International Display Workshops General Incorporated Association

Proceedings of the International Display Workshops Volume 26 (IDW '19)

Proceedings of the International Display Workshops Volume 26 (IDW '19)

Nov 27, 2019 - Nov 29, 2019
Sapporo Convention Center

4:05 PM - 4:25 PM

[AMD8-4] A Novel OLED Pixel Circuit with Controllable Threshold Voltage Compensation Time

*Jung Chul Kim1, Seonghwan Hong1, Sujin Jung1, Mihee Sin2, Jun Suk Yoo2, Han Wook Hwang2, Yong Min Ha2, Hyun Jae Kim1 (1. Yonsei University (Korea), 2. LG Display, Ltd. (Korea))

High frame frequency, Moving image quality, Compensation time

https://doi.org/10.36463/idw.2019.0505

This paper proposes a novel pixel circuit that adopts low temperature polycrystalline silicon thin-film transistors (LTPS TFTs) to compensate deviation of threshold voltage (VTH) of the driving TFTs (D-TFTs) and uses overlapping compensation times (TCOM) to extend the period of precise sensing VTH variation of the D-TFTs in each pixel. Simulation and experimental results demonstrate the proposed pixel circuit under 120 Hz Ultra High Definition (UHD) driving condition has the same compensation performance as the 60 Hz Full HD (FHD) driving condition. Therefore, the proposed pixel circuit is suitable to be used in AMOLED display with high resolution and high-frame rate and can realize uniform OLED current (IOLED) with high immunity to VTH variation of the D-TFTs.