A touch screen display device is described that includes a display panel, a display driver, a sensor circuit and a combination unit. The display panel has a plurality of display elements arranged between a first and a second electrode layer. The display driver is arranged for providing display signals comprising a common display signal and an input control signal to the display panel. The sensor circuit is arranged for providing a probe signal and a shield signal mutually having the same phase and frequency and for generating a touch signal in response to the output signal received from the first electrode layer. The combination unit provides a drive signal to the first electrode layer derived from the common display signal and the probe signal, and further provides an output control signal for the display panel from the input control signal and the shield signal.