Method and apparatus for tracking items using dual frequency tags
US6542114B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 2001 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Apr 24, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K17/0022
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus (10, 240, 300) includes a signpost (11, 241-256, 322, 612, 623, 626-628, 652, 661, 682, 686, 703) which transmits relatively low frequency signpost signals that are fundamentally magnetic in character, a beacon tag (12, 271-275, 301-316, 395-397, 616-618, 641-643, 653, 656-657, 662-664, 679, 708, 711) which receives the signpost signals and transmits radio frequency signals containing a signpost code (42, 93) from a received signpost signal, and a reader (13, 261, 319, 521-530) which receives the radio frequency signals. One of the signpost and tag is stationarily supported, and the other is mounted on a moveable item. Based on the signals received by the reader, the location of the item can determined with a high degree of accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.