A ferroelectric optical image comparator has a lead lanthanum zirconate titanate thin-film device which is constructed with a semi-transparent or transparent conductive first electrode on one side of the thin film, a conductive metal second electrode on the other side of the thin film, and the second...http://www.google.fr/patents/US5267179?utm_source=gb-gplus-shareBrevet US5267179 - Ferroelectric optical image comparator
