Identification tags using amorphous wire
First Claim
1. An electronic article surveillance device for interrogation in an oscillatory magnetic field of period T, said device comprising a single piece of amorphous wire, said wire having domains within the inner core of said wire oriented along a direction parallel to the axis of said wire, said wire having length L and an inner core domain wall velocity, V, such that:
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space="preserve" listing-type="equation">L≈
(VT)/2.
2 Assignments
0 Petitions
Accused Products
Abstract
An inexpensive multibit magnetic tag is described which uses an array of amorphous wires in conjunction with a magnetic bias field. The tag is interrogated by the use of a ramped field or an ac field or a combination of the two. The magnetic bias is supplied either by coating each wire with a hard magnetic material which is magnetized or by using magnetized hard magnetic wires or foil strips in proximity to the amorphous wires. Each wire switches at a different value of the external interrogation field due to the difference in the magnetic bias field acting on each wire.
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Citations
1 Claim
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1. An electronic article surveillance device for interrogation in an oscillatory magnetic field of period T, said device comprising a single piece of amorphous wire, said wire having domains within the inner core of said wire oriented along a direction parallel to the axis of said wire, said wire having length L and an inner core domain wall velocity, V, such that:
space="preserve" listing-type="equation">L≈
(VT)/2.
Specification
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- Resources
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Current AssigneeIntermec IP Corporation (Honeywell International Inc.)
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Original AssigneeInternational Business Machines Corporation
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InventorsSchrott, Alejandro Gabriel, von Gutfeld, Robert Jacob, Gambino, Richard Joseph
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Primary Examiner(s)MULLEN, THOMAS J
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Application NumberUS08/909,719Time in Patent Office448 DaysField of Search340/572, 340/551, 340/825.34, 235/493US Class Current340/572.1CPC Class CodesG06K 19/06187 with magnetically detectabl...G06K 19/067 Record carriers with conduc...G08B 13/2408 using ferromagnetic tagsG08B 13/2417 having a radio frequency id...G08B 13/2437 Tag layered structure, proc...G08B 13/2442 Tag materials and material ...
