Liquid crystal display with controllable backlight for increased display quality and decreased power consumption

1. A liquid crystal display device, comprising:

a liquid crystal display panel screen divided into a plurality of areas, each of which contains a plurality of pixels;

a plurality of lamp tube backlight sources to selectively irradiate light respectively to the divided areas of the screen; and

a controller to obtain at least one intermediate value of the brightness of the plurality of pixels of at least one of the divided areas and to control a brightness of at least one of the backlight sources which selectively illuminates the at least one divided area according to the at least one intermediate brightness value to prevent a rapid brightness deviation between said at least one of the divided areas and another divided area,

wherein the controller includes:

a brightness/color difference separator to separate brightness and color difference components of the data;

an area determiner to divide the brightness component obtained from the brightness/color difference separator to correspond with the divided areas,

an intermediate value extractor to extract an intermediate value of the brightness component for each of the divided areas;

a brightness modulator to modulate the brightness component of the data by using the extracted intermediate values;

a color difference delayer to delay the color difference components of the data by as much as a process time of the area determiner, the intermediate value extractor and the brightness modulator during a process time for modulating the brightness by areas of the brightness modulator wherein the modulated brightness component is synchronized with the delayed color difference components;

a brightness/color difference mixer to mix the modulated brightness component and the delayed color difference component; and

a control signal delayer to delay timing signals supplied from a system during a time required for the data modulation process by the controller, and

wherein each of the divided areas is 3*3 pixels, and the intermediate value is the fifth brightness value among the brightness values of the 3*3 pixels in order.

2. The liquid crystal display device according to claim 1 , wherein the controller controls the brightness of each of the backlight sources independently from each other.

3. The liquid crystal display device according to claim 1 , wherein the controller generates at least one drive control signal corresponding to the at least one intermediate brightness value.

4. The liquid crystal display device according to claim 3 , further comprising:

a plurality of light source drivers to selectively drive the backlight sources in response to the at least one drive control signal.

5. The liquid crystal display device according to claim 1 , wherein the controller modulates the data based on the at least one intermediate brightness value.

6. The liquid crystal display device according to claim 1 , wherein the intermediate value extractor includes a median filter.

7. A method of controlling a liquid crystal display device, the liquid crystal display device including a liquid crystal display panel screen divided into a plurality of areas, each of which contains a plurality of pixels, and a plurality of lamp tube backlight sources, the method comprising:

obtaining at least one intermediate brightness value associated with input data for the plurality of pixels in at least one of the divided areas; and

controlling a brightness of at least one of the lamp tube backlight sources corresponding to the at least one divided area according to the at least one intermediate brightness value to prevent a rapid difference in brightness between plural divided areas and to affect power consumption of, and heat generated by, the backlight sources,

wherein the controlling step includes:

separating brightness and color difference components of the data;

dividing the brightness component to correspond with the divided areas;

extracting an intermediate value of the brightness component for each of the divided areas;

modulating the brightness component of the data by using the extracted intermediate values;

delaying the color difference components of the data by as much as a process time of the steps of dividing the brightness component, extracting an intermediate value of the brightness component and modulating the brightness component of the data during a process time for modulating the brightness areas of a brightness modulator, wherein the modulated brightness component synchronized with the delayed color components;

mixing the modulated brightness component and the delayed color difference component by using a brightness/color difference mixer; and

delaying timing signals supplied from a system by using a control signal during a time required for the controlling step, and

wherein each of the divided areas is 3*3 pixels and the intermediate value is the fifth brightness value among the brightness values of the 3*3 pixels in order.

8. The method according to claim 7 , wherein in the controlling step, the brightness of each of the backlight sources is controlled independently from each other.

9. The method according to claim 7 , further comprising:

modulating the data based on the at least one intermediate brightness value.

10. The method according to claim 7 , wherein the extracted intermediate values are median values.