JP5245521B2 - Display body and printed information using the same - Google Patents

Description

  The present invention relates to a display body having an anti-counterfeit function having a concavo-convex structure and an information printed matter using the display body.

It is important that passports, gift certificates, cash cards, etc. are difficult to counterfeit. For this reason, forgery or imitation is difficult for such articles, and seals, labels, and the like are attached so that they can be easily distinguished from counterfeits and imitations.
In addition, recently, counterfeit products such as brand products have been distributed in addition to the above-mentioned products, and the demand for security has increased.

Counterfeiting measures include micro letters, special luminescent ink, watermarks, diffraction gratings and holograms. This counterfeiting measure can be roughly divided into two. One is forgery countermeasures that determine authenticity using a simple device, a measuring device, or the like (see, for example, Patent Document 1). The other is anti-counterfeiting that can be easily determined by the naked eye. The latter anti-counterfeiting does not require any appliances, so anyone can make a true / false determination anywhere and is used especially frequently.
JP 2007-223100 A

Holograms and diffraction gratings form gloss, color shift, and three-dimensional images by controlling the diffracted light with a fine concavo-convex structure. In order to produce these articles, since advanced technology and equipment are required, forgery and imitation are difficult.
However, in recent years, holograms used as a countermeasure against counterfeit products such as brand-name products have become more sophisticated in technology for forging the hologram itself, and holograms based on technologies that have been used in the past can be forged or imitated relatively easily. The function as a prevention effect is weakening. Therefore, a display body that can be clearly differentiated from the conventional technology and is difficult to forge or imitate, and an information printed matter using the display body have been developed.

  The present invention has been made in view of the above points. When the information recording body is observed from the front, the blackness that cannot be seen in the conventional hologram or diffraction grating is expressed. It is an object of the present invention to provide a display body that can display a pattern, characters, and the like only when observed from a predetermined direction with a large tilt, and an information printed matter using the display body.

In order to achieve the above object, the invention of claim 1 is a display body, a light-transmitting substrate having one surface as a light incident surface, and a surface opposite to the light incident surface of the substrate. A relief structure forming layer comprising a relief structure region in which a relief structure is formed by any one or both of a plurality of convex portions and concave portions, and a non-relief structure region in which the relief structure is not formed, and the relief structure forming layer The relief structure has low reflectivity and low scattering for illumination light, and diffracts illumination light incident from an oblique direction with respect to the light incident surface. A diffracted light emitting function for emitting light to the incident surface side, wherein the plurality of convex portions or concave portions has a cross-sectional area in a direction parallel to the opposite surface of the base material of the convex portions or concave portions from the surface. In the depth direction of the tip or recess Is configured to include a sloped surface decreasing in accordance with the said opposite faces and matching surfaces of the base material of the projections or recesses and bottom, and the vertex the depth direction of the distal end of the tip or the recess of the protrusion And an inclination angle of the inclined surface is changed by adjusting an angle of a line connecting the center of the base and the vertex to a perpendicular perpendicular to the opposite surface through the center of the base. The angle with respect to the perpendicular is 3 degrees or more and 30 degrees or less .

According to a second aspect of the present invention, in the display body according to the first aspect, the pitch of the plurality of convex portions or concave portions is 200 nm or more and 350 nm or less, and the height of the convex portion from the opposite surface of the base material or the The depth of the recess from the surface is 200 nm or more and 400 nm or less.
According to a third aspect of the present invention, in the display body according to the first or second aspect, the plurality of convex portions or concave portions are arranged in a matrix at a predetermined pitch along the opposite surface of the base material. Features.

Invention of Claim 4 is information printed matter, Comprising: The display body in any one of Claims 1 thru | or 3 provided in the at least one part area | region of the surface of printed matter base material and the said printed matter base material. It is characterized by providing.

  According to the display body of the present invention, when light is incident on the relief structure forming layer, light other than the diffracted light travels without being reflected or scattered, so that the incident light enters the underlying material (reflective layer). Therefore, if a material having a large complex refractive index (reflection layer) such as a metal is provided in the lower layer of the relief structure, the incident light is absorbed by the layer, so that the light returns to the light incident surface side of the substrate as an observer. Never come. Therefore, it is possible to express blackness that cannot be expressed by a conventional hologram or diffraction grating.

  Further, according to the display body of the present invention, by setting the pitch of the convex portions or concave portions constituting the relief structure to 200 nm or more and 400 nm or less, the diffracted light due to the periodic structure of the convex portions or concave portions is the front direction of the display body, that is, Diffracted light is generated at a large angle with respect to the direction perpendicular to the light incident surface of the base material without being generated in a direction perpendicular to the light incident surface of the base material. Only when observing at an angle, it is possible to display a pattern, characters, symbols, etc. by diffracted light. Further, when the pitch of the concavo-convex structure is in the range of 200 nm to 400 nm, red of visible light is not generated as diffracted light, and only green and blue can be displayed. Further, in the range of 250 nm to 400 nm, red, green, and blue are diffracted. Therefore, by providing regions where the pitches of the convex portions or the concave portions are different, it is possible to determine whether the emitted diffracted light is true or false.

  In addition, according to the display body of the present invention, since it is possible to express blackness that could not be expressed by a hologram or a diffraction grating, a relief structure formed of one or both of a convex portion and a concave portion is formed. By having both the layer and the printing layer with ink showing low reflectivity and low scattering for predetermined illumination light, the display by the two layers is reproduced in the same color in the observation from the front of the display body, When the display body is observed from a predetermined oblique upper side with respect to the light emitting surface, diffracted light is emitted from the relief structure, and no diffracted light is emitted from one printed layer. Authenticity can be determined.

Further, according to the display body of the present invention, a line connecting the center of the base of the convex portion or the concave portion and the vertex of the convex portion or the concave portion passes through the center of the base and is perpendicular to the surface opposite to the light emitting surface of the display body. Since the tilt angle of the inclined surface can be changed by adjusting the angle with respect to the vertical line, it is possible to change the diffraction efficiency, and a relief structure consisting of convex parts or concave parts each having a different tilt angle. By arranging in some areas, a grayscale image can be displayed and the range of expression can be expanded.
Further, according to the display body of the present invention, a line connecting the center of the base of the convex portion or the concave portion and the vertex of the convex portion or the concave portion passes through the center of the base and is perpendicular to the surface opposite to the light emitting surface of the display body. Since the inclination angle of the inclined surface is changed by adjusting the angle with respect to the normal, diffracted light with high diffraction efficiency can be generated for the predetermined incident light, and the predetermined incident light can be generated. Thus, it is possible to display characters and pictures brightly, authenticity can be determined with the naked eye, and security is improved.

Moreover, according to the display body of the present invention, the display body according to any one of claims 1 to 3 can be used as a medium such as a sticker or transfer foil, and can be easily attached to printed information. The anti-counterfeiting effect of the printed information can be improved, and the ease of authenticity determination can be improved.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory diagram showing an example of a display body according to an embodiment of the present invention, and is an enlarged cross-sectional view taken along line AA in FIG.

As shown in FIGS. 1 and 2, the display body 10 is laminated on a light-transmitting base material 12 having one surface as a light incident surface 12a and a surface 12b of the base material 12 opposite to the light incident surface 12a. The light reflecting layer 14 is provided.
On the surface 12b opposite to the light incident surface 12a of the substrate 12, there are formed relief structure regions 11a, 11b, 11c having a relief structure 11 composed of a plurality of recesses 111 and a non-relief structure region 13 having no relief structure, The base material 12 including these relief structure regions 11a, 11b, 11c and the non-relief structure region 13 constitutes a relief structure forming layer.
The relief structure regions 11a, 11b, and 11c have low reflectivity and low scattering property with respect to illumination light incident from the light incident surface 12a of the base material 12, and are incident on the light incident surface 12a from an oblique direction. It has a diffracted light emission function for diffracting (light 16 shown in FIG. 4) and emitting it to the light incident surface 12a side.
The light reflecting layer 14 is laminated on the relief structure forming layer so as to cover all of the relief structure regions 11 a, 11 b, 11 c or at least a part of these and the non-relief structure region 13. In particular, the light reflection layer 14 reflects illumination light incident on the non-relief structure region 13 to the observation region, and perceives it as a bright shining region, unlike the black or dark gray of the relief structure regions 11a, 11b, 11c. It is.

  As shown in FIG. 2, the concave portion 111 of the relief structure region 11a has a sawtooth shape having an inclined surface 11a ′ inclined to the right, and the concave portion 111 of the relief structure region 11b is formed as shown in FIG. As shown in FIG. 2, the concave portion 111 of the relief structure region 11c has a sawtooth shape having an inclined surface 11c ′ inclined in the left direction. .

In addition, the relief structure 11 of the relief structure regions 11a, 11b, and 11c is not limited to the one configured from the concave portion 111, and may be configured from one or both of the concave portion and the convex portion.
In this case, the convex portion or the concave portion has a cross-sectional area of the convex portion or the concave portion in a direction parallel to the surface 12b opposite to the light incident surface 12a of the base material 12 extending from the surface 12b in the depth direction of the convex portion or the concave portion. It is comprised including the inclined surface which decreases according to this.
Moreover, the shape of the convex part or recessed part which comprises the relief structure 11 is not restricted to a sawtooth shape or a triangular wave shape, but a conical shape, a pyramid shape, an elliptical cone shape, a columnar shape, a cylindrical shape, a prism shape, a rectangular tube shape, etc. The concave portions or the convex portions may be arranged in a matrix along the surface 12b opposite to the light incident surface of the substrate 12.

Further, as shown in FIG. 3, a surface that coincides with the surface 12b opposite to the light incident surface 12a of the substrate 12 of the concave portion (or convex portion) 111 constituting the relief structure 11 of the relief structure region 11a is defined as a base A. The tip in the depth direction of the concave portion (or the tip of the convex portion) is defined as a vertex P1, and a line L1 connecting the center P2 of the base A and the vertex P1 passes through the center P2 of the base A to the opposite surface 12b of the substrate 12. The inclination angle of the inclined surface is changed by adjusting the angle with respect to the vertical perpendicular y, and the angle θ with respect to the perpendicular y is set to 30 degrees.
Although not shown in FIG. 3, the inclination direction of the concave portion constituting the relief structure of the relief structure region 11c is opposite to that of the concave portion constituting the relief structure 11 of the relief structure region 11a. Are the same. Further, the pitch H2 of the concave portions (or convex portions) 111 is 300 nm, and the height H1 thereof is 300 nm. Moreover, the recessed part (or convex part) which comprises the relief structure 11 of the relief structure area | region 11b is exhibiting the isosceles triangle as shown with a broken line, The pitch and height are the recessed parts (or convex part) of the relief structure area | region 11a. ) 111 but the angle with respect to the normal y is zero.

When illumination light is incident on the relief structure region having a relief structure composed of a recess (or projection) having such an inclination angle θ from the left side of the relief structure at a predetermined angle, the recess (or projection) is formed at a predetermined position. Diffracted light that is stronger than that having no inclination angle θ can be observed.
Here, the “predetermined angle” means that the light from the illumination light has a steep angle from obliquely upward toward the light incident surface 12 a of the display body 12. The “predetermined position” means a position where the observer can observe the diffracted light.

The representative diffracted light in the first embodiment is first-order diffracted light, and the emission angle β of the first-order diffracted light can be calculated from the following equation (1).
d = λ / (sin α−sin β) (1)
In equation (1), d represents the distance between the concave or convex portions, and λ represents the wavelengths of incident light and diffracted light. Α represents an incident angle.
As is apparent from equation (1), the exit angle β of the first-order diffracted light changes according to the wavelength λ. In other words, the relief structure region composed of the concave portions (or convex portions) has a function as a spectroscope. Therefore, when the illumination light is white light, the color perceived by the observer changes when the observation angle of the relief structure region composed of the concave portions (or convex portions) is changed.

  The relief structure consisting of recesses (or projections) with an inclination angle as described above makes a master plate of a relief structure consisting of recesses (or projections) without an inclination angle by electron beam drawing, and a plate is produced by electroforming. The mold is formed by pressurizing the plate against the resin and releasing the mold while changing the mold release direction.

According to the display body described in the present embodiment, the pitch of one or both of the convex portion and the concave portion is in the range of 200 nm to 350 nm. In the visible wavelength range of 400 to 700 nm, at least the diffracted light of the red component is not observed in the relief structure region composed of the concave portions (or convex portions).
In the above equation (1), at a pitch of 350 nm, in the case of 89 ° illumination light with respect to the light incident surface 12a of the substrate 12, light having a wavelength of 700 nm is diffracted in the 89 ° direction. In addition, with respect to red light, diffracted light having a sufficient intensity is not generated from one or both of the convex portion and the concave portion in the front direction of the display body under all illumination conditions.
On the other hand, at a pitch of 200 nm, in the case of 89 ° illumination light with respect to the light incident surface 12a of the substrate 12, light having a wavelength of 400 nm is diffracted in the 89 ° direction. It turns out that it is.

Therefore, by setting the pitch of either one or both of the convex part and the concave part in the range of 200 nm to 350 nm, it is possible to observe diffracted light other than red from a deep angle in the same manner for illumination light at a deep angle. it can. In addition, diffracted light is not generated under other conditions, and diffracted light is not recognized under general observation conditions.
In order to express the blackness when the information recording body is viewed from the surface, it is desirable that the optimum height difference of the concave portion or convex portion is as deep as at least 200 nm. However, if it exceeds 500 nm, it is difficult to mold the resin. Therefore, the depth of the concave portion or the height of the convex portion is preferably about 200 nm to 400 nm.
Further, the angle θ of the concave portion or the convex portion with respect to the perpendicular y must be 3 to 30 degrees. If an angle of 3 degrees or more is not provided, the diffraction efficiency cannot be increased by 3% or more compared to the case where there is no angle θ. If the angle θ is set to 30 degrees or more, it tends to cause a decrease in blackness and a structural failure, which is not preferable.

FIG. 4 shows diffracted light 17 when incident light 16 is irradiated to a relief structure forming layer having a concavo-convex structure in which a concave portion (or convex portion) 111 is inclined.
As shown in FIG. 4, when the position of the eye 20 where the observer can observe the diffracted light 17 is at a predetermined position shown on the left side of FIG. 4, diffraction is performed by the concave portion (or convex portion) 111 of the relief structure region 11a. The diffracted light 17 can be observed. However, as shown on the right side of FIG. 4, even when incident light 16 that is bilaterally symmetric about the y-axis is irradiated onto the interface 111a that is perpendicular to the concave portion (or convex portion) 111 of the relief structure region 11a, the diffracted light 17a As shown by the broken line, the diffraction efficiency is low, and diffracted light with high diffraction efficiency such as diffracted light 17 at a predetermined position cannot be observed.

  5 irradiates the relief structure region 11b of the relief structure forming layer of the concavo-convex structure in which the concave portion (or convex portion) 111 is not provided with the angle θ with respect to the perpendicular y as shown in FIG. The diffracted light is shown. Since the concave portion (or convex portion) 111 in the relief structure region 11b is symmetric with respect to the y axis, the diffracted light with respect to the incident light 16 is also symmetric with respect to the y axis.

FIG. 6 shows a relief structure having relief structure regions 11a and 11c in which a concave portion (or convex portion) 111 is provided with an inclination angle θ as shown in FIG. 3 and a relief structure region 11b in which an angle θ with respect to the normal y is not provided. Illumination lamps 18 and 19 and observation positions 20 and 21 for illuminating a display body including layers from obliquely above are shown.
As shown in FIG. 6, when the display body is illuminated obliquely from above with the illumination lamp 18, the diffracted light that can be observed at the observation position 20 is weak in the order of the relief structure regions 11a, 11b, and 11c as shown in FIG. Become. Further, the display body is illuminated by the illumination lamp 19 at a predetermined angle, and the diffracted light observed at the predetermined observation position 21 becomes weaker in the order of the relief structure regions 11c, 11b, and 11a as shown in FIG. As is apparent from FIGS. 7 and 8, when the concave portion (or convex portion) 111 has an angle θ with respect to the normal y as shown in FIG. 3, the diffraction efficiency of the emitted diffracted light changes.

By forming the relief structure area having an angle θ with respect to the normal y as shown in FIG. 3 in each of the concave portions (or convex portions) 111 as described above, it is possible to display shading on the pattern and determine the authenticity. Can be easily done.
In addition, by using the display body 10 as a medium such as a sticker or transfer foil and easily attaching it to an information printed matter or the like, it is possible to improve the forgery prevention effect of the attached information printed matter and the ease of authenticity determination.

(Embodiment 2)
FIG. 9 is an explanatory diagram showing an example of a display body according to Embodiment 2 of the present invention.
The display body 10 shown in FIG. 9 includes relief structure regions 22, 23, 24, 25, and 26 having a concavo-convex structure and a non-relief structure region 27 having no concavo-convex structure.
In the relief structure regions 22, 23, and 24, concave portions or convex portions such as a conical shape, a pyramid shape, an elliptical pyramid shape, a columnar shape, a cylindrical shape, a prism shape, and a rectangular tube shape are arranged in a matrix in the plane direction. . Further, the relief structure region 25 has a conical shape, a pyramid shape, an elliptical pyramid shape, a columnar shape, a cylindrical shape, a prismatic shape, a rectangular tube shape, or the like, as shown in FIG. A line L1 connecting the center P2 of the base A and the vertex P1 has an angle of 30 degrees. The relief structure area 26 has an angle of 30 degrees on the opposite side to the relief structure area 25. The pitch H2 of the relief structure regions 22 to 26 is 300 nm, and the height H1 is 300 nm.

When the display body 10 is illuminated with illumination light from the vertical direction and observed from the front of the display body 10, the relief structure regions 22 to 26 are black because of the low reflection structure, and the non-relief structure region 27 is not a low reflection structure. Therefore, reflection by the reflection layer can be observed and it looks bright.
Further, when the display body 10 is illuminated from the left side at a predetermined angle and observed at a predetermined position, diffracted light can be seen in the relief structure region. Since the inclination angles are different among the relief structure regions 22, 25, and 26, the diffracted light is observed brightly in the order of the relief structure regions 22, 25, and 26. In the non-relief structure region 27, diffracted light cannot be observed.
In addition, when the display body 10 is illuminated from the right side at a predetermined angle and observed from a predetermined position, the relief structure areas appear brighter in the order of the relief structure areas 26, 23, and 25.

  Such a display body can be used as a medium such as a sticker or transfer foil, and can be easily attached to an information printed matter, etc., improving the forgery prevention effect of the attached information printed matter, and improving the ease of authenticity determination. Is possible.

The schematic plan view which shows an example of the display body concerning this invention. The expanded sectional view which follows the AA line of the display body shown in FIG. Explanatory drawing which showed the inclination-angle of the recessed part (or convex part) of the relief structure in this Embodiment. Schematic for description which showed a mode that the relief structure area | region in this Embodiment inject | emitted diffracted light. Schematic for description which showed a mode that the non-relief structure area | region in this Embodiment inject | emits diffracted light. Explanatory drawing which showed the incident light and observation position of a different angle on the display body in this Embodiment. FIG. 7 is an explanatory diagram showing diffracted light when the display body shown in FIG. 6 is illuminated by a left illumination lamp 18 and observed from a position 20 on the left side. Explanatory drawing which showed the diffracted light at the time of illuminating the display body shown in FIG. 6 with the illumination lamp 19 on the right side, and observing from the position 21 on the right side. Explanatory drawing which showed an example of the structure of the relief structure formation layer in embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Display body, 11a, 11b, 11c ... Relief structure area | region, 111 ... Recessed part (or convex part), 12 ... Light transmissive base material, 13 ... Non-relief structure area | region, 14 ... Light reflection layer, (theta) ... Inclination angle, 16 ... incident light, 17 ... diffracted light, 18, 19, 28 ... illuminating lamp, 20,21 ... eye, 22,23,24,25,26 ... relief structure region, 27 ... non-relief structure region.

Claims (4)

A light-transmitting substrate having one surface as a light incident surface;
From a relief structure region in which a relief structure is formed by one or both of a plurality of convex portions and concave portions on a part of a surface opposite to the light incident surface of the substrate, and a non-relief structure region in which the relief structure is not formed A relief structure forming layer,
A light reflecting layer laminated on the relief structure forming layer,
The relief structure has a low-reflectivity and low-scattering property for illumination light, and has a diffracted light emission function for diffracting illumination light incident from an oblique direction with respect to the light incident surface and emitting it to the light incident surface side. Have
The plurality of convex portions or concave portions reduce a cross-sectional area of the convex portion or concave portion in a direction parallel to the opposite surface of the base material from the surface toward the tip of the convex portion or the depth direction of the concave portion. Comprising an inclined surface ,
A surface that coincides with the opposite surface of the base of the convex portion or the concave portion is a base, and a tip of the convex portion or a tip in the depth direction of the concave portion is a vertex, and the center of the base and the vertex are The connecting line is configured to change the inclination angle of the inclined surface by adjusting the angle with respect to a perpendicular perpendicular to the opposite surface through the center of the base,
An angle with respect to the perpendicular is not less than 3 degrees and not more than 30 degrees,
A display body characterized by that.   The pitch of the plurality of protrusions or recesses is 200 nm or more and 350 nm or less, and the height of the protrusions from the opposite surface of the base material or the depth of the recesses from the surface is 200 nm or more and 400 nm or less. 2. The display body according to claim 1, wherein: Display body according to claim 1 or 2 wherein the plurality of projections or recesses is characterized in that it is arranged in a matrix at a predetermined pitch along the opposite surface of the substrate. A printed material base;
The display body according to any one of claims 1 to 3 , which is provided in at least a partial region of the surface of the printed material base,
Information printed matter characterized by that.

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