JP4832191B2 - Anti-counterfeit media - Google Patents

Description

  The present invention relates to an anti-counterfeit medium such as an anti-counterfeit sheet, and more particularly to an anti-counterfeit structure using a latent image.

  In the past, counterfeit crimes have frequently occurred in securities such as prepaid cards, various admission tickets, gift certificates and stock certificates because they are widely distributed and can be exchanged relatively easily. In particular, in recent years, with the improvement and popularization of copying machines such as color copiers, counterfeit products that cannot be easily distinguished from genuine products can be manufactured relatively easily, and countermeasures against counterfeiting are required. Yes. Moreover, measures against counterfeiting are required not only for the above-mentioned securities but also for banknotes.

  As one of countermeasures against such counterfeiting, a technique that enables authenticity determination of securities and banknotes using a latent image is considered, and is disclosed in, for example, Patent Document 1.

  The technique disclosed in Patent Document 1 includes a plurality of printed lines on a sheet base material, parallel to the printed lines, a part extending in a direction orthogonal to the printed lines, and a cross section The raised relief lines are provided to raise the latent image depending on the observation direction. When the substrate is viewed from the front, all the printed lines are visible. However, when the observation direction is changed to a direction perpendicular to the printed lines and the relief lines, the portion of the printed lines where the relief lines extend is visible behind the extended relief lines. While not possible, the other parts of the printed line remain visible. Thereby, a latent image corresponding to the shape of the relief line can be raised.

In this way, in the case of a sheet base material provided with a relief line with a raised cross section, the printed information including the printed line printed on the surface is copied, but the raised shape of the relief line is reproduced. Can not. For this reason, even when the observation direction of the copy is changed, the latent image does not appear, thereby making it possible to determine authenticity.
JP 2000-313161 A

  However, as described above, on the sheet base material, a plurality of printed lines, parallel to the printed lines, a part extends in a direction perpendicular to the printed lines, and the cross-section is raised. In the case where a relief line is provided and a latent image is raised by the printed line and the relief line, the latent image only appears when viewed from a direction perpendicular to the printed line and the relief line. It is hard to say that it is easy to determine authenticity by image. In particular, when the observation direction is limited, there is a possibility that the authenticity determination based on the latent image cannot be performed.

  The present invention has been made in view of the problems of the conventional techniques as described above, and provides a forgery prevention medium that can easily perform authenticity determination by a latent image without being limited to an observation direction. The purpose is to provide.

In order to achieve the above object, the present invention provides:
A plurality of recesses formed to be recessed from the substrate surface;
A first mark portion provided at a position that is a first depth from the surface of the base material of a predetermined recess among the plurality of recesses;
A position that is similar to the first mark portion and has a second depth different from the first depth from the surface of the base material of the concave portion in which the first mark portion is not provided among the plurality of concave portions. And a second mark portion provided in the
Each of the plurality of recesses has its inner surface facing an oblique direction with respect to the normal of the substrate surface so that its cross-sectional area becomes narrower as it moves away from the boundary portion with the substrate surface. And
At least one of the first mark portion and the second mark portion is provided over the entire circumference of the inner surface of the recess.

  In the present invention configured as described above, when the substrate is observed from the front, the first mark portion and the second mark portion provided in the plurality of recesses are not obstructed from the observation direction. All the first mark portions and the second mark portions are visually recognized. Although the first mark portion and the second mark portion have different depths from the surface of the base material, they are similar to each other and are observed in the depth direction, so that they have substantially the same shape. As a result, it is difficult to distinguish between the first mark portion and the second mark portion, and it is recognized that the mark portions having the same shape are formed side by side. From this state, the observation direction is changed to a direction that forms an acute angle with respect to the substrate surface. When the angle formed by the observation direction with respect to the substrate surface is smaller than a predetermined angle, the recesses are provided with different depths. Of the first mark portion and the second mark portion thus formed, the deeper mark portion in the recess is hidden by the surface of the base material on the observation direction side of the recess, so that the depth in the recess is reduced. Only the shallower mark is visible. For this reason, if a plurality of first mark portions are provided in a predetermined concave portion among the plurality of concave portions so that predetermined information serving as a latent image is expressed, it is more than a predetermined angle with respect to the substrate surface. When observed from a direction forming a small angle, the latent image using the first mark portion appears to appear. Here, in the present invention, the first mark portion and the second mark portion are similar to each other, and at least one of them is provided over the entire circumference of the inner surface of the recess. The latent image using the first mark portion appears to appear when viewed from any direction that forms an angle smaller than a predetermined angle with respect to the material surface. In addition, since the first mark portion and the second mark portion are similar to each other, it is difficult to distinguish between the first mark portion and the second mark portion when the substrate is observed from the front. The latent image using the first mark portion can be made difficult to recognize.

  As described above, in the present invention, the first mark portion and the second mark portion constituting the latent image that emerges when observed from any direction that forms an angle smaller than a predetermined angle with respect to the substrate surface. Are similar to each other, and at least one of them is provided over the entire circumference of the inner surface of the recess formed in the substrate, so that the latent image emerges without being restricted in the observation direction. It is possible to easily determine whether the image is true or false.

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

(First embodiment)
FIG. 1 is a diagram showing an anti-counterfeit sheet as a first embodiment of the anti-counterfeit medium of the present invention, (a) is a diagram showing the entire configuration, and (b) is a forgery shown in (a). The figure which shows the detailed structure of the prevention structure 10, (c) is AA 'sectional drawing shown in (b), (d) is a figure which shows the structure of the recessed part 11 in which the character part mark 12 was provided, (e) ) Is a diagram showing the configuration of the recess 11 provided with the background mark 13.

  As shown in FIG. 1, the forgery prevention sheet 1 of the present embodiment is configured by providing a forgery prevention structure 10 in a partial region of a sheet base 2 made of paper. The sheet base material 2 has a flat surface portion 3 that becomes the surface of the base material, and an information printing region 4 is provided in a partial region of the flat surface portion 3 and a forgery prevention structure 10 is provided in another region. . The anti-counterfeit sheet 1 configured in this manner can be used as an entrance ticket for a concert, for example. In this case, the contents of the concert, the venue name, the seat number, etc. are printed in the information printing area 4. In addition, before the information is printed in the information printing area 4 of the sheet base material 2, it may be possible to print a tint block or precolor the sheet base material 2 as a pre-print. In this case, it is necessary not to make it difficult to see the latent image by the forgery prevention structure 10.

As shown in FIG. 1B, the forgery prevention structure 10 provided on the sheet base 2 is determined in advance among a plurality of recesses 11 formed in a matrix on the sheet base 2 and the plurality of recesses 11. A character mark 12 that is a first mark portion provided only in the recessed portion 11 and a background that is a second mark portion provided in the recessed portion 11 in which the character portion mark 12 is not provided among the plurality of recessed portions 11. It consists of a part mark 13. As shown in FIG. 1 (c), the recess 11 is recessed by about 0.1 mm from the plane portion 3 in the thickness direction of the sheet substrate 2, and the boundary portion with the plane portion 3 has a circular shape with a diameter of 0.5 mm or less. ing. As the distance from the boundary portion increases, the cross-sectional area gradually decreases. As shown in FIGS. 1D and 1E, the opposite side of the boundary portion is a bottom portion 11b parallel to the plane portion 3. For this reason, the inner surface 11 a of the recess 11 faces in an oblique direction with respect to the normal line of the flat surface portion 3. Character portion mark 12 by printing over the entire circumference in advance the depth from the plane portion 3 of the inner surface 11a of the determined recesses 11 is the first depth d ₁ position of the plurality of recesses 11 Since the boundary portion of the recess 11 with the flat portion 3 is circular, and the cross-sectional area of the recess 11 gradually decreases as the distance from the boundary portion increases, the plane of the sheet base 2 is reduced. It is circular when viewed from the normal direction of the part 3. Background section mark 13, the entire circumference at a position where the depth from the plane portion 3 of the inner surface 11a of the recess 11 of the character portion mark 12 is not provided is the second depth d ₂ of the plurality of recesses 11 Since the boundary portion between the concave portion 11 and the flat portion 3 is circular, and the cross-sectional area of the concave portion 11 gradually decreases as the distance from the boundary portion increases, the sheet When viewed from the normal direction of the flat surface portion 3 of the substrate 2, it is circular. Here, the depth d ₁ at which the character mark 12 is provided on the inner surface 11 a of the recess 11 and the depth d _{2 at} which the background mark 13 is provided are the depth at which the background mark 13 is provided. d ₂ is deeper than the depth d ₁ at which the character part mark 12 is provided. Note that the anti-counterfeit structure 10 illustrated in the present embodiment is formed with 10 recesses 11 in each of the vertical and horizontal directions for the sake of simplicity of explanation. A character that becomes a latent image that can be lifted by the prevention structure 10 can be made fine, and a curve or the like can be easily expressed.

  Below, the manufacturing method of the forgery prevention sheet 1 comprised as mentioned above is demonstrated.

  FIG. 2 is a diagram for explaining a manufacturing method of the forgery prevention sheet 1 shown in FIG. 1, and shows only a region of the sheet base material 2 where the forgery prevention structure 10 is provided.

  First, the character part mark 12 and the background part mark 13 are each printed in a circular shape in the region of the sheet base material 2 where the forgery prevention structure 10 is provided (FIG. 2A). The character part mark 12 is printed at a position where a “T” as a latent image is formed in a 10 × 10 matrix area where the recesses 11 are provided, and the background mark 13 is a 10 × 10 matrix area. Are printed at positions where the character part mark 12 is not printed. The character portion mark 12 and the background portion mark 13 are similar to each other, and the diameter thereof is as described above when the concave portion 11 is formed in the region where the character portion mark 12 and the background portion mark 13 are provided. The diameter of the character portion mark 12 is larger than the diameter of the background portion mark 13 so that the depth from the flat surface portion 3 is deeper than the character portion mark 12 in the background portion mark 13. The combination of the character mark 12 and the background mark 13 is set in advance according to the latent image (“T” in the present embodiment) that emerges from the forgery prevention structure 10 and is given as print data. The printing of the character mark 12 and the background mark 13 may be performed simultaneously with the pre-printing as described above, or may be performed after the pre-printing described above.

  Next, a plurality of recesses 11 are formed using an embossed plate in each of the area where the character part mark 12 is printed and the area where the background part mark 13 is printed (FIG. 2B). At this time, the concave portion 11 is formed so that the outer sides of the character portion mark 12 and the background portion mark 13 are the boundary portions with the plane portion 3, respectively, so that the character portion mark 12 and the background portion mark 13 are respectively recessed portions. 11 has a shape provided over the entire circumference of the inner surface 11a.

  As described above, the anti-counterfeit sheet 1 is manufactured, and then information corresponding to the application is printed on the information printing area 4 of the sheet base 2 and used. In addition, about formation of the recessed part 11 mentioned above, a transparent resin is apply | coated inside the character part mark 12 and the background part mark 13 of the sheet | seat base material 2 instead of using an embossed plate, and after this transparent resin hardens | cures, it is transparent. It is also conceivable to form the recess 11 by embedding a resin in the sheet base material 2.

  Below, the effect | action of the forgery prevention sheet 1 mentioned above is demonstrated.

  First, the operation when the anti-counterfeit sheet 1 shown in FIG. 1 is observed from the front, that is, from the normal direction of the flat portion 3 of the sheet base material 2 will be described.

  FIGS. 3A and 3B are diagrams for explaining the operation when the anti-counterfeit sheet 1 shown in FIG. 1 is observed from the front. FIG. 3A is a diagram viewed from the cross-sectional direction, and FIG. It is a figure which shows how the character part mark 12 and the background part mark 13 appear.

  When the anti-counterfeit sheet 1 shown in FIG. 1 is observed from the front, that is, from the normal direction of the plane portion 3 as shown in FIG. 3A, the character mark 12 provided in each of the plurality of recesses 11 and Since the background mark 13 is not obstructed from the observation direction, all the character mark 12 and the background mark 13 are visually recognized as shown in FIG.

  Although the character part mark 12 and the background part mark 13 are provided so that the depth from the plane part 3 is different from each other on the inner side surface 11a of the concave part 11, they are similar to each other and the anti-counterfeit sheet 1 When viewed from the front, it will be observed in the depth direction, whereby the character mark 12 and the background mark 13 are recognized as substantially the same shape, and the marks of the same shape are formed side by side. Is recognized as being. As the concave portion 11 is finer, these are more easily recognized as substantially the same shape.

  Next, an operation when the observation direction with respect to the anti-counterfeit sheet 1 shown in FIG. 1 is changed from the front direction, that is, the normal direction of the flat portion 3 of the sheet base material 2 will be described.

FIG. 4 is a diagram for explaining the operation when the observation direction for the forgery prevention sheet 1 shown in FIG. 1 is changed from the front, (a) is a view as seen from the cross-sectional direction, (b). Is a diagram showing an angle θ _{1 in the} observation direction with respect to the plane portion 3 when the background mark 13 becomes invisible, and (c) is a diagram showing a state in which the character mark 12 is viewed at the angle θ ₁ shown in (b). (D)-(g) is a figure which shows the appearance of the character part mark 12 and the background part mark 13 in the forgery prevention structure 10. FIG.

When the observation direction with respect to the forgery prevention sheet 1 shown in FIG. 1 is changed from the front, the angle formed by the observation direction with respect to the flat portion 3 of the sheet base 2 becomes an acute angle. And if the angle which the observation direction with respect to the plane part 3 of the sheet | seat base material 2 makes becomes smaller than angle (theta) _{1 as} shown in FIG.4 (b), the character part mark 12 provided in the inner surface 11a of the recessed part 11, and The background part mark 13 out of the background part mark 13 is hidden by the edge of the planar part 3 on the observation direction side of the recess 11 in which the background part mark 13 is provided. The angle θ _{1 at which} the background portion mark 13 is hidden by the edge of the flat surface portion 3 is set so that the background portion mark 13 and the recess portion 11 provided with the background portion mark 13 are, as shown in FIG. If the distance in the direction parallel to the plane part 3 between the edge of the plane part 3 on the observation direction side is w ₁ and the depth of the background mark 13 from the plane part 3 is t ₁ , the angle θ ₁ = It is represented by tan ⁻¹ (t ₁ / w ₁ ).

On the other hand, in the character part mark 12, even when the angle formed by the observation direction with respect to the flat part 3 of the sheet base material 2 becomes an angle θ ₁ at which the background part mark 13 cannot be seen, as shown in FIG. Furthermore, it is not hidden by the edge of the flat surface portion 3 on the observation direction side of the concave portion 11 provided with the character mark 12.

Therefore, when the observation direction with respect to the anti-counterfeit sheet 1 is changed to, for example, the lower side in FIG. 1 and the angle formed by the observation direction with respect to the flat portion 3 of the sheet substrate 2 is smaller than θ ₁ , the inner surface of the recess 11 is formed. Only the character portion mark 12 of the character portion mark 12 and the background portion mark 13 provided on 11a can be seen. As shown in FIG. 4D, the latent image “T” formed by the character portion mark 12 is displayed. "Emerges."

Here, in the anti-counterfeit sheet 1 shown in FIG. 1, the character part marks 12 constituting the latent image that emerges depending on the observation direction extend over the entire circumference of the inner side surface 11 a of the recess 11 formed on the sheet base 2. Therefore, as long as the angle formed between the plane part 3 of the sheet base material 2 and the observation direction is smaller than θ ₁ , the latent image by the character part mark 12 emerges from any direction. It looks up. For example, when the observation direction with respect to the anti-counterfeit sheet 1 is changed to the upper side in FIG. 1, the latent image “T” formed by the character mark 12 appears to appear as shown in FIG. When the observation direction with respect to the anti-counterfeit sheet 1 is changed to the right side in FIG. 1, the latent image “T” formed by the character mark 12 appears to appear as shown in FIG. When the observation direction with respect to the anti-counterfeit sheet 1 is changed to the left side in FIG. 1, the latent image “T” formed by the character mark 12 emerges as shown in FIG. It becomes visible.

If the angle formed by the flat surface portion 3 of the sheet base material 2 and the observation direction is smaller than θ _{1, the} background of the character portion mark 12 and the background portion mark 13 provided on the inner surface 11a of the concave portion 11 as described above. Although the part mark 13 is hidden and cannot be seen, the angle formed by the plane portion 3 of the sheet base material 2 and the observation direction is further reduced, and the angle formed by the observation direction with respect to the plane portion 3 of the sheet base material 2 is as shown in FIG. When the angle θ ₂ is smaller than the angle θ _{2 as} shown in (c), even the character part mark 12 provided on the inner surface 11a of the concave part 11 is the plane on the observation direction side of the concave part 11 provided with the character part mark 12. It is hidden by the edge of part 3 and cannot be seen. That is, when the angle θ formed by the observation direction with respect to the flat surface portion 3 of the sheet base material 2 is θ ₂ ≦ θ ≦ θ ₁ , the character portion mark 12 and the background portion mark 13 provided on the inner surface 11a of the concave portion 11. Among them, only the character part mark 12 becomes visible, so that the latent image “T” appears to appear. The angle θ _{2 at which} the character part mark 12 is hidden by the edge of the plane part 3 becomes invisible between the character part mark 12 and the concave part 11 provided with the character part mark 12 as shown in FIG. If the distance in the direction parallel to the plane portion 3 between the edge of the plane portion 3 on the observation direction side is w ₂ and the depth of the character mark 12 from the plane portion 3 is t ₂ , the angle θ ₂ = It is represented by tan ⁻¹ (t ₂ / w ₂ ).

  When the anti-counterfeit sheet 1 described above is copied, the information printed in the information printing area 4 of the sheet base material 2 and the character mark 12 and the background mark 13 provided by printing on the sheet base material 2 are copied. However, the concave portion 11 cannot be reproduced. For this reason, even if the observation direction of the copy is changed, the latent image by the character mark 12 does not appear, thereby making it possible to determine authenticity. Thus, when performing authenticity determination, in the anti-counterfeit sheet 1 of the present embodiment, when the observation direction with respect to the anti-counterfeit sheet 1 is changed from the normal direction of the flat portion 3 of the sheet base material 2 to which direction Even so, since the latent image by the character mark 12 appears to appear, it is possible to easily determine whether the latent image is true or false without being limited to the observation direction.

(Second Embodiment)
FIG. 5 is a diagram showing an anti-counterfeit sheet that is a second embodiment of the anti-counterfeit medium of the present invention, (a) is a diagram showing the overall configuration, and (b) is a forgery shown in (a). The figure which shows the detailed structure of the prevention structure 110, (c) is AA 'sectional drawing shown in (b), (d) is a figure which shows the structure of the recessed part 11 in which the character part mark 112 was provided, (e) ) Is a diagram showing the configuration of the recess 11 provided with the background mark 113.

  As shown in FIG. 5, the anti-counterfeit sheet 101 of this embodiment is different from that shown in the first embodiment in that the character mark 112 and the background mark 113 provided in the recess 11 are configured by broken lines. In addition, the background mark 113 is different from the inner surface 11a of the recess 11 in that it is provided on the bottom 11b. The background portion mark 113 is provided in a circular shape at the bottom portion 11b of the concave portion 11, and thereby has a similar shape to the character portion mark 112 provided over the entire circumference of the inner side surface 11a of the concave portion 11. . As described above, since the character mark 112 is provided on the inner surface 11a of the recess 11 and the background mark 113 is provided on the bottom 11b of the recess 11, the planar portion 3 of the background mark 113 is also provided in this embodiment. Is deeper than the depth from the flat portion 3 of the character mark 112.

  In the anti-counterfeit sheet 101 configured as described above, the character part mark 112 and the background part mark 113 are first printed on the sheet base material 2 in the same manner as shown in the first embodiment, and then The outside of the character part mark 112 and the background part mark 113 is the boundary part with the flat part 3, and the inside of the character part mark 112 and the outside of the background part mark 113 is the boundary between the inner side surface 11 a and the bottom part 11 b of the recess 11. The recess 11 is formed so as to be a part, whereby the character mark 112 is provided over the entire inner surface 11 a of the recess 11, and the background mark 111 is provided on the bottom 11 b of the recess 11. It becomes a shape.

  Below, the effect | action of the forgery prevention sheet 101 mentioned above is demonstrated.

  First, the operation when the anti-counterfeit sheet 101 shown in FIG. 5 is observed from the front, that is, from the normal direction of the flat portion 3 of the sheet substrate 2 will be described.

  6A and 6B are diagrams for explaining the operation when the anti-counterfeit sheet 101 shown in FIG. 5 is observed from the front. FIG. 6A is a diagram viewed from the cross-sectional direction, and FIG. It is a figure which shows how the character part mark 112 and the background part mark 113 are seen.

  When the anti-counterfeit sheet 101 shown in FIG. 5 is observed from the front, that is, from the normal direction of the plane portion 3 as shown in FIG. 6A, the character mark 112 provided in each of the plurality of recesses 11 and Since the background portion mark 113 is not obstructed from the observation direction, all the character portion marks 112 and the background portion marks 113 are visually recognized as shown in FIG.

  The character portion mark 112 and the background portion mark 113 are provided in the recess 11 so that the depths from the plane portion 3 are different from each other, but are similar to each other, and the forgery prevention sheet 101 is observed from the front. In this case, the character portion mark 112 and the background portion mark 113 are recognized as substantially the same shape and are recognized as being formed side by side. Is done. In FIG. 6B, the character mark 112 and the background mark 113 are shown in a shape that can be distinguished in order to clarify the configuration in the recess 11, but in actuality, the recess 11 Since these are fine, they are recognized as substantially the same shape.

  Next, an operation when the observation direction with respect to the anti-counterfeit sheet 101 shown in FIG. 5 is changed from the front, that is, the normal direction of the flat portion 3 of the sheet base material 2 will be described.

FIG. 7 is a diagram for explaining the operation when the observation direction with respect to the anti-counterfeit sheet 101 shown in FIG. 5 is changed from the front, (a) is a view as seen from the cross-sectional direction, and (b). Is a diagram showing an angle θ _{1 in the} observation direction with respect to the flat surface portion 3 when the background mark 113 becomes invisible, and (c) is a diagram showing a state in which the character mark 112 is viewed at the angle θ ₁ shown in (b). (D)-(g) is a figure which shows the appearance of the character part mark 112 and the background part mark 113 in the forgery prevention structure 110. FIG.

If the observation direction with respect to the anti-counterfeit sheet 101 shown in FIG. 5 is changed from the front, the angle formed by the observation direction with respect to the flat portion 3 of the sheet substrate 2 becomes an acute angle. When the angle formed by the observation direction with respect to the flat surface portion 3 of the sheet substrate 2 is smaller than the angle θ _{1 as} shown in FIG. 7B, the character mark 112 provided on the inner surface 11a of the recess 11 In addition, among the background portion marks 113 provided on the bottom portion 11 b of the recess 11, the background portion mark 113 is hidden by the edge of the planar portion 3 on the observation direction side of the recess portion 11 where the background portion mark 113 is provided. Note that the angle θ _{1 at which} the background mark 113 is hidden by the edge of the flat surface 3 is invisible, as shown in FIG. 7B, between the background mark 113 and the recess 11 in which the background mark 113 is provided. If the distance in the direction parallel to the plane portion 3 between the edge of the plane portion 3 on the observation direction side is w ₁ and the depth of the recess 11 from the plane portion 3 is t ₁ , the angle θ ₁ = tan ^{− 1} (t ₁ / w ₁ ).

On the other hand, in the character part mark 112, even when the angle formed by the observation direction with respect to the flat part 3 of the sheet base material 2 becomes an angle θ ₁ at which the background part mark 113 becomes invisible, as shown in FIG. Furthermore, it is not hidden by the edge of the flat surface portion 3 on the observation direction side of the concave portion 11 in which the character portion mark 112 is provided.

Therefore, the observation direction with respect to the anti-counterfeit sheet 101 is changed to, for example, the lower side in FIG. 5, and when the angle formed by the observation direction with respect to the flat portion 3 of the sheet base 2 is smaller than θ ₁ , the inner surface of the recess 11. Of the character part mark 112 provided on 11a and the background part mark 113 provided on the bottom part 11b of the recess 11, only the character part mark 112 can be seen. As shown in FIG. The latent image “T” formed by the part mark 112 appears to appear.

Here, in the anti-counterfeit sheet 101 shown in FIG. 5, the character mark 112 constituting the latent image that emerges depending on the observation direction extends over the entire circumference of the inner surface 11 a of the recess 11 formed on the sheet base 2. Therefore, if the angle formed between the flat surface portion 3 of the sheet base material 2 and the observation direction is smaller than θ ₁ , the latent image by the character portion mark 112 emerges from any direction. It looks up. For example, when the observation direction with respect to the anti-counterfeit sheet 101 is changed to the upper side in FIG. 5, the latent image “T” constituted by the character mark 112 appears to appear as shown in FIG. When the observation direction with respect to the forgery prevention sheet 101 is changed to the right side in FIG. 5, the latent image “T” constituted by the character mark 112 appears to appear as shown in FIG. When the observation direction with respect to the anti-counterfeit sheet 101 is changed to the left side in FIG. 5, the latent image “T” formed by the character mark 112 emerges as shown in FIG. It becomes visible.

If the angle formed by the flat surface portion 3 of the sheet base material 2 and the observation direction is smaller than θ _1, the character mark 112 provided on the inner surface 11 a of the recess 11 and the bottom 11 b of the recess 11 are formed as described above. Among the provided background portion marks 113, the background portion marks 113 are hidden and cannot be seen, but the angle formed by the plane portion 3 of the sheet base material 2 and the observation direction is further reduced, and the plane portion of the sheet base material 2 is reduced. When the angle formed by the observation direction with respect to 3 is smaller than the angle θ _{2 as} shown in FIG. 7C, even the character mark 112 provided on the inner surface 11a of the recess 11 is It is hidden by the edge of the flat surface portion 3 on the observation direction side of the provided concave portion 11 and becomes invisible. That is, when the angle θ formed by the observation direction with respect to the flat surface portion 3 of the sheet base material 2 is θ ₂ ≦ θ ≦ θ ₁ , the character mark 112 provided on the inner surface 11a of the recess 11 and the recess 11 Of the background portion marks 113 provided on the bottom portion 11b, only the character portion marks 112 are visible, so that the latent image “T” appears to emerge. The angle θ _{2 at which} the character part mark 112 is hidden by the edge of the plane part 3 becomes invisible between the character part mark 112 and the concave part 11 provided with the character part mark 112 as shown in FIG. When the distance in the direction parallel to the plane portion 3 between the edge of the plane portion 3 on the observation direction side is w ₂ and the depth of the character mark 112 from the plane portion 3 is t ₂ , the angle θ ₂ = It is represented by tan ⁻¹ (t ₂ / w ₂ ).

  When the anti-counterfeit sheet 101 described above is copied, the information printed in the information printing area 4 of the sheet base 2 and the character mark 112 and the background mark 113 provided by printing on the sheet base 2 are copied. However, the concave portion 11 cannot be reproduced. For this reason, even if the observation direction of the copy is changed, the latent image formed by the character mark 112 does not appear, thereby making it possible to determine authenticity. Thus, when performing authenticity determination, in the anti-counterfeit sheet 101 of this embodiment, when the observation direction with respect to the anti-counterfeit sheet 101 is changed from the normal direction of the flat portion 3 of the sheet base material 2 to which direction Even so, since the latent image by the character mark 112 appears to emerge, it is possible to easily determine whether the latent image is true or false without being limited to the observation direction.

  In the two embodiments described above, the character portion marks 12 and 112 and the background portion marks 13 and 113 provided on the anti-counterfeit structures 10 and 110 are not uniform in width as in the present embodiment, but a part thereof. The shape which protruded in the width direction may be sufficient.

  Moreover, about the depth from the plane part 3 of the recessed part 11 in the two embodiment mentioned above, and the dimension of the boundary part with the plane part 3, not only what was mentioned above but can be set suitably.

  Further, the concave portion 11 may be a cylindrical shape, a conical shape without the bottom portion 11b, or a dome shape. It is also conceivable that the cross section is rectangular. However, the distance from the center is substantially constant such that the boundary portion of the concave portion 11 with the flat portion 3 is circular, and accordingly, the character mark 12, 112 is also the distance from the center as circular. Is substantially constant, the shape of the character mark 12, 112 that can be viewed from any direction is the same, and the detailed shape of the latent image that emerges from the character mark 12, 112 is improved. It can be made uniform.

  In the above-described two embodiments, the depth of the background marks 13 and 113 in the recess 11 is deeper than the depth of the character marks 12 and 112. It is also conceivable that the depth of 112 is made deeper than the depth of the background marks 13 and 113 so that the latent image emerges as white characters.

  Further, the information to be a latent image is not limited to information consisting of a single character like “T” described above, but may be information consisting of a plurality of characters, a pattern, or the like. It is also conceivable to divide the plurality of recesses 11 into a plurality of areas and to have a structure in which characters and the like are raised in each of the plurality of areas.

  In addition, the similar shape referred to in the present application is not only a general shape similar shape but also a circular shape with a part of the circumference cut off or a part of the circumference slightly distorted. Also, a shape that is slightly elliptical or slightly distorted to a shape that approaches a triangle or a rectangle is defined as a similar shape.

  In the two embodiments described above, the forgery prevention sheet 1, 101 provided with the anti-counterfeit structures 10, 110 on the sheet base material 2 made of paper has been described as an example of the forgery prevention medium. The present invention is not limited to such anti-counterfeit sheets 1, 101, but is provided with the above-described anti-counterfeit structures 10, 110 on a sheet base material made of a film or a card base material on which a plurality of resin layers are laminated. It is also possible to apply to.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the forgery prevention sheet | seat used as 1st Embodiment of the forgery prevention medium of this invention, (a) is a figure which shows the whole structure, (b) is the detail of the forgery prevention structure shown to (a). (C) is a cross-sectional view taken along the line AA ′ shown in (b), (d) is a diagram showing a configuration of a recess provided with a character mark, and (e) is provided with a background mark. It is a figure which shows the structure of the formed recessed part. It is a figure for demonstrating the manufacturing method of the forgery prevention sheet | seat shown in FIG. It is a figure for demonstrating the effect | action at the time of observing the anti-counterfeit sheet | seat shown in FIG. 1 from the front, (a) is the figure seen from the cross-sectional direction, (b) is a character part mark and background part in a forgery prevention structure. It is a figure which shows how a mark looks. It is a figure for demonstrating an effect | action at the time of changing the observation direction with respect to the forgery prevention sheet shown in FIG. 1 from the front, (a) is the figure seen from the cross-sectional direction, (b) is a background part mark. The figure which shows the angle of the observation direction with respect to a plane part when it disappears, (c) is the figure which shows the state which looked at the character part mark at the angle shown in (b), (d)-(g) is a forgery prevention structure It is a figure which shows how the character part mark and background part mark in FIG. It is a figure which shows the forgery prevention sheet | seat used as 2nd Embodiment of the forgery prevention medium of this invention, (a) is a figure which shows the whole structure, (b) is the detail of the forgery prevention structure shown to (a). (C) is a cross-sectional view taken along the line AA ′ shown in (b), (d) is a diagram showing a configuration of a recess provided with a character mark, and (e) is provided with a background mark. It is a figure which shows the structure of the formed recessed part. It is a figure for demonstrating the effect | action at the time of observing the anti-counterfeit sheet | seat shown in FIG. 5 from the front, (a) is the figure seen from the cross-sectional direction, (b) is a character part mark and background part in a forgery prevention structure. It is a figure which shows how a mark looks. It is a figure for demonstrating an effect | action at the time of changing the observation direction with respect to the forgery prevention sheet shown in FIG. 5 from the front, (a) is the figure seen from the cross-sectional direction, (b) is a background part mark. The figure which shows the angle of the observation direction with respect to a plane part when it disappears, (c) is the figure which shows the state which looked at the character part mark at the angle shown in (b), (d)-(g) is a forgery prevention structure It is a figure which shows how the character part mark and background part mark in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Anti-counterfeit sheet | seat 2 Sheet | seat base material 3 Flat part 4 Information printing area | region 10,110 Anti-counterfeit structure 11 Recessed part 11a Inner side surface 11b Bottom part 12,112 Character part mark 13,113 Background part mark

Claims (1)

A plurality of recesses formed to be recessed from the substrate surface;
A first mark portion provided at a position that is a first depth from the surface of the base material of a predetermined recess among the plurality of recesses;
A position that is similar to the first mark portion and has a second depth different from the first depth from the surface of the base material of the concave portion in which the first mark portion is not provided among the plurality of concave portions. And a second mark portion provided in the
Each of the plurality of recesses has its inner surface facing an oblique direction with respect to the normal of the substrate surface so that its cross-sectional area becomes narrower as it moves away from the boundary portion with the substrate surface. And
At least one of the first mark portion and the second mark portion is a forgery prevention medium provided over the entire circumference of the inner surface of the recess.

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