Mini-led temperature detection and brightness compensation method and system based on forward pressure drop

Abstract

The application discloses a Mini-LED temperature detection and brightness compensation method based on a forward voltage drop, which is based on a constant current source driving architecture and comprises the following steps: a detection step of applying a predetermined test current I to a Mini-LED sense , collecting a Mini-LED cathode voltage V cathode , calculating a forward voltage drop of the Mini-LED, wherein V LED is the voltage of a public power supply end connected to an anode of the Mini-LED; a calculation step of calculating a current junction temperature of the Mini-LED according to the current forward voltage drop, and matching a brightness attenuation ratio of the Mini-LED from preset "junction temperature-brightness attenuation" relationship data according to the junction temperature; and a compensation step of setting a current value for restoring the brightness of the Mini-LED to a target value according to the calculated brightness attenuation ratio, and driving the Mini-LED according to the new current value by a constant current source chip. The application further discloses a Mini-LED temperature detection and brightness compensation system based on a forward voltage drop.

Description

Technical Field

[0002] This invention relates to a method and system for brightness compensation of Mini-LEDs, specifically to a method and system for temperature detection and brightness compensation of Mini-LEDs based on forward voltage drop. Background Technology

[0004] Mini-LED, as a core component of next-generation display technology, has been widely used in high-end televisions, monitors, and other devices. Mini-LED displays typically contain thousands to tens of thousands of densely packed LED chips. During high-brightness displays or prolonged operation, the junction temperature of the LED chips rises significantly. This increased junction temperature leads to a decrease in the luminous efficacy of the LED, i.e., a reduction in luminous brightness, which causes two main problems:

[0005] Decreased brightness uniformity: Areas with higher temperatures on the screen, such as constantly lit areas, will be darker than the surrounding areas, forming "dark patches" or "cloud patterns," which seriously affects the viewing experience.

[0006] Deterioration in color consistency: Temperature changes can cause the light emission wavelength of LEDs to drift, affecting the accuracy of displayed colors.

[0007] To solve the above problems, existing technologies such as Figure 1 Temperature is typically monitored by mounting discrete thermistors on a printed circuit board, or PCB.

[0008] Another Chinese patent document, CN121411027A, discloses an adaptive zoned dynamic temperature control TV backlight board and its control method, including a PCB board, an LED array, a temperature sensor network, and a dynamic adjustment module. The PCB board has an LED array and a temperature sensor network, which includes multiple digital temperature sensor modules. The LED array is composed of uniformly distributed LED chips. The digital temperature sensor modules are positioned between the LED chips. The PCB board has a dynamic adjustment module, and the LED array, temperature sensor network, and dynamic adjustment module are communicatively connected. This invention significantly increases the lifespan of the LEDs by real-time monitoring of the temperature of each zone of the LED array in the TV backlight board and adjusting it through the dynamic adjustment module. It can reduce ineffective heat generation and energy loss, and eliminate brightness fluctuations and color shifts in HDR scenes by ensuring minimal temperature differences between zones. This patent document also uses a temperature sensor network on the PCB board to measure the temperature of the LED chips. However, in practical applications, it has been found that the existing temperature measurement methods have problems such as temperature and hysteresis, resulting in inconsistent brightness across the entire screen during brightness compensation. Summary of the Invention

[0010] To address the technical problems of temperature difference and hysteresis in existing LED temperature measurement methods, this invention provides a Mini-LED temperature detection and brightness compensation method based on forward voltage drop, implemented within a constant current source driving architecture, and includes the following steps:

[0011] Testing steps: Apply a predetermined test current I to the Mini-LED. sense Collect Mini-LED cathode voltage V cathode The forward voltage drop of the Mini-LED was calculated. , V LED This refers to the voltage at the common power supply terminal connected to the anode of the Mini-LED.

[0012] Calculation steps: Based on the current forward pressure drop Calculate the current junction temperature of the Mini-LED. According to the junction temperature The brightness decay ratio of Mini-LEDs is matched from the preset "junction temperature-brightness decay" relationship data. ;

[0013] Compensation steps: Based on the calculated brightness attenuation ratio Set the current value that will restore the Mini-LED brightness to the target value. The constant current source chip is adjusted according to the new current value. Drive Mini-LED.

[0014] After analyzing the temperature measurement methods of the prior art, the inventors found that the thermistors installed on the PCB in the prior art directly measure the temperature of the environment or the PCB, rather than the junction temperature of the LED chip itself. Therefore, the temperature measured by this method of not directly measuring the LED chip has a temperature difference and lag compared with the junction temperature of the LED chip itself.

[0015] Secondly, due to the limited space on a PCB, only a few thermistors can be placed on the PCB, which makes it impossible to sense the individual temperature differences of thousands of Mini-LEDs on the entire screen. Therefore, it is impossible to achieve precise, pixel-level temperature management and brightness compensation.

[0016] Therefore, in this invention, based on the fundamental principles of semiconductor physics, that is, when a tiny, constant test current much smaller than the current when the LED is emitting light is provided to the PN junction of the LED, the forward voltage drop V of the LED will be... F With junction temperature T jThere will be a strong linear negative correlation, meaning the higher the temperature, the lower the forward voltage drop. Therefore, in a constant current source drive architecture, due to the anode voltage V... LED Since the voltage V is fixed and known, only the cathode voltage needs to be measured. cathode This allows us to determine the forward voltage drop V of the LED. F =V LED -V cathode The forward voltage drop V through the LED F With junction temperature T j The linear relationship can be obtained by measuring the cathode voltage V during the display process. cathode To deduce the current junction temperature T j Then, based on the "junction temperature-brightness decay" characteristic of LEDs, it is possible to compensate for the brightness decay of LEDs.

[0017] Compared with existing technologies, this invention utilizes the PN junction of the LED itself in the constant current source driving architecture as a temperature sensor during the measurement and calculation process, by detecting the cathode voltage V. cathode Obtain positive pressure drop V F Therefore, the calculated result can directly represent the junction temperature of the LED itself, eliminating the temperature difference in the indirect temperature measurement method in the existing technology, making the measurement result more timely and accurate, and ensuring that the brightness of the whole screen remains consistent after brightness compensation.

[0018] Preferably, in the calculation step, a preset calibration coefficient K is called, based on the current forward pressure drop. Calculate the current junction temperature of the Mini-LED. , ;in Indicates standard temperature. This represents the forward voltage drop of a Mini-LED at standard temperature.

[0019] Preferably, with a preset calibration coefficient K, a constant test current I is applied to the Mini-LED under constant temperature conditions. sense Record different temperature points T j Forward voltage drop of Mini-LED The slope k and standard temperature for each Mini-LED were calculated. forward voltage drop Then according to the formula The calibration coefficient K is obtained. This method can produce an accurate calibration coefficient, thereby ensuring the accuracy of the measurement results and the accuracy of brightness compensation.

[0020] Preferably, the detection step is performed during the scanning interval of each frame of the image, and then the constant current source chip is adjusted according to the new current value during the display period of the next frame. This solution drives the Mini-LED. It ensures normal operation of the entire screen.

[0021] Preferably, in the compensation step, compensation is performed by adjusting the current amplitude, wherein the current value... Since the brightness of a Mini-LED is approximately proportional to the current within its rated range, this solution uses current amplitude adjustment to offset the brightness decay caused by temperature increases, making it simple to operate.

[0022] Preferably, in the detection step, the cathode voltage V of each Mini-LED channel is simultaneously measured during the scanning interval of each frame image. cathode This solution can detect the independent junction temperature of all Mini-LEDs, thereby enabling temperature management and brightness compensation at the pixel level.

[0023] Preferably, in the compensation step, when the calculated compensation current... Greater than the preset maximum allowable drive current At the same time, a global brightness coordination mechanism is adopted to match the brightness of the entire area with the currently hottest Mini-LED. This global brightness coordination mechanism can ensure the overall brightness uniformity of the entire screen, while also avoiding overload of individual Mini-LEDs, thereby improving the lifespan of Mini-LEDs.

[0024] Preferably, when the global brightness coordination mechanism is activated, the driving current of other Mini-LEDs in the same display zone or adjacent areas is reduced proportionally so that the brightness of the entire area matches that of the hottest Mini-LED.

[0025] Preferably, in the detection step, one group of Mini-LED channels is detected within the scanning interval of each frame, and a full-screen scan is completed after the scanning interval of N frames. Considering that tens of thousands of LEDs are typically arranged in the full screen, it is difficult to perform temperature detection and brightness compensation operations for all LEDs within the scanning interval of each frame. Furthermore, shortening the sampling time would lead to a decrease in the forward voltage drop V. F The measurement results are inaccurate because the LED junction temperature is not stable. Furthermore, since the rate of change of LED junction temperature is much slower than the frame period, this solution utilizes the inherent image frame gap in the display driver system to achieve intermittent temperature detection without affecting normal display. This reduces the number of channels that need to be detected per frame to 1 / N of the original, thus allowing sufficient time for current stabilization and high-precision sampling by the digital-to-analog converter, while also not affecting the human eye's perception of brightness changes.

[0026] Secondly, this invention also discloses a Mini-LED temperature detection and brightness compensation system based on forward voltage drop, which uses any of the aforementioned Mini-LED temperature detection and brightness compensation methods based on forward voltage drop to perform brightness compensation on Mini-LEDs. The system includes a constant current source driver chip, which comprises a constant current source module with multiple independent channels and a voltage detection module integrating an analog-to-digital converter on each of the multiple independent channels. The output terminal of each channel of the constant current source module is connected to the cathode of the corresponding Mini-LED to provide a programmable constant driving current to the Mini-LED. The voltage detection module is used to measure the voltage V between the Mini-LED cathode and ground during the detection period. cathode。

[0027] The present invention has the following beneficial effects:

[0028] 1. Direct junction temperature detection based on LED forward voltage drop:

[0029] Utilizing the forward voltage drop of the PN junction within the Mini-LED chip itself With junction temperature The linear negative correlation physical characteristic allows each LED to simultaneously function as a light-emitting element and a temperature sensor, enabling direct, online measurement of the junction temperature and avoiding the temperature measurement errors caused by the thermal conduction hysteresis of traditional thermistors.

[0030] 2. Seamless integration with constant current source drive architecture:

[0031] For the common anode-constant current source driving architecture widely used in Mini-LED display systems, where the LED anode is fixed and the cathode is connected to the constant current source chip channel, a method is proposed to measure the cathode voltage. And calculate Obtaining positive pressure drop This can be achieved without modifying the existing hardware structure; simply integrating the voltage detection function into the constant current source chip is sufficient.

[0032] 3. High-resolution temperature sensing:

[0033] By using the voltage detection module inside the constant current source chip, the cathode voltage of each Mini-LED channel can be measured simultaneously during the frame interval, thereby enabling independent junction temperature monitoring of all Mini-LEDs.

[0034] 4. Closed-loop brightness compensation based on junction temperature

[0035] Based on the real-time detected junction temperature value and combined with the pre-stored "junction temperature-brightness decay" characteristic curve, the brightness loss of each LED due to temperature rise is dynamically calculated, and real-time compensation is performed by adjusting the drive current setting value of the constant current source chip to ensure that the brightness of the entire screen remains uniform.

[0036] Furthermore, while existing technologies have corresponding applications, they are for LED lighting / general-purpose driver circuits. Mini-LED arrays, containing tens of thousands of individual LED chips, have fundamentally different requirements for temperature detection resolution, timeliness, and hardware integration. The voltage detection module in this patent integrates analog-to-digital converters on multiple independent channels of the constant current source chip, enabling independent junction temperature monitoring of all Mini-LEDs. This hardware architecture possesses specific technical adaptability and irreplaceability for Mini-LED display systems. Attached Figure Description

[0038] Figure 1 The existing technology uses a Mini-LED backplane structure with a thermistor;

[0039] Figure 2 The structural block diagram of the constant current source driving architecture in Embodiment 1 of the present invention, which describes a method and system for temperature detection and brightness compensation of Mini-LED based on forward voltage drop;

[0040] Figure 3 This is a basic operation flowchart of the system in Embodiment 1 of the present invention, which describes a method and system for Mini-LED temperature detection and brightness compensation based on forward voltage drop.

[0041] Figure 4 This is a schematic diagram illustrating the relative brightness-temperature characteristics of the junction temperature-brightness decay relationship data. Detailed Implementation

[0043] The following detailed description illustrates the specific implementation method:

[0044] 1. Definition

[0045] Forward voltage drop: The forward voltage drop (Vf) of an LED refers to the voltage required across the LED when it is forward-biased and emitting light. This value is not fixed.

[0046] Junction temperature: Junction temperature refers to the temperature of the PN junction region inside the semiconductor element when the LED is working. Usually, the overall temperature of the chip is regarded as the junction temperature.

[0047] A constant current source, also known as a current source or steady current source, is a power device that can output a stable current. Its core function is to dynamically adjust the power supply state through feedback control so that the output current remains constant regardless of changes in load or environment.

[0048] PN junction: refers to the interface structure formed by the close contact between P-type semiconductors and N-type semiconductors.

[0049] Current amplitude: refers to the maximum instantaneous value reached by alternating current within one cycle.

[0050] Frame period: refers to the time required to completely refresh one frame of an image.

[0051] 2. The example is shown below:

[0052] Example 1

[0053] The basics are as follows: Figures 2-4 As shown: A method for temperature detection and brightness compensation of Mini-LEDs based on forward voltage drop, implemented in a constant current source driving architecture, includes the following steps:

[0054] Testing steps: The testing is performed during the scanning interval of each image frame, specifically the time between the end of one image frame and the start of the next. A predetermined test current I is applied to the Mini-LED. sense Simultaneous acquisition of the Mini-LED cathode voltage V for each Mini-LED channel cathode The forward voltage drop of the Mini-LED was calculated. , V LED This refers to the voltage at the common power supply terminal connected to the anode of the Mini-LED.

[0055] Calculation steps: Call the preset calibration coefficient K, based on the current forward pressure drop. Calculate the current junction temperature of the Mini-LED. , ;in Indicates standard temperature. This represents the forward voltage drop of a Mini-LED at standard temperature.

[0056] In the preset calibration system, a constant test current I is applied to the Mini-LED under a constant temperature environment. sense Record different temperature points T j Forward voltage drop of Mini-LED The slope k and standard temperature for each Mini-LED were calculated. forward voltage drop Then according to the formula The calibration coefficient K is then obtained.

[0057] According to the junction temperature The brightness decay ratio of Mini-LEDs is matched from the preset "junction temperature-brightness decay" relationship data. ;

[0058] Compensation steps: Based on the calculated brightness attenuation ratio Set the current value that will restore the Mini-LED brightness to the target value. Compensation is achieved by adjusting the current amplitude, therefore the current value For linear compensation, the greater the brightness attenuation ratio, the greater the calculated compensation current value; the constant current source chip adjusts according to the new current value. Drive Mini-LED.

[0059] When the calculated compensation current Greater than the preset maximum allowable drive current At the same time, a global brightness coordination mechanism is adopted to reduce the driving current of other Mini-LEDs in the same display zone or adjacent areas proportionally, so that the brightness of the whole area matches the current hottest Mini-LED.

[0060] This embodiment also discloses a Mini-LED temperature detection and brightness compensation system based on forward voltage drop, including a constant current source driver chip and a control and compensation module. The control and compensation module is the main control chip's data logic unit, further including a storage unit, a junction temperature calculation unit, and a brightness compensation unit.

[0061] Specifically, the storage unit stores the pre-calibrated calibration coefficient K and the "junction temperature-brightness decay" relationship data. Typically, this data can be obtained from the LED datasheet or through actual measurements. Currently, the brightness decay of Mini-LEDs is non-linear.

[0062] The constant current source driver chip includes a constant current source module with multiple independent channels and a voltage detection module with an integrated analog-to-digital converter on each of the multiple independent channels. The output of each channel of the constant current source module is connected to the cathode of the corresponding Mini-LED to provide a programmable constant drive current to the Mini-LED. The voltage detection module is used to measure the voltage V between the Mini-LED cathode and ground during the detection period. cathode ;

[0063] Junction temperature calculation unit: used to receive the acquired cathode voltage, calculate the current forward voltage drop in combination with the known anode voltage, and then match the current junction temperature;

[0064] Brightness compensation unit: It is used to match the brightness decay amount from the "junction temperature-brightness decay" relationship data according to the current junction temperature, calculate the incremental drive current that needs to be compensated, and send the compensation command to the constant current source driver chip.

[0065] The Mini-LED temperature detection and brightness compensation system based on forward voltage drop in this implementation is suitable for Mini-LED arrays composed of multiple Mini-LED chips, where the anodes of all Mini-LEDs are connected to the same common power supply terminal V. LED Common power supply terminal V LED A stable anode voltage is provided for all Mini-LEDs. The cathode of each Mini-LED is connected to the corresponding channel pin of the constant current source driver chip via a trace. The cathode voltage is sampled by an internal analog-to-digital converter connected to the chip via an internal analog multiplexer. The control and compensation module communicates with the constant current source driver chip via serial interfaces such as I2C / SPI, sending current setting commands and receiving detection data.

[0066] The specific implementation process is as follows: The temperature detection and brightness compensation method in this invention includes three stages: pre-calibration stage, online detection stage, and compensation calculation and execution stage.

[0067] Phase 1: Pre-calibration phase, performed before shipment.

[0068] S1-1, Establish - Relationship: A constant, minute test current is applied to the Mini-LED in a constant temperature environment. Record different temperature points Cathode voltage of LED at temperatures such as 0℃, 25℃, 50℃, and 80℃. ,calculate = - In this embodiment, a constant, minute test current is applied to the Mini-LED under a constant temperature environment. The current is 50μA, which should ensure that the LED emits no light or emits only a small amount of light to avoid self-heating. Then, the cathode voltage of the LED is recorded at temperature points of 0℃, 25℃, 50℃, 80℃, and 100℃. The measured data are shown in Table 1.

[0069] Table 1

[0070] 0 2.850 0 25 2.798 -52 50 2.745 -105 80 2.679 -171 100 2.632 -218

[0071] The relative change This refers to the change in the positive pressure drop at a given temperature relative to the positive pressure drop at 0°C.

[0072] S1-2. Perform linear fitting on the data to obtain the slope K and the value at standard temperature for each Mini-LED. The obtained calibration coefficient K is stored in the storage unit. The temperature coefficient is calculated based on the following formula. The slope K is the temperature coefficient, typically ranging from -2mV / ℃ to -2.5mV / ℃, with the standard temperature set at 25℃. In this embodiment, after calculation based on the recorded data, K = -2.18mV / ℃ is obtained.

[0073] Phase Two: Online Testing Phase, conducted during normal display.

[0074] A brief "temperature detection period" is inserted between each frame of the image scan. The specific steps are as follows:

[0075] S2-1, Switching Detection Mode: During the time between the end of one frame and the start of the next, the control and compensation module sends a command to the constant current source driver chip via the serial interface, causing it to temporarily shut off the current Mini-LED's normal drive current and switch to the test current mode, outputting a preset small constant current I. sense .

[0076] S2-2, Voltage Acquisition: The voltage detection module quickly acquires the cathode voltage V after the current stabilizes via an ADC. cathode The digital value is then returned to the control and compensation module.

[0077] S2-3, Data Conversion: Calculation by the Control and Compensation Module = - In this embodiment, in the driving current At 20mA, the anode voltage is known. =3.3V, measured cathode voltage =0.569V.

[0078] Phase 3: Compensation Calculation and Implementation Phase.

[0079] S3-1, Junction Temperature Calculation: The junction temperature calculation unit calculates the junction temperature based on the currently measured forward voltage drop. Calculate =2.731V. Using the pre-stored calibration coefficient K, the current junction temperature of the Mini-LED is calculated. , ≈55.7℃; of which Indicates standard temperature. This represents the forward voltage drop of a Mini-LED at standard temperature.

[0080] S3-2, Brightness Attenuation Calculation: Based on the "junction temperature-brightness attenuation" relationship data of this Mini-LED model, the brightness attenuation ratio relative to the standard junction temperature is calculated. For example... Figure 4As shown, the relative brightness at 55.7℃ is 91.95%, indicating a decrease in brightness. =9.05%.

[0081] S3-3. To compensate for the brightness decay caused by increased temperature, the driving current needs to be increased. Since the brightness of a Mini-LED is approximately proportional to the current within its rated range, the brightness compensation unit calculates the required increase in current. In this embodiment, current amplitude adjustment is used, so the target current... In this embodiment, when the brightness decreases... When the current is 9.05%, then the target current is #imgpt76#

[0082] S3-4, Compensation Execution: The control and compensation module writes the calculated compensation value, i.e., the target current, into the corresponding channel register of the constant current source driver chip via a serial interface. The constant current source chip then drives the Mini-LED according to the new setting value during the next display frame, restoring the brightness to the target value.

[0083] When the calculated compensation current (#imgpt77#) exceeds the preset maximum allowable driving current (#imgpt78#), a global brightness coordination mechanism is employed. This mechanism proportionally reduces the driving current of other Mini-LEDs within the same display zone or adjacent areas, ensuring the overall brightness matches that of the hottest Mini-LED. This is because the hottest LED experiences the greatest brightness decay and reaches its lowest brightness. Matching other Mini-LEDs within the same display zone or adjacent areas with it effectively reduces the overall brightness. As the brightness decreases, the current and screen temperature gradually decrease as well. Since the compensation for brightness decay after the global brightness reduction is not significant, a linear compensation method using current amplitude adjustment is sufficient, eliminating the need for complex calculations and ensuring rapid brightness compensation.

[0084] In this embodiment, through this closed-loop control of "detection-calculation-compensation", the system can respond to any local temperature change in real time and eliminate brightness differences caused by uneven temperature distribution.

[0085] Furthermore, experiments have shown that once the junction temperature reaches 100°C, the change is no longer linear. Therefore, once the calculated junction temperature exceeds 100°C, all currents are reduced and brightness compensation is no longer performed.

[0086] Example 2

[0087] Unlike the method of simultaneously measuring the Mini-LED channels in Example 1, this example uses group measurement, that is, within the scanning gap of each frame image, one group of Mini-LED channels is detected, and a full-screen scan is completed after the scanning gap of N frames images.

[0088] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for temperature detection and brightness compensation of Mini-LEDs based on forward voltage drop, characterized in that: Based on a constant current source driver architecture, the following steps are included: Testing steps: Apply a predetermined test current I to the Mini-LED. sense Collect Mini-LED cathode voltage V cathode The forward voltage drop of the Mini-LED was calculated. , V LED This refers to the voltage at the common power supply terminal connected to the anode of the Mini-LED. Calculation steps: Based on the current forward pressure drop Calculate the current junction temperature of the Mini-LED. According to the junction temperature The brightness decay ratio of Mini-LEDs is matched from the preset "junction temperature-brightness decay" relationship data. ; Compensation steps: Based on the calculated brightness attenuation ratio Set the current value that will restore the Mini-LED brightness to the target value. The constant current source chip is adjusted according to the new current value. Drive Mini-LED.

2. The method for Mini-LED temperature detection and brightness compensation based on forward voltage drop according to claim 1, characterized in that: In the calculation step, a preset calibration coefficient K is invoked, based on the current forward pressure drop. Calculate the current junction temperature of the Mini-LED. , ;in Indicates standard temperature. This represents the forward voltage drop of a Mini-LED at standard temperature.

3. The method for Mini-LED temperature detection and brightness compensation based on forward voltage drop according to claim 2, characterized in that: With the calibration coefficient K preset, a constant test current I is applied to the Mini-LED under constant temperature conditions. sense Record different temperature points T j Forward voltage drop of Mini-LED The slope k and standard temperature for each Mini-LED were calculated. forward voltage drop Then according to the formula The calibration coefficient K is then obtained.

4. The method for Mini-LED temperature detection and brightness compensation based on forward voltage drop according to any one of claims 1-3, characterized in that: The detection step is performed during the scanning interval of each frame of the image, and then the constant current source chip operates according to the new current value during the display period of the next frame. Drive Mini-LED.

5. The method for Mini-LED temperature detection and brightness compensation based on forward voltage drop according to claim 4, characterized in that: In the compensation step, compensation is performed by adjusting the current amplitude, wherein the current value... .

6. The method for Mini-LED temperature detection and brightness compensation based on forward voltage drop according to claim 5, characterized in that: In the detection step, the cathode voltage V of each Mini-LED channel is simultaneously measured during the scanning interval of each frame image. cathode。 7. The method for Mini-LED temperature detection and brightness compensation based on forward voltage drop according to claim 6, characterized in that: In the compensation step, when the calculated compensation current Greater than the preset maximum allowable drive current At the same time, a global brightness coordination mechanism is adopted to match the brightness of the entire area with the currently hottest Mini-LED.

8. The method for Mini-LED temperature detection and brightness compensation based on forward voltage drop according to claim 7, characterized in that: When the global brightness coordination mechanism is activated, the driving current of other Mini-LEDs in the same display zone or adjacent areas is reduced proportionally to match the brightness of the entire area with the currently hottest Mini-LED.

9. The method for Mini-LED temperature detection and brightness compensation based on forward voltage drop according to claim 4, characterized in that: In the detection step, one group of Mini-LED channels is detected within the scanning interval of each frame image, and a full-screen scan is completed after the scanning interval of N frames images.

10. A Mini-LED temperature detection and brightness compensation system based on forward voltage drop, characterized in that: The method for Mini-LED temperature detection and brightness compensation based on forward voltage drop, as described in any one of claims 1-9, is used to compensate the brightness of a Mini-LED. It includes a constant current source driver chip, which comprises a constant current source module with multiple independent channels and a voltage detection module integrating an analog-to-digital converter on each of the multiple independent channels. The output terminal of each channel of the constant current source module is connected to the cathode of the corresponding Mini-LED to provide a programmable constant driving current to the Mini-LED. The voltage detection module is used to measure the voltage V between the Mini-LED cathode and ground during the detection period. cathode .

Images