JPH0852931A - Copy forgery preventing paper having smooth surface - Google Patents

Abstract

PURPOSE:To provide forgery preventing paper characterized by that a latent image is not recognized by the naked eye even when a camouflage pattern or a decorative pattern is not provided, a surface is confirmed uniformly smoothly, the development of the latent image after copying is sharp and no moire is generated even when the lap-printing of cut decoration is applied. CONSTITUTION:One of the background 2 and latent image 3 applied to the surface of base paper 1 is constituted of fine spot patterns of the same size with a diameter of 80-130mum and density of 20-30% arranged at random and the other one of them is constituted of fine spot patterns of the same size with a diameter of about 60mum and density of 20-30% arranged at random.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copy-forgery-preventive paper having a smooth surface, which reveals a latent image when it is applied to a copying machine and informs that the paper is a copy.

[0002]

2. Description of the Related Art On the surface of a sheet of paper, a character latent image with "copy", "VOID", "fake", etc. is printed so that it cannot be distinguished from the background. Anti-counterfeit papers are known which warn that the paper is not genuine because it is reproduced and the other is not reproduced, and thus the latent image is visible (for example, Japanese Patent Publication 58-47).
708 and Japanese Patent Publication No. 1-5835).

The former of the prior arts, as shown in FIG. 6, prints a background 12 on the surface of a base paper 10 using halftone dots, and the white dots of the background 12 have halftone dots different in size from the background. Is used to print a latent image 13 labeled as "VOID" and to hide the latent image 13 by incorporating a camouflage pattern (not shown) that divides the background 12 and the latent image 13 into the whole. Yes, the latter technique, as shown in Figure 7,
One of the background 22 and the latent image 23 printed on the surface of the base paper 20 is printed with halftone dots, and the other is printed with lines, and the latent image 23 is printed.
A decorative pattern (not shown) is overprinted with a light-colored ink that cannot be reproduced by copying to hide the latent image.

[0004]

The former technique is, therefore,
The camouflage pattern is provided because the size difference between the halftone dots forming the background 12 and the latent image 13 is extremely large. However, when copying, the camouflage pattern finely divides both the background 12 and the latent image 13. Therefore, the appearance of the latent image 13 is weak,
Therefore, it is troublesome for some printed matter because the anti-counterfeiting effect cannot be fully exerted and the camouflage pattern becomes a pattern in advance and is recognized on the paper surface.
It was not always appropriate for a wide range of documents.

In the latter technique, the background 22 and the latent image 23 are symmetrically constructed by halftone dots and lines, which are different shapes, and the lines are reproduced in dark colors when applied to a copying machine. Since halftone dots are not reproduced, it has the advantage that the appearance of the latent image after copying becomes clear, but since the means for overprinting the decorative pattern is taken, the printing cost is high and the pattern is unnecessary. There is a problem that it is not suitable for documents to be processed.

That is, in the above-mentioned conventional technique, the former uses the printing means of halftone dots and halftone dots, and the latter uses the halftone dots and lines, but the halftone dots and lines are unified at 45 degrees or 90 degrees. Due to the arrangement and the periodic regular intervals, especially when resolving large halftone dots and lines on a copying machine, the arrangement is visually recognized when observed carefully, and therefore the camouflage pattern or If you do not apply a light color pattern, the latent image is not hidden and the appearance as a printed matter is impaired,
Large halftone dots and lines create vacant points and line intervals, so
In particular, a large space is likely to occur at the boundary between the small halftone dot and the outer portion of the latent image after copying is unclear, which is inconvenient.
In the case of overprinting a cut decoration such as a halftone photograph, there is a common drawback that moire is likely to occur due to interference between the halftone dot and line arrangement direction and the cut printing.

The present invention has been made in view of the above-mentioned prior art, and the object of the present invention is to provide a background and a latent image.
Constituted by a fine dot pattern arranged at random, as well as even less visible a latent image without taking a means for overprinting a decorative pattern or incorporate cam off large pattern, in any printed material because the surface looks uniformly smooth Another object of the present invention is to provide an anti-counterfeit paper in which moire does not occur even when overlaid with cut decorations and the latent image after copying is clearly visible.

[0008]

In order to achieve the above object, the present invention takes the following means, that is, a background and a latent image are formed on the surface of a base paper and the background and the latent image are visible to the naked eye. Although it cannot be identified, one of the background and latent image is reproduced when the copy is made, and the other is not reproduced, so that the latent image can be visually confirmed. The fine dot patterns of the same size are randomly arranged, and the other fine dot patterns of the same size are randomly arranged that cannot be resolved by a copying machine. Thirteen
It is characterized in that the fine dot pattern which cannot be resolved has a diameter of approximately 60 μm and a density of 20% to 30%.

[0009]

[Function] A fine dot pattern that can be resolved by a copying machine and a fine dot pattern that cannot be resolved are randomly arranged, and there is no unity and it looks as if it is a fine grained grain, so the naked eye is dazzled. However, the latent image cannot be seen because the surface of the base paper is recognized as a smooth flat surface.

When the above paper is applied to a copying machine, the diameter is 80 μm.
A fine dot pattern having a value of ~ 130μ and a density of 20% to 30% is resolved and reproduced and becomes a dark color.
A fine dot pattern having a value of μ and a density of 20% to 30% is not resolved, so that it becomes a light color and the contrast between the two is remarkable and a latent image is recognized.

[0011]

EXAMPLE FIG. 1 shows a background 2 and a “COP” on the surface of a base paper 1.
This is a schematic view of the main sheet on which the latent image 3 labeled "Y" is printed. The background 2 and the latent image 3 have a completely integrated appearance, and the surface is seen as a uniform plane, so the latent image is not visible.

FIG. 2 is an enlarged view of FIG. 1, and it can be seen that the background 2 and the latent image 3 are composed of large and small fine dot patterns. The fine dot patterns of the same size, which constitute the background 2, have a diameter of 100 μ and a density of a little over 20%. The fine dot patterns are arranged at random to form the background 2. The fine dot patterns having the above numerical values can be resolved by a copying machine, and therefore the background 2 is reproduced by copying. The fine dot pattern has a diameter of 80.
The same object can be achieved within the range of μ to 130 μ and density of 20% to 30%.

Fine dot patterns of the same size which form the latent image 3 for a character displayed as "COPY" have a diameter of 60 μ and a density of 2.
It is a little over 0% and becomes a latent image 3 by randomly arranging it like the background. Since the fine dot pattern is not restricted by the arrangement unlike the conventional case, it can be applied to the outer contour of the character forming the latent image. In this case as well, the fine dot pattern includes a numerical value of around 60 μm, and the same purpose can be achieved as long as it is within the range of the density of 20% to 30%.

FIG. 3 shows a state in which the above-mentioned paper is applied to a copying machine. The background 2 is reproduced and appears dark on the copy paper 1a, and the latent image 3 is not reproduced and becomes a ground color.
That is, when the image is applied to a color copier, the background 2 is reproduced in a deep color, but the latent image 3 is not reproduced and becomes a light color. When applied to a black-and-white copier, the background 2 appears black, whereas the latent image 3 is reproduced. It is outlined and both are background 2 and latent image 3.
The latent image 3 is clearly recognized because the contrast of is clear.

In contrast to the above-mentioned embodiment, FIG. 4 shows the background 2 composed of a fine dot pattern of 60 μ · 20% and the latent image 3 of 100 μ / 20% on the surface of the base paper 1. The fact that they are arranged at random is the same as in the previous embodiment. Then, when this paper is applied to a copying machine, as shown in FIG. 5, the fine dot pattern of 60 μ / 20% is not reproduced, but the fine dot pattern of 100 μ / 20% is reproduced, so that the background 2 is a light color and the latent image 3 Appears in a dark color, the contrast between the two becomes remarkable, and the latent image 3 is clearly visible.

[0016]

The present invention as described above has the following unique effects. (1) Since the fine dot patterns constituting the background and the latent image are randomly arranged, the fine dot patterns in the background and the latent image interfere with each other, and when the surface of the base paper is observed, the dots or lines as in the conventional case are observed. It is not as a pattern of a specific shape, but as if it were visually recognized as a fine grained pattern, dazzling the naked eye, and the background and latent image are indistinguishable. Good for a wide range of prints. (2) Since the latent image is composed of the fine dot pattern so as to fill the outer portion, it clearly appears when copying, and the background fine dot pattern is also arranged without any space between the latent image and the latent image. Because it is possible, the contrast with the latent image after copying becomes clear. On the other hand, before copying, the fine dot patterns on both sides are in close contact with each other, so that they interfere with each other and are disturbed, making it impossible to distinguish between the background and the latent image. (3) In the case of overprinting cuts such as decorative paintings and photographs, the conventional arrangement of dots or lines in a regular arrangement may cause moire due to the influence of the arrangement direction, impairing the appearance. Since the fine dot patterns are randomly arranged, no moire is generated and no trouble occurs even when overprinting. (4) It is free to incorporate a camouflage pattern or overprint a decorative pattern with a light-colored ink as in the conventional case, and in that case, when copying, the latent image can be visually recognized more clearly than before.

[Brief description of drawings]

FIG. 1 is a schematic plan view of the sheet.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a plan view obtained by copying FIG.

FIG. 4 is a partially enlarged view of another embodiment.

FIG. 5 is a plan view of a copy of the sheet of FIG.

FIG. 6 is a plan view showing an example of a conventional technique.

FIG. 7 is a plan view showing another example of the conventional technique.

[Explanation of symbols]

 1 Base paper 2 Background 3 Latent image

Claims (1)

[Claims] 1. A background 2 and a latent image 3 are provided on the surface of a base paper 1,
Although the background 2 and the latent image 3 cannot be discriminated by the naked eye, one of the background 2 and the latent image 3 is reproduced when the copy is made, and the other is not reproduced, so that the latent image 3 is visually recognized. And one of the latent images 3 are composed of randomly arranged fine dot patterns of the same size which can be resolved by the copying machine, and the other is composed of randomly arranged fine dot patterns of the same size which cannot be resolved by the copying machine. The resolvable fine dot pattern has a diameter of 80 μ to 130 μ and a density of 20%.
30%, a non-resolvable fine dot pattern having a diameter of about 60 μ and a density of 20% to 30%, and a copy-forgery-proof paper with a smooth surface.