JP3624246B2 - Multicolored printed matter and printing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multicolor printed material that can be visually recognized but that can obtain an image having a full-color gradation by being irradiated with ultraviolet rays, and a printing method therefor.
[0002]
[Prior art]
Conventionally, colorless fluorescent inks are used for the purpose of preventing forgery and copying, and printing using the ink is not based on a halftone dot pattern, but a delicate pattern such as a line drawing or a solid pattern or a special pattern. Most of the prints are monochrome prints and gradation-free prints, and with such fluorescent printing, anti-counterfeiting resistance has been reduced, so the development of more advanced anti-counterfeiting measures is desired. As a measure, a method of forming a full-color image using two or more kinds of inks each containing a dye that emits light by ultraviolet irradiation and having different emission colors (Japanese Patent Laid-Open No. 7-125403: “Image Forming Method”) ) And a method of printing a gradation image such as a face photograph using colorless fluorescent ink on a card surface (Japanese Utility Model Publication No. 7-53987: “Image card with colorless fluorescent light”) and the like.
[0003]
The principle of additive color mixing of R (red), G (green), and B (blue) light emission is widely used for television cathode ray tubes and the like and is generally known.
[0004]
In color printing, a color original is separated into four colors to produce four positive (or negative) films corresponding to Y (yellow), M (magenta), C (cyan), and BK (black). The four positive plates are baked from the positive (net negative), and are sequentially printed on the paper with inks corresponding to the four positive plates.
[0005]
[Problems to be solved by the invention]
From the above, using the principle of additive color mixing of R, G, and B light emission used in conventional television cathode ray tubes, full-color images can be obtained using fluorescent ink that emits light to R, G, and B, respectively, by ultraviolet irradiation. Since the phosphor is a light emitter when formed, the overlap of R, G, B3 colors will be white, and the paper or film used as the substrate may be paper even in the absence of ink when irradiated with ultraviolet rays. The film itself was not completely black due to the fluorescence of the film itself and the visible light component of the toll line lamp itself, and the emitted light was diffused, so that the image could not be expressed clearly.
[0006]
In the color printing plate making method, a color original is separated into four colors Y, M, C, and BK to form a film, and a plate is printed and printed with each ink. However, R, G, B The plate-making method when using fluorescent inks that respectively emit light cannot be reproduced by the four-color separation of Y, M, C, and BK, which is the concept of subtractive color mixing.
[0007]
Therefore, the present invention prints a colorless fluorescent ink that emits light to R, G, and B, respectively, when irradiated with ultraviolet light, by printing with ultraviolet absorbing ink that appears colorless or white under normal light, thereby printing gradation in full color. It is an object of the present invention to provide a multicolored printed matter and a printing method for obtaining the same. The printed material obtained by the present invention cannot be normally recognized, and is difficult to duplicate by a normal manufacturing method, and therefore has a high anti-counterfeit effect.
[0008]
[Means for Solving the Problems]
The present invention uses three primary color fluorescent inks that emit light of colorless red, green, and blue colors that cannot be recognized under normal light, and forms a full color image by ultraviolet irradiation. And a UV-absorbing ink that appears to be colorless or white under normal light, the original is captured as an image by the scanner with R, G, and B components, cyan as the cyan component, magenta as the magenta component, and yellow It is decomposed into components composed of yellow as a component and black as a component of black, and only the black component is applied to a printing plate surface for ultraviolet-absorbing ink, and printing is performed with inks that emit light on R, G, and B, respectively. Then, the multicolor printed matter and the printing method are characterized in that ultraviolet absorbing ink is subsequently printed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the ultraviolet light-absorbing ink that appears colorless or white under normal light is printed on the three primary color luminescent inks that emit light of colorless R, G, and B that cannot be recognized under normal light. A full-color image with gradation can be formed by ultraviolet irradiation.
[0010]
【Example】
The substrate used in the present invention uses paper such as fine paper, coated paper, art paper and a transparent film, and absorbs ultraviolet rays as much as possible. The substrate should be transparent or white as much as possible.
[0011]
As the printing method used in the present invention, various printing methods such as offset printing, letterpress printing, and gravure printing are used. In addition, the present invention is a printing in which a colorless fluorescent ink that emits light in each of R, G, and B is printed with an ink that absorbs ultraviolet light that appears to be colorless or white under normal light, and the colorless fluorescent ink is printed first. Thereafter, colorless or white UV-absorbing ink is printed.
[0012]
Since the plate-making method in the present invention uses the three primary colors of fluorescent inks that emit light respectively for R, G, and B, the printing plate surface of the fluorescent ink is obtained by reversing the gradation of normal color printing, and each complementary color. Use it by applying to the color. However, the printing plate surface for the ultraviolet absorbing ink is a black plate having a normal color separation.
[0013]
In general, a cathode ray tube or the like of a television uses a visual trichromaticity to produce a full color by changing the emission intensity of phosphors of three colors R, G, and B. FIG. 1 shows an ideal spectral characteristic of additive color mixture. Is shown. FIG. 2 shows ideal spectral characteristics in subtractive color mixing. FIG. 2A shows cyan ink (C), FIG. 2B shows magenta ink (M), and FIG. c) represents an ideal spectral characteristic of the yellow ink (Y). Ideally, all three colors such as C, M, and Y as described above may be expressed. Actually, the cyan ink (C) in FIG. 3A and the magenta ink in FIG. 3B are used. (M) Since the wavelength characteristic of the reflectance of the ink is different from the ideal as in the yellow ink (Y) in FIG. 3C, in addition to the three colors of Y, M and C in general color printing Black (BK) is used to compensate for the gradation and lack of density in the shadow part from the middle. For this reason, when applying the additive color mixing technique according to the present invention, the present invention uses an ultraviolet absorbing ink to suppress excess light emission from the middle to express the gradation of the shadow part, and It suppresses the reduction in blackness due to its own light emission and scattering, and sharpens the image.
[0014]
Further, in general, in color printing, based on the principle of undercolor removal, a scanner converts the optical density of C, M, and Y in FIG. 4A to the density of x into black (BK) in FIG. 4B. By replacing and stabilizing the gray reproduction by reducing the ink amounts of C, M, and Y, the color balance of the shadow portion is corrected and the image is stabilized. Therefore, also in the present invention, as in the case of this black ink (BK), a more stable image can be obtained by incorporating the principle of the undercolor removal into the ultraviolet absorbing ink.
[0015]
As the pigment used in the colorless fluorescent ink of the present invention, R is a red light emitting fluorescent pigment having an emission wavelength of about 600 to 650 nm, for example, Y ₂ O ₃ : YVO ₄ : Eu, and G has an emission wavelength of 520 to 520 nm. A green light emitting fluorescent pigment of about 545 nm, for example Zn ₂ Sio ₄ , MgAl ₁₁ O ₁₉ : Ce, Tb, etc., and B is a blue light emitting fluorescent pigment having an emission wavelength of about 450 to 490 nm, for example Sr ₂ P ₂ O ₇ : Sn, Sr ₄ Al ₁₄ O ₂₅ : Eu, etc. As the fluorescent pigment used in the present invention, it is necessary to select a colorless pigment under normal visible light that is not irradiated with ultraviolet rays. If it is colorless under visible light, the fluorescent pigment to be used can be either organic or inorganic. If the above conditions are satisfied, use a varnish in which a dye is dissolved instead of the pigment. Is also possible.
[0016]
In addition, UV-absorbing inks that appear colorless or white under normal light can be obtained by mixing colorless benzotriazole-based, benzophenone-based, oxalic anilide-based organic UV absorbers, and white TiO _2. .
[0017]
(Embodiment 1) This embodiment uses normal light for suppressing unnecessary light emission based on the principle of additive color mixing in three primary colors of fluorescent ink that emit light respectively in colorless R, G, and B that cannot be recognized under normal light. Below is an example when printing with a total of four colors by printing UV-absorbing ink that appears colorless or white. FIG. 5A shows a document (P) on which the characters “ABCD” are written. In the character “ABCD”, the character A is cyan (1), the character B is magenta (2), the character C is yellow (3), the character D is black (4), and the base material of the document (P) is White (5). In this case, what constitutes the document (P) may be anything such as characters and designs. Moreover, a character, a design, etc. may overlap. Next, the original (P) is captured as an image with R, G, and B components by a scanner, and the captured character images of the R, G, and B components are converted into characters A and D as cyan components as shown in FIG. 5B. Composed of cyan and black (I), composed of magenta and black of characters B and D as magenta components (II), composed of yellow and black of characters C and D as yellow components The color separation versions (I ′), (II ′), and (III ′) are generated by converting the converted image into the existing one (III), and the gradation is inverted as shown in FIG. Plates (I ′), (II ′), and (III ′) are used as printing plates (not shown) for each member that emit light to R, G, and B. Next, the original (P) in FIG. 5 (a) is again captured as an image with R, G, and B components by the scanner, and is composed of cyan of the letter A as the cyan component as shown in FIG. 5 (d). (I ₁ ), a magenta component composed of the magenta component of the letter B (II ₁ ), a yellow component composed of the yellow of the character C (III ₁ ), a black component of the letter D black (IV ₁ ), each of which is composed of the above, and only the black component (IV ₁ ) is applied to a printing plate surface (not shown) for UV-absorbing ink, and emits light to R, G, and B, respectively. Offset printing is performed using each ink and ultraviolet absorbing ink. At this time, the ultraviolet absorbing ink is printed at the end to emphasize the black portion and sharpen the image.
[0018]
(Embodiment 2) This embodiment uses normal light for suppressing unnecessary light emission based on the principle of additive color mixing in three primary colors of fluorescent ink that emit light in colorless R, G, and B, respectively, which cannot be recognized under normal light. Below is an example in which UV absorbing ink that appears colorless or white is added and printing is performed by incorporating the principle of undercolor removal in plate making. In the same manner as in the first embodiment, the original (P) on which the characters “ABCD” in FIG. 5A are written is captured as an image with R, G, and B components by a scanner, and the captured R, G, and B components are captured. As shown in FIG. 5 (b), the character image of FIG. 5 is composed of cyan of the character A as a cyan component ( I ₁ ), and composed of magenta of the character B as a magenta component ( II ₁ ). what is configured in the yellow character C as yellow component (III _1), converts what is configured in the black letter D as a black component (IV _1), as shown in FIG. 5 (e) said converted image Create color separation versions ( I ₁ '), ( II ₁ '), ( III ₁ ') with gradations inverted to the color separation versions ( I ₁ '), ( II ₁ '), ( III ₁ ' ) and is masked by the black component of the character D in FIG. _{5 (d) (IV 1)} , the color separation as shown in FIG. 5 (f) (I ₁ ") _{with, (II 1"), (} III 1 ") to create a, said color separations _{(I 1"), (II} 1 "), (III 1"), R, G, B is applied to the printing plate surface (not shown) for each ink that emits light. Then fit 5 color separations of the letter D is a black component created in (b) (IV ₁₎ a printing plate surface for UV absorption type ink (not shown), the R, G, and B Offset printing is performed using each light emitting ink and ultraviolet absorbing ink. At this time, the ultraviolet absorbing ink is printed at the end to emphasize the black portion and sharpen the image.
[0019]
As described above, the original having gradations has been described. However, in the present invention, an image having full-color gradation can be obtained by performing the same operation even in the case of an original having no gradation.
[0020]
【The invention's effect】
According to the present invention, unlike conventional color printing by subtractive color mixing, the principle of additive color mixing is used, and colorless fluorescent ink that emits light by irradiation with ultraviolet rays has a single color, full-color gradation instead of printing in opposite length. Can be printed with the same image. In addition, the printed matter obtained by the present invention cannot be normally recognized and cannot be duplicated by a general production method, and therefore has excellent anti-counterfeiting properties.
[Brief description of the drawings]
FIG. 1 is a diagram showing ideal spectral characteristics of additive color mixing.
FIG. 2 is a diagram showing ideal spectral characteristics of subtractive color mixing.
FIG. 3 is a diagram showing spectral characteristics of actual ink.
FIG. 4 is a principle schematic diagram of under color removal.
FIG. 5 is a diagram showing an example of color separation according to the present invention.
[Explanation of symbols]
1 Cyan (C)
2 Magenta (M)
3 Yellow (Y)
4 Black (BK)
5 White (base material)
IC component
II M component
III Y component
I 'I C component gradation inversion
II 'II M component gradation inversion
III '
Inversion of the Y component of III
Mask the C component of I ₁ "I 'with the BK component of IV ₁
II ₁ "
Mask the II 'M component with the IV ₁ BK component
Mask the Y component of III ₁ "III 'with the BK component of IV ₁ P Original x Specified optical density

Claims (4)

Using a primary color fluorescent ink that emits light in red, green, and blue, which cannot be recognized under normal light, and forms a full-color image by irradiating with ultraviolet light . Capture as an image with the B component, convert the captured R, G, B component image to cyan and black as the cyan component, convert to magenta and black as the magenta component, convert to yellow and black as the yellow component, Each of the converted images is subjected to gradation inversion, and each color separation version is created. The character or design is again captured as an image with R, G, B components by a scanner , and the captured image is converted into a cyan component and a magenta component. The yellow component and the black component are decomposed respectively. Fitted to the printing plate surface of use, the red, green-based, and printed with each ink emitting respectively blue, multicolor printed matter, characterized in that the scraper then ultraviolet absorbing ink. Using a primary color fluorescent ink that emits light in red, green, and blue, which cannot be recognized under normal light, and forms a full-color image by irradiating with ultraviolet light . Capture as an image with the B component, convert the captured R, G, B component image to cyan and black as the cyan component, convert to magenta and black as the magenta component, convert to yellow and black as the yellow component, Each of the converted images is subjected to gradation inversion, and each color separation version is created. The character or design is again captured as an image with R, G, B components by a scanner , and the captured image is converted into a cyan component and a magenta component. The yellow component and the black component are decomposed respectively. Fitted to the printing plate surface of use, the red, green-based, and printed with each ink emitting respectively blue, multicolor prints printing method being characterized in that subsequently scraper ultraviolet absorbing ink. Using a primary color fluorescent ink that emits light in red, green, and blue, which cannot be recognized under normal light, and forms a full-color image by irradiating with ultraviolet light. The image is captured as a B component, the captured image is converted into a cyan component, a magenta component, a yellow component, and a black component, and a color separation plate is created by reversing the gradation of the converted image, and the cyan component, the magenta component, The color separation version obtained by reversing the gradation from the converted image of the yellow component is masked with the black component to create a color separation version composed of cyan and black as the cyan component, and composed of magenta and black as the magenta component . create a color separation, to create a composed of yellow and black as the yellow component color separations, the cyan component, Ma Printer components, red with the respective color separation created from yellow component, green light, to create a printing plate surface for each ink that emits blue, the black UV absorption type ink color separations of components A multi-color printed matter that is applied to the printing plate surface and printed with each of the red, green, and blue light-emitting inks and ultraviolet absorbing ink. Using a primary color fluorescent ink that emits light in red, green, and blue, which cannot be recognized under normal light, and forms a full-color image by irradiating with ultraviolet light. The image is captured as a B component, the captured image is converted into a cyan component, a magenta component, a yellow component, and a black component, and a color separation plate is created by reversing the gradation of the converted image, and the cyan component, the magenta component, The color separation version obtained by reversing the gradation from the converted image of the yellow component is masked with the black component to create a color separation version composed of cyan and black as the cyan component, and composed of magenta and black as the magenta component . create a color separation, to create a composed of yellow and black as the yellow component color separations, the cyan component, Ma Printer components, red with the respective color separation created from yellow component, green light, to create a printing plate surface for each ink that emits blue, the black UV absorption type ink color separations of components A printing method for a multicolor printed matter, wherein the printing method is applied to the printing plate surface and printed with each of the red, green and blue inks and ultraviolet absorbing ink.

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