System and method for detecting the passage of a person or an object through an entry-exit of delimited space
US6966491B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 14, 2004 |
| Grant date | Nov 22, 2005 |
| Priority date | — |
| Expiry date | Jul 14, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C9/28
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
There are described a system and a method of detecting the passage of persons or objects through an entry-exit (4) of a delimited space (2). The direction of passage is detected on the basis of the reception, by a portable electronic unit (40) with which the person or the object is equipped, of first and second electromagnetic signals (a, b) respectively transmitted in respective spatially separate and partially overlapping first and second communication regions (A, B) each crossing an entry-exit zone (32) defined by the entry-exit.The first and second electromagnetic signals are transmitted substantially in phase at the same frequency and each comprises an identical message portion (100), one of said first and second electromagnetic signals further comprising an additional message portion (150) identifying the corresponding communication region (A, B), transmission of the other of said first and second electromagnetic signals being interrupted during the transmission of said additional message portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.