Driver circuit, display device including the driver circuit, and electronic appliance including the display device

摘要

An object of the present invention is to provide a driver circuit including a normally-on thin film transistor, which driver circuit ensures a small malfunction and highly reliable operation. The driver circuit includes a static shift register including an inverter circuit having a first transistor and a second transistor, and a switch including a third transistor. The first to third transistors each include a semiconductor layer of an oxide semiconductor and are depletion-mode transistors. An amplitude voltage of clock signals for driving the third transistor is higher than a power supply voltage for driving the inverter circuit.

主权项

1. A semiconductor device comprising a shift register circuit, the shift register circuit comprising:
a first transistor; a second transistor; and a third transistor, wherein each of the first transistor, the second transistor, the third transistor, and the fourth transistor includes a gate electrode, a gate insulating film, and an oxide semiconductor layer, wherein the first transistor, the second transistor, and the third transistor are depletion-mode transistors, wherein one of a source and a drain of the first transistor is connected to one of a source and a drain of the second transistor, wherein a gate of the first transistor is connected to the other of the source and the drain of the first transistor, wherein one of a source and a drain of the third transistor is connected to a gate of the second transistor, wherein a first signal is input to a gate of the third transistor, and wherein an amplitude voltage of the first signal is greater than a potential difference between the other of the source and the drain of the first transistor and the other of the source and the drain of the second transistor.