Light sensitive or other materials that are adapted to change state and affect reading of a storage medium are used to control access to data that may be stored on optical medium and/or to control...http://www.google.fr/patents/US7660415?utm_source=gb-gplus-shareBrevet US7660415 - Method and apparatus for controlling access to storage media Recherche avanc???e dans les brevets Num???ro de publicat