Patent ID: 8305370

Claim:
An organic light emitting display, comprising: a pixel unit including a plurality scan lines configured to provide scan signals, a plurality of emission control lines configured to provide emission control signals, a plurality of data lines configured to provide data signals, and a plurality of pixels coupled to the scan lines, the emission control lines, and the data lines; a scan driver configured to sequentially generate and apply the scan signals and the emission control signals to the plurality of scan lines; a data driver configured to generate and apply the data signals to the data lines; an optical sensor configured to generate an optical sensing signal corresponding to an intensity of ambient light; a first controller configured to select a gamma value corresponding to the optical sensing signal, and output a gamma compensation signal corresponding to the selected gamma value to control a gradation voltage of the data signal; a second controller configured to compare the optical sensing signal with a previously set reference value, generate a selection signal in response thereto, and provide changed image data to the data driver, the changed data being obtained by changing input image data in accordance with the selection signal; a third controller configured to obtain and apply a scaling factor to the input image data through extracted features related to the input image data and a scale ratio obtained from the extracted features, and provide scaled image data to the data driver; and a fourth controller configured to provide a luminance control signal for controlling a pulse width of the emission control signal to the scan driver.