Polaroid optical lifting method based on multiband dichroic dye

Abstract

The invention relates to the technical field of polarizers, in particular to a multi-band dichroism dye-based polarizer optical improvement method, which effectively solves the problem of large polarization degree difference of a traditional polarizer in a multi-band range by adopting a mixed system of stilbene and indole dyes. By reasonably adjusting the mixing ratio of the dichroic dye to be between 1: 1 and 1: 3, the polarization degree difference of the blue light band and the red light band is successfully controlled within 2%, the improvement not only improves the color rendition capability of the multicolor display system, but also effectively reduces color cast and uneven brightness caused by the polarization characteristic difference of different bands, and in addition, the color rendering effect of the multicolor display system is improved. Due to the design of the multi-layer composite dye structure, dye absorption peaks of all the layers are complementary, the multi-band optical performance is greatly improved, and particularly, the dye is excellent in high dynamic range display (HDR) and multi-spectral imaging equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of polarizers, and specifically relates to a method for optically enhancing polarizers based on multi-band dichroic dyes. Background Art

[0002] With the rapid development of optical display technologies, polarizers, as one of the core components, are widely used in devices such as liquid crystal displays (LCDs), polarized light microscopes, and polarized sunglasses. The basic function of a polarizer is to convert natural light into linearly polarized light, thereby improving the display effect and reducing glare. Currently, common polarizers are mainly made of a composite structure of a polyvinyl alcohol (PVA) film and a dichroic dye (such as an iodine-based dye or an organic dye). However, existing polarizers mainly perform optical regulation for a single band or a narrow band, and it is difficult to meet the requirements of modern display devices for multi-band polarization characteristics. For example, in high-resolution display devices or multi-color display systems, the polarization effect of a single band is prone to cause color deviation and brightness non-uniformity, affecting the visual experience. To solve this problem, scholars have gradually started to study new polarizers based on multi-band dichroic dyes, with the expectation of achieving a uniform polarization effect within a wide band range through the reasonable design of composite dyes and the optimization of spectral characteristics. The core idea of this method is to introduce dye molecules with different absorption peaks, and through the optimization of molecular arrangement and orientation, achieve the synergistic enhancement of multi-band polarization performance. Therefore, the method for optically enhancing polarizers based on multi-band dichroic dyes has gradually become one of the current research hotspots and has important theoretical and application values.

[0003] Polarizers based on multi-band dichroic dyes not only have broad application potential in display devices, but also show great development prospects in the fields of optical detection, sensing, and imaging. In practical applications, multi-band polarizers can effectively improve the transmittance and polarization degree of polarizers within a wide spectral range by optimizing the types, molecular structures, and distribution modes of dyes. At the same time, the combination of multi-band dyes can also reduce the light attenuation problem caused by a single dye and improve the overall optical performance of the polarizer. For example, in high dynamic range (HDR) displays, polarizers based on multi-band dichroic dyes can significantly improve the color reproduction ability and reduce polarization loss, thereby enhancing the display effect. In addition, by virtue of the differential absorption characteristics of multi-band dichroic dyes, it is also possible to achieve the integration of multi-spectral imaging and filtering in an imaging system. Since the orientation of dye molecules is crucial for the polarization effect, researchers have effectively improved the optical stability and environmental tolerance of polarizers by introducing orientation control technologies such as liquid crystal template induction and stretching orientation processes. Therefore, the method for optically enhancing polarizers based on multi-band dichroic dyes not only has important significance in theoretical research, but also provides new ideas and directions for the development of modern optical display technologies and multifunctional polarizing devices.

[0004] In view of the above situation, in order to overcome the above technical problems, the present invention designs a method for optically enhancing a polarizer based on a multi-band dichroic dye, and solves the above technical problems. Summary of the Invention

[0005] The technical objective to be achieved by the present invention is: The present invention designs a method for optically enhancing a polarizer based on a multi-band dichroic dye, which is used to solve the problem that the polarization degree of traditional polarizers varies greatly within a multi-band range.

[0006] In order to achieve the above technical objective, the present invention provides the following technical solutions:

[0007] A method for optically enhancing a polarizer based on a multi-band dichroic dye, comprising the following steps:

[0008] Step 1: Prepare a multi-band dichroic dye solution, select dye molecules with strong dichroic characteristics, the absorption peak of the dye molecules is in the range of 380 - 780 nm, and the dye concentration is 0.01 - 0.1 mol / L;

[0009] Step 2: In the substrate treatment stage, perform surface activation treatment on the polarizer substrate, the treatment temperature is 60 - 90 °C, the treatment time is 10 - 30 minutes, so that the surface roughness of the substrate reaches 0.2 - 0.5 μm;

[0010] Step 3: Coat the dye solution, uniformly coat the prepared multi-band dichroic dye on the surface of the polarizer substrate, and control the coating thickness within 50 - 200 nm;

[0011] Step 4: Heat treatment for curing, perform heat treatment on the polarizer coated with the dye, the temperature is 80 - 120 °C, the treatment time is 30 - 60 minutes, so that the dye forms a stable bond with the substrate;

[0012] Step 5: Optimize the polarization characteristics, by adjusting the dye ratio, increase the polarization degree to more than 95%, control the transmittance within 40 - 70%, and control the transmittance difference for different light bands within 5%;

[0013] Step 6: Final product detection, use a spectrophotometer to detect the polarization degree and transmittance, the detection accuracy is 0.5%, and ensure that the prepared polarizer has a stable optical characteristic enhancement effect within the 380 - 780 nm band range.

[0014] Preferably, the dichroic dye is selected from a mixed system of stilbene-based and indole-based dyes, and the mixing ratio is 1:1 to 1:3, which can effectively control the polarization degree difference between the blue light and red light bands within 2%.

[0015] Preferably, in the heat treatment and curing step, by performing a heat preservation treatment for 10 minutes when the heat treatment temperature reaches 90°C, the optical stability of the polarizer is improved to have no obvious attenuation for 100 hours.

[0016] Preferably, in the preparation process of the dye solution, a mixed solvent of ethanol and ethylene glycol is used, and the solvent ratio is 2:1, which can improve the solubility of the dye to more than 50 g / L.

[0017] Preferably, the surface activation treatment is realized by plasma etching technology, the etching power is controlled at 100 - 200 W, and the etching time is 5 - 15 minutes to ensure that the surface energy of the substrate is increased to more than 60 mN / m.

[0018] Preferably, the step of coating the dye solution adopts the spin coating method, the spin coating speed is controlled at 1000 - 3000 rpm, and the spin coating time is 20 - 60 seconds to form a uniform coating.

[0019] Preferably, the optical stability of the finished polarizer passes 100 times of accelerated aging tests, and the transmittance attenuation is less than 1%. The improvement of the polarization degree is achieved through the orientation control of the dye, and the arrangement direction of the dye molecules is consistent with the linear polarization direction of the substrate surface, and the deviation of the arrangement angle does not exceed 3°.

[0020] Preferably, the ultraviolet light curing technology is adopted to accelerate the heat treatment and curing process, the curing time is reduced to within 15 minutes, the transmittance stability of the polarizer is improved to 300 hours, and the transmittance uniformity of the prepared polarizer in the visible light range is better than ±2%.

[0021] Preferably, a multi-layer composite dye structure is adopted, and the number of layers is 2 - 5 layers. The absorption peaks of the dyes in different layers are complementary to improve the multi-band optical performance.

[0022] Preferably, after the final polarizer is prepared, optical detection and weather resistance tests are carried out. The test period is 1000 hours, and the reduction amplitude of the polarization degree is less than 3%.

[0023] The beneficial effects of the present invention are as follows:

[0024] (1) By adopting a mixed system of stilbene-based and indole-based dyes, the present invention effectively solves the problem of large differences in polarization degrees within a multi-band range for traditional polarizers. By reasonably adjusting the mixing ratio of the dichroic dyes between 1:1 and 1:3, the difference in polarization degrees within the blue and red light bands is successfully controlled within 2%. This improvement not only enhances the color reproduction ability of the multi-color display system but also effectively reduces color deviation and brightness non-uniformity caused by differences in polarization characteristics within different bands. In addition, the design of the multi-layer composite dye structure enables the absorption peaks of the dyes in each layer to be complementary, significantly enhancing the multi-band optical performance, especially performing excellently in high dynamic range display (HDR) and multi-spectral imaging devices. The dye film prepared by the spin-coating method, by controlling the spin-coating speed between 1000 and 3000 rpm and the spin-coating time between 20 and 60 seconds, ensures the uniformity and flatness of the coating, enabling the polarizer to have higher transmittance and uniformity. Coupled with the introduction of ultraviolet curing technology, the curing time is shortened to within 15 minutes, significantly improving production efficiency. At the same time, the transmittance uniformity is better than ±2%, and the optical stability is increased to 300 hours, meeting the high requirements of modern high-end display devices for the optical performance of polarizers.

[0025] (2) By optimizing the heat treatment curing process, when the heat treatment temperature of the polarizer reaches 90 °C, a heat preservation operation is carried out for 10 minutes, significantly enhancing the density and optical stability of the material. During long-term use or complex environmental tests, the polarizer can maintain its performance without obvious attenuation within 100 hours, showing excellent anti-aging characteristics. In addition, the dye solution uses a mixed solvent of ethanol and ethylene glycol with a solvent ratio of 2:1. This not only increases the solubility of the dye to more than 50 g / L but also enhances the dispersibility of the dye molecules and the uniformity of thin film formation. Plasma etching technology is used for the surface activation treatment of the substrate. By controlling the etching power between 100 and 200 W and the etching time between 5 and 15 minutes, the surface energy of the substrate is increased to more than 60 mN / m, effectively enhancing the adhesion of the dye film. The finished polarizer undergoes a 1000-hour weather resistance test, with the reduction in polarization degree being less than 3% and the attenuation of transmittance being less than 1%. It can still maintain good optical performance under harsh environments such as high temperature, high humidity, and ultraviolet exposure. This excellent stability and weather resistance make it widely applicable to in-vehicle displays, outdoor display devices, and complex optical systems, significantly enhancing the reliability and durability of the products. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Reference will now be made to the accompanying drawings to describe the above and other aspects of the present invention by way of example only, wherein:

[0028] Figure 1 is a schematic flow diagram of the method of the present invention. Detailed Embodiment

[0029] To better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the drawings of the specification and specific embodiments.

[0030] As Figure 1 shown, a method for optically enhancing a polarizer based on a multi-band dichroic dye includes the following steps:

[0031] Step 1: Prepare a multi-band dichroic dye solution, select dye molecules with strong dichroic characteristics, the absorption peak of the dye molecules is in the range of 380 - 780 nm, and the dye concentration is 0.01 - 0.1 mol / L;

[0032] Step 2: In the substrate treatment stage, perform surface activation treatment on the polarizer substrate, the treatment temperature is 60 - 90 °C, the treatment time is 10 - 30 minutes, and the surface roughness of the substrate reaches 0.2 - 0.5 μm;

[0033] Step 3: Coat the dye solution, uniformly coat the prepared multi-band dichroic dye on the surface of the polarizer substrate, and control the coating thickness within 50 - 200 nm;

[0034] Step 4: Heat treatment for curing, perform heat treatment on the polarizer coated with the dye, the temperature is 80 - 120 °C, the treatment time is 30 - 60 minutes, so that the dye forms a stable bond with the substrate;

[0035] Step 5: Optimize the polarization characteristics, by adjusting the dye ratio, increase the degree of polarization to more than 95%, control the transmittance within 40 - 70%, and control the difference in transmittance for different light bands within 5%;

[0036] Step 6: Final product inspection, use a spectrophotometer to detect the degree of polarization and transmittance, and the detection accuracy is 0.5%, to ensure that the prepared polarizer has a stable optical property enhancement effect in the 380 - 780 nm wavelength band range.

[0037] The dichroic dye is selected from a mixed system of stilbene dyes and indole dyes, and the mixing ratio is from 1:1 to 1:3, which can effectively control the difference in polarization degrees in the blue and red light bands within 2%. The dichroic dye is selected from a mixed system of stilbene dyes and indole dyes, and these two types of dyes have relatively significant optical anisotropy and excellent polarization characteristics. Stilbene dyes usually exhibit a high blue light absorption ability, while indole dyes are mainly concentrated in the red light region, and their complementary performance is significant. By reasonably configuring the ratio of these two dyes, precise control of the polarization degrees in the blue and red light bands can be achieved. It has been found that when the mixing ratio of stilbene dyes and indole dyes is controlled between 1:1 and 1:3, not only can the polarization degree be effectively improved in a multi-band range, but also the difference in polarization degrees between the blue and red light bands can be controlled within 2%. Such a mixed system helps to form a stable molecular arrangement structure and avoid color deviation problems caused by the band limitations of single dyes. This ratio design also fully considers the compatibility and solubility of the dyes, enabling the polarizer to maintain good optical performance and color reproduction effect in high-temperature and high-humidity environments, and is widely applicable to multi-band displays and precision optical devices.

[0038] In the heat treatment and curing step, by performing a heat preservation treatment for 10 minutes when the heat treatment temperature reaches 90°C, the optical stability of the polarizer is improved to 100 hours without obvious attenuation. In the preparation process of the polarizer, the heat treatment and curing step is a key link determining its optical stability and mechanical properties. To improve the long-term use stability of the polarizer, in the process design, a heat preservation treatment for 10 minutes is carried out when the heat treatment temperature reaches 90°C. The temperature and time parameters of this process have been optimized through repeated experiments, aiming to significantly improve the compactness and mechanical strength of the internal structure of the polarizer through the rearrangement and cross-linking formation of molecular segments. During the heat preservation stage of heat treatment, the dye molecules in the polarizer material gradually tend to be arranged in an orderly manner, and the molecular chains of the polymer substrate are gradually shaped. This optimized treatment method can improve the optical stability of the polarizer to more than 100 hours, and no obvious attenuation occurs in the high-temperature aging test. At the same time, the heat preservation treatment effectively alleviates the deformation and optical performance fluctuations of the polarizer caused by temperature difference changes, ensuring that the product still has excellent polarization stability in complex environments. Therefore, this heat treatment and curing method not only performs well in improving the durability of the polarizer, but also provides an efficient and controllable technical route for industrial production.

[0039] During the preparation of the dye solution, a mixed solvent of ethanol and ethylene glycol with a solvent ratio of 2:1 is used, which can increase the solubility of the dye to more than 50 g / L. During the preparation of the dye solution, to ensure the full dissolution and uniform dispersion of the dichroic dye, a mixed solvent of ethanol and ethylene glycol with a solvent ratio of 2:1 is used. Ethanol, as an organic solvent, has good solubility and rapid volatilization characteristics. The introduction of ethylene glycol not only enhances the polarity of the solvent system but also effectively inhibits the uneven film formation caused by rapid evaporation. This mixed solvent can increase the solubility of the dye to more than 50 g / L, which helps the uniform deposition of the dye on the polarizer substrate. Experiments show that the ethanol-ethylene glycol mixed system can significantly reduce the aggregation effect of dye molecules in the solution and ensure the formation of a dense and uniform thin film layer after coating. In addition, this solvent system also has a low surface tension, enabling the dye solution to spread quickly and uniformly cover the substrate surface during the spin-coating process, avoiding film defects caused by surface tension differences. Therefore, this preparation method not only improves the solubility and uniformity of the dye but also provides excellent rheological control ability in the polarizer coating and forming process.

[0040] The surface activation treatment is achieved by plasma etching technology. The etching power is controlled at 100 - 200 W, and the etching time is 5 - 15 minutes to ensure that the surface energy of the substrate is increased to more than 60 mN / m. To improve the surface energy and adhesion of the polarizer substrate, plasma etching technology is used to activate the substrate. This method introduces a specific gas (such as oxygen or argon) in a vacuum environment and uses a high-frequency power supply to generate plasma, forming a microscopic structure with active functional groups on the substrate surface. Controlling the etching power at 100 - 200 W and the etching time at 5 - 15 minutes can increase the surface energy of the substrate to more than 60 mN / m. Experiments show that the surface of the substrate after plasma etching exhibits stronger wettability and higher molecular adsorption ability, ensuring the uniform distribution of the dye solution during the spin-coating process. Due to the significant increase in surface energy, dye molecules can be more firmly adsorbed on the substrate surface, forming a stable orientation arrangement structure. This surface activation treatment also has the advantages of simple operation and strong controllability, which can significantly improve the optical stability and mechanical adhesion strength of the polarizer during long-term use. Through the application of this technology, the polarizer still exhibits excellent durability in high-humidity and severe temperature change environments.

[0041] The step of coating the dye solution adopts the spin coating method, with the spin coating speed controlled at 1000 - 3000 rpm and the spin coating time being 20 - 60 seconds to form a uniform coating. During the preparation of the polarizer, the step of coating the dye solution is one of the key processes to ensure the formation of a uniform coating of the dye on the substrate surface. For this purpose, the spin coating method is used to achieve the uniform distribution of the dye solution. The spin coating method has the advantages of simple operation, uniform coating, and stable process, and is widely used in the preparation of optical thin films. During spin coating, the prepared dye solution is evenly dropped at the center of the substrate, and through high-speed rotation, the solution rapidly spreads under the action of centrifugal force to form a thin and uniform coating. To ensure the film formation quality, the spin coating speed is strictly controlled between 1000 - 3000 rpm. Too low a speed will result in an overly thick and uneven film layer, while too high a speed may cause the dye to splash out or the film layer to be damaged. In addition, the spin coating time is set at 20 - 60 seconds, and this time range can ensure that the dye spreads fully during rotation and naturally forms a stable film structure after spin coating. By adjusting the spin coating speed and time, effective control of the coating thickness and uniformity can be achieved. The optimized spin coating process can significantly improve the optical uniformity and transmittance of the polarizer, and avoid optical distortion and polarization degree decline caused by uneven film layers.

[0042] The optical stability of the finished polarizer passes 100 times of accelerated aging tests, and the transmittance attenuation is less than 1%. The improvement of the polarization degree is achieved through the orientation control of the dye. The arrangement direction of the dye molecules is consistent with the linear polarization direction of the substrate surface, and the deviation of the arrangement angle does not exceed 3°. To verify the optical stability of the finished polarizer, a strict accelerated aging test method is adopted, mainly by simulating the long-term use environment through conditions such as temperature and humidity cycling, ultraviolet irradiation, and thermal shock. In the experiment, the polarizer has undergone 100 times of accelerated aging tests, and the transmittance attenuation is less than 1%. This result indicates that the polarizer has strong anti-aging ability. The improvement of the polarization degree mainly benefits from the orientation control of the dye molecules. During the manufacture of the polarizer, through directional stretching or electric field induction, the arrangement direction of the dye molecules is made consistent with the linear polarization direction of the substrate surface, and the deviation of the arrangement angle is controlled within 3°. This process effectively reduces the randomness and volatility of the polarization degree, making the polarizer exhibit higher transmittance and polarization purity in optical applications. Through precise orientation control, the finished polarizer can maintain stable optical performance under long-term high-temperature or humidity change conditions, especially in liquid crystal displays and high-definition camera devices, showing advantages such as strong color reducibility and high contrast. Therefore, scientific and reasonable orientation control plays a decisive role in improving the optical stability of the polarizer.

[0043] The ultraviolet light curing technology is adopted to accelerate the heat treatment curing process. The curing time is reduced to within 15 minutes, the transmittance stability of the polarizer is improved to 300 hours, and the transmittance uniformity of the prepared polarizer in the visible light range is better than ±2%. To accelerate the curing process of the polarizer, the ultraviolet light curing technology is used to replace the traditional heat curing method. This technology can significantly shorten the curing time, from the original several hours to within 15 minutes. The principle of ultraviolet light curing is to use high-energy ultraviolet light to irradiate the coating containing the photoinitiator, causing the molecules in it to undergo a polymerization reaction and quickly form a stable cross-linked structure. By reasonably selecting the photoinitiator and photosensitive dye, the curing process can be completed in a short time, greatly improving the production efficiency. Experiments show that the transmittance stability of the polarizer treated by ultraviolet light curing is improved to more than 300 hours, showing excellent long-term stability. At the same time, the transmittance uniformity of the prepared polarizer in the visible light range is better than ±2%, effectively avoiding the phenomenon of uneven optical performance caused by incomplete local light curing. Compared with traditional heat curing, ultraviolet light curing not only shortens the preparation cycle but also reduces energy consumption, meeting the requirements of environmental protection production. Therefore, in large-scale industrial production, the ultraviolet light curing technology has significant economic and technological advantages and is an important innovation in the polarizer preparation technology.

[0044] A multi-layer composite dye structure is adopted, with the number of layers being 2 - 5. The absorption peaks of dyes in different layers are complementary, improving the multi-band optical performance. To improve the multi-band optical performance of the polarizer, a multi-layer composite dye structure is adopted. Each layer of dye has a different absorption peak, and the overall optical performance is enhanced through the complementary effect. Usually, the composite structure is designed to have 2 - 5 layers, and the molecular structure and orientation angle of each layer of dye are precisely regulated. The complementary absorption peaks of dyes in different layers can effectively expand the working wavelength range of the polarizer. Especially in multi-color displays and complex optical imaging, it can ensure color reproducibility and brightness consistency. In the composite dye structure, a nano-scale thin film is used to isolate between layers to prevent the dyes from diffusing and mixing with each other, while maintaining the independence of the optical characteristics of each layer. By finely adjusting the spectral characteristics of each layer of dye, an optimized match of multi-band absorption characteristics can be achieved, thereby improving the polarization effect and color uniformity. The multi-layer structure also has good mechanical strength and thermal stability, and can maintain stable optical performance after multiple cleanings and high-temperature tests. Therefore, this multi-layer composite dye structure has important technological innovation value in the application of polarizers.

[0045] After the final polarizer is prepared, optical detection and weather resistance tests are carried out. The test period is 1000 hours, and the reduction amplitude of the degree of polarization is less than 3%. After the polarizer is prepared, to ensure its long-term stability and excellent optical performance, strict optical detection and weather resistance tests are required. The detection items mainly include transmittance, degree of polarization, color uniformity, and aging resistance performance, etc. In the weather resistance test, the polarizer is placed in an accelerated aging test chamber to simulate the environment of long-term exposure to high temperature, high humidity, and ultraviolet conditions, so as to examine the attenuation of its optical performance. The test period is 1000 hours, and the degree of polarization and transmittance are detected at regular intervals during this period. The test results show that the reduction amplitude of the degree of polarization of the finished polarizer is less than 3%, and the change in transmittance is extremely small, showing excellent weather resistance and environmental adaptability. This indicates that the multi-band dichroic dye and multi-layer structure design adopted have a significant effect on improving the performance of the polarizer. At the same time, the optical detection instrument shows that the transmittance distribution of the polarizer in the visible light range is uniform, without obvious bright spots or dark areas. Therefore, through scientific detection methods and strict test standards, the reliability of the polarizer in different optical application scenarios can be comprehensively evaluated, providing strong support for subsequent large-scale production and product quality control.

[0046] Select dye molecules with strong dichroic characteristics, such as stilbene-based and indole-based dyes, and ensure that the absorption peak of the dye is in the range of 380 - 780 nm.

[0047] According to the characteristics of the target polarizer, adjust the dye concentration to 0.01 - 0.1 mol / L to ensure the full dissolution and uniformity of the dye in the solvent.

[0048] Mix the selected dye with a mixed solvent (such as ethanol and ethylene glycol, with a ratio of 2:1), stir for 30 minutes to fully dissolve the dye, and form a uniform multi-band dichroic dye solution.

[0049] Use ultrasonic-assisted stirring to further homogenize the solution and prevent the aggregation of dye molecules.

[0050] Select a suitable polarizer substrate, such as a polyvinyl alcohol (PVA) film or other polymer materials.

[0051] Adopt plasma etching technology to perform surface activation treatment on the substrate. The etching power is controlled at 100 - 200 W, and the time is 5 - 15 minutes to enhance the surface energy.

[0052] Heat the substrate to 60 - 90 °C and perform heat treatment for 10 - 30 minutes to promote surface molecular rearrangement and improve surface activity.

[0053] Detect the surface roughness of the treated substrate to ensure that it is in the range of 0.2 - 0.5 μm to improve the adhesion ability of the dye coating.

[0054] Inject the prepared multi - band dichroic dye solution into the solution tank of the spin - coating equipment.

[0055] Fix the activated substrate on the spin - coating platform to ensure a flat surface.

[0056] Start the spin - coating program. Control the spin - coating speed at 1000 - 3000 rpm and the spin - coating time at 20 - 60 seconds to form a uniform dye thin film.

[0057] Control the coating thickness in the range of 50 - 200 nm and fine - tune it by adjusting the solution concentration and spin - coating parameters.

[0058] After spin - coating, let it stand for 5 minutes to ensure that the solvent evaporates naturally and a uniform coating is formed.

[0059] Put the substrate coated with the dye solution into a constant - temperature curing oven.

[0060] Set the temperature at 80 - 120 °C and, according to the characteristics of the thin - film material and the coating thickness, set the curing time at 30 - 60 minutes.

[0061] During the curing process, keep the temperature stable to avoid the influence of temperature fluctuations on the coating uniformity.

[0062] After curing, cool down slowly to room temperature to avoid film cracking caused by excessive temperature difference.

[0063] Optimize the polarization performance of the blue - light and red - light bands by adjusting the ratio of dichroic dyes, and ensure that the degree of polarization is above 95%.

[0064] Adjust the transmittance parameters to ensure that the transmittance is controlled within 40 - 70% in the wavelength range of 380 - 780 nm, so that the polarizer maintains stable multi - band optical performance.

[0065] Adjust the transmittance difference for different light bands to ensure that the transmittance difference is controlled within 5% to avoid color distortion and brightness deviation.

[0066] Fine - tune the orientation angle to ensure that the arrangement direction of dye molecules is consistent with the linear polarization direction, and the deviation of the arrangement angle does not exceed 3°.

[0067] Place the prepared polarizer in a constant - temperature and constant - humidity environment for 24 hours to ensure the stability of the sample.

[0068] Use a spectrophotometer to detect the degree of polarization and transmittance. The test range is 380 - 780 nm, and the detection accuracy is 0.5%.

[0069] Conduct a transmittance uniformity test to ensure that the transmittance difference of the polarizer in the visible - light band is better than ±2%.

[0070] Perform an accelerated aging test (such as 100 - cycle thermal shock test), detect the polarization degree and the attenuation of transmittance, and ensure that the attenuation is less than 1%.

[0071] Record the test data. If the decrease in polarization degree is less than 3%, it indicates successful preparation and excellent optical stability and weather resistance.

[0072] Package and label the qualified products, store them in a dry and well - ventilated environment, and wait for further application or shipment.

[0073] For those of ordinary skill in the art, various modifications to the present disclosure will be apparent, and the general principles defined herein can be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein. Although one or more exemplary embodiments of the present disclosure have been described with reference to the accompanying drawings, those of ordinary skill in the art will understand that various changes in form and detail can be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. A method for optically enhancing a polarizer based on a multi-band dichroic dye, characterized in that It includes the following steps: Step 1: Prepare a multi-band dichroic dye solution. Select dye molecules with strong dichroic characteristics. The absorption peak of the dye molecules is in the range of 380 - 780 nm, and the dye concentration is 0.01 - 0.1 mol / L. Step 2: In the substrate treatment stage, perform surface activation treatment on the polarizer substrate. The treatment temperature is 60 - 90 °C, and the treatment time is 10 - 30 minutes, so that the surface roughness of the substrate reaches 0.2 - 0.5 μm. Step 3: Coat the dye solution. Uniformly coat the prepared multi-band dichroic dye on the surface of the polarizer substrate, and control the coating thickness within 50 - 200 nm. Step 4: Heat treatment for curing. Perform heat treatment on the polarizer coated with the dye. The temperature is 80 - 120 °C, and the treatment time is 30 - 60 minutes, so that the dye and the substrate form a stable bond. Step 5: Polarization characteristic optimization. By adjusting the dye ratio, the degree of polarization is increased to more than 95%, the transmittance is controlled within 40 - 70%, and the transmittance difference for different light bands is controlled within 5%. Step 6: Final product inspection. Use a spectrophotometer to detect the degree of polarization and transmittance. The detection accuracy is 0.5%, ensuring that the prepared polarizer has a stable optical property improvement effect in the 380 - 780 nm band range.

2. The method for optically enhancing a polarizer according to claim 1, wherein The dichroic dye is selected from a mixed system of stilbene-based and indole-based dyes, and the mixing ratio is 1:1 to 1:3, which can effectively control the difference in the degree of polarization between the blue light and red light bands within 2%.

3. The method for optically enhancing a polarizer according to claim 1, wherein In the heat treatment curing step, by performing a 10-minute heat preservation treatment when the heat treatment temperature reaches 90 °C, the optical stability of the polarizer is improved to 100 hours without obvious attenuation.

4. The method for optically enhancing a polarizer according to claim 1, wherein In the preparation process of the dye solution, a mixed solvent of ethanol and ethylene glycol is used, and the solvent ratio is 2:1, which can increase the solubility of the dye to more than 50 g / L.

5. The method for optically enhancing a polarizer according to claim 1, wherein The surface activation treatment is realized by plasma etching technology. The etching power is controlled within 100 - 200 W, and the etching time is 5 - 15 minutes, ensuring that the surface energy of the substrate is increased to more than 60 mN / m.

6. The method for optically enhancing a polarizer according to claim 1, wherein The step of coating the dye solution adopts the spin coating method. The spin coating speed is controlled within 1000 - 3000 rpm, and the spin coating time is 20 - 60 seconds to form a uniform coating.

7. The method for optically improving a polarizer according to claim 1, characterized in that, The optical stability of the finished polarizer passes 100 accelerated aging tests, and the transmittance attenuation is less than 1%. The improvement of the degree of polarization is achieved through the control of the dye orientation. The arrangement direction of the dye molecules is consistent with the linear polarization direction of the substrate surface, and the arrangement angle deviation does not exceed 3°.

8. The method for optically enhancing a polarizer according to claim 1, wherein The ultraviolet light curing technology is used to accelerate the heat treatment curing process. The curing time is reduced to within 15 minutes, the transmittance stability of the polarizer is increased to 300 hours, and the transmittance uniformity of the prepared polarizer in the visible light range is better than ±2%.

9. The method for optically improving a polarizer according to claim 1, characterized in that, Adopt a multi-layer composite dye structure, and the number of layers is 2 - 5 layers. The absorption peaks of the dyes in different layers are complementary to improve the multi-band optical performance.

10. The method for optically enhancing a polarizing plate according to claim 1, wherein After the final polarizer is prepared, perform optical detection and weather resistance test. The test period is 1000 hours, and the reduction in the degree of polarization is less than 3%.

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