| US 7,595,784 B2 | ||
| Liquid crystal display apparatus with control of LCD and backlight corresponding to an image | ||
| Tsunenori Yamamoto, Hitachi (Japan); Daisuke Kajita, Hitachi (Japan); Ikuo Hiyama, Hitachinaka (Japan); Akitoyo Konno, Hitachi (Japan); Tatsuki Inuzuka, Mito (Japan); and Masatoshi Wakagi, Hitachi (Japan) | ||
| Assigned to Hitachi Displays, Ltd., Chiba (Japan) | ||
| Filed on Feb. 09, 2005, as Appl. No. 11/53,256. | ||
| Claims priority of application No. 2004-031822 (JP), filed on Feb. 09, 2004; and application No. 2004-366989 (JP), filed on Dec. 20, 2004. | ||
| Prior Publication US 2005/0231457 A1, Oct. 20, 2005 | ||
| Int. Cl. G09G 3/36 (2006.01) | ||
| U.S. Cl. 345—102 [345/104] | 11 Claims |
| 1. A liquid crystal display apparatus comprising:
a liquid crystal display composed of a pair of substrates, a liquid crystal layer laid between said pair of substrates, a
plurality of electrode groups for applying an electric field onto said liquid crystal layer, and a plurality of active elements
being connected with said electrode groups and having a plurality of sub-pixel structures;
a backlight unit arranged for controllable light emission of a plurality of colors, for applying a ray of light of each color
onto said liquid crystal display;
a controller for controlling a change of display data of each color on said liquid crystal display and a quantity of each
color ray of light emitted from said backlight unit, based on an output signal sent from a backlight sensor for sensing light
emission of said backlight unit and a video signal of each color being inputted for displaying the corresponding image on
said liquid crystal display; and
a subtitle detecting circuit for detecting a subtitle displayed on the liquid crystal display;
wherein said controller determines a conversion maximum gray scale point MAX in accordance with a result of an analysis of
a video signal of each color to be inputted for displaying onto said liquid crystal display, changes said display data so
as to convert said inputted video signal at the MAX into a signal at a gray scale in which a liquid crystal transmittance
becomes maximum, and lowers a backlight luminance output into a luminance level indicated by the MAX in said input and output
characteristic;
wherein no conversion of a 0 gray scale signal of each color in said inputted video signal is executed with respect to the
color with the highest MAX and the conversion of said 0 gray scale signal of the remaining colors is executed so as to make
the 0 gray scale of each color equal to a 0 gray scale luminance level at which the MAX becomes the highest; and
wherein if the subtitle is detected, said conversion maximum gray scale point MAX is determined on an analyzed result of a
video signal excepting a signal portion corresponding with said detected subtitle.
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