AMOLED display device including compensaton unit and driving method thereof

A display device, comprising:

• a plurality of pixels;
• a plurality of data lines respectively connected to the pixels;
• a compensation unit connected to at least one of the pixels and configured to output degradation information;
• and
• a signal controller configured to control the pixels based at least in part on the degradation information;
• wherein the compensation unit is further configured to measure a leakage current and a difference current of the pixel via one of the data lines,
• wherein the difference current is defined as the difference between a reference current and a current of the pixel measured when a data signal having a predetermined gray is applied to the pixel,
• wherein the compensation unit is further configured to generate the degradation information based on at least one of the leakage current or the difference current, and
• wherein the compensation unit comprises:
• a first capacitor configured to store the leakage current;
• a second capacitor configured to store the difference current;
• a comparator configured to compare the leakage current and the difference current, and output the difference as the degradation information;
• a fifth transistor including a gate electrode configured to receive a third switching control signal, a first electrode connected to a third node, to which the first and second capacitors are connected, and a second electrode;
• and
• a bias circuit connected between the second electrode of the fifth transistor and ground, wherein the bias circuit is configured to control a predetermined current to flow from the third node to the ground when the fifth transistor is turned on,
• wherein each pixel further includes a driving transistor,
• wherein the driving transistor is configured to apply the reference current to the pixel, and
• wherein the predetermined current is substantially the same as the reference current.