Title :
A Novel Voltage-Feedback Pixel Circuit for AMOLED Displays
Author :
Lin, Chih-Lung ; Tsai, Tsung-Ting ; Chen, Yung-Chih
Author_Institution :
Nat. Cheng Kung Univ., Tainan
fDate :
3/1/2008 12:00:00 AM
Abstract :
This study presents a novel voltage-modulated pixel circuit for active-matrix organic light-emitting diode (AMOLED) consisting of five n-type thin-film transistors (TFTs), one additional control signal, and one storage capacitor. The proposed circuit, which can be implemented in all-n-type and all-p-type low temperature poly-silicon (LTPS) TFT technologies, successfully compensates for threshold voltage deviation of TFTs and facilitates correction of OLED degradation using a voltage feedback method. Simulation and experimental results for all-n-type TFTs indicate that the proposed pixel circuit reduced the nonuniformity brightness problem effectively by compensating for threshold voltage variation in TFTs and reduced the degradation of emission efficiency in OLEDs.
Keywords :
LED displays; capacitors; feedback; thin film transistors; AMOLED displays; OLED degradation; active-matrix organic light-emitting diode; low temperature poly-silicon TFT technologies; storage capacitor; thin-film transistors; threshold voltage variation; voltage feedback method; voltage-feedback pixel circuit; voltage-modulated pixel circuit; Active-matrix organic light-emitting diode (AMOLED); amorphous silicon (a-Si); degradation; low-temperature poly-silicon (LTPS);
Journal_Title :
Display Technology, Journal of
DOI :
10.1109/JDT.2007.901555
