Characteristics Of LCD Screen

The first characteristic of LCD is that the liquid crystal must be filled between two planes with fine grooves in the columns in order to function properly. The grooves on these two planes are perpendicular to each other (intersecting at 90 degrees), which means that if molecules on one plane are arranged in a north-south direction, molecules on the other plane are arranged in an east-west direction, and molecules located between the two planes are forced into a 90 degree twisted state. Due to the propagation of light along the direction of molecular arrangement, the light is also twisted 90 degrees when passing through the liquid crystal. But when a voltage is applied to the liquid crystal, the molecules will rearrange vertically, allowing light to shine directly without any twisting.
The second characteristic of LCD is that it relies on polarizing filters and the light itself. Natural light randomly diverges in all directions, and polarizing filters are actually a series of increasingly thin parallel lines. These lines form a network that blocks all light rays that are not parallel to them. The lines of the polarizing filter are exactly perpendicular to the first one, so they can completely block those polarized light rays. Only when the lines of the two filters are completely parallel, or when the light itself has been twisted to match the second polarizing filter, can the light penetrate. On the one hand, LCD is composed of two polarizing filters that are perpendicular to each other, so under normal circumstances, all light attempting to penetrate should be blocked. However, due to the presence of twisted liquid crystals between the two filters, the light passing through the first filter will be twisted 90 degrees by the liquid crystal molecules before finally passing through the second filter. On the other hand, if a voltage is applied to the liquid crystal, the molecules will rearrange and become completely parallel, causing the light to no longer twist and thus be blocked by the second filter. In short, adding electricity blocks light, while not adding electricity allows light to be emitted. Of course, it is also possible to change the liquid crystal arrangement in the LCD so that light is emitted when powered on and blocked when not powered on. But since the LCD screen is almost always on, only the solution of "powering on to block the light" can achieve the most energy-efficient goal.