For LED Screens Within Public Reach, The Future Is Hardened
November 7, 2018 by Dave Haynes
There’s no question that direct view LED displays have seen a huge uptick in marketplace adoption in the last couple of years, but one thing that’s been holding back even broader adoption is durability.
In simple terms, conventionally-made LED displays are fragile. That’s not much of an issue if the displays are up on a wall or set back in some way that minimizes the risk they’ll be bumped or be in reach of curious, prying fingers.
Put an expensive fine-pitch LED in a flagship store, shopping mall concourse or airport terminal courtyard, within public reach, and they’ll inevitably get damaged. The little surface-mounted LEDs get inadvertently scratched off by roller bags, or flicked off as someone breezes by the edge. People in this industry may know the screens are fragile, but the general public doesn’t.
Fixing those bumps and scratches – repairing or more likely replacing the tiny LED light packages – is complicated, time-consuming and costly.
About this time last year, I went over to Taiwan and Shenzhen, China to see how LED displays are made, and got a glimpse of what was coming – hardened LED displays that would stand up to all the inevitable bumps and scratches. They could, as the old saying goes, take a licking and keep on ticking.
A year on, a handful of Asian manufacturers have products coming out of R&D – ready to market as a new, and at least in some respects, better approach to LED displays.
I was in Montreal yesterday to get a look at one of those products – a 1.5mm fine pitch display manufactured by the publicly-traded Chinese firm Ledman. A company called AVL Media Group – part of a larger AV distribution company (Intellimix) based in Montreal – has the Canadian distributorship, and brought me in, wanting my opinion on whether what they have has potential.
The manufacturers are understandably tight-lipped about how they make these hardened displays, but essentially you have LED light modules dipped or coated and thereby sealed in some sort of hardened solution that protects the lights but allows their heat out and doesn’t affect light output or viewability.
Switching To Chip On Board
In the case of Ledman, the displays use a different manufacturing process called Chip On Board (COB). With COB, the teeny LED lights are attached right to a printed circuit board instead of being “packaged” first – with the LED wired, bonded and encapsulated for protection as individual units. You can typically pack a lot more LEDs into the same physical footprint using COB, and while I don’t really know how Ledman does things, I’d imagine their COB light modules are more rapidly manufactured.
One of the ongoing objectives in the LED display business is to mass transfer LED lights to module, instead of robotics machines picking and placing the lights. The machines are blindingly fast at doing that, but when there are 1,000s or millions of lights, making modules takes time.
What comes off the Ledman line are thin strips or slats about the dimension of energy bars, that have the tiny LEDs on one side and the electronics on the underside. They are hardened and therefore durable. Those slats are put together in arrays that end up looking like the conventional LED “cabinets” that we all see at trade shows. Those cabinets are tiled together to create video walls.
The difference, as mentioned earlier, is that you can beat on these units and nothing happens. They are IP65 rated, so you can toss a glass of water at the display and bad things don’t happen.
What I Saw
The 1.5mm I saw looked really good. It just went up at the Montreal warehouse, and the techs were still tweaking the settings to get it fully calibrated, and therefore fully uniform in its look. If it was running whites or very light colors, you could j-u-s-t see a patchwork quilt effect that showed the slats. The deeper, saturated colors that are the way to go, content-wise, with LEDs looked great and the visuals looked very solid. The controller card doesn’t support HDR, as some LED displays now do, but the blacks were pretty black.
You could look at the screen way off to the side and the visuals still held together nicely.
I don’t spend my days carefully scrutinizing who has the best looking LED displays out there. I don’t have the technical background or perspective to get much beyond that looks great or that looks crappy. In the case of this technology, I think as long as it falls in the looks good-to-great category, it’s a win. That’s again because of the durability.
One argument against chip on board-based displays is that if one of the lights is damaged, the whole slat needs to be popped out and repaired or replaced. It can’t really be done on site – meaning the whole cabinet needs to go back to the factory. The counter-argument is that damage is far less likely.
Changeable, Active Surfaces
These hardened displays allow people like architects, commercial space designers, visual merchandisers and experiential media companies to think about LED as an alternative to stone, tile, wood, brick and paint on walls and other surfaces. Instead of a finished surface they’ll select and their clients will have to live with for many years (unless budget is not an issue), designers can scheme in surfaces that are changeable and active.
That means an office tower lobby can change its look on demand. In the passenger arrivals concourse of an airport terminal, the walls and ceilings can be dynamic – even changeable by the inbound flight.
More to the point, the owners don’t have to worry that their very expensive investment is at constant risk of having LEDs damaged, and steadily having displays under repair. It looks bad and the service bills add up.
AVL is just starting to talk about and show its Ledman tech to integrators and solutions providers. The company has a long background in LED displays for concerts and events, and this sort of fixed display technology is relatively new to them.
Andrew Hope, the company’s managing director, figures they have a 12-18 month jump on the market. I had heard from an LED guy I really, really trust, who said he’d seen the Ledman product, and said it was quite good, but not … quite … there in terms of its look. Hope told me there is a new gluing process Ledman will be using that makes the subtle slat look largely disappear.
That should be evident by the time ISE comes around, assuming the company is showing there, directly or via a partner/distributor.
There are other companies with product. The Chinese manufacturers CreateLED and Cedar also have hardened products they’ve shown at some recent trade shows, but my experience with them is that they were “Oh, by the way …” kinds of products, and not core. I’d walk into booths and have to ask, “Is that what I think it is?”
In the case of Ledman, if this is a card game, the company appears to be going all-in on this tech.