公开(公告)号：GB2313982A

公开(公告)日：1997-12-10

申请号：GB9710025

申请日：1997-05-19

Applicant: IBM

Inventor： SCHROTT ALEJANDRO GABRIEL ,  GAMBINO RICHARD JOSEPH ,  GUTFIELD ROBERT JACOB VON

IPC: G01V15/00 ,  G06K19/06 ,  G08B13/24 ,  H05K1/02

Abstract: A magnetic anti-theft and identification tag 206 for concealing in an article such as a SIMM 115, microprocessor, memory or logic chip or board has an amorphous wire 101 and an array of magnetic elements 201 in the form of strips of foil, wire or magnetic ink. The amorphous wire 101 acts as an anti-theft element which is detectable when passing through an interrogation field and the array of elements provides identifying information in the form of a code which can be read by a sensing head 205. The array may be binary coded in various ways, for example by leaving out or magnetizing selected elements or magnetizing elements in opposite directions 203, 204. The elements may be soft elements driven by an applied local a.c. field from the sensor head. Two parallel rows of elements may be used. Various sensor heads are described, consisting of one or more small magnetic circuits coupled to one or more pickup loops. Some heads utilise the Matteucci effect. The wire 101 may form an integral part of the array for coding information.