Patent ID: 6583776
Filing Date: 2003-06-24
Classification: G09G,H01L

Abstract:
A light-emitting device including:a plurality of pixels, said plurality of pixels including a plurality of switching TFTs, a plurality of current controlling TFTs, and a plurality of EL elements, an emission brightness of the EL elements being controlled by video signals inputted to gate electrodes of the plurality of current controlling TFTs through the plurality of switching TFTs, each of said plurality of current controlling TFTs including an active layer, a gate insulating film on the active layer, and a gate electrode on the gate insulating film, said active layer including a source region, a drain region, and a channel forming region provided between the source region and the drain region, and wherein a drain current of each of the plurality of current controlling TFTs when the emission brightness of the EL elements becomes maximum is Id, a mobility is &mgr;, a gate capacitance per unit area is Co, a maximum gate voltage is Vgs(max), a channel width is W, a channel length is L, an average value of a threshold voltage is Vth, a deviation from the average value of the threshold voltage is &Dgr;Vth, and a difference in the emission brightness of the plurality of EL elements is within a range of Â±n%, A=2&it;IdÎ¼*C0A(Vgs(max)-Vth)2&LessFullEqual;WL&LessFullEqual;(1+n100-1)2*AÎ”&it;â€ƒ&it;Vth2.