Optical film, polaroid and display device

Abstract

The utility model relates to an optical film, a polaroid and a display device. The optical film comprises a substrate, a color matching layer and an antireflection layer, the toning layer is located on the substrate, and the material of the toning layer comprises a main body material and a functional structure; the functional structure contains at least one of a conjugated group, an electron-donating group, an electron-withdrawing group, metal ions and metal nanoparticles; the antireflection layer is located on the side, away from the substrate, of the toning layer. The antireflection layer is divided into at least one refractive index adjusting area in the direction, close to the antireflection layer, of the toning layer, the refractive index adjusting area comprises a first refractive index adjusting area and a second refractive index adjusting area, and the second refractive index adjusting area is located on the side, away from the toning layer, of the first refractive index adjusting area. The refractive index of the antireflection layer located in the second refractive index adjusting area is smaller than that of the antireflection layer located in the first refractive index adjusting area. When the optical film is applied to the display device, the integrated black effect of the display device in a screen-off state can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to an optical film, a polarizing film and a display device. BACKGROUND

[0002] Currently, the display area and the frame area of most vehicle-mounted display screens are different in color, so that the display screen has obvious color difference boundary between the display area and the frame area in the off-screen state, and cannot achieve the visual effect of one-piece black.

[0003] One-piece black refers to the color difference between the display area and the frame area of the display screen in the off-screen state being so small that the human eye cannot distinguish, so that the full screen is displayed as black. At present, in order to achieve the visual effect of one-piece black, the ink color of the frame area of the glass cover plate can be adjusted to make the color of the frame area consistent with that of the display area, but the degree of blackening is not enough to achieve the real one-piece black effect. In addition, one-piece black can also be achieved by coating the display area or by silk printing semi-transparent ink in the display area. However, the coating cost is high, the yield is low, and the transmittance of the product is reduced, resulting in the need for higher power to maintain the same display brightness. In addition, when the silk printing effect is not well controlled, there are screen scratches after lighting, which affects the display effect.

[0004] In order to improve this problem, it is necessary to develop a polarizing film that can improve the color hiding ability of the polarizing film and improve the one-piece black effect of the vehicle-mounted display screen. Content of the utility model

[0005] The present application provides an optical film, a polarizing film and a display device. When the optical film is applied to the display device, the color difference value between the display area and the frame area of the display panel can be effectively reduced, and the reflectivity of the surface of the display panel can be effectively reduced, so that the one-piece black effect of the display device in the off-screen state can be effectively improved.

[0006] In order to achieve the above purpose, according to the first aspect of the present application, an optical film is provided, comprising:

[0007] a substrate;

[0008] a color adjusting layer located on one side of the substrate; the material of the color adjusting layer comprises a main body material and a functional structure, the functional structure is bonded with the main body material or doped in the main body material, and the functional structure contains at least one of a conjugated group, an electron-donating group, an electron-withdrawing group, a metal ion and a metal nanoparticle; and

[0009] an anti-reflection layer located on the side of the color adjusting layer away from the substrate;

[0010] The anti-reflective layer is divided into at least one refractive index adjustment region along a direction of the color adjusting layer close to the anti-reflective layer, the refractive index adjustment region includes a first refractive index adjustment region and a second refractive index adjustment region, the second refractive index adjustment region is located on a side of the first refractive index adjustment region away from the color adjusting layer, and a refractive index of the anti-reflective layer in the second refractive index adjustment region is less than a refractive index of the anti-reflective layer in the first refractive index adjustment region.

[0011] In some embodiments, the anti-reflective layer is a single-layer structure; the anti-reflective layer includes a first base material located in the first refractive index adjustment region and the second refractive index adjustment region, a first doping material located in the first refractive index adjustment region and doped in the first base material, and a second doping material located in the second refractive index adjustment region and doped in the first base material; a refractive index of the first doping material is greater than a refractive index of the second doping material.

[0012] In some embodiments, the anti-reflective layer includes a first refractive index adjustment layer arranged in the first refractive index adjustment region and a second refractive index adjustment layer arranged in the second refractive index adjustment region;

[0013] A refractive index of the second refractive index adjustment layer is less than a refractive index of the first refractive index adjustment layer.

[0014] In some embodiments, a material of the first refractive index adjustment layer includes a second base material and a first doping material doped in the second base material, and a material of the second refractive index adjustment layer includes a third base material and a second doping material doped in the third base material;

[0015] A refractive index of the first doping material is greater than a refractive index of the second doping material.

[0016] In some embodiments, the anti-reflective layer is divided into a third refractive index adjustment region and one of the refractive index adjustment regions along a direction of the color adjusting layer close to the anti-reflective layer, the third refractive index adjustment region is arranged on a side of the first refractive index adjustment region away from the second refractive index adjustment region;

[0017] The anti-reflective layer includes a third refractive index adjustment layer arranged in the third refractive index adjustment region, a fourth refractive index adjustment layer arranged in the first refractive index adjustment region, and a fifth refractive index adjustment layer arranged in the second refractive index adjustment region;

[0018] A refractive index of the fourth refractive index adjustment layer is greater than refractive indices of the third refractive index adjustment layer and the fifth refractive index adjustment layer, and a refractive index of the third refractive index adjustment layer is greater than a refractive index of the fifth refractive index adjustment layer.

[0019] In some embodiments, the third refractive index adjusting layer and the fifth refractive index adjusting layer have a thickness of a quarter of a preset wavelength, and the fourth refractive index adjusting layer has a thickness of half of the preset wavelength; the preset wavelength ranges from 380 nm to 780 nm.

[0020] In some embodiments, the antireflection layer in the second refractive index adjusting region has a thickness ranging from 0.5 microns to 15 microns.

[0021] In some embodiments, the main body material of the color adjusting layer is selected from at least one of cellulose triacetate, polyethylene terephthalate, polymethyl methacrylate, polyurethane, polyvinyl chloride, chlorinated polyvinyl chloride, polypropylene, chlorinated polypropylene, polyethylene, and liquid crystal.

[0022] The color adjusting layer has a thickness ranging from 0.5 microns to 30 microns.

[0023] According to a second aspect of the present application, a polarizing sheet is provided, which includes a polarizing layer and the optical film sheet described above, the polarizing layer being located on a side of the substrate away from the color adjusting layer; the reflectivity of the antireflection layer on a side away from the color adjusting layer is less than 0.9%.

[0024] According to a third aspect of the present application, a display device is also provided, which includes a display module and the polarizing sheet described above, the polarizing sheet being located at least on a light-emitting side of the display module.

[0025] The display module includes a display area and a frame area located on at least one side of the display area; when the display device is configured in a dark state, the difference between the color difference value of the display device located in the display area and the color difference value of the display device located in the frame area is less than 1.2.

[0026] In the optical film sheet, the polarizing sheet, and the display device of the embodiments of the present application, by providing the color adjusting layer with a functional structure, the color phase a and b values of the color adjusting layer can be adjusted while ensuring high transmittance of the color adjusting layer, so that the reflection spectrum of the color adjusting layer is widened; at the same time, by providing the antireflection layer with an antireflection function, the reflectivity of the surface of the optical film sheet can be effectively reduced, thereby reducing the L value. Therefore, through the cooperation of the color adjusting layer and the antireflection layer, the color phase a and b values can be adjusted and the L The optical film can effectively reduce the color difference value of the display panel in the display area and the frame area in the off-screen state when the optical film is applied to the display device, effectively reduce the reflectivity of the display device surface, and effectively improve the all-black effect of the display device in the off-screen state.

[0027] Other features and advantages of the present application will be described in detail in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art.

[0029] In order to more completely understand the present application and its beneficial effects, the following will be described in conjunction with the drawings, wherein the same reference numerals in the following description represent the same parts.

[0030] Figure 1 is a cross-sectional structure schematic diagram of an optical film provided by an embodiment of the present application;

[0031] Figure 2 is a cross-sectional structure schematic diagram of another optical film provided by an embodiment of the present application;

[0032] Figure 3 is a cross-sectional structure schematic diagram of another optical film provided by an embodiment of the present application;

[0033] Figure 4 is a cross-sectional structure schematic diagram of a polarizing film provided by an embodiment of the present application;

[0034] Figure 5 is a top view structure schematic diagram of a display device provided by an embodiment of the present application;

[0035] Figure 6 is Figure 5 a cross-sectional structure schematic diagram at A-A' in FIG. 8.

[0036] Reference signs:

[0037] 1. Optical film; 2. Substrate; 3. Toning layer; 4. Antireflective layer; 4a. First refractive index adjustment area; 4b. Second refractive index adjustment area; 4c. Third refractive index adjustment area; 5. First substrate; 6. First doped material; 7. Second doped material; 8. First refractive index adjustment layer; 9. Second refractive index adjustment layer; 10. Second substrate; 11. Third substrate; 12. Third refractive index adjustment layer; 13. Fourth refractive index adjustment layer; 14. Fifth refractive index adjustment layer; 15. Polarizer; 16. Polarizing layer; 17. Pressure-sensitive adhesive layer; 18. Release film; 19. Display module; 20. Display device; 21. Display area; 22. Bezel area; 23. Light-shielding layer; 24. Protective cover plate. Detailed Implementation

[0038] 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 protection scope of this application.

[0039] To achieve a visual effect where the display area and bezel area appear as a single black color when the display device is off, the following solutions can be adopted.

[0040] The first approach involves adjusting the color of the ink layer on the glass cover. For example, after the glass cover undergoes computer numerical control (CNC) processing, strengthening, and a black border is screen-printed / vapor-deposited, an infrared (IR) ink semi-transparent printing process is then applied to the viewing area or button area of ​​the glass cover using screen printing. By adjusting the ink color and transmittance, a seamless black effect is achieved. However, this approach results in a 35% to 55% loss of transmittance for the display device.

[0041] The second approach involves coating the glass cover. For example, using magnetron sputtering and optical principles, an inorganic film can be directly deposited onto the glass cover, adjusting the reflectivity, transmittance, and color difference of the film in the viewing area to ensure that the display window and bezel colors are consistent. However, this approach results in a nearly 20% loss of transmittance for the display device.

[0042] The third option is to use a semi-transparent material for the cover plate, either plastic or glass. Taking plastic cover plates as an example, color powder is added to the resin material, and the amount of color powder added is adjusted to achieve a seamless black effect. Glass cover plates, on the other hand, can have color added during production or have their color adjusted through a dyeing process. However, this option results in a 50% to 70% loss of transmittance for the display device.

[0043] To solve the above technical problems, the embodiments of the present application provide an optical film, a polarizer and a display device. The optical film provided by the embodiments of the present application can improve the hue covering ability. When the optical film is applied to the polarizer, the hue covering ability of the polarizer can be improved, thereby improving the one-body black effect of the display device in the screen-off state. Compared with the above-mentioned three kinds of glass cover plates, the optical film with the hue covering ability is applied to the polarizer. On the one hand, the high transmittance can be maintained, thereby ensuring the high energy efficiency and high transmittance of the display device. On the other hand, the optical film has a wide reflection spectrum, and the hue covering ability at different viewing angles is superior, which can more effectively improve the visual effect of the one-body black of the display device in the screen-off state.

[0044] As shown in Figures 1 to 3 The embodiments of the present application provide an optical film 1. The optical film 1 includes a substrate 2, a color adjusting layer 3 and an anti-reflection layer 4. The color adjusting layer 3 is located on one side of the substrate 2, and the material of the color adjusting layer 3 includes a main body material and a functional structure. The functional structure is bonded to the main body material or doped in the main body material, and the functional structure contains at least one of a conjugated group, an electron-donating group, an electron-withdrawing group, a metal ion and a metal nanoparticle. The anti-reflection layer 4 is located on the side of the color adjusting layer 3 away from the substrate 2. The anti-reflection layer 4 is divided into at least one refractive index adjusting region along the direction of the color adjusting layer 3 close to the anti-reflection layer 4 (i.e. the direction of the anti-reflection layer 4 away from the color adjusting layer 3). The refractive index adjusting region includes a first refractive index adjusting region 4a and a second refractive index adjusting region 4b. The second refractive index adjusting region 4b is located on the side of the first refractive index adjusting region 4a away from the color adjusting layer 3. The refractive index of the anti-reflection layer 4 in the second refractive index adjusting region 4b is smaller than the refractive index of the anti-reflection layer 4 in the first refractive index adjusting region 4a.

[0045] It should be noted that in the CIE Lab color space, the calculation formula of the color difference value is as shown in formula (1):

[0046] (1)

[0047] Wherein, △E represents the color difference value, L represents the brightness of the color, a represents the axis from green to red, b represents the axis from blue to yellow; △L , △a , △b respectively represent the difference values of two colors on L, a and b axes.

[0048] The difference of two colors in three dimensions is combined into a value, so as to obtain a single number for describing the degree of color difference. That is, according to the size of the color difference value △E of two colors, it can be judged whether two colors are similar.

[0049] In the optical film 1 provided by the embodiment of the present application, the outer layer is the antireflection layer 4, and the inner layer is the color adjusting layer 3. The color adjusting layer 3 is arranged in the inner layer of the optical film 1, and the material of the color adjusting layer 3 comprises a main body material and a functional structure, and the functional structure is bonded to the main body material or doped in the main body material. The functional structure comprises at least one of a conjugated group, an electron-donating group, an electron-withdrawing group, a metal ion and a metal nanoparticle. By introducing at least one of the conjugated group, the electron-donating group, the electron-withdrawing group, the metal ion and the metal nanoparticle in the color adjusting layer 3, the hue, the transmittance and the reflection spectrum of the optical film 1 can be effectively adjusted.

[0050] Specifically, by introducing different functional groups or substituents on the main body material of the color adjusting layer 3, the chemical structure and the electron cloud distribution of the main body material can be changed, thereby affecting the optical properties of the main body material, and being conducive to improving the transmittance of the color adjusting layer 3 and adjusting the hue and the reflection spectrum of the color adjusting layer 3.

[0051] For example, by introducing a conjugated group on the main body material of the color adjusting layer 3, the resonance absorption of the main body material can be enhanced, so that the transmission and reflection spectrum moves to the long wave direction. By introducing an electron-donating group or an electron-withdrawing group on the main body material of the color adjusting layer 3, the ionization energy of the main body material can be adjusted, so that the position and intensity of the transmission and reflection spectrum can be adjusted. By introducing different metal ions on the main body material of the color adjusting layer 3, or adding different metal nanoparticles in the main body material of the color adjusting layer 3, the transmittance and the reflection spectrum of the color adjusting layer 3 can be adjusted by using the plasmonic resonance effect.

[0052] Therefore, by introducing the functional structure in the main body material of the color adjusting layer 3, the hue a value of the optical film 1 in the CIE Lab color space can be effectively adjusted, so that the reflection spectrum becomes wide, and the high transmittance of the optical film 1 can be ensured. When the optical film 1 is applied to the display area in the display device, by adjusting the material components of the color adjusting layer 3, the difference (△a ) of the hue a value and the difference (△b ) of the hue b value between the display area and the frame area of the display device in the off-screen state can be effectively reduced while ensuring the high transmittance. ), so that the chromatic aberration value ΔE of the display area and the frame area of the display device in the off-screen state can be reduced without affecting the transmittance, thereby facilitating the improvement of the integrated black effect of the display device in the off-screen state.

[0053] At the same time, by adjusting the material components of the color adjusting layer 3, the hue a and b values are adjusted, so that the reflection spectrum of the color adjusting layer 3 is widened. Since the wider the reflection spectrum is, the closer the color is to black, by adjusting the material components of the color adjusting layer 3, the integrated black visual effect of the display device in the off-screen state can be improved.

[0054] In a specific embodiment, the main material of the color adjusting layer 3 is selected from at least one of cellulose triacetate, polyethylene terephthalate, polymethyl methacrylate, polyurethane, polyvinyl chloride, chlorinated polyvinyl chloride, polypropylene, chlorinated polypropylene, polyethylene, and liquid crystal.

[0055] In some embodiments, a photoinitiator can also be added to the main material of the color adjusting layer 3, and ultraviolet light is irradiated, so that the formed color adjusting layer 3 has a gradient distribution in material components and thickness, and the hue, transmittance, and reflection spectrum of the color adjusting layer 3 can also be adjusted.

[0056] For example, when the main material of the color adjusting layer 3 is polypropylene, the main material can be modified to have at least one hydroxyl group; at the same time, a photoinitiator is added to the polypropylene main material, and ultraviolet light is irradiated when the color adjusting layer 3 is formed, so that the formed color adjusting layer 3 includes a first sub-color adjusting layer and a second sub-color adjusting layer; wherein the polypropylene main material of the first sub-color adjusting layer has one hydroxyl group, and the thickness is 5 microns; the polypropylene main material of the second sub-color adjusting layer has two hydroxyl groups, and the thickness is 7 microns. It should be noted that the refractive indexes of the first sub-color adjusting layer and the second sub-color adjusting layer are different. By adjusting the material components and thickness gradient distribution of the color adjusting layer 3, the hue, transmittance, and reflection spectrum of the color adjusting layer 3 can be adjusted, and the principle is that the material components and thickness gradient will affect the interference (multi-beam interference effect) and scattering behavior of light in the color adjusting layer 3, that is, it will affect the selective reflection or transmission of specific wavelengths, thereby affecting the intensity and bandwidth of the transmittance and reflection spectrum.

[0057] In some embodiments, the thickness of the color adjusting layer 3 ranges from 0.5 microns to 30 microns. By adjusting the thickness of the color adjusting layer 3, the hue, transmittance, and reflection spectrum of the color adjusting layer 3 can also be adjusted. Specifically, the thickness of the color adjusting layer 3 will affect the interference (multi-beam interference effect) and scattering behavior of light in the color adjusting layer 3, that is, it will affect the selective reflection or transmission of specific wavelengths, thereby affecting the intensity and bandwidth of the transmittance and reflection spectrum.

[0058] From the above, the present application can adjust the hue a and b value of the color shade by adjusting the material and thickness of the color adjusting layer 3, so that the reflection spectrum of the color adjusting layer 3 is widened, which is beneficial to improve the visual effect of the integral black of the display device in the off-screen state. Moreover, due to the relatively wide reflection spectrum, the color shade hiding ability of the optical film 1 at different viewing angles is relatively superior.

[0059] In some embodiments, when the number of refractive index adjusting regions divided by the antireflection layer 4 is greater than 1, the refractive index of the antireflection layer 4 changes in a gradient along the direction of the color adjusting layer 3 close to the antireflection layer 4. Taking the antireflection layer 4 divided into two refractive index adjusting regions as an example, along the direction of the color adjusting layer 3 close to the antireflection layer 4, the change rule of the refractive index of the antireflection layer 4 is high, low, high, and low. Obviously, the refractive index of the antireflection layer 4 in the second refractive index adjusting region 4b located at the outermost side of the antireflection layer 4 away from the color adjusting layer 3 is lower than that of the antireflection layer 4 in the adjacent first refractive index adjusting region 4a.

[0060] Since the antireflection layer 4 with gradient refractive index is arranged on the outer layer, the reflectivity of the surface of the optical film 1 can be effectively reduced, so that the L value of the optical film 1 in the CIE Lab color space can be reduced. When the optical film 1 is applied to the display area of the display device, by reducing the L value through the outer antireflection layer 4, the difference (△L ) between the L values of the display area and the frame area of the display device can be effectively reduced.

[0061] According to the color difference calculation formula (1), when the △L value is reduced, the color difference value △E between the display area and the frame area is reduced, which is beneficial to reduce the color difference between the display area and the frame area of the display device. When the display device is configured as a dark state (i.e. off-screen state), it is beneficial to improve the visual effect of the integral black.

[0062] In some embodiments, in any one refractive index adjusting region, the thickness of the antireflection layer 4 located in the second refractive index adjusting region 4b ranges from 0.5 microns to 15 microns. That is, in any one refractive index adjusting region, the thickness of the antireflection layer 4 located in the low refractive index region ranges from 0.5 microns to 15 microns.

[0063] It can be understood that when the number of low refractive index regions in the antireflection layer 4 is greater than 2, in order to control the production cost, on the basis of combining the interference principle, the thickness of each low refractive index layer can be appropriately reduced while ensuring the antireflection effect.

[0064] Similar to the color-correcting layer 3, the thickness of the antireflection layer 4 also affects the interference and scattering behavior of light within it, i.e., it affects the selective reflection or transmission of specific wavelengths. Therefore, by adjusting the thickness of the antireflection layer 4, the transmittance and reflectance of the optical film 1 can be adjusted, which is beneficial for reducing L... value.

[0065] In some embodiments, the refractive index can be adjusted by adding high-refractive-index material and low-refractive-index material to the first refractive index adjustment region 4a and the second refractive index adjustment region 4b of the antireflection layer 4, respectively.

[0066] In some embodiments, such as Figure 1 As shown, the antireflective layer 4 is a single-layer structure. A refractive index adjustment region is defined along the direction of the toning layer 3 near the antireflective layer 4 (i.e., from the antireflective layer 4 away from the toning layer 3). The refractive index adjustment region includes a first refractive index adjustment region 4a and a second refractive index adjustment region 4b. The second refractive index adjustment region 4b is located on the side of the first refractive index adjustment region 4a away from the toning layer 3. The antireflective layer 4 includes a first substrate 5 located in the first refractive index adjustment region 4a and the second refractive index adjustment region 4b, a first dopant material 6 located in the first refractive index adjustment region 4a and doped in the first substrate 5, and a second dopant material 7 located in the second refractive index adjustment region 4b and doped in the first substrate 5. The refractive index of the first dopant material 6 is greater than the refractive index of the second dopant material 7.

[0067] In this embodiment, the material of the substrate 2 of the optical film 1 is selected from any one or more combinations of tri-acetate cellulose (TAC), polyethylene terephthalate (PET), and polymethyl methacrylate (PMMA).

[0068] In some embodiments, the material of the first substrate 5 is an organic resin, including but not limited to TAC, PET, or PMMA.

[0069] In one specific embodiment, the first dopant material 6 is selected from at least one of titanium dioxide, antimony tin oxide, indium tin oxide, indium oxide, zinc oxide, tin oxide, antimony oxide, zirconium oxide, tungsten oxide, zinc antimonate, and vanadium oxide.

[0070] In one specific embodiment, the second doping material 7 is selected from at least one of hollow silica nanoparticles, fluorine-doped hollow silica nanoparticles, alumina nanoparticles, compounds containing silicon and fluorine, and fluorine-containing copolymers (e.g., polytetrafluoroethylene PTFE).

[0071] It can be understood that the first doping material 6 is a high refractive index material, which can increase the refractive index of the anti-reflective layer 4 in the first refractive index adjusting region 4a, and the second doping material 7 is a low refractive index material, which can decrease the refractive index of the anti-reflective layer 4 in the second refractive index adjusting region 4b.

[0072] In this embodiment, the refractive index of the anti-reflective layer 4 changes from high to low in the direction away from the color layer 3, and the anti-reflective layer 4 is doped with a particulate material, which can reduce the reflectivity of light on the surface of the anti-reflective layer 4 and increase the transmissivity of light in the anti-reflective layer 4 through the interference and scattering of light.

[0073] In other embodiments, as shown in FIG. 1C, the anti-reflective layer 4 is a double-layer stacked structure, in which case the anti-reflective layer 4 can be divided into the above-mentioned refractive index adjusting regions. The anti-reflective layer 4 includes a first refractive index adjusting layer 8 and a second refractive index adjusting layer 9 stacked on the color layer 3, the first refractive index adjusting layer 8 is located in the first refractive index adjusting region 4a, and the second refractive index adjusting layer 9 is located in the second refractive index adjusting region 4b. The refractive index of the second refractive index adjusting layer 9 is less than that of the first refractive index adjusting layer 8. Figure 2 It can be understood that the region where the first refractive index adjusting layer 8 is located is the first refractive index adjusting region 4a, and the region where the second refractive index adjusting layer 9 is located is the second refractive index adjusting region 4b; and the first refractive index adjusting layer 8 is a high refractive index layer, and the second refractive index adjusting layer 9 is a low refractive index layer. Different from the structure of the optical film 1 shown in FIG. 1B.

[0074] Figure 1 In this embodiment, the material of the substrate 2 of the optical film 1 is selected from TAC or PET, but is not limited thereto.

[0075] Specifically, the material of the first refractive index adjusting layer 8 includes a second substrate 10 and a first doping material 6 doped in the second substrate 10, and the material of the second refractive index adjusting layer 9 includes a third substrate 11 and a second doping material 7 doped in the third substrate 11. The refractive index of the first doping material 6 is greater than that of the second doping material 7.

[0076] Specifically, the materials of the second substrate 10 and the third substrate 11 can be the same or different. The materials of the second substrate 10 and the third substrate 11 are also organic resins, including but not limited to TAC, PET or PMMA.

[0077] Specifically, the first doping material 6 and the second doping material 7 can refer to the description in the foregoing embodiments, which will not be described here again.

[0078] Specifically, the first doping material 6 and the second doping material 7 can refer to the description in the foregoing embodiments, which will not be described here again.

[0079] ​In some embodiments, the second refractive index adjusting layer 9 can be obtained by blending the second dopant material 7 with the third substrate 11.

[0080] In a specific embodiment, the second dopant material 7 comprises fluorine and silicon elements, for example, hollow silica nanoparticles are modified to obtain fluorine-containing hollow silica nanoparticles as the second dopant material 7.

[0081] Specifically, the fluorine and silicon elements can form Si-F bonds, which is beneficial to reduce the electron cloud density of the material and thus reduce the refractive index of the film layer. In addition, the hydrophilicity of the silica containing Si-F bonds is better than that of pure silica. In addition, the hollow silica particles containing Si-F bonds can reduce the problem of weak particle compressive strength caused by too low porosity, thereby avoiding the scratch of the film layer under external force.

[0082] For example, when the doping amount (mass fraction) of fluorine element in the hollow silica nanoparticles is about 16%, the refractive index of the second refractive index adjusting layer 9 is less than or equal to 1.2, and at this time the reflectivity of the anti-reflective layer 4 is less than or equal to 0.70; when the doping amount of fluorine element is about 31%, the refractive index of the second refractive index adjusting layer 9 is less than or equal to 1.1, and at this time the reflectivity of the anti-reflective layer 4 is less than or equal to 0.62; when the doping amount of fluorine element is about 44%, the refractive index of the second refractive index adjusting layer 9 is less than or equal to 1.0, and at this time the reflectivity of the anti-reflective layer 4 is less than or equal to 0.53; when the doping amount of fluorine element is about 57%, the refractive index of the second refractive index adjusting layer 9 is less than or equal to 0.9, and at this time the reflectivity of the anti-reflective layer 4 is less than or equal to 0.46.

[0083] In a specific embodiment, the second dopant material 7 comprises a high fluorine copolymer, for example, tetrafluoroethylene PTFE. For example, tetrafluoroethylene can be blended with PMMA, TAC or PET substrate to form the second refractive index adjusting layer 9.

[0084] For example, by introducing high fluorine copolymer polytetrafluoroethylene (PTFE) into the PMMA matrix, the overall refractive index of the material can be effectively reduced. Since the high fluorine polymer has a very low refractive index (refractive index about 1.35), the high fluorine polymer and PMMA (refractive index about 1.49) form a blend or block copolymer, which can reduce the refractive index of the material to between 1.43 and 1.45. At the same time, the high fluorine polymer and PMMA have good compatibility and will not affect the transparency and processing performance of PMMA. Therefore, this scheme is simple in operation, controllable in cost and suitable for large-scale application.

[0085] In some embodiments, the thickness of the second refractive index adjusting layer 9 ranges from 6 microns to 8 microns. Since the greater the thickness of the second refractive index adjusting layer 9, the higher the cost, combined with the principle of light interference, the thickness of the second refractive index adjusting layer 9 is preferably 6 microns to 8 microns.Figure 2 Controlling the thickness of the second refractive index adjusting layer (low refractive index layer) 9 in the optical film 1 shown to be between 6 microns and 8 microns can effectively reduce the reflectivity of the optical film 1 without increasing costs.

[0086] In this embodiment, the refractive index of the antireflection layer 4 changes from high to low in the direction away from the color adjusting layer 3, and the antireflection layer 4 is doped with a particulate material. Through the interference and scattering of light, the reflectivity of light at the surface of the antireflection layer 4 can be reduced, and the transmissivity of light within the antireflection layer 4 can be increased.

[0087] In other embodiments, as shown in Figure 3 The antireflection layer 4 is divided into a third refractive index adjusting region 4c and a refractive index adjusting region in the direction of the color adjusting layer 3 close to the antireflection layer 4. The refractive index adjusting region includes a first refractive index adjusting region 4a and a second refractive index adjusting region 4b, the second refractive index adjusting region 4b is located on the side of the first refractive index adjusting region 4a away from the color adjusting layer 3, and the third refractive index adjusting region 4c is located on the side of the first refractive index adjusting region 4a away from the second refractive index adjusting region 4b.

[0088] The antireflection layer 4 includes a third refractive index adjusting layer 12 disposed in the third refractive index adjusting region 4c, a fourth refractive index adjusting layer 13 disposed in the first refractive index adjusting region 4a, and a fifth refractive index adjusting layer 14 disposed in the second refractive index adjusting region 4b. The refractive index of the fourth refractive index adjusting layer 13 is greater than the refractive index of the third refractive index adjusting layer 12 and the fifth refractive index adjusting layer 14, and the refractive index of the third refractive index adjusting layer 12 is greater than the refractive index of the fifth refractive index adjusting layer 14.

[0089] In some embodiments, the thickness of the third refractive index adjusting layer 12 and the fifth refractive index adjusting layer 14 is one quarter of a predetermined wavelength (i.e. λ / 4), and the thickness of the fourth refractive index adjusting layer 13 is one half of the predetermined wavelength (i.e. λ / 2), and the predetermined wavelength λ is in the range of 380 nanometers to 780 nanometers (i.e. the visible light wavelength range).

[0090] It can be understood that the region where the third refractive index adjusting layer 12 is located is the third refractive index adjusting region 4c, the region where the fourth refractive index adjusting layer 13 is located is the first refractive index adjusting region 4a, and the region where the fifth refractive index adjusting layer 14 is located is the second refractive index adjusting region 4b; and the third refractive index adjusting layer 12 is a low refractive index layer, the fourth refractive index adjusting layer 13 is a high refractive index layer, and the fifth refractive index adjusting layer 14 is a low refractive index layer. With Figure 1 and Figure 2 The structure of the optical film 1 shown in Figure 3 The antireflection layer 4 of the optical film 1 shown in

[0091] Figure 3 In the optical film 1 shown, the anti-reflection layer 4 has a gradient of low, high, and low in the direction away from the color adjusting layer 3, and the thickness of each refractive index adjusting layer has a fixed corresponding relationship with the size of the preset wavelength. By using the interference effect of light in the third refractive index adjusting layer 12, the fourth refractive index adjusting layer 13, and the fifth refractive index adjusting layer 14, the reflectivity of the anti-reflection layer 4 can be effectively reduced.

[0092] In this embodiment, the material of the substrate 2 of the optical film 1 includes but is not limited to TAC or PET.

[0093] It should be noted that the third refractive index adjusting layer 12, the fourth refractive index adjusting layer 13, and the fifth refractive index adjusting layer 14 can also adjust the refractive index of each film layer by adding high and low refractive index materials, which will not be described here.

[0094] It can be understood that, Figures 1 to 3 The difference between the structures of the optical films 1 shown is only the structural change of the anti-reflection layer 4, and the anti-reflection layer 4 in the three optical films 1 is only described as an example, and the number of refractive index adjusting regions in the anti-reflection layer 4 is not limited in the embodiments of the present application.

[0095] When the number of refractive index adjusting regions in the anti-reflection layer 4 is greater than 1, the thickness of the low refractive index layer can be further reduced in order to save preparation cost, for example, the thickness of the low refractive index layer ranges from 1 micrometer to 2 micrometers.

[0096] It should be noted that the low refractive index layer described in the embodiments of the present application refers to the anti-reflection layer 4 located in the first refractive index adjusting region 4a or the third refractive index adjusting region 4c.

[0097] In some embodiments, the overall thickness of the optical film 1 ranges from 200 nanometers to 800 nanometers. For example, the overall thickness of the optical film 1 is 200 nanometers, 300 nanometers, 400 nanometers, 500 nanometers, 600 nanometers, 700 nanometers, or 800 nanometers.

[0098] In some embodiments, the light transmittance of the optical film 1 is greater than or equal to 95%. When the display device containing the optical film 1 is configured as a bright state (display state), the arrangement of the optical film 1 does not have a negative impact on the display brightness. Compared with the aforementioned implementation of the dark state integral black effect of the display device by improving the glass cover plate, the embodiments of the present application can maintain the transmittance of the display device at a high level while achieving the integral black effect, thereby ensuring the high efficiency of the display device and being conducive to green environmental protection.

[0099] In some embodiments, when the optical film 1 is applied to a polarizer as a substrate of the polarizer, the reflectivity of the polarizer surface is less than 0.9%, and when the polarizer is applied to the display area of ​​the display device, the color difference value ΔE between the display area and the frame area of ​​the display device is less than 1.2.

[0100] Typically, when ΔE < 2 and reflectivity < 2.5%, the display device exhibits a good overall black effect when the screen is off. However, the optical film 1 provided in this embodiment, through the coordinated material composition and thickness of the color-tuning layer 3 and the anti-reflection layer 4, achieves a ΔE < 1.2 and a reflectivity < 0.9% for the display device. Therefore, the display device using the optical film 1 provided in this embodiment can achieve a very good overall black effect when the screen is off.

[0101] In this embodiment, by providing a color-correcting layer 3 with a functional structure, the hue a can be adjusted while ensuring that the color-correcting layer 3 has high transmittance. and b This value broadens the reflection spectrum of the color tone layer 3; simultaneously, by setting an anti-reflection layer 4 with anti-reflection function, the reflectivity of the optical film 1 surface can be effectively reduced, thereby reducing L. Therefore, through the cooperation of the color-correcting layer 3 and the anti-reflection layer 4, the hue a can be adjusted while ensuring that the optical film 1 has high emissivity. and b Value and decrease L The value is such that when the optical film 1 is applied to a display device, it can effectively reduce the color difference between the display area and the bezel area in the screen-off state, and can effectively reduce the reflectivity of the display device surface, thereby effectively improving the overall black effect of the display device in the screen-off state.

[0102] like Figure 4 As shown, this application embodiment also provides a polarizer 15, which includes a polarizing layer 16 and an optical film 1 as described in any of the foregoing embodiments. The polarizing layer 16 is located on the side of the substrate 2 away from the color-correcting layer 3.

[0103] In one specific embodiment, the reflectivity of the antireflection layer 4 on the side away from the color tone layer 3 is less than 0.9%.

[0104] In some embodiments, the polarizer 15 further includes a pressure-sensitive adhesive layer 17 and a release film 18 located on the side of the polarizer 16 away from the optical film 1.

[0105] Of course, in other embodiments, the polarizer 15 may also include a protective layer (not shown) located on the side of the optical film 1 away from the polarizing layer 16. When the polarizer 15 is applied in a display device, both the protective layer and the release film 18 need to be removed.

[0106] In an embodiment, the material of the polarizing layer 16 includes polyvinyl alcohol (PVA), but is not limited thereto.

[0107] In the embodiments, the optical film 1 described in the foregoing embodiments is applied to the polarizing sheet 15, so that the polarizing sheet 15 has lower reflectivity, higher transmittance and a wider reflection spectrum, and the color phase covering capability of the polarizing sheet 15 at different viewing angles can be effectively improved, which is beneficial to improving the integral black effect of the display device in the off-screen state.

[0108] As shown in FIGS. 1, 2 and 3, the optical film 1 includes a first film 11 and a second film 12. Figure 5 and Figure 6 As shown in FIGS. 1, 2 and 3, the optical film 1 includes a first film 11 and a second film 12.

[0109] In some embodiments, the display module 19 is a liquid crystal display module, but is not limited thereto.

[0110] In some embodiments, the display device 20 further includes an optical shielding layer 23 and a protective cover plate 24, the optical shielding layer 23 is located in the frame area 22, and the protective cover plate 24 is located in the display area 21 and the frame area 22.

[0111] In an embodiment, the optical shielding layer 23 is black ink or a black matrix, the protective cover plate 24 is a glass cover plate, and the optical shielding layer 23 is located between the polarizing sheet 15 and the protective cover plate 24.

[0112] Of course, in other manners, the optical shielding layer 23 can also be located inside the display module 19 and arranged corresponding to the frame area 22.

[0113] In the embodiments, since the color phase covering capability of the polarizing sheet 15 at different viewing angles is improved by applying the optical film 1, the integral black effect of the display device 20 in the off-screen state can be effectively improved.

[0114] In the description of the present application, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0115] In the above embodiments, the description of each embodiment is focused on, and the part not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0116] The embodiments, implementation manners and related technical features of the present application can be combined or replaced with each other without conflict.

[0117] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification made to the above embodiment without departing from the technical solution content of the present application and in accordance with the technical essence of the present application still belongs to the scope of the technical solution of the present application.

Claims

1. An optical film, characterized in that, include: substrate; A color-tone layer is located on one side of the substrate; the material of the color-tone layer is a main material with added metal nanoparticles, and the main material is selected from polyethylene terephthalate; as well as An antireflective layer is located on the side of the color-correcting layer away from the substrate; The antireflective layer is divided into at least one refractive index adjustment region along the direction of the color-correcting layer near the antireflective layer. The refractive index adjustment region includes a first refractive index adjustment region and a second refractive index adjustment region. The second refractive index adjustment region is located on the side of the first refractive index adjustment region away from the color-correcting layer. The refractive index of the antireflective layer located in the second refractive index adjustment region is less than the refractive index of the antireflective layer located in the first refractive index adjustment region.

2. The optical film according to claim 1, characterized in that, The antireflective layer is a single-layer structure.

3. The optical film according to claim 1, characterized in that, The antireflection layer includes a first refractive index adjustment layer disposed in the first refractive index adjustment region and a second refractive index adjustment layer disposed in the second refractive index adjustment region; The refractive index of the second refractive index adjustment layer is less than that of the first refractive index adjustment layer.

4. The optical film according to any one of claims 1 to 3, characterized in that, The antireflection layer is divided into a third refractive index adjustment region and a refractive index adjustment region along the direction of the color-correcting layer near the antireflection layer. The third refractive index adjustment region is located on the side of the first refractive index adjustment region away from the second refractive index adjustment region. The antireflection layer includes a third refractive index adjustment layer disposed in the third refractive index adjustment region, a fourth refractive index adjustment layer disposed in the first refractive index adjustment region, and a fifth refractive index adjustment layer disposed in the second refractive index adjustment region; The refractive index of the fourth refractive index adjustment layer is greater than that of the third and fifth refractive index adjustment layers, and the refractive index of the third refractive index adjustment layer is greater than that of the fifth refractive index adjustment layer.

5. The optical film according to claim 4, characterized in that, The thickness of the third and fifth refractive index adjustment layers is one-quarter of the preset wavelength, and the thickness of the fourth refractive index adjustment layer is one-half of the preset wavelength; the preset wavelength ranges from 380 nanometers to 780 nanometers.

6. The optical film according to claim 1, characterized in that, The thickness of the antireflective layer located in the second refractive index adjustment region ranges from 0.5 micrometers to 15 micrometers.

7. The optical film according to claim 1, characterized in that, The thickness of the color-correcting layer ranges from 0.5 micrometers to 30 micrometers.

8. A polarizer, characterized in that, It includes a polarizing layer and an optical film as described in any one of claims 1 to 7, wherein the polarizing layer is located on the side of the substrate away from the color-correcting layer; and the reflectivity of the antireflective layer on the side away from the color-correcting layer is less than 0.9%.

9. A display device, characterized in that, Includes a display module and a polarizer as described in claim 8, wherein the polarizer is located at least on the light-emitting side of the display module; The display module includes a display area and a border area located on at least one side of the display area; when the display device is configured in a dark state, the difference between the color difference value of the display device located in the display area and the color difference value of the display device located in the border area is less than 1.2.

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