MXPA94004371A - Variable data clear mark imaging - Google Patents

Abstract

A security document is produced from a paper substrate having invisible hydrophobic toner blended into the paper. The clear toner is produced by milling and classifying a polyester resin, mixing it with silica flowing agent, and then electrostatically imaging the toner onto the paper substrate, as a spot that can be overprinted, or preferably as indicia that is not visible to the naked eye or color copiers. An infra-red absorbing or UV responsive dye may be added to the toner so that it is visible under infra-red/ultraviolet light respectively, or without that dye it is not visible when eliminated by light of any wavelength. When applied to the paper the toner is snow white, but after infra-red heat fusing it blends into the paper and is substantially invisible. The security indicia is easily made visible by passing a conventional marker nib over it, or other mechanism for applying a water based low concentrate colored ink which is readily absorbed by the surrounding paper, but not by the hydrophobic security indicia.

Description

IMAGING THE IMAGE OF A CLEAR VARIABLE DATA MARK BACKGROUND AND SUMMARY OF THE INVENTION There are many circumstances in which it is desirable to print indications or invisible areas on a paper substrate and then make these areas invisible in a simple and easy way. Such a need exists in the production of educational forms, but is particularly useful in the area of security documents. In particular, with the introduction of modern color copiers, counterfeiters, amateurs and professionals, can reproduce any kind of valuable documents, such as admission tickets, passes, coupons, certificates, bank checks, lottery tickets, money orders and Similar. Many businesses and agencies suffer substantial losses as a result of the production and distribution of false documents, however most can not justify the cost of conventionally available security devices to protect against this type of fraud. In accordance with the present invention, a method and product are provided in which essentially invisible indications or zones are easily applied, using conventional equipment, to a paper substrate. Using a simple conventional embossing marker or similar, one can easily test the document on authenticity or use the document in another way, making the hidden indications clearly visible. Since the invention uses very simple components, conventional equipment and simple techniques, a security document can be produced, such as a ticket, bank check, stock certificate, coupons or the like, almost without increase in cost, compared to a unprotected document. The basic aspect of the present invention is the use of a clear toner (toner), which can form an image electrostatically on a piece of paper, such as by the use of a double roller, electrostatic fluidized bed applicator. The toner, which is simple to manufacture, is initially applied to paper, in its virgin form, as a snow-white deposit, which has a clear contrast to the surface of the paper (even if it is white). However, after the toner is heated to melt, as by a conventional infrared heat melter, it melts into the paper fibers and becomes clear, so that it is essentially invisible to the naked eye, when illuminated at any length of light wave (unless a particular dye is added to it to make it intentionally visible when illuminated by infrared or UV light). The applied toner is hydrophobic, so that when a low concentration, water-based ink, such as a color felt tip marker, or the like, is applied to the paper substrate to the toner area that forms the image , the toner itself repels the marker, but the surrounding paper absorbs it quickly, so that the toner is clearly visible as a "negative" image. This allows, for example, an entrepreneur of ski jump functions, to easily and simply check the authenticity of the documents presented, such as the tickets for the function. The person checking the tickets needs to use only a conventional marker and know where to mark the ticket presented to make the security signs visible. Clear safety signals can not be reproduced successfully yet by a modern color copier. In accordance with one aspect of the present invention, a method is provided for providing and using safety signals on a paper substrate, which uses a substantially clear hydrophobic toner, the method comprising the following steps: (a) loading and applying the toner in the form of safety instructions to the paper substrate; (b) heat melt the toner, so that it is mixed inside the paper and becomes substantially invisible to the naked eye and to color copiers, regardless of the wavelength of the light directed on it; and (c) when it is convenient to see the signals, apply a water-based solvent system, which has a different color than the paper substrate, to the paper substrate on the toner, the paper surrounding the toner signals absorb the solvent, while not the toner signals, making these toner signals visible. Step (a) is practiced by the toner image formation on paper, in electrostatic form, for example using ionographic, laser and ion deposition techniques, and step (b) is typically practiced by infrared heat fusion. Step (a) is further practiced using a toner based on polyester resin, which has been milled and sized so that the particle size is very uniform, and mixed with a silica flow agent. The toner can form variable images on the paper and also visible indications that correspond to the invisible indications can also form images variablely on the paper. Alternatively, it can be overprinted, or overcoated, for example by applying a sheet thereon. When it is convenient to make the indications visible at certain wavelengths of light, a dye responsive to UV light or a dye that absorbs infrared light can be added to the toner. The invention also considers a security document obtained by the method described above. According to another aspect of the present invention, a security document is provided, which comprises: a substantially paper substrate; and images of indications on the substrate, comprising a hydrophobic toner in admixture with the paper substrate, so that it is substantially invisible to the naked eye and to color copiers, when illuminated with ambient light. The invention also comprises another type of security document, particularly useful for obtaining lottery tickets or the like, which have a different receptivity to inks and overprinted overlays for considerations of wear or permanence of image. The security document, according to this aspect of the invention, comprises: a paper substrate, a hydrophobic toner image zone on and in mixture with the paper substrate, so that it is substantially invisible to the naked eye and to copiers color, when illuminated with ambient light. And, a coating or printing on the area.

The invention also contemplates a method for treating a substrate, which comprises the following steps: (a) producing a clear toner by grinding a polyester resin at an average particle size of about 15 microns and classifying the resin to reduce the particles less than about 5 microns to less than 10% of the total particle distribution and mixing the ground and classified particles with a silica flow agent and intimately mixing them together; (b) electrostatically forming images of the toner on a paper substrate; and (c) heat melting the toner, so that it is mixed within the paper substrate and becomes substantially invisible to the naked eye and to color copiers when illuminated with ambient light. Step (b) is typically practiced by forming the image of the toner on the surface as indications that can be read by a human or machine, and there is typically the additional step of forming a visible image of the toner on the substrate, which corresponds to the invisible image of the toner there, by the practice of stage (b). It is a primary object of the present invention to provide a simple and efficient technique for producing documents having invisible signals or areas, which are made easily visible, in particular for security document applications. These and other objects of the invention will become clear from an inspection of the detailed description of the invention and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram of tables illustrating the steps of the exemplary method, according to the method of the present invention; Figures 2 to 4 are perspective views of exemplary security documents, in accordance with the present invention; and Figure 5 is a perspective illustration, greatly amplified, of a security document, in accordance with the present invention, showing a conventional embossing marker moving over the security signals printed thereon, to make these signals visible . DETAILED DESCRIPTION OF THE DRAWINGS The exemplary method for obtaining and using a security document, or a similar document, with indications or invisible areas, which are easily made visible, is illustrated schematically in Figure 1. In the exemplary embodiment illustrated in FIG. Figure 1, a polyester resin is operated in step 11 by grinding it (for example by milling it by choro) to a predetermined average particle size, and then going on to sorting step 12, where it is classified to reduce the number of particles under a certain size. Then, in step 13, a flow agent is added, and this flow agent and the resin are intimately mixed in step 14 to produce a "toner" (tint). The toner thus produced will be clear when it is illuminated by all the wavelengths of light, after melting by heat, but, when convenient, it becomes visible when it is illuminated by certain wavelengths of light, a conventional dye that absorbs infrared light or a conventional dye responsive to UV light, can be added, as indicated by the line in dashes 15 in Figure 1. When you add the dye that absorbs the infrared light, then the indications printed with the toner They are visible when illuminated with infrared light and when a responsive dye is added to the UV light, the indications printed with the toner fluoresce when illuminated with UV light. While a wide variety of resins, flow agents and techniques can be used, a particularly advantageous technique for the practice of steps 11 to 14 of the invention is as follows: A polyester resin (such as ATLAC 382 E) , by Reichold) was jet-milled to an average particle size of about 15 microns and then classified to reduce particles smaller than about 5 microns to less than about 10% of the total distribution. The resin powder produced was then mixed with 0.75% by weight of a smoked silica flow agent., such as Cabot TS-530 or its equivalent, and mixed in a high-speed mixer, such as a Henschell or Omni. The toner, thus produced, is readily available for use in a conventional ionographic printing engine, Midax 300, and can form an image on a substrate of snow white paper, and then becomes clear after melting by heat. After the toner is produced in step 14, it forms an electrostatic image on a substrate, as schematically indicated at 16 in Figure 1. Any of a wide variety of electrostatic image forming techniques and equipment can be used. For example, ionographic, laser and ion deposition forming techniques are useful, as well as their corresponding printing engines, such as a Midax 300 ionographic printing engine. for the ionographic techniques. When an ionographic printing engine is used, the toner is applied with a double roll, fluidized electrostatic bed applicator, as shown in the patent application, also pending, Serial No. 07 / 639,360, filed on 8 January 1991 (Proxy No. 263-511); 90-42) whose description is incorporated herein by reference. Simultaneously with the electrostatic image formation of the light toner, as indicated in step 16, or before that image formation, the paper can also form variable images with visible indications (using a visible toner), as schematically indicated in FIG. In any case, after the image formation of the clear toner in step 16, the toner is activated by heat to melt inside the paper, making it clear. When initially applied to paper, the toner is white as snow, but when heated with infrared light, melting and subsequent melting of the toner causes it to become substantially invisible to the naked eye, and all color copiers currently in the trade, which include those of Canon (for example Canon's laser copier) and Xerox. The heating / melting step is illustrated in Table 18 in Figure 1. After melting the toner, as indicated at 18 in Figure 1, the toner may optionally be overprinted or overcoated. For example, when the toner is applied in the form of a zone, it can be overprinted with visible indications, schematically illustrated by step 19 in Figure 1. This is particularly useful for lottery and other games, where the zone It can be of different receptivity to the overprint and coatings for considerations of spent or imaging. Alternatively, the visible indications can be overprinted on the indications of the light toner. Finally, as indicated in step 20, when it is convenient to make the invisible indications visible, step 20 is practiced. In step 20, a solvent system of water-based color is applied to the toner. The colored solvent is easily absorbed by the surrounding paper, but is repelled by the invisible hydrophobic toner applied in step 16, thus making it easily visible to the naked eye as a "negative" image shape. A wide variety of different types of solvent systems may be used, but preferably they are water-based, low-concentration ink-based, water-based solvent systems, such as are provided in conventional embossing markings. Examples of numerous commercially available enhancement markers, which have proven to be functional and suitable for this purpose, are the purple and blue markers • Pilot Spotlighter, the "Magic Marker Brand" fluorescent green markers, the color markers yellow and blue fluorescent "BIC Brightliner", the black and blue markers "BIC Ultrafine Marking Pen" and the red and black markers "Papermate Flair Pen".

An exemplary security document, produced using the basic method illustrated in Figure 1, is shown schematically at 23 in Figure 2. The security document includes a paper substrate 24, with various visible indications thereon, such as indication "Pay to a" and indication 26 of the amount of dollars, produced on the substrate 24 with a conventional visible toner. Also in this particular embodiment are provided alpha-numeric visible indications 27, and invisible indications, according to the invention - shown schematically in dashed lines at 28 in Figure 2 (shown in dashed lines because it is impossible to illustrate them) otherwise, since they are invisible) - which correspond to indications 27, are also supplied. In the use of security document 23 - which is typically a bank check or money order - in order to prove its authenticity, all that needs to be done is to rub a "magic" marker of a different color distinctly than the substrate. paper 24 (for example not white, and preferably not yellow) on the left bottom area of the paper substrate 24, which will make the indications 28 visible. If the visible indications 28 are not present, then the document is a fraud, or if, for some reason, it illustrates different indications of those 27, it is also fraudulent.

Figure 3 schematically illustrates another security document 30, according to the invention, this time in the form of a lottery or game ticket. Again a paper substrate 31 (for example a substantially white paper) has conventional visible indications 32 printed and in this embodiment a zone or area 33 of invisible toner, according to the present invention. The indications 34 can be overprinted in the area 33 and this zone 33 can also be applied over the previously existing visible indications on the substrate 31, so that the zone 33 can comprise a rub-separated area, or the supply for a different printing receptivity of the indications 34 or the like. Figure 4 illustrates another exemplary security document 37, according to the invention, this time in the form, schematically, of a stock certificate. Again a paper substrate 38 has conventional visible indications 39 printed, as well as the overprint 40 in the invisible alpha-numeric indications 41, which have been applied according to the invention. Figure 5 schematically illustrates how the invisible indications, according to the invention, become visible, in this particular case schematically illustrated with respect to a ski jump ticket or other spectacle, comprising a substrate 44 of white paper having indications invisible 46 formed on it (for example letters that say "THIS IS A VALID TICKET"). The color area 47 that makes the previously invisible indications of toner 46 visible is a low concentration, water-based ink (for example, blue, as shown in Figure 5), which has been applied by the tip 48 of a conventional highlight marker 49, such as a "BIC Brightliner" marker. Indications 46 are clearly visible as a negative image. It will thus be seen that, in accordance with the present invention, a simple yet effective method of producing and using security documents and the security documents themselves has been provided, which provides excellent security and is still easy to prove in its authenticity. While the present invention has been shown and described in what is currently conceived as the most practical and preferred embodiment, it will be apparent to those of ordinary skill in the art that many modifications may be made within the scope of the invention, this scope being according to the broadest interpretation of the appended claims, so as to cover all equivalent methods and products.

Claims (25)

WHAT IS CLAIMED IS:

1. A method for supplying and using safety signals on a paper substrate, which uses a substantially clear, hydrophobic toner (tint), this method comprises the steps of: (a) charging and applying the toner in the form of safety signals to the paper substrate; (b) heat melting the toner, so that it is mixed in the paper and becomes substantially invisible to the naked eye and to color copiers, regardless of the wavelength of the light directed thereon; Y (c) when it is desired to see the signals, apply a water-based solvent system, which has a different color distinctly than the paper substrate, to the paper substrate on the toner, the paper surrounding the toner signals absorb the solvent , while the toner signals are not, making the toner signals visible.

2. A method according to claim 1, wherein stage (a) is practiced by toner image formation on paper, using an image-forming technique selected from the group consisting essentially of ionographic imaging techniques, laser and ion deposit.

A method according to claim 1, in which step (a) is practiced by electrostatic image formation 4.

A method according to claim 3, wherein step (b) is practiced by infrared heat fusion .

A method according to claim 1, wherein step (a) is carried out by charging and applying a toner based on polyester resin with a silica flow agent, which forms a snow white image on the paper.

6. A method according to claim 1, wherein step (c) is practiced by moving an applicator of a marker having a non-white, low-concentration, water-based ink on the toner signals.

7. A method according to claim 1, wherein the step (a) is practiced by forming variable images on the paper, which correspond to the image signals visible on the paper.

A method according to claim 1, wherein the step (a) is practiced by forming signal images variablely on the paper, and comprises the additional step of forming signal images variablely on the invisible signals.

9. A security document, which comprises: a substantially paper substrate; and signal images on the substrate, comprising a hydrophobic toner in admixture on the paper substrate, so that it is substantially invisible to the naked eye and to color copiers, when illuminated with ambient light.

10. A security document according to claim 9, in which the toner includes a dye that absorbs infrared light, so that the signals are visible when illuminated with infrared light.

11. A security document according to claim 9, in which the toner includes a dye responsive to UV light, so that the signals fluoresce when illuminated with UV light.

12. A security document, according to claim 9, further comprising visible signals, corresponding to the invisible signals formed on the substrate.

13. A security document according to claim 9, further comprising visible over-printed signals on the invisible signals.

14. A security document according to claim 9, wherein the toner is a polyester resin, having a silica flow agent.

15. A security document according to claim 9, in which the substrate is substantially a white paper, and further comprises a water-based solvent system, of distinctly non-white color, arranged over the signals and the immediately adjacent substrate, the system of Non-white colored solvents are absorbed by the substrate but not by the toner signals, in order to make the toner signals visible.

16. A security document, which includes: a paper substrate; a zone of hydrophobic toner that forms images on and in mixture with the paper substrate, so that it is substantially invisible to the naked eye and to color copiers, when it is illuminated with ambient light; and an over-coating or over-printing on the area.

17. A security document according to claim 16, wherein the over-printing or over-coating is selected from the group consisting essentially of overprinted inks and sheet coatings.

18. A security document according to claim 16, wherein the hydrophobic toner comprises a polyester resin having a silica flow agent.

19. A method for treating a substrate, comprising the steps of: (a) producing a clear toner, grinding a polyester resin to an average particle size of about 15 microns and classifying the resin to reduce the smaller particles of about 5 microns to less than about 10% of the total particle distribution, and mixing the ground and classified particles with a silica flow agent, and mixing intimately with each other; (b) electrostatically imagering the toner on the paper substrate; and (c) heat-melting the toner, so that it is mixed on the paper substrate and becomes substantially invisible to the naked eye and to color copiers, when illuminated with ambient light.

20. A method according to claim 19, wherein step (a) is further practiced by mixing in the toner a dye, selected from the group consisting essentially of dye responsive to UV light and dye that absorbs infrared light.

21. A method according to claim 19, wherein stage (b) is practiced by ionographic image formation.

22. A method according to claim 19, wherein step (c) is practiced by the fusion of infrared heat.

23. A method according to claim 19, wherein step (b) is practiced by the image formation of the toner on the substrate as signals that can be read by a human or a machine.

24. A method according to claim 23, comprising the additional step of forming a visible image of the toner on the substrate, which corresponds to the invisible image of the toner formed by the practice of step (b).

25. A paper substrate safety document, produced by the method comprising the steps of: (a) loading and applying the hydrophobic toner in the form of safety signals to the paper substrate; (b) heat melting the toner, so that it is mixed on the paper and substantially invisible to the naked eye and to color copiers, regardless of the wavelength of the light directed thereon; and (c) apply a water-based solvent system, which has a different color than the paper substrate, to the paper substrate on the toner, the paper surrounding the toner signals absorb the solvent, while the toner signals do not , making the toner signals visible. EXTRACT OF THE INVENTION A security document is produced from a paper substrate having an invisible hydro-phobic "toner" (tint) in admixture with the paper. The clear toner is produced by grinding and sorting a polyester resin, mixing it with a silica flow agent and then electrostatically forming the image of the toner on the paper substrate, as an area that can be overprinted, or preferably as an index that is not visible to the naked eye or to color copiers. A dye can be added to the toner that absorbs infrared light or is responsive to UV light, so that it is visible under infrared / ultraviolet light, or without the dye being visible when it is removed by light of any length. wave. When applied to paper, the toner is white as snow, but after melting by the heat of infrared light, it mixes on the paper and is substantially invisible. The safety instructions are made easily visible by passing a conventional marker tip or other mechanism to apply a low concentration, water-based color ink, which is easily absorbed by the surrounding paper, but not by the hydrophobic safety indications.