1. A pixel circuit, comprising: the device comprises a data writing module, a photoelectric sensing device, a storage module, a sensing switch module, a driving module and a light-emitting device;

the data writing module is used for providing a signal sent by a data line to the control end of the driving module under the control of the first control signal end;

the sensing switch module is used for providing a first initialization voltage signal sent by a sensing line to a first end of the photoelectric sensing device under the control of a second control signal end;

the photoelectric sensing device is used for generating a photo-generated current signal according to incident light under the control of a third control signal end and providing the photo-generated current signal to the control end of the driving module;

the storage module is used for stabilizing the voltage between the control end of the driving module and the output end of the driving module;

the driving module is used for driving the light-emitting device to emit light under the control of the potential of the control end.

2. The pixel circuit of claim 1, wherein the photo-sensing device comprises: a first transistor and a photo-sensing element;

a gate of the first transistor is connected to the third control signal terminal, a first pole of the first transistor is connected to the output terminal of the driving module or the cathode of the light emitting device, a second pole of the first transistor is connected to the first pole of the photo sensing element, and the second pole of the photo sensing element is connected to the control terminal of the driving module; alternatively, the first and second electrodes may be,

the gate of the first transistor is connected to the third control signal terminal, the first pole of the first transistor is connected to the second pole of the photo sensing element, the second pole of the first transistor is connected to the control terminal of the driving module, and the first pole of the photo sensing element is connected to the output terminal of the driving module or the cathode of the light emitting device.

3. The pixel circuit according to claim 2, wherein the photo-sensing element is a diode or an oxide thin film transistor; and the grid electrode of the oxide thin film transistor is connected with a fourth control signal end, or the grid electrode of the oxide thin film transistor is connected with the first pole of the oxide thin film transistor.

4. The pixel circuit according to claim 2 or 3, wherein the photo-sensing device further comprises: a second transistor;

when the second pole of the photoelectric sensing element is connected with the control end of the driving module, the second pole of the second transistor is connected with the first pole of the first transistor and the output end of the driving module, the first pole of the second transistor is connected with the cathode of the light-emitting device, and the grid of the second transistor is connected with a fifth control signal end; alternatively, the first and second electrodes may be,

when the second pole of the first transistor is connected to the control terminal of the driving module, the second pole of the second transistor is connected to the first pole of the photo-sensing element and the output terminal of the driving module, the first pole of the second transistor is connected to the cathode of the light emitting device, and the gate of the second transistor is connected to a fifth control signal terminal.

5. The pixel circuit according to any one of claims 1 to 3, further comprising: the first light-emitting control module and/or the second light-emitting control module;

the first light-emitting control module is used for supplying the voltage of the output end of the driving module to the anode of the light-emitting device under the control of a first light-emitting control signal end;

the second light-emitting control module is used for providing the signal of the first power supply end to the driving module under the control of the second light-emitting control signal end.

6. The pixel circuit according to claim 5, wherein the driving module comprises: a drive transistor;

the data writing module comprises a third transistor, wherein a first pole of the third transistor is connected with the data line, a grid electrode of the third transistor is connected with the first control signal end, and a second pole of the third transistor is connected with the grid electrode of the driving transistor;

the second light-emitting control module comprises a fourth transistor, a first electrode of the fourth transistor is connected with the first power supply end, a grid electrode of the fourth transistor is connected with the second light-emitting control signal end, and a second electrode of the fourth transistor is connected with the first electrode of the driving transistor;

the first light emitting control module comprises a fifth transistor, wherein a first pole of the fifth transistor is connected with a second pole of the driving transistor, a grid electrode of the fifth transistor is connected with the first light emitting control signal end, and a second pole of the fifth transistor is connected with an anode of the light emitting device;

the storage module includes a capacitor, one end of the capacitor is connected to an anode of the light emitting device, and the other end of the capacitor is connected to a gate of the driving transistor;

the sensing switch module includes: a sensing switch crystal, a first pole of the sensing switch crystal is connected with the sensing line, a grid of the sensing switch crystal is connected with the second control signal end, and a second pole of the sensing switch crystal is connected with the anode of the light emitting device.

7. A display panel, comprising: a plurality of pixel circuits arranged in a matrix, the pixel circuits being as claimed in any one of claims 1 to 6.

8. A display device, comprising: a sensing unit and the display panel of claim 7, the sensing unit being connected with a pixel circuit in the display panel by a sensing line.

9. A sensing driving method based on a pixel circuit is characterized by comprising the following steps:

during initialization, the data writing module provides a signal sent by the data line to the control end of the driving module under the control of the first control signal end so as to set the voltage of the control end of the driving module as a target initialization voltage; the sensing switch module provides a first initialization voltage signal sent by a sensing line to a first end of the photoelectric sensing device under the control of a second control signal end;

during sensing, the photoelectric sensing device generates a photo-generated current signal according to incident light under the control of a third control signal end and provides the photo-generated current signal to the control end of the driving module;

during resetting, the data writing module supplies a signal sent by the data line to the control end of the driving module under the control of the first control signal end so as to reset the pixel circuit to a state before light sensing operation.

10. The sense driving method according to claim 9,

during the initialization period, the signal sent by the data line is a target initialization signal corresponding to the target initialization voltage;

during the reset period, the signal sent by the data line is a data signal, and the storage module is used for storing the data voltage corresponding to the data signal.

Background

With the improvement of the demand of people for information security, the biometric identification technology is more and more concerned by various fields. Among the biometric technologies, fingerprint recognition technology has become the most interesting and widely applied technology due to its practical applicability, and especially for handheld mobile devices such as mobile phones and tablet computers, fingerprint recognition has slowly become an indispensable part.

On the existing market, the main fingerprint identification technology is embedded into independent button or is embedded into the display screen with the fingerprint identification module. Because present mobile device terminal tends to comprehensive screen and frivolous, the inside usable space of equipment terminal reduces day by day, is difficult to vacate corresponding space and sets up the fingerprint identification module, consequently takes place by hand through the screen fingerprint identification scheme under the integrated fingerprint identification device under the screen. The conventional fingerprint identification device is disposed at the rear of the lower portion of the display panel, occupies an extra space, and how to integrate an optical fingerprint with the display panel is a technical problem to be solved urgently by those skilled in the art.

Disclosure of Invention

In view of the above, in order to solve the above technical problems or some of the technical problems, embodiments of the present application provide a pixel circuit, a display panel, a device and a sensing driving method.

In a first aspect, an embodiment of the present application provides a pixel circuit, including: the device comprises a data writing module, a photoelectric sensing device, a storage module, a sensing switch module, a driving module and a light-emitting device;

the data writing module is used for providing a signal sent by a data line to the control end of the driving module under the control of the first control signal end;

the sensing switch module is used for providing a first initialization voltage signal sent by a sensing line to a first end of the photoelectric sensing device under the control of a second control signal end;

the photoelectric sensing device is used for generating a photo-generated current signal according to incident light under the control of a third control signal end and providing the photo-generated current signal to the control end of the driving module so as to reduce the potential of the control end of the driving module;

the storage module is used for stabilizing the voltage between the control end of the driving module and the output end of the driving module;

the driving module is used for driving the light-emitting device to emit light under the control of the potential of the control end.

In one possible embodiment, the photo-sensing device comprises: a first transistor and a photo-sensing element;

a gate of the first transistor is connected to the third control signal terminal, a first pole of the first transistor is connected to the output terminal of the driving module or the cathode of the light emitting device, a second pole of the first transistor is connected to the first pole of the photo sensing element, and the second pole of the photo sensing element is connected to the control terminal of the driving module; alternatively, the first and second electrodes may be,

the gate of the first transistor is connected to the third control signal terminal, the first pole of the first transistor is connected to the second pole of the photo sensing element, the second pole of the first transistor is connected to the control terminal of the driving module, and the first pole of the photo sensing element is connected to the output terminal of the driving module or the cathode of the light emitting device.

In one possible embodiment, the photo-sensing element is a diode or an oxide thin film transistor; and the grid electrode of the oxide thin film transistor is connected with a fourth control signal end, or the grid electrode of the oxide thin film transistor is connected with the first pole of the oxide thin film transistor.

In one possible embodiment, the photo-sensing device further includes: a second transistor;

when the second pole of the photoelectric sensing element is connected with the control end of the driving module, the second pole of the second transistor is connected with the first pole of the first transistor and the output end of the driving module, the first pole of the second transistor is connected with the cathode of the light-emitting device, and the grid of the second transistor is connected with a fifth control signal end; alternatively, the first and second electrodes may be,

when the second pole of the first transistor is connected to the control terminal of the driving module, the second pole of the second transistor is connected to the first pole of the photo-sensing element and the output terminal of the driving module, the first pole of the second transistor is connected to the cathode of the light emitting device, and the gate of the second transistor is connected to a fifth control signal terminal.

In one possible implementation, the pixel circuit further includes: the first light-emitting control module and/or the second light-emitting control module; the first light-emitting control module is used for supplying the voltage of the output end of the driving module to the anode of the light-emitting device under the control of a first light-emitting control signal end; the second light-emitting control module is used for providing the signal of the first power supply end to the driving module under the control of the second light-emitting control signal end.

In one possible embodiment, the drive module comprises: a drive transistor; the data writing module comprises a third transistor, wherein a first pole of the third transistor is connected with the data line, a grid electrode of the third transistor is connected with the first control signal end, and a second pole of the third transistor is connected with the grid electrode of the driving transistor.

In one possible implementation, the second light-emitting control module includes a fourth transistor, a first pole of the fourth transistor is connected to the first power terminal, a gate of the fourth transistor is connected to the second light-emitting control signal terminal, and a second pole of the fourth transistor is connected to the first pole of the driving transistor.

In one possible embodiment, the first light emission control module includes a fifth transistor, a first pole of the fifth transistor is connected to the second pole of the driving transistor, a gate of the fifth transistor is connected to the first light emission control signal terminal, and a second pole of the fifth transistor is connected to the anode of the light emitting device.

In one possible embodiment, the storage module includes a capacitor, one end of the capacitor is connected to an anode of the light emitting device, and the other end of the capacitor is connected to a gate of the driving transistor.

In one possible embodiment, the sensing switch module includes: a sensing switch crystal, a first pole of the sensing switch crystal is connected with the sensing line, a grid of the sensing switch crystal is connected with the second control signal end, and a second pole of the sensing switch crystal is connected with the anode of the light emitting device.

In a second aspect, an embodiment of the present application provides a display panel, which includes a plurality of pixel circuits arranged in a matrix, where the pixel circuit is the pixel circuit described in any one of the first aspect.

In a third aspect, an embodiment of the present application provides a display device, including: and a display panel as described in the third aspect above, wherein the sensing unit is connected to the pixel circuit in the display panel by a sensing line.

In a fourth aspect, an embodiment of the present application provides a sensing driving method based on a pixel circuit, including:

during initialization, the data writing module provides a signal sent by the data line to the control end of the driving module under the control of the first control signal end so as to set the voltage of the control end of the driving module as a target initialization voltage; the sensing switch module provides a first initialization voltage signal sent by a sensing line to the first end of the photoelectric sensing device under the control of the second control signal end so as to set the voltage of the first end of the photoelectric sensing device as a first initialization voltage;

during sensing, the photoelectric sensing device generates a photo-generated current signal according to incident light under the control of a third control signal end, and provides the photo-generated current signal to the control end of the driving module so as to reduce the potential of the control end of the driving module;

during resetting, the data writing module supplies a signal sent by the data line to the control end of the driving module under the control of the first control signal end so as to reset the pixel circuit to a state before light sensing operation.

In a possible implementation manner, during the initialization period, the signal sent by the data line is a target initialization signal corresponding to the target initialization voltage; during the reset period, the signal sent by the data line is a data signal, and the storage module is used for storing the data voltage corresponding to the data signal.

The pixel circuit, the display panel, the device and the sensing driving method provided by the embodiment of the application provide the first initialization voltage signal sent by the sensing line to the photoelectric sensing device under the control of the second control signal end through the sensing switch module, and the photoelectric sensing device transmits the photo-generated current signal generated according to incident light to the control end of the driving module under the control of the third control signal end, so that the opening degree of the driving module is related to the light intensity, the photoelectric sensing unit is combined with the external compensation driving circuit, devices required by the external compensation driving circuit are reduced, the space occupied by the external compensation driving circuit is reduced, and more space is saved for the photoelectric sensing unit.

In addition, the embodiment of the application provides the initialization signal for the photoelectric sensing device through the optical line, and the initialization signal is not required to be provided by an additional signal line, so that the space occupied by the signal line is saved, and the cost is reduced.

Drawings

Fig. 1 is a schematic structural diagram of a pixel circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a pixel circuit according to an alternative example of the present application;

fig. 3 is a schematic structural diagram of another pixel circuit provided in an example of the present application;

fig. 4 is a schematic structural diagram of a pixel circuit according to an example of the present application;

fig. 5 is a schematic structural diagram of another pixel circuit provided in an example of the present application;

fig. 6 is a schematic structural diagram of a pixel circuit according to another alternative example of the present application;

fig. 7 is a schematic structural diagram of a pixel circuit according to still another example of the present application;

fig. 8 is a schematic structural diagram of a pixel circuit according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a pixel circuit according to another embodiment of the present application;

fig. 10 is a schematic structural diagram of a pixel circuit according to yet another embodiment of the present application;

fig. 11 is a timing diagram illustrating a sensing driving of a pixel circuit according to yet another embodiment of the present application;

fig. 12 is a schematic diagram illustrating a step of a sensing driving method based on a pixel circuit according to an embodiment of the present disclosure;

fig. 13 is a schematic structural diagram of a display device according to an embodiment of the present disclosure;

fig. 14 is a schematic structural diagram of another display device provided in this embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

For the purpose of facilitating understanding of the embodiments of the present application, the following description will be made in terms of specific embodiments with reference to the accompanying drawings, which are not intended to limit the embodiments of the present application.

Fig. 1 is a schematic structural diagram of a pixel circuit according to an embodiment of the present disclosure, where the pixel circuit includes: the data writing module 110, the photo sensing device 120, the memory module 130, the sensing switch module 140, the driving module 150, and the light emitting device OLED. The data writing module 110 is configured to provide a signal sent by the data line DLj to the control terminal of the driving module 150 under the control of the first control signal terminal Gm; the Sensing switch module 140 is configured to provide a first initialization voltage signal sent by a Sensing line Sensing to the first end of the photo Sensing device 120 under the control of the second control signal end Rm; the photo sensing device 120 is configured to generate a photo-generated current signal according to incident light under the control of a third control signal terminal Gn, and provide the photo-generated current signal to the control terminal of the driving module 150; the storage module 130 is configured to stabilize a voltage between the control terminal of the driving module 150 and the output terminal of the driving module 150; the driving module 150 is configured to drive the light emitting device OLED to emit light under the control of the potential of the control terminal.

Specifically, when the first control signal terminal Gm outputs an effective first control signal, the data writing module 110 may provide a signal sent by the data line DLj to the control terminal of the driving module 150 according to the effective first control signal, that is, the signal sent by the data line DLj is transmitted to the control terminal of the driving module 150 through the data writing module 110, so as to write the signal voltage provided by the data line DLj into the control terminal of the driving module 150. For example, during the initialization Ti, the initialization voltage Vrst is supplied to the data line DLj, and the data writing module 110 may provide the initialization voltage Vrst signal sent by the data line DLj as a target initialization signal to the control terminal of the driving module 150 according to an effective first control signal, so as to provide the initialization voltage Vrst to the control terminal of the driving module 150, that is, the control terminal of the driving module 150 is reset to the initialization voltage Vrst; for another example, during the reset period Trst, the Data line DLj may supply the Data signal Data of the current frame, and the Data writing module 110 may provide the Data signal Data to the control terminal of the driving module 150 according to the valid first control signal, so as to write the Data voltage Vdata corresponding to the Data signal Data into the control terminal of the driving module 150, so that the storage module 130 may store the Data voltage Vdata supplied through the Data line DLj, and further, the pixel circuit is reset to the state before the light sensing operation. When the second control signal terminal Rm provides an active second control signal, the Sensing switch module 140 may provide a signal emitted by the Sensing line Sensing to the first terminal of the photo Sensing device 120 according to the active second control signal, for example, the Sensing switch module 140 may provide a first initialization voltage signal emitted by the Sensing line Sensing to the first terminal of the photo Sensing device 120 according to the active second control signal during the initialization Ti, so as to reset the voltage of the first terminal of the photo Sensing device 120 to a first initialization voltage Vint, where the first initialization voltage Vint is the voltage of the first initialization voltage signal.

In the embodiment of the present application, the first terminal of the photo sensing device 120 may be connected to the output terminal of the driving module 150, and the voltage of the control terminal of the driving module 150 is maintained by the storage module 130 during the sensing period Ts; also, the photo sensing device 120 is continuously illuminated during the sensing period Ts to generate a photo-generated current such that the voltage at the output terminal of the driving module 150 gradually decreases. Specifically, the photo sensing device 120 generates the photo-generated current signal according to the incident light under the control of the third control signal terminal Gn, for example, during the sensing period Ts, the third control signal terminal Gn provides an effective third control signal, so that the photo sensing device 120 can generate a predetermined amount of current in response to the voltage supplied to its counter electrode and the intensity of the incident light, and the current generated by the photo sensing device 120 can be supplied to the control terminal of the driving module 150, i.e., the photo-generated current signal is supplied to the control terminal of the driving module 150, so that the voltage of the control terminal of the driving module 150 is changed, and the turn-on degree of the driving module 150 is related to the intensity of the light. The opening degree of the driving module 150 can be determined by the voltage of the control terminal, and the driving module 150 can amplify the signal, so that the voltage of the control terminal of the driving module 150 can determine the current magnitude on the Sensing line Sensing, and further the Sensing unit disposed in the display device can sense the voltage or the current on any node of the Sensing line Sensing, thereby Sensing the touch or the fingerprint of the user.

It can be seen that the pixel circuit provided in the embodiment of the present application provides the first initialization voltage signal sent by the Sensing line Sensing to the photo Sensing device 120 through the Sensing switch module 140 under the control of the second control signal terminal Rm, and the photo Sensing device 120 transmits the photo-generated current signal generated according to the incident light to the control terminal of the driving module 150 under the control of the third control signal terminal Gn, so that the turn-on degree of the driving module 150 is related to the intensity of light, so that the photo Sensing device 120 serving as the photo Sensing unit is combined with the external compensation driving circuit, and the devices required by the external compensation driving circuit are reduced, thereby reducing the space occupied by the external compensation driving circuit and saving more space for the photo Sensing unit. Further, in the embodiment of the present application, the optical line provides the initialization signal for the photoelectric sensing device 120, and an additional signal line is not needed to provide the initialization signal, so that the space occupied by the signal line can be saved, and the cost can be reduced.

In a specific implementation, the photo sensing device 120 in the embodiment of the present application may include a first transistor T1 and a photo sensing element; the gate of the first transistor T1 is connected to the third control signal terminal Gn, such that the first transistor T1 is turned on during a period when the third control signal terminal Gn provides an active third control signal; the photoelectric sensing element can sense incident light and change electrical characteristics according to the intensity of the incident light to generate photo-generated current.

In an actual process, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the output terminal of the driving module 150 or the cathode of the light emitting device OLED, the second pole of the first transistor T1 is connected to the first pole of the photo-sensing element, and the second pole of the photo-sensing element is connected to the control terminal of the driving module 150; alternatively, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the second pole of the photo sensing element, the second pole of the first transistor T1 is connected to the control terminal of the driving module 150, and the first pole of the photo sensing element is connected to the output terminal of the driving module 150 or the cathode of the light emitting device OLED. The photo-sensing element may be formed by a transistor or an element with high photosensitivity, for example, the photo-sensing element may be a diode, an Oxide Thin Film Transistor (OTFT), and the like, which is not limited in this embodiment.

As an optional example of the present application, the photo sensing device 120 includes: in the case of the first transistor T1 and a diode, as shown in fig. 2, a gate of the first transistor T1 may be connected to the third control signal terminal Gn, a first pole of the first transistor T1 may be connected to the output terminal of the driving module 150, a second pole of the first transistor T1 may be connected to an anode of the diode, and a cathode of the diode may be connected to the control terminal of the driving module 150; alternatively, as shown in fig. 3, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the cathode of the diode, the second pole of the first transistor T1 is connected to the control terminal of the driving module 150, and the anode of the diode is connected to the output terminal of the driving module 150. The first transistor T1 can be a switching transistor in the photo Sensing device 120 to be turned on during the period that the third control signal terminal Gn provides the valid third control signal, so that the photo-generated current signal generated by the diode as the photo Sensing element during the Sensing period Ts can be provided to the control terminal of the driving module 150, thereby gradually decreasing the voltage of the control terminal of the driving module 150 and changing the current magnitude of the Sensing line Sensing, such as changing the current of the Sensing line Sensing from the first current V-bright to the second current V-dark.

It is noted that the first current V-bright may be a current of the Sensing line Sensing when light reflected by the ridges of the fingerprint is incident on the photo Sensing device 120, and the second current V-dark may be a current of the Sensing line Sensing when light reflected by the valleys of the fingerprint is incident on the photo Sensing device 120.

Of course, the first transistor T1 and the diode in the photo sensing device 120 may be connected with other device modules of the pixel circuit in other manners, and the embodiment of the present application is not limited thereto. For example, as shown in fig. 4, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the cathode of the light emitting device OLED, the second pole of the first transistor T1 is connected to the anode of the diode, and the cathode of the diode is connected to the control terminal of the driving module 150; as another example, as shown in fig. 5, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the cathode of the diode, the second pole of the first transistor T1 is connected to the control terminal of the driving module 150, and the anode of the diode is connected to the cathode of the light emitting device OLED.

In an alternative embodiment, the photo-sensing element is a diode or an oxide thin film transistor, and when the oxide thin film transistor is used as the photo-sensing element, the gate of the oxide thin film transistor may be connected to the fourth control signal terminal Gs, so that the oxide thin film transistor may generate a predetermined amount of current according to the intensity of the incident light under the control of the fourth control signal terminal Gs, thereby generating the photo-generated current signal. Alternatively, the gate electrode of the oxide thin film transistor is connected to the first electrode of the oxide thin film transistor, so that the oxide thin film transistor can generate a photo-generated current signal according to the intensity of incident light during the sensing period Ts.

As another alternative example of the present application, in the case that the photo-sensing device 120 includes a first transistor T1 and an oxide thin film transistor T6, as shown in fig. 6, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the output terminal of the driving module 150, the second pole of the first transistor T1 is connected to the first pole of the oxide thin film transistor T6, the second pole of the oxide thin film transistor T6 is connected to the control terminal of the driving module 150, and the gate of the oxide thin film transistor T6 is connected to the fourth control signal terminal Gs; alternatively, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the second pole of the oxide thin film transistor T6, the second pole of the first transistor T1 is connected to the control terminal of the driving module 150, the first pole of the oxide thin film transistor T6 is connected to the output terminal of the driving module 150, and the gate of the oxide thin film transistor T6 is connected to the fourth control signal terminal Gs. The oxide thin film transistor T6 can generate a predetermined amount of current according to the intensity of the incident light under the control of the fourth control signal terminal Gs, so as to generate a photo-generated current signal.

Specifically, when the fourth control signal terminal Gs provides an effective light emission control signal, as during the sensing period TS, the fourth control signal terminal Gs outputs an effective four control signal to the gate of the oxide thin film transistor T6, so that the oxide thin film transistor T6 generates a predetermined amount of current by the intensity of incident light, i.e., generates a photo-generated current signal. The first transistor T1 can be used as a switching transistor in the photo Sensing device 120 to be turned on during the period when the third control signal terminal Gn provides the effective third control signal, so that the photo-generated current signal generated by the oxide thin film transistor T6 as the photo Sensing element during the Sensing period Ts can be provided to the control terminal of the driving module 150, thereby gradually reducing the voltage of the control terminal of the driving module 150 and further changing the current magnitude of the Sensing line Sensing.

Of course, the first transistor T1 and the oxide thin film transistor T6 in the photo-sensing device 120 may be connected to other device modules of the pixel circuit in other manners, which is not particularly limited in this embodiment of the application. For example, the gate of the oxide thin film transistor T6 and the first pole of the oxide thin film transistor T6 may both be connected to the output terminal of the driving module 150 through a first transistor T1, as shown in fig. 7, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the output terminal of the driving module 150, the second pole of the first transistor T1 is connected to the first pole of the oxide thin film transistor T6, the second pole of the oxide thin film transistor T6 is connected to the control terminal of the driving module 150, and the gate of the oxide thin film transistor T6 is connected to the first pole of the oxide thin film transistor T6. For another example, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the second pole of the oxide thin film transistor T6, the second pole of the first transistor T1 is connected to the control terminal of the driving module 150, and the first pole of the oxide thin film transistor T6 is connected to the output terminal of the driving module 150 and the gate of the oxide thin film transistor T6.

On the basis of the above embodiments, optionally, the photo sensing device 120 in the embodiment of the present application may further include a second transistor T2. A first pole of the second transistor T2 is connected to the cathode of the light emitting device OLED, a second pole of the second transistor T2 is connected to the output terminal of the driving module 150, and a gate of the second transistor T2 is connected to a fifth control signal terminal Go. The second transistor T2 may provide the signal of the cathode of the light emitting device OLED to the first transistor T1 or the photo sensing element under the control of the fifth control signal terminal Go, so that the signal of the cathode of the light emitting device OLED may be provided to the photo sensing element connected to the first transistor T1 through the turned-on second transistor T2 during the initialization Ti, that is, the initialization signal is provided from the cathode of the light emitting device OLED, and an additional signal line is not required to provide the initialization signal to the photo sensing device 120, thereby avoiding the problem of an increase in space of the display device caused by the addition of the additional signal line.

Specifically, when the second pole of the photo-sensing element is connected to the control terminal of the driving module 150, the second pole of the second transistor T2 is connected to the first pole of the first transistor T1 and the output terminal of the driving module 150, the first pole of the second transistor T2 is connected to the cathode of the light emitting device OLED, and the gate of the second transistor T2 is connected to the fifth control signal terminal Go, so that the second transistor T2 can supply the signal of the cathode of the light emitting device OLED to the first transistor T1 under the control of the fifth control signal terminal Go, so that the signal of the cathode of the light emitting device OLED can be supplied to the photo-sensing element connected to the first transistor T1 through the turned-on second transistor T2 during the initialization Ti, that is, the initialization signal is supplied from the cathode of the light emitting device OLED, without an additional signal line for supplying the initialization signal to the photo-sensing device 120, the problem that the space of the display device is increased due to the addition of extra signal lines is avoided.

When the second pole of the first transistor T1 is connected to the control terminal of the driving module 150, the second pole of the second transistor T2 is connected to the first pole of the photo-sensing element and the output terminal of the driving module 150, the first pole of the second transistor T2 is connected to the cathode of the light emitting device OLED, and the gate of the second transistor T2 is connected to the fifth control signal terminal Go, so that the second transistor T2 can supply the signal of the cathode of the light emitting device OLED to the first pole of the photo-sensing element and the output terminal of the driving module 150 under the control of the fifth control signal terminal Go, so that the signal of the cathode of the light emitting device OLED can be supplied to the photo-sensing element through the turned-on second transistor T2 during the initialization Ti, that is, the initialization signal is supplied from the cathode of the light emitting device OLED, without an additional signal line for supplying the initialization signal to the photo-sensing device 120, the problem that the space of the display device is increased due to the addition of extra signal lines is avoided.

As an example of the present application, the photo sensing device 120 includes: in the case of the first transistor T1, the diode and the second transistor T2, as shown in fig. 8, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the output terminal of the driving module 150 and the second pole of the second transistor T2, the second pole of the first transistor T1 is connected to the anode of the diode, the cathode of the diode is connected to the control terminal of the driving module 150, the first pole of the second transistor T2 is connected to the cathode of the light emitting device OLED, and the gate of the second transistor T2 is connected to the fifth control signal terminal Go; alternatively, the gate of the first transistor T1 is connected to the third control signal terminal Gn, the first pole of the first transistor T1 is connected to the cathode of the diode, the second pole of the first transistor T1 is connected to the control terminal of the driving module 150, the anode of the diode is connected to the output terminal of the driving module 150 and the second pole of the second transistor T2, the first pole of the second transistor T2 is connected to the cathode of the light emitting device OLED, and the gate of the second transistor T2 is connected to the fifth control signal terminal Go.

On the basis of the foregoing embodiment, optionally, the pixel circuit in the embodiment of the present application may further include: the first light emission control module 160 and/or the second light emission control module 170. The first light emitting control module 160 is configured to provide the voltage at the output terminal of the driving module 150 to the anode of the light emitting device OLED under the control of a first light emitting control signal terminal E1; the second light-emitting control module 170 is used for providing the signal of the first power terminal VDD to the driving module 150 under the control of the second light-emitting control signal terminal E2.

Specifically, when the first light emitting control signal terminal E1 provides an effective light emitting control signal, as shown in fig. 7, the first light emitting control module 160 may provide the voltage at the output terminal of the driving module 150 to the anode of the light emitting device OLED, so that the driving signal output by the driving module 150 may be transmitted to the light emitting device OLED through the first light emitting control module 160 to drive the light emitting device OLED to emit light.

When the second light-emitting control module 170 provides an effective light-emitting control signal at the second light-emitting control signal terminal E2, as shown in fig. 9, a signal of the first power terminal VDD may be provided to the driving module 150 based on the effective light-emitting control signal, so that the driving module 150 drives the light-emitting device OLED to emit light under the control of the potential of the control terminal.

Further, the driving module 150 in the embodiment of the present application may include: a driving transistor T0; the data writing module 110 includes a third transistor T3, a first pole of the third transistor T3 is connected to the data line DLj, a gate of the third transistor T3 is connected to the first control signal terminal Gm, and a second pole of the third transistor T3 is connected to the gate of the driving transistor T0. Specifically, when the first control signal terminal Gm provides an active first control signal, the third transistor T3 is turned on, and a signal from the data line DLj can be transmitted to the gate of the driving transistor T0 through the third transistor T3, so that the signal voltage provided by the data line DLj can be written into the gate of the driving transistor T0. For example, during the initialization Ti, the first control signal terminal Gm provides an active first control signal, the third transistor T3 is turned on, and the initialization voltage Vrst signal provided by the data line DLj can be transmitted to the gate of the driving transistor T0 through the third transistor T3, so that the voltage of the node a is set to the initialization voltage Vrst, i.e., VA is Vrst, where VA represents the voltage of the node a.

Further, the second light emission control module 170 in the embodiment of the present application includes a fourth transistor T4, a first electrode of the fourth transistor T4 is connected to the first power terminal VDD, a gate of the fourth transistor T4 is connected to the second light emission control signal terminal EM2, and a second electrode of the fourth transistor T4 is connected to the first electrode of the driving transistor T0. Specifically, when the second light emission control signal terminal EM2 provides an active light emission control signal, the fourth transistor T4 is turned on, and the signal of the first power terminal VDD is transmitted to the first pole of the driving transistor T0 through the fourth transistor T4, so that the driving transistor T0 drives the light emitting device OLED to emit light under the control of the potential of the node a.

In an actual process, during a light emitting stage of the light emitting device OLED, the first light emitting control module 160 may transmit the driving signal output by the driving module 150 to the light emitting device OLED according to the effective light emitting control signal, so as to drive the light emitting device OLED to emit light. Further, the first light emission control module 160 in the embodiment of the present application includes a fifth transistor T5, a first pole of the fifth transistor T5 is connected to the second pole of the driving transistor T0, a gate of the fifth transistor T5 is connected to the first light emission control signal terminal EM1, and a second pole of the fifth transistor T5 is connected to the anode of the light emitting device OLED. Specifically, when the first light emission control signal terminal E1 provides an active light emission control signal, the fifth transistor T5 is turned on, and the driving current signal output from the driving transistor T0 is transmitted to the light emitting device OLED through the fifth transistor T5, so that the light emitting device OLED emits light.

Further, the storage module 130 in the embodiment of the present application includes a capacitor Cst, as shown in fig. 2, one end of the capacitor Cst is connected to the anode of the light emitting device OLED, and the other end of the capacitor Cst is connected to the gate of the driving transistor T0. During the sensing period Ts, the degree of turning on of the driving transistor T0 may be gradually decreased, and even the driving transistor T0 may be turned off, and the gate voltage of the driving transistor T0 may be maintained by the capacitor Cst.

Further, the sensing switch module 140 in the embodiment of the present application includes: a sensing switch crystal T7, a first pole of the sensing switch crystal T7 being connected with the sensing line, a gate of the sensing switch crystal T7 being connected with the second control signal terminal Rm, and a second pole of the sensing switch crystal T7 being connected with an anode of the light emitting device OLED.

In practical implementation, the first pole and the second pole of the transistor in this embodiment may be the source or the drain of the transistor, and their functions may be interchanged according to the type of the transistor and the input signal, and are not specifically distinguished herein. The driving transistor T0 may be an OTFT or a Metal Oxide Semiconductor field effect transistor (MOS), which is not limited in this embodiment.

The following describes a sensing driving process of the pixel circuit provided by the embodiment of the invention, taking the pixel circuit shown in fig. 10 as an example. As an example of the present application, in the pixel circuit shown in fig. 10, the driving transistor and all the transistors are N-type transistors, and each of the transistors is turned on by a high level and turned off by a low level.

In a specific implementation, the present example may divide the pixel circuit based sensing driving process into three periods; the first period is during the initialization Ti, the second period is during the fingerprint sensing period Ts, and the third period is during the reset period Trst.

Specifically, during the initialization Ti, the initialization voltage Vrst is supplied to the data line DLj, and the initialization voltage Vrst may be supplied to the node a, that is, VA — Vrst. Further, during initialization, the first initialization voltage Vint may be supplied to the Sensing line Sensing, and the Sensing switch transistor T7 and the first transistor T1 may be turned on, so that a signal emitted from the Sensing line Sensing may be transmitted to the node B through the turned-on Sensing switch transistor T7, i.e., the first initialization voltage Vint may be supplied to the node B.

Specifically, during the initialization period, the first control signal output from the first control signal terminal Gm is a high level signal, as shown in fig. 11, the third transistor T3 is turned on, the initialization voltage Vrst can be supplied to the node a, that is, the voltage of the node a can be reset to the initialization voltage Vrst, thereby resetting the gate voltage of the driving transistor T0 to the initialization voltage Vrst; the second control signal provided by the second control signal terminal Rm is a high level signal, and the sensing switch transistor T7 may be turned on, so that the voltage of the node B may be reset to the first initialization voltage Vint. As the voltage of the node a and the voltage of the node B are initialized, a voltage corresponding to a difference between the initialization voltage Vrst and the first initialization voltage Vint may be charged into the capacitor Cst.

During the sensing period Ts, the third transistor T3 may be turned off by the first control signal Gm, as shown in fig. 11, the first control signal output by the first control signal terminal Gm is a low level signal, and the third transistor T3 is turned off; the third control signal provided by the third control signal terminal Gn and the second control signal provided by the second control signal terminal Rm are both high level signals, and the first transistor T1 and the sensing switch transistor T7 are turned on, i.e., the first transistor T1 and the sensing switch transistor T7 are turned on by the third control signal and the second control signal, respectively. During the sensing period Ts, the turn-on degree of the driving transistor T0 may gradually decrease until the driving transistor T0 is turned off, and the voltage of the node a may be maintained by the capacitor Cst.

Specifically, during the sensing period Ts, the photo sensing device 120 is continuously illuminated and a photo-generated current may be generated such that the voltage of the node a gradually decreases, as during the sensing period Ts, the diode in the photo sensing device 120 generates a predetermined amount of current in response to the voltage supplied to its counter electrode and the intensity of incident light. The current generated from the photo sensing device 120 may be supplied to the gate of the driving transistor T0, so that the voltage of the node a is varied. The voltage at the node a varies depending on the current generated from the photo sensing device 120, and the degree of turning on the driving transistor T0 can be determined by the voltage at the node a. The driving transistor T0 can amplify the signal, so that the voltage at the node a determines the current on the Sensing line Sensing, and the current on the Sensing line Sensing can also change from the first current V-bright to the second current V-dark. The Sensing unit provided in the display device may sense a user's touch or fingerprint by Sensing a voltage or current on any node of the Sensing line Sensing.

During the reset period Trst, the pixel circuit may be reset to perform a display operation of a subsequent frame. Therefore, during the reset period Trst, the first control signal output from the first control signal terminal Gm and the second control signal provided from the second control signal terminal Rm in this example are both high level signals, so that the third transistor T3 and the sensing switch transistor T7 may be turned on by the first control signal and the second control signal, respectively, and the third control signal provided from the third control signal terminal Gn in this example is a low level signal, and the first transistor T1 is turned off, so that the pixel circuit may be reset to a state before the light sensing operation. Specifically, during the reset period Trst, the Data line DLj may supply a Data signal Data of a current frame, which may be transmitted to the node a through the turned-on third transistor T3, so that the voltage of the node a becomes a Data voltage Vdata, i.e., VA — Vdata. Wherein the capacitor Cst may store the data voltage supplied through the data line DLj, so that the pixel circuit is reset to a state before the light sensing operation.

It should be noted that, in the present example, the first light emitting control signal terminal E1 provides the light emitting control signal which can be a low level signal during the sensing driving process, so that the fifth transistor T5 is turned off. Specifically, during the initialization Ti, during the sensing period Ts, and during the reset period Trst, as shown in fig. 11, the first light emitting control signal terminal E1 outputs a low level signal such that the fifth transistor T5 is turned off.

In summary, the embodiment of the present application provides the initialization signal for the photoelectric sensing device through the optical line, and an additional signal line is not needed to provide the initialization signal, so that the space occupied by the signal line is saved, and the cost is reduced. .

Further, the embodiment of the present application also provides a sensing driving method based on a pixel circuit, which can be applied to a display device. As shown in fig. 12, the sensing driving method based on the pixel circuit provided in the embodiment of the present application may specifically include:

s1201, during initialization, the data writing module provides a signal sent by the data line to the control end of the driving module under the control of the first control signal end, so that the voltage of the control end of the driving module is set as a target initialization voltage; the sensing switch module provides a first initialization voltage signal sent by a sensing line to a first end of the photoelectric sensing device under the control of a second control signal end;

s1202, during sensing, the photoelectric sensing device generates a photo-generated current signal according to incident light under the control of a third control signal end, and provides the photo-generated current signal to a control end of the driving module;

s1203, during the reset period, the data writing module provides the signal sent by the data line to the control end of the driving module under the control of the first control signal end, so as to reset the pixel circuit to the state before the light sensing operation.

During the initialization period, a signal sent by the data line is a target initialization signal corresponding to the target initialization voltage; during the reset period, the signal sent by the data line is a data signal, and the storage module is used for storing the data voltage corresponding to the data signal.

Further, the embodiment of the application provides a display panel. The display panel in the embodiment of the present application includes: a plurality of pixel circuits arranged in a matrix, the pixel circuit being any one of the pixel circuits provided in the embodiments of the present invention. Since the principle of the display panel to solve the problem is similar to the pixel circuit, the implementation of the pixel circuit in the display panel can be referred to the implementation of the pixel circuit in the foregoing example, and repeated descriptions are omitted.

An embodiment of the present invention further provides a display device, including: the sensing unit and the display panel provided by the embodiment of the invention. As shown in fig. 13, the display device 1300 includes: a display panel 1310 and a sensing unit 1320, wherein the sensing unit 1320 can be connected to a pixel circuit in the display panel 1310 through a sensing line. The display panel may be the display panel described in the above embodiments. In a specific implementation, the display device may be a display, a mobile phone, a television, a notebook computer, electronic paper, a digital photo frame, a navigator, an all-in-one machine, and the like, which is not particularly limited in this application.

In the actual process, the display device may include, in addition to the sensing unit 1320: a display panel, a scan driver, a light emitting driver, a data driver, a timing controller, and the like. The display panel can display images, such as still images or video images. As shown in fig. 14, the display panel may include a plurality of scan lines SL1 to SLn, a plurality of data lines DL1 to DLm, and a plurality of emission control lines EL1 to ELn. The display panel may further include a plurality of pixels P connected to the plurality of scan lines SL1 to SLn, the plurality of light emission control lines EL1 to ELn, and the plurality of data lines DL1 to DLm. The number of the plurality of scan lines SL1 to SLn and the number of the plurality of emission control lines EL1 to ELn may each be n. The number of the plurality of data lines DL1 to DLm may be m, where n and m are natural numbers (e.g., greater than zero); the number of the plurality of pixels P may be n × m. The display panel may receive the first driving power Vdd and the second driving power Vss from the outside (e.g., power terminals). The timing controller may receive an input control signal and an input image signal from an image source such as an external graphic device. The timing controller generates image data RGB corresponding to an operating condition of the display panel based on the input image signal and supplies the image data RGB to the data driver. The timing controller generates a first driving control signal SCS for controlling a driving timing of the scan driver, a second driving control signal ECS for controlling a driving timing of the light emitting driver, and a third driving control signal DCS for controlling a driving timing of the data driver based on the input control signals, and may supply the first driving control signal SCS, the second driving control signal ECS, and the third driving control signal DCS to the scan driver, the light emitting driver, and the data driver, respectively.

The first driving control signal SCS may include a scan start signal (or a scan start pulse) and a clock signal. The scan start signal may control a first timing of the scan signal. The clock signal is used to shift the scan start pulse. The second driving control signal ECS may include a light emission control start signal (or a light emission control start pulse) and a clock signal. The light-emitting control start signal may control a first timing of the light-emitting control signal. The clock signal is used to shift the light emission control start pulse. The third driving control signal DCS may include a source start pulse and a clock signal. The source start pulse may control a sampling start time point of data. The clock signal is used to control the sampling operation.

The scan driver may receive the first driving control signal SCS from the timing controller. The scan driver may supply scan signals to the plurality of scan lines SL1 to SLn in response to the first driving control signal SCS.

The light emitting driver may receive the second driving control signal ECS from the timing controller. The light emission driver supplies a light emission control signal to the plurality of light emission control lines EL1 to ELn in response to the second drive control signal ECS. The light emission control signal may control light emission time of the plurality of pixels P. The data driver may receive the third driving control signal DCS from the timing controller. The data driver may supply data signals (data voltages) in an analog format to the plurality of data lines DL1 to DLm in response to the third driving control signal DCS. The data signals supplied to the plurality of data lines DL1 to DLm are supplied to the pixels P selected by the scan signals.

During fingerprint Sensing, a current generated by the photo Sensing device 120 in the pixel P circuit may be supplied to a gate of the driving transistor in the pixel P circuit, so that a magnitude of the current on the Sensing line Sensing changes, thereby enabling the display device to sense a voltage or a current on any node of the Sensing line Sensing through the Sensing unit to sense a touch or a fingerprint of a user.

To sum up, according to the display device of the embodiment of the present application, with the display panel in the above embodiment, the sensing switch module is controlled by the second control signal terminal to provide the first initialization voltage signal sent by the sensing line to the photo sensing device, and the photo sensing device is controlled by the third control signal terminal to transmit the photo-generated current signal generated according to the incident light to the control terminal of the driving module, so that the turn-on degree of the driving module is related to the intensity of light, thereby realizing the combination of the photo sensing unit and the external compensation driving circuit, reducing the devices required by the external compensation driving circuit, reducing the space occupied by the external compensation driving circuit, and saving more space for the photo sensing unit.

In addition, the display device in the embodiment of the application provides the initialization signal for the photoelectric sensing device through the optical line, and the initialization signal is not required to be provided by an additional signal line, so that the space occupied by the signal line is saved, and the cost is reduced.

Those of skill would further appreciate that the various illustrative components and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied in hardware, a software module executed by a processor, or a combination of the two. A software module may reside in Random Access Memory (RAM), memory, Read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

The above-mentioned embodiments, objects, technical solutions and advantages of the present application are described in further detail, it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present application, and are not intended to limit the scope of the present application, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present application should be included in the scope of the present application.