Pixel circuit, compensation method for pixel circuit and display device
地域：
Anhui
摘要
The present disclosure relates to a pixel circuit, a compensation method and a display device. The pixel circuit includes a first switching circuit for supplying a data voltage to a first node in response to a first scan signal being valid, a second switching circuit for conductively connecting a sensing signal line with a second node in response to a second scan signal being valid, a reset circuit for supplying a reset voltage to the sensing signal line in response to a reset control signal being valid, a light-emitting element, and a driving transistor for enabling, when the light-emitting element emits light, the sensing signal line to be charged in response to the second scan signal being valid and the reset control signal being invalid, the voltage of the sensing signal line is sensed after it was charged so as to compensate the data voltage.
說(shuō)明書(shū)
The present application claims the benefit of Chinese Patent Application No. 201811599465.8, filed on Dec. 26, 2018, the entire disclosure of which is incorporated herein by reference.
The present disclosure relates to the technical field of display, and particularly to a pixel circuit, a compensation method for the pixel circuit and a display device.
Electroluminescent diodes such as Organic Light-emitting Diodes (OLEDs) have advantages such as self-luminescence and low energy consumption, and are one of hotspots in the research field of the application of electroluminescent display panels. An OLED display product controls its illumination for display by controlling the amount of current flowing through the OLEDs. Due to easy-aging characteristics of thin film transistors (TFTs) and OLEDs themselves in a structure of an OLED display product, material properties of OLED devices gradually deteriorate during a long-term display process, which causes the brightness of pixels to decay constantly. Moreover, since sub-pixels of different colors use different OLED luminescent materials, the decay speed of the brightness of the sub-pixels of different colors may also be inconsistent. This causes the white balance of an organic light-emitting display to drift. To this end, an approach of performing aging treatment before the OLED product leaves the factory is employed in a related art. However, this approach will reduce the lifetime of OLED devices, and will increase production time and affect production efficiency of the production line.
權(quán)利要求
The invention claimed is:1. A pixel circuit, comprising:a first switching circuit configured to supply a data voltage on a data input to a first node in response to a first scan signal on a first scan signal terminal being valid, wherein the first scan signal is arranged to be valid during a data writing phase and a charging phase, and to be invalid during a reset phase, a light-emitting phase and a sensing phase; a second switching circuit configured to conductively connect a sensing signal line with a second node in response to a second scan signal on a second scan signal terminal being valid wherein the second scan signal is arranged to be valid during the data writing phase, the reset phase, the light-emitting phase and the sensing phase, and to be invalid during the charging phase; a reset circuit configured to supply a reset voltage on a reset signal terminal to the sensing signal line in response to a reset control signal on a reset control terminal being valid, wherein the reset control signal is arranged to be valid during the data writing phase and the reset phase, and to be invalid during the light-emitting phase and the charging phase; a light-emitting element comprising a first terminal connected to the second node and a second terminal connected to a first voltage terminal; a tank circuit comprising a first terminal connected to the first node and a second terminal connected to the second node and configured to store the data voltage during the charging phase; and a driving transistor comprising a gate connected to the first node, a first electrode connected to the second node and a second electrode connected to a second voltage terminal, wherein the driving transistor is configured to drive the light-emitting element to emit light, wherein the second switching circuit is further configured to input the reset voltage to the second node in response to both the second scan signal and the reset control signal being valid during the reset phase; and the driving transistor is further configured to be turned on under control of the data voltage stored with the tank circuit in response to the first scan signal being invalid, and the second scan signal and the reset control signal being valid during the light-emitting phase, so as to charge the first terminal of the light-emitting element with a second voltage on the second voltage terminal until the light-emitting element is lit, and configured to, when the light-emitting element emits light, enable the sensing signal line to be charged with the second voltage in response to the first scan signal being invalid, the second scan signal being valid and the reset control signal being invalid during the sensing phase, and wherein a voltage of the sensing signal line is sensed after the sensing signal line was charged for compensating the data voltage. 2. The pixel circuit according to claim 1 , wherein the first switching circuit comprises a first switching transistor, the first switching transistor comprising a gate connected to the first scan signal terminal, a first electrode connected to a data signal terminal, and a second electrode connected to the gate of the driving transistor. 3. The pixel circuit according to claim 1 , wherein the second switching circuit comprises a second switching transistor, the second switching transistor comprising a gate connected to the second scan signal terminal, a first electrode connected to an anode of the light-emitting element, and a second electrode connected to the sensing signal line. 4. The pixel circuit according to claim 1 , wherein the reset circuit comprises a reset switch, the reset switch comprising a control terminal connected to the reset control terminal, a first terminal connected to the reset signal terminal, and a second terminal connected to the sensing signal line. 5. The pixel circuit according to claim 1 ,wherein the reset control terminal is connected to a driving chip, and wherein the driving chip is configured to provide the reset control signal to control whether to provide a reset voltage to the sensing signal line. 6. The pixel circuit according to claim 1 , wherein the tank circuit comprises an energy storage capacitor. 7. A compensation method for a pixel circuit, wherein the pixel circuit comprises a first switching circuit configured to supply a data voltage on a data input to a first node in response to a first scan signal on a first scan signal terminal being valid; a second switching circuit configured to conductively connect a sensing signal line with a second node in response to a second scan signal on a second scan signal terminal being valid; a reset circuit configured to supply a reset voltage on a reset signal terminal to the sensing signal line in response to a reset control signal on a reset control terminal being valid; a light-emitting element comprising a first terminal connected to the second node and a second terminal connected to a first voltage terminal; a tank circuit comprising a first terminal connected to the first node and a second terminal connected to the second node; and a driving transistor comprising a gate connected to the first node, a first electrode connected to the second node and a second electrode connected to a second voltage terminal, and configured to supply a current corresponding to the data voltage applied on the gate to the light-emitting element, the compensation method comprising:inputting the data voltage to the gate of the driving transistor and inputting the reset voltage to the second node by making the first scan signal, the second scan signal and the reset control signal be valid in a data writing phase; storing the data voltage with the tank circuit and charging the second node via a second voltage on the second voltage terminal until the light-emitting element emits light, by making the first scan signal remaining valid and the second scan signal become invalid in a charging phase; charging the sensing signal line by making the first scan signal become invalid and controlling the second scan signal and the reset control signal accordingly, and sensing a voltage of the sensing signal line after the sensing signal line is charged in a voltage sensing phase; and compensating the data voltage supplied to a data line based on a sensed voltage in a compensation phase; wherein the voltage sensing phase comprises a reset phase, a light-emitting phase and a sensing phase which are sequentially arranged, wherein in the reset phase, the reset voltage is inputted to the second node so as to re-initialize the second node, by making the second scan signal become valid and the reset control signal become valid; wherein in the light-emitting phase, the driving transistor is turned on with the data voltage stored in the tank circuit to charge the second node with the second voltage until the light-emitting element emits light, by making the second scan signal remain valid and the reset control signal become invalid; and in the sensing phase, the sensing signal line is charged, when the light-emitting element emits light, by making the second scan signal remain valid and the reset control signal remain invalid. 8. The method according to claim 7 , wherein the first switching circuit further comprises a first switching transistor, the first switching transistor comprising a gate connected to the first scan signal terminal, a first electrode connected to a data signal terminal, and a second electrode connected to the gate of the driving transistor, and wherein the data writing phase comprises:applying a first level signal on the first scan signal terminal to control the first switching transistor to turn on, and applying a data signal on the data signal terminal to input the data signal to the gate of the driving transistor. 9. The method according to claim 8 , wherein the second switching circuit further comprises a second switching transistor, the second switching transistor comprising a gate connected to the second scan signal terminal, a first electrode connected to the second node, and a second electrode connected to the sensing signal line, and wherein the data writing phase comprises:applying a first level signal on the second scan signal terminal to control the second switching transistor to turn on; and applying a reset voltage on the sensing signal line to input the reset voltage to the second node. 10. The method according to claim 9 , wherein the data writing phase comprises:applying the first level signal on the second scan signal terminal to control the second switching transistor to turn on; and applying the reset voltage on the sensing signal line to input the reset voltage to the second node, before the data signal is inputted to the gate of the driving transistor. 11. The method according to claim 9 , wherein the data writing phase comprises:applying a first level signal on the second scan signal terminal to control the second switching transistor to turn on; and applying the reset voltage on the sensing signal line to input the reset voltage to the second node, while inputting the data signal to the gate of the driving transistor. 12. The method according to claim 9 , wherein the charging phase comprises:applying a second level signal to the second scan signal terminal to control the second switching transistor to turn off, after the reset voltage is input to the second node. 13. The method according to claim 9 , wherein the tank circuit comprises an energy storage capacitor, and wherein the charging phase further comprises:storing a voltage between the gate and the second electrode of the driving transistor with the energy storage capacitor, after the reset voltage is inputted to the second node. 14. The method according to claim 9 , wherein the voltage sensing phase comprises:applying a second level signal on the first scan signal terminal to control the first switching transistor to turn off; controlling the driving transistor to turn on with a voltage stored with an energy storage capacitor to charge the second node until the light-emitting element emits light; applying a first level signal on the second scan signal terminal to control the second switching transistor to turn on to charge the sensing signal line through the second switching transistor; and sensing the voltage of the sensing signal line after the sensing signal line is charged through the sensing signal line. 15. The method according to claim 7 , wherein the compensating comprises:determining a corresponding data voltage variation based on a sensed voltage; compensating a data voltage corresponding to a to-be-written data signal according to a determined data voltage variation; and supplying a compensated data voltage at a data signal terminal in a corresponding data writing phase. 16. A display device, comprising:a scan driver configured to sequentially supply a first scan signal to a plurality of first scan lines and sequentially supply a second scan signal to a plurality of second scan lines wherein the first scan signal is arranged to be valid during a data writing phase and a charging phase and to be invalid during a reset phase, a light-emitting phase and a sensing phase, and the second scan signal is arranged to be valid during the data writing phase, the reset phase, the light-emitting phase and the sensing phase and to be invalid during the charging phase; a data driver configured to generate a data voltage based on input data and supply a generated data voltage to a plurality of data lines and further configured to supply a reset control signal to a reset control line, wherein the reset control signal is arranged to be valid during the data writing phase and the reset phase and to be invalid during the light-emitting phase and the charging phase; a pixel array comprising a plurality of pixel circuits arranged in an array, each pixel circuit comprising:a first switching circuit connected to a first scan line, a data line and a first node, and configured to supply a data voltage on the data line to the first node in response to a first scan signal on the first scan line being valid; a second switching circuit connected to a second scan line, a second node and a sensing signal line, and configured to conductively connect the sensing signal line with the second node in response to a second scan signal on the second scan line being valid; a reset circuit connected to a reset control line, a reset voltage terminal and the sensing signal line, and configured to supply a reset voltage at the reset voltage terminal to the sensing signal line in response to a reset control signal on the reset control line being valid; a light-emitting element comprising a first terminal connected to the second node and a second terminal connected to a first voltage terminal; a tank circuit comprising a first terminal connected to the first node and a second terminal connected to the second node and configured to store the data voltage during the charging phase; and a driving transistor comprising a gate connected to the first node, a first electrode connected to the second node and a second electrode connected to a second voltage terminal, wherein the driving transistor is configured to supply a current corresponding to a data voltage input on the gate to the light-emitting element, wherein the second switching circuit is further configured to input the reset voltage to the second node in response to both the second scan signal and the reset control signal being valid; and the driving transistor is further configured to be turned on under control of the data voltage stored with the tank circuit in response to the first scan signal being invalid, and the second scan signal and the reset control signal being valid during the light-emitting phase, so as to charge the first terminal of the light-emitting element with a second voltage on the second voltage terminal until the light-emitting element is lit, and configured to, when the light-emitting element emits light, enable the sensing signal line to be charged with the second voltage in response to the first scan signal being invalid, the second scan signal being valid and the reset control signal being invalid during the sensing phase, and wherein the data driver is further configured to obtain a sensed voltage of the sensing signal line after the sensing signal line charged, and compensate a data voltage supplied to the data line based on a sensed voltage. 17. The display device according to claim 16 , wherein the first switching circuit comprises a first switching transistor, the first switching transistor comprising a gate connected to a first scan signal terminal, a first electrode connected to a data signal terminal, and a second electrode connected to the gate of the driving transistor. 18. The display device according to claim 16 , wherein the second switching circuit comprises a second switching transistor, the second switching transistor comprising a gate connected to a second scan signal terminal, a first electrode connected to an anode of the light-emitting element, and a second electrode connected to the sensing signal line. 19. The display device according to claim 16 , wherein the reset circuit comprises a reset switch comprising a control terminal connected to a reset control terminal, a first terminal connected to a reset signal terminal, and a second terminal connected to the sensing signal line.
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