Backlighting is an important part of a liquid-crystal display (LCD). Whether it’s a computer monitor, a tablet, human machine interface (HMI) or any other LCD, it will rely on a separate lighting system to produce illumination. Known as backlighting, this lighting system will illuminate the LCD’s pixels so that it produces visible images. There are different types of backlighting systems for LCDs, however, two of the most common being direct light-emitting diode (LED) and edge LED. What’s the difference between direct LED and edge LED backlighting exactly?
Overview of Direct LED Backlighting
Direct LED backlighting is defined by its use of both rows and columns of small LED bulbs. Also known as matrix LED backlighting, it lives up to its namesake by forming a grid or matrix of LED bulbs. Behind the the top glass layer, as well as the liquid pixel layer, is a grid of LED bulbs. When the LCD is turned on, the bulbs will activate while producing illumination that beams through the layers above it.
All LCDs require backlighting. Unlike with organic LED displays, LCDs don’t have self-illuminating pixels. Rather, their pixels must be illuminated from a separate lighting system, which is the backlighting. Direct LED backlighting is one of the most common lighting systems for LCDs. It features horizontal and vertical strips of LED bulbs. During use, these LED bulbs will illuminate the LCD’s pixels.
Overview of Edge LED Backlighting
Edge LED backlighting, on the other hand, consists of a perimeter of small LED bulbs that are placed along the edges of an LED. They don’t have both rows and columns of LED bulbs. While edge LED backlighting still uses LED bulbs, it only has LED bulbs along the perimeter.
Most edge LED backlighting consists of LED bulbs along all four edges of the LCD. With that said, some of them may only have LED bulbs on two of the edges, such as the left and right edges. Regardless, they all use LED bulbs to produce illumination.
Differences Between Direct LED and Edge LED Backlighting
Both direct LED and edge LED backlighting are designed to illuminate an LCD’s pixels. The main difference between them lies in their placement. Direct LED backlighting consists of bulbs that are placed in a grid or matrix. Edge LED backlighting, conversely, consists of bulbs that are placed along the perimeter.
Because it uses a grid or matrix of bulbs, it shouldn’t come as a surprise to learn that direct LED backlighting produces more uniform illumination. It doesn’t suffer from bright or dark spots. With direct LED backlighting, LCDs receive an even amount of illumination throughout their pixel layer.