| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that an organic EL display device cannot perform even 64-gradation display because the V-I characteristic comes off the saturation area of the Vds-Ids characteristic of a driving transistor due to deterioration of EL elements, and their crossing area becomes small. <P>SOLUTION: The organic EL display device is provided with EL elements 7 having a light emitting layer between an anode and a cathode, thin film transistors 6 for driving the EL elements 7, a 1st power source 12 for applying the power source voltage of one polarity and connected to the side of the thin film transistors 6, and a 2nd power source 13 for applying the power source voltage of the opposite polarity and connected to the side of the EL elements 7. The organic EL display device varies the power source voltage of the 2nd power source 13 in correspondence with an integrated value of the display time of the light emitting layer; compensates the deterioration in brightness of the light emitting layer; and is thereby able to perform displaying gradation even if the light emitting material is deteriorated in brightness. <P>COPYRIGHT: (C)2004,JPO |
