Patent ID: 8421737

Claim:
A scanning line driving circuit comprising: a first transistor having a source electrode connected to a power supply and a drain electrode connected to a scanning line; a second transistor having a source electrode connected to the scanning line and a drain electrode connected to a clock signal line and having a conductivity type identical to that of the first transistor; a third transistor having both drain and gate electrodes connected to a gate electrode of the first transistor and a source electrode supplied with a driving signal of the first transistor; and a fourth transistor having a source electrode connected to the gate electrode of the first transistor, a gate electrode connected to the source electrode of the third transistor, and a drain electrode connected to an external control signal line used for causing the scanning line in a floating state, wherein each of the first, second, third, and fourth transistors are of an identical conductivity type, and wherein the gate electrode of the first transistor, a gate electrode of the second transistor, and the clock signal line are supplied with signals necessary for a shift operation to function as a shift resistor.