By Guillaume Chansin

CES is the show to see all the new TV models. While there are a lot of other products showcased (remember that laundry folding robot), the TVs remain the stars of the event. As a result CES has also become a battleground for future display technologies. In recent years the big names in displays have reduced their participation at professional tradeshows to focus their marketing budget primarily on CES.

This year the marketers clearly wanted to pit microLED against OLED. However, don't leave LCD out of the contest yet.

OLED continues to wow

LG, Sony, and Panasonic announced new models in their OLED TV lineup. Last year Sony made quite an impression with their first OLED so it is good news that they are expanding the range.
What truly captured the imagination last week was a demonstration of a rollable OLED TV by LG. With a 65-inch diagonal and a 4K resolution, there was no apparent compromise in specifications (unlike previous demos of large rollable displays).

Although the company did not disclose details about manufacturing technology, it is likely that this panel is still made on glass instead of plastic (glass that is thin enough can bend). LG also showed a 88-inch display with 8K resolution, which meant that the picture looked very sharp no matter how close you were.

Is it important to note that both demos were by LG Display instead of LG Electronics. That means they are only prototypes and there is no product announcement yet. Since LG Display is still the only supplier of OLED panels for the TV industry it is worth paying close attention to where their R&D is heading.

Is microLED the future of TV?

Samsung's attempt to steal the show was with a 146-inch microLED display for home cinema. "The Wall", as they called it, is not the first microLED to be demonstrated at CES. Back in 2012, Sony had a prototype 55-inch TV based on a similar technology (Sony called it Crystal LED).

MicroLED displays such as these are based on an array of tiny LED placed side by side. It is essentially the miniature version of a stadium screen. MicroLED displays can deliver higher brightness than OLED with the same promise of perfect blacks.

Manufacturing is still a challenge though. The placing of each LED in such a high density array requires state of the art accuracy. This leads to two problems. Firstly, a high pixel density is very difficult to achieve. Samsung's demo had a 4K resolution, which is fairly low on such a large screen (equivalent to full HD on a 73-inch TV). If you get close enough you can distinguish individual pixels. Secondly, the display has to be made of small modules tiled together. In the video below, you can clearly see the tiling even under the controlled lighting conditions at the Samsung booth.

It is understandable that Samsung is initially targeting cinema screens with this technology. The typical viewing distance inside a theater makes it a good match with the current manufacturing limitations. Last year, Sony also had a microLED display at their booth and they made sure nobody would get too close. I personally think the Sony demo was more impressive as it was a bigger screen than Samsung's Wall.

But what happened to the QLED screens that Samsung was pitting against OLED in 2017? They have not been very succesful so it seems Samsung wanted the public to focus on the microLED demo. However, the latest model of QLED TV was shown to selected media, by invitation only. The new TV is still based on LCD with quantum dot color conversion, but Samsung has decided to upgrade the backlight with direct lighting instead of edge lighting, thereby addressing the main criticism of the 2017 models.

Quantum dots could be used to manufacture emissive displays in the future but the materials are not ready yet. During CES, Nanosys was showing the latest formulations that can be printed to make electro-luminescent quantum dots. It is a promising technology and we can expect to see more in the coming years.

While OLED and microLED were the big stars of the show, it is important to remember that LCD technology can still deliver very impressive displays when cost is not an issue. Sony's booth had a prototype 85-inch LCD with 8K resolution and 10,000 nits of brightness (more than 10x the level seen on a typical TV). It was so spectacular that Forbes selected it as the winner of CES 2018.

All roads lead to OLED

In mobile phones, OLED adoption is accelerating. Most flagship phones are now using OLED, including the iPhone X. But so far there has been no imperative to replace LCD with OLED. This could change very soon.
Vivo demonstrated the first smartphone with a fingerprint sensor integrated in the display. Vivo used an optical sensor developed by Synaptics which sits directly under an OLED panel (it would not work with an LCD). Although the optical recognition is a little bit slower than a capacitive sensor (700 ms), it works exactly as expected.

In a private exhibition room on the side of the main show, Samsung was showing new prototypes of flexible displays. In particular, it has been reported that Samsung was demonstrating a 7-inch foldable OLED panel to VIP guests. If foldable phones become the new form factor, then OLED will be the only display that can deliver this feature (if you exclude E Ink).

So which display technology is the winner of CES 2018? In my view, OLED wins for now. Whether it is for TV or smartphones OLED displays look amazing and are available now, although you will have to wait before you can buy a rollable OLED for your living room. MicroLED technology may be very impressive but it is not for consumer products just yet. However, I can easily imagine a future edition of CES where microLED takes the crown.