JP5920781B2 - Latent image printed matter - Google Patents

Description

  INDUSTRIAL APPLICABILITY The present invention can be observed under diffuse reflected light in the field of valuable printed matter such as banknotes, passports, securities, identification cards, cards, and passports, which are security printed matters that require an anti-counterfeit effect. The image relates to a latent image printed matter that changes to a completely different image when observed under specular reflection light.

  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 complicated manufacturing processes and special materials, making it more laborious to manufacture than conventional anti-counterfeit printed matter. And is very 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, a forgery-preventing printed matter that can be formed by a general printing method, which realizes an image change similar to a hologram, has appeared.

  Although 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 is observed at a specific observation angle. There have already been applied for inventions related to an information carrier for preventing counterfeiting that changes to completely different information by changing the angle (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

Japanese Patent No. 3398758 Japanese Patent No. 4604209 JP2011-218655A

  However, regarding the technique of Patent Document 1, the glitter material layer having the extremely high area ratio formed using the glitter material constituting the first print image and the glitter constituting the second print image. Appropriate area that looks the same color (approximate color) in the diffused light region by superimposing color material layers with a very low area ratio formed using a color material with a higher visible light absorption than the light-sensitive material We must determine the density difference. Since an image is formed by overlaying a color material layer with a color tone different from that of the glitter material layer on the glitter material layer, the type and area ratio of the color material having high visible light absorption can be changed in various ways. It took a great deal of effort to determine the appropriate conditions for obtaining the optimal switchability from the first print image to the second print image. In addition, even a printed matter formed with such a great amount of labor has a problem in that a latent image that should not be visualized is slightly visible in observation under diffuse reflected light.

  The technique described in Patent Document 2 is a technique for forming an anti-counterfeit printed material by superimposing a glitter material and transparent ink. Unlike the technique of Patent Document 1 using a color material for forming a latent image, a latent image is formed. Since the ink to be formed is transparent, there is no need for color adjustment in the first place, and the latent image is not visualized under diffuse reflected light, and this is a technique that can obtain high image switchability. However, although this technique can realize an extremely excellent switching effect when printed on coated paper, there is a problem that the switching effect becomes unclear when printed on high-quality paper.

  For example, as shown in FIG. 9, the letter “A” of the alphabet, which is the visible image (8) shown in FIG. 9A, is formed with ink containing a glittering material (for example, gold ink), and on that, When the letter “B” of the alphabet, which is the latent image (9) shown in FIG. 9B, is formed with a transparent, low-gloss ink, the coated paper is used for observation under diffuse reflected light. The letter “A” of the alphabet is visually recognized in the same way, even when the material is used, or when a high-quality paper with low smoothness is used as the base material. However, in observation under specular reflection light, when coated paper is used as a base material, only the alphabet “B” as a latent image is visually recognized as shown in FIG. 9C (10A). However, when fine paper is used as the base material, as shown in FIG. 9D, the alphabet “A” of the visible image (8) is placed inside the alphabet “B” of the alphabet as a latent image. Characters overlap and appear (10B). As described above, there is a problem that the switch effect is greatly influenced by the substrate to be printed.

  Further, when forming the technique described in Patent Document 1 or Patent Document 2 using fine paper as a base material, the visible image (8) is formed using a metallic ink such as gold or silver having a relatively low color density as it is. In general, it was difficult to change the color of the visible image (8) greatly by mixing a metallic pigment with a color pigment such as red, blue, or black. This is because when the visible image (8) is designed by mixing color pigments, the glitter is relatively lowered and the image changing effect is lowered. Therefore, when forming the technique of Patent Document 2 using high-quality paper as a base material, there is a problem that the variation in the color of the visible image (8) becomes poor and the degree of freedom in design is low.

  The technique described in Patent Document 3 has been proposed in order to solve the problems of the techniques described in Patent Document 1 and Patent Document 2, and a low-smooth and low-gloss paper such as high-quality paper is used as a printing substrate. Even if it is used as a material, it can achieve an excellent image change effect, and the color can be changed by mixing colored pigments such as red, blue, and black with the metallic pigment that forms the first image (visible image) It is an excellent technology that can. However, as in the technique described in Patent Document 1, the technique described in Patent Document 3 needs to match the first image and the second image with high accuracy. Specifically, the second element constituting the second image must not be superimposed on the information element constituting the first image, but on the background element constituting the first image. It was necessary to overlap. Printing the second element made of transparent material with high precision is a heavy burden on the printing operator, and special equipment and ingenuity and strict attention are required to produce stable quality products. Etc. were necessary.

  The present invention aims to solve the above-mentioned problems, and is a printed matter formed by overlaying a visible image containing a glittering material on a latent image having a higher gloss than that of a substrate, It has a so-called image change effect that changes to an uncorrelated image under diffuse reflected light and regular reflected light, and even if it is made of any material including general fine paper as a base material The present invention relates to a latent image printed material having an excellent change effect that does not deteriorate, does not require high printing accuracy, is easy to design and manufacture, and is inexpensive.

  The latent image printed material according to the present invention includes a printed image area at least at a part on the substrate, and the printed image area is formed of a material having high glossiness and is transparent or the second significant information of the same color as the substrate. The visible image having the first significant information of a color different from that of the base material formed of the material including the glittering material is laminated on the latent image having the same size as the visible image. The visible image is formed with a difference between the maximum area ratio and the minimum area ratio in the visible image of 10% or more and 75% or less, and observed under diffuse reflected light. In this case, the first significant information can be visually recognized, and when observed under specular reflection light, the first significant information disappears because the visible image reflects light strongly, and the glossiness of the base material is reduced. The second significant information can be visually recognized by emphasizing the difference.

  The latent image printed material according to the present invention is characterized in that the difference in glossiness between the base material and the latent image is 5 or more in terms of 75 ° specular gloss (JIS P8142).

  In the latent image printed matter of the present invention, a so-called image change effect in which an image visible when observed under diffused light in a printed image changes to a different image that has no correlation when observed under specular reflection light. Have This change effect is relatively high compared to the prior art, and even if any material including fine paper is used as the base material, the change effect is not greatly reduced as in the prior art, and a colored pigment is used. Even if the color of the visible image is changed, the effect is not lost. Therefore, it is possible to form a latent image having a high degree of design freedom and excellent authenticity.

  The two images, the visible image and the latent image, do not require strict printing as in the prior art, and may simply overlap each other. Moreover, if the color adjustment of each image, the management of dot gain, etc. are managed to the same extent as general printed matter, the quality will be sufficiently stabilized. Therefore, the difficulty of manufacture is low and stable continuous manufacture is possible.

  The latent image printed matter formed by the above method can be manufactured by offset printing, which is a highly productive printing method, so that it is excellent in cost performance, and even if the latest digital equipment is used, the image change effect is excellent. Since reproduction is impossible, it is excellent in anti-counterfeiting effect.

The latent image printed matter in this invention is shown. The outline | summary of a structure of the latent image printed matter in this invention is shown. The superimposition order of two images of a latent image printed matter is shown. (A) shows an image that can be visually recognized when the latent image printed material of the present invention is observed under diffused light, and (b) shows an image that can be visually recognized when the latent image printed material of the present invention is observed under regular reflection light. . An example of the structure of the visible image of this invention is shown. 1 shows a latent image printed material according to an embodiment of the present invention. 1 shows an outline of a configuration of a latent image printed material according to an embodiment of the present invention. (A) shows an image that can be seen when the latent image printed material in one embodiment of the present invention is observed under diffused light, and (b) is visible when the latent image printed material in the present invention is observed under specular reflection light. The possible images are shown. Some of the problems to be solved by the present invention are shown below.

  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.

  FIG. 1 shows a latent image printed material (1) according to the present invention. The latent image printed material (1) includes a printed image region (3) having a color different from that of the substrate (2) on the substrate (2). The substrate (2) may be paper, plastic, metal or the like as long as the print image region (3) can be formed, and the material is not limited.

  Further, the size of the print image region (3) is not limited as long as it fits in the base material (2). In addition, although the letter “B” of the alphabet is visible in the print image area (3) shown in FIG. 1, it is actually invisible.

  First, FIG. 2 shows the configuration of the print image area (3) in the present invention. The print image area (3) includes a visible image (4) having first significant information and a latent image (5) having second significant information. In the present embodiment, a description will be given in a form in which the images included in the visible image (4) and the latent image (5) are simple binary images expressed by two different shades of color. In the description of the present embodiment, the first significant information refers to the letter “A” of the alphabet, and the second significant information refers to the letter “B” of the alphabet.

  The visible image (4) has a color different from that of the base material (2) depending on the material containing the glittering material, and the visible image (4) is formed with a gradation expression range of 10% to 75%. Need to be done. That is, the difference between the maximum area ratio and the minimum area ratio in the visible image (4) is 10% to 75%.

  For example, when the maximum area ratio in the visible image (4) is 100%, the minimum area ratio needs to be 25% or more and 90% or less, and the minimum area ratio in the visible image (4) is 10%. In this case, the maximum area ratio needs to be 20% or more and 85% or less.

  In addition, it is desirable to avoid the so-called nuckle region having an area ratio of 0% in the visible image (4) because the disappearance effect of the visible image (4) during regular reflection is greatly reduced.

  The latent image (5) needs to be transparent or the same color as the substrate (2), and have a relatively higher gloss than the substrate (2). The base material (2) and the same color indicate white when the base material (2) is white, and skin color when the skin color is skin color. Moreover, the difference in glossiness in a state where the glossiness is relatively higher than that of the substrate (2) will be described later.

  The latent image (5) is not limited with respect to the gradation representation area of the image, and may be configured with a gradation representation area of 100%. That is, there is no problem even if a region with an area ratio of 0% and a region with an area ratio of 100% exist in the image.

  Note that the glittering material referred to in the present specification refers to a material that generates strong specularly reflected light when light is incident thereon, and brightness or dark flip-flop properties that increase brightness (change lightly) by specular reflection, It refers to a material having either or both of color flip-flop properties in which the hue is changed by regular reflection (the color changes).

  Specific glittering materials having light and dark flip-flop properties include common metal powder pigments such as aluminum powder, copper powder, zinc powder, tin powder, brass powder or iron phosphide, and color flip-flops. Examples of the glittering material having properties include general pearl pigments such as iris pearl pigments and scaly pigments, and functional pigments such as glass flake pigments and cholesteric liquid crystal pigments. Since the visible image (4) of the present invention needs to reflect light at the time of regular reflection and change lightly or change its hue, it is necessary to include these glittering materials.

  There is no problem even if the visible image (4) contains a coloring pigment in addition to the glittering material. There is no problem even if the color of the color pigment is any color such as black, red, blue and yellow. However, when an excessive amount of pigment is mixed, even if the visible image (4) is formed in the range of the appropriate gradation expression range, the difference in light and shade in the image becomes too large, or the content of the glittering material As a result, the first significant information in the visible image (4) is not completely lost in observation under specular reflection light. Therefore, when 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.

  As described above, the difference between the maximum area ratio and the minimum area ratio in the visible image (4) is 10% to 75%. This is because when the difference in area ratio exceeding 75% is provided in the visible image (4), the density difference in the visible image (4) becomes too large, and the first significant information disappears during regular reflection. This is because the effect is remarkably reduced. In this case, the first significant information does not disappear even in observation under specular reflection light, and appears overlapping with the second significant information. Therefore, the visible image (4) has an area ratio exceeding 75%. It is not desirable to make a difference. Further, when the difference between the maximum area ratio and the minimum area ratio in the visible image (4) is less than 10%, a sufficient shade difference cannot be formed in the visible image (4), and the first significant information This is not desirable because the visibility becomes low and it is difficult to easily determine.

  One latent image (5) needs to have a gloss level relatively higher than that of the substrate (2). The greater the difference in glossiness from the substrate (2), the higher the visibility of the second significant information that appears during regular reflection. Gloss varnish, OP varnish or the like may be used as such a transparent printing material having a high glossiness, and as a printing material having the same color as the substrate (2), when the substrate (2) is white, white If the base material (2) is flesh-colored, a flesh-colored color ink may be used. In the case of white colored ink, higher effects can be achieved by using an ink containing titanium.

  If the latent image (5) is formed using colored ink, it is necessary to check the color every time so that the latent image (5) becomes invisible under diffuse reflected light. In order to increase the relative gloss difference with the substrate (2), it is desirable to transfer a large amount of ink. As a specific difference in glossiness, it is desirable that the glossiness is 5 or more at 75 ° specular gloss. A glossiness lower than 5 is not desirable because the visibility of a latent image that appears under specular reflection light decreases. There are a plurality of apparatuses for measuring the glossiness, and the numerical value of the glossiness varies depending on the apparatus. Therefore, the 75 degree specular glossiness in the measurement of the glossiness in this specification is based on JIS P8142 (measuring method of paper and paperboard 75 degree specular gloss).

  There are no particular restrictions on the fine structure of the significant information that the visible image (4) and the latent image (5) have, and any structure can be used as long as the light and shade can be expressed by its size and density. Good. In the case of using halftone dots, either an AM screen or an FM screen may be used. Further, there is no problem even if the significant information of the visible image (4) and the latent image (5) is configured using an image line formed by collecting halftone dots, pixels, or the like. In addition, there is no restriction on the positional relationship between the halftone dots. The above is the outline of the configuration of the print image area (3) of the present invention.

  The “halftone dot” in the present invention is a small point of a minimum unit for forming a printed image. These are dotted lines, broken lines, broken lines, straight lines, curved lines, and broken lines arranged continuously at a certain distance in a specific direction, and at least one printing halftone dot or a plurality of printing halftone dots are collected into a lump. Pixels include various figures such as a triangle, a polygon including a quadrangle, and a star, or letters, symbols, and numbers.

  FIG. 3 shows the overlapping order of the visible image (4) and the latent image (5) in the print image area (3). The visible image (4) and the latent image (5) included in the print image area (3) must be formed below the latent image (5). Regarding the superposition of two images, it is only necessary for the images to overlap each other, and high-precision printing as in the prior art is not necessary.

  However, the size of the areas in the print image area (3), the visible image (4), and the latent image (5) has a relationship of print image area = visible image ≧ latent image.

  The effect of the latent image printed material (1) formed as described above will be described with reference to FIG. As shown in FIG. 4 (a), the light source (6), the latent image printed matter (1), and the observer (7a) as shown in the diagram showing the positional relationship between the diffusely reflected light (the angle of light incident on the printed matter) When the latent image printed material (1) is observed in a situation where the angle connecting the observer and the printed material is greatly different, there is almost no specular reflection light and diffuse reflection light is dominant, the observer (7a ), The letter “A” of the alphabet, which is the first significant information shown in FIG.

  Further, as shown in FIG. 4B, the light incident on the printed material (under the incident light on the printed material) as shown in the diagram showing the positional relationship among the light source (6), the latent image printed material (1), and the observer (7b). When the latent image printed material (1) is observed in a situation in which the angle between the image and the angle between the observer and the printed material is close and the specularly reflected light is dominant), the observer (7b) The letter “B” of the alphabet as the second significant information shown in 4 (b) is visually recognized.

  Note that the image appearing under specular reflection light is an image in which the density of the second significant information included in the latent image (5) is inverted. Therefore, the latent image (5) needs to be an image obtained by reversing the density of an original image intended to be viewed under regular reflection light.

  Here, the principle of image change in the present invention will be described, and in addition, even when the printed image area (3) of the present invention is formed using the base material (2) as a high quality paper, The reason why a phenomenon in which significant information and second significant information are mixed does not occur will be described below.

  The basic principle of changing the image of the present invention at the time of regular reflection is the same as the technique described in Patent Document 1 to Patent Document 3. That is, the visible image (4) formed including the glittering material changes lightly during regular reflection, and the first significant information disappears visually by compressing the shade, while the latent image (5) Since the relative gloss difference existing between the image and other regions is more emphasized under specular reflection light, the second significant information is visualized by the intensity of specular reflection light. The above-described principle produces an image change effect.

  The largest difference in image configuration between the present invention and the prior art is the difference in the stacking order of the two images. Even if the same principle is used due to the difference in the stacking order of the images, there is a great difference in effect.

  Each of the conventional techniques is configured to superimpose the latent image (5) on the visible image (4) formed of the glittering material. In this case, the latent image (5) exists below the latent image (5). It acts to suppress regular reflection light generated from the visible image (4). That is, the specular reflection light in the region where the latent image (5) is present is reduced, and the specular reflection light in the region where the latent image (5) is not present. The latent image (5) was visualized by the intensity of the regular reflection light generated by this.

  This conventional configuration basically visualizes significant information of the latent image (5) by not changing the image below the latent image (5) (not changing the image lightly). When the brightness of the image (4) is not sufficient, or when the base material (2) is a high-quality paper that hardly generates specular reflection light, the latent image (9) as shown in FIG. There is a problem that the shade of the visible image (8) is reflected in the area with a high area ratio.

  On the other hand, in the present invention, the visible image (4) formed of a glittering material is superimposed on the latent image (5) having a higher gloss than that of the substrate (2). In this case, the latent image (5) does not suppress the specular reflection light of the visible image (4) existing thereon, as in the prior art, but conversely increases the volume. For this reason, the amount of specular reflection in the area without the latent image (5) is as strong as in the prior art, but the amount of specular reflection in the area with the latent image (5) is specular in the area without the latent image (5). It becomes much stronger than the amount of light.

  In the prior art, the area where the area ratio of the latent image (9) is high has a small amount of reflected light. In the present technique, the area where the area ratio of the latent image (5) is high is conversely large in the amount of reflected light. have.

  Therefore, it is unrelated to the problem that the density of the visible image (8) is reflected in the area having a high area ratio of the latent image (9) as shown in FIG. 9 (d), and the disappearance of the visible image (4). The effect is relatively higher than the prior art. Therefore, even when the high-quality paper that does not generate regular reflection light is used as the base material (2), the image change effect is not lost.

  The method for printing the visible image (4) and the latent image (5) having the above performance may be any printing method. The latent image printed material (1) of the present invention exhibits a sufficient effect even when formed by offset printing, but may be formed by flexographic printing, gravure printing, letterpress printing, intaglio printing, screen printing, or the like. When productivity is important, it is desirable to form by offset printing.

  The visible image (4) and the latent image (5) are functional materials such as luminescent pigments such as fluorescent pigments, phosphorescent pigments and phosphorescent pigments, IR absorbing pigments, IR reflecting materials, photochromic pigments, temperature indicating materials, and thermochromic materials. In this case, various functionalities can be added in addition to the image change effect.

  Here, the 1st significant information which the visible image (4) has is demonstrated. If the first significant information is a photograph such as a human image or a landscape, a visible image (4) can be formed using only the first significant information, but the first significant information represents characters or marks. In the case of a simple image, the visible image (4) cannot be formed with only the first significant information, and it is necessary to form a background region around the first significant information. The reason will be specifically described with reference to FIG.

  In order to realize the change effect of the present invention, first, it is necessary to compress the shading in the visible image (4) during regular reflection and to make the first significant information in the visible image (4) invisible to the observer. is there. The density is compressed in a state where the contrast between the first significant information in the visible image (4) and its surroundings is reduced during regular reflection.

  However, as in the example shown in FIG. 5A, the first significant information of the visible image (4 ′) is a simple image representing characters and marks, and the visible image (4 ′) is the first image. Even if the visible image (4 ') is specularly reflected and the density in it is compressed, the observer can only reduce the density of the visible image (4'). The first significant information can be easily read. This is because even if the shade inside the visible image (4 ′) is lost, the difference in hue and shade remains between the base material (2 ′) and the silhouette of the visible image (4 ′) is observed. This is because the first significant information can be easily read. In order to avoid such a situation, an area (4a) as a background is required in the visible image (4 ′) as shown in FIG.

  On the other hand, as in the example shown in FIG. 5C, when the visible image (4 ″) represents a photograph of a person and this photograph is the first significant information, the shading inside the visible image (4 ″) If it is lost, the silhouette can only be read as a square, and it cannot be inferred what the first significant information is. In the case of such a configuration, it is possible to form only a visible image (4 ″).

  As described above, it is necessary to form the visible image (4) with the first significant information and the background region when the silhouette of the visible image (4 ′) is observed. This is a case where it is possible to infer what the information is. Thus, in the present invention, it is necessary to change the configuration of the visible image (4 ′) depending on what is used for the first significant information.

  Hereinafter, examples of the latent image printed matter produced in detail will be described in accordance with the above-described mode for carrying out the invention, but the present invention is not limited to these examples.

  Example 1 will be described with reference to FIGS. 1 to 4 used in the embodiment. Example 1 is an example in which a visible image (4) and a latent image (5) are formed as binary images, and each is formed by an offset printing method.

  FIG. 1 shows a latent image printed material (1) according to the present invention. The latent image printed matter (1) includes a light grayish light blue printed image region (3) on a substrate (2). For the base material (2), general white fine paper (manufactured by Nippon Paper Industries Co., Ltd.) was used.

  The configuration of the print image area (3) of the present invention is shown in FIG. The print image area (3) includes a visible image (4) having first significant information and a latent image (5) having second significant information. In the first embodiment, the first significant information is the letter “A” of the alphabet, and the second significant information is the letter “B” of the alphabet.

  The visible image (4) shown in FIG. 2 is composed of a letter “A” of alphabet with a solid area ratio of 100% in a hexagon with an area ratio of 50% equal to the size of the print image area (3). First significant information is provided. The gradation expression area of the visible image (4) in Example 1 is 50%. The latent image (5) shown in FIG. 2 has an area ratio of 0 only in the letter “B” in a solid hexagon with an area ratio of 100% equal to the size of the print image area (3). Consists of% Nuqui. The gradation representation area of the latent image (5) is 100%.

  As shown in FIG. 3, the latent image (5) having the above configuration is formed on a white base material (2) and white ink of the same color as the base material (2) (best one GIGA white M-SOYA T & K TOKA And a wet offset printing method using a grayish light blue metallic ink shown in Table 1 so as to overlap therewith. The ink in Table 1 is a blue glittering ink prepared by mixing a blue metallic ink with a silver metallic ink. In addition, the 75 degree | times specular glossiness of the base material (2) in Example 1 was 10.1, and the 75 degree | times specular glossiness of the latent image (5) was 15.8.

  The effect of the latent image printed material (1) produced with the above structure is demonstrated using FIG. As shown in FIG. 4 (a), when the latent image print (1) is observed under diffuse reflected light, the letter “A” of the alphabet as the first significant information can be visually recognized by the shade of grayish blue. It was. On the other hand, as shown in FIG. 4B, when the latent image printed material (1) is observed under specular reflection light, the visible image (4) strongly reflects light, thereby compressing the light and darkness. As the information disappeared visually, the letter “B” of the alphabet, which is the second significant information of the latent image (5), appeared due to the intensity of light.

  As described above, it was confirmed that by changing the observation angle and observing, the first significant information and the second significant information can be completely changed and observed without being mixed.

  The second embodiment will be described with reference to FIGS. In the second embodiment, the first significant information included in the visible image (4-1) and the second significant information included in the latent image (5-1) are each set as a multi-tone image, and each image is offset printing. It is an example formed by.

  FIG. 6 shows a latent image print (1-1) according to the present invention. The latent image print (1-1) is formed by forming a silver print image region (3-1) on a substrate (2-1). A common white fine paper (made by Nippon Paper Industries Co., Ltd.) was used for the substrate (2-1) as in Example 1.

  The configuration of the print image area (3-1) of the present invention is shown in FIG. The print image area (3-1) includes a visible image (4-1) having first significant information and a latent image (5-1) having second significant information. In Example 2, the first significant information is a male face photograph, and the second significant information is a wrinkle image.

  In the visible image (4-1) shown in FIG. 7, a male face photograph having the same size as the print image area (3-1) is gradation-compressed by image processing software, and the gradation expression area is 60% (maximum). The area ratio was changed to 100% and the minimum area ratio was 40%. In the latent image (5-1) shown in FIG. 7, a multi-tone image of a wrinkle is arranged in an area equal to the size of the print image area (3-1), and the gradation is inverted. That is, an image of a cocoon having a complex gradation including a portion with an area ratio of 0% is formed in a solid square with an area ratio of 100%. The gradation expression area of the latent image (5-1) is 100%.

  As shown in FIG. 3, the latent image (5-1) having the above configuration is formed on a white base (2-1) using white ink (best one manufactured by GIGA white M-SOYA T & K TOKA). After printing with the wet offset printing method, the visible image (4-1) is printed with the silver ink (manufactured by New Champion Silver DIC) in the same manner as the wet offset printing method so as to be superimposed on the latent image printed matter (1 -1) was obtained. The 75 ° specular gloss of the substrate (2-1) in Example 2 was 10.1, and the maximum 75 ° specular gloss of the latent image (5-1) was 25.5. .

  The effect of the latent image printed matter (1-1) produced with the above structure is demonstrated using FIG. As shown in FIG. 8 (a), when the latent image printed matter (1-1) was observed under diffuse reflected light, a male face photograph, which was the first significant information, could be visually recognized by silver shades. On the other hand, as shown in FIG. 8B, when the latent image printed matter (1-1) is observed under specular reflection light, the visible image (4-1) strongly reflects light, thereby compressing the shade. The first significant information disappeared visually, and a wrinkle image, which is the second significant information represented by the latent image (5-1), appeared from the relative gloss difference due to the intensity of light.

  As described above, it was confirmed that by changing the observation angle and observing, the first significant information and the second significant information can be completely changed and observed without being mixed.

DESCRIPTION OF SYMBOLS 1, 1-1 Latent image printed matter 2, 2 ', 2 ", 2-1 Base material 3, 3-1 Print image area | region 4, 4', 4", 4-1 Visible image 4a Area | region 5 used as a background 5-1 Latent image 6, 6-1 Visible light source 7a, 7a-1, 7b, 7b-1 Observer's viewpoint 8 Visible image of prior art 9 Latent image 10A of prior art 10B Regular reflection in prior art Image visible under light

Claims (2)

A printed image area is provided on at least a part of the substrate,
The printed image area is formed of a material including a glittering material on a transparent image formed of a material having a glossiness higher than that of the base material or a latent image having the second significant information of the same color as the base material. A visible image having first significant information of a color different from that of the substrate is laminated,
The latent image is the same size or smaller than the visible image and has a higher gloss than the base material,
The visible image is formed such that a difference between the maximum area ratio and the minimum area ratio in the visible image is 10% to 75%,
When observed under diffuse reflected light, the first significant information is visible, and when observed under specular reflected light, the first significant information and the vicinity of the first significant information The first significant information disappears due to a decrease in contrast, and due to the difference in glossiness between the base material and the latent image, the amount of specular reflection in the area where the latent image is present does not exist in the latent image. The latent image printed matter , wherein the second significant information can be visually recognized by becoming stronger than the regular reflection light amount of the region .   The latent image printed matter according to claim 1, wherein a difference in glossiness between the base material and the latent image is 5 or more in 75 ° specular gloss (JIS P8142).

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