Say Hello to OLED
By Jeff Goldman, Tue Jul 01 12:30:00 GMT 2003

OLED displays are brighter and sharper than LCDs, they're cheaper to produce, and they don't require a backlight. Say hello to a whole new way to look at your phone


Standing in line at a New York restaurant last month, Kodak spokesman Joe Runde recalls, a woman far ahead of him in line answered a call on her mobile phone. "Even from where I was, I could see the screen," Runde said. "And someone behind her asked, 'Where did you get that phone? That's the first phone I've seen that I could read-and I'm not even using it!'"

What made the phone unique? It had an OLED display.

Organic light emitting diodes, or OLEDs, offer enormous promise for mobile technology. Because they're self-emitting and don't require a backlight, they're brighter and require less power than LCD displays. They can also be read from a much wider viewing angle than LCDs, they cost less to produce, and they can even be made on plastic instead of glass.

Perfect for Phones


The first OLED displays have been passive matrix rather than active matrix, most notably in simple mobile phone sub-displays showing basic data like time or caller ID. According to the research firm iSuppli/Stanford Resources, 3.7 million passive matrix OLED sub-displays were sold last year, with over 10 million expected to be sold in 2003.

But the technology's true potential lies with active matrix displays that deliver high resolution graphics for photos and video. The first consumer device to incorporate an active matrix OLED display, the Kodak LS633 digital camera, was released in March and immediately won attention for its brightness and clarity.

Kimberly Allen, Director of Technology and Strategic Research for iSuppli/Stanford Resources, says the Kodak camera was a major breakthrough for the OLED market. "If you look at that camera panel, you can imagine seeing it on a cell phone," she said. "It demonstrates that OLED can do something like that, that it really can be manufactured that way."

Stewart Hough, Vice President of Business Development for the OLED developer Cambridge Display Technology, says OLEDs are perfect for displaying web pages, photographs, and video on mobile devices. "The more the phone becomes a multimedia device, the more critical the visual performance will be," he said. "That's where OLEDs will have an advantage."

Manufacturing Challenges


Still, there are a number of hurdles to be overcome before OLED displays can replace LCDs in mobile phones worldwide. According to iSuppli's Allen, durability is one key issue. "The lifetime of these displays is a bit limited," she said. "They will tend to degrade over time: they'll have poor pixels, lose their brightness, or shift in color."

In the long run, OLEDs will offer a significant improvement in power consumption, but for now, particularly for active matrix displays, that reward has yet to be realized. "Because OLEDs are still fairly immature and the materials haven't quite been optimized, they end up using about the same amount of power as an LCD right now," Allen said.

And because OLEDs are only being produced in small quantities, price is currently an issue as well. But according to CDT's Hough, that too will improve over time, eventually becoming an advantage for the technology. "In equal production volume, there are fewer process steps, material cost is lower, and the capital equipment is less," he said.

To encourage production, companies like CDT are developing processes that enable LCD manufacturing facilities to be adapted to make OLEDs. "LCDs are getting very commoditized, and people are looking for differentiation," Hough said. "If they could add a new technology to their product line for less than 20 percent of their initial investment, there's some commercial benefit there."

Curves in the Right Places


Ultimately, says Kodak's Joe Runde, the true promise of OLED lies in the plastic display. "One of the things that's really exciting about OLED is, unlike LCD where you have a liquid crystal layer and you need a backlight, OLED enables you do to things on a flexible substrate," Runde said.

John McMahon is Vice President of Sales and Marketing for Vitex Systems, a company which has developed a protective barrier system for OLED displays. "OLEDs are extremely sensitive to moisture," he said. "Today, they make the OLED display on a glass substrate, then they glue a metal can or a glass lid on top to keep the water out."

That results in a thick, heavy display, a significant issue for any mobile device. But Vitex has developed a film three microns thick which offers the same moisture permeability as a sheet of glass. The OLED display can either be built on glass and protected with Vitex's coating, or it can be built on plastic with the coating on both sides.

And that, McMahon says, is what's really exciting about the technology. "The holy grail for the display industry for the last 20 years has been the flexible display," he said. "They've never been able to do it, because water goes through plastic. Now, for the first time, the display maker can actually make a plastic display, which opens up all sorts of applications that don't exist today."

Not only does that make the display thinner and lighter, it enables far more creativity than glass allows. "If you look at Nokia phones, they're all curves," McMahon said. "It's hard to find a straight line, except for the display: except for the thing you're looking at all the time. If you could just stamp out the display in plastic, you could have an oval display, a round display-and it doesn't have to be flat, either."

It will take some time before OLEDs can hope to replace LCDs, but ultimately, iSuppli's Allen says, the consumer experience will drive demand. "OLEDs just look really good," she said. "They have beautiful color, they're bright, and they're very high contrast. Everyone wants one when they see one."

Jeff Goldman is a freelance writer covering a wide range of topics for a number of online journals. He currently writes regular articles for Internet.com's ISP-Planet. Brought up in Belgium, Jeff spent the last decade in New York, Chicago and London; he now lives in Los Angeles.