Double-color light guide plate and Local dimming backlight module

Abstract

The invention discloses a double-color light guide plate and a Local dimming backlight module, and relates to the technical field of backlight modules, and the double-color light guide plate comprises a lower light guide layer and an upper light guide layer which are sequentially arranged from bottom to top; the lower light guide layer comprises a lens part, a lamp cup part and a lower frame body which are integrally arranged; the upper light guide layer comprises a light guide part and an upper frame body matched with the lower frame body; the upper end of the lower light guide layer is coated with a conductive coating, the upper end of the conductive coating is electrically connected with an electrochromic material layer, the conductive coating and the electrochromic material layer are arranged between the lower light guide layer and the upper light guide layer, and the upper end of the upper light guide layer is provided with a grating layer electrically connected with the conductive coating; through the efficient synergistic effect of the electrochromic material layer and the grating layer, the intensity and quality of output light are remarkably improved, the brightness and the light color of a light source are automatically adjusted according to real-time environment light changes, the requirements in different use scenes are met, light output is accurately controlled, and unnecessary light loss is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field related to backlight modules, in particular to a dual-color light guide plate and a local dimming backlight module. Background Art

[0002] A liquid crystal display mainly includes a liquid crystal display panel and a backlight module, wherein the backlight module is arranged on the back of the liquid crystal display panel to provide white light for the liquid crystal display panel, and the liquid crystal display panel converts the white light emitted by the backlight module into colorful patterns on the front side of the liquid crystal display panel, thereby realizing the display function of the liquid crystal display. Therefore, the backlight module is an important component of the liquid crystal display. With the development of technology, local dimming technology has emerged. Local dimming technology can control the brightness of the light at a local position of the backlight module, thereby better controlling the display effect of the liquid crystal display.

[0003] Publication number CN116224483A discloses a two-color light guide plate and a Local dimming backlight module, including a lamp cup layer and a lens layer. The lens layer is arranged at the front side of the lamp cup layer. The lamp cup layer and the lens layer are integrally injection molded. The lamp cup layer is made of white plastic injection molding, and the lens layer is made of transparent plastic injection molding. The lamp cup layer includes a plurality of lamp cups, and the lens layer includes a plurality of lenses, and a lens is arranged at the front side of each lamp cup. The Local dimming backlight module includes a rear mounting groove, a light-emitting component, a two-color light guide plate, a diaphragm component and a front fixing frame. The two-color light guide plate is the aforementioned two-color light guide plate. The light-emitting component includes a lamp board, which is compatible with the two-color light guide plate. A plurality of Mini LED light sources are arranged on the lamp board, and each Mini LED light source is respectively installed in a lamp cup.

[0004] However, existing backlight modules still have some problems when in use, such as: the light intensity cannot be adjusted quickly and effectively under different environmental and scene conditions to adapt to the user's visual needs, which affects the user's normal usage experience, and also causes unnecessary light loss, thereby increasing the energy consumption of the device. Summary of the invention

[0005] In order to solve the defects in the prior art, the present invention provides a dual-color light guide plate and a local dimming backlight module.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: The present invention provides a two-color light guide plate, comprising A lower light guide layer and an upper light guide layer are sequentially arranged from bottom to top; The lower light guide layer includes a lens portion, a lamp cup portion and a lower frame body which are integrally arranged; The upper light guide layer includes a light guide portion and an upper frame body matched with the lower frame body; The upper end of the lower photoconductive layer is coated with a conductive coating, the upper end of the conductive coating is electrically connected to an electrochromic material layer, the conductive coating and the electrochromic material layer are arranged between the lower photoconductive layer and the upper photoconductive layer, and the upper end of the upper photoconductive layer is provided with a grating layer electrically connected to the conductive coating.

[0007] As a preferred technical solution of the present invention, the refractive index of the material used for the lower light-guiding layer is greater than the refractive index of the material used for the upper light-guiding layer.

[0008] As a preferred technical solution of the present invention, the light transmittance of the electrochromic material layer is adjusted by the voltage applied by the conductive coating.

[0009] As a preferred technical solution of the present invention, the structure of the grating layer is adjusted by the voltage applied by the conductive coating.

[0010] The present invention also provides a Local dimming backlight module, including a lower frame, a light-emitting component, a film plate assembly and an upper frame, wherein the light-emitting component is arranged inside the lower frame, the two-color light guide plate is arranged at the upper end of the light-emitting component and is fixedly connected to the lower frame, the film plate assembly is arranged at the upper end of the two-color light guide plate and is fixedly connected to the upper frame, and the upper frame is fixedly connected to the lower frame.

[0011] As a preferred technical solution of the present invention, a control system based on a local dimming backlight module is also included, comprising the following steps: The processing unit obtains the ambient light and display content information in real time through the light sensor; The processing unit controls the conductive coating to work based on the control system algorithm, and applies voltage to the electrochromic material layer and the grating layer; The electrochromic material layer changes its light transmittance and color under the action of applied voltage. The transmittance T ECD The relationship between (V) and applied voltage is described by the following formula: ; Wherein, T0 ratio represents the initial transmittance, k represents the proportionality constant related to the properties of the electrochromic material, V represents the applied voltage, and n represents the material response characteristic index; The grating layer adjusts the response when voltage is applied, thereby adjusting the wavelength and intensity of the transmitted light. The adjustment response RG (V, λ) of the grating layer when voltage V is applied is described by the following formula: ; Among them, R0 represents the static reflectivity of the grating, α represents the adjustment amplitude, and d g is the period of the grating, is the phase, d g / λ g Determines the diffraction characteristics of the grating; To achieve precise adjustment of the backlight module, the control algorithm of the output light intensity Iout of the control system based on the local dimming backlight module is: ; Among them, I out is the output light intensity, I in is the input light intensity, T ECD (V) represents the transmittance of the electrochromic material layer, R G (V, λ) is the adjustment response of the grating layer to a specific wavelength λ, d is the thickness of the electrochromic material layer, λ0 is the reference wavelength, is an exponential decay factor, which represents the light attenuation effect caused by the thickness d of the electrochromic material layer, (1-T ECD ) is a correction term, which reflects the influence of the transmittance of the electrochromic material layer on the input light intensity.

[0012] As a preferred technical solution of the present invention, the processing unit detects the output light intensity I out , and then obtain the output light intensity I out and the expected light intensity I desired The error between E=I desired -I out , and then use the PID controller to dynamically adjust the applied voltage V. The adjustment formula is: ; Among them, K p , K i and K d are the proportional, integral and derivative gain parameters respectively.

[0013] As a preferred technical solution of the present invention, frequency modulation is added to the light-emitting component, and the output wavelength is dynamically adjusted by adjusting the frequency f. The adjustment response is expressed by the following formula: ; Where A is the wavelength adjustment amplitude, is the initial phase, and t is the time variable.

[0014] As a preferred technical solution of the present invention, the parameter K of the PID controller is p , K i and K d Optimization is performed through adaptive algorithms.

[0015] As a preferred technical solution of the present invention, the range of the frequency modulation f is between 1 kHz and 10 kHz.

[0016] The beneficial effects of the present invention are: The present invention significantly improves the intensity and quality of the output light through the efficient synergistic effect of the electrochromic material layer and the grating layer, thereby improving the picture clarity and color reproduction of the display device. The system can automatically adjust the brightness and light color of the light source according to real-time ambient light changes to meet the needs of different usage scenarios, thereby providing a better user experience. In addition, by accurately controlling light output and reducing unnecessary light loss, the overall energy efficiency of the light source is improved, achieving an energy-saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of the overall structure of the two-color light guide plate of the present invention.

[0018] Figure 2 It is a schematic diagram of the exploded structure of the dual-color light guide plate of the present invention.

[0019] Figure 3 It is a schematic structural diagram of the backlight module of the present invention.

[0020] Figure 4 It is a flow chart of the backlight module control system of the present invention.

[0021] In the figure: 1. lower light-conducting layer; 11. lens part; 12. lamp cup part; 13. lower frame; 2. upper light-conducting layer; 21. light-conducting part; 22. upper frame; 3. conductive coating; 4. electrochromic material layer; 5. grating layer; 6. lower frame assembly; 7. light-emitting assembly; 8. membrane assembly; 9. upper frame assembly. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0023] Embodiment 1 like Figure 1-Figure 2 As shown, the two-color light guide plate includes A lower light guide layer 1 and an upper light guide layer 2 are arranged sequentially from bottom to top; The lower light guide layer 1 includes a lens portion 11, a lamp cup portion 12 and a lower frame 13 which are integrally arranged; The upper light guide layer 2 includes a light guide portion 21 and an upper frame 22 matched with the lower frame 13; The upper end of the lower photoconductive layer 1 is coated with a conductive coating 3, the upper end of the conductive coating 3 is electrically connected to an electrochromic material layer 4, the conductive coating 3 and the electrochromic material layer 4 are arranged between the lower photoconductive layer 1 and the upper photoconductive layer 2, and the upper end of the upper photoconductive layer 2 is provided with a grating layer 5 electrically connected to the conductive coating 3.

[0024] Among them, the present invention significantly improves the intensity and quality of the output light through the efficient synergistic effect of the electrochromic material layer 4 and the grating layer 5, thereby improving the picture clarity and color reproduction of the display device. The system can automatically adjust the brightness and light color of the light source according to real-time ambient light changes to meet the needs of different usage scenarios, thereby providing a better user experience. In addition, by accurately controlling light output and reducing unnecessary light loss, the overall energy efficiency of the light source is improved to achieve energy-saving effects.

[0025] It should be noted that the lower frame 13 and the upper frame 22 are made of light and high-strength materials, such as aluminum alloy or magnesium alloy, to reduce the weight of the backlight module.

[0026] Further, if Figure 1-Figure 2 As shown, the refractive index of the material used for the lower light guide layer 1 is greater than the refractive index of the material used for the upper light guide layer 2. The lower light guide layer 1 is made of polycarbonate or polypropylene material, and the upper light guide layer 2 is made of polyethylene or acrylic material.

[0027] The design of each layer of material aims to comprehensively utilize the different optical properties of the above materials. By adjusting the layer thickness and arrangement, the light can be more evenly distributed inside the light guide plate, improving the lighting uniformity of the display. By optimizing the refractive index of each layer, it is ensured that the display can provide stable brightness and color at different viewing angles.

[0028] The lower light guide layer 1 is made of a high refractive index material, so the high refractive index helps to enhance the focusing and guiding of light, and the excellent light transmittance can reduce light loss, and the weather resistance is strong, and the physical and optical properties can be maintained under different environmental conditions; The upper optical waveguide layer 2 is made of a low refractive index material. The lower refractive index helps to achieve softer light diffusion, has good transparency and color reproduction, and can improve color performance. In addition, the lower refractive index is easy to process and can achieve different thickness configurations to optimize the display effect, making it easier to assemble with the upper conductive coating 3, electrochromic material layer 4 and grating layer 5.

[0029] When designing a double-layer light guide plate, the arrangement order of the light guide layers has an important influence on its optical performance and display effect. Therefore, the lower light guide layer 1 is set on the lower layer, which has excellent light guiding ability, so that the incident light can be better transmitted to the upper layer. When it is on the bottom layer, it can directly guide the light emitted by the light source, reduce light loss, and improve light utilization; setting the upper light guide layer 2 on the upper layer helps to achieve higher light diffusion and can make the light distribution more uniform. When it is on the upper layer, it can softly diffuse the incident light, so that the final output light is uniform, improve the display effect, and thus increase visual comfort. Such a configuration can make full use of the optical properties of the material to achieve better lighting uniformity and color performance.

[0030] It should be noted that the thickness of the lower light guide layer 1 is 1-3mm, and the thickness of the upper light guide layer 2 is 2-5mm. When the thickness of the lower light guide layer 1 is about 1mm, it is suitable for application in small devices. When the thickness of the lower light guide layer 1 is about 3mm, it is suitable for application in panels of large devices. When the thickness of the lower light guide layer 1 is about 2mm, it is suitable for providing soft diffusion for smaller displays. When the thickness of the lower light guide layer 1 is about 5mm, it is suitable for large-size, high-brightness displays. In actual use, the appropriate thickness needs to be selected to ensure that the lower light guide layer 1 effectively guides the light to the upper light guide layer 2, and at the same time, the light is evenly diffused in the upper light guide layer 2.

[0031] Further, if Figure 1-Figure 2 As shown, the light transmittance of the electrochromic material layer 4 is adjusted by the voltage applied by the conductive coating 3, wherein the liquid crystal display unit can be combined with the light guide plate to adjust the color output of the light guide plate according to the input signal, and the design of the transparent conductive coating 3 ensures that the current is evenly distributed to the electrochromic material layer 4, thereby optimizing its response time and transmittance adjustment accuracy.

[0032] Optionally, the transparent conductive coating 3 provides an electrode for the electrochromic material, and the transparent conductive coating 3 uses indium tin oxide (ITO) or other conductive polymer materials to ensure high light transmittance and allow current to pass to control the optical properties of the electrochromic material and the structure of the grating; The electrochromic material layer 4 realizes dynamic regulation of light by changing its chemical state or optical properties such as color, light transmittance, etc. when voltage is applied. The material may be a polymer electrochromic material or an inorganic electrochromic material (such as bismuth lithium salt, etc.); The grating layer 5 selectively adjusts and distributes the wavelength and intensity of the transmitted light, and utilizes the grating effect to enhance or weaken the transmission of light of a specific wavelength. The material is a photosensitive polymer or a metal coating, and the structure of the grating is adjusted by an electric field.

[0033] Embodiment 2 Among them, the components that are the same as or corresponding to those in Embodiment 1 adopt the corresponding reference numerals in Embodiment 1. For the sake of simplicity, only the differences from Embodiment 1 are described below. The differences between this Embodiment 2 and Embodiment 1 are as follows: As Figure 3 shown, the present invention also provides a Localdimming backlight module, including a lower frame assembly 6, a light-emitting assembly 7, a template assembly 8, and an upper frame assembly 9. The light-emitting assembly 7 is disposed inside the lower frame assembly 6. The dual-color light guide plate is disposed at the upper end of the light-emitting assembly 7 and fixedly connected to the lower frame assembly 6. The template assembly 8 is disposed at the upper end of the dual-color light guide plate and fixedly connected to the upper frame assembly 9. The upper frame assembly 9 is fixedly connected to the lower frame assembly 6.

[0034] Among them, the light-emitting assembly 7 can be an LED source or a laser source to ensure that the emitted light effectively enters the light guide layer. The template assembly 8 includes a diffusion plate and a brightness enhancement film to improve the uniformity and brightness of the backlight module.

[0035] Further, as Figure 4 shown, it also includes a control system based on the Localdimming backlight module, including the following steps: The processing unit obtains ambient light and display content information in real time through a light sensor; The processing unit controls the operation of the conductive coating 3 based on the control system algorithm and applies voltages to the electrochromic material layer 4 and the grating layer 5; The electrochromic material layer 4 changes its light transmittance and color under the action of the applied voltage, thereby affecting the brightness and color output of the entire backlight system. The transmittance T ECD (V) of the electrochromic material layer 4 changes with the applied voltage and is described by the following formula: ; Among them, T0 represents the initial transmittance, k represents a proportional constant related to the characteristics of the electrochromic material, which reflects the sensitivity of the material to voltage changes. The larger the value of k, the more sensitive the transmittance of the material is to voltage changes. V is the applied voltage, n represents the material response characteristic index, and the value of n is usually greater than 0 and will affect the shape of the curve. If n = 1, the relationship is linear; if n > 1, the relationship is non-linear, and as the voltage increases, the transmittance change will accelerate; if 0 < n < 1, the relationship is non-linear, and as the voltage increases, the transmittance change will slow down; The adjustment response of the grating layer 5 under the state of the applied voltage, and then adjusts the wavelength and intensity of the transmitted light. The adjustment response RG(V, λ) of the grating layer 5 under the state of the applied voltage V is described by the following formula: ; Among them, R0 represents the static reflectivity of the grating, that is, the reflectivity when there is no voltage applied, α represents the adjustment amplitude, which determines the range of change of the grating reflectivity, and d g is the period of the grating, is the phase term, which is related to the manufacturing process of the grating or other factors. g / λ g Determines the diffraction characteristics of the grating, which is related to the grating period and wavelength; Realize precise adjustment of the backlight module, based on the local dimming backlight module control system output light intensity I out The control algorithm is: ; Among them, I out is the output light intensity, I in is the input light intensity, which refers to the initial light intensity generated in the light source module. This is the starting light source of the system. ECD (V) is the transmittance of the electrochromic material layer. The electrochromic material can adjust its transmittance under different voltages to control the amount of light passing through. R G (V, λ) is the adjustment response of the grating layer 5 to the specific wavelength λ, which determines the degree to which the light of the specific wavelength can be reflected or transmitted by the grating layer 5. This parameter affects the color and intensity of the output light. d is the thickness of the electrochromic material layer 4. λ0 is the reference wavelength. is the exponential decay factor, which represents the light attenuation effect caused by the thickness d of the electrochromic material layer 4. This factor indicates that as the thickness of the light passing through the material layer increases, the light intensity will decay exponentially, (1-T ECD ) is a correction term, which reflects the influence of the transmittance of the electrochromic material layer 4 on the input light intensity, indicating that the absorbance of the electrochromic layer is related to the thickness d and the reference wavelength λ0, and is also related to the transmittance T ECD Inversely proportional, the higher the transmittance, the less the absorption, and the closer the exponential term is to 1; the lower the transmittance, the more the absorption, and the closer the exponential term is to 0.

[0036] The core function of this control algorithm is to accurately adjust the optical properties of the backlight module to meet the needs of different application scenarios. By combining the input light intensity with the optical properties of each layer of material, the system can calculate the output light intensity. By adjusting the transmittance of the electrochromic material and the adjustment response of the grating in real time, the backlight module can adapt to different ambient lighting conditions and display requirements. And the control system adjusts R G (V, λ), to adjust the color of the output light and ensure that the device can provide the best visual experience in different display modes (such as high-definition video playback, game mode, etc.); The algorithm allows the system to dynamically adjust transmittance and reflectivity based on real-time data, enhancing the system's response speed and providing smoother visual effects, which is especially important for high dynamic range (HDR) displays in near-use scenarios; By optimizing light intensity and color output, it may reduce visual fatigue during long-term viewing, and improve the comfort and viewing experience of display devices; By dynamically optimizing light output, the system can achieve higher energy efficiency and extend the service life of the equipment while ensuring visual quality.

[0037] It should be noted that the processing unit uses a digital signal processor (DSP) or a microcontroller unit (MCU) to implement the control algorithm.

[0038] Furthermore, the control system algorithm includes a feedback control loop for real-time monitoring of the ambient light intensity and the display content, and adjusting the voltage applied to the electrochromic material layer 4 and the grating layer 5 according to the preset target brightness and color temperature. Specifically, the processing unit detects the output light intensity I out , and then obtain the output light intensity I out and the expected light intensity I desired The error between E=I desired -I out For example, in bright environments, I desired will be set to a higher value. At the same time, a higher I desired , and in a dark environment, it will be set to a lower value, and then the PID controller will be used to dynamically adjust the applied voltage V. The adjustment formula is: ; Among them, K p , K i and K d are proportional, integral and differential gain parameters respectively, and the parameter K of the PID controller p , K i and K d Optimization is performed through adaptive algorithms to improve the system's response speed and stability.

[0039] K p The E proportional term directly adjusts the output voltage according to the current error. p is the proportional gain, which determines the response speed of the proportional term to the error, K p The larger the value, the faster the response, but it may cause system overshoot or oscillation; The integral term accumulates past errors and is used to eliminate steady-state errors, K i is the integral gain, which determines the response speed of the integral term to the accumulated error, Ki The larger it is, the stronger the ability to eliminate steady-state errors is; The derivative term is adjusted according to the rate of change of the error and is used to predict future errors so that adjustments can be made in advance to reduce overshoot and oscillation. d The larger the value, the stronger the anti-disturbance capability is, but it may increase the noise sensitivity of the system.

[0040] The feedback control loop uses a PID controller to dynamically adjust the voltage applied to the electrochromic material layer 4 and the grating layer 5 to achieve the output light intensity I out Precise control.

[0041] Furthermore, frequency modulation is added to the light emitting component 7, and the output wavelength is dynamically adjusted by adjusting the frequency f. The adjustment response is expressed by the following formula: ; Where A is the wavelength adjustment amplitude, is the initial phase, and t is the time variable.

[0042] Through the electrochromic material layer 4, the grating layer 5 and frequency modulation, precise control of light intensity and wavelength is achieved, and the system dynamically adjusts parameters according to ambient light and display content to adapt to different scene requirements.

[0043] It should be noted that the frequency modulation f ranges from 1 kHz to 10 kHz to avoid flickering visible to the human eye.

[0044] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Two-color light guide plate, characterized in that: include A lower light guide layer (1) and an upper light guide layer (2) are arranged in sequence from bottom to top; The lower light guide layer (1) comprises a lens portion (11), a lamp cup portion (12) and a lower frame (13) which are integrally arranged; The upper light-guiding layer (2) comprises a light-guiding portion (21) and an upper frame (22) matched with the lower frame (13); The upper end of the lower light-conducting layer (1) is coated with a conductive coating (3), the upper end of the conductive coating (3) is electrically connected to an electrochromic material layer (4), the conductive coating (3) and the electrochromic material layer (4) are arranged between the lower light-conducting layer (1) and the upper light-conducting layer (2), and the upper end of the upper light-conducting layer (2) is provided with a grating layer (5) electrically connected to the conductive coating (3).

2. The two-color light guide plate according to claim 1, characterized in that: The refractive index of the material used for the lower light-guiding layer (1) is greater than the refractive index of the material used for the upper light-guiding layer (2).

3. The two-color light guide plate according to claim 1, characterized in that: The light transmittance of the electrochromic material layer (4) is adjusted by the voltage applied by the conductive coating (3).

4. The two-color light guide plate according to claim 1, characterized in that: The structure of the grating layer (5) is adjusted by the voltage applied by the conductive coating (3).

5. A local dimming backlight module, comprising a two-color light guide plate as claimed in any one of claims 1 to 4, characterized in that: It also comprises a lower frame assembly (6), a light-emitting assembly (7), a film assembly (8) and an upper frame assembly (9), wherein the light-emitting assembly (7) is arranged inside the lower frame assembly (6), the two-color light guide plate is arranged at the upper end of the light-emitting assembly (7) and is fixedly connected to the lower frame assembly (6), the film assembly (8) is arranged at the upper end of the two-color light guide plate and is fixedly connected to the upper frame assembly (9), and the upper frame assembly (9) is fixedly connected to the lower frame assembly (6).

6. The Local dimming backlight module according to claim 5, characterized in that: Also included is a control system based on the Local dimming backlight module, comprising the following steps: The processing unit obtains the ambient light and display content information in real time through the light sensor; The processing unit controls the operation of the conductive coating (3) based on a control system algorithm, and applies voltage to the electrochromic material layer (4) and the grating layer (5); The electrochromic material layer (4) changes its light transmittance and color under the action of applied voltage. The transmittance T of the electrochromic material layer (4) is ECD The relationship between (V) and applied voltage is described by the following formula: ； Wherein, T0 ratio represents the initial transmittance, k represents the proportionality constant related to the properties of the electrochromic material, V represents the applied voltage, and n represents the material response characteristic index; The grating layer (5) has an adjustment response when a voltage is applied, thereby adjusting the wavelength and intensity of the transmitted light. The adjustment response RG (V, λ) of the grating layer (5) when a voltage V is applied is described by the following formula: ； Among them, R0 represents the static reflectivity of the grating, α represents the adjustment amplitude, and d g is the period of the grating, is the phase, d g / λ g Determines the diffraction characteristics of the grating; To achieve precise adjustment of the backlight module, the control algorithm of the output light intensity Iout of the control system based on the local dimming backlight module is: ； Among them, I out is the output light intensity, I in is the input light intensity, T ECD (V) represents the transmittance of the electrochromic material layer, R G (V, λ) is the adjustment response of the grating layer to a specific wavelength λ, d is the thickness of the electrochromic material layer (4), λ0 is the reference wavelength, is an exponential decay factor, which represents the light attenuation effect caused by the thickness d of the electrochromic material layer, (1-T ECD ) is a correction term, which reflects the influence of the transmittance of the electrochromic material layer on the input light intensity.

7. The Local dimming backlight module according to claim 6, characterized in that: The processing unit detects the output light intensity I out , and then obtain the output light intensity I out and the expected light intensity I desired The error between E=I desired -I out , and then use the PID controller to dynamically adjust the applied voltage V. The adjustment formula is: ； Among them, K p , K i and K d are the proportional, integral and derivative gain parameters respectively.

8. The Local dimming backlight module according to claim 7, characterized in that: Frequency modulation is added to the light-emitting component (7) to achieve dynamic adjustment of the output wavelength by adjusting the frequency f. The adjustment response is expressed by the following formula: ； Where A is the wavelength adjustment amplitude, is the initial phase, and t is the time variable.

9. The Local dimming backlight module according to claim 7, characterized in that: PID controller parameter K p , K i and K d Optimization is performed through adaptive algorithms.

10. The local dimming backlight module according to claim 8, characterized in that: The frequency modulation f ranges from 1kHz to 10kHz.

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