Provided is a display device having a photodetecting element in a pixel, and having an input function that is not dependent on light environments. This is a display device having an optical sensor in a pixel region. The optical sensor includes a first sensor pixel circuit that outputs a sensor signal corresponding to electric charges accumulated during an accumulation period in an ON time of a light source for the sensor; and a second sensor pixel circuit that that outputs a sensor signal corresponding to electric charges accumulated during an accumulation period in an OFF time of the light source. A sensor driving circuit for driving the first sensor pixie circuit and the second sensor pixel circuit supplies reset signals (RST1, RST2) to the first sensor pixel circuit and the second sensor pixel circuit, respectively, during vertical flyback periods in pixel display in the pixel region.