Resetting cycle for aging compensation in AMOLED displays

• US 9,311,859 B2
• Filed: 05/09/2013
• Issued: 04/12/2016
• 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:
  US13/890,926
• Publication Number:
  US 20130257845A1
• Time in Patent Office: 1,069 Days
• Field of Search: 702/58, 702/57, 345 76- 83, 345/212, 345/690, 315/169.3
• US Class Current: 1/1
• 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 a pixel circuit in a display panel, comprising:

driving the pixel circuit according to programmed video data to display an image in the display panel;

during a resetting cycle following the driving of the pixel circuit, programming the pixel circuit with a reset voltage value corresponding to a maximum or a minimum voltage value, to reduce the effect on a calibration cycle of adverse artifacts resulting from the driving of the pixel circuit;

responsive to the resetting cycle, during the calibration cycle, 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 extracted data for the pixel circuit based on the measured pixel current;

responsive to the calibration cycle, during a programming cycle, programming the pixel circuit with video data that is calibrated with the updated extracted data; and

responsive to the programming cycle, during a driving cycle, driving the pixel circuit according to the programmed video data to display an image in the display panel.

2. The method of claim 1, wherein the maximum voltage value corresponds to at least a full white value, and wherein the minimum value corresponds to a full black value.