JP4863118B2 - Image forming body - Google Patents

Description

  The present invention makes it difficult to forge with a color copying machine or the like on valuable printed matter such as securities, certificates, admission tickets or various tickets, and also has an image that cannot be confirmed without using a special appraisal device or the like. The present invention relates to an image forming body.

  With the recent development of digital devices such as scanners, printers, and color copiers, it has become possible to easily make elaborate copies of precious printed matter. As one of the countermeasures, many methods using a metameric pair ink applying metamerism have been tried. The method for visually distinguishing precious printed matter using metameric pair ink is that the ink is judged to have the same color or different hue due to the type of light source to be illuminated and the presence of a filter that transmits a specific wavelength. It is used.

  The above-described metameric pair inks are two types of inks that are recognized as a uniform color under a standard light source but have different spectral transmittances at specific wavelengths with relatively low visibility in the visible light region. The anti-counterfeiting technology and the image forming body formed using this ink have a metameric property so that the pattern can be recognized under a specific light source and a specific wavelength transmission filter (for example, patent documents). 1).

JP 54-159004 A

  However, in the above-mentioned image forming body, the printed matter using the metameric pair ink can be recognized so that the color is different by checking the difference in the light source or the specific wavelength transmission filter. Although there was an effect on the production of the image, the image to be given was poor.

  Further, as a method for imparting a further image, a method of using a material having an absorption characteristic in the infrared region is conceivable, but one color is used by using carbon black for general printing having an absorption characteristic in the infrared region. Although it is possible to set the transmittance of the material to be lower than that of the other color material from the specific wavelength region to the infrared region, it is only possible to give the same image in two regions.

  In recent years, materials that have almost no color under visible light and have absorption characteristics in the infrared region are commercially available. By using this material, two different images can be given to the specific wavelength region and the infrared region. However, the above-described infrared absorbing material is very expensive, and it has been considered difficult to adopt it for a wide range of products from the viewpoint of cost performance. Therefore, there has been a demand for a method for applying the above-described two types of images using only inexpensive materials.

  The present invention has been considered in view of the above points, and using two or more kinds of coloring materials using a general coloring material, and two or more kinds of coloring materials having metamerism in a specific wavelength region, It is a problem to provide metamerism even in an infrared region different from the specific wavelength region, and to combine two types of the image in the specific wavelength region and the image in the infrared region.

  In addition, by inventing an image forming body that is formed using only a general material and has metamerism even in an infrared region different from the above-described specific wavelength region, other anti-counterfeiting magnetic characteristics and / or It was also a problem to provide a more advanced anti-counterfeiting technology in combination with the light emission characteristics.

  As a means for solving the problem of the present invention, in an image forming body in which at least two kinds of color materials are used on a base material and at least two kinds of images are formed by two kinds of color materials, Among the color materials and images, the first image is formed by the first color material, the second image is formed by the second color material, and the first image and the second image are at least partially overlapped. The first image and the second image have a spectral transmittance difference within 10% in the wavelength region of 400 to 600 nm, and the first image has a spectral difference in the wavelength region of 620 to 680 nm. The second image includes a region whose transmittance is 20% or more higher than that of the second image, and the second image includes a region whose spectral transmittance is 20% or more higher than that of the first image in the wavelength region of 820 to 880 nm. As an image forming body That.

  Of the above-described at least two kinds of color materials, the first color material includes a material having an absorption characteristic in the infrared region, and the second color material does not include a material having an absorption characteristic in the infrared region. It is an image forming body.

  Further, the image forming body is characterized in that the first color material and / or the second color material is an ink.

  In addition, the image forming body includes a light emitting material and / or a magnetic material in a part or all of the at least two kinds of color materials.

  Since the image forming body of the present invention can reverse the spectral transmittance in two regions without using a high-grade material, copying using a digital device such as a scanner, a printer, and a color copy is extremely difficult. In addition, even if forgery regarding one of the wavelength regions can be performed, it is possible to provide an advanced anti-counterfeiting technology in which it is impossible to design two wavelength regions in the same manner.

  In addition, since it is an inexpensive image forming body composed of only general materials, it can be easily combined with other functional materials, and an image forming body with multiple images and anti-counterfeiting technology is produced. There is an effect that can be done.

A mode for carrying out the present invention will be described. The image forming body of the present invention uses at least two kinds of color materials for the base material, but the first color material has a transmittance of 20% than the second color material when the wavelength region is 620 to 680 nm. When the wavelength region is 820 to 880 nm, the transmittance of the first color material is 20% or more lower than that of the second color material.

  Hereinafter, the present invention will be described with reference to the drawings. For the color material, an ink most suitable for the present invention was used. FIG. 1 is a diagram showing a blending table of the first ink and the second ink, FIG. 2 is an example showing a spectral spectrum of the first ink and the second ink, and FIG. 3 is an image formation under a standard light source. FIG. 4 shows an example of a body. FIG. 4 shows an image using a filter that cuts off 650 nm or less, and FIG.

  The production of ink will be described with reference to FIG. The first ink uses any one of dioxazine-based, quinacridone-based, and cobalt chloride compounds such as a condensate of chloranil and 3-amino-9-carbazole that transmits in the vicinity of 600 nm, and has absorption characteristics in the infrared region. 0.8% by weight of carbon black is added, and the transmittance in the infrared region after 620 to 680 nm is set to around 50%.

  As the second ink, 3% by weight of a copper phthalocyanine-based material that absorbs light at 600 to 750 nm and transmits in the infrared region was added, and the transmittance at 620 to 680 nm was set to around 10%. In addition, the material used for the second ink is produced using only a material that does not include absorption characteristics in the infrared region.

  The image forming body (1) using the first ink and the second ink will be described with reference to FIG. A first image constituting a star-shaped image (A) is arranged on a substrate using the second ink, and a background image (B An image forming body in which the second image constituting the structure is disposed was prepared.

Here, the first image and the second image are arranged so as not to overlap at all. However, in order to carry out the present invention, an area where at least a part of the first image and the second image do not overlap each other. If there is an arrangement, there may be an overlapping area. In addition, the first ink and the second ink used for the printed matter in FIG. 3 have a spectral transmittance difference of 10% or less in the wavelength region of 400 to 600 nm, and are recognized as the same color by the naked eye. Brown ink is used.

The spectral transmittance of the first image and the second image and the visibility of the image in each wavelength region will be described with reference to FIGS. First, in FIG. 2, in the region where the wavelength region is 620 to 680 nm where human visibility is low, the transmittance of the first image is around 50% (12), and the transmittance of the second image is 10% ( 13), because of the difference in transmittance between the two images, the first image is recognized as faint and the second image is recognized as dark. Therefore, as shown in FIG. Only the part A) is recognized as an image.

  Further, in a wavelength range of 820 to 880 nm that cannot be confirmed without using a special identification device or the like, the transmittance in the first image is around 50% (15), and the transmittance in the second image is 90%. By the above (14), the first image is recognized as being dark and the second image is recognized as being pale due to the difference in transmittance between the two images. Only the portion arranged in the background image (B) is recognized, and the star-shaped image is confirmed as white.

  As an example of the machine reading method in the image forming body (1) described above, reading is performed based on the difference in spectral transmittance between the first image and the second image when the wavelength region in FIG. 2 is 650 nm (10). Method, reading method based on the difference in spectral transmittance between the first image and the second image when the wavelength region is 850 nm (11), and the first method when the above two regions (10) and (11) are used. A method of reading by combining the difference in spectral transmittance between the first image and the second image is conceivable, but the method is not limited to this as long as reading is possible.

  Note that the difference in spectral transmittance between the first image and the second image can be read if there is a difference of 20% or more in consideration of machine readability in each wavelength region of 620 to 680 nm and 820 to 880 nm. Although it is possible, considering the visibility of the image, it is preferably about 40%.

  In addition, a method using a color material having a hue different from that of the base material, a method using a color material having the same color as the base material, and the above-described image forming body, the spectral transmittance is 90% or more from the vicinity of 600 nm to the infrared region. The same effect can be obtained even if overprinting is performed on the above-described image forming body as long as it is a penetrating ink.

  In addition, the color material used in the image forming body of the present invention is not limited to the above-described ink, but a method using a thermal transfer material, a method of including the material in a base material, a method of using as a powdered material, and the like can be considered. However, the present invention is not limited to these as long as the color material can reproduce the spectral transmittance.

  Examples of the present invention will be described below with reference to the drawings. However, the embodiments of the present invention are not limited to the following examples, and may be within the scope of the technology described in the claims. For example, it is possible to appropriately change the embodiment of the invention.

(Example 1)
As an example of the present invention, an image forming body using two kinds of color materials was produced by offset printing. About the above-mentioned two kinds of color materials, the brown ink of the same color is used, and the image forming body (1) using the same will be described with reference to FIGS. The spectral transmittances in FIG. 2 are the spectral spectra of the two types of inks used in this printed matter (1). Using the spectrophotometer “U-4100” manufactured by Hitachi High-Technologies Corporation, the spectral transmittance was measured. Measurements were made.

Although the above-mentioned spectrophotometer is used to measure the spectral transmittance, a similar spectral spectrum is obtained even if the spectral reflectance measurement is performed, and all of the transmittance described in this application is a reflectance. Can also be replaced.

  For the above two types of ink, the first ink uses a blue or purple material whose spectral transmittance turns to transmission at around 600 nm, and the other materials have absorption characteristics in the red pigment, yellow pigment and infrared regions. It was produced using a material having

  The second ink was prepared using a copper phthalocyanine pigment whose spectral transmittance turned to transmission at around 750 nm, and other materials were prepared using a red pigment, a yellow pigment and a blue pigment. All of the materials contained in this ink are materials that do not contain absorption properties in the infrared region.

  The printed material (1) in FIG. 3 is an image forming body (1) using the above-described two types of ink. The star-shaped image (A) that appears due to the difference in transmittance in the wavelength region 650 nm (10) of the printed material (1) uses the second ink and appears due to the difference in transmittance in the wavelength region 850 nm (11). The first ink was used for images (B) other than the star shape.

  As shown in FIG. 2, the two types of ink described above are recognized as brown of the same color by the naked eye, but the transmittance of the first ink is about 50% (12) in the wavelength region of 650 nm (10), The transmittance of the second ink is about 10% (13), and the difference in transmittance between the two types of ink is about 40%. In the wavelength region of 850 nm (11), the transmittance of the first ink is about 50% (15), the transmittance of the second ink is 90% or more (14), and the transmittance of the two types of inks The difference is about 40%.

  When this printed matter (1) is viewed visually, a specific image cannot be confirmed and is recognized as a square of one color, but when a sharp cut filter manufactured by Fuji Film Co., Ltd. that cuts a light source of 650 nm or less is interposed, A star-shaped image (A) is confirmed. In addition, when a sharp cut filter manufactured by Fuji Film Co., Ltd. that cuts a light source of 850 nm or less is interposed, only the background portion surrounding the star-shaped image is visually recognized, so that a star-shaped image (A) is white. I can confirm.

  The above two inks are preferably of the same color under a standard light source, but the above-mentioned spectral transmittance is reproduced even when two or more types of inks are used and inks of different hues are used under a standard light source. The same effect is obtained.

  In addition, at least two kinds of inks described above are printed on the substrate, but the printing method is not particularly limited to the printing method, such as intaglio, relief printing, lithographic printing, gravure, screen, flexo, etc. If the difference in transmittance can be reproduced, various printing methods can be used, and the machine reading is performed using the difference in transmittance in the wavelength region 650 nm (10) and the difference in transmittance in the wavelength region 850 nm (11). It is also possible to perform.

  In addition, although the hues of the first and second inks are brown, the invention is not limited to this as long as the spectral transmittance of each ink can be set within the above-mentioned range, and the same applies to hues of orange, red, purple, etc. Get effect (not shown).

(Example 2)
The image forming body (4) in FIG. 8 was produced by offset printing using three types of ink of the same color. This printed matter (4) formed an image called copy (C) with the first ink and an image called copy (E) with the second ink. Moreover, it is a printed matter (4) which prints a part other than the image formed by the first ink and the second ink with the third ink and is confirmed as a solid background of one color under a standard light source.

The blending ratio of these three types of ink is shown in FIG. The first and second inks were slightly different from the first and second inks of Example 1, but the transmittance difference in each region of 620 to 680 nm and 820 to 880 nm was about 30%. Was set as follows. In addition, the third ink is made of any one of dioxazine-based, quinacridone-based, and cobalt chloride compounds such as a condensate of chloranil and 3-amino-9-carbazole that transmits at around 600 nm as in the first ink. The remaining pigment used was composed of a material that did not contain absorption properties in the infrared region.

The spectral transmittance of the above three types of ink will be described with reference to FIG. The first and second inks are the same as the spectral transmittance of Example 1, the spectral transmittance of the third ink is about 60% when the wavelength region is 650 nm (10) (12), The light transmittance was designed to be about 90% (14) when the wavelength region was 850 nm (11).

  Since the spectral transmittance of the above-mentioned three types of ink is within a range of 10% or less in the wavelength region of 400 to 600 nm, when this printed matter (4) is visually confirmed, one color as shown in FIG. However, when the wavelength region is 650 nm (10), the transmittance of the first ink and the third ink is about 60% (12), and the transmittance of the second ink is 30. % (13), the density difference between the first and third inks and the second ink confirms that the part using the second ink as shown in FIG. The

When the wavelength region is 850 nm (11), the transmittance of the second ink and the third ink is equal to about 90% (14), and the transmittance of the first ink is about 60% (15). Accordingly, from the density difference between the second and third inks and the first ink, the portion using the first ink as shown in FIG. 10 is confirmed as an image (E) of copying.

From this, the printed matter (4) has a density difference between the first and third inks and the second ink when the solid color (D) of one color under the standard light source and the wavelength region is 650 nm (10). The image of the copy (C) consisting of the above and three different images of the copy (E) consisting of the density difference between the second and third inks and the first ink when the wavelength region is 850 nm (11) can be confirmed.

  Since the image forming bodies (1) and (4) of Example 1 and Example 2 can be applied as a background pattern and a background pattern, the title, the forehead, personal information, and the like are overprinted in the same manner as a normal printed matter. It is possible. However, those that completely hide the surface of the image forming body are not included.

  Further, regarding the ink for overprinting described above, if the spectral transmittance from the wavelength region near 600 nm is higher than the transmittance of the first ink in Examples 1 and 2, the image is completely hidden. However, it is possible to perform overprinting as a printing substrate regardless of the printing method (not shown).

  It is also possible to use light emitting materials such as fluorescent, phosphorescent, animal light, and infrared light emitting materials in combination with the first, second and / or third inks described above. For example, light is emitted to cyan, magenta and yellow. By using the material to be used in the first, second and third inks in combination, it is possible to produce a printed material having a full-color fluorescent image (not shown).

Example 3
The printed material (7) in FIG. 13 is a magnetic material that has the base material of the printed material (4) in FIG. 8 on which a solid pattern is applied with three types of ink of the same color as in Example 2, and has no absorption characteristics in the infrared region. It is a printed matter (7) obtained by overprinting (F) the fourth ink containing, and is visually confirmed as a printed matter (7) in which the fourth ink forms an image on a brown solid background.

The above-mentioned fourth ink was an intaglio ink and was prepared at a blending ratio shown in FIG. The magnetic material and pigment contained in the fourth ink were materials that did not contain absorption characteristics in the infrared region. The spectral transmittance will be described with reference to FIG. When the hue of the fourth ink is orange, the spectral transmittance is changed to transmission from around 600 nm, and when the wavelength region is 650 nm (10) and the wavelength region is 850 nm (11), the transmittance is 90%. This is the ink as described above.

This fourth ink has a metamerism because the transmittance in two regions (10) and (11) where the first, second and third inks form an image is 90% or more. Even if the first, second, and third inks are completely hidden, the first, second, and third inks are not obstructed without hindering the appearance of images in the two regions (10) and (11). Since light is transmitted to the printed background image, there is almost no influence on the image revealing effect.

  When this printed matter (7) is viewed under a standard light source, it is recognized as a printed matter (7) having an orange intaglio printing (F) on a brown tint block print. However, the wavelength region is 650 nm (10) and the wavelength region is 850 nm. In (11), since the spectral transmittance of the intaglio ink is 90% or more, only the image (C) as a copy is confirmed in the wavelength region 650 nm (10) as shown in FIG. 14, and the wavelength region 850 nm ( 11), only the image (E) of copying is confirmed as shown in FIG.

  In addition, since a magnetic material is used for the fourth ink in the printed matter (7) described above, as a mechanical reading method of the printed matter (7), a reading method based on magnetic characteristics, a wavelength region is 650 nm (10). The method of reading by the difference in spectral transmittance between the first ink and the second ink and the method of reading by the difference in spectral transmittance between the first ink and the second ink when the wavelength region is 850 nm (11), etc. Is possible and comprises a plurality of machine reading information.

  The fourth ink is an orange intaglio ink, but is not limited to this as long as the hue and plate type can set the transmittance to 90% or more from the wavelength region near 600 nm to the infrared region, The same effect can be obtained with brown, red, crimson, etc. with respect to hue, and with offset, screen, flexo, etc. with respect to plate type (not shown).

Example 4
FIG. 16 is an enlarged view of a halftone dot region of a printed material on which a gradation image is formed by a halftone dot using the first and second inks used in the first embodiment. In this printed matter, a halftone dot area using the first ink and a halftone dot area using the second ink are arbitrarily arranged. A toned image is formed (not shown).

In this printed matter, since the halftone dot region using the first ink and the halftone dot region using the second ink are arranged so as not to overlap, each wavelength of 620 to 680 nm and 820 to 880 nm In the area, machine reading can be performed in a halftone dot area (16) using only the first ink and a halftone dot area (17) using only the second ink.

It should be noted that at least a part of the first image region (16) and the second image region (17) are arranged on the printed matter shown in FIG. An area (20) in which the independent halftone dots of the portion (18) where the two kinds of images overlap are mixed without overlapping, and an independent network. The region in which some of the dots are overlapped is not included in (21) the arrangement in which at least some of the two types of images do not overlap in the present invention.

In addition, since the above-mentioned printed matter uses the same color ink, it is a gradation image by being recognized as a shade by overlapping the density of halftone dots and two types of halftone dots. If there is an area that does not overlap a part of the halftone dot area used and the halftone dot area using the second ink, full-color printing using the process ink is also possible (not shown).

In Example 4, a printed material was produced using halftone dots, but the printed material is not limited to this as long as a printed material arranged so that at least a part of two types of images does not overlap can be produced.

The figure which shows the mixture ratio of the coloring material of this invention The figure which shows the spectrum of at least 2 types of coloring materials required for this invention 1 is a diagram illustrating an example of an image forming body according to the present invention and Example 1. FIG. FIG. 2 shows a case where the image forming body of FIG. 2 is confirmed in a wavelength region of 650 nm. FIG. 2 is a diagram when the image forming body of FIG. 2 is confirmed in a wavelength region of 850 nm. The figure which shows the mixture ratio of the ink used for Example 2 The figure which shows the spectral spectrum of the coloring material used for Example 2 The figure which shows the image forming body of Example 2. The figure when the image forming body of FIG. 8 is confirmed in a wavelength region of 650 nm The figure when the image forming body of FIG. 8 is confirmed in a wavelength region of 850 nm The figure which shows the mixture ratio of the ink used for Example 3 The figure which shows the spectral spectrum of the coloring material used for Example 3 The figure which shows the image forming body of Example 3. The figure when the image forming body of FIG. 13 is confirmed in a wavelength region of 650 nm The figure when the image forming body of FIG. 13 is confirmed in a wavelength region of 850 nm The figure which shows the halftone dot area | region of Example 4. FIG. The figure which shows an example of the enlarged view of the part which two types of images of FIG. 16 overlap

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming body 2 of Example 1 650 nm image of Example 1 850 nm image of Example 1 4 Image forming body 5 of Example 2 650 nm image of Example 2 850 nm image of Example 2 7 Image forming body 8 of Example 3 650 nm image of Example 3 850 nm image of Example 3 Part 11 showing 650 nm part 11 Part showing 850 nm Part 12 showing part 850 nm Transmittance of part showing 650 nm is around 50% The transmittance of the portion showing 13 wavelength region of 650 nm is near 10% The transmittance of the portion showing 850 nm in the 14 wavelength region is near 90% The transmittance of the portion showing 850 nm in the 15 wavelength region is near 50% 16 The first ink was used. Halftone dot region 17 Halftone dot region 18 using the second ink Halftone dot region 19 in which the first ink and the halftone dot region using the second ink are arranged to overlap each other FIG. 20 showing the dot area FIG. 21 showing that the independent halftone dots overlap each other FIG. 21 showing that the independent halftone dots are mixed without overlapping each other A image B by the second ink of Example 1 Example Image C with 1st ink of 1 Image D with 2nd ink of Examples 2 and 3 Image E with 1st ink of Examples 2 and 3 Image F with 3rd ink of Examples 2 and 3 Example Image with the fourth ink of 3

Claims (4)

On the base material, at least two kinds of color materials are used, and in the image forming body in which at least two kinds of images are formed by the two kinds of color materials,
Of the two types of color materials and images, a first image is formed by a first color material, a second image is formed by a second color material, and the first image and the second image are formed. Are arranged such that at least a part thereof does not overlap, the first image and the second image have a spectral transmittance difference within 10% in a wavelength region of 400 to 600 nm, and the first image is The spectral transmittance in the wavelength region of 620 to 680 nm is 20% or higher than that of the second image, and the second image has the spectral transmittance in the wavelength region of 820 to 880 nm. An image forming body comprising an area 20% or more higher than the above image.   Of the at least two kinds of color materials, the first color material includes a material having an absorption characteristic in an infrared region, and the second color material does not include a material having an absorption characteristic in an infrared region. The image forming body according to claim 1.   The image forming body according to claim 1, wherein the first color material and / or the second color material is ink. 4. The image forming body according to claim 1, wherein a part or all of the at least two or more kinds of color materials include a light emitting material and / or a magnetic material.

Images