In a retroreflective display device comprising at least a surface-protective layer, information display layer, retroreflective layer and a back-protective layer, on or between these layers radio frequency identification unit or units enclosing radio frequency identification integrated circuit or circuits are disposed, and communication antenna or antennas which are connected to said radio frequency identification integrated circuit or circuits are installed. At the back of the retroreflective layer an illuminator is disposed. The retroreflective layer is retroreflective to the light coming from the front of the sign and is transmissive to the light from the interior of the sign.

 
Web www.patentalert.com

< Radiation image information detecting method and apparatus

> Magnetic head with a narrow spacing between magnetic shields at air bearing surface

> System and method for creating a market map in an electronic trading environment

~ 00518