Optical film, polarizer and display device

Abstract

Exemplary embodiments of the present invention disclose an optical film, a polarizer, and a display device. The optical film comprises a base material and adjusting particles dispersed in the base material, wherein the optical film has an in-plane retardation value, and wherein the in-plane retardation value of the optical film is less than 3000 nm. In the present invention, the in-plane retardation value of the optical film is reduced to less than 3000 nm by adding the adjusting particles to the base material of the optical film, thus reducing the difference between the in-plane retardation value and the retardation value in the thickness direction of the optical film, thereby improving the problem of rainbow patterns caused by the optical film.

Description

Technical area

[0001] The present invention relates to the field of display, particularly to an optical film, a polarizer and a display device. State of the art

[0002] Currently, a polarizer typically has a polarizing layer, and an optical film is used as the protective layer of the polarizing layer to protect the polarizing layer. However, there is a problem that the optical film used for the protective layer has properties such as birefringence, which causes rainbow patterns when viewed in an oblique direction when the polarizer is used in a display device, resulting in a degraded display quality of the display device.

[0003] Therefore, there is an urgent need for an optical film, a polarizer and a display device to solve the above technical problem. Disclosure of the invention

[0004] The present invention provides an optical film, a polarizer, and a display device capable of alleviating the current technical problem of reduction in display quality of the display device due to rainbow patterns caused by the optical film.

[0005] The present invention provides an optical film comprising: a base material; Adjusting particles dispersed in the base material; wherein the optical film has an in-plane retardation value, and wherein the in-plane retardation value of the optical film is less than 3000 nm.

[0006] Preferably, the retardation value in the plane of the optical film is less than or equal to 1000 nm.

[0007] Preferably, the retardation value in the plane of the optical film is less than or equal to 500 nm.

[0008] Preferably, the retardation value in the plane of the optical film is less than or equal to 200 nm.

[0009] Preferably, the optical film has a retardation value in the thickness direction, wherein a ratio of the retardation value in the plane of the optical film to the retardation value in the thickness direction of the optical film is greater than 0.1, and wherein the ratio of the retardation value in the plane of the optical film to the retardation value in the thickness direction of the optical film is less than 2.

[0010] Preferably, the adjusting particles comprise adjusting particles of a first type and / or adjusting particles of a second type; wherein the first type adjustment particle has a plurality of first cross sections, each of the first cross sections having a first circumscribed circle, wherein a ratio of a length of a long axis of the first type adjustment particle to a diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles is greater than or equal to 1, wherein the ratio of the length of the long axis of the first type adjustment particle to the diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles is less than 5; wherein the second type adjustment particle has a plurality of second cross sections, each of the second cross sections having a second circumscribed circle, wherein a ratio of a length of a long axis of the second type adjustment particle to a diameter of the second circumscribed circle having the largest diameter among the plurality of second circumscribed circles is greater than or equal to 5, and wherein the ratio of the length of the long axis of the second type adjustment particle to the diameter of the second circumscribed circle having the largest diameter among the plurality of second circumscribed circles is less than or equal to 50.

[0011] Preferably, the first-type adjustment particle is selected from at least one of a first-subtype adjustment particle and a second-subtype adjustment particle having different shapes, and the second-type adjustment particle is selected from at least one of a sixth-subtype adjustment particle, a seventh-subtype adjustment particle, an eighth-subtype adjustment particle, a ninth-subtype adjustment particle, and a tenth-subtype adjustment particle having different shapes; wherein the first-type adjustment particle is selected from at least one of a first-subtype adjustment particle, a second-subtype adjustment particle, a third-subtype adjustment particle, a fourth-subtype adjustment particle, and a fifth-subtype adjustment particle, which have different shapes; wherein the second-type adjustment particle is selected from at least one of a sixth-subtype adjustment particle, a seventh-subtype adjustment particle, an eighth-subtype adjustment particle, a ninth-subtype adjustment particle, and a tenth-subtype adjustment particle, which have different shapes; wherein, along an extension direction of a long axis of the first subtype adjusting particle, a diameter of a first circumscribed circle of a first cross section of the first subtype adjusting particle has a change value of less than or equal to 0.3 µm; wherein a first end of the second sub-type adjustment particle is connected to a second end of the second sub-type adjustment particle, wherein along a direction away from the second end of the second sub-type adjustment particle, a diameter of a first circumscribed circle of a first cross-section located at the first end of the second sub-type adjustment particle gradually decreases, wherein along a direction away from the first end of the second sub-type adjustment particle, a diameter of a first circumscribed circle of a first cross-section located at the second end of the second sub-type adjustment particle gradually decreases; wherein, along an extension direction of a long axis of the third subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section located in a central part of the third subtype adjustment particle has a change value of less than or equal to 1 µm, wherein, along a direction away from the central part of the third subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section located at a first end of the third subtype adjustment particle gradually decreases, and a diameter of a first circumscribed circle of a first cross section located at a second end of the third subtype adjustment particle has a change value of less than or equal to 1 µm; wherein, along an extension direction of a long axis of the fourth subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section located in a central part of the fourth subtype adjustment particle has a change value of less than or equal to 1 µm, wherein, along a direction away from the central part of the fourth subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section located at a first end of the fourth subtype adjustment particle gradually decreases, and a diameter of a first circumscribed circle of a first cross section located at a second end of the fourth subtype adjustment particle gradually decreases; wherein a first end of the fifth subtype adjustment particle is connected to a second end of the fifth subtype adjustment particle, wherein a diameter of a first circumscribed circle of a first cross section of the fifth subtype adjustment particle gradually decreases along a direction from the first end of the fifth subtype adjustment particle to the second end of the fifth subtype adjustment particle; wherein, along an extension direction of a long axis of the adjusting particle of the sixth subtype, a diameter of a second circumscribed circle of a second cross section of the adjusting particle of the sixth subtype has a change value of less than or equal to 0.3 µm; wherein, along an extension direction of a long axis of the seventh subtype adjustment particle, a diameter of a second circumscribed circle of a second cross section located in a central part of the seventh subtype adjustment particle has a change value of less than or equal to 1 µm, wherein, along a direction away from the central part of the seventh subtype adjustment particle, a diameter of a second circumscribed circle of a second cross section located at a first end of the seventh subtype adjustment particle gradually decreases, and a diameter of a second circumscribed circle of a second cross section located at a second end of the seventh subtype adjustment particle has a change value of less than or equal to 1 µm; wherein, along an extension direction of a long axis of the eighth subtype adjustment particle, a diameter of a second circumscribed circle of a second cross section located in a central part of the eighth subtype adjustment particle has a change value of less than or equal to 1 µm, wherein, along a direction away from the central part of the eighth subtype adjustment particle, a diameter of a second circumscribed circle of a second cross section located at a first end of the eighth subtype adjustment particle gradually decreases, and a diameter of a second circumscribed circle of a second cross section located at a second end of the eighth subtype adjustment particle gradually decreases; wherein a first end of the ninth subtype adjustment particle is connected to a second end of the ninth subtype adjustment particle, wherein a diameter of a second circumscribed circle of a second cross section of the ninth subtype adjustment particle gradually decreases along a direction from the first end of the ninth subtype adjustment particle to the second end of the ninth subtype adjustment particle; wherein a first end of the adjustment particle of the tenth subtype is connected to a second end of the adjustment particle of the tenth subtype, wherein along a direction away from the second end of the adjustment particle of the tenth subtype, a diameter of a second circumscribed circle of a second cross-section located at the first end of the adjustment particle of the tenth subtype gradually decreases, and wherein along a direction away from the first end of the adjustment particle of the tenth subtype, a diameter of a second circumscribed circle of a second cross-section located at the second end of the adjustment particle of the tenth subtype gradually decreases.

[0012] Preferably, the adjusting particles comprise the adjusting particles of the first type and the adjusting particles of the second type, wherein a mass fraction of the adjusting particles of the first type in the adjusting particles is greater than 50% and a mass fraction of the adjusting particles of the second type in the adjusting particles is less than 50%.

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

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

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

[0016] In the present invention, the adjusting particles are added to the base material of the optical film to reduce the difference between the in-plane retardation value and the retardation value in the thickness direction of the optical film, thereby improving the problem of rainbow patterns caused by the optical film. Short description of the characters

[0017] In order to more clearly explain the technical solutions in the embodiments of the invention, the drawings required to describe the embodiments are briefly presented below. Obviously, the drawings in the following description represent only a few embodiments of the invention. Those skilled in the art can also derive further drawings based on these drawings without inventive activity. Fig.1 shows a schematic view of a first structure of an optical film according to an embodiment of the present invention; Fig. 2 shows a schematic view of a second structure of the optical film according to an embodiment of the present invention; Fig. 3 shows a schematic view of a third structure of the optical film according to an embodiment of the present invention; Fig. 4 shows a schematic view of a first structure of a polarizer according to an embodiment of the present invention; Fig. 5 shows a schematic view of a second structure of the polarizer according to an embodiment of the present invention; Fig. 6 shows a schematic view of a third structure of the polarizer according to an embodiment of the present invention; Fig.Fig. 7 shows a schematic view of a fourth structure of the polarizer according to an embodiment of the present invention; and Fig. 8 shows a schematic view of a structure of a display device according to an embodiment of the present invention. Detailed embodiments

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention and do not encompass all embodiments. All other embodiments achieved by those skilled in the art based on the embodiments in the present invention without inventive effort should be considered to be within the scope of the present invention. Furthermore, it should be understood that the detailed embodiments described herein are only for illustrating and explaining the present invention and are not intended to limit the present invention. Unless otherwise stated, the directional designations used such as "above" or"Bottom" in the present invention normally refers to an upper or lower position of a device in actual use or under working conditions, particularly to a direction of the plane of the drawing in the accompanying drawings; and the terms "inside" and "outside" are used with respect to the contour of a device.

[0019] Due to birefringence and other properties of an optical film used as a protective layer for a polarizing layer, there is currently a technical problem that when a polarizer is used in a display device, the display device exhibits rainbow patterns when viewed from an oblique direction, resulting in reduced display quality of the display device.

[0020] With reference to Fig.1 to 3, an embodiment of the present invention provides an optical film 101 comprising a base material 1011 and adjusting particles 1012, wherein the adjusting particles 1012 are dispersed in the base material 1011. The optical film 101 has an in-plane retardation value, wherein the in-plane retardation value of the optical film 101 is less than 3000 nm.

[0021] In the embodiments of the present invention, the in-plane retardation value of the optical film is reduced to less than 3000 nm by adding the adjusting particles 1012 to the base material 1011 of the optical film 101, so that the difference between the in-plane retardation value and the retardation value in the thickness direction of the optical film 101 is reduced, thereby improving the problem of rainbow patterns caused by the optical film 101.

[0022] The technical solutions of the present invention are described below in conjunction with the specific embodiments.

[0023] In the present embodiment, the in-plane retardation value of the optical film 101 refers to a retardation value of the optical film 101 in a plane in which the optical film 101 is located, the plane in which the optical film 101 is located being perpendicular to the thickness direction of the optical film 101. The optical film 101 has a thickness-direction retardation value in the thickness direction of the optical film 101. When light passes through the optical film 101, a difference between the in-plane retardation value and the thickness-direction retardation value of the optical film 101 is caused by a difference between a refractive index of the light in the plane in which the optical film 101 is located and a refractive index of the light in the thickness direction of the optical film 101.When the in-plane retardation value of the optical film 101 is greater than or equal to 3000 nm, the difference between the in-plane retardation value of the optical film 101 and the retardation value in the thickness direction of the optical film 101 is too large, so that in the case where the light passes through the optical film 101, a rainbow pattern phenomenon is generated when viewed from a large-angle direction (e.g., the angle with respect to the thickness direction of the optical film 101 is 45 degrees, 60 degrees, etc.).By adding the adjusting particles 1012, the difference between the refractive index of light in the plane where the optical film 101 is located and the refractive index of light in the thickness direction of the optical film 101 is reduced, so that the retardation value in the plane of the optical film 101 is less than 3000 nm, thereby improving the problem of the rainbow patterns of the optical film 101 in the large-angle direction and increasing the display quality of a display device including the optical film 101.

[0024] In some embodiments, the in-plane retardation value of the optical film 101 can be calculated by the following formula: Re=d×|nx−ny|; where Re represents the retardation value in the plane of the optical film 101, n x represents a refractive index for extraordinary light, n yrepresents a refractive index for ordinary light and d represents a thickness of the optical film 101.

[0025] In some embodiments, the in-plane retardation value of the optical film 101 may be a difference value between the extraordinary light refractive index and the ordinary light refractive index of the optical film 101 measured by a phase retardation meter (e.g., Optipro-micro from Shintech) under a white light source with continuous spectra, so that the in-plane retardation value of the optical film 101 is obtained by the above formula.

[0026] In some embodiments, a retardation amount in the thickness direction of the optical film 101 may be an average value of the products of anisotropy values ​​ΔN xz = Δ | n x - n z |, ΔN yz = Δ | n y - n z| two groups of refractive indices of the optical film 101, observed in the cross section perpendicular to the plane in which the optical film 101 is located, and the thickness of the optical film 101, where n z refractive index in the thickness direction of the optical film 101.

[0027] In some embodiments, it is provided that the in-plane retardation value of the optical film 101 is greater than or equal to 0 nm, and that the in-plane retardation value of the optical film 101 is less than or equal to 1000 nm, which is advantageous for reducing the difference between the in-plane retardation value of the optical film 101 and the retardation value in the thickness direction of the optical film 101. For example, this in-plane retardation value can be 20 nm, 50 nm, 100 nm, 120 nm, 150 nm, 200 nm, 220 nm, 250 nm, 300 nm, 320 nm, 350 nm, 400 nm, 420 nm, 450 nm, 500 nm, 520 nm, 550 nm, 600 nm, 620 nm, 650 nm, 700 nm, 720 nm, 750 nm, 800 nm, 820 nm, 850 nm, 900 nm, 920 nm, 950 nm, etc., thereby effectively improving the problem of the rainbow patterns of the optical film 101 in the large-angle direction and the display quality of the display device using the optical film 101.It is preferable that the in-plane retardation value of the optical film 101 is greater than or equal to 0 nm, and that the in-plane retardation value of the optical film 101 is less than or equal to 500 nm, which further effectively improves the problem of the rainbow patterns of the optical film 101 in the high-angle direction and the display quality of the display device including the optical film 101.More preferably, the in-plane retardation value of the optical film 101 is greater than or equal to 0 nm, and the in-plane retardation value of the optical film 101 is less than or equal to 200 nm, so that the range of the in-plane retardation value of the optical film 101 is closest to the range of the retardation value in the thickness direction of the optical film 101, thereby most effectively improving the problem of the rainbow patterns of the optical film 101 in the high-angle direction and the display quality of the display device including the optical film 101.

[0028] In some embodiments, the smaller the difference between the refractive index of light in the plane of the optical film 101 and the refractive index of light in the thickness direction of the optical film 101, the more conducive it is to eliminating the rainbow pattern problem when the ratio of the retardation value in the plane of the optical film 101 to the retardation value of the optical film 101 in the thickness direction is closer to 1. The ratio of the retardation value in the plane of the optical film 101 to the retardation value in the thickness direction of the optical film 101 is greater than 0.1, while the ratio of the retardation value in the plane of the optical film 101 to the retardation value in the thickness direction of the optical film 101 is less than 2. For example, it may be 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.4, 1.5, 1.6, 1.8, etc., which can effectively improve the rainbow pattern problem.Preferably, the problem of rainbow patterns can be substantially avoided when the ratio of the in-plane retardation value of the optical film 101 to the thickness-direction retardation value of the optical film 101 is greater than or equal to 0.5, and the ratio of the in-plane retardation value of the optical film 101 to the thickness-direction retardation value of the optical film 101 is less than or equal to 1.5. More preferably, the problem of rainbow patterns can be completely eliminated when the ratio of the in-plane retardation value of the optical film 101 to the thickness-direction retardation value of the optical film 101 is greater than or equal to 0.6, and the ratio of the in-plane retardation value of the optical film 101 to the thickness-direction retardation value of the optical film 101 is less than or equal to 1.2.

[0029] In some embodiments, the base material 1011 is selected from at least one of modified or unmodified polyester, modified or unmodified cellulose acetate.

[0030] In some embodiments, the modified or unmodified polyester may comprise at least one of modified or unmodified polyethylene terephthalate, modified or unmodified polycarbonate, modified or unmodified polymethyl methacrylate, and modified or unmodified polyethylene naphthalate. The modified or unmodified cellulose acetate may comprise modified or unmodified cellulose triacetate.

[0031] In some embodiments, the base material 1011 may comprise a first sub-base material and / or a second sub-base material, wherein the first sub-base material may be selected from at least one of unmodified polyester and unmodified cellulose acetate. The second sub-base material may be selected from at least one of modified polyester and modified cellulose acetate. In the base material 1011, the mass fraction of the first sub-base material is greater than the mass fraction of the second sub-base material.

[0032] In some embodiments, the first sub-base material and the second sub-base material are uniformly mixed with each other, wherein the mass fraction of the first sub-base material in the base material 1011 is greater than or equal to 65% and may be, for example, 70%, 75%, 80%, 85%, 90%, 95%, 99%, etc. The mass fraction of the second sub-base material in the base material 1011 is less than or equal to 35% and may be, for example, 1%, 5%, 10%, 15%, 20%, 25%, 30%, etc.Advantageously, the modified polyester such as polyethylene terephthalate has good mutual solubility with the unmodified polyester such as polyethylene terephthalate, or the modified cellulose acetate such as cellulose triacetate has good mutual solubility with the unmodified cellulose acetate such as cellulose triacetate, which contributes to improving the mechanical properties, flatness and crystallinity of the base material 1011 and improving the dispersion of the adjusting particles 1012, thereby improving the optical performance of the optical film 101.

[0033] In some embodiments, modified cellulose triacetate, modified polyethylene terephthalate, modified polycarbonate, modified polymethyl methacrylate, or modified polyethylene naphthalate can be obtained by subjecting unmodified cellulose triacetate, unmodified polyethylene terephthalate, unmodified polycarbonate, unmodified polymethyl methacrylate, or unmodified polyethylene naphthalate, respectively, to a hydrophilic modification or lipophilic modification. The modified polyethylene terephthalate can be obtained, for example, by introducing a linear alkyl side chain, a carboxyl side chain, a hydroxyl side chain, or a side chain of a fluorine-containing group into unmodified polyethylene terephthalate.If the modified polyethylene terephthalate can be obtained by introducing a carboxyl side chain and / or a hydroxyl side chain into unmodified polyethylene terephthalate, the modified polyethylene terephthalate can be obtained by introducing groups into the phenyl group of unmodified polyethylene terephthalate, where n and m are integers greater than or equal to 0 and less than or equal to 10.

[0034] In some embodiments, when the first sub-base material is selected from unmodified polyethylene terephthalate, the second sub-base material is selected from modified polyethylene terephthalate, it is advantageous that modified polyethylene terephthalate and unmodified polyethylene terephthalate have good mutual solubility, which contributes to improving the mechanical properties, flatness and crystallinity of the base material 1011 and improving the dispersion of the adjusting particles 1012, thereby improving the optical performance of the optical film 101.

[0035] In some embodiments, the adjustment particles 1012 each have a long axis and a diameter, wherein the length of the long axis of the adjustment particles 1012 is a distance between both endpoints of the long axis of the adjustment particles 1012, wherein each of the adjustment particles 1012 has a plurality of cross-sections in the extension direction perpendicular to the long axis of the adjustment particle, wherein each of the cross-sections has a circumscribed circle, wherein the diameter of the adjustment particles 1012 corresponds to a diameter of a circumscribed circle of the plurality of cross-sections that has the largest diameter. The two farthest points in a cross-section of the adjustment particle 1012 lie on the circumscribed circle of the cross-section, and the distance between the two farthest points in the cross-section is the diameter of the circumscribed circle.The adjustment particles 1012 comprise adjustment particles of a first type 1012a.

[0036] The first type adjustment particle 1012a has a plurality of first cross sections, each of the first cross sections having a first circumscribed circle, wherein a ratio of a length of a long axis of the first type adjustment particle 1012a to a diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles is greater than or equal to 1, wherein the ratio of the length of the long axis of the first type adjustment particle 1012a to the diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles is less than 5. For example, this ratio may 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, etc., and the first cross section is perpendicular to the extension direction of the long axis of the second type adjusting particle 1012b.By including the adjusting particles 1012 in the first type adjusting particles 1012a having a smaller length-to-diameter ratio (that is, the ratio of the length of the long axis to the diameter of the first circumscribed circle having the largest diameter), it is advantageous to effectively reduce the in-plane retardation value of the optical film 101 to less than 3000 nm and to effectively reduce the difference value between the in-plane retardation value of the optical film 101 and the retardation value in the thickness direction of the optical film 101, thereby improving the problem of rainbow patterns of the optical film 101 and the display quality of the display device including the optical film 101.

[0037] In some embodiments, the first type adjustment particle 1012a is selected from at least one of an adjustment particle of a first subtype, an adjustment particle of a second subtype, an adjustment particle of a third subtype, an adjustment particle of a fourth subtype, and an adjustment particle of a fifth subtype, which have different shapes.

[0038] In this case, along an extension direction of a long axis of the first subtype tuning particle, a diameter of a first circumscribed circle of a first cross section of the first subtype tuning particle has a change value of less than or equal to 0.3 µm. For example, the change value 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, etc.In some embodiments, it is provided that, along the extension direction of the long axis of the adjustment particle of the first subtype, a diameter of a first circumscribed circle of a first cross-section located at a first end of the adjustment particle of the first subtype is the same as a diameter of a first circumscribed circle of a first cross-section located in a central part of the adjustment particle of the first subtype, and a diameter of a first circumscribed circle of a first cross-section located at a second end of the adjustment particle of the first subtype is the same as a diameter of a first circumscribed circle of a first cross-section located in the central part of the adjustment particle of the first subtype.

[0039] In some embodiments, it is provided that the first cross section of the adjustment particle of the first subtype may have a regular shape such as a circle, an ellipse, a triangle, a quadrilateral, etc., or an irregular shape.

[0040] In some embodiments, it is provided that the adjustment particle of the first subtype is a cube-shaped particle or a cuboid-shaped particle, wherein the first cross section of the adjustment particle of the first subtype is square or rectangular, the diameter of the first circumscribed circle of any of the first cross sections of the adjustment particle of the first subtype is a diagonal length of the square or rectangle formed by the first cross section.

[0041] The ratio of the length of the long axis of the first subtype adjusting particle to the diameter of the first circumscribed circle having the largest diameter among the first circumscribed circles of the plurality of first cross sections of the first subtype adjusting particle is more preferably close to 1, and may be, for example, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 3, etc.

[0042] A first end of the second subtype adjustment particle is connected to a second end of the second subtype adjustment particle, wherein along a direction away from the second end of the second subtype adjustment particle, a diameter of a first circumscribed circle of a first cross-section located at the first end of the second subtype adjustment particle gradually decreases, wherein along a direction away from the first end of the second subtype adjustment particle, a diameter of a first circumscribed circle of a first cross-section located at the second end of the second subtype adjustment particle gradually decreases.

[0043] It is understood that the feature that “along a direction away from the second end of the second sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross section located at the first end of the second sub-type adjustment particle gradually decreases” means that along the direction away from the second end of the second sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross section located at the first end of the second sub-type adjustment particle presents a decreasing trend, which includes, but is not limited to: that along the direction away from the second end of the second sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross section located at the first end of the second sub-type adjustment particle sequentially decreases.

[0044] It is understood that the feature that “along a direction away from the first end of the second sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross section located at the second end of the second sub-type adjustment particle gradually decreases” means that along the direction away from the first end of the second sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross section located at the second end of the second sub-type adjustment particle presents a decreasing trend, which includes, but is not limited to: that along the direction away from the first end of the second sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross section located at the second end of the second sub-type adjustment particle sequentially decreases.

[0045] In some embodiments, it is contemplated that the first cross section of the second subtype tuning particle may have a regular shape such as a circle, an ellipse, a triangle, a quadrilateral, etc., or an irregular shape.

[0046] In some embodiments, the second subtype tuning particle is a spherical particle or a spheroidal particle, wherein the first cross-section of the second subtype tuning particle is circular or elliptical. If the first cross-section of the second subtype tuning particle is an ellipse, a ratio of the major axis of an ellipse of any of the first cross-sections of the second subtype tuning particle to the minor axis of the ellipse is greater than 1 and less than or equal to 3; for example, this ratio may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.When the second subtype adjustment particle is a spherical particle, any one of the first cross sections of the second subtype adjustment particle is circular, and the first circumscribed circle of any one of the first cross sections coincides with that first cross section, wherein the ratio of the length of the long axis of the second subtype adjustment particle to the diameter of the first circumscribed circle having the largest diameter among the plurality of first cross sections of the second subtype adjustment particle is 1.

[0047] The ratio of the long axis length of the second subtype adjustment particle to the diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles of the second subtype adjustment particle is preferably close to 1. When the second subtype adjustment particle is a spheroidal particle, its shape is more preferably approximately spherical. That is, the closer the long axis length of the second subtype adjustment particle and the diameter of the second subtype adjustment particle are to each other, the better.Preferably, the ratio of the length of the long axis of the adjusting particle of the second subtype to the diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles of the adjusting particle of the second subtype is greater than or equal to 1, wherein the ratio of the length of the long axis of the adjusting particle of the second subtype to the diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles of the adjusting particle of the second subtype is less than or equal to 3.More preferably, the ratio of the length of the long axis of the second subtype adjustment particle to the diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles of the second subtype adjustment particle is greater than or equal to 1, and the ratio of the length of the long axis of the second subtype adjustment particle to the diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles of the second subtype adjustment particle is less than or equal to 1.5.

[0048] Along an extension direction of a long axis of the third subtype adjusting particle, a diameter of a first circumscribed circle of a first cross section located in a central part of the third subtype adjusting particle has a change value of less than or equal to 1 µm. This change value can be, for example, 0 µm, 0.95 µm, 0.8 µm, 0.78 µm, 0.75 µm, 0.72 µm, 0.7 µm, 0.68 µm, 0.65 µm, 0.62 µm, 0.6 µm, 0.58 µm, 0.55 µm, 0.52 µm, 0.5 µm, 0.48 µm, 0.45 µm, 0.42 µm, 0.4 µm, 0.38 µm, 0.35 µm, 0.32 µm, 0.3 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 etc.

[0049] Along a direction away from the central part of the third subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section located at a first end of the third subtype adjustment particle gradually decreases, wherein a diameter of a first circumscribed circle of a first cross section located at a second end of the third subtype adjustment particle has a change value of less than or equal to 1 µm; and where this change value is, for example, 0 µm, 0.95 µm, 0.8 µm, 0.78 µm, 0.75 µm, 0.72 µm, 0.7 µm, 0.68 µm, 0.65 µm, 0.62 µm, 0.6 µm, 0.58 µm, 0.55 µm, 0.52 µm, 0.5 µm, 0.48 µm, 0.45 µm, 0.42 µm, 0.4 µm, 0.38 µm, 0.35 µm, 0.32 µm, 0.3 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 etc.In some embodiments, it is provided that along the direction away from the central part of the third subtype adjustment particle, the diameter of the first circumscribed circle of the first cross section located at the first end of the third subtype adjustment particle gradually decreases, and that the diameter of the first circumscribed circle of the first cross section located at the second end of the third subtype adjustment particle is the same as the diameter of the first circumscribed circle of the first cross section located in the central part of the third subtype adjustment particle.

[0050] It is understood that the feature that “along a direction away from the central part of the third sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross-section located at the first end of the third sub-type adjustment particle gradually decreases” means that along the direction away from the central part of the third sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross-section located at the first end of the third sub-type adjustment particle presents a decreasing trend, which includes, but is not limited to: that along the direction away from the central part of the third sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross-section located at the first end of the third sub-type adjustment particle sequentially decreases.

[0051] In some embodiments, it is contemplated that the first cross section of the third subtype adjustment particle may have a regular shape such as a circle, an ellipse, a triangle, a quadrilateral, etc., or an irregular shape.

[0052] In some embodiments, it is contemplated that the third subtype adjustment particle may be a needle-shaped particle having a reduced diameter at one end.

[0053] In some embodiments, the first cross-section of the third subtype tuning particle may be circular or elliptical if the third subtype tuning particle is a needle-shaped particle with a reduced diameter at one end. If the first cross-section located at the second end of the third subtype tuning particle or the first cross-section located in the middle part of the third subtype tuning particle is an ellipse, a ratio of the major axis of an ellipse of any of the first cross-sections located at the second end or in the middle part of the third subtype tuning particle to the minor axis of the ellipse is greater than 1 and less than or equal to 3, which ratio may be, for example, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.The shape of the first cross section located at the first end of the third subtype adjustment particle is consistent with the shape of the first cross section located in the central part of the third subtype adjustment particle, and its area gradually decreases along the direction away from the central part of the third subtype adjustment particle.

[0054] Along an extension direction of a long axis of the fourth subtype adjusting particle, a diameter of a first circumscribed circle of a first cross section located in a central part of the fourth subtype adjusting particle has a change value of less than or equal to 1 µm. This change value can be, for example, 0 µm, 0.95 µm, 0.8 µm, 0.78 µm, 0.75 µm, 0.72 µm, 0.7 µm, 0.68 µm, 0.65 µm, 0.62 µm, 0.6 µm, 0.58 µm, 0.55 µm, 0.52 µm, 0.5 µm, 0.48 µm, 0.45 µm, 0.42 µm, 0.4 µm, 0.38 µm, 0.35 µm, 0.32 µm, 0.3 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 etc.Along a direction away from the central part of the fourth subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section located at a first end of the fourth subtype adjustment particle gradually decreases, and a diameter of a first circumscribed circle of a first cross section located at a second end of the fourth subtype adjustment particle gradually decreases.In some embodiments, it is provided that along the extension direction of the long axis of the fourth subtype adjustment particle, the diameter of the first circumscribed circle of the first cross section located in the central part of the fourth subtype adjustment particle is uniform, and the diameter of the first circumscribed circle of the first cross section located at the first end of the fourth subtype adjustment particle and at the second end of the fourth subtype adjustment particle gradually changes.

[0055] It is understood that the feature that “along a direction away from the central part of the fourth sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross-section located at the first end of the fourth sub-type adjustment particle gradually decreases” means that along the direction away from the central part of the fourth sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross-section located at the first end of the fourth sub-type adjustment particle presents a decreasing trend, which includes, but is not limited to: that along the direction away from the central part of the fourth sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross-section located at the first end of the fourth sub-type adjustment particle sequentially decreases.

[0056] It is understood that the feature that “along a direction away from the central part of the fourth sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross section located at the second end of the fourth sub-type adjustment particle gradually decreases” means that along the direction away from the central part of the fourth sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross section located at the second end of the fourth sub-type adjustment particle presents a decreasing trend, which includes, but is not limited to: that along the direction away from the central part of the fourth sub-type adjustment particle, the diameter of the first circumscribed circle of the first cross section located at the second end of the fourth sub-type adjustment particle sequentially decreases.

[0057] In some embodiments, it is provided that the first cross section of the adjusting particle of the fourth subtype may have a regular shape such as a circle, an ellipse, a triangle, a quadrilateral, etc., or an irregular shape.

[0058] In some embodiments, it is contemplated that the adjusting particle of the fourth subtype may be a needle-shaped particle with reduced diameters at both ends.

[0059] In some embodiments, the first cross-section of the fourth subtype tuning particle may be circular or elliptical, if the fourth subtype tuning particle may be a needle-shaped particle with reduced diameters at both ends. If the first cross-section located in the central part of the fourth subtype tuning particle is an ellipse, a ratio of the major axis of an ellipse of any of the first cross-sections located in the central part of the fourth subtype tuning particle to the minor axis of the ellipse is greater than 1 and less than or equal to 3, where this ratio may be, for example, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.The shape of the first cross section located at the first end of the fourth subtype adjustment particle and the shape of the first cross section located at the second end of the fourth subtype adjustment particle are consistent with the shape of the first cross section located in the central part of the fourth subtype adjustment particle, and their areas gradually decrease along the direction away from the central part of the fourth subtype adjustment particle.

[0060] A first end of the fifth subtype adjustment particle is connected to a second end of the fifth subtype adjustment particle, wherein a diameter of a first circumscribed circle of a first cross section of the fifth subtype adjustment particle gradually decreases along a direction from the first end of the fifth subtype adjustment particle to the second end of the fifth subtype adjustment particle.

[0061] It is understood that the feature “along a direction from the first end of the fifth subtype adjustment particle to the second end of the fifth subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section of the fifth subtype adjustment particle gradually decreases” means that along the direction from the first end of the fifth subtype adjustment particle to the second end of the fifth subtype adjustment particle, the diameter of the first circumscribed circle of the first cross section of the fifth subtype adjustment particle presents a decreasing trend, which includes, but is not limited to: that along the direction from the first end of the fifth subtype adjustment particle to the second end of the fifth subtype adjustment particle, the diameter of the first circumscribed circle of the first cross section of the fifth subtype adjustment particle sequentially decreases.

[0062] In some embodiments, it is provided that the first cross section of the adjustment particle of the fifth subtype may have a regular shape such as a circle, an ellipse, a triangle, a quadrilateral, etc., or an irregular shape.

[0063] In some embodiments, it is provided that the adjusting particle of the fifth subtype may be a particle with an elongated conical shape.

[0064] In some embodiments, the first cross section of the fifth subtype tuning particle is circular or elliptical if the fifth subtype tuning particle is a particle with an elongated conical shape. Along the direction from the first end of the fifth subtype tuning particle to the second end of the fifth subtype tuning particle, the shape of the first cross section of the fifth subtype tuning particle is constant, and its area gradually decreases. If the first cross section of the fifth subtype tuning particle is an ellipse, a ratio of the major axis of an ellipse of any of the first cross sections of the fifth subtype tuning particle to the minor axis of the ellipse is greater than 1 and less than or equal to 3; for example, this ratio may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.

[0065] In some embodiments, it is provided that, compared with the third subtype adjustment particle, the fourth subtype adjustment particle, and the fifth subtype adjustment particle, the first subtype adjustment particle and the second subtype adjustment particle have a better improvement effect in reducing the difference between the in-plane retardation value of the optical film 101 and the retardation value in the thickness direction of the optical film 101, wherein the improvement effect of the second subtype adjustment particle is better than that of the first subtype adjustment particle. Therefore, it is preferably provided that the adjustment particles 1012 comprise the first subtype adjustment particles and / or the second subtype adjustment particles.If the adjustment particles 1012 comprise the adjustment particles of the first subtype and the adjustment particles of the second subtype, the mass fraction of the adjustment particle of the first subtype in the adjustment particles 1012 is greater than the mass fraction of the adjustment particle of the second subtype in the adjustment particles 1012. Preferably, the adjustment particles of the first type 1012a consist of the adjustment particles of the second subtype and / or the adjustment particles of the first subtype. More preferably, the adjustment particles of the first type 1012a consist of the adjustment particles of the second subtype.

[0066] With reference to Fig. 1, in some embodiments, the adjustment particles 1012 may consist of the adjustment particles of the first type 1012a.

[0067] With reference to Fig. 2 and Fig.3, in some embodiments, in order to reduce the problem of rainbow patterns of the optical film 101 and at the same time improve the viewing angle, the chromaticity, and the contrast of the optical film 101, the adjustment particles 1012 comprise adjustment particles of the second type 1012b.

[0068] The second-type adjustment particle 1012b has a plurality of second cross sections, each of the second cross sections having a second circumscribed circle, wherein a ratio of a length of a long axis of the second-type adjustment particle 1012b to a diameter of the second circumscribed circle having the largest diameter among the plurality of second circumscribed circles is greater than or equal to 5, wherein the ratio of the length of the long axis of the second-type adjustment particle 1012b to the diameter of the second circumscribed circle having the largest diameter among the plurality of second circumscribed circles is less than 100, wherein the second cross section runs perpendicular to the extension direction of the long axis of the second-type adjustment particle 1012b, wherein this 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 etc.The diameter of the second circumscribed circle of one of the second cross sections of the second-type adjustment particle 1012b is the distance between the two farthest points in this second cross section. By using the second-type adjustment particle 1012b with a larger length-to-diameter ratio (that is, the ratio of the length of the long axis to the diameter of the second circumscribed circle with the largest diameter), it is easier to change the propagation direction of more light through the adjustment particles 1012. While improving the problem of rainbow patterns, it is also advantageous to achieve the improvement effect of the adjustment particles 1012 on the viewing angle of chromaticity and contrast.

[0069] Compared with the first subtype adjusting particle 1012a, the second subtype adjusting particle 1012b has a slightly weaker improvement effect in reducing the difference between the in-plane retardation value of the optical film 101 and the retardation value in the thickness direction of the optical film 101; and a smaller number of second type adjusting particles 1012b can significantly improve the viewing angle of the chromaticity of the optical film 101. Therefore, a mass fraction of the second type adjustment particle 1012b in the adjustment particles 1012 is less than a mass fraction of the first type adjustment particle 1012a in the adjustment particles 1012. For example, the mass fraction of the first type adjustment particle 1012a in the adjustment particles 1012 is greater than 50%, while the mass fraction of the second type adjustment particle 1012b in the adjustment particles 1012 is less than 50%.The mass fraction of the first type adjusting particle 1012a in the adjusting particles 1012 can be 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, etc.

[0070] In some embodiments, the second type adjustment particle 1012b is selected from at least one of an adjustment particle of a sixth subtype, an adjustment particle of a seventh subtype, an adjustment particle of an eighth subtype, an adjustment particle of a ninth subtype, and an adjustment particle of a tenth subtype, which have different shapes; wherein, along an extension direction of a long axis of the adjustment particle of the sixth subtype, a diameter of a second circumscribed circle of a second cross section of the adjustment particle of the sixth subtype has a change value of less than or equal to 0.3 µm, and wherein the change value can be, for example, 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, etc.In some embodiments, it is provided that, along the extension direction of the long axis of the adjustment particle of the sixth subtype, a diameter of a second circumscribed circle of a second cross section located at a first end of the adjustment particle of the sixth subtype is the same as a diameter of a second circumscribed circle of a second cross section located in a central part of the adjustment particle of the sixth subtype, and a diameter of a second circumscribed circle located at the second end of the adjustment particle of the sixth subtype is the same as a diameter of a second circumscribed circle located in the central part of the adjustment particle of the sixth subtype.

[0071] In some embodiments, it is provided that the second cross section of the adjustment particle of the sixth subtype may have a regular shape such as a circle, an ellipse, a triangle, a quadrilateral, etc., or an irregular shape.

[0072] In some embodiments, it is contemplated that the sixth-type tuning particle may be a rod-shaped particle. If the sixth-type tuning particle is rod-shaped, the second cross-section of the sixth-type tuning particle is circular or elliptical. If the second cross-section of the sixth-subtype tuning particle is circular, the second circumscribed circle of the second cross-section of the sixth-subtype tuning particle may coincide with the second cross-section.If the second cross-section of the adjusting particle of the sixth subtype is an ellipse, the diameter of the second circumscribed circle of each of the second cross-sections of the adjusting particle of the sixth subtype is the length of the major axis of the ellipse formed by each of the second cross-sections of the adjusting particle of the sixth subtype, wherein a ratio of the major axis of the ellipse of one of the second cross-sections of the adjusting particle of the sixth subtype to the minor axis of the ellipse of this second cross-section of the adjusting particle of the sixth subtype is greater than 1 and less than or equal to 3, wherein this ratio can be, for example, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.

[0073] Along an extension direction of a long axis of the seventh subtype adjusting particle, a diameter of a second circumscribed circle of a second cross section located in a central part of the seventh subtype adjusting particle has a change value of less than or equal to 1 µm. This change value can be, for example, 0 µm, 0.95 µm, 0.8 µm, 0.78 µm, 0.75 µm, 0.72 µm, 0.7 µm, 0.68 µm, 0.65 µm, 0.62 µm, 0.6 µm, 0.58 µm, 0.55 µm, 0.52 µm, 0.5 µm, 0.48 µm, 0.45 µm, 0.42 µm, 0.4 µm, 0.38 µm, 0.35 µm, 0.32 µm, 0.3 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 etc.Along a direction away from the central part of the seventh subtype adjustment particle, a diameter of a second circumscribed circle of a second cross section located at a first end of the seventh subtype adjustment particle gradually decreases, wherein a diameter of a second circumscribed circle of a second cross section located at a second end of the seventh subtype adjustment particle has a change value of less than or equal to 1 µm. This change value can be, for example, 0 µm, 0.95 µm, 0.8 µm, 0.78 µm, 0.75 µm, 0.72 µm, 0.7 µm, 0.68 µm, 0.65 µm, 0.62 µm, 0.6 µm, 0.58 µm, 0.55 µm, 0.52 µm, 0.5 µm, 0.48 µm, 0.45 µm, 0.42 µm, 0.4 µm, 0.38 µm, 0.35 µm, 0.32 µm, 0.3 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 etc.In some embodiments, it is provided that along the direction away from the central part of the adjustment particle of the seventh subtype, the diameter of the second circumscribed circle of the second cross-section located at the first end of the adjustment particle of the seventh subtype gradually decreases, and that the diameter of the second circumscribed circle of the second cross-section located at the second end of the adjustment particle of the seventh subtype is the same as the diameter of the second circumscribed circle of the second cross-section located in the central part of the adjustment particle of the seventh subtype.

[0074] It is understood that the feature that “along a direction away from the central part of the adjustment particle of the seventh subtype, the diameter of the second circumscribed circle of the second cross section located at the first end of the adjustment particle of the seventh subtype gradually decreases” means that along the direction away from the central part of the adjustment particle of the seventh subtype, the diameter of the second circumscribed circle of the second cross section located at the first end of the adjustment particle of the seventh subtype presents a decreasing trend, which includes, but is not limited to: that along the direction away from the central part of the adjustment particle of the seventh subtype, the diameter of the second circumscribed circle of the second cross section located at the first end of the adjustment particle of the seventh subtype sequentially decreases.

[0075] In some embodiments, it is provided that the second cross section of the adjustment particle of the seventh subtype may have a regular shape such as a circle, an ellipse, a triangle, a quadrilateral, etc., or an irregular shape.

[0076] In some embodiments, it is contemplated that the adjusting particle of the seventh subtype may be a needle-shaped particle having a reduced diameter at one end.

[0077] In some embodiments, the second cross section of the seventh subtype tuning particle may be circular or elliptical if the seventh subtype tuning particle is a needle-shaped particle with a reduced diameter at one end. If the second cross section located at the second end of the seventh subtype tuning particle or the second cross section located in the middle part of the seventh subtype tuning particle is an ellipse, a ratio of the major axis of an ellipse of any of the second cross sections located at the second end or in the middle part of the seventh subtype tuning particle to the minor axis of the ellipse is greater than 1 and less than or equal to 3, for example, this ratio may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.The shape of the second cross section located at the first end of the seventh subtype adjustment particle is consistent with the shape of the second cross section located in the central part of the seventh subtype adjustment particle, and its area gradually decreases along the direction away from the central part of the seventh subtype adjustment particle.

[0078] Along an extension direction of a long axis of the eighth subtype adjusting particle, a diameter of a second circumscribed circle of a second cross section located in a central part of the eighth subtype adjusting particle has a change value of less than or equal to 1 µm. This change value can be, for example, 0 µm, 0.95 µm, 0.8 µm, 0.78 µm, 0.75 µm, 0.72 µm, 0.7 µm, 0.68 µm, 0.65 µm, 0.62 µm, 0.6 µm, 0.58 µm, 0.55 µm, 0.52 µm, 0.5 µm, 0.48 µm, 0.45 µm, 0.42 µm, 0.4 µm, 0.38 µm, 0.35 µm, 0.32 µm, 0.3 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 etc.Along a direction away from the central part of the eighth subtype adjustment particle, a diameter of a second circumscribed circle of a second cross section located at a first end of the eighth subtype adjustment particle gradually decreases, and a diameter of a second circumscribed circle of a second cross section located at a second end of the eighth subtype adjustment particle gradually decreases.In some embodiments, it is provided that along the extension direction of the long axis of the eighth subtype adjustment particle, the diameter of the second circumscribed circle of the second cross section located in the central part of the eighth subtype adjustment particle is uniform, and the diameter of the second circumscribed circle of the second cross section located at the first end of the eighth subtype adjustment particle and at the second end of the eighth subtype adjustment particle gradually changes.

[0079] It is understood that the feature that “along a direction away from the central part of the adjustment particle of the eighth subtype, the diameter of the second circumscribed circle of the second cross section located at the first end of the adjustment particle of the eighth subtype gradually decreases” means that along the direction away from the central part of the adjustment particle of the eighth subtype, the diameter of the second circumscribed circle of the second cross section located at the first end of the adjustment particle of the eighth subtype presents a decreasing trend, which includes, but is not limited to: that along the direction away from the central part of the adjustment particle of the eighth subtype, the diameter of the second circumscribed circle of the second cross section located at the first end of the adjustment particle of the eighth subtype sequentially decreases.

[0080] It is understood that the feature that “along a direction away from the central part of the adjustment particle of the eighth subtype, the diameter of the second circumscribed circle of the second cross section located at the second end of the adjustment particle of the eighth subtype gradually decreases” means that along the direction away from the central part of the adjustment particle of the eighth subtype, the diameter of the second circumscribed circle of the second cross section located at the second end of the adjustment particle of the eighth subtype presents a decreasing trend, which includes, but is not limited to: that along the direction away from the central part of the adjustment particle of the eighth subtype, the diameter of the second circumscribed circle of the second cross section located at the second end of the adjustment particle of the eighth subtype sequentially decreases.

[0081] In some embodiments, it is provided that the second cross section of the adjustment particle of the eighth subtype may have a regular shape such as a circle, an ellipse, a triangle, a quadrilateral, etc., or an irregular shape.

[0082] In some embodiments, it is contemplated that the adjusting particle of the eighth subtype may be a needle-shaped particle with reduced diameters at both ends.

[0083] In some embodiments, the second cross section of the eighth subtype tuning particle may be circular or elliptical, if the eighth subtype tuning particle may be a needle-shaped particle with reduced diameters at both ends. If the second cross section located in the central part of the eighth subtype tuning particle is an ellipse, a ratio of the major axis of an ellipse of any of the second cross sections located in the central part of the eighth subtype tuning particle to the minor axis of the ellipse is greater than 1 and less than or equal to 3, where this ratio may be, for example, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.The shape of the second cross section located at the first end of the eighth subtype adjustment particle and the shape of the second cross section located at the second end of the eighth subtype adjustment particle are consistent with the shape of the second cross section located in the central part of the eighth subtype adjustment particle, and their areas gradually decrease along the direction away from the central part of the eighth subtype adjustment particle.

[0084] A first end of the ninth subtype adjustment particle is connected to a second end of the ninth subtype adjustment particle, wherein a diameter of a second circumscribed circle of a second cross section of the ninth subtype adjustment particle gradually decreases along a direction from the first end of the ninth subtype adjustment particle to the second end of the ninth subtype adjustment particle.

[0085] It is understood that the feature “along a direction from the first end of the adjustment particle of the ninth subtype to the second end of the adjustment particle of the ninth subtype, a diameter of a second circumscribed circle of a second cross section of the adjustment particle of the ninth subtype gradually decreases” means that along the direction from the first end of the adjustment particle of the ninth subtype to the second end of the adjustment particle of the ninth subtype, the diameter of the second circumscribed circle of the second cross section of the adjustment particle of the ninth subtype presents a decreasing trend, which includes, but is not limited to: that along the direction from the first end of the adjustment particle of the ninth subtype to the second end of the adjustment particle of the ninth subtype, the diameter of the second circumscribed circle of the second cross section of the adjustment particle of the ninth subtype sequentially decreases.

[0086] In some embodiments, it is provided that the second cross section of the adjustment particle of the ninth subtype may have a regular shape such as a circle, an ellipse, a triangle, a quadrilateral, etc., or an irregular shape.

[0087] In some embodiments, it is provided that the adjusting particle of the ninth subtype may be a particle with an elongated conical shape.

[0088] In some embodiments, the second cross section of the ninth subtype adjustment particle is circular or elliptical if the ninth subtype adjustment particle is a particle with an elongated conical shape. Along the direction from the first end of the ninth subtype adjustment particle to the second end of the ninth subtype adjustment particle, the shape of the second cross section of the ninth subtype adjustment particle is constant, and its area gradually decreases. If the second cross section of the ninth subtype adjustment particle is an ellipse, a ratio of the major axis of an ellipse of any of the second cross sections of the ninth subtype adjustment particle to the minor axis of the ellipse is greater than 1 and less than or equal to 3; for example, this ratio may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.

[0089] A first end of the adjustment particle of the tenth subtype is connected to a second end of the adjustment particle of the tenth subtype, wherein along a direction away from the second end of the adjustment particle of the tenth subtype, a diameter of a second circumscribed circle of a second cross-section located at the first end of the adjustment particle of the tenth subtype gradually decreases, and wherein along a direction away from the first end of the adjustment particle of the tenth subtype, a diameter of a second circumscribed circle of a second cross-section located at the second end of the adjustment particle of the tenth subtype gradually decreases.

[0090] It is understood that the feature that “along a direction away from the second end of the adjusting particle of the tenth subtype, the diameter of the second circumscribed circle of the second cross section located at the first end of the adjusting particle of the tenth subtype gradually decreases” means that along the direction away from the second end of the adjusting particle of the tenth subtype, the diameter of the second circumscribed circle of the second cross section located at the first end of the adjusting particle of the tenth subtype presents a decreasing trend, which includes, but is not limited to: that along the direction away from the second end of the adjusting particle of the tenth subtype, the diameter of the second circumscribed circle of the second cross section located at the first end of the adjusting particle of the tenth subtype sequentially decreases.

[0091] It is understood that the feature that “along a direction away from the first end of the adjusting particle of the tenth subtype, the diameter of the second circumscribed circle of the second cross section located at the second end of the adjusting particle of the tenth subtype gradually decreases” means that along the direction away from the first end of the adjusting particle of the tenth subtype, the diameter of the second circumscribed circle of the second cross section located at the second end of the adjusting particle of the tenth subtype presents a decreasing trend, which includes, but is not limited to: that along the direction away from the first end of the adjusting particle of the tenth subtype, the diameter of the second circumscribed circle of the second cross section located at the second end of the adjusting particle of the tenth subtype sequentially decreases.

[0092] In some embodiments, it is provided that the second cross section of the adjusting particle of the tenth subtype may have a regular shape such as a circle, an ellipse, a triangle, a quadrilateral, etc., or an irregular shape.

[0093] In some embodiments, it is provided that the adjusting particle of the tenth subtype can be a biconic particle and / or a spheroidal particle.

[0094] In some embodiments, the second cross-section of the tuning particle of the tenth subtype is circular or elliptical if the tuning particle of the tenth subtype is a biconic particle and / or a spheroidal particle. Along the direction away from the second end of the tuning particle of the tenth subtype, the shape of the second cross-section located at the first end of the tuning particle of the tenth subtype is constant, and its area gradually decreases. Along the direction away from the first end of the tuning particle of the tenth subtype, the shape of the second cross-section located at the second end of the tuning particle of the tenth subtype is constant, and its area gradually decreases.When the second cross section of the adjusting particle of the tenth subtype is an ellipse, a ratio of the major axis of an ellipse of any of the second cross sections of the adjusting particle of the tenth subtype to the minor axis of the ellipse is greater than 1 and less than or equal to 3; for example, this ratio may be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.

[0095] A biconic particle as a tuning particle of the tenth subtype differs from a spheroidal particle as a tuning particle of the tenth subtype in that: If the tuning particle of the tenth subtype is a biconic particle, a cross-section of the tuning particle of the tenth subtype in a direction parallel to the long axis of the tuning particle of the tenth subtype represents a triangle, a quadrilateral, or another polygon; if the tuning particle of the tenth subtype is a spheroidal particle, the cross-section of the tuning particle of the tenth subtype in the direction parallel to the long axis of the tuning particle of the tenth subtype is elliptical.

[0096] In some embodiments, the length of the long axis of the second type adjustment particle 1012b is greater than or equal to 1 µm, and the length of the long axis of the second type adjustment particle 1012b is less than or equal to 200 µm, for example, this length may be 5 µm, 10 µm, 50 µm, 60 µm, 70 µm, 80 µm, 90 µm, 100 µm, 120 µm, 150 µm, 180 µm, etc., in order to effectively improve the viewing angle of the chromaticity of the optical film 101 while reducing the problem of the rainbow patterns of the optical film 101.Preferably, the length of the long axis of the second type adjustment particle 1012b is greater than or equal to 40 µm, and the length of the long axis of the second type adjustment particle 1012b is less than or equal to 100 µm, whereby the dimensions of the second type adjustment particles 1012b are more uniform, which contributes to a further comprehensive improvement in the optical performance of the optical film 101.

[0097] In some embodiments, it is provided that the mass fraction of the adjustment particle of the second subtype in the adjustment particles 1012 is greater than the mass fraction of the adjustment particle of the first subtype in the adjustment particles 1012 and the mass fraction of the adjustment particle of the first subtype in the adjustment particles 1012 is greater than or equal to the mass fraction of the adjustment particle of the second type 1012b in the adjustment particles 1012 when the adjustment particles 1012 comprise the adjustment particles of the first type 1012a and the adjustment particles of the second type 1012b and the adjustment particles of the first type 1012a comprise the adjustment particles of the first subtype and the adjustment particles of the second subtype.

[0098] In some embodiments, it is provided that the mass fraction of the adjustment particle of the first subtype in the adjustment particles 1012 is greater than or equal to 50% and can be, for example, 55%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, 100%, etc. The mass fraction of the adjustment particle of the second subtype in the adjustment particles 1012 is less than or equal to 25% and can be, for example, 20%, 15%, 10%, 5%, 3%, 1%, 0%. The mass fraction of the adjustment particle of the second type 1012b in the adjustment particles 1012 is less than or equal to 25% and can be, for example, 20%, 15%, 10%, 5%, 3%, 1%, 0%.

[0099] In some embodiments, the second type adjustment particle 1012b is selected from at least two of an adjustment particle of the sixth subtype, an adjustment particle of the seventh subtype, an adjustment particle of the eighth subtype, an adjustment particle of the ninth subtype, and an adjustment particle of the tenth subtype.Preferably, the adjustment particles of the second type 1012b are a mixture of the adjustment particle of the sixth subtype, the adjustment particle of the seventh subtype, and the adjustment particle of the eighth subtype; or that the adjustment particles of the second type 1012b are a mixture of the adjustment particle of the sixth subtype, the adjustment particle of the ninth subtype, and the adjustment particle of the tenth subtype; or that the adjustment particles of the second type 1012b are a mixture of the adjustment particle of the sixth subtype, the adjustment particle of the seventh subtype, the adjustment particle of the eighth subtype, the adjustment particle of the ninth subtype, and the adjustment particle of the tenth subtype.By selecting the second type adjustment particles 1012b from at least two types of particles having different shapes, the shape diversity of the second type adjustment particles 1012b is increased and the optical anisotropy of the second type adjustment particles 1012b is increased, which contributes to improving the effect of the second type adjustment particles 1012b on improving contrast and brightness.In the case where the second-type adjustment particles 1012b are selected from the sixth-subtype adjustment particle, the seventh-subtype adjustment particle, and the eighth-subtype adjustment particle, or the second-type adjustment particles 1012b are selected from the sixth-subtype adjustment particle, the ninth-subtype adjustment particle, and the tenth-subtype adjustment particle, or the second-type adjustment particles 1012b are a mixture of the sixth-subtype adjustment particle, the seventh-subtype adjustment particle, the eighth-subtype adjustment particle, the ninth-subtype adjustment particle, and the tenth-subtype adjustment particle, a mass fraction of the sixth-subtype adjustment particle in the second-type adjustment particles 1012b is 1% to 8%, wherein this mass fraction is, for example, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 6.5%, 7%, 7.5%, etc.wherein a mass fraction of the adjusting particle of the seventh subtype and / or the adjusting particle of the ninth subtype in the adjusting particles of the second type 1012ba is 40% to 50% and can be, for example, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, etc.; and wherein a mass fraction of the adjusting particle of the eighth subtype and / or the adjusting particle of the tenth subtype in the adjusting particles of the second type 1012b is 45% to 55% and can be, for example, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, etc. Mixing the adjustment particle of the sixth subtype, the adjustment particle of the seventh subtype and / or the adjustment particle of the ninth subtype, or the adjustment particle of the eighth subtype and / or the adjustment particle of the tenth subtype according to the above-mentioned proportions contributes to further improving the achieved improvement effect of the adjustment particles 1012 with respect to contrast and brightness.

[0100] In some embodiments, it is provided that a mass fraction of the adjusting particles 1012 in the optical film 101 is less than or equal to 20%, and may be, for example, 0.0001%, 0.001%, 0.01%, 0.02%, 0.05%, 0.1%, 0.5%, 1%, 5%, 8%, 10%, 12%, 15%, 18%, etc., in order to be uniformly dispersed in the optical film 101, so that the problem of the rainbow patterns of the optical film 101 in the high-angle direction and the display quality of the display device with the optical film 101 are effectively improved. Even a smaller mass fraction of the adjusting particles 1012 in the optical film 101 can effectively reduce the rainbow pattern of the optical film 101 in the high-angle direction. The smaller the mass fraction, the better the dispersion. Preferably, the mass fraction of the adjusting particles 1012 in the optical film 101 is less than or equal to 10%. Further preferably, the mass fraction of the adjusting particles 1012 in the optical film 101 is less than or equal to 5%.More preferably, the mass fraction of the adjusting particles 1012 in the optical film 101 is less than or equal to 1%. Particularly preferably, the mass fraction of the adjusting particles 1012 in the optical film 101 is less than or equal to 0.05%. At the same time, to ensure that the number of adjusting particles 1012 in the optical film 101 is sufficient to effectively improve the rainbow pattern of the optical film 101 in the high-angle direction, the mass fraction of the adjusting particles 1012 in the optical film 101 can be greater than or equal to 0.001%, preferably greater than or equal to 0.003%, further preferably greater than or equal to 0.005%, even more preferably greater than or equal to 0.015%, and particularly preferably greater than or equal to 0.03%.

[0101] In some embodiments, the second-type adjustment particle 1012b is a whisker. The material of the first-type adjustment particle 1012a and the second-type adjustment particle 1012b are selected from at least one of silicon dioxide, silicon carbide, silicon nitride, zinc oxide, magnesium oxide, aluminum oxide, calcium sulfate, calcium carbonate, potassium titanate, and aluminum borate.

[0102] In some embodiments, the second-type tuning particle 1012b and / or the first-type tuning particle 1012a may be surface-modified to facilitate the dispersion of the second-type tuning particle 1012b and / or the first-type tuning particle 1012ab in the base material 1011 or to improve the functionality, e.g., toughness, of the second-type tuning particle 1012b and / or the first-type tuning particle 1012a. When the second-type tuning particle 1012b and / or the first-type tuning particle 1012a is surface-modified, the surface of the second-type tuning particle 1012b and / or the first-type tuning particle 1012a is modified with at least one substance selected from the group consisting of inorganic cations, inorganic anions, polymers, adhesion promoters, or surfactants.That is, the surface of the second type adjusting particle 1012b and / or the first type adjusting particle 1012a comprises at least one of the following groups: an inorganic cationic group, an inorganic anionic group, a polymer group, an adhesion promoter group, and a surfactant group.

[0103] In particular, the surface of the second-type adjustment particle 1012b and / or the first-type adjustment particle 1012a is modified with at least one substance selected from the following: magnesium chloride, calcium chloride, barium chloride, strontium chloride, stearic acid, sodium stearate, zinc stearate, sulfonic acid surfactant, sulfonate surfactant, titanate, aluminate, polyacrylamide, silane, alkyl phosphate ester, aryl phosphate ester, alkyl phosphate, aryl phosphate, alkyl alcohol amide phosphate ester, alkyl alcohol amide phosphate, imidazoline phosphate ester, imidazoline phosphate, high polyphosphate ester, high polyphosphate, and silicone phosphate ester. Preferably, the surface of the second-type adjustment particle 1012b and / or the first-type adjustment particle 1012a is modified with at least one of a sulfonic acid surfactant or a sulfonate surfactant. The sulfonic acid surfactant may be selected from at least one of alkylsulfonate and fluoroalkylsulfonate.In particular, it can be selected, for example, from at least one of sodium dodecylsulfonate, sodium dodecylbenzenesulfonate, and sodium fluorododecylsulfonate. The sulfonate surfactant can be selected from at least one of mercaptan and fluorinated mercaptan. In particular, it can be selected, for example, from at least one of octyl mercaptan, dodecyl mercaptan, tetradecane mercaptan, octadecane mercaptan, fluorooctyl mercaptan, and fluorododecyl mercaptan.When the sulfonic acid surfactant is mixed with the adjusting particles 1012 whose surface is to be modified, the sulfonic acid surface-active groups form a sulfonic acid shell layer on the whisker surface, such as a benzene ring sulfonate group shell layer, which is advantageous for protecting the adjusting particles 1012, increasing the toughness of the adjusting particles 1012, and reducing the breakage of the second-type adjusting particle 1012b and / or the first-type adjusting particle 1012a in the optical film 101. When the sulfonate surfactant groups are mixed with the adjusting particles 1012 whose surface is to be modified, the sulfonate surface-active groups form an OSO cross-linked network with the hydroxyl groups on the whisker surface, and the bond energy of OSO is relatively large.This contributes to protecting the second-type adjustment particle 1012b and / or the first-type adjustment particle 1012a during a process in which the second-type adjustment particle 1012b and / or the first-type adjustment particle 1012a are mixed with the material of the base material 1011 and the optical film 101 is formed, reducing breakage of the second-type adjustment particle 1012b and / or the first-type adjustment particle 1012a, and improving the improvement effect of the second-type adjustment particle 1012b and / or the first-type adjustment particle 1012a on optical functions such as contrast and brightness.More preferably, the second-type tuning particle 1012b and / or the first-type tuning particle 1012a are modified with at least one of a sulfonic acid surfactant containing a fluorine substituent and a sulfonate surfactant containing a fluorine substituent, particularly, modified with, for example, at least one of sodium fluorododecylsulfonate, fluorooctyl mercaptan, and fluorododecyl mercaptan. The fluorine atom has high stability in the alkyl chain. The bond energy of the carbon-fluorine bond is higher than that of the carbon-carbon bond, and the carbon-fluorine bond has a shielding effect on the carbon-carbon bond, which has a positive effect on the protection of the carbon-carbon bond. This improves the stability of the second-type tuning particle 1012b and / or the first-type tuning particle 1012a.

[0104] In some embodiments, a difference in the refractive index between the base material 1011 and the adjustment particles 1012 is greater than or equal to 0.02, and may be, for example, 0.03, 0.05, 0.09, 0.1, 0.15, 0.2, etc. This makes it easier for the adjustment particles 1012 to achieve a light scattering function while reducing the problem of rainbow patterns of the optical film 101, thereby further improving the optical performance of the optical film 101. Preferably, the difference in the refractive index between the base material 1011 and the adjustment particles 1012 is greater than or equal to 0.1, and may be, for example, 0.12, 0.13, 0.14, 0.15, 0.2, etc.

[0105] In some embodiments, the base material 1011 has a glass transition temperature of 70°C to 600°C, wherein this glass transition temperature 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, etc.

[0106] In some embodiments, the base material 1011 has a modulus of elasticity of 500 MPa to 5000 MPa at 23°C, wherein this modulus of elasticity 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, etc.

[0107] In some embodiments, the elastic modulus of the base material 1011 can be maintained at a humidity of 50%.

[0108] In some embodiments, it is provided that the thickness of the optical film 101 is greater than or equal to 5 µm, and that the thickness of the optical film 101 is less than or equal to 500 µm, wherein this thickness may be, for example, 10 µm, 50 µm, 60 µm, 100 µm, 150 µm, 200 µm, 250 µm, 300 µm, 350 µm, 400 µm, 450 µm, etc., in order to facilitate the processing and recovery of the optical film 101 and to maintain an appropriate light transmittance of the optical film 101. Preferably, the thickness of a light scattering film is greater than or equal to 15 µm, and the thickness of the light scattering film is less than or equal to 150 µm, wherein this thickness may be, for example, 20 µm, 25 µm, 30 µm, 40 µm, 50 µm, 60 µm, 80 µm, 100 µm, 120 µm, 130 µm, 140 µm, etc.

[0109] In the optical film 101 according to the embodiments of the present invention, the adjusting particles 1012 are added to the base material 1011 of the optical film 101 to reduce the difference between the in-plane retardation value and the retardation value in the thickness direction of the optical film 101, thereby improving the problem of rainbow patterns caused by the optical film 101.

[0110] With reference to Fig. 4 to Fig. 7, an embodiment of the present invention further provides a polarizer 100 comprising an optical film 101 described above.

[0111] The polarizer 100 further includes a polarizing layer 102 located on one side of the optical film 101.

[0112] With reference to Fig. 4 to Fig.7, in some embodiments, the polarizer 100 further comprises a second optical functional layer 103 located on at least one side of the base material 1011.

[0113] The second optical functional layer 103 is located between the polarization layer 102 and the optical film 101. Alternatively, the second optical functional layer 103 is located on a side of the optical film 101 remote from the polarization layer 102.

[0114] In some embodiments, the second optical functional layer 103 is located on a side of the optical film 101 remote from the polarization layer 102, wherein the polarizer 100 further comprises a first adhesive layer 104 located on the optical film 101 and proximate the polarization layer 102.

[0115] The first adhesive layer 104 is in direct contact with the polarization layer 102. Alternatively, the polarizer 100 further comprises a protective layer 105 located between the optical film 101 and the polarization layer 102, wherein the first adhesive layer 104 is in direct contact with the protective layer 105.

[0116] In some embodiments, the first adhesive layer 104 is in direct contact with the optical film 101, and the first adhesive layer 104 is in direct contact with the polarization layer 102. Alternatively, the first adhesive layer 104 is in direct contact with the optical film 101, and the first adhesive layer 104 is in direct contact with the protective layer 105.

[0117] In some embodiments, it is contemplated that the first adhesive layer 104 may be selected from at least one of water-based adhesive, pressure-sensitive adhesive, and UV adhesive, wherein the material of the water-based adhesive may be selected from polyvinyl alcohol, wherein the material of the pressure-sensitive adhesive may be selected from acrylate copolymers, and wherein the material of the UV adhesive may be selected from multifunctional acrylate monomers.

[0118] With reference to Fig. 4 to Fig.6, in some embodiments, the second optical functional layer 103 comprises at least one of a transparent cured sublayer 107, a low-refractive index sublayer 108, an anti-reflective sublayer, an anti-fingerprint sublayer, and an antistatic sublayer. When the second optical functional layer 103 is a low-refractive index sublayer 108, the low-refractive index sublayer 108 may be formed by stacking a transparent cured subsection 108a and a low-refractive index subsection 108b.

[0119] In some embodiments, the polarizing layer 102 is made of polyvinyl alcohol and dyes.

[0120] In some embodiments, the polarizer 100 further comprises a separation layer 109 located on a side of the polarizing layer 102 remote from the optical film 101, wherein the separation layer 109 and the polarizing layer 102 are bonded together by a second adhesive layer 110. When the polarizer 100 is used in a display device, the separation layer 109 is removed to expose the second adhesive layer 110, so that the polarizer 100 adheres to a display panel via the second adhesive layer 110.

[0121] In some embodiments, the polarizer 100 further comprises a compensation layer 111 located between the second adhesive layer 110 and the polarization layer 102.

[0122] In the present embodiment of the present invention, the arrangement of the optical film 101 prevents optical defects such as moiré or white spots caused by the polarizer 100, and at the same time, the viewing angle of chromaticity and the contrast of a display device having the polarizer 100 are improved.

[0123] With reference to Fig. 8, an embodiment of the present invention further provides a display device 10 comprising a polarizer 100 as described above.

[0124] In particular, the display device comprises a display panel 200 and a first polarizer 300. The first polarizer 300 is located on a light-exit side of the display panel 200. The first polarizer 300 is selected from the polarizers 100 described above.

[0125] In some embodiments, the display panel 200 may be a liquid crystal display panel, a self-luminous display panel, etc. The self-luminous display panel may be an OLED (Organic Light-Emitting Diode) display panel, etc.

[0126] In some embodiments, the optical film 101 in the first polarizer 300 is located on a side of the polarizing layer 102 in the first polarizer 300 remote from the display panel.

[0127] If the display panel 200 is a liquid crystal display panel, the display device 10 further includes a backlight module 400 located on a side of the display panel 200 remote from the first polarizer 300, wherein the backlight module 400 is used to provide a light source for the display panel 200. The display device 10 also includes a second polarizer 500 located between the backlight module 400 and the display panel 200. The second polarizer 500 may be selected from the polarizers 100 described above, or the second polarizer 500 may not be selected from the polarizers 100 described above.

[0128] The present invention will now be described in more detail with reference to some examples. However, it should be noted that these examples are for illustrative purposes only and should not be construed as limiting the present invention. Example 1

[0129] In the present example, the material of the base material is an unmodified polyethylene terephthalate, wherein the adjusting particles in the base material are spherical silica, wherein the base material, after being mixed with the adjusting particles, is stretched in the MD (moving direction) and TD (transfer direction) directions (the stretching ratio MD x TD is 5 x 3) to form an optical film 1 having a thickness of 60 µm, wherein a mass fraction of the adjusting particles in the first optical film 1 is 0.05%. Example 2

[0130] The present example is the same as or similar to Example 1, except that the mass fraction of the adjusting particles in a formed optical film 2 is 0.1%. Example 3

[0131] The present example is the same as or similar to Example 1, except that the mass fraction of the adjusting particles in a formed optical film 3 is 0.2%. Example 4

[0132] The present example is similar to Example 1, except that the mass fraction of the adjusting particles in a formed optical film 4 is 0.5%. Example 5

[0133] The present example is similar to Example 1, except that the mass fraction of the adjusting particles in a formed optical film 5 is 0.8%. Example 6

[0134] The present example is similar to Example 1, except that the mass fraction of the adjusting particles in a formed optical film 6 is 1%. Example 7

[0135] The present example is similar to Example 4, except that the thickness of an optical film 7 is 55 µm. Example 8

[0136] The present example is similar to Example 4 except that the adjusting particle is a rod-shaped silicon dioxide to form an optical film 8. Example 9

[0137] The present example is similar to Example 4 except that the adjusting particles are formed by mixing rod-shaped silica, spherical silica, cubic silica in a mass ratio of 2:6:2 to form an optical film 9. Example 10

[0138] In the present example, the material of the base material is an unmodified polymethyl methacrylate, wherein the adjusting particles in the base material are spherical polystyrene, wherein the base material and the adjusting particles are mixed to form an optical film 10 with a thickness of 40 µm, wherein the mass fraction of the adjusting particles in the optical film 10 is 0.02%. Example 11

[0139] The present example is similar to Example 10 except that the adjusting particles are rod-shaped polystyrene, forming an optical film 11, wherein the mass fraction of the adjusting particles in the optical film 11 is 0.05%. Example 12

[0140] The present example is similar to Example 10, except that the adjusting particles are formed by mixing rod-shaped polystyrene, spherical polystyrene, cubic polystyrene in a mass ratio of 2:6:2 to form an optical film 12, wherein the mass fraction of the adjusting particles in the optical film 12 is 0.5%. Example 13

[0141] In the present example, the material of the base material is an unmodified polycarbonate, wherein the adjusting particles in the base material are spherical polystyrene, wherein the base material and the adjusting particles are mixed to form an optical film 12 with a thickness of 50 µm, wherein the mass fraction of the adjusting particles in the optical film 13 is 0.2%. Example 14

[0142] The present example is similar to Example 13 except that the adjusting particle is a rod-shaped polystyrene to form an optical film 14. Example 15

[0143] The present example is similar to Example 13 except that the adjusting particles are formed by mixing rod-shaped polystyrene, spherical polystyrene, cubic polystyrene in a mass ratio of 2:6:2 to form an optical film 15. Example 16

[0144] The present example is similar to Example 11, except that the base material and the adjusting particles are mixed to form an optical film 16 having a thickness of 80 µm, wherein the mass fraction of the adjusting particles in the optical film 16 is 0.03%. Example 17

[0145] The present example is similar to Example 16, except that the mass fraction of the adjusting particles in an optical film 17 is 0.015%. Example 18

[0146] The present example is similar to Example 16, except that the mass fraction of the adjusting particles in an optical film 18 is 0.005%. Example 19

[0147] The present example is similar to Example 16, except that the mass fraction of the adjusting particles in an optical film 19 is 0.003%. Example 20

[0148] The present example is similar to Example 16, except that the mass fraction of the adjusting particles in an optical film 20 is 0.001%. Comparison example 1

[0149] The present comparative example is similar to Example 1, except that no adjusting particle is present to form a comparative optical film 1.

[0150] The optical films obtained in Examples 1 to 15 and the comparative optical film obtained in Comparative Example 1 were measured using Shintech's Optipro-micro phase retardation meter to obtain their respective in-plane retardation values. The results are shown in Table 1.

[0151] The light scattering films obtained in Examples 1 to 15 and the comparative optical film obtained in Comparative Example 1 were each placed on a polarizer side remote from the display panel, with the polarizer attached to the surface of a 75-inch liquid crystal display panel, to observe the rainbow pattern when viewed from the front and side. The results are shown in Table 1. Among them, the observation results include "more obvious rainbow pattern," "obvious rainbow pattern," "slight rainbow pattern," and "unobvious rainbow pattern," which means that the obvious degree of the observed rainbow pattern decreases in order; a further observation result of "no rainbow pattern" means that no rainbow pattern phenomenon can be observed.The polarizer to be tested comprises a compensation layer, a polarizing layer, a protective layer, a light scattering film (or an optical reference film), and a transparent, cured underlayer, which are stacked sequentially.

[0152] The light-diffusing films obtained in Examples 4 to 8 were each placed on the side of the polarizer far from the display panel, with the polarizer attached to the surface of the 75-inch liquid crystal display panel to further test the optical performance. The results are shown in Table 2. The polarizer to be tested comprises a compensation layer, a polarizing layer, a protective layer, a light-diffusing film (or an optical reference film), and a transparent cured underlayer, which are stacked sequentially.

[0153] The viewing angle of brightness is a value corresponding to the side viewing angle when the brightness of the side viewing angle is half of the brightness of the front viewing angle.

[0154] The viewing angle measurement of chromaticity is a viewing angle measurement based on the CESI standard (CESI0.03). Table 1 Delay value in the plane (nm) Rainbow pattern phenomenon Optical Film 1 14 No rainbow pattern Optical Film 2 17 No rainbow pattern Optical Film 3 6 No rainbow pattern Optical Film 4 52 No rainbow pattern Optical Film 5 120 No rainbow pattern Optical Film 6 8 No rainbow pattern Optical Film 7 21 No rainbow pattern Optical Film 8 95 No rainbow pattern Optical Film 9 65 No rainbow pattern Optical Film 10 3 No rainbow pattern Optical Film 11 20 No rainbow pattern Optical Film 12 5 No rainbow pattern Optical Film 13 4 No rainbow pattern Optical Film 14 15 No rainbow pattern Optical Film 15 11 No rainbow pattern Optical Film 16 200 No rainbow pattern Optical Film 17 500 Unobtrusive rainbow pattern Optical Film 18 700 Slight rainbow pattern Optical Film 19 1000 Slight rainbow pattern Optical Film 20 1375 Obvious rainbow pattern Optical comparison film 1 3000 More obvious rainbow pattern Table 2 Viewing angle of brightness ° Viewing angle of chromaticity ° Optical Film 4 72 93 Optical Film 8 74 112

[0155] From Table 1, it can be seen that by adding adjusting particles to the optical film, the in-plane retardation of the optical film is effectively reduced, and the problem of rainbow patterns is improved or even eliminated. At the same time, with regard to reducing the in-plane retardation of the optical film, spherical particles have the best effect in reducing the in-plane retardation of the optical film. Adjusting particles composed of a mixture of particles of different shapes are less effective in reducing the in-plane retardation of the optical film. And rod-shaped particles are even less effective in reducing the in-plane retardation of the optical film. In addition, the improvement of the problem of rainbow patterns of the optical film is more noticeable when the in-plane retardation is reduced to less than 1000 nm.And when the in-plane retardation value is less than or equal to 200 nm, the problem of rainbow patterns in the optical film is completely eliminated. Table 2 shows that rod-shaped particles perform better than spherical particles in adjusting the viewing angle of chromaticity and the viewing angle of brightness of the optical film.

[0156] Embodiments of the present invention disclose an optical film, a polarizer, and a display device. The optical film comprises a base material and adjusting particles dispersed in the base material, wherein the optical film has an in-plane retardation value, and wherein the in-plane retardation value of the optical film is less than 3000 nm. In the present invention, the in-plane retardation value of the optical film is reduced to less than 3000 nm by adding the adjusting particles to the base material of the optical film, so that the difference between the in-plane retardation value and the retardation value in the thickness direction of the optical film is reduced, thereby improving the problem of rainbow patterns caused by the optical film.

[0157] An optical film, a polarizer, and a display device according to embodiments of the present invention have been described in detail above. The principle and embodiments of the invention have been explained herein using concrete examples. Nevertheless, the above description of the embodiments merely serves to facilitate understanding of the inventive method and its core concept. Furthermore, those skilled in the art may modify the detailed embodiments and the scope of application according to the spirit of the invention. In summary, the content of the description should not be construed as limiting the invention.

Claims

[1] Optical film, characterized by that it includes: a base material; Adjusting particles dispersed in the base material; wherein the optical film has an in-plane retardation value, and wherein the in-plane retardation value of the optical film is less than 3000 nm. [2] Optical film according to claim 1, characterized by that the retardation value in the plane of the optical film is less than or equal to 1000 nm. [3] Optical film according to claim 2, characterized by that the retardation value in the plane of the optical film is less than or equal to 500 nm. [4] Optical film according to claim 3, characterized by that the retardation value in the plane of the optical film is less than or equal to 200 nm. [5] Optical film according to one of claims 1 to 4, characterized bythat the optical film has a retardation value in the thickness direction, wherein a ratio of the retardation value in the plane of the optical film to the retardation value in the thickness direction of the optical film is greater than 0.1, and wherein the ratio of the retardation value in the plane of the optical film to the retardation value in the thickness direction of the optical film is less than 2. [6] Optical film according to claim 1, characterized by that the adjusting particles comprise adjusting particles of a first type and / or adjusting particles of a second type; wherein the first type adjustment particle has a plurality of first cross sections, each of the first cross sections having a first circumscribed circle, wherein a ratio of a length of a long axis of the first type adjustment particle to a diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles is greater than or equal to 1, wherein the ratio of the length of the long axis of the first type adjustment particle to the diameter of the first circumscribed circle having the largest diameter among the plurality of first circumscribed circles is less than 5; wherein the second type adjustment particle has a plurality of second cross sections, each of the second cross sections having a second circumscribed circle, wherein a ratio of a length of a long axis of the second type adjustment particle to a diameter of the second circumscribed circle having the largest diameter among the plurality of second circumscribed circles is greater than or equal to 5, and wherein the ratio of the length of the long axis of the second type adjustment particle to the diameter of the second circumscribed circle having the largest diameter among the plurality of second circumscribed circles is less than or equal to 50. [7] Optical film according to claim 6, characterized bythat the first-type adjustment particle is selected from at least one of an adjustment particle of a first subtype, an adjustment particle of a second subtype, an adjustment particle of a third subtype, an adjustment particle of a fourth subtype, and an adjustment particle of a fifth subtype, which have different shapes; and that the second-type adjustment particle is selected from at least one of an adjustment particle of a sixth subtype, an adjustment particle of a seventh subtype, an adjustment particle of an eighth subtype, an adjustment particle of a ninth subtype, and an adjustment particle of a tenth subtype, which have different shapes; wherein, along an extension direction of a long axis of the first subtype adjusting particle, a diameter of a first circumscribed circle of a first cross section of the first subtype adjusting particle has a change value of less than or equal to 0.3 µm; wherein a first end of the second sub-type adjustment particle is connected to a second end of the second sub-type adjustment particle, wherein along a direction away from the second end of the second sub-type adjustment particle, a diameter of a first circumscribed circle of a first cross-section located at the first end of the second sub-type adjustment particle gradually decreases, wherein along a direction away from the first end of the second sub-type adjustment particle, a diameter of a first circumscribed circle of a first cross-section located at the second end of the second sub-type adjustment particle gradually decreases; wherein, along an extension direction of a long axis of the third subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section located in a central part of the third subtype adjustment particle has a change value of less than or equal to 1 µm, wherein, along a direction away from the central part of the third subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section located at a first end of the third subtype adjustment particle gradually decreases, and a diameter of a first circumscribed circle of a first cross section located at a second end of the third subtype adjustment particle has a change value of less than or equal to 1 µm; wherein, along an extension direction of a long axis of the fourth subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section located in a central part of the fourth subtype adjustment particle has a change value of less than or equal to 1 µm, wherein, along a direction away from the central part of the fourth subtype adjustment particle, a diameter of a first circumscribed circle of a first cross section located at a first end of the fourth subtype adjustment particle gradually decreases, and a diameter of a first circumscribed circle of a first cross section located at a second end of the fourth subtype adjustment particle gradually decreases; wherein a first end of the fifth subtype adjustment particle is connected to a second end of the fifth subtype adjustment particle, wherein a diameter of a first circumscribed circle of a first cross section of the fifth subtype adjustment particle gradually decreases along a direction from the first end of the fifth subtype adjustment particle to the second end of the fifth subtype adjustment particle; wherein, along an extension direction of a long axis of the adjusting particle of the sixth subtype, a diameter of a second circumscribed circle of a second cross section of the adjusting particle of the sixth subtype has a change value of less than or equal to 0.3 µm; wherein, along an extension direction of a long axis of the seventh subtype adjustment particle, a diameter of a second circumscribed circle of a second cross section located in a central part of the seventh subtype adjustment particle has a change value of less than or equal to 1 µm, wherein, along a direction away from the central part of the seventh subtype adjustment particle, a diameter of a second circumscribed circle of a second cross section located at a first end of the seventh subtype adjustment particle gradually decreases, and a diameter of a second circumscribed circle of a second cross section located at a second end of the seventh subtype adjustment particle has a change value of less than or equal to 1 µm; wherein, along an extension direction of a long axis of the eighth subtype adjustment particle, a diameter of a second circumscribed circle of a second cross section located in a central part of the eighth subtype adjustment particle has a change value of less than or equal to 1 µm, wherein, along a direction away from the central part of the eighth subtype adjustment particle, a diameter of a second circumscribed circle of a second cross section located at a first end of the eighth subtype adjustment particle gradually decreases, and a diameter of a second circumscribed circle of a second cross section located at a second end of the eighth subtype adjustment particle gradually decreases; wherein a first end of the ninth subtype adjustment particle is connected to a second end of the ninth subtype adjustment particle, wherein a diameter of a second circumscribed circle of a second cross section of the ninth subtype adjustment particle gradually decreases along a direction from the first end of the ninth subtype adjustment particle to the second end of the ninth subtype adjustment particle; wherein a first end of the adjustment particle of the tenth subtype is connected to a second end of the adjustment particle of the tenth subtype, wherein along a direction away from the second end of the adjustment particle of the tenth subtype, a diameter of a second circumscribed circle of a second cross-section located at the first end of the adjustment particle of the tenth subtype gradually decreases, and wherein along a direction away from the first end of the adjustment particle of the tenth subtype, a diameter of a second circumscribed circle of a second cross-section located at the second end of the adjustment particle of the tenth subtype gradually decreases. [8] Optical film according to claim 6, characterized bythat the adjusting particles comprise the adjusting particles of the first type and the adjusting particles of the second type, wherein a mass fraction of the adjusting particles of the first type in the adjusting particles is greater than 50% and a mass fraction of the adjusting particles of the second type in the adjusting particles is less than 50%. [9] Optical film according to claim 1, characterized by that the base material comprises a first sub-base material and / or a second sub-base material, wherein the first sub-base material is selected from at least one of unmodified polyester and unmodified cellulose acetate, wherein the second sub-base material is selected from at least one of modified polyester and modified cellulose acetate; wherein a mass fraction of the first sub-base material in the base material is greater than or equal to 65% and the mass fraction of the first sub-base material in the base material is less than or equal to 100%; and wherein a mass fraction of the second sub-base material in the base material is greater than or equal to 0% and the mass fraction of the second sub-base material in the base material is less than or equal to 35%. [10] Polarizer, characterized by that it comprises an optical 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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