Abstract: Video pictures have different picture formats so that sidebars are displayed on the display device. Consequently, burning effects are different between used and unused areas of the screen. Therefore, the unused areas of the display device are driven with a signal which is varied in accordance with the video signal. Preferably, at least a part of the active area of the screen is analysed and a medium value of such analysed area is used for driving the unused areas. As a result, the burning effect affects the used and unused areas equally and the sidebars are less disturbing since they are adapted to the video picture.