Via: Cambridge Consultants
Sunglasses that can show athletes' performance and heart rate data in their peripheral vision have been developed by a German company.
The sunglasses – dubbed "Informance" – display a stopwatch and heart rate at one edge. The extra components needed to do this add just 7 grams to the glasses' overall weight – which is much less than previous head-up displays.
The left lens of the glasses is like that of a pair of bifocal spectacles. But instead of having two areas of different strength, a thin wedge-shaped prism is built into the left edge of the lens. The longest side of the prism faces the wearer's eye, while the shortest side faces outwards on the left side.
A small LED display, powered by a polymer battery inside the glasses' left arm, projects an image into the prism from the side. This image is reflected twice inside the prism before reaching the wearer's eye. The special lens was created by German lens manufacturer Rodenstock, which developed the sunglasses.
Most head-mounted, or "head-up" displays are made for the defence industry, says Mike Hazel, an optics engineer at Cambridge Consultants, who were commissioned to develop electronics for glasses. These are typically heavy, like those found in a fighter pilot's helmet, and display information more obtrusively.
Typically, an image is projected from the end of a component that sticks out in front of the eye.
"If wearable computing is going to be popular you need to provide some information, but not a lot," Hazel says, "our goal was to produce something very light that could be styled into a normal spectacle."
The current prototype picks up information via a wireless link to a digital watch and heart-rate monitor.
The display takes up just 12% of the left eye's field of view, making it barely noticeable when looking straight ahead. The brain also compensates for the overlay by emphasising the right eye view, so it is even less obtrusive in practice. Furthermore, it can run for 12 hours without recharging, he says.
The display is 320 by 240 pixels and could display even more information, adds Dietmar Uttenweiler, head of ophthalmic optics research at Rodenstock. "Showing directions and distances transmitted by a GPS unit is one possibility we are interested in," he says.
Rodenstock plans to turn Informance into a commercial product by 2009. It should cost between 700 and 1000 euros.