CN112652270B

CN112652270B - Pixel circuit, display panel and display device

Info

Publication number: CN112652270B
Application number: CN202011578560.7A
Authority: CN
Inventors: 熊志勇; 丁陈敏; 吴海妍
Original assignee: Wuhan Tianma Microelectronics Co Ltd
Current assignee: Wuhan Tianma Microelectronics Co Ltd
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2021-11-23
Anticipated expiration: 2040-12-28
Also published as: CN112652270A

Abstract

The application discloses a pixel circuit, a display panel and a display device. The pixel circuit includes: a light emitting element; the driving module and the light-emitting element are connected in series between a first power supply end and a second power supply end, the driving module is used for generating driving current to drive the light-emitting element to emit light, and the driving module comprises a driving transistor; the second end of the variable resistor is electrically connected with the grid electrode of the driving transistor, the first end of the variable resistor is electrically connected with the second electrode of the at least one switching transistor, and the resistance value of the variable resistor can be increased along with the increase of the temperature and reduced along with the decrease of the temperature. According to the embodiment of the application, the influence of the drain current of the transistor on the display effect can be reduced.

Description

Pixel circuit, display panel and display device

Technical Field

The application relates to the technical field of display, in particular to a pixel circuit, a display panel and a display device.

Background

Organic Light Emitting Diodes (OLEDs) are one of the hot spots in the research field of Display devices, and compared with Liquid Crystal Displays (LCDs), OLED Display panels have the advantages of low energy consumption, low production cost, self-luminescence, wide viewing angle, and fast response speed, and at present, OLED Display panels have begun to replace the conventional LCD Display panels in the Display fields of mobile phones, PDAs, digital cameras, and the like.

In the OLED display panel, the OLED needs to be driven by a pixel circuit, the pixel circuit is mainly composed of a plurality of transistors, however, the transistors have a leakage current phenomenon, which affects the display effect of the display panel.

Disclosure of Invention

The application provides a pixel circuit, a display panel and a display device, which can reduce the influence of the leakage current of a transistor on the display effect.

In a first aspect, an embodiment of the present application provides a pixel circuit, which includes: a light emitting element; the driving module and the light-emitting element are connected in series between a first power supply end and a second power supply end, the driving module is used for generating driving current to drive the light-emitting element to emit light, and the driving module comprises a driving transistor; at least one switching transistor; the second end of the variable resistor is electrically connected with the grid electrode of the driving transistor, the first end of the variable resistor is electrically connected with the second electrode of the at least one switching transistor, and the resistance value of the variable resistor can be increased along with the increase of the temperature and reduced along with the decrease of the temperature.

In a second aspect, based on the same inventive concept, embodiments of the present application provide a display panel including the pixel driving circuit as in the first aspect.

In a third aspect, based on the same inventive concept, embodiments of the present application provide a display device including the display panel according to the foregoing second aspect of the present application.

According to the pixel circuit, the display panel and the display device provided by the embodiment of the application, the pixel circuit, the display panel and the display device comprise a light emitting element, a driving module and a variable resistor, wherein a first end of the variable resistor is electrically connected with a second pole of at least one switching element, a second end of the variable resistor is electrically connected with a grid electrode of a driving transistor in the driving module, and the resistance value of the variable resistor can be increased along with the increase of temperature and reduced along with the reduction of temperature; on the other hand, at low temperature, the switching transistor electrically connected to the gate of the driving transistor is kept in an off state relatively well, that is, the switching transistor electrically connected to the gate of the driving transistor is not easy to generate leakage current, so that the gate potential of the driving transistor does not need to be balanced by a resistor, and the resistance value of the variable resistor can be reduced.

Drawings

Other features, objects, and advantages of the present application will become apparent from the following detailed description of non-limiting embodiments thereof, when read in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof, and which are not to scale.

Fig. 1 is a schematic structural diagram of a pixel circuit provided in the related art;

fig. 2 shows a graphical representation of the current of the switching transistor at different temperatures;

fig. 3 is a schematic structural diagram of a pixel circuit according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a pixel circuit according to another embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a pixel circuit according to yet another embodiment of the present application;

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

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

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

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

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

fig. 11 is a schematic structural diagram of a pixel circuit according to yet another embodiment of the present application;

fig. 12 is a schematic diagram illustrating a top view structure of a display panel according to an embodiment of the present application;

fig. 13 is a schematic cross-sectional view illustrating a display panel according to an embodiment of the present disclosure;

fig. 14 is a schematic structural diagram of a display device according to an embodiment of the present application.

Detailed Description

Features and exemplary embodiments of various aspects of the present application will be described in detail below, and in order to make objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. It will be apparent to one skilled in the art that the present application may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present application by illustrating examples thereof.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

It will be understood that when a layer, region or layer is referred to as being "on" or "over" another layer, region or layer in describing the structure of the component, it can be directly on the other layer, region or layer or intervening layers or regions may also be present. Also, if the component is turned over, one layer or region may be "under" or "beneath" another layer or region.

In the OLED display panel, the OLED needs to be driven by a pixel circuit. Fig. 1 shows a schematic structural diagram of a pixel circuit provided in the related art. As shown in fig. 1, the pixel circuit includes a driving transistor DT 'and switching transistors M1', M2 'electrically connected to the gate of the driving transistor DT'. The usage environment of the OLED display panel may have a high temperature or a low temperature, for example, the usage environment is summer, winter, tropical, cold zone, etc. The switching transistor has a certain temperature sensitivity, and its characteristics are shifted in a high temperature or low temperature environment compared to a normal temperature environment. The leakage current of the switching transistors M1 'and M2' affects the potential of the gate of the driving transistor DT ', causing the current of the driving transistor DT' to vary, and thus causing the luminance of the light emitting element to be unstable with temperature variation.

On the basis of the pixel circuit shown in fig. 1, the inventors of the present application tested the current condition of the switching transistor M1' at different temperatures. Fig. 2 shows a diagram of the current of a switching transistor at different temperatures. Fig. 2 shows the change of the current Id of the switching transistor M1' at room temperature, 40 ℃, 60 ℃, 80 ℃ and 100 ℃. Taking the switching transistor M1 ' as an example of a P-type transistor, in the case that the gate-source voltage difference Vgs of the switching transistor M1 ' is greater than or equal to the threshold voltage Vth thereof, the switching transistor M1 ' should be in an off state, and the current Id of the switching transistor M1 ' is greater with the increase of temperature, that is, the leakage current of the switching transistor M1 ' is increased by several orders of magnitude with the increase of temperature. It can be seen that the leakage problem of the switching transistor M1' is exacerbated in high temperature environments.

In addition, the inventors of the present application found that the leakage current of 1pA after one frame time causes the potential of the gate electrode of the driving transistor DT' to rise by 100mV, about 20 gray levels; the leakage current of 0.1pA for one frame period causes the potential of the gate electrode of the driving transistor DT' to rise by 10mV, about 2 gray levels. It is obvious that if the potential of the gate of the driving transistor DT' is unstable, the stability of the light emitting luminance of the light emitting element is seriously affected.

In view of the above technical problems, the present application provides a pixel circuit, a display panel and a display device, and the pixel circuit, the display panel and the display device provided in the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

Fig. 3 shows a schematic structural diagram of a pixel circuit according to an embodiment of the present application. As shown in fig. 3, the pixel circuit 10 provided in the embodiment of the present application includes a light emitting device D, a driving module 11, at least one switching transistor K, and a variable resistor R. The driving module 11 and the light emitting device D are connected in series between the first power supply electrode PVDD and the second power supply electrode PVEE, and the driving module 11 is configured to generate a driving current to drive the light emitting device D to emit light. The driving module 11 includes a driving transistor DT. The first end of the variable resistor R is electrically connected to the second pole of the switching transistor K, the second end of the variable resistor R is electrically connected to the gate of the driving transistor DT, and the resistance of the variable resistor R may increase with increasing temperature and decrease with decreasing temperature.

According to the pixel circuit provided by the embodiment of the application, on one hand, even if the switching transistor K electrically connected with the gate of the driving transistor DT has leakage current at high temperature, the resistance value of the variable resistor R is increased, so that the influence of the leakage current of the switching transistor K on the gate potential of the driving transistor DT can be prevented, the stability of the gate potential of the driving transistor DT at high temperature can be improved, and the stability of the light-emitting brightness of the light-emitting element D can be improved; on the other hand, at low temperature, the switching transistor K electrically connected to the gate of the driving transistor DT is kept in a relatively good off state, that is, the switching transistor K electrically connected to the gate of the driving transistor DT is not likely to generate leakage current, and it is no longer necessary to balance the gate potential of the driving transistor DT with a resistor, and the resistance of the variable resistor R may be reduced. In addition, at low temperature, the power consumption during the operation of the pixel circuit can be reduced by reducing the resistance value of the variable resistor R.

For example, the resistance of the variable resistor R may be changed after the temperature variation exceeds a certain threshold. For example, the resistance value of the variable resistor R increases by a certain value when the temperature increases by 2 ℃, and decreases by a certain value when the temperature decreases by 2 ℃. In addition, the resistance value of the variable resistor R can also change in real time along with the temperature change, that is, the resistance value of the variable resistor R changes as long as the temperature changes. The variation of the resistance value of the variable resistor R with temperature may be set according to actual conditions, which is not limited in this application.

Illustratively, one switching transistor K is illustrated in fig. 3, which is not intended to limit the present application. In addition, the connection relationship between the first electrode and the gate electrode of the switching transistor K is not illustrated in fig. 3, and actually, the first electrode and the gate electrode of the switching transistor K are not floating, the first electrode of the switching transistor K may be electrically connected to the reference signal terminal or the second electrode of the driving transistor DT, and the gate electrode of the switching transistor K may be electrically connected to the scan signal terminal, which is not limited in this application.

In some alternative embodiments, the variable resistor R may be a temperature sensitive resistor. The resistance value of the temperature-sensitive resistor is increased along with the increase of the temperature and is reduced along with the decrease of the temperature, the temperature-sensitive resistor is simple in structure and is easy to form in the manufacturing process, and therefore the potential of the grid electrode of the driving transistor can be prevented from being influenced by the change of the temperature simply and conveniently through the temperature-sensitive resistor.

In some optional embodiments, as shown in any one of fig. 4 to 7, the pixel circuit 10 provided in this embodiment of the present application may further include a data writing module 12, a first initialization module 13, a threshold compensation module 14, a light emitting control module 15, and a storage module 16.

The data writing module 12 is electrically connected to a first electrode of the driving transistor DT, and is configured to write a data signal to a gate electrode of the driving transistor DT. The first initialization module 13 is electrically connected to the reference signal terminal VREF, the gate of the driving transistor DT, and the memory module 16, and the first initialization module 13 is configured to initialize the gate of the driving transistor DT. The threshold compensation module 14 is electrically connected to the gate electrode of the driving transistor DT and the second electrode of the driving transistor DT, and the threshold compensation module 14 is used to detect and self-compensate for a threshold voltage deviation of the driving transistor DT. The light emission control module 15 is connected in series between the first power source terminal PVDD and the light emitting element D, and the light emission control module 15 is configured to control transmission of the driving current generated by the driving transistor DT to the light emitting element D. The memory module 16 is disposed between the first power source PVDD and the gate of the driving transistor DT, and the memory module 16 is configured to maintain a potential of the gate of the driving transistor DT.

The first initialization module 13 and the threshold compensation module 14 may both include a switching transistor K, and since the first initialization module 13 and the threshold compensation module 14 are both electrically connected to the gate of the driving transistor DT, if there is a leakage current in the switching transistors of the first initialization module 13 and the threshold compensation module 14 under a high temperature environment, the potential of the gate of the driving transistor DT is affected. Therefore, the second pole of the switching transistor K of at least one of the first initialization module 13 and the threshold compensation module 14 is electrically connected to the first end of the variable resistor R. The resistance of the variable resistor R may increase with increasing temperature, so as to prevent the leakage current of the switching transistor in the first initialization module 13 and/or the threshold compensation module 14 from affecting the potential of the gate of the driving transistor DT at high temperature.

For example, fig. 4 shows that the variable resistor R is connected in series between the first initialization module 13 and the gate of the driving transistor DT, fig. 5 shows that the variable resistor R is connected in series between the threshold compensation module 14 and the gate of the driving transistor DT, and fig. 6 and 7 show that the variable resistor R is connected in series between the first initialization module 13 and the threshold compensation module 14 and the gate of the driving transistor DT. For example, as shown in fig. 6, the number of the variable resistors R may be one, the second terminal of the variable resistor R is connected to the gate of the driving transistor DT, and the first terminal of the variable resistor R is connected to the second terminals of the switching transistors K in the first initialization module 13 and the threshold compensation module 14. For example, as shown in fig. 7, the number of the variable resistors R may be two, namely, a first variable resistor R1 and a second variable resistor R2, a first end of the first variable resistor R1 is electrically connected to the second pole of the switching transistor K in the first initialization module 13, and a second end of the first variable resistor R1 is connected to the gate of the driving transistor DT; a first terminal of the second variable resistor R2 is electrically connected to the second pole of the switching transistor K in the threshold compensation module 14, and a second terminal of the second variable resistor R2 is connected to the gate of the driving transistor DT.

In some optional embodiments, as shown in any one of fig. 4 to 7, the pixel circuit provided in the embodiment of the present application may further include a second initialization module 17, where the second initialization module 17 is electrically connected to an anode of the light emitting element D, and is used to initialize the light emitting element D, so as to prevent the display panel from generating image sticking.

In some optional embodiments, specific structures of the data writing module 12, the first initialization module 13, the threshold compensation module 14, the light-emitting control module 15, the storage module 16, and the second initialization module 17 may be as shown in fig. 8 to 11.

Specifically, the data writing module 12 includes a first transistor M1, the first initialization module 13 includes a second transistor M2, the threshold compensation module 14 includes a third transistor M3, the light emitting control module 15 includes a fourth transistor M4 and a fifth transistor M5, and the storage module 16 includes a capacitor Cst. The second initialization module 17 includes a sixth transistor M6. The second transistor M2 and the third transistor M3 are both the above-described switching transistor K.

The gate of the second transistor M2 is electrically connected to the first SCAN signal terminal SCAN1, the first pole of the second transistor M2 is electrically connected to the reference signal terminal VREF, and the second pole of the second transistor M2 is electrically connected to the gate of the driving transistor DT. The gate of the first transistor M1 is electrically connected to the second SCAN signal terminal SCAN2, the first pole of the first transistor M1 is electrically connected to the data signal terminal VDATA, and the second pole of the first transistor M1 is electrically connected to the first pole of the driving transistor DT. A gate electrode of the third transistor M3 is electrically connected to the second SCAN signal terminal SCAN2, a first electrode of the third transistor M3 is electrically connected to the second electrode of the driving transistor DT, and a second electrode of the third transistor M3 is electrically connected to the gate electrode of the driving transistor DT. A gate of the fourth transistor M4 is electrically connected to the emission control signal terminal EM, a first pole of the fourth transistor M4 is electrically connected to the first power source terminal PVDD, and a second pole of the fourth transistor M4 is electrically connected to the first pole of the driving transistor DT. The gate of the fifth transistor M5 is electrically connected to the emission control signal terminal EM, the first pole of the fifth transistor M5 is electrically connected to the second pole of the driving transistor DT, and the second pole of the fifth transistor M5 is electrically connected to the first pole of the light emitting element D. A first electrode of the capacitor Cst is electrically connected to the first power source terminal PVDD, and a second electrode of the capacitor Cst is electrically connected to the gate electrode of the driving transistor DT. A gate of the sixth transistor M6 is electrically connected to the first SCAN signal terminal SCAN1, a first pole of the sixth transistor M6 is electrically connected to the reference signal terminal VREF, and a second pole of the sixth transistor M6 is electrically connected to the first pole of the light emitting element D. The second pole of the light emitting element D is electrically connected to the second power source terminal PVEE, and the first pole of the light emitting element D may be an anode and the second pole of the light emitting element D may be a cathode.

The specific components and connection modes included in the above modules are only an illustration, and it is within the scope of the present application as long as a variable resistor is connected in series between the transistor electrically connected to the gate of the driving transistor DT and the gate of the driving transistor DT, and the present application does not limit the specific structure of the pixel circuit.

In the above example, the second pole of the second transistor M2 and the second pole of the third transistor M3 are both electrically connected to the gate of the driving transistor DT, and the leakage current of the second transistor M2 and the third transistor M3 may affect the potential of the gate of the driving transistor DT in a high temperature environment. Therefore, a variable resistor R is connected in series between at least one of the second pole of the second transistor M2 and the second pole of the third transistor M3 and the gate of the driving transistor DT. The resistance of the variable resistor R may increase with increasing temperature, so as to prevent the leakage current of the second transistor M2 and/or the third transistor M3 from affecting the potential of the gate of the driving transistor DT at high temperature.

Illustratively, the number of the variable resistors R may be one. As shown in fig. 8, the variable resistor R may be connected in series between the second pole of the second transistor M2 and the gate of the driving transistor DT. Specifically, a first terminal of the variable resistor R is electrically connected to the second pole of the second transistor M2, and a second terminal of the variable resistor R is electrically connected to the gate of the driving transistor DT. As shown in fig. 9, the variable resistor R may be connected in series between the second pole of the third transistor M3 and the gate of the driving transistor DT. Specifically, a first terminal of the variable resistor R is electrically connected to the second terminal of the third transistor M3, and a second terminal of the variable resistor R is electrically connected to the gate of the driving transistor DT. As shown in fig. 10, the variable resistor R may be connected in series between the second pole of the second transistor M2 and the second pole of the third transistor M3 and the gate of the driving transistor DT. Specifically, a first end of the variable resistor R is electrically connected to the second pole of the second transistor M2 and the second pole of the third transistor M3, and a second end of the variable resistor R is electrically connected to the gate of the driving transistor DT. It can be understood that, in the case that the first terminal of the variable resistor R is electrically connected to both the second pole of the second transistor M2 and the second pole of the third transistor M3, only one variable resistor R can be used, and the leakage current of the second transistor M2 and the third transistor M3 at high temperature can be prevented from affecting the potential of the gate of the driving transistor DT.

For example, in order to simultaneously prevent the leakage current of the second transistor M2 and the third transistor M3 from affecting the potential of the gate of the driving transistor DT at a high temperature, the number of the variable resistors R may be two. Specifically, as shown in fig. 11, the variable resistor R may include a first variable resistor R1 and a second variable resistor R2, a first terminal of the first variable resistor R1 is electrically connected to the second pole of the second transistor M2, a second terminal of the first variable resistor R1 is electrically connected to the gate of the driving transistor DT, a first terminal of the second variable resistor R2 is electrically connected to the second pole of the third transistor M3, and a second terminal of the second variable resistor R2 is electrically connected to the gate of the driving transistor DT.

The application also provides a display panel. Fig. 12 shows a schematic structural diagram of a display panel provided in an embodiment of the present application. As shown in fig. 12, the display panel 100 provided in the embodiment of the present application may include the pixel circuit 10 described in any of the embodiments. The display panel shown in fig. 12 may be an Organic Light-Emitting Diode (OLED) display panel.

It should be understood by those skilled in the art that in other implementations of the present application, the display panel may also be a Micro light emitting diode (Micro LED) display panel, a quantum dot display panel, or the like.

For example, the plurality of pixel circuits 10 may be distributed in the display area AA of the display panel 100 in an array. The display panel 100 may further include a non-display area NA disposed at least partially around the display area AA.

The display panel 100 provided in the embodiment of the present application has the beneficial effects of the pixel circuit 10 provided in the embodiment of the present application, and specific reference may be made to the specific description of the pixel driving circuit in each of the above embodiments, which is not repeated herein.

In some alternative embodiments, please continue to refer to fig. 12, the display panel 100 may further include a temperature detection module 20 and a control module 30. The temperature detection module 20 is configured to detect a temperature of the display panel 100 and send the detected temperature to the control module 30. The control module 30 is configured to control the resistance of the variable resistor R according to the temperature detected by the temperature detection module 20.

For example, when the temperature detection module 20 detects a temperature increase of the display panel, or detects that a value of the temperature increase of the display panel is greater than a certain threshold, the control module 30 increases the resistance value of the variable resistor R. When the temperature detection module 20 detects that the temperature of the display panel decreases, or detects that the value of the temperature decrease of the display panel is greater than a certain threshold, the control module 30 decreases the resistance of the variable resistor R. For example, the temperature detection module 20 may specifically include a temperature sensor, which may be a thermocouple type or a thermal resistor type, and is not limited in this application.

For example, the temperature detection module 20 and the control module 30 may be disposed in the non-display area NA of the display panel 100. The temperature detecting module 20 may also be bound to a non-light-emitting surface of the display panel 100, which is not limited in this application. The control module 30 may be integrated on a driving chip of the display panel 100, which is not limited in this application.

In some alternative embodiments, as shown in fig. 13, the display panel 100 may include a substrate 40 and a driving device layer 50 on one side of the substrate 40. The light emitting element D may be located on a side of the driving device layer 50 facing away from the substrate 40. The driving transistor DT may be disposed within the driving device layer 50.

The driving transistor DT includes an active layer b, a gate electrode g, a source electrode s, and a drain electrode d. The gate g is insulated from the active layer b, and the source s and the drain d may be connected to the active layer b through a via hole. Fig. 13 exemplarily shows that the driving transistor DT has a top-gate structure, and the driving transistor DT may also have a bottom-gate structure, which is not limited in this application. In addition, fig. 13 shows only the driving transistor DT in the pixel circuit, and the structure of other transistors may be the same as the driving transistor DT.

Fig. 13 exemplarily shows that the variable resistor R is located between the driving device layer 50 and the light emitting element D. Specifically, the light emitting element D may include a first electrode D1, a light emitting layer D2, and a second electrode D3 that are stacked, with the variable resistor R between the driving device layer 50 and the first electrode D1.

The variable resistor R may be disposed in the driving device layer 50, and specifically, the variable resistor R may be disposed in the same layer as any one of the active layer b, the gate g, the source s, and the drain d of the driving transistor DT, which is not limited thereto.

Illustratively, the capacitor Cst includes a first plate C1 and a second plate C2, the first plate C1 may be disposed at the same level as the gate g of the driving transistor DT, and the second plate C2 may be disposed at the same level as the active layer b of the driving transistor DT. Fig. 13 is merely an example, and the present application is not limited thereto.

Illustratively, the display panel 100 further includes a pixel defining layer 60, and the pixel defining layer 60 is located on a side of the driving device layer 50 opposite to the substrate 40. The pixel defining layer 60 includes an opening K for defining a light emitting layer D2 of the light emitting element D.

The application also provides a display device which comprises the display panel provided by the application. Referring to fig. 14, fig. 14 is a schematic structural diagram of a display device according to an embodiment of the present application. Fig. 14 provides a display device 1000 including the display panel 100 according to any of the above embodiments of the present application. The display device 1000 is described in the embodiment of fig. 14 by taking a mobile phone as an example, but it should be understood that the display device provided in the embodiment of the present application may be other display devices having a display function, such as a wearable product, a computer, a television, and a vehicle-mounted display device, and the present application is not limited thereto. The display device provided in the embodiment of the present application has the beneficial effects of the display panel provided in the embodiment of the present application, and specific reference may be specifically made to the specific description of the display panel in each of the above embodiments, which is not repeated herein.

In accordance with the embodiments of the present application as described above, these embodiments are not exhaustive and do not limit the application to the specific embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the application and its practical application, to thereby enable others skilled in the art to best utilize the application and its various modifications as are suited to the particular use contemplated. The application is limited only by the claims and their full scope and equivalents.

Claims

1. A pixel circuit, comprising:

a light emitting element;

the driving module and the light-emitting element are connected in series between a first power supply end and a second power supply end, the driving module is used for generating driving current to drive the light-emitting element to emit light, and the driving module comprises a driving transistor;

at least one switching transistor;

and the second end of the variable resistor is electrically connected with the grid electrode of the driving transistor, the first end of the variable resistor is electrically connected with the second pole of at least one switching transistor, and the resistance value of the variable resistor can increase along with the increase of the temperature and decrease along with the decrease of the temperature.

2. The pixel circuit according to claim 1, wherein the variable resistor comprises a temperature sensitive resistor.

3. The pixel circuit according to claim 1, further comprising a data writing module, a first initialization module, a threshold compensation module, a light emission control module, and a storage module;

the data writing module is electrically connected with the driving transistor and used for writing data signals into the grid electrode of the driving transistor;

the first initialization module is electrically connected with a reference signal end, the grid electrode of the driving transistor and the storage module, and is used for initializing the grid electrode of the driving transistor;

the threshold compensation module is electrically connected with the grid electrode of the driving transistor and is used for detecting and self-compensating threshold voltage deviation of the driving transistor;

the light-emitting control module is connected in series between the first power end and the light-emitting element, and is used for transmitting the driving current generated by the driving transistor to the light-emitting element;

the storage module is electrically connected with the grid electrode of the driving transistor and is used for maintaining the potential of the grid electrode of the driving transistor;

wherein the first initialization module and the threshold compensation module each include the switching transistor, and a second pole of the switching transistor of at least one of the first initialization module and the threshold compensation module is electrically connected to a first end of the variable resistor.

4. The pixel circuit according to claim 3, wherein the data writing module comprises a first transistor, the first initialization module comprises a second transistor, the threshold compensation module comprises a third transistor, the light emission control module comprises a fourth transistor and a fifth transistor, and the storage module comprises a capacitor;

the grid electrode of the second transistor is electrically connected with a first scanning signal end, the first electrode of the second transistor is electrically connected with a reference signal end, and the second electrode of the second transistor is electrically connected with the grid electrode of the driving transistor;

a gate of the first transistor is electrically connected to a second scan signal terminal, a first electrode of the first transistor is electrically connected to a data signal terminal, and a second electrode of the first transistor is electrically connected to a first electrode of the driving transistor;

a gate electrode of the third transistor is electrically connected to the second scan signal terminal, a first electrode of the third transistor is electrically connected to a second electrode of the driving transistor, and a second electrode of the third transistor is electrically connected to a gate electrode of the driving transistor;

a gate of the fourth transistor is electrically connected to a light-emitting control signal terminal, a first electrode of the fourth transistor is electrically connected to the first power terminal, and a second electrode of the fourth transistor is electrically connected to the first electrode of the driving transistor;

a gate of the fifth transistor is electrically connected to the light emission control signal terminal, a first electrode of the fifth transistor is electrically connected to the second electrode of the driving transistor, and a second electrode of the fifth transistor is electrically connected to the first electrode of the light emitting element;

a first pole of the capacitor is electrically connected with the first power supply end, and a second pole of the capacitor is electrically connected with the grid electrode of the driving transistor;

wherein the second transistor and the third transistor are the switching transistors, and a second pole of at least one of a second pole of the second transistor and a second pole of the third transistor is electrically connected to a first end of the variable resistor.

5. The pixel circuit according to claim 4, wherein a first terminal of the variable resistor is electrically connected to the second pole of the second transistor, and a second terminal of the variable resistor is electrically connected to the gate of the driving transistor; and/or the presence of a gas in the gas,

a first terminal of the variable resistor is electrically connected to the second pole of the third transistor, and a second terminal of the variable resistor is electrically connected to the gate of the driving transistor.

6. The pixel circuit according to claim 4, wherein a first terminal of the variable resistor is electrically connected to both the second pole of the second transistor and the second pole of the third transistor, and a second terminal of the variable resistor is electrically connected to the gate of the driving transistor;

alternatively, the variable resistor includes a first variable resistor and a second variable resistor, a first end of the first variable resistor is electrically connected to the second pole of the second transistor, a second end of the first variable resistor is electrically connected to the gate of the driving transistor, a first end of the second variable resistor is electrically connected to the second pole of the third transistor, and a second end of the second variable resistor is electrically connected to the gate of the driving transistor.

7. A display panel comprising the pixel circuit according to any one of claims 1 to 6.

8. The display panel according to claim 7, wherein the display panel further comprises a temperature detection module and a control module;

the temperature detection module is used for detecting the temperature of the display panel and sending the detected temperature to the control module;

the control module is used for controlling the resistance value of the variable resistor according to the temperature detected by the temperature detection module.

9. The display panel according to claim 7, wherein the display panel comprises a substrate and a driving device layer on one side of the substrate;

the light-emitting element is positioned on one side, opposite to the substrate, of the driving device layer;

the driving transistor is arranged on the driving device layer and comprises an active layer, a grid electrode, a source electrode and a drain electrode;

the variable resistor is located between the driving device layer and the light emitting element, or is disposed on the same layer as any one of an active layer, a gate electrode, a source electrode, and a drain electrode of the driving transistor.

10. A display device characterized by comprising the display panel according to any one of claims 7 to 9.