JP4418881B2 - Anti-counterfeit printed matter - Google Patents

Description

  The present invention makes it difficult to forge a printed matter such as securities, certificates, admission tickets or various tickets by a color copier or personal computer and a color printer, and can be identified only under specific conditions. The present invention relates to a printed matter printed with indistinguishable ink.

  Even for colors with different spectral reflectances as anti-counterfeit prints, the colors may be the same depending on the lighting conditions, but colors that are the same color under a certain illumination light source appear to be completely different under other light sources with a different spectral energy distribution The phenomenon is called metamerism.

  Applying this principle of metamerism, using two or more types of inks with different spectral reflectance wavelength peaks, each ink color is almost the same under natural light. Anti-counterfeit prints in which ink is reproduced in different colors are well known. However, with the advancement of digital technology, printed materials can be easily copied.

  On the other hand, since the fluorescent light-emitting ink emits light by ultraviolet rays, printed matter using the fluorescent light-emitting ink has a high anti-counterfeiting effect on a color copying machine or the like, and is used in many securities. In recent years, however, counterfeit printed matter using even fluorescent light-emitting ink has begun to appear, and it has become impossible to expect a great anti-counterfeit effect simply by the function of emitting fluorescence by ultraviolet rays.

  Conventionally, as a printing method for preventing counterfeiting, an invention relating to the double confidential printing method having the following contents has already been proposed (see Patent Document 1). In this double confidential printing method, the first type printing surface is configured with a blue light emitting material, and the second type printing surface is configured with a red light emitting material. The first-type printing surface and the second-type printing surface need not occupy separate spaces, and may be overprinted.

  Here, the blue light-emitting substance is invisible under daylight, has a main peak of the excitation wavelength spectrum in the range of 200 to 400 nm, and has a main peak of the emission wavelength spectrum in the range of 400 to 450 nm. Or it is a substance which has this.

  The red light-emitting substance is invisible under daylight, has a main peak of the excitation wavelength spectrum in the range of 200 to 400 nm, and has a main peak of the emission wavelength spectrum in the range of 500 to 650 nm, or It is a substance having this.

  According to such a double confidential printing method, it is invisible under daylight, and under ultraviolet irradiation, the blue luminance covers the red luminance so that only blue appears at first glance. Although the identification is impossible, the display on the second type printing surface can be identified only with a filter that shields the wavelength of 500 nm or less.

Japanese Patent Laid-Open No. 50-6410

By the way, according to the method described in Patent Document 1, the blue light intensity covers the red light intensity so that only blue can be seen at a glance under ultraviolet irradiation. It is possible. Therefore, when the first type printing surface and the second type printing surface are overprinted, since the printing areas overlap, the phenomenon that the blue luminance covers the red luminance and only blue at first glance is likely to occur.
However, when the first-type printing surface and the second-type printing surface occupy separate spaces, that is, when the first-type printing surface and the second-type printing surface are printed in a shifted manner in the same plane, Depending on the size and how it is shifted, the phenomenon that the brightness of blue completely covers the brightness of red that is adjacent in a plane is not necessarily generated. There was a problem that the effect of “distinguishable” could not be sufficiently achieved.

The present invention has been made to solve the above-described problems, and an object of the present invention is to prevent counterfeit printed materials from entering the market due to the recent advancement of copying and copying technologies, and It is intended to strengthen the anti-counterfeiting effect by commercializing fluorescent light-emitting inks that are effective in preventing counterfeiting against the advancement of digital technology, etc., and further enhancing the anti-counterfeiting technology for counterfeit printed matter using fluorescent light-emitting inks. is there.

  In particular, even if the first type printing surface and the second type printing surface, which are problematic in the technology of Patent Document 1, are printed on the same plane, they cannot be distinguished from each other under ultraviolet irradiation. The configuration can be realized.

  The present invention has two or more print areas, and at least two of the two or more print areas are printed products that are printed with different fluorescent light-emitting inks, and at least two of the fluorescent light-emitting inks. The seeds provide a printed matter which is an ink which is visually colorless or has the same color under natural light and has a different fluorescence emission spectrum under irradiation of energy for exciting light emission but has the same color visually.

  The present invention provides a printed matter in which at least one of the fluorescent light-emitting inks is an ink having a fluorescent light emission spectrum exhibiting at least two or more peaks.

  The present invention provides a printed matter characterized in that at least one of the fluorescent light-emitting inks is an ink having a fluorescent light emission spectrum showing at least two or more peaks in the visible wavelength region.

  The present invention provides a printed matter in which at least one fluorescent light-emitting ink is an ink containing two or more fluorescent pigments.

  The present invention provides a printed matter in which two or more fluorescent pigments are pigments having fluorescent emission spectra that show peaks in different wavelength ranges.

  The present invention provides a printed matter in which two or more fluorescent pigments are pigments each having a fluorescence emission spectrum having peaks in different wavelength ranges in the visible wavelength range.

  In addition to the fact that the use of the fluorescent light-emitting ink itself is one forgery prevention, the printed matter of the present invention has two or more types of fluorescent light-emitting ink printed areas, but the fluorescent light-emitting color is under ultraviolet irradiation. Double anti-counterfeit measures that can be confirmed with the same color and that can identify each ink through a filter or the like are provided, which further enhances anti-counterfeiting.

Information such as characters, symbols, and barcodes given to the printed matter of the present invention cannot be visually discerned because two or more kinds of fluorescent light-emitting inks used are colorless or the same color under natural light and when irradiated with ultraviolet rays. By using a color filter, for example, a green filter, information can be identified instantly and easily, and it is highly practical as an anti-counterfeit printed matter.

In the printed matter of the present invention, the brightness of the first print area covers the brightness of the second print area and does not appear to be the same color at first, but the first print area and the second print area fluoresce in the same color. It is difficult to identify time information, and it is possible to give relatively free information.

  The ink used in the present invention exhibits a special anti-counterfeiting function that will be described in detail below. Naturally, it is a normally sold ink or toner used in a copying machine or a personal computer. Since different things will be used, they cannot be imitated easily.

  The best mode for carrying out the present invention will be described below with reference to the drawings based on the embodiments.

  The 1st printing area | region 1 is printed on the base material using 1st ink, and the 2nd printing area | region 2 is printed on the same base material using 2nd ink, and printed matter is obtained. For example, the first printing area 1 and the second printing area 2 as shown in FIGS. 1A and 1B are printed on the substrate 5 using the first ink as shown in FIG. The printed matter A is obtained by printing the region 1 ′ and the second printing region 2 ′ using the second ink.

  The first ink emits excited light when irradiated with light mainly in the wavelength range of 200 nm to 320 nm, and is an ultraviolet excited visible light emitting pigment having a structure of CaSiO3: Mn, Pb (fluorescence that emits light in a visible state when excited by ultraviolet light). Pigment) is used to make the first pigment.

  This first pigment exhibits a fluorescence emission spectrum that emits orange light in the visible region as shown in FIG. 5 when irradiated with ultraviolet rays in the above wavelength region. The first ink containing such a first pigment is colorless under natural light in the visible region, but exhibits a fluorescence emission spectrum 13 in FIG. 8 when irradiated with ultraviolet rays, and emits orange light.

  The second ink emits excitation light when irradiated mainly with light having an excitation wavelength range of 200 nm to 320 nm, and two kinds of ultraviolet excitation visible light emitting pigments (excited by ultraviolet rays) having a structure of Zn2SiO4: Mn and Y2O3: Eu. And a “second pigment” and a “third pigment” which are fluorescent pigments that emit light in a visible state.

  The second pigment and the third pigment show fluorescence emission spectra 11 and 12 that emit yellow-green and red light in the visible region as shown in FIGS. . Like the first ink, the second ink containing the second pigment and the third pigment is colorless under natural light in the visible region, but the fluorescence in FIG. An emission spectrum 14 is shown.

  Since the second ink contains the second pigment and the third pigment, the fluorescence emission spectrum 14 has a peak in the emission intensity of each of yellow-green and red. In addition, the second ink has an appropriate amount of the second pigment and the third pigment so that these luminescent colors are additively mixed and appear to exhibit the same color as the orange luminescent color of the first ink. Made by blending.

  A blending example of the first ink is shown in Table 1, and a blending example of the second ink is shown in Table 2.

(Function)
Since the first ink and the second ink used for printing the first print region 1 ′ and the second print region 2 ′ of the printed matter A shown in FIG. 2 are both colorless under the natural light that is the visible region, The first print area 1 ′ and the second print area 2 ′ are invisible under natural light, and the first print area 1 ′ and the second print area 2 ′ cannot be distinguished from each other.

  The printed matter A is irradiated with ultraviolet rays, specifically, with the excitation wavelength of the fluorescent pigment used in the present embodiment being 200 nm to 320 nm, and thus usually 254 nm ultraviolet rays, which are called short wave ultraviolet rays, are irradiated. Then, since the first ink and the second ink are mixed with pigments so as to emit light with the same color in orange as described above, the first printing area and the second printing area appear to be the same color, and FIG. Only one print area 7 as shown in FIG.

  When the printed matter A is confirmed through a general green filter or blue filter having the spectral spectrum 15 or the spectral spectrum 16 as shown in FIG. 9 under such ultraviolet irradiation, as shown in FIG. Can be confirmed as the first print area 1a and the second print area 2a exhibiting different colors.

  For example, the case where the printed matter A is observed using a green filter will be described in more detail. The green filter is indicated by a spectral spectrum 15 in FIG. 9 and exhibits relatively high transmission characteristics for light in the wavelength region of 470 to 600 nm, but light in other wavelength regions (excluding wavelength regions exceeding 700 nm). Shows low transmission characteristics (however, the transmittance is not 0%), and the transmission is relatively suppressed.

  Therefore, when the printed matter A is observed through the green filter, the first ink showing the fluorescence emission spectrum 13 and the second ink showing the fluorescence emission spectrum 14 in FIG. 8 are shown in FIG. 10 (the emission intensity scale of FIG. Are different from each other). Fluorescence emission spectrum 17 and fluorescence emission spectrum 18 are shown.

  Comparing the fluorescence emission spectrum 14 before passing through the filter (see FIG. 8) and the fluorescence emission spectrum 18 passing through the filter (see FIG. 10) with respect to the second ink, peaks P1 and P2 (see FIG. 8) on the left and right, respectively. P1 ′ and P2 ′ (see FIG. 10) are shown, but the balance between the left and right peaks changes, and the fluorescence emission spectrum 18 has a left peak P1 ′ with respect to the right peak P2 ′. Since it seems to have risen relatively, the second printing area 2a has a greenishness and is seen as yellowish green. In addition, about the 1st ink, in the fluorescence emission spectrum 17, green is added to orange. In this way, the first print area 1a and the second print area 2a appear to have different colors, so that the areas can be distinguished and confirmed.

  As specifically understood from the above embodiments, the essence of the present invention is that the same stimulus is used for two or more types of inks even if the fluorescence emission spectra are different (see spectra 13 and 14 in FIG. 8). At least one kind of ink (second ink in the embodiment) is adjusted using an additive color mixture of two or more kinds of fluorescent pigments so that the fluorescent light emission is seen through a filter. The spectrum is observed as light of different fluorescence emission spectra (see spectra 17 and 18 in FIG. 10), and the same stimulus is not received by the eyes, and the principle that the above two or more types of inks are recognized as different colors. It is in the configuration used.

  Thus, the feature of the present invention is that at least one of a plurality of different areas is printed with an ink having two or more fluorescent pigments, and the ink in this area is different from the ink printed on the other areas. It is colorless or the same color under natural light, appears the same color under ultraviolet irradiation, and can be observed as a different color when passing through a filter that shields a specific wavelength under ultraviolet irradiation. Therefore, as long as it can be observed in this way, the combination of the ink in the one region and the ink in the other region is not limited, and is not limited to the ink having the above-described emission color in this embodiment.

  By the way, in this embodiment, one of the two areas is printed with an ink having one kind of fluorescent pigment, and the other area is printed with an ink having two or more kinds of fluorescent pigment. Even if it is not such a configuration, as long as at least one of the plurality of different regions is printed with an ink having two or more types of fluorescent pigments, the fluorescent pigment in each of the two or more different regions It may be a printed matter printed with an ink having two or more.

  According to the present invention, it is possible to obtain a bar code printed material that is extremely difficult to counterfeit by using two types of inks each having a fluorescence emission spectrum having a characteristic peak. That is, a bar code is produced by mixing image lines printed with the first ink and the second ink each having a fluorescence emission spectrum showing a characteristic peak.

  This bar code is a single type of bar code pattern under natural light and simply in a fluorescent state. However, the bar code pattern detected for each filter can be detected by using a plurality of band pass filters. In contrast, it is a printed matter that is capable of complex machine reading.

  As mentioned above, although embodiment of the printed matter based on this invention was described based on the Example, this invention is not specifically limited to such an Example. Each printed area may be adjacent, separated, or partially overlapped. Excitation light emission energy is not limited to ultraviolet rays, and infrared rays and electron beams are used. Of course, an ink using a material that emits light by the energy of the above may be used, and there are various embodiments within the scope of the technical matters described in the claims.

  Since the present invention has the above-described configuration, it can be applied to a printed matter to which banknotes, certificates, identification cards, passports, cards, barcodes, and other confidential information are given.

It is the figure which showed the printing area | region of the printed matter of this invention. It is a figure of the state which observed the printed matter of this invention under natural light. It is a figure of the state which irradiated and irradiated the ultraviolet-ray to the printed matter of this invention. It is a figure of the state which irradiated the ultraviolet-ray to the printed matter of this invention, and also observed through the filter. It is the figure which showed the fluorescence emission spectrum of the fluorescent pigment 1. FIG. It is the figure which showed the fluorescence emission spectrum of the fluorescent pigment 2. It is the figure which showed the fluorescence emission spectrum of the fluorescent pigment 3. It is the figure which showed the fluorescence emission spectrum of 1st ink and 2nd ink. It is the figure which showed the spectral spectrum of the green filter and the blue filter. It is the figure which showed the fluorescence emission spectrum when the 1st ink and 2nd ink which are emitting fluorescence are observed through a filter.

Explanation of symbols

1 First print area
1 'first print area under natural light
1a First printing area when irradiated with ultraviolet rays
2 Second printing area
2 'Second print area under natural light
2a Second printing area during UV irradiation
3 Natural light source
4 viewpoints (eyes)
5 Base material
6 UV light source
7 Area that emits light when irradiated with ultraviolet rays
9 Filter
10 Fluorescence emission spectrum of fluorescent pigment 1
11 Fluorescence emission spectrum of fluorescent pigment 2
12 Fluorescence emission spectrum of fluorescent pigment 3
13 Fluorescence emission spectrum of the first ink
14 Fluorescence emission spectrum of the second ink
15 Spectral spectrum of green filter
16 Spectral spectrum of blue filter
17 Fluorescence emission spectrum of the first ink through the green filter 18 Fluorescence emission spectrum of the second ink through the green filter A Printed Example

Claims (6)

A printed material in which at least a first print area and a second print area are formed on a substrate,
Either one of the first print area or the second print area is formed by a first fluorescent light-emitting ink, and the other of the first print area or the second print area is a second fluorescent light-emitting ink. Formed by
The first fluorescent light-emitting ink and the second fluorescent light-emitting ink are visually recognized as colorless or the same color under natural light, and are visually recognized as the same color of emitted light under irradiation of excitation light emission energy,
The first fluorescent light emitting ink and the second fluorescent light emitting ink have different emission spectra;
The first printed area and the second printed area are visually recognized as different hues by irradiating the printed matter with excitation light emission energy in the two fluorescent light emitting inks and interposing a discriminator. Characteristic printed matter. The printed matter according to claim 1, wherein the first fluorescent light-emitting ink has a fluorescent light emission spectrum having at least two or more light emission peaks. The printed matter according to claim 1 or 2 , wherein an emission spectrum showing at least two or more emission peaks according to claim 2 is formed in a visible wavelength region . The printed matter according to any one of claims 1 to 3 , wherein the first fluorescent light-emitting ink is an ink containing two or more fluorescent pigments. The two or more fluorescent pigments in the first fluorescence ink, printed matter according to any one of claims 1 to 4, characterized in that a pigment having a fluorescence emission spectrum having a peak in a different wavelength ranges, respectively . The printed matter according to claim 5, wherein different emission wavelengths in the fluorescent pigment according to claim 5 are formed in a visible wavelength range.

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