JP5533731B2 - Latent image printed matter - Google Patents

Description

  The present invention relates to a latent image printed material, and is particularly suitable for security printed materials such as banknotes, passports, securities, identification cards, cards, and passports that require an anti-counterfeit effect, and the image changes the viewing angle. The present invention relates to a latent image printed material that changes in response.

  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, An anti-counterfeit printed matter that can be formed by a general printing method that realizes an image change similar to a hologram by using a complicated halftone dot configuration is disclosed.

  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 application for an anti-counterfeit information carrier that changes to completely different information by changing the angle has been filed (see, for example, Patent Document 1).

JP 2008-188973 A

  However, in the printed matter described in Patent Document 1, when a latent image is formed by mixing a luminescent pigment or a luminescent dye with transparent ink, the luminescent image that appears by irradiating the printed matter with UV light appears during regular reflection. There is a problem that the image is only the same as the latent image to be displayed.

  In order to make the latent image and the luminescent image different from each other, it is necessary to use two types of transparent ink, a transparent ink containing a luminescent pigment and a transparent ink containing no luminescent pigment. When included, it was necessary to use three types of inks in total. Even in this case, the luminescent image needs to have a design included in the image that appears at the time of regular reflection (for example, if the image at the time of regular reflection is an image of AB, the luminescent image should be A or B). It was impossible to make the image and the luminescent image completely different from each other.

  In view of the above circumstances, the present invention is a printed matter having an effect of switching an image between diffuse reflected light and regular reflected light using ink containing a glittering material and transparent ink, and appears at the time of regular reflection. It is an object of the present invention to provide a latent image printed matter that can enhance the effect of preventing forgery by making the latent image different from the light-emitting image that appears upon UV light irradiation.

  The latent image printed material according to the present invention includes a printed image on at least a part of a substrate, and the printed image includes a glittering material and emits light 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 including a conductive material is formed, the first image has a background image and an information image, and the first image element has a predetermined pitch in the background image. A plurality of background element groups arranged in a predetermined direction, and an information image is formed of a plurality of information element groups in which a plurality of second image elements are arranged in a predetermined direction at a predetermined pitch. , A first latent image image and a second latent image, and the first latent image image includes a plurality of third image elements arranged in a predetermined direction at a predetermined pitch. The second latent image is formed by a group, and the fourth image element has a predetermined pitch. Are formed by a plurality of second latent image element groups arranged in a predetermined direction, and the first image element, the second image element, and the fourth image element are adjacent or close to each other within a predetermined pitch. The first image element is arranged so that the third image element overlaps the first image element, and the first image is visible in the observation angle region where the diffuse reflected light is dominant. The first latent image is visible in the observation angle region where is dominant, and the second latent image is visible in the situation where UV light is irradiated.

  The latent image printed material according to the present invention is characterized in that the first image element, the second image element, the third image element, and the fourth image element are image lines or pixels.

  The latent image printed material according to the present invention is characterized in that the width of the third image element in the predetermined direction is equal to or smaller than the width of the first image element in the predetermined direction.

  The latent image printed material according to the present invention is characterized in that the image area ratio of the first image is formed within a range of 20% to 80%.

  The latent image printed material according to the present invention is formed such that the area ratio of the background image in the first image is in the range of 20% to 60%, and the area ratio of the information image in the first image is equal to the area ratio of the background image. It does not exceed and is formed within a range of 10% to 40%.

  The latent image printed material according to the present invention is characterized in that the predetermined pitch is formed within a range of 0.1 mm to 5 mm.

  According to the latent image printed matter of the present invention, an image formed with an ink containing a glittering material having UV absorbing ability and an image formed with a transparent ink containing a luminescent pigment are superposed according to a certain rule. Thus, it is possible to obtain a printed matter that can improve the forgery preventing effect between the latent image that appears during regular reflection and the light-emitting image that appears during UV light irradiation without increasing the number of colors.

It is explanatory drawing which shows the latent image printed matter by Embodiment 1 of this invention. (A) shows the image in the latent image printed matter, and is an explanatory view showing that this image includes the first image shown in (b) and the second image shown in (c). . (A) shows the 1st image in the latent image printed matter, and is an explanatory view showing that this image includes the background image shown in (b) and the information image shown in (c). (A) shows the 2nd image in the latent image printed matter, and this image contains the 1st latent image shown in (b), and the 2nd latent image shown in (c). It is explanatory drawing which shows this. It is explanatory drawing which shows that the 1st image in the latent image printed matter is partially enlarged, and that this image includes a first image line and a second image line. It is explanatory drawing which shows that the 2nd image in the latent image printed matter is partially enlarged, and that this image includes a third image line and a fourth image line. (A) is an enlarged view of the first image line included in the first image in the latent image printed material, and (b) is an enlarged image of the second image line included in the first image in the latent image printed material. It is explanatory drawing shown. (A) is an enlarged view of the third image line included in the second image in the latent image printed material, and (b) is an enlarged image of the fourth image line included in the second image in the latent image printed material. It is explanatory drawing shown. It is explanatory drawing which shows the positional relationship of the superimposition of the 1st, 2nd image line contained in the 1st image in the latent image printed matter, and the 3rd, 4th image line contained in the 2nd image. (A) shows an image that appears in the latent image print when the observer's viewpoint is in the observation angle region where diffuse reflected light is dominant, and (b) shows the specularly reflected light. (C) is an explanatory view showing an image appearing in the latent image printed material when irradiated with UV light. (A) shows specific numerical values of the first and second image lines included in the first image in the latent image printed material, and (b) is included in the second image in the latent image printed material. It is explanatory drawing which shows the specific numerical value of the 3rd, 4th drawing line. It is explanatory drawing which shows the latent image printed matter by Embodiment 2 of this invention. (A) shows the image in the latent image printed matter, and is an explanatory view showing that this image includes the first image shown in (b) and the second image shown in (c). . (A) shows the 1st image in the latent image printed matter, and is an explanatory view showing that this image includes the background image shown in (b) and the information image shown in (c). (A) shows the 2nd image in the latent image printed matter, and this image contains the 1st latent image shown in (b), and the 2nd latent image shown in (c). It is explanatory drawing which shows this. It is explanatory drawing which shows that the 1st image in the latent image printed matter is partially enlarged, and that this image includes a first pixel and a second pixel. It is explanatory drawing which shows that the 2nd image in the latent image printed matter is partially enlarged, and that this image includes a third pixel and a fourth pixel. It is explanatory drawing which shows the positional relationship of the superimposition of the 1st, 2nd pixel contained in the 1st image in a latent image printed matter, and the 3rd, 4th pixel contained in a 2nd image. (A) shows an image that appears in the latent image print when the observer's viewpoint is in the observation angle region where diffuse reflected light is dominant, and (b) shows the specularly reflected light. (C) is an explanatory view showing an image appearing in the latent image printed material when irradiated with UV light.

  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.

In general, when a transparent ink is used, a luminescent pigment, a luminescent dye, or the like is mixed in order to visualize the presence of the transparent ink for quality control. Latent image prints according to the following embodiments include different latent image images that are visualized by irradiating UV light, in addition to latent image images that are visualized under specular reflection light with a luminescent pigment, a luminescent dye, or the like.
(1) Embodiment 1

  A latent image printed matter according to Embodiment 1 of the present invention will be described with reference to the drawings.

  In the latent image printed material according to the first embodiment, an image is composed of image lines, and in the latent image printed material according to the second embodiment, an image is composed of pixels.

  Here, the image line is an image element formed by continuously arranging printing halftone dots, which are the minimum units constituting an image in a printed matter, without any gaps in a predetermined direction, for example, straight lines, curved lines, wavy lines, A broken line such as a dotted line or a broken line is included, and any shape of the image line is included in the image line in the present invention.

  A pixel is a group of image elements formed by collecting a plurality of printing halftone dots, which are the minimum unit constituting an image in a printed matter. For example, a pixel, a polygon including a circle, a triangle, a quadrangle, etc. A figure or a character or a symbol is included, and a change in shading is an area ratio, that is, a halftone dot shape expressed by the size of a point. Any pixel shape is included in a pixel in the present invention. And In addition, the image element is assumed to be either a pixel, an image line, or a combination thereof.

  In the first embodiment in which an image is constituted by an image line, the first image element in the means for solving the problem is the first image line, the background element group is the image line group, and the second image. The element is the second image line, the information element group is the image line group, the third image element is the third image line, the first latent image element group is the image line group, and the fourth image element is the fourth image element. The image line and the second latent image element group will be described as the image line group.

  FIG. 1 shows a latent image print (1) according to the first embodiment. The latent image print (1) has a print image (3) at least partially on the substrate (2), and the print image (3) includes a second image on the first image as will be described later. The images are overlapped.

  The substrate (2) may be any material as long as it has a flat surface, such as fine paper, coated paper, and plastic plate, and is not limited in terms of material, outer shape, dimensions, and the like.

  Further, the print image (3) is not limited as long as it includes a colored image line.

  The printed image (3) shown in FIG. 2 (a) has a second image (5) shown in FIG. 2 (c) on the upper surface of the first image (4) shown in FIG. 2 (b). ).

  Here, the first image (4) is an image that can be visually recognized under diffuse reflection light, and is formed of an ink containing a glittering material having a property of absorbing UV (ultraviolet) light (brilliant ink). The image area ratio (ratio of the image area in a certain area) is preferably in the range of 20 to 80%.

  The light reflection characteristic of glittering ink is that when the ink is printed on a general coated paper with a dot area ratio of 100%, the lightness value under specular reflection light is 100 or more, and under diffuse reflection light. It is desirable that the difference between the lightness (minimum lightness) and the lightness (maximum lightness) under regular reflected light is 50 or more. This is because, when an ink having a reflection characteristic lower than this is used, the disappearance effect of the first image (4) under specular reflection light is reduced, and the image change effect that is the effect of the present invention may be lost. This is because sex occurs.

  The second image (5) includes a first latent image that is visible under specular reflection light and a second latent image that is visible when irradiated with UV light, as will be described later. It is formed of a transparent ink containing a light emitting material such as a luminescent pigment and a luminescent dye. The emission color may be any. The ink desirably has a lower gloss and a matte tone than the ink forming the first image (4).

  This is the light reflection property of matte ink, but when the ink is printed on a general coated paper at a dot area ratio of 100%, the lightness value under specular reflection light is 20 or more lower than the lightness value of the glitter ink. It is desirable that the difference between the brightness under diffuse reflected light (minimum brightness) and the brightness under regular reflected light (maximum brightness) be 30 or less. This is because an image appearing under specular reflection light is visualized by the difference in reflectance between the glitter ink and the mat ink, and therefore when the difference in brightness between the glitter ink and the mat ink is less than 20, the image This is because it becomes difficult to visually recognize the above.

  The first image (4) shown in FIG. 3 (a) includes the background image (6) shown in FIG. 3 (b) and the information image (7) shown in FIG. 3 (c). It is out. The background image (6) and the information image (7) are formed with the same glitter ink. Here, the information “Japan” appears from the information image (7).

  The background image (6) preferably has a constant gradation, that is, a constant line area ratio, and an area ratio in the range of 20 to 60%. This is because when an image is formed with an area ratio of less than 20%, the visibility of an image that appears under specular reflection light becomes low. In addition to the background image (6), the information image (7) and the non-image area (11) described later are essential for the first image (4), and the ratio between these image lines and areas is essential. In view of the above, it is desirable to keep the area ratio of the background image (6) at 60% or less.

  The information image (7) has significant information and may be not only a binary image but also a multi-tone image, and the area ratio is preferably in the range of 10 to 40%. This is because when an image is formed with an area ratio of less than 10%, a sufficient density cannot be obtained and only an image with low visibility can be formed. Further, in order to form with an area ratio exceeding 40%, it is necessary to greatly reduce the image area ratio of the background image (6) and the non-image area (11) to be described later. This is because the visibility of an image appearing at the point of time and the visibility of an image appearing during UV irradiation are greatly impaired.

  The second image (5) shown in FIG. 4 (a) includes the first latent image (8) shown in FIG. 4 (b) and the second latent image shown in FIG. 4 (c). Image image (9). The first latent image (8) is an image that appears at the time of specular reflection, has significant information for causing the image to appear, and may have not only a binary image but also multiple gradations. The area ratio needs to be in a range not exceeding the area ratio of the background image (6) shown in FIG. Here, a “cherry blossom pattern” appears in the first latent image (8).

  The second latent image (9) is an image that appears at the time of UV light irradiation, has significant information for causing the image to appear, and is not limited to a binary image but may have multiple gradations. The area ratio is determined by a value obtained by subtracting the maximum area ratio of the first image (4) from 100%, and it is desirable to have 20% or more. Here, the characters “OK” appear in the second latent image (9).

  In FIG. 5, a first image line (10) and an information image (7) forming a background image (6) included in the first image (4) by enlarging a part of the first image (4). The arrangement of the non-image area (11) in which none of the second image line (12), the first image line (10), and the second image line (12) forming the image area is shown.

  The first image line (10) and the second image line (12) are regularly arranged in a predetermined direction in a predetermined manner. Here, the predetermined direction means a direction orthogonal to the image line, that is, a vertical direction in the drawing.

  The first image line (10) has an image line width (W1) and is arranged at a predetermined pitch (P1) to form the image line group, thereby forming the background image (6). The pitch (P1) is preferably set in consideration of print reproducibility, image resolution, and the like, and may be set to 0.1 to 5 mm, for example.

  The second image line (12) has an image line width (W3), and is arranged in a predetermined direction at a predetermined pitch (P1) in the same manner as the first image line (10), thereby forming an image line group. An information image (7) is formed.

  The non-image area (11) has a width (W2), and a fourth image line (14) for forming the second latent image (9) is disposed in this area, as will be described later. In order to secure the width (W2) of the non-image area (11), the second image line (12) is arranged close to the first image line (10) within the range of the pitch (P1). It is desirable.

  In the case where the first image line (10) and the second image line (12) are formed to overlap each other, unnecessary shading occurs in the overlapped area, and the shading is under specular reflection light. This is reflected in the appearing second image (5), which is not desirable.

  The first image line (10) and the second image line (12) are not necessarily formed so as to be adjacent to each other, but may be formed close to each other.

  In the partially enlarged view in FIG. 5, the first image line (10) is shown as a horizontal stripe image line, and the second image line (12) is shown as a vertical stripe image line. Similarly, in the partially enlarged view in FIG. 8 to be described later, the third image line (13) and the fourth image line (14) are indicated by hatched image lines. However, these displays are performed to make it easy to distinguish the configuration of each image line, and each actual image line is not formed by vertical stripes, diagonal stripes, or the like.

  In FIG. 6, a part of the second image (5) is enlarged to form a third image line (13) and a second latent image (9) that form the first latent image (8). The arrangement of the fourth image (14) to be performed is shown.

  The third image line (13) has an image line width (W4) and is arranged in a predetermined direction at a pitch (P1) to form an image line group, thereby forming the first latent image (8). .

  The fourth image line (14) has an image line width (W5) and is arranged in a predetermined direction at a pitch (P1) to form the image line group, thereby forming a second latent image (9). . The fourth image line (14) is formed in the non-image area (11) described above.

  Color pigments may be added to the first image line (10) and the second image line (12). The color of the color pigment may be any hue such as black, red, blue or yellow. For example, the ink forming the first image line (10) and the second image line (12) may be mixed with a color pigment together with a glittering material, or the inks may be mixed together. To form the same image as the first image (4) by the first image line (10) and the second image line (12), and then the same first image (4) with ink containing a glittering material. May be formed by overlapping.

  However, when an excessive amount of pigment is mixed, the gradation difference (darkness difference) in the first image (4) becomes large and the mixing ratio of the glittering material in the ink decreases, or regular reflection occurs. A phenomenon that the first image (4) does not disappear sufficiently in observation under light may occur. Therefore, when mixing pigments, or when mixing inks, even when mixing colored pigments of any color, a range that does not exceed one half of the blending ratio of the glittering material in the ink It is desirable to keep it on.

  When a color is imparted by previously forming the same image as the first image (4) with colored ink on the ground, a sufficient switching effect can be obtained regardless of the color and the density of the ink used. Can do.

  In addition, you may use common metal powder pigments, such as aluminum powder, copper powder, zinc powder, tin powder, brass powder, iron phosphide, titanium oxide, or scaly mica powder, as the above-mentioned glitter material.

  It is widely known that metal powders such as titanium, aluminum, zinc, and brass mentioned as glittering materials have a property of absorbing ultraviolet rays, so-called ultraviolet absorbing ability, and these materials have been conventionally used for UV cut glass and UV. Generally used as a material for cut film. Titanium oxide is known to have a high ultraviolet absorber function, and is used for imparting a UV cut function in cosmetics. In addition, the present applicant has already applied for a printed matter in combination with an ultraviolet absorber typified by titanium oxide and a fluorescent light emitting ink in Japanese Patent No. 3680908 and Japanese Patent No. 4487090. For this reason, it is common to obtain an excellent UV absorption effect by printing an ultraviolet absorber on top of the fluorescent ink, but the fluorescent ink is formed on the UV absorber. However, the same effect can be obtained.

  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 (4). Color flip-flop property (characteristic that changes not only lightness but also color tone) that changes not only the color property (mainly the property that changes only the lightness) but also the color tone of the first image (4) can be provided. .

  A functional material such as an IR absorbing pigment, a photochromic pigment, a temperature indicating material, or a thermochromic material may be added to the glittering material. However, when a functional material such as an IR absorbing pigment, a photochromic pigment, a temperature indicating material, or a thermochromic material is added, it needs to be added within a range that does not affect the effect of the latent image printed material in the present invention.

  The ink that forms the third image line (13) and the fourth image line (14) 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 rather than the ink that forms the first image line (10) and the second image line (12). When mat-type ink is used, the ratio of blocking the amount of light reaching the first image (4) increases, and the visibility of the second image (5) increases.

  In addition to light-emitting pigments such as fluorescent pigments, phosphorescent pigments, and phosphorescent pigments, functional materials such as IR absorbing pigments, photochromic pigments, temperature indicating materials, and thermochromic materials may be added to the transparent ink. However, when adding functional materials such as IR absorbing pigments, photochromic pigments, temperature indicating materials, and thermochromic materials, it is necessary to select pigments that do not lose transparency, and the effect of the latent image printed matter in the present invention is not affected. Need to add in range.

  FIG. 7A shows an arrangement of the first image line (10) constituting the background image (6) by enlarging a part of the background image (6) included in the first image (4).

  As described above, the first image line (10) has an image line width (W1), and is arranged in a predetermined direction at a predetermined pitch (P1) to form the image line group, thereby forming the background image (6). Form.

  FIG. 7B shows an arrangement of the second image line (12) constituting the information image (7) by enlarging a part of the information image (7) included in the first image (4).

  The second image line (12) has an image line width (W3), and is arranged in a predetermined direction at a predetermined pitch (P1) in the same manner as the first image line (10), thereby forming an image line group. An information image (7) is formed.

  In FIG. 8A, a part of the first latent image (8) included in the second image (5) is enlarged, and the third image line (13) constituting the image (8) is enlarged. Indicates placement.

  The third image line (13) has an image line width (W4) and is arranged in a predetermined direction at a pitch (P1) to form an image line group, thereby forming the first latent image (8). .

  In FIG. 8B, a part of the second latent image (9) included in the second image (5) is enlarged, and the fourth image line (14) constituting the image (9) is enlarged. Indicates placement.

  The fourth image line (14) has an image line width (W5) and is arranged in a predetermined direction at a pitch (P1) to form the image line group, thereby forming a second latent image (9). .

  FIG. 9 shows an appropriate positional relationship in superposition of the first image (4) and the second image (5). The first image line (10) constituting the background image (6) included in the first image (4) and the second image line (12) constituting the information image (7) have the same pitch (P1). ) In a predetermined direction.

  The third image line (13) constituting the first latent image (8) included in the second image (5) is formed so as to be superimposed on the first image line (10).

  The fourth image line (14) constituting the second latent image (9) included in the second image (5) is the first image line (10) and the second image line (12). They are formed in the non-image area (11) where none is formed.

  Here, any image line should not be formed on top of the second image line (12). As a printing order, after printing the first image (4), the second image (5) is printed.

  A third image line (13) formed of transparent ink is formed on the first image line (10) formed of glittering ink. At the time of diffuse reflection, since the third image line (13) is invisible, the first latent image (8) composed of the third image line (13) does not appear. During regular reflection, the third image line (13) has a strong contrast with the first image line (10), and the first latent image (8) appears and becomes visible. However, when UV irradiation is performed, UV light is absorbed by the first image line (10) formed of the glitter ink, so that the third image line (13) is suppressed from emitting light and the first latent image image. (8) does not appear.

  In the non-image area (11), the fourth image line (14) formed of transparent ink does not appear in either the diffuse reflection or the regular reflection, and the second latent image (9). Is invisible. At the time of UV irradiation, the fourth image line (14) emits light strongly, and the second latent image (9) appears and becomes visible.

  Here, the third image line (13) or the fourth image line formed with transparent ink on the second image line (12) forming the information image (7) in the first image (4). When (14) is formed in an overlapping manner, the information image (7) does not disappear in the region where the transparent ink is overlapped under specular reflection light, and the appearance of the first latent image (8) is prevented. Therefore, on the second image line (12), neither the third image line (13) nor the fourth image line (14) made of transparent ink is formed so as to overlap the information under specular reflection light. The image (7) can be completely lost.

  The first image line (10) constituting the background image (6) of the first image (4) and the second image line (12) constituting the information image (7) may be formed adjacent to each other. Desirably, the fourth image line (14) constituting the second latent image (9) of the second image (5) is overlapped with the first image line (10) and the second image line (12). So that the image line width (W4) of the third image line (13) is within the image line width (W1) of the first image line (10) (W4 ≦ W1) It is necessary to design.

  The greater the area ratio of the third image line (13), the higher the visibility of the first latent image (8) that appears under specular reflection light. For this reason, it is desirable to design with a line width substantially the same as the line width (W1) of the first line (10). However, as the value of the image line width (W4) of the third image line (13) approaches the image line width (W1) of the first image line (10), the tolerance for misalignment at the time of manufacture becomes smaller. Become. Therefore, it is desirable to design the image line width (W1) and the image line width (W4) in consideration of the printing accuracy in the printing machine.

  As described above, the fourth image line (14) constituting the second latent image (9) does not overlap the second image line (12) constituting the information image (7). This is necessary for improving the visibility of the second latent image (9). However, even if the third image line (13) constituting the first latent image (8) is slightly overlapped on the second image line (12) due to misalignment of printing at the time of printing or the like, The third image line (13) has a large area overlapping the first image line (10) constituting the background image (6). For this reason, the influence on the visibility of the second latent image (9) is small. Therefore, a case where the third image line (13) slightly overlaps the second image line (12) is also included in the technical scope of the present invention.

  FIGS. 10A to 10C show the positional relationship between the light source (15) or the UV light source (17), the latent image printed matter (1), the observer (16a), and the visible state of the latent image printed matter (1) in each. Indicates.

  As shown in FIG. 10 (a), the angle of light incident on the latent image printed matter (1) under diffuse reflected light and the angle connecting the observer (16a) and the latent image printed matter (1) are large. When observed in a different state, the first image (4) is visually recognized by the observer (16a).

  As shown in FIG. 10B, the latent image printed matter (1) is subjected to specular reflection light, that is, the angle of light incident on the latent image printed matter (1), the observer (16a) and the latent image printed matter (1 ), The first latent image (8) is visually recognized by the observer (16a).

  As shown in FIG. 10C, when the latent image printed matter (1) is observed during UV light irradiation by the UV light source (17), the observer (16a) receives the second latent image (9). Visible.

  Thus, three kinds of images are visually recognized by an excellent switch effect according to the observation state.

  FIG. 11 shows the line width (W1) and the second line (12) of the first line (10) constituting the first image (4) in the latent image print (1) according to the first embodiment. ) Image line width (W3), non-image area (11) width (W2), image line width (W4) of the third image line (13) constituting the second image (5), fourth An example of specific numerical values of the image line width (W5) and the pitch (P1) of the image line (14) is shown.

  According to an example in the first embodiment, the image line width (W1) of the first image line (10) constituting the first image (4) is set to 0.20 mm, and the second image line (12). The image line width (W3) of the second image (5) is 0.15 mm, the width (W2) of the non-image area (11) is 0.15 mm, and the third image line (13) of the second image (5) is formed. The line width (W4) is set to 0.18 mm, the line width (W5) of the fourth line (14) is set to 0.15 mm, and the pitch (P1) is set to 0.5 mm.

  Moreover, you may form the 1st image line (10) and the 2nd image line (12), for example using silver metallic ink (product made from UV NO3 silver T & K TOKA).

  The third image line (13) and the fourth image line (14) may be formed using, for example, an ink in which 2% of a green luminescent pigment is mixed with OP varnish (matt medium manufactured by T & K TOKA).

According to the first embodiment, the first latent image and UV light appearing at the time of regular reflection in a printed matter having the effect of switching between the first and second images under diffuse reflection light and regular reflection light. The second latent image that appears at the time of irradiation can be made different from the image, and a higher forgery prevention effect can be obtained.
(2) Embodiment 2

  A latent image printed matter according to Embodiment 2 of the present invention will be described with reference to the drawings.

  In the latent image printed material according to the second embodiment, an image is configured by pixels as image elements, and the pixels correspond to a minimum unit configuring an image in the printed material.

  In the second embodiment in which an image is configured by pixels, the first image element in the means for solving the problem is the first pixel, the background element group is the pixel group, and the second image element is the second image element. 2 pixels, the information element group is the pixel group, the third image element is the third pixel, the first latent image element group is the pixel group, the fourth image element is the fourth pixel, and the second latent image. The image element group will be described as a pixel group.

  FIG. 12 shows a latent image print (21) according to the second embodiment. The latent image print (21) has a print image (23) at least partially on the substrate (22), and the second image is formed on the first image in the print image (23). Has been. The base material (22) may be any material as long as it has a flat surface, such as fine paper, coated paper, and plastic board, like the base material (2) of the first embodiment. It is not limited regarding a shape, a dimension, etc.

  The print image (23) may be any image that includes colored pixels, and is not limited in color or the like.

  The print image 23 shown in FIG. 13A is formed on the upper surface of the first image 24 shown in FIG. 13B, and the second image 25 shown in FIG. Is included.

  The first image (24) is an image that is visible under diffuse reflected light, is formed of ink containing a glittering material having a property of absorbing UV light, and has a pixel area ratio (occupying a certain area) The ratio of the pixel area) is preferably in the range of 20 to 80%.

  Regarding the light reflection characteristics of the glitter ink, as described in Embodiment 1, when the ink is printed on a general coated paper with a dot area ratio of 100%, the brightness value under the regular reflection light is as follows. It is desirable that the difference between the brightness under diffuse reflection light and the brightness under regular reflection light is 50 or more.

  The second image (25) includes a first latent image that is visible under specular reflection light, and a second latent image that is visible when irradiated with UV light. It is formed of a transparent ink containing a light emitting material such as a dye. It is desirable that the ink has a lower gloss and a matte tone than the ink that forms the first image (24).

  Regarding the light reflection characteristics of the mat-type ink, as described in the first embodiment, when the ink is printed on a general coated paper at a dot area ratio of 100%, the brightness value under the regular reflection light is bright. It is desirable that the difference between the lightness under diffuse reflection light and the lightness under regular reflection light is 30 or less than the lightness value of the ink.

  The first image (24) shown in FIG. 14 (a) includes the background image (26) shown in FIG. 14 (b) and the information image (27) shown in FIG. 14 (c). It is out. The background image (26) and the information image (27) are formed of the same glitter ink. Here, the information “Japan” appears in the information image (27).

  The background image (26) has a constant gradation, that is, a constant pixel area ratio, and the area ratio is preferably in the range of 20 to 60%. This is because when an image is formed with an area ratio of less than 20%, the visibility of an image that appears under specular reflection light becomes low. In addition to the background image (26), the first image (24) requires an information image (27) and a non-pixel area (31) to be described later, and the ratio of these pixels and areas is taken into consideration. Then, it is desirable to keep the area ratio of the background image (6) at 60% or less.

  The information image (27) has significant information for causing the latent image to appear, and is not limited to a binary image but may have multiple gradations, and the area ratio is within a range of 10 to 40%. It is desirable that This is because when an image is formed with an area ratio of less than 10%, a sufficient density cannot be obtained and only an image with low visibility can be formed. Further, in order to form with an area ratio exceeding 40%, it is necessary to greatly reduce the image area ratio of the background image (26) and the non-image area (31) to be described later. This is because the visibility of an image appearing at the point of time and the visibility of an image appearing during UV irradiation are greatly impaired.

  The second image (25) shown in FIG. 15 (a) includes the first latent image (28) shown in FIG. 15 (b) and the second latent image shown in FIG. 15 (c). Image image (29). The first latent image (28) is an image that appears at the time of regular reflection. The first latent image (28) may have significant information for causing the image to appear, and may have multiple gradations. It is necessary to be within a range not exceeding the area ratio of 26). Here, a “sakura pattern” appears from the first latent image (28).

  The second latent image (29) is an image that appears at the time of UV light irradiation, may have significant information for causing the image to appear, and may have multiple gradations, and the area ratio is 100%. It is determined by a value obtained by subtracting the maximum area ratio of the first image (24) from the first image (24). Here, the characters “OK” appear in the second latent image (29).

  FIG. 16 shows a first pixel (30) and an information image (27) that form a background image (26) included in the first image (24) by enlarging part of the first image (24). The arrangement of the non-pixel region (31) in which none of the second pixel (32), the first pixel (30), and the second pixel (32) to be formed exists is shown. The first pixel (30) and the second pixel (32) are regularly arranged in a predetermined direction at a predetermined pitch, here in a matrix form in the vertical and horizontal directions in the figure at a predetermined pitch.

  The first pixel (30) has a pixel width, here a circular pixel, for example, a diameter of 0.4 mm, and a predetermined pitch (P1), for example, a pixel group arranged in a matrix at a pitch of 0.6 mm. To form a background image (26).

  The second pixel (32) is a pixel having a pixel width, here a circular pixel, for example, having a diameter of 0.3 mm, and the same pitch (P1) as the first pixel (30), here a matrix with a pitch of 0.6 mm. An information image (27) is formed by forming a pixel group by arranging the pixel groups.

  In the non-pixel region (31), a fourth pixel (34) that forms the second latent image (29) is disposed as described later. The first pixel (30) and the second pixel (32) are not necessarily formed adjacent to each other, but the fourth pixel (34) can be arranged in the non-pixel region (31). In addition, it is necessary to arrange the second pixel (32) with respect to the first pixel (30).

  In the case where the first pixel (30) and the second pixel (32) are formed to overlap, an unnecessary density occurs in the overlapped area, and the density appears under the regular reflection light. It is reflected in the image (25) and is not desirable.

  In the partially enlarged view of FIG. 16, the first pixel (30) is shown as a horizontal stripe pixel, and the second pixel (32) is shown as a vertical stripe pixel. Similarly, in a partially enlarged view in FIG. 17 to be described later, the third pixel (33) and the fourth pixel (34) are indicated by hatched pixels. However, these displays are performed to make it easy to distinguish the configuration of each pixel, and the actual pixels are not formed by vertical stripes, diagonal stripes, or the like.

  In FIG. 17, a part of the second image (25) is enlarged to form a third pixel (33) that forms the first latent image (28) and a second latent image (29). The arrangement of the fourth pixel (34) is shown.

  The third pixel (33) has a pixel width, here a circular pixel, for example, has a diameter of 0.35 mm, and has a predetermined pitch (P1) similar to the first pixel (30). A first latent image (28) is formed by forming a group of pixels arranged in a matrix of 6 mm.

  The fourth pixel (34) has a pixel width of, for example, a diameter of 0.20 mm, and is arranged at a pitch of 0.6 mm as a predetermined pitch (P1) to form a second latent image ( 29). The fourth pixel (34) is formed in the non-pixel region (31) described above.

  Similar to the first embodiment, a coloring pigment may be applied to the first pixel (30) and the second pixel (32). The color of the color pigment may be any hue such as black, red, blue or yellow. For example, the ink forming the first pixel (30) and the second pixel (32) may be mixed with a color pigment together with a glittering material, or the inks may be mixed together. The same image as the first image (24) by the first pixel (30) and the second pixel (32) is formed, and then the same first image (24) is overlapped with ink containing a glittering material. It may be formed.

  As the glitter material, a general metal powder pigment such as aluminum powder, copper powder, zinc powder, tin powder, brass powder, iron phosphide, titanium oxide, or scaly mica powder may be used.

  When a general pearl pigment such as an iris pearl pigment and scale pigment, 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 (24). Color flip-flop property (characteristic that changes not only lightness but also color tone) that changes the color tone of the first image (24) as well as color properties (mainly the property that changes only lightness) can be provided. .

  Functional materials such as IR absorbing pigments, photochromic pigments, temperature indicating materials, and thermochromic materials may be added to the glittering material. However, when a functional material such as an IR absorbing pigment, a photochromic pigment, a temperature indicating material, or a thermochromic material is added, it needs to be added within a range that does not affect the effect of the latent image printed material in the present invention.

  The ink forming the third pixel (33) and the fourth pixel (34) needs to be transparent. The ink may be glossy or matte as long as it is transparent, but it is preferable to use a matte transparent ink rather than the ink that forms the first pixel (30) and the second pixel (32). When mat-type ink is used, the ratio of blocking the amount of light reaching the first image (24) increases, and the visibility of the second image (25) increases.

  In addition to light-emitting pigments such as fluorescent pigments, phosphorescent pigments, and phosphorescent pigments, functional materials such as IR absorbing pigments, photochromic pigments, temperature indicating materials, and thermochromic materials may be added to the transparent ink. However, when adding functional materials such as IR absorbing pigments, photochromic pigments, temperature indicating materials, and thermochromic materials, it is necessary to select pigments that do not lose transparency, and the effect of the latent image printed matter in the present invention is not affected. Need to add in range.

  FIG. 18 shows an appropriate positional relationship in the superposition of the first image (24) and the second image (25). The first pixel (30) constituting the background image (26) included in the first image (24) and the second pixel (32) constituting the information image (27) are at the same pitch (P1). Has been placed.

  The third pixel (33) constituting the first latent image (28) included in the second image (25) is formed so as to overlap the first pixel (30).

  The fourth pixel (34) constituting the second latent image (29) included in the second image (25) forms both the first pixel (30) and the second pixel (32). It is formed in a non-pixel region (31) that has not been formed.

  Here, any pixel should not be formed on top of the second pixel (32). As a printing order, after printing the first image (24), the second image (25) is printed.

  A third pixel (33) made of transparent ink is formed on the first pixel (30) made of glitter ink. At the time of diffuse reflection, since the third pixel (33) is invisible, the first latent image (28) composed of the third pixel (33) does not appear. During regular reflection, the third pixel (33) has a strong contrast with respect to the first pixel (30), and the first latent image (28) appears and becomes visible. However, since UV light is absorbed by the first pixel (30) formed of glittering ink during UV irradiation, the third pixel (33) is prevented from emitting light and the first latent image (28). ) Does not appear.

  In the non-pixel region (31), the fourth pixel (34) formed of the transparent ink does not appear in any of diffuse reflection and regular reflection, and the second latent image (29) is invisible. State. During UV irradiation, the fourth pixel (34) emits light strongly, and the second latent image (29) appears and becomes visible.

  Here, the third pixel (33) or the fourth pixel (34) formed of transparent ink on the second pixel (32) forming the information image (27) in the first image (24). In the case where the transparent ink is overlapped, the information image (27) does not disappear under the specular reflection light in the region where the transparent ink overlaps, and the appearance of the first latent image (28) is prevented. Therefore, neither the third pixel (33) nor the fourth pixel (34) made of transparent ink is formed on the second pixel (32) so as to overlap the information image (27 ) Can be completely eliminated.

  Desirably, the first pixel (30) constituting the background image (26) of the first image (24) and the second pixel (32) constituting the information image (27) are formed adjacent to each other, The fourth pixel (34) constituting the second latent image (29) of the second image (25) is formed so as not to overlap the first pixel (30) and the second pixel (32). The pixel width of the third pixel (33) ≦ the first pixel (30) so that the pixel width of the third pixel (33) falls within a width within the pixel width of the first pixel (30). ) Needs to be designed with a pixel width.

  The greater the pixel area ratio of the third pixel (33), the higher the visibility of the first latent image (28) that appears under specular reflection light. For this reason, it is desirable to design with a pixel width substantially the same as the pixel width of the first pixel (30). However, as the value of the pixel width of the third pixel (33) approaches the pixel width of the first pixel (30), the tolerance for misalignment at the time of manufacture decreases. Therefore, it is desirable to design the pixel width of the first pixel (30) and the pixel width of the third pixel (33) in consideration of the printing accuracy in the machine that performs printing.

  As described above, the fourth pixel (34) constituting the second latent image (29) does not overlap the second pixel (32) constituting the information image (27). This is necessary to improve the visibility of the second latent image (29). However, even if the third pixel (33) constituting the first latent image (28) slightly overlaps the second pixel (32) due to misalignment during printing, the third pixel The pixel (33) has a large area overlapping the first pixel (30) constituting the background image (26). For this reason, the influence on the visibility of the second latent image (29) is small. Therefore, the case where the third pixel (33) slightly overlaps the second pixel (32) is also included in the technical scope of the present invention.

  FIGS. 19A to 19C show the positional relationship between the light source (35) or the UV light source (37), the latent image printed matter (21), the observer (36a), and the visible state of the latent image printed matter (21) in each. Indicates.

  As shown in FIG. 19A, the angle of light incident on the latent image print (21) under diffuse reflection light and the angle connecting the observer (36a) and the latent image print (21) are large. When observed in a different state, the first image (24) is visually recognized by the observer (36a).

  As shown in FIG. 19B, the latent image printed matter (21) is subjected to specular reflection, that is, the angle of light incident on the latent image printed matter (21), the observer (36a) and the latent image printed matter (21 ), The first latent image (28) is visually recognized by the observer (36a).

  When the latent image print (21) is observed during UV light irradiation by the UV light source (37) as shown in FIG. 19 (c), the observer (36a) receives the second latent image (29). Visible. Thus, three kinds of images are visually recognized by an excellent switch effect according to the observation state.

  According to the second embodiment, similar to the first embodiment, a printed matter having an effect of switching the first and second images under diffuse reflection light and regular reflection light appears at regular reflection. The first latent image and the second latent image that appears when UV light is irradiated can be different images, and a higher forgery prevention effect can be obtained.

  The latent image printed matter can be formed by any printing method such as offset printing, flexographic printing, letterpress printing, gravure printing, screen printing, and intaglio printing. If metal ink can be used, it can also be formed by various digital output machines such as IJP, laser printer, sublimation printer, etc. In this case, the information of one output item is changed. In other words, so-called variable printing can be performed.

  The above embodiments are merely examples, and various modifications can be made within the technical scope of the present invention.

1, 21 Latent image printed matter 2, 22 Base material 3, 23 Print image 4, 24 First image 5, 25 Second image 6, 26 Background image 7, 27 Information image 8, 28 First latent image 9 , 29 Second latent image 10 First image line 11 Non-image area 12 Second image line 13 Third image line 14 Fourth image line 15, 35 Light sources 16a, 16b, 16c, 36a, 36b , 36c, observer 17, 37 light source 30 first pixel 31 non-pixel region 32 second pixel 33 third pixel 34 fourth pixel

Claims (6)

Provide a printed image on at least a part of the substrate,
In the printed image, a second image formed of a transparent material including a luminescent material is formed on a first image formed of a material having a color different from that of the base material including a glittering material. And
The first image has a background image and an information image,
The background image is formed of a background element group in which a plurality of first image elements are arranged in a predetermined direction at a predetermined pitch, and the information image includes a plurality of second image elements in the predetermined direction at the predetermined pitch. Formed by arranged information elements,
The second image has a first latent image and a second latent image,
The first latent image is formed by a first latent image element group in which a plurality of third image elements are arranged in the predetermined direction at the predetermined pitch, and the second latent image is A plurality of fourth image elements are formed by a second latent image element group arranged in the predetermined direction at the predetermined pitch;
Within the predetermined pitch, the first image element, the second image element, and the fourth image element are arranged adjacent to or in close proximity to each other, and the third image is placed on the first image element. The elements are overlapped,
The first image is visible in an observation angle region where diffuse reflection light is dominant, and the first latent image is visible in an observation angle region where specular reflection light is dominant, and is irradiated with UV light. The printed latent image is characterized in that the second latent image can be visually recognized in the above situation. The first image element, the second image element, the third image element, and the fourth image element are at least one of an image line and a pixel, or a combination thereof, respectively. The latent image printed matter according to 1. The latent image printed matter according to claim 1, wherein a width of the third image element in the predetermined direction is equal to or less than a width of the first image element in the predetermined direction. The latent image printed matter according to any one of claims 1 to 3, wherein the image area ratio of the first image is formed within a range of 20% to 80%. The area ratio of the background image in the first image is formed within a range of 20% to 60%, the area ratio of the information image in the first image does not exceed the area ratio of the background image, The latent image printed matter according to claim 4, wherein the latent image printed matter is formed within a range of 10% to 40%. The latent image printed matter according to claim 1, wherein the predetermined pitch is formed within a range of 0.1 mm to 5 mm.

Images