Display device and driving method thereof

A method for driving a display device that changes a refresh rate of an input image to be displayed on a display panel, the method comprising:

• determining the refresh rate of the input image;
• and
• during a display interval where the input image is displayed on the display panel, transmitting an instruction signal corresponding to the refresh rate of the input image to a power supply such that a reference voltage to be output from the power supply varies corresponding to the refresh rate of the input image,
• wherein the reference voltage is applied to reference voltage lines of the display panel.

A display device comprising:

• a display panel configured to display an input image in a display area, the display area including a plurality of data lines, a plurality of gate lines, a plurality of reference voltage lines, and a plurality of sub-pixels are disposed;
• a data driver electrically connected to the data lines and the reference voltage lines;
• and
• a gate driver electrically connected to the gate lines,
• wherein:
• each of the sub-pixels includes:
• a light-emitting element;
• and
• a driving transistor configured to drive the light-emitting element;
• and
• when a refresh rate of the sub-pixels is higher from a first refresh rate to a second refresh rate, a gate-source voltage of the driving transistor is greater.