A method and system for color consistency calibration of a miniature LED display panel

Abstract

The application provides a micro Mini LED display panel color consistency calibration method and system, collects junction temperature data and current density data of the display panel, and then determines the electro-thermal coupling state of the display panel; a state space model is constructed based on the electro-thermal coupling state, and then the color quality coordinate offset of each pixel of the display panel under the coupling effect of the current junction temperature and current density is predicted to obtain the drift prediction value corresponding to the color quality of each pixel; taking the DCI-P3 color gamut coverage rate as the optimization target, the dynamic compensation coefficient of the red-green-blue ratio of each pixel under each gray scale is determined according to all the drift prediction values, and then a compensation coefficient matrix is constructed; based on the compensation coefficient matrix, the driving pulse width modulation signal is adjusted pixel by pixel, the calibrated driving signal is generated and output to the display panel driving circuit. Based on the above scheme, pixel-level dynamic color calibration based on real-time sensing of the electro-thermal coupling state can be realized to improve the color consistency under all working conditions.

Description

Technical Field

[0001] This application relates to the field of color calibration and optimization technology, and more specifically, to a method and system for color consistency calibration of a miniature LED display panel. Background Technology

[0002] As Mini LED display technology continues to evolve towards higher pixel density, higher brightness, and wider color gamut, its applications in professional film and television displays, high-end consumer electronics, and precision commercial displays are becoming increasingly widespread. Color consistency is a core indicator for evaluating the image quality performance of Mini LED display panels. Due to the limitations of the photoelectric characteristics of LED devices, the chromaticity coordinates of pixel emission will shift with changes in driving current density and chip junction temperature. Furthermore, the electrothermal coupling effect between miniaturized pixels will further exacerbate color differences. Therefore, efficient and accurate color calibration technology is a crucial foundation for ensuring display image quality.

[0003] In existing technologies, color calibration is mostly performed using static factory calibration. This typically generates uniform compensation parameters globally or regionally based on test data under fixed operating conditions. Some solutions only perform coarse color correction through single temperature monitoring, failing to establish accurate color drift prediction models for the pixel-level junction temperature and current density coupling effects. These solutions cannot adapt to the real-time changes in drive load and temperature distribution during display panel operation, easily leading to a continuous increase in color deviation between pixels under different gray levels and operating conditions. This makes it difficult to stably maintain the DCI-P3 wide color gamut coverage. Furthermore, the granularity and precision of dynamic compensation are insufficient, failing to balance color gamut retention and overall pixel color uniformity. Therefore, how to achieve pixel-level dynamic color calibration based on real-time sensing of electrothermal coupling states to improve color consistency across all operating conditions has become a challenge for the industry. Summary of the Invention

[0004] This application provides a method and system for color consistency calibration of a miniature LED display panel, which can realize pixel-level dynamic color calibration based on real-time sensing of electrothermal coupling state to improve color consistency under all operating conditions.

[0005] In a first aspect, this application provides a method for color consistency calibration of a miniature LED display panel, comprising the following steps: Synchronously collect junction temperature data and current density data of each pixel area of ​​the mini LED display panel under the current driving conditions, and then determine the electrothermal coupling state of the display panel based on the junction temperature data and the current density data. Based on the electrothermal coupling state, a state space model is constructed, and then the chromaticity coordinate offset of each pixel on the display panel under the coupling effect of the current junction temperature and current density is predicted through the state space model to obtain the drift prediction value of the chromaticity of each pixel. With DCI-P3 color gamut coverage as the optimization target, the dynamic compensation coefficient of the red, green and blue ratio of each pixel in the display panel at each gray level is determined based on all drift prediction values, and then a dynamic color gamut compensation coefficient matrix is ​​constructed based on all dynamic compensation coefficients. The driving pulse width modulation signal is adjusted pixel by pixel based on the compensation coefficient matrix to generate a calibrated driving signal, which is then output to the display panel driving circuit to complete color consistency calibration.

[0006] In some embodiments, determining the electrothermal coupling state of the display panel based on the junction temperature data and the current density data specifically includes: Spatial registration is performed on the junction temperature data and the current density data to obtain registered junction temperature data and current density data; Vector fusion is performed based on the registered junction temperature data and current density data to construct the electrothermal coupling state vector of each pixel of the display panel; The electrothermal coupling state of the display panel is determined based on the electrothermal coupling state vectors of all pixels.

[0007] In some embodiments, a state-space model is constructed based on the electrothermal coupling state, and then the chromaticity coordinate offset of each pixel on the display panel under the current junction temperature and current density coupling is predicted using the state-space model to obtain the chromaticity drift prediction value for each pixel. Specifically, this includes: Construct a state-space model of electrothermal coupling based on the aforementioned electrothermal coupling state; For each pixel of the display panel, the junction temperature and current density of the pixel region are nonlinearly mapped through the state space model to obtain the linear offset of the chromaticity coordinates of the pixel region under the temperature effect and the nonlinear offset under the current density effect. The linear offset and the nonlinear offset are superimposed to obtain the predicted offset value of the chromaticity coordinate of the pixel region under the coupling effect of the current junction temperature and current density. The pixel chromaticity drift prediction value is determined based on the reference chromaticity coordinates of the pixel region under standard reference conditions and the offset prediction value, thereby obtaining the chromaticity drift prediction value for each pixel.

[0008] In some embodiments, with DCI-P3 color gamut coverage as the optimization target, determining the dynamic compensation coefficient for the red-green-blue ratio of each pixel in the display panel at each grayscale based on all drift prediction values ​​specifically includes: For each pixel of the display panel, the red, green and blue ratio adjustment amount of the pixel at each gray level is determined based on the pixel's drift prediction value; With DCI-P3 color gamut coverage as the optimization target, target optimization is performed based on the red-green-blue ratio adjustment amount to obtain the red-green-blue ratio of the pixel to achieve the DCI-P3 color gamut coverage optimization target at each gray level. Based on the stated red-green-blue ratio and the standard red-green-blue ratio, the dynamic compensation coefficient of the red-green-blue ratio of the pixel at each gray level is determined, thereby obtaining the dynamic compensation coefficient of the red-green-blue ratio of each pixel on the display panel at each gray level.

[0009] In some embodiments, constructing a compensation coefficient matrix for the dynamic color gamut based on all dynamic compensation coefficients specifically includes: All dynamic compensation coefficients are arranged in the same spatial arrangement as the pixel array of the display panel to obtain the initial coefficient matrix of the dynamic color gamut; Gray-level smoothing is performed on the dynamic compensation coefficients of each pixel in the initial compensation coefficient matrix to obtain the intermediate coefficient matrix of the dynamic color gamut. Spatial low-pass filtering is performed on the dynamic compensation coefficients of each pixel in the intermediate coefficient matrix to obtain the dynamic color gamut compensation coefficient matrix.

[0010] In some embodiments, adjusting the driving pulse width modulation signal pixel-by-pixel based on the compensation coefficient matrix to generate a calibrated driving signal specifically includes: The compensation coefficient matrix is ​​decomposed according to the red, green and blue sub-pixel channels of the pixels to obtain the red sub-pixel compensation coefficient, green sub-pixel compensation coefficient and blue sub-pixel compensation coefficient of each pixel; For each pixel of the display panel, the duty cycle adjustment of the driving pulse width modulation signal of each sub-pixel in the pixel area is calculated according to the red sub-pixel compensation coefficient, green sub-pixel compensation coefficient and blue sub-pixel compensation coefficient of the pixel. Based on all duty cycle adjustments, the calibrated drive signal of each pixel is generated, thereby obtaining the calibrated drive signal of each pixel on the display panel. The calibrated drive signals of all pixels are synthesized according to the pixel spatial arrangement of the display panel to generate the calibrated drive signal.

[0011] In some embodiments, outputting the driving signal to the display panel driving circuit to complete color consistency calibration specifically includes: The driving signal is output to each pixel electrode in a line scanning manner through the display panel driving circuit; The micro LED chips on each pixel are driven to emit light according to the corrected conduction time ratio in the driving signal, thus completing the full-screen color consistency calibration.

[0012] Secondly, this application provides a color consistency calibration system for a miniature LED display panel, used to perform a color consistency calibration method for a miniature LED display panel, including: The acquisition module is used to simultaneously acquire junction temperature data and current density data of each pixel area of ​​the mini LED display panel under the current driving conditions, and then determine the electrothermal coupling state of the display panel based on the junction temperature data and the current density data. The processing module is used to construct a state space model based on the electrothermal coupling state, and then use the state space model to predict the chromaticity coordinate offset of each pixel of the display panel under the current junction temperature and current density coupling, so as to obtain the drift prediction value of the chromaticity of each pixel. The processing module is also used to determine the dynamic compensation coefficient of the red, green and blue ratio of each pixel of the display panel at each gray level based on all drift prediction values ​​with DCI-P3 color gamut coverage as the optimization target, and then construct a dynamic color gamut compensation coefficient matrix based on all dynamic compensation coefficients. The execution module is used to adjust the driving pulse width modulation signal pixel by pixel based on the compensation coefficient matrix, generate a calibrated driving signal, and output the driving signal to the display panel driving circuit to complete the color consistency calibration.

[0013] Thirdly, this application provides a computer device, the computer device including a memory and a processor, the memory storing code, the processor being configured to acquire the code and execute the above-described color consistency calibration method for a miniature LED display panel.

[0014] Fourthly, this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for color consistency calibration of a miniature LED display panel.

[0015] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects: This application provides a method and system for color consistency calibration of a miniature LED display panel. The method involves simultaneously acquiring junction temperature and current density data for each pixel area of ​​the miniature LED display panel under current driving conditions, and then determining the electrothermal coupling state of the display panel based on the junction temperature and current density data. A state space model is constructed based on the electrothermal coupling state, and the chromaticity coordinate offset of each pixel under the current junction temperature and current density coupling effect is predicted using the state space model to obtain the predicted chromaticity drift value for each pixel. With DCI-P3 color gamut coverage as the optimization target, the dynamic compensation coefficients for the red, green, and blue ratios of each pixel at each grayscale level are determined based on all the predicted drift values. A dynamic color gamut compensation coefficient matrix is ​​then constructed based on all the dynamic compensation coefficients. The driving pulse width modulation signal is adjusted pixel-by-pixel based on the compensation coefficient matrix to generate a calibrated driving signal, which is then output to the display panel driving circuit to complete the color consistency calibration.

[0016] Therefore, this application, firstly, overcomes the limitations of existing technologies that rely solely on fixed operating parameters or single temperature monitoring by constructing an electrothermal coupling state, achieving accurate real-time perception of pixel-level electrothermal coupling state and providing a reliable state input basis for dynamic color calibration; secondly, by performing nonlinear mapping processing on the electrothermal coupling state and constructing a state space model, it can accurately predict the chromaticity coordinate offset of each pixel under the coupling effect of junction temperature and current density, solving the deficiency of existing technologies that do not establish a chromaticity drift prediction model for pixel-level electrothermal coupling effect, and significantly improving the accuracy and adaptability of chromaticity deviation prediction; then, to ensure With maximizing DCI-P3 color gamut coverage as the constraint, the dynamic compensation coefficients of the red, green, and blue ratios of each pixel in the full grayscale are calculated and a compensation coefficient matrix is ​​generated. This enables fine-grained color compensation while ensuring wide color gamut coverage, effectively balancing color gamut retention and full pixel color uniformity. Finally, the compensation coefficient matrix is ​​mapped pixel by pixel to the adjustment amount of the driving pulse width modulation signal and directly output to the driving circuit to complete the calibration, forming a closed-loop dynamic calibration mechanism from state perception and deviation prediction to compensation execution. This mechanism can continuously maintain panel color consistency under different driving loads and temperature conditions, significantly improving the image quality stability and display quality of the Mini LED display panel. In summary, based on the above scheme, pixel-level dynamic color calibration based on real-time electrothermal coupling state perception can be achieved to improve color consistency under all operating conditions. Attached Figure Description

[0017] Figure 1 This is an exemplary flowchart of a color consistency calibration method for a miniature LED display panel according to some embodiments of this application; Figure 2This is a flowchart illustrating the operation of determining drift prediction values ​​according to some embodiments of this application; Figure 3 This is an exemplary flowchart illustrating the determination of dynamic compensation coefficients according to some embodiments of this application; Figure 4 This is a schematic diagram of the structure of a color consistency calibration system for a miniature LED display panel according to some embodiments of this application; Figure 5 This is a schematic diagram of the structure of a computer device for implementing a color consistency calibration method for a miniature LED display panel, according to some embodiments of this application. Detailed Implementation

[0018] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] refer to Figure 1 The figure is an exemplary flowchart of a color consistency calibration method for a miniature LED display panel according to some embodiments of this application. The figure mainly includes the following steps: In step 101, junction temperature data and current density data of each pixel area of ​​the mini LED display panel under the current driving conditions are collected simultaneously, and then the electrothermal coupling state of the display panel is determined based on the junction temperature data and the current density data.

[0020] It should be noted that, in this application, junction temperature data refers to the data composed of the actual temperature values ​​of the active region of the micro LED chip during the power-on process; current density data refers to the data composed of the driving current values ​​passing through a unit light-emitting area.

[0021] In some embodiments, the synchronous acquisition of junction temperature and current density data of each pixel area of ​​the mini LED display panel under the current driving conditions can be achieved in the following manner: First, the junction temperature data of each pixel area of ​​the display panel under the current driving conditions can be synchronously acquired by a temperature sensing array integrated on the backplane of the display panel driver. This temperature sensing array consists of multiple temperature sensing blocks distributed in an array on the backplane of the driver. Each temperature sensing block is made of a positive temperature coefficient thermistor material and is directly connected to the controller through corresponding wires. Each temperature sensing block senses the heat of its pixel area in real time and outputs a resistance value signal that changes with temperature. After receiving the resistance value signals output by each temperature sensing block, the controller... Based on the preset correspondence between the resistance value and temperature in the positive temperature coefficient thermistor, the resistance value signal is converted into the junction temperature value of each pixel region, and then the dataset composed of the junction temperature values ​​of all pixel regions is used as the junction temperature data. At the same time, the driving current of each pixel region under the current driving conditions can be synchronously collected by the current detection module in the display panel driving circuit. The current detection module detects the driving current flowing through each sub-pixel through the detection line connected to each column of sub-pixels, and then divides the light-emitting area of ​​each pixel region by the driving current to obtain the current density of each pixel region. Then, the dataset composed of the current densities of all pixel regions is used as the current density data.

[0022] In some embodiments, determining the electrothermal coupling state of the display panel based on the junction temperature data and the current density data can be achieved using the following steps: Spatial registration is performed on the junction temperature data and the current density data to obtain registered junction temperature data and current density data; Vector fusion is performed based on the registered junction temperature data and current density data to construct the electrothermal coupling state vector of each pixel of the display panel; The electrothermal coupling state of the display panel is determined based on the electrothermal coupling state vectors of all pixels.

[0023] It should be noted that in this application, the electrothermal coupling state vector is a two-dimensional vector representing the real-time physical state of the pixel under the action of electrothermal coupling; the electrothermal coupling state is a set of state vectors representing the real-time physical state distribution of the entire display panel under the action of electrothermal coupling; this application distinguishes and jointly expresses junction temperature and current density as electrothermal coupling state from the perspective of physical mechanism, so that the prediction of subsequent chromaticity coordinate offset can be based on dual-dimensional input data of each pixel that simultaneously covers temperature and current factors, avoiding the chromaticity prediction deviation caused by simplifying the electrothermal coupling effect to a single variable compensation.

[0024] In practical implementation, firstly, spatial registration can be performed on the junction temperature data and current density data. Since the physical distribution of temperature sensing blocks in the temperature sensing array is sparse and does not correspond one-to-one with the pixel coordinates of the display panel, the junction temperature data only represents the temperature values ​​at discrete sampling points. However, there is no directly corresponding measured junction temperature value at each pixel coordinate location. Therefore, spatial interpolation is performed on the junction temperature data. Based on the junction temperature values ​​at known surrounding temperature sensing block locations, the estimated junction temperature value at each pixel coordinate location is calculated, resulting in junction temperature data that corresponds one-to-one with the pixel coordinates of the display panel. Simultaneously, the current density data itself is the measured value at each pixel coordinate location. Therefore, simply arranging the current density data according to the pixel coordinates yields the junction temperature data that corresponds one-to-one with the pixel coordinates of the display panel. The current density data corresponding to each pixel coordinate on the panel is used to obtain the registered junction temperature data and current density data. Then, using each pixel coordinate as an index, the junction temperature value in the junction temperature data and the current density value in the current density data at the same pixel coordinate are vector-fused, that is, the junction temperature value and the current density value are used as two independent components to construct a vector, and the constructed vector is used as the electrothermal coupling state vector, thereby constructing the electrothermal coupling state vector for each pixel. Finally, the electrothermal coupling state vectors of all pixels are organized according to the spatial arrangement order of each pixel on the display panel to form a set of electrothermal coupling state vectors consistent with the pixel array structure of the display panel as the electrothermal coupling state of the display panel.

[0025] In step 102, a state space model is constructed based on the electrothermal coupling state. Then, the chromaticity coordinate offset of each pixel on the display panel under the coupling effect of the current junction temperature and current density is predicted through the state space model to obtain the drift prediction value of the chromaticity of each pixel.

[0026] In some embodiments, reference Figure 2 The figure is a flowchart illustrating the operation of determining the drift prediction value according to some embodiments of this application. In this application, a state space model is constructed based on the electrothermal coupling state, and then the chromaticity coordinate offset of each pixel of the display panel under the coupling effect of the current junction temperature and current density is predicted through the state space model. The drift prediction value of the corresponding chromaticity of each pixel can be obtained by the following steps: Construct a state-space model of electrothermal coupling based on the aforementioned electrothermal coupling state; For each pixel of the display panel, the junction temperature and current density of the pixel region are nonlinearly mapped through the state space model to obtain the linear offset of the chromaticity coordinates of the pixel region under the temperature effect and the nonlinear offset under the current density effect. The linear offset and the nonlinear offset are superimposed to obtain the predicted offset value of the chromaticity coordinate of the pixel region under the coupling effect of the current junction temperature and current density. The pixel chromaticity drift prediction value is determined based on the reference chromaticity coordinates of the pixel region under standard reference conditions and the offset prediction value, thereby obtaining the chromaticity drift prediction value for each pixel.

[0027] It should be noted that in this application, the state-space model is a mathematical mapping relationship that describes the chromaticity coordinate offset law under electrothermal coupling. It can incorporate thermal effects and electrical effects into a unified mathematical framework for joint characterization from the perspective of physical mechanism, avoiding the chromaticity prediction deviation caused by simplifying the electrothermal coupling effect to a single variable compensation.

[0028] In practical implementation, firstly, the state space modeling of the electrothermal coupling state vector of each pixel in the electrothermal coupling state can be performed based on the pre-stored electrothermal coupling-chromaticity drift mapping relationship. Specifically, the junction temperature and current density of each pixel are used as input state variables, and the difference between the chromaticity coordinates of each pixel under standard reference conditions and the chromaticity coordinates under the current driving conditions is used as the output variable to construct the electrothermal coupling state space model. Then, for each pixel of the display panel, a nonlinear mapping calculation is performed on the junction temperature and current density values ​​of the pixel through the state space model. Specifically, a linear regression algorithm is used to process the junction temperature values. The linear offset of the pixel chromaticity coordinates under temperature effect is obtained. The current density value is processed by a multinomial regression algorithm to obtain the nonlinear offset of the pixel chromaticity coordinates under current density effect. The linear offset and the nonlinear offset are then vector-superimposed to obtain the predicted offset value of the pixel chromaticity coordinates under the coupling effect of the current junction temperature and current density. The difference between the predicted offset value and the reference chromaticity coordinates of the pixel under standard reference conditions is calculated, and this difference is used as the predicted chromaticity drift value of the pixel under the current electrothermal coupling state. The predicted chromaticity drift value of each pixel can be obtained through the above steps.

[0029] It should be noted that, in this application, the linear offset refers to the displacement component of the chromaticity coordinates on the chromaticity diagram along a fixed direction caused by changes in junction temperature. It can linearly quantify the driving effect of temperature on the chromaticity coordinates, allowing the pattern of temperature-induced chromaticity drift to be quickly identified through linear regression. The nonlinear offset refers to the displacement component of the chromaticity coordinates on the chromaticity diagram that exhibits a nonlinear curvilinear relationship caused by changes in current density. It can accurately characterize the complex driving effect of current density on the chromaticity coordinates through a nonlinear mapping relationship, compensating for the inability of linear models to characterize higher-order variations in current density-induced chromaticity drift. The shortcomings of the chromaticity law; the offset prediction value refers to the comprehensive chromaticity coordinate displacement of a pixel under the coupling effect of the current junction temperature and current density. It can realize the coupling characterization of thermal and electrical effects on the chromaticity coordinate through the superposition of linear and nonlinear components, providing a comprehensive chromaticity coordinate offset basis for the subsequent determination of chromaticity drift; the drift prediction value is the final chromaticity offset of a pixel under the current electrothermal coupling state. It can transform the abstract chromaticity coordinate offset into a pixel-level chromaticity deviation value that can be directly used for compensation coefficient calculation, providing a pixel-by-pixel quantization input benchmark for the subsequent determination of dynamic compensation coefficient.

[0030] In step 103, with DCI-P3 color gamut coverage as the optimization target, the dynamic compensation coefficient of the red, green and blue ratio of each pixel of the display panel at each gray level is determined based on all drift prediction values, and then a dynamic color gamut compensation coefficient matrix is ​​constructed based on all dynamic compensation coefficients.

[0031] In some embodiments, reference Figure 3 The figure is an exemplary flowchart illustrating the determination of dynamic compensation coefficients according to some embodiments of this application. In this application, the DCI-P3 color gamut coverage is used as the optimization target. The dynamic compensation coefficients for the red, green, and blue ratios of each pixel of the display panel at each grayscale level are determined based on all drift prediction values ​​using the following steps: In step 1031, for each pixel of the display panel, the red-green-blue ratio adjustment amount of the pixel at each gray level is determined based on the pixel's drift prediction value. In step 1032, with the DCI-P3 color gamut coverage as the optimization target, the target optimization is performed based on the red-green-blue ratio adjustment amount to obtain the red-green-blue ratio of the pixel to achieve the DCI-P3 color gamut coverage optimization target at each gray level; In step 1033, the dynamic compensation coefficient of the red-green-blue ratio of the pixel at each gray level is determined according to the red-green-blue ratio and the standard red-green-blue ratio, thereby obtaining the dynamic compensation coefficient of the red-green-blue ratio of each pixel of the display panel at each gray level.

[0032] It should be noted that in this application, the red-green-blue ratio adjustment amount is the degree of change in the proportion of the three primary colors required by the pixel at each gray level, which can give the color compensation a clear physical adjustment direction; the red-green-blue ratio refers to the proportional relationship between the brightness of the red sub-pixels, green sub-pixels and blue sub-pixels in the driving display panel pixels, which is used to accurately control the chromaticity coordinates after pixel mixing by adjusting the relative magnitude of the brightness of the three primary colors; the dynamic compensation coefficient is the quantization factor that finally corrects the driving signal of each pixel, which can be used to convert the color drift prediction result into a numerical compensation parameter that can be directly applied to the pulse width modulation signal; the three together constitute the complete compensation link from color deviation identification to driving signal correction in this solution, ensuring that each pixel achieves accurate color reproduction guided by the DCI-P3 (Digital Cinema Initiatives-P3) color gamut coverage at each gray level.

[0033] In practical implementation, for each pixel of the display panel, firstly, the offset direction and magnitude contained in the pixel's drift prediction value are obtained. Then, based on the three-primary-color mixing principle in color science, the offset direction and magnitude are inversely mapped to the adjustment direction and magnitude of the red, green, and blue (RGB) primary color ratios as the RGB ratio adjustment amount. Next, with DCI-P3 color gamut coverage as the optimization target, this RGB ratio adjustment amount is used as the initial reference value for each primary color ratio adjustment. The upper and lower limits of each primary color ratio within the physical driving capability range are used as constraint boundaries, and the RGB ratio of the pixel at each grayscale level is used as... The decision variables to be optimized are iteratively searched around the initial baseline value. A multi-objective optimization algorithm is used to iteratively optimize the red-green-blue ratio of the pixel at each gray level to obtain the red-green-blue ratio adjustment amount that optimizes the DCI-P3 color gamut coverage. This red-green-blue ratio is used as the red-green-blue ratio of the pixel at each gray level to achieve the DCI-P3 color gamut coverage optimization target. Finally, the difference between this red-green-blue ratio and the standard red-green-blue ratio is used as the dynamic compensation coefficient of the red-green-blue ratio of the pixel at each gray level. Through the above steps, the dynamic compensation coefficient of the red-green-blue ratio of each pixel of the display panel at each gray level can be obtained.

[0034] In some embodiments, constructing the compensation coefficient matrix for the dynamic color gamut based on all dynamic compensation coefficients can be achieved using the following steps: All dynamic compensation coefficients are arranged in the same spatial arrangement as the pixel array of the display panel to obtain the initial coefficient matrix of the dynamic color gamut; Gray-level smoothing is performed on the dynamic compensation coefficients of each pixel in the initial compensation coefficient matrix to obtain the intermediate coefficient matrix of the dynamic color gamut. Spatial low-pass filtering is performed on the dynamic compensation coefficients of each pixel in the intermediate coefficient matrix to obtain the dynamic color gamut compensation coefficient matrix.

[0035] It should be noted that, in this application, the initial coefficient matrix refers to the original data matrix constructed by arranging the dynamic compensation coefficients of all pixels in the same spatial manner as the pixel array of the display panel; the intermediate coefficient matrix refers to the transition data matrix obtained after gray-level smoothing, which can eliminate the discontinuous gray-level transition caused by abrupt changes in compensation coefficients between adjacent gray levels; the compensation coefficient matrix refers to the final data matrix obtained after spatial domain low-pass filtering, which can eliminate the inter-pixel color jump caused by abrupt changes in compensation coefficients between adjacent pixels, thereby avoiding the introduction of new gray-level faults or spatial textures while correcting color deviations.

[0036] In specific implementation, firstly, the dynamic compensation coefficients of all pixels can be arranged one by one in the same spatial arrangement as the pixel array of the display panel to obtain a matrix with the same size as the pixel array of the display panel as the initial coefficient matrix of the dynamic color gamut. Then, the dynamic compensation coefficients of each pixel in the initial coefficient matrix at each gray level are smoothed in the gray level direction. That is, the compensation coefficients of each measured gray level point are interpolated and fitted using cubic spline curves to make the compensation coefficients between each gray level form a continuous and smooth change curve, avoiding unnatural gray level transitions caused by abrupt changes in compensation coefficients between adjacent gray levels, thus obtaining the intermediate coefficient matrix of the dynamic color gamut. Finally, the dynamic compensation coefficients of each pixel in the intermediate coefficient matrix are subjected to low-pass filtering in the spatial domain. That is, for each pixel, a neighborhood window of a preset size is taken with the pixel as the center, and the compensation coefficients of each pixel in the neighborhood window are multiplied by the weight values ​​of the corresponding positions of the Gaussian kernel function and accumulated. The accumulated result is used as the filtered compensation coefficient of the pixel, so that the compensation coefficients between adjacent pixels transition continuously and smoothly in space, thus obtaining the compensation coefficient matrix of the dynamic color gamut.

[0037] In step 104, the driving pulse width modulation signal is adjusted pixel by pixel based on the compensation coefficient matrix to generate a calibrated driving signal, and the driving signal is output to the display panel driving circuit to complete the color consistency calibration.

[0038] In some embodiments, adjusting the drive pulse width modulation signal pixel-by-pixel based on the compensation coefficient matrix to generate a calibrated drive signal can be achieved through the following steps: The compensation coefficient matrix is ​​decomposed according to the red, green and blue sub-pixel channels of the pixels to obtain the red sub-pixel compensation coefficient, green sub-pixel compensation coefficient and blue sub-pixel compensation coefficient of each pixel; For each pixel of the display panel, the duty cycle adjustment of the driving pulse width modulation signal of each sub-pixel in the pixel area is calculated according to the red sub-pixel compensation coefficient, green sub-pixel compensation coefficient and blue sub-pixel compensation coefficient of the pixel. Based on all duty cycle adjustments, the calibrated drive signal of each pixel is generated, thereby obtaining the calibrated drive signal of each pixel on the display panel. The calibrated drive signals of all pixels are synthesized according to the pixel spatial arrangement of the display panel to generate the calibrated drive signal.

[0039] It should be noted that, in this application, the red sub-pixel compensation coefficient is a scaling factor that independently adjusts the driving intensity of the red sub-pixels in each pixel of the display panel; the green sub-pixel compensation coefficient is a scaling factor that independently adjusts the driving intensity of the green sub-pixels in each pixel of the display panel; the blue sub-pixel compensation coefficient is a scaling factor that independently adjusts the driving intensity of the blue sub-pixels in each pixel of the display panel, used to correct the chromaticity coordinate offset of each pixel caused by the electrothermal coupling effect from the three color channels of red, green and blue; the duty cycle adjustment amount is a correction amount of the proportion of the high-level conduction time in the driving pulse width modulation signal to the entire signal cycle, used to control the cumulative emission time of each sub-pixel in each frame cycle to achieve chromaticity compensation; the calibrated driving signal is a driving pulse width modulation signal containing the target duty cycle information of each sub-pixel; the driving signal is an electrical signal output by the display panel driving circuit to each pixel electrode to control the emission brightness of each sub-pixel.

[0040] In specific implementation, firstly, the dynamic compensation coefficients of each pixel in the compensation coefficient matrix are decomposed according to the red, green, and blue sub-pixel channels of the pixel. That is, the red, green, and blue sub-pixel compensation coefficients at the corresponding pixel positions are extracted from the dynamic compensation coefficients, thus obtaining the red, green, and blue sub-pixel compensation coefficients for each pixel. Then, for each pixel of the display panel, the red sub-pixel compensation coefficient of the pixel is multiplied by the original value of the duty cycle of the current driving pulse width modulation signal of the red sub-pixel to obtain the duty cycle adjustment amount of the red sub-pixel. The green sub-pixel compensation coefficient of the pixel is multiplied by the original value of the current driving pulse width modulation signal duty cycle of the green sub-pixel to obtain the duty cycle adjustment amount of the green sub-pixel. The blue sub-pixel compensation coefficient of the pixel is multiplied by the original value of the current driving pulse width modulation signal duty cycle of the blue sub-pixel to obtain the duty cycle adjustment amount of the blue sub-pixel. Thus, the duty cycle adjustment amount of each sub-pixel in the pixel area is obtained. The duty cycle of the driving pulse width modulation signal is adjusted; then, the original duty cycle of the current driving pulse width modulation signal of the red sub-pixel is replaced with the duty cycle adjustment of the red sub-pixel to generate a calibrated red driving pulse width modulation signal. The original duty cycle of the current driving pulse width modulation signal of the green sub-pixel is replaced with the duty cycle adjustment of the green sub-pixel to generate a calibrated green driving pulse width modulation signal. The original duty cycle of the current driving pulse width modulation signal of the blue sub-pixel is replaced with the duty cycle adjustment of the blue sub-pixel to generate a calibrated blue driving pulse width modulation signal. The signal composed of the red, green, and blue driving pulse width modulation signals is then used as the calibrated driving signal of the pixel. The calibrated driving signal of each pixel can be obtained through the above steps. Finally, the calibrated driving signals of all pixels are time-sequentially synthesized according to the pixel spatial arrangement of the display panel to generate the calibrated driving signal of the display panel.

[0041] In some embodiments, outputting the driving signal to the display panel driving circuit to complete color consistency calibration can be achieved by the following steps: The driving signal is output to each pixel electrode in a line scanning manner through the display panel driving circuit; The micro LED chips on each pixel are driven to emit light according to the corrected conduction time ratio in the driving signal, thus completing the full-screen color consistency calibration.

[0042] It should be noted that in this application, the pixel electrode is an electrical connection node in the display panel that is directly connected to the output terminal of the pixel driving circuit of each pixel and is used to control the light emission brightness of each chip.

[0043] In specific implementation, firstly, the gate driving circuit in the display panel driving circuit can sequentially output row selection signals to each row of pixel electrodes of the display panel in a row-by-row scanning manner. Simultaneously, as each row of pixel electrodes is selected by the row selection signal, the data driving circuit in the display panel driving circuit loads the driving signals of each pixel in that row onto the corresponding column data lines. This data driving circuit includes a number of digital-to-analog conversion channels equal to the number of columns in the display panel. Each digital-to-analog conversion channel converts the digital duty cycle information in the calibrated driving signal of each pixel into an analog voltage signal or an analog current signal, and transmits the converted analog signals to the pixel driving circuits of each pixel in the currently selected row through their respective column data lines. Then, the pixel driving circuit of each pixel controls the conduction time of the red, green, and blue micro-LED chips in that pixel within each frame period according to the received analog signals. The LED emits light only during the time period when the corresponding row selection signal is valid and the column data line has a drive signal. Its actual light emission duration is determined by the corrected conduction time ratio in the calibrated drive signal. As the gate drive circuit outputs row selection signals row by row, all row pixel electrodes of the display panel are sequentially selected and receive their respective calibrated drive signals. The micro LED chips of all pixels emit light sequentially according to their respective corrected conduction time ratios. After the last row pixel is driven, the entire display panel can achieve full-screen color consistency calibration. The gate drive circuit is composed of cascaded shift register units. Each shift register unit corresponds to one row of pixel electrodes on the display panel. The output signal of the previous shift register unit serves as the start signal of the next shift register unit. Under the control of the clock signal, each shift register unit sequentially generates a high-level valid row selection pulse, so that each row pixel electrode of the display panel is selected one by one in the time order from the first row to the last row.

[0044] In another aspect, in some embodiments, this application provides a color consistency calibration system for a miniature LED display panel, with reference to... Figure 4 The figure is a schematic diagram of the structure of a color consistency calibration system for a miniature LED display panel according to some embodiments of this application, including: a data acquisition module 201, a processing module 202, and an execution module 203, which are described below: The acquisition module 201 in this application is mainly used to synchronously acquire junction temperature data and current density data of each pixel area of ​​the mini LED display panel under the current driving conditions, and then determine the electrothermal coupling state of the display panel based on the junction temperature data and the current density data. Processing module 202, in this application, is used to construct a state space model based on the electrothermal coupling state, and then use the state space model to predict the chromaticity coordinate offset of each pixel of the display panel under the current junction temperature and current density coupling, so as to obtain the drift prediction value of the chromaticity of each pixel. It should be noted that the processing module 202 is also used to determine the dynamic compensation coefficient of the red, green and blue ratio of each pixel of the display panel at each gray level based on all the drift prediction values ​​with the DCI-P3 color gamut coverage as the optimization target, and then construct the compensation coefficient matrix of the dynamic color gamut based on all the dynamic compensation coefficients. The execution module 203 in this application is mainly used to adjust the driving pulse width modulation signal pixel by pixel based on the compensation coefficient matrix, generate a calibrated driving signal, and output the driving signal to the display panel driving circuit to complete the color consistency calibration.

[0045] The foregoing has detailed examples of the color consistency calibration method and system for miniature Mini LED display panels provided in this application. It is understood that the corresponding apparatus, in order to achieve the above functions, includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specified application, but such implementation should not be considered beyond the scope of this application.

[0046] In some embodiments, this application also provides a computer device, the computer device including a memory and a processor, the memory for storing a computer program, and the processor for calling and running the computer program from the memory, so that the computer device performs the above-described color consistency calibration method for a miniature LED display panel.

[0047] In some embodiments, reference Figure 5 The dashed lines in the figure indicate that the unit or module is optional. This figure is a schematic diagram of the structure of a computer device for implementing a color consistency calibration method for a miniature LED display panel according to an embodiment of this application. The color consistency calibration method for a miniature LED display panel described in the above embodiments can be achieved through… Figure 5 The computer device shown is used to implement this, and the computer device includes at least one processor 301, a memory 302 and at least one communication unit 305. The computer device may be a terminal device, a server or a chip.

[0048] Processor 301 can be a general-purpose processor or a special-purpose processor. For example, processor 301 can be a central processing unit (CPU), which can be used to control computer devices, execute software programs, and process data from software programs. The computer device may also include a communication unit 305 for inputting (receiving) and outputting (transmitting) signals.

[0049] For example, the computer device may be a chip, and the communication unit 305 may be the input and / or output circuit of the chip, or the communication unit 305 may be the communication interface of the chip, which may be a component of a terminal device, network device or other device.

[0050] For example, the computer device may be a terminal device or a server, and the communication unit 305 may be a transceiver of the terminal device or the server, or the communication unit 305 may be a transceiver circuit of the terminal device or the server.

[0051] The computer device may include one or more memories 302 storing a program 304. The program 304 can be executed by a processor 301 to generate instructions 303, causing the processor 301 to execute the method described in the above method embodiments according to the instructions 303. Optionally, the memory 302 may also store data (such as a target audit model). Optionally, the processor 301 may also read data stored in the memory 302, which may be stored at the same storage address as the program 304, or it may be stored at a different storage address than the program 304.

[0052] The processor 301 and memory 302 can be configured separately or integrated together, for example, integrated on the system on chip (SOC) of the terminal device.

[0053] It should be understood that each step of the above method embodiment can be completed by hardware logic circuits or software instructions in the processor 301. The processor 301 can be a CPU, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, such as discrete gates, transistor logic devices, or discrete hardware components.

[0054] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0055] For example, in some embodiments, this application also provides a computer-readable storage medium storing instructions or code that, when executed on a computer, cause the computer to implement the above-described color consistency calibration method for a miniature LED display panel.

[0056] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0057] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for color consistency calibration of a miniature LED display panel, characterized in that, Includes the following steps: Synchronously collect junction temperature data and current density data of each pixel area of ​​the mini LED display panel under the current driving conditions, and then determine the electrothermal coupling state of the display panel based on the junction temperature data and the current density data. Based on the electrothermal coupling state, a state space model is constructed, and then the chromaticity coordinate offset of each pixel on the display panel under the coupling effect of the current junction temperature and current density is predicted through the state space model to obtain the drift prediction value of the chromaticity of each pixel. With DCI-P3 color gamut coverage as the optimization target, the dynamic compensation coefficient of the red, green and blue ratio of each pixel in the display panel at each gray level is determined based on all drift prediction values, and then a dynamic color gamut compensation coefficient matrix is ​​constructed based on all dynamic compensation coefficients. The driving pulse width modulation signal is adjusted pixel by pixel based on the compensation coefficient matrix to generate a calibrated driving signal, which is then output to the display panel driving circuit to complete color consistency calibration.

2. The method as described in claim 1, characterized in that, Determining the electrothermal coupling state of the display panel based on the junction temperature data and the current density data specifically includes: Spatial registration is performed on the junction temperature data and the current density data to obtain registered junction temperature data and current density data; Vector fusion is performed based on the registered junction temperature data and current density data to construct the electrothermal coupling state vector of each pixel of the display panel; The electrothermal coupling state of the display panel is determined based on the electrothermal coupling state vectors of all pixels.

3. The method as described in claim 1, characterized in that, Based on the electrothermal coupling state, a state space model is constructed. Then, the chromaticity coordinate offset of each pixel on the display panel under the current junction temperature and current density coupling is predicted using the state space model. The specific predicted drift value of the chromaticity of each pixel includes: Construct a state-space model of electrothermal coupling based on the aforementioned electrothermal coupling state; For each pixel of the display panel, the junction temperature and current density of the pixel region are nonlinearly mapped through the state space model to obtain the linear offset of the chromaticity coordinates of the pixel region under the temperature effect and the nonlinear offset under the current density effect. The linear offset and the nonlinear offset are superimposed to obtain the predicted offset value of the chromaticity coordinate of the pixel region under the coupling effect of the current junction temperature and current density. The pixel chromaticity drift prediction value is determined based on the reference chromaticity coordinates of the pixel region under standard reference conditions and the offset prediction value, thereby obtaining the chromaticity drift prediction value for each pixel.

4. The method as described in claim 1, characterized in that, With DCI-P3 color gamut coverage as the optimization target, the dynamic compensation coefficients for the red, green, and blue ratios of each pixel in the display panel at each grayscale level are determined based on all drift prediction values. Specifically, these coefficients include: For each pixel of the display panel, the red, green and blue ratio adjustment amount of the pixel at each gray level is determined based on the pixel's drift prediction value; With DCI-P3 color gamut coverage as the optimization target, target optimization is performed based on the red-green-blue ratio adjustment amount to obtain the red-green-blue ratio of the pixel to achieve the DCI-P3 color gamut coverage optimization target at each gray level. Based on the stated red-green-blue ratio and the standard red-green-blue ratio, the dynamic compensation coefficient of the red-green-blue ratio of the pixel at each gray level is determined, thereby obtaining the dynamic compensation coefficient of the red-green-blue ratio of each pixel on the display panel at each gray level.

5. The method as described in claim 1, characterized in that, The compensation coefficient matrix for constructing the dynamic color gamut based on all dynamic compensation coefficients specifically includes: All dynamic compensation coefficients are arranged in the same spatial arrangement as the pixel array of the display panel to obtain the initial coefficient matrix of the dynamic color gamut; Gray-level smoothing is performed on the dynamic compensation coefficients of each pixel in the initial compensation coefficient matrix to obtain the intermediate coefficient matrix of the dynamic color gamut. Spatial low-pass filtering is performed on the dynamic compensation coefficients of each pixel in the intermediate coefficient matrix to obtain the dynamic color gamut compensation coefficient matrix.

6. The method as described in claim 1, characterized in that, The drive pulse width modulation signal is adjusted pixel-by-pixel based on the compensation coefficient matrix to generate the calibrated drive signal, specifically including: The compensation coefficient matrix is ​​decomposed according to the red, green and blue sub-pixel channels of the pixels to obtain the red sub-pixel compensation coefficient, green sub-pixel compensation coefficient and blue sub-pixel compensation coefficient of each pixel; For each pixel of the display panel, the duty cycle adjustment of the driving pulse width modulation signal of each sub-pixel in the pixel area is calculated according to the red sub-pixel compensation coefficient, green sub-pixel compensation coefficient and blue sub-pixel compensation coefficient of the pixel. Based on all duty cycle adjustments, the calibrated drive signal of each pixel is generated, thereby obtaining the calibrated drive signal of each pixel on the display panel. The calibrated drive signals of all pixels are synthesized according to the pixel space arrangement of the display panel to generate the calibrated drive signal.

7. The method as described in claim 1, characterized in that, The process of outputting the driving signal to the display panel driving circuit to complete color consistency calibration specifically includes: The driving signal is output to each pixel electrode in a line-scan manner through the display panel driving circuit; The micro LED chips on each pixel are driven to emit light according to the corrected conduction time ratio in the driving signal, thus completing the full-screen color consistency calibration.

8. A color consistency calibration system for a miniature LED display panel, used to perform the color consistency calibration method for a miniature LED display panel as described in any one of claims 1 to 7, characterized in that, include: The acquisition module is used to simultaneously acquire junction temperature data and current density data of each pixel area of ​​the mini LED display panel under the current driving conditions, and then determine the electrothermal coupling state of the display panel based on the junction temperature data and the current density data. The processing module is used to construct a state space model based on the electrothermal coupling state, and then use the state space model to predict the chromaticity coordinate offset of each pixel of the display panel under the current junction temperature and current density coupling, so as to obtain the drift prediction value of the chromaticity of each pixel. The processing module is also used to determine the dynamic compensation coefficient of the red, green and blue ratio of each pixel of the display panel at each gray level based on all drift prediction values ​​with DCI-P3 color gamut coverage as the optimization target, and then construct a dynamic color gamut compensation coefficient matrix based on all dynamic compensation coefficients. The execution module is used to adjust the driving pulse width modulation signal pixel by pixel based on the compensation coefficient matrix, generate a calibrated driving signal, and output the driving signal to the display panel driving circuit to complete the color consistency calibration.

9. A computer device, characterized in that, The computer device includes a memory and a processor, the memory storing code, and the processor being configured to retrieve the code and execute the color consistency calibration method for a miniature LED display panel as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the color consistency calibration method for a miniature LED display panel as described in any one of claims 1 to 7.

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