Optical film with microlens structure

Abstract

The invention relates to an optical film with a micro-lens structure. The optical film comprises a base material layer and the micro-lens structure formed on the base material layer. The whole micro lens structure is a circular convex hull, the center of the micro lens structure is provided with a conical protrusion, the section of the micro lens structure is a combination of a triangle and a semicircle, and the section of the conical protrusion is an isosceles triangle so as to optimize light convergence, reduce light scattering and light energy loss, improve the optical gain effect, balance optical uniformity and brightness and adapt to light of different incident angles. The cross section of the circular convex hull is elliptical or semicircular, the front projection of the conical bulge is circular, and the junction of the conical bulge and the circular convex hull is a continuous surface, so that the brightness is improved, and the stress is dispersed. The top ends of the conical protrusions are rounded corners, abrasion resistance is optimized, stress concentration is reduced, light capture area is increased through tight arrangement, and uniform light distribution is achieved. In addition, the anti-adsorption back coating is arranged on the back face of the base material layer, and stacking adsorption between the membranes is prevented. The optical film with the micro-lens structure can be matched with a brightness enhancement film to be made into an attached micro-lens brightness enhancement film.

Description

Technical Field

[0001] The present application relates to the technical field of optical films, and in particular to an optical film with a microlens structure. Background Art

[0002] In today's display technology, various display products have increasingly stringent requirements for the performance of optical films. As a key component to improve the display effect, the traditional microlens type brightening film has made certain progress in the field of optical films. With its unique microlens structure, it has shown the advantages of high shielding and high diffusion. This feature enables the microlens film to effectively reduce light leakage, improve the contrast and purity of the picture in many application scenarios, and bring positive effects to the display effect. However, the optical benefits of the microlens film are still far behind the prism structure brightening film. The prism brightening film can efficiently converge and direct the light through its unique microstructure, thereby achieving a higher optical gain effect and improving the display brightness. Therefore, how to effectively improve the optical gain effect while retaining the core advantage of high shielding and high diffusion of the microlens film has become an important problem that needs to be solved in the current field of optical film technology. Current research and exploration focus on improvements in material selection, structural design, manufacturing process and other aspects, but a comprehensive and mature solution has not yet been found.

[0003] At the same time, with the continuous emergence of new display technologies such as OLED, Mini-LED, Micro-LED, etc., brightness enhancement films are facing unprecedented opportunities and challenges. New display technologies have put forward higher requirements on the optical performance, functional diversity and cost control of brightness enhancement films. The market demand for display products continues to upgrade, requiring not only higher brightness and better color performance, but also the optical effect of existing optical films must be continuously improved to meet the increasingly diverse market needs.

[0004] As an important product for enhancing the brightness of displays, microlens film has advantages over prism film in terms of shielding and scratch resistance. Good shielding can effectively prevent light scattering and interference, and improve the clarity and layering of the picture; excellent scratch resistance ensures the stability and reliability of the film during long-term use, and reduces the risk of display quality degradation due to surface scratches. Therefore, it is necessary to optimize the compound microlens structure to break through the limitations of traditional microlens film in optical gain effect, so that the product can achieve improved optical gain effect while retaining high shielding and high wear resistance. Summary of the invention

[0005] The purpose of the present application is to provide a new design of a compound microlens structure, which while retaining high shielding and high wear resistance, improves the optical gain effect and breaks through the limitations of traditional microlens films in terms of optical gain effect. The purpose of the present application is achieved through the following technical solutions. The optical film with a microlens structure of the present application includes a substrate layer and a microlens structure; The microlens structure is formed on the substrate layer; The three-dimensional shape of the microlens structure is a circular convex hull with a conical protrusion in the center; Wherein, the cross-sectional shape of the microlens structure is a combination of a triangle and a semi-circular arc.

[0006] In one embodiment, the cross-section of the conical protrusion is an isosceles triangle, and the apex angle of the isosceles triangle is in the range of 80° to 150°.

[0007] In one embodiment, the cross-section of the circular convex hull is an ellipse or a semi-circle, and the diameter of the circle in the front projection is in the range of 10μm to 100μm.

[0008] In one embodiment, the front projection of the conical protrusion is a circle and is within the front projection of the circular convex hull, and the diameter is in the range of 5μm to 50μm.

[0009] In one embodiment, the junction between the conical protrusion and the circular convex hull is a continuous surface.

[0010] In one embodiment, the top of the conical protrusion is rounded.

[0011] In one embodiment, the microlens structures are arranged in a honeycomb pattern, a matrix pattern or a random pattern.

[0012] In one embodiment, the microlens structures are closely arranged with each other.

[0013] In one embodiment, it further includes an anti-adsorption back coating, and the anti-adsorption back coating is formed on the back surface of the substrate layer.

[0014] In one embodiment, the microlens structure optical film is combined with a bottom brightness enhancement film to form a microlens prism composite brightness enhancement film by laminating.

[0015] Compared with the prior art, the present application has the following beneficial effects: An optical film with a compound microlens structure proposed in this application maintains high shielding and high wear resistance, effectively overcoming the limitations of traditional microlens films in optical performance. The microlens structure integrates a circular convex hull and a central conical protrusion. This compound structure not only enhances the light focusing ability but also optimizes the light path. Together, the circular convex hull and the central conical protrusion can enhance the light converging ability, enabling light to be concentrated and directed more efficiently, thereby improving the overall optical performance.

[0016] The cross-sectional shape of the microlens structure is designed as a combination of a triangle and a semi-circle, optimizing the light refraction and reflection processes and precisely controlling the light propagation path. The apex angle is in the range of 80° to 150° and can be adjusted according to specific application requirements to achieve the best optical performance. The diameter of the front projection circle of the circular convex hull is in the range of 10μm to 100μm, and the diameter of the front projection circle of the conical protrusion is in the range of 5μm to 50μm. This not only ensures the stability of the microlens structure but also optimizes the light focusing effect. By adjusting these two dimensional parameters, efficient light convergence and guidance can be achieved, thereby enhancing the optical gain effect.

[0017] The junction between the conical protrusion and the circular convex hull is a continuous surface, which helps to reduce the scattering and reflection losses of light at the junction, improve the light transmittance and utilization rate, and further enhance the optical gain effect. The top of the conical protrusion is designed as a rounded corner, reducing stress concentration, improving the wear resistance of the microlens structure, and also reducing light scattering through smooth transition, which helps to improve the optical performance. In summary, the design of the compound microlens structure in this application improves the optical gain effect through structural optimization while maintaining high shielding and high wear resistance. Description of the Drawings

[0018] Figure 1 is a schematic cross-sectional structure diagram of an optical film with a microlens structure in an embodiment of this application; Figure 2 is a schematic top-view structure diagram of an optical film with a microlens structure in an embodiment of this application; Figure 3 is a schematic top-view structure diagram of an optical film with a microlens structure in another embodiment of this application; Figure 4 is a schematic top-view structure diagram of an optical film with a microlens structure in another embodiment of this application.

[0019] Description of the Reference Numerals: 100, substrate layer; 200, microlens structure; 210, circular convex hull; 220, conical protrusion. Detailed Description of the Embodiment

[0020] To make the above objects, features, and advantages of the present application more apparent and understandable, the following provides a detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings. It can be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Additionally, it should be noted that for ease of description, only the parts related to the present application rather than all the structures are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0021] The terms "comprising" and "having" in this application and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0022] Referring to "embodiments" herein means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0023] As one of the key optical elements, the performance of the optical film directly affects the display effect and user experience of various optical devices. With the continuous improvement of consumers' requirements for display quality, brightness, contrast, and other indicators, traditional microlens films are gradually difficult to meet the increasingly stringent application requirements in terms of optical gain effect, shielding property, and abrasion resistance. The present application provides a new optical film with a microlens structure 200, aiming to achieve the improvement of optical performance. Next, the specific design, structure, and advantages of this optical film with the microlens structure 200 will be described in depth. Please refer to Figures 1 to 4 As shown, the optical film with the microlens structure 200 in a preferred embodiment of the present application includes a substrate layer 100 and a microlens structure 200. The microlens structure 200 is formed on the substrate layer 100. The three-dimensional profile of the microlens structure is a circular convex hull 210 with a conical protrusion 220 in the center. Among them, the cross-sectional shape of the microlens structure 200 is a combination of a triangle and a semi-circular arc.

[0024] The optical film with the microlens structure 200 of the present application is an optical element with unique optical properties and structural characteristics. Its core components include a substrate layer 100 and a microlens structure 200 formed on the substrate layer 100. The microlens structure 200 as a whole presents the form of a circular convex hull 210. At the exact center position of the circular convex hull 210, a conical protrusion 220 is provided, optimizing the optical regulation ability of the optical film through a compound structure. Further, from the perspective of the cross-sectional shape, the cross-section of the microlens structure 200 is not a conventional shape, but is composed of a combination of a triangle and a semi-circle arc. The compound design including the circular convex hull 210 and the central conical protrusion 220, combined with the cross-sectional shape being a combination of a triangle and a semi-circle arc, can more effectively focus and converge light. When light is incident on the surface of the optical film, the circular convex hull 210, as a basic optical element, conducts preliminary refraction and convergence of the light, while the central conical protrusion 220 further converges and guides the light, enabling the light to pass through the optical film more intensively, reducing light scattering and loss, thereby improving the optical gain effect, making the light passing through the optical film brighter and stronger in intensity, and enhancing the overall performance of the optical system.

[0025] The cross-sectional shape of the combination of a triangle and a semi-circle arc provides a path guidance for the propagation of light within the microlens structure 200. The triangular part has specific angles and shapes, which can refract the incident light regularly, enabling the light to propagate in a predetermined direction; while the semi-circle arc part plays a role in smooth transition and further converging the light, avoiding sudden changes and scattering of the light during the propagation process. This precise control of the light propagation path enables the light to propagate more orderly when passing through the optical film, improving the utilization rate of the light and reducing the energy loss caused by light scattering.

[0026] The three-dimensional structure of the circular convex hull 210 and the conical protrusion 220, as well as the special cross-sectional shape design, enable the microlens structure 200 to maintain relatively stable optical properties under the incidence of light at different angles and wavelengths. Due to the symmetry and regularity of the structural design, the influence on the propagation process of light within the microlens structure 200 is relatively small, and there will be no significant fluctuations in optical properties due to small changes in the incident angle or wavelength. This is crucial for the normal operation of the optical system under different environmental conditions, and can ensure that the optical device always maintains a stable display effect and optical performance.

[0027] In the optical film with the microlens structure 200, the cross-sectional shape of the conical protrusion corresponding to the central conical protrusion 220 of the microlens structure 200 is designed as an isosceles triangle. Through optical calculations and experimental verification, its angular range is controlled between 80° and 150° to achieve the best performance of the optical film in different application scenarios. When the apex angle of the isosceles triangle is within the range of 80° to 150°, the conical protrusion 220 can converge the incident light more effectively. If the apex angle is too small, the refraction angle change of the light on the conical surface is too drastic, which may cause the light to be too concentrated in an extremely small area, not only increasing the mutual interference between the lights, but also possibly causing adverse phenomena such as diffraction during the subsequent propagation of the light, reducing the utilization rate of the light; while if the apex angle is too large, the converging effect of the cone on the light will be weakened, and efficient light concentration cannot be achieved. Controlling the apex angle within this range can enable the light to achieve a relatively gentle and effective refraction on the conical surface, converge the light to a suitable area, improve the optical gain effect, and enhance the light focusing ability of the optical film. In addition, it also helps to balance the optical uniformity and brightness of the optical film. When the apex angle is between 80° and 150°, after the light is refracted by the conical protrusion 220, a relatively uniform light distribution can be formed on the surface of the optical film, avoiding the situation of local overbrightness or overdarkness, thus ensuring the overall brightness and color uniformity of the display screen. In practical applications, the angles of the light incident on the optical film are diverse. The isosceles triangle apex angle range of 80° to 150° enables the conical protrusion 220 to better adapt to lights with different incident angles. For lights with a large range of incident angles, the cross-section of the conical protrusion within this angle range can effectively refract and converge them, reducing the optical performance fluctuations caused by the change of the incident angle.

[0028] From the perspective of the manufacturing process, controlling the apex angle of the isosceles triangle within the range of 80° to 150° is beneficial to simplifying the manufacturing process of the microlens structure 200. In the existing micro-nano processing technology, precise processing and manufacturing can be relatively easily achieved, reducing the requirements for processing equipment and technology. At the same time, due to the reduction of processing difficulty, the rejection rate during the manufacturing process will also be correspondingly reduced, thereby reducing the production cost and improving the market competitiveness of the product. It is of great significance for the large-scale production of the optical film with the microlens structure 200 and can promote the wide application of this technology in more fields.

[0029] In the optical film with the microlens structure 200, the cross-sectional shape of the circular convex hull 210 in the microlens structure 200 is either an ellipse or a semi-circle. The diameter of the circle presented by the projection of the circular convex hull 210 in the direction perpendicular to the surface of the optical film (i.e., the front side) is controlled within the range of 10 μm to 100 μm. When the cross-section is a semi-circle, the refraction and reflection processes of light on the convex hull surface are relatively regular, enabling relatively uniform convergence and diffusion of light, which is suitable for scenarios with high requirements for light distribution uniformity, such as some display devices that require uniform illumination. When the cross-section is an ellipse, due to the characteristics of different major and minor axes of the ellipse, the propagation characteristics of light in different directions will vary, and this difference can be used for more precise deflection and focusing control of light. For example, in applications where light enhancement in a specific direction is required, the circular convex hull 210 with an elliptical cross-section can better meet the requirements. By adjusting the ratio of the major and minor axes of the ellipse, the propagation direction and convergence degree of light can be flexibly changed, thereby achieving the regulation of the propagation characteristics of light.

[0030] The size of the circular convex hull 210 with a front-projected circle diameter within the range of 10 μm to 100 μm can well adapt to various optical systems of different scales and types. The tiny circular convex hull 210 can regulate the propagation of light, reduce light scattering and loss, thereby improving the optical imaging quality. Within the diameter range of 10 μm to 100 μm, the circular convex hull 210 can effectively increase the light incident area, enabling more light to enter the microlens structure 200 and be regulated. The elliptical or semi-circular cross-sectional shape can guide light to undergo specific refraction and reflection within the microlens structure 200, reducing light reflection loss and scattering phenomena, and improving the light transmittance and utilization rate. Additionally, it has high feasibility and stability in the manufacturing process. This size range is within the achievable range of existing micro-nano processing technologies, and existing processing technologies such as molding can more precisely manufacture the circular convex hull 210 structure that meets the requirements. Moreover, the relatively stable size and shape design helps to reduce errors and defect rates during the manufacturing process, improve the product yield and consistency. In addition, this design also facilitates the optimization and improvement of the manufacturing process to meet different production scales and cost requirements, providing a strong guarantee for the large-scale production and application of optical films.

[0031] In the optical film with the microlens structure 200, the front projection shape of the conical protrusion 220 in the center of the microlens structure 200 in the direction perpendicular to the surface of the optical film is a standard circle, and this circular projection is strictly within the front projection range of the circular convex hull 210. At the same time, the diameter of the front projection circle of the conical protrusion 220 is controlled within the range of 5μm to 50μm. The selection of the diameter range is based on the optimization consideration of the light focusing effect. If the diameter is too small (less than 5μm), the conical protrusion 220 will be limited in its convergence effect on light, and may not be able to effectively concentrate enough light, resulting in an insignificant optical gain effect; if the diameter is too large (greater than 50μm), the difference in the refraction angle of light on the conical surface will increase, which is prone to produce aberrations and scattering phenomena, affecting the focusing quality of light. Controlling the diameter within the range of 5μm to 50μm can reduce aberrations and scattering while ensuring effective convergence of light, enhance the convergence effect of light, and improve the optical gain performance of the optical film.

[0032] Achieve fine optical control: The front projection circle diameter of the conical protrusions 220 of different sizes can achieve fine control of light at the microscopic level. In the range of 5μm to 50μm, by adjusting the diameter of the conical protrusions 220, the refraction angle and propagation path of light in the microlens structure 200 can be changed. For example, a smaller diameter can make the light converge more strongly in a smaller area, which is suitable for applications that require high-precision spot focusing, such as laser processing, optical storage and other fields; while a larger diameter can make the light convergence area relatively large and the light distribution more uniform, which is suitable for display and lighting scenes with high requirements for light uniformity. This fine optical control capability enables the optical film with the microlens structure 200 to adapt to the needs of a variety of complex optical systems and improve the performance and flexibility of the optical system.

[0033] Specifically, the junction of the conical protrusion 220 and the circular convex hull 210 is a continuous surface. Setting it as a continuous surface can first further improve the brightness. The continuous surface design at the junction of the conical protrusion and the circular convex hull 210 can also effectively disperse the stress concentration phenomenon generated when the structure is subjected to force. When the structure is subjected to an external load, the stress is no longer concentrated at a certain point or a small area, but is dispersed and conducted along the specific geometric shape formed by the angle. For example, when subjected to pressure perpendicular to the surface of the structure, the geometric structure of the continuous surface can decompose the pressure into component forces along the side of the conical protrusion and the outer surface of the circular convex hull 210, thereby reducing the local stress level, improving the overall load-bearing capacity and fatigue resistance of the structure, and extending the service life of the structure.

[0034] To optimize wear resistance, the conical protrusion 220 does not present a sharp tip shape, and the tip has been specially designed to form a rounded corner structure. In the traditional structure of the conical protrusion 220 with a sharp tip, when subjected to external loads, stress will concentrate in the tip area, making this part a weak link in the structure and prone to fatigue failure or fracture. After setting the rounded corner, the stress distribution can be significantly improved. The smooth surface of the rounded corner can evenly disperse the stress into the surrounding materials, avoiding excessive stress concentration at the tip, thereby improving the load-bearing capacity and fatigue resistance of the conical protrusion 220 and the structure where it is located. When the structure is subjected to impact loads, the rounded corner tip can play a role in buffering and dispersing the impact force. The rounded corner gradually transmits and disperses the impact force to the entire structure through its smooth surface, reducing the magnitude of the impact force received locally and improving the structure's ability to resist impact. During the product assembly process, the sharp tip may cause scratches or damage to the surrounding components or operators. The rounded corner tip is safer and will not have an adverse impact on the assembly process. In addition, the rounded corner structure can also reduce interference during assembly, making the assembly process smoother, improving the assembly efficiency and assembly quality.

[0035] Specifically, the microlens structure 200 is arranged in a honeycomb pattern, a matrix pattern, or a random pattern. The hexagonal structure of the honeycomb pattern has the largest filling rate, which can make full use of the space on the carrier surface, arrange more microlens units within a limited area, and enable a higher integration of optical performance on devices of the same size. For example, in a display panel, more microlenses can enhance the light convergence and diffusion effects, improving the display brightness and contrast. Due to the high symmetry and periodicity of the honeycomb pattern, light can be refracted and scattered relatively uniformly when passing through the microlens array, which helps to reduce optical distortion and aberration and improve the imaging quality. The tightly arranged hexagonal structure enables the microlens units to support each other, enhancing the mechanical stability of the entire microlens array. The regularity of the matrix pattern makes the design and manufacturing process of the microlens structure 200 relatively simple. In the optical design stage, the position and parameters of each microlens unit can be accurately calculated through a mathematical model, facilitating the simulation and optimization of optical performance. During the manufacturing process, microlens structures 200 arranged in a matrix pattern can be easily realized using micro-nano processing technologies such as lithography and etching, and high processing accuracy and consistency can be ensured. The matrix pattern can be conveniently expanded or reduced according to actual needs. By increasing or decreasing the number of rows and columns of microlens units, the size and optical performance of the microlens array can be adjusted to meet the requirements of different scales and application scenarios. The randomly arranged microlens structure 200 can break the optical performance limitations brought by traditional regular arrangements and achieve some special optical functions. Since there is no fixed geometric relationship between the randomly arranged microlens units, the propagation path of light when passing through the microlens array is more complex and diverse. This complexity enables the microlens structure 200 to have a certain anti-interference ability against external disturbances (such as light polarization, incident angle changes, etc.) and can maintain relatively stable optical performance under different environmental conditions. This scalability makes the microlens structure 200 arranged in a matrix pattern have broad application prospects in various optical devices and systems.

[0036] The micro-lens structure 200 is on a preset bearing plane or the surface of a specific optical element, and is not distributed in a loose and widely spaced manner, but is closely arranged with each other. Here, the close arrangement means that adjacent micro-lens structures 200 are as close as possible in space, and their edges are almost seamlessly connected. The center distance between adjacent micro-lenses is controlled within a very small and precise range. Generally, this distance is less than a specific ratio of the bottom diameter of the micro-lens itself (for example, less than 10% - 30% of the bottom diameter, and the specific ratio is determined comprehensively according to factors such as the design purpose of the micro-lens, optical performance requirements, and manufacturing process capabilities). From a macroscopic perspective, the micro-lens array presents a highly integrated and continuous appearance; from a microscopic level analysis, each micro-lens unit strictly follows the rule of close arrangement, forming a tight and orderly layout with the surrounding micro-lenses. The closely arranged micro-lens structure 200 can increase the capture area of incident light. When light irradiates the surface of the micro-lens array, due to the close adjacency of the micro-lenses, the scattering and loss of light at the gaps between the micro-lenses are reduced, and more light can be captured by the micro-lenses and converged to a predetermined focal position. The closely arranged micro-lens structure 200 also helps to achieve a more uniform light distribution. Each micro-lens refracts and regulates light independently. Through close arrangement, the optical effects between adjacent micro-lenses complement and coordinate with each other, which can eliminate the non-uniformity of light distribution and reduce the appearance of bright spots and dark areas.

[0037] In the overall structural design of the product, it also includes an anti-adhesion back coating, which is uniformly formed on the back surface of the substrate layer 100. During the preparation process, a low-density particle coating can be used to avoid generating high haze to reduce the loss of incident light. The anti-adhesion back coating can maintain a certain space with other stacked optical films by the support of the added particles, avoiding the stacked adhesion between multiple optical films.

[0038] Specifically, a lower brightness enhancement film can also be arranged on the back surface of the substrate layer 100 to make a conformable micro-lens brightness enhancement film, thereby further improving the brightness output of the display device. Specific embodiments Some specific implementation manners will be further introduced below to further elaborate on the technical solutions of the present application.

[0040] Embodiment 1: A micro-lens structure including a circular convex bulge and a conical protrusion is formed on the substrate layer, where the angle of the cross-section of the conical protrusion is 80°, the diameter of the front projection circle of the circular convex bulge is 100 μm, the diameter of the front projection circle of the conical protrusion is 50 μm, and the top of the conical protrusion is a rounded corner. There is an included angle at the connection surface between the circular convex bulge and the conical protrusion.

[0041] Embodiment 2: In Embodiment 2, the top of the conical protrusion is a sharp corner, and other technical features are the same as those in Embodiment 1.

[0042] Example 3. In Example 3, the junction between the conical protrusion and the circular convex hull is a continuous surface, and the top of the conical protrusion is a sharp corner. Other technical features are the same as those in Example 1.

[0043] Example 4. In Example 4, the junction between the conical protrusion and the circular convex hull is a continuous surface. Other technical features are the same as those in Example 1.

[0044] Comparative Example 1. In Comparative Example 1, the structure with a conical protrusion is not provided, and the technical features of other parts are the same as those in Example 1.

[0045] The shielding property, light homogenization property, wear resistance, and brightness ratio of each example are tested, and the relevant test results are shown in Table 1.

[0046] Table 1 Connection methods, apex forms of each example and relevant test results It can be found through the above tests that the brightness ratio of the technical solution adopting the micro-lens structure of the present application can be significantly improved, indicating that any form of micro-lens structure in the technical solution of the present application can improve the brightness ratio. Further, when the apex angle of the micro-lens structure is selected as a rounded corner, the light homogenization property and wear resistance are improved, and by adopting the connection method of a continuous surface, the brightness ratio can be further improved.

[0047] As can be seen from the foregoing, the present application provides an optical film with a micro-lens structure, including a substrate layer and a micro-lens structure formed thereon. The micro-lens structure is in the overall shape of a circular convex hull, with a conical protrusion provided in the center to form a compound structure. Its cross-section is a combination of a triangle and a semi-circle arc, and the cross-section of the circular convex hull is an ellipse or a semi-circle, which is beneficial for light focusing and diffusion, reduces scattering and reflection losses, improves the light transmittance and utilization rate, and has high feasibility and stability in the manufacturing process. The junction between the conical protrusion and the circular convex hull is a continuous surface, which can disperse stress, improve the structural load-bearing capacity and fatigue resistance, and extend the service life. The top of the conical protrusion is specially treated to form a rounded corner, which improves the stress distribution, enhances the load-bearing and impact resistance capabilities, reduces assembly interference, and ensures safety and efficiency.

[0048] Controlling the apex angle of the isosceles triangle of the cross-section of the conical protrusion within the range of 80° to 150° can simplify the manufacturing process, reduce the processing difficulty and the rejection rate, lower the cost, improve the product competitiveness, promote the wide application of the technology. The micro-lens structure can be arranged in a honeycomb shape, matrix or irregularly. The micro-lens structures are closely arranged on the bearing plane or the surface of a specific optical element, and the center distance between adjacent micro-lenses is precisely controlled, increasing the light capture area, reducing scattering and loss, and achieving uniform light distribution. The optical film with a micro-lens structure of the present application realizes efficient light regulation, improves the optical performance and stability, and at the same time reduces the production cost through unique structure design, reasonable arrangement method and optimized manufacturing process.

[0049] The above is only a specific embodiment of the present application, and any improvements made on the premise of the concept of the present application are regarded as the protection scope of the present application.

Claims

1. An optical film having a microlens structure, characterized in that: comprising a substrate layer and a microlens structure; The microlens structure is formed on the substrate layer; The three-dimensional appearance of the microlens structure is a circular convex hull with a conical protrusion in the center; Wherein, the cross-sectional shape of the microlens structure is a combination of a triangle and a semicircular arc.

2. The optical film with a microlens structure according to claim 1, characterized in that: The cross section of the conical protrusion is an isosceles triangle, and the vertex angle of the isosceles triangle is in the range of 80° to 150°.

3. The optical film with a microlens structure according to claim 1, characterized in that: The cross section of the circular convex hull is an ellipse or a semicircle, and the diameter of the circle projected from the front is in the range of 10 μm to 100 μm.

4. The optical film with a microlens structure according to claim 3, characterized in that: The front projection of the conical protrusion is a circle, and within the front projection of the circular convex hull, the diameter is in the range of 5 μm to 50 μm.

5. The optical film with a microlens structure according to claim 1, characterized in that: The junction between the conical protrusion and the circular convex hull is a continuous surface.

6. The optical film with a microlens structure according to claim 1, characterized in that: The top of the conical protrusion is rounded.

7. The optical film with a microlens structure according to claim 1, characterized in that: The microlens structures are arranged in a honeycomb shape, a matrix shape or a random shape.

8. The optical film with a microlens structure according to claim 7, characterized in that: The microlens structures are closely arranged with each other.

9. The optical film with a microlens structure according to claim 1, characterized in that: The invention also includes an anti-adsorption back coating layer, wherein the anti-adsorption back coating layer is formed on the back side of the substrate layer.

10. The optical film with a microlens structure according to claim 1, characterized in that: The optical film is combined with the lower brightness enhancement film to form a microlens prism composite brightness enhancement film.

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