The characteristics of LCD display module
LCD are organic complexes made up of long rod-like molecules. In nature, the long axes of these rod-like molecules are roughly parallel.
The first feature of LCDS is that liquid crystal must be poured between two planes lined with slots to work properly. The slots in the two planes are perpendicular to each other, meaning that if the molecules in one plane line up north and south, the molecules in the other plane line up east and west, and the molecules in between are forced into a 90-degree twist. Because the light travels in the direction of the molecules, it is twisted by 90 degrees as it passes through the liquid crystal. But when a voltage is applied to the liquid crystal, the molecules rearrange vertically, allowing light to shine straight out without twisting.
The second feature of LCDS is their reliance on polarizing filters, which are actually a series of thinner and thinner parallel lines, and on the light itself, which is randomly scattered in all directions. These lines form a net, blocking all light that is not parallel to the lines. The polarizing filter's lines are exactly perpendicular to the first one, so they completely block the light that is already polarized. Light penetrates only if the lines of the two filters are perfectly parallel, or if the light itself has been twisted to match the second polarizing filter.
An LCD screen is made up of two polarised filters that are perpendicular to each other and should normally block any light that tries to pass through. However, since the two filters are filled with distorted liquid crystals, after the light passes through the first filter, it is twisted 90 degrees by the liquid crystal molecules and finally passes through the second filter. Apply a voltage to the liquid crystal, on the other hand, and the molecules rearrange themselves so that they are perfectly parallel, so that the light is no longer twisted, so that it is blocked by a second filter. In short, the power will block the light, without power will make the light out.
Of course, it is possible to change the arrangement of liquid crystals in the LCD so that the light is emitted when it is powered up and blocked when it is not.