The invention relates to a method and system for monitoring tray activity in which a tray sensing device detects the presence of a tray in a given location. The tray can be a conventional tray for supporting food articles or can be supported or integral with a food cart. Information from the tray sensing...http://www.google.de/patents/US7489239?utm_source=gb-gplus-sharePatent US7489239 - Method and system for monitoring food tray activity
