Multi-touch system and method for controlling liquid crystal capacitors to reduce touch sensing interference

摘要

A multi-touch system for controlling liquid crystal capacitors to reduce touch sensing interferences includes K gate driving lines, which are divided into N groups each corresponding to a common voltage conductive line. When a display driving signal is applied to an i-th group of gate driving lines for performing a display driving, the liquid crystal capacitor corresponding to the i-th group is set to a predetermined voltage, where i=1 to N. Finally, a touch driving signal is applied to an i-th common voltage conductive line corresponding to the i-th group for sensing touch points, so as to reduce touch sensing affections caused by noises of the liquid crystal display.

主权项

1. A multi-touch system for controlling liquid crystal capacitors to reduce touch sensing interferences, comprising:
a touch LCD panel including: a thin film transistor (TFT) layer, having K gate driving lines and L source driving lines for driving corresponding display transistors and liquid crystal capacitors according to a display pixel signal and a display driving signal so as to perform a display driving; a common voltage layer, which is arranged on the TFT layer and has N common voltage conductive lines for receiving a common voltage on displaying; a sensing electrode layer, which is arranged on the common voltage layer and has M sense conductive lines, for sensing whether an external object approaches or not while the common voltage conductive line transmits a touch driving signal; and a touch display control subsystem, connected to the TFT layer and the common voltage layer, for providing the display driving signal to the K gate driving lines sequentially to activate the corresponding display transistors and providing the display pixel signal to the L source driving lines to perform the display driving, and further providing the touch driving signal to the N common voltage conductive lines sequentially and sampling sensing voltages of the M sense conductive lines to detect whether the external object approaches or not, where K, L, M, N are positive integer respectively; wherein the K gate driving lines are divided into N groups and each group of gate driving lines corresponds to a common voltage conductive line, and when the touch display control subsystem provides the display driving signal to an i-th group of gate driving lines for performing the display driving at a first time interval T1, said liquid crystal capacitors corresponding to the i-th group are set to a predetermined voltage at a second time interval T2, and the touch display control subsystem provides the touch driving signal to an i-th common voltage conductive line for performing a touch sensing by the M sense conductive lines at a third time interval T3, where i=1 to N.