Liquid crystal display device for displaying video data

• US 8,125,427 B2
• Filed: 10/03/2008
• Issued: 02/28/2012
• Est. Priority Date: 03/27/2000
• Status: Expired due to Term

• Current Assignee: Japan Display Incorporated
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated), Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Inventors: Nishitani, Shigeyuki, Maeda, Takeshi, Kawabe, Kazuyoshi, Kurihara, Hiroshi, Takagi, Tetsuo, Ohashi, Toshiaki
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): Shapiro, Leonid
• Application Number:
  US12/245,087
• Publication Number:
  US 20090040157A1
• Time in Patent Office: 1,243 Days
• Field of Search: 345/87, 345 88- 89, 345/204
• US Class Current: 345/87
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/2007 Display of intermediate tones
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: H04N 5/66 Transforming electric information into light information scanning details H04N3/00
• CPC Class Codes: H04N 9/69 for modifying the colour signals by gamma correction controlling camera response for colour signals H04N23/83

Abstract

A liquid crystal display device for displaying video data having a detection circuit for detecting a luminance distribution based on video data which is inputted, the luminance distribution being indicative of generation frequency of gradations in each of divided region which includes a plurality of gradations. The display device includes a determination circuit for determining at least one of a plurality of divided regions of higher generation frequency of gradation than that of other divided regions based on the luminance distribution, a correction circuit for correcting the video data so as to make a luminance characteristic of the at least one of the plurality of divided regions of higher generation frequency of gradation more abrupt than a luminance characteristic of the other divided regions, and a liquid crystal display panel for displaying the corrected video data. A width of the divided region is changeable.

Claims

1. A liquid crystal display device for displaying video data, comprising:

a detection circuit for detecting a histogram of gradations for each of divided regions based on video data which is inputted, each divided region including a plurality of gradations;

a determination circuit for determining at least one of a plurality of divided regions of higher generation frequency of gradation on the histogram than that of other divided regions based on the histogram;

a correction circuit for correcting the video data so as to make a luminance characteristic of the at least one of the plurality of divided regions of higher generation frequency of gradation on the histogram more abrupt than a luminance characteristic of the other divided regions; and

a liquid crystal display panel for displaying the corrected video data;

wherein a width of the divided region becomes narrower as a light transmittance of a liquid crystal of the liquid crystal display device becomes greater.

2. A liquid crystal display device for displaying video data, comprising:

a detection circuit for detecting a histogram of gradations for each of divided regions based on video data which is inputted, each divided region including a plurality of gradations;

a determination circuit for determining at least one of a plurality of divided regions of higher generation frequency of gradation on the histogram than that of other divided regions based on the histogram;

a correction circuit for increasing an output gradation number against an input gradation number of the at least one of the plurality of divided regions of higher generation frequency of gradation on the histogram more than an output gradation number against an input gradation number of other divided regions, to correct the video data; and

a liquid crystal display panel for displaying the corrected video data;

wherein a width of the divided region becomes narrower as a light transmittance of the liquid crystal of the liquid crystal display device becomes greater.

3. A liquid crystal display device for displaying video data, comprising:

a detection circuit for detecting a histogram of gradations for each of divided regions based on the video data which is inputted, each divided region including a plurality of gradations;

a determination circuit for determining at least one of a plurality of divided regions of higher generation frequency of gradation on the histogram than that of other divided regions based on the histogram;

a correction circuit for correcting the video data so as to emphasize contrast of the at least one of the plurality of divided regions of higher generation frequency of gradation more than contrast of the other divided regions; and

a liquid crystal display panel for displaying the corrected video data;

wherein a width of the divided region becomes narrower as a light transmittance of the liquid crystal of the liquid crystal display device greater.