A look at new developments in eye-tracking technology

Displays are for looking at, but increasingly those displays are looking back. The latest example: bidirectional microdisplays under development at the Fraunhofer Institute for Photonic Microsystems (IPMS) in Germany.

The Fraunhofer Institute for Photonic Microsystems in Germany is developing organic light emitting diode (OLED) displays that feature photodetectors, which sense light. The photodetectors are embedded throughout the display and can be used to track movement nearby, such as a person’s eye movements.

Fraunhofer’s system centers around photodetectors, which sense light. Those photodetectors are embedded throughout the display and can be used to track movement nearby — hence “bidirectional.” How nearby and how subtle a movement depends on how Fraunhofer is able to refine the technology over the next year or so, but one goal is to be able to track a person’s eye movements.

Here’s one scenario: A surgeon uses the system in conjunction with a fiber-optic video camera fished inside an organ. The camera feed is displayed onscreen and overlayed with other information, such as the patient’s blood pressure. The overlay also could include virtual buttons that, for example, the surgeon simply looks at to have something happen, such as bringing up a menu of options for a cauterization tool mounted alongside the camera. That design frees the surgeon’s hands to do other, more important things.

Fraunhofer IPMS currently is developing the technology for microdisplay applications, where users wear the displays like goggles. That design could be a good fit for a variety of applications, including surgery, virtual reality, and gaming, as well as tools for physically impaired people.

But the technology eventually could be scaled up for larger, TV-sized displays, too. Doing so would enable the technology to be used in applications such as videoconferencing, digital signage, and industrial design. “In principle, that’s possible,” says Michael Scholles, who’s heading up the project at Fraunhofer IPMS. “Whether it makes sense from an economical point of view is a different question, but technically it would work.”

For years, vendors have been selling displays with built-in video cameras, ranging from computers such as Apple’s iMac to digital signage that tracks the behavior of passers-by to determine whether ads are attracting attention. Like Fraunhofer, other vendors forego cameras in favor of embedding sensors in the display itself. Some of those displays — most of them in the prototype stage — are what’s called “direct-view,” meaning that users sit or stand in front of them, instead of wearing them.

In one, “you can put a business card down on it, and it scans the business card using the sensors that are built into the display,” says Kenneth Werner, senior analyst at Insight Media, which tracks display technologies.

The obvious question is, if those applications are possible today, what value does Fraunhofer’s technology add? The answer depends on the application. For example, in applications where a goggles-based design is a good fit or even preferable, Fraunhofer’s system has the technological edge. Fraunhofer’s technology also could leverage the “wow” factor, especially if it’s eventually scaled up for use in larger displays. For example, although people might be used to interactive displays at the mall or in the workplace, where they gesture to make something happen on-screen, they might be shocked to find this display is capable of tracking their eye movements.

For some users, that feature alone could make them want to spend time with the display. If that display shows an advertisement, then the sponsoring brand might jump at the technology because it’s a fresh way to engage consumers.

Scaling the technology beyond goggles could be key for finding a wide market. “Eyeglass displays are a niche,” Werner says. “I’ve been following aspects of this for a good many years. Every once in a while, people get excited, but it never grows beyond a niche.”

Yet, some niches are deep and lucrative, such as health care and industrial design. “Those are niches, but they’re the kinds of niches where you could see a company making a viable business,” Werner says.

Fraunhofer’s project is scheduled to end in March 2011. Scholles estimates that by the end of 2010, the technology will be refined enough to be turned into commercial products. The technology could make its debut in the healthcare and aircraft industries, based on the types of companies that Fraunhofer both is talking to and has on its advisory board. Regardless of where it ends up, one thing is clear: Success will depend largely on understanding the unique needs of a particular industry. For example, in healthcare, the system would have to be designed so that the overlay includes information and virtual buttons that surgeons would need.

But Fraunhofer doesn’t plan to acquire industry- specific expertise in order to target each vertical. Instead, it probably will license the technology to companies that then would develop versions that meet their particular industry’s needs. “We’re more or less the technology provider,” Scholles says. “So we don’t care so much about the real application at the very end. We can give hints on how to design the overlay, but it’s out of our control what the user does with the entire system and what the final application is.”

Licensing the technology is a common approach for organizations such as Fraunhofer IPMS. “You’re probably better off leaving the system development and marketing to someone who knows a particular application and market very well,” says Insight’s Werner. “That’s what most people do these days.”

In the meantime, Fraunhofer has several things that need to be refined before the technology is ready for commercialization. A major one is increasing the photodetectors’ resolution beyond the current 12 pixels. “You can’t do eyetracking with that,” Scholles says.

Another task is to make the whole system as small and lightweight as possible. That’s particularly important for head-mounted applications because the lighter it is, the longer the user can wear it, such as through hours of surgery.

Instead of liquid crystal display (LCD) technology, Fraunhofer’s system uses organic light emitting diodes (OLEDs), which are slowly entering the mainstream market in products such as portable video players and small TVs. “The Fraunhofer display is basically a normal OLED display; it just has photodetectors on the substrate,” says Dr. Jan Blochwitz-Nimoth, cofounder of and chief scientific officer at Novaled, a German company that’s supplying OLEDs to Fraunhofer. “Otherwise it’s a quite similar technology.”

If Fraunhofer stays on track to have a commercial- ready technology by late 2010, that timing would dovetail nicely with the evolution of OLEDs. Today, OLED displays are relatively small: commercially available TVs max out at 11 inches, while prototypes are around 40 inches. So if bigger OLED displays are available by late 2010, that’s one fewer hurdle for using Fraunhofer’s technology in devices other than goggles.

Regardless of size or application, Fraunhofer’s technology also benefits from OLED’s maturation: More vendors are producing more OLED products — a trend that eventually will drive down the cost of OLED technology, making it practical for a wider range of applications.

“OLED technology is ready, although production needs to scale up,” Blochwitz-Nimoth says. “Fortunately, that’s happening.”

Tim Kridel is a freelance writer and analyst who covers the AV and telecom industries for several publications and research firms. He’s based in Columbia, MO, and can be reached at tim@timkridel.com.