In the TN and STN type liquid crystal displays, the simple driving electrodes are all driven by the X, Y-axis cross pattern as shown in the figure below. Therefore, if the display area is larger and larger, Electrode reaction time may be longer. In order to make the screen display the same, the overall speed will slow down. Speaking simpler, it seems like CRT monitors screen update frequency is not fast enough, that is, the user will feel the screen flickers, beating; or when the need for fast 3D animation display, but the display speed can not keep up, The results shown may be delayed. Therefore, the early liquid crystal displays in the size of a certain limit, and not suitable for watching movies, or playing 3D games.
To improve this situation, liquid crystal display technology was driven by active-matrix addressing, which is the ideal device for achieving high data density liquid crystal display with high resolution. The method is to use thin film technology made of silicon transistor electrodes, the use of scanning method to select any one of the display pixel (pixel) on and off. This is actually the use of non-linear function of thin-film transistors to replace the non-linear function of liquid crystal is not easy to control. As shown in the above, in the TFT-type liquid crystal display, conductive glass painted on the network of small lines, the electrode is composed of thin-film transistors arranged by the matrix switch, where the intersection of each line has a get control box, Although the driving signal is rapidly scanned at each display point, only the selected display point in the transistor matrix on the electrode gets a voltage enough to drive the liquid crystal molecules to turn the liquid crystal molecular axis into a "bright" contrast, which is not selected Of the display point is naturally "dark" contrast, and thus to avoid the display function of the liquid crystal field dependence on the ability to rely on.