JP2006264292A - Printing base material for inhibiting forgery by copying - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing base material for inhibiting forgery by copying, for which the identification of a latent image by bare eyes is made more difficult before copying, and the latent image becomes easier to be discriminated after the copying. <P>SOLUTION: This printing base material 1 for inhibiting the forgery by copying has a latent image pattern 2 comprising half tone dots being printed on the surface of the base material, and a background pattern 3 comprising half tone dots being printed around the latent image pattern. In the printing base material 1, for the half tone dots constituting the background pattern 3, a total number of screen lines is set to be within a range of 150 lines to 175 lines, and for the half tone dots constituting the latent image pattern 2, a total number of the screen lines is set to be within a range of 65 lines to 85 lines. Also, the density of the latent image pattern 2 is set to be within a range of 12% to 14%, and the density of the latent image pattern 2 is set to be higher than the density of the background pattern 3, and also, a difference in the density is set to be within 2%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a printing substrate for preventing counterfeiting by copying.

For preventing forgery caused by copying important documents, for example, a latent image that is difficult to see with the naked eye is applied to the surface of paper, etc., while the latent image appears when copied. There is. It is a printed matter containing a latent image in which a latent image made of fine constituent molecules and a background made of fine constituent molecules coarser or denser than the latent image are printed on the surface of the printing substrate. For example, in the case where the latent image and the background fine constituent molecules are composed of halftone dots (dots), only the halftone dots printed as the latent image appear in a distinguishable manner, thereby preventing counterfeiting by copying. In this case, in comparison between the latent image and the background, it is difficult to identify the latent image before copying as much as possible. On the other hand, it is necessary to clearly distinguish the latent image that appears after copying. Therefore, in accordance with the former request that it is difficult to distinguish between the latent image before copying and the background, printing is generally performed so that both halftone dots have the same density. It is theoretically correct to set the latent image and the background dot to the same density. However, when printing is performed with the latent image and the background halftone dot set to the same density, the latent image is actually printed slightly lighter, that is, it may appear slightly white to the naked eye. The reason why such a difference occurs even though the same density is set is thought to be due to the difference in the number of lines of the halftone dots in the latent image and the background and the difficulty in fine adjustment on printing, The exact location is unknown. Under such circumstances, the present inventor has examined the relationship between the number of screen lines of the background pattern and the latent image pattern and the density difference thereof. Under certain conditions, the density of the latent image pattern is determined based on the background pattern. It has been found that when printing is set slightly higher than the density, the latent image is more difficult to see compared to the conventional (that is, printing with the same density), but the latent image is more clearly identified after copying. .
Patent Application Publication No. 45400 Patent Gazette

Conventional anti-counterfeit printing base materials print a latent image and a background composed of halftone dots using screens (two types) of the same density with different numbers of lines. In such a printing base material, This solves a problem in identifying a latent image, which is not always sufficient. That is, the present invention provides a printing base material for preventing counterfeiting by copying, which makes it more difficult to identify a latent image with the naked eye before copying, while making it easier to distinguish the latent image after copying.

In order to solve this problem, the anti-counterfeit printing substrate according to the present invention includes a latent image pattern composed of halftone dots printed on the surface of the substrate and a background composed of halftone dots printed around the latent image pattern. In a printing substrate for preventing forgery by copying having a pattern, the halftone dots constituting the background pattern have a screen line number of 150 to 175 lines, and the halftone dots constituting the latent image pattern have a screen line number of 65 to 85 lines. And the density of the latent image pattern is set within a range of 12% to 14%, the density of the latent image pattern is higher than the density of the background pattern, and the density difference is set within 2%. In particular, the halftone dots constituting the background pattern have 150 screen lines, the halftone dots constituting the latent image pattern have 85 screen lines, the latent image pattern density is 12%, and the latent image pattern density. Was set to 14%.

When the latent image pattern and the background pattern were compared, good results were obtained before and after copying for the discrimination or discrimination of the latent image pattern. In other words, the latent image pattern of the printed material (that is, before copying) is more difficult to see with the naked eye, while the latent image can be more clearly discriminated after copying. An anti-counterfeit paper was obtained by simple copying.

The best mode for carrying out the present invention will be described. On a printing substrate 1 such as printing paper, a latent image pattern 2 such as a character or a pattern such as “COPY” is printed with fine halftone dots, and the background pattern 3 is similarly finely dotted around the periphery. Printed. The latent image pattern 2 and the background pattern 3 are composed of halftone dots of different sizes, and the difference in halftone dot size becomes a difference in density by copying. That is, the background pattern 3 is not reproduced after copying, while the presence of a latent image such as “COPY” characters in the latent image pattern 2 is visibly reproduced, so that a real product and a fake copy can be distinguished.

The relationship between the number of screen lines and the screen density of the latent image pattern 2 and the background pattern 3 shows how the distinguishability and discriminability by the naked eye of the latent image pattern 2 in the printing equipment 1 such as printing paper changes before and after copying. In detail. As a result, when the screen density of the latent image pattern 2 is smaller than the screen density of the background pattern 3, the characters of the latent image pattern appear white to the naked eye before copying, while the characters of the latent image pattern 2 are slightly thinner after copying. , Lack of clarity. That is, it was confirmed that there was a problem with the distinguishability of the latent image pattern 2 before and after copying, and it was inappropriate. Moreover, when this was seen in relation to the original film used for printing the latent image pattern and the background pattern, when the original film was viewed with the naked eye, the characters that were the latent image pattern of the original film looked white.

On the other hand, if the screen density of the latent image pattern is larger than the screen density of the background pattern, the characters of the latent image pattern 2 appear clearly black with the naked eye before copying and the characters of the latent image pattern 2 after copying. Was clearly visible. Although it is preferable that the characters of the latent image pattern 2 are clear after copying, the characters of the latent image pattern 2 appear black with the naked eye before copying. It was confirmed that. Moreover, when this was seen in relation to the original film used for printing the latent image pattern and the background pattern, characters of the latent image pattern looked slightly black when the original film was visually observed.

In the above cases, there is a problem with the distinguishability of the latent image pattern 2. However, under certain conditions, if the density of the latent image pattern 2 is set slightly higher (that is, darker) than the density of the background pattern 3, the density of the latent image pattern and the density of the background pattern are set to be the same. It was found that the characters of the latent image pattern 2 were difficult to identify with the naked eye before copying, while the characters of the latent image pattern 2 could be clearly distinguished after copying. Here, the fixed condition is that the halftone dots constituting the background pattern are within the range of 150 to 175 screen lines and the halftone dots constituting the latent image pattern are within the range of 65 to 85 screen lines. Is set within a range of 12% to 14%, the density of the latent image pattern is set higher than the density of the background pattern, and the density difference is set within 2%.

The following Tables 1 and 2 show that in the background pattern 3 and the latent image pattern 2 having different numbers of lines, the latent image pattern 2 of the printing substrate 1 such as printing paper is copied before and after copying due to the change in density of the latent image pattern 2. It shows how it is identified and discriminated later with the naked eye. In this case, the discriminability and discriminability are relative judgments with the naked eye comparing the latent image pattern 2 and the background pattern 3. The screen line is the number of lines included per inch, and the screen density is the ratio of the halftone dot area per unit area.

A printing paper (A type according to the present invention) in which the density of the latent image pattern is set slightly higher (that is, darker) than the density of the background pattern, and a printing paper (B Refer to Table 1 for each type). First, the number of lines of the background pattern was 150, the number of lines of the latent image pattern was 85, and both the density of the background pattern and the latent image pattern were 10% (B type). In this case, the characters of the latent image pattern were clearly discriminated after copying, but the characters of the latent image pattern looked slightly white before copying, which was problematic. Looking at this in relation to the original film used for printing the latent image pattern and the background pattern, the characters of the latent image pattern looked slightly white on the original film before printing. On the other hand, the number of lines of the background pattern is 150, the number of lines of the latent image pattern is 85, the density of the background pattern is 10% m, and the density of the latent image pattern is 12% (A type according to the present invention). ). In this case, the characters in the latent image pattern were hardly identified before copying, but the characters in the latent image pattern were clearly discriminated after copying. When this was seen in relation to the original film used for printing the latent image pattern and the background pattern, the characters of the latent image pattern looked slightly black on the original film.

When the number of lines in the background pattern is 150, the number of lines in the latent image pattern is 85, and the density of the background pattern is 10%, the density of the latent image pattern is 8%, which is lower than the density of the background pattern. Further, when the ratio was 14%, which was higher than the A type, in any case, there was a problem in the distinguishability and discriminability of the latent image pattern before and after copying, which was inappropriate (see Table 1).

Next, the number of lines in the background pattern was 150, the number of lines in the latent image pattern was 85, and the density of both the background pattern and the latent image pattern was 12% (B type). In this case, the characters of the latent image pattern were clearly discriminated after copying, but there was a problem that the characters of the latent image pattern looked slightly white before copying. Looking at this in relation to the original film used for printing the latent image pattern and the background pattern, the characters of the latent image pattern looked slightly white on the original film before printing. On the other hand, the number of lines of the background pattern was 150, the number of lines of the latent image pattern was 85, the density of the background pattern was 12% m, and the density of the latent image pattern was 14% (A type according to the present invention). In this case, the characters in the latent image pattern were hardly identified before copying, but the characters in the latent image pattern were clearly discriminated after copying. When this was seen in relation to the original film used for printing the latent image pattern and the background pattern, the characters of the latent image pattern looked slightly black on the original film before printing.

When the number of lines of the background pattern is 150, the number of lines of the latent image pattern is 85, and the density of the background pattern is 12%, the density of the latent image pattern is 10%, which is lower than that of the B type, At 8%, in both cases, there was a problem in the distinguishability and discriminability of the latent image pattern before and after copying, which was inappropriate (see Table 1).

Next, referring to Table 2, the printing paper (A type according to the present invention) and the printing paper (B type) will be compared. First, the number of lines of the background pattern was 175, the number of lines of the latent image pattern was 65, and both the density of the background pattern and the density of the latent image pattern were 10% (B type). In this case, the characters of the latent image pattern were clearly discriminated after copying, but the characters of the latent image pattern looked slightly white before copying, which was problematic. When this was taken as a reference for the original film used for printing the latent image pattern and the background pattern, the characters of the latent image pattern looked slightly white on the original film.
On the other hand, the number of lines of the background pattern was 175, the number of lines of the latent image pattern was 65, the density of the background pattern was 10% m, and the density of the latent image pattern was 12% (A type according to the present invention). In this case, the characters in the latent image pattern were hardly identified before copying, but the characters in the latent image pattern were clearly discriminated after copying. When this was seen in relation to the original film used for printing the latent image pattern and the background pattern, the characters of the latent image pattern looked slightly black on the original film before printing.

When the number of lines of the background pattern is 175, the number of lines of the latent image pattern is 65, and the density of the background pattern is 10%, the density of the latent image pattern is 8%, which is lower than that of the B type. In addition, when 14%, which is higher than that in the case of the A type, there was a problem in the distinguishability and discriminability of the latent image pattern before and after copying, which was inappropriate (see Table 2). ).

Next, the number of lines in the background pattern was 175, the number of lines in the latent image pattern was 65, and the density of both the background pattern and the latent image pattern was 12% (B type). In this case, the characters of the latent image pattern were clearly discriminated after copying, but the characters of the latent image pattern looked slightly white before copying, which was problematic. When this was seen in relation to the original film used for printing the latent image pattern and the background pattern, the characters of the latent image pattern looked slightly white on the original film. On the other hand, the number of lines in the background pattern was 175, the number of lines in the latent image pattern was 65, the density of the background pattern was 12% m, and the density of the latent image pattern was 14% (A type according to the present invention). In this case, the characters in the latent image pattern were hardly identified before copying, but the characters in the latent image pattern were clearly discriminated after copying. When this was seen in relation to the original film used for printing the latent image pattern and the background pattern, the characters of the latent image pattern looked slightly black on the original film before printing.

When the number of lines of the background pattern 3 is 175, the number of lines of the latent image pattern 2 is 65, and the density of the background pattern 3 is 12%, the density of the latent image pattern 3 is more than that of the B type. When the values were 10% and 8%, which were low, in both cases, there was a problem in the distinguishability and discriminability of the latent image pattern 3 before and after copying (printed material) and after copying (see Table 2).

As described above, regarding the A type according to the present invention, good results were obtained with respect to the discrimination and discrimination of the latent image pattern before and after copying. As a result of such investigation, the halftone dots constituting the latent image pattern have the screen line number of 65 to 85 lines, the screen density within the range of 10% to 14%, and the halftone dots constituting the background pattern. The number of screen lines is 150 to 175, the screen density is in the range of 8% to 12%, the density of the latent image pattern is higher than the density of the background pattern, and the density difference is set to 2% or less. The latent image pattern was well identified and discriminated before and after copying. It is particularly preferable that the halftone dots constituting the background pattern have a screen line number of 150 lines, the halftone dots constituting the latent image pattern have a screen line number of 85 lines, the latent image pattern density is 12%, The density is set to 14%.

In relation to the original film on which the latent image pattern 2 and the background pattern 3 are printed, when the density of the latent image pattern and the background pattern is the same, the latent image pattern of the original film looks a little white, The characters of the latent image pattern on the printing substrate also looked slightly white. However, if the density of the latent image pattern is further increased beyond this, the characters of the latent image pattern on the original film appear slightly black. This stage at which the latent image pattern of the original film looks slightly black is basically consistent with the case where the density of the latent image pattern is slightly higher than the density of the background turn and the density difference is set within 2%. Was confirmed. In other words, on such a printing substrate made of an original film, the characters of the latent image pattern are hardly identified before copying, while the characters of the latent image pattern are clearly distinguished after copying, and the latent image pattern is identified before and after copying. And discrimination were good. Accordingly, the printing base material 1 with good discrimination and discrimination of the latent image pattern can be determined based on the fact that the latent image pattern on the corresponding original film looks slightly black.

FIG. 3 is an explanatory plan view of a printing paper before copying, which is a printing substrate according to the present invention. FIG. 3 is an explanatory plan view of a printing paper after copying which is the same printing substrate.

Explanation of symbols

1 Printing substrate such as printing paper 2 Latent image pattern 3 Background pattern

Claims (2)

A mesh constituting a background pattern in a printing base material for preventing forgery by copying having a latent image pattern consisting of halftone dots printed on the surface of the base material and a background pattern consisting of halftone dots printed around the latent image pattern The dots are the screen lines of 150 to 175 lines, the halftone dots constituting the latent image pattern are the screen lines of 65 to 85 lines, and the latent image pattern density is within the range of 12% to 14%. A printing base material for preventing counterfeiting by copying, wherein the density of the latent image pattern is higher than the density of the background pattern and the density difference is set within 2%. A mesh constituting a background pattern in a printing base material for preventing forgery by copying having a latent image pattern consisting of halftone dots printed on the surface of the base material and a background pattern consisting of halftone dots printed around the latent image pattern The number of dots is 150, the number of halftone dots constituting the latent image pattern is 85, and the density of the latent image pattern is set to 12% and the density of the latent image pattern is set to 14%. Printing base material for preventing counterfeiting by copying.

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