WO1991011331A1 - Anti-photographic/photocopy imaging process and product made by same - Google Patents

Abstract

Several techniques for producing nonreplicable images. Images on mattes (M), particularly those of face value documents, and mattes are produced so as to acquire nonreplicable documents (10). Rendering of images as arrays of lineations (20) made of lines (12), dots (14) and swirls (16) in a predetermined pitch (d) format that varies minutely from the scanning pitch of a photocopier is detailed. The further rendition of these images as lineations, preferably of just dots and short hooked lines, surrounded by photographic disturbance medium such as lighter dyes/paints/inks/resins or print stuff arrayed in omnidirectional format frustrates photography copying as well.

Description

AN I-PHOTOGRAPHIC/PHOTOCOPY IMAGING PROCESS AND PRODUCT MADE BY SAME

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates generally to protected documents, those documents having some intrinsic value that is readily recognizable on their face. More particularly, the instant invention deals with the method for producing a document that will be nonreplicable by modern photographic/photocopy techniques. Specifically, the photographic replication which is to be defeated by the instant invention is that which would result in or could be used to provide a color transparency or a high resolution positive (or negative) from which a printing plate may be made in order to reproduce the document that was photographed. Thus, the Field of the Invention is properly that art which deals with document security systems, antiphotocopy documents and antiphotographic documents, insofar as they are used to thwart counterfeiting activities.

The instant invention, although unique in its own right, derives from one of the instant inventors ' inventions dealing with nonreplicable documents and methods for producing same, subject of United States Patent Application, No. 298,020 ('020) filed on 18 January 1989 and entitled "COUNTERFEIT PREVENTION", priority established by PCT/US 90/00221 in WO90/08046, published 26 July 1990. Those documents shall provide a significant portion of the background topic in the instant application.

Discussion of the Prior Art

In the early 1980's, with the proliferation of many extremely fine photocopiers, it became apparent that, as the science progressed in terms of authentic replication and quality of print, the likelihood of counterfeited documents, including currency, would soon become a problem of national significance. Those skilled in the art of printing protected documentation, almost as a whole, attempted to create techniques and products which would frustrate the amateur, copy machine-operating counterfeiter by contriving documents which, when scanned by an electro-optical scanning system (such as that found in a photocopier machine or an opticon) , would produce replicas which were darkened in tone or hue, or revealed hidden images, the most common hidden image being the word "VOID". A most interesting and relevant example of such art is disclosed in US Patent No. 4,582,346, issued to Caprio et al in April 1986 for a DOCUMENT SECURITY SYSTEM. In that patent, a protected document included background printed matter and line pattern printed warning indicia, a compound imaging process akin to "cloaking". Upon an attempt to replicate the document by a copying machine, the warning indicia are slurred (a characteristic of all types of photocopiers) and become visible. Thus, by the patentee's own disclosure, the technique exploits copier directional slur, a phenomenon caused by toner drag, or the elongation of the trailing edges of images as toner is deposited onto copying drums. The resultant Caprio product is a protected document comprising a substrate having a surface, background printed matter on a first portion of the surface, and warning printed matter on a second portion of the surface, within the first portion. The warning printed matter is formed such that, upon xerographic copying of the document, the warning indicia slurs to become visible. The background printed matter is a dot pattern, printed on the face surface with a dot pattern screen of 5% density and 133 rows per inch. This density and pitch (the number of rows per inch) is significant in that, after one of the instant inventors had made the previously mentioned nonreplicable document (see Field of the Invention), a retrospective look at the Caprio et al. process revealed that they, although having succeeded in producing a very expensive and intricate security document, had missed the knack of acquiring a truly nonreplicable document because their invention had been directed toward printed indicia that the copying machine could actually "see", that is, detect and photoprint. Therein lies the truly subtle secret between a very expensive and highly contrived product and one which is simple, elegant, inexpensive and which has additional benefits that not only serve as an adjunct to the nonreplicability of the instant inventors' document by photocopy machine, but also, when practiced in its fullest and most comprehensive sense, provides a modicum of antiphotographic characteristic as well. Application '020 reveals and exploits most of the secret, save part of that now discussed herein.

Mowry, Jr. et al., in U.S. Patent No. 4,310,180 discussed the method of making a protected document. They disclose a protected document, such as a negotiable instrument, which is to be protected by their technique from illegal copying by color copiers. Their method is, in some respects, similar to predecessor methods, essentially preprinting a particular word, warning or cancellation phrase pattern in a half tone or multi-tone on a document and, thereafter, camouflaging the pattern by placing over the cancellation phrase a random line background mask effecting the disappearance of the cancellation phrase into the background design. The instant inventors term this "cloaking" because there is a definite intent to cover one form of visible print with another, a technique and expense they avoid.

In the interim, the period between the above Mowry, Jr. and Caprio type inventions and that of the instant inventors, other techniques were attempted such as microimaging in certain locations of the security document. For example, government printing offices, including the United States Bureau of Engraving, fell upon the technique of including microimages in the borders and edges of pictures (images) and portraits (also images) in paper currency. When attempts are made to reproduce such paper currency by color photocopier means, the microimages are lost. Unfortunately, the loss of an image which- cannot ordinarily be seen, is generally of little consequence when one considers the fact that most currency exchanged in the open marketplace is rarely scanned by the handlers with a lens any more powerful than the unaided human eye. Thus, not only do the counterfeits of these currencies appear genuine to the casual observer, but the genuine notes are extremely expensive to produce, being attainable only through high quality engravings used with intaglio printing techniques. What was needed, and provided by one of the instant inventors, was a document which, when reproduced by the best of modern color copiers, would be obviously bogus. The invention disclosed and claimed in United States Patent Application No. 298,020 makes it possible for the first time to produce legal tender paper currency, genuine traveler's checks, original postage stamps, government issued food stamps, important documents or certificates such as driver's license and identification papers, and the like which, to the naked eye are identical to prior items of the same kind but, in fact, have characteristics which reveal their copier (especially color) replications to be obvious counterfeits.

It was discovered that a long-time bane of the printer, moire distortion, could be turned into a benefit if the proper philosophy were pursued. The moire image, in the optical sciences a virtual image because it is not the reflection of the real object nor the exact image being projected from the real object, is observed when an interfering grid is placed between the object to be observed and the observer. Analogously, this occurs in a photocopier or any electro-optical scanning device such as a television opticon when a grid of some form prevents the detecting device (or surface) from " seeing" or sensing all of the light reflection from the object or target. It was reasoned that such a grid indeed exists in the aforementioned photo- " copying devices; and, that grid is the scanning pattern of the device itself. Quite literally, the device "sees" only the image directly under its scanning or imaging field; and that is an array of straight lines (the scan lines). Thus, if the device does not scan an object, it does not "see" it, does not record it, and does not replicate it. It is thus "blinded" by a virtual grid corresponding to the scan line spacings or "not see" zones. It was recognized that in this discovery lay the key to solving the copier replicating problem. We used the moire effect to reveal the bogus color copy of a genuine banknote, for example, by producing the banknote image lineation pitch (see definition hereinafter) in purposeful mismatch to the scanner frequency of a (color) copier. Additionally, the lay-down or printing pattern is deliberately altered, portionwise, in azimuth and/or pitch throughout the document by either a single printing (from a single plate) or a montage of either separate printings or a special compound (image) plate.

The invention was conceived to counteract a specific illegal threat, without having to resort to legislative action which would in some way hinder the technological growth and refinement of the photocopy machine industry, and limit its most noteworthy products. Quite simply, if a photocopier (of any advanced design) relies upon a discrete scanning protocol, it can be defeated as a counterfeiting device by incorporation of the '020 invention therein.

During the later productions of the earlier (nonreplicable document) invention, as partly disclosed in '020, it was realized that the characteristic most notable in- the attempted reproduction of the nonreplicable document, namely missing details (in addition to moire skewing), was also present when an attempt was made to produce a positive or negative image (photograph) transparency. Such photographic techniques are employed when a counterfeiter desires to produce a photo-etched plate for printing some security document. At this point, it was reasoned that, since this phenomenon was not present when ordinary existing security documents were photographed, there had to be some causative agent in the invention (to which we alone were privy) that was inducing nonreplicability in a photograph. It was from this somewhat serendipitous discovery, that the instant invention was generated.

Before summarizing and disclosing the instant invention in detail, it is first necessary to define several terms which shall be used hereinafter and with which the reader should familiarize himself/herself so that a comprehensive understanding of the instant invention will follow. Definitions

Bloom or Flare. A phenomenon where light, either direct or reflected, overwhelms a recording medium, surface or device such as a photon detector, an occular retina, a photographic emulsion or the like, so that the recording medium (or surface) does not record or sense all of the content in contrasting darker areas of the image, specifically the lineations comprising the image..

Bloomable or Flareable Image. An image which reflects light disproportionately from the various pixels that compose the image, by projecting to a recording medium diminished contrast between lighter and darker areas because of the preponderance of lighter pixels adjacent a darker one.

Dissonance. Mismatch between frequencies such as in different line pitches or color spectra. The term generally means "out of tune".

Image. A marking made on a matte or integrally formed therein. An image may be lineations, pictures or portraits. The pictures or portraits are geometric patterns or images of persons and are generally comprised of various lineations.

Lineations. Multiple lines in an etching, print, or similar reproduction which are comprised of dots, lines/hooks and swirls and comprise the detail of which an image is made. A lineation may be straight or curvilinear and is merely a general description of in-line dots, lines/hooks and swirls.

Line Pitch. The frequency (f) of repetition in printed indicia such as lineations. Matte. A substrate for containing an image therein or thereon. In the instant art a matte is generally, but not always, a high quality rag or rice paper, polished to varying degree. It may also comprise printing plates , platens or similar picture formative means.

Picture Formative. Something such as an engraving, a photo-replicator or the like that is used to make images on suitable mattes by facilitating transfer of inks, dyes and similar marking stuff. .

Replication. An exact image or picture reproduction, true as opposed to imperfect, bogus or inaccurate. Hereinafter, replication, replica, etc. shall be used to express a true reproduction; while nonreplication, nonreplicable, etc. shall mean that a document or image having such characteristics, when copied, is counterfeit or bogus to the casual observer.

Stuff. The material out of which something may be shaped or made, raw or unwrought material.

SUMMARY OF THE INVENTION

Several techniques are employed to produce a photocopier or photographically nonreplicable image or document containing images:

(1 ) The rendition of images as dots surrounded by lighter dyes/paints/inks or print stuff and arrayed in omnidirectional formats comprises the heart of the instant invention, the basic bloomable image;

(2) subtle hue gradations on a matte for the purpose of decimating the reproductions is of significant importance, and has by itself the ability to frustrate accurate photocopying;

(3) the invention disclosed in the prior art "nonreplicable document method", namely, the inclusion of lines, dots and/or hooks/swirls (lineations) embodied and integrally formed into art, pictures and (other forms of) images so as to differentiate minutely in vertical and/or horizontal pitch from the linear grids employed by the scanning mechanisms of electro-optical scanning and photocopy machines is used as an adjunct to the image of (1 ) ;

(4) use of a matte having definite relief, that is, high and low areas as is experienced with use of high quality rag bond and the like accentuates unequal reflection character; this dissonant reflection character is further enhanced by using a dry offset printing technique, often coupled with image lineations done by intaglio printing, so as to effect extremely erratic reflectivity over the entire matte;

(5) omni-directional placement of the various lineations comprising the image, which enhances the bloom or flare aspects of the image; and

(6) placement of the thinner (less dense) lineations of a bloomable image at a pitch beyond the resolving capability of a spherical camera lens and the emulsion grain of high resolution films, at least greater than 180 lines per inch. at which this latter and all of the aforesaid techniques are enhanced relative to the invention's ability to frustrate photography of its images.

(7) xerographic imaging of the invention onto photosensitive plates or with transfer of a resinous powder to darker paper (matte) with subsequent thermal fixation. A fixed resin images glistens under photo light and blooms or flares spectacularly. This is another application of (1), above.

(8) The most expedient methods for making documents or picture formatives of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Of the Drawings:

Figure la is a small portion of a printed image;

Figure lb is a nominal grid overlay;

Figure lc is the superposition of the Figure lb grid on the Figure la print;

Figure 2a is an alternate embodiment of a print similar to Figure la;

Figure 2b is a stylized rendering of an image with a detail of the lineations forming the image;

Figure 3 is an artist's sketch of a well known portrait which appears on a national currency bill;

Figure 3a is an artist's rendering of the print detail of the Figure 3 image embodying the instant invention;

Figure 3b is an artist's rendering of a copy of the Figure 3a image produced by a modern photocopying machine;

Figures 4a-4d are illustrations of the types of lines, dots and hooks used to construct lineations of the invention in graduated detail;

Figures 5a-5e comprise a series of illustrations which depict a general method for placing the image into picture formatives such as printing^"plates;

Figure 6 is flow sequence of a method for making documents of the invention using a photocopier; and

Figure 7 is a flow chart similar to Figure 6, but applicable to a non-photocopy production method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The image making techniques employed in the instant invention derive, in large part, from prolonged experimentation and practice with the invention disclosed in application '020 and also U.S. Serial No. 473,903, ('903), filed on February 2, 1990 on which priority for this application is based. Article Embodiments

Referring more specifically to the first three figures, Figure la discloses the '020 and '903 inventions 10 rather succinctly. An image is created, on a suitable matte M by forming lineations, that is, curvilinear marks that are comprised of lines 12, dots 14 and swirls 16, into pictures, portraits or other forms of visible imagery. "Curvilinear", as used herein, means small curves or hooks at the ends of dots or lines. This is done according to a certain protocol which is illustrated in the following Figures lb and lc. In Figure lb, the reader observes a simple grid barrier comprised of opaque horizontal slats 17 and vertical slats 19. The spaces between the grid elements 17, 19 are indicated generally as voids 18. When a grid of the Figure lb type is laid over a Figure la of printing or imaging (assuming that the grid spacing or voids 18 is immutable), the Figure lc illustration demonstrates dramatically how a good portion of the image of Figure la would be lost to an observer by the interposition of the opaque grid 17, 19. Quite matter of factly, the vertical portions 19 may be removed and the reader can sufficiently imagine that, absent 19' elements of the interfering grid, the remaining image would still be sufficiently distorted so as to be apparent to the ordinary observer. This phenomenon, a very noticeable phenonmenon, results in what is termed a moire pattern or color skewing; and, it occurs any time an observer attempts to view or record what is essentially a virtual image. The term virtual image is used herein because the viewer or recorder does not see/sense an image as it is accurately portrayed on its matte or substrate medium, but rather as it appears to the senses/sensor. It is an image which has been distorted by some interfering grid-like phenomenon. The phenomenon may be real, such as the grid of Figure lb or it too may be virtual, such as an inability to see or perceive. For example, if a person were to observe an image through a defective eye, say an eye which possessed a damaged retina so that the entire image was not sensed, the actual perception of the observer would be entirely different from that of an observer with normal vision. Thus, the philosophical transition made by the instant inventors is to select a virtual grid for an actual one. This is done by first determining which type of device will be used to record a particular image — in this case, the imaging^'apparatus (recording) is a video scanner (opticon and the like), a photocopier scanner or a camera. In the case of the first two devices, an image 10 is made on a suitable matte M with lineations 20 (comprising dots, lines and swirls) spaced at a distance which will be minutely less or more than the scanning frequency, or some frequency factor such as (f ÷ interger), of the aforementioned devices. Thus, when the optical scanning devices scan a document containing the above described image format, the points and lines along which the device scans, or "sees", will be recorded (spaces between scan lines are not) and later transferred to another matte in the reproduction protocol. Thus, for a short portion of its scanning protocol, the scanning device "viewing area" will be in registry with discrete image parts and the machine thereby recording lineation 20 of the image 10. However, and because of the purposeful line pitch dissonance between the machine or the device scanning pitch and the image lineations 20, the "seeing line" of the scanner will soon be out of registry with the lineation pitch of the image 10 and, since the device will no longer be able to "see" all of the lineations 20, the device will not be able to record and reproduce the document bearing the image with any reasonable degree of accuracy. Hence, the instant inventors use the term "nonreplicable document" to describe any document bearing an image such as that first described (10) because it cannot be replicated accurately.

The illustration at Figure 2a explains in a somewhat more detailed fashion the invention related in Figures la - lc. Therein, the reader will note that the invention 10 comprising lineations 20, that is, lines formed of dots, lines and swirls, are arrayed so as to have a definite, predetermined pitch d. At this point, a second aspect of the instant invention is taught wherein the thickness of the lines or lineations 20 is varied, from line to line and also within the same lineation. At the top of Figure 2a, a lineation thickness begins at the left hand side with a thickness somewhat less than the lineation pitch d, that is, the distance between lineations. This illustration shows a constant lineation pitch d, but according to the teachings of the instant inventors, all that is necessary is that the pitch distance d be an amount to purposefully create dissonance, i.e., more or less than the scanning pitch of the scanning device which is to be frustrated. For most of the available color copiers on the market today, those capable of making a counterfeit document, pitches of greater than 180 lines per inch is generally sufficient. In the case of a well defined threat, it may be advisable to prepare face value documents, such as banknotes or currency, not only with a document lineation pitch slightly above or below the pitch protocol of the threatening device, but to embody varying pitches, pitch factors (f ÷ integer), azimuths and other aspects of the instant invention. Such an adoption leads to one of the most significant aspects of the instant invention, that which lends an antiphotographic character to the image 10, as well. In Figure 2a, the bottom left hand lineation, comprised essentially of characters such as a lower left hand dot 14' is of a thickness significantly less than the pitch distance d. This allows practice of two features described in the Summary of the Invention, the use of subtle hue gradations on the matte which is serving as the substrate for positioning of the image thereon, and the creation in that image of a blooming or flaring characteristic.

Relative to the use of the bloomable image and the tonal gradation, the instant inventors will digress slightly to more thoroughly explain these facets of the invention. Relative to tone, as it applies to the printing of documents, the actual print must be of a certain opacity and the density thereof should be at least .05 in reflective density, where such reflective density is proportional to the area that is being covered by the print. In the printing field, opacity is related on a relative scale of 0.0 to 3.0, the former being white-white and the latter, solid black. By contrast, in the photographic arts, black is 3.02. The average density (reflective) of a solid image in the printing art is 1.60.. Reflective density on paper or similar substrate (matte) is also dependent on the substrate composition — called "trap". In such a case, the matte surface, being uneven allows the ink image to bleed or peek through to the other side and, in some cases, allows it to actually soak through to the second side or other side of the matte. This phenomenon is called "offset". This is best exemplified if the reader examines a currency note and observes on the obverse that images bleed through from the reverse side. The offset phenomenon is only one factor, albeit an important one, in reducing the reflective density of the ink on one side of a printed document. Factors contributing more or less to offset are tack and pressure, of the ink and press, respectively. It stands proven, therefore, that if a matte having definite relief is used, either using a matte design or making a preliminary intaglio "pressing" without ink, an unequal reflection character is acquired and this dissonant reflection character is further enchanced by using a dry offset printing technique, often used by the instant inventors with image matter that is done by additional intaglio printing (with ink),"'so as to effect extremely erratic reflectivity over the entire matte. Thus, an antiphotographic character is incoroporated in documents printed according to the instant invention. Hereinafter, explanation will be made regarding the use of tonal gradations on or in the base matte which will have further effect on the overall reflective density of an antiphotographic document.

In photography, as well as electronic scanning, a phenomenon known as "flare" or "bloom" is known to exist. Indeed, patents have been obtained for printing techniques and products (made from the techniques) that incorporate reflective inks or dyes. The reflectivity of the inks or dyes used is obtained by including aluminized mylar particles or other reflective particles in the printing inks or dyes; until now, "bright" printing media have not been used. Irrespective of how the patentees term such techniques, what they mean to inculcate is the use of media having dissonant reflective densities within a document. When such documents were photographed years ago, emulsion grains and ASA or din values were not yet obtainable that would be able to resolve the reflective discontinuities emitted or reflected by such documents. Today, however, with high speed, high resolution emulsions, something more is required to acquire a flare or bloom phenomenon in a document. Flare is essentially the effect of the interaction of lens curvature (in the camera) and reflections from juxtaposed light and darker surfaces in the document's image. The brighter light reflections have a more pronounced effect on the film and are gathered more readily by the curved lens; thus, the light areas appear to "bloom" or flare, thus swamping out portions of the darker image, particularly at the margins. Although it would seem that external lighting could be all but eliminated from the photographic environment, light is still required to activate the film; and where the light-dark juxtaposition still exists, so does the flare or bloom. Referring once again to Figure 2a, this character is incorporated in the instant invention by the spacing 15 of the lineations 20 so that the resultant images must be comprised of lineations having small enough thickness to exhibit a very low reflective density of from about 0.01 to 0.10. In such image areas, the resulting photograph of the document will reveal omissions of the image or extremely reduced replicas — in both size and density.

A very valuable, although somewhat limited, system for incorporating flare in the invention has also been discovered and used with considerable success by the instant inventors. In seeking elements that would induce the flarable feature so that camera, photocopier and telecopier machines or devices would be equally frustrated in a copying or transfer attempt, the inventors successfully applied a resinous powder to several forms of matte, here papers that were somewhat darker than the usual copy paper. When the powder is permanently fixed by heat, and several thermal cure or fixation methods are known, it results in an imaging which is clearly visible in ambient light because each indicia glistened, thus making the pattern of indicia or the image highly visible. However, any attempt to recopy the finished image by photographic means is unsuccessful and attempts to recopy by xerographic (photocopy) means or any optical scanning means (telecopier), produced absolutely outstanding results in that the resultant product was completely darkened. In this particular case, the bloom or flare aspect of the image indicia predominated over the line pitch/azimuth/dissonant character and, in fact, will suffice under the circumstances of use mentioned herein.

Figure 2b depicts, at the left hand side, an artist's rendering of what is normally a printed image seen in the traveler's check printed art. At the right, a detail of such an image could be rendered accordingly. The invention disclosed in Figures 1a - lc is incorporated in sectors ranging from about 0 degrees to about 45 degrees in arc. The reader should note that Sector I is skewed from Sector II. Sector III, which is in alignment with Sector IV, is offset pitchwise so that a scanner, clearly "seeing" a line in Sector III, would probably miss its counterpart in Sector IV. This is assuming, of course, that the person attempting to counterfeit the image would have turned it so that the scanning device would scan orthogonally and not in the usual bottom to top fashion. Sectors V and VI differ in pitch d and in pitch azimuth (arc d) . Such a torturous layout is felt necessary to thwart counterfeiters that would attempt to take several scannings along differing scan azimuths and use a computer to resolve inaccuracies or omissions on a pixel-by -pixel basis. Finally, Sector VII shows an embodiment of all of the aforesaid techniques, save the tonal gradation, as may be embodied in a document utilizing the invention in its fullest sense. In actual practice, and using practically any available color copier, an image created (i.e., copied) in the detail of Figure 2b, using a three or four color scheme would be virtually nonreplicable in the sense that a casual observer would readily recognize the moire skewing (colorwise) and omissions in the counterfeit product.

Figure 3 is an artist's rendering of the Jackson image as it appears in a United States twenty dollar bill. Since United States currency is produced from an engraving, and printed in the intaglio method, a Figure 3a detail would illustrate the previously described facets of the instant invention, with the exception of tonal gradation. Were such a document copied on a color copier, even of the most modern type, the resultant (counterfeit) image of Figure 3b would contain such obvious defects and omissions that the counterfeit virtually would be unpassable. Most noteworthy in the Figure 3b effects would be the omission of detail 40 above the eyes, and loss of a great deal of the horizontal grid integrity 42 from the background area of the portrait. In an attempt to adjust for loss of contrast, the counterfeiter would increase the toner laydown, thus acquiring a great deal of toner slur on the aspects of the image that were "seen" by the copier scanning device. Such an attempt to recreate background in darker toned areas would result in an accentuation (further decimation) in the areas of omission. Worse for the counterfeiter, toner slur would become more pronounced, and since the copy machine cannot reproduce what it has not seen, the attempted contrast adjustment will only serve to effect brighter spots where there was normally (or originally) a light hue. On some modern copiers, an averaging function is used for supplying toner (extra laydown) to compensate for nonscanned or "unseen" indicia in documents.

One final aspect of the invention, relative to the article made, is worthy of discussion, the use of tonal gradation for the purposes of decimating photographic reproductions-. In the newprint industry, the compositer (hand typesetter) , now "pastes up" old ads from previous printings with new copy on the same page. The old copy, because of aging, has varying shades of "yellowing". Such variable shading is similar to what the inventors term tonal gradation. Such advertisements contain writing and illustrations in line form, as well as half-tone. The procedure is to produce a negative of the full "paste up" on an offset reproduction camera. The bane of the compositer is the presence of the varying tones of yellow in, around and juxtaposed to type. These varying tones of yellow, or tone gradations, are apparent when compared to the overall opacity viewed in a negative area of the reversed image of the new ads. Thus, the sheet of total material, i.e., the matte with images thereon, suffers intermittent variations in tone and, as a whole, lacks consistency during reproduction. This problem actually arises because the darker shades of yellow retain density (in the negative) that will print darker than white (or a shade of gray) and all lighter shades of yellow, including white, will exhibit a similar effect. By purposefully incorporating, in the instant invention, a tonally graded (graduated) matte, the reflective densities of an overall document are further altered. Although making such a tonally graded matte is more in the province of the stockmaker, the instant inventors choose to use one particular technique that is particularly effective and offers an additional enhancement to the preparation of a security document or face value certificate.

One of the methods for producing a document with the instant invention and, particularly the invention of the '020 application is to make, as close as possible, a photoreplica of a true document on a modern color copier. Because the matte is altered by the heat of the developing process, the lineations of the replicated image will differ minutely from the scanning pitch of the copier. Thus, the replication will contain the instant invention. If the replication is made onto a plate, documents may now be printed containing the invention which has been literally provided by the copier. This was first taught in "020 when the instant discovery, that a copy machine could not accuately replicate its own copy, was first revealed. The replication may also be given the "feel" of a true printed document by merely overprinting or underprinting the copier (copy) with a common printer's varnish. The varnish would be applied by means of a print formative such as an intaglio or offset plate. Such a varnish is clear and often without hue or tone, but may contain such. More than one layer is generally preferred. If at least one layer of varnish is applied by over/under- printing a copy machine replica, a document will be obtained having all the looks and "feel" (that is, sense to the touch), of a genuine certificate. In fact, it may serve as the genuine certificate and thus, embodying all the aspects of the instant invention, replace the genuine certificates of that type that are so easily counterfeited. If the printer wishes to incorporate• he tonal gradation facet of the instant invention, more than one overprint of varnish may be used. This time using a different toned or hued varnish. In this instance, the plate for such printing must be made so that the varying tones or hues of varnish will be layed down between the lineations 20 or some other refraction-disturbing pattern is employed. As those of ordinary skill may readily surmise, it is not necessary to apply this tonal gradation technique only to a photocopy or replica; but rather, it may be applied to any printed document, particularly offset printings.

In addition to, or instead of, overprinting with printers varnish, a primary coat of varnish may be applied directly to the matte. Then, if that coat is one defining an image not visible to the unaided eye, that image will be revealed upon attempted photo replication of the finished document because the overprinted image is not seen by the photo replicating machine scanner. Moreover, the varnish image will be replicated either darker or of different color from the original coat image, a distortion caused by the differences in refractive indexes of air and varnish (even though both appear to be clear or nearly invisible).

It has also been discovered that this image result can be consistently obtained whether or not one or more overlays of varnish are applied to the printed document.

It has still further been discovered that it is possible to create, in effect, a watermark by using as the primary coat a varnish which will penetrate the matte sufficiently that the varnish image is visible to the eye when the document is held up to a light source. Thus, although the matte has no transparency, the varnish image shows clearly; and if that image is a positive, it will replicate as a negative and vice versa.

On the basis of these discoveries, one can now produce a certificate bearing an image in varnish which is visible to the unaided eye as a watermark and is replicable on exposure of the reverse side as either a positive or a negative; and the replicated portrait can also be behind a replicated pattern of choice printed on the reverse side of the certificate in a form which can be seen by the copy making machine scanner. Thus the original mismatch concept of this invention described above may be used to prevent counterfeiting of the front and/or back of a certificate and the printers varnish image concept of this invention may be used to prevent counterfeiting of both the front and the back of the certificate.

Figures 4a-4d are graduated serial definitions of illustrations depicting, first in Figure 4a, a portion of an image comprised of lineations of a certain pitch and an inner section 60 thereon. Figure 4b is a detail of Figure 4a taken at circle 4b. This is done to show the reader that the indica are lines, not only of different azimuth, but of different pitch, as well. Figure 4c is a larger detail of the Figure 4b intersection 60 area. Finally, Figure 4d is a blow-up and exaggeration of the intersection 60 area depicted as a rectangle in Figure 4c. In a construction of an image according to the invention, lineations 20 are depicted as a series of lines, dots, hooks or swirls arranged according to a consistent pitch d¹ or varying pitches d' ' . Machine scan lines lη and 2 clearly illustrate how components of various lines would be "seen" by a photoscanning means, but also, critical portions would not be seen and recorded between the lines, herein depicted as a space s. As will be seen later herein, a couple of the techniques for embodying the invention in a document rely upon the maker of the particular picture formative (generally a printing plate) to take careful cognizance of the factors depicted in Figure 4d. Figure 4d is depicted with but two colors, a dark and a white, or black and white. Thus, an image may be formed in black lineations or what appear to be shades of black and gray. Were three colors to be used, the same techniques would apply for assuring that various components of the color would not be seen if other components were to be seen. Figures 5a-5e illustrate how one would go about making a plate formative, either by computer or hand engraving, so that the invention would be embodied in the formative and, of course, in the resulting document printed by the formative.

Figure 5a represents a three color-component pixel X and the succeeding Figures 5b-5e illustrate the sequence of actions that would be taken to embody pixel X into a document bearing the invention X' . The process proceeds essentially as follows: a negative is made of the image thus rendering the three colors a, b and c distinctive as shown in Figure 5b. Then, as depicted by Figure 5c, a positive is made of.pixel X screened with a preselected screen frequency as shown in Figure 5c. Here, as in Figure 4, 1- , ±2, etc. represent the photoscanner or photocopier scan lines; and s represents the spaces between the "seeing" scan lines, or the "no see" zones. Figure 5d represents the pixel X as it would appear on a three color plate with the invention formed therein. The reader should note that when making the plate, and in order to maintain the proper color, tone and hue that was originally that of pixel X, it is necessary to compensate for the lack of the color components by making deeper wells or using darker color components to print the document. Thus, the document pixel X', as shown in Figure 5e is composed of colors a', b' and c' to indicate their color and tone difference from the pixel of Figure 5a. Methodolocry

Beside the obvious method of making a picture formative of the invention, that is, hand engraving a predesigned image with the invention, including pitch variations and azimuthal change, as well as lineation portions in one, three or more colors, there are the automatic/automated methods such as: direct screen image creation, electronic scanning creation, photocopier creation, direct plate image creation and indirect gravure or intaglio plate making.

The first, direct screen image creation was essentially described in the description of Figures 5a-5e. A film negative of a picture (in whole or part) is photographed. A variable tone line screen, which emulates the line screen of a laser black and white or color copier, is placed in registry and in contact with the negative and both are placed in contact with a new film. In effect, the first grid (photocopier scanning pattern) is placed over the picture or document image. The thickness of this grid is important, as well as its pitch. The new film is then exposed and developed. This film is either a negative or a positive and is used to produce a printing plate of the invention image as shown in Figure 5d. To maximize the effect of using the invention imagery as a montage, several parts of a document are so treated with screens of differing pitch that are rotated about the z axis of the images' x-y planes. The various screens correspond to various photocopier scan copy (frequency) protocols. The instant inventors are familiar with the following addressed techniques of copier and computer operation, but claim no expertise therein. Nevertheless, a skilled copier, computer operator or printer is capable of acquiring the articles of the invention by application of the methods that follow. Relative to electronic scanning creation, a picture formative (plate) or document of the invention may be created using many of the computer-controlled systems that are available today. Reference to Figure 6 will give the reader a broad view of such a method. An original copy, engraving or a picture is scanned and entered into memory of a digitized computer imaging system. Also prestored in the memory is a digitized line screen that is a geometric match to the line screen of a selected laser copier. Several such line screens may be stored in memory for such a purpose. The image that was scanned is presented on the video-corn or monitor, and enhanced by contrast and size for reconstruction. The line screen is also summoned as a screen overlay and the image is then reconstructed to follow or "map into" the line screen paying special attention to place critical color components in as thin lineations as possible. Subsequently, a negative is output and is used to produce a printing plate with the invention's image. During the mapping process, the various screens and azimuths may be employed granting the finished negative the multi-azimuth and pitch variations of the aforementioned montage.

Photocopier creation is perhaps the most expedient means of creating the invention in a picture formative. An original copy artwork, engraving, or picture is placed on the platen of a laser copier. Film transparencies are placed in readiness in the blank paper tray of the copier, hereinafter termed "film tray". Copier adjustments are made in that the laser potentiometer is adjusted to produce maximum beam sharpness while copier settings such as "detail" and "contrast" are adjusted to produce the sharpest copy line image and the "black mode" of the copier is activated. Changes to pitch, azimuth, line or dot pattern, without changing the astetic look of the original, may be made by numerical control subsystem (if available) to the copy. Special shadow effects may be introduced into the medium-to- dark tones with a redrawing of original lines to create sharper lineations. The copy may be divided into one or more sections, with each section being placed on a copier platen at a given azimuth which empirically is seen to produce the greatest interference between the original design image and that resulting from the new azimuth placed on the platen. Each change of azimuth, relative to the original document, is treated as a separate section and the film transparency is produced of each. One master film is produced of the copy as a composite of all the parts. The master film is then selected for registration and each section is then registered to (mapped into) the whole original by the above process. Separate masks are created of each section or part of the whole copy that was selected bearing an azimuth change. Positives of the masks are then created and, a new piece of film is placed in the film tray and each mask is exposed separately and in registry with the selected section while masking the background around it with the positive to create a film negative (or positive) which is a whole of the original. The film is then used in a conventional manner to produce a printing plate for the replication of invention documents.

Direct plate image creations is also an expedient manner of producing picture formatives (plates) and the invention documents by use of a copier. In this technique, a plastic or paper printing plate (the film which is etched for offset printing) is placed in the paper tray of the copier, now redesignated "film tray" for these procedures. An original copy of the document to be rendered noncopyable is placed on the copier platen. Adjustments to the copier are made as were done previously in the explanation of photocopier creation techniques, and a copy is made in black only onto the surface of the printing plate film. The plate-film is then etched, placed on an offset printing press and multiple copies are produced of the invention document. This is the most cost-expedient and first attempted method that we employed for making the invention. With monotone documents, it is extremely effective and derives from the critical, original discovery that was disclosed in '020 — that a photocopier cannot truly replicate its own copy of a document. Finally, an indirect gravure or intaglio plate making process may be used as depicted in Figure 7. A copy of an ^■ original image is made and entered into the memory of a laser copier. The laser memory copy output, which is digital, is intercepted and converted to analogue signals in order to activate a laser photo-electric cell which redigitizes the original memory of the copy and exposes the light sensitive coating on a gravure or steel engraving plate. After development and etching, the printing plate is produced of which multiple copies bearing the invention can be printed on a gravure or intaglio printing press. As may be readily surmised, most of the methodology aforementioned is known to those of ordinary skill in the art. It has been disclosed herein simply because these are the methods which have proven most effective to the instant inventors in the realization of security documents bearing the invention with its various enhancements.

Use of and practice with the herein disclosed invention, in all or but one or two of its aspects, will provide an effective means for controlling counterfeiting of valuable security or face value documents. Routineers in the printing field have the capability of adding many variations to the principles and techniques discussed herein. It is the intention of the instant inventors that such be done freely; but they reserve to themselves that body of right secured by the hereinafter appended claims and equivalent practice(s) thereof.

Claims

What is claimed is:

1. A document comprising print stuff on a suitable matte characterizing special images printed with media thereon which are placed in patterns to at least partially misregister with a photocopier regular copy protocol, said images further comprising lineation indicia of various lengths and curvature with each indicium of said indicia comprising a color, including black and white, and said, patterns generally varying with respect to their lineation pitch, position or directional placement on said document, whereby a photocopier that is surveying said document by a regular copying protocol copies only some portions of said images because said placement of indicia patternwise partially misregister with the copier protocol and omissions and moire distortion occurs in a resultant copy of said document.

2. The media of Claim 1 further characterizing cured, glittering resin as one medium which effects flare when illuminated.

3. The suitable matte of Claim 1 further characterizing a tonally graduated matte.

4. The lineation indicia of Claim 1 further characterizing irregularly spaced, shaped and sized indicia which effect flare when illuminated.

5. The suitable matte of Claim 1 further characterizing dry preprinted pressings thereover.

6. The method of making a document that is not accurately couterfeitable by photocopy or photography comprising placing imagery on a suitable matte and characterized by the steps of: scanning an original image using photo-optical scanning means; storing in memory means information scanned in the first step; operating alteration means in order to enhance the copy of the original image stored in memory means; and outputting the altered memory copy of said original image.

7. The method of Claim 6 further comprising storing in the memory means one or more line screen patterns.

8. The method of Claim 6 further including said outputting step and characterizing outputting to laser means and thereafter laser illuminating, by said outputting, a photo¬ sensitive printing plate.

9. The method of Claim 7 wherein said outputting is directed to a printer and further characterizing printing by said printer a copy of said original image which has been enhanced by the preceeding step and thereafter using an enhanced copy of said orignal image in a conventional printing process for producing nonreplicable documents.

10. The method of Claim 6 wherein said scanning means is a photocopier containing the memory means and said outputting is producing a photocopier copy of said original image and further characterizing over/underprinting of the photocopier copy with a clear medium which is varnish.