Based on this, the closer to the first edge E1, the more light emitted by the light-emitting element 12 and reflected by the second sub-surface 311b is emitted towards the center of the substrate 11. This helps to even out the light emitted from more edges to the central area of ​​the backlight module 100, improving light leakage. Thus, during the use of the display device 300, the display brightness at tilted viewing angles is reduced, the display brightness at normal viewing angles is increased, and the display experience is improved.

[0103] In some embodiments, such as Figure 6 As shown, the size of the light adjustment part 40 is h in the thickness direction Z of the substrate 11, and the size of the light adjustment part 40 is d in the first direction X, which is parallel to the plane of the substrate 11. Wherein, d and h satisfy: 1.5mm ≤ d ≤ 2.5mm; and / or, 0.18 ≤ h / d ≤ 0.35. For example, the value of d is one of 1.5mm, 2mm, 2.2mm, and 2.5mm, and the value of h / d is one of 0.18, 0.2, 0.25, 0.3, and 0.35.

[0104] This application embodiment limits the dimensions of the light adjustment section 40. Dimension h is the height of the light adjustment section 40, and dimension d is the width of the light adjustment section 40. The width d of the light adjustment section 40 can be limited to not less than 1.5 mm and not more than 2.5 mm, or h / d can be limited to not less than 0.18 and not more than 0.35. This allows the light adjustment section 40 to cover the light-emitting surface 121 of the light-emitting element 12, and also ensures that the light adjustment section 40 is completely located within the receiving cavity R, thereby reducing the risk of interference between the light adjustment section 40 and the dam structure 30. Further optionally, 0.25 ≤ h / d ≤ 0.3. For example, the value of h / d is one of 0.25, 0.26, 0.27, 0.8, and 0.3.

[0105] In some embodiments, the light emission angle of the light-emitting element 12 is c, where c satisfies: 120°≤c≤170°. For example, c is one of 120°, 140°, 150°, 160° and 170°.

[0106] The emission angle c of the light-emitting element 12 refers to the angle between the light rays at 50% of their maximum intensity. In related technologies, the light-emitting element 12 is usually selected with a smaller emission angle, so that more light rays from the light-emitting element 12 can be emitted in the forward direction. However, in this embodiment, due to the cooperation between the light adjustment unit 40 and the dam structure 30, the larger inclined light rays emitted by the light-emitting element 12 can change their propagation path through refraction and reflection, thereby improving the uniform light effect within the zone. Based on this, the light-emitting element 12 can be selected with a larger emission angle. Thus, the emission angle c of the light-emitting element 12 in this embodiment can be in the range of 120°-170°, enhancing the applicability and flexibility of the backlight module 100. Further optionally, 140°≤c≤170°.

[0107] Secondly, please refer to Figure 9 This application provides a display device 300, which includes a backlight module 100 as described in any of the preceding embodiments and a display panel 200. The display panel 200 is disposed on the side of the optical film layer 20 facing away from the substrate 11. The display panel 200 includes a liquid crystal layer 50, and the backlight module 100 can provide a light source for the display panel 200.

[0108] The display device 300 provided in this application embodiment has the beneficial effects of the backlight module 100 in any of the foregoing embodiments. For details, please refer to the foregoing description of the beneficial effects of the backlight module 100. This application embodiment will not repeat the details.

[0109] While the embodiments disclosed in this application are as described above, the content is merely for the purpose of facilitating understanding of this application and is not intended to limit the invention. Any person skilled in the art to which this application pertains may make any modifications and changes in form and detail of the implementation without departing from the spirit and scope disclosed in this application; however, the scope of protection of this application shall still be determined by the scope defined in the appended claims.

[0110] The above description is merely a specific embodiment of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, substitutions for other connection methods described above can be made by referring to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application.

Claims

1. A backlight module, characterized in that, include: A light source substrate includes a substrate and light-emitting elements disposed on one side of the substrate, wherein a plurality of light-emitting elements are arranged in an array; An optical film layer is disposed opposite to the substrate, and the light-emitting element is located between the substrate and the optical film layer; A dam structure is disposed between the substrate and the optical film layer. The dam structure includes a reflective wall that encloses a receiving cavity, and a plurality of light-emitting elements are disposed within the plurality of the receiving cavities. A light adjustment unit is disposed within the receiving cavity and covers the light-emitting surface of the light-emitting element; At least a portion of the light emitted by the light-emitting element changes direction through the light adjustment part and propagates onto the reflective wall.

2. The backlight module according to claim 1, characterized in that, The light adjustment section includes a first arcuate surface facing the optical film layer, and the orthographic projection of the first arcuate surface on the substrate covers the orthographic projection of the light-emitting element on the substrate; The refractive index of the light adjustment part is greater than 1, and the first arc-shaped surface protrudes in the direction close to the optical film layer.

3. The backlight module according to claim 2, characterized in that, The light-adjusting section includes a first surface facing the substrate and a groove structure formed by the recess of the first surface, wherein the light-emitting element is at least partially located within the groove structure.

4. The backlight module according to claim 3, characterized in that, The first arc-shaped surface is connected to the first surface.

5. The backlight module according to claim 1, characterized in that, The reflective wall includes a second arcuate surface, which protrudes towards the receiving cavity in a direction parallel to the plane of the substrate.

6. The backlight module according to claim 5, characterized in that, The dam structure includes a first portion located between the plane containing the light-emitting surface of the light-emitting element and the optical film layer, and at least a portion of the second arc-shaped surface is located on the first portion; The width of the first portion gradually decreases in the direction away from the substrate.

7. The backlight module according to claim 5, characterized in that, The dam structure includes a first dam section and a second dam section located on the side of the first dam section away from the base. The reflective wall includes a second arcuate surface located on the first dam section and a third arcuate surface located on the second dam section. In particular, the third arc-shaped surface protrudes towards the receiving cavity in a direction parallel to the first surface.

8. The backlight module according to claim 7, characterized in that, The curvature of the third arcuate surface is greater than the curvature of the second arcuate surface.

9. The backlight module according to claim 7, characterized in that, In a direction away from the substrate, the first dam portion extends beyond the light adjustment portion.

10. The backlight module according to claim 7, characterized in that, In the thickness direction of the base, the size of the first dam portion is h1, and the size of the second dam portion is h2, where h1 and h2 satisfy: 0.4≤h2 / h1≤0.

8.

11. The backlight module according to claim 7, characterized in that, The width of the first dam section is w1, and the width of the second dam section is w2. w1 and w2 satisfy: 0.35≤w2 / w1≤0.

65.

12. The backlight module according to claim 7, characterized in that, The dam structure includes a first segment located between adjacent light-emitting elements along a first direction, a second segment located between adjacent light-emitting elements along a second direction, and an intersection segment connecting the first segment and the second segment. The first direction and the second direction intersect and are both parallel to the plane of the base. In the thickness direction of the substrate, the size of the intersection segment is larger than the size of the first segment and the second segment.

13. The backlight module according to claim 12, characterized in that, The optical film layer includes a diffusion layer, the diffusion layer includes a second surface facing the substrate, the second surface is provided with microstructures, and the cross segment is disposed in contact with the second surface.

14. The backlight module according to claim 12, characterized in that, In the thickness direction of the substrate, the cross segment extends beyond the first segment by a dimension H1, where H1 satisfies: 0.1mm ≤ H1 ≤ 0.5mm.

15. The backlight module according to claim 12, characterized in that, In the thickness direction of the substrate, the size of the intersection segment is H2, and in the first direction, the distance between adjacent light-emitting elements is t, where H2 and t satisfy: 3≤H2 / t≤4.

16. The backlight module according to claim 7, characterized in that, The dam structure also includes a third dam section disposed on the side of the second dam section away from the base, and the reflective wall includes a fourth arc-shaped surface located on the third dam section; Wherein, in the thickness direction of the base, the dimension of the second dam section is h2, and the dimension of the third dam section is h3, h2 and h3 satisfy: h3 = a * h2, 0.5 ≤ a ≤ 0.8; and / or, The width of the second dam section is w2, and the width of the third dam section is w3. w2 and w3 satisfy: w3=b*w2, 0.4≤b≤0.

9.

17. The backlight module according to claim 5, characterized in that, The substrate includes opposing first and second edges in a first direction, the first direction being parallel to the plane in which the substrate is located; The second arcuate surface includes a first sub-surface and a second sub-surface protruding in the first direction, wherein the first sub-surface is located on the side of the second sub-surface closer to the first edge; In the direction from the center of the base to the second edge, the curvature of the first sub-surface gradually decreases, and in the direction from the center of the base to the first edge, the curvature of the second sub-surface gradually decreases.

18. The backlight module according to claim 1, characterized in that, In the thickness direction of the substrate, the size of the light adjustment part is h, and in the first direction, the size of the light adjustment part is d, the first direction being parallel to the plane of the substrate; Wherein, d and h satisfy: 1.5mm≤d≤2.5mm; and / or, 0.18≤h / d≤0.

35.

19. The backlight module according to claim 1, characterized in that, The light-emitting angle of the light-emitting element is c, which satisfies: 120°≤c≤170°.

20. A display device, characterized in that, include: The backlight module as described in any one of claims 1 to 19; The display panel is disposed on the side of the optical film layer opposite to the substrate.

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