Abstract: A device for deactivating a magnetomechanical EAS marker includes a coil and circuitry for energizing the coil to generate an alternating magnetic field. The coil is wound around a magnetic core. The core may be cruciform with four arms, on each of which a respective coil is provided. Alternatively, the core may be generally square and planar, with two coils wound around the core in different respective directions.

Abstract: A two-dimensional array of magnetomechanical markers is adhered to a continuous web. A magnetizer element is scanned across the web to magnetize the bias elements in a group of the markers with a first polarity, thereby activating the group of markers. The web is then advanced and the magnetizer is scanned across the web in an opposite direction to the previous scan, to magnetize the bias elements of a second group of the markers with a second polarity, thereby activating the second group of markers. The web is slit in a longitudinal direction to produce web-strips each carrying a column of the activated markers. The web-strips are rolled to form marker roll assemblies each having about half the bias elements magnetized with a first polarity and the remaining bias elements magnetized with an opposite polarity. The roll of activated markers forms no more than a minimal "leakage" magnetic field.

Abstract: A single deactivation device is used to deactivate both harmonic type EAS markers and magnetomechanical type EAS markers. The deactivation device includes a housing, and a permanent magnet and a coil disposed within the housing. The coil is circular and is arranged concentrically with, and outside of, the permanent magnet. The permanent magnet forms a DC magnetic field for deactivating the harmonic type marker by magnetizing control elements thereof. The coil is driven to generate an AC magnetic field that deactivates the magnetomechanical type marker by degaussing a control element thereof. The maximum amplitude of the AC magnetic field is lower than the level of the DC magnetic field, and is substantially below the coercivity of the control elements of the harmonic type marker. The coercivity of the control element of the magnetomechanical type marker is low enough to be degaussed by the AC magnetic field.

Abstract: An apparatus for use in activating and/or deactivating an EAS tag which comprises a support, a first number of one or more first discrete small magnets arranged in a first row and a second number of one or more second discrete small magnets arranged in a second row. Each first discrete small magnet is situated adjacent a second discrete small magnet and has a first region of a first magnetic polarity and a second region supported on the support of a second magnetic polarity. Each second discrete small magnet has a first region of the second magnetic polarity and a second region supported on the support and of the first magnetic polarity.

Abstract: An EAS tag or label deactivator having a central area and an edge area bordering the central area. The central area is formed from magnetic regions having alternating magnetic polarities arranged in a checkerboard pattern. The edge area is formed from a linear multipole magnet having magnetic regions of alternating polarity. The sides of the magnetic regions of the linear multipole magnetic are sized to be of lesser extent than the sides of the adjacent magnetic regions of the central area.

Abstract: A coil array for an EAS marker deactivation device is formed of three co-planar "pancake" coils energized by an a.c. drive signal and arranged to provide significant alternating magnetic fields in each of two orthogonal, horizontal directions. The coil geometry and arrangement are selected to provide smooth field distribution to minimize the possibility of harm to video and audio tapes and other magnetic medium products.

Abstract: A device for deactivating a magnetomechanical electronic article surveillance marker includes first, second, third and fourth rectangular coils arranged in a two-by-two array in a common plane. Drive circuitry energizes the coils according to an operating cycle which includes three modes. In the first mode, all four coils are driven with respective alternating currents in phase with each other. In the second mode, the first and second coils are driven in phase with each other and the third and fourth coils are driven substantially in phase with each other and substantially 180.degree. out of phase with the first and second coils. In the third mode, the first and third coils are driven in phase with each other and the second and fourth coils are driven in phase with each other and 180.degree. out of phase with the first and third coils.

Abstract: A material used to form a biasing element for a magnetomechanical EAS marker has a coercivity that is lower than the coercivity of biasing elements used in conventional magnetomechanical markers. The marker formed with the low coercivity material can be deactivated by applying an AC magnetic field at a level that is lower than is required for deactivation of conventional markers. The marker with the low coercivity bias element can also be deactivated when at a greater distance from a deactivation device than was previously practical.

Abstract: A device for deactivating a EAS marker includes a rotating support member and magnets disposed on the support member. The magnets are arranged in linear arrays, and the magnets in each array are mounted on the support member so that the upper surface of each magnet in the array has a magnetic polarity that is the opposite of the polarity of the upper surface of neighboring magnets. The support member is in the form of a thin circular platter and each array of magnets corresponds to a radius of the support member.

Abstract: An antenna arrangement in which a first antenna means is arranged to define a null contour adjacent the first antenna means and at which the magnetic flux from the first antenna means is substantially a null and in which a second antenna means is arranged to substantially follow the null contour.

Abstract: An antenna system comprises at least first and second antennas circumscribing a common center thereof at respective different distances from the common center, and circuitry for exciting the first antenna at a greater level than the second antenna, the excitation of the first and second antennas by such exciting circuitry being of respective opposite phasing. The excitation circuitry is operative to provide first fields adjacent the antenna system to a predetermined distance therefrom which are essentially controlled by the excitation of the first antenna and to provide for second fields beyond the predetermined distance which are of lesser strength than the first fields and are determined by both of the first and second antennas.

Abstract: A magnetic article surveillance system utilizing microcomputer control and unique time domain and frequency domain information gathering channels whose information is processed by the microcomputer via preselected time domain and frequency domain criteria.

Abstract: A system for use in detecting the presence of an electronic article surveillance tag in an area subject to surveillance comprises first and second antenna units disposed on opposed sides of the area, each of the antenna units incorporating therein at least first and second antennas circumscribing a common center thereof at respective different distances from the common center. Excitation circuitry is provided for exciting each first antenna at a greater level than each second antenna, the excitation of the first and second antennas by the exciting circuitry being of respective opposite phasing. The system further comprises a receiver connected to the first and second antenna units and alarm circuitry connected to the receiver to provide output indication of the presence of the tag in the area subject to surveillance.

Abstract: A magnetic article surveillance system utilizing microcomputer control and unique time domain and frequency domain information gathering channels whose information is processed by the microcomputer via preselected time domain and frequency domain criteria.

Abstract: Surveillance of magnetically tagged articles in a control zone is effected in a noisy environment by so shielding an antenna establishing a front magnetic field in the control zone as to reduce field strength in the back field rearwardly of the control zone. Shield magnetic material has response to the field which is detectably distinct from tag material response to the field.