DOCUMENT BEARING CHARACTERISTIC INK-PRINTED INDICIA JUXTAPOSED WITH CORRESPONDING CHARACTERISTIC SYNTHETIC WATERMARK AND METHOD FOR PRODUCING SAME

Abstract: A document security system is provided by providing each document with a synthetic watermark, for instance using the process, compositions and apparatus disclosed in the aforementioned U.S. patent of Norris, et al and, within the perimeter of at least one of the symbols which is provided by the synthetic watermark, an identical complementary or otherwise corresponding symbol is printed using ink, paint, dye, stain or similarly contrastingly pigmented substance so as to create, in combination with the synthetic watermark a juxtaposition that can be looked-for as evidence that the doc­ ument is genuine and its serial number unaltered.

Description: BACKGROUND OF THE INVENTION Many documents have monetary value. Some are even recognized to be privately issued substitutes for money-Traveler's Checks, money orders and stock certificates to name but a few. Also, other documents have great value to show origin, titles, personal identification, etc., motor vehicle certificates of origin, birth certificates and Social Security cards are but a few examples. The US patent of Norris, et al., 3,985,927, issued October 12 1976 (and corresponding British Patent Specification No 1465029 Nekoosa) discloses compositions and a method for producing chemical watermarks in finished paper products, the watermarks being produced by applying to the surface of the paper a chemical composition, which, after suitable radiation treatment to render its effect permanent replicates the appearance of a conventional mechanical watermark, without detracting from the finishing, use and keeping-quality of a document made from the paper. In contrast to printing, a chemical watermark is colourless and cannot be dissolved from the paper. It is detected primarily as a pattern of difference in translucence of the paper. The entire disclosure of this patent of Norris, et al is incorporated herein by reference, inasmuch as it further illuminates the state of the prior art, as well as teaches ways, means and compositions for applying chemical watermarks to paper. Similarly British Specification No 1489084 (Tullis Russell) discloses a method of producing a simulated watermark in a paper sheet wherein the sheet is impregnated by a transparentising composition which is itself fluent and which is polymerisable upon being activated by radiation to yield an insoluble resin matrix having a refractive index approximating to that of the paper and the composition is cured in situ by irradiating the sheet with activating radiation. Other US patents disclosing useful ways and means for synthetically watermarking paper, using synthetic resins which, in contrast to those of Norris and Tullis Russell, do not require application of in Situ ultraviolet light or like radiation for curing, are shown and described in the following US patents, the entire disclosures of which are incorporated herein by reference: Vaurio 3.085,898 16 Apr. 1963 Vaurio 3,140,959 14 Jul. 1964 Skofronick et al. 3,293,062 20 Dec. 1966 Skofronick 3,441,427 29 Apr. 1969 Skofronick 3,443,979 13 May 1969 Skofronick 3,464,841 2 Sep 1969 Skofronick 3,486,923 30 Dec 1969 Also French Specification No 2023814 (British Specification No 1286309) describes a security document bearing a stereoscopic picture of which at least one half of the picture being a true watermark or an artificial watermark. UK Patent Specification No 2159463 describes continuous computer stationery having a watermark with a conventional ink imprinting in register with the watermark. Specification DE B 2901150 (British Specification No 2039466) describes an identification card bearing a hallmark formed by means of partially overlapping colour coatings on a monochromatic or monochromatically printed substrate. British Specification No 2076337 describes an identification card having at least two layers laminated together with at least two partly overlapping monochromatic printed images which overlap printed on the layers. The term "synthetic watermark" is used herein to denote a watermark which is produced in situ on paper mainly with the aid of a chemical and radiation process, in contrast to its being created in the paper by mechanical means as a pattern of local thickness discontinuity during manufacture of the paper from pulped fibers. By means of the method of producing the watermark in situ with the aid of the chemical and radiation process a more permanent watermark less capable of being tampered with than heretofore is produced. The term "serial number " is used herein to denote the unique string of indicia (characters) which is applied to a document in order to distinguish that document, both from ones that are otherwise identical but have applied indica series which differ as to at least one indicium (character) and from ones which are not genuine. Use of the term is not intended to imply that the string of indicia consists either partly or wholly of numbers; in other words, a "serial number" as that term is used herein may include any combination of numbers, letters, punctuation marks and specialized symbols. Falling within this definition, in addition to conventional serial number, are amounts, names and combinations thereof. Summary of the Invention It is an object of the present invention to provide an improved series of documents printed on paper each being provided with a unique serial number and to a method of producing such series of documents. According to the present invention a series of documents printed on paper each being provided with a unique serial number includes; a first character 16 provided as a synthetic watermark field in which the relative translucence but not the colour of the paper is contrasted, and a second character 22 provided as an ink-imprinted field in which the colour of the paper is contrasted, characterised in that the first character comprises a first string of characters 16 prepared by applying to the surface of the paper a chemical composition which is subsequently treated by a radiation process to set the first string of characters 16 and in that the second character comprises a second string of characters and wherein at least one character in the synthetic watermark field 16 is provided to have a characteristic relative juxtaposition with at least one character in the ink-imprinted field 22 to at least partially surround a respective character in said ink-imprinted field. Also the invention concerns a method for providing each document of a series of paper documents with a serial number which includes at least one said character in at least one field is stepped in identity on successive documents in the series. In a preferred practice of the invention both a synthetic watermark serial number and a conventionally printed serial number are provided on each document in a set of documents. Each document is thus made to be different from all of the others in the set as well as from documents not in the set. In this preferred practice the synthetic watermark serial number is the same as, but is applied in a larger typeface than the conventionally printed serial number, with each character of the latter being centered within the corresponding character of the former. As a result, when held to the light a water mark "halo" appears around each of the conventionally printed characters, thus complicating the task of replicating, photocopying or altering the document. The principles of the invention will be further discussed with reference to the drawing wherein a preferred embodiment is shown. The specifics illustrated in the drawing intended to exemplify, rather than limit, aspects of the invention as defined in the claims. Brief Description of the Drawing Figure 1 is a diagrammatic flow sheet illustrating successive steps in the practice of preferred embodiment of the present invention; and Figure 2 is a diagrammatic representation of an examination of a sample of the product for genuineness and lack of alteration. Detailed Description By way of example, in Figure 1, the method of the invention is shown being carried out on a web comprising a series of successive paper documents at a stage of document manufacture, the web being conventionally advanced by engagement of tension pull rolls with the web. (Preferably, the opposite marginal series of holes which may later be used for advancing the web using conventional drive sprockets engaged therein are not formed in the web until a later stage, although they could be provided earlier and used at this stage for web advancement.) In practising the present invention in a preferred way, at a first station 10, a sheet or document of paper 12 in a series of such sheets or documents 14 is imprinted with a first string of characters 16, of which at least one preferably is different for each successive sheet in the series, so that the string of characters 16 imprinted on each sheet taken as a whole string provides a synthetic watermark field and is unique and thus capable of functioning as a serial number uniquely identifying that particular sheet. At this first station 10, the fluid material used for the imprinting is not like an ink, in the sense that it does not use a solution or suspension of pigment applied in a visible pattern which contrasts in colour, chroma, hue or brilliance with the colour of the paper substrate constituting the sheets or documents 14. Rather that fluid material is a composition which, when dried or cured, eg at a subsequent curing station 18, which may include the application of photons of a particular band of energy levels to constitute a radiation process and the application of air drying with or without added heat, causes the paper or document to sharply differ in degree of relative translucence where imprinted in comparison with its degree of translucence where not so imprinted. The pattern may either be one in which the imprinted characters, when a sheet of the paper is viewed from the front with strong back-lighting, constitute a regional pattern where the paper is more translucent than the non-imprinted remainder of the sheet, or partly more translucent and partly less translucent. The first string of characters 16 as illustrated in dashed lines in Figure 1, on successive sheets typically may show-up under strong back lighting as a series of successive segments eg which read, "..., * 6A, * 7A,, * 8B, * 9B, * 0B, * 1B,...". At a third station, 20, each sheet of paper is imprinted with a pigmented ink so that each bears a second string of characters 22, illustrated in full lines, of which at least one preferably is different for each successive sheet or document in the series, so that the string of characters 22 imprinted on each sheet taken as a whole string comprises an ink impregnated field which is unique and thus capable of functioning as a serial number for uniquely identifying that particular sheet or document. Although it is preferred that both strings of characters on each document be printed on the same line, the principles of the invention can be practised even if the two strings of characters are provided on lines which adjoin one another or bear some other predetermined relationship. At least one of the characters of the first string 16 applied and developed as a synthetic watermark at stations 10, 18 is juxtaposed with at least one of the characters of the second string 22 applied as a contrasting-colour serial number at station 20. For instance the corresponding two characters may be alike and superimposed so that one of them skirts the perimeter of the other about all of or a substantial part of that perimeter. In the instance depicted, the contrasting color-imprinted second series has a segment which reads "... *1 E, *0 D, *9 D, *8 D, *7 D, *6 D...". In this example, the typefont used for producing the synthetic watermark serial number is similar to but larger-charactered than that used for producing the contrasting color-imprinted serial number, so that if the resulting documents D are held up to the light, they are seen to be successively read "...*1BE, *0BD, *9BD, *8BD, *7AD, *6AD,...", in which the characters "*" of the synthetic watermark-type first strings appear to halo 26 (border, permetrically surround) like characters "*" 28 imprinted with ink in the second series. In this example, the comparable situation is true for the corresponding second character, A, in each of the two strings. However, it is not true for the third character "...A, A, B, B, B, B...", which is present only in the first strings 16, but not in the second string 22, where the corresponding space is left non-imprinted, i.e. blank. Nor is it true for the fourth character position, which in the first strings 16 is left blank, but in the second strings 22 is imprinted with a character, e.g. "... E, D, D, D, D, D, E...". Thus, although the process and compositions and apparatus used for imprinting each of the documents with each of its two strings of characters are known, the combination, if performed in accordance with the principles of the present invention easily provides a unique system for readily not only keeping track of the documents by serial number, but also for conveniently examining them for lack of alteration, and for genuineness. For instance, upon strongly back-lighting a document D (Figure 2), the examiner can conveniently look for the fact that the "*" in the first character position of the synthetic watermark "halos" the "*" of the ink-printed serial number, for the fact that the "...1, 0, 9, 8, 7, 6,..." in the second character position of the synthetic watermark "halos" the respective "...1, 0, 9, 8, 7, 6,..." in the second character position of the ink-printed serial number, for the fact that the synthetic watermark character "...,B, B, B, B, A, A,..." in the third character position corresponds to a no imprinted space in the third character position of the ink-printed serial number, and for the fact that no synthetic watermark character appears in the fourth position, where the ink imprinted serial number has a character "...,E, D, D, D, D, D,..." In looking at any one document D (Figure 2), the examiner can be looking for completeness of the serial number (e.g. that it reads *6AD"), the examiner can be looking for lack of alteration of the serial number (e.g. that the "*6" of the synthetic watermark both "halos" an "*6" of the ink-imprinted serial number) and that the juxtaposition is characteristic of a genuine one (e.g. that one *6 is precisely centered on the other, that both are of the same type face and that the halo extends one-half millimeter beyond the respective printed characters, this example of juxtaposition and relative characteristics being only one among many which could be adopted by the designer and issuer of the genuine documents D), and the examiner can be looking for the side-by-side juxtaposition of synthetic and ink-imprinted characters, rather than their juxtaposition (e.g. that no ink-imprinted character appears in the third character position, but a synthetic watermark character does, and vice versa as to the fourth character position, these being made as checks against spurious addition or deletion of characters by a counterfeiter who is unwitting of the code adopted for the serial number printing process). Clearly, the examiner which performs the examination referred to in connection with the above discussion can be but need not be a human, in that the system provided by the invention lends itself easily to rapid and reliable routine examination of large numbers of documents by light-sensitive electronic instruments, e.g. sets of photo-electric cells in sensor circuits programmed to look for and distinguish presence and absence of correspondence with characteristic features of the particular code adopted. Registration systems used in printing. processes are well-known and may be used in a conventional manner for providing proper juxtaposition of the two strings of characters on each document. Because these techniques are so well known in the trade, it is believed unnecessary to describe them in further detail. Various, conventional printing processes may be used for applying the two character strings using presses which are sheet fed or web fed, and which apply the synthetic watermark imprinting fluid of the first character string and the ink of the second character string by stamping, rotary printing, felt printing, ink jet printing, ribbon-impact printing or the like. Likewise, the devices used for stepping-up the serial number from document to document may be any convenient ones of such devices as are presently commercially available for serial numbering of documents, e.g. ones in which the serial numbering is stepped manually by rotating endless rubber mats of reverse characters as on a hand-operated date-stamper, ones in which the serial number is automatically mechanically stepped using a series of cams, pawls, ratchets and cam followers operating endless wheels or bands of reverse characters, or ones in which serial number stepping is electronically programmed, e.g. into the controller for a daisy wheel or ink-jet printer. It should now be apparent that the document bearing characteristic ink-printed indicia juxtaposed with corresponding characteristic synthetic watermark and method for producing same as described hereinabove, possess each of the attributes set forth in the specification under the heading "Summary of the Invention" hereinbefore. Because it can be modified to some extent without departing from the principles thereof as they have been outlined and explained in this specification, the present invention should be understood as encompassing all such modifications as are within the scope and spirit of the following claims.

Claims: 1. A series of documents (12) printed on paper, each being provided with a unique serial number, which includes: a first character (16) provided as a synthetic watermark field in which the relative translucence but not the colour of the paper is contrasted,and a second character (22) provided as an ink-imprinted field in which the colour of the paper is contrasted, characterised in that the first character comprises a first string of characters (16) prepared by applying to the surface of the paper a chemical composition which is subsequently treated by a radiation process to set the first string of characters (16) and in that the second character comprises a second string of characters and wherein at least one character in the synthetic watermark field (16) is provided to have a characteristic relative juxtaposition with at least one character in the ink-imprinted field (22) to at least partially surround a respective character in said ink imprinted field. 2. The series of documents according to claim 1, wherein: at least one character of the string of characters in the synthetic watermark field 16 which at least partially surrounds at least one character of the second string of characters in the ink-imprinted field (22) is a replication of the same character, so that the at least one character in the ink-imprinted field (22) is haloed by the character in the synthetic watermark field (16). 3. The series of documents according to claim 1, wherein: the at least one character of the string of characters in the synthetic watermark field (16) lies non-overlappingly characteristically adjacent at least one character of the second string of characters in the ink-imprinted field (22). 4. The series of documents according to any one of claims 1, 2 or 3, wherein: on each document the strings of characters (16), (22) are provided in a line common to both kinds of characters (16), (22). 5. The document according to any one of the preceding claims, wherein: at least one character (16), (22), in at least one of the fields is provided in a gap in the corresponding other field. 6. A method for providing each document (12) of a series of paper documents (14) with a serial number, according to claim 1 which includes: printing on each document a first character (16) as a synthetic watermark field in which relative translucence but not of the colour of the paper is contrasted: and printing on each document a second character (22) as an ink-imprinted field in which the colour of the paper is contrasted, characterised in that the first character comprises a first string of characters (16) prepared by applying to the surface of the paper a chemical composition which is subsequently treated by a radiation process (18) to set the first string of characters (16) and in that the second character comprises a second string of characters and wherein at least one character in said synthetic watermark filed (16) is provided to have a characteristic relative juxtaposition with at least one character in said ink-imprinted field (22) at least partially to surround a at least one respective character in the ink-imprinted field (22). 7. The method according to claim 6 characterised in that at least one said character in at least one field is stepped in identity on successive documents in the series. 8. The method according to claim 7 having in combination therewith any of the features according to any one of claims 2 to 5.

Inventors: VAN MALDERGHEM, EDMUND G.
Applicants: MOORE BUSINESS FORMS, INC.
Application year: 1987
Main classification: B41M3
IPC codes: B41M1, B41M3, B41J25, B42D15