While the technology behind LED TVs isn’t entirely new, we’re still fascinated with the difference it has made in the viewer’s entertainment experience. Similar to an LCD TV, developers decided to add light-emitting diodes instead of standard cold-cathode fluorescent lights (or CCFLs) to illuminate the screen, giving them a few advantages.
In all actuality, an LED TV is really just a different type (but very-much upgraded version) of an LCD TV. So what are LED TVs, and why are they so much better than the original LCD?
Before we get into it, it should be known that this option has been almost completely discontinued besides the few cheaper LCD TVs due to CCFLs making the product cheaper to manufacture. Cold Cathode Fluorescent Lamps (CCFLs) use a single, straight glass tube. Sort of like a fluorescent lamp. The tube contains a low-pressure mercury vapor that produces an ultraviolet light.
Due to us humans not being able to actually see ultraviolet light, a coat of phosphorus is added inside the tube in order to converts it to a visible bright, white light we can actually see. Unfortunately, this older version causes the picture quality to suffer a bit, thus the new technology created.
Full-array backlighting is pretty much how it sounds: an array of LEDs spread out across the back of an LCD screen. Due to the span of lights, LEDs can be lit or dimmed in specific zones to better adjust to the viewer’s picture, especially when it comes to contrast and black levels.
These LEDs illuminate the LCD pixels which are located along just the edges of the television. In order to illuminate the screen, these LEDs face inward toward the center allowing the models to be very thin, light, and more cost effective. This can effect some of the picture quality, especially black levels, but is really only noticeable when there’s a dark scene.
Local dimming is extremely important when it comes to picture quality. It’s what allows the screen to adjust to deep blacks, helping the contrast. It achieves this by dimming the backlight (LEDs) behind parts of the screen that are displaying black. This makes blacks appear darker on those areas of the screen, which are perfect for darker scenes in movies and TV shows.
Local dimming significantly helps LCD-based TVs improve their contrast quality to match Plasma (RIP) and OLED TVs, a feature that wasn’t available with CCFL LCDs. The quality of the local dimming effect does highly depend on the type of backlighting your LCD uses though, so be sure to know what the illumination type is for your TV.
Longevity & Efficiency
Some of the top advantages of having an LED TVs are the light efficiency, and LED TVs are typically much easier to replace, making them last much longer than OLEDs and LCD-CCFLs.
Now, there’s even QLED TVs. This is in the top tier of LED TVs, featuring an updated illumination technology compared to its ancestor LED LCDs. The Quantum Dot material used increases its efficiency, giving these models a wider grayscale range, enhancing color and HDR.