RFID detection system
First Claim
Patent Images
1. A system for monitoring the position of at least one RFID tag, said system comprising:
- at least one RFID tag;
at least one detector incorporating means for receiving signals from said RFID tag for detecting changes in the range of said RFID tag from said detector; and
control means for comparing signals sequentially received from said RFID to detect a change in range of said RFID tag, and for triggering an alarm if said detected change in range of said RFID tag exceeds a predetermined threshold.
1 Assignment
0 Petitions
Accused Products
Abstract
A system 100 is disclosed for monitoring the position of one or more RFID tags 201. The system has a detector 301 incorporating circuitry 304 for detecting changes in the range of an RFID tag 201 from the detector and for triggering an alarm 401 if a detected change in range of an RFID tag 201 exceeds a predetermined threshold or if the RFID radio tag cannot be detected by the detector 301. Range may be detected, for example, by measuring the time of a returned radio signal from a tag 201, by measuring the strength of a returned radio signal from a tag, or by detecting changes in a periodic interval at which energy is transmitted by a tag.
-
Citations
15 Claims
-
1. A system for monitoring the position of at least one RFID tag, said system comprising:
-
at least one RFID tag;
at least one detector incorporating means for receiving signals from said RFID tag for detecting changes in the range of said RFID tag from said detector; and
control means for comparing signals sequentially received from said RFID to detect a change in range of said RFID tag, and for triggering an alarm if said detected change in range of said RFID tag exceeds a predetermined threshold. - View Dependent Claims (2, 3)
-
-
4. A system for monitoring the position of at least one RFID tag, said system comprising:
-
at least one RFID tag;
at least one detector incorporating means for receiving signals from said RFID tag for detecting changes in the range of said RFID tag from said detector;
control means comparing the signals received from said RFID tag at different times to detect a change in range of said RFID tag, and triggering an alarm if a detected change in range of said RFID tag exceeds a predetermined threshold; and
said RFID tag including circuitry having means for emitting short bursts of RF energy at periodic intervals. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A system for monitoring the position of an RFID tag, comprising:
-
a transmitter for transmitting RF energy;
an RFID tag including circuitry having means for receiving said RF energy and transmitting short bursts of RF energy at periodic intervals based on the relative position and orientation of said RFID tag relative to said transmitter;
a detector for receiving said bursts transmitted from said RFID tag; and
a controller interconnected to said detector for determining a change in range of said RFID tag and triggering an alarm if said change in range of said RFID tag exceeds a predetermined threshold.
-
-
15. A method for monitoring the position of an RFID tag, comprising:
-
transmitting RF energy to said RFID tag;
receiving said RF energy in said RFID tag;
using said RF energy for transmitting short bursts of RF energy from said RFID tag at periodic intervals;
detecting said short bursts and determining a change in range of said RFID tag; and
triggering an alarm if said change in range exceeds a predetermined threshold.
-
Specification