INDICIA SYSTEM FOR CREDIT CARDS AND THE LIKE

摘要

A system for imprinting indicia in binary form on credit cards and similar plastic members which includes a printing mechanism for printing two tracks of clock or synchronizing pulses and two tracks of data pulses on spaced portions of a credit card. One data track is recorded in such manner that it is a complement of the other data track in order to provide at least 100 percent redundancy. A reading system is also disclosed and which involves a gating structure for determining true states of the complementary data in each of the data tracks at clock pulse time. In addition, the reading system compensates for a condition of skew in the printing or in the reading of the card.