A purchase monitoring device, to be used by a shopper in a self-service store having items with bar codes which identify the item and its price, the device including primarily a portable handset having a bar code scanner which enables pricing and identification data of a selected item to be displayed...http://www.google.fr/patents/US5345071?utm_source=gb-gplus-shareBrevet US5345071 - Shopper's purchase monitoring device
