JP2022120415A - Forgery preventive printed matter and manufacture method thereof - Google Patents

Abstract

To provide a forgery preventive printed matter formed by fitting a fine streak or a pixel, the printed matter easy to manufacture and capable of reducing a displacement at integration.SOLUTION: A forgery preventive printed matter includes a printed image composed of a first image having a latent image element and a second image having a density adjustment element and a background element fitted in a negative-positive relation. The two images are formed with two inks that can be observed as an isochromatic image under diffusion light. One of the inks has a different functionality or different property with regard to the other ink. The differences in functionality or property makes the printed image observable as a latent image. The printed matter is designed so that a width of the latent image element is thinner than a width of the density adjustment element, and a density of the latent image element is thicker than a density of the background element, the density of the background element is thicker than a density of the density adjustment element. The printed matter is configured to satisfy a condition that a value obtained by multiplying a value obtained by subtracting a value of the density adjustment element from a density value of background element by a value of the density adjustment element equals to a value obtained by multiplying a width value of the latent image element by the density of the latent image element.SELECTED DRAWING: Figure 5

Description

INDUSTRIAL APPLICABILITY In the field of security printed matter such as banknotes, passports, negotiable securities, identification cards, cards, tickets, transit tickets, etc., which require an anti-counterfeiting effect, the present invention can easily An anti-counterfeit printed matter that can be produced and a method for producing the same are provided.

With the recent development of digital devices such as scanners, printers, and color copiers, it has become easier to create elaborate copies of security printed matter. As one of the technologies to prevent such duplication and counterfeiting, the inks appear to be the same color or different colors under specific observations, depending on the type of light source used for illumination, the inclusion of filters that transmit only specific wavelengths, etc. Paired inks using the characteristics have been proposed. As an example, the present application provides a printed matter printed on a base material as a pair of ink with functionality (specifically, colored penetrating ink) and ink with no functionality that is the same color as the ink with functionality. A person has proposed (see, for example, Patent Document 1). The latent image elements and background elements of this printed matter are composed of fine image lines and pixels, and when observed at an observation angle at which diffusely reflected light is dominant, the printed image is visible, and specularly reflected light is dominant. When viewed at an angle, the hues of both inks are different and the latent image is visible.

In addition, there is a printing method in which images composed of paired inks are fitted together to form a printed matter in which a latent image is concealed, and an overlap region is provided in which two images are superimposed to reduce tolerance for printing misalignment. . There is no problem if the images are printed together by precise printing using a high-precision printing machine, but if misalignment occurs, the color of the base material (for example, white paper) is visible through the gaps between the images. There is a risk that it will be lost. To solve this problem, a printing method that provides an overlap area prevents the color of the base material from being visually recognized even if misalignment occurs. There is a risk that the outline of the The details of this printing method and problems will be described later.

To solve this problem, in a printed material having a latent image area and a contour area in the latent image area and a background area and a contour area in the background area, the density of the contour area of the adjacent latent image area and the contour area of the background area becomes equal. The applicant of the present invention has proposed a paired printed matter that can be produced by adjusting the density in such a way as to reduce misalignment (see, for example, Patent Document 2).

JP 2015-112797 A JP 2019-84691 A

However, the technique described in Japanese Patent Laid-Open No. 2002-200000 requires the most difficult printing, called tweezers, to fit the images formed with two inks so that they do not overlap each other.

Problems caused by tweezing alignment, conventional concrete means for increasing redundancy against misprinting, and the problems will be described with reference to FIGS. 1 to 4. FIG. First, FIG. 1A shows a printing method generally called tweezing. FIG. 1(b) shows a general method of providing an overlap to improve redundancy against printing misalignment. FIG. 1(c) shows a special printing method described in Patent Document 2 as an excellent conventional technique. The three types of technology groups shown in FIG. By having the overlap, the entire pattern is visually recognized in uniform shades and colors, and it is intended that the area (A) and the area (B) cannot be visually distinguished from each other.

First, the problem of tweezers will be described with reference to FIG. In this method, as shown in FIG. 2(a), when the area (A) and the area (B) are completely printed together by precise printing using a high-precision printing machine, visually, the area (A) and the area (B) is indistinguishable. However, as shown in FIG. 2(b), when the printing positions are misaligned, the region (C) becomes blank and the density of the region (D) is doubled. ) can be easily distinguished. As described above, it is impossible to distinguish between the area (A) and the area (B) when the tweezers are completely aligned, but when the alignment is slightly misaligned, the area (A) and the area (B) cannot be distinguished. There is a problem that the boundary of (B) can be easily determined.

Next, a problem when a general overlap is provided will be described with reference to FIG. Overlap is an area in which area (A) and area (B) are partially redundant by slightly widening the width of the boundary between either the adjacent area (A) or area (B), or both. is provided. With this method, even if misalignment occurs in printing, the misalignment can be made inconspicuous. Even if misalignment occurs as shown in FIG. 3B, if the amount of misalignment shown in area (C) and area (D) is equal to or less than the overlap width, no blank area will occur. As a result, printing misalignment is relatively inconspicuous. However, as shown in FIG. 3A, even if the areas (A) and (B) are aligned, the density increases by the overlap width shown in the areas (C) and (D). , the boundary between the area (A) and the area (B) is conspicuous. Therefore, the width of the overlapping portion is generally limited to 40 to 50 μm or less, which is difficult to see visually. As described above, when the overlap is provided, there is a problem that the density at the boundary between the area (A) and the area (B) increases regardless of whether the printing is aligned or misaligned. Also, with respect to the misalignment of printing by the width of the overlap, the misalignment of printing is relatively less conspicuous than that of truncation because white areas are less likely to occur, but the allowable misalignment width is extremely small. there were.

A problem of the technology described in Patent Document 2 will be described with reference to FIG. This method solves the problem of the conventional method of providing an overlap, and provides a contour area having a density gradient at the boundary between the area (A) and the area (B). As shown in FIG. 4(a), when the area (A) and the area (B) are completely printed together by precise printing, the area (A) and the area (B) cannot be visually distinguished. This is an advantage over conventional overlap, and this technique is suitable for hiding characters, symbols, and graphics. However, as shown in FIG. 4B, when the printing positions are misaligned, the density of the area (C) decreases and the density of the area (D) increases. Although the change in density at the boundary is smaller than that in the conventional overlap, it is difficult to avoid the change in density. As described above, in this method, when the printing is perfectly aligned, it is impossible to distinguish between the area (A) and the area (B), but when the printing is slightly misaligned, the blank area itself does not occur. However, there is a problem that the boundary between the area (A) and the area (B) can be easily discriminated as in the case of the conventional overlap.

As described above, in the conventional printing technique, if the allowable amount of printing misalignment is too small, if the printing is correct or if the printing is misaligned, the images of the area (A) and the area (B) There was a problem that the boundary between the two was conspicuous. In addition to this, with the two methods of providing overlap, if you want to hide thin and sharp lines, the width of the overlap added to the original line width will cause the sharpness of the original line to be lost. There was a problem. For example, if an image composed of sharp fine lines of 50 μm is desired to be concealed, and an overlapping portion of 25 μm is provided on both sides of the fine lines, the entire image line width becomes 100 μm. It becomes a line of the drawing line width. As described above, the method of providing an overlap is not suitable for the purpose of hiding fine lines, and there are many cases where it is not possible to respond to the delicate expression intended by the designer, so it is used for printed matter composed of fine lines I couldn't.

In addition, if a sheet-fed printing press with excellent matching accuracy is used, for example, it is possible to perfectly fit a pattern onto a small area paper such as A4 paper, or to provide an overlap to print in units of several tens of μm. is not at all difficult. However, when it is necessary to fit multiple small cuts on a large sheet of paper, such as Kikuban or Shirokuzenban, when each design needs to be fitted, only the expansion and contraction of the paper due to printing is necessary. However, since the print stretches about 100 μm over the entire paper, it is almost impossible to perfectly match all the small pieces of paper applied to the large-area paper. Moreover, it is even more so if the printing is performed using a web printing machine in which the print alignment is not stable.

An object of the present invention is to solve the above-mentioned problems, and to prevent counterfeiting that can be easily produced by alleviating misalignment due to printing in a printed matter configured by fitting fine lines and pixels. A printed matter and a method of making the same are provided.

At least a portion of the substrate is provided with a printed image comprising a first image and a second image interlaced in a negative-positive relationship, the first image and the second image being viewed under diffused light. One of the inks forming the first image and the second image is formed of two inks that are visually recognized as matching colors, and one of the inks has different functionality or different properties with respect to the other ink, and is viewed under diffused light. However, under certain viewing conditions, the difference in functionality or properties of the ink forming the first image and the ink forming the second image causes the first image or the second image to be latent. An anti-counterfeiting print that can be viewed as an image, the first image being composed of at least one or more latent image elements and the second image being white or a color lighter than the color of the ink forming the latent image. and at _least one or more background elements, the density of the background element is A5, the density of the density adjustment element is _A0 , the width of the density adjustment element is _W5 , and the density of the latent image element is is _A4 and the width of the latent image element is W4, satisfying all conditions of the following formulas (i), (ii), (iii) and ( _iv ).
Equation (i): (Density of background element (A ₄ )−Density of density adjustment element (A ₀ ))×Width of density adjustment element (W ₅ )=Density of latent image element (A ₄ )×Density of latent image element Width ( _W4 )
Equation (ii): Width of density adjustment element (W ₅ )>width of latent image element (W ₄ )
Formula (iii): density of background element (A ₄ ) > density of density adjustment element (A ₀ )
Equation (iv): density of latent image element (A ₄ )>density of background element (A ₅ )

A method for producing an anti-counterfeit printed matter having a printed image consisting of a first image and a second image on a base material, comprising: an image setting step of setting basic image data of the printed image; converting a first image and a negative second image, forming the first image from at least one or more latent image elements, the second image being solid white or having a lighter color than the first image; an image conversion step of forming a density adjustment element and at _least one or more background elements; density adjustment with the density of the latent image element as A4, the width of the latent image element as _W4 , and the density of the background element as _A5 ; Image adjustment that adjusts so as to satisfy all the conditions of the above formulas (i), (ii), (iii), and (iv), where the density of the element is A ₀ and the width of the density adjustment element is W ₅ and printing one of the first image and the second image with an ink that has a functionality or property that is observable under specific viewing conditions, and the other image, when printed, exhibits functionality under diffuse light. or an image printing step of printing with an ink that is visually recognized as the same color as the ink having the characteristic, and has a functionality different from the functionality or a characteristic different from the characteristic. .

According to the present invention, by increasing the density of the latent image element, narrowing the width, and printing within the density adjustment element provided within the background element, it is possible to alleviate misalignment in printing. Further, according to the method for producing an anti-counterfeit printed matter of the present invention, it is possible to easily produce an anti-counterfeit printed matter in which misprints are not conspicuous.

1 shows a conventional common means for increasing printing redundancy in printed matter. Fig. 3 shows the problem when using tweezers in printed matter. Illustrate the problem of using common overlaps in printed matter. The problem with using a special overlap in printed matter is shown. 1 shows an overview of the anti-counterfeit printed matter of the present invention; FIG. 2 shows a configuration diagram of a printed image of a forgery-preventive printed matter of the present invention; FIG. 2 shows an enlarged view of an example of a printed image of a forgery-preventive printed matter of the present invention; 1 shows rules for composing printed images of anti-counterfeit printed matter of the present invention; 4 shows the high redundancy of printing in the forgery-preventive printed material of the present invention. An example of the effect of the anti-counterfeiting printed matter of the present invention is shown. FIG. 2 shows an enlarged view of an example of a printed image of a forgery-preventive printed matter of the present invention; FIG. 2 shows an enlarged view of an example of a printed image of a forgery-preventive printed matter of the present invention; FIG. 2 shows an enlarged view of an example of a printed image of a forgery-preventive printed matter of the present invention; An example of the change effect using the anti-counterfeit printed matter of the present invention is shown. 1 shows a method for creating a counterfeit-resistant printed matter of 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)
FIG. 5 shows an outline of the anti-counterfeit printed matter (1) of the present invention. The anti-counterfeit printed matter (1) of the present invention comprises a printed image (3) on a partial area on a substrate (2). In the forgery-preventive printed matter (1) according to the first embodiment, the printed image (3) is a flat image without shading, and has a configuration in which a colored pattern consisting of an aggregate of a plurality of circles is hidden as a latent image. An example will be described.

The color of the printed image (3) may be any color as long as it is not transparent. In the first embodiment, an example in which the print image (3) is composed of achromatic silver (gray) will be described. In FIGS. 5 to 7 of the first embodiment, the print image (3) is represented in a state in which a colored pattern consisting of an aggregate of a plurality of circles is visible, but this is easy to explain. The color pattern is visualized for the sake of convenience, and in reality, the color pattern is invisible in the printed image (3) because it is visually recognized in the same color as the surroundings. The substrate (2) to which the printed image (3) is applied may be any material as long as it accepts the printing ink. High-quality paper or coated paper may be used, and plastic or metal may be used as the base material (2).

FIG. 6 shows a block diagram of the print image (3). The printed image (3) comprises two images, a first image (4) and a second image (5). Due to the configuration of the present invention, in which the first image (4) is hidden in the second image (5) to make it invisible, the first image (4) and the second image (5) are visually At least the hues must be the same, since the color matching relationship must be established. As used herein, the term "hue" refers to a color aspect such as red, blue, or yellow, and specifically, it indicates a distribution of heights of specific wavelengths in the visible light region (400 to 700 nm). be. Light blue and dark blue have the same hue but different lightness, and yellow and green or red and blue have different hues. Further, in this specification, achromatic colors such as white, gray, and black are also considered as one hue. In addition, it must consist of colors of different lightness in order to satisfy the relationship between density and width equations described below. "Brightness" represents the brightness of a color, and is bright when high and dark when low. In the present invention, the brightness of the first image (4) should be low and the brightness of the second image (5) should be high. In addition, "color" represents color including the concepts of hue, saturation and lightness.

Since the present invention has the object of concealing the latent image, the first image (4) that constitutes the latent image and the second image (5) that forms a pair with it are formed from figures and characters that are latent images. , symbols, patterns, images, etc. must be provided.

The first image (4) and the second image (5) should comprise the same image in a negative-positive relationship. In the first embodiment, this same image corresponds to a colored pattern consisting of an aggregate of a plurality of circles. The second image (5) has a density adjustment element (5-2) of a color pattern expressed as a negative in a background element (5-1) having a constant density, and the first image (4) is composed of a latent image element (4-1), and the latent image element (4-1) or the background element (5-1) has inks with different functionality or different properties from each other. Formed with ink.

Examples of functional materials used in functional inks include bright pigments, pearl pigments, fluorescent pigments, colorless fluorescent pigments, phosphorescent materials, magnetic materials, infrared transmission materials, infrared absorption materials, and conductive materials. can give. "Different functionality" in the present invention means that the ink forming one of the first image (4) or the second image (5) has the above functionality and the other ink has the above functionality. A combination having no functionality (for example, a gray coloring pigment is used for the first image and a gray luster pigment is used for the second image), and among the functional materials shown above, A combination of different functional materials to form a first image (4) and a second image (5) (for example, a magnetic material is used for the first image (4), and a magnetic material is used for the second image (5) using an infrared absorbing material). Further, "different characteristics" in the present invention means that although the functionality of the inks forming the first image (4) and the second image (5) is the same, for example, the strength of the same magnetic material or the same luminescent material It refers to a combination that has a strong and weak relationship in

The "latent image" in the present invention can be identified by the difference in functionality or characteristics between the ink forming the first image (4) and the ink forming the second image (5). Note that the first image (4) or the second image (5) may be confirmed as the latent image, and there is no particular limitation. Means for confirming the latent image include an infrared camera, parallel line filter, discriminating device such as an optical sensor, visual observation from a predetermined angle, and the like.

In the present invention, the latent image element (4-1) is composed of image lines and pixels, the background element (5-1) is composed of image lines, pixels or solid colors, and the density adjustment element (5-2) is It consists of image lines and pixels with a lower density than the background element (5-1), solid paint, and blank areas that are non-printing areas. The term "element" in the present invention refers to an image line, a pixel, or a solid portion composed of small halftone dots, which are the smallest unit, forming the print image (3). An image line is a dotted or dashed dividing line, a straight line, a curved line, or a broken line in which halftone dots are continuously arranged at a certain distance in a specific direction. It refers to figures such as triangles, polygons including quadrilaterals, stars, etc., letters, symbols, numbers, etc. Note that FIG. 6 shows an example in which the latent image element (4-1) is an image line, the background element (5-1) is solid, and the density adjustment element (5-2) is white.

The latent image element (4-1) in the first image (4) has a shape that fits in the density adjustment element (5-2) of the second image (5), but its width and density (Brightness) is different. Specifically, the width (W ₄ ) of the latent image element (4-1) is narrower than the width (W ₅ ) of the density adjustment element (5-2), and the density is high (lightness is low). In addition, the density of the latent image element (4-1) of the first image (4) is higher (lower brightness) than the background element (5-1) constituting the second image (5). There is a need.
In this specification, the state of "fitting" means the state in which the latent image element (4-1) is arranged in the white density adjustment element (5-2), or the state in which the latent image density (4-1) is placed on the density adjustment element (5-2) having a lower density than the background element (5-1), and the latent image element (4-1) is placed on the density adjustment element (5- 2) refers to the state included in the range of the width.

FIG. 7 shows enlarged views of the positional relationship of the respective image elements when the first image (4) and the second image (5) are printed together to form the printed image (3) in a front view and a cross-sectional view. show. The ideal alignment is a positional relationship in which the center of the latent image element (4-1) fits in the center of the density adjustment element (5-2) as shown in FIG. In the first embodiment, the density adjusting element (5-2) has a white structure, and the latent image element (4-1) is arranged on the density adjusting element (5-2).

Here, the relationship between the density and width of each element in the first image (4) and the second image (5) will be specifically shown. Let the density of the latent image element (4-1) in the first image (4) be (A ₄ ) and its width be (W ₄ ). Also, if the density of the background element (5-1) is (A ₅ ), the density of the density adjustment element (5-2) is (A ₀ ), and the width is (W ₅ ), paragraph number 0030 By designing the respective densities and widths so that the following formulas (i), (ii), (iii), and (iv) hold, it is possible to cope with large misalignments, even when you want to hide thin and sharp elements. A usable element for concealing the latent image of the present invention can be constructed. Formulas (i), (ii), (iii), and (iv) shown in paragraph number 0030 are for establishing a color matching relationship between light and thick elements and dark and thin elements, and fine lines On the other hand, by converting light and thick lines into dark and thin elements, redundancy is ensured against printing misalignment while maintaining visual color matching.

Equation (i): Density of latent image element ₍ A4) x Width of latent image element ( _W4 )
= (Density of background element (A ₅ ) - Density of density adjustment element (A ₀ )) x Width of density adjustment element (W ₅ )
Equation (ii): Width of density adjustment element (W ₅ )>width of latent image element (W ₄ )
Formula (iii): density of background element (A ₅ ) > density of density adjustment element (A ₀ )
Equation (iv): density of latent image element (A ₄ )>density of background element (A ₅ )

The density adjustment element (5 -2) and the latent image element (4-1) are visually recognized as the same density as the background element (5-1). looks like an image. In this case, as shown in FIG. 8, misregistration by the width obtained by subtracting the width (W ₄ ) of the latent image element (4-1) from the width (W ₅ ) of the density adjustment element (5-2). is allowed. If the density of the latent image element (4-1) is high and the density of the density adjustment element (5-2) is low, the width of this permissible misregistration will increase.

Even when the relationships of the above-described formulas (i), (ii), (iii), and (iv) are all satisfied, if the width (W ₅ ) of the density adjustment element (5-2) is too large, The design of the latent image element (4-1) is visually recognized. This reduces the opacity of the latent image element (4-1). The width (W ₅ ) of the density adjusting element (5-2) should be 500 μm or less, more preferably 400 μm or less.

Suppose that the density (A ₄ ) of the latent image element (4-1) is 1.5, the density (A ₀ ) of the density adjustment element (5-2) is 0, and the density (A ₅ ) is 0.3 and the width (W ₅ ) of the density adjustment element (5-2) is 400 μm, the width (W ₄ ) of the latent image element (4-1) is 80 μm. In this case, the difference between the width (W ₅ ) of the density adjustment element (5-2) and the width (W ₄ ) of the latent image element (4-1) is 320 μm, and a misregistration of about ±160 μm is allowed. becomes. This corresponds to about three to four times the allowable range of misregistration allowed in the conventional overlap. The allowable width for such a large misregistration is unparalleled. In addition, sharp elements can be represented because the latent image element (4-1) does not need to be enlarged. It can be said that it is an extremely excellent composition for hiding small elements.

When this configuration is used, even if the latent image element is printed in the center of the density adjustment element (5-2) without misalignment as shown in FIG. As shown in b), even when printing is misaligned, no visual density change occurs in any case. Moreover, the allowable amount of misregistration is extremely large compared to the conventional technology. As described above, by using the configuration of the anti-counterfeiting printed matter (1) of the present invention, it is possible to completely solve the problems caused by using conventional fitting and overlapping.

An example of the effects of the present invention will be described with reference to FIG. The first image (4) is composed of matte black ink and the second image (5) is formed of glossy silver ink and represented by the formulas (i), (ii), (iii), ( iv) is formed, and the anti-counterfeiting printed matter (1) of the present invention is formed so that the angle of incident light from the light source (6) and the angle of reflected light are as shown in FIG. 10(a). When observed (7) at a significantly different observation angle in which so-called diffusely reflected light is dominant, the printed image (3) is viewed as a flat image without shading. In this case, the latent image is invisible. Observe the anti-counterfeit printed matter (1) at an observation angle where the so-called specular reflection light is dominant, where the angle of the incident light from the light source (6) and the angle of the reflected light are the same as shown in FIG. 10(b). In the case of (7), a colored pattern, which is a latent image that the first image (4) appears, can be confirmed in the printed image (3). The reason why this effect occurs is that under diffusely reflected light, the first image (4) and the second image (5) are visually recognized in the same color, so the latent image is invisible, while the specularly reflected light This is because the latent image was visualized below due to the difference in reflectance between the first image (4) and the second image (5).

As described above, when the configuration of the anti-counterfeiting printed matter (1) of the present invention is used, not only can the first image (4) be easily hidden in the second image (5), but also misalignment of the printing can be prevented. The allowable amount of printing reaches 3 to 4 times that of conventional printing technology. If there is a redundancy of misalignment of this magnitude, it is possible to produce printed matter that requires latent image concealability not only by a sheet-fed printing press but also by using a web printing press. In addition, when manufacturing a product with multiple patterns laid out on large size paper, even if there is expansion and contraction of the plate surface, expansion and contraction of the base material due to pressure applied during printing, and uneven printing elongation during printing, there is no printing failure. You can get a print.

(Modification 1: Example in which latent image elements and background elements are pixels)
FIG. 11 shows an example in which the latent image elements (4-1) and the background elements (5-1) forming the print image (3) are shown in pixels. In addition, in FIG. 11, a square pixel is shown as an example of an element. In FIG. 11, the printed image is visually recognized as a flat image without shading when observed at an observation angle where diffusely reflected light is dominant. Also, the significant information in the print image (3) indicates "H".
The first image (4) has the latent image elements (4-1) in a first direction (S1) at a first pitch (P1) and further in a second direction (S2) at a first are arranged at a pitch (P1) of .
In the second image (5), the background element (5-1) of width (W _5-1 ) is arranged in the same direction (S1, S2) and at the same pitch (P1) as the latent image element (4-1). A plurality of them are arranged in a matrix. The density adjustment elements (5-2) are arranged at the same pitch (P1) as the latent image elements (4-1) to fit with the latent image elements (4-1). The latent image element (4-1), the background element (5-1), and the density adjustment element (5-2) are configured to satisfy the above-described formulas (i), (ii), (iii), and (iv). ing. Specifically, the width (W _4-1 ) of the latent image element (4-1) is narrower than the width (W _5-2 ) of the density adjustment element (5-2), and the width (W 5-2 ) of the latent image element (4-1) is The density (A ₄ ) is higher than the density (A ₅ ) of the background element (5-1).

(Modification 2: Example in which latent image elements and background elements are image lines)
FIG. 12 shows an example in which the latent image element (4-1) and the background element (5-1) that make up the print image (3) are shown by lines. Note that the significant information in the print image (3) in FIG. 12 indicates a regular hexagon.
A first image (4) is formed by arranging a plurality of latent image elements (4-1) in a first direction (S1) at a first pitch (P1). The second image (5) is composed of a plurality of background elements (5-1) arranged at the same pitch (P1) in the same direction (S1) as the latent image elements (4-1). The density adjustment elements (5-2) are arranged at the same pitch (P1) as the latent image elements (4-1) to fit with the latent image elements (4-1). The latent image element (4-1), the background element (5-1), and the density adjustment element (5-2) are configured to satisfy the above-described formulas (i), (ii), (iii), and (iv). ing. Specifically, the width (W _4-1 ) of the latent image element (4-1) is narrower than the width (W _5-2 ) of the density adjustment element (5-2), and the width (W 5-2 ) of the latent image element (4-1) is The density (A ₄ ) is higher than the density (A ₅ ) of the background element (5-1).

(Second embodiment)
Unlike the first embodiment, the density adjustment element (5-2) is white, that is, the density (A ₀ ) is set to zero. As a second embodiment, a configuration in which the concealability of the latent image is enhanced more easily by giving a constant density to the density adjustment element (5-2) will be described as a second embodiment. The second embodiment differs from the first embodiment only in the density of the image line of the density adjustment element (5-2) of the second image (5). Since other configurations are the same as those of the first embodiment, description thereof is omitted.

For example, as shown in FIG. 13, assume that the density (A ₅ ) of the background element (5-1) is 0.3, the density (A ₀ ) of the density adjustment element (5-2) is 0.1, and the density adjustment When the width (W ₅ ) of the element (5-2) is 400 μm and the width (W ₄ ) of the latent image element (4-1) is 80 μm, applying the above formula, the latent image element (4-1) has a density (A ₄ ) of 1.0. In this case, the density difference between the density adjusting element (5-2) and the latent image element (4-1) becomes small and the difference becomes less conspicuous. Since the latent image of (4-1) overlaps and mixes colors, the density adjustment element (5-2) is white, and the latent image element (4-1) composed of a single ink is shown in the same color. Concealment of the latent image becomes easier than in the example of the first embodiment.

However, the configuration in which the density adjustment element (5-2) and the latent image element (4-1) are superimposed as in the second embodiment is not suitable for a pair of magnetic inks with or without magnetism, or for infrared absorption characteristics. The printed image (3) of the present invention is constructed using paired inks with and without the presence of the latent image element (4-1) in an attempt to detect differences in magnetic and infrared absorption properties between the latent image element (4-1) and other areas. Care must be taken when applying to printed matter with a certain functionality. This is because in the second embodiment, since the latent image element (4-1) and the density adjustment element (5-2) are superimposed, the functionality of each ink is mixed.

In the second embodiment, magnetic ink is used for the first image (4), and non-magnetic ink is used for the second image (5). It is necessary to limit the configuration to use an ink having infrared absorption properties for the ink forming the first image (4) and an ink having no infrared absorption properties for the ink forming the second image (5). When using the configuration of the anti-counterfeiting printed matter (1) of the second embodiment, the presence or absence of functionality may be mixed, making it difficult to determine functionality. It is necessary to use them properly.

Further, although the printed image (3) in both the first embodiment and the second embodiment has been described as a flat image without shading, it is not limited to this. As shown in FIG. 14, there is no problem in using a configuration in which specific significant information (letter "A" in the example of FIG. 14) is visible in the printed image (3) under visible light. Regarding the basic configuration for adding a visible image in such a printed image (3), a latent image described in Japanese Patent No. 6216972, Japanese Patent Application Laid-Open No. 2017-100331, etc. is added to the visible image. is applied to the first image (4) of the present invention.

As described above, the first image (4) and the second image (5) were obtained by using the paired inks having the same hue and different lightness, and using the above-described formulas (i), (ii), (iii), and (iv). By forming and printing according to the conditions of 1, it is possible to ensure redundancy in printing that could not be achieved by conventional printing with tweezers or overlap.

(Third Embodiment)
A method for producing the anti-counterfeiting printed matter (1) in the present invention will be described. The anti-counterfeit printed matter (1) produced in the third embodiment is the same as that in the first embodiment, so the description is omitted. The forgery-preventive printed matter (1) to be produced will be described using the configuration of FIG. 6 described in the first embodiment as an example.

FIG. 15 is a flow chart showing the procedure of the production process of the anti-counterfeit printed matter (1) in the present invention. Hereinafter, a detailed description will be given of the method for producing the anti-counterfeit printed matter (1) according to this figure.

The image setting step is a step of setting a basic image by directly inputting the basic image that is the basis of the visible image and the latent image, or taking in the basic image from the outside or from a registered database.

The image conversion step converts the original image data into a positive first image (4) and a negative second image (5), and converts the first image (4) to be a latent image into at least one image. In the step of forming one or more latent image elements (4-1) and forming the second image (5) as a white background or a density adjustment element (5-2) having a color lighter than that of the first image (4) be. These processes can be performed using image processing software.

The image adjustment step includes adjusting the density (A ₄ ) and width (W _4-1 ), the density (A ₅ ) of the background element (5-1), and the density (A ₀ ) and width (W ₅ ) of the density adjustment element (5-2). Note that the width (W _4-1 ) of the latent image element (4-1) must be set narrower than 500 μm. This is because when the width (W ₄ ) of the latent image element (4-1) exceeds 500 μm, the difference between the latent image element (4-1) and the density adjustment element (5-2) is perceived by the observer, and the latent image This is because the image is recognized.

Equation (i): Density of latent image element ₍ A4) x Width of latent image element ( _W4 )
= (Density of background element (A ₅ ) - Density of density adjustment element (A ₀ )) x Width of density adjustment element (W ₅ )
Equation (ii): Width of density adjustment element (W ₅ )>width of latent image element (W ₄ )
Formula (iii): density of background element (A ₅ ) > density of density adjustment element (A ₀ )
Equation (iv): density of latent image element (A ₄ )>density of background element (A ₅ )

The image printing process prints a first image (4) with an ink having a functionality or property that is observable under certain conditions, and a second image (5), when printed, under diffuse light, etc. This is a process of printing with ink that is visually recognized as a color and has different functionality or characteristics than the functionality. The colors and densities of the first image (4) and the second image (5) are not particularly limited, but the first image (4) and the second image (5) are visually At least the hues must be the same because the equivalence relationship of must hold. As for the printing method, offset screen gravure or the like can be used.

(Example)
Forgery-preventive printed matter (1) will be described as an example. FIG. 5 shows the anti-counterfeit printed matter (1) in the embodiment. A white matte lightly coated paper (Gladios CC, manufactured by Nippon Paper Industries) was used for the base material (2). The ink that forms the first image (4) is a gray offset ink (UVL P Cool Gray 8U (manufactured by T&K TOKA)) that is close to black, and the ink that forms the second image (5) is an offset ink. A printed image (3) is formed by wet offset printing using a silver ink (TKSO silver (manufactured by T&K TOKA)) and using an offset proof printing machine. Both of these two inks have a black to gray hue, and the silver ink has a higher brightness than the gray ink.

The density (A ₄ ) of the latent image element (4-1) of the first image (4) was 0.4 and the width (W ₄ ) was 75 μm. For the second image (5), the density A ₅ of the background image (5-1) is set to 0.15 in terms of reflection density, and the density (A ₀ ) of the density adjustment element (5-2) is set to 0.15 in terms of reflection density. 05, and the width (W ₅ ) was 300 μm. Since the difference in element width between the first image (4) and the density adjustment element (5-2) of the second image (5) is 225 μm, it is possible to provide an allowance for printing alignment of approximately ±113 μm. did it.

The effect of anti-counterfeit printed matter (1) produced with such a configuration was confirmed. As shown in FIG. 10, when the printed image (3) of the anti-counterfeiting printed material (1) of the present invention was viewed under diffusely reflected light, the latent image (4) was not visible. On the other hand, when the printed image (3) of the anti-counterfeiting printed material (1) of the present invention was viewed under specularly reflected light, the color pattern, which is a latent image, was visually recognized depending on the intensity of the reflected light. As described above, the effect of concealing the latent image in the anti-counterfeiting printed matter (1) of the present invention was confirmed. In addition, although printing was performed by intentionally changing the alignment of the two patterns within a range of about ±100 μm, the colored pattern, which is the latent image (4), was not visualized. As described above, it was confirmed that redundancy for printing was also ensured.

1 anti-counterfeit printed matter 2 substrate 3 printed image 4 first image 4-1 latent image element 5 second image 5-1 background element 5-2 density adjustment element 6 light source 7 viewpoint A first image printed layer B Printed layer C of the second image Area D of the first image overlapping the second image Area of the first image overlapping the second image

Claims (2)

a printed image comprising a first image and a second image interlaced in a negative-positive relationship on at least a portion of the substrate;
The first image and the second image are formed with two inks that are visually recognized as matching colors when observed under diffused light,
one of the inks forming the first image and the second image has different functionality or different properties relative to the other ink;
Although it is not visible under diffused light, under certain viewing conditions, the first image or the An anti-counterfeit printed matter in which the second image is observable as a latent image,
the first image comprises at least one or more latent image elements;
The second image is composed of a white background or a density adjustment element of a color lighter than the color of the ink forming the latent image, and at least one or more background elements,
The density of the background element is _A5 , the density of the density adjustment element is _A0 , the width of the density adjustment element is _W5 , the density of the latent image element is _A4 , and the width of the latent image element is A forgery _- preventive printed material that satisfies all the conditions of the following formulas (i), (ii), (iii), and (iv) when W4.
Formula (i): (density of the background element (A ₅ )−density of the density adjustment element (A ₀ ))×width of the density adjustment element (W ₅ )=density of the latent image element (A ₄ )× the width of the latent image element ( _W4 );
Formula (ii): Width of density adjustment element (W ₅ )>width of latent image element (W ₄ )
Formula (iii): Density of the background element (A ₅ )>Density of the density adjustment element (A ₀ )
Equation (iv): Density of the latent image element (A ₄ )>Density of the background element (A ₅ ) 1. A method of making an anti-counterfeit printed product comprising a printed image consisting of a first image and a second image on a substrate, comprising:
an image setting step of setting basic image data of the print image;
converting the original image data into a positive first image and a negative second image, forming the first image with at least one or more latent image elements, and forming the second image; an image conversion step of forming as a white background or a density adjustment element having a color lighter than that of the first image, and at least one or more background elements;
Let A ₄ be the density of the latent image element, W ₄ be the width of the latent image element, A ₅ be the density of the background element, A ₀ be the density of the density adjustment element, and W be the width of the density adjustment element. ₅ , an image adjustment step of adjusting so as to satisfy all the conditions of the following formulas (i), (ii), (iii), and (iv);
One of the first image and the second image is printed with ink having functionality or characteristics that allows observation as a latent image under specific viewing conditions, and when the other image is printed, the and an image printing step of printing with an ink that is visually recognized as having the same color as the ink having the functionality or the characteristics and has a functionality different from the functionality or a characteristic different from the characteristics. A method for producing anti-counterfeit printed matter.
Formula (i): (density of the background element (A ₅ )−density of the density adjustment element (A ₀ ))×width of the density adjustment element (W ₅ )=density of the latent image element (A ₄ )× the width of the latent image element ( _W4 );
Formula (ii): Width of density adjustment element (W ₅ )>width of latent image element (W ₄ )
Formula (iii): Density of the background element (A ₅ )>Density of the density adjustment element (A ₀ )
Equation (iv): Density of the latent image element (A ₄ )>Density of the background element (A ₅ )

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