Backlight white balance control method and device, electronic equipment and storage medium

Abstract

The application relates to a backlight white balance control method and device, electronic equipment and a storage medium. The method comprises the following steps: constructing a multi-temperature three-dimensional lookup table set; detecting the current working temperature of a backlight module when an image is displayed on a backlight display device, and determining the target light output characteristics of the current display picture; selecting a target three-dimensional lookup table from the multi-temperature three-dimensional lookup table set according to the current working temperature; inputting the target luminance value and the target chroma coordinate into the target three-dimensional lookup table to obtain a target three-color driving current value and generate a driving signal, and driving the backlight module to output mixed light matched with the target light output characteristics, so as to realize backlight white balance control. Based on the luminance, chroma and three-color driving current mapping relationship of the backlight, the mixed light meeting the target white balance requirement can be quickly and accurately output, the chroma coupling error caused by the traditional independent correction of the sub-channel is avoided, and the control precision and response speed of the backlight white balance are improved.

Description

Technical Field

[0001] This application relates to the field of image processing technology, and in particular to a backlight white balance control method, device, electronic device and storage medium. Background Technology

[0002] In the high-end LCD display field, RGB-Mini LED backlighting technology, with its independently controllable red, green, and blue LED chips, can directly mix and generate the target color light. This achieves a wide color gamut coverage and high color purity far superior to traditional white backlighting combined with color filters, making it the mainstream technology for display devices pursuing ultimate image quality. To ensure the color accuracy of the displayed image, white balance calibration and dynamic control are the core technical aspects of RGB-Mini LED backlighting display devices. Currently, the mainstream white balance calibration schemes in the industry are mainly divided into two categories. One is a linear correction method based on gamma curves and gain / offset, which completes calibration at a fixed brightness level by setting independent gamma curves and gain parameters for the R, G, and B channels respectively. The other is a calibration method based on one-dimensional or two-dimensional lookup tables, which independently compensates each color channel through a lookup table to handle the nonlinearity of photoelectric response. Both methods are designed around the concept of forward calibration for independent channels.

[0003] However, while existing RGB backlight white balance calibration technology can guarantee color accuracy at medium to high brightness to a certain extent, it cannot solve the problem of white point shift in the RGB three-color backlight module across the entire brightness range. It has many technical defects and is difficult to meet the image quality requirements of high-end display devices.

[0004] Firstly, existing technologies treat the R, G, and B channels as independent variables, neglecting the complex three-dimensional coupling nonlinear relationship between the driving current, light output brightness, and output light chromaticity coordinates of the three-color LEDs. This makes it impossible to model and compensate for the different nonlinear responses of the three-color LEDs under different driving currents due to differences in materials and physical properties, which is the root cause of the color shift in mixed white light. Secondly, the light output signal of LEDs is weak, the measurement noise is large, and the nonlinear effect is most severe under low drive current. Existing calibration schemes lack effective calibration points in this low brightness area or only perform coarse-grained calibration, which makes it easy for visible color shifts such as "green fog" and "purple fring" to appear when display devices present dark scenes, seriously damaging the color accuracy of dark details. Third, most existing solutions are static calibrations performed only once at the factory, without considering the dynamic drift of LED photoelectric characteristics as the chip junction temperature rises and usage time accumulates. Static calibration data cannot track such changes, causing the white balance accuracy of the equipment to gradually deteriorate and the color accuracy to continuously decline after different ambient temperatures or long-term use.

[0005] Therefore, there is an urgent need to develop a backlight white balance control method, device, electronic equipment, and storage medium to solve one or more of the aforementioned problems. Summary of the Invention

[0006] In view of this, to solve the above-mentioned technical problems or some of them, embodiments of this application provide a backlight white balance control method, device, electronic device, and storage medium. This method establishes a global mapping relationship between the brightness, chromaticity, and three-color driving current of the backlight, enabling rapid and accurate output of mixed light that meets the target white balance requirements. This avoids the chromaticity coupling error caused by traditional independent channel calibration, improving the control accuracy and response speed of the backlight white balance. Simultaneously, establishing a lookup table for different temperatures effectively compensates for the drift caused by temperature changes to the photoelectric characteristics of the backlight module, ensuring that the backlight maintains a stable and consistent white balance output at different operating temperatures, significantly improving the accuracy and reliability of displayed colors.

[0007] In a first aspect, this application provides a backlight white balance control method, comprising: Construct a set of three-dimensional lookup tables for multiple temperatures, the set of three-dimensional lookup tables for multiple different preset temperatures; When displaying images in a backlit display device, the current operating temperature of the backlight module is detected, and the target light output characteristics of the current display screen are determined. The target light output characteristics include the target brightness value and the target chromaticity coordinates corresponding to the target white balance. Based on the current operating temperature, a suitable three-dimensional lookup table is selected from the set of multi-temperature three-dimensional lookup tables as the target three-dimensional lookup table; Using the target brightness value and target chromaticity coordinates as input, the target three-dimensional lookup table is queried to obtain the target three-color driving current value that matches the target light output characteristics; A driving signal is generated based on the target three-color driving current value to drive the backlight module to output mixed light that matches the target light output characteristics, so as to achieve backlight white balance control.

[0008] In one possible implementation, the process of constructing the multi-temperature three-dimensional lookup table set includes: Under temperature control, for any preset temperature, a three-dimensional lookup table is constructed with light output characteristics as input and three-color driving current values ​​that realize the light output characteristics as output. The light output characteristics include luminance values ​​and chromaticity coordinates. Integrate all preset temperature 3D lookup tables to form a multi-temperature 3D lookup table set.

[0009] In one possible implementation, constructing a three-dimensional lookup table that takes the target light output characteristics as input and outputs the three-color driving current values ​​that achieve the target light output characteristics includes: Traverse the three-color driving current combination space of the backlight module, collect the actual output brightness and actual chromaticity coordinates of the backlight module at the preset temperature, and store the collected actual output brightness, actual chromaticity coordinates and corresponding driving current values ​​into the feature database. Define the target mesh in the standard color space and refine the brightness dimension of the low-brightness areas; For each target light output feature point in the target grid, the optimal three-color driving current value corresponding to each target light output feature point is obtained by inverse solution based on the feature database. Based on the mapping relationship between each target light output feature point and the corresponding optimal three-color driving current value, a three-dimensional lookup table for the preset temperature is generated.

[0010] In one possible implementation, the step of performing inverse solving based on the feature database to obtain the optimal three-color driving current value corresponding to each target light output feature point includes: Based on the target light output feature of the target light output feature point, multiple sets of actual output brightness, actual chromaticity coordinates and corresponding initial values ​​of three-color driving current are determined in the feature database to match the target light output feature point. Obtain the pre-set comprehensive evaluation index of color difference and brightness deviation, and construct an optimization solution model with the minimum deviation of the feature parameters of the actual output brightness, actual chromaticity coordinates and target light output feature points as the optimization objective; An optimization algorithm is used to iteratively calculate the optimization solution model to obtain the three-color driving current value that makes the comprehensive evaluation index optimal, which is then used as the optimal three-color driving current value corresponding to the target light output feature point.

[0011] In one possible implementation, the method further includes: If no three-dimensional lookup table adapted to the current working temperature is found in the set of multi-temperature three-dimensional lookup tables, obtain at least two three-dimensional lookup tables corresponding to the current working temperature and adjacent preset temperatures. Interpolation processing is performed on the three-dimensional lookup tables corresponding to at least two adjacent preset temperatures to generate a three-dimensional lookup table adapted to the current working temperature.

[0012] In one possible implementation, the step of interpolating the three-dimensional lookup tables corresponding to the at least two adjacent preset temperatures to generate a three-dimensional lookup table adapted to the current operating temperature includes: Interpolation calculations are performed in the three-dimensional lookup table corresponding to at least two adjacent preset temperatures to obtain a set of three-color drive current values ​​corresponding to each adjacent preset temperature. Based on the temperature difference between the current operating temperature and the at least two adjacent preset temperatures, determine the interpolation weight of the three-color drive current value group corresponding to each adjacent preset temperature. Based on the interpolation weight, a weighted interpolation calculation is performed on the three-color drive current value group corresponding to the at least two adjacent preset temperatures to obtain a three-color drive current value group that is adapted to the current working temperature. Based on the mapping relationship between the target light output characteristics and the three-color drive current value group adapted to the current operating temperature, a three-dimensional lookup table adapted to the current operating temperature is generated.

[0013] In one possible implementation, during the process of acquiring the actual output brightness and actual chromaticity coordinates of the backlight module, the current sampling interval used in the low current range is smaller than the current sampling interval in the medium-high current range. The low current range is the current range from near zero current to a preset low-proportion rated current, and the medium-high current range is the current range above the preset low-proportion rated current.

[0014] Secondly, this application provides a backlight white balance control device, the device comprising: A construction module is used to construct a set of multi-temperature three-dimensional lookup tables, which includes multiple three-dimensional lookup tables with different preset temperatures. The detection module is used to detect the current operating temperature of the backlight module when the backlight display device is displaying an image, and to determine the target light output characteristics of the current display screen. The target light output characteristics include the target brightness value and the target chromaticity coordinates corresponding to the target white balance. The selection module is used to select a suitable three-dimensional lookup table from the set of multi-temperature three-dimensional lookup tables based on the current operating temperature, and use it as the target three-dimensional lookup table. The matching module is used to query the target three-dimensional lookup table with the target brightness value and target chromaticity coordinates as input to obtain the target three-color driving current value that matches the target light output characteristics; The driving module is used to generate a driving signal based on the target three-color driving current value, and drive the backlight module to output mixed light that matches the target light output characteristics, so as to realize backlight white balance control.

[0015] Thirdly, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the backlight white balance control method described in any embodiment of the first aspect.

[0016] Fourthly, this application also provides a computer storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the backlight white balance control method described in any embodiment of the first aspect.

[0017] Compared with the prior art, the technical solution provided in this application has the following advantages: The method provided in this application adopts the aforementioned backlight white balance control method, which establishes a global mapping relationship between the brightness, chromaticity, and three-color driving current of the backlight. This enables the rapid and accurate output of mixed light that meets the target white balance requirements, avoiding the chromaticity coupling error caused by traditional independent channel correction, and improving the control accuracy and response speed of the backlight white balance. Simultaneously, by combining a multi-temperature three-dimensional lookup table set for temperature adaptation control, it can effectively compensate for the drift caused by temperature changes to the photoelectric characteristics of the backlight module, ensuring that the backlight maintains a stable and consistent white balance output at different operating temperatures, significantly improving the accuracy and reliability of the displayed colors. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0021] Figure 1 A schematic flowchart of a backlight white balance control method provided in an embodiment of this application; Figure 2 A flowchart illustrating a method for constructing a three-dimensional lookup table provided in an embodiment of this application; Figure 3 A flowchart illustrating an optimal three-color drive current value acquisition method provided in this application embodiment; Figure 4 A flowchart illustrating another method for constructing a three-dimensional lookup table provided in an embodiment of this application; Figure 5 A flowchart illustrating the steps of a method for constructing a three-dimensional lookup table, as provided in an embodiment of this application. Figure 6 A schematic diagram of the process steps of a backlight white balance control method provided in an embodiment of this application; Figure 7 A schematic diagram of a backlight white balance control device provided in an embodiment of this application; Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0024] To address the problems in existing RGB backlight white balance control technologies, such as treating the RGB three channels as independent variables and failing to compensate for the nonlinear response of the three-color LEDs under different driving currents, insufficient calibration in the low current region leading to dark field color shift, and the inability of static calibration data to track the drift of LED photoelectric characteristics with temperature and usage time, resulting in deterioration of white balance accuracy, this application provides a backlight white balance control method, device, electronic device, and storage medium. It constructs a three-dimensional lookup table with target brightness and target chromaticity coordinates as input and RGB three-channel driving current values ​​as output through local high-precision measurement and optimization algorithms. This table fully depicts the three-dimensional mapping relationship of "current-brightness-chromaticity" and focuses on modeling the low-current nonlinear region. Introducing this photoelectric inverse model three-dimensional lookup table into the real-time rendering pipeline can accurately compensate for the nonlinear characteristics of the RGB backlight system, completely eliminate low-brightness color shift, ensure consistent white balance across the entire brightness range, and simultaneously address dynamic drift of photoelectric characteristics, maintaining long-term color accuracy and improving display quality.

[0025] Figure 1 This is a flowchart illustrating a backlight white balance control method provided in an embodiment of this application, as shown below. Figure 1 As shown, the method includes: S101. Construct a set of three-dimensional lookup tables with multiple temperatures, the set of three-dimensional lookup tables including multiple three-dimensional lookup tables with different preset temperatures.

[0026] In this embodiment, to address the temperature drift problem, at each preset temperature point, a high-precision spectrometer is used to collect the brightness and chromaticity response data of RGB LEDs across the entire current range. Combined with nonlinear interpolation and a temperature compensation model, a complete set of thermal three-dimensional lookup tables covering different preset temperatures is generated. Each table takes the target brightness L and chromaticity coordinates u' and v' as index inputs and outputs the corresponding optimal RGB driving current combination to construct three-dimensional lookup tables under different ambient temperatures, generating a temperature slice family. By creating a three-dimensional lookup table corresponding to each preset temperature, a multi-dimensional three-dimensional lookup table set containing multiple preset temperatures is constructed.

[0027] S102. When displaying an image on a backlight display device, the current operating temperature of the backlight module is detected, and the target light output characteristics of the current display screen are determined. The target light output characteristics include the target brightness value and the target chromaticity coordinates corresponding to the target white balance.

[0028] In this embodiment, when the backlight display device displays an image, the current operating temperature must first be determined. The thermistor value of the backlight module is collected in real time by the built-in temperature sensor, and the current operating temperature is calculated by combining it with the pre-stored temperature-voltage calibration curve. Simultaneously, the brightness and white point metadata in the image signal are analyzed, or the target brightness L and target chromaticity coordinates (u', v') of the current frame are dynamically generated according to the display mode and the user's set color temperature preference. The determined target light output characteristics will serve as the key input for subsequent table lookup and interpolation to ensure that the white balance response closely matches the actual operating conditions.

[0029] S103. Based on the current operating temperature, select a suitable three-dimensional lookup table from the multi-temperature three-dimensional lookup table set as the target three-dimensional lookup table.

[0030] In this embodiment, after determining the current operating temperature, the corresponding three-dimensional lookup table is further selected from the multi-temperature three-dimensional lookup table set based on the current operating temperature.

[0031] S104. Using the target brightness value and target chromaticity coordinates as input, query the target three-dimensional lookup table to obtain the target three-color driving current value that matches the target light output characteristics.

[0032] In this embodiment, a trilinear interpolation algorithm can be used in the query process to locate the eight nearest neighbors in the L-u'-v' space of the target three-dimensional lookup table, and then calculate and output the optimal RGB driving current I using a weighted average. R I G I B The interpolation weights are determined by the normalized distances of each dimension, ensuring that the output current is continuously differentiable and without abrupt changes, thus balancing response accuracy and real-time performance.

[0033] S105. Generate a driving signal based on the target three-color driving current value, and drive the backlight module to output mixed light that matches the target light output characteristics, so as to achieve backlight white balance control.

[0034] In this embodiment, after obtaining the target three-color driving current value, a matching driving signal is generated based on the current value, and then the driving signal is input to the backlight module. After receiving the driving signal, the backlight module converts the current signal into actual driving power through its internal driving circuit, and controls the red, green and blue LED light sources to emit light according to the target driving current value.

[0035] The light emitted by the three-color light source is mixed and homogenized by optical structures such as light guide plates and diffusers inside the backlight module, and finally outputs mixed light that meets the target brightness L and target chromaticity coordinates (u', v'). This enables real-time and precise white balance control of the backlight system, ensuring that the backlight output color remains stable and accurate under different temperature conditions and display requirements.

[0036] The backlight white balance control method provided in this application embodiment achieves accurate characterization of the photoelectric characteristics of RGB LEDs at different temperatures by constructing a set of multi-temperature three-dimensional lookup tables. Combined with real-time temperature detection and target light output feature analysis, it can dynamically select the appropriate three-dimensional lookup table and quickly obtain the target three-color driving current value through a trilinear interpolation algorithm, and finally generate a driving signal to control the backlight module to output matched mixed light. Furthermore, by completely modeling the three-dimensional mapping relationship of "current-brightness-chromaticity", it effectively compensates for the nonlinear response of the RGB backlight system, especially by focusing on optimizing the low current nonlinear region, thereby completely eliminating low brightness color shift and ensuring white balance consistency across the entire brightness range.

[0037] In an optional embodiment of the present invention, the process of constructing the multi-temperature three-dimensional lookup table set includes: Under temperature control, for any preset temperature, a three-dimensional lookup table is constructed with light output characteristics as input and three-color driving current values ​​that realize the light output characteristics as output. The light output characteristics include luminance values ​​and chromaticity coordinates. All three-dimensional lookup tables for preset temperatures are integrated to form a multi-temperature three-dimensional lookup table set.

[0038] In this embodiment, the RGB LED backlight module is first placed in an environmental chamber with precisely adjustable temperature. A series of preset temperature points covering its actual operating temperature range are set, for example, from -20℃ to 60℃, with each temperature point set every 5℃ or 10℃. At each preset temperature, the backlight module undergoes sufficient temperature stabilization treatment to ensure its photoelectric characteristics reach a stable state at that temperature. Then, for each temperature point, the driving current combination of the RGB three-color LEDs is systematically changed, for example, by scanning the current in steps (e.g., 5mA or 10mA) within their respective rated current ranges. For each set of driving current values, a high-precision luminance meter and colorimeter are used to collect the luminance value (e.g., nit value) and chromaticity coordinates of the output light from the backlight module in real time. The collected large amount of (luminance value, chromaticity coordinates) is used as input, and the corresponding (R driving current, G driving current, B driving current) is used as output. A three-dimensional lookup table for that temperature is constructed through data fitting and interpolation algorithms.

[0039] The 3D lookup table can quickly retrieve or calculate the required three-color drive current values ​​based on given target light output characteristics (brightness and chromaticity). After constructing the 3D lookup tables for all preset temperature points, these 3D lookup tables corresponding to different temperatures are integrated, stored, and managed according to temperature indexes, thus forming a complete set of multi-temperature 3D lookup tables. This provides a solid data foundation for subsequent dynamic temperature compensation and precise light output control.

[0040] Figure 2 This is a flowchart illustrating a method for constructing a three-dimensional lookup table according to an embodiment of this application. Figure 2 As shown, the construction of a three-dimensional lookup table that takes the target light output characteristics as input and the three-color driving current value that realizes the target light output characteristics as output includes: S201. Traverse the three-color driving current combination space of the backlight module, collect the actual output brightness and actual chromaticity coordinates of the backlight module at the preset temperature, and store the collected actual output brightness, actual chromaticity coordinates and corresponding driving current values ​​into the feature database.

[0041] In this embodiment, for the red (R), green (G), and blue (B) LED light sources of the backlight module, a large number of different current combinations are generated within their respective allowable drive current ranges, according to a certain step size or sampling strategy. For example, the R, G, and B drive currents can be divided into several discrete sampling points within their minimum to maximum operating current ranges, and then all possible current combinations can be obtained through permutation and combination. For each such current combination, the actual output brightness and actual chromaticity coordinates of the backlight module under that drive are measured.

[0042] Then, the measured actual output brightness value, actual chromaticity coordinate value, and corresponding R, G, and B drive current values ​​are accurately recorded as a complete set of sample data and stored in a pre-established feature database. This feature database serves as the raw data source for subsequently constructing a 3D lookup table. Through this comprehensive traversal and acquisition, it can be ensured that the subsequently constructed 3D lookup table can cover the possible operating states of the backlight module at a preset temperature, laying the foundation for achieving precise light output control.

[0043] S202. Define the target mesh in the standard color space and refine the brightness dimension of the low-brightness area.

[0044] In this embodiment, considering that the human eye is more sensitive to brightness changes in low-brightness areas, in order to optimize data storage and processing efficiency while ensuring control accuracy, an initial three-dimensional target mesh is first defined in the standard color space based on preset brightness and chromaticity ranges. The three dimensions of this target mesh correspond to brightness (L) and two chromaticity coordinates (e.g., u', v').

[0045] Then, for the brightness dimension, a smaller step size is used for grid division in the low brightness range, that is, a densification process is performed, which significantly increases the number of grid points in the low brightness area, thereby enabling more precise capture of color changes in the area and providing denser reference data points for subsequent accurate interpolation and white balance control.

[0046] S203. For each target light output feature point in the target grid, perform reverse solution based on the feature database to obtain the optimal three-color driving current value corresponding to each target light output feature point.

[0047] The feature database stores light output feature data corresponding to different combinations of three-color driving currents for the backlight module at a preset temperature.

[0048] In this embodiment, for each target light output feature point in the target grid (i.e., a point defined by a specific brightness L and chromaticity coordinates u' and v'), a reverse solving algorithm is used to search or calculate the three-color driving current combination that enables the backlight module to output the target light output feature point in the feature database.

[0049] Since the feature database covers possible operating states at a preset temperature and the target mesh is encrypted in the low-brightness region, the reverse solution process can accurately locate the optimal three-color driving current value that matches the target light output feature point, ensuring that each target point has a corresponding accurate driving parameter that can realize the light output feature.

[0050] S204. Generate a three-dimensional lookup table for the preset temperature based on the mapping relationship between each target light output feature point and the corresponding optimal three-color driving current value.

[0051] In this embodiment, the brightness L and chromaticity coordinates u' and v' of the target light output feature points are used as input dimensions, and the corresponding optimal three-color driving current values ​​are used as output data. By integrating and meshing all the target light output feature points and their matching optimal three-color driving current values, a three-dimensional lookup table that can directly reflect the mapping relationship between light output features and driving current is constructed.

[0052] The method for constructing a three-dimensional lookup table provided in this application constructs a feature database containing rich light output feature data by traversing and sampling the three-color driving current combination space of the backlight module at a preset temperature. It also densifies the brightness dimension of the target mesh for low-brightness areas sensitive to the human eye, and then matches the optimal driving current for each target light output feature point through inverse solving. The resulting three-dimensional lookup table can achieve accurate mapping from light output features to driving current. This not only ensures accurate reproduction of various target light output features of the backlight module at the preset temperature, but also significantly improves control accuracy, especially in low-brightness areas. Furthermore, the reasonable mesh division optimizes data storage and processing efficiency, providing a solid data foundation for real-time and efficient control of backlight white balance.

[0053] Figure 3 This is a flowchart illustrating an optimal three-color drive current value acquisition method provided in an embodiment of this application, as shown below. Figure 3 As shown, the inverse solution based on the feature database to obtain the optimal three-color driving current value corresponding to each target light output feature point includes: S301. Based on the target light output feature of the target light output feature point, determine in the feature database multiple sets of actual output brightness, actual chromaticity coordinates and corresponding initial values ​​of three-color driving current that match the target light output feature point.

[0054] In this embodiment, in order to achieve accurate matching of target light output feature points, actual data associated with target light output features (including target brightness and target chromaticity coordinates) are first screened from the feature database.

[0055] Specifically, the brightness value and chromaticity coordinates of the target light output feature points are used as search conditions. All records in the feature database that meet the preset similarity threshold for actual output brightness and actual chromaticity coordinates are searched. These records contain the corresponding initial values ​​of the red, green and blue driving currents, thus forming multiple sets of candidate driving current schemes. This provides a valuable initial data foundation for the subsequent optimal driving current solution, ensuring the relevance and efficiency of subsequent calculations.

[0056] S302. Obtain the pre-set comprehensive evaluation index of color difference and brightness deviation, and construct an optimization solution model with the minimum deviation of the characteristic parameters of the actual output brightness, actual chromaticity coordinates and target light output characteristic points as the optimization objective.

[0057] In this embodiment, the absolute difference between the target brightness and the actual output brightness, as well as the color difference between the target chromaticity coordinates and the actual chromaticity coordinates, are weighted and combined to form a single comprehensive evaluation function. The magnitude of this function directly reflects the overall deviation between the backlight output and the target light output feature points under the current driving current scheme. Then, using the initial values ​​of the three-color driving currents from multiple candidate driving current schemes as variables, minimizing the comprehensive evaluation function value is the core optimization objective. Simultaneously, combined with the hardware constraints of the backlight system, a complete optimization solution model is constructed.

[0058] S303. The optimization solution model is iteratively calculated using an optimization algorithm to obtain the three-color driving current value that makes the comprehensive evaluation index optimal, which is then used as the optimal three-color driving current value corresponding to the target light output feature point.

[0059] In this embodiment, a suitable optimization algorithm is selected to perform iterative optimization calculations on the constructed optimization solution model. During the iteration process, the algorithm continuously adjusts the values ​​of the three-color driving current. After each adjustment, the corresponding actual output brightness and chromaticity coordinates are calculated based on the current value and substituted into the comprehensive evaluation function to obtain the function value.

[0060] Then, by continuously comparing the function values ​​under different current combinations, the algorithm gradually searches in the direction that minimizes the function value. When the number of iterations reaches the preset upper limit, or when the change in the comprehensive evaluation function value is less than the set convergence threshold after multiple consecutive iterations, the iteration stops. The three-color driving current value obtained at this time is the result that makes the comprehensive evaluation index optimal, and it is determined as the optimal three-color driving current value corresponding to the target light output feature point.

[0061] The optimal three-color driving current value acquisition method provided in this application can efficiently and accurately determine the optimal three-color driving current value corresponding to each target light output feature point by accurately matching initial data from a feature database, constructing an optimization model that comprehensively considers color difference and brightness deviation, and iteratively optimizing using an optimization algorithm. This method fully utilizes the actual operating data accumulated in the feature database, ensuring the reliability and relevance of the initial data. Simultaneously, by setting comprehensive evaluation indicators, it achieves coordinated optimization of backlight output brightness and color, effectively improving the accuracy and stability of backlight white balance control.

[0062] For example, the process of constructing a multi-temperature three-dimensional lookup table set may include the following specific steps: Step 1: Encrypted Sampling and Feature Data Acquisition In a precisely temperature-controlled environment, the RGB backlight module under test is driven, and the driving current combination space of the R, G, and B channels is systematically traversed. It should be noted that in the "low current region" from near zero current to 10% of the rated current, a sampling density much higher than that in the medium and high current regions is used for scanning (for example, sampling every 0.5% current step in the low current region and every 2% current step in the medium and high current regions).

[0063] Each group (I) was measured simultaneously using a spectroradiometer. R ,I G ,I B Under current input, the actual luminous flux Y output by the backlight module meas and chromaticity coordinates (x meas ,y meas This results in a massive database of (I,Y,x,y) quadruple features.

[0064] Step 2: Inverse Model Solving and 3D LUT Filling: Define the luminance range to be covered in the target color space (e.g., CIE 1931 xyY). min Y max ] and color range.

[0065] For a target point P in this space t =(Y t ,x t ,y t ), search the feature database for the actual output light P meas =(Y m ,x m ,y m ) and target point P t The drive current combination with the smallest difference (I) Ropt ,I Gopt ,I Bopt This process is achieved by solving the following optimization problem:

[0066] Where, ΔE uv For the color difference in the CIE u', v' color space, w Y and w c These are the weighting coefficients. The optimal current combination is obtained through optimization algorithms such as the Levenberg-Marquardt method and then filled into the 3D LUT P. t The location corresponding to the coordinates.

[0067] It should be noted that to cope with temperature drift, the above process needs to be repeated at different ambient temperatures (such as 20°C, 35°C, 50°C) to generate a "3D LUT temperature slice family", that is, a set of multi-temperature three-dimensional lookup tables.

[0068] In an optional solution of the embodiment of the present invention, the method further includes: In the case that there is no three-dimensional lookup table in the set of multi-temperature three-dimensional lookup tables that adapts to the current working temperature, obtain the three-dimensional lookup tables corresponding to at least two adjacent preset temperatures corresponding to the current working temperature; perform interpolation processing on the three-dimensional lookup tables corresponding to the at least two adjacent preset temperatures to generate a three-dimensional lookup table that adapts to the current working temperature.

[0069] In this embodiment, when the current working temperature is between two adjacent preset temperatures (such as T1 and T2, and T1 < Tc urrent < T2), extract the three-dimensional lookup table data corresponding to T1 and T2. For each target point P in the target color space t , respectively obtain the corresponding optimal drive current combinations (I R1 , I G1 , I B1 ) and (I R2 , I G2 , I B2 ) from the three-dimensional lookup tables of T1 and T2. Then, perform weighted calculation according to the difference ratio between the current working temperature T current and T1, T2. For example, if the temperature interval is ΔT = T2 - T1 and the current temperature offset is ΔT current = T current - T1, then the interpolation weight coefficient α = ΔT current / ΔT, β = 1 - α. Finally, the drive current combination (I t , I Rcurrent , I Gcurrent , I Bcurrent ) corresponding to P at the current temperature can be calculated by the following formula.

[0070] I Rcurrent = α I R2 + β I R1 、I Gcurrent = α I G2 + β I G1 ; I Bcurrent = α I B2 + β I B1 ; The three-dimensional look-up table generation method provided by the embodiments of the present application can smoothly transition the driving parameters at different temperatures through interpolation, ensuring the stability and consistency of white balance during temperature changes of the backlight, and avoiding color deviation caused by temperature fluctuations.

[0071] Figure 4 As shown in the flowchart of another method for constructing a three-dimensional look-up table provided by the embodiments of the present application, Figure 4 as shown, the interpolation processing of the three-dimensional look-up tables corresponding to at least two adjacent preset temperatures to generate a three-dimensional look-up table adapted to the current working temperature includes: S401. Perform interpolation calculations in the three-dimensional look-up tables corresponding to at least two adjacent preset temperatures to obtain groups of three-color drive current values corresponding to each adjacent preset temperature.

[0072] In this embodiment, after obtaining the current working temperature, first determine between which two adjacent preset temperatures this current working temperature is located. For example, if the preset temperatures include T1 and T2 (T1 < current working temperature < T2), the corresponding three-dimensional look-up tables are LUT T1 and LUT T2 . For each combination of the same brightness level and gray scale value in LUT T1 and LUT T2 , the corresponding three-color drive current values (I R1 , I G1 , I B1 ) and (I R2 , I G2 , I B2 ) are calculated according to a preset interpolation algorithm (such as linear interpolation) to obtain a group of three-color drive current values at the current working temperature for this brightness level and gray scale value combination.

[0073] S402. Determine the interpolation weights of the groups of three-color drive current values corresponding to each adjacent preset temperature according to the temperature differences between the current working temperature and the at least two adjacent preset temperatures.

[0074] In this embodiment, assuming the current operating temperature is T, and two adjacent preset temperatures are T1 (lower temperature) and T2 (higher temperature), the temperature difference can be expressed as ΔT1 = T - T1 and ΔT2 = T2 - T. The interpolation weights are determined based on the ratio of the temperature difference to the total temperature range. For example, the weight of the three-color drive current value group corresponding to T1 can be set to ΔT2 / (T2 - T1), and the weight of the three-color drive current value group corresponding to T2 can be set to ΔT1 / (T2 - T1). The closer the current operating temperature is to a certain preset temperature, the greater the weight of the three-color drive current value group corresponding to that preset temperature in the interpolation calculation, thus making the generated three-color drive current value group adapted to the current operating temperature closer to the characteristics at that preset temperature.

[0075] S403. Based on the interpolation weight, perform weighted interpolation calculation on the three-color drive current value groups corresponding to the at least two adjacent preset temperatures to obtain a three-color drive current value group that is adapted to the current working temperature.

[0076] In this embodiment, the three-color drive current value group (R,G,B) obtained by weighted interpolation and adapted to the current operating temperature T ensures that the backlight maintains a good white balance effect at this temperature.

[0077] S404. Based on the mapping relationship between the target light output characteristics and the three-color drive current value group adapted to the current operating temperature, generate a three-dimensional lookup table adapted to the current operating temperature.

[0078] In this embodiment, a three-dimensional lookup table is constructed by using the three-color driving current value set (R, G, B) at the current operating temperature as input parameters and the target light output characteristics (such as brightness, color coordinates, etc.) as output results to establish a precise correspondence between current input and light output. This three-dimensional lookup table can efficiently convert the temperature-adapted three-color driving current value set into a control signal that meets the preset light output requirements, thereby ensuring that the backlight system stably outputs light that meets the target light output characteristics at the current operating temperature, and further ensuring the consistency and reliability of backlight white balance under different temperature environments.

[0079] The method for constructing a three-dimensional lookup table provided in this application constructs a three-dimensional lookup table by performing interpolation calculations between three-dimensional lookup tables of adjacent preset temperatures and determining the interpolation weights based on the temperature difference. This enables the generated three-dimensional lookup table to accurately match the characteristics of the backlight at the current temperature, effectively solving the problem of white balance shifting when the temperature changes in traditional fixed three-dimensional lookup tables. It ensures that the backlight system can output a stable three-color driving current that conforms to the target light output characteristics based on the three-dimensional lookup table under different temperature environments, thereby achieving temperature adaptability optimization of backlight white balance and improving the display quality and user experience of display devices under complex temperature conditions.

[0080] For example, multidimensional LUT query and interpolation includes the following steps: Step 1: Based on the current temperature Tcurrent fed back by the device's built-in temperature sensor, select two adjacent LUTs (e.g., LUTs) from the "3DLUT Temperature Slice Family". T1 and LUT T2 , where T1≤T current ≤T2).

[0081] Step 2: Using (Y) target ,x target ,y target ) are the inputs, respectively in the LUT T1 and LUT T2 Trilinear interpolation is performed to obtain two sets of drive current values ​​(I). R1 ,I G1 ,I B1 ) and (I R2 ,I G2 ,I B2 ).

[0082] Step 3: Based on T current Linear interpolation is performed between T1 and T2 to obtain the final temperature-compensated drive current command.

[0083] Figure 5 A flowchart illustrating the steps of a method for constructing a three-dimensional lookup table provided in this application embodiment is shown below. Figure 5 As shown, a complete set of multi-temperature three-dimensional lookup tables (3D LUTs) is constructed, and when the display device is working in real time, the table is dynamically looked up or interpolated according to the current temperature to achieve accurate white balance compensation under full brightness and full temperature environment. The whole process is mainly divided into two core links: offline data acquisition stage and online inverse model solving and LUT integration stage.

[0084] (I) The offline data acquisition phase mainly includes the following steps: Step 1: Environment Setup and Initialization: First, place the backlight module in a temperature-controlled environmental chamber (such as a high and low temperature test chamber) and set the initial constant temperature environment temperature to T. start The RGB backlight module is driven into its initial working state, ready for photoelectric characteristic scanning.

[0085] Step 2, Multi-temperature point scanning and measurement cycle: For the current temperature point T start Perform the following scanning and measurement procedures: Current scan setting: Sets the driving current combination of the RGB three-channel backlight LED chips (I R ,I G ,I BTo address the nonlinear characteristics of low-brightness regions, this embodiment employs a non-uniform sampling strategy.

[0086] Focus on sampling the low-current region: Define the area from near-zero current to a preset low percentage of the rated current (e.g., 10% of the rated current) as the low-current region. Within this region, use a denser current sampling interval to scan and capture the weak and highly nonlinear photoresponse characteristics of the LED under microcurrent.

[0087] Routine sampling in the medium-high current range: The area above the preset low proportion of rated current is defined as the medium-high current range, and a sparser sampling interval is used in this range to complete the full range scan.

[0088] Synchronous Measurement and Data Recording: While performing current scanning, a spectroradiometer is used to simultaneously measure the actual output optical parameters of the backlight module, including the actual output luminous flux Y. meas and actual chromaticity coordinates (x meas ,y meas ).

[0089] Loop judgment: Determine whether the low current range scan is complete; if not, continue to adjust the drive current combination for the next round of scanning; if complete, organize and store all the drive current combinations, corresponding luminous flux Y and chromaticity coordinates (x,y) data collected in this round into the feature database.

[0090] Step 3: Temperature Traversal: Determine if all N preset temperature points have been tested. If not, adjust the temperature control chamber to the next temperature point T. next Repeat the scanning and measurement cycle in step two until all photoelectric feature data at all temperature points have been collected. If complete, proceed to the inverse model solution stage.

[0091] (II) Online Inverse Model Solving and LUT Integration Stage: This stage aims to establish a global inverse mapping relationship between luminance, chromaticity, and current using the collected data. It mainly includes the following steps: Step 1: Target Mesh Definition and Low-Brightness Refinement: In the CIE xyY color space (or standard colorimetric color space), a target mesh is defined to characterize the light output features of the target. To ensure color accuracy of dark details, this embodiment refines the Y-axis of the brightness dimension in low-brightness regions (i.e., the Y-value corresponding to near-zero brightness to low proportion of rated brightness), increasing the mesh density in this region and focusing on modeling the nonlinearity of the photoelectric response under low brightness.

[0092] Step 2, Reverse Solution: Optimal Current Combination for Each Target Light Output Feature Point P in the Target Mesh t(Including target brightness value and target chromaticity coordinates), the solution is performed in reverse based on the aforementioned feature database. Specifically, with the target light output characteristics as constraints, similar photoelectric feature data are retrieved from the database, and a model is constructed with the minimum color difference and brightness deviation as the optimization objective. Optimization algorithms such as the Levenberg-Marquardt method are used for iterative calculation to obtain the optimal combination of three-color driving currents that achieves the best comprehensive evaluation index.

[0093] Step 3: Single-temperature LUT generation: Based on the target light output feature points P t The mapping relationship between the corresponding optimal three-color drive current combination is used to generate a three-dimensional lookup table (3D LUT) data file at the current temperature point.

[0094] Step 4: Integration of Multi-Temperature LUT Slice Families: Determine whether the data for all N temperature points has been processed. If not, load the feature data for the next temperature point and repeat steps 2 to 3 to generate the 3D LUT corresponding to that temperature point. If the data has been processed, integrate the 3D LUT data files corresponding to all preset temperatures to form a complete "3DLUT temperature slice family," which is a set of multi-temperature 3D lookup tables. This completes the offline construction process.

[0095] Furthermore, when displaying images on a backlit display device, the control method of the present invention also includes a real-time white balance control application, specifically comprising the following steps: Step 1: Temperature Detection and Feature Determination: Real-time detection of the current operating temperature of the backlight module to determine the target light output characteristics (target brightness value and target white balance chromaticity coordinates) of the current display screen.

[0096] Step 2, Temperature Adaptation: Based on the current operating temperature, select a suitable 3DLUT from the multi-temperature 3D lookup table set. If no directly matching temperature slice exists, select slices from at least two adjacent temperatures for interpolation processing to generate a temporary LUT adapted to the current temperature.

[0097] Step 3, Precise Driving: Using the target brightness and chromaticity coordinates as input, query the matching LUT to obtain the target three-color driving current value, and generate a driving signal based on the value to drive the backlight module, outputting mixed light that matches the target characteristics, and achieving full brightness and high color accuracy white balance control.

[0098] The embodiments of this application construct a three-dimensional lookup table through the above steps, which fully depicts the three-dimensional coupled nonlinear relationship of "current-brightness-chromaticity," rather than the traditional independent channel correction, thus completely offsetting the nonlinear response caused by material differences in the three-color LEDs. Furthermore, through dual-encrypted sampling and modeling of the low-current and low-brightness regions, the color accuracy control precision in dark scenes is significantly improved, effectively avoiding low-brightness color shift phenomena such as "green fog" and "purple fringing." By establishing a multi-temperature slice family, the display device can cope with the dynamic drift of LED photoelectric characteristics as junction temperature increases and usage time accumulates, ensuring the stability and consistency of white balance accuracy under different ambient temperatures and long-term use.

[0099] In one optional embodiment of the present invention, during the process of acquiring the actual output brightness and actual chromaticity coordinates of the backlight module, the current sampling interval used in the low current range is smaller than the current sampling interval in the medium-high current range. The low current range is the current range from near zero current to a preset low-proportion rated current, and the medium-high current range is the current range above the preset low-proportion rated current.

[0100] In this embodiment, because the brightness and chromaticity of the backlight module often exhibit more complex nonlinear variation characteristics in the low-current region, even small current changes can lead to significant fluctuations in output parameters. By using a smaller current sampling interval in the low-current range, the brightness and chromaticity data of the backlight module in this range can be acquired more densely, capturing these subtle changes more accurately and providing sufficient data support for the subsequent construction of a high-precision three-dimensional lookup table (3DLUT). Thus, in actual control, even in low-brightness output scenarios, precise white balance control can be achieved. For the medium-to-high current range, the output characteristics of the backlight module are relatively stable, and a larger sampling interval is sufficient to reflect its changing trend, while also avoiding unnecessary data redundancy. This improves the efficiency of data acquisition and processing while ensuring control accuracy.

[0101] Figure 6 A schematic diagram of the process steps of a backlight white balance control method provided in this application embodiment is shown below. Figure 6 As shown, the display device in this embodiment uses a single frame of video signal as the processing unit. Through a closed-loop logic of "target resolution - temperature adaptation - LUT query - driver execution", it dynamically outputs mixed light that matches the target light output characteristics, ensuring the color accuracy and white balance consistency of each frame. Specifically, it includes the following five stages: (I) Frame processing initialization and target parsing, mainly including the following steps: Step 1, Frame Processing Startup: Begin a new frame backlight control process by receiving input video signals from the display system.

[0102] Step 2, Image Quality Analysis: The image quality engine is called to analyze the input video image, extract the global brightness distribution, regional brightness requirements and color features of the image, and provide basic data for backlight control.

[0103] Step 3: Calculation of target light output characteristics: Based on the image analysis results, the target brightness value Y of each backlight zone is calculated. target It adapts to the local dimming strategy to achieve precise matching of screen brightness; Based on the color management requirements of the display device, determine the target white balance chromaticity coordinates x for the current frame. target ,y target It serves as the color accuracy reference for backlight mixing light.

[0104] (II) Temperature acquisition and LUT adaptation selection mainly include the following steps: Step 1: Obtain the current operating temperature: Read the real-time data from the temperature sensor built into the backlight module to obtain the current operating temperature T. current It is used to dynamically compensate for temperature drift in the photoelectric properties of LEDs.

[0105] Step 2: Temperature Range Determination and LUT Selection: Based on the current operating temperature T current Based on the distribution relationship of preset temperature points in the offline-built multi-temperature 3D LUT set, the following branch logic is executed: For adaptation in low-temperature ranges: If T current ≤T1 (T1 is the preset lowest temperature point), directly select the lowest temperature 3D LUT slice from the set (LUT). T1 ); For high-temperature range adaptation: If T current ≥T N (T) N (To preset the highest temperature point), directly select the highest temperature 3D LUT slice from the set (LUT). TN ); For adaptation to the intermediate temperature range: if T n ≤T current ≤Tn+1(T n T n+1 (For adjacent preset temperature points), select the 3D LUT slices corresponding to two adjacent temperature points (LUT). Tn With LUT Tn+1 Then, proceed to the double LUT interpolation process.

[0106] (III) Obtaining the target drive current through LUT query / interpolation mainly includes the following steps: Step 1: Single LUT query (boundary temperature scenario): When T current When within the boundary temperature range, the target brightness Y of the current frame is used.target and target chromaticity coordinates xt arget ,y target Using the input vector, query the selected single-temperature 3D LUT to directly obtain the target three-color driving current value I that precisely matches the target light output characteristics. R ,I G ,I B .

[0107] Step 2: Double LUT interpolation (intermediate temperature scenario): When T current When the temperature is in the intermediate range, perform the following interpolation operation: Using the target light output characteristics as input, query the 3D LUT of two adjacent temperature points to obtain two sets of corresponding three-color driving current values; Based on the current operating temperature T current With adjacent temperature point T n T n+1 The difference is used to calculate the linear interpolation weights of the two sets of drive current values; The two sets of drive current values ​​are weighted and calculated based on interpolation weights to obtain the target three-color drive current value I that is adapted to the current operating temperature. R ,I G ,I B .

[0108] (iv) Drive execution and backlight output, mainly including the following steps: Step 1: Drive Signal Conversion: The driver IC receives the target three-color drive current value command and converts it into a PWM pulse signal or analog voltage signal that can directly drive the LED. If a PWM signal is used, the actual output amplitude of the three drive currents can be precisely controlled by adjusting the pulse duty cycle. If an analog voltage signal is used, the voltage value is directly mapped to the corresponding driving current, ensuring the accuracy and stability of the current output.

[0109] Step 2, RGB Mini LED Backlight Driver: The driver IC outputs the corresponding driving current to the R, G, and B LED chips of the RGB Mini LED backlight module, controlling each chip to emit light according to the target brightness and color requirements.

[0110] Step 3, Precise Mixed Light Output: The monochromatic light emitted by the three-color LEDs is mixed according to the target ratio to output mixed light that perfectly matches the target light output characteristics (target brightness, target white balance chromaticity coordinates) of the current frame, thus completing the backlight white balance control for this frame.

[0111] (v) Closed-loop process After the backlight control of this frame ends, wait for the next frame of video signal input, and repeat the above process to achieve continuous and dynamic backlight white balance control.

[0112] This application's embodiments utilize a multi-temperature LUT slicing and interpolation mechanism to track the changes in LED photoelectric characteristics with temperature in real time, avoiding white balance degradation caused by static calibration data failure and ensuring color accuracy consistency under different ambient temperatures. Based on an offline-built 3D LUT inverse model, it accurately compensates for nonlinear characteristics in low-brightness areas, completely eliminating dark-field color shifts such as "green fog" and "purple fringing," achieving stable white balance output across the entire brightness range from maximum brightness to near black, and adapting to high refresh rate display requirements. It is also compatible with PWM / analog drive modes and suitable for various RGB Mini LED display devices.

[0113] Figure 7 This is a schematic diagram of the structure of a backlight white balance control device provided in an embodiment of this application, as shown below. Figure 7 As shown, the device specifically includes: The construction module 701 is used to construct a set of three-dimensional lookup tables with multiple temperatures, the set of three-dimensional lookup tables including multiple three-dimensional lookup tables with different preset temperatures; The detection module 702 is used to detect the current operating temperature of the backlight module and determine the target light output characteristics of the current display screen when the backlight display device is displaying an image. The target light output characteristics include the target brightness value and the target chromaticity coordinates corresponding to the target white balance. The selection module 703 is used to select an appropriate three-dimensional lookup table from the multi-temperature three-dimensional lookup table set according to the current operating temperature, and use it as the target three-dimensional lookup table. Matching module 704 is used to query the target three-dimensional lookup table with the target brightness value and target chromaticity coordinates as input to obtain the target three-color driving current value that matches the target light output characteristics; The driving module 705 is used to generate a driving signal based on the target three-color driving current value, and drive the backlight module to output mixed light that matches the target light output characteristics, so as to realize backlight white balance control.

[0114] In one possible implementation, the construction module 701 is further configured to construct a three-dimensional lookup table for any preset temperature under a temperature-controlled environment, with light output characteristics as input and three-color driving current values ​​that realize the light output characteristics as output, wherein the light output characteristics include luminance values ​​and chromaticity coordinates; and integrate all the three-dimensional lookup tables for preset temperatures to form a multi-temperature three-dimensional lookup table set.

[0115] In one possible implementation, the construction module 701 is further configured to traverse the three-color driving current combination space of the backlight module, collect the actual output brightness and actual chromaticity coordinates of the backlight module at the preset temperature, and store the collected actual output brightness, actual chromaticity coordinates and corresponding driving current values ​​into a feature database; define a target grid in a standard color space, and encrypt the brightness dimension of the low brightness region; for each target light output feature point in the target grid, perform inverse solving based on the feature database to obtain the optimal three-color driving current value corresponding to each target light output feature point; and generate a three-dimensional lookup table for the preset temperature according to the mapping relationship between each target light output feature point and the corresponding optimal three-color driving current value.

[0116] In one possible implementation, the construction module 701 is further configured to determine, based on the target light output characteristics of the target light output feature point, multiple sets of actual output brightness, actual chromaticity coordinates, and corresponding initial values ​​of the three-color driving current that match the target light output feature point in the feature database; obtain a pre-set comprehensive evaluation index of color difference and brightness deviation; construct an optimization solution model with the minimum deviation between the actual output brightness, actual chromaticity coordinates, and the feature parameters of the target light output feature point as the optimization objective; and use an optimization algorithm to iteratively calculate the optimization solution model to obtain the three-color driving current value that makes the comprehensive evaluation index optimal, which is then used as the optimal three-color driving current value corresponding to the target light output feature point.

[0117] In one possible implementation, the construction module 701 is further configured to, when there is no three-dimensional lookup table adapted to the current operating temperature in the multi-temperature three-dimensional lookup table set, obtain at least two three-dimensional lookup tables corresponding to the current operating temperature; and perform interpolation processing on the at least two three-dimensional lookup tables corresponding to the current operating temperature to generate a three-dimensional lookup table adapted to the current operating temperature.

[0118] In one possible implementation, the construction module 701 is further configured to perform interpolation calculations in the three-dimensional lookup tables corresponding to the at least two adjacent preset temperatures to obtain a set of three-color driving current values ​​corresponding to each adjacent preset temperature; determine the interpolation weight of the set of three-color driving current values ​​corresponding to each adjacent preset temperature based on the temperature difference between the current operating temperature and the at least two adjacent preset temperatures; perform weighted interpolation calculations on the set of three-color driving current values ​​corresponding to the at least two adjacent preset temperatures based on the interpolation weights to obtain a set of three-color driving current values ​​adapted to the current operating temperature; and generate a three-dimensional lookup table adapted to the current operating temperature based on the mapping relationship between the target light output characteristics and the set of three-color driving current values ​​adapted to the current operating temperature.

[0119] In one possible implementation, the construction module 701 is further configured to, during the process of acquiring the actual output brightness and actual chromaticity coordinates of the backlight module, use a current sampling interval for the low current range that is smaller than the current sampling interval for the medium-high current range. The low current range is the current range from near zero current to a preset low-proportion rated current, and the medium-high current range is the current range above the preset low-proportion rated current.

[0120] The backlight white balance device provided in this embodiment can be as follows: Figure 7 The backlight white balance device shown can perform the following functions: Figure 1-6 All steps of backlight white balance, thereby achieving Figure 1-6 The backlight white balance technical effect shown is illustrated in the image. Please refer to [link / reference]. Figure 1-6 The relevant descriptions are presented concisely and will not be elaborated upon here.

[0121] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0122] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application, such as... Figure 8 As shown, this application embodiment provides an electronic device, including a processor 801, a communication interface 802, a memory 803, and a communication bus 804. The processor 801, communication interface 802, and memory 803 communicate with each other via the communication bus 804. The memory 803 stores computer programs. When the processor 801 executes the program stored in the memory 803, it implements the backlight white balance step provided in any of the aforementioned method embodiments. A multi-temperature three-dimensional lookup table set is constructed, comprising multiple three-dimensional lookup tables for different preset temperatures. When the backlight display device displays an image, the current operating temperature of the backlight module is detected, and the target light output characteristics of the current display screen are determined. These target light output characteristics include a target brightness value and target chromaticity coordinates corresponding to the target white balance. Based on the current operating temperature, a suitable three-dimensional lookup table is selected from the multi-temperature three-dimensional lookup table set as the target three-dimensional lookup table. Using the target brightness value and target chromaticity coordinates as input, the target three-dimensional lookup table is queried to obtain a target three-color driving current value matching the target light output characteristics. A driving signal is generated based on the target three-color driving current value to drive the backlight module to output mixed light matching the target light output characteristics, thereby achieving backlight white balance control.

[0123] In one possible implementation, under a temperature-controlled environment, for any preset temperature, a three-dimensional lookup table is constructed with light output characteristics as input and three-color driving current values ​​that realize the light output characteristics as output. The light output characteristics include luminance values ​​and chromaticity coordinates. All three-dimensional lookup tables for preset temperatures are integrated to form a multi-temperature three-dimensional lookup table set.

[0124] In one possible implementation, the three-color driving current combination space of the backlight module is traversed, and the actual output brightness and actual chromaticity coordinates of the backlight module at the preset temperature are collected. The collected actual output brightness, actual chromaticity coordinates and corresponding driving current values ​​are stored in a feature database. A target grid is defined in a standard color space, and the brightness dimension of the low-brightness region is encrypted. For each target light output feature point in the target grid, the optimal three-color driving current value corresponding to each target light output feature point is obtained by inverse solving based on the feature database. According to the mapping relationship between each target light output feature point and the corresponding optimal three-color driving current value, a three-dimensional lookup table for the preset temperature is generated.

[0125] In one possible implementation, based on the target light output characteristics of the target light output feature point, multiple sets of actual output brightness, actual chromaticity coordinates, and corresponding initial values ​​of the three-color driving current are determined in the feature database to match the target light output feature point; a pre-set comprehensive evaluation index of color difference and brightness deviation is obtained, and an optimization solution model is constructed with the minimum deviation between the actual output brightness, actual chromaticity coordinates, and the feature parameters of the target light output feature point as the optimization objective; the optimization solution model is iteratively calculated using an optimization algorithm to obtain the three-color driving current value that makes the comprehensive evaluation index optimal, which is then used as the optimal three-color driving current value corresponding to the target light output feature point.

[0126] In one possible implementation, if no three-dimensional lookup table adapted to the current operating temperature exists in the set of multi-temperature three-dimensional lookup tables, at least two three-dimensional lookup tables corresponding to the current operating temperature are obtained; interpolation processing is performed on the three-dimensional lookup tables corresponding to the at least two adjacent preset temperatures to generate a three-dimensional lookup table adapted to the current operating temperature.

[0127] In one possible implementation, interpolation calculations are performed on the three-dimensional lookup tables corresponding to at least two adjacent preset temperatures to obtain a set of three-color driving current values ​​corresponding to each adjacent preset temperature; based on the temperature difference between the current operating temperature and the at least two adjacent preset temperatures, the interpolation weights of the three-color driving current value sets corresponding to each adjacent preset temperature are determined; based on the interpolation weights, weighted interpolation calculations are performed on the three-color driving current value sets corresponding to the at least two adjacent preset temperatures to obtain a set of three-color driving current values ​​adapted to the current operating temperature; and based on the mapping relationship between the target light output characteristics and the three-color driving current value sets adapted to the current operating temperature, a three-dimensional lookup table adapted to the current operating temperature is generated.

[0128] In one possible implementation, during the process of acquiring the actual output brightness and actual chromaticity coordinates of the backlight module, the current sampling interval used in the low current range is smaller than the current sampling interval in the medium-high current range. The low current range is the current range from near zero current to a preset low-proportion rated current, and the medium-high current range is the current range above the preset low-proportion rated current.

[0129] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, it can be implemented using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0130] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0131] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A backlight white balance control method, characterized in that, The method includes: Construct a set of three-dimensional lookup tables for multiple temperatures, the set of three-dimensional lookup tables for multiple different preset temperatures; When displaying images in a backlit display device, the current operating temperature of the backlight module is detected, and the target light output characteristics of the current display screen are determined. The target light output characteristics include the target brightness value and the target chromaticity coordinates corresponding to the target white balance. Based on the current operating temperature, a suitable three-dimensional lookup table is selected from the set of multi-temperature three-dimensional lookup tables as the target three-dimensional lookup table; Using the target brightness value and target chromaticity coordinates as input, the target three-dimensional lookup table is queried to obtain the target three-color driving current value that matches the target light output characteristics; A driving signal is generated based on the target three-color driving current value to drive the backlight module to output mixed light that matches the target light output characteristics, so as to achieve backlight white balance control.

2. The method according to claim 1, characterized in that, The process of constructing the multi-temperature three-dimensional lookup table set includes: Under temperature control, for any preset temperature, a three-dimensional lookup table is constructed with light output characteristics as input and three-color driving current values ​​that realize the light output characteristics as output. The light output characteristics include luminance values ​​and chromaticity coordinates. Integrate all preset temperature 3D lookup tables to form a multi-temperature 3D lookup table set.

3. The method according to claim 2, characterized in that, The construction of a three-dimensional lookup table, which takes the target light output characteristics as input and the three-color driving current value that achieves the target light output characteristics as output, includes: Traverse the three-color driving current combination space of the backlight module, collect the actual output brightness and actual chromaticity coordinates of the backlight module at the preset temperature, and store the collected actual output brightness, actual chromaticity coordinates and corresponding driving current values ​​into the feature database. Define the target mesh in the standard color space and refine the brightness dimension of the low-brightness areas; For each target light output feature point in the target grid, the optimal three-color driving current value corresponding to each target light output feature point is obtained by inverse solution based on the feature database. Based on the mapping relationship between each target light output feature point and the corresponding optimal three-color driving current value, a three-dimensional lookup table for the preset temperature is generated.

4. The method according to claim 3, characterized in that, The reverse solution based on the feature database to obtain the optimal three-color driving current value corresponding to each target light output feature point includes: Based on the target light output feature of the target light output feature point, multiple sets of actual output brightness, actual chromaticity coordinates and corresponding initial values ​​of three-color driving current are determined in the feature database to match the target light output feature point. Obtain the pre-set comprehensive evaluation index of color difference and brightness deviation, and construct an optimization solution model with the minimum deviation of the feature parameters of the actual output brightness, actual chromaticity coordinates and target light output feature points as the optimization objective; An optimization algorithm is used to iteratively calculate the optimization solution model to obtain the three-color driving current value that makes the comprehensive evaluation index optimal, which is then used as the optimal three-color driving current value corresponding to the target light output feature point.

5. The method according to claim 1, characterized in that, The method further includes: If no three-dimensional lookup table adapted to the current working temperature is found in the set of multi-temperature three-dimensional lookup tables, obtain at least two three-dimensional lookup tables corresponding to the current working temperature and adjacent preset temperatures. Interpolation processing is performed on the three-dimensional lookup tables corresponding to at least two adjacent preset temperatures to generate a three-dimensional lookup table adapted to the current working temperature.

6. The method according to claim 5, characterized in that, The step of interpolating the three-dimensional lookup tables corresponding to the at least two adjacent preset temperatures to generate a three-dimensional lookup table adapted to the current operating temperature includes: Interpolation calculations are performed in the three-dimensional lookup table corresponding to at least two adjacent preset temperatures to obtain a set of three-color drive current values ​​corresponding to each adjacent preset temperature. Based on the temperature difference between the current operating temperature and the at least two adjacent preset temperatures, determine the interpolation weight of the three-color drive current value group corresponding to each adjacent preset temperature. Based on the interpolation weight, a weighted interpolation calculation is performed on the three-color drive current value group corresponding to the at least two adjacent preset temperatures to obtain a three-color drive current value group that is adapted to the current working temperature. Based on the mapping relationship between the target light output characteristics and the three-color drive current value group adapted to the current operating temperature, a three-dimensional lookup table adapted to the current operating temperature is generated.

7. The method according to claim 4, characterized in that, In the process of collecting the actual output brightness and actual chromaticity coordinates of the backlight module, the current sampling interval used in the low current range is smaller than the current sampling interval in the medium and high current range. The low current range is the current range from near zero current to a preset low proportion of rated current, and the medium and high current range is the current range above the preset low proportion of rated current.

8. A backlight white balance control device, characterized in that, The device includes: A construction module is used to construct a set of multi-temperature three-dimensional lookup tables, which includes multiple three-dimensional lookup tables with different preset temperatures. The detection module is used to detect the current operating temperature of the backlight module when the backlight display device is displaying an image, and to determine the target light output characteristics of the current display screen. The target light output characteristics include the target brightness value and the target chromaticity coordinates corresponding to the target white balance. The selection module is used to select a suitable three-dimensional lookup table from the set of multi-temperature three-dimensional lookup tables based on the current operating temperature, and use it as the target three-dimensional lookup table. The matching module is used to query the target three-dimensional lookup table with the target brightness value and target chromaticity coordinates as input to obtain the target three-color driving current value that matches the target light output characteristics; The driving module is used to generate a driving signal based on the target three-color driving current value, and drive the backlight module to output mixed light that matches the target light output characteristics, so as to realize backlight white balance control.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the backlight white balance control method according to any one of claims 1 to 7.

10. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the backlight white balance control method according to any one of claims 1 to 7.

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