Pixel driving circuit and method for driving the same, display panel and compensation

Patent metadata

Field	Value
Publication number	US-10762844-B2
Application number	US-201816096796-A
Country	US
Kind code	B2
Filing date	Jan 17, 2018
Priority date	Jun 9, 2017
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

The present application provides a pixel driving circuit, including a driving sub-circuit, a compensation sub-circuit, a first switching sub-circuit, and a second switching sub-circuit. The driving sub-circuit has a control terminal electrically connected to a first terminal of the second switching sub-circuit, a first terminal electrically connected to a light-emitting element, and a second terminal electrically connected to a power source; the compensation sub-circuit has a first terminal electrically connected to the first terminal of the driving sub-circuit, and a second terminal electrically connected to the control terminal of the driving sub-circuit; the first switching sub-circuit has a control terminal electrically connected to a first signal input terminal, a first terminal electrically connected to the first terminal of the driving sub-circuit, and a second terminal electrically connected to an initial voltage input terminal; and the second switching sub-circuit has a control terminal electrically connected to a second signal input terminal, a first terminal electrically connected to the control terminal of the driving sub-circuit, and a second terminal electrically connected to a data signal input terminal.

First claim

We claim:

1. A pixel driving circuit, comprising a driving sub-circuit, a compensation sub-circuit, a first switching sub-circuit, and a second switching sub-circuit, wherein
the driving sub-circuit has a control terminal electrically connected to a first terminal of the second switching sub-circuit, a first terminal electrically connected to a light-emitting element, and a second terminal electrically connected to a power source;
the compensation sub-circuit has a first terminal electrically connected to the first terminal of the driving sub-circuit, and a second terminal electrically connected to the control terminal of the driving sub-circuit;
the first switching sub-circuit has a control terminal electrically connected to a first signal input terminal, a first terminal electrically connected to the first terminal of the driving sub-circuit, and a second terminal electrically connected to an initial voltage input terminal; and
the second switching sub-circuit has a control terminal electrically connected to a second signal input terminal, a first terminal electrically connected to the control terminal of the driving sub-circuit, and a second terminal electrically connected to a data signal input terminal,
wherein the second switching, sub-circuit is configured to receive a compensated data voltage from the data signal input terminal, wherein the compensated data voltage is determined based on a threshold voltage and a mobility of the driving sub-circuit.

2. The pixel driving circuit according to claim 1 , wherein
in a resetting phase, the first switching sub-circuit is configured to be in a turn-on state under control of the first signal input terminal, and the second switching sub-circuit is configured to be in a turn-on state within a preset time under control of the second signal input terminal; and
in a compensation phase, the first switching sub-circuit is configured to be in a turn-off state under control of the first signal input terminal, and the second switching sub-circuit is configured to be in a turn-on state within the preset time under control of the second signal input terminal.

3. The pixel driving circuit according to claim 2 , wherein
in a data writing phase, the first switching sub-circuit is configured to be in a turn-off state under control of the first signal input terminal, and the second switching sub-circuit is configured to be in a turn-on state under control of the second signal input terminal; and
in a light-emitting phase, the first switching sub-circuit is configured to be in a turn-off state under control of the first signal input terminal, and the second switching sub-circuit is configured to be in a turn-off state under control of the second signal input terminal.

4. The pixel driving circuit according to claim 3 , wherein a duration of the resetting phase is less than that of the compensation phase, and a duration of the data writing phase is less than that of the resetting phase.

5. A display panel, comprising the pixel driving circuit according to claim 1 .

6. The display panel according to claim 5 , further comprising: a controller configured to:
detect a current threshold voltage and a current mobility of the driving sub-circuit;
generate a threshold compensation voltage and a first mobility compensation voltage according to the current threshold voltage and the current mobility of the driving sub-circuit;
generate a total compensation voltage according to the threshold compensation voltage and the first mobility compensation voltage when the threshold compensation voltage is greater than a first preset threshold; and
compensate for a data voltage input to the pixel driving circuit according to the total compensation voltage.

7. The display panel according to claim 6 , wherein the controller is further configured to: when the mobility of the driving sub-circuit changes, generate a second mobility compensation voltage according to the current threshold voltage and the changed mobility, and update the total compensation voltage according to the second mobility compensation voltage when a voltage difference between the first mobility compensation voltage and the second mobility compensation voltage is greater than a second preset threshold.

8. The display panel according to claim 7 , wherein the controller is further configured to: acquire a power-off threshold voltage and a power-off mobility of the driving sub-circuit when a pixel is powered off to stop emitting light, and store the power-off threshold voltage and the power-off mobility through a memory, so that the power-off threshold voltage and the power-off mobility stored in the memory are used as an initial threshold voltage and an initial mobility respectively after the pixel is powered on again.

9. A method for driving the pixel driving circuit according to claim 1 , comprising:
in a resetting phase, controlling the first switching sub-circuit to be turned on, and controlling the second switching sub-circuit to be turned on for a preset time; and
in a compensation phase, controlling the first switching sub-circuit to be turned off, and controlling the second switching sub-circuit to be turned on for the preset time.

10. The method according to claim 9 , further comprising:
in a data writing phase, controlling the first switching sub-circuit to be turned off, and controlling the second switching sub-circuit to be turned on; and
in a light-emitting phase, controlling the first switching sub-circuit and the second switching sub-circuit to be turned off.

11. The method according to claim 10 , wherein a duration of the resetting phase is less than that of the compensation phase, and a duration of the data writing phase is less than that of the resetting phase.

12. A method by the display panel according to claim 5 , comprising:
detecting a current threshold voltage and a current mobility of the driving sub-circuit;
generating a threshold compensation voltage and a first mobility compensation voltage according to the current threshold voltage and the current mobility of the driving sub-circuit; and
generating a total compensation voltage according to the threshold compensation voltage and the first mobility compensation voltage when the threshold compensation voltage is greater than a first preset threshold; and
compensating for a data voltage input at the data signal input terminal according to the total compensation voltage.

13. The method according to claim 12 , further comprising:
when the mobility of the driving sub-circuit changes, generating a second mobility compensation voltage according to the current threshold voltage and the changed mobility;
determining whether a voltage difference between the first mobility compensation voltage and the second mobility compensation voltage is greater than a second preset threshold; and
if the voltage difference is greater than the second preset threshold, updating the total compensation voltage according to the second mobility compensation voltage.

14. The method according to claim 13 , further comprising:
acquiring a power-off threshold voltage and a power-off mobility of the driving sub-circuit when the pixel is powered off to stop emitting light, and storing the power-off threshold voltage and the power-off mobility, so that the stored power-off threshold voltage and power-off mobility are used as an initial threshold voltage and an initial mobility respectively after the pixel is powered on again.

15. The pixel driving circuit according to claim 1 , wherein the driving sub-circuit comprises a driving transistor, the compensation sub-circuit compri

Assignees

• Boe Technology Group Co Ltd
• Boe Tech Group Ltd

Inventors

• Li Yongqian
• Xu Pan
• Li Quanhu

Classifications

• G09G2320/045

  Compensation of drifts in the characteristics of light emitting or modulating elements · CPC title

• G09G2320/0233

  Improving the luminance or brightness uniformity across the screen · CPC title

• G09G3/3275

  Details of drivers for data electrodes · CPC title

• G09G3/3233 Primary

  with pixel circuitry controlling the current through the light-emitting element · CPC title

• G09G3/3291

  in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements · CPC title