Can OLED screens move beyond TVs and smartphones?

In our recent look at the state of OLED televisions, we focused on the present—but what about the future?

With OLED (short for “organic light-emitting diodes”), there’s good reason to believe we’ll see far more of the tech in years to come, given its extreme contrast ratios and super-thin screens. To understand just where OLED might be going—and why companies are embracing the tech in different ways—it first helps to understand where OLED came from and how a $100 million deal with Kodak paved the way for our current reality.

Cooking in Kodak's labs

In the late 1980s, Eastman Kodak took a surprising lead on display technology. This was well before personal computing displays of all sizes dominated the market—and at a time when Kodak wasn’t producing a significant number of display panels itself. The company’s work on what it called organic light-emitting diodes received its first major unveil in 1987, and it differed greatly from the other flat-screen display technology of the time, liquid-crystal displays (LCD).

OLED panels place organic materials between electrodes and then activate them electrically via a control circuit to produce light. (One of the electrodes must be transparent for light to shine through to a viewer.) The subpixels in OLED’s earliest screens separately emitted red, blue, and green light, and this color and luminance information was combined to display anything from white to black and all colors in between.

Unlike LCD, this combination of materials doesn’t require backlighting, which means that panels can be, among other things, far thinner and more energy-efficient. However, OLED originally proved more expensive to manufacture than anything from the competition. When the race to thin, beautiful displays kicked into high gear in the consumer market, LCD and LED panels took the lead.

Eastman Kodak continued developing its OLED portfolio with an important upgrade: white-emitting OLED architecture (WOLED). This innovation, which Kodak patented in 2004, addressed a major issue with blue subpixels in OLED panels degrading at a faster rate than red or green ones. Kodak built these newer panels so that every red, blue, and green subpixel worked in tandem with a white subpixel, one in which the natural degradation didn’t include changes to color or brightness information. Kodak advertised this innovation as a way to make screens last longer and to make panel production cheaper and more efficient.

Yet with this technology in its hands, Kodak rested on its screen-manufacturing laurels, leaving its OLED R&D portfolio mostly untapped in the consumer space (with the exception of digital camera screens and overpriced digital photo frames). By the end of the 2000s, the company found itself struggling with the market’s transition to digital photography. That’s a much longer story than I have time to unfurl here, but it’s generally agreed that Kodak was scrambling to stay afloat.

One way it did so was by selling its lucrative OLED IP portfolio to LG in 2009. At the time, the $100 million deal went uncontested by LG’s rivals. There was no bidding war, likely because other companies didn’t see return on that kind of investment, but the move quickly made LG the major player in OLED TV screens.

Costs and matrices

LG isn’t the only OLED player in the world, mind you, but it is currently the only OLED TV manufacturer in the United States, and it also makes the panels sold by Panasonic, the only other OLED TV player in the international market.

LG has said on the record that the white OLED technology purchased from Kodak gave it a giant lead over other companies’ “RGB OLED” TV panels. LG says its panels cost far less to manufacture than the competition’s—the panels’ crystals are easier to line up in a cost-effective manner.

Others may well catch up in the larger-screen OLED space in the near future, of course. When that happens, it stands to reason that competitors, particularly the deluge of Chinese companies entering the TV manufacturing space, will combine aggressive discounts and other innovations to steal attention away from LG.

For now, many manufacturers do produce panels with OLED technology—though you may better know these as AMOLED displays. (You’ll find them in smartphones from Samsung, Huawei, and Google.) Their main difference from larger-panel OLED displays comes from that “AM” prefix, which means “active matrix.” This refers to the process of sending electrical current through the panel for the sake of pixel illumination, which used to be a less-efficient “passive matrix” process. The older way proved too power-hungry and slow for the kind of quick-performance screen refreshes needed in a smartphone. (LG doesn’t advertise the kind of matrix employed in its latest OLED TVs, but based on what we know, it can probably be described as a combination of AMOLED and WOLED.)

In the mobile-screen space, AMOLED and in-plane switching (IPS) LCDs continue to battle for supremacy, with each offering different color, brightness, darkness, thinness, power, and performance advantages.

Bends and curves

OLED’s biggest advantage over LCD (and its derivative technologies, LED and IPS) is how its pixels can be arranged in all kinds of crazy ways.

OLED panels do not require back-lighting or squared displays. Manufacture however many diode crystals you want, set them within a rigid grid—shape and size is your choice—and make sure they have electrical current connected. Where you go from there is your choice.

Want to make a curved screen? Sure thing. How about a continuous panel with bends, curves, and sudden changes in angle and orientation? Knock yourself out. You can even place a grid of OLED crystals in a transparent display—which would let you align an illuminated image along the edge of, say, a staircase.

https://youtu.be/i-nOnNnlHt0

As the owners of Kodak’s WOLED IP, LG has a vested interest in showing off exactly how its screens’ flexible attributes look in practice, which is probably why the company rigged up dozens upon dozens of curved and wavy OLED screens all over the N Seoul Tower in South Korea last year. The above video demonstrates how impressively these screens can be arranged, but it also reveals one key weakness: logistical limits on individual panel size.

While the tunnels and walls at N Seoul Tower stretch on for long distances, LG has opted to cover them in a ton of screens connected to each other, instead of super-long or extra-wide panels. Each individual screen can bend and turn at different angles and curves, but manufacturing a single, gargantuan panel must not be anywhere near cost-effective.

OLED screens enjoy a very small footprint, both in terms of width and in required bezels. But if you look at that incredible installation and think you’re getting a hint of some futuristic cityscape akin to Blade Runner, think again: this South Korean installation, and others like it, are typically indoors for a reason.

Currently, brightness maximums on consumer-grade OLED screens max out at around 800 nits in concentrated zones of a single panel, compared to about 1,500 in high-end LED panels. Because of how the subpixels’ organic elements are activated by electricity, OLED doesn’t scale up well in terms of super-bright options, so you shouldn’t expect these kinds of bendy, curvy screens on billboards or outdoor signs meant to be easily visible from long distances.

This South Korean installation doesn't show off OLED's transparency chops. OLED, like other screen technologies, can light up nicely within mirrors (to add visible clocks and weather alerts to the edge of your vanity, for instance), but it can also uniquely insert images and text into mostly transparent panels—essentially jazzing up the panes of glass in storefronts and museum displays.

OLED: Could the D stand for "drones"?

OLED’s most promising future use case stems from its craziest party trick, demonstrated at 2016’s Consumer Electronics Show. There, LG trotted out a large, shiny piece of OLED “paper,” which the company invited people to pick up and bend in their hands.

This screen-paper concept worked because of its incredible 0.18mm depth, which was thin enough for rolling into a tube without disrupting the OLED innards’ ability to distribute electricity and color/luminance information. With white gloves on, LG representatives carefully rolled and moved the paper while images continued to play on the screen, fed from cables plugged into one of its edges. (Attendees could pick up and play with another one of the screens that had no signal plugged into it.)

Of course, if something like this screen ever lands in consumer hands, there’s the issue of actually driving images to it. Connecting modern cables like HDMI or USB would require attaching a relatively bulky device to the thin screen, and the screen casing would need to make room for a battery or other power source. That same CES demonstration also ran on an 18” TV whose revolution was close to 720p—so we imagine these ultra-thin panels need a little more R&D time before approaching, say, 4K resolution.

The most obvious use case for such a device—namely, as a portable smartphone or tablet display that could be rolled up and placed in a bag or a pocket—might actually be feasible, because flexible capacitive touch panels already exist. However, a floppy screen isn’t an ideal on-the-go way to view content. I could imagine something working like a high-tech “slap bracelet,” with a support plate that could firm up at full extension or roll up with a button tap, but pixel density will really need to increase before such a device is useful for tap-friendly smartphone interfaces.

How much crazier could this tech get? I can’t help but imagine OLED wearables. Combining and cutting a few of these flexible sheets into wearable form factors, like shirts and pant legs, might just seem like the stuff of wild costumes. But research into active camouflage systems has already begun, with body camera capture data being used to display visual information on the opposite side of an object to make it look see-through. OLED panels could work here, thanks to both their bendable properties and their de-blur potential. (Less blur will make moving camouflage imagery look more convincing.) While an OLED-and-camera suit may be a long way off for most human wardrobes, smaller and more controlled shapes—like those of robots and drones—could fare a little better for such an experimental use.

A smart watch, on the other hand, may be a better candidate for OLED’s bendable properties in the near future. Think of it: a watch whose entire wrist-wrapping portion could light up with text, numbers, and notification icons could go a long way toward differentiating the smart watch sector. If that smart watch takes advantage of OLED’s pure-black capabilities, and thus the power savings from unlit pixels, that would only improve its battery life. An OLED smart watch could also take advantage of its selective pixel placement and transparency perks in handsome ways.

Eyes on CES 2017

Outside of standard portable and TV screens, the OLED world contains more dreams than guaranteed use cases at this point. LG’s grip on the WOLED standard will likely remain unchallenged in the near future, but that doesn't mean other companies are resting on their laurels. Samsung, for example, has its own OLED products and the LED-related "quantum dot" standard (which is popping up in consumer-targeted products, since quantum dot panels are said to be cheaper and more efficient to produce). Will this trend have a spillover effect? Companies may avoid or ignore the bendy-panel possibilities of OLED if they’re not already manufacturing and fine-tuning more mainstream OLED products.

But OLED acceptance is starting to ramp up in the consumer market, and that means all eyes will be on next month’s CES in Las Vegas to see what LG and its competitors have cooked up for OLED in 2017. We’ll be in Vegas for the show—and will be sure to report back on whatever crazy OLED creations we stumble upon.