Display brightness compensation method, display device and computer readable storage medium

Abstract

The invention discloses a display brightness compensation method, a display device and a computer readable storage medium. The display brightness compensation method comprises the following steps: acquiring a compensation model between environment temperatures of a red LED, a green LED and a blue LED and current gains of corresponding constant-current driving chips; detecting whether a display picture of the display panel is a preset picture or not; if the picture is detected to be the preset picture, acquiring actual environment temperatures of the red LED, the green LED and the blue LED; and substituting the actual environment temperatures of the red LED, the green LED and the blue LED into the compensation model to obtain an analog current gain of a corresponding constant-current driving chip, and adjusting the current gain of the corresponding constant-current driving chip to the analog current gain. According to the method, the display brightness and color temperature offset caused by the temperature difference of the LED in the display device can be avoided.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display brightness compensation method, a display device, and a computer-readable storage medium. Background Art

[0002] Liquid crystal displays (LCDs) have become the mainstream in today's flat-panel display market. Since LCD panels themselves don't emit light, they require a backlight module to provide the light source. LEDs (Light-Emitting Diodes) are widely used in backlight modules due to their energy-saving, environmentally friendly, and structurally stable advantages. This is especially true in micro-LED and mini-LED displays, where individual red, green, and blue LEDs can even function as sub-pixels within a single pixel.

[0003] To ensure consistent brightness and color temperature across all locations when displaying pure color images, it's necessary to ensure that the brightness of each LED of the same color is as consistent as possible. However, when the LEDs are running at the same current, variations in operating temperature can cause fluctuations in brightness. Furthermore, the brightness of the RGB colors is affected inconsistently by temperature. This can cause the overall brightness and color temperature of the screen to shift when displaying pure color images, affecting the display quality. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a display brightness compensation method, a display device, and a computer-readable storage medium to prevent the display brightness and color temperature from being offset due to temperature differences of LEDs in the display device.

[0005] The embodiment of the present application discloses a display brightness compensation method, which includes the following steps: Obtain a compensation model between the ambient temperature of the red LED, the green LED, and the blue LED and the current gain of the corresponding constant current driver chip; Detecting whether the display screen of the display panel is a preset screen; If the detection is a preset screen, obtain the actual ambient temperature of the red LED, green LED and blue LED; and The actual ambient temperatures of the red LED, the green LED, and the blue LED are substituted into the compensation model to obtain analog current gains of corresponding constant current driver chips, and the current gains of the corresponding constant current driver chips are adjusted to the analog current gains.

[0006] Optionally, the step of obtaining a compensation model between the ambient temperature of the red LED, the green LED, and the blue LED and the current gain of the corresponding constant current driver chip includes: Obtaining a first linear equation between the luminance of the red LED and the ambient temperature, a second linear equation between the luminance of the green LED and the ambient temperature, and a third linear equation between the luminance of the blue LED and the ambient temperature; Obtaining a first brightness model of the display panel according to the first linear equation, the second linear equation, and the third linear equation; Obtaining a fourth linear equation between the luminance and current of the red LED, a fifth linear equation between the luminance and current of the green LED, and a sixth linear equation between the luminance and current of the blue LED; Obtaining a second brightness model of the display panel according to the fourth linear equation, the fifth linear equation, the sixth linear equation, and the first brightness model; and Combining the second brightness model, a compensation model between the ambient temperature of the red LED, the green LED, and the blue LED and the current gain of the corresponding constant current driver chip is obtained.

[0007] Optionally, the step of obtaining a first linear equation between the luminance of the red LED and the ambient temperature, a second linear equation between the luminance of the green LED and the ambient temperature, and a third linear equation between the luminance of the blue LED and the ambient temperature includes: Obtaining a first relationship curve between the luminance of the red LED and the ambient temperature, a second relationship curve between the luminance of the green LED and the ambient temperature, and a third relationship curve between the luminance of the blue LED and the ambient temperature; Determine n points on the first relationship curve to obtain n sets of first correlation values ​​including the ambient temperature x and the red LED luminance y; Calculate the average value of all ambient temperatures in multiple groups of first associated values and the average brightness of all red LEDs ; According to the formula Calculate the first parameter ,in, 、 and Indicates the ambient temperature in multiple sets of first associated values, 、 and Indicates the red LED luminance in multiple sets of first associated values; According to the formula Calculate the second parameter ; Obtain the first linear equation according to the first parameter and the second parameter ,in, Indicates the actual ambient temperature where the red LED is located. Represents The corresponding red LED brightness; and Obtain the second linear equation through the above steps respectively and the third linear equation ;in, Indicates the actual ambient temperature where the green LED is located. Represents The corresponding green LED luminance is Indicates the actual ambient temperature where the blue LED is located. Represents The corresponding blue LED brightness.

[0008] Optionally, in the step of obtaining a first brightness model of the display panel according to the first linear equation, the second linear equation, and the third linear equation, the first brightness model is: ; in, represents the red light ratio, Indicates the green light ratio, Indicates the blue light ratio, 、 and The sum of the three is equal to 1.

[0009] Optionally, the step of obtaining a fourth linear equation between the luminance and current of the red LED, a fifth linear equation between the luminance and current of the green LED, and a sixth linear equation between the luminance and current of the blue LED includes: Obtaining a fourth relationship curve between the luminance and current of the red LED, a fifth relationship curve between the luminance and current of the green LED, and a sixth relationship curve between the luminance and current of the blue LED; Determine m points on the first relationship curve to obtain m groups of second correlation values ​​including the current i and the red LED luminance y; Calculate the average value of all currents in multiple sets of second correlation values and the average brightness of all red LEDs ; According to the formula Calculate the third parameter ,in, 、 and represents the current in multiple sets of second associated values, 、 and Indicates the red LED luminance in multiple sets of second associated values; According to the formula Calculate the fourth parameter ; Obtain a fourth linear equation according to the third parameter and the fourth parameter ,in, Indicates the current received by the red LED, Represents The corresponding red LED brightness; and Obtain the fifth linear equation through the above steps respectively and the sixth linear equation ;in, Indicates the current received by the green LED, Represents The corresponding green LED luminance is Indicates the current received by the green LED, Represents The corresponding blue LED brightness.

[0010] Optionally, the step of obtaining a second brightness model of the display panel according to the fourth linear equation, the fifth linear equation, the sixth linear equation, and the first brightness model includes: Get current formula ,in, is the reference voltage inside the constant current driver chip, G is the set current gain of the register in the constant current driver chip, and A is the fixed coefficient corresponding to the constant current driver chip. is the resistance value of the external white balance resistor; Substitute the current formula into the four linear equations, the fifth linear equation, and the sixth linear equation to obtain the seventh linear equation. , the eighth linear equation and the ninth linear equation ;as well as by , , , the seventh linear equation, the eighth linear equation and the ninth linear equation are substituted into the first brightness model to obtain a second brightness model of the display panel .

[0011] Optionally, the step of obtaining a compensation model between the ambient temperature of the red LED, the green LED, and the blue LED and the current gain of the corresponding constant current driver chip by combining the second brightness model includes: Obtaining the initial red light ratio in the display panel , Initial green light ratio and the initial blue light ratio ; Combined with the second brightness model and the initial red light ratio coefficient , the initial green light ratio and the initial blue light ratio , get the tenth linear equation 、The eleventh linear equation and the twelfth linear equation ;as well as According to the tenth linear equation, the first compensation model between the ambient temperature of the red LED and the current gain of the corresponding constant current driver chip is obtained. According to the eleventh linear equation, the second compensation model between the ambient temperature of the green LED and the current gain of the corresponding constant current driver chip is obtained. According to the twelfth linear equation, the third compensation model between the ambient temperature of the blue LED and the current gain of the corresponding constant current driver chip is obtained. .

[0012] Optionally, if the detected image is a preset image, the step of obtaining the actual ambient temperatures of the red LED, the green LED, and the blue LED includes: If the detection is the preset screen; Calculate the current received by the red LED, green LED, and blue LED respectively; Calculating the PN junction voltages of the red LED, the green LED, and the blue LED respectively; calculating the junction temperatures of the red LED, the green LED, and the blue LED according to the currents received by the red LED, the green LED, and the blue LED, and the PN junction voltages of the red LED, the green LED, and the blue LED; and The ambient temperatures of the red LED, the green LED, and the blue LED are calculated respectively in combination with the junction temperatures of the red LED, the green LED, and the blue LED.

[0013] An embodiment of the present application further discloses a display device, which includes a driving circuit and a display panel. The driving circuit and the display panel are electrically connected, and the driving circuit uses the above-mentioned display brightness compensation method to adjust the brightness of the display panel.

[0014] An embodiment of the present application further discloses a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps in the display brightness compensation method described above are implemented.

[0015] The beneficial effects of the embodiments of the present application are as follows: the embodiments of the present application establish a compensation model between the ambient temperature of the red LED, green LED and blue LED and the current gain of the corresponding constant current driver chip. When a preset picture needs to be displayed, if the ambient temperature of the red LED, green LED and blue LED changes, the current gain of the constant current driver chip can be adjusted according to the compensation model to compensate for the display brightness and color temperature deviation caused by temperature, thereby avoiding affecting the picture display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation methods of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without inventive work. In the drawings: Figure 1 This is a flow chart of a display brightness compensation method provided by the first embodiment of the present application; Figure 2 This is a flow chart of a method for obtaining a compensation model provided in the first embodiment of the present application; Figure 3 This is a flow chart of a method for obtaining a first linear equation, a second linear equation, and a third linear equation provided in the first embodiment of the present application; Figure 4 is a flow chart of a method for obtaining a fourth linear equation, a fifth linear equation, and a sixth linear equation provided in the first embodiment of the present application; Figure 5 This is a flow chart of a method for obtaining a second brightness model provided in the first embodiment of the present application; Figure 6 This is a flow chart of a method for obtaining a compensation model provided in the first embodiment of the present application; Figure 7 This is a flow chart of a method for obtaining LED ambient temperature provided by the first embodiment of the present application; Figure 8 is a schematic diagram of a display device provided in a second embodiment of the present application; Figure 9 This is a schematic diagram of a computer-readable storage medium provided in the third embodiment of the present application.

[0017] Among them, 100, display device; 110, driving circuit; 111, field programmable gate array; 112, constant current driver chip; 120, display panel; 130, backlight module; 131, light board; 132, LED lamp beads; 133, micro control unit; 200, computer readable storage medium; 210, computer program; 300, processor. DETAILED DESCRIPTION

[0018] It should be understood that the terms used herein, the specific structures and functional details disclosed are only for describing specific embodiments and are representative. However, the present application can be implemented in many alternative forms and should not be construed as being limited to the embodiments described herein.

[0019] In addition, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense, and may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0020] During the production process, LED products are configured based on customer requirements for display brightness and color temperature, which means white balance adjustment is required. For example, if a 6500K color temperature is required, the RGB brightness ratio needs to be adjusted to approximately 3:6:1. The basis of white balance adjustment is the three-primary color principle, which is an important principle for decomposing and mixing colors. From the three-primary color principle, we can know that any color can be represented by different contents of the three primary colors red, green, and blue. Formula This formula is the basis for white balance adjustment. According to this formula, any color light F can be created by adding and mixing the three primary colors R, G, and B in varying proportions. When all three primary color components are zero, color light F is black; when all three primary color components are at their maximum values, color light F is white. Therefore, changing any of the three color coefficients Kr, Kg, and Kb will change the value of F, and thus the displayed color.

[0021] To ensure consistency in brightness and color temperature when displaying pure color images, it is necessary to ensure that the brightness of each LED of the same color is as consistent as possible. Constant current drive is often used to drive LED lamp beads. However, the luminous intensity of LEDs is not only related to its driving current, but also to the temperature of the LED operating environment. At the same time, the brightness and temperature curves of red, green, and blue LEDs also vary under the same current.

[0022] In typical LED products, the intensity of the three LED colors varies inconsistently with ambient temperature, with the red LED's intensity being more sensitive to changes in ambient temperature. This can cause white balance to shift at different temperatures. For example, if the white balance reaches the target color temperature at a certain temperature, as the product continues to operate, the overall temperature rises. This causes the brightness of the red, green, and blue LEDs to decrease due to the temperature rise, with the red LED attenuating more significantly. This shifts the white balance color temperature, resulting in a cooler color temperature on the large screen. Furthermore, when the product is placed in a cold climate, the brightness of the red, green, and blue LEDs increases, with the red LED attenuating more significantly, causing the color temperature on the large screen to shift to a warmer color. This can cause color distortion in the content being played, seriously impacting the user's viewing experience.

[0023] Furthermore, for large screens, since they are often placed perpendicular to the ground, there will be temperature differences between the top and bottom of the screen, as well as between the periphery and the center. Inside the display cabinet, temperature differences also occur due to differences in the distribution of switching power supplies. Inside the display's light board, uneven distribution of heating components and connectors on the circuit board can also cause temperature differences. This can often lead to inconsistent color temperatures across large screen areas. High-temperature areas, where the red LED brightness attenuates more, will produce a greenish tint. Low-temperature areas, where the red LED brightness attenuates less, will produce a near-pure white image.

[0024] Based on the above-mentioned display problem caused by ambient temperature, an embodiment of the present application provides a display brightness compensation method to compensate for the display brightness and color temperature deviation caused by ambient temperature.

[0025] like Figure 1 As shown, as a display brightness compensation method provided in the first embodiment of the present application, the display brightness compensation method includes the steps of: S1: Obtain a compensation model between the ambient temperature of the red LED, green LED, and blue LED and the current gain of the corresponding constant current driver chip; S2: Detect whether the display screen of the display panel is the preset screen; S3: If the detection is the preset screen, the actual ambient temperature of the red LED, green LED and blue LED is obtained; S4: Substituting the actual ambient temperatures of the red LED, the green LED, and the blue LED into the compensation model to obtain analog current gains of corresponding constant current driver chips, and adjusting the current gains of the corresponding constant current driver chips to the analog current gains.

[0026] The embodiments of the present application establish a compensation model between the ambient temperature of the red, green, and blue LEDs and the current gain of the corresponding constant current driver chips. When a preset image needs to be displayed, if the ambient temperature of the red, green, and blue LEDs changes, the current gain of the constant current driver chips can be adjusted according to the compensation model to compensate for the display brightness and color temperature deviations caused by temperature, thereby avoiding affecting the image display effect. Moreover, the embodiments of the present application only need to adjust the current gain of the constant current driver chips to compensate for the display brightness and color temperature deviations caused by temperature. The compensation method is simple and does not require complex regulation or additional circuit and structural design, thus avoiding increased product costs.

[0027] like Figure 2 As shown, the embodiment of the present application provides a method for obtaining a compensation model. Specifically, in step S1, the method includes: S11: Obtain a first linear equation between the luminance of the red LED and the ambient temperature, a second linear equation between the luminance of the green LED and the ambient temperature, and a third linear equation between the luminance of the blue LED and the ambient temperature; S12: Obtaining a first brightness model of the display panel according to the first linear equation, the second linear equation, and the third linear equation; S13: Obtain a fourth linear equation between the luminance and current of the red LED, a fifth linear equation between the luminance and current of the green LED, and a sixth linear equation between the luminance and current of the blue LED; S14: Obtaining a second brightness model of the display panel according to the fourth linear equation, the fifth linear equation, the sixth linear equation, and the first brightness model; S15: Obtain a compensation model between the ambient temperature of the red LED, the green LED, and the blue LED and the current gain of the corresponding constant current driver chip in combination with the second brightness model.

[0028] Through the compensation model provided in the embodiments of the present application, the brightness offset and color temperature offset of the three types of LEDs, namely red LED, green LED and blue LED, caused by the ambient temperature can be compensated respectively. The brightness offset and color temperature offset caused by the ambient temperature of only one color of LED can be compensated, or the brightness offset and color temperature offset caused by the ambient temperature of two or three colors of LED can be compensated; the brightness offset and color temperature offset caused by the ambient temperature of LEDs in a certain area can be compensated; or the brightness offset and color temperature offset caused by the ambient temperature of all LEDs can be compensated.

[0029] The embodiments of the present application first establish a linear equation between the LED luminance and ambient temperature, then obtain a first brightness model based on the linear equation between the luminance of the three-color LED and the ambient temperature. A linear equation between the luminance of the LED and the current is then established, and a second brightness model is obtained based on the linear equation between the luminance of the three-color LED and the current and the first brightness model. Finally, a compensation model between the ambient temperature of the three-color LED and the current gain of the corresponding constant current driver chip is obtained based on the second brightness model. In establishing the compensation model, whether the linear equation between the luminance of the three-color LED and the ambient temperature, the first brightness model, or the linear equation between the luminance of the three-color LED and the current, or the second brightness model, are all derived through reasonable calculations and derivations, closely interconnected, and error-prone, effectively improving the accuracy of the compensation model.

[0030] In the method for obtaining the first, second, and third linear equations, the embodiment of the present application first obtains the light decay curves of the RGB LEDs. For example, the light intensity and ambient temperature curves of the red, green, and blue LEDs can be obtained directly from the LED manufacturer. Alternatively, a finished LED light panel can be manufactured and white balanced. Then, the ambient temperature is varied and the RGB luminous intensity is measured to determine the curves of the light intensity and ambient temperature of the red, green, and blue LEDs.

[0031] Then, based on the light decay curve obtained above, a linear trend curve is drawn (ie, based on the light decay curve obtained above, both ends of the curve are extended) to obtain a first relationship curve, a second relationship curve, and a third relationship curve.

[0032] like Figure 3 As shown, in step S11, it includes: S111: Obtain a first relationship curve between the luminance of the red LED and the ambient temperature, a second relationship curve between the luminance of the green LED and the ambient temperature, and a third relationship curve between the luminance of the blue LED and the ambient temperature; S112: Determine n points on the first relationship curve to obtain n sets of first correlation values ​​including the ambient temperature x and the red LED luminance y; S113: Calculate the average value of all ambient temperatures in multiple groups of first associated values and the average brightness of all red LEDs ; S114: According to the formula Calculate the first parameter ,in, 、 and Indicates the ambient temperature in multiple sets of first associated values, 、 and Indicates the red LED luminance in multiple sets of first associated values; S115: According to the formula Calculate the second parameter ; S116: Obtain the first linear equation according to the first parameter and the second parameter ,in, Indicates the actual ambient temperature where the red LED is located. Represents The corresponding red LED brightness; S117: Obtain the second linear equation through the above steps and the third linear equation ;in, Indicates the actual ambient temperature where the green LED is located. Represents The corresponding green LED luminance is Indicates the actual ambient temperature where the blue LED is located. Represents The corresponding blue LED brightness.

[0033] In the embodiments of the present application, a first linear equation, a second linear equation, and a third linear equation are established using relationship curves and linear regression equation formulas. Multiple points are taken on the relationship curves, and then the average value is calculated. The average value is then substituted into the linear regression equation formula to calculate the parameters. Because the first, second, and third relationship curves are all trend lines, deviations in the results caused by anomalies in one set of data are avoided. Furthermore, by calculating the average value and substituting the average value into the linear regression equation formula to calculate the parameters, the accuracy of the parameters can be improved, thereby improving the accuracy of the first, second, and third linear equations.

[0034] In S112, n is a natural number greater than 2. Of course, the larger the value of n, the better, and the more accurate the formula obtained. The first correlation value can be understood as a coordinate in a two-dimensional coordinate system, with the abscissa being the ambient temperature x and the ordinate being the red LED brightness y.

[0035] In S114, the basic formula is , by deducing the formula, we can get the formula . formula and They are all derived from the linear regression equation formula.

[0036] In S116, the first linear equation obtained is an equation between the actual ambient temperature at the location of the red LED and the luminance of the red LED. In the first linear equation, and These are all parameters, which are specific values. By inputting the actual ambient temperature where the red LED is located, the brightness of the red LED can be obtained.

[0037] In S117, according to the steps of obtaining the first linear equation in S112 to S116, the second linear equation and the third linear equation can be obtained by determining n points on the second relationship curve and n points on the third relationship curve respectively, and then performing parameter calculation, which will not be repeated here.

[0038] In step S12, the first brightness model is: ;in, represents the red light ratio, Indicates the green light ratio, Indicates the blue light ratio, 、 and The sum of these three factors equals 1. The first brightness model reflects the relationship between the ambient temperature and display brightness of the three-color LEDs. After setting the red, green, and blue light ratios, changes in the ambient temperature of any of the three LED colors will cause changes in display brightness. This shows that the first brightness model in this embodiment of the present application is applicable to ambient temperatures at different locations, improving the solution's applicability and accuracy.

[0039] like Figure 4 As shown, the embodiment of the present application further obtains a linear equation between the luminance and current of the LED to establish a second brightness model. Specifically, in step S13, it includes: S131: Obtain a fourth relationship curve between the luminance and current of the red LED, a fifth relationship curve between the luminance and current of the green LED, and a sixth relationship curve between the luminance and current of the blue LED; S132: Determine m points on the first relationship curve to obtain m groups of second correlation values ​​including the current i and the red LED luminance y; S133: Calculate the average value of all currents in multiple sets of second associated values and the average brightness of all red LEDs ; S134: According to the formula Calculate the third parameter ,in, 、 and represents the current in multiple sets of second associated values, 、 and Indicates the red LED luminance in multiple sets of second associated values; S135: According to the formula Calculate the fourth parameter ; S136: Obtain a fourth linear equation based on the third parameter and the fourth parameter ,in, Indicates the current received by the red LED, Represents The corresponding red LED brightness; S137: Obtain the fifth linear equation through the above steps and the sixth linear equation ;in, Indicates the current received by the green LED, Represents The corresponding green LED luminance is Indicates the current received by the green LED, Represents The corresponding blue LED brightness.

[0040] The embodiment of the present application uses the same method as that of obtaining the first linear equation to obtain the fourth linear equation, which is to first establish a relationship curve, then calculate the parameters, and finally obtain the linear equation, which will not be described in detail here. , and These are all specific parameters. By detecting the current of the LED, the specific luminous brightness value can be obtained. Where m is a natural number greater than or equal to 2.

[0041] Similarly, since the fourth relationship curve, the fifth relationship curve and the sixth relationship curve are all trend lines, the deviation of the results caused by a set of abnormal data can be avoided. At the same time, by calculating the average value and substituting the average value into the linear regression equation formula to calculate the parameters, the accuracy of the parameters can be improved, thereby improving the accuracy of the fourth linear equation, the fifth linear equation and the sixth linear equation.

[0042] like Figure 5 As shown, in step S14, it includes: S141: Get current formula ,in, is the reference voltage inside the constant current driver chip, G is the set current gain of the register in the constant current driver chip, and A is the fixed coefficient corresponding to the constant current driver chip. is the resistance value of the external white balance resistor; S142: Substitute the current formula into the fourth linear equation, the fifth linear equation, and the sixth linear equation to obtain a seventh linear equation. , the eighth linear equation and the ninth linear equation ; S143: , , , the seventh linear equation, the eighth linear equation and the ninth linear equation are substituted into the first brightness model to obtain a second brightness model of the display panel .

[0043] In the embodiment of the present application, the LED lamp beads in the LED display are driven by a constant current driver chip. The output current Iout of the constant current driver chip is determined by the register and the external white balance resistor. The external white balance resistor will be added when the light board is manufactured according to customer needs. After that, the output current can only be adjusted by the register in the constant current driver chip. Therefore, after the product is produced, the output current Iout in the formula , A and The above design establishes a model of the LED screen's brightness, current gain, and ambient temperature, known as the second brightness model. When the ambient temperature of the LEDs changes while the current gain remains constant, the red, green, and blue LEDs will fluctuate with the temperature. At this point, according to the second brightness model, changing the current gain of the red, green, and blue LEDs can compensate for the brightness changes caused by temperature.

[0044] The second brightness model provided in the embodiment of the present application can reflect the relationship between the ambient temperature of LEDs of different colors, the current gain of the constant current driver chip that drives the LED, and the brightness of the display panel. When the brightness of the display panel is determined, the current gain of the corresponding constant current driver chip can be adjusted according to the temperature changes of the red LED, green LED and blue LED. The second brightness model can simultaneously obtain the current gains corresponding to the three colors of LEDs, which has higher calculation efficiency.

[0045] As the ambient temperature changes, in order to ensure that the white balance does not change, 、 、 Need to be the initial value 、 、 , which is the value set before leaving the factory and cannot be changed. Figure 6 As shown, in step S15, it includes: S151: Obtaining the initial red light ratio in the display panel , Initial green light ratio and the initial blue light ratio ; S152: Combining the second brightness model and the initial red light proportion coefficient , the initial green light ratio and the initial blue light ratio , get the tenth linear equation 、The eleventh linear equation and the twelfth linear equation ; S153: Obtaining a first compensation model between the ambient temperature of the red LED and the current gain of the corresponding constant current driver chip according to the tenth linear equation According to the eleventh linear equation, the second compensation model between the ambient temperature of the green LED and the current gain of the corresponding constant current driver chip is obtained. According to the twelfth linear equation, the third compensation model between the ambient temperature of the blue LED and the current gain of the corresponding constant current driver chip is obtained. .

[0046] Through the design of step S15, a compensation model consisting of a first compensation model, a second compensation model, and a third compensation model is obtained. Through the first compensation model, the current gain of the constant current driver chip that provides current to the red LED can be adjusted to compensate for the brightness change caused by the ambient temperature change of the red LED; through the second compensation model, the current gain of the constant current driver chip that provides current to the green LED can be adjusted to compensate for the brightness change caused by the ambient temperature change of the green LED; through the third compensation model, the current gain of the constant current driver chip that provides current to the blue LED can be adjusted to compensate for the brightness change caused by the ambient temperature change of the blue LED. The embodiment of the present application can adjust the constant current driver chips corresponding to the three colors of LEDs separately to achieve the effect of precise compensation.

[0047] Because each LED lamp bead is located in a different position and is exposed to a different ambient temperature, in order to accurately measure the LED temperature within the control area of ​​a constant current driver chip, each constant current driver chip must be used as the minimum unit. If thermistors are used to measure the LED temperature within each constant current driver chip control area, it will increase the product process cost. In addition, the thermistors themselves will generate heat, causing new problems.

[0048] Based on the above problems, the embodiment of the present application obtains the ambient temperature of the LED by calculation, such as Figure 7 As shown, in step S3, it includes: S31: If the detection is a preset screen; S32: Calculate the current received by the red LED, the green LED, and the blue LED respectively; S33: Calculating the PN junction voltages of the red LED, the green LED, and the blue LED respectively; S34: Calculating the junction temperatures of the red LED, the green LED, and the blue LED according to the currents received by the red LED, the green LED, and the blue LED, and the PN junction voltages of the red LED, the green LED, and the blue LED; S35: Calculate the ambient temperatures of the red LED, the green LED, and the blue LED respectively based on the junction temperatures of the red LED, the green LED, and the blue LED.

[0049] In order to accurately obtain the ambient temperature of each LED, the junction temperature of each LED can be obtained through the PN junction voltage of the LED. According to semiconductor physics theory, the relationship between the forward voltage, current and PN junction temperature of an ideal PN junction is: , where U represents the PN junction voltage, I represents the current, T represents the junction temperature, C represents parameters related to chip manufacturing, Eg represents the band gap, q represents the electron charge, and K represents the Boltzmann constant. From the formula, we can see that for a finished LED, the PN junction voltage is related to the junction temperature, and the relationship is linear. In the formula, except for the PN junction voltage, junction temperature and current parameters, the other parameters are constants, and the current can be calculated by the current formula in step S141 Therefore, the LED junction temperature can be calculated by the PN junction voltage.

[0050] The junction temperature formula is , where T is the junction temperature, Ta is the ambient temperature, and Pd is the input power minus the optical output power. Represents thermal resistance. The ambient temperature is derived from the junction temperature formula .

[0051] Therefore, we can calculate the PN junction voltage of the LED first and then use the formula Calculate the LED junction temperature and finally use the formula Calculate the ambient temperature of the LED. The entire process does not require the use of measurement tools. The LED ambient temperature is obtained in a convenient and accurate manner.

[0052] As for the method of obtaining the PN junction voltage of LED, since LED is a diode structure, one end of it is powered by a constant current driver chip and the other end is grounded, and each row of LEDs is controlled by a MOS tube, it can be obtained by the formula Calculate the PN junction voltage, where Vf represents the PN junction voltage of the LED, VDD represents the power supply voltage provided by the constant current driver chip, Vdrop represents the conduction voltage drop of the MOS tube, and Vds represents the ground voltage of the constant current driver chip output channel.

[0053] In the embodiment of the present application, the current output by the constant current driver chip is less than the upper limit of the LED current. ,Right now Less than , to avoid excessive driving current of the LED, which will reduce the life of the LED and cause damage to the LED.

[0054] In the embodiment of the present application, the preset image is a solid color image, that is, an image that displays a single color in full screen, such as white, black, or blue. The display brightness compensation method provided in the embodiment of the present application is triggered only when a solid color image is displayed, because if the brightness and color temperature shift, the image difference will be more obvious. Compensation is not required when displaying a non-solid color image, because the difference in brightness and color temperature is not obvious, and it cannot be determined that it is caused by the ambient temperature of the LED. Therefore, compensation is not required.

[0055] like Figure 8 As shown, as a display device provided as the second embodiment of the present application, the display device 100 includes a driving circuit 110 and a display panel 120, the driving circuit 110 and the display panel 120 are electrically connected, and the driving circuit 110 adopts the above-mentioned display brightness compensation method to adjust the brightness of the display panel 120.

[0056] The display device 100 further includes a backlight module 130 for providing brightness for the display panel 120 . The backlight module 130 includes a plurality of light boards 131 . Each light board 131 includes a plurality of LED lamp beads 132 and a micro-controller unit (MCU) 133 .

[0057] In some embodiments, the LED lamp beads 132 may also be built into the display panel 120 .

[0058] In the present embodiment, compensation models are established between the ambient temperature of the red, green, and blue LEDs and the current gain of their corresponding constant current driver chips. These models are stored in the driver circuit 110 of the display device 100, specifically in the field-programmable gate array (FPGA) 111. An algorithm for detecting the ambient temperature of the control area of ​​each constant current driver chip 112 or each LED lamp bead 132 can be stored in the microcontroller unit 133 of each light board 131. When displaying images requiring consistent brightness and chromaticity, such as pure colors, the compensation module is triggered to compensate for temperature fluctuations by adjusting the current gain of the constant current driver chip 112, thereby preventing brightness and chromaticity shifts caused by temperature differences in the LED screen. Of course, all algorithms and models can be stored in the driver circuit 110 of the display device 100, or the microcontroller unit 133 of each light board 131 can be considered part of the driver circuit 110.

[0059] like Figure 9 As shown, as a computer-readable storage medium provided in the third embodiment of the present application, the computer-readable storage medium 200 stores a computer program 210, and when the computer program 210 is executed by the processor 300, the steps in the display brightness compensation method as described above are implemented.

[0060] It should be noted that the limitations on the various steps involved in this solution do not limit the order of the steps without affecting the implementation of the specific solution. The steps written in front can be executed first, later, or even simultaneously. The solutions of different embodiments can be combined and applied without conflict. As long as this solution can be implemented, it should be regarded as falling within the scope of protection of this application.

[0061] The above content is a further detailed description of the present application in conjunction with specific optional implementation methods, and the specific implementation of the present application cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the concept of the present application, which should be considered to fall within the scope of protection of the present application.

Claims

1. A display brightness compensation method, characterized in that: Including steps: Obtain a compensation model between the ambient temperature of the red LED, the green LED, and the blue LED and the current gain of the corresponding constant current driver chip; Detecting whether the display screen of the display panel is a preset screen; If the detection is the preset screen, the actual ambient temperature of the red LED, green LED and blue LED is obtained; as well as The actual ambient temperatures of the red LED, the green LED, and the blue LED are substituted into the compensation model to obtain analog current gains of corresponding constant current driver chips, and the current gains of the corresponding constant current driver chips are adjusted to the analog current gains.

2. The display brightness compensation method according to claim 1, wherein: The step of obtaining a compensation model between the ambient temperature of the red LED, the green LED, and the blue LED and the current gain of the corresponding constant current driver chip includes: Obtaining a first linear equation between the luminance of the red LED and the ambient temperature, a second linear equation between the luminance of the green LED and the ambient temperature, and a third linear equation between the luminance of the blue LED and the ambient temperature; Obtaining a first brightness model of the display panel according to the first linear equation, the second linear equation, and the third linear equation; Obtaining a fourth linear equation between the luminance and current of the red LED, a fifth linear equation between the luminance and current of the green LED, and a sixth linear equation between the luminance and current of the blue LED; Obtaining a second brightness model of the display panel according to the fourth linear equation, the fifth linear equation, the sixth linear equation, and the first brightness model; and Combining the second brightness model, a compensation model between the ambient temperature of the red LED, the green LED, and the blue LED and the current gain of the corresponding constant current driver chip is obtained.

3. The display brightness compensation method according to claim 2, wherein: The step of obtaining a first linear equation between the luminance of the red LED and the ambient temperature, a second linear equation between the luminance of the green LED and the ambient temperature, and a third linear equation between the luminance of the blue LED and the ambient temperature includes: Obtaining a first relationship curve between the luminance of the red LED and the ambient temperature, a second relationship curve between the luminance of the green LED and the ambient temperature, and a third relationship curve between the luminance of the blue LED and the ambient temperature; Determine n points on the first relationship curve to obtain n sets of first correlation values ​​including the ambient temperature x and the red LED luminance y; Calculate the average value of all ambient temperatures in multiple groups of first associated values and the average brightness of all red LEDs ; According to the formula Calculate the first parameter ,in, 、 and Indicates the ambient temperature in multiple sets of first associated values, 、 and Indicates the red LED luminance in multiple sets of first associated values; According to the formula Calculate the second parameter ; Obtain the first linear equation according to the first parameter and the second parameter ,in, Indicates the actual ambient temperature where the red LED is located. Represents The corresponding red LED brightness; and Obtain the second linear equation through the above steps respectively and the third linear equation ;in, Indicates the actual ambient temperature where the green LED is located. Represents The corresponding green LED luminance is Indicates the actual ambient temperature where the blue LED is located. Represents The corresponding blue LED brightness.

4. The display brightness compensation method according to claim 3, wherein: In the step of obtaining a first brightness model of the display panel according to the first linear equation, the second linear equation, and the third linear equation, the first brightness model is: ; in, represents the red light ratio, Indicates the green light ratio, Indicates the blue light ratio, 、 and The sum of the three is equal to 1.

5. The display brightness compensation method according to claim 4, wherein: The step of obtaining a fourth linear equation between the luminance and current of the red LED, a fifth linear equation between the luminance and current of the green LED, and a sixth linear equation between the luminance and current of the blue LED includes: Obtaining a fourth relationship curve between the luminance and current of the red LED, a fifth relationship curve between the luminance and current of the green LED, and a sixth relationship curve between the luminance and current of the blue LED; Determine m points on the first relationship curve to obtain m groups of second correlation values ​​including the current i and the red LED luminance y; Calculate the average value of all currents in multiple sets of second correlation values and the average brightness of all red LEDs ; According to the formula Calculate the third parameter ,in, 、 and represents the current in multiple sets of second associated values, 、 and Indicates the red LED luminance in multiple sets of second associated values; According to the formula Calculate the fourth parameter ; Obtain a fourth linear equation according to the third parameter and the fourth parameter ,in, Indicates the current received by the red LED, Represents The corresponding red LED brightness; and Obtain the fifth linear equation through the above steps respectively and the sixth linear equation ;in, Indicates the current received by the green LED, Represents The corresponding green LED luminance is Indicates the current received by the green LED, Represents The corresponding blue LED brightness.

6. The display brightness compensation method according to claim 5, wherein: The step of obtaining a second brightness model of the display panel according to the fourth linear equation, the fifth linear equation, the sixth linear equation, and the first brightness model includes: Get current formula ,in, is the reference voltage inside the constant current driver chip, G is the set current gain of the register in the constant current driver chip, and A is the fixed coefficient corresponding to the constant current driver chip. is the resistance value of the external white balance resistor; Substitute the current formula into the four linear equations, the fifth linear equation, and the sixth linear equation to obtain the seventh linear equation. , the eighth linear equation and the ninth linear equation ;as well as by , , , the seventh linear equation, the eighth linear equation and the ninth linear equation are substituted into the first brightness model to obtain a second brightness model of the display panel .

7. The display brightness compensation method according to claim 6, wherein: The step of obtaining a compensation model between the ambient temperature of the red LED, the green LED, and the blue LED and the current gain of the corresponding constant current driver chip by combining the second brightness model includes: Obtaining the initial red light ratio in the display panel , Initial green light ratio and the initial blue light ratio ; Combined with the second brightness model and the initial red light ratio coefficient , the initial green light ratio and the initial blue light ratio , get the tenth linear equation 、The eleventh linear equation and the twelfth linear equation ;as well as According to the tenth linear equation, the first compensation model between the ambient temperature of the red LED and the current gain of the corresponding constant current driver chip is obtained. According to the eleventh linear equation, the second compensation model between the ambient temperature of the green LED and the current gain of the corresponding constant current driver chip is obtained. According to the twelfth linear equation, the third compensation model between the ambient temperature of the blue LED and the current gain of the corresponding constant current driver chip is obtained. .

8. The display brightness compensation method according to claim 1, wherein: If the detection is a preset screen, the step of obtaining the actual ambient temperature of the red LED, the green LED, and the blue LED includes: If the detection is the preset screen; Calculate the current received by the red LED, green LED, and blue LED respectively; Calculating the PN junction voltages of the red LED, the green LED, and the blue LED respectively; calculating the junction temperatures of the red LED, the green LED, and the blue LED according to the currents received by the red LED, the green LED, and the blue LED, and the PN junction voltages of the red LED, the green LED, and the blue LED; and The ambient temperatures of the red LED, the green LED, and the blue LED are calculated respectively in combination with the junction temperatures of the red LED, the green LED, and the blue LED.

9. A display device, characterized in that: The device comprises a driving circuit and a display panel, wherein the driving circuit and the display panel are electrically connected, and the driving circuit uses the display brightness compensation method according to any one of claims 1 to 8 to adjust the brightness of the display panel.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the display brightness compensation method according to any one of claims 1 to 8 are implemented.

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