Organic light emitting display device

An organic light emitting display device comprising:

• a display panel including a plurality of pixels, which are respectively formed in a plurality of pixel areas defined by crossings of a plurality of gate lines and a plurality of data lines, a plurality of sensing lines, and a plurality of second gate voltage lines connected to the plurality of pixels, wherein each of the plurality of pixels includes at least one transistor including first and second gate electrodes which overlap each other with a semiconductor layer therebetween;
• a panel driver to drive the display panel in a display mode or a sensing mode, to sense a threshold voltage of the at least one transistor included in each of the plurality of pixels through the plurality of sensing lines to generate a sensing data in the sensing mode, and generate a second gate voltage data based on the sensing data of each pixel in the display mode;
• and
• a voltage supply unit to generate a second gate electrode voltage corresponding to the second gate voltage data supplied from the panel driver, and apply the second gate electrode voltage to the second gate electrode of the at least one transistor, included in each pixel, through a corresponding second gate voltage line.