What's the LCD polarizer sheet?

The introduction of LCD polarizer film

The light we usually see is a mixture of vibration waves in all directions, and there is no consistency. A device capable of filtering out light that vibrates in a certain direction is called a polarizer. The polarizer has a limiting effect on the direction of vibration of the light.

If polarizers are attached to the display and below, and the direction of vibration of the light is limited (right angles to each other), the light incident will not pass. Conversely, if the direction of the restrictions is the same, the light will pass. When the light does not pass, it will appear black, and when the light passes, it will appear white.