Electronic article surveillance transmitter control using target range
US6307473A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1999 |
| Grant date | Oct 23, 2001 |
| Priority date | — |
| Expiry date | Aug 24, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B13/2462
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An electronic article surveillance system responsive to the distance to a target within an interrogation zone is provided. The interrogation zone is defined by an electromagnetic field generated with a known level and transmitted by at least one antenna. A target within the interrogation zone can be any object, such as a person or shopping cart, within the interrogation zone. The target may include an EAS marker securable to an article for passage through the interrogation zone. The EAS marker is detectable at a frequency when in the electromagnetic field, and is detected by EAS detection equipment, as known in the art. The target within the interrogation zone is detected, and the distance from the antenna to the target is measured. The level of the electromagnetic field is controlled according to the distance to the target within the interrogation zone. The output level is adjusted to according to the distance to the target. The EAS system can include multiple antennas each producing an electromagnetic field that in combination define the interrogation zone. A ranging transducer is mounted near each antenna, or at opposing ends of the interrogation zone to measure the distance to …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.