A method and apparatus for storing, reading, and updating information abode a plurality of target objects. The apparatus includes a data reader and a plurality of readable and writable tags, each tag including a memory. The reader produces a modulated interrogation signal or beam for activating and writing...http://www.google.de/patents/US6056199?utm_source=gb-gplus-sharePatent US6056199 - Method and apparatus for storing and reading data
