WO2019130913A1 - Photoalignment control device - Google Patents

Photoalignment control device Download PDF

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Publication number
WO2019130913A1
WO2019130913A1 PCT/JP2018/042809 JP2018042809W WO2019130913A1 WO 2019130913 A1 WO2019130913 A1 WO 2019130913A1 JP 2018042809 W JP2018042809 W JP 2018042809W WO 2019130913 A1 WO2019130913 A1 WO 2019130913A1
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WO
WIPO (PCT)
Prior art keywords
light distribution
light
control device
layer
refractive index
Prior art date
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PCT/JP2018/042809
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French (fr)
Japanese (ja)
Inventor
旬臣 芝田
有宇 和家佐
太田　益幸
Original Assignee
パナソニックＩｐマネジメント株式会社
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Publication of WO2019130913A1 publication Critical patent/WO2019130913A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/165—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field
    • G02F1/166—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect
    • G02F1/167—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/19—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on variable-reflection or variable-refraction elements not provided for in groups G02F1/015 - G02F1/169

Definitions

  • the present invention relates to a light distribution control device.
  • Patent Document 1 discloses a liquid crystal optical element having a pair of transparent substrates, a pair of transparent electrodes formed on each of the pair of transparent substrates, and a prism layer and a liquid crystal layer sandwiched between the pair of transparent electrodes. It is disclosed.
  • the liquid crystal optical element changes the refractive index of the liquid crystal layer by a voltage applied to the pair of transparent electrodes, and changes the refraction angle of light passing through the interface between the slope of the prism and the liquid crystal layer.
  • an object of the present invention is to provide a light distribution control device that can brighten the indoor when used for a window and can suppress glare that a person who is indoors feels. .
  • a light distribution control device includes a light transmitting first substrate and a light transmitting second substrate disposed opposite to the first substrate.
  • a translucent first electrode layer and a second electrode layer disposed between the first substrate and the second substrate so as to face each other, the first electrode layer and the second electrode layer
  • a light distribution layer for distributing incident light wherein the light distribution layer is disposed so as to fill the space between the plurality of projections and the concavo-convex structure layer having the plurality of projections.
  • a refractive index variable layer whose refractive index changes in accordance with a voltage applied between the first electrode layer and the second electrode layer, and the light distribution layer changes the refractive index of the refractive index variable layer.
  • the light distribution ratio indicating the ratio of light distributed to the light transmitted through the light distribution control device is 27% or more, and travels to the direct light region with respect to light incident on the light distribution control device
  • the direct light ratio which indicates the ratio of light emitted, is 10% or less.
  • FIG. 1 is a cross-sectional view of a light distribution control device according to the embodiment.
  • FIG. 2 is an enlarged cross-sectional view of the light distribution control device according to the embodiment.
  • FIG. 3A is an enlarged sectional view for explaining a non-application mode (transparent state) of the light distribution control device according to the embodiment.
  • FIG. 3B is an enlarged cross-sectional view for explaining a first application mode (light distribution state) of the light distribution control device according to the embodiment.
  • FIG. 3C is an enlarged cross-sectional view for describing a second application mode (heat shielding state) of the light distribution control device according to the embodiment.
  • FIG. 4 is a figure which shows an example at the time of applying the light distribution control device which concerns on embodiment to the window of a building.
  • FIG. 4 is a figure which shows an example at the time of applying the light distribution control device which concerns on embodiment to the window of a building.
  • FIG. 5 is a figure which shows the questionnaire result of whether it felt glare with respect to the transmittance
  • FIG. 6 is a diagram showing the result of a questionnaire on how the window looks with respect to the haze of the window glass.
  • FIG. 7 is a figure which shows an example at the time of applying the light distribution control device which concerns on embodiment to the south window of a building.
  • FIG. 8 is a diagram showing an example in which the light distribution control device according to the embodiment is applied to a west-facing window of a building.
  • each drawing is a schematic view, and is not necessarily illustrated exactly. Therefore, for example, the scale and the like do not necessarily match in each figure. Further, in each of the drawings, substantially the same configuration is given the same reference numeral, and overlapping description will be omitted or simplified.
  • the term indicating the relationship between elements such as parallel or perpendicular, and the term indicating the shape of an element such as triangle or trapezoid, and the numerical range are not expressions expressing only strict meanings. This expression is meant to include a substantially equivalent range, for example, a difference of about several percent.
  • the x-axis, the y-axis and the z-axis indicate three axes of the three-dimensional orthogonal coordinate system.
  • the z-axis direction is the vertical direction
  • the direction perpendicular to the z-axis is the horizontal direction.
  • the positive direction of the z axis is vertically upward.
  • the “thickness direction” means the thickness direction of the light distribution control device, and is a direction perpendicular to the main surfaces of the first substrate and the second substrate, and “plan view” When viewed from the direction perpendicular to the main surface of the first substrate or the second substrate.
  • Embodiment [Overview] First, an outline of the light distribution control device according to the embodiment will be described with reference to FIGS. 1 and 2.
  • FIG. 1 is a cross-sectional view of a light distribution control device 1 according to the present embodiment.
  • FIG. 2 is an enlarged cross-sectional view of the light distribution control device 1 according to the present embodiment, and is an enlarged cross-sectional view of a region II surrounded by an alternate long and short dash line in FIG.
  • the light distribution control device 1 is an optical device that controls light incident on the light distribution control device 1.
  • the light distribution control device 1 is a light distribution element capable of changing the traveling direction of light incident on the light distribution control device 1 (that is, distributing light) and emitting the light.
  • the light distribution control device 1 is configured to transmit incident light, and the first substrate 10, the second substrate 20, the light distribution layer 30, and A first electrode layer 40 and a second electrode layer 50 are provided.
  • An adhesion layer may be provided on the surface of the first electrode layer 40 on the light distribution layer 30 side in order to bring the first electrode layer 40 into close contact with the uneven structure layer 31 of the light distribution layer 30.
  • the adhesion layer is, for example, a translucent adhesive sheet, or a resin material generally referred to as a primer.
  • the first electrode layer 40, the light distribution layer 30, and the second electrode layer 50 are disposed in this order along the thickness direction between the first substrate 10 and the second substrate 20 forming a pair. Configuration.
  • a plurality of particle-like spacers may be dispersed in the plane, or a columnar structure may be formed.
  • the light distribution control device 1 can be realized as, for example, a window with a light distribution function by being installed in a window of a building.
  • the light distribution control device 1 is used by, for example, being attached to a transparent substrate such as an existing window glass via an adhesive layer.
  • the light distribution control device 1 may be used as a window of a building itself.
  • the first substrate 10 is on the outdoor side
  • the second substrate 20 is on the indoor side
  • the refractive index of the refractive index variable layer 32 of the light distribution layer 30 is changed by the voltage applied between the first electrode layer 40 and the second electrode layer 50.
  • a difference in refractive index occurs at the interface between the uneven structure layer 31 and the refractive index variable layer 32, and light is distributed using refraction and reflection (total reflection) of light by the interface.
  • the first substrate 10 and the second substrate 20 are substrates having translucency.
  • a glass substrate or a resin substrate can be used as the first substrate 10 and the second substrate 20.
  • the material of the glass substrate examples include soda glass, alkali-free glass and high refractive index glass.
  • the material of the resin substrate examples include resin materials such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), acrylic (PMMA) or epoxy.
  • PET polyethylene terephthalate
  • PEN polyethylene naphthalate
  • PC polycarbonate
  • PMMA acrylic
  • 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.
  • the first substrate 10 and the second substrate 20 may be made of the same material, or may be made of different materials. Further, the first substrate 10 and the second substrate 20 are not limited to rigid substrates, and may be flexible substrates having flexibility. In the present embodiment, the first substrate 10 and the second substrate 20 are transparent resin substrates made of PET resin.
  • the second substrate 20 is an opposing substrate that faces the first substrate 10, and is disposed at a position that faces the first substrate 10.
  • the first substrate 10 and the second substrate 20 are disposed in parallel at a predetermined distance such as 1 ⁇ m to 1000 ⁇ m, for example.
  • the first substrate 10 and the second substrate 20 are bonded by a sealing resin such as an adhesive formed in the shape of a frame on the outer periphery of each end.
  • substrate 20 is rectangular shapes, such as a square or a rectangle, for example, it does not restrict to this, Polygons other than a circle or a square may be sufficient. Any shape may be employed.
  • the light distribution layer 30 is disposed between the first electrode layer 40 and the second electrode layer 50.
  • the light distribution layer 30 has translucency, and transmits incident light.
  • the light distribution layer 30 distributes the incident light. That is, when light passes through the light distribution layer 30, the light distribution layer 30 changes the traveling direction of the light.
  • the light distribution layer 30 has a concavo-convex structure layer 31 and a refractive index variable layer 32.
  • the light is reflected at the interface between the uneven structure layer 31 and the refractive index variable layer 32, whereby the traveling direction of the light passing through the light distribution control device 1 is bent.
  • the uneven structure layer 31 is a fine shape layer provided to make the surface (interface) of the variable-refractive-index layer 32 uneven.
  • the uneven structure layer 31 has a plurality of convex portions 33 and a plurality of concave portions 34, as shown in FIG.
  • the concavo-convex structure layer 31 is a concavo-convex structure body constituted by a plurality of convex portions 33 of micro order size.
  • a plurality of concave portions 34 are between the plurality of convex portions 33. That is, one concave portion 34 is between two adjacent convex portions 33.
  • FIG. 2 shows an example in which the plurality of convex portions 33 are individually separated, the present invention is not limited to this.
  • the plurality of convex portions 33 may be connected to each other at the root (the first electrode layer 40 side). That is, a layer (film) -like base portion to be a base of the convex portion 33 may be provided between the plurality of convex portions 33 and the first electrode layer 40.
  • the plurality of projections 33 are a plurality of projections arranged in the z-axis direction parallel to the main surface (the surface on which the first electrode layer 40 is provided) of the first substrate 10. That is, in the present embodiment, the z-axis direction is the direction in which the plurality of convex portions 33 are arranged.
  • the plurality of protrusions 33 are long ridges extending in a direction orthogonal to the direction in which the protrusions 33 are arranged.
  • the plurality of convex portions 33 are formed in a stripe shape extending in the x-axis direction.
  • Each of the plurality of protrusions 33 extends linearly along the x-axis direction.
  • each of the plurality of protrusions 33 is a triangular prism disposed sideways with respect to the first electrode layer 40.
  • the plurality of convex portions 33 may extend in a meandering manner along the x-axis direction.
  • the plurality of convex portions 33 may be formed in a wavy stripe.
  • the plurality of convex portions 33 are, for example, arranged at equal intervals along the z-axis direction.
  • the shape and size of each of the plurality of protrusions 33 are the same as one another, but may be different.
  • each of the plurality of projections 33 has a tapered shape from the root to the tip.
  • the cross-sectional shape of each of the plurality of protrusions 33 is a tapered shape that tapers in the direction from the first substrate 10 toward the second substrate 20.
  • the cross-sectional shape of the convex portion 33 in the yz cross section is a triangle that tapers in the thickness direction of the light distribution control device 1, but is not limited to this.
  • the cross-sectional shape of the convex portion 33 may be a trapezoid, another polygon, or a polygon including a curve.
  • each of the plurality of convex portions 33 has a pair of side surfaces 33a and 33b.
  • the pair of side surfaces 33a and 33b are surfaces intersecting in the z-axis direction.
  • Each of the pair of side surfaces 33a and 33b is an inclined surface which is inclined at a predetermined inclination angle with respect to the y-axis direction.
  • the distance between the pair of side surfaces 33 a and 33 b, that is, the width of the protrusion 33 gradually decreases from the first substrate 10 toward the second substrate 20.
  • the side surface 33 a is, for example, a side surface on the vertically lower side among the plurality of side surfaces constituting the convex portion 33 when the light distribution control device 1 is disposed such that the z axis coincides with the vertical direction.
  • the side surface 33a is a refractive surface that refracts incident light.
  • the side surface 33 b is, for example, the side surface on the vertically upper side among the plurality of side surfaces configuring the convex portion 33 when the light distribution control device 1 is disposed such that the z axis coincides with the vertical direction.
  • the side surface 33 b is a reflective surface that reflects incident light. The reflection here is total reflection, and the side surface 33b functions as a total reflection surface.
  • the width (length in the z-axis direction) of the plurality of protrusions 33 is, for example, 1 ⁇ m to 20 ⁇ m, and preferably 10 ⁇ m or less, but is not limited thereto.
  • the distance between two adjacent convex portions 33 is, for example, 0 ⁇ m to 100 ⁇ m, but is not limited to this. Two adjacent convex portions 33 may be in contact with each other, or may be arranged at a predetermined interval.
  • the uneven structure layer 31 As a material of the uneven structure layer 31, for example, a resin material having light transmittance such as an acrylic resin, an epoxy resin, or a silicone resin can be used.
  • the uneven structure layer 31 is formed of, for example, an ultraviolet curable resin material, and can be formed by molding or nanoimprinting.
  • the concavo-convex structure layer 31 can form a concavo-convex structure having a triangular cross section by molding using, for example, an acrylic resin having a refractive index of 1.5 for green light.
  • the refractive index variable layer 32 is disposed so as to fill the spaces between the plurality of convex portions 33 (that is, the concave portions 34). Specifically, the refractive index variable layer 32 is disposed so as to fill a gap formed between the first electrode layer 40 and the second electrode layer 50. For example, as shown in FIG. 2, since the convex portion 33 and the second electrode layer 50 are separated, the refractive index variable layer 32 is not limited to the concave portion 34, but the tip portion of the convex portion 33 and the second electrode layer It is arranged to fill the gap between 50 and 50.
  • the convex portion 33 and the second electrode layer 50 may be in contact with each other, and in this case, the refractive index variable layer 32 may be provided separately for each concave portion 34.
  • the refractive index of the variable-refractive-index layer 32 changes in accordance with the voltage applied between the first electrode layer 40 and the second electrode layer 50.
  • the refractive index variable layer 32 functions as a refractive index adjustment layer whose refractive index in the visible light band can be adjusted by application of an electric field.
  • the electric field changes in response to the voltage applied between the first electrode layer 40 and the second electrode layer 50.
  • a DC voltage is applied between the first electrode layer 40 and the second electrode layer 50 by a control unit (not shown) or the like.
  • variable-refractive-index layer 32 includes an insulating liquid 35 and nanoparticles 36 contained in the insulating liquid 35.
  • the refractive index variable layer 32 is a nanoparticle dispersion layer in which innumerable nanoparticles 36 are dispersed in the insulating liquid 35.
  • the insulating liquid 35 is a transparent liquid having an insulating property, and is a solvent serving as a dispersion medium in which the nanoparticles 36 are dispersed as a dispersoid.
  • a material having a refractive index (solvent refractive index) of about 1.3 to about 1.6 can be used.
  • the insulating liquid 35 having a refractive index of about 1.4 is used.
  • the kinematic viscosity of the insulating liquid 35 is preferably about 100 mm 2 / s.
  • the insulating liquid 35 has a low dielectric constant (for example, not more than the dielectric constant of the concavo-convex structure layer 31), a non-flammable property (for example, a high flash point of 250 ° C. or more) and a low volatility. It is also good.
  • the insulating liquid 35 is a hydrocarbon such as aliphatic hydrocarbon, naphtha, and other petroleum solvents, a low molecular weight halogen-containing polymer, or a mixture thereof.
  • the insulating liquid 35 is a halogenated hydrocarbon such as a fluorinated hydrocarbon.
  • silicone oil or the like can also be used.
  • a plurality of nanoparticles 36 are dispersed in the insulating liquid 35.
  • the nanoparticles 36 are fine particles of nano order size.
  • the particle diameter of the nanoparticles 36 is preferably ⁇ / 4 or less.
  • the particle diameter of the nanoparticles 36 is preferably as small as possible, preferably 100 nm or less, more preferably several nm to several tens nm.
  • the nanoparticles 36 are made of, for example, a high refractive index material. Specifically, the refractive index of the nanoparticles 36 is higher than the refractive index of the insulating liquid 35. In the present embodiment, the refractive index of the nanoparticles 36 is higher than the refractive index of the uneven structure layer 31.
  • metal oxide fine particles can be used as the nanoparticles 36.
  • the nanoparticles 36 may be made of a material having high transmittance.
  • transparent zirconia particles having a refractive index of 2.1 and made of zirconium oxide (ZrO 2 ) are used as the nanoparticles 36.
  • the nanoparticles 36 are not limited to zirconium oxide, and may be made of titanium oxide (TiO 2 : refractive index 2.5) or the like.
  • the nanoparticles 36 are charged charged particles.
  • the nanoparticles 36 can be positively (plus) or negatively (minus) charged.
  • the nanoparticles 36 are positively (plus) charged.
  • variable-refractive-index layer 32 configured in this manner, charged nanoparticles 36 are dispersed in the entire insulating liquid 35.
  • zirconia particles having a refractive index of 2.1 as the nanoparticles 36 are dispersed in the insulating liquid 35 having a solvent refractive index of about 1.4 as the refractive index variable layer 32.
  • the refractive index (average refractive index) of the entire refractive index variable layer 32 is set to be substantially the same as the refractive index of the concavo-convex structure layer 31 in a state where the nanoparticles 36 are uniformly dispersed in the insulating liquid 35. In the present embodiment, it is about 1.5.
  • the entire refractive index of the refractive index variable layer 32 can be changed by adjusting the concentration (amount) of the nanoparticles 36 dispersed in the insulating liquid 35. Although the details will be described later, the amount of the nanoparticles 36 is, for example, the extent of being buried in the recess 34 of the uneven structure layer 31. In this case, the concentration of the nanoparticles 36 to the insulating liquid 35 is about 10% to about 30%.
  • the nanoparticles 36 dispersed in the insulating liquid 35 are charged, when an electric field is applied to the refractive index variable layer 32, the nanoparticles 36 migrate in the insulating liquid 35 according to the electric field distribution, and the insulating liquid It is unevenly distributed within 35. Thereby, the particle distribution of the nanoparticles 36 in the refractive index variable layer 32 can be changed, and the concentration distribution of the nanoparticles 36 can be provided in the refractive index variable layer 32, so that the refractive index in the refractive index variable layer 32 Distribution changes. That is, the refractive index of the refractive index variable layer 32 partially changes.
  • the refractive index variable layer 32 functions as a refractive index adjustment layer that can mainly adjust the refractive index to light in the visible light band.
  • the refractive index variable layer 32 has, for example, the respective outer peripheries of the first substrate 10 on which the first electrode layer 40 and the concavo-convex structure layer 31 are formed, and the second substrate 20 on which the second electrode layer 50 is formed. It forms by inject
  • the refractive index variable material is the insulating liquid 35 in which the nanoparticles 36 are dispersed. An insulating liquid 35 in which the nanoparticles 36 are dispersed is sealed between the first substrate 10 and the second substrate 20.
  • the thickness of the refractive index variable layer 32 is, for example, 1 ⁇ m to 1000 ⁇ m, but is not limited thereto. As an example, when the height of the convex portion 33 of the uneven structure layer 31 is 10 ⁇ m, the thickness of the refractive index variable layer 32 is, for example, 40 ⁇ m.
  • first electrode layer 40 and the second electrode layer 50 are electrically paired and configured to be able to apply an electric field to the light distribution layer 30.
  • the first electrode layer 40 and the second electrode layer 50 are not only electrically but also disposed in a pair, and are disposed between the first substrate 10 and the second substrate 20 so as to face each other. ing. Specifically, the first electrode layer 40 and the second electrode layer 50 are disposed to sandwich the light distribution layer 30.
  • the first electrode layer 40 and the second electrode layer 50 have translucency and transmit incident light.
  • the first electrode layer 40 and the second electrode layer 50 are, for example, transparent conductive layers.
  • the material of the transparent conductive layer is a transparent metal oxide such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), a conductor containing resin made of a resin containing a conductor such as silver nanowire or conductive particles, or And metal thin films such as silver thin films can be used.
  • the first electrode layer 40 and the second electrode layer 50 may have a single-layer structure of these, or a laminated structure of these (for example, a laminated structure of a transparent metal oxide and a metal thin film).
  • each of the first electrode layer 40 and the second electrode layer 50 is ITO having a thickness of 100 nm.
  • the first electrode layer 40 is disposed between the first substrate 10 and the uneven structure layer 31. Specifically, the first electrode layer 40 is formed on the surface of the first substrate 10 on the light distribution layer 30 side.
  • the second electrode layer 50 is disposed between the refractive index variable layer 32 and the second substrate 20. Specifically, the second electrode layer 50 is formed on the surface of the second substrate 20 on the light distribution layer 30 side.
  • the first electrode layer 40 and the second electrode layer 50 are configured, for example, to enable electrical connection with an external power supply.
  • an electrode pad or the like for connection to an external power source may be drawn out from each of the first electrode layer 40 and the second electrode layer 50 and formed on the first substrate 10 and the second substrate 20.
  • the first electrode layer 40 and the second electrode layer 50 are each formed by depositing a conductive film such as ITO by, for example, vapor deposition or sputtering.
  • FIG. 3A is an enlarged cross-sectional view for explaining the non-application mode (transparent state) of the light distribution control device 1 according to the present embodiment.
  • FIG. 3A no voltage is applied between the first electrode layer 40 and the second electrode layer 50. Specifically, the first electrode layer 40 and the second electrode layer 50 are at the same potential. In this case, since no electric field is applied to the refractive index variable layer 32, the nanoparticles 36 are dispersed throughout the insulating liquid 35.
  • the refractive index of the variable-refractive-index layer 32 in the state in which the nanoparticles 36 are dispersed throughout the insulating liquid 35 is about 1.5, as described above.
  • the refractive index of the convex part 33 of the uneven structure layer 31 is about 1.5. That is, the refractive index of the refractive index variable layer 32 is equal to the refractive index of the uneven structure layer 31. Therefore, the refractive index is uniform throughout the light distribution layer 30.
  • the light distribution control device 1 when light L is incident from an oblique direction, there is no difference in the refractive index at the interface between the refractive index variable layer 32 and the concavo-convex structure layer 31, so the light travels straight.
  • the light distribution control device 1 is in a transparent state that transmits incident light substantially as it is (without changing the traveling direction).
  • FIG. 3B is an enlarged cross-sectional view for describing a first application mode (light distribution state) of the light distribution control device 1 according to the present embodiment.
  • a first voltage is applied between the first electrode layer 40 and the second electrode layer 50.
  • the first voltage having a potential difference of about several tens of volts is applied to the first electrode layer 40 and the second electrode layer 50.
  • a predetermined electric field is applied to the refractive index variable layer 32, so in the refractive index variable layer 32, the charged nanoparticles 36 migrate in the insulating liquid 35 according to the electric field distribution. That is, the nanoparticles 36 electrophorese in the insulating liquid 35.
  • the second electrode layer 50 has a higher potential than the first electrode layer 40. For this reason, the positively charged nanoparticles 36 migrate toward the first electrode layer 40 and enter and accumulate in the recesses 34 of the uneven structure layer 31.
  • the particle distribution of the nanoparticles 36 changes, and the refractive index distribution in the variable-refractive-index layer 32 is uniform. It disappears.
  • the concentration distribution of the nanoparticles 36 is formed in the refractive index variable layer 32.
  • the concentration of the nanoparticles 36 is high, and in the second region 32 b on the second electrode layer 50 side, the concentration of the nanoparticles 36 is low. Therefore, a refractive index difference occurs between the first region 32a and the second region 32b.
  • the refractive index of the nanoparticles 36 is higher than the refractive index of the insulating liquid 35.
  • the refractive index of the first region 32a in which the concentration of the nanoparticles 36 is high is higher than the refractive index of the second region 32b in which the concentration of the nanoparticles 36 is low, that is, the proportion of the insulating liquid 35 is high.
  • the refractive index of the first region 32a will be a value greater than about 1.5 to about 1.8, depending on the concentration of the nanoparticles 36.
  • the refractive index of the second region 32 b has a value smaller than about 1.4 to about 1.5 depending on the concentration of the nanoparticles 36.
  • the refractive index of the plurality of convex portions 33 is about 1.5, when a voltage is applied between the first electrode layer 40 and the second electrode layer 50, the convex portions 33 and the first region 32a In between, a refractive index difference occurs. Therefore, as shown in FIG. 3B, when the light L is incident in an oblique direction, the incident light L is refracted by the side surface 33a of the convex portion 33, and then totally reflected by the side surface 33b. Thereby, the traveling direction of the light L incident obliquely downward is bent by the light distribution control device 1, and the indoor ceiling surface or the like is irradiated. As described above, the light distribution control device 1 is in a light distribution state in which incident light is transmitted by bending its traveling direction.
  • the degree of aggregation of the nanoparticles 36 can be changed according to the magnitude of the applied voltage.
  • the refractive index of the refractive index variable layer 32 changes. For this reason, it is also possible to change the light distribution direction by changing the difference in refractive index between the side surface 33a and the side surface 33b (interface) of the convex portion 33.
  • FIG. 3C is an enlarged cross-sectional view for describing a second application mode (heat shielding state) of the light distribution control device 1 according to the present embodiment.
  • a second voltage is applied between the first electrode layer 40 and the second electrode layer 50.
  • a second voltage having a potential difference of about several tens of volts is applied to the first electrode layer 40 and the second electrode layer 50.
  • a predetermined electric field is applied to the refractive index variable layer 32, so in the refractive index variable layer 32, the charged nanoparticles 36 migrate in the insulating liquid 35 according to the electric field distribution. That is, the nanoparticles 36 electrophorese in the insulating liquid 35.
  • the concentration distribution of the nanoparticles 36 is formed in the variable-refractive-index layer 32 as in the first application mode. At this time, the concentration distribution to be formed is different between the second application mode and the first application mode.
  • the second voltage applied in the second application mode and the first voltage applied in the first application mode have different values.
  • the second voltage is a voltage smaller than the first voltage.
  • the concentration of the nanoparticles 36 in the first region 32a is smaller than in the first application mode shown in FIG. 3B, and the nanoparticles in the second region 32b are The concentration of 36 increases. That is, in the second application mode, the refractive index of the first region 32a is smaller than that of the first application mode, and the refractive index of the second region 32b is larger. Further, in the second application mode, the sizes of the first region 32a and the second region 32b may be different from those in the first application mode.
  • the direction of refraction of light incident on the light distribution control device 1 changes.
  • the incident light L is totally reflected by the interface between the second substrate 20 and the outside (air layer) without being totally reflected by the side surface 33b after being refracted by the side surface 33a.
  • the light distribution control device 1 is returned to the inside.
  • light L is not taken into the room, so it is possible to suppress heat being taken into the room.
  • the light distribution control device 1 is in the heat shielding state in which the heat intake is suppressed by suppressing the light intake.
  • a component of light totally reflected by the side surface 33 b may be included.
  • the amount of light distributed is smaller, and the amount of light totally reflected by the interface between the second substrate 20 and the outside is larger.
  • FIG. 3C shows the case where the second voltage is smaller than the first voltage
  • the opposite may be applied, and the second voltage may be larger than the first voltage.
  • the 2nd voltage in which a thermal insulation state is formed is adjusted suitably, respectively.
  • FIG. 4 is a figure which shows an example at the time of applying the light distribution control device 1 which concerns on this Embodiment to the window of the building 90.
  • the light distribution control device 1 is used by being attached to a window glass 93, and is arranged to take light into the interior of the building 90.
  • FIG. 4 as an example of the building 90, a building whose height from the floor 92 to the ceiling 91 is 2.7 m and whose depth is 9 m is shown.
  • the window glass 93 is provided in a range of 30 cm above the floor to a height of 2.4 m from the ceiling 91.
  • the light distribution control device 1 is provided in the area of the upper half of the window glass 93. At this time, a light distribution control device having characteristics different from the light distribution control device 1 may be provided in the lower half region of the window glass 93. Alternatively, the lower half region may be provided with a device having no light distribution function. Moreover, the light distribution control device 1 may be provided on the entire window glass 93.
  • the light distribution control device 1 causes external light such as sunlight to be totally reflected to travel toward the ceiling 91 to illuminate the indoor ceiling 91 brightly. At this time, the light distribution control device 1 is required to suppress glare felt by the person 94 who is present indoors.
  • the person 94 is present at a distance of 1.6 m from the window glass 93, and shows a standing case and a sitting case.
  • the height of eyes when standing is 1.6 m from floor 92
  • the height of eyes when sitting is 1.2 m from floor 92.
  • FIG. 4 illustrates the standing person 94 and the sitting person 94 in a staggered manner, in the following description, it is assumed that both of them are present at a position 1.6 m away from the window glass 93. It is assumed.
  • the light distribution area 80 and the direct area 81 are schematically shown. Both of the light distribution area 80 and the direct area 81 are represented by the range of the light emission angle ⁇ out with reference to the predetermined part of the light distribution control device 1.
  • the outgoing angle ⁇ out is represented by an angle with respect to the horizontal plane, and the upper side with respect to the horizontal plane is expressed with positive and the lower side with negative.
  • the predetermined part is the lower end of the light distribution control device 1.
  • the light distribution area 80 is an area through which light distributed by the light distribution control device 1 passes.
  • the light distribution region 80 is a range in which the emission angle ⁇ out of light from the lower end of the light distribution control device 1 is 3.6 ° or more and 80 ° or less.
  • the lower limit (in this case, 3.6 °) of the emission angle ⁇ out of the light distribution area 80 is a range in which the light distributed by the light distribution control device 1 does not enter the line of sight of the standing person 94 It is a value corresponding to the boundary.
  • the lower limit value is calculated by tan ⁇ 1 (0.1 / 1.6).
  • the lower limit value of the emission angle ⁇ out is not limited to this, and may be determined so as to allow light to reach the deepest part of the building 90.
  • the lower limit value is the difference from the lower end of the light distribution control device 1 to the ceiling 91 (here, 1.2 m) and the distance from the light distribution control device 1 to the deepest part of the building 90 (here, 9 m) may be calculated.
  • the lower limit value is calculated by tan ⁇ 1 (1.2 / 9), and may be 7.6 °.
  • the direct area 81 is an area through which light that can pass through the light distribution control device 1 and enter the eyes of the person 94 passes. Specifically, the direct area 81 is an area through which light directly entering the eyes of the person 94 from the light distribution control device 1 passes.
  • the direct region 81 is a range in which the emission angle ⁇ out of light from the lower end of the light distribution control device 1 is -43 ° or more and 3.6 ° or less.
  • the upper limit (in this case, 3.6 °) of the outgoing angle ⁇ out of the direct area 81 is the boundary between the range in which the light distributed by the light distribution control device 1 does not enter the line of sight of the standing person 94 Is a value corresponding to That is, the upper limit value of the direct light area 81 corresponds to the lower limit value of the light distribution area 80.
  • the lower limit (here, -43 °) of the outgoing angle ⁇ out of the direct area 81 corresponds to the boundary between the range in which the light transmitted through the light distribution control device 1 does not enter the eye of the sitting person 94 and the range in which it enters. It is a value.
  • the solid line indicating the lower limit is the line of sight of the person 94 sitting with the upper end of the light distribution control device 1. And a line parallel to the broken line connecting
  • the light distribution control device 1 is required not only to simply take a large amount of light toward the ceiling 91 but also to suppress the glare of the person 94 who is indoors. Be done. Moreover, the light distribution control device 1 is required to have transparency in the transparent state, and high heat shielding performance is required in the heat shielding state.
  • the light distribution rate of the light distribution control device 1 which concerns on this Embodiment, a direct rate, a haze, and a solar radiation shielding coefficient are demonstrated.
  • the light distribution rate of the light distribution control device 1 in the light distribution state, is 27% or more.
  • the light distribution rate indicates the ratio of light distributed to light transmitted through the light distribution control device 1.
  • the distributed light is light distributed toward the ceiling 91 as shown in FIG. 4 when the light distribution control device 1 is used for a window.
  • the light to be distributed is light which passes through the light distribution control device 1 and is reflected by the ceiling 91 to illuminate the desk.
  • the light to be distributed is represented by the reflectance on the ceiling 91 and the illuminance on the desk taking into consideration the area ratio between the window and the ceiling 91.
  • the light transmitted through the light distribution control device 1 is attenuated during transmission through each of the light distribution control device 1 and the window to which the light distribution control device 1 is attached among light incident on the light distribution control device 1. It is light.
  • the light which injects into the light distribution control device 1 is sunlight, for example, and is represented by the illumination by external light parallel light.
  • the light distribution rate of the light distribution control device 1 is calculated by the following equation (1).
  • the illuminance on the desk when the light distribution rate is 27% or more is calculated based on the above equation (1).
  • the illuminance of the outside light parallel light is, for example, 80,000 lx assuming that the daytime is fine.
  • permeability of the light distribution control device 1 which concerns on this Embodiment is 0.6, for example.
  • the ceiling reflectance is a reflectance of light emitted to the ceiling, and is, for example, 0.8.
  • the glass transmittance is the transmittance of a common window glass, and is, for example, 0.66.
  • the illuminance on the desk becomes 546 lx or more based on the above equation (1).
  • the illuminance on the desk is 546 lx or more corresponds to the case where the eye-line melanopic equivalent illuminance is 200 lx or more. Since the illuminance required for the work environment is realized only by the light distribution control device 1 when the desktop illuminance is 546 lx or more, indoor lighting may be darkened or may be extinguished. For this reason, energy consumption can be suppressed.
  • the light distribution rate can be 27% or more by setting the inclination angle with respect to the thickness direction of the side surface 33 b functioning as the reflective surface of the convex portion 33 in the range of 0 degrees to 25 degrees. Further, by setting the inclination angle of not only the side surface 33 b but also the side surface 33 a functioning as a refracting surface of the convex portion 33 in the range of 0 degrees to 25 degrees, the light distribution rate can be further enhanced. Furthermore, in the present embodiment, since the electrophoretic material is used as the refractive index variable layer 32, both components of P polarization and S polarization can be distributed, so the light distribution ratio can be further enhanced. . Thereby, the light distribution rate of the light distribution control device 1 can be, for example, 49% or more, and can also be 67% or more.
  • the illuminance on the desk becomes 1000 lx based on the above equation (1), and sufficient brightness can be realized by the collection of sunlight.
  • the desktop illumination intensity is approximately 1366 lx based on the above equation (1). This corresponds to about 2.5 times the light distribution ratio of 27%, and further, sufficient brightness can be realized. Therefore, indoor lighting can be further darkened or can be turned off, and energy consumption can be further suppressed.
  • the direct light rate of the light distribution control device 1 is 10% or less.
  • the direct rate is a ratio of light traveling to the direct area 81 to light incident on the light distribution control device 1.
  • the light traveling to the direct area is represented by the peak illumination in the direct area.
  • the direct rate of the light distribution control device 1 is calculated by the following equation (2).
  • the peak illuminance in the direct area when the direct rate is 10% or less is calculated based on the above equation (2).
  • the illuminance of the outside light parallel light is, for example, 80,000 lx assuming the case of daytime fine weather as in the case of the light distribution rate.
  • the present inventors conducted a test to investigate the relationship between the transmittance and the tolerability of glare using a general window glass.
  • the test was conducted by having a plurality of subjects sitting at a position 2 m from the window glass and answering the questionnaire while looking at the window glass. At this time, a plurality of window glasses having different transmittances were prepared as target window glasses. For each window glass, each of a plurality of subjects was asked in 5 steps (1 to 5) whether or not the glare was acceptable. The lower the numerical value of the answer is, the more unacceptable the glare is, and the higher the numerical value is, the more acceptable is the glare.
  • FIG. 5 is a figure which shows the questionnaire result of whether it felt glare with respect to the transmittance
  • the horizontal axis is the transmittance of the window glass, and the vertical axis indicates whether or not the glare is acceptable.
  • the lower the transmittance of the window glass the smaller the proportion of people who feel glare. From the approximate curve shown by the solid line graph in FIG. 5, when the number of responses to the questionnaire is 3 points, that is, the transmittance when answering "nothing" as to whether or not the glare is acceptable is 10.8. %.
  • the direct light rate is 10% or less, the amount of light entering the eyes of the person 94 in the light distribution state is sufficiently reduced. Can be reduced.
  • the light distribution rate can be 27% or more only by setting the inclination angle with respect to the thickness direction of the side surface 33b functioning as the reflection surface of the convex portion 33 in the range of 0 degrees to 25 degrees. It is possible to reduce the directness rate to 10% or less. Further, by setting the inclination angle of not only the side surface 33 b but also the side surface 33 a functioning as the refracting surface of the convex portion 33 in the range of 0 degrees or more and 25 degrees or less, the directness ratio can be further lowered. Specifically, the direct rate of the light distribution control device 1 may be 3.7% or less.
  • the directness rate of the light distribution control device 1 may be 2.2% or less or 1.3% or less.
  • the numerical value of the answer is 4.5 or more, and it is possible to make almost everyone not feel glare.
  • the haze of the light distribution control device 1 in the transparent state, is 3.8% or less.
  • the haze is a parameter indicating the transparency of the light distribution control device 1. As the haze is smaller, the light distribution control device 1 is more transparent, and as the haze is larger, the light distribution control device 1 looks more cloudy.
  • an electrophoretic material is used as a material forming the refractive index variable layer 32. For this reason, since scattering of light in the refractive index variable layer 32 is suppressed, the haze is reduced. By appropriately adjusting the combination of materials as the insulating liquid 35 and the nanoparticles 36, the haze can be made to be 1.9% or less.
  • the inventors of the present invention conducted a test to investigate the relationship between the haze and the appearance of the window using a general window glass in the same manner as in the case of the glare tolerance.
  • FIG. 6 is a diagram showing the result of a questionnaire on how the window looks with respect to the haze of the window glass.
  • the horizontal axis is the transmittance of the window glass, and the vertical axis shows the appearance of the window. Note that FIG. 6 illustrates the case of looking at the outdoors from inside (square plot) and the case of looking at the indoor from outdoors (plot of triangle).
  • the haze of the window glass decreases, the proportion of those who answered clearly becomes clear increases. From the approximate curve shown by the solid line graph in FIG. 6, the haze is 3.8% when the number of responses to the questionnaire is three, that is, when the window looks “not one”.
  • the haze is 3.8% or less
  • a person who is indoors can use the light distribution control device 1.
  • the view outside can be seen clearly. If the haze of the light distribution control device 1 is 1.9% or less, the view can be seen more clearly.
  • the solar radiation shielding coefficient of the light distribution control device 1 in the heat shielding state, is 0.46 or less.
  • the solar radiation shielding coefficient indicates the heat inflow to the light distribution control device 1 when the heat inflow into the room due to transmission and re-radiation of the transparent plate glass having a thickness of 3 mm is 1.00.
  • the indoor temperature rise can be suppressed.
  • the output of the cooling function of the air conditioner can be reduced or stopped, so energy consumption can be reduced.
  • the solar radiation shielding coefficient can be set to 0.46 or less by setting the inclination angle with respect to the thickness direction of the side surface 33a functioning as the refracting surface of the convex portion 33 in the range of 0 degrees to 25 degrees. . Further, by setting the inclination angle of not only the side surface 33a but also the side surface 33b functioning as a reflection surface of the convex portion 33 in the range of 0 degrees to 25 degrees, the solar radiation shielding coefficient can be further lowered. Alternatively, light absorbing nanoparticles may be dispersed in the insulating liquid 35. By these, the solar radiation shielding coefficient of the light distribution control device 1 can be, for example, 0.35 or less.
  • the indoor temperature rise can be further suppressed.
  • the output of the cooling function of the air conditioner can be further reduced or stopped, so that energy consumption can be reduced.
  • the light distribution control device 1 is used to take in sunlight indoors. Since the position of the sun varies depending on the time zone, the characteristics required for the entire window differ depending on the orientation of the window in which the light distribution control device 1 is installed.
  • FIG. 7 is a view showing an example in which the light distribution control device 1 according to the present embodiment is applied to a south-facing window of a building 90.
  • the case where the building 90 is located in the northern hemisphere and the sun mainly passes the south side will be described as an example.
  • FIG. 7 corresponds to the application to a north facing window.
  • the light distribution control device 1 When applied to the south-facing window, as shown in FIG. 7, the light distribution control device 1 according to the present embodiment is provided in the upper half of the window glass 93, and the lower half of the window glass 93 is A light distribution control device 100 having optical characteristics different from the light distribution control device 1 is provided.
  • the area of the lower half of the window glass 93 can not sufficiently exhibit the light distribution function from the viewpoint of reducing the glare to the person 94. Specifically, as shown in FIG. 7, light can be distributed only from the window glass 93 to a depth of about 3 m. Therefore, the lower light distribution control device 100 may have a low light distribution rate.
  • the direct light rate and the haze of the light distribution control device 100 may be similar to those of the light distribution control device 1. That is, the direct light rate of the light distribution control device 100 may be 10% or less or 3.7% or less. The haze of the light distribution control device 100 may be 3.8% or less or 1.9% or less.
  • FIG. 8 is a view showing an example in which the light distribution control device 1 according to the present embodiment is applied to a west-facing window of a building 90. As shown in FIG.
  • the light distribution control device 1 When applied to the west-facing window, as shown in FIG. 8, the light distribution control device 1 according to the present embodiment is provided in the upper half of the window glass 93, and the light distribution control device 1 is provided in the lower half of the window glass 93. A heat shield control device 101 having no light function is provided.
  • the heat shield control device 101 is a device using, for example, a liquid crystal material or the like, and is a device capable of switching between a light scattering state and a transparent state by an applied voltage. For example, by using a device specialized to the heat shielding function without the light distribution function as the heat shielding control device 101, it is possible to enhance the heat shielding performance of the window glass 93 as a whole.
  • the direct heat rate and the haze of the heat shield control device 101 may be similar to those of the light distribution control device 1. That is, the direct heat rate of the heat shield control device 101 may be 10% or less or 3.7% or less. The haze of the heat shield control device 101 may be 3.8% or less or 1.9% or less.
  • the solar radiation shielding coefficient may be 0.46 or less as the whole window.
  • the solar radiation shielding coefficient as the whole window should just be 0.46 or less.
  • the light distribution control device 1 includes the light transmitting first substrate 10 and the light transmitting second substrate 20 disposed opposite to the first substrate 10.
  • a light distribution layer 30 disposed between the layer 50 and for distributing incident light.
  • the light distribution layer 30 is disposed so as to fill the space between the plurality of convex portions 33 with the uneven structure layer 31 having the plurality of convex portions 33, and a voltage applied between the first electrode layer 40 and the second electrode layer 50.
  • the variable-refractive-index layer 32 whose refractive index changes according to.
  • the light distribution layer 30 can change between the transparent state and the light distribution state in which incident light is bent and travels.
  • the light distribution ratio indicating the ratio of the light distributed to the light transmitted through the light distribution control device 1 is 27% or more.
  • the direct light ratio indicating the ratio of light traveling to the direct light region 81 to the incident light is 10% or less.
  • the haze of the light distribution control device 1 is 3.8% or less.
  • the light distribution control device 1 with high transparency can be implement
  • the light distribution layer 30 can be changed to a heat shielding state which suppresses transmission of incident light by further changing the refractive index of the refractive index variable layer 32.
  • the solar radiation shielding coefficient of the light distribution control device 1 is 0.46 or less.
  • the solar radiation shielding coefficient in a thermal insulation state is small enough, the light distribution control device 1 with high thermal insulation can be implement
  • the light distribution control device 1 when the light distribution control device 1 is in the heat insulating state, for example, since the temperature rise in the room can be suppressed, it is possible to reduce or stop the output of the cooling function of the air conditioning facility. This can reduce energy consumption.
  • the refractive index variable layer 32 includes the insulating liquid 35, and the plurality of charged nanoparticles 36 dispersed in the insulating liquid 35 that have different refractive indexes from the insulating liquid 35.
  • the direction of the light distributed in the light distribution state changes in accordance with the degree of aggregation of the charged nanoparticles 36 dispersed in the insulating liquid 35.
  • the degree of aggregation of the nanoparticles 36 can be easily changed according to the voltage applied between the first electrode layer 40 and the second electrode layer 50. Therefore, the transparent state, the light distribution state and the heat shielding state can be easily changed.
  • either P-polarized light or S-polarized light can be distributed, so the light distribution can be increased.
  • any of P-polarized light and S-polarized light can be refracted, so the amount of light transmitted through the light distribution control device 1 can be reduced. Thereby, the heat shielding performance can be further enhanced.
  • the haze of the light distribution control device 1 may be greater than 3.8%.
  • the solar radiation shielding coefficient of the light distribution control device 1 may be larger than 0.46.
  • at least one of the light distribution rate, the direct light rate, the haze, and the solar radiation shielding coefficient of the light distribution control device 1 may satisfy the above-described characteristics.
  • the light distribution control device 1 may not be able to realize the heat shielding state. That is, the light distribution control device 1 may be able to switch only two states of the transparent state and the light distribution state.
  • the light distribution control device 1 is disposed in the window such that the longitudinal direction of the convex portion 33 is the x-axis direction, but the present invention is not limited thereto.
  • the light distribution control device 1 may be disposed in the window such that the longitudinal direction of the convex portion 33 is the z-axis direction.
  • the plurality of convex portions 33 may be divided into a plurality of portions in the x-axis direction.
  • the plurality of convex portions 33 may be arranged to be dispersed in a matrix or the like. That is, the plurality of convex portions 33 may be arranged in a dotted manner.
  • each of the plurality of convex portions 33 has the same shape.
  • the shapes may be different in the plane.
  • the inclination angles of the side surfaces 33a or 33b of the plurality of protrusions 33 may be different between the upper half and the lower half in the z-axis direction in the light distribution control device 1.
  • the refractive index of the nanoparticles 36 may be lower than the refractive index of the insulating liquid 35.
  • the nanoparticles 36 are positively charged in the above embodiment, the present invention is not limited to this. That is, the nanoparticles 36 may be negatively charged.
  • a direct potential is applied between the first electrode layer 40 and the second electrode layer 50 by applying a positive potential to the first electrode layer 40 and applying a negative potential to the second electrode layer 50. It is good to do.
  • the plurality of nanoparticles 36 may include a plurality of types of nanoparticles having different optical properties. For example, it may include positively charged transparent first nanoparticles and negatively charged opaque (such as black) second nanoparticles.
  • the light distribution control device may be provided with a light shielding function by aggregating and unevenly distributing the second nanoparticles.
  • the present invention is not limited to this.
  • a liquid crystal material may be used as the refractive index variable material.
  • the refractive index of the variable-refractive-index layer changes by utilizing the birefringence of liquid crystal molecules contained in the liquid crystal material.
  • the refractive index of the variable-refractive-index layer changes by changing the alignment of liquid crystal molecules according to the electric field applied to the variable-refractive-index layer. As a result, it is possible to control the transparent state, the light distribution state, and the light distribution direction in the light distribution state.
  • sunlight was illustrated as light which injects into a light distribution control device in said embodiment, it does not restrict to this.
  • the light incident on the light distribution control device may be light emitted by a light emitting device such as a lighting device.
  • the light distribution control device 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 control device can also be used, for example, as a light distribution control member such as a light transmission cover of a lighting fixture.
  • the light distribution control device can also be used as a blind member utilizing scattering of light at the interface of the concavo-convex structure.
  • the present invention can be realized by arbitrarily combining components and functions in each embodiment without departing from the scope of the present invention or embodiments obtained by applying various modifications that those skilled in the art may think to each embodiment.
  • the form is also included in the present invention.

Abstract

A photoalignment control device (1) comprises: a first substrate (10) and a second substrate (20), which are translucent and arranged opposite each other; a first electrode layer (40) and a second electrode layer (50), which are translucent and arranged opposite each other between the first substrate (10) and the second substrate (20); and a photoalignment layer (30) arranged between the first electrode layer (40) and the second electrode layer (50). The photoalignment layer (30) includes: an irregularly-structured layer (31) having a plurality of projections (33); and a variable refractive index layer (32) arranged to fill the spaces between the plurality of projections (33) with the refractive index changing in accordance with a voltage applied between the first electrode layer (40) and the second electrode layer (50). The photoalignment layer is configured to switch between a transparent state and a photoaligned state, in which incident light is bent while traveling, in accordance with a change in the refractive index of the variable refractive index layer (32). When the photoalignment layer (30) is in the photoaligned state, the photoalignment ratio of the photoalignment control device (1) is 27% or greater, and the direct radiation ratio is 10% or less.

Description

配光制御デバイスLight distribution control device
　本発明は、配光制御デバイスに関する。 The present invention relates to a light distribution control device.
　従来、屋外から入射する太陽光などの外光の透過状態を変化させることができる配光制御デバイスが知られている。 BACKGROUND Conventionally, a light distribution control device capable of changing the transmission state of external light such as sunlight incident from the outside has been known.
　例えば、特許文献１には、一対の透明基板と、一対の透明基板の各々に形成された一対の透明電極と、一対の透明電極に挟まれたプリズム層及び液晶層とを有する液晶光学素子が開示されている。当該液晶光学素子は、一対の透明電極に印加される電圧によって液晶層の屈折率を変化させて、プリズムの斜面と液晶層との界面を通過する光の屈折角を変化させる。 For example, Patent Document 1 discloses a liquid crystal optical element having a pair of transparent substrates, a pair of transparent electrodes formed on each of the pair of transparent substrates, and a prism layer and a liquid crystal layer sandwiched between the pair of transparent electrodes. It is disclosed. The liquid crystal optical element changes the refractive index of the liquid crystal layer by a voltage applied to the pair of transparent electrodes, and changes the refraction angle of light passing through the interface between the slope of the prism and the liquid crystal layer.
特開２０１２－１７３５３４号公報JP 2012-173534 A
　しかしながら、上記従来の液晶光学素子は、窓に利用された場合に、曲げられた光によって、屋内に居る人が眩しく感じるという問題がある。 However, when the conventional liquid crystal optical element is used for a window, there is a problem that a person who is indoors may feel dazzling by bent light.
　そこで、本発明は、窓に利用された場合に、屋内を明るくすることができ、かつ、屋内に居る人が感じる眩しさを抑制することができる配光制御デバイスを提供することを目的とする。 Therefore, an object of the present invention is to provide a light distribution control device that can brighten the indoor when used for a window and can suppress glare that a person who is indoors feels. .
　上記目的を達成するため、本発明の一態様に係る配光制御デバイスは、透光性を有する第１基板と、前記第１基板に対向して配置された、透光性を有する第２基板と、前記第１基板と前記第２基板との間に互いに対向して配置された、透光性を有する第１電極層及び第２電極層と、前記第１電極層と前記第２電極層との間に配置され、入射した光を配光する配光層とを備え、前記配光層は、複数の凸部を有する凹凸構造層と、前記複数の凸部間を充填するように配置され、前記第１電極層及び前記第２電極層間に印加される電圧に応じて屈折率が変化する屈折率可変層とを含み、前記配光層は、前記屈折率可変層の屈折率が変化することで、透明状態と、入射光を曲げて進行させる配光状態とが変化可能であり、前記配光層が前記配光状態である場合に、前記配光制御デバイスを透過する光に対する、配光される光の割合を示す配光率は、２７％以上であり、前記配光制御デバイスに入射する光に対する、直射領域に進行する光の割合を示す直射率は、１０％以下である。 In order to achieve the above object, a light distribution control device according to an aspect of the present invention includes a light transmitting first substrate and a light transmitting second substrate disposed opposite to the first substrate. A translucent first electrode layer and a second electrode layer disposed between the first substrate and the second substrate so as to face each other, the first electrode layer and the second electrode layer And a light distribution layer for distributing incident light, wherein the light distribution layer is disposed so as to fill the space between the plurality of projections and the concavo-convex structure layer having the plurality of projections. And a refractive index variable layer whose refractive index changes in accordance with a voltage applied between the first electrode layer and the second electrode layer, and the light distribution layer changes the refractive index of the refractive index variable layer. By doing this, it is possible to change between the transparent state and the light distribution state in which incident light is bent and traveled, and the light distribution layer is in the light distribution state. In some cases, the light distribution ratio indicating the ratio of light distributed to the light transmitted through the light distribution control device is 27% or more, and travels to the direct light region with respect to light incident on the light distribution control device The direct light ratio, which indicates the ratio of light emitted, is 10% or less.
　本発明に係る配光制御デバイスによれば、窓に利用された場合に、屋内を明るくすることができ、かつ、屋内に居る人が感じる眩しさを抑制することができる。 ADVANTAGE OF THE INVENTION According to the light distribution control device which concerns on this invention, when utilized for a window, indoors can be made bright and the glare which the person who is indoors can sense can be suppressed.
図１は、実施の形態に係る配光制御デバイスの断面図である。FIG. 1 is a cross-sectional view of a light distribution control device according to the embodiment. 図２は、実施の形態に係る配光制御デバイスの拡大断面図である。FIG. 2 is an enlarged cross-sectional view of the light distribution control device according to the embodiment. 図３Ａは、実施の形態に係る配光制御デバイスの無印加モード（透明状態）を説明するための拡大断面図である。FIG. 3A is an enlarged sectional view for explaining a non-application mode (transparent state) of the light distribution control device according to the embodiment. 図３Ｂは、実施の形態に係る配光制御デバイスの第１印加モード（配光状態）を説明するための拡大断面図である。FIG. 3B is an enlarged cross-sectional view for explaining a first application mode (light distribution state) of the light distribution control device according to the embodiment. 図３Ｃは、実施の形態に係る配光制御デバイスの第２印加モード（遮熱状態）を説明するための拡大断面図である。FIG. 3C is an enlarged cross-sectional view for describing a second application mode (heat shielding state) of the light distribution control device according to the embodiment. 図４は、実施の形態に係る配光制御デバイスを建物の窓に適用した場合の一例を示す図である。FIG. 4: is a figure which shows an example at the time of applying the light distribution control device which concerns on embodiment to the window of a building. 図５は、窓ガラスの透過率に対して眩しさを感じたか否かのアンケート結果を示す図である。FIG. 5: is a figure which shows the questionnaire result of whether it felt glare with respect to the transmittance | permeability of window glass. 図６は、窓ガラスのヘイズに対して窓の見え方のアンケート結果を示す図である。FIG. 6 is a diagram showing the result of a questionnaire on how the window looks with respect to the haze of the window glass. 図７は、実施の形態に係る配光制御デバイスを建物の南向きの窓へ適用した場合の一例を示す図である。FIG. 7: is a figure which shows an example at the time of applying the light distribution control device which concerns on embodiment to the south window of a building. 図８は、実施の形態に係る配光制御デバイスを建物の西向きの窓へ適用した場合の一例を示す図である。FIG. 8 is a diagram showing an example in which the light distribution control device according to the embodiment is applied to a west-facing window of a building.
　以下では、本発明の実施の形態に係る配光制御デバイスについて、図面を用いて詳細に説明する。なお、以下に説明する実施の形態は、いずれも本発明の一具体例を示すものである。したがって、以下の実施の形態で示される数値、形状、材料、構成要素、構成要素の配置及び接続形態、ステップ、ステップの順序などは、一例であり、本発明を限定する趣旨ではない。よって、以下の実施の形態における構成要素のうち、独立請求項に記載されていない構成要素については、任意の構成要素として説明される。 Hereinafter, the light distribution control device according to the embodiment of the present invention will be described in detail with reference to the drawings. Each embodiment described below shows one specific example of the present invention. Therefore, numerical values, shapes, materials, components, arrangements and connection forms of components, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components not described in the independent claims are described as optional components.
　また、各図は、模式図であり、必ずしも厳密に図示されたものではない。したがって、例えば、各図において縮尺などは必ずしも一致しない。また、各図において、実質的に同一の構成については同一の符号を付しており、重複する説明は省略又は簡略化する。 Further, each drawing is a schematic view, and is not necessarily illustrated exactly. Therefore, for example, the scale and the like do not necessarily match in each figure. Further, in each of the drawings, substantially the same configuration is given the same reference numeral, and overlapping description will be omitted or simplified.
　また、本明細書において、平行又は垂直などの要素間の関係性を示す用語、及び、三角形又は台形などの要素の形状を示す用語、並びに、数値範囲は、厳格な意味のみを表す表現ではなく、実質的に同等な範囲、例えば数％程度の差異をも含むことを意味する表現である。 Further, in the present specification, the term indicating the relationship between elements such as parallel or perpendicular, and the term indicating the shape of an element such as triangle or trapezoid, and the numerical range are not expressions expressing only strict meanings. This expression is meant to include a substantially equivalent range, for example, a difference of about several percent.
　また、本明細書及び図面において、ｘ軸、ｙ軸及びｚ軸は、三次元直交座標系の三軸を示している。各実施の形態では、ｚ軸方向を鉛直方向とし、ｚ軸に垂直な方向（ｘｙ平面に平行な方向）を水平方向としている。なお、ｚ軸の正方向を鉛直上方としている。また、本明細書において、「厚み方向」とは、配光制御デバイスの厚み方向を意味し、第１基板及び第２基板の主面に垂直な方向のことであり、「平面視」とは、第１基板又は第２基板の主面に対して垂直な方向から見たときのことをいう。 Moreover, in the present specification and drawings, the x-axis, the y-axis and the z-axis indicate three axes of the 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 vertically upward. Furthermore, in the present specification, the “thickness direction” means the thickness direction of the light distribution control device, and is a direction perpendicular to the main surfaces of the first substrate and the second substrate, and “plan view” When viewed from the direction perpendicular to the main surface of the first substrate or the second substrate.
　（実施の形態）
　［概要］
　まず、実施の形態に係る配光制御デバイスの概要について、図１及び図２を用いて説明する。 Embodiment
[Overview]
First, an outline of the light distribution control device according to the embodiment will be described with reference to FIGS. 1 and 2.
　図１は、本実施の形態に係る配光制御デバイス１の断面図である。図２は、本実施の形態に係る配光制御デバイス１の拡大断面図であり、図１の一点鎖線で囲まれる領域ＩＩの拡大断面図である。 FIG. 1 is a cross-sectional view of a light distribution control device 1 according to the present embodiment. FIG. 2 is an enlarged cross-sectional view of the light distribution control device 1 according to the present embodiment, and is an enlarged cross-sectional view of a region II surrounded by an alternate long and short dash line in FIG.
　配光制御デバイス１は、配光制御デバイス１に入射する光を制御する光学デバイスである。具体的には、配光制御デバイス１は、配光制御デバイス１に入射する光の進行方向を変更して（つまり、配光して）出射させることができる配光素子である。 The light distribution control device 1 is an optical device that controls light incident on the light distribution control device 1. Specifically, the light distribution control device 1 is a light distribution element capable of changing the traveling direction of light incident on the light distribution control device 1 (that is, distributing light) and emitting the light.
　図１及び図２に示されるように、配光制御デバイス１は、入射する光を透過するように構成されており、第１基板１０と、第２基板２０と、配光層３０と、第１電極層４０と、第２電極層５０とを備える。 As shown in FIGS. 1 and 2, the light distribution control device 1 is configured to transmit incident light, and the first substrate 10, the second substrate 20, the light distribution layer 30, and A first electrode layer 40 and a second electrode layer 50 are provided.
　なお、第１電極層４０の配光層３０側の面には、第１電極層４０と配光層３０の凹凸構造層３１とを密着させるための密着層が設けられていてもよい。密着層は、例えば、透光性の接着シート、又は、一般的にプライマーと称される樹脂材料などである。 An adhesion layer may be provided on the surface of the first electrode layer 40 on the light distribution layer 30 side in order to bring the first electrode layer 40 into close contact with the uneven structure layer 31 of the light distribution layer 30. The adhesion layer is, for example, a translucent adhesive sheet, or a resin material generally referred to as a primer.
　配光制御デバイス１は、対をなす第１基板１０及び第２基板２０の間に、第１電極層４０、配光層３０及び第２電極層５０がこの順で厚み方向に沿って配置された構成である。なお、第１基板１０と第２基板２０との間の距離を保つために、粒子状の複数のスペーサが面内に分散されていてもよく、柱状の構造が形成されてもよい。 In the light distribution control device 1, the first electrode layer 40, the light distribution layer 30, and the second electrode layer 50 are disposed in this order along the thickness direction between the first substrate 10 and the second substrate 20 forming a pair. Configuration. In order to maintain the distance between the first substrate 10 and the second substrate 20, a plurality of particle-like spacers may be dispersed in the plane, or a columnar structure may be formed.
　配光制御デバイス１は、例えば、建物の窓に設置することで、配光機能付き窓として実現することができる。配光制御デバイス１は、例えば、粘着層を介して既存の窓ガラスなどの透明基材に貼り付けられて使用される。あるいは、配光制御デバイス１は、建物の窓そのものとして利用されてもよい。配光制御デバイス１は、例えば、第１基板１０が屋外側で、第２基板２０が屋内側になり、かつ、図２に示される凸部３３の側面３３ｂが下側（床側）で、側面３３ａが上側（天井側）になるように配置されている。 The light distribution control device 1 can be realized as, for example, a window with a light distribution function by being installed in a window of a building. The light distribution control device 1 is used by, for example, being attached to a transparent substrate such as an existing window glass via an adhesive layer. Alternatively, the light distribution control device 1 may be used as a window of a building itself. In the light distribution control device 1, for example, the first substrate 10 is on the outdoor side, the second substrate 20 is on the indoor side, and the side surface 33b of the convex portion 33 shown in FIG. It arrange | positions so that the side 33a may become upper side (ceiling side).
　配光制御デバイス１では、第１電極層４０及び第２電極層５０間に印加される電圧によって、配光層３０の屈折率可変層３２の屈折率が変化する。これにより、凹凸構造層３１と屈折率可変層３２との界面に屈折率の差が生じ、当該界面による光の屈折及び反射（全反射）を利用して光が配光される。印加される電圧の大きさに応じて、透明状態及び配光状態、並びに、配光状態における光の配光方向（進行方向）を変化させることができる。 In the light distribution control device 1, the refractive index of the refractive index variable layer 32 of the light distribution layer 30 is changed by the voltage applied between the first electrode layer 40 and the second electrode layer 50. As a result, a difference in refractive index occurs at the interface between the uneven structure layer 31 and the refractive index variable layer 32, and light is distributed using refraction and reflection (total reflection) of light by the interface. Depending on the magnitude of the applied voltage, it is possible to change the transparent state, the light distribution state, and the light distribution direction (traveling direction) of light in the light distribution state.
　以下、配光制御デバイス１の各構成部材について、図１及び図２を参照して詳細に説明する。 Hereinafter, each component of the light distribution control device 1 will be described in detail with reference to FIGS. 1 and 2.
　［第１基板及び第２基板］
　第１基板１０及び第２基板２０は、透光性を有する基材である。第１基板１０及び第２基板２０としては、例えばガラス基板又は樹脂基板を用いることができる。 [First substrate and second substrate]
The first substrate 10 and the second substrate 20 are substrates having translucency. For example, a glass substrate or a resin substrate can be used as the first substrate 10 and the second substrate 20.
　ガラス基板の材料としては、ソーダガラス、無アルカリガラス又は高屈折率ガラスなどが挙げられる。樹脂基板の材料としては、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）、ポリカーボネート（ＰＣ）、アクリル（ＰＭＭＡ）又はエポキシなどの樹脂材料が挙げられる。ガラス基板は、光透過率が高く、かつ、水分の透過性が低いという利点がある。一方、樹脂基板は、破壊時の飛散が少ないという利点がある。 Examples of the material of 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.
　第１基板１０と第２基板２０とは、同じ材料で構成されていてもよく、あるいは、異なる材料で構成されていてもよい。また、第１基板１０及び第２基板２０は、リジッド基板に限るものではなく、可撓性を有するフレキシブル基板でもよい。本実施の形態において、第１基板１０及び第２基板２０は、ＰＥＴ樹脂からなる透明樹脂基板である。 The first substrate 10 and the second substrate 20 may be made of the same material, or may be made of different materials. Further, the first substrate 10 and the second substrate 20 are not limited to rigid substrates, and may be flexible substrates having flexibility. In the present embodiment, the first substrate 10 and the second substrate 20 are transparent resin substrates made of PET resin.
　第２基板２０は、第１基板１０に対向する対向基板であり、第１基板１０に対向する位置に配置される。第１基板１０と第２基板２０とは、例えば、１μｍ～１０００μｍなどの所定距離を空けて平行に配置されている。第１基板１０と第２基板２０とは、互いの端部外周に額縁状に形成された接着剤などのシール樹脂によって接着されている。 The second substrate 20 is an opposing substrate that faces the first substrate 10, and is disposed at a position that faces the first substrate 10. The first substrate 10 and the second substrate 20 are disposed in parallel at a predetermined distance such as 1 μm to 1000 μm, for example. The first substrate 10 and the second substrate 20 are bonded by a sealing resin such as an adhesive formed in the shape of a frame on the outer periphery of each end.
　なお、第１基板１０及び第２基板２０の平面視形状は、例えば、正方形又は長方形などの矩形状であるが、これに限るものではなく、円形又は四角形以外の多角形であってもよく、任意の形状が採用され得る。 In addition, although the planar view shape of the 1st board | substrate 10 and the 2nd board | substrate 20 is rectangular shapes, such as a square or a rectangle, for example, it does not restrict to this, Polygons other than a circle or a square may be sufficient. Any shape may be employed.
　［配光層］
　図１及び図２に示されるように、配光層３０は、第１電極層４０と第２電極層５０との間に配置される。配光層３０は、透光性を有しており、入射した光を透過させる。また、配光層３０は、入射した光を配光する。つまり、配光層３０は、配光層３０を光が通過する際に、その光の進行方向を変更する。 [Light distribution layer]
As shown in FIGS. 1 and 2, the light distribution layer 30 is disposed between the first electrode layer 40 and the second electrode layer 50. The light distribution layer 30 has translucency, and transmits incident light. In addition, the light distribution layer 30 distributes the incident light. That is, when light passes through the light distribution layer 30, the light distribution layer 30 changes the traveling direction of the light.
　配光層３０は、凹凸構造層３１と、屈折率可変層３２とを有する。本実施の形態では、凹凸構造層３１と屈折率可変層３２との界面で光が反射されることにより、配光制御デバイス１を透過する光の進行方向が曲げられる。 The light distribution layer 30 has a concavo-convex structure layer 31 and a refractive index variable layer 32. In the present embodiment, the light is reflected at the interface between the uneven structure layer 31 and the refractive index variable layer 32, whereby the traveling direction of the light passing through the light distribution control device 1 is bent.
　［凹凸構造層］
　凹凸構造層３１は、屈折率可変層３２の表面（界面）を凹凸にするために設けられた微細形状層である。凹凸構造層３１は、図２に示されるように、複数の凸部３３と、複数の凹部３４とを有する。 [Uneven structure layer]
The uneven structure layer 31 is a fine shape layer provided to make the surface (interface) of the variable-refractive-index layer 32 uneven. The uneven structure layer 31 has a plurality of convex portions 33 and a plurality of concave portions 34, as shown in FIG.
　具体的には、凹凸構造層３１は、マイクロオーダーサイズの複数の凸部３３によって構成された凹凸構造体である。複数の凸部３３の間が、複数の凹部３４である。すなわち、隣り合う２つの凸部３３の間が、１つの凹部３４である。図２に示される例では、複数の凸部３３が個々に分離された例を示しているが、これに限らない。複数の凸部３３は根元（第１電極層４０側）で互いに接続されていてもよい。つまり、複数の凸部３３と第１電極層４０との間に凸部３３の基台となる層（膜）状の基台部が設けられていてもよい。 Specifically, the concavo-convex structure layer 31 is a concavo-convex structure body constituted by a plurality of convex portions 33 of micro order size. A plurality of concave portions 34 are between the plurality of convex portions 33. That is, one concave portion 34 is between two adjacent convex portions 33. Although the example shown in FIG. 2 shows an example in which the plurality of convex portions 33 are individually separated, the present invention is not limited to this. The plurality of convex portions 33 may be connected to each other at the root (the first electrode layer 40 side). That is, a layer (film) -like base portion to be a base of the convex portion 33 may be provided between the plurality of convex portions 33 and the first electrode layer 40.
　複数の凸部３３は、第１基板１０の主面（第１電極層４０が設けられた面）に平行なｚ軸方向に並んで配置された複数の凸部である。すなわち、本実施の形態では、ｚ軸方向は、複数の凸部３３の並び方向である。 The plurality of projections 33 are a plurality of projections arranged in the z-axis direction parallel to the main surface (the surface on which the first electrode layer 40 is provided) of the first substrate 10. That is, in the present embodiment, the z-axis direction is the direction in which the plurality of convex portions 33 are arranged.
　本実施の形態では、複数の凸部３３は、その並び方向に直交する方向に延在する長尺の凸条である。具体的には、複数の凸部３３は、ｘ軸方向に延びたストライプ状に形成されている。複数の凸部３３の各々は、ｘ軸方向に沿って直線状に延びている。例えば、複数の凸部３３の各々は、第１電極層４０に対して横倒しに配置された三角柱である。なお、複数の凸部３３は、ｘ軸方向に沿って蛇行しながら延びていてもよい。例えば、複数の凸部３３は、波線のストライプ状に形成されていてもよい。 In the present embodiment, the plurality of protrusions 33 are long ridges extending in a direction orthogonal to the direction in which the protrusions 33 are arranged. Specifically, the plurality of convex portions 33 are formed in a stripe shape extending in the x-axis direction. Each of the plurality of protrusions 33 extends linearly along the x-axis direction. For example, each of the plurality of protrusions 33 is a triangular prism disposed sideways with respect to the first electrode layer 40. The plurality of convex portions 33 may extend in a meandering manner along the x-axis direction. For example, the plurality of convex portions 33 may be formed in a wavy stripe.
　複数の凸部３３は、例えばｚ軸方向に沿って等間隔に配置されている。複数の凸部３３の各々の形状及び大きさは、互いに同じであるが、異なっていてもよい。 The plurality of convex portions 33 are, for example, arranged at equal intervals along the z-axis direction. The shape and size of each of the plurality of protrusions 33 are the same as one another, but may be different.
　図２に示されるように、複数の凸部３３の各々は、根元から先端にかけて先細る形状を有する。具体的には、複数の凸部３３の各々の断面形状は、第１基板１０から第２基板２０に向かう方向に沿って先細りのテーパ形状である。本実施の形態では、凸部３３のｙｚ断面における断面形状は、配光制御デバイス１の厚み方向に向かって先細る三角形であるが、これに限らない。凸部３３の断面形状は、台形でもよく、その他の多角形、又は、カーブを含む多角形などでもよい。 As shown in FIG. 2, each of the plurality of projections 33 has a tapered shape from the root to the tip. Specifically, the cross-sectional shape of each of the plurality of protrusions 33 is a tapered shape that tapers in the direction from the first substrate 10 toward the second substrate 20. In the present embodiment, the cross-sectional shape of the convex portion 33 in the yz cross section is a triangle that tapers in the thickness direction of the light distribution control device 1, but is not limited to this. The cross-sectional shape of the convex portion 33 may be a trapezoid, another polygon, or a polygon including a curve.
　本実施の形態では、図２に示されるように、複数の凸部３３の各々は、一対の側面３３ａ及び３３ｂを有する。一対の側面３３ａ及び３３ｂは、ｚ軸方向に交差する面である。一対の側面３３ａ及び３３ｂの各々は、ｙ軸方向に対して所定の傾斜角で傾斜する傾斜面である。一対の側面３３ａ及び３３ｂの間隔、すなわち、凸部３３の幅は、第１基板１０から第２基板２０に向かって漸次小さくなっている。 In the present embodiment, as shown in FIG. 2, each of the plurality of convex portions 33 has a pair of side surfaces 33a and 33b. The pair of side surfaces 33a and 33b are surfaces intersecting in the z-axis direction. Each of the pair of side surfaces 33a and 33b is an inclined surface which is inclined at a predetermined inclination angle with respect to the y-axis direction. The distance between the pair of side surfaces 33 a and 33 b, that is, the width of the protrusion 33 gradually decreases from the first substrate 10 toward the second substrate 20.
　側面３３ａは、例えば、ｚ軸が鉛直方向に一致するように配光制御デバイス１を配置した場合に、凸部３３を構成する複数の側面のうち、鉛直下方側の側面である。側面３３ａは、入射光を屈折させる屈折面である。 The side surface 33 a is, for example, a side surface on the vertically lower side among the plurality of side surfaces constituting the convex portion 33 when the light distribution control device 1 is disposed such that the z axis coincides with the vertical direction. The side surface 33a is a refractive surface that refracts incident light.
　側面３３ｂは、例えば、ｚ軸が鉛直方向に一致するように配光制御デバイス１を配置した場合に、凸部３３を構成する複数の側面のうち、鉛直上方側の側面である。側面３３ｂは、入射光を反射させる反射面である。ここでの反射は、全反射であり、側面３３ｂは、全反射面として機能する。 The side surface 33 b is, for example, the side surface on the vertically upper side among the plurality of side surfaces configuring the convex portion 33 when the light distribution control device 1 is disposed such that the z axis coincides with the vertical direction. The side surface 33 b is a reflective surface that reflects incident light. The reflection here is total reflection, and the side surface 33b functions as a total reflection surface.
　複数の凸部３３の幅（ｚ軸方向の長さ）は、例えば１μｍ～２０μｍであり、好ましくは１０μｍ以下であるが、これに限らない。また、隣り合う２つの凸部３３の間隔は、例えば、０μｍ～１００μｍであるが、これに限らない。隣り合う２つの凸部３３は、互いに接触していてもよく、所定の間隔を空けて配置されていてもよい。 The width (length in the z-axis direction) of the plurality of protrusions 33 is, for example, 1 μm to 20 μm, and preferably 10 μm or less, but is not limited thereto. The distance between two adjacent convex portions 33 is, for example, 0 μm to 100 μm, but is not limited to this. Two adjacent convex portions 33 may be in contact with each other, or may be arranged at a predetermined interval.
　凹凸構造層３１の材料としては、例えばアクリル樹脂、エポキシ樹脂又はシリコーン樹脂などの光透過性を有する樹脂材料を用いることができる。凹凸構造層３１は、例えば、紫外線硬化樹脂材料から形成され、モールド成形又はナノインプリントなどによって形成することができる。凹凸構造層３１は、例えば、緑色光に対する屈折率が１．５のアクリル樹脂を用いて断面が三角形の凹凸構造を、モールド型押しにより形成することができる。 As a material of the uneven structure layer 31, for example, a resin material having light transmittance such as an acrylic resin, an epoxy resin, or a silicone resin can be used. The uneven structure layer 31 is formed of, for example, an ultraviolet curable resin material, and can be formed by molding or nanoimprinting. The concavo-convex structure layer 31 can form a concavo-convex structure having a triangular cross section by molding using, for example, an acrylic resin having a refractive index of 1.5 for green light.
　［屈折率可変層］
　屈折率可変層３２は、複数の凸部３３の間（すなわち、凹部３４）を充填するように配置されている。具体的には、屈折率可変層３２は、第１電極層４０と第２電極層５０との間に形成される隙間を埋めるように配置されている。例えば、図２に示されるように、凸部３３と第２電極層５０とが離れているので、屈折率可変層３２は、凹部３４だけでなく、凸部３３の先端部と第２電極層５０との間の隙間を埋めるように配置される。なお、凸部３３と第２電極層５０とは接触していてもよく、この場合、屈折率可変層３２は、凹部３４毎に分離して設けられていてもよい。 [Refractive index variable layer]
The refractive index variable layer 32 is disposed so as to fill the spaces between the plurality of convex portions 33 (that is, the concave portions 34). Specifically, the refractive index variable layer 32 is disposed so as to fill a gap formed between the first electrode layer 40 and the second electrode layer 50. For example, as shown in FIG. 2, since the convex portion 33 and the second electrode layer 50 are separated, the refractive index variable layer 32 is not limited to the concave portion 34, but the tip portion of the convex portion 33 and the second electrode layer It is arranged to fill the gap between 50 and 50. The convex portion 33 and the second electrode layer 50 may be in contact with each other, and in this case, the refractive index variable layer 32 may be provided separately for each concave portion 34.
　屈折率可変層３２は、第１電極層４０及び第２電極層５０間に印加される電圧に応じて屈折率が変化する。具体的には、屈折率可変層３２は、電界が与えられることによって可視光帯域での屈折率が調整可能な屈折率調整層として機能する。電界は、第１電極層４０及び第２電極層５０間に印加される電圧に応じて変化する。例えば、図示しない制御部などによって、第１電極層４０と第２電極層５０との間には直流電圧が印加される。 The refractive index of the variable-refractive-index layer 32 changes in accordance with the voltage applied between the first electrode layer 40 and the second electrode layer 50. Specifically, the refractive index variable layer 32 functions as a refractive index adjustment layer whose refractive index in the visible light band can be adjusted by application of an electric field. The electric field changes in response to the voltage applied between the first electrode layer 40 and the second electrode layer 50. For example, a DC voltage is applied between the first electrode layer 40 and the second electrode layer 50 by a control unit (not shown) or the like.
　図２に示されるように、屈折率可変層３２は、絶縁性液体３５と、絶縁性液体３５に含まれるナノ粒子３６とを有する。屈折率可変層３２は、無数のナノ粒子３６が絶縁性液体３５に分散されたナノ粒子分散層である。 As shown in FIG. 2, the variable-refractive-index layer 32 includes an insulating liquid 35 and nanoparticles 36 contained in the insulating liquid 35. The refractive index variable layer 32 is a nanoparticle dispersion layer in which innumerable nanoparticles 36 are dispersed in the insulating liquid 35.
　絶縁性液体３５は、絶縁性を有する透明な液体であり、分散質としてナノ粒子３６が分散される分散媒となる溶媒である。絶縁性液体３５としては、例えば、屈折率（溶媒屈折率）が約１．３～約１．６の材料を用いることができる。本実施の形態では、屈折率が約１．４の絶縁性液体３５を用いている。 The insulating liquid 35 is a transparent liquid having an insulating property, and is a solvent serving as a dispersion medium in which the nanoparticles 36 are dispersed as a dispersoid. As the insulating liquid 35, for example, a material having a refractive index (solvent refractive index) of about 1.3 to about 1.6 can be used. In the present embodiment, the insulating liquid 35 having a refractive index of about 1.4 is used.
　なお、絶縁性液体３５の動粘度は、１００ｍｍ２／ｓ程度であるとよい。また、絶縁性液体３５は、低誘電率（例えば、凹凸構造層３１の誘電率以下）で、非引火性（例えば、引火点が２５０℃以上の高引火点）及び低揮発性を有してもよい。具体的には、絶縁性液体３５は、脂肪族炭化水素、ナフサ、及びその他の石油系溶剤などの炭化水素、低分子量ハロゲン含有ポリマー、又は、これらの混合物などである。一例として、絶縁性液体３５は、フッ化炭化水素などのハロゲン化炭化水素である。なお、絶縁性液体３５としては、シリコーンオイルなどを用いることもできる。 The kinematic viscosity of the insulating liquid 35 is preferably about 100 mm 2 / s. In addition, the insulating liquid 35 has a low dielectric constant (for example, not more than the dielectric constant of the concavo-convex structure layer 31), a non-flammable property (for example, a high flash point of 250 ° C. or more) and a low volatility. It is also good. Specifically, the insulating liquid 35 is a hydrocarbon such as aliphatic hydrocarbon, naphtha, and other petroleum solvents, a low molecular weight halogen-containing polymer, or a mixture thereof. As an example, the insulating liquid 35 is a halogenated hydrocarbon such as a fluorinated hydrocarbon. As the insulating liquid 35, silicone oil or the like can also be used.
　ナノ粒子３６は、絶縁性液体３５に複数分散されている。ナノ粒子３６は、粒径がナノオーダサイズの微粒子である。具体的には、入射光の波長をλとすると、ナノ粒子３６の粒径は、λ／４以下であるとよい。ナノ粒子３６の粒径をλ／４以下にすることで、ナノ粒子３６による光散乱を少なくして、ナノ粒子３６と絶縁性液体３５との平均的な屈折率を得ることができる。ナノ粒子３６の粒径は、小さい程よく、好ましくは１００ｎｍ以下、より好ましくは、数ｎｍ～数十ｎｍである。 A plurality of nanoparticles 36 are dispersed in the insulating liquid 35. The nanoparticles 36 are fine particles of nano order size. Specifically, when the wavelength of the incident light is λ, the particle diameter of the nanoparticles 36 is preferably λ / 4 or less. By setting the particle diameter of the nanoparticles 36 to λ / 4 or less, light scattering by the nanoparticles 36 can be reduced, and an average refractive index of the nanoparticles 36 and the insulating liquid 35 can be obtained. The particle diameter of the nanoparticles 36 is preferably as small as possible, preferably 100 nm or less, more preferably several nm to several tens nm.
　ナノ粒子３６は、例えば、高屈折率材料によって構成されている。具体的には、ナノ粒子３６の屈折率は、絶縁性液体３５の屈折率よりも高い。本実施の形態において、ナノ粒子３６の屈折率は、凹凸構造層３１の屈折率よりも高い。 The nanoparticles 36 are made of, for example, a high refractive index material. Specifically, the refractive index of the nanoparticles 36 is higher than the refractive index of the insulating liquid 35. In the present embodiment, the refractive index of the nanoparticles 36 is higher than the refractive index of the uneven structure layer 31.
　ナノ粒子３６としては、例えば、金属酸化物微粒子を用いることができる。また、ナノ粒子３６は、透過率が高い材料で構成されていてもよい。本実施の形態では、ナノ粒子３６として、酸化ジルコニウム（ＺｒＯ２）によって構成された屈折率が２．１の透明なジルコニア粒子を用いている。なお、ナノ粒子３６は、酸化ジルコニウムに限らず、酸化チタン（ＴｉＯ２：屈折率２．５）などによって構成されていてもよい。 For example, metal oxide fine particles can be used as the nanoparticles 36. In addition, the nanoparticles 36 may be made of a material having high transmittance. In the present embodiment, transparent zirconia particles having a refractive index of 2.1 and made of zirconium oxide (ZrO 2 ) are used as the nanoparticles 36. The nanoparticles 36 are not limited to zirconium oxide, and may be made of titanium oxide (TiO 2 : refractive index 2.5) or the like.
　また、ナノ粒子３６は、帯電している荷電粒子である。例えば、ナノ粒子３６の表面を修飾することで、ナノ粒子３６を正（プラス）又は負（マイナス）に帯電させることができる。本実施の形態において、ナノ粒子３６は、正（プラス）に帯電している。 Also, the nanoparticles 36 are charged charged particles. For example, by modifying the surface of the nanoparticles 36, the nanoparticles 36 can be positively (plus) or negatively (minus) charged. In the present embodiment, the nanoparticles 36 are positively (plus) charged.
　このように構成された屈折率可変層３２では、帯電したナノ粒子３６が絶縁性液体３５の全体に分散されている。本実施の形態では、一例として、ナノ粒子３６として屈折率が２．１のジルコニア粒子を用いて、溶媒屈折率が約１．４の絶縁性液体３５に分散させたものを屈折率可変層３２としている。 In the variable-refractive-index layer 32 configured in this manner, charged nanoparticles 36 are dispersed in the entire insulating liquid 35. In this embodiment, as an example, zirconia particles having a refractive index of 2.1 as the nanoparticles 36 are dispersed in the insulating liquid 35 having a solvent refractive index of about 1.4 as the refractive index variable layer 32. And
　また、屈折率可変層３２の全体の屈折率（平均屈折率）は、ナノ粒子３６が絶縁性液体３５内に均一に分散された状態において、凹凸構造層３１の屈折率と略同一に設定されており、本実施の形態では、約１．５である。なお、屈折率可変層３２の全体の屈折率は、絶縁性液体３５に分散するナノ粒子３６の濃度（量）を調整することによって変えることができる。詳細は後述するが、ナノ粒子３６の量は、例えば、凹凸構造層３１の凹部３４に埋まる程度である。この場合、絶縁性液体３５に対するナノ粒子３６の濃度は、約１０％～約３０％である。 The refractive index (average refractive index) of the entire refractive index variable layer 32 is set to be substantially the same as the refractive index of the concavo-convex structure layer 31 in a state where the nanoparticles 36 are uniformly dispersed in the insulating liquid 35. In the present embodiment, it is about 1.5. The entire refractive index of the refractive index variable layer 32 can be changed by adjusting the concentration (amount) of the nanoparticles 36 dispersed in the insulating liquid 35. Although the details will be described later, the amount of the nanoparticles 36 is, for example, the extent of being buried in the recess 34 of the uneven structure layer 31. In this case, the concentration of the nanoparticles 36 to the insulating liquid 35 is about 10% to about 30%.
　絶縁性液体３５中に分散するナノ粒子３６は帯電しているので、屈折率可変層３２に電界が与えられると、ナノ粒子３６は、電界分布に従って絶縁性液体３５中を泳動し、絶縁性液体３５内で偏在する。これにより、屈折率可変層３２内のナノ粒子３６の粒子分布が変化して屈折率可変層３２内にナノ粒子３６の濃度分布を持たせることができるので、屈折率可変層３２内の屈折率分布が変化する。つまり、屈折率可変層３２の屈折率が部分的に変化する。このように、屈折率可変層３２は、主に可視光帯域の光に対する屈折率を調整することができる屈折率調整層として機能する。 Since the nanoparticles 36 dispersed in the insulating liquid 35 are charged, when an electric field is applied to the refractive index variable layer 32, the nanoparticles 36 migrate in the insulating liquid 35 according to the electric field distribution, and the insulating liquid It is unevenly distributed within 35. Thereby, the particle distribution of the nanoparticles 36 in the refractive index variable layer 32 can be changed, and the concentration distribution of the nanoparticles 36 can be provided in the refractive index variable layer 32, so that the refractive index in the refractive index variable layer 32 Distribution changes. That is, the refractive index of the refractive index variable layer 32 partially changes. Thus, the refractive index variable layer 32 functions as a refractive index adjustment layer that can mainly adjust the refractive index to light in the visible light band.
　屈折率可変層３２は、例えば、第１電極層４０及び凹凸構造層３１が形成された第１基板１０と、第２電極層５０が形成された第２基板２０との各々の端部外周をシール樹脂で封止した状態で、屈折率可変材料を真空注入法で注入することで形成される。あるいは、屈折率可変層３２は、第１基板１０の第１電極層４０及び凹凸構造層３１上に屈折率可変材料を滴下した後に第２基板２０を貼り合わせることで形成されてもよい。本実施の形態では、屈折率可変材料は、ナノ粒子３６が分散された絶縁性液体３５である。ナノ粒子３６が分散された絶縁性液体３５が第１基板１０と第２基板２０との間に封止されている。 The refractive index variable layer 32 has, for example, the respective outer peripheries of the first substrate 10 on which the first electrode layer 40 and the concavo-convex structure layer 31 are formed, and the second substrate 20 on which the second electrode layer 50 is formed. It forms by inject | pouring refractive index variable material by a vacuum injection method in the state sealed with seal resin. Alternatively, the refractive index variable layer 32 may be formed by dropping the refractive index variable material onto the first electrode layer 40 and the concavo-convex structure layer 31 of the first substrate 10 and then bonding the second substrate 20. In the present embodiment, the refractive index variable material is the insulating liquid 35 in which the nanoparticles 36 are dispersed. An insulating liquid 35 in which the nanoparticles 36 are dispersed is sealed between the first substrate 10 and the second substrate 20.
　屈折率可変層３２の厚さは、例えば１μｍ～１０００μｍであるが、これに限らない。一例として、凹凸構造層３１の凸部３３の高さが１０μｍである場合、屈折率可変層３２の厚さは、例えば４０μｍである。 The thickness of the refractive index variable layer 32 is, for example, 1 μm to 1000 μm, but is not limited thereto. As an example, when the height of the convex portion 33 of the uneven structure layer 31 is 10 μm, the thickness of the refractive index variable layer 32 is, for example, 40 μm.
　［第１電極層及び第２電極層］
　図１及び図２に示されるように、第１電極層４０及び第２電極層５０は、電気的に対となっており、配光層３０に電界を与えることができるように構成されている。第１電極層４０と第２電極層５０とは、電気的だけではなく配置的にも対になっており、第１基板１０と第２基板２０との間に、互いに対向するように配置されている。具体的には、第１電極層４０及び第２電極層５０は、配光層３０を挟むように配置されている。 [First electrode layer and second electrode layer]
As shown in FIGS. 1 and 2, the first electrode layer 40 and the second electrode layer 50 are electrically paired and configured to be able to apply an electric field to the light distribution layer 30. . The first electrode layer 40 and the second electrode layer 50 are not only electrically but also disposed in a pair, and are disposed between the first substrate 10 and the second substrate 20 so as to face each other. ing. Specifically, the first electrode layer 40 and the second electrode layer 50 are disposed to sandwich the light distribution layer 30.
　第１電極層４０及び第２電極層５０は、透光性を有し、入射した光を透過する。第１電極層４０及び第２電極層５０は、例えば透明導電層である。透明導電層の材料としては、ＩＴＯ（Ｉｎｄｉｕｍ　Ｔｉｎ　Ｏｘｉｄｅ）若しくはＩＺＯ（Ｉｎｄｉｕｍ　Ｚｉｎｃ　Ｏｘｉｄｅ）などの透明金属酸化物、銀ナノワイヤ若しくは導電性粒子などの導電体を含有する樹脂からなる導電体含有樹脂、又は、銀薄膜などの金属薄膜などを用いることができる。なお、第１電極層４０及び第２電極層５０は、これらの単層構造でよく、これらの積層構造（例えば透明金属酸化物と金属薄膜との積層構造）でもよい。本実施の形態では、第１電極層４０及び第２電極層５０はそれぞれ、厚さ１００ｎｍのＩＴＯである。 The first electrode layer 40 and the second electrode layer 50 have translucency and transmit incident light. The first electrode layer 40 and the second electrode layer 50 are, for example, transparent conductive layers. The material of the transparent conductive layer is a transparent metal oxide such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), a conductor containing resin made of a resin containing a conductor such as silver nanowire or conductive particles, or And metal thin films such as silver thin films can be used. The first electrode layer 40 and the second electrode layer 50 may have a single-layer structure of these, or a laminated structure of these (for example, a laminated structure of a transparent metal oxide and a metal thin film). In the present embodiment, each of the first electrode layer 40 and the second electrode layer 50 is ITO having a thickness of 100 nm.
　第１電極層４０は、第１基板１０と凹凸構造層３１との間に配置されている。具体的には、第１電極層４０は、第１基板１０の配光層３０側の面に形成されている。 The first electrode layer 40 is disposed between the first substrate 10 and the uneven structure layer 31. Specifically, the first electrode layer 40 is formed on the surface of the first substrate 10 on the light distribution layer 30 side.
　一方、第２電極層５０は、屈折率可変層３２と第２基板２０との間に配置されている。具体的には、第２電極層５０は、第２基板２０の配光層３０側の面に形成されている。 On the other hand, the second electrode layer 50 is disposed between the refractive index variable layer 32 and the second substrate 20. Specifically, the second electrode layer 50 is formed on the surface of the second substrate 20 on the light distribution layer 30 side.
　なお、第１電極層４０及び第２電極層５０は、例えば、外部電源との電気接続が可能となるように構成されている。例えば、外部電源に接続するための電極パッドなどが、第１電極層４０及び第２電極層５０の各々から引き出されて第１基板１０及び第２基板２０に形成されていてもよい。 The first electrode layer 40 and the second electrode layer 50 are configured, for example, to enable electrical connection with an external power supply. For example, an electrode pad or the like for connection to an external power source may be drawn out from each of the first electrode layer 40 and the second electrode layer 50 and formed on the first substrate 10 and the second substrate 20.
　第１電極層４０及び第２電極層５０はそれぞれ、例えば、蒸着、スパッタリングなどにより、ＩＴＯなどの導電膜を成膜することで形成される。 The first electrode layer 40 and the second electrode layer 50 are each formed by depositing a conductive film such as ITO by, for example, vapor deposition or sputtering.
　［配光制御デバイスの動作及び光学状態］
　続いて、配光制御デバイス１の動作及び光学状態について説明する。 [Operation and optical state of light distribution control device]
Subsequently, an operation and an optical state of the light distribution control device 1 will be described.
　＜透明状態（無印加モード）＞
　図３Ａは、本実施の形態に係る配光制御デバイス１の無印加モード（透明状態）を説明するための拡大断面図である。 <Transparent state (non-application mode)>
FIG. 3A is an enlarged cross-sectional view for explaining the non-application mode (transparent state) of the light distribution control device 1 according to the present embodiment.
　図３Ａにおいて、第１電極層４０及び第２電極層５０間には電圧が印加されていない。具体的には、第１電極層４０と第２電極層５０とは、互いに等電位となっている。この場合、屈折率可変層３２には電界が与えられないので、ナノ粒子３６は、絶縁性液体３５の全体に亘って分散された状態となる。 In FIG. 3A, no voltage is applied between the first electrode layer 40 and the second electrode layer 50. Specifically, the first electrode layer 40 and the second electrode layer 50 are at the same potential. In this case, since no electric field is applied to the refractive index variable layer 32, the nanoparticles 36 are dispersed throughout the insulating liquid 35.
　本実施の形態では、ナノ粒子３６が絶縁性液体３５の全体に分散された状態の屈折率可変層３２の屈折率は、上述したように、約１．５である。また、凹凸構造層３１の凸部３３の屈折率は、約１．５である。つまり、屈折率可変層３２の屈折率は、凹凸構造層３１の屈折率と同等になる。したがって、配光層３０の全体で、屈折率が均一になる。 In the present embodiment, the refractive index of the variable-refractive-index layer 32 in the state in which the nanoparticles 36 are dispersed throughout the insulating liquid 35 is about 1.5, as described above. Moreover, the refractive index of the convex part 33 of the uneven structure layer 31 is about 1.5. That is, the refractive index of the refractive index variable layer 32 is equal to the refractive index of the uneven structure layer 31. Therefore, the refractive index is uniform throughout the light distribution layer 30.
　このため、図３Ａに示されるように、斜め方向から光Ｌが入射した場合、屈折率可変層３２と凹凸構造層３１との界面には屈折率差がないので、光が真っ直ぐに進行する。このように、配光制御デバイス１は、入射した光を実質的にそのまま（進行方向を変えることなく）透過させる透明状態になる。 For this reason, as shown in FIG. 3A, when light L is incident from an oblique direction, there is no difference in the refractive index at the interface between the refractive index variable layer 32 and the concavo-convex structure layer 31, so the light travels straight. Thus, the light distribution control device 1 is in a transparent state that transmits incident light substantially as it is (without changing the traveling direction).
　＜配光状態（第１印加モード）＞
　図３Ｂは、本実施の形態に係る配光制御デバイス１の第１印加モード（配光状態）を説明するための拡大断面図である。 <Light distribution state (first application mode)>
FIG. 3B is an enlarged cross-sectional view for describing a first application mode (light distribution state) of the light distribution control device 1 according to the present embodiment.
　図３Ｂにおいて、第１電極層４０及び第２電極層５０間に第１電圧が印加されている。例えば、第１電極層４０と第２電極層５０とには、数十Ｖ程度の電位差の第１電圧が印加されている。これにより、屈折率可変層３２には所定の電界が与えられるので、屈折率可変層３２では、帯電したナノ粒子３６がその電界分布に従って絶縁性液体３５内を泳動する。つまり、ナノ粒子３６は、絶縁性液体３５内を電気泳動する。 In FIG. 3B, a first voltage is applied between the first electrode layer 40 and the second electrode layer 50. For example, the first voltage having a potential difference of about several tens of volts is applied to the first electrode layer 40 and the second electrode layer 50. As a result, a predetermined electric field is applied to the refractive index variable layer 32, so in the refractive index variable layer 32, the charged nanoparticles 36 migrate in the insulating liquid 35 according to the electric field distribution. That is, the nanoparticles 36 electrophorese in the insulating liquid 35.
　図３Ｂに示す例では、第２電極層５０は、第１電極層４０よりも高電位になっている。このため、プラスに帯電したナノ粒子３６は、第１電極層４０に向かって泳動し、凹凸構造層３１の凹部３４に入り込んで集積していく。 In the example illustrated in FIG. 3B, the second electrode layer 50 has a higher potential than the first electrode layer 40. For this reason, the positively charged nanoparticles 36 migrate toward the first electrode layer 40 and enter and accumulate in the recesses 34 of the uneven structure layer 31.
　このように、ナノ粒子３６が屈折率可変層３２内の凹凸構造層３１側に偏在することで、ナノ粒子３６の粒子分布が変化し、屈折率可変層３２内の屈折率分布が一様ではなくなる。具体的には、図３Ｂに示すように、屈折率可変層３２内でナノ粒子３６の濃度分布が形成される。 Thus, when the nanoparticles 36 are localized on the side of the uneven structure layer 31 in the variable-refractive-index layer 32, the particle distribution of the nanoparticles 36 changes, and the refractive index distribution in the variable-refractive-index layer 32 is uniform. It disappears. Specifically, as shown in FIG. 3B, the concentration distribution of the nanoparticles 36 is formed in the refractive index variable layer 32.
　例えば、凹凸構造層３１側の第１領域３２ａでは、ナノ粒子３６の濃度が高くなり、第２電極層５０側の第２領域３２ｂでは、ナノ粒子３６の濃度が低くなる。したがって、第１領域３２ａと第２領域３２ｂとには、屈折率差が生じる。 For example, in the first region 32 a on the uneven structure layer 31 side, the concentration of the nanoparticles 36 is high, and in the second region 32 b on the second electrode layer 50 side, the concentration of the nanoparticles 36 is low. Therefore, a refractive index difference occurs between the first region 32a and the second region 32b.
　本実施の形態では、ナノ粒子３６の屈折率が絶縁性液体３５の屈折率よりも高い。このため、ナノ粒子３６の濃度が高い第１領域３２ａの屈折率は、ナノ粒子３６の濃度が低い、すなわち、絶縁性液体３５の割合が多い第２領域３２ｂの屈折率よりも高くなる。例えば、第１領域３２ａの屈折率は、ナノ粒子３６の濃度に応じて約１．５より大きい値～約１．８になる。第２領域３２ｂの屈折率は、ナノ粒子３６の濃度に応じて約１．４～約１．５より小さい値になる。 In the present embodiment, the refractive index of the nanoparticles 36 is higher than the refractive index of the insulating liquid 35. For this reason, the refractive index of the first region 32a in which the concentration of the nanoparticles 36 is high is higher than the refractive index of the second region 32b in which the concentration of the nanoparticles 36 is low, that is, the proportion of the insulating liquid 35 is high. For example, the refractive index of the first region 32a will be a value greater than about 1.5 to about 1.8, depending on the concentration of the nanoparticles 36. The refractive index of the second region 32 b has a value smaller than about 1.4 to about 1.5 depending on the concentration of the nanoparticles 36.
　複数の凸部３３の屈折率が約１．５であるので、第１電極層４０と第２電極層５０との間に電圧が印加されている場合、凸部３３と第１領域３２ａとの間には、屈折率差が生じる。このため、図３Ｂに示すように、斜め方向から光Ｌが入射した場合、入射した光Ｌは、凸部３３の側面３３ａで屈折した後、側面３３ｂで全反射される。これにより、斜め下方に入射する光Ｌは、配光制御デバイス１によって進行方向が曲げられて、屋内の天井面などに照射される。このように、配光制御デバイス１は、入射した光を、その進行方向を曲げて透過させる配光状態になる。 Since the refractive index of the plurality of convex portions 33 is about 1.5, when a voltage is applied between the first electrode layer 40 and the second electrode layer 50, the convex portions 33 and the first region 32a In between, a refractive index difference occurs. Therefore, as shown in FIG. 3B, when the light L is incident in an oblique direction, the incident light L is refracted by the side surface 33a of the convex portion 33, and then totally reflected by the side surface 33b. Thereby, the traveling direction of the light L incident obliquely downward is bent by the light distribution control device 1, and the indoor ceiling surface or the like is irradiated. As described above, the light distribution control device 1 is in a light distribution state in which incident light is transmitted by bending its traveling direction.
　また、印加する電圧の大きさによってナノ粒子３６の凝集の程度を変化させることができる。ナノ粒子３６の凝集の程度によって屈折率可変層３２の屈折率が変化する。このため、凸部３３の側面３３ａ及び側面３３ｂ（界面）における屈折率の差を変化させることで、配光方向を変化させることも可能である。 In addition, the degree of aggregation of the nanoparticles 36 can be changed according to the magnitude of the applied voltage. Depending on the degree of aggregation of the nanoparticles 36, the refractive index of the refractive index variable layer 32 changes. For this reason, it is also possible to change the light distribution direction by changing the difference in refractive index between the side surface 33a and the side surface 33b (interface) of the convex portion 33.
　＜遮熱状態（第２印加モード）＞
　図３Ｃは、本実施の形態に係る配光制御デバイス１の第２印加モード（遮熱状態）を説明するための拡大断面図である。 <Thermal insulation state (second application mode)>
FIG. 3C is an enlarged cross-sectional view for describing a second application mode (heat shielding state) of the light distribution control device 1 according to the present embodiment.
　図３Ｃにおいて、第１電極層４０及び第２電極層５０間に第２電圧が印加されている。例えば、第１電極層４０と第２電極層５０とには、数十Ｖ程度の電位差の第２電圧が印加されている。これにより、屈折率可変層３２には所定の電界が与えられるので、屈折率可変層３２では、帯電したナノ粒子３６がその電界分布に従って絶縁性液体３５内を泳動する。つまり、ナノ粒子３６は、絶縁性液体３５内を電気泳動する。 In FIG. 3C, a second voltage is applied between the first electrode layer 40 and the second electrode layer 50. For example, a second voltage having a potential difference of about several tens of volts is applied to the first electrode layer 40 and the second electrode layer 50. As a result, a predetermined electric field is applied to the refractive index variable layer 32, so in the refractive index variable layer 32, the charged nanoparticles 36 migrate in the insulating liquid 35 according to the electric field distribution. That is, the nanoparticles 36 electrophorese in the insulating liquid 35.
　第２印加モードでは、第１印加モードと同様に、屈折率可変層３２内でナノ粒子３６の濃度分布が形成される。このとき、第２印加モードと第１印加モードとでは、形成される濃度分布が異なる。 In the second application mode, the concentration distribution of the nanoparticles 36 is formed in the variable-refractive-index layer 32 as in the first application mode. At this time, the concentration distribution to be formed is different between the second application mode and the first application mode.
　具体的には、第２印加モードで印加する第２電圧と、第１印加モードで印加する第１電圧とは異なる値である。例えば、第２電圧は、第１電圧よりも小さい電圧である。このため、図３Ｃに示されるように、第２印加モードでは、図３Ｂに示す第１印加モードに比べて、第１領域３２ａにおけるナノ粒子３６の濃度が小さくなり、第２領域３２ｂにおけるナノ粒子３６の濃度が大きくなる。つまり、第２印加モードでは、第１印加モードに比べて、第１領域３２ａの屈折率が小さくなり、第２領域３２ｂの屈折率が大きくなる。また、第２印加モードでは、第１印加モードに比べて、第１領域３２ａ及び第２領域３２ｂの大きさも異なっていてもよい。 Specifically, the second voltage applied in the second application mode and the first voltage applied in the first application mode have different values. For example, the second voltage is a voltage smaller than the first voltage. For this reason, as shown in FIG. 3C, in the second application mode, the concentration of the nanoparticles 36 in the first region 32a is smaller than in the first application mode shown in FIG. 3B, and the nanoparticles in the second region 32b are The concentration of 36 increases. That is, in the second application mode, the refractive index of the first region 32a is smaller than that of the first application mode, and the refractive index of the second region 32b is larger. Further, in the second application mode, the sizes of the first region 32a and the second region 32b may be different from those in the first application mode.
　これにより、第２印加モードと第１印加モードとでは、配光制御デバイス１に入射する光の屈折される方向が変化する。例えば、図３Ｃに示されるように、入射した光Ｌは、側面３３ａで屈折された後、側面３３ｂで全反射されることなく、第２基板２０と外部（空気層）との界面により全反射され、配光制御デバイス１の内部に戻される。これにより、光Ｌが屋内へ採り込まれないので、屋内に熱が取り入れられるのを抑制することができる。このように、配光制御デバイス１は、光の採り入れを抑えることで熱の取り込みを抑える遮熱状態になる。 As a result, in the second application mode and the first application mode, the direction of refraction of light incident on the light distribution control device 1 changes. For example, as shown in FIG. 3C, the incident light L is totally reflected by the interface between the second substrate 20 and the outside (air layer) without being totally reflected by the side surface 33b after being refracted by the side surface 33a. And the light distribution control device 1 is returned to the inside. As a result, light L is not taken into the room, so it is possible to suppress heat being taken into the room. As described above, the light distribution control device 1 is in the heat shielding state in which the heat intake is suppressed by suppressing the light intake.
　なお、第２印加モードにおいても、第１印加モードと同様に、側面３３ｂによって全反射されて配光される光の成分も含まれてもよい。この場合、第１印加モードの場合に比べて、配光される光の量が少なく、かつ、第２基板２０と外部との界面により全反射される光の量が多くなる。 Also in the second application mode, similarly to the first application mode, a component of light totally reflected by the side surface 33 b may be included. In this case, compared to the case of the first application mode, the amount of light distributed is smaller, and the amount of light totally reflected by the interface between the second substrate 20 and the outside is larger.
　図３Ｃに示す例では、第２電圧が第１電圧より小さい場合を示したが、逆でもよく、第２電圧は、第１電圧より大きくてもよい。凸部３３、絶縁性液体３５及びナノ粒子３６の各々の屈折率、並びに、凸部３３の傾斜面である側面３３ａ及び３３ｂの傾斜角などに応じて、配光状態が形成される第１電圧及び遮熱状態が形成される第２電圧はそれぞれ適宜調整される。 Although the example shown in FIG. 3C shows the case where the second voltage is smaller than the first voltage, the opposite may be applied, and the second voltage may be larger than the first voltage. A first voltage at which a light distribution state is formed according to the refractive index of each of the convex portion 33, the insulating liquid 35 and the nanoparticles 36, and the inclination angle of the side surfaces 33a and 33b which are the inclined surfaces of the convex portion 33. And the 2nd voltage in which a thermal insulation state is formed is adjusted suitably, respectively.
　［光学的な特性］
　続いて、上述したように構成された配光制御デバイス１の光学的な特性について説明する。以下では、まず、配光制御デバイス１の適用例について説明する。 [Optical property]
Subsequently, optical characteristics of the light distribution control device 1 configured as described above will be described. Below, the application example of the light distribution control device 1 is demonstrated first.
　図４は、本実施の形態に係る配光制御デバイス１を建物９０の窓に適用した場合の一例を示す図である。図４に示されるように、配光制御デバイス１は、例えば、窓ガラス９３に貼り付けて使用され、建物９０の屋内に光を採り入れるように配置されている。 FIG. 4: is a figure which shows an example at the time of applying the light distribution control device 1 which concerns on this Embodiment to the window of the building 90. As shown in FIG. As shown in FIG. 4, for example, the light distribution control device 1 is used by being attached to a window glass 93, and is arranged to take light into the interior of the building 90.
　図４では、建物９０の一例として、床９２から天井９１までの高さが２．７ｍ、奥行きが９ｍの建物を示している。窓ガラス９３は、床上３０ｃｍから天井９１までの高さ２．４ｍの範囲に設けられている。 In FIG. 4, as an example of the building 90, a building whose height from the floor 92 to the ceiling 91 is 2.7 m and whose depth is 9 m is shown. The window glass 93 is provided in a range of 30 cm above the floor to a height of 2.4 m from the ceiling 91.
　配光制御デバイス１は、窓ガラス９３の上半分の領域に設けられている。このとき、窓ガラス９３の下半分の領域には、配光制御デバイス１とは異なる特性を有する配光制御デバイスが設けられていてもよい。あるいは、下半分の領域には、配光機能を有しないデバイスが設けられていてもよい。また、配光制御デバイス１は、窓ガラス９３の全体に設けられていてもよい。 The light distribution control device 1 is provided in the area of the upper half of the window glass 93. At this time, a light distribution control device having characteristics different from the light distribution control device 1 may be provided in the lower half region of the window glass 93. Alternatively, the lower half region may be provided with a device having no light distribution function. Moreover, the light distribution control device 1 may be provided on the entire window glass 93.
　配光制御デバイス１は、上述したように、太陽光などの外光を全反射させることにより、天井９１に向けて進行させ、屋内の天井９１を明るく照らす。このとき、配光制御デバイス１には、屋内に居る人９４が感じる眩しさを抑制することが要求させる。 As described above, the light distribution control device 1 causes external light such as sunlight to be totally reflected to travel toward the ceiling 91 to illuminate the indoor ceiling 91 brightly. At this time, the light distribution control device 1 is required to suppress glare felt by the person 94 who is present indoors.
　図４に示す例では、人９４は、窓ガラス９３から１．６ｍ離れた位置に存在し、立っている場合と座っている場合とを示している。ここでは、立っている場合の目線の高さを床９２から１．６ｍとし、座っている場合の目線の高さを床９２から１．２ｍとしている。なお、図４では、立っている人９４と座っている人９４とをずらして図示しているが、以下の説明では、両者共、窓ガラス９３から１．６ｍ離れた位置に存在する場合を想定している。 In the example shown in FIG. 4, the person 94 is present at a distance of 1.6 m from the window glass 93, and shows a standing case and a sitting case. Here, the height of eyes when standing is 1.6 m from floor 92, and the height of eyes when sitting is 1.2 m from floor 92. Although FIG. 4 illustrates the standing person 94 and the sitting person 94 in a staggered manner, in the following description, it is assumed that both of them are present at a position 1.6 m away from the window glass 93. It is assumed.
　図４には、配光領域８０及び直射領域８１を模式的に示している。配光領域８０及び直射領域８１のいずれも、配光制御デバイス１の所定の部位を基準としたときの光の出射角θｏｕｔの範囲で表される。出射角θｏｕｔは、水平面に対する角度で表され、水平面より上側が正、下側が負で表される。図４に示す例では、所定の部位は、配光制御デバイス１の下端である場合を示している。 In FIG. 4, the light distribution area 80 and the direct area 81 are schematically shown. Both of the light distribution area 80 and the direct area 81 are represented by the range of the light emission angle θout with reference to the predetermined part of the light distribution control device 1. The outgoing angle θ out is represented by an angle with respect to the horizontal plane, and the upper side with respect to the horizontal plane is expressed with positive and the lower side with negative. In the example shown in FIG. 4, the predetermined part is the lower end of the light distribution control device 1.
　配光領域８０は、配光制御デバイス１によって配光される光が通過する領域である。例えば、配光領域８０は、配光制御デバイス１の下端からの光の出射角θｏｕｔが３．６°以上８０°以下になる範囲である。 The light distribution area 80 is an area through which light distributed by the light distribution control device 1 passes. For example, the light distribution region 80 is a range in which the emission angle θout of light from the lower end of the light distribution control device 1 is 3.6 ° or more and 80 ° or less.
　配光領域８０の出射角θｏｕｔの下限値（ここでは、３．６°）は、立っている人９４の目線に配光制御デバイス１によって配光された光が入らない範囲と入る範囲との境界に相当する値である。具体的には、下限値は、配光制御デバイス１の下端と立っている人９４の目線との高さの差（ここでは、０．１ｍ（＝１．６ｍ－１．５ｍ））と、配光制御デバイス１から人９４までの距離（ここでは、１．６ｍ）とに基づき算出される。具体的には、下限値は、ｔａｎ－１（０．１／１．６）で算出される。 The lower limit (in this case, 3.6 °) of the emission angle θout of the light distribution area 80 is a range in which the light distributed by the light distribution control device 1 does not enter the line of sight of the standing person 94 It is a value corresponding to the boundary. Specifically, the lower limit value is the difference in height between the lower end of the light distribution control device 1 and the line of sight of the standing person 94 (here, 0.1 m (= 1.6 m-1.5 m)), It is calculated based on the distance from the light distribution control device 1 to the person 94 (here, 1.6 m). Specifically, the lower limit value is calculated by tan −1 (0.1 / 1.6).
　なお、出射角θｏｕｔの下限値は、これに限らず、建物９０の最奥まで光を届かせるように定められてもよい。具体的には、下限値は、配光制御デバイス１の下端から天井９１までの差（ここでは、１．２ｍ）と、配光制御デバイス１から建物９０の最奥までの距離（ここでは、９ｍ）とに基づき算出されてもよい。具体的には、下限値は、ｔａｎ－１（１．２／９）で算出され、７．６°であってもよい。 The lower limit value of the emission angle θout is not limited to this, and may be determined so as to allow light to reach the deepest part of the building 90. Specifically, the lower limit value is the difference from the lower end of the light distribution control device 1 to the ceiling 91 (here, 1.2 m) and the distance from the light distribution control device 1 to the deepest part of the building 90 (here, 9 m) may be calculated. Specifically, the lower limit value is calculated by tan −1 (1.2 / 9), and may be 7.6 °.
　直射領域８１は、配光制御デバイス１を通って人９４の目に入りうる光が通過する領域である。具体的には、直射領域８１は、配光制御デバイス１から人９４の目に直接入る光が通過する領域である。例えば、直射領域８１は、配光制御デバイス１の下端からの光の出射角θｏｕｔが－４３°以上３．６°以下になる範囲である。 The direct area 81 is an area through which light that can pass through the light distribution control device 1 and enter the eyes of the person 94 passes. Specifically, the direct area 81 is an area through which light directly entering the eyes of the person 94 from the light distribution control device 1 passes. For example, the direct region 81 is a range in which the emission angle θout of light from the lower end of the light distribution control device 1 is -43 ° or more and 3.6 ° or less.
　直射領域８１の出射角θｏｕｔの上限値（ここでは、３．６°）は、立っている人９４の目線に配光制御デバイス１によって配光された光が入らない範囲と入る範囲との境界に相当する値である。つまり、直射領域８１の上限値は、配光領域８０の下限値に相当している。 The upper limit (in this case, 3.6 °) of the outgoing angle θout of the direct area 81 is the boundary between the range in which the light distributed by the light distribution control device 1 does not enter the line of sight of the standing person 94 Is a value corresponding to That is, the upper limit value of the direct light area 81 corresponds to the lower limit value of the light distribution area 80.
　直射領域８１の出射角θｏｕｔの下限値（ここでは、－４３°）は、座っている人９４の目線に配光制御デバイス１を透過した光が入らない範囲と入る範囲との境界に相当する値である。具体的には、下限値は、配光制御デバイス１の上端と座っている人９４の目線との高さの差（ここでは、１．５ｍ（＝２．７ｍ－１．２ｍ））と、配光制御デバイス１から座っている人９４までの距離（ここでは、１．６ｍ）とに基づいて算出される。具体的には、下限値は、ｔａｎ－１（１．５／１．６）で算出される。 The lower limit (here, -43 °) of the outgoing angle θout of the direct area 81 corresponds to the boundary between the range in which the light transmitted through the light distribution control device 1 does not enter the eye of the sitting person 94 and the range in which it enters. It is a value. Specifically, the lower limit value is the difference in height between the upper end of the light distribution control device 1 and the line of sight of the sitting person 94 (here, 1.5 m (= 2.7 m-1.2 m)), It is calculated based on the distance from the light distribution control device 1 to the sitting person 94 (here, 1.6 m). Specifically, the lower limit value is calculated by tan −1 (1.5 / 1.6).
　なお、図４で示される直射領域８１は、配光制御デバイス１の下端を基準として図示しているので、下限値を示す実線は、配光制御デバイス１の上端と座っている人９４の目線とを結ぶ破線に平行な線で表されている。 Since the direct area 81 shown in FIG. 4 is illustrated based on the lower end of the light distribution control device 1, the solid line indicating the lower limit is the line of sight of the person 94 sitting with the upper end of the light distribution control device 1. And a line parallel to the broken line connecting
　以上のように、配光制御デバイス１は、配光状態において、ただ単に多くの光を天井９１に向けて採り入れればよいだけでなく、屋内に居る人９４の眩しさを抑制することも要求される。また、配光制御デバイス１は、透明状態においては透明性が要求され、遮熱状態では高い遮熱性能が要求される。 As described above, in the light distribution state, the light distribution control device 1 is required not only to simply take a large amount of light toward the ceiling 91 but also to suppress the glare of the person 94 who is indoors. Be done. Moreover, the light distribution control device 1 is required to have transparency in the transparent state, and high heat shielding performance is required in the heat shielding state.
　以下では、本実施の形態に係る配光制御デバイス１の配光率、直射率、ヘイズ及び日射遮蔽係数について説明する。 Below, the light distribution rate of the light distribution control device 1 which concerns on this Embodiment, a direct rate, a haze, and a solar radiation shielding coefficient are demonstrated.
　本実施の形態では、配光状態では、配光制御デバイス１の配光率が２７％以上である。配光率は、配光制御デバイス１を透過する光に対する、配光される光の割合を示す。 In the present embodiment, in the light distribution state, the light distribution rate of the light distribution control device 1 is 27% or more. The light distribution rate indicates the ratio of light distributed to light transmitted through the light distribution control device 1.
　配光される光は、配光制御デバイス１が窓に利用された場合に、図４に示されるように、天井９１に向けて配光される光である。具体的には、配光される光は、配光制御デバイス１を透過し、かつ、天井９１で反射されて机上を照射する光である。例えば、配光される光は、天井９１の反射率、及び、窓と天井９１との面積比を考慮に入れた机上照度で表される。 The distributed light is light distributed toward the ceiling 91 as shown in FIG. 4 when the light distribution control device 1 is used for a window. Specifically, the light to be distributed is light which passes through the light distribution control device 1 and is reflected by the ceiling 91 to illuminate the desk. For example, the light to be distributed is represented by the reflectance on the ceiling 91 and the illuminance on the desk taking into consideration the area ratio between the window and the ceiling 91.
　配光制御デバイス１を透過する光は、配光制御デバイス１に入射する光のうち、配光制御デバイス１、及び、配光制御デバイス１が取り付けられた窓の各々の透過時に減衰した後の光である。配光制御デバイス１に入射する光は、例えば、太陽光であり、外光平行光による照度で表される。 The light transmitted through the light distribution control device 1 is attenuated during transmission through each of the light distribution control device 1 and the window to which the light distribution control device 1 is attached among light incident on the light distribution control device 1. It is light. The light which injects into the light distribution control device 1 is sunlight, for example, and is represented by the illumination by external light parallel light.
　以上のことから、本実施の形態では、配光制御デバイス１の配光率は、以下の式（１）で算出される。 From the above, in the present embodiment, the light distribution rate of the light distribution control device 1 is calculated by the following equation (1).
　（１）　配光率＝配光される光／透過する光
　　　　　　　　＝机上照度／（外光平行光の照度×デバイス透過率×天井面積比×天井反射率×ガラス透過率） (1) Light distribution rate = light distributed / light transmitted = desk illuminance / (illuminance of external light parallel light × device transmittance × ceiling area ratio × ceiling reflectance × glass transmittance)
　ここで、配光率が２７％以上の場合の机上照度を上記式（１）に基づいて算出する。外光平行光の照度は、昼間の晴天の場合を想定し、例えば８００００ｌｘである。また、本実施の形態に係る配光制御デバイス１の透過率は、例えば０．６である。天井面積比は、天井の面積に対する窓の面積の比率であり、例えば０．０８（＝１．２ｍ／９ｍ）である。天井反射率は、天井に照射された光の反射率であり、例えば０．８である。ガラス透過率は、一般的な窓ガラスの透過率であり、例えば０．６６である。 Here, the illuminance on the desk when the light distribution rate is 27% or more is calculated based on the above equation (1). The illuminance of the outside light parallel light is, for example, 80,000 lx assuming that the daytime is fine. Moreover, the transmittance | permeability of the light distribution control device 1 which concerns on this Embodiment is 0.6, for example. The ceiling area ratio is the ratio of the area of the window to the area of the ceiling, and is, for example, 0.08 (= 1.2 m / 9 m). The ceiling reflectance is a reflectance of light emitted to the ceiling, and is, for example, 0.8. The glass transmittance is the transmittance of a common window glass, and is, for example, 0.66.
　これにより、上記式（１）に基づいて、机上照度が５４６ｌｘ以上になる。机上照度が５４６ｌｘ以上であることは、目線メラノピック等価照度が２００ｌｘ以上である場合に相当する。机上照度が５４６ｌｘ以上であることで、作業環境に必要な照度が配光制御デバイス１のみで実現されるので、屋内の照明を暗くしてもよく、あるいは、消灯してもよい。このため、エネルギーの消費を抑制することができる。 As a result, the illuminance on the desk becomes 546 lx or more based on the above equation (1). When the illuminance on the desk is 546 lx or more corresponds to the case where the eye-line melanopic equivalent illuminance is 200 lx or more. Since the illuminance required for the work environment is realized only by the light distribution control device 1 when the desktop illuminance is 546 lx or more, indoor lighting may be darkened or may be extinguished. For this reason, energy consumption can be suppressed.
　本実施の形態では、凸部３３の反射面として機能する側面３３ｂの厚み方向に対する傾斜角を０度以上２５度以下の範囲にすることで、配光率が２７％以上にすることができる。また、側面３３ｂだけでなく、凸部３３の屈折面として機能する側面３３ａの傾斜角を０度以上２５度以下の範囲にすることで、配光率をさらに高めることができる。さらに、本実施の形態では、屈折率可変層３２として電気泳動材料を用いているので、Ｐ偏光及びＳ偏光のいずれの成分も配光させることができるので、配光率をさらに高めることができる。これにより、配光制御デバイス１の配光率は、例えば４９％以上にすることができ、６７％以上にすることもできる。 In the present embodiment, the light distribution rate can be 27% or more by setting the inclination angle with respect to the thickness direction of the side surface 33 b functioning as the reflective surface of the convex portion 33 in the range of 0 degrees to 25 degrees. Further, by setting the inclination angle of not only the side surface 33 b but also the side surface 33 a functioning as a refracting surface of the convex portion 33 in the range of 0 degrees to 25 degrees, the light distribution rate can be further enhanced. Furthermore, in the present embodiment, since the electrophoretic material is used as the refractive index variable layer 32, both components of P polarization and S polarization can be distributed, so the light distribution ratio can be further enhanced. . Thereby, the light distribution rate of the light distribution control device 1 can be, for example, 49% or more, and can also be 67% or more.
　配光率が４９％以上であれば、上記式（１）に基づいて机上照度が１０００ｌｘになり、太陽光の採光によって十分な明るさを実現することができる。また、配光率が６７％以上であることで、上記式（１）に基づいて机上照度が約１３６６ｌｘになる。これは、配光率が２７％の場合の約２．５倍に相当し、さらに、十分な明るさを実現することができる。このため、屋内の照明をさらに暗くすることができ、あるいは、消灯することができるので、さらにエネルギーの消費を抑制することができる。 When the light distribution rate is 49% or more, the illuminance on the desk becomes 1000 lx based on the above equation (1), and sufficient brightness can be realized by the collection of sunlight. Further, when the light distribution rate is 67% or more, the desktop illumination intensity is approximately 1366 lx based on the above equation (1). This corresponds to about 2.5 times the light distribution ratio of 27%, and further, sufficient brightness can be realized. Therefore, indoor lighting can be further darkened or can be turned off, and energy consumption can be further suppressed.
　また、本実施の形態では、配光状態では、配光制御デバイス１の直射率は、１０％以下である。直射率は、配光制御デバイス１に入射する光に対する、直射領域８１に進行する光の割合である。直射領域に進行する光は、直射領域におけるピーク照度で表される。 Further, in the present embodiment, in the light distribution state, the direct light rate of the light distribution control device 1 is 10% or less. The direct rate is a ratio of light traveling to the direct area 81 to light incident on the light distribution control device 1. The light traveling to the direct area is represented by the peak illumination in the direct area.
　したがって、本実施の形態では、配光制御デバイス１の直射率は、以下の式（２）で算出される。 Therefore, in the present embodiment, the direct rate of the light distribution control device 1 is calculated by the following equation (2).
　（２）　直射率＝直射領域に進行する光／入射する光
　　　　　　　　＝直射領域でのピーク照度／外光平行光の照度 (2) Direct rate = light traveling to the direct area / incident light = peak illuminance at the direct area / illuminance of the parallel light at the external light
　ここで、直射率が１０％以下の場合の、直射領域でのピーク照度を上記式（２）に基づいて算出する。外光平行光の照度は、配光率の場合と同様に、昼間の晴天の場合を想定し、例えば８００００ｌｘである。 Here, the peak illuminance in the direct area when the direct rate is 10% or less is calculated based on the above equation (2). The illuminance of the outside light parallel light is, for example, 80,000 lx assuming the case of daytime fine weather as in the case of the light distribution rate.
　本願発明者らは、一般的な窓ガラスを用いて、透過率と眩しさの許容性との関係を調べるための試験を行った。 The present inventors conducted a test to investigate the relationship between the transmittance and the tolerability of glare using a general window glass.
　試験は、複数の被験者を窓ガラスから２ｍの位置に座らせて、窓ガラスを見ながらアンケートに回答させることで行われた。このとき、対象の窓ガラスとして、透過率の異なる複数の窓ガラスを準備した。複数の被験者の各々に、窓ガラス毎に、眩しさを許容できるか否かを５段階（１～５）で回答させた。回答の数値が低い程、眩しさが許容できないことを意味し、数値が大きい程、眩しさが許容できることを意味する。 The test was conducted by having a plurality of subjects sitting at a position 2 m from the window glass and answering the questionnaire while looking at the window glass. At this time, a plurality of window glasses having different transmittances were prepared as target window glasses. For each window glass, each of a plurality of subjects was asked in 5 steps (1 to 5) whether or not the glare was acceptable. The lower the numerical value of the answer is, the more unacceptable the glare is, and the higher the numerical value is, the more acceptable is the glare.
　図５は、窓ガラスの透過率に対して眩しさを感じたか否かのアンケート結果を示す図である。図５において、横軸は窓ガラスの透過率であり、縦軸は眩しさの許容できるか否かを示している。 FIG. 5: is a figure which shows the questionnaire result of whether it felt glare with respect to the transmittance | permeability of window glass. In FIG. 5, the horizontal axis is the transmittance of the window glass, and the vertical axis indicates whether or not the glare is acceptable.
　図５に示されるように、窓ガラスの透過率が低くなる程、眩しさを感じる人の割合は少なくなる。図５の実線のグラフで示される近似曲線から、アンケートの回答が３点である場合、すなわち、眩しさを許容できるか否かにおいて「どちらでもない」を回答するときの透過率が１０．８％である。 As shown in FIG. 5, the lower the transmittance of the window glass, the smaller the proportion of people who feel glare. From the approximate curve shown by the solid line graph in FIG. 5, when the number of responses to the questionnaire is 3 points, that is, the transmittance when answering "nothing" as to whether or not the glare is acceptable is 10.8. %.
　本実施の形態に係る配光制御デバイス１では、直射率が１０％以下であるので、配光状態において人９４の目に入る光の量が十分に低減されるので、人９４が感じる眩しさを低減することができる。 In the light distribution control device 1 according to the present embodiment, since the direct light rate is 10% or less, the amount of light entering the eyes of the person 94 in the light distribution state is sufficiently reduced. Can be reduced.
　本実施の形態では、凸部３３の反射面として機能する側面３３ｂの厚み方向に対する傾斜角を０度以上２５度以下の範囲にすることで、配光率を２７％以上にすることができるだけでなく、直射率を１０％以下にすることができる。また、側面３３ｂだけでなく、凸部３３の屈折面として機能する側面３３ａの傾斜角を０度以上２５度以下の範囲にすることで、直射率をさらに低くすることができる。具体的には、配光制御デバイス１の直射率は、３．７％以下でもよい。 In the present embodiment, the light distribution rate can be 27% or more only by setting the inclination angle with respect to the thickness direction of the side surface 33b functioning as the reflection surface of the convex portion 33 in the range of 0 degrees to 25 degrees. It is possible to reduce the directness rate to 10% or less. Further, by setting the inclination angle of not only the side surface 33 b but also the side surface 33 a functioning as the refracting surface of the convex portion 33 in the range of 0 degrees or more and 25 degrees or less, the directness ratio can be further lowered. Specifically, the direct rate of the light distribution control device 1 may be 3.7% or less.
　図５に示されるように、直射率が３．７％以下であれば、回答の数値が４以上となって、眩しさを感じる人の割合をより低くすることができる。また、配光制御デバイス１の直射率は、２．２％以下でもよく、１．３％以下でもよい。例えば、直射率が２．２％以下である場合、回答の数値が４．５以上になり、ほぼ全ての人にとって眩しさを感じさせなくすることができる。 As shown in FIG. 5, if the directness rate is 3.7% or less, the numerical value of the answer is 4 or more, and the percentage of people who feel glare can be further lowered. Further, the direct light rate of the light distribution control device 1 may be 2.2% or less or 1.3% or less. For example, when the directness rate is 2.2% or less, the numerical value of the answer is 4.5 or more, and it is possible to make almost everyone not feel glare.
　また、本実施の形態では、透明状態では、配光制御デバイス１のヘイズは、３．８％以下である。ヘイズは、配光制御デバイス１の透明性を示すパラメータである。ヘイズが小さい程、配光制御デバイス１が透明であり、ヘイズが大きい程、配光制御デバイス１が濁って見える。 Further, in the present embodiment, in the transparent state, the haze of the light distribution control device 1 is 3.8% or less. The haze is a parameter indicating the transparency of the light distribution control device 1. As the haze is smaller, the light distribution control device 1 is more transparent, and as the haze is larger, the light distribution control device 1 looks more cloudy.
　本実施の形態では、屈折率可変層３２を構成する材料として、電気泳動材料を用いている。このため、屈折率可変層３２内での光の散乱が抑制されるので、ヘイズが小さくなる。絶縁性液体３５及びナノ粒子３６として、材料の組み合わせを適宜調整することで、ヘイズは、１．９％以下にすることができる。 In the present embodiment, an electrophoretic material is used as a material forming the refractive index variable layer 32. For this reason, since scattering of light in the refractive index variable layer 32 is suppressed, the haze is reduced. By appropriately adjusting the combination of materials as the insulating liquid 35 and the nanoparticles 36, the haze can be made to be 1.9% or less.
　本願発明者らは、一般的な窓ガラスを用いて、眩しさの許容性の場合と同様にして、ヘイズと窓の見え方との関係を調べるための試験を行った。 The inventors of the present invention conducted a test to investigate the relationship between the haze and the appearance of the window using a general window glass in the same manner as in the case of the glare tolerance.
　当該試験では、複数の被験者の各々に、窓ガラス毎に、向こう側がくっきりと（クリアに）見えるかぼけて見えるかを５段階（１～５）で回答させた。回答の数値が低い程、ぼけて見えることを意味し、数値が大きい程、くっきりと見えることを意味する。 In this test, each of a plurality of test subjects was asked in 5 steps (1 to 5) whether the other side clearly (clearly) or looked blurred for each window glass. The lower the number in the answer, the more blurry the image appears, and the higher the number, the clearer the image.
　図６は、窓ガラスのヘイズに対して窓の見え方のアンケート結果を示す図である。図６において、横軸は窓ガラスの透過率であり、縦軸は窓の見え方を示している。なお、図６には、屋内から屋外を見た場合（四角のプロット）と、屋外から屋内を見た場合（三角のプロット）とを図示している。 FIG. 6 is a diagram showing the result of a questionnaire on how the window looks with respect to the haze of the window glass. In FIG. 6, the horizontal axis is the transmittance of the window glass, and the vertical axis shows the appearance of the window. Note that FIG. 6 illustrates the case of looking at the outdoors from inside (square plot) and the case of looking at the indoor from outdoors (plot of triangle).
　図６に示されるように、窓ガラスのヘイズが小さくなる程、くっきり見えると回答した人の割合が多くなる。図６の実線のグラフで示される近似曲線から、アンケートの回答が３点である場合、すなわち、窓の見え方において「どちらでもない」を回答するときのヘイズが３．８％である。 As shown in FIG. 6, as the haze of the window glass decreases, the proportion of those who answered clearly becomes clear increases. From the approximate curve shown by the solid line graph in FIG. 6, the haze is 3.8% when the number of responses to the questionnaire is three, that is, when the window looks “not one”.
　本実施の形態に係る配光制御デバイス１では、ヘイズが３．８％以下であるので、配光制御デバイス１が透明状態である場合、例えば屋内に居る人は、配光制御デバイス１を介して外の景色をクリアに見ることができる。配光制御デバイス１のヘイズが１．９％以下であれば、景色をよりクリアに見ることができる。 In the light distribution control device 1 according to the present embodiment, since the haze is 3.8% or less, when the light distribution control device 1 is in a transparent state, for example, a person who is indoors can use the light distribution control device 1. The view outside can be seen clearly. If the haze of the light distribution control device 1 is 1.9% or less, the view can be seen more clearly.
　また、本実施の形態では、遮熱状態では、配光制御デバイス１の日射遮蔽係数は、０．４６以下である。日射遮蔽係数は、厚さ３ｍｍの透明板ガラスの透過及び再放射による室内への流入熱量を１．００とした場合の、配光制御デバイス１に対する太陽光線の流入熱量を示している。 Moreover, in the present embodiment, in the heat shielding state, the solar radiation shielding coefficient of the light distribution control device 1 is 0.46 or less. The solar radiation shielding coefficient indicates the heat inflow to the light distribution control device 1 when the heat inflow into the room due to transmission and re-radiation of the transparent plate glass having a thickness of 3 mm is 1.00.
　日射遮蔽係数が０．４６以下であれば、屋内の温度上昇を抑えることができる。これにより、例えば、空調設備の冷房機能の出力を低下、又は、停止させることができるので、エネルギー消費を低減することができる。 If the solar radiation shielding coefficient is 0.46 or less, the indoor temperature rise can be suppressed. As a result, for example, the output of the cooling function of the air conditioner can be reduced or stopped, so energy consumption can be reduced.
　本実施の形態では、凸部３３の屈折面として機能する側面３３ａの厚み方向に対する傾斜角を０度以上２５度以下の範囲にすることで、日射遮蔽係数を０．４６以下にすることができる。また、側面３３ａだけでなく、凸部３３の反射面として機能する側面３３ｂの傾斜角を０度以上２５度以下の範囲にすることで、日射遮蔽係数をさらに低くすることができる。あるいは、光を吸収するナノ粒子を絶縁性液体３５に分散させてもよい。これらにより、配光制御デバイス１の日射遮蔽係数は、例えば０．３５以下にすることができる。 In the present embodiment, the solar radiation shielding coefficient can be set to 0.46 or less by setting the inclination angle with respect to the thickness direction of the side surface 33a functioning as the refracting surface of the convex portion 33 in the range of 0 degrees to 25 degrees. . Further, by setting the inclination angle of not only the side surface 33a but also the side surface 33b functioning as a reflection surface of the convex portion 33 in the range of 0 degrees to 25 degrees, the solar radiation shielding coefficient can be further lowered. Alternatively, light absorbing nanoparticles may be dispersed in the insulating liquid 35. By these, the solar radiation shielding coefficient of the light distribution control device 1 can be, for example, 0.35 or less.
　日射遮蔽係数が０．３５以下であれば、より屋内の温度上昇を抑えることができる。これにより、例えば、空調設備の冷房機能の出力をさらに低下、又は、停止させることができるので、エネルギー消費を低減することができる。 If the solar radiation shielding coefficient is 0.35 or less, the indoor temperature rise can be further suppressed. As a result, for example, the output of the cooling function of the air conditioner can be further reduced or stopped, so that energy consumption can be reduced.
　［実施例］
　配光制御デバイス１は、太陽光を屋内へ採り入れるために利用される。太陽は、時間帯によって位置が異なるため、配光制御デバイス１が設置される窓の向きに応じて、窓全体に対して要求される特性が異なる。 [Example]
The light distribution control device 1 is used to take in sunlight indoors. Since the position of the sun varies depending on the time zone, the characteristics required for the entire window differ depending on the orientation of the window in which the light distribution control device 1 is installed.
　図７は、本実施の形態に係る配光制御デバイス１を建物９０の南向きの窓へ適用した場合の一例を示す図である。なお、ここでは、建物９０が北半球に位置し、太陽が主に南側を通過する場合を例に説明する。建物９０が北半球に位置する場合、図７は北向きの窓への適用した場合に相当する。 FIG. 7 is a view showing an example in which the light distribution control device 1 according to the present embodiment is applied to a south-facing window of a building 90. As shown in FIG. Here, the case where the building 90 is located in the northern hemisphere and the sun mainly passes the south side will be described as an example. When the building 90 is located in the northern hemisphere, FIG. 7 corresponds to the application to a north facing window.
　南向きの窓へ適用した場合、図７に示されるように、窓ガラス９３の上半分には、本実施の形態に係る配光制御デバイス１が設けられ、窓ガラス９３の下半分には、配光制御デバイス１とは異なる光学特性を有する配光制御デバイス１００が設けられる。 When applied to the south-facing window, as shown in FIG. 7, the light distribution control device 1 according to the present embodiment is provided in the upper half of the window glass 93, and the lower half of the window glass 93 is A light distribution control device 100 having optical characteristics different from the light distribution control device 1 is provided.
　窓ガラス９３の下半分の領域は、人９４への眩しさを低減する観点から、配光機能を十分に発揮させることができない。具体的には、図７に示されるように、窓ガラス９３から奥行き３ｍ付近にまでしか配光させることができない。このため、下側の配光制御デバイス１００は、配光率が低くてもよい。 The area of the lower half of the window glass 93 can not sufficiently exhibit the light distribution function from the viewpoint of reducing the glare to the person 94. Specifically, as shown in FIG. 7, light can be distributed only from the window glass 93 to a depth of about 3 m. Therefore, the lower light distribution control device 100 may have a low light distribution rate.
　なお、配光制御デバイス１００の直射率及びヘイズは、配光制御デバイス１と同様であってもよい。すなわち、配光制御デバイス１００の直射率は、１０％以下でもよく、３．７％以下でもよい。配光制御デバイス１００のヘイズは、３．８％以下でもよく、１．９％以下でもよい。 The direct light rate and the haze of the light distribution control device 100 may be similar to those of the light distribution control device 1. That is, the direct light rate of the light distribution control device 100 may be 10% or less or 3.7% or less. The haze of the light distribution control device 100 may be 3.8% or less or 1.9% or less.
　図８は、本実施の形態に係る配光制御デバイス１を建物９０の西向きの窓へ適用した場合の一例を示す図である。 FIG. 8 is a view showing an example in which the light distribution control device 1 according to the present embodiment is applied to a west-facing window of a building 90. As shown in FIG.
　西向きの窓へ適用した場合、図８に示されるように、窓ガラス９３の上半分には、本実施の形態に係る配光制御デバイス１が設けられ、窓ガラス９３の下半分には、配光機能を有しない遮熱制御デバイス１０１が設けられる。 When applied to the west-facing window, as shown in FIG. 8, the light distribution control device 1 according to the present embodiment is provided in the upper half of the window glass 93, and the light distribution control device 1 is provided in the lower half of the window glass 93. A heat shield control device 101 having no light function is provided.
　遮熱制御デバイス１０１は、例えば、液晶材料などを利用したデバイスであり、印加する電圧によって、光散乱状態と透明状態とを切り替えることができるデバイスである。例えば、配光機能を有さず、遮熱機能に特化したデバイスを遮熱制御デバイス１０１として利用することで、窓ガラス９３の全体としての遮熱性能を高めることができる。 The heat shield control device 101 is a device using, for example, a liquid crystal material or the like, and is a device capable of switching between a light scattering state and a transparent state by an applied voltage. For example, by using a device specialized to the heat shielding function without the light distribution function as the heat shielding control device 101, it is possible to enhance the heat shielding performance of the window glass 93 as a whole.
　なお、遮熱制御デバイス１０１の直射率及びヘイズは、配光制御デバイス１と同様であってもよい。すなわち、遮熱制御デバイス１０１の直射率は、１０％以下でもよく、３．７％以下でもよい。遮熱制御デバイス１０１のヘイズは、３．８％以下でもよく、１．９％以下でもよい。 Note that the direct heat rate and the haze of the heat shield control device 101 may be similar to those of the light distribution control device 1. That is, the direct heat rate of the heat shield control device 101 may be 10% or less or 3.7% or less. The haze of the heat shield control device 101 may be 3.8% or less or 1.9% or less.
　また、図７及び図８において、日射遮蔽係数は、窓全体として０．４６以下であってもよい。例えば、窓ガラス９３の下半分に別の光学デバイスが配置されている場合に、配光制御デバイス１の日射遮蔽係数が０．４６より大きくても、配光制御デバイス１００又は遮熱制御デバイス１０１と合わせて窓全体としての日射遮蔽係数が０．４６以下であればよい。 Moreover, in FIG.7 and FIG.8, the solar radiation shielding coefficient may be 0.46 or less as the whole window. For example, when another optical device is disposed in the lower half of the window glass 93, the light distribution control device 100 or the heat shield control device 101 even if the solar radiation shielding coefficient of the light distribution control device 1 is larger than 0.46. In addition, the solar radiation shielding coefficient as the whole window should just be 0.46 or less.
　［効果など］
　以上のように、本実施の形態に係る配光制御デバイス１は、透光性を有する第１基板１０と、第１基板１０に対向して配置された、透光性を有する第２基板２０と、第１基板１０と第２基板２０との間に互いに対向して配置された、透光性を有する第１電極層４０及び第２電極層５０と、第１電極層４０と第２電極層５０との間に配置され、入射した光を配光する配光層３０とを備える。配光層３０は、複数の凸部３３を有する凹凸構造層３１と、複数の凸部３３間を充填するように配置され、第１電極層４０及び第２電極層５０間に印加される電圧に応じて屈折率が変化する屈折率可変層３２とを含む。配光層３０は、屈折率可変層３２の屈折率が変化することで、透明状態と、入射光を曲げて進行させる配光状態とが変化可能である。配光層３０が配光状態である場合に、配光制御デバイス１を透過する光に対する、配光される光の割合を示す配光率は、２７％以上であり、配光制御デバイス１に入射する光に対する、直射領域８１に進行する光の割合を示す直射率は、１０％以下である。 [Effect, etc.]
As described above, the light distribution control device 1 according to the present embodiment includes the light transmitting first substrate 10 and the light transmitting second substrate 20 disposed opposite to the first substrate 10. A translucent first electrode layer 40 and a second electrode layer 50, and a first electrode layer 40 and a second electrode disposed opposite to each other between the first substrate 10 and the second substrate 20; And a light distribution layer 30 disposed between the layer 50 and for distributing incident light. The light distribution layer 30 is disposed so as to fill the space between the plurality of convex portions 33 with the uneven structure layer 31 having the plurality of convex portions 33, and a voltage applied between the first electrode layer 40 and the second electrode layer 50. And the variable-refractive-index layer 32 whose refractive index changes according to. By changing the refractive index of the variable-refractive-index layer 32, the light distribution layer 30 can change between the transparent state and the light distribution state in which incident light is bent and travels. When the light distribution layer 30 is in the light distribution state, the light distribution ratio indicating the ratio of the light distributed to the light transmitted through the light distribution control device 1 is 27% or more. The direct light ratio indicating the ratio of light traveling to the direct light region 81 to the incident light is 10% or less.
　これにより、窓に利用された場合に、屋内を明るくすることができ、かつ、屋内に居る人が感じる眩しさを抑制することができる。 Thereby, when it is used for a window, indoors can be made bright and glare that a person who is indoors can feel can be suppressed.
　また、例えば、配光層３０が透明状態である場合に、配光制御デバイス１のヘイズは、３．８％以下である。 Also, for example, when the light distribution layer 30 is in a transparent state, the haze of the light distribution control device 1 is 3.8% or less.
　これにより、透明状態におけるヘイズが十分に小さいので、透明性が高い配光制御デバイス１を実現することができる。このため、配光制御デバイス１が透明状態である場合、例えば屋内に居る人は、配光制御デバイス１を介して外の景色をクリアに見ることができる。 Thereby, since the haze in a transparent state is small enough, the light distribution control device 1 with high transparency can be implement | achieved. Therefore, when the light distribution control device 1 is in a transparent state, for example, a person who is indoors can clearly see the outside scenery through the light distribution control device 1.
　また、例えば、配光層３０は、さらに、屈折率可変層３２の屈折率が変化することで、入射光の透過を抑制する遮熱状態に変化可能である。配光層３０が遮熱状態である場合に、配光制御デバイス１の日射遮蔽係数は、０．４６以下である。 Further, for example, the light distribution layer 30 can be changed to a heat shielding state which suppresses transmission of incident light by further changing the refractive index of the refractive index variable layer 32. When the light distribution layer 30 is in the heat shielding state, the solar radiation shielding coefficient of the light distribution control device 1 is 0.46 or less.
　これにより、遮熱状態における日射遮蔽係数が十分に小さいので、遮熱性が高い配光制御デバイス１を実現することができる。このため、配光制御デバイス１が遮熱状態である場合、例えば、屋内の温度上昇を抑えることができるので、空調設備の冷房機能の出力を低下、又は、停止させることができる。これにより、エネルギー消費を低減することができる。 Thereby, since the solar radiation shielding coefficient in a thermal insulation state is small enough, the light distribution control device 1 with high thermal insulation can be implement | achieved. For this reason, when the light distribution control device 1 is in the heat insulating state, for example, since the temperature rise in the room can be suppressed, it is possible to reduce or stop the output of the cooling function of the air conditioning facility. This can reduce energy consumption.
　また、例えば、屈折率可変層３２は、絶縁性液体３５と、絶縁性液体３５とは屈折率が異なる、絶縁性液体３５に分散された帯電する複数のナノ粒子３６とを備える。 In addition, for example, the refractive index variable layer 32 includes the insulating liquid 35, and the plurality of charged nanoparticles 36 dispersed in the insulating liquid 35 that have different refractive indexes from the insulating liquid 35.
　これにより、絶縁性液体３５に分散された帯電するナノ粒子３６の凝集の程度に応じて、配光状態において配光される光の方向が変化する。ナノ粒子３６の凝集の程度は、第１電極層４０及び第２電極層５０間に印加される電圧に応じて容易に変更することができる。したがって、透明状態、配光状態及び遮熱状態を容易に変更することができる。 Thereby, the direction of the light distributed in the light distribution state changes in accordance with the degree of aggregation of the charged nanoparticles 36 dispersed in the insulating liquid 35. The degree of aggregation of the nanoparticles 36 can be easily changed according to the voltage applied between the first electrode layer 40 and the second electrode layer 50. Therefore, the transparent state, the light distribution state and the heat shielding state can be easily changed.
　また、配光状態においては、Ｐ偏光及びＳ偏光のいずれの光を配光させることができるので、配光量を増やすことができる。また、遮熱状態においても同様に、Ｐ偏光及びＳ偏光のいずれの光も屈折させることができるので、配光制御デバイス１を透過する光の量を少なくすることができる。これにより、遮熱性能をさらに高めることができる。 Further, in the light distribution state, either P-polarized light or S-polarized light can be distributed, so the light distribution can be increased. Further, also in the heat insulating state, any of P-polarized light and S-polarized light can be refracted, so the amount of light transmitted through the light distribution control device 1 can be reduced. Thereby, the heat shielding performance can be further enhanced.
　（その他）
　以上、本発明に係る配光制御デバイスについて、上記の実施の形態に基づいて説明したが、本発明は、上記の実施の形態に限定されるものではない。 (Others)
As mentioned above, although the light distribution control device concerning the present invention was explained based on the above-mentioned embodiment, the present invention is not limited to the above-mentioned embodiment.
　例えば、上記の実施の形態では、配光制御デバイス１のヘイズは、３．８％より大きくてもよい。また、配光制御デバイス１の日射遮蔽係数は、０．４６より大きくてもよい。また、配光制御デバイス１の配光率、直射率、ヘイズ及び日射遮蔽係数のうち少なくとも１つが上述した特性を満たしていてもよい。 For example, in the above embodiment, the haze of the light distribution control device 1 may be greater than 3.8%. Moreover, the solar radiation shielding coefficient of the light distribution control device 1 may be larger than 0.46. In addition, at least one of the light distribution rate, the direct light rate, the haze, and the solar radiation shielding coefficient of the light distribution control device 1 may satisfy the above-described characteristics.
　また、例えば、上記の実施の形態では、配光制御デバイス１は、遮熱状態を実現できなくてもよい。すなわち、配光制御デバイス１は、透明状態と配光状態との２つの状態のみを切り替えることができてもよい。 Also, for example, in the above embodiment, the light distribution control device 1 may not be able to realize the heat shielding state. That is, the light distribution control device 1 may be able to switch only two states of the transparent state and the light distribution state.
　また、例えば、上記の実施の形態では、凸部３３の長手方向がｘ軸方向となるように配光制御デバイス１を窓に配置したが、これに限らない。例えば、凸部３３の長手方向がｚ軸方向となるように、配光制御デバイス１を窓に配置してもよい。 Further, for example, in the above embodiment, the light distribution control device 1 is disposed in the window such that the longitudinal direction of the convex portion 33 is the x-axis direction, but the present invention is not limited thereto. For example, the light distribution control device 1 may be disposed in the window such that the longitudinal direction of the convex portion 33 is the z-axis direction.
　また、例えば、複数の凸部３３は、ｘ軸方向において複数に分割されていてもよい。例えば、複数の凸部３３は、マトリクス状などに点在するように配置されていてもよい。つまり、複数の凸部３３を、ドット状に点在するように配置してもよい。 Also, for example, the plurality of convex portions 33 may be divided into a plurality of portions in the x-axis direction. For example, the plurality of convex portions 33 may be arranged to be dispersed in a matrix or the like. That is, the plurality of convex portions 33 may be arranged in a dotted manner.
　また、例えば、上記の実施の形態では、複数の凸部３３の各々は、同じ形状としたが、これに限るものではなく、例えば、面内において異なる形状であってもよい。例えば、配光制御デバイス１におけるｚ軸方向の上半分と下半分とで複数の凸部３３の側面３３ａ又は３３ｂの傾斜角を異ならせてもよい。 Further, for example, in the above-described embodiment, each of the plurality of convex portions 33 has the same shape. However, the present invention is not limited to this. For example, the shapes may be different in the plane. For example, the inclination angles of the side surfaces 33a or 33b of the plurality of protrusions 33 may be different between the upper half and the lower half in the z-axis direction in the light distribution control device 1.
　また、例えば、上記の実施の形態において、ナノ粒子３６の屈折率が絶縁性液体３５の屈折率より低くてもよい。ナノ粒子３６の屈折率などに応じて印加する電圧を適宜調整することで、透明状態及び配光状態を実現することができる。 Also, for example, in the above embodiment, the refractive index of the nanoparticles 36 may be lower than the refractive index of the insulating liquid 35. By appropriately adjusting the voltage to be applied according to the refractive index of the nanoparticles 36, the transparent state and the light distribution state can be realized.
　また、例えば、上記の実施の形態において、ナノ粒子３６はプラスに帯電させたが、これに限らない。つまり、ナノ粒子３６をマイナスに帯電させてもよい。この場合、第１電極層４０にはプラス電位を印加し、第２電極層５０にはマイナス電位を印加することで、第１電極層４０と第２電極層５０との間に直流電圧を印加するとよい。 Also, for example, although the nanoparticles 36 are positively charged in the above embodiment, the present invention is not limited to this. That is, the nanoparticles 36 may be negatively charged. In this case, a direct potential is applied between the first electrode layer 40 and the second electrode layer 50 by applying a positive potential to the first electrode layer 40 and applying a negative potential to the second electrode layer 50. It is good to do.
　また、複数のナノ粒子３６には、光学特性の異なる複数種類のナノ粒子が含まれてもよい。例えば、プラスに帯電させた透明の第１ナノ粒子と、マイナスに帯電させた不透明（黒色など）の第２ナノ粒子とを含んでもよい。例えば、第２ナノ粒子を凝集させて偏在させることで、配光制御デバイスに遮光機能を持たせてもよい。 The plurality of nanoparticles 36 may include a plurality of types of nanoparticles having different optical properties. For example, it may include positively charged transparent first nanoparticles and negatively charged opaque (such as black) second nanoparticles. For example, the light distribution control device may be provided with a light shielding function by aggregating and unevenly distributing the second nanoparticles.
　また、例えば、上記実施の形態では、屈折率可変材料として電気泳動材料を利用する例について示したが、これに限らない。例えば、屈折率可変材料として、液晶材料を利用してもよい。この場合、液晶材料に含まれる液晶分子の複屈折性を利用して、屈折率可変層の屈折率が変化する。屈折率可変層に与えられる電界に応じて液晶分子の配向を変化させることにより、屈折率可変層の屈折率が変化する。これにより、透明状態及び配光状態、並びに、配光状態における配光方向を制御することができる。 Further, for example, in the above embodiment, although an example of using an electrophoretic material as a refractive index variable material is shown, the present invention is not limited to this. For example, a liquid crystal material may be used as the refractive index variable material. In this case, the refractive index of the variable-refractive-index layer changes by utilizing the birefringence of liquid crystal molecules contained in the liquid crystal material. The refractive index of the variable-refractive-index layer changes by changing the alignment of liquid crystal molecules according to the electric field applied to the variable-refractive-index layer. As a result, it is possible to control the transparent state, the light distribution state, and the light distribution direction in the light distribution state.
　また、上記の実施の形態では、配光制御デバイスに入射する光として太陽光を例示したが、これに限らない。例えば、配光制御デバイスに入射する光は、照明装置などの発光装置が発する光であってもよい。 Moreover, although sunlight was illustrated as light which injects into a light distribution control device in said embodiment, it does not restrict to this. For example, the light incident on the light distribution control device may be light emitted by a light emitting device such as a lighting device.
　また、例えば、配光制御デバイスは、建物の窓に設置する場合に限るものではなく、例えば車の窓などに設置してもよい。また、配光制御デバイスは、例えば、照明器具の透光カバーなどの配光制御部材などに利用することもできる。あるいは、配光制御デバイスは、凹凸構造の界面での光の散乱を利用した目隠し部材としても利用することができる。 Further, for example, the light distribution control device 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 control device can also be used, for example, as a light distribution control member such as a light transmission cover of a lighting fixture. Alternatively, the light distribution control device can also be used as a blind member utilizing scattering of light at the interface of the concavo-convex structure.
　その他、各実施の形態に対して当業者が思いつく各種変形を施して得られる形態や、本発明の趣旨を逸脱しない範囲で各実施の形態における構成要素及び機能を任意に組み合わせることで実現される形態も本発明に含まれる。 In addition, the present invention can be realized by arbitrarily combining components and functions in each embodiment without departing from the scope of the present invention or embodiments obtained by applying various modifications that those skilled in the art may think to each embodiment. The form is also included in the present invention.
１　配光制御デバイス
１０　第１基板
２０　第２基板
３０　配光層
３１　凹凸構造層
３２　屈折率可変層
３３　凸部
３５　絶縁性液体
３６　ナノ粒子
４０　第１電極層
５０　第２電極層 DESCRIPTION OF SYMBOLS 1 Light distribution control device 10 1st board | substrate 20 2nd board | substrate 30 Light distribution layer 31 Concavo-convex structure layer 32 Refractive index variable layer 33 Convex part 35 Insulating liquid 36 Nanoparticle 40 1st electrode layer 50 2nd electrode layer

Claims (4)

  1. 　配光制御デバイスであって、
    　透光性を有する第１基板と、
    　前記第１基板に対向して配置された、透光性を有する第２基板と、
    　前記第１基板と前記第２基板との間に互いに対向して配置された、透光性を有する第１電極層及び第２電極層と、
    　前記第１電極層と前記第２電極層との間に配置され、入射した光を配光する配光層とを備え、
    　前記配光層は、
    　複数の凸部を有する凹凸構造層と、
    　前記複数の凸部間を充填するように配置され、前記第１電極層及び前記第２電極層間に印加される電圧に応じて屈折率が変化する屈折率可変層とを含み、
    　前記配光層は、前記屈折率可変層の屈折率が変化することで、透明状態と、入射光を曲げて進行させる配光状態とが変化可能であり、
    　前記配光層が前記配光状態である場合に、
    　　前記配光制御デバイスを透過する光に対する、配光される光の割合を示す配光率は、２７％以上であり、
    　　前記配光制御デバイスに入射する光に対する、直射領域に進行する光の割合を示す直射率は、１０％以下である
    　配光制御デバイス。     A light distribution control device,
    A light transmitting first substrate;
    A translucent second substrate disposed opposite to the first substrate;
    A translucent first electrode layer and a second electrode layer disposed opposite to each other between the first substrate and the second substrate;
    A light distribution layer disposed between the first electrode layer and the second electrode layer for distributing incident light;
    The light distribution layer is
    An uneven structure layer having a plurality of convex portions,
    And a refractive index variable layer which is disposed so as to fill the spaces between the plurality of convex portions and whose refractive index changes according to a voltage applied between the first electrode layer and the second electrode layer,
    The light distribution layer can change between a transparent state and a light distribution state in which incident light is bent and travels by changing the refractive index of the refractive index variable layer,
    When the light distribution layer is in the light distribution state,
    The light distribution ratio indicating the ratio of light distributed to the light transmitted through the light distribution control device is 27% or more,
    A light distribution control device, in which a direct light ratio indicating a ratio of light traveling to a direct light region to light incident on the light distribution control device is 10% or less.
  2. 　前記配光層が前記透明状態である場合に、前記配光制御デバイスのヘイズは、３．８％以下である
    　請求項１に記載の配光制御デバイス。     The light distribution control device according to claim 1, wherein the haze of the light distribution control device is 3.8% or less when the light distribution layer is in the transparent state.
  3. 　前記配光層は、さらに、前記屈折率可変層の屈折率が変化することで、入射光の透過を抑制する遮熱状態に変化可能であり、
    　前記配光層が前記遮熱状態である場合に、前記配光制御デバイスの日射遮蔽係数は、０．４６以下である
    　請求項１又は２に記載の配光制御デバイス。     Further, the light distribution layer can be changed to a heat shielding state which suppresses transmission of incident light by changing the refractive index of the refractive index variable layer,
    The light distribution control device according to claim 1, wherein a solar radiation shielding coefficient of the light distribution control device is 0.46 or less when the light distribution layer is in the heat shielding state.
  4. 　前記屈折率可変層は、
    　絶縁性液体と、
    　前記絶縁性液体とは屈折率が異なる、前記絶縁性液体に分散された帯電する複数のナノ粒子とを備える
    　請求項１～３のいずれか１項に記載の配光制御デバイス。     The refractive index variable layer is
    An insulating liquid,
    The light distribution control device according to any one of claims 1 to 3, comprising: a plurality of charged nanoparticles dispersed in the insulating liquid that have a refractive index different from that of the insulating liquid.
PCT/JP2018/042809 2017-12-26 2018-11-20 Photoalignment control device WO2019130913A1 (en)

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