JP6769226B2 - Display body and manufacturing method of display body - Google Patents

Description

The present invention relates to a display body using a structural color and a method for manufacturing the display body.

The display body is configured to exhibit a structural color, and is required to be difficult to forge, such as authentication documents such as passports and driver's licenses, and securities such as gift certificates and checks. By being prepared for, the difficulty of counterfeiting goods is increased. Further, for example, the display body is provided on the articles around us to enhance the design of the articles.

Structural colors such as morpho butterfly scales and jade skin are different from the colors that are visible due to electron transitions in molecules, such as the colors exhibited by pigments, and are different from the colors that are visible due to electron transitions in molecules, such as light diffraction, interference, and scattering. It is a color that is visually recognized by the action of an optical phenomenon caused by the structure. The use of structural colors enhances the difficulty and design of articles with displays.

For example, the structural color due to multilayer film interference is a structural color generated when light in a specific wavelength range reflected at each interface of a multilayer film is intensified by interference, and a display body using multilayer film interference is widely known. There is. However, since the color exhibited by the display body due to the multilayer film interference depends on the layer structure such as the film thickness of each layer in the multilayer film, in the display body using the multilayer film interference, each color to be visually recognized by the display body is mutually exclusive. It is necessary to form a multilayer film having a different layer structure. Therefore, the manufacturing process of the display body differs greatly due to the difference in color, so that the versatility is poor, and the manufacturing process of the display body having a plurality of regions exhibiting different colors has to be very complicated.

An optical device using a waveguide mode resonance phenomenon has been proposed as a configuration for visually recognizing a structural color by an optical phenomenon different from that of multilayer film interference (see, for example, Patent Documents 1 and 2). This optical device has a sub-wavelength grating that is a diffraction grating that is arranged at a period smaller than the wavelength of light. When light is incident on the sub-wavelength lattice, the emission of diffracted light into the space on the incident side is suppressed, while light in a specific wavelength range propagates while being multiple-reflected, causing resonance and light in this specific wavelength range. Wavelength mode resonance phenomenon occurs in which is strongly emitted as reflected light.

Japanese Patent No. 5023324 Japanese Unexamined Patent Publication No. 2009-25558

When the waveguide mode resonance phenomenon is used for the display body, the higher the intensity of the reflected light emitted from the display body, that is, the higher the wavelength selectivity of the reflected light, the sharper and brighter the color visually recognized by the display body. Therefore, the visibility of the image formed by the display body is enhanced. As a result, it is preferable that the wavelength selectivity of the reflected light is high, because the difficulty of forgery and the design of the article provided with the display body are increased.

For example, Patent Document 1 describes a structure in which a plurality of convex portions forming a sub-wavelength lattice are arranged on a substrate as a structure that causes a waveguide mode resonance phenomenon. However, in order to obtain reflected light having excellent wavelength selectivity by such a structure, as described in Patent Document 1, the substrate is formed from synthetic quartz and the convex portion is formed from silicon. It is desirable to secure a large difference in refractive index between the light and the convex portion to reduce the loss due to multiple reflection of light propagating in the sub-wavelength lattice region. For that purpose, it is necessary to use an SOQ (Silicon on Quartz) substrate in which single crystal Si is formed on a substrate made of synthetic quartz, which causes an increase in manufacturing cost.

On the other hand, Patent Document 2 has a structure in which a waveguide layer made of a material having a higher refractive index than the material forming the substrate is located between the substrate and the convex portion constituting the sub-wavelength lattice. Are listed. According to such a structure, even when the convex portion and the waveguide layer are formed of resin, the wavelength selectivity of the emitted reflected light is enhanced by propagating the multiple reflected light into the waveguide layer. .. Further, since the nanoimprint method can be used as a method for forming the convex portion and the waveguide layer from the resin, the manufacturing can be easily performed while reducing the material cost, and the manufacturing cost can also be reduced.

However, in the structure of Patent Document 2, since the light propagation mode in the waveguide layer is mainly determined by the thickness of the waveguide layer and the wavelength of light, light in a desired wavelength range is multiplely reflected in the waveguide layer. In order to cause resonance, it is necessary to precisely control the film thickness of the waveguide layer. Forming a waveguide layer having a precise film thickness in addition to a convex portion having a fine period imposes a heavy load on manufacturing, so that there is a limit to enhancing wavelength selectivity by the waveguide layer.

An object of the present invention is to provide a display body capable of enhancing the function expressed by the appearance of the display body and a method for manufacturing the display body by utilizing the waveguide mode resonance phenomenon.

The display body that solves the above-mentioned problems is a display body that includes a display element made of a material that transmits incident light and has a front surface and a back surface, and the display elements form a plurality of first sub-wavelength lattices. It has a first high refractive index portion and a plurality of first low refractive index portions having a refractive index lower than that of the first high refractive index portion, and the first high refractive index portion in a direction along the surface. A plurality of second high refractive indexes, which are composed of a first lattice region in which the first low refractive index portion and the first low refractive index portion are alternately located and the same material as the first high refractive index portion to form a second sub-wavelength lattice. The second high refractive index portion and the second low refractive index portion have a portion and a plurality of second low refractive index portions having a refractive index lower than that of the second high refractive index portion, and the second high refractive index portion and the second low refractive index portion are provided in a direction along the surface. The second lattice region in which the rate portions are alternately located, and the first low refractive index region, each of which has a refractive index lower than each of the average refractive index of the first lattice region and the average refractive index of the second lattice region. A second low refractive index region and a third low refractive index region are provided, and the first lattice region includes the first low refractive index region and the second low refractive index region in the thickness direction of the display body. The second lattice region is sandwiched between the second low refractive index region and the third low refractive index region in the thickness direction of the display body, and the lattice period of the first sub-wavelength lattice is sandwiched between the regions. And the lattice period of the second sub-wavelength lattice are equal periods to each other, and the volume ratio of the plurality of first high refractive index portions in the first lattice region and the plurality of firsts in the second lattice region. The volume ratio of the two high refractive index portions is the same, and the first high refractive index portion and the second low refractive index portion overlap when viewed from the direction facing the surface, and the second high refractive index portion And the first low refractive index portion overlap.

According to the above configuration, each lattice region of the first lattice region and the second lattice region has a sub-wavelength lattice, and each lattice region has a low refractive index lower than the refractive index of each lattice region. Since it is sandwiched between the refractive index regions, when light is incident on each lattice region, the emission of diffracted light into the incident side space is suppressed in each lattice region, and a waveguide mode resonance phenomenon occurs. Since the lattice period of each lattice region and the volume ratio of the high refractive index portion are the same, the wavelength region of light that causes resonance in the first lattice region and the wavelength region of light that causes resonance in the second lattice region are Match.

Therefore, the light in a specific wavelength region that leaks out in the process of multiple reflection in one lattice region and enters the other lattice region propagates while being multiple reflected in the other lattice region, and is first transmitted from the display element. The reflected light in the wavelength region enhanced in the lattice region and the reflected light in the wavelength region enhanced in the second lattice region are emitted. Then, among the incident light, light in a wavelength range other than the enhanced wavelength range is transmitted through the display element and emitted from the display element.

As described above, according to the display element having the above configuration, the light in the wavelength range enhanced in each of the two lattice regions is emitted as the reflected light, so that the display element has only one lattice region. The intensity of the light in the specific wavelength range emitted as the reflected light increases. Therefore, since the sharpness and brightness of the colors visually recognized in the display area are enhanced, the visibility of the image formed by the display body is enhanced, and as a result, it is expressed by the difficulty of counterfeiting and the design, that is, the appearance of the display body. Functions are enhanced.

In the above configuration, the display body includes a plurality of the display elements, and the plurality of display elements include a first display element and a second display element, and the display element is viewed from a direction facing the surface. The display body includes a first display area in which the first display element is located and a second display area in which the second display element is located, and the first sub-wavelength grid and the second display in the first display element. The lattice period of the sub-wavelength lattice and the lattice periods of the first sub-wavelength lattice and the second sub-wavelength lattice in the second display element may be different from each other.

According to the above configuration, the hues of the colors visually recognized in the first display area and the second display area can be different. Therefore, it is possible to express various images by these areas. Further, since the difference in the visually recognized hue is realized by the difference in the lattice period of the sub-wavelength lattice, the difference in the manufacturing process of the display element due to the difference in color is small, and the display body can be easily manufactured.

In the above configuration, a portion composed of the first lattice region, the second lattice region, the first low refractive index region, the second low refractive index region, and the third low refractive index region is a resonance structure portion. The display element may include a plurality of the resonance structure portions arranged along the thickness direction of the display body.

According to the above configuration, since the display element includes four or more lattice regions, the wavelength selectivity of the reflected light emitted from the display element is further enhanced, and the wavelength range included in the reflected light and the transmitted light is adjusted. It is possible to increase the degree of freedom of. Therefore, it is possible to increase the visibility of the image formed by the display body and increase the degree of freedom in adjusting the hue of the image visually recognized by the display body.

In the above configuration, the plurality of resonance structure portions include a first resonance structure portion and a second resonance structure portion, and the first sub-wavelength lattice and the second sub-wavelength lattice of the first resonance structure portion. The first structural period, which is the lattice period of the above, and the second structural period, which is the lattice period of the first sub-wavelength lattice and the second sub-wavelength lattice of the second resonance structure portion, may be different from each other.

According to the above configuration, the wavelength range of light that resonates in each lattice region of the first resonance structure and the wavelength range of light that resonates in each lattice region of the second resonance structure are mutually exclusive. different. Therefore, when light is incident on the display element, light in a specific wavelength region is multiple-reflected in each lattice region of the resonance structure portion in the upper layer, and light in a wavelength region that is not multiple-reflected is transmitted through this resonance structure portion. Then, light entering the resonance structure portion of the lower layer and having a wavelength range different from that of the resonance structure portion of the upper layer is multiple-reflected in each lattice region of the resonance structure portion of the lower layer. As a result, from the display element, the light in the first wavelength region enhanced in the lattice region of the first resonance structure portion and the light in the second wavelength region enhanced in the lattice region of the second resonance structure portion. Reflected light including light is emitted. Further, among the wavelength ranges included in the light incident on the display element, the light in the wavelength range other than the first wavelength range and the second wavelength range emitted as the reflected light is emitted as transmitted light. Therefore, it is possible to expand the wavelength range included in the reflected light and narrow the wavelength range included in the transmitted light while increasing the intensity of the reflected light in the display element. Therefore, it is possible to increase the degree of freedom in adjusting the hue observed as reflected light or transmitted light by setting the lattice period of the sub-wavelength lattice of each resonance structure, and the image visually recognized on the display body. The degree of freedom in adjusting the hue of the light can be increased.

In the above configuration, the display body includes a plurality of the display elements, and the plurality of display elements include a first display element and a second display element, and the display element is viewed from a direction facing the surface. The display body includes a first display area in which the first display element is located and a second display area in which the second display element is located, and the first structural period and the second structure in the first display element. At least one of the first structural period and the second structural period may be different between the combination with the period and the combination of the first structural period and the second structural period in the second display element.

According to the above configuration, the first display element and the second display element have different wavelength ranges of light emitted as reflected light and different wavelength ranges of light emitted as transmitted light. As a result, the first display area and the second display area appear to have different colors. According to such a configuration, the difference in the hue visually recognized in each region is realized by the difference in the combination of the first structural period and the second structural period in the display element, so that the hue of the visually recognized image can be freely adjusted. The degree is increased.

In the above configuration, in each of the plurality of resonance structure portions, the plurality of first high refractive index portions, the plurality of first low refractive index portions, the plurality of second high refractive index portions, and the plurality of firsts. The element portion, which is each of the two low refractive index portions, has a shape extending in a band shape in one direction, and the plurality of resonance structure portions include a first resonance structure portion and a second resonance structure portion. The extending direction of the element portion of the first resonance structure portion and the extending direction of the element portion of the second resonance structure portion may be different from each other.

According to the above configuration, in the lattice region of each resonance structure portion, among the light contained in the incident light, the light polarized in the direction corresponding to the arrangement direction of the sub-wavelength lattice causes resonance. Since the arrangement directions of the sub-wavelength lattices are different between the first resonance structure portion and the second resonance structure portion, the lattice region of the first resonance structure portion and the lattice region of the second resonance structure portion are included in the incident light. Of the light, the light polarized in different directions resonates and is emitted from each resonance structure. Therefore, the reflected light is efficiently emitted from the incident light containing the polarized light components in various directions, so that the intensity of the reflected light is further increased. Therefore, in a display body observed under external light containing polarization components in various directions, the effect of improving the sharpness and brightness of the color visually recognized in the display area can be highly obtained, and it is difficult to forge. The design is further enhanced.

In the above configuration, the extending direction of the element portion of the first resonance structure portion and the extending direction of the element portion of the second resonance structure portion are directions along the surface and are orthogonal to each other. You may.
According to the above configuration, the reflected light is emitted more efficiently with respect to the incident light containing the polarized light components in various directions. In addition, the design and manufacture of display elements are easy.

In the above configuration, the first low refractive index region, the first low refractive index portion, and the portion of the second low refractive index region adjacent to the first low refractive index portion are continuous with each other. It is a first structure which is one structure, and is adjacent to the third low refractive index region, the second low refractive index portion, and the second low refractive index portion in the second low refractive index region. The portion to be used may be a second structure which is one structure which is continuous with each other.
According to the above configuration, since the portion that is one structure can be manufactured in one step, the display body can be easily manufactured.

In the above configuration, the difference in refractive index between the first structure and the first high refractive index portion and the second high refractive index portion is larger than 0.2, and the second structure and the first high refractive index are The difference in refractive index between the portion and the second high refractive index portion may be larger than 0.2.

According to the above configuration, the waveguide mode resonance phenomenon is likely to occur favorably in each lattice region, and the intensity of the reflected light from each lattice region is further enhanced. Therefore, the difficulty of counterfeiting and the designability are further enhanced.

In the above configuration, the material constituting the first structure is any of an ultraviolet curable resin, a thermosetting resin, and a thermoplastic resin, and the material constituting the second structure is ultraviolet curable. The material which is any of a resin, a thermosetting resin, and a thermoplastic resin and which constitutes the first high refractive index portion and the second high refractive index portion may contain an inorganic compound.

According to the above configuration, the waveguide mode resonance phenomenon is likely to occur favorably in each lattice region, and the intensity of the reflected light from each lattice region is further enhanced. Therefore, the difficulty of counterfeiting and the designability are further enhanced. Further, it is possible to reduce the material cost required for manufacturing the display body and to apply a simple manufacturing method such as the nanoimprint method.

In the above configuration, the second low refractive index region has the first high refractive index portion and the third high refractive index portion made of the same material as the second high refractive index portion, and the third high refractive index portion. The refractive index portion is formed in the thickness direction of the second low refractive index region between the ends of the first high refractive index portion and the second high refractive index portion that are adjacent to each other when viewed from the direction facing the surface. It may extend along.

According to the above configuration, it is possible to form a high refractive index portion by using a vacuum vapor deposition method, and it is possible to form a suitable sub-wavelength lattice. Even in this case, the configuration of the second low refractive index region for causing the waveguide mode resonance phenomenon is preferably realized.

The method for manufacturing a display body that solves the above problems is a method for manufacturing a display body including a display element composed of a material that transmits incident light, and the step of manufacturing the display element is a first low refractive index material. A plurality of convex portions arranged in a sub-wavelength period on the surface of the layer composed of the same, and concave portions alternately arranged with the convex portions along the arrangement direction of the plurality of convex portions, when viewed from a direction facing the surface. From the first step of forming a concavo-convex structure layer having the convex portion and the concave portion by forming a plurality of concave portions having an area equal to the area of the plurality of convex portions, and from the first low refractive index material. This is a second step of forming a high refractive index layer having a thickness smaller than the height of the convex portion on the surface of the uneven structure layer by using a high refractive index material having a high refractive index. As the refractive index layer, a layer including a first sub-wavelength lattice located on the concave portion and a second sub-wavelength lattice located on the convex portion and having the same lattice period as the first sub-wavelength lattice is formed. On the surface of the structure composed of the concavo-convex structure layer and the high refractive index layer, an embedded layer made of a second low refractive index material having a refractive index lower than that of the high refractive index material is formed. This includes a third step of filling the unevenness of the structure with the second low refractive index material up to the second sub-wavelength lattice.

By the above-mentioned production method, the above-mentioned display body, that is, a display body in which the function expressed by the appearance of the display body is enhanced can be manufactured. Then, according to the above-mentioned manufacturing method, the wavelength selectivity of the reflected light emitted from the display element is enhanced without requiring precise control of the film thickness of the layer in contact with the sub-wavelength lattice, so that the above-mentioned function is enhanced. The display body can be easily manufactured.

In the above manufacturing method, in the first step, the concave plate is pressed against the coating layer made of the resin which is the first low refractive index material, the resin is cured, and then the concave plate is released to remove the unevenness of the concave plate. By transferring to the resin, the uneven structure layer is formed, and in the second step, the high refractive index layer is formed by using a material containing an inorganic compound as the high refractive index material, and the third step. Then, the embedded layer may be formed by applying a resin which is the second low refractive index material to the surface of the structure and curing the applied resin.

According to the above manufacturing method, since the concave-convex structure layer is formed by using the nanoimprint method, the uneven structure layer having fine irregularities can be preferably and easily formed.

In the above manufacturing method, in the third step, the two structures are opposed to each other so that the high refractive index layers face each other, and the region between the two structures is filled with the second low refractive index material. May form the embedded layer.

According to the above manufacturing method, a display element having four or more sub-wavelength grids can be easily manufactured. Therefore, it is easy to manufacture a display body including such a display element.

According to the present invention, the function expressed by the appearance of the display body can be enhanced by utilizing the waveguide mode resonance phenomenon.

The figure which shows the planar structure of the display body about 1st Embodiment of a display body. The figure which shows the cross-sectional structure of a pixel and the planar structure of a lattice region provided in the display body of 1st Embodiment. The figure which shows the operation of the display body of 1st Embodiment. The figure which shows the formation process of the concavo-convex structure layer about 1st Embodiment of the manufacturing method of a display body. The figure which shows the formation process of the high refractive index layer about 1st Embodiment of the manufacturing method of a display body. The figure which shows the forming process of the embedding layer about 1st Embodiment of the manufacturing method of a display body. FIG. 5 is a cross-sectional view showing a configuration example of a second low refractive index region in a pixel included in the display body of the first embodiment. FIG. 5 is a cross-sectional view showing a modified example of pixels included in the display body of the first embodiment. FIG. 5 is a cross-sectional view showing a modified example of pixels included in the display body of the first embodiment. A cross-sectional view showing an example of a cross-sectional structure of pixels included in a display body according to a second embodiment of the display body. A cross-sectional view showing an example of a cross-sectional structure of pixels included in a display body according to a second embodiment of the display body. The figure which shows the state which the concavo-convex structure faces each other about the 2nd Embodiment of the manufacturing method of a display body. The figure which shows the formation process of the embedded layer about 2nd Embodiment of the manufacturing method of a display body. A perspective view showing a perspective structure of pixels included in the display body according to a third embodiment of the display body. A perspective view showing a third embodiment of a display body in which pixels included in the display body are divided into regions. The plan view which shows the plane structure of the lattice area in the display body of a modification. The perspective view which shows the perspective structure of the concave-convex structure layer in the display body of a modification. The figure which shows the sub-wavelength lattice pattern of an Example in a simplified manner.

(First Embodiment)

A display body and a first embodiment of a method for manufacturing the display body will be described with reference to FIGS. 1 to 9. The display body may be used for the purpose of increasing the difficulty of forgery of the article, may be used for the purpose of enhancing the design of the article, or may be used for these purposes in combination. For the purpose of increasing the difficulty of counterfeiting goods, the display body is, for example, authentication documents such as passports and driver's licenses, securities such as gift certificates and checks, cards such as credit cards and cash cards, banknotes, etc. It will be pasted. In addition, for the purpose of enhancing the design of the article, the display body is, for example, a decorative object to be worn, an article carried by a user, an article to be stationary such as furniture or a home appliance, a wall, a door, or the like. It can be attached to structures, etc.

The incident light emitted to the display body of the present embodiment is light that can be visually recognized by the human eye, that is, light in the visible region. In the following, the wavelength of light in the visible region is 400 nm or more and 800 nm or less.

[Display body configuration]
The configuration of the display body of the first embodiment will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the display body 100 has a front surface 100F and a back surface 100R which is a surface opposite to the front surface 100F, and includes a first pixel 10A, a second pixel 10B, and a third pixel 10C. It has a plurality of pixels 10. Pixel 10 is an example of a display element.

When viewed from the direction facing the surface 100F, the display body 100 includes a first display area 110A, a second display area 110B, and a third display area 110C. The first display area 110A is an area in which a plurality of first pixels 10A are arranged, the second display area 110B is an area in which a plurality of second pixels 10B are arranged, and the third display area 110C is an area in which a plurality of second pixels 10B are arranged. , This is an area in which a plurality of third pixels 10C are arranged. In other words, the first display area 110A is composed of a set of a plurality of first pixels 10A, and the second display area 110B is composed of a set of a plurality of second pixels 10B, and is a third display area. The 110C is composed of a set of a plurality of third pixels 10C.

The first pixel 10A, the second pixel 10B, and the third pixel 10C exhibit different hues, that is, the first display area 110A, the second display area 110B, and the third display area 110C have different hues. This is the area where the color of is visible. Each of the first display area 110A, the second display area 110B, and the third display area 110C may be a character, a symbol, a figure, a pattern, a pattern, or a combination of these areas alone or two or more of these areas. Express the background of. As an example, in the configuration shown in FIG. 1, a circular figure is represented by the first display area 110A, a triangular figure is represented by the second display area 110B, and a background is represented by the third display area 110C.

The detailed structure of the pixel 10 will be described with reference to FIG. The structure described below is a structure common to the first pixel 10A, the second pixel 10B, and the third pixel 10C.
As shown in FIG. 2, the pixel 10 includes the base material 11, the first low refractive index region 12, the first lattice region 13, the second low refractive index region 14, the second lattice region 15, and the third low refractive index. The region 16 is provided. Each of the first low refractive index region 12, the first lattice region 13, the second low refractive index region 14, the second lattice region 15, and the third low refractive index region 16 spreads in a layered manner, and the base material 11 They are arranged in this order from the position closest to. The direction in which the regions are lined up is the first direction, that is, the thickness direction of each region, and the thickness direction of the display body 100, that is, the direction from the back surface 100R to the front surface 100F. Further, the side of the third low refractive index region 16 with respect to the base material 11 is the front surface side of the display body 100, and the side of the base material 11 with respect to the third low refractive index region 16 is the back surface side of the display body 100. In FIG. 2, the cross-sectional structure of the pixel 10 is shown, and the planar structure of the first lattice region 13 and the planar structure of the second lattice region 15 are shown by partially breaking these regions.

The base material 11 has a plate shape, and among the surfaces of the base material 11, the surface located on the surface side of the display body 100 is the surface of the base material 11. When the light incident on the display body 100 is light in the visible region, for example, a synthetic quartz substrate or a film made of a resin such as polyethylene terephthalate or polyethylene naphthalate is used as the base material 11.

The first low refractive index region 12 is in contact with the surface of the base material 11 and extends along the surface of the base material 11. The first lattice region 13 has a plurality of first high refractive index portions 13a and a plurality of first low refractive index portions 13b. Each of the first high refractive index portion 13a and the first low refractive index portion 13b is viewed from a direction facing the surface 100F of the display body 100, that is, when viewed from a direction along the first direction, in one direction. It has a band shape extending along the second direction. The first high refractive index portion 13a and the first low refractive index portion 13b are alternately arranged along a third direction orthogonal to the second direction. The second direction and the third direction are directions along the surface 100F of the display body 100, and each of the second direction and the third direction is orthogonal to the first direction. The first lattice region 13 is sandwiched between the first low refractive index region 12 and the second low refractive index region 14 along the first direction, and is in contact with each of these regions.

The second lattice region 15 has a plurality of second high refractive index portions 15a and a plurality of second low refractive index portions 15b. Each of the second high refractive index portion 15a and the second low refractive index portion 15b has a band shape extending along the second direction when viewed from the direction along the first direction, and the second high refractive index portion 15a. The 15a and the second low refractive index portion 15b are alternately arranged along the third direction. That is, the extending direction of the first high refractive index portion 13a and the first low refractive index portion 13b coincides with the extending direction of the second high refractive index portion 15a and the second low refractive index portion 15b, and the first high. The direction in which the refractive index portions 13a and the first low refractive index portion 13b are arranged coincides with the direction in which the second high refractive index portion 15a and the second low refractive index portion 15b are arranged. Then, when viewed from the direction along the first direction, the first high refractive index portion 13a and the second low refractive index portion 15b overlap, and the second high refractive index portion 15a and the first low refractive index portion 13b overlap. ing. The second lattice region 15 is sandwiched between the second low refractive index region 14 and the third low refractive index region 16 along the first direction, and is in contact with each of these regions. In FIG. 2, the planar structure of the first lattice region 13 and the second lattice region 15 is shown by adding dots to the first high refractive index portion 13a and the second high refractive index portion 15a.

The first high refractive index portion 13a and the second high refractive index portion 15a are made of the same material, that is, the refractive index of the first high refractive index portion 13a and the refractive index of the second high refractive index portion 15a. Are equal to each other. The refractive index of the first high refractive index portion 13a and the second high refractive index portion 15a is higher than the refractive index of each of the first low refractive index portion 13b and the second low refractive index portion 15b. Further, the refractive indexes of the first high refractive index portion 13a and the second high refractive index portion 15a are each of the first low refractive index region 12, the second low refractive index region 14, and the third low refractive index region 16. Higher than the refractive index.

Each of the first low refractive index region 12, the second low refractive index region 14, the third low refractive index region 16, the first low refractive index portion 13b, and the second low refractive index portion 15b are made of the same material. That is, all of these indices of refraction are equal. The refractive index of the first low refractive index region 12 is constant regardless of the portion in the region, and the refractive index of the second low refractive index region 14 is also constant regardless of the portion in the region, and is the third low. The refractive index of the refractive index region 16 is also constant regardless of the portion within the region.

The length of the first high refractive index portion 13a in the third direction is the first high element width Dh1, and the length of the first low refractive index portion 13b in the third direction is the first low element width Dl1. The total length of the first high element width Dh1 and the first low element width Dl1 is the period of the arrangement of the first high refractive index portion 13a and the first low refractive index portion 13b in the first lattice region 13. One cycle P1.

The length of the second high refractive index portion 15a in the third direction is the second high element width Dh2, and the length of the second low refractive index portion 15b in the third direction is the second low element width Dl2. The total length of the second high element width Dh2 and the second low element width Dl2 is the period of the arrangement of the second high refractive index portion 15a and the second low refractive index portion 15b in the second lattice region 15. Two cycles P2.

The first high element width Dh1, the first low element width Dl1, the second high element width Dh2, and the second low element width Dl2 are all equal. Then, the first cycle P1 and the second cycle P2 coincide with each other.

The first period P1 and the second period P2 are smaller than the wavelength of light in the visible region, that is, each of the first period P1 and the second period P2 is a sub-wavelength period. In such a configuration, the plurality of first high-refractive index portions 13a in the first lattice region 13 and the plurality of second high-refractive index portions 15a in the second lattice region 15 cause a waveguide mode resonance phenomenon in their respective regions. It constitutes a sub-wavelength grid to generate. The sub-wavelength lattice formed by the first high-refractive index unit 13a and the sub-wavelength lattice formed by the second high-refractive index unit 15a have the same lattice period. That is, the pixel 10 has a structure in which two sub-wavelength lattices arranged with a gap in the first direction are embedded in a material having a refractive index lower than that of the material constituting these sub-wavelength lattices.

Further, the thickness of the first lattice region 13 is the thickness T1 of the first region, and the thickness of the second lattice region 15 is the thickness T2 of the second region. The first region thickness T1 and the second region thickness T2 are in agreement. The thickness of each of the first low refractive index region 12, the second low refractive index region 14, and the third low refractive index region 16 is not particularly limited.

In the above configuration, the refractive index of the first lattice region 13 is the first high refractive index portion 13a according to the volume ratio of the first high refractive index portion 13a and the first low refractive index portion 13b in the first lattice region 13. It is approximated to the average refractive index obtained by equalizing the refractive index of the above and the refractive index of the first low refractive index portion 13b. Since the volume ratio of the first high refractive index portion 13a and the first low refractive index portion 13b in the first lattice region 13 is 1: 1, the average refractive index of the first lattice region 13 is the first high refractive index portion. It is an average value of the refractive index of 13a and the refractive index of the first low refractive index portion 13b.

Similarly, since the volume ratio of the second high refractive index portion 15a and the second low refractive index portion 15b is 1: 1, the average refractive index of the second lattice region 15 is the refraction of the second high refractive index portion 15a. It is an average value of the rate and the refractive index of the second low refractive index section 15b, and is consistent with the average refractive index of the first lattice region 13. Then, the volume ratio of the first high refractive index portion 13a in the first lattice region 13 is equal to the volume ratio of the second high refractive index portion 15a in the second lattice region 15.

Here, in order to cause the waveguide mode resonance phenomenon in each of the first lattice region 13 and the second lattice region 15, the refractive index of the first lattice region 13 and the first low refraction sandwiching the first lattice region 13 are interposed. The difference between the refractive index of each of the rate region 12 and the second low refractive index region 14 is preferably larger than 0.1. Similarly, the difference between the refractive index of the second lattice region 15 and the refractive index of each of the second low refractive index region 14 and the third low refractive index region 16 sandwiching the second lattice region 15 is 0.1. Is preferably larger than.

Therefore, the refractive index of the high refractive index material constituting the first high refractive index portion 13a and the second high refractive index portion 15a, the first low refractive index region 12, the second low refractive index region 14, and the third low refractive index. The difference between the refractive index of the low refractive index material constituting the region 16, the first low refractive index portion 13b, and the second low refractive index portion 15b is preferably larger than 0.2.

When the incident light on the display body 100 is light in the visible region, the low refractive index material includes an inorganic substance such as synthetic quartz or a polymer material such as an ultraviolet curable resin, a thermoplastic resin, or a thermocurable resin. In this case, as the high refractive index material, TiO ₂ (titanium oxide), Nb ₂ O ₅ (niobium oxide), Ta ₂ O ₅ (tantalum pentoxide), ZrO (zinc sulfide), ZnS Inorganic dielectric materials such as (zinc sulfide) can be used.

When the base material 11 and all of the regions 12 to 16 are made of a material that transmits the incident light to the display body 100, the pixel 10 has wavelength selectivity for both the reflected light and the transmitted light. ..

[Action of display body]
When light is incident on the pixel 10 from the surface side of the display body 100, the second lattice region 15 has a sub-wavelength lattice, and the second lattice region 15 has a refractive index lower than that of the second lattice region 15. Since it is sandwiched between the second low refractive index region 14 and the third low refractive index region 16, the emission of diffracted light to the surface side is suppressed in the second lattice region 15, and the waveguide mode resonance phenomenon occurs. Occurs. That is, light in a specific wavelength region propagates while being multiple-reflected in the second lattice region 15 to cause resonance, and the light in this specific wavelength region is emitted as reflected light to the surface side of the pixel 10. The wavelength region of light that resonates in the second lattice region 15 is determined by the second high element width Dh2, the second period P2, and the second region thickness T2 in the second lattice region 15.

Here, it is unlikely that the light in the specific wavelength region propagating in the second lattice region 15 is multiple-reflected in the second lattice region 15 without loss, and a part of the light in the specific wavelength region is the first. Every reflection within the two grid regions 15 leaks into the second low index region 14. The leaked light passes through the second low refractive index region 14 and enters the first lattice region 13.
Further, light in a wavelength region other than the specific wavelength region passes through the second low refractive index region 14 and enters the first grid region 13 without multiple reflection in the second grid region 15.

When light is incident on the first lattice region 13, the first lattice region 13 has a sub-wavelength lattice, and the first lattice region 13 has a refractive index lower than that of the first lattice region 13. Since it is sandwiched between the low refractive index region 12 and the second low refractive index region 14, the waveguide mode resonance phenomenon also occurs in the first lattice region 13. The wavelength range of light that resonates in the first lattice region 13 is determined by the first high element width Dh1 in the first lattice region 13, the first period P1, and the first region thickness T1. In the first lattice region 13 and the second lattice region 15, the first high element width Dh1 coincides with the second high element width Dh2, the first period P1 coincides with the second period P2, and the first region thickness T1. Consistent with the second region thickness T2. Therefore, the wavelength range of the light that resonates in the first lattice region 13 is the same as the wavelength range of the light that resonates in the second lattice region 15.

Therefore, the light that leaks out in the process of multiple reflection in the second lattice region 15 and enters the first lattice region 13 propagates while being multiple reflected in the first lattice region 13 to cause resonance, and the surface of the display body 100 It is emitted as reflected light to the side.
Then, the light in the wavelength region that does not cause multiple reflection in the first lattice region 13 passes through the first low refractive index region 12 and the base material 11 and exits to the back surface side of the display body 100.

As a result, light in the wavelength region enhanced in the second lattice region 15 and light in the wavelength region enhanced in the first lattice region 13 are emitted from the pixel 10 to the surface side of the display body 100. Since the wavelength ranges of these lights are the same, the intensity of the light in the specific wavelength range emitted from the pixel 10 as reflected light is higher than that of a pixel having only one lattice region, and the reflected light has a higher wavelength range. Wavelength selectivity is enhanced.

Then, among the wavelength ranges included in the light incident on the display body 100, the light in the wavelength range other than the specific wavelength range emitted as the reflected light is used as transmitted light from the pixel 10 to the back surface of the display body 100. It is ejected to the side.

When light is incident on the pixel 10 from the back surface side of the display body 100, the reflected light in the wavelength region enhanced in the second lattice region 15 and the reflected light in the wavelength region enhanced in the first lattice region 13 Is ejected from the pixel 10 to the back surface side of the display body 100. Then, among the wavelength ranges included in the incident light, the light in the wavelength range other than the wavelength range emitted as the reflected light is emitted from the pixel 10 to the surface side of the display body 100 as transmitted light.

Here, in the first pixel 10A, the second pixel 10B, and the third pixel 10C, the first period P1 of the first lattice region 13, that is, the second period P2 of the second lattice region 15 is set for each pixel. It is a different cycle. Therefore, in the first pixel 10A, the second pixel 10B, and the third pixel 10C, the wavelength ranges in which resonance due to the waveguide mode resonance phenomenon occurs in the first lattice region 13 and the second lattice region 15 are different from each other.

As a result, when incident light containing light of a plurality of wavelengths is received, the wavelength range of the reflected light emitted from the first pixel 10A, the wavelength range of the reflected light emitted from the second pixel 10B, and the third pixel. The wavelength range of the light emitted from 10C is different from each other. Further, when the incident light is received, the wavelength range of the transmitted light emitted from the first pixel 10A, the wavelength range of the transmitted light emitted from the second pixel 10B, and the transmitted light emitted from the third pixel 10C. Wavelength range is different from each other.

That is, as shown in FIG. 3, when the incident light I1 is irradiated from the outside of the display body 100 toward the surface 100F of the display body 100, the surface side of the display body 100 is reflected light from the first pixel 10A. I2 is emitted, reflected light I3 is emitted from the second pixel 10B, and reflected light I4 is emitted from the third pixel 10C. Therefore, when the surface 100F of the display body 100 is viewed from the surface side, the hue color corresponding to the wavelength range of the reflected light I2 is visually recognized in the first display area 110A, and the wavelength of the reflected light I3 is recognized in the second display area 110B. The hue color corresponding to the region is visually recognized, and the hue color corresponding to the wavelength region of the reflected light I4 is visually recognized in the third display region 110C. Since the wavelength range of the reflected light I2, the wavelength range of the reflected light I3, and the wavelength range of the reflected light I4 are different from each other, the first display area 110A, the second display area 110B, and the third display area 110C have different hues. Looks like the color of.

Therefore, according to the surface reflection observation in which the surface 100F is observed from the surface side of the display body 100 in a state where the incident light I1 is irradiated from the outside of the display body 100 toward the surface 100F, the first display of different colors is observed. An image composed of the area 110A, the second display area 110B, and the third display area 110C is visually recognized.

Further, when the incident light I1 is irradiated from the outside of the display body 100 toward the surface 100F of the display body 100, the transmitted light I5 is emitted from the first pixel 10A to the back surface side of the display body 100, and the second The transmitted light I6 is emitted from the pixel 10B, and the transmitted light I7 is emitted from the third pixel 10C. Therefore, when the back surface 100R of the display body 100 is viewed from the back surface side, the hue color corresponding to the wavelength range of the transmitted light I5 is visually recognized in the first display area 110A, and the wavelength of the transmitted light I6 is displayed in the second display area 110B. The hue color corresponding to the region is visually recognized, and the hue color corresponding to the wavelength region of the transmitted light I7 is visually recognized in the third display region 110C. Since the wavelength range of the transmitted light I5, the wavelength range of the transmitted light I6, and the wavelength range of the transmitted light I7 are different from each other, the first display area 110A, the second display area 110B, and the third display area 110C have different hues. Looks like the color of.

Therefore, even when the back surface transmission observation is performed by observing the back surface 100R from the back surface side of the display body 100 in a state where the incident light I1 is irradiated from the outside of the display body 100 toward the front surface 100F, the first display regions having different colors are used. An image composed of 110A, a second display area 110B, and a third display area 110C is visually recognized.

Further, since the wavelength range of the reflected light I2 and the wavelength range of the transmitted light I5 are different, the first display area 110A is obtained when the display body 100 is viewed from the front surface side and when the display body 100 is viewed from the back surface side. The hue of the color visually recognized is different. The color seen from the back surface side is a color corresponding to the complementary color of the color seen from the front surface side. Similarly, the hue of the color visually recognized in the second display area 110B differs between when the display body 100 is viewed from the front surface side and when the display body 100 is viewed from the back surface side, and is visually recognized in the third display area 110C. The hue of the color to be produced is also different.

As described above, according to the display body 100 of the first embodiment, the wavelength selectivity of the reflected light emitted from each pixel 10A, 10B, 10C is enhanced, so that the display body 100 is visually recognized in each display area 110A, 110B, 110C. The sharpness and brightness of the colors are enhanced. Therefore, as a result of increasing the visibility of the image formed by the display body 100, the difficulty of forgery and the design of the article provided with the display body 100 are increased.

Further, in the front surface reflection observation and the back surface transmission observation, images of different colors are visually recognized on the display body 100. Therefore, in the article provided with the display body 100, the difficulty of counterfeiting and the designability are further enhanced. In addition, it is easy to identify the front and back sides of the display body 100. Further, in the display body 100 of the first embodiment, since a flexible base material 11 such as a resin film can be used, it is possible to realize the display body 100 having a high degree of freedom in shape deformation. Is.

[Manufacturing method of display body]
The method for manufacturing the display body 100 described above will be described with reference to FIGS. 4 to 6.
As shown in FIG. 4, when forming the pixel 10, first, a layer made of a low refractive index material is formed on the surface of the base material 11, and a concavo-convex structure is formed on the surface of this layer to form a concavo-convex structure layer. 20 is formed. The concave-convex structure layer 20 has a flat portion 20a extending along the base material 11 and a plurality of convex portions 20b protruding from the flat portion 20a, and also has a plurality of concave portions 20c which are portions located between the convex portions 20b. .. The plurality of convex portions 20b are arranged at equal intervals in sub-wavelength periods and extend in a band shape in one direction. The plurality of concave portions 20c are arranged in the same pattern as the plurality of convex portions 20b, and the area of the plurality of convex portions 20b and the area of the plurality of concave portions 20c are equal to each other when viewed from the direction facing the surface of the base material 11. ..

In the convex portion 20b and the concave portion 20c, the period Pt of the arrangement is the desired first period P1 and second period P2, and the width Dt1 of the convex portion 20b is set according to the wavelength range of the hue light to be visually recognized by the pixel 10. Is formed so that the desired first low element width Dl1 and the second high element width Dh2 are obtained, and the width Dt2 of the recess 20c is the desired first high element width Dh1 and the second low element width Dl2. That is, the width Dt1 of the convex portion 20b and the width Dt2 of the concave portion 20c are equal to each other. The height Ht of the convex portion 20b is formed so as to be larger than the desired first region thickness T1.

A known microfabrication technique such as a nanoimprint method or a dry etching method is used to form the uneven structure. Among them, the nanoimprint method is preferable because fine convex portions 20b and concave portions 20c can be easily formed.

For example, when an ultraviolet curable resin is used as a low refractive index material and the concave-convex structure layer 20 is formed by an optical nanoimprint method, first, the surface of the base material 11 is coated with the ultraviolet curable resin. Next, a synthetic quartz mold, which is a concave plate having inverted unevenness of unevenness composed of convex portions 20b and concave portions 20c to be formed, is pressed against the surface of the coating layer made of an ultraviolet curable resin, and the coating layer and the concave plate are pressed. Irradiate with ultraviolet rays. Subsequently, the intaglio is released from the cured ultraviolet curable resin. As a result, the unevenness of the intaglio is transferred to the ultraviolet curable resin to form the convex portion 20b and the concave portion 20c, and the convex portion 20b and the concave portion 20c and the base material 11 are made of an ultraviolet curable resin. A flat portion 20a is formed as a residual film.

Next, as shown in FIG. 5, a high refractive index layer 21 made of a high refractive index material is formed on the surface of the concave-convex structure layer 20. As a method for forming the high refractive index layer 21, a known film forming technique such as a vacuum vapor deposition method is used. The high refractive index layer 21 is formed on the convex portion 20b and the concave portion 20c. That is, the high refractive index layer 21 includes a first layered portion 21a located on the concave portion 20c and a second layered portion 21b located on the convex portion 20b.

Since the width Dt1 of the convex portion 20b and the width Dt2 of the concave portion 20c in the concave-convex structure layer 20 are equal to each other, the width Ds1 of the first layered portion 21a and the width Ds2 of the second layered portion 21b are equal. Further, the period of the arrangement of the first layered portion 21a and the period of the arrangement of the second layered portion 21b are the period Pt, which are equal to each other. The thickness of the high refractive index layer 21 is, that is, the thickness Ts1 of the first layered portion 21a and the thickness Ts2 of the second layered portion, and these thicknesses are equal. The thickness of the high refractive index layer 21 is smaller than the height Ht of the convex portion 20b, and is formed so as to have a desired first region thickness T1 and second region thickness T2. That is, the first layered portion 21a and the second layered portion 21b form a sub-wavelength lattice having the same pattern as each other.

Next, as shown in FIG. 6, it is a layer made of the same low refractive index material as the material for forming the uneven structure layer 20 so as to cover the surface of the structure composed of the uneven structure layer 20 and the high refractive index layer 21. The embedded layer 22 is formed to fill the unevenness of the structure up to the second layer-shaped portion 21b. The embedded layer 22 includes a flat portion 22a, a plurality of convex portions 22b, and a concave portion 22c located between the convex portions 22b. The convex portion 22b fills the space between the convex portions 20b and the second layer-shaped portion 21b on the first layer-shaped portion 21a. The flat portion 22a is located on the second layered portion 21b and extends in the direction along the surface of the base material 11. The flat portion 22a and the convex portion 22b are connected so that the convex portion 22b protrudes from the flat portion 22a toward the base material 11.

The period of the convex portion 22b coincides with the period Pt of the convex portion 20b in the concave-convex structure layer 20, the width of the convex portion 22b coincides with the width Dt2 of the concave portion 20c, and the width of the concave portion 22c corresponds to the width Dt1 of the convex portion 20b. Matches with. The height of the convex portion 20b is larger than the thickness of the high refractive index layer 21.

As a method for forming the embedded layer 22, known film forming techniques such as various coating methods are used. For example, when an ultraviolet curable resin is used as the low refractive index material, first, the surface of the structure is coated with the ultraviolet curable resin. Next, a flat plate having releasability is pressed against the surface of the coating layer made of an ultraviolet curable resin, and the coating layer is irradiated with ultraviolet rays. Subsequently, the flat plate is released from the cured ultraviolet curable resin. Therefore, when an ultraviolet curable resin is used, the planographic plate must be made of a material that transmits ultraviolet rays.

As a result, the pixel 10 is formed. The flat portion 20a of the concave-convex structure layer 20 is the first low refractive index region 12. The first lattice region 13 is composed of the first layered portion 21a of the high refractive index layer 21 and the portion of the convex portion 20b of the concave-convex structure layer 20 adjacent to the first layered portion 21a, and the first layered portion 21a is formed. The first high refractive index portion 13a, and the portion of the convex portion 20b adjacent to the first layered portion 21a is the first low refractive index portion 13b. A second portion of the convex portion 20b of the concave-convex structure layer 20 that extends beyond the first layered portion 21a and a portion of the convex portion 22b of the embedded layer 22 that is adjacent to the convex portion 20b of the concave-convex structure layer 20. The low refractive index region 14 is configured.

The second lattice region 15 is composed of the second layered portion 21b of the high refractive index layer 21 and the portion of the convex portion 22b of the embedded layer 22 adjacent to the second layered portion 21b, and the second layered portion 21b is the second layer. 2 The high refractive index portion 15a, and the portion of the convex portion 22b adjacent to the second layered portion 21b is the second low refractive index portion 15b. The flat portion 22a of the embedded layer 22 is the third low refractive index region 16.

In the pixel 10 manufactured by such a manufacturing method, the first low refractive index region 12 and the first low refractive index portion 13b of the first lattice region 13 are continuous, and the first low refractive index portion 13b and the second In the low refractive index region 14, the portion adjacent to the first low refractive index portion 13b is continuous, and the first low refractive index region 12, the first low refractive index portion 13b, and the second low refractive index region 14 are continuous. Among them, the portion adjacent to the first low refractive index portion 13b is one structure. Further, in the second low refractive index region 14, the portion of the second lattice region 15 adjacent to the second low refractive index portion 15b and the second low refractive index portion 15b are continuous, and the second low refractive index portion 15b And the third low refractive index region 16 are continuous, a portion of the second low refractive index region 14 adjacent to the second low refractive index portion 15b, a second low refractive index portion 15b, and a third low refractive index. The region 16 is one structure.

As described above, in the pixel 10, the intensity of the reflected light is increased by emitting the light in the wavelength region enhanced in the first lattice region 13 and the light in the wavelength region enhanced in the second lattice region 15. growing. Therefore, for example, when the pixel 10 is formed by using the nanoimprint method without requiring precise control of the thickness of the layer in contact with the first lattice region 13 and the second lattice region 15, the thickness of the residual film is formed. It is possible to manufacture the pixel 10 that emits reflected light having high wavelength selectivity without requiring precise control of the above. Therefore, the display body 100 can be easily manufactured.

Further, since the display body 100 can be formed by a manufacturing method that combines an optical nanoimprint method and a vacuum vapor deposition method, it is suitable for manufacturing by a roll-to-roll method. Therefore, the configuration of the display body 100 is also suitable for mass production.

Here, between the first pixel 10A, the second pixel 10B, and the third pixel 10C, the base material 11, the first low refractive index region 12, the first lattice region 13, the second low refractive index region 14, and the second Each of the lattice region 15 and the third low refractive index region 16 is continuous. That is, the first pixel 10A, the second pixel 10B, and the third pixel 10C have a common base material 11, a concavo-convex structure layer 20 that is mutually continuous between these pixels, and mutual use between these pixels. It has a continuous embedded layer 22.

The concavo-convex structure layer 20 in each of the first pixel 10A, the second pixel 10B, and the third pixel 10C uses, for example, the nanoimprint method to change the concavo-convex cycle at the portion corresponding to each pixel 10A, 10B, 10C. It can be formed at the same time by using a synthetic quartz mold. Further, the high refractive index layer 21 and the embedded layer 22 can also simultaneously form portions corresponding to the pixels 10A, 10B, and 10C. Therefore, the pixels 10A, 10B, and 10C that exhibit different colors can be easily formed.

When the high refractive index layer 21 is formed by using the vacuum vapor deposition method, the high refractive index material may also adhere to the side surface of the convex portion 20b of the concave-convex structure layer 20. As a result, as shown in FIG. 7, the second low refractive index region 14 is the end of the first high refractive index portion 13a and the second high refractive index portion 15a that are adjacent to each other when viewed from the direction along the first direction. A third high refractive index portion 17 extending in the thickness direction of the second low refractive index region 14 is included so as to connect the portions. The third high refractive index section 17 does not have to completely connect the first high refractive index section 13a and the second high refractive index section 15a, and the third high refractive index section 17 and the first high refractive index section 17 do not have to be completely connected. The rate section 13a and the second high refractive index section 15a may be separated from each other.

Even when the third high refractive index portion 17 is present, the volume ratio of the third high refractive index portion 17 in the second low refractive index region 14 is very small, and in the second low refractive index region 14, The part composed of low refractive index material is dominant. Therefore, the refractive index of the second low refractive index region 14 is slightly larger than the refractive index of each of the first low refractive index region 12 and the third low refractive index region 16, but the first lattice region 13 and the second It is sufficiently smaller than each refractive index of the lattice region 15. Therefore, a structure suitable for the waveguide mode resonance phenomenon is realized in which each of the first lattice region 13 and the second lattice region 15 is sandwiched between regions having a lower refractive index than these regions.

[Transformation example of display body]
In the above-mentioned production method, the concave-convex structure layer 20 may be formed by the nanoimprint method using a thermosetting resin or a thermoplastic resin instead of the ultraviolet curable resin. When a thermosetting resin is used, the irradiation of ultraviolet rays may be changed to heating, and when a thermoplastic resin is used, the irradiation of ultraviolet rays may be changed to heating and cooling.

However, when the concave-convex structure layer 20 is formed by using the thermoplastic resin, a material different from the thermoplastic resin is used in order to prevent the concave-convex structure layer 20 from being heated and deformed when the embedded layer 22 is formed. It is preferable to form the embedded layer 22.

For example, as shown in FIG. 8, the concave-convex structure layer 20 may be formed of a thermoplastic resin, and the embedded layer 22 may be formed of an ultraviolet curable resin. In this case, the refractive index of the low refractive index material constituting the concave-convex structure layer 20 and the refractive index of the low refractive index material constituting the embedded layer 22 may be different from each other, and the refractive index of each low refractive index material may be different from each other. The index may be lower than the refractive index of the high refractive index material constituting the high refractive index layer 21.

When the refractive index of the low refractive index material constituting the concave-convex structure layer 20 and the refractive index of the low refractive index material constituting the embedded layer 22 are different from each other, in the manufactured pixel 10, the first low refractive index region 12 The refractive indexes of the second low refractive index region 14 and the third low refractive index region 16 are different from each other. Further, the second low refractive index region 14 has a structure in which strip-shaped portions made of materials having different refractive indexes extend along the second direction and are alternately arranged along the third direction.

Not only when the concave-convex structure layer 20 is formed of a thermoplastic resin and the embedded layer 22 is formed of a material different from the thermoplastic resin, the refractive index of the low-refractive index material constituting the concave-convex structure layer 20 and the embedding The refractive indexes of the low refractive index materials constituting the layer 22 may be different from each other. In short, the refractive index of the low refractive index material constituting each of the concave-convex structure layer 20 and the embedded layer 22 may be lower than the refractive index of the high refractive index material constituting the high refractive index layer 21. Then, in the manufactured pixel 10, the first low refractive index region 12, the second low refractive index region 14, and the third low refractive index are higher than each of the refractive indexes of the first lattice region 13 and the second lattice region 15. It suffices if each of the refractive indexes of the refractive index region 16 is low.

Further, as shown in FIG. 9, the base material 11 and the concave-convex structure layer 20 may be one continuous structure. That is, the uneven structure layer 20 is formed by forming the uneven structure on the surface of the base material 11 made of the low refractive index material. For example, a sheet made of a thermoplastic resin may be used as the base material 11 to form an uneven structure on the surface of the base material 11, or a substrate made of synthetic quartz may be used as the base material 11 to form a surface of the base material 11. An uneven structure may be formed on the surface. A known technique such as a dry etching method may be used for forming the uneven structure on the synthetic quartz substrate. In this case, in the manufactured pixel 10, the base material 11 and the first low refractive index region 12 are continuous with each other.

As described above, according to the first embodiment, the effects listed below can be obtained.
(1) When light is incident on the lattice regions 13 and 15 in the pixel 10, a waveguide mode resonance phenomenon occurs in the lattice regions 13 and 15. Then, the wavelength region of the light that resonates in the first lattice region 13 and the wavelength region of the light that resonates in the second lattice region 15 coincide with each other. Therefore, since the light in the wavelength region enhanced in each of the two lattice regions 13 and 15 is obtained as the reflected light, the light emitted from the pixel 10 as the reflected light is compared with the configuration having only one lattice region. The strength of is increased. That is, the wavelength selectivity of the light emitted from the pixel 10 is enhanced. Therefore, since the sharpness and brightness of the color visually recognized in the display area 110 are enhanced, the visibility of the image formed by the display body 100 is enhanced, and as a result, the difficulty of forgery and the design, that is, the appearance of the display body 100 is enhanced. The function expressed by is enhanced.

Further, in the front surface reflection observation and the back surface transmission observation, images of different colors are visually recognized on the display body 100. Therefore, in the article provided with the display body 100, the difficulty of counterfeiting and the designability are further enhanced. In addition, it is easy to identify the front and back sides of the display body 100.

(2) Since the display body 100 includes pixels 10A, 10B, and 10C having different lattice periods of the sub-wavelength lattice, these pixels 10A, 10B, and 10C are positioned in each of the front surface reflection observation and the back surface transmission observation. Colors having different hues are visually recognized in the display areas 110A, 110B, and 110C. Therefore, it is possible to express various images by these areas. Further, since the difference in the visually recognized hue is realized by the difference in the lattice period of the sub-wavelength lattice, the difference in the pixel manufacturing process due to the difference in color is small, and the display body 100 can be easily manufactured.

(3) It is composed of a step of forming a concavo-convex structure layer 20 made of a low refractive index material, a step of forming a high refractive index layer 21 on the surface of the concavo-convex structure layer 20, and a step of forming the concavo-convex structure layer 20 and a high refractive index layer 21. The pixel 10 is formed by the step of forming the embedded layer 22 made of a low refractive index material on the surface of the structure. Therefore, the wavelength selectivity of the reflected light emitted from the pixel 10 is enhanced without requiring precise control of the film thickness of the layer in contact with the sub-wavelength grid, so that the display is more difficult to counterfeit and has improved design. The body 100 can be easily manufactured.

(4) In particular, in a manufacturing method in which a resin is used as a low refractive index material and a concave plate is pressed against a coating layer made of the resin to form the concave-convex structure layer 20 by curing the resin, the concave-convex structure layer 20 is formed by using the nanoimprint method. Therefore, the concavo-convex structure layer 20 having fine concavities and convexities can be preferably and easily formed.

(5) The first low refractive index region 12, the first low refractive index portion 13b, and the portion of the second low refractive index region 14 adjacent to the first low refractive index portion 13b are mutually continuous 1 Two structures, the third low refractive index region 16, the second low refractive index portion 15b, and the portion of the second low refractive index region 14 adjacent to the second low refractive index portion 15b are mutually connected. In the configuration of one continuous structure, each of the parts of the structure can be manufactured in one step by using the above-mentioned manufacturing method, so that the display body 100 can be easily manufactured. Is.

(6) In a configuration in which the refractive index difference between each of the above structures and the first high refractive index portion 13a and the second high refractive index portion 15a is larger than 0.2, the waveguide mode is set in the lattice regions 13 and 15 respectively. The resonance phenomenon is likely to occur favorably, and the intensity of the reflected light from each of the lattice regions 13 and 15 is further enhanced. Therefore, the difficulty of counterfeiting and the designability are further enhanced.

(7) The low refractive index material constituting each of the above structures is any of an ultraviolet curable resin, a thermosetting resin, and a thermoplastic resin, and the first high refractive index portion 13a and the second high refractive index When the material constituting the portion 15a contains an inorganic compound, the waveguide mode resonance phenomenon is likely to occur favorably in the lattice regions 13 and 15, and the intensity of the reflected light from the lattice regions 13 and 15 is further increased. Be done. Therefore, the difficulty of counterfeiting and the designability are further enhanced. Further, it is possible to reduce the material cost required for manufacturing the display body 100 and to apply a simple manufacturing method such as the nanoimprint method.

(8) The second low refractive index region 14 is located between the ends of the first high refractive index portion 13a and the second high refractive index portion 15a, which are adjacent to each other when viewed from the direction along the first direction. In the configuration including the third high refractive index portion 17 extending along the thickness direction of the refractive index region 14, the high refractive index portions 13a and 15a can be formed by using the vacuum vapor deposition method, which is suitable for the sub-wavelength lattice. It can be formed. Even in this case, the configuration of the second low refractive index region 14 for causing the waveguide mode resonance phenomenon is preferably realized.

(Second Embodiment)
A display body and a second embodiment of a method for manufacturing the display body will be described with reference to FIGS. 10 to 13. The second embodiment has a different pixel structure as compared with the first embodiment. Hereinafter, the differences between the second embodiment and the first embodiment will be mainly described, and the same reference numerals will be given to the same configurations as those of the first embodiment, and the description thereof will be omitted.

[Pixel composition]
The configuration of the pixels included in the display body of the second embodiment will be described with reference to FIGS. 10 and 11. As shown in FIG. 10, the pixel 10 includes the first low refractive index region 12, the first lattice region 13, the second low refractive index region 14, the second lattice region 15, and the second lattice region 15 described in the first embodiment. It is provided with two resonance structure portions 18, which are structures composed of three low refractive index regions 16.

The first resonance structure portion 18A and the second resonance structure portion 18B, which are the two resonance structure portions 18, are adjacent to each other in the first direction, and the two resonance structure portions 18A and 18B are sandwiched between the two base materials 11. It has been. In other words, the pixel 10 of the second embodiment has a structure in which two pixels having the configuration of the first embodiment are joined so that the third low refractive index regions 16 face each other. That is, the pixel 10 of the second embodiment has four sub-wavelength grids arranged with a gap in the first direction, and these sub-wavelength grids have a structure embedded in a low refractive index material. The side of the other base material 11 with respect to one base material 11 is the front surface side of the display body 100, and the side of the other base material 11 with respect to the other base material 11 is the back surface side of the display body 100.

In the two resonance structure portions 18A and 18B, the extending directions of the high refractive index portions 13a and 15a are the same. That is, all the first high refractive index portions 13a and the second high refractive index portion 15a included in the pixel 10 extend along the second direction, and all the first low refractive index portions 13b and the second low included in the pixel 10. The refractive index portion 15b also extends along the second direction. Then, in each of the four lattice regions 13 and 15 of the pixel 10, the high refractive index portions 13a and 15a and the low refractive index portions 13b and 15b are alternately arranged along the third direction. That is, the arrangement directions of the sub-wavelength grids are the same for the four sub-wavelength grids of the pixel 10.

The first high refractive index portion 13a of the first resonance structure portion 18A may overlap with the first high refractive index portion 13a of the second resonance structure portion 18B when viewed from the direction along the first direction. It may overlap with the second high refractive index portion 15a of the second resonance structure portion 18B, or may overlap with a part of the first high refractive index portion 13a and a part of the second high refractive index portion 15a of the second resonance structure portion 18B. It may overlap.

The first resonance structure portion 18A and the second resonance structure portion 18B may share a low refractive index region at their boundary portions. For example, in the example shown in FIG. 10, the third low refractive index region 16 included in the first resonance structure portion 18A and the third low refractive index region 16 included in the second resonance structure portion 18B are continuous, and these There are no region boundaries.

Within one resonance structure portion 18, the first period P1 of the first lattice region 13 and the second period P2 of the second lattice region 15 are the same, and this period is the structural period Pk of the resonance structure portion 18. ..

The structural period Pk of the first resonance structure portion 18A and the structural period Pk of the second resonance structure portion 18B may be the same as shown in FIG. 10 or different from each other as shown in FIG. Good.

In the form in which the two resonance structure portions 18A and 18B have the same structural period Pk, the patterns of the four sub-wavelength lattices included in the pixel 10 are all the same, and the resonance structure portions 18A and 18B have high element widths Dh1 and Dh2. Are all equal, and the region thicknesses T1 and T2 are all equal. Further, in the form in which the two resonance structure portions 18A and 18B have different structural periods Pk, the pattern of the four sub-wavelength lattices included in the pixel 10 is different for each resonance structure portion 18A and 18B. That is, the high element widths Dh1 and Dh2 are different for each of the resonance structure portions 18A and 18B. The region thicknesses T1 and T2 may all be the same, or may be different for each of the resonance structure portions 18A and 18B.

[Action of display body]
In the configuration in which the two resonance structure portions 18A and 18B have the same structural period Pk, the wavelength ranges of the light causing resonance are the same in all of the four lattice regions 13 and 15 of the pixel 10. Therefore, when light is incident on the pixel 10 from the surface side of the display body 100, among the light in a specific wavelength range that is multiple-reflected in the upper grid region, the light that leaks from this grid region in the process of multiple reflection is , It enters the lattice region of the lower layer and multiple reflections occur, and this phenomenon is repeated for the number of lattice regions. As a result, the reflected light in a specific wavelength region enhanced in each of the four lattice regions 13 and 15 is emitted to the surface side of the display body 100. Therefore, as compared with the display body of the first embodiment, the intensity of the light in the specific wavelength range emitted from the display body 100 as the reflected light is higher, and the wavelength selectivity of the reflected light is further enhanced. As a result, in the display body 100, the visibility of the image is enhanced by increasing the sharpness and brightness of the colors visually recognized in the display areas 110A, 110B, and 110C by the surface reflection observation.

On the other hand, in the configuration in which the two resonance structure portions 18A and 18B have different structural periods Pk, the wavelength range of light that causes resonance in the lattice regions 13 and 15 of the first resonance structure portion 18A and the second resonance structure portion The wavelength regions of light that resonate in the lattice regions 13 and 15 of 18B are different from each other. Therefore, when light is incident on the pixel 10 from the surface side of the display body 100, the light in a specific wavelength range is multiple-reflected in the lattice regions 13 and 15 of the resonance structure portion 18 in the upper layer, and the light is not multiple-reflected. Light passes through the resonance structure portion 18 and enters the resonance structure portion 18 of the lower layer, and light having a wavelength range different from that of the resonance structure portion 18 of the upper layer is emitted from each lattice region 13 of the resonance structure portion 18 of the lower layer. Multiple reflection is performed at 15. As a result, on the surface side of the display body 100, the light in the first wavelength region enhanced by the lattice regions 13 and 15 of the first resonance structure portion 18A and the lattice region 13 of the second resonance structure portion 18B The reflected light including the light in the second wavelength region enhanced at 15 and 15 is emitted from the pixel 10.

Then, on the back surface side of the display body 100, among the wavelength ranges included in the light incident on the display body 100, the wavelength range excluding the first wavelength range and the second wavelength range emitted as the reflected light. Light is emitted from the pixel 10 as transmitted light. According to such a configuration, it is possible for the pixel 10 to widen the wavelength range included in the reflected light and narrow the wavelength range included in the transmitted light while increasing the intensity of the reflected light. Therefore, the degree of freedom in adjusting the hue observed as reflected light or transmitted light can be increased by setting the structural period Pk in the resonance structure portions 18A and 18B.

Then, in the first pixel 10A, the second pixel 10B, and the third pixel 10C, the combination of the structural period Pk of the first resonance structure portion 18A and the structural period Pk of the second resonance structure portion 18B is different from each other. .. That is, the combination of the structural period Pk of the first resonance structure portion 18A in the first pixel 10A and the structural period Pk of the second resonance structure portion 18B, and the structural period Pk of the first resonance structure portion 18A in the second pixel 10B. In the combination with the structural period Pk of the second resonance structure portion 18B, at least one of the structural period Pk of the first resonance structure portion 18A and the structural period Pk of the second resonance structure portion 18B is different. The same applies to the combination of the structural period Pk in the second pixel 10B and the third pixel 10C, and the combination of the structural period Pk in the first pixel 10A and the third pixel 10C.

Due to such a configuration, the first pixel 10A, the second pixel 10B, and the third pixel 10C have different wavelength ranges of light emitted as reflected light and different wavelength ranges of light emitted as transmitted light. ing. As a result, in each of the front surface reflection observation and the back surface transmission observation, the first display area 110A, the second display area 110B, and the third display area 110C appear to have different hues from each other. According to such a configuration, the degree of freedom of adjusting the hue of the image visually recognized in the front surface reflection observation and the back surface transmission observation is increased.

[Manufacturing method of display body]
A method of manufacturing the display body 100 of the second embodiment will be described with reference to FIGS. 12 and 13. First, in the production of the pixel 10 of the second embodiment, the concave-convex structure layer 20 and the high refractive index layer 21 are sequentially formed on the base material 11 as in the first embodiment.

Subsequently, as shown in FIG. 12, the two concave-convex structures 31, which are structures composed of the base material 11, the concave-convex structure layer 20, and the high-refractive index layer 21, face each other so that the high-refractive index layers 21 face each other. Then, as shown in FIG. 13, these uneven structures 31 are joined by filling the region between the two concave-convex structures 31 with a low refractive index material. As a result, the pixel 10 is formed.

As shown in FIG. 13, the portion formed between the two uneven structures 31 by embedding with a low refractive index material is the embedding layer 22. Similar to the first embodiment, if the low refractive index material constituting the embedded layer 22 is a material having a lower refractive index than the high refractive index material constituting the high refractive index layer 21, the concave-convex structure layer 20 is formed. It may be a material different from the material. Further, in the two concave-convex structures 31, the low-refractive index material forming the concave-convex structure layer 20 and the high-refractive index material forming the high refractive index layer 21 may be different from each other.

In a state where the two concave-convex structures 31 face each other, the first layered portions 21a may face each other, or the first layered portion 21a in one concave-convex structure 31 and the second concave-convex structure 31 in the other concave-convex structure 31. The two-layered portion 21b may face each other. Alternatively, the first layered portion 21a in one concave-convex structure 31 may face a part of the first layered portion 21a and a part of the second layered portion 21b in the other concave-convex structure 31.

For example, by joining the concavo-convex structure 31 having the same period Pt of the convex portion 20b as the two concavo-convex structures 31, the pixel 10 in which the two resonance structure portions 18A and 18B have the same structural period Pk is formed. it can. Further, for example, as two concave-convex structures 31, pixels 10 in which the two resonance structure portions 18A and 18B have different structural periods Pk are formed by joining the concave-convex structures 31 having different periodic Pts of the convex portions 20b. it can.

The pixel 10 may include three or more resonance structure portions 18 arranged in the first direction. In a configuration in which the pixels 10 include a plurality of resonance structure portions 18, if the structural period Pk in these resonance structure portions 18 is the same, the larger the number of resonance structure portions 18, the higher the intensity of the reflected light. Further, the plurality of resonance structure portions 18 may include a resonance structure portion 18 having the same structural period Pk and a resonance structure portion 18 having different structural periods Pk. According to such a configuration, it is possible to finely adjust the colors of the reflected light and the transmitted light emitted from the pixel 10.

In manufacturing the pixel 10 having three or more resonance structure portions 18, the base material 11 of the concave-convex structure 31 and the concave-convex structure layer 20 are formed of a material capable of peeling the base material 11 from the concave-convex structure layer 20. Then, after the two concave-convex structures 31 are joined by the low-refractive index material, one base material 11 is peeled off, and the exposed concave-convex structure layer 20 and the other uneven structure 31 further form a low-refractive index material. By repeating the sandwiching and joining, the pixel 10 having 6 or more sub-wavelength grids is formed.

As described above, according to the second embodiment, the following effects can be obtained in addition to the effects of (1), (3) to (8) of the first embodiment.
(9) According to the configuration in which the pixels 10 include a plurality of resonance structure portions 18 arranged in the first direction, since the pixels 10 include the lattice regions 13 and 15 having four or more pixels, the reflected light emitted from the pixels 10 It is possible to further enhance the wavelength selectivity and increase the degree of freedom in adjusting the wavelength range included in the reflected light and the transmitted light. Therefore, it is possible to increase the visibility of the image formed by the display body 100 and increase the degree of freedom in adjusting the hue of the image visually recognized by the display body 100.

(10) According to the configuration in which the structural period Pk of the first resonance structure portion 18A and the structural period Pk of the second resonance structure portion 18B are different from each other, resonance occurs in the lattice regions 13 and 15 of the first resonance structure portion 18A. The wavelength range of the light that causes resonance and the wavelength range of the light that causes resonance in the lattice regions 13 and 15 of the second resonance structure portion 18B are different from each other. Therefore, when light is incident on the pixel 10, the light in the first wavelength region enhanced in the lattice regions 13 and 15 of the first resonance structure portion 18A and the light in the second resonance structure portion 18B are contained from the pixel 10. The reflected light including the light in the second wavelength region enhanced in the lattice regions 13 and 15 is emitted. Further, among the wavelength ranges included in the incident light of the pixel 10, the light in the wavelength range excluding the first wavelength range and the second wavelength range emitted as the reflected light is emitted from the pixel 10 as transmitted light. .. Therefore, in the pixel 10, it is possible to expand the wavelength range included in the reflected light and narrow the wavelength range included in the transmitted light while increasing the intensity of the reflected light. Therefore, it is possible to increase the degree of freedom in adjusting the hue observed as reflected light or transmitted light by setting the lattice period of the sub-wavelength lattice of each of the resonance structure portions 18A and 18B, and the display body 100 can display the display body 100. It is possible to increase the degree of freedom in adjusting the hue of the image to be visually recognized.

(11) In each pixel 10A, 10B, 10C, in a configuration in which the combination of the structural period Pk of the first resonance structure portion 18A and the structural period Pk of the second resonance structure portion 18B is different from each other, the first pixel 10A and the second pixel 10A and the second The pixel 10B and the third pixel 10C have different wavelength ranges of light emitted as reflected light and different wavelength ranges of light emitted as transmitted light. As a result, in each of the front surface reflection observation and the back surface transmission observation, the first display area 110A, the second display area 110B, and the third display area 110C appear to have different hues from each other. According to such a configuration, the degree of freedom of adjusting the hue of the image visually recognized in the front surface reflection observation and the back surface transmission observation is increased.

(12) The pixel 10 is formed by having two concave-convex structures 31 face each other so that the high-refractive index layers 21 face each other, and filling a region between the two concave-convex structures 31 with a low-refractive index material. To. According to this, the pixel 10 including the plurality of resonance structure portions 18 can be easily formed. Therefore, the display body 100 can be easily manufactured.

(Third Embodiment)
A display body and a third embodiment of a method for manufacturing the display body will be described with reference to FIGS. 14 and 15. In the third embodiment, the arrangement directions of the sub-wavelength lattices in the two resonance structures are different from those in the second embodiment. Hereinafter, the differences between the third embodiment and the second embodiment will be mainly described, and the same reference numerals will be given to the same configurations as those of the second embodiment, and the description thereof will be omitted. 14 and 15 are views showing a part of the pixel 10, and are composed of a portion made of a high refractive index material and a low refractive index material in order to make the structure of the pixel 10 easy to understand. Dots with different densities are attached to the parts shown.

[Pixel composition]
As shown in FIG. 14, the pixel 10 included in the display body of the third embodiment includes two resonance structure portions 18A and 18B adjacent to each other in the first direction, as in the second embodiment. However, in the third embodiment, the respective element portions of the lattice regions 13 and 15 of the first resonance structure portion 18A, that is, the extending directions of the high refractive index portions 13a and 15a and the low refractive index portions 13b and 15b, respectively. , The extending directions of the respective element portions of the lattice regions 13 and 15 of the second resonance structure portion 18B are different from each other. That is, the direction in which the element portions are arranged in the lattice regions 13 and 15 is different for each resonance structure portion 18. In other words, the arrangement direction of the sub-wavelength lattice included in the first resonance structure portion 18A and the arrangement direction of the sub-wavelength lattice included in the second resonance structure portion 18B are different from each other.

The patterns of the four sub-wavelength lattices included in the pixel 10 are in agreement with each other, the periods P1 and P2 are all equal in the resonance structure portions 18A and 18B, the high element widths Dh1 and Dh2 are all equal, and the region thickness T1. , T2 are all equal.

FIG. 15 is a diagram showing the pixel 10 shown in FIG. 14 divided into regions extending in a direction along the surface of the base material 11. Note that FIG. 15 is a diagram for clearly showing the arrangement of each element portion in the two resonance structure portions 18A and 18B, and the boundary of each region divided in FIG. 15 constitutes the pixel 10. It does not indicate the boundaries of the structure.

As shown in FIG. 15, the high refractive index portions 13a, 15a and the low refractive index portions 13b, 15b of the first resonance structure portion 18A extend along the second direction and are aligned along the third direction. On the other hand, the high refractive index portions 13a and 15a and the low refractive index portions 13b and 15b of the second resonance structure portion 18B extend along the third direction and are aligned along the second direction. That is, the extending direction of each element portion of the first resonance structure portion 18A and the extending direction of each element portion of the second resonance structure portion 18B are orthogonal to each other. In other words, the angle formed by the arrangement direction of the sub-wavelength lattice of the first resonance structure portion 18A and the arrangement direction of the sub-wavelength lattice of the second resonance structure portion 18B is 90 °.

[Action of display body]
When the sub-wavelength lattice is composed of high refractive index portions 13a and 15a extending in a band shape in one direction, light polarized in a specific direction is multiplely reflected and resonates in each of the lattice regions 13 and 15. It is emitted as reflected light. The specific direction depends on the arrangement direction of the sub-wavelength lattice. Since the arrangement directions of the sub-wavelength lattices are different between the first resonance structure portion 18A and the second resonance structure portion 18B, the lattice regions 13 and 15 of the first resonance structure portion 18A and the lattice regions of the second resonance structure portion 18B In 13 and 15, the polarization directions of the multiple reflected light are different from each other. Therefore, according to the pixel 10 of the third embodiment, the reflected light is efficiently emitted with respect to the incident light including the polarized light components in various directions, so that the intensity of the reflected light is further increased.

The incident light on the display body 100 is often light containing polarization components in various directions, such as general lighting and sunlight. Therefore, in the configuration including the pixels 10 of the third embodiment, in the display body 100 observed under external light, the sharpness and brightness of the colors visually recognized in the respective display areas 110A, 110B, 110C are improved. Highly effective.

[Manufacturing method of display body]
Similar to the second embodiment, the pixel 10 of the third embodiment has two concave-convex structures 31 which are a structure composed of a base material 11, a concave-convex structure layer 20, and a high-refractive index layer 21. The 21s are opposed to each other so as to face each other, and the region between the two concave-convex structures 31 is filled with a low refractive index material. Here, in the third embodiment, the extending direction of the high-refractive index layer 21 in one concave-convex structure 31 and the extending direction of the high-refractive index layer 21 in the other concave-convex structure 31 are orthogonal to each other. The concavo-convex structures 31 face each other and are joined by a low refractive index material.

The pixel 10 may include three or more resonance structure portions 18 arranged in the first direction, and the plurality of resonance structure portions 18 may include resonance structure portions 18 in which the extension directions of the element portions are different from each other. Just do it. Such a pixel 10 has an even number, that is, 2n (n is an integer of 3 or more) sub-wavelength lattices, and is the 2m-1st sub (m is an integer of 1 or more and n or less) from a position close to one of the base materials 11. In the wavelength lattice and the 2mth sub-wavelength lattice, the arrangement directions are the same and the lattice periods are the same. In other words, the pixel 10 has a structure in which pairs of sub-wavelength lattices having the same arrangement direction and lattice period are arranged in the first direction, and these sub-wavelength lattices are embedded in a low refraction material.

According to such a configuration, the polarization responsiveness of the pixel 10 can be improved by setting the arrangement direction of the sub-wavelength lattice for each resonance structure unit 18, setting the number of resonance structure units 18 having the same arrangement direction of the sub-wavelength lattice, and the like. It can also be adjusted. The plurality of resonance structure portions 18 may include resonance structure portions 18 having different patterns of sub-wavelength lattices.

In manufacturing the pixel 10 having three or more resonance structure portions 18, the base material 11 of the concave-convex structure 31 and the concave-convex structure layer 20 are formed of a material capable of peeling the base material 11 from the concave-convex structure layer 20. Then, after the two concave-convex structures 31 are joined by the low-refractive index material, one base material 11 is peeled off, and the exposed concave-convex structure layer 20 and the other uneven structure 31 further form a low-refractive index material. By repeating the sandwiching and joining, the pixel 10 having 6 or more sub-wavelength grids is formed.

As described above, according to the third embodiment, the following effects are obtained in addition to the effects of (1), (3) to (8) of the first embodiment and (9) and (12) of the second embodiment. Be done.
(13) Since the extending direction of the element portion of the first resonance structure portion 18A and the extending direction of the element portion of the second resonance structure portion 18B are different from each other, the lattice regions 13, 15 of the first resonance structure portion 18A In the lattice regions 13 and 15 of the second resonance structure unit 18B, among the light contained in the incident light, light polarized in different directions resonates and is emitted from the respective resonance structure units 18. Therefore, the reflected light is efficiently emitted from the incident light containing the polarized light components in various directions, so that the intensity of the reflected light is further increased. Therefore, in the display body 100 observed under external light containing polarization components in various directions, the effect of improving the sharpness and brightness of the colors visually recognized in the respective display areas 110A, 110B, 110C can be obtained highly. , The difficulty of counterfeiting and the design are further enhanced.

(14) In a configuration in which the extending direction of the element portion of the first resonance structure portion 18A and the extending direction of the element portion of the second resonance structure portion 18B are orthogonal to each other, the incident includes polarization components in various directions. The reflected light is emitted more efficiently with respect to the light. Moreover, the design and manufacture of the pixel 10 are easy.

[Modification example]
Each of the above embodiments can be modified and implemented as follows.
In the resonance structure portion 18 of the pixel 10 manufactured by the manufacturing method of each of the above embodiments, the second low refractive index portion 15b is located above the first high refractive index portion 13a, and the first low refractive index portion 13b is located. The second high refractive index portion 15a is located above the above.

That is, the arrangement pattern of the first high refractive index portion 13a matches the arrangement pattern of the second low refractive index portion 15b, and the arrangement pattern of the first low refractive index portion 13b is the second high refractive index portion 15a. Matches the placement pattern of. Then, in order to match the wavelength range of the light that causes resonance in the first lattice region 13 with the wavelength range of the light that causes resonance in the second lattice region 15, the first lattice region 13 and the second lattice region 15 are used. The lattice periods of the sub-wavelength lattices are the same, and the volume ratio of the plurality of first high refractive index portions 13a in the first lattice region 13 and the volume ratio of the plurality of second high refractive index portions 15a in the second lattice region 15 It is necessary that the ratio matches.

Satisfying these conditions is satisfied by the first high refractive index section 13a, the first low refractive index section 13b, the second high refractive index section 15a, and the second low refractive index section 15b, as in each of the above embodiments. The element portions have the same shape extending in a band shape in one common direction, and in each of the lattice regions 13 and 15, the high refractive index portions 13a and 15a and the low refractive index portions 13b and 15b extend thereof. It is easy if the configuration is arranged alternately in the direction orthogonal to the direction.

However, as long as the above conditions are satisfied, each element portion may have a shape different from the shape extending in a band shape. For example, as shown in FIG. 16, each of the first high refractive index portion 13a, the first low refractive index portion 13b, the second high refractive index portion 15a, and the second low refractive index portion 15b is in the first direction. It has the same rectangular shape such as a square when viewed from the direction along the line, and in each of the lattice regions 13 and 15, the high refractive index portions 13a and 15a and the low refractive index portions 13b and 15b are in the second direction and the third. The configuration may be arranged alternately along the respective directions. In such a case, as shown in FIG. 17, in the concave-convex structure layer 20, the convex portions 20b and the concave portions 20c are alternately arranged along each of the two directions orthogonal to each other, and the convex portions 20b and the concave portions are arranged in a plan view. 20c has the same rectangular shape such as a square.

According to the configuration shown in FIG. 16, even in one resonance structure portion 18, the reflected light is efficiently emitted with respect to the incident light including the polarizing components in various directions, so that the intensity of the reflected light is higher. Can be enhanced.

In each of the above embodiments, the display body 100 includes three types of pixels 10A, 10B, and 10C as pixels 10, but the number of types of pixels 10 that emit reflected light having different wavelengths is particularly limited. However, the number of types of the pixel 10 may be one or four or more. That is, the number of display regions included in the display body 100, that is, the number of regions exhibiting colors having different hues from each other is not particularly limited.

The display body 100 has a region having a configuration different from that of the pixel 10 of each embodiment, for example, a region having a structure in which only a flat layer made of a low refractive index material is laminated on the base material 11. May be good.

-In each of the above embodiments, pixels are illustrated as display elements, but the display elements are not limited to pixels, which are the minimum units of repetition for forming a raster image, and are regions connecting anchors for forming a vector image. It may be.

[Example]
The above-mentioned display body and its manufacturing method will be described with reference to specific examples.
<Manufacturing of display body>
First, a mold, which is an intaglio plate used in the optical nanoimprint method, was prepared. Specifically, since light having a wavelength of 365 nm was used as the light to be irradiated in the optical nanoimprint method, synthetic quartz that transmits light of this wavelength was used as the material for the mold. In forming the mold, first, a film made of Cr was formed on the surface of the synthetic quartz substrate by a sputtering method, and an electron beam resist pattern having a sub-wavelength lattice pattern was formed on the Cr film by an electron beam lithography method. The sub-wavelength grid pattern is a pattern in which band-shaped portions extending in one direction are arranged at equal intervals. The resist used was a positive type, and the film thickness was 150 nm.

The pattern drawn by the electron beam is a pattern in which four types of sub-wavelength grid patterns are arranged. This pattern is schematically shown in FIG. The first pattern SP1 is a pattern in which strip-shaped portions are arranged in the X direction with a period of 360 nm in a square region having a side of 3 cm. The second pattern SP2 is a pattern in which strip-shaped portions are arranged in the Y direction orthogonal to the X direction with a period of 360 nm in a square region having a side of 3 cm. The third pattern SP3 is a pattern in which strip-shaped portions are arranged in the X direction with a period of 396 nm in a square region having a side of 3 cm. The fourth pattern SP4 is a pattern in which strip-shaped portions are arranged in the Y direction with a period of 396 nm in a square region having a side of 3 cm.

Next, the Cr film in the region exposed from the resist was etched by plasma generated by applying a high frequency to a mixed gas of chlorine and oxygen. Subsequently, the synthetic quartz substrate in the region exposed from the resist and the Cr film was etched by the plasma generated by applying a high frequency to the hexafluorinated ethane gas. The depth of the synthetic quartz substrate etched by this was 200 nm. The remaining resist and Cr film were removed, and Optool HD-1100 (manufactured by Daikin Industries, Ltd.) was applied as a mold release agent to obtain a mold in which the above four sub-wavelength lattice patterns were formed.

Next, an ultraviolet curable resin was applied to the region on the mold where the four sub-wavelength lattice patterns were formed, and the mold surface was covered with a polyethylene terephthalate film that had been subjected to an easy-adhesion treatment. The ultraviolet curable resin is spread using a roller so as to spread over the entire area where the sub-wavelength lattice pattern is formed, and is irradiated with ultraviolet rays of 365 nm to cure the ultraviolet curable resin, and then the polyethylene terephthalate film is formed from the mold. Was peeled off. As a result, an inverted sub-wavelength lattice pattern of the above four sub-wavelength lattice patterns is formed on the surface of the ultraviolet curable resin, and the concavo-convex structure layer made of the ultraviolet curable resin and the base material which is a polyethylene terephthalate film are formed. A laminate was obtained. The region in which each of the four sub-wavelength grid patterns is formed corresponds to the pixel portion. The above steps were repeated to prepare two laminates of the concave-convex structure layer and the base material. The irradiation amount of ultraviolet rays at 365 nm was set to 50 mJ / cm ² .

Next, a high refractive index layer made of TiO ₂ was formed by forming a TiO ₂ film having a film thickness of 100 nm on the surfaces of the above two laminated bodies by a vacuum vapor deposition method. Subsequently, of the two laminates, the region where the sub-wavelength lattice pattern is located on the surface of one laminate is coated with an ultraviolet curable resin, and the coated ultraviolet curable resin is coated with the other laminate. The two laminates were faced to each other so that the surfaces were in contact with each other and the regions where the sub-wavelength lattice patterns having the same period were located overlapped. The ultraviolet curable resin was spread using a roller so as to spread over the entire surface in the region where the sub-wavelength lattice pattern was located, and was irradiated with ultraviolet rays of 365 nm to cure the ultraviolet curable resin to form an embedded layer. As a result, the display body of the example was obtained. The irradiation amount of ultraviolet rays at 365 nm was set to 50 mJ / cm ² .

<Evaluation of display>
When the reflection spectroscopy of the display body of the example was measured, a reflection spectrum having a center wavelength of about 530 nm was observed in the pixel having a sub-wavelength lattice having a period of 360 nm, and a pixel having a sub-wavelength lattice having a period of 396 nm was centered in about 620 nm. A reflection spectrum with wavelength was observed.

10 ... pixels, 10A ... 1st pixel, 10B ... 2nd pixel, 10C ... 3rd pixel, 11 ... base material, 12 ... first low refractive index region, 13 ... first lattice region, 13a ... first high refractive index Part, 13b ... 1st low refractive index part, 14 ... 2nd low refractive index region, 15 ... 2nd lattice region, 15a ... 2nd high refractive index part, 15b ... 2nd low refractive index part, 16 ... 3rd low Refractive index region, 17 ... 3rd high refractive index part, 18 ... resonance structure part, 18A ... first resonance structure part, 18B ... second resonance structure part, 20 ... uneven structure layer, 20a ... flat part, 20b ... convex part , 20c ... concave, 21 ... high refractive index layer, 21a ... first layered portion, 21b ... second layered portion, 22 ... embedded layer, 31 ... concavo-convex structure, 100 ... display body, 100F ... front surface, 100R ... back surface, 110 ... Display area, 110A ... First display area, 110B ... Second display area, 110C ... Third display area.

Claims (13)

A display body having a display element composed of a material that transmits incident light and having a front surface and a back surface.
The display element is
It has a plurality of first high refractive index portions constituting the first sub-wavelength lattice, and a plurality of first low refractive index portions having a refractive index lower than that of the first high refractive index portion, and is along the surface. A first lattice region in which the first high refractive index portion and the first low refractive index portion are alternately located in the direction,
A plurality of second high-refractive index sections made of the same material as the first high-refractive index section and forming a second sub-wavelength lattice, and a plurality of second high-refractive index sections having a lower refractive index than the second high-refractive index section. A second lattice region having two low refractive index portions, in which the second high refractive index portion and the second low refractive index portion are alternately located in a direction along the surface.
The first low refractive index region, the second low refractive index region, and the third low refractive index, each of which has a refractive index lower than each of the average refractive index of the first lattice region and the average refractive index of the second lattice region. With a rate area,
The first lattice region is sandwiched between the first low refractive index region and the second low refractive index region in the thickness direction of the display body.
The second lattice region is sandwiched between the second low refractive index region and the third low refractive index region in the thickness direction of the display body.
The lattice period of the first sub-wavelength lattice and the lattice period of the second sub-wavelength lattice are equal periods to each other.
The volume ratio of the plurality of first high refractive index portions in the first lattice region is the same as the volume ratio of the plurality of second high refractive index portions in the second lattice region.
When viewed from the direction facing the surface, the first high refractive index portion and the second low refractive index portion overlap, and the second high refractive index portion and the first low refractive index portion overlap .
The second low refractive index region has a first high refractive index portion and a third high refractive index portion made of the same material as the second high refractive index portion.
The third high refractive index portion is located between the ends of the first high refractive index portion and the second high refractive index portion, which are adjacent to each other when viewed from the direction facing the surface, and is the second low refractive index region. A display that extends along the thickness direction of . The display body includes a plurality of the display elements, and the plurality of display elements include a first display element and a second display element.
When viewed from the direction facing the surface, the display body includes a first display area in which the first display element is located and a second display area in which the second display element is located.
The lattice periods of the first sub-wavelength lattice and the second sub-wavelength lattice in the first display element and the lattice periods of the first sub-wavelength lattice and the second sub-wavelength lattice in the second display element are mutually exclusive. Different display body according to claim 1. A portion composed of the first lattice region, the second lattice region, the first low refractive index region, the second low refractive index region, and the third low refractive index region is a resonance structure portion.
The display body according to claim 1, wherein the display element includes a plurality of the resonance structure portions arranged along the thickness direction of the display body. The plurality of resonance structure portions include a first resonance structure portion and a second resonance structure portion, and have a lattice period of the first sub-wavelength lattice and the second sub-wavelength lattice of the first resonance structure portion. The display body according to claim 3, wherein a certain first structural period and a second structural period, which is a lattice period of the first sub-wavelength lattice and the second sub-wavelength lattice of the second resonance structure portion, are different from each other. .. The display body includes a plurality of the display elements, and the plurality of display elements include a first display element and a second display element.
When viewed from the direction facing the surface, the display body includes a first display area in which the first display element is located and a second display area in which the second display element is located.
The combination of the first structural period and the second structural period in the first display element and the combination of the first structural period and the second structural period in the second display element are the first structural period. The display body according to claim 4, wherein at least one of the second structural period is different from that of the second structural period. In each of the plurality of resonance structure portions, the plurality of first high refractive index portions, the plurality of first low refractive index portions, the plurality of second high refractive index portions, and the plurality of second low refractive index portions. Each element portion of the portion has a shape extending in a band shape in one direction.
The plurality of resonance structure portions include a first resonance structure portion and a second resonance structure portion.
The display according to claim 3, wherein the extending direction of the element portion of the first resonance structure portion and the extending direction of the element portion of the second resonance structure portion are different from each other. The extension direction of the element portion of the first resonance structure portion and the extension direction of the element portion of the second resonance structure portion are directions along the surface and are orthogonal to each other according to claim 6. The display body described. The first low refractive index region, the first low refractive index portion, and the portion of the second low refractive index region adjacent to the first low refractive index portion are one structure that is continuous with each other. Is the first structure that is
The third low refractive index region, the second low refractive index portion, and the portion of the second low refractive index region adjacent to the second low refractive index portion are one structure that is continuous with each other. The display body according to claim 1 or 2, which is the second structure. The difference in refractive index between the first structure, the first high refractive index portion, and the second high refractive index portion is larger than 0.2.
The display body according to claim 8, wherein the difference in refractive index between the second structure, the first high refractive index portion, and the second high refractive index portion is larger than 0.2. The material constituting the first structure is any one of an ultraviolet curable resin, a thermosetting resin, and a thermoplastic resin.
The material constituting the second structure is any one of an ultraviolet curable resin, a thermosetting resin, and a thermoplastic resin.
The display according to claim 8 or 9, wherein the material constituting the first high refractive index portion and the second high refractive index portion contains an inorganic compound. A method for manufacturing a display body including a display element composed of a material that transmits incident light, and the step of manufacturing the display element is a process.
On the surface of the layer made of the first low refractive index material, a plurality of convex portions arranged in a sub-wavelength period and concave portions alternately arranged with the convex portions along the arrangement direction of the plurality of convex portions, which are the same as the surface. A first step of forming a concave-convex structure layer having the convex portion and the concave portion by forming a plurality of concave portions having an area equal to the area of the plurality of convex portions when viewed from opposite directions.
Using a high refractive index material having a higher refractive index than the first low refractive index material, a high refractive index layer having a thickness smaller than the height of the convex portion is formed on the surface of the concave-convex structure layer. In two steps, as the high refractive index layer, a first sub-wavelength lattice located on the concave portion and a second sub located on the convex portion and having the same lattice period as the first sub-wavelength lattice. The second step of forming the layer including the wavelength lattice and
The structure is formed by forming an embedded layer made of a second low refractive index material having a refractive index lower than that of the high refractive index material on the surface of the structure composed of the uneven structure layer and the high refractive index layer. It viewed including a third step of filling the irregularities in the second low-refractive index material to said second sub-wavelength lattice having found a,
In the second step, a method for manufacturing a display body in which the high refractive index layer is formed so that the high refractive index layer includes a high refractive index portion extending along a side surface of the convex portion . In the first step, the intaglio is pressed against the coating layer made of the resin which is the first low refractive index material, the resin is cured, and then the intaglio is released to transfer the unevenness of the intaglio to the resin. By doing so, the uneven structure layer is formed.
In the second step, the high refractive index layer is formed by using a material containing an inorganic compound as the high refractive index material.
The eleventh aspect of claim 11 , wherein in the third step, the surface of the structure is coated with a resin which is the second low refractive index material, and the coated resin is cured to form the embedded layer. How to manufacture the display. In the third step, the two structures are opposed to each other so that the high refractive index layers face each other, and the region between the two structures is filled with the second low refractive index material. The method for manufacturing a display according to claim 11 or 12 , wherein the layer is formed.