Liquid crystal display with common voltage compensation and driving method thereof

1. A liquid crystal display, comprising:

a liquid crystal panel comprising a plurality of pixel units;

a timing controller configured to receive display signals from an external circuit to drive the pixel units;

a data processor comprising a calculation circuit and an analyzing circuit; and

a common voltage circuit;

wherein the calculation circuit is configured to carry out a predetermined calculation between display signals corresponding to the pixel units in a current frame period and display signals corresponding to the pixel units in a previous frame period, the analyzing circuit is configured to provide a compensating signal according to a result of the calculation, and the common voltage circuit is configured to adjust a reference voltage signal according to the compensating signal so as to generate a common voltage signal for the pixel units; and

wherein the calculation circuit further comprises a plurality of subtraction units, each of the subtraction units is configured to carry out a subtracting calculation between a first display signal corresponding to one of the pixel units in the current frame period and a second display signal corresponding to said pixel unit in the previous frame period.

2. The liquid crystal display of claim 1 , further comprising a look up table configured for storing a plurality of compensating control signals, each of the compensating control signals corresponding to a calculation result.

3. The liquid crystal display of claim 2 , wherein the compensating control signal is a code that indicates a compensating time period and a compensating voltage value.

4. The liquid crystal display of claim 3 , wherein the analyzing circuit generates the compensating signal by decoding a selected one of the compensating control signals to obtain a corresponding compensating time period and a corresponding compensating voltage value.

5. The liquid crystal display of claim 4 , wherein the common voltage circuit comprises a voltage adjusting circuit, the voltage adjusting circuit generates an adjusting signal according to the compensating signal, and adjusts the reference voltage signal by superposing the reference voltage signal with the adjusting signal.

6. The liquid crystal display of claim 5 , wherein the adjusting signal is a pulse signal having a voltage amplitude the same as the compensating voltage value, and a pulse width the same as the compensating time period.

7. The liquid crystal display of claim 1 , wherein the calculation circuit further comprises an addition unit, the addition unit is configured to add subtraction results obtained by the subtraction units together.

8. The liquid crystal display of claim 1 , further comprising a memory, the memory is configured to store display signals corresponding to the pixel units in the previous frame period.

9. A method for driving a liquid crystal display, the method comprising:

providing a liquid crystal panel having a plurality of pixel units;

providing a timing controller;

receiving display signals from an external circuit to drive the pixel units via the timing controller;

providing a data processor including a calculation circuit and an analyzing circuit;

carrying out a predetermined calculation between display signals corresponding to the pixel units in a current frame period and display signals corresponding to the pixel units in a previous frame period via the calculation circuit, wherein the predetermined calculation comprises subtracting a first display signal corresponding to one of the pixel units in the previous frame period from a second display signal corresponding said pixel unit in the current frame period, and adding results of the subtractions together to obtain a calculation result;

generating a compensating signal according to a result of the calculation via the analyzing circuit;

providing a common voltage circuit and a reference voltage signal; and

adjusting the reference voltage signal according to the compensating signal via the common voltage circuit, and thereby generating a common voltage signal for the pixel units.

10. The method of claim 9 , further comprising: providing a look up table having a plurality of compensating control signals stored therein; and selecting a corresponding compensating control signal from the look up table according to the result of the calculation.

11. The method of claim 10 , wherein each of the compensating control signals is a code that indicates a compensating time period and a compensating voltage value.

12. The method of claim 11 , wherein an absolute value and a polarity of the compensating voltage value are both determined by the result of the calculation.

13. The method of claim 10 , wherein the compensating signal is generated via decoding the selected one of the compensating control signals by the analyzing circuit.

14. The method of claim 13 , wherein the compensating signal is cooperatively formed by a corresponding compensating time period and a corresponding compensating voltage value.

15. The method of claim 14 , wherein the adjustment of the reference voltage signal comprises: generating an adjusting signal according to the compensating signal, and superposing the reference voltage signal with the adjusting signal.

16. The method of claim 15 , wherein the adjusting signal is a pulse signal having a voltage amplitude the same as the compensating voltage value, and a pulse width the same as the compensating time period.

17. The method of claim 16 , wherein the reference voltage signal is pulled up during the compensating time period when the compensating voltage value is positive, and the reference voltage signal is pulled down during the compensating time period when the compensating voltage value is negative.

18. A liquid crystal display, comprising:

a liquid crystal panel comprising a plurality of pixel units;

a timing controller configured to receive display signals from an external circuit to drive the pixel units;

a data processor comprising a calculation circuit and an analyzing circuit;

a look up table; and

a common voltage circuit, wherein the common voltage circuit comprises a voltage adjusting circuit, the voltage adjusting circuit generates an adjusting signal according to a compensating signal, adjusts a reference voltage signal by superposing the reference voltage signal with the adjusting signal, and the adjusting signal is a pulse signal having a voltage amplitude equal to a compensating voltage value, and a pulse width equal to a compensating time period;

wherein the calculation circuit is configured to carry out a predetermined calculation between display signals corresponding to the pixel units in a current frame period and display signals corresponding to the pixel units in a previous frame period, the analyzing circuit is configured to provide a compensating signal according to a result of the predetermined calculation, and the common voltage circuit is configured to adjust the reference voltage signal according to the compensating signal so as to generate a common voltage signal for the pixel units; and

wherein the look up table is configured for storing a plurality of compensating control signals, each of the compensating control signals corresponding to one calculation result, each of the plurality of the compensating control signals is a code indicating the compensating time period and the compensating voltage value, the analyzing circuit generates the compensating signal by decoding a selected one of the compensating control signals to obtain a corresponding compensating time period and a corresponding compensating voltage value.

19. A method for driving a liquid crystal display, the method comprising:

providing a liquid crystal panel having a plurality of pixel units;

providing a timing controller;

receiving display signals from an external circuit to drive the pixel units via the timing controller;

providing a data processor including a calculation circuit and an analyzing circuit;

carrying out a predetermined calculation between display signals corresponding to the pixel units in a current frame period and display signals corresponding to the pixel units in a previous frame period via the calculation circuit, wherein the predetermined calculation on the display signals comprises subtracting a first display signal corresponding to one of the pixel units in the previous frame period from a second display signal corresponding to the pixel unit in the current frame period;

generating a compensating signal according to a result of the calculation via the analyzing circuit;

providing a common voltage circuit and a reference voltage signal;

adjusting the reference voltage signal according to the compensating signal via the common voltage circuit, and thereby generating a common voltage signal for the pixel units, wherein adjustment of the reference voltage signal comprises generating an adjusting signal according to the compensating signal, and superposing the reference voltage signal with the adjusting signal, and wherein the adjusting signal is a pulse signal having a voltage amplitude equal to a compensating voltage value, and a pulse width equal to a compensating time period;

providing a look up table having a plurality of compensating control signals stored therein, and selecting a corresponding compensating control signal from the look up table according to the result of the calculation; and

generating the compensating signal via decoding the selected one of the compensating control signals by the analyzing circuit, wherein the compensating control signal is cooperatively formed with a corresponding compensating time period and a corresponding compensating voltage value.