The operation of LCD screens is based on a combination of liquid crystal materials and electrical control. Liquid crystals are substances that have properties between those of a liquid and a solid. They can be aligned in a specific way under the influence of an electric field.
In an LCD screen, there are two main components: the liquid crystal layer and the backlight. The backlight, usually a cold - cathode fluorescent lamp (CCFL) or more commonly now, light - emitting diodes (LEDs), provides the illumination source. The liquid crystal layer is placed in front of the backlight. When no voltage is applied to the liquid crystals, they are in a natural state and allow light from the backlight to pass through relatively unobstructed. As a result, the pixel appears bright.
When an electric field is applied to the liquid crystals, their molecular orientation changes. This change in orientation causes the liquid crystals to block or partially block the light from the backlight. By controlling the amount of voltage applied to each individual pixel's liquid crystal, the amount of light passing through can be precisely regulated. For example, in a full - color LCD screen, each pixel is composed of three sub - pixels (red, green, and blue). By adjusting the voltage applied to the liquid crystals in each sub - pixel, different colors and brightness levels can be achieved, allowing for the display of a wide range of images and videos.
