What does backlight mean Type of light source

Backlight is a type of lighting used in monitors using LCD liquid crystal display technology. Liquid crystal displays cannot emit light on their own and need to rely on a light source to provide a visible image. In addition to being used in computer monitors, LCD TVS, and smartphones, backlighting is also used in small displays such as watches and pocket calculators to improve readability in low-light conditions.

Unlike headlights, which are illuminated from the front, backlights usually create illumination from the side or back of the screen. Most LCD screens are composed of several layers, of which the backlight is the farther layer. Light valves usually help change the amount of light reaching the human eye by blocking light from passing through with the help of polarizing filters.

There are five main light sources:

1. Light-emitting diodes
2. Hot cathode fluorescent lamp
3. Cold cathode fluorescent lamp
4. Incandescent light bulbs
5. Electroluminescent panel

Among them, only the electroluminescent panel is able to provide uniform light over the entire surface. For other light sources, a diffuser is needed to provide uniform light. White backlight is more important than color backlight.

Backlighting helps achieve a thinner, lighter and clearer display. Compared with existing display technologies, including OLED, LCD screens that utilize backlight have a longer service life. However, displays that use backlight consume more power than devices based on OLED technology, for example.