Patent ID: 8619010

Claim:
An image display device having a function of controlling a luminance of a backlight, the image display device comprising: a backlight including a plurality of light sources that emit lights which are a plurality of primary colors; a display panel including a plurality of sets of a plurality of display elements, each set displaying one pixel in a plurality of colors by allowing lights from the light sources to be transmitted therethrough; a light-emission luminance calculating unit that divides an input image into a plurality of areas and obtains light-emission luminance data based on the input image, the input image including a plurality of pixels, each of which is formed by a plurality of colors, the light-emission luminance data representing luminances upon light emission of the light sources provided for the respective areas; a display luminance calculating unit that determines display luminances based on the light-emission luminance data for the respective areas, the display luminances being highest luminances obtained by the respective display elements; a display data calculating unit that obtains display data for controlling light transmittances of the display elements, based on the input image and the display luminances determined by the display luminance calculating unit; a panel drive circuit that outputs, based on the display data, signals for controlling the light transmittances of the display elements to the display panel; and a backlight drive circuit that outputs, based on the light-emission luminance data, signals for controlling luminances of the light sources to the backlight, wherein when any of luminances for the respective colors forming a pixel in the input image is higher than a corresponding display luminance, the display data calculating unit obtains the display data based on values obtained by dividing each of the luminances for the respective colors forming the pixel in the input image by a same value, so that a light transmittance of a corresponding display element is 1 or less.