Backlight module and ultra-thin liquid crystal display

Abstract

The present invention relates to a backlight module and a display. The backlight module includes: a bracket, a lamp board, a first-stage light splitting array lens, a second-stage collimated light array lens, and a third-stage microstructure lens; the lamp board is provided with a plurality of light source bodies, and the first-stage light splitting array lens, the second-stage collimated light array lens, and the third-stage microstructure lens are sequentially arranged along the light-emitting direction of the light source bodies; a first light-transmitting microstructure is arranged on the surface of the third-stage microstructure lens facing the lamp board, and a second light-transmitting microstructure is arranged on the surface of the third-stage microstructure lens facing away from the lamp board, and the extending directions of the first light-transmitting microstructure and the second light-transmitting microstructure are perpendicular to each other. The extending directions of the first light-transmitting microstructure and the second light-transmitting microstructure of the third-stage microstructure lens are perpendicular to each other, which can disperse light in two mutually perpendicular directions, effectively reducing the splicing bright and dark seams generated at the splicing points of the light between adjacent lenses on the lens, improving the uniformity of the overall backlight, and reducing the manufacturing cost.

Description

Technical Field

[0001] The present invention relates to the technical field of backlighting, and particularly to a backlight module and an ultra-thin liquid crystal display. Background Art

[0002] In the automotive electronics industry, TFT (Thin Film Transistor)-LCD (Liquid Crystal Display) is often used as the light source system of HUD (Head Up Display). TFT-LCD is a thin-film field-effect transistor, which is a type of source matrix liquid crystal display and needs to meet requirements such as fast response time and good display quality. General backlight illumination systems cannot meet the needs. The illumination system in the prior art consists of a bracket, a lamp board, a first-level array lens, a diffusion film, and a second-level array lens. It uses the lamp board to provide energy for the entire backlight illumination system. The first-level array lens collects the light of the LED lights on the lamp board. The diffusion film expands and homogenizes the light emitted from the first-level array lens, making the angle of the light larger. The second-level array lens contracts the light expanded by the diffusion plate, so that the angle of the light is controlled within the angle range required by the backlight illumination system.

[0003] The structure of the above entire backlight illumination module is simple, but there are obvious splicing bright and dark seams at the light splicing positions between adjacent lenses. It can be clearly seen that the second-level array lens is honeycomb-shaped. The uniformity of the entire backlight illumination system is poor, affecting the imaging quality, and the light utilization rate is low. In addition, the high cost of the diffusion film also leads to a high cost of the backlight illumination module. Summary of the Invention

[0004] Based on this, it is necessary to provide a backlight module and an ultra-thin liquid crystal display.

[0005] A backlight module includes: a bracket, a lamp board, a first-level light splitting array lens, a second-level collimated light array lens, and a third-level microstructure lens;

[0006] One side of the lamp board is provided with a plurality of light source bodies, and the light source bodies are arranged in an array;

[0007] The lamp board, the first-level light splitting array lens, the second-level collimated light array lens, and the third-level microstructure lens are respectively connected to the bracket, and the first-level light splitting array lens, the second-level collimated light array lens, and the third-level microstructure lens are sequentially arranged along the light-emitting direction of the light source bodies;

[0008] The first-stage splitting array lens includes a first-stage carrier board and a plurality of first-stage lenses. Each of the first-stage lenses is arranged in an array on the side of the first-stage carrier board facing away from the lamp board, and each of the first-stage lenses is convexly provided with a curved surface on the side of the first-stage carrier board facing away from the lamp board. Each of the first-stage lenses is aligned with a light source body;

[0009] The second-stage collimated light array lens includes a second-stage carrier board and a plurality of second-stage lenses. Each of the second-stage lenses is arranged in an array on the side of the second-stage carrier board facing away from the lamp board, and each of the second-stage lenses is convexly provided with a curved surface on the side of the second-stage carrier board facing away from the lamp board. Each of the second-stage lenses is aligned with a first-stage lens, and the width of the second-stage lens is greater than the width of the first-stage lens;

[0010] On the side of the third-stage micro-structured lens facing the lamp board, a first light-transmitting microstructure is provided. On the side of the third-stage micro-structured lens facing away from the lamp board, a second light-transmitting microstructure is provided. The extending direction of the first light-transmitting microstructure and the extending direction of the second light-transmitting microstructure are perpendicular to each other.

[0011] In one embodiment, the width of the first light-transmitting microstructure and the width of the second light-transmitting microstructure are less than the width of the first-stage lens.

[0012] In one embodiment, the shape of the second-stage lens is hemispherical.

[0013] In one embodiment, the shape of the first-stage lens is hemispherical.

[0014] In one embodiment, the materials of the first-stage splitting array lens, the second-stage collimated light array lens, and the third-stage micro-structured lens are any one of PC, PMMA, and glass.

[0015] In one embodiment, the bracket is arranged in a frame structure. An installation cavity is provided inside the bracket. The lamp board is located at one end of the bracket, and the lamp board closes one end of the installation cavity. The first-stage splitting array lens, the second-stage collimated light array lens, and the third-stage micro-structured lens are sequentially arranged in the installation cavity and are respectively connected to the bracket.

[0016] In one embodiment, the shape of the first light-transmitting microstructure includes first light-transmitting strips arranged in multiple columns. Each of the first light-transmitting strips extends along a first direction. The shape of the second light-transmitting microstructure includes second light-transmitting strips arranged in multiple rows. Each of the second light-transmitting strips extends along a second direction. The first direction is perpendicular to the second direction.

[0017] In one embodiment, the cross-sectional shape of each of the first light-transmitting strips is semi-circular or V-shaped, and the cross-sectional shape of each of the second light-transmitting strips is semi-circular or V-shaped.

[0018] In one embodiment, the three-level microstructure lens includes a three-level carrier board, the first light-transmitting microstructure disposed on one side of the three-level carrier board facing the lamp board, and the second light-transmitting microstructure disposed on one side of the three-level carrier board facing away from the lamp board. An accommodation cavity is provided inside the three-level carrier board, and a three-level sub-convex lens is provided in the accommodation cavity. The material of the three-level sub-convex lens is different from that of the three-level carrier board, and the thickness of the three-level sub-convex lens gradually increases from the outside to the middle.

[0019] An ultra-thin liquid crystal display includes the backlight module described in any one of the above embodiments.

[0020] The beneficial effects of the present invention are as follows: The extending directions of the first light-transmitting microstructure and the second light-transmitting microstructure of the three-level microstructure lens are perpendicular to each other, and can disperse light in two mutually perpendicular directions respectively. Moreover, the widths of the first light-transmitting microstructure and the second light-transmitting microstructure are relatively small, which can effectively disperse and diffuse the light of the second-level collimated light array lens, effectively reduce the splicing bright and dark seams generated at the splicing points of the light between adjacent lenses on the first-level light-splitting array lens and the second-level collimated light array lens, improve the uniformity of the overall backlight, and effectively reduce the manufacturing cost because there is no need for a diffusion film. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order 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 drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is a schematic perspective exploded view of a backlight module according to an embodiment;

[0023] Figure 2 It is a schematic view of the light-emitting direction of a backlight module according to an embodiment;

[0024] Figure 3 It is a schematic assembly structure view of the bracket and the lamp board of a backlight module according to an embodiment;

[0025] Figure 4 It is a schematic assembly structure view of the bracket and the first-level light-splitting array lens of a backlight module according to an embodiment;

[0026] Figure 5 It is a schematic assembly structure view of the bracket and the second-level collimated light array lens in one direction of a backlight module according to an embodiment;

[0027] Figure 6Schematic diagram of the assembly structure of the bracket of the backlight module and the secondary collimating light array lens in another direction for an embodiment;

[0028] Figure 7 Schematic diagram of the assembly structure of the bracket of the backlight module and the tertiary microstructure lens for an embodiment;

[0029] Figure 8A Partial structure schematic diagram of the light incident surface of the tertiary microstructure lens for an embodiment;

[0030] Figure 8B Partial structure schematic diagram of the light exiting surface of the tertiary microstructure lens for an embodiment;

[0031] Figure 9 Schematic diagram of the light exiting effect of the existing backlight module without using the tertiary microstructure lens;

[0032] Figure 10 Schematic diagram of the light exiting effect of the backlight module in the embodiment of the present application;

[0033] Figure 11 Cross-sectional structure schematic diagram of the tertiary microstructure lens for an embodiment. Detailed implementation manners

[0034] 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. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] Such as Figure 1As shown, it is a backlight module 10 according to an embodiment of the present invention, including: a bracket 400, a lamp board 500, a first-stage light splitting array lens 100, a second-stage collimated light array lens 200, and a third-stage microstructure lens 300; a plurality of light source bodies 510 are arranged on one side of the lamp board 500, and each of the light source bodies 510 is arranged in an array; the lamp board 500, the first-stage light splitting array lens 100, the second-stage collimated light array lens 200, and the third-stage microstructure lens 300 are respectively connected to the bracket 400, and the first-stage light splitting array lens 100, the second-stage collimated light array lens 200, and the third-stage microstructure lens 300 are sequentially arranged along the light-emitting direction of the light source bodies 510; the first-stage light splitting array lens 100 includes a first-stage carrier plate 110 and a plurality of first-stage lenses 120, each of the first-stage lenses 120 is arranged in an array on the side of the first-stage carrier plate 110 facing away from the lamp board 500, and each of the first-stage lenses 120 is convexly arranged in an arc shape on the side of the first-stage carrier plate 110 facing away from the lamp board 500, and each of the first-stage lenses 120 is aligned with one of the light source bodies 510; the second-stage collimated light array lens includes a second-stage carrier plate 210 and a plurality of second-stage lenses 220, each of the second-stage lenses 220 is arranged in an array on the side of the second-stage carrier plate 210 facing away from the lamp board 500, and each of the second-stage lenses 220 is convexly arranged in an arc shape on the side of the second-stage carrier plate 210 facing away from the lamp board 500, each of the second-stage lenses 220 is aligned with one of the first-stage lenses 120, and the width of the second-stage lens 220 is greater than the width of the first-stage lens 120; a first light-transmitting microstructure is arranged on the side of the third-stage microstructure lens 300 facing the lamp board 500, and a second light-transmitting microstructure is arranged on the side of the third-stage microstructure lens 300 facing away from the lamp board 500, and the extending direction of the first light-transmitting microstructure and the extending direction of the second light-transmitting microstructure are perpendicular to each other.

[0036] In this embodiment, the light source bodies 510 are arranged on the side of the lamp board 500 facing the first-stage light splitting array lens 100. The lamp board 500 is used to support the light source bodies 510 and provide electrical energy for the light source bodies 510. The light source bodies 510 are used to emit light after being powered on. In some embodiments, the light source bodies 510 are LED (light-emitting diode) lamp beads.

[0037] The light board 500, the first-level splitting array lens 100, the second-level collimated light array lens 200, and the third-level microstructure lens 300 are respectively installed on the bracket 400. The first-level splitting array lens 100 is arranged close to the light board 500, and the second-level collimated light array lens 200 and the third-level microstructure lens 300 are sequentially arranged on the side of the first-level splitting array lens 100 away from the light board 500. In this way, the light emitted by the light source body 510 on the light board 500 passes through the first-level splitting array lens 100, the second-level collimated light array lens 200, and the third-level microstructure lens 300 in sequence and is transmitted to the outside.

[0038] In this embodiment, as Figure 2 shown, each first-level lens 120 on the first-level splitting array lens 100 is aligned with a light source body 510, and is used to disperse and diffuse the light of the light source body 510. After being dispersed by the first-level lens 120 of the first-level splitting array lens 100, the light propagates to the second-level collimated light array lens 200. Since the width of the second-level lens 220 on the second-level collimated light array lens 200 is greater than the width of the first-level lens 120, it can further diffuse the light. And since the spherical curvature of the second-level lens 220 is smaller than the spherical curvature of the first-level lens 120, therefore, it can make the light tend to propagate in the direction perpendicular to the second-level carrier plate 210, thereby forming collimated light and making the light incident on the third-level microstructure lens 300 tend to be parallel. Subsequently, the collimated light is transmitted through the third-level microstructure lens 300.

[0039] Specifically, as Figure 2 shown, and in combination with Figure 8A and Figure 8B , the side of the third-level microstructure lens 300 facing the light board 500 is the light incident surface, the side of the third-level microstructure lens 300 facing away from the light board 500 is the light exit surface. The first light-transmitting microstructure on the light incident surface of the third-level microstructure lens 300 diffuses the light angle in the Y-axis direction, and the second light-transmitting microstructure on the light exit surface diffuses the light angle in the X-axis direction, so that the light is diffused in both the X-axis direction and the Y-axis direction, and the light transmitted from the second-level collimated light array lens 200 to the third-level microstructure lens 300 is fully diffused and scattered. Even at the position between adjacent lenses of the second-level collimated light array lens 200, sufficient light propagation can be obtained, thereby weakening the degree of the splicing bright and dark seams generated at the splicing of the light. And compared with the traditional diffusion film, the third-level microstructure lens 300 has a greater thickness, which is more conducive to diffusing the light, so that the light diffused by the third-level microstructure lens 300 is not easy to generate splicing bright and dark seams, improving the uniformity of the overall backlight. And since there is no need for a diffusion film, the manufacturing cost is effectively reduced, and the light-transmitting effect of the third-level microstructure lens 300 is better than that of the diffusion film, effectively improving the backlight brightness.

[0040] In one embodiment, the widths of the first light-transmitting microstructure and the second light-transmitting microstructure are less than the width of the primary lens 120. In this embodiment, the widths of the first light-transmitting microstructure and the second light-transmitting microstructure on the three-stage microstructure lens 300 refer to the widths in the direction perpendicular to the extension directions of the first light-transmitting microstructure and the second light-transmitting microstructure. Since the widths of the first light-transmitting microstructure and the second light-transmitting microstructure are small, light can be effectively diffused, enabling the light to be emitted more evenly. It should be understood that the first light-transmitting microstructure and the second light-transmitting microstructure respectively include a plurality of fine microstructure units. The smaller the width of the microstructure, the more the number of microstructure units. By scattering and diffusing the originally relatively concentrated light through more microstructure units, the light emission can be made more uniform, and the dark areas in the splicing bright and dark seams can be further compensated, thereby making the overall backlight brightness more uniform.

[0041] In order to enable the light of the light source body 510 to be fully diffused, in one embodiment, as Figure 1 shown, the shape of the secondary lens 220 is hemispherical. In one embodiment, one side of the secondary lens 220 is connected to the secondary carrier 210, the side of the secondary lens 220 facing away from the secondary carrier 210 is a convex surface, and the convex surface of the secondary lens 220 is an arc surface. By setting the primary lens 120 as a hemispherical lens with an arc surface, the light of the light source body 510 can be effectively scattered and diffused.

[0042] In order to enable the light of the light source body 510 to be fully diffused, in one embodiment, as Figure 1 shown, the shape of the primary lens 120 is hemispherical. In one embodiment, one side of the primary lens 120 is connected to the primary carrier 110, the side of the primary lens 120 facing away from the primary carrier 110 is a convex surface, and the convex surface of the primary lens 120 is an arc surface. By setting the primary lens 120 as a hemispherical lens with an arc surface, the light of the light source body 510 can be effectively diffused.

[0043] Through the primary lens 120 and the secondary lens 220 with hemispherical or arc surface structures, the light emitted by the light source body 510 of the lamp board 500 can be well received and utilized, improving the utilization rate of light, thereby improving the light emission rate and brightness of the backlight module 10.

[0044] In one embodiment, as Figure 1As shown, the width of the secondary lens 220 is greater than the width of the primary lens 120, and the spherical curvature of the secondary lens 220 is less than the spherical curvature of the primary lens 120. That is to say, compared with the arc surface of the primary lens 120, the bending curvature of the arc surface of the secondary lens 220 is smaller (relatively flatter). In this way, the primary lens 120 can diffuse the light emitted by the light source body 510 at a larger angle, enabling the light to cover a larger area, which is conducive to the uniform diffusion of light. The secondary lens 220 can convert the diffused light into light that is emitted in a parallel manner. Compared with the light emitted diffusely, the light emitted in a parallel manner can better fill the darker areas between the secondary lenses 220, greatly weakening the splicing bright and dark seams, making the light output of the backlight module 10 more uniform and avoiding the appearance of splicing bright and dark seams.

[0045] It should be understood that the larger the size of the lens, the easier it is to diffuse the light to a larger range. Therefore, the fact that the width of the secondary lens 220 is greater than the width of the primary lens 120 is conducive to diffusing the light transmitted by the primary lens 120 to a larger range. And because the arc curvature of the secondary lens 220 is small, the diffused light in a larger range tends to be parallel, which is conducive to reducing the brightness difference between the dark area and the normal brightness area in the splicing bright and dark seams. While the smaller the size of the lens, the easier it is to scatter the light, dispersing the originally converging light and eliminating the splicing bright and dark seams. Therefore, setting the smaller-sized first light-transmitting microstructure and second light-transmitting microstructure on the tertiary lens can effectively scatter the light diffused by the secondary collimating light array lens 200, enabling the light to fill the dark areas, eliminating the splicing bright and dark seams, and making the backlight more uniform.

[0046] In one embodiment, as Figure 1 shown, the distance between the secondary lenses 220 is less than the distance between the primary lenses 120. In this embodiment, the relatively large distance between the primary lenses 120 is conducive to aligning the light source body 510, accurately diffusing the light of each light source body 510, and having a larger diffusion space. While the relatively small distance between the secondary lenses 220 can reduce the area of the dark area and the area of the splicing bright and dark seams. After reducing the area of the splicing bright and dark seams, through the further diffusion of the tertiary microstructure lens 300, the splicing bright and dark seams generated at the light splicing points between the lenses can be significantly eliminated, making the overall light output more uniform.

[0047] In one embodiment, please refer to again Figure 1, the edges of the secondary lenses 220 are interconnected, and the primary lenses 120 are spaced apart from each other. In this embodiment, since the edges of the secondary lenses 220 are interconnected, the thinner regions of the secondary lenses 220 are interconnected. In this way, the distance between the secondary lenses 220 can be reduced, so that the width of the dark seam of the splicing bright and dark seam generated at the light splicing position is reduced, and further, the splicing bright and dark seam generated at the light splicing position between the lenses can be further eliminated, thereby making the overall light output more uniform.

[0048] In order to interconnect the edges of the secondary lenses 220, in one embodiment, the projected shape of the secondary lenses 220 on the secondary carrier 210 is hexagonal. In this way, the edges of adjacent secondary lenses 220 can be closely adjacent to each other in parallel until they coincide, so that the secondary lenses 220 are interconnected with each other. At the same time, the light transmitted through the secondary lenses 220 is in a honeycomb shape, the width of the dark seam of the splicing bright and dark seam is smaller, and the overall light emission is more uniform.

[0049] It should be understood that in the cognition of this field, reducing the distance between the lenses can make the light output more uniform, but it is not that simply reducing the distance between the lenses can eliminate the splicing bright and dark seam. For example, in the primary lenses 120, if the distance between the primary lenses 120 is reduced to be close to (the distance between the primary lenses 120 is too small), the following problems will exist: on the one hand, since there is a one-to-one correspondence between the primary lenses 120 and the light source bodies 510, reducing the distance between the primary lenses 120 means reducing the distance between the light source bodies 510. Increasing the number of light source bodies 510 will result in higher costs and increased energy consumption. The mutual proximity of the light source bodies 510 also causes the heat generation to rise sharply, which is not conducive to improving the service life. On the other hand, if the position of the light source bodies 510 is not adjusted and the distance between the primary lenses 120 is reduced, and the distance between the primary lenses 120 is too small, then because the light source bodies 510 do not correspond to the primary lenses 120, most of the light of the light source bodies 510 is transmitted through the space between the primary lenses 120, resulting in poor light emission effects. In addition, if the distance between the light source bodies 510 and the distance between the primary lenses 120 are both reduced at the same time, the mutually adjacent primary lenses 120 are combined to form a large lens, so that the light source bodies 510 transmit through the primary lenses 120 to form an effect similar to surface light output. However, if the secondary lenses are not adjusted, there will still be splicing bright and dark seams.

[0050] Therefore, it is not appropriate to set the distance of the first-level lens 120 too small, but this conclusion does not apply to the second-level lens 220. Due to the diffusion through the first-level lens 120, the light transmitted from the second-level lens 220 tends to be parallel when exiting. If the distance between the second-level lenses 220 is large, it will result in a relatively large area of the spliced bright and dark seams. Therefore, the edges of the second-level lenses 220 are connected to each other, which can effectively reduce the area of the spliced bright and dark seams. Therefore, in this embodiment, the distance between the first-level lenses 120 is determined according to the position of the light source body 510, that is, the distance between the first-level lenses 120 is not reduced, while the distance between the second-level lenses 220 is reduced until they are connected to each other. This can achieve a better light transmission effect, reduce the area of the spliced bright and dark seams, and at the same time, the cost is lower, the energy consumption is lower, and the service life is longer. And in this case, there is no need to reduce the distance between the light source bodies 510 and the distance between the first-level lenses 120, which can effectively ensure that the spliced bright and dark seams are eliminated at a relatively low cost.

[0051] Therefore, in one embodiment, the width of the second-level lens 220 is greater than the width of the first-level lens 120, and the spherical curvature of the second-level lens 220 is smaller than the spherical curvature of the first-level lens 120. The edges of the second-level lenses 220 are connected to each other, and the first-level lenses 120 are arranged at intervals. The spherical curvature of the first-level lens 120 is larger, that is to say, the surface of the first-level lens 120 is more curved, resulting in a larger diffusion angle, which is beneficial to diffusing the light of the light source body 510. While the spherical curvature of the second-level lens 220 is smaller, that is, the surface of the second-level lens 220 is relatively flatter, making the emitted light tend to be parallel during the diffusion process. In this way, the light transmitted through the second-level lens 220 intersects at a nearly parallel angle at the position between adjacent second-level lenses 220, thus well compensating for the brightness in the relatively dark area. In this way, it is not only beneficial to reduce the brightness difference between the dark area and the normal brightness area in the spliced bright and dark seams, but also can effectively reduce the area of the spliced bright and dark seams. Furthermore, the spliced bright and dark seams can be easily eliminated by the third-level microstructure lens 300.

[0052] Therefore, in this embodiment, the distance between the first-level lenses 120 is greater than or equal to half of the width of one second-level lens 220 and less than the width of one second-level lens 220, and the edges of the second-level lenses 220 are connected to each other, that is, the spacing between the second-level lenses 220 is 0. In this way, the first-level lenses 120 can well split and diffuse the light of the light source body 510, and the second-level lenses 220 change the diffused light into light that tends to be parallel. Moreover, the distance between the second-level lenses 220 is very close, so that the light emitted in parallel can well cover the gap between the second-level lenses 220. Compared with the traditional diffused light, the light emitted in parallel can better fill the darker light-emitting area between the second-level lenses 220, greatly weakening the splicing bright and dark seams. With the further diffusion of the third-level microstructure lens 300, the splicing bright and dark seams generated at the light splicing points between adjacent lenses on the first-level light-splitting array lens 100 and the second-level collimated light array lens 200 can be significantly eliminated, thus making the overall light emission more uniform.

[0053] In one embodiment, the materials of the first-level light-splitting array lens 100, the second-level collimated light array lens, and the third-level microstructure lens 300 are any one of PC, PMMA, and glass.

[0054] In one embodiment, the first-level carrier plate 110 and the first-level lens 120 are integrally formed. In one embodiment, the second-level carrier plate 210 and the second-level lens 220 are integrally formed. In one embodiment, the third-level microstructure lens 300 includes a third-level carrier plate 310, a first light-transmitting microstructure disposed on the side of the third-level carrier plate 310 facing the lamp board 500, and a second light-transmitting microstructure disposed on the side of the third-level carrier plate 310 facing away from the lamp board 500. The third-level carrier plate 310, the first light-transmitting microstructure, and the second light-transmitting microstructure are integrally formed.

[0055] In one embodiment, the materials of the first-level light-splitting array lens 100, the second-level collimated light array lens, and the third-level microstructure lens 300 are PC (Polycarbonate). It is worth mentioning that the array lens made of PC material has the characteristics of stable material properties and stable structure. When the lamp board 500 is working, the lamp board 500 generates a relatively high temperature, and the lens made of PC material can effectively avoid deformation or color change due to temperature change. Especially for the first-level light-splitting array lens 100, since it is close to the lamp board 500, using PC material to make the first-level light-splitting array lens 100 can effectively avoid the change of the surface shape and color caused by the high temperature of the lamp board 500.

[0056] In one embodiment, the materials of the first-stage splitting array lens 100, the second-stage collimated light array lens, and the third-stage microstructure lens 300 are PMMA (Polymethyl Methacrylate, polymethyl methacrylate, acrylic). In one embodiment, the materials of the first-stage splitting array lens 100, the second-stage collimated light array lens, and the third-stage microstructure lens 300 are glass.

[0057] It is worth mentioning that for the third-stage microstructure lens 300 made of PC, PMMA, or glass, the material cost is low, and the process of forming the third-stage microstructure lens 300 using these materials is relatively simple. Therefore, the cost of the third-stage microstructure lens 300 is low, and its comprehensive cost is one-third of that of the traditional diffusion film. This greatly reduces the manufacturing cost of the backlight module 10. Moreover, the third-stage microstructure lens 300 formed using these materials has a stable structure, is not easily damaged, and is easy to assemble.

[0058] In one embodiment, please refer to Figures 3 to 7 , the bracket 400 is arranged in a frame structure, an installation cavity 401 is arranged inside the bracket 400, the lamp board 500 is located at one end of the bracket 400, and the lamp board 500 closes one end of the installation cavity 401. The first-stage splitting array lens 100, the second-stage collimated light array lens 200, and the third-stage microstructure lens 300 are sequentially arranged in the installation cavity 401 and are respectively connected to the bracket 400.

[0059] In this embodiment, the lamp board 500 is located at the first end of the bracket 400, and the lamp board 500 closes the first end of the installation cavity 401. The first-stage splitting array lens 100, the second-stage collimating light array lens 200, and the third-stage microstructure lens 300 are sequentially arranged in the installation cavity 401 along the direction from the end close to the installation cavity 401 to the second end close to the installation cavity 401. The edge of the first-stage splitting array lens 100 is connected to the side wall of the installation cavity 401, the edge of the second-stage collimating light array lens 200 is connected to the side wall of the installation cavity 401, the third-stage microstructure lens 300 is located at the second end of the bracket 400, and closes the second end of the installation cavity 401. Since both the first-stage splitting array lens 100 and the second-stage collimating light array lens 200 are connected to the side wall of the installation cavity 401, the light emitted by the lamp board 500 is transmitted to the third-stage microstructure lens 300 through the first-stage splitting array lens 100 and the second-stage collimating light array lens 200 in sequence, avoiding the light from diffusing to the outside of the bracket 400 and also avoiding the light from emitting from the gap between the first-stage splitting array lens 100 and the bracket 400 and the gap between the second-stage collimating light array lens 200 and the bracket 400. In addition, the third-stage microstructure lens 300 closes the second end of the installation cavity 401, which can ensure that the light is transmitted from the third-stage microstructure lens 300 to the outside, avoiding the light from emitting from the gap between the third-stage microstructure lens 300 and the bracket 400, thereby making the overall light output efficiency higher and the light output more uniform.

[0060] In order to install the lamp board 500, the first-stage splitting array lens 100, the second-stage collimating light array lens 200, and the third-stage microstructure lens 300 on the bracket 400, in one embodiment, as Figure 3 shown, a buckle 410 is convexly provided at the first end of the bracket 400. The buckle 410 abuts against the side of the lamp board 500 facing away from the first-stage splitting array lens 100. The lamp board 500 abuts against the end face of the first end of the bracket 400. The lamp board 500 is pressed tightly on the end face of the first end of the bracket 400 through the buckle, so that the lamp board 500 can be stably installed on the bracket 400. In order to further reinforce the lamp board 500, the lamp board 500 can also be connected to the bracket 400 by screws. In some embodiments, the first-stage splitting array lens 100, the second-stage collimating light array lens 200, and the third-stage microstructure lens 300 can be connected to the bracket 400 by screws, or can be connected to the bracket 400 by using a buckle structure, or can be connected to the bracket 400 by using the cooperation of a plug-in block and a slot, or can be connected by using the cooperation of a plug-in post and a plug-in hole. For example, plug-in holes are provided on the lens array lens, and plug-in posts are convexly provided on the bracket 400, and the plug-in posts are inserted into the plug-in holes. It is worth mentioning that the connection methods of the first-stage splitting array lens 100, the second-stage collimating light array lens 200, and the third-stage microstructure lens 300 with the bracket 400 can be realized by the existing technologies well-known to those skilled in the art, and are not described in detail in this embodiment.

[0061] In order to enable the light transmitted from the three - level microstructure lens to diffuse along the X - direction and Y - direction parallel to the three - level carrier plate and further eliminate the spliced bright and dark seams, in one embodiment, as Figure 8A and Figure 8B shown, the shape of the first light - transmitting microstructure includes first light - transmitting strips 351 arranged in multiple columns, each of the first light - transmitting strips 351 extending along a first direction, the shape of the second light - transmitting microstructure includes second light - transmitting strips 352 arranged in multiple rows, each of the second light - transmitting strips 352 extending along a second direction, and the first direction is perpendicular to the second direction.

[0062] In this embodiment, the first direction and the second direction are two mutually perpendicular directions parallel to the three - level carrier plate. In this embodiment, the first direction is taken as the X - direction and the second direction is taken as the Y - direction. In this way, each of the first light - transmitting strips 351 extends along the X - axis direction and is arranged parallel to each other in the Y - axis direction, and each of the second light - transmitting strips 352 extends along the Y - axis direction and is arranged parallel to each other in the X - axis direction. In this way, the first light - transmitting strips 351 diffuse the light rays in the Y - axis direction, and the second light - transmitting strips 352 diffuse the light rays in the X - axis direction. Since the first light - transmitting strips 351 and the second light - transmitting strips 352 are located on two opposite surfaces of the same three - level carrier plate, the incident light diffuses in the Y - axis, and then the outgoing light diffuses in the X - axis, thereby effectively eliminating the spliced bright and dark seams.

[0063] In one embodiment, the cross - sectional shape of each of the first light - transmitting strips 351 is semi - circular or V - shaped, and the cross - sectional shape of each of the second light - transmitting strips 352 is semi - circular or V - shaped.

[0064] In this embodiment, the cross - sectional shapes of the first light - transmitting strips 351 and the second light - transmitting strips 352 are cylindrical, semi - cylindrical or V - shaped. In this way, the light can diffuse to different directions along the surface of the light - transmitting strips, thereby making the light diffusion effect better.

[0065] It is worth mentioning that in the present application, the first light-transmitting microstructure and the second light-transmitting microstructure belong to microstructures. Therefore, the width or diameter of the microstructure is less than 0.3 mm. In some embodiments, the width or diameter of the microstructure is less than or equal to 0.3 mm and greater than 0.05 mm, that is, the widths of the first light-transmitting strip 351 and the second light-transmitting strip 352 are less than or equal to 0.3 mm and greater than 0.05 mm. It should be understood that within a certain range, the smaller the width of the microstructure, the better the light diffusion effect, and the splicing bright and dark seams can be effectively eliminated. However, the width of the microstructure cannot be too small. If the microstructure is too small, the surface of the three-level microstructure lens tends to be smooth, and a good diffusion effect cannot be formed. Therefore, in this embodiment, the widths of the first light-transmitting strip 351 and the second light-transmitting strip 352 are less than or equal to 0.3 mm and greater than 0.05 mm, which can not only achieve a good diffusion effect but also effectively eliminate the splicing bright and dark seams.

[0066] In one embodiment, the edges of the secondary lenses 220 are connected to each other, and the projected shape of the secondary lenses 220 on the secondary carrier 210 is a hexagon. The shape of the first light-transmitting microstructure includes first light-transmitting strips 351 arranged in multiple columns, and each of the first light-transmitting strips 351 extends along a first direction. The shape of the second light-transmitting microstructure includes second light-transmitting strips 352 arranged in multiple rows, and each of the second light-transmitting strips 352 extends along a second direction. The cross-sectional shape of each of the first light-transmitting strips 351 is a V shape, and the cross-sectional shape of each of the second light-transmitting strips 352 is a V shape.

[0067] In this embodiment, the projected shape of the first light-transmitting strip 351 on a plane perpendicular to the tertiary carrier 310 is a V shape or a triangle, and the projected shape of the second light-transmitting strip 352 on a plane perpendicular to the tertiary carrier 310 is a V shape or a triangle. In this way, the first light-transmitting strip 351 can diffuse light outward in a direction perpendicular to the first direction and inclined to the tertiary carrier 310, and the second light-transmitting strip 352 can diffuse light outward in a direction perpendicular to the second direction and inclined to the tertiary carrier 310. In this way, the light passing through the secondary lens 220 is dispersed by the first light-transmitting strip 351, and the light in the bright and dark areas intersects in the second direction. Subsequently, under the dispersion of the second light-transmitting strip 352, the light in the bright and dark areas intersects in the first direction. After two dispersions and intersections like this, the dark seams between the secondary lenses 220 are sufficiently filled with light, so that the dark seams at the edges of the hexagon are not obvious, and the overall transmitted light is more uniform. As Figure 9 shown, without the diffusion of the first light-transmitting microstructure and the second light-transmitting microstructure, even if a diffusion film is used, it is impossible to well eliminate the dark seams of the hexagon, and the light output brightness is relatively low. As Figure 10As shown, a three - level microstructure lens including a first light - transmitting strip 351 and a second light - transmitting strip 352 is adopted. It can not only effectively eliminate the splicing bright - dark seams, making the overall light output more uniform. In addition, compared with the diffusion film, the three - level microstructure lens has a better light - transmitting effect. Therefore, the light - emitting brightness is higher.

[0068] Please also combine Figure 1 and Figure 2 , the edges of the second - level lenses 220 are connected to each other, the first - level lenses 120 are arranged at intervals from each other, and the distance between the first - level lenses 120 is greater than or equal to one - half of the width of a second - level lens 220 and less than the width of a second - level lens 220. The distance L1 between the first - level carrier 110 and the second - level carrier 210 is 2 to 4.5 times the width D1 of the first - level lens 120. Each first light - transmitting strip 351 extends along the first direction on the first surface of the third - level carrier 310, and each of the second light - transmitting strips 352 extends along the second direction on the second surface of the third - level carrier 310. The distance L2 between the third - level carrier 310 and the second - level carrier 210 is 1.5 to 3.5 times the width D2 of the second - level lens 220.

[0069] It can be seen from Figure 2 that when the light emitted by the light source body passes through the first - level lens 120, the light diffuses in all directions. If the distance L1 between the first - level carrier 110 and the second - level carrier 210 is too small, the diffusion range of the light passing through the first - level lens 120 has not reached the edge of the corresponding second - level lens 220 before passing through the second - level lens 220. In this way, there is not enough light between the second - level lenses 220 to fill, resulting in a relatively obvious dark seam between the second - level lenses 220. If the distance L1 between the first - level carrier 110 and the second - level carrier 210 is too large, on the one hand, it causes the distance between the second - level carrier 210 and the light source body to be too large, affecting the light - emitting brightness. On the other hand, when the light passing through the first - level lens 120 reaches the position of the second - level carrier 210, the diffusion range is large and the light is too scattered, resulting in not enough light between the second - level lenses 220 to fill. In this way, the light passing through the second - level lens 220 will still produce a relatively obvious dark seam. Therefore, in this embodiment, the distance L1 between the first - level carrier 110 and the second - level carrier 210 is set according to the width D1 of the first - level lens 120, and this L1 is 2 to 4.5 times the width D1 of the first - level lens 120. In this way, the diffused light can effectively fill the dark seams between the second - level lenses 220, and effectively avoid the situation that the dark seams between the second - level lenses 220 cannot be filled due to the excessive dispersion of the light of the first - level lens 120, thereby effectively reducing the dark seams between the second - level lenses 220.

[0070] In addition, it is worth mentioning that from Figure 2It can be seen that if the distance L2 between the third-level carrier plate 310 and the second-level carrier plate 210 is too large, it will also cause the distance between the third-level carrier plate 310 and the light source body to be too large, affecting the light output brightness. If the distance L2 between the third-level carrier plate 310 and the second-level carrier plate 210 is too small, that is, the third-level carrier plate 310 is too close to the second-level carrier plate 210, the stripes formed by the light transmission of the first light-transmitting microstructure and the second light-transmitting microstructure will be magnified to a visible level by the naked eye. Although the dark seams generated between the second-level lenses 220 can be eliminated, another kind of stripe will be generated. Therefore, in this embodiment, the distance L2 between the third-level carrier plate 310 and the second-level carrier plate 210 is set according to the width D2 of the second-level lens 220, that is, the distance L2 between the third-level carrier plate 310 and the second-level carrier plate 210 is 1.5 to 3.5 times the width of the width of the second-level lens 220. In this way, not only can the splicing bright and dark seams generated at the light splicing position between the second-level lenses be eliminated, but also the stripes formed by the light transmission of the first light-transmitting microstructure and the second light-transmitting microstructure can be effectively prevented from being magnified. In this case, since the stripes formed by the light transmission of the first light-transmitting microstructure and the second light-transmitting microstructure are extremely thin and cannot be distinguished by the naked eye, a better light output effect is formed. Comparison Figure 9 and Figure 10 It can be seen that for the backlight module using the traditional diffusion film, the light transmitted through the adjacent second-level lenses, such as Figure 9 shown, there are obvious splicing bright and dark seams in the backlight, showing an obvious honeycomb shape. And through the above structure, as Figure 10 shown, on the one hand, since the diffusion film is reduced, the backlight brightness is greater. On the other hand, the light at the center of the honeycomb is diffused, and the dark splicing position at the edge of the honeycomb is effectively filled with light, making the edge dark seams of the honeycomb not obvious, and the light transmitted out is more uniform as a whole, and no visible stripes can be formed, and the light output effect is better.

[0071] In one embodiment, as Figure 11 shown, the third-level microstructure lens 300 includes a third-level carrier plate 310, the first light-transmitting microstructure disposed on the side of the third-level carrier plate 310 facing the lamp board 500, and the second light-transmitting microstructure disposed on the side of the third-level carrier plate 310 facing away from the lamp board 500. An accommodation cavity is provided inside the third-level carrier plate, and a third-level sub-convex lens 320 is provided in the accommodation cavity. The material of the third-level sub-convex lens 320 is different from that of the third-level carrier plate 310, and the thickness of the third-level sub-convex lens 320 gradually increases from the outside to the middle.

[0072] In this embodiment, the material of the third-level carrier plate 310 is PMMA, and the material of the third-level sub-convex lens 320 is glass. There are different refractive indices between glass and PMMA. Since the thickness of the third-level sub-convex lens 320 gradually increases from the outside to the middle, that is, the thickness in the middle of the third-level sub-convex lens 320 is larger and the thickness at the edge is smaller, in this way, a light-gathering effect can be achieved. In this embodiment, the shape of the first light-transmitting microstructure includes first light-transmitting strips 351 arranged in multiple columns, each of the first light-transmitting strips 351 extends along the first direction, the shape of the second light-transmitting microstructure includes second light-transmitting strips 352 arranged in multiple rows, each of the second light-transmitting strips 352 extends along the second direction, the cross-sectional shape of each of the first light-transmitting strips 351 is V-shaped, the cross-sectional shape of each of the second light-transmitting strips 352 is V-shaped, and a third-level sub-convex lens is arranged inside the third-level carrier plate. It should be understood that the functions of the first light-transmitting strips 351 and the second light-transmitting strips 352 are to diffuse light and make the light rays intersect, so as to supplement the light at the dark seams, eliminate the spliced bright and dark seams, and make the overall light output more uniform. By arranging the third-level sub-convex lens inside the third-level carrier plate, a light-gathering effect can be achieved, and the light diverged due to the diffusion effect of the first light-transmitting strips 351 and the second light-transmitting strips 352 can be well compensated, so as to achieve a light-gathering effect and thus improve the brightness. Compared with the diffusion film, the overall light output brightness is improved. It should be understood that if additional lenses are added for light-gathering, the overall thickness of the backlight module will be increased, and to a certain extent, it will also block light, and the brightness cannot be significantly improved. In this embodiment, arranging the third-level sub-convex lens 320 inside the third-level carrier plate 310 will not only not increase the thickness of the backlight module additionally, but also effectively improve the light output brightness without blocking light.

[0073] In one embodiment, the width or diameter of the first light-transmitting strip 351 is less than or equal to 0.2 mm and greater than 0.1 mm, and the width or diameter of the second light-transmitting strip 352 is less than or equal to 0.1 mm and greater than 0.05 mm. For example, the width or diameter of the first light-transmitting strip 351 is 0.2 mm, and the width or diameter of the second light-transmitting strip 352 is 0.05 mm. In this embodiment, the width of the first light-transmitting strip 351 is greater than that of the second light-transmitting strip 352. Since the first light-transmitting strip 351 is closer to the light source, the larger size of the first light-transmitting strip 351 is beneficial to the large-range diffusion of light. And even though the size of the first light-transmitting strip 351 is large, because the light transmitted by it still needs to be diffused by the third-stage carrier plate 310, the third-stage sub-convex lens 320, and the second light-transmitting strip 352, the stripes formed by the transmission due to the large size of the first light-transmitting strip 351 can be effectively reduced. For the second light-transmitting strip 352, since it is located on the outermost side, it needs to be set smaller so that the formed stripes are smaller and more blurred, making the light transmitted through the second light-transmitting strip 352 emit in a surface shape and without obvious stripe shape, making the backlight more uniform. In this way, on the one hand, the light-emitting effect can be better, and on the other hand, since the precision requirement for processing the first light-transmitting strip 351 is reduced, the production cost can be further reduced.

[0074] In one embodiment, there is provided an ultra-thin liquid crystal display including the backlight module described in any of the above embodiments.

[0075] In this embodiment, through the sequential light splitting and diffusion of the first-stage light splitting array lens, the second-stage collimated light array lens, and the third-stage micro-structured lens, the backlight can be made more uniform and the backlight effect can be better. Among them, the extending directions of the first light-transmitting micro-structure and the second light-transmitting micro-structure of the third-stage micro-structured lens are perpendicular to each other, which can scatter the light in two mutually perpendicular directions, and the widths of the first light-transmitting micro-structure and the second light-transmitting micro-structure are small, which can effectively scatter and diffuse the light of the second-stage collimated light array lens, effectively reducing the splicing bright and dark seams generated at the splicing points of the adjacent lenses on the first-stage light splitting array lens and the second-stage collimated light array lens, improving the uniformity of the overall backlight, and since there is no need for a diffusion film, the manufacturing cost is effectively reduced and the backlight brightness is increased. In addition, the structure of the third-stage micro-structured lens can effectively reduce the distance between the third-stage micro-structured lens and the second-stage collimated light array lens, thereby reducing the overall thickness of the backlight module, and thus reducing the overall thickness of the liquid crystal display to form an ultra-thin liquid crystal display.

[0076] In the above embodiments, the primary splitting lens receives and distributes the light emitted by the LED lamp, enabling efficient utilization of the light emitted by the LED lamp and evenly hitting within the range of the secondary collimating lens. The secondary collimating lens then converts the light into collimated light and emits it onto the tertiary micro-structured lens. The tertiary micro-structured lens further projects the collimated light into different light angles required in the X and Y directions, such that the angles of the light are controlled within the angle range required by the backlight illumination system. The tertiary micro-structured lens not only ensures the light output angles (about 25° in the X direction and about 15° in the Y direction), enabling the brightness uniformity to be maintained when the eyes move left and right or up and down, but also greatly weakens the obviousness of the splicing bright and dark seams between the lamps, improving the virtual image uniformity of the backlight illumination system. This structure is simple, low in cost, with less light energy loss, and ensures the light uniformity and high imaging quality.

[0077] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as falling within the scope described in this specification.

[0078] The above-described embodiments merely represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A backlight module, characterized in that: include: A bracket, a light board, a primary light splitting array lens, a secondary collimating light array lens and a tertiary microstructure lens; and the backlight module does not include a diffusion film; A plurality of light sources are arranged on one side of the light board, and each of the light sources is arranged in an array; The light board, the primary light splitting array lens, the secondary collimating light array lens and the tertiary microstructure lens are respectively connected to the bracket, and the primary light splitting array lens, the secondary collimating light array lens and the tertiary microstructure lens are respectively arranged in sequence along the light emitting direction of the light source body; The primary light splitting array lens comprises a primary carrier and a plurality of primary lenses, each of the primary lenses is arranged in an array on a side of the primary carrier facing away from the light board, and each of the primary lenses is arranged in an arc-shaped convex shape on a side of the primary carrier facing away from the light board, and each of the primary lenses is aligned with one of the light sources; The secondary collimating light array lens comprises a secondary carrier and a plurality of secondary lenses, each of the secondary lenses is arranged in an array on a side of the secondary carrier facing away from the light board, and each of the secondary lenses is arranged in an arc-surface convex on a side of the secondary carrier facing away from the light board, each of the secondary lenses is aligned with a primary lens, and the width of the secondary lens is greater than the width of the primary lens; The first light-transmitting microstructure is disposed on one side of the three-level microstructure lens facing the light board, and the second light-transmitting microstructure is disposed on one side of the three-level microstructure lens facing away from the light board, and the extension direction of the first light-transmitting microstructure and the extension direction of the second light-transmitting microstructure are perpendicular to each other; The three-level microstructure lens includes a three-level carrier, the first light-transmitting microstructure arranged on a side of the three-level carrier facing the light board, and the second light-transmitting microstructure arranged on a side of the three-level carrier facing away from the light board. The three-level carrier is provided with a receiving cavity inside, and a three-level sub-convex mirror is arranged in the receiving cavity. The material of the three-level sub-convex mirror is different from that of the three-level carrier, and the thickness of the three-level sub-convex mirror gradually increases from the outside to the middle. The shape of the first light-transmitting microstructure includes first light-transmitting strips arranged in multiple columns, each of which extends along a first direction. The shape of the second light-transmitting microstructure includes second light-transmitting strips arranged in multiple rows, each of which extends along a second direction. The first direction is perpendicular to the second direction.

2. The backlight module according to claim 1, characterized in that: The width of the first light-transmitting microstructure and the width of the second light-transmitting microstructure are smaller than the width of the primary lens.

3. The backlight module according to claim 1, characterized in that: The secondary lens is hemispherical in shape.

4. The backlight module according to claim 1, characterized in that: The shape of the primary lens is hemispherical.

5. The backlight module according to claim 1, characterized in that: The material of the primary light splitting array lens, the secondary collimating light array lens and the tertiary microstructure lens is any one of PC, PMMA and glass.

6. The backlight module according to claim 1, characterized in that: The bracket is configured as a frame structure, a mounting cavity is configured inside the bracket, the light board is located at one end of the bracket, and the light board closes one end of the mounting cavity, the first-level spectroscopic array lens, the second-level collimating light array lens and the third-level microstructure lens are sequentially configured in the mounting cavity and are respectively connected to the bracket.

7. The backlight module according to any one of claims 1 to 6, characterized in that: The width of the secondary lens is greater than that of the primary lens, and the spherical curvature of the secondary lens is smaller than that of the primary lens.

8. The backlight module according to claim 7, characterized in that: The cross-sectional shape of each of the first light-transmitting strips is semicircular or V-shaped, and the cross-sectional shape of each of the second light-transmitting strips is semicircular or V-shaped.

9. An ultra-thin liquid crystal display, characterized in that: The invention comprises the backlight module described in any one of claims 1 to 8.

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