Diffusion plate and direct type backlight module
By setting a microlens structure on the diffusion plate outward surface of the Mini LED backlight solution, the light-mixed halo problem in the transition area of the light and dark area is solved, the display effect is improved, and the halo reduction effect is achieved without increasing the cost.
Patent Information
- Application Number
- CN202421901883.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-08-07
AI Technical Summary
The existing Mini LED backlight solution is prone to produce mixed halos in the light and dark transition areas, affecting the display effect. In this area, traditional diffusion plates will cause side effects, resulting in serious halo problems.
A diffusion plate is designed, and its light-extruded surface includes at least two light-emitting regions. A first microlens is provided with an overlapping region of each adjacent light-emitting region. The light emitted by the LED lamp beads is diverged after being incident on the microlens through the diffusion plate to reduce the light intensity between the light-emitting regions.
By setting up a microlens structure on the diffusion plate outward surface, the halo is effectively reduced, the display effect is improved, and the material cost is almost not increased, which solves the problem of the contradiction between diaphragm cost and picture taste.
Smart Images
Figure CN222927159U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of display, and particularly relates to a diffusion plate and a direct - type backlight module. Background Art
[0002] In the existing Mini LED (sub - millimeter light - emitting diode) backlight solution, the Local dimming technology is adopted. In the light and dark transition area, at the edge of the position where the light overlaps, due to the sudden reinforcement of light, light mixing halos are likely to occur, affecting the display effect. Moreover, as the number of partitions increases and the light mixing distance decreases, the halos become more serious. The advantage of the traditional diffusion plate in homogenizing the backlight will cause side effects in the light and dark transition area of the Mini LED backlight solution. There are various methods in the industry to solve the halos, such as increasing the number of partitions, using optical lenses for light condensation, optimizing the partition light control algorithm, etc., but they will inevitably bring about an increase in cost or a decline in the display effect. Summary of the Utility Model
[0003] In view of this, the purpose of the utility model is to provide a diffusion plate and a direct - type backlight module, which are used to solve the technical problem that light mixing halos are likely to occur at the edge of the position where the light overlaps due to the sudden reinforcement of light, affecting the display effect.
[0004] To solve the above - mentioned technical problem, the utility model provides a diffusion plate. The light - emitting surface of the diffusion plate includes at least two light - emitting regions; the light - emitting regions correspond one - to - one with the LED lamp beads on one side of the light - incident surface of the diffusion plate;
[0005] A first microlens is arranged in the overlapping region of adjacent light - emitting regions; the light emitted by the LED lamp beads is incident on the first microlens through the diffusion plate, and then is emitted after being diverged by the first microlens.
[0006] Optionally, the diffusion plate includes a substrate; a diffusion coating is arranged on the light - incident surface of the substrate; the light - emitting surface of the substrate serves as the light - emitting surface of the diffusion plate.
[0007] Optionally, a second microlens is arranged in the middle region of each light - emitting region; the middle region is the vertical projection region of the LED lamp bead on the light - emitting region; the light emitted by the LED lamp beads is incident on the second microlens through the diffusion plate, and then is emitted after being diverged by the second microlens.
[0008] Optionally, a third microlens is arranged in the first transition region of each light - emitting region; the first transition region is the spaced - apart region between the overlapping region and the middle region; the light emitted by the LED lamp beads is incident on the third microlens through the diffusion plate, and then is emitted after being converged by the third microlens.
[0009] Optionally, the first microlens is disposed in the edge region of the outermost light-emitting region; the edge region is the region of the outermost light-emitting region close to the edge of the diffusion plate.
[0010] The third microlens is disposed in the second transition region of the outermost light-emitting region; the second transition region is the spaced region between the edge region and the intermediate region.
[0011] Optionally, the particle size of the first microlens is smaller than that of the third microlens.
[0012] The particle size of the second microlens is smaller than that of the third microlens.
[0013] Optionally, the overlapping region and the edge region are both provided with a first microlens array, and the first microlens array includes at least two of the first microlenses.
[0014] The intermediate region is provided with a second microlens array, and the second microlens array includes at least two of the second microlenses.
[0015] The first transition region and the second transition region are both provided with a third microlens array, and the third microlens array includes at least two of the third microlenses.
[0016] Optionally, a UV transparent coating is provided on the light-emitting surface of the diffusion plate; the first microlens, the third microlens and the second microlens are formed by embossing the UV transparent coating in a periodic arrangement.
[0017] Optionally, the thickness of the UV transparent coating is 35 μm - 50 μm, including both end values.
[0018] To solve the above technical problems, the present invention also provides a direct-lit backlight module, including: a back plate and a diffusion plate arranged in sequence along the thickness direction; at least two LED beads are arranged on the surface of the back plate close to the diffusion plate; the diffusion plate includes the diffusion plate as described above.
[0019] Optionally, a reflective film is provided on the surface of the back plate close to the diffusion plate; at least two of the LED beads are arranged on the surface of the reflective film close to the diffusion plate.
[0020] It can be seen that a diffusion plate provided by the present utility model has an outgoing light surface including at least two light-emitting regions; the light-emitting regions correspond one by one to the LED lamp beads on one side of the incoming light surface of the diffusion plate; a first microlens is arranged in the overlapping region between adjacent light-emitting regions; the light emitted by the LED lamp beads is incident on the first microlens through the diffusion plate, and then is emitted after being diverged by the first microlens. By arranging microlenses in the overlapping regions between each adjacent light-emitting region on the outgoing light surface of the diffusion plate, the light emitted by the LED lamp beads is first dispersed evenly by the diffusion plate, and then the light in the overlapping regions is scattered by the microlens structure on the outgoing light surface, reducing the light intensity between the light-emitting regions and achieving the purpose of reducing halos. The present utility model also provides a direct-lit backlight module, which improves the halo problem of the display-zone backlight module through a specially designed diffusion plate. Without substantially increasing the material cost, the light path at the four peripheral edges of the backlight is optimized, improving the picture quality and solving the contradiction between the cost of the film and the picture quality. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model 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 described below are only the embodiments of the present utility model, and those of ordinary skill in the art can also obtain other drawings according to the provided drawings without creative efforts.
[0022] Figure 1 FIG. is a schematic structural diagram of a direct-lit backlight module provided by an embodiment of the present utility model;
[0023] Figure 2 FIG. is a schematic structural diagram of a single zone of a direct-lit backlight module provided by an embodiment of the present utility model.
[0024] The description of the reference numerals is as follows:
[0025] 1 - LED lamp bead; 2 - UV transparent coating; 3 - substrate; 4 - back plate; 5 - reflective film. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only some of the embodiments of the present utility model, rather than all of them. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present utility model belong to the scope of protection of the present utility model.
[0027] With the development of display technology and the miniaturization of LED chips, the Local dimming backlight solution with thousands of partitions has emerged as the times require. However, when displaying a picture with a strong transition between light and dark, due to the larger number of backlight sources of Mini LED and more complex light control, there may be a certain halo phenomenon when using full-array backlight. Especially in the case of a dark background, this halo phenomenon may be more obvious. As one of the core components, the diffusion plate of the direct-lit backlight can homogenize the light emitted by the backlight beads, preventing the light from concentrating in one area, thus making the brightness of the entire screen uniform. However, the advantage of homogenizing the backlight of the traditional diffusion plate will cause side effects in the light and dark transition area of the Mini LED backlight solution. There are various methods in the industry to solve the halo, such as increasing the number of partitions, using optical lenses for light concentration, optimizing the partition light control algorithm, etc., but they will inevitably bring about an increase in cost or a decline in the display effect.
[0028] Therefore, the present utility model provides a diffusion plate. By arranging microlenses in the overlapping area of adjacent light-emitting areas on the light-emitting surface of the diffusion plate, the technical problem that light mixing halos are likely to occur at the edges of the overlapping positions of light due to the sudden reinforcement of light, affecting the display effect, is solved.
[0029] Please refer to Figure 1 and Figure 2 , Figure 1 which is a schematic structural diagram of a direct-lit backlight module provided by an embodiment of the present utility model; Figure 2 which is a schematic structural diagram of a single partition of a direct-lit backlight module provided by an embodiment of the present utility model. A diffusion plate provided by an embodiment of the present utility model, the backlight surface of the diffusion plate includes at least two light-emitting areas; the light-emitting areas correspond one by one to the LED beads 1 on one side of the light-incident surface of the diffusion plate;
[0030] A first microlens is arranged in the overlapping area of adjacent light-emitting areas; the light emitted by the LED bead 1 is incident on the first microlens through the diffusion plate and then emitted after being diverged by the first microlens.
[0031] The specific type of the diffusion plate in this embodiment is not limited, as long as it can homogenize the light emitted by the LED bead 1. For example, the diffusion plate may include a substrate 3; a diffusion coating is provided on the light-incident surface of the substrate 3; the light-emitting surface of the substrate 3 is used as the light-emitting surface of the diffusion plate. The specific material of the substrate 3 in this embodiment is not limited. For example, the substrate 3 may be a PS substrate, a glass substrate, or an MS substrate, etc. Among them, the PS substrate is prepared from PS (polystyrene) material, and the PS material is a colorless and transparent thermoplastic plastic; the MS substrate is prepared from MS (polymethylsiloxane) material, and the MS material is an organosilicon polymer material. It should be noted that the PS material and the MS material are existing materials, and this embodiment directly uses the substrates prepared from the above materials without improving the material components.
[0032] Further, in order to improve the uniformity of the light on the light-emitting surface and reduce the halo, a second microlens may be provided in the middle region of each light-emitting area in this embodiment; the middle region is the vertical projection area of the LED lamp bead 1 on the light-emitting area; the light emitted by the LED lamp bead 1 is incident on the second microlens through the diffuser plate and then emitted after being diverged by the second microlens. It should be noted that in this embodiment, by providing microlenses in each area of the light-emitting surface of the diffuser plate facing the LED lamp bead 1, the light emitted by the LED lamp bead 1 is first dispersed evenly by the diffuser plate, and then the light in the area facing the LED lamp bead 1 is scattered by the microlens structure on the light-emitting surface, reducing the brightness directly above the LED lamp bead 1, improving the uniformity of the light on the light-emitting surface, and reducing the halo.
[0033] Further, in order to improve the uniformity of the light on the light-emitting surface and reduce the halo, a third microlens may be provided in the first transition area of each light-emitting area in this embodiment; the first transition area is the spaced area between the overlapping area and the middle area; the light emitted by the LED lamp bead 1 is incident on the third microlens through the diffuser plate and then emitted after being converged by the third microlens. It should be noted that in this embodiment, by providing microlenses in each transition area of the light-emitting surface of the diffuser plate, the light emitted by the LED lamp bead 1 is first dispersed evenly by the diffuser plate, and then the light in the transition area is focused by the microlens structure on the light-emitting surface, increasing the brightness of the front transition area, improving the uniformity of the light on the light-emitting surface, and reducing the halo.
[0034] Further, a first microlens may be provided in the edge area of the outermost light-emitting area in this embodiment; the edge area is the area of the outermost light-emitting area close to the edge of the diffuser plate; a third microlens is provided in the second transition area of the outermost light-emitting area; the second transition area is the spaced area between the edge area and the middle area. It should be noted that only one side of the outermost light-emitting area of the diffuser plate has an overlapping area with the adjacent light-emitting area, and there is no overlapping area on the side close to the diffusion edge. In this embodiment, by providing different microlenses in different areas of the outermost light-emitting area, the uniformity of the light in the outermost light-emitting area can be further improved.
[0035] It should be noted that in this embodiment, a first microlens is provided in the overlapping area of adjacent light-emitting areas, a second microlens is provided in the middle area of each light-emitting area, a third microlens is provided in the first transition area of each light-emitting area, and at the same time, a first microlens is provided in the edge area of the outermost light-emitting area and a third microlens is provided in the second transition area, which can form as Figure 1The microlens structure with the light-emitting area as the period is shown. The microlens structure includes several periodic lenses, and the law of the period corresponds one-to-one with the LED lamp beads 1 and the light-emitting area. By introducing a regular microlens structure on the light-emitting surface of the diffusion plate, the light is first dispersed evenly by the diffusion plate, and then the light distribution of each light-emitting area is modulated by the regular microlens structure on the light-emitting surface, so as to achieve the purpose of eliminating the halo.
[0036] It should be noted that if the particle size of the microlens is small, the curvature is large, and correspondingly, the incident light can be scattered, so that the light is emitted after divergence; if the particle size of the microlens is large, the curvature is small, and correspondingly, the incident light can be converged, so that the light is emitted after convergence. In this embodiment, the specific sizes of the first microlens, the second microlens, and the third microlens are not limited, as long as it is ensured that the first microlens and the second microlens can make the light diverge and then be emitted, and the third microlens can make the light converge and then be emitted. For example, the particle size of the first microlens can be smaller than that of the third microlens; the particle size of the second microlens can be smaller than that of the third microlens.
[0037] In this embodiment, the specific numbers of the first microlens, the second microlens, and the third microlens are not limited. For example, the overlapping area and the edge area can both be provided with a first microlens array, and the first microlens array includes at least two first microlenses; the middle area can be provided with a second microlens array, and the second microlens array includes at least two second microlenses; the first transition area and the second transition area can both be provided with a third microlens array, and the third microlens array includes at least two third microlenses. It should be noted that in this embodiment, multiple microlenses are provided in each area. By adjusting the number and size of the microlenses, the effect of light divergence or convergence can be adjusted more flexibly.
[0038] In this embodiment, the specific type of the microlens is not limited, as long as it can ensure that the light can be diverged or converged. For example, a UV (Ultraviolet) transparent coating 2 can be provided on the light-emitting surface of the diffusion plate; the first microlens, the third microlens, and the second microlens are formed by imprinting the UV transparent coating 2 in a periodic arrangement.
[0039] In this embodiment, the specific thickness of the UV transparent coating 2 is not limited. For example, the thickness of the UV transparent coating 2 can be 35μm - 50μm, including both end values.
[0040] Based on the above embodiment, the utility model sets microlenses in the overlapping area of each adjacent light-emitting area on the light-emitting surface of the diffusion plate. The light emitted by the LED lamp beads is first dispersed evenly by the diffusion plate, and then the light in the overlapping area is scattered by the microlens structure on the light-emitting surface, reducing the light intensity between the light-emitting areas, so as to achieve the purpose of reducing the halo.
[0041] Please refer to Figure 1 andFigure 2 , Figure 1 This is a schematic structural diagram of a direct - type backlight module provided by an embodiment of the present utility model; Figure 2 This is a schematic structural diagram of a single partition of a direct - type backlight module provided by an embodiment of the present utility model. A direct - type backlight module provided by an embodiment of the present utility model includes: a back plate 4 and a diffusion plate arranged in sequence along the thickness direction; at least two LED lamp beads 1 are arranged on one surface of the back plate 4 close to the diffusion plate; the diffusion plate includes the diffusion plate as described above.
[0042] The specific structure of the diffusion plate in this embodiment is not limited, and the embodiment of the diffusion plate above can be referred to, which will not be elaborated here.
[0043] Furthermore, in order to reduce light energy loss and improve the light use efficiency, a reflective film 5 can be arranged on one surface of the back plate 4 close to the diffusion plate in this embodiment; at least two LED lamp beads 1 are arranged on one surface of the reflective film 5 close to the diffusion plate.
[0044] Based on the above - mentioned embodiment, the present utility model improves the halo problem of the display partition backlight module through a specially designed diffusion plate. Without substantially increasing the material cost, the light path at the four - week edge of the backlight is optimized to improve the picture quality. The light path and the effect of improving the quality can be simulated by software, and corresponding results can be seen during the development stage, solving the contradiction problem between the cost of the film and the picture quality.
[0045] In order to make the present utility model easier to understand, the working principles of the diffusion plate and the direct - type backlight module provided by the embodiments of the present utility model will be described in detail below with specific examples.
[0046] As Figure 1 shown in the direct - type backlight module, the direct - type backlight module includes: a back plate 4, a reflective film 5 and a diffusion plate arranged in sequence along the thickness direction; at least two LED lamp beads 1 are arranged on one surface of the reflective film 5 close to the diffusion plate; the diffusion plate includes a substrate 3, a diffusion coating is arranged on the light - incident surface of the substrate 3, and a regular UV transparent coating 2 (i.e., a regular microlens structure imprinted by the UV transparent coating 2) is coated on the light - emitting surface of the substrate 3. The microlens structure includes a variety of microlenses with different particle sizes arranged in a periodic pattern, and each group of microlenses corresponds to the position and the light - emitting area of the LED lamp bead 1. The microlens structure of each light - emitting area is as Figure 2 shown, in area A, the first microlenses with smaller size and larger curvature are coated; in area B, the third microlenses with larger size and smaller curvature are coated; in area C, the second microlenses with smaller size and larger curvature are coated.
[0047] When Figure 2When it is the outermost light-emitting area, taking the rightmost light-emitting area as an example, the A area on the left represents the overlapping area (the overlapping area between this light-emitting area and the adjacent light-emitting area on the left); the B area on the left represents the first transition area (the interval area between the overlapping area and the middle area); the C area represents the middle area (the vertical projection area of the LED lamp bead 1 on the light-emitting area), the B area on the right represents the second transition area (the interval area between the edge area and the middle area); the A area on the right represents the edge area (the area of this light-emitting area close to the edge of the diffusion plate). When Figure 2 When it is a non-outermost light-emitting area, the A area on the left represents the overlapping area (the overlapping area between this light-emitting area and the adjacent light-emitting area on the left); the B area on the left represents the first transition area (the interval area between the overlapping area and the middle area); the C area represents the middle area (the vertical projection area of the LED lamp bead 1 on the light-emitting area), the B area on the right represents the first transition area (the interval area between the overlapping area and the middle area); the A area on the right represents the overlapping area (the overlapping area between this light-emitting area and the adjacent light-emitting area on the right).
[0048] As Figure 2 shown, the light rays emitted by the LED lamp bead 1 are homogenized in the diffusion plate. The upper surface of the UV transparent coating 2 is provided with an imprinted microlens structure. Among them, the first microlens with a smaller particle size in the A area can disperse the light rays, reduce the light intensity between the light-emitting areas, and reduce the halo; the third microlens with a larger particle size in the B area can converge the light rays and increase the brightness of the front transition area; the second microlens with a smaller particle size in the C area can disperse the light rays, reduce the brightness directly above the LED lamp bead 1, and improve the uniformity of the light rays on the light-emitting surface.
[0049] Applying the diffusion plate and the direct-lit backlight module provided by the embodiments of the present invention, by introducing a regular microlens structure on the light-emitting surface of the diffusion plate, the light rays are first dispersed and homogenized by the diffusion coating on the light-incident surface of the diffusion plate, and then the light distribution of each light-emitting area is modulated by the regular microlens structure on the light-emitting surface, and the light rays emitted by the diffusion plate are regularly diffused along each light-emitting area, so as to achieve the purpose of eliminating the halo.
[0050] The above has introduced in detail a diffusion plate and a direct-lit backlight module provided by the present invention. For those of ordinary skill in the art, according to the idea of the embodiments of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.
Claims
1. A diffuser plate, characterized in that: The light emitting surface of the diffusion plate includes at least two light emitting areas; the light emitting areas correspond one to one with the LED lamp beads on one side of the light incident surface of the diffusion plate; A first microlens is provided in the overlapping area of the adjacent light-emitting areas; the light emitted by the LED lamp bead is incident on the first microlens via the diffusion plate, and then diverges through the first microlens before being emitted.
2. The diffuser plate according to claim 1, characterized in that: The diffusion plate comprises a substrate; a diffusion coating is arranged on the light incident surface of the substrate; and a light emitting surface of the substrate serves as the light emitting surface of the diffusion plate.
3. The diffuser plate according to claim 1 or 2, characterized in that: A second microlens is provided in the middle area of each light-emitting area; the middle area is the vertical projection area of the LED lamp bead on the light-emitting area; the light emitted by the LED lamp bead is incident on the second microlens through the diffusion plate, and then diverges through the second microlens and then exits.
4. The diffuser plate according to claim 3, characterized in that: A third microlens is provided in the first transition area of each light-emitting area; the first transition area is the interval area between the overlapping area and the middle area; the light emitted by the LED lamp bead is incident on the third microlens through the diffusion plate, and then converged by the third microlens before being emitted.
5. The diffuser plate according to claim 4, characterized in that: The first microlens is disposed in the edge area of the outermost light-emitting area; the edge area is the area of the outermost light-emitting area close to the edge of the diffusion plate; The third microlens is disposed in the second transition region of the outermost light emitting region; the second transition region is a spacing region between the edge region and the middle region.
6. The diffuser plate according to claim 5, characterized in that: The particle size of the first microlens is smaller than the particle size of the third microlens; The particle size of the second microlens is smaller than that of the third microlens.
7. The diffuser plate according to claim 5, characterized in that: The overlapping area and the edge area are both provided with a first microlens array, and the first microlens array includes at least two first microlenses; The middle area is provided with a second microlens array, and the second microlens array includes at least two second microlenses; The first transition region and the second transition region are both provided with a third microlens array, and the third microlens array includes at least two third microlenses.
8. The diffuser plate according to claim 5, characterized in that: The light-emitting surface of the diffusion plate is provided with a UV transparent coating; the UV transparent coating is embossed to form the first microlenses, the third microlenses and the second microlenses which are periodically arranged.
9. The diffuser plate according to claim 8, characterized in that: The thickness of the UV transparent coating is 35 μm to 50 μm, both inclusive.
10. A direct-type backlight module, characterized in that: include: A back plate and a diffuser plate are sequentially arranged along the thickness direction; At least two LED lamp beads are arranged on a surface of one side of the back plate close to the diffusion plate; The diffuser plate comprises the diffuser plate according to any one of claims 1 to 9.
11. The direct-type backlight module according to claim 10, characterized in that: A reflective film is arranged on one side of the back plate near the diffuser plate; and at least two LED lamp beads are arranged on one side of the reflective film near the diffuser plate.