Patent ID: 8378941

Claim:
A liquid crystal display device, comprising: a power consumption reduction portion that analyzes a histogram of first image data of an image and generates second image data and a first luminance control signal, wherein, when the image includes an irrelevance region which is substantially irrelevant to degradation of display quality, the power consumption reduction portion analyzes a histogram of first image data of other region of the image except for an excluded region, and wherein the excluded region includes at least the irrelevance region; a timing controller that is supplied with the second image data and the first luminance control signal and generates gate control signals, data control signals, and a second luminance control signal; a gate driving portion that generates gate voltages using the gate control signals; a data driving portion that generates data voltages using the second image data and the data control signals; a liquid crystal panel that displays the image using the gate voltages and the data voltages; a backlight control portion that generates a backlight control signal using the second luminance control signal; and a backlight unit that supplies light according to the backlight control signal, wherein the power consumption reduction portion includes: a masking portion that detects whether or not the image includes the irrelevant region and outputs a gray level information of first image data of the other region of the image when the image includes the irrelevant region or a gray level information of first image data of the whole region of the image when the image does not include the irrelevant region, a histogram analyzing portion that makes a histogram based upon the gray level information from the masking portion and determines whether or not operating a power consumption reduction mode, a data conversion portion that generates the second image data according to the determination of the histogram analyzing portion, and a luminance adjusting portion that generates the first luminance control signal according to the determination of the histogram analyzing portion, and wherein the power consumption reduction portion further includes a storing portion that stores at least one of a first standard on detecting the irrelevant region and a second standard on defining the excluded region according to type of the image and supplies the at least one of the first and second standards to the masking portion.