ACTIVE MATRIX TYPE OLED DISPLAY DEVICE AND ITS DRIVING CIRCUIT

PROBLEM TO BE SOLVED: To provide an OLED(organic light emitting diode) driving pixel circuit having satisfactory display performance. SOLUTION: In this pixel circuit, four transistors are constituted in a pixel and after first and second scanning lines GL1, GL2 which are connected respectively to the gate electrode of a second transistor MSH and that of a third transistor MWR are made active and the gate electrode and the drain electrode of a first transistor MDR are made to be in conduction state via the second transistor MSH and a current having a value corresponding to a video signal is made to flow from a power source to a signal line through the first and third transistors MDR, MWR and the first scanning line GL1 is made inactive, the second scanning line GL2 is made inactive and thereafter a third scanning line GL3 which is connected to the gate electrode of a fourth transistor MCH is made active and a current having a value corresponding to the video signal is made to flow through an OLED through the fourth transistor MCH.