Display device and method of driving the same, and display system

Disclosed is a method of driving a display device for a device provided with a scanning line drive circuit which sequentially selects by line a plurality of scanning signal lines; and a signal line drive circuit provided with an output circuit that allows current to flow, which through the output circuit and a plurality of data signal lines sequentially supplies a data signal to a pixel on the scanning signal line that is selected; the method of driving the display device comprising: a synchronization signal output step wherein a horizontal synchronization control signal which has a period shorter than the period of an inputted horizontal synchronization signal, and a vertical synchronization control signal are output on the basis of the inputted horizontal synchronization signal and the inputted vertical synchronization signal; a scanning step wherein a data signal is supplied to all the pixels on the plurality of scanning signal lines within a vertical interval as defined by the vertical synchronization control signal; and a capacity controlling step wherein within a vertical interval, the capacity of the output circuit is reduced after the scanning step has completed.