CN-115655466-B - Photoelectric detection circuit and display device

CN115655466BCN 115655466 BCN115655466 BCN 115655466BCN-115655466-B

Abstract

The invention provides a photoelectric detection circuit and a display device, wherein an auxiliary light-sensing transistor which is in the same illumination environment condition as a main light-sensing transistor is arranged in the photoelectric detection circuit, and the threshold voltage of the auxiliary light-sensing transistor is grabbed and compensated to the grid electrode of the main light-sensing transistor through a first threshold grabbing compensation unit, so that the influence of the deviation of the threshold voltage of the main light-sensing transistor on a photoelectric signal generated by the main light-sensing transistor can be reduced, the condition of distortion of the output photoelectric signal caused by characteristic drift of the main light-sensing transistor is improved, and the detection precision of the photoelectric detection circuit is further improved.

Inventors

JIN HUIJUN

Assignees

上海中航光电子有限公司

Dates

Publication Date: 20260512
Application Date: 20220927

Claims (13)

1. A photo-detection circuit, comprising: the first end of the main light sensing transistor is electrically connected with the first fixed voltage end, and the second end of the main light sensing transistor is used for outputting photoelectric signals; the auxiliary light-sensing transistor and the main light-sensing transistor are both positioned in the same illumination environment condition; The first threshold grabbing compensation unit is electrically connected with the main light sensing transistor and the auxiliary light sensing transistor, the first threshold grabbing compensation unit is electrically connected with the grid electrode, the first end and the second end of the auxiliary light sensing transistor, the first threshold grabbing compensation unit is electrically connected with the grid electrode of the main light sensing transistor, and the first threshold grabbing compensation unit is used for acquiring the threshold voltage of the auxiliary light sensing transistor and compensating the threshold voltage of the auxiliary light sensing transistor to the grid electrode of the main light sensing transistor; The first threshold grabbing compensation unit comprises a first charging module, a first grabbing compensation module and a first output control module, wherein the grid electrode of the main light sensing transistor and the grid electrode of the auxiliary light sensing transistor are electrically connected to a first node; The first end of the first charging module is electrically connected with a second fixed voltage end, the second end of the first charging module is electrically connected with the first node, and the first charging module is used for responding to a first control signal to control the second fixed voltage end to charge the first node; The first grabbing compensation module is electrically connected with the first node, the first grabbing compensation module is electrically connected with the first end of the auxiliary light sensing transistor and the second end of the auxiliary light sensing transistor and the third node, and the first grabbing compensation module is used for responding to a second control signal to control the charged first node to discharge through the auxiliary light sensing transistor until the potential of the first node is the sum of the potential at the third node and the threshold voltage of the auxiliary light sensing transistor; The first output control module is electrically connected with the first node, the second node, the third node and the first fixed voltage end, and is used for responding to a third control signal, controlling the first fixed voltage end and the auxiliary light sensing transistor to form a passage after the potential of the first node is the sum of the potential of the third node and the threshold voltage of the auxiliary light sensing transistor, and controlling the first fixed voltage end and the main light sensing transistor to form a passage at the same time so as to output the photoelectric signal.
2. The photodetection circuit according to claim 1, wherein the first charging module comprises a first transistor, a first end of the first transistor is electrically connected to the second fixed voltage end, a second end of the first transistor is electrically connected to the first node, and a gate of the first transistor is connected to the first control signal; The first grabbing compensation module comprises a second transistor and a third transistor; the first end of the second transistor is electrically connected with the first node, the second end of the second transistor is electrically connected with the second node, and the grid electrode of the second transistor is connected with the second control signal; the first end of the third transistor is electrically connected with the third node, the second end of the third transistor is electrically connected with a third fixed voltage end, and the grid electrode of the third transistor is connected with the second control signal; The first output control module comprises a fourth transistor, a fifth transistor and a first capacitor, wherein a first end of the fourth transistor is electrically connected with the first fixed voltage end, a second end of the fourth transistor is electrically connected with the second node, a grid electrode of the fourth transistor is connected with the third control signal, a first end of the fifth transistor is electrically connected with the third node, a second end of the fifth transistor is electrically connected with the third fixed voltage end, a grid electrode of the fifth transistor is connected with the third control signal, a first end of the first capacitor is electrically connected with the first node, and a second end of the first capacitor is connected with the third control signal.
3. The photodetection circuit according to claim 1, wherein the first fixed voltage terminal and the second fixed voltage terminal are the same fixed voltage terminal; Or the absolute value of the output voltage of the second fixed voltage end is smaller than that of the first fixed voltage end.
4. The photo detection circuit of claim 1, wherein the first threshold capture compensation unit further comprises a first voltage division module electrically connected to the third node, the first voltage division module configured to transmit a first preset voltage to the third node in response to the second control signal.
5. The photodetection circuit according to claim 4, wherein the first voltage dividing module comprises a first resistor, a sixth transistor, and a seventh transistor; The first end of the first resistor is electrically connected with the voltage division voltage end, and the second end of the first resistor is electrically connected with the first voltage division node; the first end of the sixth transistor is electrically connected with the first voltage division node, the second end of the sixth transistor is electrically connected with a third fixed voltage end, and the grid electrode of the sixth transistor is electrically connected with a fourth control signal; The first end of the seventh transistor is electrically connected with the first voltage division node, the second end of the seventh transistor is electrically connected with the third node, and the grid electrode of the seventh transistor is connected with the second control signal.
6. The photodetection circuit according to claim 5, wherein the divided voltage terminal and the first fixed voltage terminal are the same voltage terminal, and/or the fourth control signal corresponding port and the first fixed voltage terminal are the same voltage terminal; or the voltage division voltage end and the corresponding port of the second control signal are the same port, and/or the corresponding port of the fourth control signal and the corresponding port of the second control signal are the same port.
7. The photo-detection circuit of any one of claims 1-6, wherein the photo-detection circuit further comprises: The first end of the main transistor is electrically connected with a preset voltage end, and the second end of the main transistor is used for outputting a reference signal; the auxiliary transistor and the main transistor are both positioned in a non-illumination environment condition; The second threshold grabbing compensation unit is electrically connected with the main transistor and the auxiliary transistor, and is used for acquiring the threshold voltage of the auxiliary transistor and compensating the threshold voltage of the auxiliary transistor to the grid electrode of the main transistor.
8. The photo detection circuit of claim 7, wherein the predetermined voltage terminal and the first fixed voltage terminal are the same voltage terminal; Or the preset voltage end and the port corresponding to the third control signal are the same port.
9. The photodetection circuit according to claim 7, wherein the first threshold grabbing compensation unit comprises the first charging module, the first grabbing compensation module, and the first output control module, wherein the second threshold grabbing compensation unit comprises a second charging module, a second grabbing compensation module, and a second output control module, and wherein the gate of the main transistor and the gate of the auxiliary transistor are each electrically connected to a fourth node; The first end of the second charging module is electrically connected with the second fixed voltage end, the second end of the second charging module is electrically connected with the fourth node, and the second charging module is used for responding to the first control signal to control the second fixed voltage end to charge the fourth node; the second grabbing compensation module is electrically connected with the fourth node, the second grabbing compensation module is electrically connected with the first end of the auxiliary transistor and the fifth node, the second grabbing compensation module is electrically connected with the second end of the auxiliary transistor and the sixth node, and the second grabbing compensation module is used for responding to the second control signal and controlling the charged fourth node to discharge through the auxiliary transistor until the potential of the fourth node is the sum of the potential at the sixth node and the threshold voltage of the auxiliary transistor; the second output control module is electrically connected with the fourth node, the fifth node, the sixth node and the first fixed voltage end, and is used for responding to the third control signal, and controlling the first fixed voltage end and the auxiliary transistor to form a channel after the potential of the fourth node is the sum of the potential of the sixth node and the threshold voltage of the auxiliary transistor, and simultaneously controlling the preset voltage end and the main transistor to form a channel to output the photoelectric signal.
10. The photodetection circuit according to claim 9, wherein the second charging module comprises an eighth transistor, a first end of the eighth transistor being electrically connected to the second fixed voltage end, a second end of the eighth transistor being electrically connected to the fourth node, a gate of the eighth transistor being connected to the first control signal; the second grabbing compensation module comprises a ninth transistor and a tenth transistor; a first end of the ninth transistor is electrically connected with the fourth node, a second end of the ninth transistor is electrically connected with the fifth node, and a grid electrode of the ninth transistor is connected with the second control signal; the first end of the tenth transistor is electrically connected with the sixth node, the second end of the tenth transistor is electrically connected with a third fixed voltage end, and the grid electrode of the tenth transistor is connected with the second control signal; The second output control module comprises an eleventh transistor, a twelfth transistor and a second capacitor, wherein a first end of the eleventh transistor is electrically connected with the first fixed voltage end, a second end of the eleventh transistor is electrically connected with the fifth node, a grid electrode of the eleventh transistor is connected with the third control signal, a first end of the twelfth transistor is electrically connected with the sixth node, a second end of the twelfth transistor is electrically connected with the third fixed voltage end, a grid electrode of the twelfth transistor is connected with the third control signal, a first end of the second capacitor is electrically connected with the fourth node, and a second end of the second capacitor is connected with the third control signal.
11. The photo detection circuit of claim 9, wherein the first threshold grab compensation unit further comprises a first voltage division module electrically connected to the third node, the first voltage division module configured to transmit a first preset voltage to the third node in response to the second control signal, wherein the second threshold grab compensation unit further comprises a second voltage division module configured to transmit a second preset voltage to the sixth node in response to the second control signal.
12. The photodetection circuit of claim 11, wherein the first voltage dividing module comprises a first resistor, a sixth transistor and a seventh transistor, wherein a first end of the first resistor is electrically connected with a voltage dividing voltage end, a second end of the first resistor is electrically connected with a first voltage dividing node, a first end of the sixth transistor is electrically connected with the first voltage dividing node, a second end of the sixth transistor is electrically connected with a third fixed voltage end, a gate of the sixth transistor is electrically connected with a fourth control signal, a first end of the seventh transistor is electrically connected with the first voltage dividing node, a second end of the seventh transistor is electrically connected with the third node, and a gate of the seventh transistor is connected with the second control signal, wherein the second voltage dividing module comprises a second resistor, a voltage dividing light sensing transistor and a thirteenth transistor; The first end of the second resistor is electrically connected with the voltage division voltage end, and the second end of the second resistor is electrically connected with a second voltage division node; The first end of the voltage division light sensing transistor is electrically connected with the second voltage division node, the second end of the voltage division light sensing transistor is electrically connected with the third fixed voltage end, the grid electrode of the voltage division light sensing transistor is electrically connected with the fourth control signal, and the voltage division light sensing transistor, the auxiliary light sensing transistor and the main light sensing transistor are all positioned in the same illumination environment condition; The first end of the thirteenth transistor is electrically connected with the second voltage division node, the second end of the thirteenth transistor is electrically connected with the sixth node, and the grid electrode of the thirteenth transistor is connected with the second control signal.
13. A display device comprising a photodetection circuit according to any one of claims 1-12.

Description

Photoelectric detection circuit and display device Technical Field The invention relates to the technical field of photoelectric detection, in particular to a photoelectric detection circuit and a display device. Background At present, in a photoelectric detection circuit in an existing display device, a light sensing transistor for converting illumination intensity into a photoelectric signal is generally connected with an analysis processing circuit, wherein the light sensing transistor generates a photoelectric signal according to the illumination intensity and outputs the photoelectric signal, and then the analysis processing circuit detects the photoelectric signal to determine the current illumination intensity. However, the existing light-sensitive transistor is irradiated for a long time and a direct current bias voltage is applied for a long time, so that the characteristic drift is caused, and the photoelectric signal output by the light-sensitive transistor is distorted, so that the detection precision of the photoelectric detection circuit is low. Disclosure of Invention In view of the above, the invention provides a photoelectric detection circuit and a display device, which effectively solve the existing technical problems, improve the distortion of the output photoelectric signal caused by the characteristic drift of the main light-sensing transistor, and further improve the detection precision of the photoelectric detection circuit. In order to achieve the above purpose, the technical scheme provided by the invention is as follows: a photo detection circuit comprising: the first end of the main light sensing transistor is electrically connected with the first fixed voltage end, and the second end of the main light sensing transistor is used for outputting photoelectric signals; the auxiliary light-sensing transistor and the main light-sensing transistor are both positioned in the same illumination environment condition; And the first threshold grabbing compensation unit is electrically connected with the main light sensing transistor and the auxiliary light sensing transistor, and is used for acquiring the threshold voltage of the auxiliary light sensing transistor and compensating the threshold voltage of the auxiliary light sensing transistor to the grid electrode of the main light sensing transistor. Correspondingly, the invention also provides a display device which comprises the photoelectric detection circuit. Compared with the prior art, the technical scheme provided by the invention has at least the following advantages: The invention provides a photoelectric detection circuit and a display device, comprising a main light-sensing transistor, an auxiliary light-sensing transistor and a first threshold grabbing compensation unit, wherein the first end of the main light-sensing transistor is electrically connected with a first fixed voltage end, the second end of the main light-sensing transistor is used for outputting photoelectric signals, the auxiliary light-sensing transistor and the main light-sensing transistor are both positioned in the same illumination environment condition, and the first threshold grabbing compensation unit is electrically connected with the main light-sensing transistor and the auxiliary light-sensing transistor, and is used for acquiring the threshold voltage of the auxiliary light-sensing transistor and compensating the threshold voltage of the auxiliary light-sensing transistor to the grid electrode of the main light-sensing transistor. As can be seen from the above, according to the technical solution provided by the present invention, an auxiliary light sensing transistor is disposed in the light detection circuit under the same illumination environment condition as the main light sensing transistor, and the threshold voltage of the auxiliary light sensing transistor is captured and compensated to the gate of the main light sensing transistor by the first threshold capturing compensation unit, so that the influence of the deviation of the threshold voltage of the main light sensing transistor on the generated photoelectric signal of the main light sensing transistor can be reduced, the distortion of the output photoelectric signal caused by the characteristic drift of the main light sensing transistor is improved, and the detection precision of the light detection circuit is further improved. Drawings In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art. Fig. 1 is a schematic structural diagram of a photoelectric detect