Pixel circuit and display device

Abstract

The invention provides a pixel circuit and a display device, and the pixel circuit comprises a driving module, a light-emitting module, a first reset module, and a current compensation module. The driving module is used for driving the light-emitting module to emit light according to the control end potential; the output end of the first reset module and the output end of the current compensation module are electrically connected with the control end of the driving module, so that the current compensation module compensates the potential of the control end of the driving module pulled down by the first reset module under the condition that the control end of the driving module is in a potential holding stage. According to the scheme, the display quality can be effectively improved.

Description

Technical Field

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

[0002] Display panels made with low temperature polycrystalline silicon (LTPS) technology have gradually become popular products in the market due to their advantages of fast response, high resolution, bright colors, etc. However, since silicon thin film transistors, such as low temperature polycrystalline silicon thin film transistors (LTPS TFTs), have a large photocurrent, they will affect the display quality of the display panel. Summary of the invention

[0003] The present application provides a pixel circuit and a display device to solve the problem in the related art that the photocurrent generated by the pixel circuit is large, which affects the display quality of the display panel.

[0004] In a first aspect, the present application provides a pixel circuit, which includes a driving module, a light-emitting module, a first reset module and a current compensation module; the driving module is used to drive the light-emitting module to emit light according to the potential of its control terminal; the output end of the first reset module and the output end of the current compensation module are both electrically connected to the control end of the driving module, so that the current compensation module compensates for the control end potential of the driving module pulled down by the first reset module when the control end of the driving module is in a potential holding stage.

[0005] In one embodiment, the potential holding stage includes a light emitting stage, the driving module is used to drive the light emitting module to emit light during the light emitting stage, and the current compensation module is used to perform potential compensation on the control end of the driving module during the light emitting stage.

[0006] Preferably, the input end of the current compensation module is connected to the control end of the current compensation module to put the current compensation module in a cut-off state; or, the control end of the current compensation module is used to access a cut-off signal to put the current compensation module in a cut-off state.

[0007] Preferably, the input end of the current compensation module is electrically connected to the data signal line to receive the data voltage during the data writing phase.

[0008] Preferably, the current compensation module includes a current compensation transistor, the second electrode of the current compensation transistor constitutes the input end of the current compensation module, the first electrode of the current compensation transistor constitutes the output end of the current compensation module, and the control electrode of the current compensation transistor constitutes the control end of the current compensation module.

[0009] In one embodiment, the output end of the first reset module, the output end of the current compensation module and the control end of the driving module are all connected to the first node, the input end of the first reset module is connected to the second node, and the input end of the current compensation module constitutes a third node; in the potential holding stage, the potential of the third node is higher than the potential of the first node, and the potential of the first node is higher than the potential of the second node.

[0010] Preferably, in the potential holding stage, the potential difference between the third node and the first node is equal to the potential difference between the first node and the second node.

[0011] Preferably, the input end of the first reset module is connected to the reset signal line, the control end of the first reset module is connected to the first scanning signal line, and the first reset module is also used to transmit the reset voltage on the reset signal line to the control end of the driving module during the reset phase.

[0012] In one embodiment, the first reset module includes a first reset transistor, the second electrode of the first reset transistor is connected to the first node, the first electrode of the first reset transistor is connected to the second node and connected to the reset signal line, and the control end of the first reset transistor is connected to the first scanning signal line; or, the first reset module includes a first sub-reset transistor and a second sub-reset transistor, the second electrode of the first sub-reset transistor is connected to the first node, the first electrode of the first sub-reset transistor is electrically connected to the second electrode of the second sub-reset transistor, the first electrode of the second sub-reset transistor is connected to the second node and connected to the reset signal line, and the control electrode of the first sub-reset transistor and the control electrode of the second sub-reset transistor are both connected to the first scanning signal line.

[0013] In one embodiment, the pixel circuit further includes a second reset module, the second reset module is connected between the reset signal line and the first end of the light emitting module, and a control end of the second reset module is electrically connected to the first scanning signal line.

[0014] Preferably, the pixel circuit also includes a data writing module and a threshold compensation module, the data writing module is connected between the data signal line and the second end of the driving module, the threshold compensation module is connected between the first end of the driving module and the control end of the driving module, the control end of the data writing module and the control end of the threshold compensation module are both connected to the second scanning signal line, and the data writing module is used to transmit the data voltage on the data signal line to the control end of the driving module via the threshold compensation module during the data writing stage.

[0015] Preferably, the pixel circuit further comprises a storage module, the storage module is connected between the first power line and the control end of the driving module, and the storage module is used to store the data voltage written by the control end of the driving module.

[0016] Preferably, the pixel circuit also includes a first light-emitting control module and a second light-emitting control module, the first light-emitting control module is connected between the first power line and the second end of the driving module, the second light-emitting control module is connected between the first end of the driving module and the first end of the light-emitting module, the control end of the first light-emitting control module and the control end of the second light-emitting control module are both connected to the light-emitting control signal line, the first light-emitting control module is used to transmit the first power supply voltage on the first power line to the second end of the driving module during the light-emitting stage, and the second light-emitting control module is used to electrically connect the first end of the driving module and the first end of the light-emitting module during the light-emitting stage.

[0017] Preferably, the second end of the light emitting module is connected to the second power line.

[0018] In one embodiment, the second reset module includes a second reset transistor, a second electrode of the second reset transistor is connected to the first end of the light emitting module, a first electrode of the second reset transistor is connected to the reset signal line, and a control electrode of the second reset transistor is connected to the first scanning signal line.

[0019] Preferably, the data writing module includes a data writing transistor, a first electrode of the data writing transistor is connected to the second end of the driving module, a second electrode of the data writing transistor is connected to the data signal line, and a control electrode of the data writing transistor is connected to the second scanning signal line.

[0020] Preferably, the threshold compensation module includes a threshold compensation transistor, a first electrode of the threshold compensation transistor is connected to the control end of the driving module, a second electrode of the threshold compensation transistor is connected to the first end of the driving module, and a control electrode of the threshold compensation transistor is connected to the second scan signal line; or, the threshold compensation module includes a first sub-threshold compensation transistor and a second sub-threshold compensation transistor, a first electrode of the first sub-threshold compensation transistor is connected to the control end of the driving module, a second electrode of the first sub-threshold compensation transistor is connected to the first electrode of the second sub-threshold compensation transistor, a second electrode of the second sub-threshold compensation transistor is connected to the first end of the driving module, and a control electrode of the first sub-threshold compensation transistor and a control electrode of the second sub-threshold compensation transistor are both connected to the second scan signal line.

[0021] Preferably, the storage module includes a storage capacitor, a first electrode of the storage capacitor is connected to the first power line, and a second electrode of the storage capacitor is connected to the control end of the driving module.

[0022] Preferably, the first light-emitting control module includes a first light-emitting control transistor, the second light-emitting control module includes a second light-emitting control transistor, the first electrode of the first light-emitting control transistor is connected to the second end of the driving module, the second electrode of the first light-emitting control transistor is connected to the first power line, the first electrode of the second light-emitting control transistor is connected to the first end of the light-emitting module, the second electrode of the second light-emitting control transistor is connected to the first end of the driving module, and the control electrode of the first light-emitting control transistor and the control electrode of the second light-emitting control transistor are both connected to the light-emitting control signal line.

[0023] Preferably, the driving module comprises a driving transistor, a first electrode of the driving transistor constitutes a first end of the driving module, a second electrode of the driving transistor constitutes a second end of the driving module, and a control electrode of the driving transistor constitutes a control end of the driving module.

[0024] Preferably, the light emitting module comprises an organic light emitting diode, a first electrode of the organic light emitting diode is connected to a first electrode of the driving transistor, and a second electrode of the organic light emitting diode is connected to a second power line.

[0025] A second aspect of the present application provides a display device, which includes a display panel and an under-screen light source, the under-screen light source is located on the backlight side of the display panel, and at least a portion of the display area of ​​the display panel is located within the illumination range of the under-screen light source; at least the area of ​​the display area illuminated by the under-screen light source is provided with a pixel circuit of any of the above-mentioned embodiments.

[0026] In one embodiment, the entire display area of ​​the display panel is provided with pixel circuits.

[0027] In one embodiment, the under-screen light source is used to emit incident light to an object to be identified located on the light-emitting side of the display panel, so that at least part of the incident light is reflected by the surface of the object to be identified to form reflected light; the display device also includes a biometric recognition component, the biometric recognition component includes a detection sensor and a biometric recognition device, the detection sensor is used to receive the reflected light to detect the biometric characteristics of the object to be identified; the biometric recognition device is used to perform biometric recognition based on the detected biometric characteristics.

[0028] In one embodiment, the light source under the screen is an infrared light source, and the detection sensor is an infrared camera.

[0029] In one embodiment, the display device is a full-screen display device.

[0030] The advantages or beneficial effects of the above technical solution include at least: by setting a current compensation module at the control end of the driving module, and electrically connecting the output end of the first reset module and the output end of the current compensation module to the control end of the driving module, the output end of the first reset module, the output end of the current compensation module and the control end of the driving module can be made to have the same potential. In this way, when the control end of the driving module is in the potential holding stage, the current compensation module can compensate for the potential of the control end of the driving module pulled down by the first reset module to stabilize the potential of the control end of the driving module, avoid the sudden increase in the driving current of the light-emitting module due to the change in the potential of the control end of the driving module, and thus effectively improve the screen flicker of the display panel and enhance the display quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. In addition, these drawings and text descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application for those skilled in the art by referring to specific embodiments.

[0032] Figure 1A FIG. 1 is a schematic diagram showing the structure of a pixel circuit in the related art.

[0033] Figure 1B Shown Figure 1A Schematic diagram of the potential distribution curve at each point in the pixel circuit.

[0034] Figure 2 Shown is a schematic diagram of the under-screen light source illuminating the pixel circuit.

[0035] Figure 3 Shown is a schematic diagram of the distribution of the luminous intensity of the light source under the screen.

[0036] Figure 4 Schematic diagram of the ID-VG measurement curve of low-temperature polysilicon thin-film transistor under different IR light powers.

[0037] Figure 5 FIG. 4 is a schematic diagram of the structure of a pixel circuit according to an embodiment of the present application.

[0038] Figure 6 FIG. 4 is a schematic structural diagram of a pixel circuit according to another embodiment of the present application.

[0039] Figure 7 Shown is a timing diagram of a pixel circuit according to an embodiment of the present application.

[0040] Figure 8 FIG. 4 is a schematic structural diagram of a pixel circuit according to another embodiment of the present application.

[0041] Fig. 9 FIG. 4 is a schematic structural diagram of a pixel circuit according to another embodiment of the present application.

[0042] Fig.10 FIG. 4 is a schematic structural diagram of a pixel circuit according to another embodiment of the present application.

[0043] Fig.11A FIG. 1 is a schematic diagram of a planar structure of a display device according to an embodiment of the present application.

[0044] Fig. 11B Shown Fig.11A Schematic diagram of the cross-sectional structure along the cutting line A1-A2. DETAILED DESCRIPTION

[0045] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0046] Figure 1A FIG. 1 is a schematic diagram showing the structure of a pixel circuit in the related art.

[0047] like Figure 1A As shown, taking the 7T1C pixel circuit as an example, the pixel circuit 10 of the related art includes 7 transistors and 1 storage capacitor C st , wherein the seven transistors include a driving transistor T1, a first reset transistor T2, a second reset transistor T3, a data writing transistor T4, a threshold compensation transistor T5, a first light emitting control transistor T6 and a second light emitting control transistor T7, and the pixel circuit 10 also includes an organic light emitting diode (OLED) D1, wherein the control electrode of the driving transistor T1 and the second electrode of the first reset transistor T2 are connected to the first node N1, and the first electrode of the first reset transistor T2 and the first electrode of the second reset transistor T3 are connected to the second node N2.

[0048] The inventor discovered during the implementation of this application: Figure 2 , taking the case where all transistors in the pixel circuit 10 are P-type transistors, when the backlight side of the display panel 30 is provided with an under-screen light source 20, when the driving transistor T1 on the pixel circuit 10 is in the potential holding stage, the first reset transistor T2 is in the cut-off state. If the pixel circuit 10 is irradiated by the under-screen light source 20, the first reset transistor T2 will generate a large photocurrent I DS, which may easily cause the potential of the control electrode (i.e., the first node N1) of the driving transistor T1 to change. For example, the potential of the control electrode of the driving transistor T1 may be pulled down, so that the driving transistor T1 enters the linear region. Then, when the driving transistor T1 drives the organic light emitting diode D1 to emit light, the driving current I generated by the driving transistor T1 may surge, and the organic light emitting diode D1 may flash in response to the driving current I, thereby causing the display panel 30 to flicker, thereby reducing the display quality.

[0049] The process by which the inventor discovered the above-mentioned problems in the related technology includes: Figure 3 and Figure 4 As shown, taking the under-screen light source 20 as an infrared (IR) light source as an example, Figure 3 FIG. 2 is a schematic diagram showing the distribution of the luminous intensity of the light source 20 under the screen. Figure 3 The horizontal axis represents time, Figure 3 The ordinate represents the luminous intensity of the screen light source 20, from Figure 3 It can be seen that the under-screen light source 20 usually periodically emits light toward the display panel 30, and the distribution diagram of the luminous intensity of the under-screen light source 20 is similar to a pulse waveform; Figure 4 Schematic diagram of the ID-VG measurement curve of the low-temperature polysilicon thin film transistor (LTPS TFT) under different IR light powers, where the horizontal axis represents the gate-source voltage V of the low-temperature polysilicon thin film transistor under different IR light powers GS The vertical axis represents the leakage current I of the low-temperature polysilicon thin-film transistor under different IR light powers. D , taking the low temperature polysilicon thin film transistor as a P-type thin film transistor as an example, from Figure 3 and Figure 4 It can be seen that when V GS >0, the low-temperature polysilicon thin-film transistor is in the cut-off state, and its leakage current I D The generation frequency responds to the light emission frequency of the light source 20 under the screen; and, combined with the following Table 1, it can be seen that when the low-temperature polysilicon thin film transistor is in the off state, if the IR light power of the light source 20 under the screen is 0W, the leakage current I of the low-temperature polysilicon thin film transistor D =1.18×10 -12 A; If the IR light power of the light source 20 under the screen is 2.25W, the leakage current I of the low-temperature polysilicon thin film transistor D =9.60×10 -11 A; If the IR light power of the light source 20 under the screen is 2.85W, the leakage current I of the low-temperature polysilicon thin film transistor D =1.53×10 -10 A; If the IR light power of the light source 20 under the screen is 3.46W, the leakage current I of the low-temperature polysilicon thin film transistorD =9.42×10 -11 A; If the IR light power of the light source 20 under the screen is 4.05W, the leakage current I of the low-temperature polysilicon thin film transistor D =8.62×10 -11 A; It can be seen that when the light source 20 under the screen does not illuminate the low-temperature polysilicon thin film transistor, its leakage current I D About 1×10 -12 A, and when the light source 20 under the screen illuminates the low-temperature polysilicon thin film transistor, its leakage current I D About 1×10 -10 A, the leakage current I of the low-temperature polysilicon thin film transistor under the illumination of the light source 20 under the screen D It is obvious that the leakage current I generated by the low-temperature polysilicon thin film transistor under the irradiation of the under-screen light source 20 is D Basically the photocurrent I DS In the related art, the control electrode potential of the driving transistor T1 is analyzed and it is known that the control electrode potential of the driving transistor T1 follows the photocurrent I generated by the driving transistor T1 DS Therefore, it can be determined that the screen flickering of the display panel 30 is caused by the first reset transistor T2 in the pixel circuit 10 generating a large photocurrent I under the illumination of the under-screen light source 20. DS cause.

[0050] Table 1 Leakage current of different low temperature polysilicon thin film transistors under different IR light powers

[0051] IR light power(W) LTPS TFT leakage current (A) 0 <![CDATA[1.18×10 -12 ]]> 2.25 <![CDATA[9.60×10 -11 ]]> 2.85 <![CDATA[1.53×10 -10 ]]> 3.46 <![CDATA[9.42×10 -11 ]]> 4.05 <![CDATA[8.62×10 -11 ]]>

[0052] Based on this, the embodiments of the present application provide a pixel circuit and a display device, which can effectively solve the above-mentioned problems of the related art. The embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0053] Figure 5 FIG. 4 is a schematic diagram of the structure of a pixel circuit according to an embodiment of the present application.

[0054] like Figure 5 As shown, the pixel circuit 10 includes a driving module 101, a light emitting module 102, a first reset module 103 and a current compensation module 110. The driving module 101 is used to drive the light emitting module 102 to emit light according to the potential of its control terminal. The output end of the first reset module 103 and the output end of the current compensation module 110 are both connected to the control end of the driving module 101, so that the current compensation module 110 compensates for the potential of the control end of the driving module 101 pulled down by the first reset module 103 when the control end of the driving module 101 is in the potential holding stage.

[0055] Exemplarily, when the control end of the driving module 101 is in the potential holding stage, the first reset module 103 generates a first current I flowing from the output end of the first reset module 103 to the input end. DS1 , thereby lowering the potential of the control terminal of the driving module 101; at the same time, the current compensation module 110 generates a second current I flowing from the input terminal of the current compensation module 110 to the output terminal DS2 , the second current I DS2 is the first current I generated by the first reset module 103 DS1 The reverse current can be obtained by DS1 The current compensation is performed to compensate for the potential of the control terminal of the driving module 101 pulled down by the first reset module 103, thereby maintaining the stability of the potential of the control terminal of the driving module 101. DS1 It can be the first photocurrent generated by the first reset module 103 under the illumination of the under-screen light source 20, and the second current I DS2 It may be the second photocurrent generated by the current compensation module 110 under the illumination of the under-screen light source 20 .

[0056] Specifically, the driving module 101 includes a driving transistor T1, a first electrode of the driving transistor T1 constitutes a first end of the driving module 101, a second electrode of the driving transistor T1 constitutes a second end of the driving module 101, a control electrode of the driving transistor T1 constitutes a control end of the driving module 101, and the first electrode of the driving transistor T1 is connected to a first end of the light emitting module 102. Since the light emitting module 102 is a current type device, it needs to emit light in response to a driving current I generated by the driving transistor T1, and the magnitude of the driving current I generated by the driving transistor T1 is determined by the potential of the control end of the driving transistor T1. Therefore, by maintaining the stability of the potential of the control end of the driving transistor T1, the driving transistor T1 can be made to work in a saturation region and avoid the driving transistor T1 from entering a linear region, thereby ensuring that the fluctuation amplitude of the driving current I generated by the driving transistor T1 is small, and thus the light emitting module 102 emits light with a relatively stable brightness in response to the driving current I.

[0057] The above scheme, by setting the current compensation module 110 at the control end of the driving module 101, and electrically connecting the output end of the first reset module 103 and the output end of the current compensation module 110 to the control end of the driving module 101, can make the output end of the first reset module 103, the output end of the current compensation module 110 and the control end of the driving module 101 have the same potential. In this way, when the control end of the driving module 101 is in the potential holding stage, the current compensation module 110 can compensate for the control end potential of the driving module 101 pulled down by the first reset module 103, so as to stabilize the control end potential of the driving module 101 and avoid the driving current I of the light-emitting module 102 from surging and flashing due to the change of the control end potential of the driving module 101, thereby effectively improving the screen flickering degree of the display panel 30 and improving the display quality.

[0058] In one embodiment, please refer to Figure 5 , the potential holding stage includes a light-emitting stage, the driving module 101 is used to drive the light-emitting module 102 to emit light during the light-emitting stage, and the current compensation module 110 is used to perform potential compensation on the control end of the driving module 101 during the light-emitting stage. In practical applications, the potential of the control end of the driving module 101 is directly proportional to the light-emitting brightness of the light-emitting module 102, and the time of the light-emitting stage accounts for 90% of the total time of all working stages of the pixel circuit 10. Therefore, by setting the current compensation module 110 to perform potential compensation on the control end of the driving module 101 during the light-emitting stage, it can be ensured that the potential of the control end of the driving module 101 remains stable during the light-emitting stage, thereby driving the light-emitting module 102 to emit light with relatively stable brightness during the light-emitting stage, thereby improving the screen flicker of the display panel 30 and improving the display quality.

[0059] In an optional embodiment, if Figure 6 As shown, the input end of the current compensation module 110 is connected to the control end of the current compensation module 110, so that the current compensation module 110 is in a cut-off state.

[0060] Exemplarily, taking the current compensation module 110 including the current compensation transistor T8, and the current compensation transistor T8 being a P-type transistor as an example, the second electrode of the current compensation transistor T8 constitutes the input end of the current compensation module 110, the first electrode of the current compensation transistor T8 constitutes the output end of the current compensation module 110, and the control electrode of the current compensation transistor T8 constitutes the control end of the current compensation module 110. By connecting the second electrode of the current compensation transistor T8 to the control electrode, the current compensation transistor T8 can be made to form a reverse bias connection structure, so that the voltage V between the control electrode and the second electrode of the current compensation transistor T8 GS =0V, and due to the threshold voltage V this less than 0, so the voltage V between the control electrode and the second electrode of the current compensation transistor T8 can be GS >V th , ensuring that the current compensation transistor T8 is in the cut-off state. Based on this, the current compensation module 110 can be used only to generate the second current I DS2 And cannot be conducted.

[0061] In another optional embodiment, if Figure 8 As shown, the control end of the current compensation module 110 is used to access the cut-off signal VGH, so that the current compensation module 110 is in a cut-off state.

[0062] As an example, continuing to take the current compensation module 110 including the current compensation transistor T8, and the current compensation transistor T8 is a P-type transistor, the second electrode of the current compensation transistor T8 constitutes the input end of the current compensation module 110, the first electrode of the current compensation transistor T8 constitutes the output end of the current compensation module 110, and the control electrode of the current compensation transistor T8 constitutes the control end of the current compensation module 110. The control electrode of the current compensation transistor T8 can receive the cut-off signal VGH in all working stages of the pixel circuit 10, so that the current compensation transistor T8 is cut off in response to the cut-off signal VGH in all working stages of the pixel circuit 10, thereby ensuring that the current compensation module 110 can only be used to generate the second current I DS2 Instead, the current compensation module 110 cannot be turned on, thereby preventing data from being written to the control terminal of the driving module 101 .

[0063] Preferably, the cutoff signal VGH connected to the control electrode of the current compensation transistor T8 is high level. It should be noted that the current compensation transistor T8 can also use an N-type transistor according to actual needs. When the current compensation transistor T8 uses an N-type transistor, the cutoff signal connected to the control electrode of the current compensation transistor T8 is low level.

[0064] In one embodiment, Figure 5 As shown, the input end of the current compensation module 110 is connected to the data signal line V data Electrically connected to receive a data voltage during a data writing phase.

[0065] The inventors also found in the process of implementing this application: Figure 1A and Figure 1B , at different gray scales, the potential of the control electrode of the driving transistor T1 is higher than the potential of the first electrode of the first reset transistor T2, that is, the potential V N1 higher than the potential V of the second node N2 N2 , data voltage V ′ datais higher than the control electrode potential of the driving transistor T1, and the control electrode potential of the driving transistor T1 (that is, the potential V N1 ) varies with the data voltage V ′ data increases and increases with the data voltage V ′ data becomes smaller and smaller, making the data voltage V ′ data The magnitude of the current compensation module 110 is related to the potential of the input terminal (ie, the potential V N3 )Demand is close.

[0066] In the above solution, by setting the input end of the current compensation module 110 and the data signal line V data Electrically connected to receive the data voltage V during the data writing phase ′ data , the data voltage V required by the pixel circuit 10 itself can be used ′ data To maintain the input potential of the current compensation module 110, there is no need to design a voltage signal auxiliary circuit for the input of the current compensation module 110 or use a chip to provide a special voltage signal to the input of the current compensation module 110, which is conducive to reducing the manufacturing cost of the pixel circuit 10; and the input of the current compensation module 110 receives the data voltage V ′ data The magnitude of the potential at the input terminal of the current compensation module 110 can also be changed as the grayscale changes, so that the second photocurrent I generated by the current compensation module 110 is DS2 It can adapt to different grayscales and has better current compensation effect.

[0067] In one embodiment, Figure 5 As shown, the output end of the first reset module 103, the output end of the current compensation module 110 and the control end of the driving module 101 are all connected to the first node N1, the input end of the first reset module 103 is connected to the second node N2, and the input end of the current compensation module 110 constitutes the third node N3; in the potential holding stage, the potential of the third node N3 is higher than the potential of the first node N1, and the potential of the first node N1 is higher than the potential of the second node N2. Based on this, in the potential holding stage, the first current I generated by the first reset module 103 DS1 When the second current I generated by the current compensation module 110 flows from the first node N1 to the second node N2 and pulls down the potential of the first node N1, DS2 From the third node N3 to the first node N1, the first current I flowing out of the first node N1 can be DS1 Compensation is performed to reduce the potential V of the first node N1. N1Furthermore, since the control terminal of the driving module 101 is connected to the first node N1, the potential of the control terminal of the driving module 101 is V N1 Therefore, the fluctuation amplitude of the potential of the control terminal of the driving module 101 can be reduced, which is helpful to maintain the stability of the potential of the control terminal of the driving module 101.

[0068] In one embodiment, Figure 5 As shown, the potential difference V between the third node N3 and the first node N1 N3 -V N1 = equal to the potential difference V between the first node N1 and the second node N2 N1 -V N2 .

[0069] In practical applications, since the current compensation module 110 and the first reset module 103 in the pixel circuit 10 are usually made by the same process, the performance of the current compensation module 110 and the first reset module 103 are substantially the same. In this embodiment, since the input end of the current compensation module 110 is connected to the third node N3, the output end of the current compensation module 110, the control end of the driving module 101 and the output end of the first reset module 103 are all connected to the first node N1, and the input end of the first reset module 103 is connected to the second node N2, the potential difference V between the third node N3 and the first node N1 is set. N3 -V N1 = equal to the potential difference V between the first node N1 and the second node N2 N1 -V N2 , the potential difference between the output terminal of the current compensation module 110 and the control terminal of the driving module 101 can be equal to the potential difference between the control terminal of the driving module 101 and the input terminal of the first reset module 103, ensuring that the second current I generated by the current compensation module 110 DS2 The first current I generated by the first reset module 103 DS1 The same magnitude and opposite flow direction can make the second current I generated by the current compensation module 110 DS2 Can completely compensate the first current I generated by the first reset module 103 DS1 , ensuring that the potential of the control end of the driving module 101 is stable.

[0070] In one embodiment, Figure 5 As shown, the input terminal of the first reset module 103 is connected to the reset signal line V ref The control end of the first reset module 103 is connected to the first scan signal line Scan1. The first reset module 103 is also used to reset the reset signal line V refThe reset voltage on the control terminal of the driving module 101 is transmitted to the control terminal of the driving module 101 to reset the potential of the control terminal of the driving module 101.

[0071] In an alternative example, Figures 5 to 7 As shown, the first reset module 103 includes a first reset transistor T2, a second electrode of the first reset transistor T2 is connected to the first node N1, and a first electrode of the first reset transistor T2 is connected to the second node N2 and connected to the reset signal line V ref The control terminal of the first reset transistor T2 is connected to the first scan signal line Scan1. In the reset phase t1, the first scan signal on the first scan signal line Scan1 is at an effective level, and the control terminal of the first reset transistor T2 is turned on when receiving the first scan signal, so that the signal line V ref The reset voltage on the driving module 101 is transmitted to the control terminal of the driving module 101 via the first reset transistor T2 to reset the potential of the control terminal of the driving module 101.

[0072] In another alternative example, if Figure 5 , Fig. 9 and Fig.10 As shown, the first reset module 103 includes a first sub-reset transistor T21 and a second sub-reset transistor T22, the second electrode of the first sub-reset transistor T21 is connected to the first node N1, the first electrode of the first sub-reset transistor T21 is connected to the second electrode of the second sub-reset transistor T22, the first electrode of the second sub-reset transistor T22 is connected to the second node N2 and connected to the reset signal line V ref The control electrode of the first sub-reset transistor T21 and the control electrode of the second sub-reset transistor T22 are both connected to the first scan signal line Scan1.

[0073] Please also read Figure 7 In the reset phase t1, the first scan signal on the first scan signal line Scan1 is at an effective level, and the control electrode of the first sub-reset transistor T21 and the control electrode of the second sub-reset transistor T22 are turned on when receiving the first scan signal, so that the signal line V ref The reset voltage on the control terminal of the driving module 101 is transmitted to the control terminal of the driving module 101 via the second sub-reset transistor T22 and the first sub-reset transistor T21 in sequence, so as to reset the potential of the control terminal of the driving module 101.

[0074] In one embodiment, Figure 5 As shown, the pixel circuit 10 further includes a second reset module 104, which is connected to the reset signal line V ref and the first end of the light emitting module 102, and the control end of the second reset module 104 is electrically connected to the first scan signal line Scan1. Figure 7In the reset phase t1, the second reset module 104 receives the first scan signal on the first scan signal line Scan1, and resets the signal line V ref The reset voltage on the first terminal of the light emitting module 102 is transmitted to the first terminal of the light emitting module 102 via the second reset module 104 to reset the first terminal of the light emitting module 102 .

[0075] For example, Figure 5 and Figure 6 As shown, the second reset module 104 includes a second reset transistor T3, the second electrode of the second reset transistor T3 is connected to the first end of the light emitting module 102, and the first electrode of the second reset transistor T3 is connected to the reset signal line V ref The control electrode of the second reset transistor T3 is connected to the first scanning signal line Scan1. Figure 7 In the reset stage t1, the first scan signal on the first scan signal line Scan1 is at an effective level, and the control electrode of the second reset transistor T3 is turned on when receiving the first scan signal, so that the reset signal line V ref The reset voltage on the transistor T3 is transmitted to the first end of the light emitting module 102 via the second reset transistor T3 to reset the first end of the light emitting module 102 .

[0076] In one embodiment, Figure 5 As shown, the pixel circuit 10 further includes a data writing module 106 and a threshold compensation module 107. The data writing module 106 is connected to the data signal line V data The threshold compensation module 107 is connected between the first end of the driving module 101 and the control end of the driving module 101. The control end of the data writing module 106 and the control end of the threshold compensation module 107 are both connected to the second scanning signal line Scan2. The data writing module 106 is used to set the data signal line V data The data voltage is transmitted to the control end of the driving module 101 via the threshold compensation module 107. The threshold compensation module 107 is used to perform threshold compensation on the potential of the control end of the driving module 101 during the data writing phase.

[0077] In one example, if Figure 5 and Figure 6 As shown, the data writing module 106 includes a data writing transistor T4, a first electrode of the data writing transistor T4 is connected to the second end of the driving module 101, and a second electrode of the data writing transistor T4 is connected to the data signal line V dataThe control electrode of the data writing transistor T4 is connected to the second scanning signal line Scan2. The threshold compensation module 107 includes a threshold compensation transistor T5, a first electrode of the threshold compensation transistor T5 is connected to the control end of the driving module 101, a second electrode of the threshold compensation transistor T5 is connected to the first end of the driving module 101, and a control electrode of the threshold compensation transistor T5 is connected to the second scanning signal line Scan2.

[0078] Please also read Figure 7 In the data writing stage t2, the second scanning signal on the second scanning signal line Scan2 is at an effective level. When the control electrode of the data writing transistor T4 and the control electrode of the threshold compensation transistor T5 receive the second scanning signal, the data writing transistor T4 and the threshold compensation transistor T5 are both turned on. Since the potential of the control terminal of the driving module 101 is maintained at an effective potential after being reset in the reset stage t1, the driving module 101 is also in a conducting state, so that the data signal line V data The data voltage V ′ data The data is sequentially transmitted to the control terminal of the driving module 101 through the data writing transistor T4, the driving module 101 and the threshold compensation transistor T5. The threshold compensation transistor T5 is used to adjust the control terminal potential of the driving module 101 (that is, the potential V N1 ) performs threshold compensation so that the data voltage V written into the control terminal of the driving module 101 ′ d ′ ata =V ′ data +V th , where V ′ data V is the data signal line data The data voltage on the th is the threshold voltage of the threshold compensation transistor T5, and the written data voltage V ′ d ′ ata With a threshold voltage V th Based on this, it is possible to write the data voltage V to the control terminal of the driving module 101. ′ d ′ ata .

[0079] In another example, Figure 5 and Fig. 9As shown, the data writing module 106 includes a data writing transistor T4. The connection method of the data writing transistor T4 in the pixel circuit 10 can refer to the above example, and the difference is that: the threshold compensation module 107 includes a first sub-threshold compensation transistor T51 and a second sub-threshold compensation transistor T52. The first electrode of the first sub-threshold compensation transistor T51 is connected to the control end of the driving module 101, the second electrode of the first sub-threshold compensation transistor T51 is connected to the first electrode of the second sub-threshold compensation transistor T52, the second electrode of the second sub-threshold compensation transistor T52 is connected to the first end of the driving module 101, and the control electrode of the first sub-threshold compensation transistor T51 and the control electrode of the second sub-threshold compensation transistor T52 are both connected to the second scanning signal line Scan2.

[0080] Please also read Figure 7 In the data writing stage t2, the second scanning signal on the second scanning signal line Scan2 is at an effective level. When the control electrode of the data writing transistor T4, the control electrode of the first sub-threshold compensation transistor T51 and the control electrode of the second sub-threshold compensation transistor T52 receive the second scanning signal, the data writing transistor T4, the first sub-threshold compensation transistor T51 and the second sub-threshold compensation transistor T52 are turned on. Since the potential of the control terminal of the driving module 101 is maintained at an effective potential after being reset in the reset stage t1, the driving module 101 is also in a conducting state, so that the data signal line V data The data voltage V ′ data The data is sequentially transmitted to the control terminal of the driving module 101 through the data writing transistor T4, the driving module 101, the second sub-threshold compensation transistor T52 and the first sub-threshold compensation transistor T51. The first sub-threshold compensation transistor T51 and the second sub-threshold compensation transistor T52 are used to adjust the potential of the control terminal of the driving module 101 (that is, the potential V N1 ) performs threshold compensation so that the data voltage V written into the control terminal of the driving module 101 ′ d ′ ata =V ′ data +V th , where V ′ data V is the data signal line data The data voltage on the th is the threshold voltage of the first sub-threshold compensation transistor T51 and the second sub-threshold compensation transistor T52. Based on this, it is possible to write the data voltage V to the control terminal of the driving module 101. ′ d ′ ata .

[0081] In one embodiment, Figure 5 As shown, the pixel circuit 10 further includes a storage module 105, which is connected to the first power line V dd The storage module 101 is used to store the data voltage written by the control end of the driving module 101 .

[0082] Preferably, Figure 6 As shown, the storage module 101 includes a storage capacitor C st , storage capacitor C st The first electrode and the first power line V dd Connection, storage capacitor C st The second electrode of is connected to the control terminal of the driving module 101. Figure 7 In the data writing phase t2, when the data voltage is written and the threshold voltage is compensated to the control end of the driving module 101, the storage capacitor C st The first electrode is charged until the storage capacitor C st The potential of the first electrode reaches V ′ d ′ ata , to write the data voltage V at the control end of the driver module 101 ′ d ′ ata for storage.

[0083] In one embodiment, Figure 5 As shown, the pixel circuit 10 further includes a first light emitting control module 108 and a second light emitting control module 109. The first light emitting control module 108 is connected to the first power line V dd The second light-emitting control module 109 is connected between the first end of the driving module 101 and the first end of the light-emitting module 102. The control end of the first light-emitting control module 108 and the control end of the second light-emitting control module 109 are both connected to the light-emitting control signal line EM. The first light-emitting control module 108 is used to control the first power line V dd The first power supply voltage is transmitted to the second end of the driving module 101, and the second light-emitting control module 109 is used to electrically connect the first end of the driving module 101 and the first end of the light-emitting module 102 in the light-emitting stage.

[0084] For details, please refer to Figure 7 In the light-emitting stage t3, the light-emitting control signal on the light-emitting control signal line EM is at an effective level, and the control end of the first light-emitting control module 108 and the control end of the second light-emitting control module 109 are turned on when receiving the light-emitting control signal, and the first power line Vdd The first power supply voltage is transmitted to the second end of the driving module 101 through the first light-emitting control module 108, and the second light-emitting control module 109 electrically connects the first end of the driving module 101 with the first end of the light-emitting module 102, so that the driving module 101 drives the light-emitting module 102 to emit light according to the potential of its control end.

[0085] Preferably, Figure 6 As shown, the first light control module 108 includes a first light control transistor T6, and the second light control module 109 includes a second light control transistor T7. The first electrode of the first light control transistor T6 is connected to the second end of the driving module 101, and the second electrode of the first light control transistor T6 is connected to the first power line V dd The first electrode of the second light-emitting control transistor T7 is connected to the first end of the light-emitting module 102, the second electrode of the second light-emitting control transistor T7 is connected to the first end of the driving module 101, and the control electrode of the first light-emitting control transistor T6 and the control electrode of the second light-emitting control transistor T7 are both connected to the light-emitting control signal line EM. Among them, the first electrode of the first light-emitting control transistor T6 constitutes the first end of the first light-emitting control module 108, the second electrode of the first light-emitting control transistor T6 constitutes the second end of the first light-emitting control module 108, and the control electrode of the first light-emitting control transistor T6 constitutes the control end of the first light-emitting control module 108; the second electrode of the second light-emitting control transistor T7 constitutes the second end of the second light-emitting control module 109, the second electrode of the second light-emitting control transistor T7 constitutes the second end of the second light-emitting control module 109, and the control electrode of the second light-emitting control transistor T7 constitutes the control end of the second light-emitting control module 109.

[0086] Preferably, Figure 5 As shown, the second end of the light emitting module 102 is connected to the second power line V ss The light emitting module 102 includes an organic light emitting diode D1, a first electrode of the organic light emitting diode D1 is connected to a first electrode of the driving transistor T1, and a second electrode of the organic light emitting diode D1 is connected to a second power line V ss connect.

[0087] Figure 7 The following is a timing diagram of the pixel circuit of the embodiment of the present application. Figure 6 and Figure 7 A specific structure of the pixel circuit 10 of the present application and its working timing are described, but they are not intended to limit the present application.

[0088] like Figure 6 and Figure 7As shown, the driving module 101 includes a driving transistor T1, the light emitting module 102 includes an organic light emitting diode D1, the first reset module 103 includes a first reset transistor T2, the second reset module 104 includes a second reset transistor T3, and the storage module 105 includes a storage capacitor C st The data writing module 106 includes a data writing transistor T4, the threshold compensation module 107 includes a threshold compensation transistor T5, the first light emitting control module 108 includes a first light emitting control transistor T6, the second light emitting control module 109 includes a second light emitting control transistor T7, and the current compensation module 110 includes a current compensation transistor T8.

[0089] The control electrode of the driving transistor T1 is connected to the first node N1 with the second electrode of the first reset transistor T2 and the first electrode of the current compensation transistor T8. The first electrode of the first reset transistor T2 and the first electrode of the second reset transistor T3 are connected to the second node N2 and connected to the reset signal line V ref The control electrode of the first reset transistor T2 and the control electrode of the second reset transistor T3 are both connected to the first scan signal line Scan1, the second electrode of the current compensation transistor T8 constitutes a third node N3, and the control electrode of the current compensation transistor T8 is connected to the second electrode of the current compensation transistor T8. The first electrode of the driving transistor T1 is connected to the first electrode of the organic light emitting diode D1, the first electrode of the organic light emitting diode D1 is also connected to the second electrode of the second reset transistor T3, and the second electrode of the organic light emitting diode D1 is connected to the second power line V ss The first electrode and the second electrode of the organic light emitting diode D1 can be connected to each other as the anode and the cathode. st The first electrode of the storage capacitor C is connected to the control electrode of the driving transistor T1. st The second electrode is connected to the first power line V dd The first electrode of the data writing transistor T4 is connected to the second electrode of the driving transistor T1, and the second electrode of the data writing transistor T4 is connected to the data signal line V data The first electrode of the threshold compensation transistor T5 is connected to the control electrode of the driving transistor T1, the second electrode of the threshold compensation transistor T5 is connected to the first electrode of the driving transistor T1, and the control electrodes of the data writing transistor T4 and the threshold compensation transistor T5 are both connected to the second scanning signal line Scan2. The first electrode of the first light emitting control transistor T6 is connected to the second electrode of the driving transistor T1, and the second electrode of the first light emitting control transistor T6 is connected to the first power line V dd The first electrode of the second light emitting control transistor T7 is connected to the first electrode of the organic light emitting diode D1, the second electrode of the second light emitting control transistor T7 is connected to the first electrode of the driving transistor T1, and the control electrode of the first light emitting control transistor T6 and the control electrode of the second light emitting control transistor T7 are both connected to the light emitting control signal line EM.

[0090] The working process of the pixel circuit 10 includes a reset phase t1, a data writing phase t2 and a light emitting phase t3. Taking the example that all transistors in the pixel circuit 10 are P-type transistors, the working phases of the pixel circuit 10 are described.

[0091] In the reset stage t1, the first scan signal on the first scan signal line Scan1 is at an effective level, the second scan signal on the second scan signal line Scan2 and the light emitting control signal on the light emitting control signal line EM are both at an ineffective level, the control electrode of the first reset transistor T2 and the control electrode of the second reset transistor T3 receive an effective level, so that the first reset transistor T2 and the second reset transistor T3 are turned on, and other transistors in the pixel circuit 10 are turned off, and the reset signal line V ref The reset voltage on the first reset transistor T2 is transmitted to the control electrode of the driving transistor T1 to reset the control electrode of the driving transistor T1, that is, to reset the first node N1 and make the storage capacitor C st The first electrode of the organic light emitting diode D1 stores the reset voltage, and the reset voltage is also transmitted to the first electrode of the organic light emitting diode D1 through the second reset transistor T3 to reset the first electrode of the organic light emitting diode D1, so that the voltage of the first electrode of the organic light emitting diode D1 is equal to the reset voltage, and the second electrode of the organic light emitting diode D1 receives the second power line V ss The second power supply voltage VSS is provided on the power supply, and the second power supply voltage VSS may be equal to the reset voltage.

[0092] In the data writing stage t2, the second scanning signal on the second scanning signal line Scan2 is at an effective level, the first scanning signal on the first scanning signal line Scan1 and the light emitting control signal on the light emitting control signal line EM are both at an invalid level, the control electrode G of the data writing transistor T4 and the control electrode G of the threshold compensation transistor T5 both receive an effective level, so that the data writing transistor T4 and the threshold compensation transistor T5 are turned on, and due to the storage capacitor C st The reset voltage stored in the first electrode of is the effective level of the driving transistor T1, which can turn on the driving transistor T1, and turn off other transistors in the pixel circuit 10, thereby turning off the data signal line V data The data voltage V data 'Through the data writing transistor T4, the driving transistor T1 and the threshold compensation transistor T5, the storage capacitor C st The first electrode of the driving transistor T1 is charged until the potential of the control electrode reaches V ′ data +V th , that is, the potential V of the first node N1 N1 =V ′ d′ ata =V ′ data +V th , at this time the storage capacitor C st The first electrode stores the data voltage V written by the control electrode of the driving transistor T1 ′ d ′ ata .

[0093] In the light-emitting stage t3, the level on the light-emitting control signal line EM is at an effective level, the levels on the first scanning signal line Scan1 and the second scanning signal line Scan2 are both at an invalid level, the control electrode of the first light-emitting control transistor T6 and the control electrode of the second light-emitting control transistor T7 receive an effective level, so that the first light-emitting control transistor T6 and the second light-emitting control transistor T7 are both turned on, and the storage capacitor C st The stored data voltage V ′ d ′ ata is the effective level of the driving transistor T1, which can turn on the driving transistor T1 and turn off other transistors in the pixel circuit 10, so that the first power line V dd The first power supply voltage on the first light emitting diode N1 provides a driving current I to the organic light emitting diode D1 through the first light emitting control transistor T6, the driving transistor T1 and the second light emitting control transistor T7, so as to control the organic light emitting diode D1 to emit light, wherein the light emitting brightness of the organic light emitting diode D1 is determined by the control electrode potential of the driving transistor T1, that is, by the potential V N1 In the light emitting stage t3, if the under-screen light source 20 illuminates the pixel circuit 10, the first reset transistor T2 generates a first photocurrent I flowing from the first node N1 to the second node N2. DS1 The current compensation transistor T8 generates a second photocurrent I flowing from the third node N3 to the first node N1. DS2 , the first photocurrent I DS1 Compensation is performed to maintain the potential V of the first node N1 th Stable, because the potential V N1 The potential of the control electrode of the driving transistor T1 is the same as that of the control electrode of the driving transistor T1 , so the potential of the control electrode of the driving transistor T1 can be maintained stable, thereby ensuring the stability of the light emitting brightness of the organic light emitting diode D1 .

[0094] In the above example, the control electrode, the first electrode, and the second electrode of the transistor in the pixel circuit 10 may correspond one-to-one to the gate electrode, the drain electrode, and the source electrode of each transistor.

[0095] It should be noted that the above-mentioned effective level may be a low level, and the invalid level may be a high level; the effective level may also be a high level, and the invalid level may be a low level; Figure 7 The case where the effective level is a low level and the ineffective level is a high level is shown, but it is not limited to this. The transistors in the pixel circuit 10 can all be P-type transistors; or, the transistors in the pixel circuit 10 can all be N-type transistors; or, the transistors in the pixel circuit 10 can be partially P-type transistors and partially N-type transistors; in the embodiment of the present application, only the case where the transistors in the pixel circuit 10 are all P-type transistors is shown, but it is not limited to this. Preferably, the transistors in the pixel circuit 10 can be low-temperature polysilicon thin film transistors.

[0096] Fig.11A FIG. 1 is a schematic diagram of a planar structure of a display device according to an embodiment of the present application. Fig. 11B Shown Fig.11A Schematic diagram of the cross-sectional structure along the cutting line A1-A2.

[0097] like Fig.11A and Fig. 11B As shown, the display device 100 includes a display panel 30 and an under-screen light source 20, the under-screen light source 20 is located on the backlight side of the display panel 30, and at least a portion of the display area AA of the display panel 30 is located within the illumination range of the under-screen light source 20; at least the area AA1 in the display area AA that is illuminated by the under-screen light source 20 is provided with a pixel circuit 10 of any of the above-mentioned embodiments.

[0098] Exemplarily, the display panel 30 includes a display area AA and a non-display area NAA located around the display area AA. By setting the pixel circuit 10 of the embodiment of the present application in the area AA1 of the display area AA illuminated by the under-screen light source 20, it can be ensured that the luminous brightness of the area AA1 of the display area AA illuminated by the under-screen light source 20 is stable, which is beneficial to improving the screen flicker in the area AA1 and improving the display quality.

[0099] In one embodiment, Fig.11A and Fig. 11B , all display areas AA of the display panel 30 are provided with pixel circuits 10. By providing the pixel circuits 10 of the embodiment of the present application in all display areas AA of the display panel 30, the uniformity of the display brightness of the display panel 30 can be ensured, which helps to further improve the display quality.

[0100] In one embodiment, the under-screen light source 20 is used to emit incident light L1 to the object to be identified 200 located on the light-emitting side of the display panel 30, so that at least part of the incident light L1 is reflected by the surface of the object to be identified 200 to form reflected light L2. The object to be identified 200 includes a face or a finger.

[0101] The display device 100 further includes a biometric identification component 40, which includes a detection sensor and a biometric identification device (not shown in the drawings), wherein the detection sensor is used to receive the reflected light L2 to detect the biometrics of the object to be identified 200, and the biometric identification device is used to perform biometric identification based on the detected biometrics. The biometric identification may be facial recognition or fingerprint recognition.

[0102] In one example, the under-screen light source 20 can be an infrared light source, and the detection sensor can be an infrared camera. The under-screen light source 20 emits infrared light toward the object to be identified 200, so that part of the infrared light is reflected by the surface of the object to be identified 200 and then captured by the infrared camera, thereby forming an infrared image of the object to be identified, and then the infrared image can be used to identify the biometric features of the object to be identified.

[0103] In the above scheme, by setting a biometric identification component 40 in the display device 100, the biometric identification component 40 can be used to perform biometric identification on the object to be identified 200, so that the pixel circuit 10 of the present application can be suitable for the display device 100 with a biometric identification function.

[0104] In one embodiment, Fig.11A and Fig. 11B , the display device 100 is a full-screen display device. Exemplarily, the biometric identification component 40 is arranged on the backlight side of the display panel 30. By integrating the biometric identification component 40 with the under-screen light source 20 on the backlight side of the display panel 30, the display device 100 can constitute a full-screen display device, thereby greatly improving the screen-to-body ratio of the display panel 30 and improving the user experience. It should be noted that the type of display device 100 can also be selected and adjusted according to actual needs, and the display device 100 of the embodiment of the present application is not limited to a full-screen display device.

[0105] It should be noted that, since the display device 100 of the embodiment of the present application adopts all the technical solutions of all the embodiments of the above-mentioned pixel circuit 10, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0106] In addition, in this application, unless otherwise clearly specified and limited, the terms "connected", "connected", "stacked" and the like should be understood in a broad sense, for example, it can be fixedly connected, detachably connected, or integrated; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0107] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they contradict each other.

[0108] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0109] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A pixel circuit, characterized in that: The pixel circuit includes a driving module, a light emitting module, a first reset module and a current compensation module; The driving module is used to drive the light-emitting module to emit light according to the potential of its control terminal; The output end of the first reset module and the output end of the current compensation module are both electrically connected to the control end of the driving module, so that when the control end of the driving module is in a potential holding stage, the current compensation module compensates for the potential of the control end of the driving module pulled down by the first reset module.

2. The pixel circuit according to claim 1, characterized in that: The potential holding stage includes a light-emitting stage, the driving module is used to drive the light-emitting module to emit light during the light-emitting stage, and the current compensation module is used to perform potential compensation on the control end of the driving module during the light-emitting stage; Preferably, the input end of the current compensation module is connected to the control end of the current compensation module, so that the current compensation module is in a cut-off state; Alternatively, the control end of the current compensation module is used to receive a cut-off signal to put the current compensation module in a cut-off state; Preferably, the input end of the current compensation module is electrically connected to the data signal line to receive the data voltage during the data writing phase; Preferably, the current compensation module includes a current compensation transistor, the second electrode of the current compensation transistor constitutes the input end of the current compensation module, the first electrode of the current compensation transistor constitutes the output end of the current compensation module, and the control electrode of the current compensation transistor constitutes the control end of the current compensation module.

3. The pixel circuit according to claim 1, characterized in that: The output end of the first reset module, the output end of the current compensation module and the control end of the driving module are all connected to a first node, the input end of the first reset module is connected to a second node, and the input end of the current compensation module constitutes a third node; in the potential holding stage, the potential of the third node is higher than the potential of the first node, and the potential of the first node is higher than the potential of the second node; Preferably, in the potential holding stage, the potential difference between the third node and the first node is equal to the potential difference between the first node and the second node; Preferably, the input end of the first reset module is connected to the reset signal line, the control end of the first reset module is connected to the first scanning signal line, and the first reset module is also used to transmit the reset voltage on the reset signal line to the control end of the driving module during the reset stage.

4. The pixel circuit according to claim 3, characterized in that: The first reset module comprises a first reset transistor, a second electrode of the first reset transistor is connected to the first node, a first electrode of the first reset transistor is connected to the second node and connected to the reset signal line, and a control end of the first reset transistor is connected to the first scan signal line; Alternatively, the first reset module includes a first sub-reset transistor and a second sub-reset transistor, the second electrode of the first sub-reset transistor is connected to the first node, the first electrode of the first sub-reset transistor is electrically connected to the second electrode of the second sub-reset transistor, the first electrode of the second sub-reset transistor is connected to the second node and connected to the reset signal line, and the control electrode of the first sub-reset transistor and the control electrode of the second sub-reset transistor are both connected to the first scanning signal line.

5. The pixel circuit according to claim 1, characterized in that: The pixel circuit further includes a second reset module, the second reset module is connected between the reset signal line and the first end of the light emitting module, and a control end of the second reset module is electrically connected to the first scanning signal line; Preferably, the pixel circuit further comprises a data writing module and a threshold compensation module, the data writing module is connected between the data signal line and the second end of the driving module, the threshold compensation module is connected between the first end of the driving module and the control end of the driving module, the control end of the data writing module and the control end of the threshold compensation module are both connected to the second scanning signal line, and the data writing module is used to transmit the data voltage on the data signal line to the control end of the driving module via the threshold compensation module during the data writing stage; Preferably, the pixel circuit further comprises a storage module, the storage module is connected between the first power line and the control end of the driving module, and the storage module is used to store the data voltage written by the control end of the driving module; Preferably, the pixel circuit further comprises a first light-emitting control module and a second light-emitting control module, the first light-emitting control module is connected between the first power line and the second end of the driving module, the second light-emitting control module is connected between the first end of the driving module and the first end of the light-emitting module, the control end of the first light-emitting control module and the control end of the second light-emitting control module are both connected to the light-emitting control signal line, the first light-emitting control module is used to transmit the first power supply voltage on the first power line to the second end of the driving module in a light-emitting stage, and the second light-emitting control module is used to electrically connect the first end of the driving module with the first end of the light-emitting module in the light-emitting stage; Preferably, the second end of the light emitting module is connected to a second power line.

6. The pixel circuit according to claim 5, characterized in that: The second reset module comprises a second reset transistor, the second electrode of the second reset transistor is connected to the first end of the light emitting module, the first electrode of the second reset transistor is connected to the reset signal line, and the control electrode of the second reset transistor is connected to the first scanning signal line; Preferably, the data writing module comprises a data writing transistor, a first electrode of the data writing transistor is connected to the second end of the driving module, a second electrode of the data writing transistor is connected to the data signal line, and a control electrode of the data writing transistor is connected to the second scanning signal line; Preferably, the threshold compensation module includes a threshold compensation transistor, a first electrode of the threshold compensation transistor is connected to the control end of the driving module, a second electrode of the threshold compensation transistor is connected to the first end of the driving module, and a control electrode of the threshold compensation transistor is connected to the second scan signal line; or, the threshold compensation module includes a first sub-threshold compensation transistor and a second sub-threshold compensation transistor, a first electrode of the first sub-threshold compensation transistor is connected to the control end of the driving module, a second electrode of the first sub-threshold compensation transistor is connected to the first electrode of the second sub-threshold compensation transistor, a second electrode of the second sub-threshold compensation transistor is connected to the first end of the driving module, and a control electrode of the first sub-threshold compensation transistor and a control electrode of the second sub-threshold compensation transistor are both connected to the second scan signal line; Preferably, the storage module comprises a storage capacitor, a first electrode of the storage capacitor is connected to the first power line, and a second electrode of the storage capacitor is connected to the control end of the driving module; Preferably, the first light-emitting control module includes a first light-emitting control transistor, the second light-emitting control module includes a second light-emitting control transistor, a first electrode of the first light-emitting control transistor is connected to the second end of the driving module, a second electrode of the first light-emitting control transistor is connected to the first power line, a first electrode of the second light-emitting control transistor is connected to the first end of the light-emitting module, a second electrode of the second light-emitting control transistor is connected to the first end of the driving module, and a control electrode of the first light-emitting control transistor and a control electrode of the second light-emitting control transistor are both connected to the light-emitting control signal line; Preferably, the driving module comprises a driving transistor, a first electrode of the driving transistor constitutes a first end of the driving module, a second electrode of the driving transistor constitutes a second end of the driving module, and a control electrode of the driving transistor constitutes a control end of the driving module; Preferably, the light emitting module comprises an organic light emitting diode, a first electrode of the organic light emitting diode is connected to a first electrode of the driving transistor, and a second electrode of the organic light emitting diode is connected to the second power line.

7. A display device, characterized in that: It comprises a display panel and an under-screen light source, wherein the under-screen light source is located on the backlight side of the display panel, and at least a part of the display area of ​​the display panel is located within the illumination range of the under-screen light source; The pixel circuit according to any one of claims 1 to 6 is provided in at least a region of the display area illuminated by the under-screen light source.

8. The display device according to claim 7, characterized in that: The pixel circuits are disposed in all display areas of the display panel.

9. The display device according to claim 7, characterized in that: The under-screen light source is used to emit incident light to the object to be identified on the light-emitting side of the display panel, so that at least part of the incident light is reflected by the surface of the object to be identified to form reflected light; the display device also includes a biometric identification component, which includes: A detection sensor, used for receiving the reflected light to detect the biometric features of the object to be identified; A biometric identification device for performing biometric identification based on detected biometrics; Preferably, the under-screen light source is an infrared light source, and the detection sensor is an infrared camera.

10. The display device according to claim 7, characterized in that: The display device is a full-screen display device.

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