JP2017087632A - Forgery preventive printed matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forgery preventive printed matter that has a high effect of changing images even when the print is formed on a high-quality paper, has high resistance to forgery, and can be easily manufactured with high cost effectiveness.SOLUTION: A second image 5 having first significant information and second significant information formed by using a density difference in a brilliant ink, and a third image 6 having the second significant information formed and segmented by using a density difference in a chromatic ink having the same hue as that of the brilliant ink are superposed on a first image 4 having at least a region formed by using an ink having the same color as that of a base or a transparent ink to have a dot area rate of 50% or more. The second image 5 is formed to have a density resulting from subtraction of the density of the third image 6 from the density of the printed image; and under diffused reflection light, the first significant information is visible by the density difference, and under regular reflection light, the first significant information disappears owing to differences in optical characteristics of the inks while the second significant information is visible.SELECTED DRAWING: Figure 2

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 JP 2014-042991 A

  However, all of the techniques described in Patent Documents 1 to 4 exhibit a good image change effect when an image is formed using coated paper as a substrate to be printed. In the case where an image is formed on the substrate to be printed, there is a problem that the effect of changing the image is greatly reduced. This is a problem caused by the fact that the amount of reflected light of the glitter ink is greatly reduced when high-quality paper is used as the substrate for printing compared to the case where coated paper is used as the substrate for printing. When paper was used, it was an inevitable problem.

  Furthermore, regarding the technique of Patent Document 1, the luster material constituting the first print image and the color material constituting the second print image are different in hue, so that they are originally visually recognized in the observation under diffuse reflected light. There is a problem that the second print image that should not be seen, and the second print image is configured with a sparse area ratio, so that the visibility of the second print image that appears under specular reflection light is present. There was a problem of 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 for forming 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. However, since transparent ink that cannot be visually observed is used, there is a problem that it is difficult to control 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 technique described in Patent Document 4 is configured such that two images are formed using a glittering material and a colored ink having the same color as the glittering material as a pair ink, and the optical properties of the two equal color inks under specular reflection light. This technology achieves the effect of changing images by utilizing the difference in characteristics, but each image composed of two inks is the most difficult combination called “tweeping” that fits so that they do not overlap each other. When a slight misalignment occurs, the latent image is visualized. Although the anti-counterfeiting effect is very high, there is a problem that a high-precision printing machine and a skilled operator are necessary for manufacturing.

  Regarding the technique of Patent Document 5, although the change effect on the fine paper is improved as compared with the techniques of Patent Document 1 to Patent Document 4, the transparent images of the techniques of Patent Document 2 and Patent Document 3 are improved. Thus, it does not have a layer structure that suppresses incident light incident on an image formed with glittering ink, and the reflection of light under specular reflection due to the difference in the optical characteristics of the ink used as in the technique of Patent Document 4 Since there is no configuration for adjusting the amount of light, the contrast of the latent image under the specular reflection light tends to be lower than the techniques of Patent Document 2 to Patent Document 4, and the visibility may be slightly inferior. There was a problem that there was.

  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. Even if it is printed on high-quality paper, it has a high image change effect, high resistance to counterfeiting, and easy manufacturing and cost performance prevention. Provide prints.

  The present invention has at least a part of the substrate having first significant information that is visible under diffuse reflected light and second significant information that is visible under specular reflected light, and having a color different from that of the substrate. The printed image is provided with a glittering ink on the first image having at least a region formed with a halftone dot area ratio of 50% or more using the same color or transparent ink as the base material. The second significant image formed by dividing by the light and shade difference using the second image having the first significant information and the second significant information formed by the light and dark difference, and the colored ink having the same hue as the glitter ink. The second image is formed by superimposing a third image having information, and the second image is formed by subtracting the light and shade of the third image from the light and shade of the printed image. Significant information is visible and the light of each ink under specular reflection. The first significant information is lost by the difference in characteristics, a forgery prevention prints the second significant information, characterized in that the visible.

  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 second image exceeds 50%.

  The present invention is the anti-counterfeit printed matter, wherein the first image further has second significant information formed by negative-positive reversal of the second significant information of the third image.

  The present invention is the anti-counterfeit printed matter, wherein the first image is formed with a white ink containing a titanium white pigment.

  The anti-counterfeit printed matter of the present invention is different from the conventional techniques of Patent Document 1 to Patent Document 4, even when formed on high-quality paper, the amount of reflected light of the second image formed with glittering ink is the first image. Has the effect of being raised. Therefore, even when a print image is formed using high-quality paper as a substrate to be printed, the visibility of the second significant information that appears under specular reflection light is extremely high, and an excellent change effect is exhibited.

  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. Therefore, when a print image is formed by overlapping two images, it is difficult to see the configuration, and the resistance to forgery is high.

  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 if the inks that make up each other overlap, the redundancy of printing is increased by thickening the outline of the image and slightly overlapping the two images, as in normal printing operations. Can be secured. Therefore, it is not necessary to fit the images together by tweezing like the prior art described in Patent Document 4, and manufacturing is easy because high printing accuracy is not required.

  In addition, unlike the technique of Patent Document 5, since it has a structure that increases the contrast of the second significant information that appears under specular reflection light using paired inks having different optical characteristics, even when it is formed on fine paper, it is specular reflection. The visibility of the second significant information that appears in the light is extremely high, and exhibits an excellent change effect.

  Since the anti-counterfeit printed matter formed by the above method can be manufactured by offset printing, which is a highly productive printing method, it is excellent in cost performance, and even if a color copier is used, it is possible to realize a switch effect Since it is impossible, it has an excellent anti-counterfeit effect.

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 second 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. 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. The layer structure 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 embodiment)
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, and represents the second significant information under regular reflected light. In the present embodiment, the first significant information is a pattern of “running water”, and the second significant information is a character “Cherry Blossom”.

  The print image (3) is formed by superimposing three images as shown in FIG. The three images are the first image (4), the second image (5), and the third image (6). In the first embodiment, the first image (4) and the third image (6) include the same second significant information “sakura”, and the first image (4) The third image (6) has a negative-positive relationship in which the shades in each image are inverted. That is, when the third image (6) is represented by positive, the first image (4) is represented by negative, and when the third image (6) is represented by negative. The first image (4) is represented by positive. However, there is an example in which the first image (4) and the third image (6) do not have to have a negative-positive relationship, and an example thereof will be described later in the second embodiment. In the present specification, “light / dark” means that a specific color is distributed with various color densities (reflection densities) in an arbitrary image, and is synonymous with gradation. When representing the color density of a specific point in the image, it is simply described as color density or reflection density.

  The second image includes both a pattern of “running water” that is the first significant information and a character “sakura” that is the second significant information. The characters “Sakura” are arranged with the shades of the third image reversed. The shade of the second image is determined by subtracting the shade of the overlapping third image (6) from the pattern of “running water” that is the first significant information represented by the printed image (3) under diffuse reflected light. The A specific method for calculating the density of the second image will be described later. The above is the outline of the configuration of the print image (3).

  Next, the first image (4) will be specifically described. The first image (4) needs to be made of a material that is the same color as the substrate (2) or is transparent. This is a requirement necessary for making the second significant information represented by the first image (4) invisible under diffuse reflection light invisible. The first image (4) in FIG. 2 has a structure in which the characters “sakura” can be seen on a gray background. This is for ease of explanation of the image structure. The first image (4) actually formed therein has an invisible configuration.

  The first image (4) is an image directly formed on the base material (2), and serves to smooth the surface of the paper having countless irregularities due to entanglement of fine fibers such as fine paper to some extent. . For this reason, it is desirable to form the first image (4) with a printed film that is as thick as possible within the range that can be formed by printing. For this reason, about the area | region where the area ratio of a 1st image (4) is high, it is necessary to exceed at least 50% by a halftone dot area ratio. If the dot area ratio is lower than 50%, the surface of the substrate (2) cannot be sufficiently smoothed, and the visibility of the second significant information appearing under specular reflection light is reduced. Therefore, it is not desirable. More preferably, it is formed so as to exceed 75%. This is because it was confirmed from the results of the tests conducted at several levels by the applicant on the invention that a remarkable effect was seen when the value exceeded 75%. Further, in order to enhance the effect of the present invention, it is desirable to form with a dot area ratio close to 100% on the condition that printing troubles such as picking and puncture do not occur.

  When the substrate (2) is a general white fine paper, the first image (4) is preferably formed with white ink having a high glossiness. Of the white inks, white ink using titanium white as a pigment is most desirable because it has a high concealing effect on the substrate (2) and the smoothness of the printed portion.

  Although the first image (4) is invisible because it is formed with the same color ink as the base material (2), the first image (4) includes the second significant information. The second significant information is constituted by the difference in the dot area ratio. In the example of the first embodiment, the area ratio of the “cherry blossom” portion in the first image (4) is low, and the area ratio of the surrounding portion surrounding the “sakura” is high. . The relationship between the area ratio of the “cherry” part and the area ratio of the surrounding part is the relationship between the area ratio of the surrounding part of the area ratio of the “cherry” part of the second significant information in the third image (6). Must be reversed (negative / positive relationship). That is, when designing the first image (4), it is necessary to decide whether the second significant information that appears under specular reflection light is to be shown as a negative or as a positive, as in this embodiment. In addition, if you want to show positively the second significant information that appears under specular reflection light, increase the area ratio of “cherry blossoms” so that “cherry blossoms” in the third image (6) looks positive. It is necessary to design the surrounding area ratio to be low, to design the area ratio of “sakura” in the first image (4) to be low, and to design the surrounding area ratio to be high.

  In the halftone dot configuration of the first image (4), it is desirable to design the difference in the halftone dot area ratio representing the second significant information as large as possible. The halftone dot configuration with the highest effect is a configuration in which the difference in area ratio is 100%. That is, in the example of the first embodiment, it is most effective that the character “sakura” has a halftone dot area ratio of 0% and the surrounding area ratio is composed of a halftone dot area ratio of 100%. It is the composition which becomes. However, in the configuration with a dot area ratio of 100%, there is a possibility that printing troubles such as picking and puncturing may occur, and therefore, it may be suppressed to about 85% depending on the printing state. If the difference in the halftone dot area ratio is small, the visibility of the second significant information that appears under specular reflection light is lowered, which is not desirable. The above is the description of the first image (4).

  Next, the third image (6) will be described. Originally, the second image (5) should be explained first, but the configuration of the third image (6) is determined first for the design of the shade of the second image (5). In the present specification, the third image (6) will be described first because the state is easier to explain.

  The third image (6) represents the second significant information that appears under specular reflection light. The third image (6) is different from the invisible first image (4), and the third image (6) itself has a density that can be captured with the naked eye and represents the second significant information. The light and shade in the third image (6) appears in a state in which the light and shade are more emphasized under specular reflection light. Therefore, the light and shade of the second significant information appearing under specular reflection light is taken into consideration. It is necessary to design the shade of the image (6).

  The third image (6) needs to be formed with a colored ink having the same hue as the glitter ink used in the formation of the second image (5). This is because when the print image (3) is finally formed, the third image (6) becomes invisible by fitting with the second image (5). For this purpose, it is necessary that the respective predetermined regions have the same color in a state where the third image (6) and the second image (5) are fitted together. Among these colors, the brightness can be controlled by adjusting the halftone dot area ratio at the time of plate design and the ink film thickness at the time of printing, but at least two inks are used at the ink design stage. If they do not have the same hue, it is impossible to have the same color when the two images are fitted together. For this reason, the colored ink that forms the third image (6) needs to have the same hue as the glitter ink used in the formation of the second image (5). The color in the present invention is a concept including brightness, saturation, hue, etc., brightness is the brightness of the color, saturation is the vividness of the color, and hue is the color aspect such as red, yellow, blue, etc. Is. In this specification, it is defined that white, black and gray achromatic colors are included in the same hue.

  Specifically, if the second image (5) is formed with silver ink, the third image (6) needs to use an achromatic color, that is, white, gray, black, or the like. When the second image (5) is formed with gold ink, the third image (6) needs to use ink such as yellow or orange.

  Further, the colored ink for forming the third image (6) needs to have a difference in reflectance under the specular reflection light and the glitter ink used in the formation of the second image (5). This is an indispensable requirement for causing the second significant information to appear under regular reflection light and for improving the visibility. Since the glitter ink is basically a highly reflective ink, it is desirable that the colored ink forming the third image (6) has a lower reflectance than the glitter ink in practice. The visibility of the second significant information is increased. It can be said that the mat is desirable as much as possible.

  Only when the configuration including the second significant information is included in the first image (4) as in the first embodiment, the area ratio configuration of the third image (6) is used. There are no restrictions. It is sufficient that the second significant information is simply expressed with shading, and the area ratio does not affect the effect even if it is high or low. Further, in the first embodiment, the third image is a case where the surroundings of the characters “Sakura” are in a white-skinned state with no color density, but the second significant information is to be shown positively. Alternatively, a certain color density may be arranged around the “sakura”. In the case of such a form, the visibility of the second significant information under the specular reflection light is slightly reduced, but the ink constituting the second image (5) and the third image (6), etc. Since redundancy with respect to chromaticity and redundancy with respect to misalignment of the second image (5) and the third image (6) are increased, a more preferable embodiment is provided when more importance is attached to manufacturing stability. One can say. The above is the description of the third image (6).

  Next, the second image (5) will be described. The second image (5) needs to be formed by a glittering ink having a color different from that of the substrate (2). The glitter ink is an ink containing a glitter material having a characteristic of strongly reflecting light, and any ink may be used as long as the ink has a color different from that of the substrate. 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 color pigment is mixed in addition to the glittering material. There is no problem even if the color of the color pigment is any hue such as black, red, blue, and yellow. However, when an excessive amount of pigment is mixed, even if the second image (5) is formed in the range of the appropriate halftone dot area ratio, the gradation expression area is too widened under regular reflection light. In this observation, an event occurs in which the second image (5) does not completely disappear. 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. Moreover, you may use functional pigments, such as general pearl pigments, such as an iris color pearl pigment and a scale-like pigment, a glass flake pigment, and a cholesteric liquid crystal pigment.

  A description will be given of the density of the second image (5). The light and shade of the second image (5) is obtained by subtracting the light and shade of the third image (6) overlapped at the same position from the light and shade of the first significant information indicated by the printed image (3) under diffuse reflected light. Determined by As an example, FIG. 3 shows a specific image and numerical values.

  Under diffuse reflected light, the first significant information represented by the print image (3) is expressed by two shades of the dark portion (3A) and the light portion (3B), and the third image (6). The second significant information represented by is also described by an example expressed by two shades of a dark portion (6A) and a light portion (6B). Here, the first significant information in the printed image (3) is that the dark portion (3A) has a reflection density of 1.0, the light portion (3B) has a reflection density of 0.5, and the third image ( In the second significant information of 6), it is assumed that the dark portion (6A) has a reflection density of 0.5, and the light portion (6B) has a reflection density of 0. In this case, the density of the second image (5) is obtained by subtracting the density of the third image (6) from the printed image (3). The shade density of the region (5A) other than the character “sakura”, which is the second significant information, overlaps with the light portion of the image (6) of the second image (6) is the reflection density of the light portion of the third image (6). Since it is 0, the reflection density of the print image (3) is inherited as it is. That is, the dark area has a reflection density of 1.0, and the light area has a reflection density of 0.5. On the other hand, in the second image (5), the density of the region (5B) overlapping the dark portion (5A) of the third image (6) is the reflection density of the dark portion of the third image (6). Since it is 0.5, the reflection density is obtained by subtracting 0.5 from the original reflection density of the printed image (3). That is, the dark area has a reflection density of 0.5, and the light area has a reflection density of 0. By the above calculation, the shade of the second image (5) is determined. The first significant information and the second significant information are both binary images. However, the present invention is not limited to this, and there is no problem even if the image is a multi-tone image. The color density can be calculated by the method, and the shade can be designed. These shade designs are not calculated as described above, and there is no problem even if they are automatically performed during image processing using image software. As described above, if the shade of the first significant information in the printed image (3) and the shade of the second significant information in the third image (6) are determined, the shade of the second image (5) is Determined automatically. The above is the description of the shade structure of the second image (5).

  Regarding the design of the area ratio of the second image (5), the visibility of the first significant information under the diffuse reflected light is basically improved when the difference between the maximum area ratio and the minimum area ratio is larger. It is desirable that the difference in area ratio in the second image (5) is large. Further, the visibility of the second significant information under specular reflection light is basically the same. The difference between the maximum area ratio and the minimum area ratio of the area ratio of the second image is desirably at least more than 50%, and more desirably 75%. This is because, when it is 50% or less, the visibility of the second significant information under specular reflection light becomes low. Moreover, it is because the remarkable effect was seen when it exceeded 75% from the test result of the several level which the applicant carried out in invention. The above is the description of the second image.

  Next, the design of the shade of the print image (3) will be described. If the design value of the difference in shading in the printed image (3) is large, the visibility of the first significant information under diffuse reflected light is improved, but conversely the first significant information is lost under regular reflected light. It may not be possible. For this reason, it is necessary to provide a certain restriction on the density difference in the printed image (3). This is unclear because it is affected by the performance of the glitter ink used in the second image (5), but the difference in density (maximum reflection density and minimum reflection density in the printed image (3)). When the reflection density of the main color component exceeds 1.0, the first significant information cannot be completely lost under specular reflection light, no matter how bright ink having excellent optical characteristics is used. From the above, it is necessary that the light / dark difference in the printed image (3) is 1.0 or less in reflection density, and more preferably 0.75 or less. The reason why the above-mentioned numerical value is recommended is that, based on the results of the tests conducted by the applicant on the basis of a plurality of levels, it has been confirmed that a certain effect starts to occur at a reflection density of 1.0 or less, and a more remarkable effect was observed. This is because it was confirmed that it was 0.75 or less. Similarly, since the effect of disappearance of the first significant information under specular reflection light is drastically reduced, the printed image (3) is completely exposed in such a size that the substrate (2) can be visually observed. Providing such areas should be avoided.

  Since the third image (6) needs to be completely hidden in the shade of the printed image (3), the maximum reflection density of the third image (6) is the printed image (3). It is necessary to make it below the minimum reflection density.

  Subsequently, the stacking order of the first image (4), the second image (5), and the third image (6) will be described with reference to FIG. The anti-counterfeit printed matter (1) of the present invention is printed after the first image (4) is printed on the substrate (2) and the second image (5) is superimposed as shown in FIG. Three images (6) may be laminated, or after the first image (4) is printed on the substrate (2) as shown in FIG. 4B, the third image (6) is superimposed. After that, the second image (5) may be laminated, and the second image (5) and the third image (6) are even superimposed on the first image (4). Image change effect. In particular, as in the first embodiment, the second image (5) and the third image are arranged in a configuration in which the periphery of the “cherry blossom” in the third image (6) is a white dog (area ratio 0%). Since there are few portions where (6) is superimposed, there is almost no difference in effect regardless of which image is on top. On the other hand, when a configuration having a constant color density around “sakura” is used, it is more effective to use the configuration of FIG. This is because the second image (5) is in the uppermost layer, so that the light incident on the second image (5) is not hindered by the third image (6). It is desirable to properly use the stacking order according to the configuration.

  As the positional relationship of printing, it is required that each of the three images is accurately fitted. Specifically, the position where the character position of “sakura”, which is the second significant information formed with the same size, is overlapped with the position relationship that completely matches in each image is the most appropriate position relationship. Become. However, there is no problem even if an overlap portion is provided in the contour portion of each image for the purpose of ensuring the redundancy of printing.

  The effect of the forgery prevention printed matter (1) produced with the above structure is demonstrated using FIG. The positional relationship between the light source (7), the anti-counterfeit printed matter (1), and the observer (8a) is determined based on the observation angle (the incident angle of light incident on the printed matter) as shown in FIG. (Α) and the angle at which the reflection angle connecting the viewer and the printed material is greatly different (in this example, 0 degree)), the viewer has a pattern of “running water” as the first significant information. Visible. Under the diffuse reflected light, the Chinese character “Sakura”, which is the second significant information, is not visible.

  On the other hand, the anti-counterfeit printed matter (1) is obtained by changing the angle at which the specularly reflected light is dominant (the incident angle (α) of light incident on the printed matter, the observer (8b) and the printed matter as shown in FIG. The angle of reflection (β) connecting the two is observed within a close range), the pattern of “running water”, which is the first significant information indicated by the first image (4), disappears completely. The character of “Cherry blossom”, which is the second significant information, is visually recognized.

  The basic principle of changing two images of the present invention is as follows. At the observation angle where the diffusely reflected light is dominant as shown in FIG. 5A, the first significant information is visually recognized by the difference in light and shade in the printed image (3). Since the first image (4) is formed in the same color as the substrate (2), its presence does not affect the shading in the printed image (3). The third image (6) is designed to be shaded so as to be hidden in the shade of the first significant information by fitting with the second image (5). The presence is not visually recognized, and only the first significant information in the printed image (3), which is a composite image of the two images, is visually recognized by the shade of a specific hue.

  On the other hand, as shown in FIG. 5B, the second image (5) in the printed image (3) reflects light very strongly at the observation angle where the specular reflection light is dominant. The image (6) is hardly reflected (it does not change from the state under diffuse reflection). The presence of the first image (4) makes this tendency more pronounced. Since the second image (5) composed of glittering ink reflects the incident light regularly, the reflected light is extremely strong, so the observer cannot grasp the intensity of the reflected light. As a result, the entire image can be recognized only when it emits light substantially equally. For this reason, under regular reflection light, the second image (5) visually changes lightly to reduce the difference in density, and the density difference in the region other than the third image (6) disappears visually. The first significant information becomes invisible. On the other hand, the third image (6) does not reflect light strongly, so the density of the third image (6) does not change, and as a result, the third image (6) under regular reflection light. The second significant information represented by is visually recognized. This is the principle by which an image change effect occurs in the forgery-preventing printed material (1) of the present invention.

  The angle where the diffusely reflected light is dominant in the present invention is an angle at which the incident angle (α) of the light incident on the printed material and the reflection angle connecting the observer and the printed material are greatly different. Has almost no specular reflection light, and the ratio of diffuse reflection light is extremely large. On the other hand, the angle where the regular reflection light is dominant is an angle range in which the incident angle (α) of the light incident on the printed material and the reflection angle (β) connecting the observer (8b) and the printed material are close to each other. This angle has a small amount of diffusely reflected light and a large proportion of specularly reflected light.

  As described in the problem to be solved by the invention, when the first image (4), the second image (5), and the third image (6) are overlapped, the outline of the boundary portion of each image is thickened. Thus, the redundancy of printing can be ensured by overlapping the two images. Since the first image (4) is invisible, an overlap of about 0.5 mm can be provided. Regarding the relationship between the two images of the second image (5) and the third image (6), the appropriate range differs depending on the color density of the glitter ink and the colored ink itself. Even if an overlapping region of about 05 mm to 0.2 mm is provided, the visibility is hardly affected. However, since the concealing property of the third image (6) in which the overlap between the inks having the color density becomes large is lowered, it is necessary to stop at an appropriate value according to the color density of the ink. If an excessive amount of overlap is provided, the second significant information will be visualized under diffuse reflected light and must be avoided.

  Functional inks such as fluorescent pigments, phosphorescent pigments, and phosphorescent pigments, IR absorbing pigments, photochromic pigments, temperature indicating materials, and thermochromic materials may be added to each ink. In addition, various functionalities can be added.

  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, characters and patterns that are binary images are used for the first significant information and the second significant information. However, the present invention is not limited to this, and each image is like a photograph or a painting. Such a multi-tone image may be used.

  Subsequently, as a second embodiment, an example configured with a single gradation in which the second significant information is not included in the first image (4) will be described. In this case, not only the configuration of the first image (4) is changed, but also the third image (6) needs to be configured accordingly. This will be specifically described below.

(Second embodiment)
First, the forgery prevention printed matter (1 ') of 2nd embodiment is shown in FIG. 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, and represents the second significant information under regular reflected light. In the present embodiment, the first significant information is a pattern of “running water”, and the second significant information is a character “Cherry Blossom”. This is the same as in the first embodiment.

  As shown in FIG. 7, the print image (3 ′) is formed by superimposing three images. The three images are a first image (4 ′), a second image (5 ′), and a third image (6 ′). Of these image configurations, the biggest difference from the first embodiment is that the first image (4 ′) does not include the character “sakura” which is the second significant information. By constructing the first image (4 ′) with a single gradation that does not include the second significant information, as in the first embodiment, the Chinese character “4” in the first image (4). The second image (5 ′) and the third image (6 ′) with respect to the characters “sakura” do not need to be finely adjusted during printing, and the position adjustment can be made almost unnecessary.

  The effect of the first image (4 ′) is increased when the dot area ratio is increased. It is necessary to form the entire surface with a dot area ratio of at least 50%. In addition, it is more desirable to form with 75% or more. The other inks, printing methods, and the like constituting the first image (4 ′) are the same as those in the first embodiment, and are therefore omitted.

  When such a configuration of the first image (4 ′) is used, the second image (5 ′) need not be changed at all from the first embodiment, but the third image (6 ′). The configuration of needs to be changed. Specifically, the halftone dot area ratio of the third image (6 ′) needs to be designed to be high. The shading of the third image (6 ′) need not be changed from the first embodiment, but the halftone dot area ratio needs to be changed to be high. It is necessary to constitute at least 75% or more, and it is more desirable to form with a dot area ratio close to 100%.

  Unlike the first embodiment, when the entire first image (4 ′) is formed with a single gradation, the entire area of the printed image (3 ′) has a smooth surface property, and the printed image When light is incident on (3 ′), large reflected light is generated from the entire printed image (3 ′). Unlike the first embodiment, there is a state in which strong reflected light is generated from the region where the third image (6 ′) is formed, which should not generate reflected light. If strong reflected light derived from the first image (4 ′) is generated even from a region where the third image (6 ′) is present, the third image (6 ′) and the second image are also reflected under regular reflected light. And the image (5 ') becomes difficult to distinguish, and the visibility of the second significant information is greatly reduced. In order to avoid this, only the halftone dot area ratio of the third image (6 ′) is formed large while maintaining the shade design of the third image (6 ′), and the first image (4 ′) is formed. In addition to cutting the light incident on the light, the reflected light generated from the first image (4 ′) is also suppressed.

  In order to form only the halftone dot area ratio of the third image (6 ′) while maintaining the shade design of the third image (6 ′), it is used for forming the third image (6 ′). The ink needs to be light ink. It is more desirable that the ink has at least the same color density as that of the glitter ink of the second image (5 ′) or a color density lower than that. Of course, as described in the first embodiment, the hues of the glitter ink and the colored ink need to be the same. The above is the description of the configuration of the print image (3 ′) in the second embodiment. For the configuration of the image other than that the first image (4 ′) is formed with a single gradation and the halftone dot area ratio of the third image (6 ′) is designed to be high, Since it is the same as that of embodiment, description is abbreviate | omitted.

  Next, the stacking order of the first image (4 ′), the second image (5 ′), and the third image (6 ′) will be described with reference to FIG. As shown in FIG. 8A, the anti-counterfeit printed matter (1 ′) of the present invention prints the first image (4 ′) on the substrate (2 ′), and then the second image (5 ′). The third image (6 ′) may be laminated after superimposing the images, and as shown in FIG. 8B, after the first image (4 ′) is printed on the substrate (2 ′), After superimposing the third image (6 ′), the second image (5 ′) may be laminated, and the second image (5 ′) and the third image are stacked on the first image (4 ′). As long as the two images (6 ′) are superimposed, an image change effect appears. This is the same as in the first embodiment.

  The effect of the anti-counterfeit printed matter (1 ′) produced with the above configuration is the same as that shown in FIG. 5 in the first embodiment, and the first significant information is specular reflection under diffuse reflected light. The second significant information is visually recognized under light, and the visually recognized image in the printed image (3 ′) is changed according to the difference in observation angle. Since the principle of effect expression is the same as that of the first embodiment, the description thereof is omitted.

  As described in the second embodiment, when the configuration of the first image (4) is changed, the printed matter of the first embodiment is changed by changing the configuration of the third image (6). It is possible to achieve substantially the same effect. Compared with the printed matter of the first embodiment, the printed matter of the second embodiment is a printing control of the second image (5) and the third image (6) with respect to the first image (4). Is almost unnecessary, and is characterized by easier production by printing. However, the image change effect itself is superior to the configuration described in the first embodiment, and in the configuration of the second embodiment, it is used to form the third image (6). There are differences such as restrictions on the composition of the ink to be used.

  As described above, in the configuration of the present invention, it is necessary to select each configuration in accordance with the convenience of the manufacturer and the effect desired by the orderer, taking into account the advantages and disadvantages of each configuration.

  Hereinafter, examples of the anti-counterfeit printed matter (1) specifically produced according to the embodiment for carrying out the invention will be described in detail, but the present invention is not limited to these examples.

  Examples of the present invention will be described with reference to FIGS. 1 to 5 as in the first embodiment. In the examples, white fine paper (Shiraoi Nippon Paper Industries Co., Ltd.) was used as the substrate (2).

  The first image (4) was formed at a dot area ratio of 90% with white ink (No. 3 UV L Carton White GW, manufactured by T & K TOKA) using titanium white as a pigment. The reflection density of each part of the second image (5) and the third image is the numerical value described in the embodiment, and the stacking order is as shown in FIG. After printing the second image (5) using silver ink (UV No. 3 Silver Co., Ltd. T & K TOKA) as glitter ink, light gray colored mat ink (UVL Special Training P420C Matte) as colored ink The second image (5) was superimposed on the first image (4) using a gray T & K TOKA company). The gray colored mat ink had a reflection density of about one-third that of silver ink.

  FIG. 5 shows the effect of the anti-counterfeit printed matter (1) of the present invention. FIG. 5A is an image observed when the observer observes the anti-counterfeit printed matter (1) under diffuse reflected light, and the printed image (3) is the first significant information. A “running water” pattern was visible. On the other hand, as shown in FIG. 5B, when the observer observes the anti-counterfeit printed matter (1) at a specific observation angle under specular reflection light, the pattern of “running water” from the printed image (3) is It disappeared and the second significant information, “Cherry Blossom”, was recognized. As described above, it was confirmed that the excellent effect of the present invention in which two different images are changed even when high-quality paper is used as the base material (2).

1, 1 'anti-counterfeit printed matter 2, 2' base material 3, 3 'printed image 4, 4' first image 5, 5 'second image 6, 6' third image 7 light source 8a, 8b observer

Claims (4)

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 on at least a part of the base material Prepared,
The printed image is formed on the first image having at least a region formed with a dot area ratio of 50% or more using the same color or transparent ink as that of the base material. The formed second image having the first significant information and the second significant information, and the second image formed by being divided by a light and shade difference using a colored ink having the same hue as the glitter ink. Overlaid with a third image with significant information,
The second image is formed with a shade obtained by subtracting the shade of the third image from the shade of the printed image,
Under the diffuse reflected light, the first significant information is visually recognized by a difference in light and shade. Under the regular reflected light, the first significant information is lost due to a difference in optical characteristics of each ink, and the second significant information is lost. Anti-counterfeit printed matter characterized in that significant information can be visually recognized.   2. The forgery-preventing printed matter according to claim 1, wherein a difference between the maximum area ratio and the minimum area ratio of the halftone dot area ratio of the second image exceeds 50%.   The forgery prevention according to claim 1 or 2, wherein the first image further includes second significant information formed by negative-positive reversal of the second significant information of the third image. Printed matter.   The forgery-preventing printed matter according to any one of claims 1 to 3, wherein the first image is formed of a white ink containing a titanium white pigment.

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