IP Library Granted Patent US 8,736,524
Granted Patent B2
US 8,736,524 · App. 13/568,784 · Granted May 27, 2014

Method and system for programming, calibrating and driving a light emitting device display

Inventors: Arokia Nathan (Cambridge, GB); Gholamreza Reza Chaji (Waterloo, CA); Peyman Servati (Vancouver, CA)
Assignee: Ignis Innovation, Inc.
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Quick Facts
Patent No.
US 8,736,524
App. No.
13/568,784
Granted
May 27, 2014
Kind
B2
Abstract

A method and system for programming, calibrating and driving a light emitting device display is provided. The system may include extracting a time dependent parameter of a pixel for calibration.

Claims (31)

1. A method of driving a display array, the display array including a plurality of pixel circuits, each pixel circuit including a driving transistor, at least one switch transistor, a storage capacitor and an organic light emitting device, the method comprising the steps of:

applying a current or voltage to the organic light emitting device;

monitoring a current or voltage flowing through the organic light emitting device;

predicting a shift in the voltage of the organic light emitting device, based on the monitored current or voltage and determining the state of the pixel circuit, the predicting including estimating an intermediate voltage of the organic light emitting diode, wherein the estimating includes adjusting the intermediate voltage based on a resolution of a driver circuit coupled to the driving transistor and increasing the intermediate voltage by the resolution of the driver circuit responsive to an actual voltage shift being larger than the intermediate voltage; and

providing, to the organic light emitting device, a bias associated with the shift in the voltage of the organic light emitting device.

2. A method according to claim 1 , further comprising modifying a programming voltage by a voltage based on the monitored current or voltage such that a substantially constant output brightness of the light emitting device is maintained.

3. A method according to claim 1 , wherein the monitoring a current or voltage comprises applying a first current or a first voltage to the light emitting device during a first phase and extracting the monitored voltage or monitored current from the light emitting device during a second phase following the first phase.

4. A method according to claim 3 , wherein the monitoring and the extracting are carried out using the same line.

5. A method according to claim 1 , wherein the estimating includes decreasing the intermediate voltage by the resolution of the driver circuit responsive to an actual voltage shift being larger than the intermediate voltage.

6. A method according to claim 1 , wherein the applying the current or the voltage includes the providing the bias.

7. A method according to claim 1 , wherein the monitoring a current or voltage includes:

during a first operating cycle of an extraction cycle, activating a first select line to couple a data line to a gate of the driving transistor through the at least one switch transistor, and

during the first operating cycle, activating a second select line to couple a monitor line to a drain of the driving transistor through a second switch transistor connected to the driving transistor;

during the first operating cycle, applying a first current or a first voltage to the light emitting device via the monitor line while maintaining the data line at a first potential; and

during a second operating cycle following the first operating cycle, deactivating the first select line switching while the second select line remains activated and the data line remains at the first potential, extracting a monitored voltage or monitored current from the light emitting device via the monitor line.

8. A method of driving a display array, the display array including a plurality of pixel circuits, each pixel circuit including a driving transistor, at least one switch transistor, a storage capacitor and an organic light emitting device (OLED), the method comprising the steps of:

applying a current or voltage to the OLED;

monitoring a current or voltage flowing through the OLED;

predicting a shift in the voltage of the OLED, based on the monitored current or voltage and determining the state of the pixel circuit; and

providing, to the OLED, a bias associated with the shift in the voltage of the OLED,

wherein the monitoring the current or voltage includes:

during a first operating cycle of an extraction cycle, activating a first select line to couple a data line to a gate of the driving transistor through the at least one switch transistor;

during the first operating cycle, activating a second select line to couple a monitor line to a drain of the driving transistor through a second switch transistor connected to the driving transistor;

during the first operating cycle, applying a first current or a first voltage to the light emitting device via the monitor line while maintaining the data line at a first potential; and

during a second operating cycle following the first operating cycle, deactivating the first select line while the second select line remains activated and the data line remains at the first potential; and

extracting a monitored voltage or monitored current from the OLED via the monitor line.

9. A method of driving a display array, the display array including a plurality of pixel circuits, each pixel circuit including a driving transistor, at least one switch transistor, a storage capacitor and an organic light emitting device (OLED), the method comprising the steps of:

applying a current or voltage to the OLED;

monitoring a current or voltage flowing through the OLED;

predicting a shift in the voltage of the OLED, based on the monitored current or voltage and determining the state of the pixel circuit, wherein the predicting includes estimating an intermediate voltage of the OLED, the estimating including adjusting the intermediate voltage based on a resolution of a driver circuit coupled to the driving transistor and decreasing the intermediate voltage by the resolution of the driver circuit responsive to an actual voltage shift being larger than the intermediate voltage; and

providing, to the OLED, a bias associated with the shift in the voltage of the OLED.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 19, 2023
From: IGNIS INNOVATION INC.
To: IGNIS INNOVATION INC.
Reel/Frame 063706/0406 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 7, 2012
From: NATHAN, AROKIA; CHAJI, GHOLAMREZA REZA; SERVATI, PEYMAN
To: IGNIS INNOVATION INC.
Reel/Frame 028741/0976 →
Priority Claims (4)
CA 2490860 · Dec 15, 2004 · national
CA 2503237 · Apr 8, 2005 · national
CA 2509201 · Jun 8, 2005 · national
CA 2521986 · Oct 17, 2005 · national
Continuity (3)
Continuation 12571968 · Oct 1, 2009
Continuation 11304162 · Dec 15, 2005
Related Publication 20130027381A1 · Jan 31, 2013