Apparatus for electronic article surveillance tag pollution reduction
AssigneeSensormatic Electronics Corporation
InventorsWing Ho, Eugenio Morgado, Larry Speciale
Life of this patent
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Abstract
A magnetomechanical EAS tag having a bias magnet made of a high magnetostrictive material so that stress, which is a result of ordinary use of an article incorporating the tag, demagnetizes the bias rending the EAS tag inactive is provided. In an alternate embodiment a mechanical mechanism is incorporated with a conventional EAS tag to deactivate the tag upon ordinary use of an article to which the tag is associated. In yet another embodiment, a combination of the bias magnet made of a high magnetostrictive material and a mechanical deactivation mechanism is used to deactivate an EAS tag during ordinary use of an article to which the tag is associated.
Claims12
A deactivatable magnetomechanical electronic article surveillance marker, comprising:
- a magnetostrictive resonator adapted to mechanically resonate at a frequency within a preselected detection frequency range provided by an incident magnetic field;
- a magnetizable bias magnet disposed adjacent said resonator that, when magnetized, biases said resonator with a magnetic field having a predetermined field strength to arm said resonator to resonate at said frequency, said bias magnet being magnetostrictive and demagnetizable by stress, wherein normal use of an article incorporating the marker deactivates the marker.
A deactivatable magnetomechanical electronic article surveillance marker, comprising:
- a marker housing attachable to an article;
- a magnetostrictive resonator adapted to mechanically resonate at a frequency within a preselected detection frequency range provided by an incident magnetic field, said resonator disposed within said marker housing;
- a magnetizable bias magnet disposed adjacent said resonator that, when magnetized, biases said resonator with a magnetic field having a predetermined field strength to arm said resonator to resonate at said frequency;
- means disposed adjacent said marker housing for compressing said marker housing during ordinary usage of the article to dampen said mechanical resonance of said magnetostrictive resonator, therein deactivating the marker.
An electronic article surveillance system, comprising:
- an electronic article surveillance tag attachable to an article, said electronic article surveillance tag including:
- a magnetostrictive resonator within said tag adapted to mechanically resonate at a frequency within a preselected detection frequency range provided by an incident magnetic field;
- a magnetizable bias magnet disposed adjacent said resonator that, when magnetized, biases said resonator with a magnetic field having a predetermined field strength to arm said resonator to resonate at said frequency, said bias magnet being magnetostrictive and demagnetizable by stress, wherein normal use of an article incorporating the marker deactivates the marker;
- means for transmitting a first signal comprising said incident magnetic field, into a surveillance zone;
- and
- means for receiving a tag signal including said frequency resulting from the interaction in said surveillance zone of said first signal with said resonator in said tag for detecting the presence of said tag in said surveillance zone.
An electronic article surveillance system, comprising:
- an electronic article surveillance tag attachable to an article, said electronic article surveillance tag including:
- a marker housing;
- a magnetostrictive resonator adapted to mechanically resonate at a frequency within a preselected detection frequency range provided by an incident magnetic field, said resonator disposed within said marker housing;
- a magnetizable bias magnet disposed adjacent said resonator that, when magnetized, biases said resonator with a magnetic field having a predetermined field strength to arm said resonator to resonate at said frequency;
- means disposed adjacent said marker housing for compressing said marker housing during ordinary usage of the article to dampen said mechanical resonance of said magnetostrictive resonator;
- means for transmitting a first signal comprising said incident magnetic field, into a surveillance zone;
- and
- means for receiving a tag signal including said frequency resulting from the interaction in said surveillance zone of said first signal with said resonator in said tag for detecting the presence of said tag in said surveillance zone.
Dependencies are inferred from the claim text.