An information storage disc, a method of disc manufacture, and a scheme for improved disc surveillance are provided. Generally, the present invention utilizes the geometry and conductivity of a disc's information storage medium to establish an electrically resonant circuit in the disc body. The electrically...http://www.google.fr/patents/US6946963?utm_source=gb-gplus-shareBrevet US6946963 - Secure storage disc and disc surveillance system
