Signal line driver circuit and light emitting device and driving method therefor

A display device comprising:

• a pixel portion over a substrate, the pixel portion comprising a pixel;
• a first shift register over the substrate;
• and
• a second shift register over the substrate, the second shift register being between the pixel portion and the first shift register,
• wherein the pixel comprises a first transistor, a second transistor, a third transistor, a fourth transistor, a capacitor and a light emitting element,
• wherein one of a source and a drain of the first transistor is directly connected to a signal line,
• wherein the other of the source and the drain of the first transistor is directly connected to one of a source and a drain of the second transistor,
• wherein the other of the source and the drain of the second transistor is directly connected to a current line,
• wherein one of a source and a drain of the third transistor is directly connected to the other of the source and the drain of the first transistor,
• wherein the other of the source and the drain of the third transistor is electrically connected to the light emitting element,
• wherein a gate of the third transistor is directly connected to one of a source and a drain of the fourth transistor,
• wherein a first terminal of the capacitor is directly connected to the gate of the third transistor, and
• wherein a gate of the fourth transistor is directly connected to a first scan line.