Light diffusion film, polarizer and display device

Abstract

An embodiment of the present invention discloses a light diffusion film, a polarizer, and a display device, wherein the light diffusion film comprises a substrate and light-diffusing particles dispersed in the substrate, the mass fraction of the light-diffusing particles in the substrate being less than 3%. By adding light-diffusing particles with a mass fraction of less than 3% to the substrate of the light diffusion film, the present invention can utilize the refractive effect of the light-diffusing particles on the light to improve the viewing angle of the polarizer, thereby avoiding the reduction in emitted light due to the addition of an additional film layer in the polarizer, and thus increasing the light output rate of the display device while improving the chromatic viewing angle and the contrast of the display device with the light diffusion film.

Description

TECHNICAL AREA

[0001] The present invention relates to the field of display, in particular a light diffusion film, a polarizer and a display device. STATE OF THE ART

[0002] Currently, to widen the chromatic viewing angle of a display device, an optical widening film is typically applied to the outermost side of a polarizer. Existing optical widening films require the addition of a corresponding film layer within the polarizer (e.g., the use of a patterned high-refractive-index layer overlaid with a low-refractive-index layer), which is a complex process and results in an increase in the thickness of the polarizer, a decrease in the light emitted by the display device, and a deterioration in the display contrast.

[0003] Therefore, there is a great need for a light diffusion film, a polarizer, and a display device to solve the aforementioned technical problems. DISCLOSURE OF THE INVENTION

[0004] The present invention provides a light diffusion film, a polarizer and a display device to alleviate the existing current technical problems of the deterioration of the display contrast of the display device due to the reduction of the light emitted by the display device by adding a film layer in the polarizer.

[0005] The present invention provides a light diffusion film comprising the following: a substrate; and light-diffusing particles dispersed in the substrate; where the mass fraction of the light-diffusing particles in the substrate is less than 3%.

[0006] Preferably, the light-diffusing particles comprise a first class of light-diffusing particles; wherein the first class of light-diffusing particles has several first cross-sections, one of the first cross-sections having a first circumcircle, and wherein the ratio of a length of the long axis of the first class of light-diffusing particles to a diameter of the first circumcircle with the largest diameter among the several first circumcircles is greater than or equal to 5, and wherein the ratio of a length of the long axis of the first class of light-diffusing particles to a diameter of the first circumcircle with the largest diameter among the several first circumcircles is less than 100, and wherein the first cross-section is oriented perpendicular to the extension direction of the long axis of the first class of light-diffusing particles.

[0007] Preferably, the first class of light-diffusing particles is at least one of a first subclass of light-diffusing particles, a second subclass of light-diffusing particles, a third subclass of light-diffusing particles, a fourth subclass of light-diffusing particles and a fifth subclass of light-diffusing particles with a different shape from each other; where, along the extension direction of the long axis of the first subclass of light-diffusing particles, a variation value of the diameter of a first circumcircle of the first cross-section of the first subclass of light-diffusing particles is less than or equal to 0.3 µm; and wherein, along the extension direction of the long axis of the second subclass of light-diffusing particles, a variation value of the diameter of a first circumcircle of the first cross-section located at the central part of the second subclass of light-diffusing particles is less than or equal to 1 µm, and wherein, along a direction away from the central part of the second subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the first end section of the second subclass of light-diffusing particles gradually decreases, and wherein a variation value of the diameter of a first circumcircle of the first cross-section located at the second end section of the second subclass of light-diffusing particles is less than or equal to 1 µm; and wherein, along the extension direction of the long axis of the third subclass of light-diffusing particles, a variation value of the diameter of a first circumcircle of the first cross-section located at the central part of the third subclass of light-diffusing particles is less than or equal to 1 µm, and wherein, along a direction away from the central part of the third subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the first end section of the third subclass of light-diffusing particles gradually decreases, and wherein the diameter of a first circumcircle of the first cross-section located at the second end section of the third subclass of light-diffusing particles gradually decreases; and wherein a first end section of the fourth subclass of light-diffusing particles is connected to a second end section of the fourth subclass of light-diffusing particles, and wherein along a direction extending from the first end section of the fourth subclass of light-diffusing particles to the second end section of the fourth subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section of the fourth subclass of light-diffusing particles gradually decreases; and wherein a first end section of the fifth subclass of light-diffusing particles is connected to a second end section of the fifth subclass of light-diffusing particles, and wherein along a direction away from the second end section of the fifth subclass of light-diffusing particles the diameter of a first circumcircle of the first cross-section located at the first end section of the fifth subclass of light-diffusing particles gradually decreases, and wherein along a direction away from the first end section of the fifth subclass of light-diffusing particles the diameter of a first circumcircle of the first cross-section located at the second end section of the fifth subclass of light-diffusing particles gradually decreases.

[0008] Preferably, the light-diffusing particles comprise a second class of light-diffusing particles; wherein the second class of light-diffusing particles has several second cross-sections, one of the second cross-sections having a second circumcircle, and wherein the ratio of a length of the long axis of the second class of light-diffusing particles to a diameter of the second circumcircle with the largest diameter among the several second circumcircles is greater than or equal to 1, and wherein the ratio of a length of the long axis of the second class of light-diffusing particles to a diameter of the second circumcircle with the largest diameter among the several second circumcircles is less than 5, and wherein the second cross-section is oriented perpendicular to the extension direction of the long axis of the second class of light-diffusing particles.

[0009] Preferably, the second class of light-diffusing particles is at least one of a sixth subclass of light-diffusing particles and a seventh subclass of light-diffusing particles with a different shape; wherein the second class of light-diffusing particles is at least one of a sixth subclass of light-diffusing particles, a seventh subclass of light-diffusing particles, an eighth subclass of light-diffusing particles, a ninth subclass of light-diffusing particles and a tenth subclass of light-diffusing particles, each with a different shape; where, along the extension direction of the long axis of the sixth subclass of light-diffusing particles, a variation value of the diameter of a second circumcircle of the second cross-section of the sixth subclass of light-diffusing particles is less than or equal to 0.3 µm; and wherein a first end section of the seventh subclass of light-diffusing particles is connected to a second end section of the seventh subclass of light-diffusing particles, and wherein along a direction away from the second end section of the seventh subclass of light-diffusing particles the diameter of a second circumcircle of the second cross-section located at the first end section of the seventh subclass of light-diffusing particles gradually decreases, and wherein along a direction away from the first end section of the seventh subclass of light-diffusing particles the diameter of a second circumcircle of the second cross-section located at the second end section of the seventh subclass of light-diffusing particles gradually decreases; and wherein, along the extension direction of the long axis of the eighth subclass of light-diffusing particles, a variation value of the diameter of a second circumcircle of the second cross-section located at the central part of the eighth subclass of light-diffusing particles is less than or equal to 1 µm, and wherein, along a direction away from the central part of the eighth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the eighth subclass of light-diffusing particles gradually decreases, and wherein a variation value of the diameter of a second circumcircle of the second cross-section located at the second end section of the eighth subclass of light-diffusing particles is less than or equal to 1 µm; and wherein, along the extension direction of the long axis of the ninth subclass of light-diffusing particles, a variation value of the diameter of a second circumcircle of the second cross-section located at the central part of the ninth subclass of light-diffusing particles is less than or equal to 1 µm, and wherein, along a direction away from the central part of the ninth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the ninth subclass of light-diffusing particles gradually decreases, and wherein the diameter of a second circumcircle of the second cross-section located at the second end section of the ninth subclass of light-diffusing particles gradually decreases; and wherein a first end section of the tenth subclass of light-diffusing particles is connected to a second end section of the tenth subclass of light-diffusing particles, and wherein along a direction extending from the first end section of the tenth subclass of light-diffusing particles to the second end section of the tenth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section of the tenth subclass of light-diffusing particles gradually decreases.

[0010] Preferably, the first subclass of light-diffusing particles is selected from rod-shaped particles, the second subclass of light-diffusing particles is selected from needle-like particles with a decreasing diameter at one end, the third subclass of light-diffusing particles is selected from needle-like particles with decreasing diameters at both ends, the fourth subclass of light-diffusing particles is selected from elongated conical particles, the fifth subclass of light-diffusing particles is selected from biconical and / or ellipsoidal particles, the sixth subclass of light-diffusing particles is selected from square-shaped or rectangular particles, and the seventh subclass of light-diffusing particles is selected from spherical or ellipsoidal particles.the eighth subclass of light-diffusing particles is selected from needle-like particles with a decreasing diameter at one end, the ninth subclass of light-diffusing particles is selected from needle-like particles with a decreasing diameter at both ends, and the tenth subclass of light-diffusing particles is selected from elongated conical particles.

[0011] Preferably, the mass fraction of the fifth subclass of light-diffusing particles in the light-diffusing particles is greater than or equal to 20%, wherein the mass fraction of the fifth subclass of light-diffusing particles in the light-diffusing particles is less than or equal to 100%.

[0012] Preferably, the light-diffusing particles have an average particle size, wherein the length of the long axis of any one of the light-diffusing particles is greater than or equal to 20% of the average particle size of the light-diffusing particles, and wherein the length of the long axis of any one of the light-diffusing particles is less than or equal to 180% of the average particle size of the light-diffusing particles.

[0013] Preferably, the substrate comprises a first sub-substrate and / or a second sub-substrate, wherein the first sub-substrate is at least one of unmodified polyester and unmodified cellulose acetate and the second sub-substrate is at least one of modified polyester and modified cellulose acetate; and wherein the mass fraction of the first sub-substrate in the substrate is greater than or equal to 65%, and wherein the mass fraction of the first sub-substrate in the substrate is less than or equal to 100%; and wherein the mass fraction of the second sub-substrate in the substrate is greater than or equal to 0%, and wherein the mass fraction of the second sub-substrate in the substrate is less than or equal to 35%.

[0014] The present invention further provides a polarizer comprising a light diffusion film as described above.

[0015] The present invention further provides a display device comprising a polarizer as described above.

[0016] By adding light-diffusing particles with a mass fraction of less than 3% to the substrate of the light diffusion film, the present invention can utilize the refractive effect of the light-diffusing particles on the light to improve the viewing angle of the polarizer, thereby avoiding the reduction of emitted light due to the addition of an additional film layer in the polarizer, and thus increasing the light output rate of the display device, while improving the chromatic viewing angle and the contrast of the display device with the light diffusion film. PRESENTATION OF THE INVENTION

[0017] To more clearly explain the technical solution in the embodiments of the present invention, the figures to be used are briefly introduced below in the explanation of the embodiments. Obviously, the figures described below only show some embodiments of the present invention. A person skilled in the art can derive other figures from these without any creative effort. Fig. Figure 1 shows a schematic diagram of a first structure of a light diffusion film in an embodiment of the present invention. Fig. Figure 2 shows a schematic diagram of a second structure of a light diffusion film in an embodiment of the present invention. Fig. Figure 3 shows a schematic diagram of a first structure of a polarizer in an embodiment of the present invention. Fig.Figure 4 shows a schematic diagram of a second structure of a polarizer in an embodiment of the present invention. Fig. Figure 5 shows a schematic diagram of a third structure of a polarizer in an embodiment of the present invention. Fig. Figure 6 shows a schematic diagram of a fourth structure of a polarizer in an embodiment of the present invention. Fig. Figure 7 shows a schematic diagram of the structure of a display device in an embodiment of the present invention. SPECIFIC EXECUTION FORMS

[0018] In connection with the figures in the embodiment of the present invention, the technical solutions in the embodiment of the present invention are explained clearly and completely below. Obviously, the embodiments described are not all embodiments, but merely a subset of embodiments of the present invention. All other embodiments that a person skilled in the art in this field could obtain from the embodiments in the present invention without any creative work should be considered to be within the scope of protection of the present invention. Furthermore, it is understood that the detailed embodiments described here serve only to illustrate the present invention, rather than to limit it.In the present invention, unless otherwise indicated, the use of orienting words such as "top" and "bottom" generally refers to the upper and lower parts of the device in its actual use or working state, in particular the surface direction in the accompanying drawings; while the words "inside" and "outside" refer to the outline of the device.

[0019] Currently, to widen the chromatic viewing angle, the optical film requires the addition of a corresponding film layer in the polarizer, which reduces the light emitted by the display device and degrades the display contrast, leading to the technical problem of a deterioration in the display quality of the display device.

[0020] Referring to Fig.Figures 1 to 2 provide an embodiment of the present invention comprising a light diffusion film 101 comprising a substrate 1011 and light-diffusing particles 1012, wherein the light-diffusing particles 1012 are dispersed in the substrate 1011; and wherein the mass fraction of the light-diffusing particles 1012 in the substrate 1011 is less than 3%.

[0021] By adding light-diffusing particles 1012 with a mass fraction of less than 3% to the substrate 1011 of the light diffusion film 101, the embodiment of the present invention can utilize the refractive effect of the light-diffusing particles 1012 on the light to improve the viewing angle of the polarizer, thereby avoiding the reduction of emitted light due to the addition of an additional film layer in the polarizer, and thus increasing the light output rate of the display device, while improving the chromatic viewing angle and the contrast of the display device with the light diffusion film 101.

[0022] Here, the technical solution of the present invention is explained in more detail in connection with specific embodiments.

[0023] Referring to Fig.In the present embodiment, the light-diffusing particles 1012 have a long axis and a diameter, wherein the length of the long axis of the light-diffusing particles 1012 is a distance between the two endpoints of the long axis of the light-diffusing particles 1012, and wherein each of the light-diffusing particles 1012 has several cross-sections perpendicular to the direction of extension of the long axis of the light-diffusing particles, each cross-section having a circumcircle, and wherein the diameter of the light-diffusing particles 1012 corresponds to the diameter of a circumcircle with the largest diameter among the first several cross-sections.In this case, two points in a cross-section of the light-diffusing particles 1012 that are furthest apart are located on the circumference of the cross-section, where the distance between two points in the cross-section that are furthest apart corresponds to the diameter of the circumference. The light-diffusing particles 1012 comprise a first class of light-diffusing particles 1012a.

[0024] The first class of light-diffusing particles 1012a has several first cross-sections, each of the first cross-sections having a first circumcircle, and wherein the ratio of a length of the long axis of the first class of light-diffusing particles 1012a to a diameter of the first circumcircle with the largest diameter among the several first circumcircles is greater than or equal to 5, and wherein the ratio of a length of the long axis of the first class of light-diffusing particles 1012a to a diameter of the first circumcircle with the largest diameter among the several first circumcircles is less than 100, and wherein the first cross-section is oriented perpendicular to the extension direction of the long axis of the first class of light-diffusing particles 1012a, and wherein the ratio is, for example, 10, 12, 15, 16, 18, 20, 30, 32, 34, 35, 36, 38, 40, 42, 45, 46, 48, 50, 52, 55, 56, 58, 60, 62, 65, 68, 70, 80, 90 and the like.The diameter of the first circumcircle of one of the first cross-sections of the first class of light-diffusing particles 1012a corresponds to the distance between two points in the first cross-section that are furthest apart. Using the first class of light-diffusing particles 1012a with a larger length-to-diameter ratio (ratio of the length of the long axis to the diameter of the first circumcircle with the largest diameter), it is easier for more light to change its direction of propagation through the light-diffusing particles 1012, thereby improving the chromatic viewing angle and contrast of the light-diffusing particles 1012.

[0025] In some embodiments, the first class of light-diffusing particles 1012a is at least one of a first subclass of light-diffusing particles, a second subclass of light-diffusing particles, a third subclass of light-diffusing particles, a fourth subclass of light-diffusing particles and a fifth subclass of light-diffusing particles, each with a different shape;

[0026] In this case, along the extension direction of the long axis of the first subclass of light-diffusing particles, a variation value of the diameter of a first circumcircle of the first cross-section of the first subclass of light-diffusing particles is less than or equal to 0.3 µm, e.g. it can be 0 µm, 0.28 µm, 0.25 µm, 0.22 µm, 0.2 µm, 0.18 µm, 0.15 µm, 0.12 µm, 0.1 µm, 0.08 µm, 0.05 µm, 0.02 µm and the like.In some embodiments, along the extension direction of the long axis of the first subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the first end section of the first subclass of light-diffusing particles is equal to the diameter of a first circumcircle of the first cross-section located at the middle part of the first subclass of light-diffusing particles, wherein the diameter of a first circumcircle located at the second end section of the first subclass of light-diffusing particles is equal to the diameter of a first circumcircle located at the middle part of the first subclass of light-diffusing particles.

[0027] In some embodiments, the first cross-sections of the first subclass of light-diffusing particles can have a regular shape such as a circle, an oval, a triangle, a square, or an irregular shape.

[0028] In some embodiments, the first subclass of light-diffusing particles can be rod-shaped particles. If the first subclass of light-diffusing particles is rod-shaped, the first cross-section of the first subclass of light-diffusing particles is circular or oval. If the first cross-section of the first subclass of light-diffusing particles is circular, the first circumcircle of the first cross-section of the first subclass of light-diffusing particles can coincide with the first cross-section.If the first cross-section of the first subclass of light-diffusing particles is oval, the diameter of the first circumcircle of each of the first cross-sections of the first subclass of light-diffusing particles corresponds to the length of the long axis of an oval represented by each of the first cross-sections of the first subclass of light-diffusing particles, wherein the ratio of the length of the long axis of an oval represented by one of the first cross-sections of the first subclass of light-diffusing particles to the length of the short axis of an oval represented by the first cross-section of the first subclass of light-diffusing particles is greater than 1 and less than or equal to 3, for example, it may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8 and the like.

[0029] Along the direction of extension of the long axis of the second subclass of light-diffusing particles, a variation value of the diameter of a first circumcircle of the first cross-section located at the central part of the second subclass of light-diffusing particles is less than or equal to 1 µm; for example, it can be 0 micrometers, 0.95 micrometers, 0.8 micrometers, 0.78 micrometers, 0.75 micrometers, 0.72 micrometers, 0.7 micrometers, 0.68 micrometers, 0.65 micrometers, 0.62 micrometers, 0.6 micrometers, 0.58 micrometers, 0.55 micrometers, 0.52 micrometers, 0.5 micrometers, 0.48 micrometers, 0.45 micrometers, 0.42 micrometers, 0.4 micrometers, 0.38 micrometers, 0.35 micrometers, 0.32 micrometers, 0.3 micrometers, 0.28 micron, 0.25 micron, 0.22 micron, 0.2 micron, 0.18 micron, 0.15 micron, 0.12 micron, 0.1 micron, 0.08 micron, 0.05 micron, 0,0.2 micrometers and the like. In this process, the diameter of a first circumcircle of the first cross-section located at the first end section of the second subclass of light-diffusing particles gradually decreases along a direction away from the central part of the second subclass of light-diffusing particles, where a variation value of the diameter of a second end section of the second subclass of light-diffusing particles is less than or equal to 1 µm, for example, it can be 0 micrometers, 0.95 micrometers, 0.8 micrometers, 0.78 micrometers, 0.75 micrometers, 0.72 micrometers, 0.7 micrometers, 0.68 micrometers, 0.65 micrometers, 0.62 micrometers, 0.6 micrometers, 0.58 micrometers, 0.55 micrometers, 0.52 micrometers, 0.5 micrometers, 0.48 micrometers, 0.45 micrometers, 0.42 micrometers, 0.4 micrometers, 0.38 micrometers, 0.35 micron, 0.32 micron, 0.3 micron, 0.28 micron, 0.25 micron, 0.22 micron, 0.2 micron, 0.18 micron, 0.15 micron, 0,The diameters may be 12 micrometers, 0.1 micrometers, 0.08 micrometers, 0.05 micrometers, 0.02 micrometers, and the like. In some embodiments, the diameter of a first circumcircle of the first cross-section located at the first end section of the second subclass of light-diffusing particles gradually decreases along a direction away from the central part of the second subclass of light-diffusing particles, wherein the diameter of a first circumcircle of the first cross-section located at the second end section of the second subclass of light-diffusing particles is equal to the diameter of a first circumcircle of the first cross-section located at the central part of the second subclass of light-diffusing particles.

[0030] It is understood that the fact that the diameter of a first circumcircle of the first cross-section located at the first end section of the second subclass of light-diffusing particles gradually decreases along a direction away from the central part of the second subclass of light-diffusing particles means that in a direction away from the central part of the second subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the first end section of the second subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to, the successive decrease of the diameter of a first circumcircle of the first cross-section located at the first end section of the second subclass of light-diffusing particles in a direction away from the central part of the second subclass of light-diffusing particles.

[0031] In some embodiments, the first cross-sections of the second subclass of light-diffusing particles can have a regular shape such as a circle, an oval, a triangle, a square, or an irregular shape.

[0032] In some embodiments, the second subclass of light-diffusing particles can be needle-like particles with a decreasing diameter at one end.

[0033] In some embodiments, if the second subclass of light-diffusing particles is needle-like particles with a decreasing diameter at one end, the first cross-section of the second subclass of light-diffusing particles may be circular or oval. If a first cross-section located at the second end section of the second subclass of light-diffusing particles or a first cross-section located at the middle section of the second subclass of light-diffusing particles is oval, the ratio of the long axis of any first cross-section located at the second end section or middle section of the second subclass of light-diffusing particles to the short axis of the oval is greater than 1 and less than or equal to 3, for example, it may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, and the like.The shape of the first cross-section located at the first end section of the second subclass of light-diffusing particles is the same as that of the first cross-section located at the middle section of the second subclass of light-diffusing particles, its area gradually decreasing along a direction away from the middle section of the second subclass of light-diffusing particles.

[0034] Along the direction of extension of the long axis of the third subclass of light-diffusing particles, a variation value of the diameter of a first circumcircle of the first cross-section located at the central part of the third subclass of light-diffusing particles is less than or equal to 1 µm, for example, it can be 0 micrometers, 0.95 micrometers, 0.8 micrometers, 0.78 micrometers, 0.75 micrometers, 0.72 micrometers, 0.7 micrometers, 0.68 micrometers, 0.65 micrometers, 0.62 micrometers, 0.6 micrometers, 0.58 micrometers, 0.55 micrometers, 0.52 micrometers, 0.5 micrometers, 0.48 micrometers, 0.45 micrometers, 0.42 micrometers, 0.4 micrometers, 0.38 micrometers, 0.35 micrometers, 0.32 micrometers, 0.3 micrometers, 0.28 micrometers, 0.25 micrometers, 0.22 micrometers, 0.2 micrometers, 0.18 micrometers, 0.15 micrometers, 0.12 micrometers, 0.1 micrometers, 0.08 micrometers, 0.05 micrometers, 0.02 micrometers and the like.Along a direction away from the central part of the third subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the first end section of the third subclass of light-diffusing particles gradually decreases, with the diameter of a first circumcircle of the first cross-section located at the second end section of the third subclass of light-diffusing particles gradually decreasing.In some embodiments, along the extension direction of the long axis of the third subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the central part of the third subclass of light-diffusing particles is uniform, with the diameters of the first circumcircles of the first cross-sections located at the first end section of the third subclass of light-diffusing particles and the second end section of the third subclass of light-diffusing particles changing gradually.

[0035] It is understood that the fact that the diameter of a first circumcircle of the first cross-section located at the first end section of the third subclass of light-diffusing particles gradually decreases along a direction away from the central part of the third subclass of light-diffusing particles means that in a direction away from the central part of the third subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the first end section of the third subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to, the successive decrease of the diameter of a first circumcircle of the first cross-section located at the first end section of the third subclass of light-diffusing particles in a direction away from the central part of the third subclass of light-diffusing particles.

[0036] It is understood that the fact that the diameter of a first circumcircle of the first cross-section located at the second end section of the third subclass of light-diffusing particles gradually decreases along a direction away from the central part of the third subclass of light-diffusing particles means that in a direction away from the central part of the third subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the second end section of the third subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to, the successive decrease of the diameter of a first circumcircle of the first cross-section located at the second end section of the third subclass of light-diffusing particles in a direction away from the central part of the third subclass of light-diffusing particles.

[0037] In some embodiments, the first cross-sections of the third subclass of light-diffusing particles can have a regular shape such as a circle, an oval, a triangle, a square, or an irregular shape.

[0038] In some embodiments, the third subclass of light-diffusing particles can be needle-like particles with a decreasing diameter at both ends.

[0039] In some embodiments, where the third subclass of light-diffusing particles can be needle-like particles with a decreasing diameter at both ends, the first cross-section of the third subclass of light-diffusing particles can be circular or oval. If a first cross-section located at the central part of the third subclass of light-diffusing particles is oval, the ratio of the long axis of any oval represented by a first cross-section located at the central part of the third subclass of light-diffusing particles to the short axis of the oval is greater than 1 and less than or equal to 3, for example, it can be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, and the like.The shape of the first cross-sections located at the first end section of the third subclass of light-diffusing particles and the second end section of the third subclass of light-diffusing particles is the same as that of the first cross-section located at the middle section of the third subclass of light-diffusing particles, its area gradually decreasing along a direction away from the middle section of the third subclass of light-diffusing particles.

[0040] A first end section of the fourth subclass of light-diffusing particles is connected to a second end section of the fourth subclass of light-diffusing particles, wherein along a direction extending from the first end section of the fourth subclass of light-diffusing particles to the second end section of the fourth subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section of the fourth subclass of light-diffusing particles gradually decreases.

[0041] It is understood that the fact that the diameter of a first circumcircle of the first cross-section of the fourth subclass of light-diffusing particles gradually decreases along a direction extending from the first end section of the fourth subclass of light-diffusing particles to the second end section of the fourth subclass of light-diffusing particles means that the diameter of a first circumcircle of the first cross-section of the fourth subclass of light-diffusing particles exhibits a decreasing tendency in a direction extending from the first end section of the fourth subclass of light-diffusing particles to the second end section of the fourth subclass of light-diffusing particles, which includes, but is not limited to,that in a direction extending from the first end section of the fourth subclass of light-diffusing particles to the second end section of the fourth subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section of the fourth subclass of light-diffusing particles decreases successively.

[0042] In some embodiments, the first cross-sections of the fourth subclass of light-diffusing particles can have a regular shape such as a circle, an oval, a triangle, a square, or an irregular shape.

[0043] In some embodiments, the fourth subclass of light-diffusing particles can be elongated conical particles.

[0044] In some embodiments, where the fourth subclass of light-diffusing particles consists of elongated conical particles, the first cross-section of the fourth subclass of light-diffusing particles is circular or oval. Along a direction extending from the first end section of the fourth subclass of light-diffusing particles to the second end section of the fourth subclass of light-diffusing particles, the first cross-sections of the fourth subclass of light-diffusing particles have the same shape, and their areas gradually decrease. If the first cross-section of the fourth subclass of light-diffusing particles is oval, the ratio of the long axis of any oval represented by any of the first cross-sections of the fourth subclass of light-diffusing particles to the short axis of the oval is greater than 1 and less than or equal to 3; for example, it may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, and the like.

[0045] A first end section of the fifth subclass of light-diffusing particles is connected to a second end section of the fifth subclass of light-diffusing particles, wherein along a direction away from the second end section of the fifth subclass of light-diffusing particles the diameter of a first circumcircle of the first cross-section located at the first end section of the fifth subclass of light-diffusing particles gradually decreases, and wherein along a direction away from the first end section of the fifth subclass of light-diffusing particles the diameter of a first circumcircle of the first cross-section located at the second end section of the fifth subclass of light-diffusing particles gradually decreases.

[0046] It is understood that the fact that the diameter of a first circumcircle of the first cross-section located at the first end section of the fifth subclass of light-diffusing particles gradually decreases along a direction away from the second end section of the fifth subclass of light-diffusing particles means that in a direction away from the second end section of the fifth subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the first end section of the fifth subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to, the fact that in a direction away from the second end section of the fifth subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the first end section of the fifth subclass of light-diffusing particles decreases successively.

[0047] It is understood that the fact that the diameter of a first circumcircle of the first cross-section located at the second end section of the fifth subclass of light-diffusing particles gradually decreases along a direction away from the first end section of the fifth subclass of light-diffusing particles means that in a direction away from the first end section of the fifth subclass of light-diffusing particles, the diameter of a first circumcircle of the first cross-section located at the second end section of the fifth subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to, the successive decrease of the diameter of a first circumcircle of the first cross-section located at the second end section of the fifth subclass of light-diffusing particles in a direction away from the first end section of the fifth subclass of light-diffusing particles.

[0048] In some embodiments, the first cross-sections of the fifth subclass of light-diffusing particles can have a regular shape such as a circle, an oval, a triangle, a square, or an irregular shape.

[0049] In some embodiments, the fifth subclass of light-diffusing particles can be biconical particles and / or ellipsoidal particles.

[0050] In some embodiments, where the fifth subclass of light-diffusing particles is biconical and / or ellipsoidal, the first cross-section of the fifth subclass of light-diffusing particles is circular or oval. Along a direction opposite the second end section of the fifth subclass of light-diffusing particles, the first cross-sections located at the first end section of the fifth subclass of light-diffusing particles have the same shape, and their areas gradually decrease; along a direction opposite the first end section of the fifth subclass of light-diffusing particles, the first cross-sections located at the second end section of the fifth subclass of light-diffusing particles have the same shape, and their areas gradually decrease.If the first cross-section of the fifth subclass of light-diffusing particles is oval, the ratio of the long axis of an oval represented by any of the first cross-sections of the fifth subclass of light-diffusing particles to the short axis of the oval is greater than 1 and less than or equal to 3, for example, it may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8 and the like.

[0051] The difference between the fifth subclass of light-diffusing particles, which are biconical particles and ellipsoidal particles, is that if the fifth subclass of light-diffusing particles are biconical particles, they have a cross-section of polygons, such as triangles, quadrilaterals, etc., in a direction parallel to the long axis of the fifth subclass of light-diffusing particles; and if the fifth subclass of light-diffusing particles are ellipsoidal particles, they have an oval cross-section in a direction parallel to the long axis of the fifth subclass of light-diffusing particles.

[0052] In some embodiments, the fifth subclass of light-diffusing particles, compared to the first, second, third, and fourth subclasses, can allow a greater number of light propagation directions, thereby improving the chromatic viewing angle and contrast. Therefore, the light-diffusing particles 1012a comprise at least a fifth subclass. Among the fifth subclass of light-diffusing particles, ellipsoidal particles change the direction of light propagation better than biconical particles, and preferably, the fifth subclass of light-diffusing particles comprises at least ellipsoidal particles.

[0053] In some embodiments, the first class of light-diffusing particles 1012a comprises a fifth subclass of light-diffusing particles, wherein the first subclass of light-diffusing particles further comprises at least one of a first subclass of light-diffusing particles, a second subclass of light-diffusing particles, a third subclass of light-diffusing particles and a fourth subclass of light-diffusing particles.Preferably, the first class of light-diffusing particles comprises at least a first subclass of light-diffusing particles, a second subclass of light-diffusing particles, a third subclass of light-diffusing particles, a fourth subclass of light-diffusing particles, and a fifth subclass of light-diffusing particles, which improves the diversity of shapes of the light-diffusing particles 1012 and the optical anisotropy of the light-diffusing particles 1012 and contributes to improving the enhancement effect of the light-diffusing particles 1012 on contrast and brightness.

[0054] In some embodiments, the length of the long axis of the first class of light-diffusing particles 1012a is greater than or equal to 4 µm, while in other embodiments the length of the long axis of the first class of light-diffusing particles 1012a is less than or equal to 30 µm, for example it can be 5 micrometers, 10 micrometers, 15 micrometers, 20 micrometers, 25 micrometers and the like, so that more light passes through the surface of the long axis of the first class of light-diffusing particles 1012a and changes the direction of propagation in order to improve the amplification effect of the light-diffusing particles 1012 on contrast and brightness.Preferably, the length of the long axis of the first class of light-diffusing particles 1012a is greater than or equal to 10 µm, wherein the length of the long axis of the first class of light-diffusing particles 1012a is less than or equal to 30 µm in order to obtain first light-diffusing particles 1012 that have an appropriate long axis length and are more concentrated, which contributes to further improving the enhancement effect of the light-diffusing particles 1012 on contrast and brightness.

[0055] In some embodiments, the light-diffusing particles 1012 can consist of the first class of light-diffusing particles 1012a.

[0056] In some embodiments, when improving the chromatic viewing angle and contrast of the light diffusion film 101, the improvement of the haze improvement effect of the light diffusion film 101 is taken into account, wherein the light diffusing particles 1012 further comprise a second class of light diffusing particles 1012b.

[0057] The second class of light-diffusing particles 1012b has several second cross-sections, each of which has a second circumcircle, and wherein the ratio of a length of the long axis of the second class of light-diffusing particles 1012b to a diameter of the second circumcircle with the largest diameter among the several second circumcircles is greater than or equal to 1, and wherein the ratio of a length of the long axis of the second class of light-diffusing particles 1012b to a diameter of the second circumcircle with the largest diameter among the several second circumcircles is less than 5, for example, it can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 3.5, 4, 4.5 and the like, and wherein the second cross-section is perpendicular to the direction of extension of the long axis of the second class of light-diffusing particles 1012b is aligned.Because the light-diffusing particles 1012 include a second class of light-diffusing particles 1012b with a smaller length-to-diameter ratio (ratio of the length of the long axis to the diameter of the second circumcircle with the largest diameter), it is beneficial for improving the chromatic viewing angle and contrast of the light diffusion film 101, while improving the haze-enhancing effect of the light diffusion film 101.

[0058] In some embodiments, the second class of light-diffusing particles 1012b is at least one of a sixth subclass of light-diffusing particles, a seventh subclass of light-diffusing particles, an eighth subclass of light-diffusing particles, a ninth subclass of light-diffusing particles and a tenth subclass of light-diffusing particles, each with a different shape.

[0059] Along the extension direction of the long axis of the sixth subclass of light-diffusing particles, a variation value of the diameter of a second circumcircle of the second cross-section of the sixth subclass of light-diffusing particles is less than or equal to 0.3 µm, e.g. it can be 0 µm, 0.28 µm, 0.25 µm, 0.22 µm, 0.2 µm, 0.18 µm, 0.15 µm, 0.12 µm, 0.1 µm, 0.08 µm, 0.05 µm, 0.02 µm and the like.In some embodiments, along the extension direction of the long axis of the sixth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the sixth subclass of light-diffusing particles is equal to the diameter of a second circumcircle of the second cross-section located at the middle part of the sixth subclass of light-diffusing particles, wherein the diameter of a second circumcircle of the second cross-section located at the second end section of the sixth subclass of light-diffusing particles is equal to the diameter of a second circumcircle of the second cross-section located at the middle part of the sixth subclass of light-diffusing particles.

[0060] In some embodiments, the second cross-sections of the sixth subclass of light-diffusing particles can have a regular shape such as a circle, an oval, a triangle, a square, or an irregular shape.

[0061] In some embodiments, the sixth subclass of light-diffusing particles is cube-like particles or rectangular particles, wherein the second cross-section of the sixth subclass of light-diffusing particles is a square or a rectangle, and wherein the diameter of the second circumcircle of each of the second cross-sections of the sixth subclass of light-diffusing particles is the length of the diagonal of the square or rectangle in which the second cross-section is represented.

[0062] The sixth subclass of light-diffusing particles is similar to the first subclass of light-diffusing particles; the difference lies in the fact that the ratio of the length of the long axis of the sixth subclass of light-diffusing particles to the diameter of the second circumcircle with the largest diameter among the several second circumcircles of the second cross-sections of the sixth subclass of light-diffusing particles is preferably close to 1; for example, it can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 3, and the like.

[0063] A first end section of the seventh subclass of light-diffusing particles is connected to a second end section of the seventh subclass of light-diffusing particles, and along a direction away from the second end section of the seventh subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the seventh subclass of light-diffusing particles gradually decreases, and wherein along a direction away from the first end section of the seventh subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the second end section of the seventh subclass of light-diffusing particles gradually decreases.

[0064] It is understood that the fact that, along a direction away from the second end section of the seventh subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the seventh subclass of light-diffusing particles gradually decreases, means that, in a direction away from the second end section of the seventh subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the seventh subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to,that in a direction away from the second end section of the seventh subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the seventh subclass of light-diffusing particles decreases successively.

[0065] It is understood that the fact that, along a direction away from the first end section of the seventh subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the second end section of the seventh subclass of light-diffusing particles gradually decreases, means that, in a direction away from the first end section of the seventh subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the second end section of the seventh subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to,that in a direction away from the first end section of the seventh subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the second end section of the seventh subclass of light-diffusing particles decreases successively.

[0066] In some embodiments, the second cross-sections of the seventh subclass of light-diffusing particles can have a regular shape such as a circle, an oval, a triangle, a square, or an irregular shape.

[0067] In some embodiments, the seventh subclass of light-diffusing particles is spherical or ellipsoidal, wherein the second cross-section of the seventh subclass of light-diffusing particles is circular or oval. If the second cross-section of the seventh subclass of light-diffusing particles is oval, the ratio of the long axis of any of the second cross-sections of the seventh subclass of light-diffusing particles to the short axis of the oval is greater than 1 and less than or equal to 3, for example, it may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, and the like.If the seventh subclass of light-diffusing particles is spherical particles, then any one of the second cross-sections of the seventh subclass of light-diffusing particles is circular, wherein the second circumcircle of any one of the second cross-sections coincides with the second cross-section, wherein the ratio of the long axis of the seventh subclass of light-diffusing particles to the diameter of the second circumcircle with the largest diameter among the several second circumcircles of the second cross-sections of the seventh subclass of light-diffusing particles is 1.

[0068] The seventh subclass of light-diffusing particles is similar to the fifth subclass of light-diffusing particles; the difference lies in the fact that the ratio of the length of the long axis of the seventh subclass of light-diffusing particles to the diameter of a second circumcircle with the largest diameter among the several second circumcircles of the seventh subclass of light-diffusing particles is smaller than the ratio of the length of the long axis of the fifth subclass of light-diffusing particles to the diameter of a first circumcircle with the largest diameter among the several first circumcircles of the fifth subclass of light-diffusing particles.If the seventh subclass of light-diffusing particles consists of ellipsoidal particles, their shape is preferably closer to that of spherical particles; that is, the closer the length of the long axis of the seventh subclass of light-diffusing particles is to the diameter of the seventh subclass of light-diffusing particles, the more preferred. Preferably, the ratio of the length of the long axis of the seventh subclass of light-diffusing particles to the diameter of a second circumcircle with the largest diameter among the several second circumcircles of the seventh subclass of light-diffusing particles is greater than or equal to 1, whereas the ratio of the length of the long axis of the seventh subclass of light-diffusing particles to the diameter of a second circumcircle with the largest diameter among the several second circumcircles of the seventh subclass of light-diffusing particles is less than or equal to 3.Further preferred is the ratio of the length of the long axis of the seventh subclass of light-diffusing particles to the diameter of a second circumcircle with the largest diameter among the several second circumcircles of the seventh subclass of light-diffusing particles greater than or equal to 1, wherein the ratio of the length of the long axis of the seventh subclass of light-diffusing particles to the diameter of a second circumcircle with the largest diameter among the several second circumcircles of the seventh subclass of light-diffusing particles is less than or equal to 1.5.

[0069] Along the direction of extension of the long axis of the eighth subclass of light-diffusing particles, a variation value of the diameter of a second circumcircle of the second cross-section located at the central part of the eighth subclass of light-diffusing particles is less than or equal to 1 µm, for example, it can be 0 micrometers, 0.95 micrometers, 0.8 micrometers, 0.78 micrometers, 0.75 micrometers, 0.72 micrometers, 0.7 micrometers, 0.68 micrometers, 0.65 micrometers, 0.62 micrometers, 0.6 micrometers, 0.58 micrometers, 0.55 micrometers, 0.52 micrometers, 0.5 micrometers, 0.48 micrometers, 0.45 micrometers, 0.42 micrometers, 0.4 micrometers, 0.38 micrometers, 0.35 micrometers, 0.32 micrometers, 0.3 micrometers, 0.28 micron, 0.25 micron, 0.22 micron, 0.2 micron, 0.18 micron, 0.15 micron, 0.12 micron, 0.1 micron, 0.08 micron, 0.05 micron, 0,0.2 micrometers and the like. Along a direction away from the central part of the eighth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the eighth subclass of light-diffusing particles gradually decreases, with a variation value of the diameter of a second end section of the eighth subclass of light-diffusing particles being less than or equal to 1 µm, for example, it can be 0 micrometers, 0.95 micrometers, 0.8 micrometers, 0.78 micrometers, 0.75 micrometers, 0.72 micrometers, 0.7 micrometers, 0.68 micrometers, 0.65 micrometers, 0.62 micrometers, 0.6 micrometers, 0.58 micrometers, 0.55 micrometers, 0.52 micrometers, 0.5 micrometers, 0.48 micrometers, 0.45 micrometers, 0.42 micrometers, 0.4 micrometers, 0.38 micrometers, 0.35 micron, 0.32 micron, 0.3 micron, 0.28 micron, 0.25 micron, 0.22 micron, 0.2 micron, 0.18 micron, 0.15 micron, 0,The diameters may be 12 micrometers, 0.1 micrometers, 0.08 micrometers, 0.05 micrometers, 0.02 micrometers, and the like. In some embodiments, the diameter of a second circumcircle of the second cross-section located at the first end section of the eighth subclass of light-diffusing particles gradually decreases along a direction away from the central part of the eighth subclass of light-diffusing particles, wherein the diameter of a second circumcircle of the second cross-section located at the second end section of the eighth subclass of light-diffusing particles is equal to the diameter of a second circumcircle of the second cross-section located at the central part of the eighth subclass of light-diffusing particles.

[0070] It is understood that the fact that the diameter of a second circumcircle of the second cross-section located at the first end section of the eighth subclass of light-diffusing particles gradually decreases along a direction away from the central part of the eighth subclass of light-diffusing particles means that in a direction away from the central part of the eighth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the eighth subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to, the successive decrease of the diameter of a second circumcircle of the second cross-section located at the first end section of the eighth subclass of light-diffusing particles in a direction away from the central part of the eighth subclass of light-diffusing particles.

[0071] In some embodiments, the second cross-sections of the eighth subclass of light-diffusing particles can have a regular shape such as a circle, an oval, a triangle, a square, or an irregular shape.

[0072] In some embodiments, the eighth subclass of light-diffusing particles can be needle-like particles with a decreasing diameter at one end.

[0073] In some embodiments, if the eighth subclass of light-diffusing particles is needle-like particles with a decreasing diameter at one end, the second cross-section of the eighth subclass of light-diffusing particles may be circular or oval. If a second cross-section located at the second end section of the eighth subclass of light-diffusing particles or a second cross-section located at the middle section of the eighth subclass of light-diffusing particles is oval, the ratio of the long axis of any oval located at the second end section or middle section of the eighth subclass of light-diffusing particles to the short axis of the oval is greater than 1 and less than or equal to 3, for example, it may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, and the like.The shape of the second cross-section located at the first end section of the eighth subclass of light-diffusing particles is the same as that of the second cross-section located at the middle section of the eighth subclass of light-diffusing particles, its area gradually decreasing along a direction away from the middle section of the eighth subclass of light-diffusing particles.

[0074] Along the direction of extension of the long axis of the ninth subclass of light-diffusing particles, a variation value of the diameter of a second circumcircle of the second cross-section located at the central part of the ninth subclass of light-diffusing particles is less than or equal to 1 µm, for example, it can be 0 micrometers, 0.95 micrometers, 0.8 micrometers, 0.78 micrometers, 0.75 micrometers, 0.72 micrometers, 0.7 micrometers, 0.68 micrometers, 0.65 micrometers, 0.62 micrometers, 0.6 micrometers, 0.58 micrometers, 0.55 micrometers, 0.52 micrometers, 0.5 micrometers, 0.48 micrometers, 0.45 micrometers, 0.42 micrometers, 0.4 micrometers, 0.38 micrometers, 0.35 micrometers, 0.32 micrometers, 0.3 micrometers, 0.28 micron, 0.25 micron, 0.22 micron, 0.2 micron, 0.18 micron, 0.15 micron, 0.12 micron, 0.1 micron, 0.08 micron, 0.05 micron, 0,0.2 micrometers and the like; along a direction away from the central part of the ninth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the ninth subclass of light-diffusing particles gradually decreases, wherein the diameter of a second circumcircle of the second cross-section located at the second end section of the ninth subclass of light-diffusing particles gradually decreases. In some embodiments, along the extension direction of the long axis of the ninth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the central part of the ninth subclass of light-diffusing particles is uniform,wherein the diameters of the second circumcircles of the second cross-sections located at the first end section of the ninth subclass of light-diffusing particles and the second end section of the ninth subclass of light-diffusing particles gradually change.

[0075] It is understood that the fact that the diameter of a second circumcircle of the second cross-section located at the first end section of the ninth subclass of light-diffusing particles gradually decreases along a direction away from the central part of the ninth subclass of light-diffusing particles means that in a direction away from the central part of the ninth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the first end section of the ninth subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to, the successive decrease of the diameter of a second circumcircle of the second cross-section located at the first end section of the ninth subclass of light-diffusing particles in a direction away from the central part of the ninth subclass of light-diffusing particles.

[0076] It is understood that the fact that the diameter of a second circumcircle of the second cross-section located at the second end section of the ninth subclass of light-diffusing particles gradually decreases along a direction away from the central part of the ninth subclass of light-diffusing particles means that in a direction away from the central part of the ninth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section located at the second end section of the ninth subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to, the successive decrease of the diameter of a second circumcircle of the second cross-section located at the second end section of the ninth subclass of light-diffusing particles in a direction away from the central part of the ninth subclass of light-diffusing particles.

[0077] In some embodiments, the second cross-sections of the ninth subclass of light-diffusing particles can have a regular shape such as a circle, an oval, a triangle, a square, or an irregular shape.

[0078] In some embodiments, the ninth subclass of light-diffusing particles can be needle-like particles with a decreasing diameter at both ends.

[0079] In some embodiments, where the ninth subclass of light-diffusing particles can be needle-like particles with a decreasing diameter at both ends, the second cross-section of the ninth subclass of light-diffusing particles can be circular or oval. If a second cross-section located at the central part of the ninth subclass of light-diffusing particles is oval, the ratio of the long axis of any oval represented by a second cross-section located at the central part of the ninth subclass of light-diffusing particles to the short axis of the oval is greater than 1 and less than or equal to 3, for example, it can be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, and the like.The shape of the second cross-sections located at the first end section of the ninth subclass of light-diffusing particles and the second end section of the ninth subclass of light-diffusing particles is the same as that of the second cross-section located at the middle section of the ninth subclass of light-diffusing particles, its area gradually decreasing along a direction away from the middle section of the ninth subclass of light-diffusing particles.

[0080] A first end section of the tenth subclass of light-diffusing particles is connected to a second end section of the tenth subclass of light-diffusing particles, wherein along a direction extending from the first end section of the tenth subclass of light-diffusing particles to the second end section of the tenth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section of the tenth subclass of light-diffusing particles gradually decreases.

[0081] It is understood that the fact that, along a direction extending from the first end section of the tenth subclass of light-diffusing particles to the second end section of the tenth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section of the tenth subclass of light-diffusing particles gradually decreases, means that, in a direction extending from the first end section of the tenth subclass of light-diffusing particles to the second end section of the tenth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section of the tenth subclass of light-diffusing particles exhibits a decreasing tendency, which includes, but is not limited to,that in a direction extending from the first end section of the tenth subclass of light-diffusing particles to the second end section of the tenth subclass of light-diffusing particles, the diameter of a second circumcircle of the second cross-section of the tenth subclass of light-diffusing particles decreases successively.

[0082] In some embodiments, the second cross-sections of the tenth subclass of light-diffusing particles can have a regular shape such as a circle, an oval, a triangle, a square, or an irregular shape.

[0083] In some embodiments, the tenth subclass of light-diffusing particles can be elongated conical particles.

[0084] In some embodiments, where the tenth subclass of light-diffusing particles consists of elongated conical particles, the second cross-section of the tenth subclass of light-diffusing particles is circular or oval. Along a direction extending from the first end section of the tenth subclass of light-diffusing particles to the second end section of the tenth subclass of light-diffusing particles, the second cross-sections of the tenth subclass of light-diffusing particles have the same shape, and their areas gradually decrease. If the second cross-section of the tenth subclass of light-diffusing particles is oval, the ratio of the long axis of any oval represented by the second cross-section of the tenth subclass of light-diffusing particles to the short axis of the oval is greater than 1 and less than or equal to 3; for example, it may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, and the like.

[0085] In some embodiments, the length of the long axis of the second class of light-diffusing particles 1012b is greater than or equal to 12 nm, while in others the length of the long axis of the second class of light-diffusing particles 1012b is less than or equal to 12.4 µm, for example it may be 20 nanometers, 50 nanometers, 100 nanometers, 500 nanometers, 1 micrometer, 3 micrometers, 5 micrometers, 8 micrometers, 10 micrometers and the like, to facilitate the light diffusion effect. Preferably, the length of the long axis of the second class of light-diffusing particles 1012b is greater than or equal to 1 µm, wherein the length of the long axis of the second class of light-diffusing particles 1012b is less than or equal to 5 µm. Further preferably, the length of the long axis of the second class of light-diffusing particles 1012b is greater than or equal to 1.5 µm, wherein the length of the long axis of the second class of light-diffusing particles is less than or equal to 4 µm.

[0086] Compared to the first class of light-diffusing particles 1012a, the improvement effect of the second class of light-diffusing particles 1012b on the chromatic viewing angle and contrast is relatively weak, and with a relatively small number of the second class of light-diffusing particles 1012b, a noticeable adjustment effect on the haze of the light-diffusing film 101 can be achieved. Therefore, the mass fraction of the second class of light-diffusing particles 1012b in the light-diffusing particles 1012 can be less than or equal to the mass fraction of the first class of light-diffusing particles 1012a in the light-diffusing particles 1012.For example, the mass fraction of the first class of light-diffusing particles 1012a in the light-diffusing particles 1012 is greater than or equal to 50%, while the mass fraction of the second class of light-diffusing particles 1012b in the light-diffusing particles 1012 is less than or equal to 50%. The mass fraction of the first class of light-diffusing particles 1012a in the light-diffusing particles 1012 can be 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, and so on.

[0087] In some embodiments, where the light-diffusing particles 1012 comprise the second class of light-diffusing particles 1012b and the second class of light-diffusing particles 1012b comprise the sixth subclass of light-diffusing particles and the seventh subclass of light-diffusing particles, the mass fraction of the sixth subclass of light-diffusing particles in the light-diffusing particles 1012 is smaller than the mass fraction of the seventh subclass of light-diffusing particles in the light-diffusing particles 1012.

[0088] In some embodiments, the first class of light-diffusing particles 1012a comprises at least the fifth subclass of light-diffusing particles, wherein the mass fraction of the fifth subclass of light-diffusing particles in the light-diffusing particles 1012 is greater than or equal to 20%, and wherein the mass fraction of the fifth subclass of light-diffusing particles in the light-diffusing particles 1012 is less than or equal to 100%. Preferably, the mass fraction of the fifth subclass of light-diffusing particles in the light-diffusing particles 1012 is greater than 55%, wherein the mass fraction of the fifth subclass of light-diffusing particles in the light-diffusing particles 1012 is less than or equal to 100%, for example, it may be 60%, 65%, 70%, 80%, 85%, 90%, 95%, and the like. The first class of light-diffusing particles 1012a further comprises a first subclass of light-diffusing particles,a second subclass of light-diffusing particles, a third subclass of light-diffusing particles, and a fourth subclass of light-diffusing particles, where the second subclass of light-diffusing particles 1012b further comprises the sixth subclass of light-diffusing particles and / or the seventh subclass of light-diffusing particles, the sum of the mass fractions of the first subclass of light-diffusing particles, the second subclass of light-diffusing particles, the third subclass of light-diffusing particles, the fourth subclass of light-diffusing particles, and the second subclass of light-diffusing particles 1012b in the light-diffusing particles 1012 is greater than or equal to 80% and less than 100%; preferably, the sum of the mass fractions of the first subclass of light-diffusing particles, the second subclass of light-diffusing particles,the third subclass of light-diffusing particles, the fourth subclass of light-diffusing particles, and the second class of light-diffusing particles 1012b in the light-diffusing particles 1012 greater than 0% and less than 45%, for example, it can be 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, and the like.

[0089] In some embodiments, the mass fraction of the light-diffusing particles 1012 in the light diffusion film 101 is less than 3%, for example, it can be 0.0001%, 0.001%, 0.01%, 0.02%, 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, etc., so that they can be dispersed uniformly in the light diffusion film 101. In this way, the present invention can utilize the refractive effect of the light-diffusing particles 1012 on the light to improve the viewing angle of the polarizer, avoiding the reduction of emitted light due to the addition of an additional film layer in the polarizer, and thus increasing the light output rate of the display device, while improving the chromatic viewing angle and the contrast of the display device with the light diffusion film 101.With a relatively small mass fraction of the light-diffusing particles 1012 in the light diffusion film 101, an effective improvement in contrast and chromatic viewing angle can be achieved. Preferably, the mass fraction of the light-diffusing particles 1012 in the light diffusion film 101 is greater than or equal to 0.001%, wherein the mass fraction of the light-diffusing particles 1012 in the light diffusion film 101 is less than 3%; more preferably, the mass fraction of the light-diffusing particles 1012 in the light diffusion film 101 is greater than or equal to 0.1%, wherein the mass fraction of the light-diffusing particles 1012 in the light diffusion film 101 is less than or equal to 1%. It is further preferred that the mass fraction of the light-diffusing particles 1012 in the light diffusion film 101 is greater than or equal to 0.1%, wherein the mass fraction of the light-diffusing particles 1012 in the light diffusion film 101 is less than or equal to 0.5%.

[0090] In some embodiments, the particle size distribution of the light-diffusing particles 1012 can be polydisperse or monodisperse. Preferably, the particle size distribution of the light-diffusing particles 1012 is monodisperse, which contributes to comprehensively enhancing the improvement effect of the light-diffusing particles 1012 on the optical properties of the optical film.If the particle size distribution of the light-diffusing particles 1012 is monodisperse, the light-diffusing particles 1012 have an average particle size, where the average particle size of the light-diffusing particles 1012 is the average value of the lengths of the long axes of the light-diffusing particles 1012, and if the light-diffusing particles 1012 have spherical particles and / or square-shaped particles, the particle size of the spherical particles is the diameter of the spherical particles, and the particle size of the square-shaped particles is the length of their sides.If the particle size distribution of the light-diffusing particles 1012 is monodisperse, the length of the long axis of any of the light-diffusing particles is greater than or equal to 20% of the average particle size of the light-diffusing particles, where the length of the long axis of any of the light-diffusing particles is less than or equal to 180% of the average particle size of the light-diffusing particles, i.e., 20% x the average particle size of the light-diffusing particles 1012 ≤ the length of the long axis of any of the light-diffusing particles 1012 ≤ 180% x the average particle size of the light-diffusing particles 1012.If the particle size distribution of the light-diffusing particles 1012 is monodisperse, the length of the long axis of any one of the light-diffusing particles is preferably greater than or equal to 50% of the average particle size of the light-diffusing particles, wherein the length of the long axis of any one of the light-diffusing particles is less than or equal to 150% of the average particle size of the light-diffusing particles, i.e., 50% x the average particle size of the light-diffusing particles 1012 ≤ the length of the long axis of any one of the light-diffusing particles 1012 ≤ 150% x the average particle size of the light-diffusing particles 1012.

[0091] In some embodiments, the second class of light-diffusing particles 1012b is a whisker. The material of the first class of light-diffusing particles 1012a and the material of the second class of light-diffusing particles 1012b are at least one of the following: organic materials, inorganic materials, and composite materials. For example, the material of the first class of light-diffusing particles 1012a and the material of the second class of light-diffusing particles 1012b can be at least one of the following: polysiloxane, polymethyl methacrylate, polystyrene, silicon dioxide, titanium dioxide, zirconium dioxide, silicon carbide, silicon nitride, zinc oxide, magnesium oxide, aluminum oxide, calcium sulfate, calcium carbonate, potassium titanate, or aluminum borate.

[0092] In some embodiments, the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a may be surface-modified to promote the dispersion of the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a in the substrate 1011 or to improve the functionality such as toughness, etc., of the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a. If the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a are surface-modified, the surface of the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a is modified by at least one of an inorganic cation, an inorganic anion, a polymer, a coupling agent or a surfactant, i.e.h. the surface of the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a comprises at least one of an inorganic cationic group, an inorganic anionic group, a polymer group, a coupling agent group or a surfactant group.

[0093] In particular, the surface of the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a is modified with at least one of magnesium chloride, calcium chloride, barium chloride, strontium chloride, stearic acid, sodium stearate, zinc octadecanoate, sulfonate surfactant, thiosurfactants, titanium esters, aluminate esters, polyacrylamides, silanes, alkyl phosphate esters, aryl phosphate esters, alkyl phosphates, aryl phosphates, alkyl alcoholamide esters, alkyl alcoholamide phosphates, imidazoline phosphate esters, imidazoline phosphate esters, homopolymer phosphate esters, homopolymer phosphate esters, and siloxane phosphate esters. Preferably, the surface of the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a is modified with at least one of a sulfonate surfactant or a thiosurfactant. The sulfonate surfactant can be at least one of an alkyl sulfonate and a fluorinated alkyl sulfonate.in particular at least one of sodium dodecylsulfonate, sodium dodecylbenzenesulfonate and fluorinated sodium dodecylsulfonate; and the thio-surfactant may be at least one of mercaptan and fluorinated mercaptan, in particular at least one of octanethiol, dodecanethiol, tetradecanethiol, octadecanethiol, fluorinated octanethiol and fluorinated dodecanethiol. After the sulfonate surfactant has been mixed with the light-diffusing particles 1012, which are to be surface-modified, the surface-active group of the sulfonic acid forms a sulfonic acid-based coating on the whisker surface, such as a benzene ring-sulfonic acid-based coating, etc., which serves to protect the light-diffusing particles 1012.contributes to improving the viscosity of the light-diffusing particles 1012 and to reducing the fracture of the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a in the light diffusion film 101. After the sulfonate surfactant is mixed with the light-diffusing particles 1012, which are to be surface-modified, the thio-based surface-active groups and the hydroxyl groups on the whisker surface form an OSO crosslinking network, and the binding energy of OSO is relatively high, which is conducive to protecting the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a in the process of mixing them with the substrate material 1011 and forming the light diffusion film 101.to reduce the rupture of the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a and to enhance the improvement effect of the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a on optical functions such as contrast and brightness. Preferably, the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a comprises at least one fluorine-substituted sulfonate surfactant and one fluorine-substituted thio surfactant, in particular, for example, at least one of sodium fluorododecylsulfonate, fluorooctanethiol, and fluorododecanethiol, wherein the fluorine atoms exhibit high stability in the alkyl chain and the bond energy of carbon-fluorine bonds is higher than the bond energy of carbon-carbon bonds.and wherein the fluorine atoms have a shielding effect on the carbon-carbon bond, which contributes to the protection of the carbon-carbon bond, thereby improving the stability of the second class of light-diffusing particles 1012b and / or the first class of light-diffusing particles 1012a.

[0094] In some embodiments, the substrate 1011 is at least one of modified or modified polyester, modified or unmodified cellulose acetate.

[0095] In some embodiments, the modified or unmodified polyester may comprise at least one of the following: modified or unmodified polyethylene terephthalate, modified or unmodified polycarbonate, modified or unmodified polymethyl methacrylate, or modified or unmodified polyethylene naphthalate. The modified or unmodified cellulose acetate may comprise modified or unmodified cellulose triacetate.

[0096] In some embodiments, the substrate 1011 can comprise a first sub-substrate and / or a second sub-substrate, wherein the first sub-substrate can be at least one of unmodified polyester and unmodified cellulose acetate. The second sub-substrate can be at least one of modified polyester and modified cellulose acetate. A mass fraction of the first sub-substrate in the substrate 1011 is greater than a mass fraction of the second sub-substrate.

[0097] In some embodiments, the first sub-substrate and the second sub-substrate are homogeneously mixed, and the first sub-substrate has a mass fraction in substrate 1011 that is greater than or equal to 65%, e.g., it can be 70%, 75%, 80%, 85%, 90%, 95%, 99%, and so on. The second sub-substrate has a mass fraction of less than or equal to 35% within substrate 1011, e.g., it can be 1%, 5%, 10%, 15%, 20%, 25%, 30%, etc.This is beneficial for the modified polyester, such as polyethylene terephthalate, and the unmodified polyester, such as polyethylene terephthalate, to be readily soluble with each other, or for the unmodified cellulose acetate, such as cellulose triacetate, and the unmodified cellulose acetate, such as cellulose triacetate, to be readily soluble with each other, which contributes to improving the mechanical properties, flatness, and crystalline properties of the substrate 1011 and to improving the dispersibility of the light-diffusing particles 1012, thereby improving the optical properties of the light diffusion film 101.

[0098] In some embodiments, the modified cellulose triacetate, the modified polyethylene terephthalate, the modified polycarbonate, the modified polymethacrylate, or the modified polyethylene naphthalene dicarboxylate can each be obtained by subjecting the unmodified cellulose triacetate, the unmodified polyethylene terephthalate, the unmodified polycarbonate, the unmodified polymethacrylate, or the unmodified polyethylene naphthalene dicarboxylate to a hydrophilic modification or a lipophilic modification.The modified polyethylene terephthalate can be obtained, for example, by introducing straight-chain alkyl side chains, carboxyl side chains, hydroxyl side chains, or side chains containing fluorine groups into the unmodified polyethylene terephthalate; if the modified polyethylene terephthalate can be obtained by introducing carboxyl side chains and / or hydroxyl side chains into the unmodified polyethylene terephthalate, the modified polyethylene terephthalate can be obtained by introducing groups into the phenyl group of the unmodified polyethylene terephthalate, where n and m are integers greater than or equal to 0 and less than or equal to 10.

[0099] In some embodiments, when the first sub-substrate is selected from unmodified polyethylene terephthalate, the second sub-substrate is selected from modified polyethylene terephthalate, and the mass fraction of the second sub-substrate in the substrate 1011 is less than or equal to 35%, which contributes to good mutual solubility of the modified polyethylene terephthalate and the unmodified polyethylene terephthalate, which improves the mechanical properties, flatness and crystalline properties of the substrate 1011 and improves the dispersibility of the light-diffusing particles 1012, thereby improving the optical properties of the light diffusion film 101.

[0100] In some embodiments, the difference between the refractive indices of the substrate 1011 and the light-diffusing particles 1012 is greater than or equal to 0.02, e.g., 0.03, 0.05, 0.09, 0.1, 0.15, 0.2, and the like, in order to achieve the light diffusion function of the light-diffusing particles 1012. Preferably, the difference between the refractive indices of the substrate 1011 and the light-diffusing particles 1012 is greater than or equal to 0.1, e.g., 0.12, 0.13, 0.14, 0.15, 0.2, and the like.

[0101] In some embodiments, within the same light diffusion film 101, the material of the first class of light diffusion particles 1012a and the material of the second class of light diffusion particles 1012b can be the same or different, and thus the difference between the refractive indices of the first class of light diffusion particles 1012a and the substrate 1011 can be the same as the difference between the refractive indices of the second class of light diffusion particles 1012b and the substrate 1011 or different.

[0102] In some embodiments, the refractive index of the first class of light-diffusing particles 1012a is greater than the refractive index of the substrate 1011. The refractive index of the first class of light-diffusing particles 1012b is greater than the refractive index of the substrate 1011. The refractive index of the second class of light-diffusing particles 1012b is greater than the refractive index of the first class of light-diffusing particles 1012a.

[0103] In some embodiments, the substrate 1011 has a glass transition temperature of 70°C to 600°C, which may be, for example, 80°C, 90°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, 550°C and the like.

[0104] In some embodiments, the substrate 1011 has a modulus of elasticity in the range of 500 MPa to 5000 MPa at 23°C, which may be, for example, 600 MPa, 700 MPa, 800 MPa, 900 MPa, 1000 MPa, 1200 MPa, 1500 MPa, 1800 MPa, 2000 MPa, 2200 MPa, 2500 MPa, 2800 MPa, 3000 MPa, 3200 MPa, 3500 MPa, 3800 MPa, 4000 MPa, 4200 MPa, 4500 MPa, 4800 MPa, and the like.

[0105] In some embodiments, the elastic modulus of substrate 1011 can be maintained at a moisture content of 50%.

[0106] In some embodiments, the thickness of the light diffusion film 101 is greater than or equal to 5 micrometers and the thickness of the light diffusion film 101 is less than or equal to 500 micrometers, and it can be, for example, 10 micrometers, 50 micrometers, 60 micrometers, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 450 micrometers and the like, in order to facilitate the processing and manufacture of the light diffusion film 101 and to maintain a suitable light transmittance of the light diffusion film 101. Preferably the thickness of the light diffusion film 101 is greater than or equal to 15 micrometers and the thickness of the light diffusion film 101 is less than or equal to 150 micrometers, and it can be, for example, 20 micrometers, 25 micrometers, 30 micrometers, 40 micrometers, 50 micrometers, 60 micrometers, 80 micrometers, 100 micrometers, 120 micrometers, 130 micrometers, 140 micrometers and the like.

[0107] In the light diffusion film 101 provided by the embodiment of the present invention, the refractive effect of the light diffusion particles 1012 on the light can be used to improve the viewing angle of the polarizer by adding light diffusion particles 1012 with a mass fraction of less than 3% to the substrate 1011 of the light diffusion film 101, thereby avoiding the reduction of the emitted light due to the addition of an additional film layer in the polarizer, and thus increasing the light output rate of the display device, while improving the chromatic viewing angle and the contrast of the display device with the light diffusion film 101.

[0108] Referring to Fig. 3 to 6, the embodiment of the present invention further provides a polarizer 100 comprising a light diffusion film 101 as described above.

[0109] The polarizer 100 further comprises a polarizing layer 102, which is arranged on one side of the light diffusion film 101.

[0110] Referring to Fig. 3 to 6, in some embodiments the polarizer100 further comprises a second optical functional layer 103 which is arranged on at least one side of the substrate 1011.

[0111] The second optical functional layer 103 is located between the polarizing layer 102 and the light diffusion film 101; or the second optical functional layer 103 is located on the side of the light diffusion film 101 facing away from the polarizing layer 102.

[0112] In some embodiments, the second optical functional layer 103 is arranged on a side of the light diffusion film 101 facing away from the polarizing layer 102, and the polarizer 100 further comprises a first adhesive layer 104 located on a side of the light diffusion film 101 facing the polarizing layer 102.

[0113] The first adhesive layer 104 is in direct contact with the polarizing layer 102; or the polarizer 100 further comprises a protective layer 105 located between the light diffusion film 101 and the polarizing layer 102, wherein the first adhesive layer 104 is in direct contact with the protective layer 105.

[0114] In some embodiments, the first adhesive layer 104 is in direct contact with the light diffusion film 101, wherein the first adhesive layer 104 is in direct contact with the polarizing layer 102; or the first adhesive layer 104 is in direct contact with the light diffusion film 101, wherein the first adhesive layer 104 is in direct contact with the protective layer 105.

[0115] In some embodiments, the first adhesive layer 104 can be at least one of a waterborne adhesive, a pressure-sensitive adhesive and a UV adhesive, wherein the material of the waterborne adhesive can be selected from polyvinyl alcohol, the material of the pressure-sensitive adhesive from acrylate copolymer and the material of the UV adhesive from multifunctional acrylate monomer.

[0116] Referring to Fig.In some embodiments, the second optical functional layer 103 comprises at least one of the following layers: a transparent hardened sublayer 107, a low-reflection sublayer 108, an anti-reflection sublayer, an anti-fingerprint sublayer, and an anti-static sublayer. If the second optical functional layer 103 is a low-reflection sublayer 108, the low-reflection sublayer 108 can be formed by stacking a transparent hardened sublayer 108a and a low-refractive-index sublayer 108b.

[0117] In some embodiments, the polarizing layer comprises 102 polyvinyl alcohol and a dye.

[0118] In some embodiments, the polarizer 100 further comprises a release layer 109 located on a side of the polarizing layer 102 facing away from the light diffusion film 101, the release layer 109 being bonded to the polarizing layer 102 by a second adhesive layer 110. When the polarizer 100 is applied to the display device, the release layer 109 is removed to expose the second adhesive layer 110, so that the polarizer 100 is bonded to the display panel by the second adhesive layer 110.

[0119] In some embodiments, the polarizer 100 further comprises a compensating layer 111, which is arranged between the second adhesive layer 110 and the polarizing layer 102.

[0120] By providing the light diffusion film 101, the embodiment of the present invention improves the chromatic viewing angle and the contrast of the display device with the polarizer 100, while avoiding the polarizer 100 causing optical defects such as moiré patterns or white spots.

[0121] Referring to Fig. Figure 7 further provides an embodiment of the present invention comprising a display device 10, comprising a polarizer 100 as described above.

[0122] In particular, the display device comprises a display panel 200 and a first polarizer 300, wherein the first polarizer 300 is located on a light-emitting side of the display panel 200, and wherein the first polarizer 300 is selected from the polarizer 100 above.

[0123] In some embodiments, the display panel 200 can be a liquid crystal display panel, a self-illuminating display panel, and the like, and the self-illuminating display panel can be an OLED (Organic Light-Emitting Diode) display panel, and the like.

[0124] In some embodiments, the light diffusion film 101 is located in the first polarizer 300 on a side of the polarizing layer 102 in the first polarizer 300 facing away from the display panel.

[0125] If the display panel 200 is a liquid crystal display panel, the display device 10 further comprises a backlight module 400 located on a side of the display panel 200 facing away from the first polarizer 300, which is used to provide the light source for the display panel 200; the display device 10 further comprises a second polarizer 500 located between the backlight module 400 and the display panel 200. The second polarizer 500 may be selected from the polarizer 100 above, or the second polarizer 500 may not be selected from the polarizer 100 above.

[0126] The present invention is described in more detail below with reference to some exemplary embodiments. It should be noted, however, that these examples serve only for illustration and should not be construed as limiting the present invention in any way. Example 1

[0127] The substrate material in the present embodiment is unmodified polyethylene terephthalate, and the light-diffusing particles within the substrate are spherical silicon dioxide and rod-shaped silicon dioxide mixed in a mass ratio of 1:1 to form a light diffusion film 1, and the mass fraction of the light-diffusing particles within the light diffusion film 1 is 0.1%. Example 2

[0128] The present embodiment is the same or similar to the first embodiment, the difference being that the light-diffusing particles within the substrate are ellipsoidal silicon dioxide and rod-shaped silicon dioxide mixed in a mass ratio of 1:1 to form a light diffusion film 2, and the mass fraction of the light-diffusing particles within the light diffusion film 2 is 0.5%. Comparative example 1

[0129] The comparative example is similar to embodiment 2, and the difference is that the light-diffusing particles in the comparative light diffusion film 1 formed have a mass fraction of 5%.

[0130] The light diffusion films obtained in embodiments 1 and 2 and the comparative light diffusion film obtained in comparative example 1 are arranged on a side of the polarizer facing away from the display panel, and the polarizer is attached to the surface of a 75-inch liquid crystal display panel for testing the optical effect, and the results are shown in the table. The polarizer to be tested comprises a compensation layer, a polarizing layer, a protective layer, a light diffusion film (or a contrast light diffusion film), and a transparent, hardened sublayer, arranged in a sequential stack.

[0131] It should be noted that the turbidity is determined by measurement with the NDH7000 turbidity meter.

[0132] The darkness ratio is the ratio of the brightness of the display panel, observed when the display panel is in a dark display state at an angle of 30° or 60° to the center of the display panel, to the brightness of the center of the display panel in the dark display state of the display panel.

[0133] Contrast is the ratio between the brightness of the display panel in its white state and its brightness in its dark state. This test measures the brightness of the center of the display panel in its white state and the brightness of the center of the display panel in its dark state.

[0134] The brightness viewing angle is the value of the lateral viewing angle when the brightness of the lateral viewing angle is half the brightness of the front viewing angle.

[0135] The transmittance is the ratio between the brightness in the white state and the light brightness of the backlight module.

[0136] The measurement of the chromatic viewing angle is the measurement of the viewing angle according to the CESI standard (CESI0.03). Table 1 Chromatic viewing angles ° contrast Permeability % Darkness ratio Brightness viewing angle ° Turbidity % 30° 60° Light diffusion film 1 134 5335,22 5,01 3,39 3,79 75 23,03 Light diffusion film 2 >160 4570 4,43 3,47 4,25 74 66,16 Comparative Light Diffusion Film 1 >160 2066 2,98 1,6 1,7 75 95

[0137] As can be seen from Table 1, the light-diffusing particles formed by mixing particles of different shapes with a mass fraction of less than 3% within the light diffusion film can achieve a larger chromatic viewing angle, and compared to the comparison light diffusion film 1 with a mass fraction of light-diffusing particles of more than 3% within the light diffusion film, the contrast and light transmission are significantly improved.

[0138] An embodiment of the present invention discloses a light diffusion film, a polarizer, and a display device, wherein the light diffusion film comprises a substrate and light-diffusing particles dispersed in the substrate, and wherein the mass fraction of the light-diffusing particles in the substrate is less than 3%. By adding light-diffusing particles with a mass fraction of less than 3% to the substrate of the light diffusion film, the present invention can utilize the refractive effect of the light-diffusing particles on the light to improve the viewing angle of the polarizer, thereby avoiding the reduction in emitted light due to the addition of an additional film layer in the polarizer, and thus increasing the light output rate of the display device while improving the chromatic viewing angle and the contrast of the display device with the light diffusion film.

[0139] Above, a light diffusion film, a polarizer, and a display device provided by the embodiments of the present invention are explained in more detail. The description explains the principle and embodiments of the present invention with specific examples, and the explanation of the above embodiments serves only to aid understanding of the method of the present invention and its core idea. According to the intent of the present invention, a person skilled in the art in this field would make a modification regarding the detailed embodiment and the scope of application. In summary, the content of this description should not be understood as limiting the present invention.

Claims

[1] Light diffusion film, characterized by that it includes: a substrate; and light-diffusing particles dispersed in the substrate; where the mass fraction of light-diffusing particles in the substrate is less than 3%. [2] Light diffusion film according to claim 1, characterized byin that the light-diffusing particles comprise a first class of light-diffusing particles; wherein the first class of light-diffusing particles has a plurality of first cross sections, each of the first cross sections having a first circumference, and wherein the ratio of a length of the long axis of the first class of light-diffusing particles to a diameter of the first circumference having the largest diameter among the plurality of first circumferences is greater than or equal to 5, and wherein the ratio of a length of the long axis of the first class of light-diffusing particles to a diameter of the first circumference having the largest diameter among the plurality of first circumferences is less than 100, and wherein the first cross section is oriented perpendicular to the extension direction of the long axis of the first class of light-diffusing particles. [3] Light diffusion film according to claim 2, characterized bythat the first class of light-diffusing particles is at least one of a first subclass of light-diffusing particles, a second subclass of light-diffusing particles, a third subclass of light-diffusing particles, a fourth subclass of light-diffusing particles, and a fifth subclass of light-diffusing particles having a different shape from one another; wherein, along the extension direction of the long axis of the first subclass of light-diffusing particles, a variation value of the diameter of a first circumcircle of the first cross section of the first subclass of light-diffusing particles is less than or equal to 0.3 µm; and wherein, along the extension direction of the long axis of the second subclass of light-diffusing particles, a variation value of the diameter of a first circumscribed circle of the first cross section located at the central part of the second subclass of light-diffusing particles is less than or equal to 1 µm, and wherein, along a direction facing away from the central part of the second subclass of light-diffusing particles, the diameter of a first circumscribed circle of the first cross section located at the first end portion of the second subclass of light-diffusing particles gradually decreases, and wherein a variation value of the diameter of a first circumscribed circle of the first cross section located at the second end portion of the second subclass of light-diffusing particles is less than or equal to 1 µm; and wherein, along the extension direction of the long axis of the third subclass of light-diffusing particles, a variation value of the diameter of a first circumscribed circle of the first cross section located at the central part of the third subclass of light-diffusing particles is less than or equal to 1 µm, and wherein, along a direction facing away from the central part of the third subclass of light-diffusing particles, the diameter of a first circumscribed circle of the first cross section located at the first end portion of the third subclass of light-diffusing particles gradually decreases, and wherein the diameter of a first circumscribed circle of the first cross section located at the second end portion of the third subclass of light-diffusing particles gradually decreases; and wherein a first end portion of the fourth subclass of light-diffusing particles is connected to a second end portion of the fourth subclass of light-diffusing particles, and wherein the diameter of a first circumcircle of the first cross section of the fourth subclass of light-diffusing particles gradually decreases along a direction extending from the first end portion of the fourth subclass of light-diffusing particles to the second end portion of the fourth subclass of light-diffusing particles; and wherein a first end portion of the fifth subclass of light-diffusing particles is connected to a second end portion of the fifth subclass of light-diffusing particles, and wherein the diameter of a first circumscribed circle of the first cross section located at the first end portion of the fifth subclass of light-diffusing particles gradually decreases along a direction remote from the second end portion of the fifth subclass of light-diffusing particles, and wherein the diameter of a first circumscribed circle of the first cross section located at the second end portion of the fifth subclass of light-diffusing particles gradually decreases along a direction remote from the first end portion of the fifth subclass of light-diffusing particles. [4] Light diffusion film according to claim 3, characterized byin that the light-diffusing particles comprise a second class of light-diffusing particles; wherein the second class of light-diffusing particles has a plurality of second cross sections, each of the second cross sections having a second circumference, and wherein the ratio of a length of the long axis of the second class of light-diffusing particles to a diameter of the second circumference having the largest diameter among the plurality of second circumferences is greater than or equal to 1, and wherein the ratio of a length of the long axis of the second class of light-diffusing particles to a diameter of the second circumference having the largest diameter among the plurality of second circumferences is less than 5, and wherein the second cross section is oriented perpendicular to the extension direction of the long axis of the second class of light-diffusing particles. [5] Light diffusion film according to claim 4, characterized bythat the second class of light-diffusing particles is at least one of a sixth subclass of light-diffusing particles, a seventh subclass of light-diffusing particles, an eighth subclass of light-diffusing particles, a ninth subclass of light-diffusing particles and a tenth subclass of light-diffusing particles having a different shape from one another; wherein, along the extension direction of the long axis of the sixth subclass of light-diffusing particles, a variation value of the diameter of a second circumcircle of the second cross section of the sixth subclass of light-diffusing particles is less than or equal to 0.3 µm; and wherein a first end portion of the seventh subclass of light-diffusing particles is connected to a second end portion of the seventh subclass of light-diffusing particles, and wherein the diameter of a second circumscribed circle of the second cross-section located at the first end portion of the seventh subclass of light-diffusing particles gradually decreases along a direction facing away from the second end portion of the seventh subclass of light-diffusing particles, and wherein the diameter of a second circumscribed circle of the second cross-section located at the second end portion of the seventh subclass of light-diffusing particles gradually decreases along a direction facing away from the first end portion of the seventh subclass of light-diffusing particles; and wherein, along the extension direction of the long axis of the eighth subclass of light-diffusing particles, a variation value of the diameter of a second circumscribed circle of the second cross section located at the central part of the eighth subclass of light-diffusing particles is less than or equal to 1 µm, and wherein, along a direction facing away from the central part of the eighth subclass of light-diffusing particles, the diameter of a second circumscribed circle of the second cross section located at the first end portion of the eighth subclass of light-diffusing particles gradually decreases, and wherein a variation value of the diameter of a second circumscribed circle of the second cross section located at the second end portion of the eighth subclass of light-diffusing particles is less than or equal to 1 µm; and wherein, along the extension direction of the long axis of the ninth subclass of light-diffusing particles, a variation value of the diameter of a second circumscribed circle of the second cross section located at the central part of the ninth subclass of light-diffusing particles is less than or equal to 1 µm, and wherein, along a direction facing away from the central part of the ninth subclass of light-diffusing particles, the diameter of a second outer-connecting circle of the second cross section located at the first end portion of the ninth subclass of light-diffusing particles gradually decreases, and wherein the diameter of a second circumscribed circle of the second cross section located at the second end portion of the ninth subclass of light-diffusing particles gradually decreases; and wherein a first end portion of the tenth subclass of light-diffusing particles is connected to a second end portion of the tenth subclass of light-diffusing particles, and wherein the diameter of a second circumcircle of the second cross section of the tenth subclass of light-diffusing particles gradually decreases along a direction extending from the first end portion of the tenth subclass of light-diffusing particles to the second end portion of the tenth subclass of light-diffusing particles. [6] Light diffusion film according to claim 5, characterized bythat the first subclass of light-diffusing particles is selected from rod-shaped particles, the second subclass of light-diffusing particles is selected from needle-like particles with a decreasing diameter at one end, the third subclass of light-diffusing particles is selected from needle-like particles with decreasing diameters at both ends, the fourth subclass of light-diffusing particles is selected from elongated conical particles, the fifth subclass of light-diffusing particles is selected from biconic particles and / or ellipsoidal particles, the sixth subclass of light-diffusing particles is selected from square-shaped particles or rectangular-shaped particles, the seventh subclass of light-diffusing particles is selected from spherical particles or ellipsoidal particles,the eighth subclass of light-diffusing particles is selected from needle-like particles with a decreasing diameter at one end, the ninth subclass of light-diffusing particles is selected from needle-like particles with a decreasing diameter at both ends, and the tenth subclass of light-diffusing particles is selected from elongated conical particles. [7] Light diffusion film according to claim 3, characterized by that the mass fraction of the fifth subclass of light-diffusing particles in the light-diffusing particles is greater than or equal to 20%, wherein the mass fraction of the fifth subclass of light-diffusing particles in the light-diffusing particles is less than or equal to 100%. [8] Light diffusion film according to claim 1, characterized bythat the light-diffusing particles have an average particle size, wherein the length of the long axis of any one of the light-diffusing particles is greater than or equal to 20% of the average particle size of the light-diffusing particles, and wherein the length of the long axis of any one of the light-diffusing particles is less than or equal to 180% of the average particle size of the light-diffusing particles. [9] Light diffusion film according to claim 1, characterized by that the substrate comprises a first sub-substrate and / or a second sub-substrate, wherein the first sub-substrate is at least one of unmodified polyester and unmodified cellulose acetate and the second sub-substrate is at least one of modified polyester and modified cellulose acetate; and wherein the mass fraction of the first sub-substrate in the substrate is greater than or equal to 65%, and wherein the mass fraction of the first sub-substrate in the substrate is less than or equal to 100%; and wherein the mass fraction of the second sub-substrate in the substrate is greater than or equal to 0%, and wherein the mass fraction of the second sub-substrate in the substrate is less than or equal to 35%. [10] Polarizer, characterized by that it comprises a light diffusion film according to any one of claims 1 to 9. [11] Display device, characterized by that it comprises a polarizer according to claim 10.

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