JP2017100331A - Forgery preventive printed matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed matter that exhibits an effect of changing images at a low cost by using a black color printing unit for printing normal characters without using exclusive two printing units.SOLUTION: The printed matter includes a printed image having a hue different from that of a base material on at least a part of the base material. The printed image comprises superposed images of a first image formed of a brilliant ink and a second image having a latent image part formed of a black ink showing the same hue as that of the brilliant ink under diffused reflection light, representing second significant information. The first image is composed of an information part and a latent image camouflage part having a density that is reversal of the density of the latent image part, segmented by a density difference. The second image is composed of the latent image part and a background part, segmented by a density difference. Each density of the information part and the latent image camouflage part of the first image is formed resulting from subtraction of the density of the second image from the density of the first significant information represented by the printed image under diffused reflection light, overlapping the second image at the same position.SELECTED DRAWING: Figure 1

Description

  In the field of security printed matter such as banknotes, passports, securities, identification cards, cards, and passports that require an anti-counterfeit effect, the present invention differs depending on the angle of light incident on an observable image. This is related to anti-counterfeit printed matter that changes.

  With recent developments in digital devices such as scanners, printers, and color copiers, it has become possible to easily produce elaborate copies of precious printed matter. As one of the anti-counterfeiting techniques for preventing such duplication and counterfeiting, there are many ones to which an optical security element typified by a hologram that changes an image depending on a printed matter or an observation angle has been attached.

  However, unlike conventional anti-counterfeiting technology, which is formed by printing with ink, holograms are formed using complex manufacturing processes and special materials, making them more difficult to manufacture compared to conventional anti-counterfeit prints. It takes time and is extremely expensive. Therefore, special light-reflecting powders such as metal ink, interference mica, oxidized flake mica, pigment-coated aluminum flakes, and optically changing flakes are blended in inks and paints, By using a complicated halftone dot configuration, forgery prevention printed matter that can be formed by a general printing method that realizes an image change similar to a hologram has appeared.

  While the applicant uses general and relatively inexpensive materials and simple printing means, the information recognized by the human eye at a specific part in the printed material at a specific observation angle is the observation angle. Have already filed inventions related to the information carrier for forgery prevention that changes to completely different information (for example, Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5). reference).

Japanese Patent No. 3398758 Japanese Patent No. 4604209 Japanese Patent No. 5358819 Japanese Patent No. 5245102 Japanese Patent No. 5360725

  Regarding the technique of Patent Document 1, since the luster material constituting the first print image and the color material constituting the second print image are different in hue, they are originally visually recognized in the observation under diffuse reflection light. There is a problem that the second print image that should not be seen, and the second print image is composed of a sparse area ratio and is formed on the first print image formed with a high area ratio. Due to the superposed configuration, there is a problem that the visibility of the second printed image that appears under regular reflection light is low.

  The techniques described in Patent Document 2 and Patent Document 3 are techniques for forming an anti-counterfeit printed material by superimposing a glittering material and transparent ink. Unlike the technique of Patent Document 1 using a color material for forming a latent image. Since the ink that forms the latent image is transparent, it is not necessary to adjust the color in the first place, and the latent image is not visualized under diffuse reflected light, and it has excellent switchability of the image. However, since transparent ink that cannot be visually observed is used, there is a problem that it is difficult to control the print quality at the time of manufacture.

  As a countermeasure for this, use transparent light-emitting ink that is a mixture of transparent ink and UV-excited light-emitting pigment, and irradiate UV light during printing to determine whether the transparent ink is printed without problems. Was common. However, when such measures are used, quality control at the time of manufacture is possible, but on the other hand, the structure of the latent image can be easily grasped by looking at the luminescent image that appears during UV irradiation. May give a clue to the structure of the anti-counterfeiting technology to the user, and there has been a problem regarding resistance to forgery.

  Furthermore, the technology described in Patent Document 4 is a technology that realizes an image change effect by forming two images each using a glittering material and a colored ink of the same color as the glittering material as a pair ink. Each image composed of ink is required to be printed with the highest degree of difficulty called `` tweeping '' that fits so that they do not overlap each other, and if a slight misalignment occurs, the latent image is visualized. Therefore, the anti-counterfeiting effect is very high, but there is a problem that a high-precision printing machine and a skilled operator are necessary for manufacturing.

  The technique described in Patent Document 5 is a technique related to the image line structure of the anti-counterfeiting technique that can obtain various effects by changing the combination of the functionality of the ink. There is a technology that realizes an image change effect under reflected light. Although the anti-counterfeiting effect of this technique was very high, the colored ink paired with the glitter ink had to be lighter (lower density) than the glitter ink. Because of the lightness of this ink, it is difficult to divert it to other parts of the printed matter, and it was necessary to use two colors of ink exclusively for forming the anti-counterfeiting technology.

  This is the same for the other techniques described in Patent Documents 1 to 4, and two colors of ink are essential for the formation of the anti-counterfeiting technique. Anti-counterfeiting technology is not actually used alone, but it forms a part of the printed matter together with various design elements such as tint block, scallop, portrait and characters. If a large number of inks are used solely for technology formation, it will be appreciated that the number of inks that can be used for other design elements is limited.

  If a printed product is printed on a four-color printing machine (four-cylinder printing machine), if two printing units are occupied in forming the anti-counterfeiting technology, printing of design elements other than the anti-counterfeiting technology is possible. Only the remaining two print units can be used, and as a result, the other design elements have to cover only two colors, which greatly restricts the color design of the entire printed matter. As described above, the prior art requires two colors of ink exclusively, and as a result, there is a problem that restrictions on the color design of the total printed matter increase.

  The present invention aims to solve the above-mentioned problems, and forms an image under diffuse reflection light and regular reflection light by forming ink containing the glitter material and colored ink having the same hue as the glitter material as a pair ink. Is a printed matter that has the effect of changing the image, has a high image change effect, is highly resistant to counterfeiting, is easy to manufacture, and does not require two dedicated inks. provide.

  The present invention has, at least in part, a color different from the base material having first significant information visible under diffuse reflected light and second significant information visible under specular reflected light. The printed image was formed with the first image formed with the glitter ink, the same hue as the glitter ink under diffuse reflected light, and the color ink darker than the glitter ink. The first image is formed by superimposing a second image having a latent image portion and representing the second significant information. The first image has a density of the information portion and a latent image camouflage portion obtained by inverting the density of the latent image portion. The second image is divided by the difference in density between the latent image portion and the background portion, and each density of the information portion of the first image and the latent image camouflage portion is under diffuse reflected light. From the density of the first significant information represented by The first image is formed with a density obtained by subtracting the density of the second image. Under the diffuse reflected light, the first significant information is visually recognized due to the difference in light and shade of the printed image. Under the regular reflected light, the first significant information is recognized. It is an anti-counterfeit printed matter characterized in that second significant information can be visually recognized.

  The present invention is the anti-counterfeit printed matter, wherein the glitter ink is silver ink and the colored ink is black ink.

  The present invention is the anti-counterfeit printed matter, wherein the difference between the maximum area ratio and the minimum area ratio of the halftone dot area ratio of the first image exceeds at least 50%.

  The two images constituting the anti-counterfeit printed matter of the present invention can be formed with one glossy ink and the other with a normal colored ink darker than the glitter ink. Due to the technical features, the dark ordinary colored ink paired with the glitter ink is an ink having a certain density or more, so it is the same as the ink that constitutes the other design elements of the printed matter on which the anti-counterfeit printed matter is formed. There is no need to use two paired inks exclusively to form the present technology, and only one glittering ink needs to be prepared only for the formation of the anti-counterfeiting technology. For this reason, the present technology can be configured by using one cylinder for the printing unit, and inks of different colors can be supplied to other printing cylinders in order to form design elements other than the anti-counterfeiting technology. As a result, it is possible to increase the degree of freedom in the color design of design elements other than the forgery prevention technology in the printed matter.

  The two images constituting the anti-counterfeit printed matter of the present invention have a fixed positional relationship of overlapping portions, and therefore basically require a certain printing accuracy. However, since there is no problem even if the inks that make up each of them overlap, the outline of the image is thickened so that the two images overlap slightly, as is done in normal printing operations, and the redundancy of printing is increased. Can be secured. Therefore, it is not necessary to fit the images together by removing the hair as in the prior art described in Patent Document 4, and manufacturing is easy because the printing accuracy is not as high as in the prior art.

  Unlike the technique of Patent Document 1, the anti-counterfeit printed matter of the present invention is invisible under diffuse reflection because the second image, which appears as an image that appears under specular reflection light, is completely camouflaged by the first image. And the concealment is high.

  In addition, since the transparent ink as in the prior art described in Patent Document 2 and Patent Document 3 is not used, there is no need to emit and manage the latent image as in the prior art, and the image formed by the colored ink is not necessary. Quality should be controlled visually. For this reason, after the two images overlap to form a printed product as a printed product, it is difficult to see the configuration, and resistance to forgery is high.

  The anti-counterfeit printed matter formed by the above method can be manufactured by offset printing, which is a highly productive printing method, so it has excellent cost performance, and even if the latest digital equipment is used, it realizes the switch effect Since it is impossible, the anti-counterfeiting effect is excellent.

The forgery prevention printed matter in this invention is shown. The outline | summary of a structure of the forgery prevention printed matter in this invention is shown. FIG. 3 shows a schematic diagram of a first image density calculation method according to the present invention. The layer structure of the forgery prevention printed matter in this invention is shown. The effect of the forgery prevention printed matter in this invention is shown.

  DESCRIPTION OF EMBODIMENTS Embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below, and includes various other embodiments within the scope of the technical idea described in the scope of claims.

  First, the present invention will be described with reference to the drawings. In FIG. 1, the forgery prevention printed matter (1) in this invention is shown. The anti-counterfeit printed matter (1) has a printed image (3) having a color different from that of the base material (2) on the base material (2). The printed image (3) represents the first significant information under diffuse reflected light. In the present embodiment, the first significant information indicates an alphabet “A” and a circle surrounding it. That is, in the present invention, the entire symbol represented by the printed image (3) under diffuse reflected light is set as the first significant information.

  The print image (3) is formed by superimposing the first image (4) and the second image (5) shown in FIG. The first image (4) is composed of an information part (4A) and a latent image camouflage part (4B), which are classified by the difference in density. The information part (4A) is composed of the letter “A” of the alphabet of the printed image (3) under diffuse reflected light by the contour shape (outline), and one latent image camouflage part (4B) This is an image obtained by removing the information portion (4A) from the first image (4). Specifically, the information portion (4A) is removed from an image obtained by inverting the density of the latent image portion (5A) described later. It has a configuration. The first image (4) is formed by glittering ink.

  On the other hand, the second image (5) has a latent image portion (5A) and a background portion (5B) adjacent to the latent image portion (5A) divided by a density difference, and a specific angle of specular reflection light. 2 constitutes the second significant information appearing in the printed image (3). The background portion (5B) is the same size as the printed image (3) and is in contact with the latent image portion (5A). The latent image portion (5A) is not included in the background portion (5B) due to its configuration. In this embodiment, the latent image portion (5A) is dark and the background portion (5B) is light. However, the background portion (5B) is dark and the latent image portion (5A) is light. There is no problem even if the configuration has a configuration. The second significant information in the present embodiment indicates the letter “B” of the alphabet and a circle surrounding it. That is, in the present invention, the entire symbol represented by the print image (3) under the regular reflection light is set as the second significant information. The second image (5) has the same hue as that of the glitter ink and is formed of a normal colored ink having a higher density.

  The information part (4A) and the latent image camouflage part (4B) in the first image (4) have a density difference, and the latent image part (5A) and the background part (5B) in the second image (5). ) Needs to have a density difference. This is an essential condition for expressing the first significant information and the second significant information by shading. Note that a constant density is essential for the information part (4A) and the latent image camouflage part (4B) of the first image (4), but the latent image part (5A) of the second image (5) or The reflection density of either one of the background portions (5B) may be zero.

  In addition, the first image (4) has not only a difference in density between the information part (4A) and the latent image camouflage part (4B), but also the information part (4A) and the latent image camouflage part (4B). With different shades. The structure of the light and shade in the information part (4A) and the latent image camouflage part (4B) will be described with reference to FIG. The density of the first image (4) is the density obtained by subtracting the density of the second image (5) that overlaps the same position from the density of the first significant information that the printed image (3) represents under diffuse reflected light. Consists of. This will be specifically described with reference to FIG.

  Assuming that the printed image (3) is formed in gray, which is an achromatic color, the letter “A” in the printed image (3) has a black component reflection density of 1.0. And the other area of the printed image (3) has a black component reflection density of 0.5, and the latent image portion (5A) of the second image (5) has a black component reflection density. When the background portion (5B) has a black component reflection density of 0.1 and a density of 0.1, the density of the first image (4) decreases the density of each region. Automatically determined.

  That is, the dark part of the information part (4A) representing the alphabet “A” is the reflection density of the black component of the letter “A” of the alphabet of the printed image (3), from 1.0 to the second image (5). The reflection density of the black component in the background part (5B) of the image is obtained by subtracting 0.1 to obtain a reflection density of 0.9, and the light part of the information part (4A) is the letter “A” in the alphabet of the printed image (3) The reflection density of the black component is 1.0, and the reflection density of the black component of the latent image portion (5A) of the second image (5) is reduced by 1.0 to 0.6. The dark part of the latent image camouflage part (4B) is the reflection density of the black component other than “A” of the printed image (3), and is from 0.5 to the background part (5B) of the second image (5). The reflection density of the black component is obtained by subtracting 0.1 to obtain a reflection density of 0.4, and the light portion of the latent image camouflage portion (4B) is the reflection density of the black component in the region other than “A” of the printed image (3). Thus, the reflection density of the black component of the latent image portion (5A) of the second image (5) from 0.5 is reduced by 0.4 to 0.1.

  In the above description, the density of only the black component is described as the achromatic color of the print image (3). However, when the print image (3) is a chromatic color, the print image (for all color components of yellow, red, blue, and black) The density of the first image (4) may be determined by subtracting the density of the second image (5) from the density of 3). In the anti-counterfeit printed matter (1) of the present invention, the first image (4) and the second image (5) are simply overlapped, and the print image (3) is composed of subtractive color mixture. The density of the first image (4) can be automatically determined by subtracting the density of the second image (5) at the same position from the density of the printed image (3). If the density of each image is determined by the above procedure, the forgery-preventing printed material (1) of the present invention can be formed.

  Further, in order to enhance the image change effect, it is necessary to limit the image that the print image (3) represents under diffuse reflection light, that is, the density of the first significant information. Specifically, the density difference between the maximum density and the minimum density of the first significant information needs to be 0.1 or more and 1.5 or less. If it is less than 0.1, it is because the visibility of the first significant information under the diffuse reflected light is too low, and if it exceeds 1.5, the first significant information under the regular reflected light is This is because it does not disappear. In addition, since the second image (5) needs to be completely hidden in the shade of the printed image (3), the maximum density of the second image (5) is printed under diffuse reflected light. It is necessary to make the image represented by the image (3), that is, the minimum density of the first significant information or less.

  Further, desirable conditions for the second image (5) after satisfying the above-described density conditions will be described below. When the latent image portion (5A) is completely concealed under diffusely reflected light, but the visibility of the second significant information under regular reflected light is low, the latent image portion (5A) and the background portion (5B) ) To increase the density difference. The condition that either one of the density of the latent image portion (5A) and the background portion (5B) is set to the same value as the minimum density value of the first significant information and the density of either one is 0 is the second significant This is the condition for the highest visibility of information.

  On the other hand, the color balance between the glittering ink and the colored ink is poor, and the latent image portion (5A) and the latent image camouflage portion (4B) are not the same color under diffuse reflected light, and the second significant information is If the image cannot be completely hidden, the density difference between the latent image portion (5A) and the background portion (5B) may be reduced in order to improve the concealability of the latent image portion (5A).

  In this way, by adjusting the density difference between the latent image portion (5A) and the background portion (5B), the visibility of the second significant information can be improved, or the difference in color between the two inks, glitter ink and colored ink. The concealability of the second significant information can be improved by reducing the difference in color on the image derived from.

  In addition, it is desirable to design a large difference between the maximum area ratio and the minimum area ratio for the halftone dot area ratio of the first image (4). This is because the difference between the maximum area ratio and the minimum area ratio of the halftone dot area ratio of the first image (4) is synonymous with the difference in lightness of the first significant information under diffuse reflected light. In addition to being directly linked to the visibility of significant information, the size of the halftone dot area ratio of the first image (4) composed of the glitter ink is the reflection at the time of regular reflection of the first image (4). Since the amount of light is directly connected, the higher the maximum area ratio, the higher the visibility of the second significant information.

  Based on the above, regarding the dot area ratio of the first image (4), the difference between the maximum area ratio and the minimum area ratio is desirably at least 50%, and more desirably 70%. This is because, when it is 50% or less, the visibility of the second significant information under specular reflection light becomes low. Further, from the results of a plurality of levels of tests conducted by the applicant in carrying out the invention, a remarkable effect was observed when the ratio exceeded 70%. The above is the description of the second image.

  Next, the specific color relationship and optical characteristics of the glitter ink that forms the first image (4) and the colored ink that forms the second image (5) will be described. First, the relationship between the colors of the two inks will be described. One of the features of the present invention is that the color ink, which is one of the paired inks, is shared with the ink constituting the design elements other than the anti-counterfeiting technology such as the background pattern, the coloring pattern, and the characters, thereby forming the anti-counterfeiting technology. Therefore, it is not necessary to use two colors of dedicated ink.

  The specific reason why the colored ink used in the present invention is an ink having the same hue as that of the glitter ink and having a deeper color relationship than that of the glitter ink under diffuse reflected light will be described. The fact that the glitter ink and the colored ink have the same hue is an indispensable matter for hiding the second image (5) from the first image (4) composed of the glitter ink. If the hues of the two inks are different, no matter how the density is adjusted, the second image (5) cannot be completely hidden in the first image (4).

  In addition, regarding the concentration of colored ink, the color ink used for the construction of anti-counterfeiting technology and the ink used for the construction of design elements other than the anti-counterfeiting technology should be shared, and the degree of freedom in color design of design elements should be increased. As long as the purpose is, the darker the color, the greater the freedom of color design for the design elements. When using dark ink, a lighter color than ink can be achieved by adjusting the dot area ratio of the printed pattern, but on the contrary, it is impossible to achieve a color darker than the ink density. Because there is. In this way, by using a dark ink as a pair ink, restrictions on the color design of design elements other than the anti-counterfeiting technology are minimized.

  For these reasons, in the present invention, the colored ink paired with the glitter ink uses an ink having the same hue as that of the glitter ink and having a higher density than the glitter ink. The above is the description of the specific color relationship between the glittering ink constituting the first image (4) and the colored ink constituting the second image (5).

  Subsequently, the optical characteristics of the two inks will be described. The glitter ink needs to have a so-called light / dark flip-flop property that has a certain density under diffusely reflected light, and strongly reflects light under specularly reflected light to change its color lightly. Further, it may have a so-called color flip-flop property in which the hue is changed by strongly reflecting light under regular reflection light. That is, the glitter ink needs to have a greatly different color under diffuse reflection light and under regular reflection light. On the other hand, the color ink has a constant density under diffuse reflected light, and does not reflect light strongly under regular reflected light. The color under diffuse reflected light and the color under regular reflected light change significantly. It is desirable not to. The greater the difference between the color of the glitter ink under the specular reflection light and the color of the colored ink under the specular reflection light, the greater the visibility of the second significant information appearing under the specular reflection light. The above is an explanation of the optical properties of the two inks.

  Here, specific examples of glitter ink and colored ink will be described. In the anti-counterfeiting technology of the present invention, when silver ink is used for the glitter ink and black ink is used for the colored ink, the characteristics are most effectively exhibited. Silver ink and black ink belong to the same hue, and since black ink is generally about twice darker than silver ink, it satisfies the conditions required for the pair ink constituting the present invention. In the present invention, a series of achromatic colors of white, gray, and black are also considered to belong to one and the same hue.

  Silver ink is one of the excellent glitter inks that stably generate high reflected light even in offset printing, and black (black ink) is a color used for characters and designs of most printed materials. It is a highly versatile color. In other words, even if no anti-counterfeiting technology is given, black is almost always the color that is originally used, so it is necessary to use glitter ink for preparation of anti-counterfeiting technology only. Only certain silver inks are available. As described above, in constructing the anti-counterfeiting technology of the present invention, it can be said that a combination of pair inks using silver ink for glittering ink and black ink for colored ink is ideal. However, the ink used in the configuration of the present invention is not limited to this, and may be a combination of red gold ink and reddish orange ink, blue gold ink and bluish orange ink, or the like.

  Next, the stacking order of the first image (4) and the second image (5) will be described with reference to FIG. As shown in FIG. 4A, the anti-counterfeit printed matter (1) of the present invention can be printed on the base material (2) after the second image (5) is printed and the first image (4) is superimposed. After the first image (4) is printed on the base material (2) as shown in FIG. 4B, even if the second image (5) is superimposed, the two images are only superimposed. An image change effect appears. However, the image change effect is relatively high in the form in which the second image (5) is superimposed on the first image (4) shown in FIG. This is because, similar to the techniques of Patent Documents 1 to 3, the colored ink layered thereon has an effect of blocking incident light incident on the first image (4). This is because the contrast of the image is relatively increased and the visibility of the second significant information is increased.

  As described above, when priority is given to the image change effect, it may be formed in the stacking order shown in FIG. 4B. In this case, the metallic ink is used by the printing cylinder arranged on the printing mechanism. If the first image (4) formed in step 4 is defective due to the printing order, such as “mukare” or “picking” that is partially taken by the next printing cylinder, In some cases, the stacking order shown in FIG.

  The effect of the forgery prevention printed matter (1) produced with the above structure is demonstrated using FIG. The positional relationship among the light source (6), the anti-counterfeit printed matter (1), and the observer (7) is determined based on the observation angle (the incident angle of the light incident on the printed matter) as shown in FIG. (Α) (45 ° in this example) and the reflection angle (β) that connects the observer and the printed material are significantly different (0 ° in this example)), The letter “A” of the alphabet, which is significant information, is visually recognized. Under diffuse reflection, the letter “B” of the alphabet, which is the second significant information, cannot be visually recognized. The observation angle where the diffuse reflected light is dominant is a state where there is almost no specular reflected light and the ratio of the diffuse reflected light is extremely large.

  On the other hand, as shown in FIG. 5B, the anti-counterfeit printed matter (1) is an angle where the regular reflected light is dominant (the angle of light incident on the printed matter (α) and the reflection angle connecting the observer and the printed matter). When observed within an angle range where (β) is a close value (both angles are 45 ° in this example), the alphabetical “1” that is the first significant information indicated by the first image (4). The letter “A” disappears completely, and the letter “B” of the alphabet as the second significant information is visually recognized. The angle where the regular reflection light is dominant is a state where the diffuse reflection light is small and the ratio of the regular reflection light is large.

  The basic principle of changing two images of the present invention is as follows. The first significant information is visually recognized by the difference in density in the printed image (3) at the observation angle where the diffuse reflected light shown in FIG. In addition, at the observation angle where specular reflection light is dominant as shown in FIG. 5B, the light incident on the first image (4) composed of the glitter ink is specularly reflected and lightly changed. By doing so, the visual density difference in the area other than the second image (5) becomes relatively small, the gradation is compressed, and the first significant information becomes invisible. The color of one second image (5) does not change, and as a result, the second significant information represented by the second image (5) is visually recognized under specular reflection light. This is the principle of the image change effect in the anti-counterfeit printed matter (1) of the present invention.

  As described in the problem to be solved by the invention, when the first image (4) and the second image (5) are overlapped, the outline of the boundary portion of the image is thickened to overlap the two images. As a result, it is possible to ensure the redundancy of printing. Although an appropriate range differs depending on the density of the glitter ink and the colored ink, specifically, an overlapping region of about 0.05 mm to 0.50 mm may be provided. When the overlap becomes large, printing is easy, but the concealing property of the latent image portion (5A) is lowered, so it is necessary to stop at an appropriate value according to the density of the ink.

  The glitter ink that forms the first image (4) is an ink containing a glitter material having a characteristic of strongly reflecting light, and is an ink having a color different from that of the substrate (2). Any ink may be used as long as it is present. As inks that are commercially available as offset inks, there are silver inks and gold inks called metallic inks, and pearl inks containing special pearl pigments may be used. In addition, there is no problem even if a coloring pigment is mixed in addition to the glittering material. There is no problem even if the color of the color pigment is any color such as black, red, blue or yellow. However, when an excessive amount of pigment is mixed, even if the first image (4) is formed in the range of the appropriate halftone dot area ratio, the gradation expression area is too widened and the specular reflection light is reduced. In the observation with, an event occurs in which the first image (4) does not disappear completely. Therefore, in the case of mixing any of the colored pigments, it is desirable to keep the amount within a range that does not exceed a half of the blending ratio of the glittering material in the ink.

  The aforementioned glittering material may be a general metal powder pigment such as aluminum powder, copper powder, zinc powder, tin powder, brass powder, iron phosphide and the like. Further, general pearl pigments such as iris pearl pigments and scale pigments, functional pigments such as glass flake pigments and cholesteric liquid crystal pigments may be used.

  The colored ink that forms the second image (5) may have the same hue as the glitter ink. The ink may be glossy or matte, but it is desirable to use a matte transparent ink in order to achieve a high switching effect regardless of the substrate. This is because the mat-based ink is easy to increase the contrast of the second significant information under specular reflection light, and the effect of changing the image is enhanced. In addition, luminescent pigments such as fluorescent pigments, phosphorescent pigments, and phosphorescent pigments, IR absorbing pigments, photochromic pigments, temperature indicating materials, thermochromic materials, and other functional materials may be added to the colored inks. In addition to the effects, various functionalities can be added.

  For the order of determining the color of the paired ink, if the producer or user gives priority to the image change effect of anti-counterfeiting technology, first use glitter ink with high optical performance such as light / dark flip-flop and color flip-flop. Once found, the colors of the paired colored inks can be matched. In addition, if priority is given to the color design of the printed matter, after determining the color of the colored ink that will be the paired ink in advance, the glittering ink with a lighter color than the colored ink is prepared by appropriately blending the glittering pigment and the colored pigment. Just design.

  The printing method of the anti-counterfeit printed material in the present invention can be formed by any printing method such as offset printing, flexographic printing, letterpress printing, gravure printing, screen printing, intaglio printing, and the like. In addition, if metal ink can be used, it can be formed by various digital output machines such as IJP, laser printers, sublimation printers, etc. In this case, so-called variable that changes the information of each output product. Printing can be performed.

  In the present embodiment, the alphabet which is a binary image is used for the first significant information and the second significant information. However, the present invention is not limited to this, and each image has a large number of photographs and pictures. A gradation image may be used.

  Hereinafter, examples of the anti-counterfeit printed matter specifically produced according to the embodiment for carrying out the invention will be described in detail, but the present invention is not limited to the examples.

  Examples of the present invention will be described with reference to FIGS. 1 to 5 as in the embodiment. In the examples, white high-quality paper (manufactured by Shiraoi Nippon Paper Industries Co., Ltd.) was used as the base material (2).

  The reflection density of each part of the first image (4) and the second image (5) is the numerical value described in the embodiment, and the stacking order is the configuration shown in FIG. After printing the first image (4) using silver ink (UV No. 3 Silver, manufactured by T & K TOKA), black ink (UV 161, black S, manufactured by T & K TOKA) is used as the colored ink. The second image (5) was formed so as to be superimposed on the first image (4). The black ink had a reflection density about twice that of the silver ink.

  FIG. 5 shows the effect of the anti-counterfeit printed matter (1) of the present invention. FIG. 5A shows an image observed when the observer observes the anti-counterfeit printed matter (1) under diffuse reflected light. The printed image (3) includes an information section (4). The letter “A” of the alphabet which is the first significant information represented by is visually recognized. On the other hand, as shown in FIG. 5B, when the observer observes the forgery-preventing printed matter (1) at a specific observation angle under specular reflection light, the alphabet “A” is displayed from the printed image (3). The character disappeared, and instead, the character “B” as the second significant information represented by the latent image portion (5A) was visually recognized. As described above, the effect of changing two different images was confirmed.

DESCRIPTION OF SYMBOLS 1 Anti-counterfeit printed matter 2 Base material 3 Printed image 4 First image 5 Second image 4A Information part 4B Latent image camouflage part 5A Latent image part 5B Background part 6 Light source 7 Observer α Light incident angle β Light reflection angle

Claims (3)

A printed image having a color different from that of the base material, having at least a part of the first significant information visible under diffuse reflected light and second significant information visible under specular reflected light at least on the base material With
The printed image includes a first image formed with glitter ink, and a latent image portion formed with colored ink having the same hue as the glitter ink under diffuse reflected light and darker than the glitter ink. And the second image representing the second significant information is superimposed,
The first image is formed by dividing an information portion and a latent image camouflage portion obtained by reversing the density of the latent image portion according to a density difference,
The second image is formed by dividing the latent image portion and the background portion by a difference in density,
Each density of the information part and the latent image camouflage part of the first image is the density of the second image overlapping at the same position from the density of the first significant information represented by the print image under diffuse reflected light. Formed at a reduced concentration,
Under diffuse reflected light, the first significant information is visually recognized by the difference in shade of the printed image, and under the regular reflected light, the second significant information is visually recognized by a difference in optical characteristics of each ink. Anti-counterfeit printed matter.   The anti-counterfeit printed matter according to claim 1, wherein the glitter ink is a silver ink, and the colored ink is a black ink.   The forgery-preventing printed matter according to claim 1 or 2, wherein the difference between the maximum area ratio and the minimum area ratio of the halftone dot area ratio of the first image exceeds at least 50%.

Images