Backlight module, preparation method thereof and display panel

Abstract

The application relates to a backlight module, a preparation method thereof and a display panel. The backlight module comprises a substrate, a plurality of light emitting devices arranged on one side of the substrate, and an optical structure comprising a plurality of light transmission films and arranged on a side of the plurality of light emitting devices away from the substrate. A diffusion layer is arranged between two adjacent light transmission films, the diffusion layer encloses a plurality of first openings, the plurality of first openings are arranged correspondingly to the plurality of light emitting devices, the orthographic projection of the light emitting devices on the substrate is located in the orthographic projection of the corresponding first opening on the substrate, a first light transmission material is arranged in the first opening, a second light transmission material is arranged on the side of the optical structure facing the substrate, and the refractive index of the light transmission film is greater than the refractive index of the first light transmission material and the second light transmission material. Therefore, the backlight module, the preparation method thereof and the display panel provided by the application can relieve the lamp shadow phenomenon of the backlight module, so as to improve the display effect of the display panel.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to backlight modules and their manufacturing methods, and display panels. Background Technology

[0002] Liquid crystal display (LCD) panels require a backlight module to provide a uniform surface light source. A common solution for backlight modules is to place LED (Light-Emitting Diode) light sources and lenses at the bottom, and place a diffuser plate at a certain height above the LED light sources to convert the light from multiple LED light sources into a uniform surface light source.

[0003] In related technologies, the development of local dimming technology has led to the emergence of Mini-LED backlight technology. The principle of local dimming is to divide the backlight area into several independently controllable small areas, known as zones, and adjust the brightness of the backlight zones according to the grayscale levels of the image corresponding to each zone. This function can make blacks darker and whites brighter, thus significantly improving the contrast of LCD displays.

[0004] However, the aforementioned backlight module has a negative impact on the display effect of the display panel. Summary of the Invention

[0005] Therefore, it is necessary to provide a backlight module and its manufacturing method, as well as a display panel, which can alleviate the shadow phenomenon of the backlight module and improve the display effect of the display panel.

[0006] In a first aspect, embodiments of this application provide a backlight module, the backlight module comprising:

[0007] substrate;

[0008] Multiple light-emitting devices are disposed on one side of the substrate;

[0009] An optical structure, including multiple layers of transparent films, is disposed on the side of multiple light-emitting devices facing away from the substrate;

[0010] In this structure, a diffusion layer is provided between two adjacent light-transmitting films, and the diffusion layer encloses and forms multiple first openings. The multiple first openings are correspondingly provided with multiple light-emitting devices. The orthogonal projection of the light-emitting device on the substrate is located within the orthogonal projection of the corresponding first opening on the substrate. A first light-transmitting material is provided inside the first opening. A second light-transmitting material is provided in contact with the side of the optical structure facing the substrate. The refractive index of the light-transmitting film is greater than the refractive index of the first light-transmitting material and the second light-transmitting material.

[0011] In one embodiment, the backlight module includes a first reflective layer disposed between a substrate and an optical structure. The first reflective layer encloses and forms a plurality of second openings, which are correspondingly disposed with a plurality of light-emitting devices, and the light-emitting devices are located within the corresponding second openings.

[0012] In one embodiment, the backlight module includes a plurality of first adhesive portions and a plurality of second adhesive portions spaced apart. Any two of the first adhesive portions, second adhesive portions and light-emitting devices are correspondingly arranged. The first adhesive portions are located in the corresponding second opening and on the outer periphery of the corresponding light-emitting device. The second adhesive portions are located on the side of the corresponding light-emitting device away from the substrate and are bonded to the first adhesive portions.

[0013] In one embodiment, the thickness of the first reflective layer is greater than or equal to the thickness of the light-emitting device.

[0014] In one embodiment, the backlight module includes a second reflective layer, which includes a plurality of sub-reflective portions spaced apart, the sub-reflective portions forming a third opening, and the plurality of sub-reflective portions being correspondingly disposed with a plurality of light-emitting devices; the orthographic projection of the light-emitting device on the substrate overlaps with the orthographic projection of the corresponding third opening on the substrate.

[0015] In one embodiment, the sub-reflective portion is annular in shape, and the orthographic projection of the light-emitting device on the substrate is located within the orthographic projection of the third opening on the substrate; and / or,

[0016] Both the first and second light-transmitting materials are air; the light-transmitting film is glass.

[0017] Secondly, embodiments of this application provide a method for fabricating a backlight module, the method comprising:

[0018] An optical structure is formed and multiple light-emitting devices are formed on one side of a substrate; the optical structure includes multiple light-transmitting films, a diffusion layer is disposed between two adjacent light-transmitting films, and the diffusion layer surrounds and forms multiple first openings; a first light-transmitting material is disposed within the first opening;

[0019] An optical structure is disposed on the side of the light-emitting device away from the substrate; multiple first openings are disposed corresponding to multiple light-emitting devices, and the orthographic projection of the light-emitting device on the substrate is located within the orthographic projection of the corresponding first opening on the substrate. A second light-transmitting material is disposed in contact with the side of the optical structure facing the substrate, and the refractive index of the light-transmitting film is greater than the refractive index of the first light-transmitting material and the second light-transmitting material.

[0020] In one embodiment, after forming a plurality of light-emitting devices on one side of the substrate, the optical structure is disposed on the side of the light-emitting devices away from the substrate, including: forming a first reflective layer on the side of the substrate facing the light-emitting devices; the first reflective layer enclosing a plurality of second openings, the plurality of second openings being disposed corresponding to the plurality of light-emitting devices, and the light-emitting devices being located within the corresponding second openings.

[0021] In one embodiment, after forming a first reflective layer on the side of the substrate facing the light-emitting device, the method includes: forming a first initial adhesive portion in each of the second openings;

[0022] The method of placing an optical structure on the side of the light-emitting device away from the substrate includes: forming a plurality of second initial adhesive portions on one side of the optical structure; and curing the second initial adhesive portions to form second adhesive portions.

[0023] The optical structure is disposed on the side of the light-emitting device away from the substrate, including: disposing a second adhesive portion on the side of the corresponding first initial adhesive portion away from the substrate; curing the first initial adhesive portion to form a first adhesive portion, and bonding the first adhesive portion and the second adhesive portion together.

[0024] The first initial bonding portion and the second initial bonding portion are in a liquid state.

[0025] Thirdly, embodiments of this application provide a display panel, which includes a backlight module as described in the first aspect, or a backlight module obtained by the method for preparing a backlight module as described in the second aspect.

[0026] The backlight module and its manufacturing method, as well as the display panel provided in this application embodiment, involve total internal reflection of some of the light emitted by the light-emitting device at the interface between the first light-transmitting film and the first light-transmitting material. The reflected light then undergoes total internal reflection again at the interface between the first light-transmitting film and the second light-transmitting material. This process is repeated, causing the light to be repeatedly reflected between the first and second interfaces and propagate to the area corresponding to the gap between two adjacent light-emitting devices. When the total internally reflected light irradiates the diffusion layer, it is diffused and emitted uniformly outward. Even if the light mixing distance between the light-emitting device and the optical structure is set to be small, the brightness of the area corresponding to the gap between two adjacent light-emitting devices can be improved. This reduces the difference in brightness between the area corresponding to the gap between two adjacent light-emitting devices and the area corresponding to the light-emitting device, thereby alleviating the shadow phenomenon of the backlight module and improving the display effect of the display panel. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the backlight module provided in an embodiment of this application.

[0028] Figure 2This is another structural schematic diagram of the backlight module provided in an embodiment of this application.

[0029] Figure 3 This is a schematic flowchart illustrating the fabrication method of the backlight module provided in the embodiments of this application.

[0030] Figure 4 This is a schematic diagram of the structure after the second reflective layer is formed on the second transparent film, as provided in an embodiment of this application.

[0031] Figure 5 This is a schematic diagram of the structure after the initial diffusion layer is formed on the second transparent film, as provided in an embodiment of this application.

[0032] Figure 6 This is a schematic diagram of the structure after the formation of the second initial adhesive portion, provided in an embodiment of this application.

[0033] Figure 7 This is a schematic diagram of the structure of the second initial adhesive portion and the initial diffusion layer after curing, as provided in the embodiments of this application.

[0034] Figure 8 This is a schematic diagram of a light-emitting device formed on a substrate, provided in an embodiment of this application.

[0035] Figure 9 This is a schematic diagram of the structure after the formation of the first reflective layer, provided in an embodiment of this application.

[0036] Figure 10a This is a schematic diagram of the structure after the formation of the first initial adhesive portion, provided in an embodiment of this application.

[0037] Figure 10b for Figure 7 Overall structure and Figure 10a A schematic diagram of the overall structure fitting together.

[0038] Figure 11 A schematic diagram of the backlight module provided for related technologies.

[0039] Figure 12 A schematic diagram of the structure of a display panel provided for related technologies.

[0040] Figure 13 A schematic diagram illustrating the light shadow generated by a backlight module provided for related technologies.

[0041] Figure 14 A schematic diagram showing the illumination of a single partition of the related technology and the presence of crosstalk.

[0042] Explanation of reference numerals in the attached figures:

[0043] 10. LCD display panel; 11. Backlight module; 12. LED light source; 13. Lens; 14. Diffuser plate; 15. Back panel; 16. Blue LED; 17. Mini-LED light panel; 18. Quantum dot film; 19. Optical film;

[0044] 100, Backlight module; 110, First reflective layer; 112, Second opening; 120, Second reflective layer; 121, Sub-reflective part; 123, Third opening; 130, Substrate; 140, Light-emitting device; 150, Optical structure; 151, Transparent film; 1511, First transparent film; 1512, Second transparent film; 152, Diffusion layer; 152e, Initial diffusion layer; 1521, First opening; 161, First adhesive part; 161e, First initial adhesive part; 162, Second adhesive part; 162e, Second initial adhesive part; J1, First interface; J2, Second interface. Detailed Implementation

[0045] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0046] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0047] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only 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" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0050] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0051] In related technologies, see Figure 11 In a liquid crystal display panel, a backlight module 10 is required to provide a uniform surface light source. A common solution for the backlight module 10 is to place LED light sources 11 and lenses 12 at the bottom, and then place a diffuser plate 13 at a height h from the LED light sources 11 to convert the light from the multiple LED light sources 11 into a uniform surface light source. The distance h is 20-30 mm, and the spacing between two adjacent LEDs is about 100 mm.

[0052] The development of local dimming technology led to the emergence of Mini-LED backlighting. Local dimming divides the backlight area into several independently controllable small zones (regions), adjusting the brightness of each zone based on the grayscale level of the corresponding image. This allows for darker blacks and brighter whites, significantly improving the contrast of LCD displays. Mini-LED backlighting technology was developed to increase the number of backlight zones, further enhancing the display effect of LCD panels. (See also...) Figure 12 An LCD display panel 1 with Mini-LEDs, the LCD display panel 1 includes a back plate 14, a Mini-LED light panel 16, a blue LED 15, a diffuser plate 13, a quantum dot film 17, an optical film 18, and an LCD module 19 stacked in sequence.

[0053] However, because Mini-LEDs are very small LEDs, typically between 100-500 micrometers, a Mini-LED light board 16 contains thousands of blue LEDs 15 (Mini-LEDs). A diffuser plate 13 and other optical films are placed at a certain distance (OD) from the Mini-LEDs to convert the dotted blue light emitted by the thousands of Mini-LEDs into a uniform surface light source. To reduce costs, the number of Mini-LEDs needs to be minimized, which increases the spacing between them. If the mixing distance OD is too small, a uniform surface light source cannot be formed; instead, it produces circular light spots, such as... Figure 13 As shown, this phenomenon is called lamp shadow. The area corresponding to the gap between two adjacent Mini-LEDs has the lowest brightness, and the brightness difference between the area corresponding to the Mini-LED and the area corresponding to the gap between two adjacent Mini-LEDs is relatively large.

[0054] To eliminate the shadow effect, the light mixing distance, or OD value, needs to be increased. A common practice is to attach support pillars to the Mini-LED panel 16; for example, four support pillars can be spaced out. The height of the support pillars is related to the spacing between adjacent Mini-LEDs; when the spacing between adjacent Mini-LEDs is 10 mm, the support pillar height is 5 mm. The diffuser plate 13 has a thickness of 1.5 mm, and the total thickness of the optical film 18 is 1 mm. That is, the thickness from the surface of the Mini-LED panel 16 to the surface of the film is 7.5 mm.

[0055] One of the biggest problems with local dimming backlight technology is that when a single backlight zone is lit, light diffuses into surrounding zones. This phenomenon is called zone crosstalk, or halo, and it affects the actual display effect of the LCD. Figure 14As shown, the light spot produced when a single backlight zone is lit is much larger than the size of a single zone.

[0056] To reduce crosstalk between zones, an effective approach is to reduce the light mixing distance (OD) and the stacking thickness of the optical diffuser plate 13 and the diaphragm. However, current technology cannot reduce the OD value to zero or reduce the thickness of the diffuser plate 13. As mentioned earlier, when the mini-LED spacing is 10 mm, the vertical thickness from the surface of the Mini-LED panel 16 to the surface of the diaphragm is 7.5 mm. Therefore, new technologies are needed to reduce this 7.5 mm vertical thickness.

[0057] To address the aforementioned issues, this application provides a backlight module, its fabrication method, and a display panel, which can alleviate the shadow phenomenon of the backlight module and improve the display effect of the display panel.

[0058] The following will combine Figures 1-10a The backlight module, its manufacturing method, and the display panel provided in the embodiments of this application are described.

[0059] See Figure 1 and Figure 2This application provides a backlight module 100, which includes a substrate 130, a plurality of light-emitting devices 140, and an optical structure 150. The light-emitting devices 140 are disposed on one side of the substrate 130. The optical structure 150 includes multiple layers of light-transmitting films 151 and is disposed on the side of the plurality of light-emitting devices 140 away from the substrate 130. A diffusion layer 152 is disposed between two adjacent layers of light-transmitting films 151. The diffusion layer 152 forms a plurality of first openings 1521. The diffusion layer 152 is mesh-shaped. The plurality of first openings 1521 are correspondingly disposed with the plurality of light-emitting devices 140. The orthographic projection of the light-emitting device 140 on the substrate 130 is located within the orthographic projection of the corresponding first opening 1521 on the substrate 130. Two adjacent light-transmitting films 151 include a first light-transmitting film 1511 and a second light-transmitting film 1512. The first light-transmitting film 1511 is located on the side of the second light-transmitting film 1512 that is close to the substrate 130. A first light-transmitting material A1 is disposed in the first opening 1521. The refractive index of the light-transmitting film 151 is greater than the refractive index of the first light-transmitting material A1. A second light-transmitting material A2 is disposed in contact with the side of the optical structure 150 facing the substrate 130. The refractive index of the light-transmitting film 151 is greater than the refractive index of the second light-transmitting material A2. The first light-transmitting material A1 is in contact with the adjacent light-transmitting film 151.Thus, when the light emitted by the light-emitting device 140 (i.e., the dashed arrow G1) enters the first light-transmitting film 1511 and exits towards the first light-transmitting material A1, if the incident angle β of the light at the first interface J1 between the first light-transmitting film 1511 and the first light-transmitting material A1 is greater than or equal to the critical angle (the incident angle β is relatively large), the light ray G1 travels from the first light-transmitting film 1511 with a higher refractive index to the first light-transmitting material A1 with a lower refractive index. The light ray is completely reflected back into the first light-transmitting film 1511 at the interface J1 between the first light-transmitting film 1511 and the first light-transmitting material A1, resulting in total internal reflection. The reflected light ray undergoes total internal reflection again at the interface J2 between the first light-transmitting film 1511 and the second light-transmitting material A2. This process repeats, causing the light ray G1 from the light-emitting device 140 to be repeatedly totally internally reflected between the first interface J1 and the second interface J2, thus moving towards the space between two adjacent light-emitting devices 140. The light propagates in the area corresponding to the gap between the light-emitting devices 140 and the optical structure 150. When the totally reflected light shines on the diffusion layer 152, it is diffused and emitted uniformly outward. There is no need to set a large mixing distance OD between the light-emitting devices 140 and the optical structure 150 (for example, the mixing distance between the light-emitting devices 140 and the optical structure 150 can be close to 0). Even if the mixing distance OD between the light-emitting devices 140 and the optical structure 150 is set small, the brightness of the area corresponding to the gap between two adjacent light-emitting devices 140 can be improved. This reduces the brightness difference between the area corresponding to the gap between two adjacent light-emitting devices 140 and the area corresponding to the light-emitting device 140, thereby alleviating the shadow phenomenon of the backlight module 100 and improving the display effect of the display panel. In addition, it can also make the brightness of the area corresponding to the gap between two adjacent light-emitting devices 140 more uniform. Secondly, by setting the optical structure 150, the mixing distance OD between the light-emitting devices 140 and the optical structure 150 can be set smaller, which helps to reduce the crosstalk problem and also helps to reduce the thickness of the backlight module 100, thus achieving a thinner backlight module 100.

[0060] When the incident angle β of the large-angle light ray G1 is greater than or equal to the critical angle for total internal reflection at the first interface J1 and the second interface J2, the light ray G1 can undergo total internal reflection at the first interface J1 and the second interface J2 during propagation, so as to propagate to the region corresponding to the gap between two adjacent light-emitting devices 140 and irradiate the diffusion layer 152 and be emitted.

[0061] For example, the material of the diffusion layer 152 includes white glue.

[0062] For example, the light-emitting device 140 can be a mini-LED.

[0063] For example, the refractive indices of the first light-transmitting material A1 and the second light-transmitting material A2 can be the same.

[0064] For example, both the first light-transmitting material A1 and the second light-transmitting material A2 are air, and the light-transmitting film 151 is glass, where the refractive index of glass is greater than that of air. See also Figure 1 Between two adjacent transparent films 151, air can be located within the first opening 1521. Between the optical structure 150 and the substrate 130, air can surround the outer periphery of the second adhesive portion 162.

[0065] For example, the number of light-transmitting films 151 in the optical structure 150 can be any number of two, three, or more than three layers. This application embodiment uses two light-transmitting films 151 as an example for illustration. These two light-transmitting films 151 are arranged adjacent to each other and are respectively a first light-transmitting film 1511 and a second light-transmitting film 1512.

[0066] See Figure 1 In some embodiments, the backlight module 100 includes a first reflective layer 110 disposed between the substrate 130 and the optical structure 150. The first reflective layer 110 encloses and forms a plurality of second openings 112, and the plurality of second openings 112 are correspondingly disposed with a plurality of light-emitting devices 140. The light-emitting devices 140 are located within the corresponding second openings 112. Thus, by disposing the light-emitting devices 140 within the second openings 112 of the first reflective layer 110, the scattered light rays from the light-emitting devices 140 toward the side are reflected back to the direction of the optical structure 150 by the first reflective layer 110 at the sidewall of the second opening 112. The scattered light rays are guided to the optical structure 150 to participate in light emission, avoiding ineffective light dissipation in the gap between the substrate 130 and the optical structure 150. This is beneficial to improving the overall light efficiency of the backlight module 100 and achieving higher light emission brightness at the same power.

[0067] See Figure 1In some embodiments, the backlight module 100 includes a plurality of first adhesive portions 161 and a plurality of second adhesive portions 162. Any two of the first adhesive portions 161, second adhesive portions 162, and light-emitting devices 140 are correspondingly disposed. The first adhesive portion 161 is located within a corresponding second opening 112 and is located on the outer periphery of the corresponding light-emitting device 140, i.e., between the corresponding light-emitting device 140 and the sidewall of the corresponding second opening 112. The second adhesive portion 162 is located on the side of the corresponding light-emitting device 140 facing away from the substrate 130, and the second adhesive portion 162 is adjacent to the first adhesive portion 161. One adhesive portion 161 contacts and adheres to the other, thus, one side of the second adhesive portion 162 is adhered to the optical structure 150. The first adhesive portion 161 is adhered to the corresponding light-emitting device 140. The first adhesive portion 161 and the corresponding second adhesive portion 162 are used to adhere the corresponding light-emitting device 140 and the optical structure 150. For example, the first adhesive portion 161 and the second adhesive portion 162 can be formed using optically transparent adhesive. The first adhesive portion 161 and the second adhesive portion 162 are liquid and fluid before curing. The first adhesive portion 161 before curing is the first initial adhesive portion 161e. Figure 10a The second adhesive portion 162 before curing is the second initial adhesive portion 162e ( Figure 6 See also Figure 6 , Figure 7 and Figure 10a A second initial adhesive portion 162e can be prepared on the optical structure 150 and cured to form a second adhesive portion 162. A first initial adhesive portion 161e is formed within the second opening 112. Figure 7 Overall structure and Figure 10a The overall structure is bonded together so that the second adhesive part 162 comes into contact with the first initial adhesive part 161e, and then the first initial adhesive part 161e is cured to form the first adhesive part 161, and the first adhesive part 161 and the second adhesive part 162 are bonded together.

[0068] With this setting, Figure 7 Overall structure and Figure 10aDuring the overall structural bonding process, the second adhesive portion 162 can maintain its size and shape due to curing, while the first initial adhesive portion 161e is not cured and has fluidity. Under the pressure of the second adhesive portion 162, the first initial adhesive portion 161e deforms and fully contacts the second adhesive portion 162. At the same time, the first initial adhesive portion 161e is not easily overflowed and diffused out of the second opening 112 due to the restriction of the side wall of the second opening 112. The size of the second opening 112 limits the size of the second initial adhesive portion 162e, which can prevent the first initial adhesive portion 161e from spreading unevenly in all directions due to uneven pressure (due to the thixotropic properties of the convex adhesive). This is beneficial to control the shape and size of the first adhesive portion 161 after curing, so that the first adhesive portion 161 can be in a preset position and distributed relatively evenly. For example, the first adhesive portion 161 can be evenly distributed around the light-emitting device 140 as the center, preventing adverse effects on the propagation path of the light from the light-emitting device 140 after entering the optical structure 150. In addition, the first adhesive portion 161 and the second adhesive portion 162 bond the light-emitting device 140 and the optical structure 150 together, so that there is no air layer between the light-emitting device 140 and the optical structure 150. Air can be located on the outer periphery of the second adhesive portion 162, and the light emitted by the light-emitting device 140 can enter the optical structure 150 after passing through the first adhesive portion 161 and the second adhesive portion 162.

[0069] See Figure 1 For example, a portion of the first adhesive portion 161 may be located on the side of the corresponding light-emitting device 140 away from the substrate 130, and the second adhesive portion 162 may be located on the side of the corresponding first adhesive portion 161 away from the corresponding light-emitting device 140.

[0070] See Figure 1 For example, the surface of the second adhesive portion 162 facing away from the optical structure 150 can be a curved surface.

[0071] See Figure 1 In some embodiments, the thickness of the first reflective layer 110 is greater than or equal to the thickness of the light-emitting device 140. This results in a larger thickness of the first reflective layer 110, which can better guide the scattered light from the light-emitting device 140 to propagate toward the optical structure 150.

[0072] See Figure 1In some embodiments, the backlight module 100 includes a second reflective layer 120, which includes a plurality of sub-reflective portions 121 spaced apart. The sub-reflective portions 121 enclose a third opening 123. The plurality of sub-reflective portions 121 are correspondingly disposed with a plurality of light-emitting devices 140. The orthographic projection of the light-emitting device 140 on the substrate 130 overlaps with the orthographic projection of the third opening 123 on the substrate 130. Thus, the light G2 emitted by the light-emitting device 140 can be emitted through the third opening 123. Furthermore, when the small-angle light G3 emitted by the light-emitting device 140 shines on the sub-reflector 121, the sub-reflector 121 can reflect the small-angle light G3 back into the second light-transmitting film 1512 so that it can shine on the diffusion layer 152. The diffusion layer 152 can diffuse some of the light upward so that it can be emitted from the optical structure 150. In this way, the brightness of the area corresponding to the gap between two adjacent light-emitting devices 140 can be increased by using the small-angle light G3, further reducing the brightness difference between the area corresponding to the gap between two adjacent light-emitting devices 140 and the area corresponding to the light-emitting device 140, thereby further alleviating the lamp shadow phenomenon of the backlight module 100. In addition, by providing the third opening 123, at least the light G1 emitted by the light-emitting device 140 perpendicular to the substrate 130 can be emitted from the third opening 123, thereby preventing the sub-reflector 121 from excessively blocking the area directly above the light-emitting device 140, which would result in the brightness of the area corresponding to the sub-reflector 121 being too low.

[0073] For example, the brightness can be adjusted by adjusting at least one of the area of ​​the third opening 123 of the sub-reflector 121 and the distance between the inner edge and the outer edge of the sub-reflector 121.

[0074] For example, the sub-reflective portion 121 is annular in shape. For instance, the sub-reflective portion 121 may be circular in shape.

[0075] For example, the material of the sub-reflective portion 121 may include white oil.

[0076] In some embodiments, the orthographic projection of the light-emitting device 140 on the substrate 130 is located within the orthographic projection of the corresponding third opening 123 on the substrate 130. The area of ​​the third opening 123 is greater than or equal to the area of ​​the light-emitting device 140. In this way, all vertical light emitted by the light-emitting device 140 can be emitted through the third opening 123.

[0077] In other embodiments, the orthographic projection of the third opening 123 on the substrate 130 is located within the orthographic projection of the corresponding light-emitting device 140 on the substrate 130. In this case, the area of ​​the third opening 123 is less than or equal to the area of ​​the light-emitting device 140.

[0078] The following describes the preparation method of the backlight module 100 provided in the embodiments of this application.

[0079] This application provides a method for fabricating a backlight module 100, which can be used to fabricate the backlight module 100 described in the above embodiments. See also Figure 3 The preparation methods include:

[0080] Step S100: Forming an optical structure and forming multiple light-emitting devices on one side of the substrate; the optical structure includes multiple light-transmitting films, a diffusion layer is disposed between two adjacent light-transmitting films, and the diffusion layer surrounds to form multiple first openings; a first light-transmitting material is disposed in the first opening.

[0081] See Figure 7 and Figure 8 An optical structure 150 is formed, and a plurality of light-emitting devices 140 are formed on one side of a substrate 130. The optical structure 150 includes multiple layers of light-transmitting films 151, and a diffusion layer 152 is disposed between adjacent light-transmitting films 151. The diffusion layer 152 encloses a plurality of first openings 1521, and a first light-transmitting material A1 is disposed within the first openings 1521. Regarding the step of forming the optical structure 150, the plurality of light-emitting devices 140 can be formed on one side of the substrate 130 first, or they can be formed on one side of the substrate 130 later. This embodiment of the application describes an example of forming the optical structure 150 first, and then forming the plurality of light-emitting devices 140 on one side of the substrate 130.

[0082] Step S200: An optical structure is disposed on the side of the light-emitting device away from the substrate; multiple first openings are disposed corresponding to multiple light-emitting devices, the orthographic projection of the light-emitting device on the substrate is located within the orthographic projection of the corresponding first opening on the substrate, and a second light-transmitting material is disposed on the side of the optical structure facing the substrate, the refractive index of the light-transmitting film is greater than the refractive index of the first light-transmitting material and the second light-transmitting material.

[0083] See Figure 1 and 10bAn optical structure 150 is disposed on the side of the light-emitting device 140 facing away from the substrate 130. Multiple first openings 1521 are correspondingly disposed with multiple light-emitting devices 140. The orthographic projection of the light-emitting device 140 on the substrate 130 lies within the orthographic projection of the corresponding first opening 1521 on the substrate 130. A second light-transmitting material A2 is disposed in contact with the side of the optical structure 150 facing the substrate 130. The refractive index of the light-transmitting film 151 is greater than the refractive index of the first light-transmitting material A1 and the second light-transmitting material A2. This allows the light ray G1 from the light-emitting device 140 to be repeatedly totally internally reflected between the first interface J1 and the second interface J2, propagating towards the region corresponding to the gap between two adjacent light-emitting devices 140. When this totally internally reflected light shines... When light reaches the diffusion layer 152, it is diffused and emitted uniformly outwards. Therefore, it is not necessary to set a large mixing distance OD between the light-emitting device 140 and the optical structure 150; a smaller mixing distance OD can be used. This also improves the brightness of the area corresponding to the gap between adjacent light-emitting devices 140, reducing the brightness difference between the area corresponding to the gap and the area corresponding to each light-emitting device 140. This alleviates the shadow phenomenon in the backlight module 100 and improves the display effect of the display panel. Furthermore, it makes the brightness of the area corresponding to the gap between adjacent light-emitting devices 140 more uniform. This facilitates reducing the thickness of the backlight module 100, thus achieving a thinner backlight module. The principle has been explained and will not be repeated here.

[0084] See Figure 4 In some embodiments, before forming the optical structure 150, a second reflective layer 120 may be formed on one side of the second light-transmitting film 1512 of the optical structure 150, the second reflective layer 120 including a plurality of sub-reflective portions 121.

[0085] For example, multiple sub-reflective portions 121 are fabricated on the surface of the second light-transmitting film 1512 by screen printing or photolithography, and the distance between the centers of two adjacent sub-reflective portions 121 can be the same as the distance between the centers of two adjacent light-emitting devices 140.

[0086] See Figure 5 In some embodiments, after forming the second reflective layer 120, an initial diffusion layer 152e may be formed on the side of the second light-transmitting film 1512 opposite to the second reflective layer 120.

[0087] For example, the second light-transmitting film 1512, on which the second reflective layer 120 is disposed, is flipped so that the second reflective layer 120 is on the bottom surface of the second light-transmitting film 1512, and a grid-shaped initial diffusion layer 152e is made on the top surface of the second light-transmitting film 1512 using a dispensing process with white glue. The orthographic projection of each grid pattern on the second light-transmitting film 1512 surrounds the orthographic projection of a sub-reflective part 121 on the second light-transmitting film 1512.

[0088] See Figure 6 In some embodiments, after the initial diffusion layer 152e is formed, a first light-transmitting film 1511 is disposed on the side of the initial diffusion layer 152e that is opposite to the second light-transmitting film 1512.

[0089] For example, a first light-transmitting film 1511 is pressed onto the initial diffusion layer 152e. The width of the initial diffusion layer 152e increases under pressure, and its thickness decreases under pressure. This helps to reduce the gap between the first light-transmitting film 1511 and the second light-transmitting film 1512, which is beneficial for thinning the optical structure 150. It also reduces the material consumption of the initial diffusion layer 152e while maintaining its width. The initial diffusion layer 152e can form a diffusion layer 152 after subsequent curing.

[0090] See Figure 6 In some embodiments, before the optical structure 150 is disposed on the side of the light-emitting device 140 opposite to the substrate 130, it may include: forming a plurality of second initial adhesive portions 162e on the side of the first light-transmitting film 1511 of the optical structure 150 opposite to the second light-transmitting film 1512; thereafter, see Figure 7 The second initial adhesive portion 162e is cured to form the second adhesive portion 162.

[0091] See Figure 5 and Figure 6 For example, a raised adhesive pattern (i.e., the second initial bonding portion 162e) is made on the surface of the first light-transmitting film 1511 facing away from the second light-transmitting film 1512 using a dispensing process. The position of the second initial bonding portion 162e corresponds one-to-one with the sub-reflective portion 121.

[0092] See Figure 7 For example, during the curing process of the second initial adhesive portion 162e, the process may also include simultaneously curing the mesh-like initial diffusion layer 152e to form the diffusion layer 152. That is, simultaneously curing the initial diffusion layer 152e and the second initial adhesive portion 162e simplifies the manufacturing process.

[0093] See Figure 8 In some embodiments, after the second initial adhesive portion 162e is cured, the following can be performed: Figure 8The step involves forming a plurality of light-emitting devices 140 on one side of the substrate 130. For example, the substrate 130 can be a glass-based circuit board, and mini-LED chips (i.e., light-emitting devices 140) can be soldered onto the pads of the glass-based circuit board using solder paste.

[0094] See Figure 9 In some embodiments, after forming a plurality of light-emitting devices 140 on one side of the substrate 130, before setting the optical structure 150 on the side of the light-emitting devices 140 away from the substrate 130, the optical structure includes forming a first reflective layer 110 on the side of the substrate 130 facing the light-emitting devices 140; the first reflective layer 110 encloses a plurality of second openings 112, the plurality of second openings 112 being correspondingly disposed with respect to the plurality of light-emitting devices 140, and the light-emitting devices 140 being located within the corresponding second openings 112. For example, the first reflective layer 110 is attached to the substrate 130, and the first reflective layer 110 has second openings 112 at the positions corresponding to the light-emitting devices.

[0095] See Figure 10a In some embodiments, after forming a first reflective layer 110 on the side of the substrate 130 facing the light-emitting device 140, the method includes forming a first initial adhesive portion 161e in each of the second openings 112. For example, adhesive is filled in the second openings 112 of the first reflective layer 110, and the adhesive (i.e., the first initial adhesive portion 161e) covers the light-emitting device 140.

[0096] See Figure 10b In some embodiments, the optical structure 150 is disposed on the side of the light-emitting device 140 away from the substrate 130. This may include: attaching the optical structure 150, which has a second adhesive portion 162 and a sub-reflective portion 121, to the first reflective layer 110, and disposing the second adhesive portion 162 on the side of the corresponding first initial adhesive portion 161e away from the substrate 130. For example, see below. Figure 1 The second adhesive portion 162 can be embedded within the second opening 112 to bond with the filled first initial adhesive portion 161e. Subsequently, the first initial adhesive portion 161e is cured to form the first adhesive portion 161, and the first adhesive portion 161 and the second adhesive portion 162 are bonded together. The first initial adhesive portion 161e, the second initial adhesive portion 162e, and the initial diffusion layer 152e can be in a liquid state.

[0097] The following describes the display panel provided in the embodiments of this application.

[0098] This application provides a display panel, which includes the backlight module 100 described in the above embodiments. The display panel may include a liquid crystal display panel. The display panel includes an LCD module disposed on the side of the second reflective layer 120 facing away from the substrate 130.

[0099] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A backlight module, characterized in that, The backlight module includes: substrate; Multiple light-emitting devices are disposed on one side of the substrate; An optical structure, including multiple layers of light-transmitting film, is disposed on the side of the plurality of light-emitting devices facing away from the substrate; A diffusion layer is disposed between two adjacent light-transmitting films, and the diffusion layer encloses and forms a plurality of first openings. The plurality of first openings are disposed corresponding to the plurality of light-emitting devices. The orthographic projection of the light-emitting device on the substrate is located within the orthographic projection of the corresponding first opening on the substrate. A first light-transmitting material is disposed within the first opening. A second light-transmitting material is disposed in contact with the side of the optical structure facing the substrate. The refractive index of the light-transmitting film is greater than the refractive indices of the first light-transmitting material and the second light-transmitting material.

2. The backlight module according to claim 1, characterized in that, The backlight module includes a first reflective layer disposed between the substrate and the optical structure. The first reflective layer encloses and forms a plurality of second openings, which are correspondingly disposed with respect to the plurality of light-emitting devices, and the light-emitting devices are located within the corresponding second openings.

3. The backlight module according to claim 2, characterized in that, The backlight module includes a plurality of first adhesive portions and a plurality of second adhesive portions spaced apart. Any two of the first adhesive portions, the second adhesive portions, and the light-emitting devices are correspondingly arranged. The first adhesive portion is located in the corresponding second opening and on the outer periphery of the corresponding light-emitting device. The second adhesive portion is located on the side of the corresponding light-emitting device away from the substrate and is bonded to the first adhesive portion.

4. The backlight module according to claim 2, characterized in that, The thickness of the first reflective layer is greater than or equal to the thickness of the light-emitting device.

5. The backlight module according to any one of claims 1-4, characterized in that, The backlight module includes a second reflective layer, which includes a plurality of sub-reflective portions spaced apart. The sub-reflective portions enclose a third opening, and the plurality of sub-reflective portions are correspondingly disposed with the plurality of light-emitting devices. The orthographic projection of the light-emitting device on the substrate overlaps with the orthographic projection of the corresponding third opening on the substrate.

6. The backlight module according to claim 5, characterized in that, The sub-reflective portion is annular in shape, and the orthographic projection of the light-emitting device on the substrate is located within the orthographic projection of the third opening on the substrate; and / or Both the first and second light-transmitting materials are air; the light-transmitting film is glass.

7. A method for manufacturing a backlight module, characterized in that, The preparation method includes: An optical structure is formed and a plurality of light-emitting devices are formed on one side of a substrate; the optical structure includes multiple layers of light-transmitting films, a diffusion layer is disposed between two adjacent light-transmitting films, and the diffusion layer encloses to form a plurality of first openings; a first light-transmitting material is disposed within the first opening; The optical structure is disposed on the side of the light-emitting device away from the substrate; the plurality of first openings are disposed corresponding to the plurality of light-emitting devices, the orthographic projection of the light-emitting device on the substrate is located within the orthographic projection of the corresponding first opening on the substrate, and a second light-transmitting material is disposed in contact with the side of the optical structure facing the substrate, and the refractive index of the light-transmitting film is greater than the refractive indices of the first light-transmitting material and the second light-transmitting material.

8. The method for preparing a backlight module according to claim 7, characterized in that, After forming a plurality of light-emitting devices on one side of the substrate, the step of setting the optical structure on the side of the light-emitting devices away from the substrate includes: forming a first reflective layer on the side of the substrate facing the light-emitting devices; the first reflective layer enclosing a plurality of second openings, the plurality of second openings being correspondingly arranged with the plurality of light-emitting devices, and the light-emitting devices being located within the corresponding second openings.

9. The method for preparing a backlight module according to claim 8, characterized in that, After forming a first reflective layer on the side of the substrate facing the light-emitting device, the method includes: forming a first initial adhesive portion in each of the second openings; Before placing the optical structure on the side of the light-emitting device away from the substrate, the method includes: forming a plurality of second initial adhesive portions on one side of the optical structure; and curing the second initial adhesive portions to form second adhesive portions. The step of setting the optical structure on the side of the light-emitting device away from the substrate includes: setting the second adhesive portion on the side of the corresponding first initial adhesive portion away from the substrate; curing the first initial adhesive portion to form a first adhesive portion; and bonding the first adhesive portion and the second adhesive portion together. The first initial adhesive portion and the second initial adhesive portion are in a liquid state.

10. A display panel, characterized in that, The display panel includes the backlight module according to any one of claims 1-6, or the backlight module obtained by the preparation method of the backlight module according to any one of claims 7-9.

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