RFID transponder for a security system

• US 20040160323A1
• Filed: 02/14/2003
• Published: 08/19/2004
• Est. Priority Date: 02/03/2003
• Status: Active Grant

• Current Assignee: The ADT Security Corporation (Apollo Global Management, Inc.)
• Original Assignee: LifeShield LLC (Apollo Global Management, Inc.)
• Inventors: Stilp, Louis A.
• Granted Patent: US 7,079,034 B2
• Time in Patent Office: Days
• US Class Current: 340/572.1
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: G08B 13/2477 Antenna or antenna activator circuit
• CPC Class Codes: G08B 25/06 using power transmission lines
• CPC Class Codes: G08B 3/1083 Pager locating systems

Abstract

An RFID transponder for use in a security system based upon RFID techniques. The RFID transponder may be connected to an intrusion sensor. Example intrusion sensors are magnetically sensitive relay or LED detectors. The RFID transponder may also be connected to a passive infrared sensor. The RFID transponder can contain a battery, and the battery can be recharged by receiving and converting RF energy transmitted by the RFID reader. The security system also supports RFID transponders that may be carried by persons or animals, of that may contain a button used to signal an event such as an emergency. The RFID transponder typically uses backscatter modulation for responses, and can accept various modulation techniques for inbound wireless communications. The RFID transponder only responds when permitted.

Claims

1. An RFID transponder for use in a security system including at least a first controller and at least a first RFID reader,

wherein the said RFID transponder can receive RF energy transmitted from the said RFID reader,

wherein the said RFID transponder can interpret the received RF energy to determine whether a response is permitted,

wherein the said RFID transponder can determine whether it has a response to send to the said RFID reader, and

wherein the said RFID transponder only sends a wireless communication to the said RFID reader (a) in response to received RF energy, (b) if a response is permitted, and (c) if the said RFID transponder has any response to send.

2. The RFID transponder of claim 1, wherein the said RFID transponder is connected to an intrusion sensor.

3. The RFID transponder of claim 1, wherein the said RFID transponder is connected to a passive infrared sensor.

4. The RFID transponder of claim 1, wherein the said RFID transponder is a device wearable by a person or an animal.

5. The RFID transponder of claim 4, wherein the said RFID transponder includes a button that can be pressed to change the state of a circuit in the said RFID transponder.

6. The RFID transponder of claim 1, wherein the said RFID transponder is a master key RFID transponder associated with the said controller.

7. The RFID transponder of claim 1, wherein the said RFID transponder uses the received RF energy to accumulate a charge in an energy store contained within the said RFID transponder.

8. The RFID transponder of claim 7, wherein the said RFID transponder includes a charge pump to raise the voltage of the charge to be accumulated in the said energy store.

9. The RFID transponder of claim 7, wherein the said energy store is a capacitor.

10. The RFID transponder of claim 7, wherein the said energy store is a battery.

11. The RFID transponder of claim 10, wherein the said RFID transponder can report the state of the said battery in a response wireless communication to the said RFID reader.

12. The RFID transponder of claim 2, wherein the said intrusion sensor consists of a magnetically sensitive relay whose state can change based upon the presence or absence of a predetermined magnetic field.

13. The RFID transponder of claim 2, wherein the said intrusion sensor consists of an LED detector.

14. The RFID transponder of claim 13, wherein the said LED detector receives energy reflected from a surface.

15. The RFID transponder of claim 13, wherein the said LED detector receives energy emitted directly by an LED generator.

16. The RFID transponder of claim 15, wherein the said LED generator receives its power from a second RFID transponder.

17. The RFID transponder of claim 1, wherein the said RFID transponder uses backscatter modulation to send any said wireless communication to the said RFID reader.

18. The RFID transponder of claim 1, wherein the said RF energy is an unmodulated carrier wave.

19. The RFID transponder of claim 1, wherein the said RF energy is modulated so as to provide a wireless communications.

20. The RFID transponder of claim 1, wherein the said response indicates whether an intrusion has been detected.

21. The RFID transponder of claim 1, wherein the said response is an interrupt.