Magnetic tags or markers
US6371379B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1998 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Oct 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/00804
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic tag or marker is described which is capable of functioning as a multi-bit information carrying tag. The tag may be attached to an article and then used as a means of identifying that article, generally as it enters or is positioned within an interrogation zone. The tag comprises (a) a first magnetic material characterized by high permeability, low coercivity and a non-linear B-H characteristic; and (b) a second magnetic material which is capable of being permanently magnetized, the second magnetic material being magnetized with a non-uniform field pattern (A, B, C). Detection systems for use with such tags, and write/read system using them, are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.