Patent ID: 7768495

Claim:
A luminance control apparatus of a liquid crystal display device comprising: a liquid crystal display panel divided into a plurality of designated areas, each designated area including a plurality of pixels, each pixel including a red sub-pixel, a green sub-pixel and a blue sub-pixel; a plurality of lamp units, each lamp unit providing light to a designated area of the plurality of designated areas of the liquid crystal display panel; an arithmetic unit including: a scan part configured to detect a gray level value of the red sub-pixel, the green sub-pixel and the blue sub-pixel for each pixel within each designated area; and a calculating part configured to extract a peak value of each pixel by selecting a maximum gray-level value from among the detected gray level values, and to calculate an average peak value of each designated area by averaging the extracted peak values of the pixels within the designated area; a lamp driver for each of the plurality of lamp units, each lamp driver configured to control the corresponding lamp unit based on the calculated average peak value corresponding to the designated area of the lamp unit; and a look up table arranged between the arithmetic unit and the lamp driver, the lookup table configured to map the average peak value calculated by the arithmetic unit to a control signal, wherein each of the plurality of lamp units are divisionally driven in each designated area every image frame.