Authenticity-determinable printed matter and method for creating image data for authenticity-determinable printed matter

Abstract

To provide an authenticity discriminable printed matter in which authenticity discrimination can be performed under a prescribed condition, a print pattern is constituted of an assembly of patterns of characters and symbols that express a pattern recognized when observing the print pattern under visible light with high definition and hides a pattern constituting a latent image without influencing on a pattern recognized under visible light.SOLUTION: A base material has a printed pattern in which a plurality of information patterns such as characters and symbols are arranged, and the printed pattern is divided into, due to partial difference of an area rate of information pattern, a first image part and a common image part that constitute first significant information that can be visually recognized under visible light and a second image part and a background part that become a background of the first significant image, the common image part and information pattern constituting the second image part have the same color with the first image part and the background part, and by including a functional material recognizable under a predetermined observation condition, the second significant information recognizable under a predetermined observation condition was formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to printed matter that can be authenticated in the field of security printed matter such as banknotes, passports, securities, identification cards, cards, and travel tickets that require anti-counterfeiting effects, in which a latent image is visible when the printed pattern formed by letters and symbols is observed under specified observation conditions. [Background technology]

[0002] Recent advances in digital devices such as scanners, printers, and color copiers have made it easy to create copies of security printouts. To prevent such copying and counterfeiting, anti-counterfeiting technologies that cannot be reproduced by printers or copiers have been proposed.

[0003] Examples of counterfeit prevention technologies that cannot be reproduced by printers or copiers include magnetic ink, fluorescent ink, and infrared absorbing ink that exhibits absorption properties in the infrared region. These functional inks can only be recognized using specific light sources or sensors, and because they are not used in general printers or copiers, they can prevent the counterfeiting of security prints.

[0004] On the other hand, security prints not only prevent counterfeiting by using the aforementioned anti-counterfeit ink, but can also be created by combining patterns such as background patterns, colored patterns, portraits, etc. of the security print with text that displays information about the printed material, such as the manufacturer, production date, and production lot.

[0005] As one example, the present applicant has proposed a printed matter in which functional ink having infrared absorption properties and fluorescent emission properties is used for part of a printed pattern made up of a plurality of minute characters and symbols (see, for example, Patent Document 1). Because the characters and symbols that make up the printed pattern of the printed matter in Patent Document 1 are minute, when the printed matter is observed under magnification with a magnifying glass, the characters and symbols can be recognized, making it possible to determine whether the printed matter is genuine, and also making it possible to determine whether it is genuine or not based on the position and information of the characters and symbols formed with the functional ink.

[0006] The applicant has also proposed a printed matter in which a plurality of halftone dot figures that express continuous gradation using characters, logos, symbols, etc. are formed, and different continuous gradation patterns are visible under visible light and infrared light (see, for example, Patent Document 2). The printed matter in Patent Document 2 is configured to express continuous gradation by overlapping a first figure (halftone dot) made of ink that does not contain infrared-absorbing pigment with a second figure (halftone dot) made of ink that contains metal powder, and by varying the area of ​​each halftone dot figure. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-335085 [Patent Document 2] Patent No. 4997531 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the technology of Patent Document 1, by forming some of a plurality of minute characters and symbols with functional ink, the forgery prevention effect is higher than that of a configuration in which all of the plurality of minute characters are formed with functional ink. However, there is a problem that an unintended density difference occurs in a pattern visually recognized under a predetermined observation condition due to the information represented by each of the minute characters. Specifically, the character "本" with a larger printing area on the substrate is visually recognized darker than the character "日". As a result, when using characters and symbols with extremely different printing areas, there is a problem that it will affect the pattern visually recognized under a predetermined observation condition. To avoid this, characters and symbols with similar printing areas can be selected for printing. However, in that case, there is a problem that the characters and symbols constituting the minute character group are restricted.

[0009] In addition, in the technology of Patent Document 2, due to the difference in area of the halftone graphic units, a pattern expressing continuous gradation is visually recognized under visible light and infrared light. However, the resolution and gradation expressed by the pattern with continuous gradation are dependent on the halftone graphic. Specifically, although an example of adjusting the line area ratio for each pattern of "太陽" is disclosed as the halftone graphic of Patent Document 2, the density difference between the center and the edge of the "太陽" pattern affects the pattern visually observed under visible light, and there is a problem that an unintended part is expressed faintly or, conversely, a part is expressed darkly in the pattern visually observed under visible light.

[0010] In addition, the technology of Patent Document 2 can express the density of the pattern visually recognized under visible light by arranging the areas of the first figures (halftones) composed of ink not containing an infrared absorption dye to be different. However, since the first figure constituting the halftone image is only composed of the pattern of "太陽", when observed enlarged as in Patent Document 1, a plurality of information cannot be visually recognized. Even if the first figure is made into different patterns, Patent Document 2 does not disclose how to specifically form the pattern visually recognized under visible light and the pattern visually recognized under infrared light.

[0011] The present invention aims to solve the above-mentioned problems, and provides a printed matter in which the printed pattern is composed of a collection of letters and symbols, and the authenticity of which can be determined using infrared absorption characteristics, fluorescent emission characteristics, etc., in which the pattern visible when the printed pattern is observed under visible light is expressed in high resolution, and even if the patterns of letters, symbols, etc. that make up the printed pattern are configured to represent different information, the pattern that makes up the latent image is concealed without affecting the pattern visible under visible light, making it possible to determine the authenticity of the printed matter. [Means for solving the problem]

[0012] The authenticity-determinable printed matter of the present invention has a printed pattern in which multiple information patterns, each consisting of information represented by lines, are arranged on at least a portion of a substrate, and the printed pattern is divided into a first image portion and a common image portion that constitute first significant information visible under visible light, and a second image portion and a background portion that form the background of the first significant information, by partially varying the area ratio of the information pattern; the information pattern that constitutes the first image portion and background portion is made of a first printed layer made of a material of a different color than the substrate, and the information pattern that constitutes the common image portion and second image portion is made of a second printed layer that is the same color as the first printed layer and is made of a material containing a functional material that is visible under specified viewing conditions, and the first printed layer is stacked or juxtaposed with the second printed layer, and the second significant information that is visible under specified viewing conditions is formed by the second printed layer.

[0013] In addition, the authenticity-determinable printed matter of the present invention is characterized in that at least one of the information patterns placed in each of the first image area, common area, second image area, and background area represents different information, and the information patterns are formed with the same area ratio in each area.

[0014] In addition, the authenticity-distinguishing printed matter of the present invention is characterized in that the first printed layer is formed in black by mixing cyan, magenta, and yellow inks, and the second printed layer is formed from black ink having infrared absorption properties.

[0015] Furthermore, the method for creating image data for prints whose authenticity can be discriminated is a method for creating image data for producing prints whose authenticity can be discriminated as described above, and includes a base image setting step of setting a first base image including an image that is the basis of first significant information visible under visible light and a second base image that is the basis of second significant information visible under predetermined observation conditions to the same image size; a first density correction process of converting the first base image into a first density-corrected image by applying a first tone curve for compressing the first base image into a shadow-side gradation; and a second density correction process of compressing the second base image into a highlight-side gradation that is equal to or lower than the minimum density of the first density-corrected image and converting it into a second density-corrected image. The method is characterized by comprising an information pattern image generation process for generating an information pattern image by arranging a plurality of third original images, which are the basis for an information pattern in which information is expressed by lines, within an image area of ​​the same size as the first density-corrected image and the second density-corrected image, and an image data generation process comprising a process for generating first printing layer image data by adjusting and converting the line width of the third original image in accordance with the density of an image in the same positional relationship as the first density-corrected image in the third original image constituting the information pattern image, and a process for generating second printing layer image data by adjusting and converting the line width of the third original image in accordance with the density of an image in the same positional relationship as the second density-corrected image. [Effects of the Invention]

[0016] The authenticity-determinable printed matter of the present invention is a printed matter in which a printed pattern is formed by a collection of letters and symbols, and a pattern for determining authenticity can be seen under specified observation conditions, and the design visible when the printed pattern is observed under visible light can be expressed in high resolution.

[0017] Furthermore, in the authenticity-determinable printed matter of the present invention, even if the patterns of letters, symbols, etc. that make up the printed pattern are configured to express different information, the patterns that make up the latent image can be concealed without affecting the design that is visible under visible light.

[0018] Furthermore, according to the method of the present invention for creating image data for printed matter that can be authenticated, a printed pattern is formed by a collection of letters and symbols, and image data for printed matter in which the pattern for authenticity can be visually recognized under specified observation conditions can be easily created. [Brief explanation of the drawings]

[0019] [Figure 1] 1A and 1B are diagrams showing the structure of a printed matter that can be authenticated in the present invention. [Figure 2] 1 is a diagram showing the configuration of a print pattern according to the present invention; [Figure 3] FIG. 10 is a diagram showing the configuration of a background portion that constitutes a printed pattern. [Figure 4] FIG. 2 is a diagram showing the configuration of a first image portion that constitutes a print pattern. [Figure 5] FIG. 10 is a diagram showing the configuration of a second image portion that constitutes a print pattern. [Figure 6] 10 is a diagram showing the configuration of an information pattern formed in a second image portion. FIG. [Figure 7] FIG. 10 is a diagram showing another configuration of the information pattern formed in the second image portion. [Figure 8] 10A and 10B are diagrams illustrating the configuration of a common image portion that constitutes a print pattern. [Figure 9] FIG. 10 is a diagram showing the configuration of the boundary portion between the first image portion and the background portion. [Figure 10] 10A and 10B are diagrams showing the configuration of information patterns formed in each part of a printed pattern. [Figure 11] 10A and 10B are diagrams showing the patterns of the printed pattern as viewed under diffuse reflected light and infrared light. [Figure 12] FIG. 10 is a diagram showing the configuration of a print pattern in which the second significant information is a gradation image. [Figure 13] FIG. 10 is a diagram showing the configuration of a print pattern in which the first significant information is a gradation image. [Figure 14] 10 is an enlarged view showing the boundary of a shaded area in the design of the first significant information. FIG. [Figure 15] FIG. 10 is a diagram showing an information pattern configured to show different characters. [Figure 16] FIG. 10 is a diagram showing another example of an information pattern. [Figure 17] FIG. 1 illustrates the configuration of camouflage elements that conceal information patterns. [Figure 18] FIG. 1 is a block diagram showing an apparatus for creating image data for prints that can be authenticated; [Figure 19] FIG. 10 is a flowchart showing a method for creating image data for prints that can be authenticated. [Figure 20] FIG. 10 is a diagram showing a base image set in a base image setting step. [Figure 21] FIG. 10 is a diagram showing a first density-corrected image generated by the first density correction processing. [Figure 22] FIG. 10 is a diagram showing a second density-corrected image generated by the second density correction process. [Figure 23] 10A and 10B are diagrams showing information pattern images generated by an information pattern image generating step. [Figure 24] FIG. 10 is a diagram showing image data generated by a process for generating image data for a first printing layer. [Figure 25] 10A and 10B are diagrams illustrating a process for generating image data for a first printing layer. [Figure 26] 10A and 10B are diagrams illustrating a process of generating image data for a first printing layer in a partial area of ​​an information pattern image. [Figure 27] 10 is an example of image data for a first printing layer. [Figure 28] 10 is an example of first print layer image data converted according to a first density correction image. [Figure 29] 10 is another example of image data for the first printing layer converted according to the first density correction image. [Figure 30] FIG. 10 is a diagram illustrating a process of generating image data for a first printing layer in another partial region of the information pattern image. [Figure 31] FIG. 10 is another diagram illustrating the process of generating image data for the first printing layer. [Figure 32]FIG. 10 is a diagram showing image data generated by a process for generating image data for a second printing layer. [Figure 33] FIG. 10 is a diagram showing an information pattern image in which different characters are arranged. DETAILED DESCRIPTION OF THE INVENTION

[0020] The following description will discuss embodiments of the present invention with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below, and various other embodiments are also encompassed within the scope of the technical concept set forth in the claims.

[0021] (First embodiment) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 shows a printed matter (hereinafter referred to as "printed matter (1)") that can be authenticated in accordance with the present invention.

[0022] The printed matter (1) has a printed pattern (3) on a substrate (2) in a color different from that of the substrate (2). The substrate (2) used in the present invention may be any material capable of forming the printed pattern (3), such as paper materials such as fine paper and coated paper, or films, plastic plates, etc., and is not limited in terms of material, external shape, dimensions, color, etc. A flat surface of the substrate (2) is preferable because the printed pattern (3) can be processed using a general printing machine, but the printed pattern (3) can also be processed on a substrate (2) with a curved surface. Furthermore, the printed matter (1) shown in FIG. 1 is an example in which the printed pattern (3) is formed on only a portion of the substrate (2), but the printed pattern (3) may be formed on the entire substrate (2).

[0023] The "star" design shown in the printed pattern (3) in FIG. 1 is an example of first significant information that is visible when the printed pattern (3) is observed under diffuse reflected light, and the "moon" design is an example of second significant information that is visible when the printed pattern (3) is observed under predetermined observation conditions, such as infrared light or ultraviolet light. The second significant information is visible under, for example, infrared light or ultraviolet light, and can be used as a means for determining the authenticity of the printed matter (1). Note that in the present invention, the designs represented by the first significant information and the second significant information are not limited to these and may be letters, symbols, other designs, or multi-tone images such as people or landscapes. Note that the predetermined observation conditions under which the second significant information can be visible will be described in detail below.

[0024] In the present invention, the printed pattern (3) is composed of a plurality of information patterns (3A), as shown in the enlarged view of Figure 1, and the information patterns (3A) are colored with a material of a different color from the substrate (2), and desired information such as letters, symbols, figures, etc. are composed of lines. In the present invention, the information represented by the information patterns (3A) is not particularly limited, but here, an example will be described in which the information pattern (3A) represents the letter "A." Furthermore, in the present invention, the plurality of information patterns (3A) may be configured to represent different letters or symbols, but here, an example will be described in which they all represent the same letter "A."

[0025] In the present invention, the size of the information pattern (3A) is not particularly limited, but it is preferable that the width (size in the first direction) or height (size in the second direction) is 500 μm or more so that characters, symbols, etc. can be visually confirmed when formed as a printed pattern (3) on security printed matter such as banknotes or passports. It may also be 500 μm or less so that it can be observed by magnifying it with a magnifying glass or the like. On the other hand, if the size of the information pattern (3A) is large, the resolution of the design visible from the printed pattern (3) decreases, so it is preferable that it be 3 mm or less.

[0026] As shown in the enlarged view of FIG. 1, multiple information patterns (3A) constituting the printed pattern (3) are arranged in different directions (V1, V2). In this embodiment, as shown in the enlarged view of FIG. 1, the information patterns (3A) are arranged in the left-right and up-down directions at a predetermined pitch (P1, P2). However, they may be arranged diagonally (not shown), or in two different directions. Furthermore, the pitches (P1) and (P2) of the information patterns (3A) may be the same or different. The pitches (P1, P2) of the information patterns (3A) are not particularly limited, but a large pitch (P1, P2) reduces the resolution of the design visible from the printed pattern (3), so it is preferable that the pitch be no more than twice the size of the information patterns. Furthermore, when formed as a printed pattern (3) on security printed matter such as banknotes or passports, it is preferable that the distance between information patterns (3A) (the difference between the pitch and the size of the information elements) be 1 mm or less so as not to reduce the resolution of the image visible from the printed pattern (3).

[0027] In the present invention, the printed pattern (3) is composed of a plurality of information patterns (3A) colored in a color different from that of the base material (2), but the area of ​​the printed pattern (3) where the "star" design, which is the first significant information, is visible and the area where the "moon" design, which is the second significant information, is visible have different configurations of the information patterns (3A). Details of the printed pattern (3) will be described below.

[0028] (Each part) 2(a) to 2(d) are diagrams illustrating, in an exploded manner, the area in the printed pattern (3) where the "star" design, which is the first significant information, is visible and the area in which the "moon" design, which is the second significant information, is visible. Hereinafter, the various parts constituting the printed pattern (3) will be described as follows: the area that forms the background for the first significant information (the "star" design) and the second significant information (the "moon" design) shown in FIG. 2(a) is referred to as the background area (3-1); the area showing part of the first significant information shown in FIG. 2(b) is referred to as the first image area (3-2); the area showing part of the second significant information shown in FIG. 2(c) is referred to as the second image area (3-3); and the common image area (3-4) showing both the first significant information and the second significant information shown in FIG. 2(d) is referred to as the common image area (3-4).

[0029] In addition, the information pattern constituting the background portion (3-1) will be described as symbol "3A1", the information pattern constituting the first image portion (3-2) as symbol "3A2", the information pattern constituting the second image portion as symbol "3A3", and the information pattern constituting the common image portion (3-4) as symbol "3A4".

[0030] Furthermore, as shown in Figure 2(e), the printed matter (1) of the present invention has an information pattern (3A) formed across the boundary between the light and dark shades of the design visible under visible light (here, the boundary between the "star" design and its background), and in order to express the design visible under visible light with high resolution, the information pattern (3A) has different line widths at the boundary between the design area visible under visible light and the background area. The information pattern formed at the boundary will be described using the symbol "3A5."

[0031] (background part) Figure 3 is a diagram showing the configuration of the background portion (3-1), and the information pattern (3A1) that constitutes the background portion (3-1) is formed by a printed layer (hereinafter referred to as the "first printed layer (4A)") made of a material of a different color from the base material (2).

[0032] The image width (W1) of the information pattern (3A1) shown in the enlarged view of Figure 3 is the same throughout the entire letter "A," and the image width (W1) is the same for multiple information patterns (3A1). In the present invention, the material for forming the first printed layer (4A) is not particularly limited as long as it is a color different from that of the substrate (2), and commercially available ordinary inks can be used. Note that the printing method for forming the first printed layer (4A) can be any printing method, such as offset printing, flexographic printing, letterpress printing, gravure printing, screen printing, intaglio printing, or inkjet printing.

[0033] In this embodiment, an example will be described in which the first printed layer (4A) is formed with black ink made by mixing cyan ink, magenta ink, and yellow ink. In this case, the first printed layer (4A) formed in the background portion (3-1) is formed corresponding to the letter "A" appearing in the information pattern (3A1), and the area of ​​the letter "A" is filled with black ink made by mixing cyan ink, magenta ink, and yellow ink.

[0034] (First image section) Figure 4 is a diagram showing the configuration of the first image section (3-2), and the information pattern (3A2) that constitutes the first image section (3-2) has a first printing layer (4A) formed of the same material as the material that forms the background section (3-1) (in this embodiment, a black ink mixed with cyan ink, magenta ink, and yellow ink).

[0035] The image width (W2) of the information pattern (3A2) shown in the enlarged view of Figure 4 is the same throughout the entire character "A," and the image width (W2) is the same for multiple information patterns (3A2). The information pattern (3A2) formed in the first image portion (3-2) and the information pattern (3A1) formed in the background portion (3-1) have different area ratios. In the present invention, the area ratio refers to the proportion of the area colored with a material of a different color from the base material (2) within a certain area of ​​the base material (2).

[0036] 4 shows a configuration in which the area ratio of the information pattern (3A2) formed in the first image portion (3-2) is higher than the area ratio of the information pattern (3A1) formed in the background portion (3-1), specifically, the image width (W2) of the information pattern (3A2) formed in the first image portion (3-2) is larger than the image width (W1) of the information pattern (3A1) formed in the background portion (3-1). As a result, the first image portion (3-2) with a high area ratio is perceived as a darker color when observed under diffuse reflected light, and in this case, the first image portion (3-2) representing the "star" design is perceived as a darker color than the background portion (3-1).

[0037] Here, an example has been described in which the line width (W2) of the information pattern (3A2) formed in the first image portion (3-2) is larger than the line width (W1) of the information pattern (3A1) formed in the background portion (3-1). However, the line width (W2) of the information pattern (3A2) formed in the first image portion (3-2) may be smaller than the line width (W1) of the information pattern (3A1) formed in the background portion (3-1), and in this case, the first image portion (3-2) representing the "star" design is perceived as being a lighter color than the background portion (3-1).

[0038] (Second image section) Figure 5 is a diagram showing the configuration of the second image section (3-3), and the information pattern (3A3) that constitutes the second image section (3-3) is composed of a combination of a first printed layer (4A) made of the same material as the material that forms the background section (3-1) (in this embodiment, a black ink mixed with cyan ink, magenta ink, and yellow ink), and a printed layer (hereinafter referred to as the "second printed layer (5A)") that has functionality that allows it to be seen when observed under specified observation conditions and is made of a material that is the same color as the material that forms the first printed layer (4A) when observed under diffuse reflected light.

[0039] The image width (W3) of the information pattern (3A3) shown in the enlarged view of FIG. 5 is the same throughout the character "A," and the image width (W3) is the same for multiple information patterns (3A3).

[0040] (functionality) In the present invention, examples of functional materials for forming the second printed layer (5A) include fluorescent materials that emit light when irradiated with ultraviolet light. Other examples include glitter pigments such as gold, silver, and aluminum that produce specular reflection under visible light, with the angle of reflection equal to the angle of light incident on the authentic print (1), and pearlescent pigments that produce interference light. Other examples include metal oxides such as titanium oxide, zinc oxide, and iron oxide that absorb ultraviolet light under ultraviolet light, as well as polyurethane resins, polyester resins, and acrylic resins. Other examples include metal oxides such as nickel titanate, nickel tungstate, neodymium oxide, and iron oxide, and carbon black that absorb infrared light under infrared light. In the present invention, the material for forming the second printed layer (5A) is not limited to the above materials, as long as it is visible under specified observation conditions. Ink containing these functional materials can be used as the ink for forming the second printed layer (5A) by appropriately blending pigments and dyes to achieve the same color as the ink for forming the first printed layer (4A).

[0041] In this embodiment, a specific example of a material for forming the second printed layer (5A) containing the above-mentioned functional material is a configuration using black ink containing carbon black. Below, a first combination of the first printed layer (4A) and the second printed layer (5A) constituting the information pattern (3A3) of the second image section (3-3) of the present invention will be described with reference to Figure 6.

[0042] Fig. 6(a) is a diagram showing the arrangement of the first printed layer (4A) and the second printed layer (5A), and Fig. 6(b) is a cross-sectional view taken along line A-A' in Fig. 6(a). In the configuration shown in Fig. 6, the information pattern (3A3) is formed by laminating the second printed layer (5A) on a part of the first printed layer (4A).

[0043] Furthermore, the first printed layer (4A) and the second printed layer (5A) are the same color, and the first printed layer (4A) is configured to display the letter "A" represented by the information pattern (3A3). With this configuration, even if the second printed layer (5A) is laminated on part of the first printed layer (4A), since they are the same color, when observed under diffuse reflected light, the second printed layer (5A) cannot be seen as a single layer, but can be seen as the information pattern (3A3) of the letter "A" formed by the first printed layer (4A).

[0044] In the first combination, the second printed layer (5A) also represents the letter "A" in FIG. 6(a), but it need only be laminated on a portion of the first printed layer (4A), and is not limited to the configuration shown in FIG. 6(a). Another configuration in which the second printed layer (5A) is laminated on a portion of the first printed layer (4A) will be described later. The stacking order of the first printed layer (4A) and the second printed layer (5A) may be different from that shown in FIG. 6(b), with the first printed layer (4A) laminated on top of the second printed layer (5A). The colors of the first printed layer (4A) and the second printed layer (5A) are preferably dark, navy blue or black in this embodiment, so that the boundary of the second printed layer (5A) is less noticeable when the first printed layer (4A) and the second printed layer (5A) of the same color are laminated.

[0045] Next, a second combination of the first printed layer (4A) and the second printed layer (5A) constituting the information pattern (3A3) of the present invention will be described with reference to FIG.

[0046] Figure 7(a) is a diagram showing the arrangement of the first printed layer (4A) and the second printed layer (5A), and Figure 7(b) is a cross-sectional view taken along line A-A' in Figure 7(a). In the configuration shown in Figure 7, the information pattern (3A3) is formed by juxtaposing the first printed layer (4A) and the second printed layer (5A), and the letter "A" is formed by combining the patterns of the first printed layer (4A) and the second printed layer (5A).

[0047] In Figure 7, the second printed layer (5A) is arranged inside the pattern made by the first printed layer (4A), like a tweezers arrangement, but the arrangement of the first printed layer (4A) and the second printed layer (5A) is not limited to this, as long as the two printed layers (4A, 5A) are configured to represent the letter "A." Furthermore, the first printed layer (4A) and the second printed layer (5A) are the same color, and when observed under diffuse reflected light, the boundary between them is not visible, and they can be seen as the information pattern (3A3) of the letter "A."

[0048] In the second combination, in Figure 7(a), the second printed layer (5A) represents the letter "A", but this is not limited to this, and it is sufficient that the information pattern (3A3) represents a specified letter, symbol, or figure when combined with the first printed layer (5A).

[0049] In the present invention, when observed under diffuse reflected light, the second image portion (3-3) has the same color as the background portion (3-1) and is visible as the background of the "star" design, so the area ratio of the information pattern (3A3) formed in the second image portion (3-3) and the information pattern (3A1) formed in the background portion (3-1) are configured to be equal. Specifically, the image width (W3) of the information pattern (3A3) formed in the second image portion (3-3) is configured to be the same as the image width (W1) of the information pattern (3A1) formed in the background portion (3-1).

[0050] In the present invention, the area ratio of the second printed layer (5A) constituting the information pattern (3A3) can be changed depending on the second significant information visible when observed under predetermined observation conditions. Here, an example is described in which the second printed layer (5A) represents the letter "A" in all of the multiple information patterns (3A3) constituting the second image portion (3-3) and is formed with the same area ratio. However, by varying the area ratio of the second printed layer (5A), the second significant information visible when observed under predetermined observation conditions can be expressed as a gradation image. This configuration will be described later.

[0051] (Common image section) Figure 8 is a diagram showing the configuration of the common image area (3-4). In this embodiment, the information pattern (3A4) constituting the common image area (3-4) is, like the second image area (3-3), a combination of a first printed layer (4A) made of black ink mixed with cyan ink, magenta ink, and yellow ink, and a second printed layer (5A) made of black ink containing carbon black, and is configured such that the second printed layer (5A) is laminated on part of the first printed layer (4A) or the first printed layer (4A) and the second printed layer (5A) are juxtaposed.

[0052] Furthermore, the image width (W4) of the information pattern (3A4) shown in the enlarged view of Figure 8 is the same throughout the character "A," and the image width (W4) is the same across multiple information patterns (3A4).

[0053] When observed under diffuse reflected light, the common image area (3-4) appears in the same color as the first image area (3-2) and is seen as a "star" pattern, so the image width (W4) of the information pattern (3A4) formed in the common image area (3-4) is equal to the image width (W2) of the information pattern (3A2) formed in the first image area (3-2).

[0054] In the present invention, the area ratio of the second printed layer (5A) constituting the information pattern (3A4) may also be changed depending on the second significant information visible when observed under predetermined observation conditions. By varying the area ratio of the second printed layer (5A) in conjunction with the information pattern (3A3) formed in the second image area (3-3), the second significant information visible when observed under predetermined observation conditions can be expressed as a gradation image. Here, an example will be described in which the second printed layer (5A) represents the letter "A" in all of the multiple information patterns (3A4) constituting the common image area (3-4), and is all formed with the same area ratio, which is the same as the second printed layer (5A) formed in the information pattern (3A3) of the second image area (3-3).

[0055] (boundary) Figure 9 is a diagram showing the configuration of the information pattern (3A5) formed at the boundary between the area where the "star" pattern is visible and the background area, and as an example, it shows the configuration of the boundary area between the background area (3-1) and the first image area (3-2).

[0056] As shown in the enlarged view of FIG. 9 , the information pattern (3A5) formed at the boundary between the area where the "star" design is visible and its background area has different line widths for the letter "A" in one information pattern (3A5), with the line width (W1) of a portion of the letter "A" in the background area (3-1) being smaller than the line width (W2) of the letter "A" in the first image area (3-2). As shown in FIG. 9 , the printed matter (1) of the present invention can express the boundary of the "star" design in detail by varying the line widths in one information pattern (3A5). Here, the configuration of the information pattern (3A5) formed at the boundary between the background area (3-1) and the first image area (3-2) has been described. However, at the boundary between the second image area (3-3) and the common image area (3-4), the line widths of one information pattern (3A5) are different depending on the area where the "star" design is visible and its background area.

[0057] Figure 10 is a diagram showing the configuration of each part that makes up the printed pattern (3) described above and the information pattern (3A).For the second image part (3-3) and the common image part (3-4), the effect of the printed matter (1) of this embodiment will be explained using an example of a configuration in which a second printing layer (5A) is laminated on a part of the first printing layer (4A).

[0058] In this embodiment, the information pattern (3A1) of the background portion (3-1) is formed using black ink made by mixing cyan ink, magenta ink, and yellow ink, as shown in Figure 10(a), and the first image portion (3-2) also has an information pattern (3A2) made of the same material.

[0059] In this case, as shown in Figure 10(b), the line width (W2) of the information pattern (3A2) formed in the first image portion (3-2) is larger than the line width (W1) of the information pattern (3A1) formed in the background portion (3-1), so that the first image portion (3-2) is perceived as being darker in color than the background portion (3-1).

[0060] 10(c), the second image portion (3-3) is formed of a first printed layer (4A) made of a black ink that is a mixture of cyan ink, magenta ink, and yellow ink, and a second printed layer (5A) made of a black ink containing carbon black, but because they are all black, the boundary between them cannot be seen under diffuse reflected light. Furthermore, because the image width (W3) of the information pattern (3A3) formed in the second image portion (3-3) is equal to the image width (W1) of the information pattern (3A1) formed in the background portion (3-1), it is seen as the same color as the background portion (3-1) under diffuse reflected light.

[0061] 10(d), the common image area (3-4) is formed of a first printed layer (4A) made of a black ink that is a mixture of cyan ink, magenta ink, and yellow ink, and a second printed layer (5A) made of a black ink containing carbon black, but because they are all black, the boundary between them cannot be seen under diffuse reflected light. Furthermore, because the image width (W4) of the information pattern (3A4) of the common image area (3-4) is equal to the image width (W2) of the information pattern (3A2) of the first image area (3-2), it is seen as the same color as the first image area (3-2) under diffuse reflected light.

[0062] As a result of the above, when the printed pattern (3) is observed under diffuse reflected light, as shown in Figure 11(a), the "star" design represented by the first image portion (3-2) and the common image portion (3-4) is perceived as being darker than the background of the "star" design represented by the background portion (3-1) and the second image portion (3-3). Furthermore, as described above, the printed pattern (3) of the present invention is configured such that the line width of one information pattern (3A5) differs depending on the area in which the first significant information (in this embodiment, the "star" design) is perceived and its background area, thereby enabling the design of the first significant information to be expressed in detail. Furthermore, as shown in the enlarged view of Figure 11(a), the letter "A" can be perceived throughout the entire printed pattern (3).

[0063] Next, when the printed pattern (3) is irradiated with infrared light and observed with an infrared camera, the first printed layer (4A), which is made of a black ink mixture of cyan, magenta, and yellow inks as shown in Figure 10, transmits infrared light and cannot be seen by the infrared camera. On the other hand, the second printed layer (5A), which is made of a black ink containing carbon black, absorbs infrared light and appears dark to the infrared camera. As shown in Figure 11(b), the "moon" pattern represented by the second image area (3-3) and the common image area (3-4) can be seen. In this embodiment, since the area ratio of the second printed layer (5A) formed in the second image area (3-3) and the common image area (3-4) is the same, the "moon" pattern can be seen with a uniform density, as shown in Figure 11(b). In addition, in this embodiment, as shown in the enlarged view of FIG. 11(b), when observed with an infrared camera, the letter "A" appearing in the second printed layer (5A) can be seen.

[0064] In this embodiment, an example has been described in which a black ink made by mixing cyan ink, magenta ink, and yellow ink, and a black ink containing carbon black are used as the material for forming the first printed layer (4A) and the material for forming the second printed layer (5A). These inks are generally used as process inks and are inexpensive, and are preferable because they can be used directly to produce the printed matter (1) using a general laser printer or inkjet printer.

[0065] In this embodiment, an example has been described in which the area ratio of the second printing layer (5A) formed in the second image area (3-3) and the common image area (3-4) is the same, thereby making the second significant information visible with a uniform density. However, by partially differentiating the area ratio of the second printing layer (5A) formed in the second image area (3-3) and the common image area (3-4), the second significant information can be expressed as a gradation image, and an example of this will be described using Figure 12.

[0066] Figure 12(a) shows the second significant information in a "moon" design, with the density gradually increasing from top to bottom. As mentioned above, the second significant information is represented by the second image portion (3-3) and the common image portion (3-4), and the area ratio of the second printing layer (5A) constituting the information pattern (3A3) of the second image portion (3-3) and the information pattern (3A4) of the common image portion (3-4) differs depending on the density of each portion shown in Figure 12(a).

[0067] Specifically, Figure 12(b) is an enlarged view of the area surrounded by a thick line in the second image portion (3-3) shown in Figure 12(a). Here, an example of an information pattern (3A3) configured by stacking a first printed layer (4A) and a second printed layer (5A) is described. As shown in the enlarged view of Figure 12(b), the area ratio of the second printed layer (5A) varies among the multiple information patterns (3A3), increasing from top to bottom. Figure 12(b) illustrates a configuration in which the length of the second printed layer (5A) formed along a portion of the letter "A" gradually increases, but a configuration in which the width increases may also be used (not shown). Furthermore, multiple second printed layers (5A) may be provided within the area of ​​the information pattern (3A3) to vary their area ratios (not shown).

[0068] FIG. 12(c) is an enlarged view of the area surrounded by a dotted line in the common image area (3-4) shown in FIG. 12(a). Here, an example of an information pattern (3A4) configured by laminating a first printed layer (4A) and a second printed layer (5A) will be described. As shown in the enlarged view of FIG. 12(c), the area ratio of the second printed layer (5A) varies among the multiple information patterns (3A4), with the area ratio of the second printed layer (5A) increasing from top to bottom. In the "moon" design shown in FIG. 12(a), the common image area (3-4) in the area surrounded by a dotted line has a higher area ratio of the second printed layer (5A) than the second image area (3-3) surrounded by a thick line, corresponding to the second significant information configured to gradually increase in density from top to bottom.

[0069] FIG. 12(d) is an enlarged view of the area surrounded by a dashed line in the second image portion (3-3) shown in FIG. 12(a). Here, an example of an information pattern (3A3) configured by laminating a first printed layer (4A) and a second printed layer (5A) will be described. As shown in the enlarged view of FIG. 12(d), the area ratio of the second printed layer (5A) varies among the multiple information patterns (3A3), with the area ratio of the second printed layer (5A) increasing from top to bottom. In the "moon" design shown in FIG. 12(a), the area ratio of the second printed layer (5A) in the second image portion (3-3) surrounded by a dashed line is higher than that of the common image portion (3-4) surrounded by a dotted line, corresponding to the second significant information configured to gradually increase in density from top to bottom.

[0070] In the present invention, when forming the second significant information with gradation, it is necessary to provide the second printed layer (5A) within the information pattern (3A) with the smallest area among the information patterns (3A) constituting the print pattern (3) so as not to affect the first significant information visible under diffuse reflected light. For example, among the information patterns (3A1, 3A2, 3A3, 3A4) of each part shown in Figure 10, the information pattern (3A1) in the background part (3-1) and the information pattern (3A3) in the second image part (3-3) have the smallest areas, and among these, in the second image part (3-3) where the second printed layer (5A) is formed, the area of ​​the second printed layer (5A) can be arbitrarily varied within the range of the information pattern (3A3). In the common image portion (3-4), the area of ​​the second print layer (5A) can be made different within a range equivalent to the area of ​​the information pattern (3A3) in the area of ​​the information pattern (3A4).

[0071] In Figure 12, the second significant information is described as having a configuration in which the density gradually increases from top to bottom in the ``moon'' design, but in the present invention, the area ratio of the second printing layer (5A) formed within the areas of the information patterns (3A3, 3A4) of the second image portion (3-3) and the common image portion (3-4) can be made different depending on the desired gradation of the second significant information.

[0072] The information patterns (3A3, 3A4) shown in Figures 12(c) and 12(d) are examples of a configuration in which a first printed layer (4A) and a second printed layer (5A) are stacked, but as explained in paragraph (0037) and Figure 7, the first printed layer (4A) and the second printed layer (5A) may also be arranged side by side, and if the second significant information is to be a gradation image, the area ratio of the first printed layer (4A) and the second printed layer (5A) formed in the information patterns (3A3, 3A4) can be adjusted.

[0073] In Figure 12, an example was explained in which the area ratio of the second printing layer (5A) is adjusted when the second significant information is a gradation image. However, in the present invention, the reproducibility of the second significant information can be improved by forming information patterns (3A3, 3A4) at the boundary between the second significant information (here, a "moon" pattern) and its background, and providing the second printing layer (5A) according to the boundary of the second significant information.

[0074] In this embodiment, an example has been described in which the first significant information of a "star" pattern is visible with uniform density when observed under diffuse reflected light, but the printed matter (1) of the present invention can express the first significant information visible under diffuse reflected light as a gradation image, and a specific configuration will be described using Figure 13.

[0075] Figure 13(a) shows the first significant information in a "star" pattern, with the density gradually increasing from top to bottom. As mentioned above, the first significant information is represented by the first image portion (3-2) and the common image portion (3-4), and the image widths (W2, W4) of the information pattern (3A2) formed in the first image portion (3-2) and the information pattern (3A4) formed in the common image portion (3-4) are different depending on the density of each portion shown in Figure 13(a).

[0076] Specifically, Fig. 13(b) is an enlarged view of the area surrounded by a thick line in the first image portion (3-2) shown in Fig. 13(a). In response to the fact that the first significant information of the "star" design shown in Fig. 13(a) gradually becomes denser from top to bottom, the image width (W2) of the information pattern (3A2) formed in the first image portion (3-2) varies as shown in Fig. 13(b), and the information pattern (3A2) shown in Fig. 13(b) has an image width (W2) that increases from top to bottom.

[0077] Also, Figure 13(c) is an enlarged view of the area surrounded by the dotted line in the common image section (3-4) shown in Figure 13(a). Here, an example of an information pattern (3A4) configured by laminating a first printed layer (4A) and a second printed layer (5A) will be described. Note that in the information pattern (3A4) configured by laminating a first printed layer (4A) and a second printed layer (5A), the second printed layer (5A) is the same color as the first printed layer (4A), and the letter "A" is essentially expressed by the first printed layer (4A). Therefore, in Figure 13(c), only the first printed layer (4A) is shown.

[0078] As shown in the enlarged view of Fig. 13(c), the common image portion (3-4) also has a different image width (W4) of the information pattern (3A4), which increases from top to bottom in correspondence with the first significant information of the "star" design that gradually becomes denser from top to bottom. Also, in the "star" design shown in Fig. 13(a), the common image portion (3-4) in the area surrounded by the dotted line has a larger image width (W4) of the information pattern (3A4) than the first image portion (3-2) surrounded by the thick line, in correspondence with the first significant information that gradually becomes denser from top to bottom.

[0079] Figure 13(d) is an enlarged view of the area surrounded by a dashed line in the first image portion (3-2) shown in Figure 13(a). As shown in the enlarged view of Figure 13(d), in the first image portion (3-2) in the area surrounded by a dashed line, the image width (W2) of the information pattern (3A2) also increases from top to bottom in the first image portion (3-2) in the area surrounded by a dashed line. In the "moon" design shown in Figure 13(a), the area ratio of the information pattern (3A2) is larger in the first image portion (3-2) in the area surrounded by a dashed line than in the common image portion (3-4) surrounded by a dotted line, corresponding to the first significant information whose density gradually increases from top to bottom.

[0080] In this way, by differentiating the area ratios of the information pattern (3A2) formed in the first image portion (3-2) and the information pattern (3A4) formed in the common image portion (3-4), areas in the print pattern (3) with a relatively high area ratio of the information pattern (3A) are perceived as dark colors, and areas with a relatively low area ratio are perceived as light colors, thereby enabling the first significant information to be expressed in gradations. In Figure 13, the first significant information in the "star" design is described as having a gradually darker density from top to bottom, but in the present invention, the area ratios of the information pattern (3A) formed in the first image portion (3-2) and the common image portion (3-4) may be made different depending on the desired gradation of the first significant information.

[0081] Here, we have described a configuration in which the information pattern (3A4) shown in Figure 13(c) is formed by stacking a first printed layer (4A) and a second printed layer (5A).However, in a configuration in which the first printed layer (4A) and the second printed layer (5A) are arranged side by side, a similar effect can be obtained by coloring the information pattern (3A4) shown in Figure 12(c) using the first printed layer (4A) and the second printed layer (5A) (not shown).

[0082] In Figure 13, an example is described in which the line widths (W2, W4) are different for each information pattern (3A2, 3A4), but in the present invention, the line width may be different within one information pattern (3A) depending on the shade of the first significant information that is visible when observed under diffuse reflected light.

[0083] 14(a) is an enlarged view of the boundary portion of the shading area in the design of the first significant information visible when observed under diffuse reflection light, where the left area (E1) corresponds to the dark area and the right area (E2) corresponds to the light area. In this example, the information pattern (3A6) arranged at the boundary portion of the shading area has different stroke widths of the letter "A" within one information pattern (3A6), with the stroke width of part of the information pattern (3A6) on the left side of the shading boundary shown in FIG. 14(a) being large, and the stroke width of the remaining part of the information pattern (3A6) on the right side of the shading boundary being small.

[0084] 14(b) shows a configuration in which the line width of the information pattern (3A6) is partially varied in accordance with the four regions (E1 to E4) of different densities in a portion of the first significant information visible when observed under diffuse reflected light. By partially varying the line width of the information pattern (3A6) in accordance with the densities of the first significant information, the reproducibility of the image visible when observed under visible light can be improved. In the information pattern (3A6) shown in FIG. 14, when the second printed layer (5A) is formed, the pattern corresponds to the common image area (3-4), and when the information pattern (3A6) is formed using only the first printed layer (4A), the pattern corresponds to the first image area (3-2).

[0085] Next, we will explain the configuration of the information pattern (3A) that constitutes the printed pattern (3) to represent different characters. As shown in Figure 1, the printed pattern (3) has the first significant information as a "star" design and the second significant information as a "moon" design, and we will explain the configuration of the information pattern (3A) formed in each part when each is visually recognized as a design of uniform density.

[0086] Fig. 15(a) is a diagram showing the configuration of the information pattern (3A1) that constitutes the background portion (3-1), and as shown in the enlarged view of Fig. 15(a), the information pattern (3A1) shows an example in which the information pattern (3A1) is made up of the letters "J", "A", "P", "A", and "N". Note that the information pattern (3A1) that represents the letters "JAPAN" is arranged not only in the area shown in the enlarged view of Fig. 15(a), but also repeatedly over the entire background portion (3-1) at predetermined pitches (P1, P2).

[0087] In the enlarged view of Figure 15(a), if the information pattern representing the letter "J" is designated as "3A1-1," the information pattern representing the letter "A" is designated as "3A1-2," the information pattern representing the letter "P" is designated as "3A1-3," the information pattern representing the letter "A" is designated as "3A1-4," and the information pattern representing the letter "N" is designated as "3A1-5," then under diffuse reflected light, they are perceived as a background of uniform density, and therefore the area ratios of each information pattern (3A1-1, 3A1-2, 3A1-3, 3A1-4, 3A1-5) are configured to be equal, that is, although the letters represented by each information pattern (3A1-1, 3A1-2, 3A1-3, 3A1-4, 3A1-5) are different, the areas of each information pattern (3A1-1, 3A1-2, 3A1-3, 3A1-4, 3A1-5) are configured to be equal. For example, if the length of the lines forming the letter "J" is shorter than the length of the lines forming the letter "A," the line width of the letter "J" can be made larger than the line width of the letter "A," and the information patterns (3A) representing different letters can be formed so that they each have the same area. The method for forming different characters so that they each have the same area will be explained later in the method for creating authenticity-determinable image data for printed matter of the present invention.

[0088] Figure 15(b) is a diagram showing the configuration of the information pattern (3A2) that constitutes the first image portion (3-2), and as shown in the enlarged view of Figure 15(b), the information pattern (3A2) shows an example in which the information patterns (3A2) are each made up of the letters "J", "A", "P", "A", and "N". Note that the information pattern (3A2) that represents the letters "JAPAN" is arranged at a predetermined pitch (P1, P2) not only in the area shown in the enlarged view of Figure 15(b) but also throughout the first image portion (3-2).

[0089] In the enlarged view of Figure 15(b), if the information pattern representing the letter "J" is designated as "3A2-1," the information pattern representing the letter "A" is designated as "3A2-2," the information pattern representing the letter "P" is designated as "3A2-3," the information pattern representing the letter "A" is designated as "3A2-4," and the information pattern representing the letter "N" is designated as "3A2-5," then under diffuse reflected light, the "star" design is perceived as having a uniform density, so the area ratio of the first printing layer (4A) that colors each information pattern (3A2-1, 3A2-2, 3A2-3, 3A2-4, 3A2-5) is configured to be equal, i.e., although the shapes of the letters are different, the areas of each information pattern (3A2-1, 3A2-2, 3A2-3, 3A2-4, 3A2-5) are configured to be equal. Furthermore, since the "star" design is visually perceived as being darker than its background, the area ratio of the information pattern (3A2) shown in Figure 15(b) is higher than the area ratio of the information pattern (3A1) shown in Figure 15(a).

[0090] Figure 15(b) shows a configuration in which the area ratios of each information pattern (3A2-1, 3A2-2, 3A2-3, 3A2-4, 3A2-5) formed in the first image portion (3-2) are equal, but the area may be different for each information pattern (3A2) depending on the desired gradation of the first significant information.

[0091] FIG. 15(c) is a diagram showing the configuration of the information pattern (3A3) constituting the second image portion (3-3). As shown in the enlarged view of FIG. 15(c), the information pattern (3A3) shows an example in which the information pattern (3A3) is composed of the letters "J," "A," "P," "A," and "N." Note that the information pattern (3A3) representing the letters "JAPAN" is arranged at a predetermined pitch (P1, P2) not only in the area shown in the enlarged view of FIG. 15(c), but also throughout the entire second image portion (3-3). The information pattern (3A3) constituting the second image portion (3-3) shown in FIG. 15(c) is actually formed by forming a first printed layer (4A) and a second printed layer (5A). However, this description will be omitted here, and the configuration of the information pattern (3A3) visible under diffuse reflected light will be described.

[0092] In the enlarged view of Figure 15(c), if the information pattern representing the letter "J" is designated as "3A3-1," the information pattern representing the letter "A" is designated as "3A3-2," the information pattern representing the letter "P" is designated as "3A3-3," the information pattern representing the letter "A" is designated as "3A3-4," and the information pattern representing the letter "N" is designated as "3A3-5," then under diffused reflected light, the background of the "star" design is perceived as having a uniform density, and the areas of the information patterns (3A3-1, 3A3-2, 3A3-3, 3A3-4, 3A3-5) are equal in area and are equal to the area of ​​the information pattern (3A1) in the background portion (3-1).

[0093] FIG. 15(d) is a diagram showing the configuration of the information pattern (3A4) constituting the common image area (3-4). As shown in the enlarged view of FIG. 15(d), the information pattern (3A4) shows an example in which the information pattern (3A4) is composed of the letters "J," "A," "P," "A," and "N." It should be noted that the information pattern (3A4) representing the letters "JAPAN" is arranged at a predetermined pitch (P1, P2) throughout the entire common image area (3-4), not just in the area shown in the enlarged view of FIG. 15(d). The information pattern (3A4) constituting the common image area (3-4) shown in FIG. 15(d) is actually composed of a first printed layer (4A) and a second printed layer (5A). However, this description will be omitted here, and the configuration of the information pattern (3A4) visible under diffuse reflected light will be described.

[0094] In the enlarged view of Figure 15(d), if the information pattern representing the letter "J" is designated as "3A4-1," the information pattern representing the letter "A" is designated as "3A4-2," the information pattern representing the letter "P" is designated as "3A4-3," the information pattern representing the letter "A" is designated as "3A4-4," and the information pattern representing the letter "N" is designated as "3A4-5," then under diffused reflected light, the "star" design is perceived as having uniform density, and the areas of the information patterns (3A4-1, 3A4-2, 3A4-3, 3A4-4, 3A4-5) are equal in area and are equal to the area of ​​the information pattern (3A2) in the first image portion (3-2).

[0095] Figure 15(d) shows a configuration in which the areas of the information patterns (3A4-1, 3A4-2, 3A4-3, 3A4-4, 3A4-5) of the common image portion (3-4) are equal, but as with the first image portion (3-2), by varying the areas of the information patterns of the common image portion (3-4), the first significant information can be expressed as a gradation image, and the area of ​​each information pattern (3A4) representing different characters can be varied depending on the gradation of the desired first significant information.

[0096] In Figure 15, an example is described in which the information pattern (3A) showing the characters "JAPAN" is repeatedly arranged, but multiple information patterns (3A) showing different characters may also be arranged with each having the same area.

[0097] When forming a printed pattern by arranging multiple small characters representing different information, as in the technology of Patent Document 1, the area of ​​each character may differ, which may result in unintended shading in the printed pattern, but by forming each information pattern (3A1, 3A2, 3A3, 3A4) representing different characters with the same area as shown in Figure 15, it is possible to express the density of each part that makes up the printed pattern (3) as a uniform density, which is preferable. Note that, similar to the configuration in which the line width of the information pattern (3A) is varied depending on the shading of the first significant information as shown in Figure 13, the line width may be varied for each information pattern (3A) representing different information to express the shading of the first significant information.

[0098] When the information pattern (3A) is configured to represent different characters, the size of the direction in which the characters are arranged varies depending on the character represented by the information pattern (3A), and if the characters are arranged at a constant pitch, the resolution of the pattern seen from the printed pattern (3) may decrease. For example, if the number "2" and the number "1" are arranged alternately, the narrow width of the "1" character will result in a gap between the "2" and the "1". In such a case, by arranging the information patterns (3A) so that the spacing between them is constant, it is possible to prevent a decrease in the resolution of the pattern seen from the printed pattern (3).

[0099] In the present embodiment, the information pattern (3A) constituting the print pattern (3) has been described as being configured to represent letters, but as shown in FIG. 16(a), the information pattern (3A) may be configured to represent symbols, or as shown in FIG. 16(b), the information pattern (3A) may be configured to represent figures. Furthermore, as shown in FIG. 16(c), the information pattern (3A) may be configured to represent letters, symbols, and figures. Furthermore, while the information pattern (3A) constituting the background portion (3-1), first image portion (3-2), second image portion (3-3), and common image portion (3-4) shown in FIG. 15 has been described as being configured to represent the letters "JAPAN," the information such as letters, symbols, and figures represented by the information pattern (3A) may be different for each portion (3-1, 3-2, 3-3, 3-4).

[0100] (camouflage pattern) In the present invention, in order to make the information represented by the information pattern (3A) constituting the printed pattern (3) less visible, a camouflage element (6A) made of a material of the same color as the first printed layer (4A) may be provided, as shown in Figure 17.

[0101] As shown in Figure 17, by providing camouflage elements (6A) of the same color as the first printed layer (4A) between the information patterns (3A), it is possible to improve the concealment of the letter "A" when observed from a distance from the printed pattern (3). The printed matter (1) configured as shown in Figure 17 serves as one function for determining authenticity against counterfeits that simply form printed patterns (3) by imitating only the information pattern (3A) of the present invention, and is a form that has excellent anti-counterfeiting effects.

[0102] In addition, in a configuration in which camouflage elements (6A) are provided in the second image area (3-3) and the common image area (3-4), the material (same color as the first printing layer) that forms the second printing layer (5A) can be formed on top of the camouflage elements (6A), or the camouflage elements (6A) can be formed using the material that forms the second printing layer (5A) to fill in the spaces between the information patterns (3A3, 3A4) that comprise the second printing layer (5A), thereby improving the visibility of the second significant information that can be seen when observed under specific observation conditions.

[0103] (Device for creating image data for print that can be authenticated) FIG. 18 is a block diagram showing the configuration of a device (M) for creating authenticity-distinguishable image data for printed matter. The device (M) for creating authenticity-distinguishable image data for printed matter shown in FIG. 18 includes an input unit (M1), an editing unit (M2), a communication interface (M3), a database (M4), and a display unit (M5). Note that the display unit (M5) is not an essential component for creating authenticity-distinguishable image data for printed matter. The printing unit (P) shown in FIG. 18 is a unit for printing a print pattern (3) on a substrate (2) based on data created by the device (M) for creating authenticity-distinguishable image data for printed matter. While not an essential component for creating authenticity-distinguishable image data for printed matter, by configuring the printing unit (P) with a laser printer or inkjet printer (described below) and connecting it to the device (M) for creating authenticity-distinguishable image data for printed matter, it is possible to perform processes from data generation to the creation of authenticity-distinguishable printed matter (1) as a single device.

[0104] (Input means) The input means (M1) is composed of an invisible image input means (M1a), a visible image input means (M1b), a text input means (M1c), and an information input means (M1d). The invisible image input means (M1a) is a means for inputting an image (hereinafter referred to as the "second original image (20)") that serves as the basis for the second significant information visible when observed under predetermined observation conditions. The visible image input means (M1b) is a means for inputting an image (hereinafter referred to as the "first original image (10)") that serves as the basis for the first significant information visible when viewed with the naked eye under visible light. The first original image (10) and the second original image (20) are input by capturing an image with a digital camera, scanning with a scanner, or by reading out images pre-stored in a database (M4) or an external database server connected via a communication interface (M3). The invisible image input means (M1a) or the visible image input means (M1b) may be configured with a mouse, keyboard, etc., and the first base image (10) and the second base image (20) may be created directly using image processing software such as Photoshop (registered trademark), which is image processing software manufactured by Adobe (registered trademark).

[0105] The text input means (M1c) is a means for inputting information on characters and symbols that appear in the information pattern (3A) that constitutes the print pattern (3). The information on characters and symbols that appear in the information pattern (3A) is input by typing on a keyboard or by reading characters and symbols that are pre-stored in the database (M4) or an external database server connected via the communication interface (M3).

[0106] The information input means (M1d) is composed of a mouse, a keyboard, etc., and may be used to input density correction values ​​used in the editing means (M2) and instructions to execute various image processes.

[0107] (Editing method) The editing means (M2) shown in FIG. 18 includes a grayscale conversion means (M2a), a tone curve adjustment means (M2b), a text pattern conversion means (M2c), an image data generation means (M2d), and a synthesis means (M2e).

[0108] The grayscale conversion means (M2a) converts the second original image (20) input by the invisible image input means (M1a) and the first original image (10) input by the visible image input means (M1b) into a grayscale image (8 bits) if they are RGB images or monochrome binary images.

[0109] The tone curve adjustment means (M2b) performs density correction on the first base image (10) and the second base image (20) which are grayscale images (8 bits).

[0110] The text pattern conversion means (M2c) repeatedly arranges the third original image (30) such as characters and symbols obtained by the text input means (M1c) and converts it into an information pattern image (31) consisting of a multi-bit format bitmap image having continuous gradation.

[0111] The image data generating means (M2d) uses each image data after tone curve adjustment and the information pattern image (31) to generate image data for forming the first print layer (4A) and the second print layer (5A).

[0112] The combining means (M2e) combines the image data for forming the first print layer (4A) and the second print layer (5A) obtained by the image data generating means (M2d).

[0113] (Other means) The printing means (P) is a printing device capable of printing images from a computer, such as a laser printer or inkjet printer, or a printing machine equipped with a printing mechanism for offset printing or relief printing, which uses a plate made by a known platemaking method based on image data created by a device for creating image data for prints (M) that can be authenticated, but is not particularly limited to this. The display means (M5) is not particularly limited to a computer monitor, a dedicated monitor, etc. The communication interface (M3) is not particularly limited to a USB, RS-232C, IEEE1394, etc.

[0114] (Method for creating image data for print that can be authenticated) Next, a method for creating image data for a printed matter that can be authenticated using the above-mentioned creation device (M) will be described with reference to Figure 19. Note that a method for creating data for forming a printed matter (1) in which the information elements (3A3, 3A4) that make up the print pattern (3) are configured by a first print layer (4A) and a second print layer (5A) superimposed on top of it will be described. Also, to easily explain the method for creating data for an anti-counterfeit printed matter of the present invention, an example will be described in which the first print layer (4A) is formed with cyan ink, magenta ink, and yellow ink, and the second print layer (5A) is formed with black ink containing carbon black.

[0115] (Base image setting process) The reference numeral (S1) in Fig. 19 denotes a process (hereinafter referred to as the "base image setting process (S1)") consisting of a first base image setting process (S1-1) in which data for a first base image (10) including an image that will be the basis for the first significant information is set in the form of a grayscale image by a visible image input means (M1b) of a device (M) for creating image data for authenticity-distinguishable printed matter, and a second base image setting process (S2-1) in which data for a second base image (20) that will be the basis for the second significant information is set in the form of a grayscale image by an invisible image input means (M1a). Note that the first base image (10) corresponds to the image data to be processed to form the first printing layer (4A), and the second base image (20) corresponds to the image data to be processed to form the second printing layer (5A).

[0116] In this embodiment, as shown in FIG. 20(a), the first significant information is a landscape image with gradation, and an image including the background is set as the first base image (10), and as shown in FIG. 20(b), a facial image with gradation is set as the second base image (20). However, the configuration of the set base image is not limited to this. For example, like the first significant information described in the configuration of printed matter (1), the first base image (10) may be an image in which the "star" design and its background each have a uniform density. Also, like the second significant information described in the configuration of printed matter (1), the second base image (20) may be an image in which the "moon" design has a uniform density.

[0117] Figure 20(c) is a diagram showing each area constituting the print pattern (3) corresponding to the first base image (10) shown in Figure 20(a) and the second base image (20) shown in Figure 20(b). In the first base image (10) shown in Figure 20(a), the first significant information of the "landscape image" corresponds to the first image portion (3-2) and the common image portion (3-4) shown in Figure 20(c), and the first base image (10) is an image including areas (3-1, 3-3) that form the background of the first significant information.

[0118] Furthermore, the second significant information of the "face image" shown in Fig. 20(b) corresponds to the second image portion (3-3) and the common image portion (3-4) shown in Fig. 20(c). In this way, the first base image (10) is an image corresponding to each area (3-1, 3-2, 3-3, 3-4) constituting the printed pattern (3) where the first printing layer (4A) is formed, and the second base image (20) is an image corresponding to each area (3-3, 3-4) where the second printing layer (5A) is formed.

[0119] The first base image (10) and the second base image (20) are set by the invisible image input means (M1a) and the visible image input means (M1b) by capturing images with a digital camera or by reading images previously registered in a database (M4). If the images input by the invisible image input means (M1a) and the visible image input means (M1b) are grayscale images (8 bit), they are set as the first base image (10) and the second base image (20) as is. If they are RGB images or monochrome binary images, they are converted to grayscale images (8 bit) by the grayscale conversion means (M2a) and set as the first base image (10) and the second base image (20). The processing performed by the grayscale conversion means (M2a) can be performed, for example, using the mode conversion processing function of Photoshop (registered trademark), an image processing software made by Adobe (registered trademark). The first base image (10) and the second base image (20) must be set to images of the same resolution (the same number of pixels in both the vertical and horizontal directions), and if the resolution of the input images is different, the resolution can be changed to make them images of the same resolution. The resolution change process can be performed using the resolution change function of PhotoShop (registered trademark).

[0120] (Density correction process) The symbol (S2) shown in Figure 19 indicates a process (hereinafter referred to as the "concentration correction process (S2)") in which a first density correction process (S2-1) is performed on the data of the first base image (10) to generate a first density-corrected image (11) corresponding to the first printing layer (4A) formed with cyan ink, magenta ink, and yellow ink, and a second density correction process (S2-2) is performed on the data of the second base image (20) to generate a second density-corrected image (21) corresponding to the second printing layer (5A) formed with black ink containing carbon black.

[0121] (First density correction process) The first density correction process (S2-1) compresses the density of the first base image (10) to the shadow side gradation. Specifically, the first tone curve (T1) shown in FIG. 21(b) is applied to the first base image (10) shown in FIG. 21(a) to generate the first density-corrected image (11) shown in FIG. 21(c). FIG. 21(b) is an example of the first tone curve (T1) that compresses the density of the first base image (10) to the shadow side gradation, and corresponds to a conversion formula for density conversion by connecting two points where the dot area rate of 0% in the first base image (10) is 20% and the dot area rate of 100% in the first base image (10) is 100% with a straight line. By applying the first tone curve (T1) shown in Fig. 21(b), the first original image (10) is compressed in density and converted into a first density-corrected image (11) in which the entire image is darker toward the shadow side. Note that the process of applying (setting) the tone curve shown in Fig. 21(b) as the first density correction process (S2-1) can be performed by, for example, setting a predetermined tone curve using a tone curve change function in Photoshop (registered trademark), which is image processing software made by Adobe (registered trademark). The tone curve adjustment means (M2b) of the present invention can simply use this function, and the same is true for the second density correction process (S2-2).

[0122] (Second density correction process) The second density correction process (S2-2) compresses the density of the second base image (20) to a gradation on the highlight side that is equal to or lower than the minimum density of the first density-corrected image (11). Specifically, the second base image (20) shown in FIG. 22(a) is applied to the second tone curve (T2) shown in FIG. 22(b) to generate the second density-corrected image (21) shown in FIG. 22(c). FIG. 22(b) is an example of the second tone curve (T2) that compresses the density of the first density-corrected image (11) to a gradation on the highlight side that is equal to or lower than the minimum density of the first density-corrected image (11). This corresponds to a conversion formula for density conversion, where a straight line connects the two points where the dot area rate of 0% in the second base image (20) is 0% and the dot area rate of 100% in the second base image (20) is 20%. By applying the second tone curve (T2) shown in Figure 22(b), the density of the second original image (20) is compressed and the entire image is converted into a second density-corrected image (21) on the bright highlight side.

[0123] In the density correction step (S2), the density must be corrected so that the maximum area ratio (20% in this case) of the second density-corrected image (21) is equal to or less than the minimum area ratio (20% in this case) of the first density-corrected image (11). This is because the second print layer (5A) formed based on the second density-corrected image (21) is formed by overlaying it on the first print layer (4A) formed based on the first density-corrected image (11). Here, an example has been described in which the density is corrected so that the minimum area ratio of the first density-corrected image (11) is 20% in the density correction step (S2), but the present invention is not limited to this. If it is desired to widen the range in which the density of the second significant information can be expressed, the density can be converted so that the maximum area ratio of the second density-corrected image (21) is increased (the minimum area ratio of the first density-corrected image is correspondingly increased, and the range in which the density of the first significant information can be expressed is narrowed). Furthermore, here, an example has been described in which the minimum area ratio (20%) of the first density-corrected image (11) converted by the first tone curve (T1) is the same as the maximum area ratio (20%) of the second density-corrected image (21) converted by the second tone curve (T2), but the maximum area ratio of the second density-corrected image (21) converted by the second tone curve (T2) may be smaller than the minimum area ratio of the first density-corrected image (11).

[0124] (Information pattern image generation process) The code (S3) shown in Figure 19 consists of a process (S3-1) of setting an image (hereinafter referred to as the "third original image (30)") in which desired characters, symbols, figures, etc. are composed of lines, which will serve as the original image for forming the information pattern (3A), and a process (S3-2) of repeatedly arranging the set third original image (30) and converting it into an information pattern image (31) (hereinafter referred to as the "information pattern image generation process (S3)").

[0125] The step (S3-1) of setting a third base image is performed by the text input means (M1c) by typing on a keyboard or by reading out characters and symbols stored in advance in a database (M4) or an external database server connected by the communication interface (M3). Here, an example will be described in which the character "A" shown in Fig. 23(a) is set in the step (S3-1) of setting a third base image, but the third base image (30) is not limited to this and may be one formed of characters, symbols, figures, etc. using lines, or one formed of a combination of these.

[0126] In the information pattern image generating step (S3-2), the third original image (30) set in the third original image setting step (S3-1) is repeatedly arranged within the same image size as the first density-corrected image (11) and the second density-corrected image (21) by the text pattern conversion means (M2c), generating the information pattern image (31) shown in FIG. 23(b). The image format of the information pattern image (31) is not particularly limited, and may be an 8-bit grayscale image, a black-and-white binary image, an RGB image, or the like. The spacing between the letters "A" shown in FIG. 23(b) corresponds to the pitch (P1, P2) of the information pattern (3A) in the configuration of the printed matter (1) described above, and therefore the information pattern image may be repeatedly arranged according to the desired printed matter (1). The information pattern image generating step (S3-2) can be performed by the text pattern conversion means (M2c), for example, using a function for inputting and arranging characters in general word processing software or image processing software.

[0127] (Image data generation process) The symbol (S4) shown in Figure 19 indicates a process (hereinafter referred to as the "image data generation process (S4)") in which the image data generation means (M2d) performs a process (S4-1) of generating image data for the first printing layer (12) using the first density correction image (11) and the information pattern image (31), and a process (S4-2) of generating image data for the second printing layer (22) using the second density correction image (21) and the information pattern image (31).

[0128] (Generation of image data for first printing layer) The process (S4-1) for generating first print layer image data involves replacing the "landscape image" represented by the first density-corrected image (11) with the letter "A" that constitutes the information pattern image (31) in a first density-corrected image (11) and an information pattern image (31) that are generated with the same image size (consisting of the same number of pixels), thereby generating first print layer image data (12). Figure 24 is a diagram showing the first print layer image data (12) generated by the process (S4-1) for generating first print layer image data. As shown in the enlarged view, the line width of the letter "A" is varied to represent a "landscape image" with gradation. The process (S4-1) for generating first print layer image data will be described in detail below.

[0129] Fig. 25 is a diagram illustrating the process (S4-1) for generating first print layer image data, in which, for example, in a first density-corrected image (11) and an information pattern image (31) of the same image size shown in Fig. 25(a) and Fig. 25(b), the pixels constituting the letter "A" surrounded by a thick line shown in Fig. 25(b) are sequentially converted so that the line width of the letter "A" varies depending on the density of the first density-corrected image (11) in the same positional relationship, to generate first print layer image data (12). Note that the first density-corrected image (11) in the same positional relationship refers to an image formed by a collection of pixels in the same position based on the respective origins (O1, O2) when the origins of the images shown in Fig. 25(a) and Fig. 25(b) are respectively designated by symbols (O1, O2).

[0130] FIG. 25(c) is an enlarged view of the letter "A" in the first density-corrected image (11) and the information pattern image (31) which are in the same positional relationship, and each image is composed of a plurality of pixels. The process (S4-1) for generating image data for the first printing layer generates the image data for the first printing layer (12) shown in FIG. 25(d) by referring to the density of the first density-corrected image (11) which overlaps with the pixels which make up the letter "A". In this case, the higher the density of the first density-corrected image (11) to be referred to, the wider the image width (W) of the letter "A" shown in FIG. 25(d) becomes. 31 ) is wider, thereby generating first printing layer image data (12) for forming an information pattern (3A) in which the stroke width of the character "A" varies depending on the density of the "landscape image" with gradations. Here, an example is shown in which the entire first density-corrected image (11) shown in FIG. 25(c) is configured with a uniform density, and in this case, first printing layer image data (12) in which the character "A" is configured with the same stroke width is generated, as shown in FIG. 25(d). Next, the process (S4-1) for generating first printing layer image data will be described in detail using a specific example.

[0131] 26A and 26B are diagrams for explaining the process of adjusting the stroke width of the character "A" in accordance with the density of the first density correction image (11) in the present invention. Here, the process of converting a partial area (E1) of the character "A" in the information pattern image (31) shown in FIG. 26A will be explained.

[0132] Figures 26(b), 26(c), and 26(d) are diagrams showing first printing layer data (12) generated when the densities are different in a first density-corrected image (11) that overlaps with pixels constituting a partial area (E1) of the character "A" in the information pattern image (31) shown in Figure 26(a). For ease of explanation, the first density-corrected image shown in Figure 26(b) will be described as reference numeral (11a), the first density-corrected image shown in Figure 26(c) as reference numeral (11b), and the first density-corrected image shown in Figure 26(d) as reference numeral (11c), and the first printing layer image data into which each image is converted will be described as reference numerals (12a, 12b, 12c). It should be noted that the image density increases in the order of the first density-corrected image (11a) shown in Figure 26(b), the first density-corrected image (11b) shown in Figure 26(c), and the first density-corrected image (11c) shown in Figure 26(d).

[0133] The first printing layer image data (12a) shown in Figure 26(b) is an image converted with reference to the density of the first density-corrected image (11a), and here shows an example in which the width of a portion of the image line of the character "A" is converted to a width of two pixels in the Y-axis direction (the vertical direction in the image of Figure 26(b)). The first printing layer image data (12b) shown in Figure 26(c) is an image converted with reference to the density of the first density-corrected image (11b), and here shows an example in which the width of a portion of the image line of the character "A" is converted to a width of four pixels in the Y-axis direction (the vertical direction in the image of Figure 26(c)). The first printing layer image data (12c) shown in Figure 26(d) is an image converted with reference to the density of the first density-corrected image (11c), and here shows an example in which the width of a portion of the image line of the character "A" is converted to a width of six pixels in the Y-axis direction (the vertical direction in the image of Figure 26(d)). In this way, by varying the character width when converting in the process (S4-1) of generating image data for the first printing layer, it is possible to generate image data for the first printing layer (12a, 12b, 12c) corresponding to the density of the first density correction image (11a, 11b, 11c).

[0134] Figure 26 is an example of a process (S4-1) for generating image data for the first printing layer of the present invention, and the extent to which the width of the characters in the image data for the first printing layer (12) is converted can be changed appropriately depending on the density of the first density correction image (11).

[0135] For example, when converting to an image with an intermediate density between the first density-corrected image (11a) shown in Fig. 26(b) and the first density-corrected image (11b) shown in Fig. 26(c), the width of a portion of the image line of the character "A" in the first printing layer image data (12) may be converted to a width of three pixels in the Y-axis direction, as shown in Fig. 27(a), or the width may be expanded by shifting one pixel alternately in the X-axis direction and the Y-axis direction based on the first printing layer image data (12a) shown in Fig. 26(b), as shown in Fig. 27(b). The first printing layer image data (12a) shown in Fig. 27(a) and Fig. 27(b) can express the same density because the number of pixels constituting part of the character "A" is the same.

[0136] It is also possible to express the density stepwise between the first density-corrected image (11a) shown in FIG. 26(b) and the first density-corrected image (11b) shown in FIG. 26(c).

[0137] Figures 28(a) and 28(b) show examples in which the spacing between pixels arranged in the X-axis direction is varied based on the first printing layer image data (12a) shown in Figure 26(b). As shown in Figure 28, by adjusting the number of pixels that make up an image line within the same image area, it is possible to express fine shading. Also, while Figure 28 shows an example in which the number of pixels arranged in the X-axis direction is adjusted, shading can also be expressed by adjusting the number of pixels arranged in the Y-axis direction, as shown in Figures 29(a) and 29(b).

[0138] Also, for example, the width of a portion of the image line of the character "A" shown in Figure 26(b) may be converted to one pixel in the Y-axis direction, the width of a portion of the image line of the character "A" shown in Figure 26(c) may be converted to three pixels in the Y-axis direction, and the width of a portion of the image line of the character "A" shown in Figure 26(d) may be converted to five pixels in the Y-axis direction. In any case, in the process (S4-1) of generating the first printing layer image data of the present invention, the width of the character in the first printing layer image data (12), i.e., the number of pixels constituting the character, may be adjusted to convert it so as to represent the density of the first density-corrected image (11).

[0139] Figure 30 is a diagram showing another example of the process (S4-1) for generating image data for the first printing layer of the present invention, and is a diagram explaining the process of converting into image data for the first printing layer (12) in an area (E2) different from the converted area (E1) in the character "A" shown in Figure 26(a).

[0140] While part of the characters in area (E1) shown in Fig. 26(a) has horizontal lines, part of area (E2) in the information pattern image (31) shown in Fig. 30(a) has vertical lines, and an example of converting these parts will be described. For ease of explanation, the first density-corrected image shown in Fig. 30(b) will be referred to as reference numeral (11d), the first density-corrected image shown in Fig. 30(c) as reference numeral (11e), and the first density-corrected image shown in Fig. 30(d) as reference numeral (11f), and the first printing layer image data into which these images are converted will be referred to as reference numerals (12d, 12e, 12f). Note that the image density increases in the order of the first density-corrected image (11d) shown in Fig. 30(b), the first density-corrected image (11e) shown in Fig. 30(c), and the first density-corrected image (11f) shown in Fig. 30(d).

[0141] The first printing layer image data (12d) shown in Figure 30(b) is an image converted by referring to the density of the first density correction image (11d), and here shows an example in which the width of a portion of the stroke of the character "A" is converted to a width of two pixels in the X-axis direction (the horizontal direction in the image of Figure 30(b)).

[0142] Furthermore, the first printing layer image data (12e) shown in Figure 30(c) is an image converted by referring to the density of the first density correction image (11e), and here shows an example in which the width of a portion of the image line of the character "A" is converted to a width of four pixels in the X-axis direction (the horizontal direction in the image of Figure 30(c)).

[0143] Furthermore, the first printing layer image data (12f) shown in FIG. 30(d) is an image converted with reference to the density of the first density-corrected image (11f). Here, an example is shown in which the width of a portion of the image line of the character "A" is converted to a width of six pixels in the X-axis direction (the horizontal direction in the image of FIG. 30(d)). In this way, when an image line is arranged vertically in the information pattern image (31), the width is adjusted in the X-axis direction for conversion, thereby generating first printing layer image data (12d, 12e, 12f) corresponding to the density of the first density-corrected image (11d, 11e, 11f). Note that when converting to an image with a density intermediate between the first density-corrected image (11d) shown in FIG. 30(b) and the first density-corrected image (11e) shown in FIG. 30(c), the direction of width adjustment is different, but conversion can be performed in the same manner as described in paragraph (0115). In addition, in this embodiment, an example has been described in which horizontally arranged lines and vertically arranged lines in the information pattern image (31) are converted by adjusting the widths in the X-axis direction and the Y-axis direction, but conversion processing may be performed by adjusting the widths in the X-axis direction and the Y-axis direction simultaneously.

[0144] FIG. 31 is a diagram illustrating an example of a process for converting an image having partially different densities in the first density-corrected image (11).

[0145] The first density correction image (11) shown in FIG. 31(a) is an example in which the upper half is a light density image and the lower half is a dark density image. In this case, the first print layer image data (12) of the character "A" to be converted has a line width (W 31A ) is thin, and the image width of the lower half (W 31B) is converted into a thick image. Note that FIG. 31(a) shows an example of the density of the first density-corrected image (11), and in reality, the first density-corrected image (11) is an image with shading as shown in FIG. 25(a), and the conversion process is performed according to the density of the first density-corrected image (11) that is in the same positional relationship as the pixels that make up the character "A." Also, here, the process of converting one character "A" shown in FIG. 25(b) into the first printing layer image data (12) has been described. However, the process (S4-1) of generating the first printing layer image data can generate the first printing layer image data (12) that represents the "landscape image" with gradations as shown in FIG. 24 by converting the entire information pattern image (31) shown in FIG. 25(b) according to the density of the first density-corrected image (11) that is in the same positional relationship as each pixel that makes up the character "A."

[0146] The process of adjusting and converting the width of the character "A" shown in Figure 25(d) by referring to the density of the first density-corrected image (11) by the image data generating means (M2d) can be performed by applying a threshold value array image for which the conversion rules described in paragraphs (0108) to (0120) have been defined in advance, and can be performed, for example, by using a custom pattern created in advance in the mode conversion processing function of Photoshop (registered trademark), an image processing software made by Adobe (registered trademark).In addition, the first printing layer image data (12) can be generated by creating in advance conversion software that adjusts the line width of the converted image according to the density of the first density-corrected image (11) for each character or symbol set as the third base image (30).

[0147] (Generation of image data for second printing layer) The process (S4-2) for generating second print layer image data involves replacing the "face image" represented by the second density-corrected image (21) with the letter "A" constituting the information pattern image (31) in the second density-corrected image (21) and information pattern image (31), both of which are generated with the same image size (consisting of the same number of pixels). This generates second print layer image data (22). Figure 32 shows the second print layer image data (22) generated by the process (S4-2) for generating second print layer image data. As shown in the enlarged view, the "face image" with gradation is expressed by varying the stroke width of the letter "A." The second print layer image data (22) shown in Figure 32 is an image corresponding to second significant information visible under specific observation conditions. When the image is formed using black ink containing carbon black, as in this embodiment, the "face image" can be visually recognized by observing it with an infrared camera. Details of the process (S4-2) for generating second print layer image data are described below.

[0148] The process (S4-2) for generating the second printing layer image data is similar to the process (S4-1) for generating the first printing layer image data, and sequentially converts the second printing layer image data (22) so that the line width of the character "A" varies depending on the density of the second density-corrected image (21) that is in the same positional relationship as the pixels that make up the character "A" in the information pattern image (31). Note that the process for adjusting and converting the width of the character "A" shown in Fig. 32 by referring to the density of the second density-corrected image (21) can be performed by the same conversion method as the process (S4-2) for generating the first printing layer image data, and can be performed using, for example, a custom pattern created in advance in the mode conversion processing function of Photoshop (registered trademark), an image processing software by Adobe (registered trademark), as the image data generating means (M2d).

[0149] As described above, in the density correction process (S2), the density is corrected so that the maximum area ratio (the darkest part of the "face image") of the second density-corrected image (21) is equal to or less than the minimum area ratio (the lightest part of the "landscape image") of the first density-corrected image (11). Therefore, the maximum value of the stroke width of the character "A" converted by the process (S4-2) for generating image data for the second printing layer is equal to or less than the minimum value of the stroke width of the character "A" converted by the process (S4-1) for generating image data for the first printing layer.

[0150] The image data for the first printing layer (12) and the image data for the second printing layer (22) created by the method of creating image data for printed matter that can be authenticated according to the present invention may be stored separately in a database (M4), or may be stored in a database (M4) as a single image data synthesized by a synthesis means (M2e).

[0151] An authentically distinguishable anti-counterfeit printed matter (1) can be produced by printing the first printing layer image data (12) and the second printing layer image data (22) created by the method for creating authentically distinguishable image data for a printed matter onto a substrate (2) using an output means (P) such as a laser printer or inkjet printer. The first printing layer image data (12) and the second printing layer image data (22) or the combined image data thereof can be in any format, such as bitmap or JPEG. In the case of PDF (Adobe Portable Document format), the image data can be saved as image data for each color of ink, i.e., cyan ink, magenta ink, yellow ink, and black ink including carbon black. The PDF format image data can be used directly to print the first printing layer image data (12) and the second printing layer image data (22) using a digital printing machine.

[0152] In addition, using the stored data, printing plates for cyan, magenta, and yellow inks and a printing plate for black ink containing carbon black can be prepared by a known platemaking process, and printed on a predetermined printing press to produce a printed matter (1) whose authenticity can be discerned. Furthermore, the image data for the first printing layer (12) and the image data for the second printing layer (22) created by the method for creating image data for a printed matter whose authenticity can be discerned of the present invention can be displayed on a display means (M5) so that it can be confirmed that the image data has been created.

[0153] In this embodiment, as shown in Fig. 23(b), an example is shown in which the information pattern image (31) has the letter "A" repeatedly arranged, but as shown in Fig. 33(a), an information pattern image (31) in which different letters are arranged within an area surrounded by a dashed line may also be used. Also, as shown in Fig. 33(b), an information pattern image (31) in which the letters "ABC" are repeatedly arranged within an area surrounded by a dashed line may also be used. Also, as shown in Fig. 33(c), an information pattern image (31) in which the letters "ABC" are arranged shifted to the left and right of the area surrounded by a dashed line may also be used.

[0154] As shown in Figure 33, when the characters constituting the information pattern image (30) are different, a critical value array image for conversion is created in advance for each different character by referring to the density of the first density-corrected image (11), and the pixels constituting the different characters in the information pattern image (30) are converted sequentially according to the density of the first density-corrected image (21) in the same positional relationship so that the line width of the character varies, thereby generating the first printing layer image data (12). When converting the information pattern image (30) into different characters, if the densities referred to in the first density-corrected image (11) are the same, a critical value array image is created in advance so that the number of pixels is the same (the areas of the information patterns representing different characters are equal), and conversion is performed, thereby making it possible to produce the printed matter (1) configured as described in paragraph (0070).

[0155] When the data created by the method described above is printed on a substrate (2) using a desired printing method, a printed matter (1) is obtained in which a second printing layer (5A) formed of black ink containing carbon black overlaps a portion of a first printing layer (4A) formed of cyan ink, magenta ink, and yellow ink (e.g., Figure 6(b)). However, when processing is performed to remove the portion of the image data (12) for the first printing layer that overlaps with the second printing image data (22) and printing is performed based on each data, a printed matter (1) is obtained in which the first printing layer (4A) and the second printing layer (5A) are juxtaposed (e.g., Figure 7(b)). [Explanation of symbols]

[0156] 1. Authenticated printed matter (printed matter) 2 Base material 3 Printing pattern 3-1 Background part 3-2 First image section 3-3 Second Image Section 3-4 Common image section 3A printing area 3A1 printing area (background part) 3A2 print area (first image area) 3A3 print area (second image area) 3A4 print area (common image area) 4A First printing layer 5A Second printing layer 6A Camouflage Elements 10 First base image 11 First density correction image 12 Image data for first printing layer 20 Second base image 21 Second density correction image 22 Image data for second printing layer 30 Third base image 31 Information Pattern Images M. A device for creating image data for print that can be identified as authentic M1 Input Method M2 editing method M3 communication interface M4 database M5 Display means

Claims

1. A printed pattern is provided on at least a portion of a substrate, in which a plurality of information patterns are arranged, each of which is formed by image lines representing information; The printing pattern is The area ratio of the information pattern is partially different, so that the information pattern is divided into a first image portion and a common image portion constituting first significant information visible under visible light, and a second image portion and a background portion which form the background of the first significant information, the information pattern constituting the first image portion and the background portion is made of a first print layer made of a material of a different color from the base material; the information pattern constituting the common image area and the second image area is formed by stacking or juxtaposing the first print layer with a second print layer made of a material containing a functional material that has the same color as the first print layer and is visible under predetermined observation conditions, the second print layer forms second significant information that is visible under the predetermined observation condition; In each of the first image portion, the common image portion, the second image portion and the background portion, at least one of the information patterns arranged in each of the areas represents different information, A printed matter capable of being authenticated, characterized in that the information pattern is formed with the same area ratio in each of the regions.

2. The first printing layer is formed in black by mixing cyan ink, magenta ink, and yellow ink, 2. The authenticity-determinable printed matter according to claim 1, wherein the second printed layer is formed of black ink having infrared absorbing properties.

3. A printed pattern having a plurality of information patterns, each of which is formed by lines and represents information, arranged on at least a portion of a substrate, The printing pattern is The area ratio of the information pattern is partially different, so that the information pattern is divided into a first image portion and a common image portion constituting first significant information visible under visible light, and a second image portion and a background portion which form the background of the first significant information, the information pattern constituting the first image portion and the background portion is made of a first print layer made of a material of a different color from the base material; the information pattern constituting the common image area and the second image area is formed by stacking or juxtaposing the first print layer with a second print layer made of a material containing a functional material that has the same color as the first print layer and is visible under predetermined observation conditions, A method for creating image data for producing an authentic printout in which second significant information visible under the predetermined observation conditions is formed by the second print layer, the method comprising: a base image setting step of setting a first base image including an image that is a basis of the first significant information visible under the visible light and a second base image that is a basis of the second significant information visible under the predetermined observation conditions to have the same image size; a density correction process including a first density correction process for converting the first original image into a first density-corrected image by applying a first tone curve for compressing the first original image into a shadow-side gradation, and a second density correction process for compressing the second original image into a highlight-side gradation that is equal to or lower than the minimum density of the first density-corrected image, thereby converting the second original image into a second density-corrected image; an information pattern image generating step of generating an information pattern image by arranging a plurality of third original images, which are the basis of the information pattern in which information is expressed by image lines, within an image area having the same size as the first density-corrected image and the second density-corrected image; A method for creating image data for printed matter that can be authenticated, characterized in that it comprises an image data generation process comprising: a process for generating image data for a first printing layer by adjusting and converting the line width of the third base image in accordance with the density of an image that is in the same positional relationship as the first density-corrected image in the third base image that constitutes the information pattern image; and a process for generating image data for a second printing layer by adjusting and converting the line width of the third base image in accordance with the density of an image that is in the same positional relationship as the second density-corrected image.

Images