Patent ID: 7728526

Claim:
An organic light emitting display device, comprising: a photo sensor adapted to: sense a brightness of ambient light; determine a pulse width of an emission control signal corresponding to the brightness of the ambient light; and output a gamma compensation coefficient corresponding to the sensed brightness of the ambient light and a user selected brightness; a gamma compensation circuit adapted to adjust a magnitude of a voltage between a plurality of gradation voltages according to the output gamma compensation coefficient; a scan driver adapted to: adjust the pulse width of the emission control signal according to the determination of the pulse width of the emission control signal by the photo sensor; and generate and transfer a scan signal and the emission control signal to a pixel portion of the organic light emitting display device; a data driver adapted to generate and transfer a data signal to the pixel portion; and the pixel portion comprising a pixel adapted to: emit light according to the data signal, the scan signal, and the emission control signal; and display an image corresponding to the user selected brightness.