Organic light emitting diode display and method for driving the same

An organic light emitting diode display, comprising:

• a display panel comprising a plurality of pixels arranged in a matrix at intersections of gate line portions and data line portions and each having an organic light emitting diode and a driving TFT that controls amount of current flowing in the organic light emitting diode;
• a memory that stores compensation data including a first compensation data and second compensation data;
• a timing controller that modulates input digital video data based on the compensation data and generates modulated data;
• and
• a data driving circuit that, during compensation driving, generates the compensation data to compensate for a difference of the deterioration between the organic light emitting diodes in the display panel and a difference of the deterioration between the driving TFTs by supplying first and second sensing voltages to the pixels and sampling the threshold voltage of the organic light emitting diodes and the threshold voltage of the driving TFTs, which are fed back from the pixels, and that, during normal driving, converts the modulated data into a data voltage and supplying the data voltage to the pixels,
• wherein the compensation driving is sequentially performed during a first period for precharging a data line of the data line portions with a high potential driving voltage, a second period for charging the data line with the first sensing voltage, a third period for floating the data line and then discharging the first sensing voltage on the data line via the organic light emitting diode, a fourth period for sampling a first sensing voltage on the data line remained after the discharging with the threshold voltage of the organic light emitting diode, a fourth period for charging the data line with the second sensing voltage, a sixth period for floating the data line and then charging the data line with the threshold voltage of the driving TFT higher than the second sensing voltage, and a seventh period for sampling the threshold voltage of the driving TFT on the data line,
• where the normal driving is sequentially performed during an eighth period for supplying the data voltage and a ninth period for light emission of the organic light emitting diode, and
• wherein the data driving circuit includes:
• a sensing voltage supply unit that generates the high potential voltage during the first period, the first sensing voltage during the second period, and the second sensing voltage during the fifth period;
• a sampling unit that samples the threshold voltage of the organic light emitting diode during the fourth period and the threshold voltage of the driving TFT during the seventh period;
• an ADC that analog-digital converts the sampled threshold voltage of the organic light emitting diode to generate the first compensation data during the fourth period, and the sampled threshold voltage of the driving TFT to generate the second compensation data during the seventh period;
• and
• a data voltage generator that converts the modulated data into the data voltage during the eighth and ninth periods.