Light-emitting device

摘要

There is provided an EL light-emitting device with less uneven brightness. When a drain current of a plurality of current controlling TFTs is Id, a mobility is mu, 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 DeltaVth, and a difference in emission brightness of a plurality of EL elements is within a range of ±n %, a semiconductor display device is characterized in that 1 $\begin{array}{c}A=\frac{2Id}{\mathrm{mu}*C_0}\\ \frac{A}{{\left({\mathrm{Vgs}}_{\left(\max \right)}-\mathrm{Vth}\right)}^2}\leqq \frac{W}{L}\leqq {\left(\sqrt{1+\frac{n}{100}}-1\right)}^2*\frac{A}{\mathrm{Delta}{\mathrm{Vth}}^2}\\ \&LeftBracketingBar;\mathrm{Delta}\mathrm{Vth}\&RightBracketingBar;\leqq \left(\sqrt{1+\frac{n}{100}}-1\right)*\sqrt{A*L/}\end{array}$