JP2008068511A - Printed matter in which truth distinction is possible - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed matter capable of being applied to articles of value which makes it possible to determine whether it is true or not. <P>SOLUTION: A first area and a second area are arranged on a base material, thereby a background pattern is formed, a printing pattern is formed on the background pattern, the second area is arranged in the first area by trapping to form a latent image, the first area forms an image excepting the second area for forming the latent image from the background pattern, the first area is printed in a first printing ink, and the second area in a second printing ink, wherein the first printing ink and the second printing ink have metameric pair ink relation with the printing pattern printed in at least one color ink with a color different from the background pattern. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printed matter capable of authenticating authenticity applicable to valuables such as banknotes, passports, securities, cards, stamps, product tags, toll roads and various valuable tickets.

  With the recent development of digital devices such as scanners, printers, color copiers, etc., it has become possible to easily produce elaborate copies of precious printed matter. As one of the countermeasures, many methods using a metameric pair ink applying metamerism as a visual identification method have been tried. The method of visual discrimination of precious printed matter using metameric pair ink utilized the characteristic that the ink looks the same color or looks different due to the type of light source to illuminate and the filter that transmits a specific wavelength. Is. Conventionally, a method of utilizing optical properties due to ink metamerism in printed matter that requires anti-counterfeiting technology has been used.

  Usually, a printed matter printed with a colored metameric pair ink has two wavelength regions, a wavelength region A which is a visible total wavelength of 400 to 700 nm, and a wavelength region B which is a predetermined wavelength transmitted by a predetermined filter or the like to be used. Observed in the wavelength region.

  The printed matter A1 shown in FIG. 1A forms a visible image 2 on the substrate 1, and the visible image 2 is printed with the first region 3 printed with the first ink and the second ink. 2 regions 4. When the printed matter A1 is observed with the naked eye under normal light from sunlight, a fluorescent light, an incandescent light bulb, or the like, as shown in FIG. The second region 4 printed with the second ink is visually recognized in the same color, and only the visible image 2 can be confirmed. When the printed matter A1 is observed with the naked eye through a predetermined filter or the like, as shown in FIG. 1C, the first region 3 printed with the first ink and the second ink printed with the second ink are used. Since the color of the area 4 of 2 is visually recognized differently, it can be confirmed as a latent image. The printed matter A1 is determined to be genuine when the color difference between the first region 3 and the second region 4 occurs through the predetermined filter 10 or the like with respect to the visible image 2, and the color difference does not occur. Judgment of authenticity is performed by determining that the object is fake.

  As another method for determining the authenticity of a printed material using another metameric pair ink, there is a method that uses a change in contrast between the pair inks. In this method, since the specific wavelength region is set to a region limited to a range of about several tens of nanometers, the hue changes only slightly, but there is a difference in reflection or absorption characteristics in the specific wavelength region between the paired inks. Since it appears more conspicuously, only the density of the first region 3 in FIG. 1 decreases, the second region 4 is emphasized, and the second region 4 appears to appear as a latent image. As described above, there is also a true / false discrimination method that authenticates the presence / absence of a latent image through a filter and performs true / false discrimination.

  In any case, in each of the above-described methods for authenticating the presence or absence of a hue change or the appearance of a latent image, the authenticity determination using the metameric pair ink is based on the reflection / absorption characteristics of the ink in a specific wavelength region. The difference is used.

  For example, it looks the same color under normal light from sunlight, fluorescent lamps, incandescent lamps, etc., but it is viewed under a light source having a predetermined spectral energy distribution, through a predetermined filter, or passed through a predetermined filter. Anti-counterfeiting, characterized in that two types of colorants, which have metallic properties that look different when viewed under bright light, are formed on a substrate so that the patterns can be compared with each other. An image forming body with a countermeasure is disclosed (see Patent Document 1).

  In addition, the present applicant assigns metameric pair inks with different near-infrared characteristics, and prints using the two types of metameric pair inks can reflect or transmit light of two different wavelengths in the near-infrared region. An application has been filed for a true / false discrimination method and apparatus for reading in terms of voltage (see Patent Document 2).

Japanese Examined Patent Publication No. 60-58711 (page 1-4, FIG. 1-11) Japanese Patent No. 3709539 (page 1-6, FIG. 1-6)

  However, the printed matter printed with the conventional metameric pair ink is generally printed in a solid print pattern when authenticating the hue change or the presence or absence of the latent image, and the latent image is a basic form. In most cases, a part of the image is blanked as it is, and the latent image is superposed on the blanked part and replaced with a so-called simple “pull out” configuration. Therefore, since colors of a plurality of colors are not used, the colors are scarce. In addition, in order to obtain a plurality of colors, it is conceivable to overprint the ink of a color different from that of the metameric pair ink on the metameric pair printing. There is a problem that the printed area does not disappear and the metameric effect is impaired. Further, the latent image embedded in the background pattern may be visually recognized under normal light due to a slight difference in color and difference in gloss of the metameric pair ink. Furthermore, it was difficult to express gradation in the latent image, and there was no freedom of design.

  An object of the present invention is to solve such a conventional problem, and a printed pattern having a color different from the background pattern is superimposed on a background pattern including a latent image printed with a metameric pair ink. It is printed and has a plurality of colors consisting of a background pattern and a printed pattern under normal light without impairing the metameric effect. In addition, when observed with the naked eye through a predetermined filter or the like, the latent image is visually recognized with a clear density difference from an image obtained by removing the above-described region constituting the latent image from the background image and the background pattern. Therefore, it is possible to easily determine authenticity. If necessary, it is possible to add density gradation to the latent image, and there is no design restriction.

  An object of the present invention is to propose a printed matter printed with the above-mentioned metameric pair ink and capable of authenticating authenticity.

  In the present invention, a first pattern and a second pattern are arranged on a substrate to form a background pattern, a printed pattern is formed on the background pattern, and the second area is tipped in the first pattern. The first area forms an image excluding the second area for constructing the latent image from the background pattern, and the first area is the first print. Printed with ink, the second area is printed with a second printing ink, the printed pattern is printed with at least one color of ink different from the background pattern, and the first printing ink and the second printing ink are: Spectral reflectance approximates in the first wavelength range in the visible region, and different values of the metameric pair ink in the second wavelength range in the visible region, and at least one color ink that prints the printed pattern is: The spectral reflectance of the second printing ink is within the second wavelength range. Is authenticity discrimination possible printed matter characterized in that it is a ink higher than the rate spectral reflectance.

  In addition, the present invention is a printed matter capable of authenticating authenticity, wherein a plurality of first regions and second regions are arranged to form a background pattern.

  In the present invention, the integral value of the spectral reflection spectrum between 640 and 700 nm of the first printing ink is more than twice the integral value of the spectral reflection spectrum between 640 and 700 nm of the second printing ink. The integral value of the spectral reflection spectrum between 400 and 600 nm of the first printing ink is substantially the same as the integral value of the spectral reflection spectrum between 400 and 600 nm of the second printing ink. It is a printed material that can be checked for authenticity.

  In addition, the present invention is a printed matter capable of authenticating authenticity, wherein the latent image has a density gradation.

  Further, the present invention is a printed matter capable of authenticating authenticity, wherein at least one color ink for printing a printed pattern is magenta ink and / or yellow ink.

  In the present invention, the latent image is not visually recognized under normal light, and the background pattern and the printed pattern printed on the background pattern can be visually recognized. Without damaging the metameric effect, it has multiple colors under normal light. When the latent image is observed with the naked eye through a predetermined filter or the like, the latent image is visually recognized with a clear density difference from the image and the printed pattern excluding the region constituting the latent image described above from the background pattern. It is possible to easily determine authenticity. Further, according to the present invention, it is possible to give density gradation to a latent image as necessary.

  In addition, by using a combination of a halftone dot constituting the first region formed of the metameric pair ink and a halftone dot of the second region which is paired with the halftone dot, the overall density is made constant, so that It is possible to conceal the latent image.

  The print pattern 6 printed on the background pattern 4 can be provided with a plurality of colors. In addition, the printed material can be applied to valuable items that are not restricted by the design. Of course, it can be applied to printed materials other than valuables.

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

  Usually, the image formed by the metameric pair ink has two wavelength regions, a wavelength region A which is a visible total wavelength of 400 to 700 nm and a wavelength region B which is a predetermined wavelength transmitted by a predetermined filter or the like to be used. Observed at. In the embodiment of the present invention, the printed matter capable of authenticating authenticity is printed with two types of inks of the metameric ink and at least one type of ink printed on the area printed with the metameric ink.

(Embodiment 1)
FIG. 2 (a) shows a printed material B that can be authenticate. As shown in FIG. 2A, the first pattern 2 and the second pattern 3 are arranged on the substrate 1 to form the background pattern 4. A printed pattern 6 is formed on the background pattern 4. The second area 3 is arranged in the first area 2 by tweezers. In this hair removal, the second region 3 is formed in the non-printing region 9 of the first region 2 as shown in FIG. Further, as shown in FIG. 3, the boundary between the first region 2 and the second region 3 is printed without overlapping as shown in FIG. 3A, or as shown in FIG. 3B. The first region 2 and the second region 3 may have a region 8 in which a part of the first region 2 and the second region 3 overlap each other. In the partially overlapped area 8, the second area 3 may be printed on the first area 2 or the first area 2 may be printed on the second area 3. In this case, it is preferable to limit the overlapping area of one or both of the first area 2 and the second area 3 to a size that is not visible. It is preferable to adjust the density.

  As shown in FIG. 4, the background pattern 4 is formed by the first area 2 and the second area 3, the latent image 5 is formed by the second area 3, and the first area starts from the background pattern 4. An image 7 excluding the second region 3 for forming the latent image 5 is formed. A printed pattern 6 is overprinted on the background pattern 4.

  The image 7 excluding the second region 3 for constituting the latent image 5 from the background pattern 4 composed of the first region 2 is the first printing ink, and the latent image composed of the second region 3 is Printing is performed with the second printing ink. The printed pattern 6 printed on the background pattern 4 is printed with at least one color ink having a color different from that of the background pattern 4. The ink of at least one color is an ink having a spectral reflectance higher than that of the second printing ink in the second wavelength range. For example, the printed pattern 6 is printed with magenta ink and / or yellow ink. The dot area ratio of the printed pattern 6 printed on the background pattern 4 is not particularly limited.

  The relationship between the first printing ink and the second printing ink will be described. The spectral reflectances of the first printing ink and the second printing ink are approximated in the range of the first wavelength in the visible region, and have different values in the range of the second wavelength in the visible region. That is, the first printing ink and the second printing ink are in the relationship of the metameric pair ink. In addition, the integral value of the spectral reflection spectrum between 640 and 700 nm of the first printing ink has more than twice the integral value of the spectral reflection spectrum between 640 and 700 nm of the second printing ink. It is preferable that the integral value of the spectral reflection spectrum between 400 and 600 nm of the printing ink is substantially the same as the integral value of the spectral reflection spectrum between 400 and 600 nm of the second printing ink.

  FIG. 5 is an example of a spectral reflectance curve of the first printing ink and the second printing ink that are the metameric pair inks used in the present invention. As shown in FIG. 5, the relationship between the spectral reflectances of the first printing ink and the second printing ink is designed so that a spectral reflectance difference of 30% or more is generated between 640 to 700 nm, and 20% at 400 to 600 nm. The first printing ink and the second printing ink are produced with a design that produces the following spectral reflectance difference. The first printing ink and the second printing ink having the spectral reflectance curve shown in FIG. 5 are tea-based color inks. However, in the present invention, the description is described using a brownish-colored metameric pair ink. However, the metameric pair is excellent in color matching under normal light and excellent in color difference in a specific wavelength range. If it is assumed that ink is used, there is no restriction on the color.

  The relationship between the first printing ink and the second printing ink, which are the metameric pair inks shown in FIG. 5, is designed so that a large difference occurs in the spectral reflectance of 640 nm or more, and the wavelength region B is the highest visible from 640 nm. The wavelength range is 700 nm. In FIG. 5, a more remarkable difference in spectral reflectance is observed at 660 nm or more. However, when a sharp cut filter or the like that transmits light of 660 to 700 nm is used, the amount of light transmitted through a normal indoor light source is insufficient. Thus, no matter how excellent the reflection or absorption characteristics of the ink are, the entire image itself will darken and become almost invisible, so a strong light source is often required. From the above, the wavelength region B is set to 640 to 700 nm. Regarding the setting of this wavelength region B, it is sufficient to decide the authentication wavelength desired by the user, select an ink material according to the authentication wavelength, and produce a metameric pair ink. It is not limited.

  Next, the halftone dot area ratio of the image 7 excluding the second area 3 for constructing the latent image 5 from the background pattern 4 composed of the first area 2, and the halftone dot area ratio of the latent image 5. The relationship of the point area ratio will be described.

  An image 7 obtained by removing the second region 3 for forming the latent image 5 from the background pattern 4 made up of the first region 2 is printed at a halftone dot area ratio in the first predetermined range, and the second region 3 is printed. The latent image 5 is printed with a halftone dot area ratio in the second predetermined range. The halftone dot area ratio of the first predetermined range and the halftone dot area ratio of the second predetermined range need to be the same or substantially the same.

  The printed matter B1 that can be detected as authenticity is printed on the background pattern 4 and the background pattern 4 as shown in FIG. 6A under normal light from sunlight, fluorescent light, incandescent light bulb or the like having a specific wavelength A. The pattern 6 is confirmed, and the latent image 5 cannot be confirmed. Under normal light, multiple colors can be confirmed by the background pattern 4 and the printed pattern 6 printed on the background pattern 4.

  When the printed material B1 capable of authenticating authenticity is observed through a different light source in the wavelength region B or a predetermined filter 10 (for example, SC64 manufactured by FUJI FILM), the latent image 5 is confirmed as shown in FIG. The The image 7 excluding the second region 3 for constructing the latent image 5 from the background pattern 4 printed with the first printing ink is as if erased, and similarly, the color different from the background pattern 4 The printed pattern 6 printed with at least one color of ink appears to disappear, and only the latent image 5 appears to be visually recognized. Therefore, it is possible to easily determine authenticity.

(Embodiment 2)
The background pattern 4 of the printed matter B1 shown in FIG. 2 (a), which can be identified as authenticity, is formed by arranging the first region 2 and the second region 3 by tweezers, but FIG. 7 (a). The first region 2 and the second region 3 may be formed so as to be adjacent to each other as in the printed matter B2 that can be determined as authentic. The position in contact with the adjoining is not particularly limited. Further, the first region 2 and the second region 3 may be slightly separated from each other. Further, a printed pattern 6 having a color different from that of the background pattern 4 is overprinted on the background pattern 4 including the first area 2 and the second area 3. FIG. 7B shows a printed material B3 that can be determined as authentic. A line drawing line is formed by the first region 2 and the second region 3. Furthermore, a printed pattern 6 having a color different from that of the background pattern 4 is overprinted on the background pattern 4 having a line drawing shape formed of the first area 2 and the second area 3.

(Embodiment 3)
The background pattern 4 of the printed material B4 capable of authenticity determination shown in FIG. 8 is an example in which a plurality of first regions 2 and second regions 3 are arranged by tweezers. A printed pattern 6 is overprinted on the background pattern 4. By forming a plurality of the first regions 2 and the second regions 3 to be arranged, the first region 2 and the second region 3 are not visually recognized in a more divided manner under normal visibility. Further, a density gradation can be given to the latent image formed by the second region 3. The density gradation is formed by the difference in the size of the second region 3 shown in the enlarged view of FIG. The positional relationship between the first region 2 and the second region 3 is not limited to the enlarged view of FIG. 8, but can be formed according to the positional relationship of FIGS. 9A to 9D. 9B to 9D, the first region 2 is divided into a first region 2a and a first region 2b, and the first region 2b is the same as the first region 2a. It is possible to impart density gradation with ink. In FIG. 9B, the area of the first region 2a is smaller than the area of the first region 2b. In FIG. 9C, the area of the first region 2a is larger than the area of the first region 2b. In FIG. 9D, the area of the first region 2a is equal to the area of the first region 2b.

  In this case, as a means for concealing the latent image, a second dot for forming the latent image 5 from the halftone dots printed with the second printing ink for forming the latent image 5 and the background pattern 4 is used. The sum of the halftone dot area ratios of the combinations of the halftone dots of the first printing ink forming the image 7 excluding the region 3 is set to a constant value. The first area 2 and the second area are preferably printed at 60 to 700 line / inch.

  When using the metameric pair ink, the latent image viewed with a filter or the like uses only the light in the wavelength region B out of the light existing in the observation environment. In the wavelength region B, the amount of light itself is greatly reduced. Therefore, the reflection or absorption characteristics of the light in the wavelength region B are more strongly reflected, and the density is higher than that obtained in the wavelength region A. It can be made to feel visually. In other words, when the reflection or absorption characteristics of the ink in the wavelength region B are excellent, even if the concentration is only visible as a highlight level in the wavelength region A, the concentration of shadow from the middle when observed through a filter. It is possible to make the observer recognize.

  The halftone dot shape used in the present invention is not limited to a circular dot, but a random dot or a special halftone dot generation method proposed in Japanese Patent Application Laid-Open No. 11-268228 filed earlier by the present applicant. It is also possible to use a special halftone dot shape having a degree of freedom obtained by converting an input image with design characteristics into a continuous tone halftone dot composed of a halftone screen.

  Moreover, the base material used for the printed matter capable of authenticating authenticity of the present invention is not particularly limited, and paper sheets or films such as high-quality paper, coated paper, and art paper can be used.

  The printing method of the printed matter capable of authenticating authenticity of the present invention is not particularly limited, such as an offset printing method, a gravure printing method, a screen printing method, a flexographic printing method, an ink jet printer, or a laser printer. The offset printing method is particularly preferable because it is often required. When actually producing printed matter, in most printing methods, the dot area ratio is expected to increase due to dot gain between the printed matter and the plate surface. Needless to say, there is a need.

  The latent image is not a problem even if it is a simple binary image such as letters, numbers or symbols or a gradation image. Moreover, you may form a pattern with a background pattern.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, the content of this invention is not limited to the range of these Examples.

(Example)
In carrying out the invention, the first printing ink and the second printing ink shown in FIG. 5 were used. First, the gradation scales of the first printing ink and the second printing ink to be used were respectively printed, and the reflection density characteristics of both inks in the wavelength region A were confirmed as shown in FIG. In the wavelength region A, it is important that the halftone dot area ratio and the reflection density of the first printing ink and the second printing ink are in a substantially proportional relationship, and it has been confirmed that there is a proportional relationship. Next, in the wavelength region B, the density difference between the first printing ink and the second printing ink was determined by visual inspection through a sharp cut filter. Moreover, it is also possible to calculate with the integral value in the wavelength region B of the spectral spectrum in each dot area ratio of the first printing ink and the second printing ink.

  It was confirmed that the latent image 5 has a sufficient gradation in the wavelength region B when printed with the second printing ink in a range where the halftone dot area ratio is 80% or less. An image 7 excluding the second region 3 for constructing the latent image 5 from the background pattern 4 printed with the first printing ink is formed with a dot area ratio in the range of 0 to 80% or less. A halftone dot area ratio of a combination of halftone dots constituting the image image 5 and halftone dots of the image 7 excluding the second region 3 for constituting the latent image 5 from the background pattern 4 paired with the halftone dots. The sum of the values was a constant value (100%).

  The printed matter of Example was produced using the 1st printing ink and the 2nd printing ink which have the spectral reflectance curve shown in FIG. The image 7 excluding the second region 3 for constructing the latent image 5 from the background pattern 4 shown in the first embodiment is the first printing ink, the latent image 5 is the second printing ink, and the background. A printed pattern 6 formed on the pattern 4 was printed with an offset proofing printing machine with magenta ink and yellow ink, and a printed material C capable of determining authenticity was produced.

  As shown in FIG. 11, the printed material C capable of authenticating authenticity includes a plurality of first regions 2 and second regions 3 which are alternately adjacent to each other on the base material 1, and the first region 2 has the first region 2. A background pattern 4 is formed by arranging the two regions 3 by tapping. The halftone dot area ratio of the background pattern 4 was 100%. A printed pattern 6 (leaf) having gradation on the background pattern 4 was printed with magenta ink and yellow ink.

  As shown in FIG. 12 (a), the printed material C that can be determined as authentic is printed on the background pattern 4 and the background pattern 4 under normal light from a specific wavelength A such as sunlight, fluorescent light, or incandescent light bulb. The pattern 6 was confirmed, and the latent image 5 could not be confirmed. Under normal light, a plurality of colors could be confirmed by the background pattern 4 and the printed pattern 6 printed on the background pattern 4.

  As shown in FIG. 12B, the printed material C capable of authenticating authenticity has a density gradation when observed with light in the wavelength region B (640 nm to 700 nm) through the sharp cut filter 10 (SC64 manufactured by FUJI FILM). Only the latent image 5 was confirmed.

It is a figure which shows the conventional metameric pair printed matter. This is a printed material B1 of the present invention that can be determined authenticity. FIG. 3 is a diagram illustrating a boundary between a second region 3 and a third region 4. This is a printed material B1 of the present invention that can be determined authenticity. It is a figure which shows an example of the spectral reflectance curve of the 1st printing ink which is a metameric pair ink used by this invention, and a 2nd printing ink. It is explanatory drawing about the effect | action of the printed matter B1 which can authenticate authenticity of this invention. It is printed matter B2 and B3 which can authenticate authenticity of this invention. This is a printed material B4 of the present invention capable of authenticating authenticity. FIG. 3 is a diagram showing a positional relationship between a first area 2 and a second area 3. It is a figure which prints the gradation scale of 1st printing ink and 2nd printing ink, respectively, and shows the reflection density characteristic in the wavelength range A. FIG. It is explanatory drawing of the printed matter C which can authenticate authenticity of an Example. It is a figure which shows the effect | action of the printed matter C which can authenticate authenticity of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2, 2a, 2b 1st area | region 3 2nd area | region 4 Background pattern 5 Latent image 6 Printing pattern 7 The image remove | excluding the 2nd area | region 3 for comprising the latent image 5 from the background pattern 4 8 Partially overlapped area 9 Non-printing area 10 Filter A Printed material B1, B2, B3, B4, C Printed material with authenticity discrimination

Claims (5)

A background pattern is formed by arranging a first area and a second area on a substrate, a printed pattern is formed on the background pattern, and the second area is tipped together in the first area. Arranged to form a latent image, and the first region forms an image obtained by removing the second region for constructing the latent image from the background pattern, and the first region is Printing with a first printing ink, the second region is printed with a second printing ink, the printed pattern is printed with at least one color of ink different from the background pattern, and the first printing ink And the second printing ink is a metameric pair ink whose spectral reflectance approximates in the first wavelength range in the visible region and has a different value in the second wavelength range in the visible region. At least one color ink that prints the pattern has a spectral reflectance. Serial second authenticity discrimination possible prints, characterized in that in the wavelength range of a ink high spectral reflectance than the spectral reflectance of the second printing ink. 2. The printed matter capable of authenticating authenticity according to claim 1, wherein a plurality of the first region and the second region are arranged to form a background pattern. The integral value of the spectral reflection spectrum between 640 and 700 nm of the first printing ink has at least twice the integral value of the spectral reflection spectrum between 640 and 700 nm of the second printing ink,
The integral value of the spectral reflection spectrum between 400 and 600 nm of the first printing ink is substantially the same as the integral value of the spectral reflection spectrum between 400 and 600 nm of the second printing ink. The printed matter capable of authenticating authenticity according to claim 1 or 2. 4. The printed matter capable of authenticating authenticity according to claim 2, wherein the latent image has a density gradation. The printed matter capable of authenticating authenticity according to claim 1, 2, 3, or 4, wherein at least one color ink for printing the printed pattern is magenta ink and / or yellow ink.

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