Article recognition and verification
US6598793B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1999 |
| Grant date | Jul 29, 2003 |
| Priority date | — |
| Expiry date | Jun 30, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07D7/04
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A method for checking the authenticity of a security article of the type containing magnetic particles having a magnetic saturation field Hs being greater than 100 A/m. The method includes the following steps: (a) generating an alternating field of one or more fundamental frequencies; (b) subjecting an article to be detected to the field; (c) detecting a detection signal emanating from the article to be detected; and (d) examining the detection signal for the presence of any particular higher harmonics of the fundamental frequencies or of any linear combination of the fundamental frequencies and of the harmonics, the particular harmonics or the linear combination being indicative of the presence of the magnetic particles. The method is applied at point of transaction locations, where the article to be detected is brought into close proximity with a sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.