US5455563A
Expired / Lapsed
US
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Magnetic marker and method for modifying the magnetic properties thereof
Assignee: Meto International GmbH
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Filing: 1991-10-14
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Granted: 1995-10-03
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Expires: 2011-10-14
Abstract
Abstract A method of modifying the magnetic properties of a thin film of a magnetically active material is provided which comprises forming surface modulations on the material in order to partition it into regions which display at least some degree of mutual magnetic independence. The resulting modified thin film may be used as a marker or tag in an anti-pilferage or article location system. The surface modulations formed on the material in the anti-pilferage or article location marker serve to enhance the response of the marker when used in an anti-pilferage or article location system.
Inventors
- 👤 Dafydd G. Davies
- 👤 Stephen H. Chambers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:57
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2405; G08B13/2408; G08B13/2428; G08B13/2434; G08B13/2437; G08B13/244; G08B13/2442; H; H01; H01F; H01F41/00; H01F41/32; H01F41/34; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
78 words
A method of enhancing a signal generated by the excitation of a thin film of a magnetically active material exposed to a high frequency fluctuating magnetic field, which comprises forming surface modulations on said material for (a) partitioning the material into regions having mutual magnetic independence; (b) changing the effective magnetic permeability of the material without substantially effecting its total saturation magnetization, and (c) reducing the coercive force of the material required for high-frequency excitation of said material.
Claim 2
Independent Claim
78 words
A method of enhancing a signal generated by the excitation of a thin film of a magnetically active material exposed to a high frequency fluctuating magnetic field, which comprises forming surface modulations on said material for (a) partitioning the material into regions having mutual magnetic independence; (b) changing the effective magnetic permeability of the material without substantially effecting its total saturation magnetization, and (c) reducing the coercive force of the material required for high-frequency excitation of said material.
Claim 3
Dependent Claim
16 words
A method according to claim 1, wherein said material is a high-permeability, low-coercivity magnetically active material.
Claim 4
Dependent Claim
19 words
A method according to claim 1, wherein said thin film of magnetically active material is supported on a substrate.
Claim 5
Dependent Claim
23 words
A method according to claim 1, wherein said surface modulations are formed by a technique involving the removal of material from the film.
Claim 6
Dependent Claim
24 words
A method according to claim 4, wherein said technique comprises the application of a blade or sharpened point to the surface of said material.
Claim 7
Dependent Claim
16 words
A method according to claim 4, wherein said technique comprises removal of material by chemical means.
Claim 8
Dependent Claim
15 words
A method according to claim 4, wherein said technique comprises cutting, scribing, perforation or scratching.
Claim 9
Dependent Claim
17 words
A method according to claim 4, wherein less than 25% of said magnetically active material is removed.
Claim 10
Dependent Claim
17 words
A method according to claim 8, wherein less than 5% of said magnetically active material is removed.
Claim 11
Dependent Claim
17 words
A method according to claim 9, wherein less than 1% of said magnetically active material is removed.
Claim 12
Dependent Claim
21 words
A method according to claim 10, wherein more than 0.1% and less than 1% of said magnetically active material is removed.
Claim 13
Dependent Claim
24 words
A method according to claim 1, wherein said surface modulations are formed by a technique which does not remove material from the thin film.
Claim 14
Dependent Claim
18 words
A method according to claim 12, wherein said technique causes localised plastic deformation of the magnetically active material.
Claim 15
Dependent Claim
17 words
A method according to claim 13, wherein said technique comprises stamping, cracking or folding the thin film.
Claim 16
Dependent Claim
19 words
A method according to claim 1, wherein said surface modulations are formed by means of impregnation or localised heating.
Claim 17
Dependent Claim
36 words
A method according to claim 15, wherein said surface modulations are formed by applying focused electromagnetic radiation, laser radiation, ion beams, beam of neutral particles, jets of solid particles or jets of liquids to said material.
Claim 18
Dependent Claim
26 words
A method according to claim 1, wherein said surface modulations are formed by means of localised application of further quantities of said material onto said film.
Claim 19
Dependent Claim
34 words
A method according to claim 1, wherein said modulations are formed by means of localized application of a further material onto said film, which further material is magnetically different from said magnetically active material.
Claim 20
Dependent Claim
87 words
A marker or tag for use in an anti-pilferage or article location system, comprising a magnetically active material consisting of a thin film of a single material supported on a substrate, said thin film of magnetically active material having surface modulation means for: (a) partitioning said material into regions having mutual magnetic independence; (b) changing the effective magnetic permeability of the material with substantially no effect on its total saturation magnetization; and (c) reducing the coercive force of the material required for high-frequency excitation of said material.
Claim 21
Dependent Claim
87 words
A marker or tag for use in an anti-pilferage or article location system, comprising a magnetically active material consisting of a thin film of a single material supported on a substrate, said thin film of magnetically active material having surface modulation means for: (a) partitioning said material into regions having mutual magnetic independence; (b) changing the effective magnetic permeability of the material with substantially no effect on its total saturation magnetization; and (c) reducing the coercive force of the material required for high-frequency excitation of said material.
Claim 22
Dependent Claim
21 words
An anti-pilferage or article location marker as claimed in claim 19, wherein said surface modulation means includes perforations or security cuts.
References Cited (Backward Citations)
GB1253115A
Cited
US4484184A
Cited
US4682154A
Cited
US4710754A
Cited
EP0295085A1
Cited
US4940966A
Cited
US4960651A
Cited
US4829288A
Cited
US4884063A
Cited
US4857891A
Cited
US4967185A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-02 | 1999-04-03 | 1999-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-02 | 2003-04-03 | 2003-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-02 | 2007-04-03 | 2007-10-03 | $7700.00 | Window Closed / Lapsed |