Lg Display Co., Ltd.

Kyungjoon Kwon

Cheon Heo

Heewon Ahn

Byoungchul Cho

Changkyun Park

Dongwoo Kim

Junghwan Lee

HeeJung Hong

Daeho Cho

EuiYeol Oh

Injae Chung

Sungjo Koo

Kyohyuck Choo

ByeongHyeon Na

SeongGyun Kim

Sihoon Lee

The present disclosure provides method and device for dimming the backlight of an LCD. A number of pixels at each grayscale level of an input image is determined. The determined number of pixels at each grayscale level is accumulated to generate an accumulated distribution of the number of pixel and the accumulated distribution is filtered. A threshold grayscale level at which the filtered accumulated distribution exceeds a threshold value is determined. A scaling factor is determined based on the threshold grayscale level. The grayscale level of pixels of the input image having a grayscale level lower than or equal to the threshold grayscale level are up-scaled based on the scaling factor, the grayscale value of pixels of the input image having a grayscale level greater than the threshold grayscale level are set to have a predetermined clipping grayscale level, and the LCD backlight is dimmed based on the scaling factor.

Method and device for clipping a gray scale level of pixels during the dimming of the backlight of a display device

Provided are a display device and an image processing method thereof. In an embodiment, the display device includes a display panel including a plurality of pixels formed of red, green, blue, and white sub pixels, and an image processing unit for converting a three-color input image supplied to the red, green, blue, and white sub pixels into four-color image data and outputting an output image by applying a final gain calculated using a frame gain, a pixel gain, and a block gain of the pixels. The display device also includes a timing controller for outputting the output image from the image processing unit to the display panel. The block gain may be calculated using scaled versions of luminance values determined by converting a luminance of the three-color input image and position information of the pixels.

Display device and image processing method thereof

Provided are a display device and an image processing method thereof. The display device according an embodiment includes a display panel including pixels formed of red, green, blue, and white sub pixels, an image processing unit that converts a three-color input image supplied to the red, green, blue, and white sub pixels into four-color image data, calculates a color contrast ratio using a luminance weight and a hue weight by scaling luminance and hue values of the input image, and outputs an output image by considering the color contrast ratio, and a timing controller which aligns and outputs the output image from the image processing unit.

Provided are a timing controller and a display device including the same. The timing controller in one embodiment includes a bit selecting unit, an error calculating unit, and a dithering unit. The bit selecting unit is configured to fix an m bit data value of n+m bit input image data for a plurality of subpixels as a fixed data value, where n and m are integers. The error calculating unit is configured to calculate an error between the fixed data value fixed by the bit selecting unit and the m bit data value of the input image data before fixed by the bit selecting unit. The dithering unit is configured to generate n bit output image data dithered to correct the error.

Timing controller and display device including the same

A data clipping method using red, green, blue and white data, and a display device using the same are disclosed. Red (R), Green (G), Blue (B), and White (W) data are modulated by multiplying clipped data of an input image by a gain, a luminance increment is created based on the result of subtracting the clipped data from the modulated RGB data, and the luminance increment is added to the W data to be written to a W sub-pixel.

Data clipping method using red, green, blue and white data, and display device using the same

An apparatus generates pixel data in a display. RGB pixel data is received corresponding to a target pixel of an image. A local adaption level is determined for the RGB pixel data representing perceived brightness of the RGB pixel data. The local adaption level is modified to generate a modified local adaption level. A transfer curve is generated based on the modified local adaption level and the transfer curve is applied to the input RGB pixel data. A local dimming value is generated to drive a light source driver of the display based on RGB pixel data for each of the pixels in the local dimming block and RGBW pixel data for each of the pixels in the local dimming block.

Method and device for expanding a dynamic range of display device

A method of compensating for pixel data includes extending a side portion and a corner portion of a real screen to set an virtual screen, setting dimming values of the virtual screen using dimming values of the real screen, calculating an amount of light of each of pixels on the real screen using the dimming values of the virtual screen mapped to a predetermined analysis area, and multiplying the amount of light of each pixel by a gain of each pixel to modulate pixel data.

Method of compensating for pixel data and liquid crystal display

A liquid crystal display includes a liquid crystal display panel, a backlight unit including a plurality of light sources, the backlight unit providing light to a back surface of the liquid crystal display panel, a backlight driving circuit that individually drives a plurality of previously determined blocks each including the light sources based on a dimming value of each of the blocks, and a local dimming control circuit that calculates a pixel gain value compensating for a luminance reduction resulting from the dimming value of each block and corrects the pixel gain value based on a grayscale saturation level of each block.

Liquid crystal display and local dimming control method thereof

An over-driving circuit for a display device having a display panel includes a first 4-color data generation module configured to generate output 4-color data of the previous frame based on 3-color data and a gain of the previous frame, and to generate output 4-color data of the current frame based on 3-color data and a gain of the current frame. The over-driving circuit also includes a second 4-color data generation module configured to generate input 4-color data based on input 3-color data and the gain of the current frame. The over-driving circuit further includes a data modulator configured to generate modulated data based on the output 4-color data of the previous frame, the output 4-color data of the current frame, and the input 4-color data.

Over-driving circuit and display device having an over-driving circuit

An error diffusion method includes: simultaneously receiving first to nth (n is a positive integer of 2 or larger) pixel data at every clock; adding a quantization error stored in a memory to each of the first to (n&#x2212;1)th pixel data and quantizing them into data having a smaller number of bits than the number of input bits; adding the quantization error stored in the memory to the nth pixel data and quantizing it into data having a smaller number of bits than the number of input bits; diffusing the quantization errors of the first to (n&#x2212;1)th pixel data to nearby pixels excluding the first to nth pixels by using a first error diffusion mask, and storing the diffusion results of the quantization errors of the first to (n&#x2212;1)th pixel data in the memory; and diffusing the quantization error of the nth pixel data to pixels around the nth pixel by using a second error diffusion mask, and storing the diffusion results of the quantization error of the nth pixel data in the memory.

Error diffusion method and liquid crystal display using the same

A liquid crystal display includes a display panel, a backlight unit providing light to the display panel, a representative value adjusting unit that divides an input image in conformity with a plurality of blocks divided from the display panel and a light emitting surface of the backlight unit, selectively adjusts a representative value of each block based on a luminance difference between the blocks and a grayscale banding degree of each block, and generates a modified representative value of each block, a dimming value determining unit that maps the modified representative value of each block to a predetermined dimming curve and selects a dimming value of each block, and a light source driver for driving light sources of the backlight unit based on the dimming value of each block.

Liquid crystal display and method of local dimming thereof

Disclosed are a liquid crystal display and a method of the liquid crystal display. The liquid crystal display includes a liquid crystal panel, a backlight unit that supplies light to the liquid crystal panel and has a plurality of light sources, and an image calibration unit that calculates a global dimming resultant value and a local dimming resultant value for an image data signal inputted to the liquid crystal panel, analyzes an average picture level for each block with respect to the image data signal, and determines a convex combination parameter based on the global dimming resultant value, the local dimming resultant value, and the average picture level to generate a calibration dimming value for the backlight unit and an image calibration value for the image data signal.

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Seoul, South Korea

Kyungjoon Kwon