Data driver, liquid crystal display and driving method thereof

1. A liquid crystal display device, comprising:

a comparator which processes a data value; and

a pre-charge controller which pre-charges a data line of a liquid crystal display panel with a pre-charge voltage if the data value is a first value, and pre-charges the data line with a charge share voltage, which has a lower absolute voltage value than the pre-charge voltage if the data value is a second value and the second data value is lower than the first data value,

wherein the pre-charge controller includes:

a source output enable signal and a polarity control signal for controlling a polarity of the data value, which are inputted thereto;

a de-multiplexer which outputs the source output enable signal to any one of a plurality of output terminals in accordance with an output of the comparator and an output of the polarity control signal;

a first transistor for supplying the charge share voltage to the data line in accordance with the output of the de-multiplexer if the data value is the second value;

a second transistor for supplying a positive pre-charge voltage to the data line in accordance with the output of the de-multiplexer if the data value is the first value; and

a third transistor for supplying a negative pre-charge voltage to the data line in accordance with the output of the de-multiplexer if the data value is the first value.

2. The liquid crystal display device according to claim 1 , wherein the

comparator and the pre-charge controller are portions of an integrated circuit for driving the data line.

3. The liquid crystal display device according to claim 1 , wherein the comparator includes:

a signal wire line for supplying any one of bits of the data to the de-multiplexer.

4. The liquid crystal display device according to claim 1 , wherein the comparator includes:

at least one or more gate devices for performing a logical sum operation on the upper bits of the data.

5. The liquid crystal display device according to claim 4 , wherein the comparator includes:

an OR gate for performing a logical sum operation on a first upper bit of a weight value 2 5 and a second upper bit of a weight value 2 6 of the data; and

an AND gate for performing a logical multiply operation on an output of the OR gate and a third upper bit of a weight value 2 7 of the data.

6. The liquid crystal display device according to claim 4 , wherein the comparator includes:

an AND gate for performing a logical multiply operation on a first upper bit of a weight value 2 6 and a second upper bit of a weight value 2 7 of the data.

7. The liquid crystal display device according to claim 1 ,

wherein the comparator includes:

a first AND gate for performing a logical multiply operation on a first upper bit of a weight value “2 5 ” and a second upper bit of a weight value “2 6 ” of the data; and

a second AND gate for performing a logical multiply operation on an output of the first AND gate and a third upper bit of a weight value “2 7 ” of the data.

8. The liquid crystal display device according to claim 1 , wherein the first value is any one of a high data value of 127 or more gray levels, a high data value of 160 or more gray levels, a high data value of 191 or more gray levels and a high data value of 224 or more gray levels, and the corresponding second value is any one of a low data value of less than 127 gray levels, a low data value of less than 160 gray levels, a data value of less than 191 gray levels and a data value of less than 224 gray levels, respectively.

9. The liquid crystal display device according to claim 1 , wherein the charge

share voltage includes:

at least two or more charge share voltages, and the charge share voltages differ from each other within a voltage range that is lower in absolute value than the pre-charge voltage.

10. A driving method of a liquid crystal display device, the method comprising of:

judging a voltage of data;

pre-charging a data line of a liquid crystal display panel with a pre-charge voltage if the voltage of the data is a first voltage; and

pre-charging the data line with a charge share voltage which is lower in absolute value than the pre-charge voltage if the voltage of the data is a second voltage which is lower than the first voltage,

wherein the pre-charge controller includes:

a source output enable signal and a polarity control signal for controlling a polarity of the data value, which are inputted thereto;

a de-multiplexer which outputs the source output enable signal to any one of a plurality of output terminals in accordance with an output of the comparator and an output of the polarity control signal;

a first transistor for supplying the charge share voltage to the data line in accordance with the output of the de-multiplexer if the data value is the second value

a second transistor for supplying a positive pre-charge voltage to the data line in accordance with the output of the de-multiplexer if the data value is the first value; and

a third transistor for supplying a negative pre-charge voltage to the data line in accordance with the output of the de-multiplexer if the data value is the first value.

11. The driving method according to claim 10 , wherein the first voltage is any one of a high data voltage of 127 or more gray levels, a high data voltage of 160 or more gray levels, a high data voltage of 191 or more gray levels and a high data voltage of 224 or more gray levels, and the corresponding second voltage is any one of a low data voltage of less than 127 gray levels, a low data voltage of less than 160 gray levels, a data voltage of less than 191 gray levels and a data voltage of less than 224 gray levels, respectively.

12. The driving method according to claim 10 , wherein the charge share

voltage includes:

at least two or more charge share voltages, and the charge share voltages differ from each other within a voltage range that is lower in absolute value than the pre-charge voltage.