A system for displaying images includes a touch sensing circuit. The touch sensing circuit comprises a voltage storage unit for detecting whether a touch event has occurred and generates a corresponding voltage. The voltage storage unit comprises first to third capacitors. The first capacitor has a first terminal coupled to a ground terminal and a second terminal coupled to a first node. The second capacitor has a first terminal coupled to the ground terminal and a second terminal coupled to a second node. When the voltage storage unit detects that a touch event has occurred, the second node is coupled to an AC voltage. The third capacitor is formed between the first and second nodes. When the touch event has occurred, a value of the third capacitor is changed, so that the corresponding voltage at the first node is changed.