Photonics Spectra - September 2009

Glasses provide information
in the blink of an eye

DRESDEN, Germany – In the James Bond film Die Another Day, the titular hero trains for his upcoming mission using virtual reality sunglasses. Researchers at the Fraunhofer Institute for Photonic Microsystems (IPMS) are developing a bona fide interactive display on a pair of glasses that they hope will be worthy of the fictional spy.

A user of the Fraunhofer glasses will be able to look at his surroundings and the display at the same time. Technically, this combination of a virtual reality display and the ability to see the surrounding environment is referred to as augmented reality.

Although virtual and augmented reality head-mounted displays have been around a long time, historically they showed information only passively and were bulky to wear on the head. The Fraunhofer glasses are lightweight and interactive.

The researchers are developing an eye-tracking feature that will enable wearers to influence the content of the display by scrolling with their eyes or by fixing their eyes on a point to select a menu option. A separate group of researchers, at Fraunhofer Institute for Information and Data Processing in Karlsruhe, Germany, is working on eye-tracking algorithms that can distinguish between intended eye movements and random ones such as blinking.

This eye-tracking feature will be useful for anyone needing to work with his hands while using the display, including surgeons, civil engineers and technicians. This option will allow surgeons to operate while viewing x-ray images, or building engineers to look at plans while working on a project. The glasses also connect to a personal digital assistant that can be used for handheld control.

The interactive display consists of or-

ganic LEDs on top of a 19. 3 ; 17-mm CMOS chip, a lightweight combination. In the prototype model, the chip is just behind the hinge on the temple of the glasses, and the bidirectional display projects onto the retina of the wearer so that it appears to be viewed from 1 m away.

The eyeglasses’ final model may have additional optics. According to Michael Scholles, the business unit manager at

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Fraunhofer IPMS, “The challenge is to find an optics design that can be used both for generating the virtual image display and the eye tracking.”

Until spring 2011, the product’s development will be funded by the Fraunhofer central administration under the iStar project. The project has an industry advisory board that includes companies such as EADS, Daimler and T-Systems, which are pilot users of the system.

“We think that first applications will be for professional use (assembly, maintenance, medical). However, within the mentioned iStar project, also a touristy prototype application will be developed. So, yes, we believe that the interactive eyeglasses will be available to the greater public, but only as a second step,” Scholles said.