| 摘要 |
A debit card, such as may be used for operating a public pay telephone consists of a card of a plastics insulating material having embedded in it a number of optical fibres (1) each of which extends between two edges of the card. The fibres are "scrambled" to improve security, and each terminates at one end at a portion (1-10) of the card which is punched out when a unit is used up. There is also a validation fibre (2), which is also broken when the last unit is used up. When the card is read it is not accepted as valid unless this validation fibre (2) passes light. Finally there is a set of other fibres (3), also "scrambled" to convey other data such as unit value. The basic principle can be extended to identify cards or credit cards, in which case no punching out is called for. <IMAGE> |
