RFID systems and methods employing infrared localization

• US 20060261951A1
• Filed: 04/26/2006
• Published: 11/23/2006
• Est. Priority Date: 04/26/2005
• Status: Active Grant

• Current Assignee: RF Code Incorporated
• Original Assignee: RF Code Incorporated
• Inventors: Worthy, David, Koerner, Steve
• Granted Patent: US 7,486,189 B2
• Time in Patent Office: Days
• US Class Current: 340/572.100
• 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. One such RFID system comprises an RFID signpost, and a plurality of infrared transmitters, wherein each infrared transmitter of the plurality of infrared transmitters is arranged to cover, when transmitting, a distinct sector relative to the RFID signpost. Another 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. Still 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; and

a plurality of infrared transmitters;

wherein each infrared transmitter of the plurality of infrared transmitters is arranged to cover, when transmitting, a distinct sector relative to the RFID signpost.

2. The RFID system of claim 1 further including one or more RFID tags.

3. The RFID system of claim 2 wherein each of the one or more RFID tags includes an infrared receiver.

4. The RFID system of claim 1 further including one or more additional RFID signposts, each of the one or more additional RFID signposts having a plurality of infrared transmitters wherein each infrared transmitter of the plurality of infrared transmitters is arranged to cover, when transmitting, a distinct sector relative to a respective one of the one or more additional RFID signposts.

5. The RFID system of claim 2 wherein each infrared transmitter of the plurality of infrared transmitters alters the amplitude of signal transmission in a predefined manner to enable a determination to be made as to the position of the one or more RFID tags relative to the RFID signpost.

6. The RFID system of claim 5 wherein the predefined manner comprises one of increasing or decreasing the amplitude of signal transmission sequentially.

7. 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.

8. The RFID system of claim 7 wherein the predefined type of signal comprises one an infrared signal, an acoustic signal, a visible light signal and a radio signal.

9. The RFID system of claim 7 wherein the signal of the predefined type is used to control a device that is not part of the RFID system.

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

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.

11. The RFID system of claim 10 wherein the processor controls the transmitter such that peak pulse power of the transmission from the transmitter multiplied by its duty cycle does not fall below a predefined limit.

12. The RFID system of claim 10 wherein the transmitter comprises one or more infrared light emitting diodes.