Resetting cycle for aging compensation in AMOLED displays

• US 10,699,613 B2
• Filed: 03/02/2016
• Issued: 06/30/2020
• Est. Priority Date: 11/30/2009
• Status: Active Grant

• Current Assignee: IGNIS Innovation Incorporated
• Original Assignee: IGNIS Innovation Incorporated
• Inventors: Chaji, Gholamreza, Dionne, Joseph Marcel, Azizi, Yaser, Jaffari, Javid, Hormati, Abbas, Liu, Tong, Alexander, Stefan
• Primary Examiner(s): Satanovsky, Alexander
• Application Number:
  US15/058,939
• Publication Number:
  US 20160180755A1
• Time in Patent Office: 1,581 Days
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/0295 by monitoring each display pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3258 with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 3/3291 in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements

Abstract

A method of voltage-programming a pixel circuit in a display panel to remove, before programming the pixel circuit, effects due to short-term effects such as caused by fast light transitions or effects due to previous pixel circuit measurements such as charge trapping. During a resetting cycle, the pixel circuit is programmed with a reset voltage value corresponding to a maximum or a minimum voltage value. Then, during a calibration cycle, the pixel circuit is programmed with a calibration voltage based on previously extracted data for the pixel circuit, a pixel current of the pixel circuit is measured, and the extracted data for the pixel circuit is updated based on the measured pixel current. Then, the pixel circuit is programmed with a video data that is calibrated with the updated extracted data. The pixel circuit is finally driven according to the programmed video data and emits a commensurate amount of light.

Claims

1. A method of voltage programming of a pixel circuit in a display panel, the pixel circuit including a light emitting device, the method comprising:

driving the pixel circuit;

during a first operating cycle of the pixel;

programming the pixel circuit with a calibration voltage based on previously extracted data for the pixel circuit;

measuring a pixel current of the pixel circuit; and

updating the previously extracted data for the pixel circuit based on the measured pixel current; and

following the driving of the pixel circuit and prior to the first operating cycle of the pixel, resetting the pixel by;

programming the pixel circuit with a reset voltage value which reduces the effect of at least one adverse artifact resulting from the driving of the pixel circuit on the first operating cycle of the pixel.

2. The method of claim 1, wherein the reset voltage value corresponds to a maximum or a minimum voltage value which reduces the effect of at least one adverse artifact resulting from the driving of the pixel circuit on the first operating cycle of the pixel.

3. The method of claim 1, wherein driving the pixel circuit comprises at least one of driving the light emitting device of the pixel circuit and performing a previous measurement on the pixel circuit.

4. The method of claim 1, wherein the at least one adverse artifact comprises charge trapping in the pixel circuit.

5. The method of claim 1, wherein the at least one adverse artifact comprises a storage capacitor of the pixel circuit retaining a residual amount of charge following the driving of the pixel circuit.

6. The method of claim 1, wherein the at least one adverse artifact comprises a pixel circuit artifact due to rapid transitions in light previously emitted by the pixel circuit.

7. The method of claim 1, wherein the reset voltage value corresponds to a full black or full white value for the pixel circuit.

8. The method of claim 1, wherein the previously extracted data comprises previously extracted parameters for the pixel circuit.

9. The method of claim 1, wherein the calibration voltage is further based on a predefined current, voltage, or brightness for the pixel circuit.

10. The method of claim 1, wherein driving the pixel circuit comprises driving a light emitting device of the pixel circuit according to programmed display data to display an image in the display panel.

11. The method of claim 1, further comprising following the updating of the previously extracted data, programming the pixel circuit with display data that is calibrated with the updated extracted data.

12. The method of claim 11, further comprising following the programming of the pixel circuit with display data that is calibrated, driving the pixel circuit according to the display data that is calibrated.

13. A method of voltage programming of a pixel circuit in a display panel, the pixel circuit including a light emitting device, the method comprising:

driving the pixel circuit;

during a first operating cycle of the pixel;

programming the pixel circuit with a calibration voltage based on previously extracted data for the pixel circuit;

measuring a pixel current of the pixel circuit; and

updating the previously extracted data for the pixel circuit based on the measured pixel current; and

resetting the pixel circuit during a resetting cycle following the driving of the pixel circuit and immediately prior to the first operating cycle, the first operating cycle prior to emission of light by the pixel circuit in a subsequent driving cycle.

14. The method of claim 13, wherein driving the pixel circuit comprises at least one of performing a previous measurement on the pixel circuit and driving the light emitting device of the pixel circuit.

15. The method of claim 13, wherein resetting the pixel circuit comprises programming the pixel circuit with a reset voltage value.

16. The method of claim 15, wherein the reset voltage value corresponds to a full black or full white value for the pixel circuit.

17. The method of claim 15, wherein the reset voltage value reduces the effect of at least one adverse artifact resulting from the driving of the pixel circuit on the first operating cycle of the pixel.

18. The method of claim 17, wherein the at least one adverse artifact comprises charge trapping in the pixel circuit.

19. The method of claim 17, wherein the at least one adverse artifact comprises a storage capacitor of the pixel circuit retaining a residual amount of charge following the driving of the pixel circuit.

20. The method of claim 17, wherein the at least one adverse artifact comprises a pixel circuit artifact due to rapid transitions in light previously emitted by the pixel circuit.