Exploring the Parts of an LCD
Liquid-crystal displays (LCDs) consistently rank as one of the most popular types of display devices. According to Statista, nearly 200 million LCD TVs will be sold during 2020. TVs, of course, are just one of many applications in which LCDs are used. You can find them in smartphones, tablets, computer monitors, human machine interfaces (HMIs) and other electronics that require a display. While there are different types of LCDs, however, nearly all of them contain a few basic parts.
Backlighting
All LCDs have backlighting. Backlighting consists of bulbs - typically light-emitting diode (LED) or electroluminescent (EL) bulbs - that illuminate the LCD's pixels. The pixels can't illuminate themselves. Rather, they require illumination via backlighting. The backlighting is installed behind the LCD's pixels where it's able to illuminate them.
Liquid Pixels
LCDs contain liquid pixels that change color to create visible images. The liquid pixels used in LCDs have the unique property of propagating light. In other words, light can travel through the liquid pixels. The backlighting produces light that illuminates the LCD's liquid pixels.
You can identify the number of liquid pixels used in an LCD by referencing its resolution. Like with other display devices, the resolution of an LCD refers to its total number of pixels. Resolution is expressed by the number of horizontal pixels and the number of vertical pixels used in an LCD.
Polarizing Layers
Along with backlighting and liquid pixels, LCDs contain polarizing layers. Also known simply as polarizers, they are designed to polarize the light produced by the LCD's backlighting system.
Most LCDs contain two polarizing layers. The two polarizing layers are placed on top of each other. The orientation of these polarizing layers can be adjusted through the application of a voltage, thereby controlling the amount of light that passes through them.
