Backlight module and display device

Abstract

A backlight module and a display device. The backlight module comprises a base substrate (10), a protruding structure (11), a first reflective layer (20), a second reflective layer (30), and a light-emitting device (40). The backlight module further comprises at least one of a light blocking portion (51) and a color conversion portion (52), wherein the light blocking portion (51) is located on the side of the second reflective layer (30) close to a second surface (102), the light blocking portion (51) is provided with a second through hole (51a), the orthographic projection of the second through hole (51a) onto the second surface (102) at least partially overlaps the orthographic projection of a first through hole (30a) onto the second surface (102), the orthographic projection of the second through hole (51a) onto the second surface (102) at least partially overlaps the orthographic projection of the first reflective layer (20) onto the second surface (102), the color conversion portion (52) is located on the side of the second reflective layer (30) close to the second surface (102), and the orthographic projection of the color conversion portion (52) onto the second surface (102) at least partially overlaps the orthographic projection of the first through hole (30a) onto the second surface (102).

Description

Backlight module and display device TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a backlight module and a display device. BACKGROUND

[0002] With the development of light emitting diode technology, backlight modules using light emitting diodes (LED) of sub-millimeter (Mini) level or even micrometer (Micro) level have been widely applied. As a result, not only can the picture contrast of products such as liquid crystal displays (LCD) using the backlight module reach the level of organic light emitting diode (OLED) display products, but also the products can retain the technical advantages of liquid crystal display, thereby improving the display effect of the picture and providing users with better visual experience. SUMMARY

[0003] The embodiment provides a backlight module, comprising:

[0004] a substrate, comprising opposite first and second surfaces, wherein the first surface is provided with a first groove;

[0005] a convex structure located in the first groove and arranged in a spaced manner with respect to the opening edge of the first groove; in the direction in which the first surface points to the second surface, the area of the cross section of the convex structure parallel to the second surface gradually increases;

[0006] a first reflective layer located in the first groove and covering at least the side surface of the convex structure and exposing at least part of the side surface of the first groove;

[0007] a second reflective layer located on the side of the substrate away from the second surface, wherein the second reflective layer is provided with a first through hole, and the orthogonal projection of the first through hole on the second surface of the substrate overlaps with the orthogonal projection of the first groove on the second surface of the substrate;

[0008] a light emitting device located on the same side of the substrate as the second reflective layer, wherein the light emitted by the light emitting device enters the first groove through the first through hole;

[0009] The backlight module further comprises at least one of a light blocking part and a color conversion part;

[0010] The light blocking portion is located on the side of the second reflective layer near the second surface. The light blocking portion is provided with a second through hole. The orthographic projection of the second through hole on the second surface at least partially overlaps with the orthographic projection of the first through hole on the second surface. The orthographic projection of the second through hole on the second surface at least partially overlaps with the orthographic projection of the first reflective layer on the second surface.

[0011] The color conversion section is located on the side of the second reflective layer near the second surface, and the orthographic projection of the color conversion section on the second surface at least partially overlaps with the orthographic projection of the first through hole on the second surface.

[0012] In some embodiments, the backlight module includes a light blocking portion, at least a portion of which is located within the first groove.

[0013] In some embodiments, the backlight module includes a light blocking portion, the outer contour of the orthographic projection of the light blocking portion on the second surface being located inside the edge of the orthographic projection of the first groove on the second surface.

[0014] In some embodiments, the backlight module includes a light blocking portion, wherein the orthographic projection of the first through-hole of the second reflective layer on the second surface is located within the orthographic projection of the second through-hole of the light blocking portion on the second surface.

[0015] In some embodiments, the backlight module includes a light blocking portion, wherein the orthographic projection of the second through hole of the light blocking portion on the second surface is located within the orthographic projection of the first reflective layer on the second surface.

[0016] In some embodiments, in the direction from the first surface to the second surface, the distance between the side of the second through hole near the second surface and the surface of the first reflective layer away from the second surface is H1, the distance between the outer contour of the second through hole projected onto the second surface and the outer contour of the first reflective layer projected onto the second surface is X1, and the ratio of X1 to H1 is greater than 0.7.

[0017] In some embodiments, the backlight module includes a color conversion section; the color conversion section is located on the side of the protruding structure away from the second surface, and the light blocking section is disposed around the color conversion section, wherein...

[0018] The distance between the side of the color conversion part near the second surface and the second surface is greater than or equal to the distance between the end of the second through hole near the second surface and the second surface;

[0019] Alternatively, the distance between the side of the color conversion part near the second surface and the second surface is less than the distance between the end of the second through hole near the second surface and the second surface. The first plane is perpendicular to the second surface and passes through the geometric center of the orthographic projection of the second through hole on the second surface. One point of the boundary of the first reflective layer on the first plane away from the second surface is the first boundary point. One point of the boundary of the second through hole on the first plane near the second surface is the second boundary point. The first boundary point and the second boundary point are located on the same side of the cross-section of the protruding structure on the first plane. The straight line segment connecting the first boundary point and the second boundary point is the first boundary line. The outer contour of the part of the color conversion part on the first plane that exposes the second through hole and faces the first reflective layer is located on the first boundary line or on the side of the first boundary line near the protruding structure.

[0020] In some embodiments, the orthographic projection of the side surface of the color conversion portion near the second surface onto the second surface lies within the orthographic projection of the second through hole of the light blocking portion onto the second surface.

[0021] In some embodiments, the backlight module includes a color conversion section; the color conversion section is located on the side of the second surface away from the first surface.

[0022] In some embodiments, the backlight module includes a color conversion section located on the side of the protruding structure away from the second surface, and at least a portion of the color conversion section is located within the first groove.

[0023] In some embodiments, the orthographic projection of the first through-hole on the second surface lies within the orthographic projection of the first reflective layer on the second surface.

[0024] In some embodiments, in the direction from the first surface to the second surface, the distance between the side of the first through hole near the second surface and the surface of the first reflective layer away from the second surface is H2, the distance between the outer contour of the first through hole projected onto the second surface and the outer contour of the first reflective layer projected onto the second surface is X2, and the ratio of X2 to H2 is greater than 0.7.

[0025] In some embodiments, the backlight module includes a color conversion section located on the side of the protruding structure away from the second surface, wherein...

[0026] The distance between the side of the color conversion part near the second surface and the second surface is greater than or equal to the distance between the end of the first through hole near the second surface and the second surface;

[0027] Alternatively, the distance between the side of the color conversion part near the second surface and the second surface is less than the distance between the end of the first through hole near the second surface and the second surface; the first plane is perpendicular to the second surface and passes through the geometric center of the orthographic projection of the first through hole on the second surface; one point of the boundary of the first reflective layer on the side away from the second surface is the first boundary point; one point of the boundary of the first through hole on the side of the second surface is the third boundary point; the first boundary point and the third boundary point are located on the same side of the protruding structure; the straight line segment connecting the first boundary point and the third boundary point is the second boundary line; the outer contour of the part of the color conversion part on the first plane that exposes the first through hole and faces the first reflective layer is located on the second boundary line or on the side of the second boundary line near the protruding structure.

[0028] In some embodiments, the orthographic projection of the side of the color conversion portion near the second surface onto the second surface lies within the orthographic projection of the first through hole onto the second surface.

[0029] In some embodiments, the color conversion portion is located on the side of the second surface away from the first surface.

[0030] In some embodiments, the backlight module includes a light-blocking portion.

[0031] The light-blocking portion is not disposed between the first groove and the second reflective layer;

[0032] Alternatively, the light-blocking portion is disposed between the first groove and the second reflective layer, the first plane is perpendicular to the second surface and passes through the geometric center of the orthographic projection of the first through hole on the second surface, one of the boundary points of the cross section of the first reflective layer on the first plane away from the second surface is the first boundary point, one of the boundary points of the cross section of the first through hole on the first plane close to the second surface is the third boundary point, the first boundary point and the third boundary point are located on the same side of the protruding structure, the straight line segment connecting the first boundary point and the third boundary point is the second boundary line, and the light-blocking portion does not overlap with the second boundary line.

[0033] In some embodiments, the distance between the side of the color-converting portion near the second surface and the second surface is less than the distance between the end of the first through-hole near the second surface and the second surface. A first plane is perpendicular to the second surface and passes through the geometric center of the orthographic projection of the first through-hole onto the second surface. One point on the boundary of the first reflective layer's cross-section on the first plane near the second surface is a first boundary point. One point on the boundary of the first through-hole's cross-section on the first plane away from the second surface is a third boundary point. The first and third boundary points are located on the same side of the protruding structure. The straight line segment connecting the first and third boundary points is a second boundary line. The outer contour of the portion of the color-converting portion on the first plane that exposes the first through-hole and faces the first reflective layer overlaps with the second boundary line.

[0034] In the direction from the first surface to the second surface, the distance between the side of the color conversion part away from the second surface and the surface of the outer contour of the first reflective layer away from the second surface is H3, and the distance between the outer contour of the orthographic projection of the color conversion part on the second surface and the outer contour of the orthographic projection of the first reflective layer on the second surface is X3, and the ratio of X3 to H3 is greater than 0.7.

[0035] In some embodiments, the backlight module includes a light-blocking portion.

[0036] The light-blocking portion is not disposed between the first groove and the second reflective layer;

[0037] Alternatively, the light-blocking portion is disposed between the first groove and the second reflective layer, the first plane is perpendicular to the second surface and passes through the geometric center of the orthographic projection of the first through hole on the second surface, one of the boundary points of the cross section of the first reflective layer on the first plane away from the second surface is the first boundary point, one of the boundary points of the cross section of the color conversion portion on the first plane near the second surface is the fourth boundary point, the first boundary point and the fourth boundary point are located on the same side of the protruding structure, the straight line segment connecting the first boundary point and the fourth boundary point is the third boundary line, and the light-blocking portion does not overlap with the third boundary line.

[0038] In some embodiments, the backlight module further includes a first filling layer filled in the first groove, and the first filling layer is provided with a second groove;

[0039] The backlight module includes a light blocking portion, at least a portion of which is located within the second groove;

[0040] Alternatively, the backlight module includes a color conversion section, at least a portion of which is located within the second groove;

[0041] Alternatively, the backlight module includes a light blocking portion and a color conversion portion, with at least one of the light blocking portion and at least one of the color conversion portion located within the second groove.

[0042] In some embodiments, in the direction from the first surface to the second surface, the depth of the second groove is less than the minimum distance between the first reflective layer and the first surface.

[0043] In some embodiments, the backlight module includes a color conversion section, the surface of which is flush with the surface of the second reflective layer on the side away from the substrate.

[0044] In some embodiments, the backlight module includes a color conversion section, the orthographic projection of the color conversion section on the second surface coincides with the orthographic projection of the first through-hole of the second reflective layer on the second surface.

[0045] In some embodiments, the orthographic projection of the surface of the first reflective layer away from the second surface onto the second surface lies within the orthographic projection of the protruding structure onto the second surface.

[0046] In some embodiments, the backlight module includes a color conversion section, wherein the thickness of the color conversion section is greater than or equal to 20 μm in the direction from the first surface to the second surface.

[0047] In some embodiments, the side of the cross section of the protruding structure perpendicular to the second surface is curved;

[0048] Alternatively, the side of the cross-section of the protruding structure perpendicular to the second surface is straight.

[0049] In some embodiments, the slope of the side of the section of the protruding structure perpendicular to the second surface ranges from 0.35 to 0.85.

[0050] In some embodiments, the substrate and the protrusion structure are an integral structure;

[0051] Alternatively, the substrate and the protruding structure may be made of different materials.

[0052] In some embodiments, the distance between the point closest to the first reflective layer and the point farthest from the second surface in the direction parallel to the second surface is L1, and the distance between the point closest to the first reflective layer and the point farthest from the second surface in the direction perpendicular to the second surface is L2, and the ratio of L1 to L2 is less than 1.7.

[0053] In some embodiments, the backlight module further includes:

[0054] A conductive pad is located between the light-emitting device and the substrate, and the conductive pad is electrically connected to the light-emitting device; the orthographic projection of the conductive pad on the second surface is offset from the orthographic projection of the color conversion part on the second surface.

[0055] In some embodiments, the thickness of the conductive pad is less than or equal to 2 μm.

[0056] In some embodiments, the second reflective layer has a plurality of spaced light-collecting structures on the side near the substrate.

[0057] In some embodiments, the substrate includes a plurality of microstructures, wherein,

[0058] The light-collecting structure is a protrusion, and the microstructure is a first recessed structure, with each protrusion located within a corresponding first recessed structure; or...

[0059] The light-collecting structure is a recessed portion, and the microstructure is a first protruding structure, with each recessed portion covering the corresponding first protruding structure.

[0060] In some embodiments, the backlight module further includes an auxiliary layer disposed between the substrate and the second reflective layer, the auxiliary layer comprising a plurality of microstructures, wherein...

[0061] The light-collecting structure is a protrusion, and the microstructure is a second recessed structure, with each protrusion located within a corresponding second recessed structure; or...

[0062] The light-collecting structure is a recessed portion, and the microstructure is a second protruding structure, with each recessed portion covering the corresponding second protruding structure.

[0063] This application also provides a display device, including the aforementioned backlight module and a display panel located on the side of the substrate away from the light-emitting device.

[0064] The beneficial effects of this application include:

[0065] In this embodiment, a portion of the light emitted by the light-emitting device that enters the first groove of the substrate through the first through hole is reflected by the first reflective layer and then incident on the surface of the second reflective layer and is reflected. At least a portion of the light reflected by the second reflective layer is reflected multiple times between the second reflective layer and the second surface and then exits through the second surface of the substrate. This can improve the uniformity of the emitted light, and the backlight module may not have a uniform light film layer or the number of uniform light film layers may be reduced, which is beneficial to reducing the thickness of the backlight module.

[0066] In the light emitted by the light-emitting device, a portion of the light is not reflected by the first reflective layer. If this portion of the light passes through the area of ​​the first groove located on the periphery of the first reflective layer and is incident on the second surface of the substrate and emitted directly, it will cause the local brightness of the backlight module to be too high, resulting in poor brightness uniformity of the second surface.

[0067] When the backlight module of this embodiment includes a light-blocking portion, by providing the light-blocking portion, the inner wall of the second through-hole of the light-blocking portion can block at least a portion of the light that is not reflected by the first reflective layer from directly entering and exiting the second surface, which can improve or avoid the problem of excessive local brightness in the backlight module. At the same time, the orthographic projection of the second through-hole of the light-blocking portion on the second surface at least partially overlaps with the orthographic projection of the first reflective layer on the second surface, which can ensure that the light emitted through the second through-hole of the light-blocking portion is reflected as much as possible onto the surface of the first reflective layer, thereby improving the utilization rate of light.

[0068] In addition, when the backlight module of this embodiment includes a light blocking part, by placing the light blocking part on the side of the second reflective layer close to the second surface, the light blocking part can be avoided from occupying the space on the side of the second reflective layer away from the second surface. Furthermore, the overall thickness of the backlight module can be reduced by accommodating the light blocking part in the first groove.

[0069] Similarly, when the backlight module of this embodiment includes a color conversion section, the color conversion section is disposed on the side of the second reflective layer closer to the second surface, which can prevent the color conversion section from occupying the space on the side of the second reflective layer away from the second surface. The orthographic projection of the color conversion section on the second surface at least partially overlaps with the orthographic projection of the first through hole on the second surface; this allows the light emitted by the light-emitting device to undergo color conversion at the color conversion section after passing through the first through hole before being emitted.

[0070] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0071] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0072] Figure 1 shows a top view of part of the backlight module structure;

[0073] Figure 2 shows a sectional view taken along section line AA in Figure 1;

[0074] Figure 3 shows an enlarged view of point B in Figure 2;

[0075] Figures 4 to 20 show cross-sectional views of the backlight module provided in an exemplary embodiment of this application;

[0076] Figure 21 shows an enlarged view of point C in Figure 20;

[0077] Figures 22 to 29 show cross-sectional views of a backlight module provided in an exemplary embodiment of this application;

[0078] Figure 30 shows an enlarged view of point D in Figure 29;

[0079] Figures 31 and 32 show cross-sectional views of a backlight module provided in an exemplary embodiment of this application;

[0080] Figures 33 to 46 are schematic diagrams of the steps in the fabrication method of a backlight module provided in an exemplary embodiment of this application;

[0081] Figure 47 is a schematic diagram of the structure of a display device provided in an exemplary embodiment of this application.

[0082] In the figure: 10-substrate; 101-first surface; 102-second surface; 10a-first groove; 100-side surface of the first groove; 11-protruding structure; 111-side surface of the first groove; 20-first reflective layer; 30-second reflective layer; 30a-first through-hole; 31-light-collecting structure; 311-protrusion; 312-recess; 40-light-emitting device; 41-pin; 51-light-blocking part; 51a-second through-hole; 52-color conversion part; 61-first filling layer; 61a-second groove; 611-first sub-filling layer; 612-second sub-filling layer; 62-second filling layer; 71-conductive pad; 72-insulating layer; 80-third reflective layer; 90-auxiliary layer; 91 / 12-microstructure; 121-first recessed structure; 122-first protruding structure; 911 - Second recessed structure; 912 - Second raised structure; 92 - Mask layer; 921 - First mask portion; 921a - Mask through hole; 922 - Second mask portion; 10' - Original substrate; 200 - Display panel. Detailed Implementation

[0083] The present application will be described more fully below with reference to the accompanying drawings in which embodiments are illustrated.

[0084] It should be noted that when element A, such as a layer, film, or region, is referred to as "on the side of element B near element C," it means that element A can be directly on the surface of element B near element C, or an intermediate layer, intermediate region, or intermediate element may exist between element B and element C. When element A, such as a layer, film, or region, is referred to as "on the side of element B away from element C," it means that element A can be directly on the surface of element B away from element C, or an intermediate layer, intermediate region, or intermediate element may exist between element B and element A. When element A, such as a layer, film, or region, is referred to as "between element B and element C," it means that only element A exists between element B and element C, or an intermediate layer, intermediate region, or intermediate element may exist between element A and element B, or between element A and element C.

[0085] While terms such as "first," "second," etc., can be used to describe various components, such components are not limited by these terms. These terms are only used to distinguish one component from another and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more. Where there is no conflict, the features in the embodiments described below in this application may complement or combine with each other.

[0086] In the accompanying drawings, the symbols "x", "y", and "z" are used to indicate directions. The x, y, and z directions are not limited to three mutually perpendicular directions in a Cartesian coordinate system and can be interpreted in a broader sense. For example, the x, y, and z directions can be perpendicular to each other, or they can represent different directions that are not perpendicular to each other. Exemplarily, x indicates a first direction, y indicates a second direction perpendicular to the first direction, and z indicates a third direction perpendicular to both the first and second directions. The first direction x, the second direction y, and the third direction z can correspond to the horizontal, vertical, and thickness directions of the backlight module, respectively.

[0087] In the accompanying drawings, the dimensions and thicknesses of the elements may be enlarged for better understanding, clarity, and ease of description. However, this application is not limited to the dimensions and thicknesses shown in the drawings. The thicknesses of layers, films, panels, areas, and other elements may be exaggerated in the drawings for clarity. Example embodiments are shown in the drawings, wherein the same reference numerals denote the same elements.

[0088] As shown in Figures 1 and 2, Figure 1 is a top view of a portion of the backlight module structure. It should be noted that the light emission direction of the backlight module shown in Figure 1 is perpendicular to the paper and downwards. Figure 2 is a cross-sectional view taken along section line AA in Figure 1. The light emission direction of the backlight module shown in Figure 2 is the direction from the first surface 101 to the second surface 102. Figure 3 is an enlarged view of section B in Figure 2. Figures 4 to 20 are cross-sectional views of the backlight module provided in an exemplary embodiment of this application; Figure 21 is an enlarged view of section C in Figure 20; Figures 22 to 29 are cross-sectional views of the backlight module provided in an exemplary embodiment of this application; Figure 30 is an enlarged view of section D in Figure 29; Figures 31 and 32 are cross-sectional views of the backlight module provided in an exemplary embodiment of this application.

[0089] As shown in any of the figures 2 to 32, the backlight module includes a substrate 10, a protruding structure 11, a first reflective layer 20, a second reflective layer 30, and a light-emitting device 40. The substrate 10 includes a first surface 101 and a second surface 102 opposite to each other. The first surface 101 is provided with a first groove 10a. A protruding structure 11 is located in the first groove 10a and is spaced apart from the opening edge of the first groove 10a. In the direction from the first surface 101 to the second surface 102, the area of ​​the cross section of the protruding structure 11 parallel to the second surface 102 gradually increases. A first reflective layer 20 is located in the first groove 10a, at least covering the side surface of the protruding structure 11, and exposing at least a portion of the side surface of the first groove 10a. A second reflective layer 30 is located on the side of the substrate 10 away from the second surface 102. The second reflective layer 30 is provided with a first through hole 30a. The orthographic projection of the first through hole 30a on the second surface 102 of the substrate 10 overlaps with the orthographic projection of the first groove 10a on the second surface 102 of the substrate 10. A light-emitting device 40 and the second reflective layer 30 are located on the same side of the substrate 10. The light emitted by the light-emitting device 40 enters the first groove 10a through the first through hole 30a.

[0090] The backlight module further includes at least one of a light-blocking portion 51 and a color-conversion portion 52. Specifically, as shown in any of Figures 2 to 19, the light-blocking portion 51 is located on the side of the second reflective layer 30 near the second surface 102. The light-blocking portion 51 has a second through-hole 51a. The orthographic projection of the second through-hole 51a on the second surface 102 at least partially overlaps with the orthographic projection of the first through-hole 30a on the second surface 102, and the orthographic projection of the second through-hole 51a on the second surface 102 at least partially overlaps with the orthographic projection of the first reflective layer 20 on the second surface 102. As shown in any of Figures 20 to 32, the color-conversion portion 52 is located on the side of the second reflective layer 30 near the second surface 102. The orthographic projection of the color-conversion portion 52 on the second surface 102 at least partially overlaps with the orthographic projection of the first through-hole 30a on the second surface 102.

[0091] In this embodiment, among the light emitted by the light-emitting device 40 that enters the first groove 10a of the substrate 10 through the first through hole 30a, a portion of the light is reflected by the first reflective layer 20 and then incident on the surface of the second reflective layer 30 and is reflected. At least a portion of the light reflected by the second reflective layer 30 is reflected multiple times between the second reflective layer 30 and the second surface 102 and then exits through the second surface 102 of the substrate 10. This can improve the uniformity of the emitted light, and the backlight module may not have a uniform light film layer or the number of uniform light film layers may be reduced, which is beneficial to reducing the thickness of the backlight module.

[0092] In the light emitted by the light-emitting device 40, a portion of the light is not reflected by the first reflective layer 20. If this portion of the light passes through the area of ​​the first groove 10a located on the periphery of the first reflective layer 20 and is incident on the second surface 102 of the substrate 10 and emitted directly, it will cause the local brightness of the backlight module to be too high, which in turn will result in poor brightness uniformity of the second surface 102.

[0093] As shown in any of Figures 2 to 19, the backlight module of this embodiment includes a light blocking part 51. By providing the light blocking part 51, the second through hole 51a of the light blocking part 51 can limit the angle of light passing through it, reducing the amount of light that is not reflected by the first reflective layer 20 and directly enters the second surface 102 and exits, thus improving or avoiding the problem of excessive local brightness in the backlight module. At the same time, the orthographic projection of the second through hole 51a of the light blocking part 51 on the second surface 102 at least partially overlaps with the orthographic projection of the first reflective layer 20 on the second surface 102, which can ensure that the light emitted through the second through hole 51a of the light blocking part 51 is reflected as much as possible on the surface of the first reflective layer 20, improving the utilization rate of light.

[0094] In addition, by placing the light blocking part 51 on the side of the second reflective layer 30 close to the second surface 102, the light blocking part 51 can be prevented from occupying the space on the side of the second reflective layer 30 away from the second surface 102. Furthermore, the overall thickness of the backlight module can be reduced by accommodating the light blocking part 51 in the first groove 10a.

[0095] As shown in any of Figures 20 to 32, the backlight module of this embodiment includes a color conversion section 52. The color conversion section 52 is disposed on the side of the second reflective layer 30 closest to the second surface 102, thus avoiding the color conversion section 52 occupying the space on the side of the second reflective layer 30 furthest from the second surface 102. The orthographic projection of the color conversion section 52 on the second surface 102 at least partially overlaps with the orthographic projection of the first through-hole 30a on the second surface 102; this allows the light emitted by the light-emitting device 40 to undergo color conversion in the color conversion section 52 after passing through the first through-hole 30a before being emitted.

[0096] In some embodiments, the substrate 10 is used to support other components disposed thereon. The shape and size of the substrate 10 are adapted to the shape and size of the display device to which it is applied. Generally, the shape of the substrate 10 can be square, rectangular, etc. When applied to an irregularly shaped display device, the shape of the substrate 10 can also be circular or other irregular shapes, and there is no limitation herein. The substrate 10 can be made of transparent substrate materials commonly used in the display technology field, such as optical glass and optical plastics, and there is no limitation herein.

[0097] In some embodiments, the substrate 10 includes a first surface 101 and a second surface 102 opposite to each other. The first surface 101 is used to support other components in the backlight module, including a light-emitting device 40. The light emitted from the light-emitting device 40 is incident on the substrate 10 from the side where the first surface 101 is located. The second surface 102 serves as the light-emitting surface of the backlight module and can typically be a plane.

[0098] In some embodiments, the refractive index of the substrate 10 is greater than that of air. With this configuration, when light reflected by the second reflective layer 30 is incident on the second surface 102 of the substrate 10 at an angle greater than the critical angle for total internal reflection, it can undergo total internal reflection and re-enter the second reflective layer 30. This further improves the uniformity of the emitted light. In some embodiments, the material of the substrate 10 can be any one of glass, quartz, polymethyl methacrylate (PMMA), etc.

[0099] It should be noted that the critical angle for total internal reflection refers to the minimum angle of incidence at which total internal reflection occurs when light travels from a high-refractive-index medium to a low-refractive-index medium. It can be calculated using Snell's Law, specifically: θ = arcsin(n2 / n1). Here, θ is the critical angle for total internal reflection on the second surface 102, n1 is the refractive index of the medium the light passes through before reaching the second surface 102, and n2 is the refractive index of the medium the light enters after passing through the second surface 102. In this embodiment, the medium the light passes through before reaching the second surface 102 is the substrate 10, and the medium the light enters after passing through the second surface 102 is air. In one embodiment, when the substrate 10 is glass (refractive index 1.5), θ = arcsin(n2 / n1) = arcsin(1 / 1.5) ≈ 42°. That is, total internal reflection occurs when at least a portion of the incident light on the second surface 102 forms an angle α with the normal to the second surface 102 greater than 42°.

[0100] In this embodiment, the first groove 10a includes an inner surface with an opening edge, which is the outline of the end of the inner surface away from the second surface 102. As shown in FIG2, the inner surface includes a side surface 100 and a bottom surface. The side surface 100 is the inner surface extending from the opening edge of the first groove 10a to the lowest point of the first groove 10a. The lowest point of the first groove 10a is the point where the first groove 10a is closest to the second surface 102. The side surface 100 of the first groove 10a is opposite to the side surface 111 of the protruding structure 11. The side surface 111 of the protruding structure 11 is the portion extending from the highest point of the surface of the protruding structure 11 to the lowest point of the first groove 10a. The highest point of the surface of the protruding structure 11 is the point where the protruding structure 11 is farthest from the second surface 102.

[0101] In some embodiments, the protruding structure 11 and the opening edge of the first groove 10a are spaced apart, specifically, there is a gap between the side surface 100 of the protruding structure 11 and the side surface 111 of the first groove 10a.

[0102] In some embodiments, in the direction from the first surface 101 to the second surface 102, the area of ​​the cross section of the protruding structure 11 parallel to the second surface 102 gradually increases. Specifically, in the direction from the first surface 101 to the second surface 102, the side surface of the protruding structure 11 extends outward at an angle.

[0103] In some embodiments, in the direction from the first surface 101 to the second surface 102, the area of ​​the first groove 10a parallel to the cross section of the second surface 102 gradually decreases.

[0104] In some embodiments, the line connecting the geometric center of the protrusion 11 and the geometric center of the first groove 10a is perpendicular to the second surface 102 of the substrate 10. That is, the center of the orthographic projection of the protrusion 11 onto the second surface 102 of the substrate 10 coincides with the center of the orthographic projection of the first groove 10a onto the second surface 102 of the substrate 10.

[0105] In some embodiments, the outer contour of the orthographic projection of the protrusion 11 on the second surface 102 of the substrate 10 is circular, and the outer contour of the orthographic projection of the first groove 10a on the second surface 102 of the substrate 10 is circular; the center of the outer contour of the orthographic projection of the protrusion 11 on the second surface 102 of the substrate 10 coincides with the center of the outer contour of the orthographic projection of the first groove 10a on the second surface 102 of the substrate 10.

[0106] Furthermore, the protruding structure 11 includes a vertex, which is the point of the protruding structure 11 that is farthest from the second surface 102. The orthographic projection of the vertex of the protruding structure 11 onto the second surface 102 of the substrate 10 coincides with the center of the orthographic projection of the first groove 10a onto the second surface 102 of the substrate 10.

[0107] In some embodiments, the ratio of the radius of the outer contour of the orthographic projection of the protrusion 11 on the second surface 102 of the substrate 10 to the radius of the outer contour of the orthographic projection of the first groove 10a on the second surface 102 of the substrate 10 is less than 0.5.

[0108] In some embodiments, the material of the protrusion 11 is the same as or similar to the material of the substrate 10, which can improve the optical consistency between the substrate 10 and the protrusion 11.

[0109] In some embodiments, as shown in Figures 2 and 3, the protrusion structure 11 and the substrate 10 are integrally formed, and the protrusion structure 11 and the substrate 10 are made of the same material and can be fabricated in the same process. In another embodiment, as shown in Figure 4, the protrusion structure 11 and the substrate 10 are not integrally formed, and the material of the protrusion structure 11 is different from that of the substrate 10.

[0110] In some embodiments, as shown in FIG2, the first reflective layer 20 at least covers the side surface 111 of the protruding structure 11. In some embodiments, the first reflective layer 20 covers the entire area of ​​the side surface of the protruding structure 11. In other embodiments, as shown in FIG5, the first reflective layer 20 covers a portion of the side surface 111 of the protruding structure 11, with the remaining area of ​​the side surface of the protruding structure 11 exposed outside the first reflective layer 20. In other embodiments, the first reflective layer 20 covers the entire area of ​​the side surface of the protruding structure 11 and extends to cover a portion of the side surface of the first groove 10a (not shown in the figure).

[0111] In some embodiments, the longitudinal cross-sectional shape profile of the side surface of the protruding structure 11 may include a circular arc-like, a straight line-like, or a polygonal line-like shape. "Circular arc-like" means having a generally arc-shaped form, but is not limited to a standard arc. That is, "arc" here includes not only the shape of a basic arc, but also shapes resembling arcs. For example, some points in the longitudinal cross-sectional shape profile of the protruding structure 11 may not lie on the same circle as other points. "Straight line-like" means being generally straight, but is not limited to a standard straight line. That is, "straight line" here includes not only the shape of a basic straight line, but also shapes resembling straight lines. For example, some points in the longitudinal cross-sectional shape profile of the protruding structure 11 may not lie on the same straight line as other points. "Polylinear line-like" means being generally polygonal, but is not limited to a standard polygonal line. That is, "polylinear line" here includes not only the shape of a basic polygonal line, but also shapes resembling polygonal lines. For example, a segment in the longitudinal cross-sectional shape profile of the protruding structure 11 may be arc-shaped. "Longitudinal" refers to the direction perpendicular to the second surface 102 of the substrate 10.

[0112] In some embodiments, the side of the cross section of the protruding structure 11 perpendicular to the second surface 102 is curved. Preferably, as shown in FIG2, the side of the cross section of the protruding structure 11 perpendicular to the second surface 102 is recessed toward the second surface 102.

[0113] In other embodiments, as shown in FIG6, the side of the cross-section of the protruding structure 11 perpendicular to the second surface 102 is straight. In this embodiment, since the side is straight, that is, the protruding structure 11 is a tapered shape with a constant slope, compared to designing the side of the protruding structure 11 to be recessed towards the second surface 102, the side of the first reflective layer 20 covering the surface of the protruding structure 11 is straight, thus improving the uniformity of light emitted from the second surface 102.

[0114] Furthermore, the slope of the side of the cross-section perpendicular to the second surface 102 of the protruding structure 11 ranges from 0.35 to 0.85. With this configuration, light incident from the light-emitting device 40 through the first through-hole 30a onto the surface of the first reflective layer 20 can be reflected as much as possible to the surface of the second reflective layer 30, and then reflected a second time by the second reflective layer 30, thereby improving the uniformity of the emitted light. In some embodiments, the slope of the side of the cross-section perpendicular to the second surface 102 of the protruding structure 11 can be 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, or 0.85.

[0115] In some embodiments, the distance from the surface of the protruding structure 11 away from the second surface 102 to the second surface 102 is less than or equal to the distance from the first surface 101 to the second surface 102. In some examples, as shown in FIG2, the distance d1 from the surface of the protruding structure 11 away from the second surface 102 to the second surface 102 is less than the distance d2 from the first surface 101 to the second surface 102. This arrangement helps to reduce the distance between the light blocking portion 51 and the second surface 102, thereby reducing the overall thickness of the backlight module. In other examples, the distance from the surface of the protruding structure 11 away from the second surface 102 to the second surface 102 is equal to the distance from the first surface 101 to the second surface 102 (not shown in the figure).

[0116] In some embodiments, as shown in FIG4, the distance between the point closest to the first reflective layer 20 and the point farthest from the second surface 102 in a direction parallel to the second surface 102 is L1, and the distance between the point closest to the first reflective layer 20 and the point farthest from the second surface 102 in a direction perpendicular to the second surface 102 is L2, and the ratio of L1 to L2 is less than 1.7. In some examples, the ratio of L1 to L2 can be 1.69, 1.65, 1.5, 1.4, 1.2, 1, or 0.5.

[0117] In this embodiment, as the distance between the light blocking part 51 and the second surface 102 gradually decreases, the height of the vertex of the first reflective layer 20 also gradually decreases. This further leads to a smaller tilt angle of the first reflective layer 20, and the slope of the side of the cross-section perpendicular to the second surface 102 approaches 0. Consequently, the first reflective layer 20 cannot provide sufficient angle compensation for small-angle light rays incident on its surface. That is, light rays with small incident angles are reflected back into the first through-hole 30a upon impact with the surface of the first reflective layer 20, and thus cannot be reflected a second time by the first reflective layer 20 to the second reflective layer 30 before exiting onto the second surface 102. Therefore, the luminous flux of the light-emitting device 40 is reduced. Thus, experimental verification shows that by limiting the size of the first reflective layer 20, when the ratio of L1 to L2 is less than 1.7, the first reflective layer 20 exhibits better reflection effect on incident light. For example, when L1 is 150 μm and L2 is less than or equal to 88 μm, the reflection of the first reflective layer 20 is relatively small.

[0118] In some embodiments, the first reflective layer 20 includes a first metal film layer. The reflectivity of the first metal film layer is greater than or equal to 85%, and its material may include at least one of aluminum, silver, copper, and platinum. In other embodiments, the first reflective layer 20 further includes a first transparent metal oxide layer located on the side of the first metal film layer facing the substrate 10, and a second transparent metal oxide layer located on the side of the first metal film layer away from the substrate 10. The materials of the first and second transparent metal oxide layers may be indium tin oxide or indium zinc oxide, which can prevent the first metal film layer from being oxidized, thus reducing its reflectivity. In other embodiments, the material of the first reflective layer 20 may include white ink and / or silicone-based white adhesive.

[0119] In some embodiments, the thickness of the first reflective layer 20 is approximately 6000 angstroms.

[0120] In some embodiments, as shown in any of the figures 2 to 19, when the backlight module includes a light blocking portion 51, the projection center of the orthographic projection of the second through hole 51a of the light blocking portion 51 on the second surface 102 is substantially coincident with the projection center of the orthographic projection of the first reflective layer 20 on the second surface 102.

[0121] In some embodiments, as shown in any of the figures 20 to 32, when the backlight module includes a color conversion section 52, the projection center of the orthographic projection of the color conversion section 52 on the second surface 102 substantially coincides with the projection center of the orthographic projection of the first reflective layer 20 on the second surface 102.

[0122] In some embodiments, the second reflective layer 30 includes a second metal film layer. The reflectivity of the second metal film layer is greater than or equal to 85%, and its material may include at least one of aluminum, silver, copper, and platinum. In other embodiments, the second reflective layer 30 further includes a third transparent metal oxide layer located on the side of the second metal film layer facing the substrate 10, and a fourth transparent metal oxide layer located on the side of the second metal film layer away from the substrate 10. The materials of the third and fourth transparent metal oxide layers may be indium tin oxide or indium zinc oxide, which can prevent the second metal film layer from being oxidized, thus reducing its reflectivity. In other embodiments, the material of the second reflective layer 30 may include white ink and / or silicone-based white adhesive.

[0123] In some embodiments, the thickness of the second reflective layer 30 ranges from approximately 1500 angstroms.

[0124] In some embodiments, as shown in any of Figures 2 to 32, the second reflective layer 30 has a plurality of spaced-apart light-collecting structures 31 on the side near the substrate 10. The light-collecting structures 31 can disperse the light incident on the second reflective layer 30 to scatter it in various directions. Specifically, the light reflected by the second surface 102 is dispersed by the light-collecting structures 31 after being incident on the second reflective layer 30, changing the propagation direction of the light, and is then reflected by the second reflective layer 30 and emitted through the second surface 102 of the substrate 10, which can improve the brightness uniformity of the backlight module.

[0125] In one embodiment, the light-collecting structures 31 are uniformly distributed across the surface of the second reflective layer 30 facing the substrate 10, and the distance between the light-collecting structure 31 closest to the edge of the first groove 10a and the first groove 10a is less than or equal to 5 μm. This arrangement avoids a large distance between the light-collecting structure 31 and the first groove 10a, which would prevent light reflected by the second reflective layer 30 from reaching the light-collecting structure 31 in the area between the light-collecting structure 31 and the first groove 10a, thus preventing sufficient scattering of this portion of the light.

[0126] In one embodiment, the ratio of the maximum width to the height of the light-collecting structure 31 in the direction parallel to the second surface 102 ranges from 1.5 to 3.5. This configuration results in better light uniformity from the light-collecting structure 31. In some embodiments, the ratio is 1.5, 2, 2.5, 3, 3.5, etc.

[0127] In some embodiments, as exemplarily shown in FIG2, the substrate 10 includes a plurality of microstructures 12, the light-collecting structure 31 is a protrusion 311, the microstructure 12 is a first recessed structure 121, and each protrusion 311 is located in the corresponding first recessed structure 121.

[0128] In this embodiment, multiple spaced protrusions 311 combined with the second reflective layer 30 form an uneven surface, causing light irradiated onto the protrusions 311 and the surface of the second reflective layer 30 to be scattered, thereby dispersing in all directions and allowing the reflected light to exit uniformly through the second surface 102.

[0129] In some embodiments, exemplarily as shown in FIG7, the substrate 10 includes a plurality of microstructures 12, the light-collecting structure 31 being a recess 312, and the microstructure 12 being a first protrusion structure 122, with each recess 312 covering the corresponding first protrusion structure 122. In the embodiment shown in FIG7, the first protrusion structure 122 is formed on the first surface 101 of the substrate 10.

[0130] In another embodiment, as shown in FIG8, the backlight module further includes an auxiliary layer 90, which is disposed between the substrate 10 and the second reflective layer 30. The auxiliary layer 90 includes a plurality of microstructures 91, the light-collecting structure 31 being a protrusion 311, and the microstructure being a second recessed structure 911, with each protrusion 311 located within a corresponding second recessed structure 911. In some other embodiments, as shown in FIG9, the backlight module further includes an auxiliary layer 90, which includes a plurality of microstructures 91, the light-collecting structure 31 being a recessed portion 312, and the microstructure 91 being a second protrusion 912, with each recessed portion 312 covering a corresponding second protrusion 912.

[0131] In this embodiment, after the auxiliary layer 90 is added, the area covered by the auxiliary layer 90 in the first groove 10a is correspondingly provided with microstructures 91, thus increasing the area of ​​the microstructures 91 and improving the light uniformity effect.

[0132] In some embodiments, as shown in FIG8 or FIG9, at least a portion of the microstructure 91 is projected onto the second surface 102 in the orthogonal projection of the first groove 10a onto the second surface 102.

[0133] In some embodiments, the auxiliary layer 90 may be made of a transparent resin material.

[0134] In some embodiments, the thickness of the auxiliary layer 90 is approximately 1500 angstroms.

[0135] In some embodiments, the maximum size of the cross-section of the microstructure 91 / 12 parallel to the second surface 102 of the substrate 10 ranges from 5 μm to 50 μm. This configuration allows for better light uniformity in the formed light-collecting structure 31, and the microstructure is easy to fabricate. In some embodiments, the maximum size of the cross-section of the microstructure 91 / 12 parallel to the surface of the substrate 10 is 5 μm, 15 μm, 25 μm, 35 μm, 45 μm, 50 μm, etc.

[0136] In some embodiments, when the light-collecting structure 31 is a protrusion 311, the material of the light-collecting structure 31 is a reflective material or a scattering material. In some examples, the material of the light-collecting structure 31 is a metal, preferably, the material of the light-collecting structure 31 includes at least one of aluminum, silver, copper, and platinum. In other examples, the material of the light-collecting structure 31 includes a substrate and scattering particles coated on the substrate. The substrate may include at least one of polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), and epoxy resin. The scattering particles may include at least one of titanium dioxide (TiO2), alumina (Al2O3), silicon dioxide (SiO2), polystyrene microspheres, and metal nanoparticles.

[0137] In some embodiments, when the light-collecting structure 31 is a recess 312, the material of the light-collecting structure 31 is a reflective material. In some examples, the material of the light-collecting structure 31 is a metal, preferably, the material of the light-collecting structure 31 includes at least one of aluminum, silver, copper and platinum.

[0138] In some embodiments, the first reflective layer 20 and the light-collecting structure 31 are made of the same material. Preferably, the first reflective layer 20 and the light-collecting structure 31 are an integral structure.

[0139] In some embodiments, the shape of the protrusion 311 or the recess 312 may be approximately one of a cone, a pyramid, or a spherical cap. "Approximately cone and pyramid" means that it is generally conical or pyramidal, but is not limited to standard cones and pyramids. That is, "conical and pyramidal" here includes not only the shapes of basic cones and pyramids, but also shapes similar to cones and pyramids. For example, the apex of a cone or pyramid is a curved surface. "Approximately spherical cap" means that it is generally spherical cap, but is not limited to a standard spherical cap. That is, "spherical cap" here includes not only the shape of a basic spherical cap, but also shapes similar to spherical caps. For example, the upper half of a spherical cap is a standard spherical cap, and the lower half is a cylinder.

[0140] In some embodiments, the light-emitting device 40 includes at least one light-emitting element, which may include a Micro LED and / or a Mini LED. The size (e.g., length) of the Micro LED is less than 50 micrometers, for example, 10 micrometers to 50 micrometers. The size (e.g., length) of the Mini LED is 50 micrometers to 150 micrometers, for example, 80 micrometers to 120 micrometers. When the light-emitting device 40 includes two or more light-emitting elements, the light-emitting elements of the same light-emitting device 40 may be connected in series.

[0141] In some embodiments, the light-emitting device 40 and the second reflective layer 30 are located on the same side of the substrate 10. Specifically, the light-emitting device 40 is located on the side of the second reflective layer 30 away from the substrate 10. Alternatively, the light-emitting device 40 is located on the side of the second reflective layer 30 close to the substrate 10. Alternatively, a portion of the light-emitting device 40 is located on the side of the second reflective layer 30 close to the substrate 10, and another portion is disposed in the same layer as the second reflective layer 30 or on the side of the second reflective layer 30 away from the substrate 10. Alternatively, a portion of the light-emitting device 40 is located on the side of the second reflective layer 30 away from the substrate 10, and another portion is disposed in the same layer as the second reflective layer 30 or on the side of the second reflective layer 30 close to the substrate 10. Preferably, as shown in any of Figures 2 to 32, the light-emitting device 40 is located on the side of the second reflective layer 30 away from the substrate 10. This allows the light reflected by the first reflective layer 20 to be reflected twice by the second reflective layer 30 as much as possible, thereby improving the uniformity of the emitted light.

[0142] In some embodiments, as shown in any of Figures 2 to 32, the backlight module further includes a plurality of conductive pads 71 ​​disposed on the side of the first reflective layer 20 away from the substrate 10. Each light-emitting element includes at least two pins 41, and each pin 41 is connected to a conductive pad 71. The backlight module may also include signal lines (not shown) disposed on the same layer as the conductive pads 71.

[0143] In some embodiments, the conductive pad 71 is located between the light-emitting device 40 and the substrate 10, and the conductive pad 71 is electrically connected to the light-emitting device 40; the orthographic projection of the conductive pad 71 on the second surface 102 and the orthographic projection of the color conversion part 52 on the second surface 102 are offset from each other. Specifically, the orthographic projection of the conductive pad 71 on the second surface 102 and the orthographic projection of the color conversion part 52 on the second surface 102 do not overlap or partially overlap.

[0144] In some embodiments, the thickness of the conductive pad 71 may be less than or equal to 2 μm.

[0145] In some embodiments, as shown in any of the figures 2 to 32, the backlight module further includes an insulating layer 72, which is located between the first reflective layer 20 and the conductive pad 71. When the first reflective layer 20 is made of a metal material, the insulating layer 72 can be used to prevent the formation of an electrical connection between the conductive pad 71 and the first reflective layer 20, which could lead to a short circuit between different conductive pads 71.

[0146] In some embodiments, the insulating layer 72 can be a single-layer structure or a multi-layer structure, for example, it can be a single-layer organic film or inorganic film, or it can be formed by alternating layers of organic film and inorganic film.

[0147] In some embodiments, as shown in any of Figures 2 to 32, the backlight module further includes a third reflective layer 80, which covers the light-emitting element, and has a light-emitting aperture on the side of the third reflective layer 80 facing the substrate 10. The orthographic projection of the light-emitting area of ​​the light-emitting element onto the second surface 102 of the substrate 10 falls within the orthographic projection of a light-emitting aperture onto the second surface 102 of the substrate 10. The third reflective layer 80 can reflect light emitted from the non-light-emitting area of ​​the light-emitting element, thereby improving light utilization. The third reflective layer 80 can cover the surface of the light-emitting element away from the substrate 10, the side surface of the light-emitting element, and the portion of the surface of the light-emitting element close to the substrate 10.

[0148] In one embodiment, as shown in any of Figures 2 to 32, the material of the third reflective layer 80 includes at least one of white ink and silicone-based white adhesive. For example, the material of the third reflective layer 80 may be white ink or silicone-based white adhesive.

[0149] In some embodiments, as shown in any of Figures 2 to 32, the backlight module further includes a first filling layer 61 filled within the first groove 10a. The first filling layer 61 is made of a transparent organic material, and its transmittance is greater than or equal to 95%.

[0150] In some embodiments, as shown in any of Figures 2 to 32, the backlight module further includes a second filling layer 62 filled between the light-emitting device 40 and the first groove 10a. The material of the second filling layer 62 includes a transparent organic material, and the transmittance of the second filling layer 62 can be greater than or equal to 95%. This configuration can improve the transmittance of light passing through the second filling layer 62 into the first through-hole 30a, while also increasing the support force of the light-transmitting substrate on the light-emitting device 40, thereby improving the overall structural strength of the backlight module. Simultaneously, it can alleviate the problem of stress generated between the materials due to the mismatch of the thermal expansion coefficients of the light-emitting device 40 and the light-transmitting substrate when the temperature changes, which could lead to separation or damage of the light-emitting device 40 from the light-transmitting substrate. The second filling layer 62 can effectively disperse stress and prevent damage to the light-emitting device 40.

[0151] In some embodiments, the first filling layer 61 and the second filling layer 62 are made of the same material.

[0152] In some embodiments, the refractive index of the first filling layer 61 is the same as that of the substrate 10. In some embodiments, the refractive indices of both the substrate 10 and the first filling layer 61 are 1.5.

[0153] In some embodiments, the refractive index of the second filling layer 62 is the same as that of the substrate 10. In some embodiments, the refractive indices of both the substrate 10 and the second filling layer 62 are 1.5.

[0154] In some embodiments, the first filling layer 61 is provided with a second groove 61a.

[0155] In some embodiments, the backlight module includes a light blocking portion 51, as shown in any one of Figures 2 to 9 and Figures 10 to 19, where at least a portion of the light blocking portion 51 is located within a second groove 61a.

[0156] In some embodiments, the backlight module includes a color conversion section 52, as shown in any one of Figures 22-25 and 29-30, at least a portion of which is located within a second groove 61a.

[0157] In some embodiments, the backlight module includes a light-blocking portion 51 and a color-converting portion 52, as shown in Figures 2-9 and any one of Figures 11-18, 22-25, and 29-30. At least one of the light-blocking portion 51 and at least one of the color-converting portion 52 is located within a second groove 61a. This embodiment, by providing a second groove 61a to accommodate the light-blocking portion 51 or the color-converting portion 52, eliminates the need for a separate area to house the light-blocking portion 51 or the color-converting portion 52, thus reducing the overall thickness of the backlight module.

[0158] In some embodiments, the depth of the second groove 61a is less than the depth of the first groove 10a.

[0159] In some embodiments, the surface of the second groove 61a near the second surface 102 is flush with the surface of the first reflective layer 20 away from the second surface 102. Further, the backlight module includes a color conversion section 52, and when the color conversion section 52 is located within the second groove 61a, the surface of the color conversion section 52 away from the substrate 10 is flush with the surface of the second reflective layer 30 away from the substrate 10.

[0160] In other embodiments, the second groove 61a has a gap between the side surface of the second groove 61a near the second surface 102 and the side surface of the first reflective layer 20 away from the second surface 102 in the direction from the first surface 101 to the second surface 102. That is, in the direction from the first surface 101 to the second surface 102, the depth of the second groove 61a is less than the minimum gap between the first reflective layer 20 and the first surface 101.

[0161] In some embodiments, the light emitted by the light-emitting device 40 is blue light, as shown in any of Figures 20 to 32, where the backlight module includes a color conversion section 52 but does not include a light blocking section 51; or, as shown in any of Figures 2 to 12 and Figures 14 to 19, the backlight module includes both a color conversion section 52 and a light blocking section 51, where the color conversion section 52 can convert blue light into white light. In other embodiments, as shown in Figure 13, the backlight module may include only the light blocking section 51, and the light emitted by the light-emitting device 40 is white light.

[0162] In some embodiments, the backlight module includes a light-blocking portion 51, which is made of a light-absorbing material. In some examples, the light-blocking portion 51 is made of black resin, composed of a polymer containing a black pigment (such as carbon black). The thickness of the light-blocking portion 51 is approximately 20 μm to 30 μm. In some examples, the thickness of the light-blocking portion 51 is 20 μm, 25 μm, or 30 μm.

[0163] In some embodiments, as shown in FIG2, the backlight module includes a light-blocking portion 51, at least a portion of which is located within a first groove 10a. The space within the first groove 10a can then be used to accommodate at least a portion of the light-blocking portion 51, thereby reducing the overall thickness of the backlight module. Preferably, the entire light-blocking portion 51 is located within the first groove 10a.

[0164] In some embodiments, as shown in FIG2, the backlight module includes a light blocking portion 51. The outer contour of the orthographic projection of the light blocking portion 51 on the second surface 102 is located inside the edge of the orthographic projection of the first groove 10a on the second surface 102. With this configuration, light incident on the surface of the first reflective layer 20, after being reflected by the first reflective layer 20, can travel from the area of ​​the first groove 10a not covered by the light blocking portion 51 to the surface of the second reflective layer 30. This minimizes the absorption of the light reflected by the first reflective layer 20 by the light blocking portion 51, thereby improving light utilization.

[0165] In some embodiments, as shown in FIG2, the backlight module includes a light blocking portion 51, and the orthographic projection of the first through-hole 30a of the second reflective layer 30 on the second surface 102 is located within the orthographic projection of the second through-hole 51a of the light blocking portion 51 on the second surface 102. This arrangement prevents the light emitted by the light-emitting device 40 from being directly absorbed by the light blocking portion 51 and failing to escape, thus preventing a reduction in light utilization. In some examples, as shown in FIG2, the orthographic projection of the first through-hole 30a of the second reflective layer 30 on the second surface 102 completely coincides with the orthographic projection of the second through-hole 51a of the light blocking portion 51 on the second surface 102. In other examples, as shown in FIG12, the outer contour of the orthographic projection of the first through-hole 30a of the second reflective layer 30 on the second surface 102 is located inside the edge of the orthographic projection of the second through-hole 51a of the light blocking portion 51 on the second surface 102.

[0166] In some embodiments, as shown in FIG2, the backlight module includes a light blocking portion 51. The orthographic projection of the second through-hole 51a of the light blocking portion 51 onto the second surface 102 is located within the orthographic projection of the first reflective layer 20 onto the second surface 102. The light blocking portion 51 can limit the range of the emission angle of the light emitted through the second through-hole 51a. Furthermore, it can ensure that the incident angle of the light directly entering the second surface 102 among the light emitted through the second through-hole 51a is as large as possible greater than the critical angle of total internal reflection. This part of the light can undergo total internal reflection on the second surface 102 and be reflected to the second reflective layer 30. After multiple reflections between the second reflective layer 30 and the second surface 102, it can enter the second surface 102 again, instead of emitting directly from the second surface 102. This can improve the uniformity of the emitted light.

[0167] In some embodiments, as shown in any one of Figures 2 to 19, in the direction from the first surface 101 to the second surface 102, the distance between the side of the second through hole 51a near the second surface 102 and the surface of the first reflective layer 20 away from the second surface 102 is H1, and the distance between the outer contour of the second through hole 51a projected onto the second surface 102 and the outer contour of the first reflective layer 20 projected onto the second surface 102 is X1, and the ratio of X1 to H1 is greater than 0.7.

[0168] In this embodiment, by setting the ratio of X1 to H1 to be greater than 0.7, most incident light rays with an incident angle less than or equal to the critical angle of total internal reflection are blocked by the light blocking part 51, thereby preventing these light rays from directly escaping after entering the second surface 102. This effectively improves the problem of excessive brightness in some areas of the backlight module. Specifically, the critical angle of total internal reflection θ of the second surface 102 is determined by the material of the structure before and after the light passes through the second surface 102. When X1 > H1 × tanθ = H1 × tan[arcsin(n2 / n1)], where n1 is the refractive index of the medium through which the light passes before reaching the second surface 102, and n2 is the refractive index of the medium into which the light enters after passing through the second surface 102, it can be ensured that all light rays with an incident angle less than θ are blocked by the light blocking part 51. Typically, the critical angle of total internal reflection θ of the second surface 102 of the substrate 10 is in the range of 35° to 55°. When θ is 35°, X1 > H1 × tan35° = 0.7H1. Setting X1 > 0.7H1 ensures that most light rays with an incident angle less than θ are blocked by the light blocking part 51. In one embodiment, the substrate 10 is made of glass with a refractive index n1 of 1.5, and the medium into which the light enters after passing through the second surface 102 is air with a refractive index n2 of 1. In this case, X1 > H1 × tan42° = 0.9H1 can be set.

[0169] Under the premise of satisfying the above relationship, the backlight module further includes a color conversion part 52; the color conversion part 52 is located on the side of the protruding structure 11 away from the second surface 102, and the light blocking part 51 is disposed around the color conversion part 52.

[0170] When the color conversion part 52 is located on the side of the protruding structure 11 away from the second surface 102, specifically including the following two situations:

[0171] In the first scenario, the distance between the side of the color conversion part 52 closest to the second surface 102 and the second surface 102 is greater than or equal to the distance between the end of the second through hole 51a closest to the second surface 102 and the second surface 102. In some examples, as shown in FIG2, the distance between the side of the color conversion part 52 closest to the second surface 102 and the second surface 102 is equal to the distance between the end of the second through hole 51a closest to the second surface 102 and the second surface 102. In other examples, as shown in FIG14, the distance d3 between the side of the color conversion part 52 closest to the second surface 102 and the second surface 102 is greater than the distance d4 between the end of the second through hole 51a closest to the second surface 102 and the second surface 102.

[0172] The second scenario: As shown in any of Figures 16 to 18, the distance between the side of the color conversion part 52 closest to the second surface 102 and the second surface 102 is less than the distance between the end of the second through hole 51a closest to the second surface 102 and the second surface 102. The first plane (i.e., the paper surface) is perpendicular to the second surface 102 and passes through the geometric center of the orthographic projection of the second through hole 51a onto the second surface 102. Specifically, referring to Figure 3, one of the points on the boundary of the first reflective layer 20's cross-section on the first plane away from the second surface 102 is the first boundary point e1 (e2). The second through hole... One of the points on the boundary of the cross section of 51a on the first plane near the side of the second surface 102 is the second boundary point f1 (f2). The first boundary point e1 (e2) and the second boundary point f1 (f2) are located on the same side of the cross section of the protruding structure 11 on the first plane. The straight line segment connecting the first boundary point and the second boundary point is the first boundary line m1 (m2). The outer contour of the part of the color conversion part 52 that exposes the second through hole 51a on the cross section of the first plane and faces the first reflective layer 20 is located on the first boundary line m1 (m2) or the first boundary line m1 (m2) is near the side of the protruding structure 11.

[0173] In this embodiment, the color conversion section 52 does not affect the light emission angle. In some examples, as shown in FIG16 or FIG17, the outer contour of the portion of the color conversion section 52 exposing the second through-hole 51a on the first plane and facing the first reflective layer 20 is located on the side of the first boundary line closer to the protruding structure 11. In other examples, as shown in FIG18, the outer contour of the portion of the color conversion section 52 exposing the second through-hole 51a on the first plane and facing the first reflective layer 20 is at least partially located on the first boundary line.

[0174] Building upon the second scenario, further in some embodiments, as shown in FIG16, the orthographic projection of the side surface of the color conversion section 52 near the second surface 102 on the second surface 102 lies within the orthographic projection of the second through-hole 51a of the light-blocking section 51 on the second surface 102. In this case, the fabrication process can be further simplified by using the light-blocking section 51 as a mask material to create the groove for forming the color conversion section 52. In other embodiments, as shown in FIG17 or FIG18, the orthographic projection of the side surface of the color conversion section 52 near the second surface 102 on the second surface 102 covers the orthographic projection of the second through-hole 51a of the light-blocking section 51 on the second surface 102, and the projected area of ​​the orthographic projection of the side surface of the color conversion section 52 near the second surface 102 on the second surface 102 is larger than the projected area of ​​the orthographic projection of the second through-hole 51a of the light-blocking section 51 on the second surface 102. In this case, the color conversion section 52 occupies a larger volume, thereby improving color conversion efficiency and luminous flux.

[0175] Furthermore, referring to Figure 3, the dimension of the end of the second through hole 51a of the light blocking portion 51 near the second surface 102 in the direction parallel to the second surface 102 can vary with the distance between the light blocking portion 51 and the second surface 102. Specifically, as the distance between the side surface of the light blocking portion 51 near the second surface 102 and the second surface 102 decreases, the dimension of the end of the second through hole 51a of the light blocking portion 51 near the second surface 102 gradually increases in the direction parallel to the second surface 102. In one example, the two points on the edge of the cross-section perpendicular to the second surface 102 at the end of the second through hole 51a of the light blocking portion 51 near the second surface 102 are located on the two first boundary lines m1 and m2 shown in any of the figures in Figures 2 to 14. As shown in Figure 3, the first boundary line m1 is the line connecting the first boundary point e1 on the same side of the surface of the first reflective layer 20 away from the second surface 102 on the same cross section, and the second boundary point f1 on the end of the second through hole 51a of the light blocking part 51 near the second surface 102 on the cross section perpendicular to the second surface 102. The first boundary line m2 is the line connecting the first boundary point e2 on the surface of the first reflective layer 20 away from the second surface 102, and the second boundary point f2 on the end of the second through hole 51a of the light blocking part 51 near the second surface 102 on the cross section perpendicular to the second surface 102. The emission angles of the light rays coinciding with the first boundary lines m1 and m2 are angles θ1 and θ2, respectively.

[0176] It should be noted that the angles θ1 and θ2 can be the total internal reflection angles of the second surface 102; θ1 and θ2 can be the same or different. In some embodiments, the value of θ1 can be 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, or 55°. The value of θ2 can be 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, or 55°. In one example, the substrate material is glass, and θ1 and θ2 are both 42°; the same applies to the following embodiments.

[0177] In some embodiments, in the direction from the first surface 101 to the second surface 102, the distance between the first boundary point e1 and the second surface 102 may be the same as or different from the distance between the second boundary point e2 and the second surface 102. In one example, the distance between the first boundary point e1 and the second surface 102 is the same as the distance between the second boundary point e2 and the second surface 102, and the same applies to the following embodiments.

[0178] In some embodiments, as shown in FIG2, the backlight module includes both a light-blocking portion 51 and a color-converting portion 52. Both the light-blocking portion 51 and the color-converting portion 52 are located on the side of the protruding structure 11 away from the second surface 102. The side surface of the color-converting portion 52 closest to the second surface 102 is located within the second through-hole 51a. This arrangement results in a smaller space occupied by the color-converting portion 52 within the first groove 10a, facilitating the placement of the protruding structure 11 within the first groove. In some examples, as shown in FIG2, the side surface of the color-converting portion 52 closest to the second surface 102 is flush with the portion of the side surface of the light-blocking portion 51 closest to the second surface 102 that does not cover the second through-hole 51a. In other examples, as shown in FIG14, the side surface of the color-converting portion 52 closest to the second surface 102 is flush with the portion of the side surface of the light-blocking portion 51 away from the second surface 102 that does not cover the second through-hole 51a.

[0179] In this embodiment, since the distance between the light blocking part 51 and the first reflective layer 20 is closer than the distance between the second reflective layer 30 and the first reflective layer 20, that is, the distance between the second through hole 51a and the first reflective layer 20 is smaller than the distance between the first through hole 30a and the first reflective layer 20, when the same light rays pass through the edge of the second through hole 51a near the second surface 102 and the edge of the first through hole 30a near the second surface 102 in sequence, the second through hole 51a is larger than the first through hole 30a. Since the color conversion part 52 is located inside the second through hole 51a, the portion of the color conversion part 52 located inside the second through hole 51a can be designed to have a larger cross-section parallel to the second surface 102, thereby increasing the volume of the color conversion part 52 or the surface area of ​​the color conversion part 52 near the second surface 102, so as to improve the efficiency of color conversion or increase the light flux.

[0180] Under the premise of satisfying the aforementioned relationship between X1 and H1, further, in some embodiments, as shown in FIG19, the backlight module includes both a light blocking part 51 and a color conversion part 52. The light blocking part 51 is located on the side of the protruding structure 11 away from the second surface 102, and the color conversion part 52 is located on the side of the second surface 102 away from the protruding structure 11. In this way, the color conversion part 52 does not occupy the space between the first reflective layer 20 and the second reflective layer 30, that is, the color conversion part 52 does not occupy the space in the first groove 10a, so the protruding structure 11 can be set higher. In the manufacturing process, as the etching depth increases, the height of the protruding structure 11 gradually decreases; a larger height of the protruding structure 11 can reduce the etching depth of the first groove 10a, thus reducing the depth of the first groove 10a. This arrangement is beneficial for reducing the thickness of the substrate 10. Furthermore, the orthogonal projection of the color conversion part 52 on the second surface 102 covers the second surface 102. This arrangement allows all light colors to be converted before emission.

[0181] In some embodiments, as shown in FIG2 or FIG15-18, the backlight module includes a light-blocking portion 51 and a color-converting portion 52. At least a portion of the color-converting portion 52 is located within a first groove 10a. Compared to placing the color-converting portion 52 on the side of the second reflective layer 30 away from the first groove 10a, the overall thickness of the backlight module can be reduced. In some examples, as shown in FIG2 or 15, the color-converting portion 52 is located within the first groove 10a, and there is a gap between the color-converting portion and the first reflective layer 20. In other examples, as shown in any of FIG16-18, the color-converting portion 52 is located within the first groove 10a, and the color-converting portion is in contact with the first reflective layer 20.

[0182] In some embodiments, as shown in FIG14, when the backlight module includes a light blocking portion 51 and a color conversion portion 52, the color conversion portion 52 is not disposed within the first groove 10a. This avoids the color conversion portion 52 occupying space within the first groove 10a. More space is available within the first groove 10a to accommodate the protruding structure 11 and the first reflective layer 20.

[0183] In some embodiments, the material of the color conversion part 52 is a fluorescent material. Since the fluorescent material has good water and oxygen resistance, the backlight module does not need to be provided with an encapsulation layer for encapsulating the color conversion part 52, which can further reduce the thickness of the backlight module and reduce the manufacturing cost of the backlight module.

[0184] In some embodiments, the thickness of the color conversion portion 52 is greater than or equal to 20 μm, approximately 20 μm to 30 μm, in the direction from the first surface 101 to the second surface 102. In some examples, the thickness of the color conversion portion 52 is 20 μm, 25 μm, or 30 μm.

[0185] In some embodiments, the backlight module includes a color conversion section 52 located on the side of the protruding structure 11 away from the second surface 102, with at least a portion of the color conversion section 52 located within the first groove 10a. This configuration reduces the overall thickness of the backlight module.

[0186] In some embodiments, as shown in Figures 20-32, the orthographic projection of the first through-hole 30a on the second surface 102 lies within the orthographic projection of the first reflective layer 20 on the second surface 102. Furthermore, the first through-hole 30a can define the range of light emission angles.

[0187] In some embodiments, as shown in any of Figures 20 to 32, in the direction from the first surface 101 to the second surface 102, the distance between the side of the first through hole 30a near the second surface 102 and the surface of the first reflective layer 20 away from the second surface 102 is H2, and the distance between the outer contour of the first through hole 30a projected onto the second surface 102 and the outer contour of the first reflective layer 20 projected onto the second surface 102 is X2, and the ratio of X2 to H2 is greater than 0.7.

[0188] This embodiment allows most incident light rays with an incident angle less than or equal to the critical angle of total internal reflection to be restricted from exiting by the first through-hole 30a, thereby preventing these light rays from entering the second surface 102 and exiting directly, which can effectively improve the problem of excessive brightness in some areas of the backlight module.

[0189] While satisfying the aforementioned relationship between X2 and H2, in some embodiments, the backlight module further includes a color conversion section 52; the color conversion section 52 is located on the side of the protruding structure 11 away from the second surface 102.

[0190] When the color conversion part 52 is located on the side of the protruding structure 11 away from the second surface 102, specifically including the following two situations:

[0191] In the first scenario, the distance between the side of the color conversion part 52 closest to the second surface 102 and the second surface 102 is greater than or equal to the distance between the end of the first through hole 30a closest to the second surface 102 and the second surface 102. In some examples, as shown in FIG20, the distance between the side of the color conversion part 52 closest to the second surface 102 and the second surface 102 is equal to the distance between the end of the first through hole 30a closest to the second surface 102 and the second surface 102. In other examples, the distance between the side of the color conversion part 52 closest to the second surface 102 and the second surface 102 is greater than the distance between the end of the first through hole 30a closest to the second surface 102 and the second surface 102 (not shown in the figure).

[0192] The second scenario: As shown in any of Figures 22 to 25, the distance between the side of the color conversion part 52 near the second surface 102 and the second surface 102 is less than the distance between the end of the first through hole 30a near the second surface 102 and the second surface 102. The first plane is perpendicular to the second surface 102 and passes through the geometric center of the orthographic projection of the first through hole 30a onto the second surface 102. Specifically, referring to Figure 21, one of the points on the boundary of the first reflective layer 20's cross-section on the first plane away from the second surface 102 is the first boundary point e1 (e2). The first through hole 30a is located at... One of the points on the boundary of the cross section on the first plane near the side of the second surface 102 is the third boundary point g1 (g2). The first boundary point e1 (e2) and the third boundary point g1 (g2) are located on the same side of the protruding structure 11. The straight line segment connecting the first boundary point e1 (e2) and the third boundary point g1 (g2) is the second boundary line p1 (p2). The outer contour of the part of the color conversion part 52 that exposes the first through hole 30a on the cross section of the first plane and faces the first reflective layer 20 is located on the second boundary line p1 (p2) or the second boundary line p1 (p2) is near the side of the protruding structure 11.

[0193] In this embodiment, the same principle applies as when the light blocking part 51 surrounds the color conversion part 52 in the previous embodiment, and will not be repeated here.

[0194] In some embodiments, as shown in FIG22, the orthographic projection of the side surface of the color conversion part 52 near the second surface 102 on the second surface 102 is located within the orthographic projection of the first through hole 30a on the second surface 102.

[0195] While satisfying the aforementioned relationship between X2 and H2, in some embodiments, as shown in FIG26, the color conversion part 52 is located on the side of the second surface 102 away from the first surface 101.

[0196] Specifically, referring to Figure 21, the dimension of the side of the first through-hole 30a near the second surface 102 in the direction parallel to the second surface 102 can vary with the distance between the second reflective layer 30 and the second surface 102. Specifically, as the distance between the side of the second reflective layer 30 near the second surface 102 and the second surface 102 decreases, the dimension of the side of the first through-hole 30a near the second surface 102 in the direction parallel to the second surface 102 gradually increases. In one example, the two points on the edge of the cross-section perpendicular to the second surface 102 at the end of the first through-hole 30a near the second surface 102 are located on the two second boundary lines p1 and p2 shown in any of the figures in Figures 2 to 14. As shown in Figure 3, the second boundary line p1 is the line connecting the first boundary point e1 on the same side of the first reflective layer 20 away from the second surface 102 on the same cross section, and the third boundary point g1 of the first through hole 30a near the second surface 102 on the cross section perpendicular to the second surface 102. The second boundary line p2 is the line connecting the first boundary point e2 on the first reflective layer 20 away from the second surface 102, and the third boundary point g2 of the first through hole 30a near the second surface 102 on the cross section perpendicular to the second surface 102. The exit angles of the light rays coinciding with the second boundary lines p1 and p2 are angles θ1 and θ2, respectively.

[0197] When the color conversion section 52 is provided as described above, and the light emission range is determined by the position of the outer contour of the first through-hole 30a near the second surface 102: in some embodiments, the backlight module does not have a light blocking section 51. In other embodiments, the backlight module has a light blocking section 51. When the backlight module has a light blocking section 51, there are two cases.

[0198] The first scenario: As shown in Figure 27, the light blocking part 51 is not disposed between the first groove 10a and the second reflective layer 30.

[0199] The second scenario: As shown in Figure 28, the light blocking part 51 is disposed between the first groove 10a and the second reflective layer 30. The first plane is perpendicular to the second surface 102 and passes through the geometric center of the orthographic projection of the first through hole 30a on the second surface 102. Specifically, referring to Figure 21, one of the boundary points of the cross section of the first reflective layer 20 on the first plane away from the second surface 102 is the first boundary point e1 (e2), and one of the boundary points of the cross section of the first through hole 30a on the first plane close to the second surface 102 is the third boundary point g1 (g2). The first boundary point e1 (e2) and the third boundary point g1 (g2) are located on the same side of the protruding structure 11. The straight line segment connecting the first boundary point e1 (e2) and the third boundary point g1 (g2) is the second boundary line p1 (p2). The light blocking part 51 does not overlap with the second boundary line p1 (p2). At this time, the light blocking part 51 can be set in the first groove 10a, but it does not affect the range of light emitted from the first through hole 30a.

[0200] Furthermore, in some embodiments, the outer contour of the portion of the color conversion part 52 that exposes the first through hole 30a on the first plane and faces the first reflective layer 20 overlaps with the second boundary line p1 (p2). Specifically, as shown in Figures 29 to 30, in the direction from the first surface 101 to the second surface 102, the distance between the side of the color conversion part 52 away from the second surface 102 and the surface of the outer contour of the first reflective layer 20 away from the second surface 102 is H3, and the distance between the outer contour of the color conversion part 52 projected onto the second surface 102 and the outer contour of the first reflective layer 20 projected onto the second surface 102 is X3, and the ratio of X3 to H3 is greater than 0.7.

[0201] In this embodiment, the color conversion unit 52 extends beyond the light emission range defined by the first through hole 30a. Therefore, the actual light emission range is determined by the edge position of the side of the color conversion unit 52 furthest from the second surface 102. The beneficial effects are the same as in the aforementioned embodiment, and will not be repeated here.

[0202] Furthermore, referring to FIG30, the dimension of the side of the color conversion part 52 away from the second surface 102 in the direction parallel to the second surface 102 can vary with the distance between the color conversion part 52 and the second surface 102. Specifically, as the distance between the side of the color conversion part 52 closer to the second surface 102 and the second surface 102 decreases, the dimension of the side of the color conversion part 52 away from the second surface 102 in the direction parallel to the second surface 102 gradually increases. For example, the two points on the edge of the cross-section perpendicular to the second surface 102 at the side of the color conversion part 52 away from the second surface 102 are located on the two third boundary lines w1 and w2 shown in any of the figures in FIG20. As shown in Figure 21, the third boundary line w1 is the line connecting the first boundary point e1 on the same side of the first reflective layer 20 away from the second surface 102 on the same cross section and the fourth boundary point k1 of the end of the color conversion part 52 near the second surface 102 on the cross section perpendicular to the second surface 102. The third boundary line w2 is the line connecting the first boundary point e2 on the first reflective layer 20 away from the second surface 102 and the fourth boundary point k2 of the end of the color conversion part 52 near the second surface 102 on the cross section perpendicular to the second surface 102.

[0203] When the light emission range is actually determined by the edge position of the side surface of the color conversion unit 52 away from the second surface 102, furthermore, in some embodiments, the backlight module does not have a light blocking part 51. In other embodiments, the backlight module has a light blocking part 51. When the backlight module has a light blocking part 51, there are two cases.

[0204] The first scenario: As shown in Figure 31, the light blocking part 51 is not disposed between the first groove 10a and the second reflective layer 30.

[0205] The second scenario: As shown in Figure 32, the light-blocking part 51 is disposed between the first groove 10a and the second reflective layer 30. The first plane is perpendicular to the second surface 102 and passes through the geometric center of the orthographic projection of the first through hole 30a onto the second surface 102. One of the boundary points of the cross-section of the first reflective layer 20 on the first plane away from the second surface 102 is the first boundary point e1 (e2). One of the boundary points of the cross-section of the color conversion part 52 on the first plane near the second surface 102 is the fourth boundary point k1 (k2). The first boundary point e1 (e2) and the fourth boundary point k1 (k2) are located on the same side of the protruding structure 11. The straight line segment connecting the first boundary point e1 (e2) and the fourth boundary point k1 (k2) is the third boundary line w1, w2. The light-blocking part 51 does not overlap with the third boundary line w1, w2. The specific analysis is the same as in the previous embodiment, and will not be repeated here.

[0206] This application also provides a method for manufacturing a backlight module.

[0207] The following section uses the backlight module shown in Figure 8 above as an example to describe the detailed process of its fabrication:

[0208] Step 100: As shown in FIG33, a mask layer 92 is formed on the first surface 101 of the original substrate 10'. Referring to FIG34, the mask layer 92 includes a first mask portion 921 and at least one second mask portion 922. The first mask portion 921 has at least one mask through-hole 921a. A second mask portion 922 is located within one mask through-hole 921a of the first mask portion 921, and a gap exists between the second mask portion 922 and the first mask portion 921. The surface of the second mask portion 922 may be circular, and the mask through-hole 921a of the first mask portion 921 may be circular. The center of the surface of each second mask portion 922 may coincide with the center of the mask through-hole 921a of the first mask portion 921 to which it is located. The diameter of the surface of the second mask portion 922 is D1, the diameter of the through hole of the first mask portion 921 can be D2, and the distance between the edge of the mask through hole 921a of the first mask portion 921 and the edge of the second mask portion 922 is b. Then D2 = D1 + 2b.

[0209] In some embodiments, D1 ≥ 5 μm. The value of D1 is related to the height of the subsequently formed protrusion structure 11; the larger D1 is, the greater the height of the formed protrusion structure 11. By setting D1 ≥ 5 μm, it is possible to avoid the protrusion structure 11 being too small, which would result in the first reflective layer 20 covering the side of the protrusion structure 11 being too small, thus reducing the amount of light emitted by the light-emitting device 40 reflected by the first reflective layer 20 and failing to effectively improve the light utilization rate.

[0210] In some embodiments, b ≥ 2 μm. This configuration avoids the distance between the edge of the mask via 921a of the first mask portion 921 and the edge of the second mask portion 922 being too small, which would affect the contact between the etching solution and the original substrate 10'.

[0211] In some embodiments, the material of the mask layer 92 may be a metal, such as molybdenum. The mask layer 92 may be formed using a photomask.

[0212] Step 200: As shown in Figure 35, the original substrate 10' is etched using a wet etching process to form a first groove 10a, and a substrate 10 including the first groove 10a and a protruding structure 11 located in the first groove 10a are obtained.

[0213] In this step, the etching solution contacts the original substrate 10' through the gap between the first mask portion 921 and the second mask portion 922, and etches the original substrate 10' to form the substrate 10 and the protrusion structure 11. Due to the presence of the second mask portion 922, the area of ​​the original substrate 10' covered by it is not completely etched away; the retained area is the protrusion structure 11. Both the substrate 10 and the protrusion structure 11 are part of the original substrate, that is, the substrate 10 and the protrusion structure 11 are integrally formed; there is a gap between the protrusion structure 11 and the side of the first groove 10a. In this step, while the etching solution is etching the original substrate 10', when the etching solution etches away the portion of the original substrate 10' covered by the second mask portion 922, the second mask portion 922 will fall into the first groove 10a and be immersed in the etching solution and etched away.

[0214] Step 300: As shown in Figure 36, remove the first mask portion 921.

[0215] Step 400: As shown in Figure 37, a first reflective layer 20 is formed in the first groove 10a;

[0216] Step 500: As shown in Figure 38, a first sub-filling layer 611 is formed in the first groove 10a;

[0217] Step 600: As shown in FIG39, a light blocking portion 51 is formed on the side of the first sub-filling layer 611 away from the second surface 102. The light blocking portion 51 includes a second through hole 51a.

[0218] Step 700: As shown in FIG40, a second sub-filling layer 612 is formed on the side of the first sub-filling layer 611 away from the second surface 102, and the second sub-filling layer 612 is disposed around the light blocking portion 51; the second sub-filling layer 612 and the first sub-filling layer 611 together constitute the first filling layer 61;

[0219] In some embodiments, the side surface of the second sub-filling layer 612 away from the second surface 102 is flush with the side surface of the light blocking portion 51 away from the second surface 102.

[0220] Step 800: As shown in FIG41, an auxiliary layer 90, a second reflective layer 30, a plurality of light-collecting structures 31 arranged at intervals on the side of the first filling layer 61 away from the second surface 102, and an insulating layer 72 on the side of the second reflective layer 30 away from the substrate 10 are sequentially formed.

[0221] Step 900: As shown in FIG42, a color conversion part 52 is formed in the second through hole 51a of the light blocking part 51.

[0222] In some embodiments, the side surface of the color conversion portion 52 away from the second surface 102 is flush with the side surface of the light blocking portion 51 away from the second surface 102.

[0223] Step 1000: As shown in FIG43, a conductive pad 71 is formed on the side of the insulating layer 72 away from the substrate 10.

[0224] Step 1100: As shown in Figure 44, bind the light-emitting device 40 to the conductive pad 71;

[0225] Step 1200: As shown in Figure 45, a second filling layer 62 is formed between the light-emitting device 40 and the insulating layer 72;

[0226] Step 1300: As shown in Figure 46, a third reflective layer 80 is formed on the side of the light-emitting device 40 away from the substrate 10.

[0227] The embodiments of the backlight module preparation method provided in this application and the embodiments of the backlight module belong to the same inventive concept. The relevant details and beneficial effects can be referred to each other, and will not be repeated here.

[0228] This application also provides a display device, as shown in FIG47. The display device includes the aforementioned backlight module and a display panel 200 located on the side of the substrate 10 away from the light-emitting device 40. The display panel 200 may be a liquid crystal display panel.

[0229] In some embodiments, the display panel 200 may be a liquid crystal display panel, comprising an array substrate 201 and a counter substrate 202 disposed opposite to each other, and a liquid crystal layer 203 located between the array substrate 201 and the counter substrate 202. Specifically, the substrate 10 of the backlight module may be reused as the substrate of the array substrate 201, meaning that the film structure of the array substrate 201 can be directly fabricated on the surface of the substrate 1 of the backlight module, thereby facilitating a further reduction in the thickness of the display device. In some embodiments, the substrate 1 of the backlight module may also be reused as the substrate of the counter substrate 202, meaning that the film structure of the counter substrate 202 can be directly fabricated on the surface of the substrate 1 of the backlight module, without limitation.

[0230] It should be noted that the display device can be any device that displays images, whether moving (e.g., video) or fixed (e.g., still images), and whether it contains text or images. More specifically, the intended embodiments can be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigators, cockpit controllers and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0231] It should be understood that the embodiments described herein should be considered in a descriptive sense only and not for limiting purposes. The description of features or aspects within each embodiment should generally be considered as other similar features or aspects that may be used in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope defined by the claims and their equivalents.

Claims

1. A backlight module, characterized in that, include: The substrate includes a first surface and a second surface opposite to each other, and the first surface is provided with a first groove; A protruding structure is located within the first groove and spaced apart from the opening edge of the first groove; in the direction from the first surface to the second surface, the area of ​​the cross section of the protruding structure parallel to the second surface gradually increases; A first reflective layer, located within the first groove, at least covers the side surface of the protruding structure and exposes at least a portion of the side surface of the first groove; The second reflective layer is located on the side of the substrate away from the second surface. The second reflective layer is provided with a first through hole. The orthographic projection of the first through hole on the second surface of the substrate overlaps with the orthographic projection of the first groove on the second surface of the substrate. The light-emitting device and the second reflective layer are located on the same side of the substrate, and the light emitted by the light-emitting device enters the first groove through the first through hole; The backlight module further includes at least one of a light blocking part and a color conversion part; The light blocking portion is located on the side of the second reflective layer near the second surface. The light blocking portion is provided with a second through hole. The orthographic projection of the second through hole on the second surface at least partially overlaps with the orthographic projection of the first through hole on the second surface. The orthographic projection of the second through hole on the second surface at least partially overlaps with the orthographic projection of the first reflective layer on the second surface. The color conversion section is located on the side of the second reflective layer near the second surface, and the orthographic projection of the color conversion section on the second surface at least partially overlaps with the orthographic projection of the first through hole on the second surface.

2. The backlight module according to claim 1, characterized in that, The backlight module includes a light blocking portion, at least a portion of which is located within the first groove.

3. The backlight module according to claim 1 or 2, characterized in that, The backlight module includes a light blocking part, and the outer contour of the orthographic projection of the light blocking part on the second surface is located inside the edge of the orthographic projection of the first groove on the second surface.

4. The backlight module according to any one of claims 1 to 3, characterized in that, The backlight module includes a light blocking portion, and the orthographic projection of the first through hole of the second reflective layer on the second surface is located within the orthographic projection of the second through hole of the light blocking portion on the second surface.

5. The backlight module according to any one of claims 1 to 4, characterized in that, The backlight module includes a light blocking portion, and the orthographic projection of the second through hole of the light blocking portion on the second surface is located within the orthographic projection of the first reflective layer on the second surface.

6. The backlight module according to claim 5, characterized in that, In the direction from the first surface to the second surface, the distance between the side of the second through hole near the second surface and the outer contour of the first reflective layer away from the second surface is H1, and the distance between the outer contour of the orthographic projection of the second through hole on the second surface and the outer contour of the orthographic projection of the first reflective layer on the second surface is X1, and the ratio of X1 to H1 is greater than 0.

7.

7. The backlight module according to claim 6, characterized in that, The backlight module includes a color conversion section; the color conversion section is located on the side of the protruding structure away from the second surface, and the light blocking section is disposed around the color conversion section, wherein... The distance between the side of the color conversion part near the second surface and the second surface is greater than or equal to the distance between the end of the second through hole near the second surface and the second surface; Alternatively, the distance between the side of the color conversion part near the second surface and the second surface is less than the distance between the end of the second through hole near the second surface and the second surface. The first plane is perpendicular to the second surface and passes through the geometric center of the orthographic projection of the second through hole on the second surface. One point of the boundary of the first reflective layer on the first plane away from the second surface is the first boundary point. One point of the boundary of the second through hole on the first plane near the second surface is the second boundary point. The first boundary point and the second boundary point are located on the same side of the cross-section of the protruding structure on the first plane. The straight line segment connecting the first boundary point and the second boundary point is the first boundary line. The outer contour of the part of the color conversion part on the first plane that exposes the second through hole and faces the first reflective layer is located on the first boundary line or on the side of the first boundary line near the protruding structure.

8. The backlight module according to claim 7, characterized in that, The orthographic projection of the side surface of the color conversion part near the second surface onto the second surface lies within the orthographic projection of the second through hole of the light blocking part onto the second surface.

9. The backlight module according to claim 6, characterized in that, The backlight module includes a color conversion section; the color conversion section is located on the side of the second surface away from the first surface.

10. The backlight module according to claim 1, characterized in that, The backlight module includes a color conversion section located on the side of the protruding structure away from the second surface, and at least a portion of the color conversion section is located within the first groove.

11. The backlight module according to claim 1 or 10, characterized in that, The orthographic projection of the first through hole on the second surface lies within the orthographic projection of the first reflective layer on the second surface.

12. The backlight module according to claim 11, characterized in that, In the direction from the first surface to the second surface, the distance between the side of the first through hole near the second surface and the outer contour of the first reflective layer away from the second surface is H2, the distance between the outer contour of the orthographic projection of the first through hole on the second surface and the outer contour of the orthographic projection of the first reflective layer on the second surface is X2, and the ratio of X2 to H2 is greater than 0.

7.

13. The backlight module according to claim 12, characterized in that, The backlight module includes a color conversion section, which is located on the side of the protruding structure away from the second surface. The distance between the side of the color conversion part near the second surface and the second surface is greater than or equal to the distance between the end of the first through hole near the second surface and the second surface; Alternatively, the distance between the side of the color conversion part near the second surface and the second surface is less than the distance between the end of the first through hole near the second surface and the second surface; the first plane is perpendicular to the second surface and passes through the geometric center of the orthographic projection of the first through hole on the second surface; one point of the boundary of the first reflective layer on the side away from the second surface is the first boundary point; one point of the boundary of the first through hole on the side of the second surface is the third boundary point; the first boundary point and the third boundary point are located on the same side of the protruding structure; the straight line segment connecting the first boundary point and the third boundary point is the second boundary line; the outer contour of the part of the color conversion part on the first plane that exposes the first through hole and faces the first reflective layer is located on the second boundary line or on the side of the second boundary line near the protruding structure.

14. The backlight module according to claim 13, characterized in that, The orthographic projection of the side of the color conversion part closest to the second surface onto the second surface lies within the orthographic projection of the first through hole onto the second surface.

15. The backlight module according to claim 12, characterized in that, The color conversion section is located on the side of the second surface away from the first surface.

16. The backlight module according to any one of claims 12 to 15, characterized in that, The backlight module includes a light blocking part. The light-blocking portion is not disposed between the first groove and the second reflective layer; Alternatively, the light-blocking portion is disposed between the first groove and the second reflective layer, the first plane is perpendicular to the second surface and passes through the geometric center of the orthographic projection of the first through hole on the second surface, one of the boundary points of the cross section of the first reflective layer on the first plane away from the second surface is the first boundary point, one of the boundary points of the cross section of the first through hole on the first plane close to the second surface is the third boundary point, the first boundary point and the third boundary point are located on the same side of the protruding structure, the straight line segment connecting the first boundary point and the third boundary point is the second boundary line, and the light-blocking portion does not overlap with the second boundary line.

17. The backlight module according to claim 12, characterized in that, The distance between the side of the color-converting portion near the second surface and the second surface is less than the distance between the end of the first through-hole near the second surface and the second surface. A first plane is perpendicular to the second surface and passes through the geometric center of the orthographic projection of the first through-hole onto the second surface. One point on the boundary of the first reflective layer's cross-section on the first plane near the second surface is a first boundary point. One point on the boundary of the first through-hole's cross-section on the first plane away from the second surface is a third boundary point. The first and third boundary points are located on the same side of the protruding structure. The straight line segment connecting the first and third boundary points is a second boundary line. The outer contour of the portion of the color-converting portion on the first plane that exposes the first through-hole and faces the first reflective layer overlaps with the second boundary line. In the direction from the first surface to the second surface, the distance between the side of the color conversion part away from the second surface and the surface of the outer contour of the first reflective layer away from the second surface is H3, and the distance between the outer contour of the orthographic projection of the color conversion part on the second surface and the outer contour of the orthographic projection of the first reflective layer on the second surface is X3, and the ratio of X3 to H3 is greater than 0.

7.

18. The backlight module according to claim 17, characterized in that, The backlight module includes a light blocking part. The light-blocking portion is not disposed between the first groove and the second reflective layer; Alternatively, the light-blocking portion is disposed between the first groove and the second reflective layer, the first plane is perpendicular to the second surface and passes through the geometric center of the orthographic projection of the first through hole on the second surface, one of the boundary points of the cross section of the first reflective layer on the first plane away from the second surface is the first boundary point, one of the boundary points of the cross section of the color conversion portion on the first plane near the second surface is the fourth boundary point, the first boundary point and the fourth boundary point are located on the same side of the protruding structure, the straight line segment connecting the first boundary point and the fourth boundary point is the third boundary line, and the light-blocking portion does not overlap with the third boundary line.

19. The backlight module according to any one of claims 1 to 18, characterized in that, The backlight module further includes a first filling layer filled in the first groove, and the first filling layer is provided with a second groove; The backlight module includes a light blocking portion, at least a portion of which is located within the second groove; Alternatively, the backlight module includes a color conversion section, at least a portion of which is located within the second groove; Alternatively, the backlight module includes a light blocking portion and a color conversion portion, wherein at least one of the light blocking portion and at least one of the color conversion portion is located within the second groove.

20. The backlight module according to claim 19, characterized in that, In the direction from the first surface to the second surface, the depth of the second groove is less than the minimum distance between the first reflective layer and the first surface.

21. The backlight module according to any one of claims 1 to 18, characterized in that, The backlight module includes a color conversion section, the surface of which is furthest from the substrate and the surface of the second reflective layer furthest from the substrate.

22. The backlight module according to any one of claims 1 to 18, characterized in that, The backlight module includes a color conversion section, and the orthographic projection of the color conversion section on the second surface coincides with the orthographic projection of the first through hole of the second reflective layer on the second surface.

23. The backlight module according to any one of claims 1 to 18, characterized in that, The orthographic projection of the surface of the first reflective layer away from the second surface onto the second surface lies within the orthographic projection of the protruding structure onto the second surface.

24. The backlight module according to any one of claims 1 to 18, characterized in that, The backlight module includes a color conversion section, and the thickness of the color conversion section is greater than or equal to 20 μm in the direction from the first surface to the second surface.

25. The backlight module according to any one of claims 1 to 18, characterized in that, The side of the cross section of the protruding structure that is perpendicular to the second surface is curved; Alternatively, the side of the cross-section of the protruding structure perpendicular to the second surface is straight.

26. The backlight module according to any one of claims 1 to 18, characterized in that, The slope of the side of the section perpendicular to the second surface of the protruding structure ranges from 0.35 to 0.

85.

27. The backlight module according to any one of claims 1 to 18, characterized in that, The substrate and the protruding structure are an integral structure; Alternatively, the substrate and the protruding structure may be made of different materials.

28. The backlight module according to any one of claims 1 to 18, characterized in that, The distance between the point closest to the first reflective layer and the point farthest from the second surface in the direction parallel to the second surface is L1, and the distance between the point closest to the first reflective layer and the point farthest from the second surface in the direction perpendicular to the second surface is L2, and the ratio of L1 to L2 is less than 1.

7.

29. The backlight module according to any one of claims 1 to 18, characterized in that, The backlight module also includes: A conductive pad is located between the light-emitting device and the substrate, and the conductive pad is electrically connected to the light-emitting device; the orthographic projection of the conductive pad on the second surface is offset from the orthographic projection of the color conversion part on the second surface.

30. The backlight module according to claim 29, characterized in that, The thickness of the conductive pad is less than or equal to 2 μm.

31. The backlight module according to any one of claims 1 to 30, characterized in that, The second reflective layer has multiple light-collecting structures arranged at intervals on the side near the substrate.

32. The backlight module according to claim 31, characterized in that, The substrate comprises multiple microstructures, wherein, The light-collecting structure is a protrusion, and the microstructure is a first recessed structure, with each protrusion located within a corresponding first recessed structure; or... The light-collecting structure is a recessed portion, and the microstructure is a first protruding structure, with each recessed portion covering the corresponding first protruding structure.

33. The backlight module according to claim 31, characterized in that, The backlight module further includes an auxiliary layer disposed between the substrate and the second reflective layer. The auxiliary layer comprises multiple microstructures, wherein... The light-collecting structure is a protrusion, and the microstructure is a second recessed structure, with each protrusion located within a corresponding second recessed structure; or... The light-collecting structure is a recessed portion, and the microstructure is a second protruding structure, with each recessed portion covering the corresponding second protruding structure.

34. A display device, characterized in that, It includes a backlight module as described in any one of claims 1 to 33, and a display panel located on the side of the substrate away from the light-emitting device.

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