Patent US4977040A successfully refreshed from Google Patents.
US4977040A
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US
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Magnetic card
Assignee: NTT Inc
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Filing: 1988-06-29
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Granted: 1990-12-11
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Expires: 2008-06-29
Abstract
Abstract In the subject magnetic card, first magnetic recording layer 2 is laid over substrate 1. First magnetic recording layer 2 has a coercive force that enables magnetic recording of data. Second magnetic recording layer 4, having a coercive force smaller than that of first magnetic recording layer 2, is laid over first magnetic recording layer 2, with shielding intermediate layer 3 interposed therebetween. Magnetic shielding layer 5 is provided as an uppermost magnetic layer.
Inventors
- 👤 Norio Yano
- 👤 Ginya Ishiguro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:58
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/74; G11B5/80; G06; G06K; G06K19/00; G06K19/06; G06K19/08; G06K19/10; G06K19/12; G06K19/06187; G06K19/06196; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
102 words
A magnetic card for storing selected information, comprising: a substrate; a plurality of stacked magnetic recording layers provided on the substrate, each of the magnetic recording layers having a coercive force that enables magnetic recording and in which a portion of the selected information is stored in accordance with a predetermined relationship such that said respective portions stored in the plurality of magnetic recording layers are combinable to reproduce said selected information; and a magnetic shielding layer provided at least on the uppermost magnetic recording layer, the shielding magnetic layer having such a small coercive force as is unsuitable for magnetic recording.
Claim 2
Dependent Claim
102 words
A magnetic card for storing selected information, comprising: a substrate; a plurality of stacked magnetic recording layers provided on the substrate, each of the magnetic recording layers having a coercive force that enables magnetic recording and in which a portion of the selected information is stored in accordance with a predetermined relationship such that said respective portions stored in the plurality of magnetic recording layers are combinable to reproduce said selected information; and a magnetic shielding layer provided at least on the uppermost magnetic recording layer, the shielding magnetic layer having such a small coercive force as is unsuitable for magnetic recording.
Claim 3
Dependent Claim
79 words
A magnetic card according to claim 1, wherein the plurality of magnetic recording layers and the magnetic shielding layer comprise a first magnetic recording layer stacked on the substrate; an intermediate magnetic shielding layer stacked on the first magnetic recording layer; a second magnetic recording layer stacked on the intermediate magnetic shielding layer and having a smaller coercive force than that of the first magnetic recording layer; and a magnetic shielding layer stacked on the second magnetic recording layer.
Claim 4
Dependent Claim
67 words
A magnetic card according to claim 1, wherein the plurality of magnetic recording layers and the magnetic shielding layer comprise a first magnetic recording layer stacked on the substrate; a second magnetic recording layer stacked of the first magnetic recording layer and having a smaller coercive force than that of the first magnetic recording layer; and a magnetic shielding layer stacked on the second magnetic recording layer.
Claim 5
Dependent Claim
43 words
A magnetic card according to claim 2, wherein the second magnetic recording layer is formed in a stripe pattern, and the magnetic shielding layer is provided such that it covers part of the intermediate magnetic shielding layer and the second magnetic recording layer.
Claim 6
Dependent Claim
43 words
A magnetic card according to claim 3, wherein the second magnetic recording layer is formed in a stripe pattern, and the magnetic shielding layer is provided such that it covers part of the first magnetic recording layer and the second magnetic recording layer.
Claim 7
Dependent Claim
53 words
A magnetic card according to claim 2, 3, 4 or 5, wherein the first and second magnetic recording layers store said selected information divided into portions, one portion Ao being recorded on the first layer and the other portion Bo being recorded on the second layer, in accordance with a predetermined relationship Co.
Claim 8
Dependent Claim
34 words
A magnetic card according to claim 1, 2, 3, 4 or 5, wherein the first magnetic recording layer contains magnetic particles, of one of Ba ferrite and cobalt absorbed γ-Fe 2 O 3 .
Claim 9
Dependent Claim
17 words
A magnetic card according to claim 7, wherein said magnetic particles are γ-Fe 2 O 3 .
Claim 10
Dependent Claim
39 words
A magnetic card according to claim 1, 2, 3, 4 or 5, wherein the magnetic shielding layer contains magnetic particles of one material selected from the group consisting of a magnetic alloy containing Al, Si and Fe, and MnZn.ferrite.
Claim 11
Dependent Claim
22 words
A magnetic card according to claim 1, 2, 3, or 5, wherein the magnetic shielding layer is covered with a protection layer.
Claim 12
Dependent Claim
75 words
A magnetic card- according to claim 6, wherein the first magnetic recording layer contains magnetic particles of one material selected from the group consisting of Ba ferrite and cobalt absorbed γ-Fe 2 O 3 , the second magnetic recording layer contains magnetic particles of γ-Fe 2 O 3 and, the magnetic shielding layer contains magnetic particles of one material selected from the group consisting of a magnetic alloy containing Al, Si and Fe, and MnZn.ferrite.
Claim 13
Dependent Claim
18 words
A magnetic card according to claim 11, wherein the magnetic shielding layer is covered with a protection layer.
Claim 14
Independent Claim
111 words
A method for producing a magnetic card storing selected information, comprising the steps of: providing a substrate; placing a plurality of stacked magnetic recording layers on the substrate, each of the magnetic recording layers having a coercive force that enable magnetic recording; storing a portion of the selected information in said plurality of recording layers in accordance with a predetermined relationship such that said respective portions stored in the plurality of magnetic recording layers are combinable to reproduce said selected information; and providing a magnetic shielding layer at least on the uppermost magnetic recording layer, the shielding magnetic layer having such a small coercive force as is unsuitable for magnetic recording.
Claim 15
Independent Claim
111 words
A method for producing a magnetic card storing selected information, comprising the steps of: providing a substrate; placing a plurality of stacked magnetic recording layers on the substrate, each of the magnetic recording layers having a coercive force that enable magnetic recording; storing a portion of the selected information in said plurality of recording layers in accordance with a predetermined relationship such that said respective portions stored in the plurality of magnetic recording layers are combinable to reproduce said selected information; and providing a magnetic shielding layer at least on the uppermost magnetic recording layer, the shielding magnetic layer having such a small coercive force as is unsuitable for magnetic recording.
References Cited (Backward Citations)
US2643130A
Cited
US3256483A
Cited
US3219353A
Cited
US3808404A
Cited
JPS51129209A
Cited
JPS5389000A
Cited
JPS5593514A
Cited
US4410583A
Cited
US4555444A
Cited
US4544574A
Cited
US4624883A
Cited
US4624894A
Cited
JPS60219635A
Cited
JPS60219636A
Cited
US4687231A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-10 | 1994-06-11 | 1994-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-10 | 1998-06-11 | 1998-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-10 | 2002-06-11 | 2002-12-11 | $7700.00 | Window Closed / Lapsed |