Light Diffusion Film, Polarizer, and Liquid Crystal Display Device

Abstract

This application discloses a light diffusion film, a polarizer including the light diffusion film, and a liquid crystal display device. In the resin layer of the light diffusion film, first particles and second particles are provided. Here, in the longitudinal direction of the first particles, the diameters of the first particles are the same. The second particles include a first end and a second end along its longitudinal direction, and the diameter of the first end gradually decreases in a direction away from the second end.

Description

Technical Field

[0001] This application belongs to the field of display technology, and particularly relates to a light diffusion film, a polarizer, and a liquid crystal display device.

Background Art

[0002] With the development of liquid crystal display technology, liquid crystal display panels tend to be larger in size and have an expanded chromaticity viewing angle. To expand the chromaticity viewing angle of a liquid crystal display panel, usually, a light diffusion film or a light intensity compensation film is attached to the liquid crystal display screen to uniformly diffuse the light of the liquid crystal display panel and compensate for the light intensity at a specific angle. However, when a light diffusion film is attached to the liquid crystal display screen, it affects the contrast of the liquid crystal display panel, resulting in a decrease in the contrast of the liquid crystal display panel.

[0003] In order to expand the viewing angle of a liquid crystal display panel to accommodate a large screen and avoid the impact on the contrast of the liquid crystal display panel, it is necessary to propose a new light diffusion film, polarizer, and liquid crystal display device that can improve the problem of contrast reduction in the wide viewing angle of the liquid crystal display panel.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The object of this application is to provide a light diffusion film, a polarizer, and a liquid crystal display device that can improve the problem of contrast reduction in a large-sized, wide-viewing-angle liquid crystal display panel and improve the display quality.

Means for Solving the Problems

[0005] To solve the above technical problems, this application provides a light diffusion film including a resin layer, and first particles and second particles provided in the resin layer. In the length direction of the first particles, the diameters of the first particles are the same. The second particles include a first end and a second end along its length direction, and the diameter of the first end gradually decreases in a direction away from the second end.

[0006] In the light diffusion film provided by one embodiment of the present application, the diameter of the second particle gradually decreases along the direction from the second end to the first end.

[0007] In the light diffusion film provided by one embodiment of the present application, the diameter of the second end gradually decreases in the direction away from the first end.

[0008] In the light diffusion film provided by one embodiment of the present application, the second particle further includes an intermediate portion, and the first end, the intermediate portion, and the second end are connected in sequence.

[0009] In the length direction of the second particle, the diameter of the intermediate portion is the same, and the diameter of the second end gradually decreases in the direction away from the first end.

[0010] In the light diffusion film provided by one embodiment of the present application, the second particle further includes an intermediate portion, and the first end, the intermediate portion, and the second end are connected in sequence.

[0011] In the length direction of the second particle, the diameter of the intermediate portion is the same, and the diameter of the second end is the same.

[0012] In the light diffusion film provided by one embodiment of the present application, the diameter of the first particle is 0.008 μm to 12.4 μm. The maximum diameter of the second particle is 12.4 μm, and the minimum diameter of the second particle is 0.008 μm.

[0013] In the light diffusion film provided by one embodiment of the present application, the ratio of the mass of all the first particles to the mass of all the second particles is (1 to 10):(90 to 99).

[0014] In the light diffusion film provided by one embodiment of the present application, the total mass of the first particles and the second particles accounts for 10% of the mass of the light diffusion film.

[0015] The second type of particles includes first-type particles and second-type particles, and each of the first-type particles and the second-type particles includes a first end and a second end along its length direction.

[0016] The diameter of the first-type particles gradually decreases along the direction from the second end of the first-type particles to the first end of the first-type particles.

[0017] The diameter of the second end of the second-type particles gradually decreases in the direction away from the first end of the second-type particles.

[0018] The ratio of the mass of all the first particles, the mass of all the first-type particles, and the mass of all the second-type particles is (1 to 10):(40 to 70):(20 to 60).

[0019] In the light-diffusing film provided by an embodiment of the present application, the total mass of the first particles and the second particles accounts for 10% of the mass of the light-diffusing film. The second type of particles includes first-type particles and second-type particles, and each of the first-type particles and the second-type particles includes a first end and a second end along its length direction. The diameter of the first-type particles gradually decreases along the direction from the second end of the first-type particles to the first end of the first-type particles. The second-type particles further include an intermediate portion, and the first end of the second-type particles, the intermediate portion of the second-type particles, and the second end of the second-type particles are connected in sequence. In the length direction of the second-type particles, the diameter of the intermediate portion of the second-type particles is the same, and the diameter of the second end of the second-type particles gradually decreases in the direction away from the first end of the second-type particles.

[0020] The ratio of the mass of all the first particles, the mass of all the first-type particles, and the mass of all the second-type particles is (1 to 10):(40 to 70):(20 to 60).

[0021] In the light diffusion film provided in one embodiment of the present application, the first particles are one or more inorganic particles among calcium carbonate particles, calcium sulfate particles, calcium chloride particles, calcium oxalate particles, magnesium chloride particles, magnesium carbonate particles, magnesium sulfate particles, barium carbonate particles, barium sulfate particles, barium chloride particles, titanium dioxide particles, and zinc oxide particles, or the first particles are one or more organic particles among polymethyl methacrylate particles, polystyrene particles, polycarbonate particles, silicone elastomer particles, butyl acrylate-styrene particles, and poly-4-hydroxybenzyl ester particles. The second particles are one or more inorganic particles among calcium carbonate particles, calcium sulfate particles, calcium chloride particles, calcium oxalate particles, magnesium chloride particles, magnesium carbonate particles, magnesium sulfate particles, barium carbonate particles, barium sulfate particles, barium chloride particles, titanium dioxide particles, and zinc oxide particles, or the second particles are one or more organic particles among polymethyl methacrylate particles, polystyrene particles, polycarbonate particles, silicone elastomer particles, butyl acrylate-styrene particles, and poly-4-hydroxybenzyl ester particles.

[0022] The present application further provides a polarizer including the light diffusion film described in any of the above. The polarizer further includes a substrate, a polarizing functional layer, and a hard coat layer. The substrate is provided between the polarizing functional layer and the hard coat layer. The resin layer is any of the substrate, the polarizing functional layer, and the hard coat layer.

[0023] In the polarizer provided in one embodiment of the present application, the first particles and the second particles are arranged in an oriented manner within the resin layer. The included angle between the length direction of the first particles and the absorption axis of the polarizing functional layer is -10° to 10°. The included angle between the length direction of the second particles and the absorption axis of the polarizing functional layer is -10° to 10°.

[0024] In the polarizer provided in one embodiment of the present application, the diameter of the second particle gradually decreases along the direction from the second end portion to the first end portion.

[0025] In the polarizer provided in one embodiment of the present application, the diameter of the second end portion gradually decreases in the direction away from the first end portion.

[0026] In the polarizer provided in one embodiment of the present application, the second particle further includes an intermediate portion, and the first end portion, the intermediate portion, and the second end portion are connected in sequence. In the longitudinal direction of the second particle, the diameter of the intermediate portion is the same, and the diameter of the second end portion gradually decreases in the direction away from the first end portion.

[0027] In the polarizer provided in one embodiment of the present application, the second particle further includes an intermediate portion, and the first end portion, the intermediate portion, and the second end portion are connected in sequence. In the longitudinal direction of the second particle, the diameter of the intermediate portion is the same, and the diameter of the second end portion is the same.

[0028] In the polarizer provided in one embodiment of the present application, the diameter of the first particle is 0.008 μm to 12.4 μm, the maximum diameter of the second particle is 12.4 μm, and the minimum diameter of the second particle is 0.008 μm.

[0029] In the polarizer provided in one embodiment of the present application, the ratio of the mass of all the first particles to the mass of all the second particles is (1 to 10):(90 to 99).

[0030] In the polarizer provided in one embodiment of the present application, the total mass of the first particle and the second particle accounts for 10% of the mass of the light diffusing film. The second particle includes a first type of particle and a second type of particle, and each of the first type of particle and the second type of particle includes a first end portion and a second end portion along its longitudinal direction. The diameter of the first type of particles gradually decreases along the direction from the second end to the first end of the first type of particles. The diameter of the second end of the second type of particles gradually decreases in the direction away from the first end of the second type of particles. The ratio of the mass of all the first particles, the mass of all the first type of particles, and the mass of all the second type of particles is (1 to 10):(40 to 70):(20 to 60).

[0031] The present application further provides a liquid crystal display device including a liquid crystal display panel and a polarizer as described in any one of the above, wherein the polarizer is provided on the light emitting side of the liquid crystal display panel. Here, the polarizer includes a light diffusion film, the light diffusion film includes a resin layer, and first particles and second particles provided in the resin layer. In the length direction of the first particles, the diameters of the first particles are the same. The second particles include a first end and a second end along their length direction. The diameter of the first end gradually decreases in the direction away from the second end. The polarizer further includes a base material, a polarizing functional layer, and a hard coat layer. The base material is provided between the polarizing functional layer and the hard coat layer. The resin layer is any one of the base material, the polarizing functional layer, and the hard coat layer.

Advantages of the Invention

[0032] In the present application, by providing the first particles and the second particles in the resin layer of the light diffusion film, the light diffusion film has a scattering effect, and the contrast of the display panel to which the light diffusion film is attached is improved. Here, in the length direction of the first particles, the diameters of the first particles are the same. The second particles include a first end portion and a second end portion along its length direction, and the diameter of the first end portion gradually decreases in a direction away from the second end portion. Both the first particles and the second particles can impart a scattering effect to the light diffusion film, and can improve the chromaticity viewing angle of the polarizer to which the light diffusion film is attached. Then, by mixing the second particles and the first particles, the influence on the contrast of the display panel to which the light diffusion film is attached is reduced, and the contrast of the display panel to which the light diffusion film is attached is improved.

Brief Description of the Drawings

[0033]

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Embodiments for Carrying Out the Invention

[0034] Hereinafter, with reference to the accompanying drawings in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. It is obvious that the described embodiments are only a part of the embodiments of the present application, not all of them. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present application.

[0035] In the description of the present application, the directions and positional relationships indicated by "up", "down", "front", "rear", "left", "right", "inside", "outside", etc. are based on the directions or positional relationships shown in the drawings, and do not imply or suggest that the devices or elements mentioned must have a specific direction and be constructed and operated in a specific direction. It is merely for the convenience of the description and simplification of the present application, and therefore, it should be understood that it should not be construed as limiting the present application.

[0036] The embodiments of the present application provide a light diffusion film, a polarizer, and a liquid crystal display device, which will be described in detail below. Note that the order of description of the following embodiments does not limit the preferred order of the embodiments.

[0037] Referring to FIGS. 1 and 2, an embodiment of the present application provides a light diffusion film 10 including a resin layer 1, and first particles 2 and second particles 3 provided in the resin layer 1. Here, in the length direction of the first particles 2, the diameters of the first particles 2 are the same. The second particles 3 include a first end D1 and a second end D2 along its length direction, and the diameter of the first end D1 gradually decreases in a direction away from the second end D2.

[0038] In the present application, by providing the first particles 2 and the second particles 3 in the resin layer 1 of the light diffusion film 10, the light diffusion film 10 has a scattering effect, and the contrast of the display panel to which the light diffusion film 10 is attached is improved. Here, in the length direction of the first particles 2, the diameters of the first particles 2 are the same. The second particles 3 include a first end D1 and a second end D2 along its length direction, and the diameter of the first end D1 gradually decreases in a direction away from the second end D2. Both the first particles 2 and the second particles 3 can endow the light diffusion film 10 with a scattering effect, and can improve the chromaticity viewing angle of the polarizer 100 to which the light diffusion film 10 is attached. And by mixing the second particles 3 and the first particles 2, the influence on the contrast of the display panel to which the light diffusion film 10 is attached is reduced, and the contrast of the display panel to which the light diffusion film 10 is attached is improved.

[0039] Note that the contrast in the present application means the ratio of the luminance in the bright state to the luminance in the dark state of the display panel. When only the first particles 2 with uniform diameters, that is, only cylindrical particles with good light scattering effects, are provided in the light diffusion film 10, in the dark state, external ambient light is scattered by the first particles 2, and the luminance of the display panel becomes relatively high. In the bright state, the light emitted from the light-emitting unit is scattered by the first particles 2, and since the luminance of the display panel is uniformly diffused, the luminance becomes small, and due to the combined effect, the contrast of the display panel is significantly reduced. The second particles 3 whose diameter gradually decreases in the direction away from the second end D2 have a weaker scattering effect than the first particles 2. When both the first particles 2 and the second particles 3 are provided in the light diffusion film 10, in the dark state, external ambient light is scattered by the mixed particles, and the luminance of the display panel becomes relatively low. In the bright state, the light emitted from the light-emitting unit is scattered by the mixed particles, and the luminance of the display panel becomes relatively high. Due to the combined effect, the light diffusion film 10 has a scattering effect, and the influence on the contrast of the display panel to which the light diffusion film 10 is attached is reduced, and the contrast is improved.

[0040] Also, when only the first particles 2 with uniform diameters, that is, only cylindrical particles, are provided in the light diffusion film 10, the transmittance of the light diffusion film 10 is also slightly lower than the transmittance when the first particles 2 and the second particles 3 are mixed.

[0041] Preferably, the thickness of the resin layer 1 exceeds 3 microns and is less than 50 microns. Specifically, the thickness of the resin layer 1 may be 4 microns, 5 microns, 6 microns, 10 microns, 12 microns, 15 microns, 17 microns, 18 microns, 20 microns, 24 microns, 25 microns, 26 microns, 30 microns, 33 microns, 35 microns, 38 microns, 40 microns, 45 microns, or 48 microns.

[0042] Preferably, the first particles 2 and the second particles 3 may be one or more inorganic particles among calcium carbonate particles, calcium sulfate particles, calcium chloride particles, calcium oxalate particles, magnesium chloride particles, magnesium carbonate particles, magnesium sulfate particles, barium carbonate particles, barium sulfate particles, barium chloride particles, titanium dioxide particles, and zinc oxide particles. The first particles 2 and the second particles 3 may also be one or more organic particles among polymethyl methacrylate particles, polystyrene particles, polycarbonate particles, silicone elastomer particles, butyl acrylate-styrene particles, and poly-4-hydroxybenzyl ester particles.

[0043] Referring to FIG. 3, in this embodiment, the diameter of the second particles 3 gradually decreases along the direction from the second end D2 to the first end D1. That is, the second particles 3 have an elongated conical shape.

[0044] It can be understood that the elongated conical second particles 3 have a weaker scattering effect than the first particles 2. By mixing and providing the second particles 3 and the first particles 2 in the resin layer 1, the light diffusion film 10 can be provided with a scattering effect, and the influence on the contrast of the display panel to which the light diffusion film 10 is attached is small, and the contrast is better.

[0045] In this embodiment, the diameter of the first particles 2 is 0.008 microns to 12.4 microns. The second particles 3 have a maximum diameter of 12.4 microns and a minimum diameter of 0.008 microns.

[0046] Specifically, the diameter of the first particle 2 may be 0.008 microns, 0.01 microns, 0.05 microns, 0.1 microns, 0.5 microns, 1 micron, 1.4 microns, 2 microns, 2.5 microns, 3 microns, 3.6 microns, 5 microns, 5.7 microns, 6 microns, 8 microns, 9 microns, 10 microns, 11 microns, 12 microns, or 12.4 microns, etc. It can be easily understood that the fact that the diameter is the same anywhere in the longitudinal direction of the first particle 2 means that the diameter deviation of the cylindrical particle is within ±20%. For example, the diameter of the first particle 2 is 1 micron, and there is a deviation of ±20% in the diameter at each location, that is, the diameter at each location is in the range of 0.8 microns to 1.2 microns.

[0047] The maximum diameter of the second particle 3 may be 0.5 microns, 1 micron, 1.4 microns, 2 microns, 2.5 microns, 3 microns, 3.6 microns, 5 microns, 5.7 microns, 6 microns, 8 microns, 9 microns, 10 microns, 11 microns, 12 microns, or 12.4 microns, etc., and the minimum diameter may be 0.008 microns, 0.01 microns, 0.05 microns, 0.1 microns, 0.5 microns, 1 micron, 1.4 microns, 2 microns, 2.5 microns, 3 microns, 3.6 microns, 5 microns, 5.7 microns, 6 microns, 8 microns, 9 microns, or 10 microns, etc. It can be easily understood that the maximum diameter of the second particle 3 is larger than the minimum diameter.

[0048] Preferably, the ratio of the length to the radius of the particle is greater than 1. Specifically, the ratio of the length to the radius of the particle may be 1.5, 2, 2.5, 3, or 5, etc.

[0049] In the present application, by setting the diameter of the first particle 2 to be 0.008 microns to 12.4 microns, the maximum diameter of the second particle 3 to be 12.4 microns, and the minimum diameter to be 0.008 microns, the light passing through the light diffusion film 10 can be Mie-scattered, the scattering effect becomes better, and when the light diffusion film 10 is attached to the display panel, it is advantageous for improving the chromaticity viewing angle.

[0050] Specifically, scattering includes Mie scattering and Rayleigh scattering. Mie scattering means that when light hits particles with a diameter greater than the wavelength of the light, the light is mainly scattered along the original direction of propagation. That is, the intensity of the light scattered in the direction of light propagation is greater than the intensity of the light scattered in the opposite direction of light propagation. On the other hand, the light subjected to Rayleigh scattering is scattered more uniformly in the direction of light propagation and the opposite direction of light propagation. That is, along the direction of light propagation, the light intensity of Rayleigh scattering is smaller than the light intensity of Mie scattering. Therefore, due to the Mie scattering of the light passing through the light diffusion film 10, a better scattering effect is obtained and the light loss is reduced.

[0051] Mie scattering and Rayleigh scattering are usually distinguished by the size of light and particles, and different processing methods are used according to the relative size of particles and the wavelength of light. In the present application, a dimensionless quantity is used as a criterion for discrimination, and the dimensionless quantity is a function of the ratio of the particle radius to the radiation wavelength, and the formula is α = 2πr / λ. Here, α is the dimensionless quantity, r is the particle radius, and λ is the wavelength of light. When the diameter of the particle is 0.008 μm to 12.4 μm, that is, when the radius of the particle is 0.004 μm to 6.2 μm, and the dimensionless quantity α is 0.1 or more and less than 50, that is, when the dimensionless quantity α is in this range, Mie scattering of light occurs. When the dimensionless quantity α is significantly smaller than 0.1, Rayleigh scattering of light occurs. The change in the scattering intensity is a function of the ratio of the particle radius to the radiation wavelength. Referring to FIG. 4, FIG. 4 is a schematic diagram showing the relationship between the scattering intensity and the scale number. Here, the horizontal axis is the scale number α, and the vertical axis is the scattering intensity I. When the scale number α is 0.1 or more, as the scale number α increases, the light scattering intensity I increases and finally stabilizes near 1.

[0052] In this embodiment, the ratio of the mass of all the first particles 2 to the mass of all the second particles 3 is (1 to 10):(90 to 99). Specifically, the ratio of the mass of all the first particles 2 to the mass of all the second particles 3 is 1:99, 2:98, 3:97, 4:96, 5:95, 6:94, 7:93, 8:92, 9:91, or 10:90.

[0053] When the mass ratio of the first particle 2 to the second particle 3 is within this range, it can be understood that when the light diffusion film 10 is attached to the display panel, the chromaticity viewing angle and the contrast become relatively large.

[0054] Referring to FIGS. 5 and 6, an embodiment of the present application provides a light diffusion film 10. The difference between this embodiment and the embodiment of FIG. 1 is that the diameter of the second end portion gradually decreases in a direction away from the first end portion. That is, the second particle 3 of this embodiment has a double conical shape.

[0055] It can be understood that the double conical second particle 3 has a weaker scattering effect than the first particle 2. By mixing and providing the second particle 3 and the first particle 2 in the resin layer 1, the light diffusion film 10 can be provided with a scattering effect, and the influence on the contrast of the display panel to which the light diffusion film 10 is attached is small, and the contrast is better.

[0056] Referring to FIGS. 7 and 8, an embodiment of the present application provides a light diffusion film 10. The differences between this embodiment and the embodiments of FIGS. 1 and 5 are that the second particle 3 further includes an intermediate portion D3, and the first end portion D1, the intermediate portion D3, and the second end portion D2 are connected in sequence. In the longitudinal direction of the second particle 3, the diameters of the intermediate portions D3 are the same. The diameter of the second end portion D2 gradually decreases in a direction away from the first end portion D1. That is, the second particle 3 of this embodiment includes particles having a cylindrical center and conical ends.

[0057] It can be understood that the second particle 3 having a cylindrical center and conical ends has a weaker scattering effect than the first particle 2. By mixing and providing the second particle 3 and the first particle 2 in the resin layer 1, the light diffusion film 10 can be provided with a scattering effect, and the influence on the contrast of the display panel to which the light diffusion film 10 is attached is small, and the contrast is better.

[0058] Referring to FIGS. 9 and 10, another embodiment of the present application provides a light diffusing film 10. The difference between this embodiment and the embodiment of FIG. 1 is that the second particle 3 further includes an intermediate portion D3, and the first end portion D1, the intermediate portion D3, and the second end portion D2 are connected in sequence. In the longitudinal direction of the second particle 3, the diameters of the intermediate portions D3 are the same, and the diameters of the second end portions D2 are the same. That is, the second particle 3 of this embodiment includes a particle in which the first end portion D1 is conical and the remaining portion is cylindrical.

[0059] It can be understood that the second particle 3 in which the first end portion D1 is conical and the remaining portion is cylindrical has a weaker scattering effect than the first particle 2. By mixing and providing the second particle 3 and the first particle 2 in the resin layer 1, the light diffusing film 10 can be provided with a scattering effect, and the influence on the contrast of the display panel to which the light diffusing film 10 is attached is small, and the contrast is better.

[0060] Referring to FIGS. 11 and 12, another embodiment of the present application provides a light diffusing film 10. The difference between this embodiment and the embodiments of FIGS. 1 and 5 is that the second particle 3 includes a first type of particle 3a and a second type of particle 3b. Each first type of particle 3a and each second type of particle 3b include a first end portion D1 and a second end portion D2 along their longitudinal directions. The diameter of the first type of particle 3a gradually decreases along the direction from the second end portion D2 to the first end portion D1 of the first type of particle 3a. The diameter of the first end portion D1 of the second type of particle 3b gradually decreases in the direction away from the second end portion D2 of the second type of particle 3b. The diameter of the second end portion D2 of the second type of particle 3b gradually decreases in the direction away from the first end portion D1 of the second type of particle 3b. That is, the second particle 3 of this embodiment includes long conical particles and bi-conical particles.

[0061] It can be understood that the second particle 3 including the long conical first type of particle 3a and the double conical second type of particle 3b has a weaker scattering effect than the first particle 2. By mixing and providing the second particle 3 and the first particle 2 in the resin layer 1, the light diffusion film 10 can be given a scattering effect, and the influence on the contrast of the display panel to which the light diffusion film 10 is attached is small, and the contrast becomes better.

[0062] In addition, the second particles 3 of each embodiment of the present application can be arbitrarily combined. As an example, the second particle 3 may include long conical particles and double conical particles. As another example, the second particle 3 may include long conical particles, double conical particles, and particles having a conical first end D1 and a cylindrical remaining portion. The second particle 3 may also be a combination of double conical particles and particles having a conical first end D1 and a cylindrical remaining portion. Alternatively, the second particle 3 is a combination of long conical particles and particles having conical first end D1 and second end D2 and a cylindrical central portion. The present application does not limit this.

[0063] In this embodiment, the ratio of the mass of all the first particles 2, the mass of all the first type of particles 3a, and the mass of all the second type of particles 3b is (1 to 10):(40 to 70):(20 to 60). Specifically, the ratio of the mass of all the first particles 2, the mass of all the first type of particles 3a, and the mass of all the second type of particles 3b may be 1:40:59, 2:42:56, 3:45:52, 4:48:48, 5:70:25, 5:69:26, 6:68:26, 7:55:38, 8:55:37, or 9:52:39.

[0064] When the mass ratio of the first particle 2, the first type of particle 3a, and the second type of particle 3b is within this range, it can be understood that when the light diffusion film 10 is attached to the display panel, the chromaticity viewing angle and the contrast become relatively large.

[0065] Furthermore, when the ratio of the mass of all the first particles 2, the mass of all the first-type particles 3a, and the mass of all the second-type particles 3b is (50 - 55):(1 - 5):(45 - 50), the display panel with the light diffusion film 10 attached thereto can achieve a chromaticity viewing angle of 160 degrees or more and a contrast of 2800 or more. Specifically, the ratio of the mass of all the first particles 2, the mass of all the first-type particles 3a, and the mass of all the second-type particles 3b is 50:5:45, 51:4:45, 52:3:45, 53:2:45, or 54:1:45.

[0066] Preferably, the total mass of the first particles 2, the first-type particles 3a, and the second-type particles 3b accounts for 1% - 30% of the mass of the light diffusion film 10. Specifically, the total mass of the first particles 2, the first-type particles 3a, and the second-type particles 3b accounts for 1%, 2%, 5%, 7%, 8%, 10%, 15%, 20%, or 30% of the mass of the light diffusion film 10. When the total mass of the first particles 2, the first-type particles 3a, and the second-type particles 3b is within this range, the light diffusion film 10 can have a strong scattering effect and a high light transmittance.

[0067] In this embodiment, when the total mass of the first particles 2, the first-type particles 3a, and the second-type particles 3b accounts for 10% of the mass of the light diffusion film 10, the display panel with the light diffusion film 10 attached thereto can achieve a chromaticity viewing angle of 160 degrees or more and a transmittance of 4.65% or more.

[0068] The light diffusion film 10 of the present application may be attached to the light-emitting side of the backlight module in order to improve the light diffusion of the backlight module. Further, it may be attached to the light-emitting side of the lamp, and the light diffusion of the LED lamp can be improved. Further, it may be attached to the light-emitting surface of the vehicle display panel, and the viewing angle of the vehicle display panel can also be improved.

[0069] The present application further provides a polarizer 100 including the light diffusion film 10 described in any of the above. Here, the material of the resin layer 1 of the light diffusion film 10 can be selected from polyurethane resin, acrylic resin, epoxy resin, vinyl resin, silicone resin, polyvinyl alcohol, and the like. It can be understood that the material and characteristics of the resin layer 1 can vary according to its specific position within the polarizer 100. Hereinafter, different embodiments of the polarizer 100 of the present application will be described.

[0070] According to some embodiments of the present application, the polarizer 100 includes the light diffusion film 10 described in any of the above. The polarizer 100 further includes a first substrate 15, a second substrate 17, and a polarization function layer 14. The first substrate 15 and the second substrate 17 are respectively provided on opposite sides of the light diffusion film 10, and the polarization function layer 14 is provided on the side of the first substrate 15 away from the light diffusion film 10. Preferably, the resin layer 1 of the light diffusion film 10 functions as an adhesive layer for bonding the first substrate 15 and the second substrate 17. Preferably, the polarizer 100 further includes an adhesive layer provided between the first substrate 15 and the light diffusion film 10 for bonding the first substrate 15 and the light diffusion film 10.

[0071] Referring to FIG. 13, in the embodiment where the resin layer 1 of the light diffusion film 10 is used as the adhesive layer, as shown in FIG. 13, the polarizer 100 includes a release film 11, a first adhesive layer 12, an optical compensation layer 13, a polarization function layer 14, a first substrate 15, a second adhesive layer 16, a second substrate 17, a hard coat layer 18, an antireflection layer 19, and a protective layer 21 laminated in sequence. When the polarizer 100 is in use, the direction from the release film 11 to the protective layer 21 is the lamination direction of the film layers in the polarizer 100 and also the light incident direction. In this embodiment, the first particles 2 and the second particles 3 are provided in the second adhesive layer 16, that is, the resin layer 1 of the light diffusion film 10 is the second adhesive layer 16.

[0072] The function of the release film 11 is to protect the adhesive layer from damage and prevent air bubbles during lamination before the polarizer 100 is attached to the liquid crystal display panel 200. The release film 11 may be a polyester film such as a polyethylene terephthalate film, a polyolefin film such as a polyethylene film or a polypropylene film, or a polytetrafluoroethylene-based film. A film treated with a release agent such as a siloxane-based resin, a melamine-based resin, or a urea-based resin may be used so that the release film 11 can be easily peeled off.

[0073] The first pressure-sensitive adhesive (PSA) layer 12 is provided on one side of the release film 11. The first adhesive layer 12 is an adhesive layer for adhering the release film 11 and a film layer such as a polarizing functional layer 14 provided on the release film 11. The material of the first adhesive layer 12 may be, for example, an acrylic resin.

[0074] The optical compensation layer 13 is provided on the side of the first adhesive layer 12 away from the release film 11. The optical compensation layer 13 may be a compensation layer or a retardation film obtained by applying a liquid crystalline compound to the surface of the substrate 15 and fixing the orientation.

[0075] The polarizing functional layer 14 is provided on the side of the optical compensation layer 13 away from the first adhesive layer 12. The polarizing functional layer 14 may contain polyvinyl alcohol. Specifically, the polarizing functional layer 14 may contain a polyvinyl alcohol film dyed with iodine or a polyene-based compound obtained by dehydrating a polyvinyl alcohol film.

[0076] The first substrate 15 is provided on the side away from the optical compensation layer 13 of the polarization functional layer 14. The first substrate 15 is used to protect the polarization functional layer 14 and support the film layer on the first substrate 15. The first substrate 15 may include at least one selected from cellulose ester resins including triacetyl cellulose (TAC), cyclic polyolefin resins including amorphous cyclic polyolefin (COP), polycarbonate resins, polyester resins including polyethylene terephthalate (PET), polyethersulfone resins, polysulfone resins, polyamide resins, polyimide resins, acyclic polyolefin resins, polyacrylic resins including polymethyl methacrylate resins, polyvinyl alcohol resins, polyvinyl chloride resins, and polyvinylidene chloride resins, but is not limited thereto. Specifically, the material of the first substrate 15 is polyethylene terephthalate (PET).

[0077] The second adhesive layer 16 is provided on the side away from the polarization functional layer 14 of the first substrate 15. The second adhesive layer 16 is the same as the first adhesive layer 12 as an adhesive layer for bonding the first substrate 15 and the second substrate 17. Since the selectable materials of the second adhesive layer 16 are the same as those of the first adhesive layer 12, the description is omitted here.

[0078] The second substrate 17 is provided on the side away from the first substrate 15 of the second adhesive layer 16. The second substrate 17 is used to support the film layer on the second substrate 17. Since the selectable materials of the second substrate 17 are the same as those of the first substrate 15, the description is omitted here. Specifically, the material of the second substrate 17 is polyethylene terephthalate (PET).

[0079] The hard coat layer 18 is provided on the side away from the second adhesive layer 16 of the second base material 17. Since the hard coat layer 18 has high hardness, water resistance, and oil resistance, it can preferably prevent the surface of the lower film layer from being damaged and facilitate cleaning. Preferably, the hard coat layer 18 has a relatively high glass transition temperature, for example, a glass transition temperature of 70°C to 120°C. The material of the hard coat layer 18 can be selected from polyurethane resins, acrylic resins, epoxy resins, vinyl resins, and silicone resins.

[0080] The anti-reflection layer 19 (Anti-Reflection, AR) is provided on the side away from the second base material 17 of the hard coat layer 18. The anti-reflection layer 19 is for the purpose of anti-reflection and preventing scratches. The anti-reflection layer 19 is, for example, a dielectric thin film formed on the surface of the hard coat layer 18.

[0081] The surface protection layer 21 is used to protect the film layer below it. The surface protection layer 21 may be a transparent resin film formed from a thermoplastic resin such as a chain polyolefin resin (such as a polypropylene resin), a cyclic polyolefin resin (such as a norbornene resin), etc., a cellulose ester resin such as cellulose triacetate or cellulose diacetate, a polyester resin such as polyethylene terephthalate, polyethylene naphthalate, or polybutylene terephthalate, a polycarbonate resin, a (meth)acrylic resin, or a mixture or copolymer thereof.

[0082] Also, the polarizer 100 may further have other film layers such as an antistatic layer in addition to the above film layers, but detailed description thereof is omitted here.

[0083] Referring to FIG. 14, the polarizer 100 adhered by an adhesive layer between the first substrate 15 and the light diffusion film 10, as shown in FIG. 14, the difference between the embodiment of FIG. 14 and the embodiment of FIG. 13 is that the first particles 2 and the second particles 3 are not dispersed in the second adhesive layer 16, the light diffusion film 10 is provided on the second adhesive layer 16, this light diffusion film 10 includes a resin layer 1, and the first particles 2 and the second particles 3 are dispersed in this resin layer 1.

[0084] The material of the resin layer 1 can be selected from polyurethane resin, acrylic resin, epoxy resin, vinyl resin, and silicone resin.

[0085] According to some embodiments of the present application, the polarizer 100 includes the light diffusion film 10 described in any of the above, and further includes a substrate 15, a polarization functional layer 14, and a hard coat layer 18. The substrate 15 is provided between the polarization functional layer 14 and the hard coat layer 18. The resin layer 1 is any one of the substrate 15, the polarization functional layer 14, and the hard coat layer 18.

[0086] Referring to FIG. 15, the polarizer 100 in which the resin layer 1 of the light diffusion film 10 is the hard coat layer 18, as shown in FIG. 15, the difference between the embodiment of FIG. 15 and the embodiment of FIG. 13 is that the first particles 2 and the second particles 3 are not dispersed in the second adhesive layer 16, but are dispersed in the hard coat layer 18, and in this embodiment, the second substrate 17 and the second adhesive layer 16 are omitted, and only one substrate 15 needs to be provided. By omitting the second substrate 17, the structure of the polarizer 100 can be simplified, and since the layer of the substrate 15 is omitted, its luminance and contrast are improved.

[0087] Referring to FIG. 16, in the embodiment where the resin layer 1 of the light diffusion film 10 is the substrate 15, as shown in FIG. 16, the difference between the embodiment of FIG. 16 and the embodiment of FIG. 15 is that the first particles 2 and the second particles 3 are not dispersed in the hard coat layer 18, but are dispersed in the substrate 15, and in this embodiment as well, only one substrate 15 needs to be provided. In this structure, the substrate 15 and the polarization functional layer 14 can be manufactured together by a stretching process.

[0088] Referring to FIG. 17, in the embodiment where the resin layer 1 of the light diffusion film 10 is the polarization functional layer 14, as shown in FIG. 17, the difference between the embodiment of FIG. 17 and the embodiment of FIG. 15 is that the first particles 2 and the second particles 3 are not dispersed in the hard coat layer 18 but are dispersed in the polarization functional layer 14, and in this embodiment as well, only one substrate 15 needs to be provided. In this structure, the polarization functional layer 14 can be produced by a stretching process.

[0089] In this embodiment, the first particles 2 and the second particles 3 are arranged in an oriented manner within the resin layer 1. The included angle between the length direction of the first particles 2 and the absorption axis of the polarization functional layer 14 is -10° to 10°. The included angle between the length direction of the second particles 3 and the absorption axis of the polarization functional layer 14 is -10° to 10°. When the polarizer 100 is attached to the display film layer, it can be understood that due to the oriented arrangement of the first particles 2 and the second particles 3 in the resin layer 1, the viewing angle of the display panel is enlarged in the direction perpendicular to the absorption axis.

[0090] Specifically, the process of arranging the first particles 2 and the second particles 3 in an oriented manner within the resin layer 1 may be coating, casting, or stretching. For example, in the embodiment of FIG. 15, the first particles 2 and the second particles 3 are dispersed in the hard coat layer 18. The hard coat layer 18 is formed by coating, and in the coated hard coat layer 18, the first particles 2 and the second particles 3 are arranged in an oriented manner. As an example, in the embodiment of FIG. 16, the first particles 2 and the second particles 3 are dispersed in the substrate 15, and the substrate 15 is attached to the polarization functional layer 14. The substrate 15 and the polarization functional layer 14 are produced together by a stretching process, and the first particles 2 and the second particles 3 are arranged in an oriented manner within the stretched substrate 15. As another example, in the embodiment of FIG. 17, the first particles 2 and the second particles 3 are dispersed in the polarization functional layer 14. The polarization functional layer 14 is produced by a stretching process, and in the stretched polarization functional layer 14, the first particles 2 and the second particles 3 are arranged in an oriented manner.

[0091] This application further provides a method for manufacturing a polarizer 100. Referring to FIGS. 18 and 19, the manufacturing of the polarizer 100 in which the first particles 2 and the second particles 3 are provided in the adhesive layer includes the following steps.

[0092] Step S1: Mix the raw material of the resin layer 1 with the particles to form a mixture. Here, the particles include the first particles 2 and the second particles 3. In the length direction of the first particles 2, the diameters of the first particles 2 are the same. The second particles 3 include a first end D1 and a second end D2 along its length direction, and the diameter of the first end D1 gradually decreases in the direction away from the second end D2.

[0093] Step S2: Provide a substrate 15 and form a light diffusion film 10 on one side of the substrate 15.

[0094] Step S3: Provide a polarizer substrate film and attach the light diffusion film 10 to the upper surface of the polarizer substrate film to form a polarizer 100.

[0095] Hereinafter, the procedure of this manufacturing method will be introduced in detail.

[0096] Step S1: Mix the raw material of the resin layer 1 with the particles to form a mixture. Here, the particles include the first particles 2 and the second particles 3. In the length direction of the first particles 2, the diameters of the first particles 2 are the same. The second particles 3 include a first end D1 and a second end D2 along its length direction, and the diameter of the first end D1 gradually decreases in the direction away from the second end D2.

[0097] Specifically, the raw material of the resin layer 1 is an adhesive raw material. The mass of the added adhesive raw material is 200 kg. Here, the adhesive content is 15.78%.

[0098] Specifically, the particles are calcium carbonate particles, and the total mass of the particles is 3.156 kg. Here, the particles include first particles 2 and second particles 3. The first particles 2 are cylindrical particles, and the second particles 3 include first-type particles 3a and second-type particles 3b. Each first-type particle 3a and each second-type particle 3b include a first end D1 and a second end D2 along their length directions. The diameter of the first-type particle 3a gradually decreases along the direction from the second end D2 to the first end D1 of the first-type particle 3a. The diameter of the first end D1 of the second-type particle 3b gradually decreases in the direction away from the second end D2 of the second-type particle 3b. The diameter of the second end D2 of the second-type particle 3b gradually decreases in the direction away from the first end D1 of the second-type particle 3b. That is, the first-type particle 3a is a long conical particle, and the second-type particle 3b is a double conical particle.

[0099] The mass of the first particles 2 is 0.063 kg, the mass of the first-type particles 3a is 1.67 kg, and the mass of the second-type particles 3b is 1.42 kg. That is, the ratio of the mass of all the first particles 2, the mass of all the first-type particles 3a, and the mass of all the second-type particles 3b is 53:2:45.

[0100] Preferably, keep the viscosity of the mixture at 1000 centipoise to 2000 centipoise, which is 1 Pascal to 2 Pascals when converted to international units. It can be understood that when the viscosity of the mixture is within this range, it is easy to flow and easy to apply.

[0101] Preferably, a silane coupling agent, a curing agent, and ethyl acetate are mixed with the raw material of the resin layer 1 to form a mixture, and the cross-linking and curing of the mixture can also be promoted. Here, the mass of the silane coupling agent is 0.09 kg, and the mass of the curing agent is 0.14 kg.

[0102] Preferably, after the mixture is stirred at room temperature of 25 °C for 1 hour, it is left standing for 2 hours. It can be understood that by stirring, the particles in the adhesive raw material are mixed more uniformly, and by standing, the mixture defoams, that is, the bubbles in the mixture overflow.

[0103] Step S2: Provide the substrate 15 and form the light diffusing film 10 on one surface of the substrate 15.

[0104] Specifically, provide the substrate 15, apply a mixture on one surface of the substrate 15, and after curing the mixture, form the light diffusing film 10. The light diffusing film 10 is attached to one surface of the substrate 15.

[0105] Preferably, baking the substrate 15 coated with the mixture is advantageous for forming the light diffusing film 10.

[0106] Preferably, the thicknesses of the substrate 15 and the light diffusing film 10 are 25 microns.

[0107] Step S3: Provide the polarizer substrate film and attach the light diffusing film 10 to the upper surface of the polarizer substrate film to form the polarizer 100.

[0108] Specifically, attach the light diffusing film 10 as an adhesive layer to the upper surface of the polarizer substrate film to form a composite polarizer substrate film. Cut the composite polarizer substrate film into a length of 1438 mm and a width of 812 mm to form the polarizer 100.

[0109] Preferably, the above-mentioned substrate 15 is the second substrate 17, and the polarizer substrate film includes a release film 11, a first adhesive layer 12, an optical compensation layer 13, a polarizing functional layer 14, and a first substrate 15 laminated in sequence. The light diffusing film 10 is attached as a second adhesive layer 16 to the surface of the first substrate 15 away from the polarizing functional layer 14. The second substrate 17 is attached with the light diffusing film 10 as an adhesive layer to the side of the first substrate 15 away from the polarizing functional layer 14.

[0110] Up to this point, the manufacture of the polarizer 100 is completed.

[0111] Referring to FIG. 20, the present application further provides a liquid crystal display device 1000 including the above-described polarizer 100 and a liquid crystal display panel 200, wherein the polarizer 100 is provided on the light-emitting side of the liquid crystal display panel 200. That is, the polarizer 100 of the present application is used as the upper polarizer 100 of the liquid crystal display device 1000. The liquid crystal display device 1000 further includes structures such as a backlight module and a lower polarizer provided on the light-incident side of the liquid crystal display panel 200, but the description thereof is omitted here.

[0112] In the present application, several tests were continuously conducted to test the optical effect of the light diffusion film 10 in a specific embodiment of the present application.

[0113] In this test, the resin layer 1 of the light diffusion film 10 is the second adhesive layer 16, and the thickness of the second adhesive layer 16 is 20 microns. The lengths of the first particles 2 and the second particles 3 in the resin layer 1 are 10 to 30 microns, and the diameters are 1 to 3 microns. In this test, the light diffusion film 10 was provided as the second adhesive layer 16 on the polarizer 100, and the polarizer 100 was attached to the surface of a 75-inch liquid crystal display panel 200 to test the optical effect. The tested polarizer 100 includes a release film 11, a first adhesive layer 12, an optical compensation layer 13, a polarizing function layer 14, a first substrate 15, a second adhesive layer 16 (light diffusion film 10), a second substrate 17, a hard coat layer 18, an antireflection layer 19, and a protective layer 21 laminated in sequence.

[0114] Note that L1 refers to the first particle 2. In the length direction of the first particle 2, the diameter of the first particle 2 is the same, that is, it is a cylindrical particle. L2 refers to a particle among the second particles 3 whose diameter gradually decreases along the direction from the second end D2 of the particle to the first end D1, that is, a long conical particle. L3 refers to the second particle 3 whose diameter of the second end D2 of the particle gradually decreases in the direction away from the first end D1 of the particle, and the diameter of the first end D1 of the particle gradually decreases in the direction away from the second end D2 of the particle, that is, a bi-conical particle.

[0115] The contrast CR means the ratio of the luminance of the display panel in the bright state to the luminance in the dark state. In this test, the central luminance of the display panel in the bright state and the central luminance of the display panel in the dark state are measured.

[0116] The chromaticity viewing angle measurement is a viewing angle measurement compliant with the Cesi standard (CESI0.03).

[0117] Hereinafter, some of the test results will be cited for reference to explain the present invention in more detail. For details of the test, please refer to Table 1.

[0118]

Table 1

[0119] According to Table 1, as can be seen from the comparison of Comparative Example 3, Comparative Example 4, and Comparative Example 5, only the first particles 2 with a uniform diameter, that is, only cylindrical particles, are provided in the light diffusion film 10. The contrast of this display panel is significantly lower than that of the display panel in which only the double-conical particles are provided in the light diffusion film 10 and the display panel in which only the long conical particles are provided in the light diffusion film 10. Its light transmittance is also slightly lower than the light transmittance of the display panel in which only the double-conical particles are provided in the light diffusion film 10 and the display panel in which only the long conical particles are provided in the light diffusion film 10.

[0120] According to Table 1, as can be seen from the comparison between Examples 1 to 5 and Comparative Example 1, the chromaticity viewing angle of the display panel with the light diffusion film 10 in which the first particles 2 and the second particles 3 are mixed in the resin layer 1 is higher than that of the display panel with the light diffusion film 10 in which only the second particles 3 are provided in the resin layer 1. The chromaticity viewing angle of the display panel with the light diffusion film 10 in which the first particles 2 and the second particles 3 are mixed in the resin layer 1 can reach 160 degrees or more. As can be seen from the comparison between Examples 1 to 5 and Comparative Example 2, the contrast and transmittance of the display panel with the light diffusion film 10 in which the first particles 2 and the second particles 3 are mixed in the resin layer 1 are higher than those of the display panel with the light diffusion film 10 in which only the first particles 2 are provided in the resin layer 1. The contrast of the display panel with the light diffusion film 10 in which the first particles 2 and the second particles 3 are mixed in the resin layer 1 can reach 2800 or more, and the transmittance can reach 4.65% or more. As can be seen from this, the light diffusion film 10 using the present application has excellent performance and has a more excellent application prospect.

[0121] The light diffusion film 10, polarizer 100 and liquid crystal display device 1000 provided in the examples of the present application have been introduced in detail above.

[0122] In the present application, by providing the first particles and the second particles in the resin layer of the light diffusion film, the light diffusion film has a scattering effect, and the contrast of the display panel to which the light diffusion film is attached is improved. Here, in the longitudinal direction of the first particles, the diameters of the first particles are the same. The second particle includes a first end and a second end along its longitudinal direction, and the diameter of the first end gradually decreases in the direction away from the second end. Both the first particles and the second particles can endow the light diffusion film with a scattering effect, and can improve the chromaticity viewing angle of the polarizer to which the light diffusion film is attached. And by mixing the second particles and the first particles, the influence on the contrast of the display panel to which the light diffusion film is attached is reduced, and the contrast of the display panel to which the light diffusion film is attached is improved.

[0123] In this specification, specific examples are used to explain the principles and embodiments of the present application, and the description of the above embodiments is only used to assist in understanding the method and core ideas of the present application. It should be pointed out that those skilled in the art can make several improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Description of Reference Numerals

[0124] 1000: Liquid crystal display device, 100: Polarizer, 200: Liquid crystal display panel, 10: Light diffusion film, 11: Release film, 12: First adhesive layer, 13: Optical compensation layer, 14: Polarization function layer, 15: First substrate, 16: Second adhesive layer, 17: Second substrate, 18: Hard coat layer, 19: Anti-reflection layer, 21: Protection layer, 1: Resin layer, 2: First particle, 3: Second particle, 3a: First type of particle, 3b: Second type of particle, D1: First end, D2: Second end, D3: Intermediate part.

Claims

1. A light diffusing film including a resin layer, and first particles and second particles provided in the resin layer, wherein in the longitudinal direction of the first particles, the diameters of the first particles are the same, and the second particles include a first end portion and a second end portion along its longitudinal direction, and the diameter of the first end portion gradually decreases in a direction away from the second end portion Light diffusing film.

2. The diameter of the second particles gradually decreases along the direction from the second end portion toward the first end portion of the second particles The light diffusing film according to Claim 1.

3. The diameter of the second end portion gradually decreases in a direction away from the first end portion The light diffusing film according to Claim 1.

4. The second particles further include an intermediate portion, and the first end portion, the intermediate portion, and the second end portion are connected in sequence, in the longitudinal direction of the second particles, the diameters of the intermediate portion are the same, and the diameter of the second end portion gradually decreases in a direction away from the first end portion The light diffusing film according to Claim 1.

5. The second particles further include an intermediate portion, and the first end portion, the intermediate portion, and the second end portion are connected in sequence, in the longitudinal direction of the second particles, the diameters of the intermediate portion are the same, and the diameters of the second end portion are the same The light diffusing film according to Claim 1.

6. The diameter of the first particles is 0.008 μm to 12.4 μm, the maximum diameter of the second particles is 12.4 μm, and the minimum diameter of the second particles is 0.008 μm The light diffusing film according to Claim 1.

7. The ratio of the mass of all the first particles to the mass of all the second particles is (1 to 10):(90 to 99) The light diffusing film according to Claim 1.

8. The total mass of the first particles and the second particles accounts for 10% of the mass of the light diffusing film, the second particles include first type particles and second type particles, and each of the first type particles and the second type particles includes a first end portion and a second end portion along its longitudinal direction, the diameter of the first type particles gradually decreases along the direction from the second end portion of the first type particles toward the first end portion of the first type particles, the diameter of the second end portion of the second type particles gradually decreases in a direction away from the first end portion of the second type particles, The ratio of the mass of all the first particles, the mass of all the first-type particles, and the mass of all the second-type particles is (1 to 10):(40 to 70):(20 to 60). The light diffusion film according to claim 1.

9. The total mass of the first particles and the second particles accounts for 10% of the mass of the light diffusion film. The second particles include first-type particles and second-type particles. Each of the first-type particles and the second-type particles includes a first end and a second end along its length direction. The diameter of the first-type particles gradually decreases along the direction from the second end of the first-type particles to the first end of the first-type particles. The second-type particles further include a middle part. The first end of the second-type particles, the middle part of the second-type particles, and the second end of the second-type particles are connected in sequence. In the length direction of the second-type particles, the diameter of the middle part of the second-type particles is the same, and the diameter of the second end of the second-type particles gradually decreases in the direction away from the first end of the second-type particles. The ratio of the mass of all the first particles, the mass of all the first-type particles, and the mass of all the second-type particles is (1 to 10):(40 to 70):(20 to 60). The light diffusion film according to claim 1.

10. The first particles are one or more inorganic particles among calcium carbonate particles, calcium sulfate particles, calcium chloride particles, calcium oxalate particles, magnesium chloride particles, magnesium carbonate particles, magnesium sulfate particles, barium carbonate particles, barium sulfate particles, barium chloride particles, titanium dioxide particles, and zinc oxide particles, or the first particles are one or more organic particles among polymethyl methacrylate particles, polystyrene particles, polycarbonate particles, silicone elastomer particles, butyl acrylate-styrene particles, and poly-4-hydroxybenzyl ester particles. The second particle is one or more inorganic particles among calcium carbonate particles, calcium sulfate particles, calcium chloride particles, calcium oxalate particles, magnesium chloride particles, magnesium carbonate particles, magnesium sulfate particles, barium carbonate particles, barium sulfate particles, barium chloride particles, titanium dioxide particles, and zinc oxide particles, or the second particle is one or more organic particles among polymethyl methacrylate particles, polystyrene particles, polycarbonate particles, silicone elastomer particles, butyl acrylate-styrene particles, and poly-4-hydroxybenzyl ester particles The light diffusion film according to claim 1.

11. A polarizer including a light diffusion film, the light diffusion film including a resin layer, and first particles and second particles provided in the resin layer, wherein in the longitudinal direction of the first particles, the diameters of the first particles are the same, and the second particles include a first end portion and a second end portion along its longitudinal direction, and the diameter of the first end portion gradually decreases in a direction away from the second end portion The polarizer further includes a base material, a polarizing functional layer, and a hard coat layer, the base material is provided between the polarizing functional layer and the hard coat layer, and the resin layer is any one of the base material, the polarizing functional layer, and the hard coat layer Polarizer.

12. The first particles and the second particles are arranged in an oriented manner within the resin layer, and the included angle between the longitudinal direction of the first particles and the absorption axis of the polarizing functional layer is -10° to 10°, and the included angle between the longitudinal direction of the second particles and the absorption axis of the polarizing functional layer is -10° to 10° The polarizer according to claim 9.

13. The diameter of the second particle gradually decreases along the direction from the second end portion toward the first end portion The polarizer according to claim 9.

14. The diameter of the second end portion gradually decreases in a direction away from the first end portion The polarizer according to claim 9.

15. The second particle further includes an intermediate portion, and the first end portion, the intermediate portion, and the second end portion are connected in sequence In the longitudinal direction of the second particle, the diameter of the intermediate portion is the same, and the diameter of the second end portion gradually decreases in a direction away from the first end portion The polarizer according to claim 9.

16. The second particle further includes an intermediate portion, and the first end portion, the intermediate portion, and the second end portion are connected in sequence. In the longitudinal direction of the second particle, the diameter of the intermediate portion is the same, and the diameter of the second end portion is the same. The polarizer according to claim 9.

17. The diameter of the first particle is from 0.008 microns to 12.4 microns, the maximum diameter of the second particle is 12.4 microns, and the minimum diameter of the second particle is 0.008 microns. The polarizer according to claim 9.

18. The ratio of the mass of all the first particles to the mass of all the second particles is (1 to 10):(90 to 99). The polarizer according to claim 9.

19. The total mass of the first particle and the second particle accounts for 10% of the mass of the light diffusion film. The second particle includes a first type of particle and a second type of particle. Each of the first type of particle and the second type of particle includes a first end portion and a second end portion along its longitudinal direction. The diameter of the first type of particle gradually decreases along the direction from the second end portion to the first end portion of the first type of particle. The diameter of the second end portion of the second type of particle gradually decreases in the direction away from the first end portion of the second type of particle. The ratio of the mass of all the first particles, the mass of all the first type of particles, and the mass of all the second type of particles is (1 to 10):(40 to 70):(20 to 60). The polarizer according to claim 9.

20. A liquid crystal display device including a polarizer and a liquid crystal display panel, wherein the polarizer is provided on the light-emitting side of the liquid crystal display panel. Here, the polarizer includes a light diffusion film. The light diffusion film includes a resin layer, and a first particle and a second particle provided in the resin layer. In the longitudinal direction of the first particle, the diameter of the first particle is the same. The second particle includes a first end portion and a second end portion along its longitudinal direction. The diameter of the first end portion gradually decreases in the direction away from the second end portion. The polarizer further includes a base material, a polarizing functional layer, and a hard coat layer. The base material is provided between the polarizing functional layer and the hard coat layer. The resin layer is any one of the base material, the polarizing functional layer, and the hard coat layer. Liquid crystal display device.

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