MAGNETIC DATA CARRIER

摘要

A portable magnetic data carrier (10), e.g. a card or ticket, is disclosed. The card or ticket comprises a magnetic zone (11) which in use carries magnetically encoded data, and which contains magnetisable material (12) of a first, relatively low coercivity (C1) and magnetisable material (13) of a second, relatively high coercivity (C2). Such data carriers can be used as tickets for use with non-contact magnetic heads in, for example, entry and exit gates for mass transportation systems. The lower coercivity material in the ticket is re-written with data each time the ticket is used, during which the higher coercivity material remains unaffected. Thus the higher coercivity material can contain invariant data which is not susceptible to corruption during continued use of the ticket.