JPH06239078A - Image formation body with countermeasure applied to prevent forgery in copying - Google Patents

Abstract

PURPOSE:To provide an image formation body to which a countermeasure is applied to prevent forgery in copying, wherein disclosure property of blind patterns and invisible property of each pattern with the naked eye for various types of black-and-white copying machines and color copying machines are improved. CONSTITUTION:In a pattern wherein a large number of circular figures 10 having similar or different sizes are randomly scattered in such a manner that adjacent figures do not contact each other, either one of a blind pattern 11 of character, mark, etc., or a background pattern 12 is formed of halftone dots as a constituent unit of the circular figures, whereby an image formation body to which a countermeasure for preventing forgery in copying is applied is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a measure for preventing counterfeiting of securities such as stock certificates, corporate bonds, checks and cash cards by copying using various types of copying machines including monochrome or color. The present invention relates to a formed image forming body.

[0002]

2. Description of the Related Art Conventionally, as a technique for preventing the reproduction of printed matter by copying, a hidden pattern such as characters and marks utilizing the resolving power of a copying machine and a background pattern serving as the background are distinguished by the large and small halftone dots. Moreover, there are known prints printed in the same light color, and prints provided with a counterfeit prevention measure by copying with a tint block or a pattern layer on the entire print so that the distinction between the prints of each pattern cannot be visually recognized. To give an example, a "fake thing" consisting of 30% fine halftone dots with a screen ruling of 150 on the surface of a substrate such as synthetic paper.
A latent image consisting of letters such as is printed, and in the surrounding background,
The screen is a rough halftone dot with 85 lines, printed so that the latent image and the background can be seen uniformly by the naked eye. When this is copied with a copying machine, the rough halftone dot is reproduced as it is.
A latent image composed of fine halftone dots becomes faint or not reproduced at the time of reproduction, and a printed matter in which a latent image is copied with a contrast so that the latent image can be visually recognized is disclosed in JP-A-54-741.
It is known from Japanese Patent No. 25.

[0003]

However, the above-mentioned technique still has the following problems. That is,
The above-mentioned printed matter with a latent image suitable for preventing forgery responds moderately to black-and-white mode copying machines, but the reproducibility of color and resolving power has been improved for color copying machines which have rapidly spread in recent years. Therefore, the effect is reduced and it is difficult to judge. Further, since the latent image and the background pattern are adjacent to each other, it is easy to visually recognize the boundary between each pattern and the existence of the latent image can be visually recognized. Further, there are restrictions on the design, and there are cases in which different patterns of the tint block and the picture layer are printed to prevent visual recognition, but there is a problem that the degree of freedom in designing the printed matter is impaired.

Therefore, the present invention provides an image forming body in which the visibility of hidden patterns and the invisibility of each pattern with the naked eye are improved for various types of monochrome and color copying machines.

[0005]

In order to solve the above-mentioned problems, in an image forming body having a forgery prevention measure by copying, many circular figures having the same size or different sizes are in contact with the adjacent figures. In a pattern randomly scattered so that it does not occur, hidden patterns such as letters and marks and their background patterns are formed on the support with color materials of the same color and the same density, using each of the circular figures as a constituent unit. It is characterized in that a circular figure of either the hidden pattern or the background pattern is formed by halftone dots.

Further, the image forming body subjected to the forgery prevention measure by copying forms a hidden pattern such as characters and marks and its background pattern by using each of the circular figures as a constituent unit by a halftone dot, and the both patterns are formed. Are formed on the support with the same color and the same density on the support, and either the hidden pattern or the background pattern is larger or smaller than the other halftone dot, and the same halftone dot is overlapped at an angle that does not cause moire. It is characterized by being applied.

Further, according to the first and second aspects of the present invention, the image forming body which has been subjected to the forgery prevention measure by copying has one of the hidden pattern and the background pattern, and the relative visual sensitivity of the naked eye is low. It is formed by using a coloring material having a high reflectance on a shorter wavelength side than 450 nm and / or a longer wavelength side than 650 nm, and the other pattern is a normal printing of the same color and the same density as the coloring material forming the one pattern. It is characterized in that each pattern is formed with ink on the support and each pattern is not individually recognized by the naked eye.

Further, according to the first, second or third aspect, the figure which is a constitutional unit of the image forming body for which the forgery prevention by copying is applied is surrounded by a free curve (closed curve) in addition to the circular shape. It is characterized in that it is formed by a polygonal figure including characters and the like.

[0009]

In the image forming body of the present invention, the hidden pattern and the background pattern are printed with the ink having the same hue, and are randomly scattered and have the same or different circular shapes. Moreover, since either one or both of the hidden pattern and the background pattern are formed as a support with halftone dots, the existence of the hidden pattern cannot be visually recognized. Further, since it is printed with a light color material, it does not interfere with the visibility or design of the main image such as characters printed on or printed on, printing lines, images and the like.

<Operation on Monochrome Copy> Whether either the hidden pattern or the background pattern is formed by halftone dots, the hidden pattern is formed by large halftone dots, and the background pattern is formed by small halftone dots, and the hidden pattern By duplicating the halftone dots, the difference in resolving power of the copying machine and the pattern of carbon toner are reproduced densely, and there is a difference in contrast between the background pattern and the hidden pattern, and the hidden pattern is clearly visible and visible. It

<Operation on electrophotographic color copying machine or silver salt type color copying machine having high color reproducibility (reproducibility faithful to spectral reflectance curve) and high resolution> In the image forming body of the present invention, the background The spectral reflectance curve of the color material that has a high reflectance on the shorter wavelength side than 450 nm and / or on the longer wavelength side than 650 nm, which has a low relative visual sensitivity to the naked eye, is shown in Fig. 4 (A). As shown in FIG. 4A, the spectral reflection curve of the dye of the normal printing ink of the same color (green) and the same density as the color material used for the hidden pattern is shown in FIG. 4 (A).
It becomes (b). Here, the relative luminosity curve of the naked eye is as shown in FIG. 4 (B), and the wavelength of 500 to 650 nm feels stronger than the other wavelengths. Therefore, the spectral reflectance curves of the background pattern and the hidden pattern are indicated by 650 to 700 nm. The image forming body of the present invention is perceived by the naked eye as the same green color, because the difference in the reflectance caused is not felt. However, in electrophotographic color copiers and silver salt type color copiers with high color reproducibility, the region (650-700 nm) of the curve (a) showing high reflectance is reproduced as red, so the background pattern The green color is reproduced as a yellowish brown color, and the hidden pattern is reproduced as it is as a green color, and the copy has a difference in color contrast, and the hidden pattern appears and can be visually recognized with the naked eye.

<Operation on an electrophotographic color copying machine in which regions near 400 to 450 nm and around 650 nm to 700 nm are cut by a filter or the like so that the color reproducibility with respect to the original is faithful to the naked eye> General color copying machine 4 for yellow, magenta, cyan, and black
Although color toners and ribbons are used, the density of yellow is low, and therefore, when reproducing a standard color rather than other colors, the amount of yellow is larger than that of other colors. For this reason, the standard colors have been set, or the light-colored colors that have a large amount of yellow in copying machines with low resolution have extremely low usage of toner for cyan and magenta colors. Minutes are used normally and are reproduced in yellow, and those composed of small halftone dots are reproduced in yellow or disappear. Therefore, for example, when the image forming body of the present invention printed in a light green color is copied, the background pattern composed of small dots becomes yellow or disappears, and the pattern composed of large dots becomes green. Since it is reproduced or disappeared without being reproduced, the contrast of the color is added and the hidden pattern is visually recognized, or the desired design is lost, so that it is identified as a copy.

[0013]

Embodiment An embodiment will be described with reference to the drawings. FIG. 1 is an enlarged explanatory view of a hidden pattern (A) and a background pattern (B) formed of circular figures having different sizes according to an embodiment of the present invention. FIG. 2 is a circular figure of different size showing a constitutional unit in which one is solid printed and the other is formed by halftone dots.
FIG. 3 is an explanatory view showing (A), a hidden pattern and a background pattern (B) formed on the support by the above-mentioned constitutional units. See also FIG.
Is an explanatory view (A) in which circular-shaped figures of different sizes in other examples are used as a structural unit of halftone dots, and a hidden pattern and a background pattern (B) formed on a support by the structural unit.
FIG.

The image forming body provided with the anti-counterfeiting measure by copying according to the present invention is paper, synthetic resin paper, vinyl chloride sheet, PE.
A circular figure randomly drawn on the support (15) such as T
Make (10) and hide this figure as a pixel (11)
(For example, copy, copy, fake or other characters or marks are preferable). If this hidden pattern is positive, there is a negative relationship, and as a background excluding the hidden pattern, the background pattern is the circular figure (10) as above.
Make (12). This circular figure can also use figures of the same size, but it is preferable to randomly scatter figures of different sizes, and to avoid many of the figures from touching adjacent figures. (See Fig. 1). Further, as shown in FIG. 2, one of the constituent units of the figure is formed by solid (T) and the other is formed by halftone dot (S). For example, the hidden pattern (11) or the background pattern
65 lines to the pattern taken out of either one of (12)
Shading is performed using a screen of 15 to 40% (area ratio) with 150 lines to form a pattern structure formed with halftone dots (S), and both patterns are combined and printed with matching hue and color density. . At the time of this printing, it is preferable to use an ink toned in a light hue for both patterns. In the embodiment described above, the unit of one figure is solid (T), but is not limited to this, a line, a broken line,
Alternatively, a combination of a halftone dot and a line is also possible, and can be selected appropriately.

Further, as shown in FIG. 3, large and small circular figures having the same or different sizes as described above are displayed as halftone dots (S).
For example, the hidden pattern (11) is formed with a screen ruling of 65 lines and 20% halftone dot (S), and the background pattern (12) is formed with a screen ruling of 150 line and 20% halftone dot (S). S)
And a halftone dot pattern of 65% 20% halftone dots, which is formed by overlapping and printing 65% 20% halftone dots by changing the screen angle (to prevent the occurrence of moire). The image forming body is composed of (10). The formation of halftone dots at this time is 15% to 40 when the screen has 65 to 150 lines.
It is preferable to combine in the range of%. This is
If you form a hidden pattern and a background pattern with only large and small halftone dots, you can see the divided boundaries of both patterns,
It becomes unclear by changing the screen angle and overlapping.

In the above printing, a printing ink toned in a light hue was used, but either the hidden pattern (11) or the background pattern (12) had a low visibility of 450 nm to the naked eye. Shorter wavelength side and / or 650 nm
Coloring material with higher reflectance at longer wavelengths is printed on the support by toning it to green using cobalt blue, and other patterns are the same as the coloring material toninged above green with ordinary printing ink. By printing with matching hue and density, it is possible to support various types of color copying machines.

The hidden pattern (11) and the background pattern (1
The figure (10) that composes 2) is not limited to a circular shape, and may be formed by a polygonal figure (not shown) surrounded by a free curve (closed curve) such as letters and stars. Can be appropriately selected.

[0018]

According to the image forming body of the present invention, which is provided with the anti-counterfeiting measure by copying, since the boundary between the hidden pattern and the background pattern printing before copying is not known, it is difficult to visually recognize the existence of the hidden pattern, and the hidden pattern is hidden. Even if the main image such as other characters or patterns is given on the pattern or background pattern,
Since both patterns are formed in a light color, the main image is not difficult to see, and when copying, there is an effect that a hidden pattern that proves that it is a copy is revealed with clear contrast, and various printed materials Can be used as a tint block as a background. Further, the image forming body provided with the anti-counterfeiting measure by copying of the present invention produces various excellent effects such as being applicable to various types of monochrome and color copying machines.

[Brief description of drawings]

FIG. 1 is a hidden pattern (A) composed of circular figures having different sizes and a background pattern according to an embodiment of the present invention.
It is an explanatory view showing an enlarged example of (B).

FIG. 2 is a diagram illustrating a constitutional unit in which one is solid and the other is a halftone dot in one embodiment of the present invention, and a circular figure (A) of different size and the constitutional unit are formed on a support. It is explanatory drawing which shows the hidden pattern and background pattern (B).

FIG. 3 is an explanatory view (A) in which circular figures having different sizes are used as a structural unit of a halftone dot in another embodiment of the present invention, and a hidden pattern and a background pattern formed on the support by the structural unit. It is explanatory drawing which shows (B).

FIG. 4 is an explanatory diagram showing a spectral reflectance curve (A) and a relative luminous efficiency curve (B) of the naked eye according to the present invention.

[Explanation of symbols]

 10 ... Circular figure composed of different sizes 11 ... Hidden pattern 12 ... Background pattern 15 ... Support S ... Halftone dot T ... Solid printing

Claims (4)

[Claims] 1. In a pattern in which many circular figures having the same size or different sizes are randomly scattered so as not to contact adjacent figures, each of the circular figures is used as a constituent unit. Hidden patterns such as letters and marks and their background patterns are formed on the support with the same color and the same concentration of color material,
An image forming body provided with anti-counterfeiting measures by copying, characterized in that either the hidden pattern or the background pattern is formed by halftone dots. 2. In a pattern in which many circular figures having the same size or different sizes are randomly scattered so as not to contact adjacent figures, each of the circular figures is composed of halftone dots. Hidden patterns such as characters and marks and their background patterns are formed as a unit, and both patterns are formed on a support with a color material having the same color and the same density, and either the hidden pattern or the background pattern is the other. An image forming body provided with a forgery prevention measure by copying, which is larger or smaller than the halftone dot and overlaps the same halftone dot at an angle at which moire does not occur. 3. One of the hidden pattern and the background pattern is selected as a pattern having a low visual acuity of 450 n for naked eyes.
It is formed by using a coloring material having a high reflectance on the shorter wavelength side than m and / or the longer wavelength side than 650 nm, and the other pattern is a coloring material having the same color and the same density as the coloring material forming the one pattern. The image forming body, which is formed on a support and is so designed that each pattern is not individually recognized by the naked eye, and which has been subjected to counterfeit prevention measures by copying according to claim 1 or 2. 4. The figure, which is the structural unit, is formed by a polygonal figure surrounded by a free curve (closed curve), according to claim 1, claim 2 or claim 3. An image forming body that has been subjected to the forgery prevention measure by copying as described.