Backlight module and display device

Abstract

The application provides a backlight module and a display device. The backlight module comprises a substrate, a plurality of light sources arranged on the substrate, and a three-dimensional reflective sheet arranged on a side of the substrate provided with the light sources. The three-dimensional reflective sheet forms a plurality of reflective cavities. The openings of the reflective cavities are all arranged on the back of the substrate. The reflective cavities are enclosed by bottom walls and side walls. The light sources are arranged in the reflective cavities. The light sources extend out of the through holes on the bottom walls. At least three side walls of the reflective cavities form a convex platform. The convex platform is arranged integrally with the reflective cavities. The top end of the convex platform, which is away from the substrate, forms a convex platform plane. The convex platform plane and the side walls of the reflective cavities are in an angle or are connected through a curved surface. The backlight module and the display device according to the application can solve the problem of uneven display brightness of the backlight module.

Description

Technical Field

[0001] Some embodiments of this application relate to display technology. More specifically, they relate to a backlight module and a display device. Background Technology

[0002] In LCD display devices, the backlight module is a core component, and its main function is to provide a uniform and stable surface light source for the LCD panel to ensure clear imaging of the LCD display device.

[0003] In backlight modules, to improve light extraction efficiency and display quality, multiple LED chips are typically used as the light source, and a stereoscopic reflector is placed on the substrate to converge and guide the light emitted from the light source. This stereoscopic reflector divides the entire backlight area into multiple independent reflective cavities, each corresponding to one or a group of LED chips. The sidewalls of the reflective cavities reflect the light emitted from the light source, guiding the light to the light-emitting side, thereby optimizing light utilization.

[0004] However, the emitted light from adjacent reflective cavities converges and overlaps at the intersection of the side walls of multiple reflective cavities, which can easily lead to inconsistent brightness in this area compared to other parts, resulting in uneven light source brightness in the backlight module and affecting the display effect. Summary of the Invention

[0005] This application provides a backlight module and a display device, which aims to solve the problem of uneven brightness in the display device.

[0006] In a first aspect, some embodiments of this application provide a backlight module, the backlight module comprising: substrate; A light source, wherein there are multiple light sources, and the multiple light sources are spaced apart on the substrate; A three-dimensional reflective sheet is located on the side of the substrate where the light source is disposed. The three-dimensional reflective sheet forms multiple reflective cavities, the openings of which all face away from the substrate. Each reflective cavity is enclosed by a bottom wall and side walls. The light source is disposed in each of the reflective cavities and extends out from a through hole on the bottom wall. At least three of the sidewalls of the reflective cavities are joined together to form a boss, the boss is integrally formed with the reflective cavity, and the top of the boss facing away from the substrate forms a boss plane. The boss plane and the sidewall of the reflective cavity are joined at an angle or transitioned through a curved surface.

[0007] In the above technical solution, by setting a boss integrally formed with the reflective cavity at the intersection of at least three reflective cavity sidewalls, and the boss forming a boss plane away from the top of the substrate, on the one hand, the boss located at the light-emitting side opening of the reflective cavity and the boss with a flat top can disperse and redirect the light that was originally directly superimposed and emitted, making the light more dispersed when emitted, effectively avoiding the formation of local overly bright areas, and the planar boss has a consistent extension direction, making the guidance of the emitted light by the top of the boss uniform and controllable; on the other hand, the integrated structure of the boss and the reflective cavity makes the transition between the boss and the cavity wall uniform and eliminates the splicing gap between the two, which helps to ensure the consistency of the optical effect of the boss plane and each reflective cavity, and further improves the overall optical performance of the backlight module.

[0008] In some embodiments, a ridge is formed at the junction of the sidewalls of two adjacent reflective cavities, and a ridge plane is formed at the top of the ridge away from the substrate.

[0009] With this configuration, the convex ridge is located at the light-emitting side opening of the reflective cavity, which plays a certain role in blocking the light rays that converge at the boundary line of adjacent reflective cavities, thus scattering the light rays that would otherwise be directly superimposed and emitted. At the same time, the plane of the convex ridge can redirect the incident light rays in different directions, making the light rays more dispersed when emitted, and preventing the formation of bright lines above the boundary line of adjacent reflective cavities.

[0010] In some embodiments, the plurality of reflective cavities are arranged in a rectangular array, and the boss is located at the intersection of the sidewalls of four adjacent reflective cavities. The plane of the boss has four vertices, and the four vertices are respectively located at the position of the convex edge formed by the sidewalls of two adjacent reflective cavities.

[0011] With this configuration, the four vertices of the boss plane correspond to the positions of the four reflecting cavities. Light rays from the four reflecting cavity directions can be effectively dispersed, preventing situations where light intensity is too high in one direction and too low in other directions, thus effectively avoiding directional brightness differences. Furthermore, the regular rectangular array and the boss plane structure with four vertices facilitate mold design and manufacturing.

[0012] In some embodiments, the ratio of the distance between two opposite vertices of the boss plane to the distance between two opposite sidewalls of the reflecting cavity at the light-emitting side opening is greater than or equal to... and less than or equal to .

[0013] This design ensures that the surface of the boss has sufficient area to fully receive the light converged from the four reflective cavities and evenly disperse it, eliminating local bright spots. At the same time, it avoids the boss surface being too large and blocking the light output of the reflective cavities, ensuring both the effective light output area of ​​the reflective cavities and preventing the formation of dark spots above the boss surface, thereby ensuring the uniformity of the backlight module's brightness.

[0014] In some embodiments, the ratio of the width of the convex ridge plane along its extending direction to the distance between the opposite sidewalls of the same reflective cavity at the light-emitting side opening is greater than or equal to... .

[0015] This design ensures that the convex surface has sufficient area to fully disperse and reflect light from adjacent reflective cavities, effectively eliminating bright lines at the interface of reflective cavities and ensuring the uniformity of backlight module brightness.

[0016] In some embodiments, on the plane containing the bottom wall, the projection of the end of any side wall closer to the bottom wall is closer to the light source than the end of any side wall farther from the bottom wall.

[0017] This design increases the opening area on the light-emitting side of the reflector, which helps guide the light emitted by the light source through the reflector to the light-emitting direction, thus improving the light-emitting efficiency. At the same time, the obtuse-angled sidewall, relative to the sidewall set vertically to the bottom wall, increases the light-emitting area of ​​the reflector and can avoid the formation of dark lines above the sidewall perpendicular to the bottom wall.

[0018] In some embodiments, the sidewall includes a vertical portion and an inclined portion, the vertical portion being located on the side of the sidewall closer to the bottom wall, and the inclined portion being located on the side of the sidewall away from the bottom wall. The projection position of the end of the inclined portion closer to the bottom wall on the plane where the bottom wall is located is closer to the light source than the projection position of the end of the inclined portion away from the bottom wall on the plane where the bottom wall is located.

[0019] With this configuration, the vertical section achieves initial light mixing at the bottom of the reflective cavity, while the inclined section opens on the light-emitting side of the reflective cavity to guide and emit light. The vertical and inclined sections work together to achieve efficient and uniform light emission, making the backlight module shine evenly.

[0020] In some embodiments, the backlight module further includes a light-diffusing layer located on the light-emitting side of the stereoscopic reflector, which is used to make the light reflected by the reflective cavity emitted uniformly. The ratio of the depth of the reflecting cavity to the distance between the bottom wall of the reflecting cavity and the uniform light layer is less than or equal to... .

[0021] This configuration ensures sufficient light mixing space within the backlight module, allowing the uniform light effect of the raised surface and the raised edge surface to be further amplified through the light mixing space before reaching the uniform light layer, thereby improving the uniformity of the backlight module's brightness.

[0022] In some embodiments, the height by which the boss plane protrudes relative to the bottom wall of the reflective cavity is greater than or equal to the height by which the ridge plane protrudes relative to the bottom wall of the reflective cavity.

[0023] This configuration ensures that the height of the boss is greater than or equal to the height of the ridge, guaranteeing that the uniform light effect at the intersection of multiple reflecting cavities where light converges most strongly is no weaker than the uniform light effect at the junction of two adjacent reflecting cavities.

[0024] Secondly, this application provides a display device, including a liquid crystal display panel and a backlight module as described above, wherein the backlight module is used to provide a backlight source for the liquid crystal display panel.

[0025] The backlight module and display device provided in this application include different components such as a substrate, a light source, and a stereoscopic reflector. Multiple light sources are spaced apart on the substrate. The stereoscopic reflector is located on the side of the substrate where the light sources are located, forming multiple reflective cavities. The openings of the reflective cavities all face away from the substrate. Each reflective cavity is enclosed by a bottom wall and side walls, and a light source is disposed within each reflective cavity, extending from a through-hole on the bottom wall. A boss is formed at the intersection of the side walls of at least three reflective cavities, and the boss is integrally formed with the reflective cavity, with the top of the boss facing away from the substrate forming a boss plane.

[0026] This configuration, by incorporating protrusions integrally formed with the reflective cavities at the intersection of at least three reflective cavity sidewalls, and with the protrusions forming a planar surface away from the top of the substrate, serves two purposes. First, the planar protrusions located at the light-emitting side opening of the reflective cavities can disperse and redirect the light rays that would otherwise be directly superimposed, making the light more dispersed during emission and effectively preventing the formation of excessively bright areas. Furthermore, the consistent extension direction of the planar protrusions ensures uniform and controllable guidance of the emitted light rays by the top of the protrusions. Second, the integrated structure of the protrusions and reflective cavities ensures a uniform transition between the protrusions and the cavity walls, eliminating the seams between them. This helps ensure the consistency of the optical effects of the protrusion plane and each reflective cavity, further improving the overall optical performance of the backlight module. Attached Figure Description

[0027] To more clearly illustrate the implementation methods in some embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0028] Figure 1 This is a schematic diagram of a reflective cavity formed by a three-dimensional reflective sheet in a related technology; Figure 2 This is a cross-sectional schematic diagram of a backlight module according to an embodiment of this application; Figure 3 for Figure 2 A schematic diagram of the reflective cavity in the backlight module shown; Figure 4 This is a schematic diagram showing the matrix arrangement of reflective cavities in a backlight module according to an embodiment of this application; Figure 5 This is a schematic diagram showing the staggered arrangement of reflective cavities in a backlight module according to an embodiment of this application; Figure 6 This is a cross-sectional schematic diagram of another backlight module according to an embodiment of this application; Figure 7 for Figure 6 A schematic diagram of the reflective cavity in the backlight module shown; Figure 8 A schematic diagram illustrating the dimensions of a reflective cavity in a backlight module according to an embodiment of this application; Figure 9 A schematic diagram illustrating the dimensions of another reflective cavity in a backlight module according to an embodiment of this application; Figure 10 for Figure 7 The diagram shows a cross-sectional view of a reflective cavity along the AA direction; Figure 11 for Figure 7 Another cross-sectional view of the reflecting cavity along the AA direction is shown; Figure 12 This is a schematic diagram of the structure of a display device according to an embodiment of this application.

[0029] Explanation of reference numerals in the attached figures: 1-Substrate; 2-Light source; 3, 30-Stereoscopic reflector; 4, 40-Reflective cavity; 5-Light homogenizing layer; 41-Bottom wall; 42, 420-Side walls; 43-Boss; 44-Ribbon; 60-Intersection point; 100-Backlight module; 200-Display device; 201-Liquid crystal display panel; 202-Optical film assembly; 411-Through hole; 421-Vertical part; 422-Inclined part; 431-Boss plane; 441-Protruding ridge plane. Detailed Implementation

[0030] To make the objectives, implementation methods and advantages of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the described exemplary embodiments are only some embodiments of this application, and not all embodiments.

[0031] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0032] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclusively include, for example, a product or device that includes a series of components is not necessarily limited to those that are explicitly listed, but may include other components that are not explicitly listed or that are inherent to such product or device.

[0033] As a core component of LCD displays, the backlight module's main function is to provide a uniform, stable, and controllable light source for the LCD panel, compensating for the limitation of liquid crystal materials not possessing self-emissive properties, thereby achieving clear image presentation. Backlight modules are widely used in various terminal display devices such as televisions, monitors, automotive displays, and smartphones.

[0034] In backlight modules, to improve light extraction efficiency and display quality, multiple LED light sources are typically used, and a stereoscopic reflector is placed above the substrate to converge and guide the light emitted by each light source. This stereoscopic reflector divides the entire backlight area into multiple independent reflective cavities, each corresponding to one or a group of LED light sources. The sidewalls of the reflective cavities reflect the light emitted by the light sources, thereby precisely guiding the light to the light-emitting side and optimizing light utilization. The LED light sources can be of different forms, such as Mini-LED chips.

[0035] Figure 1 This is a schematic diagram of a reflective cavity 40 formed by a stereoscopic reflective sheet 30 in a related art. Specifically, as shown... Figure 1As shown, in the above structure, multiple reflecting cavities 40 are closely arranged, and the sidewalls 420 of adjacent reflecting cavities form ridges at their boundaries. Intersection points 60 of these ridges are formed at the intersection of the sidewalls 420 of four adjacent reflecting cavities. At these intersection points 60, the emitted light from the adjacent reflecting cavities 40 converges in the same area. Due to the superposition of light energy, the backlight brightness above these intersection points 60 is significantly higher than other areas of the reflecting cavities, forming obvious bright spots or bright patches. Because there are numerous such intersection points on the entire stereoscopic reflective sheet 30, local bright spots appear at each intersection point 60. These bright spots, along with the normal brightness of the central area of ​​the reflecting cavity 40, form an alternating pattern of light and dark, resulting in a regular grid-like unevenness of light and dark across the entire backlight surface. Furthermore, the ridges and their intersection points 60 have sharp peaks. At the ridge or intersection point 60, the reflection path of light changes drastically, that is, the reflection area of ​​one reflection cavity suddenly changes to the reflection area of ​​an adjacent reflection cavity. The lack of a smooth optical transition makes the boundary between light and dark between adjacent reflection cavities obvious, further aggravating the non-uniformity of backlight.

[0036] Based on this, the backlight structure of the embodiments of this application eliminates the sharp peak structure at the intersection of the ridges of each reflective cavity and replaces it with a protruding plane with a certain area, thereby eliminating the bright spot above the intersection of the ridges and improving the uniformity of the backlight.

[0037] Figure 2 This is a cross-sectional schematic diagram of a backlight module 100 according to an embodiment of this application. Figure 2 As shown, the backlight module includes a substrate 1, a light source 2, a stereo reflector 3, and other structures.

[0038] The substrate 1 serves as the structural foundation and electrical carrier of the backlight module 100, supporting the light source 2 and providing electrical connection to it. The substrate 1 is generally flat and can be rectangular, square, or other shapes. The surface of the substrate 1 can be planar or slightly curved; for example, in a backlight module 100 suitable for curved displays, the substrate 1 can have a certain radius of curvature. The substrate 1 can be a single-layer or multi-layer composite structure. Along the thickness direction of the substrate 1, one side can be used to mount the light source 2, while the other side can be used for heat dissipation or fixation.

[0039] There are multiple light sources 2, and these multiple light sources 2 are spaced apart on one side of the substrate 1. For example, the multiple light sources 2 are arranged in an array along the plane of the substrate, thus forming a light source array on the substrate 1. The light source array formed by the light sources 2 can be arranged in different ways, such as a rectangle. For example, the multiple light sources 2 can be arranged in a matrix, with multiple light sources 2 in each row and each column, and the positions of the light sources 2 in the same row and column are all on the same straight line; or the multiple light sources 2 can be arranged in multiple rows and columns, but the positions of the light sources 2 in each row or column are staggered, thus presenting a staggered arrangement, etc. The multiple light sources 2 can be arranged in other common ways, which will not be described in detail here.

[0040] The light source 2 can be a blue LED chip, which converts blue light into white light using phosphors, thereby providing white backlight to the backlight module 100; alternatively, it can be a combination light source containing at least red, green, and blue chips, which mixes red, green, and blue to form white light or other colors, making the backlight of the backlight module 100 white. Each light source 2 can include one or more sets of light-emitting chips for emitting light into the reflective cavity 4.

[0041] A three-dimensional reflective sheet 3 is located on the side of the substrate 1 where the light source 2 is located. The three-dimensional reflective sheet 3 has a three-dimensional structure, and its overall outline can match the shape of the substrate 1. The three-dimensional reflective sheet 3 can be made of a high-reflectivity thin film, or a film can be coated or coated on the surface of the thin film to obtain better reflective or diffuse reflection characteristics. The three-dimensional reflective sheet 3 can be a single-layer or multi-layer composite sheet, and multiple reflective cavities 4 can be formed by stamping, injection molding, or thermoforming processes. The openings of the reflective cavities 4, i.e., the light-emitting side, all face away from the substrate 1.

[0042] Figure 3 This is a schematic diagram of the reflective cavity 4 in the backlight module 100. (See diagram below.) Figure 3 As shown, the reflecting cavity 4 is enclosed by a bottom wall 41 and a side wall 42. Through the reflection effect of the bottom wall 41 and the side wall 42, it collects light emitted from the light source 2 in various directions and guides the light to the output direction, improving the utilization rate and directionality of the light. Simultaneously, the reflecting cavity 4 also acts as a separator, achieving optical isolation between adjacent dimming zones through the side wall 42, reducing crosstalk and ensuring independent dimming effects for each zone. The size of the bottom wall 41 of the reflecting cavity 4 is smaller than the size of the light-emitting side opening of the reflecting cavity 4. The bottom wall 41 can be a flat surface or a slightly convex or slightly concave curved surface. The bottom wall 41 can be provided with a through hole 411, through which the light source 2 extends into the reflecting cavity 4. Figure 3In the illustrated embodiment, the side wall 42 of the reflection cavity 4 is a plane. In other embodiments, the side wall 42 of the reflection cavity 4 may also be a curved surface. The edge of the side wall 42 at the opening of the reflection cavity 4 may be a straight line or a curve, and the cross-sectional profile of the side wall 42 parallel to the depth direction of the reflection cavity 4 may also be a straight line or a curve. The side walls 42 of the reflection cavity 4 may intersect at a fold angle or transition through a curved surface.

[0043] It can be understood that with different arrangements of the multiple light sources 2, the reflection cavities 4 of the three-dimensional reflection sheet 3 can have various different shapes and arrangements. For example, when there are multiple light sources 2 and they are arranged at intervals in an array on the substrate 1, correspondingly, the reflection cavities 4 can also be arranged in a matrix. Figure 4 FIG. is a schematic diagram of the reflection cavities 4 in the backlight module 100 according to an embodiment of the present application being arranged in a matrix. At this time, as Figure 4 shown, in order to reduce the distance between adjacent reflection cavities, the projected shape of the reflection cavity 4 on the substrate 1 can be rectangular. Correspondingly, the four side edges of each rectangular reflection cavity 4 are closely adjacent to the adjacent reflection cavities, forming an arrangement matrix with rows and columns neatly aligned. And correspondingly, an adjacent intersection is generated between every four adjacent rectangular reflection cavities 4. When the light sources 2 are arranged in a staggered manner on the substrate 1, in order to allow the reflection cavity 4 to be adjacent to other nearby reflection cavities 4, the projected shape of the reflection cavity 4 on the substrate 1 can be various different shapes such as a hexagon. Figure 5 FIG. is a schematic diagram of the reflection cavities 4 in the backlight module 100 according to an embodiment of the present application being arranged in a staggered manner. As Figure 5 shown, when the reflection cavity 4 is set as a regular hexagon, the six sides of each hexagonal cavity are adjacent to six surrounding cavities respectively, and any three adjacent reflection cavities 4 will intersect at a point, forming a tight "pin" - shaped arrangement structure.

[0044] Therefore, depending on the shape and arrangement of the reflective cavities 4, at least three adjacent reflective cavities 4 will form adjacent intersection points. Since the light source 2 in each reflective cavity 4 will emit light, these adjacent intersection points will form local bright spots with high brightness. To improve this situation, in this application, a protrusion 43 is formed at the intersection of the sidewalls 42 of at least three reflective cavities 4. The protrusion 43 is a three-dimensional structure formed by the sidewalls 42 belonging to different reflective cavities 4 protruding in the light-emitting direction at the intersection. The protrusion 43 and the reflective cavity 4 are integrally formed, so the material of the protrusion 43 is the same as the material of the three-dimensional reflective sheet 3 forming the reflective cavity 4, thereby ensuring that the reflective characteristics of the surface of the protrusion 43 are consistent with the reflective characteristics of the sidewalls 42 of the reflective cavity 4. A protrusion plane 431 is formed at the top of the protrusion 43 away from the substrate 1. The protrusion plane 431 and the sidewall 42 of the reflective cavity 4 can be at an angle or through a curved transition. The protruding plane 431 is positioned at the light-emitting side opening of the reflecting cavity 4, providing a certain degree of light blocking and dispersing the light rays that would otherwise be directly superimposed, preventing them from converging at a single point. Furthermore, the protruding plane 431 can redirect the incident light rays in different directions, further dispersing them upon emission and preventing the formation of excessively bright areas. The protruding plane 431 can be circular, square, or other polygonal planes. The edges of the protruding plane 431 can be straight or curved.

[0045] In the backlight module according to the embodiments of this application, by providing a boss integrally formed with the reflective cavity at the intersection of at least three reflective cavity sidewalls, and forming a boss plane away from the top of the substrate, the uniformity of backlight can be significantly improved. On the one hand, the boss plane is located at the light-emitting side opening of the reflective cavity, which can play a certain role in blocking the light, dispersing the light that was originally directly superimposed and emitted, so that it no longer concentrates at a point; on the other hand, the boss plane can redirect the incident light in different directions, making the light more dispersed when emitted, effectively avoiding the formation of local overly bright areas. Compared with the top surface of the curved boss with a certain curvature, the planar boss has a consistent extension direction, making the guidance of the emitted light by the top of the boss uniform and controllable. In addition, the integrated structure of the boss and the reflective cavity makes the transition between the boss and the cavity wall uniform and eliminates the splicing gap between the two, which helps to ensure the consistency of the optical effect of the boss plane and each reflective cavity, and further improves the overall optical performance of the backlight module.

[0046] The technical solution of this application will be described in detail below with reference to specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0047] Figure 6 This is a cross-sectional schematic diagram of another backlight module 100 according to an embodiment of this application. Figure 7 for Figure 6 A schematic diagram of the reflective cavity 4 in the backlight module 100 shown.

[0048] In some embodiments, such as Figure 7 As shown, a raised ridge 44 is formed at the junction of the sidewalls 42 of two adjacent reflective cavities 4, and a raised ridge plane 441 is formed at the top of the raised ridge 44 facing away from the substrate 1. The raised ridge plane 441 extends along the junction line of the sidewalls 42 of two adjacent reflective cavities 4. The raised platform plane 431 and the sidewall 42 of the reflective cavity 4 can be at an angle or transitioned through a curved surface. The raised ridge plane 441, the bottom wall 41 and the sidewalls 42 of the reflective cavity 4, and the raised platform plane 431 are all formed by three-dimensional reflective sheets 3, and have the same reflective characteristics, thereby achieving uniform and consistent reflection inside and on the surface of the reflective cavity 4.

[0049] Even with a protrusion 43 at the intersection of the two reflecting cavities 4, localized light enhancement may still occur between the sidewalls 42 of adjacent reflecting cavities 4, forming a bright line above the boundary between the two adjacent reflecting cavities 4. Similar to the protrusion plane 431, the convex ridge plane 441 disperses and reflects the light superimposed at the boundary between the two adjacent reflecting cavities 4. On one hand, the convex ridge plane 441, located at the light-emitting side opening of the reflecting cavity 4, acts as a certain shielding for the light, breaking up the light that was originally directly superimposed and emitted, preventing it from converging at the boundary between adjacent reflecting cavities 4. On the other hand, the convex ridge plane 441 can redirect incident light from different directions to different directions, making the light more dispersed when emitted, thus avoiding the formation of a bright line above the boundary between adjacent reflecting cavities 4.

[0050] The convex ridge plane 441 and the boss plane 431 cooperate to achieve a uniform light effect at all the intersections and junctions of the reflective cavity array, improve the uniformity of the backlight, and effectively reduce the bright and dark stripes in the backlight.

[0051] In some embodiments, such as Figure 3 and Figure 7As shown, multiple reflecting cavities 4 can be arranged in a rectangular array. The light-emitting side opening of the reflecting cavity 4 is quadrilateral, specifically a rectangle or a square. This rectangular array can be regularly arranged along two mutually perpendicular directions of the substrate 1 to form a regular structure. In this rectangular array arrangement, every four adjacent reflecting cavities 4 share an intersection point, which is the location of the boss 43, allowing the boss 43 to accurately correspond to the spatial position of the four reflecting cavities 4. Specifically, the boss 43 is located at the intersection of the sidewalls 42 of four adjacent reflecting cavities 4. The boss plane 431 has four vertices, which correspond to the convex ridge positions formed by the sidewalls 42 of two adjacent reflecting cavities 4. These convex ridge positions can be the convex ridge plane 441 or the ridge line formed by the intersection of adjacent sidewalls 420. The overall shape of the boss plane 431 can be a rhombus, square, rectangle, or other suitable quadrilateral, depending on the actual light uniformity and processing requirements. The four sides of the quadrilateral can be straight lines or concave or convex arcs.

[0052] Each reflecting cavity 4 reflects and guides the light emitted from the light source 2. The outgoing light rays from four adjacent reflecting cavities 4 converge at the intersection area, and the boss plane 431 evenly disperses the converged light rays in all directions. Since the four vertices of the boss plane 431 precisely correspond to the positions of the four reflecting cavities 4, the light rays in the four directions can be effectively dispersed, preventing situations where the light intensity in one direction is too high and the light intensity in other directions is too low, effectively avoiding directional brightness differences. In addition, the regular rectangular array and the boss plane structure with four vertices of 431 are beneficial to the design and processing of the mold.

[0053] In some embodiments, the multiple reflecting cavities 4 can also be arranged in a honeycomb array, that is, the light-emitting side opening of the reflecting cavity 4 is a regular hexagon. The boss 43 can be located at the intersection between the sidewalls 42 of three adjacent reflecting cavities 4, and the three vertices of the boss plane 431 can be respectively located at the intersection between the sidewalls 42 of two adjacent reflecting cavities 4.

[0054] Figure 8 A schematic diagram showing the dimensions of a reflective cavity 4 in a backlight module 100 according to an embodiment of this application is provided. Figure 8 As shown, in some embodiments, the ratio of the distance H1 between two opposite vertices of the boss plane 431 to the distance H2 between the opposite side walls 42 of the reflecting cavity 4 at the light-emitting side opening is greater than or equal to... and less than or equal to .

[0055] The matching degree between the size of the boss plane 431 and the opening size of the reflective cavity 4 determines the uniformity of the brightness of the backlight module 100. If the area of ​​the boss plane 431 is too small, that is, the ratio of the distance between two relative vertices of the boss plane 431 to the distance at the corresponding opening of the reflective cavity 4 is too small, it will result in the inability to effectively disperse the light converged there and make the converged light from the four adjacent reflective cavities 4 emitted uniformly in different directions. Therefore, there will still be local bright spots at the intersection of the reflective cavities 4, and the uniform light effect will not meet expectations. If the area of ​​the boss plane 431 is too large, that is, the ratio of the distance between two relative vertices of the boss plane 431 to the distance at the corresponding opening of the reflective cavity 4 is too large, the boss plane 431 will excessively occupy the light emission space of the reflective cavity 4, blocking too much of the effective light emission area. This will not only reduce the amount of light emitted by each reflective cavity 4 and decrease the overall backlight brightness, but will also form dark spots above the boss plane 431.

[0056] Limit the ratio to greater than or equal to and less than or equal to Within the range, it can ensure that the boss plane 431 has a sufficient area to fully receive the light converged by the four reflective cavities 4 and disperse it evenly to eliminate local bright spots; at the same time, it can prevent the boss plane 431 from blocking the light output of the reflective cavity 4 too much, thus ensuring the effective light output area of ​​the reflective cavity 4 and preventing the formation of dark spots above the boss plane 431, thereby ensuring the brightness uniformity of the backlight module 100.

[0057] Figure 9 This is a schematic diagram illustrating the dimensions of another reflective cavity 4 in the backlight module 100 according to an embodiment of this application. Figure 9 As shown, in some embodiments, the ratio of the width H3 of the convex plane 441 along its extending direction to the distance H4 of the opposite side walls 42 of the same reflecting cavity 4 at the light-emitting side opening is greater than or equal to... The matching degree between the width of the convex plane 441 and the opening size of the reflective cavity 4 determines the brightness uniformity and light energy utilization efficiency of the backlight module 100.

[0058] If the width of the convex ridge plane 441 is too small, that is, the ratio of the width of the convex ridge plane 441 in the extension direction of the convex ridge 44 to the distance between the opposite side walls 42 of the reflective cavity 4 at the light-emitting side opening is too small, the effective working area of ​​the convex ridge plane 441 will be insufficient, and it will be unable to effectively disperse and reflect the edge light from the adjacent reflective cavity 4. A bright line will be formed above the junction of the side walls 42 of the reflective cavity 4, which will destroy the backlight uniformity and affect the display effect.

[0059] Limit the ratio to greater than or equal to Within the range, it can ensure that the convex plane 441 has a sufficient effective working area, which can fully disperse and reflect the edge light from the adjacent reflective cavity 4, effectively eliminate the bright line above the junction of the reflective cavity 4, and ensure the brightness uniformity of the backlight module 100.

[0060] Figure 10 for Figure 7 The diagram shows a cross-sectional view of a reflecting cavity along the AA direction. In some embodiments, such as... Figure 7 and Figure 10 As shown, on the plane where the bottom wall 41 is located, the projection position of the end of the side wall 42 closer to the bottom wall 41 is closer to the light source 2 than the projection position of the end of the side wall 42 farther from the bottom wall 41. That is, the extension direction of the plane where the side wall 42 is located forms an obtuse angle with the extension direction of the plane where the bottom wall 41 is located.

[0061] In some embodiments, the sidewall 42 and the bottom wall 41 of the reflecting cavity 4 can be at an angle or transitioned by a curved surface. The sidewall 42 of the reflecting cavity 4 gradually extends outward from the bottom wall 41 toward the light-emitting side opening, forming a structure in which the light-emitting side opening of the reflecting cavity 4 is larger than the bottom. This facilitates the reflection of the lateral light emitted by the light source 2 and guides it toward the light-emitting direction, thereby improving the light-emitting efficiency. This configuration increases the area of ​​the light-emitting side opening of the reflecting cavity, which is beneficial for guiding the lateral light emitted by the light source 2 toward the light-emitting direction and improving the light-emitting efficiency. At the same time, the obtuse-angled sidewall 42, relative to the sidewall 42 perpendicular to the bottom wall 41, increases the light-emitting area of ​​the reflecting cavity 4 and can avoid the formation of dark lines above the sidewall 42 perpendicular to the bottom wall 41.

[0062] In some embodiments, the sidewalls are inclined or curved.

[0063] In some embodiments, the curved surface protrudes into the interior of the boss. This shape is more conducive to the distribution of light in the display area corresponding to the reflective cavity.

[0064] In some embodiments, the curvature of the surface is configured such that light reflected from the surface can be incident on the opposite sidewall of the light source axis before reaching the homogenizing film. Compared to a single-color light source where the sidewall reflects the light source to meet the requirement of proximity to the local side, in cases where the chips of multi-color backlights have different spatial arrangements, the fact that light reflected from the surface can be incident on the opposite sidewall of the light source axis before reaching the homogenizing film allows for more uniform mixing of different colors of light. Here, the light source axis refers to the axis of the light source perpendicular to the substrate.

[0065] Figure 11 for Figure 7 Another cross-sectional view of the reflecting cavity along the AA direction is shown. In some embodiments, such as Figure 7 and Figure 11As shown, the sidewall 42 may include a vertical portion 421 and an inclined portion 422. The vertical portion 421 is located on the side of the sidewall 42 near the bottom wall 41 and extends in a direction perpendicular to the bottom wall 41.

[0066] In some embodiments, the vertical portion 421 forms a vertical reflective wall around the light source 2, making it easier for light to be reflected in the bottom region toward the side of the light source axis facing the opposite side wall, which can increase the number of light mixing times and help improve the light uniformity in the bottom region.

[0067] In some embodiments, the inclined portion 422 is located on the side of the sidewall 42 away from the bottom wall 41. The projection position of the end of the inclined portion 422 near the bottom wall 41 on the plane of the bottom wall 41 is closer to the light source 2 than the projection position of the end of the inclined portion 422 away from the bottom wall 41 on the plane of the bottom wall 41. That is, the inclined portion 422 extends outward from the top of the vertical portion 421 to the light-emitting side opening of the reflective cavity 4. The inclined portion 422 guides the light after bottom mixing in the light-emitting direction, so that the light can be effectively emitted from the opening of the reflective cavity 4.

[0068] In some embodiments, the junction between the inclined portion 422 and the vertical portion 421 can be a folded junction or a smooth arc transition.

[0069] In some embodiments, the junction between the vertical portion 421 and the bottom wall 41 can be a folded junction or a smooth arc transition.

[0070] In some embodiments, the sum of the height of the vertical portion 421 and the height of the inclined portion 422 is equal to the total height of the sidewall 42, i.e., the depth of the reflecting cavity 4.

[0071] In some embodiments, the vertical portion 421 achieves preliminary mixing of multi-primary-color backlight at the bottom of the reflective cavity 4, and the inclined portion 422 opens on the light-emitting side of the reflective cavity 4 to guide and emit light, resulting in good uniformity of the light-emitting surface. The vertical portion 421 and the inclined portion 422 cooperate to achieve efficient and uniform light emission in the case of multiple primary colors, making the backlight module 100 shine evenly. That is, each color of backlight can be emitted uniformly.

[0072] In some embodiments, the vertical portion 421 is a plane.

[0073] In some embodiments, the inclined portion 422 is a plane or a curved surface.

[0074] In some embodiments, the distance between the boss plane 431 and the bottom wall 41 of the reflecting cavity 4 is equal to the depth of the reflecting cavity 4, and the boss plane 431 and the light-emitting opening plane of the reflecting cavity 4 are at the same horizontal height. The depth of the reflecting cavity 4 is the vertical distance from the bottom wall 41 of the reflecting cavity 4 to its light-emitting opening plane, that is, the height dimension of the reflecting cavity 4 perpendicular to the light-emitting direction.

[0075] If the distance between the boss plane 431 and the bottom wall 41 of the reflecting cavity 4 is less than the depth of the reflecting cavity 4, that is, the boss plane 431 is lower than the light-emitting side opening plane of the reflecting cavity 4, then after the light is reflected in the reflecting cavity 4, it cannot be fully blocked and dispersed by the boss plane 431 when it is emitted. The light still converges above the boss plane 431, resulting in a bright spot above the boss plane 431. If the distance between the boss plane 431 and the bottom wall 41 of the reflecting cavity 4 is greater than the depth of the reflecting cavity 4, that is, the boss plane 431 is higher than the light-emitting side opening plane of the reflecting cavity 4, then the boss plane 431 will protrude from the light-emitting path of the reflecting cavity 4 and block the effective light-emitting area of ​​the reflecting cavity 4, resulting in a reduction in the amount of light emitted by each reflecting cavity 4, a decrease in the overall backlight brightness, and possibly the formation of a dark spot above the boss plane 431.

[0076] This configuration allows the boss plane 431 to be flush with the light-emitting side opening plane of the reflective cavity 4. The boss plane 431, acting as a light-uniforming platform at the same height as the light-emitting surface, effectively blocks and disperses the light rays converging above the light-emitting surface. Furthermore, the flush structure between the boss plane 431 and the light-emitting surface of the reflective cavity 4 provides a flat and uniform reference surface for optical components such as the optical film layer above the backlight module 100, simplifying the design and installation of subsequent optical components.

[0077] In some embodiments, such as Figure 3 and Figure 7 As shown, the backlight module 100 also includes a light-diffusing layer 5. The light-diffusing layer 5 has a sheet-like or plate-like structure and is located on the light-emitting side of the stereoscopic reflector 3. It can be planar or curved. The outline dimensions of the light-diffusing layer 5 are adapted to the overall outline dimensions of the reflective cavity 4 or the substrate 1. The light-diffusing layer 5 is used to make the light reflected from the reflective cavity 4 emitted uniformly, and can further smooth and diffuse the slight non-uniformities emitted from the reflective cavity 4, thereby making the brightness distribution of the light finally reaching the display panel extremely uniform.

[0078] The ratio of the depth H5 of the reflecting cavity 4 to the distance H6 between the bottom wall 41 of the reflecting cavity 4 and the uniform light layer 5 is less than or equal to The depth of the reflecting cavity 4 is the vertical distance from the bottom wall 41 of the reflecting cavity 4 to its light-emitting opening plane. The distance between the bottom wall 41 of the reflecting cavity 4 and the homogenizing layer 5 is the mixing distance, which is the vertical spatial distance of light from the light source 2 to the homogenizing layer 5. In addition to the depth of the reflecting cavity 4, the mixing distance also includes a portion of the free mixing space between the outlet of the reflecting cavity 4 and the homogenizing layer 5. The free mixing space allows the light emitted from the reflecting cavity 4 to undergo spatial mixing before reaching the homogenizing layer 5, reducing the brightness contrast of the light incident on the homogenizing layer 5. When the ratio of the depth of the reflecting cavity 4 to the mixing distance is too large, i.e., when the homogenizing layer 5 is too close to the reflecting cavity 4, it means that the free mixing space is insufficient, and the brightness pattern of the light-emitting side opening of the reflecting cavity 4 may be directly mapped onto the homogenizing layer 5, affecting the final light emission uniformity.

[0079] This configuration ensures that there is sufficient free light mixing space within the backlight module 100, allowing the uniform light effect of the raised surface 431 and the raised edge surface 441 to be further amplified through the free light mixing space before reaching the uniform light layer 5, thereby improving the uniformity of the brightness of the backlight module 100.

[0080] In some embodiments, the height by which the boss plane 431 protrudes relative to the bottom wall 41 of the reflecting cavity 4 is greater than or equal to the height by which the ridge plane 441 protrudes relative to the bottom wall 41 of the reflecting cavity 4. The height by which the boss plane 431 protrudes relative to the bottom wall 41 of the reflecting cavity 4 refers to the vertical distance from the boss plane 431 to the bottom wall 41 of the reflecting cavity 4, i.e., the height of the boss 43. The height by which the ridge plane 441 protrudes relative to the bottom wall 41 of the reflecting cavity 4 refers to the vertical distance from the ridge plane 441 to the bottom wall 41 of the reflecting cavity 4, i.e., the height of the ridge 44. Since the light convergence intensity is greater at the intersection of multiple reflecting cavities 4, i.e., at the location of the boss plane 431, than at the junction of two adjacent reflecting cavities 4, i.e., at the location of the ridge plane 441, the boss plane 431 can be set to be at least equal to or higher than the ridge plane 441. This ensures that the boss plane 431 can preferentially or effectively block and disperse the converged light, thus exerting a stronger light-uniforming effect.

[0081] This configuration ensures that the height of the protrusion 43 is greater than or equal to the height of the protrusion 44, guaranteeing that the uniform light effect at the intersection of multiple reflecting cavities 4 where the light converges most strongly is not weaker than the uniform light effect at the junction of two adjacent reflecting cavities 4.

[0082] In some embodiments, each boss 43 may be configured to have the same height. In other embodiments, each boss 43 may be configured to have different heights. For example, the height of some bosses 43 may be set higher than the height of other bosses 43, and the distance between the light-diffusing layer 5 and the bottom wall 41 of the reflective cavity 4 may be the same, so that the bosses 43 abut against the light-diffusing layer 5 and provide stable support for the light-diffusing layer 5. By providing support for the light-diffusing layer 5 with the bosses 43, the use of support pillars for supporting the light-diffusing layer 5 can be reduced, simplifying the overall structure of the backlight module 100; at the same time, it can provide balanced support for the light-diffusing layer 5, ensuring that the light-diffusing layer 5 is flat. In order to avoid the bosses 43 directly contacting the light-diffusing layer 5 and forming dark spots, the bosses 43 in contact with the light-diffusing layer 5 may be in the shape of a pyramid or cone, extending from the light-emitting plane of the reflective cavity 4 to the light-diffusing layer 5, and tapering to a pointed top at the top of the bosses 43 to reduce the direct contact area with the light-diffusing layer 5.

[0083] Figure 12 This is a schematic diagram of the structure of a display device 200 according to an embodiment of this application. The display device 200 can be applied to various electronic devices requiring image display functions, such as mobile phones, tablets, laptops, monitors, televisions, and in-vehicle display devices. Its core function is to convert electrical signals into visible images, providing users with a clear and stable display effect. The components of the display device 200 will be described in detail below.

[0084] like Figure 12 As shown, the display device 200 may include a backlight module 100 and a liquid crystal display panel 201.

[0085] The backlight module 100 is used to provide a backlight source for the liquid crystal display panel 201.

[0086] The liquid crystal display panel 201 is disposed on the light-emitting side of the backlight module 100 and is used to receive external driving signals and convert them into visible images. The liquid crystal display panel 201 may include a liquid crystal driving circuit (not shown in the figure) and a plurality of liquid crystal molecules. The liquid crystal driving circuit can apply a voltage to the liquid crystal molecules, so that the liquid crystal molecules can be deflected to transmit or block the light emitted by the backlight module 100.

[0087] The display device 200 may further include an optical film assembly 202, which is disposed between the liquid crystal display panel 201 and the backlight module 100. The optical film assembly 202 may include one or more combinations of diffusers, prism sheets, polarizers, etc.

[0088] In some embodiments of the display device provided in this application, by providing a boss integrally formed with the reflective cavity at the intersection of at least three reflective cavity sidewalls, and forming a boss plane away from the top of the substrate, the backlight uniformity can be significantly improved. On the one hand, the boss plane is located at the light-emitting side opening of the reflective cavity, which can play a certain role in blocking the light, dispersing the light that was originally directly superimposed and emitted, so that it no longer concentrates at a point; on the other hand, the boss plane can redirect the incident light in different directions, making the light more dispersed when emitted, effectively avoiding the formation of local overly bright areas. Compared with the top surface of a curved boss with a certain curvature, the manufacturing of a planar boss is simpler and more controllable, making the guidance of the emitted light by the top of the boss more uniform and controllable. In addition, the integrated structure of the boss and the reflective cavity makes the transition between the boss and the cavity wall uniform and eliminates the splicing gap between the two, which helps to ensure the consistency of the optical effect of the boss plane and each reflective cavity, and further improves the overall optical performance of the backlight module.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0090] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the described embodiments and various different variations of embodiments suitable for specific use considerations.

Claims

1. A backlight module, characterized in that, The backlight module includes: substrate; The light source comprises multiple light sources, which are spaced apart on the substrate. Each light source includes a light-emitting chip of a different color, and the light-emitting chips of different colors are arranged in different spatial positions. The light-emitting chips of different colors form white light or other colors of light by mixing red, green and blue. A three-dimensional reflective sheet is located on the side of the substrate where the light source is disposed. The three-dimensional reflective sheet forms multiple reflective cavities, the openings of which all face away from the substrate. Each reflective cavity is enclosed by a bottom wall and side walls. The light source is disposed in each of the reflective cavities and extends from a through hole on the bottom wall, wherein the bottom wall is a plane. A light-diffusing layer, which is planar and located on the light-emitting side of the stereoscopic reflector, is used to make the light reflected by the reflective cavity emit uniformly. Multiple reflective cavities are arranged in a rectangular array. A boss is formed at the intersection of the sidewalls of four adjacent reflective cavities. The boss and the reflective cavity are integrally formed, and the top of the boss away from the substrate forms a boss plane. The boss plane and the sidewall of the reflective cavity are at an angle or transitioned through a curved surface. The boss plane has four vertices, which are respectively located on the convex ridge formed by the sidewalls of two adjacent reflective cavities. The line connecting two adjacent vertices forms the edge of a corner of a reflective cavity. The width of the convex ridge is smaller than the width of the boss.

2. The backlight module according to claim 1, characterized in that, The protruding ridge forms a protruding ridge plane opposite to the top of the substrate.

3. The backlight module according to claim 2, characterized in that, The ratio of the distance between two opposite vertices of the protrusion plane to the distance between two opposite sidewalls of the reflecting cavity at the light-emitting side opening is greater than or equal to... and less than or equal to .

4. The backlight module according to claim 2, characterized in that, The ratio of the width of the convex ridge plane along its extending direction to the distance between the two opposite sidewalls of the same reflecting cavity at the light-emitting side opening is greater than or equal to... .

5. The backlight module according to any one of claims 1-4, characterized in that, On the plane containing the bottom wall, the projection of the end of any side wall closer to the bottom wall is closer to the light source than the end of any side wall farther from the bottom wall.

6. The backlight module according to any one of claims 1-4, characterized in that, The sidewall includes a vertical portion and an inclined portion. The vertical portion is located on the side of the sidewall closer to the bottom wall, and the inclined portion is located on the side of the sidewall away from the bottom wall. The projection position of the end of the inclined portion closer to the bottom wall on the plane where the bottom wall is located is closer to the light source than the projection position of the end of the inclined portion away from the bottom wall on the plane where the bottom wall is located.

7. The backlight module according to any one of claims 1-4, characterized in that, The ratio of the depth of the reflecting cavity to the distance between the bottom wall of the reflecting cavity and the uniform light layer is less than or equal to... .

8. The backlight module according to claim 2 or 4, characterized in that, The height by which the boss plane protrudes relative to the bottom wall of the reflective cavity is greater than or equal to the height by which the ridge plane protrudes relative to the bottom wall of the reflective cavity.

9. A display device, characterized in that, include: LCD display panel; The backlight module according to any one of claims 1-8, wherein the backlight module is used to provide a backlight source for the liquid crystal display panel.

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