Thin film transistor liquid crystal display (TFT-LCD) panel basic structure as shown in fig.:

Say simply, it is a light switch device control signal. The liquid crystal between two pieces of transparent conductive indium tin oxide (ITO) between the electrodes, via the add on ITO electrode voltage can be controlled by varying the liquid crystal alignment direction (Figure two), and the arrangement direction of liquid crystal with light penetration about, causing the pixel light dark degree different, this is the gray scale control principle (color is produced by the color filter). The pixel gray scale is composed of a data driver (Data driver) determine number of voltage can provide.