Normally white LCD screen is referred to as NW LCD screen. Regarding this type of liquid crystal screen, when no voltage is applied, the liquid crystal transmits light and displays a bright picture; when a tonnage of pressure is applied, the liquid crystal does not transmit light and displays a dark picture. A schematic diagram of a normally white liquid crystal display is shown in Figure 1. It is also the most commonly used one.
The schematic diagram of the normally white LCD screen is shown in Figure 1
Normally black LCD screen is referred to as NB LCD screen. For this type of liquid crystal screen, when no voltage is applied, the liquid crystal does not transmit light and displays a dark picture; when a voltage is applied, the liquid crystal transmits light and displays a bright picture. The schematic diagram of the normally black liquid crystal display is shown in Figure 2.
A schematic diagram of a normally black LCD screen is shown in Figure 2
For TN liquid crystal display, the alignment films on the upper and lower glass are perpendicular to each other. The difference between NB and NW liquid crystal is only the absolute position of the polarizer. For NW, the upper and lower polarizers The polarities are perpendicular to each other, so when no voltage is applied, the light will transmit light because the liquid crystal rotates it by 90°; for the NB LCD screen, the polarities of the upper and lower polarizing plates are parallel to each other, so no application of When the voltage is applied, the light will not pass through because the liquid crystal rotates it by 90°.
Why are there two different polarizer configurations, NW and NB? It is important for different application environments. When they are individually used in desktop computers or laptops, most of them are NW configurations. This is because the entire screen of the individual computer software is running. Most of them are bright spots, that is, they are mostly black characters on a white background. Since bright spots are the majority, it is relatively convenient to use NW, and the bright spots of NW do not need to be applied with voltage, and will be more power-saving when used; otherwise NB is suitable for most It is an application with a black background.
