Patent ID: 7230601

Claim:
A display system comprising: a plurality of pixels, each of the plurality of pixels comprising a first thin film transistors over a substrate having an insulating surface; a driver circuit for outputting an inputted image signal to the plurality of pixels, the driver circuit comprising a second thin film transistor over the substrate; and a first means for storing the image signal to be outputted to the driver circuit, the first means comprising a third thin film transistor over the substrate, wherein each of the first to the third thin film transistors comprises a first electrode and a second electrode overlapped with a first channel region though insulating films, wherein the first electrode and the second electrode are overlapped with each other so as to sandwich the first channel region therebetween, wherein each of the plurality of pixels comprises a fourth thin film transistor connected to a light emitting element, wherein the fourth thin film transistor comprises a third electrode and a fourth electrode overlapped with each other so as to sandwich a second channel region therebetween and connected to each other, wherein the first thin film transistor further comprises a fifth electrode connected to the second electrode and overlapped with the first electrode through the insulating film, wherein the first electrode and the fifth electrode are overlapped with each other so as to sandwich a third channel region therebetween, and wherein an LDD region is interposed between the third channel region and the first channel region.