The Customer Activated Multi-Value (CAM) card provides a customer with a primary use as a transaction card which can be further activated to have a secondary use as a credit card. The CAM card can be activated as a transaction card or as a transaction card with a credit card feature. Activation of the...http://www.google.com.hk/patents/US7707111?utm_source=gb-gplus-share專利 US7707111 - Customer activated multi-value (CAM) card
