OLED displays have been generating plenty of buzz for the past few years. But as Tim Kridel found out, vendors are generally mum when it comes to discussing pro-size products. Hardly a week goes by without yet another vendor announcing yet another product featuring an Optical Light Emitting Diode (OLED) display, such as high-end mobile phones and laptops. Yet the selection of commercially available OLED displays for pro AV applications is tiny in terms of size and selection.
The obvious question is, will that change in 2010? Of the six display vendors – LG Display, Mitsubishi, NEC, Panasonic, Sony and ViewSonic – that InAVate tried to ask, none would provide an interview. That silence suggests that vendors are rethinking their launch plans or, at the very least, keeping their cards close to their vest.
If that’s the case, one possible reason is the economy, which has many enterprises and other pro users looking for low-cost products – when they have money to spend on AV at all. In that environment, it also doesn’t help that the larger an OLED display is, the bigger its price premium over incumbent technologies such as LCD and plasma.
For example, DisplaySearch, an independent research firm, estimates that for a cell phone display, OLED has a premium of about 20 percent over LCD. At small-TV sizes, the premium jumps to 70 percent.
Image is EverythingOLED technology is getting traction in the small end of the market because it has several advantages over incumbent technologies such as LCD and plasma:
- Lower power consumption, such as 50 percent less compared to LCD. With energy prices rising in most markets, and many enterprises and government agencies trying to go green, this benefit is evolving from a nice-to-have to a must-have. Lower power requirements also could be a plus in applications where the displays are powered by batteries, such as digital signage on bus exteriors. It’s definitely an advantage for battery-powered mobile phones and laptops, which is part of the reason why those vendors are embracing OLED technology.
- Better colour contrast at different angles. “In general, OLEDs have much better colour contrast on the higher angles than LCDs,” says Sven Murano, senior product manager at Novaled, an OLED manufacturer.
- High contrast ratios. “It should be more than 1,000,000:1,” Murano says.
- Faster pixel switching, which is a plus for fast-moving content such as sports. “You’re at least a factor of 100 quicker with OLED, so you might mimic the pulse-type switching that you have with CRTs as compared to the old type with LCDs,” Murano says.
- Better colour gamut: 100 to 110 percent of NTSC. High-end LCDs and plasmas also can hit 100 percent, while typical ones are around 70 percent, says Jennifer Colegrove, director of display technologies at DisplaySearch.
- More robust performance, such as no need for warm-up, in cold temperatures. “OLED can work in very cold weather,” Colegrove says.
OLED technology also has its share of drawbacks, such as relatively short life spans of about 20,000 hours before the material degrades to the point that brightness suffers noticeably. That’s not a problem for mobile phones and laptops, which usually are replaced before 20,000 hours of the screen being on, and helps explain why OLED technology has a foothold in those markets.
Life spans will increase as display vendors and their suppliers refine OLED technology. For example, earlier this year, DuPont announced a green OLED that lasts more than 1 million hours.
Size is another major drawback. Commercially available OLED displays are limited to about 11 inches, with 14-inchers due out within the next several months.
But that range is a plus for pro AV in one respect: It’s the size of the screen on many laptop PCs, which sell tens of millions of units each year, even in today’s lousy economy. More laptops and mobile phones with OLED screens means more revenue for OLED manufacturers, which then have more money to plough into R&D to develop larger and larger displays. With that trend well underway, vendors expect more and more large displays to move from demos to commercial products.
“I’d say it’s just a matter of time,” says Novaled’s Murano.
Scaling UpAlthough the hefty premium is an enormous barrier to adoption, some vendors are planning to scale up in a big way. For example, at the CEATEC show in October, Mitsubishi Electric demonstrated a 155-inch OLED display for out-of-home applications.
But saying and doing are two different things. One challenge to scaling up is that substrate sizes currently are relatively small. For example, LCDs currently are in what’s known as Generation 11, where substrates are around 2x3 meters.
“The problem [with OLED technology] is that at the moment, the substrate size that people can handle in the processes is up to Gen 4.5, I think, which is 600x700 mm,” says Novaled’s Murano.
So how did Mitsubishi pull off a 155-incher? By making a wall out of multiple, smaller displays.
“They tiled [about] 720 of those small ones, 96 mm x 96 mm [each], to make that,” says DisplaySearch’s Colegrove.
That modular design isn’t necessarily a sleight-of-hand just to get around today’s substrate limitations. Instead, it shows one of the ways that OLEDs could push into the pro AV market sooner rather than later, despite their current price and size limitations.
Mitsubishi says the modular design means the Diamond Vision OLED displays could be installed on a wide variety of surfaces, such as the curve of a building’s exterior or the side of a transit vehicle. In theory, there’s no limit to scaling up, so it’s possible to wrap an entire building.
But why OLEDs when technologies such as LCD and LED are already available? Some users – such as advertisers – might be willing to pay OLED’s premium if the extra resolution gets them stop-and-stare video quality. (Mitsubishi’s demo unit has a resolution of 111,111pixels/m2 and a pixel pitch of about 3 mm.) In other words, with digital signage seemingly everywhere these days, OLED displays could be a way to make ads stand out from the pack.
With a depth of 81.5 mm, Mitsubishi’s demo unit also is about 25 percent thinner than its LED-based Diamond Vision products. But that’s still a bit thick to be mounted on, say, the outside of a bus or subway car, where it’s vulnerable to everything from a driver cutting too close to a building or power-washing equipment. By comparison, U.K.-based Litelogic – which targets outside-the-vehicle applications – has LED displays that are 21 mm thick.
But it’s here that even more trade-offs come into play. Litelogic’s displays have a 12 mm pixel pitch, with 8 mm units in the works. At about 3 mm, Mitsubishi’s product could have an edge in applications that demand high resolution and don’t mind putting up with extra thickness.
More Innovation ComingAcross all types of devices – from mobile phones to TVs – the world wide OLED market was worth about $600 million in 2008, DisplaySearch estimates. By 2016, it will hit $6.2 billion.
The biggest piece of those pies will be mobile phone displays: about $3 billion in 2016. TVs will make up another $2 billion. The rest is in devices such as the viewfinders in broadcast video cameras, where picture quality is important enough to justify OLED’s premium over LCD.
“But for the broad applications – conference rooms and things like that – you’ll clearly need the market to mature a bit more,” says Novaled’s Murano.
Besides the downward pressure that naturally comes from sales volumes, technological breakthroughs also could cut the cost OLED technology. For example, in September, researchers at Japan’s Riken Centre announced a manufacturing process that they believe could make OLEDs as cheap to make as newspapers.
Other innovations are aimed at increasing the perceived value of OLED displays in ways that have nothing to do with picture quality. For example, Germany’s Fraunhofer Institute for Photonic Microsystems (IPMS) has developed OLED displays that have photo-detectors scattered throughout the substrate to sense movement.
Currently Fraunhofer IPMS’ technology is designed for very small displays, such as inside goggles that would be worn by a surgeon, whose eye movements would be tracked to trigger which patient information is displayed. But the researchers say it eventually could be scaled up to larger displays, such as those used for digital signage, where the display detects a passer-by’s hand movements. If so, that technology would be another option for enabling interactive out-of-home advertising.