Abstract: An electronic theft-preventing system, including a first and a second multi-axis magnetometer and configured to output first and second vector signals representing movement of first and second magnetic field vectors; and a signal processor receiving the first and second vector signals, and configured to determine a multi-dimensional transformation, in accordance with optimization of a difference between the second vector signal and a compensation signal; wherein the compensation signal is generated from a transformation of the first vector signal in accordance with the multi-dimensional transformation; and generate a compensated second vector signal from the second vector signal and the first compensation signal. Determining that a detector signal meets a predefined criterion; and in response to at least the determining that the detector signal meets the predefined criterion, raising or forgo raising an alarm that warns about a possible theft-related event.

Abstract: An electronic theft-preventing system, including a first and a second multi-axis magnetometer and configured to output first and second vector signals representing movement of first and second magnetic field vectors; and a signal processor receiving the first and second vector signals, and configured to determine a multi-dimensional transformation, in accordance with optimization of a difference between the second vector signal and a compensation signal; wherein the compensation signal is generated from a transformation of the first vector signal in accordance with the multi-dimensional transformation; and generate a compensated second vector signal from the second vector signal and the first compensation signal. Determining that a detector signal meets a predefined criterion; and in response to at least the determining that the detector signal meets the predefined criterion, raising or forgo raising an alarm that warns about a possible theft-related event.

Abstract: An electronic theft-alerting system, including magnetometers, such as multiaxis magnetometers, arranged in respective stations and configured to output respective vector signals representing movement of respective magnetic field vectors; and a signal processor coupled to receive the first and second vector signals, and configured to detect a corresponding movement of a first magnetic field vector and a second magnetic field vector. Detecting commencement and continuance of fluctuation the first magnetic field vector, determining whether to raise or forgo to raise an alarm that warns about a possible theft-related event in response to the determining of commencement and continuance of fluctuation of the first magnetic field vector or the second magnetic field vector.

Abstract: An electronic theft-alerting system, including magnetometers, such as multiaxis magnetometers, arranged in respective stations and configured to output respective vector signals representing movement of respective magnetic field vectors; and a signal processor coupled to receive the first and second vector signals, and configured to detect a corresponding movement of a first magnetic field vector and a second magnetic field vector. Detecting commencement and continuance of fluctuation the first magnetic field vector, determining whether to raise or forgo to raise an alarm that warns about a possible theft-related event in response to the determining of commencement and continuance of fluctuation of the first magnetic field vector or the second magnetic field vector.

Abstract: A tag-based electronic theft-preventing system further comprises a first and second multi-axis magnetometer arranged at the two sides of an entrance to a shopping area and configured to output a first and second vector signal representing movement of a first and second magnetic field vector, respectively. A signal processor estimates a first rotation of the first magnetic field vector and a second rotation of the second magnetic field vector, and generates an indicator signal comprising indication of a counter-direction rotation or a same-direction rotation. The system computes therefrom if an unlock magnet for an anti-shoplifting tag is entering the shopping area and determines whether to warn about a possible theft-related event. Other indicators contemplated in the processing are for instance vector magnitude, continuity of detection, duration of detection, change in electric field.

Abstract: A tag-based electronic theft-preventing system further comprises a first and second multi-axis magnetometer arranged at the two sides of an entrance to a shopping area and configured to output a first and second vector signal representing movement of a first and second magnetic field vector, respectively. A signal processor estimates a first rotation of the first magnetic field vector and a second rotation of the second magnetic field vector, and generates an indicator signal comprising indication of a counter-direction rotation or a same-direction rotation. The system computes therefrom if an unlock magnet for an anti-shoplifting tag is entering the shopping area and determines whether to warn about a possible theft-related event. Other indicators contemplated in the processing are for instance vector magnitude, continuity of detection, duration of detection, change in electric field.

Abstract: The invention relates to an electronic system for anti-theft protection of goods. The system comprises: a unit for detecting a metallic material in a first detection zone; a unit for detecting a magnetic or magnetizable material in a second detection zone; and a control unit. The control unit is capable of receiving information from the units for detecting metallic and magnetic material when the one or both of these units detect(s) a metallic or a magnetic material, respectively, in the respective detection zones. The control unit is further programmable to the effect that the control unit can be programmed to emit a signal which depends on whether it receives information about the detection of metallic and/or magnetic material.

Abstract: The invention relates to a method, a device and a system for preventing false alarms in a theft-preventing system comprising a magnetic field for detecting at least one metal object in a first detection zone and means for determining a time-difference; said method comprising the steps of detecting a first change in a parameter indicative of the magnetic field in said first detection zone; detecting a second change in the parameter indicative of the magnetic field in said first detection zone; determining a time-difference between the detection of said first change in said parameter and the detection of said second change in said parameter; and performing an action based on said time-difference. In this way, false alarms due to a metal detector falsely detecting for example movement of metal-doors in a first detection zone may be reduced/eliminated. Additionally, the false alarms due to an opening and/or closing of a door with metal parts acting as an active tag may be reduced/eliminated.

Abstract: The invention relates to an electronic system for anti-theft protection of goods. The system comprises: a unit for detecting a metallic material in a first detection zone; a unit for detecting a magnetic or magnetisable material in a second detection zone; and a control unit. The control unit is capable of receiving information from the units for detecting metallic and magnetic material when the one or both of these units detect(s) a metallic or a magnetic material, respectively, in the respective detection zones. The control unit is further programmable to the effect that the control unit can be programmed to emit a signal which depends on whether it receives information about the detection of metallic and/or magnetic material.

Abstract: The invention relates to a method, a device and a system for preventing false alarms in a theft-preventing system comprising a magnetic field for detecting at least one metal object in a first detection zone and means for determining a time-difference; said method comprising the steps of detecting a first change in a parameter indicative of the magnetic field in said first detection zone; detecting a second change in the parameter indicative of the magnetic field in said first detection zone; determining a time-difference between the detection of said first change in said parameter and the detection of said second change in said parameter; and performing an action based on said time-difference. In this way, false alarms due to a metal detector falsely detecting for example movement of metal-doors in a first detection zone may be reduced/eliminated. Additionally, the false alarms due to an opening and/or closing of a door with metal parts acting as an active tag may be reduced/eliminated.