A display device with a touch screen includes: first sensing units, each first sensing unit comprising first optical sensors connected in series, each first sensing unit comprising a first terminal for receiving a first voltage, each first sensing unit extending in a first direction; second sensing units, each second sensing unit comprising second optical sensors connected in series, each second sensing unit comprising a first terminal for receiving a second voltage, each second sensing unit extending in a second direction transverse to the first direction; a reset unit for applying a reset voltage to a second terminal of each of the first and second sensing units; and a read-out unit for sensing a touch position based on voltage changes at the second terminals of the first and second sensing units.