Patent ID: 7903079

Claim:
An active matrix liquid crystal display device comprising: a pixel including a pixel thin film transistor; and a driver circuit electrically connected to a gate of the pixel thin film transistor, the driver circuit comprising: a first thin film transistor wherein a gate of the first thin film transistor is electrically connected to one of a source and a drain of the first thin film transistor; a second thin film transistor wherein one of a source and a drain of the second thin film transistor is electrically connected to the other of the source and the drain of the first thin film transistor; a third thin film transistor wherein a gate of the third thin film transistor is electrically connected to the other of the source and the drain of the first thin film transistor, and one of a source and a drain of the third thin film transistor is electrically connected to the one of the source and the drain of the first thin film transistor; and a fourth thin film transistor wherein a gate of the fourth thin film transistor is electrically connected to a gate of the second thin film transistor, one of a source and a drain of the fourth thin film transistor is electrically connected to the other of the source and the drain of the third thin film transistor, and the other of the source and the drain of the fourth thin film transistor is electrically connected to the other of the source and the drain of the second thin film transistor, wherein the pixel thin film transistor and the first to fourth thin film transistors have a N-channel type, and wherein the pixel thin film transistor and the first to fourth thin film transistors are formed over a glass substrate.