JP2002254868A - Anti-counterfeit sheet - Google Patents

Abstract

(57) [Summary] [Problem] To provide a sheet for preventing forgery of gift certificates, stock certificates, various cards, etc., which is easy and reliable to judge whether it is true or not and which is difficult to forge. SOLUTION: The gift certificate 1 which is a forgery prevention sheet is provided with a small transmission portion having an arbitrary shape such as an animal form or a star form other than a conventional circular, elliptical or square shape. By passing through a mask formed with a, a small through hole 5 such as a dog-shaped member having the same shape as the transmitting portion and having a shape that is difficult to identify with the naked eye is provided on the sheet surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forgery prevention sheet, and more particularly to a sheet such as a stock certificate, a bond, a gift certificate, or an ID card which requires forgery prevention.

[0002]

2. Description of the Related Art In a conventional sheet for preventing forgery of this kind,
First, a watermark for preventing forgery is inserted, or an identification mark is printed with a special ink, and the watermark or the identification mark is visually confirmed to judge authenticity. Also, the second
In addition, although it is usually difficult for the naked eye to visually recognize the identification mark, it is also performed to print an identification mark that can be visually recognized by copying, and determine whether the identification mark is true or false based on whether or not the identification mark can be visually recognized.

[0003]

However, according to the first conventional example, due to the recent high performance of color copiers and the improvement of printing technology, counterfeit products which are difficult to judge at first glance are difficult. There is a disadvantage that it may be created. According to the second conventional example, although it is difficult to see with the naked eye, it can be seen when observed carefully, and it may cause a sense of visual discomfort. There is a disadvantage that it becomes the above constraint. An object of the present invention is to provide a forgery prevention sheet that has solved such inconveniences.

[0004]

In order to achieve this object, a sheet for preventing forgery according to claim 1 of the present invention comprises:
Laser light is not circular, elliptical, square,
By irradiating through a mask that has a small transparent part with an arbitrary shape such as an animal form or a star-shaped form, it is possible to identify a small part of the sheet surface with the same shape as the transparent part by irradiating it with a mask. Are provided with through-holes or recesses which are difficult to achieve.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment in which the present invention is applied to a department store gift certificate will be described below with reference to the accompanying drawings. Here, FIG. 1 is a schematic plan view of a gift certificate, FIG. 2 is a schematic partial enlarged sectional view of the same, FIG. 3 is a schematic partial enlarged plan view of a through-hole part, and FIG. FIG.

As shown in FIG. 1, a gift certificate 1 has a title 2 "gift certificate" and "gold ten thousand yen,
000 "and a face value display 3 displayed in upper and lower two rows and an issuer display 4 of" @Department Co., Ltd. "are provided by printing.

[0007] In the upper right part of the gift certificate 1, eight through holes 5 (see FIG. 2) for judging the authenticity are formed by laser light. Since these through holes 5 are minute, their shapes cannot be identified with the naked eye, and can only be identified as mere points.
When enlarged, as shown in FIG. 3, it has the shape of a dog.

As shown in FIG. 4, a laser beam 11 emitted from a laser oscillator 10 is transmitted through a beam expander 14 to a small dog-shaped transmitting portion (not shown).
Through the transmission type liquid crystal mask 12 formed with
The transmitted laser light 13 passes through a condenser lens 15 for adjusting the size to a predetermined minute size, and irradiates the surface of the gift certificate 1 so that the transmitted laser light 13 is formed in a state where it is difficult for the naked eye to identify the shape. Things. The transmitted laser light 13
Has passed through the transmissive part, so that the cross-sectional shape becomes the same dog shape as the transmissive part, whereby the shape of the through hole 5 formed in the gift certificate 1 also becomes the same dog shape.

More specifically, for example, eight dog-shaped transmission portions are formed at predetermined positions of the transmission type liquid crystal mask 12, and the laser oscillator 10 is moved in the X and Y directions to transmit the laser light. A plurality of through-holes 5 are formed by transmitting the light through the respective transmission portions. Further, for example, a transmission portion in the form of one dog is formed at a predetermined position of the transmission type liquid crystal mask 12, and the gift certificate 1 is moved in the X and Y directions, and the laser beam transmitted through each of the transmission portions is formed. The plurality of through holes 5 can be formed by irradiating the predetermined position of the gift certificate 1 with the 11.

As the laser oscillator 10, a carbon dioxide gas laser oscillator, an excimer laser oscillator, a YAG laser oscillator, or the like can be used. The laser is not limited to a specific laser, but is selected according to the material of the sheet base material. . In the case of gift certificate 1, a commercially available carbon dioxide laser oscillator was used. In addition, this carbon dioxide gas laser oscillator has a through hole 5.
In order to form the sheet, the frequency of 1 KH is applied to the sheet base material (NIP paper: continuous weight 70 kg) of the gift certificate 1 of the present embodiment.
Laser irradiation was performed under the conditions of z and output of 4 W. In the case where a concave portion was formed instead of the through hole 5, an output of about 2 W was sufficient at the same frequency using the same device.

In the present embodiment, the through hole 5 of the gift certificate 1
By magnifying a magnifying glass with a magnifying glass, it can be determined that the shape is a true dog if the shape is a specific dog, and a fake if the shape is other than this. Since it is difficult to form a specific dog shape and create a counterfeit product, it has a deterrent effect on counterfeit product creation and can contribute to the prevention of counterfeiting.

The present invention is not limited to the embodiment described above. For example, the present invention can be applied not only to the gift certificate 1 but also to various securities, banknotes, and various cards. The material is not limited to synthetic paper, plastic or metal. Also, the shape of the through-holes and recesses,
Conventionally formed by irradiating laser light without passing through a mask having a transmission part of any shape, a conventional ordinary circular, elliptical,
The shape is not limited to a square shape, and may be a shape such as a plant, a person, or various marks in addition to various animals and stars.

[0013]

As described above, according to the anti-counterfeit sheet according to claim 1 of the present invention, laser light
It can only be seen as a point with the naked eye, but it is actually circular, elliptical,
By forming a small through-hole or recess having an arbitrary shape such as an animal form or a star-like form, which is not a square shape, on a sheet substrate, the formed minute through-hole or recess is magnified (magnified). If you look at it with a mirror, etc., you can easily and surely judge the authenticity, and it is difficult to create counterfeit products. Play.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a gift certificate.

FIG. 2 is a schematic partial enlarged sectional view of a gift certificate.

FIG. 3 is a schematic partial enlarged plan view of a through-hole portion of the gift certificate.

FIG. 4 is a schematic explanatory view showing a laser processing state.

[Explanation of symbols]

 1 Gift Certificate 5 Through Hole 10 Laser Oscillator 12 Transmissive Liquid Crystal Mask

Claims (1)

[Claims] 1. Irradiating a laser beam by passing through a mask having a small transmission portion having an arbitrary shape such as an animal or star shape instead of a circular, elliptical or square shape, A forgery prevention sheet, wherein a predetermined portion of a sheet surface is provided with a through hole or a concave portion having the same shape as the transmitting portion and minute and difficult to identify the shape with the naked eye.