Local dimming driving method and device of liquid crystal display device

摘要

Disclosed herein is a local dimming driving method and device of a Liquid Crystal Display (LCD) device, which is capable of preventing color change due to gray scale saturation when data is compensated while enabling local dimming. The local dimming driving method of the LCD device includes detecting maximum values per pixel from input image data, analyzing the maximum values per pixel on a block-by-block basis, and determining local dimming values per block according to the analysis result, calculating a first gain value using the local dimming values per block, calculating a maximum gain value per pixel using the maximum value per pixel as a second gain value, selecting a smaller value of the first and second gain values as a final gain value, compensating the input image data using the final gain value, and controlling luminance of a backlight unit on the block-by-block basis using the local dimming value per block.

主权项

1. A local dimming driving method of a liquid crystal display device, the local dimming driving method comprising:
detecting maximum values per pixel from input image data, analyzing the maximum values per pixel on a block-by-block basis, and determining local dimming values per block according to the analysis result; calculating a first gain value using the local dimming values per block; calculating a maximum gain value per pixel using the maximum value per pixel as a second gain value; selecting a smaller value of the first and second gain values as a final gain value; compensating the input image data using the final gain value; and controlling luminance of a backlight unit on the block-by-block basis using the local dimming value per block, wherein the calculating of the first gain value includes: calculating a first total light quantity per pixel by detecting and summing the quantity of light reaching each pixel from a predetermined light profile of a light source, when the overall luminance of the backlight unit has a maximum value; calculating a second total light quantity per pixel by summing the quantity of light reaching each pixel from the predetermined light profile of the light source multiplied by the local dimming values when the luminance of the backlight unit is controlled by local dimming on the block-by-block basis; and calculating the first gain value by a ratio of the first total light quantity to the second total light quantity on a pixel-by-pixel basis.