EP0341828A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Antipilferage tags and their use
Assignee: Meto International GmbH
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Filing: 1989-04-10
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Granted: —
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Expires: 2009-04-10
Abstract
Abstract A magnetic antipilferage tag is disclosed which comprises a housing containing means for detecting an external magnetic field; a power supply; a tone generator; and an electric circuit powered by said power supply and arranged to activate said tone generator in response to an output from said magnetic field detector means.
Inventors
- 👤 Michael David Crossfield
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 06:40
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2428; G08B13/2431; G08B13/2437; G08B13/2442
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
49 words
A magnetic antipilferage tag which comprises a housing containing means for detecting an external magnetic field; a power supply; a tone generator; and an electric circuit powered by said power supply and arranged to activate said tone generator in response to an output from said magnetic field detector means.
Claim 2
Dependent Claim
49 words
A magnetic antipilferage tag which comprises a housing containing means for detecting an external magnetic field; a power supply; a tone generator; and an electric circuit powered by said power supply and arranged to activate said tone generator in response to an output from said magnetic field detector means.
Claim 3
Dependent Claim
22 words
A tag as claimed in claim 1, wherein said means for detecting an external magnetic field comprises at least one pick-up coil.
Claim 4
Dependent Claim
25 words
A tag as claimed in claim 1, wherein said means for detecting an external magnetic field comprises three pick-up coils disposed in mutually orthogonal directions.
Claim 5
Dependent Claim
31 words
A tag as claimed in claim 1, wherein said means for detecting an external magnetic field comprises a piezoelectric material surrounded about its circumference by a thin layer of magnetostrictive material.
Claim 6
Dependent Claim
18 words
A tag as claimed in claim 1,2,3 or 4, wherein said tone generator is a piezoelectric tone generator.
Claim 7
Dependent Claim
23 words
A tag as claimed in claim 1,2,3,4 or 5, wherein a resonant acoustic enclosure for said tone generator is provided in the housing.
Claim 8
Dependent Claim
18 words
A tag as claimed in any preceding claim, wherein said electric circuit is a low-power CMOS integrated circuit.
Claim 9
Dependent Claim
41 words
A tag as claimed in any preceeding claim, which further comprises attachment means whereby the tag can be attached to an article of merchandise, and which serves to activate the tone generator in the event of unauthorised removal of the tag.
Claim 10
Dependent Claim
32 words
An antipilferage system comprising a tag as claimed in any preceding claim, and an interrogating gate comprising a coil of electrically conductive material and an alternating current generator connected to said coil.
References Cited (Backward Citations)
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Cited
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