| 摘要 |
<P>PROBLEM TO BE SOLVED: To exclude brightness dispersion due to the temperature variation of an organic EL element, by controlling the electric current supplied to the organic EL element, according to the variation in the voltage across both electrodes of the organic EL element in an organic EL element lighting device. <P>SOLUTION: The lighting device 1 includes a control circuit 6 for controlling the electric current supplied to a lamp part 10 having the organic EL element, and a voltage and current detecting part 4 for detecting the voltage across the both electrodes of the organic EL element of the lamp part 10. When a voltage value detected by the voltage and current detecting part 4 exceeds a set voltage value, an element temperature is low and the brightness is low, and the control circuit 6 increases the current supplied to the organic EL element so as to increase the brightness. When the detected voltage value is lower than the set voltage value, the element temperature is high and the brightness is high, and the electric current supplied to the organic EL element is reduced and the brightness is reduced. <P>COPYRIGHT: (C)2011,JPO&INPIT |
