Patent ID: 8059078

Claim:
A semiconductor device comprising: a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, a first terminal, a second terminal, a third terminal and a fourth terminal, a first wiring and a second wiring, wherein the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, the sixth transistor and the seventh transistor are N-type channel transistors, wherein the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, the sixth transistor and the seventh transistor each includes an amorphous semiconductor, wherein the first terminal is electrically connected to one of source or drain of the second transistor through the first transistor, wherein a gate of the second transistor is electrically connected to the one of source or drain of the second transistor, wherein the other of source or drain of the second transistor is electrically connected to a gate of the third transistor, wherein one of source or drain of the third transistor is electrically connected to the first wiring, wherein the other of source or drain of the third transistor is electrically connected to one of source or drain of the fourth transistor, wherein the second terminal is electrically connected to the other of source or drain of the third transistor, wherein the other of source or drain of the fourth transistor is electrically connected to the second wiring, wherein a gate of the fourth transistor is electrically connected to a gate of the fifth transistor, wherein one of source or drain of the fifth transistor is electrically connected to the other of source or drain of the second transistor, wherein the other of source or drain of the fifth transistor is electrically connected to the second wiring, wherein the third terminal is electrically connected to the gate of the fifth transistor through the sixth transistor, and wherein the fourth terminal is electrically connected to the gate of the fifth transistor through the seventh transistor.