Patent ID: 7317438

Claim:
A driving method for a liquid crystal display, wherein one image frame comprises n (n is an integer of 2 or more) subframes, each of which comprises a red image, a green image and a blue image, and wherein a red, a green or a blue backlight turns on corresponding to display of the red image, the green image or the blue image, said method comprising the step of: compressing an original video signal by 1/(3n) times in a time axis direction by a n-speed field sequential color signal generation circuit, and writing a video signal for one of the red image, the green image and the blue image, and turning on the corresponding one of the red, the green and the blue backlight after finishing the writing of the video signal, wherein said liquid crystal display comprises: a substrate having an insulating surface; an active matrix circuit comprising a plurality of first thin film transistors provided over said substrate; a driver circuit comprising a plurality of second thin film transistors provided over said substrate for driving said active matrix circuit, wherein said n-speed field sequential color signal generation circuit comprises a third thin film transistor over said substrate, wherein at least one of the first thin film transistors, the second thin film transistors and the third thin film transistor has a channel forming region comprising a crystalline silicon, and wherein at least one of the first thin film transistors, the second thin film transistors and the third thin film transistor has a low concentration impurity region adjacent to the channel forming region.