Optical film and method, apparatus for manufacturing the same

Abstract

The application provides an optical film and a manufacturing method and device thereof. The optical film is configured on an exit light path of a display unit. The optical film comprises a triacetate cellulose film layer, and a first light-transmitting layer and a second light-transmitting layer respectively arranged on opposite surfaces of the triacetate cellulose film layer. The first light-transmitting layer and the second light-transmitting layer are both doped with inorganic particles, so that the hardness of the first light-transmitting layer and the hardness of the second light-transmitting layer are both higher than that of the triacetate cellulose film layer. The optical film provided by the application has good physical and chemical stability, can maintain good optical and mechanical properties in long-term use, and thus improves the touch sensitivity and display quality of the display device.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to an optical film and its manufacturing method and apparatus. Background Technology

[0002] Optical films are functional film materials that combine excellent optical and mechanical properties, and are also key upstream products with high technological barriers in the LCD display industry chain. Optical films are widely used in touch panels and flexible panels. However, the components inside the panel generate heat loads during operation, causing moisture trapped during the manufacturing process to gradually penetrate into the optical film, resulting in swelling of the film material and affecting the display quality and touch sensitivity of flexible display devices. Summary of the Invention

[0003] The main objective of this application is to provide an optical film and its manufacturing method and apparatus, which can improve the physical and chemical stability of the optical film, maintain good optical and mechanical properties, and improve the touch sensitivity and display quality of the display device after long-term use.

[0004] In a first aspect, this application provides an optical film disposed in the light emission path of a display unit, the optical film comprising: A cellulose triacetate film layer, comprising a first surface and a second surface, wherein the first surface of the cellulose triacetate film layer is configured to face the display unit in the emitted light path, and the second surface of the cellulose triacetate film layer is configured to face away from the display unit in the emitted light path; and... A first light-transmitting layer is provided on the first surface of the cellulose triacetate membrane, and a second light-transmitting layer is also provided on the second surface of the cellulose triacetate membrane. Both the first and second light-transmitting layers are doped with inorganic particles so that the hardness of the first and second light-transmitting layers is higher than that of the cellulose triacetate membrane.

[0005] Secondly, this application provides a method for manufacturing an optical film, the method comprising: providing a cellulose triacetate film layer; coating a first curing coating liquid onto a first side of the cellulose triacetate film layer; coating a second curing coating liquid onto a second side of the cellulose triacetate film layer; and curing the first curing coating liquid and the second curing coating liquid to obtain a first light-transmitting layer and a second light-transmitting layer, wherein the first light-transmitting layer is disposed on the first side of the cellulose triacetate film layer and the second light-transmitting layer is disposed on the second side of the cellulose triacetate film layer.

[0006] Thirdly, this application provides a display device that includes an optical film as described in any embodiment of this application, or the manufacturing process of the display device includes an optical film manufacturing method as described in any embodiment of this application, or the display device includes an optical film and the manufacturing process of the optical film employs an optical film manufacturing method as described in any embodiment of this application.

[0007] Fourthly, this application provides an electronic device that includes an optical film as described in any embodiment of this application, or that includes a display device as described in any embodiment of this application.

[0008] This application provides an optical film that improves both surface hardness and dimensional stability by sandwiching a first and second light-transmitting layer with higher hardness onto opposite sides of a cellulose triacetate film. Furthermore, by incorporating inorganic particles into the first and second light-transmitting layers, the density of the first and second light-transmitting layers is increased, thus hindering the penetration of moisture into the cellulose triacetate film. The incorporation of inorganic particles into the first light-transmitting layer also improves adhesion to metal circuitry, facilitating the wiring configuration of the metal mesh layer. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 A cross-sectional structural schematic diagram of an optical film provided in an embodiment of this application; Figure 2 A cross-sectional structural schematic diagram of an optical film provided in an embodiment of this application; Figure 3 A schematic diagram of the winding operation of an optical film provided in an embodiment of this application; Figure 4 A cross-sectional structural schematic diagram of an optical film provided in an embodiment of this application; Figure 5 This is a schematic diagram of the electric field distribution of a touch capacitive structure provided in an embodiment of this application; Figure 6 A schematic diagram of the structure of a first metal mesh layer and a second metal mesh layer provided in an embodiment of this application; Figure 7 A cross-sectional structural schematic diagram of an optical film provided in an embodiment of this application; Figure 8 This is a cross-sectional structural schematic diagram of a display device provided in an embodiment of this application; Figure 9 This is a schematic flowchart of a method for manufacturing an optical film according to an embodiment of this application; Figure 10 A schematic flowchart illustrating an optical film manufacturing method according to an embodiment of this application; Figure 11 This is a schematic flowchart of a method for manufacturing an optical film according to an embodiment of this application; Figure 12 This is a schematic block diagram of a display device provided in an embodiment of this application.

[0011] Figure label: X, first direction; Y, second direction; R, output light path; 100. Optical film roll; 110. Optical film; 120. Core of optical film roll; 130. Surface of optical film roll; 200. Display device; 201. Display unit; 202. Cover plate; 10. Cellulose triacetate film layer; 11. First side; 12. Second side; 13. Cellulose triacetate film roll; 131. Roll core; 132. Roll surface; 141. First end; 142. Second end; 21. First light-transmitting layer; 211. First surface; 212. Second surface; 22. Second light-transmitting layer; 23. Protective film; 231. Adhesive surface; 232. Weakly adhesive surface; 30. First metal mesh layer; 311. First electrode; 312. Second electrode; 32. First planarization layer; 321. Planar surface; 40. Second metal mesh layer; 411. Third electrode; 412. Fourth electrode; 42. Second planarization layer; 51. First electric rotating shaft; 52. Second electric rotating shaft; 53. Roller; 54. Coating head; 541. First coating head; 542. Second coating head. Detailed Implementation

[0012] 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 some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0013] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0014] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0015] It should be understood that, in order to clearly describe the technical solutions of the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with essentially the same function and effect. For example, the first callback function and the second callback function are only used to distinguish different callback functions and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" do not necessarily mean they must be different.

[0016] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0017] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0018] Optical films are functional film materials that possess both excellent optical and mechanical properties. They are also a key upstream product with high technological barriers in the electronic display industry chain and have been widely used in cutting-edge display technologies such as flexible displays, AR, and VR. However, since display devices often have more than one type of film layer in their stacked structure, and different film materials have different physicochemical properties, external moisture in the manufacturing process can sometimes be adsorbed and trapped by the relevant film materials. During actual use, this moisture is gradually released due to internal heat loads, causing abnormal humidity in the surface microenvironment of the optical film. This can lead to problems such as film swelling and delamination, resulting in decreased stability of the overall optical structure and affecting display quality.

[0019] In touch display panels, the optical film also needs to ensure the stability and reliability of its electrical properties. When the film swells, its dielectric properties change. If moisture penetration into the optical film cannot be prevented, phenomena such as ghost touches can occur, affecting touch sensitivity and accuracy.

[0020] like Figure 1As shown in the embodiment of this application, an optical film 110 is proposed. The optical film 110 can be disposed in the light output path of the display unit 201. The optical film 110 may include a cellulose triacetate film layer 10, which includes a first surface 11 and a second surface 12. The first surface 11 of the cellulose triacetate film layer 10 is configured to face the display unit 201 in the light output path, and the second surface 12 of the cellulose triacetate film layer 10 is configured to face away from the display unit 201 in the light output path.

[0021] It should be understood that, since the cellulose triacetate film 10 is an amorphous polymer, it can be formed using solution casting, exhibiting low molecular orientation and good uniformity. Therefore, the cellulose triacetate film 10 also possesses advantages such as high visible light transmittance. Thus, a cellulose triacetate film 10 with a visible light transmittance greater than 92% can be used to improve display quality. Furthermore, the cellulose triacetate film 10 possesses certain optical compensation properties, making it less prone to display defects such as rainbow patterns.

[0022] Specifically, a first light-transmitting layer 21 may be coated on the first surface 11 of the cellulose triacetate membrane 10, and a second light-transmitting layer 22 may be coated on the second surface 12 of the cellulose triacetate membrane 10. Both the first light-transmitting layer 21 and the second light-transmitting layer 22 are doped with inorganic particles, so that the hardness of the first light-transmitting layer 21 and the hardness of the second light-transmitting layer 22 are both higher than that of the cellulose triacetate membrane 10, thereby hindering the penetration of water vapor into the cellulose triacetate membrane 10.

[0023] By incorporating inorganic particles into the first light-transmitting layer 21 and the second light-transmitting layer 22 deposited on opposite sides of the cellulose triacetate membrane 10, not only can the hardness of the first and second light-transmitting layers 21 and 22 be improved, but their density can also be increased, thus slowing down the penetration of moisture into the cellulose triacetate membrane 10. Furthermore, the incorporation of inorganic particles into the first light-transmitting layer 21 can also improve the adhesion to metal circuit patterns, facilitating the setting of functional layers for devices such as touch electrodes.

[0024] By sandwiching the first light-transmitting layer 21 and the second light-transmitting layer 22, which have higher hardness, onto the opposite sides of the triacetate cellulose membrane layer 10, it is possible to avoid the direct application of loads such as scratches and compression to the soft triacetate cellulose membrane layer 10 body. Furthermore, the symmetrical sandwich design on both sides can also avoid shrinkage stress after the single-sided coating has cured, prevent warping, ensure flatness, and improve dimensional stability and light transmission uniformity.

[0025] For example, the first light-transmitting layer 21 and the second light-transmitting layer 22 may include resin materials such as acrylate resin, and the inorganic particles may include inorganic particles such as silica particles and silicon particles. Through the doping design, the inorganic particles are distributed within the three-dimensional cross-linked network formed by the curing of the first light-transmitting layer 21 and the three-dimensional cross-linked network formed by the curing of the second light-transmitting layer 22. This can fill the pores in the resin cross-linked network, improve the density of the first light-transmitting layer 21 and the second light-transmitting layer 22, reduce the microscopic pathways for water vapor diffusion and penetration, and thus slow down the penetration of water vapor into the cellulose triacetate film layer 10 in the internal microenvironment of the display device 200.

[0026] In some embodiments, the inorganic particles may include silica particles or silicon particles modified with a silane coupling agent, and the first light-transmitting layer 21 may include a resin material. For example, inorganic particles can be incorporated into the first light-transmitting layer 21. The surface of the modified inorganic particles can act as crosslinking sites to bond with the active functional groups in the resin material, reducing areas of insufficient crosslinking and thereby improving the density of the first light-transmitting layer 21 and the second light-transmitting layer 22. Through particle doping design, the density of the first light-transmitting layer 21 can be made more uniform, reducing the density differences between various local areas within the first light-transmitting layer 21, thereby improving the optical uniformity of the optical film 110 and improving the display effect.

[0027] In some embodiments, the second light-transmitting layer 22 may include a resin material. Inorganic particles may be incorporated into the second light-transmitting layer 22, and the surface of the modified inorganic particles can serve as crosslinking sites to bond with the active functional groups in the resin material, reducing areas of insufficient crosslinking.

[0028] In some embodiments, either the first light-transmitting layer 21 or the second light-transmitting layer 22 can be a hardened coating. For example, the first light-transmitting layer 21 can be a hardened coating. In the manufacturing process, a first hardened coating liquid containing inorganic particles can be applied to the triacetate membrane layer 10, and the first light-transmitting layer 21 can be formed by curing processes such as ultraviolet irradiation and baking, which allows the inorganic particles to be uniformly distributed in the first light-transmitting layer 21. Similarly, the second light-transmitting layer 22 can be a hardened coating. In the manufacturing process, a second hardened coating liquid containing inorganic particles can be applied to the triacetate membrane layer 10, and the second light-transmitting layer 22 can be formed by curing processes such as ultraviolet irradiation and baking, which allows the inorganic particles to be uniformly distributed in the second light-transmitting layer 22. It should be understood that since the inorganic particles themselves do not participate in the curing reaction, the shrinkage rate of the hardened coating can be reduced, the residual stress at the interface between the first light-transmitting layer 21, the triacetate membrane layer 10, and the second light-transmitting layer 22 can be reduced, and the bonding strength and reliability between layers can be improved.

[0029] In some embodiments, the inorganic particles may include at least one of surface-modified silicon particles, silica particles, and alumina particles. A portion of the inorganic particles is exposed on the surface of the first light-transmitting layer 21 doped with them. One end of each inorganic particle may be covalently cross-linked with an organic resin, while the other end may retain the active groups obtained from the surface modification. This allows the active groups to form covalent bonds with metal atoms and metal oxides, thereby enhancing the strength and adhesion of the interfacial bonding. Specifically, the inorganic particles may include inorganic particles modified with a silane coupling agent.

[0030] In some embodiments, the particle size of the inorganic particles doped in the first light-transmitting layer 21 can be larger than the particle size of the inorganic particles doped in the second light-transmitting layer 22. It should be understood that using inorganic particles with smaller particle sizes in the first light-transmitting layer 21 can improve the density of the first light-transmitting layer 21, thereby achieving a better effect in blocking water vapor penetration, and also improving the adhesion of subsequent metal layers on it.

[0031] In some embodiments, please refer to Figure 2 and Figure 3 The use of larger-diameter inorganic particles in the second light-transmitting layer 22 facilitates the storage, transportation, and use of the optical film 110. It should be understood that the manufacturing process of the optical film 110 requires the application of a protective film 23 to ensure the stability of its physicochemical properties during storage and transportation. For major downstream users such as panel manufacturers, the protective film 23 on the surface of the optical film 110 needs to be removed before further alignment and bonding processes can be performed. By using larger-diameter inorganic particles in the second light-transmitting layer 22, the adhesion of the protective film 23 to the optical film 110 is kept within a more reasonable range, facilitating the removal of the protective film by downstream users.

[0032] Specifically, the protective film 23 may include an adhesive side 231 and a weakly adhesive side 232. The adhesive side 231 of the protective film 23 can be attached to the second light-transmitting layer 22, while the weakly adhesive side 232 is positioned away from the second light-transmitting layer 22. The adhesiveness of the weakly adhesive side 232 can be weaker than that of the adhesive side 231, or it can be completely non-adhesive. This design allows the first light-transmitting layer 21, with stronger adhesion, to contact the weakly adhesive side 232 during the winding operation of the optical film 110, while the adhesive side 231 remains in contact with the second light-transmitting layer 22. This ensures that the single-layer protective film 23 protects both sides of the first and second light-transmitting layers 21 and 22. Before the optical film 110 is applied to the production line, the user can unwind the film and easily peel off the protective film 23 from the second light-transmitting layer 22 of the optical film 110. (See also...) Figure 3 and Figure 10The first light-transmitting layer 21 can be positioned facing the core 120, and the second light-transmitting layer 22 can be positioned away from the core 120, so that the outermost surface of the optical film 110 of the roll is covered with a protective film 23, reducing the area of ​​the first light-transmitting layer 21 and the second light-transmitting layer 22 that are in direct contact with the air, thereby improving the stability and reliability of the physical and chemical properties of the optical film 110.

[0033] In some embodiments, the particle size of the inorganic particles doped in the first light-transmitting layer 21 can be from 0.5 micrometers to 1.5 micrometers. Typically, but not limitingly, the particle size of the inorganic particles doped in the first light-transmitting layer 21 can be 0.5 micrometers, 0.7 micrometers, 1.0 micrometers, 1.2 micrometers, 1.5 micrometers, or any range of two such values. By making the particle size of the inorganic particles greater than 0.5 micrometers, excessive adhesion of the protective film 23 to the optical film 110 can be reduced. By making the particle size of the inorganic particles less than 1.5 micrometers, the visible light transmittance of the optical film 110 can be improved, thereby improving the optical performance of the optical film 110 and the display quality of the display device 200.

[0034] In some embodiments, the particle size of the inorganic particles doped in the second light-transmitting layer 22 can be from 0.5 micrometers to 1.5 micrometers. Typically, but not limitingly, the particle size of the inorganic particles doped in the second light-transmitting layer 22 can be 0.5 micrometers, 0.7 micrometers, 1.0 micrometers, 1.2 micrometers, 1.5 micrometers, or any combination of two such values. By making the particle size of the inorganic particles greater than 0.5 micrometers, excessive adhesion of the protective film 23 to the optical film 110 can be reduced. By making the particle size of the inorganic particles less than 1.5 micrometers, the visible light transmittance of the optical film 110 can be improved, thereby improving the optical performance of the optical film 110 and the display quality of the display device 200.

[0035] In some embodiments, the thickness of the cellulose triacetate membrane 10 can be from 20 micrometers to 50 micrometers. Typically, but not limitingly, the thickness of the cellulose triacetate membrane 10 can be 20 micrometers, 25 micrometers, 30 micrometers, 35 micrometers, 40 micrometers, 45 micrometers, 50 micrometers, or a range of any two of these values.

[0036] In the coating process of the first light-transmitting layer 21 and the coating process of the second light-transmitting layer 22, by making the thickness of the triacetate cellulose film layer 10 greater than or equal to 20 micrometers, the ability of the triacetate cellulose film layer 10 to withstand interfacial stress can be improved, the residual interfacial stress during the curing of the light-transmitting layer can be better withstood, wrinkles can be reduced, and the deformation resistance and visible light transmittance of the triacetate cellulose film layer 10 can be improved.

[0037] By making the thickness of the cellulose triacetate film layer 10 less than or equal to 50 micrometers, it is beneficial to make the display device 200 thinner and to design the flexible display device 200 bending structure, thus avoiding excessive thickness from occupying the mechanical design space of the bending part.

[0038] In some embodiments, the thickness of the first light-transmitting layer 21 or the second light-transmitting layer 22 can be from 1 micrometer to 3 micrometers. Typically, but not limitingly, the thickness of the first light-transmitting layer 21 can be 1 micrometer, 1.5 micrometers, 2 micrometers, 2.5 micrometers, 3 micrometers, or a range of any two of these values. Typically, but not limitingly, the thickness of the second light-transmitting layer 22 can be 1 micrometer, 1.5 micrometers, 2 micrometers, 2.5 micrometers, 3 micrometers, or a range of any two of these values.

[0039] By making the thickness of the first light-transmitting layer 21 or the second light-transmitting layer 22 greater than or equal to 1 micrometer, the first light-transmitting layer 21 and the second light-transmitting layer 22 can better enhance the hardness of the triacetate cellulose membrane layer 10 and the water vapor barrier function, thus providing a structurally reliable and dimensionally stable adhesion substrate for the first metal mesh layer 30.

[0040] By making the thickness of the first light-transmitting layer 21 or the second light-transmitting layer 22 less than or equal to 3 micrometers, the internal stress of volume shrinkage after coating curing can be reduced, the warping and curling of the film material can be reduced, and the overall flatness of the optical film 110 can be improved.

[0041] In some embodiments, please refer to Figure 4 The first light-transmitting layer 21 may include a first surface 211 and a second surface 212. The first surface 211 of the first light-transmitting layer 21 is configured to face the display unit 201 in the emitted light path, and the second surface 212 of the first light-transmitting layer 21 is configured to face away from the display unit 201 in the emitted light path. A first metal mesh layer 30 may be disposed on the first surface 211 of the first light-transmitting layer 21, and a first planarization layer 32 may be covered thereon. The first metal mesh layer 30 may be located between the first surface 211 and the first planarization layer 32 of the first light-transmitting layer 21.

[0042] It should be understood that by directly setting the first metal mesh layer 30 on the first light-transmitting layer 21, the excellent waterproof and adhesion properties of the first light-transmitting layer 21 can be fully utilized. Furthermore, relying on the stable and reliable physical, chemical and mechanical properties of the first planarization layer, the structural design of the base passivation layer can be eliminated, which can help to make the overall display device 200 thinner, simplify the stacked structure and reduce the number of process steps.

[0043] By depositing the first planarization layer 32 onto the first metal mesh layer 30, the first planarization layer 32 and the first light-transmitting layer 21 can form a structure sandwiched within the first metal mesh layer 30, thereby strengthening the bond strength between the first metal mesh layer 30 and the first light-transmitting layer 21. It should be understood that the first planarization layer 32 may also comprise a resin material, and the modified inorganic particles exposed on the surface of the first light-transmitting layer 21 can form a stable and reliable cross-linked network with the first light-transmitting layer 21, improving the adhesion of the first metal mesh layer 30 to the first light-transmitting layer 21.

[0044] In some embodiments, a first planarization layer 32 covers a first metal mesh layer 30 and forms a flat surface 321 facing the display unit 201, on which a second metal mesh layer 40 is disposed. By designing the first planarization layer 32 to cover the first metal mesh layer 30 and form a flat surface 321, the extended shape of the second metal mesh layer 40 can be made flatter, and the dielectric properties of each region between the second metal mesh layer 40 and the first metal mesh layer 30 can be made more consistent, which is beneficial to ensuring the stability and non-drift of the touch signal.

[0045] In some embodiments, please refer to Figure 4 and Figure 5 The first metal mesh layer 30 may be provided with a plurality of first electrodes 311 extending along a first direction at intervals, and a plurality of second electrodes 312 extending along a second direction at intervals. The first and second directions are arranged at an angle, and the second electrodes 312 of the first metal mesh layer 30 are staggered and connected to the first electrodes 311 of the first metal mesh layer 30. It should be understood that both the first electrodes 311 and the second electrodes 312 of the first metal mesh layer 30 may include strip-shaped metal electrodes. Through the staggered grid design of the strip-shaped metal electrodes, not only can they cooperate with the second metal mesh layer 40 to form a touch capacitor and realize the touch function, but they can also leave a grid-shaped light-transmitting space between the strip-shaped metal electrodes, thereby reducing occlusion and improving light transmittance.

[0046] In some embodiments, the second metal mesh layer may be provided with a plurality of third electrodes 411 extending along the first direction at intervals, and a plurality of fourth electrodes 412 extending along the second direction at intervals. The first direction and the second direction are arranged at an angle, and the fourth electrodes 412 of the second metal mesh layer 40 are alternately arranged and connected with the third electrodes 411 of the second metal mesh layer 40.

[0047] In some embodiments, the first electrode 311 of the first metal mesh layer 30 may be misaligned with the third electrode 411 of the second metal mesh layer 40. The second electrode 312 of the first metal mesh layer 30 may also be misaligned with the fourth electrode 412 of the second metal mesh layer 40. Alternatively, the first electrode 311 of the first metal mesh layer 30 may be misaligned with the third electrode 411 of the second metal mesh layer 40, and the second electrode 312 of the first metal mesh layer 30 may also be misaligned with the fourth electrode 412 of the second metal mesh layer 40.

[0048] By staggering the electrode grids of the first metal mesh layer 30 and the second metal mesh layer 40, the electric field distribution between the electrode grids of the first metal mesh layer 30 and the second metal mesh layer 40 can be optimized, avoiding excessive concentration of electric field lines between the electrode grids of the first metal mesh layer 30 and the second metal mesh layer 40, thereby generating a sensitive and reliable touch capacitance effect. This allows for more sensitive touch sensing even when the user is wearing gloves, improving touch sensitivity.

[0049] In some embodiments, please refer to Figure 6 The angle between the first and second directions can be from 30° to 75°. Typically, but not limitingly, the angle between the first and second directions can be 30°, 40°, 50°, 60°, 70°, 75°, or a range of any two values ​​therein. By making the angle between the first and second directions greater than or equal to 30°, the anisotropy of touch sensing can be reduced, improving the consistency of response sensitivity and tracking accuracy under different operating directions. By making the angle between the first and second directions less than or equal to 75°, the spatial symmetry of the grid structure can be reduced, making it difficult for multiple sets of periodic repeating patterns to form larger-scale repeating patterns after alignment, reducing moiré patterns and improving display quality.

[0050] In some embodiments, please refer to Figure 7 A second planarization layer 42 may be applied to the flat surface 321. The second planarization layer 42 is applied to the second metal mesh layer 40, which is disposed between the second planarization layer 42 and the flat surface 321. It should be understood that both the second planarization layer 42 and the first planarization layer 32 can be made of resin material, which can produce a good cross-linking effect. This strengthens the adhesion of the second metal mesh layer 40 to the first planarization layer 32 by combining the laminated structure of the first planarization layer 32, the second planarization layer 42, and the second metal mesh layer 40. Furthermore, the design of the first planarization layer 32 and the second planarization layer 42 helps to isolate the first metal mesh layer 30 and the second metal mesh layer 40 from a microenvironment that may contain moisture and impurities, thus improving the weather resistance of the first metal mesh layer 30 and the second metal mesh layer 40.

[0051] In some embodiments, please refer to Figure 8 The optical film 110 can be applied to a display device 200, which may include display units 201 such as a liquid crystal layer and a quantum dot array, and may also include a cover plate 202, which may be made of glass or resin. The optical film 110 can be disposed between the display unit 201 and the cover plate 202, and is located in the light path emitted by the display unit 201. The cover plate 202 can be directly applied to the optical film 110, or it can be disposed at a distance from the optical film 110. The display unit 201 can be connected to the optical film 110, or it can be disposed at a distance from the optical film 110. A touch function layer can also be disposed between the display unit 201 and the optical film 110.

[0052] In some embodiments, please refer to Figure 9 , Figure 9 This is a schematic flowchart illustrating the steps of a method for manufacturing an optical film 110 according to an embodiment of this application. The method for manufacturing the optical film 110 may include providing a cellulose triacetate film layer 10; coating a first hardening coating liquid onto a first surface 11 of the cellulose triacetate film layer 10; coating a second hardening coating liquid onto a second surface 12 of the cellulose triacetate film layer 10; and curing the first and second hardening coating liquids to obtain a first light-transmitting layer 21 and a second light-transmitting layer 22. The first light-transmitting layer 21 is disposed on the first surface 11 of the cellulose triacetate film layer 10, and the second light-transmitting layer 22 is disposed on the second surface 12 of the cellulose triacetate film layer 10. The first hardening coating liquid can be applied to the first surface 11 of the cellulose triacetate film layer 10 using a slot coating process, and the second hardening coating liquid can also be applied to the second surface 12 of the cellulose triacetate film layer 10 using a slot coating process.

[0053] The method for manufacturing the optical film 110 may include steps S101 to S104.

[0054] S101, Provides a cellulose triacetate membrane layer 10.

[0055] It should be understood that since cellulose triacetate includes amorphous polymer materials, it can be formed into a film by solution casting. Therefore, the molecular orientation degree in the cellulose triacetate film 10 is low and the phase distribution is more uniform, which can reduce the generation of rainbow patterns and has good optical and mechanical properties.

[0056] In some embodiments, a cellulose triacetate film layer 10 with a visible light transmittance of more than 92% can be used to improve the overall visible light transmittance of the optical film 110, thereby enhancing the brightness and color transparency of the display screen and reducing the power consumption of the backlight driver.

[0057] In some embodiments, please refer to Figure 10 , Figure 10 This is a schematic flowchart illustrating a method for manufacturing an optical film 110 according to an embodiment of this application. The cellulose triacetate film 10 can be placed on a roller 53 and moved as the roller 53 rotates. By controlling the rotational speed of the roller 53, the moving speed of the cellulose triacetate film 10 can be better controlled for subsequent coating processes.

[0058] S102. A first hardening coating liquid is applied to the first surface 11 of the cellulose triacetate membrane layer 10.

[0059] It should be understood that inorganic particles may be incorporated into the first hardening coating liquid. For example, surface-modified nano-silicon particles, silica particles, etc. By changing the density and hardness of the first light-transmitting layer 21, the permeation of water vapor in the microenvironment is slowed down in the direction of the first surface 11 of the triacetate cellulose membrane layer 10, thereby improving the structural strength of the optical membrane 110 and stabilizing the physicochemical, optical, and mechanical properties of the optical membrane 110.

[0060] In some embodiments, please refer to Figure 10 , Figure 10 This is a schematic flowchart illustrating a method for manufacturing an optical film 110 according to an embodiment of this application. A first hardening coating liquid can be applied to the first surface 11 of the cellulose triacetate film layer 10 using a slot coating process. The slot coating process is well-suited for roll-to-roll processes. For example, by controlling the height of the coating head 54 relative to the surface of the cellulose triacetate film layer 10 on the roller 53, and the flow rate of the first hardening coating liquid in the coating head 54, the first hardening coating liquid can be uniformly applied to the first surface 11 of the cellulose triacetate film layer 10, which helps to form a stable and uniform first light-transmitting layer 21.

[0061] For example, a coating head 54 with slits can be provided, which can be configured to correspond to a roller 53 configured to drive the triacetate film 10 to rotate; as the triacetate film 10 rotates relative to the coating head 54, the first hardening coating liquid can be uniformly applied to the surface of the triacetate film 10 in the form of coating beads or the like through the slits.

[0062] In some embodiments, inorganic particles can be doped into the first curing coating liquid before the first surface 11 of the cellulose triacetate film 10 is coated. For example, surface-modified nano-silicon particles, silica particles, etc., can be incorporated into the first curing coating liquid. By reducing the shrinkage rate of the first light-transmitting layer 21 in the subsequent curing process, the residual interfacial stress between the first light-transmitting layer 21 and the cellulose triacetate film 10 can be reduced, thereby improving the structural reliability of the optical film 110.

[0063] S103. Apply a second hardening coating liquid to the second side 12 of the cellulose triacetate membrane layer 10.

[0064] It should be understood that step S102 can be executed first, followed by step S103. Alternatively, step S103 can be executed first, followed by step S102. This can be adjusted according to process requirements, and no specific limitations are made here.

[0065] It should be understood that inorganic particles may be incorporated into the second hardening coating liquid. For example, surface-modified nano-silicon particles, silica particles, etc. By changing the density and hardness of the second light-transmitting layer 22, the permeation of water vapor in the microenvironment can be slowed down in the direction of the second surface 12 of the cellulose triacetate film layer 10, thereby improving the structural strength of the optical film 110 and stabilizing the physicochemical, optical, and mechanical properties of the optical film 110.

[0066] In some embodiments, after the first hardening coating liquid is applied to the first surface 11 of the cellulose triacetate membrane layer 10, the first hardening coating liquid can be cured to form a first light-transmitting layer 21 by a drying process and an ultraviolet irradiation process, and then the membrane is flipped over to apply the second hardening coating liquid. This improves the stability of the first light-transmitting layer 21 during the flipping process.

[0067] In some embodiments, please refer to Figure 10 , Figure 10 This is a schematic flow diagram of a method for manufacturing an optical film 110 according to an embodiment of this application. The second hardening coating liquid can be applied using a roll-to-roll process incorporating a slot coating process. In the roll-to-roll process, through the coordinated design of multiple rollers 53, in some parts of the process, the first side 11 of the cellulose triacetate film 10 faces upwards and is coated through a coating head 54; in other parts of the process, the second side 12 of the cellulose triacetate film 10 faces upwards and is coated through the coating head 54.

[0068] In some embodiments, the coating head 54 for coating the first side of the cellulose triacetate film 10 may be a different coating head 54 from the coating head 54 for coating the second side of the cellulose triacetate film 10. For example, a first coating head 541 may be provided for coating the first side 11 of the cellulose triacetate film 10 with a first hardening coating liquid. Alternatively, a second coating head 542 may be provided for coating the second side 12 of the cellulose triacetate film 10 with a second hardening coating liquid. Specifically, the first coating head 541 and the second coating head 542 may have different control parameters, or they may have different structural designs. Furthermore, the first coating head 541 and the second coating head 542 may have both different control parameters and different structural designs.

[0069] It should be understood that the inorganic particles doped in the first and second hardening coating liquids can have different particle sizes, thus their viscosities and leveling properties will also differ. Using different coating heads 54 for coating can, on the one hand, reduce flow channel contamination and improve the consistency of the optical and physical properties of the light-transmitting layers of the optical film 110; on the other hand, it allows for adaptation based on the physicochemical properties of the first and second hardening coating liquids from the perspectives of control parameters and flow channel structure, making the process control of the thickness and uniformity of the first and second light-transmitting layers 21 and 22 more accurate and reliable.

[0070] S104. The first and second hardening coating liquids are cured to obtain the first light-transmitting layer 21 and the second light-transmitting layer 22.

[0071] The first light-transmitting layer 21 is applied to the first surface 11 of the cellulose triacetate membrane 10, and the second light-transmitting layer 22 is applied to the second surface 12 of the cellulose triacetate membrane 10.

[0072] It should be understood that the first hardening coating liquid can be cured first after step S102 to obtain the first light-transmitting layer 21, and then the second hardening coating liquid can be cured after step S103 to obtain the second light-transmitting layer 22. Alternatively, the second hardening coating liquid can be cured first after step S103 to obtain the second light-transmitting layer 22, and then the first hardening coating liquid can be cured after step S102 to obtain the first light-transmitting layer 21. Furthermore, the first and second hardening coating liquids can be cured together after steps S102 and S103. By designing the process of curing one side first and then the other side, the stability of the first light-transmitting layer 21 or the second light-transmitting layer 22 during the flipping process can be improved.

[0073] In some embodiments, a photoinitiator may be incorporated into the first and second hardening coating liquids. This photoinitiator can absorb photon energy under ultraviolet irradiation and decompose to generate active free radicals, initiating a chain polymerization reaction within the first and second hardening coating liquids to form a three-dimensional cross-linked network structure, thereby achieving curing and obtaining the first transparent layer 21 and the second transparent layer 22.

[0074] Specifically, the first hardening coating liquid can be baked after step S102 to achieve pre-film formation, and then the second hardening coating liquid can be baked after step S103 to achieve pre-film formation. Alternatively, the second hardening coating liquid can be baked after step S103 to achieve pre-film formation, and then the first hardening coating liquid can be baked after step S102 to achieve pre-film formation. This pre-film formation process design can improve the uniformity and stability of the coating during the flipping process. After steps S102 and S103, the first and second hardening coating liquids are simultaneously subjected to ultraviolet light irradiation to achieve curing, resulting in a first light-transmitting layer 21 and a second light-transmitting layer 22.

[0075] In some embodiments, the optical film 110 may be manufactured using a roll-to-roll process. See also... Figure 11 , Figure 11 This is a schematic flowchart illustrating the steps of an optical film manufacturing method according to an embodiment of this application. This optical film 110 manufacturing method can be configured to manufacture an optical film roll 100. See also... Figure 3 and Figure 10 The optical film roll 100 may include a core 120 and a roll surface 130, and is configured to unwind and unfold into an optical film 110 as in any embodiment of this application.

[0076] The manufacturing method of the optical film 110 may include steps S201 to S202. It should be understood that step S201 is an improvement on step S101, and step S201 can be performed when step S101 is performed to achieve roll-to-roll process design. Step S202 is an improvement on steps S102, S103 and S104, and step S202 can be performed when steps S102, S103 and S104 are performed.

[0077] S201, Provides 13 rolls of cellulose triacetate film.

[0078] Please refer to Figure 12 The cellulose triacetate film roll 13 can be configured to form a cellulose triacetate film layer 10 after unwinding. The cellulose triacetate film layer 10 includes a first end 141 and a second end 142. The first end 141 of the cellulose triacetate film layer 10 is disposed on the roll surface 132 of the cellulose triacetate film roll 13, and the second end 142 of the cellulose triacetate film layer 10 is disposed on the core 131 of the cellulose triacetate film roll 13.

[0079] It should be understood that by providing the cellulose triacetate film roll 13, the movement speed of the cellulose triacetate film layer 10 can be controlled by controlling the roll rotation speed, so as to cooperate with the slot coating process and improve the uniformity of the first light-transmitting layer 21 and the second light-transmitting layer 22.

[0080] S202, rotate the second end 142 of the cellulose triacetate film 10 to unwind, and rotate the first end 141 of the cellulose triacetate film 10 to wind up, to obtain the optical film roll 100.

[0081] It should be understood that roll-to-roll processes can reduce the waiting time for loading and unloading materials in sheet production, thereby improving production efficiency. Furthermore, they can reduce potential scratches and contamination during loading, unloading, and handling of intermediate products, which helps improve production yield.

[0082] For example, please refer to Figure 10 The core 131 of the cellulose triacetate film roll 13 or the second end 142 of the cellulose triacetate film layer 10 can be set on the first electric rotating shaft 51, and the roll surface 132 of the cellulose triacetate film roll 13 or the first end 141 of the cellulose triacetate film layer 10 can be set on the second electric rotating shaft 52. With the synchronous rotation of the first electric rotating shaft 51 and the second electric rotating shaft 52, the coating head 54, dryer, ultraviolet irradiation equipment, etc. between the first electric rotating shaft 51 and the second electric rotating shaft 52 can work accordingly. Thus, while driving the first electric rotating shaft 51 to perform the unwinding operation of the cellulose triacetate film roll 13, the second electric rotating shaft 52 is also driven to perform the winding operation of the optical film roll 100, realizing the roll-to-roll process.

[0083] In some embodiments, after curing the first and second hardening coating liquids to obtain the first light-transmitting layer 21 and the second light-transmitting layer 22, a protective film 23 may be attached to the surface of the first light-transmitting layer 21. Specifically, the protective film 23 may be a PP protective film 23.

[0084] It should be understood that when the particle size of the inorganic particles doped in the first light-transmitting layer 21 is larger than that of the inorganic particles doped in the second light-transmitting layer 22, the adhesion of the protective film 23 on the surface of the first light-transmitting layer 21 is relatively weak, which is beneficial for end users to peel off the protective film 23 on the surface of the first light-transmitting layer 21 when using the optical film roll 100.

[0085] In some embodiments, a protective film 23 may be applied to both the surface of the first light-transmitting layer 21 and the surface of the second light-transmitting layer 22. Alternatively, the protective film 23 may be applied only to the surface of the first light-transmitting layer 21. It should be understood that when the protective film 23 is applied only to the surface of the first light-transmitting layer 21, the protective film 23 may include an adhesive surface 231 and a weakly adhesive surface 232. During the manufacture of the optical film roll 100, the surface of the first light-transmitting layer 21 may be connected to the adhesive surface 231, and the surface of the rolled second light-transmitting layer 22 may be connected to the weakly adhesive surface 232.

[0086] This application also proposes an optical film 110, the manufacturing process of which may include the optical film manufacturing method as described in any embodiment of this application. The optical film 110 may be an optical film roll 100 or a sheet-like optical film that has been cut.

[0087] This application also proposes a display device 200, which may include the optical film 110 as described in any embodiment of this application, or the manufacturing process of the display device 200 may include the optical film manufacturing method as described in any embodiment of this application. The display device 200 may be a flexible display device 200, a touch display device 200, or a flexible display device 200 with touch functionality. It should be understood that the optical film 110 has good physicochemical stability, which helps reduce film swelling problems, maintain good optical and mechanical properties, thereby improving the display quality of the display device 200 after long-term use. For a touch-enabled display device 200, the good structural reliability and stable physicochemical properties of the optical film 110 also help maintain the stability of touch capacitance parameters and dielectric parameters during long-term use, thereby improving touch sensitivity.

[0088] For example, the display device 200 may include an optical film 100, which is manufactured using an optical film manufacturing method as described in any embodiment of this application.

[0089] In some embodiments, please refer to Figure 8 Since the first light-transmitting layer 21 of the display device 200 is doped with inorganic particles, it has good density and hardness. The first metal mesh layer 30 can be directly set on it, thereby replacing the planarization layer design between the triacetate cellulose film layer 10 and the first metal mesh layer 30. It not only plays an insulating role between the triacetate cellulose film layer 10 and the first metal mesh layer 30, achieving interlayer insulation and slowing down the diffusion and contamination of metal ions and small molecule impurities, but also helps to reduce the complexity of the stacked structure and its related processes, and helps to make the display device 200 thinner.

[0090] This application also proposes an electronic device, which may include a display device 200 as in any embodiment of this application, or an optical film 110 as in any embodiment of this application.

[0091] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0092] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0093] The foregoing disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0094] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0095] The above embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of protection of this application. Any non-substantial changes and substitutions made by those skilled in the art based on this application shall fall within the scope of protection claimed by this application.

Claims

1. An optical film, characterized in that, The optical film is disposed in the outgoing light path of the display unit, and the optical film includes: A cellulose triacetate film layer, the cellulose triacetate film layer including a first surface and a second surface, the first surface of the cellulose triacetate film layer being configured to face the display unit in the emitted light path, and the second surface of the cellulose triacetate film layer being configured to face away from the display unit in the emitted light path; and... The first light-transmitting layer is provided on the first surface of the cellulose triacetate membrane, and the second light-transmitting layer is provided on the second surface of the cellulose triacetate membrane. Both the first light-transmitting layer and the second light-transmitting layer are doped with inorganic particles. The hardness of the first light-transmitting layer and the hardness of the second light-transmitting layer are both higher than that of the cellulose triacetate membrane.

2. The optical film as described in claim 1, characterized in that, The particle size of the inorganic particles doped in the first light-transmitting layer is larger than that of the inorganic particles doped in the second light-transmitting layer.

3. The optical film as described in claim 1, characterized in that, The inorganic particles doped in the first light-transmitting layer have a particle size of 0.5 micrometers to 1.5 micrometers; and / or, The inorganic particles doped in the second light-transmitting layer have a particle size of 0.5 micrometers to 1.5 micrometers.

4. The optical film according to any one of claims 1-3, characterized in that, The first light-transmitting layer includes a first surface and a second surface. The first surface of the first light-transmitting layer is configured to face the display unit in the outgoing light path, and the second surface of the first light-transmitting layer is configured to face away from the display unit in the outgoing light path. as well as, A first metal mesh layer is disposed on the first surface of the first light-transmitting layer, and a first planarization layer is covered thereon. The first metal mesh layer is located between the first surface of the first light-transmitting layer and the first planarization layer.

5. The optical film as described in claim 4, characterized in that, The first planarization layer covers the first metal mesh layer and forms a flat surface facing the display unit, and a second metal mesh layer is disposed on the flat surface.

6. The optical film as described in claim 5, characterized in that, The first metal mesh layer has a plurality of first electrodes arranged at intervals along a first direction and a plurality of second electrodes arranged at intervals along a second direction. The first direction and the second direction are arranged at an angle, and the first electrodes and the second electrodes are staggered and connected.

7. The optical film as described in claim 5, characterized in that, A second planarization layer is provided on the flat surface, the second planarization layer is provided on the second metal mesh layer, and the second metal mesh layer is disposed between the second planarization layer and the flat surface.

8. A method for manufacturing an optical film, characterized in that, include: Provides cellulose triacetate membrane layers; A first hardening coating liquid is applied to the first side of the cellulose triacetate membrane layer; A second hardening coating liquid is applied to the second side of the cellulose triacetate membrane layer; The first and second hardening coating liquids are cured to obtain a first light-transmitting layer and a second light-transmitting layer. The first light-transmitting layer is applied to the first side of the cellulose triacetate film, and the second light-transmitting layer is applied to the second side of the cellulose triacetate film.

9. The method for manufacturing an optical film as described in claim 8, characterized in that, The optical film manufacturing method is configured to manufacture an optical film roll, the optical film roll being configured to unwind and unfold into an optical film as described in any one of claims 1-7, wherein providing the triacetate cellulose film layer comprises: A cellulose triacetate film roll is provided, the cellulose triacetate film roll being configured to form a cellulose triacetate film layer after unwinding, the cellulose triacetate film layer including a first end and a second end, the first end of the cellulose triacetate film layer being disposed on the roll surface of the cellulose triacetate film roll, and the second end of the cellulose triacetate film layer being disposed on the core of the cellulose triacetate film roll; and, The optical film manufacturing method further includes the following steps: applying a first curing coating liquid to the first surface of the cellulose triacetate film layer, applying a second curing coating liquid to the second surface of the cellulose triacetate film layer, and curing the first and second curing coating liquids. The second end of the cellulose triacetate film is rotated to unwind, and the first end of the cellulose triacetate film is rotated to wind up, thus obtaining the optical film roll.

10. The method for manufacturing an optical film as described in claim 8 or 9, characterized in that, After curing the first and second hardening coating liquids to obtain the first and second light-transmitting layers, the process further includes: A protective film is attached to the surface of the first light-transmitting layer.

11. A display device, characterized in that, The display device includes a cover plate and an optical film as described in any one of claims 1-7, wherein the cover plate covers the side of the optical film opposite to the display unit; or, The display device includes an optical film, and the optical film is manufactured using the optical film manufacturing method as described in any one of claims 8-10.

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