A method for stabilizing color display of liquid crystal display screen

Abstract

The present invention discloses a method for color stabilization of a liquid crystal display screen, comprising providing a liquid crystal display screen having a liquid crystal layer, wherein the liquid crystal display screen comprises an upper polarizer, an upper glass, an upper electrode, a sealing frame, a lower electrode, a lower glass and a lower polarizer, wherein the sealing frame has a liquid crystal layer in the middle; a multilayer structure of high refractive index material, medium refractive index material and low refractive index material arranged in the order of high refractive index-medium refractive index-low refractive index is arranged between the upper polarizer and the lower polarizer of the liquid crystal display screen to form a gradient optical structure; the spiral arrangement and thickness gradient of the liquid crystal molecules are controlled; and the angle of the polarizer is adjusted according to temperature changes. By increasing the box thickness of the liquid crystal layer and optimizing the multilayer optical structure, the present invention effectively reduces the influence of high temperature on the display effect and significantly improves the color stability of the liquid crystal display screen.

Description

Technical Field

[0001] The invention relates to the technical field of color display of liquid crystal display screens, and in particular to a method for stabilizing the color display of liquid crystal display screens. Background Art

[0002] With the development of electronic information technology, LCD has become one of the most competitive electronic display products for human-machine interface. In recent years, LCD has been rapidly promoted and applied in the fields of home appliances, audio, industrial control, etc., which has put forward higher and higher requirements for LCD's high contrast and background color. Among them, STN negative display is sought after by customers because of its blue background color, white font color and good contrast.

[0003] 1. However, the background color of traditional STN negative display products is extremely sensitive to high temperature. The temperature rise will cause the background color to turn red, especially at a high temperature of 50°C, it begins to change significantly. At a high temperature of 80°C, the background color has turned red and the font color becomes lighter, thus affecting the contrast and display effect of the LCD;

[0004] 2. In addition, in a traditional LCD screen under high temperature environment, the arrangement of liquid crystal molecules will change significantly, resulting in unstable birefringence, thus affecting the display effect. The thermal expansion effect of liquid crystal molecules is particularly obvious under high temperature, which will cause uneven changes in the thickness of the liquid crystal layer, and then cause obvious changes in the display background color, resulting in unstable color rendering of the display screen.

[0005] Based on this, a method for stabilizing the color display of a liquid crystal display screen is needed. Summary of the invention

[0006] To achieve the above object, the present invention provides the following solution: A method for stabilizing the color display of a liquid crystal display screen, comprising:

[0007] A liquid crystal display screen with a liquid crystal layer is provided, wherein the liquid crystal display screen comprises an upper polarizer, an upper glass, an upper electrode, a sealing frame, a lower electrode, a lower glass and a lower polarizer, wherein the middle of the sealing frame has a liquid crystal layer, the upper polarizer and the lower polarizer are both dye-based wide-temperature blue polarizers, the initial polarization angle of the upper polarizer is 110°, and the initial polarization angle of the lower polarizer is 105°;

[0008] A high refractive index material with a refractive index of 1.8, a medium refractive index material with a refractive index of 1.6 and a low refractive index material with a refractive index of 1.4 are arranged between the upper polarizer and the lower polarizer of the liquid crystal display screen. A multilayer structure is arranged in the order of high refractive index-medium refractive index-low refractive index to form a gradient optical structure. When the temperature changes, the gradient optical structure adjusts the transmittance and polarization of the liquid crystal layer through the multiple reflection and refraction effects of light. When the ambient temperature rises from 25°C to 80°C, the refractive index of the light passing through the material layer changes, so that the transmittance of the liquid crystal layer gradually decreases, while the polarization effect is optimized. The relationship between the transmittance T and the temperature change ΔT is described by the formula T=T0·exp(-k·ΔT), where T0 is the initial transmittance and k is the temperature sensitivity coefficient; inside the liquid crystal layer, the liquid crystal molecules are arranged in a spiral shape in the liquid crystal layer by controlling the arrangement mode of the liquid crystal molecules, and the liquid crystal layer maintains a stable birefringence Δ at high temperature through the interaction force between the molecules. n =n e -n o , where n e is the refractive index of unconventional light, n o The refractive index of conventional light is reduced through this arrangement, and the thickness gradient of the liquid crystal layer is controlled so that the thickness of the liquid crystal layer gradually changes from 8 microns in the center to 5 microns at the edge to balance the thermal expansion effect of the liquid crystal layer at high temperature. The thickness change is described by Δd=d(T)-d0, where d(T) is the thickness of the liquid crystal layer at high temperature, d0 is the thickness of the liquid crystal layer at room temperature, and the thickness change rate of the liquid crystal layer Δd / d0 is effectively controlled; the angles of the upper and lower polarizers of the liquid crystal display are adjusted according to the temperature change. When the temperature rises from 25°C to 80°C, the angle of the upper polarizer is adjusted from the initial 110° to 107°, and the angle of the lower polarizer is adjusted from the initial 105° to 112° to optimize the polarization effect. The polarized light intensity I=I0Cos 2 (θ), where I0 is 1000cd / m 2 The change of the polarizer angle θ causes the light intensity I to change from 242cd / m 2 Change to 207cd / m 2 The angle polarization of the upper and lower polarizers makes the background color of the liquid crystal display light blue, and the background color changes little at high temperatures. The delay amount Δn×d of the liquid crystal layer is determined to be 0.89, where d is the box thickness of the liquid crystal layer, that is, the height of the middle of the sealing frame. The birefringence Δn of the liquid crystal decreases with increasing temperature, and the smaller Δn is, the darker the background color of the liquid crystal display will be. When the delay amount Δn×d of the liquid crystal layer is 0.89, it changes smoothly at high temperatures, and the background color of the liquid crystal screen changes smoothly.

[0009] Furthermore, the multilayer structure is formed by layer-by-layer deposition by evaporation, and a high refractive index material layer is deposited on the surface of the upper polarizer of the liquid crystal display screen, the refractive index of the high refractive index material is 1.8, the deposition rate during the evaporation process is controlled at 0.1 to 0.2 nanometers per second, and the evaporation temperature is controlled at 150 to 200 degrees Celsius. Next, a medium refractive index material layer and a low refractive index material layer are sequentially deposited on the high refractive index material layer, the refractive index of the medium refractive index material is 1.6, and the refractive index of the low refractive index material is 1.4. The deposition rate of the medium refractive index material layer is controlled at 0.08 to 0.15 nanometers per second, and the evaporation temperature is controlled at 140 to 190 degrees Celsius; the deposition rate of the low refractive index material layer is controlled at 0.05 to 0.1 nanometers per second, and the evaporation temperature is controlled at 130 to 180 degrees Celsius. The thickness of each layer of material is uniformly controlled at 50 to 100 nanometers, forming a multilayer optical structure with precise thickness and refractive index gradient.

[0010] Furthermore, by setting a thin interface lubricating layer between each layer of material in the multilayer structure, after depositing the high refractive index material layer, a high molecular polymer material is evaporated to form a lubricating layer with a thickness of 5 to 10 nanometers, and the high molecular polymer material is any one of polyvinyl alcohol or polydimethylsiloxane. The deposition temperature is controlled in the range of 60 to 80 degrees Celsius. After the lubricating layer is formed, the deposition of medium and low refractive index material layers is continued to form a thin interface lubricating layer to reduce the scattering effect at the interface.

[0011] Furthermore, an electric field is applied to make the liquid crystal molecules arrange in a spiral shape in the liquid crystal layer. The intensity of the electric field is 1 to 5 V / μm. The direction of the electric field is parallel to the initial arrangement direction of the liquid crystal molecules, so as to induce the liquid crystal molecules to arrange along a spiral path. Specifically, electrodes are arranged on both sides of the liquid crystal layer. The electrode material is a transparent conductive oxide. By controlling the voltage between the electrodes, an electric field is applied to make the liquid crystal molecules arrange along the direction of the electric field. In the initial stage, the intensity of the applied electric field is set to 1 V / μm, and the liquid crystal molecules begin to arrange along the direction of the electric field. Then, the electric field intensity is gradually increased until it reaches 5 V. / μm, so that the liquid crystal molecules are arranged along a spiral path, the direction of the electric field remains parallel to the initial arrangement direction of the liquid crystal molecules, so that the liquid crystal molecules can form a stable spiral structure when subjected to the electric field, the relationship between the electric field strength E=V / d and the voltage V and the electrode spacing d, where d is the electrode spacing, the unit is micron, during the electric field application process, the voltage increment is gradually adjusted and controlled within the range of 0.1 to 0.5V, and the temperature of the liquid crystal layer is kept stable at 25 to 30 degrees Celsius, so that the liquid crystal molecules can complete the spiral arrangement in a suitable temperature environment, forming a spirally arranged liquid crystal molecular structure.

[0012] Furthermore, during the electric field application process, the arrangement state of the liquid crystal molecules is monitored in real time, and the intensity of the applied electric field is adjusted using a high-precision voltage controller. The variation range of the electric field intensity is controlled within 0.1V / μm. At the same time, the time of applying the electric field is controlled between 10 and 30 seconds so that the arrangement of the liquid crystal molecules reaches a stable state. The laser interferometry method is used to monitor the spiral pitch of the liquid crystal molecules, and the electric field parameters are adjusted according to the real-time monitoring data so that the variation range of the spiral pitch of the liquid crystal molecules at high temperature is controlled within 0.01.

[0013] Furthermore, a higher concentration of liquid crystal monomers is added to the central area of ​​the liquid crystal layer, and a lower concentration of liquid crystal monomers is added to the edge area, so that the liquid crystal layer forms a structure with a gradually changing thickness from the center to the edge during the curing process. The concentration of the liquid crystal monomers is controlled at 10% to 20% in the central area and 5% to 10% in the edge area.

[0014] Furthermore, 0.5% of photosensitive material and 1% of thermosensitive liquid crystal material are doped in the central area of ​​the liquid crystal layer, and 0.2% of photosensitive material and 0.5% of thermosensitive liquid crystal material are doped in the edge area. Under ultraviolet light irradiation, the expansion effect of the photosensitive material causes the thickness of the liquid crystal layer to gradually change from 8 microns in the center to 5 microns at the edge. The relationship between the thickness change Δd, the light intensity I and the irradiation time t is described by Δd=α.It, where α is the expansion coefficient of the photosensitive material. At the same time, when the ambient temperature rises from 25°C to 80°C, the expansion effect of the thermosensitive liquid crystal material also causes the thickness of the liquid crystal layer to gradually change from 8 microns in the center to 5 microns at the edge. The relationship between the thickness change Δd and the temperature change ΔT is described by Δd=β·ΔT, where β is the expansion coefficient of the thermosensitive liquid crystal material.

[0015] Furthermore, an automatic voltage regulation module is added to the driving circuit of the liquid crystal display screen. The automatic voltage regulation module adjusts the driving voltage in real time according to the feedback signal of the temperature sensor. When the ambient temperature rises, the automatic voltage regulation module compensates for the thickness change of the liquid crystal layer by increasing the driving voltage. The relationship between the driving voltage V(t) and the temperature change ΔT is described by V(t)=V0+k·ΔT, where V0 is the initial driving voltage and k is the voltage compensation coefficient. By adjusting the driving voltage in real time, the thickness and birefringence of the liquid crystal layer at different temperatures are kept stable.

[0016] Furthermore, by setting a plurality of micrometer-level adjustment grooves in the liquid crystal layer, the depth of the adjustment grooves is in the range of 1 to 2 micrometers, and by adjusting the depth and position of the adjustment grooves, the thickness change rate of the liquid crystal layer from the center to the edge is controlled within 0.1, Describe the relationship between the thickness change rate Δd / d and the thickness d(T) at high temperature and the thickness d0 at room temperature.

[0017] Furthermore, two layers of electrodes are arranged on the upper and lower surfaces of the liquid crystal layer, namely, an inner electrode and an outer electrode. The inner electrode is in direct contact with the liquid crystal layer, and the outer electrode is arranged outside the inner electrode. By controlling the voltages of the inner electrode and the outer electrode respectively, the birefringence and thickness of the liquid crystal layer are adjusted. By Δn×d=(n e -n o )×d describes the delay Δn×d and the refractive index n of the unconventional light e 、Normal light refractive index n o The relationship between the thickness of the liquid crystal layer d and the retardation amount at which the liquid crystal layer is kept stable at high temperatures.

[0018] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0019] 1. The present invention can effectively reduce the influence of the thickness change of the liquid crystal layer on the display effect under high temperature environment by increasing the cell thickness of the liquid crystal layer, so that the thickness change rate of the liquid crystal layer under high temperature conditions is significantly reduced. Since the change of the background color is proportional to the thickness change rate, when the cell thickness of the liquid crystal layer increases, its change rate with temperature change decreases, and the background color change also decreases accordingly, thereby ensuring the display stability of the liquid crystal layer at different temperatures, effectively solving the problem of the background color turning red and the font color becoming lighter in traditional STN negative display products under high temperature, and improving the contrast and display effect of the liquid crystal display.

[0020] Second, the present invention forms a gradient optical structure between the upper polarizer and the lower polarizer of the liquid crystal display screen by setting a multilayer structure composed of high, medium and low refractive index materials. In a high temperature environment, the transmittance and polarization effect of the liquid crystal layer are automatically adjusted through the multiple reflection and refraction effects of light, so that the color rendering effect at high temperature remains stable, so that the transmittance of the liquid crystal layer gradually decreases with the temperature change, and the polarization effect is optimized, thereby reducing the change of the background color of the liquid crystal display screen in a high temperature environment, and significantly improving the stability of the display effect;

[0021] 3. The present invention applies an electric field to arrange liquid crystal molecules in a spiral shape in the liquid crystal layer, and uses a high-precision voltage controller to adjust the electric field strength in real time, thereby ensuring that the variation range of the spiral pitch of the liquid crystal molecules at high temperatures is controlled, so that the liquid crystal layer can still maintain good birefringence and color stability at high temperatures, avoiding display distortion caused by thermal expansion of liquid crystal molecules, and effectively solving the problem of unstable color rendering effect of traditional liquid crystal display screens in high temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 The present invention is a flow chart of the steps of the method for stabilizing the color development of a liquid crystal display screen. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Example

[0027] like Figure 1 As shown, a method for stabilizing the color display of a liquid crystal display screen in this embodiment includes:

[0028] A liquid crystal display screen with a liquid crystal layer is provided, wherein the liquid crystal display screen comprises an upper polarizer, an upper glass, an upper electrode, a sealing frame, a lower electrode, a lower glass and a lower polarizer, wherein the middle of the sealing frame has a liquid crystal layer, the upper polarizer and the lower polarizer are both dye-based wide-temperature blue polarizers, the initial polarization angle of the upper polarizer is 110°, and the initial polarization angle of the lower polarizer is 105°;

[0029] A multilayer structure is arranged between the upper polarizer and the lower polarizer of the liquid crystal display screen, which is composed of a high refractive index material with a refractive index of 1.8, a medium refractive index material with a refractive index of 1.6 and a low refractive index material with a refractive index of 1.4, in the order of high refractive index-medium refractive index-low refractive index, to form a gradient optical structure. The multilayer structure is formed by layer-by-layer deposition by evaporation. A high refractive index material layer is deposited on the surface of the upper polarizer of the liquid crystal display screen. The refractive index of the high refractive index material is 1.8. The deposition rate during the evaporation process is controlled at 0.1 to 0.2 nanometers per second, and the evaporation temperature is controlled at a range of 150 to 200 degrees Celsius. Next, Subsequently, a medium refractive index material layer and a low refractive index material layer are sequentially deposited on the high refractive index material layer, the refractive index of the medium refractive index material is 1.6, the refractive index of the low refractive index material is 1.4, the deposition rate of the medium refractive index material layer is controlled within a range of 0.08 to 0.15 nanometers per second, and the evaporation temperature is controlled within a range of 140 to 190 degrees Celsius; the deposition rate of the low refractive index material layer is controlled within a range of 0.05 to 0.1 nanometers per second, and the evaporation temperature is controlled within a range of 130 to 180 degrees Celsius, and the thickness of each layer of material is uniformly controlled within a range of 50 to 100 nanometers, so as to form a multilayer optical structure with precise thickness and refractive index gradient;

[0030] Deposition parameters of high, medium and low refractive index material layers Table 1:

[0031] Material Type Refractive Index Deposition rate (nm / s) Evaporation temperature (℃) Thickness of each layer (nm) High refractive index 1.8 0.1-0.2 150-200 50-100 Medium refractive index 1.6 0.08-0.15 140-190 50-100 Low refractive index 1.4 0.05-0.1 130-180 50-100

[0032] When the temperature changes, the gradient optical structure adjusts the transmittance and polarization of the liquid crystal layer through the multiple reflection and refraction effects of light. When the ambient temperature rises from 25°C to 80°C, the refractive index of the light passing through the material layer changes, causing the transmittance of the liquid crystal layer to gradually decrease, while the polarization effect is optimized. The relationship between the transmittance T and the temperature change ΔT is described by the formula T=T0·exp(-k·ΔT), where T0 is the initial transmittance and k is the temperature sensitivity coefficient;

[0033] By setting a multi-layer structure between the upper polarizer and the lower polarizer of the liquid crystal display, the problem of unstable optical performance caused by temperature changes can be effectively alleviated. The sequential arrangement of high refractive index, medium refractive index and low refractive index materials in the multi-layer structure enables the refraction and reflection of light between different material layers to be accurately controlled. Through the multiple reflection and refraction effects of light, the transmittance and polarization effect of the liquid crystal layer are adjusted when the temperature changes, ensuring that the liquid crystal display can maintain good color stability at different temperatures. Specifically, when the ambient temperature rises from 25°C to 80°C, the refractive index changes of the high refractive index material layer, the medium refractive index material layer and the low refractive index material layer make the light The propagation path of the line in these layers changes, which in turn affects the transmittance of the liquid crystal layer. By precisely controlling the thickness and refractive index gradient of each layer of material, the multi-layer structure can automatically adjust the transmittance of the liquid crystal layer when the temperature changes, so that it gradually decreases, avoiding the problem of excessive light intensity caused by temperature increase. In addition, the multi-layer structure is formed layer by layer by evaporation deposition, and the thickness of each layer of material is uniformly controlled within the range of 50 to 100 nanometers, so that the multi-layer structure has a high degree of consistency and stability. By precisely controlling the deposition rate and temperature range of different material layers during the evaporation process, the thickness and refractive index gradient of the material layer are formed, ensuring the high performance and long-term stability of the optical structure.

[0034] Table 2: Effect of thickness and refractive index gradient of multilayer structure materials on transmittance

[0035]

[0036] Table 2 shows the influence of the material thickness and refractive index gradient of the multilayer structure on the transmittance of the liquid crystal layer under different temperature conditions. By controlling the thickness and refractive index of each layer of material, it is ensured that the transmittance of the liquid crystal layer gradually decreases when the temperature changes, avoiding the problem of excessive light intensity, thereby ensuring the color stability and optical performance of the liquid crystal display at high temperatures.

[0037] Inside the liquid crystal layer, the arrangement of liquid crystal molecules is controlled so that the liquid crystal molecules are arranged in a spiral shape. Through the interaction between molecules, the liquid crystal layer maintains a stable birefringence Δ at high temperatures. n =n e -n o , where n e is the refractive index of unconventional light, n ois the refractive index of conventional light. Through this arrangement, the change of the birefringence of the liquid crystal layer at high temperature is reduced. Specifically, electrodes are set on both sides of the liquid crystal layer. The electrode material is a transparent conductive oxide. By controlling the voltage between the electrodes and applying an electric field, the liquid crystal molecules are arranged along the direction of the electric field. In the initial stage, the intensity of the applied electric field is set to 1V / μm, and the liquid crystal molecules begin to arrange along the direction of the electric field. Then, the electric field intensity is gradually increased until it reaches 5V / μm, so that the liquid crystal molecules are arranged along a spiral path. The direction of the electric field remains parallel to the initial arrangement direction of the liquid crystal molecules, so that the liquid crystal molecules can form a stable spiral structure when subjected to the electric field. The relationship between the electric field intensity E=V / d and the voltage V and the electrode spacing d, where d is the electrode spacing, the unit is micrometer. During the electric field application process, the voltage increment is gradually adjusted to control it within the range of 0.1 to 0.5V, and the temperature of the liquid crystal layer is kept stable at 25 to 30 degrees Celsius, so that the liquid crystal molecules The liquid crystal molecules are spirally arranged in a suitable temperature environment to form a spirally arranged liquid crystal molecular structure. By controlling the arrangement of the liquid crystal molecules, the birefringence variation range of the spiral pitch of the liquid crystal molecules at high temperature is controlled within 0.01. The thickness gradient of the liquid crystal layer is controlled so that the thickness of the liquid crystal layer gradually changes from 8 microns in the center to 5 microns at the edge to balance the thermal expansion effect of the liquid crystal layer at high temperature. A higher concentration of liquid crystal monomers is added to the central area of ​​the liquid crystal layer, and a lower concentration of liquid crystal monomers is added to the edge area, so that the liquid crystal layer forms a structure with a gradually changing thickness from the center to the edge during the curing process. The concentration of the liquid crystal monomers is controlled to be 10% to 20% in the central area and 5% to 10% in the edge area. The thickness variation is described by Δd=d(T)-d0, where d(T) is the thickness of the liquid crystal layer at high temperature, d0 is the thickness of the liquid crystal layer at room temperature, and the thickness variation rate Δd / d0 of the liquid crystal layer is effectively controlled.

[0038] Table 3: Relationship between liquid crystal layer thickness change and temperature:

[0039]

[0040] The data in Table 3 can be used to better understand the thickness variation of the liquid crystal layer at different temperatures, thereby ensuring the color stability of the liquid crystal display in a high temperature environment;

[0041] 0.5% of photosensitive material and 1% of thermosensitive liquid crystal material are doped in the central area of ​​the liquid crystal layer, and 0.2% of photosensitive material and 0.5% of thermosensitive liquid crystal material are doped in the edge area. Under ultraviolet light irradiation, the expansion effect of the photosensitive material causes the thickness of the liquid crystal layer to gradually change from 8 microns in the center to 5 microns at the edge. The relationship between the thickness change Δd, the light intensity I and the irradiation time t is described by Δd=α.It, where α is the expansion coefficient of the photosensitive material. At the same time, when the ambient temperature rises from 25°C to 80°C, the expansion effect of the thermosensitive liquid crystal material also causes the thickness of the liquid crystal layer to gradually change from 8 microns in the center to 5 microns at the edge. The relationship between the thickness change Δd and the temperature change ΔT is described by Δd=β·ΔT, where β is the expansion coefficient of the thermosensitive liquid crystal material.

[0042] Adjust the angles of the upper and lower polarizers of the LCD screen according to temperature changes. When the temperature rises from 25°C to 80°C, the angle of the upper polarizer is adjusted from the initial 110° to 107°, and the angle of the lower polarizer is adjusted from the initial 105° to 112° to optimize the polarization effect. The polarized light intensity I = I0cos 2 (θ), where I0 is 1000cd / m 2 The change of the polarizer angle θ causes the light intensity I to change from 242cd / m 2 Change to 207cd / m 2 The background color of the liquid crystal display is light blue through the angle polarization of the upper and lower polarizers, and the background color changes less at high temperatures. The delay amount Δn×d of the liquid crystal layer is determined to be 0.89, where d is the box thickness of the liquid crystal layer, that is, the height of the middle of the sealing frame. The birefringence Δn of the liquid crystal decreases with the increase of temperature, and the smaller Δn is, the darker the background color of the liquid crystal display will be. When the delay amount Δn×d of the liquid crystal layer is 0.89, it changes smoothly at high temperatures, and the background color of the liquid crystal screen changes smoothly. By adding an automatic voltage regulation module to the driving circuit of the liquid crystal display, the automatic voltage regulation module adjusts the driving voltage in real time according to the feedback signal of the temperature sensor. When the ambient temperature rises, the automatic voltage adjustment module compensates for the thickness change of the liquid crystal layer by increasing the driving voltage. The relationship between the driving voltage V(t) and the temperature change ΔT is described by V(t)=V0+k.ΔT, where V0 is the initial driving voltage and k is the voltage compensation coefficient. The driving voltage is adjusted in real time to keep the thickness and birefringence of the liquid crystal layer stable at different temperatures. A plurality of micron-level adjustment grooves are set in the liquid crystal layer, and the depth of the adjustment grooves is in the range of 1 to 2 microns. By adjusting the depth and position of the adjustment grooves, the thickness change rate of the liquid crystal layer from the center to the edge is controlled within 0.1. Describe the relationship between the thickness change rate Δd / d and the thickness d(T) at high temperature and the thickness d0 at room temperature;

[0043] By adjusting the angles of the upper and lower polarizers of the LCD screen according to temperature changes, the polarization effect of the LCD screen is effectively optimized. When the temperature rises, the adjustment of the polarizer angle ensures that the change in light intensity is within a controllable range, thereby maintaining the color rendering effect of the LCD screen stable. By precisely controlling the angle changes of the upper and lower polarizers, the background color of the LCD screen changes less at high temperatures, ensuring the stability of the display effect.

[0044] Table 4: Relationship between temperature change and polarizer angle adjustment:

[0045] Temperature(℃) Upper polarizer angle (°) Lower polarizer angle (°) <![CDATA[Luminous intensity (cd / m 2 )]]> 25 110 105 1000 30 109 106 950 40 108 107 900 50 107 108 850 60 106 109 800 70 106 110 750 80 107 112 700

[0046] Table 4 shows the adjustment of the angles of the upper and lower polarizers of the liquid crystal display and their influence on the light intensity as the temperature changes. By adjusting the angles of the upper and lower polarizers, the change of the light intensity at different temperatures is ensured to be within a controllable range, and the color rendering effect of the liquid crystal display is kept stable; by controlling the change of the angle of the polarizer, the change of the light intensity is reduced, and the stability and consistency of the display effect are ensured;

[0047] Provides specific adjustment data of polarizer angle at different temperatures, showing how to cope with temperature changes by adjusting the polarizer angle;

[0048] By ensuring that the delay amount of the liquid crystal layer is 0.89, the change of the birefringence of the liquid crystal layer at high temperature is effectively controlled, and the change of the display background color is reduced. When the delay amount of the liquid crystal layer is 0.89, the background color of the liquid crystal display screen at high temperature changes smoothly, and the display effect is more stable;

[0049] Table 5: Relationship between liquid crystal layer delay and birefringence:

[0050] Temperature(℃) Delay (Δn×d) Birefringence change (Δn) 25 0.89 0.15 30 0.89 0.14 40 0.89 0.13 50 0.89 0.12 60 0.89 0.11 70 0.89 0.10 80 0.89 0.09

[0051] Table 5 shows the change of birefringence at different temperatures by controlling the delay of the liquid crystal layer Δn×d. By controlling the delay of the liquid crystal layer Δn×d, the change of birefringence at high temperature is ensured to be small, thereby reducing the change of the display background color. It shows how to keep the delay of the liquid crystal layer at 0.89 in a high temperature environment to minimize the change range of birefringence and ensure color stability:

[0052] By adding an automatic voltage regulation module to the driving circuit of the liquid crystal display, the driving voltage can be adjusted in real time to compensate for the thickness change of the liquid crystal layer. The feedback signal of the temperature sensor is used to control the automatic voltage regulation module. When the ambient temperature rises, the automatic voltage regulation module compensates for the thickness change of the liquid crystal layer by increasing the driving voltage.

[0053] Two layers of electrodes are arranged on the upper and lower surfaces of the liquid crystal layer, namely, the inner electrode and the outer electrode. The inner electrode is in direct contact with the liquid crystal layer, and the outer electrode is arranged on the outside of the inner electrode. By controlling the voltage of the inner electrode and the outer electrode respectively, the birefringence and thickness of the liquid crystal layer are adjusted. By Δn×d=(n e -n o )×d describes the delay Δn×d and the refractive index n of the unconventional light e 、Normal light refractive index n o The relationship between the thickness d of the liquid crystal layer and the delay amount of the liquid crystal layer is maintained stable at high temperatures. Two layers of electrodes are set on the upper and lower surfaces of the liquid crystal layer to achieve independent control of the birefringence and thickness of the liquid crystal layer. The inner electrode is in direct contact with the liquid crystal layer, and the arrangement of the liquid crystal molecules can be accurately adjusted, thereby affecting the birefringence of the liquid crystal layer. The outer electrode is set on the outside of the inner electrode. By applying different voltages, the thickness of the liquid crystal layer can be further fine-tuned. By controlling the voltages of the inner electrode and the outer electrode respectively, the delay amount of the liquid crystal layer can be accurately adjusted. In a high temperature environment, the birefringence of the liquid crystal will decrease with the increase of temperature, resulting in a worse color rendering effect of the liquid crystal display. By adjusting the voltages of the inner electrode and the outer electrode, this change can be compensated to keep the delay amount of the liquid crystal layer stable.

[0054] Table 6: Relationship between the voltage of the inner electrode and the outer electrode and the delay amount:

[0055] Inner electrode voltage (V) Outer electrode voltage (V) Delay (Δn×d) 1.0 0.5 0.89 1.2 0.6 0.89 1.4 0.7 0.89 1.6 0.8 0.89 1.8 0.9 0.89 2.0 1.0 0.89

[0056] Table 6 shows the influence of the voltage of the inner electrode and the outer electrode on the delay of the liquid crystal layer. By controlling the voltage of the inner electrode and the outer electrode respectively, the birefringence and thickness of the liquid crystal layer are adjusted to ensure that the delay of the liquid crystal layer is stable at high temperature. It is shown that under different voltages, the delay of the liquid crystal layer is maintained at 0.89, ensuring a stable display effect.

[0057] In the present embodiment, specifically, a thin interfacial lubricating layer is provided between each layer of material in the multilayer structure, and after depositing the high refractive index material layer, a high molecular polymer material is evaporated to form a lubricating layer with a thickness of 5 to 10 nanometers, the high molecular polymer material is any one of polyvinyl alcohol or polydimethylsiloxane, and the deposition temperature is controlled within the range of 60 to 80 degrees Celsius. After the lubricating layer is formed, the deposition of medium and low refractive index material layers is continued to form a thin interfacial lubricating layer to reduce the scattering effect at the interface. By providing a thin interfacial lubricating layer between each layer of material in the multilayer structure, the interface scattering effect between the material layers can be effectively reduced, and the optical performance of the multilayer structure can be significantly improved. The lubricating layer can fill the tiny gaps between the material layers to form a smooth interface, thereby reducing the scattering and reflection losses of light at the interface.

[0058] In the present embodiment, specifically, during the electric field application process, the arrangement state of the liquid crystal molecules is monitored in real time, and the strength of the applied electric field is adjusted by using a high-precision voltage controller. The variation range of the electric field strength is controlled within 0.1V / μm. At the same time, the time of applying the electric field is controlled between 10 and 30 seconds, so that the arrangement of the liquid crystal molecules reaches a stable state, and the laser interference method is used to monitor the spiral pitch of the liquid crystal molecules. The electric field parameters are adjusted according to the real-time monitoring data, so that the variation range of the spiral pitch of the liquid crystal molecules at high temperature is controlled within 0.01. By monitoring the arrangement state of the liquid crystal molecules in real time, the problem of uneven arrangement of the liquid crystal molecules caused by temperature changes can be discovered and corrected in time. The high-precision voltage controller can adjust the electric field strength in tiny increments to ensure that the variation range of the electric field strength is controlled within 0.1V / μm, so that the liquid crystal molecules can quickly reach an ideal spiral arrangement state when affected by the electric field.

[0059] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for stabilizing the color development of a liquid crystal display, characterized in that: include: A liquid crystal display screen with a liquid crystal layer is provided, wherein the liquid crystal display screen comprises an upper polarizer, an upper glass, an upper electrode, a sealing frame, a lower electrode, a lower glass and a lower polarizer, wherein the middle of the sealing frame has a liquid crystal layer, the upper polarizer and the lower polarizer are both dye-based wide-temperature blue polarizers, the initial polarization angle of the upper polarizer is 110°, and the initial polarization angle of the lower polarizer is 105°; A high refractive index material with a refractive index of 1.8, a medium refractive index material with a refractive index of 1.6, and a low refractive index material with a refractive index of 1.4 are arranged between the upper polarizer and the lower polarizer of the liquid crystal display screen. A multilayer structure is arranged in the order of high refractive index-medium refractive index-low refractive index to form a gradient optical structure. When the temperature changes, the gradient optical structure adjusts the transmittance and polarization of the liquid crystal layer through multiple reflections and refraction effects of light. When the ambient temperature rises from 25° C. to 80° C., the refractive index of the light passing through the material layer changes, so that the transmittance of the liquid crystal layer gradually decreases, while the polarization effect is optimized. The relationship between the transmittance T and the temperature change ΔT is described by the formula T=T0·exp(-k·ΔT), where T0 is the initial transmittance and k is the temperature sensitivity coefficient; Inside the liquid crystal layer, the arrangement of liquid crystal molecules is controlled so that the liquid crystal molecules are arranged in a spiral shape. Through the interaction between molecules, the liquid crystal layer maintains a stable birefringence Δ at high temperatures. n =n e -n o , where n e is the refractive index of unconventional light, n o The refractive index is the normal light refractive index. With this arrangement, the change of the birefringence of the liquid crystal layer at high temperature is reduced. The thickness gradient of the liquid crystal layer is controlled so that the thickness of the liquid crystal layer gradually changes from 8 microns in the center to 5 microns at the edge to balance the thermal expansion effect of the liquid crystal layer at high temperature. The change of thickness is described by Δd=d(T)-d0, where d(T) is the thickness of the liquid crystal layer at high temperature, d0 is the thickness of the liquid crystal layer at room temperature, and the thickness change rate of the liquid crystal layer Δd / d0 is effectively controlled. Adjust the angles of the upper and lower polarizers of the LCD screen according to temperature changes. When the temperature rises from 25°C to 80°C, the angle of the upper polarizer is adjusted from the initial 110° to 107°, and the angle of the lower polarizer is adjusted from the initial 105° to 112° to optimize the polarization effect. The polarized light intensity I = I0cos 2 (θ), where I0 is 1000cd / m 2 The change of the polarizer angle θ causes the light intensity I to change from 242cd / m 2 Change to 207cd / m 2 The angle polarization of the upper and lower polarizers makes the background color of the liquid crystal display light blue, and the background color changes little at high temperatures. The delay amount Δn×d of the liquid crystal layer is determined to be 0.89, where d is the box thickness of the liquid crystal layer, that is, the height of the middle of the sealing frame. The birefringence Δn of the liquid crystal decreases with increasing temperature, and the smaller Δn is, the darker the background color of the liquid crystal display will be. When the delay amount Δn×d of the liquid crystal layer is 0.89, it changes smoothly at high temperatures, and the background color of the liquid crystal screen changes smoothly.

2. A method for stabilizing the color development of a liquid crystal display according to claim 1, characterized in that: The multilayer structure is formed by layer-by-layer deposition by evaporation. A high refractive index material layer is deposited on the surface of the upper polarizer of the liquid crystal display screen. The refractive index of the high refractive index material is 1.

8. The deposition rate during the evaporation process is controlled within a range of 0.1 to 0.2 nanometers per second, and the evaporation temperature is controlled within a range of 150 to 200 degrees Celsius. Next, a medium refractive index material layer and a low refractive index material layer are sequentially deposited on the high refractive index material layer. The refractive index of the medium refractive index material is 1.6, and the refractive index of the low refractive index material is 1.

4. The deposition rate of the medium refractive index material layer is controlled within a range of 0.08 to 0.15 nanometers per second, and the evaporation temperature is controlled within a range of 140 to 190 degrees Celsius; the deposition rate of the low refractive index material layer is controlled within a range of 0.05 to 0.1 nanometers per second, and the evaporation temperature is controlled within a range of 130 to 180 degrees Celsius. The thickness of each layer of material is uniformly controlled within a range of 50 to 100 nanometers, forming a multilayer optical structure with precise thickness and refractive index gradient.

3. A method for stabilizing the color development of a liquid crystal display according to claim 1, characterized in that: A thin interfacial lubricating layer is arranged between each layer of material in the multilayer structure, and after depositing the high refractive index material layer, a high molecular polymer material is evaporated to form a lubricating layer with a thickness of 5 to 10 nanometers. The high molecular polymer material is any one of polyvinyl alcohol or polydimethylsiloxane, and the deposition temperature is controlled within the range of 60 to 80 degrees Celsius. After the lubricating layer is formed, the deposition of medium and low refractive index material layers is continued to form a thin interfacial lubricating layer to reduce the scattering effect at the interface.

4. The method for stabilizing the color development of a liquid crystal display according to claim 1, characterized in that: Liquid crystal molecules are arranged in a spiral shape in the liquid crystal layer by applying an electric field, the intensity of the electric field is 1 to 5V / μm, and the direction of the electric field is parallel to the initial arrangement direction of the liquid crystal molecules, so as to induce the liquid crystal molecules to be arranged along a spiral path. Specifically, electrodes are arranged on both sides of the liquid crystal layer, and the electrode material is a transparent conductive oxide. By controlling the voltage between the electrodes and applying an electric field, the liquid crystal molecules are arranged along the direction of the electric field. In the initial stage, the intensity of the applied electric field is set to 1V / μm, and the liquid crystal molecules begin to be arranged along the direction of the electric field. Then, the electric field intensity is gradually increased until it reaches 5V / μm. , so that the liquid crystal molecules are arranged along a spiral path, and the direction of the electric field remains parallel to the initial arrangement direction of the liquid crystal molecules, so that the liquid crystal molecules can form a stable spiral structure when subjected to the electric field. The relationship between the electric field strength E=V / d and the voltage V and the electrode spacing d, where d is the electrode spacing in microns. During the application of the electric field, the voltage increment is gradually adjusted and controlled within the range of 0.1 to 0.5V, and the temperature of the liquid crystal layer is kept stable at 25 to 30 degrees Celsius, so that the liquid crystal molecules can complete the spiral arrangement in a suitable temperature environment, forming a spirally arranged liquid crystal molecular structure.

5. A method for stabilizing color development of a liquid crystal display according to claim 4, characterized in that: During the electric field application process, the arrangement state of the liquid crystal molecules is monitored in real time, and the intensity of the applied electric field is adjusted using a high-precision voltage controller. The variation range of the electric field intensity is controlled within 0.1V / μm. At the same time, the time of applying the electric field is controlled between 10 and 30 seconds so that the arrangement of the liquid crystal molecules reaches a stable state. The laser interferometry method is used to monitor the spiral pitch of the liquid crystal molecules, and the electric field parameters are adjusted according to the real-time monitoring data so that the variation range of the spiral pitch of the liquid crystal molecules at high temperature is controlled within 0.

01.

6. The method for stabilizing the color development of a liquid crystal display according to claim 1, characterized in that: A higher concentration of liquid crystal monomers is added to the central area of ​​the liquid crystal layer, and a lower concentration of liquid crystal monomers is added to the edge area, so that the liquid crystal layer forms a structure with a thickness gradually changing from the center to the edge during the curing process. The concentration of the liquid crystal monomers is controlled at 10% to 20% in the central area and 5% to 10% in the edge area.

7. A method for stabilizing the color development of a liquid crystal display according to claim 1, characterized in that: 0.5% of photosensitive material and 1% of thermosensitive liquid crystal material are doped in the central area of ​​the liquid crystal layer, and 0.2% of photosensitive material and 0.5% of thermosensitive liquid crystal material are doped in the edge area. Under ultraviolet light irradiation, the expansion effect of the photosensitive material causes the thickness of the liquid crystal layer to gradually change from 8 microns in the center to 5 microns at the edge. The relationship between the thickness change Δd, the light intensity I and the irradiation time t is described by Δd=α·I·t, where α is the expansion coefficient of the photosensitive material. At the same time, when the ambient temperature rises from 25°C to 80°C, the expansion effect of the thermosensitive liquid crystal material also causes the thickness of the liquid crystal layer to gradually change from 8 microns in the center to 5 microns at the edge. The relationship between the thickness change Δd and the temperature change ΔT is described by Δd=β·ΔT, where β is the expansion coefficient of the thermosensitive liquid crystal material.

8. The method for stabilizing the color development of a liquid crystal display according to claim 1, characterized in that: An automatic voltage regulation module is added to the driving circuit of the liquid crystal display screen. The automatic voltage regulation module adjusts the driving voltage in real time according to the feedback signal of the temperature sensor. When the ambient temperature rises, the automatic voltage regulation module compensates for the thickness change of the liquid crystal layer by increasing the driving voltage. The relationship between the driving voltage V(t) and the temperature change ΔT is described by V(t)=V0+k·ΔT, where V0 is the initial driving voltage and k is the voltage compensation coefficient. By adjusting the driving voltage in real time, the thickness and birefringence of the liquid crystal layer at different temperatures are kept stable.

9. The method for stabilizing the color development of a liquid crystal display according to claim 1, characterized in that: By setting a plurality of micrometer-level adjustment grooves in the liquid crystal layer, the depth of the adjustment grooves is in the range of 1 to 2 micrometers, and by adjusting the depth and position of the adjustment grooves, the thickness change rate of the liquid crystal layer from the center to the edge is controlled within 0.

1. Describe the relationship between the thickness change rate Δd / d and the thickness d(T) at high temperature and the thickness d0 at room temperature.

10. The method for stabilizing the color development of a liquid crystal display according to claim 1, characterized in that: Two layers of electrodes are arranged on the upper and lower surfaces of the liquid crystal layer, namely, an inner electrode and an outer electrode. The inner electrode is in direct contact with the liquid crystal layer, and the outer electrode is arranged on the outside of the inner electrode. By controlling the voltage of the inner electrode and the outer electrode respectively, the birefringence and thickness of the liquid crystal layer are adjusted. By Δn×d=(n e -n o )×d describes the delay Δn×d and the refractive index n of the unconventional light e 、Normal light refractive index n o The relationship between the thickness of the liquid crystal layer d and the retardation amount at which the liquid crystal layer is kept stable at high temperatures.

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