Display device and driving method thereof

A display device comprising:

• a display unit including a plurality of pixels connected to a plurality of scan lines and a plurality of data lines, the plurality of pixels emitting light according to corresponding image data;
• a dummy pixel connected to a dummy scan line and a dummy data line, the dummy pixel including a first organic light emitting element and each pixel including a second organic light emitting element;
• and
• a compensation image data generator configured to:
• calculate a compensation amount according to an accumulation light emitting time of the first organic light emitting element;
• detect the compensation amount corresponding to each accumulation light emitting time of the plurality of second organic light emitting elements using a decreasing amount of luminance corresponding to a resistance of the first organic light emitting element according to an accumulation light emitting time of the first organic light emitting element of the dummy pixel;
• and
• compensate the corresponding image data according to the detected compensation amount.