JP2023042045A - Counterfeit prevention printed matter - Google Patents

Abstract

【Theme】
In the present invention, it is possible to express more than 75% of gradation for visible images formed with glitter ink, and even when using high-quality paper as a base material, the effect of changing the image is high. To provide a forgery-preventive printed matter with high durability.
[Solution]
In the present invention, at least part of a substrate is provided with a printed image having a color different from that of the substrate, the printed image has a light-dark flip-flop property, and the color is the same as that of the substrate or is 20% with transparent ink. A second image formed with the above area ratio and a first image formed on the second image with a glittering ink having a color different from that of the base material are superimposed, and the second image is The first image comprises a background portion and an image portion having second significant information, and the first image is formed in a gradation representation area in which the difference between the maximum area ratio and the minimum area ratio in the image exceeds 75%. An anti-counterfeit printed matter characterized by having significant information.
[Selection drawing] Fig. 4

Description

In the field of security printed matter such as banknotes, passports, negotiable securities, identification cards, cards, transit tickets, etc., which require an anti-counterfeiting effect, the present invention can be used to obtain different images depending on the angle of incident light. It is related to anti-counterfeiting printed matter that changes to

With the recent development of digital devices such as scanners, printers, and color copiers, it has become possible to easily create elaborate copies of security printed matter. As one of anti-counterfeiting techniques for preventing such duplication and counterfeiting, there are many techniques in which an optical security element such as a hologram whose image changes depending on the printed matter or viewing angle is attached.

However, unlike conventional anti-counterfeiting technology that uses printing with ink, holograms are formed using complex manufacturing processes and special materials. It is time consuming and extremely expensive. For this reason, special light-reflecting powders such as metal ink, interference mica, oxide flake mica, pigment-coated aluminum flakes and optically variable flakes are blended with inks and paints, and special materials are superimposed and An anti-counterfeiting printed matter that can be formed by a general printing method has emerged, which realizes an image change similar to that of a hologram by using a complicated halftone dot configuration.

The present applicant has found that information recognized by the human eye at a specific site in the printed matter at a specific viewing angle, while using common and relatively inexpensive materials and simple printing means, We have already applied for an invention relating to an anti-counterfeiting information carrier that changes to completely different information by changing the information (see, for example, Patent Documents 1, 2, 3, and 4).

Japanese Patent No. 3398758 Japanese Patent No. 4604209 Japanese Patent No. 5358819 Japanese Patent No. 5920781

However, in the techniques described in Patent Documents 1 to 3, the difference between the maximum area ratio and the minimum area ratio in a visible image (first image referred to in the present technology) formed with glitter ink, the so-called scale It is necessary to limit the tone expression area (hereinafter, in the present invention, the difference between the maximum area ratio and the minimum area ratio in the image is referred to as the "gradation expression area") to 50% or less, and the most effective gradation Even in the technique of Patent Document 4, which can set the representation area, it was necessary to limit the maximum to 75% or less. If a visible image with a gradation expression range exceeding 75% is used, the visible image will not completely disappear under specularly reflected light, and will be visible mixed with the latent image, resulting in a reduced change effect. there were. Therefore, in the conventional technology, it is not possible to freely design a visible image. It was necessary to compress the gradation expression area to 50% or less with the technique of No. 2003-200344, and at least 75% even with the technique of Patent Document 4. As a result, the visibility of the visible image is relatively low, and thus there is a problem that it is difficult to apply to delicate designs with fine expressions and rich gradations.

In addition, the techniques described in Patent Documents 1 to 4 all exhibit a good image change effect when an image is formed using coated paper as a substrate to be printed, but they are not suitable for general high-quality paper. is used as a substrate to be printed to form an image, there is a problem that the effect of changing the image is relatively lowered. Compared to the case where coated paper is used as the base material to be printed on, when high-quality paper is used as the base material to be printed on, the unevenness of the base material is reflected on the surface of the printed image, and the amount of reflected light from the glittering ink is reduced. This is a problem caused by a large decrease, and was an unavoidable problem when fine paper was used.

An object of the present invention is to solve the above-mentioned problems, and it is possible to express more than 75% of gradation for a visible image formed with glitter ink, and when high-quality paper is used as a base material. To provide a forgery-preventive printed matter having a high image change effect and high resistance to forgery.

In the present invention, at least a part of a substrate is provided with a printed image having a color different from that of the substrate, and the printed image has a light-dark flip-flop property, and is the same color as the substrate or has a transparent ink of 20% or more. A second image formed with an area ratio of and a first image formed with a glittering ink having a color different from that of the base material on the second image are superimposed, and the second image is the background and an image portion having second significant information, wherein the first image is formed in a gradation representation area in which the difference between the maximum area ratio and the minimum area ratio in the image exceeds 75%. Under diffusely reflected light, the first significant information is visually recognized due to the difference in the image area ratio of the first image of the glittering ink. Under specularly reflected light, the difference in the optical characteristics of each ink causes The forgery-preventive printed matter is characterized in that the first significant information disappears and is visually recognized, and the second significant information is visually recognized.

The present invention is a forgery-preventive printed matter, wherein the second significant information further has a contour portion formed with an image area ratio higher or lower than that of the background portion.

The anti-counterfeiting printed matter of the present invention differs from the conventional techniques of Patent Documents 1 to 4 in that the gradation representation range of significant information in the first image formed with glitter ink exceeds 75%. can be expressed in a 100% gradation representation area without gradation limitation. As a result, it has become possible to express delicate images with rich gradations under diffusely reflected light, which has been difficult to express with conventional techniques.

The anti-counterfeiting printed material of the present invention, unlike the conventional technologies of Patent Documents 1 to 4, can achieve a high amount of reflected light from the first image formed with glittering ink even when high-quality paper is used as the base material. An excellent image change effect can be obtained by raising the second image formed with glossy ink. In that case, the second image is formed with a high gloss ink with a thick film thickness of 20% or more of the image area ratio, or the second image is formed with a low film thickness with a high image area ratio. As a result, it is possible to obtain a high leveling effect, so even when a printed image is formed using high-quality paper as the base material to be printed, it is not easily affected by the unevenness of the base material, and the second significant effect that appears under specularly reflected light The visibility of information is extremely high, and it demonstrates an excellent change effect.

The anti-counterfeiting printed matter formed by the above method can be formed with the same effect as the hologram only by printing, so it is excellent in cost performance, and even if the latest digital equipment is used, the switch effect can be realized. Therefore, it has excellent anti-counterfeiting effect.

1 shows anti-counterfeit printed matter in the present invention. 1 shows an overview of the configuration of a forgery-preventive printed matter according to the present invention; 1 shows a first image of anti-counterfeit printed matter according to the present invention; 1 shows the layer structure of the anti-counterfeit printed matter in the present invention; 2 shows a second image of anti-counterfeit printed matter in the present invention; 3 shows the effect of anti-counterfeiting printed matter in the present invention. 1 shows an overview of the configuration of a forgery-preventive printed matter according to the present invention; 3 shows the effect of anti-counterfeiting printed matter in the present invention.

A mode 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 ideas described in the claims.

(First embodiment)
First, the present invention will be described with reference to the drawings. FIG. 1 shows an anti-counterfeit printed matter (1) according to the present invention. An anti-counterfeit printed matter (1) has a printed image (3) on a substrate (2) having a color different from that of the substrate (2). As shown in FIG. 2, the printed image (3) represents the first significant information (9) under diffusely reflected light, and represents the second significant information (10) (image portion) under specularly reflected light. Become. In the first embodiment, the first significant information (9) is the letter "A" and the second significant information (10) is the letter "B". The first embodiment is an example in which the first significant information (9) and the second significant information (10) are simple binary images (hereinafter referred to as "binary images"). .

The printed image (3) consists of two images superimposed as shown in FIG. The two images are the first image (4) and the second image (5). The first image (4) represents the letter "A" of the alphabet, which is the first significant information (9), with glitter ink colored with the object color, while the second image ( 5) represents the letter "B" of the alphabet, which is the second significant information (10), in the same color as the substrate (2) or in transparent ink. The first significant information (9) and the second significant information (10) are not limited to characters, and may represent any images such as numbers, symbols, marks, patterns, people and landscapes. Also, the first image (4) does not express the simple binary image shown in FIG. Images (monochrome gradation images and color gradation images) may also be used.

The first image (4) and the second image (5) have a layer structure in which the first image (4) is superimposed on the second image (5) as shown in FIG. The overlapping area of the first image (4) and the second image (5) becomes the printed image (3). If the sizes of the first image (4) and the second image (5) are different, the area where the two images do not overlap becomes a mere decoration area adjacent to the print image (3). As a matter of course, the modified region does not need to satisfy various conditions and configurations necessary for configuring the printed image (3) of the forgery-preventive printed matter (1) of the present invention.

First, the first image (4) will be specifically described. The first image (4) consists of representing the first significant information (9) with a tonal coverage of more than 75% by pigmented glitter ink. In the first embodiment, the first image (4) represents the letter "A" with an area ratio of 100% and constitutes the background of the letter "A" with an area ratio of 10%. Therefore, in the first embodiment, the maximum area ratio of the first image (4) is 100% and the minimum area ratio is 10%. is 90%.

In many conventional techniques, the gradation expression area of the first image (4) must be kept at 50% or less, and even with a particularly excellent special technique, the gradation expression area must be kept at 75% or less. was there. In this technology, by adapting the special image configuration and structure of the second image (5), it is possible to express the first image (4) using a gradation representation range exceeding 75%. rice field.

The glitter ink used to form the first image (4) is an ink containing a glitter material having a characteristic of strongly reflecting light, and has an object color and is visible. Any color ink may be used. Commercially available offset inks include silver inks and gold inks called metallic inks, and pearl inks containing special pearl pigments may also be used. In addition, there is no problem even if a coloring pigment is mixed in addition to the luster material. The color of the coloring pigment may be black, red, blue, yellow, or any other hue.

The above-mentioned glitter material may be aluminum powder, copper powder, zinc powder, tin powder, brass powder, or common metal powder pigments such as iron phosphide. Ordinary pearl pigments such as iridescent pearl pigments and scaly pigments, and functional pigments such as glass flake pigments and cholesteric liquid crystal pigments may also be used.

These glitter inks have light-dark flip-flop properties and/or color flip-flop properties as optical properties. In the present invention, the term "light-dark flip-flop property" refers to the property that the brightness of a substance changes when light is incident on the substance, and the term "color flip-flop property" means that when light is incident on the substance, refers to the property that the hue changes. Inks with "color flip-flop properties" basically also have "light-dark flip-flop properties" at the same time. If the color flip-flop property is provided, the hue changes in addition to the lightness, so that the color expression becomes richer and the resistance to counterfeiting becomes higher. In any case, by using the light-darkness flip-flop property and the color flip-flop property, the brightness of the entire first image (4) is increased during specular reflection, and the gradation of the first significant information (9) is compressed. Therefore, it is possible to obtain an effect that the first image (4) disappears visually.

Since the first image (4) does not need to be formed with a particularly thick ink film, it can be formed by a highly productive printing method such as offset printing or letterpress printing. Alternatively, it may be formed by gravure printing or flexographic printing according to the manufacturer's needs. In addition, in recent years, digital printers and digital printing machines that have made remarkable progress include models that can print bright inks such as gold and silver. Variable printing with different information is also possible, which is particularly effective for adding personal/individual information. As long as the glitter ink can be used in this way, the method for forming the first image (4) does not matter. The above is the description of the first image (4).

Next, the second image (5) will be described. The second image (5) is the same color as the substrate (2) or using transparent ink with a light-dark flip-flop, as shown in FIG. 5(d). The image portion forming (10) and the background portion surrounding the image portion are formed to have an area ratio of 20% or more, that is, an area ratio in the range of 20% to 100%. In the image portion forming the second significant information (10) of the second image (5) existing in the lower layer of the first image (4) and the surrounding background portion, there is an area with a zero area ratio. must have an area ratio of at least 20% in any region. The disappearance effect of the first image (4) is maximized when the area ratio of the second image (5) existing in the lower layer is 100%.

In addition, in the present invention, as shown in FIGS. 4 and 5(a) to 5(c), a desirable form is a contour portion in which the edge of the second significant information (10) is represented by a "line without lines". (11). Therefore, in the first embodiment, the second significant information (10) will be described as having a contour portion (11). In this specification, the term "blank line" refers to a line with a relatively lower area ratio than the surrounding area. The effect of the present invention can be obtained even if the image area ratio is higher or lower than the area ratio for forming the second significant information, for example.

In the first embodiment, as a desirable example, as shown in FIG. 4, the edge of the letter "B", which is the second significant information (10), is placed in a circle with an area ratio of 100%. It has an outline (11) represented by a "blank line" with an area ratio of 0% with a streak width of 0.2 mm. In the present invention, the second image (5) is set to have an area ratio of 20% or more in all areas, but the "blank line" keeps the image line width to 1 mm or less, As an exception, even in the second image (5), an area ratio smaller than 20% can be set. The dotted line indicating the outline (11) is shown for convenience of explanation, and does not indicate a part of the outline (11) and is not actually formed.

The reason why the second image (5) is composed of an area ratio of 20% or more and has a light-dark flip-flop property, is the same color as the base material (2), or is formed with transparent ink is that This is to enhance the disappearance effect of the first image (4) superimposed on the second image (4) at the time of specular reflection. Therefore, even a large grayscale difference that cannot be completely erased can be erased by superimposing it on the second image (5).

Suppose that the configuration of the second image (5) in the first embodiment is such that the alphabet "B", which is the second significant information (10), has an area ratio of 100%, and its surroundings (background portion ) has an area ratio of less than 20% to 0%, only a partial area of the first image (4) superimposed on the alphabet “B” with an area ratio of 100% is under specularly reflected light. However, the first image (4) superimposed on other areas with an area ratio of less than 20% to 0% is greatly impaired in the erasing effect. This is because the disappearance effect of the superimposed first image (4) under specularly reflected light is greatly affected by the area ratio of the second image (5). Even if a printing method capable of forming a high gloss and a thick printing film such as screen printing is used, the minimum area ratio of the second image (5) is 20% of the first image ( This is the limit at which the complete elimination effect of 4) can be ensured. In the case of using a printing method such as offset printing in which the printing film thickness is relatively thin, setting the area ratio of the second image (5) to a high value provides a better erasing effect.

As described above, the second image (5) is an area of the image representing the second significant information (10) from the periphery in order to construct the second significant information (10) that appears under specularly reflected light. It must be formed with a so-called “Nuki line” with a low rate. In the first embodiment, the edge of the letter "B" (contour portion (11)), which is the second significant information (10), is formed by a 0.2 mm "blank line". If the area ratio of the periphery is 100%, a line with a relatively lower area ratio can be regarded as a "blank line". If it is a "blank line", there is no problem even if it is formed with an area ratio of less than 20% exceptionally. By limiting the image line width to 1 mm or less, the deterioration of the disappearance effect of the first image (4) superimposed thereon is suppressed, and the second image (5) and the first image (5) are displayed under specularly reflected light. This is because it is possible to prevent a phenomenon in which the images (4) appear to be mixed.

The visibility of the second significant information (10) appearing under the specularly reflected light becomes higher when the area ratio of the "blank line" is low and the image line width is large. However, when the area ratio is low and the line width is large, the second significant information (10) is visualized under diffuse reflection, or the ink trapping becomes different from the surroundings, resulting in the first Since the significant information (9) may become ambiguous, it is necessary to find an appropriate value each time.

In the first embodiment, an example in which the "line without lines" is configured by a continuous line has been described, but it is not limited to a continuous line, and any configuration such as a dividing line, a broken line, a dashed line, a branch line, etc. line may be used.

FIG. 5 shows some variations in which the area ratio is changed when the second significant information (10) of the second image (5) is the letter "B". As in the printed matter (1) shown in FIG. 4 described above, the simplest form is a configuration in which "B" is represented by a "blank line" in a circle with an area ratio of 100%. In addition, as shown in FIGS. 5( a ) to 5 ( c ), the edge of “B” (contour portion (11)) is represented by “line of blank”, and “B” itself and its surrounding area By changing the area ratio of and the type of image to lines or meshes, it is possible to add intensity of light to the second significant information (10) that appears under specularly reflected light, thereby expanding the range of expression. Under specular light, areas with high area ratios appear brighter, and areas with low area ratios appear darker. will be reversed. As described above, the second image (5) expresses the second significant information (10) under specularly reflected light by changing the area ratio of a part of the image together with the "blank lines". can be made richer.

In addition, when forming the second image (5), it is necessary to use an ink having a contrast flip-flop property. Examples of inks that are transparent or translucent and have light-and-dark flip-flop properties include transparent resins for inks, mediums, varnishes, and the like. Inks called medium, varnish, clear ink, and gloss ink, which are transparent and feel glossy, easily satisfy the constituent requirements of the second image (5) because they have light-and-dark flip-flop properties. Moreover, in addition to the light-dark flip-flop property, an ink having a color flip-flop property may be used. Pearl ink exists as a transparent ink having this color flip-flop property. Iridescent pearl ink is colorless and transparent, so it is suitable as the ink for forming the second image (5).

The second image (5) can be formed with a high image area ratio using a printing method such as offset printing with a low ink film thickness, but a thick film such as screen printing or gravure printing can be formed. It is desirable to form by a printing method that can be used. In particular, when the second image (5) is formed with a thick film thickness by screen printing, it is relatively less affected by the unevenness of the surface of the substrate (2). Even in this case, high contrast flip-flop properties can be maintained, and deterioration of the change effect can be prevented, which is most desirable. The above is the description of the second image (5).

The effect of the anti-counterfeiting printed matter (1) produced with the above configuration will be described with reference to FIG. When the positional relationship between the light source (6), the anti-counterfeiting printed matter (1), and the observer (7) is observed at an observation angle in which diffusely reflected light is dominant as shown in FIG. In (7), the alphabet "A", which is the first significant information (9), is visually recognized. Under the diffusely reflected light, the letter "B", which is the second significant information (10), cannot be visually recognized.

On the other hand, when the anti-counterfeiting printed matter (1) is observed at an angle where specularly reflected light is dominant, as shown in FIG. 6(b), the first significant information ( The letter "A", which is 9), completely disappears, and the letter "B", which is the second significant information (10), is visually recognized. As described above, completely different images can be visually recognized under diffusely reflected light and under specularly reflected light.

The basic principle of the two-image change of the present invention is as follows. The first significant information (9) of the first image (4) is visually recognized due to the difference in density in the printed image (3) at the observation angle shown in FIG. 6(a) where the diffusely reflected light is dominant. Since the second image (5) is color matching or transparent to the substrate (2), its presence has no effect on the shading in the printed image (3). Therefore, only the first significant information (9) of the first image (4) in the printed image (3) is visually recognized by the density of the glitter ink.

At an observation angle where the specular light is dominant, as shown in FIG. , the brightness of the first significant information (9) in the first image (4) is greatly increased as a whole, and as a result, the gradation is compressed and visually the first significant information (9) is captured will not be Although it is difficult to obtain a sufficient contrast compression effect only with the light-dark flip-flop property of the first image (4), the second image (5) placed below the first image (4) By adding the light-dark flip-flop property of , a sufficient grayscale compression effect is produced on the first image (4), and visually the first significant information (9) is completely lost. In addition, at this time, since the "blank line" in the second image (5) does not emit reflected light, it is set as a "blank line" with a relatively low brightness against the background of which the brightness is greatly increased. ” is visually recognized by the observer. For this reason, under the specularly reflected light, the first image (4) disappears, and the second image (5) given by the "outline line" in the second image (5) changes to the contrast of light. Visualized by the difference. This is the principle of the image change effect in the anti-counterfeit printed matter (1) of the present invention.

In the present invention, the observation angle at which diffusely reflected light is dominant refers to an angle in which specularly reflected light is almost absent and the proportion of diffusely reflected light is extremely large. On the other hand, an observation angle at which specularly reflected light is dominant refers to an angle at which there is little diffusely reflected light and a large proportion of specularly reflected light.

(Second embodiment)
Next, as a second embodiment, a mode in which a color image (8) is added in addition to the first image (4) and the second image (5) will be described. In the first embodiment, the first significant information (9) visible under diffusely reflected light and the second significant information (10) visible under specularly reflected light are binary images. A form of a color image rich in color expression in which color information is added to each of the first significant information (9) and the second significant information (10) will be described.

FIG. 7 shows a first image (4), a second image (5) and a color image (8) in the second embodiment. The first significant information (9) represented by the first image (4) is a landscape multi-gradation image representing Mt. Fuji, and the second significant information (10) represented by the second image (5). is a binary image representing cherry blossom petals. The color image (8) is an image having three different colors including white in addition to pink and blue. Matters that are not particularly explained in the second embodiment are the same as those explained in the first embodiment.

The first image (4) is expressed with a gradation representation range of 100% and has no gradation limitation. This is because, in addition to the high area ratio of the second image (5), which is the background, the first significant information (9) is an image that uses gradation frequently and has a gradual change in gradation compared to a binary image. Due to something.

The second image (5) is an image in which the contours and patterns of cherry blossom petals are bordered by a "blank line" with an image line width of 0.15 mm with an area ratio of 0% in a solid image with an area ratio of 100%.

It is desirable that the color image (8) has color commonality with both the first image (4) and the second image (5). This color sharing property means that even if the color of the color image (8) is superimposed on the first image (4), the color of the color image (8) is superimposed on the second image (5). However, the relationship between the shading and the color of each image is established. It is a feature provided by (8). That is, for the color image (8), the configuration of the color image described in JP-A-2020-040348 may be used. As described above, in Japanese Patent Application Laid-Open No. 2020-040348, the characteristics provided by the color image (8) with respect to the glitter image and the latent image are described in the first image (4) and the second image of the present invention. By providing the color image (8) with respect to (5), the effect of changing a monochrome image to another monochrome image as in the first embodiment can be achieved by converting a colorful color image into another color image. It can be changed into an effect that changes to

Specifically, the color image (8) should be of colors that can be combined consistently with both the first image (4) and the second image (5). The characteristic that the shading of the two different images of the first image (4) and the second image (5) and the color of the color image (8) match without contradiction is referred to as "the first image (4) and the second image (5). image (5) has color commonality with color image (8)."

In fact, whether or not the first image (4) and the second image (5) have color commonality with the color image (8) is determined by image processing software, plate-making film, etc. Visually confirm that there is no contradiction in the gradation and color of the synthesized image by visually confirming the synthesized image obtained by synthesizing (4) and color image (8), and similarly, second image (5) and color image (8). It is necessary to confirm whether there is any contradiction in the shades and colors of the synthesized image by visually recognizing the synthesized image.

In the first place, it is impossible to completely match the color arrangement of the first significant information (9) and the second significant information (10), which are different images. Therefore, first, in order to establish a relationship in which the first image (4), the second image (5), and the color image (8) have color commonality, the first significant information (9) and the second It is necessary to design the second significant information (10) itself as an image with a similar color arrangement. It is difficult to secure the final color commonality without taking into consideration the fact that

In designing the first significant information (9) and the second significant information (10), red placed in green, yellow placed in blue, etc., especially the eyes of the observer (10) It is desirable to design with an emphasis on giving commonality to the color arrangement of the portion where the color difference is large, that is, the portion where the color difference is large. The difference in color and shading in a portion with a large color difference gives the observer (10) the most sense of incongruity. Conversely, if the colors and shading of the portion with a large color difference match, the observer (10) does not feel uncomfortable with the image. As described above, first, it is desirable to design the first significant information (9) and the second significant information (10) so that the shading and the color of the portions with large color difference match as much as possible.

After devising the design of the first significant information (9) and the second significant information (10), there is no room for further color sharing, or the customer decides to use the first significant information (9) When the second significant information (10) is designed and there is no room for design improvement on the design side, no further design improvement can be expected, and there is still a large contradiction between the shades and colors. It is necessary to adjust the color of the contradictory region of the image (8) or apply image processing such as blurring or gradation. Below are described some means of enhancing color coherence.

The surest and easiest method to increase the color commonality, that is, to eliminate the contradiction between shading and color is to make the color of the color image (8) in the region of the contradiction closer to achromatic color. That is, the saturation of the color of the contradictory portion of the color image (8) should be lowered. As a matter of course, when the color image (8) is composed only of achromatic colors such as white, gray, and black, the color image (8) with respect to the shades of the first image (4) and the second image (5) There is no contradiction with the color of Therefore, if the color saturation of the color image (8) is reduced, the contradiction between the density and the color will be small regardless of the combination of the first significant information (9) and the second significant information (10). Therefore, the color sharability is always improved in the direction of relatively increasing. However, the closer the color image (8) is to an achromatic color, the more the colorization effect of the present invention is impaired and the effect is reduced. It is desirable to limit the rate of desaturation to the areas where the inconsistency is noticeable and keep it to the minimum width possible. If the saturation C* is 3 or more, even if the first image (4) is superimposed with any high area ratio, it can be recognized as a chromatic color. Therefore, the color image (8) has a saturation C* of 3 or more. It is desirable to have at least one color of The saturation C* is a numerical value in the CIE L*a*b* color space.

The color image (8) may be formed by printing or may be formed by a printer, and the method is not limited. The first image (4), the second image (5) and the color image (8) as described above are laminated. The color image (8) can be placed on any layer, but the first image (4) must be placed on a layer above the second image (5).

The effect of the anti-counterfeiting printed matter (1) formed with the above configuration will be described with reference to FIG. When the positional relationship between the light source (6), the anti-counterfeiting printed matter (1), and the observer (7) is observed at an observation angle in which diffusely reflected light is dominant as shown in FIG. 8(a), the observer ( In 7), an image of Mt. Fuji colored in blue, pink, and white, which is the first significant information (9), is visually recognized. Under diffusely reflected light, the second significant information (10) is not visible.

On the other hand, the anti-counterfeiting printed matter (1) is assumed to be at an angle where specular reflection light is dominant, as shown in FIG. 8B. Mt. Fuji, which is the first significant information (9) indicated by the first image (4), completely disappears, and the second significant information ( 10) colored cherry blossom petals are visually recognized. As described above, in the second embodiment, completely different color images can be visually recognized under diffusely reflected light and specularly reflected light. The above is the description of the second embodiment.

The inks forming the first image (4) and the second image (5) have functions such as fluorescent pigments, phosphorescent pigments, luminescent pigments such as luminous pigments, IR absorbing pigments, photochromic pigments, thermochromic materials, thermochromic materials, etc. Functional materials may also be added, in which case various functionalities can be added in addition to the image switching effect.

An example of the present invention will be described with reference to FIGS. 7 and 8 in the same manner as the second embodiment. In the examples, a white, highly versatile fancy paper (Gladios CC: manufactured by Nippon Paper Industries) was used as the substrate (2).

First, a color image (8) was printed onto the substrate (2). The color image (8) was printed with three colors of pink, blue and white using a color laser printer (IPSIO SP C820: manufactured by RICOH). The main component reflection density of blue is 0.12, and pink is 0.10. A second image representing the cherry blossom petals as the second significant information (10), and expressing the petals with a “blank line” with a stroke width of 0.15 mm and an area ratio of 0% in a circle with an area ratio of 100%. (5) was printed by screen printing with transparent gloss ink (UV TUB-000, manufactured by Teikoku Ink Mfg. Co., Ltd.). The first image (4) is the first significant information (9), which is a landscape painting representing Mt. (manufactured by T&K TOKA Co., Ltd.) was used to print over the second image (5) by offset printing.

FIG. 8 shows the effect of the anti-counterfeit printed matter (1) of the present invention. FIG. 8(a) is an image observed when an observer observes the anti-counterfeiting printed matter (1) under diffusely reflected light, and the printed image (3) contains the first significant information (9 ), a color image of Mt. Fuji was visually recognized. On the other hand, as shown in FIG. 8(b), when the observer observes the anti-counterfeit printed matter (1) at a specific observation angle under specularly reflected light, the image of Mt. Fuji disappears from the printed image (3). , a color image of cherry blossom petals, which is the second significant information (10), was visually recognized instead. As described above, the excellent effect of the present invention was confirmed that an image with rich gradation expression was changed to another image.

1 anti-counterfeit printed matter 2 base material 3 printed image 4 first image 5 second image 6 light source 7 observer 8 color image 9 first significant information 10 second significant information 11 outline

Claims (2)

At least a part of the substrate is provided with a printed image having a color different from that of the substrate,
The printed image includes a second image having a light-dark flip-flop property and formed with an area ratio of 20% or more with an ink that is the same color as the base material or transparent, and the base on the second image. Consists of superimposing a first image formed by a glittering ink having a color different from that of the material,
the second image comprises a background portion and an image portion having second significant information;
the first image has first significant information formed in a gradation representation area in which the difference between the maximum area ratio and the minimum area ratio in the image exceeds 75%;
Under diffusely reflected light, the first significant information is visually recognized due to the difference in the image area ratio of the first image of the glittering ink. A forgery-preventive printed material, wherein one piece of significant information disappears and is visually recognized, and the second piece of significant information is visually recognized. 2. The anti-counterfeit printed matter according to claim 1, wherein said second significant information further has a contour portion formed with a higher or lower image area ratio than said background portion.

Images