Why Your Next TV May Have Mini LEDs

James K. Willcox

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Every year, people shopping for a new TV are confronted with new terms and features promising impressive improvements in performance. They don't always live up to the hype. But this year's hot technology, the use of Mini LEDs in television backlights, could really make a difference in how some high-end TVs look.

Televisions with backlights made up of Mini LEDs promise to deliver improved brightness, contrast, and black levels. The technology has appeared in a few sets from TCL in the past, but at the CES 2021 trade show, LG, Samsung, and TCL all said they'd be introducing a number of new Mini LED sets.

So why all the fuss about LED backlights?

Most televisions use LCD technology. In these sets, the light comes from the back of the screen, or from the sides. The lights are always on, and pixels open and close to let through the right amount of light for each scene. But in very dark scenes, some light always manages to leak through. This can make black tones look gray, and it can create halos around bright objects that appear against a dark background.

One improvement we've seen over the past few years is the use of full-array LED backlights, where the LEDs are arranged across the entire back of the panel rather than just on the edges of the screen. That's combined with a feature called local dimming, where the LEDs are divided into zones that can be separately illuminated or darkened. The result is that dark areas look darker, and you’re less likely to see halos.

But even the best LCDs with local dimming can't quite match the performance of OLED sets. In these TVs, there is no backlight: Each pixel can be turned on and off individually, so if part a picture is supposed be completely black, it can be. The great contrast and black levels have helped OLEDs top CR television ratings in recent years. Mini LEDs could help LCD televisions narrow that gap.

Mini LEDs Improve Local Dimming

Mini LEDs in the backlight take the idea of local dimming much further. By shrinking the size of the LEDs, companies can use more of them packed together into the same area, so these sets can boast thousands of Mini LEDs behind the LCD panel. These, are divided into dimmable zones, but because the LEDs are so small, there can be a lot of them—say a thousand zones, instead of the dozens typically found in even the best LCD sets up until now. And, they can be controlled more precisely to help improve contrast and black levels and reduce halos.

And by increasing the dynamic range of the TV—the difference between the brightest whites and deepest blacks—Mini LEDs can also help boost a TV's HDR performance. That means you'll be able to see all the detail in a darkly shadowed scene.

Combine all this and Mini LED sets could perform more like OLEDs, while retaining some traditional benefits of LCDs, such as better brightness and a wider choice of brands and screen sizes.

The concept isn't entirely new. We tested the first Mini LED model, a flagship 8-series TV from TCL, back in 2019. Last year the feature was also rolled out to the company's 6-series sets such as the 65Q825 and 65R635.

Consumer Reports has been impressed with the Mini LED models we've tested, says Claudio Ciacci, who heads TV testing at CR. "We've seen Mini LEDs can make an improvement in the local dimming feature, with better control of black levels and dark scenes, and significantly reduced haloing effects." In fact, the sets we've tested have done well in our ratings, with top-notch HDR performance.

Mini LED TVs in 2021

The three companies selling Mini LED sets in 2021 haven't talked much about what they'd cost or just when they'd arrive. But they did provide some details.

LG Electronics say it will use Mini LEDs in its top-tier LCD TVs, called "QNED" sets. LG says its largest-sized QNED TVs could use up to nearly 30,000 tiny LEDs, with up to 2,500 dimming zones. These sets will also have two premium color technologies—LG's own NanoCell, and quantum dots.

In 2021, Samsung's Mini LED models will fly the "Neo QLED " banner. These sets include all of Samsung’s 2021 8K QLED models (the QN800A, QN850A and QN900A series), plus its top two 4K QLED (the QN85A and QN90A) series.

Samsung says its Mini LED technology uses LEDs that are 40 times smaller than conventional LEDs. It's also has a new approach, called a “quantum matrix” for precisely controlling the LEDs and directing the light more accurately to prevent halos.

Samsung will also offer its first TVs using an even newer technology, called MicroLED technolog, in 99- and 110-inch screen sizes.

As we noted earlier, TCL earns props for being the first TV manufacture to offer TVs with Mini LED backlights, back in 2019. In 2021, TCL is taking the technology a step further with what it calls "OD Zero" Mini LED technology. In these sets, there's no distance between the Mini LED backlight layer and the LCD display layer, which is supposed to help it perform better in areas such as brightness and contrast than its previous Mini LED technology.

According to TCL, the OD Zero sets will boast "tens of thousands" of mini-LEDs, and "thousands" of dimmable zones. The company hasn't said just which models will use the OD Zero technology and which might use TCL's more conventional mini LED technology.

As usual, we're looking forward to getting many of these new Mini LED TVs into our labs this year for testing to see how much of a benefit they'll have on performance, and if any LCD set can supplant the OLED TV models at the top of our ratings.