How does a monochrome LCD screen work? part one

Monochrome LCDs include TN/HTN/STN/FSTN pen segment type, dot matrix liquid crystal display (LCD), BLACK MASK black film multi-color display, and liquid crystal display module (LCM).

LCD relies on polarizing filters (films) and the light itself. Natural light is diffused randomly in all directions. A polarizing filter is a series of increasingly thin parallel lines. These lines form a net that blocks all light rays that are not parallel to these lines. The line of the polarizing filter is exactly perpendicular to the first one, so it can completely block the polarized light. Only the lines of the two filters are perfectly parallel, or the light itself has been twisted to match the second polarizing filter, for light to pass through.

LCD technology is to pour liquid crystal between two planes lined with fine grooves. The slots in these two planes are perpendicular to each other (intersecting at 90 degrees). That is to say, if the molecules on one plane are aligned north-south, the molecules on the other plane are aligned east-west, and the molecules between the two planes are forced into a 90-degree twisted state. Since light propagates along the direction of the arrangement of molecules, the light is twisted 90 degrees when passing through the liquid crystal. However, when a voltage is applied to the liquid crystal, the molecules will rearrange themselves vertically, allowing the light to shine straight out without any twisting.

However, the arrangement of the liquid crystals in an customized TFT LCD can be changed so that light is emitted when powered and blocked when powered off. However, since the computer screen is almost always on, only the solution of "powering up to block the light" can achieve the most power-saving purpose.