US4228348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Security document and system
Assignee: QED Intellectual Property Ltd
•
Filing: 1979-05-31
•
Granted: 1980-10-14
•
Expires: 1999-05-31
Abstract
Abstract A magnetizable anisotropic material layer having a pattern of regions of differently aligned material has an initial pattern of remanent magnetization, when manufactured by applying directional magnetic fields. This pattern is not easily restored, and is generally impossible to restore, after demagnetization or remagnetization. By preserving the residual pattern and selectively removing it in use by the application of a magnetic field, a security feature is provided. A secure document system using such a feature is provided.
Inventors
- 👤 Cyril A. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:59
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/08; G06K7/082; G06K7/083; G06K7/084; G06K19/00; G06K19/06; G06K19/08; G06K19/10; G06K19/12; G06Q; G06Q20/00; G06Q20/30; G06Q20/34; G06Q20/343; G06Q20/3433; G07; G07F; G07F7/00; G07F7/02; G07F7/08; G07F7/086; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
128 words
A secure document system comprising a secure document having a security feature of which at least a part is selectively cancellable, and apparatus for performing the cancellation, wherein in spaced first regions of said selectively cancellable part anisotropic magnetic particles are aligned and magnetised substantially solely along a preset direction and in the remaining regions of the part the particles are either not so aligned or are aligned and magnetised substantially solely along a different preset direction, and said apparatus comprises means for reading at least said part and means for cancelling a selected area, which cancelling means applies a uniaxial magnetic field to said area of such a strength and direction that the difference in remanence between said first regions and said remaining regions is significantly reduced.
Claim 2
Dependent Claim
128 words
A secure document system comprising a secure document having a security feature of which at least a part is selectively cancellable, and apparatus for performing the cancellation, wherein in spaced first regions of said selectively cancellable part anisotropic magnetic particles are aligned and magnetised substantially solely along a preset direction and in the remaining regions of the part the particles are either not so aligned or are aligned and magnetised substantially solely along a different preset direction, and said apparatus comprises means for reading at least said part and means for cancelling a selected area, which cancelling means applies a uniaxial magnetic field to said area of such a strength and direction that the difference in remanence between said first regions and said remaining regions is significantly reduced.
Claim 3
Dependent Claim
29 words
A secure document system according to claim 1 wherein the particles in the remaining regions of the part are aligned and magnetised substantially solely along a different preset direction.
Claim 4
Dependent Claim
15 words
A secure document system according to claim 2 wherein the preset directions are aligned orthogonally.
Claim 5
Dependent Claim
25 words
A secure document system according to claim 2 wherein said cancelling means is arranged to apply a magnetic field along one of the preset directions.
Claim 6
Dependent Claim
22 words
A secure document system according to claim 4 wherein the magnetic field saturates the magnetic material aligned along the one preset direction.
Claim 7
Dependent Claim
43 words
A secure document system according claim 1 wherein the apparatus includes means for reading at least the said part before and after cancellation, means for comparing said readings, and means for providing a verification signal in dependence on the correct cancellation being detected.
Claim 8
Dependent Claim
18 words
A secure document system according to claim 6 wherein the cancelling means is positioned between two reader means.
Claim 9
Dependent Claim
22 words
A secure document system according to claim 1 wherein the whole of the security feature has a detectable pattern of remanent magnetisation.
Claim 10
Dependent Claim
45 words
A secure document system according to claim 8 wherein the information represented by the detectable pattern of remanent mangetisation is detected by reader means before and after cancellation, and a verification means provides a verification signal in dependence on said detected information being the same.
Claim 11
Dependent Claim
33 words
A secure document system according to claim 1 wherein the apparatus includes means for detecting the reduction in the difference in remanace and means for producing a signal indicating that cancellation has occurred.
References Cited (Backward Citations)
US3562635A
Cited
US3627934A
Cited
GB1331604A
Cited
US3812529A
Cited
US3873975A
Cited
US3878367A
Cited
US3927393A
Cited
US3895220A
Cited
US4023204A
Cited
US3986205A
Cited
US4024379A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-14 | 1984-04-14 | 1984-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-14 | 1988-04-14 | 1988-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-14 | 1992-04-14 | 1992-10-14 | $7700.00 | Window Closed / Lapsed |