Patent ID: 8575614

Claim:
A display device comprising: a display area with a number of display sections; and a frame area surrounding the display area, wherein the display device further includes at least one photosensor section with a thin-film diode, and wherein each said display section includes an electrode and a thin-film transistor connected to the electrode, and wherein the thin-film transistor and the thin-film diode are arranged on the same light-transmitting substrate, and wherein the thin-film transistor includes: a semiconductor layer with a channel region, a source region and a drain region; a gate electrode that controls the conductivity of the channel region; and a gate insulating film arranged between the semiconductor layer and the gate electrode, and wherein the thin-film diode includes a semiconductor layer with an n-type region, a p-type region and an intrinsic region interposed between the n- and p-type regions, and wherein the respective semiconductor layers of the thin-film transistor and the thin-film diode are portions of a single crystalline semiconductor layer that has been crystallized or re-crystallized by irradiating the same amorphous semiconductor film with a laser beam, and wherein the channel region of the semiconductor layer of the thin-film transistor and the intrinsic region of the semiconductor layer of the thin-film diode have been crystallized to mutually different degrees, and wherein the channel region of the semiconductor layer of the thin-film transistor has a greater average surface roughness Ra than the intrinsic region of the semiconductor layer of the thin-film diode, and wherein the thin-film diode further includes a heat sink layer that is located between the semiconductor layer of the thin-film diode and the substrate, made of an opaque material, and arranged so as to overlap with at least the intrinsic region of the semiconductor layer of the thin-film diode when viewed from under the back surface of the substrate.