EAS Synchronization via Timing Difference Measurement
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Solution Overview
Problem
Existing electronic article surveillance (EAS) systems face challenges in synchronizing transmissions between detection and deactivation units due to differences in AC power supply wiring and internal delays, leading to false alarms and deactivations, and current synchronization methods are time-consuming, prone to human error, or costly.
Innovation Solution
A method and system that use a communication link to determine transmission timing differences between units, selecting a master synchronizing unit, and communicating a broadcast signal to synchronize transmissions by establishing delays for each unit based on determined timing differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual synchronization using phasing tools and oscilloscope is performed, then transmission synchronization can be achieved, but the process is time-consuming and susceptible to human error
Solution Approach 1:
The system performs automatic synchronization without requiring manual intervention. Each unit automatically determines its transmission timing difference relative to the master unit and adjusts its transmission delay accordingly, eliminating the need for manual phasing tools and oscilloscope operations while ensuring accurate synchronization across all units
Solution Approach 2:
The master unit broadcasts a synchronization signal in advance, and all other units measure the time difference between receiving this signal and their own transmission timing. This preliminary broadcasting of sync signals allows units to pre-calculate and adjust their transmission delays before actual operation begins
2Reliability
If manual synchronization with phasing tools is used, then transmission timing can be adjusted, but human error in reading oscilloscope and wiring differences cause improper synchronization
Solution Approach 1:
The patent replaces manual mechanical measurement tools (oscilloscope, phasing tools) with an automated electronic timing measurement system. Each unit electronically measures the time difference between the master unit's broadcast signal and its own transmission timing, eliminating human error in reading instruments and accommodating wiring differences through automatic detection and adjustment
Solution Approach 2:
The master unit serves as an intermediary that broadcasts synchronization signals to all other units. This intermediary broadcast mechanism provides a common reference point that all units can measure against, eliminating the need for direct manual comparison between units and accommodating various wiring configurations through a centralized sync protocol
3Reliability
If broadcast transmitter reference signal is used for synchronization, then transmission timing can be standardized, but reliable 24-hour reception requires complex and costly systems
Solution Approach 1:
Instead of relying on a single external broadcast transmitter, the system segments the synchronization function across multiple units. Each unit has a master unit that broadcasts sync signals locally, and all other units measure their timing difference relative to this local master. This segmentation eliminates the need for complex external broadcast receiver systems while maintaining reliable synchronization
Solution Approach 2:
The master unit acts as an intermediary that generates and broadcasts synchronization signals within the system. This internal intermediary approach replaces the need for external broadcast transmitters and complex reception systems, as the master unit's broadcast signals provide the synchronization reference for all other units without requiring expensive or complex external signal reception capabilities
4Productivity
If units transmit and receive at the same frequency without synchronization, then system operation is simple, but false detections occur resulting in false alarms and deactivations
Solution Approach 1:
The system performs preliminary synchronization by having the master unit broadcast timing reference signals before actual detection and deactivation operations begin. All units measure and record their transmission timing differences relative to the master unit and adjust their transmission delays accordingly, ensuring that all units are properly synchronized before operational use
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively synchronizes transmissions between detector and deactivator units, reducing false alarms and deactivations, and simplifies the synchronization process by minimizing human error and costs associated with complex signal reception systems.
Implementation Method 1
both detection and deactivation units may be provided. Both units typically excite an EAS tag by transmitting an electromagnetic burst at a resonance frequency of the tag. When the tag is present within the electromagnetic field created by the transmission burst, and has not been deactivated, the tag begins to resonate with an acoustomagnetic or magnetomechanical response frequency
Implementation Method 2
The deactivation units also typically transmit a deactivation signal to deactivate the EAS tag such that the EAS tag will not resonate with an acoustomagnetic, magnetomechanical or electromagnetic response frequency when the EAS tag is present in the electromagnetic field of the detection units
Data Source
AI summary
A system and method for providing synchronized transmission in an electronic article surveillance (EAS) system is provided. The method includes determining a transmission timing difference between a plurality of units of the EAS system using a communication link of the EAS system and synchronizing transmissions for each of the plurality of units based on the transmission timing difference.