| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with a touch panel for reliably removing an adverse influence of noise generated from a liquid crystal display device on the position detection of a capacitive touch panel, and for detecting an accurate touch position at any time. <P>SOLUTION: A mask signal generation circuit 51 generates a mask signal voltage Vmsk to generate a pulse according to the polarity inversion cycle of a common signal voltage Vcom transmitted from a display driving control circuit 2 of a liquid crystal display panel, and outputs it to a driving control circuit 56 of a touch panel. The driving control circuit 56 opens first to third switches SW1 to SW3 in synchronization with the pulse of an input mask signal voltage Vmsk, and interrupts measurement of the charging and discharging time of the synthetic capacitance of a capacitance Cp formed by each touch position detection electrode and a base capacitor Csum for scanning, and removes the adverse influence of noise generated in the polarity inversion timing of the common signal voltage Vcom on the measurement of a synthetic capacitance (Cp+Csum). <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
