Source: https://patents.google.com/patent/JP2000318399A/en
Timestamp: 2020-04-08 22:55:37
Document Index: 88166447

Matched Legal Cases: ['art 4', 'art. 3', 'art 3', 'art 4', 'art 5', 'art\n1']

JP2000318399A - Forgery preventive sheet - Google Patents
Forgery preventive sheet
JP2000318399A
JP2000318399A JP11126903A JP12690399A JP2000318399A JP 2000318399 A JP2000318399 A JP 2000318399A JP 11126903 A JP11126903 A JP 11126903A JP 12690399 A JP12690399 A JP 12690399A JP 2000318399 A JP2000318399 A JP 2000318399A
JP11126903A
1999-05-07 Application filed by Toppan Printing Co Ltd, 凸版印刷株式会社 filed Critical Toppan Printing Co Ltd
1999-05-07 Priority to JP11126903A priority Critical patent/JP2000318399A/en
2000-11-21 Publication of JP2000318399A publication Critical patent/JP2000318399A/en
PROBLEM TO BE SOLVED: To visually check the genuineness of a copy to judge whether or not the copy in forged by a method wherein a cholesteric liquid crystal part, which is transparent by a visual inspection, is provided on a white or colorless transparent portion of a base material, while a printing part, which is visible with the naked eyes, is provided on a portion of the base material other than the white or colorless transparent portion thereof. SOLUTION: A base material constituting the forgery preventive sheet 1 comprises a white or colorless transparent portion 3 and a portion 5 of the sheet 1 excluding the portion 3. On the portion 3, there is provided a cholesteric liquid crystal part 4, which has a polarizing property different from that of the portion 3 and is transparent by a visual inspection. And on the portion 5, there is provided a printing object 2 which is visible with the naked eyes. Thus, the genuineness of a copied matter which is forged by means of a color copying machine or a personal computer printer can be easily checked by a visual inspection using a polarizing plate.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to paper used for various products which require forgery prevention,
In particular, the present invention relates to a forgery prevention sheet that can easily determine the authenticity even if the forgery is attempted by copying using a color copying machine or a personal computer printer.
2. Description of the Related Art In recent years, copiers, especially color copiers, have made remarkable progress in function, and use these copiers and color copiers to copy printed matter such as securities.
There are many cases of abuse. In response to such a case, a forgery prevention technology employing copy prevention means utilizing the characteristics of a copying machine has been developed.
For example, 1) printing using an ink using a coloring material having a sharp peak in its spectral reflectance curve, and reproducing this image in color to reproduce a different color tone; 2) forming an image A part of the line is set in a direction that does not overlap with the scanning direction due to the scanning of the copying machine, thereby forming an image in which only a part of the line different from the scanning direction appears to be raised in the copy, 3). When an image is provided by combining a halftone dot and a line, it is reproduced by emphasizing the difference between the halftone dot and the line by copying. 4) A micro character having a resolution lower than the resolution of the copying machine is provided as an image. At the time of copying, micro characters are not resolved and the reproduction becomes difficult. 5) Part of the printed image is printed using magnetic ink, and the presence or absence of this magnetic part is checked. And 6) determining the authenticity by knowing it, 6) providing an image with an ink that causes a change in the observed color (color shift) according to the viewing angle of the printed matter, so that it cannot be reproduced by a copying machine. 7) An image is provided with black ink that has no absorption in the infrared region, and authenticity is determined based on the presence or absence of infrared absorption in the black portion. 8) Characters, images, designs, etc. are provided with special ink and their detection is performed. And 9) a paper with a watermark on it.
However, due to improvements in resolution and color reproducibility due to advances in copiers and color copiers, the effects of the above-described forgery prevention technology, which has been conventionally difficult, are disappearing. In addition, when the above-mentioned magnetism, infrared rays and the like are used, there is a disadvantage that the authenticity cannot be determined without using such a detection device. Further, in the above-mentioned paper having a watermark, for example,
As shown in JP-A-912295 and JP-A-6-280198, there is a risk of forgery using a watermark technique.
[0005] Therefore, when the authenticity of a copy obtained by copying a printed matter such as a security using a copying machine or a color copying machine is determined, it is particularly easy to visually determine the authenticity. In order to do so, it is important that there is a clear difference that is easier to judge, and it is desired to provide such a judgment means.
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and visually checks the authenticity of a copy which has been attempted to be forged by copying using a color copying machine or a personal computer printer. An object of the present invention is to provide a forgery prevention sheet that can be easily performed.
According to the present invention, there is provided a cholesteric liquid crystal portion having a polarization property different from that of a white or colorless transparent portion on a white or colorless transparent portion of a substrate, which is transparent when viewed with the naked eye. The forgery prevention paper is characterized in that a printed portion that is visible with the naked eye is provided on a portion other than the white portion or the colorless transparent portion of the material.
Embodiments of the present invention will be described below. FIG. 1 is a plan view showing an embodiment of a forgery prevention sheet according to the present invention. As shown in FIG. 1, the base material (1) constituting the anti-counterfeit paper is composed of a white or colorless transparent part (3) and a part (5) other than the white part or colorless transparent part. 3) A cholesteric liquid crystal part (4) having a polarizing property different from that of the white or colorless transparent part and transparent by the naked eye is provided on the upper part, and a part other than the white part or the colorless transparent part (5) is provided on the upper part. Is provided with a printing unit (2) that is visible with the naked eye.
As the substrate (1), for example, paper, plastic, cloth, wood, glass and the like can be used. The printing unit (2) is provided so that the picture can be observed visually with the naked eye. The printing unit (2) is a direct gravure printing method, a reverse gravure printing method, an offset printing method, a screen printing method, a flexographic printing method using a generally known printing ink. It can be provided by printing such as a printing method.
When the white or colorless transparent portion (3) is white, there are a method of using a white material by itself and a method of applying a white ink on a material of another color. As this material, paper or plastic is preferably used, but cloth, wood, glass, or the like can be used depending on the application.
When the white or colorless and transparent portion (3) is colorless and transparent, the colorless and transparent material may be polypropylene,
Polyethylene terephthalate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-
Examples include synthetic resins such as vinyl alcohol copolymers, polyesters, polycarbonates, polyacrylates, polymethacrylates, polystyrenes, and the like, and glass, etc., which can be used according to the intended use.
The cholesteric liquid crystal part (4) has a different polarization property from its surroundings, that is, from the white or colorless transparent part (3). This cholesteric liquid crystal part (4)
Although the cholesteric liquid crystal part (4) can be easily observed by the naked eye with the same white or colorless and transparent as the surroundings, the cholesteric liquid crystal part (4) can be easily observed by using a polarizing plate. However, since it is impossible to reproduce such a cholesteric liquid crystal part (4) in a copy using a copying machine, the authenticity of the copy can be easily determined.
Cholesteric liquid crystals are stacked in such a manner that molecules are arranged in parallel in layers and the molecular axis direction is slightly rotated for each layer. For this reason, light passing through this cholesteric liquid crystal layer selectively polarizes light having a wavelength about twice the layer spacing of the stacked molecules, further reflects the right circularly polarized light component, and reflects the left circularly polarized light component. And has the property of transmitting light of other wavelengths. Specifically, the layer interval is about 230 n
At the time of m, blue light having a wavelength about twice as long as that, green light at about 270 nm, and red light at about 330 nm are selectively polarized.
When the white or colorless transparent portion (3) in which the cholesteric liquid crystal is provided is white, the transmitted light component is also reflected, so that it can be seen as a mere white portion by naked eyes. However, the presence of the cholesteric liquid crystal, that is, the cholesteric liquid crystal part (4) can be easily observed by visual observation using a polarizing plate.
Further, when the white or colorless transparent portion (3) is colorless and transparent, if the light entering from the back is stronger than the reflected light component, the color of the reflected light is hardly perceivable and is transparent. looks like. However, the presence of this cholesteric liquid crystal by visual observation using a polarizing plate, or by placing a black background without using a polarizing plate,
That is, the cholesteric liquid crystal part (4) can be easily observed.
As a method of providing the cholesteric liquid crystal, an image of the cholesteric liquid crystal may be provided on the white or colorless transparent portion (3), or a part of the cholesteric liquid crystal may be changed in molecular interval by heating or the like and used as an image. You may.
The present invention will be described in detail with reference to the following examples. <Example 1> White high-quality paper (90 kg) was used as a base material, and a printing portion was provided thereon by an offset printing method using process ink. Next, a pattern made of cholesteric liquid crystal was provided at a thickness of about 50 μm by a screen printing method in a portion different from the printed portion, and a 50 μm transparent polyethylene terephthalate film was laminated via a urethane-based adhesive to protect the surface. Thermal bonding was carried out with a hot roller at ℃. <Example 2> 250 μm subjected to easy adhesion treatment as a substrate
A thick transparent polyethylene terephthalate resin film was used. A forgery prevention sheet was prepared in the same manner as in Example 1.
When the anti-counterfeit paper prepared as described above was observed using a commercially available polarizing plate, a pattern of cholesteric liquid crystal was observed as a pattern in both Examples 1 and 2. In Example 2, a pattern was observed even when black paper was placed on the back surface. Therefore, it was proved that the anti-counterfeit papers according to these examples can be authenticated without using a special detecting device.
Next, both were copied in a normal mode of a commercially available color copying machine. When the copy density was low, the blank paper was simply discharged, but when the copy density was high, the pattern of the cholesteric liquid crystal was copied as a very thin pattern. And I observed the copy through a polarizing plate,
No pattern was observed. In other words, it was found that it is easy to determine whether or not a copy is a copy because only a complete blank sheet or a very thin pattern is formed. From the above, it has been proved that the authenticity of a copy can be easily determined by a copying machine.
According to the present invention, there is provided a cholesteric liquid crystal portion having a polarization property different from that of the white or colorless transparent portion on the white or colorless transparent portion of the base material, the cholesteric liquid crystal portion being visible to the naked eye. Or on the part other than the colorless transparent part,
Since it is a forgery-prevention paper with a printed part that can be visually observed with the naked eye, it is easy to visually check the authenticity of a copy that has been forged by copying with a color copier or personal computer printer, etc., visually using a polarizing plate. It is a forgery prevention paper that can be used.
FIG. 1 is a plan view showing an embodiment of a forgery prevention sheet according to the present invention.
1 base material 2 printed part 3 white or colorless transparent part 4 cholesteric liquid crystal part 5 part other than white part or colorless transparent part
1. A cholesteric liquid crystal part having a polarizing property different from that of a white or colorless transparent part and transparent by the naked eye is provided on the white or colorless transparent part of the base material, and the white part or colorless transparent part of the base material is provided. A forgery-prevention paper characterized in that a printing part which can be visually observed by naked eyes is provided on a portion other than the above.
JP11126903A 1999-05-07 1999-05-07 Forgery preventive sheet Pending JP2000318399A (en)
JP11126903A JP2000318399A (en) 1999-05-07 1999-05-07 Forgery preventive sheet
JP2000318399A true JP2000318399A (en) 2000-11-21
ID=14946751
JP11126903A Pending JP2000318399A (en) 1999-05-07 1999-05-07 Forgery preventive sheet
JP (1) JP2000318399A (en)
1999-05-07 JP JP11126903A patent/JP2000318399A/en active Pending
CN1630892B (en) * 2002-02-12 2011-06-08 日本发条株式会社 Identifying medium and identifying method for object
NL192610C (en) 1997-11-04 Image carrier and method for printing on an image carrier of an image.