What's the Best Backlighting for LCDs?
You can't choose a liquid-crystal display (LCD) without considering the backlighting. All LCDs require backlighting. The liquid pixels within them aren't electroluminescent, so they can't illuminate themselves. Instead, the liquid pixels require external illumination. The system responsible for producing this illumination is known as the backlighting.
The Basics of LCD Backlighting
Most LCDs feature bulbs behind the pixel layer. These bulbs serve as the backlighting. In some LCDs, the bulbs are arranged in rows and columns. In others, they are only attached to the perimeter edges.
The bulbs will illuminate the pixel layer in front of them. They'll generate light that shines through the pixel layer, thereby creating visible images. While all backlighting systems consist of bulbs, though, different LCDs use different types of backlighting.
CCFL vs LED
There are two primary types of backlighting for LCDs: cold-cathode fluorescent (CCFL) and light-emitting diode (LED). In the past, CCFL was the primary type of LCD backlighting. CCFL bulbs are similar to regular fluorescent bulbs. They contain low-pressure mercury vapor. As electricity travels through the CCFL bulbs, the mercury vapor will release ultraviolet (UV) light.
LED backlighting is a newer type of LCD backlighting. LED bulbs don't contain low-pressure mercury vapor. Instead, they consist of small diodes that illuminate in response to an electrical charge.
It's important to note that there are several different types of LED backlighting used in LCD. Some of the most common include edge-lit, direct-lit, full array local dimming and local dimming. Regardless, they all leverage diodes that illuminate in response to an electrical charge.
