LIQUID CRYSTAL DISPLAY DEVICE AND IMAGE DISPLAY METHOD THEREOF
First Claim
1. A liquid crystal display device, comprising:
- a liquid crystal panel configured to display an image from image signals;
a backlight device disposed on the back side of the liquid crystal panel, and divided into a plurality of regions, the backlight device comprising light sources in each of the regions, wherein the light sources are positioned to emit light onto the liquid crystal panel;
a histogram detector configured to detect an image signal gradation distribution for each region and to produce a histogram therefrom;
an image gain calculator configured to calculate a gain from the detected gradation distribution of the histogram detector, and to control light emission from each light source in each region of the backlight device, anda light emission luminance calculator configured to control the light emission luminance of each light source based on a maximum luminance of the light sources and based on an inverse number of the gain calculated in the image gain calculator.
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Accused Products
Abstract
A liquid crystal panel displays an image from image signals. A backlight device is disposed on the back side of the liquid crystal panel, and is divided into a plurality of regions. The backlight device comprises light sources in each of the regions. The light sources are positioned to emit light onto the liquid crystal panel. A histogram detector detects an image signal gradation distribution for each region and to produce a histogram therefrom. An image gain calculator calculates a gain from the detected gradation distribution of the histogram detector, and controls light emission from each light source in each region of the backlight device. A light emission luminance calculator controls the light emission luminance of each light source based on a maximum luminance of the light sources and based on an inverse number of the gain calculated in the image gain calculator.
72 Citations
12 Claims
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1. A liquid crystal display device, comprising:
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a liquid crystal panel configured to display an image from image signals; a backlight device disposed on the back side of the liquid crystal panel, and divided into a plurality of regions, the backlight device comprising light sources in each of the regions, wherein the light sources are positioned to emit light onto the liquid crystal panel; a histogram detector configured to detect an image signal gradation distribution for each region and to produce a histogram therefrom; an image gain calculator configured to calculate a gain from the detected gradation distribution of the histogram detector, and to control light emission from each light source in each region of the backlight device, and a light emission luminance calculator configured to control the light emission luminance of each light source based on a maximum luminance of the light sources and based on an inverse number of the gain calculated in the image gain calculator. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An image display method comprising:
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obtaining, as image signals for display on a liquid crystal panel, an image signal per each region of a first set on the liquid crystal panel; detecting a histogram of the gradation distribution of image signals per each region of the first set; calculating a gain based on the detected histogram, in order to control light emission luminance of a backlight device, the backlight device being divided into second set of regions corresponding to the first set of regions of the liquid crystal panel; displaying an image according to the image signal per region of the liquid crystal panel while causing each light source in respective regions of the backlight device to emit light emission luminance based on a maximum luminance of the light sources and an inverse of the gain. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification