Smartglasses, or augmented reality glasses, may have found niches in military and industrial circles, but haven't really caught on with consumers for a number of reasons – a major one being that they're extremely conspicuous. To help rectify this, the Fraunhofer Institute for Applied Optics and Precision Engineering (IOF) in Jena, Germany, has developed technology that allows for a more unobtrusive design, while also providing improved functionality.

When Google Glass production ended in January, it had a number of problems; many of which stemmed from the fact it was awkward and alienating to wear. Being so conspicuous, users were also reluctant to wear Glass or similar smartglasses in situations, such as sightseeing, where their ability to overlay virtual information on real objects could be beneficial. Worse, current smartglasses designs aren't just chunky, many also display the information in a corner of the user's field of vision, where it's hard to view. Furthermore, the displays aren't very friendly to users with anything less than 20/20 vision.

What Fraunhofer aimed at was something that could do what current smartglasses do, yet are more discrete, and put information front and center. The new technology consists of an earpiece and an 8 x 15 mm display made in two parts – the image-generating micro-display and the projecting optics. While this makes the micro-display similar in size to conventional smartglass offerings, the optics in Fraunhofer's design are only 5 mm long, which the company says is only a fifth the size of those found in other displays. This is achieved by using many small optics instead of a single long one, which allows for a shorter overall structure.

Many current displays also require users to look to the edge of their field of vision, such as up and to the right, to view the projected information. The Fraunhofer design instead allows users to look straight ahead with the information displayed next to the object of interest. This is achieved by means of a nanoscale lattice structure on a glass plate that acts as a light guide, yet is invisible to the naked eye. This technology not only places the image precisely where desired, but Fraunhofer says it is also suitable to large-scale manufacturing.

Another problem that smartglasses have had is making them usable for people with visual defects that turn the display into an illegible blur. Instead of using adapters or mechanical aids, the Fraunhofer smartglasses are able to compensate for farsightedness at the display level. The user inputs the relevant prescription information into a smartphone app, which sends the data via Bluetooth to the glasses, which adjust automatically. The system can also partly compensate for other problems, such as astigmatism and shortsightedness.

"Our multi-channel approach compensates for farsightedness without any moving mechanical parts, such as the adjustable eyepiece in binoculars, and to set the focus for each wearer by purely electronic means," says Dr. Peter Schreiber, group manager in the Microoptical Systems department at Fraunhofer IOF.

Fraunhofer has developed a demonstrator model incorporating the new technology, which will be on display at the Munich World of Photonics laser trade show running June 22 to 25.

Source: Fraunhofer