CN114612949A

CN114612949A - Photoelectric detection circuit, driving method thereof, display panel and display device

Info

Publication number: CN114612949A
Application number: CN202210251426.9A
Authority: CN
Inventors: 盖人荣; 张�浩; 王晶
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2022-03-15
Filing date: 2022-03-15
Publication date: 2022-06-10

Abstract

According to the photoelectric detection circuit, the driving method thereof, the display panel and the display device, the driving control circuit and the output control circuit are matched with each other, amplified detection current can be generated according to an electric signal converted by the photoelectric conversion device, and therefore the definition of an obtained fingerprint picture is improved, and accuracy of fingerprint identification is improved.

Description

Photoelectric detection circuit, driving method thereof, display panel and display device

Technical Field

The present disclosure relates to the field of display technologies, and in particular, to a photodetection circuit, a driving method thereof, a display panel, and a display device.

Background

Fingerprint detection and identification have been widely used as means for identity authentication, and are almost one of the necessary functions in electronic devices such as mobile phones and tablet computers. Common fingerprint detection modes include capacitive fingerprint detection, optical fingerprint detection, ultrasonic detection and the like, wherein the optical fingerprint detection is the current mainstream trend.

Disclosure of Invention

The photoelectric detection circuit that this disclosed embodiment provided includes:

a photoelectric conversion device configured to convert a received optical signal into an electrical signal;

a drive control circuit coupled to the photoelectric conversion device and configured to generate a detection current according to a signal of a detection control signal terminal and an electrical signal converted by the photoelectric conversion device;

an output control circuit coupled to the drive control circuit and configured to output the detection current to a detection terminal in response to a signal of a detection scan signal terminal.

In some examples, the drive control circuit includes:

a control circuit coupled to the first switching electrode of the photoelectric conversion device and configured to pull down the voltage of the first switching electrode in response to a signal of the detection control signal terminal;

a driving circuit coupled to the first conversion electrode of the photoelectric conversion device, configured to perform threshold compensation in response to a signal of a detection compensation signal terminal, and generate a detection current according to the electric signal.

In some examples, the control circuit includes: a capacitor;

the first electrode plate of the capacitor is coupled with the detection control signal end, and the second electrode plate of the capacitor is coupled with the first conversion electrode.

In some examples, the drive circuit includes: a detection drive transistor and a detection compensation transistor;

the gate of the detection driving transistor is coupled with the first conversion electrode, the first electrode of the detection driving transistor is coupled with a first power supply end, and the second electrode of the detection driving transistor is coupled with the output control circuit;

the gate of the detection compensation transistor is coupled to the detection compensation signal terminal, the first pole of the detection compensation transistor is coupled to the first pole of the detection driving transistor, and the second pole of the detection compensation transistor is coupled to the second pole of the detection driving transistor.

In some examples, the output control circuit includes: detecting the scanning transistor;

the gate of the scan detection transistor is coupled to the scan detection signal terminal, the first pole of the scan detection transistor is coupled to the driving circuit, and the second pole of the scan detection transistor is coupled to the detection terminal.

The display panel provided by the embodiment of the disclosure comprises the photoelectric detection circuit.

In some examples, the display panel further comprises a substrate base plate, a plurality of the photodetecting units and a plurality of the light emitting sub-pixels located in a display region of the substrate base plate; wherein the orthographic projection of the light-emitting sub-pixel on the substrate base plate and the orthographic projection of the photoelectric detection unit on the substrate base plate do not overlap;

the light emitting sub-pixel comprises a light emitting device;

the photodetection unit includes the photodetection circuit.

In some examples, the first conversion electrode of the photoelectric conversion device and the first light emitting electrode of the light emitting device are arranged in the same layer and material;

and/or the second conversion electrode of the photoelectric conversion device and the second light-emitting electrode of the light-emitting device are arranged in the same layer and material.

In some examples, the light emitting sub-pixel further includes a driving circuit that drives the light emitting device to emit light;

the grid electrode of the transistor in the photoelectric detection circuit and the grid electrode of the transistor in the driving circuit are arranged in the same layer and material;

and/or the active layer of the transistor in the photoelectric detection circuit and the active layer of the transistor in the driving circuit are arranged in the same layer and material;

and/or the source and drain electrodes of the transistor in the photoelectric detection circuit and the source and drain electrodes of the transistor in the driving circuit are arranged in the same layer and material.

The display device provided by the embodiment of the disclosure comprises the display panel.

In some examples, the display device further includes: detecting a chip; the detection chip comprises a data processing circuit and a plurality of signal transmission circuits;

the detection ends of a row of the photoelectric detection circuits are coupled with one signal transmission circuit, and the signal transmission circuit is configured to process the received detection current to obtain a target detection signal and send the target detection signal to the data processing circuit;

the data processing circuit is configured to perform fingerprint detection and identification according to the target detection signal transmitted by the signal transmission circuit.

The driving method for the above-mentioned photodetection circuit provided by the embodiment of the present disclosure includes:

a first stage, loading a signal with a first voltage to the detection control signal end;

a second stage, loading a signal with a second voltage to the detection control signal end, converting the received optical signal into an electrical signal by the photoelectric conversion device, receiving the electrical signal by the drive control circuit, and generating a detection current according to the electrical signal; the output control circuit responds to a signal of a detection scanning signal end and outputs the detection current to a detection end;

wherein the first voltage is greater than the second voltage.

In some examples, the first stage comprises:

and in the reset compensation stage, a signal with a first level is loaded on the detection compensation signal end, a signal with a first level is loaded on the detection scanning signal line, and a signal with the first voltage is loaded on the detection control signal end.

In some examples, the second stage includes:

in the conversion stage, a signal with a second level is loaded on the detection compensation signal end, a signal with a first level is loaded on the detection scanning signal line, and a signal with the second voltage is loaded on the detection control signal end;

and in the output stage, a signal with a second level is loaded on the detection compensation signal end, a signal with the second level is loaded on the detection scanning signal line, and a signal with the second voltage is loaded on the detection control signal end.

Drawings

FIG. 1 is a schematic diagram of some configurations of a photodetection circuit in an embodiment of the present disclosure;

FIG. 2 is another schematic diagram of a photodetection circuit according to an embodiment of the present disclosure;

FIG. 3 is a diagram illustrating some specific structures of a photodetection circuit according to an embodiment of the present disclosure;

FIG. 4 is a flow chart of some driving methods of the photodetection circuit in the disclosed embodiment;

FIG. 5 is a timing diagram of some signals in an embodiment of the present disclosure;

FIG. 6 is a schematic top view of a display panel according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of some partial cross-sectional structures of a display panel in an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of some structures of a display device in an embodiment of the present disclosure;

FIG. 9 is another schematic structural diagram of a display device according to an embodiment of the disclosure;

fig. 10 is a schematic view of some structures of the display device in the embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure will be described clearly and completely with reference to the drawings of the embodiments of the present disclosure. It is to be understood that the described embodiments are only a few embodiments of the present disclosure, and not all embodiments. And the embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the disclosure without any inventive step, are within the scope of protection of the disclosure.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

It should be noted that the sizes and shapes of the various figures in the drawings are not to scale, but are merely intended to illustrate the present disclosure. And the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

In order to improve the integration level of the display panel, a photoelectric detection circuit for optical fingerprint identification can be integrated in the screen of the display panel, so that the fingerprint identification function can be realized in the display area. However, the current photoelectric detection circuit has large circuit noise and low signal-to-noise ratio (SNR) (for example, SNR is 12.6db under four times of gain) due to unstable threshold voltage, so that the obtained fingerprint image is blurred, and the accuracy of fingerprint identification is reduced.

As shown in fig. 1, the photodetection circuit provided in the embodiment of the present disclosure includes:

a photoelectric conversion device 10 configured to convert a received optical signal into an electrical signal;

a drive control circuit 20 coupled to the photoelectric conversion device 10 and configured to generate a detection current according to a signal of the detection control signal terminal CS and an electrical signal converted by the photoelectric conversion device 10;

the output control circuit 30, coupled to the driving control circuit 20, is configured to output the probing current to the probing terminal VO in response to the signal of the probing scan signal terminal GA.

The photoelectric detection circuit provided by the embodiment of the disclosure can generate detection current after amplification according to an electric signal converted by a photoelectric conversion device through the mutual matching of the driving control circuit and the output control circuit, thereby improving the definition of the obtained fingerprint image and further improving the accuracy of fingerprint identification.

In some embodiments of the present disclosure, as shown in fig. 2, the driving control circuit 20 may include: a control circuit 21 and a drive circuit 22; the control circuit 21 is coupled to the first conversion electrode of the photoelectric conversion device 10, and the driving circuit is coupled to the first conversion electrode of the photoelectric conversion device 10. And, the control circuit 21 is configured to pull down the voltage of the first switching electrode in response to a signal of the detection control signal terminal CS. The driving circuit 22 is coupled to the first conversion electrode of the photoelectric conversion device 10, and configured to perform threshold compensation in response to a signal of the detection compensation signal terminal RA and generate a detection current according to the electrical signal.

The photoelectric detection circuit provided by the embodiment of the disclosure can realize threshold value compensation through the mutual matching of the control circuit, the drive circuit and the output control circuit, and avoid the problem of large circuit noise caused by unstable threshold voltage, thereby improving the signal to noise ratio, improving the definition of the obtained fingerprint image and further improving the accuracy of fingerprint identification.

In some embodiments of the present disclosure, as shown in fig. 3, the second conversion electrode of the photoelectric conversion device 10 is coupled to the second power source terminal ELVSS. For example, the first switching electrode may be a positive electrode and the second switching electrode may be a negative electrode. Illustratively, the photoelectric conversion device 10 may be provided as a photodiode. For example, as shown in fig. 3, the photoelectric conversion device 10 may be provided as an organic photodiode OPD. Especially for the organic photodiode, the control circuit and the driving circuit are arranged in the embodiment of the disclosure, and the electric signal converted by the organic photodiode can be amplified and then output to the detection chip for fingerprint detection and identification. In addition, threshold voltage compensation can be realized by the driving circuit, so that the problem of high circuit noise caused by unstable threshold voltage is avoided, the signal to noise ratio can be improved, the definition of the obtained fingerprint picture is improved, and the accuracy of fingerprint identification is improved.

In some embodiments of the present disclosure, as shown in fig. 3, the control circuit 21 may include: a capacitance C0; the first electrode plate of the capacitor C0 is coupled to the detection control signal terminal CS, and the second electrode plate of the capacitor C0 is coupled to the first switching electrode.

In some embodiments of the present disclosure, as shown in fig. 3, the driving circuit 22 may include: a detection drive transistor M1 and a detection compensation transistor M2; the gate of the detecting driving transistor M1 is coupled to the first switching electrode, the first electrode of the detecting driving transistor M1 is coupled to the first power source terminal VDD, and the second electrode of the detecting driving transistor M1 is coupled to the output control circuit 30. And, the gate of the probing compensation transistor M2 is coupled to the probing compensation signal terminal RA, the first pole of the probing compensation transistor M2 is coupled to the first pole of the probing driving transistor M1, and the second pole of the probing compensation transistor M2 is coupled to the second pole of the probing driving transistor M1. Illustratively, the detection driving transistor M1 may be provided as a P-type transistor or an N-type transistor. The detection compensation transistor M2 may be provided as a P-type transistor or an N-type transistor.

In some embodiments of the present disclosure, as shown in fig. 3, the output control circuit 30 may include: the detection scan transistor M3; the gate of the scan detecting transistor M3 is coupled to the scan detecting signal terminal GA, the first pole of the scan detecting transistor M3 is coupled to the driving circuit, and the second pole of the scan detecting transistor M3 is coupled to the detecting terminal VO. Illustratively, the probe scan transistor M3 may be provided as a P-type transistor or an N-type transistor.

Further, in the embodiment of the present disclosure, the P-type transistor is turned off by a high level signal and turned on by a low level signal. The N-type transistor is turned on under the action of a high-level signal and is turned off under the action of a low-level signal.

It should be noted that the transistors mentioned in the above embodiments of the present disclosure may be Low Temperature Polysilicon (LTPS) transistors, and may also be Metal Oxide semiconductor field effect transistors (MOS), which is not limited herein.

It should be noted that, in the embodiment of the present disclosure, as shown in fig. 3, the detection compensation transistor M2 may be configured as an N-type transistor and configured as a MOS transistor, so as to reduce the influence of the leakage current on the gate voltage of the detection driving transistor M1. The detection drive transistor M1 and the detection scan transistor M3 may be provided as P-type transistors and both may be provided as LTPS to improve mobility and may be made thinner and smaller, lower in power consumption, and the like. Therefore, the signal to noise ratio can be further improved, the definition of the obtained fingerprint image is improved, and the accuracy of fingerprint identification is further improved.

In a specific implementation, a first pole of the transistor can be used as a source electrode and a second pole as a drain electrode of the transistor according to the type of the transistor and a signal of a grid electrode of the transistor; or, conversely, the first pole of the transistor is used as the drain thereof, and the second pole is used as the source thereof, which can be designed according to the practical application environment, and is not particularly distinguished herein.

In particular implementation, in the embodiment of the present disclosure, the voltage VDD of the first power source terminal VDD may be a positive value, and the voltage Vss of the second power source terminal ELVSS may be a negative value (e.g., -2.4V). In practical applications, the specific values of the voltage VDD of the first power source terminal VDD and the voltage Vss of the second power source terminal ELVSS may be designed according to practical application environments, and are not limited herein.

The embodiment of the present disclosure further provides a driving method of the above photoelectric detection circuit, as shown in fig. 4, the method may include the following steps:

s100, in the first stage, a signal with a first voltage is loaded on a detection control signal end.

S200, in the second stage, a signal with a second voltage is loaded on a detection control signal end, the photoelectric conversion device converts the received optical signal into an electric signal, and the driving control circuit receives the electric signal and generates a detection current according to the electric signal; the output control circuit outputs a detection current to the detection terminal in response to a signal of the detection scan signal terminal. Wherein the first voltage is greater than the second voltage.

In some embodiments of the present disclosure, the first stage may comprise: and resetting the compensation phase. In the reset compensation stage, a signal with a first level is loaded on the detection compensation signal end, a signal with the first level is loaded on the detection scanning signal line, and a signal with a first voltage is loaded on the detection control signal end.

In some embodiments of the present disclosure, the second stage may include: a conversion phase and an output phase. In the conversion stage, a signal of the second level may be applied to the detection compensation signal terminal, a signal of the first level may be applied to the detection scan signal line, and a signal having the second voltage may be applied to the detection control signal terminal. In the output stage, a signal of the second level may be applied to the detection compensation signal terminal, a signal of the second level may be applied to the detection scanning signal line, and a signal having the second voltage may be applied to the detection control signal terminal.

In some embodiments of the present disclosure, a voltage value of the signal of the first level applied to the probing control signal terminal is greater than a voltage value of the signal of the second level applied to the probing control signal terminal. Illustratively, there may be the formula: vdd + Vth- (Vcs1-Vcs2) < Vss, where Vth represents the threshold voltage of the detection drive transistor (which may be, for example, -1.5V), Vcs1 represents the voltage value of the first voltage of the signal applied to the detection control signal terminal, and Vcs2 represents the voltage value of the second voltage of the signal applied to the detection control signal terminal. In practical applications, the specific voltage value of each signal may be determined according to requirements of practical applications, and is not limited herein.

The following describes the operation process of the above-mentioned photodetection circuit provided in the embodiment of the present disclosure, by taking the driving circuit shown in fig. 3 as an example, and combining with the circuit timing diagram shown in fig. 5. As shown in FIG. 5, ra represents the compensation scan signal terminal, GA represents the signal of the detection scan signal terminal GA, and CS represents the signal of the detection control signal terminal CS. Moreover, the operation of one photodetection circuit 111 in one display frame F0 may include: a first stage T10 and a second stage T20. Wherein the first phase T10 includes a reset compensation phase T11. The second stage T20 includes a transition stage T21 and an output stage T22.

In the reset compensation period T11, the detecting scan transistor M3 is turned off under the control of the high level signal of ga. The detection compensation transistor M2 is turned on under the control of the high level signal of the ra signal, so that the detection driving transistor M1 can be formed in a diode manner, thereby enabling the voltage VDD of the first power source terminal VDD to reset the gate and the second electrode of the detection driving transistor M1, and enabling the voltage of the second electrode plate of the capacitor to be VDD. The detection control signal terminal CS is applied with a signal CS having a first voltage Vcs1, so that the voltage of the first electrode plate of the capacitor is the first voltage Vcs 1. Since the voltage of the first switching electrode of the organic photodiode OPD is higher than the voltage of the second switching electrode. The organic photodiode OPD can be made to form a forward current.

At transition T21, the compensation transistor is turned off under the control of the low level signal of the ra signal. The detection scan transistor M3 is turned off under the control of the high level signal of ga. The detection control signal terminal CS is applied with a signal CS having a second voltage Vcs2, so that the voltage of the first electrode plate of the capacitor jumps from the first voltage Vcs1 to the second voltage Vcs 2. Due to the action of the capacitor, the voltage of the second electrode plate of the capacitor can jump from Vdd + Vth to Vdd + Vth- (Vcs1-Vcs 2). Due to Vdd + Vth- (Vcs1-Vcs2)<Vss can make the organic photodiode OPD generate a reverse current, and when the organic photodiode OPD IS illuminated, a photocurrent can be generated, which can flow into the gate of the detection driving transistor M1, so that the gate voltage of the detection driving transistor M1 IS changed to Vdd + Vth- (Vcs1-Vcs2) + Δ V, so that the detection driving transistor M1 operates in the amplification region, thereby generating the detection current IS. And IS ═ K [ Vdd + Vth- (Vcs1-Vcs2) + Δ V-Vdd-Vth]²＝K[Vcs1-Vcs2)+ΔV]². Where K represents a structural parameter of the detection driving transistor M1. Δ V represents a voltage formed after the photocurrent flows into the gate of the detection drive transistor M1.

In the output stage T22, the compensation transistor is turned off under the control of the low level signal of the ra signal. The probe scan transistor M3 IS turned on under the control of the low signal of ga, so that the detection current IS can be output to the probe terminal VO.

It should be noted that, as can be seen from the formula that the detection current IS satisfies, the detection current IS independent of the threshold voltage of the detection driving transistor M1, so that the problem of unclear fingerprint image due to unstable threshold voltage can be avoided, and the accuracy of fingerprint detection and identification can be further improved.

The embodiment of the disclosure also provides a display panel which comprises the photoelectric detection circuit provided by the embodiment of the disclosure. Illustratively, as shown in fig. 6 and 7, the display panel further includes a substrate 100, and a plurality of photo-detection units 110 and a plurality of light-emitting sub-pixels SPX located in a display area of the substrate 100; wherein the orthographic projection of the light-emitting sub-pixel SPX on the substrate 100 and the orthographic projection of the photo-detection unit 110 on the substrate 100 do not overlap. Also, the light emitting sub-pixel SPX includes a light emitting device, and the photodetection unit 110 includes a photodetection circuit 111. This enables fingerprint detection and identification within the display area of the display panel.

In some embodiments of the present disclosure, each sub-pixel may further include a driving circuit for driving the light emitting device to emit light. For example, the first light emitting electrode 2111 of the light emitting device may be provided as an anode, and the second light emitting electrode 2112 may be provided as a cathode. And, the light emitting device further includes an organic light emitting layer 2113 provided between the first light emitting electrode 2111 and the second light emitting electrode 2112. Further, a hole transport layer and a hole injection layer between the first light emitting electrode 2111 and the organic light emitting layer 2113, and an electron transport layer and an electron injection layer between the second light emitting electrode 2112 and the organic light emitting layer 2113 may be further included. Exemplarily, the Light Emitting device may be configured as an Organic Light Emitting Diode (OLED), a Quantum Dot Light Emitting Diode (QLED), or the like. In addition, the general driving circuit may include a plurality of transistors such as a light emitting driving transistor and a switching transistor, and a storage capacitor, and the specific structure and the operation principle thereof may be the same as those in the prior art, which is not described herein again.

In some embodiments of the present disclosure, as shown in fig. 7, the first conversion electrode 1111 of the photoelectric conversion device 10 and the first light emitting electrode 2111 of the light emitting device may be disposed in the same material layer. Thus, the first conversion electrode 1111 and the first light emitting electrode 2111 can be patterned only by one-time composition process without additionally preparing the first conversion electrode 1111, so that the preparation process can be simplified, the production cost can be saved, and the production efficiency can be improved. It should be noted that each first conversion electrode and each first light-emitting electrode 2111 are disposed at an interval to avoid short circuit.

In some embodiments of the present disclosure, as shown in fig. 7, the second conversion electrode 1112 of the photoelectric conversion device 10 and the second light emitting electrode 2112 of the light emitting device may be disposed in the same material layer. Thus, the second conversion electrode 1112 does not need to be additionally prepared, and the patterns of the second conversion electrode 1112 and the second light-emitting electrode 2112 can be formed only by one-time composition process, so that the preparation process can be simplified, the production cost can be saved, and the production efficiency can be improved. Further, each second conversion electrode and each second light-emitting electrode 2112 may be formed integrally with each other. That is, the conductive layer provided over the entire surface is used as both the second light-emitting electrode 2112 and the second switching electrode.

In some embodiments of the present disclosure, as shown in fig. 7, the photoelectric conversion device 10 may further include an organic photoelectric conversion layer 1113 between the first conversion electrode 1111 and the second conversion electrode 1112. Further, a hole transport layer and a hole injection layer between the first conversion electrode 1111 and the organic photoelectric conversion layer 1113, and an electron transport layer and an electron injection layer between the second conversion electrode 1112 and the organic photoelectric conversion layer 1113 may be further included.

In some embodiments of the present disclosure, as shown in fig. 7, the gate of the transistor 1114 in the photo detection circuit 111 and the gate of the transistor 2114 in the driving circuit may be made of the same material at the same layer. Thus, the grid electrode of the transistor 1114 in the driving circuit and the grid electrode of the transistor 2114 in the photoelectric detection circuit 111 can be formed by only one-time composition process without additionally preparing the grid electrode of the transistor 1114 in the photoelectric detection circuit 111, so that the preparation process can be simplified, the production cost can be saved, and the production efficiency can be improved.

In some embodiments of the present disclosure, as shown in fig. 7, the active layer of the transistor 1114 in the photodetection circuit 111 and the active layer of the transistor 2114 in the driving circuit may be made of the same material. Thus, an additional active layer for preparing the transistor 1114 in the photodetection circuit 111 is not required to be added, and the active layer of the transistor 2114 in the driving circuit and the active layer of the transistor 1114 in the photodetection circuit 111 can be patterned only by one-time composition process, so that the preparation process can be simplified, the production cost can be saved, and the production efficiency can be improved. For example, the active layer of the transistor configured as the LTPS transistor in the electrical detection circuit is the same material as the active layer of the transistor configured as the LTPS transistor in the driving circuit. The active layer of the transistor which is set as the MOS transistor in the electric detection circuit and the active layer of the transistor which is set as the MOS transistor in the driving circuit are arranged in the same layer and material.

In some embodiments of the present disclosure, as shown in fig. 7, the source and drain of the transistor 1114 in the photodetection circuit 111 and the source and drain of the transistor 2114 in the driving circuit may be arranged in the same material in the same layer. Therefore, the source and drain electrodes of the transistor 1114 in the photoelectric detection circuit 111 do not need to be additionally prepared, and the patterns of the source and drain electrodes of the transistor 2114 in the driving circuit and the source and drain electrodes of the transistor 1114 in the photoelectric detection circuit 111 can be formed only by one-time composition process, so that the preparation process can be simplified, the production cost can be saved, and the production efficiency can be improved.

In some embodiments of the present disclosure, the display panel further includes: the device comprises a plurality of detection control lines, a plurality of detection compensation lines, a plurality of detection scanning lines and a plurality of detection transmission lines. The detection control signal end of the photoelectric detection circuit in one row of photoelectric detection units is coupled with one detection control line, the detection compensation signal end of the photoelectric detection circuit in one row of photoelectric detection units is coupled with one detection compensation line, the detection scanning signal end of the photoelectric detection circuit in one row of photoelectric detection units is coupled with one detection scanning line, and the detection end of the photoelectric detection circuit in one column of photoelectric detection units is coupled with one detection transmission line.

The embodiment of the disclosure also provides some display devices, including the display panel provided by the embodiment of the disclosure. The principle of the display device to solve the problem is similar to the display panel, so the implementation of the display device can be referred to the implementation of the display panel, and repeated details are not repeated herein. In specific implementation, in the embodiment of the present disclosure, the display device may be: any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like. Other essential components of the display device are understood by those skilled in the art, and are not described herein nor should they be construed as limiting the present disclosure.

In some embodiments of the present disclosure, as shown in fig. 8, the display device further includes: the detection chip 200, the detection chip 200 may be connected to the display panel by Bonding (Bonding) to implement signal transmission between the detection chip 200 and the display panel. For example, the probing chip 200 may be connected to the flexible circuit board 300 by Bonding (Bonding), and the flexible circuit board 300 may be connected to the display panel by Bonding (Bonding), so as to implement signal transmission between the probing chip 200 and the display panel.

In some embodiments of the present disclosure, as shown in fig. 9, the probing chip 200 may include a data processing circuit 210 and a plurality of signal transmission circuits 220; the detection end VO of one row of the photo-detection circuits 111 is coupled to a signal transmission circuit 220, and the signal transmission circuit 220 is configured to process the received detection current to obtain a target detection signal, and send the target detection signal to the data processing circuit 210. The data processing circuit 210 is configured to perform fingerprint detection and identification based on the target detection signal transmitted by the signal transmission circuit 220. Illustratively, one signal transmission circuit 220 is coupled to the detection terminal VO of one column of photo-detection circuits 111 through one detection transmission line 120.

In some embodiments of the present disclosure, as shown in fig. 10, the signal transmission circuit 220 may include: the circuit comprises a first amplifier OP1, a second amplifier OP2, a first switch K1, a first capacitor C1, a second capacitor C2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and an analog-to-digital converter ADC. A first input terminal of the first amplifier OP1 is coupled to the corresponding probing transmission line 120, a second input terminal of the first amplifier OP1 is coupled to the initialization signal terminal Vinit, and an output terminal of the first amplifier OP1 is coupled to a first terminal of the first resistor R1. A second terminal of the first resistor R1 is coupled to a first terminal of a second resistor R2. A second terminal of the second resistor R2 is coupled to a first input terminal of a second amplifier OP 2. A second input of the second amplifier OP2 is coupled to a first terminal of the fourth resistor R4, an output of the second amplifier OP2 is coupled to an input of the analog-to-digital converter ADC, and an output of the analog-to-digital converter ADC is coupled to the data processing circuit 210. The second terminal of the fourth resistor R4 is coupled to ground. A first terminal of the third resistor R3 is coupled to a first input terminal of the second amplifier OP2, and a second terminal of the third resistor R3 is coupled to an input terminal of the analog-to-digital converter ADC. A first electrode plate of the first capacitor C1 is coupled to a first input terminal of the first amplifier OP1, and a second electrode plate of the first capacitor C1 is coupled to an output terminal of the first amplifier OP 1. The first electrode plate of the second capacitor C2 is coupled to the second terminal of the first resistor R1, and the second electrode plate of the second capacitor C2 is coupled to ground. A first terminal of the first switch K1 is coupled to a first input terminal of the first amplifier OP1, and a second terminal of the first switch K1 is coupled to an output terminal of the first amplifier OP 1.

Illustratively, the detection current output on the transmission line 120 is input to a first input terminal of a first amplifier OP1, and then, through the cooperation of the first amplifier OP1, the second amplifier OP2, the first switch K1, the first capacitor C1, the second capacitor C2, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4, the amplified detection current may be input to an input terminal of the analog-to-digital converter ADC, so that the input terminal of the analog-to-digital converter ADC generates a corresponding analog voltage, and the analog-to-digital converter ADC may convert the generated analog voltage into a digital voltage and then input the digital voltage to the data processing circuit 210. Therefore, the data processing circuit 210 can acquire the digital voltage corresponding to each photoelectric detection unit 110, and further can determine the image of the fingerprint according to the digital voltage, so as to realize fingerprint detection and identification.

It will be apparent to those skilled in the art that various changes and modifications may be made to the present disclosure without departing from the spirit and scope of the disclosure. Thus, if such modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is intended to include such modifications and variations as well.

Claims

1. A photodetection circuit, characterized in that it comprises:

2. The photodetection circuit according to claim 1 wherein said drive control circuit comprises:

3. The photodetection circuit according to claim 2 wherein said control circuit comprises: a capacitor;

4. The photodetection circuit according to claim 2 wherein said driving circuit comprises: a detection drive transistor and a detection compensation transistor;

5. The photodetection circuit according to any of claims 1-4 wherein said output control circuit comprises: detecting the scanning transistor;

6. A display panel comprising the photodetection circuit according to any one of claims 1 to 5.

7. The display panel of claim 6, wherein the display panel further comprises a substrate base, a plurality of the photodetecting units and a plurality of the light emitting sub-pixels located in a display area of the substrate base; wherein the orthographic projection of the light-emitting sub-pixel on the substrate and the orthographic projection of the photoelectric detection unit on the substrate do not overlap;

the light emitting sub-pixel comprises a light emitting device;

the photodetection unit includes the photodetection circuit.

8. The display panel according to claim 7, wherein the first conversion electrode of the photoelectric conversion device and the first light emitting electrode of the light emitting device are provided in the same material in the same layer;

9. The display panel according to claim 8, wherein the light emitting sub-pixel further comprises a driving circuit which drives the light emitting device to emit light;

10. A display device comprising the display panel according to any one of claims 6 to 9.

11. The display device according to claim 10, further comprising: detecting a chip; the detection chip comprises a data processing circuit and a plurality of signal transmission circuits;

12. A driving method for the photodetection circuit according to any one of claims 1 to 5, characterized by comprising:

in the second stage, a signal with a second voltage is loaded on the detection control signal end, the photoelectric conversion device converts the received optical signal into an electric signal, and the drive control circuit receives the electric signal and generates a detection current according to the electric signal; the output control circuit responds to a signal of a detection scanning signal end and outputs the detection current to a detection end;

wherein the first voltage is greater than the second voltage.

13. The driving method of the photodetection circuit according to claim 12, wherein the first stage comprises:

14. The driving method of the photodetection circuit according to claim 12, wherein the second stage comprises: