Polarizer and preparation method therefor, and display panel

Abstract

The present application provides a polarizer and a preparation method therefor, and a display panel. The polarizer comprises a polarizing film and a protective layer disposed on one side of the polarizing film, the side of the protective layer away from the polarizing film is provided with an uneven structure, and the uneven structure comprises a plurality of uneven sub-surfaces of different shapes and / or sizes, so as to mitigate the rainbow mura problem in existing display devices.

Description

Polarizer and preparation method thereof, and display panel Technical Field

[0001] The present application relates to the field of display technology, and in particular to a polarizer, a preparation method thereof, and a display panel. Background Art

[0002] With the rapid development of liquid crystal display technology, LCD screens have evolved from small-sized mobile phone screens to large-sized computer and television screens, becoming the mainstream product in the display field. As a result, the market has higher requirements for display image quality and environmental adaptability.

[0003] The structure of a liquid crystal display (LCD) consists primarily of a layer of liquid crystal sandwiched between two glass substrates. From bottom to top, the components are: a backlight, a light guide plate, a lower polarizer, a lower glass substrate, a thin-film transistor array, a liquid crystal layer, a color filter, an upper glass substrate, and an upper polarizer. Light from the backlight is diffused by the light guide plate and then passes through the lower polarizer, whose absorption axis is oriented at 90° (perpendicular to the paper and outward). The component of natural light at 90° is absorbed, converting it into linearly polarized light with a polarization direction parallel to the 0° direction (horizontally parallel to the paper). In the absence of a change in the electric field, the liquid crystal molecules remain unchanged, and the outgoing linearly polarized light remains unchanged and is absorbed by the upper polarizer, whose absorption axis is oriented at 0°. No light passes through, resulting in a dark state. When current flows through the transistors, generating a change in the electric field, the liquid crystal molecules deflect, converting the horizontally polarized light into vertically polarized light, which then passes through the upper polarizer without being absorbed, resulting in a bright state. In addition, the upper glass is bonded to the color filter. Based on the principle of colorimetry, each pixel is composed of three sub-pixels RGB. These sub-pixels that emit red, blue, and green colors are mixed and transmitted to the human eye, thus forming a colorful display screen.

[0004] In the operating principle of display devices, polarizers play a crucial role as optical switches. Their basic components consist of a substrate protective layer, a polarizing layer, a liquid crystal compensation layer, a pressure-sensitive adhesive (PSA), and a release film. In long-term applications, polarizers with a polyethylene terephthalate (PET) substrate as the substrate protective layer often experience birefringence due to the crystalline properties of PET, which can easily cause rainbow patterns in displays. SUMMARY OF THE INVENTION

[0005] The present application provides a polarizer, a preparation method thereof, and a display panel to alleviate the technical problem of rainbow stripes in existing display devices.

[0006] To solve the above problems, the technical solutions provided by this application are as follows:

[0007] The embodiment of the present application provides a polarizer, comprising:

[0008] polarizing film;

[0009] A protective layer is provided on one side of the polarizing film;

[0010] Wherein, a concave-convex structure is provided on a side of the protective layer away from the polarizing film, and the concave-convex structure includes a plurality of concave-convex sub-surfaces of different shapes and / or sizes.

[0011] In the polarizer provided in the embodiment of the present application, the polarizer further includes a dimming film arranged on a side of the protective layer away from the polarizing film, and one side of the dimming film has the concave-convex structure.

[0012] In the polarizer provided in the embodiment of the present application, the dimming film has the concave-convex structure on the side away from the protective layer; the dimming film includes a substrate layer and first diffusion particles dispersed in the substrate layer, and at least some of the first diffusion particles protrude from the surface of the dimming film on the side away from the protective layer to form the concave-convex structure.

[0013] In the polarizer provided in the embodiment of the present application, the dimming film has the concave-convex structure on the side close to the protective layer; the dimming film includes a substrate layer and first diffusion particles dispersed in the substrate layer, and at least some of the first diffusion particles protrude from the surface of the dimming film on the side close to the protective layer to form the concave-convex structure.

[0014] In the polarizer provided in the embodiment of the present application, the dimming film also includes second diffusion particles dispersed in the substrate layer, the second diffusion particles and the first diffusion particles protrude from the same side surface of the dimming film, and some of the first diffusion particles are located on the side of the second diffusion particles away from the concave-convex structure.

[0015] In the polarizer provided in the embodiment of the present application, the particle size of the first diffusion particles is larger than the particle size of the second diffusion particles.

[0016] In the polarizer provided in the embodiment of the present application, the substrate layer includes an ultraviolet light-cured resin substrate, the first diffusion particles include polymethyl methacrylate particles, and the second diffusion particles include at least one of silicon dioxide particles, titanium dioxide particles, and zinc dioxide particles.

[0017] In the polarizer provided in the embodiment of the present application, the haze range of the polarizer is 20% to 70%.

[0018] In the polarizer provided in the embodiment of the present application, the angle between the normal line of the concave-convex sub-surface and the plane parallel to the plane where the protective layer is located is distributed in the range of 0 degrees to 180 degrees.

[0019] The present invention also provides a method for preparing a polarizer, which includes:

[0020] A protective layer is attached to one side of the polarizing film;

[0021] A concave-convex structure is prepared on a side of the protective layer away from the polarizing film, wherein the concave-convex structure includes a plurality of concave-convex sub-surfaces with different shapes and / or sizes.

[0022] In the method for preparing a polarizer provided in an embodiment of the present application, the step of preparing a concave-convex structure on a side of the protective layer away from the polarizing film includes:

[0023] Mixing ultraviolet curing resin, ultraviolet curing monomer, and first diffusion particles in a solvent to form a dimming solution;

[0024] Applying the dimming solution on a side of the protective layer away from the polarizing film;

[0025] The dimming solution is solidified to form the dimming film, and the concave-convex structure is formed on one side of the dimming film.

[0026] In the polarizer preparation method provided in an embodiment of the present application, the dimming solution also includes second diffusing particles, and the particle size of the second diffusing particles is smaller than the particle size of the first diffusing particles; the second diffusing particles include inorganic silica particles with a particle size of 30 nanometers to 70 nanometers, and the first diffusing particles include polymethyl methacrylate particles with a particle size of 2 micrometers to 3 micrometers.

[0027] In the polarizer preparation method provided in an embodiment of the present application, the mass fraction of the first diffusion particles and the second diffusion particles in the dimming solution ranges from 2.5% to 20%, wherein the ratio of the first diffusion particles to the second diffusion particles is 7:3.

[0028] An embodiment of the present application further provides a display panel, which includes the polarizer of one of the aforementioned embodiments or a polarizer manufactured by the polarizer manufacturing method of one of the aforementioned embodiments. Beneficial effects

[0029] In the polarizer, preparation method thereof, and display panel provided by the present application, the polarizer includes a polarizing film and a protective layer, the protective layer is arranged on one side of the polarizing film, and a concave-convex structure is provided on the side of the protective layer away from the polarizing film, and the concave-convex structure includes multiple concave-convex sub-surfaces of different shapes and / or sizes; the present application provides a concave-convex structure on the side of the protective layer away from the polarizing film, so that when the light directed toward the polarizer passes through the concave-convex structure, the light will be evenly scattered based on the principle of diffuse reflection. When the evenly scattered light passes through the protective layer again, the light intensity energy of each wavelength is evenly dispersed, thereby avoiding the occurrence of rainbow stripes, and solving the technical problem of rainbow stripes in existing display devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] FIG1 is a schematic diagram of a cross-sectional structure of a polarizer provided in an embodiment of the present application.

[0032] FIG2 is a schematic diagram of the detailed structure of the dimming film provided in an embodiment of the present application.

[0033] FIG3 is a schematic diagram of a cross-sectional structure of a display panel provided in an embodiment of the present application.

[0034] FIG4 is a schematic diagram of another cross-sectional structure of a display panel provided in an embodiment of the present application.

[0035] FIG5 is a schematic diagram of another cross-sectional structure of a display panel provided in an embodiment of the present application.

[0036] FIG6 is a schematic diagram of light propagation when the display panel provided by an embodiment of the present application does not include a dimming film.

[0037] FIG. 7 is a schematic diagram showing the propagation of light when the display panel provided by an embodiment of the present application includes a dimming film.

[0038] FIG8 is a schematic flow chart of a method for preparing a polarizer according to an embodiment of the present application. Modes for Carrying Out the Invention

[0039] The following descriptions of the embodiments are with reference to the attached diagrams to illustrate specific embodiments that the present application can be implemented in. The directional terms mentioned in this application, such as [up], [down], [front], [back], [left], [right], [inside], [outside], [side], etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present application, rather than to limit the present application. In the figures, units with similar structures are represented by the same reference numerals. In the accompanying drawings, the thickness of some layers and areas is exaggerated for clarity of understanding and ease of description. That is, the size and thickness of each component shown in the drawings are arbitrarily shown, but the present application is not limited to this.

[0040] To address the rainbow pattern problem in existing display devices, the inventors of this application discovered that the polyethylene terephthalate (PET) used in polarizers produces anisotropy after stretching into a film due to its crystalline properties. This results in birefringence when light passes through PET. When white light passes through PET, the material exhibits selective light transmission, with varying transmittances for different wavelengths. The transmittance is low in the 500nm band, while high in the 450nm and 600nm bands, resulting in the rainbow pattern.

[0041] To this end, the present application provides a polarizer, a method for preparing the same, and a display panel to solve the above problems.

[0042] Please refer to Figures 1 to 3. Figure 1 is a schematic cross-sectional view of a polarizer provided in an embodiment of the present application. Figure 2 is a schematic cross-sectional view of a dimming film provided in an embodiment of the present application. Figure 3 is a schematic cross-sectional view of a display panel provided in an embodiment of the present application. Referring to Figure 1, the polarizer 20 includes a protective layer 21 and a polarizing film 22. The protective layer 21 is disposed on one side of the polarizing film 22. A concave-convex structure 301 is provided on the side of the protective layer 21 away from the polarizing film 22. The concave-convex structure 301 includes a plurality of concave-convex sub-surfaces 310 of varying shapes and / or sizes.

[0043] In this embodiment, a concave-convex structure 301 is provided on the side of the protective layer 21 away from the polarizing film 22, so that when the light directed toward the polarizer 20 passes through the concave-convex structure 301, the light will be evenly scattered based on the principle of diffuse reflection. When the evenly scattered light passes through the protective layer 21 of the polarizer 20 again, the light intensity energy of each wavelength is evenly dispersed, thereby avoiding the occurrence of the rainbow pattern phenomenon, and solving the technical problem of the rainbow pattern phenomenon in existing display devices.

[0044] Optionally, referring again to FIG. 1 , the polarizer 20 further includes a dimming film 30 disposed on a side of the protective layer 21 away from the polarizing film 22. One side of the dimming film 30 includes the concave-convex structure 301. That is, the concave-convex structure 301 on the side of the protective layer 21 away from the polarizing film 22 is formed by the dimming film 30. The dimming film 30 can be directly fabricated on the protective layer 21 of the polarizer 20, or directly bonded to the protective layer 21 of the polarizer 20.

[0045] The dimming film 30 has a concave-convex structure 301, which is located on the side of the dimming film 30 away from the protective layer 21. The concave-convex structure 301 includes a plurality of irregular concave-convex sub-surfaces 310, each of which has different shapes and / or sizes. The "irregular" in the plurality of irregular concave-convex sub-surfaces 310 means that the shape and arrangement of each concave-convex sub-surface 310 do not have a fixed pattern, for example, each of the concave-convex sub-surfaces 310 has a different shape and / or size. The "size" can refer to the height of the concave-convex sub-surface from the protective layer 21 and the area of ​​the concave-convex sub-surface 310.

[0046] The structure of the dimming film 30 will be described in detail below:

[0047] 1 and 2 , the dimming film 30 includes a substrate layer 31 and first diffusion particles 32 dispersed in the substrate layer 31 . At least some of the first diffusion particles 32 protrude from the surface of the dimming film 30 away from the protective layer 21 to form the concave-convex structure 301 .

[0048] Furthermore, the dimming film 30 further includes second diffusing particles 33 dispersed within the substrate layer 31. The second diffusing particles 33 and the first diffusing particles 32 protrude from the same side of the dimming film 30. Some of the first diffusing particles 32 are located on a side of the second diffusing particles 33 away from the concave-convex structure 301. The ratio of the first diffusing particles 32 to the second diffusing particles 33 is 7:3.

[0049] The second diffusing particles 33 have a smaller particle size than the first diffusing particles 32. For example, the particle size of the first diffusing particles 32 ranges from 2 microns to 3 microns, such as 2 microns, 2.1 microns, 2.2 microns, 2.6 microns, 2.8 microns, or 3 microns. The particle size of the second diffusing particles 33 ranges from 30 nanometers to 70 nanometers, such as 30 nanometers, 40 nanometers, 50 nanometers, 60 nanometers, or 70 nanometers. Optionally, the first diffusing particles 32 include polymethyl methacrylate (PMMA) particles, and the second diffusing particles 33 include at least one of silica particles, titanium dioxide particles, and zinc dioxide particles. The substrate layer 31 includes a UV-curable resin substrate, such as an epoxy acrylate oligomer or a polyurethane acrylate oligomer, with a molecular weight ranging from several hundred to tens of thousands.

[0050] The first diffusing particles 32 and the substrate layer 31 are made of different materials and will not dissolve in the same system. This results in the first diffusing particles 32 being randomly distributed within the substrate layer 31. Some of the first diffusing particles 32 are distributed on the side of the substrate layer 31 away from the protective layer 21 and protrude from the surface of the dimming film 30 away from the protective layer 21, forming the concave-convex structure 301. Meanwhile, some of the first diffusing particles 32 are distributed on the side of the substrate layer 31 closer to the protective layer 21 and are completely encapsulated by the substrate layer 31. Because the distribution and number of the first diffusing particles 32 at different locations are random and not fixed, the concave-convex structure 301 formed by the dimming film 30 is also irregular.

[0051] Similarly, the second diffusing particles 33 and the substrate layer 31 are made of different materials and will not dissolve in the same system. This results in a random distribution of the second diffusing particles 33 within the substrate layer 31. Some of the second diffusing particles 33 are located on the side of the substrate layer 31 away from the protective layer 21. Like the first diffusing particles 32, these particles protrude from the surface of the dimming film 30 away from the protective layer 21, forming the concave-convex structure 301. Furthermore, the distribution positions and number of the second diffusing particles 33 at different locations are random and not fixed, resulting in an irregular pattern in the concave-convex structure 301 formed by the dimming film 30.

[0052] The density of the first diffusion particles 32 is greater than the density of the second diffusion particles 33, so that the first diffusion particles 32 are easier to deposit than the second diffusion particles 33. That is, the number of particles in the first diffusion particles 32 away from the concave-convex structure 301 is greater than the number of particles in the second diffusion particles 33 away from the concave-convex structure 301, so that some of the first diffusion particles 32 are located on the side of the second diffusion particles 33 away from the concave-convex structure 301.

[0053] Furthermore, the particle size of the first diffusing particles 32 is larger than that of the second diffusing particles 33, making it easier for the second diffusing particles 33 to aggregate on the surface of the substrate layer 31 to form large clusters, thereby forming the concave-convex structure 301. Furthermore, due to the smaller particle size of the second diffusing particles 33, the aggregation of multiple second diffusing particles 33 can form a greater variety of concave-convex structures 301, allowing the second diffusing particles 33 to cooperate with the first diffusing particles 32 to better form the irregular concave-convex structure 301. Furthermore, the combination of the first diffusing particles 32 and the second diffusing particles 33 can enhance the subjective visual experience of dark images when the polarizer 20 is used in a display panel, resulting in a bluer appearance.

[0054] The concave-convex structure 301 is composed of a plurality of concave-convex sub-surfaces 310. The plurality of concave-convex sub-surfaces 310 are spliced ​​and combined to form the concave-convex structure 301. An irregular concave-convex structure 301 is composed of a plurality of irregular concave-convex sub-surfaces 310. The irregularity of the concave-convex sub-surface 310 can be measured by the angle between the normal of the concave-convex sub-surface 310 and a plane parallel to the plane of the protective layer 21. For example, the angle between the normal of the concave-convex sub-surface 310 and a plane parallel to the plane of the protective layer 21 is distributed within a range of 0 degrees to 180 degrees. Specifically, a straight line in a plane parallel to the plane where the protective layer 21 is located can be taken as a reference line, and the reference line is defined as a horizontal line, as shown in Figure 2, H represents the horizontal line, ON represents the normal line of the concave-convex sub-surface 310, TL represents the tangent line of the concave-convex sub-surface 310, the normal line ON is perpendicular to the tangent line TL, and a is the angle between the normal line ON of the concave-convex sub-surface 310 and the horizontal line H. The angle a between the normal ON of the concave-convex sub-surface 310 and the horizontal line H is distributed between 0 degrees and 180 degrees. For example, the angle a includes integer angles such as 0 degrees, 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees, 80 degrees, 90 degrees, 100 degrees, 110 degrees, 120 degrees, 130 degrees, 140 degrees, 150 degrees, 160 degrees, 170 degrees, and 180 degrees. Of course, the angle a can also include non-integer angles, such as 33.6 degrees, 62.8 degrees, 121.9 degrees, etc.

[0055] Furthermore, the haze of the polarizer 20 ranges from 20% to 70%, for example, 20%, 30%, 40%, 50%, 60%, 70%, etc. The haze of the polarizer 20 is primarily determined by the state of the concave-convex structure 301 on the dimming film 30. Therefore, the haze of the polarizer 20 can be used as another indicator to measure the irregular state of the concave-convex structure 301 of the dimming film 30. The haze of the polarizer 20 refers to the percentage of the total transmitted light intensity of the light emitted from the polarizer 20 that deviates by an angle of more than 2.5°.

[0056] It should be noted that this embodiment illustrates the dimming film as including the first and second diffuser particles 32 and 33 dispersed within the substrate layer 31. However, the present application is not limited thereto. The dimming film 30 of the present application may also include more or fewer types of diffuser particles within the substrate layer 31, for example, one, three, four, or five types of diffuser particles. In one embodiment, the substrate layer 31 includes a single type of diffuser particle, such as the first diffuser particles 32. The larger particle size of the first diffuser particles 32 facilitates formation of the concave-convex structure 301 and allows for easier adjustment of the desired haze parameter of the polarizer 20 based on the particle count. Furthermore, because the larger particle size of the first diffuser particles 32 facilitates formation of the concave-convex structure 301, when the dimming film 30 includes both the first and second diffuser particles 32 and 33, the number of the first diffuser particles 32 can be greater than the number of the second diffuser particles 33, for example, a ratio of 7:3 between the first and second diffuser particles 32 and 33.

[0057] The polarizer 20 described above can be applied to a display panel, which includes a liquid crystal display panel, etc. The embodiment of the present application takes the liquid crystal display panel as an example for description.

[0058] Specifically, referring to Figure 3 , the display panel 100 includes a backlight module 10 and a liquid crystal cell 40 disposed opposite the backlight module 10. The polarizer 20 is disposed on a side of the liquid crystal cell 40 that is close to the backlight module 10, and the dimming film 30 is located on a side of the protective layer 21 that is close to the backlight module 10. Of course, the display panel 100 also includes an upper polarizer 50 located on a side of the liquid crystal cell 40 that is away from the backlight module 10.

[0059] The backlight module 10 includes a backlight source 11, a back panel 12, and an optical film such as a diffusion film 13. The backlight source 11 is fixed on the back panel 12, and the diffusion film 13 is arranged in the light emitting direction of the backlight source 11. The back panel 12 can be made of metal, such as iron or other metals. Of course, the back panel 12 can also be made of alloy material. In some other examples of this embodiment, the back panel 12 can also be made of plastic. Of course, an outer frame formed by combining plastic and metal is also feasible, for example, the currently more widely used integrated iron-plastic frame.

[0060] The backlight 11 includes a light source such as an LED or mini LED. The diffusion film 13 is primarily used to evenly distribute the light emitted by the backlight 11 at all angles, thereby increasing the display uniformity of the display panel 100. Of course, the backlight module 10 may also include a reflective sheet disposed between the backlight 11 and the backplate 12. The reflective sheet is primarily used to increase the light utilization rate of the backlight 11, thereby increasing the brightness and energy efficiency of the display panel 100.

[0061] The liquid crystal cell 40 includes an array substrate 41 and an opposing substrate 42 that are disposed opposite to each other, and a liquid crystal layer 43 disposed between the array substrate 41 and the opposing substrate 42 .

[0062] The polarizer 20 is disposed on the side of the liquid crystal cell 40 closest to the backlight module 10, and the dimming film 30 is disposed on the side of the protective layer 21 closest to the backlight source 11, with the concave-convex structure 301 on the dimming film 30 located on the side of the dimming film 30 closest to the backlight source 11. The polarizer 20 also includes a compensation layer 23 and an adhesive layer 24 laminated on the side of the polarizing film 22 away from the protective layer 21. The protective layer 21 is made of polyethylene terephthalate (PET). The protective layer 21 protects the polarizing film 22 from corrosion by water and oxygen. The polarizing film 22 is made of polyvinyl alcohol (PVA), and the adhesive layer 24 is preferably made of a pressure-sensitive adhesive (PSA). The polarizer 20 is adhered to one side of the array substrate 41 of the liquid crystal cell 40 via the adhesive layer 24.

[0063] The structure of the upper polarizer 50 is the same as that of the polarizer 20, but the upper polarizer 50 does not include the dimming film 30. The upper polarizer 50 can be attached to one side of the counter substrate 42 of the liquid crystal cell 40 via an adhesive layer on the upper polarizer 50.

[0064] In one embodiment, referring to Figures 1 to 4 , Figure 4 is a schematic cross-sectional view of another display panel structure provided in an embodiment of the present application. Unlike the above embodiment, in the display panel 101 of this embodiment, the dimming film 30 has a concave-convex structure 301 on the side adjacent to the protective layer 21 . The dimming film 30 includes a substrate layer 31 and first diffusion particles 32 dispersed within the substrate layer 31 . At least some of the first diffusion particles 32 protrude from the surface of the dimming film 30 adjacent to the protective layer 21 , forming the concave-convex structure 301 .

[0065] Optionally, the dimming film 30 may further include a substrate 34, with the base material layer 31 disposed on a side of the substrate 34 adjacent to the protective layer 21. The substrate 34 may be a glass substrate, for example. Of course, the dimming film 30 of the present application may also not include the substrate 34. For example, after the dimming film 30 is prepared on the substrate 34, the dimming film 30 may be laminated to the protective layer 21 and the substrate 34 may be removed. For other explanations, please refer to the above embodiment and will not be repeated here.

[0066] In one embodiment, referring to Figures 1 to 7 , Figure 5 is a schematic diagram of another cross-sectional structure of a display panel provided in an embodiment of the present application, Figure 6 is a schematic diagram of light propagation when the display panel provided in an embodiment of the present application does not include a dimming film, and Figure 7 is a schematic diagram of light propagation when the display panel provided in an embodiment of the present application includes a dimming film. Unlike the above-described embodiments, in the display panel 102 of this embodiment, the backlight module 10 also includes a quantum dot film 14 and a brightness enhancement film 15, as shown in Figure 5 .

[0067] The quantum dot film 14 is disposed in the light emitting direction of the backlight source 11, the diffusion film 13 is disposed on a side of the quantum dot film 14 away from the back plate 12, and the brightness enhancement film 15 is disposed on a side of the diffusion film 13 away from the back plate 12. Of course, the present application is not limited thereto, and the quantum dot film 14 of the present application may also be disposed between the diffusion film 13 and the brightness enhancement film 15, or on a side of the brightness enhancement film 15 away from the diffusion film 13.

[0068] By setting the quantum dot film 14 and cooperating with the Mini LED backlight source 11, QD-Mini LED backlight technology can be adopted. QD-Mini LED backlight technology can use local dimming to achieve regional light control, achieve ultra-high contrast, and improve the color gamut of the display panel 102.

[0069] Referring to Figure 6, however, since the QD-Mini LED backlight technology is equipped with the brightness enhancement film 15 added to the backlight module 10, the light emitted from the backlight source 11 is all linearly polarized light. When the linearly polarized light passes through the protective layer 21 of the polarizer 20, due to the birefringence of the PET of the protective layer 21, the linearly polarized light will change its polarization state after passing through the PET, becoming elliptically polarized light or circularly polarized light, and different wavelengths of light will form outgoing light with different polarization states after passing through the PET. When light of different wavelengths passes through the polarizing film 22 again, the light intensity energy that can be emitted by light of different wavelengths is different, resulting in a difference in light intensity energy, and a large difference in light transmittance, which in turn exacerbates the rainbow pattern phenomenon. In particular, the light intensity of the QD-Mini LED backlight in the 620 nm to 700 nm band is stronger than that of the traditional D65 light source. Combined with the birefringence characteristics of PET itself, the transmitted light intensity in the red light band is greater, thereby causing the red rainbow pattern phenomenon in human vision.

[0070] The polarizer 20 of the present application can effectively solve the rainbow pattern phenomenon that occurs in the QD-Mini LED backlight technology by arranging a dimming film 30 with a concave-convex structure 301 on the side of the protective layer 21 close to the backlight source 11.

[0071] Specifically, referring to Figure 7 , after the light emitted from the backlight source 11 passes through the quantum dot film 14, it then passes through the irregular concave-convex structure 301 of the dimming film 30. Based on the principle of diffuse reflection, the light is diffused. The concave-convex structure 301 can convert linearly polarized light into partially polarized light, so that the light emitted from the dimming film 30 is no longer linearly polarized light. Furthermore, the light is evenly dispersed, effectively diffusing the light intensity energy and making the light intensity energy distribution of the light emitted from the dimming film 30 more uniform. When the partially polarized light emitted from the dimming film 30 passes through the protective layer 21, the polarization state does not change. When light of different wavelengths passes through the polarizing film 22, the light of different wavelengths can be emitted with the same light intensity energy, resulting in a uniform light intensity energy distribution for each wavelength, thereby preventing the occurrence of rainbow stripes.

[0072] It should be noted that Figures 6 and 7 merely illustrate the direction of light propagation and the state of light after passing through different film layers. To clearly illustrate the direction and state of light after passing through different film layers, the approximate positional relationships of the film layers are simply shown and do not represent the actual film layer structure. Furthermore, the arrowed lines in Figures 6 and 7 represent the direction of light propagation, while the inclined lines, circles, and ellipses represent the state of light. For other explanations, please refer to the above embodiments and will not be repeated here.

[0073] Based on the same inventive concept, the present application also provides a method for preparing a polarizer. The method can be used to prepare the polarizer of one of the above embodiments. The polarizer produced by the method can be applied to the display panel of one of the above embodiments. Specifically, please refer to Figures 1 to 8. Figure 8 is a flow chart of the method for preparing a polarizer provided in the present application. Referring to Figure 8, the method for preparing a polarizer includes the following steps:

[0074] S201: attaching a protective layer 21 to one side of the polarizing film 22;

[0075] Specifically, referring to Figures 1 and 3 , the protective layer 21 is attached to one side of the polarizing film 22, and the compensation layer 23 and adhesive layer 24 are attached to the side of the polarizing film 22 away from the protective layer 21. The protective layer 21 is made of polyethylene terephthalate (PET). It protects the polarizing film 22 from corrosion caused by water and oxygen. The polarizing film 22 is made of polyvinyl alcohol (PVA), and the adhesive layer 24 is preferably made of a pressure-sensitive adhesive (PSA).

[0076] S202 : preparing a concave-convex structure 301 on a side of the protective layer 21 away from the polarizing film 22 , wherein the concave-convex structure 301 includes a plurality of concave-convex sub-surfaces 310 of different shapes and / or sizes.

[0077] Specifically, the step of preparing a concave-convex structure 301 on the side of the protective layer 21 away from the polarizing film 22 includes:

[0078] The UV-curable resin, UV-curable monomer, first diffusion particles 32, and second diffusion particles 33 are mixed in a solvent to form a dimming solution. More specifically, the UV-curable resin, UV-curable monomer, first diffusion particles 32, second diffusion particles 33, a photoinitiator, and other additives are mixed in a solvent to form the dimming solution.

[0079] The UV-curable resin includes, for example, epoxy acrylate oligomers or polyurethane acrylate oligomers with molecular weights ranging from several hundred to tens of thousands. The UV-curable monomer includes at least one of trimethylolpropane triacrylate (TMPTA), pentaerythritol triacrylate (PETA), and dipentaerythritol hexaacrylate (DPHA).

[0080] The photoinitiator includes at least one of a benzophenone photoinitiator and a thioxanthone photoinitiator, with the proportion of the photoinitiator ranging from 1% to 4%. Other additives include thickeners, leveling agents, and antistatic agents, with the proportion of other additives ranging from 0.1% to 1%. The thickener is used to adjust the product viscosity, the leveling agent is used to improve the product appearance, and the antistatic agent is used to reduce the surface resistance of the coating. The solvent includes ketone solvents, alcohol solvents, lipid solvents, ether solvents, etc.

[0081] The first diffusing particles 32 include polymethyl methacrylate particles with a particle size of 2 to 3 microns, and the second diffusing particles 33 include at least one of inorganic silica particles, titanium dioxide particles, and zinc dioxide particles with a particle size of 30 to 70 nanometers. The mass fraction of the first diffusing particles 32 and the second diffusing particles 33 in the dimming solution ranges from 2.5% to 20%. If the mass fraction of the first diffusing particles 32 and the second diffusing particles 33 is small, the resulting dimming film 30 may have poor haze performance, which in turn may affect the haze performance of the polarizer 20, thus affecting the ability to reduce rainbow patterns. If the mass fraction of the first diffusing particles 32 and the second diffusing particles 33 is large, the resulting polarizer 20 may diffuse light excessively when applied to the display panel 100, resulting in a decrease in contrast and transmittance of the display panel 100. Optionally, the ratio of the first diffusing particles 32 to the second diffusing particles 33 is 7:3.

[0082] Applying the dimming solution on the side of the protective layer 21 away from the polarizing film 22;

[0083] Specifically, the dimming solution is coated on the side of the protective layer 21 away from the polarizing film 22 by using a coating process such as wet coating.

[0084] The dimming solution is cured to form a dimming film, with the concavo-convex structure 301 formed on one side of the dimming film. Specifically, the dimming solution applied to one side of the protective layer 21 is cured, so that the UV-curable resin forms a substrate layer 31. The first diffusion particles 32 and the second diffusion particles 33 are dispersed within the substrate layer 31. At least a portion of the first diffusion particles 32 protrude from a surface of the substrate layer 31 away from the protective layer 21 to form the concavo-convex structure 301. The second diffusion particles 33 protrude from the same side of the substrate layer 31 as the first diffusion particles 32, and a portion of the first diffusion particles 32 is located on a side of the second diffusion particles 33 away from the concavo-convex structure 301, thereby forming the dimming film 30, as shown in FIG2 .

[0085] In another embodiment, in step S202, the step of preparing a concave-convex structure 301 on the side of the protective layer 21 away from the polarizing film 22 can also be achieved by the following method:

[0086] The photolithography etching process etches the side of the protective layer 21 away from the polarizing film 22 to form the concave-convex structure 301. That is, by etching directly on one side of the protective layer 21, the concave-convex structure 301 is formed directly on the protective layer 21. For other explanations, please refer to the above embodiment and will not be repeated here.

[0087] In another embodiment, in step S202, the step of preparing a concave-convex structure 301 on the side of the protective layer 21 away from the polarizing film 22 can also be achieved by the following method:

[0088] 4 , the dimming solution is coated on a substrate 34 and cured to form a dimming film 30. The dimming film 30 has the concave-convex structure 301 formed on the side away from the substrate 34. Specifically, the dimming solution coated on one side of the substrate 34 is cured, so that the UV-curable resin forms a base layer 31. The first diffusion particles 32 and the second diffusion particles 33 are dispersed within the base layer 31. At least a portion of the first diffusion particles 32 protrude from the surface of the base layer 31 away from the substrate 34 to form the concave-convex structure 301. The second diffusion particles 33 protrude from the same side of the base layer 31 as the first diffusion particles 32. A portion of the first diffusion particles 32 is located on the side of the second diffusion particles 33 away from the concave-convex structure 301, thereby forming the dimming film 30, as shown in FIG4 .

[0089] After forming the dimming film 30, the dimming film 30 is attached to the side of the protective layer 21 away from the polarizing film 22. Of course, the dimming film 30 of the present application may also not include the substrate 34. For example, after the dimming film 30 is prepared on the substrate 34, the dimming film 30 is attached to the protective layer 21 and the substrate 34 is removed.

[0090] According to the above embodiments, it can be seen that:

[0091] The present application provides a polarizer, a preparation method thereof, and a display panel. The polarizer includes a polarizing film, a protective layer, and a dimming film. The protective layer is arranged on one side of the polarizing film, and the dimming film is arranged on a side of the protective layer away from the polarizing film. The dimming film has a concave-convex structure, and the concave-convex structure includes multiple concave-convex sub-surfaces of different shapes and / or sizes. The present application arranges a dimming film with a concave-convex structure on a side of the protective layer away from the polarizing film, so that when light directed toward the polarizer passes through the concave-convex structure of the dimming film, the light will be evenly scattered based on the principle of diffuse reflection. When the evenly scattered light passes through the protective layer again, the light intensity energy of each wavelength is evenly dispersed, thereby avoiding the occurrence of rainbow stripes, thereby solving the technical problem of rainbow stripes in existing display devices.

[0092] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0093] The above is a detailed introduction to the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents. However, these 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 application.

Claims

1. A polarizer, comprising: polarizing film; as well as A protective layer, disposed on one side of the polarizing film; Wherein, a concave-convex structure is provided on a side of the protective layer away from the polarizing film, and the concave-convex structure includes a plurality of concave-convex sub-surfaces of different shapes and / or sizes.

2. The polarizer according to claim 1, wherein: The polarizer further comprises a dimming film arranged on a side of the protective layer away from the polarizing film, and one side of the dimming film has the concave-convex structure.

3. The polarizer according to claim 2, wherein: The side of the dimming film away from the protective layer has the concave-convex structure; The dimming film includes a substrate layer and first diffusion particles dispersed in the substrate layer. At least part of the first diffusion particles protrude from a surface of the dimming film away from the protective layer to form the concave-convex structure.

4. The polarizer according to claim 2, wherein: The dimming film has the concave-convex structure on one side close to the protective layer; The dimming film includes a substrate layer and first diffusion particles dispersed in the substrate layer. At least part of the first diffusion particles protrude from a surface of the dimming film close to the protective layer to form the concave-convex structure.

5. The polarizer according to claim 3, wherein: The dimming film further includes second diffusion particles dispersed in the substrate layer. The second diffusion particles and the first diffusion particles protrude from the same side surface of the dimming film. At least part of the first diffusion particles are located on a side of the second diffusion particles away from the concave-convex structure.

6. The polarizer according to claim 5, wherein: The particle size of the first diffusion particles is larger than the particle size of the second diffusion particles.

7. The polarizer according to claim 6, wherein: The substrate layer includes an ultraviolet-curable resin substrate, the first diffusion particles include polymethyl methacrylate particles, and the second diffusion particles include at least one of silicon dioxide particles, titanium dioxide particles, and zinc dioxide particles.

8. The polarizer according to claim 2, wherein: The haze of the polarizer ranges from 20% to 70%.

9. The polarizer according to claim 1, wherein: The angles between the normal lines of the plurality of concavo-convex sub-surfaces and a plane parallel to the plane where the protective layer is located are distributed in the range of 0 degrees to 180 degrees.

10. A method for preparing a polarizer, comprising: A protective layer is attached to one side of the polarizing film; as well as A concave-convex structure is prepared on a side of the protective layer away from the polarizing film, wherein the concave-convex structure comprises a plurality of concave-convex sub-surfaces with different shapes and / or sizes.

11. The method for preparing a polarizer according to claim 10, wherein: The step of preparing a concave-convex structure on a side of the protective layer away from the polarizing film comprises: Mixing ultraviolet curing resin, ultraviolet curing monomer and first diffusion particles in a solvent to form a dimming solution; Applying the dimming solution on a side of the protective layer away from the polarizing film; The dimming solution is solidified to form a dimming film, and the concave-convex structure is formed on one side of the dimming film.

12. The method for preparing a polarizer according to claim 11, wherein: The dimming solution also includes second diffusion particles, the particle size of the second diffusion particles is smaller than that of the first diffusion particles; the second diffusion particles include inorganic silicon dioxide particles with a particle size of 30 nanometers to 70 nanometers, and the first diffusion particles include polymethyl methacrylate particles with a particle size of 2 micrometers to 3 micrometers.

13. The method for preparing a polarizer according to claim 12, wherein: The mass fraction of the first diffusion particles and the second diffusion particles in the dimming solution ranges from 2.5% to 20%, wherein the ratio of the first diffusion particles to the second diffusion particles is 7:

3.

14. A display panel comprising a polarizer, wherein the polarizer comprises: polarizing film; as well as A protective layer, disposed on one side of the polarizing film; Wherein, a concave-convex structure is provided on a side of the protective layer away from the polarizing film, and the concave-convex structure includes a plurality of concave-convex sub-surfaces of different shapes and / or sizes.

15. The display panel according to claim 14, wherein: The polarizer further comprises a dimming film arranged on a side of the protective layer away from the polarizing film, and one side of the dimming film has the concave-convex structure.

16. The display panel according to claim 15, wherein: The side of the dimming film away from the protective layer has the concave-convex structure; The dimming film includes a substrate layer and first diffusion particles dispersed in the substrate layer. At least part of the first diffusion particles protrude from a surface of the dimming film away from the protective layer to form the concave-convex structure.

17. The display panel according to claim 15, wherein: The dimming film has the concave-convex structure on one side close to the protective layer; The dimming film includes a substrate layer and first diffusion particles dispersed in the substrate layer. At least part of the first diffusion particles protrude from a surface of the dimming film close to the protective layer to form the concave-convex structure.

18. The display panel according to claim 16, wherein: The dimming film further includes second diffusion particles dispersed in the substrate layer. The second diffusion particles and the first diffusion particles protrude from the same side surface of the dimming film. At least part of the first diffusion particles are located on a side of the second diffusion particles away from the concave-convex structure.

19. The display panel according to claim 15, wherein: The haze of the polarizer ranges from 20% to 70%.

20. The display panel according to claim 14, wherein: The angles between the normal lines of the plurality of concavo-convex sub-surfaces and a plane parallel to the plane where the protective layer is located are distributed in the range of 0 degrees to 180 degrees.

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