A touch detecting unit comprises first sensor electrodes arranged in a first direction and electrically connected with one another; second sensor electrodes arranged in a second direction crossing the first direction, and electrically connected with one another, the second sensor electrodes electrically separated from the first sensor electrodes, and third sensor electrodes electrically separated from the first sensor electrodes and the second sensor electrodes. Amounts of change in first capacitances between the first sensor electrodes and the second sensor electrodes are detected in a first mode. Amounts of change in the first capacitances and amounts of change in a second capacitance between the first sensor electrodes and the third sensor electrodes are detected in a second mode.