Light guide plate and light emitting module

Abstract

The invention provides a light guide plate and a light-emitting module, the light guide plate comprises a light-emitting surface, a backlight surface and a light-incident surface, the light-emitting surface and the backlight surface are oppositely arranged along the thickness direction of the light guide plate, the light-incident surface is connected with the light-emitting surface and the backlight surface, the light-emitting surface is provided with a lattice point area provided with lattice points, and the lattice points are arranged along a first direction from the middle to two sides of the lattice point area. The lattice point area proportion per unit area is gradually increased, so that the lattice point proportion per unit area in the middle area is small, and the light emitting amount is reduced; the light intensity of the positions on the two sides is weak, the lattice point proportion is large, the light emitting amount is increased, the dynamic compensation effect of emitting light from the middle less and emitting light from the two sides more is formed, and therefore the local difference between the bright middle and the dark two sides is eliminated, and the brightness uniformity of the whole light emitting face is greatly improved.

Description

Technical Field

[0001] This application relates to the field of light guide technology, and in particular to a light guide plate and a light emission module. Background Technology

[0002] A light guide plate is an optical element that can transform a point light source or a line light source into a uniform surface light source. Its core function is to control the light propagation path through dot design to achieve uniform light diffusion.

[0003] However, in order to reduce costs, the use of light-emitting components is generally minimized in related technologies. But reducing the number of light-emitting components will affect the overall uniformity of light output. Summary of the Invention

[0004] This application provides a light guide plate and a light emission module to improve the problem that the reduction of light-emitting components in related technologies will affect the overall light emission uniformity.

[0005] In a first aspect, a light guide plate is provided, including a light emitting surface, a backlight surface, and a light incident surface. The light emitting surface and the backlight surface are arranged opposite to each other along the thickness direction of the light guide plate. The light incident surface connects the light emitting surface and the backlight surface. The light emitting surface has a dotted area with halftone dots. Along a first direction and from the middle of the halftone area to both sides, the proportion of halftone dotted area per unit area gradually increases. Wherein, the first direction is the extension direction of the light-incident surface.

[0006] The light guide plate of this application embodiment gradually increases the proportion of dot area per unit area along the first direction from the middle to both sides of the dot area, so that the proportion of dot area per unit area in the middle area is small, reducing the amount of light emitted; while the light intensity on both sides is weaker, the proportion of dot area is large, increasing the amount of light emitted, forming a dynamic compensation effect of "less light emitted in the middle and more light emitted on both sides", thereby eliminating the local difference of bright in the middle and dark on both sides, and greatly improving the brightness uniformity of the entire light-emitting surface.

[0007] Furthermore, traditional light guide plates rely on reducing LED spacing and increasing the number of LEDs to compensate for insufficient uniformity, while this design achieves uniform light output without relying on dense LEDs through a gradient dot pattern. This means that while maintaining the same uniformity, the spacing between LEDs can be significantly increased, reducing the number of LEDs used (e.g., from the traditional 4 to 2), directly lowering the light source procurement cost and aligning with the low-cost design goal.

[0008] In some embodiments, the number of dots per unit area gradually increases along the first direction and from the center to both sides of the dot area.

[0009] In the above embodiments, for a dual-LED large-pitch layout, the light intensity in the central overlapping area is high. By increasing the spacing, the number of dots is controlled, reducing the light output. Conversely, the light intensity in the individual areas on either side is weak. By decreasing the spacing, the number of dots is increased, improving the light output. Throughout this process, the trigger frequency of dot scattering is determined solely by the number and spacing, making it difficult for localized glare due to size variations ("excessive scattering from a single dot"). After uniform scattering by multiple dots, the brightness uniformity of the light-emitting surface is significantly improved, effectively solving the problem of "bright spots in the center and dark areas on both sides" in large-pitch LED layouts. Simultaneously, the dense and uniformly distributed dots allow for a more consistent light emission angle within the light guide plate, avoiding chaotic light direction caused by size differences. This results in a softer light texture and a more comfortable visual experience across the entire emitting surface.

[0010] In some embodiments, along the first direction and from the middle to both sides of the dot area, the spacing between two adjacent dots gradually decreases.

[0011] In the above embodiment, this design of "gradually decreasing spacing from the middle to the sides" perfectly matches the light intensity gradient: the larger spacing in the middle area results in fewer dots per unit area, reducing the amount of light emitted and preventing excessively high light intensity in the middle from creating glaring bright spots; the smaller spacing on the sides results in more dots per unit area, increasing the amount of light emitted and compensating for the light intensity gap in the area covered by a single lamp. The entire process achieves a dynamic balance of "higher light intensity, sparser dots; lower light intensity, denser dots," making the light output distribution along the first direction more uniform. This effectively solves the core problem of "bright in the middle and dark on the sides" in traditional large-spacing layouts. Combined with the dot gradient design in the parallel direction of the light guide plate, it can greatly improve the brightness uniformity of the light-emitting surface. At the same time, the continuous gradient of the spacing ensures that the dot distribution has no abrupt changes, and the light emission intensity transitions smoothly, making it difficult for brightness steps caused by abrupt changes in dot density to occur, resulting in a softer and more natural visual effect.

[0012] In some embodiments, the radii of the dots are equal.

[0013] In the above embodiments, the size of each dot is uniform, and the emission angle and intensity of light after being scattered by the dots are highly consistent, making it difficult to have the problem of "excessive brightness in local areas of large dots"; the light distribution per unit area is more gradual, and when combined with a light-diffusing film, the brightness uniformity of the entire board can be greatly improved, effectively solving the problem of "bright in the middle and dark on both sides" in the dual-LED layout.

[0014] In some embodiments, the minimum distance between two adjacent dots in the first direction is h1, where h1 satisfies: 0.3mm ≤ h1 ≤ 0.4mm; and / or, The maximum distance between two adjacent dots in the first direction is h2, and h2 satisfies: 0.9mm≤h2≤1.0mm.

[0015] In the above embodiments, the value range of h1 is limited to 0.3mm to 0.4mm, which ensures that the density of halftone dots on both sides is sufficient to compensate for the light intensity of a single light source, while avoiding the risk of halftone dot overlap caused by excessive spacing; the value range of h2 is limited to 0.9mm to 1.0mm, which ensures that the halftone dots in the middle are sufficiently sparse to control the amount of light emitted, while avoiding the problem of insufficient halftone dots in the middle area and uncontrolled light propagation caused by excessive spacing.

[0016] In some embodiments, the light guide plate has an opposing surface opposite to the light incident surface, and the proportion of the dot area per unit area gradually increases along a second direction, wherein the second direction is perpendicular to the first direction and points from the light incident surface to the opposing surface.

[0017] In the above embodiment, the design of gradually increasing dot area ratio per unit area along the second direction complements the light intensity attenuation trend: near the light-incident surface, the light intensity is at its peak, and the dot area ratio is the smallest, reducing premature light emission and avoiding glaring bright spots at the near end; as it extends towards the opposite surface, the light intensity gradually decreases, and the dot area ratio increases simultaneously. By increasing the density of scattering points, the total internal reflection condition is maximized, increasing the light output in the far-end region. This dynamic control mode of "less light output at the near end and more light output at the far end" can effectively offset the attenuation gradient of light along the propagation direction. Combined with the dot distribution design perpendicular to the light propagation direction (first direction), such as gradually decreasing the spacing between adjacent dots along the first direction and from the middle to both sides of the dot area, the uniformity of light output from the light guide plate can be improved, effectively solving the technical problem of "excessive brightness at the near end and dimness at the far end" in traditional large-pitch LED layouts. Meanwhile, the gradual change in the proportion of outlets is continuous and smooth, without any brightness steps caused by sudden changes in proportion. The light emission is softer and the visual experience is more comfortable.

[0018] In some embodiments, the light guide plate has an opposing surface opposite to the light incident surface, and the spacing between two adjacent dots gradually decreases along a second direction, wherein the second direction is perpendicular to the first direction and points from the light incident surface to the opposing surface.

[0019] In the above embodiment, by gradually reducing the spacing, the number of dots per unit area increases continuously from the incident surface to the opposing surface, thereby achieving a linear increase in the dot ratio, which can well match the light attenuation law.

[0020] Furthermore, it does not affect the scattering characteristics of individual dots. Because all dots are the same size and shape, the light-destruction efficiency and emission angle of each scattering point are highly uniform, making it difficult to experience the problem of "excessive local scattering" caused by differences in dot size. After light is scattered by dense and uniform dots, the angular distribution of the emitted light is more consistent, resulting in softer light texture without glare or speckles. This makes it particularly suitable for scenarios with stringent visual comfort requirements, such as automotive backlighting and smart wearable displays. In some embodiments, the light guide plate has a facing surface opposite to the light incident surface, and the facing surface is provided with a plurality of arched portions, which are spaced apart along the extending direction of the facing surface.

[0021] In the above embodiments, by setting the arched portion, the light escape loss on the opposing surface can be effectively reduced, thereby improving the overall light energy utilization rate of the light guide plate. Under the same LED power, the emitted light brightness is significantly improved; conversely, under the same brightness requirement, the LED power can be reduced, achieving energy-saving design. The arched section, while reflecting light, can also distribute the light evenly to various areas at the end through the directional reflection of the inclined surface. This allows for adjustment of the reflected light density to address differences in light intensity at different locations at the end, ensuring that areas with weaker light receive more reflected light. Combined with the aforementioned dot gradient design on the backlight surface, the uniformity of the light-emitting surface can be improved.

[0022] By arranging multiple arched sections at intervals along the extension direction of the opposing surface, the entire width of the opposing surface can be covered. This arrangement can intercept light rays propagating from the incident surface to the end as much as possible, reducing light leakage areas and making it suitable for narrow-bezel light guide plates.

[0023] In some embodiments, the backlight surface is recessed into the light-emitting surface to form the dots.

[0024] In the above embodiments, by setting the dots as blind aperture dots, and the inner wall of the recessed blind aperture dots having an arc-shaped sloping structure, light will undergo diffuse reflection when it comes into contact with the inner wall, rather than specular reflection. The angular distribution of the emitted light is wider and more uniform, making it difficult to have the localized highlight concentration problem that may occur with raised dots. For scenarios with strict requirements for visual comfort, such as in-vehicle central control screens and mobile phone displays, recessed dots can effectively avoid glare, pitting, and other adverse phenomena, ensuring the brightness uniformity of the light guide plate and making the light texture closer to natural light.

[0025] The recessed halftone dots on the backlight surface have a high degree of overall flatness, and the bonding with the white reflector is a surface contact, which can minimize light leakage caused by bonding gaps. Light that is not scattered by the halftone dots is conducted to the backlight surface, and is efficiently reflected back into the light guide plate by the reflector, where it participates in the scattering and emission process of the halftone dots again, which can improve the secondary utilization rate of light energy and significantly reduce light energy loss.

[0026] Secondly, a light-emitting module is provided, comprising: The light guide plate mentioned above; and, Multiple light-emitting elements are disposed on the side of the light-incident surface away from the light guide plate and are spaced apart along the first direction. Attached Figure Description

[0027] Figure 1 This is a partial structural schematic diagram of the vehicle headlight module provided in the embodiments of this application; Figure 2 yes Figure 1 A structural diagram of the structure shown from another perspective; Figure 3 yes Figure 2 An enlarged schematic diagram of the structure at point A in the shown structure; Figure 4 yes Figure 2 An enlarged schematic diagram of the structure at point B in the shown structure; Figure 5 yes Figure 2 An enlarged schematic diagram of the structure at point C in the diagram; Figure 6 This is a schematic diagram of the structure of the vehicle headlight module provided in the embodiments of this application.

[0028] Explanation of reference numerals in the attached figures: 100. Light emitting module; 1. Light guide plate; 1a. Light emitting surface; 1b. Backlight surface; 1c. Light incident surface; 1d. Opposing surface; 10. Outlets; 20. Arched section; 2. Light-emitting component; 3. White support component; 4. Circuit board; 5. Diffuser film; 6. Black light-shielding component; 7. Outer lens.

[0029] X, the first direction; Y, the second direction. Detailed Implementation

[0030] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0031] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0032] A light guide plate is an optical element that can transform a point light source or a line light source into a uniform surface light source. Its core function is to control the light propagation path through dot design to achieve uniform light diffusion.

[0033] However, in the existing technology, in order to reduce costs, the use of light-emitting components is generally minimized, but the reduction of light-emitting components will affect the overall uniformity of light output.

[0034] To resolve the above issues, please refer to [link / reference]. Figures 1 to 3 This application provides a light-emitting module 100, which includes a light guide plate 1 and multiple light-emitting elements 2.

[0035] The light guide plate 1 includes a light emitting surface 1a, a backlight surface 1b, and a light incident surface 1c. The light emitting surface 1a and the backlight surface 1b are arranged opposite to each other along the thickness direction of the light guide plate 1. The light incident surface 1c connects the light emitting surface 1a and the backlight surface 1b. The backlight surface 1b has a dotted area with dots 10. Along the first direction X and from the middle of the dotted area to both sides, the area ratio of dots 10 per unit area gradually increases. The first direction X is the extension direction of the light incident surface 1c.

[0036] In this embodiment, the multiple light-emitting elements are multiple light-emitting units, which are disposed on the light-incident side end face of the light guide plate 1, i.e., the light-incident surface 1c, for injecting light into the interior of the light guide plate 1.

[0037] Starting from the light-incident side of the light-emitting element (also known as LED), the light propagates in the light guide plate 1 in a direction perpendicular to the light-incident side. This direction is the parallel light propagation direction, and the direction perpendicular to this direction is the perpendicular light propagation direction, which is the first direction X or the extension direction of the light-incident surface 1c.

[0038] After light enters the light guide plate 1 from the light incident surface 1c, the light intensity is relatively higher in the middle position of the dot area in the first direction X. This is because the light in this area is more likely to converge the direct light incident from the light incident surface 1c, and the light density of the total internal reflection propagation is large.

[0039] By gradually increasing the area ratio of halftone dots 10 per unit area along the first direction X from the center to both sides of the halftone area, the proportion of halftone dots 10 per unit area in the middle area is small, reducing the amount of light emitted; while the light intensity on both sides is weaker, and the proportion of halftone dots 10 is large, increasing the amount of light emitted, forming a dynamic compensation effect of "less light emitted in the middle and more light emitted on both sides", thereby eliminating the local difference of "bright in the middle and dark on both sides" and greatly improving the brightness uniformity of the entire light-emitting surface 1a.

[0040] Furthermore, traditional light guide plates 1 require reducing the LED spacing and increasing the number of LEDs to compensate for insufficient uniformity, while this design achieves uniform light output without relying on dense LEDs through a gradient arrangement of 10 dots. This means that while maintaining the same uniformity, the spacing between LEDs can be significantly increased, reducing the number of LEDs used (e.g., from the traditional 4 to 2), directly reducing the light source procurement cost and aligning with the low-cost design goal.

[0041] When the number of LEDs is reduced to two, it is understandable that the area along the first direction X, from the middle to both sides of the dot area, can be divided into three regions: a central superposition area, a transition area, and a single-sided coverage area. In the central superposition area, the light intensity is highest, covering the superposition range of the light from two LEDs. In the transition area, which is between the superposition area and the single-sided area, the light intensity is moderate. In the single-sided coverage area, the light intensity is lowest, covering only the light from a single LED. However, through the design in this application, the area ratio of the dot 10 per unit area gradually increases along the first direction X, from the middle to both sides of the dot area. Thus, in the intermediate overlay zone, the low percentage of dot area 10 per unit area reduces the amount of light emitted, avoiding the problem of "overly bright center." Simultaneously, the sparse dot area 10 ensures light propagates to both sides, providing sufficient luminous flux to the distant areas. In the transition zone, the moderate percentage of dot area 10 per unit area serves to "smoothly transition brightness," eliminating brightness abrupt changes between the intermediate overlay zone and the single-sided zone, and avoiding obvious bright-dark boundaries. In the single-sided coverage zone, only a single LED provides light coverage, resulting in the weakest light intensity. The high percentage of dot area 10 per unit area maximizes the destruction of total internal reflection, increasing the amount of light emitted and ensuring that the brightness of the single-sided zone is consistent with the intermediate overlay zone, thus addressing the problem of "darker sides."

[0042] In this embodiment, the traditional uniform arrangement method is abandoned, and a differentiated arrangement is carried out according to the light intensity gradient of the parallel light propagation direction; at the same position in the parallel light propagation direction, the density and size of the vertical dots 10 change with the position to compensate for the light intensity difference in this direction and avoid the problem of "bright in the middle and dark at the edge" or local light spots.

[0043] In this embodiment, the light propagation path of the light guide plate 1 is as follows: The light emitted by the light-emitting element enters the interior of the light guide plate 1 from the light incident surface 1c. Due to the difference in refractive index between the light guide plate 1 and the air, the light undergoes total internal reflection in the dotless area and propagates a long distance within the light guide plate 1 along the parallel light propagation direction.

[0044] When light propagates to the dot 10 on the back surface 1b of the light guide plate 1, the structure of the dot 10 changes the interface of the light propagation medium, destroys the total internal reflection condition, and the light changes from the total internal reflection state to the refraction state, and is emitted in the direction of the light emitting surface 1a of the light guide plate 1.

[0045] By differentiating the X-axis non-uniform dot 10 in the first direction, the amount of light emitted can be precisely controlled. The amount of light emitted is reduced in areas with strong light and increased in areas with weak light, thus ensuring the uniformity of the emitted light from the source.

[0046] It is also important to understand that the unit area can be a 3mm*3mm area on the backlight surface 1b.

[0047] Following the above, as the area ratio of dots 10 per unit area gradually increases along the first direction X from the center to both sides of the dot region, the distribution of dots 10 has three forms as follows: 1. Only increase the number of outlets per unit area by 10 (density increase) 2. Increase the area of ​​a single grid point 10 only (the number remains the same, but the size is enlarged). 3. Increased number of outlets + larger individual area (two-way improvement) In the first form, increasing the number of dots 10 essentially means uniformly increasing the density of light scattering points per unit area. In the direction perpendicular to the light propagation (first direction X), the distribution of scattering points can be perfectly matched to the light intensity gradient through arithmetic or Gaussian distributions of spacing. For a dual-LED large-pitch layout, the light intensity is high in the central overlapping area; increasing the spacing controls the number of dots 10, reducing the light output. The light intensity is weak in the single-sided areas on both sides; decreasing the spacing increases the number of dots 10, improving the light output. Throughout the process, the trigger frequency of dot 10 scattering is determined only by the number and spacing, making it difficult for excessive glare from a single dot 10 due to size changes. After uniform scattering by multiple dots 10, the brightness uniformity of the light-emitting surface 1a can be greatly improved, effectively solving the problem of "bright spots in the middle and dark areas on both sides" in large-pitch LED layouts. Meanwhile, the dense and evenly distributed dots 10 can make the light emission angle within the light guide plate 1 more consistent, avoiding the chaotic light emission direction caused by size differences, making the light texture of the entire light-emitting surface softer and the visual experience more comfortable.

[0048] Furthermore, by relying solely on increasing density through sheer numbers, the number of dots 10 becomes a single core variable for controlling light output. In the vertical direction of a dual-LED layout, the gradient increase in the number of dots 10 from the center to the sides perfectly matches the gradient attenuation of the combined light intensity of the two LEDs. This achieves precise control: "the higher the light intensity, the fewer dots 10; the lower the light intensity, the more dots 10." This ensures a strict negative correlation between the light output distribution and the light intensity distribution of the entire light guide plate 1, ultimately achieving brightness balance. This single-variable control mode not only improves design accuracy but also makes the solution highly replicable, allowing for rapid adaptation to light guide plates 1 of different sizes and LED layouts with different spacing.

[0049] In the second form, the diameter of a single dot 10 is enlarged to increase its proportion, and the spacing between the dots 10 is consistent throughout, making it more suitable for areas with moderate light intensity attenuation.

[0050] The larger area of ​​a single dot 10 results in higher efficiency in breaking total internal reflection of light. After light comes into contact with the dot 10, it can be emitted without multiple reflections, reducing the light energy loss inside the light guide plate 1. In the single-sided coverage area of ​​the dual LED (where the light intensity is weakest), the large-size dot 10 can quickly increase the amount of light emitted.

[0051] The large-size halftone dots 10 have a more concentrated light emission range, which can be precisely matched with the light-transmitting area of ​​the mask; in scenarios where specific patterns need to be illuminated, the edges of the patterns will not be blurred due to an excessive number of halftone dots 10, thus improving the display effect of backlit products.

[0052] In the third form, by adjusting the spacing and enlarging the diameter in both directions, the proportion of the total area of ​​the dot matrix 10 per unit area can be increased several times, which can effectively solve the problem of extremely weak light in the far-end single-sided area of ​​the light guide plate 1 (which is far from the LED and has no double lamp superposition) and can effectively compensate for the uniformity of the light surface 1a.

[0053] The dual increase in the number and size of the dots maximizes the probability of disrupting total internal reflection and improves light emission efficiency. Under the same LED power, the light guide plate 1 has higher light output brightness, which can reduce the number of layers of the light uniform film (such as from double layer to single layer), further reducing material costs.

[0054] In the transition zone between the overlapping area in the middle of the dual LEDs and the single-sided areas on both sides, the bidirectional enhancement of the dot 10 design can achieve a smooth gradient in proportion, making it difficult for brightness steps caused by abrupt changes in quantity or size, resulting in a more natural visual effect across the entire panel.

[0055] Furthermore, the radii of the dots 10 are equal, meaning that the size of each dot 10 is uniform. The emission angle and intensity of light after being scattered by the dots 10 are highly consistent, making it difficult for the problem of "local overbrightness of large dots 10" to occur. The light distribution per unit area is more gradual. When combined with a light-diffusing film, the brightness uniformity of the entire board can be greatly improved, effectively solving the problem of "bright in the middle and dark on both sides" in the dual-LED layout.

[0056] In the Gaussian-like distribution gradient of light in the vertical direction (first direction X), the smooth adjustment of the spacing can achieve a seamless transition of "sparse in the middle and dense on both sides" without brightness abrupt changes.

[0057] For dot 10, whether laser dotting or injection molding, the processing path for dot 10 with uniform size is simpler. For example, laser dotting only requires adjusting the dot spacing, eliminating the need for frequent power switching; the cavity size of the injection mold is consistent, resulting in uniform wear during processing and a longer mold life; this is especially suitable for large-scale mass production, greatly improving product yield. With uniform dot 10 size, the shrinkage rate of the light guide plate 1 is uniform during injection molding, preventing warping of the plate surface due to local differences in dot 10 size; this advantage is even more pronounced for thin light guide plates 1, avoiding the impact of deformation on the bonding accuracy with LEDs and light-diffusing films.

[0058] The uniform size of the dots 10 facilitates automated visual inspection, which can quickly identify defective products such as missing dots and wrong dots; if uniformity needs to be optimized, only the spacing parameters need to be adjusted, without the need to remake the mold or modify the laser power parameters, thus improving the efficiency of R&D iteration.

[0059] In some embodiments, along the first direction X and from the middle to both sides of the dot area, the spacing between two adjacent dots 10 gradually decreases.

[0060] In a dual-LED layout, the central area of ​​the dot matrix region is where the light from two LEDs overlaps, reaching peak intensity across the entire panel. As the light extends to both sides, the coverage gradually transitions from dual-LED to single-LED coverage, with the intensity decreasing linearly. This design, where the spacing gradually decreases from the center to the sides, perfectly matches the intensity gradient: a larger spacing in the central area results in fewer dots per unit area, reducing light output and preventing excessively high intensity in the center from creating glaring bright spots; conversely, a smaller spacing on the sides results in more dots per unit area, increasing light output and compensating for the intensity gap in the single-LED coverage area. This process achieves a dynamic balance where "higher intensity corresponds to sparser dots and lower intensity to denser dots," making the light output distribution along the first direction X more uniform. This effectively solves the problem of brighter centers and darker sides in traditional large-pitch layouts. Combined with the gradient dot matrix design of the light guide plate 1 along the first direction X, it significantly improves the brightness uniformity of the light-emitting surface 1a. Meanwhile, the continuous gradual change in spacing ensures that the distribution of dots 10 is not abrupt, and the intensity of light emission is smoothly transitioned, making it difficult for brightness steps to occur due to abrupt changes in the density of dots 10, resulting in a softer and more natural visual effect.

[0061] The larger dot spacing 10 in the central area reduces premature light scattering in the central superposition zone, allowing more light to propagate to the weaker light areas on both sides via total internal reflection within the light guide plate 1, thus avoiding light energy waste in the central area. Conversely, the smaller dot spacing 10 in the side areas maximizes the disruption of total internal reflection, fully scattering the light propagating to the sides and improving the light extraction efficiency in the weaker light areas. This design achieves precise light energy distribution with "central light guide and side light extraction," significantly improving light energy utilization compared to traditional uniform spacing designs. With the same LED power, this design can output higher brightness; conversely, with the same brightness requirement, LED power can be further reduced, achieving energy-saving design for the product.

[0062] It is also understandable that the design with gradually varying spacing and uniform dot size 10 provides strong compatibility with mainstream mass production processes of light guide plate 1, such as laser dotting and injection molding. In the laser dotting process, the equipment only needs to continuously adjust the dot spacing along the first direction X, without switching key parameters such as laser power and focusing focal length. The dot path planning is simpler, which can shorten the processing time of a single light guide plate 1. At the same time, the fixed dot size 10 keeps the laser spot parameters stable, avoiding defects such as uneven dot size and missing dots caused by frequent spot adjustments, thus improving product yield.

[0063] In one embodiment, in the first direction X, the minimum distance between two adjacent dots 10 is h1, where h1 satisfies: 0.3mm≤h1≤0.4mm, and the maximum distance between two adjacent dots 10 in the first direction X is h2, where h2 satisfies: 0.9mm≤h2≤1.0mm.

[0064] The value of h1 is limited to 0.3mm to 0.4mm, which ensures that the density of the dots 10 on both sides is sufficient to compensate for the light intensity of a single light source, while avoiding the risk of dot overlap caused by excessive spacing. The value of h2 is limited to 0.9mm to 1.0mm, which ensures that the dots 10 in the middle are sufficiently sparse to control the amount of light output, while avoiding the problem of insufficient number of dots 10 in the middle area and uncontrolled light propagation caused by excessive spacing. The preferred values ​​of 0.335mm and 0.9mm are the optimal balance points verified by a large number of optical simulations and actual tests, which can stably output a highly uniform light output effect under different light guide plate sizes and different LED powers.

[0065] It is understandable that the core light intensity characteristic of the dual-LED wide-pitch layout is that the light from the two lights in the middle area is superimposed, and the light intensity reaches the peak of the entire panel; as it extends to both sides, the light gradually turns into single-lamp coverage, and the light intensity decreases symmetrically and linearly. The symmetrical arithmetic sequence of dot spacing in this design perfectly matches the light intensity gradient with a negative correlation: the middle position uses the optimal maximum value h2=0.9mm, which is the area with the largest dot spacing of 10 in the entire first direction X. The number of 10 dots per unit area is the smallest, which can minimize the amount of light emitted in the middle superposition area and avoid the formation of glaring bright spots due to excessive light intensity. When transitioning to both sides, the dot spacing of 10 decreases smoothly from 0.9mm to 0.7mm in an arithmetic sequence, and the number of 10 dots per unit area increases synchronously. The amount of light emitted increases linearly, achieving a stepless brightness transition from the middle bright area to the two side transition areas. When reaching the edge areas on both sides, the dot spacing of 10 drops to the optimal minimum value h1=0.335mm, and the number of 10 dots per unit area reaches the peak. This can maximize the destruction of the total internal reflection condition and fully scatter the light propagating to both sides, accurately making up for the light intensity gap in the single lamp coverage area. This symmetrical arrangement, characterized by "sparse in the middle, dense on both sides, and smooth transition," effectively solves the problem of "bright spots in the middle and dark areas on both sides" in traditional large-pitch LED layouts. Combined with the gradient design of the dot 10 parallel to the direction of light propagation on the light guide plate 1, it can effectively ensure the uniformity of light output from the light-emitting surface 1a.

[0066] The dot spacing arrangement of this design not only improves brightness uniformity but also maximizes the optimization of light propagation paths, reducing light loss within the light guide plate 1. The large spacing design (h2=0.9mm) in the middle area reduces premature scattering of light in the central superposition area, allowing more light to propagate to the weaker light areas on both sides through total internal reflection within the light guide plate 1, avoiding light energy waste in the middle area. As the light transitions to both sides, the spacing gradually decreases, and the number of dots 10 gradually increases, gradually scattering the light propagating to the transition area and achieving uniform light energy distribution. At the edge areas on both sides, the spacing drops to the minimum value (h1=0.335mm), and the number of dots 10 reaches its peak, maximizing the disruption of total internal reflection conditions and fully scattering the light propagating to both sides, improving the light extraction efficiency in the weak light areas. This precise light energy distribution mode of "central light guide, uniform light distribution in the transition area, and light extraction on both sides" improves light energy utilization compared to traditional uniform spacing designs. With the same LED power, this design can output higher brightness; conversely, with the same brightness requirement, the LED power can be further reduced to achieve energy-saving design of the product, which meets the current demand for low-power products in the consumer electronics and automotive fields.

[0067] To further improve the light emission uniformity of the entire light guide plate 1, please refer to one embodiment of this application. Figure 1 as well as Figure 2The light guide plate 1 has an opposing surface 1d opposite to the light incident surface 1c. Along the second direction Y, the area ratio of the dot 10 per unit area gradually increases. The second direction Y is perpendicular to the first direction X and points from the light incident surface 1c to the opposing surface 1d.

[0068] After light enters the light guide plate 1 from the incident surface 1c, it propagates along the second direction Y towards the opposing surface 1d in the form of total internal reflection. During this process, the light energy is linearly attenuated due to factors such as absorption by the light guide plate 1 material and interface scattering. The closer to the opposing surface 1d, the weaker the light intensity. In this embodiment, the design of gradually increasing area ratio of the dot 10 per unit area along the second direction Y precisely complements this light intensity attenuation trend: near the incident surface 1c, the light intensity is at its peak, and the proportion of dot 10 per unit area is the smallest, which can reduce premature light emission and avoid dazzling bright spots at the near end; as it extends towards the opposing surface 1d, the light intensity gradually attenuates, and the proportion of dot 10 per unit area increases simultaneously. By increasing the density of scattering points, the total internal reflection condition is maximized, increasing the amount of light emitted from the far end. This dynamic control mode of "less light emission near the end and more light emission far the end" effectively counteracts the attenuation gradient of light along the propagation direction. Combined with the design of the distributed dots 10 perpendicular to the light propagation direction (first direction X), such as the gradual decrease in the spacing between adjacent dots 10 along the first direction X from the center to both sides of the dot area, the uniformity of light emission from the light guide plate 1 can be improved, effectively solving the technical problem of "excessive brightness near the end and dimness far the end" in traditional large-pitch LED layouts. At the same time, the gradual change in the proportion of dots 10 is continuous and smooth, without brightness steps caused by abrupt changes in proportion, resulting in a softer light emission and a more comfortable visual experience.

[0069] In this embodiment, the light energy is efficiently distributed within the light guide plate 1 by gradient control of the dot ratio 10. The low-percentage dot ratio 10 near the light-incident surface 1c avoids excessively intercepting propagating light, ensuring that most light energy is transmitted to the far end via total internal reflection, thus preventing waste of near-end light energy. Conversely, the high-percentage dot ratio 10 near the opposing surface 1d can fully scatter the residual light energy transmitted to the far end, maximizing the light energy potential of the light guide plate 1. Compared to the traditional uniform dot ratio 10 design, this improves light energy utilization, enabling higher output brightness with the same LED power. Conversely, for the same brightness requirements, the LED power specifications can be further reduced, or the LED spacing can be increased from the traditional 11mm to over 33mm, directly reducing the cost of the light source. This efficient light energy utilization characteristic is particularly important for dual-LED large-pitch layouts, effectively compensating for insufficient far-end light intensity caused by large spacing, ensuring full-panel brightness without the need to increase the number of LEDs.

[0070] It is understandable that, along the second direction Y, the gradually increasing proportion of the area of ​​the network point 10 per unit area also takes the following three forms: 1. Only increase the number of dots per unit area by 10 (increase density, keep size the same). 2. Increase the area of ​​a single grid point 10 only (the number remains the same, but the size is enlarged). 3. Increased number of outlets + larger individual area (two-way improvement) In the first configuration, along the second direction Y from the incident surface 1c to the opposing surface 1d, the spacing of the dots 10 decreases linearly in an arithmetic progression, resulting in uniformly denser scattering points per unit area. Furthermore, the size of each dot 10 remains consistent throughout, ensuring no difference in scattering intensity. In the incident surface 1c region, where the light intensity peaks, the large spacing and small number of dots reduce premature light emission and prevent near-end bright spots. In the opposing surface 1d region, where the light intensity decreases, the small spacing and large number of dots improve scattering efficiency and compensate for the far-end dark areas. Throughout the process, after being scattered by the dense and uniform dots 10, the emitted light intensity exhibits a smooth linear transition, making it difficult for glare problems caused by localized excessive light emission due to differences in the size of individual dots 10 to occur. Combined with the design of the dot 10 distributed perpendicular to the light propagation direction (first direction X), such as gradually decreasing the spacing between adjacent dots 10 along the first direction X from the center to both sides of the dot area, the uniformity of light emission from the light guide plate 1 can be improved. Meanwhile, the uniform scattering points make the light angle more consistent, and the light quality is closer to natural light, making it suitable for scenarios with high requirements for visual comfort, such as automotive backlighting and smart wearable displays.

[0071] In the second approach, along the second direction Y from the incident surface 1c to the opposing surface 1d, the number of dots 10 per unit area remains constant throughout, with only the diameter of each dot 10 gradually increasing, resulting in minimal process adjustments. In laser dotting, there is no need to replan the dotting path; only the laser spot size needs to be linearly adjusted along the second direction Y, shortening equipment setup time. In injection molding, only the diameter parameters of the mold cavity need to be modified, without adjusting the cavity spacing, reducing mold modification costs. Furthermore, the reduced process steps decrease human error, further improving production efficiency.

[0072] The larger the area of ​​a single dot 10, the stronger its ability to disrupt total internal reflection. Larger dots 10 can cover a larger light propagation cross-section, allowing light to exit directly without multiple reflections after contact with the dots 10, reducing light energy loss within the light guide plate 1. In the opposing surface 1d region of the second direction Y, the magnified dots 10 can quickly scatter and emit residual light energy transmitted to the far end, improving light extraction efficiency. This high light efficiency characteristic is suitable for medium-sized light guide plates 1 in scenarios with moderate light attenuation, achieving uniform light extraction without relying on dense dots 10.

[0073] On the other hand, the fixed number of dots 10 allows for a more regular arrangement of the dots, enabling precise matching with the translucent pattern of the mask. For example, in backlit scenarios for characters and icons, the larger dots 10 provide a more concentrated light emission range, preventing blurring of pattern edges due to an excessive number of dots 10, thus improving the clarity and recognizability of the luminous pattern. Simultaneously, designers can flexibly adjust the magnification ratio of local dots 10 according to pattern requirements, such as appropriately enlarging the size of dots 10 in the edge area of ​​icons to enhance edge light emission and make the pattern outline clearer.

[0074] In the third configuration, along the second direction Y, from the incident surface 1c to the opposing surface 1d, the spacing of the dot 10 decreases linearly while the diameter of each dot increases simultaneously. This dual-dimensional superposition results in a significantly greater increase in the total area ratio of the dot 10 compared to the single configuration. For example, within a 3mm × 3mm unit area, the dot 10 spacing on the incident surface 1c is 0.6mm and the diameter is 0.15mm, while the dot 10 spacing on the opposing surface 1d is 0.35mm and the diameter is 0.25mm. The total area ratio of the dot 10 can jump from 1.18% to 4.91%, an increase of over 300%. This substantial increase in ratio can completely solve the problem of extremely weak light at the far end in large-size light guide plates 1 and large-pitch LED layouts, ensuring full-surface brightness without the need to increase the number of LEDs.

[0075] In this embodiment, the dual design of increasing the number and size of the dot matrix 10 maximizes the probability of light breaking total internal reflection. Under the same brightness requirements, LED power can be reduced, achieving energy efficiency. Simultaneously, the high luminous efficiency supports large LED spacing, thereby reducing the number of LEDs and lowering the cost of the light source. Furthermore, the high luminous efficiency design reduces the number of homogenizing film layers (from two layers to a single layer), further compressing material costs.

[0076] This design allows for parameter adjustments based on the structural shape of the light guide plate 1. For example, with an ultra-thin light guide plate 1, the light output can be increased without compromising structural strength by "slightly increasing the quantity and significantly enlarging the size." For irregularly shaped light guide plates 1 (such as curved or trapezoidal ones), the quantity and size ratio can be adjusted differently for different light propagation paths in different areas to achieve uniform light output from the irregularly shaped plate surface. This flexible design meets the current trend of thinner and more irregularly shaped products in the consumer electronics field.

[0077] Following on from the above, that is, in the first form where only the number of dots per unit area is increased (density increased, size unchanged), further, please refer to... Figure 3 and Figure 5 Along the second direction Y, the distance between two adjacent grid points 10 gradually decreases.

[0078] In the first form, the core is to "fix the size of a single dot 10 and increase the proportion of the total area of ​​dots 10 per unit area". The only way to achieve this goal is to reduce the spacing between dots 10 and increase the number of dots 10 per unit area. Under the premise that the size of dots 10 remains unchanged, the smaller the spacing, the more dots 10 can be accommodated per unit area, and the higher the proportion of the total area of ​​dots 10.

[0079] Considering the design requirements of the light guide plate 1 in the second direction Y (the light linearly attenuates along the incident surface 1c to the opposing surface 1d, requiring a gradual increase in the area of ​​the halftone dots 10 per unit area), the specific implementation method of the first form is to make the spacing between adjacent halftone dots 10 gradually decrease along the second direction Y in an arithmetic progression or linear gradient, that is, the maximum spacing h3 between two adjacent halftone dots 10 starts from 0.6mm (e.g., ...). Figure 3 The distance from 10 to the minimum spacing h4 between two adjacent dots is 0.35mm (e.g., Figure 5 That is, by gradually reducing the spacing, the number of dots 10 per unit area increases continuously from the incident surface 1c to the opposing surface 1d, thereby achieving a linear increase in the proportion of dots 10, which can well match the light attenuation law.

[0080] In this embodiment, by gradually reducing the spacing between adjacent dots 10 along the second direction Y, the scattering characteristics of a single dot 10 are not affected. Since all dots 10 are of uniform size and shape, the light-destruction efficiency and emission angle of each scattering point are highly consistent, making it difficult to encounter the problem of "excessive local scattering" caused by differences in dot 10 size. After being scattered by dense and uniform dots 10, the angular distribution of the emitted light is more consistent, resulting in softer light texture without glare or speckles, making it particularly suitable for scenarios with stringent visual comfort requirements, such as automotive backlighting and smart wearable displays.

[0081] It is understandable that after light enters the light guide plate 1 from the light incident surface 1c, it will undergo linear attenuation due to material absorption and interface scattering, and the light intensity will be weaker the closer it is to the opposing surface 1d. The design of gradually decreasing spacing between adjacent dots 10 is perfectly negatively correlated with this attenuation trend: in the light incident surface 1c region where the light intensity peaks, a large spacing design is adopted, with fewer dots 10 per unit area, reducing premature scattering of light and avoiding glaring bright spots at the near end; as it extends towards the opposing surface 1d, the spacing gradually decreases, and the number of dots 10 per unit area increases linearly, with the scattering points becoming denser, which can maximize the destruction of total internal reflection conditions, fully scattering the residual light energy transmitted to the far end, and accurately making up for the brightness gap in the weak light area at the far end. More importantly, the reduction in spacing is a smooth and gradual change (like an arithmetic progression gradient) rather than an abrupt change, allowing the light intensity to transition continuously from the near end to the far end. There will be no brightness steps caused by abrupt changes in the density of the dot 10. Combined with the dot 10 distribution design in the first direction X, the brightness and uniformity of the light guide plate 1 can be improved.

[0082] The design of gradually decreasing spacing between adjacent dots 10 is essentially to achieve precise distribution of light energy for near-end light guiding and far-end light emission. In the light-incident surface 1c region, the larger dot spacing 10 will not excessively intercept the propagating light, ensuring that most of the light energy is transmitted to the far end in a highly efficient form of total internal reflection, avoiding the waste of near-end light energy due to premature scattering. In the opposing surface 1d region, the smaller dot spacing 10 will fully convert the light energy transmitted here into emitted light, maximizing the light energy potential of the light guide plate 1. Compared with the traditional uniform spacing design, it can greatly improve the light energy utilization rate and output higher brightness with the same LED power; conversely, under the same brightness requirement, the LED power can be further reduced, thereby achieving the goal of reducing the number of LEDs and reducing the cost of the light source.

[0083] Furthermore, the uniform size of the dots 10 and the smooth, gradually changing spacing ensure a more even stress distribution on the light guide plate 1. On one hand, it prevents stress concentration caused by excessively large local dots 10, ensuring that the dots 10 will not detach or deform during environmental tests such as high and low temperature cycling and damp heat aging, thus guaranteeing long-term stable optical performance. On the other hand, the uniform distribution of dots 10 allows for more balanced heat conduction on the light guide plate 1, avoiding heat accumulation caused by excessively high local dot density, and slowing down the yellowing and aging rate of the light guide plate 1, making it particularly suitable for harsh operating conditions such as outdoor displays and automotive applications.

[0084] On the other hand, the gradually decreasing spacing design can be precisely quantified using mathematical models such as arithmetic sequences and linear interpolation. Designers only need to calculate the light attenuation coefficient based on parameters such as the length of the light guide plate 1, the material transmittance, and the LED power to derive the gradual gradient of the spacing (such as a tolerance value from 0.6mm to 0.35mm). This parametric design mode gives the solution extremely high flexibility: for small-sized light guide plates 1, the spacing adjustment range can be narrowed; for large-sized light guide plates 1, the spacing adjustment gradient can be expanded; for different LED spacing layouts, only fine-tuning of the spacing parameters is needed for quick adaptation, without the need to redesign the dot 10 shape, significantly shortening the new product development cycle.

[0085] It should be understood that the dots 10 in the embodiments of this application can be protruding dots 10, recessed dots 10, or coated dots 10.

[0086] When the raised dots 10 are used, they can be raised dots 10 on the backlight surface 1b or on the light-emitting surface 1a. The three-dimensional structure of the raised dots 10 makes the medium interface on the surface of the light guide plate 1 more irregular. When light comes into contact with the raised arc or conical surface, the total internal reflection angle will change drastically, which can more effectively disrupt the total internal reflection propagation path of light in the light guide plate 1, forcing the light to scatter in the direction of the light-emitting surface 1a. Especially for the light guide plate 1 with a large-pitch LED layout, it can effectively make up for the brightness of the weak light area at the far end, and ensure the uniform brightness of the light-emitting surface 1a without increasing the LED power.

[0087] By designing the shape of the raised dots 10, the emission angle of light can be precisely controlled: hemispherical raised dots 10 can achieve wide-angle diffusion, suitable for scenarios requiring large-area light emission such as indoor lighting and smart home panels; conical and pyramidal raised dots 10 can achieve narrow-angle focusing, adapting to the directional light emission needs of automotive head-up displays, smart wearable devices, etc. This "shape determines angle" characteristic allows the raised dots 10 to meet differentiated optical design requirements without relying on additional prism films, reducing the number of optical film layers used.

[0088] It is also important to understand that, since the backlight surface 1b of the light guide plate 1 is generally equipped with a reflector (white support 3), and when the backlight surface 1b is a raised dot 10, the contact between the raised dot 10 and the reflector is a "point contact," which can effectively reduce air bubble residue during bonding and avoid light reflection disorder caused by air bubbles. At the same time, the raised structure is not easy to accumulate dust and moisture, and the light output efficiency will not decrease due to contaminants covering the dots 10 after long-term use. The UV curing molding process of the raised dots 10 on the light-emitting surface 1a can also form a wear-resistant coating on the surface of the dots 10, improving scratch resistance and extending the product's service life.

[0089] When the halftone dots 10 are recessed, the halftone dots 10 refer to the halftone dots 10 being formed in a shape lower than the surface of the light guide plate 1. In this embodiment of the application, the halftone dots 10 are formed by the backlight surface 1b being recessed towards the light-emitting surface 1a, which is an example of the backlight surface 1b being recessed with blind hole halftone dots 10.

[0090] Specifically, the dots 10 are recessed from the backlight surface 1b toward the light-emitting surface 1a, but do not penetrate the thickness of the light guide plate 1, and the bottom retains the complete substrate, while the light-emitting surface 1a remains absolutely flat. The molding method is mainly injection molding, in which a raised core is engraved on the surface of the mold cavity. After the molten polymethyl methacrylate or polycarbonate material is injected into the mold, the area squeezed by the core cools to form the concave blind hole dots 10. For high-precision scenarios, laser engraving can be used to form the dots 10 with micron-level precision by burning pits on the backlight surface 1b with a laser.

[0091] By setting the dot 10 as a blind aperture dot 10, and the inner wall of the recessed blind aperture dot 10 having an arc-shaped sloping structure, light will undergo diffuse reflection when it comes into contact with the inner wall, rather than specular reflection. The angle distribution of the emitted light is wider and more uniform, making it difficult to have the localized highlight concentration problem that may occur with the raised dot 10. For scenarios with strict requirements for visual comfort, such as in-vehicle central control screens and mobile phone displays, the recessed dot 10 can effectively avoid glare, pitting, and other adverse phenomena, ensuring the brightness uniformity of the light guide plate 1, and the light texture is closer to natural light.

[0092] The backlight surface 1b with recessed dots 10 has a high overall flatness, and its bonding with the white reflector is a surface contact, which can minimize light leakage caused by bonding gaps. Light that is not scattered by dots 10 will be conducted to the backlight surface 1b, and then efficiently reflected back into the light guide plate 1 by the reflector, participating again in the scattering and emission process of dots 10, which can improve the secondary utilization rate of light energy and significantly reduce light energy loss.

[0093] The recessed dots 10 are located on the backlight surface 1b of the light guide plate 1, while the light-emitting surface 1a has no protrusions or depressions, preventing damage to the dots 10 due to external scratches or collisions. Simultaneously, the recessed structure prevents stress concentration on the surface of the light guide plate 1, avoiding the risk of warping or deformation of the ultra-thin light guide plate 1. Under harsh conditions such as high and low temperature cycling and humid heat aging, the inner wall of the recessed dots 10 is encased in the substrate, preventing deformation or detachment, reducing the optical performance degradation rate, and making it suitable for long-term use scenarios such as automotive and outdoor displays.

[0094] In some possible embodiments, when the coating dots 10 are non-physically formed dots 10, they are formed by coating a scattering coating on the surface of the light guide plate 1 to form "virtual dots 10". They have no obvious uneven structure and are a preferred solution for low-cost mass production of large-size light guide plates 1. They are generally coating dots 10 on the backlight surface 1b.

[0095] The scattering particles of the coating dots 10 are randomly and uniformly distributed within the coating. After the light is scattered by the particles, the emitted light is softer and will not have the "dot matrix light spot" problem that may occur with physical dots 10 (raised / depressed), thus ensuring the uniformity of the light beam's brightness. For large-size light guide plates 1, the coating dots 10 can effectively avoid the bright and dark stripes caused by uneven density of physical dots 10, resulting in a more delicate visual effect.

[0096] By adjusting the coating thickness and scattering particle concentration in different areas, the gradient change in scattering efficiency can be precisely controlled: in the middle superimposed area of ​​the dual-LED layout, the coating concentration and thickness are reduced to decrease the light output; in the single-lamp coverage areas on both sides, the coating concentration and thickness are increased to enhance scattering efficiency. This control method does not require adjusting the spacing and size of the dots 10, but can be achieved simply by changing the coating parameters, significantly shortening the design cycle, and is especially suitable for the personalized optical design of irregularly shaped light guide plates 1.

[0097] To further reduce light loss, the light guide plate 1 has a facing surface 1d opposite to the light incident surface 1c. The facing surface 1d has a plurality of arched portions 20 protruding from it, and the plurality of arched portions 20 are arranged at intervals along the extending direction of the facing surface 1d.

[0098] The arched portion 20 protrudes outward as a whole. The arched portion 20 can be a right-angled triangular arched portion 20, an isosceles triangular arched portion 20, or a trapezoidal transition arched portion 20.

[0099] In the right-angled triangular arch 20, one of the two inclined surfaces faces the light-incident surface 1c (light-facing surface), and the other inclined surface faces the outside of the light guide plate 1, with a cross-section of a right-angled triangle. The tilt angle of the light-facing surface is usually designed to be 30° to 45°, which can precisely change the reflection angle of the end light; the outer inclined surface is an auxiliary surface to reduce interference between the arch 20 and other components.

[0100] In the isosceles triangular arch 20, two inclined planes are symmetrically distributed. The inclined plane facing the light-incident surface 1c is responsible for light reflection, while the other inclined plane is used to disperse stress and prevent the arch 20 from breaking due to unilateral stress. This type of structure has stronger stability and is suitable for thinner light guide plates 1.

[0101] In the trapezoidal transition arch 20, the top of the triangle is designed as a small plane rather than a cusp, which is equivalent to a combination structure of "triangle + plane". The small plane can reduce the excessive concentration of light at the cusp, avoid local bright spots, and meet the light uniformity requirements at the end of the large-size light guide plate 1.

[0102] By arranging multiple arched portions 20 at intervals along the extension direction of the opposing surface 1d, the entire width of the opposing surface 1d can be covered. This arrangement can intercept light rays propagating from the incident light surface 1c to the end as much as possible, reducing the light leakage area, and is suitable for narrow-bezel light guide plates 1.

[0103] It is understandable that, for a flat opposing surface 1d, when light propagates to the end, a small portion of the light will escape directly from the opposing surface 1d into the air because the angle of incidence is less than the critical angle, thus becoming an ineffective loss.

[0104] The inclined structure of the triangular arch 20 can forcibly change the incident angle of the light at the end. When the light hits the inclined surface facing the light-incident surface 1c, the incident angle will be amplified, thereby satisfying the condition of total internal reflection. The light will not escape, but will be reflected back into the light guide plate 1 and propagate again towards the light-out surface 1a. Finally, it will be scattered and emitted through the dots 10 or microstructures of the light-out surface 1a.

[0105] Therefore, by setting the arched portion 20, the light escape loss of the opposing surface 1d can be effectively reduced, and the overall light energy utilization rate of the light guide plate 1 can be improved. Under the same LED power, the output brightness is significantly improved; conversely, under the same brightness requirement, the LED power can be reduced, achieving energy-saving design.

[0106] While reflecting light, the arched portion 20 can also evenly distribute light to various areas at the end through the directional reflection of the inclined surface. This allows for adjustment of the reflected light density based on differences in light intensity at different locations at the end, ensuring that areas with weak light intensity receive more reflected light. Combined with the gradient arithmetic design of the dot 10 on the backlight surface 1b, the uniformity of the light-emitting surface 1a can be improved.

[0107] Furthermore, the arched portion 20 on the opposing surface 1d acts as a reinforcing rib, enhancing the structural strength of the end of the light guide plate 1 and preventing warping and deformation of the light guide plate 1 during injection molding and cooling. This is particularly suitable for the mass production requirements of ultra-thin light guide plates 1. At the same time, the triangular structure of the arched portion 20 provides a more uniform stress distribution, preventing breakage and detachment during high and low temperature cycles, thus extending the product's service life.

[0108] Please see Figure 6 and return the combination Figure 1 The light-emitting module 100 in this embodiment of the application also includes a white support 3, a circuit board 4, a diffusion film 5 (light-diffusing film), a black light-shielding component 6, and an outer lens 7 (mask). The white support 3, circuit board 4, light guide plate 1, diffusion film 5, black light-shielding component 6, and outer lens 7 are distributed sequentially along the thickness direction of the light guide plate 1.

[0109] White support component 3 refers to a white, high-reflectivity structural support component, typically made of white flame-retardant composite material or white frosted board. Its core characteristics are high reflectivity, high strength, and resistance to yellowing. It is installed on the outer side of the backlight surface 1b of the light guide plate 1, closely attached to the backlight surface 1b of the light guide plate 1, and serves as the load-bearing base for the entire light guide system, connecting the outer shell or other structural components.

[0110] It provides a stable mounting reference for core optical components such as light guide plate 1, circuit board 4, and diffusion film 5. Each component is fixed by clips, positioning posts or adhesive backing to prevent displacement of components due to vibration, temperature and humidity changes, and ensure the stability of the system's optical performance. It is especially suitable for the thin and light structure of flat light guide plate 1 to avoid warping and deformation of light guide plate 1.

[0111] The white surface has a high diffuse reflectivity, which can reflect the light leaked from the backlight surface 1b of the light guide plate 1 (the total internal reflection light that is not intercepted by the dot 10) back into the light guide plate 1, and participate in the light output control of the dot 10 for a second time, thereby improving the light energy utilization rate of the light guide system; combined with the light intensity compensation requirements of the dual LED large-pitch layout, it further reduces the light intensity attenuation in the far-end area.

[0112] The diffusion film 5, also known as the light-diffusing film, is an optical thin film with a microlens array or frosted structure on its surface, and is attached to the light-emitting surface 1a of the light guide plate 1.

[0113] The light emitted from the light guide plate 1 is scattered to eliminate defects such as "pockmarks" and "spots" caused by the dot matrix 10. At the same time, it bridges the local light intensity differences under the large-pitch layout of dual LEDs and improves the uniformity of the light-emitting surface 1a. The single-layer diffusion film 5 can achieve basic homogenization, while the double-layer structure can further improve the softness of the light and avoid glare.

[0114] By designing a microlens array, the angle of the emitted light can be controlled within a specific range (such as wide-angle or narrow-angle) to adapt to the light emission requirements of different application scenarios (such as narrow-angle anti-glare for automotive backlighting and wide-angle light amplification for indoor lighting).

[0115] In addition, the diffusion film 5 can also isolate the light guide plate 1 from direct contact with the outer lens 7, prevent the light-emitting surface 1a of the light guide plate 1 from being scratched, and block dust and fingerprints from contaminating the surface of the light guide plate 1.

[0116] The black light-shielding component 6 refers to black light-shielding adhesive, black light-shielding sheet, or black frame structure. Its material is generally black light-shielding PET adhesive, black ABS (Acrylonitrile Butadiene Styrene) frame, or black foam. Its core characteristics are high light-shielding performance, anti-static properties, and easy adhesion. It is mainly installed on the light-incident edge of the light guide plate 1 and the edge of the non-light-emitting area of ​​the light guide system.

[0117] It blocks the light that directly leaks from the LED and the stray light from the edge of the light guide plate 1, preventing light from overflowing from the non-light-emitting area; the black surface can absorb stray reflected light, preventing stray light from reflecting back into the system and interfering with the uniformity of light output, while improving the contrast between the luminous pattern and the background (especially suitable for character and icon backlighting scenarios).

[0118] For the light-incident side of the dual-LED wide-pitch layout, the black light-shielding component 6 can prevent the side leakage light of a single LED from directly illuminating the side of the light guide plate 1, thus preventing the problem of local over-brightness at the light-incident end.

[0119] The outer lens 7 (mask) is the outer light-transmitting component of the light guide system. It is divided into a flat transparent mask and a lens mask with optical texture. The material is optical grade acrylic or tempered glass. The surface can be treated with frosting, anti-fingerprint, anti-UV and other treatments.

[0120] Assembly location: Installed on the outside of the diffusion film 5, it is the outermost component of the entire light guide system.

[0121] By designing the light-transmitting and non-light-transmitting areas on the surface, preset luminous patterns (such as characters, icons, and strip lights) can be achieved; lens covers with optical textures (such as convex lenses and Fresnel lenses) can further adjust the light-emitting angle to achieve focusing or expanding light effects, adapting to different application scenarios (such as the need for focusing light for vehicle dashboard backlights and the need for expanding light for indoor ambient lights).

[0122] In addition, the outer lens 7 serves as the outer barrier of the system, preventing external scratches and impacts from damaging the internal optical components, while also blocking the intrusion of dust, moisture, and oil. Surface treatments (such as frosted, high-gloss, and gradient colors) enhance the product's appearance and meet the aesthetic requirements of consumer products. The mask made of UV-resistant material can adapt to strong light environments such as outdoor or automotive settings, preventing yellowing and aging after long-term use. The tempered glass mask also has the advantages of being explosion-proof and scratch-resistant, making it suitable for high-end products.

[0123] In this embodiment, the outer lens 7 works in conjunction with the diffusion film 5 to convert uniform light into a light-emitting pattern of a specific shape. At the same time, the optical texture further optimizes the light output softness of the large-pitch LED light guide system, enhancing the user's visual experience.

[0124] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. A light guide plate, characterized in that, It includes a light-emitting surface, a backlight surface, and a light-incident surface. The light-emitting surface and the backlight surface are arranged opposite to each other along the thickness direction of the light guide plate. The light-incident surface connects the light-emitting surface and the backlight surface. The backlight surface has a dotted area with halftone dots. Along a first direction and from the middle of the halftone area to both sides, the proportion of halftone dot area per unit area gradually increases. Wherein, the first direction is the extension direction of the light-incident surface.

2. The light guide plate according to claim 1, characterized in that, Along the first direction and from the center to both sides of the dot area, the number of dots per unit area gradually increases.

3. The light guide plate according to claim 1, characterized in that, Along the first direction and from the middle to both sides of the dot area, the spacing between two adjacent dots gradually decreases.

4. The light guide plate according to claim 2 or 3, characterized in that, The radii of the dots are all equal.

5. The light guide plate according to claim 3, characterized in that, In the first direction, the minimum distance between two adjacent dots in the first direction is h1, where h1 satisfies: 0.3mm ≤ h1 ≤ 0.4mm; and / or, The maximum distance between two adjacent dots in the first direction is h2, and h2 satisfies: 0.9mm≤h2≤1.0mm.

6. The light guide plate according to claim 1, characterized in that, The light guide plate has a facing surface opposite to the light incident surface. Along the second direction, the proportion of the dot area per unit area gradually increases. The second direction is perpendicular to the first direction and points from the light incident surface to the facing surface.

7. The light guide plate according to claim 1, characterized in that, The light guide plate has a facing surface opposite to the light incident surface. Along the second direction, the spacing between two adjacent dots gradually decreases. The second direction is perpendicular to the first direction and points from the light incident surface to the facing surface.

8. The light guide plate according to claim 1, characterized in that, The light guide plate has a facing surface opposite to the light incident surface, and the facing surface is provided with a plurality of arched portions, which are arranged at intervals along the extending direction of the facing surface.

9. The light guide plate according to claim 1, characterized in that, The backlight surface is recessed into the light-emitting surface to form the dots.

10. A light-emitting module, characterized in that, include: The light guide plate according to any one of claims 1-9; as well as, Multiple light-emitting elements are disposed on the side of the light-incident surface away from the light guide plate and are spaced apart along the first direction.

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