JP2017111255A - Display body, and observation method of display body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display body capable of more effectively displaying an enlarged image of a pattern.SOLUTION: A frequency of an unevenness in a second unevenness surface S2 which a reflection suppression part 12 includes in a display body 10 has a size for suppressing a reflection of light incident from a front face side and the reflection of light incident from a rear face side with respect to the reflection suppression part 12. The reflection suppression part 12 has characteristics for absorbing the light incident from the front face side and the light incident from the rear face side. From among the front face side and the rear face side, one is the incident side, and a side other than the incident side is a non-incident side. A pattern element 11 is constituted of an uneven structure which is a dielectric body and a metallic layer which covers at least a part of the front face side in the uneven structure, and absorbs a part of light from the incident side and emits the light having a color different from the light from the incident side to the non-incident side, and forms a pattern by the light from the rear face side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display body that displays information externally, and a display body observation method.

  There is known a display body including a micro pattern such as a character or a pattern and a micro lens array overlapping the micro pattern. In this display body, the pitch of the microlenses is slightly different from the pitch of the micropatterns. Therefore, when the display body is viewed from the direction facing the microlens, the position of the micropattern enlarged and displayed through the microlens However, there is a slight difference between the left and right eyes of the observer. The effect of visually recognizing the micro pattern as a stereoscopic image by parallax with both eyes is the moire effect, and the display body displays the micro pattern as an enlarged image and a stereoscopic image by the moire effect.

  In such a display body, the light incident on the micropattern through the microlens is reflected by the micropattern, and the reflected light is emitted outside the display body through the microlens. And when the light inject | emitted outside the display body enters an observer's eyes, the enlarged image of a micro pattern is visually recognized by the observer (for example, refer patent document 1).

Japanese Patent No. 5527969

By the way, since an observer of an object generally recognizes the object by light reflected on the object, an observer of the display body is likely to notice an enlarged image formed by reflected light in the micropattern. Therefore, the display body is required to display an enlarged image more effectively.
An object of this invention is to provide the display body which can display the image in which the pattern was expanded more effectively, and the observation method of a display body.

  A display body for solving the above-described problems includes a pattern layer configured by a plurality of pattern elements each forming a pattern by transmission of light, and a reflection suppressing unit that fills between the adjacent pattern elements, and Are a plurality of lenses having focal points on different pattern elements, and the plurality of lenses includes the plurality of lenses that enlarge each pattern to form one image. The side where the lens is positioned with respect to the pattern element is the front side, and the side opposite to the side where the lens is positioned with respect to the pattern element is the back side. The surface of the pattern layer is composed of a first uneven surface that is the surface of each pattern element and a second uneven surface that is the surface of the reflection suppressing portion. The period of the unevenness on the second uneven surface has a size that suppresses reflection of light incident from the front side and reflection of light incident from the back side with respect to the reflection suppression unit, and the reflection suppression unit Has a characteristic of absorbing light incident from the front side and light incident from the back side. One of the front side and the back side is an incident side, and other than the incident side is a non-incident side. The pattern element includes a concavo-convex structure portion that is a dielectric and a metal layer that covers at least a part of the surface of the concavo-convex structure portion, absorbs a part of light from the incident side, and Light having a color different from the light from the side is emitted to the non-incident side, and the pattern is formed by the light from the back side.

  According to the above configuration, since the reflection suppressing portion and the pattern element absorb light from the front side, the display body forms one image with low brightness on the front side. On the other hand, while the reflection suppressing unit absorbs light incident from the back side, the pattern element forms a pattern with light having a color different from the light incident from the back side. A low image and an enlarged image of the pattern are formed facing the front side. Thus, since the display body forms an enlarged image only by the light incident from the back side, the display body can display the enlarged image more effectively.

  In the display body, each lens has an optical axis extending along a direction in which the lens and the pattern element overlap, and has a refractive index distribution along a radial direction of the optical axis, and the pattern layer, It may be a radial type gradient index lens having a flat surface as a surface opposite to the opposing surface.

  According to the above configuration, the surface through which light that has passed through the pattern element and the lens and that contributes to the formation of an enlarged image is emitted is a flat surface. Therefore, compared with the configuration in which the lens has a curved surface as the light emission surface, the transmitted light is less likely to be scattered when emitted from the lens. Therefore, the display body can display a clearer image.

The display body may further include a reflection suppressing layer that has light transmittance and covers a surface of each lens opposite to the surface facing the pattern layer.
According to the said structure, compared with the structure which does not have a reflection suppression layer, the light reflected in the surface which inject | emits transmitted light among lenses is mixed with the light which permeate | transmitted the pattern layer and the lens. Therefore, the enlarged image displayed by the display body becomes clearer.

The display body may further include a protective layer that has light transmittance and covers the surface of the pattern layer to fill the unevenness on the surface of the pattern layer.
According to the above configuration, since the lens is not in direct contact with the pattern layer, the shape of the unevenness constituting the surface of the pattern layer facing the lens is unlikely to change.

A display body observation method for solving the above-mentioned problem, wherein the display body is the display body, and the pattern layer and the lens are irradiated with light from the back side. And observing the light transmitted through the front side.
According to the said structure, when light is irradiated from the back side with respect to a pattern layer, the image in which the pattern was expanded can be observed.

  According to the present invention, an image with an enlarged pattern can be displayed more effectively. Further, according to the display body observation method, it is possible to observe an image expressed more effectively.

The disassembled perspective view which shows the perspective structure which decomposed | disassembled the element which comprises the display body in one Embodiment which actualized the display body. The fragmentary sectional view which shows the partial cross section structure of a display body. Sectional drawing which shows the cross-section in an example of the lens with which a display body is provided. Sectional drawing which shows the cross-section in an example of the lens with which a display body is provided. The figure is a partial perspective structure of the pattern element, and a part thereof is broken. The figure which is a partial perspective structure of a reflection suppression part, and one part was fractured | ruptured. The action figure for demonstrating the effect | action of a display body. The action figure for demonstrating the effect | action of a display body. The fragmentary sectional view which shows the partial cross section structure of the display body in a modification. The fragmentary sectional view which shows the partial cross section structure of the display body in a modification. The effect | action figure for demonstrating the effect | action of the display body in a modification. The effect | action figure for demonstrating the effect | action of the display body in a modification.

  With reference to FIG. 1 to FIG. 8, an embodiment in which the display body of the present invention is embodied will be described. Below, the structure of a display body and the effect | action of a display body are demonstrated in order.

[Configuration of the display body]
The configuration of the display body will be described with reference to FIGS. Below, after explaining the whole structure of a display body, the structure of the lens with which a display body is equipped, the structure of a pattern element, the structure of a reflection suppression part, and the formation material of a pattern element and a reflection suppression part are demonstrated in order. In FIG. 1, in order to easily distinguish the pattern element from the reflection suppression unit, dots are added to the reflection suppression unit.

  As shown in FIG. 1, the display body 10 includes a plurality of pattern elements 11, a pattern layer 13 including a reflection suppressing portion 12 that fills the space between adjacent pattern elements 11, and a plurality of lenses 14. The plurality of lenses 14 enlarge each pattern to form one image.

  Each pattern element 11 forms a pattern by light transmission, and each lens 14 has a focus on a separate pattern element 11. In the display body 10, the side where the lens 14 is positioned with respect to the pattern element 11 is the front side, and the side opposite to the side where the lens 14 is positioned with respect to the pattern element 11 is the back side.

  The surface 13s of the pattern layer 13 includes a first uneven surface S1 that is the surface of each pattern element 11 and a second uneven surface S2 that is the surface of the reflection suppressing portion 12. The period of the unevenness on the second uneven surface S2 has such a magnitude as to suppress the reflection of light incident from the front side and the reflection of light incident from the back side with respect to the reflection suppressing unit 12. The reflection suppressing unit 12 has a characteristic of absorbing light incident from the front side and light incident from the back side.

  One of the front side and the back side is the incident side, and the other side is the non-incident side. The pattern element 11 includes a concavo-convex structure portion that is a dielectric and a metal layer that covers at least part of the surface of the concavo-convex structure portion. The pattern element 11 absorbs a part of light from the incident side and emits light having a color different from that from the incident side to the non-incident side. The pattern element 11 forms a pattern by light from the back side.

  In the display body 10, since the reflection suppressing unit 12 and the pattern element 11 absorb light from the front side, the display body 10 forms one image with low brightness on the front side. On the other hand, since the reflection suppressing unit 12 absorbs light incident from the back side, the pattern element 11 forms a pattern with light having a color different from the light incident from the back side. Then, an image with low brightness and an image with an enlarged pattern are formed facing the front side. Thus, since the display body 10 forms an image enlarged only by the light incident from the back side, the display body 10 can display the enlarged image more effectively.

  The plurality of lenses 14 constitute a lens array layer 16 together with a support portion 15 having a single layer shape. In the lens array layer 16, the surface facing the pattern layer 13 is the back surface 16r, the surface opposite to the back surface 16r, and the surface including the surface of each lens 14 is the surface 16s.

  The surface 13 s of the pattern layer 13 is a surface facing the back surface 16 r of the lens array layer 16 among the surfaces of the pattern layer 13, and the surface opposite to the surface 13 s is the back surface 13 r of the pattern layer 13.

  Of the pattern layer 13, each pattern element 11 excites surface plasmons on the metal layer by light incident from the front side, that is, light incident on the pattern element 11 through the lens array layer 16, and light incident from the front side. To absorb some of it. Thereby, the pattern element 11 inject | emits the light which has a color different from the light which injected from the surface 13s, for example, the light which has a predetermined chromatic color, to the back side.

  Each pattern element 11 excites surface plasmons on the metal layer by light incident from the back side, that is, light incident from the back surface 13r of the pattern layer 13, and absorbs part of the light incident from the back side. Thereby, the pattern element 11 inject | emits the light which has a color different from the light which injected from the back surface 13r, for example, the light which has a predetermined chromatic color, to the front side.

  The pattern element 11 forms a pattern by transmitted light emitted to the front side. The pattern element 11 has a shape expressing an asterisk in a plan view facing the surface 13s. Each pattern element 11 forms one pattern, and the pattern is an image expressing an asterisk having a predetermined color.

  The pattern is not limited to an image of a symbol such as an asterisk, but may be an image of a character such as a character, a number, or a pattern or pattern, or two or more of a symbol, a character, a number, and a shape. It may be an image of a combination of these.

  The direction parallel to the thickness direction of the display body 10 is the Z direction, one direction orthogonal to the Z direction is the X direction, and the direction orthogonal to the X direction is the Y direction. The back surface 13r of the pattern layer 13 is a flat surface along the XY plane.

  The pattern elements 11 are arranged at a pattern period P1 which is a predetermined period along the X direction, and the pattern elements 11 are arranged in a hexagonal lattice pattern on one plane along the XY plane. On the other hand, the lenses 14 are arranged in a hexagonal lattice pattern on one plane along the XY plane at a lens period P2 having a predetermined period along the X direction and different from the pattern period P1. Yes.

  Although the pattern period P1 and the lens period P2 are different values, each of the pattern period P1 and the lens period P2 is a value in which one lens 14 overlaps one pattern element 11 in the Z direction. As described above, since the difference between the pattern period P1 and the lens period P2 is a slight difference, the plurality of lenses 14 is a single grouped part of the enlarged image of the pattern formed by each pattern element 11 due to the moire effect. An enlarged image can be formed. The display body 10 may be configured to display one enlarged image, or may be configured to display a plurality of enlarged images.

  Each of the pattern elements 11 and the lenses 14 may be arranged in a tetragonal lattice shape and a trigonal lattice shape as long as they are arranged in accordance with the same rule, and are arranged following a predetermined number sequence such as a Fibonacci number sequence. You may go out.

  The pattern period P1 and the lens period P2 are not limited to a configuration having a slight difference. In a plan view facing the surface 16s of the lens array layer 16, the direction in which the plurality of lenses 14 are arranged and the plurality of pattern elements 11 are A moiré effect can also be exhibited by a configuration in which the direction of alignment intersects at a minute angle.

[Lens configuration]
The configuration of the lens 14 will be described with reference to FIGS. In FIG. 2, dots are added to the pattern elements for the sake of easy understanding of one lens and the position of the pattern element overlapping the lens in the Z direction. In FIG. 4, dots are added to the lens in order to show the refractive index distribution in the lens. In addition, the dot which has a high density | concentration is attached | subjected to the part with a higher refractive index among lenses.

  As shown in FIG. 2, the lens array layer 16 overlaps the pattern layer 13 with the front surface 13 s of the pattern layer 13 and the back surface 16 r of the lens array layer 16 in contact with each other. Each lens 14 is a convex lens protruding in a direction away from the back surface 16 r of the lens array layer 16, and each lens 14 has a focus on different pattern elements 11 in the pattern layer 13.

  For example, the shape of each lens 14 is configured to have a focus in the vicinity of the back surface 16r of the lens array layer 16, that is, in the vicinity of the first uneven surface S1 in the pattern element 11 in the surface 13s of the pattern layer 13. Yes. The shape of each lens 14 is 90 ° as an angle formed between the plane including the direction of the observer's line of sight and the XY plane, that is, a range of a predetermined angle including an angle when the display body 10 is viewed from the front. Thus, the pattern element 11 is configured to have a focal point in the vicinity of the first uneven surface S1.

  The shape of each lens 14 is determined when the display body 10 is obliquely viewed, that is, when the angle formed by the plane including the direction of the line of sight of the observer and the XY plane is a predetermined angle different from 90 °. Alternatively, the pattern element 11 may be configured to have a focal point in the vicinity of the first uneven surface S1.

  Each lens 14 is an aspheric lens, but may be a spherical lens. If each lens 14 is an aspheric lens, the display 10 can form a higher quality image with reduced blurring and blurring. If each lens 14 is a spherical lens, the workability of the lens array layer 16 is enhanced.

  As shown in FIG. 3, each lens 14A is not limited to the convex lens described above, but may be a convex Fresnel lens. Even if each lens 14A included in the lens array layer 16A is a convex Fresnel lens, if the lenses 14A are arranged in the lens period P2, an image with an enlarged pattern can be formed by the moire effect.

  As shown in FIG. 4, each lens 14 </ b> B may be a gradient index lens. Each lens 14B has an optical axis A extending along the direction in which the lens 14B and the pattern element 11 overlap, and has a refractive index distribution along the radial direction of the optical axis A. In the lens 14B, the surface opposite to the surface facing the pattern layer 13 is a flat surface, and each lens 14B is a radial type gradient index lens.

  The refractive index of the lens 14B decreases as the distance from the optical axis in the radial direction increases. The lens array layer 16B includes only a plurality of lenses 14B, and both the front surface 16s and the back surface 16r of the lens array layer 16B are flat surfaces.

  In the display body 10 provided with such a lens array layer 16B, the surface through which the light transmitted through the pattern element 11 and the lens 14B and contributing to the formation of an enlarged image is emitted is a flat surface. Therefore, it is less likely to be scattered when the light is emitted from the lens 14B, compared to a configuration in which the lens has a curved surface as the light emission surface. Therefore, the display body 10 can display a clearer image.

  Even if the lens 14B is a gradient index lens, if the lenses 14B are arranged in the lens period P2, an image with an enlarged pattern can be formed by the moire effect.

  The material for forming the lens array layers 16, 16 </ b> A, and 16 </ b> B may be a material having transparency to visible light, and may be an inorganic material or an organic material. Examples of the inorganic material that transmits visible light include glass, quartz, titanium oxide, and magnesium fluoride. Examples of organic materials that transmit visible light include acrylic resins such as urethane-modified acrylic resins and epoxy-modified acrylic resins, and various synthetic resins such as epoxy resins.

  The lens is not limited to a convex lens and a convex Fresnel lens, that is, a convex lens, but may be a concave lens and a concave Fresnel lens, that is, a concave lens. The lens may be a convex lens and a concave lens. A combination of these may be used. When the lens is a radial type gradient index lens, the refractive index of the lens may increase as the distance from the optical axis in the radial direction increases.

[Configuration of pattern elements]
With reference to FIG. 5, the configuration of the pattern elements will be described in more detail.
As shown in FIG. 5, the pattern element 11 includes an uneven structure portion 21 and a metal layer 22 that covers a part of the uneven structure portion 21. The pattern element 11 includes a plasmon structure including an interface 23 between the concavo-convex structure portion 21 and the metal layer 22. The plasmon structure receives incident light incident on the surface 13s of the pattern layer 13 at the interface 23 and excites surface plasmons on the metal layer 22, thereby absorbing light of a specific wavelength included in the incident light, The incident light is changed to transmitted light having a color different from that of the incident light.

  The plasmon structure receives incident light incident on the back surface 13r of the pattern layer 13 at the interface 23 and excites surface plasmons on the metal layer 22, thereby absorbing light of a specific wavelength included in the incident light. Thus, the incident light is changed to transmitted light having a color different from that of the incident light.

  The concavo-convex structure portion 21 includes a plate-like portion 31 having a surface 31 s that is one surface and a back surface 31 r that is a surface opposite to the surface 31 s, and a plurality of protrusions protruding from the surface 31 s of the plate-like portion 31. Part 32. Of each convex part 32, the surface away from the surface 31s is the top surface 32a, and the surface connected to the surface 31s is the side surface 32b.

  The plurality of top surfaces 32a are included in a virtual plane S that is one of the XY planes, and the surface 31s and the virtual plane S are substantially parallel to each other. The distance D between the surface 31s and the virtual plane S, in other words, the height of the convex portion 32 is preferably 30 nm or more and 500 nm or less.

  Each convex portion 32 has a quadrangular prism shape, but may have a polygonal column shape other than a quadrangular column shape such as a triangular column shape or a pentagonal column shape, or may have a cylindrical shape or an elliptic column shape. Alternatively, it may have a cone shape such as a cone shape or a polygonal cone shape. When each convex part 32 has a polygonal prism shape, each corner of the convex part 32 may have a curvature.

  The side surface 32b of each convex part 32 may be a stepped surface. When the convex portion 32 has a shape in which the width of the convex portion 32 along the X direction or the Y direction increases from the top surface 32a toward the surface 31s for each step, of the side surface 32b, the virtual plane S and A metal layer 22 may be located on each of the substantially parallel surfaces.

  The metal layer 22 is located on all the portions of the surface 31 s of the plate-like portion 31 that are not covered with the convex portions 32 and the top surface 32 a of each convex portion 32. In the pattern element 11, the side surface 32 b of each convex portion 32 and the surface 22 s of the metal layer 22 are part of the first uneven surface S 1 of the pattern element 11, that is, the surface 13 s of the pattern layer 13. Further, the back surface 31 r of the plate-like portion 31 is a part of the back surface 13 r of the pattern layer 13.

In addition, the metal layer 22 may be located only on the surface 31s of the plate-like portion 31, or may be located only on each top surface 32a. Or the metal layer 22 may be located in a part of surface 31s, and may be located only in the one part top surface 32a in the some top surface 32a. Alternatively, the metal layer 22 may cover the entire surface of the concavo-convex structure portion 21.
The thickness M of the metal layer 22 is, for example, 20 nm to 100 nm, and preferably 40 nm to 60 nm.

  The plurality of convex portions 32 are arranged at equal intervals along the X direction and are arranged at equal intervals along the Y direction. That is, the plurality of convex portions 32 are arranged in a tetragonal lattice pattern on the surface 31 s of the plate-like portion 31. The distance between the two convex portions 32 adjacent to each other in the X direction is a convex portion period P3. Further, the distance between the two convex portions 32 adjacent to each other in the Y direction is also the convex portion period P3. The convex period P3 is smaller than the visible light region, preferably 100 nm or more and 600 nm or less, and more preferably 100 nm or more and 400 nm or less.

  As described above, the height of the convex portion 32 is preferably 30 nm or more and 500 nm or less. If the height of the convex portion 32 is 30 nm or more, the surface plasmon easily absorbs light of a specific wavelength in incident light and easily changes to transmitted light having a color different from the incident light. On the other hand, if the height of the convex portion 32 is 500 nm or less, the convex portion 32 can be easily formed as compared with the configuration in which the height of the convex portion 32 is larger.

  The plurality of convex portions 32 may be arranged in a three-way lattice shape or a hexagonal lattice shape. The configuration in which the plurality of convex portions 32 are arranged in a three-way lattice shape or a hexagonal lattice shape is included in the distance between the adjacent convex portions 32 as compared to the configuration in which the plurality of convex portions 32 are arranged in a tetragonal lattice shape. The number of values that are different from each other. Therefore, in the pattern element 11, the state of the surface plasmon formed at the interface 23 can be changed by changing the state in which the plurality of convex portions 32 are arranged.

  Further, when the plurality of convex portions 32 are arranged in a hexagonal lattice, the distance between one convex portion 32 and each of the six convex portions 32 positioned around the one convex portion 32 is equal to each other. That is, each convex part 32 and the six convex parts 32 located around each convex part 32 are arranged in the same convex part period P3. In this way, when the plurality of convex portions 32 are arranged in a hexagonal lattice pattern, all the convex portions 32 are arranged at equal intervals, so that the surface plasmon states formed at the interface 23 are substantially equal to each other. Therefore, it is easier to adjust the color of the transmitted light of each pattern element 11 as compared with the configuration in which the plurality of convex portions 32 are arranged in a tetragonal lattice pattern.

  The ratio of the length of the convex part 32 along the X direction or the Y direction with respect to the convex part period P3 is the fill factor. In the pattern element 11, on the premise that the formation material of the concavo-convex structure portion 21 is the same and the convex portion period P <b> 3 is the same, the color of light emitted from the plasmon structure changes due to the change of the fill factor.

  As described above, the pattern element 11 absorbs light having a specific wavelength among light incident on the pattern element 11 and transmits light having a specific wavelength. As a result, the pattern element 11 has an image with low brightness on the light incident side, for example, black or dark gray, in order to prevent light from being reflected on the light incident side. The image formed by the light having a specific wavelength is displayed on the non-incident side of the light. Then, when the light incident side is the back side with respect to the pattern layer 13 and the non-incident side is the front side with respect to the pattern layer 13, the pattern element 11 forms an image that becomes a pattern to be enlarged by the lens 14 on the front side. To do.

[Configuration of reflection suppression unit]
With reference to FIG. 6, the configuration of the reflection suppressing unit will be described in more detail.
As shown in FIG. 6, the reflection suppressing portion 12 includes a concavo-convex structure portion 41 and a metal layer 42 that covers the entire concavo-convex structure portion 41. The surface of the metal layer 42 is the second uneven surface S2 of the reflection suppressing unit 12, and the metal layer 42 has a characteristic of absorbing light incident on the reflection suppressing unit 12 from the front side and light incident from the back side. ing.

  The concavo-convex structure portion 41 has a plate-like portion 51, and one surface of the plate-like portion 51 is a front surface 51s, and a surface opposite to the front surface 51s is a back surface 51r. The back surface 51 r of the plate-like portion 51 is a part of the back surface 13 r of the pattern layer 13. The concavo-convex structure portion 41 has a plurality of convex portions 52 protruding from the surface 51 s of the plate-like portion 51 and a plurality of concave portions 53 recessed from the surface 51 s of the plate-like portion 51 toward the back surface 51 r.

  Each of the plurality of convex portions 52 has a semi-ellipsoidal shape, and has a shape in which the length along the Z direction is larger than the length along the X direction. Each of the plurality of recesses 53 is partitioned by a curved surface, and in the cross section along the thickness direction of the plate-like portion 51, the surface that partitions the recess 53 has a semi-elliptical arc shape. The convex portion 52 may have a quadrangular prism shape or a polygonal column shape other than the quadrangular prism shape, and the surface defining the concave portion 53 may be a cylindrical surface or a polygonal cylindrical surface.

  On the surface 51 s of the plate-like part 51, the convex parts 52 and the concave parts 53 are alternately arranged along the X direction and are arranged alternately along the Y direction. In the two convex portions 52 adjacent to each other in the X direction, the distance between the top portions is constant, and the distance between the top portions is the unevenness period P4. That is, one convex portion 52 and one concave portion 53 arranged along the X direction are arranged at the concave / convex period P4. The uneven period P4 is smaller than the visible light region, preferably 200 nm or more and 600 nm or less, and more preferably 200 nm or more and 400 nm or less.

  The period of the irregularities on the second irregular surface S2 is the period of irregularities on the surface of the metal layer 42 covering the convex part 52 and the concave part 53 arranged in the irregular period P4. The value is substantially equal to the period P4. In addition, the period of the unevenness of the second uneven surface S2 is smaller than the uneven period P4 by the amount that the metal layer 42 covers the uneven structure portion 41.

  The plurality of convex portions 52 are arranged at equal intervals along a direction intersecting at about 45 ° with respect to the X direction, and the plurality of concave portions 53 are equal along the same direction as the direction in which the convex portions 52 are arranged. They are lined up at intervals. That is, the alternately arranged convex portions 52 and concave portions 53 are arranged in a tetragonal lattice shape. It should be noted that the alternately arranged convex portions 52 and concave portions 53 may be arranged in a three-way lattice shape or a hexagonal lattice shape. As described above, according to the configuration in which the convex portions 52 and the concave portions 53 are regularly arranged, the convex portions 52 and the concave portions 53 having the same shape are formed at equal intervals, so that the workability of the concave-convex structure portion 41 is improved.

  Moreover, if the average value in the space | interval between the convex part 52 and the recessed part 53 which mutually adjoins the convex part 52 and the recessed part 53 is smaller than a visible light area | region, in other words, in the surface 51s of the plate-shaped part 51, in other words. They may be arranged aperiodically. If the convex portions 52 and the concave portions 53 are irregularly arranged, it is possible to suppress the generation of diffracted light due to the periodic concavo-convex structure in the concavo-convex structure portion 41.

  Since the uneven period P4 is smaller than the visible light region, the reflection suppressing unit 12 transmits a part of the light incident from the front side to the second uneven surface S2 which is the surface of the metal layer. That is, the reflection suppressing unit 12 decreases the reflectance of light incident on the reflection suppressing unit 12.

  When visible light is incident on the reflection suppressing unit 12 from the front side, the refractive index of the portion where the visible light is incident continuously changes with respect to the visible light. Therefore, the impedance deviation that normally occurs between the object and the air does not occur at the interface between the reflection suppressing unit 12 and the air, and as a result, visible light is reflected on the second uneven surface S2 of the reflection suppressing unit 12. It can be suppressed. As a result, the reflectance of the light incident on the reflection suppressing unit 12 is reduced. And the light which permeate | transmitted 2nd uneven surface S2 injects into the metal layer 22, and most of the incident light is absorbed by the metal layer 22. FIG.

  In the reflection suppression unit 12, part of the light incident on the surface 13 s of the pattern layer 13 is reflected at the interface between the air and the metal layer 42, and part of the light that is not reflected is absorbed by the metal layer 42. The The light reflected at the interface between the air and the metal layer 42 enters the metal layer 42 again, and part of the light is again absorbed by the metal layer 42. By such absorption by the multiple metal layers 42, reflection of light on the front side and transmission of light on the back side are suppressed.

  Therefore, when light is incident on the surface 13s of the pattern layer 13 from the front side, the reflection suppressing unit 12 displays an image having black or dark gray on the front side.

  Further, even when light is incident on the back surface 13r of the pattern layer 13 from the back side, the reflection suppressing portion 12 is a part of the light incident from the back side and is reflected at the interface between the concavo-convex structure portion 41 and the metal layer 42. The incident light is incident on the metal layer 42 again, and a portion of the incident light is absorbed. Accordingly, a part of the light transmitted from the back side and transmitted through the metal layer 42 is absorbed by the metal layer 42.

  Therefore, even when light enters from the back side of the pattern layer 13, the reflection suppressing unit 12 displays an image having black or dark gray on the back side.

  Note that the concavo-convex structure portion 41 may be configured to include only the plate-like portion 51 and the plurality of convex portions 52 or only the plate-like portion 51 and the plurality of concave portions 53. Even in such a configuration, if the plurality of convex portions 52 or the plurality of concave portions 53 are arranged so as to satisfy the above-described arrangement state and period, the plurality of convex portions 52 and the plurality of concave portions 53 are provided. An effect equivalent to that of the configuration can be obtained.

  The metal layer 42 covers the entire concavo-convex structure portion 41. The thickness of the metal layer 42 is preferably 20 nm or more and 100 nm or less in order to cause light absorption in the reflection suppressing unit 12.

  The metal layer 42 is a convex portion among a part of the surface of the concavo-convex structure portion 41, that is, the entire surface of the convex portion 52, the entire surface defining the concave portion 53, and the surface 51 s of the plate-like portion 51. It may be located only in a part of the portion that is not covered with 52 and in which the recess 53 is not formed. In such a configuration, the surface of the metal layer 42 and the surface of the uneven structure portion 41 that is not covered with the metal layer 42 are the second uneven surface S2 of the reflection suppressing portion 12. However, in order to increase the efficiency with which the metal layer 42 absorbs light, the entire concavo-convex structure portion 41 is preferably covered with the metal layer 42.

[Material for forming pattern element and reflection suppressing portion]
It is preferable that the concavo-convex structure portion 21 included in the pattern element 11 and the concavo-convex structure portion 41 of the reflection suppressing portion 12 are an integrated body having the same forming material. Moreover, it is preferable that the formation material of the metal layer 22 in the pattern element 11 and the formation material of the metal layer 42 in the reflection suppressing portion 12 are the same material.

  If the concavo-convex structure portion 21 of the pattern element 11 and the concavo-convex structure portion 41 of the reflection suppressing portion 12 are an integrated body having the same forming material, the concavo-convex structure portions 21 and 41 can be formed simultaneously. Further, if the material for forming the metal layer 22 in the pattern element 11 and the material for forming the metal layer 42 in the reflection suppressing portion 12 are the same material, the metal layers 22 and 42 can be formed simultaneously.

  The formation material of the concavo-convex structure portions 21 and 41 is, for example, quartz. The material for forming the concavo-convex structure portions 21 and 41 may be an inorganic material that transmits visible light other than quartz, such as titanium oxide or magnesium fluoride, or an organic material that transmits visible light, such as urethane-modified acrylic. It may be a resin, an acrylic resin such as an epoxy-modified acrylic resin, and various synthetic resins such as an epoxy resin.

  When the material for forming the concavo-convex structure portions 21 and 41 is an inorganic material, the concavo-convex structure portions 21 and 41 perform, for example, a chemical etching process or a physical etching process on a substrate formed of each material. Is formed. Moreover, when the forming material of the concavo-convex structure portions 21 and 41 is a synthetic resin, the concavo-convex structure portions 21 and 41 are formed, for example, by transferring the shape of the original plate to the resin before curing.

  The material for forming the metal layers 22 and 42 is, for example, aluminum. The material for forming the metal layers 22 and 42 may be gold, silver, titanium nitride, or the like, and is a material in which the real part of the complex dielectric constant is a negative value from the ultraviolet region to the visible light region. preferable. If the forming material of the metal layers 22 and 42 has such characteristics, the light transmitted by the excitation of the surface plasmon in the pattern element 11 is included in the visible light region. Therefore, the observer can visually recognize the transmitted light emitted from the display body 10.

  The metal layers 22 and 42 are formed by physical vapor deposition such as vacuum vapor deposition and sputtering. When the metal layers 22 and 42 are formed by a vacuum deposition method, minute irregularities are formed on the surfaces of the metal layers 22 and 42. However, the minute unevenness formed by the vacuum deposition method has a size that does not affect the state of the surface plasmon excited in the pattern element 11. Therefore, the metal layers 22 and 42 may have unevenness, that is, surface roughness to the extent that it is formed by a vacuum deposition method.

  Note that the concavo-convex structure portion 21 of the pattern element 11 and the concavo-convex structure portion 41 of the reflection suppressing portion 12 may be formed of different materials selected from the materials described above. Moreover, the metal layer 22 of the pattern element 11 and the metal layer 42 of the reflection suppressing unit 12 may be formed of different materials selected from the materials described above.

[Action of display body]
With reference to FIG. 7 and FIG. 8, the operation of the display body 10 will be described together with an observation method of the display body 10. Hereinafter, an example will be described in which the display body 10 is observed in a state where it is attached to an object to be authenticated, which is a target for determining whether or not it is a genuine product.

  As shown in FIG. 7, the display body 10 is an object to be authenticated 60 and is attached to various cards such as an ID card. The object 60 to be authenticated is a base material to which the display body 10 is attached, and includes a base material having a light transmission property that allows light to reach the display body 10. Or the part to which the display body 10 is attached | subjected should just have a light transmittance among base materials. The display body 10 is attached to the authentication target 60 with the back surface 13 r of the pattern layer 13 facing the authentication target 60. In addition, the display body 10 may be attached to the authentication target 60 by attaching the display body 10 in a hole formed in the base material in a state in which light is directly incident on the display body 10.

  The front side of the display body 10 and the side opposite to the side on which the pattern layer 13 is positioned with respect to the lens array layer 16 is an observation side by the observer OB. For example, the observer OB observes the display body 10 from the direction in which the display body 10 is viewed from the front.

  When the observer OB observes the light incident on the display body 10 from the front side, the light source LS that irradiates light toward the display body 10 is located on the observation side of the display body 10 and faces the display body 10. White light is irradiated as the irradiation light IL. Thereby, the light source LS irradiates the surface 13 s of the pattern layer 13 with the irradiation light IL through the lens array layer 16.

  At this time, the reflection suppression unit 12 in the pattern layer 13 suppresses and absorbs the reflection of light incident on the reflection suppression unit 12 in the irradiation light IL, so that an image having black or dark gray is on the front side. indicate. Further, the pattern element 11 also absorbs light incident on the pattern element 11 in the irradiation light IL, and displays an image having black or dark gray on the front side. That is, the reflected light RL reflected by the pattern layer 13 hardly occurs. Accordingly, the observer OB can observe the image 17 having one black or dark gray color through the lens array layer 16.

  On the other hand, as shown in FIG. 8, when the observer OB observes the light incident on the display body 10 from the back side, the light source LS is connected to the display side 10 on the observation side of the display body 10. Is positioned on the opposite side and irradiates the display body 10 with the irradiation light IL through the object 60 to be authenticated. Thereby, the light source LS irradiates the back surface 13r of the pattern layer 13 with the irradiation light IL through the authentication target 60.

  At this time, the reflection suppression unit 12 in the pattern layer 13 suppresses and absorbs the reflection of the light incident on the reflection suppression unit 12 in the irradiation light IL, and thus the image 18a having a black or dark gray color is front side. To display. On the other hand, the pattern element 11 excites surface plasmons with light incident from the back surface 13r of the pattern layer 13, and emits transmitted light TL having a color different from the irradiation light IL to the front side. Thereby, the pattern element 11 forms a pattern with the transmitted light TL, and the plurality of lenses 14 enlarge each pattern to form one image 18b. Thus, the display body 10 can form the image 18 composed of the background image 18a and the image 18b expressing the asterisk.

Thus, according to the observation method including irradiating the pattern layer 13 with light from the back side and observing the light transmitted through the pattern layer 13 and the lens 14 from the front side, the observer OB The enlarged image 18b and the background image 18a can be observed.
The observation of the display body 10 is not limited to the observer OB, and may be performed by a device that can detect an image formed by the display body 10.

As described above, according to one embodiment of the display body, the effects listed below can be obtained.
(1) Since the reflection suppressing unit 12 and the pattern element 11 absorb light from the front side, the display body 10 forms one image with low brightness on the front side. On the other hand, while the reflection suppressing unit 12 absorbs light incident from the back side, the pattern element forms a pattern with light having a color different from the light incident from the back side. An image 18a having a low brightness and an image 18b having an enlarged pattern are formed facing the front side. Thus, since the display body 10 forms the image 18b enlarged only by the light incident from the back side, the display body 10 can display the image 18b enlarged more effectively.

  (2) If the lens 14B is a gradient index lens, the surface through which the light transmitted through the pattern element 11 and the lens 14B and contributing to the formation of the enlarged image 18b is emitted is a flat surface. is there. Therefore, compared to the configuration in which the lens has a curved surface, transmitted light is less likely to be scattered when emitted from the lens 14B. Therefore, the display body 10 can display a clearer image 18b.

  (3) According to the observation method of the display body 10, when the pattern layer 13 is irradiated with light from the back side, the enlarged image 18b of the pattern can be observed.

The embodiment described above can be implemented with appropriate modifications as follows.
If the light irradiated to the display body 10 when observing the display body 10 includes light capable of exciting surface plasmons in the pattern element 11 and includes light whose reflection is suppressed by the reflection suppressing unit 12, Light other than white light may be used.

  As shown in FIG. 9, the display body 70 is a protective layer 71 that has light transmittance, covers the surface 13 s of the pattern layer 13, and fills the unevenness on the surface 13 s of the pattern layer 13. A protective layer 71 positioned between the lens array layer 16 and the lens array layer 16 may be provided.

  According to the protective layer 71, since the lens array layer 16 does not directly contact the pattern layer 13, the shape of the unevenness formed on the surface 13s facing the lens array layer 16 is unlikely to change. Moreover, according to the part which overlaps with the pattern element 11 among the protective layers 71, the selectivity of the resonant wavelength in which the surface plasmon in the pattern element 11 is excited, ie, at least one of the selection wavelength width and the light absorption amount is changed. be able to. Even if the display body 70 includes the protective layer 71, the impedance is not changed at the interface between the reflection suppressing unit 12 and the portion of the protective layer 71 that covers the reflection suppressing unit 12. The suppression unit 12 suppresses reflection of light.

  The material for forming the protective layer 71 may be, for example, a resin having a light transmitting property and a dielectric material having a light transmitting property. When the forming material of the protective layer 71 is a resin, the forming material is, for example, polyethylene, polypropylene, polytetrafluoroethylene, polymethyl methacrylate, polystyrene, or the like.

When the forming material of the protective layer 71 is a dielectric material, the forming material is, for example, Sb ₂ O ₃ , Fe ₂ O ₃ , TiO ₂ , CdS, CeO ₂ , ZnS, PbCl ₂ , CdO, WO ₃ , SiO, Si ₂ O ₃ , In ₂ O ₃ , PbO, Ta ₂ O ₃ , ZnO, ZrO ₂ , MgO, Si ₂ O ₂ , MgF ₂ , CeF ₃ , CaF ₂ , AlF ₃ , Al ₂ O ₃ , GaO, etc. It is.

  In addition, when the forming material of the protective layer 71 is resin, the pigment | dye may be added with respect to resin. Thereby, according to the absorption wavelength of a pigment | dye, the selectivity of the resonance wavelength which the surface plasmon in the pattern element 11 is excited, ie, at least one of the selection wavelength width, and the light absorption amount can be changed. Further, by changing the dye contained in the protective layer 71 from one dye to another, the selectivity of the resonance wavelength at which the surface plasmon in the pattern element 11 is excited by the difference in absorption wavelength between the dyes, that is, At least one of the selected wavelength width and the amount of light absorption can be changed.

According to such a configuration, the following effects can be obtained.
(4) Since the lens array layer 16 is not in direct contact with the pattern layer 13, the shape of the unevenness formed on the surface 13 s facing the lens array layer 16 is difficult to change.

  (5) The selectivity of the resonance wavelength at which the surface plasmon in the pattern element 11 is excited, that is, at least one of the selected wavelength width and the light absorption amount can be changed.

  As shown in FIG. 10, the display body 80 may include a reflection suppressing layer 81 that has a light transmission property and covers a surface opposite to the surface facing the pattern layer 13 with respect to each lens 14. . The reflection suppression layer 81 is located on the opposite side of the lens array layer 16 from the pattern layer 13 and covers the surface 16 s of the lens array layer 16.

  The reflection suppression layer 81 may have a single layer structure or a multilayer structure. When the reflection suppression layer 81 has a single-layer structure, the formation material of the reflection suppression layer 81 may be a material having a lower refractive index than the formation material of the lens array layer 16. When the reflection suppressing layer 81 has a multilayer structure, the reflection suppressing layer 81 includes, for example, a high refractive index layer having a relatively high refractive index and two low refractive index layers having a relatively low refractive index, It is sufficient if the two low refractive index layers sandwich the high refractive index layer.

According to such a configuration, the following effects can be obtained.
(6) The light reflected from the surface 16 s of the lens array layer 16 is less likely to be mixed with the transmitted light emitted through the lens 14. Therefore, the enlarged image displayed by the display body 80 becomes clearer.

  -The lens which comprises the lens array layer 16 may be other lenses, such as a cylindrical lens. Even in such a configuration, if the plurality of lenses can enlarge each of the plurality of patterns to form one image in which a part of the enlarged image of each pattern is aggregated, the above-described case is possible. The same effect as (1) can be obtained.

  A single pattern element 11 includes a first portion including a plasmon structure that transmits light having a first color, and a plasmon structure that transmits light having a second color different from the first color A second portion including a body may be included. That is, the pattern formed by the pattern element 11 may include a portion having the first color and a portion having a second color different from the first color.

  According to such a configuration, since one pattern includes portions having different colors, the image displayed on the display body 10 is more complicated than a configuration in which the pattern has one color.

  The color of transmitted light is determined by the state of surface plasmons formed on the metal layer 22. Therefore, between the first part and the second part described above, the convex period P3, the distance D between the surface 31s and the virtual plane S, the arrangement state of the convex parts 32 on the surface 31s, the thickness of the metal layer 22 It suffices that at least one of M and the material for forming the metal layer 22 is different from each other. Thereby, the state of the surface plasmon excited in the first part and the state of the surface plasmon excited in the second part are made different from each other. As a result, the color of the transmitted light in the first part and the second part The colors of transmitted light in can be made different from each other.

The pattern element 11 may include three or more parts having different transmitted light colors.
The pattern element 11 may be configured to transmit white light. In the pattern element 11, for example, if the convex period P3 is irregular or the height of the convex part 32 is not uniform, it is formed at the minimum unit of the plasmon structure, that is, one interface 23. Each state of surface plasmon is different from each other. As a result, the color of the light transmitted through the pattern element 11 becomes white.

As long as surface plasmon excitation in the metal layer 22 is possible, the convex period P3 may be smaller than 100 nm.
As long as surface plasmon excitation in the metal layer 22 is possible, the thickness M of the metal layer 22 may be smaller than 20 nm or larger than 100 nm.

  The pattern element 11 may further include a portion that emits light having substantially the same wavelength as the light incident on the pattern element 11, that is, light having substantially the same color as the incident light. In addition, the metal layer 22 may include a portion that is thin enough to transmit a part of the incident light as it is without exciting the surface plasmon from the incident light incident on the back surface 13r of the pattern layer 13. .

  The thickness of the metal layer 42 may be smaller than 20 nm or larger than 100 nm. Even with such a configuration, light absorption by the metal layer 42 is possible.

  -The pattern element 11 and the reflection suppression part 12 may be piled up on another base material, and in this case, the back surface 13r of the plate-shaped part 31 with which the pattern element 11 is provided, and the reflection suppression part 12 The back surface 51r of the plate-shaped part 51 provided should just oppose the base material. In this case, the surface of the substrate opposite to the surface facing the pattern element 11 and the reflection suppressing portion 12 constitutes the back surface 13r of the pattern layer 13.

  The display body is not the display body 10 for suppressing the forgery of the authentication object 60 by making it possible to determine the authenticity of the authentication object 60, for example, a display attached to the object for the purpose of decorating the object The display body itself may be a display body that is the object of viewing.

  In the configuration in which the display body is the object of viewing, for example, the display body can be applied to a game card. Below, with reference to FIG. 11 and FIG. 12, the example in which the display body was applied to the game card is demonstrated.

  As shown in FIG. 11, the gaming card 90 includes a display body 91 and a base material 92 to which the display body 91 is attached. The display body 91 is in a state in which light can reach the display body 91 through the base material 92, or light is directly applied to the display body 91, similarly to the display body 10 attached to the authentication target body 60. The substrate 92 is attached in an irradiated state.

  When the gaming card 90 is used for gaming, the gaming card 90 is placed on a stage St having light transparency. A light source LS is positioned below the stage St, and the light source LS irradiates light toward the opposite side of the light source LS to the stage St through the stage St.

  When the light of the light source LS is not irradiated toward the stage St, the observer of the game card 90 is light that has entered the surface 13s of the pattern layer 13 through the lens array layer 16, and the pattern layer The light reflected by the surface 13s of 13 is observed. As described above, most of the light incident on the pattern layer 13 is suppressed and absorbed by the pattern layer 13. Therefore, the observer visually recognizes one image 93 having black or dark gray as the image 93 formed by the display body 91.

  On the other hand, as shown in FIG. 12, when the light of the light source LS is irradiated toward the stage St, the observer of the game card 90 is the light incident on the back surface 13r of the pattern layer 13. And the light which permeate | transmitted the pattern layer 13 is observed. As described above, in the pattern layer 13, light incident on the pattern element 11 is emitted as transmitted light having a predetermined color, so that each pattern element 11 forms one pattern while reflecting. Most of the light incident on the suppression unit 12 is suppressed and absorbed by the reflection suppression unit 12.

  Thereby, the reflection suppression part 12 forms the one image 94a which has black or dark gray like the time when the light of the light source LS is not irradiated among the display bodies 91, and the some lens 14 is. Each pattern is enlarged to form one image 94b, for example, an image 94b representing a dragon. Therefore, the observer can visually recognize an image 94 composed of an image 94b representing a dragon and an image 94a serving as a background of the image 94b as the image 94 formed by the display body 91.

  DESCRIPTION OF SYMBOLS 10,70,80,91 ... Display body, 11 ... Pattern element, 12 ... Reflection suppression part, 13 ... Pattern layer, 13r, 16r, 31r, 51r ... Back surface, 13s, 16s, 22s, 31s, 51s ... Front surface, 14 , 14A, 14B ... lens, 15 ... support portion, 16, 16A, 16B ... lens array layer, 17, 18, 18a, 18b, 93, 94, 94a, 94b ... image, 21, 41 ... concavo-convex structure portion, 22, 42 ... Metal layer, 23 ... Interface, 31,51 ... Plate-like part, 32,52 ... Convex part, 32a ... Top surface, 32b ... Side face, 53 ... Concave part, 60 ... Subject to be authenticated, 71 ... Protective layer, 81 ... Antireflection layer, 90 ... game card, 92 ... base material, A ... optical axis, LS ... light source, S ... virtual plane, S1 ... first uneven surface, S2 ... second uneven surface, St ... stage.

Claims (5)

A pattern layer composed of a plurality of pattern elements, each of which forms a pattern by light transmission, and a reflection suppressing portion that fills between the adjacent pattern elements;
A plurality of lenses each having a focus on a separate pattern element, the plurality of lenses comprising the plurality of lenses that magnify each pattern to form a single image;
The side where the lens is positioned with respect to the pattern element is the front side,
The side opposite to the side where the lens is positioned with respect to the pattern element is the back side,
The surface of the pattern layer is composed of a first uneven surface that is the surface of each pattern element and a second uneven surface that is the surface of the reflection suppressing portion.
The period of the unevenness on the second uneven surface has a size that suppresses reflection of light incident from the front side and reflection of light incident from the back side with respect to the reflection suppression unit, and the reflection suppression unit Has the property of absorbing light incident from the front side and light incident from the back side,
Of the front side and the back side, one is the incident side, and other than the incident side is the non-incident side,
The pattern element includes a concavo-convex structure portion that is a dielectric and a metal layer that covers at least a part of the surface of the concavo-convex structure portion, absorbs a part of light from the incident side, and A display body that emits light having a color different from light from the side toward the non-incident side and forms the pattern by light from the back side. Each of the lenses has an optical axis extending along a direction in which the lens and the pattern element overlap, has a refractive index distribution along a radial direction of the optical axis, and is a surface facing the pattern layer. The display body according to claim 1, wherein the display body is a radial type gradient index lens having a flat surface as an opposite surface. The display body according to claim 1, further comprising a reflection suppressing layer that has light transmittance and covers a surface of each lens opposite to the surface facing the pattern layer. The display body according to any one of claims 1 to 3, further comprising a protective layer that has light transmittance and covers the surface of the pattern layer to fill the unevenness on the surface of the pattern layer. A method of observing a display body,
The display body is the display body according to any one of claims 1 to 4,
Irradiating light from the back side to the pattern layer;
Observing light transmitted through the pattern layer and the lens from the front side.