(a) Field of the Invention
The present invention relates to a liquid crystal display and a driving method thereof.
(b) Description of the Related Art
Recently, in the field of a display device such as a personal computer and a television, it is required that the display device should involve a light weight, a thin thickness and a large screen size. In order to fulfill such requirements, a flat panel display such as a liquid crystal display (LCD) has been developed instead of the cathode ray tube, and applied for practical use in the field of computers, and televisions.
The LCD has a panel with a matrix-typed pixel pattern, and a counter panel facing the former panel. A liquid crystal material bearing a dielectric anisotropy is injected between the two panels. The light transmission through the panels is controlled through varying the strength of the electric fields applied to both ends of the two panels, thereby displaying the desired images.
The display device usually represents original images on the screen by way of the RGB color space intrinsic thereto. That is, when the color space is expressed by way of a plurality of gray levels, gamma correction is made by way of a luminance curve corresponding to each gray level, that is, by way of a gamma curve. A color correction is additionally made, thereby recovering the original images. However, as the RGB color space is mostly device-dependent, the designer of the display device as well as the user thereof should consider the image profile intrinsic to the device when the original images are represented. This is a considerable burden to them. As the kind and the characteristic of the display device are diversified in various manners, it is needed to make a definition of a standard color space for the display device. In this connection, a sRGB color space being the unit standard RGB color space as the average concept of the RGB monitors was proposed on November, 1996 by the HP Company and the MS Company. Since then, the sRGB color space has been accepted as a standard color space on Internet.
A need is made to realize such a sRGB color space with the LCD.
Three requirements should be fulfilled to realize the sRGB color space with the LCD. First, the display luminance level with respect to the maximum input gray level should be established to be 80 cd/m2. Second, the gamma curve expressing the luminance characteristic of the input gray level should agree to the gamma 2.2 curve. Third, the display model offset with respect to the RGB colors should be established to be zero.
It is required for the LCD to realize such a sRGB color space.