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US5889271A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of reading a security thread

Assignee: Bank of England
•
Filing: 1995-11-07
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Granted: 1999-03-30
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Expires: 2015-11-07
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Abstract

Abstract A security thread detector assembly for reading a security thread carried by a security document and coded such that each of a succession of segments along the thread represents a digital value, the particular digital value being represented by the particular characteristic of the respective segment comprises a head having a multiplicity of parallel reading channels having a track pitch which is substantially less than the length of a segment and being disposed to read the document such that the thread is substantially broadside to the channels, whereby all the segments are sensed substantially simultaneously and each segment is represented by a plurality of samples.

Inventors

  • 👤 Martin John Webb

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 05:36
CPC Classifications
G; G07; G07D; G07D7/00; G06; G06K; G06K7/00; G06K7/08; G06K7/082; G06K7/083; G06K7/084; G07D7/004

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 158 words
A method of reading a security thread carried by a security document and coded such that each of a succession of segments along the thread represents a digital value, each digital value being represented by the characteristic of the segment, the method comprising the steps of providing a multiplicity of side-by-side reading channels having a track pitch which is substantially less than the length of a segment, presenting the document such that the thread is substantially broadside to the channels so that all of the segments which are to be sensed are sensed substantially simultaneously, representing each sensed segment by a plurality of samples, applying to at least one group of samples a numerical criterion of tolerances such that any segment may be validly represented by more than or fewer than a nominal number of samples, the nominal number corresponding to said plurality of samples and being at least four, and detecting a code represented by the segments.
Claim 2
Independent Claim 158 words
A method of reading a security thread carried by a security document and coded such that each of a succession of segments along the thread represents a digital value, each digital value being represented by the characteristic of the segment, the method comprising the steps of providing a multiplicity of side-by-side reading channels having a track pitch which is substantially less than the length of a segment, presenting the document such that the thread is substantially broadside to the channels so that all of the segments which are to be sensed are sensed substantially simultaneously, representing each sensed segment by a plurality of samples, applying to at least one group of samples a numerical criterion of tolerances such that any segment may be validly represented by more than or fewer than a nominal number of samples, the nominal number corresponding to said plurality of samples and being at least four, and detecting a code represented by the segments.
Claim 3
Dependent Claim 34 words
A method according to claim 1 wherein the document is rectangular and the thread is parallel to shorter sides of the document, and including presenting the document with one of the shorter sides leading.
Claim 4
Dependent Claim 16 words
A method according to claim 1 wherein the group of samples represents a multiplicity of segments.
Claim 5
Dependent Claim 29 words
A method according to claim 1 wherein the samples of a plurality of groups are examined and the digits representing the same binary value within a group are counted.

References Cited (Backward Citations)

US3978450A Cited
GB2098768A Cited
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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) 2002-03-29 2002-09-28 2003-03-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-03-29 2006-09-28 2007-03-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-03-29 2010-09-28 2011-03-30 $7700.00 Window Closed / Lapsed

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