An OLED display device, wherein the OLED display device is configured to be driven by controlling emission times of a pixel depending on gray levels of data of an input image by dividing one frame period into a plurality of subframe periods, separating data of the input image on a per bit basis, mapping the separated data of the input image to the subframe periods, and turning on or off of the pixel on a per subframe basis for representing gray levels of the input image, the display device comprising a self-calibration device for self-calibrating the OLED display device by compensating for a luminance error resulting from a rush current Ix, the rush current Ix being a current instantaneously and strongly generated when the pixel in an off-state is turned on, wherein the self-calibrating device comprises: a measurement unit configured to measure a current or luminance of a pixel for one frame period, wherein the measurement unit is further configured to drive the pixel with a predetermined gray level having a predetermined number of turning on-operations of the pixel in the one frame period; a luminance error calculation unit configured to calculate the rush current Ix of the pixel emitting light based on the measured current or luminance value of the pixel and a predetermined current of the pixel at each gray level and to calculate a luminance error of the pixel based on the rush current; and a luminance error compensation unit configured to reduce an emission time of a subframe period or change a turned-on subframe period in the mapping of the separated data of an input image to the subframe periods to compensate the calculated luminance error, wherein in changing the turned-on subframe period in the mapping of the separated data of the input image to the subframe periods the luminance error compensation unit is adapted to switch values of gray levels of data at gray levels, in which a luminance reversal of the gray levels occurs due to the luminance error of the pixel, wherein in the OLED display device the luminance reversal of a gray level occurs when the rush current Ix causes the luminance of a pixel for said gray level to be greater than the luminance of the pixel for a higher gray level. a measurement unit configured to measure a current or luminance of a pixel for one frame period, wherein the measurement unit is further configured to drive the pixel with a predetermined gray level having a predetermined number of turning on-operations of the pixel in the one frame period; a luminance error calculation unit configured to calculate the rush current Ix of the pixel emitting light based on the measured current or luminance value of the pixel and a predetermined current of the pixel at each gray level and to calculate a luminance error of the pixel based on the rush current; and a luminance error compensation unit configured to reduce an emission time of a subframe period or change a turned-on subframe period in the mapping of the separated data of an input image to the subframe periods to compensate the calculated luminance error, wherein in changing the turned-on subframe period in the mapping of the separated data of the input image to the subframe periods the luminance error compensation unit is adapted to switch values of gray levels of data at gray levels, in which a luminance reversal of the gray levels occurs due to the luminance error of the pixel, wherein in the OLED display device the luminance reversal of a gray level occurs when the rush current Ix causes the luminance of a pixel for said gray level to be greater than the luminance of the pixel for a higher gray level.