JP2016071321A - Structural color display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structural color display capable of preventing an image (especially, its hue) displayed by using a structural color from being changed by the observation angle of an observer and to provide an image display object using the structural color display.SOLUTION: An image display device 10 which is an image display device on which the image is displayed by the structural color and includes at least an image display sheet 1 which has a structural color development area R1 which is an area where the structural color is developed and an incident/reflected light restriction part 2 which is installed on the image display side of the structural color development area R1 and selectively transmits incident light made incident on the surface S1 of the structural color development area R1 located on the image display side at a previously set angle and the reflected light reflected by a part of the structural color development area R1, of the incident light.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a structural color display and an image display using the same.

  In the technical field of image display devices, devices that display images using structural colors are already known. Examples of this type of image display device include those described in Patent Document 1 and Patent Document 2.

JP 2007-11112 A JP 2009-139800 A

  Many structural color displays that display an image with a structural color display a desired image using visible light having a wavelength determined by Bragg's law. For this reason, the structural color display according to the prior art has a problem that the displayed image (particularly its color) changes depending on the observation angle of the observer. This point will be briefly described with reference to FIG. Hereinafter, “structural color display” is also simply referred to as “image display device”.

  FIG. 12 is a schematic diagram for explaining a problem in the image display device according to the related art. FIGS. 12A and 12B are diagrams schematically illustrating a case where images displayed on the image display device 20 according to the related art are observed at different angles. As shown in FIG. 12A and FIG. 12B, the distance of light traveling in the image display sheet 1 (that is, the optical path length) varies depending on the observation angle of the observer. For this reason, the wavelength of the light which interferes changes and the color (namely, wavelength of reflected light) of the image displayed with the image display apparatus 20 changes. In FIG. 12, “3a” indicates incident light, and “3b” indicates reflected light (structural color).

  The present invention has been made in view of such circumstances, and a structural color capable of preventing an image (particularly the color) displayed using the structural color from changing depending on the viewing angle of the observer. An object is to provide a display and an image display using the display.

  In order to solve the above problems, an aspect of the present invention is an image display device that displays an image with a structural color, the image display sheet having a structural color expression region that is a region that expresses the structural color, Incident light that is placed on the image display side of the structural color expression region and is incident at a predetermined angle with respect to the surface of the structural color expression region located on the image display side, and the structure of the incident light The structural color display includes at least an incident / reflected light limiting unit that selectively transmits reflected light reflected by a part of the color expression region.

  According to the structural color display of one aspect of the present invention, it is possible to prevent an image displayed using the structural color from changing depending on the observation angle of the observer.

1 is a conceptual cross-sectional view illustrating a configuration of an image display device according to a first embodiment of the present invention. It is a schematic diagram for demonstrating the expression mechanism of the structural color in the image display apparatus which concerns on 1st Embodiment of this invention. It is a conceptual sectional view showing the composition of the image display device concerning a 2nd embodiment of the present invention. It is a schematic diagram for demonstrating the sheet | seat thickness change in the image display apparatus which concerns on 2nd Embodiment of this invention. It is a conceptual sectional view showing the composition of the image display device concerning a 3rd embodiment of the present invention. It is a conceptual sectional view showing the composition of the image display device concerning a 4th embodiment of the present invention. It is a conceptual sectional view showing the composition of the image display device concerning a 5th embodiment of the present invention. It is a conceptual sectional view showing the composition of the image display device concerning a 6th embodiment of the present invention. It is a conceptual sectional view showing the composition of the image display device concerning a 7th embodiment of the present invention. It is a conceptual sectional view showing the composition of the image display device concerning an 8th embodiment of the present invention. It is a conceptual sectional view showing the composition of the image display device concerning a 9th embodiment of the present invention. It is a schematic diagram for demonstrating the subject in the image display apparatus which concerns on a prior art.

Embodiments according to the present invention will be described below with reference to the drawings. In each drawing, parts having the same configuration and the same function are denoted by the same reference numerals.
[First Embodiment]
Hereinafter, the configuration of the image display apparatus 10 according to the first embodiment will be described. FIG. 1 is a conceptual cross-sectional view showing a configuration of an image display device 10 according to the first embodiment of the present invention. As shown in FIG. 1, an image display device 10 is an image display device that displays an image with a structural color, and includes an image display sheet 1 having a structural color expression region R1 that is a region that exhibits a structural color, and a structure. Incident light that is installed on the image display side of the color expression region R1 and is incident on the surface S1 on the image display side at a preset angle, and reflected light that is reflected by a part of the structural color expression region R1 of the incident light And the incident / reflected light limiting unit 2 that selectively transmits the light. Hereinafter, each of the members will be described.

(Image display sheet 1)
The image display sheet 1 is a sheet-like member that can express a structural color. The image display sheet 1 includes, for example, a thin film or plate integrally formed using a resin having a preset refractive index, or a gas having a preset refractive index between two sheets disposed opposite to each other. A laminate formed by filling one of a liquid and a solid can be used. Here, examples of the substance filled between the two sheets include a voltage-responsive polymer gel whose volume changes according to the applied voltage.
In addition, the image display sheet 1 should just be able to express a structural color, for example, the material and shape are not ask | required. Moreover, the size does not ask | require. As this image display sheet 1, for example, a structure in which a resin film having a lamellar structure, a chargeable organic polymer or inorganic spherical particles are migrated and regularly aligned in a vertical and horizontal direction on a predetermined support surface Using a metal structure having a nanostructure on the surface and a substrate having protrusions and recesses formed on the surface, the protrusions and recesses are imprinted on a plurality of resin plates by a nanoimprint technique, and the replication is performed. A substrate with a plurality of resin plates bonded together, an expansion / contraction body such as a stimulus-responsive polymer gel that changes in volume according to the electric field, a periodic structure disposed in the expansion / contraction body, and a structural color A sphere and a matrix having a display layer that expresses and a reflective interface that reflects light transmitted through the display layer, a laminate in which high-refractive index layers and low-refractive index layers are alternately stacked, and a wavelength of visible light 1 / An integral multiple of 2 wavelengths It can be exemplified microstructure or the like having a regular microstructure which is periodic interval.

The image display sheet 1 has a structural color expression region R1 that is a region that expresses a structural color (a region for displaying an image). The thickness of the image display sheet 1 in the structural color expression region R1 is substantially uniform over the entire structural color expression region R1.
The structural color expression region R1 may be any size, shape, or number.

(Incoming / reflecting light limiting unit 2)
On the surface S1 on the image display side of the structural color expression region R1, the incident / reflected light limiting unit 2 is disposed. The incident / reflected light limiting unit 2 includes an incident / reflected light transmission region R2 (R2a to R2f), and the incident / reflected light transmission region R2 includes incident light incident on the surface S1 at a preset angle, This refers to a region that selectively transmits reflected light reflected by a part of the structural color expression region R1 (for example, the surface S2) of the incident light. FIG. 1 shows an incident / reflected light transmission region that selectively transmits incident light incident at an angle within a range of 80 ° to 90 ° with respect to the surface S1 and reflected light reflected at an angle within the range. The incident / reflected light limiting unit 2 having R2 (R2a to R2f) is illustrated.

In the incident / reflected light limiting unit 2, for example, urexite arranged so as to transmit incident light incident along the thickness direction of the image display sheet 1 and optical fibers extending along the same direction are fixed in a bundle. It is possible to use one provided with at least one of the bundled optical fibers. In the case where the one provided with at least one of the urexite and the bundled optical fiber is used as the incident / reflected light limiting unit 2, for example, the light enters the surface S1 at an angle in the range of 80 ° to 90 °. It becomes easy to selectively transmit incident light and reflected light reflected at an angle within the range. Here, “Urexite” is an ore generally called a television stone, and is an aggregate in which transparent fibrous crystals are arranged completely in parallel.
The incident / reflected light limiting unit 2 only needs to be able to selectively transmit incident light and reflected light, and may be of any material or shape. Moreover, the size does not ask | require. Similarly, the size, shape and number of incident / reflected light transmission regions R2 (R2a to R2f) are not limited.

<Structure mechanism of structural color>
Hereinafter, the mechanism of expression of structural colors of the image display device 10 will be briefly described with reference to FIG.
FIG. 2 is a schematic diagram for explaining the mechanism of expression of structural colors in the image display device 10. FIG. 2 shows the image display sheet 1 having the structural color expression region R1 and the incident / reflected light limiting unit 2 arranged on the structural color expression region R1. In FIG. 2, the single light that selectively transmits the incident light 3 a incident at an angle in the range of 80 ° to 90 ° with respect to the surface S 1 and the reflected light 3 b reflected at the angle within the range. The incident / reflected light transmission region R2 (R2a) is illustrated. That is, FIG. 2 shows a part of the image display device 10 in an enlarged manner.

  First, light (for example, sunlight etc.) is irradiated toward the image display sheet 1 shown in FIG. At this time, the angle of light incident on the structural color expression region R1 is limited to an angle in the range of 80 ° to 90 ° with respect to the surface S1 by the incident / reflected light transmission region R2. Here, the “angle within the range of not less than 80 ° and not more than 90 °” is an angle set in advance in the first embodiment and can be arbitrarily changed. A part of the incident light 3a that reaches the structural color expression region R1 is reflected by the surface S1. Further, another part of the incident light 3a is reflected by the surface S2, for example. In this way, the reflected light 3b reflected by different surfaces (locations) interferes with each other, so that a structural color appears. The expressed structural color transmits through the incident / reflected light transmission region R2 and is observed (viewed) by the observer.

As described above, the angle of the light (incident light 3a) incident on the structural color expression region R1 and the angle of the light (reflected light 3b) reflected on the structural color expression region R1 are set as the incident / reflected light limiting unit 2. It can be limited (fixed) by. For this reason, even when the observation angle of the observer changes, the optical path length itself in the image display sheet 1 does not change, so the wavelength of the structural color to be expressed does not change. Therefore, according to the image display device 10 according to the first embodiment, it is possible to prevent the image displayed using the structural color from changing depending on the observation angle of the observer.

<How to use>
In the image display device 10, the regions where the incident / reflected light transmission region R2 and the structural color expression region R1 overlap each function as a pixel. For this reason, in the image display apparatus 10, it arrange | positions so that the image which preset each pixel may be displayed. The image display device 10 is installed outdoors, for example. Thereby, the sun can be used as the light source. By doing so, it is possible to display an image that does not require power for displaying an image and whose color or the like does not change depending on the observation angle of the observer.
In addition, what is necessary is just to change the thickness of the image display sheet 1 in the preset area | region, when displaying an image using a some structural color. By doing so, the optical path length in the image display sheet 1 changes, so that the color of the structural color can be changed. Thus, an image can be displayed using a plurality of structural colors.

[Second Embodiment]
Hereinafter, the configuration of the image display apparatus 11 according to the second embodiment will be described. FIG. 3 is a conceptual cross-sectional view showing the configuration of the image display device 11 according to the second embodiment of the present invention. As shown in FIG. 3, the structure of the image display device 11 is substantially the same as the structure of the image display device 10 according to the first embodiment described above, but the thickness d1 of the image display sheet 1 in the structural color expression region R1 is set as follows. It differs from the image display apparatus 10 in that the sheet thickness adjusting unit 4 to be adjusted is provided. Therefore, in the second embodiment, the sheet thickness adjusting unit 4 will be mainly described, and description of other components will be omitted.

(Sheet thickness adjusting unit 4)
The sheet thickness adjusting unit 4 is disposed at a position facing the incident / reflected light limiting unit 2 with the structural color expression region R1 interposed therebetween. As the sheet thickness adjusting unit 4, for example, one including an electrode (not shown) that contacts the image display sheet 1 can be used.
In addition, the sheet thickness adjustment part 4 should just be what can adjust the thickness d1 of the image display sheet 1 in the structural color expression area | region R1, for example, the means is not ask | required. Moreover, the size does not ask | require.

<Color change mechanism of structural color>
Hereinafter, means (mechanism) for changing the color of the structural color using the sheet thickness adjusting unit 4 including the electrode will be described with reference to FIG. FIG. 4 is a schematic diagram for explaining a change in sheet thickness in the image display apparatus 11 according to the second embodiment. 4A shows the state before changing the thickness of the image display sheet 1 (sheet thickness d1), and FIG. 4B shows the state after changing the sheet thickness (sheet thickness d2). ing. Moreover, the image display sheet 1 shown to Fig.4 (a) and FIG.4 (b) is a sheet | seat containing the voltage-responsive polymer gel from which a volume changes according to the applied voltage.

The electrode included in the sheet thickness adjusting unit 4 is in contact with the image display sheet 1, and when a voltage is applied to the electrode, the volume of the voltage-responsive polymer gel in the structural color expression region R1 responds to the applied voltage. Decrease or increase. Thus, the thickness of the image display sheet 1 in the structural color expression region R1 is adjusted by reducing or increasing the volume of the voltage-responsive polymer gel. FIG. 4B schematically shows how the volume of the voltage-responsive polymer gel increases in response to the applied voltage and the sheet thickness increases. Note that when the applied voltage is released, the volume of the voltage-responsive polymer gel returns to the state before voltage application, and thus the sheet thickness returns to the state shown in FIG.
When the thickness of the image display sheet 1 is changed as described above, the optical path length in the image display sheet 1 changes. Thus, the color of the structural color can be changed by changing the wavelength of the interfering light.

[Third Embodiment]
Hereinafter, the configuration of the image display device 12 according to the third embodiment will be described. FIG. 5 is a conceptual cross-sectional view showing the configuration of the image display device 12 according to the third embodiment of the present invention. As shown in FIG. 5, the structure of the image display device 12 is substantially the same as the structure of the image display device 10 according to the first embodiment described above, but the image display sheet 1 has a laminated structure. Different from the display device 10. Therefore, in the third embodiment, the image display sheet 1 having this laminated structure will be mainly described, and description of other components will be omitted.

(Image display sheet 1)
The image display sheet 1 provided in the image display device 12 is a multilayer structure in which structural color expression layers 1 a to 1 c that express a structural color are stacked along the thickness direction of the image display sheet 1. And the thickness of each layer of the structural color expression layers 1a-1c in the structural color expression area R1 is the same. Thus, incident light can be reflected in the interface in each layer of structural color expression layers 1a-1c by making image display sheet 1 into a multilayer structure. When light is reflected from a plurality of surfaces, the wavelength range in which interference can occur is narrowed, so that the monochromaticity of the structural color that is expressed can be enhanced.
The thickness of each of the structural color developing layers 1a to 1c may be an integral multiple of the thickness of the reference layer when any one of the structural color developing layers 1a to 1c is used as the reference layer. Even in this case, the monochromaticity of the developed structural color can be enhanced. In the third embodiment, the above-described reference layer is the structural color expression layer 1a, and the thickness of each of the structural color expression layers 1b and 1c is set to be one time the thickness of the structural color expression layer 1a.
Moreover, each layer of the structural color expression layers 1a-1c is formed with the same material altogether. By doing so, it is possible to reduce an increase in the manufacturing cost of the image display device 12.
In addition, the material and shape of each layer of structural color expression layers 1a-1c are not ask | required. Moreover, the size does not ask | require.

[Fourth Embodiment]
Hereinafter, the configuration of the image display device 13 according to the fourth embodiment will be described. FIG. 6 is a conceptual cross-sectional view showing the configuration of the image display device 13 according to the fourth embodiment of the present invention. As shown in FIG. 6, the structure of the image display device 13 is substantially the same as the structure of the image display device 11 according to the second embodiment described above, but between the image display sheet 1 and the incident / reflected light limiting unit 2. The image display device 11 is different from the image display device 11 in that a pixel partition frame (hereinafter, also simply referred to as “frame”) 5 for partitioning a pixel region is disposed. The image display device 11 is also different in that it includes a plurality of sheet thickness adjustment units 4 (4a to 4f). Therefore, in the fourth embodiment, the frame 5 and the sheet thickness adjusting units 4a to 4f will be mainly described, and the description of the other constituent members will be omitted. The number of structural color expression regions R1 (R1a to R1f) is not limited.

(Frame 5)
The frame 5 shown in FIG. 6 is a sheet-like member that is disposed between the image display sheet 1 and the incident / reflected light limiting unit 2 and absorbs visible light. The frame 5 includes an opening that exposes each of the structural color expression regions R1a to R1f to partition the pixel region.
Note that the frame 5 only needs to have an opening that divides the pixel region, and may be of any material or shape. Moreover, the size does not ask | require. For example, the frame 5 may be formed of an insulating film having electrical insulating properties, or may be formed of a material having elasticity (such as a buffer material). Further, the frame 5 is arranged as necessary, and is not an essential member in the present invention. Further, the shape, size, and number of the openings provided in the frame 5 are not limited. Further, the color of the frame 5 is, for example, black in order to clearly partition the pixel region.

(Sheet thickness adjusting portions 4a to 4f)
As shown in FIG. 4, the image display device 11 according to the second embodiment described above adjusts the sheet thickness of the structural color expression region R <b> 1 with one sheet thickness adjustment unit 4. In contrast, in the image display device 13 according to the fourth embodiment, the sheet thicknesses of the plurality of structural color expression regions R1a to R1f are adjusted by the plurality of sheet thickness adjustment units 4a to 4f. More specifically, the sheet thickness adjusting units 4a to 4f provided in the image display device 13 are arranged so as to overlap with the structural color expression regions R1a to R1f. In this way, the sheet thickness can be adjusted for each pixel. For example, as shown in FIG. 6, the red structural color R, the green structural color G, and the blue structural color B are displayed for each pixel. Can do. For this reason, an image with high resolution can be displayed. Further, with the above-described configuration, the red structural color R, the green structural color G, the blue structural color B, or the intermediate color can be freely displayed by one pixel.
The sheet thickness adjusting unit 4 provided in the image display device 11 and the sheet thickness adjusting units 4a to 4f provided in the image display device 13 have the same functions, although the installation positions and sizes are different.

[Fifth Embodiment]
Hereinafter, the configuration of the image display device 14 according to the fifth embodiment will be described. FIG. 7 is a conceptual cross-sectional view showing the configuration of the image display device 14 according to the fifth embodiment of the present invention. As shown in FIG. 7, the structure of the image display device 14 is the same as that of the image display device 13 according to the fourth embodiment described above except that the frame 5 is arranged so as to be embedded in the image display sheet 1. The same. Therefore, details of the structure of the image display device 14 are omitted here. In the image display device 14, a plano-convex lens 6 and microlens arrays 7 and 8 to be described later can be disposed on the incident / reflected light limiting unit 2.

[Sixth Embodiment]
The configuration of the image display device 15 according to the sixth embodiment will be described below. FIG. 8 is a conceptual cross-sectional view showing the configuration of the image display device 15 according to the sixth embodiment of the present invention. As shown in FIG. 8, the structure of the image display device 15 is substantially the same as the structure of the image display device 13 according to the fourth embodiment described above, but for widening the viewing angle on the incident / reflected light limiting unit 2. It differs from the image display device 13 in that it includes a plano-convex lens 6. Therefore, in the sixth embodiment, the plano-convex lens 6 will be mainly described, and description of other components will be omitted.

(Plano-convex lens 6)
The plano-convex lens 6 is a lens for widening the aperture angle of incident light and diffusing reflected light to widen the viewing angle. The plano-convex lens 6 is a lens having a plane and a convex surface located on the back side of the plane, and is arranged so as to cover the image display side of the incident / reflected light limiting unit 2. Further, in the state where the plano-convex lens 6 is disposed, the plane faces the incident / reflected light limiting unit 2 side. By doing so, the observer can observe the displayed image at a wider angle.
The plano-convex lens 6 may be any material and shape of the plano-convex lens 6 as long as the aperture angle of incident light is widened and the reflected light is diffused to widen the viewing angle. Moreover, the size does not ask | require.

[Seventh Embodiment]
The configuration of the image display device 16 according to the seventh embodiment will be described below. FIG. 9 is a conceptual cross-sectional view showing the configuration of the image display device 16 according to the seventh embodiment of the present invention. As shown in FIG. 9, the structure of the image display device 16 is substantially the same as the structure of the image display device 15 according to the sixth embodiment described above, but for widening the viewing angle on the incident / reflected light limiting unit 2. It differs from the image display device 15 in that the microlens array 7 is provided. Therefore, in the seventh embodiment, the microlens array 7 will be mainly described, and description of other components will be omitted.

(Microlens array 7)
Similar to the plano-convex lens 6 described above, the microlens array 7 is for widening the aperture angle of incident light and diffusing reflected light to widen the viewing angle. The microlens array 7 is composed of a plurality of microlenses 7a to 7h, and the microlenses 7a to 7h are planoconvex lenses having a plane and a convex surface located on the back side of the plane. Further, the microlens array 7 is disposed so as to cover the image display side of the incident / reflected light limiting unit 2, and in the state where the microlens array 7 is disposed, the planes of the microlenses 7 a to 7 h are limited to the incident / reflected light. It faces the part 2 side. By doing so, the observer can observe the image at a wider angle.
The microlens array 7 only needs to widen the opening angle of incident light and diffuse the reflected light to widen the viewing angle. For example, the material and shape of the microlenses 7a to 7h are not limited. Moreover, the size and number are not ask | required. That is, the size of the microlenses 7a to 7h does not need to match the size of the pixel region (that is, the size of the opening of the frame 5 and the structural color expression regions R1a to R1f).

[Eighth Embodiment]
Hereinafter, the configuration of the image display device 17 according to the eighth embodiment will be described. FIG. 10 is a conceptual cross-sectional view showing the configuration of the image display device 17 according to the eighth embodiment of the present invention. As shown in FIG. 10, the structure of the image display device 17 is substantially the same as the structure of the image display device 16 according to the seventh embodiment described above, but for widening the viewing angle on the incident / reflected light limiting unit 2. It differs from the image display device 16 in that the microlens array 8 is provided. Therefore, in the eighth embodiment, the microlens array 8 will be mainly described, and description of other components will be omitted.

(Microlens array 8)
Similar to the microlens array 7 described in the seventh embodiment, the microlens array 8 is for widening the viewing angle. The microlens array 8 includes a plurality of microlenses 8a to 8f, and the microlenses 8a to 8f are planoconvex lenses each having a flat surface and a convex surface located on the back side of the flat surface. In addition, the microlens array 8 is disposed so as to cover the image display side of the incident / reflected light limiting unit 2, and in the state where the microlens array 8 is disposed, the planes of the microlenses 8 a to 8 f are limited to incident / reflected light. It faces the part 2 side. Further, the diameters of the microlenses 8a to 8f coincide with the size of the pixel region (that is, the size of the opening of the frame 5 and the structural color expression regions R1a to R1f). More specifically, the incident / reflected light limiting unit 2 according to the eighth embodiment includes a bundled optical fiber in which optical fibers extending along the thickness direction of the image display sheet 1 are fixed in a bundle. Microlenses 8a to 8f are arranged on the opening end face of the optical fiber. Furthermore, the diameters of the microlenses 8a to 8f are the same as the diameters of the opening end faces of the optical fibers. By doing so, it is possible to prevent the resolution of the displayed image from being lowered, and the observer can observe the image at a wide angle.
Note that the microlens array 8 only needs to widen the opening angle of incident light and diffuse the reflected light to widen the viewing angle. For example, the material and shape of the microlenses 8a to 8f are not limited.

[Ninth Embodiment]
Hereinafter, the configuration of the image display device 18 according to the ninth embodiment will be described. FIG. 11 is a conceptual cross-sectional view showing the configuration of the image display device 18 according to the ninth embodiment of the present invention. As shown in FIG. 11, the structure of the image display device 18 is substantially the same as the structure of the image display device 15 according to the sixth embodiment described above, but the opening angle of the incident light is set on the incident / reflected light limiting unit 2. It differs from the image display device 15 in that it includes a light scattering sheet 9 that spreads and diffuses reflected light. Therefore, in the ninth embodiment, the light scattering sheet 9 will be mainly described, and description of other components will be omitted.

(Light scattering sheet 9)
The light scattering sheet 9 is a sheet-like member for widening the opening angle of incident light and diffusing reflected light to widen the viewing angle. The light scattering sheet 9 is arranged so as to cover the image display side of the incident / reflected light limiting unit 2. By doing so, the observer can observe the image at a wider angle.
Note that the light scattering sheet 9 may be any material or shape as long as it can widen the opening angle of incident light and diffuse the reflected light to widen the viewing angle. Moreover, the size does not ask | require.

(effect)
(1) The image display devices 10 to 18 are set in advance for the image display sheet 1 having the structural color expression region R1 and the surface S1 that is installed on the image display side of the structural color expression region R1 and is positioned on the image display side. At least the incident light 3a incident at an angle and the incident light 3a that selectively reflects the reflected light 3b reflected from a part of the structural color expression region R1 of the incident light 3a.
With such a configuration, the incident angle of the incident light 3a and the reflection angle of the reflected light 3b can be set to preset angles. For this reason, even when the observation angle of the observer is different, the optical path length in the image display sheet 1 does not change, and the wavelength of the interfering light does not change. Thereby, it can prevent that the structural color displayed with the image display apparatuses 10-18 changes.
Moreover, if it is such a structure, if the light source of the incident light 3a will be sunlight, the electric power for displaying an image will not be required.

(2) The incident / reflected light restricting unit 2 of the image display devices 10 to 18 reflects the incident light 3a incident on the surface S1 at an angle in the range of 80 ° to 90 ° and the angle within the angular range. The reflected light 3b is selectively transmitted.
With such a configuration, the image can be observed from a direction substantially perpendicular to the surface S1, and thus the visibility of the displayed image can be further improved. Also, since the viewing angle can be narrowed, peeping can be prevented (privacy view guard).

(3) The incident / reflected light limiting unit 2 of the image display devices 10 to 18 includes a urexite disposed so as to be able to transmit incident light 3 a incident along the thickness direction of the image display sheet 1, and the thickness direction of the image display sheet 1. At least one of a bundled optical fiber in which optical fibers extending along the bundle are fixed in a bundle is provided.
Urexite and bundled optical fibers can be obtained relatively easily. Therefore, with such a configuration, the manufacturing cost of the incident / reflected light limiting unit 2 can be reduced. Therefore, the manufacturing cost of the entire image display device can be reduced.

(4) The image display device 11 includes a sheet thickness adjustment unit 4 that adjusts the thickness of the image display sheet 1 in the structural color expression region R1 at a position facing the incident reflection light limiting unit 2 with the structural color expression region R1 interposed therebetween. ing.
With such a configuration, since the thickness of the image display sheet 1 in the structural color expression region R1 can be freely adjusted, the color of the structural color to be expressed can be variously changed.

(5) The sheet thickness adjusting unit 4 of the image display device 11 includes an electrode that contacts the image display sheet 1, and the image display sheet 1 is formed of a voltage-responsive polymer gel whose volume changes according to voltage. Yes. The sheet thickness adjusting unit 4 includes a heating unit capable of heating the image display sheet 1, and the image display sheet 1 is formed of a thermoresponsive polymer gel whose volume changes according to heat. The sheet thickness adjusting unit 4 includes a light irradiation unit that can irradiate the image display sheet 1 with light, and the image display sheet 1 is formed of a photoresponsive polymer gel whose volume changes according to light.
With such a configuration, the thickness d1 of the image display sheet 1 can be freely adjusted by applying a voltage to the electrodes included in the sheet thickness adjusting unit 4. Therefore, it is possible to change the color of the structural color that is expressed in various ways, and it is possible to further increase the speed (response speed) of changing the color of the structural color. In addition, there exists an effect similar to this also by the heating with respect to the image display sheet 1, or light irradiation.

(6) The image display sheet 1 of the image display device 12 is a multilayer structure in which structural color expression layers 1a to 1c that express a structural color are stacked along the thickness direction of the image display sheet 1, and a structural color expression region R1 The thickness of each of the structural color developing layers 1a to 1c is an integer multiple of the thickness of the reference layer when any one of the laminated structural color developing layers 1a to 1c is used as the reference layer.
With such a configuration, a structural color with improved monochromaticity can be expressed.

(7) The structural color developing layers 1a to 1c of the image display device 12 are all formed of the same material.
With such a configuration, a structural color with improved monochromaticity can be produced at low cost.

(8) The image display device 15 further includes a plano-convex lens 6 which is disposed so as to cover the image display side of the incident / reflected light limiting unit 2 and has a plane and a convex surface located on the back side of the plane. The 6 plane faces the incident / reflected light limiting unit 2 side.
With such a configuration, since the incident light 3a and the reflected light 3b can be easily scattered, the viewing angle can be easily widened.

(9) The image display device 16 includes a microlens array 7 including a plurality of microlenses 7a to 7h.
With such a configuration, the incident light 3a and the reflected light 3b can be reliably scattered, so that the viewing angle can be more reliably widened.

(10) The incident / reflected light limiting unit 2 of the image display device 17 includes a bundled optical fiber in which optical fibers extending in the thickness direction of the image display sheet 1 are fixed in a bundle, and each opening of the optical fiber. Microlenses 8a to 8f are arranged on the end face, and the diameters of the microlenses 8a to 8f are the same as the diameter of the opening end face of the optical fiber.
With such a configuration, since the incident light 3a and the reflected light 3b can be easily scattered, the viewing angle can be further widened.

(11) The image display device 18 further includes a light scattering sheet 9 that scatters the incident light 3a and the reflected light 3b, which is disposed so as to cover the image display side of the incident / reflected light limiting unit 2.
With such a configuration, since the incident light 3a and the reflected light 3b can be easily scattered, the viewing angle can be easily widened.

(Modification)
(1) In the above embodiment, the incident / reflected light limiting unit 2 having the plurality of incident / reflected light transmission regions R2a to R2f has been described. However, the present invention is not limited to this. For example, the incident / reflected light limiting unit 2 may have a single incident / reflected light transmission region R2. Even in this case, the above-described effects can be achieved.

(2) In the above-described embodiment, the incident / reflected light limiting unit 2 in which the incident / reflected light transmission regions R2 (R2a to R2f) are located apart from each other has been described, but the present invention is not limited to this. For example, the incident / reflected light transmission regions R2 (R2a to R2f) may be adjacent to each other. Even in this case, the above-described effects can be achieved.

(3) In the above-described embodiment, the sheet thickness adjusting unit 4 (4a to 4f) including the electrode that contacts the image display sheet 1 has been described. However, the present invention is not limited to this. The sheet thickness adjusting unit 4 (4a to 4f) only needs to change the sheet thickness of the structural color expression region R1 (R1a to R1f). For example, the sheet thickness adjustment unit 4 (4a to 4f) includes a pump and the like, and the structural color expression region R1 (R1a to R1f) is added in the sheet thickness direction using the sheet thickness adjustment unit 4 (4a to 4f). You may change the sheet | seat thickness of structural color expression area | region R1 (R1a-R1f) by carrying out pressure and pressure reduction. Even in this case, the above-described effects can be achieved.
The sheet thickness adjusting unit 4 (4a to 4f) may be, for example, a light irradiation device that can irradiate light or a heating device that can apply heat. Even in this case, the above-described effects can be achieved. Here, when the sheet thickness adjusting unit 4 (4a to 4f) is a light irradiation device, the image display sheet 1 is preferably formed of, for example, a photoresponsive polymer gel. When the sheet thickness adjusting unit 4 (4a to 4f) is a heating device, the image display sheet 1 is preferably formed of, for example, a temperature-responsive polymer gel.

(4) In the above-described embodiment, the image display sheet 1 including three layers of the structural color expression layers 1a to 1c has been described. However, the present invention is not limited to this. For example, the image display sheet may be a multilayer structure, and may be a structure in which two structural color developing layers are stacked, or a structure in which four or more structural color developing layers are stacked. . Even in this case, the above-described effects can be achieved.

(5) In the above embodiment, the case where the reference layer is the structural color developing layer 1a has been described, but the present invention is not limited to this. For example, the reference layer may be the structural color expression layer 1b or the structural color expression layer 1c. Even in this case, the above-described effects can be achieved.

(6) In the above embodiment, the case where the structural color developing layers 1a to 1c are all formed of the same material has been described, but the present invention is not limited to this. For example, each of the structural color developing layers 1a to 1c may be formed of different materials. Even in this case, the above-described effects can be achieved.

(7) In the above embodiment, the case where the plano-convex lens 6 and the microlens arrays 7 and 8 are used to widen the viewing angle of the displayed image has been described, but the present invention is not limited to these. . A lens other than a plano-convex lens or a microlens array may be used as long as the viewing angle of the displayed image can be widened. Even in these cases, the above-described effects can be achieved.

(8) In the above embodiment, the case where the frame 5 is provided between the image display sheet 1 and the incident / reflected light limiting unit 2 or embedded in the image display sheet 1 has been described. It is not limited. Even if the frame 5 is not provided, the above-described effects can be achieved. Further, by not providing the frame 5, the structural color expression regions R1a to R1f can be made wider.

(9) In the above-described embodiment, the image display apparatus that displays an image using structural colors has been described. However, the present invention is not limited to these. For example, the image display device described in the above embodiment may be incorporated in an image display medium and used as an image display object. More specifically, a poster or calendar can be created by incorporating the image display device described in the above embodiment into paper.

  Although the present invention has been described with reference to a limited number of embodiments and modifications, the scope of rights is not limited thereto, and modifications of each embodiment based on the above disclosure are obvious to those skilled in the art. That is.

DESCRIPTION OF SYMBOLS 1 Image display sheet 1a-1c Structural color expression layer 2 Incident reflected light restriction | limiting part 3a Incident light 3b Reflected light (structural color)
4 Sheet Thickness Adjustment Units 4a to 4f Sheet Thickness Adjustment Unit 5 Pixel Partition Frame (Frame)
6 Plano-convex lens 7 Micro lens array 7a-7h Micro lens 8 Micro lens array 8a-8f Micro lens 9 Light scattering sheet 10-18 Image display device 20 Image display device R Red structural color G Green structural color B Blue structural color R1 Structural color expression region R1a to R1f Structural color expression region R2 Incident / reflected light transmission region R2a to R2f Incident / reflected light transmission region S1 surface (image display side surface)
S2 side (back side)
d1 to d2 Sheet thickness

Claims (13)

A structural color display in which an image is displayed by a structural color,
An image display sheet having a structural color expression region that is a region expressing the structural color;
Incident light that is installed on the image display side of the structural color expression region and is incident at a predetermined angle with respect to the surface of the structural color expression region located on the image display side, A structural color display comprising at least an incident / reflected light limiting unit that selectively transmits reflected light reflected by a part of the structural color expression region.   The incident / reflected light limiting unit includes the incident light incident at an angle within a range of 80 ° to 90 ° with respect to the surface of the structural color expression region, and the reflected light reflected at an angle within the range. The structural color display according to claim 1, wherein the structural color display is selectively transmissive.   The incident / reflected light limiting unit fixes a urexite disposed so as to transmit incident light incident along a thickness direction of the image display sheet and an optical fiber extending along the thickness direction of the image display sheet in a bundle shape. The structural color display according to claim 1, comprising at least one of a bundle of optical fibers. A structural color display in which an image is displayed by a structural color,
An image display sheet having a structural color expression region that is a region expressing the structural color;
Urexite installed on the image display side of the structural color expression region and arranged to transmit incident light incident along the thickness direction of the image display sheet, and light extending along the thickness direction of the image display sheet A structural color display comprising: an incident / reflected light limiting unit including at least one of a bundle of optical fibers in which fibers are fixed in a bundle.   The sheet thickness adjusting unit further adjusts the thickness of the image display sheet in the structural color developing region at a position facing the incident / reflected light restricting unit across the structural color developing region. The structural color display according to claim 4. The sheet thickness adjusting unit includes any one of an electrode that contacts the image display sheet, a heating unit that can heat the image display sheet, and a light irradiation unit that can irradiate the image display sheet with light.
The image display sheet is a voltage-responsive polymer gel whose volume changes according to a voltage or an electric field applied to the electrodes, a heat-responsive polymer gel whose volume changes according to heat from the heating unit, 6. The structural color display according to claim 5, wherein the structural color display is formed of any one of photoresponsive polymer gels whose volume changes in response to light from the light irradiation unit. The image display sheet is a multilayer structure in which a structural color expression layer that expresses the structural color is laminated along the thickness direction of the image display sheet,
The thickness of each of the structural color expression layers in the structural color expression region is an integral multiple of the thickness of the reference layer when any one of the stacked structural color expression layers is used as a reference layer. The structural color display according to any one of claims 1 to 6, wherein the structural color display is characterized.   8. The structural color display according to claim 7, wherein each layer of the structural color developing layer is formed of the same material. A plano-convex lens having a flat surface and a convex surface located on the back surface side of the flat surface, disposed so as to cover the image display side of the incident / reflected light limiting unit;
9. The structural color display according to claim 1, wherein the plane of the plano-convex lens faces the incident / reflected light restricting portion side.   The structural color display according to claim 9, wherein the plano-convex lens is a microlens array including a plurality of microlenses. The incident / reflected light limiting unit includes a bundled optical fiber in which optical fibers extending along the thickness direction of the image display sheet are fixed in a bundle.
The microlens is arranged on each opening end face of the optical fiber,
The structural color display according to claim 10, wherein the diameter of the microlens is the same as the diameter of the opening end face of the optical fiber.   The light scattering sheet for diffusing the incident light and the reflected light, which is disposed so as to cover the display side of the image of the incident / reflected light limiting unit, further comprises: The structural color display according to any one of the preceding claims.   An image display object comprising the structural color display according to any one of claims 1 to 12.