Patent ID: 8525819

Claim:
A semiconductor device comprising: a first driver circuit; a second driver circuit; a third driver circuit; and a pixel portion comprising a first transistor, a second transistor, a third transistor and a photoelectric transducer, wherein a gate of the first transistor is electrically connected to the photoelectric transducer, wherein one of a source and a drain of the second transistor is electrically connected to the gate of the first transistor, wherein one of a source and a drain of the third transistor is electrically connected to the first transistor, wherein one of a source and a drain of the first transistor is electrically connected to a first line, wherein a gate of the second transistor is electrically connected to a second line, wherein a gate of the third transistor is electrically connected to a third line, wherein the other of the source and the drain of the first transistor is electrically connected to a fourth line, wherein the first line is electrically connected to the first driver circuit, wherein the second line is electrically connected to the second driver circuit, wherein the third line is electrically connected to the third driver circuit, wherein the third driver circuit is configured to output a first signal comprising a first pulse having a first pulse width to the third line in one frame period, wherein the second driver circuit is configured to output a second signal comprising a second pulse having a second pulse width longer than the first pulse width to the second line in the one frame period, wherein the first transistor is configured to output a third signal and a fourth signal to the first line in the one frame period, and wherein each of the third signal and the fourth signal is a signal depending on a potential of the gate of the first transistor.