Patent ID: 8531385

Claim:
A driving method for local dimming of a Liquid Crystal Display (LCD) device, comprising: determining a dimming value of each of a plurality of local dimming blocks into which a backlight unit is divided to be driven on a block basis by analyzing input image data on a block basis; detecting a high gray area concentrated with high gray levels from each local dimming block based on the analysis of the input image data, and generating position information about the high gray area according to a distance between the high gray area in the block and an adjacent block; compensating the dimming value of each of the plurality of local dimming blocks by spatial filtering using a spatial filter having a different filter size or different filter coefficients for local dimming blocks according to the position information about the high gray area in the local dimming block; and calculating a first gain value on a pixel basis using the dimming values of the local dimming blocks and an optical profile of a preset light source and compensating the input image data by applying the first gain values of pixels to the input image data, wherein the first gain value is calculated as a ratio of a second total light intensity to a first total light intensity, wherein the first total light intensity is to calculate a total light intensity that reaches to each pixel using the optical profile in the case where the backlights are all at a maximum luminance and the second total light intensity is to calculate a total light intensity that reaches the pixel using the optical profile and the local dimming values of the blocks in the case where the backlight luminance is controlled on a block basis by local dimming.