P‐143: A Novel Current‐Scaling a‐Si:H TFTs Pixel Electrode Circuit for Active‐Matrix Organic Light‐Emitting Displays

摘要

Hydrogenated amorphous silicon thin‐film transistor (a‐Si:H TFT) pixel electrode circuit with a function of current scaling is proposed for active‐matrix organic light‐emitting displays (AM‐OLEDs). In contrast to the conventional current mirror pixel electrode circuit, in this circuit a high data‐to‐organic light‐emitting device (OLED) current ratio can be achieved, without increasing the a‐Si:H TFT size, by using a cascade structure of storage capacitors. Moreover, the proposed circuit can compensate for the variations of TFT threshold voltage. Simulation results, based on a‐Si:H TFT and OLED experimental data, showed that a data‐to‐OLED current ratio larger than 10 and a fast pixel programming time can be accomplished with the proposed circuit.