The invention disclosed herein is directed at embodiments of a piezo electric switch having a combination of a lamp, a housing, a piezo element, a printed circuit board assembly, a lamp housing and a plunger and a second embodiment of a piezo electric switch having a combination of lamp element, a housing...http://www.google.fr/patents/US5442150?utm_source=gb-gplus-shareBrevet US5442150 - Piezo electric switch
