Polarizer and display device

Abstract

Embodiments of the invention disclose a polarizer and a display device. The polarizer comprises a polarizing layer and a first optical functional layer located on one side of the polarizing layer. The first optical functional layer comprises a substrate and light diffusion particles dispersed in the substrate. The absolute value of the angular difference between the orthogonal projection of the longitudinal axis of the light diffusion particles in the first plane and the orthogonal projection of the absorption axis of the polarizing layer in the first plane is less than or equal to 5°.

Description

Polarizer and display device Technical Field

[0001] The present invention relates to the field of display, and in particular to a polarizer and a display device. Background Art

[0002] Currently, to expand the viewing angle of a display device, an optical film is typically placed on the outermost edge of the polarizer. Existing optical films for expanding viewing angle require adding a corresponding film layer to the polarizer, which increases the thickness of the polarizer, reduces the light output from the display device, and degrades the display contrast.

[0003] Therefore, there is an urgent need for a polarizer and a display device to solve the above technical problems. SUMMARY OF THE INVENTION

[0004] The present invention provides a polarizer and a display device, which can alleviate the current technical problem of degradation of the display contrast of a display device due to adding a film layer in the polarizer to reduce the outgoing light of the display device.

[0005] To solve the above problems, the technical solutions provided by this application are as follows:

[0006] The present invention provides a polarizer, comprising:

[0007] Polarizing layer;

[0008] A first optical functional layer is located on one side of the polarizing layer, and the first optical functional layer includes a substrate and light diffusion particles dispersed in the substrate;

[0009] wherein the substrate has a glass transition temperature of 30° C. to 500° C., and the substrate has an elastic modulus of 500 MPa to 5000 MPa at 23° C.;

[0010] The orthographic projection of the long axis of the light diffusion particle in the first plane has a first orientation angle, the orthographic projection of the absorption axis of the polarizing layer in the first plane has a second orientation angle, the average of the difference between the first orientation angle and the second orientation angle is less than or equal to 5°, and the first plane is parallel to the plane where the polarizing layer is located.

[0011] Preferably, there is an angle between the long axis of the light diffusion particle and the first plane, the angle is an acute angle, and the angle is less than or equal to 40°.

[0012] Preferably, the light diffusion particles are selected from at least one of the first type of light diffusion particles, the second type of light diffusion particles, the third type of light diffusion particles, the fourth type of light diffusion particles, and the fifth type of light diffusion particles;

[0013] Wherein, along the extension direction of the long axis of the first type of light diffusion particles, the change value of the diameter of the first type of light diffusion particles is less than or equal to 0.3 microns;

[0014] Along the extension direction of the long axis of the second type light diffusing particle, the change value of the diameter of the middle portion of the second type light diffusing particle is less than or equal to 1 micron, and in the direction away from the middle portion of the second type light diffusing particle, the diameter of the first end portion of the second type light diffusing particle gradually decreases, and the change value of the diameter of the second end portion of the second type light diffusing particle is less than or equal to 1 micron;

[0015] Along the extension direction of the long axis of the third type light diffusing particle, the change value of the diameter of the middle portion of the third type light diffusing particle is less than or equal to 1 micron, and in the direction away from the middle portion of the third type light diffusing particle, the diameter of the first end portion of the third type light diffusing particle gradually decreases, and the diameter of the second end portion of the third type light diffusing particle gradually decreases;

[0016] The first end of the fourth type of light diffusing particle is connected to the second end of the fourth type of light diffusing particle in sequence, and the diameter of the fourth type of light diffusing particle gradually decreases along the direction from the first end of the fourth type of light diffusing particle to the second end of the fourth type of light diffusing particle;

[0017] The first end of the fifth type of light diffusion particle is connected in sequence with the second end of the fifth type of light diffusion particle. The diameter of the first end of the fifth type of light diffusion particle gradually decreases in the direction away from the second end of the fifth type of light diffusion particle, and the diameter of the second end of the fifth type of light diffusion particle gradually decreases in the direction away from the first end of the fifth type of light diffusion particle.

[0018] Preferably, the first type of light diffusion particles are rod-shaped particles, the second type of light diffusion particles are needle-shaped particles with a reduced diameter at one end, the third type of light diffusion particles are needle-shaped particles with reduced diameters at both ends, the fourth type of light diffusion particles are long cone-shaped particles, and the fifth type of light diffusion particles are biconical particles.

[0019] Preferably, the light diffusion particles are selected from at least two of the first type of light diffusion particles, the second type of light diffusion particles, the third type of light diffusion particles, the fourth type of light diffusion particles, and the fifth type of light diffusion particles.

[0020] Preferably, the light diffusion particles are selected from the group consisting of first type light diffusion particles, second type light diffusion particles and third type light diffusion particles.

[0021] Preferably, the light diffusion particles are selected from the first type of light diffusion particles, the fourth type of light diffusion particles, and the fifth type of light diffusion particles.

[0022] Preferably, the light diffusion particles are selected from the first type of light diffusion particles, the second type of light diffusion particles, the third type of light diffusion particles, the fourth type of light diffusion particles, and the fifth type of light diffusion particles.

[0023] Preferably, the mass fraction of the first type of light diffusion particles in the light diffusion particles is 1% to 8%, the mass fraction of the second type of light diffusion particles and the fourth type of light diffusion particles in the light diffusion particles is 40% to 50%, and the mass fraction of the third type of light diffusion particles and the fifth type of light diffusion particles in the light diffusion particles is 45% to 55%.

[0024] Preferably, the material of the substrate is at least one selected from the group consisting of cellulose triacetate, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polycycloolefin, and polyethylene naphthalate.

[0025] Preferably, the material of the substrate is selected from cellulose triacetate;

[0026] The average of the difference between the first orientation angle and the second orientation angle is less than or equal to 2.3°.

[0027] Preferably, the material of the substrate is selected from polyethylene terephthalate or polymethyl methacrylate;

[0028] The average value of the difference between the first orientation angle and the second orientation angle is less than or equal to 3.5°.

[0029] Preferably, the ratio of the long axis of the light diffusion particle to the diameter of the light diffusion particle is greater than or equal to 1, and the ratio of the long axis of the light diffusion particle to the diameter of the light diffusion particle is less than or equal to 100.

[0030] Preferably, the long axis of the light diffusion particles is greater than or equal to 5 microns, and the long axis of the light diffusion particles is less than or equal to 50 microns.

[0031] Preferably, the surface of the light diffusion particles includes at least one of an inorganic cationic group, an inorganic anionic group, a polymer group, a coupling agent group or a surfactant group.

[0032] Preferably, the mass fraction of the light diffusion particles in the first optical functional layer is greater than or equal to 3%, and the mass fraction of the light diffusion particles in the first optical functional layer is less than or equal to 30%.

[0033] Preferably, the absolute value of the difference in refractive index between the substrate and the light diffusion particles is greater than or equal to 0.02.

[0034] Preferably, the thickness of the first optical functional layer is greater than or equal to 15 micrometers, and the thickness of the first optical functional layer is less than or equal to 150 micrometers.

[0035] Preferably, the polarizer further comprises a second optical functional layer located on at least one side of the substrate, wherein the second optical functional layer comprises at least one of an anti-glare sublayer, a transparent hardening sublayer, a low-reflection sublayer, an anti-reflection sublayer, an anti-fingerprint sublayer, and an anti-static electron layer;

[0036] Wherein, the second optical functional layer is located between the polarizing layer and the first optical functional layer; or

[0037] The second optical functional layer is located on a side of the first optical functional layer away from the polarizing layer.

[0038] Preferably, the thickness of the first optical functional layer is greater than or equal to 15 micrometers, and the thickness of the first optical functional layer is less than or equal to 150 micrometers.

[0039] The present invention further provides a display device, comprising a polarizer, wherein the polarizer comprises:

[0040] Polarizing layer;

[0041] A first optical functional layer is located on one side of the polarizing layer, and the first optical functional layer includes a substrate and light diffusion particles dispersed in the substrate;

[0042] wherein the substrate has a glass transition temperature of 30° C. to 500° C., and the substrate has an elastic modulus of 500 MPa to 5000 MPa at 23° C.;

[0043] The orthographic projection of the long axis of the light diffusion particle in the first plane has a first orientation angle, the orthographic projection of the absorption axis of the polarizing layer in the first plane has a second orientation angle, the average of the difference between the first orientation angle and the second orientation angle is less than or equal to 5°, and the first plane is parallel to the plane where the polarizing layer is located. Beneficial effects

[0044] The present invention arranges light diffusion particles in the first optical functional layer of the polarizer, thereby improving the chromaticity and viewing angle of a display device using the polarizer while avoiding the need for additional film layers in the polarizer, reducing the loss of output light of the display device and improving the contrast of the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] FIG1 is a schematic diagram of a first structure of a polarizer provided by an embodiment of the present invention;

[0046] FIG2 is a schematic diagram of a second structure of a polarizer provided by an embodiment of the present invention;

[0047] FIG3 is a schematic diagram of a third structure of a polarizer provided in an embodiment of the present invention;

[0048] FIG4 is a schematic diagram of a fourth structure of a polarizer provided in an embodiment of the present invention;

[0049] FIG5 is a schematic diagram of a fifth structure of a polarizer provided in an embodiment of the present invention;

[0050] FIG6 is a schematic diagram of a first structure of a polarizer in the prior art;

[0051] FIG7 is a schematic diagram of a second structure of a polarizer in the prior art;

[0052] FIG8 is a schematic structural diagram of a display device provided by an embodiment of the present invention. Modes for Carrying Out the Invention

[0053] The present application provides a polarizer and a display device. To make the purpose, technical solution, and effects of the present application more clear and explicit, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0054] Currently, an optical film for expanding the chromaticity and viewing angle needs to be separately added to the polarizer. The increased thickness of the polarizer leads to a reduction in the outgoing light of a display device using the polarizer, resulting in a problem of deteriorated display contrast.

[0055] Referring to FIG. 1 to FIG. 5 , an embodiment of the present invention provides a polarizer 100, including:

[0056] polarizing layer 101;

[0057] The first optical functional layer 102 is located on one side of the polarizing layer 101. The first optical functional layer 102 includes a substrate 102a and light diffusion particles 102b dispersed in the substrate 102a.

[0058] The substrate 102a has a glass transition temperature of 30° C. to 500° C., and an elastic modulus of 500 MPa to 5000 MPa at 23° C.

[0059] The orthographic projection of the long axis of the light diffusion particle 102b in the first plane has a first orientation angle, the orthographic projection of the absorption axis of the polarizing layer 101 in the first plane has a second orientation angle, the average of the difference between the first orientation angle and the second orientation angle is less than or equal to 5°, and the first plane is parallel to the plane where the polarizing layer 101 is located.

[0060] The present invention arranges light diffusion particles 102b in the first optical functional layer 102 of the polarizer 100, thereby improving the chromaticity and viewing angle of the display device using the polarizer 100 while avoiding the need for additional film layers in the polarizer 100, reducing the loss of output light of the display device and improving the contrast of the display device.

[0061] The technical solution of the present invention will now be described in conjunction with specific embodiments.

[0062] Referring to Figures 1 to 5, in some embodiments, the difference between the first and second orientation angles is the angular difference between the first and second orientation angles, the difference between the first and second orientation angles is an absolute value, and the average of the differences between the first and second orientation angles is less than or equal to 5°, and can be 0°, 0.5°, 1°, 1.3°, 1.5°, 1.8°, 2°, 2.3°, 2.5°, 2.8°, 3°, 3.3°, 3.5°, 3.8°, 4°, 4.3°, 4.5°, 4.8°, etc., indicating that the average angular difference between the first and second orientation angles is between -5° and 5°. By ensuring that the absolute value of the angular difference between the orthographic projection of the long axis of the light diffuser particle 102b on the first plane and the orthographic projection of the absorption axis of the polarizing layer 101 on the first plane is less than or equal to 5°, more light is redirected by the light diffuser particle 102b, thereby enhancing the effects of improving chromaticity, viewing angle, and contrast.

[0063] In some embodiments, the long axis of the light diffuser particle 102b forms an angle with the first plane. The angle is acute and less than or equal to 40°. For example, the angle can be 2°, 5°, 8°, 10°, 12°, 15°, 18°, 20°, 22°, 25°, 28°, 30°, 32°, 35°, 38°, or 40°. The angle between the long axis of the light diffuser particle 102b and the first plane facilitates further redirecting more light through the light diffuser particle 102b, thereby enhancing the effects of improving chromaticity, viewing angle, and contrast.

[0064] In some embodiments, the orthographic projection of the long axis of the light diffuser particle 102b on the second plane has a third orientation angle, the orthographic projection of the absorption axis of the polarizing layer 101 on the second plane has a fourth orientation angle, the average difference between the third orientation angle and the fourth orientation angle is greater than or equal to -5°, and the average difference between the third orientation angle and the fourth orientation angle is less than or equal to 5°. The second plane is perpendicular to the plane of the polarizing layer 101, non-perpendicular to the absorption axis of the polarizing layer 101, and non-perpendicular to the long axis of the light diffuser particle 102b. By ensuring that the absolute value of the angular difference between the orthographic projection of the long axis of the light diffuser particle 102b on the second plane and the orthographic projection of the absorption axis of the polarizing layer 101 on the second plane is less than or equal to 5°, the long axis of the light diffuser particle 102b is spatially maintained substantially parallel to the absorption axis of the polarizing layer 101, thereby further allowing more light to change its propagation direction through the light diffuser particle 102b, thereby enhancing the effects of improving chromaticity, viewing angle, and contrast.

[0065] In some embodiments, the difference between the third orientation angle and the fourth orientation angle is the size of the angle difference between the third orientation angle and the fourth orientation angle, the difference between the third orientation angle and the fourth orientation angle is an absolute value, and the average of the difference between the third orientation angle and the fourth orientation angle is less than or equal to 5°, for example, it can be 0°, 0.5°, 1°, 1.3°, 1.5°, 1.8°, 2°, 2.3°, 2.5°, 2.8°, 3°, 3.3°, 3.5°, 3.8°, 4°, 4.3°, 4.5°, 4.8°, etc., indicating that the average angle difference between the third orientation angle and the fourth orientation angle is -5° to 5°.

[0066] In some embodiments, the average of the differences between the first orientation angle and the second orientation angle is less than or equal to 5°, that is, when the second orientation angle is 0°, the average of the angles between the first orientation angle and the second orientation angle is less than or equal to 5°. The average of the differences between the third orientation angle and the fourth orientation angle is less than or equal to 5°, that is, when the fourth orientation angle is 0°, the average of the angles between the third orientation angle and the fourth orientation angle is less than or equal to 5°.

[0067] The average value of the difference between the first orientation angle and the second orientation angle in the first optical functional layer 102 and the average value of the difference between the third orientation angle and the fourth orientation angle can be obtained by photographing the first optical functional layer 102 with an optical microscope and performing statistical analysis using an existing program.

[0068] In some embodiments, the light diffusing particles 102 b are selected from at least one of first type of light diffusing particles, second type of light diffusing particles, third type of light diffusing particles, fourth type of light diffusing particles, and fifth type of light diffusing particles.

[0069] The shapes of the first type of light diffusion particles, the second type of light diffusion particles, the third type of light diffusion particles, the fourth type of light diffusion particles, and the fifth type of light diffusion particles are different from each other.

[0070] In some embodiments, along the direction of extension of the long axis of the first type of light diffuser particles, the change in the diameter of the first type of light diffuser particles is less than or equal to 0.3 microns, for example, 0 microns, 0.28 microns, 0.25 microns, 0.22 microns, 0.2 microns, 0.18 microns, 0.15 microns, 0.12 microns, 0.1 microns, 0.08 microns, 0.05 microns, 0.02 microns, etc. In some embodiments, along the direction of extension of the long axis of the first type of light diffuser particles, the diameter of the first end portion of the first type of light diffuser particles is the same as the diameter of the middle portion of the first type of light diffuser particles, and the diameter of the second end portion of the first type of light diffuser particles is the same as the diameter of the middle portion of the first type of light diffuser particles.

[0071] In some embodiments, the first type of light-diffusing particles may be rod-shaped. When the first type of light-diffusing particles are rod-shaped, a cross-section of the first type of light-diffusing particles on a plane perpendicular to the long axis of the first type of light-diffusing particles is circular or elliptical. When the orthographic projection of the first type of light-diffusing particles on a plane perpendicular to the long axis of the first type of light-diffusing particles is an ellipse, the diameter of the first type of light-diffusing particles is the length of the long axis of the ellipse, and the ratio of the long axis of the ellipse to the short axis of the ellipse is greater than 1 and less than or equal to 3, for example, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.

[0072] In some embodiments, along the extension direction of the long axis of the second type of light diffuser particles, the change value of the diameter of the middle portion of the second type of light diffuser particles is less than or equal to 1 micron, for example, it can be 0 micron, 0.95 micron, 0.8 micron, 0.78 micron, 0.75 micron, 0.72 micron, 0.7 micron, 0.68 micron, 0.65 micron, 0.62 micron, 0.6 micron, 0.58 micron, 0.55 micron, 0.52 micron, 0.5 micron, 0.48 micron, 0.45 micron, 0.42 micron, 0.4 micron, 0.38 micron, 0.35 micron, 0.32 micron, 0.3 micron, 0.28 micron, 0.25 micron, 0.22 micron, 0.2 micron, 0.18 micron, 0.15 micron, 0.12 micron, 0.1 micron, 0.08 micron, 0.05 micron, 0.02 micron, etc.; along the extension direction away from the second type of light diffuser particles, the change value of the diameter of the middle portion of the second type of light diffuser particles is less than or equal to 1 micron, for example, it can be 0 micron, 0.95 micron, 0.8 micron, 0.78 micron, 0.75 micron, 0.72 micron, In the direction of the middle part of the light diffusion particles, the diameter of the first end part of the second type of light diffusion particles gradually decreases, and the diameter change value of the second end part of the second type of light diffusion particles is less than or equal to 1 micron, for example, it can be 0 micron, 0.95 micron, 0.8 micron, 0.78 micron, 0.75 micron, 0.72 micron, 0.7 micron, 0.68 micron, 0.65 micron, 0.62 micron, 0.6 micron, 0.58 micron, 0.55 micron, 0.52 micron, 0.5 micron, 0.48 micron, 0.45 micron, 0.42 micron, 0.4 micron, 0.38 micron, 0.35 micron, 0.32 micron, 0.3 micron, 0.28 micron, 0.25 micron, 0.22 micron, 0.2 micron, 0.18 micron, 0.15 micron, 0.12 micron, 0.1 micron, 0.08 micron, 0.05 micron, 0.02 micron, etc. In some embodiments, the diameter of the first end of the second type of light diffuser particle gradually decreases in the direction away from the middle part of the second type of light diffuser particle, and the diameter of the second end of the second type of light diffuser particle is the same as the diameter of the middle part of the second type of light diffuser particle.

[0073] In some embodiments, the second type of light diffusion particles may be needle-shaped with a diameter reduced at one end.

[0074] In some embodiments, the orthographic projection of the second type of light diffusing particle in a plane perpendicular to the long axis of the second type of light diffusing particle can be circular or elliptical. When the orthographic projection of the second end portion of the second type of light diffusing particle or the middle portion of the second type of light diffusing particle in a plane perpendicular to the long axis of the second type of light diffusing particle forms an ellipse, the ratio of the long axis of the ellipse to the short axis of the ellipse is greater than 1 and less than or equal to 3, for example, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc. The cross-sectional shape of the first end portion of the second type of light diffusing particle in any plane perpendicular to the long axis of the second type of light diffusing particle is consistent with the cross-sectional shape of the middle portion of the second type of light diffusing particle in any plane perpendicular to the long axis of the second type of light diffusing particle, and the area gradually decreases in a direction away from the middle portion of the second type of light diffusing particle.

[0075] In some embodiments, along the extension direction of the long axis of the third type of light diffuser particles, the change value of the diameter of the middle portion of the third type of light diffuser particles is less than or equal to 1 micron, for example, it can be 0 micron, 0.95 micron, 0.8 micron, 0.78 micron, 0.75 micron, 0.72 micron, 0.7 micron, 0.68 micron, 0.65 micron, 0.62 micron, 0.6 micron, 0.58 micron, 0.55 micron, 0.52 micron, 0.5 micron, 0.48 micron, 0.45 micron, 0.4 In some embodiments, the diameter of the third type of light diffusing particles is uniform at the middle portion, and the diameters of the first and second ends of the third type of light diffusing particles gradually change along the direction away from the middle portion of the third type of light diffusing particles.

[0076] In some embodiments, the third type of light diffusion particles may be needle-shaped with diameters decreasing at both ends.

[0077] In some embodiments, the orthographic projection of the third type light diffusing particle in a plane perpendicular to the long axis of the third type light diffusing particle can be circular or elliptical. When the orthographic projection of the middle portion of the third type light diffusing particle in a plane perpendicular to the long axis of the third type light diffusing particle forms an ellipse, the ratio of the long axis to the short axis of the ellipse is greater than 1 and less than or equal to 3, for example, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc. The cross-sectional shape formed by the first end portion and the second end portion of the third type light diffusing particle in any plane perpendicular to the long axis of the third type light diffusing particle is consistent with the cross-sectional shape formed by the middle portion of the third type light diffusing particle in any plane perpendicular to the long axis of the third type light diffusing particle, and the area gradually decreases in a direction away from the middle portion of the third type light diffusing particle.

[0078] In some embodiments, the first end of the fourth type of light diffusion particle is connected to the second end of the fourth type of light diffusion particle in sequence, and the diameter of the fourth type of light diffusion particle gradually decreases along the direction from the first end of the fourth type of light diffusion particle to the second end of the fourth type of light diffusion particle.

[0079] In some embodiments, the fourth type of light diffusion particles may be in the shape of long cones.

[0080] The cross-section of the fourth type of light diffuser particle on a plane perpendicular to the long axis of the fourth type of light diffuser particle is circular or elliptical. Along the direction from the first end of the fourth type of light diffuser particle to the second end of the fourth type of light diffuser particle, the shape of the cross-section of the fourth type of light diffuser particle on a plane perpendicular to the long axis of the fourth type of light diffuser particle is consistent and the area gradually decreases. When the cross-section of the fourth type of light diffuser particle on a plane perpendicular to the long axis of the fourth type of light diffuser particle is elliptical, the diameter of the fourth type of light diffuser particle is the length of the long axis of the ellipse, and the ratio of the long axis of the ellipse to the short axis of the ellipse is greater than 1 and less than or equal to 3, for example, it can be 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.

[0081] In some embodiments, the first end of the fifth type of light diffusion particle is connected in sequence with the second end of the fifth type of light diffusion particle, and the diameter of the first end of the fifth type of light diffusion particle gradually decreases in the direction away from the second end of the fifth type of light diffusion particle, and the diameter of the second end of the fifth type of light diffusion particle gradually decreases in the direction away from the first end of the fifth type of light diffusion particle.

[0082] In some embodiments, the fifth type of light diffusing particles may be biconical in shape.

[0083] The cross-section of the fifth type of light diffuser particle on a plane perpendicular to the long axis of the fifth type of light diffuser particle is circular or elliptical. As the direction moves away from the second end of the fifth type of light diffuser particle, the cross-section of the first end of the fifth type of light diffuser particle on a plane perpendicular to the long axis of the fifth type of light diffuser particle is uniform in shape and gradually decreases in area. As the direction moves away from the first end of the fifth type of light diffuser particle, the cross-section of the second end of the fifth type of light diffuser particle on a plane perpendicular to the long axis of the fifth type of light diffuser particle is uniform in shape and gradually decreases in area. When the cross-section of the fifth type of light diffuser particle on a plane perpendicular to the long axis of the fifth type of light diffuser particle is elliptical, the diameter of the fifth type of light diffuser particle is the length of the long axis of the ellipse, and the ratio of the long axis of the ellipse to the short axis of the ellipse is greater than 1 and less than or equal to 3, for example, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, etc.

[0084] In some embodiments, the light-diffusing particles 102b are selected from at least two of the first, second, third, fourth, and fifth types of light-diffusing particles. Preferably, the light-diffusing particles 102b are a mixture of the first, second, and third types of light-diffusing particles, or a mixture of the first, fourth, and fifth types of light-diffusing particles. Selecting at least two types of light-diffusing particles with different shapes increases the shape diversity of the light-diffusing particles 102b, increases the optical anisotropy of the light-diffusing particles 102b, and helps improve the contrast and brightness enhancement effects of the light-diffusing particles 102b.

[0085] In some embodiments, when the light-diffusing particles 102b are selected from the first type of light-diffusing particles, the second type of light-diffusing particles, and the third type of light-diffusing particles, or when the light-diffusing particles 102b are selected from the first type of light-diffusing particles, the fourth type of light-diffusing particles, and the fifth type of light-diffusing particles, or when the light-diffusing particles 102b are a mixture of the first type of light-diffusing particles, the second type of light-diffusing particles, the third type of light-diffusing particles, the fourth type of light-diffusing particles, and the fifth type of light-diffusing particles, the mass fraction of the first type of light-diffusing particles in the light-diffusing particles 102b is 1% to 8%, for example, 1.5%, 2%, 2. The mass fraction of the second type of light diffusing particles and / or the fourth type of light diffusing particles in the light diffusing particles 102b is 40% to 50%, for example, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, etc. The mass fraction of the third type of light diffusing particles and / or the fifth type of light diffusing particles in the light diffusing particles 102b is 45% to 55%, for example, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, etc. The mixing of the first type of light diffusing particles, the second type of light diffusing particles and / or the fourth type of light diffusing particles, the third type of light diffusing particles and / or the fifth type of light diffusing particles in the light diffusing particles 102b in the above proportions helps to further improve the contrast and brightness enhancement effect of the obtained light diffusing particles 102b.

[0086] In some embodiments, the mass fraction of the light diffusion particles 102b in the first optical functional layer 102 is 3% to 30%, for example, it can be 5%, 8%, 10%, 13%, 15%, 18%, 20%, 23%, 25%, 28%, etc., which is conducive to playing a significant light diffusion effect while avoiding affecting the light transmittance of the optical functional layer.

[0087] In some embodiments, along the direction of the long axis of the light diffusion particle 102 b , the length of the long axis of the light diffusion particle 102 b is the distance between two end points of the long axis of the light diffusion particle 102 b . The long axis of the light diffusion particle 102b is greater than or equal to 5 microns, and the long axis of the light diffusion particle 102b is less than or equal to 50 microns. For example, it can be 10 microns, 15 microns, 20 microns, 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, etc. When the length of the long axis of the light diffusion particle 102b is within the above range, the long axis of the light diffusion particle 102b is easy to orient, so that the average value of the difference between the first orientation angle and the second orientation angle is less than or equal to 5°, and the average value of the difference between the third orientation angle and the fourth orientation angle is less than or equal to 5°; preferably, the long axis of the light diffusion particle 102b is greater than or equal to 10 microns, and the long axis of the light diffusion particle 102b is less than or equal to 30 microns, which is more conducive to making the long axis of the light diffusion particle 102b easy to orient, so that the average value of the difference between the first orientation angle and the second orientation angle is less than or equal to 5°, and the average value of the difference between the third orientation angle and the fourth orientation angle is less than or equal to 5°.

[0088] In some embodiments, the diameter of the light diffusion particle 102b is greater than or equal to 0.5 microns, and the diameter of the light diffusion particle 102b is less than or equal to 5 microns. For example, it can be 0.6 microns, 0.7 microns, 0.8 microns, 0.9 microns, 1 micron, 1.2 microns, 1.5 microns, 1.8 microns, 2 microns, 2.5 microns, 3 microns, 3.5 microns, 4 microns, 4.5 microns, etc., which is conducive to obtaining an aspect ratio that allows more light to change the propagation direction through the long axis surface of the light diffusion particle 102b; preferably, the diameter of the light diffusion particle 102b is greater than or equal to 0.5 microns, and the diameter of the light diffusion particle 102b is less than or equal to 2 microns, which is more conducive to obtaining an aspect ratio that allows more light to change the propagation direction through the long axis surface of the light diffusion particle 102b.

[0089] In some embodiments, the aspect ratio of the light diffusing particles 102b is the ratio of the length of each light diffusing particle to the maximum diameter of the light diffusing particle. The aspect ratio of the light diffusing particles 102b is greater than or equal to 1, and less than or equal to 100. For example, the aspect ratio can be 2, 5, 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. Preferably, the aspect ratio of the light diffusing particles 102b is greater than or equal to 5, and less than or equal to 60.

[0090] In some embodiments, the material of the substrate 102a is selected from resin materials. For example, the material of the substrate 102a can be selected from at least one of triacetyl cellulose (TAC), polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), polycycloolefin (COC), and polyethylene naphthalate two formic acid glycol ester (PEN).

[0091] In some embodiments, the substrate 102a is formed using different materials and in different ways. For example, depending on the material used, the substrate 102a can be formed unstretched, stretched along a first direction, or first stretched along a first direction and then stretched along a second direction. The first direction is parallel to the absorption axis of the polarizing layer 101, and the second direction is perpendicular to the first direction. When the substrate 102a is formed by stretching along the first direction, the light diffusing particles 102b are dispersed in the resin material forming the substrate 102a. The light diffusing particles 102b are also stretched along the first direction, and the orientation of the long axis of the light diffusing particles 102b is adjusted during the formation of the substrate 102a. This facilitates further reduction in the average difference between the first and second orientation angles and / or the average difference between the third and fourth orientation angles. When the substrate 102a is formed by first stretching along the first direction and then stretching along the second direction, the light diffusion particles 102b are dispersed in the resin material forming the substrate 102a. The light diffusion particles 102b also undergo stretching along the first direction and stretching along the second direction. The orientation of the long axis of the light diffusion particles 102b is also adjusted during the formation of the substrate 102a. Therefore, it is beneficial to reduce the average value of the difference between the first orientation angle and the second orientation angle and / or the average value of the difference between the third orientation angle and the fourth orientation angle.

[0092] Therefore, the maximum value of the average of the differences between the first orientation angle and the second orientation angle in the substrate 102a formed without stretching is greater than the maximum value of the average of the differences between the first orientation angle and the second orientation angle in the substrate 102a formed after stretching along the first direction; the maximum value of the average of the differences between the first orientation angle and the second orientation angle in the substrate 102a formed without stretching is greater than the maximum value of the average of the differences between the first orientation angle and the second orientation angle in the substrate 102a formed after stretching along the first direction and then along the second direction. The maximum value of the average of the differences between the first orientation angle and the second orientation angle, that is, the maximum value that the average of the differences between the first orientation angle and the second orientation angle can reach, for example, when the average of the differences between the first orientation angle and the second orientation angle is less than or equal to 5°, the average of the differences between the first orientation angle and the second orientation angle is 5°.

[0093] The maximum value of the average of the differences between the third and fourth orientation angles in the unstretched substrate 102a is greater than the maximum value of the average of the differences between the third and fourth orientation angles in the substrate 102a stretched along the first direction; the maximum value of the average of the differences between the third and fourth orientation angles in the unstretched substrate 102a is greater than the maximum value of the average of the differences between the third and fourth orientation angles in the substrate 102a stretched along the first direction and then stretched along the second direction. The maximum value of the average of the differences between the third and fourth orientation angles, i.e., the maximum value that the average of the differences between the third and fourth orientation angles can reach, is, for example, when the average of the differences between the third and fourth orientation angles is less than or equal to 5°, the maximum value of the average of the differences between the third and fourth orientation angles is 5°.

[0094] In some embodiments, when the material of the substrate 102a is selected from cellulose triacetate, the substrate 102a can be formed without stretching or by stretching along the first direction; when the material of the substrate 102a is selected from polyethylene terephthalate or polyethylene naphthalate, the substrate 102a can be formed by stretching along the first direction or by first stretching along the first direction and then stretching along the second direction; when the material of the substrate 102a is selected from polymethyl methacrylate, the substrate 102a can be formed by first stretching along the first direction and then stretching along the second direction; when the material of the substrate 102a is selected from polycycloolefin or polycarbonate, the substrate 102a can be formed without stretching or by stretching along the first direction or by first stretching along the first direction and then stretching along the second direction.

[0095] In some embodiments, when the material of the substrate 102a is selected from triacetyl cellulose, the substrate 102a is formed by stretching triacetyl cellulose along a first direction. In the formation of the first optical functional layer 102, the light diffusion particles 102b are also stretched along the first direction. The orientation of the long axis of the light diffusion particles 102b is adjusted during the formation of the substrate 102a. The average value of the difference between the first orientation angle and the second orientation angle is less than or equal to 2.3°, for example, it can be 0°, 1.3°, 1.5°, 1.8°, 2°, 2.2°, etc., indicating that the average angular difference between the first orientation angle and the second orientation angle is -2.3° to 2.3°; and / or, the average value of the difference between the third orientation angle and the fourth orientation angle is less than or equal to 2.3°, for example, it can be 0°, 1.3°, 1.5°, 1.8°, 2°, 2.2°, etc., indicating that the average angular difference between the third orientation angle and the fourth orientation angle is -2.3° to 2.3°.

[0096] In some embodiments, the material of the substrate 102a is polyethylene terephthalate or polymethyl methacrylate. When the substrate 102a is first stretched along the first direction and then stretched along the second direction, the light diffusion particles 102b are also stretched along the first direction and along the second direction. The orientation of the long axis of the light diffusion particles 102b is adjusted twice during the formation of the substrate 102a. The average difference between the first orientation angle and the second orientation angle is less than or equal to 3.5°, for example, 0°, 1.3°, 1.5°, or 2.5°. °, 1.8°, 2°, 2.3°, 2.5°, 2.8°, 3°, 3.3°, etc., indicating that the average angular difference between the first orientation angle and the second orientation angle is -3.5° to 3.5°; and / or, the average of the difference between the third orientation angle and the fourth orientation angle is less than or equal to 3.5°, for example, it can be 0°, 1.3°, 1.5°, 1.8°, 2°, 2.3°, 2.5°, 2.8°, 3°, 3.3°, etc., indicating that the average angular difference between the third orientation angle and the fourth orientation angle is -3.5° to 3.5°.

[0097] In some embodiments, the light diffusion particles 102b are whiskers and 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.

[0098] In some embodiments, the light-diffusing particles 102b may be surface-modified to improve their dispersibility within the substrate 102a or enhance their toughness and other functional properties. When the light-diffusing particles 102b are surface-modified, the surface of the light-diffusing particles 102b is modified with at least one of an inorganic cation, an inorganic anion, a polymer, a coupling agent, or a surfactant. Specifically, the surface of the light-diffusing particles 102b includes at least one of an inorganic cation group, an inorganic anion group, a polymer group, a coupling agent group, or a surfactant group.

[0099] In some embodiments, the surface of the light diffusion particle 102b is modified by at least one of inorganic magnesium salt, inorganic calcium salt, inorganic barium salt, inorganic strontium salt, stearic acid, stearate, sulfonic acid surfactant, thio surfactant, titanate, aluminate, polyacrylamide, silane, alkyl phosphate ester, aryl phosphate ester, alkyl phosphate, aryl phosphate, alkyl alcohol amide phosphate, alkyl alcohol amide phosphate, imidazoline phosphate, imidazoline phosphate, high polyphosphate, high polyphosphate and siloxane phosphate.

[0100] Specifically, the surface of the light diffusing particle 102b is 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, titanates, aluminates, polyacrylamide, silane, alkyl phosphates, aryl phosphates, alkyl phosphates, aryl phosphates, alkylolamide phosphates, alkylolamide phosphates, imidazoline phosphates, imidazoline phosphates, high polyphosphates, high polyphosphates, and siloxane phosphates. Preferably, the surface of the light diffusing particle 102b is modified with at least one selected from the group consisting of sulfonic acid surfactants and thio surfactants. The sulfonic acid surfactant can be selected from at least one of alkyl sulfonates and fluoroalkyl sulfonates, specifically, such as at least one of sodium dodecyl sulfonate, sodium dodecylbenzenesulfonate, and sodium fluorododecyl sulfonate; the thio surfactant can be selected from at least one of thiols and fluorothiols, specifically, such as at least one of octyl mercaptan, dodecanethiol, tetradecanethiol, octadecanethiol, fluorooctyl mercaptan, and fluorododecyl mercaptan. When the sulfonic acid surfactant is mixed with the light-diffusing particles to be surface-modified, the sulfonic acid surfactant groups form a sulfonic acid shell layer on the surface of the whisker, such as a benzene ring sulfonic acid shell layer, which is beneficial to protecting the light-diffusing particles, enhancing the toughness of the light-diffusing particles 102b, and reducing the breakage of the light-diffusing particles 102b in the first optical functional layer 102; when the sulfo surfactant groups are mixed with the light-diffusing particles to be surface-modified, the sulfo surfactant groups and the hydroxyl groups on the whisker surface form an OSO cross-linked network. The bond energy of OSO is relatively large, which is beneficial to protecting the light-diffusing particles 102b during the process of mixing the light-diffusing particles 102b with the material of the substrate 102a and forming the first optical functional layer 102, reducing the breakage of the light-diffusing particles 102b, and improving the improvement effect of the light-diffusing particles 102b on optical functions such as contrast and brightness. More preferably, the light diffusion particles 102b are treated with at least one of sulfonic acid surfactants containing fluorine substituents and thio surfactants containing fluorine substituents, specifically, at least one of sodium fluorododecylsulfonate, fluorooctanethiol, and fluorododecylthiol, wherein the fluorine atom has 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, which is beneficial to protecting the carbon-carbon bond, thereby improving the stability of the light diffusion particles 102b.

[0101] In some embodiments, the absolute value of the difference in refractive index between the substrate 102a and the light diffusion particle 102b is greater than or equal to 0.02, for example, it can be 0.03, 0.05, 0.09, 0.1, 0.15, 0.2, etc., to achieve the light diffusion function of the light diffusion particle 102b.

[0102] In some embodiments, the substrate 102a has a glass transition temperature of 30°C to 500°C, for example, 40°C, 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, etc.; the substrate 102a has an elastic modulus of 500 MPa to 5000 MPa at 23°C, 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.

[0103] In some embodiments, the elastic modulus of the substrate 102a can be obtained at a humidity of 50%.

[0104] In some embodiments, the thickness of the first optical functional layer 102 is greater than or equal to 15 microns, and the thickness of the first optical functional layer 102 is less than or equal to 150 microns. For example, the thickness can be 20 microns, 25 microns, 30 microns, 40 microns, 50 microns, 60 microns, 80 microns, 100 microns, 120 microns, 130 microns, 140 microns, etc., so as to facilitate the processing of the first optical functional layer 102 and maintain the appropriate light transmittance of the first optical functional layer 102.

[0105] In some embodiments, the first optical functional layer 102 further includes a plasticizer dispersed in the substrate 102a, and the plasticizer can be selected from at least one of a phosphate plasticizer, a citrate plasticizer, and a fatty acid ester plasticizer; in the first optical functional layer 102, the mass fraction of the plasticizer is greater than or equal to 4% and less than or equal to 6%, for example, it can be 5%.

[0106] In some embodiments, the first optical functional layer 102 further includes an ultraviolet absorber dispersed in the substrate 102a, and the ultraviolet absorber can be selected from at least one of a benzophenone ultraviolet absorber and a benzotriazole ultraviolet absorber. The mass fraction of the plasticizer is greater than or equal to 0.8% and less than or equal to 1.2%, for example, it can be 1%.

[0107] Referring to FIG. 1 to FIG. 5 , in some embodiments, the polarizer 100 further includes a second optical functional layer 103 located on at least one side of the substrate 102 a .

[0108] The second optical functional layer 103 is located between the polarizing layer 101 and the first optical functional layer 102 ; or, the second optical functional layer 103 is located on a side of the first optical functional layer 102 away from the polarizing layer 101 .

[0109] In some embodiments, the second optical functional layer 103 is located on a side of the first optical functional layer 102 away from the polarizing layer 101 , and the polarizer 100 further includes a first adhesive layer 104 located on the first optical functional layer 102 close to the polarizing layer 101 .

[0110] The first adhesive layer 104 is in direct contact with the polarizing layer 101 ; or the polarizer 100 further includes a protective layer 105 located between the first optical functional layer 102 and the polarizing layer 101 , and the first adhesive layer 104 is in direct contact with the protective layer 105 .

[0111] In some embodiments, the first adhesive layer 104 is in direct contact with the first optical functional layer 102 , and the first adhesive layer 104 is in direct contact with the polarizing layer 101 ; or, the first adhesive layer 104 is in direct contact with the first optical functional layer 102 , and the first adhesive layer 104 is in direct contact with the protective layer 105 .

[0112] In some embodiments, the first adhesive layer 104 can be selected from at least one of water-based adhesive, pressure-sensitive adhesive, and UV adhesive. The material of the water-based adhesive can be selected from polyvinyl alcohol, the material of the pressure-sensitive adhesive can be selected from acrylate copolymers, and the material of the UV adhesive can be selected from multifunctional acrylate monomers.

[0113] Referring to Figures 1 to 5 , in some embodiments, the second optically functional layer 103 includes at least one of an anti-glare sub-layer 106, a transparent hardened sub-layer 107, a low-reflection sub-layer 108, an anti-reflection sub-layer, an anti-fingerprint sub-layer, and an anti-static electron layer. When the second optically functional layer 103 is the low-reflection sub-layer 108, the low-reflection sub-layer 108 may be formed by stacking a transparent hardened sub-layer 108a and a low-refractive sub-layer 108b.

[0114] In some embodiments, the polarizing layer 101 is composed of polyvinyl alcohol and a dye.

[0115] In some embodiments, the polarizer 100 further includes a release layer 109 located on a side of the polarizing layer 101 away from the first optically functional layer 102. The release layer 109 is bonded to the polarizing layer 101 via a second adhesive layer 110. When the polarizer 100 is applied to the display device, the release layer 109 is removed to expose the second adhesive layer 110, so that the polarizer 100 is bonded to the display panel via the second adhesive layer 110.

[0116] In some embodiments, the polarizer 100 further includes a compensation layer 111 located between the second adhesive layer 110 and the polarizing layer 101 .

[0117] In an embodiment of the present invention, light diffusion particles 102b are disposed in the first optical functional layer 102 of the polarizer 100. This improves the chromatic viewing angle of a display device to which the polarizer 100 is applied while avoiding the need for an additional film layer in the polarizer 100. This reduces the loss of emitted light from the display device and improves the contrast of the display device.

[0118] Referring to FIG. 8 , an embodiment of the present invention further provides a display device 10 , including the polarizer 100 as described above.

[0119] Specifically, the display device includes a display panel 200 and a first polarizer 300 . The first polarizer 300 is located on the light-emitting side of the display panel 200 . The first polarizer 300 is selected from the polarizer 100 described above.

[0120] 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.

[0121] In some embodiments, the first optical functional layer in the first polarizer 300 is located on a side of the polarizing layer in the first polarizer 300 away from the display panel.

[0122] When 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 away from the first polarizer 300. The backlight module 400 is configured to provide light for the display panel 200. The display device 10 further 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 polarizer 100 described above, or the second polarizer 500 may not be selected from the polarizer 100 described above.

[0123] Next, the present invention will be described in more detail with reference to some examples. However, it should be noted that these examples are provided for illustration only and should not be understood in any way as limiting the present invention.

[0124] Example 1

[0125] The masterbatch cellulose triacetate (refractive index 1.50) powder is dissolved in a solvent, 5% of the total solid mass of the plasticizer triphenyl phosphate and 1% of the total solid mass of the 2-(2-hydroxy-5-methylphenyl) benzotriazole ultraviolet absorber are added, and after mixing evenly, rod-shaped calcium sulfate light-diffusing particles, needle-shaped calcium sulfate light-diffusing particles with a reduced diameter at one end, and needle-shaped calcium sulfate light-diffusing particles with reduced diameters at both ends are added, wherein the mass fractions of the three in the light-diffusing particles are 5%, 45%, and 50%, respectively. The light-diffusing particles obtained after mixing the three in the masterbatch have a refractive index of 1.59, a major axis of 10-30 μm, and a diameter of 0.5-2 μm. The three light-diffusing particles are all surface-modified, and the surface modifier is stearic acid; the light-diffusing particles are added The added amount is 5% of the total mass of the solid, and a uniform mother liquor is formed by stirring; after filtering the mother liquor, it is extruded into a single layer on a steel belt through an extruder, and dried to form a film. After the film is peeled off from the steel belt, it is longitudinally stretched (in the first direction) to orient the light diffusion particles and triacetate cellulose to form a substrate and light diffusion particles dispersed in the substrate, thereby forming a first optical functional layer, the thickness of the first optical functional layer is 40μm, and the second optical functional layer is coated on one side, the second optical functional layer is a transparent hardened sublayer, and the other side is coated with a pressure-sensitive adhesive as a first adhesive layer, and then roll-to-roll bonding with a pre-polarizer (formed by stacking a release layer, a second adhesive layer, a compensation layer, a polarizing layer, and a protective layer) is performed to obtain a polarizer. The structure of the polarizer is shown in Figure 1.

[0126] Example 2

[0127] The masterbatch polyethylene terephthalate (refractive index 1.62) pellets are dissolved in a solvent, 5% of the total solid mass of 2-(2-hydroxy-5-methylphenyl)benzotriazole ultraviolet absorber is added, and after mixing evenly, rod-shaped calcium carbonate light-diffusing particles, needle-shaped calcium carbonate light-diffusing particles with a reduced diameter at one end, and needle-shaped calcium carbonate light-diffusing particles with reduced diameters at both ends are added, wherein the mass fractions of the three in the light-diffusing particles are 5%, 45%, and 50%, respectively. The light-diffusing particles obtained in the masterbatch after mixing the three have a refractive index of 1.67, a major axis of 10-30 μm, and a diameter of 0.5-2 μm. The three light-diffusing particles are all surface-modified, and the surface modifier is fluorinated thiol; the light-diffusing particles are added The amount is 2.5% of the total solid mass, and it is evenly mixed through a screw extruder and then cast into a film. The film is first stretched longitudinally (in the first direction) and then stretched transversely (in the second direction) to orient the light diffusion particles and polyethylene terephthalate to form a substrate and the light diffusion particles dispersed in the substrate. The film formed at this time is the first optical functional layer, and the thickness of the first optical functional layer is 80 μm. The second optical functional layer is coated on one side, and the second optical functional layer is an anti-glare sub-layer. The other side is coated with a pressure-sensitive adhesive as the first adhesive layer, and then it is roll-to-roll bonded with a pre-polarizer (formed by stacking a release layer, a second adhesive layer, a compensation layer, a polarizing layer, and a protective layer) to form a polarizer. The structure of the polarizer is shown in Figure 2.

[0128] Example 3

[0129] The same or similar embodiment is as Example 1, except that after the obtained first optical functional layer is treated with alkali, hydrogel is used as the first adhesive layer to directly bond it to the polarizing layer (i.e., the protective layer is omitted in the pre-polarizer). The structure of the obtained polarizer is shown in FIG3 .

[0130] Example 4

[0131] The same or similar embodiment is the same as or similar to embodiment 1, except that the second optical functional layer is a low-reflection sublayer, and the low-reflection sublayer is formed by stacking a transparent hardening sub-part and a low-refractive sub-part. The structure of the obtained polarizer is shown in FIG4 .

[0132] Example 5

[0133] The same or similar embodiment is the same as or similar to Example 2, except that the masterbatch is polymethyl methacrylate (refractive index 1.50), the amount of light diffusion particles added is 5% of the total solid mass, the thickness of the first optical functional layer formed after longitudinal stretching and transverse stretching is 40 μm, and the structure of the obtained polarizer is shown in Figure 2.

[0134] Example 6

[0135] The same or similar embodiment is as Example 2, except that the first optical functional layer is directly bonded to the polarizing layer (i.e., the protective layer is omitted in the pre-polarizer) using UV glue as the first adhesive layer. The structure of the obtained polarizer is shown in FIG5 .

[0136] Comparative Example 1

[0137] Rod-shaped calcium carbonate light-diffusing particles, needle-shaped calcium carbonate light-diffusing particles with a reduced diameter at one end, and needle-shaped calcium carbonate light-diffusing particles with reduced diameters at both ends are added to a pressure-sensitive adhesive, wherein the mass fractions of the three in the light-diffusing particles are 5%, 45%, and 50%, respectively. The light-diffusing particles after mixing the three have a refractive index of 1.67, a major axis of 10-30 μm, and a diameter of 0.5-2 μm. All three light-diffusing particles are surface-modified with stearic acid as the surface modifier. The amount of light-diffusing particles added is 10% of the total solid mass. The light-diffusing particles are coated on the other surface of a substrate 112 (made of polyethylene terephthalate) having a low-reflective coating on one surface to obtain an optical diffusion adhesive layer 113 (the thickness of the optical diffusion adhesive layer is 20 μm). After drying, the optical diffusion adhesive layer 113 is roll-to-roll bonded to the surface of a protective layer (made of polyethylene terephthalate) to obtain a polarizer. The structure of the obtained polarizer is shown in FIG6 .

[0138] Comparative Example 2

[0139] The method is the same as or similar to Example 2, except that the light diffusion particles are spherical, thereby obtaining a comparative optical functional layer 114 . The structure of the obtained polarizer is shown in FIG7 .

[0140] The first optically functional layers obtained in Examples 1 to 6, the optically diffuse adhesive layer obtained in Comparative Example 1, and the comparative optically functional layer obtained in Comparative Example 2 were photographed using an optical microscope (Olympus MX63L, magnification: 500× (10×50), and the absolute value of the average orientation angle of the light diffusing particles in each of the first optically functional layer, the optically diffuse adhesive layer, and the comparative optically functional layer relative to the absorption axis of the polarizing layer was obtained using the Image J program.

[0141] The polarizers obtained in Examples 1-6 and Comparative Examples 1 and 2 were placed on the light-emitting side of the same model of liquid crystal display modules (same liquid crystal display panel, same backlight module, and same structure of polarizer located between the liquid crystal display panel and the backlight module). The contrast and chromaticity viewing angle results of the display devices were obtained using a Konica Minolta CS2000A optical spectrum analyzer.

[0142]

[0143] As shown in Table 1, compared to optical diffusion adhesive layers formed from pressure-sensitive adhesives, Examples 1 to 6, by dispersing light-diffusing particles within a substrate and subjecting the light-diffusing particles to at least longitudinal stretching during substrate formation, effectively improve the contrast and chromatic viewing angle of displays employing such polarizers when applied to the polarizer. Furthermore, compared to comparative optical functional layers employing spherical light-diffusing particles, Examples 1 to 6 employ a mixture of rod-shaped light-diffusing particles, needle-shaped light-diffusing particles with a reduced diameter at one end, and needle-shaped light-diffusing particles with reduced diameters at both ends, resulting in an average absolute value of the orientation angle of the long axis of the light-diffusing particles relative to the absorption axis of the polarizing layer of less than or equal to 3.5°, resulting in a more pronounced improvement in chromatic viewing angle.

[0144] An embodiment of the present invention discloses a polarizer and a display device. The polarizer includes a polarizing layer and a first optically functional layer located on one side of the polarizing layer. The first optically functional layer includes a substrate and light-diffusing particles dispersed in the substrate. The substrate has a glass transition temperature of 30°C to 500°C, and an elastic modulus of 500 MPa to 5000 MPa at 23°C. The absolute value of the average of the differences between the orientation angle of the orthographic projection of the long axis of the light-diffusing particles in a first plane and the orientation angle of the orthographic projection of the absorption axis of the polarizing layer in the first plane is less than or equal to 5°. By arranging the light-diffusing particles in the first optically functional layer of the polarizer, the present invention improves the chromaticity and viewing angle of a display device using the polarizer while avoiding the need for an additional film layer in the polarizer, reducing the loss of emitted light from the display device and improving the contrast of the display device.

[0145] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of this application, and all these changes or substitutions should fall within the scope of protection of the claims attached to this application.

Claims

1. A polarizing film, It is characterized in that include: Polarizing layer; A first optical functional layer, located on one side of the polarizing layer, the first optical functional layer comprising a substrate and light diffusion particles dispersed in the substrate; wherein the substrate has a glass transition temperature of 30°C to 500°C, and the substrate has an elastic modulus of 500 MPa to 5000 MPa at 23°C; The orthographic projection of the long axis of the light diffusion particle in the first plane has a first orientation angle, the orthographic projection of the absorption axis of the polarizing layer in the first plane has a second orientation angle, the average of the difference between the first orientation angle and the second orientation angle is less than or equal to 5°, and the first plane is parallel to the plane where the polarizing layer is located.

2. The polarizer according to claim 1, It is characterized in that An angle is formed between the long axis of the light diffusion particle and the first plane, and the angle is an acute angle, which is less than or equal to 40°.

3. The polarizer according to claim 2, It is characterized in that The light diffusion particles are selected from at least one of the first type of light diffusion particles, the second type of light diffusion particles, the third type of light diffusion particles, the fourth type of light diffusion particles, and the fifth type of light diffusion particles; Wherein, along the extension direction of the long axis of the first type of light diffusion particles, the change value of the diameter of the first type of light diffusion particles is less than or equal to 0.3 micrometers; Along the extension direction of the long axis of the second type of light diffusion particles, the change value of the diameter of the middle portion of the second type of light diffusion particles is less than or equal to 1 micron, and along the direction away from the middle portion of the second type of light diffusion particles, the diameter of the first end portion of the second type of light diffusion particles gradually decreases, and the change value of the diameter of the second end portion of the second type of light diffusion particles is less than or equal to 1 micron; Along the extension direction of the long axis of the third type light diffusion particle, the change value of the diameter of the middle part of the third type light diffusion particle is less than or equal to 1 micron, and along the direction away from the middle part of the third type light diffusion particle, the diameter of the first end of the third type light diffusion particle gradually decreases, and the diameter of the second end of the third type light diffusion particle gradually decreases; The first end of the fourth type of light diffusion particle is connected to the second end of the fourth type of light diffusion particle in sequence, and the diameter of the fourth type of light diffusion particle gradually decreases along the direction from the first end of the fourth type of light diffusion particle to the second end of the fourth type of light diffusion particle; The first end of the fifth type of light diffusion particle is connected to the second end of the fifth type of light diffusion particle in sequence, and the diameter of the first end of the fifth type of light diffusion particle gradually decreases in the direction away from the second end of the fifth type of light diffusion particle, and the diameter of the second end of the fifth type of light diffusion particle gradually decreases in the direction away from the first end of the fifth type of light diffusion particle.

4. The polarizer according to claim 3, It is characterized in that The first type of light diffusion particles are rod-shaped particles, the second type of light diffusion particles are needle-shaped particles with a reduced diameter at one end, the third type of light diffusion particles are needle-shaped particles with reduced diameters at both ends, the fourth type of light diffusion particles are long cone-shaped particles, and the fifth type of light diffusion particles are double cone-shaped particles.

5. The polarizer according to claim 3, It is characterized in that The light diffusion particles are selected from at least two of the first type of light diffusion particles, the second type of light diffusion particles, the third type of light diffusion particles, the fourth type of light diffusion particles, and the fifth type of light diffusion particles.

6. The polarizer according to claim 5, It is characterized in that The light diffusion particles are selected from first type of light diffusion particles, second type of light diffusion particles and third type of light diffusion particles.

7. The polarizer according to claim 5, It is characterized in that The light diffusion particles are selected from the first type of light diffusion particles, the fourth type of light diffusion particles, and the fifth type of light diffusion particles.

8. The polarizer according to claim 5, It is characterized in that The light diffusion particles are selected from the first type of light diffusion particles, the second type of light diffusion particles, the third type of light diffusion particles, the fourth type of light diffusion particles, and the fifth type of light diffusion particles.

9. The polarizer according to claim 8, It is characterized in that The mass fraction of the first type of light diffusion particles in the light diffusion particles is 1% to 8%, the mass fraction of the second type of light diffusion particles and the fourth type of light diffusion particles in the light diffusion particles is 40% to 50%, and the mass fraction of the third type of light diffusion particles and the fifth type of light diffusion particles in the light diffusion particles is 45% to 55%.

10. The polarizer according to claim 1, It is characterized in that The material of the substrate is selected from at least one of triacetyl cellulose, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polycycloolefin, and polyethylene naphthalate.

11. The polarizer according to claim 10, It is characterized in that The material of the substrate is selected from cellulose triacetate; Wherein, the average value of the difference between the first orientation angle and the second orientation angle is less than or equal to 2.3°.

12. The polarizer according to claim 10, It is characterized in that The material of the substrate is selected from polyethylene terephthalate or polymethyl methacrylate; Wherein, the average value of the difference between the first orientation angle and the second orientation angle is less than or equal to 3.5°.

13. The polarizer according to claim 1, It is characterized in that A ratio of a long axis of the light diffusion particle to a diameter of the light diffusion particle is greater than or equal to 1, and a ratio of a long axis of the light diffusion particle to a diameter of the light diffusion particle is less than or equal to 100.

14. The polarizer according to claim 13, It is characterized in that The major axis of the light diffusion particle is greater than or equal to 5 micrometers, and the major axis of the light diffusion particle is less than or equal to 50 micrometers.

15. The polarizer according to claim 1, It is characterized in that The surface of the light diffusion particle includes at least one of an inorganic cationic group, an inorganic anionic group, a polymer group, a coupling agent group or a surfactant group.

16. The polarizer according to claim 1, It is characterized in that The mass fraction of the light diffusion particles in the first optical function layer is greater than or equal to 3%, and the mass fraction of the light diffusion particles in the first optical function layer is less than or equal to 30%.

17. The polarizer according to claim 1, It is characterized in that An absolute value of a difference in refractive index between the substrate and the light diffusion particles is greater than or equal to 0.

02.

18. The polarizer according to claim 1, It is characterized in that The polarizer further comprises a second optical functional layer located on at least one side of the substrate, wherein the second optical functional layer comprises at least one of an anti-glare sublayer, a transparent hardening sublayer, a low-reflection sublayer, an anti-reflection sublayer, an anti-fingerprint sublayer, and an anti-static electron layer; Wherein, the second optical functional layer is located between the polarizing layer and the first optical functional layer; or, The second optical function layer is located on a side of the first optical function layer away from the polarizing layer.

19. The polarizer according to claim 1, It is characterized in that The thickness of the first optical function layer is greater than or equal to 15 micrometers, and the thickness of the first optical function layer is less than or equal to 150 micrometers.

20. A display device, It is characterized in that A polarizer is included, wherein the polarizer includes: Polarizing layer; A first optical functional layer, located on one side of the polarizing layer, the first optical functional layer comprising a substrate and light diffusion particles dispersed in the substrate; wherein the substrate has a glass transition temperature of 30°C to 500°C, and the substrate has an elastic modulus of 500 MPa to 5000 MPa at 23°C; The orthographic projection of the long axis of the light diffusion particle in the first plane has a first orientation angle, the orthographic projection of the absorption axis of the polarizing layer in the first plane has a second orientation angle, the average of the difference between the first orientation angle and the second orientation angle is less than or equal to 5°, and the first plane is parallel to the plane where the polarizing layer is located.

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