JP2012056227A - Latent image printed matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide ordinary visible light in the field of valuable printed matter such as banknotes, passports, securities, identification cards, cards, and passports, which are security printed matter requiring anti-duplication measures and anti-counterfeit measures. Provided is a special image composition, and a latent image print formed thereby, in which an image that can be observed below changes to a completely different image when observed under certain conditions.
A printed matter in which a first image is formed by a glittering material on a second image formed by a penetrating ink, the image being viewed under diffuse reflected light, and specularly reflected light. A latent image printed matter that allows the image viewed under the image to be uncorrelated, and in addition, when viewed with transmitted light, can be viewed with a negative-positive relationship with the image viewed under specular reflection light. It is.
[Selection] Figure 1

Description

  The present invention is observed under ordinary visible light in the field of valuable printed matter such as banknotes, passports, securities, identification cards, cards, and passports, which are security printed matter that requires measures to prevent duplication and counterfeiting. The present invention relates to a special image configuration in which an image that can be changed to a completely different image when observed under specific conditions, and a latent image printed matter formed thereby.

  Recent advances in digital devices such as scanners, printers, and color copiers have made it possible to easily produce sophisticated copies of security prints. Therefore, in order to prevent duplication and forgery as described above, various anti-counterfeit technologies that are not reproducible are required for duplication by copy or the like represented by squeeze.

  As an example of the penetration technique, based on pre-input image pattern information, a predetermined part of the sheet base material surface is irradiated with laser light and partially removed so as not to penetrate the sheet base material of the irradiation part, and half cut A watermark image in which a watermark image of a mode is formed on a sheet surface is disclosed (for example, see Patent Document 1).

  In addition, the above-described anti-counterfeiting technology is a technology configured by combining a complex pixel configuration and image line configuration with various functional inks having special functions, and is visible under normal light. There is a technique having a so-called image change effect in which an image and a latent image observed under a specific condition are different images having no correlation.

  The present applicant uses two inks as a pair ink that are observed in the same color under diffuse reflection light but are observed in different colors under regular reflection light, and have a special halftone dot configuration. It is a printed matter that has a so-called change effect, in which an image that is visually recognized under observation under diffuse reflected light and an image that is visible under observation under regular reflected light are different images that have no correlation. An invention relating to the latent printed matter that has been featured has already been filed (for example, see Patent Document 2).

  In addition, the present applicant, when printed on a substrate, is observed in the same color under reflected light, but uses two inks having different transmittances as a pair ink, and has a special halftone dot image. A latent image characterized by having a change effect, wherein the image that can be observed under reflected light and the image that can be observed under transmitted light are different images having no correlation at all An invention relating to a printed matter has already been filed (for example, see Patent Document 3).

Japanese Patent Laid-Open No. 10-236000 Japanese Patent Application No. 2009-267329 Japanese Patent Application No. 2010-008034

  With respect to the technique of Patent Document 2, the latent image can be visually recognized only when observed under specular reflection light. With respect to the technique of Patent Document 3, the latent image is observed only when observed under transmitted light. It is a configuration that allows the user to visually recognize an image, and these are based on one specific condition (under specular reflection light or transmitted light) that is different from that under diffuse reflection light, based on an image observed under diffuse reflection light. (Below) was a technology that allowed the latent image to be visually recognized. However, this technology means that the environment that can authenticate the security printed material is limited, and considering the nature of the security printed material that may perform the authenticity determination in any environment and situation. It was a problem to be solved. For example, it is possible to cope with this problem by forming both of the techniques of Patent Document 2 and Patent Document 3 in one security print, but in that case, the number of printing colors and the print area are increased. Therefore, there has been a demand for a technique in which a latent image can be visually recognized under a plurality of conditions and an environment in which authenticity can be determined is not limited in spite of being one technique.

  In addition, regarding the techniques described in Patent Document 2 and Patent Document 3, when two images are combined to form a printed matter, the two images must be printed with high accuracy. When the printing is slightly shifted, the latent image that should be observed under diffuse reflection light is visible, and the visible image is visible as an unclear image. was there.

  In addition, security printed materials that require anti-counterfeiting effects are required to be manufactured with a highly productive printing method as before, and at the same time, there is a technology that makes it difficult to produce copies using the latest digital equipment. It has been demanded.

  The act of determining authenticity under specularly reflected light can be done with a small movement that is invisible to the human eye, just tilting the printed material slightly with respect to the lighting, but it is strongly influenced by the influence of light in the viewing environment. Therefore, it is difficult to say that the authenticity is always high (for example, if there is a large window in the authentication environment, the view is different between daytime and night).

  On the other hand, the watermark technique described in the cited document 1 is an authenticity authentication technique with extremely high authenticity, but the act of seeing through the printed material often involves a conspicuous action. Truth discrimination in face-to-face sales needs to be done quickly while the customer is present, but for example, at the cash register at a supermarket or convenience store, the act of seeing through the money passed from the customer is done in front of the customer This is considered to be rude in the current Japanese sense and is not an easy act.

  As described above, in the conventional technology, it is possible to determine authenticity with a small operation that is invisible to the human eye, but on the other hand, the authenticity is low, the authenticity is high, but a conspicuous operation is required, etc. Had.

  The present invention aims to solve the above-described problems, and is a printed matter having an image change effect that can be formed by simply superimposing two images, and is an image that is visible under diffuse reflected light. And an image viewed under specular reflection light is an image that has no correlation, and in addition, an image viewed under specular reflection light can be viewed even when viewed with transmitted light, and The present invention relates to a latent image printed matter that can be formed by a highly productive offset printing method.

  In the latent image printed material according to the present invention, a printed image having a color different from that of the substrate is formed on at least a part of the substrate, and the printed image includes a first image and a second image, The image is formed by solid printing with a colorless and transparent penetrating second ink, and the first image is formed on the second image with the first ink containing the glittering material. One image is divided into an information part in which a plurality of information elements are regularly arranged and a background part in which a plurality of background elements are regularly arranged at an area ratio different from that of the information part. The background element is formed so as not to overlap, and when observed under diffuse reflection, only the first image is visible, and when observed under specular reflection, only the second image is visible. And when viewed under transmitted light, the second image viewed under specularly reflected light Characterized in that it is visually recognized with a relationship Gapoji.

  In the latent image printed material according to the present invention, the first image further includes a camouflage portion, and the camouflage portion includes a plurality of camouflage elements, and the plurality of camouflage elements are obtained from an image obtained by negative-positive reversal of the second image. It is formed by removing the information part or by inverting the negative image of the second image, and the camouflage part is the same color as the second image under diffuse reflection so that it does not overlap the information element and the background element. It is formed with the area ratio which becomes.

  The latent image printed material according to the present invention is characterized in that the information element, the background element, and the camouflage element are at least one of an image line and a pixel, or a combination thereof.

  The latent image print according to the present invention is characterized in that the area ratio of the first image is formed in a range of 10% to 80%, and the difference between the minimum area ratio and the maximum area ratio is 50% or less. .

  The latent image printed material according to the invention is characterized in that the substrate is a substrate having permeability.

  In the latent image printed matter of the present invention, the first image can be viewed under normal observation conditions (under diffuse reflected light), and the second image can be viewed under regular reflected light and transmitted light. Therefore, it is possible to determine the authenticity by confirming the latent image under a plurality of different conditions using a single printed image. Also, imitating the effect of latent image appearance under multiple different conditions is naturally more difficult than imitating the technique of latent image appearance under a single condition. Excellent power.

  In the case of the latent image printed material of the present invention, the latent image printed material handed over from the customer is first slightly inclined and specularly reflected to check whether the second image can be visually recognized. Since this operation is an extremely small operation, it is not known from the customer side whether the authenticity determination is performed. If it is a genuine product, the second image can be visually recognized at this stage, so that no further check is necessary. However, in this state, the second image cannot be visually recognized or the image is unclear, and only when there is a suspicion, the act of seeing through the latent image printed material can be performed, and the authenticity determination can be made reliably. is there. As described above, with this latent image printed matter, each weak point of the authenticity determination method using specular reflection light and transmitted light can be supplemented with one element. Therefore, it is possible to make authenticity determination more natural and reliable, and it is possible to provide a situation in which counterfeit products can be easily eliminated as compared with the conventional case.

  The latent image printed matter formed by the above method is excellent in cost performance because it can be manufactured by offset printing which is a highly productive printing method.

The latent image printed matter in this invention is shown. The printing image contained in the latent image printed material in this invention is shown, (a) shows a 1st image and (b) shows a 2nd image. Each image part which comprises the 1st image in this invention is shown, (a) shows an information part, (b) shows a background part. The 1st image in this invention shows an example which has a camouflage part. The 1st image in this invention shows an example which has a camouflage part. The effect of the latent image printed material in the present invention is shown. (A) shows an image that is visually recognized when an observer views the latent image printed material under diffuse reflected light, and (b) is observed under regular reflected light. The image visually recognized when a person looks at a latent image printed matter is shown. (C) shows the image visually recognized when an observer looks at the latent image printed material under transmitted light. An example at the time of forming the 1st image in this invention with a pixel is shown. An example at the time of forming the 1st image in this invention by an image line is shown. Each of the elements represents at least one of an image line and a pixel or a combination thereof. The latent image printed matter in Example 1 is shown. The image contained in the latent image printed matter in Example 1 is shown, (a) shows a 1st image, (b) shows a 2nd image. Each image part which comprises the 1st image in Example 1 is shown, (a) shows an information part, (b) shows a background part. The specific structure of the 1st image in Example 1 is shown, (a) shows an information part, (b) shows a background part. The effect of the latent image printed matter in Example 1 is shown, (a) shows an image that is visually recognized when an observer views the latent image printed matter under diffuse reflected light, and (b) is under regular reflected light. The image visually recognized when an observer looks at latent image printed matter is shown. (C) shows the image visually recognized when an observer looks at the latent image printed material under transmitted light. The latent image printed matter in Example 2 is shown. The image contained in the latent image printed matter in Example 2 is shown, (a) shows a 1st image, (b) shows a 2nd image. Each image part which comprises the 1st image in Example 2 is shown, (a) shows an information part, (b) shows a background part, (c) shows a camouflage part. The concrete structure of the 1st image in Example 2 is shown, (a) shows an information part, (b) shows a background part, (c) shows a camouflage part. The effect of the latent image printed matter in Example 2 is shown, (a) shows an image that is visually recognized when an observer views the latent image printed matter under diffuse reflected light, and (b) is under regular reflected light. The image visually recognized when an observer looks at latent image printed matter is shown. (C) shows the image visually recognized when an observer looks at the latent image printed material under transmitted light. The latent image printed matter in Example 3 is shown. The image contained in the latent image printed matter in Example 3 is shown, (a) shows a 1st image, (b) shows a 2nd image. Each image part which comprises the 1st image in Example 3 is shown, (a) shows an information part, (b) shows a background part, (c) shows a camouflage part. The specific structure of the 1st image in Example 3 is shown, (a) shows an information part, (b) shows a background part, (c) shows a camouflage part. The effect of the latent image printed matter in Example 3 is shown, (a) shows an image that is visually recognized when an observer views the latent image printed matter under diffuse reflected light, and (b) is under regular reflected light. The image visually recognized when an observer looks at latent image printed matter is shown. (C) shows the image visually recognized when an observer looks at the latent image printed material under transmitted 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.

  FIG. 1 shows a latent image printed material (1) according to the present invention. In the latent image printed matter (1), a printed image (3) having a color different from that of the substrate is formed on at least a part of the substrate (2). For convenience of explanation, the “sakura” pattern is represented in the printed image (3). However, when observed under diffuse reflection, the “sakura” pattern is not visible.

  FIG. 2 shows the configuration of the print image (3). The print image (3) is composed of a first image (4) shown in FIG. 2 (a) and a second image (5) shown in FIG. 2 (b).

  FIG. 3 shows the configuration of the first image (4). The first image (4) is composed of an information part (6) shown in FIG. 3A and a background part (7) surrounding the information part (6) shown in FIG. 6) consists of meaningful information such as letters, numbers and symbols. In the description of the embodiment for carrying out the present invention, the information part (6) is assumed to be the characters “JAPAN”.

  The second image (5) is formed by solid printing with an area ratio of 100%, and consists only of meaningful information such as letters, numbers and symbols. In the description of the mode for carrying out the present invention, the second image (5) has a “sakura” pattern.

  However, as described above, it is most desirable to form the second image (5) by solid printing with an area ratio of 100%, but for the purpose of preventing printing troubles such as peeling (picking) and trapping failure, it is slightly. Designing with a reduced area ratio (for example, up to about 80%) is within the scope of the technical idea of the present invention. Further, for example, even when the second image (5) is printed on the substrate (2) at an area ratio of 95%, some dot gain is caused, and the second latent image printed matter (1) thus produced The area ratio of the image (5) is 100%. Even in this case, the second image (5) in the present invention is formed by solid printing.

  For example, even when the second image (5) printed at an area ratio of 75% has an area ratio of 80% due to dot gain, the second image (5) in the present invention is solid. It is said that it is formed by. From these facts, the area ratio in the second image (5) is a category of solid printing if the area ratio of the second image (5) exceeds 80% after the production of the latent image print (1). And However, in consideration of the effect of the present invention, it is preferable that the second image (5) is in a solid state with an area ratio of 100% after the production of the latent image print (1).

  Peeling is a phenomenon in which the paper surface is deformed or peeled off during printing, and is an obstacle to the paper surface layer that occurs during the process of ink transfer. Trapping failure is a result of preprinted ink being postprinted This is a phenomenon in which the post-printing ink does not transfer cleanly without accepting the ink. The dot gain is a phenomenon in which halftone dots are printed larger than the corresponding halftone dots of the plate because the ink on the plate is spread by the printing pressure.

  The information part (6) and the background part (7) forming the first image (4) have a difference in light and shade. In order to form this shade difference, the area ratios of the halftone dots of the information part (6) and the background part (7) are simply different. As a method of varying the area ratio, a method using the size of halftone dots or a method using the density of halftone dots is known, and in addition, a specific size as described in Examples 1, 2, and 3 described later. Alternatively, a method may be used in which a certain area ratio is formed by regularly arranging a plurality of pixels or image lines having a specific width. The area ratio in the present invention is the ratio of the printed area in a certain area.

  The first image (4) is formed with ink containing a glittering material. As a result, the first image (4) formed with a certain gradation restriction changes lightly by strongly reflecting the light under the specular reflection light, and the information portion (6) and the background portion (7). The gradation difference converges. Therefore, the light / dark difference between the information part (6) and the background part (7) visually recognized under diffuse reflected light disappears under regular reflected light, and the first image (4) is visually recognized as a flat image. Effect is produced.

  The 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 using general pearl pigments such as iris pearl pigments and scaly pigments, and functional pigments such as glass flake pigments and cholesteric liquid crystal pigments, a light / dark flip-flop that changes only the brightness of the first image. Color flip-flop property that changes not only the color property but also the color tone of the first image can be provided.

  The second ink forming the second image (5) has a penetrating component that increases the transmittance of the printed area of the second ink by penetrating into the printed paper like watermark ink. (Hereinafter referred to as “penetration type ink”). This is a characteristic necessary for observing the second image (5) under transmitted light. These penetrating inks are colorless and transparent. In this specification, colorless and transparent means that the ink does not contain any colored pigments or dyes other than white, and the ink varnish itself has a slight color (most penetrating inks are varnished). However, it is colorless and transparent. Further, in order to control the viscosity and printability of the ink, the case where a white pigment or a translucent pigment is blended is also included as colorless and transparent.

  In addition, penetrating ink is used as the second ink, but penetrating ink is slightly visible when the ink after printing penetrates into the substrate even if the ink itself is colorless and transparent. In many cases, the color density is as high as possible. In this case, under diffuse reflected light, the second image (5) that should be invisible may be visualized, and the first image (4) may be visible at the same time. In such a case, this problem can be avoided by adding a camouflage portion to the first image (4). The configuration of the camouflage unit will be described with reference to FIGS. 4 and 5.

  As shown in FIG. 4, the print image (3) includes a first image (4) and a second image (5). Of these, the first image (4) comprises an information part (6), a background part (7) and a camouflage part (12). The information part (6) forms the characters “JAPAN” which is meaningful information, and the background part (7) is adjacent to surround the information part (6). The camouflage part (12) is formed by arranging a plurality of camouflage elements, and the camouflage part (12) is obtained from an image obtained by inverting the negative pattern of the “cherry blossom” pattern as the second image (5). ) Is removed. This specific method will be described in Example 2 described later.

  As shown in FIG. 5, the print image (3) includes a first image (4) and a second image (5). Of these, the first image (4) comprises an information part (6), a background part (7) and a camouflage part (12). The information part (6) forms the characters “JAPAN” which is meaningful information, and the background part (7) is adjacent to surround the information part (6). The camouflage portion (12) is formed by arranging a plurality of camouflage elements, and the camouflage portion (12) is an image obtained by negatively and positively reversing the “sakura” pattern as the second image. This specific method will be described in Example 3 to be described later.

  In addition, when a colorless and transparent ink is used for the second ink, the purpose is to determine whether or not a fatal defect such as reprinting or printing failure has occurred, or for the purpose of improving authenticity discrimination. There is no problem even if a light emitting pigment such as a fluorescent pigment, a fluorescent dye and a phosphorescent pigment or a functional material such as an infrared absorbing material and an infrared transmitting material is added to the ink. For the purpose of improving authenticity discrimination, it can be said that it is more effective to add these functional materials to the first ink as well as the second ink.

  In addition, when the second image (5) is printed with the second ink, and the ink penetrates and the second image (5) is visualized, even a slight color density is generated in the second image (5). Only in some cases, the first ink and the second ink need to have the same hue under diffuse light. In the case where even a slight color density occurs in the printed image (3) when the second ink is printed, in order to make the second image (5) invisible under diffuse reflected light, the above-mentioned camouflage portion ( 12) is formed with the first ink and the second image (5) is concealed. If the hues of the first ink and the second ink are different, the second image This is because (5) cannot be concealed visually.

  The reason why it is desirable to form the second image (5) at an area ratio of 100% is that the transfer amount of the penetrating ink is increased as much as possible to increase the transparency, and the second image (5) can be visually recognized under transmitted light. This is to improve the visibility of the image (5) and to maintain high authenticity discrimination. In addition, in order to obtain another effect of the present invention that allows the second image (5) to be visually recognized under specular reflection light, the reflectance in a printed portion and a non-printed portion is required. Therefore, it is desirable to form the second image (5) with an area ratio of 100% in order to keep the difference in reflectance.

  The production procedure of the latent image printed material (1) of the present invention will be described. First, the second image (5) is printed on the substrate (2) using the second ink, and then the first image (4) is printed using the first ink. At this time, after printing the second image (5) with the second ink, it is preferable to print the first image (4) with the first ink before the second ink is dried. This is because when the first image (4) is printed in a state where the second ink is completely dry, a portion where the first image (4) is printed over the second image (5), This is because the difference in reflectance from the portion where the first image (4) is printed on the substrate is halved, so that the effect of the present invention is reduced.

  Since the second ink is a penetrating ink, a certain amount of time is required until the penetrating ink, and the second image (5) among the first images (4) is printed by the above-described procedure. The area printed on top of the first ink is formed by overlapping the first ink in a state before penetrating and leveling the second ink and reaching the set.

  Leveling is the property or state that the ink surface becomes smooth after printing. The ink stretches in a streak shape at the stage of transition and then splits, and it contracts and forms an ink film while flowing laterally. This ink coating flows until the viscosity increases in the subsequent drying process. During this time, the printed image is wet.

  In printing, the difference in the partial wettability of the substrate to be printed has a great influence on the transfer of printed ink and the quality of printed matter. In particular, the ink printed by post-printing is an ink containing a glittering material. In some cases, the pigment orientation of the glittering material after the transition is particularly affected greatly. The difference in pigment orientation causes the intensity of reflection in a printed image under specular reflection light. Therefore, the intended image can be made to appear by the intensity of the light under the regular reflection light by adjusting the state of the base during the post-printing printing.

  The thicker the film is, the lower the level of the underlying layer, the more the glittering material that is formed and the orientation after the transition are disturbed, and the amount of reflected light under specular light becomes smaller compared to the part without the underlying printing. For this reason, the contrast of light with the area where the background printing is present increases.

  Therefore, in order for the observer to view the second image (5) under the specularly reflected light, the second image (5) printed at the time when the first image (4) is printed. It is preferable that the ink does not penetrate into the base material (2) and remains on the surface of the base material (2), and the second image (5) is obtained by using the second ink on the base material (2). After printing, it is preferable to print the first image (4) by using the first ink before the second ink penetrates the substrate (2).

  However, if the film thickness of the preprinted ink is too thick, the amount of ink transfer itself changes between the area with the background printing and the area without the background printing, and is not included in the first image (4). Necessary shading and unevenness occur. In order to suppress the occurrence of shading and unevenness caused by the difference in the state of the preprinted ink, the amount of ink transferred on the surface is not changed so that only the pigment orientation of the glittering material is changed. It is necessary to adjust the surface of the ink film that does not lead to permeation and leveling to a rough state and perform post-printing.

  The range of the proper state of the transferred ink depends greatly on the constituent materials, flow characteristics, printing method, etc. of the first ink and the second ink. It is necessary to adjust from time to time.

  As described above, by forming the first image (4) with the first ink containing the glittering material on the second image (5) maintaining an appropriate ink state, A latent image print (1) can be obtained. The effects of the invention will be described below with reference to FIG.

  As shown in FIG. 6A, in the observation under diffuse reflected light in the positional relationship such as the latent image printed matter (1), the light source (10), and the observer (11a), Only the image (4) is visually recognized. This is because the second ink is colorless and transparent, is almost invisible, and the first image (4) is directly superimposed on the substrate and the region superimposed on the second ink. Since the state of the previously transferred ink is adjusted so that the amount of ink transferred is substantially equal between the first and second areas, unnecessary shading does not occur in the first image (4). is there.

  In the present invention, “under diffuse reflection” refers to the angle of light incident on the latent image printed matter (1) from the light source (10) and the light reflected from the latent image printed matter (1) other than the region under regular reflected light. Is an area where the specularly reflected light is substantially different, and “observation under diffusely reflected light” in the present invention is an area where the observer (11a) has almost no specularly reflected light. It shows the situation in which the latent image printed matter (1) is observed.

  In addition, as shown in FIG. 6B, in the observation under the specular reflection light such as the latent image printed matter (1), the light source (10), and the observer (11b), the observer is given the first Only the second image (5) is visible in a positive state. This is because the first image (4) changes lightly by strongly reflecting light, and the gradation difference between the information part (6) and the background part (7) converges, and the first image (4) The pigment orientation of the glittering material of the first image (4) overlaid on the second image (5) depending on the presence or absence of the second ink in the state of the transferred ink. This is because the intensity of the reflected light under regular reflection light changes and the second image (5) is viewed dark.

  Note that, when observing under specular reflection light, the second image (5) is printed in a solid state or in a state close to a solid state, so that the second image (5) in the non-image area where the glittering material is not printed. The difference in glossiness and texture compared with the part where the second image (5) is printed and the base part where the second image is not printed is a synergistic effect, and the second image (5) appears under specular reflection. Needless to say, it contributes to improving the visibility of the effect.

  “Under specular reflection” in the present invention means that the angle of light incident on the latent image printed matter (1) from the light source (10) is substantially equal to the angle of light reflected from the latent image printed matter (1). When light is incident on the latent image printed material (1) from the light source (10) at an incident angle of −45 °, it is a region where strong reflected light is generated in the region near the light receiving angle of 45 °. “Observation under reflected light” indicates a situation in which the viewpoint of the observer (11b) is in the region where the above-described regular reflection light is generated and the latent image print (1) is observed.

  In addition, as shown in FIG. 6C, in observation under transmitted light, incident light reaches the observer (11c) after passing through the base material (2). The amount of light reaching the observer is reduced compared to the observation, and it is difficult for the observer (11c) to visually recognize the light / dark difference between the information part (6) and the background part (7) of the first image (4). . On the contrary, the second image (5) is formed with the second ink, which is a penetrating ink, and has a high light transmittance. Therefore, under the transmitted light, the second image (5) transmits light to an unprinted area. Visible in a negative state due to the difference in rate. Therefore, in the observation under transmitted light, when the latent image print (1) is observed, the second image (5) is visually recognized in a negative state with high contrast. When observed under transmitted light, the second image (5) is mainly visually recognized, but at the same time, the first image (4) is also slightly overlapped and visually recognized.

  Thus, in the form for carrying out the present invention, as the second image (5), the pattern of “sakura” is used, and the second image (5) when observed under specular reflection light. Only the second image (5) is viewed in the negative state when only the second image (5) is viewed in the positive state when viewed only in the positive state. However, as the second image (5), when the pattern of “cherry blossoms” is cut out, the negative and positive images in the image observed under specular reflection and the image observed under transmitted light are shown. The relationship is reversed. That is, when observed under specularly reflected light, only the second image (5) is visible in a negative state, and when observed under transmitted light, the second image (5) is visible in a positive state. Is done. Such a state is said that the second image (5) is visually recognized with a negative-positive relationship.

  “Under transmitted light” in the present invention refers to a state in which the light source (10) is observed from the back side while being transmitted through the surface of the latent image print (1). Shows the situation where the viewpoint of the observer (11c) is in the above-described region under transmitted light and observes the latent image print (1).

  As described above, the latent image printed material (1) of the present invention has a so-called image change effect in which different images are visually recognized by observation under diffuse reflection light and observation under other conditions. Because this change effect can be confirmed under specular reflection light and transmitted light under a plurality of specific conditions, the effect of expanding the authentication environment that can determine authenticity compared to conventional technology Got. Further, the direction for confirming the latent image printed material (1) is not particularly limited, and as long as specular reflection light is generated by receiving incident light in the environment, the direction as described above can be observed from either direction. Similar effects can be obtained.

  In the latent image printed material (1) of the present invention, the difference between the minimum area ratio and the maximum area ratio in the first image (4) needs to be designed within 50%. When this difference exceeds 50%, the image viewed under the specularly reflected light and the transmitted light becomes an image where the second image (5) and the first image (4) are simultaneously viewed, and the latent image is latent. This is not desirable because the authenticity of the printed image (1) is impaired.

  In addition, when emphasizing the disappearance effect of the first image (4) under specular reflection light, the area ratio is a high area ratio near the shadow (for example, the minimum area ratio is 50% and the maximum area ratio is 100). However, if the loss effect of the first image (4) under transmitted light is emphasized, the area ratio close to the highlight is low (for example, the minimum area ratio is 10%). And the maximum area ratio is 60%).

  Therefore, in order to satisfy the two conflicting characteristics, the first image (4) of the present invention is preferably formed with a halftone dot centered dot excluding extreme highlights and extreme shadows. . From the above, the specific range of the area ratio for forming the first image (4) of the present invention is the range of the area ratio of 10% to 80%. An excessively small area ratio of less than 10% makes it difficult to obtain a stable print quality, and if it exceeds 80%, the visual effect of the second image (5) under transmitted light is lost. is there. The design is made so that the difference between the minimum area ratio and the maximum area ratio is within 50% within this range.

  As described above, the method of adding light and shade to the first image is not limited to the method of simply changing the area ratio of the information part (6) and the background part (7). The area ratio of the information part (6) and the background part (7) may be arbitrarily formed by arranging them regularly.

  FIG. 7 shows an example in which the information portion (6) and the background portion (7) of the first image (4) are formed by pixels, and the area ratio is varied depending on the size of the pixels. As shown in FIG. 7A, information elements (8), which are pixels having a height (H1) and a width (R1), are regularly arranged at a pitch (P1) in a specific direction, and an information section (6 7), and background elements (9), which are pixels of height (H2) and width (R2), are regularly arranged at a pitch (P2) in a specific direction as shown in FIG. 7B. A part (7) can be formed.

  In this case, the pixel height (H1) of the information element (8) is higher than the pixel height (H2) of the background element (9), and the pixel width (R1) of the information element (8) is Since it is formed wider than the pixel width (R2) of the background element (9), the area ratio of the information element (8) is formed larger than the area ratio of the background element (9).

  FIG. 8 shows an example in which the information part (6) and the background part (7) of the first image (4) are formed by drawing lines, and the area ratio is varied depending on the width of the drawing line. As shown in FIG. 8A, the information element (8), which is an image line having a width (W1), is regularly arranged at a pitch (P1) in a specific direction to form an information part (6). As shown in FIG. 8 (b), the background element (9), which is an image line of width (W2), is regularly arranged at a pitch (P2) in a specific direction to form a background portion (7). Can do.

  In this case, since the line width (W1) of the information element (8) is formed wider than the line width (W2) of the background element (9), the area ratio of the information element (8) It is formed larger than the area ratio of the element (9).

  The information element (8), the background element (9), and the camouflage element (13) are formed by at least one of an image line and a pixel, or a combination thereof. That is, as shown in FIG. 9A, the information element (8) and the background element (9) are formed by pixels, and the camouflage element (13) is formed by a line, etc. Pixels may be combined. Further, as shown in FIG. 9B, in the information element (8), the background element (9), and the camouflage element (13), a line and a pixel may be combined with each other. Further, as shown in FIG. 9C, in the information element (8), the background element (9), and the camouflage element (13), the image line and the pixel may be combined in each element.

  The “image line” in the present invention is an image element formed by continuously arranging halftone dots, which are the minimum unit of a printed matter, without a gap in a certain direction, and is a broken line, a broken line, a straight line, or a curved line. In addition, any line shape is included in the technical idea of the present invention. Similarly, a “pixel” is a group of image elements formed by collecting a plurality of halftone dots, and the shape may be a circle, polygon, star, etc., and other special characters and symbols etc. It is.

  The printing method of the latent image printed material in the present invention is not particularly limited, such as offset printing, flexographic printing, letterpress printing, gravure printing, screen printing, intaglio printing, and can be formed by various printing methods. In addition, if the penetrating ink and the ink containing the glittering material can be used, it can be formed by IJP or the like. In this case, the information on the output product for each sheet is changed. So-called variable printing can be performed.

  Moreover, it is desirable to use a paper having permeability such as a coated paper or a high-quality paper as a base material used for the latent image printed matter in the present invention. Ink does not penetrate at all, or a metal or plastic with extremely low permeability cannot provide a sufficient effect.

  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. White fine paper (manufactured by Nippon Paper Industries Co., Ltd.) was used as the substrate.

  FIG. 10 shows a latent image print (1 ′) according to the present invention. In the latent image printed matter (1 ′), a gray printed image (3 ′) is formed on a part of the substrate (2 ′), and the printed image (3 ′) is the first image shown in FIG. Image (4 ′) and the second image (5 ′) shown in FIG. 11B. Among these, the first image (4 ′) is composed of an information part (6 ′) and a background part (7 ′) as shown in FIGS. 12 (a) and 12 (b). The information part (6 ′) forms characters “JAPAN” which is meaningful information, and the background part (7 ′) is adjacent to surround the information part (6 ′).

  FIG. 13 shows a specific configuration of the information part (6 ′) and the background part (7 ′) of the first image (4 ′). FIG. 13A shows an information part (6 ′) and an enlarged view of a part thereof. The information part (6 ′) is composed of a plurality of information elements (8 ′). Specifically, the information elements (8 ′), which are circular pixels having a diameter of 0.36 mm, are regularly arranged at a pitch of 0.45 mm so as not to overlap each other.

  FIG.13 (b) shows a background part (7 ') and the one part enlarged view. The background portion (7 ′) is formed by regularly arranging circular background elements (9 ′) having a diameter of 0.20 mm with a pitch of 0.45 mm.

  The area ratio of the information part (6 ′) is about 51%, and the area ratio of the background part (7 ′) is about 16%. Therefore, the maximum area ratio in the first image is 51% and the minimum area ratio is 16%, and the difference in the area ratio is 35%.

  The production procedure of the latent image printed matter (1 ′) in the first embodiment will be described. First, the second image (5 ′) shown in FIG. 11B is printed by an offset printing method using a penetrating set type transmissive ink (T & K TOKA's best one watermark ink) as the second ink. did. Immediately after that, the first image (4 ′) shown in FIG. 11A is offset by UV drying using silver ink containing aluminum powder as the first ink (UV NO3 silver manufactured by T & K TOKA). The latent image print (1 ′) in Example 1 was formed by superimposing by printing.

  When the second ink is printed on high-quality paper at an area ratio of 100%, if about 6 to 12 hours have not passed, the non-penetrated ink remains on the paper surface, and the printed surface remains wet. However, the surface condition of this ink will permeate and set over time, and the effect on the orientation of the glittering pigment in postprinting will be reduced, so the first image is superimposed immediately after the second image is printed. Is desirable.

  The effect of the latent image printed material (1 ′) formed by the above procedure was confirmed. First, as shown in FIG. 14A, in the observation under diffuse reflected light, which is in a positional relationship such as the latent image printed matter (1 ′), the light source (10 ′), and the observer (11a ′), Only the characters “JAPAN”, which is one image (4 ′), and its background were visually recognized.

  Further, as shown in FIG. 14B, in the observation under specular reflection light, which is in a positional relationship such as the latent image printed matter (1 ′), the light source (10 ′), and the observer (11b ′), Only the pattern of “sakura” as the second image (5 ′) was visually recognized in a positive state.

  Further, as shown in FIG. 14C, light is incident on the latent image printed matter (1 ′) from the surface opposite to the observer (11c ′), and the light transmitted through the latent image printed matter (1 ′) is observed. When the latent image printed matter (1 ′) was observed in a state visually recognized by the person (11c ′), the pattern of “sakura” as the second image (5 ′) was visually recognized in a negative state.

  As described above, the latent image printed matter (1 ′) in the first embodiment has a so-called image change effect in which different images are visually recognized by observation under diffuse reflection light and observation under other conditions. I was able to confirm that I have it.

  A second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, when the second image has a slight color density and does not become invisible under diffuse reflected light, a camouflage portion having a negative / positive reversal relationship with the second image is included in the first image. In this example, the second image is not visually recognized by the viewer. As the base material, white fine paper (manufactured by Nippon Paper Industries Co., Ltd.) was used as in Example 1.

  FIG. 15 shows a latent image print (1 ″) according to the present invention. In the latent image printed matter (1 ″), a gray printed image (3 ″) is formed on a part of the base material (2 ″), and the printed image (3 ″) is shown in FIG. The first image (4 ″) shown in FIG. 16 and the second image (5 ″) shown in FIG. Among these, the first image (4 ″) includes the information portion (6 ″) shown in FIG. 17A, the background portion (7 ″) shown in FIG. 17B, and FIG. The camouflage part (12 '') shown in FIG. The information part (6 ″) forms characters “JAPAN” which is meaningful information, and the background part (7 ″) is adjacent to surround the information part (6 ″). In addition, the camouflage part (12 ″) in Example 2 is an image obtained by removing the information part (6 ″) from the image obtained by inverting the negative pattern of the “sakura” pattern as the second image (5 ″). It is.

  FIG. 18 shows a specific configuration of the information part (6 ″), the background part (7 ″), and the camouflage part (12 ″) of the first image (4 ″).

  FIG. 18A shows an information section (6 ″) and an enlarged view of a part thereof. The information part (6 ″) is composed of a plurality of information elements (8 ″). Specifically, the information elements (8 ″), which are circular pixels having a diameter of 0.36 mm, are regularly arranged at a pitch of 0.45 mm so as not to overlap each other.

  FIG. 18B shows a background portion (7 ″) and a partial enlarged view thereof. The background portion (7 ″) is formed by regularly arranging background elements (9 ″) that are circular pixels having a diameter of 0.20 mm with a pitch of 0.45 mm.

  FIG. 18C shows a camouflage portion (12 ″) and an enlarged view of a part thereof. The camouflage portion (12 ″) is formed by regularly arranging camouflage elements (13 ″), which are circular pixels having a diameter of 0.16 mm, with a pitch of 0.45 mm.

  Further, the information element (8 ″), the background element (9 ″), and the camouflage element (13 ″) constituting each of them are arranged without overlapping each other. The area ratio of the information section (6 ″) is about 51%, the area ratio of the background section (7 ″) is about 16%, and the area ratio of the camouflage section (12 ″) is about 13%. Therefore, the maximum area ratio in the first image (4 ″) is 51%, the minimum area ratio is 29% (16% + 13%), and the difference in the area ratio is 22%.

  The camouflage portion (12 ″) is configured to form a pair with the second image (5 ″), and the second image (5 ″) that is slightly visible is used as the background portion (7 ″). ) It is concealed inside and has the effect of making it invisible. In order to obtain an appropriate effect for making the second image (5 ′) invisible, the area ratio of the camouflage portion (12 ″) is set so as to have the same density as the second image (5 ″). It needs to be adjusted.

  The second ink used in Example 2 (Unimark made by Teikoku Ink) is an ink that is colorless and transparent, but when printed on a base material, it penetrates into the base material and adjusts the color density of the base material. Because of the slight increase, the printed image is slightly darker than the color of the substrate (eg, if the substrate is white, the printed image is light gray).

  For this reason, in Example 2, the color density when the second ink is printed at 100% in advance is substantially the same color as the color density when the first ink is printed at an area ratio of 10 to 15%. The area ratio of the camouflage part (12 ″) is designed to be 13%. Thereby, the second image (5 ″) slightly visualized becomes invisible again when the first image (4 ″) having the camouflage portion (12 ″) is overlaid.

  The area ratio of the camouflage portion (12 ″) is determined according to the color density of the second image (5 ″) and the color density of the first ink. It is necessary to find an appropriate value.

  In the second embodiment, the camouflage portion (12 ″) is formed only in the region overlapping the background portion (7 ″). However, in addition to the background portion (7 ″), the information portion (6 ″) ) May also be formed in the overlapping area. In Example 2, the camouflage part (12 ″) was not provided in the area overlapping with the information part (7 ″). The information part (7 ″) was compared with the background part (6 ″). Since the area ratio is high and the density is much darker than that of the second image (5 ″), the color density increased by the second image (5 ″) is substantially concealed visually. It is because it ends up.

  An example in which the camouflage portion (12 ″) is formed in a region overlapping with the information portion (7 ″) will be described in a third embodiment. However, in any case, when the second image (5 ″) is visualized, the area ratio of the background portion (7 ″) is low, so the second image (5 ″) ), It is difficult to conceal even a slight color density, so that it is necessary to provide a camouflage portion (12 ″).

  A procedure for producing the latent image printed matter (1 ″) in the second embodiment will be described. The second image (5 ″) shown in FIG. 16B was printed by an offset printing method using a transmissive ink containing a penetrating component (Teikoku Unimark) as the second ink. Immediately thereafter, the first image (4 ″) shown in FIG. 16A is offset by UV drying using silver ink (T & K Silver TKSO) containing aluminum powder as the first ink. The latent image printed material (1 ″) in Example 2 was formed by superimposing.

  The effect of the latent image printed material (1 ″) formed by the above procedure was confirmed. First, as shown in FIG. 19 (a), in observation under diffuse reflected light in a positional relationship such as a latent image printed matter (1 ″), a light source (10 ″), and an observer (11a ″). Only the characters “JAPAN” as the first image (4 ″) and the background portion thereof were visually recognized.

  Further, as shown in FIG. 19B, in the observation under specular reflection light in the positional relationship such as the latent image printed matter (1 ″), the light source (10 ″), and the observer (11b ″). Only the “sakura” pattern of the second image (5 ″) was visually recognized in a positive state.

  Further, as shown in FIG. 19C, light (10 ″) is incident on the latent image printed matter (1 ″) from the surface opposite to the observer (11c ″), and the latent image printed matter (1 ′) When the latent image printed matter (1 ″) is observed in a state where the observer (11c ″) visually recognizes the light (10 ″) transmitted through ′), the second image (5 ″) A certain “sakura” pattern was seen in a negative state.

  As described above, the latent image printed matter (1 ″) according to the second embodiment is a so-called image change effect in which different images are visually recognized by observation under diffuse reflection light and observation under other conditions. It was confirmed that the In addition, a camouflage portion (12 ″) designed with an appropriate area ratio is provided in the second image (5 ″) formed with the second ink, even if a density increase that can be visually observed occurs. Thus, it was confirmed that the second image (5 ″) can be made invisible under diffuse reflection light.

  A third embodiment of the present invention will be described with reference to FIGS. As in the second embodiment, the third embodiment is an example in which a camouflage portion is provided in the first image and the first image is configured with an image line. As the base material, white fine paper (manufactured by Nippon Paper Industries Co., Ltd.) was used as in Example 1.

  FIG. 20 shows a latent image print (1 ′ ″) according to the present invention. In the latent image printed matter (1 ″ ″), a gray printed image (3 ″ ″) is formed on a part of the substrate (2 ″ ″), and the printed image (3 ″ ″) The first image (4 "') shown in Fig. 21 (a) and the second image (5"') shown in Fig. 21 (b) are included. Among these, the first image (4 ′ ″) includes an information part (6 ′ ″) shown in FIG. 22A, a background part (7 ″ ′) shown in FIG. 22B, and FIG. It consists of the camouflage part (12 '' ') shown in c). The information part (6 ′ ″) forms the characters “JAPAN” which is meaningful information, and the background part (7 ′ ″) is adjacent to surround the information part (6 ′ ″). Become. Further, the camouflage portion (12 ′ ″) is an image obtained by inverting the “sakura” pattern, which is the second image (5 ′ ″), in a negative / positive manner.

  FIG. 23 shows a specific configuration of the information part (6 ′ ″), the background part (7 ′ ″), and the camouflage part (12 ′ ″) of the first image (4 ″ ′).

  FIG. 23A shows an information part (6 ′ ″) and an enlarged view of a part thereof. The information section (6 ′ ″) is formed by regularly arranging information elements (8 ′ ″) of an image line having an image line width of 0.60 mm at a pitch of 1.0 mm.

  FIG. 23B shows a background portion (7 ′ ″) and an enlarged view of a part thereof. The background portion (7 ′ ″) is formed by regularly arranging background elements (9 ′ ″) of an image line having an image line width of 0.20 mm at a pitch of 1.0 mm.

  FIG. 23C shows a camouflage portion (12 ″ ′) and an enlarged view of a part thereof. The camouflage portion (12 ″ ″) is formed by regularly arranging camouflage elements (13 ″ ″) having an image line width of 0.10 mm at a pitch of 1.0 mm.

  In addition, the information element (8 ′ ″), the background element (9 ′ ″), and the camouflage element (13 ′ ″) constituting each of them are arranged without overlapping each other. The area ratio of the information part (6 '' ') is about 60%, the area ratio of the background part (7' '') is about 20%, and the area ratio of the camouflage part (12 '' ') is about 10%. is there. Therefore, the maximum area ratio in the first image is 70% (60% + 10%), the minimum area ratio is 20%, and the difference in the area ratio is 50%.

  In the third embodiment, the camouflage portion (12 ″ ″) is also formed in a region overlapping with the information portion (6 ″ ″) and the background portion (7 ″ ″). In this case, the image line constituting the information part (6 ′ ″) and the image line constituting the background part (7 ′ ″) and the image line constituting the camouflage part (12 ′ ″) do not overlap each other. It is necessary to configure as follows. This is because, in the case of the overlapping configuration, unnecessary shading occurs, and the first image (4 ′ ″) becomes unclear.

  A procedure for producing the latent image printed matter (1 ″ ″) in the third embodiment will be described. The second image (5 ′ ″) shown in FIG. 21 (b) was printed by an offset printing method using a transmissive ink containing a penetrating component (Teikoku Unimark) as the second ink. Immediately after that, the first image (4 ′ ″) shown in FIG. 21A is offset printing by UV drying method using silver ink (T & K Silver TKSO) containing aluminum powder as the first ink. And the latent image printed matter (1 ″ ″) in Example 3 was formed.

  The effect of the latent image printed material (1 ′ ″) formed by the above procedure was confirmed. First, as shown in FIG. 24 (a), under the diffuse reflected light in the positional relationship such as the latent image printed matter (1 '' ''), the light source (10 '' '') and the observer (11a ''). In the observation, only the characters “JAPAN” as the first image (4 ′ ″) and the background portion thereof were visually recognized.

  As shown in FIG. 24 (b), observation under specular reflection light in a positional relationship such as a latent image printed matter (1 ""), a light source (10 "") and an observer (11b "). In FIG. 5, only the pattern of “sakura” as the second image (5 ′ ″) was visually recognized in a positive state.

  As shown in FIG. 24 (c), light is incident on the latent image printed matter (1 '') from the surface opposite to the observer (11c ''), and is transmitted through the latent image printed matter (1 ''). In the state where the viewer (11c '') visually recognizes the light, the pattern of "cherry blossom" that is the second image (5 "') when the latent image printed matter (1"') is observed Was seen in a negative state.

  As described above, the latent image printed matter (1 ″ ″) in the third embodiment is a so-called image change in which different images are visually recognized by observation under diffuse reflection light and observation under other conditions. It was confirmed that it had an effect. In addition, even in the second image (5 ′ ″) formed with the second ink, even when a density increase that can be visually observed occurs, the camouflage portion (12 ″ ″) designed with an appropriate area ratio. It was possible to confirm that the second image (5 ′ ″) can be made invisible under diffuse reflection light.

1, 1 ′, 1 ″, 1 ″ ″ Latent image printed matter 2, 2 ′, 2 ″, 2 ″ ″ base material 3, 3 ′, 3 ″, 3 ″ ″ printed image 4, 4 ′ 4 ″, 4 ″ ″ First image 5, 5 ′, 5 ″, 5 ″ ″ Second image 6, 6 ′, 6 ″, 6 ″ ″ Information section 7, 7 ′, 7 ″, 7 ″ ″ Background part 8, 8 ′, 8 ″, 8 ″ ″ Information element 9, 9 ′ 9 ″, 9 ″ ″ Background element 10, 10 ′ 10 ″, 10 ″ ′ Light 11a, 11b, 11c, 11a ′, 11b ′, 11c ′, 11a ″, 11b ″, 11c ″, 11a ″, 11b ″, 11c ″ ″ Observer 12, 12 ″ , 12 "" camouflage part 13, 13 ", 13""camouflage element

Claims (5)

A printed image having a color different from that of the substrate is formed on at least a part of the substrate, and the printed image includes a first image and a second image,
The second image is formed by solid printing with a colorless and transparent penetrating second ink,
On the second image, the first image is formed with a first ink containing a glittering material, and the first image includes an information portion in which a plurality of information elements are regularly arranged; It is divided into a background portion formed by regularly arranging a plurality of background elements at an area ratio different from that of the information portion, and the information element and the background element are formed so as not to overlap,
When observed under diffusely reflected light, only the first image is visually recognized.When observed under specularly reflected light, only the second image is visually observed.When observed under transmitted light, A latent image printed matter characterized by being viewed in a negative-positive relationship with the second image viewed under specular reflection light. The first image further includes a camouflage portion,
In the camouflage section, a plurality of camouflage elements are arranged,
The plurality of camouflage elements are formed by removing the information part from an image obtained by negatively inverting the second image, or formed by inverting the second image negatively positively. The latent image printed matter according to claim 1, wherein the camouflage portion is formed with an area ratio that is the same color as that of the second image under diffuse reflected light so as not to overlap with an element.   The latent image printed matter according to claim 1, wherein the information element, the background element, and the camouflage element are at least one of an image line and a pixel, or a combination thereof.   4. The area ratio of the first image is formed in a range of 10% to 80%, and a difference between the minimum area ratio and the maximum area ratio is 50% or less. 2. The latent image printed matter according to item 1.   The latent image printed matter according to claim 1, wherein the substrate is a substrate having permeability.

Images