Brightness enhancement film and backlight module

Abstract

The utility model relates to a brightness enhancement film which can improve the brightness, definition and optical performance of a liquid crystal display product, and efficient utilization and uniform distribution of light are achieved by introducing a non-uniformly distributed convex microstructure design into a back coating of the brightness enhancement film. The brightness enhancement film is composed of a prism layer, a base material layer and a back coating layer, the back coating layer is manufactured through a unique roller mold transfer printing technology, and convex microstructures of various shapes and sizes are formed. The light is effectively scattered and diffused, and the utilization rate of the light and the brightness of the screen are improved. A concave pattern structure is formed in a random impact force mode, so that a convex microstructure has random depth and shape, and the light scattering effect is further enhanced. The brightness enhancement film is low in cost, high in utilization rate and high in processing efficiency, has the capability of processing multiple structures at the same time, can be widely applied to the display field, and improves the overall performance of display products.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a brightness enhancement film and a backlight module. Background Art

[0002] The liquid crystal display (LCD) industry is deeply loved by consumers around the world for its continuous technological advancements and cost-effectiveness. As market demands for display quality continue to rise, particularly the pursuit of a more vivid and vibrant visual experience, the performance optimization of optical films, a core component of LCD products, has become a focus of industry attention.

[0003] Despite significant advancements in LCD technology in recent years, including significant improvements in color saturation, contrast, and response speed, improving screen brightness, a key metric, remains challenging. While traditional optical films meet basic optical requirements to a certain extent, their performance bottlenecks are becoming increasingly apparent in the face of growing demand for high brightness, wide viewing angles, and glare-free displays. In backlight modules, in particular, achieving improved light source efficiency while minimizing optical losses through innovative design presents a pressing technical challenge.

[0004] Against this backdrop, a technology is needed that overcomes the limitations of traditional brightness-enhancing films, improves product brightness, and effectively enhances the transmission and scattering efficiency of light between film layers, ensuring image clarity while achieving a dramatic increase in brightness. Furthermore, this technology optimizes the light diffusion angle for a more uniform distribution, further enhancing viewing comfort and visual experience. Beyond these challenges, practical solutions remain, such as how to further reduce production costs, improve production efficiency, and enhance product durability and environmental adaptability. Utility Model Content

[0005] The purpose of the present application is to provide a brightness enhancement film, which has better shielding and anti-interference performance, the highest overall optical benefit, low cost, high utilization rate, high processing efficiency, and can also process multiple structures simultaneously. The purpose of the present application is achieved through the following technical solutions. The brightness enhancement film of the present application includes a prism layer, a substrate layer and a back coating layer;

[0006] The prism layer is formed on the light-emitting surface of the substrate layer, and the back coating layer is formed on the other surface of the substrate layer opposite to the prism layer;

[0007] The back coating layer includes a convex microstructure, and the protruding direction of the convex microstructure forms an angle with the surface of the back coating layer;

[0008] The convex microstructures are in the shape of a circle, a triangle, a polygon or an ellipse, and have two or more sizes.

[0009] In one embodiment, the convex microstructure is obtained by transfer printing from a roller mold.

[0010] In one embodiment, a concave pattern structure corresponding to the convex microstructure is formed on the roller mold by a geometric pattern tool in a dot-impacting manner.

[0011] In one embodiment, the depth of the concave graphic structure is randomly varied by using random impact force.

[0012] In one embodiment, the difference in size of the convex microstructures is in the range of 0-80 μm, and the height difference between the largest convex microstructure and the smallest convex microstructure is in the range of 2-30 μm.

[0013] In one embodiment, the size of the convex microstructures is in the range of 10-90 μm.

[0014] In one embodiment, the convex microstructure is a pyramid structure, and the top angle of the structure is in the range of 50-120°.

[0015] In one embodiment, the back coating layer includes more than three regions, and adjacent regions have convex microstructures of different shapes and / or different sizes.

[0016] In one embodiment, the convex microstructures in the central region of the back coating layer have larger sizes than the convex microstructures in the edge region.

[0017] In addition, the present application also provides a backlight module, which uses the aforementioned brightness enhancement film.

[0018] Compared with the prior art, the present application has the following beneficial effects: The brightness-enhancing film of the present application not only improves the optical performance of liquid crystal display products, but also optimizes production efficiency and cost structure. The brightness-enhancing film adopts a back coating design, in which the convex microstructures are randomly distributed in various shapes (circular, triangular, polygonal, elliptical, etc.) and sizes. This non-uniform design effectively enhances the scattering and diffusion ability of light, making the transmission of light between the film layers more uniform, thereby significantly improving the overall optical efficiency. At the same time, by controlling the depth variation of the convex microstructures, the optical gain effect is further enhanced, making the brightness-enhancing film perform well in improving brightness. The convex microstructures in the back coating not only improve brightness, but also effectively reduce the occurrence of optical interference through their complex geometric form, making the picture clearer and free of stray light. In addition, this design also enhances the shielding properties of the brightness-enhancing film, which can effectively block unnecessary light interference and improve the viewing experience.

[0019] The brightness enhancement film of this application can be produced using roller mold transfer technology to produce a back coating, which offers significant advantages of low cost and high processing efficiency. Through the impact dotting method of geometric pattern cutting tools, the shape, size, and depth of the microstructure can be flexibly controlled, enabling large-scale, high-precision production. In summary, the brightness enhancement film of this application excels in improving optical benefits, reducing costs, increasing production efficiency, enhancing shielding and anti-interference properties, and improving durability and environmental adaptability, thereby enhancing the overall performance of liquid crystal display products. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of a brightness enhancement film in one embodiment of the present application;

[0021] Figure 2 It is a schematic structural diagram of the back coating layer in the brightness enhancement film in one embodiment of the present application.

[0022] Explanation of reference numerals: 100, prism layer; 200, substrate layer; 300, back coating layer; 310, convex microstructure. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some, rather than all, structures related to the present application are shown in the accompanying drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0024] As used herein, the terms "comprise," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0025] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] As a type of optical film, brightness enhancement film can significantly enhance light utilization and scattering effects through optical design, thereby effectively improving screen brightness and clarity. Although traditional brightness enhancement film has met market demand to a certain extent, its performance bottleneck has gradually emerged when facing the stringent requirements of high-end display products. This application proposes an innovative brightness enhancement film technology, which provides a new solution by introducing a unique back coating 300 manufacturing process and adopting a non-uniformly distributed convex microstructure 310 design. Figures 1 to 2 As shown, the brightness enhancement film in a preferred embodiment of the present application has better shielding and anti-interference performance, the highest overall optical benefit, low cost, high utilization rate, and high processing efficiency. The brightness enhancement film of the present application has better shielding and anti-interference performance, the highest overall optical benefit, low cost, high utilization rate, and high processing efficiency, and can also process multiple structures at the same time. The purpose of the present application is achieved through the following technical solutions. The brightness enhancement film specifically includes a prism layer 100, a substrate layer 200 and a back coating layer 300, the prism layer 100 is formed on the light-emitting surface of the substrate layer 200, the back coating layer 300 is formed on the other surface of the substrate layer 200 relative to the prism layer 100, the back coating layer 300 includes a convex microstructure 310, the protruding direction of the convex microstructure 310 has an angle with the surface of the back coating layer 300, wherein the shape of the convex microstructure 310 is circular, triangular, polygonal or elliptical, and the convex microstructure 310 has two or more sizes. The structure of the present application is not limited to the micro single prism sheet back coating 300, and can also be used as a composite film back coating 300.

[0027] The prism layer 100, substrate layer 200, and back coating layer 300 work together to maximize light utilization efficiency and display quality. The prism layer 100 is located on the light-emitting surface of the substrate layer 200. Its main function is to refract and converge light through a precise prism structure. The design of the prism layer 100 allows light emitted from the backlight module to be guided to the display area at a predetermined angle and direction, effectively reducing light scattering losses and thereby improving the front brightness of the screen. The substrate layer 200, as the supporting structure between the prism layer 100 and the back coating layer 300, has excellent optical transparency, ensuring that light is not significantly absorbed or scattered when passing through. The back coating 300 incorporates convex microstructures 310 of various shapes (circular, triangular, polygonal, elliptical, etc.) and sizes. These microstructures protrude from the surface of the back coating 300 at specific angles, forming an optical interface. The convex microstructures 310 of varying shapes and sizes effectively scatter and diffuse incident light, causing it to undergo multiple reflections and refractions within the back coating 300. This increases the light's transmission path and residence time between film layers. This process not only improves light utilization but also makes light distribution more uniform, effectively enhancing screen brightness and viewing angles. The uneven distribution and complex morphology of the convex microstructures 310 effectively reduce optical interference and stray light interference on the screen. Furthermore, the shielding effect of the microstructures can also partially block backlight leakage from the backlight module, further improving image contrast and clarity.

[0028] In some embodiments, the substrate layer 200 and the back coating layer 300 may be formed as a whole, without strictly distinguishing the specific structures.

[0029] Specifically, the convex microstructure 310 is obtained by transfer printing through a roller mold. The mold after processing is transferred to the desired back coating 300 by UV printing process. Figure 1 The protruding microstructures are circular, and all the protruding microstructures are uniform in shape, which can make the light entering from all directions more uniform, and has a certain effect on improving the brightness; on the other hand, the depth of the structure changes with the impact force, and the effect is also Figure 1 , can have a variable microstructure size, which has a certain effect on improving diffusion and shielding properties. By using innovative roller mold transfer technology to produce the back coating 300, this brightness enhancement film achieves large-scale, high-precision production. This process not only simplifies the production process but also reduces production costs, making it easier for brightness enhancement films to be widely used in the LCD industry.

[0030] Specifically, a concave graphic structure corresponding to the convex microstructure 310 is formed on the roller mold by a geometric tool in a dot-impacting manner. In the specific processing process, the processing is realized by selecting unconventional geometric tool such as circular, triangular, polygonal, and elliptical shapes. The geometric figure is impacted on the roller mold in a dot-impacting manner, and a corresponding graphic structure is left on the mold body; the finished product is a random-sized dot structure, which is different from the linear continuous cutting of the front case. The front case continuous cutting uses a fast tool servo tool. Due to the limitation of the vibration frequency, the cutting depth difference is limited, generally less than 2μm. Using the impact process proposed in this application, on the one hand, any graphic can be obtained according to the shape of the tool head, and on the other hand, a larger depth difference can be obtained. As the depth of the microstructure increases, its optical gain effect can be improved to improve the optical benefit of the overall brightening film. After the back coating 300 is completed, the front prism layer 100 is produced by a UV transfer process to complete the production of the complete brightening film. The final product is as follows. Figure 2 .

[0031] To further enhance its optical performance, a random impact force method is used to form the concave pattern. This random impact force method causes the depth and size of the concave pattern to vary randomly. The force of each impact on the roller mold varies randomly. This randomness is reflected not only in the magnitude of the impact force, but also in multiple dimensions such as the angle, speed, and duration of the impact. This ensures that the depth and size of the concave pattern are highly random and unpredictable. The back coating 300 microstructure is achieved by uneven impact using a geometric tool. After the concave pattern of random depth and shape is transferred from the back coating 300 to the convex microstructure 310, it can more effectively scatter and diffuse light. This non-uniform optical interface causes light to reflect and refract multiple times between the film layers, increasing the light transmission path and residence time within the film layers, significantly improving light utilization and screen brightness. This technology simplifies the mold processing and the back coating 300 production process. By reducing the reliance on continuous cutting processes and complex servo systems, this technology reduces production costs and improves production efficiency, making large-scale production of brightness-enhancing films possible.

[0032] Specifically, the size difference of the convex microstructure 310 is in the range of 0-80 μm, and the height difference between the largest convex microstructure 310 and the smallest convex microstructure 310 is in the range of 2-30 μm. By controlling the size and height difference of the convex microstructure 310, the scattering and diffusion of light can be more effectively controlled. The size difference between the microstructures causes the light to continuously change direction during the propagation process, thereby improving the utilization rate of light and the brightness of the screen. Providing the convex microstructure 310 within a reasonable size range can ensure that the light is evenly scattered and diffused in all directions, which not only reduces the brightness difference and color deviation on the screen, but also improves visual comfort, so that users can get a consistent and clear visual experience when viewing the screen at different angles.

[0033] Specifically, the size of the convex microstructures 310 is within the range of 10-90 μm. Setting the size of the convex microstructures 310 within this range ensures that they produce appropriate scattering and diffusion effects on light. Microstructures within this size range can effectively increase the light transmission path and residence time within the film layer, improving light utilization and screen brightness, while also avoiding the problem of excessive or insufficient light scattering caused by oversized or undersized microstructures.

[0034] Specifically, the convex microstructures 310 are pyramidal structures with a vertices angle within the range of 50-120 degrees. The microstructures are finely processed pyramidal shapes, each with a defined vertices angle precisely controlled within the range of 50-120 degrees. This design ensures that the pyramidal structures not only provide effective light scattering and diffusion, but also further optimize the light transmission path through their unique geometry, thereby improving the overall performance of the brightness enhancement film. The 50-120 degree vertices ensure that the pyramidal structures effectively prevent excessive light concentration while ensuring sufficient light transmission and scattering within the film layer, thereby improving the overall brightness and uniformity of the screen.

[0035] Specifically, the back coating 300 includes three or more regions, with adjacent regions having convex microstructures 310 of different shapes and / or sizes. Dividing the back coating 300 into multiple regions and deploying convex microstructures 310 of different shapes and / or sizes in each region can enhance the brightness enhancement film's ability to control light in different regions, thereby improving overall light uniformity.

[0036] Specifically, the convex microstructures 310 in the central region of the back coating 300 are larger than the convex microstructures 310 in the edge regions. The larger convex microstructures 310 more effectively scatter and diffuse light, allowing it to be more fully utilized in the central region, thereby improving screen brightness and providing a brighter, clearer image. The smaller convex microstructures 310 in the edge regions help reduce excessive scattering and reflection of light at the edges, thus avoiding bright spots or halos.

[0037] Specifically, in areas with larger convex microstructures 310, the prismatic structures on the light-emitting surface of the substrate layer 200 are also larger. This coordinated design in size aims to optimize the light transmission path and refraction angle within the brightness enhancement film. The combination of the large convex microstructures 310 and the large prismatic structures creates a smoother light transmission path, helping to reduce the number of light reflections and scattering within the brightness enhancement film, thereby reducing light loss and improving light transmission efficiency.

[0038] Specifically, the back surface of the back coating 300 and the surface of the convex microstructures 310 are further sandblasted. This sandblasting treatment results in a smoother and more delicate surface, reducing light scattering and reflection losses on the surface, thereby improving light transmittance and utilization. Furthermore, due to the altered surface microstructure, light is scattered and diffused more evenly during transmission. Sandblasting removes minor surface defects and stress concentration points, reducing cracks and breakage caused by stress concentration during use.

[0039] In addition, the present application also provides a backlight module that utilizes the aforementioned brightness enhancement film. Because the brightness enhancement film has excellent light scattering and diffusion capabilities, the light output by the backlight module is more concentrated and brighter. Because the brightness enhancement film can improve light utilization and transmission efficiency, the backlight module consumes less energy when outputting light of the same brightness, helping to reduce the operating costs of the device.

[0040] The technical solution of the present application is further described below with specific implementation methods, and the existing technology is used for comparison.

[0041] Example 1

[0042] The new back coating mentioned in this application was used in combination with a 24P prism, and the results showed that the overall effect was the best, with brightness 6% higher than that of contrast 1, and both shielding and anti-interference properties were improved.

[0043] Comparative Example 1

[0044] It uses the particle back-coating structure that is more common in the market and is combined with a 24P prism.

[0045] Comparative Example 2

[0046] It uses the sandblasting back coating structure which is more common in the market and is equipped with 24P prism.

[0047] Comparative Example 3

[0048] It uses the FTS back-coated structure which is less common in the market and is equipped with a 24P prism.

[0049] Table 1 Performance test results of specific implementation methods

[0050]

[0051] The comparison results of the above embodiments show that it has the best comprehensive display effect, with brightness 6% higher than that of comparative example 1, and both shielding and anti-interference properties are improved. In the technical solution of comparative example 1, its comprehensive effect is the worst. In the technical solution of comparative example 2, the anti-interference effect is improved, and the brightness is 2% higher than that of comparative example 1. In the technical solution of comparative example 3, the brightness is improved but the anti-interference effect is poor. By comparing with different back coating structures currently available on the market, the new back coating structure proposed in this application has better shielding and anti-interference performance, and the overall optical benefit is also the highest.

[0052] As can be seen from the above, the present application proposes a new brightness enhancement film. This technology adopts a non-uniformly distributed convex microstructure design to achieve efficient utilization and uniform distribution of light. The brightness enhancement film is composed of a prism layer, a substrate layer and a back coating layer. The back coating layer integrates convex microstructures of various shapes and sizes. The non-uniform concave graphic structure formed by random impact force forms an efficient convex microstructure after transfer. These microstructures protrude from the back coating surface at a specific angle, effectively scattering and diffusing light, improving light utilization and screen brightness. Through the design of non-uniformly distributed convex microstructures, multiple reflections and refractions of light between film layers are achieved, increasing the light transmission path and residence time, thereby improving light utilization and screen brightness; secondly, the shielding effect of the convex microstructure effectively blocks backlight leakage, improving the contrast and clarity of the picture; the concave graphic structure formed by random impact force makes the convex microstructure have random depth and shape, enhancing the scattering and diffusion effect of light.

[0053] The brightness enhancement film of this application is not only low-cost, highly efficient, and has high processing efficiency, but also capable of simultaneously processing multiple structures, making it widely applicable to various liquid crystal display products. Furthermore, this application also provides a backlight module using the aforementioned brightness enhancement film. Through the synergistic effect of the brightness enhancement film and other components of the backlight module, an efficient and stable backlight system is constructed, improving the overall performance of the display product.

[0054] The above is only a specific implementation of the present application. Any other improvements made based on the concept of the present application are considered to be within the scope of protection of the present application.

Claims

1. A brightness enhancement film, characterized in that: It includes a prism layer (100), a substrate layer (200) and a back coating layer (300); The prism layer (100) is formed on the light-emitting surface of the substrate layer (200), and the back coating layer (300) is formed on the other surface of the substrate layer (200) opposite to the prism layer (100); The back coating layer (300) includes a convex microstructure (310), and a protruding direction of the convex microstructure (310) forms an angle with the surface of the back coating layer (300); The convex microstructure (310) is in the shape of a circle, a triangle, a polygon or an ellipse, and has two or more sizes.

2. The brightness enhancement film according to claim 1, characterized in that The convex microstructure (310) is obtained by transfer printing through a roller mold.

3. The brightness enhancement film according to claim 2, characterized in that: A concave graphic structure corresponding to the convex microstructure (310) is formed on the roller mold by a geometric graphic tool in a manner of impact dotting.

4. The brightness enhancement film according to claim 3, characterized in that: By using random impact force, the depth and size of the concave graphic structure are randomly changed.

5. The brightness enhancement film according to claim 1, characterized in that: The difference in size of the convex microstructures (310) is within the range of 0-80 μm, and the height difference between the largest convex microstructure (310) and the smallest convex microstructure (310) is within the range of 2-30 μm.

6. The brightness enhancement film according to claim 5, characterized in that: The size of the convex microstructure (310) is in the range of 10-90 μm.

7. The brightness enhancement film according to claim 5, characterized in that: The convex microstructure (310) is a pyramid structure, and the top angle of the structure is in the range of 50-120 degrees.

8. The brightness enhancement film according to claim 1, characterized in that: The back coating layer (300) includes more than three regions, and adjacent regions have the convex microstructures (310) of different shapes and / or different sizes.

9. The brightness enhancement film according to claim 8, characterized in that: The convex microstructures (310) in the central region of the back coating (300) have a larger size than the convex microstructures (310) in the edge region.

10. A backlight module, characterized in that: The method uses the brightness enhancement film according to any one of claims 1 to 9.

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