A photosensitive detection device and a display terminal

Abstract

The present invention provides a photosensitive detection device and a display terminal applied in the field of display technology. In the photosensitive detection device, the power supply module includes a control unit and a processing unit connected to each other to output the first voltage, the second voltage and the third voltage ; The detection module is connected to the power supply module, including a first bridge arm and a second bridge arm connected in parallel to receive the first voltage, the second voltage and the third voltage, the upper switching tube of the first bridge arm and the second bridge arm The lower switching tube of the arm is a photosensitive switching tube, the midpoint of the first bridge arm outputs a first detection signal, and the midpoint of the second bridge arm outputs a second detection signal; the working cycle of the photosensitive detection device includes a first period and a second period, the first voltage is higher than the second voltage during the first period, and lower than the second voltage during the second period. The light-sensing detection device and display terminal provided by the invention can reduce light-sensing errors, enhance device stability, and improve the sensitivity of the automatic backlight system of the display terminal.

Description

technical field [0001] The present invention relates to the field of display technology, in particular to a photosensitive detection device and a display terminal. Background technique [0002] In the existing automatic backlight adjustment system of a display terminal, the light sensing structure adopts a differential structure to improve the sensitivity and linearity of the detection result and enhance the anti-interference ability. In the use of this photo-sensing structure, the bias voltage of the differential circuit is a DC voltage. Due to the mechanism of charge trapping, the threshold voltage of the transistor device will drift with the increase of the gate biasing time, and the transfer characteristic curve will change. The overall offset, the direction of the offset is related to the polarity of the gate voltage, and the variation of the threshold voltage has a logarithmic relationship with the gate pressurization time, which leads to the error of the light sensing...

AI Technical Summary

Problems solved by technology

In the use of this photo-sensing structure, the bias voltage of the differential circuit is a DC voltage. Due to the mechanism of charge trapping, the threshold voltage of the transistor device will drift with the increase of the gate biasing time, and the transfer characteristic curve will change. The overall offset, the direction of the offset is related to the polarity of the gate voltage, and the variation of the threshold voltage has a logarithmic relationship with the gate pressurization time, which leads to the error of the light sensing signal. In the actual test, it is found that the deviation of 24 hours is within 15 -25% or so

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