Patent ID: 8139020

Claim:
A liquid crystal display device comprising: a liquid crystal panel configured to display an image from image signals; a backlight divided into regions and disposed on the back side of the liquid crystal panel, the backlight comprising light sources in the respective regions, the light sources positioned to emit light into the liquid crystal panel, and the backlight having a structure in which light emitted from each of the light sources of the plurality of regions is allowed to leak to regions other than the respective light source region; a maximum gradation detector configured to detect, at predetermined intervals, a first maximum gradation of each of regional image signals displayed on regions of the liquid crystal panel that correspond to regions of the backlight device; an image gain calculator configured to determine a gain value based on a value determined by dividing a second maximum gradation by the first maximum gradation, the second maximum gradation being a possible maximum gradation of the regional image signal and determined based on the number of bits of the regional image signal; a multiplier configured to multiply a regional image signal by the gain obtained by the image gain calculator, and to output image signals for display on the liquid crystal panel; and an emission luminance calculator configured to determine the second emission luminance by multiplying a first emission luminance by a first coefficient, wherein the first emission luminance is the luminance from each region of the backlight obtained by multiplying the maximum luminance from the light source by the inverse number of the gain obtained by the image gain calculator, wherein the first coefficient is determined from the amount of light that leaks out of adjacent regions and the regions in the vicinity of adjacent regions into a given region, and wherein the second emission luminance is the luminance of light that each of the light sources of the plurality of regions of the backlight independently emits to obtain the first emission luminance.