Automatic display screen brightness adjusting system based on localization

Abstract

The utility model discloses an automatic display screen brightness adjusting system based on localization. The automatic display screen brightness adjusting system comprises a primary trans-impedance amplifier circuit unit, a fixed gain amplifier circuit unit and a low-pass active filter circuit unit, the primary transimpedance amplifier circuit unit is an amplifying circuit used for detecting a photosensitive diode, input current is converted into output voltage through a negative feedback loop, and primary photoelectric conversion of ambient light is achieved; the fixed gain amplifier circuit unit is used for further amplifying the output voltage of the primary trans-impedance amplifier circuit unit; and the low-pass active filter circuit unit comprises a low-pass filter network and a voltage clamping circuit and can clamp the maximum value of the output voltage to 3.3 V while filtering high-frequency interference in the circuit so as to protect the ADC port of the CPU, the CPU is connected with the display screen, and the CPU adjusts the brightness of the display screen according to the acquired output signal of the low-pass active filter circuit unit. According to the utility model, the secondary problems of interference, self-excitation and the like caused by adopting domestic devices are solved.

Description

Technical Field

[0001] This utility model belongs to the field of display screen system technology, specifically relating to a domestically produced automatic brightness adjustment system for display screens. Background Technology

[0002] During flight, the ambient light intensity on the display screen changes rapidly due to flight attitude and high-altitude environment. Consequently, the screen brightness fluctuates, causing pilot eye fatigue and difficulty in clearly viewing the information displayed. More seriously, this can lead to flight safety accidents. Relying on crew members to manually and frequently adjust the brightness knobs or buttons on the display screen would undoubtedly increase their workload and is impractical. Therefore, to ensure that pilots and fellow crew members can clearly view the displayed information in both static and dynamic environments, the display brightness must be able to automatically adjust in response to changes in ambient light outside the cockpit.

[0003] In traditional airborne display automatic brightness adjustment systems, the photosensitive components and acquisition circuits often rely on imported solutions. With the various restrictions imposed on my country's electronics industry by foreign countries in recent years, although the domestic semiconductor industry has gradually emerged, it is constrained by the insufficient integration of domestically produced ambient light sensors, requiring external transimpedance amplifiers for photoelectric conversion. This often leads to secondary problems such as circuit self-oscillation and interference. Furthermore, most domestically produced amplifiers are linear devices, which are not fully compatible with optical nonlinearity, necessitating special algorithms for conversion in the intermediate acquisition and brightness adjustment stages.

[0004] Based on the above actual situation, this utility model designs an automatic brightness adjustment system for a display screen based on domestically produced components. This solution not only completes the automatic brightness adjustment function of traditional airborne display screens, but also effectively solves the secondary problems such as self-excitation and interference caused by the use of domestically produced components. Utility Model Content

[0005] The purpose of this invention is to provide an automatic brightness adjustment system for a display screen based on domestically produced components. This system solves secondary problems such as interference and self-oscillation caused by the use of domestically produced components. It features low noise, low latency, and high sensitivity, and enables automatic brightness adjustment of the display screen.

[0006] This utility model is achieved through the following technical solution:

[0007] An automatic brightness adjustment system for a display screen based on domestic technology includes a primary transimpedance amplifier circuit unit, a fixed gain amplifier circuit unit, a low-pass active filter circuit unit, a CPU, and a display screen.

[0008] The primary transimpedance amplifier circuit unit has its input terminal connected to a photodiode on the light guide plate of the display screen; the fixed gain amplifier circuit unit has its input terminal connected to the output terminal of the primary transimpedance amplifier circuit unit; the low-pass active filter circuit unit has its input terminal connected to the output terminal of the fixed gain amplifier circuit unit, and its output terminal connected to the ADC port of the CPU. The low-pass active filter circuit unit includes a low-pass filter network and a voltage clamping circuit; the CPU is connected to the display screen, and the CPU adjusts the brightness of the display screen according to the output signal of the acquired low-pass active filter circuit unit.

[0009] In the above technical solution, the primary transimpedance amplifier circuit unit, the fixed gain amplifier circuit unit, and the low-pass active filter circuit unit all use the domestically produced SGM8425AYN5G / TR chip.

[0010] In the above technical solution, the primary transimpedance amplifier circuit unit includes a first operational amplifier, which adopts a domestically produced SGM8425AYN5G / TR chip. The inverting input terminal -IN of the first operational amplifier is connected to the negative terminal of the photodiode through resistor R37; the non-inverting input terminal +IN of the first operational amplifier is connected to the positive terminal of the photodiode through resistor R35, and connected to GND through resistor R34; the output terminal of the first operational amplifier is connected to the inverting input terminal -IN of the first operational amplifier through resistor R38. Resistor R38 serves as a negative feedback resistor, and capacitor C9 is connected in parallel with the negative feedback resistor R38 to form a phase compensation circuit, effectively eliminating the circuit self-oscillation problem.

[0011] In the above technical solution, the fixed-gain amplifier circuit unit includes a second operational amplifier. The second operational amplifier uses a domestically produced SGM8425AYN5G / TR chip. The non-inverting input terminal +IN of the second operational amplifier is connected to the output terminal of the first operational amplifier in the primary transimpedance amplifier circuit unit via resistor R36. The inverting input terminal -IN of the second operational amplifier is connected to its output terminal via resistor R41, and further connected to GND via resistor R44. The second operational amplifier further amplifies the output voltage of the primary transimpedance amplifier circuit unit to a voltage value that meets the amplitude requirements of the ADC interface of the backend CPU, thereby achieving better acquisition sensitivity.

[0012] In the above technical solution, the low-pass active filter circuit unit includes a third operational amplifier. The third operational amplifier uses a domestically produced SGM8425AYN5G / TR chip. The non-inverting input terminal +IN of the third operational amplifier is connected to the output terminal of the second operational amplifier of the fixed gain amplifier circuit unit through resistor R40. The non-inverting input terminal +IN of the third operational amplifier is also connected to the output terminal of the third operational amplifier through resistor R40 and capacitor C5. The non-inverting input terminal +IN of the third operational amplifier is also connected to GND through capacitor C11, together forming a low-pass filter network. The output terminal of the third operational amplifier of the low-pass active filter circuit unit is connected to diodes VD22 and VD23 to form a voltage clamping circuit.

[0013] The advantages and beneficial effects of this utility model are as follows:

[0014] This invention integrates a primary transimpedance amplifier circuit unit, a fixed gain amplifier circuit unit, and a low-pass active filter circuit unit, solving secondary problems such as interference and self-oscillation caused by the use of domestically produced components. It features low noise, low latency, and high sensitivity, enabling automatic brightness adjustment of the display and effectively improving the stability and user experience of the automatic brightness adjustment system based on domestically produced displays. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the system architecture of this utility model.

[0016] Figure 2 This is the circuit diagram of the primary transimpedance amplifier circuit unit.

[0017] Figure 3 This is a circuit diagram of a fixed gain amplifier circuit unit.

[0018] Figure 4 It is the circuit of the low-pass active filter circuit unit. Detailed Implementation

[0019] The technical solution of this utility model will be further illustrated below with specific examples.

[0020] See appendix Figure 1 An automatic brightness adjustment system for a display screen based on domestic technology includes a primary transimpedance amplifier circuit unit, a fixed gain amplifier circuit unit, a low-pass active filter circuit unit, a CPU, and a display screen.

[0021] The primary transimpedance amplifier circuit unit, with its input terminal connected to the photodiode on the light guide plate of the display screen, is an amplification circuit used for photodiode detection. It converts the input current into output voltage through a negative feedback loop, achieving primary photoelectric conversion of ambient light. The fixed gain amplifier circuit unit, with its input terminal connected to the output terminal of the primary transimpedance amplifier circuit unit, further amplifies the output voltage of the primary transimpedance amplifier circuit unit, ensuring the voltage amplitude meets the appropriate voltage amplitude range of the CPU's ADC port, thereby obtaining a wider range and higher sensitivity acquisition voltage value. The low-pass active filter circuit unit, with its input terminal connected to the output terminal of the fixed gain amplifier circuit unit and its output terminal connected to the CPU's ADC port on the display screen, includes a low-pass filter network and a voltage clamping circuit. It filters out high-frequency interference in the circuit while clamping its maximum output voltage to 3.3V to protect the CPU's ADC port. The CPU is connected to the display screen, and the CPU adjusts the brightness of the display screen based on the acquired output signal from the low-pass active filter circuit unit.

[0022] The specific structure of each component of the domestically produced automatic brightness adjustment system for displays is described in detail below.

[0023] See appendix Figure 2 The primary transimpedance amplifier circuit unit includes a first operational amplifier, which uses a domestically produced SGM8425AYN5G / TR chip. The SGM8425AYN5G / TR is a domestically produced low-noise, high-bandwidth, rail-to-rail operational amplifier. The inverting input terminal -IN of the first operational amplifier is connected to the negative terminal of the photodiode through resistor R37; the non-inverting input terminal +IN of the first operational amplifier is connected to the positive terminal of the photodiode through resistor R35, and then connected to GND through resistor R34; the output terminal of the first operational amplifier is connected to the inverting input terminal -IN of the first operational amplifier through resistor R38. Resistor R38 serves as a negative feedback resistor, and capacitor C9 is connected in parallel with the negative feedback resistor R38 to form a phase compensation circuit, effectively eliminating the circuit self-oscillation problem.

[0024] See appendix Figure 3The fixed-gain amplifier circuit unit includes a second operational amplifier, which also uses a domestically produced SGM8425AYN5G / TR chip. The non-inverting input terminal +IN of the second operational amplifier is connected to the output terminal of the first operational amplifier in the primary transimpedance amplifier circuit unit via resistor R36. The inverting input terminal -IN of the second operational amplifier is connected to its output terminal via resistor R41, and further connected to GND via resistor R44. The second operational amplifier further amplifies the output voltage of the primary transimpedance amplifier circuit unit to a voltage value that meets the amplitude requirements of the ADC interface of the backend CPU, thereby achieving better acquisition sensitivity.

[0025] See appendix Figure 4 The low-pass active filter circuit unit includes a third operational amplifier, which also uses a domestically produced SGM8425AYN5G / TR chip. The non-inverting input terminal +IN of the third operational amplifier is connected to the output terminal of the second operational amplifier of the fixed gain amplifier circuit unit through resistor R40. The non-inverting input terminal +IN of the third operational amplifier is also connected to the output terminal of the third operational amplifier through resistor R40 and capacitor C5. The non-inverting input terminal +IN of the third operational amplifier is also connected to GND through capacitor C11, together forming a low-pass filter network. The cutoff frequency of this low-pass active filter circuit unit is set to F = 1 / (2*Π*R40*C11) ≈ 10KHz, which can effectively filter out mid-to-high frequency noise generated by the circuit. In addition, the output terminal of the third operational amplifier of this low-pass active filter circuit unit is connected to diodes VD22 and VD23 to form a voltage clamping circuit, which effectively protects the ADC port of the CPU. The CPU adjusts the brightness of the display screen according to the output signal of the low-pass active filter circuit unit.

[0026] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A domestically developed automatic brightness adjustment system for display screens, characterized in that: It includes a primary transimpedance amplifier circuit unit, a fixed gain amplifier circuit unit, a low-pass active filter circuit unit, a CPU, and a display screen; The primary transimpedance amplifier circuit unit has its input terminal connected to a photodiode on the light guide plate of the display screen; the fixed gain amplifier circuit unit has its input terminal connected to the output terminal of the primary transimpedance amplifier circuit unit; the low-pass active filter circuit unit has its input terminal connected to the output terminal of the fixed gain amplifier circuit unit, and its output terminal connected to the ADC port of the CPU. The low-pass active filter circuit unit includes a low-pass filter network and a voltage clamping circuit; the CPU is connected to the display screen to adjust the brightness of the display screen according to the acquired output signal of the low-pass active filter circuit unit.

2. The automatic brightness adjustment system for a display screen according to claim 1, characterized in that: The primary transimpedance amplifier circuit unit, the fixed gain amplifier circuit unit, and the low-pass active filter circuit unit all use the domestically produced SGM8425AYN5G / TR chip.

3. The automatic brightness adjustment system for a display screen according to claim 1, characterized in that: The primary transimpedance amplifier circuit unit includes a first operational amplifier, which uses a domestically produced SGM8425AYN5G / TR chip. The inverting input terminal -IN of the first operational amplifier is connected to the negative terminal of a photodiode through a resistor R37; the non-inverting input terminal +IN of the first operational amplifier is connected to the positive terminal of the photodiode through a resistor R35, and then connected to GND through a resistor R34; the output terminal of the first operational amplifier is connected to the inverting input terminal -IN of the first operational amplifier through a resistor R38. The resistor R38 serves as a negative feedback resistor, and a capacitor C9 is connected in parallel with the negative feedback resistor R38 to form a phase compensation circuit.

4. The automatic brightness adjustment system for a display screen according to claim 1, characterized in that: The fixed gain amplifier circuit unit includes a second operational amplifier, which uses a domestically produced SGM8425AYN5G / TR chip. The non-inverting input terminal +IN of the second operational amplifier is connected to the output terminal of the first operational amplifier of the primary transimpedance amplifier circuit unit through resistor R36. The inverting input terminal -IN of the second operational amplifier is connected to the output terminal of the second operational amplifier through resistor R41, and the inverting input terminal -IN of the second operational amplifier is connected to GND through resistor R44.

5. The automatic brightness adjustment system for a display screen according to claim 1, characterized in that: The low-pass active filter circuit unit includes a third operational amplifier, which uses a domestically produced SGM8425AYN5G / TR chip. The non-inverting input terminal +IN of the third operational amplifier is connected to the output terminal of the second operational amplifier in the fixed gain amplifier circuit unit through resistor R40. The non-inverting input terminal +IN of the third operational amplifier is also connected to the output terminal of the third operational amplifier through resistor R40 and capacitor C5. The non-inverting input terminal +IN of the third operational amplifier is also connected to GND through capacitor C11, together forming a low-pass filter network. The output terminal of the third operational amplifier in this low-pass active filter circuit unit is connected to diodes VD22 and VD23 to form a voltage clamping circuit.

Images