Local dimming driving method and device of liquid crystal display device

Abstract

The invention relates to a locak dimming driving method and device of liquid crystal display device. Disclosed herein is the local dimming driving method and device of the 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.

Description

Technical field [0001] The present invention relates to a liquid crystal display (LCD) device, and more particularly, to a local dimming driving method and device of the LCD device, which can prevent color changes caused by grayscale saturation when compensating data, while making Able to perform area dimming. Background technique [0002] In recent years, flat panel display devices such as liquid crystal display (LCD) devices, plasma display panel (PDP) devices, or organic light emitting diode (OLED) devices are mainly used as image display devices. [0003] The LCD device includes: a liquid crystal panel that uses a pixel matrix (the pixel matrix uses the electrical and optical characteristics of liquid crystals with anisotropy of refractive index and dielectric constant) to display images; a drive circuit that drives the liquid crystal panel; and irradiates light to The backlight unit of the LCD panel. By changing the arrangement direction of the liquid crystal according to th...

AI Technical Summary

Problems solved by technology

However, if the input data includes data that allows grayscale saturation, color shifts may occur due to compensation for data that allows grayscale saturation

[0005] For example, when the grayscale value for data "180" or more allows grayscale saturation, if the input R / G / B data "240 / 200 / 180" is multiplied by the gain value "1.5" to multiply the input R / G / B G / B data is changed to output R / G / B data "255 / 255 / 255", then the input data close to red is changed to white output data, resulting in color distortion

If the input R / G / B data "100 / 100 / 200" is multiplied by the gain value "2" to change the input R / G / B data to the output R / G / B data "200 / 200 / 255", then Input data that is close to blue is changed to output data that is close to white, causing color distortion

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