摘要 |
A carrier for display fields or value characters, such as a credit card, contains optically readable display fields which can be erased by the effects of heat or which can at least be changed permanently in optical terms, and a storage layer for storing energy for the purpose of producing the thermal energy required for the heating effect at the location of the display field to be erased. In this way, the energy stored in the storage layer, which energy corresponds to at least the erase energy required, is released by the supply of an initial energy which is less than the erase energy. If a photoconductive layer is used additionally, the reading light beam can also serve to produce a local electrical current I in the region of the display field to be erased, wherein the current I produces sufficient thermal energy in the form of initial energy to set in notion the reaction process in the storage layer and to release the thermal energy stored therein. An arrangement of this kind can be used advantageously in instances where only a small electrical output is available for inducing a cancellation process. |