Patent ID: 8217395

Claim:
A semiconductor device comprising: a driver circuit comprising: a buffer circuit comprising a first thin film transistor, a second thin film transistor, a third thin film transistor, and a fourth thin film transistor; and a logic circuit comprising a fifth thin film transistor, wherein a channel region of the first thin film transistor and a channel region of the second thin film transistor are arranged to be symmetrical with respect to a point, wherein a channel region of the third thin film transistor and a channel region of the fourth thin film transistor are arranged to be symmetrical with respect to the point, wherein a gate of the first thin film transistor and a gate of the second thin film transistor are electrically connected to each other, wherein a gate of the third thin film transistor and a gate of the fourth thin film transistor are electrically connected to each other, wherein a terminal of the first thin film transistor, a terminal of the second thin film transistor, a terminal of the third thin film transistor, and a terminal of the fourth thin film transistor are electrically connected to one another, wherein a channel length of the first thin film transistor is twice or more as compared with a channel length of the fifth thin film transistor.