| abstract |
A light emitting device is provided, in which a change of luminance of annOLED is suppressed and a desired color display can be stably performed even if annorganic light emitting layer is somewhat deteriorated or an environmental temperature isnvaried. Separately from a pixel portion for displaying an image, a pixel portion fornmeasuring a driving current of the OLED is provided in the light emitting device. Thendriving current is measured in the pixel portion for measuring the driving current of thenOLED, and a value of the voltage supplied to the above two pixel portions from anvariable power supply is corrected such that the measured driving current has anreference value. With the above-described structure, a reduction of the luminancenaccompanied with the deterioration of the organic light emitting layer can be suppressed.nAs a result, a clear image can be displayed. |