LIQUID CRYSTAL DISPLAY APPARATUS AND LUMINANCE CONTROL METHOD THEREOF
First Claim
1. A liquid crystal display apparatus that irradiates a liquid crystal panel with light beams from a plurality of backlights so as to form and display an image corresponding to a video signal, said liquid crystal display apparatus comprising:
- an extraction unit for extracting the pixel frequency distribution of an input video signal on a luminance level basis, and for extracting the pixel frequency distribution of specific color from a color-difference signal of the input video signal in a screen area, the color-difference signal being determined from the luminance distribution of the plurality of backlights;
a control unit for determining the control amount of the luminance of the plurality of backlights, and the correction amount of the luminance of the liquid crystal panel, on the basis of the result of the extraction, and for outputting a control signal corresponding to the control amount of the luminance and a control signal corresponding to the correction amount of the luminance;
a plurality of backlight driving circuits, each of which drives each of the plurality of backlights on the basis of the control amount of the luminance; and
an image quality adjusting unit for controlling the luminance of the input video signal on the basis of the correction amount of the luminance;
wherein, on a screen area basis, the luminance of the input video signal and the luminance of the backlights are controlled in response to the pixel frequency distribution of specific color extracted from the input video signal.
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Accused Products
Abstract
For the purpose of suppressing untrue black with the change in luminance of video, which is displayed as the same object, being reduced to improve the contrast, there is provided a liquid crystal display apparatus that is capable of: extracting the pixel frequency distribution of an input video signal on a luminance level basis, and extracting the pixel frequency distribution of specific color from a color-difference signal of input video in a screen area, the color-difference signal being determined from the luminance distribution of a plurality of backlights; on the basis of the result of the extraction, determining the control amount of the luminance of the plurality of backlights, and the correction amount of the luminance of a liquid crystal panel, on a screen area basis; controlling the luminance of the plurality of backlights on the basis of the control amount of the luminance; and at the same time, controlling the luminance of the input video signal on the basis of the correction amount of the luminance.
35 Citations
13 Claims
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1. A liquid crystal display apparatus that irradiates a liquid crystal panel with light beams from a plurality of backlights so as to form and display an image corresponding to a video signal, said liquid crystal display apparatus comprising:
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an extraction unit for extracting the pixel frequency distribution of an input video signal on a luminance level basis, and for extracting the pixel frequency distribution of specific color from a color-difference signal of the input video signal in a screen area, the color-difference signal being determined from the luminance distribution of the plurality of backlights; a control unit for determining the control amount of the luminance of the plurality of backlights, and the correction amount of the luminance of the liquid crystal panel, on the basis of the result of the extraction, and for outputting a control signal corresponding to the control amount of the luminance and a control signal corresponding to the correction amount of the luminance; a plurality of backlight driving circuits, each of which drives each of the plurality of backlights on the basis of the control amount of the luminance; and an image quality adjusting unit for controlling the luminance of the input video signal on the basis of the correction amount of the luminance; wherein, on a screen area basis, the luminance of the input video signal and the luminance of the backlights are controlled in response to the pixel frequency distribution of specific color extracted from the input video signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A luminance control method of a liquid crystal display apparatus that irradiates a liquid crystal panel with light beams from a plurality of backlights so as to form and display an image corresponding to a video signal, said luminance control method comprising the steps of:
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extracting the pixel frequency distribution of an input video signal on a luminance level basis, and extracting the pixel frequency distribution of specific color from a color-difference signal of the input video signal included in a screen area, the color-difference signal being determined from the luminance distribution of the plurality of backlights; calculating the correction amount of the luminance of the liquid crystal panel, and the control amount of the luminance of the plurality of backlights, on the basis of the result of the extraction; and driving the plurality of backlights on the basis of the calculated control amount of the luminance, and controlling the luminance of the input video signal on the basis of the correction amount of the luminance; wherein, on a screen area basis, the luminance of the input video signal and the luminance of the backlights are controlled according to the pixel frequency distribution of specific color extracted from the input video signal.
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Specification