1. Field of the Invention
The present invention relates to both a driving method and a driving apparatus for a display apparatus, and more particularly, to both a driving method and a driving apparatus capable of reducing a response time of a display apparatus.
2. Description of the Prior Art
An image displaying principle of a liquid crystal display (LCD) lies in externally inputting driving voltages for rearranging liquid crystal molecules of each pixel so that both a polarization state and a transmittance of lights are changed to lead in various luminances. However, liquid crystal molecules are inert to changes of external driving voltages, therefore, in comparison to a conventional cathode ray tube display, a liquid crystal display may incur image blurs while displaying animation.
For neutralizing the defect, voltage overriding may be used. For example, luminance having a gray scale G1 is originally expected to be retrieved by inputting an external driving voltage V1 for having crystal molecules to rotate with an angle θ1, however, for raising a response velocity of crystal molecules, an overdriving voltage V2 higher than the driving voltage V1 is provided as a transition driving voltage, then a stable driving voltage V1 is provided for displaying the gray scale G1. Besides, provided overdriving voltages should be changed corresponding to changes of initial states of the liquid crystal molecules. For example, an overdriving voltage V3 for having a pixel be changed from the gray scale G2 to the gray scale G1 should be different from an overdriving voltage V4 for having the same pixel changed from a gray scale G3 to the gray scale G1. Therefore, an overdriving voltage signal table may be built in the display apparatus for providing different and appropriate overdriving voltages with respect to various changes of gray scales.
Please refer to FIG. 1, which illustrates an overdriving voltage signal table. Fields in the overdriving voltage signal table having a value of 0 indicate a condition that appropriate overdriving voltages may be used for various changes of gray scales, whereas other fields having a value other than 0 indicate a condition that the provided overdriving voltage should exactly follow the value of the field. However, while referring to the table, voltage overdriving may merely be used for changes between intermediate gray scales. In other words, since the driving voltage for changing an intermediate gray scale to a highest gray scale, which has a value of 255 in the table shown in FIG. 1, has reached its maximum, a corresponding overdriving voltage cannot be provided so that the response time cannot be reduced by changing the overdriving voltage according to the overdriving voltage signal table. As a result, some technique has to be come up for performing voltage overdriving for the highest gray scale so as to reduce the response time, during which an intermediate gray scale is changed to a maximal gray scale.