Patent ID: 8054254

Claim:
An organic light emitting display device for displaying an image and having a plurality of scan lines, a plurality of light emission control lines and a plurality of data lines, the organic light emitting display device comprising: a display area including a plurality of pixels coupled to the scan lines, the light emission control lines and the data lines; a scan driver electrically coupled to the display area through the scan lines and the light emission control lines; a data driver electrically coupled to the display area through the data lines; an optical sensor for generating an optical sensor signal corresponding to brightness of ambient light; a first luminance control unit for generating a pulse width of a brightness control signal in accordance with the optical sensor signal and for supplying a selection signal; a second luminance control unit for generating a fluctuated value for the pulse width of the brightness control signal in accordance with data of one frame of the image; and a luminance control signal generation unit for generating a luminance control signal for controlling the scan driver in accordance with the pulse width of the brightness control signal and the fluctuated value, wherein the second luminance control unit is turned on or off according to the selection signal supplied from the first luminance control unit.