Photo: ReTheCat

LED-backlit LCDs have become one of the most popular types of display devices. As their name suggests, they are essentially liquid-crystal displays (LCDs) that feature a light-emitting diode (LED) backlighting. Even if you’ve seen or used an LED-backlit LCD, though, you might be wondering how they work. While there are different types of LED-backlit LCDs, most of them work in the same basic way.

Overview of LED-Backlit LCDs

Contrary to popular belief, LCDs aren’t capable of producing their own illumination. Rather, they require the use of a separate backlighting solution to illuminate their liquid crystals.

In the past, most LCDs used cathode fluorescence lamp (CCFL) backlighting. TVs and computer monitors produced during the early 2000s, for example, often used CCFL backlighting. In recent years, however, most manufacturers have switched to using LED backlighting for their LCDs. Known as LED-backlit LCDs, they’ve become the preferred choice among manufacturers and consumers alike.

Breaking Down an LED-Backlit LCD

LED-backlit LCDs feature the same basic construction as their CCFL-backlit counterparts. They are made using TFT LCDs, but instead of CCFL backlighting, they use LED backlighting. When activated, the LED bulbs illuminate the liquid pixels, thereby creating colored images.

It’s important to note that there are two primary types of LED-backlit LCDs: edge-lit and direct LED full array. With edge-lit LCDs, the LEDs are embedded around the perimeter of the screen. They feature a light guide that evenly distributes their light across the liquid pixels from behind the screen. In comparison, direct LED full array feature a complete array of LEDs behind the screen. Direct LED full array is a more complex type of backlighting technology, but it offers a higher level of versatility because of its ability to control the light power in different parts of the screen.

Benefits of LED-Backlit LCDs

There are several benefits of LED-backlit LCDs, one of which is a higher color gamut. When compared to other display technologies, LED-backlit LCDs can produce images in a wider range of colors.

LED-backlit LCDs also support low-profile designs. The old days of using thick and bulky LCDs are long gone. Thanks to LED backlighting, LCDs are now available in thin, low-profile designs, which is why they LED-backlit LCD is such a popular choice for smartphones and other small mobile devices.

Furthermore, LED-backlit LCDs are incredibly energy efficient. Research shows that, on average, LED-backlit LCDs consume about 20% to 30% less power than CCFL-backlit LCDs.