CN-224203825-U - Display screen brightness automatic regulating system based on localization

CN224203825UCN 224203825 UCN224203825 UCN 224203825UCN-224203825-U

Abstract

The utility model discloses a home-made display screen brightness automatic regulating system which comprises a primary transimpedance amplifier circuit unit, a fixed gain amplifier circuit unit and a low-pass active filter circuit unit, wherein the primary transimpedance amplifier circuit unit is an amplifying circuit for detecting a photodiode, the primary transimpedance amplifier circuit unit is used for converting input current into output voltage through a negative feedback loop to realize primary photoelectric conversion of ambient light, the fixed gain amplifier circuit unit is used for further amplifying the output voltage of the primary transimpedance amplifier circuit unit, 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 3.3V while filtering high-frequency interference in the circuit so as to protect an ADC port of a CPU, the CPU is connected with a display screen, and the CPU regulates the brightness of the display screen according to the acquired output signal of the low-pass active filter circuit unit. The utility model solves the secondary problems of interference, self-excitation and the like caused by adopting domestic devices.

Inventors

WANG XIN
YANG XUDONG
FENG YU
ZHANG HAOMING

Assignees

天津振通电子有限公司

Dates

Publication Date: 20260505
Application Date: 20250514

Claims (5)

1. The display screen brightness automatic regulating system based on localization is characterized by comprising 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 low-pass active filter circuit comprises a primary transimpedance amplifier circuit unit, a fixed gain amplifier circuit unit, a low-pass active filter circuit unit, an ADC (analog to digital converter) port of a CPU (Central processing Unit), wherein the input end of the primary transimpedance amplifier circuit unit is connected with a photosensitive diode on a light guide plate of the display screen, the input end of the fixed gain amplifier circuit unit is connected with the output end of the primary transimpedance amplifier circuit unit, the input end of the low-pass active filter circuit unit is connected with the output end of the fixed gain amplifier circuit unit, the output end of the low-pass active filter circuit unit is connected to the ADC port of the CPU, the low-pass active filter circuit unit comprises a low-pass filter network and a voltage clamping circuit, and the CPU is connected with the display screen and is used for adjusting the brightness of the display screen according to the acquired output signals of the low-pass active filter circuit unit.
2. The system for automatically adjusting the brightness of a display screen according to claim 1, wherein the primary transimpedance amplifier circuit unit, the fixed gain amplifier circuit unit and the low-pass active filter circuit unit are all manufactured by using a domestic SGM8425AYN G/TR chip.
3. The automatic brightness adjusting system of display screen according to claim 1, wherein the primary transimpedance amplifier circuit unit comprises a first operational amplifier, the first operational amplifier adopts a domestic SGM8425AYN G/TR chip, the reverse input end-IN of the first operational amplifier is connected with the cathode of the photosensitive diode through a resistor R37, the non-inverting input end +IN of the first operational amplifier is connected with the anode of the photosensitive diode through a resistor R35 and is connected with GND through a resistor R34, the output end of the first operational amplifier is connected with the reverse input end-IN of the first operational amplifier through a resistor R38, the resistor R38 is used as a negative feedback resistor, and a capacitor C9 is connected IN parallel with the negative feedback resistor R38 to form a phase compensating circuit.
4. The system for automatically adjusting brightness of display screen according to claim 1, wherein the fixed gain amplifier circuit unit comprises a second operational amplifier, the second operational amplifier is a domestic SGM8425AYN G/TR chip, the non-inverting input +IN of the second operational amplifier is connected with the output end of the first operational amplifier of the primary transimpedance amplifier circuit unit through a resistor R36, the inverting input-IN of the second operational amplifier is connected with the output end of the second operational amplifier through a resistor R41, and the inverting input-IN of the second operational amplifier is connected with GND through a resistor R44.
5. The system of claim 1, wherein the low-pass active filter circuit unit comprises a third operational amplifier, the third operational amplifier is a domestic SGM8425AYN G/TR chip, the non-inverting input terminal +IN of the third operational amplifier is connected with the output terminal of the second operational amplifier of the fixed gain amplifier circuit unit through a resistor R40, the non-inverting input terminal +IN of the third operational amplifier is connected with the output terminal of the third operational amplifier through a resistor R40 and a capacitor C5, the non-inverting input terminal +IN of the third operational amplifier is connected with GND through a capacitor C11 to form a low-pass filter network together, and the output terminal of the third operational amplifier of the low-pass active filter circuit unit is connected with a diode VD22 and a diode VD23 to form a voltage clamping circuit.

Description

Display screen brightness automatic regulating system based on localization Technical Field The utility model belongs to the technical field of display screen systems, and particularly relates to a display screen brightness automatic adjusting system based on localization. Background In the flight process of the aircraft, the brightness change and speed of the environment irradiated on the display screen are fast under the influence of the flight attitude and the high-altitude environment, so that the brightness on the display screen is suddenly and suddenly changed, the visual fatigue of a pilot can be caused, the information displayed on the display screen can not be clearly observed, and the flight safety accident can be caused more seriously. The operator can definitely burden the operator by means of manually and frequently adjusting the brightness adjusting knob or the key on the display screen, and the operator is quite unrealistic. Therefore, in order to ensure that pilots and staff in the same class can clearly observe display information in dynamic and static environments, the brightness of the display is required to be correspondingly and automatically adjusted along with the change of the environment light outside the cockpit. In a traditional automatic brightness adjusting system of an onboard display, a photosensitive assembly and an acquisition circuit of the automatic brightness adjusting system are often dependent on an import scheme. With the adoption of various limiting measures for the coming-out of the electronic industry in China in the foreign world in recent years, the domestic semiconductor industry is gradually rising in recent years, but the domestic environment light sensor corresponding to the domestic environment light sensor is not high enough in integration level, a transimpedance amplifier is required to be externally added to realize photoelectric conversion, so that secondary problems such as self-excitation and interference of a circuit are often brought, meanwhile, most of the domestic amplifier is a linear device and cannot be completely matched with optical nonlinearity, and a special algorithm is required to convert in the middle acquisition and brightness adjustment links. Based on the actual situation, the utility model designs a domestic automatic brightness adjustment system scheme for the display screen, which effectively solves the secondary problems of self excitation, interference and the like caused by using domestic devices while finishing the traditional automatic brightness adjustment function of the airborne display screen. Disclosure of utility model The utility model aims to provide a display screen brightness automatic regulating system based on localization, which solves the secondary problems of interference, self-excitation and the like caused by adopting localization devices, has the characteristics of low noise, low delay, high sensitivity and the like, and realizes the display brightness automatic regulating function. The utility model is realized by the following technical scheme: A display screen brightness automatic regulating system based on localization comprises 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 LED display screen comprises a primary transimpedance amplifier circuit unit, a fixed gain amplifier circuit unit, a low-pass active filter circuit unit, a CPU (Central processing Unit) and a voltage clamping circuit, wherein the input end of the primary transimpedance amplifier circuit unit is connected with a photosensitive diode on a light guide plate of the display screen, the input end of the fixed gain amplifier circuit unit is connected with the output end of the primary transimpedance amplifier circuit unit, the input end of the low-pass active filter circuit unit is connected with the output end of the fixed gain amplifier circuit unit, the output end of the low-pass active filter circuit unit is connected to an ADC (analog-to-digital converter) port of the CPU, the low-pass active filter circuit unit comprises a low-pass filter network and the voltage clamping circuit, the CPU is connected with the display screen, and the CPU adjusts the brightness of the display screen according to the acquired output signals of the low-pass active filter circuit unit. In the above technical scheme, the primary transimpedance amplifier circuit unit, the fixed gain amplifier circuit unit and the low-pass active filter circuit unit all adopt domestic SGM8425AYN G/TR chips. IN the technical scheme, the primary transimpedance amplifier circuit unit comprises a first operational amplifier, wherein the first operational amplifier adopts a domestic SGM8425AYN G/TR chip, the reverse input end-IN of the first operational amplifier is connected with the cathode of a photosensitive diode through a resistor R37, the IN-phase input end +IN of the