Data glasses, also known as head-mounted displays (HMDs), are already a part of daily working life for car designers, secret agents in movies and fighter pilots. They can absorb their wearer into virtual worlds, or else provide the user with data about the real environment. Until now, these glasses could only display information. “We have now been able to make these glasses bidirectional, by which I mean interactive”, says Dr. Uwe Vogel from the Fraunhofer Institute for Photonic Microsystems IPMS, who is coordinating the iSTAR project. “This has enabled us to create new options for personal information management by moving information into the user’s line-of-sight and simultaneously registering interaction by the user”.

Eye-tracker and image display on single chip

This is all made possible thanks to a microdisplay with integrated camera for eye tracking: The user can change the content displayed by moving his eyes in a targeted way or by fixing his gaze on certain places in the image. He can display new content, scroll through menus or move elements in the image without the need for an additional input device. The bidirectional data glasses can in theory be used to make work easier anywhere where people require additional information but often don’t have their hands free to operate a keyboard or a mouse. The Fraunhofer IPMS researchers have integrated the eye tracker and their system’s image display facility on a single CMOS chip. This makes the HMDs small, light, easy to manufacture and cost-effective. In the case of the prototype, the chip, which is just a few millimeters wide, is positioned behind the hinge on the arm of the glasses. The microdisplay image is projected from the arm via a lens to the user’s retina in such a way that the image appears to be about one meter in front of the user. The image must also outshine the ambient light to ensure it can be easily seen against changing and high-contrast backgrounds. This is why the scientists work with OLEDs, as these achieve a high luminance without requiring an external light source.

Fields of application in industry and medicine

The interactive data glasses could make a number of work processes simpler, more efficient and more precise in both industry and medicine. The possible usage scenarios are many and varied – a surgeon checking a patient’s vital signs, MRI or X-ray images is one possibility. Another would be technicians and service mechanics checking construction drawings, instructions or settings.

Some users have already tested conventional HMDs, but were not very impressed with the results. They were mostly deemed too expensive, too heavy, too clumsy or not ergonomic enough. This is where Fraunhofer researchers see the advantage of their bidirectional microdisplay and system. Fraunhofer IPMS is currently working with other partners in the Fraunhofer-Gesellschaft on the next stage of development of the bidirectional glasses.

iSTAR

The iSTAR (Interactive See-Through Augmented-Reality Displays) project was launched in April 2008. The aim of this Fraunhofer WISA project is to develop an eye-controlled, interactive, mobile augmented-reality (AR) system for personalized information management, comprising upto-date hardware components such as bidirectional OLED microdisplays or a bidirectional see-through headmounted lens. As well as the Fraunhofer Institute for Photonic Microsystems IPMS, the Fraunhofer Institutes for Information and Data Processing IITB, for Computer Graphics Research IGD, and for Applied Optics and Precision Engineering IOF are also involved in the project.

Contact:

Dr. Uwe Vogel
Phone +49 351 8823-282
uwe.vogel(at)ipms.fraunhofer.de
Fraunhofer Institute for Photonic Microsystems IPMS
Maria-Reiche-Strasse 2
01109 Dresden
Germany
www.ipms.fraunhofer.de

www.istar-project.org