Flexible displays: In flux

Flexible Displays

Flexible displays are making their way into the consumer technology domain in the form of mobile phones. Does this mean they are ready for commercial use? Tim Kridel poses this question to vendors and potential users.

Foldable smartphones are finally commercial products, starting with the Huawei Mate X and the Samsung Galaxy Fold. Does this mean largeformat flexible displays for professional applications are just around the corner?

There are a few reasons to think so. One is OLED Falls, a giant display that wrapped around the main entrance of LG’s booth at ISE 2019. Rather than a single giant display, OLED Falls consisted of 88 Open Frame OLED displays that curve up to 1,000R. But it’s still a noteworthy milestone, partly because Open Frame OLED is now in its second generation.

Nasser Malik, LG marketing manager for IT solutions, says: “It features advanced innovations that are vital to its application on a wider scale. This has been pivotal in how it has been taken up by designers, integrators and brands and applied in a number of verticals.”

Scaling flexibility

Flexible displays have been in several vendors’ R&D labs for a very long time. The two biggest challenges are figuring out how to manufacture them in volume and designing them so they’re durable enough to hold up in everyday use.

Paul Gagnon, IHS Markit executive director and technology fellow, says: “The manufacturing scale is still a big problem. That’s part of the reason why these displays are so extraordinarily expensive. The manufacturing yields on them are very poor.”

Premium smartphones have used flexible displays for years because they’re less likely to crack, but their flexibility is limited: nothing like the projector screen contortions that most people think of when they hear ‘flexible display’.

Gagnon says: “While [flexible displays] can be made out of both LCD and OLED, they really don’t work well on LCD. You really need to use OLED processes.” OLED is thin as a display structure. As an emissive display, there’s no need for a backlight, colour filter and other things that make a display thicker and thus less able to bend. Corning can make glass that’s really thin to the point of being flexible, but the challenge is also making it durable enough to be flexed and unflexed repeatedly.

To be really flexible, TV-size OLED displays would need to use a plastic substrate, which is difficult to manufacture. Gagnon says: “So, all of the OLEDs used in large-format displays are made out of glass.”

At CES 2019, LG announced that it will start offering a rollable OLED TV by the end of this year. It didn’t specify how tightly it will roll up, but Gagnon thinks the radius will be somewhere between 8-in and 12-in in size. A foldable smartphone costs about USD 2,630 to USD 3,020, depending on the model, which suggests that the rollable TV will carry an equally hefty premium.

Gagnon says: “That model is 65-in. We think it will be priced somewhere close to USD 20,000. By comparison, a 65-in high-end OLED [TV] is about USD 5,000.”

One reason for the price premium is all of the R&D work that goes into creating a supporting structure to ensure precise rolling and unrolling, as well as durability. So, for now, this type of product will be aimed at the ultra-premium consumer market rather than, for example, digital signage.

Throwing a curve

But suppose all of these hardware and cost challenges were solved. What could you do with a large-format flexible display that you can’t do with their rigid counterparts or with alternatives such as projectors?

One possible application is digital signage that wraps around building columns in convention centres, airports and casinos the way that banners and posters currently do. People aren’t used to seeing video on columns, so passers-by might be wowed enough to stop and watch.

Ric Albert, creative director at Grand Visual, a creative services company focused on the digitalout-of- home (DOOH) market, says: “It’s easy to see how flexible displays will become the landmark DOOH sites of the future.

“By expanding the potential to place screens in areas otherwise unattainable, we are maximising the opportunity for DOOH to reach new audiences and break the mould of our current inventory. Imagine turning some of the 360-degree vinyl wraps on London Underground into screens rather than printed material for a truly immersive visual experience.”

OLED Falls also hints at how flexible displays could enable pro AV to expand its nascent architectural role.

Olly Taylor, British Music Experience technical manage r, says: “There are already buildings clad in LED walls. But I can well imagine that architects will begin to specify flexible OLED panels to be used externally in order to create impact or perhaps even to allow a building to blend in to a changing environment as the day progresses.

“I think we’re getting closer to the cliché of being able to change the colour and décor of a room to suit one’s mood. I’m quite sure we will see the technique heavily used in commercial settings, especially retail. I think there is a massive benefit in considering the impact of using flexible displays solely as a light source.”

Others agree about both the architectural impact and the possible opportunities. Paul Childerhouse, group director at Pioneer Group, says: “Flexible displays will be most useful for architectural applications where the display is factored into the interior design of a space and the application is immersive and a big statement for the space.

“The vertical applications would be varied and for customers with a high level of vision from a creative standpoint. Hotels, malls and atriums particularly would be great places to begin to see curved and architecturally driven display design.”

More flexibility—beyond the waves of OLED Falls—would enable more possibilities. Childerhouse says: “If there was even more flexibility within these products, we’d start to work more organically with the environments they are being integrated into, formulating the shape of the architecture. Working with architectural and interior design teams from an earlier stage would enable us to integrate the technology with the curvatures of the building, resulting in the display becoming immersed into the design concept as opposed to current applications, which tend to be experiential or retrofitted to current buildings.”

Flexible displays could be a particularly good fit for live entertainment venues and visitor attractions.

Taylor says: “Once the technology is available in larger formats, it will certainly be used as part of stage sets, etc. with infinity wall-like ability to transform surroundings. I’m quite sure this is where we’ll see the most creative use of the technology, but it is essentially a continuation of current LED wall technology that is in widespread use throughout the live entertainment industry.

“The use of projection is widespread within visitor attractions, but often certain factors such as brightness, cost of ownership and scale can make this impractical. As the cost of flexible display technology comes down, we’re very likely to see this technology replace certain applications previously reserved only for projection mapping, particularly once the transparent and flexible OLED technology is combined.”

Thinking outside the box

To be viable for cylindrical applications, flexible displays have to overcome the cost and other shortcomings of curved LED panels or projectors. Mike Ross, director of BlueBox Technology Solutions, a 2019 Inavation Awards finalist, comments: “The cost of getting a high- fidelity display at a reasonable cost often got them axed from project budgets from the start. Projection on columns often led to complex projector set-ups to not throw away loads of pixels. That meant a higher number of projectors and blending systems, which always looked good on opening but required lots of maintenance as time went on to keep the fidelity of the system.”

Additional opportunities arise if the flexibility is dynamic. Ross says: “Having screens on actuators so they flex in real time with the content—that would be amazing. Additionally, they can be used in more hard-to-reach places where one wants to display content: those small (or large) corners, areas with lots of columns making complex projection difficult.

“Having done a project on a large old ship, finding the right place to put projectors inside the ship to tell stories proved limiting. Being able to place these flexible screens in some of these unique and challenging spaces open up a whole new realm of possibilities.”

Building columns are just one example of unusual locations that flexible displays will enable. Albert says: “What’s exciting about the flexible screens now in the making is that these screens are malleable and will open up the potential locations and uses for screens in the public space. On a basic level, convex screens can extend the viewing arc up to 360-degrees, whilst concave screens can wrap around the audience providing a more immersive viewing experience.”

Ross comments: “I’ve not used too many of them to date, but I did work on a project in retail, and people were blown away by the non- traditional screens that curved above their heads as they walked through the shops. That’s something they’ll always have going for them: a sense of wonder as it’s not something your everyday person would just have in their house.”

Albert says: “Flexible displays allow media owners the opportunity to place screens on curved structures, maximising the size and shape potential of each location. Where screens can blend in with the environment and it feels natural, organic and makes sense. Where flexibility is not a gimmick, but simply, the best shape and viewing experience for the location."