REDUCTION OF FALSE ALARMS IN EAS SYSTEMS

• US 20170178478A1
• Filed: 12/18/2015
• Published: 06/22/2017
• Est. Priority Date: 12/18/2015
• Status: Abandoned Application

• Current Assignee: CHECKPOINT SYSTEMS, INC. (CCL Industries Incorporated)
• Original Assignee: CHECKPOINT SYSTEMS, INC. (CCL Industries Incorporated)
• Inventors: Galanti, Joseph R.
• Application Number:
  US14/974,822
• Publication Number:
  US 20170178478A1
• Time in Patent Office: Days
• CPC Class Codes: G08B 13/2431 Tag circuit details
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence

Abstract

A tag monitoring device configured to interface with a security tag adapted to be disposed on a corresponding product in a monitoring environment may include a transmitter, a receiver and processing circuitry. The transmitter transmits a periodic signal pulse during a transmit cycle. The receiver monitors for a response from the security tag after the transmit cycle. The processing circuitry is configured to control the receiver with respect to enabling the receiver to detect the response. The processing circuitry is configured to perform dynamic tuning of the receiver or transmitter.

Claims

1. A tag monitoring device configured to interface with a security tag adapted to be disposed on a corresponding product in a monitoring environment, the tag monitoring device comprising:

a transmitter configured to transmit a periodic signal pulse during a transmit cycle;

a receiver configured to monitor for a response from the security tag after the transmit cycle; and

processing circuitry configured to control the receiver to detect the response,

wherein the processing circuitry is configured to perform dynamic tuning of the receiver or transmitter by;

measuring a plurality of signal and noise levels for each of a plurality of bins of frame data associated with a first transmit port and a first receiver port, and a second transmit port and a second receiver port;

determining difference information indicative of a difference between the signal and noise levels for each of the bins;

adjusting a noise threshold of selected ones of the bins based on the difference information; and

selectively adjusting a transmitter gain based on detection of an alarm trigger condition.

2. The device of claim 1, wherein the tag monitoring device comprises a tag detection pedestal.

3. The device of claim 1, wherein the transmitter comprises a first transmitter and a second transmitter, and the receiver comprises a first receiver and a second receiver.

4. The device of claim 3, wherein selectively adjusting transmitter gain comprises:

disabling one of the first or second transmitter and enabling the other of the first or second transmitter after a predetermined time;

determining whether the alarm trigger condition is detected at a transmit or receive port associated with the one of the first or second transmitter that was disabled; and

adjusting transmitter gain in response to determining that the alarm trigger condition is detected.

5. The device of claim 4, wherein adjusting the transmitter gain comprises adjusting the transmitter gain of the one of the first or second transmitter that was disabled by a predetermined amount.

6. The device of claim 5, wherein the processing circuitry is further configured to perform dynamic tuning of the receiver or transmitter by selectively adjusting transmitter gain for the other of the first or second transmitter.

7. The device of claim 1, wherein the processing circuitry is further configured to perform dynamic tuning of the receiver or transmitter by clearing a buffer to store the signal and noise levels for each of the plurality of bins prior to the measuring.

8. The device of claim 7, wherein clearing the buffer comprises processing at least 1000 frames with no adjustments to levels of the transmitter or receiver.

9. The device of claim 8, wherein measuring the plurality of signal and noise levels for each of the plurality of bins comprises averaging a predetermined number of frames of signal and noise level data for each bin.

10. The device of claim 9, wherein the predetermined number of frames is about 2000.

11. A security system comprising:

at least one security tag disposed on a product in a monitoring environment; and

a tag monitoring device configured to interface with the at least one security tag, the tag monitoring device comprising;

a transmitter configured to transmit a periodic signal pulse during a transmit cycle;

a receiver configured to monitor for a response from the security tag after the transmit cycle; and

processing circuitry configured to control the receiver to detect the response,

wherein the processing circuitry is configured to perform dynamic tuning of the receiver or transmitter by;

measuring a plurality of signal and noise levels for each of a plurality of bins of frame data associated with a first transmit port and first receiver port, and a second transmit port and second receiver port;

determining difference information indicative of a difference between the signal and noise levels for each of the bins;

adjusting a noise threshold of selected ones of the bins based on the difference information; and

selectively adjusting transmitter gain based on detection of an alarm trigger condition.

12. The system of claim 11, wherein the tag monitoring device comprises a tag detection pedestal.

13. The system of claim 11, wherein the transmitter comprises a first transmitter and a second transmitter, and the receiver comprises a first receiver and second receiver.

14. The system of claim 13, wherein selectively adjusting transmitter gain comprises:

disabling one of the first or second transmitter and enabling the other of the first or second transmitter after a predetermined time;

determining whether the alarm trigger condition is detected at a transmit or receive port associated with the one of the first or second transmitter that was disabled; and

adjusting transmitter gain in response to determining that the alarm trigger condition is detected.

15. The system of claim 14, wherein adjusting the transmitter gain comprises adjusting the transmitter gain of the one of the first or second transmitter that was disabled by a predetermined amount.

16. The system of claim 15, wherein the processing circuitry is further configured to perform dynamic tuning of the receiver or transmitter by selectively adjusting transmitter gain for the other of the first or second transmitter.

17. The system of claim 11, wherein the processing circuitry is further configured to perform dynamic tuning of the receiver or transmitter by clearing a buffer to store the signal and noise levels for each of the plurality of bins prior to the measuring.

18. The system of claim 17, wherein clearing the buffer comprises processing at least 1000 frames with no adjustments to levels of the transmitter or receiver.

19. The system of claim 18, wherein measuring the plurality of signal and noise levels for each of the plurality of bins comprises averaging a predetermined number of frames of signal and noise level data for each bin.

20. The system of claim 19, wherein the predetermined number of frames is about 2000.