JP2007223100A - Information printed matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information printed matter which relates to a security medium requiring a countermeasure for forgery such as a gift certificate, a check, a credit card and an ID card, and in particular, on which a forgery preventive countermeasure whose validity judgement is visually performed with ease and which has a high security is applied. <P>SOLUTION: In order to realize the information printed matter whose validity judgement is easily performed and which has a higher forgery preventive effect than the conventional information printed matter having a diffraction grating pattern, the forgery preventive effect is improved by selectively performing a displaying of a picture pattern, characters or the like by the diffraction grating pattern, and a displaying of the information printed below the diffraction grating pattern in accordance with the angle of observation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to security media such as gift certificates, checks, credit cards, ID cards and the like that require countermeasures against counterfeiting, and in particular, a high-security counterfeiting countermeasure that facilitates authenticity determination with the naked eye is applied. Information printed matter.

In recent years, for the purpose of preventing counterfeiting of securities such as gift certificates and checks, cards such as credit cards, cash cards and ID cards, and identification cards such as passports and licenses, the diffraction grating pattern is used for the securities and cards. Affixed to the surface of certificates, etc.
The diffraction grating pattern can change the pattern or display a three-dimensional image according to the observation angle by controlling the direction, angle, brightness, and the like of diffracting light. The diffraction grating pattern has a directional gloss that cannot be expressed by ordinary printing technology, so it is widely used in printed information products that require anti-counterfeiting measures. It is demanded.

As a method for producing an original plate of this diffraction grating pattern, an XY stage on which a planar substrate coated with a photosensitive resist is moved by using an electron beam exposure apparatus and under computer control, There is a method of forming a diffraction grating pattern on the surface of a substrate (see, for example, Patent Documents 1 and 2).
Here, as a parameter of the diffraction grating,
(1) Spatial frequency of diffraction grating (pitch of grating line)
(2) Direction of diffraction grating (direction of grating line)
(3) Diffraction grating drawing area (arrangement of diffraction grating cells)
There are three.
And
In accordance with (1), the color at which the diffraction grating cell appears shining with respect to a fixed point changes,
In accordance with (2), the direction in which the diffraction grating cell appears shining changes,
In accordance with (3), a display pattern (picture, character, etc.) is determined.
Therefore, by dividing the surface of the substrate into small regions of about several tens to several hundreds of μm and changing these parameters for each region variously, it is possible to express a pattern, characters, or the like. In addition, a method of expressing a stereoscopic image with a sense of depth by arranging grid lines in an arc shape has been proposed (see, for example, Patent Document 3).

Further, as a diffraction grating, a rectangular diffraction grating 01 as shown in FIG. 10 or a sinusoidal diffraction grating 02 as shown in FIG. 11 is generally used for ease of processing, and a typical grating pitch is 0.5. About 2 μm, and the grating depth is about 0.1-1 μm.
A diffraction grating having a rectangular or sinusoidal cross-sectional shape is called a binary grating. However, in principle, this binary grating has a problem that the diffraction efficiency is low and a bright pattern cannot be obtained.
On the other hand, as shown in FIG. 12, the blazed grating 03 has a typical grating pitch and grating depth equivalent to those of a binary grating, but its cross-sectional shape is sawtooth and has a diffraction angle with respect to incident light from the vertical direction. Diffracted light having a theoretical diffraction efficiency of 100% is produced in that direction, and there is an optical effect that light is not emitted at other angles. In other words, the blazed grating has characteristics that it can obtain very high diffraction efficiency compared to the binary grating and that the traveling angle of light can be strictly controlled. Is preferred.

Also in the production of the blazed grating master, a method is used in which the shape of the blazed grating is formed on a planar substrate placed on a stage by using an electron beam exposure apparatus and by computer control. In order to form the sawtooth cross-sectional shape of the blazed grating, for example, by changing the irradiation time of the electron beam or adjusting the irradiation intensity according to the irradiation position of the electron beam, the depth of the groove to be processed A method has been proposed in which the shape of the blazed grating is obtained by changing the thickness (see, for example, Patent Document 3).
In addition, a method of etching with an ion beam using a plurality of mask patterns is known. Whichever blazed grating fabrication method is used, the fabrication difficulty is higher than that of the binary grating, and the fabrication technique is suitable for use in security applications.

Next, a metal stamper is produced by a method such as electroforming from an original plate having a concavo-convex shape produced by the above method, and this metal stamper is used as a matrix on a transparent substrate. A thermoplastic resin or a photo-curing resin is applied, a metal stamper is adhered, and the resin is cured by applying heat or light to replicate the diffraction grating pattern.
Since the duplicated diffraction grating pattern is usually transparent, a light reflecting layer is provided by a method such as vapor deposition of a metal or dielectric thin film layer such as aluminum, and then on a substrate such as paper or plastic film. A protective layer for preventing the printed layer and the diffraction grating pattern layer from being soiled and scratched is provided as necessary to produce securities and cards.
JP-A-2-72320 US Pat. No. 5,058,992 JP 2000-39508 A

  However, the diffraction grating pattern has come to be used for information printed matter that requires a lot of security, and as the technology is widely recognized, the occurrence of counterfeit products tends to increase. It has become impossible to exhibit a sufficient anti-counterfeit effect simply by pasting a lattice pattern on the surface of a substrate such as securities.

  Accordingly, an object of the present invention is to provide an information printed material that can easily and reliably determine authenticity by visual inspection and that makes it more difficult to produce a counterfeit product.

In order to achieve the above-described object, the printed matter of information of the present invention is provided with a printed layer, an adhesive layer, and a diffraction grating pattern forming layer composed of grating lines having a concavo-convex structure on the surface of a substrate made of paper or plastic. In the information printed matter, one surface of the concavo-convex structure constituting the lattice line has a light reflection layer, and a surface opposite to the one surface of the concavo-convex structure is a light transmission layer.
Further, in the information printed matter of the present invention, the diffraction grating pattern is constituted by a prismatic diffraction grating having a lattice line that is a triangular uneven structure having a continuous cross section, and one inclined surface of the uneven structure forming the lattice line is formed. It has a light reflection layer, and the inclined surface opposite to the light reflection layer is a light transmission layer.
The information printed matter of the present invention is characterized in that an angle formed by the apexes of the prismatic diffraction grating is 90 degrees or less.
Further, the information printed matter of the present invention is a blazed grating in which the diffraction grating pattern is composed of a lattice line having an asymmetric uneven structure including a gentle slope / a relatively steep slope, and the gentle slope reflects light. The steep slope is a light transmission layer.
Further, the information printed matter of the present invention is characterized in that the diffraction grating pattern is constituted by a diffraction grating having a function of displaying a stereoscopic image.

The information printed matter of the present invention has the following effects.
(1) On the surface of information printed matter such as securities, the display of brightly shining patterns and characters peculiar to the diffraction grating pattern and the display of patterns and characters by printing are switched according to the viewing direction and angle. Therefore, authenticity determination is easy and high security can be obtained.
(2) In particular, by using a diffraction grating having a prismatic cross section as a diffraction grating pattern, one inclined surface having a light reflecting layer of a grating line and an inclined surface which is a light transmitting layer opposite to the inclined surface are simultaneously recognized. As a result, there is no possibility that the pattern or character by the diffraction grating pattern and the pattern or character by printing will not be blurred at a certain observation angle, and the pattern or character or the like can be clearly switched and displayed.
(3) Also, using a blazed grating as the diffraction grating pattern and providing a light reflection layer only on a gentle slope, displays a high-intensity diffraction grating pattern with a higher anti-counterfeit effect, and displays images and characters by printing Can be switched.
(4) Further, when a stereoscopic image is displayed by the diffraction grating pattern, the observation angle at which the stereoscopic image is inverted becomes an observation angle at which the printed pattern can be recognized, and the angle at which the diffraction grating pattern can be observed and the printed pattern can be observed. Since the angle is clear, authenticity determination can be performed easily and reliably.

  In the embodiment of the present invention, in order to realize an information printed matter that is easy to determine authenticity and has a higher anti-counterfeit effect than an information printed matter having a conventional diffraction grating pattern, display of patterns, characters, etc. by the diffraction grating pattern And an information printed matter that can selectively display information printed on the lower part of the diffraction grating pattern according to the observation angle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan view showing an example of an information printed matter in which a diffraction grating pattern according to an embodiment of the present invention is pasted on the surface of a substrate.
In the drawing, the base material 04 of the information printed material is a sheet or flat base material such as paper or a plastic plate or a plastic film, and a diffraction grating pattern 05 is attached to an arbitrary region on the surface of the base material 04. Yes. The diffraction grating pattern 05 is not limited to a rectangular shape as shown in FIG. 1, but a circular or elliptical shape, a belt-like shape that traverses / cuts vertically on the base material 04, or the entire surface of the base material 04. It is affixed in various forms, such as covering everything.

As shown in FIG. 2, a general layer structure of an information printed matter on which a diffraction grating pattern is affixed is as follows. A printed layer 06 is applied on a base material 04, and a diffraction grating pattern 05 is formed thereon via an adhesive layer 07. Exists.
Note that the diffraction grating pattern 05 is usually formed of a thermoplastic resin or a photocurable resin and is transparent, so that a light reflection layer 08 is provided in order to efficiently diffract and emit incident light from the outside. It is often done. The light reflecting layer 08 is a metal layer formed by a method such as vapor deposition or sputtering, or a dielectric thin film layer. Furthermore, a protective layer 10 is provided as necessary to protect the layer of the diffraction grating pattern 05. When the information printed matter is a credit card, an ID card, or the like, a layer for preventing warping of the base material 04 or a layer for improving adhesion of printing ink may be provided. Further, a separate magnetic film layer or the like may be provided on the substrate 04. Even when the base material is paper, layers having various functions are provided as necessary.

In the information printed matter to which the diffraction grating pattern realized by such a configuration is attached, in the region where the diffraction grating pattern 05 is attached, only the pattern by the light diffracted from the light reflection layer 08 formed on the diffraction grating pattern 05 is provided. The pattern and characters printed on the lower surface of the area of the diffraction grating pattern 05 are not recognized and cannot be recognized at all.
Therefore, the design, characters, etc. printed on the printing layer 06 are shielded, information is lost, and the continuity of the printed design is lost, resulting in a problem in design. In addition, the diffraction grating pattern provided with a light reflecting layer is used in various products and is a common one. Therefore, simply removing the product and applying it to the surface of a forged information printed material is simple. Can be produced.

Therefore, by providing a light reflecting layer on one surface of the concavo-convex structure constituting each grating line of the diffraction grating pattern and making the opposite surface a light transmitting layer, the conventional light reflecting layer is uniformly provided on the entire surface. It realizes functions that are impossible for a diffraction grating pattern.
FIG. 3 shows an example in which the light reflecting layer 08 is provided on one surface of the concavo-convex structure of the lattice line, and the light transmitting layer 09 is provided on the opposite surface.
As shown in the figure, in this example, a light reflection layer 08 is provided on one slope 11 of a lattice line having a sinusoidal cross-sectional shape, and a light transmission layer is provided on the opposite slope 12 without a light reflection layer.
For example, when the incident light 13 is vertically incident on the diffraction grating pattern having such a configuration, ± n-order diffracted lights 14 to 17 are formed at angles uniquely determined by the pitch of the grating lines, the wavelength of the incident light 13, and the incident angle. It is injected.

For example, when the diffraction grating pattern is observed at the position 18 where the + 1st-order diffracted light 14 is emitted, a bright and glossy pattern by the diffracted light is recognized. Further, when the diffraction grating pattern is observed at the position 19 where the diffracted light is not emitted, the diffracted light is not observed and only the color of the light reflecting layer is recognized.
Furthermore, when the pattern by the diffracted light is observed at the position 20 where the −1st order diffracted light on the side of the inclined surface 12 having no light reflecting layer is emitted, when the diffraction grating pattern is observed at the position 21 where the diffracted light is not emitted, the inclined surface 12 is obtained. Has transparency, so that the state of the lower part of the diffraction grating pattern can be recognized without recognizing the diffracted light or the color of the light reflecting layer.

By attaching such a diffraction grating pattern, on which the presence or absence of the light reflecting layer is controlled according to the orientation of the surface of the concavo-convex structure constituting the grid line, to the surface of the information printed matter, display of patterns, characters, etc. by diffracted light And can be switched according to the angle of the incident light and the observation position of the pattern, characters and the like of the print layer.
As shown in FIG. 4 (a), when the printed information product 21 is observed at an arbitrary angle, a pattern by the diffraction grating pattern 05 is observed, and when observed from another angle, it is shown in FIG. 4 (b). As described above, in the region where the diffraction grating pattern 05 is affixed, information such as a picture printed under the diffraction grating pattern can be read.

  Next, as a method of providing a light reflecting layer only on one surface of the concavo-convex structure of the grating line, as shown in FIG. It is arranged in the direction, heated and vaporized, and a method of providing the light reflecting layer 08 by vapor deposition on the surface 11 or a minute slit 23 provided on the front surface of the diffraction grating pattern 05 as shown in FIG. For example, there is a method in which after the mask 24 is closely fixed, vapor deposition is performed, and a light reflection layer is provided only at the opening.

Note that it is more desirable to use a prismatic (triangular) shape as shown in FIG. 7 instead of the sinusoidal shape as shown in FIG.
Also, in order to switch clearly between the display of the pattern etc. by the diffraction grating pattern and the picture by printing, the direction of the surface of the concave / convex structure of the grid line needs to be different, but in the case of a sine wave cross section, the concave / convex shape 3 is rounded, and the light reflection layer 08 is perceived slightly even on the observation position 20 side in FIG.
On the other hand, in the case of a prism-shaped cross section, as shown in FIG. 7, the surface 11 having the light reflecting layer is not perceived on the observation position 20 side, and only the pattern of the printed layer can be recognized. Further, when the angle 24 formed by the apex portion of the prism-shaped diffraction grating is 90 degrees or less, the surface 12 side where the light reflecting layer is not provided when forming the light reflecting layer by vapor deposition from an oblique direction as shown in FIG. It can be expected to reduce the influence of evaporation material that has been vaporized.

In addition, when the diffraction grating pattern is configured by a blazed grating having a grating line that is an asymmetric uneven structure including a gentle slope and a relatively steep slope, an information printed matter with a higher anti-counterfeiting effect can be realized. Can do.
Since the blazed grating emits strong diffracted light only in one arbitrary direction and hardly emits diffracted light in the other directions, the light is reflected on the gentle slope 25 of the blazed grating as shown in FIG. By providing the layer 08 and the steep slope 26 as the light transmitting layer 09, the pattern by the diffraction grating pattern becomes very bright and glossy, and printing is performed in the region 20 where the surface 26 side of the light transmitting layer 09 can be observed. You can observe the pattern.
When the binary grating is used, there is a position where the diffracted light is observed on the surface 26 side of the light transmission layer 09. However, since the blazed grating hardly emits the diffracted light on the surface 26 side, the pattern by the diffracted light is observed. It is possible to more clearly separate the area and the area where the printed pattern is observed. In addition, since the blazed grating is difficult to produce as compared with the binary grating, a high anti-counterfeiting effect can be expected.

Further, when the pattern expressed by the diffraction grating is a stereoscopic image having a sense of depth, it can be expected that the authenticity determination can be easily and reliably performed. In general, there are many three-dimensional images represented by diffraction grating patterns, such as human busts, characters such as animals, corporate logo marks, etc., and the top and bottom directions are determined in advance, and the observation angle is also determined in advance. In general, it is rare to observe a stereoscopic image at other angles.
Therefore, a light reflection layer is applied to the surface of the lattice line that enters the viewer's field of view at the angle at which the stereoscopic image is observed, and the surface of the lattice line that does not enter the viewer's field of view has light transparency. As shown in FIG. 9A, when the vertical direction of the information printed material and the angle at which the stereoscopic image is observed are the same, the stereoscopic image 27 is observed in the region of the diffraction grating pattern 05. As shown in FIG. When an image is not observed at an angle, for example, when the information print is upside down, the printed pattern or characters can be observed in the region of the diffraction grating pattern 05.
Since the angle at which the printed pattern can be observed can be easily determined from the information on the top and bottom direction of the stereoscopic image, even a person unfamiliar with the authenticity determination can surely make the determination. As a diffraction grating pattern for displaying a stereoscopic image, any of a binary grating, a diffraction grating having a prism type cross section, and a blazed grating can be used.

  In the above embodiment, the diffraction grating pattern 05 is attached to a part of the substrate 04. However, the diffraction grating pattern 05 is attached to the entire surface of the substrate 04. It doesn't matter.

It is explanatory drawing which shows an example of the information printed matter to which the diffraction grating pattern by embodiment of this invention was affixed. It is sectional drawing which shows the layer structure of the information printed matter with which the diffraction grating pattern shown in FIG. 1 was affixed. It is explanatory drawing which shows an example of the diffraction grating pattern which provided the light reflection layer in one surface of the uneven | corrugated structure of a lattice line, and made the opposing surface the light transmissive layer. (A) is an external view which shows the information printed matter seen from the position where the pattern by a diffraction grating pattern is observed, (b) is the information printed matter seen from the position where the pattern by printing of the lower part of a diffraction grating pattern is observed. FIG. It is explanatory drawing which shows the vapor deposition method which has arrange | positioned the diffraction grating pattern diagonally. It is explanatory drawing which shows the vapor deposition method which closely_contact | positioned the mask which provided the slit in the diffraction grating pattern. It is explanatory drawing which shows a mode that the light reflection layer was provided in one surface of the diffraction grating pattern which has a cross section of a prism (triangle shape). It is explanatory drawing which shows a mode that the light reflection layer was provided in the gentle slope of a blazed grating. (A) is an external view which shows the information printed matter seen from the position where the stereoscopic image by a diffraction grating pattern is observed, (b) is the external appearance which shows the information printed matter which looked at the pattern by printing from the direction where a stereoscopic image is not observed. FIG. It is sectional drawing which shows the prior art example of the binary lattice which has a rectangular cross section. It is sectional drawing which shows the prior art example of the binary grating | lattice which has a sinusoidal cross section. It is sectional drawing which shows the prior art example of the blazed grating | lattice with a sawtooth-shaped cross section.

Explanation of symbols

04: Base material, 05: Diffraction grating pattern, 06: Print layer, 07: Adhesive layer, 08: Light reflection layer, 09: Light transmission layer, 10: Protection layer, 11, 12 ... Diffraction grating surface, 13: incident light, 14: + 1st order diffracted light, 15 ... + 2nd order diffracted light, 16 ...- 1st order diffracted light, 17 ...- 2nd order diffracted light, 18-20: observation position, 21 …… Information printed material, 22 …… Vapor deposition material, 23 …… Slit, 24 …… Mask, 25 …… Slow slope of blazed grating, 26 …… Steep slope of blazed grating, 27 …… Stereoscopic image.

Claims (6)

On the surface of the base material is an information printed matter provided with a printed layer, an adhesive layer, and a diffraction grating pattern forming layer composed of grating lines having a concavo-convex structure,
One surface of the concavo-convex structure constituting the lattice line has a light reflection layer, and the surface opposite to the one surface of the concavo-convex structure has a light transmission layer,
Information printed matter characterized by that.   2. The information printed matter according to claim 1, wherein the substrate is a sheet or flat substrate made of paper or plastic.   The diffraction grating pattern is constituted by a prismatic diffraction grating having a lattice line that is a triangular uneven structure having a continuous cross section, and one inclined surface of the uneven structure forming the grating line has a light reflection layer, 2. The information printed matter according to claim 1, wherein the opposing inclined surfaces are light transmitting layers.   The information printed matter according to claim 3, wherein an angle formed by the apexes of the prismatic diffraction grating is 90 degrees or less.   The diffraction grating pattern is a blazed grating composed of a grating line that is an asymmetrical concavo-convex structure composed of a gentle slope / a relatively steep slope, the gentle slope having a light reflecting layer, and the steep slope. The information printed matter according to claim 1, wherein the slope is a light transmission layer. The information printed matter according to any one of claims 1 to 5, wherein the diffraction grating pattern is configured by a diffraction grating having a function of displaying a stereoscopic image.

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