Polarization composite film, backlight module and display equipment

Abstract

The invention discloses a polarization composite film, a backlight module and display equipment, relates to the technical field of display, and discloses the polarization composite film which comprises a polarization film and at least one brightness enhancement film which are arranged in a stacked mode. The polarizing film comprises a main polarizing layer and at least one compensation polarizing layer; the compensation polarization layer comprises a first compensation layer, and the main polarization layer is arranged between the first compensation layer and the brightness enhancement film; a weather-resistant dichroic dye is added to the compensation polarization layer. According to the liquid crystal display panel, the situation that the lower polarizing film of the liquid crystal display panel is scratched by the optical film of the backlight module can be effectively avoided.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and in particular, to a polarization composite film, a backlight module, and a display device. Background Art

[0002] The backlight module is one of the key components in liquid crystal display technologies, mainly composed of a light source, a light guide plate, a reflector, a diffuser, an optical film, etc. Among them, the diffuser plate is located on the light-emitting side of the light guide plate and is used to convert the uneven light source emitted from the light guide plate into a uniformly distributed surface light source, and the optical film is located on the light-emitting side of the diffuser plate and is used to further improve the uniformity and brightness of the light. The liquid crystal panel in the display device is located on the light-emitting side of the backlight module, and its lower polarizing film is adjacent to the optical film of the backlight module and is used to convert the light beam generated by the backlight source into polarized light so that the liquid crystal panel can display normally.

[0003] However, the diffuser plate and the optical film in the backlight module usually lack effective fixing measures, which makes them have a large movement space during transportation. The surface hardness of the optical film is usually 1-2HB, while the hardness of the lower polarizing film of the liquid crystal panel is usually 8-10B, and the hardness difference between the two is huge. Therefore, during transportation, the optical film is extremely likely to come into slapping contact with the lower polarizing film of the liquid crystal panel, resulting in the lower polarizing film being scratched, and further causing quality accidents.

[0004] The above content is only used to assist in understanding the technical solution of the present application, and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of the present application is to provide a polarization composite film, a backlight module, and a display device, which can effectively avoid the situation that the lower polarizing film of the liquid crystal panel is scratched by the optical film of the backlight module.

[0006] To achieve the above object, the present application provides a polarization composite film, which includes a polarizing film and at least one brightness enhancement film stacked;

[0007] The polarizing film includes a main polarization layer and at least one compensation polarization layer;

[0008] The compensation polarization layer includes a first compensation layer, and the main polarization layer is disposed between the first compensation layer and the brightness enhancement film;

[0009] The compensation polarization layer is added with a weather-resistant dichroic dye.

[0010] In one embodiment, the weather-resistant dichroic dye includes at least one of azo dyes, polycyclic dyes, azo metal complex dyes, triphenylmethane dyes, and naphthoquinone dyes;

[0011] The material of the compensation polarization layer includes PVA.

[0012] In one embodiment, the compensation polarization layer further includes a second compensation layer, and the second compensation layer is disposed between the main polarization layer and the brightness enhancement film.

[0013] In one embodiment, the polarization film is made by unidirectional stretching, and the direction of the unidirectional stretching is perpendicular to the absorption axis of the polarizing film on the light-emitting side of the liquid crystal panel.

[0014] In one embodiment, the stretching multiple of the unidirectional stretching is 3 to 5 times.

[0015] In one embodiment, the polarization composite film further includes an adhesive layer, a triangular prism array structure is disposed on one side of the light-emitting surface of the brightness enhancement film, and the adhesive layer is disposed between the polarization film and the triangular prism array structure.

[0016] In one embodiment, diffusion particles are added to the adhesive layer.

[0017] In addition, to achieve the above object, an embodiment of the present application further provides a backlight module, and the backlight module includes the polarization composite film as described above.

[0018] In addition, to achieve the above object, an embodiment of the present application further provides a display device, and the display device includes the polarization composite film as described above.

[0019] In one embodiment, the display device includes: a backlight module and a liquid crystal panel;

[0020] The polarization composite film is disposed on the light-emitting side of the backlight module;

[0021] The liquid crystal panel includes a first glass substrate, a thin film transistor, a liquid crystal layer, a filter film, a second glass substrate, and a polarizing film that are sequentially stacked from the light-incident direction to the light-emitting direction.

[0022] One or more technical solutions proposed in the embodiments of the present application have at least the following technical effects: A polarization composite film is provided, including: a polarization film and at least one brightness enhancement film arranged in a stacked manner. The polarization film includes a main polarization layer and at least one compensation polarization layer. Among them, the compensation polarization layer is added with a weather-resistant dichroic dye and includes a first compensation layer, and the main polarization layer is arranged between the first compensation layer and the brightness enhancement film. High polarization degree is achieved through the main polarization layer, and the compensation polarization layer arranged on one side of the main polarization layer is added with a weather-resistant dichroic dye. Although the polarization property of the compensation polarization layer is relatively slightly weaker, its ability to withstand high temperature and high humidity is improved. Therefore, it can replace the TAC layer to protect the main polarization layer; further, at least one brightness enhancement film is arranged on the other side of the main polarization layer, which can not only achieve brightness gain but also replace the TAC layer to protect the main polarization layer, so that the polarization composite film has optical properties of first condensing light and then polarizing, effectively reducing the cost of the polarization film. At the same time, due to the polarization composite film having optical properties of first condensing light and then polarizing, it can therefore replace the optical film of the backlight module and the lower polarizing film (i.e., the polarizing film close to the light incident side of the liquid crystal panel) of the liquid crystal panel in the display device at the same time, thus effectively avoiding the occurrence of the situation where the lower polarizing film of the liquid crystal panel is scratched by the optical film of the backlight module. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Structural schematic diagram of the polarization composite film related to the embodiments of the present application Figure 1 ;

[0024] Figure 2 Schematic diagram of the PVA molecular chain related to the embodiments of the present application;

[0025] Figure 3 Schematic diagram of unidirectional stretching of the polarization film related to the embodiments of the present application;

[0026] Figure 4 Schematic diagram of the polarization principle of the polarization film related to the embodiments of the present application;

[0027] Figure 5 Structural schematic diagram of the polarization composite film related to the embodiments of the present application Figure 2 ;

[0028] Figure 6 Structural schematic diagram of the polarization composite film related to the embodiments of the present application Figure 3 ;

[0029] Figure 7 Structural schematic diagram of the display device related to the embodiments of the present application;

[0030] Figure 8 Structural schematic diagram of the liquid crystal panel related to the embodiments of the present application;

[0031] Figure 9It is a schematic structural diagram of a conventional display device;

[0032] Figure 10 It is a schematic structural diagram of a conventional liquid crystal panel.

[0033] Description of reference numerals

[0034] 10. Backlight module; 101. Polarization composite film; 102. Diffusion plate; 103. Optical film;

[0035] 110. Brightness enhancement film; 111. Prism array structure;

[0036] 120. Polarizing film; 121. Main polarization layer;

[0037] 122. First compensation layer; 123. Second compensation layer; 130. Adhesive layer;

[0038] 20. Liquid crystal panel; 210. First glass substrate; 220. Thin film transistor;

[0039] 230. Liquid crystal layer; 240. Filter film; 250. Second glass substrate;

[0040] 260. First polarizing film; 270. Second polarizing film.

[0041] The realization of the purpose, functional features and advantages of this application will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0042] To make the purpose, technical solutions and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can all be obtained as conventional products through commercial purchase.

[0043] Hereinafter, the embodiments of the polarization composite film, backlight module and display device of this application specifically disclosed will be described in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the accompanying drawings and the following description are provided for those skilled in the art to fully understand this application, and are not intended to limit the subject matter described in the claims.

[0044] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include or exclude the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a specific parameter, ranges of 60 to 110 and 80 to 120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise specified, the numerical range "a to b" represents an abbreviated representation of any real number combination between a and b, where both a and b are real numbers. For example, the numerical range "0 to 5" means that all real numbers between "0 to 5" are fully listed herein, and "0 to 5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0045] If there is no special instruction, all embodiments and optional embodiments of this application can be combined with each other to form new technical solutions.

[0046] If there is no special instruction, all technical features and optional technical features of this application can be combined with each other to form new technical solutions.

[0047] If there is no special instruction, all steps of this application can be carried out sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) carried out sequentially, or can also include steps (b) and (a) carried out sequentially. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b), and (c), or can also include steps (a), (c), and (b), or can also include steps (c), (a), and (b), etc.

[0048] If there is no special instruction, the "including" and "comprising" mentioned in this application mean open-ended, and can also be closed-ended. For example, the "including" and "comprising" can mean that other components not listed can also be included or comprised, or can only include or comprise the listed components.

[0049] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0050] To make the above objects, features, and advantages of this application more obvious and understandable, the technical solutions of this application will be further described below in conjunction with the accompanying drawings and embodiments. However, this application is not limited to the listed embodiments, and should also include any other well-known changes within the scope of the rights required by this application.

[0051] As used herein, the term "one embodiment" or "embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. The phrase "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0052] To better understand the technical solutions of this application, the following will be described in detail in conjunction with the accompanying drawings of the specification and specific implementation manners.

[0053] In the related art, the diffusion plate and optical film in the backlight module usually lack effective fixing measures, which makes them have a large movement space during transportation. The surface hardness of the optical film is usually 1-2HB, while the hardness of the lower polarizing film of the liquid crystal panel is usually 8-10B, and the hardness difference between the two is huge. Therefore, during transportation, the optical film is extremely likely to come into flapping contact with the lower polarizing film of the liquid crystal panel, resulting in scratches on the lower polarizing film and thus triggering quality accidents.

[0054] In this embodiment, a polarization composite film is provided. High polarization is achieved through the main polarization layer, and a weather-resistant dichroic dye is added to the compensation polarization layer provided on one side of the main polarization layer. Although the polarization of the compensation polarization layer is relatively slightly weaker, its ability to withstand high temperature and high humidity is improved. Therefore, it can replace the TAC layer to protect the main polarization layer; further, at least one brightness enhancement film is provided on the other side of the main polarization layer, which can not only achieve brightness gain but also replace the TAC layer to protect the main polarization layer, enabling the polarization composite film to have optical properties of first concentrating light and then polarizing, effectively reducing the cost of the polarizing film. At the same time, due to the optical properties of first concentrating light and then polarizing of the polarization composite film, it can therefore simultaneously replace the optical film of the backlight module and the lower polarizing film of the liquid crystal panel (i.e., the polarizing film on the light incident side close to the liquid crystal panel) in the display device, thus effectively avoiding the occurrence of the situation where the lower polarizing film of the liquid crystal panel is scratched by the optical film of the backlight module.

[0055] Based on this, in the first aspect of the embodiments of the present application, a polarization composite film 101 is provided. Referring to Figure 1 , the polarization composite film 101 includes a polarization film 120 and at least one brightness enhancement film 110 which are stacked;

[0056] The polarization film 120 includes a main polarization layer 121 and at least one compensation polarization layer;

[0057] The compensation polarization layer includes a first compensation layer 122, and the main polarization layer 121 is disposed between the first compensation layer 122 and the brightness enhancement film 110;

[0058] The compensation polarization layer is added with a weather-resistant dichroic dye.

[0059] In this embodiment, a high degree of polarization is achieved through the main polarization layer 121, and a weather-resistant dichroic dye is added to the compensation polarization layer disposed on one side of the main polarization layer 121. Although the polarization property of the compensation polarization layer is relatively weaker, its ability to withstand high temperature and high humidity is improved. Therefore, it can replace the TAC layer to protect the main polarization layer 121; further, at least one brightness enhancement film 110 is disposed on the other side of the main polarization layer 121, which can not only achieve brightness gain but also replace the TAC layer to protect the main polarization layer 121, enabling the polarization composite film 101 to have optical properties of first condensing light and then polarizing, and effectively reducing the cost of the polarization film.

[0060] In a feasible implementation manner, the material of the compensation polarization layer includes PVA. PVA has unique optical properties and processing adaptability, so it is often used in polarization films.

[0061] Optionally, the material of the main polarization layer 121 includes PVA. Since PVA has unique optical properties and processing adaptability, it can be used as the material for preparing both the compensation polarization layer and the main polarization layer at the same time.

[0062] In a feasible implementation manner, iodine is added to the main polarization layer 121. Iodine molecules can form a highly ordered arrangement structure in the main polarization layer 121. This structure enables the main polarization layer 121 to absorb the light vibration components parallel to its arrangement direction while allowing the light vibration components in the vertical direction to pass through, thereby achieving a polarization effect close to the theoretical value, with the degree of polarization reaching more than 99.9%, and the transmittance can also be maintained at about 42%.

[0063] Optionally, a weather-resistant dichroic dye is a dye with dichroism and good weather resistance. Here, the dichroism of the dye means that it has anisotropy in the absorption of visible light in the long-axis direction and short-axis direction of the molecule, which means that when light passes through this dye, its absorption of light with different polarization directions is different, thus showing different colors; and the weather resistance refers to the ability of the dye to maintain stable performance under the action of various external environmental factors. For the weather-resistant dichroic dye, it not only has the optical properties of the dichroic dye, but also has good weather resistance (for example, high temperature resistance, high humidity resistance, etc.), and can be used for a long time in various environments without easy fading or performance degradation.

[0064] In a feasible embodiment, the weather-resistant dichroic dye includes at least one of azo dyes, polycyclic dyes, azo metal complex dyes, triphenylmethane dyes, and naphthoquinone dyes.

[0065] Azo dyes are a class of synthetic organic dyes containing an azo group (-N=N-) in the molecule, and aryl structures are usually connected at both ends of the azo group. The conjugated system formed by the azo group (-N=N-) and the aromatic ring in the azo dye molecule has high chemical stability. Compared with the physical adsorption mechanism of iodine molecules (I2), azo dyes are fixed in the polymer matrix (such as PVA) through chemical bonds and are not easily dissociated or migrated due to the external environment (such as humidity and temperature changes). Moreover, azo dyes usually contain multiple benzene rings or naphthalene rings, and these rigid structures can effectively resist ultraviolet rays (UV) and thermal degradation, reducing the breakage of molecular chains. Optionally, azo dyes include Direct Red 81, Reactive Black 5, etc.

[0066] Polycyclic dyes (such as anthraquinone dyes) have high electron delocalization, can resist photooxidative degradation, and the hydrophobic aromatic rings reduce moisture absorption. Optionally, polycyclic dyes include Solvent Blue 35, Disperse Red 60, etc.

[0067] Azo metal complex dyes are rigid structures formed after metal ions (such as Cr 3+ , Co 2+ ) coordinate with the azo group. Therefore, they can inhibit molecular thermal motion and improve heat resistance. Optionally, azo metal complex dyes include Acid Black 52, Mordant Black 9, etc.

[0068] Triphenylmethane dyes are rigid planar structures with a central carbon atom connected to three aromatic rings and can absorb UV energy. Optionally, triphenylmethane dyes include Crystal Violet, Acid Blue 9, etc.

[0069] The quinone structure of naphthoquinone dyes resists degradation through redox stability and is suitable for high-temperature environments. Optionally, naphthoquinone dyes include Disperse Blue 56, etc.

[0070] In this embodiment, by adding the above-mentioned weather-resistant dichroic dye to the compensation polarization layer, although the polarization of the compensation polarization layer is slightly weaker than that of the main polarization layer 121, its high temperature and high humidity resistance is improved. Therefore, it can replace the TAC layer to protect the main polarization layer 121.

[0071] In a feasible embodiment, the polarizing film 120 is prepared by unidirectional stretching, and the unidirectional stretching direction is perpendicular to the absorption axis of the polarizing film on the light-emitting side of the liquid crystal panel. The polarization direction of the polarizing film 120 is closely related to its stretching direction, and the stretching direction determines the polarization axis direction of the polarizing film. In a liquid crystal panel, in order to display an image, the polarization axis of the polarizing film needs to match the alignment direction of the liquid crystal molecules and the control direction of the electric field. Otherwise, light cannot pass through normally, and the image cannot be displayed.

[0072] Optionally, using a PVA film as the substrate, the thickness of the PVA film is 25-80 μm. For example, the thickness of the PVA film is 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, etc. It adsorbs dye molecules (such as iodine molecules) by solution immersion, is washed and dried to obtain an iodine film. Among them, the iodine-containing solution can also be heated to 30-40 °C to accelerate the diffusion of iodine molecules. A PVA glue layer doped with a weather-resistant dichroic dye (doping concentration 8-15 wt.%) is provided on at least one surface of the iodine film. Among them, the thickness of the PVA glue layer is 3-5 μm. For example, the thickness of the PVA glue layer is 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, etc. After the film layer is dried and cured, it is unidirectionally stretched to obtain the polarizing film 120. Among them, the stretching direction, that is, the polarization light absorption axis, is perpendicular to the absorption axis of the polarizing film on the light-emitting side of the liquid crystal panel, and the curing temperature of the PVA glue layer is 25-40 °C.

[0073] Optionally, the main polarization layer 121 of the embodiment of the present application belongs to an iodine-based polarization structure, and its polarization degree can be as high as more than 99%, but its high temperature and high humidity resistance is poor, and it can only be used under environmental conditions of less than 60 °C × 90% RH × 500 Hr; while the compensation polarization layer is a weather-resistant dichroic dye-based polarization structure, its polarization degree is lower than that of the main polarization layer 121, but its high temperature and high humidity resistance is better. For example, it can work for a long time under the condition of 100 °C × 90% RH. By combining the two in the embodiment of the present application, the reliability of the polarizing film 120 and the polarization composite film 101 can be effectively improved and the polarization degrees are complementary, achieving high polarization degree and high reliability.

[0074] Optionally, PVA is a linear polymer obtained by alcoholysis of polyvinyl acetate. Many strongly polar -OH groups are evenly attached to the molecular long chain. After dye molecules, such as iodine molecule I2 and azo molecule Ar1─N=N─Ar2─N=N─Ar3, replace the -OH groups, long iodine chains and long azo chains are formed respectively, as Figure 2 shown.

[0075] Optionally, referring to Figure 3 , under normal conditions, the iodine chains and azo chains in PVA show a disordered arrangement characteristic. At this time, the polarization film 120 does not have polarization degree. When the above polarization film 120 is unidirectionally stretched and oriented by an extension process, the PVA forms a parallel arrangement in the stretching direction from the curled and disordered molecular chains. The iodine chains and azo chains (dichroic dye molecules) in the PVA also form parallel long chains accordingly. Since both iodine and azo are dichroic materials and have asymmetric electron densities when arranged neatly in the same direction, the absorption coefficients of polarized light in different directions are different. Referring to Figure 4 , if the polarization direction of the light is perpendicular to the long axis direction of the iodine molecular chain, the polarized light can pass through completely, otherwise the intensity of the transmitted light will be weakened or blocked accordingly.

[0076] In a feasible implementation manner, the stretching multiple of the unidirectional stretching is 3 to 5 times. For example, the stretching multiple of the unidirectional stretching is 3 times, 3.5 times, 4 times, 4.5 times, 5 times, etc. The stretching multiple of the unidirectional stretching has a key impact on the final performance of the polarization film 120. If the stretching multiple is too small, the orientation of the polymer chains is insufficient, which will cause the polarization degree to fail to meet the standard requirements. At the same time, the density, crystallinity and tensile strength of the material are all relatively low, and it is difficult to form an effective dichroic structure. On the contrary, if the stretching multiple is too large, although the orderliness of the molecular chains may temporarily increase the polarization degree, it will cause defects such as uneven film thickness (such as thin in the middle and thick at the edges), holes or cracks, and even lead to fracture failure; in addition, excessive stretching will significantly reduce the fracture strength and thickness of the film, which may instead weaken the polarization performance and increase the complexity of process control. Therefore, the embodiments of the present application determine that the stretching multiple of the unidirectional stretching is 3 to 5 times.

[0077] In a feasible implementation manner, referring to Figure 5 , the compensation polarization layer further includes a second compensation layer 123, and the second compensation layer 123 is disposed between the main polarization layer 121 and the brightness enhancement film 110.

[0078] Optionally, the compensation polarization layer includes a first compensation layer 122 and a second compensation layer 123, and weather-resistant dichroic dyes are added to both the first compensation layer 122 and the second compensation layer 123; although the weather-resistant dichroic dyes make the polarization of the first compensation layer 122 and the second compensation layer 123 relatively weaker, their weather resistance (e.g., the ability to withstand high temperature and high humidity) is improved, so they can replace the TAC layer to achieve the protection effect on the main polarization layer 121.

[0079] Optionally, the polarizing film 120 includes a second compensation layer 123, a main polarization layer 121, and a first compensation layer 122 arranged in sequence. Among them, the main polarization layer 121 can absorb the light vibration component parallel to its arrangement direction while allowing the light vibration component in the vertical direction to pass through, thereby achieving a polarization effect close to the theoretical value. Weather-resistant dichroic dyes are added to both the first compensation layer 122 and the second compensation layer 123. Although the polarization is relatively weaker, their weather resistance (e.g., the ability to withstand high temperature and high humidity) is improved. This "first compensation layer 122 - main polarization layer 121 - second compensation layer 123" sandwich structure can effectively protect the main polarization layer and further improve the reliability of the film layer.

[0080] In a feasible implementation manner, referring to Figure 6 , a triangular prism array structure 111 is provided on the light-emitting surface side of the brightness enhancement film 110.

[0081] Optionally, the brightness enhancement film includes a plate-shaped portion (not shown in the drawings) and a triangular prism array structure 111 provided on the light-facing side of the plate-shaped portion. After the scattered backlight can pass through the triangular prism array structure 111, it will be mainly concentrated within an angle of ±35° to achieve a light-concentrating effect.

[0082] Optionally, the material of the brightness enhancement film 110 includes at least one of PET, PC, PMMA, COP, PS, PE, PP, PI, PES, PSU, and PTFE.

[0083] Optionally, the material of the plate-shaped portion of the brightness enhancement film 110 includes at least one of PET, PC, PMMA, COP, PS, PE, PP, PI, PES, PSU, and PTFE.

[0084] Optionally, the thickness of the plate-shaped portion of the brightness enhancement film is 0.1 - 0.3 mm to balance reliability and low cost.

[0085] Exemplarily, when the size of the display device is 32 - 43 inches, the thickness of the plate-shaped portion of the brightness enhancement film is 0.1 mm; when the size of the display device is 49 - 65 inches, the thickness of the plate-shaped portion of the brightness enhancement film is 0.15 mm; when the size of the display device is above 70 inches, the thickness of the plate-shaped portion of the brightness enhancement film is 0.188 mm.

[0086] Optionally, the cross-section of the triangular prism array structure 111 can be an isosceles right triangle with a vertex angle of 90°±2°, and the spacing between the triangular prisms is 50 to 80 μm.

[0087] Optionally, a UV-type OAC optical glue can be coated on one side surface of the plate-shaped portion of the incremental film, and the triangular prism array structure 111 can be obtained through molding and UV curing.

[0088] Optionally, a single incremental film can achieve a brightness gain of about 15%.

[0089] Optionally, the number of increments in the polarization composite film 101 can be one or more.

[0090] In a feasible embodiment, the polarization composite film 101 further includes: an adhesive layer 130, disposed between the polarization film 120 and the triangular prism array structure 111, and diffusion particles are added to the adhesive layer 130. After the light energy exits from the triangular prism array structure 111, the arrangement is relatively regular, and subjective problems such as rainbow patterns and glare are likely to form. However, the doping of a small amount of diffusion particles can optimize this problem, and the polarization film 120 and the triangular prism array structure 111 (i.e., the brightness enhancement film 110) can also be bonded and compounded through the adhesive layer 130.

[0091] Optionally, in the case where the polarization film is obtained by unidirectional stretching, the polarization film 120 and the brightness enhancement film 110 are bonded and compounded through the adhesive layer 130.

[0092] Optionally, the thickness of the adhesive layer 130 is 8 to 15 μm. For example, the thickness of the adhesive layer 130 is 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, etc.

[0093] Optionally, 5 to 10 wt.% of diffusion particles are added to the adhesive layer 130. Optionally, the diffusion ions include TiO2.

[0094] Optionally, in order to ensure the bonding strength, the embedding depth of the vertex angle of the triangular prism array structure 111 into the adhesive layer 130 is 5 to 8 mm.

[0095] In this embodiment, a high degree of polarization is achieved through the main polarization layer 121, and a weather-resistant dichroic dye is added to the compensation polarization layer disposed on one side of the main polarization layer 121. Although the polarization property of the compensation polarization layer is relatively weaker, its ability to withstand high temperature and high humidity is improved. Therefore, it can replace the TAC layer to protect the main polarization layer 121; further, at least one brightness enhancement film 110 is disposed on the other side of the main polarization layer 121, which can not only achieve brightness gain but also replace the TAC layer to protect the main polarization layer 121, so that the polarization composite film 101 has the optical properties of first condensing light and then polarizing, effectively reducing the cost of the polarizing film. At the same time, because the polarization composite film 101 has the optical properties of first condensing light and then polarizing, it can replace both the optical film of the backlight module and the lower polarizing film of the liquid crystal panel (i.e., the polarizing film close to the light incident side of the liquid crystal panel) in the display device, thus effectively avoiding the occurrence of the situation where the lower polarizing film of the liquid crystal panel is scratched by the optical film of the backlight module.

[0096] In a second aspect of the embodiments of the present application, a backlight module is provided. The backlight module includes: a polarization composite film, and the polarization composite film includes a polarizing film and at least one brightness enhancement film stacked;

[0097] The polarizing film includes a main polarization layer and at least one compensation polarization layer;

[0098] The compensation polarization layer includes a first compensation layer, and the main polarization layer is disposed between the first compensation layer and the brightness enhancement film;

[0099] The compensation polarization layer is added with a weather-resistant dichroic dye.

[0100] Optionally, the weather-resistant dichroic dye includes at least one of azo dyes, polycyclic dyes, azo metal complex dyes, triphenylmethane dyes, and naphthoquinone dyes;

[0101] The material of the compensation polarization layer includes PVA.

[0102] Optionally, the compensation polarization layer further includes a second compensation layer, and the second compensation layer is disposed between the main polarization layer and the brightness enhancement film.

[0103] Optionally, the polarizing film is prepared by unidirectional stretching, and the direction of unidirectional stretching is perpendicular to the absorption axis of the polarizing film located on the light exit side of the liquid crystal panel.

[0104] Optionally, the stretching multiple of the unidirectional stretching is 3 to 5 times.

[0105] Optionally, the polarization composite film further includes an adhesive layer. A triangular prism array structure is disposed on the light exit surface side of the brightness enhancement film, and the adhesive layer is disposed between the polarizing film and the triangular prism array structure.

[0106] Optionally, the adhesive layer is added with diffusing particles.

[0107] In a third aspect of the embodiments of the present application, a display device is provided. The display device includes: a polarization composite film 101, and the polarization composite film 101 includes a polarization film and at least one brightness enhancement film arranged in a stacked manner;

[0108] The polarization film includes a main polarization layer and at least one compensation polarization layer;

[0109] The compensation polarization layer includes a first compensation layer, and the main polarization layer is arranged between the first compensation layer and the brightness enhancement film;

[0110] The compensation polarization layer is added with a weather-resistant dichroic dye.

[0111] Optionally, the weather-resistant dichroic dye includes at least one of: azo dyes, polycyclic dyes, azo metal complex dyes, triphenylmethane dyes, and naphthoquinone dyes;

[0112] And / or, iodine is added to the main polarization layer;

[0113] And / or, the material of the main polarization layer and / or the compensation polarization layer includes PVA.

[0114] Optionally, the compensation polarization layer further includes a second compensation layer, and the second compensation layer is arranged between the main polarization layer and the brightness enhancement film.

[0115] Optionally, the polarization film 120 is prepared by unidirectional stretching, and the direction of unidirectional stretching is perpendicular to the absorption axis of the polarizing film on the light-emitting side of the liquid crystal panel 20.

[0116] Optionally, the stretching multiple of the unidirectional stretching is 3 to 5 times.

[0117] Optionally, the polarization composite film further includes an adhesive layer, a triangular prism array structure is arranged on the light-emitting surface side of the brightness enhancement film, and the adhesive layer is arranged between the polarization film and the triangular prism array structure.

[0118] Optionally, the adhesive layer is added with diffusion particles.

[0119] In a feasible embodiment, referring to Figure 7 and 8 , the display device includes: a backlight module 10 and a liquid crystal panel 20. A polarization composite film 101 is arranged on the light-emitting side of the backlight module 10, and a diffusion plate 102 may further be arranged on the light-incident side of the polarization composite film 101;

[0120] The liquid crystal panel 20 includes a first glass substrate, a thin film transistor, a liquid crystal layer, a filter film 240, a second glass substrate 250, and a polarizing film (hereinafter referred to as the first polarizing film 260 for distinction) which are sequentially arranged in a stacked manner from the light-incident direction to the light-emitting direction.

[0121] Exemplarily, referring to Figure 9, a conventional display device includes a backlight module 10 and a liquid crystal panel 20. Among them, an optical film 103 is provided on the light-emitting side of the backlight module 10, and a diffusion plate 102 may also be provided on the light-incident side of the optical film 103; the conventional liquid crystal panel 20 adjacent to the optical film 103 may refer to Figure 10 , which includes a second polarizing film 270, a first glass substrate, thin-film transistors, a liquid crystal layer, a color filter film 240, a second glass substrate 250, and a first polarizing film 260 stacked in sequence from the light-incident direction to the light-emitting direction. Since the diffusion plate 102 and the optical film 103 of the backlight module 10 usually lack fixing measures, resulting in a large activity space, they are also extremely likely to come into flapping contact with the lower polarizing film of the liquid crystal panel 20 during transportation. The surface hardness of the optical film 103 is usually 1-2HB, while the hardness of the lower polarizing film (i.e., the second polarizing film 270) of the liquid crystal panel 20 is usually 8-10B. The hardness difference between the two is huge. Therefore, the second polarizing film 270 is extremely likely to be scratched by the optical film 103, resulting in quality accidents.

[0122] In the embodiment of the present application, a polarization composite film 101 is provided, which is disposed adjacent to the liquid crystal panel 20 on the light-emitting side of the backlight module 10. The polarization composite film 101 can simultaneously replace the optical film 103 of the backlight module 10 and the second polarizing film 270 of the liquid crystal panel 20 in the display device, so that the liquid crystal panel 20 can remove the second polarizing film 270. Further, in the display device, the polarization composite film 101 is connected to the first glass substrate of the liquid crystal panel 20, and the surface of the first glass substrate is relatively smooth. Even if they come into frequent contact during transportation, since the friction coefficient between the two is very small, there is almost no risk of scratching. Therefore, the structural reliability can be greatly improved. Further, in the conventional technology, in order to improve the scratching problem, an 8-10 mm gap needs to be reserved between the optical film 103 of the conventional backlight module 10 and the liquid crystal panel 20. By using the polarization composite film 101 provided in the embodiment of the present application, the gap between the polarization composite film 101 and the first glass substrate of the liquid crystal panel 20 can be reduced to about 3 mm, thereby reducing the overall thickness of the machine, achieving a more excellent appearance, and conforming to the development trend of the ultra-thinning of liquid crystal display products. Further, in the conventional technology, in order to improve the scratching problem, additional lower and front buffer pads made of 15-20 mm EPE (ethylene vinyl acetate foam) material need to be added to the overall packaging of the machine, which not only increases the additional cost, but also widens and thickens the volume of the carton; by using the polarization composite film 101 provided in the embodiment of the present application, no lower buffer pad or front buffer pad is required, and accordingly, the volume of the carton can be reduced and the container loading capacity can be greatly improved, which has obvious advantages.

[0123] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the patent protection scope of the present application.

Claims

1. A polarization composite film, characterized in that, The polarization composite film includes a polarization film and at least one brightness enhancement film which are stacked; The polarization film includes a main polarization layer and at least one compensation polarization layer; The compensation polarization layer includes a first compensation layer, and the main polarization layer is disposed between the first compensation layer and the brightness enhancement film; The compensation polarization layer is added with a weather-resistant dichroic dye.

2. The polarization composite film according to claim 1, wherein The weather-resistant dichroic dye includes at least one of azo dyes, polycyclic dyes, azo metal complex dyes, triphenylmethane dyes, and naphthoquinone dyes; The material of the compensation polarization layer includes PVA.

3. The polarization composite film according to claim 1, wherein The compensation polarization layer further includes a second compensation layer, and the second compensation layer is disposed between the main polarization layer and the brightness enhancement film.

4. The polarization composite film according to claim 1, wherein The polarization film is obtained by unidirectional stretching, and the direction of the unidirectional stretching is perpendicular to the absorption axis of the polarizing film on the light-emitting side of the liquid crystal panel.

5. The polarization composite film according to claim 4, wherein The stretching multiple of the unidirectional stretching is 3 to 5 times.

6. The polarization composite film according to any one of claims 1 to 5, characterized in that, The polarization composite film further includes an adhesive layer, a triangular prism array structure is provided on the light-emitting surface side of the brightness enhancement film, and the adhesive layer is disposed between the polarization film and the triangular prism array structure.

7. The polarization composite film according to claim 6, wherein The adhesive layer is added with diffusion particles.

8. A backlight module, characterized in that, The backlight module includes the polarization composite film according to any one of claims 1 to 7.

9. A display device, characterized in that, The display device includes the polarization composite film according to any one of claims 1 to 7.

10. The display device according to claim 9, wherein The display device includes: a backlight module and a liquid crystal panel; The polarization composite film is provided on the light-emitting side of the backlight module; The liquid crystal panel includes a first glass substrate, a thin film transistor, a liquid crystal layer, a filter film, a second glass substrate, and a polarizing film which are stacked in sequence from the light-incident direction to the light-emitting direction.

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