An MP3 player (10) is provided with an image sensor (16) capable of imaging invisible infrared tags (78) on a substrate (70). The tags (78) encode identity data which is directly or indirectly associated in a computer system with one or more audio clips in an MP3 format....http://www.google.fr/patents/US7400937?utm_source=gb-gplus-shareBrevet US7400937 - MP3 player with code sensor
