Liquid crystal display device and driving method thereof

1. A liquid crystal display device comprising:

a liquid crystal display panel configured to include at least one common electrode bar and a plurality of divisional areas perpendicular to the at least one common electrode bar, the plurality of divisional areas including a first divisional area and a second divisional area;

a common voltage compensator configured to generate a first compensated common voltage corresponding to the first divisional area, and a second compensated common voltage corresponding to the second divisional area, and apply the first compensated common voltage to the at least one common electrode bar of the liquid crystal display panel when the first divisional area is driven during a first portion of a single frame, and apply the second compensated common voltage to the at least one common electrode bar of the liquid crystal display panel when the second divisional area is driven during a second portion of the single frame, the common voltage compensator comprising:

an inverting amplifier having first inverse amplification ratio and second inverse amplification ratio and generating the first compensated common voltage and second compensated common voltage by inversely amplifying a common voltage feedback signal with the first inverse amplification ratio and second inverse amplification ratio, the common voltage feedback signal being fed back through the at least one common electrode bar of the liquid crystal display panel; and

a demultiplexer configured to allow the common voltage feedback signal to be inversely amplified with one of the first inverse amplification ratio and second inverse amplification ratio, the demultiplexer comprising:

a first input terminal configured to receive the common voltage feedback signal,

a second input terminal configured to receive a common voltage control signal, and

a plurality of output terminals connected to a plurality of resistors of the inverting amplifier, respectively,

wherein the common voltage feedback signal is output to one of the plurality of output terminals of the demultiplexer according to the common voltage control signal;

a common voltage controller for generating the common voltage control signal for controlling the common voltage compensator, the common voltage controller comprising:

a line counter configured to count pulses of a data enable signal based on the gate start signal to generate a line count signal; and

a common voltage control signal generator configured to derive the common voltage control signal in each portion of the single frame from the number of pulses of the data enable signal;

wherein a number of portions of the single frame are obtained by dividing the number of pulses of the data enable signal into the number of divisional areas;

wherein the at least one common electrode bar has a first end electrically connected to an output terminal of the common voltage compensator and a second end electrically connected to an input terminal of the common voltage compensator; and

wherein the second compensated common voltage applied during the second portion of the single frame to the second divisional area close to the second end of the at least one common electrode bar is greater than the first compensated common voltage applied during the first portion of the single frame to the first divisional area close to the first end of the at least one common electrode bar.

2. The liquid crystal display device of claim 1 , further comprising:

a timing controller configured to generate control signals which are used to drive the liquid crystal display panel.

3. The liquid crystal display device of claim 2 , wherein the control signals include a gate start signal used to indicate the start of a frame.

4. The liquid crystal display device of claim 1 , further comprising:

a divisional area setting unit configured to provide a parameter indicative of the number of divisional areas which are defined on the liquid crystal display panel.

5. The liquid crystal display device of claim 1 , wherein the inverting amplifier comprises:

a differential amplifier configured to inversely amplify the common voltage feedback signal;

the plurality of resistors connected to an inverting terminal (−) of the differential amplifier; and

a negative feedback resistor connected between an output terminal of the differential amplifier and the inverting terminal of the differential amplifier.

6. The liquid crystal display device of claim 5 , wherein each inverse amplification ratio is set to be a ratio of a resistance of the negative feedback resistor and a resistance of each corresponding one of the plurality of resistors.

7. The liquid crystal display device of claim 5 , wherein the plurality of resistors each has a resistance value which is set by considering an amplitude of a ripple included in the common voltage feedback signal which is generated in the plurality of divisional areas of the liquid crystal display panel.

8. The liquid crystal display device of claim 1 , wherein the respective divisional areas are driven according to a corresponding portion of the single frame.

9. The liquid crystal display device of claim 1 , wherein when a specific divisional area is driven, the corresponding compensated common voltage is applied to the specific divisional area.

10. The liquid crystal display device of claim 1 , wherein the second compensated common voltage is always greater than the first compensated common voltage.