Patent · US Expired

Dual mode electronic identification system

US5317309A · kind A · utility

291Cited by
22References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 21, 1992
Grant dateMay 31, 1994
Priority date
Expiry dateSep 21, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG08B3/1083
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A dual mode electronic identification system using a tag which has a RF receiver and transmitter contained therein. In the first mode the tag responds to an interrogation signal by transmitting identification data to the interrogator. In the second mode the tag periodically transmits an identification beacon signal to a directional sensing antenna which uses the signal to compute the position of the tag. The power supply for the tag operates from an internal battery or from power received from a portal signal via a tag receiving antenna. The battery can be automatically turned off when the tag is in the portal area and the unit can be shifted into the battery operated beacon mode when the tag is removed from the portal area.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.