A LED pixel structure that reduces current nonuniformities and threshold voltage variations in a "drive transistor"of the pixel structure is disclosed. The LED pixel structure incorporates a current source for loading data into the pixel via a data line. Alternatively, an auto zero voltage is determined...http://www.google.de/patents/US6229506?utm_source=gb-gplus-sharePatent US6229506 - Active matrix light emitting diode pixel structure and concomitant method
