LIQUID CRYSTAL DISPLAY DEVICE AND BACKLIGHT CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To reduce the power consumption of a backlight while suppressing generation of a luminance step in a region boundary. SOLUTION: An in-region gradation value-detecting part 102 detects gradation levels of an input video signal with respect to each sub-region and removes gradation levels of pixels within a predetermined higher range (m%) from the brightest gradation level in the sub-region to detect a maximum in-region gradation level Pa. A boundary gradation value-detecting part 103 removes gradation levels of pixels within a predetermined higher range (n%) from the brightest gradation level with respect to a pixel group that belongs to a region boundary portion in the sub-region to detect a maximum boundary gradation level Pb. A backlight control value-deciding part 104 selects higher one of the in-region maximum gradation level Pa and the maximum boundary gradation level Pb as a maximum gradation level Pc of the sub-region and decides a backlight control value K based on the ratio between the maximum gradation level Pc and an upper limit value Pmax of gradation levels. COPYRIGHT: (C)2011,JPO&INPIT