Liquid crystal display device

Patent metadata

Field	Value
Publication number	US-2018286325-A1
Application number	US-201815900376-A
Country	US
Kind code	A1
Filing date	Feb 20, 2018
Priority date	Mar 30, 2017
Publication date	Oct 4, 2018
Grant date	—

Abstract

A liquid crystal display device includes: a first display panel displaying a first image; a second display panel displaying a second image; and an image processor generating first and second image data based on input video signal. The image processor includes a first differential filtering processor, a multiplier that multiplies a grayscale of the image data subjected to the differential filtering by the first differential filtering processor by a correction coefficient, and a first smoothing processor that performs smoothing processing on image data obtained by adding the image data multiplied by the correction coefficient and the image data based on the input video signal. The image processor generates the first image data based on the image data based on the input video signal and the image data subjected to the smoothing processing, and generates the second image data based on the image data subjected to the smoothing processing.

First claim

What is claimed is:

1 . A liquid crystal display device comprising:
a first display panel that displays a first image; a second display panel that displays a second image and is opposed to the first display panel; and an image processor that generates first image data corresponding to the first image and second image data corresponding to the second image based on input video signal, wherein the image processor includes a first differential filtering processor that performs differential filtering of detecting a boundary at which luminance changes in input image data derived from the input video signal, a multiplier that multiplies a grayscale of the image data subjected to the differential filtering by the first differential filtering processor by a correction coefficient settable to a desired value, and a first smoothing processor that performs smoothing processing on image data obtained by adding the image data multiplied by the correction coefficient and the input image data, and the image processor generates the first image data based on the input image data and the image data subjected to the smoothing processing, and generates the second image data based on the image data subjected to the smoothing processing.

2 . The liquid crystal display device according to claim 1 , wherein the first smoothing processor performs the smoothing processing on the input image data using a mean filter having a filter coefficient that becomes a normal distribution.

3 . The liquid crystal display device according to claim 1 , wherein the image processor further includes a correction coefficient calculator that calculates the correction coefficient such that peak luminance of the input image data is equal to peak luminance of the second image data.

4 . The liquid crystal display device according to claim 1 , wherein
a grayscale distribution of the second image data includes a first region in which luminance is substantially equal to peak luminance of the input image data and second regions on right and left sides of the first region, luminance of the second regions being higher than the peak luminance, and a width in which the first region and the second regions are added is substantially equal to a width of the peak luminance in the grayscale distribution of the second image data.

5 . The liquid crystal display device according to claim 3 , wherein the correction coefficient calculator includes an extension filtering processor that performs extension filtering on the input image data with a region including a target pixel and pixels around the target pixel as a filter size, a maximum value of luminance in the filter size being set to luminance of the target pixel in the extension filtering.

6 . The liquid crystal display device according to claim 3 , wherein
the correction coefficient calculator includes
a second differential filtering processor that performs the differential filtering on the input image data,
a second smoothing processor that performs the smoothing processing on the image data subjected to the differential filtering by the second differential filtering processor,
a third smoothing processor that performs the smoothing processing on the input image data,
an adder that adds a grayscale of the image data subjected to the smoothing processing by the third smoothing processor and a grayscale of the image data subjected to the extension filtering, and
a divider that divides the grayscale of the image data added by the adder, by a grayscale of the image data subjected to the smoothing processing by the second smoothing processor, and
the correction coefficient calculator sets a calculation result of the divider to the correction coefficient.

7 . The liquid crystal display device according to claim 3 , further comprising:
a first grayscale decision unit that decides a grayscale of the first image data according to a gamma characteristic of the first display panel based on the input video signal; and a second grayscale decision unit that decides a grayscale of the second image data according to a gamma characteristic of the second display panel based on the input video signal, wherein the first differential filtering processor performs the differential filtering on the image data in which the grayscale is decided by the second grayscale decision unit, the correction coefficient calculator includes
a second differential filtering processor that performs the differential filtering on the image data in which the grayscale is decided by the second grayscale decision unit,
a second smoothing processor that performs the smoothing processing on the image data subjected to the differential filtering by the second differential filtering processor,
a third smoothing processor that performs the smoothing processing on the image data in which the grayscale is decided by the second grayscale decision unit,
an extension filtering processor that performs extension filtering on the image data in which the grayscale is decided by the second grayscale decision unit such that a maximum value of luminance in a filter size is set to luminance of a target pixel with a region including a target pixel and pixels around the target pixel as the filter size,
an adder that adds the grayscale of the image data subjected to the smoothing processing by the third smoothing processor and the grayscale of the image data subjected to the extension filtering, and
a divider that divides the grayscale of the image data added by the adder, by the grayscale of the image data subjected to the smoothing processing by the second smoothing processor,
the correction coefficient calculator sets a calculation result of the divider to the correction coefficient, and the first smoothing processor performs the smoothing processing on image data obtained by adding the image data multiplied by the correction coefficient by the multiplier and the image data in which the grayscale is decided by the second grayscale decision unit.

8 . The liquid crystal display device according to claim 3 , further comprising:
a first grayscale decision unit that decides a grayscale of the first image data according to a gamma characteristic of the first display panel based on the input video signal; and a second grayscale decision unit that decides a grayscale of the second image data according to a gamma characteristic of the second display panel based on the input video signal, wherein the first differential filtering processor performs the differential filtering on the image data in which the grayscale is decided by the second grayscale decision unit, the correction coefficient calculator includes
a second differential filtering processor that performs the differential filtering on the image data in which the grayscale is decided by the second grayscale decision unit,
a second smoothing processor that performs the smoothing processing on the image data subjected to the differential filtering by the second differential filtering processor,
a third smoothing processor that performs the smoothing processing on the image data in which the grayscale is decided by the second grayscale decision unit,
an extension filtering processor that performs extension filtering on the image data based on the input video signal before the grayscale is decided by the second grayscale decision unit such that a maximum value of luminance in a filter size is set to luminance of a target pixel with a region including a target pixel and pixels around the target pixel as the filter size,
an adder that adds the grayscale of the image data subjected to the smoothing processing by the third smoothing processor and the grayscale of the image data subjected to the extension filtering, and
a divider that

Assignees

• Panasonic Liquid Crystal Displ

Inventors

• Koudo Toshikazu
• Nakanishi Hideyuki
• Kikuchi Katsuhiro

Classifications

• G09G2360/04

  Display device controller operating with a plurality of display units · CPC title

• G09G2300/023

  Display panel composed of stacked panels · CPC title

• G09G2320/0276

  for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction · CPC title

• G09G3/36 Primary

  using liquid crystals · CPC title

• G09G3/3688

  suitable for active matrices only · CPC title