LCD (Liquid Crystal Display) is a flat panel display widely used in a range of electronic devices such as smartphones, Note PCs/Laptops, monitors, and TVs. Unlike OLED, LCD is not a self-luminous display, so the light from the backlight passing through liquid crystal and color filters to reproduce colors.
As LCD presents information using an external light source, it needs backlights behind the panel. As you can see in the picture above, LCD has a polarizer both top and bottom, and they are aligned vertically so that light can’t leak through them even though the backlight is on.
LCD is a flat panel display that has “liquid crystal” as a key material. A liquid crystal is a substance that shows fluidity like a liquid and a regular arrangement of molecules like a crystal. Liquid crystal, located between both polarizers, is tilted when electricity is applied to the panel, and it can control the direction of light. According to the angle of liquid crystal, the amount of light passing through differs, and it can express a variety of colors by controlling the intensity of light.
In other words, the white light emitted from the backlight passes through liquid crystal and color filters to convey the color to a user. Depending on the technologies used to utilize liquid crystals, LCDs are produced in TN, VA, and PLS panel types.