Substrate fluorescent non-overlapping dot patterns for embedding information in printed documents

摘要

The teachings as provided herein relate to a watermark embedded in an image that has the property of being relatively indecipherable under normal light, and yet decipherable under UV light. This fluorescent mark comprises a substrate containing optical brightening agents, and a first dot design printed as an image upon the substrate. The first dot design has as a characteristic the property of strongly suppressing substrate fluorescence. A second dot design having a property of providing a differing level of substrate fluorescence suppression from that of the first dot design such that when rendered in close spatial proximity with the first dot design image print, the resultant image rendered substrate suitably exposed to an ultra-violet light source, will yield a discernable image evident as a fluorescent mark.

主权项

1. A fluorescent mark indicator comprising:
a substrate containing optical brightening agents; and, an image formed on the substrate, the image formed by toggling between cells of an array, including:
first cells including a first set of dots designed to fill a first pattern and comprised of first non-overlapping primary colorants providing a relatively high area coverage, the resultant first set of dots thus having a property of high suppression of substrate fluorescence, the first dot design based on a substrate coverage being less than 50% where a fractional area coverage of the primary colorants and the substrate equal 100% and an area coverage of at least one one primary colorant is at least 10%; andsecond cells including a second dot designed to fill a pattern and comprised of second primary colorants arranged to create a relatively low area coverage while having substantially similar average color appearance as the first set of dots under normal light, the resultant second cells thus having a property of low suppression of substrate fluorescence; wherein the low area of coverage of the second cells yield a discernable pattern evident as a fluorescent mark when the substrate is suitably exposed to an ultra-violet light source.