Anti-glare layer and foldable display device

Abstract

The application provides an anti-glare layer and a foldable display device. The anti-glare layer is applied to the foldable display device, and the anti-glare layer comprises a substrate layer and a plurality of convex structures. The convex structures are arranged on the substrate layer, and the convex structures are in the shape of a circular truncated cone. The anti-glare layer can reduce the specular reflectivity of ambient light, and achieves the effect of anti-glare.

Description

Technical Field

[0001] This utility model relates to the field of display technology, and in particular to an anti-glare layer and a foldable display device. Background Technology

[0002] In recent years, with the widespread adoption of mobile electronic devices, consumers have increasingly demanded devices that simultaneously offer large display areas and high portability. Foldable screen technology has emerged to meet this need. Through its bendable physical form, foldable screens provide an immersive visual experience when unfolded and reduce space occupation when folded, thus satisfying both of these requirements.

[0003] However, the screen cover material often used to ensure folding performance has a smooth surface and a high specular reflectivity, which can easily produce severe glare under ambient light, affecting display clarity.

[0004] Therefore, the industry urgently needs a solution suitable for foldable screens that can balance excellent anti-glare performance with high display quality. Utility Model Content

[0005] This application provides an anti-glare layer and a foldable display device. The anti-glare layer can reduce the specular reflectivity of ambient light to achieve the effect of anti-glare.

[0006] This application provides an anti-glare layer for use in a foldable display device, the anti-glare layer comprising: basal layer; Multiple protruding structures are disposed on the base layer, and the protruding structures are frustum-shaped.

[0007] In some embodiments, the protrusion structure has a first surface and a second surface opposite to each other, the first surface being the side of the protrusion structure closer to the base layer, and the second surface being the side of the protrusion structure farther from the base layer; the area of ​​the first surface is greater than the area of ​​the second surface.

[0008] In some embodiments, the diameter of the first surface is 1.5 to 2 times the diameter of the second surface.

[0009] In some embodiments, the diameter of the second surface is from 1 nm to 100 nm.

[0010] In some embodiments, the distance between the rotational symmetry axes of two adjacent protrusions is 1.5 to 2 times the diameter of the first surface.

[0011] In some embodiments, the distance between the rotational symmetry axes of two adjacent protrusion structures is less than 400 nm.

[0012] In some embodiments, the height of the protrusion structure is 1 nm to 100 nm.

[0013] In some embodiments, a regular hexagon is formed by connecting one of the protruding structures as the center and the six adjacent protruding structures.

[0014] This application embodiment also provides a foldable display device, including: Display the main body; An anti-glare layer, wherein the anti-glare layer is the aforementioned anti-glare layer, and the anti-glare layer is disposed on the light-emitting side of the display body.

[0015] In some embodiments, the display body includes a flexible display panel and a flexible cover plate stacked together, and the anti-glare layer is adhered to the side of the flexible cover plate away from the flexible display panel.

[0016] The anti-glare layer and foldable display device provided in this application embodiment are applied to the foldable display device. The anti-glare layer includes a base layer and multiple protruding structures. The protruding structures are disposed on the base layer and can significantly reduce the specular reflectivity of the screen to achieve excellent anti-glare effect. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the first structure of the anti-glare layer provided in the embodiments of this application.

[0019] Figure 2 This is a schematic diagram of a second structure of the anti-glare layer provided in an embodiment of this application.

[0020] Figure 3 This is a schematic diagram of the protrusion structure provided in an embodiment of this application.

[0021] Figure 4 This is a schematic diagram of a third structure of the anti-glare layer provided in an embodiment of this application.

[0022] Figure 5 This is a schematic diagram of a first structure of a foldable display device provided in an embodiment of this application.

[0023] Figure 6 This is a schematic diagram of a second structure of the foldable display device provided in an embodiment of this application.

[0024] Figure 7 This is a schematic diagram of the homogenization layer provided in an embodiment of this application.

[0025] Figure 8 The following are display effect diagrams of the light-diffusing layer provided in the embodiments of this application: (1) is an effect diagram of the light spot emitted by the pixel unit of the foldable display device when the light-diffusing layer is not assembled; (2) is an effect diagram of the light spot emitted by the pixel unit of the foldable display device when the light-diffusing layer is assembled. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0027] This application provides an anti-glare layer and a foldable display device. The anti-glare layer can effectively convert the ambient light shining on it from strong specular reflection into soft diffuse reflection, thereby significantly reducing specular reflectivity and achieving an anti-glare effect while ensuring the original clarity of the displayed image. The following is a detailed description in conjunction with the accompanying drawings.

[0028] Please see Figure 1 as well as Figure 2 , Figure 1 This is a schematic diagram of the first structure of the anti-glare layer provided in the embodiments of this application. Figure 2 This is a schematic diagram of a second structure of the anti-glare layer provided in an embodiment of this application.

[0029] This application provides an anti-glare layer 10, which is applied to a foldable display device.

[0030] The anti-glare layer 10 includes a base layer 11 and multiple protrusion structures 12.

[0031] The base layer 11 serves as the carrier and support for the raised structure 12. This layer is composed of a material with excellent flexibility, optical transparency, and surface smoothness. In foldable applications, high-performance polymer materials can be used to ensure that the base layer 11 can deform in tandem with the raised structure 12 without breakage or permanent optical damage during repeated bending of the screen.

[0032] For example, the material of the substrate layer 11 can be polyimide (PI). Polyimide is a class of high-performance polymers, known for its excellent mechanical strength, thermal stability, chemical resistance, and flexibility. Through specific chemical modification and film-forming processes, polyimide films that combine high light transmittance and the required mechanical properties can be prepared. Of course, in other alternative embodiments, the substrate layer 11 can also be made of other transparent flexible polymer materials, such as polyethylene terephthalate (PET), polycarbonate (PC), or modified versions thereof.

[0033] Please see Figure 3 , Figure 3 This is a schematic diagram of the protrusion structure provided in an embodiment of this application. The protrusion structure 12 is disposed on the base layer 11 and is frustum-shaped. The frustum shape has a large bottom surface connected to the base layer 11 and a small top surface away from the base layer 11. Between the top surface and the bottom surface is a continuous, inclined side surface.

[0034] When parallel ambient light shines on the surface of the anti-glare layer 10, it is incident on the inclined surfaces of the various raised structures 12. According to the law of optical reflection, the light is reflected on each inclined surface. Crucially, due to the presence of the frustum-shaped structure, the screen surface is no longer a single normal direction, but rather filled with countless micro-inclined surfaces with different local normal directions. Therefore, the originally parallel incident light is reflected in many different directions. This process of dispersing concentrated, highly directional specular reflection light into diffuse reflection light propagating in all directions greatly reduces the light intensity at specific viewing angles (i.e., specular reflection angles). The user's eyes therefore no longer receive strong reflected light spots, thus eliminating glare, and the content displayed on the screen remains clearly visible from all viewing angles. This continuous inclined surface design, compared to pyramidal structures with discrete angles, provides a more continuous and softer light scattering distribution, resulting in a better visual effect.

[0035] The protruding structure 12 has a first surface 121 and a second surface 122, with the first surface 121 being the side of the protruding structure 12 closer to the base layer 11 and the second surface 122 being the side of the protruding structure 12 away from the base layer 11; the area of ​​the first surface 121 is larger than the area of ​​the second surface 122. This continuous sloping surface geometry, wider at the bottom and narrower at the top, is key to the efficient and uniform scattering of light rays at different incident angles.

[0036] The diameter D2 of the first surface 121 is 1.5 to 2 times the diameter D1 of the second surface 122, ensuring that the anti-glare layer 10 has both excellent anti-glare performance and reliable mechanical durability.

[0037] This ratio range is an optimized range verified through optical simulation and experiments. If the ratio is too small, for example, close to 1:1, the structure will resemble a cylinder with too small a side tilt angle. This means that the ability to deflect incident light is very weak, the scattering angle is narrow, and the anti-glare effect will be greatly reduced, making it impossible to effectively eliminate glare.

[0038] If this ratio is too large, it means that the bottom surface is very large and the top surface is very small, which will lead to two problems: First, under the same manufacturing process (such as nanoimprinting), the top of the structure is too sharp, which not only increases the difficulty of demolding and the defect rate, but also makes the top more prone to wear or collapse when subjected to external forces; Second, from a mechanical point of view, when a structure with an excessively large aspect ratio is subjected to bending stress, its root (where it connects to the base) will generate greater stress concentration, which will easily lead to structural fatigue damage in the long run and affect durability.

[0039] The diameter D1 of the second surface 122 ranges from 1 nm to 100 nm. The height H of the protrusion structure 12 ranges from 1 nm to 100 nm. Controlling the feature size of the structure at the nanometer level aims to ensure that all optical feature sizes are smaller than the wavelength of visible light (approximately 380 nm to 780 nm), i.e., at the subwavelength scale. Based on the principles of physical optics, this design can fundamentally suppress the diffraction effect of visible light, thereby effectively avoiding the generation of rainbow patterns and ensuring high-definition display quality.

[0040] According to the principles of physical optics, significant diffraction occurs when light encounters an obstacle or hole of similar wavelength. If the size of the protrusion 12 is in the micrometer range (e.g., 1 to 10 micrometers), the diffraction effect is very pronounced, causing white light to be dispersed. When the screen is viewed at a specific angle, colored, changing stripes, i.e., rainbow patterns, will appear. This is a serious optical defect that greatly interferes with the displayed content. In this application, by limiting the structure size to the subwavelength range (especially <400 nm), light interacts with the structure primarily through geometric optical behaviors of reflection and refraction, thereby fundamentally eliminating diffraction and rainbow patterns.

[0041] Furthermore, since the nanoscale structure is invisible to the display pixels, the protrusion structure 12 does not distort or interfere with the shape of individual pixels, allowing display light to pass smoothly through these microstructures, thereby preserving the original sharpness, detail, and color fidelity of the image.

[0042] The distance between the rotational symmetry axes of two adjacent protrusions 12 is 1.5 to 2 times the diameter D2 of the first surface 121.

[0043] It should be noted that the axis of rotational symmetry is a straight line perpendicular to the plane of the base layer 11 and passing through the geometric centers of the top surface (second surface 122) and bottom surface (first surface 121) of each frustum-shaped protrusion 12. Since the frustum structure itself is a rotationally symmetric body, this axis is the reference axis of its rotational symmetry. Limiting the distance between this axis essentially limits the arrangement density of the protrusions 12 on the base layer 11.

[0044] This ratio ensures that the protrusions 12 maintain sufficient density to achieve continuous and uniform light scattering, while avoiding adhesion or deformation during the fabrication process due to excessive density, thus guaranteeing the regularity and yield of the structure.

[0045] The distance D3 between the rotational symmetry axes of adjacent protrusions 12 is less than 400 nm. By limiting the distance to a subwavelength scale (especially less than 400 nm, which is the lower limit of visible light wavelength), the aim is to ensure that the microstructure period of the entire anti-glare layer 10 is at the subwavelength scale of visible light. When ambient light shines on the nanostructure with a period much smaller than its wavelength, it can effectively suppress the diffraction effect of light, thereby fundamentally avoiding the rainbow effect commonly found in traditional anti-glare films and ensuring the true color and purity of the displayed image.

[0046] Multiple protruding structures 12 can be periodically arranged on the base layer 11 in the form of an equilateral hexagonal array (or a close-packed array). Specifically, with one protruding structure 12 as the center, the lines connecting the six adjacent protruding structures 12 form a regular hexagon, that is, the structure is arranged in an equilateral hexagonal array (or a close-packed array). This arrangement can achieve the densest and most uniform structural coverage per unit area, thereby ensuring that light scattering has no directional differences, avoiding moiré patterns or visual patches caused by uneven arrangement, and achieving a uniform anti-glare effect.

[0047] Please see Figure 4 , Figure 4 This is a schematic diagram of a third structure of the anti-glare layer provided in an embodiment of this application.

[0048] In some alternative embodiments, the anti-glare layer 10 further includes an adhesive layer 13 disposed on the side of the substrate away from the raised structure. The adhesive layer 13 can be a self-venting double-sided adhesive. This self-venting double-sided adhesive (typically silicone-based) possesses excellent re-peeling and peeling properties and self-venting capability. During application, its structure allows air to escape automatically, preventing air bubbles and ensuring optical quality. More importantly, when the anti-glare layer 10 becomes scratched or worn due to long-term use, affecting visual performance, users or service personnel can easily peel it off and replace it with a new one under normal atmospheric conditions without the need for complex vacuum degassing or specialized equipment. This design greatly improves product maintainability and user experience, reducing the probability of scrapping due to surface damage and maintenance costs.

[0049] Please see Figure 5 , Figure 5 This is a schematic diagram of a first structure of a foldable display device provided in an embodiment of this application. This application provides a foldable display device 100, which can refer to an electronic device with foldable display functionality, such as a mobile phone or tablet computer. The foldable display device 100 includes a display body 20 and an anti-glare layer 10. The anti-glare layer 10 is the same as the anti-glare layer 10 in the above embodiment. The anti-glare layer 10 is disposed on the light-emitting side of the display body 20, meaning it is located on the path where the display light finally exits the screen, thus directly acting on the interface with ambient light, and is the first barrier to achieve the external anti-glare function.

[0050] Please see Figure 6 , Figure 6 This is a second structural schematic diagram of the foldable display device provided in this application embodiment. The display body 20 includes a flexible display panel 21 and a flexible cover plate 22 stacked together, and an anti-glare layer 10 is attached to the side of the flexible cover plate 22 away from the flexible display panel 21. The display body 20, as the light source for the image, can be a flexible active-matrix organic light-emitting diode (AMOLED) panel, or it can be another type of flexible liquid crystal display panel 21 (LCD).

[0051] The flexible cover plate 22 covers and adheres to the flexible display panel 21, primarily serving a physical protection function to prevent the panel from being scratched, impacted, or contaminated. To accommodate folding requirements, the cover plate possesses high light transmittance, high surface hardness (scratch resistance), and excellent bending performance. Currently, the industry mainly employs two technical approaches: one is ultra-thin glass (UTG), prepared through chemical thinning or float glass processes, which offers advantages such as good tactile feel, high hardness, and excellent optical performance; the other is colorless polyimide (CPI), which boasts excellent flexibility and light weight. Both can be considered preferred materials for the flexible cover plate 22 in this embodiment.

[0052] The anti-glare layer 10 is disposed on the side of the flexible cover plate 22 away from the flexible display panel 21 via the adhesive layer 13.

[0053] Please continue reading. Figure 6 as well as Figure 7 , Figure 7 This is a schematic diagram of the homogenization layer provided in an embodiment of this application.

[0054] The foldable display device 100 also includes a light-diffusing layer 23 disposed between the flexible display panel 21 and the flexible cover plate 22 to further improve display quality, especially to suppress potential flash point phenomena when working in conjunction with the anti-glare layer 10.

[0055] The homogenizing layer 23 includes an adhesive layer 231 and birefringent particles 232, with the birefringent particles 232 doped within the adhesive layer 231. The adhesive layer 231 can be optically clear adhesive (OCA). The birefringent particles 232 can be calcite. Alternatively, the birefringent particles 232 can be other inorganic or organic microparticles with birefringent properties, such as quartz or barium carbonate, as alternatives.

[0056] Please see Figure 8 , Figure 8 The following are display effect diagrams of the light-diffusing layer provided in the embodiments of this application: (1) is an effect diagram of the light spot emitted by the pixel unit of the foldable display device when the light-diffusing layer is not assembled; (2) is an effect diagram of the light spot emitted by the pixel unit of the foldable display device when the light-diffusing layer is assembled.

[0057] The crystal axes of the birefringent particles 232 are randomly distributed within the adhesive layer 231. When light emitted from the pixels of the display panel 21 enters the light-diffusing layer 23, it interacts with the numerous randomly oriented birefringent particles 232, causing random and slight deflections in the direction of light propagation. This process moderately diffuses and homogenizes the light spot of a single pixel before it propagates to the anti-glare layer 10, while maintaining the overall light energy essentially unchanged.

[0058] like Figure 8 As shown, after assembling the light-diffusing layer 23, the diameter of the light spot presented by the pixel unit increases significantly from the original size A to size B. This optical expansion effect helps to improve the effective distribution of light in the plane of the screen surface, thereby effectively increasing the screen aperture ratio, that is, the proportion of the effective light-emitting area in the total display area, and thus optimizing display uniformity and visual effect.

[0059] The synergistic effect of the light-diffusing layer 23 and the anti-glare layer 10 can effectively reduce or eliminate flashing. Light pre-processed by the light-diffusing layer 23 has a smoother intensity distribution, and when scattered by the external anti-glare layer 10, it significantly reduces flashing caused by microstructural interference. Therefore, the light-diffusing layer 23 and the anti-glare layer 10 constitute a synergistic optical system: the light-diffusing layer 23 optimizes the spatial distribution of light from within, providing a more ideal optical input for the anti-glare layer 10; the anti-glare layer 10 handles ambient light interference from the outside. Together, they ensure that the foldable display can present a clear, uniform, and glare-free high-quality image in various environments.

[0060] The embodiments of this application also provide an exemplary preparation method for the above-mentioned anti-glare layer 10, which mainly includes the following steps.

[0061] Substrate preparation: Provide a clean, transparent polyimide film as the substrate layer 11.

[0062] Adhesive coating: A layer of ultraviolet (UV) curable imprinting adhesive is uniformly coated on the surface of the substrate layer 11.

[0063] Nanoimprinting: A pre-made rigid template (such as a nickel template) with a surface having a negative shape to the target raised structure 12 array is pressed onto the imprinting adhesive layer 231 under certain pressure and temperature.

[0064] UV curing and demolding: UV light is used to irradiate the imprinting adhesive through the substrate or template to cure and set it. Subsequently, the template is separated from the substrate layer 11. At this time, the negative structure on the template is copied onto the imprinting adhesive, that is, the desired array of frustum-shaped protrusions 12 is formed on the substrate layer 11.

[0065] In some alternative implementations, depending on the requirements, an anti-reflection (AR) coating, an anti-fingerprint (AF) coating, or an antibacterial coating may be further deposited on the surface of the formed anti-glare layer 10 to give it more functionality.

[0066] In summary, the anti-glare layer 10 and the foldable display device 100 provided in this application embodiment are provided. The anti-glare layer 10 is applied to the foldable display device 100. The anti-glare layer 10 includes a base layer 11 and a plurality of protrusion structures 12. The protrusion structures 12 are disposed on the base layer 11. The protrusion structures 12 can significantly reduce the specular reflectivity of the screen and achieve excellent anti-glare effect.

[0067] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0068] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0069] The anti-glare layer and foldable display device provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application, and the descriptions of the embodiments above are only for the purpose of helping to understand this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An anti-glare layer, characterized in that, The anti-glare layer, applied to foldable display devices, comprises: basal layer; Multiple protruding structures are disposed on the base layer, and the protruding structures are frustum-shaped.

2. The anti-glare layer according to claim 1, characterized in that, The protrusion structure has a first surface and a second surface opposite to each other. The first surface is the side of the protrusion structure closer to the base layer, and the second surface is the side of the protrusion structure away from the base layer. The area of ​​the first surface is larger than the area of ​​the second surface.

3. The anti-glare layer according to claim 2, characterized in that, The diameter of the first surface is 1.5 to 2 times the diameter of the second surface.

4. The anti-glare layer according to claim 3, characterized in that, The diameter of the second surface is 1 nm to 100 nm.

5. The anti-glare layer according to any one of claims 1 to 4, characterized in that, The distance between the rotational symmetry axes of two adjacent protrusions is 1.5 to 2 times the diameter of the first surface.

6. The anti-glare layer according to claim 5, characterized in that, The distance between the rotational symmetry axes of two adjacent protrusions is less than 400 nm.

7. The anti-glare layer according to any one of claims 1 to 4, characterized in that, The height of the protrusion structure is 1 nm to 100 nm.

8. The anti-glare layer according to any one of claims 1 to 4, characterized in that, With one of the protruding structures as the center, the lines connecting the six adjacent protruding structures form a regular hexagon.

9. A foldable display device, characterized in that, include: Display the main body; An anti-glare layer, wherein the anti-glare layer is the anti-glare layer according to any one of claims 1 to 8, and the anti-glare layer is disposed on the light-emitting side of the display body.

10. The foldable display device according to claim 9, characterized in that, The display body includes a flexible display panel and a flexible cover plate stacked together, and the anti-glare layer is attached to the side of the flexible cover plate away from the flexible display panel.

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