Theftproof tag
US6229444A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1998 |
| Grant date | May 8, 2001 |
| Priority date | — |
| Expiry date | Sep 14, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F3/08
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A theftproof tag which is effective regardless of the material of the article to which it is attached. There is neither a change in resonance of a resonance circuit nor a decrease in the Q value due to the material of the surface of a theft monitored article, thereby decreasing errors in the operation of a theft monitor. The theftproof tag has a resonance circuit resonating to an electric wave at a specified frequency transmitted from a transmitting antenna, and having a coil unit and a capacitor electrically connected to both ends of the coil unit. The coil unit has a magnetic core member made of a composite material composed of a powder or flakes of a soft magnetic metal, and a plastic, and a winding wound around the periphery of the magnetic core member and connected to the capacitor, a portion of the magnetic core member facing the attaching surface of the article.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.