Liquid-crystal display (LCD) is currently the world’s leading display technology. You can find computer monitors, TVs, smartphones, infotainment systems and countless other display devices featuring LCD technology. In fact, display devices marketed as “LED” generally use LCD technology.
While LCD is highly effective at creating display devices, though, it still requires the use of a backlight. Upon reading this information, you might be wondering why LCDs need a backlight.
To better understand the importance of a backlight in LCDs, you must first understand the purpose of backlights. The term “backlight” simply refers to the use of an illumination system in a display device. Backlights are installed behind the display layer, allowing it to illuminate the display. Without a backlight — or any other form of illumination — display devices would remain dim and, therefore, offer low-quality images.
Not all display devices require a backlight. Cathode ray tube (CTR) devices, for example, produce their own illumination, so adding a backlight offers no real benefit. In the past, CRT was the most common type of display technology, with most TVs and computer monitors using it. In recent years, however, LCD has surpassed CRT to become the world’s leading display technology.
Why LCDs Use a Backlight
Unlike their CRT counterparts, LCDs aren’t capable of producing illumination themselves. LCDs, of course, are characterized by the use of liquid pixels made of an organic material. The liquid pixels within an LCD device don’t illuminate on their own. Rather, they require illumination from a separate component, known as a backlight.
The bottom line is that a backlight is an essential component in LCDs. Without a backlight, an LCD display device will remain black, rendering it unviewable.
Types of LCD Backlights
All backlights are designed to perform the same basic operation of illuminating a display device, but there are different types of backlights, each of which works in a different way.
In LCD devices, some of the most commonly used backlights include LED, CCFL, EL-WLED, WLED array and RGB-LED. With the exception of CCFL, all these backlight technologies involve light-emitting diodes (LEDs). An electrical current is applied to the LEDs to illuminate the LCD’s display, thus forming the device’s image.
You’ll often see display devices marketed as “LED.” Unbeknost to many people, LED display devices are actually LCD devices with an LED backlight. As a result, many people are surprised to learn their LED display device is actually an LCD device with an LED backlight.