PROJECT TITLE :

Highly Robust Integrated Gate-Driver for In-Cell Touch TFT-LCD Driven in Time Division Driving Method

ABSTRACT:

This paper proposes a gate driver circuit for in-cell bit thin-film transistor (TFT) liquid crystal displays (LCDs) in which display and bit are driven at separate times to avoid cross-talk between display signals and touch signals. In the standard gate driver circuit, transistors are connected between the gate node of pull-up transistor Q node and also the low DC supply voltage V GL to reset the Q node. In the proposed gate driver gate driver circuit, these transistors are instead connected to the Bit Enable signal. Throughout the show operation, the Bit Enable signal voltage is V GL to operate the proposed gate driver circuit in the identical manner as the standard circuit. Throughout touch operations, the Bit Enable signal changes to the high DC offer voltage V GH to keep the voltage at the Q node constant while not leakage. In simulations and experiments, the proposed gate driver circuit prevented display failures caused by the interval throughout that the show pauses in the center of a frame time for bit operation. The fabricated low temperature poly-silicon (LTPS) TFT-LCD has good multi-touch functionality while not any ghost touches, and achieved 40-dB SNR and one hundred twenty Hz touch report rate.