Light-emitting back plate, preparation method thereof and display device

Abstract

The embodiment of the invention provides a light-emitting backboard, a preparation method thereof and a display device, and the light-emitting backboard comprises a first substrate which is provided with a plurality of light-emitting units; wherein each light-emitting unit comprises a light-emitting body and an optical lens wrapping the light-emitting body; the optical lens comprises a first dielectric layer and a second dielectric layer, the second dielectric layer wraps the outer side of the first dielectric layer, and the refractive index of the second dielectric layer is smaller than that of the first dielectric layer. By applying the embodiment of the invention, the problem of checkerboard shadow of the display device can be improved, so that the display quality is improved.

Description

Technical Field

[0001] The present invention relates to the field of display technologies, and particularly to a light-emitting backplane, a method for manufacturing the same, and a display device. Background Art

[0002] MiniLED (mini-light-emitting diode) technology has become an important development direction in display technologies in recent years due to its advantages such as an affordable price and a long service life, and has been widely applied in fields such as large-size televisions, mid- to high-end displays, billboards, and display boards. For example, in the fields of televisions and displays, MiniLED technology is used in a large number of products due to its high resolution, precise light control, and rich color performance. With the progress of technology and the reduction of costs, its market penetration rate will further increase.

[0003] Currently, an important development trend of MiniLED technology is the thinning of the product form factor. Figure 1 FIG. shows a basic structure of a MiniLED display. A MiniLED display generally includes two parts: a liquid crystal panel and a backlight module. In the Figure 1 schematic illustration, the backlight module includes a PCB (Printed Circuit Board) board, LED lamp beads and a reflective film disposed on the PCB board, and a diffusion plate disposed between the reflective film and the liquid crystal panel. Among them, the distance between the reflective surface (i.e., the upper surface of the reflective film) on the side close to the PCB board where the light emitted by the LED lamp beads and the diffusion plate is called OD (Optical Distance). The light emitted by different LED lamp beads can be mixed within the OD range. Generally speaking, the larger the OD, the more sufficient the mixing of the light emitted by different LED lamp beads, and the better the brightness uniformity of the display.

[0004] Combined with Figure 1 it can be seen that in order to achieve the thinning of the product form factor, it is necessary to reduce the OD as much as possible. However, in the actual product structure, a relatively small OD may cause the light emitted by different LED lamp beads to be unable to achieve uniform mixing, and then there will be a Figure 2 phenomenon in the display shown in the schematic illustration where it is bright at the position of the LED lamp beads and dark between adjacent LED lamp beads, presenting a checkerboard shadow, resulting in the deterioration of the image quality of the display. Therefore, how to ensure the brightness uniformity of the light emitted by the backlight module while reducing the OD to achieve the thinning of the product form factor has become an urgent problem to be solved at present. Summary of the Invention

[0005] The objective of the embodiments of the present invention is to provide a light-emitting backplane, a preparation method thereof, and a display device, so as to improve the checkerboard shadow problem of the display device and thus enhance the display quality. The specific technical solutions are as follows:

[0006] In a first aspect, embodiments of the present application provide a light-emitting backplane, including:

[0007] A first substrate, on which a plurality of light-emitting units are provided;

[0008] Wherein, each of the light-emitting units includes a light-emitting body and an optical lens wrapping the light-emitting body; the optical lens includes a first dielectric layer and a second dielectric layer, the second dielectric layer wraps outside the first dielectric layer, and the refractive index of the second dielectric layer is less than that of the first dielectric layer.

[0009] Optionally, the thickness of the first dielectric layer in a first region is less than the thickness of the first dielectric layer around the first region; the orthographic projection of the first region on the first substrate is located within the projection range of the first dielectric layer on the first substrate.

[0010] Optionally, a concave area is formed at the top of the optical lens, and reflective ink is coated in the concave area.

[0011] Optionally, the outer surface of the optical lens is a rough surface after being roughened.

[0012] Optionally, the light-emitting backplane further includes at least one ink layer provided on the first substrate, and the ink layer does not cover the light-emitting units;

[0013] Wherein, the ink layer farthest from the first substrate is doped with reflective particles, or, reflective particles are sprayed on the surface of the ink layer away from the first substrate.

[0014] Optionally, the diameter of the reflective particles is 0.01 mm - 0.03 mm, and the volume doping concentration of the reflective particles in the ink layer is 10% - 40%.

[0015] Optionally, the reflective particles include large particles with a diameter not less than 0.2 mm and not greater than 0.3 mm, medium particles with a diameter not less than 0.1 mm and less than 0.2 mm, and small particles with a diameter not less than 0.01 mm and less than 0.1 mm, and the volume ratio of the large particles, the medium particles and the small particles is 1:3:6.

[0016] Optionally, the reflective particles include large particles, medium particles, and small particles, and the diameters of the large particles, the medium particles, and the small particles decrease in sequence; the large particles are disposed around each of the light-emitting units, the medium particles are disposed around the outer periphery of the area where the large particles are located, and the small particles are disposed in the shadow areas, IC deployment areas, and capacitor resistor deployment areas between adjacent light-emitting unit rows and adjacent light-emitting unit columns; wherein, the setting density of the large particles is greater than the setting density of the small particles.

[0017] Optionally, the reflective particle has a flat first surface and a second surface after roughening treatment.

[0018] Optionally, the light-emitting backplane further includes an ink layer disposed on the first substrate, and the ink layer does not cover the light-emitting units;

[0019] Wherein, a plurality of light guide dots are formed on the ink layer.

[0020] Optionally, the concentration and / or density of the light guide dots on the ink layer is negatively correlated with the distance between the light guide dots and the nearest light-emitting unit.

[0021] Optionally, the light-emitting backplane has a shadow area between adjacent light-emitting unit rows and adjacent light-emitting unit columns; the light-emitting backplane further includes an ink layer disposed on the first substrate, and the ink layer does not cover the light-emitting units;

[0022] Wherein, a light converging structure is disposed on at least one side of the ink layer away from the first substrate and located in the shadow area.

[0023] Optionally, the light converging structure is a first concave dot structure on the surface of the ink layer away from the first substrate, and the first concave dot structure is in the shape of a crystal cut surface.

[0024] Optionally, a second concave dot structure is formed on the surface of the ink layer away from the first substrate, the second concave dot structure is in a semi-spherical shape, and the light converging structure is a lens structure filled in the second concave dot structure.

[0025] Optionally, the density of the light converging structures at various positions on the ink layer is positively correlated with the distance between the position and the nearest light-emitting unit.

[0026] Optionally, the light-emitting backplane further includes: ink dots disposed around the light-emitting bodies in each of the light-emitting units and located between the first substrate and the optical lens.

[0027] In a second aspect, an embodiment of the present application provides a display device, including the light-emitting backplane according to any one of the foregoing first aspects.

[0028] In a third aspect, an embodiment of the present application provides a method for manufacturing a light-emitting backplane for manufacturing the light-emitting backplane according to any one of the foregoing first aspects. The method includes:

[0029] Obtain a first substrate and dispose a plurality of light-emitting bodies on the first substrate;

[0030] For each of the light-emitting bodies, form a first dielectric layer that wraps the light-emitting body;

[0031] For each of the light-emitting bodies, form a second dielectric layer that wraps the first dielectric layer outside the light-emitting body; the refractive index of the second dielectric layer is less than the refractive index of the first dielectric layer.

[0032] Advantageous effects of the embodiments of the present invention:

[0033] The light-emitting backplane, its manufacturing method, and the display device provided by the embodiments of the present invention configure an optical lens including a double-layer dielectric for the light-emitting bodies of the light-emitting units on the first substrate, and the refractive index of the outer second dielectric layer is less than the refractive index of the inner first dielectric layer. Based on this structure, before the light emitted by the light-emitting body exits the optical lens, it can first undergo a refraction at the junction of the first dielectric layer and the second dielectric layer. Since the refractive index of the second dielectric layer is less than the refractive index of the first dielectric layer, the light travels from an optically denser medium to an optically less dense medium, so the incident angle of the refracted light is less than the refraction angle. Therefore, compared with the optical lens structure with a single-layer dielectric, in the embodiments of the present application, the light can achieve an additional angular diffusion at the junction of the first dielectric layer and the second dielectric layer, so that the optical lens can achieve a stronger light diffusion ability, enabling the light emitted by each light-emitting unit on the first substrate to be more evenly emitted to the side away from the first substrate. Therefore, it helps to improve the problem of checkerboard shadow caused by uneven light brightness distribution, and thus can effectively improve the product image quality.

[0034] Of course, it is not necessary for any product or method implementing the present invention to simultaneously achieve all the above-mentioned advantages. Description of the Drawings

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other embodiments based on these drawings.

[0036] Figure 1 It is a schematic structural diagram of a MiniLED display in the related art;

[0037] Figure 2 It is a schematic diagram of a checkerboard shadow in a MiniLED display;

[0038] Figure 3(a) is a schematic diagram of the light-emitting backplane provided by the embodiment of the present application in the top view direction;

[0039] Figure 3(b) is a cross-sectional structure diagram of the light-emitting backplane provided by the embodiment of the present application;

[0040] Figure 4 It is a schematic diagram of a concave structure on the optical lens provided by the embodiment of the present application;

[0041] Figure 5 It is another schematic diagram of a concave structure on the optical lens provided by the embodiment of the present application;

[0042] Figure 6 It is a schematic diagram of embossing provided on the optical lens by the embodiment of the present application;

[0043] Figure 7 It is a schematic diagram of the positional relationship between the reflective ink coated on the optical lens and the light-emitting body in the top view direction provided by the embodiment of the present application;

[0044] Figure 8 It is a schematic diagram of the light intensity distribution of the light emitted by the light-emitting body provided by the embodiment of the present application;

[0045] Figure 9(a) is a schematic diagram when the ink layer of the light-emitting backplane provided by the embodiment of the present application is doped with reflective particles;

[0046] Figure 9(b) is a schematic diagram when the ink layer of the light-emitting backplane provided by the embodiment of the present application is coated with reflective particles;

[0047] Figure 10 It is a schematic diagram of a reflective particle provided by the embodiment of the present application;

[0048] Figure 11 It is a schematic diagram of the distribution of reflective particles provided by the embodiment of the present application;

[0049] Figure 12 It is a schematic diagram of the printing dots on the diffusion plate in the related art;

[0050] Figure 13 It is a schematic diagram of the light guide dots on the ink layer provided by the embodiment of the present application;

[0051] Figure 14(a) is a schematic diagram of a light converging structure on the ink layer provided by the embodiment of the present application;

[0052] Figure 14(b) is an enlarged view of the first concave dot structure in Figure 14(a);

[0053] Figure 15(a) is another schematic diagram of a light converging structure on the ink layer provided by the embodiment of the present application;

[0054] Figure 15(b) is an enlarged view of the second concave point structure in Figure 15(a);

[0055] Figure 16(a) is a schematic diagram of the ink dots in the light-emitting unit provided by the embodiment of the present application;

[0056] Figure 16(b) is a schematic diagram of the structure in Figure 16(a) in the top view direction;

[0057] Figure 17 It is a schematic diagram of the test points selected on the display device in the embodiment of the present application.

[0058] Reference numerals:

[0059] 1 - First substrate, 2 - Light-emitting unit, 21 - Light-emitting body, 22 - Optical lens, 22a - First dielectric layer, 22b - Second dielectric layer, 221 - Concave area, 3 - Ink layer, 31 - Reflective particles, 32 - Light guide dots, 33 - First concave point structure, 34 - Second concave point structure, 35 - Lens structure, 4 - Ink dots. Detailed implementation manners

[0060] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art based on the present application belong to the scope of protection of the present invention.

[0061] Currently, an important development trend of MiniLED technology is the thinning of the product form. Achieving the thinning of the product form requires minimizing the OD as much as possible. However, reducing the OD easily leads to the inability to achieve uniform light mixing of the light emitted by different LED beads, thus giving rise to the problem of checkerboard shadows. Therefore, how to ensure the brightness uniformity of the light emitted by the backlight module while reducing the OD has become an urgent problem to be solved currently.

[0062] To avoid the problem of checkerboard shadows caused by reducing the OD as much as possible, some manufacturers will make the light emitted by the backlight module as uniform as possible by increasing the number of LED beads on the PCB board and reducing the distance between adjacent LED beads. However, this solution will lead to a significant increase in product cost and is not conducive to improving product competitiveness.

[0063] In view of this, the embodiment of the present application provides a light-emitting backplane. When this light-emitting backplane is applied to LED products, it can ensure the brightness uniformity of the display while achieving the smallest possible OD and the number of LED lights, and has good market competitiveness. Referring to Figure 3(a), this light-emitting backplane includes:

[0064] A first substrate 1 is provided with a plurality of light-emitting units 2 thereon.

[0065] Among them, as shown in FIG. 3(b), each light-emitting unit 2 includes a light-emitting body 21 and an optical lens 22 that wraps the light-emitting body 21; the optical lens 22 includes a first dielectric layer 22a and a second dielectric layer 22b, the second dielectric layer 22b is wrapped outside the first dielectric layer 22a, and the refractive index of the second dielectric layer 22b is less than that of the first dielectric layer 22a.

[0066] In the embodiment of the present application, the light-emitting body 21 is a unit device for emitting light externally, and the first substrate 1 is used to arrange the light-emitting bodies 21. In one example, the first substrate 1 is a PCB board, and the light-emitting body 21 is an LED chip.

[0067] In the related art, the optical lens that wraps the LED is often formed by a dispensing process. However, for current products, the optical lens is generally composed of a single dielectric material. By reasonably designing the shape of the optical lens, the optical lens can be used to change the light-emitting angle and the light intensity distribution of the light emitted by the LED, realizing the secondary light distribution of the light emitted by the LED, so that the light emitted by the LED is more evenly distributed in the external space. In the embodiment of the present application, an optical lens 22 with a double-layer dielectric layer is configured for the light-emitting body 21. Since the refractive indices of the first dielectric layer 22a and the second dielectric layer 22b are different, before the light emitted by the light-emitting body 21 exits the optical lens 22, it can first undergo a refraction at the junction of the first dielectric layer 22a and the second dielectric layer 22b. The propagation direction of the refracted light is specifically related to the shaping radian of the first dielectric layer 22a and the refractive indices of the first dielectric layer 22a and the second dielectric layer 22b. Since the refractive index of the second dielectric layer 22b is less than that of the first dielectric layer 22a, the light travels from an optically denser medium to an optically thinner medium, so the incident angle of the refracted light is less than the refraction angle. Therefore, compared with the optical lens structure with a single-layer dielectric, in the embodiment of the present application, the light can achieve an additional angular diffusion at the junction of the first dielectric layer 22a and the second dielectric layer 22b.

[0068] Among them, in the embodiment of the present application, the shaping radian of the first dielectric layer 22a and the second dielectric layer 22b is not clearly limited, as long as the light diffusion effect of the optical lens 22 can be ensured. In one example, the second dielectric layer 22b can be formed into a shape similar to a concave lens based on the assistance of the first dielectric layer 22a. Specifically, that is, controlling the thickness of the second dielectric layer 22b at the center position directly above the first dielectric layer 22a to be less than the surrounding thickness. Thus, based on the principle of the concave lens, the light divergence ability of the second dielectric layer 22b is also stronger.

[0069] For the above reasons, compared with the single-layer dielectric optical lens 22 in the related art, in the light-emitting backplane provided in the embodiments of the present application, the multi-layer dielectric optical lens 22 can achieve stronger light diffusion ability, so that the light emitted by each light-emitting unit 2 on the first substrate 1 can be more evenly emitted to the side away from the first substrate 1. Therefore, when the light-emitting backplane is applied to a display device, it helps to improve the checkerboard shadow problem caused by uneven light brightness distribution, and can effectively improve the product image quality.

[0070] In an embodiment of the present application, an air dielectric layer can be set as the first dielectric layer 22a, and the second dielectric layer 22b can be formed by a dispensing process. During the preparation process, after the light-emitting body 21 is disposed on the first substrate 1, the light-emitting body 21 can be first covered by a transparent cover, an air dielectric layer is formed between the light-emitting body 21 and the transparent cover, and then the second dielectric layer 22b is formed on the outer layer of the transparent cover by a dispensing process. Specifically, by adjusting the density of the colloid used in the dispensing process to be less than that of air, the refractive index of the second dielectric layer 22b can be made less than that of the first dielectric layer 22a.

[0071] In another embodiment of the present application, colloid materials with different refractive indexes can also be used to sequentially form the first dielectric layer 22a and the second dielectric layer 22b through two successive dispensing processes.

[0072] In an embodiment of the present application, reference can be made to Figure 4 for the schematic illustration. By shaping the optical lens 22 that wraps the light-emitting body 21, a concave area 221 is formed at the top of the optical lens 22 to enhance the light diffusion ability of the optical lens 22.

[0073] For the optical lens 22 adopting a double-layer dielectric layer structure, referring to Figure 5 for the schematic illustration, the concave area 221 is specifically formed at the top of the second dielectric layer 22b.

[0074] In the actual preparation process, generally, a hemispherical shape of the optical lens 22 is first formed by dispensing with a glue gun, and then the colloid is cured to obtain a cured hemisphere. In the embodiments of the present application, when the colloid is formed and not completely cured, a concave shape can be punctured at the top of the hemispherical colloid to form an optical lens 22 with a concave area 221.

[0075] The embodiments of the present application do not limit the shape, depth, and direct size of the concave area 221. In short, by forming the concave area 221 at the top of the optical lens 22, based on the principle of a concave lens, the concave area 221 can increase the light opening angle after the secondary light distribution of the light-emitting body 21 through the optical lens 22, that is, increase the light-emitting angle of the light-emitting unit 2, thereby helping to improve the checkerboard shadow problem.

[0076] In one embodiment of the present application, the outer surface of the optical lens 22 can also be roughened so that its outer surface presents a rough surface.

[0077] The scope of the roughening treatment in the embodiments of the present application is not limited. In practical applications, the entire outer surface of the optical lens 22 can be roughened, or only a partial area thereof can be roughened, and both can achieve the effect of diffuse reflection of light.

[0078] In one example, before the colloid of the optical lens 22 is completely cured, the outer surface of the colloid can be embossed to achieve the roughening treatment. The present application does not specifically limit the texture of the embossing process, as long as the outer surface of the colloid can be roughened. For example, reference can be made to Figure 6 embossing the optical lens 22.

[0079] In another example, the roughening treatment of the outer surface of the optical lens 22 can also be achieved by sandblasting.

[0080] In the embodiments of the present application, by roughening the outer surface of the optical lens 22, the optical lens 22 can perform a secondary diffuse reflection on the light after secondary light distribution through its roughened outer surface, making the outgoing light more uniform, thereby improving the problem of checkerboard shadow. In practical applications, the diffuse reflection effect of the optical lens 22 on light can be adjusted by adjusting the density or gap size of the embossing / sandblasting to ensure that the outgoing angle of the light after diffuse reflection meets the requirements.

[0081] In one embodiment of the present application, reflective ink can also be coated on the position of the outer surface of the optical lens 22 directly above the light-emitting body 21 to improve the checkerboard shadow problem. The positional relationship between the coated reflective ink and the light-emitting body 21 in the top view direction can be referred to Figure 7 .

[0082] For Figure 4 the optical lens 22 with a recessed area 221 formed at the top shown in, specifically, reflective ink can be coated in the recessed area 221.

[0083] Specifically, the LED chip as the light-emitting body 21 is usually a cosine light-emitting body 21, also known as a Lambert (J.H. Lambert) light-emitting body 21, and the intensity schematic diagram of the light emitted by it is as shown in Figure 8As shown, it can be seen that its luminous brightness is related to the direction, and the luminous intensity is the largest directly above. Considering this characteristic, in the embodiment of the present application, reflective ink is coated at the corresponding position on the outer surface of the optical lens 22 directly above the light-emitting body 21, which can reflect the light emitted by the light-emitting body 21 directly upward to other positions for emission, thereby reducing the brightness of the area directly above the light-emitting body 21. Therefore, when the light-emitting backplane provided by the embodiment of the present application is applied to an LED display device, it can reduce the picture quality graininess caused by the bright light at the LED lamp position and the dark surroundings after the light exits the screen, so as to improve the problem of checkerboard shadow.

[0084] In an embodiment of the present application, referring to Figures 9(a) to 9(b) the example of, an ink layer 3 is further provided on the surface of the first substrate 1 where the light-emitting unit 2 is provided. The ink layer 3 is formed by coating high-reflectivity ink and can be used to reflect the light emitted by the light-emitting unit 2, thereby improving the light utilization rate and brightness uniformity of the product. In practical applications, only one ink layer 3 can be coated, or as Figures 9(a) to 9(b) schematically shown in, multiple ink layers 3 are coated in sequence, for example, 2 to 3 layers, depending on actual needs.

[0085] In one example, the reflective film that is usually provided on the first substrate can be cancelled, and multiple ink layers 3 are coated on the first substrate 1 to increase the reflectivity, thereby compensating for the brightness loss caused by cancelling the reflective film and saving the cost of the reflective film.

[0086] In the embodiment of the present application, referring to the example of Fig. 9(a), reflective particles 31 can be doped in the ink layer 3, or referring to the example of Fig. 9(b), reflective particles 31 are sprayed on the surface of the ink layer 3 away from the first substrate 1 to increase the diffuse reflection effect of the ink layer 3 on light, so that the light emitted by the light-emitting unit 2 can achieve more uniform light mixing within a specific OD range, so as to improve the problem of checkerboard shadow.

[0087] The reflective particles 31 specifically refer to particles that can achieve diffuse reflection of light, and materials such as nylon, PMMA (Polymethyl Methacrylate, plexiglass), etc. can be used for preparation. The embodiments of the present application do not specifically limit the shape of the reflective particles 31, as long as they can play a role in diffuse reflection of light. Generally speaking, the rougher and more irregular the surface of the reflective particles 31, the better the diffuse reflection effect. In a possible implementation manner of the present application, it can be required that the reflective particles 31 have a flat first surface and a second surface after roughening treatment at the same time. Thus, when the reflective particles 31 satisfying this morphology are sprayed on the surface of the ink layer 3, it can be expected that the reflective particles 31 can stand better on the ink layer 3 through their first surface. Because the contact surface flatness between the first surface of the reflective particles 31 and the ink layer 3 is higher, the combination of the two will be closer and it is less likely to fall off, while the rough second surface can better diffuse and transmit light. Figure 10 A specific example of the morphology of the reflective particles 31 is given. It has two flat surfaces on the top and bottom, and the surface between the two flat surfaces is rough and dull. By adopting this morphological design, it can increase the probability that the sprayed reflective particles 31 contact the ink layer 3 through their flat surfaces, thereby helping to avoid the situation where the reflective particles 31 fall off from the ink layer 3.

[0088] When adopting the scheme of doping the reflective particles 31 in the ink layer 3, at least the reflective particles 31 should be doped in the ink layer 3 that is farthest from the first substrate 1, that is, the uppermost ink layer 3. In the actual product structure, most of the light irradiated on the ink layer 3 will be reflected by the uppermost ink layer 3, and only a small part of the light can enter the lower ink layer 3. Therefore, by doping the reflective particles 31 in the uppermost ink layer 3, it helps to maximize the diffuse reflection effect of light, thereby improving the checkerboard shadow problem.

[0089] In the actual preparation process, before coating the last ink layer 3, the reflective particles 31 can be first incorporated into the ink and stirred evenly, and then the last ink layer 3 can be coated with the ink containing the reflective particles 31.

[0090] In one example, the volume concentration of the reflective particles 31 in the last ink layer 3 can be controlled within 10%-40%. Specifically, the higher the concentration of the reflective particles 31 in the ink layer 3, the better the diffuse reflection effect of light. However, correspondingly, the higher the concentration of the reflective particles 31, the higher the peeling risk of the ink layer 3. By controlling the concentration of the reflective particles 31 within this range, it helps to avoid the problem of peeling of the ink layer 3 while ensuring the diffuse reflection effect. In practical applications, the specific doping concentration of the reflective particles 31 can be adjusted according to the adhesion of the ink used.

[0091] When adopting the solution of spraying reflective particles 31 on the surface of the ink layer 3, after the last ink layer 3 is coated, the reflective particles 31 can be coated on its surface by spraying.

[0092] In an embodiment of the present application, when the reflective particles 31 are doped in the ink layer 3 or sprayed on the surface of the ink layer 3, the diameter of the reflective particles 31 can be controlled to be 0.01 mm (millimeter) - 0.3 mm.

[0093] In one example, reflective particles 31 of different specifications can be mixed and used, and the reflective particles 31 of different specifications are evenly distributed in the ink layer 3. For example, the reflective particles 31 can be divided into three different specifications of large particles, medium particles and small particles according to the order of diameter from large to small. When adopting the solution of doping the reflective particles 31 in the ink layer 3, the large, medium and small particles of the three different specifications can be doped into the ink and stirred evenly, and then the last ink layer 3 is formed by coating the ink doped with the reflective particles 31, so that the large, medium and small particles in the whole ink layer 3 are evenly distributed; when adopting the solution of spraying the reflective particles 31 on the surface of the ink layer 3, after the large, medium and small particles of the three different specifications are mixed evenly, the reflective particles 31 can be evenly coated above the uppermost ink layer 3 by spraying, so that the large, medium and small particles in the whole ink layer 3 are evenly distributed.

[0094] When the reflective particles 31 of the three different specifications of large, medium and small are evenly distributed, the concentration ratio between the reflective particles 31 of different specifications can be adjusted according to the actual situation, and the embodiments of the present application do not limit this. As an example, the reflective particles 31 can be divided into large particles with a diameter not less than 0.2 mm and not more than 0.3 mm, medium particles with a diameter not less than 0.1 mm and less than 0.2 mm, and small particles with a diameter not less than 0.01 mm and less than 0.1 mm, and the concentration ratio of large particles: medium particles: small particles is set to 1:3:6.

[0095] Specifically, for the embodiment in which the reflective particles 31 of the three different specifications of large, medium and small are evenly doped in the uppermost ink layer 3 and the volume ratio between the three different specifications of reflective particles is set to 1:3:6, the inventor of the present application has carried out simulation verification on the brightness uniformity of the display device when applying this light-emitting backplane through the 9-point test method. During the test, 9 test points are selected in the display device with reference to the Figure 17 schematic diagram, and the brightness of each test point is measured. The brightness uniformity obtained by the measurement is ≥ 80%. Among them, the brightness uniformity refers to the ratio of the minimum value to the maximum value of the brightness values of the 9 test points. Based on this test result, it can be seen that the embodiments of the present application can better improve the problem of checkerboard shadow.

[0096] In another example, non-uniform distribution can also be performed on the reflective particles 31 of different specifications and sizes, and the reflective particles 31 of different specifications and sizes are distributed in different positions in different regions. For example, the reflective particles 31 can be divided into three different specifications of large particles, medium particles, and small particles in the order from large to small in diameter, and with reference to Figure 11 As shown in the schematic diagram, with the light-emitting unit 2 as the center, the large particles are arranged around each light-emitting unit 2, the medium particles are arranged in the second circle outside the large particles, and the small particles are arranged in the shadow areas, IC deployment areas, and capacitor and resistor deployment areas between adjacent light-emitting unit rows and adjacent light-emitting unit columns.

[0097] Those skilled in the art can understand that in an LED display, it is easy to have a situation where the area around the light-emitting unit 2 is bright while the boundary position between adjacent light-emitting units 2 is dark. The shadow area referred to in the embodiments of the present application refers to the position that appears dark. Therefore, the shadow area can be specifically understood as the area on the light-emitting backplane where the brightness is less than a preset value (the size of the preset value can be set according to the actual situation). In the actual product structure, the shadow area can also be understood as Figure 2 the area that generates the checkerboard shadow shown in the schematic diagram. In addition, in the actual product structure, to realize the normal function of the light-emitting backplane, generally, a driving IC (Integrated Circuit), a capacitor structure, and a resistor structure need to be arranged on the first substrate 1. The IC deployment area is the area for arranging the driving IC, and the capacitor and resistor deployment area is the area for deploying the capacitor structure or the resistor structure.

[0098] Specifically, since the brightness of the area around the light-emitting unit 2 is generally the highest, by arranging large particles around it and setting the number of large particles to be large and distributed densely, as many light rays in this area as possible can be diffused by these large particles, that is, the point light source formed by the light-emitting unit 2 can be diffused into a surface light source as much as possible; by arranging medium particles in the second circle around the light-emitting unit 2, the already diffused light rays can be diffusely scattered a second time by the medium particles, and the density of the medium particles can be specifically adjusted according to the actual situation; while the shadow areas, IC deployment areas, and capacitor and resistor deployment areas are inherently darker areas, so small particles can be arranged in these areas and the number of these small particles is small and the distribution is sparse, so that the diffused light rays can be retained as much as possible in these darker areas and not diffusely scattered too much for this part of the light rays.

[0099] It can be seen that based on the above method, non-uniform setting of the three different specifications of large, medium, and small reflective particles 31 helps to equalize the light intensity between different regions of the light-emitting backplane, thereby being able to improve the problem of checkerboard shadow.

[0100] In the actual manufacturing process, when adopting the solution of doping reflective particles 31 in the ink layer 3, the ink can be doped with large particles, medium particles, and small particles respectively to obtain three kinds of inks doped with different specifications of reflective particles, and then the inks doped with each specification of reflective particles are coated on the corresponding areas in three coating steps; when adopting the solution of spraying reflective particles 31 on the surface of the ink layer 3, the large particles, medium particles, and small particles can be coated on the corresponding areas on the ink layer 3 in three spraying steps.

[0101] Furthermore, based on the setting solutions of the reflective particles 31 with different specifications given in the previous paragraph, for the transition regions between the large particles, medium particles, and small particles, these three different specifications of reflective particles 31 can be doped and then set in this transition region, and the concentration of the reflective particles 31 in this transition region can be adjusted according to the actual situation to achieve a smooth transition between different regions, playing a role in light homogenization and making the light emitted by the light-emitting backplane more uniform.

[0102] It can be seen from the above description that when adopting the design solution of uniformly distributing reflective particles 31 with different specifications and sizes on the ink layer 3, the overall process flow is more simplified, and when adopting the design solution of unevenly distributing reflective particles 31 with different specifications and sizes in different regions on the ink layer 3, the light distribution in different regions of the light-emitting backplane can be adjusted more pertinently. The two technical solutions have their own focuses, and in actual applications, the specific layout solution of reflective particles 31 with different specifications can be selected according to specific requirements.

[0103] As mentioned in the previous text, in order to improve the product competitiveness as much as possible, it is necessary to improve the brightness uniformity of the light emitted by the backlight module on the premise of being able to achieve as small an OD as possible and without increasing the number of LED lamp beads. Some manufacturers achieve this goal by screen-printing the diffusion plate. The printed diffusion plate is as Figure 12 shown. For the positions that are brighter directly above the LED lamp beads, the brightness of these positions can be reduced by screen-printing. For the positions that are darker between the LED lamp beads (i.e., the positions where checkerboard shadows are generated as shown in Figure 2 ), through the transitional design of the dots, the brightness of the positions directly above the LEDs can be smoothly transitioned to the dark positions, so that the light emitted by the backlight module will be more uniform as a whole, and the problem of checkerboard shadows can be improved.

[0104] Considering that in actual production, the printing process of the diffusion plate has the problem of relatively high cost, thus in an embodiment of the present application, at least one ink layer 3 can be coated on the side of the first substrate 1 provided with the light-emitting unit 2, and screen-printed dots (light guide dots 32) are made on the uppermost ink layer 3 with reference to the Figure 13 schematic diagram to improve the brightness uniformity of the light emitted by the light-emitting backplane and improve the problem of checkerboard shadows.

[0105] Specifically, the dot design of the light guiding dots 32 on the ink layer 3 can refer to the dot design during the printing of the diffusion plate, as long as it can play a role in evenly illuminating the light brightness at different positions of the backplane. In the embodiment of the present application, by forming the light guiding dots 32 on the ink layer 3, the dot printing on the diffusion plate can be cancelled. Since forming dots on the ink layer 3 has a lower process cost than the diffusion plate printing, it is more helpful to save the production cost of the product to enhance the product competitiveness.

[0106] As an example, in the actual production process, the dot screen printing for the ink layer 3 can be realized by using the inherent dot structure of the hot-pressed light guide plate. Specifically, after the coating of the ink layer 3 is completed, the hot-pressed light guide plate provided with the dot structure can be imprinted on the surface of the uppermost ink layer 3 away from the first substrate 1 to form the light guiding dot 32 structure on the ink layer 3.

[0107] In one example, after doping the ink with the reflective particles 31, the ink layer 3 doped with the reflective particles 31 can be coated, and then the light guiding dots 32 are formed on the ink layer 3. Exemplarily, the diameter of the reflective particles 31 can be 0.01 mm - 0.1 mm.

[0108] In an embodiment of the present application, reference can be made to Figure 13 the schematic diagram in, and the density of the light guiding dots 32 at each position on the ink layer 3 is set to be negatively correlated with the distance between this position and the nearest light emitting unit 2. That is to say, the closer to the light emitting unit 2, the denser the distribution of the light guiding dots 32, and the farther away from the light emitting unit 2, the sparser the distribution of the light guiding dots 32.

[0109] As mentioned in the foregoing, in the LED display, it is easy to have a situation where it is bright around the light emitting unit 2 and dark at the junction between adjacent light emitting units 2. Therefore, in the embodiment of the present application, by setting the light guiding dots 32 to be dense first and then sparse with the light emitting unit 2 as the center, the light in the brighter area around the light emitting unit 2 can be diffused as much as possible through the light guiding dots 32, and the light in the darker area farther away from the light emitting unit 2 is diffused less, so as to be able to adjust the overall brightness uniformity of the light emitted from the light emitting backplane and improve the problem of checkerboard shadow.

[0110] In practical applications, the light guide dots 32 can also be colored. Specifically, the light guide dots 32 can be colored with a uniform color concentration, or they can be divided into regions and colored with different color concentrations according to different regions, so as to further adjust the brightness uniformity of the entire light-emitting backplane, depending on actual needs. In an embodiment of the present application, the color concentration of the light guide dot 32 can be set to be negatively correlated with the distance between the light guide dot 32 and the nearest light-emitting unit 2. That is to say, the closer the distance to the light-emitting unit 2, the deeper the color concentration of the light guide dot 32, and the farther the distance to the light-emitting unit 2, the shallower the color concentration of the light guide dot 32.

[0111] Specifically, in addition to reflecting light, the light guide dot 32 may also absorb light. Generally speaking, the higher the color concentration of the light guide dot 32, the higher its light absorption rate. Therefore, in the embodiment of the present application, by setting the color concentration of the light guide dot 32 to be deep first and then shallow with the light-emitting unit 2 as the center, the light guide dot 32 can absorb part of the light in the region with a higher brightness around the light-emitting unit 2 to reduce the brightness of this region, and achieve a smooth transition between this region and the darker region at the boundary with the adjacent light-emitting unit 2, thereby being able to adjust the brightness uniformity of the entire light-emitting backplane and improve the problem of checkerboard shadow.

[0112] In an embodiment of the present application, a light converging structure can also be provided on the side of the ink layer 3 away from the first substrate 1, and the light converging structure is at least provided in the shadow region mentioned above.

[0113] Among them, the light converging structure can be used to reflect light and make the reflected light converge as much as possible directly above its own region. Therefore, in the embodiment of the present application, by providing a light converging structure in the shadow region between adjacent light-emitting unit rows and adjacent light-emitting unit columns, the light diffused into the shadow region can be kept in the shadow region as much as possible, which helps to adjust the brightness non-uniformity between different regions of the light-emitting backplane and improve the problem of checkerboard shadow. Two specific schemes for implementing the light converging structure are given in the subsequent embodiments of the present application, which will be described separately below.

[0114] In one example, referring to the schematic diagram of FIG. 14(a), the light converging structure is specifically a first concave dot structure 33 on the surface of the ink layer 3 away from the first substrate side. The specific form of the first concave dot structure 33 can be referred to FIG. 14(b). It can be seen that the inside of the first concave dot structure 33 is specifically in the shape of a crystal cutting surface.

[0115] In the schematic diagram of FIG. 14(b), the cross-section inside the first concave point structure 33 specifically includes a four-sided mirror-like surface, but the structures that can actually be selected are not limited to this. For example, an eight-sided mirror-like surface can also be formed inside the first concave point structure 33. In practical applications, the specific number and angle of the cross-section inside the first concave point structure 33 can be adjusted to adjust the angle of the light reflected by the first concave point structure 33, so as to improve the uneven light brightness situation.

[0116] In the actual production process, generally, the ink needs to be coated first, and then the coated ink is cured to form a cured ink layer 3. For the embodiments of the present application, before the coated ink is completely cured, the first concave point structure 33 can be pressed on the ink through a mold in the shape of a crystal cutting surface.

[0117] In another example, referring to the schematic diagram of FIG. 15(a), a second concave point structure 34 is formed on the side of the ink layer 3 away from the first substrate. The specific shape of the second concave point structure 34 can be referred to FIG. 15(b). It can be seen that the depth H1 in the middle of the second concave point structure 34 is shallower than the depth H2 of the periphery, presenting a semi-spherical shape, and the light converging structure is a lens structure 35 filled in the second concave point structure 34.

[0118] Specifically, since the lens structure 35 filled in the second concave point structure 34 is specifically a convex lens, after the light enters the lens structure 35 and is reflected by the ink layer 3, part of the light can converge directly above the second convex point structure, so as to improve the uneven brightness state where it is bright around the light-emitting unit 2 and dark at the junction between the light-emitting units 2.

[0119] In the actual production process, before the coated ink is completely cured, the second concave point structure 34 can be pressed on the ink through a mold in the shape of a semi-spherical shape, and then transparent glue is injected into the second concave point structure 34. After the transparent glue is dried by baking, the lens structure 35 can be formed. In practical applications, the refractive index of the transparent glue and the height of the concave point (i.e., the size of H1) can be adjusted to adjust the focal length and the position of the focus of the lens structure 35, so as to better improve the problem of checkerboard shadow.

[0120] In one example, for the light converging structures provided at various positions on the ink layer 3, the density of the light converging structures at various positions on the ink layer 3 can be made positively correlated with the distance between this position and the nearest light-emitting unit 2. That is to say, the closer to the light-emitting unit 2, the sparser the distribution of the light converging structures, and the farther away from the light-emitting unit 2, the denser the distribution of the light converging structures. Through this design, the darker areas far from the light-emitting unit 2 can retain the diffused light as much as possible, realizing a smooth transition of light between different regions in the light-emitting backplane, thereby improving the problem of checkerboard shadow.

[0121] In addition, in the preparation process flow of the light-emitting backplane, generally, an optical lens 22 encapsulating the light-emitting body 21 is first formed through a dispensing process, and then ink is coated around the optical lens 22. In an embodiment of the present application, this process can be improved, that is, after the light-emitting body 21 is arranged, ink dots 4 are first printed around the light-emitting body 21, and then the optical lens 22 encapsulating the light-emitting body 21 is formed. Thus, as shown in FIGS. 16(a) and 16(b), in the final product structure, the ink dots 4 can be formed between the optical lens 22 and the first substrate 1, specifically under the optical lens 22.

[0122] Among them, the color concentration and roughness of the ink dots 4 can be selected according to actual needs, and the embodiments of the present application do not limit this.

[0123] In the embodiment of the present application, before the light emitted by the light-emitting body 21 exits the optical lens 22, the ink dots 4 located inside the optical lens 22 can absorb or reflect and diffuse some of the light, realizing the first optical path adjustment. When the light further exits the optical lens 22, the optical lens 22 can change its light pattern and emission angle, realizing the second optical path adjustment. Thus, multiple optical path adjustments can be achieved for the light emitted from the light-emitting body 21, and better uniformity of the emitted light can be realized, thereby improving the problem of checkerboard shadow.

[0124] Based on the same inventive concept, the embodiment of the present application also provides a method for preparing a light-emitting backplane. This preparation method can be used to prepare the light-emitting backplane provided in any of the foregoing embodiments of the present application. Specifically, the method includes:

[0125] Obtain a first substrate and arrange a plurality of light-emitting bodies on the first substrate;

[0126] For each light-emitting body, form a first dielectric layer encapsulating the light-emitting body;

[0127] For each light-emitting body, form a second dielectric layer encapsulating the first dielectric layer outside the light-emitting body; the refractive index of the second dielectric layer is less than that of the first dielectric layer.

[0128] Regarding the specific structure of the light-emitting backplane provided in the foregoing embodiments of the present application, the preparation process involved has been described in the corresponding product embodiments. Therefore, for more content and beneficial effects of this preparation method, reference can be made to the descriptions in the foregoing text, and details will not be repeated here.

[0129] Based on the same inventive concept, the embodiment of the present application also provides a display device, which includes the light-emitting backplane provided in any of the foregoing embodiments of the present application.

[0130] Exemplarily, the display device may further specifically include other structures such as a diffusion plate, a liquid crystal panel, etc., which can be set according to actual needs, and the embodiments of the present application do not limit this.

[0131] It should be noted that, in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0132] Each embodiment in this specification is described in a related manner. For the same or similar parts among the embodiments, reference can be made to each other, and the differences between each embodiment and other embodiments are emphasized.

[0133] The above are only the preferred embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are all included in the protection scope of the present invention.

Claims

1. A light-emitting backplane, characterized in that: include: a first substrate, on which a plurality of light-emitting units are disposed; Each of the light-emitting units includes a light-emitting body and an optical lens wrapping the light-emitting body; the optical lens includes a first medium layer and a second medium layer, the second medium layer is wrapped around the outside of the first medium layer, and the refractive index of the second medium layer is smaller than the refractive index of the first medium layer.

2. The light-emitting backplane according to claim 1, characterized in that: The thickness of the first dielectric layer in the first region is smaller than the thickness of the first dielectric layer around the first region; the orthographic projection of the first region on the first substrate is located within the projection range of the first dielectric layer on the first substrate.

3. The light-emitting backplane according to claim 1, characterized in that: A concave area is formed on the top of the optical lens, and reflective ink is coated in the concave area.

4. The light-emitting backplane according to claim 1, characterized in that: The outer surface of the optical lens is a rough surface after roughening treatment.

5. The light-emitting backplane according to claim 1, characterized in that: The light-emitting backplane further comprises at least one ink layer disposed on the first substrate, wherein the ink layer does not cover the light-emitting unit; The ink layer farthest from the first substrate is doped with reflective particles, or the surface of the ink layer farthest from the first substrate is sprayed with reflective particles.

6. The light-emitting backplane according to claim 5, characterized in that: The diameter of the reflective particles is 0.01 mm-0.03 mm, and the volume doping concentration of the reflective particles in the ink layer is 10%-40%.

7. The light-emitting backplane according to claim 5, characterized in that: The reflective particles include large particles with a diameter of not less than 0.2 mm and not more than 0.3 mm, medium particles with a diameter of not less than 0.1 mm and less than 0.2 mm, and small particles with a diameter of not less than 0.01 mm and less than 0.1 mm. The volume ratio of the large particles, the medium particles and the small particles is 1:3:

6.

8. The light-emitting backplane according to claim 5, characterized in that: The reflective particles include large particles, medium particles and small particles, and the diameters of the large particles, the medium particles and the small particles decrease in sequence; the large particles are arranged around each of the light-emitting units, the medium particles are arranged along the outer circle of the area where the large particles are located, and the small particles are arranged in the shadow area, IC deployment area and capacitor and resistor deployment area between adjacent light-emitting unit rows and adjacent light-emitting unit columns; wherein the setting density of the large particles is greater than the setting density of the small particles.

9. The light-emitting back panel according to claim 5, characterized in that: The reflective particles have a flat first surface and a roughened second surface.

10. The light-emitting backplane according to claim 1, characterized in that: The light-emitting backplane further comprises an ink layer disposed on the first substrate, wherein the ink layer does not cover the light-emitting unit; Wherein, a plurality of light-guiding dots are formed on the ink layer.

11. The light-emitting back panel according to claim 10, characterized in that: The concentration and / or density of the light-guiding dots on the ink layer is negatively correlated with the distance between the light-guiding dots and the nearest light-emitting unit.

12. The light-emitting backplane according to claim 1, characterized in that: The light-emitting backplane has a dark shadow area between adjacent light-emitting unit rows and adjacent light-emitting unit columns; the light-emitting backplane also includes an ink layer disposed on the first substrate, and the ink layer does not cover the light-emitting units; Wherein, a light focusing structure at least located in the dark shadow area is provided on a side of the ink layer away from the first substrate.

13. The light-emitting back panel according to claim 12, characterized in that: The light focusing structure is a first concave point structure on a surface of the ink layer on a side away from the first substrate, and the first concave point structure is in the shape of a crystal cutting surface.

14. The light-emitting back panel according to claim 12, characterized in that: A second concave point structure is formed on a surface of the ink layer on a side away from the first substrate, the second concave point structure is hemispherical, and the light focusing structure is a lens structure filled in the second concave point structure.

15. The light-emitting back panel according to claim 12, characterized in that: The density of the light-converging structures at each position on the ink layer is positively correlated with the distance between the position and the nearest light-emitting unit.

16. The light-emitting backplane according to claim 1, characterized in that: The light-emitting back plate further includes: ink dots surrounding the light-emitting body in each light-emitting unit and located between the first substrate and the optical lens.

17. A display device, characterized in that: A light-emitting backplane comprising any one of claims 1-16.

18. A method for preparing a light-emitting backplane, characterized in that: For preparing a light-emitting backplane according to any one of claims 1 to 16, the method comprising: Obtain a first substrate, and arrange a plurality of light-emitting bodies on the first substrate; For each of the luminous bodies, forming a first medium layer encapsulating the luminous body; For each of the light-emitting bodies, a second medium layer is formed to wrap the first medium layer outside the light-emitting body; the refractive index of the second medium layer is smaller than the refractive index of the first medium layer.

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