PURPOSE: A display device is provided to display an image suitable for the property of a display panel by modulating the output voltage of an image data signal outputted from a data driver. CONSTITUTION: A data driver(DDRV) modulates source data into a modulated data according to modulation data from outside. The data driver converts modulated data signal into an image data signal corresponding to a gamma voltage The data driver add and subtract the voltage level of the modulated data signal according to the modulation signal. A data modulation part(55) modulates a source data signal into the modulated data signal. A conversion unit(56) converts the modulated data signal into the image data in response to the gamma voltage.
