tim's journal

Invisible cloak via retro-reflectum

I've been thinking about how to do this for several years - but someone has actually gone and done it! Imagine, an invisible cloak just like Frodo. The BBC has the scoop. The inventor is Susumu Tachi, who started developing the idea in 1977. He is a professor at the University of Tokyo in the Deptartment of Information Physics and Computing. The cloak was on-exhibition this month in San Francisco.

So what is retro-reflectum? Also referred to as retro-reflective material, the term brings up absolutely nothing on Google. The answer can be found in the latest of Professor Tachi's patents, US6341869.

A projector is disposed at a position that is optically conjugated to a position of eyes of an observer. The projector projects an image to a screen that has retroreflection function so as to provide information of virtual space to the observer. If a real object such as a tactile sense provision device that is to be shielded by the virtual space exists, a part or the whole of the real object is optically hidden from the projection of the projector by a shielding member having retroreflection function, for example, by placing a shielding screen on which a retroreflection material is coated, or by coating the retroreflection material.

Demonstrations of the technology can be found on their project website. So cool!

Posted by torque at June 14, 2004 9:50 AM | TrackBack