EP0204552A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Improvements in and relating to printed documents resistant to counterfeiting
Assignee: De la Rue International Ltd
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Filing: 1986-06-04
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Granted: —
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Expires: 2006-06-04
Abstract
Abstract A printed document includes an area for rendering difficult counterfeit reproduction via a half-tone separation technique. The area has at least one block (4) of non-parallel lines (1), whereby an interference effect or a distortion is caused in a copy of the document using the half-tone separation technique.
Inventors
- 👤 George Darmanin
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 21:02
CPC Classifications
B; B41; B41M; B41M3/00; B41M3/14; B42; B42D; B42D25/00; B42D25/30; B42D25/342; G; G06; G06K; G06K19/00; G06K19/06; G06K19/08; G06K19/10; G06K19/14; G07; G07D; G07D7/00; G07D7/003
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
49 words
A printed document including an area for rendering difficult counterfeit reproduction via a half-tone separation technique, which area comprises at least one block ( 4 ) of non-parallel lines (1), whereby an interference effect or a distortion will be caused in a copy of the document using said technique.
Claim 2
Dependent Claim
49 words
A printed document including an area for rendering difficult counterfeit reproduction via a half-tone separation technique, which area comprises at least one block ( 4 ) of non-parallel lines (1), whereby an interference effect or a distortion will be caused in a copy of the document using said technique.
Claim 3
Dependent Claim
28 words
A printed document as claimed in Claim 1 wherein said at least one block (4) comprises a set of diverging lines (1) and spaces (2) between the lines.
Claim 4
Dependent Claim
20 words
A printed document as claimed in Claim 2 wherein the widths of the lines (1) increase uniformly along their length.
Claim 5
Dependent Claim
23 words
A printed document as claimed in Claim 2 or Claim 3 wherein the widths of the spaces (2) increase uniformly along their length.
Claim 6
Dependent Claim
36 words
A printed document as claimed in any one of Claims 2 to 4 wherein the area covered by a particular line (1) is the same as the area of a space (2) adjacent said line (1).
Claim 7
Dependent Claim
31 words
A printed document as claimed in any preceding Claim wherein there is an ink coverage in the range 25% to 75% of the area of said at least one block (4).
Claim 8
Dependent Claim
26 words
A printed document as claimed in Claim 6 wherein said ink coverage is between 35% and 45% of the area of said at least one block(4).
Claim 9
Dependent Claim
25 words
A printed document as claimed in any preceding Claim wherein the maximum line density is 8 lines per millimetre at the region of minimum divergence.
Claim 10
Dependent Claim
25 words
A printed document as claimed in any preceding Claim wherein the minimum line density is 4 times per millimetre at the region of maximum divergence.
Claim 11
Dependent Claim
16 words
A printed document as claimed in any preceding Claim comprising a plurality of adjacent blocks (4).
Claim 12
Dependent Claim
30 words
A printed document as claimed in Claim 10 including blocks (4) of diverging lines collectively orientated at a multiplicity of angles between 0° and 360° relative to a datum line.
Claim 13
Dependent Claim
41 words
A printed document as claimed in Claim 11 wherein the angled blocks (4) of diverging lines include angles and dimensions expected to be used in production of half-tone separation plates for the printing of at least some of the colour constituents.
References Cited (Backward Citations)
No citation records indexed.
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