Pixel circuit, pixel driving method and display device

Abstract

The present invention provides a pixel circuit, a pixel driving method and a display device. The pixel circuit includes a photoelectric sensor, a driving circuit, a storage circuit, a compensation circuit, a first voltage control circuit and an output control circuit. The compensation circuit is electrically connected to the compensation control terminal, the compensation terminal and the first terminal of the driving circuit respectively, and is used to control the connection between the first node and the first terminal of the driving circuit under the control of the compensation control signal provided by the compensation control terminal; the first voltage control circuit controls the writing of the first voltage signal to the second node under the control of the voltage control signal; the output control circuit controls the output of the current signal to the reading line under the control of the reading control signal provided by the reading control terminal. The present invention can eliminate the current error caused by the non-uniformity of the threshold voltage of the driving transistor.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a pixel circuit, a pixel driving method and a display device. Background Art

[0002] When the existing APS (Active Pixel Sensor) pixel circuit is working, the current signal output by the APS (Active Pixel Sensor) pixel circuit is affected by the threshold voltage of the driving transistor due to the uneven threshold voltage of the driving transistor, thereby causing the problem of photoelectric detection error. Summary of the invention

[0003] The main purpose of the present invention is to provide a pixel circuit, a pixel driving method and a display device to solve the problem of photoelectric detection error caused by the current signal output by the existing APS (Active Pixel Sensor) pixel circuit being affected by the threshold voltage of the driving transistor.

[0004] In order to achieve the above object, the present invention provides a pixel circuit, including a photoelectric sensor, a driving circuit, a storage circuit, a compensation circuit, a first voltage control circuit and an output control circuit, wherein:

[0005] The photoelectric sensor is used to convert the received light signal into a corresponding photovoltage signal, and output the photovoltage signal through the photovoltage signal output terminal;

[0006] The control end of the driving circuit is electrically connected to the photovoltage signal output end, the first end of the driving circuit is electrically connected to the output control circuit, the second end of the driving circuit is electrically connected to the first voltage end, and the driving circuit is used to convert the potential of its control end into a corresponding current signal and output the current signal through the first end;

[0007] The first end of the energy storage circuit is electrically connected to the first node, and the second end of the energy storage circuit is electrically connected to the second node; the first node is electrically connected to the control end of the drive circuit; the energy storage circuit is used to store electrical energy;

[0008] The compensation circuit is electrically connected to the compensation control terminal, the first terminal of the drive circuit and the compensation terminal respectively, and is used to control the connection between the compensation terminal and the first terminal of the drive circuit under the control of the compensation control signal provided by the compensation control terminal;

[0009] The first voltage control circuit is electrically connected to the voltage control terminal, the second node and the second terminal of the driving circuit respectively, and is used to control the connection between the second terminal of the driving circuit and the second node under the control of the voltage control signal provided by the voltage control terminal;

[0010] The output control circuit is electrically connected to the read control terminal and the read line respectively, and is used for controlling the output of the current signal to the read line under the control of the read control signal provided by the read control terminal.

[0011] Optionally, the compensation terminal is the first node; or, the compensation terminal is a compensation voltage terminal;

[0012] The compensation voltage terminal is used to provide a compensation voltage.

[0013] Optionally, the pixel circuit described in the embodiment of the present invention further includes a second voltage control circuit;

[0014] The second voltage control circuit is electrically connected to the voltage supply control terminal, the control voltage terminal and the second node respectively, and is used to write the control voltage provided by the control voltage terminal into the second node under the control of the voltage supply control signal provided by the voltage supply control terminal, so as to correspondingly change the potential of the control terminal of the driving circuit.

[0015] Optionally, the pixel circuit described in the embodiment of the present invention further includes a reset circuit;

[0016] The reset circuit is electrically connected to the reset control terminal, the reset voltage terminal and the first node respectively, and is used to write the reset voltage signal provided by the reset voltage terminal into the first node under the control of the reset control signal provided by the reset control terminal.

[0017] Optionally, the compensation circuit includes a compensation transistor; the first voltage control circuit includes a first voltage control transistor;

[0018] The control electrode of the compensation transistor is electrically connected to the compensation control terminal, the first electrode of the compensation transistor is electrically connected to the compensation terminal, and the second electrode of the compensation transistor is electrically connected to the first terminal of the driving circuit;

[0019] The control electrode of the first voltage-controlled transistor is electrically connected to the voltage control terminal, the first electrode of the first voltage-controlled transistor is electrically connected to the second terminal of the driving circuit, and the second electrode of the first voltage-controlled transistor is electrically connected to the second node.

[0020] Optionally, the second voltage control circuit includes a second voltage control transistor;

[0021] The control electrode of the second voltage-controlled transistor is electrically connected to the voltage supply control terminal, the first electrode of the second voltage-controlled transistor is electrically connected to the control voltage terminal, and the second electrode of the second voltage-controlled transistor is electrically connected to the second node.

[0022] Optionally, the reset circuit includes a reset transistor;

[0023] The control electrode of the reset transistor is electrically connected to the reset control terminal, the first electrode of the reset transistor is electrically connected to the reset voltage terminal, and the second electrode of the reset transistor is electrically connected to the first node.

[0024] Optionally, the compensation terminal is a compensation voltage terminal; the pixel circuit further includes an on-off control circuit, the second terminal of the driving circuit is electrically connected to the first voltage terminal through the on-off control circuit; the control terminal of the on-off control circuit is electrically connected to the reading control terminal;

[0025] The on-off control circuit is used to control the connection or disconnection between the second end of the driving circuit and the first voltage end under the control of the read control signal provided by the read control end.

[0026] Optionally, the driving circuit includes a driving transistor; the control pole of the driving transistor is the control end of the driving circuit, the first pole of the driving transistor is the first end of the driving circuit, and the second pole of the driving transistor is the second end of the driving circuit;

[0027] The energy storage circuit includes a storage capacitor, a first end of the storage capacitor is electrically connected to the first node, and a second end of the storage capacitor is electrically connected to the second node;

[0028] The output control circuit includes an output control transistor; the control electrode of the output control transistor is electrically connected to the read control terminal, the first electrode of the output control transistor is electrically connected to the first electrode of the drive transistor, and the second electrode of the output control transistor is electrically connected to the read line.

[0029] The present invention further provides a pixel driving method, which is applied to the above-mentioned pixel circuit, and the pixel driving method comprises:

[0030] The photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output terminal;

[0031] The driving circuit converts the potential of its control terminal into a corresponding current signal;

[0032] The compensation circuit controls the connection between the compensation terminal and the first terminal of the driving circuit under the control of the compensation control signal;

[0033] The first voltage control circuit controls the second node to be connected to the second end of the driving circuit under the control of the voltage control signal;

[0034] The output control circuit controls the current signal to be output to the read line under the control of the read control signal.

[0035] Optionally, the compensation end is a first node; the pixel driving cycle includes a compensation phase, a detection phase and a reading phase which are arranged in sequence, and the pixel driving method includes:

[0036] In the compensation stage, the compensation circuit controls the first node to be connected to the first end of the driving circuit under the control of the compensation control signal, and the first voltage control circuit controls the first voltage signal to be written into the second node under the control of the voltage control signal to change the potential of the first node;

[0037] In the detection phase, the first voltage control circuit controls the first voltage signal to be written into the second node under the control of the voltage control signal, and the photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output terminal to change the potential of the first node;

[0038] In the reading phase, the driving circuit converts the potential of its control terminal into a corresponding current signal, and the output control circuit controls the current signal to be output to the reading line under the control of the reading control signal.

[0039] Optionally, the pixel circuit further includes a second voltage control circuit, and the pixel driving method further includes:

[0040] In the reading stage, the second voltage control circuit writes the control voltage provided by the control voltage terminal into the second node under the control of the voltage supply control signal provided by the voltage supply control terminal, so as to correspondingly change the potential of the control terminal of the driving circuit, thereby making the driving transistor in the driving circuit operate in the saturation region.

[0041] Optionally, the pixel circuit further includes a reset circuit, and the pixel driving cycle further includes a reset phase arranged before the compensation phase; and the pixel driving method further includes:

[0042] In the reset stage, the first voltage control circuit controls the writing of the first voltage signal into the second node under the control of the voltage control signal, and the reset circuit writes the reset voltage signal into the first node under the control of the reset control signal to reset the potential of the first node and the potential of the second node.

[0043] Optionally, the compensation terminal is a compensation voltage terminal; the pixel circuit further includes a reset circuit and an on-off control circuit, the reset circuit is used to write a reset voltage signal into the first node under the control of a reset control signal provided by the reset control terminal; the on-off control circuit is used to control the connection or disconnection between the second terminal of the driving circuit and the first voltage terminal under the control of a read control signal provided by the read control terminal; the pixel driving cycle includes a compensation stage, a detection stage and a read stage which are arranged in sequence, and the pixel driving method includes:

[0044] In the compensation phase, the reset circuit writes a reset voltage signal to the first node under the control of the reset control signal, so that when the compensation phase starts, the driving transistor included in the driving circuit can be turned on; the on-off control circuit controls the second end of the driving circuit to be disconnected from the first voltage end under the control of the read control signal; the compensation circuit controls the compensation voltage end to provide the compensation voltage to the first end of the driving circuit under the control of the compensation control signal, so as to change the potential of the second node accordingly;

[0045] In the detection phase, the first voltage control circuit controls the second node to be connected to the second end of the driving circuit under the control of the voltage control signal, and the photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output end to change the potential of the first node;

[0046] During the reading stage, the driving circuit converts the potential of its control terminal into a corresponding current signal, and the on-off control circuit controls the connection between the second terminal of the driving circuit and the first voltage terminal under the control of the reading control signal; the output control circuit controls the output of the current signal to the reading line under the control of the reading control signal.

[0047] Optionally, the pixel circuit further includes a second voltage control circuit, and the pixel driving method further includes:

[0048] In the detection phase and the reading phase, the second voltage control circuit writes the control voltage provided by the control voltage terminal into the second node under the control of the voltage supply control signal.

[0049] The present invention also provides a display device, comprising the above pixel circuit.

[0050] The pixel circuit, pixel driving method and display device described in the embodiments of the present invention can make the current signal provided to the read line independent of the threshold voltage of the driving transistor of the driving circuit, thereby eliminating the current error caused by the non-uniformity of the threshold voltage of the driving transistor. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1is a structural diagram of a pixel circuit according to an embodiment of the present invention;

[0052] Figure 2 is a structural diagram of a pixel circuit according to an embodiment of the present invention;

[0053] Figure 3 is a structural diagram of a pixel circuit according to an embodiment of the present invention;

[0054] Figure 4 is a circuit diagram of a pixel circuit according to an embodiment of the present invention;

[0055] Figure 5 The present invention is Figure 4 The working timing diagram of the embodiment of the pixel circuit shown;

[0056] Figure 6 is a structural diagram of a pixel circuit according to an embodiment of the present invention;

[0057] Figure 7 is a structural diagram of a pixel circuit according to an embodiment of the present invention;

[0058] Figure 8 is a structural diagram of a pixel circuit according to an embodiment of the present invention;

[0059] Fig. 9 is a circuit diagram of a pixel circuit according to an embodiment of the present invention;

[0060] Fig.10 The present invention is Fig. 9 FIG. 1 is an operational timing diagram of an embodiment of a pixel circuit shown in FIG. DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] The transistors used in all embodiments of the present invention may be triodes, thin film transistors, field effect transistors or other devices with the same characteristics. In the embodiments of the present invention, in order to distinguish the two electrodes of the transistor except the control electrode, one of the electrodes is called the first electrode and the other is called the second electrode.

[0063] In actual operation, when the transistor is a triode, the control electrode may be a base, the first electrode may be a collector, and the second electrode may be an emitter; or, the control electrode may be a base, the first electrode may be an emitter, and the second electrode may be a collector.

[0064] In actual operation, when the transistor is a thin film transistor or a field effect transistor, the control electrode can be a gate, the first electrode can be a drain, and the second electrode can be a source; or, the control electrode can be a gate, the first electrode can be a source, and the second electrode can be a drain.

[0065] The pixel circuit described in the embodiment of the present invention includes a photoelectric sensor, a driving circuit, a storage circuit, a compensation circuit, a first voltage control circuit and an output control circuit, wherein:

[0066] The photoelectric sensor is used to convert the received light signal into a corresponding photovoltage signal, and output the photovoltage signal through the photovoltage signal output terminal;

[0067] The control end of the driving circuit is electrically connected to the photovoltage signal output end, the first end of the driving circuit is electrically connected to the output control circuit, the second end of the driving circuit is electrically connected to the first voltage end, and the driving circuit is used to convert the potential of its control end into a corresponding current signal and output the current signal through the first end;

[0068] The first end of the energy storage circuit is electrically connected to the first node, and the second end of the energy storage circuit is electrically connected to the second node; the first node is electrically connected to the control end of the drive circuit; the energy storage circuit is used to store electrical energy;

[0069] The compensation circuit is electrically connected to the compensation control terminal, the first terminal of the drive circuit and the compensation terminal respectively, and is used to control the connection between the compensation terminal and the first terminal of the drive circuit under the control of the compensation control signal provided by the compensation control terminal;

[0070] The first voltage control circuit is electrically connected to the voltage control terminal, the second node and the second terminal of the driving circuit respectively, and is used to control the second node to be connected to the second terminal of the driving circuit under the control of the voltage control signal provided by the voltage control terminal;

[0071] The output control circuit is electrically connected to the read control terminal and the read line respectively, and is used for controlling the output of the current signal to the read line under the control of the read control signal provided by the read control terminal.

[0072] The pixel circuit described in the embodiment of the present invention can make the current signal provided to the read line independent of the threshold voltage of the driving transistor of the driving circuit, thereby eliminating the current error caused by the non-uniformity of the threshold voltage of the driving transistor.

[0073] Optionally, the compensation terminal may be a first node; or, the compensation terminal may be a compensation voltage terminal;

[0074] The compensation voltage terminal is used to provide a compensation voltage.

[0075] like Figure 1 As shown, the pixel circuit described in the embodiment of the present invention includes a photoelectric sensor P0, a driving circuit 11, a storage circuit 12, a compensation circuit 13, a first voltage control circuit 14 and an output control circuit 15, wherein:

[0076] The photoelectric sensor P0 is used to convert the received light signal into a corresponding photovoltage signal, and output the photovoltage signal through the photovoltage signal output terminal;

[0077] The control end of the driving circuit 11 is electrically connected to the photovoltage signal output end, the first end of the driving circuit 11 is electrically connected to the output control circuit 15, the second end of the driving circuit 11 is electrically connected to the first voltage end V1, the driving circuit 11 is used to convert the potential of its control end into a corresponding current signal, and output the current signal through the first end; the first voltage end V1 is used to provide a first voltage signal, and the voltage value of the first voltage signal is V01;

[0078] The first end of the energy storage circuit 12 is electrically connected to the first node N1, and the second end of the energy storage circuit 12 is electrically connected to the second node N2; the first node N1 is electrically connected to the control end of the drive circuit 11; the energy storage circuit 12 is used to store electric energy; the first node N1 is electrically connected to the control end of the drive circuit 11;

[0079] The compensation circuit 13 is electrically connected to the compensation control terminal G2, the first node N1 and the first terminal of the driving circuit 11 respectively, and is used to control the first node N1 to be connected to the first terminal of the driving circuit 11 under the control of the compensation control signal provided by the compensation control terminal G2;

[0080] The first voltage control circuit 14 is electrically connected to the voltage control terminal G3, the second node N2 and the first voltage terminal V1 respectively, and is used to control the first voltage signal provided by the first voltage terminal V1 to be written into the second node N2 under the control of the voltage control signal provided by the voltage control terminal G3;

[0081] The output control circuit 15 is electrically connected to the read control terminal G4 and the read line R0 respectively, and is used to control the current signal to be output to the read line R0 under the control of the read control signal provided by the read control terminal R0.

[0082] exist Figure 1 In the illustrated embodiment, the compensation terminal is a first node.

[0083] In the embodiment of the present invention, the first voltage terminal V1 may be a low voltage terminal, but is not limited thereto.

[0084] The present invention Figure 1 The pixel circuit shown may be an APS (Active Pixel Sensor) pixel circuit, but is not limited thereto.

[0085] Optionally, the photoelectric sensor may be a photodiode or an MSM (metal-semiconductor-metal) photoelectric detector, but is not limited thereto.

[0086] The pixel circuit described in the embodiment of the present invention can make the current signal provided to the read line R0 independent of the threshold voltage of the driving transistor of the driving circuit 11, thereby eliminating the current error caused by the non-uniformity of the threshold voltage of the driving transistor.

[0087] The present invention Figure 1 When the pixel circuit shown is in operation, a pixel driving cycle may include a compensation phase, a detection phase, and a reading phase that are sequentially arranged;

[0088] At the beginning of the compensation phase, the driving transistor included in the driving circuit 11 is turned on;

[0089] In the compensation stage, the compensation circuit 13 controls the connection between the first node N1 and the first end of the driving circuit 11 under the control of the compensation control signal, and the first voltage control circuit 14 controls the writing of the first voltage signal into the second node N2 under the control of the voltage control signal; the energy storage circuit 12 discharges to the first voltage end V1 through the compensation circuit 13 and the driving circuit 11 to reduce the potential of the first node N1 until the driving transistor included in the driving circuit 11 is turned off, at which time the potential of N1 is V01+Vth, thereby compensating for the threshold voltage of the driving transistor; wherein Vth is the threshold voltage of the driving transistor;

[0090] In the detection phase, illumination is started, and the first voltage control circuit 14 controls the first voltage signal to be written into the second node N2 under the control of the voltage control signal, and the photoelectric sensor P0 converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output terminal to change the potential of the first node N1, so that the potential of N1 becomes V01+Vth+ΔV;

[0091] In the reading phase, the driving circuit 11 converts the potential of its control terminal into a corresponding current signal, and the output control circuit 15 controls the current signal to be output to the reading line R0 under the control of the reading control signal.

[0092] In a specific implementation, the current signal outputted by the read line R0 can be used to obtain parameters such as the light intensity corresponding to the light signal.

[0093] Optionally, the pixel circuit described in the embodiment of the present invention may further include a second voltage control circuit;

[0094] The second voltage control circuit is electrically connected to the voltage supply control terminal, the control voltage terminal and the second node respectively, and is used to write the control voltage provided by the control voltage terminal into the second node under the control of the voltage supply control signal provided by the voltage supply control terminal, so as to correspondingly change the potential of the control terminal of the driving circuit.

[0095] In at least one embodiment of the present invention, when the compensation terminal is the first node, the power supply control terminal and the read control terminal may be the same terminal.

[0096] like Figure 2 As shown, in Figure 1 Based on the embodiment of the pixel circuit shown, the pixel circuit described in the embodiment of the present invention may further include a second voltage control circuit 20;

[0097] The second voltage control circuit 20 is electrically connected to the read control terminal G4, the control voltage terminal V2 and the second node N2, respectively, and is used to write the control voltage provided by the control voltage terminal V2 into the second node under the control of the read control signal provided by the read control terminal G4, so as to correspondingly change the potential of the control terminal of the driving circuit 11.

[0098] The present invention Figure 2 When the embodiment of the pixel circuit is working, in the reading stage, the second voltage control circuit 20 is electrically connected to the reading control terminal G4, the control voltage terminal V2 and the second node N2, respectively, and is used to write the control voltage provided by the control voltage terminal V2 into the second node under the control of the reading control signal provided by the reading control terminal G4, so as to correspondingly change the potential of the control terminal of the driving circuit 11, so that the transistor in the driving circuit 11 can operate in the saturation region.

[0099] In the embodiment of the present invention, Figure 3 As shown, in Figure 2 Based on the embodiment of the pixel circuit shown, the pixel circuit may further include a reset circuit 30;

[0100] The reset circuit 30 is electrically connected to the reset control terminal G1, the reset voltage terminal Vr and the first node N1 respectively, and is used to write the reset voltage signal provided by the reset voltage terminal Vr into the first node N1 under the control of the reset control signal provided by the reset control terminal G1.

[0101] The present invention Figure 3When the embodiment of the pixel circuit shown is in operation, the pixel driving cycle further includes a reset phase arranged before the compensation phase;

[0102] In the reset stage, the first voltage control circuit 14 controls the writing of the first voltage signal into the second node N2 under the control of the voltage control signal, and the reset circuit 30 writes the reset voltage signal into the first node N1 under the control of the reset control signal to reset the potential of the first node N1 and the potential of the second node N2, so that the driving transistor included in the driving circuit 11 can be turned on.

[0103] Optionally, the compensation circuit includes a compensation transistor; the first voltage control circuit includes a first voltage control transistor;

[0104] The control electrode of the compensation transistor is electrically connected to the compensation control terminal, the first electrode of the compensation transistor is electrically connected to the compensation terminal, and the second electrode of the compensation transistor is electrically connected to the first terminal of the driving circuit;

[0105] The control electrode of the first voltage-controlled transistor is electrically connected to the voltage control terminal, the first electrode of the first voltage-controlled transistor is electrically connected to the second terminal of the driving circuit, and the second electrode of the first voltage-controlled transistor is electrically connected to the second node.

[0106] Optionally, the second voltage control circuit includes a second voltage control transistor;

[0107] The control electrode of the second voltage-controlled transistor is electrically connected to the voltage supply control terminal, the first electrode of the second voltage-controlled transistor is electrically connected to the control voltage terminal, and the second electrode of the second voltage-controlled transistor is electrically connected to the second node.

[0108] In a specific implementation, the reset circuit may include a reset transistor;

[0109] The control electrode of the reset transistor is electrically connected to the reset control terminal, the first electrode of the reset transistor is electrically connected to the reset voltage terminal, and the second electrode of the reset transistor is electrically connected to the first node.

[0110] Optionally, the driving circuit includes a driving transistor; the control pole of the driving transistor is the control end of the driving circuit, the first pole of the driving transistor is the first end of the driving circuit, and the second pole of the driving transistor is the second end of the driving circuit;

[0111] The energy storage circuit includes a storage capacitor, a first end of the storage capacitor is electrically connected to the first node, and a second end of the storage capacitor is electrically connected to the second node;

[0112] The output control circuit includes an output control transistor; the control electrode of the output control transistor is electrically connected to the read control terminal, the first electrode of the output control transistor is electrically connected to the first electrode of the drive transistor, and the second electrode of the output control transistor is electrically connected to the read line.

[0113] like Figure 4 As shown, in Figure 3 Based on the embodiment of the pixel circuit shown,

[0114] The compensation circuit 13 includes a compensation transistor T1; the first voltage control circuit 14 includes a first voltage control transistor T6; the second voltage control circuit 20 includes a second voltage control transistor T5; the reset circuit 30 includes a reset transistor T4; the drive circuit 11 includes a drive transistor T2; the energy storage circuit 12 includes a storage capacitor C1; the output control circuit 15 includes an output control transistor T3;

[0115] The gate of the compensation transistor T1 is electrically connected to the compensation control terminal G2, the drain of the compensation transistor T1 is electrically connected to the gate of the driving transistor T2, and the source of the compensation transistor T1 is electrically connected to the drain of the driving transistor T2;

[0116] The gate of the first voltage control transistor T6 is electrically connected to the voltage control terminal G3, the drain of the first voltage control transistor T6 is electrically connected to the low voltage terminal, and the source of the first voltage control transistor T6 is electrically connected to the second node N2; the low voltage terminal is used to provide a low voltage VSS;

[0117] The gate of the second voltage control transistor T5 is electrically connected to the read control terminal G4, the drain of the second voltage control transistor T5 is electrically connected to the control voltage terminal V2, and the source of the second voltage control transistor T5 is electrically connected to the second node N2;

[0118] The gate of the reset transistor T4 is electrically connected to the reset control terminal G1, the drain of the reset transistor T4 is electrically connected to the reset voltage terminal Vr, and the source of the reset transistor T4 is electrically connected to the first node N1;

[0119] The gate of the driving transistor T2 is the control terminal of the driving circuit 11, the drain of the driving transistor T2 is the first terminal of the driving circuit 11, and the source of the driving transistor T2 is the second terminal of the driving circuit 11;

[0120] The first end of the storage capacitor C1 is electrically connected to the first node N1, and the second end of the storage capacitor C2 is electrically connected to the second node N2;

[0121] The gate of the output control transistor T3 is electrically connected to the read control terminal G4 , the drain of the output control transistor T3 is electrically connected to the drain of the drive transistor T2 , and the source of the output control transistor T3 is electrically connected to the read line R0 .

[0122] exist Figure 4 In the embodiment of the pixel circuit shown, all transistors are n-type thin film transistors, but the present invention is not limited thereto.

[0123] like Figure 5 As shown, Figure 4 When the embodiment of the pixel circuit shown is in operation, the pixel driving cycle may include a reset phase P1, a compensation phase P2, a detection phase P3 and a reading phase P4 which are arranged in sequence;

[0124] In the reset phase P1, G1 and G3 provide a high voltage, T4 and T6 are both turned on, and the potential of N1 and the potential of N2 are reset, so that when the compensation phase P2 starts, T2 can be turned on and the previous charge remaining in N1 can be eliminated; G2 and G4 both provide a low voltage, and T1, T3 and T5 are all turned off;

[0125] In the compensation phase P2, G1 provides a low voltage, G2 and G3 both provide a low voltage, G4 provides a low voltage, T4 is turned off, T1 and T6 are both turned on, T3 and T5 are both turned off. At the beginning of the compensation phase P2, T2 is turned on, and C1 discharges to the low voltage end through the turned-on T1 and T2 to reduce the potential of N1 until the potential of N1 is VSS+Vth, and T2 is turned off; wherein Vth is the threshold voltage of T2;

[0126] In the detection phase P3, G1, G2 and G4 all provide low voltages, G3 provides high voltages, T4, T1, T3 and T5 are all turned off, and T6 is turned on, so that the potential of N2 is the same as in the previous phase, and illumination begins. The photosensor P0 converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output terminal to change the potential of the first node N1, so that the potential of N1 changes by ΔV, and the potential of N1 becomes VSS+Vth+ΔV;

[0127] In the reading phase P4, G1, G2 and G3 all provide low voltages, V2 provides a control voltage, the voltage value of the control voltage is V02, G4 provides a high voltage, T1, T4 and T6 are all closed, T3 and T5 are all open, the control voltage provided by V2 is written to N2, the potential of N1 becomes V02+Vth+ΔV, the potential of N2 becomes V02, T2 is turned on to output a current signal to the reading line R0 through T3, and the current value I of the current signal is equal to K(V02-VSS+ΔV) 2 ; The current value of the current signal has nothing to do with Vth.

[0128] In the reading phase P4 , a control voltage is provided so that T2 operates in a saturation region. Since ΔV can be a positive value or a negative value, the difference between V02 and VSS needs to be greater than |ΔV|, but is not limited thereto.

[0129] Since in the reading stage P4, the gate-source voltage Vgs of T2 is equal to V02+Vth+ΔV-VSS, Vgs needs to be greater than Vth, that is, V02-VSS needs to be greater than -ΔV. Since ΔV can be positive or negative, the difference between V02 and VSS needs to be greater than |ΔV|.

[0130] like Figure 6 As shown, the pixel circuit described in the embodiment of the present invention includes a photoelectric sensor P0, a driving circuit 11, a storage circuit 12, a compensation circuit 13, a first voltage control circuit 14 and an output control circuit 15, wherein:

[0131] The photoelectric sensor P0 is used to convert the received light signal into a corresponding photovoltage signal, and output the photovoltage signal through the photovoltage signal output terminal;

[0132] The control end of the driving circuit 11 is electrically connected to the photovoltage signal output end, the first end of the driving circuit 11 is electrically connected to the output control circuit 15, the second end of the driving circuit 11 is electrically connected to the first voltage end V1, the driving circuit 11 is used to convert the potential of its control end into a corresponding current signal, and output the current signal through the first end; the first voltage end V1 is used to provide a first voltage signal, and the voltage value of the first voltage signal is V01;

[0133] The first end of the energy storage circuit 12 is electrically connected to the first node N1, and the second end of the energy storage circuit 12 is electrically connected to the second node N2; the first node N1 is electrically connected to the control end of the drive circuit 11; the energy storage circuit 12 is used to store electric energy; the first node N1 is electrically connected to the control end of the drive circuit 11;

[0134] The compensation circuit 13 is electrically connected to the compensation control terminal G2, the first node N1 and the first terminal of the driving circuit 11 respectively, and is used to control the connection between the compensation voltage terminal and the first terminal of the driving circuit 11 under the control of the compensation control signal provided by the compensation control terminal G2; the compensation voltage terminal is used to provide a compensation voltage V3;

[0135] The first voltage control circuit 14 is electrically connected to the voltage control terminal G3, the second node N2 and the second end of the driving circuit 11 respectively, and is used to control the second node N2 to be connected to the second end of the driving circuit 11 under the control of the voltage control signal provided by the voltage control terminal G3;

[0136] The output control circuit 15 is electrically connected to the read control terminal G4 and the read line R0 respectively, and is used to control the current signal to be output to the read line R0 under the control of the read control signal provided by the read control terminal R0.

[0137] In the present invention, Figure 6 In the embodiment of the pixel circuit shown, the compensation terminal is a compensation voltage terminal, and the compensation voltage terminal is used to provide a compensation voltage V3.

[0138] Optionally, the compensation terminal is a compensation voltage terminal; the pixel circuit further includes an on-off control circuit, the second terminal of the driving circuit is electrically connected to the first voltage terminal through the on-off control circuit; the control terminal of the on-off control circuit is electrically connected to the reading control terminal;

[0139] The on-off control circuit is used to control the connection or disconnection between the second end of the driving circuit and the first voltage end under the control of the read control signal provided by the read control end.

[0140] like Figure 7 As shown, in Figure 6 Based on the embodiment of the pixel circuit shown, the pixel circuit described in the embodiment of the present invention may further include a reset circuit 30 and an on-off control circuit 70;

[0141] The reset circuit 30 is electrically connected to the reset control terminal G1, the reset voltage terminal Vr and the first node N1 respectively, and is used to write the reset voltage signal provided by the reset voltage terminal Vr into the first node N1 under the control of the reset control signal provided by the reset control terminal G1;

[0142] The first end of the on-off control circuit 70 is electrically connected to the second end of the driving circuit 11, and the second end of the on-off control circuit 70 is electrically connected to the first voltage end V1;

[0143] The control end of the on-off control circuit 70 is electrically connected to the read control end G4, and is used to control the connection or disconnection between the second end of the driving circuit 11 and the first voltage end V1 under the control of the read control signal.

[0144] exist Figure 7 In the illustrated embodiment, when the compensation terminal is a compensation voltage terminal, the reset control terminal may be the same terminal as the compensation control terminal, and the voltage control terminal may be the same terminal as the compensation control terminal, but the present invention is not limited thereto.

[0145] In a specific implementation, the on-off control circuit may include an on-off control transistor; the first electrode of the on-off control transistor is electrically connected to the second end of the driving circuit 11, the second electrode of the on-off control transistor is electrically connected to the first voltage end, and the control electrode of the on-off control transistor is electrically connected to the reading control end; but not limited to this.

[0146] The present invention Figure 7 When the embodiment of the pixel circuit shown is in operation, the pixel driving cycle includes a compensation phase, a detection phase and a reading phase which are arranged in sequence, and the pixel driving method includes:

[0147] In the compensation phase, the reset circuit writes a reset voltage signal to the first node under the control of the reset control signal, so that when the compensation phase starts, the driving transistor included in the driving circuit can be turned on; the on-off control circuit controls the second end of the driving circuit to be disconnected from the first voltage end under the control of the read control signal; the compensation circuit controls the compensation voltage end to provide the compensation voltage to the first end of the driving circuit under the control of the compensation control signal, so as to change the potential of the second node accordingly;

[0148] In the detection phase, the first voltage control circuit controls the second node to be connected to the second end of the driving circuit under the control of the voltage control signal, and the photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output end to change the potential of the first node;

[0149] During the reading stage, the driving circuit converts the potential of its control terminal into a corresponding current signal, and the on-off control circuit controls the connection between the second terminal of the driving circuit and the first voltage terminal under the control of the reading control signal; the output control circuit controls the output of the current signal to the reading line under the control of the reading control signal.

[0150] The present invention Figure 7 When the embodiment of the pixel circuit shown is in operation, in the detection phase and the reading phase, the second voltage control circuit 20 can write the control voltage provided by the control voltage terminal V2 into the second node N2 under the control of the power supply control signal.

[0151] like Figure 8 As shown, in Figure 7 Based on the embodiment of the pixel circuit shown, the pixel circuit described in the embodiment of the present invention may further include a second voltage control circuit 20;

[0152] The second voltage control circuit is electrically connected to the voltage supply control terminal G0, the control voltage terminal V2 and the second node N2, respectively, and is used to write the control voltage provided by the control voltage terminal V2 into the second node under the control of the voltage supply control signal provided by the voltage supply control terminal G0, so as to correspondingly change the potential of the control terminal of the driving circuit 11.

[0153] The present invention Figure 8 When the embodiment of the pixel circuit is working, in the reading stage, the second voltage control circuit 20, under the control of the power supply control signal, writes the control voltage provided by the control voltage terminal V2 into the second node to correspondingly change the potential of the control terminal of the driving circuit 11, so that the transistor in the driving circuit 11 can operate in the saturation region.

[0154] The present invention Figure 8 The embodiment of the pixel circuit shown may further include a reset phase before the compensation phase when in operation;

[0155] In the reset stage, the second voltage control circuit 20, under the control of the power supply control signal, writes the control voltage provided by the control voltage terminal V2 into the second node N2, and the reset circuit 30, under the control of the reset control signal, writes the reset voltage signal into the first node N1 to reset the potential of N1 and the potential of N2.

[0156] like Fig. 9 As shown, in Figure 8 Based on the embodiment of the pixel circuit shown, the compensation circuit 13 includes a compensation transistor T1; the first voltage control circuit 14 includes a first voltage control transistor T6; the second voltage control circuit 20 includes a second voltage control transistor T5; the reset circuit 30 includes a reset transistor T4; the drive circuit 11 includes a drive transistor T2; the energy storage circuit 12 includes a storage capacitor C1; the output control circuit 15 includes an output control transistor T3; the on-off control circuit 40 includes an on-off control transistor T0;

[0157] The gate of the compensation transistor T1 is electrically connected to the compensation control terminal G2, the drain of the compensation transistor T1 is electrically connected to the compensation voltage terminal V3, and the source of the compensation transistor T1 is electrically connected to the drain of the driving transistor T2;

[0158] The gate of the first voltage control transistor T6 is electrically connected to the compensation control terminal G2, the drain of the first voltage control transistor T6 is electrically connected to the source of T2, and the source of the first voltage control transistor T6 is electrically connected to the second node N2;

[0159] The gate of the second voltage control transistor T5 is electrically connected to the power supply control terminal G0, the drain of the second voltage control transistor T5 is electrically connected to the control voltage terminal V2, and the source of the second voltage control transistor T5 is electrically connected to the second node N2;

[0160] The gate of the reset transistor T4 is electrically connected to the compensation control terminal G2, the drain of the reset transistor T4 is electrically connected to the reset voltage terminal Vr, and the source of the reset transistor T4 is electrically connected to the first node N1;

[0161] The gate of the driving transistor T2 is the control terminal of the driving circuit 11, the drain of the driving transistor T2 is the first terminal of the driving circuit 11, and the source of the driving transistor T2 is the second terminal of the driving circuit 11;

[0162] The first end of the storage capacitor C1 is electrically connected to the first node N1, and the second end of the storage capacitor C2 is electrically connected to the second node N2;

[0163] The gate of the output control transistor T3 is electrically connected to the read control terminal G4, the drain of the output control transistor T3 is electrically connected to the drain of the drive transistor T2, and the source of the output control transistor T3 is electrically connected to the read line R0;

[0164] The gate of the on-off control transistor T0 is electrically connected to the read control terminal G4, the drain of the on-off control transistor T0 is electrically connected to the source of T2, and the source of the on-off control transistor T0 is electrically connected to a low voltage terminal; the low voltage terminal is used to provide a low voltage VSS.

[0165] exist Fig. 9 In the embodiment of the pixel circuit shown, all transistors are n-type thin film transistors, but the present invention is not limited thereto.

[0166] exist Fig. 9 In the illustrated embodiment, the reset control terminal and the compensation control terminal are the same terminal, and the voltage control terminal and the compensation control terminal are the same terminal.

[0167] like Fig.10 As shown, the present invention is Fig. 9 When the embodiment of the pixel circuit shown is in operation, a display cycle may include a reset phase P1, a compensation phase P2, a detection phase P3 and a reading phase P4 which are arranged in sequence;

[0168] In the reset phase P1, G0 and G2 both provide high voltages, G4 provides low voltages, T1, T2, T4 and T3 are all turned on, and N1 and N2 are reset, so that when the compensation phase P2 begins, T2 can be turned on and the charge remaining in N1 can be eliminated;

[0169] In the compensation phase P2, G2 provides a high voltage, G0 and G4 both provide a low voltage, T4, T6 and T1 are all turned on, T3, T0 and T5 are all turned off, Vr provides a reset voltage signal, the voltage value of the reset voltage signal is V0, N1 is connected to Vr, the potential of N1 is V0, the drain of T6 is electrically connected to the compensation voltage terminal, at the beginning of the compensation phase P2, T6 is turned on, and the compensation voltage V3 provided by the compensation voltage terminal charges C1 to change the potential of N2 until the potential of N2 becomes V0-Vth, and T2 is turned off, where Vth is the threshold voltage of T2;

[0170] In the detection phase P3, G0 provides a high voltage, G2 and G4 both provide a low voltage, the control voltage terminal V2 provides a control voltage, the voltage value of the control voltage is V02, T5 is turned on, T4, T3, T1, T6 and T0 are all turned off, the potential of N2 becomes V02, the potential of N1 becomes V02+Vth, the photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output terminal, so that the potential of N1 changes by ΔV, and the potential of N1 becomes V02+Vth+ΔV;

[0171] In the reading phase P4, G2 provides a low voltage, G0 and G4 both provide a high voltage, the control voltage terminal V2 provides a control voltage, the voltage value of the control voltage is V02, T5, T0 and T3 are all turned on, T2 is turned on to output a current signal to the reading line R0 through T3, and the current value I of the current signal is equal to K(V02-VSS+ΔV) 2 ; The current value of the current signal has nothing to do with Vth.

[0172] In the reading phase P4 , V2 provides a control voltage to make T2 work in the saturation region.

[0173] Since in the reading stage P4, the gate-source voltage Vgs of T2 is equal to V02+Vth+ΔV-VSS, Vgs needs to be greater than Vth, that is, V02-VSS needs to be greater than -ΔV. Since ΔV can be positive or negative, the difference between V02 and VSS needs to be greater than |ΔV|.

[0174] The pixel driving method described in the embodiment of the present invention is applied to the above-mentioned pixel circuit, and the pixel driving method may include:

[0175] The photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output terminal;

[0176] The driving circuit converts the potential of its control terminal into a corresponding current signal;

[0177] The compensation circuit controls the connection between the compensation terminal and the first terminal of the driving circuit under the control of the compensation control signal;

[0178] The first voltage control circuit controls the second node to be connected to the second end of the driving circuit under the control of the voltage control signal;

[0179] The output control circuit controls the current signal to be output to the read line under the control of the read control signal.

[0180] The pixel driving method described in the embodiment of the present invention can make the current signal provided to the read line independent of the threshold voltage of the driving transistor of the driving circuit, and can eliminate the current error caused by the non-uniformity of the threshold voltage of the driving transistor.

[0181] Optionally, when the compensation end is a first node, the pixel driving period includes a compensation phase, a detection phase and a reading phase which are arranged in sequence, and the pixel driving method includes:

[0182] In the compensation stage, the compensation circuit controls the first node to be connected to the first end of the driving circuit under the control of the compensation control signal, and the first voltage control circuit controls the first voltage signal to be written into the second node under the control of the voltage control signal to change the potential of the first node;

[0183] In the detection phase, the first voltage control circuit controls the first voltage signal to be written into the second node under the control of the voltage control signal, and the photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output terminal to change the potential of the first node;

[0184] In the reading phase, the driving circuit converts the potential of its control terminal into a corresponding current signal, and the output control circuit controls the current signal to be output to the reading line under the control of the reading control signal.

[0185] The pixel driving method described in the embodiment of the present invention can make the current signal provided to the read line independent of the threshold voltage of the driving transistor of the driving circuit, and can eliminate the current error caused by the non-uniformity of the threshold voltage of the driving transistor.

[0186] In a specific implementation, the pixel circuit may further include a second voltage control circuit, and the pixel driving method may further include:

[0187] In the reading phase, the second voltage control circuit, under the control of the power supply control signal, writes the control voltage provided by the control voltage terminal into the second node to correspondingly change the potential of the control terminal of the driving circuit, thereby making the driving transistor in the driving circuit operate in the saturation region.

[0188] Optionally, the pixel circuit further includes a reset circuit, and the pixel driving cycle further includes a reset phase arranged before the compensation phase; and the pixel driving method further includes:

[0189] In the reset phase, the first voltage control circuit controls the writing of the first voltage signal into the second node under the control of the voltage control signal, and the reset circuit writes the reset voltage signal into the first node under the control of the reset control signal to reset the potential of the first node and the potential of the second node, so that in the reset phase, the driving transistor included in the driving circuit can be turned on.

[0190] Optionally, when the compensation terminal is a compensation voltage terminal, the pixel circuit may further include a reset circuit and an on-off control circuit, wherein the reset circuit is used to write a reset voltage signal into the first node under the control of a reset control signal provided by the reset control terminal; the on-off control circuit is used to control the connection or disconnection between the second terminal of the driving circuit and the first voltage terminal under the control of a read control signal provided by the read control terminal; the pixel driving cycle includes a compensation phase, a detection phase and a read phase which are arranged in sequence, and the pixel driving method may include:

[0191] In the compensation phase, the reset circuit writes a reset voltage signal to the first node under the control of the reset control signal, so that when the compensation phase starts, the driving transistor included in the driving circuit can be turned on; the on-off control circuit controls the second end of the driving circuit to be disconnected from the first voltage end under the control of the read control signal; the compensation circuit controls the compensation voltage end to provide the compensation voltage to the first end of the driving circuit under the control of the compensation control signal, so as to change the potential of the second node accordingly;

[0192] In the detection phase, the first voltage control circuit controls the second node to be connected to the second end of the driving circuit under the control of the voltage control signal, and the photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output end to change the potential of the first node;

[0193] During the reading stage, the driving circuit converts the potential of its control terminal into a corresponding current signal, and the on-off control circuit controls the connection between the second terminal of the driving circuit and the first voltage terminal under the control of the reading control signal; the output control circuit controls the output of the current signal to the reading line under the control of the reading control signal.

[0194] Optionally, the pixel circuit further includes a second voltage control circuit, and the pixel driving method may further include:

[0195] In the detection phase and the reading phase, the second voltage control circuit writes the control voltage provided by the control voltage terminal into the second node under the control of the voltage supply control signal.

[0196] The display device described in the embodiment of the present invention includes the above-mentioned pixel circuit.

[0197] The display device provided in the embodiment of the present invention can be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, etc.

[0198] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A pixel circuit, characterized in that: It includes a photoelectric sensor, a driving circuit, a storage circuit, a compensation circuit, a first voltage control circuit and an output control circuit, wherein: The photoelectric sensor is used to convert the received light signal into a corresponding photovoltage signal, and output the photovoltage signal through the photovoltage signal output terminal; The control end of the driving circuit is electrically connected to the photovoltage signal output end, the first end of the driving circuit is electrically connected to the output control circuit, the second end of the driving circuit is electrically connected to the first voltage end, and the driving circuit is used to convert the potential of its control end into a corresponding current signal and output the current signal through the first end; The first end of the energy storage circuit is electrically connected to the first node, and the second end of the energy storage circuit is electrically connected to the second node; the first node is electrically connected to the control end of the drive circuit; the energy storage circuit is used to store electrical energy; The compensation circuit is electrically connected to the compensation control terminal, the first terminal of the drive circuit and the compensation terminal respectively, and is used to control the connection between the compensation terminal and the first terminal of the drive circuit under the control of the compensation control signal provided by the compensation control terminal; The first voltage control circuit is electrically connected to the voltage control terminal, the second node and the second terminal of the driving circuit respectively, and is used to control the connection between the second terminal of the driving circuit and the second node under the control of the voltage control signal provided by the voltage control terminal; The output control circuit is electrically connected to the read control terminal and the read line respectively, and is used for controlling the output of the current signal to the read line under the control of the read control signal provided by the read control terminal.

2. The pixel circuit according to claim 1, wherein: The compensation terminal is the first node; or, the compensation terminal is a compensation voltage terminal; The compensation voltage terminal is used to provide a compensation voltage.

3. The pixel circuit according to claim 1, wherein: Also comprising a second voltage control circuit; The second voltage control circuit is electrically connected to the voltage supply control terminal, the control voltage terminal and the second node respectively, and is used to write the control voltage provided by the control voltage terminal into the second node under the control of the voltage supply control signal provided by the voltage supply control terminal, so as to correspondingly change the potential of the control terminal of the driving circuit.

4. The pixel circuit according to any one of claims 1 to 3, characterized in that: Also includes a reset circuit; The reset circuit is electrically connected to the reset control terminal, the reset voltage terminal and the first node respectively, and is used to write the reset voltage signal provided by the reset voltage terminal into the first node under the control of the reset control signal provided by the reset control terminal.

5. The pixel circuit according to any one of claims 1 to 3, characterized in that: The compensation circuit includes a compensation transistor; the first voltage control circuit includes a first voltage control transistor; The control electrode of the compensation transistor is electrically connected to the compensation control terminal, the first electrode of the compensation transistor is electrically connected to the compensation terminal, and the second electrode of the compensation transistor is electrically connected to the first terminal of the driving circuit; The control electrode of the first voltage-controlled transistor is electrically connected to the voltage control terminal, the first electrode of the first voltage-controlled transistor is electrically connected to the second terminal of the driving circuit, and the second electrode of the first voltage-controlled transistor is electrically connected to the second node.

6. The pixel circuit according to claim 3, characterized in that: The second voltage control circuit includes a second voltage control transistor; The control electrode of the second voltage-controlled transistor is electrically connected to the voltage supply control terminal, the first electrode of the second voltage-controlled transistor is electrically connected to the control voltage terminal, and the second electrode of the second voltage-controlled transistor is electrically connected to the second node.

7. The pixel circuit according to claim 4, characterized in that: The reset circuit includes a reset transistor; The control electrode of the reset transistor is electrically connected to the reset control terminal, the first electrode of the reset transistor is electrically connected to the reset voltage terminal, and the second electrode of the reset transistor is electrically connected to the first node.

8. The pixel circuit according to claim 4, characterized in that: The compensation terminal is a compensation voltage terminal; the pixel circuit further includes an on-off control circuit, the second terminal of the driving circuit is electrically connected to the first voltage terminal through the on-off control circuit; the control terminal of the on-off control circuit is electrically connected to the reading control terminal; The on-off control circuit is used to control the connection or disconnection between the second end of the driving circuit and the first voltage end under the control of the read control signal provided by the read control end.

9. The pixel circuit according to claim 1, 2, 3 or 8, characterized in that: The driving circuit comprises a driving transistor; a control pole of the driving transistor is a control end of the driving circuit, a first pole of the driving transistor is a first end of the driving circuit, and a second pole of the driving transistor is a second end of the driving circuit; The energy storage circuit includes a storage capacitor, a first end of the storage capacitor is electrically connected to the first node, and a second end of the storage capacitor is electrically connected to the second node; The output control circuit includes an output control transistor; the control electrode of the output control transistor is electrically connected to the read control terminal, the first electrode of the output control transistor is electrically connected to the first electrode of the drive transistor, and the second electrode of the output control transistor is electrically connected to the read line.

10. A pixel driving method, applied to the pixel circuit according to any one of claims 1 to 9, characterized in that: The pixel driving method comprises: The photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output terminal; The driving circuit converts the potential of its control terminal into a corresponding current signal; The compensation circuit controls the connection between the compensation terminal and the first terminal of the driving circuit under the control of the compensation control signal; The first voltage control circuit controls the second node to be connected to the second end of the driving circuit under the control of the voltage control signal; The output control circuit controls the current signal to be output to the read line under the control of the read control signal.

11. The pixel driving method according to claim 10, wherein: The compensation end is a first node; the pixel driving cycle includes a compensation phase, a detection phase and a reading phase arranged in sequence, and the pixel driving method includes: In the compensation stage, the compensation circuit controls the first node to be connected to the first end of the driving circuit under the control of the compensation control signal, and the first voltage control circuit controls the first voltage signal to be written into the second node under the control of the voltage control signal to change the potential of the first node; In the detection phase, the first voltage control circuit controls the first voltage signal to be written into the second node under the control of the voltage control signal, and the photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output terminal to change the potential of the first node; In the reading phase, the driving circuit converts the potential of its control terminal into a corresponding current signal, and the output control circuit controls the current signal to be output to the reading line under the control of the reading control signal.

12. The pixel driving method according to claim 11, wherein: The pixel circuit further includes a second voltage control circuit, and the pixel driving method further includes: In the reading stage, the second voltage control circuit writes the control voltage provided by the control voltage terminal into the second node under the control of the voltage supply control signal provided by the voltage supply control terminal, so as to correspondingly change the potential of the control terminal of the driving circuit, thereby making the driving transistor in the driving circuit operate in the saturation region.

13. The pixel driving method according to claim 10, wherein: The compensation terminal is a compensation voltage terminal; the pixel circuit further includes a reset circuit and an on-off control circuit, the reset circuit is used to write a reset voltage signal into the first node under the control of a reset control signal provided by the reset control terminal; the on-off control circuit is used to control the connection or disconnection between the second terminal of the driving circuit and the first voltage terminal under the control of a read control signal provided by the read control terminal; the pixel driving cycle includes a compensation stage, a detection stage and a read stage which are arranged in sequence, and the pixel driving method includes: In the compensation phase, the reset circuit writes a reset voltage signal to the first node under the control of the reset control signal, so that when the compensation phase starts, the driving transistor included in the driving circuit can be turned on; the on-off control circuit controls the second end of the driving circuit to be disconnected from the first voltage end under the control of the read control signal; the compensation circuit controls the compensation voltage end to provide the compensation voltage to the first end of the driving circuit under the control of the compensation control signal, so as to change the potential of the second node accordingly; In the detection phase, the first voltage control circuit controls the second node to be connected to the second end of the driving circuit under the control of the voltage control signal, and the photoelectric sensor converts the received light signal into a corresponding photovoltage signal, and outputs the photovoltage signal through the photovoltage signal output end to change the potential of the first node; During the reading stage, the driving circuit converts the potential of its control terminal into a corresponding current signal, and the on-off control circuit controls the connection between the second terminal of the driving circuit and the first voltage terminal under the control of the reading control signal; the output control circuit controls the output of the current signal to the reading line under the control of the reading control signal.

14. The pixel driving method according to claim 13, wherein: The pixel circuit further includes a second voltage control circuit, and the pixel driving method further includes: In the detection phase and the reading phase, the second voltage control circuit writes the control voltage provided by the control voltage terminal into the second node under the control of the voltage supply control signal.

15. A display device, characterized in that: The method comprises a pixel circuit as claimed in any one of claims 1 to 9.

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