EP0204574A2
Expired / Lapsed
EP
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Authenticity sensing
Assignee: De la Rue Systems Ltd
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Filing: 1986-06-05
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Granted: —
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Expires: 2006-06-05
Abstract
Abstract A method for determining whether a test sheet, such as a banknote, is a genuine reproduction of a reference sheet having a magnetic characteristic such as being printed with a ferromagnetic ink. The method comprises sensing for a magnetic effect, such as a magnetic field, with a suitable detector (14) from a plurality of areas (A-D) of the test sheet. The sensed magnetic effects are compared from two different groups (B, D) of one or more of the areas; and the test sheet is classified as unacceptable if the relationship between the magnetic effects of the compared groups is not within limits previously determined as acceptable for the relationship between the magnetic effects of the same pair of groups of areas of the reference sheet.
Inventors
- 👤 John Buttifant
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 09:15
CPC Classifications
G; G07; G07D; G07D7/00; G07D7/20; G07D7/2075; G07D7/04; G07D7/2016
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
99 words
A method of determining whether a test sheet is a genuine reproduction of a reference sheet having a magnetic characteristic, the method comprising sensing for a magnetic effect from a plurality of areas (2-4) of the test sheet; comparing the magnetic effects sensed from two different groups of one or more of the areas; and classifying the test sheet as unacceptable if the relationship between the magnetic effects of the compared groups is not within limits previously determined as acceptable for the relationship between the magnetic effects of the same pair of groups of areas of the reference sheet.
Claim 2
Independent Claim
99 words
A method of determining whether a test sheet is a genuine reproduction of a reference sheet having a magnetic characteristic, the method comprising sensing for a magnetic effect from a plurality of areas (2-4) of the test sheet; comparing the magnetic effects sensed from two different groups of one or more of the areas; and classifying the test sheet as unacceptable if the relationship between the magnetic effects of the compared groups is not within limits previously determined as acceptable for the relationship between the magnetic effects of the same pair of groups of areas of the reference sheet.
Claim 3
Dependent Claim
24 words
A method according to claim 1, further including a preliminary step of activating a magnetic material in or on the sheet to be tested.
Claim 4
Dependent Claim
32 words
A method according to claim 1 or claim 2, wherein the sensing step comprises generating a value indicating the presence of a magnetic field only if the magnetic effect exceeds a threshold.
Claim 5
Independent Claim
32 words
A method according to any of the preceding claims, wherein the magnetic effect due to an area is determined by sensing for the magnetic effect in a plurality of subsidiary areas (60).
Claim 6
Dependent Claim
38 words
A method according to claim 4, when dependent on claim 3, wherein the total magnetic effect for an area is determined by summing the number of subsidiary areas (60) where a magnetic effect exceeding the threshold is sensed.
Claim 7
Independent Claim
36 words
A method according to any of the preceding claims, wherein one of the groups comprises a single area (3) while the other comprises at least two areas (2-4) including the one area forming the one group.
Claim 8
Independent Claim
20 words
A method according to any of claims 1 to 5, wherein each group comprises a single, different area (3, 4).
Claim 9
Independent Claim
82 words
A method according to any of the preceding claims, comprising sensing magnetic effects from two pairs of different groups of one or more of the areas, determining the relationship between the magnetic effects of the groups of each pair; and classifying the test sheet as unacceptable if one or both the determined relationships is not within limits previously determined as acceptable for each of the relationships between the magnetic effects of the same pairs of groups of areas of the reference sheet.
Claim 10
Independent Claim
30 words
A method according to any one of the preceding claims, wherein the ratio of the magnetic effects of the or each pair of groups is compared with a predetermined threshold.
Claim 11
Independent Claim
190 words
A method of determining whether a test sheet is a genuine reproduction of a reference sheet having a magnetic characteristic, the method comprising (a) sensing for a magnetic effect from a plurality of areas (2-4) of the test sheet; determining the ratio between the number of areas in which a magnetic effect is sensed and the total number of the plurality of areas; and classifying the sheet as unacceptable if the determined ratio is not within limits previously determined as acceptable for the corresponding ratio for the reference sheet; (b) if the sheet is not rejected in step a, comparing the magnetic effects sensed from two different groups of one or more of the areas; and classifying the sheet as unacceptable if the relationship between the magnetic effects of the compared groups is not within limits previously determined as acceptable for the relationship between the magnetic effects of the same pair of groups of areas of the reference sheet; (c) repeating step b one or more times, if required; and classifying the sheet as acceptable only if it has not been classified as unacceptable in any of the steps a-c.
Claim 12
Independent Claim
190 words
A method of determining whether a test sheet is a genuine reproduction of a reference sheet having a magnetic characteristic, the method comprising (a) sensing for a magnetic effect from a plurality of areas (2-4) of the test sheet; determining the ratio between the number of areas in which a magnetic effect is sensed and the total number of the plurality of areas; and classifying the sheet as unacceptable if the determined ratio is not within limits previously determined as acceptable for the corresponding ratio for the reference sheet; (b) if the sheet is not rejected in step a, comparing the magnetic effects sensed from two different groups of one or more of the areas; and classifying the sheet as unacceptable if the relationship between the magnetic effects of the compared groups is not within limits previously determined as acceptable for the relationship between the magnetic effects of the same pair of groups of areas of the reference sheet; (c) repeating step b one or more times, if required; and classifying the sheet as acceptable only if it has not been classified as unacceptable in any of the steps a-c.
Claim 13
Independent Claim
58 words
A method of sorting banknotes, the method comprising feeding the banknotes in series along a feed path (12, 1'); activating a magnetic material in or on the banknote; carrying out a method according to any of the preceding claims; and causing the banknote to be fed towards a dump (54) if the note has been classified as unacceptable.
Claim 14
Dependent Claim
134 words
Apparatus for determining whether a test sheet is a genuine reproduction of a reference sheet having a magnetic characteristic, the apparatus comprising a magnetic effect detector (14); comparison means (28) for comparing the magnetic effects sensed by the sensor from two different groups of one or more areas (2-4) of the test sheet and for determining a relationship therebetween; a store for storing data representing acceptable relationships between the magnetic effects of the two corresponding groups of one or more areas of the reference sheet; and authenticating means (28) for classifying the test sheet as unacceptable if the relationship between the magnetic effects of the compared groups is not within limits previously determined as acceptable for the relationship between the magnetic effects of the same pair of groups of areas of the reference sheet.
Claim 15
Dependent Claim
134 words
Apparatus for determining whether a test sheet is a genuine reproduction of a reference sheet having a magnetic characteristic, the apparatus comprising a magnetic effect detector (14); comparison means (28) for comparing the magnetic effects sensed by the sensor from two different groups of one or more areas (2-4) of the test sheet and for determining a relationship therebetween; a store for storing data representing acceptable relationships between the magnetic effects of the two corresponding groups of one or more areas of the reference sheet; and authenticating means (28) for classifying the test sheet as unacceptable if the relationship between the magnetic effects of the compared groups is not within limits previously determined as acceptable for the relationship between the magnetic effects of the same pair of groups of areas of the reference sheet.
Claim 16
Dependent Claim
21 words
Apparatus according to claim 12, wherein the comparison means and the authenticating means are provided by a suitably programmed microcomputer (28).
Claim 17
Dependent Claim
49 words
Banknote sorting apparatus comprising apparatus according to claim 12 or claim 13; and diverting means (51) responsive to a control signal generated by the authenticating means (28) according to whether or not the banknote is classified as unacceptable to divert the banknote in one of two directions (42, 53).
References Cited (Backward Citations)
No citation records indexed.
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