Organic light emitting display and driving method thereof

An organic light emitting display, comprising:

• a pixel portion comprising a plurality of pixels, configured to receive a plurality of scan signals, a plurality of emission control signals, and a plurality of data signals in order to display images according to video data, wherein each pixel is configured to generate light for a duration during each frame, wherein the duration is determined by at least a portion of the received signals;
• a data driver configured to generate and transfer the plurality of data signals to the pixel portion using the video data;
• a scan driver configured to transfer the plurality of scan signals and the plurality of emission control signals to the pixel portion;
• an optical sensor configured to detect ambient light and to generate a sensing signal to control luminance of the pixel portion according to the detected ambient light;
• a current controller configured to, as a result of the ambient light having a detected luminance greater than a level, cause the pixels to generate light for a reduced duration during each frame, wherein the reduced duration is determined according to a sum of the video data inputted during each frame;
• and
• a gamma compensation circuit, configured to provide gamma correction according to one of a plurality of selectable registers, wherein the registers are selected according to the ambient light detected by the optical sensor,
• wherein the sensing signal controls both the scan driver and the register selection, and wherein the sensing signal controls the scan driver via the current controller while controlling register selection for the gamma compensation circuit.