JPH0764147B2 - Copy forgery protection paper - Google Patents

Description

TECHNICAL FIELD The present invention relates to a copy forgery-prevention paper which allows a color copying machine to erase an image printed on the surface thereof so as to let the user know that it is a copy. .

[Prior Art] As a conventional anti-counterfeiting technology, a latent character image such as "invalid" or "copy" that is invisible to the naked eye is printed on the surface, and when it is applied to a copying machine, the latent image appears and appears as a copy. A printed matter (see, for example, Japanese Patent Publication No. 58-47708) or a part of the image that is obvious is printed with halftone dots of mixed three primary colors, and if you make a copy, the color of the image changes and you can see that it is not genuine A printed matter (see, for example, Japanese Utility Model Laid-Open No. 59-99774) is known.

[Problems to be Solved by the Invention] Among them, the former conventional technique is a camouflage that prints a latent image with halftone dots having a size different from that of the background and hides the latent image over both the background and the latent image. A large pattern is provided, and when a latent image is not normally visible and copying is performed, large halftone dots are reproduced and small halftone dots are no longer reproduced.As a result, the latent image is visually recognized due to the difference in brightness and darkness. Since the latent images are interfered with each other, the latent images after copying are not discriminated as expected, so that the forgery preventing effect is not sufficient.

In addition, the latter technique only makes use of the color reproducibility of color copiers to produce different shades in the image after copying, so there is a risk of wondering if it is a fake person unless carefully observed. However, there is a problem that it cannot be a sufficient anti-counterfeiting measure.

INDUSTRIAL APPLICABILITY According to the present invention, a pattern pattern having a decorative effect and a background pattern having a color that is clearly distinguished from the pattern disappear when applied to a copying machine, so that it becomes clear that it is a copy. It is an object of the present invention to provide a copy forgery prevention paper suitable for a color copying machine.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has the following technical means, that is, the darkness of a remarkable size printed on the surface of the base paper 1. Color pattern 2 is 15
The background pattern 3 is composed of 0 to 175 lines and 10% halftone dots, and the background pattern 3 other than the above-mentioned pattern pattern 2 has a color that can be clearly discriminated from the pattern pattern and is 150 to 175 lines and 10% halftone dot like the pattern pattern. It is characterized in that it is solidly printed with a wording 4 which is composed of dots and thus shows that the pattern pattern 2 and the background pattern 3 are provided on a part of the surface of the base paper 1.

[Operation] The background pattern has a color that can be clearly distinguished from the pattern pattern, and since the overall shapes of the two are completely different, they are clearly visible.
Lines or 175 lines and 10% halftone dots are hardly reproduced even if the copy density is adjusted, so neither the pattern pattern nor the background pattern appears, and the copy paper has only the words with the pattern pattern and the background pattern. As it appears, it is immediately understood that it is not a genuine document.

[Embodiment] The present invention will be described below with reference to the drawings. In FIG.
Is composed of 10% halftone dots of 165 lines consisting of dark red, and the background pattern 3 other than the pattern pattern is composed of 10% halftone dots of 165 lines consisting of blue-green which has a complementary color relationship with red. . The background pattern 3 is composed of characters and symbols in addition to a tint block pattern as shown in the figure.

Furthermore, the bottom of the surface of the base paper 1 is solidly printed with the wording 4 stating that "This paper contains a red pattern and a blue-green tint pattern." A pattern pattern 2 is applied to the surface. It is shown that.

As described above, the pattern pattern 2 and the background pattern 3 are both
Although 165 lines are composed of 10% halftone dots, the pattern pattern is dark red, while the background pattern is blue-green, which has a complementary color relationship with this, so the contrast between the two becomes significant, and therefore pattern pattern 2 Is clearly recognized.

When the present invention thus constructed is applied to the latest color copying machine Xerox Color Copier 6800, 165 lines 1
The 0% halftone dot is not reproduced by the copying machine regardless of the shade of color, and neither the pattern pattern nor the background pattern appears on the copy paper 5, giving the impression that these have disappeared, and only the wording 4 is reproduced. Therefore, it was easily recognized that it was not an authentic document (see Fig. 3).

As a result of the experiment, if the size of the halftone dot is in the range of 150 lines to 175 lines / 10%, the resolution of the copying machine will not reach, and it was found that the pattern pattern and background pattern could not be reproduced, and normal (black and white copying) It cannot be reproduced by a copying machine), and even if a halftone dot with a larger dot size is used, even if a light color ink is used, both the pattern pattern and the background pattern are reproduced when applied to a copying machine, so the effect as copy forgery prevention paper is not expected.

[Effects of the Invention] The present invention has the following unique effects.

(1) Since the background pattern is clearly discriminated against the pattern pattern, the pattern pattern can be clearly recognized and the decorative effect can be fully exhibited.

(2) 150 to 175 lines ・ The pattern pattern and background pattern printed with 10% halftone dots are clearly visible,
Due to the poor resolution of the copier, halftone dots of the above size are not reproduced when copying, so no pattern pattern or background pattern appears on the copy paper, whereas the pattern pattern and the text indicating the background pattern are reproduced as they are. Therefore, it is easy to see that the paper is a copy,
Therefore, forgery can be prevented.

(3) Since the surface of the copied paper is white and plain, unlike the conventional method in which part of the background or image is reproduced,
The difference between the printed matter and the copied matter becomes clearer.

(4) While the pattern pattern and background pattern do not appear after copying, the sentences, numbers, etc. written on the surface of the paper are clearly reproduced along with the wording, so that these sentences and the like can be read easily.

(5) Both the pattern pattern and the background pattern have the same halftone dots, and since it is not necessary to provide a camouflage pattern or a troublesome linear pattern as in the conventional case, it does not take time to print. Since it is solidly printed, it can be provided with the same ink as the pattern pattern or background pattern, and the product can be obtained efficiently and inexpensively.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a schematic plan view, FIG. 2 is a partially enlarged view of the same as above, and FIG. 3 is a plan view of a state in which the paper of FIG. 1 is copied. 1 ... Base paper, 2 ... Pattern pattern, 3 ... Background pattern, 4 ... Text

Claims (1)

[Claims] 1. A background pattern 3 other than the above-mentioned pattern pattern 2 in which a dark-color pattern pattern 2 of a remarkable size printed on the surface of a base paper 1 is composed of 150 to 175 lines and 10% halftone dots.
Is a color that can be clearly distinguished from the pattern pattern and is composed of 150 to 175 lines and 10% halftone dots like the pattern pattern,
Thus, a copy forgery prevention sheet characterized in that a text 4 indicating that the pattern pattern 2 and the background pattern 3 are applied is solidly printed on a part of the surface of the base paper 1.