Light diffusion type antireflection film

Abstract

The utility model discloses a light diffusion type anti-reflection film, it includes transparent substrate and multilayer scattering structure. Transparent substrate has opposite first surface and second surface. Multilayer scattering structure sets up at the first surface. Multilayer scattering structure includes first scattering layer, second scattering layer and third scattering layer. Second scattering layer is stacked above first scattering layer, and third scattering layer is stacked above second scattering layer. Second scattering layer has a first interface of facing first scattering layer, and a second interface of facing third scattering layer, and the first interface and the second interface present asymmetric and non-uniform distribution's undulating profile. By this, the utility model reached excellent and stable diffusion and anti-reflection effect.

Description

Technical Field

[0001] This utility model relates to an optical film, and more particularly to a light-diffusing anti-reflective film. Background Technology

[0002] Current display technology is moving towards higher pixel densities, which places higher performance demands on the optical film structures used in display panels, such as anti-glare films (AG films) and anti-reflection films (AR films). Traditional anti-glare films often use methods such as sandblasting or molding to roughen the surface of a transparent substrate, controlling light scattering behavior through haze (haze refers to the percentage of scattered light flux deviating from the incident light direction when light passes through a transparent or translucent material compared to the total transmitted light flux). However, if the haze is too low, it may produce glare; conversely, if the haze is too high, it can easily lead to decreased image contrast and uneven dynamic scattering, affecting image quality. Another type of anti-glare film involves coating a transparent substrate with a layer containing inorganic particles, which creates a scattering effect through the microstructure formed by the particles. However, this method is often accompanied by problems such as uneven brightness distribution and severe light loss.

[0003] On the other hand, traditional anti-reflective films are usually formed by sputtering or wet coating to form a multi-layer interference structure. Although they have excellent anti-reflective properties, such processes are expensive, complicated, and have poor adhesion between the film and the substrate, which is not conducive to long-term use and mass production.

[0004] In other words, existing optical film structures, whether anti-glare or anti-reflective, have room for improvement in terms of optical performance and cost control. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a light-diffusing anti-reflective film to address the shortcomings of the prior art.

[0006] To address the aforementioned technical problems, one technical solution adopted by this utility model is to provide a light-diffusing anti-reflective film, which includes a transparent substrate and a multilayer scattering structure. The transparent substrate has a first surface and a second surface facing each other. The multilayer scattering structure is disposed on the first surface. The multilayer scattering structure includes a first scattering layer, a second scattering layer, and a third scattering layer. The second scattering layer is stacked on top of the first scattering layer, and the third scattering layer is stacked on top of the second scattering layer. The second scattering layer has a first interface facing the first scattering layer and a second interface facing the third scattering layer, and the first interface and the second interface exhibit an asymmetrical and non-uniformly distributed wavy profile.

[0007] Preferably, the first interface of the second scattering layer is in contact with the first scattering layer, the second interface of the second scattering layer is in contact with the third scattering layer, and the refractive index difference between the first scattering layer and the second scattering layer, and the refractive index difference between the second scattering layer and the third scattering layer are greater than or equal to 0.1.

[0008] Preferably, the upper surface of the first scattering layer is a prism surface, a pyramid surface, a wavy surface, or a circular arc surface.

[0009] Preferably, the average amplitude of the first interface or the second interface of the second scattering layer is between 0.1 μm and 10 μm, wherein the average amplitude is defined as follows: on the cross-sectional contour line of the first interface or the second interface, select several pairs of corresponding local highest points and adjacent local lowest points, calculate the height difference between each pair, and use the average value of the multiple height differences as the average amplitude.

[0010] Preferably, the thickness of the second scattering layer can be divided into multiple wide thickness regions and multiple narrow thickness regions, and the multiple wide thickness regions and multiple narrow thickness regions are randomly distributed within the thickness range; wherein, the average thickness of the wide thickness regions is between 5 μm and 20 μm, and the average thickness of the narrow thickness regions is between 0.1 μm and 5 μm; wherein, the thickness of the second scattering layer is defined as the distance between the first interface and the second interface.

[0011] Preferably, the plurality of wide thickness regions and the plurality of narrow thickness regions do not overlap with each other in an orderly manner.

[0012] Preferably, when the third scattering layer is the outermost layer of the multilayer scattering structure, the ten-point average roughness (Rz) of the outer surface of the third scattering layer is between 0.1 μm and 10 μm.

[0013] Preferably, when the third scattering layer is the top layer of the multilayer scattering structure, the outer surface of the third scattering layer is a flat surface, a pyramid, a prism, a wavy surface, or an arc surface.

[0014] Preferably, the light-diffusing antireflective film further includes an optical functional layer disposed on the second surface of the transparent substrate.

[0015] Preferably, the outer surface of the optical functional layer is a pyramid, a prism, a wavy surface, or a circular arc surface.

[0016] Preferably, the outer surface of the optical functional layer is an asymmetrical and non-uniform wavy surface.

[0017] Preferably, the optical functional layer comprises black optical resin.

[0018] One of the beneficial effects of this invention is that the light-diffusing anti-reflective film F provided by this invention adopts a multi-layer scattering structure with at least three layers, and in this multi-layer scattering structure, the refractive indices of adjacent scattering layers are different. Therefore, through the technical feature in the multi-layer scattering structure that "the second scattering layer 2 has a first interface facing the first scattering layer and a second interface facing the third scattering layer, and the first and second interfaces exhibit an asymmetrical and non-uniformly distributed wavy profile," this invention enables light passing through the light-diffusing anti-reflective film to diffuse uniformly without reducing brightness.

[0019] Compared to traditional diffusion films that require precise alignment and bonding to avoid interference patterns or Mohr fringes, the multi-layer scattering structure used in this invention has an asymmetrical and disordered wave-like profile, which allows light to generate diffusion paths at multiple angles and directions in the multi-layer scattering layers. This not only reduces ambient light crosstalk and optical loss, but more importantly, it achieves excellent and stable diffusion and anti-reflection effects without the need for strict alignment and bonding during the manufacturing process.

[0020] To further understand the features and technical content of this utility model, please refer to the following detailed description and drawings of this utility model. However, the drawings provided are for reference and illustration only and are not intended to limit this utility model. Attached Figure Description

[0021] Figure 1 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the first embodiment of this utility model.

[0022] Figure 2 This is a schematic diagram showing the processing direction of the light-diffusing anti-reflective film of this utility model during its manufacturing process.

[0023] Figure 3 This is a cross-sectional schematic diagram of another state of the light-diffusing anti-reflective film according to the first embodiment of this utility model.

[0024] Figure 4 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the second embodiment of this utility model.

[0025] Figure 5 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the third embodiment of this utility model.

[0026] Figure 6 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the fourth embodiment of this utility model.

[0027] Figure 7 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the fifth embodiment of this utility model.

[0028] Figure 8 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the sixth embodiment of this utility model.

[0029] Figure 9 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the seventh embodiment of this utility model. Detailed Implementation

[0030] The following specific embodiments illustrate the implementation of the "light-diffusing anti-reflective film" disclosed in this utility model. Those skilled in the art can understand the advantages and effects of this utility model from the content disclosed in this specification. This utility model can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this utility model. Furthermore, the accompanying drawings of this utility model are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of this utility model in detail, but the disclosed content is not intended to limit the scope of protection of this utility model.

[0031] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components, these components should not be limited by these terms. These terms are primarily used to distinguish one component from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more related listed items.

[0032] First Embodiment

[0033] See Figure 1 As shown, Figure 1 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the first embodiment of the present invention. The present invention provides a light-diffusing anti-reflective film F, which mainly includes: a multilayer scattering structure and a transparent substrate 6. The transparent substrate 6 has a first surface 61 and a second surface 62 facing each other. The multilayer scattering structure is disposed on the first surface 61, and the number of scattering layers in the multilayer scattering structure is at least three, preferably three to five layers. Each scattering layer is a light-transmitting material. For example, each scattering layer can use materials commonly found in anti-glare films (AG films) or anti-reflection films (AR films), such as polymethyl methacrylate (PMMA), polycarbonate (PC), or styrene-based polymers as the substrate, mixed with scattering inorganic particles such as titanium dioxide (TiO2), silicon dioxide (SiO2), or barium sulfate (BaSO4). The transparent substrate 6 is made of polyethylene terephthalate (PET) or polycarbonate (PC). The present invention is not limited to the materials of the scattering layers and the transparent substrate 6.

[0034] In this invention, adjacent scattering layers have different refractive indices; specifically, the refractive index difference between adjacent scattering layers is greater than or equal to 0.1. By configuring materials with different refractive indices, a graded refractive index structure is formed in the thickness direction of the multilayer scattering structure, causing light to undergo multiple refractions and scatterings during transmission. This produces a significant multiple scattering effect, effectively improving light diffusion performance, suppressing reflection and light spot phenomena, and further enhancing anti-reflection and visual uniformity.

[0035] For example, such as Figure 1 As shown, in the first embodiment, the multilayer scattering structure is a three-layer structure, including a first scattering layer 1, a second scattering layer 2, and a third scattering layer 3. The first scattering layer 1 is disposed on the first surface 61 of the transparent substrate 6, the second scattering layer 2 is stacked on top of the first scattering layer 1, and the third scattering layer 3 is stacked on top of the second scattering layer 2. The second scattering layer 2 has a first interface B1 facing the first scattering layer 1 and a second interface B2 facing the third scattering layer 3. The first interface B1 and the second interface B2 exhibit an asymmetrical and non-uniformly distributed wavy profile. More specifically, the first interface B1 of the second scattering layer 2 is in contact with the first scattering layer 1, and the second interface B2 of the second scattering layer 2 is in contact with the third scattering layer 3. The refractive index difference between the first scattering layer 1 and the second scattering layer 2, and the refractive index difference between the second scattering layer 2 and the third scattering layer 3, are greater than or equal to 0.1.

[0036] The first interface B1 and the second interface B2 exhibit an asymmetrical and non-uniform wavy profile. In this invention, the average amplitude of the first interface B1 or the second interface B2 of the second scattering layer 2 is between 0.1 μm and 10 μm. It should be noted that the average amplitude referred to here is defined as the average amplitude obtained by selecting several pairs of corresponding local highest points and adjacent local lowest points along the cross-sectional profile of the first interface B1 or the second interface B2, calculating the height difference between each pair, and using the average of these height differences. Taking the first interface B1 as an example, five pairs of corresponding local highest points and adjacent local lowest points are selected along the cross-sectional profile of the first interface B1, for example, five local highest points and five local lowest points. The height difference between each pair is calculated, and the average of these height differences is used as the average amplitude. Furthermore, the thickness of the second scattering layer 2, i.e., the distance between the first interface B1 and the second interface B2, can be divided into multiple wide-thickness regions W1 and multiple narrow-thickness regions W2. Multiple wide-thickness regions W1 and multiple narrow-thickness regions W2 are randomly distributed within the thickness range, and the wide-thickness regions W1 and the narrow-thickness regions W2 do not overlap with each other in an orderly manner. The average thickness of the wide-thickness regions W1 is between 5 μm and 20 μm, and the average thickness of the narrow-thickness regions W2 is between 0.1 μm and 5 μm.

[0037] The upper surface of the first scattering layer 1 (in the first embodiment, i.e.) Figure 1 The first interface B1 in the first scattering layer 1 can be a prism-shaped surface, a pyramid-shaped surface, a wavy surface, or an arc surface; this invention is not limited to any of these. For example, the upper surface of the first scattering layer 1 can be an asymmetrical and non-uniform wavy surface. Or, as... Figure 3 In another state shown, the upper surface of the first scattering layer 1 is a prism, from Figure 3 From a cross-sectional perspective, it is a serrated surface composed of multiple rhomboid structures.

[0038] See Figure 2 , Figure 2 This is a schematic diagram of the processing direction during the fabrication of the light-diffusing anti-reflective film of this utility model. During fabrication, the rolled light-diffusing anti-reflective film F is extended along a processing direction D and cut into multiple segments. The outer surface 31 of the third scattering layer 3 is non-flat, exhibiting a curved texture structure extending along a predetermined direction. The ten-point average roughness (Rz) of the outer surface 31 is between 0.1 μm and 10 μm, and the predetermined direction is the processing direction D of the light-diffusing anti-reflective film F in the process. Viewed from a top angle, the curved texture structure of the third scattering layer 3 exhibits an irregular flowing water pattern (not shown in the figure); while observing the cross-section of the third scattering layer 3, the curved texture structure exhibits an asymmetrical and non-uniform uneven morphology (see...). Figure 1 ).

[0039] It is worth noting that many of the aforementioned curved texture structures are microstructures, with characteristic scales typically ranging from hundreds of nanometers to tens of micrometers, requiring magnification using optical or electron microscopes to be clearly identified. The design of these microstructures helps improve the light diffusion performance of the film while suppressing reflected glare and enhancing display quality.

[0040] Furthermore, the multi-layer scattering structure employed in this invention allows some light to undergo multiple weak scatterings between different layer interfaces, thereby producing a higher-order small-angle scattering effect. This scattering phenomenon is known as soft diffusion in optical film applications. Compared to the strong diffusion formed by traditional single-layer diffusion films, soft diffusion does not produce obvious hard shadows, but rather blurs the edges of object contours, producing a soft light effect and improving visual comfort. This soft diffusion phenomenon can evenly disperse strong light, effectively reducing viewer discomfort and improving color uniformity and image contrast, while avoiding significant brightness attenuation. In addition, soft diffusion can flatten the brightness distribution of the light source, creating a natural transition between bright and dark areas, which helps to improve the overall image layering and quality, making it particularly suitable for applications such as LCD and OLED displays, backlight modules, and lighting equipment.

[0041] In this invention, the haze range of the light-diffusing antireflective film is preferably 3% or higher and lower than 60%, more preferably 5% or higher and lower than 20%. Controlling the haze value has a crucial impact on the performance of the optical film; excessively low haze may cause glare, while excessively high haze may cause image blurring and brightness loss. Although a common haze range of approximately 10% to 80% is relatively easy to achieve, to simultaneously ensure both anti-glare effect and clarity, this invention preferably adopts a haze design of less than 20% but higher than 5%, and achieves this range through the refractive index difference and microstructure control of the multilayer scattering materials.

[0042] For example, when the light-diffusing anti-reflective film of this utility model is applied to a backlight module, that is, as a diffuser film for a backlight module, the light is incident from the second surface 62 where the transparent substrate 6 is located, and the light penetrates the multi-layer scattering structure, and then generates multiple scattering through the interface of different refractive index layers and microstructures, making the emitted light softer and more uniform, thereby effectively eliminating the phenomenon of concentrated sparkle or bright spot, and improving the overall brightness uniformity of the panel.

[0043] In another embodiment (such as) Figure 8Light can also enter from the first surface 61 of the transparent substrate 6, first penetrating the multilayer scattering structure disposed above the first surface 61. Through the multiple weak scattering caused by the difference in refractive index between the layers and the non-uniform wavy interfaces B1 and B2, the light can form a uniformly diffused light. Subsequently, the diffused light passes through the optical functional layer 7 (e.g., the brightness enhancement structure 71) disposed on the second surface 62 of the transparent substrate 6, which can further provide a composite optical effect of diffusion and brightness enhancement.

[0044] On the other hand, when the light-diffusing anti-reflective film of this invention is used as an anti-glare and anti-reflective film (e.g., attached to the surface of displays such as micro LED, mini LED, OLED, and LCD), when the user views the screen from above, the incident light will first contact the outermost layer of the multi-layer scattering structure (in... Figure 1 and Figure 3 In this embodiment, the outermost layer is a third scattering layer 3 with a rough textured outer surface 31. The combined effect of its surface unevenness and refractive index difference causes most light to be scattered or suppressed by reflection, significantly reducing ambient glare and crosstalk, thus improving reading and viewing clarity. The diffusion of light through multiple layers of disordered microstructures avoids interference between the microstructures and the high-resolution display, and reduces moiré patterns without increasing haze.

[0045] In another embodiment, the light-diffusing anti-reflective film of this invention can also be applied to the display surface structure of televisions or large display devices. Through a multi-layer scattering layer structure and microstructure surface design, this invention can exhibit relatively high reflectivity in a specific wavelength region (e.g., red light wavelength greater than 650nm), while simultaneously providing excellent light diffusion and anti-reflection characteristics in the visible light range. When applied to a display surface, it can effectively diffuse light from the display light source, resulting in a soft and uniform light distribution effect, and reducing crosstalk caused by ambient light, further improving image quality and contrast clarity.

[0046] Furthermore, even though the light-diffusing anti-reflective film of this invention possesses excellent scattering capabilities, laser pointers (such as red laser pointers) can still be directly projected onto the film surface (e.g., the outer surface 31 of the third scattering layer 3) without the light spot disappearing due to absorption by the polarizing material. Conversely, thanks to its moderate scattering characteristics, the laser spot will produce a visual expansion effect on the film surface, making the originally small red dot appear larger and clearer, improving the recognizability and practicality during presentations, demonstrations, or interactive operations. In addition, adding an appropriate amount of black particles to the scattering layer structure can further suppress background reflection and enhance the contrast effect. Especially when this invention adopts a five-layer scattering structure, the scattering and anti-reflection performance will be more significant, making it suitable for high-contrast and high-resolution display applications.

[0047] It should also be noted that the materials constituting the multilayer scattering layers (e.g., the first to fifth scattering layers) of this invention include high-refractive-index materials and low-refractive-index materials. The refractive index range of the high-refractive-index materials is approximately 1.56 to 1.70, while that of the low-refractive-index materials is approximately 1.40 to 1.55. Although the refractive index difference between the layers in this invention can improve the scattering effect, there is no limitation on the refractive index difference between high- and low-refractive-index materials, which can be adjusted according to actual design requirements, but the refractive index difference must be at least 0.1.

[0048] Second Embodiment

[0049] See Figure 4 As shown, Figure 4 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the second embodiment of this utility model. Figure 4 The light-diffusing anti-reflective film structure shown is the same as that in the first embodiment ( Figure 1 The second embodiment is similar to the first embodiment (i.e., the multilayer scattering structure is based on a three-layer scattering structure, with the first scattering layer 1 as the bottom layer and the third scattering layer 3 as the outermost layer), and the similarities will not be elaborated further. The main difference between the second embodiment and the first embodiment is that the outermost surface of the multilayer scattering structure, that is, the outer surface 31 of the third scattering layer 3, can be a flat surface, a prism surface, a pyramidal surface, a wavy surface, or an arc surface; this utility model is not limited to these. Figure 4 In the second embodiment, the outer surface 31 of the third scattering layer 3 can be a relatively flat surface with a ten-point average roughness (Rz) of less than 0.5 μm. Compared to the outer surface with obvious curved texture in the first embodiment, the flat outer surface design in this embodiment helps to further reduce the interface reflectivity and improve the overall transmittance of the light-diffusing antireflective film F.

[0050] Specifically, the flat outer surface reduces light scattering and multiple reflections at the interface between the air and the film, thus achieving an anti-reflective effect. Simultaneously, the extremely low surface roughness of the outer surface 31 improves the linear transmission efficiency of light flux, achieving high light transmittance, making it suitable for display devices with high requirements for brightness and image clarity. This design is also particularly suitable for automotive projection film applications (such as HUD head-up displays or windshield display systems). When light emitted from a backlight source below (such as projection light in an automotive display module) passes through the light-diffusing anti-reflective film provided by this invention, it can be efficiently transmitted to the display interface via the low-roughness outer surface, further ensuring good image clarity and sufficient brightness, improving the overall user visual experience and driving safety.

[0051] Third Embodiment

[0052] See Figure 5 As shown, Figure 5 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the third embodiment of this utility model. Figure 5 The light-diffusing anti-reflective film structure shown is the same as that in the first embodiment ( Figure 1 The similarities are similar and will not be elaborated further. The main difference between the third embodiment and the first embodiment is that, in Figure 5 In the light-diffusing antireflective film F, the multilayer scattering structure includes a first scattering layer 1, a second scattering layer 2, a third scattering layer 3, a fourth scattering layer 4, and a fifth scattering layer 5. The first to fifth scattering layers are stacked sequentially from bottom to top, with the first scattering layer 1, disposed on the first surface 61, being the bottom layer and the fifth scattering layer 5 being the outermost layer. The outermost surface of the multilayer scattering structure is the outer surface 51 of the fifth scattering layer 5. Figure 5 The outermost outer surface 51 is a flat surface, but this utility model is not limited to it. In practice, it can also be a prism surface, a pyramidal surface, a wavy surface or an arc surface, preferably a wavy surface.

[0053] The five-layer scattering design further enhances the multiple scattering effect of light within the film, allowing transmitted light to undergo more refraction and diffusion paths between layers. This effectively improves the uniformity and directionality of light diffusion, achieving a softer and more delicate flexible diffusion effect. Compared to a three-layer structure, the five-layer design provides higher-order small-angle scattering, helping to eliminate local bright spots, reduce the hardness of light source boundaries, and improve the overall consistency and visual comfort of the image.

[0054] Fourth embodiment

[0055] See Figure 6 As shown, Figure 6 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the fourth embodiment of this utility model. Figure 6The light-diffusing anti-reflective film structure shown is the same as that in the first embodiment ( Figure 1 The similarities are not elaborated here. The main difference between the third embodiment and the first embodiment is that the light-diffusing anti-reflective film F further includes an optical functional layer 7, disposed on the second surface 62 of the transparent substrate 6. The optical functional layer 7 can be a flat surface, a prism surface, a pyramidal surface, a wavy surface, or an arc surface, and this utility model is not limited thereto. Figure 6 In the optical functional layer 7, the outer surface 71 is a wavy surface with an asymmetrical and non-uniformly distributed uneven structure. The ten-point average roughness (Rz) of the outer surface 71 can be controlled between 0.1 μm and 10 μm.

[0056] The design of the optical functional layer 7 effectively enhances the light scattering effect, further improving the overall light diffusion capability of the light-diffusing anti-reflective film F. For example, when applied to a display backlight module, light typically enters from below the backlight source, first passing through the optical functional layer 7 on the second surface 62, then entering the transparent substrate 6, and finally ascending to each scattering layer (such as the first, second, and third scattering layers), exiting from the outer surface 31 of the third scattering layer 3 towards the user's line of sight. In this application scenario, the optical functional layer 7 provides further diffusion processing for the light penetrating the transparent substrate 6 from below, resulting in more uniform and softer light emission. Simultaneously, this design also helps reduce high-angle reflections, thereby improving overall display quality and visual comfort.

[0057] However, this invention does not limit the incident direction of light. In other embodiments, light can also enter from above, that is, first pass through a multi-layer scattering structure (e.g., a third scattering layer 3, a second scattering layer 2, and a first scattering layer 1), then pass through the transparent substrate 6, and finally exit through the optical functional layer 7 disposed on the second surface 62. Under this optical path configuration, the optical functional layer 7 can still regulate the emitted light through its surface structure design (e.g., a wavy surface, a pyramidal surface, a prism surface, or an arc surface) to produce different optical effects, such as guiding light to increase brightness (brightness enhancement), diffusing the light field to achieve uniform light emission (uniform light), or suppressing glare and reflection crosstalk. In other words, regardless of whether the light penetrates the film layer from top to bottom or bottom to top, this invention can effectively achieve the required composite optical functions through the structural configuration and contour characteristics of the optical functional layer, further improving the overall application flexibility and optical performance of the film layer.

[0058] Fifth Embodiment

[0059] See Figure 7 As shown, Figure 7 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the fifth embodiment of this utility model. Figure 7 The light-diffusing anti-reflective film structure shown is the same as that in the first embodiment ( Figure 1The similarities are similar and will not be elaborated further. The main difference between the fifth embodiment and the first embodiment is that, in Figure 6 In the light-diffusing antireflective film F, an optical functional layer 7 is further included, disposed on the second surface 62 of the transparent substrate 6. The outer surface 71 of the optical functional layer 7 is an arc surface, presenting a concave-convex lens structure formed by a regular arrangement of multiple arc structures, and has smooth height variation characteristics.

[0060] For example, when applied to a display backlight module, light from the lower backlight source first passes through the optical functional layer 7, then travels upwards through the transparent substrate 6 to each scattering layer, and finally exits from the outer surface 31 of the third scattering layer 3. The arc-shaped surface design of the outer surface 71 of the optical functional layer 7 helps diffuse the incident light from below, improving overall diffusion efficiency. Furthermore, compared to sharp or randomly rough structures, the arc-shaped concave-convex contour maintains uniform light emission while diffusing, effectively reducing problems such as light spots, uneven brightness, or interference fringes, achieving a better uniform light effect.

[0061] On the other hand, in other embodiments, if the light source enters from the direction of the multilayer scattering structure, the light first passes through the multilayer scattering structure with a gradient refractive index and interface microstructure, generating a uniform light diffusion effect. Subsequently, the optical functional layer 7 (e.g., a concave-convex lens structure arranged in an arc) disposed on the second surface 62 of the transparent substrate 6 further controls the light field, achieving functions such as light focusing, light guiding, or refraction in a specific direction. In other words, different incident light directions can be used to achieve different optical characteristic requirements.

[0062] Sixth Embodiment

[0063] See Figure 8 As shown, Figure 8 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the sixth embodiment of this utility model. Figure 8 The light-diffusing anti-reflective film structure shown is the same as that in the first embodiment ( Figure 1 The similarities are similar and will not be elaborated further. The main difference between the sixth embodiment and the first embodiment is that, in Figure 8 In the light-diffusing antireflective film F, an optical functional layer 7 is further included, disposed on the second surface 62 of the transparent substrate 6. The outer surface 71 of the optical functional layer 7 has a prism-like structure, which is formed by a regular arrangement of rhomboid structures, with periodically arranged sharp corners and bevels.

[0064] This design is particularly suitable for LCD backlight modules (BLU), optical light guide plates, solar energy collection systems, and various lighting devices. The composite structure employed in this embodiment combines light diffusion and light guidance functions. Through a multi-layered scattering structure, it initially diffuses and homogenizes the light from the light source, thereby compensating for any brightness unevenness that may occur during the focusing process of the prism-shaped optical functional layer 7. This design achieves a comprehensive optical effect of simultaneously improving brightness, maintaining light uniformity, and controlling the directionality of light. Furthermore, in automotive optical systems, the optical functional layer 7 can not only effectively eliminate hot spots and improve glare, but also adjust the light emission direction through the arrangement angle of the prism (or sawtooth) structure, concentrating the light onto the driver's line-of-sight, thus significantly improving the brightness and clarity of the projected image and achieving excellent display effects and driving safety.

[0065] Seventh Embodiment

[0066] See Figure 9 As shown, Figure 9 This is a cross-sectional schematic diagram of the light-diffusing anti-reflective film according to the seventh embodiment of this utility model. Figure 9 The light-diffusing anti-reflective film structure shown is the same as that in the first embodiment ( Figure 1 The similarities are similar and will not be elaborated further. The main difference between the seventh embodiment and the first embodiment is that, in Figure 8 In this process, the light-diffusing anti-reflective film F further includes an optical functional layer 7 disposed on the second surface 62 of the transparent substrate 6. The optical functional layer 7 is a privacy protection structure layer, which includes a plurality of staggered light-absorbing regions 701 and light-transmitting regions 702. The light-absorbing regions 701 are made of black optical resin and are used to absorb light from a specific direction; while the light-transmitting regions 702 are made of transparent or translucent optical resin and allow light from a normal viewing angle to pass through.

[0067] like Figure 9 As shown, the light-absorbing area 701 and the light-transmitting area 702 are alternately arranged on the second surface 62 of the transparent substrate 6 to form a directional privacy screen structure. When the user observes from a normal viewing angle, light can pass through the light-transmitting area 702 to present a clear image; while when the viewing angle deviates from the normal direction (such as looking from the side), the line of sight will fall on the light-absorbing area 701, thereby blocking the displayed content and achieving a privacy screen effect.

[0068] Furthermore, since the surface contour of the light-transmitting area 702 can be further adjusted (e.g., by incorporating microstructure texture design), it can also provide effective light diffusion, making the emitted light softer and more uniform, further reducing glare and bright spots. Specifically, in this embodiment, light can enter from the outer surface 31 of the third scattering layer 3, undergo multiple scattering and homogenization processing through the multilayer scattering structure, and finally exit from the optical functional layer 7 disposed on the second surface 62 of the transparent substrate 6. This configuration enables the multilayer film to not only have anti-reflective function, but also to be used as a highly efficient light diffusion film. Through this optical path design, the uniformity of light and the range of light emission angles can be significantly improved, thereby effectively expanding the viewing angle performance. Overall, the light diffusion type anti-reflective film F of this utility model combines the dual optical characteristics of diffusion and privacy protection, and is particularly suitable for display applications with dual requirements for privacy and visual quality, such as financial terminal equipment, vehicle information display systems, or mobile device screens.

[0069] In other embodiments, an additional light-transmitting film layer (not shown in the figure) may be provided on the surface of the transparent substrate 6 to further enhance the overall optical properties of the film layer. This light-transmitting film layer may be a multilayer film structure; for example, it may be a multilayer film structure composed of PET (polyethylene terephthalate) and PEN (polyethylene naphthalate) or other polymeric materials with excellent optical transparency and mechanical stability.

[0070] Furthermore, the light-transmitting film layer can be adjusted in its optical behavior according to design requirements. For example, it can reflect light with a specific polarization direction (usually S-light, i.e., light with a polarization direction perpendicular to the incident plane) back to the backlight module, while allowing light with another polarization direction (usually P-light, i.e., light with a polarization direction parallel to the incident plane) to pass through. Simultaneously, the light-transmitting film layer can also integrate diffusion and brightness enhancement functions, improving brightness performance and light emission uniformity. In some applications, the light-transmitting film layer can directly replace the transparent substrate 6. This design change still maintains the optical functions disclosed in this invention, such as diffusion, anti-glare, privacy protection, or brightness enhancement, and can be modularly integrated according to application requirements, improving process flexibility and design freedom.

[0071] Beneficial effects of the embodiments

[0072] In existing technologies, light diffusion film structures with a single scattering layer are commonly used. However, when applied to high-resolution displays or backlight modules, these structures are prone to visual crosstalk phenomena such as bright spots or moiré patterns. In contrast, the light diffusion type anti-reflective film F provided by this invention employs a multi-layer scattering structure with at least three layers, and adjacent scattering layers have different refractive indices. Therefore, this invention utilizes the technical feature that "the second scattering layer 2 has a first interface B1 facing the first scattering layer 1 and a second interface B2 facing the third scattering layer 3, with the first interface B1 and the second interface B2 exhibiting an asymmetrical and non-uniformly distributed wavy profile," enabling light passing through the light diffusion type anti-reflective film to diffuse uniformly without reducing brightness.

[0073] For example, when the light-diffusing anti-reflective film F of this invention is applied to a backlight module, light from below can smoothly penetrate the transparent substrate and diffuse evenly in the multi-layer structure, providing a soft and stable surface light source and effectively eliminating flash or bright spots. On the other hand, when applied to the surface of a display as an anti-glare and anti-reflective film, when the user looks from above, the light will be guided by the surface rough texture and the difference in refractive index between layers, and most of the ambient light will be scattered or reflected and suppressed, thereby reducing reflection and improving display clarity.

[0074] The above-disclosed content is only a preferred and feasible embodiment of the present utility model, and is not intended to limit the scope of protection of the claims of the present utility model. Therefore, all equivalent technical changes made based on the content of the present utility model specification and drawings are included within the scope of protection of the claims of the present utility model.

Claims

1. A light-diffusing anti-reflective film, characterized in that, The light-diffusing anti-reflective film includes: A transparent substrate having a first surface and a second surface opposite to each other; and A multilayer scattering structure is disposed on the first surface, the multilayer scattering structure comprising: First scattering layer; A second scattering layer, stacked on top of the first scattering layer; and A third scattering layer is stacked on top of the second scattering layer; The second scattering layer has a first interface facing the first scattering layer and a second interface facing the third scattering layer, wherein the first interface and the second interface exhibit an asymmetrical and non-uniformly distributed wavy profile.

2. The light-diffusing antireflection film according to claim 1, wherein The first interface of the second scattering layer is in contact with the first scattering layer, the second interface of the second scattering layer is in contact with the third scattering layer, and the refractive index difference between the first scattering layer and the second scattering layer, and the refractive index difference between the second scattering layer and the third scattering layer are greater than or equal to 0.

1.

3. The light-diffusing antireflection film according to claim 1, wherein The upper surface of the first scattering layer is a prism surface, a pyramid surface, a wavy surface, or a circular arc surface.

4. The light-diffusing antireflection film according to claim 1, wherein The average amplitude of the first interface or the second interface of the second scattering layer is between 0.1 μm and 10 μm. The average amplitude is defined as follows: on the cross-sectional contour line of the first interface or the second interface, select several pairs of corresponding local highest points and adjacent local lowest points, calculate the height difference between each pair, and use the average value of the multiple height differences as the average amplitude.

5. The light-diffusing antireflection film according to claim 1, wherein The thickness of the second scattering layer can be divided into multiple wide thickness regions and multiple narrow thickness regions, and the multiple wide thickness regions and multiple narrow thickness regions are randomly distributed within the thickness range; wherein, the average thickness of the wide thickness regions is between 5 μm and 20 μm, and the average thickness of the narrow thickness regions is between 0.1 μm and 5 μm; wherein, the thickness of the second scattering layer is defined as the distance between the first interface and the second interface.

6. The light-diffusing antireflection film according to claim 5, wherein The multiple wide-thickness regions and the multiple narrow-thickness regions do not overlap with each other in an orderly manner.

7. The light-diffusing antireflection film according to claim 1, wherein When the third scattering layer is the outermost layer of the multilayer scattering structure, the ten-point average roughness of the outer surface of the third scattering layer is between 0.1 μm and 10 μm.

8. The light-diffusing antireflection film according to claim 1, wherein When the third scattering layer is the top layer of the multilayer scattering structure, the outer surface of the third scattering layer is a flat surface, a pyramid, a prism, a wavy surface, or a circular arc surface.

9. The light-diffusing anti-reflective film according to claim 1, characterized in that, The light-diffusing anti-reflective film further includes an optical functional layer disposed on the second surface of the transparent substrate.

10. The light-diffusing antireflection film according to claim 9, wherein The outer surface of the optical functional layer is a pyramid, a prism, a wavy surface, or a circular arc surface.

11. The light-diffusing antireflection film according to claim 9, wherein The outer surface of the optical functional layer is an asymmetrical and non-uniform wavy surface.

12. The light-diffusing antireflection film according to claim 9, wherein The optical functional layer comprises black optical resin.

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