Patent CA1070731A successfully refreshed from Google Patents.
CA1070731A
Expired / Lapsed
CA
⏱️ 0.0 years remaining
Technique for circumventing document coyping
Assignee: Canadian Bank Note Co Ltd
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Filing: 1977-08-04
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Granted: 1980-01-29
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Expires: 1997-08-04
Abstract
Abstract Abstract of the Disclosure A photocopy resistant article, useful, for example, in the preparation of share certificates, bond certificates, paper money, etc. is disclosed. Two adjacent areas of the surface of the photocopy resistant article appear visually continuous to the unaided normal human eye. However, one of the areas, known as the signalling area, comprises a plurality of spaced lines having an element frequency along a notional selected line which is within the resolution capability of the photocopy machine but substantially beyond the resolution capability of the normal unaided human eye. The second of the two adjacent areas, referred to as the comparison area, comprises a plurality of spaced lines having an element frequency along a selected notional line substantially beyond the resolution capability of the unaided normal human eye and of the photocopy machine. Both areas have approximately equal area occupancy ratios and the signalling area has a density above the sensitivity threshold of the photocopy machine.
Inventors
- 👤 Robert G. Hutton
- 👤 Trevor Merry
Bibliographic Details
Application Number
—
Jurisdiction
CA
Data Source
google_patents
Last Synchronized
2026-10-26 09:28
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/08; B; B41; B41M; B41M3/00; B41M3/14; B41M3/146; G03G; G03G21/00; G03G21/04; G03G21/043
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
189 words
A patterned article resistant to accurate reproduction by photocopying using a given photocopying machine comprising: (a) a surface subdivided into two or more areas, at least two of which areas include a comparison area and a signalling area adjacent thereto; (b) said comparison area comprising a plurality of spaced lines having an element frequency along a selected notional line in a first range substantially beyond the resolution capability of the normal unaided human eye and of the photocopy machine; (c) said signalling area comprising a plurality of spaced lines having an element frequency along a selected notional line in a second range within the resolution capability of the photocopy machine but substantially beyond the resolution capability of the normal unaided human eye; (d) said comparison area and signalling area having approximately equal area occupancy ratios, the apparent macroscopic visual pattern of the surface to the normal unaided human eye in the vicinity of the signalling and comparison areas being substantially independent of the pattern formed by the border between the signalling and comparison areas; (e) said signalling area having a density above the sensitivity threshold of said photocopy machine.
Claim 2
Dependent Claim
189 words
A patterned article resistant to accurate reproduction by photocopying using a given photocopying machine comprising: (a) a surface subdivided into two or more areas, at least two of which areas include a comparison area and a signalling area adjacent thereto; (b) said comparison area comprising a plurality of spaced lines having an element frequency along a selected notional line in a first range substantially beyond the resolution capability of the normal unaided human eye and of the photocopy machine; (c) said signalling area comprising a plurality of spaced lines having an element frequency along a selected notional line in a second range within the resolution capability of the photocopy machine but substantially beyond the resolution capability of the normal unaided human eye; (d) said comparison area and signalling area having approximately equal area occupancy ratios, the apparent macroscopic visual pattern of the surface to the normal unaided human eye in the vicinity of the signalling and comparison areas being substantially independent of the pattern formed by the border between the signalling and comparison areas; (e) said signalling area having a density above the sensitivity threshold of said photocopy machine.
Claim 3
Dependent Claim
43 words
An article as in claim 1 wherein said first range is 150 to 300 lines per linear inch, said second range is 70 to 140 lines per linear inch, and said area occupancy ratio lies in the range 1:20 (0.05) to 1:1 (1.0).
Claim 4
Dependent Claim
53 words
An article as in claim 1 wherein the element frequency in the signalling area is of the order of 85 lines per linear inch, the element frequency of the comparison area is of the order of 170 lines per linear inch, and the area occupancy ratio is of the order of 1:3 (0.333).
Claim 5
Dependent Claim
53 words
An article, as recited in claim 1, wherein the lines of said comparison area and said signalling area form parts of a recognizable pattern independent of the pattern formed by the border between the signalling and comparison areas which includes at least a portion of adjacent ones of said signalling and comparison areas.
Claim 6
Dependent Claim
17 words
An article as recited in claim 1 or claim 2, wherein said surface is a flat surface.
Claim 7
Dependent Claim
17 words
An article as recited in claim 1 or claim 2, wherein said surface is a flattenable surface.
Claim 8
Dependent Claim
12 words
An article as recited in claim 1, wherein said lines are printed.
Claim 9
Dependent Claim
31 words
An article as recited in claim 1, wherein said lines are parallel lines, the parallel lines of said comparison area being substantially parallel to the parallel lines of said signalling area.
Claim 10
Dependent Claim
52 words
An article as recited in claim 8, wherein said first range is 150 to 300 parallel lines per linear inch of comparison area and said second range is from 70 to 140 parallel lines per linear inch of signalling area and said area occupancy ratio varies from 1:20 (0.05) to 1:1 (1.0).
Claim 11
Dependent Claim
16 words
An article as recited in claim 1 wherein said patterned article further comprises a disguising pattern.
Claim 12
Dependent Claim
16 words
An article as recited in claim 8 wherein said patterned article further comprises a disguising pattern.
References Cited (Backward Citations)
No citation records indexed.
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