# US 7,609,244 B2 · Apparatus and method of driving liquid crystal display device

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- Number: US 7,609,244 B2
- Document ID: US7609244B2
- Status: Granted
- Kind: B2
- Application number: 11/415,747
- Filed: 2006-05-02
- Published: 2007-01-04
- Granted: 2009-10-27
- Earliest claimed: 2005-06-30
- Assignees: LG Display Co., Ltd.
- Inventors: Seong Gyun Kim; Min Ho Sohn
- Web page: https://patentgrep.com/patent/US7609244B2

## CPC

- G09G 3/3611: {Control of matrices with row and column drivers}
- G09G 3/3406: {Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336)}
- G09G 3/3648: {using an active matrix (G09G3/367 - G09G3/3696 take precedence)}
- G09G 2320/0646: Modulation of illumination source brightness and image signal correlated to each other
- G09G 2320/066: for control of contrast
- G09G 2360/16: Calculation or use of calculated indices related to luminance levels in display data
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)

## Abstract

A driving apparatus and method of an LCD device improves the brightness and the contrast ratio of an image. The driving apparatus includes an LCD panel for displaying an image corresponding to a data signal. A data driver supplies the data signal to the LCD panel. A gate driver supplies a scan signal to the LCD panel. A picture quality improving unit generates a histogram by dividing brightness components of input data into levels, generates data with an extended contrast ratio, and then generates a brightness control signal according to the average value of the histogram. A timing controller supplies reordered data, and controls the data driver and the gate driver. A backlight provides light to the LCD panel. An inverter drives the backlight based on the brightness control signal.

## Claims

### Claim 1

A driving apparatus of an LCD device, having an LCD panel, a data driver, a gate driver, and a backlight that provides a light to the LCD panel, comprising:
a picture quality improving unit configurable to:
generate a histogram by dividing brightness components of input first data into levels;
generate second data having an extended contrast ratio related to a brightness of the histogram by levels using a calculated value of the histogram; and
generate at least one brightness control signal related to the calculated value of the histogram;
a timing controller configurable to supply the second data arranged and control the data driver and the gate driver; and
an inverter configurable to drive the backlight based on the brightness control signal.

### Claim 2 (depends on 1)

The driving apparatus of claim 1, wherein the picture quality improving unit comprises:
a data modulator configurable to generate the second data using the first data;
a backlight controller configurable to generate at least one brightness control signal under control of the data modulation means; and
a control unit configurable to receive a first synchronization signal from an external source, modulating the first synchronization signal in synchronization with the second data, and supplying the modulated first synchronization signal to the timing controller.

### Claim 3 (depends on 2)

The driving apparatus of claim 2, wherein the data modulator comprises:
a brightness/color divider configurable to divide the first data into brightness components and color-difference components;
a histogram analyzer configurable to generate the histogram by dividing the brightness component of the first data by levels and analyzing a histogram number and a slope for each level of the histogram based on a calculated value of the histogram;
a histogram modulator configurable to generate modulated brightness components of extended contrast ratio by using the histogram number and slope for each level of the histogram;
a delay unit configurable to generate delayed color-difference components by delaying the color-difference components the modulated brightness component is generated in the histogram modulator; and
a brightness/color mixer configurable to generate the second data by mixing the modulated brightness component and the delayed color-difference component.

### Claim 4 (depends on 3)

The driving apparatus of claim 3, wherein the histogram analyzer comprises:
a histogram generator configurable to generate the histogram by dividing the brightness component of the first data into levels;
a calculator configurable to generate the calculated value by cumulating the histogram;
a frequency generator configurable to generate a cumulated histogram number of a first region which is smaller than the calculated value, a cumulated histogram number of a second region which is larger than the calculated value, and a histogram number for each level of the histogram, by using the histogram and the calculated value;
a level weight setter configurable to set a weight for each level of the first and second regions, and a brightness weight for each level of the second region, by using a backlight weight supplied from an external source, the cumulated histogram number of the first region, the cumulated histogram number of the second region, the calculated value, and the histogram number; and
a level slope setter configurable to set a slope for each level of the histogram by using a minimum slope value supplied from the external source, the backlight weight, the weight for each level of the first and second regions, and the brightness weight for each level of the second region.

### Claim 5 (depends on 4)

The driving apparatus of claim 4, wherein the level weight setter is configurable to set the weight for each level of the first region by determining a function represented by (calculated value−1)×(histogram number for each level/cumulated histogram number of first region); setting the weight for each level of the second region by determining a function represented by (adjacent histogram level−calculated value)×(histogram number for each level/cumulated histogram number of second region); and setting the brightness weight for each level of the second region by (adjacent histogram level−backlight weight×calculated value)/(adjacent histogram level−calculated value).

### Claim 6 (depends on 4)

The driving apparatus of claim 4, wherein the level slope setter is configurable to set the slope for each level of the first region by determining a function represented by backlight weight×(weight for each level of first region×(1−minimum slope value)+minimum slope value); set the slope of the histogram level having the calculated value by the backlight weight; and set the slope for each level of the second region by determining a function represented by brightness weight for each level of second region×(weight for each level of second region×(1−minimum slope value)+minimum slope value).

### Claim 7 (depends on 3)

The driving apparatus of claim 3, wherein the histogram analyzer comprises:
a histogram generator configurable to generate the histogram by dividing the brightness component of the first data into brightness levels;
a calculator configurable to generate the calculated value by cumulating the histogram;
a frequency generator configurable to generate a cumulated histogram number of a first region which is smaller than the calculated value, a cumulated histogram number of a second region which is larger than the calculated value, and a histogram number for each level of the histogram, by using the histogram and the calculated value;
a level weight setter configurable to set a weight for each level of the first and second regions, and a brightness weight for each level of the second region, by using a backlight weight supplied from the external, the cumulated histogram number of the first region, the cumulated histogram number of the second region, the calculated value, and the histogram number;
a minimum slope setter configurable to set a minimum slope value for a low region if the calculated value of the histogram is lower than an intermediate value of the levels, or a minimum slope value for a high region if the calculated value is higher than the intermediate value by using a minimum slope value input from the external source, the calculated value, a total level number of the histogram, and the intermediate value of levels of the histogram; and
a level slope setter configurable to set a slope for the level of the histogram using the minimum slope values of the low and high regions, the backlight weight, the weight for a level of the first and second regions, and the brightness weight for a level of the second region.

### Claim 8 (depends on 7)

The driving apparatus of claim 7, wherein the level weight setter is configurable to set the weight for the level of the first region by determining a function represented by (calculated value−1)×(histogram number for each level/cumulated histogram number of first region), set the weight for the level of the second region by determining a function represented by (adjacent histogram level−calculated value)×(histogram number for each level/cumulated histogram number of second region), and set the brightness weight for the level of the second region by determining a function represented by (adjacent histogram level−backlight weight×calculated value)/(adjacent histogram level−calculated value).

### Claim 9 (depends on 8)

The driving apparatus of claim 8, wherein the minimum slope setter is configurable to set the minimum slope value of the low region by determining a function represented by 1−(total level number of histogram−intermediate value of levels)/(intermediate value of levels−1)×(1−minimum slope value) if the calculated value is the same as or smaller than the intermediate value of levels, and where the minimum slope setter is configurable to set the minimum slope value of the high region by determining a function represented by 1−(1−minimum slope value)×(intermediate value of levels−1)/(total level number of histogram−intermediate value of levels) if the calculated value is larger than the intermediate value of the levels.

### Claim 10 (depends on 9)

The driving apparatus of claim 9, wherein the level slope setter is configurable to set the slope for each level of the first region by determining a function represented by backlight weight×(weight for each level of first region×(1−minimum slope value of low region)+minimum slope value of low region); set the slope of the histogram level comprising the calculated value by the backlight weight; and set the slope for each level of the second region by determining a function represented by brightness weight for each level of second region×(weight for each level of second region×(1−minimum slope value of high region)+minimum slope value of high region).

### Claim 11 (depends on 3)

The driving apparatus of claim 3, wherein the histogram modulator is configurable to generate the modulated brightness component by determining a function represented by slope for each level of histogram×(present histogram level−previous histogram level)+histogram number of previous level.

### Claim 12 (depends on 2)

The driving apparatus of claim 2, wherein the backlight controller comprises:
a backlight controlling part configurable to generate at least one brightness control signal according to the calculated value of the histogram; and
a digital/analog converter part configurable to convert the brightness control signal provided from the backlight controlling part to an analog signals.

### Claim 13 (depends on 2)

The driving apparatus of claim 2, wherein the backlight comprises at least one lamp that provides a light to at least one region formed by dividing the LCD panel into regions.

### Claim 14 (depends on 13)

The driving apparatus of claim 13, wherein the backlight controller is configurable to generate at least one brightness control signal that generates the light in proportion to a region brightness of the LCD panel, and supply the generated brightness control signal to the inverter.

### Claim 15 (depends on 1)

The driving apparatus of claim 1, wherein the calculated value of the histogram comprises an average value of the histogram.

### Claim 16 (depends on 1)

The driving apparatus of claim 1, wherein the calculated value of the histogram comprises a median value of the histogram.

### Claim 17

A driving apparatus of an LCD device, having an LCD panel, a data driver, a gate driver, and a backlight that provides a light to the LCD panel, comprising:
a picture quality improving unit that is configurable to:
generate a histogram representing brightness components of input first data by levels;
generate second data comprising an extended contrast ratio related to a brightness of the histogram by levels using a backlight weight input from an external source, and the brightness of histogram by levels; and
generate at least one brightness control signal according to a calculated value of the histogram;
a timing controller that supplies the second data, and controls the data driver and the gate driver; and
an inverter that drives the backlight based on the brightness control signal.

### Claim 18 (depends on 17)

The driving apparatus of claim 17, wherein the picture quality improving unit comprises:
a data modulator configurable to generate the second data using the first data;
a backlight controller configurable to generate at least one brightness control signal under control of the data modulation means; and
a control unit configurable to receive a first synchronization signal from an external source, modulating the first synchronization signal in synchronization with the second data, and supplying the modulated first synchronization signal to the timing controller.

### Claim 19 (depends on 18)

The driving apparatus of claim 18, wherein the data modulator comprises:
a brightness/color divider configurable to divide the first data into brightness components and color-difference components;
a histogram analyzer configurable to generate the histogram by dividing the brightness component of the first data by levels and analyzing a histogram number and a slope for each level of the histogram based on a calculated value of the histogram;
a histogram modulator configurable to generate modulated brightness components of extended contrast ratio by using the histogram number and slope for each level of the histogram;
a delay unit configurable to generate delayed color-difference components by delaying the color-difference components the modulated brightness component is generated in the histogram modulator; and
a brightness/color mixer configurable to generate the second data by mixing the modulated brightness component and the delayed color-difference component.

### Claim 20 (depends on 19)

The driving apparatus of claim 19, wherein the histogram analyzer comprises:
a histogram generator configurable to generate the histogram by dividing the brightness component of the first data into levels;
a calculator configurable to generate the calculated value by cumulating the histogram;
a backlight gain controller configurable to generate a backlight gain value using the calculated value, a backlight weight, and a total level number of the histogram;
a frequency generator configurable to generate a cumulated histogram number of a first region which is smaller than the calculated value, a cumulated histogram number of a second region which is larger than the calculated value, and a histogram number for the level of the histogram, by using the histogram and the calculated value;
a level weight setter configurable to set a brightness weight for a level of the second region by using the backlight gain value, the cumulated histogram number of the first region, the cumulated histogram number of the second region, the calculated value, and the histogram number for the level; and
a level slope setter configurable to set a slope for the level of the histogram by using a minimum slope value inputted from the external source, the backlight gain value, the weight for each level of the first and second regions, and the brightness weight for each level of the second region.

### Claim 21 (depends on 20)

The driving apparatus of claim 20, wherein the backlight gain controller is configurable to generate the backlight gain value by determining a function represented by (−((backlight weight−1)/total level number of histogram)×calculated value+backlight weight).

### Claim 22 (depends on 20)

The driving apparatus of claim 20, wherein the level weight setter is configurable to set the weight for a level of the first region by determining a function represented by ((calculated value−1)×(histogram number for each level/cumulated histogram number of first region)); set the weight for a level of the second region by determining a function represented by ((adjacent histogram level−calculated value)×(histogram number for each level/cumulated histogram number of second region)); and set the brightness weight for the level of the second region by determining a function represented by ((adjacent histogram level−backlight weight×calculated value)/(adjacent histogram level−calculated value)).

### Claim 23 (depends on 20)

The driving apparatus of claim 20, wherein the level slope setter is configurable to set a slope for a level of the first region by determining a function represented by (backlight gain value×(weight for each level of first region×(1−minimum slope value)+minimum slope value)); set a slope of the histogram level comprising the calculated value by the backlight gain value, and set the slope for the level of the second region by determining a function represented by (brightness weight for each level of second region×(weight for each level of second region×(1−minimum slope value)+minimum slope value)).

### Claim 24 (depends on 19)

The driving apparatus of claim 19, wherein the histogram analyzer comprises:
a histogram generator configurable to generate the histogram by dividing the brightness component of the first data into levels;
a calculator configurable to generate the calculated value by cumulating the histogram;
a backlight gain controller configurable to generate a backlight gain value using the calculated value, a backlight weight, and a total level number of the histogram;
a frequency generator configurable to generate a cumulated histogram number of a first region which is smaller than the calculated value, a cumulated histogram number of a second region which is larger than the calculated value, and a histogram number for each level of the histogram, by using the histogram and the calculated value;
a level weight setter configurable to set a brightness weight for each level of the second region by using the backlight gain value, the cumulated histogram number of the first region, the cumulated histogram number of the second region, the calculated value, and the histogram number for each level;
a minimum slope setter configurable to set a minimum slope value of a low region if the calculated value of histogram is lower than an intermediate value of the levels, or a minimum slope value of a high region if the calculated value is higher than the intermediate value by using a minimum slope value input from the external source, the calculated value, the level number of the histogram, the intermediate value of the entire level number of the histogram; and
a level slope setter configurable to set a slope for each level of the histogram by using the minimum slope values of the low and high regions, the backlight gain value, the weight for each level of the first and second regions, and the brightness weight for each level of the second region.

### Claim 25 (depends on 24)

The driving apparatus of claim 24, wherein the backlight gain controller is configurable to generate the backlight gain value by determining a function represented by (−((backlight weight−1)/total level number of histogram)×calculated value+backlight weight).

### Claim 26 (depends on 24)

The driving apparatus of claim 24, wherein the level weight setter is configurable to set the weight for a level of the first region by ((calculated value−1)×(histogram number for each level/cumulated histogram number of first region)); set the weight for each level of the second region by determining a function represented by ((adjacent histogram level−calculated value)×(histogram number for each level/cumulated histogram number of second region)); and set the brightness weight for each level of the second region by determining a function represented by ((adjacent histogram level−backlight gain value×calculated value)/(adjacent histogram level−calculated value)).

### Claim 27 (depends on 24)

The driving apparatus of claim 24, wherein the minimum slope setter is configurable to set the minimum slope value of the low region by determining a function represented by (1−(total level number of histogram−intermediate value of the levels)/(intermediate value of the levels−1)×(1−minimum slope value)) if the calculated value is the same as or smaller than the intermediate value of the levels, and the minimum slope seller means is configurable to set the minimum slope value of the high region by (1−(1−minimum slope value)×(intermediate value of the levels−1)/(total level number of histogram−intermediate value of the levels)) if the calculated value is larger than the intermediate value of the levels.

### Claim 28 (depends on 27)

The driving apparatus of claim 27, wherein the level slope setter is configurable to set the slope for each level of the first region by determining a function represented by (backlight gain value×(weight for each level of first region×(1−minimum slope value of low region)+minimum slope value of low region)); set the slope of the histogram level comprising the calculated value by the backlight gain value; and set the slope for each level of the second region by determining a function represented by (brightness weight for each level of second region×(weight for each level of second region×(1−minimum slope value of high region)+minimum slope value of high region)).

### Claim 29 (depends on 19)

The driving apparatus of claim 19, wherein the histogram modulator is configurable to generate the modulated brightness component by determining a function represented by (slope for each level of histogram×(present histogram level−previous histogram level)+histogram number of previous level).

### Claim 30 (depends on 18)

The driving apparatus of claim 18, wherein the backlight controller comprises:
a backlight controlling part configurable to generate at least one brightness control signal according to the calculated value of the histogram; and
a digital/analog converter part configurable to convert the brightness control signal provided from the backlight controlling unit to an analog signals.

### Claim 31 (depends on 18)

The driving apparatus of claim 18, wherein the backlight comprises at least one lamp that provides a light to at least one region formed by dividing the LCD panel into regions.

### Claim 32 (depends on 31)

The driving apparatus of claim 31, wherein the backlight controller is configurable to generate at least one brightness control signal that generates the light in proportion to a region brightness of the LCD panel, and supply the generated brightness control signal to the inverter.

### Claim 33 (depends on 15)

The driving apparatus of claim 15, wherein the calculated value of the histogram comprises an average value of the histogram.

### Claim 34 (depends on 15)

The driving apparatus of claim 15, wherein the calculated value of the histogram comprises a median value of the histogram.

### Claim 35

A driving method of an LCD device having an LCD panel that displays an image corresponding to a data signal, a data driver that supplies the data signal to the LCD panel, and a gate driver that supplies a scan signal to the LCD panel, comprising:
generating a histogram by dividing brightness components of input first data into levels, and generating second data having an extended contrast ratio related to a brightness of the histogram by levels using a calculated value of the histogram;
arranging the second data; and
supplying the arranged second data to the data driver.

### Claim 36 (depends on 35)

The driving method of claim 35, further comprising:
generating at least one brightness control signal based on the calculated value of the histogram; and
providing a light to the LCD panel based on the brightness control signal.

### Claim 37 (depends on 36)

The driving method of claim 36, providing the light to the LCD panel comprises:
generating a lamp driving voltage according to the brightness control signal; and
driving at least one lamp to emit the light to the LCD panel divided into at least one region with the lamp driving voltage.

### Claim 38 (depends on 37)

The driving method of claim 37, generating at least one brightness control signal comprises generating at least one brightness control signal to generate the light in proportion to the region brightness of the LCD panel.

### Claim 39 (depends on 35)

The driving method of claim 35, wherein generating the second data comprises:
dividing the first data into brightness components and color-difference components;
analyzing a histogram number and setting a slope for a level of the histogram with the calculated value of the histogram;
generating modulated brightness components of extended contrast ratio by using the histogram number and slope for the level of the histogram;
generating delayed color-difference components by delaying the color-difference components until generating the modulated brightness component; and
generating the second data by mixing the modulated brightness component and the delayed color-difference component.

### Claim 40 (depends on 39)

The driving method of claim 39, wherein setting the histogram number and slope for the level of the histogram comprises:
generating the histogram by dividing the brightness component of the first data into levels;
generating the calculated value by cumulating the histogram;
generating a cumulated histogram number of a first region which is smaller than the calculated value, a cumulated histogram number of a second region which is larger than the calculated value, and a histogram number for the level of the histogram, by using the histogram and the calculated value;
setting a weight for a level of the first region and the second region, and a brightness weight for the level of the second region, by using a backlight weight supplied from the external source, the cumulated histogram number of the first region, the cumulated histogram number of the second region, the calculated value, and the histogram number; and
setting a slope for the level of the histogram by using a minimum slope value supplied from the external source, the backlight weight, the weight for the level of the first region and the second region, and the brightness weight for the level of the second region.

### Claim 41 (depends on 40)

The driving method of claim 40, wherein setting the weight for each level of the first region and the second region and the brightness weight for each level of the second region comprises:
setting the weight for each level of the first region by determining a function represented by (calculated value−1)×(histogram number for each level/cumulated histogram number of first region);
setting the weight for the level of the second region by determining a function represented by (adjacent histogram level−calculated value)×(histogram number for each level/cumulated histogram number of second region); and
setting the brightness weight for the level of the second region by determining a function represented by (adjacent histogram level−backlight weight×calculated value)/(adjacent histogram level−calculated value).

### Claim 42 (depends on 40)

The driving method of claim 40, setting the slope for each level of the histogram comprises:
setting the slope for the level of the first region by determining a function represented by backlight weight×(weight for each level of first region×(1−minimum slope value)+minimum slope value);
setting the slope of the histogram level comprising the average value by the backlight weight; and
setting the slope for the level of the second region by determining a function represented by brightness weight for each level of second region×(weight for each level of second region×(1−minimum slope value)+minimum slope value).

### Claim 43 (depends on 39)

The driving method of claim 39, setting the histogram number and slope for each level comprises:
generating the histogram by dividing the brightness component of the first data into levels;
generating the calculated value by cumulating the histogram;
generating a cumulated histogram number of a first region which is smaller than the calculated value, a cumulated histogram number of a second region which is larger than the calculated value, and a histogram number for the level of the histogram, by using the histogram and the calculated value;
setting a weight for the level of the first region and the second region, and a brightness weight for the level of the second region, by using a backlight weight supplied from the external source, the cumulated histogram number of the first region, the cumulated histogram number of the second region, the calculated value, and the histogram number;
setting a minimum slope value for a low region if the calculated value of histogram is lower than an intermediate value of the levels, and a minimum slope value for a high region if the calculated value is higher than the intermediate value by using a minimum slope value input from the external source, the calculated value, a total level number of the histogram, and the intermediate value of the levels of the histogram; and
setting a slope for the level of the histogram using the minimum slope values of the low and high regions, the backlight weight, the weight for each level of the first and second regions, and the brightness weight for the level of the second region.

### Claim 44 (depends on 43)

The driving method of claim 43, setting the weight for the level of the first and second regions and the brightness weight for the level of the second region comprise:
setting the weight for the level of the first region by determining a function represented by (calculated value−1)×(histogram number for each level/cumulated histogram number of first region);
setting the weight for the level of the second region by determining a function represented by (adjacent histogram level−calculated value)×(histogram number for each level/cumulated histogram number of second region); and
setting the brightness weight for the level of the second region by determining a function represented by (adjacent histogram level−backlight weight×calculated value)/(adjacent histogram level−calculated value).

### Claim 45 (depends on 43)

The driving method of claim 43, setting the minimum slope values of the low and high regions comprises:
setting the minimum slope value of the low region by determining a function represented by (1−(total level number of histogram−intermediate value of the levels)/(intermediate value of the levels−1)×(1−minimum slope value)) if the calculated value is the same as or smaller than the intermediate value of the levels; and
setting the minimum slope value of the high region by determining a function represented by (1−(1−minimum slope value)×(intermediate value of the levels−1)/(total level number of histogram−intermediate value of the levels)) if the calculated value is larger than the intermediate value of the levels.

### Claim 46 (depends on 45)

The driving method of claim 45, setting the slope for the level of the histogram comprises:
setting the slope for the level of the first region by determining a function represented by (backlight weight×(weight for each level of first region×(1−minimum slope value)+minimum slope value));
setting the slope of the histogram level having the calculated value by the backlight weight; and
setting the slope for the level of the second region by determining a function represented by (brightness weight for each level of second region×(weight for each level of second region×(1−minimum slope value)+minimum slope value)).

### Claim 47 (depends on 39)

The driving method of claim 39, generating the modulated brightness component comprises generating the modulated brightness component by determining a function represented by (slope for each level of histogram×(present histogram level−previous histogram level)+histogram number of previous level).

### Claim 48 (depends on 35)

The driving method of claim 35, wherein the calculated value of the histogram comprises an average value of the histogram.

### Claim 49 (depends on 35)

The driving method of claim 35, wherein the calculated value of the histogram comprises a median value of the histogram.

### Claim 50

A driving method of an LCD device comprising an LCD panel that displays an image corresponding to a data signal, a data driver that supplies the data signal to the LCD panel, and a gate driver that supplies a scan signal to the LCD panel, comprising:
generating a histogram by dividing brightness components of input first data into levels, and generating second data comprising an extended contrast ratio related to a brightness of the histogram by levels using a backlight weight input from the external source;
arranging the second data; and
supplying the arranged second data to the data driver.

### Claim 51 (depends on 50)

The driving method of claim 50, further comprising:
generating at least one brightness control signal based on a calculated value of the histogram; and
providing the light to the LCD panel based on the brightness control signal.

### Claim 52 (depends on 51)

The driving method of claim 51, providing the light to the LCD panel comprises:
generating a lamp driving voltage according to the brightness control signal; and
driving at least one lamp to emit the light to the LCD panel divided into at least one region with the lamp driving voltage.

### Claim 53 (depends on 52)

The driving method of claim 52, generating at least one brightness control signal comprises generating at least one brightness control signal so as to generate the light in proportion to a region brightness of the LCD panel.

### Claim 54 (depends on 50)

The driving method of claim 50, generating the second data comprises:
dividing the first data into brightness components and color-difference components;
analyzing a histogram number and setting a slope for the level of the histogram with the calculated value of the histogram;
generating modulated brightness components of extended contrast ratio by using the histogram number and slope for the level of the histogram;
generating delayed color-difference components by delaying the color-difference components until finished generating the modulated brightness component; and
generating the second data by mixing the modulated brightness component and the delayed color-difference component.

### Claim 55 (depends on 54)

The driving method of claim 54, setting the histogram number and slope for the level comprises:
generating the histogram by dividing the brightness component of the first data into levels;
generating the calculated value by cumulating the histogram;
generating a backlight gain value using the calculated value, the backlight weight, and a total level number of the histogram;
generating a cumulated histogram number of a first region which is smaller than the calculated value, a cumulated histogram number of a second region which is larger than the calculated value, and a histogram number for the level of the histogram, by using the histogram and the calculated value;
setting a brightness weight for the level of the second region by using the backlight gain value, the cumulated histogram number of the first region, the cumulated histogram number of the second region, the calculated value, and the histogram number for the level; and
setting a slope for the level of the histogram by using a minimum slope value input from the external source, the backlight gain value, the weight for the level of the first and second regions, and the brightness weight for the level of the second region.

### Claim 56 (depends on 55)

The driving method of claim 55, wherein generating the backlight gain value comprises determining a function represented by (−((backlight weight−1)/total level number of histogram)×calculated value+backlight weight).

### Claim 57 (depends on 55)

The driving method of claim 55, setting the weight for the level of the first region and the second region and the brightness weight for the level of the second region comprises:
setting the weight for the level of the first region by determining a function represented by ((calculated value−1)×(histogram number for each level/cumulated histogram number of first region));
setting the weight for the level of the second region by ((adjacent histogram level−calculated value)×(histogram number for each level/cumulated histogram number of second region)); and
setting the brightness weight for the level of the second region by ((adjacent histogram level−backlight gain value×calculated value)/(adjacent histogram level−calculated value)).

### Claim 58 (depends on 55)

The driving method of claim 55, wherein setting the slope for each level of the histogram comprises:
setting the slope for the level of the first region by determining a function represented by (backlight gain value×(weight for each level of first region×(1−minimum slope value)+minimum slope value));
setting the slope of the histogram level comprising the calculated value by the backlight gain value; and
setting the slope for the level of the second region by determining a function represented by (brightness weight for each level of second region×(weight for each level of second region×(1−minimum slope value)+minimum slope value).

### Claim 59 (depends on 54)

The driving method of claim 54, wherein setting the histogram number and slope for the level comprises:
generating the histogram by dividing the brightness component of the first data into levels;
generating the calculated value by cumulating the histogram;
generating a backlight gain value using the calculated value, a backlight weight, and a total level number of the histogram;
generating a cumulated histogram number of a first region which is smaller than the calculated value, a cumulated histogram number of a second region which is larger than the calculated value, and a histogram number for the level of the histogram, by using the histogram and the calculated value;
setting a brightness weight for the level of the second region by using the backlight gain value, the cumulated histogram number of the first region, the cumulated histogram number of the second region, the calculated value, and the histogram number for the level;
setting a minimum slope value of a low region if the calculated value of histogram is lower than an intermediate value of the levels, and a minimum slope value of a high region if the calculated value is higher than the intermediate value by using a minimum slope value input from the external source, the calculated value, the entire level number of the histogram, the intermediate value of the entire level number of the histogram; and
setting a slope for the level of the histogram by using the minimum slope values of the low region and the high region, the backlight gain value, the weight for the level of the first region and the second region, and the brightness weight for the level of the second region.

### Claim 60 (depends on 59)

The driving method of claim 59, generating the backlight gain value comprises determining a function represented by (−((backlight weight−1)/total level number of histogram)×calculated value+backlight weight).

### Claim 61 (depends on 59)

The driving method of claim 59, wherein setting the weight for the level of the first region and the second region and the brightness weight for the level of the second region comprises:
setting the weight for the level of the first region by determining a function represented by ((calculated value−1)×histogram number for each level/cumulated histogram number of first region));
setting the weight for the level of the second region by determining a function represented by ((adjacent histogram level−calculated value)×(histogram number for each level/cumulated histogram number of second region)); and
setting the brightness weight for the level of the second region by determining a function represented by ((adjacent histogram level−backlight gain value×calculated value)/(adjacent histogram level−calculated value)).

### Claim 62 (depends on 59)

The driving method of claim 59, wherein setting the minimum slope values of the low region and the high region comprises:
setting the minimum slope value of the low region by determining a function represented by (1−(total level number of histogram−intermediate value of levels)/(intermediate value of levels−1)×(1−minimum slope value)) if the calculated value is the same as or smaller than the intermediate value of the levels; and
setting the minimum slope value of the high region by determining a function represented by (1−(1−minimum slope value)×(intermediate value of levels−1)/(total level number of histogram−intermediate value of levels)) if the calculated value is larger than the intermediate value of the levels.

### Claim 63 (depends on 62)

The driving method of claim 62, setting the slope for the level of the histogram comprises:
setting the slope for the level of the first region by determining a function represented by (backlight gain value×(weight for each level of first region×(1−minimum slope value of low region)+minimum slope value of low region));
setting the slope of the histogram level comprising the calculated value by the backlight gain value; and
setting the slope for the level of the second region by determining a function represented by (brightness weight for each level of second region×(weight for each level of second region×(1−minimum slope value of high region)+minimum slope value of high region)).

### Claim 64 (depends on 54)

The driving method of claim 54, wherein generating the modulated brightness component comprises generating the modulated brightness component by determining a function represented by (slope for each level of histogram×(present histogram level−previous histogram level)+histogram number of previous level).

### Claim 65 (depends on 50)

The driving method of claim 50, wherein the calculated value of the histogram comprises an average value of the histogram.

### Claim 66 (depends on 50)

The driving method of claim 50, wherein the calculated value of the histogram comprises a median value of the histogram.