Display device with touch panel function

A display device having a touch panel function, comprising:

• a plurality of pixel circuits arranged in a matrix shape;
• a plurality of sensing circuits arranged in a region between the adjacent pixel circuits for reading out a magnitude of coupling capacitance;
• a plurality of scanning lines arranged in a row direction along which the plurality of pixel circuits extend for use of the pixel circuits and the sensing circuits;
• a plurality of signal lines arranged in a column direction along which the plurality of pixel circuits extend for use of the pixel circuits and the sensing circuits, some of the signal lines being commonly used for the pixel circuits and the sensing circuits;
• a display driver for writing a display signal in the pixel circuit every row line by driving the plurality of scanning lines and signal lines in a display operation period;
• a sensing driver for sensing a signal showing magnitude of the coupling capacitance from the sensing circuit every row line by driving the plurality of scanning lines and signal lines in a sensing operation period;
• and
• a control portion for controlling the display driver and the sensing driver, wherein
• while the display operation period and the sensing operation period are repeated in turns,
• while the sensing operation is performed, a voltage with a smaller value than a voltage range used for the display operation is written into the signal lines,
• a voltage in the range used for the displaying operation is written into the signal line in a preliminary writing operation period between after the sensing operation period and before the display operation period.