Transverse field annealing process to form E.A.S. marker having a step change in magnetic flux
US5926095A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1998 |
| Grant date | Jul 20, 1999 |
| Priority date | — |
| Expiry date | Mar 18, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/15341
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A marker to be used in an article surveillance system is formed by processing a continuous ribbon of magnetic material having a longitudinal axis. Domains are developed in the magnetic material to produce a wall configuration which includes a plurality of substantially parallel domain walls extending in a wall direction that is canted at least 15.degree. from the longitudinal axis of the continuous ribbon. The continuous ribbon is then further processed to cause the wall configuration of substantially parallel domain walls to remain in a pinned state for values of applied field below a threshold value. The processed continuous ribbon can be cut to produce discrete magnetic elements which exhibit a step change in magnetic flux when the applied field crosses a threshold value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.