Patent ID: 8665298

Claim:
A method for driving local dimming of a liquid crystal display device comprising: dividing a light analyzing region of a light source of one of a plurality of blocks which divide a backlight unit into at least two symmetric regions considering a form and symmetry of a light emission region, measuring light quantities on sampling points only at one of the at least two symmetric regions, and storing light quantity data per sampling point of the one symmetric region to a memory; analyzing input image data on a block-by-block basis to determine a local dimming value per block; calculating a gain value by light quantity analysis using the light quantity data per sampling point stored in the memory and the local dimming value per block; compensating the input image data using the gain value; and controlling brightness of the backlight unit on the block-by-block basis by using the local dimming value per block, wherein the calculating the gain value includes: calculating a first total light quantity reaching to a corresponding pixel from light sources of blocks neighboring the corresponding pixel using the light quantity data per sampling point, when an entire backlight unit is at the maximum brightness, calculating a second total light quantity reaching to the corresponding pixel from the light sources of the blocks neighboring the corresponding pixel using the local dimming value per block and the light quantity data per sampling point, when the brightness of the backlight unit is controlled on the block-by-block basis according to the local dimming value per block, and calculating the gain value, which is used for compensating the input image data, as a ratio between the first total light quantity and the second total light quantity.