US4591189A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Document having light-transmissive, electrically conductive authenticating interior layer
Assignee: 3M Co
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Filing: 1983-12-27
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Granted: 1986-05-27
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Expires: 2003-12-27
Abstract
Abstract A standardized document such as a credit card has a thin, light-transmissive, electrically conductive interior layer, the impedance, capacitance, or conductance of which can be sensed to indicate the authenticity of the document. When the document is cut to expose a new edge, the authenticating layer at that edge is not visible to the naked eye and hence should foil the ordinary counterfeiter.
Inventors
- 👤 Reynold E. Holmen
- 👤 Edward J. Downing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:30
CPC Classifications
B; B42; B42D; B42D25/00; B42D25/30; B42D25/36; B42D25/373; G; G07; G07F; G07F7/00; G07F7/08; G07F7/086; B42D25/20; B42D25/21; B42D25/23; B42D25/24; B42D2033/10; B42D2033/32; B42D2035/02; B42D2035/06; B42D2035/08; B42D2035/20; B42D25/309; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/24868; Y10T428/24876
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
77 words
A standardized document including an authenticating interior layer which is light-transmissive and has an area of at least 1 mm 2 , a thickness less than 20 nm, and an electrical resistivity less than 1000 ohms per square wherein the authenticating layer is sandwiched between antireflective thin film layers and, when the document is cut through the authenticating layer to expose a new edge, the authenticating layer at the edge is not visible to the naked eye.
Claim 2
Dependent Claim
77 words
A standardized document including an authenticating interior layer which is light-transmissive and has an area of at least 1 mm 2 , a thickness less than 20 nm, and an electrical resistivity less than 1000 ohms per square wherein the authenticating layer is sandwiched between antireflective thin film layers and, when the document is cut through the authenticating layer to expose a new edge, the authenticating layer at the edge is not visible to the naked eye.
Claim 3
Dependent Claim
26 words
Document as defined in claim 1 wherein the authenticating layer has a thickness less than 20 nm and a resistivity less than 1000 ohms per square.
Claim 4
Dependent Claim
23 words
Document as defined in claim 2 wherein the authenticating layer comprises silver and is sandwiched between two thin film layers of zinc sulfide.
Claim 5
Dependent Claim
25 words
Document as defined in claim 2 wherein the authenticating layer comprises gold sandwiched between two thin film layers selected from bismuth trioxide and titanium dioxide.
Claim 6
Dependent Claim
20 words
Document as defined in claim 1 wherein the authenticating layer has a transmissivity to visible light of at least 70%.
Claim 7
Dependent Claim
20 words
Document as defined in claim 1 wherein the authenticating layer has a transmissivity to visible light of at least 85%.
Claim 8
Dependent Claim
29 words
Document as defined in claim 1 wherein the authenticating layer comprises a material selected from indium-tin oxide, gold, silver, nickel, chromium, copper, platinum, tin, aluminum, stainless steel, and inconel.
Claim 9
Dependent Claim
15 words
Document as defined in claim 1 wherein said authenticating layer is coextensive with the document.
Claim 10
Dependent Claim
17 words
Document as defined in claim 1 wherein said authenticating layer is less than coextensive with the document.
Claim 11
Dependent Claim
16 words
Document as defined in claim 9 wherein said authenticating layer is only at selected discrete areas.
Claim 12
Dependent Claim
25 words
Document as defined in claim 10 wherein said authenticating layer is laterally electrically conductive and extends to at least two different edges of the document.
Claim 13
Dependent Claim
30 words
Document as defined in claim 11 wherein said authenticating layer forms a plurality of independent paths, each extending from one edge to at least one other edge of the document.
Claim 14
Dependent Claim
30 words
Document as defined in claim 12 wherein there are a plurality of electrically conductive terminals at said edges, each end of each of said paths contacting one of said terminals.
Claim 15
Dependent Claim
59 words
Document bearing visible indicia and comprising a plurality of laminae and including as an authenticating interior layer a lamina of electrically conductive material having an electrical resistivity less than 1000 ohms per square and a transmissivity to visible light of at least 70%, wherein said authenticating interior layer comprises a conductive thin film sandwiched between antireflective thin film layers.
Claim 16
Dependent Claim
59 words
Document bearing visible indicia and comprising a plurality of laminae and including as an authenticating interior layer a lamina of electrically conductive material having an electrical resistivity less than 1000 ohms per square and a transmissivity to visible light of at least 70%, wherein said authenticating interior layer comprises a conductive thin film sandwiched between antireflective thin film layers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-26 | 1989-11-25 | 1990-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-26 | 1993-11-25 | 1994-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-26 | 1997-11-25 | 1998-05-27 | $7700.00 | Window Closed / Lapsed |