Temperature adaptive color correction system and method for dlp projection devices

Abstract

This invention relates to the field of projection equipment technology, specifically providing a temperature-adaptive color correction system and method for DLP projection equipment. The system includes an optical temperature monitoring module comprising four temperature sensors for temperature monitoring; a main control processing module using a microcontroller as the core processor, comprising four ADC channels for color compensation calculation; and an execution drive module comprising a first subunit (RGB laser driver circuit connected to the microcontroller), a second subunit (multi-zone fan control circuit), and a third subunit (power management circuit) for heat dissipation control. The microcontroller is connected to an EEPROM memory chip via an I²C bus. A heat dissipation structure module includes four axial fans and corresponding air ducts for each fan. Multiple temperature sensors are placed on key optical components such as the RGB laser and DMD chip to monitor the actual operating temperature of each area in real time.

Description

Technical Field

[0001] This invention relates to the field of projection equipment technology, and more particularly to a temperature-adaptive color correction system and method for DLP projection equipment. Background Technology

[0002] Existing technologies employ single-point temperature monitoring and uniform brightness adjustment, which cannot cope with the different temperature characteristics of RGB three-color lasers, resulting in significant color shift in the projected image as the working time increases.

[0003] Patent document publication number CN107450668A discloses a projector overheat protection scheme based on single-point temperature detection. This patent monitors ambient temperature or local hotspot temperature by installing a single temperature sensor inside the projector, typically near the cooling fan or axial fan, or on the surface of the main chip. The control logic is a simple threshold judgment: when the detected temperature exceeds a safe threshold, the system will uniformly reduce the light source brightness, increase the fan speed, or directly shut down for protection if the temperature continues to exceed the limit. However, this patent still has some shortcomings: 1. It cannot solve the color deviation problem. Since the heating degree and efficiency change curves of the RGB three-color lasers are different, the traditional solution reduces the brightness of the three colors simultaneously. Although the overall brightness decreases, the ratio of the three colors is destroyed, and the color is still inaccurate. Users will still perceive the problem of "yellow or blue color". 2. Insufficient measurement accuracy. Single-point monitoring cannot reflect the temperature differences of different light source areas. The sensor is usually far from the laser, resulting in a large response delay. The measured value can deviate from the actual operating temperature by 5-10℃. 3. The control method lacks precision. It adopts a "one-size-fits-all" strategy, which reduces the overall brightness when the temperature exceeds the standard, and cannot compensate for specific color channels individually, resulting in the screen suddenly darkening and seriously affecting the viewing experience. Summary of the Invention

[0004] To address the issue of color inaccuracy caused by temperature variations in existing DLP projection technology, this invention provides a temperature-adaptive color correction system and method for DLP projection devices.

[0005] The technical solution adopted by this invention to solve its technical problem is: a temperature-adaptive color correction system and method for DLP projection devices, including an optical temperature monitoring module, a main control processing module, an execution drive module, and a heat dissipation structure module. The optical temperature monitoring module includes four temperature sensors installed inside the optical engine of the DLP projection device. The optical engine includes an RGB laser. The optical temperature monitoring module is used for temperature monitoring. The main control processing module uses a microcontroller as the core processor and is installed on the main control board of the DLP projection device. The microcontroller includes four ADC channels, and the four ADC channels of the microcontroller are respectively connected to the signal input terminals of the four temperature sensors. The main control processing module is used for color compensation calculation; the execution drive module includes three sub-units, wherein the first sub-unit is an RGB laser driver circuit and is connected to the microcontroller, the second sub-unit is a multi-zone fan control circuit, and the third sub-unit is a power management circuit. The third sub-unit is used to provide stable 3.3V and 5V voltages for the entire system. The execution drive module is used for heat dissipation control; the microcontroller is connected to an EEPROM memory chip via an I²C bus. The EEPROM memory chip is used for data storage and learning; the heat dissipation structure module includes four axial fans and corresponding air ducts for the axial fans. The power line of each axial fan is connected to the second sub-unit.

[0006] Preferably, the four temperature sensors are sensor S1, sensor S2, sensor S3, and sensor S4. The RGB laser consists of a red laser, a green laser, and a blue laser. Sensor S1 is directly attached to the copper heat sink substrate of the red laser using thermally conductive silicone, 3-5mm away from the laser emission point. Sensor S2 is directly attached to the heat sink substrate of the green laser using thermally conductive silicone. Sensor S3 is mounted on the heat sink substrate of the blue laser. Sensor S4 is fixed to the center of the aluminum heat sink fins below the DMD chip using a micro-bracket. The microcontroller is an S32K144 microcontroller. The main control board has four ADC interface sockets connected to the four ADC channels of the microcontroller. The signal lines of the four temperature sensors are connected to the four ADC interface sockets on the main control board via four-core shielded cables, each less than 15cm in length.

[0007] Preferably, the microcontroller also includes three FTM timers and four GPIO pins. The outputs of the three FTM timers are connected to the RGB laser driver circuit, and the four GPIO pins are connected to the multi-zone fan control circuit.

[0008] Preferably, the RGB laser driving circuit of the first sub-unit includes three independent constant current PWM driving chips. The PWM input terminal of each constant current PWM driving chip is connected to the corresponding FTM timer output terminal of the microcontroller, and the current output terminal of each constant current PWM driving chip is connected to the corresponding color RGB laser through copper foil traces. The multi-region fan control circuit of the second sub-unit includes four MOSFET switching transistors that are respectively connected to the axial fan control line. The gate of each MOSFET switching transistor is connected to the four GPIO pins of the microcontroller, and the drain is connected to the positive power supply terminal of the corresponding axial fan.

[0009] Preferably, the four axial fans are fan F1, fan F2, fan F3 and fan F4. Fan F1 is installed on the air intake side of the red laser heat sink, 10mm away from the heat sink fins; fan F2 is installed in the same position on the green laser heat sink; fan F3 is installed at the position of the blue laser heat sink; and fan F4 is installed on the air outlet side of the DMD chip heat sink.

[0010] Preferably, the temperature sensor is an NTC thermistor sensor, and four NTC thermistors can convert temperature changes into resistance changes.

[0011] The temperature-adaptive color correction method for DLP projection devices, including the temperature-adaptive color correction system for DLP projection devices as described above, further includes the following steps: Step 1: System initialization process. After the projection device is powered on, the power management circuit generates stable 3.3V and 5V voltages. The microcontroller is powered on and reset, first executing the hardware self-test program. It reads the initial values ​​of the four temperature sensors through the ADC to determine if the temperature sensors are working properly; it reads the device serial number and calibration parameters from the EEPROM storage chip through the I²C bus; it initializes the FTM timer to generate a PWM test signal at a reference frequency to verify the function of the laser drive circuit; and so on. The axial fan is controlled to rotate at full speed for 3 seconds via GPIO to remove accumulated dust and test fan performance. After self-test, the system enters standby mode, waiting for the user's power-on command. Step 2: Temperature data acquisition process. After the user turns on the projector, the optical temperature monitoring module starts working. The thermistor in each temperature sensor changes its resistance with temperature, causing the voltage divider circuit to change its output voltage. These analog voltage signals are transmitted to the input pin of the microcontroller's ADC channel through PCB traces. The microcontroller's ADC module samples the four ADC channels in turn at 100μs intervals, converting the analog voltage into a 12-bit digital value, where 0-4095 corresponds to 0-3.3V, during sampling, a hardware anti-aliasing filter eliminates high-frequency noise, and a sample-and-hold circuit ensures the time synchronization of sampling for the four ADC channels. The converted digital value is stored in the microcontroller's DMA buffer for subsequent processing. Step 3, real-time color compensation process: the microcontroller reads the latest temperature data from the DMA buffer every 10ms and performs compensation calculations. The physical calculation process is as follows: first, the raw ADC value is converted into the actual temperature value using the formula T=(4095 / ADC_raw-1)×R_series / β, where β is the constant B value of the thermistor; then, the current temperature of each laser is calculated relative to 25... The difference ΔT between the reference temperature and the temperature is calculated. Then, the new PWM duty cycle is calculated using the compensation formula PWM_new=PWM_base×[1 / (1+α×ΔT)], where α is the temperature attenuation coefficient of each laser. Finally, the calculation result is written to the comparison register of the FTM timer, and the hardware automatically updates the PWM output waveform. This process is completed within 10ms to ensure the real-time performance of the compensation. Step four: Adaptive heat dissipation control process. The system dynamically adjusts the heat dissipation strategy according to the temperature monitoring results. The physical control process is as follows: the microcontroller calculates the highest temperature T_max and the maximum temperature difference ΔT_max of the four monitoring points. If T_max<6 At 0℃, the GPIO outputs a PWM signal with a 50% duty cycle, and the fan runs at a medium speed. If 60℃ ≤ T_max < 70℃, the PWM duty cycle of the four GPIOs is adjusted according to the temperature differences in each area, and the fan speed in the high-temperature area is increased to 70-80%. If T_max ≥ 70℃, all GPIOs output a 100% duty cycle, and the fan runs at full speed. At the same time, if ΔT_max > 8℃, the thermal balance mode is activated, which promotes the even distribution of heat among different areas by adjusting the angle of the air duct baffle and the fan speed ratio. Step 5: Data learning and optimization process. Before each shutdown, the system performs data recording. The parameter optimization process involves the following physical steps: The microcontroller packages data such as the temperature change curve, compensation adjustment records, and user color settings preferences during the current operation. This data is then written to a designated storage area of ​​the EEPROM via the I²C bus, using page programming with 256 bytes written at a time. Simultaneously, historical data records are read and the compensation effect is analyzed. If the compensation error in a certain temperature range is found to be persistently large, the compensation coefficient α for that range is automatically adjusted. The optimized new parameters are then written to another storage area of ​​the EEPROM as the initial parameters for the next power-on. This process is completed within 5 seconds before power-off to ensure data integrity.

[0012] Preferably, in step two, the temperature data acquisition process is implemented through a multi-channel temperature synchronous acquisition program. Specifically, the multi-channel temperature synchronous acquisition program is completed by the interrupt service routine and the DMA controller. The timer interrupt is triggered once every 100μs. The sequential scan conversion of the ADC is started in the interrupt service routine. After the ADC completes the conversion of four channels, the data is directly transferred to the memory buffer through the DMA request. The program implements a circular buffer and a double buffering mechanism to ensure that the data is continuous and not lost. At the same time, the program monitors the validity of the data of each channel in real time. If an abnormal sensor data is found, the fault is automatically marked and the backup compensation strategy is activated.

[0013] In step three, the color compensation process is implemented through a temperature-color compensation algorithm. This algorithm executes every 10ms in the main loop. The program first retrieves the latest four temperature values ​​from the circular buffer, converts the original ADC values ​​to Celsius using a lookup table, and then uses a floating-point arithmetic library to calculate the temperature compensation coefficient for each laser. The calculation process includes exponential smoothing filtering to avoid sudden changes in PWM output. The program also implements boundary protection logic to ensure that the compensated PWM value does not exceed the safe operating range of the laser. For sudden rapid temperature changes, the program uses a predictive extrapolation algorithm to adjust the compensation amount in advance and reduce response delay.

[0014] Preferably, in step four, the adaptive heat dissipation control process is implemented through a three-level temperature management state machine program. This program implements a finite state machine to manage three working states of the system. The state machine performs state transitions based on the values ​​and trends of T_max and ΔT_max. In the normal state, the program only performs basic color compensation and conventional heat dissipation. In the warning state, the program starts enhanced monitoring, shortens the temperature acquisition interval to 50μs, and calculates the temperature change trend to predict whether it is necessary to enter the protection state. In the protection state, the program performs gradual brightness adjustment, reducing the brightness by 1-2% per second, and monitors whether the temperature drops. The state transition process records detailed logs for subsequent fault analysis and parameter optimization.

[0015] Preferably, in step five, the data learning and optimization process is implemented through an adaptive learning algorithm program. This program runs when the system is idle, analyzes historical running data, reads the temperature-compensation records of the most recent 100 runs from the EEPROM, uses the least squares method to fit the actual temperature-efficiency curve of each laser, compares it with the theoretical curve to obtain the correction coefficient, and the learning algorithm also considers the influence of ambient temperature and running time to establish a multi-dimensional compensation model. When enough data is accumulated, the program automatically generates an optimized compensation parameter table to replace the original fixed parameters.

[0016] It also includes a user interface and exception handling program. The user interface and exception handling program provide a user configuration interface and exception handling mechanism. Users can adjust color preferences through the projection menu. The program converts the user settings into the bias amount of the compensation parameters. When a hardware failure is detected, the program starts a degraded operation mode: if a temperature sensor fails, it uses data interpolation from adjacent sensors to replace it; if a fan fails, it increases the speed of other fans to compensate for the heat dissipation capacity; if the laser temperature continues to be abnormal, it gradually reduces the brightness until it is safely shut down. All abnormal events are recorded in EEPROM and can be read and analyzed through the debugging interface.

[0017] The beneficial effects of this invention are as follows: by arranging multiple temperature sensors at key optical components such as RGB lasers (red, green, and blue) and DMD chips, accurate real-time monitoring of the actual operating temperature of each area inside the projection device is achieved, solving the problems of large response delay and high measurement deviation in traditional single-point monitoring; based on a temperature-color compensation mathematical model, the system can independently adjust the brightness output of the three colors according to the real-time temperature of each laser, fundamentally suppressing color drift caused by temperature changes and ensuring long-term stable and accurate image colors; through an adaptive learning algorithm, the system can continuously optimize the compensation coefficient during long-term operation of the device, gradually improving the compensation accuracy and possessing self-evolution capabilities; combined with multi-area intelligent heat dissipation control, the system can dynamically adjust the fan speed and thermal balance strategy, reducing energy consumption and noise while ensuring heat dissipation efficiency and extending the service life of key components; the overall solution significantly improves the color stability, environmental adaptability, and user experience of the projection device, and has high reliability, low maintenance costs, and broad application prospects. Attached Figure Description

[0018] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0019] Figure 1 This is a diagram of the temperature-adaptive color correction system architecture for the DLP projection device of this invention.

[0020] Figure 2 This is a flowchart of the temperature-adaptive color correction method for DLP projection devices according to the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] like Figure 1 As shown, the present invention provides an embodiment of a temperature-adaptive color correction system for a DLP projection device, including an optical temperature monitoring module, a main control processing module, an execution drive module, and a heat dissipation structure module. The optical temperature monitoring module includes four temperature sensors installed inside the optical engine of the DLP projection device. The optical engine includes an RGB laser. The optical temperature monitoring module is used for temperature monitoring.

[0024] The main control processing module uses a microcontroller as its core processor and is installed on the main control board of the DLP projection device. The microcontroller includes four ADC channels, which are respectively connected to the signal input terminals of the four temperature sensors. The main control processing module is used for color compensation calculation. This module uses a temperature-color compensation algorithm to calculate the temperature changes of each laser in real time and independently adjust the PWM drive signal to ensure that the brightness ratio of the three colors is constant, thus ensuring the long-term stability of color output from the algorithm level.

[0025] The execution drive module comprises three subunits: the first subunit is an RGB laser driver circuit connected to the microcontroller; the second subunit is a multi-zone fan control circuit; and the third subunit is a power management circuit. The third subunit provides stable 3.3V and 5V voltages to the entire system. The execution drive module is used for heat dissipation control, enabling fine-tuning of the laser output power, independent speed control of each zone's fans, and stable management of the system's power supply. This module efficiently translates control commands into physical execution, ensuring rapid response and accurate execution of color compensation and heat dissipation strategies.

[0026] The microcontroller is connected to an EEPROM memory chip via an I²C bus. The EEPROM memory chip is used for data storage and learning. The heat dissipation structure module includes four axial fans and corresponding air ducts for the axial fans. The power line of each axial fan is connected to the second sub-unit to achieve directional and zoned heat dissipation for the RGB laser and DMD chip. Combined with the dynamic adjustment strategy of the main control processing module, this module can achieve efficient heat dissipation and low-noise operation under different working conditions, significantly improving the thermal management capability of the system and the service life of key components.

[0027] The optical temperature monitoring module, main control processing module, execution drive module, and heat dissipation structure module work together to build a temperature-adaptive color correction system that integrates "precise monitoring, intelligent calculation, efficient execution, and structural optimization." This system fundamentally solves the color drift problem caused by temperature changes in DLP projection devices, achieving high stability of projected image colors and high reliability of device operation.

[0028] The four temperature sensors are designated as sensor S1, sensor S2, sensor S3, and sensor S4. The RGB laser consists of a red laser, a green laser, and a blue laser. Sensor S1 is directly attached to the copper heat sink substrate of the red laser using thermally conductive silicone, 3-5 mm away from the laser emission point. Sensor S2 is directly attached to the heat sink substrate of the green laser using thermally conductive silicone. Sensor S3 is mounted on the heat sink substrate of the blue laser. Sensor S4 is fixed to the center of the aluminum heat sink fins below the DMD chip using a miniature bracket.

[0029] The microcontroller is an S32K144 microcontroller, which has real-time data processing and control capabilities. The main control board is equipped with four ADC interface sockets that are connected to the four ADC channels of the microcontroller. The signal lines of the four temperature sensors are respectively connected to the four ADC interface sockets on the main control board through four-core shielded cables. The length of the four-core shielded cables is less than 15cm.

[0030] The microcontroller also includes three FTM timers and four GPIO pins. The outputs of the three FTM timers are connected to the RGB laser driver circuit, and the four GPIO pins are connected to the multi-zone fan control circuit.

[0031] The RGB laser driving circuit of the first sub-unit includes three independent constant current PWM driving chips. The PWM input terminal of each constant current PWM driving chip is connected to the corresponding FTM timer output terminal of the microcontroller, and the current output terminal of each constant current PWM driving chip is connected to the corresponding color RGB laser through copper foil traces. The multi-zone fan control circuit of the second sub-unit includes four MOSFET switching transistors that are respectively connected to the axial fan control line. The gate of each MOSFET switching transistor is connected to the four GPIO pins of the microcontroller, and the drain is connected to the positive power supply terminal of the corresponding axial fan.

[0032] The four axial fans are fan F1, fan F2, fan F3 and fan F4. Fan F1 is installed on the air intake side of the red laser heat sink, 10mm away from the heat sink fins; fan F2 is installed in the same position on the green laser heat sink; fan F3 is installed at the position of the blue laser heat sink; and fan F4 is installed on the air outlet side of the DMD chip heat sink.

[0033] The temperature sensor uses an NTC thermistor sensor. Four NTC thermistors can convert temperature changes into resistance changes. The optical temperature monitoring module uses four high-precision NTC thermistors deployed in key heat source areas such as the RGB laser and DMD chip to achieve independent, real-time, and high-precision monitoring of the temperature at multiple points inside the projection device. This effectively overcomes the measurement blind spots and response lag problems of traditional single-point monitoring methods, providing a reliable data foundation for accurate color compensation.

[0034] Example 2 of the temperature-adaptive color correction system for DLP projection equipment differs from Example 1 in that the sensor is upgraded to a PT100 platinum resistance thermometer (±0.1℃), the sampling frequency is 1kHz, the compensation calculation is performed every 1ms, a fourth-order polynomial model is used, temperature and humidity environmental compensation is added, and the thermal coupling effect of the laser is considered. It is medically certified, supports the DICOM standard and HL7 protocol, and has special functions such as surgical locking, diagnostic recording, and remote calibration to meet the actual needs of medical imaging equipment.

[0035] Example 3 of the temperature-adaptive color correction system for DLP projection equipment differs from Example 1 in that: the sensor has IP65 protection, an operating temperature range of -20~50℃, and is shock-resistant. It automatically saves energy based on ambient brightness, reduces noise at night, and features anti-condensation standby. It integrates 4G remote monitoring, cloud data upload, anomaly alarms, and supports remote maintenance and upgrades to adapt to outdoor working environments. It achieves continuous operation for 4 hours with ΔE < 2.0, temperature response < 50ms, 30-40% power consumption reduction, 20-30% laser lifespan extension, and 40% improvement in compensation accuracy after 50 hours of learning. The system operates stably in environments ranging from 10-35℃ with an annual failure rate of < 1%.

[0036] Actual testing shows that the color deviation ΔE value after 4 hours of continuous operation has decreased from >5.0 in existing technologies to <2.0, and the color temperature fluctuation has been reduced from ±500K to ±100K, resulting in a fundamental improvement in color performance. Simultaneously, intelligent heat dissipation control reduces fan energy consumption by 30-40%, lowers the operating temperature of core components by 5-8℃, and is expected to extend the laser's lifespan by 20-30%. Users can obtain stable color performance without complex manual color calibration, ensuring a continuous viewing experience and significantly reducing equipment maintenance costs.

[0037] like Figure 2 As shown, the temperature-adaptive color correction method for a DLP projection device includes the temperature-adaptive color correction system for a DLP projection device as described above, and further includes the following steps:

[0038] Step 1: System Initialization Process. After the projection device is powered on, the power management circuit generates stable 3.3V and 5V voltages. The microcontroller is powered on and reset, first executing the hardware self-test program. It reads the initial values ​​of the four temperature sensors through the ADC to determine whether the temperature sensors are working properly; it reads the device serial number and calibration parameters from the EEPROM storage chip through the I²C bus; it initializes the FTM timer to generate a PWM test signal at the reference frequency to verify the function of the laser driver circuit; it controls the axial fan to rotate at full speed for 3 seconds through GPIO to remove dust and test the fan performance. After the self-test is completed, the system enters standby mode, waiting for the user's power-on command.

[0039] Step 2: Temperature Data Acquisition Process. After the user turns on the projector, the optical temperature monitoring module starts working. The thermistor in each temperature sensor changes its resistance with temperature, causing the voltage divider circuit to output a different voltage. These analog voltage signals are transmitted to the input pin of the microcontroller's ADC channel through PCB traces. The microcontroller's ADC module samples the four ADC channels in turn at 100μs intervals, converting the analog voltage into a 12-bit digital value, where 0-4095 corresponds to 0-3.3V. During the sampling process, a hardware anti-aliasing filter eliminates high-frequency noise, and a sample-and-hold circuit ensures the time synchronization of the four ADC channels. The converted digital value is stored in the microcontroller's DMA buffer for subsequent processing.

[0040] In step two, the temperature data acquisition process is implemented through a multi-channel temperature synchronous acquisition program. Specifically, the multi-channel temperature synchronous acquisition program is completed by the interrupt service routine and the DMA controller. The timer interrupt is triggered once every 100μs. The sequential scan conversion of the ADC is started in the interrupt service routine. After the ADC completes the conversion of four channels, the data is directly transferred to the memory buffer through the DMA request. The program implements a circular buffer and a double buffering mechanism to ensure that the data is continuous and not lost. At the same time, the program monitors the validity of the data of each channel in real time. If an abnormal sensor data is detected, the fault is automatically marked and the backup compensation strategy is activated. Specifically, when a temperature sensor, such as sensor S1, sensor S2, sensor S3 and sensor S4, is detected to have abnormal data (including signal exceeding the reasonable range, no change for a long time or sudden change exceeding the preset threshold), the system first marks the sensor as faulty and records the fault code to the EEPROM storage chip. Then, the system automatically switches to the corresponding compensation mode according to the location of the faulty sensor.

[0041] If the faulty sensor is the sensor corresponding to the RGB laser (sensor S1, sensor S2, sensor S3), the system will estimate the operating temperature of the current faulty laser based on the temperature change trend of the other laser sensors and the temperature coupling relationship model in the historical learning data. At the same time, the system temporarily uses the temperature data of the adjacent lasers as a reference and introduces a safety margin coefficient to ensure the continuity and safety of compensation.

[0042] If the faulty sensor is sensor S4 corresponding to the DMD chip, the system will estimate the DMD temperature based on parameters such as system runtime, current brightness level, and fan operating status, using the built-in thermal model, and appropriately increase heat dissipation redundancy to prevent overheating damage.

[0043] When a single sensor fails, the system will display a message on the user interface: "Color correction accuracy has decreased. Please repair it promptly." When two or more sensors fail, the system will automatically switch to a safety protection mode, gradually reducing brightness and limiting operating time until the device enters standby mode to ensure device safety.

[0044] Step 3: Real-time color compensation process. The microcontroller reads the latest temperature data from the DMA buffer every 10ms and performs compensation calculations. The physical calculation process is as follows: First, the raw ADC value is converted into the actual temperature value using the formula T=(4095 / ADC_raw-1)×R_series / β, where β is the constant B value of the thermistor; then, the difference ΔT between the current temperature of each laser and the 25℃ reference temperature is calculated; next, the new PWM duty cycle is calculated using the compensation formula PWM_new=PWM_base×[1 / (1+α×ΔT)], where α is the temperature attenuation coefficient of each laser; finally, the calculation results are written to the comparison register of the FTM timer, and the hardware automatically updates the PWM output waveform. This process is completed within 10ms to ensure the real-time performance of the compensation.

[0045] In step three, the color compensation process is implemented through a temperature-color compensation algorithm. This algorithm executes every 10ms in the main loop. The program first retrieves the latest four temperature values ​​from the circular buffer, converts the original ADC values ​​to Celsius using a lookup table, and then uses a floating-point arithmetic library to calculate the temperature compensation coefficient for each laser. The calculation process includes exponential smoothing filtering to avoid sudden changes in PWM output. The program also implements boundary protection logic to ensure that the compensated PWM value does not exceed the safe operating range of the laser. For sudden rapid temperature changes, the program uses a predictive extrapolation algorithm to adjust the compensation amount in advance and reduce response delay.

[0046] Step 4: Adaptive heat dissipation control process. The system dynamically adjusts the heat dissipation strategy based on temperature monitoring results. The physical control process is as follows: The microcontroller calculates the highest temperature T_max and the maximum temperature difference ΔT_max at the four monitoring points. If T_max < 60℃, the GPIO outputs a PWM signal with a 50% duty cycle, and the fan runs at a medium speed. If 60℃ ≤ T_max < 70℃, the PWM duty cycle of the four GPIOs is adjusted according to the temperature difference in each area, and the fan speed in the high-temperature area is increased to 70-80%. If T_max ≥ 70℃, all GPIOs output a 100% duty cycle, and the fan runs at full speed. At the same time, if ΔT_max > 8℃, the thermal balance mode is activated, which promotes the uniform distribution of heat among the areas by adjusting the angle of the air duct baffle and the fan speed ratio.

[0047] In step four, the adaptive heat dissipation control process is implemented through a three-level temperature management state machine program. This program implements a finite state machine to manage the three working states of the system. The state machine performs state transitions based on the values ​​and trends of T_max and ΔT_max. In the normal state, the program only performs basic color compensation and routine heat dissipation. In the warning state, the program starts enhanced monitoring, shortens the temperature acquisition interval to 50μs, and calculates the temperature change trend to predict whether it is necessary to enter the protection state. In the protection state, the program performs gradual brightness adjustment, reducing the brightness by 1-2% per second, and monitors whether the temperature drops. The state transition process is logged in detail for subsequent fault analysis and parameter optimization.

[0048] Step 5: Data Learning and Optimization Process. Before each shutdown, the system performs data recording and parameter optimization. The physical process is as follows: The microcontroller packages the temperature change curve, compensation adjustment records, and user color setting preferences during the current operation; it writes this data to a designated storage area of ​​the EEPROM via the I²C bus, using page programming, writing 256 bytes at a time; simultaneously, it reads historical data records, analyzes the compensation effect, and if the compensation error in a certain temperature range is found to be consistently large, it automatically adjusts the compensation coefficient α value for that range; the optimized new parameters are written to another storage area of ​​the EEPROM as the initial parameters for the next power-on. This process is completed within 5 seconds before power-off to ensure data integrity.

[0049] In step five, the data learning and optimization process is implemented through an adaptive learning algorithm program. This program runs when the system is idle, analyzes historical operating data, reads the temperature-compensation records of the most recent 100 runs from the EEPROM, uses the least squares method to fit the actual temperature-efficiency curve of each laser, compares it with the theoretical curve to obtain the correction coefficient, and the learning algorithm also considers the influence of ambient temperature and running time to establish a multi-dimensional compensation model. When enough data is accumulated, the program automatically generates an optimized compensation parameter table to replace the original fixed parameters.

[0050] It also includes a user interface and exception handling program. The user interface and exception handling program provide a user configuration interface and exception handling mechanism. Users can adjust color preferences through the projection menu. The program converts the user settings into the bias amount of the compensation parameters. When a hardware failure is detected, the program starts a degraded operation mode: if a temperature sensor fails, it uses data interpolation from adjacent sensors to replace it; if a fan fails, it increases the speed of other fans to compensate for the heat dissipation capacity; if the laser temperature continues to be abnormal, it gradually reduces the brightness until it is safely shut down. All abnormal events are recorded in EEPROM and can be read and analyzed through the debugging interface.

[0051] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A temperature adaptive color correction system for a DLP projection device, characterized in that: It includes an optical temperature monitoring module, a main control processing module, an execution drive module, and a heat dissipation structure module. The optical temperature monitoring module includes four temperature sensors installed inside the optical engine of the DLP projection device. The optical engine includes an RGB laser. The optical temperature monitoring module is used for temperature monitoring. The main control processing module uses a microcontroller as the core processor and is installed on the main control board of the DLP projection device. The microcontroller includes four ADC channels, which are respectively connected to the signal input terminals of the four temperature sensors. The main control processing module is used for color compensation calculation. The execution drive module includes three sub-units: the first sub-unit is an RGB laser driver circuit connected to the microcontroller; the second sub-unit is a multi-zone fan control circuit; and the third sub-unit is a power management circuit. The third sub-unit is used to provide stable 3.3V and 5V voltages to the entire system. The execution drive module is used for heat dissipation control. The microcontroller is connected to an EEPROM memory chip via an I²C bus. The EEPROM memory chip is used for data storage and learning. The heat dissipation structure module includes four axial fans and air ducts corresponding to the axial fans, and the power line of each axial fan is connected to the second sub-unit.

2. The temperature-adaptive color correction system for a DLP projection device of claim 1, wherein: The four temperature sensors are designated as sensor S1, sensor S2, sensor S3, and sensor S4. The RGB laser consists of a red laser, a green laser, and a blue laser. Sensor S1 is directly attached to the copper heat sink substrate of the red laser using thermally conductive silicone, 3-5 mm away from the laser emission point. Sensor S2 is directly attached to the heat sink substrate of the green laser using thermally conductive silicone. Sensor S3 is mounted on the heat sink substrate of the blue laser. Sensor S4 is fixed to the center of the aluminum heat sink fins below the DMD chip using a miniature bracket. The microcontroller is an S32K144 microcontroller. The main control board has four ADC interface sockets connected to the four ADC channels of the microcontroller. The signal lines of the four temperature sensors are connected to the four ADC interface sockets on the main control board via four-core shielded cables, each less than 15 cm long.

3. The temperature-adaptive color correction system for a DLP projection device of claim 2, wherein: The microcontroller also includes three FTM timers and four GPIO pins. The outputs of the three FTM timers are connected to the RGB laser driver circuit, and the four GPIO pins are connected to the multi-zone fan control circuit.

4. The temperature-adaptive color correction system for a DLP projection device of claim 3, wherein: The RGB laser driving circuit of the first sub-unit includes three independent constant current PWM driving chips. The PWM input terminal of each constant current PWM driving chip is connected to the corresponding FTM timer output terminal of the microcontroller, and the current output terminal of each constant current PWM driving chip is connected to the corresponding color RGB laser through copper foil traces. The multi-region fan control circuit of the second sub-unit includes four MOSFET switches that are respectively connected to the axial fan control line. The gate of each MOSFET switch is connected to four GPIO pins of the microcontroller, and the drain is connected to the positive power supply of the corresponding axial fan.

5. The temperature-adaptive color correction system for a DLP projection device of claim 2, wherein: The four axial fans are fan F1, fan F2, fan F3 and fan F4. Fan F1 is installed on the air intake side of the red laser heat sink, 10mm away from the heat sink fins. Fan F2 is installed in the same position as the heat sink of the green laser; fan F3 is installed in the same position as the heat sink of the blue laser; fan F4 is installed on the exhaust side of the heat sink of the DMD chip.

6. The temperature-adaptive color correction system for a DLP projection device as described in claim 1, characterized in that: The temperature sensor uses an NTC thermistor sensor, and four NTC thermistors can convert temperature changes into resistance changes.

7. A temperature-adaptive color correction method for DLP projection devices, characterized in that, The temperature-adaptive color correction system for a DLP projection device as described in any one of claims 4 to 6 further includes the following steps: Step 1: System Initialization Process. After the projection device is powered on, the power management circuit generates stable 3.3V and 5V voltages. The microcontroller is powered on and reset, first executing the hardware self-test program. It reads the initial values ​​of the four temperature sensors through the ADC to determine whether the temperature sensors are working properly; it reads the device serial number and calibration parameters from the EEPROM storage chip through the I²C bus; it initializes the FTM timer to generate a PWM test signal at the reference frequency to verify the function of the laser driver circuit; it controls the axial fan to rotate at full speed for 3 seconds through GPIO to remove dust and test the fan performance. After the self-test is completed, the system enters standby mode, waiting for the user's power-on command. Step 2: Temperature Data Acquisition Process. After the user turns on the projector, the optical temperature monitoring module starts working. The thermistor in each temperature sensor changes its resistance with temperature, causing the voltage divider circuit to output a change in voltage. These analog voltage signals are transmitted to the input pin of the microcontroller's ADC channel through PCB traces. The microcontroller's ADC module samples the four ADC channels in turn at 100μs intervals, converting the analog voltage into a 12-bit digital value, where 0-4095 corresponds to 0-3.3V. During the sampling process, a hardware anti-aliasing filter eliminates high-frequency noise, and a sample-and-hold circuit ensures the time synchronization of the four ADC channels. The converted digital value is stored in the microcontroller's DMA buffer for subsequent processing. Step 3: Real-time color compensation process. The microcontroller reads the latest temperature data from the DMA buffer every 10ms and performs compensation calculations. The physical calculation process is as follows: First, the raw ADC value is converted into the actual temperature value using the formula T=(4095 / ADC_raw-1)×R_series / β, where β is the constant B value of the thermistor; then, the difference ΔT between the current temperature of each laser and the 25℃ reference temperature is calculated; next, the new PWM duty cycle is calculated using the compensation formula PWM_new=PWM_base×[1 / (1+α×ΔT)], where α is the temperature attenuation coefficient of each laser; finally, the calculation results are written to the comparison register of the FTM timer, and the hardware automatically updates the PWM output waveform. This process is completed within 10ms to ensure the real-time performance of the compensation. Step 4: Adaptive heat dissipation control process. The system dynamically adjusts the heat dissipation strategy based on temperature monitoring results. The physical control process is as follows: The microcontroller calculates the highest temperature T_max and the maximum temperature difference ΔT_max at the four monitoring points. If T_max < 60℃, the GPIO outputs a PWM signal with a 50% duty cycle, and the fan runs at a medium speed. If 60℃ ≤ T_max < 70℃, the PWM duty cycle of the four GPIOs is adjusted according to the temperature difference in each area, and the fan speed in the high-temperature area is increased to 70-80%. If T_max ≥ 70℃, all GPIOs output a 100% duty cycle, and the fan runs at full speed. At the same time, if ΔT_max > 8℃, the thermal balance mode is activated, which promotes the uniform distribution of heat among the areas by adjusting the angle of the air duct baffle and the fan speed ratio. Step 5: Data Learning and Optimization Process. Before each shutdown, the system performs data recording and parameter optimization. The physical process is as follows: The microcontroller packages the temperature change curve, compensation adjustment records, and user color setting preferences during the current operation; it writes this data to a designated storage area of ​​the EEPROM via the I²C bus, using page programming, writing 256 bytes at a time; simultaneously, it reads historical data records, analyzes the compensation effect, and if the compensation error in a certain temperature range is found to be consistently large, it automatically adjusts the compensation coefficient α value for that range; the optimized new parameters are written to another storage area of ​​the EEPROM as the initial parameters for the next power-on. This process is completed within 5 seconds before power-off to ensure data integrity.

8. The temperature-adaptive color correction method for a DLP projection device as described in claim 7, characterized in that: In step two, the temperature data acquisition process is implemented through a multi-channel temperature synchronous acquisition program. Specifically, the multi-channel temperature synchronous acquisition program is completed by the interrupt service routine and the DMA controller. The timer interrupt is triggered once every 100μs. The sequential scan conversion of the ADC is started in the interrupt service routine. After the ADC completes the conversion of four channels, the data is directly transferred to the memory buffer through the DMA request. The program implements a circular buffer and a double buffering mechanism to ensure that the data is continuous and not lost. At the same time, the program monitors the validity of the data of each channel in real time. If an abnormal sensor data is found, the fault is automatically marked and the backup compensation strategy is activated. In step three, the color compensation process is implemented through a temperature-color compensation algorithm. This algorithm executes every 10ms in the main loop. The program first retrieves the latest four temperature values ​​from the circular buffer, converts the original ADC values ​​to Celsius using a lookup table, and then uses a floating-point arithmetic library to calculate the temperature compensation coefficient for each laser. The calculation process includes exponential smoothing filtering to avoid sudden changes in PWM output. The program also implements boundary protection logic to ensure that the compensated PWM value does not exceed the safe operating range of the laser. For sudden rapid temperature changes, the program uses a predictive extrapolation algorithm to adjust the compensation amount in advance and reduce response delay.

9. The temperature-adaptive color correction method for a DLP projection device as described in claim 8, characterized in that: In step four, the adaptive heat dissipation control process is implemented through a three-level temperature management state machine program. This program implements a finite state machine to manage the three working states of the system. The state machine performs state transitions based on the values ​​and trends of T_max and ΔT_max. In the normal state, the program only performs basic color compensation and conventional heat dissipation. In the warning state, the program starts enhanced monitoring, shortens the temperature acquisition interval to 50μs, and calculates the temperature change trend to predict whether it is necessary to enter the protection state. In protection mode, the program performs a gradual brightness adjustment, reducing the brightness by 1-2% per second, and monitors whether the temperature drops. The state transition process is logged in detail for subsequent fault analysis and parameter optimization.

10. The temperature-adaptive color correction method for a DLP projection device as described in claim 1, characterized in that: In step five, the data learning and optimization process is implemented through an adaptive learning algorithm program. This program runs when the system is idle, analyzes historical running data, reads the temperature-compensation records of the most recent 100 runs from the EEPROM, uses the least squares method to fit the actual temperature-efficiency curve of each laser, compares it with the theoretical curve to obtain the correction coefficient, and the learning algorithm also considers the influence of ambient temperature and running time to establish a multi-dimensional compensation model. When enough data is accumulated, the program automatically generates an optimized compensation parameter table to replace the original fixed parameters. It also includes a user interface and exception handling program. The user interface and exception handling program provide a user configuration interface and exception handling mechanism. Users can adjust color preferences through the projection menu. The program converts the user settings into the bias amount of the compensation parameters. When a hardware failure is detected, the program starts a degraded operation mode: if a temperature sensor fails, it uses the data interpolation of the adjacent sensor as a substitute. If a fan fails, the speed of other fans is increased to compensate for the heat dissipation; if the laser temperature continues to be abnormal, the brightness is gradually reduced until it is safely shut down. All abnormal events are recorded in the EEPROM and can be read and analyzed through the debugging interface.

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