Patent ID: 8400392

Claim:
A backlight control apparatus for controlling a backlight used in a display, the backlight having a lighting area that includes a plurality of blocks, each of the plurality of blocks containing a light source which controls a backlight luminance, the backlight luminance for each of the plurality of blocks individually allowed to change based at least in part on an image signal corresponding to an image to be displayed by the display, the apparatus comprising: at least one backlight control circuit to receive the image signal and calculate the backlight luminance of each block based at least on the image signal so that an absolute value of a difference between a backlight lighting ratio and 1 is at or below a first value, and to control the backlight so as to yield the calculated backlight luminances of the respective blocks, the backlight lighting ratio being the ratio between backlight set values of neighboring blocks, wherein the light source of each of the plurality of blocks receives at least one control signal from the at least one backlight control circuit, the at least one control signal controlling the backlight luminance of an associated block.