Display device determining a global dimming value based on an obtained motion sum value

A method of operating a display device including a liquid crystal display panel and a backlight including a plurality of backlight blocks configured to provide a light to the liquid crystal display panel, wherein each of the plurality of backlight blocks includes a plurality of light sources, wherein the method comprises:

• performing a local dimming process to determine a local dimming value for each of a plurality of backlight blocks based on a plurality of local images constituting an entire image to be displayed by the liquid crystal display panel;
• obtaining a plurality of motion values corresponding to each of the plurality of local images,
• obtaining a motion sum value of the entire image by summing the plurality of obtained motion values,
• determining, subsequent to the local dimming process, a uniform global dimming value for the plurality of backlight blocks based on the obtained motion sum value, wherein the uniform global dimming value is a duty of a signal for controlling the plurality of light sources;
• obtaining a luminance compensation value corresponding to the determined uniform global dimming value, wherein the luminance compensation value is a value of a current flowing through the plurality of light sources;
• and
• increasing the value of the current as the duty decreases.