Deactivateable resonant circuit
US5861809A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1997 |
| Grant date | Jan 19, 1999 |
| Priority date | — |
| Expiry date | Sep 22, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49149
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A resonant tag used with an electronic article surveillance system for detecting the presence of the tag within a surveilled area utilizing electromagnetic energy at a frequency within a predetermined detection frequency range includes a resonant circuit capable of resonating at a frequency within the predetermined detection frequency range. The resonant circuit includes an inductor formed at least in part on a surface of a dielectric substrate of the tag. The inductor is formed with a discontinuity or gap, causing an electrical open circuit. The open circuit is closed with a fuse secured proximate to the gap and wirebonded to the portions of the inductor proximate to the gap. The fuse is melted by a current greater than a predetermined level flowing therethrough. Such a high current may be induced in the inductor by an external electromagnetic field. Melting of the fuse causes an open circuit condition, which alters the frequency at which the tag resonates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.