Method for obtaining optical parameters of vehicle-mounted display screen under high and low temperature environments
Patent Information
- Application Number
- CN202510380039.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-28
- Publication Date
- 2026-09-29
AI Technical Summary
[0003]然而，上述方法所需温箱非常大，成本高；更换测试界面需要人来处理，由于光学参数测试时间长，环境温度过高（80℃）或过低人无法长时间活动；并且，测试仪器一般都为高精密的摄像头，在高温的环境下容易发生不可逆的温漂现象导致摄像头的解像力降低，而这种温漂是由于材料收温度变形导致的，高低温会导致摄像头解像力不可逆的损伤
[0012]本申请的实施例提供的获得车载显示屏高低温环境下光学参数的方法，通过调节滑动变阻器的方式模拟温敏电阻在高低温环境温度的阻值，实现对车载显示屏感测温度的模拟，不需要设置温箱，仅需进行硬件更改，成本较低；操作人员无需进入高低温环境，操作简单；测试设备也无需在高低温环境下工作，避免设备出现精度问题和硬件损坏。
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Figure CN122835690A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle technology, specifically to a method for obtaining optical parameters of an in-vehicle display screen under high and low temperature environments. Background Technology
[0002] Currently, testing the high and low temperature optical parameters of automotive display screen components is conducted under high and low temperature conditions. Related technologies typically require testing optical parameters in a variable temperature environment. The specific method is as follows: the car is driven into a very large temperature chamber, and the chamber environment is controlled. Once the predicted temperature is reached, it needs to be maintained at that temperature for approximately one hour, after which measurements are taken. During this process, the display screen operates as follows: the resistance of the NTC (thermistor) changes with the ambient temperature. The display's MCU identifies the NTC change through the ADC function, thus obtaining the ambient temperature. Then, the display is operated through a program, such as controlling the brightness, color, and gamma value. Finally, testing instruments perform relevant tests on the display.
[0003] However, the above methods require very large temperature chambers, which are costly; changing the test interface requires human intervention, and due to the long testing time for optical parameters, people cannot work for extended periods in environments that are too hot (80°C) or too cold; furthermore, the testing instruments are generally high-precision cameras, which are prone to irreversible temperature drift in high-temperature environments, leading to a reduction in the camera's resolution. This temperature drift is caused by material deformation due to temperature, and both high and low temperatures can cause irreversible damage to the camera's resolution. Summary of the Invention
[0004] To at least partially solve the above problems, embodiments of this application provide a method for obtaining optical parameters of an in-vehicle display screen under high and low temperature environments. The in-vehicle display screen adjusts its optical parameters based on the temperature sensed by an internally installed thermistor. The method includes: obtaining the relationship between the resistance value of the thermistor and temperature; removing the thermistor from its circuit in the in-vehicle display screen; installing a sliding rheostat in the original installation position of the thermistor; adjusting the resistance value of the sliding rheostat based on the relationship between the resistance value of the thermistor and temperature, so that the controller of the in-vehicle display screen adjusts the optical parameters of the in-vehicle display screen based on the temperature corresponding to the resistance value of the sliding rheostat; and measuring the optical parameters of the in-vehicle display screen.
[0005] In some embodiments, the optical parameters include one or more of the brightness, color, and gamma value of the vehicle display.
[0006] In some embodiments, a thermistor is connected in series with a known resistor in the power supply of the vehicle display screen to obtain the relationship between the resistance value of the thermistor and the temperature, including: obtaining the resistance value of the known resistor connected in series with the thermistor; obtaining the temperature sensed by the thermistor through the vehicle display screen; obtaining the voltage across the thermistor through the controller of the vehicle display screen; obtaining the resistance value of the thermistor at the current temperature based on the power supply voltage of the vehicle display screen, the resistance value of the known resistor, and the voltage across the thermistor; and recording the temperatures sensed by multiple thermistors and the corresponding resistance values of the thermistors to obtain the relationship between the resistance value of the thermistor and the temperature.
[0007] In some embodiments, the resistance of the thermistor at the current temperature is calculated by the following formula: U1=Vcc / (R1+R2)*R2, where Vcc is the power supply voltage of the vehicle display screen, R1 is the resistance of a known resistor, R2 is the resistance of the thermistor at the current temperature, and U1 is the voltage across the thermistor.
[0008] In some embodiments, the maximum resistance of the sliding rheostat is greater than the maximum resistance of the thermistor.
[0009] In some embodiments, measuring the optical parameters of the vehicle display screen includes: taking a picture of the display screen with a camera, and then analyzing the acquired picture to obtain the optical parameters of the vehicle display screen.
[0010] In some embodiments, the vehicle display screen is kept on for 1 ± 0.05 hours before the camera takes a picture of the screen displayed on the vehicle display screen.
[0011] In some embodiments, when measuring the optical parameters of the vehicle display screen at a preset temperature, the first resistance value of the thermistor corresponding to the preset temperature is obtained based on the relationship between the resistance value of the thermistor and the temperature, and when adjusting the sliding rheostat, the resistance value of the sliding rheostat is adjusted to be less than the first resistance value.
[0012] The method for obtaining optical parameters of a vehicle display screen under high and low temperature environments provided in the embodiments of this application simulates the resistance of a thermistor at high and low temperature environments by adjusting a sliding rheostat, thereby simulating the temperature sensing of the vehicle display screen. It does not require setting up a temperature chamber, only hardware modifications are needed, and the cost is low. Operators do not need to enter the high and low temperature environment, making the operation simple. The testing equipment also does not need to work in high and low temperature environments, avoiding accuracy problems and hardware damage. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of this application or 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 only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 This is a schematic diagram of a method for obtaining optical parameters of an in-vehicle display screen under high and low temperature environments in related technologies.
[0015] Figure 2 This is a schematic diagram of a method for obtaining optical parameters of an in-vehicle display screen under high and low temperature environments, provided in an embodiment of this application. Detailed Implementation
[0016] The preferred embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection claimed in this application.
[0017] The terms "first," "second," and similar words used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.
[0018] Please see Figure 1(PCB refers to printed circuit board) In related technologies, when obtaining the optical parameters of an in-vehicle display screen under high and low temperature environments, the car is typically driven into a very large temperature chamber. The environment of the high and low temperature chamber is operated, and once the predicted temperature is reached, it needs to be maintained at that temperature for about one hour before measurement. During this time, the display screen operates as follows: when the ambient temperature changes, the resistance values of the thermistors (NTC1 and NTC2, corresponding to display screen 1 and display screen 2 respectively) change accordingly. The display screen's controller (MCU) identifies the changes in the thermistors through the analog-to-digital converter (ADC) function, thereby obtaining the ambient temperature. Then, the display screens (display screen 1 and display screen 2) are operated through a program, such as controlling the brightness, color, and gamma value. Finally, testing instruments perform relevant tests on the display screens. However, the above methods require very large temperature chambers, which are costly; changing the test interface requires human intervention, and due to the long testing time for optical parameters, people cannot work for extended periods in environments that are too hot (80°C) or too cold; furthermore, the testing instruments are generally high-precision cameras, which are prone to irreversible temperature drift in high-temperature environments, leading to a reduction in the camera's resolution. This temperature drift is caused by material deformation due to temperature, and both high and low temperatures can cause irreversible damage to the camera's resolution.
[0019] To at least partially resolve the above issues, please refer to Figure 2 This application provides a method for obtaining optical parameters of an in-vehicle display screen under high and low temperature environments. The in-vehicle display screen adjusts its optical parameters based on the temperature sensed by an internally installed thermistor. The method includes: obtaining the relationship between the resistance value of the thermistor and temperature; removing the thermistor from its circuit in the in-vehicle display screen; and removing the sliding rheostat ( Figure 2 RP1 and RP2 are used to represent the display screen 1 and display screen 2, respectively, which are installed at the original mounting positions of the thermistor. Based on the relationship between the resistance of the thermistor and temperature, the resistance of the sliding rheostat is adjusted so that the controller of the vehicle display screen adjusts the optical parameters of the vehicle display screen based on the temperature corresponding to the resistance of the sliding rheostat. The optical parameters of the vehicle display screen are measured. In some embodiments, the optical parameters include one or more of the following: brightness, color, and gamma value of the vehicle display screen.
[0020] The method for obtaining optical parameters of a vehicle display screen under high and low temperature environments provided in the embodiments of this application simulates the resistance of a thermistor at high and low temperature environments by adjusting a sliding rheostat, thereby simulating the temperature sensing of the vehicle display screen. It does not require setting up a temperature chamber, only hardware modifications are needed, and the cost is low. Operators do not need to enter the high and low temperature environment, making the operation simple. The testing equipment also does not need to work in high and low temperature environments, avoiding accuracy problems and hardware damage.
[0021] In some embodiments, a thermistor is connected in series with a known resistor in the power supply of the vehicle display screen to obtain the relationship between the thermistor's resistance and temperature. This includes: obtaining the resistance value of the known resistor connected in series with the thermistor; obtaining the temperature sensed by the thermistor through the vehicle display screen; obtaining the voltage across the thermistor through the controller of the vehicle display screen; obtaining the resistance value of the thermistor at the current temperature based on the power supply voltage of the vehicle display screen, the resistance value of the known resistor, and the voltage across the thermistor; and recording the temperatures sensed by multiple thermistors and the corresponding resistance values of the thermistors to obtain the relationship between the thermistor's resistance and temperature. Specifically, in some embodiments, the resistance value of the thermistor at the current temperature is calculated using the following formula: U1 = Vcc / (R1 + R2) * R2, where Vcc is the power supply voltage of the vehicle display screen, R1 is the resistance value of the known resistor, R2 is the resistance value of the thermistor at the current temperature, and U1 is the voltage across the thermistor. In this embodiment, this method is simple to operate and can obtain the relationship between the thermistor's resistance and temperature using the existing hardware of the vehicle display screen.
[0022] In some embodiments, the maximum resistance of the sliding rheostat is greater than the maximum resistance of the thermistor. In this embodiment, this allows the resistance variation range of the sliding rheostat to cover the resistance variation range of the thermistor, thereby simulating all temperature values that the thermistor can sense.
[0023] In some embodiments, measuring the optical parameters of the vehicle-mounted display screen includes: taking a picture of the display screen with a camera, and then analyzing the acquired picture to obtain the optical parameters of the vehicle-mounted display screen. Specifically, the screen can be driven to light up using CANoe simulation, displaying the image to be tested (a solid color image such as red, green, blue, black, or white) and brightness level, and then the screen can be photographed and analyzed.
[0024] In some embodiments, the vehicle display screen is kept on for 1 ± 0.05 hours before the camera takes a picture of the screen. In this embodiment, by making the vehicle display screen work continuously for 1 ± 0.05 hours, the operating conditions of the vehicle display screen when the temperature chamber is actually used can be simulated, making the measurement results more accurate.
[0025] In some embodiments, when measuring the optical parameters of an in-vehicle display screen at a preset temperature, a first resistance value of the thermistor corresponding to the preset temperature is obtained based on the relationship between the resistance value of the thermistor and temperature. When adjusting the sliding rheostat, the resistance value of the sliding rheostat is adjusted to be less than the first resistance value. Preferably, the resistance value of the sliding rheostat can be adjusted to be slightly less than the first resistance value, and the difference between the two can be determined based on empirical values. Considering that the electronic screen itself will also experience temperature rise in high-temperature environments, the actual temperature will be higher, and the corresponding resistance value of the thermistor will be lower. In this embodiment, this method can make the measurement results more accurate.
[0026] The method for obtaining optical parameters of an in-vehicle display screen under high and low temperature environments provided in the embodiments of this application uses a sliding rheostat instead of a thermistor to simulate the resistance value of the thermistor under different temperature conditions. Specifically, the resistance value of the sliding rheostat can be adjusted to simulate the resistance value of the thermistor, thereby simulating the ambient temperature. The MCU identifies the simulated ambient temperature through the resistance value of the sliding rheostat and then operates the display screen through the program, such as controlling the brightness, color, and gamma of the display screen. The method for obtaining optical parameters of an in-vehicle display screen under high and low temperature environments provided in the embodiments of this application can test the implementation status of the derating strategy of the in-vehicle display screen at different temperatures under normal temperature conditions. It can complete the high and low temperature optical parameter test under normal temperature conditions. The test method is simple and quick, the test vehicle and personnel are not in high and low temperature environments, the measuring equipment will not be damaged by high temperature environments, and no additional high and low temperature equipment is required.
[0027] Based on the various embodiments of this application described above, in the absence of explicit denial or conflict, the technical features of one embodiment may be advantageously combined with one or more other embodiments.
[0028] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.
Claims
1. A method for obtaining optical parameters of an in-vehicle display screen under high and low temperature environments, characterized in that, The in-vehicle display adjusts its optical parameters based on the temperature sensed by an internally installed thermistor, the method comprising: The relationship between the resistance value of the temperature-sensitive resistor and temperature is obtained; Remove the thermistor from the circuit of the vehicle display screen; Install the sliding rheostat in the original installation position of the temperature-sensitive resistor; Based on the relationship between the resistance of the temperature-sensitive resistor and the temperature, the resistance of the sliding rheostat is adjusted so that the controller of the vehicle display screen adjusts the optical parameters of the vehicle display screen based on the temperature corresponding to the resistance of the sliding rheostat. The optical parameters of the vehicle-mounted display screen are measured.
2. The method according to claim 1, characterized in that, The optical parameters include one or more of the brightness, color, and gamma value of the vehicle display screen.
3. The method according to claim 2, characterized in that, The thermistor is connected in series with a known resistor in the power supply of the vehicle display screen. The relationship between the resistance of the thermistor and temperature is obtained, including: Obtain the resistance value of the known resistor connected in series with the temperature-sensitive resistor; The temperature sensed by the thermistor is obtained through the vehicle-mounted display screen; The voltage across the thermistor is obtained through the controller of the vehicle display screen; The resistance value of the temperature-sensitive resistor at the current temperature is obtained based on the power supply voltage of the vehicle display screen, the resistance value of the known resistor, and the voltage across the temperature-sensitive resistor. Record the temperatures sensed by multiple thermistors and the corresponding resistance values of the thermistors to obtain the relationship between the resistance value of the thermistors and the temperature.
4. The method according to claim 3, characterized in that, The resistance of the thermostat at the current temperature is calculated using the following formula: U1 = Vcc / (R1 + R2) * R2, Wherein, Vcc is the power supply voltage of the vehicle display screen, R1 is the resistance value of the known resistor, R2 is the resistance value of the thermistor at the current temperature, and U1 is the voltage across the thermistor.
5. The method according to claim 1, characterized in that, The maximum resistance of the sliding rheostat is greater than the maximum resistance of the temperature-sensitive resistor.
6. The method according to claim 1, characterized in that, Measuring the optical parameters of the vehicle-mounted display screen includes: The camera takes pictures of the display screen in the vehicle, and then the acquired pictures are analyzed to obtain the optical parameters of the vehicle display screen.
7. The method according to claim 6, characterized in that, Before taking a picture of the display screen with a camera, the vehicle display screen is kept on for 1 ± 0.05 hours.
8. The method according to claim 7, characterized in that, When measuring the optical parameters of the vehicle display screen at a preset temperature, the first resistance value of the thermistor corresponding to the preset temperature is obtained based on the relationship between the resistance value of the thermistor and the temperature. When adjusting the sliding rheostat, the resistance value of the sliding rheostat is adjusted to be less than the first resistance value.