Patent ID: 7868857

Claim:
A system for compensating non-uniformities in a light emitting device display, comprising: a driver for driving a pixel array having a plurality of pixel circuits in an illumination operation and in a degradation estimation operation, each pixel circuit comprising: a capacitor; a first transistor selected by a select line; a second transistor coupled to a light emitting device; and a third transistor and a fourth transistor coupled between a data line and a potential in series; wherein each transistor has a gate terminal, the gate terminal of the first transistor and the gate terminal of the third transistor coupled to the select line, the gate terminal of the fourth transistor and the capacitor coupled to the gate terminal of the second transistor, the first transistor coupled to the data line and the gate terminal of the second transistor; a measuring module for measuring current or voltage on the data line coupled to a first-pixel circuit in the degradation estimation operation; and a modifying module for modifying pixel data, the pixel data being applied to the first pixel circuit or a second pixel circuit-in the pixel array in the illumination operation, including: an estimating module for estimating a degradation of the first pixel circuit based on the measured current or voltage; and a compensating module for correcting the pixel data based on the estimated degradation of the first pixel circuit.