JP2020160096A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device having a desired optical function such as dimming action or excellent light distribution performance. SOLUTION: A first substrate 10, a second substrate 20 arranged to face the first substrate 10, a first electrode 30 arranged on the second substrate 20 side of the first substrate 10, and a first electrode The concave-convex structure 50 arranged on the second substrate 20 side of 30 and the second electrode 41 arranged on the first substrate 10 side of the second substrate 20 are arranged between the concave-convex structure 50 and the second electrode 41. The variable refractive electrode layer 70 includes a variable refractive index layer 70 in which at least one of the absorbance and the refractive electrode changes according to the voltage applied between the first electrode 30 and the second electrode 41, and the variable refractive electrode layer 70 is an insulating liquid. It has 71 and the first fine particles 72a and the second fine particles 72b contained in the insulating liquid 71, the first fine particles 72a are charged with the first polarity, and the second fine particles 72b have a light-shielding property. Moreover, it is charged with the second polarity, and the refractive electrode of the first fine particles 72a is higher than the refractive electrode of the insulating liquid 71. [Selection diagram] FIG. 7

Description

The present invention relates to an optical device.

Conventionally, as an optical device, a light distribution device capable of distributing incident light has been proposed. Such optical devices are used for windows of buildings, cars, and the like. For example, by installing an optical device in a window of a building, it is possible to change the traveling direction of external light such as sunlight incident from the outside and introduce the outside light toward the ceiling of the room (for example, Patent Document). 1, 2).

As a light distribution device of this type, a device using a liquid crystal is known. For example, Patent Document 3 discloses a liquid crystal optical element including a pair of transparent substrates, a pair of transparent electrodes arranged inside the pair of transparent substrates, and a liquid crystal layer arranged between the pair of transparent electrodes. Has been done. In a light distribution device using a liquid crystal, the traveling direction of light incident on the light distribution device is changed by changing the orientation state of the liquid crystal molecules in the liquid crystal layer according to the voltage applied to the pair of transparent electrodes.

Japanese Unexamined Patent Publication No. 2012-259951 International Publication No. 2015/056736 Japanese Unexamined Patent Publication No. 2012-173534

However, a light distribution device using a liquid crystal cannot obtain sufficient light distribution performance. There is also a demand for an optical device capable of performing dimming control without using a liquid crystal.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an optical device having a desired optical function such as dimming action or excellent light distribution performance.

In order to achieve the above object, one aspect of the first optical device according to the present invention is a light-transmitting first substrate and a light-transmitting second substrate arranged to face the first substrate. The substrate, the first electrode arranged on the second substrate side of the first substrate, the uneven structure arranged on the second substrate side of the first electrode, and the first substrate side of the second substrate. Dimming, which is arranged between the concave-convex structure and the second electrode, and whose absorbance changes according to the voltage applied between the first electrode and the second electrode. The dimming layer includes a layer, and the dimming layer has an insulating liquid and charged light-shielding particles dispersed in the insulating liquid.

Further, one aspect of the second optical device according to the present invention is an optical device that controls incident light, that is, a first substrate having light transmission and light arranged to face the first substrate. A second substrate having transparency, a first electrode arranged on the second substrate side of the first substrate, an uneven structure arranged on the second substrate side of the first electrode, and the second substrate. A light-shielding particle having a second electrode arranged on the first substrate side of the above, and a charged light-shielding particle arranged between the uneven structure and the second electrode and dispersed in the insulating liquid and the insulating liquid. The optical device includes a dispersion layer, and controls dimming of light incident on the optical device according to a voltage applied between the first electrode and the second electrode.

Further, one aspect of the third optical device according to the present invention includes a first substrate having light transmission, a second substrate having light transmission arranged opposite to the first substrate, and the first substrate. A first electrode arranged on the second substrate side of the substrate, a concave-convex structure arranged on the second substrate side of the first electrode, and a second arranged on the first substrate side of the second substrate. The first electrode and the second electrode are provided with an electrode and a light-shielding particle dispersion layer having an insulating liquid and charged light-shielding particles dispersed in the insulating liquid, which is arranged between the concave-convex structure and the second electrode. The particle distribution of the light-shielding particles in the light-shielding particle dispersion layer changes according to the voltage applied between the light-shielding particles and the second electrode.

Further, one aspect of the fourth optical device according to the present invention includes a first substrate having light transmission, a second substrate having light transmission arranged opposite to the first substrate, and the first substrate. The first electrode arranged on the second substrate side of the substrate, the uneven structure arranged on the second substrate side of the first electrode, and the second arranged on the first substrate side of the second substrate. A refractive electrode that is arranged between the electrode, the uneven structure, and the second electrode, and at least one of the absorbance and the refractive electrode changes according to the voltage applied between the first electrode and the second electrode. A variable layer is provided, and the variable refractive electrode layer has an insulating liquid and first and second fine particles contained in the insulating liquid, and the first fine particles are charged with the first polarity. The second fine particles have a light-shielding property and are charged with a second polarity opposite to the first polarity, and the refractive electrode of the first fine particles is the refractive electrode of the insulating liquid. Higher than.

Further, one aspect of the fifth optical device according to the present invention is an optical device that controls incident light, that is, a first substrate having light transmission and light arranged to face the first substrate. A second substrate having transparency, a first electrode arranged on the second substrate side of the first substrate, an uneven structure arranged on the second substrate side of the first electrode, and the second substrate. A second electrode arranged on the first substrate side of the above, an insulating liquid arranged between the uneven structure and the second electrode, and first and second fine particles dispersed in the insulating liquid. The first fine particles are charged with the first polarity, and the second fine particles have a light-shielding property and have a second polarity opposite to the first polarity. The optical device is charged with, and controls at least one of the traveling direction and dimming of the light incident on the optical device according to the voltage applied between the first electrode and the second electrode. To do.

In addition, one aspect of the sixth optical device according to the present invention includes a first substrate having light transmission, a second substrate having light transmission arranged opposite to the first substrate, and the first substrate. The first electrode arranged on the second substrate side of the substrate, the uneven structure arranged on the second substrate side of the first electrode, and the second arranged on the first substrate side of the second substrate. The first particle is provided with an electrode, an insulating liquid, and a fine particle dispersion layer having first fine particles and second fine particles dispersed in the insulating liquid, which are arranged between the concave-convex structure and the second electrode. The fine particles are charged with the first polarity, and the second fine particles have a light-shielding property and are charged with a second polarity opposite to the first polarity, and the first electrode and the above. The particle distribution of the first fine particles and the second fine particles in the fine particle dispersion layer changes according to the voltage applied between the second electrode and the second electrode.

According to the present invention, it is possible to realize an optical device having a desired optical function such as a dimming function or excellent light distribution performance.

It is sectional drawing of the optical device which concerns on Embodiment 1. FIG. It is an enlarged sectional view of the optical device which concerns on Embodiment 1. FIG. It is a figure for demonstrating the first optical action of the optical device which concerns on Embodiment 1. FIG. It is a figure for demonstrating the second optical action of the optical device which concerns on Embodiment 1. FIG. It is a figure for demonstrating the optical action of the optical device which concerns on the modification of Embodiment 1. FIG. It is sectional drawing of the optical device which concerns on Embodiment 2. FIG. It is an enlarged sectional view of the optical device which concerns on Embodiment 2. FIG. It is a top view which shows the structure of the 2nd electrode and the 3rd electrode in the optical device which concerns on Embodiment 2. FIG. It is a figure for demonstrating the first optical action of the optical device which concerns on Embodiment 2. FIG. It is a figure for demonstrating the second optical action of the optical device which concerns on Embodiment 2. FIG. It is a figure for demonstrating the third optical action of the optical device which concerns on Embodiment 2. FIG. It is an enlarged cross-sectional view of the optical device which concerns on modification 1. FIG. It is a top view which shows the structure of the 2nd electrode and the 3rd electrode in the optical device which concerns on modification 2. FIG.

Hereinafter, embodiments of the present invention will be described. In addition, all of the embodiments described below show a preferable specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement positions of the components, connection forms, and the like shown in the following embodiments are examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept of the present invention will be described as arbitrary components.

Each figure is a schematic view and is not necessarily exactly illustrated. Therefore, the scales and the like do not always match in each figure. In each figure, substantially the same configuration is designated by the same reference numerals, and duplicate description will be omitted or simplified.

Further, in the present specification and the drawings, the X-axis, the Y-axis, and the Z-axis represent the three axes of the three-dimensional Cartesian coordinate system. In the present embodiment, the Z-axis direction is the vertical direction and is perpendicular to the Z-axis. (Direction parallel to the XY plane) is the horizontal direction. The X-axis and the Y-axis are orthogonal to each other and both are orthogonal to the Z-axis. The positive direction in the Z-axis direction is vertically downward. Further, in the present specification, the "thickness direction" means the thickness direction of the optical device, and is a direction perpendicular to the main surfaces of the first substrate 10 and the second substrate 20 (in the present embodiment, the Y-axis direction). That is.

(Embodiment 1)
First, the configuration of the optical device 1 according to the embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view of the optical device 1 according to the first embodiment. FIG. 2 is an enlarged cross-sectional view of the optical device 1, and shows an enlarged view of a region II surrounded by a broken line in FIG.

The optical device 1 is an optical control device that controls light incident on the optical device 1. Specifically, the optical device 1 is a dimming device that controls dimming of light incident on the optical device 1.

As shown in FIGS. 1 and 2, the optical device 1 includes a first substrate 10, a second substrate 20, a first electrode 30, a second electrode 40, an uneven structure 50, and a dimming layer 60. Be prepared.

In the optical device 1, the first electrode 30, the concave-convex structure 50, the dimming layer 60, and the second electrode 40 are arranged between the pair of the first substrate 10 and the second substrate 20 in this order along the thickness direction. It is composed.

Further, as shown in FIG. 1, in the optical device 1, the first substrate 10, the first electrode 30, and the concave-convex structure 50 constitute the first laminated substrate 100, and the second substrate 20 and the second electrode 40 are the first. The two laminated substrates 200 are configured.

The first laminated substrate 100 and the second laminated substrate 200 are arranged so as to face each other with a gap, and the entire circumference of the outer peripheral end portion is sealed. As a result, the dimming layer 60 filled between the first laminated substrate 100 and the second laminated substrate 200 can be confined. For example, a sealing member such as an adhesive is formed on the inner surface of the first laminated substrate 100 and the second laminated substrate 200 in a frame shape, or the first substrate 10 and the second substrate 20 are welded by a laser. By doing so, the outer peripheral ends of the first laminated substrate 100 and the second laminated substrate 200 can be sealed.

Hereinafter, each component of the optical device 1 will be described in detail with reference to FIGS. 1 and 2.

[First board, second board]
As shown in FIGS. 1 and 2, the first substrate 10 is the base material of the first laminated substrate 100, and the second substrate 20 is the base material of the second laminated substrate 200.

The first substrate 10 and the second substrate 20 are light-transmitting substrates (translucent substrate). The first substrate 10 and the second substrate 20 are preferably transparent transparent substrates.

As the first substrate 10 and the second substrate 20, for example, a resin substrate made of a resin material or a glass substrate made of a glass material can be used. Examples of the material of the resin substrate include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), acrylic and epoxy. Examples of the material of the glass substrate include soda glass, non-alkali glass, high refractive index glass and the like. The resin substrate has an advantage that it is less scattered at the time of destruction. On the other hand, the glass substrate has the advantages of high light transmittance and low moisture transmittance.

The first substrate 10 and the second substrate 20 may be made of the same material or may be made of different materials, but it is better that they are made of the same material. Further, the first substrate 10 and the second substrate 20 are not limited to the rigid substrate, and may be a flexible substrate or a film substrate. In the present embodiment, a transparent resin substrate (PET substrate) made of PET is used as the first substrate 10 and the second substrate 20.

The thickness of the first substrate 10 and the second substrate 20 is, for example, 5 μm to 3 mm, but is not limited to this. In the present embodiment, the thickness of the first substrate 10 and the second substrate 20 are both 50 μm.

Further, the shape of the first substrate 10 and the second substrate 20 in a plan view is, for example, a square or a rectangular rectangle, but the shape is not limited to this, and may be a polygon other than a circle or a quadrangle. Shape can be adopted.

[First electrode, second electrode]
As shown in FIGS. 1 and 2, the first electrode 30 and the second electrode 40 are electrically paired and are configured to be able to apply an electric field to the dimming layer 60. Further, the first electrode 30 and the second electrode 40 are arranged in pairs and are arranged so as to face each other.

The first electrode 30 is arranged on the second substrate 20 side of the first substrate 10. Further, the second electrode 40 is arranged on the first substrate 10 side of the second substrate 20. Specifically, the first electrode 30 is formed on the main surface of the first substrate 10 on the second substrate 20 side, and the second electrode 40 is formed on the main surface of the second substrate 20 on the first substrate 10 side. It is formed.

Further, in the present embodiment, the pair of the first electrode 30 and the second electrode 40 are arranged between the first substrate 10 and the second substrate 20 so as to sandwich at least the concave-convex structure 50 and the dimming layer 60. Has been done. Specifically, the first electrode 30 is arranged between the first substrate 10 and the concave-convex structure 50, and the second electrode 40 is arranged between the second substrate 20 and the dimming layer 60. There is.

The thickness of each of the first electrode 30 and the second electrode 40 is, for example, 5 nm to 2 μm, but is not limited thereto. In the present embodiment, the thickness of each of the first electrode 30 and the second electrode 40 is 100 nm.

Further, the shape of the first electrode 30 and the second electrode 40 in a plan view is, for example, a square or a rectangular rectangle like the first substrate 10 and the second substrate 20, but is not limited thereto. In the present embodiment, the first electrode 30 and the second electrode 40 are solid electrodes having a rectangular shape in a plan view formed on substantially the entire surface of each of the surfaces of the first substrate 10 and the second substrate 20.

The first electrode 30 and the second electrode 40 are electrodes having translucency and transmit incident light. The first electrode 30 and the second electrode 40 are transparent electrodes made of, for example, a transparent conductive layer. As the material of the transparent conductive layer, a conductor-containing resin composed of a transparent metal oxide such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), and a resin containing a conductor such as silver nanowires or conductive particles. Alternatively, a metal thin film such as a silver thin film can be used. The first electrode 30 and the second electrode 40 may have a single-layer structure thereof or a laminated structure thereof (for example, a laminated structure of a transparent metal oxide and a metal thin film).

The first electrode 30 and the second electrode 40 are configured to enable electrical connection with an external power source. For example, each of the first electrode 30 and the second electrode 40 is pulled out to the outside of the sealing resin that seals the dimming layer 60, and the pulled out portion can be used as an electrode terminal for connecting to an external power source. Good.

[Concave and convex structure]
As shown in FIGS. 1 and 2, the concavo-convex structure 50 is a concavo-convex layer having a concavo-convex surface, and has a configuration in which a plurality of micro-order-sized or nano-order-sized convex portions 51 are arranged.

The uneven structure 50 is arranged on the second substrate 20 side of the first substrate 10. In the present embodiment, the concave-convex structure 50 is arranged on the second substrate 20 side of the first electrode 30. Specifically, the concave-convex structure 50 is provided on the main surface of the first electrode 30 on the second substrate 20 side.

In the present embodiment, the concave-convex structure 50 is provided on the first electrode 30 so that the plurality of convex portions 51 project toward the dimming layer 60. In this case, an adhesion layer may be formed between the first electrode 30 and the uneven structure 50. The surface of the concave-convex structure 50 on the first electrode 30 side (the surface of the convex portion 51 on the first electrode 30 side) is a flat surface.

Further, the plurality of convex portions 51 are formed in a striped shape. Specifically, each of the plurality of convex portions 51 has a triangular cross-sectional shape and is a long substantially triangular prism shape extending in the X-axis direction, and is arranged at equal intervals along the Z-axis direction. Further, all the convex portions 51 have the same shape, but the present invention is not limited to this.

Each convex portion 51 has, for example, a height of 100 nm or more and 100 μm or less, and an aspect ratio (height / lower base) of about 1 to 10, but is not limited to this. As an example, each convex portion 51 has a height of about 10 μm, a lower base of about 5 μm, and an upper base of about 2 μm.

Further, the distance between the two convex portions 51 adjacent to each other in the Z-axis direction is, for example, 0 or more and 100 mm or less. That is, the two convex portions 51 adjacent to each other in the Z-axis direction may be arranged with a predetermined interval without contacting the bottoms, or may be arranged with the bottoms in contact with each other (at zero interval). However, the distance between the two convex portions 51 adjacent to each other in the Z-axis direction is preferably equal to or less than the length of the base of the convex portions 51. As an example, in the case of the convex portion 51 of the above size (height 10 μm, base 5 μm), the distance between two adjacent convex portions 51 is about 2 μm.

Each of the plurality of protrusions 51 has a pair of side surfaces. In the present embodiment, the cross-sectional shape of each convex portion 51 is a tapered shape that tapers along the direction (Y-axis minus direction) from the second substrate 20 to the first substrate 10. Therefore, each of the pair of side surfaces of each convex portion 51 is an inclined surface that is inclined at a predetermined inclination angle with respect to the thickness direction, and the distance between the pair of side surfaces in each convex portion 51 (width of the convex portion 51). Is gradually getting smaller from the second substrate 20 toward the first substrate 10. The inclination angles of the two sides of each convex portion 51 may be the same or different. In the present embodiment, the cross-sectional shape of each convex portion 51 is an isosceles triangle, and the inclination angles (base angles) of the two side surfaces of each convex portion 51 are the same.

The pair of side surfaces of each convex portion 51 is a surface in contact with the dimming layer 60, and the light incident from the first substrate 10 receives an optical action on the pair of side surfaces of the convex portion 51.

Specifically, on one side surface (lower side surface in the present embodiment) of the pair of side surfaces of the convex portion 51, the light incident from the first substrate 10 is the convex portion 51 and the dimming layer 60. Depending on the difference in the refractive index of, it may be refracted and transmitted, or it may be transmitted as it is without being refracted.

Further, on the other side surface (upper side surface in the present embodiment) of the pair of side surfaces of the convex portion 51, the light incident from the first substrate 10 has a refractive index difference between the convex portion 51 and the dimming layer 60. Depending on the situation, it may be refracted and transmitted, it may be transmitted as it is without refraction, or it may be totally reflected. That is, the upper side surface of the convex portion 51 can be a total reflection surface depending on the difference in refractive index between the convex portion 51 and the dimming layer 60 and the incident angle of light.

As the material of the concave-convex structure 50 (convex portion 51), for example, a translucent resin material such as an acrylic resin, an epoxy resin, or a silicone resin can be used. The uneven structure 50 can be formed by, for example, laser processing or imprinting. In the present embodiment, the uneven structure 50 is formed by using an acrylic resin having a refractive index of about 1.5.

The concave-convex structure 50 may be made of only an insulating resin material as long as an electric field can be applied to the light control layer 60 by the first electrode 30 and the second electrode 40, but the concave-convex structure 50 may be made of only an insulating resin material. You may have. In this case, as the material of the uneven structure 50, a conductive polymer such as PEDOT, a resin containing a conductor (conductor-containing resin), or the like can be used.

[Dimming layer]
As shown in FIGS. 1 and 2, the dimming layer 60 has an insulating liquid 61 and light-shielding particles 62 contained in the insulating liquid 61. The dimming layer 60 is a light-shielding particle dispersion layer in which innumerable light-shielding particles 62 are dispersed in an insulating liquid 61.

The insulating liquid 61 is a transparent liquid having an insulating property, and is a solvent that serves as a dispersion medium in which the light-shielding particles 62 are dispersed as a dispersoid. As the insulating liquid 61, for example, a liquid having a refractive index (solvent refractive index) of about 1.3 to about 1.6 can be used. In this embodiment, an insulating liquid 61 having a refractive index of about 1.5 is used.

The kinematic viscosity of the insulating liquid 61 is preferably about 100 mm ² / s. Further, the insulating liquid 61 is preferably having a low dielectric constant (dielectric constant of the concave-convex structure 50 or less), non-flammable (high flash point having a flash point of 250 ° C. or higher), and low volatility. Specifically, the insulating liquid 61 is a hydrocarbon (aliphatic hydrocarbon, naphtha, other petroleum-based solvent, etc.), a low molecular weight halogen-containing polymer, or a mixture thereof. As an example, the insulating liquid 61 is a halogenated carbon hydrogen such as fluorocarbon hydrogen. As the insulating fluid 61, silicone oil or the like can also be used.

The light-shielding particles 62 are light-absorbing particles, and a plurality of the light-shielding particles 62 are dispersed in the insulating liquid 61. The light-shielding particles 62 are fine particles (nanoparticles) having a particle size of microorder size (microparticles) or nanoorder size. As the light-shielding particles 62, for example, carbon particles made of carbon black can be used.

Further, the light-shielding particles 62 are charged particles that are charged. For example, by modifying the surface of the light-shielding particles 62, the light-shielding particles 62 can be positively (plus) or negatively (minus) charged. In the present embodiment, the light-shielding particles 62 are negatively charged. In the dimming layer 60, the charged light-shielding particles 62 are dispersed throughout the insulating liquid 61.

The dimming layer 60 is arranged between the concave-convex structure 50 and the second electrode 40. Specifically, the dimming layer 60 is in contact with the uneven structure 50. That is, the contact surface of the light control layer 60 with the uneven surface of the uneven structure 50 is the interface between the light control layer 60 and the uneven surface of the uneven structure 50. The dimming layer 60 is also in contact with the second electrode 40.

Further, the dimming layer 60 is an absorbance variable layer whose absorbance changes according to the voltage applied between the first electrode 30 and the second electrode 40. Specifically, the dimming layer 60 is arranged between the first electrode 30 and the second electrode 40, and is adjusted by applying a voltage between the first electrode 30 and the second electrode 40. An electric field is applied to the light layer 60. For example, a DC voltage is applied between the first electrode 30 and the second electrode 40.

Since the light-shielding particles 62 dispersed in the insulating liquid 61 are charged, when an electric field is applied to the dimming layer 60, the light-shielding particles 62 travel in the insulating liquid 61 according to the electric field distribution, and the insulating liquid It is unevenly distributed within 61. As a result, the particle distribution of the light-shielding particles 62 in the light control layer 60 can be changed to have the concentration distribution of the light-shielding particles 62 in the light control layer 60, so that the absorbance distribution in the light control layer 60 changes. .. That is, the absorbance of the light control layer 60 is partially changed. In this way, the dimming layer 60 functions as a light absorption layer capable of absorbing incident light, and can dimm the incident light according to the changing absorbance. That is, the dimming layer 60 can control the amount of light transmitted through the dimming layer 60 (transmission amount).

The absorbance of the light control layer 60 can be changed by adjusting the concentration (amount) of the light-shielding particles 62 dispersed in the insulating liquid 61. In this case, the concentration of the light-shielding particles 62 is such that when the light-shielding particles 62 are aggregated in the concave-convex structure 50, the light-shielding particles 62 are present around the bottom of the concave portion of the concave-convex structure 50 (for example, a height of 2 μm from the bottom of the concave portion). The concentration may be set to.

The dimming layer 60 configured in this way is arranged between the first laminated substrate 100 and the second laminated substrate 200. Specifically, the insulating liquid 61 in which the light-shielding particles 62 are dispersed is sealed between the first laminated substrate 100 and the second laminated substrate 200.

The thickness of the dimming layer 60 (that is, the gap between the first laminated substrate 100 and the second laminated substrate 200) is, for example, 1 μm to 100 μm, but is not limited to this. As an example, when the height of the convex portion 51 of the concave-convex structure 50 is 10 μm, the thickness of the dimming layer 60 is, for example, 40 μm.

[Manufacturing method of optical device]
Next, a method of manufacturing the optical device 1 will be described with reference to FIGS. 1 and 2.

First, using, for example, a PET substrate as the first substrate 10, an ITO film is formed as the first electrode 30 on the PET substrate, and a plurality of acrylic resins (refractive index 1.5) are formed on the ITO film. The first laminated substrate 100 is manufactured by forming the concavo-convex structure 50 composed of the convex portions 51 by the imprint method.

Next, the second laminated substrate 200 is manufactured by forming the second electrode 40 made of an ITO film on the PET substrate using, for example, a PET substrate as the second substrate 20.

Next, between the first laminated substrate 100 and the second laminated substrate 200, an insulating liquid 61 in which light-shielding particles 62 are dispersed is filled as a dimming layer 60, and the first laminated substrate 100 and the second laminated substrate 100 and the second laminated substrate 200 are filled. The dimming layer 60 is sealed between the first laminated substrate 100 and the second laminated substrate 200 by joining the outer peripheral portion with the substrate 200.

In this way, the optical device 1 having the structure shown in FIG. 1 can be manufactured.

[Optical action of optical device]
Next, the optical action of the optical device 1 according to the embodiment will be described with reference to FIGS. 3A and 3B. FIG. 3A is a diagram for explaining the first optical action of the optical device 1 according to the embodiment, and FIG. 3B is a diagram for explaining the second optical action of the optical device 1.

The optical device 1 can be realized as a window with a dimming control function by installing it on a window of a building, for example. The optical device 1 is attached to a window of a building via, for example, an adhesive layer. In this case, the optical device 1 is installed in the window so that the longitudinal direction of the convex portion 51 of the concave-convex structure 50 is the horizontal direction. For example, sunlight is incident on the optical device 1 installed in the window. In the present embodiment, since the optical device 1 is installed so that the first substrate 10 is located on the light incident side (outside of the building), the optical device 1 is the light (sunlight) incident from the first substrate 10. ) Can be transmitted from the second substrate 20 to the inside of the building (for example, indoors) of the optical device 1.

At this time, the light incident on the optical device 1 receives an optical action from the optical device 1 when passing through the optical device 1. Specifically, the optical action of the optical device 1 changes depending on the change in the absorbance of the light control layer 60. Therefore, the light incident on the optical device 1 undergoes different optical actions depending on the absorbance of the light control layer 60, and the amount of light transmitted changes according to the absorbance of the light control layer 60.

In the present embodiment, the optical device 1 can perform dimming control of the light incident on the optical device 1 according to the voltage applied between the first electrode 30 and the second electrode 40. Specifically, the particle distribution of the light-shielding particles 62 in the dimming layer 60 (light-shielding particle dispersion layer) changes according to the voltage applied between the first electrode 30 and the second electrode 40, whereby The absorbance of the dimming layer 60 changes partially. As a result, the optical action of the optical device 1 changes. The optical device 1 in this embodiment has two optical actions. Hereinafter, the two optical actions of the optical device 1 will be described in detail.

First, the first optical action of the optical device 1 will be described with reference to FIG. 3A. When no potential is applied to the first electrode 30 and the second electrode 40, that is, when no voltage is applied between the first electrode 30 and the second electrode 40 (when no voltage is applied), optics. The device 1 enters the first optical mode and gives the first optical action to the incident light.

In the first optical mode, no electric field is applied to the dimming layer 60, so that the light-shielding particles 62 are dispersed throughout the insulating liquid 61 in the dimming layer 60, as shown in FIG. 3A.

In this case, as shown in FIG. 3A, when the light L1 is incident on the optical device 1 from an oblique direction, the light L1 is absorbed by the dimming layer 60. Specifically, since the light-shielding particles 62 are dispersed throughout the dimming layer 60, the light L1 incident on the optical device 1 is the convex portion 51 and the concave portion of the concave-convex structure 50 (two adjacent convex portions 51). When passing through any of the intervening portions), the light-shielding particles 62 block the light.

As described above, when no voltage is applied between the first electrode 30 and the second electrode 40, the optical device 1 blocks the light incident on the first substrate 10. That is, the first optical mode is a light-shielding mode, and in the first optical mode, the optical device 1 is in a light-shielding state.

Further, when the optical device 1 is in the light shielding mode, the light L1 incident on the optical device 1 is not always completely absorbed by the optical device 1, and is dimmed and transmitted according to the absorbance of the dimming layer 60. May be done. In this case, since the optical device 1 in the present embodiment is provided with the concave-convex structure 50, the light incident on the optical device 1 depends on the magnitude relationship between the refractive index of the concave-convex structure 50 and the refractive index of the dimming layer 60. L1 receives an optical action at the interface between the concave-convex structure 50 and the light control layer 60 and transmits the optical device 1.

For example, in the present embodiment, the refractive index of the concave-convex structure 50 is about 1.5. Therefore, when the refractive index of the dimming layer 60 is about 1.5, as shown in FIG. 3A, the light L1 is Since it is not refracted at the interface between the concave-convex structure 50 and the light control layer 60, it transmits the optical device 1 in a straight line. When the refractive index of the light control layer 60 is different from the refractive index of the concave-convex structure 50, the light L1 is refracted at the interface between the concave-convex structure 50 and the light control layer 60. At this time, when the refractive index of the light control layer 60 is larger than the refractive index of the concave-convex structure 50 (for example, about 1.6), the light L1 is adjusted to the lower side surface of the light control layer 60 and the convex portion 51. After refraction at the interface with the light layer 60, total internal reflection occurs at the interface between the light control layer 60 and the upper side surface of the convex portion 51 and the light control layer 60, and the traveling direction is bent in the direction of rebound of the optical device 1. It emits to the outside. That is, the light L1 incident on the optical device 1 is absorbed while being distributed by the optical device 1.

Next, the second optical action of the optical device 1 will be described with reference to FIG. 3B. When a potential is applied to the first electrode 30 and the second electrode 40, that is, when a voltage is applied between the first electrode 30 and the second electrode 40 (when a voltage is applied), the optical device 1 , The second optical mode is set, and the second optical action is given to the incident light. Specifically, a DC voltage is applied as a voltage between the first electrode 30 and the second electrode 40. The first voltage (potential difference) applied between the first electrode 30 and the second electrode 40 is, for example, about several tens of volts.

In the second optical mode, an electric field is applied to the dimming layer 60 by applying a DC voltage between the first electrode 30 and the second electrode 40. Therefore, in the dimming layer 60, the charged light-shielding particles 62 are generated. It runs in the insulating liquid 61 according to the electric field distribution. That is, the light-shielding particles 62 electrophores in the insulating liquid 61.

Specifically, in the second optical mode, a positive potential is applied to the first electrode 30 and a negative potential is applied to the second electrode 40, so that the negatively charged light-shielding particles 62 are the first electrode having a positive potential. It migrates toward the 30 side and is aggregated and unevenly distributed on the uneven structure 50 side in the dimming layer 60. At this time, the light-shielding particles 62 that migrate toward the first electrode 30 enter the concave portion of the concave-convex structure 50, that is, the region between the two adjacent convex portions 51 and accumulate.

As described above, the light-shielding particles 62 are unevenly distributed on the uneven structure 50 side in the light control layer 60, so that the particle distribution of the light-shielding particles 62 changes and the absorbance distribution in the light control layer 60 becomes uneven. Specifically, in the light control layer 60, the light-shielding particles 62 are gathered by the electrophoresis of the light-shielding particles 62, and the concentration of the light-shielding particles 62 is increased. By electrophoresis, the light-shielding particles 62 disappear, and the second region 60b on the second electrode 40 side where the concentration of the light-shielding particles 62 becomes low is generated.

Further, since the light-shielding particles 62 aggregated on the concave-convex structure 50 side of the dimming layer 60 have entered and accumulated in the concave portion of the concave-convex structure 50, the concave-convex structure 50 is formed in the region of the light control layer 60 on the concave-convex structure 50 side. A region having a relatively large absorbance and a region having a relatively low absorbance in the Z-axis direction are alternately generated according to the unevenness of. Specifically, the region where the absorbance is relatively large is the region where the concave portion of the concave-convex structure 50 in which the light-shielding particles 62 are aggregated exists, and the region where the absorbance is relatively low is the region where the convex portion 51 of the concave-convex structure 50 is present. Area to do.

In this case, as shown in FIG. 3B, when the light L1 is incident on the optical device 1 from an oblique direction, the light L1 is absorbed by the dimming layer 60 as in the first optical mode, but the third In the bi-optical mode, since the light-shielding particles 62 are accumulated in the recess on the concave-convex structure 50 side, they receive an optical action different from that in the first optical mode. Specifically, of the light incident on the first substrate 10, the light that passes through the convex portion 51 of the concave-convex structure 50 does not pass through the region where the light-shielding particles 62 are aggregated (the region where the absorbance is small), so that the light-shielding particles 62 The light is transmitted through the dimming layer 60 without being shielded from light. On the other hand, of the light incident on the first substrate 10, the light passing through the concave portion of the concave-convex structure 50 passes through the region where the light-shielding particles 62 are aggregated (the region having high absorbance), and is therefore shielded by the light-shielding particles 62.

In this way, when a voltage is applied between the first electrode 30 and the second electrode 40, the optical device 1 blocks the light incident on the first substrate 10 that passes through the concave-convex structure 50. Make it transparent without doing it. In this case, the absorbance of the dimming layer 60 when a voltage is applied between the first electrode 30 and the second electrode 40 (second optical mode) is between the first electrode 30 and the second electrode 40. It is smaller than the absorbance of the dimming layer 60 when no voltage is applied to the light (first optical mode), and the light transmission amount in the second optical mode is larger than that in the first optical mode. That is, the second optical mode is the translucent mode, and in the second optical mode, the optical device 1 is in the translucent state.

Since the optical device 1 is provided with the concave-convex structure 50, similarly to the above, the light L1 incident on the optical device 1 depends on the magnitude relationship between the refractive index of the concave-convex structure 50 and the refractive index of the dimming layer 60. , Receives optical action at the interface between the concave-convex structure 50 and the dimming layer 60. For example, the light L1 incident on the optical device 1 passes straight through the optical device 1 or is bent in the traveling direction in the direction of rebounding due to the concave-convex structure 50.

Further, when the potential applied to the first electrode 30 and the second electrode 40 is set to zero so that no voltage is applied, the light-shielding particles 62 run through the insulating liquid 61, and as shown in FIG. 3A, the light-shielding particles 62 Returns to a state in which is uniformly dispersed throughout the insulating liquid 61.

The optical device 1 configured as described above is an active type optical control device capable of changing the optical action by controlling the refractive index matching between the concave-convex structure 50 and the dimming layer 60 by an electric field. That is, the optical device 1 can be switched to a plurality of optical modes by controlling the voltage applied between the first electrode 30 and the second electrode 40. In the present embodiment, the optical device 1 can be switched between two modes, a first optical mode (light-shielding mode) and a second optical mode (translucency mode).

[Summary]
As described above, according to the optical device 1 according to the present embodiment, the concave-convex structure 50 and the dimming layer 60 are arranged between the first electrode 30 and the second electrode 40, and the dimming layer 60 is charged. An insulating liquid 61 (light-shielding particle dispersion layer) in which the light-shielding particles 62 are dispersed is used.

With this configuration, the light-shielding particles 62 run through the insulating liquid 61 by applying a voltage between the first electrode 30 and the second electrode 40, so that the absorbance of the dimming layer 60 can be changed. Specifically, the particle distribution of the light-shielding particles 62 in the dimming layer 60 changes, and the absorbance distribution of the dimming layer 60 changes. That is, the light transmittance of the dimming layer 60 changes. Thereby, the dimming control of the light incident on the optical device 1 can be performed.

In the present embodiment, when no voltage is applied between the first electrode 30 and the second electrode 40 (when no voltage is applied), the optical device 1 is in the light shielding mode and the first substrate 10 is set. When a voltage is applied between the first electrode 30 and the second electrode 40 (when a voltage is applied), the optical device 1 is set to the translucent mode, and the first Of the light incident on the substrate 10, the light passing through the concave-convex structure 50 is transmitted without shading.

At this time, when the voltage is applied, the light-shielding particles 62 are unevenly distributed on the uneven structure 50 side in the light control layer 60 (light-shielding particle dispersion layer), so that the uneven structure 50 is located in the region of the light control layer 60 on the uneven structure 50 side. Therefore, a region having a relatively large absorbance and a region having a relatively low absorbance are alternately generated. As a result, the light control layer 60 can have an absorbance distribution.

According to the optical device 1 according to the present embodiment configured as described above, dimming control can be performed without using a liquid crystal. Thereby, an optical device having a desired optical function can be realized.

In the present embodiment, the optical device 1 can be switched to only two modes, a first optical mode (light-shielding mode) and a second optical mode (translucency mode), but the present invention is not limited to this. For example, as in the optical device 1A shown in FIG. 4, by arranging the third electrode 42 on the first substrate 10 side of the second substrate 20, the third optical mode can be further switched. ..

In the optical device 1A shown in FIG. 4, the second electrode 41 is formed in a striped shape so as to extend in the X-axis direction. Similarly, the third electrode 42 is formed in a stripe shape so as to extend in the X-axis direction. Further, the second electrode 41 and the third electrode 42 are formed on the same surface of the second substrate 20, and are arranged alternately along the Z-axis direction. That is, the second electrode 41 and the third electrode 42 in this modification have a shape as if the second electrode 40 in the first embodiment is divided into a plurality of parts. In this modification, the total area of the third electrode 42 is smaller than the total area of the second electrode 41 in a plan view. As a result, when the light-shielding particles 62 are aggregated by the third electrode 42, the light-shielding region by the light-shielding particles 62 on the second substrate 20 side can be reduced and the light-transmitting region can be widened.

Then, in the optical device 1A, when the potential applied to the first electrode 30 is V1, the potential applied to the second electrode 41 is V2, and the potential applied to the third electrode 42 is V3, V1 <V2 <V3. Set the potential of each electrode so as to satisfy the relationship. For example, a negative potential may be applied to the first electrode 30, a ground potential may be applied to the second electrode 41, and a positive potential may be applied to the third electrode 42. As an example, V1 = −20V, V2 = 0V, V3 = + 20V. By setting V1 <V2 <V3 in this way, as shown in FIG. 4, the negatively charged light-shielding particles 62 migrate toward the positive potential third electrode 42 and are aggregated on the third electrode 42. Is unevenly distributed.

In this case, as shown in FIG. 4, when the light L1 is incident on the optical device 1A from an oblique direction, a part of the light incident on the first substrate 10 is the same as in the second optical mode. Is shielded from light, and some other light is transmitted without being shielded. Specifically, of the light incident on the first substrate 10, the light passing through the second electrode 41 does not pass through the region where the light-shielding particles 62 are aggregated, so that the light-shielding particles 62 do not block the light and the dimming layer 60. Is transparent. On the other hand, of the light incident on the first substrate 10, the light passing through the third electrode 42 passes through the region where the light-shielding particles 62 are aggregated, and is therefore blocked by the light-shielding particles 62.

As described above, the optical device 1A in the present modification transmits the light incident on the first substrate 10 that passes through the second electrode 41 without shading, and the light incident on the first substrate 10 is transmitted. Of these, the light passing through the third electrode 42 is blocked.

At this time, since the total area of the third electrode 42 is smaller than the total area of the second electrode 41 in this modification, the absorbance of the dimming layer 60 when V1 <V2 <V3 (in the case of this modification) Is smaller than the absorbance of the dimming layer 60 when V1> V2 and V3 (for example, in the case of the first embodiment). That is, the third optical mode in this modification is a transparent mode in which the absorbance of the dimming layer 60 is smaller (higher transmittance) than in the second optical mode, and in the third optical mode, the optical device 1 is in a transparent state. It has become.

(Embodiment 2)
Next, the configuration of the optical device 2 according to the second embodiment will be described with reference to FIGS. 5 and 6. FIG. 5 is a cross-sectional view of the optical device 2 according to the second embodiment. Further, FIG. 6 is an enlarged cross-sectional view of the optical device 2, and shows an enlarged view of the region VI surrounded by the broken line in FIG.

Similar to the first embodiment, the optical device 2 is an optical control device that controls the light incident on the optical device 2, and controls at least one of the traveling direction and dimming of the light incident on the optical device 2.

In the present embodiment, the optical device 2 controls both the traveling direction and the dimming control with respect to the light incident on the optical device 2. Specifically, the optical device 2 is a light distribution device capable of changing the traveling direction of light incident on the optical device 2 (for example, distributing light) and emitting light, and light incident on the optical device 2. It is a dimming device that controls dimming.

As shown in FIGS. 5 and 6, the optical device 2 includes a first substrate 10, a second substrate 20, a first electrode 30, a second electrode 41, a third electrode 42, and an uneven structure 50. A variable refractive index layer 70 is provided. That is, the optical device 2 in the present embodiment has a configuration in which the dimming layer 60 is replaced with the variable refractive index layer 70 in the optical device 1A in the modified example of the first embodiment.

As shown in FIGS. 5 and 6, in the present embodiment, the first laminated substrate 100 is composed of the first substrate 10, the first electrode 30, and the concave-convex structure 50, as in the first embodiment. There is. On the other hand, in the present embodiment, the second laminated substrate 200 is composed of the second substrate 20, the second electrode 41, and the third electrode 42.

The first laminated substrate 100 and the second laminated substrate 200 are arranged so as to face each other with a gap, as in the first embodiment, and the entire circumference of the outer peripheral end portion is sealed. As a result, the variable refractive index layer 70 filled between the first laminated substrate 100 and the second laminated substrate 200 can be confined.

Hereinafter, each component of the optical device 2 will be described with reference to FIGS. 5 and 6, focusing on components different from those of the first embodiment.

[First electrode, second electrode, third electrode]
As shown in FIGS. 5 and 6, the first electrode 30 is arranged on the second substrate 20 side of the first substrate 10, and the second electrode 41 and the third electrode 42 are the first substrate 10 of the second substrate 20. It is located on the side. Specifically, the first electrode 30 is formed on the main surface of the first substrate 10 on the second substrate 20 side, and the second electrode 41 and the third electrode 42 are the first substrate 10 of the second substrate 20. It is formed on the same main surface on the side.

The shape of the first electrode 30 in a plan view is a solid electrode having a rectangular shape in a plan view formed on substantially the entire surface of the surface of the first substrate 10, as in the first embodiment. On the other hand, as shown in FIG. 7, each of the second electrode 41 and the third electrode 42 is formed in a striped shape so as to extend in the X-axis direction with a constant width. That is, the second electrode 41 and the third electrode 42 are the same as the stripe direction of the concave-convex structure 50. Further, the second electrode 41 and the third electrode 42 are alternately arranged along the Z-axis direction.

As described above, the second electrode 41 and the third electrode 42 in the present modification have a shape as if the second electrode 40 in the first embodiment is divided into a plurality of parts. In FIG. 7, in order to make the second electrode 41 and the third electrode 42 easier to understand, hatching is performed at the positions where the second electrode 41 and the third electrode 42 are formed for convenience.

As shown in FIG. 7, the width of the third electrode 42 is smaller than the width of the second electrode 41, and the total area of the third electrode 42 is larger than the total area of the second electrode 41 in a plan view. It's getting smaller. As a result, when the second fine particles 72b are aggregated by the third electrode 42, the light-shielding region of the second fine particles 72b on the second substrate 20 side can be reduced and the light-transmitting region can be widened.

In the present embodiment, both ends of the plurality of third electrodes 42 are connected to each other, but both ends of the plurality of third electrodes 42 may not be connected to each other. When both ends of the plurality of third electrodes 42 are not connected, both ends of the plurality of second electrodes 41 may be connected to each other.

The first electrode 30, the second electrode 41, and the third electrode 42 are arranged between the first substrate 10 and the second substrate 20 so as to sandwich at least the concave-convex structure 50 and the variable refractive index layer 70. Specifically, the first electrode 30 is arranged between the first substrate 10 and the concave-convex structure 50, and the second electrode 41 and the third electrode 42 are the second substrate 20 and the variable refractive index layer 70. It is placed between.

The thickness of each of the first electrode 30, the second electrode 41, and the third electrode 42 is, for example, 5 nm to 2 μm, but is not limited thereto. In the present embodiment, the thickness of each of the first electrode 30, the second electrode 41, and the third electrode 42 is 100 nm. The second electrode 41 and the third electrode 42 may be formed at the same time by patterning.

The first electrode 30, the second electrode 41, and the third electrode 42 are electrodes having translucency and transmit incident light. The first electrode 30, the second electrode 41, and the third electrode 42 are transparent electrodes made of, for example, a transparent conductive layer such as a transparent metal oxide (ITO, IZO, etc.), as in the first embodiment.

The first electrode 30, the second electrode 41, and the third electrode 42 are configured to enable electrical connection with an external power source. For example, each electrode may be drawn out to the outside of the sealing resin that seals the variable refractive index layer 70, and the drawn out portion may be used as an electrode terminal for connecting to an external power source.

[Variable refractive index layer]
As shown in FIGS. 5 and 6, the refractive index variable layer 70 has an insulating liquid 71 and first fine particles 72a and second fine particles 72b contained in the insulating liquid 71. The variable refractive index layer 70 is a fine particle dispersion layer in which the first fine particles 72a and the second fine particles 72a are innumerably dispersed in the insulating liquid 71.

The insulating liquid 71 is a transparent liquid having an insulating property, and is a solvent that serves as a dispersion medium in which the first fine particles 72a and the second fine particles 72b are dispersed as dispersants. As the insulating liquid 71, for example, a liquid having a refractive index (solvent refractive index) of about 1.3 to about 1.6 can be used. In this embodiment, an insulating liquid 71 having a refractive index of about 1.5 is used.

Also in this embodiment, the kinematic viscosity of the insulating liquid 71 is preferably about 100 mm ² / s, and the insulating liquid 71 has a low dielectric constant (less than or equal to the dielectric constant of the uneven structure 50) and is not. It is preferable to have flammability (high flash point of 250 ° C. or higher) and low volatility. Specifically, as the insulating liquid 71, a hydrocarbon such as carbon halide, a low molecular weight halogen-containing polymer, a mixture thereof, or the like may be used as in the first embodiment, or silicone. Oil or the like may be used.

A plurality of the first fine particles 72a and the second fine particles 72b are dispersed in the insulating liquid 71. The first fine particles 72a are translucent particles having translucency. On the other hand, the second fine particles 72b are light-shielding particles having a light-shielding property.

The first fine particles 72a are preferably made of a material having a high transmittance. Specifically, the first fine particles 72a may be transparent particles. Further, the first fine particles 72a are preferably made of a high refractive index material. Specifically, the refractive index of the first fine particles 72a is higher than the refractive index of the insulating liquid 71. In the present embodiment, the refractive index of the first fine particles 72a is higher than the refractive index of the uneven structure 50. As such first fine particles 72a, metal oxide fine particles can be used. In the present embodiment, transparent zirconia particles having a refractive index of 2.1 and composed of zirconium oxide (ZrO ₂ ) are used as the first fine particles 72a. The first fine particles 72a are not limited to zirconium oxide, and may be made of titanium oxide or the like.

The second fine particles 72b are preferably made of a material having a low transmittance. Specifically, the second fine particles 72b may be light-shielding particles. In the present embodiment, the second fine particles 72b are used, and carbon particles made of carbon black are used.

The first fine particles 72a are fine particles (nanoparticles) having a particle size of nanoorder size. Specifically, assuming that the wavelength of the incident light is λ, the particle size of the first fine particles 72a is preferably λ / 4 or less. By setting the particle size of the first fine particles 72a to λ / 4 or less, it is possible to reduce light scattering in the first fine particles 72a and obtain an average refractive index between the first fine particles 72a and the insulating liquid 71. it can. The smaller the particle size of the first fine particles 72a, the better, preferably 100 nm or less, and more preferably several nm to several tens of nm.

On the other hand, the second fine particles 72b are fine particles (nanoparticles) having a particle size of microorder size (microparticles) or nanoorder size (nanoparticles). The particle size of the second fine particles 72b should be larger than the particle size of the first fine particles 72a. By making the particle size of the second fine particles 72b larger than the particle size of the first fine particles 72a, the probability that the light scattered by the first fine particles 72a hits the second fine particles 72b increases, so that the light scattered by the first fine particles 72a Can be absorbed by the second fine particles 72b. Specifically, the particle size of the second fine particles 72b is preferably 100 nm or more.

The first fine particles 72a and the second fine particles 72b are charged particles that are charged. For example, by modifying the surfaces of the first fine particles 72a and the second fine particles 72b, the first fine particles 72a and the second fine particles 72b can be positively (plus) or negatively (minus) charged.

In the present embodiment, the first fine particles 72a are charged with the first polarity, and the second fine particles 72b are charged with the second polarity opposite to the first polarity. Specifically, the first fine particles 72a are positively charged, and the second fine particles 72b are negatively charged.

In the variable refractive index layer 70 configured in this way, the charged first fine particles 72a and second fine particles 72b are dispersed in the entire insulating liquid 71, respectively. In the present embodiment, zirconia particles having a refractive index of 2.1 are used as the first fine particles 72a, and carbon particles are used as the second fine particles 72b, and the first fine particles 72a and the second fine particles 72b have a refractive index of about 2. The variable refractive index layer 70 is dispersed in the insulating liquid 71 of 1.5.

The refractive index (average refractive index) of the entire variable refractive index layer 70 is uneven when the first fine particles 72a and the second fine particles 72b are uniformly dispersed in the variable refractive index layer 70 (insulating liquid 71). It is different from the refractive index of the structure 50. Specifically, the refractive index of the entire variable refractive index layer 70 is set to be higher than the refractive index of the concave-convex structure 50, which is about 1.6 in the present embodiment.

The refractive index of the entire variable refractive index layer 70 can be changed by adjusting the concentration (amount) of the first fine particles 72a dispersed in the insulating liquid 71. Although the details will be described later, the amount of the first fine particles 72a may be such that the first fine particles 72a are buried in the recesses of the concave-convex structure 50 (the region between the two adjacent convex portions 51). In this case, the first fine particles 72a with respect to the insulating liquid 71 The concentration of is about 10% to 30%.

The variable refractive index layer 70 is arranged between the concave-convex structure 50 and the second electrode 41 and the third electrode 42. Specifically, the variable refractive index layer 70 is in contact with the uneven structure 50. That is, the contact surface of the variable refractive index layer 70 with the uneven surface of the concave-convex structure 50 is the interface between the variable refractive index layer 70 and the uneven surface of the concave-convex structure 50. The variable refractive index layer 70 is also in contact with the second electrode 41 and the third electrode 42, but another layer (film) is formed between the variable refractive index layer 70 and the second electrode 41 and the third electrode 42. May intervene.

Further, the refractive index of the variable refractive index layer 70 changes according to the voltage applied between the first electrode 30 and the second electrode 41. Further, in the present embodiment, since the third electrode 42 is formed, the refractive index variable layer 70 has a voltage applied between the first electrode 30 and the third electrode 42 and the second electrode 41 and the third electrode 42. The refractive index changes according to the voltage applied between the three electrodes 42.

Specifically, the variable refractive index layer 70 is arranged between the first electrode 30, the second electrode 41, and the third electrode 42, and is placed on the first electrode 30, the second electrode 41, and the third electrode 42. An electric field is applied to the variable refractive index layer 70 by applying a voltage. For example, a DC voltage is applied to the first electrode 30, the second electrode 41, and the third electrode 42.

Since the first fine particles 72a dispersed in the insulating liquid 71 are charged, when an electric field is applied to the variable refractive index layer 70, the first fine particles 72a migrate in the insulating liquid 71 according to the electric field distribution. , Is unevenly distributed in the insulating liquid 71. As a result, the particle distribution of the first fine particles 72a in the variable refractive index layer 70 can be changed to have the concentration distribution of the first fine particles 72a in the variable refractive index layer 70. The refractive index distribution changes. That is, the refractive index of the variable refractive index layer 70 changes partially. As described above, the variable refractive index layer 70 functions mainly as a refractive index adjusting layer capable of adjusting the refractive index with respect to light in the visible light region.

Further, since the second fine particles 72a dispersed in the insulating liquid 71 are charged, when an electric field is applied to the refractive index variable layer 70, the second fine particles 72b move in the insulating liquid 71 according to the electric field distribution. It migrates and is unevenly distributed in the insulating liquid 71. As a result, the particle distribution of the second fine particles 72b in the variable refractive index layer 70 can be changed to have the concentration distribution of the second fine particles 72b in the variable refractive index layer 70. The absorbance distribution changes. That is, the absorbance of the variable refractive index layer 70 is partially changed.

In this way, the variable refractive index layer 70 functions as a light absorption layer capable of absorbing incident light, and can adjust the incident light according to the changing absorbance. That is, the variable refractive index layer 70 can control the amount of light (transmitted amount) transmitted through the variable refractive index layer 70.

The absorbance of the variable refractive index layer 70 can be changed by adjusting the concentration (amount) of the second fine particles 72b dispersed in the insulating liquid 71. In this case, the concentration of the second fine particles 72b is such that when the second fine particles 72b are aggregated in the concave-convex structure 50, the second fine particles 72b are present around the bottom of the concave portion of the concave-convex structure 50 (for example, 2 μm from the bottom of the concave portion). The concentration may be set to (height).

The variable refractive index layer 70 configured in this way is arranged between the first laminated substrate 100 and the second laminated substrate 200. Specifically, the insulating liquid 71 in which the first fine particles 72a and the second fine particles 72b are dispersed is sealed between the first laminated substrate 100 and the second laminated substrate 200.

The thickness of the variable refractive index layer 70 (that is, the gap between the first laminated substrate 100 and the second laminated substrate 200) is, for example, 1 μm to 100 μm, but is not limited to this. As an example, when the height of the convex portion 51 of the concave-convex structure 50 is 10 μm, the thickness of the refractive index variable layer 70 is, for example, 40 μm.

[Manufacturing method of optical device]
Next, a method of manufacturing the optical device 2 will be described with reference to FIGS. 5 and 6.

First, using, for example, a PET substrate as the first substrate 10, an ITO film is formed as the first electrode 30 on the PET substrate, and a plurality of acrylic resins (refractive index 1.5) are formed on the ITO film. The first laminated substrate 100 is manufactured by forming the concavo-convex structure 50 composed of the convex portions 51 by the imprint method.

Next, the second laminated substrate 200 is manufactured by forming the second electrode 41 and the third electrode 42 made of an ITO film on the PET substrate, for example, using a PET substrate as the second substrate 20.

Next, between the first laminated substrate 100 and the second laminated substrate 200, an insulating liquid 71 in which the first fine particles 72a and the second fine particles 72b are dispersed is filled as the refractive index variable layer 70, and the first The variable refractive index layer 70 is sealed between the first laminated substrate 100 and the second laminated substrate 200 by joining the outer peripheral portions of the laminated substrate 100 and the second laminated substrate 200.

In this way, the optical device 2 having the structure shown in FIG. 5 can be manufactured.

[Optical action of optical device]
Next, the optical action of the optical device 2 according to the embodiment will be described with reference to FIGS. 8A, 8B and 8C. FIG. 8A is a diagram for explaining the first optical action of the optical device 2 according to the second embodiment, and FIG. 8B is a diagram for explaining the second optical action of the optical device 2. FIG. 8C is a diagram for explaining the third optical action of the optical device 2.

Similar to the optical device 1 in the first embodiment, the optical device 2 in the present embodiment can be installed as, for example, a window of a building and realized as a window with a light distribution control function. Also in this embodiment, the optical device 2 is installed so that the first substrate 10 is located on the light incident side (outside the building).

At this time, the light incident on the optical device 2 receives an optical action from the optical device 2 when passing through the optical device 2. Specifically, the optical action of the optical device 2 changes depending on the change in the refractive index and the absorbance of the variable refractive index layer 70. Therefore, the light incident on the optical device 2 is subjected to different optical actions depending on the refractive index and the absorbance of the variable refractive index layer 70, and the traveling direction is changed according to the refractive index and the absorbance of the variable refractive index layer 70. It changes or the amount of light transmission changes.

In the present embodiment, the optical device 2 controls and dims the traveling direction of the light incident on the optical device 2 according to the voltages applied to the first electrode 30, the second electrode 41, and the third electrode 42. And can be done. Specifically, the particles of the first fine particles 72a and the second fine particles 72b in the variable refractive index layer 70 (fine particle dispersion layer) are subjected to the voltages applied to the first electrode 30, the second electrode 41 and the third electrode 42. The distribution changes, which partially changes the refractive index and absorbance of the variable index of refraction layer 70. As a result, the optical action of the optical device 2 changes. The optical device 2 in the present embodiment has three optical actions. Hereinafter, the three optical actions of the optical device 2 will be described in detail.

First, the first optical action of the optical device 2 will be described with reference to FIG. 8A. When no potential is applied to the first electrode 30, the second electrode 41 and the third electrode 42, that is, no voltage is applied between the first electrode 30, the second electrode 41 and the third electrode 42. In the case (when no voltage is applied), the optical device 2 enters the first optical mode and gives the first optical action to the incident light.

In the first optical mode, no electric field is applied to the variable refractive index layer 70. Therefore, as shown in FIG. 8A, in the variable refractive index layer 70, the first fine particles 72a and the second fine particles 72b cover the entire insulating liquid 71. It will be in a dispersed state. That is, the second fine particles 72b, which are light-shielding particles, are present throughout the insulating liquid 71.

In this case, as shown in FIG. 8A, when the light L1 is incident on the optical device 2 from an oblique direction, the light L1 is absorbed by the refractive index variable layer 70. Specifically, since the second fine particles 72b, which are light-shielding particles, are dispersed throughout the variable refractive index layer 70, the light L1 incident on the optical device 2 is the convex portion 51 and the concave portion (adjacent to each other) of the concave-convex structure 50. When passing through any of the two convex portions 51), the second fine particles 72b shield the light.

In this way, when no voltage is applied between the first electrode 30, the second electrode 41, and the third electrode 42, the optical device 2 blocks the light incident on the first substrate 10. That is, the first optical mode is a light-shielding mode, and in the first optical mode, the optical device 2 is in a light-shielding state.

Further, when the optical device 2 is in the light shielding mode, the light L1 incident on the optical device 2 is not always completely absorbed by the optical device 2, and is dimmed according to the absorbance of the refractive index variable layer 70. It may be transparent. In this case, since the optical device 2 in the present embodiment is provided with the concave-convex structure 50, it is incident on the optical device 2 depending on the magnitude relationship between the refractive index of the concave-convex structure 50 and the refractive index of the refractive index variable layer 70. The light L1 receives an optical action at the interface between the concave-convex structure 50 and the variable refractive index layer 70 and transmits through the optical device 2.

At this time, in the present embodiment, as described above, the refractive index of the refractive index variable layer 70 in the state where the first fine particles 72a and the second fine particles 72b are dispersed in the entire insulating liquid 71 is about 1.6. is there. Further, the refractive index of the concave-convex structure 50 is about 1.5. Therefore, when no voltage is applied between the first electrode 30, the second electrode 41, and the third electrode 42 (in the case of the first optical mode), the refractive index of the entire variable refractive index layer 70 has an uneven structure. It is higher than the refractive index of 50, and there is a difference in refractive index between the refractive index of the concave-convex structure 50 and the variable refractive index layer 70.

In this case, as shown in FIG. 8A, when light L1 is incident on the optical device 2 from an oblique direction, there is a difference in refractive index at the interface between the concave-convex structure 50 (convex portion 51) and the variable refractive index layer 70. The light L1 is refracted at the interface between the variable refractive index layer 70 and the lower side surface of the convex portion 51 and the variable refractive index layer 70, and then the upper side surface of the variable refractive index layer 70 and the convex portion 51 and the refractive index. It is totally reflected at the interface with the variable layer 70, the traveling direction is bent in the direction of rebound, and the light is emitted to the outside of the optical device 2. That is, the light L1 incident on the optical device 2 is absorbed while being distributed by the optical device 2.

Although details are not shown, refraction occurs at the interface between each member, such as the interface between the first substrate 10 and the first electrode 30, or the interface between the variable refractive index layer 70 and the second electrode 41 or the third electrode 42. Where there is a difference in rate, the light incident from the first substrate 10 will be refracted at that interface.

Next, the second optical action of the optical device 2 will be described with reference to FIG. 8B. When a potential is applied to the first electrode 30, the second electrode 41 and the third electrode 42, that is, when a voltage is applied between the first electrode 30, the second electrode 41 and the third electrode 42 ( (When the first voltage is applied), the optical device 2 enters the second optical mode and gives a second optical action to the incident light. Specifically, a DC voltage is applied between each of the first electrode 30, the second electrode 41, and the third electrode 42.

For example, in the optical device 2, when the potential applied to the first electrode 30 is V1, the potential applied to the second electrode 41 is V2, and the potential applied to the third electrode 42 is V3, in the second optical mode, The potential of each electrode is set so as to satisfy the relationship of V1> V2 and V1> V3. For example, a positive potential may be applied to the first electrode 30, and a negative potential may be applied to the second electrode 41 and the third electrode 42. As an example, V1 = −20V and V2 = V3 = + 20V.

As a result, the first fine particles 72a and the second fine particles 72b, which are charged with each other with opposite polarities, run in the insulating liquid 71 in such a manner that they are separated according to the electric field distribution generated in the variable refractive index layer 70. That is, the first fine particles 72a and the second fine particles 72b are electrophoresed in the insulating liquid 71. As a result, the first fine particles 72a and the second fine particles 72b are divided and unevenly distributed in the variable refractive index layer 70, so that the particle distributions of the first fine particles 72a and the second fine particles 72b change and the inside of the variable refractive index layer 70. The refractive index distribution and the absorbance distribution of the particles are not uniform.

Specifically, in the second optical mode, a voltage is applied between the first electrode 30, the second electrode 41, and the third electrode 42 so as to satisfy the relationship of V1> V2 = V3. The first fine particles 72a charged in the above move toward the second electrode 41 and the third electrode 42, and aggregate on the second substrate 20 side (second electrode 41 and third electrode 42 side) in the variable refractive electrode layer 70. It is unevenly distributed. At this time, the first fine particles 72a that migrated toward the second substrate 20 are accumulated in layers on the surfaces of the second electrode 41 and the third electrode 42.

As a result, in the variable refractive index layer 70, the first fine particles 72a are eliminated by the migration of the first fine particles 72a, and the concentration of the first fine particles 72a is reduced. By the migration of the one fine particle 72a, the first fine particle 72a is gathered to generate a second region 70b on the second substrate 20 side (second electrode 41 and third electrode 42 side) in which the concentration of the first fine particle 72a is increased. , A difference in refractive index occurs between the first region 70a and the second region 70b.

In this case, since the refractive index of the first fine particles 72a is higher than that of the insulating liquid 71, the refraction of the first region 70a on the concave-convex structure 50 side of the variable refractive index layer 70 in which the concentration of the first fine particles 72a is low. The rate is lower than the refractive index of the second region 70b on the second substrate 20 side of the variable refractive index layer 70 in which the concentration of the first fine particles 72a is increased. For example, the refractive index of the first region 70a on the concave-convex structure 50 side of the variable refractive index layer 70 is distributed in the thickness direction from about 1.5 to about 1.6, and the second electrode 40 side of the variable refractive index layer 70. The refractive index of the second region 60b is distributed in the thickness direction from about 1.6 to about 1.8.

Further, in the present embodiment, the variable refractive index layer 70 is formed by dispersing the first fine particles 72a composed of zirconia particles having a refractive index of 2.1 in an insulating liquid 71 having a refractive index of about 1.5. Therefore, in this second optical mode, the refractive index in the vicinity of the concave-convex structure 50 in the first region 70a on the concave-convex structure 50 side of the variable refractive index layer 70 is about 1.5. That is, the refractive index in the vicinity of the concave-convex structure 50 in the first region 70a on the concave-convex structure 50 side of the variable refractive index layer 70 is substantially the same as the refractive index of the concave-convex structure 50. As a result, the difference in refractive index between the portion near the concave-convex structure 50 in the first region 70a on the concave-convex structure 50 side of the variable refractive index layer 70 and the concave-convex structure 50 (convex portion 51) is almost eliminated (refractive index difference Δn≈0). ). The refractive index of the second region 70b on the second substrate 20 side of the variable refractive index layer 70 is about 1.8.

On the other hand, by satisfying the relationship of V1> V2 = V3, the negatively charged second fine particles 72b migrate toward the first electrode 30 to which the positive potential is applied, and the uneven structure 50 in the refractive index variable layer 70 It is aggregated and unevenly distributed on the side. At this time, the second fine particles 72b that migrate toward the first electrode 30 enter the concave portion of the concave-convex structure 50, that is, the region between the two adjacent convex portions 51 and accumulate.

At this time, since the second fine particles 72b aggregated on the concave-convex structure 50 side of the variable refractive index layer 70 enter the concave portion of the concave-convex structure 50 and accumulate, the region on the concave-convex structure 50 side of the variable refractive index layer 70 According to the unevenness of the uneven structure 50, a region having a relatively large absorbance and a region having a relatively low absorbance in the Z-axis direction are alternately generated. Specifically, the region having a relatively large absorbance is the region where the concave portion of the concave-convex structure 50 in which the second fine particles 72b are aggregated exists, and the region having a relatively low absorbance is the region where the convex portion 51 of the concave-convex structure 50 is present. It is an area that exists.

As described above, in the second optical mode, the second fine particles 72b are unevenly distributed in the first region 70a on the concave-convex structure 50 side in the variable refractive index layer 70, and the first fine particles 72a are the first in the variable refractive index layer 70. It is unevenly distributed in the second region 70b on the second substrate 20 side (second electrode 41 side).

In this case, as shown in FIG. 8B, when the light L1 is incident on the optical device 2 from an oblique direction, the light L1 is absorbed by the refractive index variable layer 70 as in the first optical mode. In the second optical mode, the second fine particles 72b, which are light-shielding particles, are accumulated in the concave portion on the concave-convex structure 50 side, and therefore receive an optical action different from that in the first optical mode. Specifically, of the light incident on the first substrate 10, the light that passes through the convex portion 51 of the concave-convex structure 50 does not pass through the region where the second fine particles 72b are aggregated (the region where the absorbance is small), so that the second The fine particles 72b pass through the variable refractive index layer 70 without being shielded from light.

At this time, in the present embodiment, since there is no difference in refractive index at the interface between the concave-convex structure 50 (convex portion 51) and the variable refractive index layer 70, the light L1 incident on the optical device 2 is the variable refractive index layer 70. At the interface between the and the side surface of the convex portion 51, the traveling direction does not change without being refracted. Therefore, the light passing through the convex portion 51 of the concave-convex structure 50 travels straight inside the optical device 2 without being bent in the traveling direction by the optical device 2, and is emitted to the outside of the optical device 2.

In this way, when a voltage is applied between the electrodes of the first electrode 30, the second electrode 41, and the third electrode 42 so as to satisfy the relationship of V1> V2 and V1> V3, the optical device 2 is subjected to the optical device 2. Of the light incident on the first substrate 10, the light passing through the convex portion 51 of the concave-convex structure 50 is made to travel straight without being shielded and is transmitted through the second substrate 20. That is, the second optical mode is a transparent mode, and in the second optical mode, the optical device 2 is in a transparent state. In this case, of the light incident on the first substrate 10, the light passing through the convex portion 51 of the concave-convex structure 50 is transmitted straight through without being distributed by the optical device 2 and emitted from the second substrate 20.

Of the light incident on the first substrate 10, the light passing through the concave portion of the concave-convex structure 50 passes through the region where the second fine particles 72b are aggregated (the region having high absorbance), and is therefore shielded by the second fine particles 72b. .. That is, a part of the light incident on the first substrate 10 is absorbed by the variable refractive index layer 70, but only the light passing through the concave portion of the concave-convex structure 50 is absorbed, so that the refractive index is variable in the second optical mode. The absorbance of the layer 70 is smaller than that of the variable refractive index layer 70 in the first optical mode, and the amount of light transmitted in the second optical mode is larger than that in the first optical mode.

Further, in the second optical mode, the refractive index of the first region 70a on the concave-convex structure 50 side of the variable refractive index layer 70 and the refractive index of the concave-convex structure 50 are substantially the same as the first region 70a of the variable refractive index layer 70. The difference in refractive index between the and the concave-convex structure 50 is 0.010 or less, more preferably 0.005 or less (Δn ≦ 0.005). When the difference in refractive index between the first region 70a of the variable refractive index layer 70 and the uneven structure 50 exceeds 0.005, light is scattered at the interface between the first region 70a of the variable refractive index layer 70 and the uneven structure 50. Haze may occur.

Although details are not shown, even in the second optical mode, the interface between the first substrate 10 and the first electrode 30, the interface between the variable refractive index layer 70 and the second electrode 41, or the third electrode 42, etc. In a place where there is a difference in refractive index at the interface between the members, the light incident from the first substrate 10 is refracted at the interface as described above.

Next, the third optical action of the optical device 2 will be described with reference to FIG. 8C. When a potential different from that in the second optical mode is applied to the first electrode 30, the second electrode 41 and the third electrode 42, that is, each of the first electrode 30, the second electrode 41 and the third electrode 42. When a voltage different from that in the second optical mode is applied between the electrodes (when a second voltage is applied), the optical device 2 enters the third optical mode, and the third optical with respect to the incident light. Gives action.

In the third optical mode, an electric field is applied to the refractive index variable layer 70 by applying a DC voltage between each of the first electrode 30, the second electrode 41, and the third electrode 42. Similarly, the variable refractive index layer 70 runs in the insulating liquid 71 in such a manner that the first fine particles 72a and the second fine particles 72b, which are charged with each other with opposite electrodes, are separated according to the electric field distribution.

Specifically, when the potential applied to the first electrode 30 is V1, the potential applied to the second electrode 41 is V2, and the potential applied to the third electrode 42 is V3, in the third optical mode, V1 < The potential of each electrode is set so as to satisfy the relationship of V2 <V3. For example, a negative potential may be applied to the first electrode 30, a ground potential may be applied to the second electrode 41, and a positive potential may be applied to the third electrode 42. As an example, V1 = −20V, V2 = 0V, V3 = + 20V.

By setting V1 <V2 <V3 in this way, as shown in FIG. 8C, the positively charged first fine particles 72a migrate toward the negative potential first electrode 30 and are negatively charged second. The fine particles 72b migrate toward the third electrode 42. As a result, the first fine particles 72a and the second fine particles 72b are divided and unevenly distributed in the variable refractive index layer 70, so that the particle distributions of the first fine particles 72a and the second fine particles 72b change and the inside of the variable refractive index layer 70. The refractive index distribution and the absorbance distribution of the particles are not uniform.

Specifically, in the third optical mode, a voltage is applied between the first electrode 30, the second electrode 41, and the third electrode 42 so as to satisfy the relationship of V1 <V2 <V3. The first fine particles 72a charged in the above move toward the first electrode 30 (first substrate 10 side) having a negative potential, and are aggregated and unevenly distributed on the uneven structure 50 side in the variable refractive index layer 70. At this time, the first fine particles 72a running toward the first electrode 30 enter the recess of the concave-convex structure 50, that is, the region between the two adjacent convex portions 51, and accumulate.

As a result, in the variable refractive index layer 70, the first fine particles 72a are gathered by the migration of the first fine particles 72a, and the concentration of the first fine particles 72a is increased. By the migration of the fine particles 72a, the first fine particles 72a disappeared, and the second region 70b on the second substrate 20 side (second electrode 41) side where the concentration of the first fine particles 72a became low was generated, and the first region 70a was generated. And the second region 70b have a difference in refractive index.

In this case, since the refractive index of the first fine particles 72a is higher than that of the insulating liquid 71, the refractive index of the first region 70a on the concave-convex structure 50 side of the variable refractive index layer 70 is the first of the variable refractive index layer 70. It is higher than the refractive index of the second region 70b on the second substrate 20 side. For example, the refractive index of the first region 70a on the concave-convex structure 50 side of the variable refractive index layer 70 is distributed in the thickness direction from about 1.8 to about 1.6, and the second electrode 40 side of the variable refractive index layer 70. The refractive index of the second region 60b is distributed in the thickness direction from about 1.6 to about 1.5.

In the present embodiment, as described above, the variable refractive index layer 70 is obtained by dispersing the first fine particles 72a composed of zirconia particles having a refractive index of 2.1 in an insulating liquid 71 having a refractive index of about 1.5. Is configured, and the refractive index of the entire variable refractive index layer 70 when no voltage is applied is about 1.6. Therefore, in the third optical mode, the first region 70a on the concave-convex structure 50 side of the variable refractive index layer 70 The refractive index of is about 1.8 to about 2.0, and the refractive index of the second region 70b on the second substrate 20 side of the variable refractive index layer 70 is about 1.5.

As a result, as described above, the refractive index of the concave-convex structure 50 is about 1.5. Therefore, in the third optical mode, the refractive index (about 1.5) of the concave-convex structure 50 and the unevenness of the variable refractive index layer 70 There is a difference in refractive index from the refractive index (about 1.8 to about 2.0) of the first region 70a on the structure 50 side. Specifically, the refractive index of the first region 70a on the concave-convex structure 50 side of the variable refractive index layer 70 is higher than the refractive index of the concave-convex structure 50.

On the other hand, by satisfying the relationship of V1 <V2 <V3, the negatively charged second fine particles 72b migrate toward the third electrode 42 to which the positive potential is applied, and are aggregated and unevenly distributed on the third electrode 42 side. To do.

As described above, in the third optical mode, the first fine particles 72a are unevenly distributed in the first region 70a on the concave-convex structure 50 side in the variable refractive index layer 70, and the second fine particles 72b are the third in the variable refractive index layer 70. It is aggregated and unevenly distributed on the three electrodes 42 side.

In this case, as shown in FIG. 8C, when light L1 is incident on the optical device 2 from an oblique direction, there is a difference in refractive index at the interface between the concave-convex structure 50 (convex portion 51) and the variable refractive index layer 70. The light L1 is refracted at the interface between the variable refractive index layer 70 and the lower side surface of the convex portion 51 and the variable refractive index layer 70, and then the upper side surface of the variable refractive index layer 70 and the convex portion 51 and the refractive index. It is totally reflected at the interface with the variable layer 70, the traveling direction is bent in the direction of rebound, and the light is emitted to the outside of the optical device 2. That is, the light L1 incident on the optical device 2 is distributed by the optical device 2.

In this way, the unevenness of the refractive index variable layer 70 is formed by applying a voltage between the first electrode 30, the second electrode 41, and the third electrode 42 so as to satisfy the relationship of V1 <V2 <V3. The refractive index of the first region 70a on the structure 50 side is higher than the refractive index of the second region 70b on the second substrate 20 side (second electrode 41) side of the variable refractive index layer 70, and the refractive index of the concave-convex structure 50 It will be higher than the rate. As a result, the optical device 2 distributes the light incident on the first substrate 10 and transmits it through the second substrate 20. That is, the third optical mode is the light distribution mode, and in the third optical mode, the optical device 2 is in the light distribution state. In this case, the light incident on the first substrate 10 is reflected by the concave-convex structure 50 of the optical device 2 as described above, the traveling direction is changed, and the light is emitted from the second substrate 20.

In the third optical mode, the second fine particles 72b, which are light-shielding particles, are aggregated on the third electrode 42, so that the light incident on the first substrate 10 that does not pass through the third electrode 42 is the third. The two fine particles 72b emit light from the second substrate 20 without being shielded from light. On the other hand, of the light incident on the first substrate 10, the light passing through the third electrode 42 passes through the second fine particles 72b aggregated on the third electrode 42, and is therefore blocked by the second fine particles 72b.

Although details are not shown, even in the third optical mode, the interface between the first substrate 10 and the first electrode 30 or the interface between the variable refractive index layer 70 and the second electrode 41 or the third electrode 42, etc. In a place where there is a difference in refractive index at the interface between the members, the light incident from the first substrate 10 is refracted at the interface as described above.

Further, when the potentials applied to the first electrode 30, the second electrode 41 and the third electrode 42 are set to zero so that no voltage is applied, the first fine particles 72a and the second fine particles 72b migrate in the insulating liquid 71. As shown in FIG. 8A, the first fine particles 72a and the second fine particles 72b return to a state in which they are uniformly dispersed throughout the insulating liquid 71.

The optical device 2 configured as described above is an active type optical control device capable of changing the optical action by controlling the refractive index matching between the concave-convex structure 50 and the refractive index variable layer 70 by an electric field. That is, the optical device 2 can be switched to a plurality of optical modes by controlling the voltage applied between the first electrode 30, the second electrode 41, and the third electrode 42. In the present embodiment, the optical device 2 can be switched to three modes: a first optical mode (light-shielding mode), a second optical mode (transparent mode), and a third optical mode (light distribution mode).

The electric field generated by the voltage applied between the first electrode 30, the second electrode 41, and the third electrode 42 is likely to be applied to the one having a lower dielectric constant. Therefore, the dielectric constant of the concave-convex structure 50 (convex portion 51) should be larger than the dielectric constant of the insulating liquid 71 of the variable refractive index layer 70. That is, it is preferable that the dielectric constant of the insulating liquid 71 is lower than that of the concave-convex structure 50 (convex portion 51). As a result, it is possible to prevent the electric field from being trapped in the concave-convex structure 50.

[Summary]
As described above, according to the optical device 2 according to the present embodiment, the concave-convex structure 50 and the refractive index variable layer 70 are arranged between the first electrode 30 and the second electrode 41, and the refractive index variable layer 70 is formed. An insulating liquid 71 (fine particle dispersion layer) in which translucent first fine particles 72a and light-shielding second fine particles 72b, which are charged with opposite polarities, are dispersed is used.

With this configuration, by applying a voltage between the first electrode 30 and the second electrode 41, the first fine particles 72a and the second fine particles 72b migrate in the insulating liquid 71, so that the refractive index variable layer 70 is refracted. The rate and absorbance can be varied. Specifically, the particle distributions of the first fine particles 72a and the second fine particles 72b in the variable refractive index layer 70 change, and the refractive index distribution and the absorbance distribution of the variable refractive index layer 70 change. As a result, the difference in refractive index between the concave-convex structure 50 and the variable refractive index layer 70 changes and the amount of light transmitted in the variable refractive index layer 70 changes, so that the traveling direction of the light incident on the optical device 2 is controlled. Or the light incident on the optical device 2 can be dimmed.

Specifically, the optical device 2 in the present embodiment can be switched to three modes: a first optical mode (light-shielding mode), a second optical mode (transparent mode), and a third optical mode (light distribution mode). it can. As a result, in the first optical mode, the light incident on the optical device 2 can be blocked, in the second optical mode, the light incident on the optical device 2 can be transmitted straight ahead, and in the third optical mode, the light incident on the optical device 2 can be transmitted in a straight line. The light incident on the optical device 2 can be distributed. Moreover, in the third optical mode, since the second fine particles 72b, which are light-shielding particles, are aggregated on the third electrode 42, the light incident on the optical device 2 can be distributed with high light transmittance.

The optical device 2 according to the present embodiment configured as described above has a large refractive index difference (Δn) between the concave-convex structure 50 and the variable refractive index layer 70 as compared with the optical device in which the variable refractive index layer is a liquid crystal layer. Therefore, the light distribution control range can be increased.

For example, when the variable refractive index layer is a liquid crystal layer, the variable refractive index layer (liquid crystal layer) has a refractive index of 1.5 because the refractive index changes only within the range of 1.5 to 1.7. The maximum difference in refractive index from the uneven structure is 0.2.

On the other hand, in the optical device 2 of the present embodiment, the variable refractive index layer 70 is formed by dispersing the first fine particles 72a having a refractive index of 2.1 in the insulating liquid 71 having a refractive index of about 1.5. Therefore, the variable refractive index layer 70 can partially change the refractive index in the range of 1.5 to 2.1. As a result, the maximum refractive index difference of the variable refractive index layer 70 from the concave-convex structure 50 having a refractive index of 1.5 is 0.6.

By increasing the difference in refractive index between the concave-convex structure 50 and the variable refractive index layer 70 in this way, the angle at which the light incident on the optical device 2 is reflected by the concave-convex structure 50 can be increased or decreased. The range (light distribution control range) that can be used can be expanded. That is, the range of the light distribution angle can be expanded.

Further, the optical device 2 in the present embodiment can improve the light distribution rate as compared with the optical device in which the variable refractive index layer is a liquid crystal layer. That is, since the liquid crystal layer is composed of liquid crystal molecules having birefringence, an optical device using the liquid crystal layer can distribute only one of S wave and P wave. On the other hand, since the insulating liquid 71 and the first fine particles 72a are independent of the S wave and the P wave, the optical device 2 in the present embodiment is independent of either the S wave or the P wave. Can also be light-distributed. Therefore, the optical device 2 in the present embodiment has twice the light distribution rate as that of the optical device using the liquid crystal layer.

As described above, according to the optical device 2 in the present embodiment, the light distribution control range can be increased and the light distribution rate can be improved as compared with the optical device in which the variable refractive index layer is a liquid crystal layer. be able to. Therefore, an optical device having excellent light distribution performance can be realized. Thereby, an optical device having a desired optical function can be realized.

Further, when the optical device 2 is in the third optical mode (light distribution mode), the first fine particles are unevenly distributed on the first electrode 30 side in order to make the entire upper side surface of the convex portion 51 of the concave-convex structure 50 a reflective surface. The 72a may exist so as to fill all the concave portions (the region between the two adjacent convex portions 51) of the concave-convex structure 50. That is, it is preferable that the first fine particles 72a exist up to the apex of the convex portion 51. In this case, the amount of the first fine particles 72a required to fill all the recesses of the concave-convex structure 50 is the first in the insulating liquid 71 according to the height of the concave-convex structure 50 and the thickness of the variable refractive index layer 70. It may be determined by adjusting the concentration of the fine particles 72a. Further, in this case, for the second fine particles 72b, the concentration and the transmittance in the insulating liquid 71 may be determined by the amount of particles required to fill the height of 2 μm from the bottom of the concave portion of the concave-convex structure 50.

(Modification example)
The optical device according to the present invention has been described above based on the embodiment, but the present invention is not limited to the above embodiment.

For example, in the above-described first and second embodiments, when the third electrode 42 is formed, the third electrode 42 is formed in the same layer as the second electrode 41, but the present invention is not limited to this, and the third electrode 42 and the second electrode 42 are formed. The electrode 41 may be formed on a different conductive layer. For example, as shown in FIG. 9, using the same second electrode 40 as in the first embodiment, the insulating layer 80 is formed on the surface of the second electrode 40, and the third electrode 42 is formed on the surface of the insulating layer 80. You may. In this case, the third electrode 42 may be formed in a grid pattern instead of a stripe shape.

Further, in the above-described first and second embodiments, when the third electrode 42 is formed, the second electrode 41 and the third electrode 42 are formed so as to extend in the X-axis direction, but the present invention is not limited to this. For example, the second electrode 41 and the third electrode 42 may be formed so as to extend in the Z-axis direction as shown in FIG. That is, the direction in which the second electrode 41 and the third electrode 42 extend may be orthogonal to the direction in which the convex portion 51 of the concave-convex structure 50 extends.

Further, in the first and second embodiments, the first electrode 30 is a solid electrode, but the present invention is not limited to this. For example, the first electrode 30 may have the same shape as the second electrode 41 and the third electrode 42. That is, the first electrode 30 may be a divided electrode divided into a plurality of parts.

Further, in the first embodiment, the second fine particles 72b are negatively charged, but the present invention is not limited to this. That is, the second fine particles 72b may be positively charged. In this case, a DC voltage may be applied between the first electrode 30 and the second electrode 40 by applying a negative potential to the first electrode 30 and a positive potential to the second electrode 40.

Further, in the second embodiment, the first fine particles 72a are positively charged and the second fine particles 72b are negatively charged, but if the first fine particles 72a and the second fine particles 72b are charged with opposite polarities, , Not limited to this. That is, the first fine particles 72a may be negatively charged and the second fine particles 72b may be positively charged. In this case, the voltage between the first electrode 30, the second electrode 41, and the third electrode 42 may be appropriately adjusted so as to have a desired potential difference relationship.

Further, in the first and second embodiments, in the second optical mode, a positive potential is applied to the first electrode 30, and a negative potential is applied to the second electrode 41 and the third electrode 42, but the present invention is not limited to this. For example, if a predetermined voltage (potential difference) is applied between the first electrode 30 and the second electrode 41 or the third electrode 42, the first electrode 30, the second electrode 41, and the third electrode are in the second optical mode. A positive potential may be applied to all of the electrodes 42, or a negative potential may be applied to all of the electrodes 42.

Further, in the first and second embodiments, the convex portion 51 constituting the concave-convex structure 50 is a long triangular prism having a triangular cross-sectional shape, but the present invention is not limited to this. For example, the convex portion 51 may be an elongated substantially quadrangular prism having a substantially trapezoidal cross section. Further, the cross-sectional shape of the side surface of the convex portion 51 is not limited to a straight line, but may be a curved line or a saw shape. Further, each of the plurality of convex portions 51 is not limited to one elongated member extending in the X-axis direction, and may be partially divided in the X-axis direction.

Further, in the first and second embodiments, the heights of the plurality of convex portions 51 are constant, but the height is not limited to this. For example, the heights of the plurality of convex portions 51 may be randomly different. Alternatively, the spacing between the protrusions 51 may be randomly different, or both the height and the spacing may be random.

Further, in the first and second embodiments, sunlight is exemplified as the light incident on the optical device, but the present invention is not limited to this. For example, the light incident on the optical device may be the light emitted by a light emitting device such as a lighting fixture.

Further, in the first and second embodiments, the optical device is arranged in the window so that the longitudinal direction of the convex portion 51 is the X-axis direction, but the present invention is not limited to this. For example, the optical device may be arranged in the window so that the longitudinal direction of the convex portion 51 is the Z-axis direction.

Further, although the optical device is attached to the window in the above-described first and second embodiments, the optical device 1 may be used as the window itself of the building. Further, the optical device is not limited to the case where it is installed in the window of a building, and may be installed in, for example, a window of a car.

In addition, in addition, a form obtained by applying various modifications to the above-described embodiment, or a combination of components and functions in each of the above-described embodiments without departing from the spirit of the present invention. The embodiment realized by the above is also included in the present invention.

1, 1A, 2 Optical devices 10 1st substrate 20 2nd substrate 30 1st electrode 40, 41 2nd electrode 42 3rd electrode 50 Concavo-convex structure 60 Dimming layer (light-shielding particle dispersion layer)
60a, 70a 1st region 60b, 70b 2nd region 70 Refractive index variable layer (fine particle dispersion layer)

Claims (21)

The first substrate with light transmission and
A light-transmitting second substrate arranged to face the first substrate and
The first electrode arranged on the second substrate side of the first substrate and
Concavo-convex structure arranged on the second substrate side of the first electrode and
The second electrode arranged on the first substrate side of the second substrate and
A dimming layer which is arranged between the uneven structure and the second electrode and whose absorbance changes according to the voltage applied between the first electrode and the second electrode is provided.
The light control layer has an insulating liquid and charged light-shielding particles dispersed in the insulating liquid.
Optical device. When a voltage is applied between the first electrode and the second electrode, the region on the concave-convex structure side of the dimming layer is relative to the region having a relatively large absorbance according to the concave-convex structure. Areas with low absorbance are alternately generated.
The optical device according to claim 1. Further, a third electrode arranged on the first substrate side of the second substrate is provided.
Assuming that the potential applied to the first electrode is V1, the potential applied to the second electrode is V2, and the potential applied to the third electrode is V3, the absorbance of the dimming layer when V1 <V2 <V3. Is smaller than the absorbance of the dimming layer when V1> V2 and V3.
The optical device according to claim 2. An optical device that controls incident light
The first substrate with light transmission and
A light-transmitting second substrate arranged to face the first substrate and
The first electrode arranged on the second substrate side of the first substrate and
Concavo-convex structure arranged on the second substrate side of the first electrode and
The second electrode arranged on the first substrate side of the second substrate and
A light-shielding particle dispersion layer arranged between the uneven structure and the second electrode and having an insulating liquid and charged light-shielding particles dispersed in the insulating liquid is provided.
The optical device controls dimming of light incident on the optical device according to a voltage applied between the first electrode and the second electrode.
Optical device. The optical device is
When no voltage is applied between the first electrode and the second electrode, the light incident on the first substrate is blocked.
When a voltage is applied between the first electrode and the second electrode, the light incident on the first substrate that passes through the uneven structure is transmitted without shading.
The optical device according to claim 4. Further, a third electrode arranged on the first substrate side of the second substrate is provided.
Assuming that the potential applied to the first electrode is V1, the potential applied to the second electrode is V2, and the potential applied to the third electrode is V3, when V1 <V2 <V3, the optical device is described. Of the light incident on the first substrate, the light passing through the second electrode is transmitted without shading, and among the light incident on the first substrate, the light passing through the third electrode is blocked.
The optical device according to claim 5. The first substrate with light transmission and
A light-transmitting second substrate arranged to face the first substrate and
The first electrode arranged on the second substrate side of the first substrate and
Concavo-convex structure arranged on the second substrate side of the first electrode and
The second electrode arranged on the first substrate side of the second substrate and
A light-shielding particle dispersion layer arranged between the uneven structure and the second electrode and having an insulating liquid and charged light-shielding particles dispersed in the insulating liquid is provided.
The particle distribution of the light-shielding particles in the light-shielding particle dispersion layer changes according to the voltage applied between the first electrode and the second electrode.
Optical device. When a voltage is applied between the first electrode and the second electrode, the light-shielding particles are unevenly distributed on the uneven structure side in the light-shielding particle dispersion layer.
The optical device according to claim 7. Further, a third electrode arranged on the first substrate side of the second substrate is provided.
Assuming that the potential applied to the first electrode is V1, the potential applied to the second electrode is V2, and the potential applied to the third electrode is V3, when V1 <V2 <V3, the light-shielding particles are described as described above. Aggregated and unevenly distributed on the third electrode,
The optical device according to claim 8. The first substrate with light transmission and
A light-transmitting second substrate arranged to face the first substrate and
The first electrode arranged on the second substrate side of the first substrate and
Concavo-convex structure arranged on the second substrate side of the first electrode and
The second electrode arranged on the first substrate side of the second substrate and
A refractive index variable layer arranged between the uneven structure and the second electrode, in which at least one of the absorbance and the refractive index changes according to the voltage applied between the first electrode and the second electrode. With
The variable refractive index layer has an insulating liquid and first and second fine particles contained in the insulating liquid.
The first fine particles are charged with the first polarity and are charged.
The second fine particles have a light-shielding property and are charged with a second polarity opposite to the first polarity.
The refractive index of the first fine particles is higher than the refractive index of the insulating liquid.
Optical device. When a voltage is applied between the first electrode and the second electrode, the region on the concave-convex structure side of the dimming layer is relative to the region having a relatively large absorbance according to the concave-convex structure. Areas with low absorbance are alternately generated.
The optical device according to claim 10. When a voltage is applied between the first electrode and the second electrode, the refractive index of the first region on the concave-convex structure side of the variable refractive index layer is the second electrode of the variable refractive index layer. It is lower than the refractive index of the second region on the side and is substantially the same as the refractive index of the uneven structure.
The optical device according to claim 10 or 11. Further, a third electrode arranged on the first substrate side of the second substrate is provided.
Assuming that the potential applied to the first electrode is V1, the potential applied to the second electrode is V2, and the potential applied to the third electrode is V3, when V1 <V2 <V3, the refractive index variable layer The refractive index of the first region on the concave-convex structure side is higher than the refractive index of the second region on the second electrode side of the variable refractive index layer, and is higher than the refractive index of the concave-convex structure.
The optical device according to claim 12. An optical device that controls incident light
The first substrate with light transmission and
A light-transmitting second substrate arranged to face the first substrate and
The first electrode arranged on the second substrate side of the first substrate and
Concavo-convex structure arranged on the second substrate side of the first electrode and
The second electrode arranged on the first substrate side of the second substrate and
An insulating liquid and a fine particle dispersion layer having first fine particles and second fine particles dispersed in the insulating liquid are provided between the uneven structure and the second electrode.
The first fine particles are charged with the first polarity and are charged.
The second fine particles have a light-shielding property and are charged with a second polarity opposite to the first polarity.
The optical device controls at least one of the traveling direction and dimming of light incident on the optical device according to the voltage applied between the first electrode and the second electrode.
Optical device. When no voltage is applied between the first electrode and the second electrode, the optical device blocks the light incident on the first substrate.
The optical device according to claim 14. When a voltage is applied between the first electrode and the second electrode, the optical device causes light incident on the first substrate to travel straight through the second substrate.
The optical device according to claim 14 or 15. Further, a third electrode arranged on the first substrate side of the second substrate is provided.
Assuming that the potential applied to the first electrode is V1, the potential applied to the second electrode is V2, and the potential applied to the third electrode is V3, when V1 <V2 <V3, the optical device is described. The light incident on the first substrate is distributed and transmitted through the second substrate.
The optical device according to any one of claims 14 to 16. The first substrate with light transmission and
A light-transmitting second substrate arranged to face the first substrate and
The first electrode arranged on the second substrate side of the first substrate and
Concavo-convex structure arranged on the second substrate side of the first electrode and
The second electrode arranged on the first substrate side of the second substrate and
An insulating liquid and a fine particle dispersion layer having first fine particles and second fine particles dispersed in the insulating liquid are provided between the uneven structure and the second electrode.
The first fine particles are charged with the first polarity and are charged.
The second fine particles have a light-shielding property and are charged with a second polarity opposite to the first polarity.
The particle distribution of the first fine particles and the second fine particles in the fine particle dispersion layer changes according to the voltage applied between the first electrode and the second electrode.
Optical device. When the first voltage is applied between the first electrode and the second electrode, the second fine particles are unevenly distributed in the first region on the uneven structure side in the fine particle dispersion layer, and the first. The fine particles are unevenly distributed in the second region on the second electrode side in the fine particle dispersion layer.
The optical device according to claim 18. Further, a third electrode arranged on the first substrate side of the second substrate is provided.
Assuming that the potential applied to the first electrode is V1, the potential applied to the second electrode is V2, and the potential applied to the third electrode is V3, when V1 <V2 <V3, the first fine particles are: The second fine particles are unevenly distributed in the first region on the uneven structure side in the fine particle dispersion layer, and the second fine particles are aggregated and unevenly distributed on the third electrode side in the fine particle dispersion layer.
The optical device according to claim 18 or 19. The total area of the third electrode is smaller than the total area of the second electrode.
The optical device according to any one of claims 3, 6, 9, 13, 17 and 20.

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