Integrated multifunctional brightening film and its preparation method

Abstract

This invention discloses an integrated multifunctional brightness enhancement film and its preparation method, relating to the field of optical film technology. The brightness enhancement film structure includes: a substrate layer having opposing first and second surfaces; a light-uniforming functional layer disposed on the first surface of the substrate layer, the light-uniforming functional layer having a patterned structure to form at least one light-transmitting region allowing complete light penetration and a light-reflecting shielding region; a diffusion functional layer disposed on the second surface of the substrate layer; and a prism layer disposed on the surface of the diffusion functional layer away from the substrate layer; wherein the surface of the prism layer has a height difference morphology corresponding to the patterned structure of the light-uniforming functional layer. This invention addresses the problem that existing technologies lack a multilayer integrated brightness enhancement film capable of simultaneously achieving efficient light uniformity, diffusion-enhanced brightness, and shielding functions with a single film structure, making it difficult to maintain high brightness output while simultaneously meeting performance requirements such as anti-interference, anti-adsorption, and display uniformity.

Description

Technical Field

[0001] This invention relates to the field of optical film technology, and in particular to an integrated multifunctional brightness enhancement film and its preparation method. Background Technology

[0002] Backlight modules are widely used in LCD displays, Mini-LED displays, and various display terminals. Their main function is to diffuse, homogenize, and brighten the light source to improve the brightness and uniformity of the displayed image. Existing backlight modules typically consist of multiple layers of optical substrates and films stacked together. From bottom to top, they generally include a reflective sheet, a diffuser plate, a diffuser film, a brightness enhancement film, and a reflective polarizing plate. Through the cooperation of multiple layers of optical components, they achieve the diffusion, mixing, and brightness enhancement of a point light source.

[0003] Currently, to reduce the number of optical film layers and simplify the assembly process, some technologies have adopted a bonding method to form a multi-functional film combining diffusion film and brightness enhancement film, thereby reducing the number of assembly layers and assembly complexity. However, most existing bonded optical films can only achieve functional integration between diffusion film and brightness enhancement film. For diffusion plates, which are plate components with both high diffusion performance and structural support performance, it is still difficult to effectively integrate them with other optical film layers. Therefore, a truly all-in-one integrated optical film structure cannot yet be formed.

[0004] Furthermore, with the development of Mini-LED backlight technology, the high light-emitting point density and strong local brightness of Mini-LED light sources place higher demands on the light uniformity and shielding performance of backlight modules. In existing technologies, to eliminate LED light spots and improve image uniformity, multiple diffusion films, light-diffusing films, or diffusion plates are typically stacked, which not only increases the overall structural thickness and material costs but also leads to increased light energy loss and more complex assembly processes.

[0005] In particular, current technology lacks a multi-layer integrated brightness enhancement film that can simultaneously achieve efficient light homogenization, diffusion enhancement, and shielding functions with a single film structure. This makes it difficult to maintain high brightness output while also meeting performance requirements such as anti-interference, anti-adhesion, and display uniformity. No effective solution has yet been proposed to address these issues. Summary of the Invention

[0006] Objective of the invention: To provide an integrated multifunctional brightening film and its preparation method, so as to at least solve one of the problems existing in the prior art.

[0007] Technical solution: An integrated multifunctional brightness enhancement film, comprising: A substrate layer having opposing first and second surfaces; A light-uniforming functional layer is disposed on the first surface of the substrate layer. The light-uniforming functional layer has a patterned structure to form at least one light-transmitting area that allows light to pass through completely and a light-shielding area that reflects light. A diffusion functional layer is disposed on the second surface of the substrate layer; and A prism layer is disposed on the surface of the diffusion functional layer away from the substrate layer; The surface of the prism layer has a height difference morphology corresponding to the patterned structure of the light-uniforming functional layer, so as to have anti-interference and anti-adsorption functions.

[0008] Preferably, the light-uniforming functional layer is a white coating or white film with pores; Wherein, when the coating is white, the light-transmitting area is a hole formed by patterned coating without any coating material covering it; When the film is white, the light-transmitting area is a hole formed by stamping, and the body of the white film constitutes the shielding area.

[0009] Preferably, the light-transmitting area comprises multiple holes, and the arrangement of the multiple holes is AM mode, FM mode, or AM / FM mixed mode; In the AM mode, the positions of the multiple holes are fixed, and the size of at least some of the holes exhibits a regular variation. The FM mode is characterized by a fixed size of multiple holes, and a regular variation in their distribution density on the light-uniforming functional layer.

[0010] Preferably, the diffusion functional layer is formed by curing a resin coating containing diffusion particles, and the haze of the diffusion functional layer is 30% to 80%.

[0011] Preferably, the light-diffusing particles of the diffusion functional layer are at least one of PMMA polymer and inorganic silicon dioxide, and their particle size is 1μm~10μm.

[0012] Preferably, the prism structure of the prism layer is a linear prism structure, selected from any one of equal-height prisms, unequal-height prisms, dithering prisms, or non-dithering prisms.

[0013] Preferably, the substrate layer is one of PET film, PC film, PMMA film or transparent plastic film, and its thickness is 50μm to 300μm.

[0014] To achieve the above objectives, according to another aspect of this application, a method for preparing an integrated multifunctional brightening film is also provided.

[0015] A method for preparing an integrated multifunctional brightening film according to this application includes the following steps; A substrate layer is provided having opposing first and second surfaces; A light-uniforming functional layer is formed on the first surface of the substrate layer, and the light-uniforming functional layer has a patterned structure to define at least one light-transmitting area and one shading area. A diffusion functional layer is formed on the second surface of the substrate layer; A UV-curable adhesive is applied to the surface of the diffusion functional layer on the side away from the substrate layer; The light-curing adhesive is pressed using a mold with a prism-shaped pattern; UV light is applied from one side of the uniform light functional layer, and the UV light passes through the patterned structure and irradiates the UV-curable adhesive, causing the UV-curable adhesive to produce non-uniform curing shrinkage in different areas. Demolding forms a prism layer with a height difference morphology on its surface corresponding to the patterned structure of the light-uniforming functional layer.

[0016] Preferably, the step of forming the light-uniforming functional layer includes: Apply white paint and print graphic designs, leaving some areas unpainted to create holes that allow light to pass through; or, A white film is provided, and holes forming light-transmitting areas are pre-punched on the white film. The white film with holes is then attached to the first surface of the substrate layer.

[0017] Preferably, the step of forming the diffusion functional layer includes: A resin coating containing diffusing particles is applied and cured, wherein the diffusing particles are polymethyl methacrylate particles or other organic or inorganic particles, so that the haze of the diffusing functional layer reaches 30% to 80%.

[0018] Beneficial effects: In this embodiment, an optimized bonding-type brightness enhancement film architecture is adopted. By using a single substrate layer and setting three functional layers on the substrate layer, and making the surface of the prism layer have a height difference morphology corresponding to the patterned structure of the light-uniformation functional layer, the purpose of providing high haze uniform light effect while also having anti-interference and anti-adsorption functions is achieved. This achieves the technical effect of all-in-1 optical effect, and solves the technical problem that the existing technology lacks a multi-layer integrated brightness enhancement film that can simultaneously achieve efficient light uniformity, diffusion brightness enhancement and shielding functions with a single film structure, and it is difficult to maintain high brightness output while taking into account the performance requirements of anti-interference, anti-adsorption and display uniformity. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the brightening film of the present invention; and Figure 2 This is a schematic diagram of the uniform light functional layer structure of the brightness enhancement film of the present invention.

[0020] The attached figures are labeled as follows: 10. Substrate layer; 20. Light-diffusing functional layer; 201. Light-transmitting area; 202. Shading area; 30. Diffusion functional layer; 40. Prism layer. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] like Figure 1-2 As shown, this application relates to an integrated multifunctional brightness enhancement film and its preparation method. Figure 1As shown, the integrated multifunctional brightening film includes: a substrate layer 10 having opposing first and second surfaces; a light-uniforming functional layer 20 disposed on the first surface of the substrate layer 10, the light-uniforming functional layer 20 having a patterned structure to form at least one light-transmitting region 201 for complete light penetration and a light-reflecting shielding region 202; a diffusion functional layer 30 disposed on the second surface of the substrate layer 10; and a prism layer 40 disposed on the side surface of the diffusion functional layer 30 away from the substrate layer 10; wherein the surface of the prism layer 40 has a height difference morphology corresponding to the patterned structure of the light-uniforming functional layer 20 to provide anti-interference and anti-adsorption functions.

[0026] Specifically, the substrate layer 10 serves as the main supporting structure of the entire integrated multifunctional brightness enhancement film, supporting the light uniform layer 20, the diffusion layer 30, and the prism layer 40, and providing a stable adhesion interface for each functional layer. Meanwhile, the first surface and the second surface are used to form different functional layers, so that multiple optical functions can be integrated on the same substrate, thereby reducing the stacked structure of multilayer films and plates in traditional backlight modules.

[0027] Its beneficial effects are as follows: by using a single substrate as the overall functional integration carrier, the bonding process between traditional multi-layer structures such as diffuser plates, diffuser films, and brightness enhancement films can be effectively reduced, thereby reducing assembly complexity and material quantity. At the same time, it is conducive to reducing the thickness of the backlight module and improving the product's thinness. In addition, the single substrate structure can also reduce the risk of interlayer misalignment and improve overall optical consistency and structural stability.

[0028] The light-uniforming functional layer 20 is formed on the first surface of the substrate layer 10, and its main function is to uniformly process the backlight and control the light shielding. The light-uniforming functional layer 20 can be formed by printing a white high-reflectivity coating, which may contain TiO2 particles, white resin material or other optical materials with high reflectivity; or, the light-uniforming functional layer 20 can also be achieved by laminating a pre-made white film, on which multiple light-transmitting holes are pre-formed.

[0029] The patterned structure includes a light-transmitting area 201 and a shielding area 202. The light-transmitting area 201 can be a circular hole, an elliptical hole, a polygonal hole, or an irregular hole structure, used to allow some light to pass through directly; preferably, it is a circular hole. The shielding area 202 is composed of a white reflective layer, used to reflect and recover the light that does not pass through, thereby improving the overall light utilization efficiency. The aperture size, spacing, and distribution of the light-transmitting area 201 can be optimized according to the LED light source arrangement, for example, using AM mode, FM mode, or AM / FM hybrid mode, to improve the uniformity of the conversion from point light source to surface light source.

[0030] The uniform light functional layer 20 is patterned, that is, it has a fully transparent perforated area and a partially transparent white paint area, which can induce a non-uniform reaction efficiency of the light-curing adhesive layer.

[0031] Its beneficial effects are as follows: By setting a uniform light layer 20 with a patterned structure, regional light control can be performed on the LED point light source, allowing light to enter the subsequent optical layer only through specific light-transmitting areas 201, thereby effectively reducing LED bright spots and improving the uniformity of the displayed image. Simultaneously, since the shielding area 202 can reflect and recover light that does not pass through the holes, compared to the traditional high-haze diffuser plate's direct absorption or scattering of light energy, light loss can be significantly reduced, improving overall brightness output efficiency. Furthermore, the patterned structure can be specifically optimized according to different Mini-LED light source spacings, offering high adaptability and design freedom.

[0032] A diffusion layer 30 is disposed on the second surface of the substrate layer 10. Its main function is to perform secondary diffusion of light after it has passed through the uniform light layer 20, so as to further improve the uniformity of light output and reduce local spot phenomenon. The diffusion layer 30 may be formed by an optical resin coating containing diffusion particles, which may be PMMA particles, silicone particles, polystyrene particles or other organic or inorganic particles with light scattering properties.

[0033] The diffusion layer 30 can be set with different haze ranges according to actual application needs, such as 30% to 80%, to achieve a balance between brightness and uniformity. Lower haze is beneficial to improve brightness output, while higher haze is beneficial to improve light source shielding ability and image uniformity.

[0034] Its beneficial effects are as follows: by further scattering and diffusing light through the diffusion layer 30, local high-brightness areas generated by the LED light source can be eliminated, making the light distribution more uniform and improving the display quality. At the same time, the diffusion layer 30 can work synergistically with the aforementioned light-uniformation layer 20 to achieve excellent light uniformity while maintaining high brightness output, thereby reducing the need for multiple diffusion film layers in traditional backlight modules, which helps to reduce the overall structural thickness and material costs.

[0035] The prism layer 40 is disposed on the side of the diffusion functional layer 30 away from the substrate layer 10, and is used to directionally converge and brighten the diffused light to improve the brightness output of the display panel in the front viewing direction. The prism layer 40 can be formed by UV curing transfer printing process, and its surface has a continuously arranged prism structure, which can be equal-height prisms, unequal-height prisms, regular prisms, or irregular prism structures.

[0036] During the manufacturing process, UV-curable adhesive can be coated on the surface of the diffusion functional layer 30, and then imprinted using a prism mold. At the same time, UV light is irradiated from one side of the light-uniforming functional layer 20 to cure the adhesive and form a prism structure.

[0037] Its beneficial effects are as follows: by setting the prism layer 40, the originally diverged light can be refocused onto the front of the display panel, thereby improving the brightness and light energy utilization of the front. At the same time, the combination of the prism layer 40 and the diffusion layer 30 can achieve both brightness enhancement and uniform diffusion effect, realizing high brightness and high uniformity optical output. In addition, forming the prism layer 40 through UV transfer printing also has the advantages of high processing efficiency, high structural precision, and suitability for continuous roll-to-roll production.

[0038] As ultraviolet light passes through the uniform light functional layer 20, it is affected by the patterned distribution of the light-transmitting area 201 and the shielding area 202, resulting in differences in ultraviolet light intensity in different areas. Therefore, during the photocuring process, the UV-curable adhesive in the prism layer 40 will produce different curing reaction rates and shrinkage rates, thereby forming a height difference morphology corresponding to the patterned structure of the uniform light functional layer 20.

[0039] In other words, the surface of the prism layer 40 is not a completely regular uniform height structure, but forms an irregular surface morphology with microscopic height variations. This height difference can vary with the arrangement of holes in the light-uniforming functional layer 20.

[0040] To better understand the role of the prism layer 40 in this application, the following explanation is provided: The prism layer 40 is the last fabrication step. It is fabricated after the light-diffusing functional layer 20 and the light-diffusing functional layer 30 have been fabricated on both sides of the PET. Generally, the prism layer 40 is fabricated by applying a UV-curable adhesive to one side of the substrate layer 10 (which is the surface of the light-diffusing functional layer 30 in this application). While the front side of the adhesive is rolled with a prism structure mold, ultraviolet light is applied to the back side (which is the side of the light-diffusing functional layer 20 in this application) to perform UV transfer on the UV-curable adhesive. Then, the mold is removed to obtain the prism shape.

[0041] However, since UV light needs to pass through the uniform light functional layer 20 first, and this functional layer is patterned, meaning it has fully transparent perforated areas and partially transparent white paint areas, the UV light will exhibit a patterned light intensity distribution when it passes through. Because of the patterned light intensity distribution throughout the irradiated area during UV irradiation, non-uniform reaction efficiency of the UV-curable adhesive layer can be induced. This directly leads to different shrinkage rates in different areas of the UV-curable adhesive layer during the curing reaction, meaning that the coating thickness will have an uneven distribution. This thickness variation is directly related to the perforation pattern design of the uniform light functional layer 20.

[0042] Finally, the surface of the prism layer 40 after curing and demolding will have a patterned height difference. This height difference can have anti-adsorption (making the prisms uneven in height) and anti-interference functions (the prism morphology varies patternedly with the holes in the uniform light layer, which can avoid visual interference between the linear prism and the glass panel under the regular state).

[0043] As can be seen from the above description, this application achieves the following technical effects: In this embodiment, an optimized bonding-type brightness enhancement film architecture is adopted. By using a single substrate layer 10 and setting three functional layers on the substrate layer 10, and making the surface of the prism layer 40 have a height difference morphology corresponding to the patterned structure of the light-uniformation functional layer 20, the purpose of providing high haze uniform light effect while also having anti-interference and anti-adsorption functions is achieved. This achieves the technical effect of all-in-1 optical effect, and solves the technical problem that the existing technology lacks a multi-layer integrated brightness enhancement film that can simultaneously achieve efficient light uniformity, diffusion brightness enhancement and shielding functions with a single film structure, and it is difficult to maintain high brightness output while taking into account the performance requirements of anti-interference, anti-adsorption and display uniformity.

[0044] Furthermore, the light-uniforming functional layer 20 is a white coating or white film with pores; Wherein, when the coating is white, the light-transmitting area 201 is a hole in the uncoated paint formed by patterned coating; When the film is white, the light-transmitting area 201 is a hole formed by stamping, and the body of the white film constitutes the shielding area 202.

[0045] Specifically, the light-uniforming functional layer 20 can be constructed in two different forms: one is a white coating structure directly formed on the surface of the substrate layer 10, and the other is a white thin film structure adhered to the surface of the substrate layer 10. Both structures achieve selective light transmission and reflection / recycling by forming multiple light-transmitting holes.

[0046] When the light-diffusing functional layer 20 is a white coating, screen printing, gravure printing, inkjet printing, or other patterned coating processes can be used to form a white reflective layer with a specific pattern on the surface of the substrate layer 10, while the area not covered by the white coating forms a light-transmitting area 201. Since this light-transmitting area 201 is a directly retained transparent area, light can pass through completely.

[0047] When the light-uniforming functional layer 20 is a white film, multiple holes can be formed in advance on a white PET film, white PC film or other white optical film by mechanical stamping, laser drilling or etching. Then, the white film with holes is attached to the surface of the substrate layer 10, wherein the white film body constitutes the shielding area 202.

[0048] Its advantages lie in the fact that by providing two implementation methods—white coating and white film—the manufacturing process can be flexibly selected according to different production conditions and product requirements. The white coating solution is suitable for roll-to-roll continuous printing production, offering advantages such as high processing efficiency, low cost, and high pattern freedom; while the white film solution boasts advantages such as stable aperture size, high structural precision, and good durability. Furthermore, regardless of the structure used, the white areas can reflect and recover impermeable light, thereby effectively improving the overall brightness utilization rate.

[0049] like Figure 2 As shown, the light-transmitting area 201 consists of multiple holes, and the arrangement of the multiple holes is AM mode, FM mode, or AM / FM mixed mode; In the AM mode, the positions of the multiple holes are fixed, and the size of at least some of the holes exhibits a regular variation. The FM mode is characterized by a fixed size of multiple holes, and their distribution density on the light-uniforming functional layer 20 exhibits a regular variation.

[0050] Specifically, the light-transmitting area 201 is preferably composed of multiple holes, and each hole can be designed in a regular manner according to the arrangement of the LED light source and the requirements of the light field distribution. The holes can be arranged in a matrix, honeycomb, gradient or random mimicry pattern, and the layout can be optimized through AM mode, FM mode or AM / FM hybrid mode.

[0051] In the AM (Amplitude Modulation) mode, the positions of multiple holes remain fixed, but the aperture size varies regularly in different areas. For example, smaller apertures are set near the LED light source, and larger apertures are set far away from the LED light source to achieve a more even distribution of light.

[0052] The FM (Frequency Modulation) mode maintains a relatively consistent aperture size, but the aperture density or spacing varies regularly in different regions. For example, the aperture density is reduced in bright areas and increased in low-brightness areas to improve the overall uniformity of the light field.

[0053] The AM / FM hybrid mode combines changes in aperture size and aperture density to achieve a more refined uniform light control effect.

[0054] Its beneficial effects are as follows: By graphically optimizing the size, position, and density of the holes, the problem of localized bright spots caused by Mini-LED point light sources can be effectively improved, allowing the point light source to be more uniformly transformed into a surface light source. Compared with traditional uniform diffusion methods, this solution can achieve superior masking effect and image uniformity while reducing diffusion loss. In addition, the AM / FM hybrid mode can also be customized for different backlight module sizes and LED arrangements, expanding the product's applicability.

[0055] Furthermore, the diffusion functional layer 30 is formed by curing a resin coating containing diffusion particles, and the haze of the diffusion functional layer 30 is 30% to 80%.

[0056] Specifically, the diffusion functional layer 30 can be formed by coating and curing a transparent resin after mixing diffusion particles into it. The resin material can be a UV-curable resin, a thermosetting resin, an acrylic resin, or other transparent optical resin materials.

[0057] The haze of the diffusion layer 30 is preferably controlled within the range of 30% to 80%, where lower haze results in higher brightness output, while higher haze provides better diffusion uniformity. In practical applications, the haze can be adjusted according to the brightness and uniformity requirements of different display products.

[0058] Its beneficial effect is that by setting a diffusion functional layer 30 with a specific haze range, a good balance can be achieved between brightness and light uniformity. Compared with traditional high haze diffusion plates, this solution can utilize the reflection and recovery effect of the aforementioned light uniformity functional layer 20 to reduce light loss caused by high diffusion, thereby improving the overall light efficiency while maintaining high uniformity.

[0059] Furthermore, the light-diffusing particles of the diffusion functional layer 30 are at least one of PMMA polymer and inorganic silicon dioxide, and their particle size is 1μm~10μm.

[0060] When the particle size is small, a finer and more uniform scattering effect can be formed; when the particle size is large, the scattering angle and shielding ability can be improved. By adjusting the particle size and the addition ratio, the optical performance of the diffusion functional layer 30 can be further optimized.

[0061] Its beneficial effects are as follows: by using diffusion particles within a specific particle size range, light scattering uniformity can be effectively improved, and local bright spots and moiré patterns can be reduced. Meanwhile, PMMA microspheres have the advantages of high transparency and good processing stability, while silica microspheres have excellent heat resistance and weather resistance; both are beneficial to improving the long-term stability of the integrated brightness enhancement film.

[0062] Furthermore, the prism structure of the prism layer 40 is a linear prism structure, selected from any one of equal-height prisms, unequal-height prisms, dithering prisms, or non-dithering prisms.

[0063] Specifically, the prism layer 40 preferably adopts a continuously arranged linear prism structure to direct and converge light. The equal-height prism is a regular structure in which all prism units have the same height; the unequal-height prism is in which different prism units have different heights; the dithering prism is a structure in which the height or position of the prisms has slight shifts; and the non-dithering prism is a regular, continuously arranged structure.

[0064] Among them, unequal height prisms and dithering prisms can further reduce the optical interference caused by regular periodic structures.

[0065] Its beneficial effects are as follows: by setting different types of prism structures, brightness enhancement, viewing angle control, and anti-interference functions can be achieved simultaneously. In particular, unequal height or dithered prism structures can effectively reduce visual defects such as Newton's rings, rainbow patterns, and moiré patterns, thereby improving display quality. At the same time, linear prism structures can also improve the brightness utilization rate in the direct viewing direction and reduce light energy waste.

[0066] Furthermore, the substrate layer 10 is one of PET film, PC film, PMMA film or transparent plastic film, and its thickness is 50μm to 300μm.

[0067] Specifically, the substrate layer 10 is preferably made of an optical plastic material with high transparency, good dimensional stability, and good heat resistance. Different materials can be selected according to the product's flexibility requirements, thermal stability requirements, and processing methods.

[0068] Among them, PET film has the advantages of low cost and good processability; PC film has high impact resistance; and PMMA film has excellent light transmittance and optical properties.

[0069] Its advantages are: by controlling the thickness range of the substrate layer 10, both the flexibility of the roll material processing capability and the overall structural support strength can be considered. Compared with the traditional diffuser plate structure, this solution can significantly reduce the overall thickness and weight, which is conducive to realizing the thinner and lighter design of display devices.

[0070] This application also relates to a method for preparing an integrated multifunctional brightening film, comprising the following steps; A substrate layer 10 is provided, having opposing first and second surfaces; A light-uniforming functional layer 20 is formed on the first surface of the substrate layer 10, and the light-uniforming functional layer 20 has a patterned structure to define at least one light-transmitting area 201 and one shading area 202. A diffusion functional layer 30 is formed on the second surface of the substrate layer 10; A light-curing adhesive is applied to the surface of the diffusion functional layer 30 on the side away from the substrate layer 10; The light-curing adhesive is pressed using a mold with a prism-shaped pattern; UV light is applied from one side of the uniform light functional layer 20, so that the UV light passes through the patterned structure and irradiates the UV-curable adhesive, causing the UV-curable adhesive to produce non-uniform curing shrinkage in different areas. Demolding forms a prism layer 40 with a height difference morphology on its surface corresponding to the patterned structure of the light-uniforming functional layer 20.

[0071] This application achieves functions such as uniform light distribution, diffusion, brightening, anti-interference and anti-adsorption simultaneously by sequentially forming a light-uniforming functional layer 20, a diffusion functional layer 30 and a prism layer 40 on a single substrate layer 10, and by using a patterned structure to regulate the transmission characteristics of UV light, so that the prism layer 40 forms an irregular morphology with microscopic height differences during the curing process.

[0072] Specifically, the preparation method of the integrated multifunctional brightness enhancement film includes the following steps: Step S1: Provide substrate layer 10; A substrate layer 10 is provided, having opposing first and second surfaces; The substrate layer 10 is preferably made of a transparent polymer optical film material, such as PET (polyethylene terephthalate) film, PC (polycarbonate) film, PMMA (polymethyl methacrylate) film, or other transparent plastic films. The thickness of the substrate layer 10 is preferably controlled between 50 μm and 300 μm.

[0073] In actual production, the substrate layer 10 can be pretreated according to the needs of subsequent coating processes, such as: corona treatment; plasma surface activation treatment; cleaning and dust removal treatment; surface tension adjustment treatment. Through the above pretreatment, the adhesion and coating uniformity between the subsequent functional layer and the substrate layer 10 can be improved.

[0074] Its technical advantages are: by using a transparent flexible substrate as the overall structural carrier, it can simultaneously support multiple functional layers, realize the integrated integration of multifunctional optical structures, thereby reducing the multi-layer film stacking structure in traditional backlight modules, reducing the overall thickness and assembly complexity.

[0075] Step S2: Form the homogenizing functional layer 20; A light-diffusing functional layer 20 is formed on the first surface of the substrate layer 10, and the light-diffusing functional layer 20 has a patterned structure to define at least one light-transmitting area 201 and one shading area 202.

[0076] Furthermore, the step of forming the light-uniforming functional layer 20 includes: Apply white paint and print graphic designs, leaving some areas uncovered to create holes that serve as light-transmitting areas 201; or, A white film is provided, and holes forming the light-transmitting area 201 are pre-punched on the white film. The white film with holes is then attached to the first surface of the substrate layer 10.

[0077] (1) White coating formation method In one embodiment, the light-diffusing functional layer 20 is formed by printing with white paint.

[0078] Specifically, the processing can be carried out through the following methods: screen printing; gravure printing; inkjet printing; microgravure coating; and photolithographic patterning coating.

[0079] The white coating may contain: TiO2 high-reflectivity particles; white resin; inorganic high-reflectivity filler; and optical-grade white pigment.

[0080] During the printing process, graphic design is used to leave some areas uncovered with white paint, thus creating multiple light-transmitting areas 201.

[0081] The light-transmitting area 201 is preferably a hole structure, which can be: a circular hole; an elliptical hole; a polygonal hole; a strip-shaped hole; or an irregular hole.

[0082] (2) White film bonding method In another embodiment, the light-diffusing functional layer 20 may be formed using a pre-fabricated white thin film.

[0083] Specifically, a white optical film is first provided, and holes are formed by mechanical stamping; laser drilling; chemical etching; CNC micro-hole processing.

[0084] Subsequently, a white film with holes is bonded to the first surface of the substrate layer 10 using a bonding process.

[0085] Wherein: the perforated area constitutes the light-transmitting area 201; the white film body constitutes the shading area 202.

[0086] (3) Graphical hole design The multiple holes can be optimized according to the arrangement of the LED light source, and their arrangement patterns include: AM mode: The position of the hole is fixed, while the size of the hole varies regularly.

[0087] For example, a smaller aperture is set closer to the LED area; a larger aperture is set further away from the LED area.

[0088] FM mode: The aperture size remains consistent, but the density of the pore distribution varies regularly.

[0089] For example: reduce the hole density in bright areas; increase the hole density in low-brightness areas.

[0090] AM / FM hybrid mode: Combines aperture and density variations simultaneously to achieve more precise light uniformity control.

[0091] Its technical effect is that, through the design of the patterned light-transmitting area 201, selective transmission and reflection recovery control of LED point light sources can be achieved, so that the light can complete the preliminary light homogenization process before entering the subsequent optical layer, thereby significantly improving the Mini-LED light spot phenomenon and improving the overall brightness utilization rate.

[0092] Step S3: Form the diffusion functional layer 30; A diffusion functional layer 30 is formed on the second surface of the substrate layer 10.

[0093] Furthermore, the step of forming the diffusion functional layer 30 includes: A resin coating containing diffusing particles is applied and cured, wherein the diffusing particles are polymethyl methacrylate particles or other organic or inorganic particles, so that the haze of the diffusing functional layer 30 reaches 30% to 80%.

[0094] Specifically, an optical resin layer containing diffused particles can be formed on the second surface by coating.

[0095] The resin material may include: UV-curable resin; thermosetting acrylic resin; optically transparent resin.

[0096] The diffused particles may include: PMMA polymer microspheres; silica microspheres; polystyrene microspheres.

[0097] The particle size of the diffused particles is preferably 1 μm to 10 μm.

[0098] After the diffusion particles are added, the diffusion layer is formed through the following methods: doctor blade coating; micro-recessed coating; slot coating; spraying.

[0099] The following steps are then performed: UV curing; thermal curing; double curing.

[0100] The final diffuser layer 30 is formed, and its haze is preferably controlled between 30% and 80%.

[0101] The technical effect is that the diffusion layer 30 can perform secondary scattering and diffusion of the light after passing through the uniform light layer 20, thereby further improving the uniformity of light output and reducing local bright spots. At the same time, by controlling the haze of the diffusion layer, a good balance can be achieved between brightness and uniformity.

[0102] Step S4: Apply UV-curable adhesive; A light-curing adhesive is applied to the surface of the diffusion functional layer 30 on the side away from the substrate layer 10.

[0103] Specifically, the following methods can be used: slot coating; gravure coating; doctor blade coating; and precision roll coating.

[0104] The photocurable adhesive is preferably a UV-curable resin, which has the following characteristics: high transparency; good flowability; low shrinkage; and good mold replication performance.

[0105] The thickness of the adhesive layer can be adjusted according to the height of the prism structure.

[0106] Its technical effect is that by uniformly coating the light-curing adhesive, a stable material foundation can be provided for the subsequent replication of the prism structure, and the forming accuracy of the prism structure can be guaranteed.

[0107] Step S5: Prism die is rolled into shape; The light-curing adhesive is rolled using a mold with a prism-shaped pattern.

[0108] The mold may be: a metal mold; a nickel mold; a quartz mold; or a flexible embossing mold.

[0109] The prism structure can be: a prism of equal height; a prism of unequal height; a dithering prism; or a non-dithering prism.

[0110] During the rolling process, the prism mold replicates the prism shape onto the surface of the photocurable adhesive layer.

[0111] Its technical effect is that, through high-precision molding process, a prism structure with good optical converging ability can be formed, which improves the brightness of the display in the front viewing direction.

[0112] Step S6: UV patterning and curing; UV light is applied from one side of the uniform light functional layer 20, so that the UV light passes through the patterned structure and irradiates the UV-curable adhesive.

[0113] Because the uniform light layer 20 has: a fully transparent perforated area; and a partially transparent or reflective white shielding area 202, UV light will form a patterned light intensity distribution after passing through it.

[0114] Different regions have different UV energies, resulting in different photocuring reaction rates, different adhesive layer shrinkage rates, and different cured thicknesses. Ultimately, this causes the prism layer 40 to form a height difference morphology corresponding to the patterned structure of the homogenizing functional layer 20.

[0115] Its technical effect is that: this application utilizes the patterned structure of the light-diffusing layer itself to directly induce the prism layer 40 to form an irregular surface morphology, without the need for additional etching or embossing processes, and can simultaneously obtain anti-interference and anti-adsorption functions.

[0116] Step S7: Demolding to form prism layer 40; After the light curing is complete, separate the prism mold from the light-cured adhesive layer and demold it.

[0117] After demolding, a prism layer 40 with a patterned height difference morphology is formed.

[0118] Among them, the height difference structure can disrupt the regular optical cycle; microscopic height changes can reduce the contact area of ​​the film layer.

[0119] Its technical effects are: reducing Newton's rings and interference fringes, improving display quality; reducing adsorption problems between film layers, improving the convenience of winding, handling and assembly; and simultaneously achieving multi-functional integrated effects such as uniform light, diffusion, brightening, anti-interference and anti-adsorption, truly forming an all-in-1 optical brightening film structure.

[0120] This application also has the following beneficial effects: 1. Anti-interference effect: Traditional regular prism structures are prone to forming periodic optical interference with the display panel or glass cover, resulting in Newton's rings or interference fringes. However, this application can effectively disrupt the regular optical cycle by forming an irregular height difference structure, reducing visual interference problems and improving the display quality. 2. Anti-adsorption effect: Traditional equal-height prism layers are prone to adsorption due to large-area contact, making it difficult to separate the film, difficult to assemble, or even damage the surface. However, this application reduces the actual contact area between the film layers through the height difference structure, which can effectively reduce film adsorption and improve the convenience of product handling and assembly. 3. Functional integration effect: The patterned structure of the light-uniformation functional layer 20 itself directly induces the prism layer 40 to form a corresponding irregular shape. Without the need for additional anti-interference or anti-adsorption processing steps, multiple functions such as light uniformity, diffusion, brightening, anti-interference and anti-adsorption can be obtained at the same time, realizing a true all-in-1 integrated optical film structure.

[0121] The following examples further illustrate this point: In the following embodiments, the substrate layer 10 uses 50µm PET as the substrate, and a mini-LED backlight is used as the result evaluation system. The brightness and shadow blocking effect of the optical film on the light source, the uniformity of the image, and the optical brightness are observed after the optical film is assembled.

[0122] All embodiments must comply with the microstructure setting conditions of this invention: Example 1 The prism layer 40 is an isosceles right triangle with a base width of 70 μm, continuously and closely arranged; the haze of the diffusion layer is 40%; the light-diffusing layer is an uncoated area with a diameter of 1 mm and arranged in FM mode.

[0123] At this point, the test results of the brightness enhancement film are as follows: the light and shadow blocking effect on the LED light source is that the LED light spot is invisible; the screen uniformity is that the brightness is slightly uneven, there are no interference fringes, and the brightness ratio is 115%.

[0124] Example 2 The difference between Example 2 and Example 1 is that the haze of the diffusion layer is 80%.

[0125] At this point, the test results of the brightness enhancement film are as follows: the light and shadow blocking effect on the LED light source is that the LED light spot is invisible, the screen uniformity is uniform without interference stripes, and the brightness ratio is 106%.

[0126] Example 3 The difference between Example 3 and Example 1 is that the uniform light layer is an uncoated area that is circular with a diameter of 0.5-3mm and arranged in AM mode.

[0127] At this point, the test results of the brightness enhancement film are as follows: the light and shadow blocking effect on the LED light source is that the LED light spot is invisible; the screen uniformity is that the brightness is slightly uneven, there are no interference fringes, and the brightness ratio is 119%.

[0128] Example 4 The difference between Example 4 and Example 1 is that the haze of the diffusion layer is 80%; the uniform light layer is an uncoated area with a diameter of 0.5-3mm in a circular shape, arranged in AM mode.

[0129] At this point, the test results of the brightness enhancement film are as follows: the light and shadow blocking effect on the LED light source is that the LED light spot is invisible, the screen uniformity is uniform without interference stripes, and the brightness ratio is 110%.

[0130] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that, from top to bottom, they are: a top diffusion film, a brightening film, and a diffusion plate, which are stacked together.

[0131] At this point, the test results of the brightness enhancement film are as follows: the light and shadow blocking effect on the LED light source is that the LED light spot is invisible, the screen uniformity is uniform without interference stripes, and the brightness ratio is 100%.

[0132] The results of each embodiment and comparative example are shown in Table 1: Table 1 The test results above show that: As can be seen from Examples 1-4 and Comparative Example 1, the main light-uniforming effect of this application comes from the perforated light-uniforming layer. Since the light-uniforming layer is made of white paint, light that does not pass through the openings will be recycled by reflection, greatly reducing the light loss obtained by the high-haze diffuser plate. Therefore, the brightness of all examples is significantly improved.

[0133] In the embodiments, it can be seen that the haze of the diffusion layer will also affect the overall brightness and image uniformity, and can be optimized and matched by the design of the haze of the diffusion layer and the light transmission area of ​​the uniform light layer.

[0134] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. An integrated multifunctional brightening film, characterized in that, include: A substrate layer (10) has opposing first and second surfaces; A light-diffusing functional layer (20) is disposed on the first surface of the substrate layer (10). The light-diffusing functional layer (20) has a patterned structure to form at least one light-transmitting area (201) through which light can be fully transmitted and a light-reflecting shielding area (202). A diffusion functional layer (30) is disposed on the second surface of the substrate layer (10); and A prism layer (40) is disposed on the side surface of the diffusion functional layer (30) away from the substrate layer (10); The surface of the prism layer (40) has a height difference morphology corresponding to the patterned structure of the light-uniforming functional layer (20) to provide anti-interference and anti-adsorption functions.

2. The integrated multifunctional brightening film according to claim 1, characterized in that, The light-diffusing functional layer (20) is a white coating or white film with pores; Wherein, when the coating is white, the light-transmitting area (201) is a hole without coating formed by patterned coating; When the film is white, the light-transmitting area (201) is a hole formed by stamping, and the body of the white film constitutes the shielding area (202).

3. The integrated multifunctional brightening film according to claim 1 or 2, characterized in that, The light-transmitting area (201) consists of multiple holes, and the arrangement of the multiple holes is AM mode, FM mode or AM / FM mixed mode; In the AM mode, the positions of the multiple holes are fixed, and the size of at least some of the holes exhibits a regular variation. The FM mode is characterized by a fixed size of multiple holes, and their distribution density on the light-uniforming functional layer (20) exhibits a regular variation.

4. The integrated multifunctional brightening film according to claim 1, characterized in that, The diffusion functional layer (30) is formed by curing a resin coating containing diffusion particles, and the haze of the diffusion functional layer (30) is 30% to 80%.

5. The integrated multifunctional brightening film according to claim 4, characterized in that, The light-diffusing particles of the diffusion functional layer (30) are at least one of PMMA polymer and inorganic silicon dioxide, and their particle size is 1μm~10μm.

6. The integrated multifunctional brightening film according to claim 1, characterized in that, The prism structure of the prism layer (40) is a linear prism structure, selected from any one of equal-height prisms, unequal-height prisms, dithering prisms, or non-dithering prisms.

7. The integrated multifunctional brightening film according to claim 1, characterized in that, The substrate layer (10) is one of PET film, PC film, PMMA film or transparent plastic film, and its thickness is 50μm to 300μm.

8. A method for preparing an integrated multifunctional brightening film, characterized in that, Includes the following steps; A substrate layer (10) is provided, having opposing first and second surfaces; A light-diffusing functional layer (20) is formed on the first surface of the substrate layer (10), and the light-diffusing functional layer (20) has a patterned structure to define at least one light-transmitting area (201) and one shading area (202). A diffusion functional layer (30) is formed on the second surface of the substrate layer (10); A light-curing adhesive is applied to the surface of the diffusion functional layer (30) on the side away from the substrate layer (10); The light-curing adhesive is pressed using a mold with a prism-shaped pattern; UV light is applied from one side of the uniform light functional layer (20), so that the UV light passes through the patterned structure and irradiates the UV-curable adhesive, causing the UV-curable adhesive to produce non-uniform curing shrinkage in different areas. Demolding forms a prism layer (40) with a height difference morphology on its surface corresponding to the patterned structure of the light-diffusing functional layer (20).

9. The preparation method according to claim 8, characterized in that, The steps for forming the homogenizing functional layer (20) include: Apply white paint and print graphic designs, leaving some areas uncovered to create holes that act as light-transmitting areas (201); or, A white film is provided, and holes forming the light-transmitting area (201) are pre-stamped on the white film. The white film with holes is then attached to the first surface of the substrate layer (10).

10. The preparation method according to claim 8, characterized in that, The steps for forming the diffusion functional layer (30) include: A resin coating containing diffusing particles is applied and cured, wherein the diffusing particles are polymethyl methacrylate particles or other organic or inorganic particles, so that the haze of the diffusing functional layer (30) reaches 30% to 80%.

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