Patent ID: 7079126

Claim:
Method for power level control in a display device having a plurality of display elements corresponding to the pixels of a picture, wherein a power level mode selection process is used for increasing the peak white enhancement factor of the display, in which the power value of a video picture is measured and a corresponding power level mode is selected for controlling the display contrast, wherein a picture is divided in a number of blocks, wherein in each block the video levels or values derived from the video levels of the colour components of the pixels are summed up in order to determine the local power values for the picture, wherein a local temperature estimation is performed for the corresponding blocks of the display based on said local power values and the previously estimated local temperature values according to the formula: T ( i,j ) t =T ( i,j ) t-1 +a·P ( i,j ) t −D where T(i,j) t is the new estimated local temperature of a block, where T(i,j) t-1 is the previous estimated local temperature of a block, where a·P(i,j) t is the power being dissipated in the block and D is the power dissipation corresponding to the heat being given to the environment, wherein in the estimated local temperature values the maximum local temperature in the display is selected, wherein a further step of maximum power level limit determination is performed based on the maximum local temperature, and wherein the power level limit is used to restrict the range of selectable power level modes in the power level mode selection process to power level modes having a power level below or equal to said power level limit.