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Design of Low Power LTPS AMOLED Panel and Pixel Compensation Circuit with High Aperture Ratio  

Kang, Hong-Seok (School of Information, Communications & Electronic Engineering, The Catholic University of Korea)
Woo, Doo-Hyung (School of Information, Communications & Electronic Engineering, The Catholic University of Korea)
Publication Information
Journal of the Institute of Electronics Engineers of Korea SD / v.47, no.10, 2010 , pp. 34-41 More about this Journal
Abstract
We proposed the new pixel compensation circuit with high aperture ratio and the driving method for the large-area, low-power AMOLED applications in this study. We designed with the low-temperature poly-silicon(LTPS) thin film transistors(TFTs) that has poor uniformity but good mobility and stability. To lower the error rate of the pixel circuit and to improve the aperture ratio for bottom emission method, we simplified the pixel compensation circuit. Because the proposed pixel compensation circuit with high aperture ratio has very low contrast ratio for conventional driving methods, we proposed the new driving method and circuit for high contrast ratio. Black data insertion was introduced to improve the characteristics for moving images. The pixel circuit was designed for 19.6" WXGA bottom-emission AMOLED panel, and the average aperture ratio of the pixel circuit is improved from 33.0% to 41.9%. For the TFT's $V_{TH}$ variation of ${\pm}0.2\;V$, the non-uniformity and contrast ratio of the designed panel was estimated under 6% and over 100000:1 respectively.
Keywords
AMOLED; LTPS TFT; compensation circuits; high aperture ratio;
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