Title :
A driving scheme for active-matrix organic light-emitting diode displays based on feedback
Author :
Ashtiani, Shahin J. ; Nathan, Arokia
Author_Institution :
Dept. of Electr. & Comput. Eng., Waterloo Univ., Ont.
Abstract :
A scheme of driving active matrix organic light emitting diode (AMOLED) displays with hydrogenated amorphous silicon (a-Si) thin-film transistors (TFTs) is presented. By sending a feedback voltage from each pixel to a column driver during the programming cycle, the driving scheme can compensate for the instability of the TFTs, in particular, the shift in the threshold voltage. Measurement results show no change in the OLED current in the presence of a 1.3-V shift in the threshold voltage. Based on circuit analysis, a simple lead compensator and an accelerating pulse were employed to achieve fast pixel programming for a wide range of OLED currents. Simulation results show a programming time of less than 70 mus for OLED currents as low as 50 nA
Keywords :
LED displays; amorphous semiconductors; driver circuits; feedback; organic light emitting diodes; silicon; thin film transistors; OLED current; Si; accelerating pulse; active-matrix organic light-emitting diode displays; circuit analysis; column drivers; fast pixel programming; feedback voltage; hydrogenated amorphous silicon; lead compensator; thin-film transistors; threshold voltage shift; Active matrix organic light emitting diodes; Active matrix technology; Amorphous silicon; Current measurement; Driver circuits; Feedback; Flat panel displays; Organic light emitting diodes; Thin film transistors; Threshold voltage; Accelerating pulse; active matrix organic light-emitting diode (AMOLED); amorphous silicon; column driver; feedback; lead compensation; pixel circuit; thin-film transistor (TFT);
Journal_Title :
Display Technology, Journal of
DOI :
10.1109/JDT.2006.875140
