Patent ID: 7277070

Claim:
A method of driving a light emitting device comprising: selecting a first gate signal line electrically connected with a first gate signal line driver circuit to turn ON first and second TFTs; flowing a first current corresponding to an image signal into a source signal line, the first TFT, and a third TFT, wherein a voltage between a gate electrode of the third TFT and a source region of the third TFT is V GS ; de-selecting the first gate signal line to turn OFF the first and second TFTs, wherein the V GS of the third TET is maintained while the first and second TFTs are in an OFF state; selecting a second gate signal line electrically connected with a second gate signal line driver circuit to turn ON a fourth TFT; and flowing a second current corresponding to the V GS of the third TFT into an EL element through the third and fourth TFTs, wherein the third TFT is operated in a saturation range during a period when the first current or the second current flows into the third TET.