Pixel compensation circuit, driving method thereof, display panel and display device

Abstract

Embodiments of the present application provide a pixel compensation circuit, a driving method thereof, a display panel and a display device. The pixel compensation circuit comprises a data writing unit connected to a data signal end; a threshold voltage detection unit connected to the data writing unit; a light emitting control unit connected to a control node; a light emitting device connected to the light emitting control unit and a first power supply end; and a driving unit connected to a second power supply end, the threshold voltage detection unit and the control node. The level of the second power supply end is opposite to that of the first power supply end. The driving unit has a first control electrode and a second control electrode. The first control electrode is used to control the conduction or isolation between the second power supply end and the control node. The second control electrode is used to compensate the threshold voltage of the driving unit. The technical solution of the embodiments of the present application can adjust and control the threshold voltage of the driving unit by using the second control electrode of the driving unit, so that the threshold voltage of the driving unit is more uniform, thereby ensuring the stability of the display brightness gray scale.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a pixel compensation circuit, a driving method thereof, a display panel and a display device. BACKGROUND

[0002] An organic light emitting diode (OLED) display panel has advantages of low energy consumption, self-luminous, etc., and is one of the hotspots in the field of panel display panel research. In the related art, a driving transistor is usually used to generate a driving current to drive the OLED to emit light. However, due to process and device aging, etc., the threshold voltage Vth of the driving transistor is uneven, which changes the driving current and causes uneven display brightness, thereby affecting the display effect. SUMMARY

[0003] Embodiments of the present application provide a pixel compensation circuit, a driving method thereof, a display panel and a display device, to solve or alleviate one or more technical problems in the prior art.

[0004] As an aspect of the embodiments of the present application, a pixel compensation circuit is provided, comprising: a data writing unit connected to a data signal end; a threshold voltage detection unit connected to the data writing unit; a light emitting control unit connected to a control node; a light emitting device connected to the light emitting control unit and a first power supply end; and a driving unit connected to a second power supply end, the threshold voltage detection unit and the control node, the levels of the second power supply end and the first power supply end being opposite, the driving unit having a first control electrode and a second control electrode, the first control electrode being used to control conduction or isolation between the second power supply end and the control node, and the second control electrode being used to compensate for the threshold voltage of the driving unit.

[0005] In an embodiment, the driving unit comprises a driving transistor, the driving transistor comprising the first control electrode and the second control electrode, the first control electrode being connected to the threshold voltage detection unit, and the second control electrode being used to compensate for the threshold voltage of the driving transistor, a first electrode of the driving transistor being connected to the second power supply end, and a second electrode of the driving transistor being connected to the control node.

[0006] In an embodiment, the threshold voltage detection unit comprises a storage capacitor, a first electrode of the storage capacitor being connected to the control node, and a second electrode of the storage capacitor being connected to the first control electrode of the driving transistor.

[0007] In one embodiment, the threshold voltage detection unit comprises: a storage capacitor, a first electrode of the storage capacitor is connected to the second power terminal, and the first electrode of the storage capacitor is independent of the driving transistor, a second electrode of the storage capacitor is connected to the first control electrode of the driving transistor; a detection transistor, a control electrode of the detection transistor is used for receiving a first control signal, a first electrode of the detection transistor is connected to the first control electrode of the driving transistor, and a second electrode of the detection transistor is connected to the control node.

[0008] In one embodiment, the data writing unit comprises: a writing transistor, a control electrode of the writing transistor is used for receiving a second control signal, a first electrode of the writing transistor is connected to the data signal terminal, and a second electrode of the writing transistor is connected to the first control electrode of the driving unit.

[0009] In one embodiment, the light emitting control unit comprises: a light emitting control transistor, a control electrode of the light emitting control transistor is used for receiving a third control signal, a first electrode of the light emitting control transistor is connected to the control node, and a second electrode of the light emitting control transistor is connected to the light emitting device.

[0010] In one embodiment, the display panel further comprises: a reading control unit connected to the control node and the voltage reading unit.

[0011] In one embodiment, the reading control unit comprises: a reading control transistor, a control electrode of the reading control transistor is used for receiving a fourth control signal, a first electrode of the reading control transistor is connected to the control node, and a second electrode of the reading control transistor is connected to the voltage reading unit.

[0012] As another aspect of the embodiments of the present application, the embodiments of the present application provide a display panel comprising the pixel compensation circuit of any of the above embodiments.

[0013] As still another aspect of the embodiments of the present application, the embodiments of the present application provide a display device comprising the display panel of any of the above embodiments.

[0014] As yet another aspect of the embodiments of the present application, the embodiments of the present application provide a driving method of a pixel compensation circuit, applied to the pixel compensation circuit of any of the above embodiments, and the driving method comprises: in a threshold compensation stage, obtaining a threshold voltage offset of the driving unit, so that the second control electrode of the driving unit compensates the threshold voltage of the driving unit according to the threshold voltage offset; and in a light emitting stage, the light emitting control unit controls the driving unit and the light emitting device to be turned on, so that the driving unit drives the light emitting device to emit light.

[0015] In one embodiment, the threshold compensation stage includes: a detection stage, in which the threshold voltage detection unit controls the voltage of the first control electrode of the driving unit to be the sum of the voltage of the second power supply terminal and the threshold voltage of the driving unit, thereby obtaining a threshold voltage offset; and a writing stage, in which the data writing unit controls the data signal terminal and the first control electrode of the driving unit to be turned on, and the data signal terminal and the threshold voltage detection unit to be turned on, and the second control electrode of the driving unit compensates the threshold voltage of the driving unit according to the threshold voltage offset.

[0016] The embodiments of this application employ the above-described technical solution, which utilizes the second control electrode of the driving unit to regulate the threshold voltage of the driving unit, thereby achieving external compensation. This makes the threshold voltage of the driving unit more uniform, resulting in a more stable driving current, ensuring stable grayscale display brightness, and ultimately improving the display effect.

[0017] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of this application will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0018] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0019] Figure 1 and Figure 2 A schematic diagram of a pixel compensation circuit according to an embodiment of this application is shown;

[0020] Figure 3 This diagram illustrates the control capability of the second control electrode over the driving transistor when the driving transistor is an NMOS transistor.

[0021] Figure 4 This diagram illustrates the control capability of the second control electrode over the driving transistor when the driving transistor is a PMOS transistor.

[0022] Figure 5 Show Figure 1 The signal timing diagram of the pixel compensation circuit shown in the figure;

[0023] Figure 6 Show Figure 2 The signal timing diagram of the pixel compensation circuit shown in the figure;

[0024] Figure 7 and Figure 8A schematic diagram of a pixel compensation circuit according to another embodiment of this application is shown;

[0025] Figure 9 Show Figure 7 The signal timing diagram of the pixel compensation circuit shown in the figure;

[0026] Figure 10 Show Figure 8 The signal timing diagram of the pixel compensation circuit shown in the figure;

[0027] Figure 11 A schematic diagram showing a driving method for a pixel compensation circuit according to an embodiment of this application is provided.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100: Pixel compensation circuit;

[0030] 110: Data writing unit; 120: Threshold voltage detection unit; 130: Light emission control unit; 140: Light emission device; 150: Driving unit; 151: Second control electrode; 160: Reading control unit. Detailed Implementation

[0031] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0032] The following is combined with Figures 1-10 A pixel compensation circuit according to an embodiment of the first aspect of this application is described.

[0033] Figure 1 and Figure 2 A schematic diagram of a pixel compensation circuit 100 according to an embodiment of this application is shown. Figure 1 and Figure 2 As shown, the pixel compensation circuit 100 includes: a data writing unit 110, a threshold voltage detection unit 120, a light-emitting control unit 130, a light-emitting device 140, and a driving unit 150.

[0034] Specifically, the data writing unit 110 is connected to the data signal terminal. The threshold voltage detection unit 120 is connected to the data writing unit 110. The light-emitting control unit 130 is connected to the control node N. The light-emitting device 140 is connected to the light-emitting control unit 130 and the first power supply terminal. The driving unit 150 is connected to the second power supply terminal, the threshold voltage detection unit 120, and the control node N. The driving unit 150 has a first control electrode and a second control electrode 151. The first control electrode is used to control the conduction or disconnection between the second power supply terminal and the control node N, and the second control electrode 151 is used to compensate for the threshold voltage of the driving unit 150.

[0035] For example, the data writing unit 110 can control the connection or disconnection of the data signal terminal data and the first control electrode of the driving unit 150, and control the connection or disconnection of the data signal terminal data and the threshold voltage detection unit 120.

[0036] For example, the threshold voltage detection unit 120 can control the voltage of the first control electrode of the driving unit 150 to be the sum of the voltage of the second power supply terminal and the actual threshold voltage of the driving unit 150. By acquiring the voltage of the first control electrode of the driving unit 150, the actual threshold voltage of the driving unit 150 can be obtained. By comparing the actual threshold voltage of the driving unit 150 with the target threshold voltage of the driving unit 150, the threshold voltage offset of the driving unit 150 can be determined. The second control electrode 151 of the driving unit 150 can compensate the actual threshold voltage of the driving unit 150 in real time according to the threshold voltage offset, so that the difference between the actual threshold voltage and the target threshold voltage of the driving unit 150 can be kept within a preset difference range. This can make the threshold voltage of the driving unit 150 more uniform, thereby making the driving current more stable, ensuring the stability of the display brightness grayscale, and thus improving the display effect.

[0037] In this embodiment, the voltage levels of the first power supply terminal and the second power supply terminal are opposite. For example, the second power supply terminal may be a high-level terminal (VDD) and the first power supply terminal may be a low-level terminal (VSS); or the first power supply terminal may be a high-level terminal (VDD) and the second power supply terminal may be a low-level terminal (VSS). For instance, the voltage of the high-level terminal (VDD) may be positive, and the voltage of the low-level terminal (VSS) may be ground or negative.

[0038] The light-emitting device 140 may have a turn-on voltage. When the voltage difference between the first and second electrodes of the light-emitting device 140 is greater than or equal to the turn-on voltage, the light-emitting device 140 emits light. For example, the light-emitting device 140 may include an electroluminescent diode. The anode of the electroluminescent diode may serve as the first electrode of the light-emitting device 140, and the cathode of the electroluminescent diode may serve as the second electrode of the light-emitting device 140. Specifically, for example, the electroluminescent diode may include an OLED or a quantum dot light-emitting diode (QLED).

[0039] During the light-emitting phase, the light-emitting control unit 130 can control the driving unit 150 to conduct with the light-emitting device 140, so that the driving current generated by the driving unit 150 can drive the light-emitting device 140 to emit light. For example, the display panel can be provided with a display area and a border area located around the display area, and the light-emitting device 140 can be disposed in the display area so that the display panel can display an image.

[0040] According to the pixel compensation circuit 100 of the present application embodiment, the threshold voltage of the driving unit 150 can be controlled by the second control electrode 151 of the driving unit 150 to achieve external compensation. This can make the threshold voltage of the driving unit 150 more uniform, thereby making the driving current more stable, ensuring the stability of the display brightness grayscale, and thus improving the display effect. Moreover, the pixel compensation circuit 100 has a simple structure, fast driving speed, and large compensation range.

[0041] In one implementation, such as Figure 1 As shown, the driving unit 150 includes a driving transistor T1, which includes a first control electrode and a second control electrode 151. The first control electrode is connected to the threshold voltage detection unit 120, and the second control electrode 151 is used to compensate for the threshold voltage of the driving transistor T1. The first electrode of the driving transistor T1 is connected to the second power supply terminal, and the second electrode of the driving transistor T1 is connected to the control node N. Both the first and second control electrodes 151 can be the gate of the driving transistor T1. For example, the first control electrode can be the top gate of the driving transistor T1, and the second control electrode 151 can be the bottom gate of the driving transistor T1. One of the first and second electrodes of the driving transistor T1 is the source, and the other is the drain.

[0042] Figure 3 This diagram illustrates the control capability of the second control electrode 151 over the driving transistor T1 when T1 is an NMOS transistor. Figure 3 (a) is a graph showing the relationship between the voltage LS of the second control electrode 151 and the on-current Ion of the driving transistor T1. Figure 3(b) is a graph showing the relationship between the voltage LS of the second control electrode 151 and the threshold voltage Vth of the driving transistor T1. Figure 3 (c) is a graph showing the relationship between the voltage LS of the second control electrode 151 and the on-state current Ion of the driving transistor T1. Figure 3 (a)- Figure 3 (c) It can be seen that as the voltage LS of the second control electrode 151 changes from negative to positive, the threshold voltage Vth of the driving transistor T1 gradually becomes negatively biased, the conduction current Ion of the driving transistor T1 gradually increases, and the driving transistor T1 becomes easier to conduct.

[0043] Figure 4 This diagram illustrates the control capability of the second control electrode 151 on the driving transistor T1 when T1 is a PMOS transistor. Figure 4 (a) is a graph showing the relationship between the voltage LS of the second control electrode 151 and the on-current Ion of the driving transistor T1. Figure 4 (b) is a graph showing the relationship between the voltage LS of the second control electrode 151 and the threshold voltage Vth of the driving transistor T1. Figure 4 (c) is a graph showing the relationship between the voltage LS of the second control electrode 151 and the on-state current Ion of the driving transistor T1. Figure 4 (a)- Figure 4 (c) It can be seen that as the voltage LS of the second control electrode 151 changes from negative to positive, the threshold voltage Vth of the driving transistor T1 gradually becomes negatively biased, the on-current Ion of the driving transistor T1 gradually decreases, and the driving transistor T1 becomes more difficult to turn on. Figure 3 and Figure 4 It can be seen that the second control electrode 151 of the driving transistor T1 can adjust the threshold voltage Vth of the driving transistor T1 by about 8V.

[0044] For example, firstly, the data writing unit 110 can control the data signal terminal 'data' and the first control electrode of the driving transistor T1 to be turned on, and control the data signal terminal 'data' and the threshold voltage detection unit 120 to be turned on. Under the action of the data signal terminal 'data', the driving transistor T1 is turned on. At this time, the light-emitting control unit 130 can control the driving transistor T1 to be isolated from the light-emitting device 140. The signal from the second power supply terminal can flow into the threshold voltage detection unit 120 after passing through the driving transistor T1. Under the action of the threshold voltage detection unit 120, the voltage of the first control electrode of the driving transistor T1 changes. When the voltage of the first control electrode is equal to the sum of the voltage of the second power supply terminal and the actual threshold voltage of the driving transistor T1, the actual threshold voltage of the driving unit 150 can be obtained, and the threshold voltage offset of the driving transistor T1 can be determined. Then, the signal input of the second control electrode 151 of the driving transistor T1 compensates the actual threshold voltage of the driving transistor T1 in real time, so that the difference between the actual threshold voltage of the driving transistor T1 and the target threshold voltage can be kept within a preset difference range.

[0045] In one implementation, such as Figure 1 and Figure 2 As shown, the threshold voltage detection unit 120 includes a storage capacitor Cst. The first terminal of the storage capacitor Cst is connected to the control node, and the second terminal of the storage capacitor Cst is connected to the first control terminal of the driving transistor T1. For example, after the data writing unit 110 controls the data signal terminal data and the first control terminal of the driving transistor T1 to be turned on, the signal of the data signal terminal data is written to the second terminal of the storage capacitor Cst. Under the action of the data signal terminal data, the driving transistor T1 is turned on. The signal of the second power supply terminal can be input to the first terminal of the storage capacitor Cst after flowing through the driving transistor T1. At this time, the storage capacitor Cst is connected in series with the driving transistor T1, causing the voltage of the first control terminal of the driving transistor T1 to change. When the voltage of the first control terminal is equal to the sum of the voltage of the second power supply terminal and the actual threshold voltage of the driving transistor T1, the actual threshold voltage of the driving unit 150 can be obtained, and the threshold voltage offset of the driving transistor T1 can be determined. Then, the signal input of the second control terminal 151 of the driving transistor T1 compensates the actual threshold voltage of the driving transistor T1 in real time, so that the difference between the actual threshold voltage of the driving transistor T1 and the target threshold voltage can be kept within a preset difference range.

[0046] In this embodiment, the actual threshold voltage of the driving transistor T1 can be obtained by connecting the storage capacitor in series with the driving transistor T1, thereby obtaining the threshold voltage offset of the driving transistor T1. Then, the threshold voltage of the driving unit 150 can be compensated by the second control electrode 151 of the driving transistor T1 to ensure the display effect of the display panel.

[0047] Of course, this application is not limited to this, for example, Figure 7 and Figure 8 A schematic diagram of a pixel compensation circuit 100 according to another embodiment of this application is shown. In another embodiment, such as Figure 7 and Figure 8 As shown, the threshold voltage detection unit 120 includes a storage capacitor Cst and a detection transistor T2. The first terminal of the storage capacitor Cst is independent of the driving transistor T1, that is, the first terminal of the storage capacitor Cst is not connected to the driving transistor T1, and the second terminal of the storage capacitor Cst is connected to the first control terminal of the driving transistor T1. The control terminal of the detection transistor T2 is used to receive a first control signal, the first terminal of the detection transistor T2 is connected to the first control terminal of the driving transistor T1, and the second terminal of the detection transistor T2 is connected to the control node N.

[0048] For example, after the data writing unit 110 controls the data signal terminal 'data' and the first control electrode of the driving transistor T1 to be turned on, the signal from the data signal terminal 'data' is written to the second electrode of the storage capacitor Cst. Under the action of the data signal terminal 'data', the driving transistor T1 is turned on. Under the control of the first control signal, the detection transistor T2 is turned on. The signal from the second power supply terminal can flow sequentially through the driving transistor T1 and the detection transistor T2. At this time, the detection transistor T2 is connected in series with the driving transistor T1. When the voltage of the first control electrode is equal to the sum of the voltage of the second power supply terminal and the actual threshold voltage of the driving transistor T1, the actual threshold voltage of the driving unit 150 can be obtained, and thus the threshold voltage offset of the driving transistor T1 can be determined. Then, the signal input from the second control electrode 151 of the driving transistor T1 compensates the actual threshold voltage of the driving transistor T1 in real time, so that the difference between the actual threshold voltage of the driving transistor T1 and the target threshold voltage can be kept within a preset difference range.

[0049] The method for obtaining the actual threshold voltage of the driving transistor T1 in this embodiment differs from that in the previous embodiment. In this embodiment, the actual threshold voltage of the driving transistor T1 can be obtained by connecting the detection transistor T2 and the driving transistor T1 in series, thereby obtaining the threshold voltage offset of the driving transistor T1. Then, the second control electrode 151 of the driving transistor T1 is used to compensate the threshold voltage of the driving unit 150 to ensure the display effect of the display panel.

[0050] In one embodiment, the data writing unit 110 includes a writing transistor T3, the control electrode of which is used to receive a second control signal, the first electrode of which is connected to a data signal terminal (data), and the second electrode of which is connected to the first control electrode of the driving unit 150. For example, when the second control signal controls the writing transistor T3 to be turned on, the data signal terminal (data) is connected to the first control electrode of the driving transistor T1 and to the second electrode of the storage capacitor Cst. When the second control signal controls the writing transistor T3 to be turned off, the data signal terminal (data) is disconnected from the first control electrode of the driving transistor T1 and from the second electrode of the storage capacitor Cst.

[0051] Therefore, by setting the write transistor T3 as described above, the conduction and isolation between the data signal terminal data and the first control electrode of the drive unit 150, as well as the conduction and isolation between the data signal terminal data and the threshold voltage detection unit 120, can be controlled by the conduction or isolation state of the write transistor T3, thereby controlling whether data is written to the data signal terminal data.

[0052] In one implementation, such as Figure 1 and Figure 7 As shown, the light-emitting control unit 130 includes a light-emitting control transistor T4. The control electrode of the light-emitting control transistor T4 is used to receive a third control signal. The first electrode of the light-emitting control transistor T4 is connected to the control node N, and the second electrode of the light-emitting control transistor T4 is connected to the light-emitting device 140. Thus, during the light-emitting phase, the third control signal can control the light-emitting control transistor T4 to conduct. At this time, the driving unit 150 and the light-emitting device 140 are connected, so that the driving current generated by the driving unit 150 drives the light-emitting device 140 to emit light, realizing the display of the display panel. During the non-light-emitting phase, the third control signal can control the light-emitting control transistor T4 to turn off. At this time, the driving unit 150 and the light-emitting device 140 are isolated, and the current generated by the driving unit 150 cannot be input to the light-emitting device 140, so the light-emitting device 140 is in a non-light-emitting state.

[0053] In one embodiment, the pixel compensation circuit 100 may further include a read control unit 160, which is connected to the control node N and the voltage read unit.

[0054] For example, when both the write transistor T3 and the light-emitting control transistor T4 are in the off state, the storage capacitor Cst is connected in series with the drive transistor T1 (e.g. Figure 1 (as shown) or the detection transistor T2 is connected in series with the driving transistor T1 (e.g.) Figure 7As shown in the diagram, at this time, the voltage at control node N is equal to the voltage of the first control electrode of driving transistor T1, and both are the sum of the voltage at the second power supply terminal and the actual threshold voltage of driving unit 150. The read control unit 160 can control the voltage read unit and control node N to be turned on, allowing the voltage read unit to read the voltage of control node N. Based on the voltage of control node N, the threshold voltage offset of driving transistor T1 can be obtained.

[0055] Furthermore, the read control unit 160 may include a read control transistor T5. The control terminal of the read control transistor T5 is used to receive a fourth control signal. The first terminal of the read control transistor T5 is connected to the control node N, and the second terminal of the read control transistor T5 is connected to the voltage read unit. In this way, under the control of the fourth control signal, the voltage read unit and the control node N can be turned on or off.

[0056] For example, the voltage reading unit can be an analog-to-digital converter (ADC).

[0057] In this embodiment, by setting the read control unit 160, the voltage read unit can read the voltage of the control node N, thereby determining the threshold voltage offset of the drive unit 150, so that the second control electrode 151 of the drive unit 150 can compensate the threshold voltage based on the threshold voltage offset.

[0058] The display panel according to the second aspect of the present application includes a pixel compensation circuit 100 according to any embodiment of the first aspect of the present application.

[0059] For example, the display area of ​​a display panel may include multiple pixel units, and each pixel unit may include multiple sub-pixels. For instance, a pixel unit may include red sub-pixels, green sub-pixels, and blue sub-pixels, allowing the display panel to use a red-green-blue color mixing principle for image display. Of course, in practical applications, the sub-pixels of a pixel unit can be specifically determined according to the actual application environment to better meet the needs of the application.

[0060] According to the display panel of the embodiment of this application, by adopting the pixel compensation circuit 100 described above, the threshold voltage of the driving unit 150 can be controlled by the second control electrode 151 of the driving unit 150 to achieve external compensation, which can make the threshold voltage of the driving unit 150 more uniform, thereby making the driving current more stable, ensuring the stability of the display brightness grayscale, and thus improving the display effect.

[0061] The display device according to the third aspect of this application includes a display panel according to any embodiment of the second aspect of this application.

[0062] For example, the display device can be any product or component with display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator.

[0063] The driving method of the pixel compensation circuit 100 according to the fourth aspect embodiment of this application is applied to the pixel compensation circuit 100 in any of the above embodiments. Figure 11 A schematic diagram showing a driving method for a pixel compensation circuit 100 according to an embodiment of this application is shown, as follows: Figure 11 As shown, the driving method includes:

[0064] Step S901: In the threshold compensation stage, the threshold voltage offset of the driving unit 150 is obtained so that the second control electrode 151 of the driving unit 150 compensates the threshold voltage of the driving unit 150 according to the threshold voltage offset. This makes the threshold voltage of the driving unit 150 more uniform, thereby making the driving current more stable, ensuring the stability of the display brightness grayscale, and thus improving the display effect.

[0065] Step S902: During the light-emitting stage, the light-emitting control unit 130 controls the driving unit 150 and the light-emitting device 140 to be turned on, so that the driving unit 150 drives the light-emitting device 140 to emit light.

[0066] According to the driving method of the pixel compensation circuit 100 in the embodiment of this application, the threshold voltage of the driving unit 150 can be adjusted by the second control electrode 151 of the driving unit 150 to achieve external compensation, which can make the threshold voltage of the driving unit 150 more uniform, thereby making the driving current more stable, ensuring the stability of the display brightness grayscale, and thus improving the display effect.

[0067] In one embodiment, the threshold compensation stage includes a detection stage and a writing stage. During the detection stage, the threshold voltage detection unit 120 controls the voltage of the first control electrode of the driving unit 150 to be the sum of the voltage of the second power supply terminal and the threshold voltage of the driving unit 150, thus obtaining a threshold voltage offset. During the writing stage, the data writing unit 110 controls the data signal terminal (data) and the first control electrode of the driving unit 150 to be turned on, and the data signal terminal (data) and the threshold voltage detection unit 120 to be turned on, and the second control electrode 151 of the driving unit 150 compensates for the threshold voltage of the driving unit 150 according to the threshold voltage offset.

[0068] Figure 5 Show Figure 1 The signal timing diagram of the pixel compensation circuit 100 shown in the figure; Figure 6 Show Figure 2 The signal timing diagram of the pixel compensation circuit 100 shown is as follows. Figure 1 , Figure 2 , Figure 5 andFigure 6 As shown, the threshold compensation stage may also include a data writing stage. The signal timing of the pixel compensation circuit 100 may sequentially include a data writing stage A1, a detection stage B1, a writing stage C1, a detection stage D1, a data writing stage E1, and a light emission stage F1.

[0069] Specifically, in the data writing stage A1, the write transistor T3 is turned on, while the light-emitting control transistor T4 and the read control transistor T5 are turned off. The data signal at the data terminal is written to the storage capacitor Cst. In the detection stage B1, the read control transistor T5 is turned on, while the write transistor T3 and the light-emitting control transistor T4 are turned off. The voltage of control node N is equal to the voltage of the first control node N, which is the sum of the voltage at the second power supply terminal and the threshold voltage of the driving transistor T1, thus obtaining the threshold voltage offset. Based on the correspondence between the preset voltage offset and the voltage value of the second control electrode 151 of the driving transistor T1, the voltage value of the second control electrode 151 corresponding to the threshold voltage offset can be obtained. In the writing stage C1, the write transistor T3 is turned on, while the light-emitting control transistor T4 and the read control transistor T5 are turned off. The data signal at the data terminal and the signal at the second control electrode 151 are input. In the detection stage D1, the read control transistor T5 is turned on, while the write transistor T3 and the light-emitting control transistor T4 are turned off. The threshold voltage offset is reacquired, provided that the difference between the actual threshold voltage of the driving transistor T1 and the target threshold voltage remains within the preset difference range. During the data writing phase E1, the write transistor T3 is turned on, while the light-emitting control transistor T4 and the read control transistor T5 are turned off. The data signal at the data terminal is written to the storage capacitor Cst. At this time, the signal at the second control electrode 151 remains input to compensate for the threshold voltage of the driving unit 150. During the light-emitting phase F1, the light-emitting control transistor T4 is turned on, while the write transistor T3 and the read control transistor T5 are turned off. The driving transistor T1 drives the light-emitting device 140 to emit light.

[0070] exist Figure 5 In the signal timing diagram, the write transistor T3, the light-emitting control transistor T4, and the read transistor are all PMOS transistors; Figure 6 In the signal timing diagram, the write transistor T3, the light-emitting control transistor T4, and the read transistor are all NMOS transistors.

[0071] Figure 9 Show Figure 7 The signal timing diagram of the pixel compensation circuit 100 shown in the figure; Figure 10 Show Figure 8 The signal timing diagram of the pixel compensation circuit 100 shown is as follows. Figures 7-10As shown, the threshold compensation stage may further include a data writing stage. The detection stage may include a first detection stage and a second detection stage. In the first detection stage, the threshold voltage detection unit 120 controls the voltage of the first control electrode of the driving unit 150 to be the sum of the voltage of the second power supply terminal and the threshold voltage of the driving unit 150. In the second detection stage, the threshold voltage offset is obtained. The signal timing of the pixel compensation circuit 100 may sequentially include a data writing stage A2, a first detection stage B2, a second detection stage C2, a writing stage D2, a first detection stage E2, a second detection stage F2, a data writing stage G2, and a light emission stage H2.

[0072] Specifically, in the data writing stage A2, the write transistor T3 is turned on, while the light-emitting control transistor T4, the read control transistor T5, and the detection transistor T2 are turned off. The data signal at the data terminal is written to the storage capacitor Cst. In the first detection stage B2, the detection transistor T2 is turned on, while the write transistor T3, the light-emitting control transistor T4, and the read control transistor T5 are turned off. The voltage of control node N is equal to the voltage of the first control node N, which is the sum of the voltage at the second power supply terminal and the threshold voltage of the driving transistor T1. In the second detection stage C2, the detection transistor T2 and the read control transistor T5 are turned on, while the write transistor T3 and the light-emitting control transistor T4 are turned off. The voltage at control node N is subtracted from the voltage at the second power supply terminal to obtain the threshold voltage, which in turn yields the threshold voltage offset. Based on the preset voltage offset and the correspondence between the voltage values ​​at the second control electrode 151 of the driving transistor T1, the voltage value at the second control electrode 151 corresponding to the threshold voltage offset can be obtained. In the write phase D2, write transistor T3 is turned on, while light-emitting control transistor T4, read control transistor T5, and detection transistor T2 are turned off. The data signal at the data terminal and the signal at the second control electrode 151 are input. In the first detection phase E2, detection transistor T2 is turned on, while write transistor T3, light-emitting control transistor T4, and read control transistor T5 are turned off, and the voltage of control node N is restored. In the second detection phase F2, detection transistor T2 and read control transistor T5 are turned on, while write transistor T3 and light-emitting control transistor T4 are turned off, and the threshold voltage offset is restored. The difference between the actual threshold voltage of driving transistor T1 and the target threshold voltage should remain within a preset range. In the data write phase G2, write transistor T3 and detection transistor T2 are turned on, while read control transistor T5 and light-emitting control transistor T4 are turned off. The data signal at the data terminal is written to storage capacitor Cst. At this time, the signal at the second control electrode 151 remains input to compensate for the threshold voltage of driving unit 150. During the light-emitting stage H2, the light-emitting control transistor T4 is turned on, while the write transistor T3, the detection transistor T2, and the read control transistor T5 are turned off, and the drive transistor T1 drives the light-emitting device 140 to emit light.

[0073] exist Figure 9 In the signal timing diagram, the write transistor T3, the detection transistor T2, the light-emitting control transistor T4, and the read transistor are all PMOS transistors; Figure 10 In the signal timing diagram, the write transistor T3, the detection transistor T2, the light-emitting control transistor T4, and the read transistor are all NMOS transistors.

[0074] Other configurations of the pixel compensation circuit 100, display panel, display device, and driving method of the pixel compensation circuit 100 in the above embodiments can be adopted from various technical solutions now and in the future known to those skilled in the art, and will not be described in detail here.

[0075] In the description of this specification, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0076] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0077] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0078] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0079] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0080] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A pixel compensation circuit, characterized in that, include: The data writing unit is connected to the data signal terminal; A threshold voltage detection unit is connected to the data writing unit; The light-emitting control unit is connected to the control node; A light-emitting device is connected to the light-emitting control unit and the first power supply terminal; A driving unit is connected to a second power supply terminal, the threshold voltage detection unit, and the control node. The voltage levels of the second power supply terminal and the first power supply terminal are opposite. The driving unit includes a driving transistor with a first control electrode and a second control electrode. The first control electrode is connected to the threshold voltage detection unit and is used to control the conduction or disconnection of the second power supply terminal and the control node. The second control electrode is used to compensate for the threshold voltage of the driving transistor. The threshold voltage detection unit includes: A storage capacitor, wherein the first terminal of the storage capacitor is used to connect to the second power supply terminal, and the first terminal of the storage capacitor is independent of the driving transistor, and the second terminal of the storage capacitor is connected to the first control terminal of the driving transistor; A detection transistor is provided, wherein the control electrode of the detection transistor is used to receive a first control signal, the first electrode of the detection transistor is connected to the first control electrode of the driving transistor, and the second electrode of the detection transistor is connected to the control node.

2. The pixel compensation circuit according to claim 1, characterized in that, The first terminal of the driving transistor is connected to the second power supply terminal, and the second terminal of the driving transistor is connected to the control node.

3. The pixel compensation circuit according to claim 1 or 2, characterized in that, The data writing unit includes: A write transistor is provided, wherein the control electrode of the write transistor is used to receive a second control signal, the first electrode of the write transistor is used to connect to the data signal terminal, and the second electrode of the write transistor is connected to the first control electrode of the drive unit.

4. The pixel compensation circuit according to claim 1 or 2, characterized in that, The light-emitting control unit includes: A light-emitting control transistor, wherein the control electrode of the light-emitting control transistor is used to receive a third control signal, the first electrode of the light-emitting control transistor is connected to the control node, and the second electrode of the light-emitting control transistor is connected to the light-emitting device.

5. The pixel compensation circuit according to claim 1 or 2, characterized in that, Also includes: The read control unit is connected to the control node and the voltage read unit.

6. The pixel compensation circuit according to claim 5, characterized in that, The reading control unit includes: A read control transistor is provided, the control electrode of which is used to receive a fourth control signal. The first electrode of the read control transistor is connected to the control node, and the second electrode of the read control transistor is connected to the voltage read unit.

7. A display panel, characterized in that, Includes the pixel compensation circuit according to any one of claims 1-6.

8. A display device, characterized in that, Includes the display panel according to claim 7.

9. A driving method for a pixel compensation circuit, characterized in that, The driving method, applied to the pixel compensation circuit as described in any one of claims 1-6, comprises: During the threshold compensation stage, the threshold voltage offset of the driving unit is obtained so that the second control electrode of the driving unit compensates the threshold voltage of the driving unit according to the threshold voltage offset. During the light-emitting phase, the light-emitting control unit controls the driving unit and the light-emitting device to be turned on, so that the driving unit drives the light-emitting device to emit light.

10. The driving method according to claim 9, characterized in that, The threshold compensation stage includes: During the detection phase, the threshold voltage detection unit controls the voltage of the first control electrode of the driving unit to be the sum of the voltage of the second power supply terminal and the threshold voltage of the driving unit, thereby obtaining the threshold voltage offset. During the writing phase, the data writing unit controls the data signal terminal and the first control electrode of the driving unit to be turned on, and the data signal terminal and the threshold voltage detection unit are turned on. The second control electrode of the driving unit compensates for the threshold voltage of the driving unit according to the threshold voltage offset.

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