Display device with optical sensors

A display device comprising:

• a plurality of sensing units each of which comprises a plurality of optical sensors operating in a turn-off region, each said sensing unit having a capacitor which converts, into a voltage change, a change in an optical leakage current that flows through the sensing unit's optical sensors;
• a reset unit which applies a reset voltage to each of the sensing units;
• and
• a read-out unit which senses a touch position based on the voltage change caused by touching at least one of the optical sensors.

A method of driving a display device, the method comprising:

• biasing a plurality of optical sensors included in each of a plurality of sensing units so that the optical sensors operate in a turn-off region;
• applying a reset voltage to a terminal of each of the sensing units;
• converting, into a voltage change at the terminal of each of the sensing units, a change in an optical leakage current flowing through at least one of the optical sensors;
• and
• sensing a touch position based on the voltage changes at the terminals of the sensing units.