A driving controller includes an image conversion circuit configured to convert an image signal to an image data signal including active data and blank data, a still image determination circuit configured to output a flag signal of an active level when the image signal is a still image, an operation mode determination circuit configured to output an operation mode signal indicating a low frequency mode when the flag signal is the active level, and to output an operation mode signal indicating an image transition mode when the flag signal is changed from the active level and an inactive level, and a blank voltage determination circuit configured to output a blank voltage signal corresponding to a first gray scale during the low frequency mode, and a blank voltage signal corresponding to a second gray scale during the transition mode, wherein the blank data corresponds to the blank voltage signal.