JP2020068183A - Optical device - Google Patents

Abstract

To provide an optical device that can efficiently introduce light into a house when used for a window.SOLUTION: An optical device 1 comprises a light distribution device 2 for distributing incident light, and a container 3. The light distribution device 2 comprises a first board 10 having translucency, a second board 20 arranged opposite to the first board 10 and having translucency, a first uneven structure layer 30 comprising a plurality of first convex parts 31 provided side by side in one direction, a gap part 40 provided between the first board 10 and the first uneven structure layer 30, a third board 60 having translucency, and a second uneven structure layer 70 comprising a plurality of second convex parts 71 provided side by side in one direction. The container 3 houses liquid 8 to be injected into the gap part 40 and discharged from the gap part 40.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an optical device.

  In Patent Document 1, a refractive index adjusting layer disposed between a first electrode and a second electrode and capable of changing a transparent state and a state of distributing incident light, a first electrode and a refractive index adjusting layer. And an uneven layer having a plurality of convex portions protruding toward the second electrode, the optical device being disclosed.

International Publication No. 2016/185692

  In the above conventional optical device, since the difference in refractive index between the convex portion and the refractive index adjusting layer is small, the amount of light that can be totally reflected is small. Therefore, even if the above conventional optical device is used for a window, it is not possible to efficiently take in light indoors.

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

  In order to achieve the above object, an optical device according to an aspect of the present invention includes a light distribution device that distributes incident light and a container, and the light distribution device includes a first substrate having a light-transmitting property. A second substrate having a light-transmitting property, which is arranged so as to face the first substrate, and a main face which is a main face of the second substrate and which faces the first substrate. A first concavo-convex structure layer having a plurality of first convex portions arranged side by side in one direction, a gap provided between the first substrate and the first concavo-convex structure layer, and A third light-transmitting member that is arranged to face a second main surface that is the main surface of the first substrate or the second substrate and that is the main surface on the side opposite to the side where the gap is provided. A substrate, a third main surface of the third substrate, which is a main surface facing the second main surface, and a second main surface, And a second concavo-convex structure layer having a second protrusion plurality of which are arranged in the direction, the container is injected into the gap, and containing the liquid to be discharged from the gap portion.

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

FIG. 1 is a schematic diagram showing the configuration of the optical device according to the embodiment. FIG. 2 is a cross-sectional view of a light distribution device included in the optical device according to the embodiment. FIG. 3 is a cross-sectional view of the first protrusion of the first concavo-convex structure layer included in the light distribution device according to the embodiment. FIG. 4 is a cross-sectional view of the second convex portion of the second uneven structure layer included in the light distribution device according to the embodiment. FIG. 5 is a cross-sectional view showing a light distribution state (first light distribution state) for low-angle incidence of the light distribution device according to the embodiment. FIG. 6 is a sectional view showing a light distribution state (second light distribution state) for high-angle incidence of the light distribution device according to the embodiment. FIG. 7 is a schematic diagram showing the configuration of the optical device according to the modification of the embodiment.

  Hereinafter, optical devices according to embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that each of the embodiments described below shows a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangements and connection forms of components, steps, order of steps, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. Therefore, among the constituents in the following embodiments, constituents not described in the independent claims are described as arbitrary constituents.

  In addition, each drawing is a schematic view, and is not necessarily strictly illustrated. Therefore, for example, the scales and the like in the drawings do not necessarily match. In addition, in each of the drawings, substantially the same configurations are denoted by the same reference numerals, and overlapping description will be omitted or simplified.

  In addition, in the present specification, a term indicating a relationship between elements such as parallel or vertical, a term indicating a shape of an element such as a triangle or a trapezoid, and a numerical range are not expressions expressing only a strict meaning. , Is a phrase meaning to include a substantially equivalent range, for example, a difference of about several percent.

  In addition, in the present specification and the drawings, the X axis, the Y axis, and the Z axis indicate the three axes of the three-dimensional orthogonal coordinate system. In each of the embodiments, 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. The positive direction of the Z-axis is 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 surfaces of the first substrate and the second substrate, and the “plan view” is It refers to the view seen from the 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. 1 and 2. FIG. 1 is a schematic diagram showing the configuration of the optical device 1 according to the present embodiment. FIG. 2 is a cross-sectional view of the light distribution device 2 included in the optical device 1 according to this 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 pump 5, a control unit 6, and valves 7a and 7b. Note that, in FIG. 1, only the light distribution device 2 is illustrated in a plan view, and the container 3, the pipe 4, the pump 5, the control unit 6, and the valves 7a and 7b schematically show the connection relationship with each other. ing.

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

  In the present embodiment, the “light distribution” is to bend the traveling direction of the incident light incident on the light distribution device 2 in a specific direction and emit the light. For example, when the light distribution device 2 is vertically arranged along the vertical direction, when the light traveling obliquely downward is transmitted, the light distribution device 2 totally reflects the light and emits the light obliquely upward. . The specific optical action of the light distribution device 2 will be described later.

  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, for example, by being attached to an existing transparent base material such as a window glass via an adhesive layer. Alternatively, the light distribution device 2 may be used as the window itself of the building. The light distribution device 2 is arranged in the window of the building such that the second substrate 20 shown in FIG. 2 is on the indoor side and the first substrate 10 is on the outdoor side, for example.

  The light distribution device 2 includes a first substrate 10, a second substrate 20, a first uneven structure layer 30, a gap portion 40, a first sealing member 50, a third substrate 60, and a second uneven structure layer. 70 and a second sealing member 90. Details of each component will be described later.

  In the present embodiment, as shown in FIG. 2, the optical device 1 includes the liquid 8 that can fill the gap portion 40. The optical device 1 controls the injection of the liquid 8 into the gap 40 and the discharge of the liquid 8 from the gap 40 to refract the surface of the first concavo-convex structure layer 30 and the medium in contact with the surface. You can change the rate difference.

  Specifically, when the liquid 8 is injected into the gap 40, the liquid 8 becomes a medium that contacts the surface of the first concavo-convex structure layer 30. For example, the difference in refractive index between the liquid 8 and the first concavo-convex structure layer 30 becomes substantially equal, and the optical state between the first substrate 10 and the second substrate 20 of the light distribution device 2 becomes transparent. When the liquid 8 is discharged from the gap 40, the gas 9a introduced into the gap 40 instead of the discharged liquid 8 becomes a medium that comes into contact with the surface of the first concavo-convex structure layer 30. The refractive index difference between the gas 9a and the first concavo-convex structure layer 30 becomes large, and the optical state between the first substrate 10 and the second substrate 20 becomes a light distribution state.

  The liquid 8 is a liquid that is injected into the gap 40 and discharged from the gap 40. That is, the liquid 8 is injected into the gap 40 at the first timing and then discharged from the gap 40 at the second timing. The discharged liquid 8 is stored in the container 3. Further, the discharged liquid 8 is injected into the gap 40 at the third timing. That is, the liquid 8 is repeatedly injected into and discharged from the gap 40.

  The volume of the liquid 8 is equal to the volume of the gap 40, for example. Thereby, the gap portion 40 can be completely filled with the liquid 8. The volume of the liquid 8 may be smaller or larger than the volume of the gap 40.

  In the present embodiment, the refractive index of the liquid 8 is equal to the refractive index of the first concavo-convex structure layer 30. The term "equal" as used herein includes not only a perfect match but also a substantially equal meaning. That is, the refractive index of the liquid 8 and the refractive index of the first concavo-convex structure layer 30 may have a slight difference. For example, when the refractive index of the first concavo-convex structure layer 30 is n1 and the refractive index of the liquid 8 is n2, the absolute value of n1-n2 may be 0.01 or less.

  The liquid 8 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 8 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, sugar water, or the like. Alternatively, the liquid 8 may be an aqueous solution containing nanoparticles having a high refractive index or an organic material.

  The liquid 8 has a surface tension of 20 mN / m or more and 76 mN / m or less. Specifically, the liquid 8 has a surface tension of 20 mN / m or more and 76 mN / m or less in the range of 0 ° C. or higher and 40 ° C. or lower. When the surface tension is 20 mN / m or more, the liquid 8 can be easily injected and discharged. For example, it is possible to suppress the liquid 8 from remaining at the time of discharging, and suppress the mixing of bubbles into the liquid 8 at the time of injecting. Thereby, the uniformity of the optical state within the surface of the light distribution device 2 can be improved.

  The gas 9a introduced instead when the liquid 8 is discharged 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 52 through which the gas 9a flows in and out. 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.

  The container 3 is a container for containing the liquid 8. 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 the opening 51 provided in the first sealing member 50. The container 3 may be directly connected to the opening 51 of the light distribution device 2. That is, the optical device 1 may not include the pipe 4.

  The capacity of the container 3 is, for example, greater than or equal to the capacity of the gap 40. Accordingly, the container 3 can completely discharge the liquid 8 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 of, for example, a material that does not react with the liquid 8.

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

  The pump 5 is an example of a liquid feeding unit that performs at least one of injecting the liquid 8 into the gap 40 and discharging the liquid 8 from the gap 40. In the present embodiment, the pump 5 both injects and discharges the liquid 8. The pump 5 can adjust the flow rate and the flowing direction of the liquid 8 flowing through the pipe 4, for example.

  Either the injection or the discharge of the liquid 8 may be performed by utilizing the weight of the liquid 8. Specifically, when the container 3 is provided at a position higher than the gap 40, the liquid 8 can be easily injected from the container 3 into the gap 40 by the weight of the liquid 8 only by opening the valve 7a. Be seen. When the container 3 is provided at a position lower than the gap 40, the liquid 8 is easily discharged from the gap 40 to the container 3 by the weight of the liquid 8. As described above, the pump 5 does not need to perform one of the injection and the discharge of the liquid 8 in the gap 40. The pump 5 is provided in the pipe 4, for example, but may be provided in the container 3.

  The control unit 6 controls the pump 5. Specifically, the control unit 6 controls the pump 5 based on at least one of an instruction from the user, the sun altitude, date and time, and weather. The control unit 6 controls the pump 5 to adjust the injection timing and the discharge timing of the liquid 8 and the injection amount and the discharge amount. For example, the control unit 6 controls the pump 5 according to the sun altitude to adjust the injection amount and the discharge amount of the liquid 8 into the gap 40.

  The sun altitude is determined based on the latitude and longitude of the point where the optical device 1 is installed, and the date and time. When the optical device 1 is used for a window of a building, the latitude and the longitude are usually unchanged, so the solar altitude is determined based on the date and time. Therefore, in the present embodiment, the control unit 6 controls the pump 5 based on the date and time information indicating the current time and date. For example, the control unit 6 has a clock function that acquires date and time information. Alternatively, the control unit 6 may have a communication IF that acquires date and time information by communicating with an external device.

  The control unit 6 is realized by, for example, a microcontroller. The control unit 6 is realized by, for example, a non-volatile memory in which a program is stored, a volatile memory that is a temporary storage area for executing the program, an input / output port, a processor that executes the program, and the like. The function of the control unit 6 is realized by software executed by the processor. Alternatively, the function of the control unit 6 may be realized by hardware such as an electronic circuit including a plurality of circuit elements.

  The valve 7 a is connected to the pipe 4 and controls the flow of the liquid 8 to the gap 40. The opening and closing of the valve 7a is controlled by the control unit 6, for example. With the valve 7a opened, the liquid 8 is injected from the container 3 into the gap 40, and the liquid 8 is discharged from the gap 40 into the container 3. When the valve 7 a is closed, the leakage of the liquid 8 injected into the gap 40 and the infiltration of the liquid 8 from the container 3 into the gap 40 can be suppressed.

  The valve 7b controls the flow of the gas 9a with respect to the gap 40. The valve 7b is connected to, for example, a pipe (not shown in FIG. 2) connected to the air hole 52 shown in FIG. 2, and the control unit 6 controls opening / closing. The valve 7b is opened when the liquid 8 is injected and discharged.

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

[First Substrate, Second Substrate, and Third Substrate]
Each of the first substrate 10, the second substrate 20, and the third substrate 60 is a light-transmitting base material. As the first substrate 10, the second substrate 20, and the third substrate 60, for example, glass substrates or resin substrates can be used.

  Examples of the material for the glass substrate include soda glass, alkali-free 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) or 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 breakage is small. In this embodiment, each of the first substrate 10, the second substrate 20, and the third substrate 60 is a transparent resin substrate made of PET resin.

  The first substrate 10, the second substrate 20, and the third substrate 60 are, for example, rigid substrates, but may be flexible substrates. The thickness of each of the first substrate 10, the second substrate 20, and the third substrate 60 is, for example, 1 μm or more and 1000 μm or less, but is not limited to this. The plan view shape of the first substrate 10 is, for example, a rectangle or a square, but is not limited to this, and may be a polygon other than a rectangle or a circle.

  In the present embodiment, as shown in FIG. 2, first substrate 10 has main surface 11. The main surface 11 is an example of a second main surface that is a main surface on the side opposite to the side on which the gap portion 40 is provided.

  In the present embodiment, the first substrate 10 is composed of a single substrate, but is not limited to this. The first substrate 10 may have a laminated structure of a plurality of substrates. For example, the first substrate 10 may include two transparent substrates arranged to face each other and a transparent adhesive layer that bonds the two transparent substrates. For example, one of the two transparent substrates, the second substrate 20, the first concavo-convex structure layer 30, the first device including the gap 40 and the first sealing member 50, the other of the two transparent substrates, and the third substrate. 60, the second uneven structure layer 70, and the second device including the second sealing member 90 may be separately manufactured, and then the first device and the second device may be bonded to each other via the adhesive layer.

  The second substrate 20 is arranged so as to face the first substrate 10. The second substrate 20 has a main surface 21. The main surface 21 is an example of a first main surface that is a main surface facing the first substrate 10. The 1st board | substrate 10 and the 2nd board | substrate 20 are arrange | positioned mutually parallel, and the space | interval is 1 mm, for example.

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

  The third substrate 60 is arranged so as to face the main surface 11. The third substrate 60 has a main surface 61. The main surface 61 is an example of a third main surface which is a main surface facing the main surface 11. The third substrate 60 and the first substrate 10 are arranged in parallel with each other. In the present embodiment, the second uneven structure layer 70 is in contact with the main surface 61. That is, the distance between the third substrate 60 and the first substrate 10 is equal to the thickness of the second uneven structure layer 70. The main surface 61 and the second concavo-convex structure layer 70 may be provided apart from each other without making contact with each other.

  In the present embodiment, the third substrate 60 and the first substrate 10 are adhered to each other by the second sealing member 90 provided in a frame shape along the outer peripheries of their ends. Between the third substrate 60 and the first substrate 10, a plurality of particulate spacers may be dispersed in the surface or a columnar structure may be formed in order to keep the distance constant. .

  Note that at least one of the first substrate 10, the second substrate 20, and the third substrate 60 may be provided with a highly rigid transparent base material that supports each substrate. For example, a pair of supporting glass substrates may be provided so as to sandwich the light distribution device 2. Each of the second substrate 20 and the third substrate 60 may be attached to the supporting glass substrate via a transparent adhesive layer. The thickness of the supporting glass substrate is, for example, 3 mm or more and 6 mm or less, but is not limited to this.

[First concavo-convex structure layer]
The first concavo-convex structure layer 30 is a finely-shaped layer arranged on the main surface 21 of the second substrate 20. As shown in FIG. 2, the first concavo-convex structure layer 30 has a plurality of first convex portions 31 arranged side by side in one direction.

  Specifically, the first concavo-convex structure layer 30 is a concavo-convex structure body including a plurality of first convex portions 31 having a micro-order size. In the example shown in FIG. 2, the plurality of first convex portions 31 are individually separated from each other, and are supported by the base layer at the root (the second substrate 20 side). That is, a flat surface is provided between two adjacent first convex portions 31. The base layer is, for example, a portion that remains as a residual film when the plurality of first convex portions 31 is molded. The plurality of first protrusions 31 may be connected to each other at their roots, and a flat surface may not be provided between two adjacent first protrusions 31. That is, the cross-sectional shape of the concave portion between the two adjacent first convex portions 31 may be V-shaped. For example, the first concavo-convex structure layer 30 is provided in contact with the main surface 21 without interposing another member such as an electrode layer. A transparent adhesive layer or the like may be provided between the first concavo-convex structure layer 30 and the second substrate 20.

  The first concavo-convex structure layer 30 refracts the light that is incident in a state where the liquid 8 is discharged from the gap 40 and is totally reflected by the side surface 71b of the second convex portion 71 of the second concavo-convex structure layer 70. It has a light distribution structure. The light distribution structure is composed of a plurality of first convex portions 31.

  The plurality of first protrusions 31 are arranged side by side in the Z-axis direction. The plurality of first protrusions 31 are long protrusions extending in a direction orthogonal to the arrangement direction (that is, the Z-axis direction). Specifically, the plurality of first convex portions 31 are formed in stripes extending in the X-axis direction while maintaining the cross-sectional shape of the cross section (YZ cross section) orthogonal to the X axis. For example, each of the plurality of first convex portions 31 is a trapezoidal column that is arranged laterally with respect to the second substrate 20. Note that the plurality of first convex portions 31 may extend meandering along the X-axis direction. For example, the plurality of first convex portions 31 may be formed in a wavy line stripe shape in a plan view.

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

  Note that the trapezoid or triangle also includes a trapezoid or triangle with rounded vertices. In addition, a trapezoid or a triangle may have a case in which each side is not perfectly straight, for example, is slightly bent with a displacement of about several% of the length of each side, or may include minute irregularities. included.

  FIG. 3 is a cross-sectional view of the first convex portion 31 of the first uneven structure layer 30 included in the light distribution device 2 according to this embodiment. Although FIG. 3 shows the YZ cross section, the cross section is not shaded.

  As shown in FIGS. 2 and 3, each of the plurality of first protrusions 31 has side surfaces 31a and 31b. The side surfaces 31a and 31b are surfaces that intersect in the Z-axis direction. At least one of the side surfaces 31a and 31b is an inclined surface that is inclined at a predetermined inclination angle with respect to the direction orthogonal to the main surface 21 (that is, the Y axis direction). The distance between the side surface 31a and the side surface 31b, that is, the width of the first convex portion 31 gradually decreases from the second substrate 20 toward the first substrate 10.

  The side surface 31a is an example of the first side surface, and for example, when the light distribution device 2 is arranged so that the Z axis is aligned in the vertical direction, among the plurality of side surfaces that form the first convex portion 31, the side surface 31a is vertically upward. It is the side of the side.

  The side surface 31b is an example of a first side surface, and, for example, when the light distribution device 2 is arranged so that the Z axis is aligned in the vertical direction, the side surface 31b is vertically downward from among the plurality of side surfaces forming the first convex portion 31. It is the side of the side. As shown in FIG. 3, the side surface 31b functions as a refraction surface that refracts the light L2 incident from below. The light L2 is, for example, light that is totally reflected by the second convex portion 71 of the second uneven structure layer 70 and travels upward.

Each inclination angle alpha ₂ of the inclination angle alpha ₁ and the side surface 31b of the side surface 31a, for example in the range of 20 ° or more than 35 °. In other words, the two base angles of the trapezoid or the triangle, which is the cross-sectional shape of the first convex portion 31, are each 55 ° or more and 70 ° or less. The inclination angle alpha ₂ of the inclination angle alpha ₁ and the side surface 31b of the side surface 31a, may be different from each other, it may be equal. That is, the cross-sectional shape of the first convex portion 31 may be an isosceles trapezoid or an isosceles triangle. The inclination angles α ₁ of the side surfaces 31a of the plurality of first convex portions 31 may be equal to or different from each other. The inclination angles α ₂ of the side surfaces 31b of each of the plurality of first convex portions 31 may be equal to or different from each other.

  The height of each of the plurality of first convex portions 31 is, for example, 100 μm or more. When the height is 100 μm or more, the side surfaces 31b and 31b that reflect light can be widely secured. Therefore, the amount of light to be distributed becomes large, so that the light distribution rate can be increased.

  Further, the aspect ratio of each of the plurality of first convex portions 31 is, for example, 2 or less. The aspect ratio is the ratio of the height to the width of the root of the first convex portion 31. When the aspect ratio is 2 or less, the physical strength of the first convex portion 31 can be increased. For example, it is possible to prevent the shape of the first convex portion 31 from changing due to the flow of the liquid 8 when the liquid 8 is injected and discharged.

  The interval between two adjacent first convex portions 31 is, for example, 10 μm or more and 40 μm or less. In addition, the said space | interval is the distance between the roots of two adjacent 1st convex parts 31. That is, the interval corresponds to the width of the flat surface of the concave portion between the two adjacent first convex portions 31. When the distance between the two adjacent first convex portions 31 is 10 μm or more, the liquid 8 injected into the gap portion 40 is unlikely to remain in the concave portion. Therefore, the liquid 8 can be quickly discharged. In addition, when the distance between the two adjacent first convex portions 31 is 40 μm or less, the in-plane density of the first convex portions 31 can be increased. Therefore, the amount of light to be distributed becomes large, so that the light distribution rate can be increased.

  The height of each of the plurality of first protrusions 31 may be 1 mm or more. That is, the plurality of first convex portions 31 may be convex portions having a millimeter order size. Even if the injected liquid 8 is not completely discharged and remains partially, a sufficiently large reflective surface can be secured as a whole.

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

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

  As the material of the first concavo-convex structure layer 30, for example, a resin material having a light-transmitting property such as acrylic resin, epoxy resin, or silicone resin can be used. The refractive index of the first concavo-convex structure layer 30 is, for example, in the range of 1.4 or more and 1.8 or less. In the present embodiment, the first concavo-convex 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 first concavo-convex structure layer 30 with the liquid 8 is, for example, 60 ° or more and 120 ° or less. The contact angle may be 90 ° or more and 120 ° or less. That is, the side surfaces 31 a and 31 b of the first convex portion 31 have liquid repellency (specifically, oil repellency or water repellency) or super liquid repellency with respect to the liquid 8. For example, the surface of the first concavo-convex structure layer 30 may be coated with fluorine. Alternatively, a fluorine-based functional group may be introduced in the molecular structure on the surface of the first uneven structure layer 30. A fluorine-based functional group may be introduced into the molecular structure of the liquid 8.

  Further, the surface of the first concavo-convex structure layer 30 may have lyophilicity (specifically, lipophilicity or hydrophilicity) or superhydrophilicity with respect to the liquid 8. For example, the contact angle of the surface of the first concavo-convex structure layer 30 with the liquid 8 may be less than 60 °. For example, the contact angle may be 40 ° or more.

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

  The liquid 8 is injected into the gap 40. The injected liquid 8 contacts and covers the surface of the first concavo-convex structure layer 30, specifically, the side surfaces 31 a and 31 b of the first convex portion 31. In the present embodiment, since the refractive index n2 of the liquid 8 is substantially equal to the refractive index n1 of the first concavo-convex structure layer 30, the refractive index difference between the liquid 8 and the first concavo-convex structure layer 30 is sufficiently small. Become. Thereby, the light passing through the gap 40 and the first concavo-convex structure layer 30 travels substantially straight without being subjected to optical effects such as reflection and refraction on the surface of the first concavo-convex structure layer 30.

  After the liquid 8 is discharged, the gap 40 is filled with the gas 9a, for example. When the liquid 8 is discharged from the gap 40, the difference in refractive index between the gap 40 (that is, the gas 9a) and the first uneven structure layer 30 becomes large. Thereby, the light passing through the gap 40 and the first concavo-convex structure layer 30 is totally reflected or refracted by the side surface 31 b of the first convex portion 31, and is emitted in a direction different from the incident direction.

  The difference in the optical state depending on the presence or absence of the liquid 8 in the gap 40 will be described in detail later.

[First sealing member]
The first sealing member 50 is an annular member for forming a space for sealing the liquid 8 between the first substrate 10 and the second substrate 20, that is, a gap 40. Specifically, the first sealing member 50 is provided along each end of the first substrate 10 and the second substrate 20. Since each of the first substrate 10 and the second substrate 20 has a rectangular shape in plan view, the first sealing member 50 is provided in a rectangular annular shape. That is, the first sealing member 50 is provided along each of the four sides of the first substrate 10 and the second substrate 20 in a plan view.

  The first sealing member 50 bonds the first substrate 10 and the second substrate 20 at the peripheral edge portion. The gap 40 is formed by this adhesion. The first sealing member 50 is a member that maintains the distance between the first substrate 10 and the second substrate 20.

  In the present embodiment, as shown in FIG. 2, the first sealing member 50 has an opening 51 and an air hole 52.

  The openings 51 are inlets and outlets for the liquid 8. The opening 51 is provided so as to penetrate the first sealing member 50, and the pipe 4 is connected to the opening 51. The opening 51 is provided, for example, in the lower end surface of the light distribution device 2. In the present embodiment, the liquid 8 is injected from the lower side of the light distribution device 2 and discharged from the lower side.

  The opening 51 may be provided in the upper end surface of the light distribution device 2. That is, the liquid 8 may be injected from above the light distribution device 2 and discharged from above. Further, the opening 51 may be provided on the side end surface of the light distribution device 2. Alternatively, the opening 51 may be provided so as to penetrate one of the first substrate 10 and the second substrate 20.

  The air holes 52 are holes for letting air in and out of the gap 40. The air hole 52 is provided so as to penetrate the first sealing member 50. Although not shown in FIG. 2, a pipe is connected to the air hole 52, and a valve 7b is provided in the pipe.

  Further, the air hole 52 may be provided with a filter that suppresses the permeation of the liquid 8 and allows gas to pass therethrough so that the liquid 8 does not leak. The air holes 52 are provided in the upper end surface of the light distribution device 2.

  The first sealing member 50 may include a highly rigid spacer and an adhesive layer that adheres the spacer to each of the first substrate 10 and the second substrate 20. For example, the spacer maintains the space between the first substrate 10 and the second substrate 20, and is formed using a resin material such as PET or a metal material. The opening 51 and the air hole 52 may be provided so as to penetrate the spacer. The adhesive layer is formed using a resin material such as a thermosetting resin or an ultraviolet curable resin.

[Second concavo-convex structure layer]
The second concavo-convex structure layer 70 is a finely-shaped layer arranged on the main surface 11 of the first substrate 10. As shown in FIG. 2, the second concavo-convex structure layer 70 has a plurality of second convex portions 71 arranged side by side in one direction.

  Specifically, the second concavo-convex structure layer 70 is a concavo-convex structure body composed of a plurality of second convex portions 71 having a micro-order size. In the example shown in FIG. 2, the plurality of second convex portions 71 are individually separated and are supported by the base layer at the root (on the side of the first substrate 10). That is, a flat surface is provided between two adjacent second convex portions 71. The base layer is, for example, a portion left as a residual film when the plurality of second convex portions 71 is molded. The plurality of second convex portions 71 may be connected to each other at their roots, and a flat surface may not be provided between two adjacent second convex portions 71. That is, the cross-sectional shape of the concave portion between the two adjacent second convex portions 71 may be V-shaped. For example, the second concavo-convex structure layer 70 is provided in contact with the main surface 11 without interposing another member such as an electrode layer. A transparent adhesive layer or the like may be provided between the second uneven structure layer 70 and the first substrate 10.

  The second uneven structure layer 70 has a light distribution structure that totally reflects incident light. The light distribution structure includes a plurality of second convex portions 71.

  The plurality of second convex portions 71 are arranged side by side in the Z-axis direction. The plurality of second protrusions 71 are long protrusions that extend in a direction orthogonal to the arrangement direction (that is, the Z-axis direction). Specifically, the plurality of second convex portions 71 are formed in stripes extending in the X-axis direction while maintaining the cross-sectional shape (YZ cross section) orthogonal to the X-axis. For example, each of the plurality of second convex portions 71 is a trapezoidal column that is arranged laterally with respect to the first substrate 10. The plurality of second convex portions 71 may extend in a meandering manner along the X-axis direction. For example, the plurality of second protrusions 71 may be formed in a wavy line stripe shape in a plan view.

  As shown in FIG. 2, each of the plurality of second convex portions 71 has a shape that tapers from the root to the tip. Specifically, the cross-sectional shape of each of the plurality of second convex portions 71 is a tapered shape that tapers along the direction from the first substrate 10 to the third substrate 60. In the present embodiment, the cross-sectional shape of the plurality of second convex portions 71 in the YZ cross section is a trapezoid that tapers along the thickness direction of the light distribution device 2, but is not limited to this. The cross-sectional shape of the second convex portion 71 may be a triangle, another polygon, or a polygon including a curve.

  FIG. 4 is a cross-sectional view of the second convex portion 71 of the second uneven structure layer 70 included in the light distribution device 2 according to this embodiment. Although FIG. 4 shows a YZ cross section, the cross section is not shaded.

  As shown in FIGS. 2 and 4, each of the plurality of second convex portions 71 has side surfaces 71a and 71b. The side surfaces 71a and 71b are surfaces that intersect in the Z-axis direction. At least one of the side surfaces 71a and 71b is an inclined surface that is inclined at a predetermined inclination angle with respect to the direction orthogonal to the main surface 21 (that is, the Y axis direction). The distance between the side surface 71a and the side surface 71b, that is, the width of the second convex portion 71 gradually decreases from the first substrate 10 toward the third substrate 60.

  The side surface 71a is an example of a second side surface. For example, when the light distribution device 2 is arranged so that the Z axis is aligned in the vertical direction, the side surface 71a is located above the vertical side of the plurality of side surfaces forming the second convex portion 71. It is the side of the side. As shown in FIG. 4, the side surface 71a is a refracting surface that refracts the incident lights L1 and L2.

  The side surface 71b is an example of the second side surface, and, for example, when the light distribution device 2 is arranged so that the Z axis is aligned with the vertical direction, the side surface 71b is vertically downward among the plurality of side surfaces forming the second convex portion 71. It is the side of the side. The side surface 71b is a reflecting surface that reflects the incident lights L1 and L2. The reflection here is total reflection, and the side surface 71b functions as a total reflection surface.

Each inclination angle beta ₂ of the inclination angle beta ₁ and the side surface 71b of the side surface 71a is in the range 20 ° or less, for example 10 ° or more. In other words, the two base angles of the trapezoid or the triangle, which is the cross-sectional shape of the second convex portion 71, are 70 ° or more and 80 ° or less, respectively. The inclination angle beta ₂ of the inclination angle beta ₁ and side 71b of the side surface 71a, may be different from each other, it may be equal. That is, the cross-sectional shape of the second convex portion 71 may be an isosceles trapezoid or an isosceles triangle. The inclination angles β ₁ of the side surfaces 71a of the plurality of second convex portions 71 may be equal to or different from each other. The inclination angles β ₂ of the side surfaces 71b of the plurality of second convex portions 71 may be equal to or different from each other.

  The height of each of the plurality of second convex portions 71 is, for example, 100 μm or more. When the height is 100 μm or more, the side surfaces 71b and 71b that reflect light can be widely secured. Therefore, the amount of light to be distributed becomes large, so that the light distribution rate can be increased.

  The aspect ratio of each of the plurality of second convex portions 71 is, for example, 2 or less. The aspect ratio is the ratio of the height to the width of the root of the second convex portion 71. When the aspect ratio is 2 or less, the physical strength of the second convex portion 71 can be increased.

  The interval between two adjacent second convex portions 71 is, for example, 10 μm or more and 40 μm or less. The interval is the distance between the roots of two adjacent second convex portions 71. That is, the interval corresponds to the width of the flat surface of the concave portion between the two adjacent second convex portions 71. When the distance between two adjacent second convex portions 71 is 40 μm or less, the in-plane density of the second convex portions 71 can be increased. Therefore, the amount of light to be distributed becomes large, so that the light distribution rate can be increased.

  The height of each of the plurality of second convex portions 71 may be 1 mm or more. That is, the plurality of second convex portions 71 may be convex portions having a millimeter order size.

  In the present embodiment, the shapes of the plurality of second convex portions 71 are the same as each other, but may be different. For example, the plurality of second protrusions 71 may include a plurality of protrusions having different heights. For example, the heights of two adjacent second convex portions 71 may be different. The height of each of the plurality of second convex portions 71 may be, for example, a value randomly selected from a plurality of set values.

  The second concavo-convex structure layer 70 is formed using, for example, an ultraviolet curable resin material. Specifically, the second concavo-convex structure layer 70 can be formed by molding or nanoimprinting.

  As a material of the second concavo-convex structure layer 70, for example, a resin material using light transmittance such as acrylic resin, epoxy resin, or silicone resin can be used. The refractive index of the second concavo-convex structure layer 70 is, for example, in the range of 1.4 or more and 1.8 or less. In the present embodiment, the second concavo-convex structure layer 70 is formed using, for example, an acrylic resin having a refractive index of about 1.5.

[Second sealing member]
The second sealing member 90 is an annular member for connecting the first substrate 10 and the third substrate 60. Specifically, the second sealing member 90 is provided along each end of the first substrate 10 and the third substrate 60. Since each of the first substrate 10 and the third substrate 60 has a rectangular shape in plan view, the second sealing member 90 is provided in a rectangular annular shape. That is, the second sealing member 90 is provided along each of the four sides of the first substrate 10 and the third substrate 60 in a plan view.

  The second sealing member 90 adheres the first substrate 10 and the third substrate 60 at the peripheral edge portion. By this adhesion, a gap is formed between the adjacent second convex portions 71. As shown in FIG. 2, the gap is filled with the gas 9b.

  The gas 9b 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, the gas 9b may be dry air, nitrogen, or an inert gas. The inert gas is, for example, argon, but is not particularly limited. Alternatively, instead of the gas 9b, a space between the adjacent second convex portions 71 may be in a vacuum state (state sufficiently lower than atmospheric pressure).

[Light distribution characteristics of two types of convex portions]
Here, regarding the difference in the light distribution characteristics based on the difference in inclination angle between the plurality of first convex portions 31 included in the first concave-convex structure layer 30 and the plurality of second convex portions 71 included in the second concave-convex structure layer 70. explain.

  As described above, since the first convex portion 31 and the second convex portion 71 have different side surface inclination angles, even if light having the same incident angle is incident on the first convex portion 31 and the second convex portion 71. The angle of light emitted by total reflection, that is, the emission angle of the light distribution is different. For this reason, in the incident light to the light distribution device 2, the range of the incident angle at which the light can be totally reflected in the optimum direction is different between the first convex portion 31 and the second convex portion 71.

  It should be noted that the optimum direction means that when the light distribution device 2 is applied to a window of a building, it is possible to allow sunlight to reach deep inside the room without giving glare to a person indoors. Direction. The optimum direction is, for example, a range of 8 ° or more and 10 ° or less when the emission angle is upward, and a first convex shape so that the emission angle of more light is upward and is 3.6 ° or more and 80 ° or less. The shapes of the portion 31 and the second convex portion 71 are defined.

  For example, the second convex portion 71 can distribute sunlight having an incident angle smaller than a predetermined angle in an optimal direction, such as the light L1 shown by the solid line in FIG. That is, the second convex portion 71 is a convex portion for low-angle incidence that is excellent in light distribution when the sun altitude is smaller than the threshold value. The predetermined angle and the threshold value are 45 °, for example.

  Specifically, the second convex portion 71 is capable of causing light incident at 20 ° downward to be emitted at 8 ° upward by total reflection by the side surface 71b. In addition, the second convex portion 71 can emit light that is incident at 45 ° downward and is emitted at 33 ° upward. In addition, the second convex portion 71 can emit light that is incident downward at 70 ° and upward at 58 °.

  Like the light L2 indicated by the broken line in FIG. 4, the second convex portion 71 can also emit light incident at a high angle upward by total reflection, but since the emission angle is too large, The light is distributed to the side close to the optical device 2 (for example, near the window). That is, it is difficult for the second convex portion 71 to allow the light incident at a high angle to reach the inside of the room. In the present embodiment, the light L2 reflected upward at a high angle can be advanced in the optimum direction by refracting the light L2 by the first convex portion 31.

  Specifically, as shown in FIG. 3, the first convex portion 31 totally reflects the side surface 71b of the second convex portion 71 and refracts the light L2 traveling upward at the side surface 31b. As a result, the light L2 has a smaller upward angle, and can travel further inside the room. For example, the upward 58 ° light reflected by the side surface 71b of the second convex portion 71 can be emitted from the second substrate 20 upward 10 °. As described above, the first convex portion 31 can utilize the total reflection by the second convex portion 71 to distribute sunlight having an incident angle of a predetermined angle or more in an optimum direction.

  As described above, the first convex portion 31 and the second convex portion 71 have light distribution characteristics different from each other. In the present embodiment, the control unit 6 controls the injection and the discharge of the liquid 8 based on the solar altitude (that is, the incident angle of light), so that each of the first convex portion 31 and the second convex portion 71. Effectively use the light distribution characteristics. The operation and optical state of the optical device 1 according to this embodiment will be described below.

[Operation and optical state]
Next, the operation and optical state of the light distribution device 2 according to this embodiment will be described. Here, the case where the refractive index n1 of the first uneven structure layer 30, the refractive index n2 of the liquid 8 and the refractive index n3 of the second uneven structure layer 70 are all 1.5 will be described.

  In the optical device 1, the liquid 8 is repeatedly injected into and discharged from the gap 40. In the present embodiment, the light distribution device 2 can be in two optical states, the first light distribution state shown in FIG. 5 and the first light distribution state shown in FIG. The controller 6 controls injection and discharge of the liquid 8 to switch between the two optical states.

  For example, the control unit 6 changes the optical state of the light distribution device 2 to the optical state indicated by the instruction at the timing of receiving the instruction from the user. Further, for example, the control unit 6 changes to either the first light distribution state or the second light distribution state based on the sun altitude (that is, time). For example, the control unit 6 changes the optical state of the light distribution device 2 to the first light distribution state when the sun altitude is lower than the threshold value. The control unit 6 changes the optical state of the light distribution device 2 to the second light distribution state when the sun altitude is higher than the threshold value. The threshold is, for example, 45 °, but is not limited to this.

  Hereinafter, details of the two optical states will be described with reference to FIGS. 5 and 6.

<First light distribution state (low-angle incidence)>
FIG. 5 is a sectional view showing the first light distribution state for low-angle incidence of the light distribution device 2 of the optical device 1 according to the present embodiment. The first light distribution state is a light distribution state suitable when the incident angle of sunlight is small, that is, when the sun altitude is low. For example, when the optical state is the first light distribution state, the light distribution device 2 can efficiently propagate the sunlight when the sun altitude is 20 ° or more and less than 45 ° to the interior of the room. .

  Note that, in FIG. 5, the path of the light L that is obliquely incident on the light distribution device 2 is indicated by an arrow. The light L corresponds to the sunlight that enters obliquely downward from the outside to the inside when the light distribution device 2 is used for a window. The same applies to FIG.

  As shown in FIG. 5, the side surfaces 71a and 71b of the second convex portion 71 of the second uneven structure layer 70 are in contact with the gas 9b. Since the gas 9b is, for example, air, its refractive index is 1. Since the difference between the refractive index of the second concavo-convex structure layer 70 and the refractive index of the gas 9b is about 0.5, the light L is optically acted upon entering the second concavo-convex structure layer 70. Specifically, since the plurality of second convex portions 71 configure a light distribution structure, the light L is distributed. More specifically, the light L incident on the light distribution device 2 is refracted by the side surfaces 71a of the plurality of second convex portions 71 and then totally reflected by the side surface 71b. The light L totally reflected by the side surface 71b enters the first substrate 10.

  The gap 40 is filled with the liquid 8. Since the refractive index n1 of the first concavo-convex structure layer 30 and the refractive index n2 of the liquid 8 are equal, the light L is not optically affected at the interface between the first convex portion 31 and the liquid 8. That is, the light L is not refracted or totally reflected by any of the side surfaces 31 a and 31 b of the first convex portion 31. In other words, the optical state between the first substrate 10 and the second substrate 20 is the transparent state. Therefore, the light L totally reflected by the side surface 71b passes through the first substrate 10, the liquid 8 and the first concavo-convex structure layer 30 as it is, and is emitted from the second substrate 20. As shown in FIG. 4, the second convex portion 71 can cause the light L that is incident at a low angle to travel toward the inner part of the room.

  In this way, the light distribution device 2 is in a light distribution state suitable for low angles (that is, the first light distribution state). Thereby, the light can be efficiently taken indoors.

  Although not shown in FIG. 5 for simplification of description, the light L is actually refracted according to the difference in the refractive index when the medium passing therethrough changes. Specifically, the light L enters the third substrate 60, exits from the second substrate 20, passes through the interface between the first substrate 10 and the liquid 8, and the like, depending on the refractive index difference. Refract. The same applies to FIG. 6 described later.

  As shown in FIG. 5, the first light distribution state is formed by injecting the liquid 8 into the gap 40. For example, the control unit 6 opens the valves 7 a and 7 b and controls the pump 5 to inject the liquid 8 into the gap 40. By injecting the liquid 8 into the gap 40, the gas 9a contained in the gap 40 is discharged from the air hole 52. The control unit 6 closes the valves 7a and 7b after the liquid 8 is completely filled in the gap 40. Thereby, the optical state of the light distribution device 2 can be set to the first light distribution state.

<Second light distribution state (high-angle incidence)>
FIG. 6 is a sectional view showing a second light distribution state for high-angle incidence of the light distribution device 2 of the optical device 1 according to the present embodiment. The second light distribution state is a light distribution state suitable when the incident angle of sunlight is large, that is, when the altitude of the sun is high. For example, when the optical state is the second light distribution state, the light distribution device 2 can efficiently propagate sunlight at a sun altitude of 45 ° or more and 70 ° or less to the interior of the room. .

  As shown in FIG. 6, the optical action of the light L entering the light distribution device 2 by the second convex portion 71 of the second concavo-convex structure layer 70 is the same as that shown in FIG. That is, the light L incident on the light distribution device 2 is refracted by the side surfaces 71a of the plurality of second convex portions 71 and then totally reflected by the side surface 71b. The light totally reflected by the side surface 71b enters the first substrate 10. The light L totally reflected by the side surface 71b has a larger angle of reflection as compared with the case shown in FIG. That is, the light L is incident on the first substrate 10 at an upward angle as compared with the case of the first light distribution state shown in FIG.

  Further, the liquid 8 is discharged from the gap 40, and the gas 9a is introduced instead. Since the gas 9a is, for example, air, its refractive index is 1. Since the difference between the refractive index n1 of the first concavo-convex structure layer 30 and the refractive index of the gas 9a is about 0.5, the light L is optically acted upon entering the first concavo-convex structure layer 30. Specifically, since the plurality of first protrusions 31 form a light distribution structure, the light L is distributed by being refracted. More specifically, the upwardly propagating light L is refracted by the side surface 31b, so that the upward angle is reduced and the light L is emitted from the second substrate 20.

  In this way, the light distribution device 2 is in a light distribution state suitable for high angles (that is, the second light distribution state). Thereby, the light can be efficiently taken indoors.

  As shown in FIG. 5, the second light distribution state is formed by discharging the liquid 8 from the gap 40. For example, when changing from the first light distribution state to the second light distribution state, the controller 6 discharges the liquid 8 from the gap 40 by opening the valves 7a and 7b. For example, the liquid 8 is discharged to the container 3 from the opening 51 through the pipe 4 due to its own weight. At this time, the control unit 6 may cause the liquid 8 to flow in the direction from the gap 40 to the container 3 by controlling the pump 5. As a result, the liquid 8 is quickly discharged, and the time required for switching the optical state can be shortened.

  At the same time as the liquid 8 is discharged through the opening 51, the gas 9a is introduced into the gap 40 through the air hole 52. The control unit 6 closes the valves 7a and 7b after the liquid 8 is completely discharged from the gap 40 and the whole gap 40 is filled with the gas 9a. Thereby, the optical state of the light distribution device 2 can be set to the second light distribution state.

[Effect]
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 arranged so as to face the first substrate 10, and a main surface of the second substrate 20. A first concavo-convex structure layer 30 having a plurality of first convex portions 31 arranged side by side in one direction, the first concavo-convex structure layer 30 being disposed on the first main surface which is the main surface facing the first substrate 10; On the main surface of the gap portion 40 provided between the first concave-convex structure layer 30 and the first substrate 10 or the second substrate 20, the main surface opposite to the side where the gap portion 40 is provided. A third substrate 60 having a light-transmitting property, which is arranged to face a certain second main surface, and a third main surface and a second main surface which are main surfaces of the third substrate 60 facing the second main surface. And a second concave-convex structure layer 70 having a plurality of second convex portions 71 arranged side by side in one direction. The container 3 stores the liquid that is injected into the gap 40 and discharged from the gap 40.

  Thereby, the optical state of the light distribution device 2 can be adjusted by controlling the injection and the discharge of the liquid 8 into the gap 40. For example, when the liquid 8 is discharged from the gap 40, the difference in refractive index between the first convex portion 31 and the gap 40 (that is, the gas 9a) becomes large. Therefore, it is possible to increase the optical effect that the light receives when passing through the first convex portion 31, and thus it becomes easy to bend the light in a desired direction to proceed. Therefore, for example, when the light distribution device 2 is installed in a window, it is possible to increase the amount of light that illuminates the indoor ceiling (that is, the distributed light). Further, since the second concave-convex structure layer 70 is provided between the first substrate 10 and the third substrate 60, it is difficult for the second concave-convex structure layer 70 to be directly impacted from the outside. Therefore, the durability and reliability of the light distribution device 2 can be improved.

  As described above, according to the optical device 1 according to the present embodiment, it is possible to efficiently take in light indoors when used for a window.

  Further, for example, the refractive index of the liquid 8 is equal to the refractive index of the first concavo-convex structure layer 30.

  Accordingly, when the liquid 8 is injected into the gap 40, the optical state of the light distribution device 2 can be made transparent.

  Further, for example, the second uneven structure layer 70 is in contact with the second main surface and the third main surface.

  Thereby, the light distribution device 2 can be thinned.

  Further, for example, the space between the adjacent second convex portions 71 of the second concavo-convex structure layer 70 is filled with the gas 9b.

  Thereby, the difference in refractive index between the side surfaces 71a and 71b of the second convex portion 71 and the gas 9b can be easily increased. Therefore, the amount of light totally reflected by the second convex portion 71 increases. When the light distribution device 2 is installed in a window, the amount of light that illuminates the indoor ceiling (that is, the light that is distributed) increases.

Further, for example, each of the plurality of first convex portions 31 has a side surface 31b, and each of the plurality of second convex portions 71 has a side surface 71b. The inclination angle α ₂ of the side surface 31b with respect to the direction orthogonal to the first main surface is larger than the inclination angle β ₂ of the side surface 71b with respect to the direction orthogonal to the first main surface.

  Thereby, since the first convex portion 31 and the second convex portion 71 have different side surface inclination angles, the light is efficiently distributed regardless of whether the incident angle of the light incident on the light distribution device 2 is large or small. be able to. Specifically, the light distribution device 2 can efficiently propagate sunlight when the altitude of the sun is 20 ° or more and 70 ° or less to the interior of the room.

  Further, for example, the second concavo-convex structure layer 70 has a light distribution structure in which incident light is totally reflected by the side surface 71b, and the first concavo-convex structure layer 30 is incident in a state where the liquid 8 is discharged from the gap portion 40. And has a light distribution structure that refracts the light that is totally reflected by the side surface 71b.

  For example, by discharging the liquid 8 from the gap 40, light having a large incident angle can be totally reflected by the side surface 71b of the second convex portion 71 and refracted by the side surface 31b of the first convex portion 31. . As a result, the upward angle after total reflection by the side surface 71b can be made smaller, and the light can be made to travel further toward the interior.

Further, for example, the inclination angle α ₂ of the side surface 31b is 20 ° or more and 35 ° or less, and the inclination angle β ₂ of the side surface 71b is 10 ° or more and 20 ° or less.

  Accordingly, the sunlight when the sun altitude is low can be efficiently advanced to the inner part of the room by the second convex portion 71, and the sunlight when the sun altitude is high is the second convex portion 71 and the first convex portion. With the portion 31, it is possible to efficiently proceed to the interior of the room.

  Further, for example, the optical device 1 according to the present embodiment controls the pump 5 that performs at least one of injecting the liquid 8 into the gap 40 and discharging the liquid 8 from the gap 40, and the pump 5. And a control unit 6.

  As a result, at least one of the injection and the discharge of the liquid 8 to and from the gap 40 can be performed quickly, so that the optical state of the light distribution device 2 can be switched smoothly.

  Further, for example, the control unit 6 controls the pump 5 according to the sun altitude.

  As a result, an optical state suitable for the altitude of the sun can be formed, so that the efficiency of taking light into the room can be improved.

  Further, for example, the control unit 6 causes the gap portion 40 to be filled with the liquid 8 when the sun altitude is lower than the threshold value, and discharges the liquid 8 from the gap portion 40 when the sun altitude is higher than the threshold value.

  As a result, light can be efficiently taken indoors both when the sun altitude is high and when the sun altitude is low.

(Modification)
Hereinafter, a modified example of the optical device according to the present embodiment will be described with reference to FIG. 7.

  FIG. 7 is a schematic diagram showing the configuration of the optical device 101 according to the present modification. The optical device 101 according to this modification includes a plurality of sets of the light distribution device 2, the container 3, the pipe 4, the pump 5, and the valves 7a and 7b of the optical device 1 according to the embodiment.

  Specifically, as shown in FIG. 7, the optical device 101 includes the light distribution devices 2 and 102 and the containers 3 and 103. In this modification, the optical device 101 further includes pipes 4 and 104, pumps 5 and 105, a control unit 106, and valves 7a, 7b, 107a and 107b. The optical device 101 also includes the liquid 8 contained in the container 3 and the liquid 108 contained in the container 103.

  The light distribution device 102, the container 103, the pipe 104, the pump 105, the valves 107a and 107b, and the liquid 108 are the light distribution device 2, the container 3, the pipe 4, the pump 5, the valves 7a and 7b according to the embodiment, respectively. In addition, it is the same as the liquid 8. The control unit 106 is similar to the control unit 6 and controls the pumps 5 and 105 and the valves 7a, 7b, 107a and 107b.

  In this modified example, as shown in FIG. 7, the light distribution device 2 and the light distribution device 102 are arranged side by side in a plane in a plan view. For example, the light distribution device 2 and the light distribution device 102 are arranged side by side vertically so as to share one side. Alternatively, the light distribution device 2 and the light distribution device 102 may be arranged side by side on the left and right. Further, the optical device 101 may include three or more light distribution devices 2 or 102. For example, the plurality of light distribution devices 2 may be arranged vertically and horizontally in a matrix.

  As described above, the optical device 101 according to the present modified example includes a plurality of sets of light distribution devices and containers, and the plurality of light distribution devices 2 and 102 are in-plane when the first main surface is viewed in plan. They are arranged side by side.

  Accordingly, the light distribution device 2 or 102 can be freely arranged, and thus the light distribution device 2 or 102 can be used for a wide-sized window.

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

  For example, the second uneven structure layer 70 may be provided on the main surface 61 of the third substrate 60.

  Further, the pipe 4 may be provided with a flow rate sensor that detects the flow rate of the liquid 8 flowing through the pipe. The controller 6 may adjust the injection amount and the discharge amount of the liquid 8 based on the flow rate detected by the flow rate sensor.

  Further, for example, the optical device 1 may not include the pump 5. The liquid 8 may be moved using the own weight of the liquid 8. 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 8 can be injected from the container 3 into the gap 40. The liquid 8 can be discharged from the gap 40 to the container 3 by lowering the container 3 to a position lower than the gap 40.

  Further, for example, the optical device 1 may not include at least one of the valves 7a and 7b.

  In addition, for example, the liquid 8 does not have to be translucent. The liquid 8 may have a light scattering property or a light shielding property. For example, the liquid 8 may contain colored particles such as black and may also contain light scattering particles. Thereby, the light distribution device 2 can realize a scattering state or a light shielding state instead of the transparent state. Alternatively, the liquid 8 may contain heat reflecting particles or heat absorbing particles. The container 3 may be provided with an opening for containing the liquid 8 in the container 3, and the liquid 8 may be replaceable. Alternatively, the container 3 may be detachable from the pipe 4.

  Further, for example, when the refractive index of the first concavo-convex structure layer 30 is n1 and the refractive index of the liquid 8 is n2, the absolute value of n1-n2 may be larger than 0.01. That is, the refractive index of the first concavo-convex structure layer 30 may not be equal to the refractive index of the liquid 8.

  Further, for example, the capacity of the container 3 may be smaller than the capacity of the gap portion 40. For example, the sum of the capacity of the container 3 and the capacity of the pipe 4 may be greater than or equal to the capacity of the gap 40. As a result, all of the liquid 8 injected into the gap 40 can be discharged to the container 3 and the pipe 4.

  Alternatively, the liquid 8 may not be completely discharged from the gap 40. That is, the liquid 8 may remain in a part of the gap 40. For example, the height of the liquid surface can be adjusted by adjusting the injection amount of the liquid 8. The optical state of the light distribution device 2 can be made different between the upper part and the lower part with the height of the liquid surface as a boundary.

  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 for taking in light indoors. At this time, when the light from the lower part of 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. Therefore, the lower portion of the light distribution device 2 is always in the state where the gap 40 is filled with the liquid 8, and the optical state may be the 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 8 in the gap 40 is adjusted within the range of 1 m on the upper side, and the liquid 8 is always filled within the range of 1 m on the lower side. Good. Further, the first uneven structure layer 30 may not be provided below the light distribution device 2. That is, the first 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 partial region. The same may be applied to the second uneven structure layer 70.

  Further, for example, the inlet and the outlet for the liquid 8 to the gap 40 may be different. For example, the first sealing member 50 of the light distribution device 2 may have a plurality of openings 51. The optical device 1 may include a plurality of pipes 4 connected to each of the plurality of openings 51. With this, by separating the inlet and the outlet of the liquid 8, the flow of the liquid 8 can be easily controlled, and the optical state of the light distribution device 2 can be smoothly switched. In addition, each of the plurality of openings 51 may be an inlet and an outlet.

  Each of the plurality of openings 51 is provided in the lower end surface of the light distribution device 2, for example. Alternatively, at least one of the plurality of openings 51 may be provided on the upper end surface or the side end surface of the light distribution device 2. Similarly, a plurality of air holes 52 may be provided.

  Further, a circulation path for the liquid 8 may be formed. For example, the liquid 8 may flow through the container 3, one pipe 4, one opening 51, the gap 40 of the light distribution device 2, another opening 51, and another pipe 4 in order.

  The optical device 1 may include a plurality of containers 3. Each of the plurality of containers 3 contains a different type of liquid 8. 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.

Further, for example, the plurality of first convex portions 31 and the plurality of second convex portions 71 may have the same side surface inclination angle. At least one of the inclination angle α ₁ of the side surface 31a of the first convex portion 31 and the inclination angle α ₂ of the side surface 31b may be smaller than 20 ° or larger than 35 °. Further, at least one of the inclination angle β ₁ of the side surface 71a of the second convex portion 71 and the inclination angle β ₂ of the side surface 71b may be smaller than 10 ° or larger than 20 °.

  Further, for example, a resin having a light-transmitting property may be filled between the adjacent second convex portions 71 of the second concavo-convex structure layer 70. That is, the side surfaces 71a and 71b of the second convex portion 71 may contact the resin instead of contacting the gas 9b. The refractive index of the resin is different from the refractive index of the second convex portion 71. For example, the absolute value of the difference between the refractive index of the resin and the refractive index of the second convex portion 71 is larger than 0.1. The absolute value of the difference may be greater than 0.2, greater than 0.3, or greater than 0.5. Since the difference in the refractive index between the resin and the second convex portion 71 becomes large, the amount of light totally reflected by the second convex portion 71 increases, so that the efficiency of collecting light can be improved.

  Further, for example, the light incident on the light distribution device 2 is not limited to natural light such as sunlight, but 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, and may be installed in, for example, a window of a car. The light distribution device 2 can also be used as, for example, a light distribution control member such as a translucent cover of a lighting fixture. Alternatively, the light distribution device 2 can also be used as a blind member that utilizes the scattering of light at the interface of the first concavo-convex structure layer 30.

  In addition, it is realized by making various modifications to those skilled in the art by those skilled in the art, and by arbitrarily combining the components and functions of each embodiment without departing from the spirit of the present invention. The form is also included in the present invention.

1, 101 Optical device 2, 102 Light distribution device 3, 103 Container 5, 105 Pump (liquid sending part)
6, 106 Control unit 8, 108 Liquid 9a, 9b Gas 10 First substrate 11 Main surface 20 Second substrate 21 Main surface 30 First uneven structure layer 31 First convex portions 31a, 31b Side surface 40 Gap portion 60 Third substrate 61 Main surface 70 Second uneven structure layer 71 Second convex portions 71a, 71b Side surface

Claims (11)

A light distribution device that distributes incident light,
With a container,
The light distribution device,
A first substrate having translucency,
A second substrate having a light-transmitting property, which is arranged so as to face the first substrate;
First unevenness having a plurality of first convex portions arranged in one direction and arranged on a first main surface which is a main surface of the second substrate and is a main surface facing the first substrate. A structural layer,
A gap portion provided between the first substrate and the first concavo-convex structure layer,
The main surface of the first substrate or the second substrate, which has a light-transmitting property, is arranged so as to face a second main surface which is a main surface on the side opposite to the side where the gap is provided. A third substrate,
A plurality of third main surfaces, which are the main surfaces of the third substrate facing the second main surface, and a plurality of first main surfaces, which are arranged on one side of the second main surface. A second concave-convex structure layer having two convex portions,
An optical device in which the container contains a liquid that is injected into the gap and discharged from the gap. The optical device according to claim 1, wherein a refractive index of the liquid is equal to a refractive index of the first concavo-convex structure layer. The optical device according to claim 1, wherein the second uneven structure layer is in contact with the second main surface and the third main surface. The optical device according to claim 1, wherein a space between the adjacent second convex portions of the second concave-convex structure layer is filled with gas. Each of the plurality of first protrusions has a first side surface,
Each of the plurality of second convex portions has a second side surface,
The inclination angle of the said 1st side surface with respect to the direction orthogonal to the said 1st main surface is larger than the inclination angle of the said 2nd side surface with respect to the direction orthogonal to the said 1st main surface. Optical device. The second concave-convex structure layer has a light distribution structure that totally reflects incident light on the second side surface,
The said 1st uneven structure layer has a light distribution structure which refracts the light which the said liquid injects in the state discharged | emitted from the said gap | interval part, and was totally reflected by the said 2nd side surface. Optical device. The inclination angle of the first side surface is 20 ° or more and 35 ° or less,
The optical device according to claim 5, wherein the second side surface has an inclination angle of 10 ° or more and 20 ° or less. A liquid feeding section that performs at least one of injecting the liquid into the gap and discharging the liquid from the gap,
The optical device according to claim 1, further comprising: a control unit that controls the liquid delivery unit. The optical device according to claim 8, wherein the control unit controls the liquid feeding unit according to a sun altitude. The optical unit according to claim 9, wherein the control unit causes the gap to be filled with the liquid when the sun altitude is lower than a threshold value, and discharges the liquid from the gap unit when the sun altitude is higher than the threshold value. apparatus. A plurality of sets of the light distribution device and the container,
The optical device according to any one of claims 1 to 10, wherein the plurality of light distribution devices are arranged side by side in a plane when the first main surface is viewed in plan.

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