JP5190623B2 - Printed material having latent image - Google Patents

Description

  The present invention relates to a printed matter having a latent image that is applied to banknotes, passports, securities, product tags, various certificates and the like for prevention of counterfeiting and duplication.

  In recent years, counterfeit printed products such as banknotes, passports, and securities have become a serious problem due to high performance and high image quality of copiers. For this reason, functional inks that are difficult to reproduce color, gloss, light emission or the like with a copying machine have been conventionally used for precious printed matter. Functional inks include gold ink, silver ink or pearl ink, which is difficult to reproduce color or gloss in a copying machine, and infrared absorbing ink exhibiting absorption characteristics in the infrared region.

When authenticating a printed matter using infrared absorbing ink, an identification device such as an infrared camera is required. Therefore, it is difficult to visually determine the infrared absorbing ink printing portion without an identification device. On the other hand, when authenticating printed matter using metallic gloss ink, it is only necessary to pay attention to changes in gloss and color, and anyone can easily determine visually. For this reason, many valuable prints are used in combination with a plurality of functional inks having different ink characteristics.

  For example, in Patent Document 1 filed earlier by the present applicant, cyan (C), which is used in general commercial printing, in the case where two different images are equally arranged as a halftone dot image on the same plane, There is disclosed a halftone printed matter in which a visible image and a latent image are generated using basic inks of magenta (M), yellow (Y), and black (Bk). Cyan (C), magenta (M) and yellow (Y) used in general commercial printing do not absorb infrared rays. Therefore, mixed color black in which cyan (C), magenta (M), and yellow (Y) are superposed does not absorb infrared rays. On the other hand, black (Bk) is mainly composed of carbon black and exhibits absorption over the entire region from the ultraviolet region to the infrared region. Using the above action, a halftone print printed based on a predetermined arrangement rule using cyan (C), magenta (M), yellow (Y), black (Bk) and mixed color black is visible under a visible light source. A latent image that can be observed using an identification device such as an infrared camera can be embedded in the visible image. Since the halftone dot printed material does not require the use of special ink, it can be produced at low cost and cannot be duplicated with a current photoengraving apparatus, and therefore has an excellent anti-counterfeit effect.

  Patent Document 2 discloses counterfeiting using a combination of basic inks of cyan (C), magenta (M), yellow (Y), and black (Bk), which are used in general commercial printing, and a metallic gloss ink. A printed matter for prevention is disclosed. For example, in a printed matter for preventing forgery, a diffused light visually recognized image is formed by a first region, a second region, and a third region. The first area is printed with metallic luster ink, the second area is printed with cyan (C), magenta (M) and / or yellow (Y) which are infrared transmissive inks, and the third area is It is printed with black (Bk) which is an infrared absorbing ink. When the printed material for forgery prevention is observed in the diffused light region under the visible light source, the diffused light visual image composed of the first region, the second region, and the third region is visually recognized. When observed, the first area printed with the metallic gloss ink can be confirmed as a glossy image. Furthermore, in the case where observation is performed using an identification device such as an infrared camera, the third region can be visually recognized as a latent image.

  Further, Patent Document 3 uses a halftone dot configuration disclosed in Patent Document 1 and cyan (C), magenta (M), yellow (Y), black (Bk), and metallic gloss inks, so that visible and latent images can be obtained. An anti-counterfeit printed matter in which an image is generated is disclosed. In the halftone dot configuration disclosed in Patent Document 1, a latent image that is visible only using an appraisal device such as an infrared camera is obtained by taking advantage of the property of absorbing black (Bk) from the ultraviolet region to the infrared region. Was forming. However, black (Bk) has a low brightness (high density) color, and thus has a great influence on the design of the printed design. That is, when the printed image is observed with an infrared camera or the like, if the latent image formed with black (Bk) is clarified, the maximum area ratio of the halftone dots used for black (Bk) inevitably increases. The visible image composed of cyan (C), magenta (M), and yellow (Y), which is observed with the naked eye, has a problem that the entire image becomes dark.

  Therefore, in Patent Document 3, a latent image formed with black (Bk) is formed using metallic gloss ink. The metallic gloss ink printing part and the black (Bk) printing part measured the density when printed with the same halftone dot area ratio and printing area under a visible light source, compared with the black (Bk) printing part. The ink printing part has a lower density. That is, it can be said that the metallic gloss ink has higher brightness (low density) than black (Bk) under a visible light source. Further, the metallic gloss ink has such a property that the printed image can be observed under a visible light source or an infrared light source. From the above, in Patent Document 3, the halftone dots forming the latent image of Patent Document 1 are replaced with metallic luster ink from black (Bk), thereby achieving high brightness (low density) under a visible light source. In addition, it is possible to form a latent image that is visible only under an infrared light source.

Japanese Patent No. 3544536 JP 2007-152805 A JP 2008-132600 A

  The halftone dot prints disclosed in Patent Literature 1 and Patent Literature 3 are called a visible image that can be recognized with visible light and a latent image that can be visually recognized using an appraisal device such as an infrared camera due to a special halftone dot configuration. It was possible to produce two images inexpensively. However, since the latent image cannot be visually recognized unless an appraisal device such as an infrared camera is used, for example, inspectors in various window operations such as banks and immigration examinations cannot perform authenticity determination by visual inspection. There was a problem. Therefore, various counter services such as banking and immigration control examinations require anti-counterfeit printed matter to which an inspector is provided with a technique capable of visually authenticating without using an appraisal device.

  Further, in the printed matter for preventing forgery disclosed in Patent Document 2, a diffused light visually recognized image including a first region, a second region, and a third region is visually recognized under a visible light source, and the first region In this case, the gloss image is visually recognized by tilting by forming it using metallic gloss ink, and the third region is formed by using black (Bk), so that it can be hidden by an identification device such as an infrared camera. An image is visually recognized. As described above, in the printed matter for preventing forgery, three images change under different observation conditions. However, the printed matter for preventing counterfeiting in Patent Document 2 is different from Patent Document 1 having a special halftone dot configuration, and may obtain a counterfeit product by ink jet printing or the like by obtaining each ink. Moreover, it is difficult to produce a printed matter for preventing counterfeiting with a design in which three images are overlapped on the same region, and there is a problem that the design is restricted.

  The present invention has been made to solve the above-mentioned problems. Specifically, cyan (C), magenta (M), yellow (Y), and black (Bk) inks, and surrounding printing depending on the observation angle. It is possible to determine authenticity by visual inspection and an appraisal device using a material whose area and color difference ΔE change. In other words, the normal state (diffuse light region), the state with different observation angles (regular reflection light region), and the infrared region, different images appear under multiple conditions, and each is subject to design constraints. It is an object of the present invention to provide a printed material having a latent image that never happens.

  In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that a printing region is formed at least partially on the substrate, and the printing region is composed of a first region, a second region, and a third region. A printed material having a continuous tone visible image, a first latent image, and a latent image embedded with a second latent image using the first region, the second region, and the third region. The central region is arranged so as to be surrounded by the first region, and the central region is arranged at equal intervals along the outer periphery of the first region with a smaller area than the first region, and the second region Is disposed in the first region or in the central region, and the third region is the central region when at least a part of the second region is disposed in the first region. Or in the first region and at least one when the second region is located in the central region. Is disposed within the first region, the first region is disposed with a halftone dot formed of a material not containing an infrared absorbing dye, a visible image is formed by the first region, and the second region is It consists of a second halftone dot portion and a second camouflage portion, and the second halftone dot portion changes the observation angle with respect to the illumination light source at a fixed position by changing the observation angle from the diffuse light region to the regular reflection light region. The color difference ΔE with the camouflage portion is formed of a material whose predetermined value changes, and a first latent image is formed by the second halftone dot portion, and the second camouflage portion has a second halftone dot in the diffused light region. The third region is composed of a third halftone dot portion and a third camouflage portion, and is formed using a material containing an infrared absorbing dye around the second halftone dot portion. The third halftone dot portion is formed using a material containing an infrared absorbing dye, and the second halftone dot portion The third camouflage portion is the same color as the third halftone dot portion under a visible light source, and uses a material that does not contain an infrared absorbing dye around the third halftone dot portion. The visible image is an image that is visible under a visible light source, and the first latent image image has its observation angle changed from a diffused light region to a regular reflected light region with respect to a fixed position illumination light source. The second latent image is an image that can be observed under an infrared light source.

In the invention according to claim 2, a printing region is formed at least in part on a substrate, and the printing region includes a first region, a second region, and a third region, and the first region. Using the second region and the third region, a printed matter having a continuous tone visible image, a first latent image and a latent image embedded with a second latent image, The base material is formed using a material that changes color by changing an observation angle with respect to an illumination light source at a fixed position from a diffuse light region to a regular reflection light region, and an infrared absorbing dye is formed on the base material. And a concealing region is formed using a concealing material that does not change the color by changing the observation angle with respect to the illumination light source at a fixed position from the diffused light region to the regular reflection light region. The concealing region includes a region where a concealing material for concealing the base material is applied and the base The first region, the second region, and the third region are disposed on the region to which the concealing material is applied, and the first region, the second region, and the third region are disposed on the first region. A central region is disposed so as to be surrounded, and the central region is disposed at equal intervals along the outer periphery of the first region with an area smaller than the first region, and the second region includes at least one When the portion is disposed in the first region or in the central region, and the third region is disposed when at least part of the second region is disposed in the first region. When the second region is disposed in the central region or the first region, and at least a portion of the second region is disposed in the first region, the first region, A halftone dot formed of a material containing no infrared absorbing dye is disposed, The visible image is formed by one region, the second region is composed of a second halftone dot portion and a second camouflage portion, and the second halftone dot portion and the region where the concealing material is not applied, Arranged at the same position, the second halftone dot portion has neither the material containing the infrared absorbing dye nor the material containing the infrared absorbing dye, and the same size as the region where the concealing material is not applied. The first latent image is formed by the second halftone dot portion formed by exposing the substrate partly through a region that is arranged in the same shape and not provided with the concealing material, The second camouflage portion is formed of a material that is the same color as the second halftone dot portion in the diffused light region and includes an infrared absorbing dye around the second halftone dot portion, The third area consists of the third halftone dot and the third cam The third halftone dot portion is formed using a material containing an infrared absorbing dye, and the third latent image is formed by the third halftone dot portion, The camouflage part is color-matched with the third halftone dot part under a visible light source, and is formed using a material that does not contain an infrared-absorbing dye around the third halftone dot part. The first latent image is a visible image under a visible light source, and the first latent image is obtained by changing the observation angle with respect to the illumination light source at a fixed position from the diffuse light region to the regular reflection light region. And the second camouflage portion are images that can be visually recognized with a predetermined value change, and the second latent image is an image that can be observed under an infrared light source. .

  Further, in the invention according to claim 3, in the printed matter having the latent image according to claim 1 or 2, when arranged in the first area, the third area is arranged in the center area, When the second area is arranged in the central area, the third area is arranged in the first area.

  According to a fourth aspect of the present invention, in the printed matter having the latent image according to the first or second aspect, the second region and the third region are disposed in the first region, and the central region is within the central region. The first region, the second region, and the third region are not arranged.

  According to a fifth aspect of the present invention, in the printed matter having the latent image according to the first or second aspect, the second region is a first region adjacent to the first region and the first region, and / or Or when arranged over one third region adjacent to the first region, the third region is arranged in the central region, and when the second region is arranged in the central region, The third region is disposed across one first region adjacent to the first region and the first region and / or one second region adjacent to the first region. .

  Further, in the invention described in claim 6, a printing region is formed in at least a part on the base material, and the printing region includes a first region, a second region, and a third region. A printed matter having a continuous tone visible image, a first latent image, and a latent image embedded with a second latent image using the second region and the third region, the first region The central region is arranged so as to be surrounded by, the central region is arranged at equal intervals along the outer periphery of the first region with a smaller area than the first region, the second region and the third region, The first region is arranged with a halftone dot formed of a material that does not contain an infrared absorbing dye, a visible image is formed by the first region, and the second region is a second mesh. It consists of a dot part and a second camouflage part, and the second halftone dot part is an observation angle with respect to the illumination light source at a fixed position. By changing from the diffused light region to the specularly reflected light region, a color difference ΔE with the second camouflage portion is formed of a material that changes by a predetermined value, and a first latent image is formed by the second halftone dot portion, The second camouflage part is the same color as the second halftone dot part in the diffused light region, is formed using a material containing an infrared absorbing dye around the second halftone dot part, and the third region is , A third halftone dot portion and a third camouflage portion, the third halftone dot portion is formed using a material containing an infrared absorbing dye, and the second halftone dot image is formed by the third halftone dot portion. The third camouflage part is formed using a material that is the same color as the third halftone dot part under a visible light source and does not contain an infrared absorbing dye around the third halftone dot part, The visible image is an image that is visible under a visible light source, and the first latent image is the illumination light at a fixed position. The image can be viewed by changing the observation angle with respect to the source from the diffuse light region to the specular light region, and the second latent image is an image that can be observed under an infrared light source. .

  According to a seventh aspect of the present invention, in the printed matter having the latent image according to the sixth aspect, the second area is disposed in the central area adjacent to the third area.

  According to an eighth aspect of the present invention, in the printed matter having the latent image according to the sixth aspect, the second region is arranged so as to be superimposed or removed with the third halftone dot portion, and the second camouflage portion is , And shared with the third halftone dot portion.

  In the invention according to claim 9, a print area is formed at least on a part of the substrate, and the print area includes a first area, a second area, and a third area. A printed matter having a continuous tone visible image, a first latent image, and a latent image embedded with a second latent image using the second region and the third region, the first region Is formed adjacent to the other first region in the first direction to form a first region group, a plurality of the first region group is arranged in parallel in the first direction, The second region and the third region correspond to the first region in a region sandwiched between the first region group and another first region group arranged adjacent to the first region group. In the first area, halftone dots formed of a material not containing an infrared absorbing dye are arranged, and a visible image is formed by the first area. This area is composed of a second halftone dot portion and a second camouflage portion, and the second halftone dot portion changes the observation angle from the diffuse light region to the regular reflection light region with respect to the illumination light source at a fixed position. Thus, the second camouflage portion is formed of a material whose color difference ΔE from the second camouflage portion changes by a predetermined value, the first halftone image is formed by the second halftone dot portion, and the second camouflage portion is The second halftone dot portion is the same color as the second halftone dot portion, and is formed using a material including an infrared absorbing dye around the second halftone dot portion. The third region includes the third halftone dot portion and the third camouflage. The third halftone dot portion is formed using a material containing an infrared absorbing dye, the second halftone dot portion forms a second latent image, and the third camouflage portion is visible. It is the same color as the third halftone dot under the light source and does not contain infrared absorbing dye around the third halftone dot The visible image is an image that is formed using a material and is visible under a visible light source, and the first latent image has an observation angle with respect to the illumination light source at a fixed position from the diffused light region to the regular reflected light region. The second latent image is an image that can be viewed by being changed, and the second latent image is an image that can be observed under an infrared light source.

  The invention described in claim 10 is the printed matter having the latent image according to claim 9, wherein the first direction is the center in the first region and the other first region adjacent to the first region. The direction is parallel to a straight line passing through the center.

  The invention described in claim 11 is the printed material having the latent image according to any one of claims 1 to 10, wherein the material whose color difference ΔE changes by a predetermined value is an illumination light source at a fixed position. By changing the observation angle from the diffuse light region to the regular reflection light region, the color difference ΔE from the second camouflage portion in the regular reflection light region to the color difference ΔE from the second camouflage portion in the diffuse light region, It is a material that changes by 5 or more.

  According to a twelfth aspect of the present invention, in the printed matter having the latent image according to any one of the first to eleventh aspects, the material in which the color difference ΔE from the second camouflage portion changes by a predetermined value is a glitter property. It is a material.

  Furthermore, the invention described in claim 13 is the printed material having the latent image according to any one of claims 1 to 12, wherein the glittering material is any one of metal powder ink, foil, metal, or metallic glossy film. It is a material.

  When the printed matter having the latent image of the present invention is observed in a diffused light region under a visible light source, the visible image can be visually recognized, and the first latent image can be visually recognized by observing the printed matter at an angle. When the image is observed using an appraisal device such as a camera, the second latent image is visible. In other words, it is possible to form three images with different viewing conditions on a single printed matter, and it is possible to perform double verification of authenticity determination using a simple method and authenticity determination using an appraisal device. . Therefore, inspectors in various window operations such as banking, immigration control examination, etc. can perform authenticity determination by visual inspection and authenticity determination by an appraisal device.

  Furthermore, the printed matter having a latent image according to the present invention can be easily produced in a design in which three images are overlapped in the same region by a special halftone dot configuration, and is not subject to design restrictions. .

An example of the top view and schematic diagram which show the printed matter which has a latent image image concerning this invention. The schematic diagram and sectional drawing which used for the base material (1) concerning this invention the material from which the color difference (DELTA) E with a 2nd camouflage part (4b) changes a predetermined value. 3 is a graph showing an example of spectral transmittance of white ink and magenta ink according to the present invention. The graph which shows an example of the spectral reflectance of the ink containing the base material (1) concerning this invention, metal powder ink, and infrared rays absorption pigment | dye. Printed matter (S) formed by the first halftone dot configuration according to the present invention, visible light source (R) when observed in a diffused light region and a specularly reflected light region with respect to a visible light source (R) at a fixed position The figure which showed three positional relationships of a viewpoint (E1, E2) and printed matter (S). The graph which shows color difference (DELTA) E of each 2nd halftone dot part (4a) and the 2nd camouflage part (4b) in the diffused light area | region or regular reflection light area | region concerning this invention. The top view and schematic diagram at the time of visually observing the printed matter (S) formed by the 1st halftone dot structure concerning this invention in the diffused light area | region under the visible light source (R) of a fixed position. The top view and schematic diagram at the time of visually confirming the printed matter (S) formed by the 1st halftone dot structure concerning this invention in the regular reflection light area | region under the visible light source (R) of a fixed position. The top view and schematic diagram at the time of observing printed matter (S) formed by the 1st halftone dot structure concerning this invention through apparatuses, such as an infrared display device, under an infrared light source (K). The schematic diagram which shows the modification of the 1st halftone dot structure concerning this invention. The schematic diagram which shows 2nd embodiment of this halftone dot structure which forms the image (2) shown to Fig.1 (a) concerning this invention. The schematic diagram which shows 3rd embodiment of this halftone dot structure which forms the image (2) shown to Fig.1 (a) concerning this invention. The top view and schematic diagram which show 4th embodiment of this halftone dot structure which forms the image (2) shown to Fig.1 (a) concerning this invention.

  Embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments to be described below, and various other embodiments can be implemented within the scope of the technical idea described in the claims.

  FIG. 1 is an example of a plan view and a schematic view showing a printed matter (hereinafter referred to as “printed matter”) having a latent image according to the present invention. As shown to Fig.1 (a), as for the printed matter (S) of this invention, the image (2) is formed by printing in at least one printing area on base materials (1), such as paper and a plastic card. Yes. Since the image (2) and the print area are the same area, the print area will be omitted below. The image (2) is a material in which the color difference ΔE between the commonly used cyan (C), magenta (M), yellow (Y), and black (Bk) inks and the surrounding area changes depending on the observation angle. Is forming. Image (2) is an image processing method in which two images composed of halftone dots on the same plane proposed by the present applicant in Japanese Patent No. 3544536 are arranged without overlapping each other by a special halftone dot configuration. It is generated by using a part of. A special halftone dot configuration will be described later.

  The visible image (6), the first latent image (7), and the second latent image (8) are embedded in the image (2) shown in FIG. By embedding each image in the image (2), it is visually recognized as a continuous-tone full-color image under a visible light source. Under different predetermined viewing conditions, a different image is visually recognized for each predetermined viewing condition. It becomes possible to do. The printed matter (S) of the present invention shown in FIG. 1 (a) has a normal viewing condition (first viewing condition) under a visible light source and a visible light source by the halftone dot configuration shown in FIG. 1 (b). Different images can be visually recognized according to a viewing condition (second viewing condition) in which the substrate (1) is tilted below and a viewing condition (third viewing condition) to observe under an infrared light source.

  When the image (2) shown in FIG. 1 (a) is observed in a diffused light region under a visible light source, the visible image (6) shown in FIG. 1 (c1) can be visually recognized. . Further, when the base material (1) is tilted under a visible light source, that is, when the image (2) shown in FIG. 1 (a) is observed in the specular reflection light region under the visible light source, FIG. It is possible to visually recognize the first latent image (7) composed of characters, face images, and the like shown in FIG. Furthermore, when observing with an appraisal device such as an infrared camera, it is possible to visually recognize the second latent image (8) composed of characters, face images, etc., as shown in FIG. 1 (c3). It becomes. Thus, the image (2) shown in FIG. 1 (a) has three different images. The visual recognition principle will be described later.

(First embodiment of the present halftone dot configuration in the present invention)
FIG. 1B is a schematic diagram showing a first embodiment of the present halftone dot configuration (hereinafter referred to as “first halftone dot configuration”). As shown in FIG. 1B, the image (2) is formed on the substrate (1) by the first region (3), the second region (4), and the third region (5). ing. The first region (3), the second region (4), and the third region (5) form an image (2) by arranging a plurality of regions in a matrix. By arranging each region in a matrix, the visible image (6), the first latent image (7), and the second latent image (8) are embedded in the image (2) without generating moire. It becomes possible.

  In the first halftone dot configuration, the central region (C) is arranged so as to be surrounded by the first region (3). The center region (C) is arranged at equal intervals along the outer periphery of the first region (3) with a smaller area than the first region (3). When the central region (C) is formed with an area larger than that of the first region (3), the third region (5) becomes noise under the visible light source, thereby reducing the visibility of the visible image (6). It is not preferable. The second region (4) is disposed in the first region (3), and the third region (5) is disposed in the central region (C). In addition, the arrangement | positioning location of 1st area | region (3), 2nd area | region (4), and 3rd area | region (5) in an image (2) is not limited to this, About the aspect of this form It will be described later.

  FIG. 1C1 is a diagram illustrating an example of a visible image (6) and a first region (3). The first region (3) is a region that forms a visible image (6) that is visible in the diffused light region under a visible light source. A first halftone dot portion (3a) is disposed in the first region (3). A plurality of visible images (6) are arranged in accordance with the area ratio between the first halftone dot part (3a) and the area other than the first halftone dot part (3a) in the first area (3). The first region (3) can provide gradation.

  The first halftone dot portion (3a) is formed using a material that does not contain an infrared absorbing dye. The first halftone dot portion (3a) is formed of a material that does not contain an infrared absorbing dye, so that the visible image (6) is visually recognized when observed using a special appraisal device such as an infrared camera. Can not be.

  In addition, it does not specifically limit in the material which does not contain an infrared absorption pigment | dye, if it does not have an infrared absorption characteristic, Well-known gravure ink, screen ink, process ink, etc. can be used. For example, among the basic four color inks, cyan (C), magenta (M), and yellow (Y) have the property of not absorbing infrared rays, and if these three colors are superimposed, a black system can be expressed. The same effect as a pigment that does not absorb infrared rays can be obtained. Alternatively, chromofine black ink (manufactured by Dainichi Seika Kogyo Co., Ltd.) or dye-based ink for an inkjet printer (for example, dye-based black ink manufactured by Canon, etc.) can also be used.

  FIG. 1C2 is a diagram illustrating an example of the first latent image (7) and the second region (4). The second region (4) is a region that forms a first latent image (7) that can be viewed by tilting the base material (1) under a visible light source, and the second halftone dot portion (4a). And a second camouflage portion (4b). A plurality of first latent image images (7) are arranged in accordance with the area ratio between the second halftone dot portion (4a) and the second camouflage portion (4b) in the second region (4). The second region (4) can provide gradation.

In the second region (4), the second halftone dot portion (4a) changes the observation angle with respect to the illumination light source at a fixed position from the diffused light region to the specularly reflected light region. It is formed using a material in which the color difference ΔE from (4b) changes by a predetermined value. The color difference in the present invention is defined by ΔE in the CIE 1976 L ^* a ^* b ^* color system. The CIE 1976 L ^* a ^* b ^* color system is a color space recommended by the CIE (International Lighting Commission) in 1976, and is defined in JIS Z 8729 in the Japanese Industrial Standards. The color difference is a distance in a color space between two colors, and the color difference in the CIE 1976 L ^* a ^* b ^* color system is the difference between the L ^* difference, the a ^* difference, and the b ^* difference between the two colors. It can be obtained by adding each squared and taking the square root.

  When the color difference ΔE changes, for example, a printing ink is produced by using a material whose brightness and / or color changes by changing the observation angle with respect to an illumination light source at a fixed position. To give a printed material A. Similarly, printing ink is prepared using a material that does not change brightness and / or color by changing the observation angle with respect to the illumination light source at a fixed position. Printed matter B is prepared. The color difference ΔE between the printed material A and the printed material B is X. Next, the color difference ΔE between the printed matter A and the printed matter B is measured again after changing the observation angle under the illumination light source in which the printed matter A and the printed matter B are placed at fixed positions. If the measured color difference ΔE is a value different from X described above, the color difference ΔE has changed. As described above, if the brightness and / or color changes by changing the observation angle with respect to the illumination light source at a fixed position, the material becomes a material whose color difference ΔE changes depending on the observation angle.

  The diffused light region in the present invention is a region where the light receiving angle is −10 to 10 ° when the incident light angle from the illumination light source at a fixed position is 45 °. When the incident light angle from the illumination light source is 45 °, it indicates a region where the light receiving angle is 35 to 55 °. The principle that the color difference ΔE changes by a predetermined value will be described later.

  Examples of the material in which the color difference ΔE with the second camouflage portion (4b) changes by a predetermined value depending on the observation angle include a glittering material. Examples of the glittering material include metal powder ink, foil (metal foil), those formed on the substrate (1) by metal vapor deposition, metals, and metallic glossy films. Metal powder ink is ink which shows a metal color by one printing. Metal powder ink is prepared by mixing a fine metal powder in a vehicle. Metal powder ink includes gold ink and silver ink. Gold ink is an ink prepared by mixing a fine brass powder in a vehicle, and silver ink is an ink prepared by mixing a fine aluminum powder in a vehicle. The printed material printed only with gold ink cannot see the first latent image (7) with the naked eye in the diffused light region under the visible light source. In the light region, it is visually recognized as a brilliant golden color with the naked eye. In addition, the printed matter printed only with silver ink cannot visually recognize the glossiness (gloss) with the naked eye in the diffuse light region under the visible light source, only the density is visible, and the positive light under the visible light source. In the reflected light region, it is visually recognized as brilliant silver with the naked eye.

  You may form a 2nd halftone dot part (4a) with foil (metal foil) instead of metal powder ink. Examples of the foil include gold leaf and silver leaf. The foil is applied onto the substrate (1) by a hot stamp method or a cold foil method. The hot stamping method is a method in which a sheet-like foil is stacked on a substrate, pressed with a high-temperature metal stamp, and pressed onto the substrate. The cold foil system is a system in which an adhesive is applied to the substrate (1), a sheet-like foil is stacked on the substrate, and the foil is transferred by pressing.

  Instead of foil (metal foil), aluminum (such as Takeo Co., Ltd., off metal N 165 kg, etc.) formed on the base material (1) by metal vapor deposition may be used. Moreover, it is good also considering base material (1) itself as metals, such as stainless steel and aluminum. Furthermore, you may use a metallic glossy film (Toray Industries, Inc., PICASUS etc.) for a base material (1). The metallic glossy film is a polyester film formed by laminating different kinds of polymers in multiple layers, and is a material that can obtain metallic gloss without using metal.

Further, as described above, the second halftone dot portion (4a) of the second region (4) is printed using a material in which the color difference ΔE from the second camouflage portion (4b) changes by a predetermined value. , Forming a second halftone dot (4a) on the substrate (1) using the printing ink, foil, etc. For the material (1) itself, a material whose color is changed by changing the observation angle with respect to the illumination light source at a fixed position from the diffuse light region to the regular reflection light region may be used. For example, a glittering material is used, and on the base material (1), the entire region excluding only the portion corresponding to the second halftone dot part (4a) does not contain an infrared absorbing dye, and the base material In (1), by changing the observation angle with respect to the illumination light source at a fixed position from the diffused light region to the regular reflection light region, a concealing material that does not change color (hereinafter referred to as “concealing material”) is printed. The printed matter thus obtained is obtained by changing the observation angle with respect to the illumination light source at a fixed position from the diffused light region to the regular reflection region, through the region (W ′) to which a concealing material described later is not applied. The color difference ΔE between the second halftone dot part (4a) formed by partially exposing the glittering material (1) and the second camouflage part (4b) changes by a predetermined value, The first latent image (7) becomes visible. That is, the material whose color changes by changing the observation angle with respect to the illumination light source at a fixed position on the base material (1) itself from the diffused light region to the regular reflected light region is the second The color difference ΔE between the halftone dot portion (4a) and the second camouflage portion (4b) changes a predetermined value.

  In the second region (4), the second halftone dot portion (4a) does not perform printing, so-called a state in which the second halftone dot portion (4a) is cut out in the second region (4). To do. By doing so, the second halftone dot portion (4a) can confirm the glitter of the base material (1) through the region where the concealing material is not printed, and as a result, the second halftone dot portion (4a) can be confirmed. The point (4a) is formed of a glittering material.

  FIG. 2 shows the configuration. As shown to Fig.2 (a), the concealment area | region (W) by a concealment material is formed on the glittering base material (1), and the halftone dot structure of this invention is formed on it with printing ink. However, about the 2nd halftone dot part (4a) of a 2nd area | region (4), neither the material containing an infrared absorption pigment | dye nor the material which does not contain an infrared absorption pigment | dye is arrange | positioned. In addition, a portion of the concealment region (W) that overlaps the second halftone dot portion (4a) is a region (W ′) where no concealment material is applied.

The concealing material can be white ink, mat ink (mat type OP varnish), etc., but does not contain an infrared absorbing dye, and the substrate (1) is viewed at an angle relative to the illumination light source at a fixed position. The material is not limited to this as long as the material does not change the color by changing the diffused light region to the regular reflection light region. The white ink includes Dicure RTX white manufactured by DIC Corporation as UV ink for offset printing, and LIOJET FV03 white manufactured by Toyo Ink Manufacturing Co., Ltd. as UV ink for inkjet printing.

  In FIG. 2A, FIG. 2B shows a cross-sectional view at Y1-Y2. As shown in FIG. 2 (a), in the printed layer forming the halftone dot structure of the present invention, nothing is printed on the second halftone dot portion (4a), and at the same time, the concealment region (W ) Also is a region (W ′) where a part of the masking material is not applied. The region (W ′) where the concealing material is not applied has the same size and the same shape as the second halftone dot portion (4a). Furthermore, since the second halftone dot portion (4a) and the region (W ′) to which no concealing material is applied are arranged at the same position, as an actual printed matter, the second halftone dot portion (4a) It is formed by exposing part of the glittering material as the base material (1) through the region (W ′) where the concealing material is not applied. That is, it is the same as the case where the second halftone dot portion (4a) is formed of a glittering material.

  It should be noted that the masking material is printed on the glittering substrate (1) because the visibility of the visible image (6) formed by the halftone dot composition of the present invention other than the second halftone dot part (4a). This is because it plays a role of hiding the glitter so as not to affect the brightness.

  The reason for using the concealing material that does not contain the infrared absorbing dye is that it does not affect the visibility of the second latent image (8) formed by the halftone dot structure of the present invention. When a concealing material containing an infrared absorbing dye is used, when the printed matter obtained by the halftone dot composition of the present invention is observed under an infrared light source, the first region (3), the second region (4) and The third region (5) is observed with a high density (darker). Therefore, the third halftone dot portion (5a) cannot be distinguished from other regions, and as a result, the second latent image (8) that can be observed under infrared light can be visually recognized. Disappear.

  Furthermore, the concealment region (W) formed of the concealment material preferably has a transmittance in the infrared region of 80% or less. When the transmittance in the infrared region of the concealment region (W) is 80% or more, the substrate (1) is concealed when the printed matter obtained by the halftone dot configuration of the present invention is observed under an infrared light source. The concealed area (W) to be transmitted is transmitted, and the first area (3), the second area (4) and the third area (5) are all transmitted and the base material (1) is observed. Is observed to be high (blackish). Therefore, the third halftone dot portion (5a) cannot be distinguished from other regions, and as a result, the second latent image (8) that can be observed under infrared light can be visually recognized. It is not preferable because it disappears.

  FIG. 3 is a graph showing an example of the spectral transmittance of white ink and magenta ink according to the present invention. FIG. 3 (a) shows the spectral transmittance of the concealment material in the present invention, using white ink as a measurement sample (LIOJET FV03 white manufactured by Toyo Ink Manufacturing Co., Ltd.), and performing solid printing on a PET film by inkjet printing. A thing was used. FIG. 3 (b) shows the spectral transmittance of the concealment material in the present invention. Using white ink (LIOJET FV03 White, manufactured by Toyo Ink Manufacturing Co., Ltd.) as a measurement sample, the PET film is formed by inkjet printing. A sample printed at a lower printing density was used.

  FIG. 3 (c) shows the spectral transmittance of the material that does not contain the infrared absorbing dye in the present invention. Using magenta ink (LIOJET FV03 Magenta manufactured by Toyo Ink Manufacturing Co., Ltd.) as a measurement sample, it is applied to a PET film by inkjet printing. A solid-printed one was used. The spectral transmittance shown in FIG. 3 is obtained by dividing the spectral transmittance of each measurement sample by the spectral transmittance of the PET film alone, which is a base material. (Measured using HITACHI U-4000 model).

  Comparing changes in spectral transmittance in the infrared region of 760 to 800 nm, the spectral transmittance in the concealing material (a) is almost constant at about 50% in any region. The spectral transmittance of the concealing material (b) printed at a reduced printing density is about 80% in the infrared region, which is a higher value than the concealing material (a) printed solid. The infrared transmitting material (c) containing no infrared absorbing pigment has a high value in the infrared region, about 95%, compared with the white ink (a) printed solid and the white ink (b) printed at a reduced printing density. It has become. In the case of a material that does not contain an infrared absorbing dye at the same wavelength, a lower spectral transmittance is visually recognized as a higher concentration (whiter), and conversely, a higher spectral transmittance has a lower concentration (transparent). It is visible. When observed with an infrared camera, the concealing material (a) is white, the concealing material (b) printed at a lower printing density is pale white, and the infrared transmitting material (c) is almost transparent. It was done.

  The substrate (1) itself may be formed of a glittering material, but metal powder ink or foil (metal foil) may be formed on the entire surface of the substrate (1) such as paper or plastic card.

  As described above, the second halftone dot portion (4a) in the present invention may be formed of a glittering material, specifically, metal powder ink, foil (metal foil), or the like. 1) Form itself with a glittering material or form a glittering material on the base material (1), and cover the glittering material with a concealing material except for only the second dot (4a). By forming a concealing layer, the second halftone dot portion (4a) may be formed substantially from the glitter material of the substrate (1). The printed matter obtained in FIG. 2 is obtained by changing the observation angle with respect to the illumination light source at a fixed position from the diffused light region to the regular reflection region, through the region (W ′) where no concealing material is applied. The color difference ΔE between the second halftone dot part (4a) formed by partially exposing the glitter material as the base material (1) and the second camouflage part (4b) changes by a predetermined value. Thus, the first latent image (7) becomes visible. In the following, the second halftone dot portion (4a) itself is not formed in the second halftone dot portion (4a) by using the glitter material on the base material (1) itself, but the second camouflage is used. A description will be given of an example in which the color difference ΔE with respect to the portion (4b) is changed by a predetermined value, specifically, an example of using a glittering material.

  In the modification of the first halftone dot configuration, the second halftone dot configuration, the third halftone dot configuration, and the fourth halftone dot configuration, which will be described later, similarly, on the glittering substrate (1), Needless to say, it is possible to form the concealment region (W) of the concealment material, and to form the halftone dot structure of the present invention thereon with the printing ink.

  In the second region (4), the second camouflage portion (4b) is the same color as the second halftone dot portion (4a) in the diffused light region, and around the second halftone dot portion (4a). It is formed using a material containing an infrared absorbing dye.

  The color matching in the present invention means that the color difference ΔE is less than 6. Generally, when the color difference ΔE is around 6, there is a possibility that the difference is visually recognized. However, as described above, in the present invention, the first region (3), the second region (4), and the third region (5) are fine and cannot be visually recognized by distinguishing each region. It is composed of various halftone dots. Therefore, if the color difference ΔE is less than 6 as described above, the second halftone dot portion (4a) cannot be visually recognized in the diffuse light reflection region under the visible light source, and the second The halftone dot part (4a) and the second camouflage part (4b) are visually recognized as the same color.

  Note that due to metamerism, when viewed in a diffused light region under a visible light source, a color visually recognized by the naked eye is viewed in a different color when observed in a diffused light region under a specific light source. Even in this case, in the present invention, it is assumed that the second halftone dot portion (4a) and the second camouflage portion (4b) are formed in the same color.

The area (vertical × horizontal) of each region in the first halftone dot configuration is, for example, the first region (3) formed by m × m in the configuration shown in FIG. If (4) is formed by n × n and the third region (5) is formed by k × k, it can be set as appropriate within the range of m>n> 0 and m>k> 0. is there. Preferably, the first region (3) is m × m (m ≧ 2, m is an integer), the third region (5) is k × k (k ≧ 1, k is an integer), the second region ( 4) is formed by n × n (n ≧ 1, n is an integer), and the area of the first region (3) is the sum of the areas of the second region (4) and the third region (5). Greater than (m ² > n ² + k ² ). When the area of the first region (3) is smaller than the sum of the areas of the second region (4) and the third region (5), when observed in the diffused light region under the visible light source, The second region (4) and the third region (5) become noise, which is not preferable because the visibility of the visible image (6) is lowered.

  FIG. 4 is a graph showing an example of the spectral reflectance of an ink containing a base material (1) according to the present invention, a metal powder ink, and an infrared absorbing dye. (A) in FIG. 4 is the spectral reflectance of the substrate (1) in the present invention, and photographic paper for an inkjet printer (Photo paper <Glossy> manufactured by EPSON) was used as a measurement sample. (B) is the spectral reflectance of the second halftone dot portion (4a) in the present invention, and solid printing by ink jet printing using a metal powder ink (manufactured by Nippon Paint Co., Ltd., gold colloid ink) as a measurement sample. The thing which gave is used. (C) is the spectral reflectance of the material containing the infrared-absorbing dye in the present invention, and the one that has been subjected to solid printing by inkjet printing using carbon black (matte black manufactured by EPSON) was used. The spectral reflectance was measured using a self-recording spectrophotometer (manufactured by HITACHI, model U-4000).

  Comparing changes in spectral reflectance in a visible light region of 400 to 760 nm and an infrared region of 760 to 800 nm, the spectral reflectance in the photographic paper (a) is almost constant at around 90% in any region. is there. The spectral reflectance of the metal powder ink (b) is lower than that of the photographic paper (a) in both the visible light region and the infrared region, and the metal powder ink (b) is about 50% in the infrared region. The value is lower than that of the photographic paper (a). The infrared absorbing ink (c) is almost constant at around 10% in any region, and is lower than that in the photographic paper (a) in the infrared region. At the same wavelength, the higher the spectral reflectance, the lower the density is visually recognized (whiter), and the lower the spectral reflectance, the higher the density (blackish) is visually recognized. When observed using an infrared camera, the photographic paper (a) was observed as white, the metal powder ink (b) as gray, and the infrared absorbing ink (c) as black.

  By changing the observation angle of the second halftone dot portion (4a) from the diffuse light region to the regular reflection light region with respect to the illumination light source at a fixed position, the color difference ΔE with the second camouflage portion (4b) is predetermined. The second camouflage portion (4b) is the same color as the second halftone dot portion (4a) in the diffused light region shown in FIG. In the diffused light region, the second dot portion (4a) and the second camouflage portion (4b) are formed by using a material containing an absorbing dye around the second dot portion (4a). Visible in the same color. Therefore, the second region (4) is in a uniform flat mesh state, and the first latent image (7) cannot be recognized with the naked eye.

  Moreover, when observing in an infrared region using a special appraisal device such as an infrared camera, the second halftone dot portion (4a) is visually recognized as having a higher density (blackish) than the base material (1). In addition, since the second camouflage portion (4b) is formed using a material containing an infrared absorbing dye, the concentration is higher (blackish) than the base material (1) when observed in the infrared region. ) Visible. Further, since the second camouflage portion (4b) is the same color as the second halftone dot portion (4a) in the diffused light region of the visible light region and uses a material containing an infrared absorbing dye, In the region, since the second halftone dot portion (4a) and the second camouflage portion (4b) cannot be identified, the first latent image (7) cannot be visually recognized. The area (4) is visually recognized as a solid area having a uniform density.

  The material containing the infrared absorbing dye includes black (Bk) mainly composed of carbon black. However, the material is not limited to this as long as the material has infrared absorption characteristics. The second halftone dot portion (4a) and the second camouflage portion (4b) can be formed by overlapping or removing the hair in the second region (4), but in the present invention, they are formed by overlapping. It is preferable to do. When forming by tapping, high printing accuracy is required. When the printing accuracy is low, a printed portion is generated around the second halftone dot portion (4a). Thereby, in the diffused light region under the visible light source, the second region (4) does not become a uniform flat net state, and the first latent image (7) may be visible with the naked eye. . Furthermore, when observed in the infrared region, the above-mentioned printed portion transmits infrared rays. Thereby, since the density of the printed portion is visually recognized as low, the second region (4) in the infrared region is not a solid region having a uniform density, and the first latent image (7) is May become observable.

  FIG. 1 (c3) is a diagram illustrating an example of the second latent image (8) and the third region (5). The third region (5) is a region for forming the second latent image (8) visible in the infrared light source shown in FIG. 1 (c3), and the third halftone dot portion (5a). And a third camouflage portion (5b). A plurality of second latent image images (8) are arranged according to the area ratio between the third halftone dot portion (5a) and the third camouflage portion (5b) in the third region (5). It is possible to give gradation by the third region (5). In the third region (5), the third halftone dot portion (5a) is formed using a material containing an infrared absorbing dye. In addition, the material containing the infrared absorbing dye includes black (Bk) mainly composed of carbon black. However, the material is not limited to this as long as the material has infrared absorption characteristics.

  In the third region (5), the third camouflage portion (5b) is formed in the same color as the third halftone dot portion (5a) using a material that does not contain an infrared absorbing dye. As described above, the uniform color in the present invention refers to a color that is visually recognized by the naked eye when observed in a diffused light region under a visible light source, and specifically, a color having a color difference ΔE of less than 6 To do. Note that due to metamerism, when viewed in a diffused light region under a visible light source, a color visually recognized by the naked eye is viewed in a different color when observed in a diffused light region under a specific light source. Even in this case, in the present invention, it is assumed that the third camouflage portion (5b) and the third halftone dot portion (5a) are formed in the same color.

  The third halftone dot portion (5a) is formed using a material containing an infrared absorbing dye, and the third camouflage portion (5b) is formed using a material not containing an infrared absorbing dye, By forming the same color as (5a), the third halftone dot portion (5a) and the third camouflage portion (5b) are visually recognized in the same color under a visible light source. Therefore, the third region (5) is in a uniform flat mesh state and the second latent image (8) cannot be recognized with the naked eye, but was observed using a special appraisal device such as an infrared camera. In some cases, the second latent image (8) can be viewed. The third halftone dot portion (5a) and the third camouflage portion (5b) can be formed in the third region (5) by overlapping or hair removal, but in the present invention, they are formed by overlapping. It is preferable to do. When forming by tapping, high printing accuracy is required. When the printing accuracy is low, a printed portion is generated around the third halftone dot portion (5a). Thereby, under the visible light source, the third region (5) does not have a uniform flat mesh state, and the second latent image (8) may be visible with the naked eye.

(Image viewing principle in the present invention)
The second halftone dot portion (4a) and the second camouflage portion (4b) are visually recognized in the same color in the diffused light region under the visible light source, so that the second halftone dot portion (4a) is visually recognized. In contrast, in the specularly reflected light region under the visible light source, the second halftone dot (4a) is visible with the naked eye. In general, the color of an object is determined by a light source, an observation environment (temperature), a spectral reflectance of the object, and the like. Although the way of visually recognizing colors varies depending on these observation conditions, in the present invention, the observation conditions are constant conditions (for example, observation conditions: the light source is D65, the observation environment is 20 ° C., etc.).

  FIG. 5 shows the visible light source (R) and the viewpoint (E1) when the printed matter (S) according to the present invention is observed in the diffused light region and the specular light region with respect to the visible light source (R) at a fixed position. , E2) and the printed material (S). When the visible light source (R), the viewpoint (E1), and the printed matter (S) are in the positional relationship shown in FIG. 5A, the observation is made in the diffused light region. In addition, when the visible light source (R), the viewpoint (E2), and the printed material (S) are in the positional relationship shown in FIG. 5B, the observation is made in the regular reflection light region.

  Next, the principle that the color difference ΔE between the second halftone dot portion (4a) and the second camouflage portion (4b) changes by a predetermined value due to the change in the observation angle will be described. As described above, the diffused light region in the present invention is a region where the light receiving angle is −10 to 10 ° when the incident light angle from the illumination light source at a fixed position is 45 °, and the specularly reflected light region is This is a region where the light receiving angle is 35 to 55 ° when the incident light angle from the illumination light source at a fixed position is 45 °. In the printed matter (S), the second halftone dot portion (4a) and the second camouflage portion (4b) are the same color in the positional relationship meaning the diffused light region shown in FIG. Cannot be visually recognized separately, only the visible image (6) is visually recognized.

  On the other hand, in the regular reflection light region shown in FIG. 5B, the second halftone dot portion (4a) is formed using a material whose brightness and / or color changes by changing the observation angle. . Thereby, by changing the observation angle from the diffuse light region to the regular reflection light region with respect to the illumination light source at a fixed position, the brightness and / or color changes, and the second halftone dot portion (4a) and the second halftone dot portion (4a) The color difference ΔE of the camouflage portion (4b) changes by a predetermined value. Therefore, the second halftone dot portion (4a) becomes visible and the first latent image (7) becomes visible.

  FIG. 6 is a graph showing the color difference ΔE of the second halftone dot portion (4a) and the second camouflage portion (4b) in the diffused light region or the specularly reflected light region according to the present invention. a) shows the color difference ΔE between the second halftone dot portion (4a) and the second camouflage portion (4b) in the diffused light region, and FIG. 6 (b) shows the second halftone dot portion in the specularly reflected light region. The color difference ΔE between (4a) and the second camouflage portion (4b) is shown. The halftone dot configuration in FIG. 6 is the same as the halftone dot configuration in FIG.

  The measurement sample consists of a base material (manufactured by EPSON) in which the first region (3) is 9 × 9 pixels, the second region (4) is 1 × 1 pixel, and the third region (5) is 2 × 2 pixels. On the sheet <Glossy>), the area ratio of the second halftone dot portion (4a) is set to 100% (the second camouflage portion (without the first region (3) and the third region (5)). 4b) was set to 0%), and measurement sample A (4 × 4 cm) produced by ink-jet printing using a metal powder ink (manufactured by Nippon Paint Co., Ltd., gold colloid ink) and the first region ( 3) Without printing the third region (5), the area ratio of the second camouflage part (4b) is set to 100% (the area ratio of the second halftone dot part (4a) is 0%), and black ink is used. (Matte black made by EPSON) and process ink (made by EPSON, cyan, ma Printer, Yellow) using, on the substrate (EPSON manufactured photographic paper <gloss>) was measured using a printed by inkjet printing the prepared measurement sample B (4 × 4cm).

  A graph showing the color difference ΔE of the second halftone dot portion (4a) and the second camouflage portion (4b) in the diffused light region shown in FIG. 6 (a), and the regular reflection light region shown in FIG. 6 (b) The difference in color ΔE between the second halftone dot part (4a) and the second camouflage part (4b) is a variable angle spectrophotometer GSP-2 type (manufactured by Murakami Color Research Laboratory Co., Ltd.). The L * value, the a * value, and the b * value of the measurement sample A and measurement sample B were measured, and the color difference ΔE was calculated from the obtained values.

  However, in order to reproduce the positional relationship meaning the diffused light region shown in FIG. 5A on the measuring apparatus, the incident light of the visible light source with respect to each measurement sample is fixed at 45 °, and the light receiving angle is −10 °. From 10 to 10 °. Further, in order to reproduce the positional relationship meaning the specularly reflected light region shown in FIG. 5B on the measuring apparatus, the incident light of the visible light source with respect to each measurement sample is fixed at 45 °, and the light receiving angle is set to 35 °. It was measured by changing the angle from 55 ° to 55 °. The calibration of the measuring apparatus was performed using a standard white plate 4020A with an incident light angle of 45 ° and a light receiving angle of 0 °, that is, a standard white plate with a completely diffusing surface.

  As shown in FIG. 6A, in the diffused light region, the color difference ΔE between the second halftone dot portion (4a) and the second camouflage portion (4b) is 1.43 at any light receiving angle. A relatively small value of ˜1.47 is shown. As described above, if the color difference ΔE is less than 6, the colors are the same color. Therefore, in the diffused light region, the second dot portion (4a) and the second camouflage portion (4b) can always be said to be the same color. Therefore, it is difficult to identify the second halftone dot portion (4a) and the second camouflage portion (4b) with the naked eye, and as a result, the first latent image formed in the image (2) ( 7) cannot be visually recognized.

  On the other hand, in the specular reflection light region shown in FIG. 6B, the color difference ΔE between the second halftone dot portion 4a and the second camouflage portion 4b is a light receiving angle indicating 7.38. Exists. In the diffused light region (for example, the light receiving angle 0 °), the color difference ΔE between the second halftone dot portion (4a) and the second camouflage portion (4b) is 1.45, and the specularly reflected light region (for example, The color difference ΔE between the second halftone dot portion (4a) and the second camouflage portion (4b) at a light receiving angle of 45 ° is 7.38. That is, by changing the observation angle from the diffused light region to the regular reflected light region, the color difference ΔE changes by 5.93 from 1.45 to 7.38. Therefore, when the color difference ΔE changes by 5 or more, the second halftone dot portion (4a) and the second camouflage portion (4b) can be identified with the naked eye, and as a result, formed in the image (2). It is possible to visually recognize the first latent image (7).

  Note that, under the same observation condition, the diffused light region and the regular reflected light region can be switched by tilting the base material (1). That is, by tilting the base material (1), the second halftone dot portion (4a) and the third camouflage portion (4b) can be identified with the naked eye. As a result, the first latent image (7) formed in the image (2) can be viewed.

(Visibility principle of visible image in the present invention)
FIG. 7 is a plan view and a schematic view when the printed matter (S) formed by the first halftone dot configuration according to the present invention is visually recognized in the diffused light region under the visible light source (R) at a fixed position. is there. In the printed matter (S) shown in FIG. 7A1, the first halftone dot portion 3A is visible with the naked eye in the diffused light region under the visible light source R as shown in FIG. 7A2. It becomes. That is, it becomes possible to visually recognize the visible image (6). The second halftone dot portion (4a) and the second camouflage portion (4b) are visually recognized in the same color in the diffused light region under the visible light source, and cannot be distinguished with the naked eye. The first latent image (7) formed at the halftone dot portion (4a) cannot be viewed with the naked eye.

  Further, since the third halftone dot portion (5a) and the third camouflage portion (5b) are visually recognized by the naked eye in the diffused light region under the visible light source, the third halftone dot portion (5a) and It becomes impossible to distinguish the third camouflage portion (5b). That is, the second latent image (8) cannot be visually recognized. Therefore, when the image (2) is viewed with the naked eye in the diffused light region under the visible light source (R), only the visible image (6) is visible.

  FIG. 7B is a schematic diagram when the printed matter (S) formed by the first halftone dot configuration is visually recognized in the diffused light region under the visible light source (R) at a fixed position. The principle that only the visible image (6) is visible with the naked eye in the diffused light region under the visible light source (R) will be described with reference to FIG. When the printed matter (S) is viewed with the naked eye in the diffused light region under the visible light source (R), first, in the first region (3), incident light (R1) from the visible light source (R). Thus, specularly reflected light (R2) and diffused light (R3) are generated, and diffused light (R3) is obtained in the diffused light region.

  In the second region (4), the incident light (R1) from the visible light source (R) generates specularly reflected light (R4) and diffused light (R5), and diffused light (R5) is obtained in the diffused light region. It is done. In addition, since the second region (4) is composed of the second halftone dot portion (4a) and the second camouflage portion (4b), both of them are specularly reflected light (not shown). Diffuse light (not shown) is obtained. The second halftone dot portion (4a) and the second camouflage portion (4b) are formed so as to have the same color when observed in the diffused light region under the visible light source. This difference cannot be confirmed with the naked eye.

  Further, in the third region (5), the incident light (R1) from the visible light source (R) generates specularly reflected light (R6) and diffused light (R7). In the diffused light region, the diffused light (R7) is generated. Is obtained. The third region (5) is composed of a third halftone dot portion (5a) and a third camouflage portion (5b). Diffuse light (not shown) is obtained. Since the third halftone dot portion (5a) and the third camouflage portion (5b) are formed so as to have the same color when observed in the diffused light region, the difference in diffused light in each region is It cannot be confirmed with the naked eye.

  In the halftone dot configuration of the present invention, the first region (3) has a larger area than the second region (4) and the third region (5). In the diffused light region under the visible light source, the intensity of the diffused light in the first region (3), the second region (4), and the third region (5) is substantially constant. Therefore, the first region (3) is configured to have a larger area than the second region (4), so that in the diffused light region under the visible light source, the first region that forms the visible image (6). The diffused light (R3) of (3) is observed more dominantly than the diffused light of the second region (4) and the third region (5). Therefore, in the diffused light region under the visible light source, when the printed matter (S) is observed, only the visible image (6) can be visually recognized, and the first latent image (7) and the second latent image are displayed. (8) cannot be visually recognized.

(First viewing principle of latent image in the present invention)
FIG. 8 is a plan view and a schematic view when the printed matter (S) formed by the first halftone dot configuration according to the present invention is visually recognized in the specular reflection light region under the visible light source (R) at a fixed position. It is. The printed matter (S) shown in FIG. 8 (a1) is visually recognized by the naked eye in the second halftone dot portion (4a) in the specularly reflected light region under the visible light source (R), as shown in FIG. 8 (a2). It becomes possible. That is, the first latent image (7) can be visually recognized. The second halftone dot portion (4a) and the second camouflage portion (4b) can be distinguished with the naked eye because the color difference ΔE changes and is visually recognized in the regular reflection light region under the visible light source. The first latent image (7) formed at the second halftone dot portion (4a) can be viewed with the naked eye.

  FIG. 8B is a schematic view when the printed matter (S) formed by the first halftone dot configuration according to the present invention is visually recognized in the regular reflection light region under the visible light source (R). The principle that the first latent image (7) is visible with the naked eye in the specularly reflected light region under the visible light source (R) will be described with reference to FIG. When the printed matter (S) is viewed with the naked eye in the specularly reflected light region under the visible light source (R), first, in the first region (3), incident light (R1) from the visible light source (R) is displayed. ) Generates specularly reflected light (R2) and diffused light (R3), and specularly reflected light (R2) is obtained in the specularly reflected light region.

  At the second halftone dot portion (4a) that forms the first latent image (7), regular reflection light (R4) is obtained. Further, the second camouflage portion (4b), the third halftone dot portion (5a), and the third camouflage portion (5b) are regularly reflected light (R6) by the incident light (R1) from the visible light source (R). And diffused light (R7) is generated, and specularly reflected light (R6) is obtained in the specularly reflected light region.

  Therefore, the second halftone dot part (4a) is formed of printing ink using a material whose brightness and / or color changes by changing the observation angle, and the second halftone dot part (4a). The regular reflection light (R4) is the regular reflection light (1) of the first region (3), the second camouflage part (4b), the third halftone dot part (5a), and the third camouflage part (5b). R6), and due to the difference in brightness, a color difference ΔE occurs in the second halftone dot portion (4a) with respect to the second camouflage portion (4b), and the first latent image (7 ). Therefore, in the regular reflection light region under the visible light source, when the printed matter (S) is observed, the first latent image (7) can be newly visually recognized.

  Note that, in the specularly reflected light region under the visible light source, the intensity of the incident light (R1) from the visible light source (R), the glossiness of the substrate (1), or the difference in the glossiness of the ink in each region is changed. Differences occur in the specular reflection light (R6) of the third halftone dot portion (5a) and the third camouflage portion (5b), and the third halftone dot portion (5a) and the third camouflage portion (5b) The color difference ΔE may change.

  However, the color difference ΔE from the second camouflage portion (4b) is changed by changing the observation angle of the second halftone dot portion (4a) with respect to the illumination light source at a fixed position from the diffuse light region to the regular reflection light region. Is formed using a material that changes a predetermined value, the amount of change in the color difference ΔE between the third halftone dot portion (5a) and the third camouflage portion (5b) is the second halftone dot portion ( 4a) and the change amount of the color difference ΔE between the second camouflage portion (4b). Therefore, it becomes impossible to distinguish the third dot portion (5a) and the third camouflage portion (5b) due to the visual masking effect. That is, the second latent image (8) cannot be visually recognized. Therefore, when the image (2) is visually recognized with the naked eye in the specularly reflected light region below the visible light source (R), the first latent image (7) can be newly visually recognized.

  The visual masking effect is due to the characteristics of human visual perception. When two large and small stimuli are given close in time and space, large stimuli are recognized and small stimuli are not recognized or recognized. It is known that a masking phenomenon (only a large stimulus is visible) that becomes difficult or results in the appearance of small stimuli is known, and this is called a visual masking effect. The setting of the area ratio between the second region (4) and the third region (5) and the observation angle for forming the second halftone dot portion (4a) are changed from the diffuse light region to the regular reflection light region. Thus, depending on the selection of a material in which the color difference ΔE from the second camouflage portion (4b) changes by a predetermined value, the amount of change in the color difference ΔE between the third halftone dot portion (5a) and the third camouflage portion (5b). However, it approximates the amount of change in the color difference ΔE between the second halftone dot portion (4a) and the second camouflage portion (4b), the visual masking effect is weakened, and the visibility of the first latent image (7) is reduced. May decrease.

  Therefore, the amount of change in the color difference ΔE between the second halftone dot portion (4a) and the second camouflage portion (4b) is equal to the color difference ΔE between the third halftone dot portion (5a) and the third camouflage portion (5b). The area ratio between the second region (4) and the third region (5) is set so as to be larger than the amount of change, or the observation angle for forming the second halftone dot portion (4a) is set as the diffused light region. It is preferable to appropriately select a material whose lightness and / or color changes by changing the light intensity from the normal reflection light region to the regular reflection light region.

(Principle of visual recognition of second latent image in the present invention)
FIG. 9 is a plan view and a schematic view when the printed matter (S) formed by the first halftone dot configuration according to the present invention is observed through an apparatus such as an infrared display device under an infrared light source (K). is there. The principle that the second latent image (8) can be observed under the infrared light source (K) will be described with reference to FIG. As shown in FIG. 9 (a2), when the printed matter (S) is observed with an infrared display device under an infrared light source (K), the first region (3) is made of a material that does not contain an infrared absorbing dye. Because it is composed, it is observed white.

  As shown in FIG. 4A and FIG. 4B, the second halftone dot portion (4a) is 40 in comparison with the photographic paper (a) whose spectral reflectance is the base material (1) in the infrared region. Since the concentration is lower by about%, the concentration is higher than that of the substrate (1) and is observed dark. The second camouflage part (4b) is configured using a material containing an infrared absorbing dye. By setting the second camouflage part to be the same color as the second halftone dot part (4a) in the diffused light area, When observed, it is observed at the same concentration as in FIG.

  That is, the second halftone dot portion (4a) and the second camouflage portion (4b) are observed in black because the spectral reflectance is about 40% lower than that of the photographic paper (a) as the base material in the infrared region. The Further, as shown in FIG. 4 (c), the third halftone dot portion (5a) has a spectral reflectance that is about 80% lower than that of the photographic paper (a) as the base material in the infrared region. It is observed darker than the second halftone dot part (4a) and the second camouflage part (4b). That is, as shown in FIG. 9 (a1), the substrate (1) is constituted by the third halftone dot portion (5a) rather than the solid region (9) constituted by the second region (4). The second latent image (8) thus made can be clearly observed.

  As described above, in the infrared light source (K), the solid region (9) can be observed, but the second latent image (8) in the present invention is formed by the third region (5). Say only images. Moreover, the solid image (9) may not be observed depending on the arrangement location of the first region (3), the second region (4), and the third region (5) in the image (2). This aspect will be described later.

(Modification of the first halftone dot configuration in the present invention)
FIG. 10 is a schematic view showing a modification of the first halftone dot configuration according to the present invention. As shown in FIG. 10 (a), the first halftone dot configuration is not limited to a quadrangular arrangement, and includes a first area (3), a second area (4), and a third area (5). It may be a square. For example, in FIG. 10A, as an example of another polygon arrangement, the first region (3) is a hexagon, the second region (4) is a pentagon, and the third region (5) is a triangle. It was.

  Further, in the first halftone dot configuration shown in FIG. 10A, the third region (5) arranged in the first region (3) may be circular. However, in the first halftone dot configuration, it is necessary to arrange the first region (3), the second region (4), and / or the third region (5) without any gap in the image (2). is there. When the gap is generated, a periodic plain portion is generated in the image (2), which is not preferable. Therefore, in the first region (3), the second region (4) and / or the third region (5), it is not preferable to form a circle. As shown in FIG. 10A, the first halftone dot configuration is not limited to the square arrangement, but the first region (3), the second region (4), and the third region (5). May be rectangular.

  Moreover, as shown in FIG.10 (b), you may provide a 2nd area | region (4) on a 1st halftone dot part (3a). However, when the second region (4) is arranged on the first halftone dot portion (3a), the visible image (6) is arranged on a portion other than the first halftone dot portion (3). In comparison, the proportion of the first halftone dot portion (3a) in the first region (3) is reduced. Thereby, compared with the first halftone dot configuration shown in FIG. 1B, the visibility of the visible image (6) is reduced, but the visible image (6), the first latent image (7) and Each second latent image (8) is visible.

  As shown in FIG. 10 (c), the second region (3) and the third region (4) are arranged in the first region (3), and the first region (C) includes the first region (C). It is also possible not to arrange any of the region (3), the second region (4), and the third region (5). However, when the second region (4) and the third region (5) are disposed in the first region (3), the third region (5) is disposed in the central region (c). As compared with the above, the proportion of the first halftone dot portion (3a) in the first region (3) is small. Thereby, compared with the first halftone dot configuration shown in FIG. 1B, the visibility of the visible image (6) is reduced, but the visible image (6), the first latent image (7) and Each second latent image (8) is visible.

  Further, as shown in FIG. 10 (d), the first halftone dot configuration includes a second region (4) that is adjacent to the first region (3) and the first region (3). The first region (3 ') and the first region (3) and one adjacent third region (5) are arranged across the third region (3) in the central region (C). You may arrange in.

  Further, although not shown, as another halftone dot configuration of FIG. 10D, the second region (4) is replaced with the first region (3) and one first region adjacent to the first region (3). You may arrange | position over one area | region (3 ') or 1st area | region (3), and its one adjacent 3rd area | region (5). In FIG. 10D, the second region (4) may be arranged on the third halftone dot portion (5a) by increasing the second region (4). In that case, the visibility of the second latent image (8) formed by the third halftone dot portion (5a) is lower than that of the first halftone dot configuration shown in FIG. 1 (b). However, the visible image (6), the first latent image (7), and the second latent image (8) are visible.

(Second embodiment of the present halftone dot configuration in the present invention)
FIG. 11 is a schematic diagram showing a second embodiment of the present halftone dot configuration (hereinafter referred to as “second halftone dot configuration”). As shown in FIG. 11 (a) and FIG. 11 (b), the image (2) is formed on the substrate (1) with the first region (3), the second region (4) and the third region. (5). The first area (3), the second area (4) and the third area (5) are a continuous tone visible image (6), a first latent image (7) and a second latent image, respectively. An image (8) is formed. The central region (C) is arranged so as to be surrounded by the first region (3), and the central region (C) is arranged at equal intervals along the outer periphery of the first region (3).

  As shown in FIG. 1B, the second camouflage portion (4b) and the third halftone dot portion (5a) are both formed using a material containing an infrared absorbing dye. Therefore, in the second halftone dot configuration, the second region (4) and the third region (5) are arranged in the central region (C), and the second region (4) is arranged in the third network. You may arrange | position with a dot part (5a) by superimposition or tweezers. At that time, the second camouflage part (4b) is arranged in the second halftone dot configuration in common with the third halftone part (5a).

  FIG. 11A shows the second region composed of the second halftone dot portion (4a ′) and the second camouflage portion (4b ′), the third halftone dot portion (4b ′) and the second halftone dot portion (4b ′). A third region consisting of three camouflage portions (4c ′) is arranged in the central region (C), and the second region (4 ′) is overlapped or removed with the third halftone dot portion (4a ′). The second camouflage portion (4b ′) is a second halftone dot configuration shared with the third halftone dot portion (4b ′).

  In the first region (3), a first halftone dot portion (3a) formed of a material not containing an infrared absorbing dye is disposed, and the second halftone dot portion (4a ′) has an observation angle at a fixed position. The illumination light source is formed using a material in which the color difference ΔE with the second camouflage portion (4b ′) changes by a predetermined value by changing from the diffused light region to the regular reflected light region, and is disposed in common. The second camouflage part (4b ′) and the third halftone dot part (4b ′) are formed using a material containing an infrared absorbing dye, and the third camouflage part (4c ′) contains an infrared absorbing dye. The second camouflage portion (4b ′) and the third halftone dot portion (4b ′) that are disposed in common are formed in the same color using a non-material.

  In the second halftone dot configuration shown in FIG. 11 (a), the visible image (6) is formed by the first halftone dot portion (3a ′), and the first latent image composed of characters, face images, and the like. The image image (7) is formed by the second halftone dot portion (4a ′). As described above, the color difference ΔE from the second camouflage portion (4b ′) is set to a predetermined value by changing the observation angle from the diffuse light region to the regular reflection light region with respect to the illumination light source at a fixed position under the infrared light source. Since the material whose value changes is observed to be dark due to its high concentration, the second halftone dot portion (4a ′), the second camouflage portion (4b ′) arranged in common and the third halftone dot portion ( 4b ') is observed as one halftone dot portion formed at a uniform concentration. Taking advantage of this characteristic, the second latent image (8) includes a second halftone dot portion (4a ′), a second camouflage portion (4b ′) and a third halftone dot portion arranged in common. (4b ').

  In the second region (4 ′), when the third halftone dot portion (4b ′) is arranged by overlapping or tweezers, the second camouflage portion (4b ′) is replaced with the third halftone dot portion (4b). Need to be smaller than '). As described above, the second latent image (8) includes the second halftone dot portion (4a ′), the second camouflage portion (4b ′) arranged in common and the third dot portion under the infrared light source. The halftone dot portion (4b ′) can be visually recognized by being observed as one halftone dot portion formed with a uniform density. Therefore, when the second camouflage portion (4b ′) is made larger than the third halftone dot portion (4b ′), the third halftone dot portion is superimposed on the second region (4 ′). Thus, the third halftone dot portion is arranged in the second camouflage portion (4b ′). As a result, a gradation shift of the image due to modulation of the magnitude relationship of the halftone dots constituting the second latent image (8) occurs, which is not preferable.

  Also in the second halftone dot configuration shown in FIG. 11 (a), the above-described base material (1) itself is formed of a glitter material or a glitter material is formed on a paper substrate, and the glitter property thereof is obtained. It is also possible to form a concealing layer with white ink on the material. At that time, the second halftone dot portion (4a ′) is formed as a region (W ′) where the concealing material is not applied, and further, the substrate (1) is formed via the region (W ′) where the concealing material is not applied. It is necessary to form by exposing a part of the glittering material. Therefore, it should be noted that the region (W ′) where the concealment material is not applied in the case of forming the concealment region (W) is different from other halftone dot configurations in the present invention.

  In the second halftone dot configuration shown in FIG. 11A, a second camouflage part (4b) arranged in common with the second halftone part (4a ′) under the infrared light source (K). Only ') and the third halftone dot portion (4b') can be observed, and the solid region (9) observed in the other embodiments described above is not observed.

  Moreover, as shown in FIG.11 (b), you may arrange | position 2nd area | region (4) adjacent to 3rd area | region (5) to center area | region (C). In FIG. 11B, the second region (4) and the third region (5) are arranged in the central region (C) with the same area as the third region (5). The ratio can be changed. Moreover, although the 2nd area | region (4) and the 3rd area | region (5) are arrange | positioned adjacent to the vertical direction, you may arrange | position adjacent to a horizontal direction. Further, although not shown, the central region (C) may be divided into two in the oblique direction, and the second region (4) and the third region (5) may be arranged adjacent to each other.

(Third embodiment of the present halftone dot configuration in the present invention)
FIG. 12 is a schematic diagram showing a third embodiment of the present halftone dot configuration (hereinafter referred to as “third halftone dot configuration”). As shown in FIG. 12A, the image (2) is formed on the substrate (1) by the first region (3), the second region (4), and the third region (5). ing. The first area (3), the second area (4) and the third area (5) are a continuous tone visible image (6), a first latent image (7) and a second latent image, respectively. An image (8) is formed.

  The first region (3) is arranged adjacent to the other first region (3 ') in the first direction (Y) to form the first region group (X1). The first direction (Y) is parallel to the straight line (X) passing through the center in the first region (3) and the center in the other first region (3a ′) adjacent to the first region (3). The same direction as the straight line A plurality of first region groups (X1) are arranged in series in the first direction (Y) as X1, X2, X3... Xn (n is an integer). The second region (4) and the third region (5) are the first region group (X2) arranged in parallel with the first region group (X1) and the first region group (X1). ) Are alternately arranged corresponding to the first region (3).

  The arrangement corresponding to the first region (3) means that one second region (4) and one third region (5) are respectively described with respect to one first region (3). It is to arrange at the position. In addition, as shown in FIG.12 (b), 2nd area | region (4) and 3rd area | region (5) are parallel to 1st area | region group (X1) and 1st area | region group (X1). After shifting in the same direction as the first direction to the region sandwiched between the other first region groups (X2) to be disposed, they may be alternately disposed corresponding to the first region (3). good. The second region (4) and the third region (5) are not necessarily arranged adjacent to each other, and as shown in FIG. 12 (c), the second region (4) and the third region (5) You may provide a space | gap between area | regions (5). Furthermore, as shown in FIG. 12D, the first region (5) may be arranged adjacent to the other first region in a direction orthogonal to the first direction (Y).

  In addition, the printed matter using the first halftone dot configuration, the second halftone dot configuration, and the third halftone dot configuration described above can visually recognize a visible image when observed in a diffused light region under a visible light source, The first latent image can be visually recognized by observing the printed material at an angle, and further, the second latent image can be visually recognized when observing with an identification device such as an infrared camera. However, if it is only necessary to obtain a printed material that can only be checked for authenticity by visual inspection, a halftone dot configuration that does not have the second region (4) (hereinafter referred to as “fourth halftone dot configuration”). Thus, two images with different viewing conditions can be formed on one printed matter. In other words, with the fourth halftone dot configuration, a visible image can be visually recognized when observed in the diffused light region under a visible light source, and the first latent image can be visually recognized by observing the printed material at an angle. Become. This will be described below.

  As shown in FIG. 13B, the image (2) is formed on the substrate (1) by the first region (3) and the third region (5). The first region (3) and the third region (5) form an image (2) by arranging a plurality of regions in a matrix. By arranging the regions in a matrix, the visible image (6) and the first latent image (7) can be embedded in the image (2) without generating moire.

  FIG. 13C1 is a diagram illustrating an example of the visible image (6) and the first region (3). The first region (3) is a region that forms a visible image (6) that is visible in the diffused light region under a visible light source. A first halftone dot portion (3a) is disposed in the first region (3). The first halftone dot portion (3a) is formed using an ink that does not contain an infrared absorbing dye. The first halftone dot portion (3a) is formed of a material that does not include infrared absorption characteristics, so that the visible image (6) is visually recognized when observed using a special appraisal device such as an infrared camera. Can not be.

  FIG. 13C2 is a diagram illustrating an example of the first latent image (7) and the third region (5). The third region (5) is a region that forms a first latent image (7) that can be viewed by tilting the base material (1) under a visible light source, and the third halftone dot portion (5a). And a third camouflage portion (5b). The third halftone dot portion (5a) has a predetermined color difference ΔE with respect to the third camouflage portion (5b) by changing the observation angle with respect to the illumination light source at a fixed position from the diffuse light region to the regular reflection light region. It is formed using a material whose value changes. The third camouflage part (5b) is the same color as the third halftone dot part (5a) in the diffused light region, and contains an infrared absorbing dye around the third halftone dot part (5a). It forms using.

  In the printed matter (S) shown in FIG. 13A, the first halftone dot portion (3a) is visible with the naked eye in the diffused light region under the visible light source. That is, it becomes possible to visually recognize the visible image (6). The third halftone dot portion (5a) and the third camouflage portion (5b) are visually recognized in the same color in the diffused light region under the visible light source, and cannot be distinguished with the naked eye. The first latent image (7) formed at the halftone dot portion (5a) cannot be viewed with the naked eye.

  In the printed matter (S) shown in FIG. 13A, the third halftone dot portion (5a) is visible with the naked eye in the specularly reflected light region under the visible light source. That is, the first latent image (7) can be visually recognized. The third halftone dot portion (5a) and the third camouflage portion (5b) can be distinguished with the naked eye because the color difference ΔE changes and is visually recognized in the regular reflection light region under the visible light source, The first latent image (7) formed at the third halftone dot portion (5a) can be viewed with the naked eye.

  With the fourth halftone dot configuration, the second latent image does not appear when viewed using an appraisal device such as an infrared camera, but is visible when observed in the diffused light region under a visible light source. A printed matter in which the image can be visually recognized and the first latent image can be visually confirmed by tilting and observing the printed matter has been produced. In the fourth halftone dot configuration, it is possible to form two images with different viewing conditions in one printed matter by changing only the material forming the first region (3). . For example, when observing in a diffused light region under a visible light source, a visible image can be visually recognized, and the first latent image can be visually recognized by observing the printed material at an angle, and further using an appraisal device such as an infrared camera. When this occurs, the visible image appears again. This will be described below.

  In the fourth halftone dot configuration, the first halftone dot portion (3a) is formed using an ink containing an infrared absorbing dye. The first halftone dot portion (3a) is formed of a material including infrared absorption characteristics, so that a visible image (6) that can be observed under two different observation conditions of a diffused light region and an infrared region under a visible light source is formed. This is a region to be formed. The third region (5) is formed of the same material as described above.

  In the printed matter (S) obtained from the above-described halftone dot configuration and material, the first halftone dot portion (3a) is visible with the naked eye in the diffused light region under the visible light source. That is, it becomes possible to visually recognize the visible image (6). The third halftone dot portion (5a) and the third camouflage portion (5b) are visually recognized in the same color in the diffused light region under the visible light source, and cannot be distinguished with the naked eye. The first latent image (7) formed at the halftone dot portion (5a) cannot be viewed with the naked eye.

  In the regular reflection light region under the visible light source, the third halftone dot portion (5a) is visible with the naked eye. That is, the first latent image (7) can be visually recognized. The third halftone dot portion (5a) and the third camouflage portion (5b) can be distinguished with the naked eye because the color difference ΔE changes and is visually recognized in the regular reflection light region under the visible light source, The first latent image (7) formed at the third halftone dot portion (5a) can be viewed with the naked eye.

  Furthermore, when observed through an apparatus such as an infrared display device under an infrared light source, the first halftone dot portion (3a) formed using an ink containing an infrared absorbing dye can be observed. That is, the visible image (6) appears again under the infrared light source.

  The third camouflage part (5b) is the same color as the second halftone dot part (5a) in the diffused light region, and a material containing an infrared absorbing dye around the third halftone dot part (5a). If it is the same color as the third halftone dot portion (5a) in the diffused light region, it is formed using a material that does not contain an infrared absorbing dye around the third halftone dot portion (5a). It is also possible to do.

  By changing the observation angle of the third halftone dot portion (5a) with respect to the illumination light source at a fixed position from the diffuse light region to the regular reflection light region, the color difference ΔE with the third camouflage portion (5b) is predetermined. The third camouflage part (5b) is the same color as the second halftone dot part (5a) in the diffused light region, and the third halftone dot part (5a) Even when it is formed using a material that does not contain an infrared absorbing dye around it, it is possible to visually recognize the first latent image (7) in the regular reflection light region under the visible light source.

  In the fourth halftone dot configuration, the third camouflage portion (5b) is the same color as the second halftone dot portion (5a) in the diffused light region, and red around the third halftone dot portion (5a). When formed using a material that does not contain an external absorbing dye, the resulting printed matter (S) is formed using an ink containing an infrared absorbing dye when observed through an apparatus such as an infrared display device under an infrared light source. The first halftone dot portion (3a) and the third halftone dot portion (5a) can be observed. That is, an image in which the visible image (6) and the first latent image (7) are superimposed appears under an infrared light source.

  The visible image (6), the first latent image (7), and the second latent image (8) of the present invention can be appropriately selected from characters, numbers, symbols, designs, landscapes, and the like. In the first latent image (7), it is preferable to form a positive image in the case of letters, numbers, symbols, figures, etc., and to form a negative image in the case of a person or landscape. preferable. The first halftone dot portion (3a), the second halftone dot portion (4a), and the third halftone dot portion (5a) each use a circular dot as a halftone dot shape, but are limited to a circle. Instead, a shape such as a triangle, a square, or a polygon, a random shape, or a halftone dot shape proposed in Japanese Patent No. 3478474 filed earlier by the present applicant may be used. .

  As a material for forming this halftone dot structure, known gravure ink, screen ink, process ink, ink for inkjet printer, foil (metal foil), and the like can be used. Moreover, as a method of forming each region on the substrate (1), an offset printing method, a gravure printing method, a screen printing method, a flexographic printing method, an ink jet printer, a laser printer, a metal vapor deposition, a hot stamp, a cold stamp, etc. It is not particularly limited.

  The substrate (1) used in the present invention is not particularly limited, and paper sheets such as high-quality paper, coated paper, and art paper, films, and the like can be used. In order to effectively exhibit the characteristics of the material whose brightness and / or color changes by changing the observation angle with respect to the illumination light source at a fixed position from the diffuse light region to the regular reflection light region, the base material (1) The smoothness is preferably not less than 1,000 seconds and less than 2,000 seconds. In addition, the measurement of smoothness was performed by the test method prescribed | regulated to JISP8119 of Japanese Industrial Standard, and it measured using the Digibeck smoothness tester (The Toyo Seiki Seisakusho Co., Ltd. make, DB-2 type | mold).

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

Example 1
As Example 1, a printed matter (S) was produced with the first halftone dot configuration shown in FIG. As for the printed matter (S), an image (2) was formed by an inkjet printer (PX-G930, manufactured by EPSON) using a photographic paper for inkjet printer (photographic paper <Gloss> manufactured by EPSON) as the base material (1). The area of each region in the first halftone dot configuration is such that the first region (3) is formed by 10 × 10 pixels, the second region (4) is formed by 2 × 2 pixels, The region (6) was formed with 4 × 4 pixels.

  In the first region (3), the first halftone dot portion (3a) is a circular dot and printed using process ink (manufactured by EPSON, cyan, magenta, yellow). The visible image (6) was formed by changing the area ratio between the first halftone dot portion (3a) and the region other than the first halftone dot portion (3a).

  In the second region (4), the second halftone dot part (4a) is a circular dot and printed using gold ink (manufactured by Nippon Paint Co., Ltd., gold colloid ink). Next, in the diffused light region under the visible light source, in order to make the second dot portion (4a) and the second camouflage portion (4b) visible as the same color, the second camouflage portion (4b) The color was set, and the second camouflage portion (4b) was set to black.

  The second camouflage portion (4b) was printed using black ink (EPSON mat black) and process ink (EPSON, cyan, magenta, yellow). The area ratio of the second halftone dot portion (4a) and the second camouflage portion (4b) was changed to form the first latent image (7).

  In the third region (5), the third halftone dot portion (5a) was a circular dot and was printed using black ink (matte black made by EPSON). The third camouflage part (5b) printed process ink (manufactured by EPSON, cyan, magenta, yellow) in black color. The area ratio of the third halftone dot portion (5a) and the third camouflage portion (5b) was changed to form the second latent image (8).

  When the printed matter (S) produced in Example 1 was observed with the naked eye in the diffused light region under the visible light source with the illumination light source at a fixed position, the visible image (6) was visible, and the first latent image (7) ) And the second latent image (8) were not visible. Next, the printed matter (S) produced in Example 1 was observed with the naked eye in a specularly reflected light region under a visible light source where the illumination light source was in a fixed position. The visible image (6) can be visually recognized, the second halftone dot portion (4a) is visually recognized in gold, and the second camouflage portion (4b) is visually recognized in black, whereby the first latent image (7) ) Was visible, but the second latent image (8) was not visible.

  When viewed with the naked eye in the specular reflection light region under the visible light source, the specular reflection light (R4) of the second halftone dot portion (4a) forming the first latent image (7) is the first region ( 3) The specularly reflected light (R6) of each of the second camouflage portion (4b), the third halftone dot portion (5a) and the third camouflage portion (5b) becomes higher, The color difference ΔE between the second halftone dot portion (4a) and the second camouflage portion (4b) changes greatly, and the first latent image (7) is more clearly visible than the visible image (6). Became possible.

  Furthermore, the printed matter (S) produced in Example 1 was mounted with an infrared display device (manufactured by Watec Co., Ltd., CCD camera WAT-704R, Fuji Photo Film Co., Ltd., Sharp Cut Filter IR-80) under an infrared light source. Observed). The visible image (6) was not observable, and the second area (4) was displayed as a dark area (gray) as a solid area (9) of uniform size. Further, the second latent image (8) composed of the third halftone dot portion (5a) is displayed darker (blackish) than the solid region (9), and the second latent image (8) is displayed. ) Was clearly visible.

(Example 2)
As Example 2, a printed matter (S) was produced with the second halftone dot configuration shown in FIG. In Example 2, the substrate (1) used an inkjet printer photographic paper (EPSON photographic paper <glossy>), and an image (2) was formed by an inkjet printer (EPSON PX-G930). In addition, the area of each area | region in this halftone dot structure formed the 1st area | region (3 ') by 10x10 pixel, and formed the 2nd area | region (4') by 5x5 pixel.

  In the first region (3 '), the first halftone dot portion (3a') is a circular dot, and was printed using process ink (manufactured by EPSON, cyan, magenta, yellow). The area ratio between the first halftone dot portion (3a ') and the region other than the first halftone dot portion (3a') was changed to form a visible image (6).

  In the second region (4 '), the second halftone dot portion (4a') was a circular dot, and was printed using gold ink (manufactured by Nippon Paint Co., Ltd., gold colloid ink). Next, in the diffused light region under the visible light source, the second halftone dot portion (4a ′), the second camouflage portion (4b ′), and the third camouflage portion (4c ′) are made visible as the same color. Therefore, the colors of the second camouflage part (4b ′) and the third camouflage part (4c ′) are set, and the second camouflage part (4b ′) and the third camouflage part (4c ′) are blackened. Color set.

  The second camouflage part (4b ′) is made of black ink (EPSON mat black) and process ink (EPSON, cyan, magenta, yellow) using the second halftone dot part (4a ′) and the third camouflage. It printed by parting together with a part (4c '). The third camouflage portion (4c ') was printed using process ink (manufactured by EPSON, cyan, magenta, yellow). The area ratio of the second halftone dot portion (4a ′), the second camouflage portion (4b ′), and the third camouflage portion (4c ′) is changed to change the first latent image (7) and the second A latent image (8) was formed.

  When the printed matter (S) produced in Example 2 was observed with the naked eye in the diffused light region under the visible light source with the illumination light source in a fixed position, the visible image (6) was visible, and the first latent image (7) ) And the second latent image (8) were not visible. Next, the illumination light source was observed with the naked eye in a specularly reflected light region under a visible light source at a fixed position. The visible image (6) is visible, the second halftone dot portion (4a ′) is visible in gold, and the second camouflage portion (4b ′) and the third camouflage portion (4c ′) are visible in black. As a result, the first latent image (7) was visible, but the second latent image (8) was not visible.

  When viewed with the naked eye in the specularly reflected light region under the visible light source, the specularly reflected light (R4) of the second halftone dot portion (4a ′) that forms the first latent image (7) is the first region. (3) The specularly reflected light (R6) of each of the second camouflage portion (4b ′) and the third camouflage portion (4c ′) is higher than the second halftone dot portion ( 4a ′) and the second camouflage portion (4b ′) are greatly changed in color difference ΔE, and the first latent image (7) can be clearly seen than the visible image (6). .

  Furthermore, the printed matter (S) produced in Example 2 was mounted with an infrared display device (manufactured by Watec Co., Ltd., CCD camera WAT-704R, Fuji Photo Film Co., Ltd., Sharp Cut Filter IR-80) under an infrared light source. Observed). The visible image (6) was not observable, and the second camouflage portion (4b ') and the second halftone dot portion (4a') were displayed dark (blackish) on the infrared display device. That is, only the second latent image (8) composed of the second halftone dot portion (4a ') and the second camouflage portion (4b') was visible.

1 substrate 2 image 3, 3 'the first region 3a, 3a', 3a '' , 3 'n first dot portions 4, 4' a second region 4a, 4a 'second meshed portion 4b '2nd camouflage part, 3rd halftone dot part 4c' 3rd camouflage part 5 3rd area 5a 3rd halftone part 5b 3rd camouflage part 6 Visible image 7 1st latent image 8th Second latent image 9 Solid area S Printed material W Concealed area C Central area R Visible light source K Infrared light source X1, X2 First area group Y First direction

Claims (13)

A printing area is formed on at least a part of the substrate, and the printing area includes a first area, a second area, and a third area, and the first area, the second area, and the third area. A printed matter having a latent image in which a continuous-tone visible image, a first latent image, and a second latent image are embedded,
A central region is arranged so as to be surrounded by the first region,
The central region is arranged at equal intervals along the outer periphery of the first region with a smaller area than the first region,
The second region is at least partially disposed within the first region or disposed in the central region;
The third region is disposed in the central region or the first region when at least a part of the second region is disposed in the first region, and the second region is When disposed in the central region, at least a portion is disposed in the first region;
The first region has a halftone dot formed of a material that does not contain an infrared absorbing dye,
The visible image is formed by the first region,
The second region comprises a second halftone dot portion and a second camouflage portion,
The second halftone dot portion is a material whose color difference ΔE with the second camouflage portion changes by a predetermined value by changing the observation angle with respect to the illumination light source at a fixed position from the diffuse light region to the regular reflection light region. Formed with
The first latent image is formed by the second halftone dot portion,
The second camouflage portion is the same color as the second halftone dot portion in the diffused light region, and is formed using a material containing an infrared absorbing dye around the second halftone dot portion,
The third region consists of a third halftone dot portion and a third camouflage portion,
The third halftone dot portion is formed using a material containing an infrared absorbing dye,
The second latent image is formed by the third halftone dot portion,
The third camouflage portion is color-matched with the third halftone dot portion under a visible light source, and is formed using a material that does not contain an infrared absorbing dye around the third halftone dot portion,
The visible image is an image that is visible under a visible light source, and the first latent image is visually recognized by changing the observation angle with respect to a fixed-position illumination light source from a diffuse light region to a regular reflection light region. A printed material having a latent image, wherein the second latent image is an image that can be observed under an infrared light source.

A printing area is formed on at least a part of the substrate, and the printing area includes a first area, a second area, and a third area, and the first area, the second area, and the third area. A printed matter having a latent image in which a continuous-tone visible image, a first latent image, and a second latent image are embedded,
The base material is formed using a material whose color changes by changing the observation angle from the diffuse light region to the regular reflection light region with respect to the illumination light source at a fixed position,
A concealing material which does not contain an infrared absorbing dye on the base material and does not change color by changing the observation angle of the base material from a diffused light region to a regular reflection light region with respect to an illumination light source at a fixed position. A concealment region is formed using
The concealing region is composed of a region where a concealing material for concealing the base material is applied and a region where a concealing material for partially exposing the base material is not applied,
On the region where the concealing material is applied, the first region, the second region and the third region are arranged,
A central region is arranged so as to be surrounded by the first region,
The central region is arranged at equal intervals along the outer periphery of the first region with a smaller area than the first region,
The second region is at least partially disposed within the first region or disposed in the central region;
The third region is disposed in the central region or the first region when at least a part of the second region is disposed in the first region, and the second region is When disposed in the central region, at least a portion is disposed in the first region;
The first region has a halftone dot formed of a material that does not contain an infrared absorbing dye,
The visible image is formed by the first region,
The second region comprises a second halftone dot portion and a second camouflage portion,
The second halftone dot portion and the region not provided with the concealing material are arranged at the same position
The second halftone dot portion is arranged in the same size and the same shape as the region not including the material containing the infrared absorbing dye and the material not containing the infrared absorbing dye, and not applying the concealing material,
The first latent image is formed by the second halftone dot portion formed by partially exposing the base material through a region where the concealing material is not applied,
The second camouflage portion is the same color as the second halftone dot portion in the diffused light region, and is formed using a material containing an infrared absorbing dye around the second halftone dot portion,
The third region consists of a third halftone dot portion and a third camouflage portion,
The third halftone dot portion is formed using a material containing an infrared absorbing dye,
The second latent image is formed by the third halftone dot portion,
The third camouflage portion is color-matched with the third halftone dot portion under a visible light source, and is formed using a material that does not contain an infrared absorbing dye around the third halftone dot portion,
The visible image is an image that is visible under a visible light source, and the first latent image is obtained by changing an observation angle from a diffused light region to a regular reflected light region with respect to an illumination light source at a fixed position. The color difference ΔE between the second halftone dot portion and the second camouflage portion changes by a predetermined value and becomes visible, and the second latent image is an image that can be observed under an infrared light source. A printed matter having a latent image.

  When the second region is disposed in the first region, the third region is disposed in the central region, and when the second region is disposed in the central region, The printed matter having a latent image according to claim 1, wherein the third region is arranged in the first region. The second region and the third region are disposed within the first region;
The printed matter having a latent image according to claim 1, wherein none of the first region, the second region, and the third region is disposed in the central region.   The second region is disposed across the first region and one first region adjacent to the first region and / or one third region adjacent to the first region. The third region is disposed in the central region, and the second region is disposed in the central region, the third region is defined as the first region and the first region. 3. The latent image according to claim 1, wherein the latent image is arranged across one first region adjacent to the region and / or one second region adjacent to the first region. Having printed matter. A printing area is formed on at least a part of the substrate, and the printing area includes a first area, a second area, and a third area, and the first area, the second area, and the third area. A printed matter having a latent image in which a continuous-tone visible image, a first latent image, and a second latent image are embedded,
A central region is arranged so as to be surrounded by the first region,
The central region is arranged at equal intervals along the outer periphery of the first region with a smaller area than the first region,
The second region and the third region are arranged in a central region;
The first region has a halftone dot formed of a material that does not contain an infrared absorbing dye,
The visible image is formed by the first region,
The second region comprises a second halftone dot portion and a second camouflage portion,
The second halftone dot portion is a material in which the color difference ΔE with the second camouflage portion changes by a predetermined value by changing the observation angle with respect to the illumination light source at a fixed position from the diffused light region to the regular reflected light region. Formed with
The first latent image is formed by the second halftone dot portion,
The second camouflage portion is the same color as the second halftone dot portion in the diffused light region, and is formed using a material containing an infrared absorbing dye around the second halftone dot portion,
The third region consists of a third halftone dot portion and a third camouflage portion,
The third halftone dot portion is formed using a material containing an infrared absorbing dye,
The second latent image is formed by the third halftone dot portion,
The third camouflage portion is color-matched with the third halftone dot portion under a visible light source, and is formed using a material that does not contain an infrared absorbing dye around the third halftone dot portion,
The visible image is an image that is visible under a visible light source, and the first latent image is visually recognized by changing the observation angle with respect to a fixed-position illumination light source from a diffuse light region to a regular reflection light region. A printed material having a latent image, wherein the second latent image is an image that can be observed under an infrared light source.   The printed matter having a latent image according to claim 6, wherein the second region is disposed in the central region adjacent to the third region. The second region is arranged by overlapping or tweezing with the third halftone dot portion,
7. The printed matter having a latent image according to claim 6, wherein the second camouflage portion is disposed in common with the third halftone dot portion. A printing area is formed on at least a part of the substrate, and the printing area includes a first area, a second area, and a third area, and the first area, the second area, and the third area. A printed matter having a latent image in which a continuous-tone visible image, a first latent image, and a second latent image are embedded,
The first region is disposed adjacent to the other first region in the first direction to form a first region group,
A plurality of the first region groups are arranged in parallel in the first direction,
The second region and the third region are arranged in a region sandwiched between the first region group and another first region group arranged adjacent to the first region group. Alternately arranged corresponding to the area of
The first region has a halftone dot formed of a material that does not contain an infrared absorbing dye,
The visible image is formed by the first region,
The second region comprises a second halftone dot portion and a second camouflage portion,
The second halftone dot portion is a material whose color difference ΔE with the second camouflage portion changes by a predetermined value by changing the observation angle from the diffuse light region to the regular reflection light region with respect to the illumination light source at a fixed position. Formed with
The first latent image is formed by the second halftone dot portion,
The second camouflage portion is the same color as the second halftone dot portion in the diffused light region, and is formed using a material containing an infrared absorbing dye around the second halftone dot portion,
The third region consists of a third halftone dot portion and a third camouflage portion,
The third halftone dot portion is formed using a material containing an infrared absorbing dye,
Forming the second latent image by the third halftone dot portion;
The third camouflage portion is color-matched with the third halftone dot portion under a visible light source, and is formed using a material that does not contain an infrared absorbing dye around the third halftone dot portion,
The visible image is an image that is visible under a visible light source, and the first latent image is visually recognized by changing the observation angle from a diffused light region to a specularly reflected light region with respect to an illumination light source at a fixed position. A printed material having a latent image, wherein the second latent image is an image that can be observed under an infrared light source.   10. The first direction is a direction parallel to a straight line passing through a center in the first region and a center in another first region adjacent to the first region. Printed matter having a latent image.   The material in which the color difference ΔE changes by a predetermined value means that the observation angle with respect to the illumination light source at a fixed position is changed from the diffuse light region to the regular reflection light region, so that the second camouflage portion in the diffuse light region is 11. The latent image according to claim 1, wherein the color difference ΔE is a material in which a color difference ΔE with the second camouflage portion in the regular reflection light region changes by 5 or more with respect to the color difference ΔE. Printed matter having.   The printed material having a latent image according to any one of claims 1 to 11, wherein the material in which the color difference ΔE with the second camouflage portion changes by a predetermined value is a glittering material.   The printed matter having a latent image according to any one of claims 1 to 12, wherein the glittering material is any one of metal powder ink, foil, metal, and metallic glossy film.

Images