Liquid crystal display device and method for local dimming driving using spatial filter of the same

摘要

A liquid crystal display device capable of improving a contrast ratio and of reducing a halo phenomenon with low power consumption and a method for local dimming driving the same are disclosed. A method for local dimming driving a liquid crystal display includes determining a local dimming value for each of light-emitting blocks based on analyzing input image data by the unit of light-emitting block provided in a backlight unit; determining a halo degree by analyzing a total light quantity of black pixels having black gradations in the input image data; adjusting the number of spatial filtering repetitions based on the determined halo degree; compensating the local dimming value by performing spatial filtering for the local dimming value an adjusted number of times; and controlling brightness of the backlight unit for each of the blocks by using the compensated local dimming value.

主权项

1. A method for local dimming driving a liquid crystal display comprising:
determining a local dimming value for each of a plurality of light-emitting blocks based on analyzing input image data by the unit of light-emitting block provided in a backlight unit; determining a halo degree by analyzing a total light quantity of black pixels having black gradations in the input image data; adjusting the number of spatial filtering repetitions based on the determined halo degree; compensating the local dimming value by performing spatial filtering for the local dimming value an adjusted number of times; controlling brightness of the backlight unit for each of the blocks by using the compensated local dimming value; calculating a gain value for each of the blocks by using the total quantity of lights reaching each of the pixels from each of the blocks of the backlight unit and by using the local dimming value for each of the blocks; and compensating the input image data by using the gain value; wherein the determining of the halo degree comprises; selecting the black pixels from an input image, selecting a total light quantity for the selected black pixels from the total light quantities for the pixels and storing the total light quantity by at least frame units, calculating an average of the total light quantities for the black pixels by the frame units and a halo indicator representing the halo level in proportion to the average, and determining a halo level based on a range of the halo indicator sizes.