| 摘要 |
PROBLEM TO BE SOLVED: To obtain the desired number of gradation without increasing power consumption. SOLUTION: This organic EL(electroluminescence) display device is provided with first and second power source terminals VSS, VDD, an organic EL element 16 which is connected between these power source terminals VSS, VDD and which emits light with luminance corresponding to the conduction period of a constant current, a driving transistor 17 which is connected in series with the organic EL element 16 and which switches a constant current made to flow through the EL element 16 and a control part controlling the driving transistor 17 based on a video signal. In particular, the control part includes bias circuits 24, 25 which superpose a bias voltage changing continuously in each frame on the video signal and supplies them to the gate of the driving transistor element and sets the ratio of the conduction period and the non-conduction period of the driving transistor element by the transition of a gate-to-source voltage with respect to the threshold voltage of the driving transistor element. |
