RFID systems and methods employing infrared localization

• US 7,696,881 B2
• Filed: 01/09/2009
• Issued: 04/13/2010
• Est. Priority Date: 04/26/2005
• Status: Active Grant

• Current Assignee: RF Code Incorporated
• Original Assignee: RF Code Incorporated
• Inventors: Worthy, David, Koerner, Steve
• Primary Examiner(s): TWEEL JR, JOHN ALEXANDER
• Application Number:
  US12/351,543
• Publication Number:
  US 20090115580A1
• Time in Patent Office: 459 Days
• Field of Search: 340/572.1, 340/573.1, 340/10.1, 340/10.3, 340/825.49, 235/385, 342/42
• US Class Current: 340/572.1
• CPC Class Codes: G01S 2201/01 adapted for specific applications or environments
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves

Abstract

A series of radio frequency identification (RFID) systems are delineated. An RFID system comprises an RFID signpost having a transmitter for transmitting signals of a predefined type, and a receiver for receiving signals of the predefined type, wherein the transmitter for transmitting signals of the predefined type cannot transmit until a determination is made that the predefined type of signal is not present at the receiver. Another RFID system comprises an RFID signpost including a transmitter having a continuous power dissipation rating, and a processor for controlling the transmitter such that peak pulse power of a transmission from the transmitter multiplied by its duty cycle does not exceed the continuous power dissipation rating for the transmitter.

Claims

1. A radio frequency identification (RFID) system, comprising:

an RFID signpost having a transmitter for transmitting signals of a predefined type; and

a receiver for receiving signals of the predefined type;

wherein the transmitter for transmitting signals of the predefined type cannot transmit until a determination is made that the predefined type of signal is not present at the receiver.

2. The RFID system of claim 1, wherein the predefined type of signal is selected from a signal of the group consisting of an infrared signal, an acoustic signal, a visible light signal and a radio signal.

3. The RFID system of claim 1, wherein the signal of the predefined type is used to control a device that is not part of the RFID system.

4. The RFID system of claim 3, wherein the device is a consumer product.

5. The RFID system of claim 2, wherein signal of predefined type is an infrared signal.

6. The RFID system of claim 1, wherein the transmitter ceases operation for a quiet interval when the predefined type of signal is received at the receiver.

7. The RFID system of claim 1, wherein the receiver is blinded when the transmitter is transmitting.

8. The RFID system of claim 1, further comprising a second receiver to detect a second signal of predefined type.

9. The RFID system of claim 1, wherein the transmitter is to transmit a signpost signal to a tag.

10. The RFID system of claim 9, wherein the signpost signal includes an address associated with the transmitter.

11. A radio frequency identification (RFID) device comprising:

a transmitter to transmit to a tag a signpost signal including an identification associated with the transmitter, the signpost signal to be transmitted using a transmission type; and

a receiver to detect transmissions of the transmission type, wherein the transmitter is prevented from transmitting when a transmission of the transmission type is detected by the receiver.

12. The RFID device of claim 11, wherein the transmission type is selected from the group consisting of infrared, acoustic, visible light, and radio frequency.

13. The RFID device of claim 12, wherein transmission type is infrared.

14. The RFID device of claim 11, wherein the transmission type is also to control a consumer product.

15. The RFID device of claim 11, wherein the transmitter ceases operation for a quiet interval when the transmission type is received at the receiver.

16. The RFID device of claim 11, wherein the receiver is blinded when the transmitter is transmitting.

17. The RFID device of claim 11, further comprising a second receiver to detect a second transmission type.

18. A radio frequency identification (RFID) system comprising:

a tag to receive transmissions of a transmission type; and

an RFID signpost comprising;

a transmitter to transmit to the tag a signpost signal including an identification associated with the transmitter, the signpost signal to be transmitted using the transmission type; and

a receiver to detect transmissions of the transmission type, wherein the transmitter is prevented from transmitting when a transmission of the transmission type is detected by the receiver.

19. The RFID system of claim 18, wherein the transmission type is selected from the group consisting of infrared, acoustic, visible light, and radio frequency.

20. The RFID system of claim 19, wherein transmission type is infrared.

21. The RFID system of claim 18, wherein the transmission type is also to control a consumer product.