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

Volume

4

Issue

1

fYear

2008

fDate

3/1/2008 12:00:00 AM

Firstpage

54

Lastpage

60

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);

fLanguage

English

Journal_Title

Display Technology, Journal of

Publisher

ieee

ISSN

1551-319X

Type

jour

DOI

10.1109/JDT.2007.901555

Filename

4356475