Article surveillance system having target removal sensor
First Claim
1. An article surveillance marker, comprising:
- a marker body;
means for generating a first signal in response to an applied magnetic interrogation field, said first signal indicating conveyance of an article to which said surveillance marker is attached from an authorized area;
means for generating through mechanical vibration a second signal is response to an applied interrogation field, said second signal having a different frequency than said first signal, indicating unauthorized removal of the surveillance marker from the article; and
means for damping the mechanical vibration of and thereby deactivating said second signal generating means when said surveillance marker is attached to the article to be protected.
2 Assignments
0 Petitions
Accused Products
Abstract
An article surveillance marker includes a marker body having two sections connected together by a resilient hinge. A securing pin holds the body sections together in a closed position and secures the marker to an article to be protected. Two ferromagnetic ribbons are housed within separate cavities in the marker body. The first ribbon is free to mechanically vibrate and produce a first signal in response to an applied interrogation field that indicates the conveyance of the protected article from an authorized area. A contact button on the marker body damps and deactivates the second ribbon when the marker body sections are closed and the marker is secured to the article. Specifically, the contact button extends through an aperture in the marker body that communicates with the cavity containing the second marker ribbon. When the marker is closed, the button engages the second ribbon and prevents mechanical vibration and, therefore, the production of a second response signal. Conversely, when the marker is opened, the contact button disengages the second ribbon that is then free to vibrate mechanically and produce a signal indicating the unauthorized opening and removal of the marker from the article. A complete article surveillance system including a marker and two interrogation and detection circuits is also provided.
-
Citations
16 Claims
-
1. An article surveillance marker, comprising:
-
a marker body; means for generating a first signal in response to an applied magnetic interrogation field, said first signal indicating conveyance of an article to which said surveillance marker is attached from an authorized area; means for generating through mechanical vibration a second signal is response to an applied interrogation field, said second signal having a different frequency than said first signal, indicating unauthorized removal of the surveillance marker from the article; and means for damping the mechanical vibration of and thereby deactivating said second signal generating means when said surveillance marker is attached to the article to be protected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. An article surveillance system, comprising:
- a marker for attachment to an article to be protected, said marker including;
a marker body;
means for generating a first signal in response to an applied magnetic interrogation field, said first signal indicating conveyance of an article to which said surveillance marker is attached from an authorized area;
means for generating through mechanical vibration a second signal in response to an applied interrogation field, said second signal, having a different frequency than said first signal, indicating authorized removal of the surveillance marker from the article; and
means for damping the mechanical vibration of and deactivating said second signal generating means when said surveillance marker is attached to the article to be protected;first interrogating and detecting means for defining a first interrogation field zone for said protected article and for detecting said first signal as said protected article is conveyed into said first interrogation field zone from said authorized area; and second interrogating and detecting means for defining a second interrogation field zone for said protected article within said authorized area and for detecting said second signal when said marker is removed from said protected article. - View Dependent Claims (14, 15, 16)
- a marker for attachment to an article to be protected, said marker including;
Specification