JP2012198371A - Diffraction grating recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display body including a concealed pattern using an optical diffraction structure, which is very difficult to be visually determined and has outstanding anti-counterfeit effect, a determining tool therefor, and a display body determination system.SOLUTION: A concealed pattern region is filled with repetition of stripe pairs of first wavy stripes 121a and second wavy stripes 121b different by diffraction characteristics, and the inside of each of the first wavy stripes 121a is constituted of a first linear diffraction grating 12'1a, and the inside of each of the second wavy stripes 121b is constituted of a second linear diffraction grating 12'1b. Tilt angles of the first linear diffraction gratings 12'1a and tilt angles of the second linear diffraction gratings 12'1b in a first pattern region constituting a concealed pattern are equal to tilt angles of the first linear diffraction gratings 12'1a and tilt angles of the second linear diffraction gratings 12'1b in a second pattern region adjacent to the first pattern region respectively with respect to a reference line S set to a display surface, and characteristics of stripe pairs in the first pattern region are different from those of stripe pairs in the second pattern region.

Description

  The present invention relates to a display body including a hidden pattern by a light diffractive structure, a discrimination tool therefor, and a display body discrimination system, and more particularly, a display body including a hidden pattern by a light diffractive structure that is difficult to discriminate in a normal viewing state. And a discriminating tool therefor, and a display body discriminating system.

  In recent years, forgery cases of high-value banknotes and gift certificates using color copiers have frequently occurred. For this reason, high-value banknotes and gift certificates have a small halftone dot or fine line that cannot be read by a color copier sensor in a part of the design, and is incorporated in a pattern designed with the same reflection density. As a result, when trying to copy these high-value banknotes and gift certificates with a color copier, the copier scanner reads out small dots and fine lines, and those parts are identified as white and are identified as copies. .

  In addition, a method of discriminating a copy product by providing a brilliant metal part in a part of the design of the printed material is also implemented.

  Since such a metal part reflects 100% of incident light, the copying machine copies the metal part to black. As an example, for example, a gold thread is sewed on the surface layer of paper, and copy check is performed.

  In addition, the metal diffractive surface of the light diffraction structure replicated with a transparent resin is subjected to metal vapor deposition, thermally transferred to a part of the printing area, and the copying by the copying machine is restrained. This light diffractive structure is used as a means for preventing counterfeiting of a printed matter or product itself that has been thermally transferred, while trying to check fraud due to copying by the reflection effect of the metal surface. The light diffractive structure is often used as a forgery prevention means such as a cash voucher because it requires an advanced manufacturing technique.

  However, improvement in manufacturing technology has made it possible to manufacture an optical diffraction structure that is close to the real thing at first glance.

  In order to check such counterfeit products, a technique has been proposed in which a hidden pattern that is difficult to discriminate is incorporated into a light diffraction structure and used as a means of authenticity discrimination. There is a problem that it is discriminated, and since there is no other pattern formed in the part where the hidden pattern is formed, it is assumed that there is a hidden pattern, and there is a problem of reducing the forgery prevention effect there were.

  In such a background, the normal display pattern can be observed in the visual state due to the difference in the configuration of each region of the linear diffraction grating, and it is difficult to distinguish the hidden pattern. There has been disclosed a display body that includes a hidden pattern based on an optical diffraction structure in which a hidden pattern can be distinguished instead of a display pattern (see Patent Documents 1 and 2).

The invention of Patent Document 1
・ Give multiple patterns in the light diffraction structure,
・ Each pattern is formed by parallel stripes adjacent to each other,
-The diffraction grating pitch or inclination angle of the adjacent first stripe and the second stripe is different,
-By making the inclination angles of each pair of stripes constituting each pattern different, a hidden pattern coexists in the light diffraction structure (diffraction grating),
-A hidden pattern is discriminated by discriminating with a discriminating instrument consisting of a transparent portion and an opaque portion having the same pitch as each stripe pair.

The invention of Patent Document 2
・ Give multiple patterns in the light diffraction structure of the display,
・ Each pattern is formed by parallel stripes adjacent to each other,
-The diffraction grating pitch or inclination angle of the adjacent first stripe and the second stripe is different,
-By making the inclination angle of each stripe pair constituting each pattern the same and making the pitch different, the hidden pattern coexists in the optical diffraction structure (diffraction grating),
A hidden pattern is discriminated by discriminating it with a discriminator consisting of a transparent portion and an opaque portion having the same pitch and the same inclination angle as the pitch of each stripe pair.

Japanese Patent Laid-Open No. 2004-212927 JP 2005-266041 A

  However, in the conventional technique, when the display body and the discriminator are overlapped to discriminate the hidden pattern, the stripe of the display body and the transparent part and the opaque part of the discriminator are straight lines, so that moiré is generated to the maximum. For this reason, it is difficult to superimpose the straight lines of the stripes of the display body and the straight lines of the transparent part and the opaque part of the discriminating tool so that there is no deviation. For this reason, the contrast of the moire pattern is lowered, and the visibility of characters generated from the moire may be reduced.

  The present invention has been made in view of such a current state of the prior art, and an object of the present invention is to clearly display a hidden pattern moire pattern by an optical diffraction structure that is extremely difficult to visually discriminate and has a large anti-counterfeit effect. To provide a body, a discriminating tool therefor, and a display body discriminating system.

  The display body including the hidden pattern by the light diffraction structure of the present invention that achieves the above object includes a display surface having a light diffraction structure, the display surface has different diffraction characteristics, and has an arbitrary outer shape according to the display pattern and A plurality of pattern areas having an inner shape are arranged in parallel, and the plurality of pattern areas have a hidden pattern area and a non-hidden pattern area, and the hidden pattern area is embedded at a predetermined repetition pitch. The hidden pattern area includes a pair of stripes, and the hidden pattern area stripe pairs are adjacent to each other in parallel and have different diffraction characteristics. The first wavy stripes of the hidden pattern area and the second wavy stripes of the hidden pattern area And the first wavy stripe in the hidden pattern region is configured by a first linear diffraction grating in the hidden pattern region in the wavy stripe, The second wavy stripe is formed by a second linear diffraction grating in the hidden pattern area in a wavy stripe, and the non-hidden pattern area is a stripe of the non-hidden pattern area embedded at a predetermined repetition pitch. The first wavy stripe in the non-hidden pattern region is formed by a first linear diffraction grating in the non-hidden pattern region, and the second wavy stripe in the non-hidden pattern region is The slope of the first linear diffraction grating in the hidden pattern region is defined by the second linear diffraction grating in the non-hidden pattern region and the reference line set with respect to the display surface. An angle is equal to an inclination angle of the first linear diffraction grating in the non-hidden pattern region, and an inclination angle of the second linear diffraction grating in the non-hidden pattern region is equal to the second straight angle of the non-hidden pattern region. Equal to the tilt angle of the diffraction grating, and the characteristics of the stripe pair of the hidden pattern area, the different it is preferred characteristics of the stripe pair of non-hidden pattern region.

  The first wavy stripes in the hidden pattern area and the second wavy stripes in the hidden pattern area, and the first wavy stripes in the non-hidden pattern area and the second wavy stripes in the non-hidden pattern area are , It is preferable to have convex portions and concave portions having a height of 5 to 20% alternately with respect to each repeating pitch.

  The first wavy stripes in the hidden pattern area and the second wavy stripes in the hidden pattern area, and the first wavy stripes in the non-hidden pattern area and the second wavy stripes in the non-hidden pattern area are It is preferable that convex portions and concave portions of 0.5 to 5 pieces / mm are alternately provided for each repetition pitch.

  In addition, it is preferable that an inclination angle of the stripe pair in the hidden pattern area is different from an inclination angle of the stripe pair in the non-hidden pattern area with respect to a reference line set for the display surface.

  The repetitive pitch of the stripe pairs in the hidden pattern area is preferably different from the repetitive pitch of the stripe pairs in the non-hidden pattern area.

  Further, the discriminating tool for the display body including the hidden pattern by the light diffraction structure has a parallel inclination having the same inclination angle as the stripe pair in the hidden pattern area and the same repetition pitch as the stripe pair in the hidden pattern area. It is preferable to have a repeating pattern of straight transparent portions and straight opaque portions.

  Further, the discriminating tool for the display body including the hidden pattern by the light diffraction structure has a parallel inclination having the same inclination angle as the stripe pair in the hidden pattern area and the same repetition pitch as the stripe pair in the hidden pattern area. It is preferable to have a repeating pattern of a wavy transparent part and a wavy opaque part.

  The width of the transparent part is preferably smaller than the width of the opaque part.

Further, the display body discriminating system including the hidden pattern by the light diffractive structure includes a display surface having the light diffractive structure, and the display surface has different diffraction characteristics and has an arbitrary outer shape and inner shape according to the display pattern. A plurality of pattern areas having a plurality of pattern areas, the plurality of pattern areas having a hidden pattern area and a non-hidden pattern area, wherein the hidden pattern area is embedded at a predetermined repetition pitch. The hidden pattern region stripe pair has a first wavy stripe of the hidden pattern region and a second wavy stripe of the hidden pattern region that are adjacent to each other and parallel and have different diffraction characteristics, The first wavy stripe in the hidden pattern area is formed by a first linear diffraction grating in the hidden pattern area in a wavy stripe, and the front of the hidden pattern area is The second wavy stripe is formed by the second linear diffraction grating of the hidden pattern area in the wavy stripe, and the non-hidden pattern area is a pair of stripes of the non-hidden pattern area embedded at a predetermined repetition pitch. The first wavy stripe in the non-hidden pattern region is configured by a first linear diffraction grating in the non-hidden pattern region in a wavy stripe, and the second wavy stripe in the non-hidden pattern region is An inclination angle of the first linear diffraction grating in the hidden pattern region with respect to a reference line set with respect to the display surface is formed by a second linear diffraction grating in the non-hidden pattern region in a wavy stripe Is equal to the tilt angle of the first linear diffraction grating in the non-hidden pattern region, and the tilt angle of the second linear diffraction grating in the non-hidden pattern region is equal to the tilt angle of the second linear diffraction grating in the non-hidden pattern region. A display body including a hidden pattern having a light diffraction structure equal to a tilt angle of the grating and having a characteristic of the fringe pair in the hidden pattern region different from that of the stripe pair in the non-hidden pattern region; It is preferable to include a discriminator having a repeating pattern of parallel wavy transparent portions and wavy opaque portions having the same inclination angle as the stripe pairs in the pattern region and the same repetition pitch as the stripe pairs in the hidden pattern region.

  In the present invention, the display surface of the display body including the light diffractive structure is parallel to each other, the first fringe pair of the first fringe and the second fringe having different diffraction characteristics, and the straight lines constituting the fringes. It is composed of a double structure with the diffraction grating, and the structure of the linear diffraction grating is the same in the region constituting the hidden pattern and the other regions, and the configuration of the stripe pair is different, so that the linear diffraction grating is visually observed. The normal display pattern can be observed due to the difference in the configuration of each region, and the hidden pattern is difficult to discriminate, but this time instead of the normal display pattern by overlapping the above stripe pair and the discriminator that causes the moire phenomenon A hidden pattern can be discriminated. Then, at least one of the first stripe and the second stripe, or the transparent stripe and the opaque stripe of the discriminator is used as a wavy stripe. Therefore, it includes a hidden pattern that is extremely difficult to visually discriminate, has a large anti-counterfeiting effect, and can provide a display with high design.When a discriminator is superimposed on the hidden pattern of the display, A high clear moire pattern can be generated, and the authenticity of the display body can be easily confirmed.

It is a figure for demonstrating an example of the printed matter which transferred the light diffraction structure which has a hidden pattern by this embodiment. It is a figure for demonstrating the basic composition of the display unit area | region which has the uniform characteristic and structure in a partial display surface in this embodiment. It is an enlarged view which shows the stripe pair of this embodiment. It is an enlarged view of the partial display surface containing the hidden pattern by the light diffraction structure of 1st Embodiment. FIG. 5 is an enlarged view of a portion A surrounded by a broken line in FIG. 4. It is a top view of an example of the discrimination tool for discriminating the hidden pattern of the partial display surface of FIG. It is a figure which shows the state which accumulated the discrimination tool on the partial display surface of FIG. It is a figure which shows the hidden pattern discriminated from the partial display surface of FIG. It is an enlarged view of the partial display surface 2 including the hidden pattern by the light diffraction structure of 2nd Embodiment. FIG. 10 is an enlarged view of a portion B surrounded by a broken line in FIG. 9. It is a top view of an example of the discriminating tool for discriminating the hidden pattern of the partial display surface of FIG. FIG. 10 is a diagram showing a state in which a discriminator is overlaid on the partial display surface of FIG. 9. It is a figure which shows the hidden pattern discriminated from the partial display surface of FIG. It is an enlarged view of the partial display surface 2 including the hidden pattern by the light diffraction structure of 3rd Embodiment. FIG. 15 is an enlarged view of a portion C surrounded by a broken line in FIG. 14. It is the figure which looked at the partial display surface by visual observation. It is an enlarged view of the partial display surface 2 including the hidden pattern by the optical diffraction structure of 4th Example carrying. It is a figure which shows the state which discriminate | determined the hidden character "H" from the partial display surface. It is a figure which shows the state which discriminate | determined the hidden character "T" from the partial display surface. It is a top view of an example of the discrimination tool for discriminating the hidden pattern of the partial display surface of FIG. It is a figure which shows the state which discriminate | determined the hidden characters "H" and "T" from the partial display surface. It is a figure for demonstrating the border provided in the periphery of each pattern. It is a figure for demonstrating the width | variety relationship of the discrimination | determination pattern which consists of a repeating pattern of a parallel linear transparent part and a linear opaque part. It is a figure which shows the discrimination tool of other embodiment. It is a figure which shows the wavy transparent part and wavy opaque part of a discrimination tool. It is sectional drawing which shows the layer structure in the case of comprising as a transfer foil the display body which includes the hidden pattern by an optical diffraction structure. It is sectional drawing which shows the layer structure in the case of comprising as a label the display body which includes the hidden pattern by a light diffraction structure. It is sectional drawing which shows the layer structure in the case of comprising the display body which includes the hidden pattern by a light diffraction structure as a brittle label. It is sectional drawing which shows the layer structure in the case of comprising as a film the display body which includes the hidden pattern by a light diffraction structure.

  Hereinafter, a hidden pattern and a discriminator therefor according to the light diffraction structure of the present invention will be described with reference to the drawings.

  FIG. 1 is a view for explaining an example of a printed material to which a light diffraction structure having a hidden pattern according to the present invention is transferred as one embodiment of the present invention. A display body 1 including a hidden pattern for checking forgery or copying is formed at a predetermined position of the printed matter 4. In this case, the display body 1 is formed on a printed matter 4 such as paper as a label with a heat-reactive adhesive after an extremely thin resin with unevenness is melted to a predetermined size by heat.

  Alternatively, it is punched into a predetermined size in a state where the light diffraction structure is formed on the base film, and is formed on the printed matter 4 together with the base film by an adhesive or an adhesive.

  Many printed materials on which such a display body 1 is formed are difficult to be counterfeited or copied, for example, banknotes, gift certificates, admission tickets, gift certificates, bills, checks, and the like. In addition, the printing itself incorporates a technique that cannot be duplicated without a special technique, and is double protected against forgery and misuse by copying.

  The display surface 1 is composed of a partial display surface 2 including a hidden pattern and another partial display surface 3. Even if both the partial display surface 2 and the partial display surface 3 are display surfaces having a light diffraction structure, the hidden pattern is displayed. Only the partial display surface 2 including the light diffraction structure may be a display surface, and the other partial display surface 3 may be a display surface not based on the light diffraction structure such as printing. Of course, the display surface 3 may consist only of the partial display surface 2 including the hidden pattern by the light diffraction structure.

  FIG. 2 is a diagram for explaining the basic configuration of the display unit area having uniform characteristics and configuration in the partial display surface in the present embodiment.

As shown in FIG. 2, on the partial display surface 2, display unit regions 5 having uniform characteristics and configuration are gathered in parallel. The display unit region 5 constitute any contour and inner shape pattern area corresponding to the display pattern, the pattern region is parallel to and adjacent to each other, the first wavy fringe ₆₁ having different diffractive properties first is filled by two repetitions of wavy stripes 6 ₂ stripes pairs 6 becomes, the first wavy fringe ₆₁ is constituted by a first linear diffraction grating 6 _'1, the second wavy stripes 6 ₂ second linear diffraction grating 6 'Consists of _two .

Here, the inclination angle of the first wavy stripe 6 ₁ and the second wavy stripe 6 ₂ with respect to the reference line S is α, the inclination angle of the first linear diffraction grating 6 ′ ₁ with respect to the reference line S is β ₁ , and the second linear diffraction grating. An inclination angle with respect to the reference line S of 6 ′ ₂ is β ₂ . As the reference line S, for example, a straight line parallel to the direction recognized as horizontal with respect to the display pattern of the partial display surface 2, for example, the long side direction of the display surface 2 is used. Note that the inclination angles β ₁ and β ₂ of the diffraction gratings 6 ′ ₁ and 6 ′ ₂ are angles with respect to the reference line S of the grating lines.

  FIG. 3 is an enlarged view showing the stripe pair 6 of the present embodiment.

The fringe pair 6 has a first wavy stripe 6 ₁ and a second wavy stripe 6 ₂ . If the repetition pitch of the first wavy stripe 6 ₁ is d ₁ and the repetition pitch of the second wavy stripe 6 ₂ is d ₂ , the repetition pitch of the stripe pair 6 is d = d ₁ + d ₂ . Here, the repetition pitch d of the stripe pair 6 is preferably set to d ≦ 1/5 mm.

The first wavy fringe ₆₁ forms a waveform having alternating projections and recesses of the height h against repeated pitch d _1. Similarly, the second wavy stripe 6 ₂ forms a waveform by alternately having concave portions with convex portions having a height h with respect to the repetition pitch d ₂ . The number of irregularities is preferably 0.5 to 5 / mm. The height h of unevenness, 5-20% of the repetition pitch d ₂ of the first wavy stripes 6 ₁ repetition pitch d ₁ and the second wavy stripes 6 ₂ is preferred.

As shown in FIG. 2, the first linear diffraction grating 6 ′ ₁ and the second linear diffraction grating 6 ′ ₂ have different inclination angles (β ₁ ≠ β ₂ ), or whether the grating pitches of the diffraction gratings are different. It is chosen to satisfy at least one. Of course, the grating pitch of the first linear diffraction grating 6 ′ ₁ and the second linear diffraction grating 6 ′ ₂ is set sufficiently smaller than the repetition pitch d of the stripe pair 6. Usually, the grating pitch of the diffraction gratings 6 ′ ₁ and 6 ′ ₂ is in the range of 0.5 μm to ₂ μm. Moreover, the difference in inclination angle | β ₁ −β ₂ | between the first linear diffraction grating 6 ′ ₁ and the second linear diffraction grating 6 ′ ₂ is not limited, but is set in a range of 30 ° to 90 °. Is desirable.

As described above, the display unit region 5 formed by arranging the partial display surfaces 2 including the hidden pattern by the light diffraction structure of the present invention in parallel includes the linear diffraction gratings 6 ′ ₁ and 6 ′ ₂ and their linear diffraction gratings. The first wavy stripe 6 ₁ and the second wavy stripe 6 ₂ constituted by a pair of stripes 6 have a double structure, and the double structure is characteristic.

In the following description, the first linear diffraction grating 6 _'1, second linear diffraction grating 6' _2, especially when not needed, either be omitted linear terms, the first diffraction grating 6 _'1, the It referred to as a second diffraction grating 6 _'2.

  FIG. 4 is an enlarged view of the partial display surface 2 including a hidden pattern by the light diffraction structure of the first embodiment.

  As shown in FIG. 4, on the partial display surface 2, the display pattern includes a first area 11 excluding a portion of the character “H” in the center of the background and a second of the character “H” in the center. Region 12. Here, the letter “H” is configured as a hidden pattern.

  FIG. 5 is an enlarged view of a portion A surrounded by a broken line in FIG.

The inclination angle α ₁₁ of the first wavy stripe 11 _1a and the second wavy stripe 11 _1b (first stripe pair 11 ₁ ) constituting the non-hidden pattern region 11 is selected to be 45 °, for example. In addition, the inclination angle α ₁₂ of the first wavy stripe 12 _1a and the second wavy stripe 12 _1b (second stripe pair 12 ₁ ) constituting the hidden pattern region 12 is selected to be, for example, 135 °. In the first embodiment, the repetition pitch d ₁₁ of the stripe pair 11 ₁ of the non-hidden pattern region ₁₁ and the repetition pitch d ₁₂ of the stripe pair 12 ₁ of the hidden pattern region 11 are set equal.

The first diffraction grating 11 ′ _1a of the first wavy stripe 11 _1a in the non-hidden pattern region 11 is selected at an inclination angle β _11a = 0 °. In addition, the second diffraction grating 11 ′ _1b of the second wavy stripe 11 _1b in the non-hidden pattern region 11 is selected at an inclination angle β _11b = 45 °.

The first diffraction grating 12 ′ _1a of the first wavy stripe 12 _1a in the hidden pattern region 12 is selected at an inclination angle β _12a = 0 °. In addition, the second diffraction grating 12 ′ _1b of the second wavy stripe 12 _1b in the hidden pattern region 12 is selected at an inclination angle β _12b = 45 °.

That is, on the display surface 2 of the first embodiment, the first diffraction grating 11 ′ _1a of the non-hidden pattern region 11 having the inclination angle β _11a = 0 °, the first diffraction grating 12 ′ _1a of the hidden pattern region 12, and the second diffraction grating 11 _'1b and the second diffraction grating 12 of the hidden pattern region 12' _1b of the non-hidden pattern region 11 of the tilt angle β _11b = 45 °, respectively comprise substantially the same rate.

Further, the tilt angle alpha ₁₂ stripe pair 12 ₁ of the pattern regions 12 and hidden stripe pair 11 ₁ of the inclination angle alpha ₁₁ of the non-hidden pattern area 11 of the first embodiment is different. Moreover, the repetition pitch d ₁₁ and repetition pitch d ₁₂ of stripe pair 12 ₁ of the hidden pattern area 12 of the stripe pair 11 ₁ of the non-hidden pattern region 11 are equal is set to satisfy d _11, d ₁₂ ≦ one / 5 mm The Incidentally, the repetition pitch d ₁₂ repetition pitch d ₁₁ and stripe pair 12 ₁ of the stripe pair 11 ₁ may be different.

The inclination angle β _11a of the first diffraction grating 11 ′ _{1a in} the non-hidden pattern area 11 and the inclination angle β _12a of the first diffraction grating 12 ′ _{1a in} the hidden pattern area ₁₂ are 0 °, and the second angle of the non-hidden pattern area 11 is 2nd. Since the inclination angle β _11b of the diffraction grating 11 ′ _1b and the inclination angle β _12b of the second diffraction grating 12 ′ _{1b in} the hidden pattern region 12 are 45 ° in common, they cannot be distinguished from each other in a normal visual state.

  Therefore, in a normal visual state without using a discriminator described later, the entire display surface 2 is observed in a state where there is no display pattern with uniform brightness, and the hidden character “H” cannot be discriminated.

  FIG. 6 is a plan view of an example of a discriminator for discriminating a hidden pattern on the partial display surface of FIG.

The discriminator 20 is a repeating pattern of parallel straight transparent portions 20a and straight opaque portions 20b, and the repeating pitch has a pitch d ₂₀ equal to the repeating pitch d ₁₂ of the stripe pair 12 _{1 on} the display surface 2, The inclination angle α ₂₀ with respect to the reference line S of the straight transparent portion 20 a and the straight opaque portion 20 b has the same 135 ° as the inclination angle α ₁₂ of the stripe pair 12 ₁ of the hidden pattern region 12.

  7 is a diagram showing a state in which the discriminating tool is superimposed on the partial display surface of FIG. 4, and FIG. 8 is a diagram showing a hidden pattern discriminated from the partial display surface of FIG.

As shown in FIG. 7, when the discriminating tool 20 shown in FIG. 6 is superposed close to or in close contact with the partial display surface 2 of FIG. 4, in the hidden pattern region 12, the stripe pair 12 ₁ shown in FIG. The inclination angle α ₁₂ = 135 ° of the first wavy stripe 12 _1a or the second wavy stripe 12 _{1b is} the inclination angle α ₂₀ = 135 ° with respect to the reference line S of the straight transparent portion 20a and the straight opaque portion 20b of the discriminating tool 20. Since they are the same, a moire phenomenon occurs.

The Moire phenomenon, either the first wavy fringe 12 _1a and the second wavy stripes 12 _1b stripe pair 12 ₁ of the hidden pattern region 12 is substantially corresponding to the linear transparent portion 20a, substantially to the other linear opaque portion 20b As a result, the diffracted light by one of the first diffraction grating 12 ′ _{1a and} the second diffraction grating 12 ′ _{1b in} the hidden pattern region 12 is diffracted in the diffraction direction.

On the other hand, in the non-hidden pattern region 11, the inclination angle α ₁₁ = 45 ° of the first wavy stripe 11 _1a or the second wavy stripe 11 _1b of the stripe pair 11 ₁ is equal to the straight transparent portion 20a of the discriminator 20 and the straight line. Since the inclination angle α ₂₀ = 135 ° with respect to the reference line S of the opaque portion 20b is greatly different, no moire phenomenon occurs.

Therefore, the first diffraction grating 12 ′ _1a or the second diffraction grating 12 ′ _1b that is not hidden by the straight opaque portion 20b in the hidden pattern region 12 is exposed through the straight transparent portion 20a at a substantially half density, and is substantially half. Diffracted light is diffracted in the same direction with diffraction intensity.

  As a result, as shown in FIG. 8, in the partial display surface 2, the hidden pattern area 12 is observed to be relatively brighter and the non-hidden pattern area 11 is observed to be relatively darker. In this example, the hidden character “H” is discriminated. It becomes possible.

  FIG. 9 is an enlarged view of the partial display surface 2 including a hidden pattern by the light diffraction structure of the second embodiment.

  As shown in FIG. 9, on the partial display surface 2, the display patterns include a non-hidden pattern region 11 excluding the portion of the character “H” in the central portion of the background and a hidden pattern of the character “H” in the central portion. And region 12. Here, the letter “H” is configured as a hidden pattern.

  FIG. 10 is an enlarged view of a portion B surrounded by a broken line in FIG.

The first wavy stripes 11 _1a and the second wavy stripes 11 _1b (striped pair 11 ₁ ) constituting the non-hidden pattern region 11 have a repetition pitch d _11, and the first wavy stripes 12 _1a and second The repetition pitch d ₁₂ of the two wavy stripes 12 _1b (stripe pair 12 ₁ ) is used. In the second embodiment, the inclination angle α ₁₁ of the stripe pair 11 ₁ of the non-hidden pattern region 11 and the inclination angle α 12 of the stripe pair 12 ₁ of the hidden pattern region ₁₂ are both set to 45 °.

The first diffraction grating 11 ′ _1a of the first wavy stripe 11 _1a in the non-hidden pattern region 11 is selected at an inclination angle β _11a = 0 °. In addition, the second diffraction grating 11 ′ _1b of the second wavy stripe 11 _1b in the non-hidden pattern region 11 is selected at an inclination angle β _11b = 45 °.

The first diffraction grating 12 ′ _1a of the first wavy stripe 12 _1a in the hidden pattern region 12 is selected at an inclination angle β _12a = 0 °. In addition, the second diffraction grating 12 ′ _1b of the second wavy stripe 12 _1b in the hidden pattern region 12 is selected at an inclination angle β _12b = 45 °.

That is, in the display surface 2 of the second embodiment, _1a first diffraction grating 11 'first diffraction grating 12 of _1a and hidden pattern region 12' of the non-hidden pattern region 11 of the inclination angle beta _11a = 0 °, tilt angle The second diffraction grating 11 ′ _1b of the non-hidden pattern region 11 of β _11b = 45 ° and the second diffraction grating 12 ′ _1b of the hidden pattern region 12 are included at the same ratio.

In the first embodiment, the repetition pitch d ₁₁ of the stripe pair 11 _{1 in} the non-hidden pattern region ₁₁ and the repetition pitch d 12 of the stripe pair 12 _{1 in} the hidden pattern region ₁₂ are different. Further, the tilt angle alpha ₁₂ striped pairs 12 ₁ non-hidden stripe pair of pattern regions 11 11 ₁ tilt angle alpha ₁₁ and a hidden pattern region 12 is set so as to satisfy the 45 °.

The inclination angle β _11a of the first diffraction grating 11 ′ _{1a in} the non-hidden pattern area 11 and the inclination angle β _12a of the first diffraction grating 12 ′ _{1a in} the hidden pattern area ₁₂ are 0 °, and the second angle of the non-hidden pattern area 11 is 2nd. Since the inclination angle β _11b of the diffraction grating 11 ′ _1b and the inclination angle β _12b of the second diffraction grating 12 ′ _{1b in} the hidden pattern region 12 are 45 ° in common, they cannot be distinguished from each other in a normal visual state.

  Therefore, in a normal visual state without using a discriminator described later, the entire display surface 2 is observed in a state where there is no display pattern with uniform brightness, and the hidden character “H” cannot be discriminated.

  FIG. 11 is a plan view of an example of a discriminator for discriminating a hidden pattern on the partial display surface of FIG.

The discriminator 21 is a repetitive pattern of parallel straight transparent portions 21 a and straight opaque portions 21 b, and the repetitive pitch thereof is the same pitch d as the repetitive pitch d ₁₂ of the stripe pair 12 ₁ of the hidden pattern region 12 of the display surface 2. It has _21, linear transparent portion 21a, the inclination angle alpha with respect to the reference line S of the straight opaque portions 21b, have the same inclination angle alpha ₂₁ = 45 ° and the inclination angle alpha ₁₂ stripe pair 12 ₁ of the hidden pattern region 12.

  12 is a diagram showing a state in which the discriminating tool is superimposed on the partial display surface of FIG. 9, and FIG. 13 is a diagram showing a hidden pattern discriminated from the partial display surface of FIG.

As shown in FIG. 12, the discrimination device 21 as shown in FIG. 11, when superimposed in proximity or contact to the partial display surface 2 in FIG. 9, the hidden pattern region 12 shown in FIG. 10, stripe pair 12 ₁ The inclination angle α ₁₂ = 45 ° of the first wavy stripe 12 _1a or the second wavy stripe 12 _{1b is} the inclination angle α ₂₁ = 45 ° with respect to the reference line S of the straight transparent portion 21a and the straight opaque portion 21b of the discrimination tool 20. with the same, since the repetition pitch d ₁₂ striped pairs 12 ₁ is the same as the repetition pitch d ₂₁ of the linear transparent portion 21a and a linear non-transparent portion 21b of the discrimination member 20, the moire phenomenon occurs.

Due to this moire phenomenon, either the first wavy stripe 12 _1a or the second wavy stripe 12 _1b of the stripe pair 12 ₁ substantially corresponds to the straight transparent portion 21a, and the other substantially corresponds to the straight opaque portion 21b. As a result, the diffracted light by one of the first diffraction grating 12 ′ _1a or the second diffraction grating 12 ′ _1b is diffracted in the diffraction direction.

In contrast, the determination in the non-hidden pattern region 11, the repetition pitch d ₁₁ of the first stripe pair 11 ₁ of the first wavy fringe 11 _1a or the second wavy fringe 11 _1b shown in FIG. 10, as shown in FIG. 11 Since it differs with respect to the repeating pitch d ₂₁ between the linear transparent portion 21a and the linear opaque portion 21b of the tool 21, no moire phenomenon occurs.

Accordingly, the first diffraction grating 12 ′ _1a or the second diffraction grating 12 ′ _1b that is not hidden by the straight opaque portion 21b in the hidden pattern region 12 is exposed through the straight transparent portion 21a at a substantially half density, and is substantially half. Diffracted light is diffracted in the same direction with diffraction intensity.

  As a result, as shown in FIG. 13, in the partial display surface 2, the hidden pattern area 12 is observed to be relatively brighter and the non-hidden pattern area 11 is observed to be relatively darker. In this example, the hidden character “H” is discriminated. It becomes possible.

  Next, a third embodiment will be described.

  FIG. 14 is an enlarged view of the partial display surface 2 including a hidden pattern by the light diffraction structure of the third embodiment.

  On the display surface 2, the display pattern includes a square pattern at the center, a pattern obtained by removing the square area at the center from the background rectangle, and the letter “H” superimposed on them. Here, the letter “H” is configured as a hidden pattern.

And the area | region arrange | positioned in parallel on this display surface 2 is as follows.
The first non-hidden pattern area 11a: an area obtained by removing the central square area and the letter “H” from the rectangle. • the first hidden pattern area 12a: an area extending out of the central square area by the letter “H”. 2 Non-hidden pattern area 11b: Area that does not overlap with the letter “H” in the central square area Second hidden pattern area 12b: Area of the letter “H” in the central square area

  That is, four patterns of the first non-hidden pattern region 11a, the first hidden pattern region 12a, the second non-hidden pattern region 11b, and the second hidden pattern region 12b constitute the display surface 2 in parallel. The hidden pattern character “H” includes a first hidden pattern region 12a and a second hidden pattern region 12b arranged in parallel.

  FIG. 15 is an enlarged view of a portion C surrounded by a broken line in FIG.

In the first non-hidden pattern region 11a other than the character pattern “H”, the inclination angle α _11a of the first wavy stripe 11a _1a and the second wavy stripe 11a _1b (the stripe pair 11a ₁ ) is selected to be 45 °. Similarly, in the second non-hidden pattern region 11b other than the character pattern “H”, the inclination angle α _11b of the first wavy stripe 11b _1a and the second wavy stripe 11b _1b (the stripe pair 11b ₁ ) is selected to be 45 °.

In the first hidden pattern region 12a constituting the character pattern H, the inclination angle α _12a of the first wavy stripe 12a _1a and the second wavy stripe 12a _1b (the stripe pair 12a ₁ ) is selected to be 135 °. Similarly, in the second hidden pattern region 12b constituting the character pattern H, the inclination angle α _12b of the first wavy stripe 12b _1a and the second wavy stripe 12b _1b (the stripe pair 12b ₁ ) is selected to be 135 °.

Furthermore, in the third embodiment, the stripe pair 11a ₁ of the first non-hidden pattern area 11a, the stripe pair 11b _{1 of} the second non-hidden pattern area 11b, the stripe pair 12a _{1 of} the first hidden pattern area 12a, and the second hidden pattern. The repetition pitch d of the stripe pair 12b _{1 in} the pattern region 12b is all set to be the same.

In the first non-hidden pattern region 11a outside the central square, the inclination angle β _11a1 of the first diffraction grating 11′a _1a of the first wavy stripe 11a _1a is 0 °, and the second diffraction of the second wavy stripe 11a _1b . The inclination angle β _11a2 of the grating 11′a _1b is set to 45 °. In addition, in the second non-hidden pattern region 11b inside the central square, the inclination angle β _11b1 of the first diffraction grating 11′b _1a of the first wavy stripe 11b _1a is 90 ° and the second wavy stripe 11b _1b The inclination angle β _11b2 of the two diffraction gratings 11′b _1b is set to 135 °.

In the first hidden pattern region 12a outside the central square, the inclination angle β _12a1 of the first diffraction grating 12′a _1a of the first wavy stripe 12a _1a is 0 °, and the second diffraction grating of the second wavy stripe 12a _1b . The inclination angle β _12a2 of 12′a _1b is set to 45 °. In addition, in the second hidden pattern region 12b inside the center square, the inclination angle β _12b1 of the first diffraction grating 12′b _1a of the first wavy stripe 12b _1a is 90 °, and the second wavy stripe 12b _1b is the second of the second wavy stripe 12b _1b . The inclination angle β _12b2 of the diffraction grating 12′b _1b is set to 135 °.

  FIG. 16 is a view of the partial display surface 2 as viewed visually.

As shown in FIG. 15, the first diffraction grating 11′a _1a (inclination angle β _11a1 = 0 °) and the second diffraction grating 11′a _1b (inclination) of the first non-hidden pattern region 11a outside the central square. angle β _11a2 = 45 °), and, the first diffraction grating 12'a _1a (inclination angle β _12a1 = 0 °) and a second diffraction grating 12'a _1b (tilt angle beta _12a2 = 45 in the first hidden pattern area 12a °) are included in the same proportions. Therefore, as shown by 13a in FIG. 16, the first pattern appears as a uniform area of the same color with the same brightness in a normal viewing state.

Similarly, as shown in FIG. 15, the first diffraction grating 11′b _1a (inclination angle β _11b1 = 90 °) and the second diffraction grating 11′b in the second non-hidden pattern region 11b inside the central square. _1b (inclination angle β _11b2 = 135 °), and the first diffraction grating 12′b _1a (inclination angle β _12b1 = 90 °) and second diffraction grating 12′b _1b (inclination angle β) in the second hidden pattern region 12b. _12b2 = 135 °) are included at the same rate. Accordingly, as shown in 13b of FIG. 16, the second pattern appears as a uniform region of the same color with the same brightness in a normal viewing state.

Such a partial display surface 2 has a repetitive pattern of parallel linear transparent portions 20a and straight opaque portions 20b as shown in a plan view in FIG. It is the same as the pitch d, and the inclination angle α = 135 ° with respect to the reference line S of the straight transparent portion 20a and the straight opaque portion 20b is the stripe pair 12a _{1 of} the first hidden pattern region 12a constituting the hidden character pattern “H” and superposition of the second hidden pattern region 12b discrimination device 20 of the same 135 ° and the inclination angle of the fringes pair 12b ₁ of the proximity or contact to the moire phenomenon.

Due to this moire phenomenon, _one of the first wavy stripe 12a _{1a and} the second wavy stripe 12a _1b of the stripe pair 12a ₁ of the first hidden pattern region 12a substantially corresponds to the straight transparent portion 20a, and the other corresponds to the straight opaque portion 20b. As a result, the diffracted light by one of the first diffraction grating 12′a _1a or the second diffraction grating 12′a _1b in the first hidden pattern region 12a is diffracted in the diffraction direction.

Similarly, either the first wavy stripe 12b _1a or the second wavy stripe 12b _1b of the stripe pair 12b ₁ of the second hidden pattern region 12b substantially corresponds to the straight transparent portion 20a, and the other corresponds to the straight opaque portion 20b. As a result, the diffracted light by one of the first diffraction grating 12′b _1a or the second diffraction grating 12′b _1b in the second hidden pattern region 12b is diffracted in the diffraction direction.

On the other hand, in the first non-hidden pattern region 11a, the inclination angle α _11a = 45 ° of the first wavy stripe 11a _1a or the second wavy stripe 11a _1b of the stripe pair 11a ₁ is the linear transparent portion 20a of the discriminator 20. Since the inclination angle α of the straight opaque portion 20b with respect to the reference line S is significantly different from 135 °, no moire phenomenon occurs.

Similarly, in the second non-hidden pattern region 11b, the inclination angle α _11b = 45 ° of the first wavy stripe 11b _1a or the second wavy stripe 11b _1b of the stripe pair 11b ₁ is the straight transparent portion 20a, straight line Since the inclination angle α of the opaque portion 20b with respect to the reference line S is significantly different from 135 °, no moire phenomenon occurs.

Accordingly, the first diffraction grating 12′a _1a or the second diffraction grating 12′a _1b that is not hidden by the linear opaque portion 20b in the first hidden pattern region 12a, and the linear opaque portion 20b in the second hidden pattern region 12b. The first diffraction grating 12′b _1a or the second diffraction grating 12′b _1b that is not hidden is exposed at approximately half the density through the linear transparent portion 20a, and diffracts the diffracted light in the same direction with approximately half the diffraction intensity. To do.

  As a result, as shown in FIG. 8, in the partial display surface 2, the first hidden pattern area 12a and the second hidden pattern area 12b are relatively brighter, and the first non-hidden pattern area 11a and the second non-hidden pattern area 11b is observed relatively darker, and in this example, the hidden character “H” can be discriminated.

Note that the first wavy stripes 12a _1a or the second wavy stripes 12a _1b stripe pairs 12a ₁ of the first hidden pattern area 12a, the first wavy stripes 12b _1a stripe pair 12b ₁ of the second hidden pattern region 12b or the second The wavy stripes 12b _1b are preferably formed continuously. By forming them continuously, the hidden character “H” can be distinguished brighter.

  FIG. 17 is an enlarged view of the partial display surface 2 including a hidden pattern by the light diffraction structure of the fourth embodiment mobile phone.

The partial display surface 2 has a square area in a rectangle, and the letter “H” and the letter “T” are drawn in parallel so as to partially overlap the square area in the rectangle. , “H” character inner region H ₁₁ (first hidden pattern region of the first pattern) located within the square region and character inner region H ₁₂ (second symbol of the second symbol) located outside the square region. 1 hidden pattern area), an inner area T _{11 of the} character located within the square area of the character “T” (second hidden pattern area of the first pattern), and an inner area T _{12 of the} character located outside the square area. (The second hidden pattern area of the second pattern), the area O ₁₁ other than the letters “H” and “T” in the square area (the first non-hidden pattern area of the first pattern), and the outside of the square area From the outer region O ₁₂ (the first non-hidden pattern region of the second pattern) of the characters “H” and “T” For example, it is set as follows.

Region H ₁₁
Tilt angle of stripe pair: 135 °
Repeat pitch of stripe pairs: 0.08mm
Tilt angle of first diffraction grating: 0 °
Tilt angle of second diffraction grating: 45 °
Region H ₁₂
Tilt angle of stripe pair: 135 °
Repeat pitch of stripe pairs: 0.08mm
Tilt angle of the first diffraction grating: 30 °
Tilt angle of second diffraction grating: 75 °
Region T ₁₁
Tilt angle of stripe pair: 45 °
Repeat pitch of stripe pairs: 0.12 mm
Tilt angle of first diffraction grating: 0 °
Tilt angle of second diffraction grating: 45 °
Region T ₁₂
Tilt angle of stripe pair: 45 °
Repeat pitch of stripe pairs: 0.12 mm
Tilt angle of the first diffraction grating: 30 °
Tilt angle of second diffraction grating: 75 °
Region O ₁₁
Tilt angle of stripe pair: 90 °
Repeat pitch of stripe pairs: 0.16 mm
Tilt angle of first diffraction grating: 0 °
Tilt angle of second diffraction grating: 45 °
Region O ₁₂
Tilt angle of stripe pair: 90 °
Repeat pitch of stripe pairs: 0.16 mm
Tilt angle of the first diffraction grating: 30 °
Tilt angle of second diffraction grating: 75 °

With such an arrangement, in the partial display surface 2, the first diffraction grating having an inclination angle of 0 ° in any of the regions H ₁₁ , T _11, and O ₁₁ , which are regions within the square, The second diffraction grating having an inclination angle of 45 ° is included in the same ratio. In each of the areas H ₁₂ , T _12, and O ₁₂ that are areas outside the square of the display surface 2, the first diffraction grating having an inclination angle of 30 ° and the second diffraction grating having an inclination angle of 75 ° are included. The diffraction grating is included in the same ratio.

  That is, although the repetition pitch of the stripe pair is different in all cases, the repetition pitch of the stripe pair is set to satisfy 1/5 mm or less, so that the area in the square of the display surface 2 is uniform in the normal viewing state. The areas outside the square also appear to be uniform, and the diffraction directions are different between the inside and outside the square, so that they can be seen and distinguished from each other. Therefore, in a normal visual state without using a discriminator, the display surface 2 is observed as a display pattern including a square within a rectangle, and the hidden characters “H” and “T” are discriminated similarly to the form shown in FIG. Impossible.

  FIG. 18 is a diagram illustrating a state where the hidden character “H” is determined from the partial display surface 2.

A repeating pattern of parallel linear transparent portion 20a and a linear non-transparent portion 20b as shown in FIG. 6, the linear transparent portion 20a, the linear opaque portion 20b inclination angle of stripe pairs of region H ₁₁ and the area H ₁₂ When a discriminating tool 20 having an inclination angle of 45 ° and a repetition pitch equal to the repetition pitch of the stripe pair of the region H ₁₁ and the region H ₁₂ of 0.08 mm is brought close to or in close contact with the partial display surface 2, the region H ₁₁ and region H ₁₂ appear brighter or darker depending on the viewing direction, and other regions T ₁₁ , T ₁₂ , O ₁₁ , and O ₁₂ are observed relatively darker or brighter, and regions H ₁₁ , H 12 ₁₂ and the regions T ₁₁ , T ₁₂ , O ₁₁ , and O ₁₂ are observed with a mutual contrast, and the hidden character “H” can be discriminated as shown in FIG. Note that the brightness and color look slightly different depending on the position of the illumination light source between the square inner region H ₁₁ and the outer region H ₁₂ of the letter “H”, but in the normal viewing environment, many light sources and Since there is a surface light source, the difference in brightness and color inside the “H” character does not disturb the determination of the hidden character “H”.

  FIG. 19 is a diagram showing a state where the hidden character “T” is discriminated from the partial display surface 2.

Next, a repeating pattern of parallel straight transparent portion 21a and a linear non-transparent portion 21b as shown in FIG. 11, the linear transparent portion 21a, the linear opaque portion 21b inclination angle of the region T ₁₁ and the region T ₁₂ When the discriminating tool 20 which is equal to the inclination angle 45 ° of the stripe pair and whose repetition pitch is equal to the repetition pitch 0.12 mm of the stripe pair in the regions T ₁₁ and T ₁₂ is brought close to or in close contact with the partial display surface 2. , appear dark or brighter according to the region T _11, T ₁₂ in the viewing direction, the other regions _{H 11, H 12, O 11} , O brightly observed from either relatively dark ₁₂ opposite the regions T ₁₁ , T ₁₂ and the regions H ₁₁ , H ₁₂ , O ₁₁ , O ₁₂ are observed with a contrast between them, and the hidden character “T” can be discriminated as shown in FIG. It should be noted that although the brightness and color look slightly different depending on the position of the illumination light source between the square inner region T ₁₁ and the outer region T ₁₂ of the letter “T”, many light sources and Since there is a surface light source, the difference in brightness and color inside the character “TB” does not disturb the determination of the hidden character “T”.

  20 is a plan view of an example of a discriminating tool for discriminating the hidden pattern on the partial display surface of FIG. 21, and FIG. 21 is a diagram showing a state in which the hidden characters “H” and “T” are discriminated from the partial display surface 2. is there.

Next, a repeating pattern of parallel linear transparent portions 22a and linear opaque portions 22b as shown in FIG. 20, where the inclination angles of the linear transparent portions 22a and the linear opaque portions 22b are the regions O ₁₁ and O ₁₂ . When the discriminating tool 22 which is equal to the inclination angle 90 ° of the stripe pair and whose repetition pitch is equal to the repetition pitch 0.16 mm of the stripe pair in the region O ₁₁ and the region O ₁₂ is brought close to or in close contact with the partial display surface 2. The regions O ₁₁ and O ₁₂ appear brighter or darker depending on the viewing direction, and the other regions H ₁₁ , H ₁₂ , T ₁₁ , and T ₁₂ are observed relatively darker or brighter, as shown in FIG. Thus, the hidden character “HT” can be discriminated. It should be noted that although the brightness and color look slightly different depending on the position of the illumination light source between the region O ₁₁ and the region O ₁₂ outside the hidden character “HT”, there are many light sources and surface light sources in a normal viewing environment. Therefore, the difference in brightness and color outside the “hidden character” HT does not disturb the determination of the hidden character “HT”.

  Next, examples of wavy stripes formed on the partial display surface 2 from the first embodiment to the fourth embodiment will be described.

In Example 1, the pitch d ₂ of the pitch d ₁ and the second wavy stripes 6 ₂ of the first wavy stripes 6 ₁ wavy stripe pair 6 illustrated in FIG. 3 85 .mu.m, the height of the unevenness and 60μm or 120 [mu] m, 1 mm The visibility of the moiré pattern when the number of the irregularities was changed was relatively compared with the straight stripes. In Table 1 and Table 2 below, the case where the number of irregularities is 0 corresponds to the case of a straight stripe, the visibility in the case of a straight stripe is △, and the case where it is easier to see than the straight stripe is ○. The case where it is easy to observe is ◎, and the case where it is difficult to visually recognize is ×.

Table 1

Unevenness height: 60 μm
Number of bumps 0 0.25 0.5 1 2 5 10
Visibility △ ○ ◎ ◎ ○ ○ △

Table 2

Unevenness height: 120 μm
Number of bumps 0 0.25 0.5 1 2 5 10
Visibility △ ○ ◎ ◎ ○ ○ △

  As described above, the visibility of the wavy stripes was better than the visibility of the straight stripes in both cases where the height of the irregularities of the wavy stripes was 60 μm and 120 μm.

Next, in Example 2, 85 .mu.m pitch d ₂ of the pitch d ₁ and the second wavy stripes 6 ₂ of the first wavy stripes 6 ₁ 3, the first wavy stripes 6 ₁ and the second wavy stripes 6 ₂ 1mm The visibility of the moiré pattern when the height of the unevenness was changed by setting the number of the unevenness per round to 0.5 or 1 was relatively compared with the straight stripes. In Table 3 and Table 4 below, the case where the number of irregularities is 0 corresponds to the case of a straight stripe, the visibility in the case of a straight stripe is △, and the case where it is easier to visually recognize than the straight stripe is ○. The case where it is easy is marked with ◎, and the case where it is difficult to visually recognize is marked with ×.

Table 3

Number of irregularities: 0.5 / mm
Uneven height 0 5 10 15 20 25 30
Visibility △ ○ ◎ ◎ ◎ ○ △

Table 4

Number of irregularities: 1 / mm
Uneven height 0 5 10 15 20 25 30
Visibility △ ○ ◎ ◎ ◎ ○ △

  Thus, the visibility of the wavy stripes was better than the visibility of the straight stripes in both cases where the number of irregularities of the wavy stripes was 0.5 / mm and 1 / mm.

  FIG. 22 is a diagram for explaining borders provided around each pattern.

  A pattern (square pattern in FIG. 16) that can be discriminated in a normal visual state without using a discriminator, a hidden pattern (character pattern “H” in FIGS. 8, 13, 17, and 21; FIGS. 19 and 21); The character pattern “T” in FIG. 22 is surrounded by a fringe pair having a period shifted by a half period from the period of the fringe pair 6 constituting the pattern P, as shown in FIG. 'Can also be formed. By applying such a border P ′, it is easy to discriminate a hidden pattern that is difficult to discriminate using a discriminating tool, and the effect of sharpening the border even for a discriminable pattern is obtained. is there.

  In the above description, the first diffraction grating and the second diffraction grating constituting the fringe pair are selected so as to satisfy at least one of different tilt angles or different grating pitches of the diffraction grating. By configuring the two elements of the inclination angle and the lattice pitch to be different, the effect of the hidden pattern can be further enhanced.

  Further, in the above, the discriminators 20 to 22 are repetitive patterns of parallel linear transparent portions 20a to 22a and straight opaque portions 20b to 22b, and the repetitive pitch of any hidden pattern region on the display surface. It has the same pitch as the repetitive pitch of the stripe pair, and the inclination angle with respect to the reference line of the straight transparent portions 20a to 22a and the straight opaque portions 20b to 22b may be the same as the inclination angle of the stripe pair in the hidden pattern region. As described above, when such discriminators 20 to 22 are brought close to the printed matter 4 at a predetermined angle, a hidden pattern is displayed via the discriminators 20 to 22. When the hidden pattern displayed via the determination tools 20 to 22 is a predetermined pattern, it is determined that the printed product is a legitimate product (genuine product) supplied from a correct supplier.

  The discriminating tools 20 to 22 are those in which a discriminating pattern is formed on a transparent base substrate in order that an observer must be able to visually observe the light that has passed through the discriminating tool and is applied to the hidden pattern of the printed matter. Use. The base substrate is preferably higher in transparency. In addition, since the discriminators 20 to 22 are frequently used, those in which the base substrate is fixed with a strong frame member are often used. A handle or the like can be attached to the frame material, thereby preventing the transparent base substrate of the discriminating tools 20 to 22 from being stained with fingerprints or oil.

  When discriminating the hidden pattern, the discriminating tools 20 to 22 are discriminated so as to be close to the printed material 4 on which the display body 1 is formed. Although it is possible to discriminate the hidden pattern from the close contact state to a certain distance, since the moire phenomenon is used, it is difficult to discriminate if the distance between the display body 1 and the discriminators 20 to 22 is too large. Become.

  By the way, the discriminators 20 to 22 can be configured with a line pattern in which the inclination angles of the linear transparent portions 20a to 22a and the linear opaque portions 20b to 22b with respect to the reference line S are a predetermined angle α. Each line is a repeated pattern in which the linear transparent portions 20a to 22a and the colored linear opaque portions 20b to 22b are paired. The width of the transparent transparent transparent portions 20a to 22a and the colored linear opaque portions 20b to 20b The width of 22b may be the same or different.

  The discriminators 20 to 22 can also be configured by a halftone dot pattern instead of such a line pattern. A directional halftone dot is composed of a point where a transparent part and a colored part are independent, or two points connected in a chain, and a line connecting the transparent parts (a chain) A pair of (chain-like) lines connecting the colored portions forms a discrimination pattern corresponding to the straight transparent portions 20a to 22a and the straight opaque portions 20b to 22b.

  By the way, as shown in FIG. 11, when using a discrimination pattern consisting of a repeat pattern of parallel straight transparent portions 21a and straight opaque portions 21b as the discriminator 21, a part of the repeat pattern is enlarged in FIG. As shown, when the width of the straight transparent portion 21a is a and the width of the straight opaque portion 21b is b, a / b≈1, that is, the straight transparent portion 21a and the straight opaque portion 21b may have substantially the same width. However, it is desirable to set a / b in the range of 2/3 to 1/4, that is, the width of the linear transparent portion 21a is smaller than the width of the linear opaque portion 21b. The reason is that in the range of 2/3 ≧ a / b ≧ ¼, when the discriminating tool 21 is overlapped with the display surface 2 close to or in close contact, the hidden pattern “H” or the like is observed with good contrast. On the other hand, if a / b exceeds 2/3, the amount of light that can be seen through the discriminator 21 becomes too bright and too bright and the contrast is lowered, making it difficult to see the hidden pattern. This is because if it is less than / 4, the amount of light is too small and it becomes dark and it is difficult to see the hidden pattern.

  FIG. 24 is a diagram showing a discriminator of another embodiment, and FIG. 25 is a diagram showing a wavy transparent portion and a wavy opaque portion of the discriminator.

  Further, as the discriminating tool 20 ', as shown in FIG. 24, a discriminating pattern including a repeating pattern of parallel wavy transparent portions 20'a and wavy opaque portions 20'b may be used.

The discriminating tool 20 ′ has a wavy transparent portion 20′a and a wavy opaque portion 20′b. When the repeating pitch of the wavy transparent portion 20′a is d ₁ and the repeating pitch of the wavy opaque portion 20′b is d ₂ , the repeating pitch of the wavy transparent portion 20′a and the wavy opaque portion 20′b is d = d _1. + a d _2. Here, the repeating pitch d of the wavy transparent portion 20′a and the wavy opaque portion 20′b is preferably set to d ≦ 1/5 mm.

Further, the wavy transparent portion 20′a has a convex portion and a concave portion having a height h alternately with respect to the repetition pitch d ₁ to form a waveform. Similarly, the wavy opaque portion 20′b has a waveform having alternating convex portions and concave portions having a height h with respect to the repetition pitch d ₂ . The number of irregularities is preferably 0.5 to 5 / mm. Further, the height h of the unevenness is preferably 5 to 20% of the repeating pitch d ₁ of the wavy transparent portion 20′a and the repeating pitch d ₂ of the wavy opaque portion 20b.

  Next, examples of the wavy transparent portion 20'a and the wavy opaque portion 20'b formed on the discriminating tool 20 'will be described.

In Example 3, the pitch d ₁ of the wavy transparent portion 20′a and the pitch of the wavy opaque portion 20′b shown in FIG. 25 are set to 85 μm, the height of the unevenness is set to 60 μm or 120 μm, and the number of unevenness per 1 mm is changed. The visibility of the moire pattern at the time of making it comparative was compared with the discriminating tool 20 of the linear transparent part 20a and the linear opaque part 20b shown in FIG. 6, FIG. 11, and FIG. In Tables 5 and 6 below, the case where the number of irregularities is 0 corresponds to the case of the linear transparent portion 20a and the linear opaque portion 20b, and the visibility in the case of the linear transparent portion 20a and the linear opaque portion 20b is Δ. The case where it is easier to visually recognize than the straight transparent portion 20a and the straight opaque portion 20b is indicated as ◯, the case where it is more easily visible as ◎, and the case where it is difficult to visually recognize as ×.

Table 5
Unevenness height: 60 μm
Number of bumps 0 0.25 0.5 1 2 5 10
Visibility △ ○ ◎ ◎ ○ ○ △

Table 6
Unevenness height: 120 μm
Number of bumps 0 0.25 0.5 1 2 5 10
Visibility △ ○ ◎ ◎ ○ ○ △

  Thus, in both cases where the height of the irregularities of the wavy transparent portion 20′a and the wavy opaque portion 20′b is 60 μm and 120 μm, the wavy line is more than the visibility in the case of the straight transparent portion 20a and the straight opaque portion 20b. The visibility of the transparent portion 20′a and the wavy opaque portion 20′b was good.

Next, in Example 4, the pitch d ₁ of the wavy transparent portion 20′a and the pitch d ₂ of the wavy opaque portion 20′b are 85 μm in FIG. 3, and 1 mm of the wavy transparent portion 20′a and the wavy opaque portion 20′b. The visibility of the moire pattern when changing the height of the unevenness was set to be 0.5 or 1, and the visibility of the moire pattern was relatively compared with the linear transparent portion 20a and the linear opaque portion 20b. In Tables 7 and 8 below, the case where the number of irregularities is 0 corresponds to the case of the linear transparent portion 20a and the linear opaque portion 20b, and the visibility in the case of the linear transparent portion 20a and the linear opaque portion 20b is Δ. The case where it is easier to visually recognize than the straight transparent portion 20a and the straight opaque portion 20b is indicated as ◯, the case where it is more easily visible as ◎, and the case where it is difficult to visually recognize as ×.

Table 7

Number of irregularities: 0.5 / mm
Uneven height 0 5 10 15 20 25 30
Visibility △ ○ ◎ ◎ ◎ ○ △

Table 8
Number of irregularities: 1 / mm
Uneven height 0 5 10 15 20 25 30
Visibility △ ○ ◎ ◎ ◎ ○ △

  In this way, in the case of the straight transparent portion 20a and the straight opaque portion 20b, the wavy transparent portion 20′a and the wavy opaque portion 20′b have the number of irregularities of 0.5 / mm and 1 / mm. The visibility of the wavy transparent portion 20′a and the wavy opaque portion 20′b was better than the visibility.

  By the way, in the above description, the diffraction grating which comprises the light diffraction structure of the display surface 2 of the display body 1 shown in FIG. 1 was not demonstrated in detail. Usually, as the diffraction grating used for the display surface 2 that is attached to a printed material or the like, a reflection type diffraction grating is used in which a metal reflective film is provided on the relief surface or plane of the relief grating having an uneven relief structure by vapor deposition or the like. Other than that, it is a reflective type in which a metal reflective film is provided on the back surface of an amplitude type diffraction grating whose amplitude changes periodically or a refractive index changes periodically to form a phase type diffraction grating. A diffraction grating having a diffraction grating composed of interference fringes in a volume type photosensitive material or the like may be used.

  Of course, the display surface may be a transmission type instead of the reflection type, and the diffraction grating may be a transmission type diffraction grating.

  Now, the display body (or only the display surface 2) which has the partial display surface containing a hidden pattern like this embodiment can be comprised in various forms, such as transfer foil, a label, and a film. In the case of the transfer foil form, for example, it can be applied to gift certificates, credit cards, packages, etc. In the case of the label form, it can be applied to packages such as software, cartridges, pharmaceuticals, etc., and in the case of the film form, For example, the film can be micro-slit to a width of about 1 to 2 mm, and the sheet can be made into paper together to prevent forgery. In the case of the label form, a brittle layer is interposed in the layer structure, and when the label is peeled off for counterfeiting, the label is peeled off from the brittle layer and the display body is peeled off for counterfeiting. Can be difficult (brittle label). Hereinafter, an example of a layer configuration and a manufacturing process thereof when the display body including the hidden pattern by the light diffraction structure of the present invention is configured in each form of a transfer foil, a label, a brittle label, and a film will be described.

  FIG. 26 is a cross-sectional view showing a layer structure in the case where a display body containing a hidden pattern by the light diffraction structure of the present invention is configured as a transfer foil 31, and the structure will be described according to the manufacturing method. A release layer 45 is applied on a substrate 44 made of a resin film, a diffraction grating forming layer 41 is applied on the release layer 45, and a diffraction grating original plate having an uneven relief structure is embossed on the diffraction grating forming layer 41. A diffraction grating having a relief structure is duplicated, and a reflective layer is deposited on the duplicated relief diffraction grating surface to form a reflective diffraction grating 43, and a heat seal layer is formed on the reflective layer side of the diffraction grating 43. 46 is applied to complete a transfer foil 31 having a layer structure as shown in FIG.

  Here, as a resin film which comprises the base material 44, a polypropylene resin film, a polycarbonate resin film, or a polyethylene terephthalate resin film etc. are preferable, and in addition to these, biaxially-stretched polyethylene terephthalate resin excellent in mechanical strength. Film is suitable.

  Further, the resin constituting the release layer 45 depends on the material of the base material 44 and the material of the diffraction grating forming layer 41 adhered to the release layer 45, but the polyester resin, the acrylic skeleton resin, and the vinyl chloride-vinyl acetate copolymer. A resin, a two-component blend resin of cellulose acetate and a thermosetting acrylic resin, a melamine resin, or a nitrocellulose resin can be used. For example, when the base material 44 is a polyethylene terephthalate resin (PET) film, a polyester resin is preferable in terms of the adhesion between the release layer 45 and the base material 44. To these resins, a wax such as polyethylene wax or a silicone resin may be added to improve the peelability. The release layer 45 is prepared by dissolving or dispersing the above resin using an appropriate solvent or dispersant, and preparing a composition suitable for coating or printing by using a known coating method or printing method. Can be laminated.

  Moreover, as a synthetic resin which comprises the diffraction grating formation layer 41, thermoplastic resins, such as polyvinyl chloride, an acrylic resin (for example, PMMA), a polystyrene, a polycarbonate, unsaturated polyester, melamine, an epoxy, polyester (meth) acrylate, Thermosetting resins such as urethane (meth) acrylates, epoxy (meth) acrylates, polyether (meth) acrylates, polyol (meth) acrylates, melamine (meth) acrylates, triazine-based acrylates, respectively, or the above thermoplastic resins And thermosetting resin can be used as a mixture, and furthermore, thermoforming materials having radically polymerizable unsaturated groups, or radically polymerizable unsaturated monomers added to these, and ionizing radiation curable Can be used. In addition, photosensitive materials such as silver salt, dichromated gelatin, thermoplastic, diazo photosensitive material, photoresist, ferroelectric, photochromic material, thermochromic material, chalcogen glass, and the like can be used.

  Formation of the concavo-convex relief structure diffraction grating on the synthetic resin layer can be formed by a conventionally known method using the above-described materials. For example, by using an original plate in which the diffraction grating is recorded in a concavo-convex shape as a press mold, the original plate is overlaid on the resin layer and heated and pressure-bonded by an appropriate means such as a heating roll, whereby the concavo-convex pattern of the original plate is formed. Can be duplicated. Alternatively, the original plate can be superimposed on an ultraviolet curable resin layer, and the resin layer can be cured by irradiating ultraviolet rays to reproduce the concave / convex pattern of the original plate.

  As a material constituting the reflective layer 42, Mg, Al, Ti, Cr, Cu, Zn, Ga, Ge, Se, Rb, Pd, Ag, Cd, In, Sn, Sb, Te, Au, Pb, or A metal such as Bi or an oxide thereof or a nitride thereof is used alone or in combination to form a thin film. Among these, when a metal thin film layer is used as the reflective layer 42, Al, Cr, Ni, Ag, Au, or the like is particularly preferable.

  The reflective layer 42 is formed by a known thin film forming method such as a vacuum deposition method, a sputtering method, or an ion plating method.

  Examples of the material constituting the heat seal layer 46 include an ethylene-vinyl acetate copolymer resin, a polyamide resin, a polyester resin, a polyethylene resin, an ethylene-isobutyl acrylate copolymer resin, a butyral resin, polyvinyl acetate, and a copolymer thereof. A coalesced resin, a cellulose derivative, a polymethyl methacrylate resin, a polyvinyl ether resin, a polyurethane resin, a polycarbonate resin, a polypropylene resin, an epoxy resin, or a phenol resin can be used. Alternatively, thermoplastic elastomers such as SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), SEBS (styrene-ethylene-butylene-styrene block copolymer), or reactive hot melt resins May be used.

  FIG. 27 is a cross-sectional view showing a layer structure when a display body containing a hidden pattern by the light diffraction structure of the present invention is configured as a label 32. The structure will be described in accordance with the manufacturing method. Transparent resin such as PET A diffraction grating forming layer 41 is coated on a substrate 44 made of a film, and a diffraction grating original plate having an uneven relief structure is embossed on the diffraction grating forming layer 41 to replicate the diffraction grating having the uneven relief structure, and the replicated relief A reflective diffraction grating 43 is formed by vapor-depositing a reflective layer 42 on the diffraction grating surface, an adhesive layer 47 is applied to the reflective layer 42 side of the diffraction grating 43, and the adhesive layer 47 is used for protection. A separator (release paper) 48 is laminated to complete a label 32 having a layer structure as shown in FIG.

  Here, the materials constituting the substrate 44, the diffraction grating formation layer 41, and the reflection layer 42 are the same as those in the case of FIG.

  Examples of the adhesive constituting the adhesive layer 47 include polyvinyl acetate resin, polyvinyl alcohol, polyvinyl acetal (polyvinyl formal, polyvinyl butyral, etc.), cyanoacrylate, polyvinyl alkyl ether, polyvinyl chloride, polyamide, polymethyl methacrylate, nitrocellulose. , Cellulose acetate, thermoplastic epoxy, polystyrene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, urea resin, melamine resin, phenol resin, resorcinol resin, furan resin, epoxy resin, unsaturated polyester resin, polyurethane resin, Polyimide, polyamideimide, polybenzimidazole, polybenzothiazole, etc., or rubber-based natural rubber, recycled rubber, styrene-butadiene rubber, acrylo Tolyl - butadiene rubber, chloroprene rubber, butyl rubber, polysulfide rubber, silicone rubber, polyurethane rubber, stereo rubber (synthetic natural rubber), ethylene-propylene rubber, block copolymer rubbers (SBS, SIS, SEBS, etc.) can be used.

  Further, as the separator (release paper) 48, a conventionally known paper or a film substrate subjected to a release treatment can be used.

  FIG. 28 is a cross-sectional view showing a layer structure in the case where the display body containing the hidden pattern by the light diffraction structure of the present invention is configured as the brittle label 33. The structure will be described according to the manufacturing method thereof. A brittle layer 49 is applied on a substrate 44 made of a transparent resin film, a diffraction grating forming layer 41 is applied on the brittle layer 49, and a diffraction grating original plate having an uneven relief structure is embossed on the diffraction grating forming layer 41. Then, the diffraction grating having the concavo-convex relief structure is duplicated, and a reflection type diffraction grating 43 is formed by vapor-depositing the reflection layer 42 on the duplicated relief diffraction grating surface, and the diffraction grating 43 is formed on the reflection layer 42 side. An adhesive layer 47 is applied, and a separator (release paper) 48 is laminated on the adhesive layer 47 to complete the brittle label 33 having a layer structure as shown in FIG.

  Here, the materials constituting the substrate 44, the diffraction grating forming layer 41, the reflective layer 42, the adhesive layer 47, and the separator (release paper) 48 are the same as those in FIG.

  As the material constituting the brittle layer 49, the same series as the resin constituting the peeling layer 45 in the case of FIG. 26 is used.

  FIG. 29 is a cross-sectional view showing a layer structure in the case where the display body containing the hidden pattern by the light diffraction structure of the present embodiment is configured as a film 34. The structure will be described according to the manufacturing method. A diffraction grating forming layer 41 is applied onto a substrate 44 made of a resin film, and a diffraction grating original plate having an uneven relief structure is embossed on the diffraction grating forming layer 41 to reproduce the diffraction grating having the uneven relief structure. A reflective diffraction grating 43 is formed by vapor-depositing a reflective layer 42 on the relief diffraction grating surface, and a film 34 having a layer structure as shown in FIG. 29 is completed.

  Here, the materials constituting the substrate 44, the diffraction grating formation layer 41, and the reflection layer 42 are the same as those in FIGS.

  Here, in FIG. 26 to FIG. 29, an example of a method for producing a diffraction grating original plate for embossing a diffraction grating having an uneven relief structure on the diffraction grating forming layer 41 will be briefly described. To do so, prepare a Cr-plated glass plate, apply an electron beam resist on it, draw a diffraction grating pattern by electron beam drawing, and then develop the electron beam resist to obtain a rectangular wave shape in cross section. An uneven relief structure is obtained.

  An ultraviolet curable resin or a thermosetting resin is applied onto the diffraction grating pattern of the concavo-convex relief structure of such an electron beam resist, and the concavo-convex relief structure is converted into an ultraviolet curable resin or a thermosetting resin by ultraviolet irradiation or heating. By duplicating, a negative version of the diffraction grating pattern for electron beam drawing is obtained. The negative plate is similarly duplicated to obtain a positive plate, or the positive plate obtained by repeating such duplication an even number of times is embossed with the diffraction grating having an uneven relief structure on the diffraction grating forming layer 41. It can be used as a diffraction grating original plate.

  As described above, the display body including the hidden pattern by the light diffraction structure of the present invention and the discriminating tool therefor have been described based on some embodiments. However, the present invention is not limited to these embodiments and can be variously modified. It is.

DESCRIPTION OF SYMBOLS 1 ... Display body containing a hidden pattern 2 ... Partial display surface 3 containing a hidden pattern ... Other partial display surfaces 4 ... Printed matter 5 ... Display unit area 6 ... Stripe pair 6 ₁ ... 1st wavy stripe 6 ₂ ... 2nd wavy line stripe 6 _'1 ... first linear diffraction grating 6' ₂ ... second linear diffraction grating 11 ... non-hidden pattern region 11a ... first non hidden pattern area 11b ... second non hidden pattern region 11 _1, 11a _1, 11b ₁ ... Stripe pairs 11 _1a , 11a _1a , 11b _1a ... first wavy stripes 11 _1b , 11a _1b , 11b _1b ... second wavy stripes 11 ' _1a , 11'a _1a , 11'b _1a ... first linear diffraction grating 11' _1b , 11'a _1b , 11'b _1b ... second linear diffraction grating 12 ... hidden pattern area 12a ... first hidden pattern area 12b ... second hidden pattern area 12 ₁ , 12a ₁ , 12b ₁ ... stripe pairs 12 _1a , 12a _1a , 12b _1a ... 1st wavy stripes 12 _1b , 12a _1b , 12b _1b ... second wavy fringe _{12 '1a, 12'a 1a, 12'b} 1a ... first linear diffraction grating _{12' 1b, 12'a 1b, 12'b} 1b ... second linear diffraction gratings 20, 20 ', 21, 22 ... discriminating tools 20a, 20'a, 21a, 22a ... straight transparent portions 20b, 20'b, 21b, 22b ... straight opaque portions 31 ... transfer foil 32 ... label 33 ... brittle label 34 ... film 41 ... diffraction grating formation Layer 42 ... Reflective layer 43 ... Reflective diffraction grating 44 ... Base material 45 ... Release layer 46 ... Heat seal layer 47 ... Adhesive layer 48 ... Separator (release paper)
49 ... Brittle layer S ... Reference line P ... Pattern P '... Border

Claims (9)

A display surface having a light diffraction structure;
The display surface has different diffraction characteristics, and a plurality of pattern regions having arbitrary outer shapes and inner shapes according to the display pattern are arranged in parallel,
The plurality of pattern areas have a hidden pattern area and a non-hidden pattern area,
The hidden pattern area includes a pair of stripes of the hidden pattern area embedded with a predetermined repetition pitch,
The fringe pair of the hidden pattern area has a first wavy stripe of the hidden pattern area and a second wavy stripe of the hidden pattern area, which are adjacent to each other and parallel, and have different diffraction characteristics,
The first wavy stripe in the hidden pattern region is configured by a first linear diffraction grating in the hidden pattern region in a wavy stripe,
The second wavy stripe in the hidden pattern region is configured by a second linear diffraction grating in the hidden pattern region in a wavy stripe.
The non-hidden pattern area includes a pair of stripes of the non-hidden pattern area embedded at a predetermined repetition pitch,
The first wavy stripe in the non-hidden pattern region is configured by a first linear diffraction grating in the non-hidden pattern region in a wavy stripe.
The second wavy stripe in the non-hidden pattern region is configured by a second linear diffraction grating in the non-hidden pattern region in a wavy stripe.
For the reference line set for the display surface,
The inclination angle of the first linear diffraction grating in the hidden pattern region is equal to the inclination angle of the first linear diffraction grating in the non-hidden pattern region,
The inclination angle of the second linear diffraction grating in the non-hidden pattern region is equal to the inclination angle of the second linear diffraction grating in the non-hidden pattern region,
And,
The display body containing a hidden pattern by an optical diffraction structure, wherein the characteristic of the stripe pair in the hidden pattern region is different from the characteristic of the stripe pair in the non-hidden pattern region. The first wavy stripe in the hidden pattern area and the second wavy stripe in the hidden pattern area, and the first wavy stripe in the non-hidden pattern area and the second wavy stripe in the non-hidden pattern area, respectively. The display body containing a hidden pattern by the light diffraction structure according to claim 1, wherein convex portions and concave portions having a height of 5 to 20% are alternately provided with respect to the repetitive pitch. The first wavy stripe in the hidden pattern area and the second wavy stripe in the hidden pattern area, and the first wavy stripe in the non-hidden pattern area and the second wavy stripe in the non-hidden pattern area, respectively. The display body containing a hidden pattern by the light diffraction structure according to claim 1, wherein convex portions and concave portions of 0.5 to 5 pieces / mm are alternately provided with respect to the repetitive pitch. . For the reference line set for the display surface,
4. The light diffraction according to claim 1, wherein an inclination angle of the stripe pair in the hidden pattern region is different from an inclination angle of the stripe pair in the non-hidden pattern region. 5. A display that contains a hidden pattern of structure. 5. The optical diffraction structure according to claim 1, wherein a repetition pitch of the stripe pair in the hidden pattern region is different from a repetition pitch of the stripe pair in the non-hidden pattern region. A display that contains a hidden pattern. A discrimination tool for a display body containing a hidden pattern by the light diffraction structure according to any one of claims 1 to 5,
An optical diffractive structure having a repeating pattern of parallel linear transparent portions and linear opaque portions having the same inclination angle as the stripe pairs in the hidden pattern region and the same repetition pitch as the stripe pairs in the hidden pattern region Discriminator for a display body that contains a hidden pattern. A discrimination tool for a display body containing a hidden pattern by the light diffraction structure according to any one of claims 1 to 5,
An optical diffraction structure having a repeating pattern of parallel wavy transparent portions and wavy opaque portions having the same inclination angle as the fringe pair in the hidden pattern region and the same repeating pitch as the fringe pair in the hidden pattern region Discriminator for a display body that contains a hidden pattern. The discriminating tool for a display body containing a hidden pattern by the light diffraction structure according to claim 6, wherein a width of the transparent portion is smaller than a width of the opaque portion. A display surface having a light diffraction structure;
The display surface has different diffraction characteristics, and a plurality of pattern regions having arbitrary outer shapes and inner shapes according to the display pattern are arranged in parallel,
The plurality of pattern areas have a hidden pattern area and a non-hidden pattern area,
The hidden pattern area includes a pair of stripes of the hidden pattern area embedded with a predetermined repetition pitch,
The fringe pair of the hidden pattern area has a first wavy stripe of the hidden pattern area and a second wavy stripe of the hidden pattern area, which are adjacent to each other and parallel, and have different diffraction characteristics,
The first wavy stripe in the hidden pattern region is configured by a first linear diffraction grating in the hidden pattern region in a wavy stripe,
The second wavy stripe in the hidden pattern region is configured by a second linear diffraction grating in the hidden pattern region in a wavy stripe.
The non-hidden pattern area includes a pair of stripes of the non-hidden pattern area embedded at a predetermined repetition pitch,
The first wavy stripe in the non-hidden pattern region is configured by a first linear diffraction grating in the non-hidden pattern region in a wavy stripe.
The second wavy stripe in the non-hidden pattern region is configured by a second linear diffraction grating in the non-hidden pattern region in a wavy stripe.
For the reference line set for the display surface,
The inclination angle of the first linear diffraction grating in the hidden pattern region is equal to the inclination angle of the first linear diffraction grating in the non-hidden pattern region,
The inclination angle of the second linear diffraction grating in the non-hidden pattern region is equal to the inclination angle of the second linear diffraction grating in the non-hidden pattern region,
And,
A characteristic of the fringe pair in the hidden pattern region is a display body containing a hidden pattern with a light diffraction structure different from the characteristic of the fringe pair in the non-hidden pattern region;
A discriminator having a repetitive pattern of parallel wavy transparent portions and wavy opaque portions having the same inclination angle as the fringe pair of the hidden pattern region and the same repetitive pitch as the fringe pair of the hidden pattern region;
A display object discrimination system including a hidden pattern by a light diffraction structure.

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