Counterfeit protected document

A method and product, resulting from application of the method, for making images on a document that will not be replicated properly by electro-optical scanning and copying devices. Documents that cannot be replicated by known copying machines or other replicating devices are produced according to the invention method, as well as alternative methods. All of the methods disclosed herein are instructive for making the images and art work on such documents by forming lines into various patterns in a manner imitative of intaglio or gravure printing. The pitch of the lineations is deliberately selected so as to vary minutely from the pitch of the scanning trace of various copying machines such as photocopiers, video opticons, and the like. The variation in pitch may be obtained by deliberately manufacturing the document with the desired pitch or, subsequent to the image placement therein, altering the dimensions or geometry of the document so as to effectively skew the pitch parameter.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to bogus or counterfeit document detection 
methods and, particularly to the method for printing or otherwise making a 
product document that will be nonreplicable by any scanning-type copying 
device such as a copying machine, video opticon, and the like. 
2. Discussion of the Prior Art 
Many methods have been employed, as well as myriad machines, in order to 
verify the authenticity of documents such as bank notes, checks, licenses 
and identification pictures. Currency, security and other valuable 
documents are, in most cases, printed or lithographed onto high quality 
media such as silk, rice paper or high content rag paper. The printing may 
be black and white or color and most often employs one of two printing 
processes--line intaglio or gravure (rotogravure). The first, intaglio, is 
a process widely used in the production of bank notes, securities, stamps 
and engraved documents. The distinctive sharpness of fine lines and 
readily discernable differences in ink thickness that the process produces 
make it a preferred technique for production of bank notes and securities. 
The gravure pattern is similar to that of intaglio with the exception 
being that rather than fine channels appearing between lines, the gravure 
etching consists of extremely small square - like cells laid out in a grid 
array. In both of these methods of printing, the ink is held within the 
line troughs or square wells and transferred to the print media, under 
high mechanical pressures, by capillary movement. The gravure printing 
process is generally used for catalogs, magazines, newspaper supplements, 
cartoons, floor and wall coverings, textiles and plastics. 
Other methods such as the Dultgen half tone intaglio process and the 
Henderson process (often referred to as direct transfer or inverse half 
tone gravure) are often used in place of the gravure but do not 
distinguish significantly over the previously described processes relative 
to the grid-like orientation of lines and dots (formed when the 
square-type wells are used). Since the purpose of the instant invention is 
to provide methods and a product made from such methods for preventing 
replication of any important document, in black and white or color, the 
remaining portion of this disclosure shall concentrate more heavily on 
intaglio printed surfaces rather than gravure or its variations. Further, 
most discussion will be confined to intaglio because a general disclosure 
relating to line printing would necessarily include dot printing as well 
since, by the inventor's definition, a dot is merely a line of short 
length, its length being equivalent to its width. Thus, the square-type 
well or dot of the gravure printing process may be likened to the intaglio 
wherein two sets of parallel lines or lineations, one orthognal to the 
other, are employed. 
After an intense, exhaustive search of the literature and patents on file 
at the United States Patent and Trademark Office, the instant inventor 
turned from the more current methods and machines for document 
verification and devised the instant invention product and the methodology 
for its preparation. The philisophical motivation for the instant 
invention is twofold: first, in order to determine whether a document is 
counterfeit, it is not necessary to determine its authenticity--one only 
has to prove that a single element of the document is bogus; and second, a 
labored examination in order to determine a singular bogus element would 
be conducted best if the document were to contain within itself the means 
that would prevent its replication. In order to achieve these two 
objectives, it was necessary for the instant inventor to blend his skill 
in printing with the knowledge of optics that is readily available to one 
of ordinary skill. Accordingly, and being long familiar with the 
phenomenon of moire that often occurs in printing, he reasoned that what 
had always occured as a problem could be turned to the advantage of 
society in the elimination of the counterfeiting of face - value 
documents. For the edification of the reader it will suffice to say that 
the moire is a serious problem in color reproduction. It is the occurance 
of an interference pattern caused by the over printing of the screens in 
colorplates (similar effects can be observed by superimposing two pieces 
of a fine grid network such as window screening). Indeed, the technique of 
rotating half tone screens, when making the negatives for a printing 
plate, has been developed in order to avoid the moire interference. Often 
it appears as the geometrical design that results when a set of straight 
or curved lines is superposed onto another set. If a grating design, made 
of parallel black and white bars of equal width, is superposed on an 
identical grating, moire fringes will appear as the crossing angle is 
varied from about one second of arc to about 45 degrees. The pattern will 
consist of equispaced parallel fringes; but, if two gratings of slightly 
different spacing are superposed, fringes will appear (known as "beat" 
fringes) which shift positions much faster than does the displacment of 
one grating with respect to the other. Finally, it has been noted that a 
different kind of moire pattern results when two families of curves of 
different colors are superposed--fringes of a third color are produced. An 
application of the use of the moire phenomenon is disclosed in U.S. Pat. 
No. 3,109,239, issued to the instant inventor and titled SCREEN ANGLE 
INDICATOR. This disclosure reveals a method that is used to locate, view 
and visually align the angle of half tone screens without the aid of 
magnification. The screen half tone which is to be read is placed over a 
screened 360 degree or 90 degree protractor which contains five half tone 
screens of about 60% in value 21/2 degrees to the right and 21/2 degrees 
to the left at angles of 45 degrees, 60 degrees, 75 degrees, 90 degrees 
and 105 degrees. When the screen is turned within 5 degrees of a 
predetermined angle, a moire interference pattern begins to visually form 
and, as the screen comes closer, a much darker and larger moire pattern 
becomes visible. When the screen reaches the exact angle to be located, 
the moire pattern appears greatly englarged and, in fact, turns either 
black or white. Any misalignment appears as an enlarged moire or secondary 
pattern; thus the screen angle indicator creates magnified images by 
interference in order to identify and locate or position a half tone 
screen at a given angle. It became apparent to the instant inventor, 
therefore, that the moire pattern, rather than as an indicator which is 
gradually removed from an image, may also be used as an indicator of some 
perhaps latent defect in a document. More appropriately, there had to be 
some way in which a pattern could be included in an image by printing it 
in a selected pattern. Then, when the image was viewed through a 
superposed grid, such as previously discussed, a moire pattern would be 
observed according to the degree in which the patterns interferred with 
each other. Moreover, if one were to reduce the moire apparatus to its 
simplest form, that is, such as viewing some background through the common 
parallel-stake snow fence (suggested by the previous description of 
parallel black grid lines spaced by parallel white or clear areas of equal 
width), and if the pattern over which it is superposed is formed of lines 
and dots that are equally spaced from each other (whether parallel or 
curvilinear), but a fraction off the pitch (or spacing) of the overlain 
grid, the observer would be deprived of a high percentage of the 
background field of vision. Thus, the background image, if formed of the 
line and dot printed grid, would be rendered nonreplicable to any 
apparatus being used to record the view. It is this particular aspect of 
moire pattern creation that is used by the instant inventor to create this 
invention. Further, he also recognized that because the modern copy 
machine, whether it be a standard color tone copier or a laser printer, 
scanned the image to be copied with a fixed-pitch scanning system, it was 
unnecesary to devise overlay grid means. In fact, the modern replicator 
contains such a grid in the fixed - pitch, parallel scan format that is 
used to view the image to be replicated. 
When apprised by friends, who dealt in the field of secure documents and 
negotiable instruments, that the advent of the color copier had almost 
overnight imbued the amateur counterfeiter with the ability to reproduce 
such documents as currency notes, travelers checks, and the like, it 
became readily apparent to the instant inventor that conventional means of 
document authentication would be insufficient to stop an almost 
exponential increase in the preparation of bogus documents. For example, 
with but minor skill and manipulation of controls, a modern color copier, 
especially of the laser type, can make a most credible reproduction of 
United States Bank Notes, travelers checks, drivers' licenses and 
identification cards. So good are the replicas, that department store 
clerks, grocery clerks, bank tellers, change machines, and a host of 
others have been duped by the introduction of these replicated documents 
into the market place. Major efforts of others attempting to solve this 
problem at costs totaling several million dollars have all been 
unsuccessful. In particular, no one heretofore has found a way to provide 
an original banknote or important document which embodies the two 
often-sought features of a copy-proof instrument; for example, one which 
to the unaided eye is both indistinguishable from a prior (genuine) item 
and which is capable only of obviously bogus copier replication. 
SUMMARY OF THE INVENTION 
The problem posed by copier replication has been solved by this invention, 
which is based upon the serendipitous discovery and novel concepts 
described below. Consequently, it is now possible, for the first time, to 
produce legal tender paper currency, genuine travelers cheques, original 
postage stamps, government issued food stamps, important documents or 
certificates and the like, which to the naked eye are indentical to prior 
items of the same kind but, in fact, have characteristics which reveal 
copier (especially color) replications to be obvious counterfeits. 
The instant inventor in the course of searching for a solution to this 
problem accidentally discovered that a color copier replication of an 
original travelers cheque cannot itself be used to produce a closely 
matching copy. Actually, it was found, surprisingly, that no matter how 
the color copier was adjusted to eliminate blemishes or defects apparent 
to the casual observer, the copies made from the first copy always had 
such prominent tell-tales, in one form or another. 
On the basis of his knowledge and skill as an expert in the printing art 
and the science of optics, the instant inventor recognized that in this 
discovery he had the key to solving the copier replicating problem. Thus, 
he conceived the idea of using the bane of the printer to the advantage of 
the counterfeit preventor. He would use the moire effect to reveal the 
bogus color copy of a genuine banknote, for example, by producing the 
banknote image lineations in mismatch to the scanner of a color copier. 
The mismatch would be slight and not noticeable to the naked eye and 
thereby both basic requirements, which no one else was ever able to meet, 
could be totally satisfied. Moreover, the cost of producing such 
counterfeit-proof certificates need not be substantial. The instant 
invention is therefore conceived to counteract a specific illegal threat, 
without having to resort to legislative acts which would in some way 
hinder the technological growth and refinement of the photocopy machine 
industry, and its most noteworthy products. It consists in a product, a 
face-valued document (generally, but not always printed) that cannot be 
replicated by any known color copying system. The instant inventive method 
succinctly instructs the reader in both ways of producing the product and 
in a correlative method for determining whether a suspected document is a 
counterfeit that has been made from a noncopy-protected, authentic 
document which does not contain the nonreplicability factor inculcated by 
the present disclosure. The basic method of counterfeit protection teaches 
the inclusion of lines, dots and/or swirls embodied and integrally formed 
into art, pictures and other forms of images. The grid lines are made so 
as to differentiate minutely in vertical and/or horizontal pitch from the 
linear grids employed by the scanning mechanisms of the machines used to 
replicate these black - white or colored documents. Generically, such 
scanning replicators are typically black and white optical reproduction 
systems, such as office copiers, color copiers, and opticons that are used 
in conjunction with video systems. Subclassed in this generic group are 
the new and increasingly common, laser color and black and white optical 
reproduction systems. After creation of the authentic document, that is, 
one including the grid lines of predetermined pitch, the primary method of 
counterfeit protection, as well as the product thereof, have been 
realized. Any attempt at imitation or replication by means of a 
scanning-type copier will result in the generation of inteference patterns 
and tones which are readily discernable (by the untrained and naked eye) 
from the original (or authentic) document in that the aesthetics of the 
document are distorted, omitted or otherwise completely destroyed in the 
replication. Generally, the dark tones of the authentic document will copy 
darker, while the blurred or light to medium tones will copy lighter, 
whiter or completely disappear. Any attempt by the counterfeiter to 
eliminate the patterns and distortions in the replicated copy, by color 
correction or by angular movements of the faulty replication, will result 
in intensifying the aforementioned lightening and darkening effects; and 
it will cause secondary patterns, latently embedded in the original, to 
appear visible, thus rendering the replication or counterfeit as an 
obvious bogus document. 
A corollary to the primary method for making a non-replicable image is also 
inculcated by this disclosure. In cases where a counterfeit copy has been 
successfully made, say from an authentic document which has not been copy 
protected by the above mentioned method, and the method of replication has 
employed a scanning-type replicator or copy machine, the counterfeit 
document, no matter aesthetically pure it may appear to the naked eye, 
nonetheless contains included lines that already differentiate minutely in 
vertical and/or horizontal pitch from the authentic document's print 
format. In other words, the counterfeit copy now contains the seeds for 
its own detection if the instant inventor's correlative methodology is 
then applied. Such detection requires that the suspected counterfeit copy 
be first viewed and recorded by means of a scanning and imaging device 
such as a copy machine, a television opticon, or the like; and after such 
recording, comparing an authentic species of the original document with 
the recording of the suspected counterfeit and determining if the record 
of the suspected counterfeit reveals moire distortions relative to the 
authentic species. If so, the examining party will be able to confirm that 
the suspect document is indeed a counterfeit. 
Regressing briefly to the "snow fence" effect (that was mentioned in the 
Description of the Prior Art), an alternative method of employing the 
moire effect is also herein disclosed. A moire-distorted pattern is 
replicated quite readily if document imaging is realized by using a rather 
high number of lineations relative to the replicator scan line frequency. 
The notion here is that the "snowfence" slats (i.e., the spaces between 
the replicator scan lines) obstruct more of the authentic image, thus 
distorting the replica. This is most noticable in color counterfeiting. 
With the means taught herein, of producing a non-replicable document of the 
instant invention, as well as means for detecting a bogus copy of an 
authentic document not so protected, financial entities and government 
instrumentalities are now relieved from the potential counterfeit onus 
that was inadvertently placed upon them by the advent of accurate and 
sophisticated replication systems. 
From the foregoing, and in view of the detailed description set forth 
below, it will be understood that this invention has both method and 
article of manufacture or product aspects. Further, in its method aspect 
this invention comprises the step of producing an electro-optically 
nonreplicable original certificate by providing on a matte a lineate 
pattern of visible image-defining lines which are of predetermined 
moire-producing pitch relative to an electro-optic copy machine scan 
protocol. Otherwise expressed, this method includes the preliminary step 
of determining the pitch of an electro-optic copy machine scanner. 
In its article of manufacture or product aspect this invention then, 
likewise briefly stated, is an electro-optically nonreplicable original 
certificate which bears an image defined by a plurality of lines of 
predetermined moire-producing pitch relative to the scan lines or pattern 
of an electro-optic copy machine. 
Further defined in preferred embodiments this aspect of the invention takes 
the form of a multicolor certificate such as a travelers cheque, banknote, 
food stamp, postage stamp, or other government or private organization 
official issue. 
As used herein and in the appended claims the terms "general" "original" 
"legitimate" "legal" "legal tender" "first run" and "authorized" mean and 
intend noncounterfeit issue. Also, the term "matte" designates or 
describes the paper cloth, parchment or other sheet material or tissue of 
which banknotes, travelers cheques, postage stamps, official documents and 
certificates and the like are made.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
By use of FIGS. 1a through 2c, the reader shall now be instructed in the 
method of producing the nonreplicable image of the instant invention. 
Referring particularly to FIG. 1a, there is depicted therein a typically 
printed pattern 10 consisting of various lines 12, dots 14 and swirls 16. 
Those of ordinary skill will readily understand that such an image may be 
printed in intaglio or gravure (more commonly rotogravure) and adaptations 
of these processes. Further, any process of manufacture which represents 
visible images by periodically spaced lines, dots or swirls, whether or 
not printed, (say included by fibre or stain patterns) will produce a 
product giving satisfactory moire results. Methods of etching, photo 
engraving and plate manufacture are beyond the scope of the instant 
disclosure and shall no longer be referred to within this text. 
A grid overlay is revealed in FIG. 1b consisting of an array of parallel, 
equally spaced black stripes oriented orthogonal to a similar pattern of 
black stripes 18. The grid of FIG. 1b is analogous to the earlier 
mentioned snow fence pattern through which one might view a background 
image. When the FIG. 1b pattern is overlain the FIG. 1a printed pattern, a 
distortion 20 in the FIG. 1a pattern results as shown in FIG. 1c. The 
instant inventor defines the FIG. 1c pattern as a type of moire distortion 
pattern resulting from a mapping of the FIG. 1a pattern by the function of 
the FIG. 1b grid overlay. Those of ordinary skill will also recognize 
that, were the function to be reversed, that is, if the grid lines 17', 
19' of FIG. 1b were to become the areas of image transmittal (rather than 
obstruction), and the areas between the lines to be areas of obstruction 
or opacity, the FIG. 1c map would depict the compliment of the 
illustration 20 actually shown. It can also be readily seen that the 
entire grid of FIG. 1b is not required in order to obtain the desired 
results of FIG. 1c. The vertical portions 19 of the overlay grid are not 
required; indeed, the relative ease by which a horizontal grid overlay may 
be realized in the scanning-type replicating machine (or instrument) lends 
itself wonderfully to its use in this invention. The solution of the 
problem to the counterfeiting of printed documents lay in a form of 
reverse engineering wherein the recognition of a grid form of scanning in 
all replicating devices, and a knowledge of the moire effect, led the 
instant inventor to reason that a distorted image would result any time a 
grid-like scanning pattern failed to map any discrete part of an authentic 
document into its replica. If, for example, the horizontal lines 17 of 
FIG. 1b were the nonscanned areas in a copy machine scanning protocol, and 
the interstitial or "see through" areas corresponded to the actual 
scanning lines, the illustration of FIG. 1c would in reality be the 
resultant replica or counterfeit. It can be readily seen that, to the 
naked eye, there might be very little distinction between the authentic 
and the counterfeit documents; however, if the FIG. 1a print were arranged 
cleverly so as to ensure that the greater part of the image was not picked 
up by the scanning protocol, the resulting copy would be highly distorted, 
full of moire interference patterns and significant omissions. By this 
reasoning, the instant inventor devised the invention which is now 
succintly described with the aid of FIGS. 2a through 2c. 
For the purposes of clarity, the pitch between printing lines and dots or 
between scanning lines of a replicating device shall be termed d in the 
case of the printing, and p in the case of the scanner. Turning now to 
FIG. 2a, there is depicted a typical intaglio printing 30, much like the 
printing of FIG. 1a, but less stylized. The lines 32 are separated by the 
pitch distance d; thus, they are parallel and equispaced. FIG. 2b 
represents the scanning pattern 34 of any specifically identified 
replicating device such as a color copying machine, laser scanner or 
television opticon. Scanning on a very carefully controlled frequency, the 
scan lines 36 are parallel and have a constant pitch p. The very nexus of 
this invention demands that d be minutely more or less than p, say from 
half the scan line width up to 50% of p. With an appropriate choice of d 
incorporated into the printed image as exemplified in FIG. 2a, the 
scanning of FIG. 2b maps the printing into the replicated copy 38, shown 
in FIG. 2c. At an arbitrary point where a scan line 36 is superposed 
directly on a print line 32, the replication 37 will be exact. However, 
thereafter and if the print pitch d is properly selected, there will be a 
greatly diminished frequency of overlap and the authentic pattern, to a 
great extent, will be lost. This is shown clearly in FIG. 2c by the 
coincidence of print lines 32' and scanning lines 36'. 
It becomes apparent to the reader what the writer meant by the above 
statement "d be minutely more or less than p", for the mapping essence of 
FIG. 2c would be realized if d were less than p, instead of the indicated 
relationship shown in FIGS. 2a and 2b. The only difference would be the 
location of replica line 37, relative to the various print lines 32' and 
scanner traces 36'. Replica line 37 would appear because, as shown in 
FIGS. 2a-2c, scanner traces 36 would "see" only a smaller set (here for 
illustration, only one) of print lines 32, thus transferring it only to 
the replica. 
One of the most noteworthy attributes of the instant invention is the 
inherent ability of the method and product to defy reconstruction of the 
authentic pattern. For example, those skilled in forms of decryption, that 
is reconstructing an authentic image by purposefully defocusing the lines 
and dots which form the composite image and then rescreening in 
preparation of a re-etching would be frustrated in an attempt to retrieve 
an authentic document from the invention-skewed bogus copy. Referring to 
FIG. 3a, there is shown an illustration 40 that appears on a familiar 
negotiable instrument that is not protected according to this invention. 
The detail 42 in FIG. 3a is the representation of the print pattern in one 
small portion of the document. Immediately below this, at FIG. 3b is the 
illustration 44 of what would be seen in the same detail of a counterfeit 
protected document having a pattern typical of the instant invention used 
in its production. It may be readily discerned that the replicated pattern 
46 bears strong resemblance to that shown in FIG. 3a. In an attempt to 
reproduce the pattern of 3a, the pattern in 3 b is deliberately defocused 
or blurred 48 as depicted in FIG. 3c. After this blurring process, a 
counterfeiter would rescreen the image to prepare a new etched plate in 
order to reproduce an authentic looking document. FIG. 3c illustrates the 
FIG. 3b pattern as it would appear blurred. However, were the 
counterfeiter now to screen the FIG. 3c blurred pattern, the result would 
be the pattern 50 of FIG. 3d. A cursory comparison of the FIG. 3d pattern 
50 to the detail 42 of FIG. 3a evidences the futility of such a technique, 
if applied to a document prepared according to the teachings of the 
instant invention. Generally speaking, the FIG. 3b rendering of the FIG. 
3a authentic document contains imaged areas that are anywhere from 35% to 
50% reductions of the pristine image. Further, an attempt to replicate, on 
the offset press, the attempted reconstruction at FIG. 3d will result in 
an image containing an additional 50 to 75% degradation in detail and hue. 
To this point, the instant inventor has taught the invention in terms of 
varying the pitch distance between image lines so as to "detune" them or 
create a dissonance between the print pattern in the document and the 
known frequency or pitch pattern of a scanning device. That is not to say 
however that an exacting print of such nature must always be had in order 
to embody the teachings of the inventor. A highly practical method is 
devised whereby the pitch in the printed document may be arbitrarily 
varied, thereby acquiring the benefits of the instant invention. This 
method is to simply change the dimension of lines and dots on a document 
so as to inherently vary the pitch between the various pattern elements. 
Accordingly, the instant inventor suggests that, after a document of the 
type contemplated herein has been printed, the medium upon which it is 
printed be dimensionally altered, generally by the application of heat. If 
performed on a suitable printing matte, the imprinted pattern will be 
subtly altered and the basic concept of the invention incorporated 
therein. It is recommended that a high quality, high rag content paper or 
a high quality rice paper such as is used in the printing of currency, be 
utilized. 
The benefits of the aforementioned technique can be casually acquired by 
documents that are subjected to handling and indeed, those which have been 
counterfeited, especially since the toner application process of a color 
replicating device employs a matte-warping (distorting) heat process of 
the type described above. A replication of such a distorted document, by 
either a color o black and white copier, or a scanning video opticon, will 
produce an image that is literally full of moire distortions. Thus, it 
follows that if one attempts to copy or video scan a photocopy counterfeit 
of an authentic document (color or black and white), the result is a 
severe moire - distorted image, because the heat of the counterfeiter's 
copier has distorted the copy matte, and thus the pitch of the authentic 
document's image lines, as taught by this disclosure. 
Another methodological corallary may be employed in cases where the 
scanning machine-replicator utilizes a scan line of greater than customary 
width. In such a situation, use of a document imaging process similar to 
that disclosed herein, but employing a much smaller lineation pitch (with 
a concomitant greater number of lineations) is most efficacious. If the 
lineations exceed 250 to the inch, the moire effect in the replica will be 
noticeable to the unaided eye, even with standard and unsophisticated 
copiers/replicators. This lineation frequency (250 lines/inch) is 
significantly higher than that used in the industry, today. 
Myriad applications of the teachings in this disclosure are available to 
and may be made by those of ordinary skill and are limited only by the 
claims hereinafter appended.