Now you see it …

Automotive Design & Production, Jan, 2005

Researchers at the University of Tokyo's Tachi Lab (http://www.star.t.u-tokyo.ac.jp) have figured out a way to keep a car's roof pillars from obstructing the driver's view: they make them disappear. This technological sleight of hand is achieved by mounting cameras on the outside of the pillars and connecting them to small projectors in the interior.

The images from the cameras are projected onto the pillars which makes them seem transparent, since the driver can see the surroundings as if the pillars were not there. To make the effect work properly the pillars are sheathed in a retro-reflective material that only reflects light back in the same direction as its source, keeping the image clear even in bright sunlight. (This material is the same as that used in the films that cover traffic signs allowing them to shine brightly at a distance.) There is no working prototype for cars yet, but the researchers have been demonstrating the technology's potential by doing an invisible man impersonation on Tokyo street corners with the help of a retroreflective raincoat. A viable vehicle-based system would face the significant hurdle of cost-effectively applying miniature cameras and projectors, but automakers may find it worth a little investment to be the first to produce an invisible car.