Semiconductor Device

A semiconductor device comprising:

• a driver circuit comprising a plurality of pulse output circuits each having first to third transistors and first to fourth terminals respectively connected to first to fourth signal lines, and
• a pixel portion,
• wherein a first terminal of the first transistor is electrically connected to the first signal line,
• wherein a second terminal of the first transistor is electrically connected to the fourth signal line,
• wherein a gate and a first terminal of the second transistor are electrically connected to the third signal line,
• wherein a first terminal of the third transistor is electrically connected to the third signal line,
• wherein a gate of the third transistor is electrically connected to the second signal line,
• wherein a gate of the first transistor, a second terminal of the second transistor, and a second terminal of the third transistor are electrically connected to each other,
• wherein a first clock signal is supplied to the first signal line,
• wherein a second clock signal is supplied to the second signal line,
• wherein a preceding stage signal is supplied to the third signal line,
• wherein an output signal is output from the fourth signal line, and
• wherein duty ratios of the first clock signal and the second clock signal are different from each other.