Device and method for displaying image, device and method for supplying power, and method for adjusting brightness of contents

A device for displaying an image, the device comprising:

• a pixel value converter which receives a plurality of color pixel values of the image and converts the plurality of the received color pixel values;
• a display panel which comprises a plurality of color light-emitting devices and drives the plurality of color light-emitting devices according to the plurality of the converted color pixel values;
• a light-emission controller which provides the display panel with a control signal which variably controls driving times of the plurality of color light-emitting devices according to colors of the plurality of color light-emitting devices;
• and
• a controller which controls the light-emission controller to variably adjust a duty ratio of said control signal according to colors of the plurality of color light-emitting devices based on the plurality of the converted color pixel values,
• wherein the controller controls the light-emission controller to control first color light-emitting devices by a first duty ratio and to control second color light-emitting devices by a second duty ratio.