JP5358819B2 - Latent image printed matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a latent image printed matter in which an observable image changes into a different image according to change in an observation angle in the field of security printing for printed matter such as bank notes, passports, securities, identification cards, credit cards, and traffic tickets requiring anticounterfeit effect. <P>SOLUTION: The latent image printed matter has a first image formed of a brilliant material and a second image formed of a transparent material on a substrate. The first image includes a background part and an information part. The background part is formed of a background element group having a plurality of background elements arranged therein. The information part is formed of an information element group having a plurality of information elements arranged therein. The background elements and the information elements are adjacent or close to each other. The second image is formed of a second element group having a plurality of second elements arranged therein. The second elements are not superimposed on the information elements and are formed at least partially overlapped with the background elements. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  In the field of security printed matter such as banknotes, passports, securities, identification cards, cards and passports that require anti-counterfeit effects, the present invention can observe images according to changes in observation angles. The present invention relates to a latent image print that changes to a different image.

  Recent advances in digital equipment such as scanners, printers, and color copiers have made it possible to easily produce elaborate copies of valuable prints. As one of the anti-counterfeiting techniques for preventing duplication and forgery, there have been many ones to which an optical security element represented by a hologram whose image changes depending on the observation angle is attached.

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

  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. An invention relating to an information carrier for preventing counterfeiting that changes to completely different information by changing the angle has already been filed (see, for example, Patent Document 1 and Patent Document 2).

Japanese Patent No. 3398758 JP 2008-188973 A

  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 proper conditions for obtaining optimal switchability from the first print image to the second print image. Furthermore, even in a printed matter formed with such a great amount of effort, there is a problem 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 switch effect when printed on coated paper, there is a problem that the switch effect becomes unclear when printed on fine paper.

  Specifically, for example, as shown in FIG. 1, the letter “A” of the alphabet, which is a visible image (1), is formed with ink containing a glittering material (for example, gold ink), and transparent and low When the letter “B” of the alphabet, which is the latent image (2), is formed with glossy ink, the smoothness is low in observation under diffuse reflected light even when coated paper is used as a base material. Even when high-quality paper is used as a base material, the letter “A” of the alphabet is similarly visually recognized.

  However, in the observation under specular reflection light, when coated paper is used as a base material, only the alphabet “B”, which is a latent image, is visually recognized (3-a). In such a case, the letter “A” of the alphabet as the visible image (1) overlaps the character “B” of the alphabet as the latent image and appears (3-b). As described above, there is a problem that the switch effect is greatly influenced by the base material, and the switch effect becomes unclear depending on the base material used.

  In addition, when forming the technique described in Patent Document 2 using high-quality paper as a base material, the visible image (1) is formed using a metallic ink of a relatively low color density such as gold or silver as it is. In general, use a mixture of metallic pigments and colored pigments such as red, blue, and black in the same resin, or use a mixture of metallic inks and colored inks. After forming the background color, it has been difficult to greatly change the color of the visible image (1) by a method such as reprinting with silver ink. This is because, when a visible image (1) is designed by mixing colored pigments, the color density of the visible image (1) is increased by the amount of the mixed colored pigment, so that the visible image (1) under specular reflection light. This is because the visible image (1) appearing in the latent image (2) becomes stronger and the switching effect is greatly reduced when the image and the latent image (2) appear mixed. Therefore, when forming the technique of Patent Document 2 using high-quality paper as a base material, there is a problem that variations in the color of the visible image (1) are scarce and the degree of freedom in design is low.

  The present invention aims to solve the above-described problems, and has an effect of switching an image under diffuse reflection light and regular reflection light, which is formed using an ink containing a glittering material and a transparent ink. It is a printed material, and it is very easy to design and manufacture the image line structure, and it is easy to design and is inexpensive. Even if it is formed from general high-quality paper as a base material, the switch effect does not decrease. The present invention relates to a highly effective latent image printed matter.

  The latent image printed matter of the present invention has a printing region on at least a part of the substrate, and the printing region includes a glittering material and is formed on a first image formed of a material having a color different from that of the substrate. A second image formed of a transparent material is formed, and the first image includes a background portion and an information portion, and the background portion has a background element regularly arranged in a specific direction at a constant pitch. The information part is formed by an information element group in which a plurality of information elements are regularly arranged in a specific direction, and the background element and the information element are formed by a plurality of background element groups. The second image consists of two or more second elements arranged regularly in the same direction as a specific direction at the same pitch as the background elements forming the background element group. Formed by a second group of elements, the second element being an information element In the observation angle region that is not superimposed on the background element and is at least partially overlapped with the background element, and the diffuse reflection light is dominant, the first image can be observed, and the regular reflection light is the dominant observation angle. In the region, the second image can be observed.

  The latent image printed matter of the present invention is characterized in that the background element, the information element, and the second element are image lines and / or pixels.

  The latent image printed matter of the present invention is characterized in that the width and height of the second element are equal to or less than the width and height of the background element.

  The latent image printed material of the present invention is formed such that the area ratio of the background portion is 30% or more and 85% or less, and the area ratio of the information portion does not exceed the area ratio of the background portion and is 15% or more and 50% or less. It is formed.

  The latent image printed matter of the present invention is formed such that the pitch of the information elements in the information element group, the pitch of the background elements in the background element group, and the pitch of the second elements in the second element group are 0.03 mm or more and 1 mm or less. It is characterized by that.

  The latent image printed matter of the present invention is characterized in that a transparent material is mixed with a functional material.

  In the latent image printed material of the present invention, the transparent ink used for forming the latent image (second image) does not have an object color, and therefore has an area ratio above the visible image (first image). Even if they are simply overlapped with each other, they are completely invisible under diffuse reflection. Therefore, unlike the technique described in Patent Document 1, it is not necessary to take a great deal of effort in designing the printed matter such as color design and adjustment of the dot area ratio.

  In the technique described in Patent Document 1, since the latent image is formed using colored ink, it is necessary to form the latent image with a low dot area ratio in consideration of the concealment property of the latent image under diffuse reflected light. However, in the present technology, the latent image can be formed with a high halftone dot area ratio because transparent ink is used, and as a result, the visibility of the latent image that appears in observation under specular reflection light is extremely high. Can keep.

  Unlike the technique described in Patent Document 2, the latent image printed material of the present invention appears as a mixture of the first image and the second image in observation under specular reflection light even when printing is performed using high-quality paper as a base material. There is nothing. As a matter of course, the first image and the second image do not appear mixedly in observation under specular reflection light even when a highly smooth coat such as coated paper or art paper is used as a base material. Therefore, the switch effect is not greatly influenced by the base material.

  In addition, since the latent image printed matter of the present invention has improved the switching effect, even when using high-quality paper, a pigment having a strong coloring power, for example, any color such as black, red, or blue is incorporated into the ink together with the glittering material. By mixing, it is possible to form a first image having a high color and high density. As a result, a visible image having a rich color can be formed, and the degree of freedom in design has dramatically increased.

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

(A) shows a visible image in the case of forming the conventional technique, (b) shows a latent image in the case of forming the conventional technique, and (c) forms the conventional technique using coated paper as a base material. In this case, an image that appears under specular reflection light is shown, and (d) shows an image that appears under specular reflection light when a conventional technique is formed using high-quality paper as a base material. The latent image printed matter in this invention is shown. (A) shows the 1st image in this invention, (b) shows the background part formed of the background element group, (c) shows the information part formed of the information element group. The 2nd image in this invention is shown. The positional relationship of the superimposition of the first image and the second image in the present invention is shown. (A) shows the case where the background element group and the information element group are formed with pixels when the present invention is formed with pixels, and (b) shows the case where the second element group is formed with pixels. The positional relationship of the superimposition of the first image and the second image when the present invention is formed of pixels is shown. The structural example of the background element group in the case of forming a 1st image and an information element group is shown. (A) shows an image that appears in the latent image print when the observer's viewpoint is in the observation angle region where diffuse reflection light is dominant, and (b) shows that the observer's viewpoint is specularly reflected light. When in the dominant viewing angle region, it shows an image that appears in the latent image print. 2 shows a latent image printed matter in Example 1 of the present invention. (A) shows the 1st image in Example 1 of this invention, (b) shows the background part formed by the background element group, (c) shows the information part formed by the information element group. Show. The 2nd image in Example 1 of this invention is shown. The positional relationship of the superimposition of the 1st image and 2nd image in Example 1 of this invention is shown. (A) shows an image that appears in the latent image print when the observer's viewpoint is in the observation angle region where diffuse reflection light is dominant, and (b) shows that the observer's viewpoint is specularly reflected light. When in the dominant viewing angle region, it shows an image that appears in the latent image print. 10 shows a latent image printed matter in Example 2 of the present invention. (A) shows the 1st image in Example 2 of this invention, (b) shows the background part formed by the background element group, (c) shows the information part formed by the information element group. Show. The 2nd image in Example 2 of this invention is shown. The positional relationship of the superimposition of the 1st image and 2nd image in Example 2 of this invention is shown. (A) shows an image that appears in the latent image print when the observer's viewpoint is in the observation angle region where diffuse reflection light is dominant, and (b) shows that the observer's viewpoint is specularly reflected light. When in the dominant viewing angle region, it shows an image that appears in the latent image print. 10 shows a latent image printed matter in Example 3 of the present invention. (A) shows the 1st image in Example 3 of this invention, (b) shows the background part formed by the background element group, (c) shows the information part formed by the information element group. Show. The 2nd image in Example 3 of this invention is shown. (A) shows an image that appears in the latent image print when the observer's viewpoint is in the observation angle region where diffuse reflection light is dominant, and (b) shows that the observer's viewpoint is specularly reflected light. When in the dominant viewing angle region, it shows an image that appears in the latent image print.

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

  First, the present invention will be described with reference to the drawings. FIG. 2 shows a latent image print (4) according to the present invention. The latent image print (4) has a print area (6) at least partially on the substrate (5), and the second print area (6) includes a second image on the first image (7). The image (8) is formed to overlap.

  FIG. 3 shows the configuration of the first image (7). The first image (7) shown in FIG. 3 (a) includes a background portion formed by a background element group (11) in which a plurality of background elements (9) shown in FIG. 3 (b) are arranged, and FIG. It comprises an information part formed by an information element group (12) in which a plurality of information elements (10) shown in (c) are arranged. The background portion is composed of a print region having a constant density gradation, and in the form for carrying out the present invention, is composed of a “circle” shown in FIG. In the embodiment for carrying out the present invention, the information section is composed of alphabet “A” shown in FIG.

  The background element (9) and the information element (10) in the present invention are pixels and / or image lines. The term “pixel” used here is an element that forms a printed image, and is a halftone dot shape that expresses changes in shading in terms of area ratio (size of dots), such as a circular shape, polygonal shape, figure shape, and character shape. That is. The “image line” means a broken line, a broken line, a straight line, a curve, or a wavy line, and any image line shape is included in the technical idea of the present invention.

  In the present invention, the background element (9) is composed of pixels and / or lines, and the information element (10) is composed of pixels and / or lines. However, in the case of the information element (10), it is possible to form a solid image by arranging the square-shaped fine pixels which are one of the information elements (10) adjacent to each other with high density without any gaps. A gradation image may be formed according to the size or density of fine pixels. Thus, the information element (10) may be in any form as long as it occupies a part of the area ratio in the print region (6) so as not to overlap with the background element (9). As for the combination of the background element (9) and the information element (10), the latent image printed material of the present invention can be produced for all combinations of pixels and / or image lines. In the embodiment for carrying out the present invention, the background element (9) and the information element (10) will be described as a case where an image line is used.

  As shown in the partially enlarged view of FIG. 3A, the “enclosure” that is the print area forming the background portion has a constant background element (9) having a specific line width (W1). The alphabet “A”, which is formed by a plurality of background element groups (11) regularly arranged in a specific direction at a pitch (P1), forms an information portion, and has a specific line width (W2). ) Is formed by an information element group (12) that is regularly arranged in a specific direction so as to be adjacent to the background element (9). The “specific direction” in the present invention is the S1 direction in the drawing when the background element (9) and the information element (10) are lines, and is regularly arranged in a direction perpendicular to the line. ing.

  In an embodiment for carrying out the present invention, an information element group (12) constituting an information part is provided between a plurality of background elements (9) formed by forming a background element group (11) constituting a background part. A plurality of formed information elements (10) are arranged, and the plurality of background elements (9) and the plurality of information elements (10) are formed so as to be adjacent to each other, and are formed to overlap each other. There is nothing.

  When the background element (9) and the information element (10) are formed to overlap, for example, when the background element (9) and the information element (10) are each formed with a value smaller than 100%, Unnecessary shading occurs in the overlapped area, and the shading is reflected in the second image (8) appearing under specular reflection light. Further, for example, when the background element (9) and the information element (10) are each formed with a solid area ratio of 100%, the overlapping area cannot be a density of 100% or more. As a result, the area occupied by the information element (10) corresponding to the overlapped area is lost, the gradation difference between the background element (9) and the information element (10) is reduced, and the first image (7) is visually recognized. There arises a problem that the property becomes low.

  The background element (9) and the information element (10) do not have to be formed adjacent to each other, and may be formed close to each other. A form in the case where the background element (9) and the information element (10) are formed close to each other will be described later.

  The first image (7) is formed by ink containing a glittering material.

  FIG. 4 shows the configuration of the second image (8). In the second image (8), the second element (13) having a specific line width (W3) is regularly arranged at the same pitch (P1) as the background element (9) forming the background element group. Formed by a second group of elements arranged in a specific direction and representing the letter “B” of the alphabet. The “specific direction” in the present invention is the S1 direction in the drawing when the second element (13) is an image line, and is regularly arranged in a direction orthogonal to the image line.

  The second image (8) is formed over the first image (7) with a transparent material.

  In the partially enlarged view in the drawing, the background element (9) is illustrated by a vertically striped image line, the information element (10) is illustrated by a black solid, and the second element (13) is illustrated. Although it is illustrated in white, vertical stripes, black solids and white are illustrated in order to make it easy to distinguish the configuration of each element, and each actual element is represented by vertical stripes, black solids and It is not formed with white elements. In the subsequent drawings, the background element, the information element, and the second element are illustrated by vertical stripes, black solids, and white elements, respectively. In order to make the distinction easy, the vertical stripes, black solids, and outlines are illustrated, and the actual elements are not formed by vertical stripes, black solids, and outline elements.

  FIG. 5 shows an appropriate positional relationship of superposition of the first image (7) and the second image (8). The second element (13) forming the second image (8) must not be formed on top of the information element (10), and the second element (13) 9) Overlaid on top. When the second element (13) and the information element (10) are formed to overlap, the second image (8) is displayed in the second image (8) in the observation under specular reflection light, as in the technique described in Patent Document 2. There arises a problem that the information part (12) of one image (7) is mixed and visually recognized as an unclear image. Therefore, in order to establish this formation condition, the pitch of the second element (13) and the pitch of the background element (9) must be formed equal.

  As described above, the background element (9) and the information element (10) are formed adjacent to each other, and the second element (13) is configured so as not to overlap the information element (10). It is necessary to design the line width (W3) of the element (13) while keeping it within the line width (W1) of the background element (9). As the image area ratio of the second element (13) (the area of the image line closed in a certain area) is larger, the visibility of the second image (8) that appears under specular reflection light becomes higher. It is desirable to design with the same line width (W1) as that of the background element (9). However, if the values are completely the same, printing is performed because there is no tolerance for misalignment at the time of manufacture. It is necessary to design the line width (W3) of the second element (13) in consideration of the printing accuracy in the machine.

  As described above, in the present embodiment, the image line width (W3) of the second element is set to a value slightly smaller than the maximum image line width in the executable image line width (W1). Further, the second element (13) may not overlap even the information element (10), and may overlap on the base material on which the background element (9) is not formed. When the base material is fine paper, the second element (13) formed on the base material is not reflected in the second image (8) appearing under specular reflection light.

  In the latent image printed matter of the present invention, as described above, the second element (13) does not overlap the information element (10) under the condition for improving the visibility of the second image (8). However, even if the second element (13) slightly overlaps the information element (10) due to misalignment at the time of printing, since the area overlapping the background element (9) is large, the second image (8 ) Is hardly visually recognized and is not affected by the visibility of the second image (8), the second element (13) is the information element (10). The state of being slightly overlapped is also within the scope of the effect of the present invention.

  Up to now, the latent image printed matter of the present invention has been provided with the first by the background element group in which a plurality of lines are arranged and the information element group in which a plurality of lines are arranged in at least a part of the print area on the substrate. In the above description, the first image is formed by overlapping the second element group formed by arranging a plurality of image lines on the first image. However, as described above, in the present invention, pixels can be formed instead of image lines, and a background element group consisting of a plurality of pixels and a plurality of pixels are arranged in at least a part of the print area on the substrate. A first image is formed by the information element group, and the first image is formed by overlapping a second element group in which a plurality of pixels are arranged on the first image. But it ’s okay.

  However, as shown in FIG. 6A, when the background element group and the information element group in the first image (7) are formed by pixels, the background portion has a background element (9) having a specific pixel width (R1). ) Is formed by a background element group (11) regularly arranged in a specific direction at a constant pitch (P1), and the information part is an information element (10 with a specific pixel width (R2)). ) Are formed by an information element group (12) regularly arranged in a specific direction adjacent to or close to the background element (9). The pixel height (H1) may be the same as or different from the pixel width (R1), and the pixel height (H2) may be the same as or different from the pixel width (R2). The “specific direction” in the present invention means the vertical and horizontal directions in the S1 direction and the S2 direction in the drawing when the background element (9) and the information element (10) are pixels, and a matrix as shown in the figure. It is arranged regularly in a shape.

  Further, as shown in FIG. 6B, when the second element group in the second image (8) is formed by pixels, the second image (8) has a specific pixel width (R3). The second element group is formed by a second element group that is regularly arranged in a specific direction at a constant pitch (P1). The pixel height (H3) may be the same as or different from the pixel width (R3). The “specific direction” in the present invention is the vertical and horizontal directions in the S1 direction and S2 direction in the drawing when the second element (13) is a pixel, and is regularly arranged in a matrix as shown in the figure. Arranged.

  FIG. 7 shows a detailed view of the overlapping position of the first image (7) shown in FIG. 6 (a) and the second image (8) shown in FIG. 6 (b). The second element (13) constituting the second image (8) is formed only on the background element (9) constituting the background part (11) of the first image (7). Become.

  The positional relationship in which the second element group is superimposed on the background element group and the information element group is the same as in the case of the image line, and the second element (13) forming the second image (8). ) Must not be formed over the information element (10), and the second element (13) is formed over the background element (9). Therefore, the pixel width (R3) of the second element (13) is designed to be within the pixel width (R1) of the background element (9), and the pixel height (H3 of the second element (13) is designed. ) Must be designed with a width within the pixel height (H1) of the background element (9).

  As described above, regarding the background element, the information element, and the second element, the background element and the information element are formed adjacent to or in close proximity to each other, whether in the case of an image line or a pixel. And the second element are formed so as not to overlap each other, and the second element is formed so as to overlap at least partly with the background element.

  FIG. 8 shows an example of a combination of a background element (9) forming a background part constituting the first image and an information element (10) forming an information part in the latent image printed matter of the present invention. The background element (9) and the information element (10) can be formed by lines and / or pixels. As shown in FIGS. 8 (a) and 8 (b), a combination of lines and lines, FIG. ) And (d), and a combination of a pixel and a pixel, and a combination of an image line and a pixel as shown in FIGS. 8 (e) and 8 (f) may be used.

  Further, even if the background element (9) and the information element (10) are formed adjacent to each other as shown in FIGS. 8 (a), (c) and (e), FIG. 8 (b), (d) and ( They may be formed close to each other as shown in f).

  FIG. 9 shows a visible state of the latent image print (4) formed with the above configuration. As shown in FIG. 9 (a), the positional relationship among the light source (14), the printed matter (4), and the observer (15a) is determined under diffuse reflected light (the angle of light incident on the printed matter, the observer and the printed matter). When the observation is performed at an angle at which the connecting angles are greatly different), the observer sees the first image (7) shown in FIG.

  Further, as shown in FIG. 9B, the latent image printed matter (4) is obtained by changing the positional relationship among the light source (14), the printed matter (4), and the observer (15b) under regular reflection light (light incident on the printed matter). And the second image (8) shown in FIG. 9 (b), the observer can observe the first print that has become lighter. An image in which the background portion (11) of the image is superimposed is visually recognized.

  As described above, the first image (7) is mainly viewed in the observation under diffuse reflection light, and the second image (8) is mainly visible in the observation under specular reflection light. To demonstrate. Further, in the present invention, even when formed on high-quality paper, the first image (7) (specifically, in the second image (8) in the observation under specular reflection light, which is a problem in the conventional technology, Does not cause the phenomenon that the information portion (12) of the first image is mixed and visually recognized.

  Here, the principle of image switching in the present invention will be described, and in addition, even when the latent image printed material (4) of the present invention is formed using the base material (5) as high-quality paper, the first image and the second image The reason why an image mixing phenomenon does not occur will be described below.

  A first image formed of a transparent material on a first image having a color different from that of the substrate and including a glittering material and having a background portion and an information portion in a range of an appropriate area ratio. When the printed image is formed by superimposing the two images, the second image formed of the transparent material is invisible under diffuse reflected light. Only the first image formed including the material is visible. In this case, the gradation difference existing between the information part and the background part constituting the first image can be recognized.

  On the other hand, in the observation under specular reflection light, the first image formed including the glittering material has a brightness that increases at a stretch by strongly reflecting the incident light, and the color that has been visually recognized under diffuse reflection light. It changes to an extremely pale color. At this time, when the maximum value and the minimum value of the area ratio of the first image formed including the glittering material are within an appropriate range (specifically, the area ratio difference is within 50%). The observer recognizes that the entire first image is converged in a certain light gradation as if the gradation difference between the information part and the background part of the first image has disappeared. Is done. This is because the glittering material reflects light and the amount of reflected light reaching the eyes of the observer becomes extremely large, so that it is difficult to recognize the size of the area ratio and the density difference existing in the first image. It is to become.

  The first image includes a region where a transparent material forming the second image is overlaid and a region where the transparent material is not overlaid. In the region where the transparent material is overlaid, the light reaching the first image existing under the transparent material is greatly reduced compared to the region where the transparent material is not overlaid, so that an increase in the brightness of the first image is suppressed. . On the other hand, in the region where the transparent material is not overlaid, the incident light reaches the first image without being blocked by the first image, and the brightness of the first image increases.

  As described above, the presence or absence of the transparent material, that is, whether or not the first image changes lightly depending on the second image is determined. As a result, the region where the second image is formed is observed darkly, the region where the second image is not formed is observed brightly, and the gradation difference existing in the first image is lost, so that the first image is lost. Disappears and the second image is visualized. The above is the basic principle in the present invention in which the first image is visually recognized under diffuse reflected light and the second image is visually recognized under regular reflected light.

  Next, in order to show that the effect of the present invention is superior to the effect of the conventional technique, the conventional technique (the technique described in Patent Document 2) is formed using fine paper as a base material below. Next, the problem that the information part of the second image and the first image appears mixedly in observation under specular reflection light will be described.

  As is apparent from the principle of the manifestation of the switch effect described above, the second image is visualized under specular reflection light because the first image reflects light or changes lightly or reflects light. Involved in not being able to change. The first image has an information portion and a background portion, and an effect of converging the gradation difference between the information portion and the background portion works in a region where light is reflected, that is, a region where the second image is not overlapped. However, in a region where light is not reflected, that is, a region where the second image is formed in an overlapping manner, the tone difference is not lost, and the tone difference is recognized as it is by the observer.

  Therefore, as shown in FIG. 1, the second image (2) in which the letter “B” is formed with a solid area ratio of 100% is superimposed on the first image (1). In this case, in the observation under the specular reflection light, as shown in FIG. 1D, the information part of the first image is reflected inside the second image that should be visually recognized independently. Result. In other words, the problem that these images are mixed together is not the irregular state, but the original form of the prior art.

  However, even when the conventional technique is used, when the paper having a relatively high gloss, such as coated paper or art paper, is formed as a base material, the first image and the second image are mixed. The phenomenon does not occur. This is because the substrate itself strongly reflects incident light as in the first image (1). The background portion of the first image (1) is composed of halftone dots and image lines made of a glittering material, but is not composed completely of solid, so that there are no halftone dots or image lines. The substrate is exposed in the point or non-image area.

  When a base material such as coated paper or art paper is used, the exposed base material itself has an effect of strongly reflecting light at the time of regular reflection as well as halftone dots and image lines formed of a glittering material. . Therefore, as compared with the high-quality paper having a low effect of reflecting light by the base material itself, the region where the second image was not superimposed on the first image and the second image were superimposed. In the area, the contrast of light and darkness that occurs depends on the presence or absence of the second image. Compared with this strong contrast, the contrast of light and shade in the image caused by the mixing of the information part of the first image in the second image is relatively extremely small. Therefore, when coated paper or art paper is used as a base material, the phenomenon in which the first image and the second image observed under specular reflection light appear mixed is not recognized by the observer.

  On the other hand, when the conventional technology is formed using fine paper as a base material, the base material has an extremely low effect of reflecting light and hardly contributes to an increase in the contrast of the second image. The contrast of the light and shade in the image generated when the information part of the first image is mixed in the image is recognized as it is by the observer.

  In the present invention, as described in the embodiment, the second image (8) that constitutes the second image (8) only on the background element group that constitutes the background portion (11) of the first image (7). It has a structure in which elements are stacked. Since the background element group is formed of a plurality of image lines having a constant area ratio or a plurality of pixels, the gradation is constant and no shading occurs. Therefore, in the observation under specular reflection light, the phenomenon in which the density of the first image (7) is reflected in the second image (8) formed over the background element group as in the prior art is as follows. Does not occur.

  In addition, the information part (12) of the first image (7) is incident on the information part (12) because the second element group that inhibits the incidence of light is not overlapped on the information part (12) of the first image (7). Since it changes to a pale color upon receiving light, it is difficult to see. Therefore, in the observation under specular reflection light, the first image (7) disappears and only the second image (8) is recognized.

  As described above, when the latent image printed matter (4) of the present invention is observed under diffuse reflected light, only the first image (7) is visually recognized, and when observed under specular reflected light, Only the second image (8) is visible. In this way, different images that are not correlated at all due to differences in the angle of observation and changes in the angle of incident light are visually recognized, and the switching effect is clear because the images do not mix with each other. Excellent authenticity.

  As the ink for forming the first image (7), it is necessary to use an ink containing a glittering material. In order to cause the first image (7) to converge to a certain gradation under specular reflection light and to cause the second image to appear, the image lines constituting the first image (7) This is because it is necessary to have a characteristic that the brightness is increased and lightly changed by incident light.

  As long as the latent image printed material (4) is formed using a high-gloss paper such as coated paper or art paper as a base material, the first image (7) is simply formed using gloss type ink. Since the effect of increasing the brightness can be obtained by the gloss of the resin of the ink itself, the glittering material is not essential. However, in non-coated paper such as high-quality paper, the resin component penetrates into the paper, so that a glittering material that does not penetrate into the paper and remains on the paper surface and reflects light is essential. Therefore, a glittering material is essential in the present invention aiming at obtaining a higher switching effect without selecting a substrate.

  The first image (7) may be given a color such as red, blue or black. As a method, a color pigment may be mixed together with a glittering material in the ink forming the first image (7), or the inks may be mixed together. The same image may be formed, and then the same first image (7) may be overlaid with ink containing a glittering material. The color of the color pigment may be any hue such as black, red, blue or yellow.

  However, when an excessive amount of pigment is mixed, even if the first image is formed in an appropriate area ratio range, the gradation difference (darkness difference) in the first image becomes large, and the ink in the ink When the mixing ratio of the glittering material is decreased, or the first image is not completely lost in observation under specular reflection light. Therefore, when pigments are mixed or when inks are mixed, a range not exceeding one half of the blending ratio of the glittering material in the ink, even when mixing colored pigments of any color It is desirable to keep it on.

  On the other hand, when colors are given by forming the same image as the first image in advance with colored ink on the base, a sufficient switch effect can be obtained regardless of the color and density of the ink used. it can.

  The above-described glittering material may be a general metal powder pigment such as aluminum powder, copper powder, zinc powder, tin powder, brass powder or iron phosphide.

  In addition, when a general pearl pigment such as an iris pearl pigment and scale pigment, or a functional pigment such as a glass flake pigment or a cholesteric liquid crystal pigment is used, a light / dark flip-flop that changes only the lightness of the first image. Color flip-flop property (characteristic that changes not only lightness but also color tone) that changes not only the property (mainly the property that changes only the lightness) but also the color tone of the first image can be imparted. In addition, functional materials such as pigments such as fluorescent pigments, phosphorescent pigments or phosphorescent pigments, IR absorbing pigments, photochromic pigments, temperature indicating materials, and thermochromic materials may be added to the glittering material. It goes without saying that it is done.

  The ink that forms the second image (8) needs to be transparent. The ink may be glossy or matte as long as it is transparent, but it is desirable to use a matte transparent ink in order to achieve a high switching effect regardless of the substrate. This is because the ratio of blocking the amount of light reaching the first image (7) is higher when the mat-type ink is used, and the visibility of the second image (8) becomes higher. In addition, light-emitting pigments such as fluorescent pigments, phosphorescent pigments and phosphorescent pigments, IR absorbing pigments, photochromic pigments, temperature indicating materials, thermochromic materials, and other functional materials may be added to the transparent ink. In addition to the effects, various functionalities can be added.

  The area ratio of the background part (11) is formed in the range of 30% to 85%, and the area ratio of the information part (12) does not exceed the area ratio of the background part (11) and is 15% to 50%. % Or less.

  This is because when the area ratio of the background portion (11) is smaller than 30%, the effect of increasing the lightness of the image line becomes low, and the disappearance effect of the first image (7) may not be sufficient. When the area ratio of the part (11) exceeds 85%, the area ratio of the information part (12) is inevitably 15% or less, and there is a sufficient floor between the information part (12) and the background part (11). This is because no tone is produced and it is difficult for an observer to visually recognize the information indicated by the first image (7) under diffuse reflected light.

  The problem when the area ratio of the information part (12) is 15% or less is as described above, and when it exceeds 50%, the floor generated between the information part (12) and the background part (11). This is because the tone difference becomes so large that the first image (7) cannot be completely lost in observation under specular reflection light.

  Further, regardless of the values of the information part (12) and the background part (11), the area ratio difference between the information part (12) and the background part (11) needs to be kept within 50%. When the difference in area ratio exceeds 50%, the gradation difference generated between the information portion (12) and the background portion (11) becomes too large, and the first image (7 in observation under specular reflection light). This is because a problem that does not disappear) occurs.

  The pitch of the information elements in the information element group, the pitch of the background elements in the background element group, and the pitch of the second elements in the second element group are set in a range larger than 0.03 mm and not exceeding 1 mm. This is because a pitch smaller than 0.03 mm makes it difficult to include image lines and pixels whose quality can be controlled, and only a low-resolution image can be formed at a pitch exceeding 1 mm. In the case of forming with an image line, it is desirable to form the image line with a width of 0.03 mm to 1 mm. The reason is the same as the pitch.

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

  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.

  A first embodiment of the present invention will be described with reference to FIGS. In the second embodiment, an example will be described in which the background element, the information element, and the second element are each formed by a drawing line. White fine paper (manufactured by Nippon Paper Industries Co., Ltd.) was used as the base material (2-1).

  FIG. 10 shows a latent image print (4-1) in the present invention. The latent image printed matter (4-1) has a printing region (6-1) on the substrate (5-1), and the printing region (6-1) has a color different from that of the substrate. The first image (7-1) is formed of a material containing a glittering material, and the second image (8-1) is formed on the first image (7-1) with transparent ink. It is formed by overlapping.

  FIG. 11 shows a specific configuration of the first image (7-1). The first image (7-1) is an image in which an ellipse surrounds the Japanese character “Japan”, and the background portion (11-1) forming the ellipse and the information portion (12−) forming the character “Japan”. And 1).

  The background part (11-1) is formed by a background element group in which a plurality of background elements (9-1) having an image line width of 0.2 mm are arranged in the S1 direction at a pitch of 0.4 mm, and one information part (12- 1) is formed by an information element group in which a plurality of information elements (10-1) having a line width of 0.2 mm are arranged in the S1 direction at a pitch of 0.4 mm. The information element group and the background element group are formed so that the phases are shifted up and down by half a pitch, so that there is a contact portion, but there is no overlapping region.

  The 1st image (7-1) was formed on the fine paper which is a base material (5-1) by offset printing using silver ink (DIC New Champion Silver) which is a general metallic ink.

  FIG. 12 shows the second image (8-1). The second image is an image showing a cherry blossom petal dancing. The second image (8-1) is a second element (13-1) having a line width of 0.2 mm and a pitch of 0.4 mm. And a plurality of second element groups arranged in the S1 direction. The line width and pitch of the elements and the arrangement direction of the line are the same as the background element group forming the first image (7-1). The second image (8-1) was formed by being superimposed on the first image (7-1) in the positional relationship shown in FIG.

  In forming the second image (8-1), it was formed using OP varnish (BEST ONE matt medium manufactured by T & K TOKA) which is a general transparent ink.

  FIG. 13 shows a detailed view of the overlapping position of the first image (7-1) and the second image (8-1). The second element (13-1) constituting the second image (8-1) is a background element (9-1) constituting the background part (11-1) of the first image (7-1). Overlaid only on top.

  FIG. 14 shows the effect of the latent image print (4-1) of the present invention. FIG. 14A shows an image that is observed when the observer observes the latent image printed material (4-1) under diffuse reflected light. In the print region (6-1), the first image is displayed. Only the image (7-1) is visually recognized. At this time, the color of the first image (7-1) is recognized as dark gray which is a silver object color. FIG. 14B is an image observed when the observer observes the latent image printed material (4-1) under specular reflection light. The second image (8-1) and its periphery are shown. The background part (11-1) of the surrounding first image (7-1) is visually recognized. At this time, the second image (8-1) is visually recognized in dark gray which is a silver object color, and the background portion (11-1) of the first image (7-1) is visually recognized in light gray. The

  As described above, in the latent image print (4-1) of the present invention, the first image (7-1) and the second image (8-1) are clearly changed by changing the observation angle. In addition, the second image (8-1) and the first image (7-1) appear to be mixed in the observation under specular reflection light even when the high-quality paper is used as the base material (5-1). I was able to confirm that there was no.

  A second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, an example in which the background element, the information element, and the second element are each formed of pixels will be described. As the base material (5-2), a general white-colored fine paper (manufactured by Nippon Paper Industries Co., Ltd.) was used as in Example 1.

  FIG. 15 shows a latent image print (4-2) in the present invention. The latent image print (4-2) has a print area (6-2) on the base (5-2), and the print area (6-2) has a color different from that of the base. The first image (7-2) is formed of a material containing a glittering material, and the second image (8-2) is formed on the first image (7-2) with a transparent ink. Is formed by overlapping.

  FIG. 16 shows a specific configuration of the first image (7-2). The first image (7-2) is an image in which an ellipse encloses the character “Japan” in the Chinese character as in the first embodiment, and forms the character “Japan” with the background portion (11-2) forming the ellipse. The information part (12-2) is combined.

  The background portion (11-2) is formed by a background element group in which a plurality of background elements (9-2), which are solid circles having a diameter of 0.3 mm, are arranged at a pitch of 0.4 mm in the S1 direction and the S2 direction, On the other hand, the information element (12-2) has an information element (10-2) in a shape in which a circle having a diameter of 0.3 mm sharing a center is extracted from a circle having a diameter of 0.4 mm, and a pitch of 0. It is formed by a plurality of information element groups arranged at 4 mm in the S1 direction and the S2 direction. In the information element group and the background element group, the phase of the center of each element is completely coincident with each other, so that there is a contact portion, but there is no overlapping region.

  The first image (7-2) is printed on the fine paper which is the base material (5-2) by offset printing using gold ink (T & K TOKA UV Gold MG (red mouth)) which is a general metallic ink. Formed.

  FIG. 17 shows the second image (8-2). The second image is an image showing how the cherry blossom petals dance as in the first embodiment, and the second image (8-2) is a second element (filled circle having a diameter of 0.3 mm) ( 13-2) is formed by a second element group having a pitch of 0.4 mm and a plurality of elements arranged in the S1 direction and the S2 direction. The diameter, pitch, and arrangement direction of the elements are equal to those of the background element group forming the first image (7-2). The second image (8-2) was formed by being superimposed on the first image (7-2) in the positional relationship shown in FIG.

  In forming the second image (8-2), OP varnish (BEST ONE mat medium manufactured by T & K TOKA), which is a general transparent ink, was used.

  FIG. 18 shows a detailed view of the overlapping position of the first image (7-2) and the second image (8-2). The second element (13-2) constituting the second image (8-2) is a background element (9-2) constituting the background part (11-2) of the first image (7-2). Overlaid only on top.

  FIG. 19 shows the effect of the latent image print (4-2) of the present invention. FIG. 19A shows an image observed when the observer observes the latent image printed material (4-2) under diffuse reflected light. The first print area (6-2) contains the first image. Only the image (7-2) is visually recognized. At this time, the color of the first image (7-2) is recognized as a dark orange color that is a golden object color. FIG. 19B is an image observed when the observer observes the latent image printed material (4-2) under specular reflection light. The second image (8-2) and its periphery are shown. The background part (11-2) of the surrounding first image (7-2) is visually recognized. At this time, the second image (8-2) is visually recognized as a dark orange color that is a golden object color, and the background portion (11-2) of the first image (7-2) is a light orange color. Visible.

  As described above, in the latent image printed material (4-2) of the present invention, the first image (7-2) and the second image (8-2) are clearly changed by changing the observation angle, In addition, the second image (8-2) and the first image (7-2) appear to be mixed in the observation under specular reflection light even when the fine paper is used as the base material (5-2). I was able to confirm that there was no.

  A third embodiment of the present invention will be described with reference to FIGS. In Example 3, each of the background element, the information element, and the second element is formed with a stroke, and the first image and the second image are not binary images, as in Example 1 and Example 2, An example in which the image is formed as a gradation image having complicated shading will be described. As the base material (5-3), a general white-quality fine paper (manufactured by Nippon Paper Industries Co., Ltd.) was used as in Example 1 and Example 2.

  FIG. 20 shows a latent image print (4-3) according to the present invention. The latent image printed material (4-3) has a printing region (6-3) on the base material (5-3), and the printing region (6-3) has a color different from that of the base material. The first image (7-3) is formed of a material including a glittering material, and the second image (8-3) is formed on the first image with a transparent ink. Become.

  FIG. 21 shows a specific configuration of the first image (7-3). The first image is an image in which a rectangle is surrounded by a rose image having a complicated gradation, and a background portion (11-3) forming the rectangle and an information portion (12-3) forming the rose image are included. Combining.

  The background portion (11-3) is formed by a background element group in which a plurality of background elements (9-3) having a line width of 0.2 mm are arranged in the S1 direction at a pitch of 0.4 mm, and one information portion (12- 3) is formed by an information element group in which a plurality of information elements (10-3) having a width of 0.2 mm are arranged in the S1 direction at a pitch of 0.4 mm. The information element (10-3) forms a solid image of a rose having gradation by arranging fine pixels, so-called printing halftone dots, in a high density by combining large and small. Since the information element group and the background element group are out of phase by a half pitch, there is a contact portion, but there is no overlapping region.

  The 1st image (7-3) was formed on the quality paper which is a base material (5-3) by offset printing using the coloring metallic ink shown in Table 1. FIG. The ink shown in Table 1 has a characteristic that the color is slightly low-saturated red under diffuse reflected light, and changes to a light red color under regular reflected light.

  FIG. 22 shows the second image (8-3). The second image (8-3) is an image representing a butterfly having a complex gradation, and a plurality of second elements (13-3) having a width of 0.2 mm are arranged in the S1 direction at a pitch of 0.4 mm. Formed by the second element group. The second element (13-3) forms a solid image of a butterfly having gradations by arranging fine pixels, so-called printing halftone dots, in a large and small combination and arranging them at high density. The width, pitch, and drawing direction of the elements are equal to those of the background element group forming the first image (7-3). In the second image (8-3), the second element (13-3) overlaps only on the background element (11-3) of the first image (7-3) as in the first embodiment. Due to the positional relationship, they were formed on the first image (7-3) so as to overlap (not shown).

  In forming the second image (8-3), OP varnish (BEST ONE mat medium manufactured by T & K TOKA), which is a general transparent ink, was used.

  FIG. 23 shows the effect of the latent image print (4-3) of the present invention. FIG. 23A shows an image that is observed when the observer observes the latent image printed material (4-3) under diffuse reflected light. In the print region (6-3), the first image is displayed. Only the image (7-3) is visually recognized. At this time, the color of the first image (7-3) is recognized as a red color which is the object color of the colored metallic ink shown in Table 1. FIG. 23B is an image observed when the observer observes the latent image printed material (4-3) under specular reflection light. The second image (8-3) and its periphery are shown. The background part (11-3) of the surrounding first image (7-3) is visually recognized. At this time, the second image (8-3) is visually recognized in red, which is a golden object color, and the background portion (11-3) of the first image (7-3) is visually recognized in light red. .

  As described above, in the latent image printed material (4-3) of the present invention, even when the high-quality paper is used as the base material (5-3), the first image (7-3) using a chromatic color other than gold or silver ) Can be formed, the first image (7-3) and the second image (8-3) are clearly changed by changing the observation angle, and in observation under specular reflection light, It was confirmed that the second image (8-3) and the first image (7-3) were not mixed and appeared.

DESCRIPTION OF SYMBOLS 1 1st image in conventional technology 2 2nd image in conventional technology 3-a Image 3b observed under specular reflection when conventional technology is formed on coated paper When images are formed on fine paper, images 4, 4-1, 4-2, 4-3 observed under regular reflection light Latent image printed matter 5, 5-1, 5-2, 5-3 Material 6, 6-1, 6-2, 6-3 Print area 7, 7-1, 7-2, 7-3 First image 8, 8-1, 8-2, 8-3 Second image 9, 9-1, 9-2, 9-3 Background element 10, 10-1, 10-2, 10-3 Information element 11, 11-1, 11-2, 11-3 Background part 12, 12-1 , 12-2, 12-3 Information section 13, 13-1, 13-2, 13-3 Second element 14 Light source 15a, 15b Observation point of observer

Claims (6)

Having a printing area on at least a part of the substrate;
The print area is formed by forming a second image formed of a transparent material on a first image formed of a material having a color different from that of the base material including a glittering material,
The first image includes a background portion and an information portion, and the background portion is formed by a background element group in which a plurality of background elements are regularly arranged in a specific direction at a constant pitch, The information section is formed by an information element group in which a plurality of information elements are regularly arranged in the specific direction, and the background element and the information element are formed adjacent to or in close proximity to each other.
The second image is a second element in which a plurality of second elements are regularly arranged in the same direction as the specific direction at the same pitch as the background elements forming the background element group. Formed by groups,
The second element is not superimposed on the information element, and is formed on the background element or on the background element at least partially overlapping,
The latent image printed matter, wherein the first image can be observed in an observation angle region where diffuse reflection light is dominant, and the second image can be observed in an observation angle region where specular reflection light is dominant. The latent image printed material according to claim 1, wherein the background element, the information element, and the second element are an image line and / or a pixel. The latent image printed matter according to claim 1 or 2, wherein the width and height of the second element are equal to or less than the width and height of the background element. The area ratio of the background part is 30% or more and 85% or less, and the area ratio of the information part does not exceed the area ratio of the background part and is 15% or more and 50% or less. The latent image printed matter according to claim 1, wherein the latent image printed matter is a printed matter. The pitch of the information element in the information element group, the pitch of the background element in the background element group, and the pitch of the second element in the second element group are 0.03 mm or more and 1 mm or less. The latent image stamp part according to any one of claims 1 to 4, characterized in that: The latent image printed matter according to claim 1, wherein the transparent material is a mixture of a functional material.

Images