Method and system for localizing objects using passive RFID tags which identifies the RFID with an LED

1. A method for localizing an object in a stack of objects, said method comprising determining a location of the object being localized, wherein a radio frequency identification (RFID) tag is attached to each object, wherein each RFID tag is a passive RFID tag that comprises a unique identifier of the object to which each RFID tag is attached and further comprises a respective light emitting diode (LED) and a chip configured to control the LED, wherein a RFID reader comprises a plurality of antennas, wherein each antenna is positioned differently and configured to transmit a read signal comprising a read command that can be detected by only a different plurality of RFID tags attached to the objects in the stack of objects within a reading range of the transmitted signal from each antenna, and wherein said determining the location of the object comprises:

said RFID reader selecting an antenna of the plurality of antennas, said selected antenna not previously selected by the RFID reader;

said RFID reader powering the selected antenna;

said RFID reader transmitting, via the selected and powered antenna, the read signal comprising the read command to the stack, wherein the read signal comprises an identifier of one object in the stack, and wherein the one object is the object being localized in the stack;

after said transmitting, said RFID reader waiting for a first specified period of time for a response to the read signal from a responsive RFID tag that detected the read signal and determined that the identifier of the one object in the read signal matches the unique identifier in the responsive RFID tag comprised by the one object;

if said RFID reader receives the response during the first specified period of time via the selected and powered antenna, then said RFID reader powering the selected antenna for a second specified period of time which triggers the selected and powered antenna to transmit another read signal to the responsive RFID tag to cause the responsive RFID tag to light its respective LED during the second specified period of time for a duration sufficient for a user to see the lighted LED during the second specified period of time, wherein the second specified period of time immediately follows the first specified period of time;

if said RFID reader does not receive the response during the first specified period of time, then said RFID reader stop powering the selected antenna, deselecting the selected antenna, and repeating said selecting, said powering, said transmitting, and said waiting for another antenna of the plurality of antennas until the selected antenna results in said RFID reader receiving the response during the first specified period of time,

wherein said RFID reader receives the response during the first specified period of time for one selected antenna of the selected antennas.

2. The method of claim 1 , wherein the one selected antenna is selected during a first performance of said selecting.

3. The method of claim 1 , wherein the one selected antenna is not selected during a first performance of said selecting, and wherein the one selected antenna is selected during a performance of said selecting subsequent to the first performance of said selecting.

4. The method of claim 1 , said determining the location of the object further comprising determining that the response received from the responsive RFID tag is greater than any response received by the RFID reader from any other RFID tag attached to an object in the stack.

5. The method of claim 1 , wherein the different plurality of RFID tags in the reading range of each antenna of the plurality of antennas does not include any RFID tag in the reading range of any other antenna of the plurality of antennas.

6. The method of claim 1 , wherein the different plurality of RFID tags in the reading range of a first antenna of the plurality of antennas includes a RFID tag in the reading range of a second antenna of the plurality of antennas.

7. The method of claim 1 , wherein each object in the stack is a compact disc, wherein the compacts discs in the stack are oriented parallel to one another, and wherein the LEDs comprised by the respective RFID tags attached to the objects in the stack are aligned parallel to one another and are simultaneously visible to a user.

8. A system for localizing an object in a stack of objects, said system comprising a RFID reader, wherein a radio frequency identification (RFID) tag is attached to each object, wherein each RFID tag is a passive RFID tag that comprises a unique identifier of the object to which each RFID tag is attached and further comprises a respective light emitting diode (LED) and a chip configured to control the LED, wherein the RFID reader comprises a plurality of antennas, wherein each antenna is positioned differently and configured to transmit a read signal comprising a read command that can be detected by only a different plurality of RFID tags attached to the objects in the stack of objects within a reading range of the transmitted signal from each antenna, wherein the RFID reader is configured to implement a method comprising determining a location of the object being localized, and wherein said determining the location of the object comprises:

said RFID reader selecting an antenna of the plurality of antennas, said selected antenna not previously selected by the RFID reader;

said RFID reader powering the selected antenna;

said RFID reader transmitting, via the selected and powered antenna, the read signal comprising the read command to the stack, wherein the read signal comprises an identifier of one object in the stack, and wherein the one object is the object being localized in the stack;

after said transmitting, said RFID reader waiting for a first specified period of time for a response to the read signal from a responsive RFID tag that detected the read signal and determined that the identifier of the one object in the read signal matches the unique identifier in the responsive RFID tag comprised by the one object;

if said RFID reader receives the response during the first specified period of time via the selected and powered antenna, then said RFID reader powering the selected antenna for a second specified period of time which triggers the selected and powered antenna to transmit another read signal to the responsive RFID tag to cause the responsive RFID tag to light its respective LED during the second specified period of time for a duration sufficient for a user to see the lighted LED during the second specified period of time, wherein the second specified period of time immediately follows the first specified period of time;

if said RFID reader does not receive the response during the first specified period of time, then said RFID reader stop powering the selected antenna, deselecting the selected antenna, and repeating said selecting, said powering, said transmitting, and said waiting for another antenna of the plurality of antennas until the selected antenna results in said RFID reader receiving the response during the first specified period of time,

wherein said RFID reader receives the response during the first specified period of time for one selected antenna of the selected antennas.

9. The system of claim 8 , wherein the one selected antenna is selected during a first performance of said selecting.

10. The system of claim 8 , wherein the one selected antenna is not selected during a first performance of said selecting, and wherein the one selected antenna is selected during a performance of said selecting subsequent to the first performance of said selecting.

11. The system of claim 8 , said determining the location of the object further comprising determining that the response received from the responsive RFID tag is greater than any response received by the RFID reader from any other RFID tag attached to an object in the stack.

12. The system of claim 8 , wherein the different plurality of RFID tags in the reading range of each antenna of the plurality of antennas does not include any RFID tag in the reading range of any other antenna of the plurality of antennas.

13. The system of claim 8 , wherein the different plurality of RFID tags in the reading range of a first antenna of the plurality of antennas includes a RFID tag in the reading range of a second antenna of the plurality of antennas.

14. The system of claim 8 , wherein each object in the stack is a compact disc, wherein the compacts discs in the stack are oriented parallel to one another, and wherein the LEDs comprised by the respective RFID tags attached to the objects in the stack are aligned parallel to one another and are simultaneously visible to a user.