Light diffusing film, polarizing sheet, and display panel

Abstract

SOLUTION: The present invention discloses a light diffusing film, a polarizing sheet and a display panel. The optical diffusion film includes a middle region and an edge region located on at least one side of the middle region, the optical diffusion film further includes a base material and diffusion particles, and the diffusion particles are distributed in the base material and located in the middle region and the edge region. Wherein the optical diffuser film includes a first included angle between a slow axis direction of the middle section and a first direction, the optical diffuser film includes a second included angle between a slow axis direction of the edge section and the first direction, a ratio of the first included angle to the second included angle is greater than or equal to 0.1 and less than or equal to 1.5, and the first direction is a machine direction of the optical diffuser film.EFFECT: The present invention enhances the effect of improving and enhancing the viewing angle of the optical diffusing film, and further enhances the action of light diffusion and viewing angle expansion of the optical diffusing film.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of display technology, and more particularly to a light diffusion film, a polarizing sheet, and a display panel. [Background technology]

[0002] Liquid crystal displays (LCDs) have high contrast and transmittance and are widely used in consumer electronic products such as televisions. However, the viewing angle of LCDs is inferior to that of self-luminous displays.

[0003] To solve the problem of small display viewing angles, LCD displays have always been designed internally, but this is costly, difficult, and has limited effect in improving the viewing angle. Alternatively, optical layers that expand the viewing angle can be added to the film layer on the polarizing sheet. For example, the optical layers can be made of alternating high refractive index materials and low refractive index materials to form a certain pattern, but the manufacturing process for the optical layers is complicated, the number of film pieces is large, the finished product is thick, the yield is low, and the cost is high. Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present invention provide a light diffusion film, a polarizing sheet, and a display panel, which can simplify the manufacturing process of the light diffusion film and enhance the viewing angle improving effect of the light diffusion film. [Means for solving the problem]

[0005] An embodiment of the present invention provides a light diffusing film, comprising a middle region and an edge region located on at least one side of the middle region, further comprising a substrate and diffusing particles distributed in the substrate and positioned in the middle region and the edge region, wherein the light diffusing film comprises a first included angle between a slow axis direction of the middle region and a first direction, a second included angle between a slow axis direction of the edge region and the first direction, a ratio of the first included angle to the second included angle being 0.1 or more and 1.5 or less, and the first direction is the machine direction of the light diffusing film.

[0006] In one embodiment of the present invention, the ratio of the first included angle to the second included angle is greater than or equal to 0.35 and less than or equal to 1.1.

[0007] In one embodiment of the present invention, the first included angle is greater than or equal to 40° and less than or equal to 90°, and the second included angle is greater than or equal to 70° and less than or equal to 110°.

[0008] In one embodiment of the present invention, the ratio of the first included angle to the second included angle is 1, and the first included angle and the second included angle are both 90°.

[0009] In one embodiment of the invention, the edge regions have a width along a direction away from the middle region of 15 cm or less.

[0010] In one embodiment of the present invention, the diffusion particle includes multiple cross sections, each of which includes one inscribed circle, and the ratio of the length of the major axis of the diffusion particle to the diameter of the inscribed circle with the largest diameter among the multiple inscribed circles is greater than or equal to 1 and less than or equal to 30.

[0011] In one embodiment of the present invention, the shape of the diffusing particles is selected from at least one of spherical particles, rod-shaped particles, needle-shaped particles, cone-shaped particles, oval-spherical particles, square-shaped particles, and rectangular-shaped particles.

[0012] In accordance with the above object of the present invention, an embodiment of the present invention provides a polarizing sheet, which includes a polarizing layer and the light diffusing film.

[0013] In one embodiment of the present invention, the light transmission axis direction of the polarizing layer is perpendicular to the first direction.

[0014] In one embodiment of the present invention, the polarizing sheet further includes a functional layer disposed on one side of the diffusion film away from the polarizing layer, and the functional layer includes at least one of a sub-transparent hardened layer, a sub-low-reflection layer, a sub-anti-reflection layer, a sub-anti-fingerprint layer, a sub-anti-static layer, and an explosion-proof film.

[0015] In accordance with the above object of the present invention, an embodiment of the present invention provides a display panel, which includes a panel body and a polarizing sheet, the polarizing sheet being disposed on a light-exiting side of the panel body. [Effects of the Invention]

[0016] In the present invention, by forming diffusing particles in a light diffusion film, the light diffusion film has the functions of diffusing light and widening the viewing angle, and by incorporating diffusing particles into a substrate to form the light diffusion film, it is possible to simplify the process, reduce costs, and increase the yield rate. In addition, in the present invention, by setting the ratio of the included angle between the slow axis direction of the light diffusion film and the first direction in the middle section and the edge section after incorporating diffusing particles, the effect of improving and enhancing the viewing angle of the light diffusion film is enhanced, and the light diffusion and viewing angle widening functions of the light diffusion film are further enhanced. [Brief explanation of the drawings]

[0017] The following detailed description of the specific implementation of the present invention, combined with the drawings, will make the technical solution and other beneficial effects of the present invention more apparent. [Figure 1] 1 is a structural diagram of a light diffusion film provided by an embodiment of the present invention; [Figure 2] 1 is a plan view of a light diffusion film according to an embodiment of the present invention; [Figure 3] 1 is a structural diagram of a polarizing sheet provided by an embodiment of the present invention; [Figure 4]1 is a structural diagram of a display panel provided by an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0018] The following clearly and completely describes the technical solutions of the embodiments of the present invention in conjunction with the drawings of the embodiments of the present invention. Of course, the described embodiments are only some of the embodiments of the present invention, and are not all of the embodiments. Based on the embodiments of the present invention, all other embodiments that can be obtained by those skilled in the art without any creative efforts fall within the scope of protection of the present invention.

[0019] The following disclosure provides many different implementations or examples for realizing different structures of the present invention. To simplify the disclosure of the present invention, specific example components and configurations will be described. Of course, these are merely examples and are not intended to limit the present invention. Also, the present invention may repeatedly refer to numbers and / or letters in different examples; this repetition is for purposes of simplicity and clarity and does not in itself indicate a relationship between the various implementations and / or configurations discussed. Also, while the present invention provides examples of various specific processes and materials, those skilled in the art may recognize the application of other processes and / or the use of other materials.

[0020] 1 and 2, an embodiment of the present invention provides a light diffusion film 10. The light diffusion film 10 includes a middle region 101 and an edge region 102 located on at least one side of the middle region 101.

[0021] The light diffusing film 10 further includes a substrate 11 and diffusing particles 12 distributed in the substrate 11 and located in a middle region 101 and an edge region 102 .

[0022] Furthermore, the light diffusion film 10 includes a first included angle between the slow axis direction of the middle region 101 and the first direction, and the light diffusion film 10 includes a second included angle between the slow axis direction of the edge region 102 and the first direction, the ratio of the first included angle to the second included angle being greater than or equal to 0.1 and less than or equal to 1.5, and the first direction is the machine direction of the light diffusion film.

[0023] The first direction is the machine direction (MD) of the light diffusion film 10 in the stretching process, and can also be regarded as the longitudinal direction or the stretching direction of the equipment.

[0024] In the embodiment of the present invention, the light diffusion film 10 is formed with diffusing particles 12, which allows the light diffusion film 10 to diffuse light and expand the viewing angle. Furthermore, by incorporating the diffusing particles 12 into the substrate 11 to form the light diffusion film 10, the process can be simplified, costs can be reduced, and the yield rate can be increased. Furthermore, in the embodiment of the present invention, the ratio of the included angle between the slow axis direction of the light diffusion film 10 and the first direction after the diffusing particles 12 are incorporated in the middle region 101 and the edge region 102 is set to enhance the effect of improving and enhancing the viewing angle of the light diffusion film 10, further enhancing the light diffusion and viewing angle expanding effects of the light diffusion film 10.

[0025] 1 and 2, the light diffusion film 10 provided by the embodiment of the present invention includes a substrate 11 and diffusion particles 12 distributed in the substrate 11. The diffusion particles 12 increase the viewing angle of the light diffusion film 10 by utilizing the refraction of light.

[0026] Here, the light diffusion film 10 includes a middle region 101 and an edge region 102 surrounding the middle region 101, and the edge region 102 is located on the peripheral side of the middle region 101. The diffusion particles 12 are distributed in the middle region 101 and the edge region 102, thereby diffusing light and widening the viewing angle in both the middle region 101 and the edge region 102 of the light diffusion film 10.

[0027] In one embodiment, the shape of the diffusion particles 12 is selected from at least one of spherical particles, rod-shaped particles, needle-shaped particles, cone-shaped particles, oval-spherical particles, square particles, and rectangular particles. That is, a plurality of diffusion particles 12 are distributed in the substrate 11, and each diffusion particle 12 can be independently selected from one of spherical particles, rod-shaped particles, needle-shaped particles, cone-shaped particles, oval-spherical particles, square particles, and rectangular particles. Furthermore, the needle-shaped particles may be needle-shaped particles tapered at one end or needle-shaped particles tapered at both ends, and the cone-shaped particles may be long cone-shaped particles or double cone-shaped particles.

[0028] In one embodiment, the cross-sectional shape of the diffusing particles 12 may include regular or irregular shapes such as circles, ellipses, triangles, squares, etc.

[0029] In one embodiment, the material of the diffusing particles 12 may be at least one of an inorganic material, an organic material, or a composite material, for example, the material of the diffusing particles 12 may include at least one of polysiloxane, polymethyl methacrylate, polystyrene, silica, titanium oxide, zirconium dioxide, silicon carbide, silicon nitride, zinc oxide, magnesium oxide, aluminum oxide, calcium sulfate, calcium carbonate, potassium titanate, and aluminum borate.

[0030] In one embodiment, the diffusing particles 12 can be surface-modified to promote the dispersibility of the diffusing particles 12 in the substrate 11 or to enhance the functionality, such as toughness, of the diffusing particles 12. When the diffusing particles 12 are surface-modified, the surface of the diffusing particles 12 is modified with at least one of inorganic cations, inorganic anions, polymers, coupling agents, or surfactants. That is, the surface of the diffusing particles 12 includes at least one of inorganic cation groups, inorganic anion groups, polymer groups, coupling agent groups, or surfactant groups.

[0031] The surfaces of the diffusion particles 12 are modified with at least one selected from the group consisting of magnesium chloride, calcium chloride, barium chloride, strontium chloride, stearic acid, sodium stearate, zinc octadecanoate, sulfonic acid surfactants, thio surfactants, titanate esters, aluminum esters, polyacrylamides, silanes, alkyl phosphates, aryl phosphates, alkyl phosphates, aryl phosphates, alkyl alcohol amide phosphates, alkyl alcohol amide phosphates, imidazoline phosphates, imidazoline phosphates, high polyphosphates, high polyphosphates, and silicone phosphates. Preferably, the surfaces of the diffusion particles 12 are modified with at least one sulfonic acid surfactant or thio surfactant. The sulfonic acid surfactant is at least one selected from the group consisting of alkyl sulfonates and fluoroalkyl sulfonates, specifically, at least one selected from the group consisting of sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, and sodium fluorododecyl sulfonate. The thio surfactant is at least one selected from the group consisting of thiols and fluorothiols, specifically, for example, at least one selected from the group consisting of octylthiol, dodecylthiol, tetradecylthiol, octadecylthiol, fluorooctylthiol, and fluorododecylthiol. After mixing the sulfonic acid surfactant with the surface-modified diffusion particles 12, the sulfonic acid surfactant forms a sulfonic acid group shell layer, such as a benzene ring sulfonic acid group shell layer, on the surface of the whiskers, protecting the diffusion particles 12 and improving the toughness of the diffusion particles 12, thereby reducing breakage of the diffusion particles 12 at the substrate 11. After the thio surfactant group is mixed with the surface-modified diffusion particles 12, the thio surfactant group and the hydroxyl groups on the whisker surface form a cross-linked network of OSO, and the binding energy of OSO is relatively large, which protects the diffusion particles 12 during the process of the diffusion particles 12 and the material of the substrate 11 being mixed to form the diffusion particles 12, contributes to reducing the breakage of the diffusion particles 12, and enhances the effect of the diffusion particles 12 in improving optical functions such as contrast and brightness.More preferably, the diffusion particles 12 are modified with at least one of a fluorine-substituted sulfonic acid surfactant and a fluorine-substituted thio surfactant, specifically, for example, with at least one of sodium fluorododecylsulfonate, fluorooctylthiol, and fluorothiol, in which the fluorine atoms have high stability in the alkyl chain, the bond energy of the carbon-fluorine bond is higher than the bond energy of the carbon-carbon bond, and the carbon-fluorine bond has a shielding effect on the carbon-carbon bond, contributing to the protection of the carbon-carbon bond and thereby improving the stability of the diffusion particles 12.

[0032] Furthermore, the diffusing particle 12 includes multiple cross sections, each cross section including an inscribed circle, the diameter of the inscribed circle being 1 nm or more and 12.4 nm or less, preferably the diameter of the inscribed circle being 1 nm or more and 5 nm or less, and more preferably the diameter of the inscribed circle being 1.5 nm or more and 4 nm or less.

[0033] In one embodiment, the ratio of the length of the major axis of the diffusion particle 12 to the diameter of the inscribed circle with the largest diameter among the multiple inscribed circles is greater than or equal to 1 and less than or equal to 30, for example, the ratio may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, etc., and the above ratios are merely examples and are not limited thereto.

[0034] In one embodiment, the material of the substrate 11 may be a crystalline material or an amorphous material, and may specifically include at least one of modified or unmodified polyester, modified or unmodified cellulose acetate.

[0035] In one embodiment, the modified or unmodified polyester may include 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 include modified or unmodified cellulose triacetate.

[0036] In one embodiment, the mass fraction content of the diffusion particles 12 in the substrate 11 is 0.001% or more and 10% or less, preferably, the mass fraction content of the diffusion particles 12 in the substrate 11 is 1% or more and 6% or less, for example, the mass fraction content of the diffusion particles 12 in the substrate 11 may be 1%, 2%, 3%, 4%, 5%, or 6%, etc., the above values ​​are merely examples and are not limited thereto.

[0037] In one embodiment, the edge regions 102 are no wider than 15 centimeters in the direction away from the intermediate region 101 .

[0038] In the embodiment of the present invention, in order to control the direction of the slow axis in different regions of the light diffusion film 10, the diffusion particles 12 are distributed on the substrate 11, where the slow axis direction is the direction in which light propagates slowly.

[0039] In an embodiment of the present invention, the light diffusion film 10 includes a first included angle between the slow axis direction in the middle region 101 and a first direction, the light diffusion film 10 includes a second included angle between the slow axis direction in the edge region 102 and the first direction, and the ratio of the first included angle to the second included angle is greater than or equal to 0.1 and less than or equal to 1.5.

[0040] In the embodiment of the present invention, the first direction may be the machine direction (MD) of the light diffusing film 10 in the stretching process, which can also be regarded as the longitudinal direction or the stretching direction of the equipment.

[0041] In one embodiment, the ratio of the first included angle to the second included angle may be equal to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, or 1.5, etc., and the above ratios are by way of example only and are not limiting.

[0042] The present invention provides Examples 1 to 4 to test the performance of the light diffusion film provided by the present invention.

[0043] In Example 1, the diffusing particles 12 are added to polymethyl methacrylate, and the material of the diffusing particles 12 may include polystyrene. The mixture is uniformly stirred, and the mixed material is fed into an extrusion device and extruded and stretched to form a film, thereby forming the light diffusing film 10. Here, the diffusing particles 12 are spherical particles, and the mass content of the diffusing particles 12 in the light diffusing film 10 is 0.5%.

[0044] In Example 2, diffusing particles 12 are added to polymethyl methacrylate, and the material of the diffusing particles 12 may include calcium carbonate. The mixture is uniformly stirred, and the mixed material is fed into an extrusion device and extruded and stretched to form a film, thereby forming a light diffusing film 10. Here, the diffusing particles 12 are rod-shaped particles, and the mass content of the diffusing particles 12 in the light diffusing film 10 is 1%. In Example 2, the first included angle is 40°, and the second included angle is 101°.

[0045] In Example 3, the diffusing particles 12 are added to polyethylene terephthalate (the material of the diffusing particles 12 may include polystyrene), and the mixture is stirred uniformly. The mixed material is then fed into an extrusion device and extruded and stretched to form a film, forming a light diffusing film 10. Here, the diffusing particles 12 are spherical particles, and the mass content of the diffusing particles 12 in the light diffusing film 10 is 0.5%. In Example 3, the first included angle is 78°, and the second included angle is 73°.

[0046] In Example 4, diffusing particles 12 are added to polymethyl methacrylate, and the material of the diffusing particles 12 may include calcium carbonate. The mixture is uniformly stirred, and the mixed material is fed into an extrusion device and extruded and stretched to form a film, thereby forming a light diffusing film 10. Here, the diffusing particles 12 are rod-shaped particles, and the mass content of the diffusing particles 12 in the light diffusing film 10 is 3%. In Example 4, the first included angle is 90°, and the second included angle is 90°.

[0047] Next, the chromaticity viewing angle index (CESI), film tensile strength, and film breaking elongation were measured for the light diffusion films 10 obtained in Examples 1 to 4, and the results shown in Table 1 below were obtained. TIFF2026002719000002.tif52159

[0048] Here, CESI indicates the viewing angle range within which the difference between the chromaticity and the viewing angle is within 0.03. In Example 1, the spherical particles are isotropic, but the polymethyl methacrylate is an amorphous material. Therefore, the speed of light propagation in the light diffusion film 10 formed in Example 1 is relatively uniform and essentially the same in the middle region 101 and the edge region 102. Therefore, the ratio of the first included angle to the second included angle in Example 1 can be set to 1. Furthermore, as can be seen from the above examples, the ratio of the first included angle to the second included angle is preferably 0.35 or more and 1.1 or less. In this case, the CESI viewing angles of the resulting light diffusion film 10 are all 84° or more.

[0049] In one embodiment, the first included angle is 40° or more and 90° or less, and the second included angle is 70° or more and 110° or less. Because the diffusion particles 12 are mixed into the substrate 11 and then stretched to form a film, the arrangement of the diffusion particles 12 in the intermediate region 101 and the edge region 102 is different due to process limitations. Furthermore, the included angle between the slow axis direction and the first direction in the intermediate region 101 is mostly small, while the included angle between the slow axis direction and the first direction in the edge region 102 is mostly large. As a result, the ratio of the first included angle to the second included angle tends to be less than 1. That is, the ratio of the first included angle to the second included angle is often less than 1.

[0050] When the ratio of the first included angle to the second included angle is less than 1, the CESI viewing angle of the light diffuser film 10 increases as the ratio of the first included angle to the second included angle increases. When the ratio of the first included angle to the second included angle is greater than 1, the CESI viewing angle of the light diffuser film 10 decreases as the ratio of the first included angle to the second included angle increases. When the ratio of the first included angle to the second included angle is equal to 1, the CESI viewing angle of the light diffuser film 10 is maximized. Therefore, in this embodiment of the present invention, the ratio of the first included angle to the second included angle is preferably equal to 1, and both the first included angle and the second included angle are equal to 90°.

[0051] In one embodiment, the tensile strength of the light diffusion film 10 is 20 MPa or more and 5000 MPa or less, for example, the tensile strength of the light diffusion film 10 may be equal to 20 MPa, 100 MPa, 100 MPa, 500 MPa, 1000 MPa, 1500 MPa, 2000 MPa, 2500 MPa, 3000 MPa, 3500 MPa, 4000 MPa, 4500 MPa, or 5000 MPa, etc., and the above numerical values ​​are merely examples and are not limited thereto.

[0052] In one embodiment, the breaking elongation of the light diffusion film 10 is greater than or equal to 3% and less than or equal to 300%, for example, the breaking elongation of the light diffusion film 10 may be equal to 3%, 10%, 50%, 100%, 110%, 150%, 200%, 250%, or 300%, etc., the above values ​​being merely examples and not limited thereto.

[0053] As described above, in the embodiment of the present invention, the diffusion particles 12 are formed in the light diffusion film 10, so that the light diffusion film 10 has the functions of diffusing light and widening the viewing angle. Furthermore, by incorporating the diffusion particles 12 into the substrate 11 to form the light diffusion film 10, the process can be simplified, costs can be reduced, and the yield rate can be increased. Furthermore, in the embodiment of the present invention, the ratio of the included angle between the slow axis direction of the light diffusion film 10 and the first direction after the diffusion particles 12 are incorporated in the middle region 101 and the edge region 102 is set to enhance the effect of improving and enhancing the viewing angle of the light diffusion film 10, further enhancing the light diffusion and viewing angle widening functions of the light diffusion film 10.

[0054] 1 and 3, the polarizing sheet 20 includes a polarizing layer 21 and the light diffusing film 10 described in the above embodiment, and the light diffusing film 10 is disposed on one side of the polarizing layer 21.

[0055] In one embodiment, the polarizing sheet 20 further includes a first adhesive layer 22 disposed between the polarizing layer 21 and the light diffusion film 10, and the polarizing layer 21 is bonded to the light diffusion film 10 via the first adhesive layer 22.

[0056] In one embodiment, the polarizing sheet 20 further includes a second adhesive layer 23 and a release film 24 disposed on the side of the light diffusion film 10 facing away from the polarizing layer 21, and the release film 24 is attached to the side of the polarizing layer 21 facing away from the light diffusion film 10 via the second adhesive layer 23. It is understood that the release film 24 may be removed during subsequent use of the polarizing sheet 20, and the polarizing sheet 20 can be attached to a display panel or other equipment via the second adhesive layer 23.

[0057] In one embodiment, the polarizing sheet 20 further includes a functional layer 25 disposed on the side of the light diffusion film 10 away from the polarizing layer 21. For example, the functional layer 25 may include at least one of a sub-transparent hardened layer, a sub-low-reflection layer, a sub-anti-reflection layer, a sub-anti-fingerprint layer, a sub-anti-static layer, and an explosion-proof film. When the functional layer 25 is a sub-low-reflection layer, the sub-low-reflection layer may be formed by laminating a transparent hardened layer and a low-refractive layer.

[0058] In one embodiment, the polarizing layer 21 may be composed of polyvinyl alcohol and a dye.

[0059] In an embodiment of the present invention, by adding a light diffusion film 10 to a polarizing sheet 20, optical defects such as moire and white spots caused by the polarizing sheet 20 can be avoided, and the chromaticity viewing angle and contrast can be improved when a display device equipped with the polarizing sheet 20 is used.

[0060] In one embodiment, the light transmission axis direction of the polarizing layer 21 is aligned with the second direction, which is perpendicular to the machine direction (transverse direction, TD) and can also be considered as the horizontal direction, i.e., perpendicular to the first direction. When the angle between the slow axis direction of the light diffuser 10 and the first direction is 90°, light is polarized along the first direction after passing through the polarizing layer 21. When the polarized light is then irradiated onto the light diffuser 10, the slow axis direction of the light diffuser 10 is perpendicular to the first direction, which further scatters the light. This further improves the viewing angle of a display panel equipped with the polarizing sheet 20 of the present embodiment and enhances the display effect of the display panel.

[0061] 1, 3 and 4, an embodiment of the present invention further provides a display panel 30, which includes a panel body 31 and a polarizing sheet 20, and the polarizing sheet 20 is disposed on the light-emitting side of the panel body 31. It can be understood that the release film 24 of the polarizing sheet 20 shown in FIG. 3 is removed, and the remaining film layer of the polarizing sheet 20 is attached to the surface of the panel body 31 using the second adhesive layer 23.

[0062] Here, the polarizing sheet 20 is the polarizing sheet 20 described in the previous embodiment, and the light diffusing film 10 is located on one side of the polarizing layer 21 that is farther away from the panel body 31 .

[0063] As described above, in the embodiment of the present invention, the light diffusion film 10 is formed with the diffusing particles 12, thereby enabling the light diffusion film 10 to diffuse light and expand the viewing angle. Furthermore, by incorporating the diffusing particles 12 into the substrate 11 to form the light diffusion film 10, the process is simplified, costs are reduced, and the yield rate is increased. Furthermore, in the embodiment of the present invention, the ratio of the included angle between the slow axis direction and the first direction of the light diffusion film 10 after incorporating the diffusing particles 12 in the middle region 101 and the edge region 102 is adjusted to enhance the viewing angle improvement effect of the light diffusion film 10, further enhancing the light diffusion and viewing angle expansion effects of the light diffusion film 10. Furthermore, when the polarizing sheet 20 having the light diffusion film 10 is attached to the light exit side of the panel body 31, the viewing angle and display effect of the display panel 30 can be effectively improved.

[0064] In the above embodiments, the description of each embodiment has different emphasis, and for the parts not described in detail in one embodiment, reference can be made to the relevant descriptions of other embodiments.

[0065] The above has described in detail the light diffusion film, polarizing sheet, and display panel provided by the embodiments of the present invention. Specific examples are used to illustrate the principles and implementation of the present invention. The above description of the embodiments is intended to help understand the technical solutions of the present invention and their core ideas. Those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified or some technical features therein may be replaced with equivalents. However, such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A light diffusion film, The light diffusion film includes a middle section and an edge section located on at least one side of the middle section, the light diffusion film further comprises a substrate; and diffusion particles distributed in the substrate and located in the intermediate region and the edge region; the light diffusion film includes a first included angle between the slow axis direction of the middle region and a first direction, the light diffusion film includes a second included angle between the slow axis direction of the edge region and the first direction, the ratio of the first included angle to the second included angle is 0.1 or more and 1.5 or less, and the first direction is the machine direction of the light diffusion film; A light diffusion film characterized by:

2. a ratio of the first included angle to the second included angle is greater than or equal to 0.35 and less than or equal to 1.1; 2. The light diffusion film according to claim 1.

3. the first included angle is greater than or equal to 40° and less than or equal to 90°, and the second included angle is greater than or equal to 70° and less than or equal to 110°; 2. The light diffusion film according to claim 1.

4. the ratio of the first included angle to the second included angle is 1, and the first included angle and the second included angle are both 90°; 4. The light diffusing film according to claim 1, wherein the light diffusing film is a film having a thickness of 100 nm or less.

5. the edge regions have a width in a direction away from the intermediate region of 15 cm or less; 2. The light diffusion film according to claim 1.

6. The diffusion particle includes a plurality of cross sections, each of the cross sections includes one inscribed circle, and the ratio of the length of the major axis of the diffusion particle to the diameter of the inscribed circle with the largest diameter among the plurality of inscribed circles is 1 or more and 30 or less.

2. The light diffusion film according to claim 1.

7. The shape of the diffusion particles is selected from at least one of spherical particles, rod-shaped particles, needle-shaped particles, cone-shaped particles, oval-spherical particles, square-shaped particles, and rectangular particles.

2. The light diffusion film according to claim 1.

8. A polarizing sheet, The polarizing sheet includes a polarizing layer and the light diffusing film according to any one of claims 1 to 3. A polarizing sheet characterized by:

9. the light transmission axis direction of the polarizing layer is perpendicular to the first direction; 9. The polarizing sheet according to claim 8.

10. The polarizing sheet further includes a functional layer disposed on one side of the diffusion film away from the polarizing layer, and the functional layer includes at least one of a sub-transparent hardened layer, a sub-low-reflection layer, a sub-anti-reflection layer, a sub-anti-fingerprint layer, a sub-anti-static layer, and an explosion-proof film; 9. The polarizing sheet according to claim 8.

11. A display panel, the display panel includes a panel body and the polarizing sheet according to claim 8, the polarizing sheet being disposed on the light exit side of the panel body; A display panel characterized by:

Images