Patent ID: 7391404

Claim:
A computer having an active matrix display device comprising: a differential circuit toned over a substrate and including x (x is a natural number not less than 2) first-side thin film transistors which have a common gate electrode potential and to which a signal is inputted, and x second-side thin film transistors which have a common gate electrode potential; and a current mirror circuit formed over said substrate and including y (y is a natural number not less than 2) first-side thin film transistors and y second-side thin film transistors, which have a common gate electrode potential, the gate electrodes of the y first-side thin film transistors being connected to source or drain of the y first-side thin film transistors, wherein each of said thin film transistors in said differential circuits and said mirror circuit comprises a crystalline semiconductor film over said substrate having an insulating surface, said crystalline semiconductor film having at least a channel and a width of said channel is 100 μm or less.