WO2020066709A1

WO2020066709A1 - Optical device

Info

Publication number: WO2020066709A1
Application number: PCT/JP2019/036180
Authority: WO
Inventors: 伊藤　宜弘; 一樹北村; 拓磨白井
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2018-09-27
Filing date: 2019-09-13
Publication date: 2020-04-02

Abstract

This optical device is provided with: a light distribution device (2) which distributes incident light; and a container. The light distribution device (2) is provided with: a first substrate (10) that has light transmitting properties; a second substrate (20) that is arranged so as to face the first substrate (10) and has light transmitting properties; a recessed and projected structure layer (30) that is arranged on the first substrate (10) side of the second substrate (20) and has light transmitting properties; and a gap part (40) that is provided between the recessed and projected structure layer (30) and the first substrate (10). The container contains a liquid (7) which is injected into the gap part (40) and is discharged from the gap part (40).

Description

Optical device

<< The present invention relates to an optical device.

Patent Document 1 discloses a structure provided with a mechanism for supplying and discharging a liquid to a retroreflective structure. In the structure described in Patent Document 1, when a liquid is supplied to the retroreflective structure, the structure becomes a transmission state, and when the liquid is not supplied, the structure becomes a reflection state, that is, a light-blocking state.

JP 2017-58605 A

した When the above-mentioned conventional structure is used for a window, the structure simply transmits light. For this reason, even if a conventional structure is used for a window, light cannot be efficiently introduced indoors.

Therefore, an object of the present invention is to provide an optical device that can efficiently take in light indoors when used in a window.

In order to achieve the above object, an optical device according to one embodiment of the present invention includes a light distribution device that distributes incident light and a container, and the light distribution device has a first substrate having a light-transmitting property. A light-transmitting second substrate disposed opposite to the first substrate, a light-transmitting concavo-convex structure layer disposed on the first substrate side of the second substrate, and the concavo-convex structure layer And a gap provided between the first substrate and the first substrate, wherein the container accommodates a liquid injected into the gap and discharged from the gap.

According to the optical device of the present invention, when it is used for a window, light can be efficiently introduced indoors.

FIG. 1 is a schematic diagram illustrating a configuration of an optical device according to an embodiment. FIG. 2 is a cross-sectional view of the light distribution device of the optical device according to the embodiment. FIG. 3A is a cross-sectional view illustrating a state in which a liquid is injected into a gap of a light distribution device of the optical device according to the embodiment. FIG. 3B is a cross-sectional view illustrating a state where the liquid is discharged from the gap of the light distribution device of the optical device according to the embodiment. FIG. 3C is a cross-sectional view illustrating a state where the liquid is completely discharged from the gap of the light distribution device of the optical device according to the embodiment. FIG. 4A is a cross-sectional view illustrating a transparent state of the light distribution device of the optical device according to the embodiment. FIG. 4B is a cross-sectional view illustrating a light distribution state of the light distribution device of the optical device according to the embodiment. FIG. 5A is a cross-sectional view showing a transparent state of the light distribution device of the optical device according to the first modification of the embodiment. FIG. 5B is a cross-sectional view illustrating a light distribution state of the light distribution device of the optical device according to the first modification of the embodiment. FIG. 6 is a cross-sectional view of a light distribution device of an optical device according to Modification 2 of the embodiment.

Hereinafter, an optical device according to an embodiment of the present invention will be described in detail with reference to the drawings. Each of the embodiments described below shows a specific example of the present invention. Therefore, numerical values, shapes, materials, constituent elements, arrangement and connection forms of constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and do not limit the present invention. Therefore, among the components in the following embodiments, components not described in the independent claims are described as arbitrary components.

図 Moreover, each drawing is a schematic diagram and is not necessarily strictly illustrated. Therefore, for example, the scales and the like do not always match in each drawing. Further, in each of the drawings, substantially the same configuration is denoted by the same reference numeral, and redundant description will be omitted or simplified.

Also, in this specification, terms indicating relationships between elements such as parallel or vertical, and terms indicating the shape of elements such as triangles or trapezoids, and numerical ranges are not expressions expressing only strict meanings, Is a meaning that includes a substantially equivalent range, for example, a difference of about several percent.

In addition, in this specification and the drawings, the X axis, the Y axis, and the Z axis indicate three axes of a three-dimensional orthogonal coordinate system. In each embodiment, the Z-axis direction is the vertical direction, and the direction perpendicular to the Z-axis (the direction parallel to the XY plane) is the horizontal direction. Note that the positive direction of the Z axis is defined as vertically upward. Further, in the present specification, the "thickness direction" means the thickness direction of the light distribution device, is a direction perpendicular to the main surface of the first substrate and the second substrate, "plan view", This refers to a state when viewed from a direction perpendicular to the main surface of the first substrate or the second substrate.

(Embodiment)
[Constitution]
First, the configuration of the optical device according to the embodiment will be described with reference to FIGS. FIG. 1 is a schematic diagram illustrating a configuration of an optical device 1 according to the present embodiment. FIG. 2 is a cross-sectional view of the light distribution device 2 of the optical device 1 according to the present embodiment.

As shown in FIG. 1, the optical device 1 includes a light distribution device 2 and a container 3. In the present embodiment, the optical device 1 further includes a pipe 4, a liquid feeding device 5, and a flow sensor 6. In FIG. 1, only the light distribution device 2 is illustrated in a plan view, and the connection relationship among the container 3, the pipe 4, the liquid feed device 5, and the flow sensor 6 is schematically illustrated.

The light distribution device 2 is a light control device that controls light incident on the light distribution device 2. Specifically, when transmitting the light incident on the light distribution device 2, the light distribution device 2 changes the traveling direction of the incident light and emits the light.

In the present embodiment, as shown in FIG. 2, the light distribution device 2 includes a first substrate 10, a second substrate 20, an uneven structure layer 30, a gap 40, and a sealing member 50. . The light distribution device 2 transmits light incident on the first substrate 10 and emits the light from the second substrate 20. The first substrate 10, the gap 40, the uneven structure layer 30, and the second substrate 20 are arranged in this order along the thickness direction.

In the present embodiment, as shown in FIG. 2, the optical device 1 includes the liquid 7 capable of filling the gap 40. The optical device 1 controls the injection of the liquid 7 into the gap portion 40 and the discharge of the liquid 7 from the gap portion 40, so that the refractive index difference between the surface of the uneven structure layer 30 and the medium in contact with the surface is controlled. Can be changed.

Specifically, when the liquid 7 is injected into the gap 40, the liquid 7 becomes a medium that comes into contact with the surface of the uneven structure layer 30. The refractive index difference between the liquid 7 and the uneven structure layer 30 becomes substantially equal, and the optical state of the light distribution device 2 becomes transparent. When the liquid 7 is discharged from the gap 40, the air 8 (see FIG. 3A) introduced into the gap 40 instead of the discharged liquid 7 becomes a medium that comes into contact with the surface of the uneven structure layer 30. . The refractive index difference between the air 8 and the uneven structure layer 30 increases, and the optical state of the light distribution device 2 becomes a light distribution state.

In the present embodiment, “light distribution” means that, when transmitting incident light incident on the light distribution device 2, the traveling direction is bent in a specific direction and emitted. For example, when the light distribution device 2 is arranged upright along the vertical direction, when transmitting light traveling obliquely downward, the light distribution device 2 totally reflects the light and emits obliquely upward. . The specific optical action of the light distribution device 2 will be described later.

光 The light distribution device 2 can be realized as a window with a light distribution function by being installed in a window of a building, for example. The light distribution device 2 is used by attaching it to a transparent base material such as an existing window glass through an adhesive layer, for example. Alternatively, the light distribution device 2 may be used as a window of a building itself. The light distribution device 2 is arranged, for example, such that the first substrate 10 is on the outdoor side and the second substrate 20 is on the indoor side.

具体 The specific configuration of the light distribution device 2 will be described later.

The container 3 is a container for containing the liquid 7. As shown in FIG. 1, the container 3 is connected to the light distribution device 2 via a pipe 4. Specifically, as shown in FIG. 2, the pipe 4 is connected to an opening 54 provided in the sealing member 50 of the light distribution device 2. Note that the container 3 may be directly connected to the opening 54 of the light distribution device 2. That is, the optical device 1 does not need to include the pipe 4.

容量 The capacity of the container 3 is, for example, not less than the capacity of the gap 40. Thereby, the container 3 can completely contain the liquid 7 injected into the gap 40. That is, the liquid 7 can be completely discharged from the gap 40. The size and shape of the container 3 are not particularly limited. The container 3 and the pipe 4 are formed using, for example, a resin material or a metal material. The container 3 and the pipe 4 are formed using, for example, a material that does not react with the liquid 7.

When the light distribution device 2 is used for a window of a building, the container 3 and the pipe 4 are provided, for example, embedded in a window frame, a wall, a floor or a ceiling of the building. Alternatively, the container 3 and the pipe 4 may be provided indoors or outdoors of a building.

液 The liquid sending device 5 performs at least one of the injection of the liquid 7 into the gap 40 and the discharge of the liquid 7 from the gap 40. In the present embodiment, the liquid sending device 5 performs both the injection of the liquid 7 into the gap 40 and the discharge of the liquid 7 from the gap 40.

Note that either the injection or the discharge of the liquid 7 may be performed using the weight of the liquid 7. Specifically, when the container 3 is provided at a position higher than the gap 40, the injection of the liquid 7 from the container 3 into the gap 40 is easily performed by the weight of the liquid 7. When the container 3 is provided at a position lower than the gap 40, the discharge of the liquid 7 from the gap 40 to the container 3 is easily performed by the weight of the liquid 7. As described above, the liquid feeding device 5 does not have to perform one of the injection and the discharge of the liquid 7 into and from the gap 40.

The liquid supply device 5 is, for example, a liquid pump capable of adjusting the flow rate of the liquid 7 flowing through the pipe 4. The liquid feeding device 5 adjusts at least one of the injection amount and the discharge amount of the liquid 7 based on the flow rate measured by the flow sensor 6.

Specifically, the liquid feeding device 5 calculates the total amount of the liquid 7 injected into the gap portion 40 using the flow rate measured by the flow rate sensor 6, and when the calculated total amount reaches the first value. Then, the injection of the liquid 7 is stopped. The first value is a value equal to or less than the capacity of the gap 40. For example, when the first value is half of the capacity of the gap 40, a state where the lower half of the gap 40 is filled with the liquid 7 and the upper half is not filled with the liquid 7 can be formed. Thereby, the optical state of the light distribution device 2 can be made different for each region.

Similarly, the liquid feeding device 5 calculates the total amount of the liquid 7 discharged from the gap portion 40 using the flow rate measured by the flow rate sensor 6, and when the calculated total amount reaches the second value, The discharge of the liquid 7 is stopped. The second value is a value equal to or less than the capacity of the gap 40. For example, when the second value is 1/3 of the capacity of the gap 40, the lower 2/3 of the gap 40 is filled with the liquid 7, and the upper 1/3 is not filled with the liquid 7. A state can be formed. Thereby, the optical state of the light distribution device 2 can be made different for each region. The first value and the second value are respectively the capacity (maximum value) of the gap 40, or half, 1/3, 2/3, 1/4 or 3/4 of the capacity of the gap 40. However, it is not limited to these.

The flow rate sensor 6 measures the flow rate of the liquid 7 flowing between the container 3 and the gap 40. Specifically, the flow sensor 6 is provided in the pipe 4 and measures the flow rate of the liquid 7 flowing in the pipe 4. In addition, the optical device 1 may have a configuration capable of managing the flow rate instead of the flow rate sensor 6.

The liquid 7 is a liquid that is injected into the gap 40 and discharged from the gap 40. That is, after the liquid 7 is injected into the gap 40 at the first timing, it is discharged from the gap 40 at the second timing. The discharged liquid 7 is stored in the container 3. The discharged liquid 7 is injected into the gap 40 at a third timing. That is, the liquid 7 is repeatedly injected and discharged from the gap 40.

体積 The volume of the liquid 7 is, for example, equal to the volume of the gap 40. Thus, the gap 40 can be completely filled with the liquid 7. Note that the volume of the liquid 7 may be smaller or larger than the volume of the gap 40.

In the present embodiment, the liquid 7 has a refractive index substantially equal to the refractive index of the uneven structure layer 30 of the light distribution device 2. Specifically, when the refractive index of the uneven structure layer 30 is n1 and the refractive index of the liquid 7 is n2, the absolute value of n1−n2 is 0.01 or less.

The liquid 7 is, for example, silicone oil. The refractive index of the silicone oil is, for example, in the range of 1.5 or more and 1.6 or less. Alternatively, the liquid 7 may be water having a refractive index of about 1.33 or alcohol having a refractive index of about 1.3. The water may be pure water, tap water or sugar water. Alternatively, the liquid 7 may be an aqueous solution containing nanoparticles or an organic material having a high refractive index.

The liquid 7 has a surface tension of 20 mN / m or more and 76 mN / m or less. Specifically, the liquid 7 has a surface tension of 20 mN / m to 76 mN / m in a range of 0 ° C to 40 ° C. When the surface tension is 20 mN or more, the liquid 7 can be easily injected into and discharged from the gap 40. For example, it is possible to suppress the remaining of the liquid 7 at the time of discharging, and to suppress the incorporation of bubbles into the liquid 7 at the time of injection. Thereby, the uniformity of the optical state in the plane of the light distribution device 2 can be improved.

Next, a specific configuration of the light distribution device 2 will be described.

[First substrate]
The first substrate 10 is a transparent base material. As the first substrate 10, for example, a glass substrate or a resin substrate can be used.

材料 Examples of the material of the glass substrate include soda glass, non-alkali glass, and high refractive index glass. Examples of the material of the resin substrate include resin materials such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), acrylic (PMMA), and epoxy. The glass substrate has the advantages of high light transmittance and low moisture permeability. On the other hand, the resin substrate has an advantage that scattering at the time of destruction is small. In the present embodiment, the first substrate 10 is a transparent glass substrate.

The first substrate 10 is, for example, a rigid substrate, but may be a flexible substrate. The thickness of the first substrate 10 is, for example, 3 mm or more and 6 mm or less, but is not limited thereto. The planar shape of the first substrate 10 is, for example, a rectangle or a square, but is not limited thereto, and may be a polygon other than a rectangle or a circle.

[Second substrate]
The second substrate 20 is a transparent base material. The second substrate 20 is arranged to face the first substrate 10. The second substrate 20 and the first substrate 10 are arranged in parallel with each other, and an interval between them is, for example, 1 mm.

In the present embodiment, as shown in FIG. 2, the second substrate 20 includes a glass substrate 21, a film substrate 22, and an adhesive layer 23. It has a laminated structure in which a glass substrate 21, an adhesive layer 23, and a film substrate 22 are laminated in this order. Note that the second substrate 20 may have a single-layer structure, similarly to the first substrate 10. For example, the second substrate 20 may include only the glass substrate 21 or may include only the film substrate 22.

The glass substrate 21 is a transparent glass substrate and has, for example, the same configuration as the first substrate 10. Specifically, the thickness of the glass substrate 21 is, for example, not less than 3 mm and not more than 6 mm, but is not limited thereto. The glass substrate 21 is, for example, a rigid substrate, but may be a flexible substrate. The shape of the glass substrate 21 in a plan view is, for example, a rectangle or a square, but is not limited thereto, and may be a polygon other than a rectangle or a circle. Examples of the material of the glass substrate 21 include soda glass, non-alkali glass, and high refractive index glass.

The film substrate 22 is a light-transmitting resin substrate. Examples of the material of the resin substrate include resin materials such as PET, PEN, PC, PMMA, and epoxy. In the present embodiment, the film substrate 22 is a transparent resin substrate made of PET resin. The thickness of the film substrate 22 is, for example, 1 μm or more and 1000 μm or less, but is not limited thereto. The planar shape of the film substrate 22 is the same as the planar shape of the glass substrate 21.

凹凸 As shown in FIG. 2, the uneven structure layer 30 is provided on the main surface of the film substrate 22 on the first substrate 10 side. The film substrate 22 is a member serving as a support substrate when forming the uneven structure layer 30.

The adhesive layer 23 fixes the glass substrate 21 and the film substrate 22. The adhesive layer 23 is formed using, for example, a translucent resin material. The adhesive layer 23 is, for example, a silicone resin, but is not limited thereto.

In the present embodiment, the first substrate 10 and the second substrate 20 are bonded to each other by a sealing member 50 provided in a frame shape along the outer periphery of each end. Between the first substrate 10 and the second substrate 20, a plurality of particulate spacers may be dispersed in the plane or a columnar structure may be formed in order to keep the distance constant. .

[Rough structure layer]
The concavo-convex structure layer 30 is a fine-shaped layer arranged on the first substrate 10 side of the second substrate 20. The uneven structure layer 30 has a plurality of convex portions 31 as shown in FIG.

Specifically, the concavo-convex structure layer 30 is a concavo-convex structure formed of a plurality of protrusions 31 having a micro-order size. In the example illustrated in FIG. 2, the plurality of protrusions 31 are individually separated from each other, and are supported by the base layer at the base (the second substrate 20 side). That is, a flat surface is provided between two adjacent protrusions 31. The base layer is, for example, a portion left as a residual film when the plurality of protrusions 31 are molded. The plurality of protrusions 31 may be connected to each other at the root, and a flat surface may not be provided between two adjacent protrusions 31. That is, the cross-sectional shape of the concave portion between two adjacent convex portions 31 may be V-shaped. For example, the concavo-convex structure layer 30 is provided in contact with the surface of the second substrate 20 on the first substrate 10 side without interposing other members such as an electrode layer. Note that a transparent adhesive layer or the like may be provided between the uneven structure layer 30 and the second substrate 20.

The plurality of convex portions 31 are arranged side by side in the Z-axis direction. The plurality of protrusions 31 are long protrusions extending in a direction orthogonal to the arrangement direction (that is, the Z-axis direction). Specifically, the plurality of convex portions 31 are formed in a stripe shape extending in the X-axis direction. In FIG. 1, the plurality of projections 31 are schematically shown by solid-line stripes. For example, each of the plurality of protrusions 31 is a triangular prism arranged sideways with respect to the second substrate 20. Note that the plurality of convex portions 31 may extend while meandering along the X-axis direction. For example, the plurality of convex portions 31 may be formed in a wavy stripe shape in plan view.

よう As shown in FIG. 2, each of the plurality of protrusions 31 has a shape that tapers from the root to the tip. Specifically, the cross-sectional shape of each of the plurality of protrusions 31 is a tapered shape that tapers along the direction from the second substrate 20 to the first substrate 10. In the present embodiment, the cross-sectional shape of the plurality of protrusions 31 in the YZ cross section is a triangle that tapers along the thickness direction of the light distribution device 2, but is not limited thereto. The cross-sectional shape of the convex portion 31 may be a trapezoid, another polygon, a polygon including a curve, or the like.

台 Note that the trapezoid or triangle also includes a trapezoid or triangle whose vertices are rounded. In addition, the trapezoid or triangle may include a case where each side is not completely straight, for example, a case where each side is slightly bent with a displacement of about several percent of the length of each side, or a case where minute irregularities are included. included.

凸 As shown in FIG. 2, each of the plurality of projections 31 has side surfaces 32 and 33. The side surfaces 32 and 33 are surfaces that intersect in the Z-axis direction. At least one of the side surfaces 32 and 33 is an inclined surface inclined at a predetermined inclination angle with respect to the Y-axis direction. The distance between the side surface 32 and the side surface 33, that is, the width of the protrusion 31 gradually decreases from the second substrate 20 toward the first substrate 10.

The side surface 32 is, for example, a vertically upper side surface among a plurality of side surfaces constituting the convex portion 31 when the light distribution device 2 is arranged so that the Z axis coincides with the vertical direction. The side surface 32 is a refraction surface that refracts incident light.

The side surface 33 is, for example, a vertically lower side surface among a plurality of side surfaces constituting the convex portion 31 when the light distribution device 2 is arranged so that the Z axis coincides with the vertical direction. The side surface 33 is a reflection surface that reflects incident light. The reflection here is total reflection, and the side surface 33 functions as a total reflection surface.

傾斜 The inclination angles of the side surfaces 32 and 33 are, for example, in a range of 0 ° or more and 25 ° or less. In other words, the two base angles of the triangle or the trapezoid, which are the cross-sectional shapes of the protrusions 31, are each 65 ° or more and 90 ° or less. The inclination angle of the side surface 32 and the inclination angle of the side surface 33 may be different from each other or may be equal. The inclination angles of the side surfaces 32 of the plurality of convex portions 31 may be equal to each other or may be different. The inclination angles of the side surfaces 33 of the plurality of convex portions 31 may be equal to each other or may be different.

各々 The height of each of the plurality of projections 31 is, for example, 100 μm or more. When the height is 100 μm or more, a wide side surface 33 that reflects light can be secured. For this reason, the amount of light to be distributed increases, so that the light distribution rate can be increased.

The aspect ratio of each of the plurality of projections 31 is, for example, 2 or less. The aspect ratio is the ratio of the height to the width of the root of the convex portion 31. When the aspect ratio is 2 or less, the physical strength of the projection 31 can be increased. For example, at the time of injecting and discharging the liquid 7, it is possible to suppress a change in the shape of the projection 31 due to the flow of the liquid 7.

{Circle around (2)} The interval between two adjacent protrusions 31 is, for example, 10 μm or more and 40 μm or less. The interval is a distance between the roots of two adjacent convex portions 31. That is, the interval corresponds to the width of the flat surface of the concave portion between two adjacent convex portions 31. When the interval between two adjacent convex portions 31 is 10 μm or more, the liquid 7 injected into the gap portion 40 is less likely to remain in the concave portion. Therefore, the liquid 7 can be quickly discharged. Further, when the interval between two adjacent convex portions 31 is 40 μm or less, the in-plane density of the convex portions 31 having the side surfaces 33 that reflect light can be increased. For this reason, the amount of light to be distributed increases, so that the light distribution rate can be increased.

The height of each of the plurality of protrusions 31 may be 1 mm or more. That is, the plurality of protrusions 31 may be protrusions of a millimeter order size. Even if the injected liquid 7 remains partially without being completely discharged, a sufficiently large reflecting surface can be secured as a whole.

In the present embodiment, the shapes of the plurality of protrusions 31 are the same as each other, but may be different. For example, the plurality of protrusions 31 may include a plurality of protrusions having different heights. For example, the heights of two adjacent protrusions 31 may be different. The height of each of the plurality of protrusions 31 may be, for example, a value randomly selected from among a plurality of set values.

The uneven structure layer 30 is formed using, for example, an ultraviolet curable resin material. Specifically, the uneven structure layer 30 can be formed by molding, nanoimprinting, or the like.

、 As a material of the uneven structure layer 30, for example, a resin material using light transmittance such as an acrylic resin, an epoxy resin, or a silicone resin can be used. The refractive index of the uneven structure layer 30 is, for example, in a range of 1.4 or more and 1.8 or less. In the present embodiment, the uneven structure layer 30 is formed using, for example, an acrylic resin having a refractive index of about 1.5.

The contact angle of the surface of the uneven structure layer 30 with the liquid 7 is, for example, not less than 60 ° and not more than 120 °. The contact angle may be 90 ° or more and 120 ° or less. That is, each of the side surfaces 32 and 33 of the convex portion 31 has liquid repellency (specifically, oil repellency or water repellency) or super liquid repellency with respect to the liquid 7. For example, the surface of the concavo-convex structure layer 30 may be coated with fluorine. Alternatively, in the molecular structure of the surface of the uneven structure layer 30, a fluorine-based functional group may be introduced. Note that a fluorine-based functional group may be introduced into the molecular structure of the liquid 7.

The surface of the uneven structure layer 30 may have lyophilicity (specifically, lipophilicity or hydrophilicity) or superhydrophilicity with respect to the liquid 7. For example, the contact angle of the surface of the uneven structure layer 30 with the liquid 7 may be less than 60 °. For example, the contact angle may be 40 ° or more.

[Gap]
The gap portion 40 is provided between the uneven structure layer 30 and the first substrate 10. The gap portion 40 is, specifically, a space surrounded by the first substrate 10, the uneven structure layer 30, and the sealing member 50.

液体 The liquid 7 is injected into the gap 40. The injected liquid 7 contacts and covers the surface of the uneven structure layer 30, specifically, the side surfaces 32 and 33 of the convex portion 31. In the present embodiment, since the refractive index n2 of the liquid 7 is substantially equal to the refractive index n1 of the uneven structure layer 30, the difference in refractive index between the liquid 7 and the uneven structure layer 30 is sufficiently small. Accordingly, light passing through the gap portion 40 and the uneven structure layer 30 travels substantially straight without being subjected to optical actions such as reflection and refraction on the surface of the uneven structure layer 30.

(4) After the liquid 7 is discharged, the gap 40 is filled with, for example, air. When the liquid 7 is discharged from the gap 40, the difference in the refractive index between the gap 40 (that is, air) and the uneven structure layer 30 increases. Thereby, the light passing through the gap portion 40 and the uneven structure layer 30 is totally reflected by the side surface 33 of the convex portion 31 and emitted in a direction different from the incident direction.

The difference in the optical state depending on the presence or absence of the liquid 7 in the gap 40 will be described later in detail.

[Sealing member]
The sealing member 50 is a ring-shaped member for forming a space for sealing the liquid 7 between the first substrate 10 and the second substrate 20, that is, a gap 40. Specifically, the sealing member 50 is provided along each end of the first substrate 10 and the second substrate 20. Since the planar shape of each of the first substrate 10 and the second substrate 20 is rectangular, the sealing member 50 is provided in a rectangular ring shape. That is, the sealing members 50 are provided along the four sides of each of the first substrate 10 and the second substrate 20 in plan view.

The sealing member 50 adheres the first substrate 10 and the second substrate 20 at a peripheral portion. By this bonding, the gap 40 is formed.

In the present embodiment, as shown in FIG. 2, the sealing member 50 has a spacer 51 and

adhesive layers

52 and 53. Further, the sealing member 50 has an opening 54 and an air hole 55.

The spacer 51 is a member for maintaining a distance between the first substrate 10 and the second substrate 20. The spacer 51 is formed using, for example, a resin material such as PET. Alternatively, the spacer 51 may be a metal material. The spacer 51 has a uniform thickness and is provided in a rectangular ring shape in plan view. The spacer 51 may be formed of four linear members corresponding to each of the four sides of the first substrate 10 or the second substrate 20.

The bonding layer 52 bonds the spacer 51 and the first substrate 10 together. The bonding layer 53 bonds the spacer 51 and the second substrate 20 together. The adhesive layers 52 and 53 are formed using an adhesive resin material. For example, a thermosetting resin is used as a resin material for forming the

adhesive layers

52 and 53. The adhesive layers 52 and 53 are provided in a rectangular ring shape along the outer periphery of the first substrate 10 and the second substrate 20, respectively.

The opening 54 is an inlet and an outlet for the liquid 7. The opening 54 is provided to penetrate the spacer 51, and the pipe 4 is connected. The opening 54 is provided in, for example, a lower end surface of the light distribution device 2. In the present embodiment, the liquid 7 is injected from below the light distribution device 2 and discharged from below.

The opening 54 may be provided on the upper end face of the light distribution device 2. That is, the liquid 7 may be injected from above the light distribution device 2 and discharged from above. Further, the opening 54 may be provided on a side end surface of the light distribution device 2. Alternatively, the opening 54 may be provided through one of the first substrate 10 and the second substrate 20.

The air hole 55 is a hole for taking in and out the air in the gap 40. The air hole 55 is provided to penetrate the spacer 51. The air hole 55 may be provided with a filter that suppresses the permeation of the liquid 7 and allows the gas to pass so that the liquid 7 does not leak. The air hole 55 is provided on the upper end face of the light distribution device 2.

[motion]
Subsequently, the operation of the optical device 1 according to the present embodiment will be described with reference to FIGS. 3A to 3C.

In the optical device 1, the injection and discharge of the liquid 7 into and from the gap 40 are repeatedly performed. Each of the injection and the discharge may be performed, for example, at a timing when an instruction from the user is received, or at a timing indicated by a preset schedule.

First, the injection of the liquid 7 will be described with reference to FIG. 3A. FIG. 3A is a cross-sectional view showing how the liquid 7 is injected into the gap 40 of the light distribution device 2 of the optical device 1 according to the present embodiment.

{Circle around (1)} First, the liquid sending device 5 sends out the liquid 7 stored in the container 3 to the pipe 4. The liquid 7 flowing through the pipe 4 is injected into the gap 40 from the opening 54. In the present embodiment, since the opening 54 is provided in the lower end surface of the light distribution device 2, the liquid 7 fills the inside of the gap 40 from below as indicated by the solid arrow in FIG. 3A. I do. At this time, as indicated by the dashed arrow in FIG. 3A, the air 8 contained in the gap 40 is discharged to the outside through the air hole 55 so as to be pushed out by the liquid 7. When the liquid 7 fills the entire gap 40, the liquid feeding device 5 stops injecting the liquid 7.

At this time, the liquid feeding device 5 maintains the pressure on the liquid 7 so as to balance the weight of the liquid 7. Thereby, the backflow of the liquid 7, that is, the discharge of the liquid 7 from the gap 40 can be suppressed. The pipe 4 may be provided with an openable / closable valve. The valve may be closed when the liquid feeding device 5 or the control device (not shown) stops the injection of the liquid 7.

The liquid supply device 5 may stop the injection of the liquid 7 before filling the entire gap 40 with the liquid 7. In this case, different optical characteristics can be realized between the upper side and the lower side of the light distribution device 2. That is, by adjusting the height of the liquid surface of the liquid 7, different optical characteristics can be realized for each region of the light distribution device 2.

Next, discharge of the liquid 7 will be described with reference to FIG. 3B. FIG. 3B is a cross-sectional view showing a state where the liquid 7 is discharged from the gap 40 of the light distribution device 2 of the optical device 1 according to the present embodiment.

液 The liquid supply device 5 stops the pressure applied to the liquid 7. Alternatively, when a valve is provided in the pipe 4, the valve is opened. As a result, as shown by the solid arrow in FIG. 3B, the liquid 7 is discharged from the opening 54 by its own weight. The discharged liquid 7 is stored in the container 3 through the pipe 4. As shown by the dashed arrow in FIG. 3B, the air 8 is introduced into the gap 40 after the liquid 7 is discharged via the air hole 55.

The liquid sending device 5 may be capable of flowing the liquid 7 in a direction opposite to the direction in which the liquid 7 is injected. As a result, the liquid 7 can be discharged more quickly.

FIG. 3C is a cross-sectional view showing a state where the liquid 7 is completely discharged from the gap 40 of the light distribution device 2 of the optical device 1 according to the present embodiment. After the liquid 7 has been completely drained, the gap 40 is filled with air 8.

The air 8 is, for example, air located around the light distribution device 2, but may be gas prepared in advance in a container or the like. For example, a container containing dry air, nitrogen, or an inert gas may be connected to the air hole 55. That is, the optical device 1 may include a container that stores a gas such as an inert gas. The inert gas is, for example, argon, but is not particularly limited.

As described above, in the optical device 1 according to the present embodiment, the injection and discharge of the liquid 7 into and from the gap 40 of the light distribution device 2 can be adjusted. In the present embodiment, the optical state of the portion of the light distribution device 2 filled with the liquid 7 becomes transparent in plan view. The optical state of the portion of the light distribution device 2 from which the liquid 7 is discharged, that is, the portion where the liquid 7 does not exist is a light distribution state. The specific optical state will be described below.

[Optical state]
Subsequently, an optical state of the light distribution device 2 according to the present embodiment will be described with reference to FIGS. 4A and 4B. Here, a case where both the refractive index n1 of the uneven structure layer 30 and the refractive index n2 of the liquid 7 are 1.5 will be described.

<Transparent state>
FIG. 4A is a cross-sectional view illustrating a transparent state of the light distribution device 2 of the optical device 1 according to the present embodiment. In FIG. 4A, the path of the light L obliquely incident on the light distribution device 2 is indicated by an arrow. When the light distribution device 2 is used for a window, the light L corresponds to sunlight that enters obliquely downward from indoors to indoors. The same applies to FIG. 4B.

ＡAs shown in FIG. 4A, the gap 40 of the light distribution device 2 is filled with the liquid 7. Since the difference between the refractive index n1 of the concavo-convex structure layer 30 and the refractive index n2 of the liquid 7 is 0, the light L does not receive an optical action on any of the side surfaces 32 and 33 of the convex portion 31. That is, the light L incident on the first substrate 10 from outside travels straight from the liquid 7 to the concave-convex structure layer 30 without bending the traveling direction, and is emitted from the second substrate 20. That is, the light L is not totally reflected by the side surface 33 of the convex portion 31.

As described above, the optical state of the light distribution device 2 is a transparent state in which the incident light is transmitted substantially without changing the traveling direction. Since the optical state of the light distribution device 2 is a transparent state, for example, when a person who is indoors views the outside via the light distribution device 2, the outdoor scene can be clearly seen.

Although not shown in FIG. 4A for the sake of simplicity, the light L is actually refracted according to the refractive index difference when the medium passing therethrough changes. Specifically, when the light L enters the first substrate 10, exits from the second substrate 20, passes through the interface between the first substrate 10 and the liquid 7, the light L When passing through the interface with the glass substrate 21 and through the respective interfaces of the film substrate 22, the adhesive layer 23, and the glass substrate 21 in the second substrate 20, the light is refracted according to the refractive index difference. The same applies to FIGS. 4B, 5A, and 5B described later.

<Light distribution state>
FIG. 4B is a cross-sectional view showing a light distribution state of light distribution device 2 of optical device 1 according to the present embodiment.

As shown in FIG. 4B, the liquid 7 is discharged from the gap 40 of the light distribution device 2, and the air 8 is introduced instead. The refractive index of the air 8 is about 1. Since the difference between the refractive index n1 of the concavo-convex structure layer 30 and the refractive index of the air 8 is about 0.5, the light L is subjected to an optical action when entering the side surfaces 32 and 33 of the convex portion 31. Specifically, the light L incident on the first substrate 10 from outside is refracted by the side surface 32 of the convex portion 31 (not shown), and then totally reflected by the side surface 33 as shown in FIG. 4B. Thus, the light L is emitted from the second substrate 20 obliquely upward.

Thus, the light distribution device 2 is in a light distribution state in which incident light is transmitted while bending its traveling direction. When the light distribution device 2 is used for a window, sunlight traveling obliquely downward can be bounced up by total reflection and emitted obliquely upward, so that the indoor ceiling can be illuminated brightly. . Thereby, the light distribution device 2 can assist the lighting function, so that it contributes to power saving of indoor lighting equipment and the like, and energy saving can be realized.

When the liquid 7 is filled only in a part of the gap 40, the portion filled with the liquid 7 becomes transparent as shown in FIG. 4A, and the liquid 7 is not filled. The portion enters a light distribution state as shown in FIG. 4B. Specifically, the height of the liquid surface of the liquid 7 in the gap portion 40 becomes a boundary between the transparent state and the light distribution state. For example, the height of the liquid surface of the liquid 7 in the gap portion 40 is adjusted by adjusting the amount of the liquid 7 injected into the gap portion 40 and the amount of discharge of the liquid 7 by the liquid sending device 5. Thereby, the ratio of the transparent state and the light distribution state in the plane of the light distribution device 2 can be adjusted.

[Effects, etc.]
As described above, the optical device 1 according to the present embodiment includes the light distribution device 2 that distributes incident light and the container 3. The light distribution device 2 includes a first substrate 10 having a light-transmitting property, a second substrate 20 having a light-transmitting property disposed to face the first substrate 10, and a first substrate 10 side of the second substrate 20. An uneven structure layer 30 having a light-transmitting property is provided, and a gap 40 provided between the uneven structure layer 30 and the first substrate 10 is provided. The container 3 contains the liquid 7 injected into the gap 40 and discharged from the gap 40.

By controlling the injection and discharge of the liquid 7 into and from the gap 40, the optical state of the light distribution device 2 can be adjusted. In the light distribution state, the liquid 7 is discharged from the gap 40, and the difference in the refractive index between the protrusion 31 and the gap 40 (that is, the air 8) increases. For this reason, the amount of light totally reflected by the side surface 33 of the convex portion 31 increases. For example, when the light distribution device 2 is installed in a window, the amount of light that illuminates the indoor ceiling (that is, the distributed light) increases. As described above, according to the optical device 1 according to the present embodiment, when used for a window, light can be efficiently introduced indoors.

絶対 Also, for example, when the refractive index of the uneven structure layer 30 is n1 and the refractive index of the liquid 7 is n2, the absolute value of n1−n2 is 0.01 or less.

Thereby, when the liquid 7 is injected into the gap portion 40, the convex portion 31 is covered with the liquid 7. Since the absolute value of n1−n2 is 0.01 or less, light passes through the interface between the convex portion 31 and the liquid 7 without receiving an optical effect. Thus, the optical state of the light distribution device 2 can be made transparent.

凹凸 Further, for example, the uneven structure layer 30 has a plurality of convex portions 31. The height of each of the plurality of protrusions 31 is 100 μm or more. The aspect ratio of each of the plurality of protrusions 31 is 2 or less. The interval between two adjacent protrusions 31 is not less than 10 μm and not more than 40 μm.

This makes it possible to smoothly inject and discharge the liquid 7 while maintaining a high light distribution rate. Specifically, the incorporation of bubbles during the injection of the liquid 7 and the retention of the liquid 7 during the discharge of the liquid 7 can be suppressed, so that the in-plane uniformity of the optical state of the light distribution device 2 is improved. be able to.

接触 Also, for example, the contact angle of the surface of the uneven structure layer 30 with the liquid 7 is 40 ° or more and 120 ° or less.

Thereby, the incorporation of bubbles at the time of injecting the liquid 7 and the remaining of the liquid 7 at the time of discharging the liquid 7 can be suppressed, so that the in-plane uniformity of the optical state of the light distribution device 2 can be improved. it can.

Further, for example, the surface tension of the liquid 7 is not less than 20 mN / m and not more than 76 mN / m.

光学 Further, for example, the optical device 1 further includes a liquid sending device 5 that performs at least one of injecting the liquid 7 into the gap 40 and discharging the liquid 7 from the gap 40.

(4) As a result, the liquid 7 can be quickly injected into and discharged from the gap 40, and thus the optical state of the light distribution device 2 can be smoothly switched.

For example, the optical device 1 further includes a flow rate sensor 6 that measures the flow rate of the liquid 7 flowing between the container 3 and the gap 40. The liquid feeding device 5 adjusts at least one of the injection amount and the discharge amount of the liquid 7 based on the flow rate measured by the flow sensor 6.

This allows the liquid 7 to be injected and discharged into the gap 40 with high accuracy. For example, leakage of the liquid 7 due to excessive injection of the liquid 7 and damage to the light distribution device 2 can be suppressed.

(Modification)
Hereinafter, modified examples of the optical device according to the above embodiment will be described.

[Modification 1]
In the above embodiment, the example in which the uneven structure layer 30 is provided on the indoor side has been described, but the uneven structure layer 30 may be provided on the outdoor side. Hereinafter, differences from the above-described embodiment will be mainly described, and description of common points will be omitted or simplified.

FIGS. 5A and 5B are cross-sectional views showing the transparent state and the light distribution state of the light distribution device 102 of the optical device according to the first modification, respectively. Although not shown in FIGS. 5A and 5B, the optical device according to the present modification includes a container 3, a pipe 4, a liquid feeding device 5, and a flow sensor 6, as in the above-described embodiment. The present modified example is different from the above-described embodiment in that the optical apparatus includes a light distribution device 102 instead of the light distribution device 2.

5A and 5B, the light distribution device 102 includes a first substrate 120, a second substrate 110, an uneven structure layer 30, a gap 40, and a sealing member 50. In this modification, the second substrate 110 provided with the uneven structure layer 30 is on the outdoor side, and the first substrate 120 is on the indoor side.

The second substrate 110 is, for example, the same as the first substrate 10. The first substrate 120 is, for example, the same as the second substrate 20. As in the above embodiment, the uneven structure layer 30 is provided on the first substrate 120 side of the second substrate 110. The gap 40 is provided between the uneven structure layer 30 and the first substrate 120.

As shown in FIG. 5A, when the liquid 7 is injected into the gap 40, the difference in the refractive index between the uneven structure layer 30 and the liquid 7 becomes substantially zero, so that the light enters the second substrate 110 from outside. The light L travels straight as it is without receiving an optical action at the interface between the convex portion 31 and the liquid 7. As described above, in a state where the liquid 7 is injected into the gap 40, the optical state of the light distribution device 102 becomes a transparent state.

(5) As shown in FIG. 5B, when the liquid 7 is discharged from the gap 40, the difference in the refractive index between the projection 31 and the air 8 increases. As a result, the light L incident on the second substrate 110 from outside is totally reflected by the side surface 33 of the convex portion 31 and emitted from the first substrate 120. As described above, in a state where the liquid 7 is discharged from the gap 40, the optical state of the light distribution device 102 becomes a light distribution state.

As described above, the light distribution state can be realized regardless of whether the uneven structure layer 30 is provided on the outdoor side or the indoor side.

[Modification 2]
In the above-described embodiment, an example in which the opening 54 and the air hole 55 are provided in the sealing member 50 has been described, but at least one of the opening 54 and the air hole 55 is provided in the first substrate 10 or the second substrate 20. It may be. Hereinafter, differences from the above-described embodiment will be mainly described, and description of common points will be omitted or simplified.

FIG. 6 is a cross-sectional view of the light distribution device 202 of the optical device according to the second modification. Although not shown in FIG. 6, the optical device according to the present modification includes a container 3, a liquid sending device 5, and a flow sensor 6, similarly to the above embodiment. This modification is different from the above-described embodiment in that the optical apparatus includes a light distribution device 202 instead of the light distribution device 2.

As shown in FIG. 6, the light distribution device 202 includes a first substrate 220, a second substrate 110, an uneven structure layer 30, a gap 40, a sealing member 250, a fastener 260, and a heat shield. A seat 270 and

connection members

204 and 208 are provided. The second substrate 110, the uneven structure layer 30, and the gap 40 are the same as those in the first embodiment or the first modification.

The first substrate 220 is different from the first substrate 120 in that an opening 254 and an air hole 255 are provided. The sealing member 250 is different from the sealing member 50 in that the opening 54 and the air hole 55 are not provided.

The opening 254 functions as an inlet and an outlet for the liquid 7 (not shown in FIG. 6), like the opening 54 according to the embodiment. The opening 254 is provided, for example, near the sealing member 50 below the first substrate 220. A plurality of openings 254 may be provided in the first substrate 220.

接続 As shown in FIG. 6, the connection member 204 is attached to the opening 254. The connection member 204 is a member that connects the pipe 4 and the opening 254. The connection member 204 is formed using, for example, a resin material or a metal material. The connection member 204 detachably supports the end of the pipe 4. The connection member 204 is, specifically, a female attachment having a through hole 204a. By inserting the end of the pipe 4 into the through hole 204a, the connection member 204 supports the end of the pipe 4. The connection member 204 has a structure that suppresses leakage of the liquid 7. For example, the connection member 204 may be provided with an O-ring or the like in the through hole 204a. When the end of the pipe 4 is inserted into the through hole 204a, leakage of the liquid 7 can be suppressed. At least one of the end of the pipe 4 and the connection member 204 may be provided with an operation button or lever for attaching and detaching the end of the pipe 4. Note that the connection member 204 may be a male attachment. In the example shown in FIG. 6, the connection member 204 is provided so as to penetrate a part of the stopper 260.

The air hole 255 functions as an air inlet and an air outlet for the air 8 (not shown in FIG. 6), like the air hole 55 according to the embodiment. The air hole 255 is provided, for example, near the sealing member 50 above the first substrate 220. A plurality of air holes 255 may be provided in the first substrate 220.

接続 As shown in FIG. 6, a connection member 208 is attached to the air hole 255. The connection member 208 is a member that connects the pipe 207 and the air hole 255. The connection member 208 is formed using, for example, a resin material or a metal material. The connection member 208 detachably supports the end of the pipe 207. The connection member 208 is, specifically, a female attachment having a through hole 208a. When the end of the pipe 207 is inserted into the through hole 208a, the connection member 208 supports the end of the pipe 207. At least one of the end of the pipe 207 and the connection member 208 may be provided with an operation button or lever for attaching and detaching the end of the pipe 207. Note that the connection member 208 may be a male attachment. In the example shown in FIG. 6, the connection member 208 is provided so as to penetrate a part of the stopper 260.

The pipe 207 is a pipe for passing the air 8. The other end of the pipe 207 (the end on the side not connected to the connection member 208) is open, for example, indoors or outdoors, but may be connected to a nitrogen gas supply source or the like. The pipe 207 is, for example, a hose formed using a resin material, but is not limited thereto. Note that the pipe 4 and the pipe 207 may be formed using the same material.

The stopper 260 sandwiches the first substrate 220, the second substrate 110, and the sealing member 50. The stopper 260 is, for example, an annular member provided along the end of the light distribution device 202. By providing the stopper 260, damage to the end of the light distribution device 202 can be suppressed.

熱 The heat shield sheet 270 is a heat shield sheet having a light transmitting property. The heat shielding sheet 270 is formed using, for example, a resin material having low thermal conductivity. In the present modification, the heat shield sheet 270 is provided on the main surface of the first substrate 220 on the side opposite to the gap 40. By providing the heat shield sheet 270, heat transfer from outdoors to indoors or vice versa can be suppressed. In addition, deformation of the uneven structure layer 30 due to thermal expansion and the like can be suppressed. In the example shown in FIG. 6, the end of the heat shield sheet 270 is covered with the stopper 260. Thereby, detachment of the heat shield sheet 270 can be suppressed.

In this modification, the example in which the opening 254 and the air hole 255 are provided in the first substrate 220 on the indoor side is shown, but the present invention is not limited to this. At least one of the opening 254 and the air hole 255 may be provided in the second substrate 110 on the outdoor side.

(Other)
As described above, the optical device according to the present invention has been described based on the above-described embodiment and its modifications, but the present invention is not limited to the above-described embodiment.

For example, the optical device 1 does not need to include the liquid feeding device 5. The liquid 7 may be moved using the weight of the liquid 7. For example, the optical device 1 may include a drive mechanism that changes the height of the container 3. By raising the container 3 to a position higher than the gap 40, the liquid 7 can be injected from the container 3 into the gap 40. By lowering the container 3 to a position lower than the gap 40, the liquid 7 can be discharged from the gap 40 to the container 3.

液体 Further, for example, the liquid 7 may not have translucency. The liquid 7 may have a light scattering property or a light shielding property. For example, the liquid 7 may contain colored particles such as black, or may contain light scattering particles. Thereby, the light distribution device 2 can realize a scattering state or a light blocking state instead of the transparent state. Alternatively, the liquid 7 may contain heat reflective particles or heat absorbing particles. The container 3 may be provided with an opening for putting the liquid 7 in the container 3, and the liquid 7 may be replaceable. Alternatively, the container 3 may be detachable from the pipe 4.

絶対 Also, for example, when the refractive index of the uneven structure layer 30 is n1 and the refractive index of the liquid 7 is n2, the absolute value of n1−n2 may be larger than 0.01.

Further, for example, the capacity of the container 3 may be smaller than the capacity of the gap 40. For example, the sum of the capacity of the container 3 and the capacity of the pipe 4 may be equal to or larger than the capacity of the gap 40. Thereby, all of the liquid 7 injected into the gap 40 can be discharged to the container 3 and the pipe 4.

Alternatively, the liquid 7 may not be completely discharged from the gap 40. That is, the liquid 7 may remain in a part of the gap 40. When the light distribution device 2 is used for a window, the upper part of the light distribution device 2 than the lower part is effectively used to take in light indoors. At this time, when the light under the light distribution device 2 is distributed, the light is likely to enter the eyes of a person who is indoors, which may cause glare. For this reason, the lower part of the light distribution device 2 is in a state where the gap portion 40 is always filled with the liquid 7, and the optical state may be a transparent state. For example, in the case of the light distribution device 2 having a height of 2 m, the liquid level of the liquid 7 in the gap 40 is adjusted in the upper 1 m range, and the liquid 7 is always filled in the lower 1 m range. Good. Further, the uneven structure layer 30 may not be provided below the light distribution device 2. That is, the concavo-convex structure layer 30 may not be provided on the entire surface of the second substrate 20 and may be provided only on a part of the region.

Further, for example, the inlet and the outlet of the liquid 7 to the gap 40 may be different. For example, the sealing member 50 of the light distribution device 2 may have a plurality of openings 54. The optical device 1 may include a plurality of pipes 4 connected to each of the plurality of openings 54. Thereby, by separating the inlet and the outlet of the liquid 7, the flow of the liquid 7 can be easily controlled, and the optical state of the light distribution device 2 can be smoothly switched. Note that each of the plurality of openings 54 may be an inlet and an outlet.

開口 The plurality of openings 54 are respectively provided in the lower end surface of the light distribution device 2, for example. Alternatively, at least one of the plurality of openings 54 may be provided on an upper end surface or a side end surface of the light distribution device 2. Similarly, a plurality of air holes 55 may be provided.

循環 Further, a circulation path of the liquid 7 may be formed. For example, the liquid 7 may flow sequentially through the container 3, one pipe 4, one opening 54, the gap 40 of the light distribution device 2, another opening 54, and another pipe 4.

The optical device 1 may include a plurality of containers 3. Different types of liquids 7 are stored in each of the plurality of containers 3. Thereby, the optical state of the light distribution device 2 can be changed to not only two states of the transparent state and the light distribution state but also three or more states including, for example, a scattering state or a light shielding state.

For example, the light incident on the light distribution device 2 is not limited to natural light such as sunlight, and may be light emitted from a light emitting device such as a lighting device.

Further, for example, the light distribution device 2 is not limited to being installed in a window of a building, but may be installed in a window of a car, for example. Further, the light distribution device 2 can be used for a light distribution control member such as a light-transmitting cover of a lighting fixture, for example. Alternatively, the light distribution device 2 can also be used as a blindfold member using light scattering at the interface of the uneven structure layer 30.

In addition, a form obtained by applying various modifications that can be conceived by those skilled in the art to each embodiment, and a combination of components and functions in each embodiment without departing from the spirit of the present invention are realized. Embodiments are also included in the present invention.

Reference Signs List 1

optical device

2, 102, 202 light distribution device 3 container 5 liquid sending device 6 flow sensor 7

liquid

10, 120, 220

first substrate

20, 110 second substrate 30 concave / convex structure layer 31 convex portion 40 gap portion

Claims

A light distribution device that distributes incident light;
And a container,
The light distribution device,
A first substrate having translucency,
A second substrate having a light-transmitting property arranged opposite to the first substrate,
An uneven structure layer having a light-transmitting property, which is arranged on the first substrate side of the second substrate,
Comprising a gap provided between the uneven structure layer and the first substrate,
The optical device, wherein the container contains a liquid that is injected into the gap and that is discharged from the gap.
2. The optical device according to claim 1, wherein an absolute value of n1−n2 is 0.01 or less, where n1 is a refractive index of the uneven structure layer and n2 is a refractive index of the liquid.
The uneven structure layer has a plurality of convex portions,
The height of each of the plurality of protrusions is 100 μm or more,
The aspect ratio of each of the plurality of protrusions is 2 or less,
The optical device according to claim 1, wherein an interval between two adjacent protrusions is 10 μm or more and 40 μm or less.
The optical device according to any one of claims 1 to 3, wherein a contact angle of the surface of the uneven structure layer with the liquid is 40 ° or more and 120 ° or less.
The optical device according to any one of claims 1 to 4, wherein a surface tension of the liquid is not less than 20 mN / m and not more than 76 mN / m.
The optical device according to any one of claims 1 to 5, further comprising a liquid sending device that performs at least one of injecting the liquid into the gap and discharging the liquid from the gap.
Further, a flow sensor for measuring the flow rate of the liquid flowing between the container and the gap portion,
The optical device according to claim 6, wherein the liquid feeding device adjusts at least one of an injection amount and a discharge amount of the liquid based on a flow rate measured by the flow rate sensor.