JP3230753B2 - Method for preventing production of counterfeit copy by digital copier and paper to be copied - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing the production of a counterfeit copy, which can prevent the production of a counterfeit product even when a digital copying machine having a high resolution is used, and a paper to be copied.

[0002]

2. Description of the Related Art Conventionally, in order to prevent a counterfeit copy of a check or the like from being produced using a copying machine, a certain change occurs on the copy paper side when copying a copy of a check or the like. Proposals have been made to clarify the difference between copied paper and copied paper.

[0003] For example, Japanese Patent Publication No.
One disclosed in Japanese Patent No. 47708 is known.

That is, in this image, one of the two types of tone images is formed so as to be reproducible by a color copying machine, and the other is formed as non-reproducible.
In addition, a cam-flage tone image that cannot be reproduced by a color copying machine is formed so as to cover these tone images.

For this reason, when observing with the naked eye, the two types of tone images cannot be distinguished, but when copied by a color copier, the other side of the two types of tone images is not reproduced, and one side is reproduced. It is clearly reproduced on a copy sheet as a warning document or the like, and the difference between the original copy sheet and the copy sheet is clarified, thereby preventing counterfeit products based on the copy sheet.

In addition, as described in Japanese Utility Model Laid-Open Publication No. Sho 59-112681, moire is generated in a printed material which is a preliminary manuscript, and when the printed material is copied, the copy paper is distorted due to lens aberration of a copier. In some cases, the moiré on the side changes differently from the moiré of the printed matter, and the difference in moiré makes it easier to find a counterfeit copy.

Further, as disclosed in Japanese Utility Model Laid-Open Publication No. 1-85760, a pair of wire groups intersect at an angle of 45 ° or less, and are overlapped so that the image information of a printed material to be read can be read. When moiré is performed, moirés are formed at the intersections, and the moirés cover the image information of the printed matter, so that the image information cannot be read at all.

[0008]

However, the above-mentioned Japanese Utility Model Publication No. 58-47708 discloses an n-line / in
Since a warning document or the like is formed as a hidden character based on the size of the halftone dot and the size of the pitch set in the line density of the channel, the printing of the hidden character is particularly difficult, and the entire copy density range ( It has the drawback that it is difficult to adapt to (dark → light → dark) and is easily seen.

Furthermore, in recent years, digital copiers have become very popular, and the resolution is higher than that of conventional analog copiers. Therefore, all image information is read exactly as it is and copied as the original document. A new problem has arisen that hidden characters as warning documents are not reproduced and copy counterfeiting cannot be prevented.

In the case of using a digital copier having an increased resolution, the technique disclosed in Japanese Utility Model Application Laid-Open No.
Also in the case of the publication No. 1, the copy having the same moiré as the moire generated in the original document is performed in advance, and the difference between the original document and the copy paper is not clear.

Further, even in the case of Japanese Utility Model Laid-Open No. 1-85760, the same copy as that of the original is performed, so that the image information to be hidden is reproduced as it is. Cause problems.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a purpose thereof is to generate moire on the copy paper side depending on the inclination angle of a dot or a group of lines with respect to a reading reference direction. Focusing on the performance of digital copiers, even if a high-resolution digital copier is used, the same copy as the copy paper is not performed, but the difference is made to appear on the copy paper to distinguish the difference from the copy paper. It is an object of the present invention to provide a method for preventing the production of a counterfeit copy by a digital copying machine, which can be clarified, and a paper to be copied.

[0013]

SUMMARY OF THE INVENTION The present invention, in order to achieve the above object, as in claim 1, wherein, digital
When the copy paper is read in the reading reference direction of
Line density of n-line / inch with an inclination angle that generates moiré on the copy paper or does not generate moiré
With indicia <br/> printing form the background portion of one of the dot or interlacing lines in the copy sheet, the first in the desired location in the background section
1 is the same linear density and dot or line group the first
The dot or line group with a tilt angle of so that to generate a moire if when Ru is generated moire so as not to generate moire and not to generate the moire
At least one hidden character portion consisting of two dots or a group of lines is formed by printing, and the hidden character portion is visually recognized in the same color as the background portion when viewed, but is not visible when copied by a digital copying machine. The moire generated on either side of the hidden character portion causes the hidden character portion to appear visually on the copy paper.

Further, according to a second aspect of the present invention, a digital copy
-An angle of inclination that causes moiré or no moiré on copy paper when read in the machine reading reference direction.
And the background portion printed formed by the first dot or line group linear density of the n lines / inch with a, a being a desired portion of the background portion, the first dot or line group moiré If the Ru is generated is so as not to generate a moire, also of generating moire when not generated moire
It characterized by having a a hidden text portion to be printed formed by the second dot or line group so that a tilt angle allowed.

[0015]

According to the present invention, when copying is performed by a digital copying machine, a hidden character portion printed so as not to be seen on the copy paper is moire generated in the hidden character portion or, conversely, moire generated in the background portion. The copy paper appears as a difference from the background part that can be visually recognized on the copy paper, so that the difference between the copy target paper and the copy paper can be clarified. Therefore, it is possible to prevent the manufacture of a copy counterfeit using the copy paper. be able to.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of the present invention. As shown in FIG. 1, a printed material 1 to be copied is printed with a dot g as an enlarged view of a portion A in FIG. The background part 2 is formed.

Further, as the desired location in the background section 2 shown enlarged in part B in the figure at least one of the hidden characters 3 by the printing of the dot g ₁ is formed.

That is, the dot g of the background portion 2 is shown in FIG.
As shown in FIG. 3A, a dot is composed of dots having a line density of n lines / inch, and is referred to as a reading reference direction of an original (x line direction in the figure).
A predetermined inclination angle with respect to 30 ° in this embodiment.
Is printed as

[0020] In contrast, tint g ₁ forming the hidden characters part 3, as shown in FIG. (B), but the same linear density and dot g further inclined at a prescribed angle with respect to an inclination angle In this embodiment, the printing is performed at an inclination angle of 15 °.

Next, the relationship between the background portion 2 and the hidden character portion 3, the inclination angle of the selected dot, and the like will be specifically described.

As shown in FIG. 5, a known analog copier 10 is configured such that reflected light applied to a printed material 1 serving as an original G is
Since the image information is copied as it is optically focused on the photoreceptor 10c through the optical system such as the lens 10a and the mirror 10b, so-called moire (interference fringes) does not occur on the copy paper. .

However, as shown in FIG. 6 (a), the digital copier 20 introduces the reflected light radiated on the printed matter 1 serving as the original G into the image pickup device 20a such as a CCD and performs photoelectric conversion, thereby performing the conversion of the image information. A binarization process is performed based on an analog signal corresponding to shading, and image information is copied based on the image signal.

Although the resolution of such a digital copier 20 is dramatically improved as compared with the conventional analog copier 10, as shown in FIG. It is known that interference occurs and moire occurs depending on how the pixels 30... And the dot of the original G overlap.

Table 1 shows the results of a test conducted by the applicant of the present invention on the occurrence of moire using a color copier "Pixel Dio (CLC-500)" manufactured by Canon.

[0026]

[Table 1]

As is clear from the table, for example, 85
Line, in the case of a dot with a line density of 30%, the inclination angle 30
As shown by "x", when copying is performed, moire does not occur on the copy paper when copying is performed, and the copy paper cannot be visually confirmed.

However, the inclination angle of 15 ° is “◎”, and moire is generated on the copy paper, and the copy paper can be clearly confirmed.

In addition, the inclination angles are 15 °, 20 ° and
Even at 70 ° , “◎” is the same as above, and at 75 ° , “○” is obtained, but the inclination angles are 0 °, 30 °, 60 °, and 90 °.
In the case of, it is "x". Therefore, the inclination angle background portion 2 of the printed matter 1 is 30 ° and Dot g, inclination angle hidden text portion 3 is a dot g ₁ of 15 °, for example, if print characters of "invalid", the usual At the time of visual observation, the difference between the background portion 2 and the hidden character portion 3 is not visually recognized as shown in FIG. 2A, but if this is copied by a digital copying machine, as shown in FIG. In 4, moiré occurs in the hidden character 3 and an “invalid” character appears.

FIG. 2A shows the result of setting and copying the printed matter 1 so as to be 0 ° with respect to the normal reading reference direction. In some cases, the printed matter 1 is set so as to be at 90 °. In this case, the tint point g of the background part 2 is at 60 ° with respect to the reading reference line, and the dot B of the hidden character part 3 is B _1. Is 75 °.

Therefore, as is apparent from Table 1, the background portion 2 where the tint point g is at 60 ° is “×” and the B portion is “○”. Moire does not occur, but moiré occurs in the hidden character portion 3, and “invalid” characters appear on the copy paper 4.

On the other hand, the moiré may not be generated on the side of the hidden character portion 3 as described above, and the inclination angle of each halftone dot may be selected so as to be generated on the side of the background portion 2. Instead of assuming 0 ° or 90 °, the angles of the background portion 2 and the hidden character portion 3 can be selected by assuming various angles. In addition, the background portion 2 and the hidden character portion 3 may be formed by printing using a group of other lines with halftone dots. As shown in FIG.
And other desired characters and figures.

[0033] Thus according to the present invention, the dot g ₁ or interlacing lines of hidden text 3 provided in Dot g or line group and in the background section 2 forming the background portion 2, the same line density Since it is formed as an isomorphous dot or line group,
Unlike the related art, it is not necessary to change the size and pitch of each dot or line group, and printing can be easily performed.

Further, the background portion 2 is formed by printing a moire dot g or a line group having an inclination angle which does not generate moire or a moire with respect to the reading reference direction, and also has a moire dot g or moire which forms the background portion 2. If the group of lines to generate moire so as not to generate moiré, also at least one hidden characters portion 3 by dot g ₁ or the lines of the tilt angle, such as when no moire is generated moire Since the printed portion is formed, the hidden character portion 3 and the background portion 2 are visually recognized in the same color and cannot be visually recognized at the time of visual observation.
Alternatively, the hidden character portion 3 can be made visible on the copy paper 4 by moire generated on either side of the hidden character portion 3.

[0035]

As described above, according to the present invention, the halftone dots or lines of the background portion and the halftone dots or lines of the hidden character provided in the background portion have the same line density and the same shape. Since it is formed as a dot or a group of lines, it is not necessary to change the size or pitch of each dot or line group as in the related art, and printing can be easily performed.

Further, the background portion is formed by printing with moiré dots or lines having an inclination angle that does not generate moire or moire with respect to the reading reference direction.
At least one dot or line group having an inclination angle such that moiré is not generated when moire is generated in the dot or line group forming the background portion, and moire is generated when moire is not generated. Since the two hidden character portions 3 are formed by printing, each hidden character portion and the background portion are visually recognized in the same color and cannot be visually recognized at the time of visual observation. , The hidden character portion can be made to appear on the copy paper so as to be visible.

Therefore, even when a digital copier having a high resolution is used, the same copy as that of the copy paper is not performed.
It is possible to provide a method of preventing a counterfeit copy from being produced by a digital copier, which can make a difference portion appear on a copy sheet to clarify a difference from the copy sheet, and a copy sheet.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a printed matter according to the present invention.

FIG. 2 is an explanatory diagram showing a use state of a printed matter according to the present invention.

FIG. 3 is a diagram for explaining a contrast between a dot in a background portion and a dot in a hidden character portion;

FIG. 4 is an explanatory view showing another embodiment of a hidden character portion.

FIG. 5 is a schematic configuration diagram showing an analog copier.

FIG. 6 is a schematic configuration diagram showing a digital copier.

[Explanation of symbols]

2 Background 3 Hidden character g Background dot g ₁ Hidden character dot

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B42D 15/00 361 G03G 21/04

Claims (2)

(57) [Claims] 1. A digital copying machine in which a reading is performed in a reading reference direction .
Moire is generated on the copy paper when the copy paper is read, or n-line /
A background portion consisting of a first dot or line group having a line density of inch is printed and formed on a copy paper, and the same as the first dot or line group is placed in a desired portion of the background portion. it is a linear density with an inclination angle of so that to generate a moire when the first dot or line groups so as not to generate moire when Ru is generated moire and not to generate moire At least one hidden character portion consisting of a second halftone dot or line group formed by printing, and visually
The hidden character portion is visually recognized in the same color tone as the background portion and is not visually recognized. However, at the time of copying by the digital copying machine, the hidden character portion is visually recognized on the copy paper due to moire generated on either side of the background portion or the hidden character portion. A method for preventing the production of counterfeit copies by a digital copier, which is characterized in that it appears. 2. A digital copier according to claim 1, wherein said reading is performed in a reading reference direction.
Moiré is generated on the copy paper when it is removed, or n-line / inch with an inclination angle that does not generate moiré .
And the background portion printed formed by the first dot or line groups linear density, even during a desired portion of the background section, when the first dot or line group Ru generates a moire moire so as not to generate, also characterized by having a, a hidden text portion to be printed formed by the second dot or line group so that inclination angle is generated moire if not to generate moire Copy paper to prevent counterfeit products from being produced by digital copiers.