WO2019188191A1 - Light distribution control device - Google Patents

Light distribution control device Download PDF

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Publication number
WO2019188191A1
WO2019188191A1 PCT/JP2019/009687 JP2019009687W WO2019188191A1 WO 2019188191 A1 WO2019188191 A1 WO 2019188191A1 JP 2019009687 W JP2019009687 W JP 2019009687W WO 2019188191 A1 WO2019188191 A1 WO 2019188191A1
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WO
WIPO (PCT)
Prior art keywords
light
electrode layer
refractive index
layer
light distribution
Prior art date
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PCT/JP2019/009687
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French (fr)
Japanese (ja)
Inventor
一樹 北村
伊藤　宜弘
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 WO2019188191A1 publication Critical patent/WO2019188191A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • 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

Definitions

  • the present invention relates to a light distribution control device.
  • Patent Literature 1 discloses a daylighting member that takes light toward an indoor ceiling by reflecting light with the uneven shape of the daylighting unit.
  • an object of the present invention is to provide a light distribution control device that can reduce local glare and can efficiently incorporate light when used in a window.
  • a light distribution control device includes a first substrate having translucency, and a second substrate having translucency, which is disposed to face the first substrate.
  • a light distribution layer that distributes incident light, and the light distribution layer includes a concavo-convex structure layer having a plurality of convex portions arranged side by side, and the plurality of convex portions.
  • a refractive index variable layer that is arranged so as to fill a certain concave portion and changes a refractive index according to a voltage applied between the first electrode layer and the second electrode layer, and incident light provided in the concave portion
  • a light-shielding portion that shields at least a part of the refractive index variable layer, the insulating variable liquid, and the insulating liquid Refractive index are different, and a plurality of nanoparticles charged the dispersed in an insulating liquid, the light-shielding portion is conductive.
  • the light distribution control device According to the light distribution control device according to the present invention, it is possible to reduce local glare and to incorporate light efficiently when used for a window.
  • FIG. 1 is a cross-sectional view of a light distribution control device according to an embodiment.
  • FIG. 2 is an enlarged cross-sectional view illustrating a part of the light distribution control device according to the embodiment.
  • FIG. 3A is a plan view schematically showing a planar view shape of a plurality of convex portions of the concavo-convex structure layer of the light distribution control device according to the embodiment.
  • FIG. 3B is a plan view schematically showing a planar view shape of a plurality of convex portions of the concavo-convex structure layer of the light distribution control device according to Modification 1 of the embodiment.
  • FIG. 4 is an enlarged cross-sectional view illustrating a part of the light distribution control device according to the second modification of the embodiment.
  • FIG. 5A is an enlarged cross-sectional view for explaining a non-application mode (transparent state) of the light distribution control device according to the embodiment.
  • FIG. 5B is an enlarged cross-sectional view for explaining a voltage application mode (light distribution state) of the light distribution control device according to the embodiment.
  • FIG. 6 is an enlarged cross-sectional view for explaining one factor of light streaks generated in a conventional light distribution control device.
  • the x axis, the y axis, and the z axis indicate the 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, which is a direction perpendicular to the main surfaces of the first substrate and the second substrate
  • plane view means , When viewed from a direction perpendicular to the main surface of the first substrate or the second substrate.
  • 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 showing a part of the light distribution control device 1 according to the present embodiment in an enlarged manner, and shows a region II surrounded by a one-dot chain 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 that can change the traveling direction of light incident on the light distribution control device 1 (that is, distribute light) and emit the light.
  • the light distribution control device 1 is configured to transmit incident light, and includes a first substrate 10, a second substrate 20, a light distribution layer 30, One electrode layer 40 and a second electrode layer 50 are provided.
  • an adhesion layer for closely adhering the first electrode layer 40 and the uneven structure layer 31 of the light distribution layer 30 may be provided on the surface of the first electrode layer 40 on the light distribution layer 30 side.
  • the adhesion layer is, for example, a translucent adhesive sheet or a resin material generally called 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 paired first substrate 10 and second substrate 20. It is a configuration. In order to maintain the distance between the first substrate 10 and the second substrate 20, a plurality of particulate spacers may be dispersed in the plane, or a columnar structure may be formed.
  • the light distribution control device 1 can be realized, for example, as a window with a light distribution function by being installed in a building window.
  • the light distribution control device 1 is used by being attached to a transparent base material such as an existing window glass through an adhesive layer, for example.
  • the light distribution control device 1 may be used as a building window itself.
  • the first substrate 10 is on the outdoor side
  • the second substrate 20 is on the indoor side
  • the first side surface 34a of the convex portion 34 shown in FIG. 2 is on the lower side (floor side).
  • the second side surface 34b is arranged so as to face the upper side (ceiling side).
  • the refractive index of the refractive index variable layer 32 of the light distribution layer 30 changes depending on 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 concavo-convex structure layer 31 and the variable refractive index layer 32, and light is distributed using refraction and reflection (total reflection) of light by the interface. For example, at least a part of light incident obliquely downward is emitted obliquely upward by the convex portion 34.
  • the light distribution control device 1 switches between the transparent state and the light distribution state according to the magnitude of the voltage applied between the first electrode layer 40 and the second electrode layer 50.
  • the light distribution direction (traveling direction) of light in the light distribution state changes according to the magnitude of the voltage applied between the first electrode layer 40 and the second electrode layer 50.
  • the first substrate 10 and the second substrate 20 are base materials having translucency.
  • a glass substrate or a resin substrate can be used as the first substrate 10 and the second substrate 20.
  • Examples of the material for the glass substrate include soda glass, alkali-free glass, and high refractive index glass.
  • Examples of the material for the resin substrate include resin materials such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), acrylic (PMMA), and 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 of less scattering at the time of destruction.
  • the first substrate 10 and the second substrate 20 may be made of the same material, or may be made of different materials. Moreover, the 1st board
  • the second substrate 20 is a counter substrate facing the first substrate 10 and is disposed at a position facing the first substrate 10.
  • the first substrate 10 and the second substrate 20 are arranged in parallel with a predetermined distance of, for example, 1 ⁇ m to 1000 ⁇ m.
  • substrate 20 are adhere
  • the plan view shape of the first substrate 10 and the second substrate 20 is, for example, a rectangular shape such as a square or a rectangle, but is not limited thereto, and may be a polygon other than a circle or a rectangle, Any shape can 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, the light distribution layer 30 changes the traveling direction of light when the light passes through the light distribution layer 30.
  • the light distribution layer 30 includes an uneven structure layer 31, a refractive index variable layer 32, and a light shielding portion 33.
  • light is reflected at the interface between the concavo-convex structure layer 31 and the refractive index variable layer 32, whereby the traveling direction of the light transmitted through the light distribution control device 1 with respect to the vertical direction is bent.
  • the uneven structure layer 31 is a finely shaped layer provided to make the surface (interface) of the refractive index variable layer 32 uneven. As shown in FIG. 2, the concavo-convex structure layer 31 includes a plurality of convex portions 34 and a plurality of concave portions 35.
  • the concavo-convex structure layer 31 is a concavo-convex structure constituted by a plurality of convex portions 34 having a micro-order size. Between the plurality of convex portions 34 are a plurality of concave portions 35. That is, one concave portion 35 is between two adjacent convex portions 34. In the example illustrated in FIG. 2, an example in which the plurality of convex portions 34 are individually separated is illustrated, but the present invention is not limited thereto.
  • the plurality of convex portions 34 may be individually connected at the root (on the first electrode layer 40 side).
  • a layer (film) -shaped base portion serving as a base of the convex portion 34 may be provided between the plurality of convex portions 34 and the first electrode layer 40.
  • the plurality of protrusions 34 are a plurality of protrusions arranged side by side in the z-axis direction parallel to the main surface of the first substrate 10 (the surface on which the first electrode layer 40 is provided). That is, in the present embodiment, the z-axis direction is an arrangement direction of the plurality of convex portions 34.
  • FIG. 3A is a plan view schematically showing a planar view shape of a plurality of convex portions 34 of the concavo-convex structure layer 31 of the light distribution control device 1 according to the present embodiment.
  • FIG. 3A schematically shows the tip portions of the plurality of convex portions 34 with solid lines when the first substrate 10 side is viewed from the second substrate 20 side.
  • the plurality of convex portions 34 are long convex shapes extending in a direction orthogonal to the arrangement direction. Specifically, the plurality of convex portions 34 are formed in a stripe shape extending in the x-axis direction. Each of the plurality of convex portions 34 extends linearly along the x-axis direction. For example, each of the plurality of convex portions 34 is a quadrangular column that is disposed sideways with respect to the first electrode layer 40.
  • each of the plurality of convex portions 34 has a shape that tapers from the root to the tip.
  • the cross-sectional shape of each of the plurality of convex portions 34 is a tapered shape that tapers along the direction from the first substrate 10 toward the second substrate 20.
  • the sectional shape of the convex portion 34 in the yz section is a trapezoid that tapers along the thickness direction of the light distribution control device 1, but is not limited thereto.
  • the cross-sectional shape of the convex portion 34 may be a substantially triangular shape, other polygons, or a polygon including a curve.
  • the shapes of the plurality of convex portions 34 are the same as each other, but may be different.
  • the substantially trapezoidal or triangular shape includes a trapezoidal or triangular shape with rounded vertices.
  • the substantially trapezoidal shape or the substantially triangular shape includes a case where each side is not completely straight, for example, a case where the side is slightly bent with a displacement of about several percent of the length of each side, or a minute unevenness. Cases are also included.
  • each of the plurality of convex portions 34 has a first side surface 34a and a second side surface 34b.
  • the first side surface 34a and the second side surface 34b are surfaces that intersect the z-axis direction.
  • Each of the first side surface 34a and the second side surface 34b is an inclined surface that is inclined at a predetermined inclination angle with respect to the y-axis direction.
  • the distance between the first side surface 34 a and the second side surface 34 b, that is, the width of the convex portion 34 gradually decreases from the first substrate 10 toward the second substrate 20.
  • the first side surface 34a is a side surface on the vertically lower side among the plurality of side surfaces constituting the convex portion 34.
  • the first side surface 34a is a refracting surface that refracts incident light.
  • the second side surface 34b is, for example, the side surface on the vertically upper side among the plurality of side surfaces constituting the convex portion 34 when the light distribution control device 1 is arranged so that the z-axis coincides with the vertical direction.
  • the second side surface 34b is a reflecting surface that reflects incident light. The reflection here is total reflection, and the second side surface 34b functions as a total reflection surface.
  • the inclination angle of the first side surface 34a and the inclination angle of the second side surface 34b are, for example, in the range of 0 ° to 25 °.
  • the two base angles of the substantially trapezoidal shape or the substantially triangular shape which are the cross-sectional shape of the convex portion 34 are 65 ° or more and 90 ° or less, respectively.
  • at least one of the two base angles may be smaller than 65 °.
  • the inclination angle of the first side surface 34a and the inclination angle of the second side surface 34b may be different from each other or may be the same.
  • the width (length in the z-axis direction) of the plurality of convex portions 34 is, for example, 1 ⁇ m to 20 ⁇ m, and preferably 10 ⁇ m or less, but is not limited thereto. Further, the interval between two adjacent convex portions 34 is, for example, 0 ⁇ m to 100 ⁇ m, but is not limited thereto.
  • the material of the concavo-convex structure layer 31 for example, a resin material having optical transparency 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 trapezoidal cross section by mold pressing using an acrylic resin having a refractive index of 1.5 for green light.
  • FIG. 3B is a plan view schematically showing a planar view shape of the plurality of convex portions 134 of the light distribution control device 101 according to the modification of the present embodiment.
  • the plurality of convex portions 134 are provided so as to form a plurality of wavy lines extending in the x-axis direction when the first substrate 10 is viewed in plan.
  • the x-axis direction is a direction orthogonal to the arrangement direction (z-axis direction) of the plurality of convex portions 134.
  • the plurality of convex portions 134 may be formed in a wavy stripe shape.
  • the plurality of wavy lines are, for example, a sine wave or a triangular wave, but are not limited thereto.
  • each of the plurality of wavy lines may be a wavy line in which a plurality of arcs or elliptical arcs are connected.
  • the shape and size of each of the plurality of wavy lines are the same as each other, but may be different.
  • the positions of the crests and troughs in the x-axis direction may be different for each wavy line.
  • the refractive index variable layer 32 is provided so as to fill a space between the plurality of convex portions 34 (that is, the concave portion 35). 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. As shown in FIG. 2, when the tip of the convex portion 34 and the second electrode layer 50 are separated from each other, the refractive index variable layer 32 includes not only the concave portion 35 but also the tip of the convex portion 34 and the second electrode layer 50. It arrange
  • the refractive index of the refractive index variable layer 32 changes depending on 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 capable of adjusting the refractive index in the visible light band when a voltage is applied between the electrodes.
  • a DC voltage is applied between the first electrode layer 40 and the second electrode layer 50 by a control device (not shown) or the like.
  • the refractive index variable layer 32 includes an insulating liquid 36 and nanoparticles 37 included in the insulating liquid 36.
  • the refractive index variable layer 32 is a nanoparticle dispersion layer in which countless nanoparticles 37 are dispersed in the insulating liquid 36.
  • the insulating liquid 36 is a transparent liquid having insulating properties and is a solvent serving as a dispersion medium in which the nanoparticles 37 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 36 having a refractive index of about 1.4 is used.
  • the kinematic viscosity of the insulating liquid 36 is preferably about 100 mm 2 / s.
  • the insulating liquid 36 has a low dielectric constant (for example, less than the dielectric constant of the concavo-convex structure layer 31), non-flammability (for example, a high flash point having a flash point of 250 ° C. or higher) and low volatility. Also good.
  • the insulating liquid 36 is a hydrocarbon such as an aliphatic hydrocarbon, naphtha, and other petroleum solvents, a low molecular weight halogen-containing polymer, or a mixture thereof.
  • the insulating liquid 36 is a halogenated hydrocarbon such as a fluorinated hydrocarbon.
  • silicone oil or the like can be used.
  • a plurality of nanoparticles 37 are dispersed in the insulating liquid 36.
  • the nanoparticles 37 are fine particles having a particle size of nano-order size.
  • the particle size of the nanoparticles 37 is preferably ⁇ / 4 or less.
  • the particle size of the nanoparticles 37 is preferably as small as possible, preferably 100 nm or less, more preferably several nm to several tens nm.
  • the nanoparticles 37 are made of, for example, a high refractive index material. Specifically, the refractive index of the nanoparticles 37 is higher than the refractive index of the insulating liquid 36. In the present embodiment, the refractive index of the nanoparticles 37 is higher than the refractive index of the concavo-convex structure layer 31.
  • the nanoparticles 37 for example, metal oxide fine particles can be used.
  • the nanoparticles 37 may be made of a material having a high transmittance.
  • transparent zirconia particles having a refractive index of 2.1 composed of zirconium oxide (ZrO 2 ) are used as the nanoparticles 37.
  • the nanoparticles 37 are not limited to zirconium oxide, and may be composed of titanium oxide (TiO 2 : refractive index 2.5) or the like.
  • the nanoparticles 37 are charged particles that are charged.
  • the nanoparticles 37 can be charged positively (plus) or negatively (minus).
  • the nanoparticles 37 are positively (plus) charged.
  • the refractive index variable layer 32 configured in this way, charged nanoparticles 37 are dispersed throughout the insulating liquid 36.
  • the refractive index variable layer 32 is obtained by dispersing zirconia particles having a refractive index of 2.1 as nanoparticles 37 and dispersing them in an insulating liquid 36 having a solvent refractive index of about 1.4. It is said.
  • the overall refractive index (average refractive index) of the refractive index variable layer 32 is set to be approximately the same as the refractive index of the concavo-convex structure layer 31 in a state where the nanoparticles 37 are uniformly dispersed in the insulating liquid 36. In this embodiment, it is about 1.5.
  • the overall refractive index of the refractive index variable layer 32 can be changed by adjusting the concentration (amount) of the nanoparticles 37 dispersed in the insulating liquid 36. Although details will be described later, the amount of the nanoparticles 37 is, for example, such that it is buried in the recesses 35 of the uneven structure layer 31. In this case, the concentration of the nanoparticles 37 with respect to the insulating liquid 36 is about 10% to about 30%.
  • the nanoparticles 37 dispersed in the insulating liquid 36 are charged, when a voltage is applied between the first electrode layer 40 and the second electrode layer 50, the nanoparticles 37 have a polarity with which the nanoparticles 37 are charged. Electrophoreses in the insulating liquid 36 so as to be attracted to the electrode layer having a polarity different from that of the electrode layer and is unevenly distributed in the insulating liquid 36. In the present embodiment, since the nanoparticles 37 are positively charged, they are attracted to the negative electrode layer of the first electrode layer 40 and the second electrode layer 50.
  • the particle distribution of the nanoparticles 37 in the refractive index variable layer 32 can be changed to give the concentration distribution of the nanoparticles 37 in the refractive index variable layer 32, so that the refractive index in the refractive index variable layer 32 can be obtained.
  • the refractive index variable layer 32 mainly functions as a refractive index adjustment layer that can adjust the refractive index for light in the visible light band.
  • the refractive index variable layer 32 includes, for example, 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 is formed by injecting a refractive index variable material by a vacuum injection method while being sealed with a seal resin. Alternatively, the refractive index variable layer 32 is 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 attaching the second substrate 20 on which the second electrode layer 50 is formed. You may form by combining.
  • the refractive index variable material is an insulating liquid 36 in which nanoparticles 37 are dispersed. An insulating liquid 36 in which nanoparticles 37 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.
  • the light shielding unit 33 shields at least part of the incident light.
  • shielding means not only completely blocking incident light but also blocking only a part and transmitting the rest.
  • light blocking refers to a state where blocking is more dominant than light transmission.
  • the transmittance for visible light of the light-shielding portion 33 is lower than 50%, preferably 20% or less, or 10% or less.
  • the light shielding portion 33 is a light shielding film provided on the bottom of the recess 35. Specifically, like the concavo-convex structure layer 31, the light shielding portion 33 is formed in a stripe shape extending in the x-axis direction. In the present embodiment, the light shielding portions 33 are provided in all the concave portions 35, but the present invention is not limited to this.
  • the light-shielding part 33 may be provided every n pieces (n is a natural number of 1 or more) of the plurality of recesses 35 along the z-axis direction.
  • the light shielding part 33 includes, for example, a black pigment.
  • a black pigment for example, a carbon black pigment such as carbon black or an oxide black pigment can be used.
  • black aqueous ink is applied in the recesses 35 using a bar coater and then dried in an environment of 100 ° C.
  • the transmittance of the light shielding part 33 can be adjusted by the concentration of black aqueous ink to be used (specifically, the amount of black pigment) and the number of coatings. Specifically, the transmittance of the light shielding portion 33 can be lowered (that is, it is difficult for light to pass through) by increasing the concentration of ink or increasing the number of times of application.
  • the width (z-axis direction) of the light shielding portion 33 is the width of the concave portion 35, that is, the distance between the adjacent convex portions 34.
  • the width of the light shielding portion 33 is 0 ⁇ m to 100 ⁇ m.
  • the width of the light shielding part 33 is smaller than the thickness of the base part of the convex part 34 (the bottom of the trapezoid).
  • the width of the light shielding portion 33 is equal to or less than one fifth of the thickness of the root portion of the convex portion 34, for example, 2 ⁇ m.
  • the light shielding portion 33 has conductivity.
  • the electrical resistance value of the light shielding part 33 is smaller than the electrical resistance value of the insulating liquid 36 and is equal to or greater than the electrical resistance value of the first electrode layer 40.
  • the sheet resistance of the light shielding part 33 is 100 k ⁇ / sq or less.
  • the sheet resistance of the light shielding part 33 may be 10 k ⁇ / sq or less, or 1 k ⁇ / sq or less.
  • the light shielding part 33 has conductivity by including conductive carbon black.
  • the light shielding part 33 is in contact with both the first electrode layer 40 and the refractive index variable layer 32, for example.
  • the light shielding part 33 has substantially the same potential as the first electrode layer 40.
  • the nanoparticles 37 contained in the refractive index variable layer 32 are easily attracted to the light shielding portion 33 with which the insulating liquid 36 is in contact. Since the light shielding part 33 has conductivity, a current can flow between the first electrode layer 40 and the second electrode layer 50. Thereby, the migration of the nanoparticles 37 can be performed smoothly, and the refractive index distribution of the refractive index variable layer 32 can be made different.
  • the light shielding part 33 is formed with a substantially uniform film thickness.
  • the thickness (y-axis direction) of the light shielding part 33 is, for example, 200 nm to 1 ⁇ m.
  • FIG. 4 is an enlarged cross-sectional view showing a part of a light distribution control device 201 according to a modification of the present embodiment.
  • the 4 includes a light distribution layer 230 instead of the light distribution layer 30.
  • the light distribution layer 230 includes a light shielding unit 233 instead of the light shielding unit 33.
  • the film thickness at both ends of the light shielding part 233 is larger than the film thickness at the central part of the light shielding part 233.
  • the interface between the light shielding part 233 and the refractive index variable layer 32 is recessed in a concave shape.
  • the interface between the light shielding part 233 and the refractive index variable layer 32 has a curved surface.
  • the light shielding part 233 is formed by drying ink containing a black pigment, for example. At this time, when the ink is applied and dried in a posture in which the first substrate 10 is vertically downward (that is, the positive direction of the y axis is vertically upward), the concave surface is naturally formed by the weight of the ink and the surface tension. It is formed.
  • the light shielding part 233 may be formed by forming the light shielding part 33 with a uniform film thickness and then shaving the central part of the light shielding part 33 by etching or the like.
  • the light shielding portions 33 and 233 may not be black.
  • the light shielding portions 33 and 233 may be obtained by drying a solvent ink containing a colored pigment. Drying may be natural drying.
  • first electrode layer 40 and the second electrode layer 50 are electrically paired.
  • the first electrode layer 40 and the second electrode layer 50 are paired not only electrically but also in arrangement, and are arranged 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 arranged so as to sandwich the light distribution layer 30.
  • the first electrode layer 40 and the second electrode layer 50 are translucent and transmit incident light.
  • the first electrode layer 40 and the second electrode layer 50 are, for example, transparent conductive layers.
  • a conductor-containing resin made of a resin containing a conductor such as a transparent metal oxide such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), silver nanowires or conductive particles, or A metal thin film such as a silver thin film can be used.
  • the 1st electrode layer 40 and the 2nd electrode layer 50 may be these single layer structures, and these laminated structures (for example, laminated structure of a transparent metal oxide and a metal thin film) may be sufficient as them.
  • 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 1st electrode layer 40 and the 2nd electrode layer 50 are comprised so that electrical connection with an external power supply is attained, for example.
  • electrode pads or the like for connecting to an external power source may be formed on the first substrate 10 and the second substrate 20 by being drawn from each of the first electrode layer 40 and the second electrode layer 50.
  • the first electrode layer 40 and the second electrode layer 50 are each formed by forming a conductive film such as ITO by vapor deposition, sputtering, or the like, for example.
  • FIG. 5A is an enlarged cross-sectional view for explaining a non-application mode (transparent state) of the light distribution control device 1 according to the present embodiment. Further, in FIG. 5A, the paths of the light L1 and the light L2 that enter the light distribution control device 1 obliquely are indicated by arrows.
  • FIG. 5A 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 equipotential with each other. In this case, since the nanoparticles 37 are not attracted to any electrode layer, the nanoparticles 37 are dispersed throughout the insulating liquid 36.
  • the refractive index of the refractive index variable layer 32 in a state where the nanoparticles 37 are dispersed throughout the insulating liquid 36 is about 1.5 as described above.
  • the refractive index of the convex part 34 of the concavo-convex structure layer 31 is about 1.5. That is, the plurality of convex portions 34 and the refractive index variable layer 32 have the same refractive index. Therefore, the refractive index is uniform throughout the light distribution layer 30.
  • the light distribution control device 1 is in a transparent state that allows the incident light to pass through substantially as it is (without changing the traveling direction).
  • the light L1 is actually incident on the first substrate 10, emitted from the second substrate 20, passed through the interface between the first substrate 10 and the first electrode layer 40, and the second. Although it is refracted when the passing medium changes, such as when passing through the interface between the electrode layer 50 and the second substrate 20, it is not shown in FIG. 5A. The same applies to FIG. 5B described later.
  • FIG. 5B is an enlarged cross-sectional view for explaining a voltage application mode (light distribution state) of the light distribution control device 1 according to the present embodiment. Further, in FIG. 5B, the paths of the light L1 and the light L2 that are obliquely incident on the light distribution control device 1 are indicated by thick arrows.
  • a predetermined voltage is applied between the first electrode layer 40 and the second electrode layer 50.
  • a 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.
  • the second electrode layer 50 has a higher potential than the first electrode layer 40. For this reason, the positively charged nanoparticles 37 migrate toward the first electrode layer 40 and enter the concave portion 35 of the concave-convex structure layer 31 and accumulate.
  • the nanoparticles 37 are unevenly distributed on the uneven structure layer 31 side in the refractive index variable layer 32, whereby the particle distribution of the nanoparticles 37 is changed and the refractive index distribution in the refractive index variable layer 32 is not uniform. Disappear. Specifically, as shown in FIG. 5B, a concentration distribution of nanoparticles 37 is formed in the refractive index variable layer 32.
  • the concentration of the nanoparticles 37 is high, and in the second region 32b on the second electrode layer 50 side, the concentration of the nanoparticles 37 is low. Accordingly, a difference in refractive index occurs between the first region 32a and the second region 32b.
  • the refractive index of the nanoparticles 37 is higher than the refractive index of the insulating liquid 36.
  • the refractive index of the first region 32a in which the concentration of the nanoparticles 37 is high is higher than the refractive index of the second region 32b in which the concentration of the nanoparticles 37 is low, that is, the proportion of the insulating liquid 36 is large.
  • the refractive index of the first region 32a is greater than about 1.5 to about 1.8 depending on the concentration of the nanoparticles 37.
  • the refractive index of the second region 32 b becomes a value less than about 1.4 to less than about 1.5 depending on the concentration of the nanoparticles 37.
  • the refractive index of the plurality of protrusions 34 is about 1.5, when a voltage is applied between the first electrode layer 40 and the second electrode layer 50, the protrusion 34 and the first region 32a There is a difference in refractive index between them. Therefore, as shown in FIG. 5B, when the light L1 is incident from an oblique direction, the incident light L1 is refracted by the first side surface 34a of the convex portion 34 and then totally reflected by the second side surface 34b.
  • the incident angle and the emission angle of the light L1 are different in the vertical cross section.
  • the light L1 incident from diagonally upward to diagonally downward is emitted from the light distribution control device 1 diagonally upward.
  • the light distribution control device 1 enters a light distribution state in which incident light is transmitted with its traveling direction bent.
  • the degree of aggregation of the nanoparticles 37 can be changed according to the magnitude of the applied voltage.
  • the refractive index of the refractive index variable layer 32 changes depending on the degree of aggregation of the nanoparticles 37. For this reason, it is also possible to change the light distribution direction by changing the difference in refractive index between the first side surface 34 a and the second side surface 34 b (interface) of the convex portion 34.
  • FIG. 6 is an enlarged cross-sectional view for explaining one factor of light streaks generated in the conventional light distribution control device 1x.
  • the light distribution control device 1x illustrated in FIG. 6 is different from the light distribution control device 1 illustrated in FIG. 2 according to the embodiment in that the light shielding unit 33 is not provided.
  • FIG. 6 shows a case where the light distribution control device 1x is in the light distribution mode. Specifically, the refractive index of the first region 32 a of the refractive index variable layer 32 of the light distribution layer 30 x is larger than the refractive index of the convex portion 34.
  • the light L3 incident on the concave portion 35 of the light distribution layer 30x from the first electrode layer 40 is partially scattered by the difference in refractive index between the first electrode layer 40 and the light distribution layer 30x (see FIG. Scattered light Lx shown in FIG.
  • Most of the scattered light is light traveling in the yz plane, and thus appears as a streak of light along the z-axis direction. Thereby, for the person who sees the light distribution control device 1x from the front, a linear local glare is felt.
  • the light shielding portion 33 is provided in the concave portion 35 of the concave-convex structure layer 31.
  • the light L ⁇ b> 2 incident on the light shielding part 33 among the light obliquely incident on the light distribution control device 1 is shielded by the light shielding part 33.
  • production of the scattered light Lx as shown in FIG. 6 is suppressed.
  • each intensity of the scattered light Lx is weaker than the main component of the light L1, it is sufficiently attenuated by the light shielding unit 33.
  • the light L ⁇ b> 2 is blocked by the light blocking unit 33.
  • the light distribution control device 1 can transmit most (for example, 80%) or more of light incident on the light distribution control device 1.
  • the light shielding unit 33 may transmit a part of the light L2.
  • the transmitted light of the light L2 is reflected by the second side surface 34b of the convex portion 34 and emitted from the second substrate 20 obliquely upward, similarly to the light L1.
  • the transmitted light of the light L2 passes through the light distribution control device 1 as it is, as with the light L1.
  • the light distribution control device 1 includes the first substrate 10 having translucency, and the second substrate 20 having translucency disposed so as to face the first substrate 10. And the first electrode layer 40 and the second electrode layer 50 having translucency, which are disposed opposite to each other between the first substrate 10 and the second substrate 20, and the first electrode layer 40 and the second electrode.
  • the light distribution layer 30 is disposed between the layer 50 and distributes incident light.
  • the light distribution layer 30 is disposed so as to fill the concavo-convex structure layer 31 having the plurality of convex portions 34 arranged side by side and the concave portion 35 between the plurality of convex portions 34, and the first electrode layer 40 and the second electrode layer 40.
  • the refractive index variable layer 32 includes an insulating liquid 36 and a plurality of charged nanoparticles 37 dispersed in the insulating liquid 36 having a refractive index different from that of the insulating liquid 36.
  • the light shielding part 33 has conductivity.
  • the light shielding portion 33 is provided in the concave portion 35, the scattered light generated in the concave portion 35 can be suppressed. Therefore, generation of light streaks is suppressed and local glare is reduced.
  • the light shielding portion 33 has conductivity, electrophoresis of the charged nanoparticles 37 included in the refractive index variable layer 32 can be caused.
  • the light shielding unit 33 has the same polarity as the first electrode layer 40. Therefore, the plurality of nanoparticles 37 dispersed in the insulating liquid 36 are easily attracted to the light shielding portion 33 that is in contact with the insulating liquid 36. For this reason, for example, a plurality of nanoparticles 37 are attracted to the light shielding portion 33 and accumulated in the concave portion 35, thereby generating a refractive index difference between the convex portion 34 and the refractive index variable layer 32.
  • the light traveling direction can be bent by refracting or reflecting the incident light by the refractive index difference.
  • the difference in refractive index between the plurality of convex portions 34 and the refractive index variable layer 32 is adjusted by adjusting the voltage applied to the first electrode layer 40 and the second electrode layer 50.
  • the light distribution control device 1 can be made transparent by making the refractive index difference between the plurality of convex portions 34 and the refractive index variable layer 32 substantially zero.
  • the interface between the convex portions 34 and the refractive index variable layer 32 (specifically, the second of the convex portions 34).
  • the side surface 34b) can be made to function as a total reflection surface, and the traveling direction can be bent by totally reflecting incident light. That is, the light distribution control device 1 can be in a light distribution state.
  • the light distribution control device 1 As described above, according to the light distribution control device 1 according to the present embodiment, local glare can be reduced, and light can be taken in efficiently when used in a window.
  • the inventors made a prototype of the light distribution control device 1 and applied a predetermined voltage between the first electrode layer 40 and the second electrode layer 50. As a result, the light distribution control device 1 can be in a light distribution state. Was confirmed. In addition, when the light distribution control device 1 is in the light distribution state, it was confirmed that a current flows between the first electrode layer 40 and the second electrode layer 50. That is, it is assumed that the light distribution control device 1 according to the present embodiment is a current control device that changes its optical state when a current flows.
  • the light shielding part 33 is a light shielding film provided on the bottom of the recess 35.
  • the light shielding part 33 and the first electrode layer 40 can be set to substantially the same potential, the nanoparticles 37 are more easily attracted to the light shielding part 33. Therefore, the migration of the nanoparticles 37 in the insulating liquid 36 is performed smoothly, and the light distribution state and the transparent state can be quickly switched.
  • the film thickness at both ends of the light shielding film may be larger than the film thickness at the center of the light shielding film.
  • the central portion of the light shielding portion 233 is thinned, so that the light transmittance at the central portion is increased. Accordingly, since the main incident light can be transmitted while blocking the scattered light, the daylighting efficiency can be increased while suppressing local glare. Moreover, since the visibility of the outdoors can be improved for the person who is indoors, the original function (namely, transparency) as a window can be improved.
  • the plurality of convex portions 134 may be provided so as to form a plurality of wavy lines extending in a direction orthogonal to the arrangement direction of the plurality of convex portions 134 when the first substrate 10 is viewed in plan.
  • the plurality of convex portions 134 are provided so as to form a plurality of wavy lines in a plan view. For example, when the peak position, period, amplitude, etc. are different for each wavy line, the periodicity of the plurality of convex portions 134 can be easily disturbed. When the periodicity is disturbed, the diffraction phenomenon is suppressed and rainbow irregularities can be mitigated.
  • the second side surface 34b functioning as a total reflection surface includes a surface that intersects the x axis obliquely along the wavy line. For this reason, a part of the light transmitted through the light distribution control device 1 is distributed so as to spread in the direction along the x axis (for example, the left-right direction). For this reason, the range which can distribute light, specifically, the range which can be irradiated indoors can be expanded.
  • the electrical resistance value of the light shielding part 33 is smaller than the electrical resistance value of the insulating liquid 36 and is equal to or greater than the electrical resistance value of the first electrode layer 40.
  • the resistance of the light shielding part 33 is reduced and the potential of the light shielding part 33 can be brought close to the potential of the first electrode layer 40, so that the nanoparticles 37 are easily attracted to the light shielding part 33. Therefore, the migration of the nanoparticles 37 in the insulating liquid 36 is performed smoothly, and the light distribution state and the transparent state can be quickly switched.
  • the present invention is not limited thereto.
  • the light shielding part 33 or 233 may not be in contact with the first electrode layer 40, and an adhesive layer or the like may be provided between the first electrode layer 40 and the light shielding part 33 or 233.
  • the plurality of convex portions 34 may be divided into a plurality of portions in the x-axis direction.
  • the plurality of convex portions 34 may be arranged so as to be scattered in a matrix or the like. That is, you may arrange
  • the refractive index of the nanoparticles 37 may be lower than the refractive index of the insulating liquid 36.
  • a transparent state and a light distribution state can be realized.
  • the light distribution state may be realized when a voltage is not applied between the first electrode layer 40 and the second electrode layer 50, and the transparent state may be realized when a voltage is applied.
  • the nanoparticles 37 are positively charged, but the present invention is not limited to this. That is, the nanoparticles 37 may be negatively charged.
  • a direct voltage 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. Good.
  • the plurality of nanoparticles 37 may include a plurality of types of nanoparticles having different optical characteristics.
  • a transparent first nanoparticle charged positively and an opaque (black or the like) second nanoparticle charged negatively may be included.
  • 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 refractive index variable layer changes using the birefringence of the liquid crystal molecules contained in the liquid crystal material.
  • the refractive index of the refractive index variable layer changes. Thereby, the transparent state, the light distribution state, and the light distribution direction in the light distribution state can be controlled.
  • sunlight is exemplified as light incident on the light distribution control device.
  • the present invention is not limited to this.
  • the light incident on the light distribution control device may be light emitted from a light emitting device such as a lighting device.
  • the light distribution control device is not limited to being installed in a building window, and may be installed in a car window, for example.
  • the light distribution control device can also be used for a light distribution control member such as a light-transmitting cover of a lighting fixture.
  • the light distribution control device can also be used as a blindfold member that utilizes light scattering at the interface of the concavo-convex structure.
  • the embodiment can be realized by arbitrarily combining the components and functions in each embodiment without departing from the scope of the present invention, or a form obtained by subjecting each embodiment to various modifications conceived by those skilled in the art. Forms are also included in the present invention.

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Abstract

A light distribution control device (1) according to the present invention is provided with: a first substrate (10) and a second substrate (20), which are arranged so as to face each other and have light transmitting properties; a first electrode layer (40) and a second electrode layer (50), which are arranged between the first substrate (10) and the second substrate (20) so as to face each other and have light transmitting properties; and a light distribution layer (30) which is arranged between the first electrode layer (40) and the second electrode layer (50). The light distribution layer (30) comprises: a recessed and projected structure layer (31) which has a plurality of projections (34) that are arranged side by side; a refractive index varying layer (32) which is arranged so as to fill up a recess (35) that is a space between the plurality of projections (34); and a light-blocking part (33) which is provided in the recess (35) so as to block at least some of incident light. The refractive index varying layer (32) is provided with: an insulating liquid (36); and a plurality of charged nanoparticles (37) which have a refractive index that is different from the refractive index of the insulating liquid (36), and which are dispersed in the insulating liquid (36). The light-blocking part (33) is electrically conductive.

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を効率良く屋内に採り入れる採光部材が知られている。例えば、特許文献１には、採光部の凹凸形状によって光を反射することで、屋内の天井に向けて光を採り入れる採光部材が開示されている。 Conventionally, there is known a daylighting member that efficiently takes outside light such as sunlight incident from the outside indoors. For example, Patent Literature 1 discloses a daylighting member that takes light toward an indoor ceiling by reflecting light with the uneven shape of the daylighting unit.
国際公開第２０１５／１９４４９９号International Publication No. 2015/194499
　しかしながら、上記従来の採光部材に太陽光が入射した場合、縦（垂直）方向に沿って光の筋が発生する。このため、屋内に居る人にとって、窓を見た場合に局所的に眩しく感じられる。 However, when sunlight enters the conventional daylighting member, streaks of light are generated along the vertical (vertical) direction. For this reason, when it sees a window, it will feel locally dazzling for the person who is indoors.
　そこで、本発明は、局所的な眩しさを軽減することができ、かつ、窓に利用された場合に効率良く光を採り入れ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。 Accordingly, an object of the present invention is to provide a light distribution control device that can reduce local glare and can efficiently incorporate light when used in a window.
　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、並んで配置された複数の凸部を有する凹凸構造層と、前記複数の凸部間である凹部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、前記凹部に設けられた、入射した光の少なくとも一部を遮光する遮光部とを含み、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、前記遮光部は、導電性を有する。 In order to achieve the above object, a light distribution control device according to one embodiment of the present invention includes a first substrate having translucency, and a second substrate having translucency, which is disposed to face the first substrate. A first electrode layer and a second electrode layer having translucency disposed opposite to each other between the first substrate and the second substrate; the first electrode layer and the second electrode layer; A light distribution layer that distributes incident light, and the light distribution layer includes a concavo-convex structure layer having a plurality of convex portions arranged side by side, and the plurality of convex portions. A refractive index variable layer that is arranged so as to fill a certain concave portion and changes a refractive index according to a voltage applied between the first electrode layer and the second electrode layer, and incident light provided in the concave portion A light-shielding portion that shields at least a part of the refractive index variable layer, the insulating variable liquid, and the insulating liquid Refractive index are different, and a plurality of nanoparticles charged the dispersed in an insulating liquid, the light-shielding portion is conductive.
　本発明に係る配光制御デバイスによれば、局所的な眩しさを軽減することができ、かつ、窓に利用された場合に効率良く光を採り入れることができる。 According to the light distribution control device according to the present invention, it is possible to reduce local glare and to incorporate light efficiently when used for a window.
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 an embodiment. 図２は、実施の形態に係る配光制御デバイスの一部を拡大して示す拡大断面図である。FIG. 2 is an enlarged cross-sectional view illustrating a part 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凹凸構造層の複数の凸部の平面視形状を模式的に示す平面図である。FIG. 3A is a plan view schematically showing a planar view shape of a plurality of convex portions of the concavo-convex structure layer of the light distribution control device according to the embodiment. 図３Ｂは、実施の形態の変形例１に係る配光制御デバイスの凹凸構造層の複数の凸部の平面視形状を模式的に示す平面図である。FIG. 3B is a plan view schematically showing a planar view shape of a plurality of convex portions of the concavo-convex structure layer of the light distribution control device according to Modification 1 of the embodiment. 図４は、実施の形態の変形例２に係る配光制御デバイスの一部を拡大して示す拡大断面図である。FIG. 4 is an enlarged cross-sectional view illustrating a part of the light distribution control device according to the second modification of the embodiment. 図５Ａ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. 5A is an enlarged cross-sectional view for explaining a non-application mode (transparent state) of the light distribution control device according to the embodiment. 図５Ｂは、実施の形態に係る配光制御デバイスの電圧印加モード（配光状態）を説明するための拡大断面図である。FIG. 5B is an enlarged cross-sectional view for explaining a voltage application mode (light distribution state) of the light distribution control device according to the embodiment. 図６は、従来の配光制御デバイスで発生する光の筋の一要因を説明するための拡大断面図である。FIG. 6 is an enlarged cross-sectional view for explaining one factor of light streaks generated in a conventional light distribution control device.
　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 of the embodiments described below shows a specific example of the present invention. Therefore, numerical values, shapes, materials, components, arrangement 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 constituent elements in the following embodiments, constituent elements not described in the independent claims are described as arbitrary constituent elements.
　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。 Each figure is a schematic diagram and is not necessarily shown strictly. Therefore, for example, the scales and the like do not necessarily match in each drawing. Moreover, in each figure, the same code | symbol is attached | subjected about the substantially same structure, The overlapping description is abbreviate | 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。 In addition, in this specification, terms indicating the relationship between elements such as parallel or vertical, terms indicating the shape of an element such as a triangle or trapezoid, and numerical ranges are not expressions expressing only strict meanings. It is an expression that means 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。 In the present specification and drawings, the x axis, the y axis, and the z axis indicate the 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. In the present specification, the “thickness direction” means the thickness direction of the light distribution control device, which is a direction perpendicular to the main surfaces of the first substrate and the second substrate, and “plan view” means , When viewed from a 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, the 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の一部を拡大して示す拡大断面図であり、図１の一点鎖線で囲まれる領域ＩＩを拡大して示している。 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 showing a part of the light distribution control device 1 according to the present embodiment in an enlarged manner, and shows a region II surrounded by a one-dot chain 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 that can change the traveling direction of light incident on the light distribution control device 1 (that is, distribute light) and emit 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 includes a first substrate 10, a second substrate 20, a light distribution layer 30, One 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。 It should be noted that an adhesion layer for closely adhering the first electrode layer 40 and the uneven structure layer 31 of the light distribution layer 30 may be provided on the surface of the first electrode layer 40 on the light distribution layer 30 side. The adhesion layer is, for example, a translucent adhesive sheet or a resin material generally called 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 paired first substrate 10 and second substrate 20. It is a configuration. In order to maintain the distance between the first substrate 10 and the second substrate 20, a plurality of particulate spacers may be dispersed in the plane, or a columnar structure may be formed.
　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３４の第１側面３４ａが下側（床側）に面し、第２側面３４ｂが上側（天井側）に面するように配置されている。 The light distribution control device 1 can be realized, for example, as a window with a light distribution function by being installed in a building window. The light distribution control device 1 is used by being attached to a transparent base material such as an existing window glass through an adhesive layer, for example. Alternatively, the light distribution control device 1 may be used as a building window 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 first side surface 34a of the convex portion 34 shown in FIG. 2 is on the lower side (floor side). The second side surface 34b is arranged so as to face the 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。例えば、斜め下方に向けて入射する光の少なくとも一部は、凸部３４によって斜め上方に向けて出射される。 In the light distribution control device 1, the refractive index of the refractive index variable layer 32 of the light distribution layer 30 changes depending on the voltage applied between the first electrode layer 40 and the second electrode layer 50. Thereby, a difference in refractive index occurs at the interface between the concavo-convex structure layer 31 and the variable refractive index layer 32, and light is distributed using refraction and reflection (total reflection) of light by the interface. For example, at least a part of light incident obliquely downward is emitted obliquely upward by the convex portion 34.
　第１電極層４０及び第２電極層５０間に印加される電圧の大きさに応じて、配光制御デバイス１は、透明状態及び配光状態が切り替わる。また、配光制御デバイス１は、第１電極層４０及び第２電極層５０間に印加される電圧の大きさに応じて、配光状態における光の配光方向（進行方向）が変化する。 The light distribution control device 1 switches between the transparent state and the light distribution state according to the magnitude of the voltage applied between the first electrode layer 40 and the second electrode layer 50. In the light distribution control device 1, the light distribution direction (traveling direction) of light in the light distribution state changes according to the magnitude of the voltage applied between the first electrode layer 40 and the second electrode layer 50.
　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 base materials having translucency. As the first substrate 10 and the second substrate 20, for example, a glass substrate or a resin substrate can be used.
　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 for the glass substrate include soda glass, alkali-free glass, and high refractive index glass. Examples of the material for the resin substrate include resin materials such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), acrylic (PMMA), and epoxy. The glass substrate has the advantages of high light transmittance and low moisture permeability. On the other hand, the resin substrate has an advantage of less scattering at the time of destruction.
　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. Moreover, the 1st board | substrate 10 and the 2nd board | substrate 20 are not restricted to a rigid board | substrate, The flexible board | substrate which has flexibility may be sufficient. 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 a counter substrate facing the first substrate 10 and is disposed at a position facing the first substrate 10. The first substrate 10 and the second substrate 20 are arranged in parallel with a predetermined distance of, for example, 1 μm to 1000 μm. The 1st board | substrate 10 and the 2nd board | substrate 20 are adhere | attached by sealing resin, such as the adhesive agent formed in the frame shape at the edge part of each other.
　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。 The plan view shape of the first substrate 10 and the second substrate 20 is, for example, a rectangular shape such as a square or a rectangle, but is not limited thereto, and may be a polygon other than a circle or a rectangle, Any shape can 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. The light distribution layer 30 distributes the incident light. That is, the light distribution layer 30 changes the traveling direction of light when the light passes through the light distribution layer 30.
　配光層３０は、凹凸構造層３１と、屈折率可変層３２と、遮光部３３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、鉛直方向に対する進行方向が曲げられる。 The light distribution layer 30 includes an uneven structure layer 31, a refractive index variable layer 32, and a light shielding portion 33. In the present embodiment, light is reflected at the interface between the concavo-convex structure layer 31 and the refractive index variable layer 32, whereby the traveling direction of the light transmitted through the light distribution control device 1 with respect to the vertical direction 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３４と、複数の凹部３５とを有する。 [Uneven structure layer]
The uneven structure layer 31 is a finely shaped layer provided to make the surface (interface) of the refractive index variable layer 32 uneven. As shown in FIG. 2, the concavo-convex structure layer 31 includes a plurality of convex portions 34 and a plurality of concave portions 35.
　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３４によって構成された凹凸構造体である。複数の凸部３４の間が、複数の凹部３５である。すなわち、隣り合う２つの凸部３４の間が、１つの凹部３５である。図２に示される例では、複数の凸部３４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３４は根元（第１電極層４０側）で個々に接続されていてもよい。また、例えば、複数の凸部３４と第１電極層４０との間に凸部３４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 constituted by a plurality of convex portions 34 having a micro-order size. Between the plurality of convex portions 34 are a plurality of concave portions 35. That is, one concave portion 35 is between two adjacent convex portions 34. In the example illustrated in FIG. 2, an example in which the plurality of convex portions 34 are individually separated is illustrated, but the present invention is not limited thereto. The plurality of convex portions 34 may be individually connected at the root (on the first electrode layer 40 side). In addition, for example, a layer (film) -shaped base portion serving as a base of the convex portion 34 may be provided between the plurality of convex portions 34 and the first electrode layer 40.
　複数の凸部３４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３４の並び方向である。 The plurality of protrusions 34 are a plurality of protrusions arranged side by side in the z-axis direction parallel to the main surface of the first substrate 10 (the surface on which the first electrode layer 40 is provided). That is, in the present embodiment, the z-axis direction is an arrangement direction of the plurality of convex portions 34.
　図３Ａは、本実施の形態に係る配光制御デバイス１の凹凸構造層３１の複数の凸部３４の平面視形状を模式的に示す平面図である。なお、図３Ａは、第２基板２０側から第１基板１０側を見た場合において、複数の凸部３４の先端部分を実線で模式的に示している。 FIG. 3A is a plan view schematically showing a planar view shape of a plurality of convex portions 34 of the concavo-convex structure layer 31 of the light distribution control device 1 according to the present embodiment. FIG. 3A schematically shows the tip portions of the plurality of convex portions 34 with solid lines when the first substrate 10 side is viewed from the second substrate 20 side.
　図３Ａに示されるように、本実施の形態では、複数の凸部３４は、その並び方向に直交する方向に延在する長尺の凸状である。具体的には、複数の凸部３４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３４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３４の各々は、第１電極層４０に対して横倒しに配置された四角柱である。 As shown in FIG. 3A, in the present embodiment, the plurality of convex portions 34 are long convex shapes extending in a direction orthogonal to the arrangement direction. Specifically, the plurality of convex portions 34 are formed in a stripe shape extending in the x-axis direction. Each of the plurality of convex portions 34 extends linearly along the x-axis direction. For example, each of the plurality of convex portions 34 is a quadrangular column that is disposed sideways with respect to the first electrode layer 40.
　図２に示されるように、複数の凸部３４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３４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３４のｙｚ断面における断面形状は、配光制御デバイス１の厚み方向に沿って先細る台形であるが、これに限らない。凸部３４の断面形状は、略三角形でもよく、その他の多角形、又は、カーブを含む多角形などでもよい。複数の凸部３４の形状は、互いに同じであるが、異なっていてもよい。 As shown in FIG. 2, each of the plurality of convex portions 34 has a shape that tapers from the root to the tip. Specifically, the cross-sectional shape of each of the plurality of convex portions 34 is a tapered shape that tapers along the direction from the first substrate 10 toward the second substrate 20. In the present embodiment, the sectional shape of the convex portion 34 in the yz section is a trapezoid that tapers along the thickness direction of the light distribution control device 1, but is not limited thereto. The cross-sectional shape of the convex portion 34 may be a substantially triangular shape, other polygons, or a polygon including a curve. The shapes of the plurality of convex portions 34 are the same as each other, but may be different.
　なお、略台形又は略三角形には、頂点が丸みを帯びた台形又は三角形も含まれる。また、略台形又は略三角形には、各辺が完全に直線ではない場合、例えば、各辺の長さの数％程度の変位で僅かに屈曲している場合、又は、微小な凹凸が含まれる場合も含まれる。 Note that the substantially trapezoidal or triangular shape includes a trapezoidal or triangular shape with rounded vertices. In addition, the substantially trapezoidal shape or the substantially triangular shape includes a case where each side is not completely straight, for example, a case where the side is slightly bent with a displacement of about several percent of the length of each side, or a minute unevenness. Cases are also included.
　本実施の形態では、図２に示されるように、複数の凸部３４の各々は、第１側面３４ａ及び第２側面３４ｂを有する。第１側面３４ａ及び第２側面３４ｂは、ｚ軸方向に交差する面である。第１側面３４ａ及び第２側面３４ｂ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。第１側面３４ａ及び第２側面３４ｂの間隔、すなわち、凸部３４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 34 has a first side surface 34a and a second side surface 34b. The first side surface 34a and the second side surface 34b are surfaces that intersect the z-axis direction. Each of the first side surface 34a and the second side surface 34b is an inclined surface that is inclined at a predetermined inclination angle with respect to the y-axis direction. The distance between the first side surface 34 a and the second side surface 34 b, that is, the width of the convex portion 34 gradually decreases from the first substrate 10 toward the second substrate 20.
　第１側面３４ａ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３４を構成する複数の側面のうち、鉛直下方側の側面である。第１側面３４ａは、入射光を屈折させる屈折面である。 For example, when the light distribution control device 1 is arranged so that the z-axis coincides with the vertical direction, the first side surface 34a is a side surface on the vertically lower side among the plurality of side surfaces constituting the convex portion 34. The first side surface 34a is a refracting surface that refracts incident light.
　第２側面３４ｂ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３４を構成する複数の側面のうち、鉛直上方側の側面である。第２側面３４ｂ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、第２側面３４ｂは、全反射面として機能する。 The second side surface 34b is, for example, the side surface on the vertically upper side among the plurality of side surfaces constituting the convex portion 34 when the light distribution control device 1 is arranged so that the z-axis coincides with the vertical direction. The second side surface 34b is a reflecting surface that reflects incident light. The reflection here is total reflection, and the second side surface 34b functions as a total reflection surface.
　第１側面３４ａの傾斜角及び第２側面３４ｂの傾斜角は、例えば０°以上２５°以下の範囲である。言い換えると、凸部３４の断面形状である略台形又は略三角形の２つの底角はそれぞれ、６５°以上９０°以下である。あるいは、２つの底角の少なくとも一方は、６５°より小さくてもよい。第１側面３４ａの傾斜角と第２側面３４ｂの傾斜角とは、互いに異なっていてもよく、等しくてもよい。 The inclination angle of the first side surface 34a and the inclination angle of the second side surface 34b are, for example, in the range of 0 ° to 25 °. In other words, the two base angles of the substantially trapezoidal shape or the substantially triangular shape which are the cross-sectional shape of the convex portion 34 are 65 ° or more and 90 ° or less, respectively. Alternatively, at least one of the two base angles may be smaller than 65 °. The inclination angle of the first side surface 34a and the inclination angle of the second side surface 34b may be different from each other or may be the same.
　複数の凸部３４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３４の間隔は、例えば、０μｍ～１００μｍであるが、これに限らない。 The width (length in the z-axis direction) of the plurality of convex portions 34 is, for example, 1 μm to 20 μm, and preferably 10 μm or less, but is not limited thereto. Further, the interval between two adjacent convex portions 34 is, for example, 0 μm to 100 μm, but is not limited thereto.
　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台形の凹凸構造を、モールド型押しにより形成することができる。 As the material of the concavo-convex structure layer 31, for example, a resin material having optical transparency 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. For example, the concavo-convex structure layer 31 can form a concavo-convex structure having a trapezoidal cross section by mold pressing using an acrylic resin having a refractive index of 1.5 for green light.
　なお、複数の凸部３４は、図３Ｂに示される凸部１３４のように、ｘ軸方向に沿って蛇行しながら延びていてもよい。図３Ｂは、本実施の形態の変形例に係る配光制御デバイス１０１の複数の凸部１３４の平面視形状を模式的に示す平面図である。 In addition, the some convex part 34 may extend, meandering along the x-axis direction like the convex part 134 shown by FIG. 3B. FIG. 3B is a plan view schematically showing a planar view shape of the plurality of convex portions 134 of the light distribution control device 101 according to the modification of the present embodiment.
　図３Ｂに示されるように、複数の凸部１３４は、第１基板１０を平面視した場合に、ｘ軸方向に延びる複数の波線を成すように設けられている。なお、ｘ軸方向は、複数の凸部１３４の並び方向（ｚ軸方向）に直交する方向である。例えば、複数の凸部１３４は、波線のストライプ状に形成されていてもよい。 3B, the plurality of convex portions 134 are provided so as to form a plurality of wavy lines extending in the x-axis direction when the first substrate 10 is viewed in plan. Note that the x-axis direction is a direction orthogonal to the arrangement direction (z-axis direction) of the plurality of convex portions 134. For example, the plurality of convex portions 134 may be formed in a wavy stripe shape.
　複数の波線は、例えば、正弦波又は三角波であるが、これに限らない。例えば、複数の波線はそれぞれ、複数の円弧又は楕円弧が連結された波線であってもよい。また、複数の波線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。波線の山及び谷のｘ軸方向における位置は、波線毎に異なっていてもよい。 The plurality of wavy lines are, for example, a sine wave or a triangular wave, but are not limited thereto. For example, each of the plurality of wavy lines may be a wavy line in which a plurality of arcs or elliptical arcs are connected. The shape and size of each of the plurality of wavy lines are the same as each other, but may be different. The positions of the crests and troughs in the x-axis direction may be different for each wavy line.
　［屈折率可変層］
　屈折率可変層３２は、複数の凸部３４の間（すなわち、凹部３５）を充填するように設けられている。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。なお、図２に示されるように、凸部３４の先端部と第２電極層５０とが離れている場合、屈折率可変層３２は、凹部３５だけでなく、凸部３４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。 [Refractive index variable layer]
The refractive index variable layer 32 is provided so as to fill a space between the plurality of convex portions 34 (that is, the concave portion 35). 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. As shown in FIG. 2, when the tip of the convex portion 34 and the second electrode layer 50 are separated from each other, the refractive index variable layer 32 includes not only the concave portion 35 but also the tip of the convex portion 34 and the second electrode layer 50. It arrange | positions so that the clearance gap between the 2 electrode layers 50 may be filled.
　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、電極間に電圧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。例えば、制御装置（図示せず）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 refractive index variable layer 32 changes depending on 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 capable of adjusting the refractive index in the visible light band when a voltage is applied between the electrodes. For example, a DC voltage is applied between the first electrode layer 40 and the second electrode layer 50 by a control device (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３６と、絶縁性液体３６に含まれるナノ粒子３７とを有する。屈折率可変層３２は、無数のナノ粒子３７が絶縁性液体３６に分散されたナノ粒子分散層である。 2, the refractive index variable layer 32 includes an insulating liquid 36 and nanoparticles 37 included in the insulating liquid 36. The refractive index variable layer 32 is a nanoparticle dispersion layer in which countless nanoparticles 37 are dispersed in the insulating liquid 36.
　絶縁性液体３６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３７が分散される分散媒となる溶媒である。絶縁性液体３６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３６を用いている。 The insulating liquid 36 is a transparent liquid having insulating properties and is a solvent serving as a dispersion medium in which the nanoparticles 37 are dispersed as a dispersoid. As the insulating liquid 36, 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 36 having a refractive index of about 1.4 is used.
　なお、絶縁性液体３６の動粘度は、１００ｍｍ２／ｓ程度であるとよい。また、絶縁性液体３６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３６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３６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３６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 36 is preferably about 100 mm 2 / s. The insulating liquid 36 has a low dielectric constant (for example, less than the dielectric constant of the concavo-convex structure layer 31), non-flammability (for example, a high flash point having a flash point of 250 ° C. or higher) and low volatility. Also good. Specifically, the insulating liquid 36 is a hydrocarbon such as an aliphatic hydrocarbon, naphtha, and other petroleum solvents, a low molecular weight halogen-containing polymer, or a mixture thereof. As an example, the insulating liquid 36 is a halogenated hydrocarbon such as a fluorinated hydrocarbon. As the insulating liquid 36, silicone oil or the like can be used.
　ナノ粒子３７は、絶縁性液体３６に複数分散されている。ナノ粒子３７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３７の粒径は、λ／４以下であるとよい。ナノ粒子３７の粒径をλ／４以下にすることで、ナノ粒子３７による光散乱を少なくして、ナノ粒子３７と絶縁性液体３６との平均的な屈折率を得ることができる。ナノ粒子３７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 37 are dispersed in the insulating liquid 36. The nanoparticles 37 are fine particles having a particle size of nano-order size. Specifically, when the wavelength of incident light is λ, the particle size of the nanoparticles 37 is preferably λ / 4 or less. By setting the particle size of the nanoparticles 37 to λ / 4 or less, light scattering by the nanoparticles 37 can be reduced, and an average refractive index of the nanoparticles 37 and the insulating liquid 36 can be obtained. The particle size of the nanoparticles 37 is preferably as small as possible, preferably 100 nm or less, more preferably several nm to several tens nm.
　ナノ粒子３７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３７の屈折率は、絶縁性液体３６の屈折率よりも高い。本実施の形態において、ナノ粒子３７の屈折率は、凹凸構造層３１の屈折率よりも高い。 The nanoparticles 37 are made of, for example, a high refractive index material. Specifically, the refractive index of the nanoparticles 37 is higher than the refractive index of the insulating liquid 36. In the present embodiment, the refractive index of the nanoparticles 37 is higher than the refractive index of the concavo-convex structure layer 31.
　ナノ粒子３７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３７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３７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３７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。 As the nanoparticles 37, for example, metal oxide fine particles can be used. The nanoparticles 37 may be made of a material having a high transmittance. In the present embodiment, transparent zirconia particles having a refractive index of 2.1 composed of zirconium oxide (ZrO 2 ) are used as the nanoparticles 37. The nanoparticles 37 are not limited to zirconium oxide, and may be composed of titanium oxide (TiO 2 : refractive index 2.5) or the like.
　また、ナノ粒子３７は、帯電している荷電粒子である。例えば、ナノ粒子３７の表面を修飾することで、ナノ粒子３７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３７は、正（プラス）に帯電している。 Further, the nanoparticles 37 are charged particles that are charged. For example, by modifying the surface of the nanoparticles 37, the nanoparticles 37 can be charged positively (plus) or negatively (minus). In the present embodiment, the nanoparticles 37 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３７が絶縁性液体３６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３７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３６に分散させたものを屈折率可変層３２としている。 In the refractive index variable layer 32 configured in this way, charged nanoparticles 37 are dispersed throughout the insulating liquid 36. In the present embodiment, as an example, the refractive index variable layer 32 is obtained by dispersing zirconia particles having a refractive index of 2.1 as nanoparticles 37 and dispersing them in an insulating liquid 36 having a solvent refractive index of about 1.4. It is said.
　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３７が絶縁性液体３６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３６に分散するナノ粒子３７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３７の量は、例えば、凹凸構造層３１の凹部３５に埋まる程度である。この場合、絶縁性液体３６に対するナノ粒子３７の濃度は、約１０％～約３０％である。 The overall refractive index (average refractive index) of the refractive index variable layer 32 is set to be approximately the same as the refractive index of the concavo-convex structure layer 31 in a state where the nanoparticles 37 are uniformly dispersed in the insulating liquid 36. In this embodiment, it is about 1.5. The overall refractive index of the refractive index variable layer 32 can be changed by adjusting the concentration (amount) of the nanoparticles 37 dispersed in the insulating liquid 36. Although details will be described later, the amount of the nanoparticles 37 is, for example, such that it is buried in the recesses 35 of the uneven structure layer 31. In this case, the concentration of the nanoparticles 37 with respect to the insulating liquid 36 is about 10% to about 30%.
　絶縁性液体３６中に分散するナノ粒子３７は帯電しているので、第１電極層４０及び第２電極層５０間に電圧が印加された場合、ナノ粒子３７は、ナノ粒子３７が帯びた極性とは異なる極性の電極層に引き寄せられるように絶縁性液体３６中を泳動し、絶縁性液体３６内で偏在する。本実施の形態では、ナノ粒子３７は、プラスに帯電しているので、第１電極層４０及び第２電極層５０のうち負極側の電極層に引き寄せられる。 Since the nanoparticles 37 dispersed in the insulating liquid 36 are charged, when a voltage is applied between the first electrode layer 40 and the second electrode layer 50, the nanoparticles 37 have a polarity with which the nanoparticles 37 are charged. Electrophoreses in the insulating liquid 36 so as to be attracted to the electrode layer having a polarity different from that of the electrode layer and is unevenly distributed in the insulating liquid 36. In the present embodiment, since the nanoparticles 37 are positively charged, they are attracted to the negative electrode layer of the first electrode layer 40 and the second electrode layer 50.
　これにより、屈折率可変層３２内のナノ粒子３７の粒子分布が変化して屈折率可変層３２内にナノ粒子３７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。 As a result, the particle distribution of the nanoparticles 37 in the refractive index variable layer 32 can be changed to give the concentration distribution of the nanoparticles 37 in the refractive index variable layer 32, so that the refractive index in the refractive index variable layer 32 can be obtained. Distribution changes. That is, the refractive index of the refractive index variable layer 32 partially changes. Thus, the refractive index variable layer 32 mainly functions as a refractive index adjustment layer that can adjust the refractive index for 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電極層５０が形成された第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３７が分散された絶縁性液体３６である。ナノ粒子３７が分散された絶縁性液体３６が第１基板１０と第２基板２０との間に封止されている。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。 The refractive index variable layer 32 includes, for example, 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 is formed by injecting a refractive index variable material by a vacuum injection method while being sealed with a seal resin. Alternatively, the refractive index variable layer 32 is 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 attaching the second substrate 20 on which the second electrode layer 50 is formed. You may form by combining. In the present embodiment, the refractive index variable material is an insulating liquid 36 in which nanoparticles 37 are dispersed. An insulating liquid 36 in which nanoparticles 37 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 μm to 1000 μm, but is not limited thereto.
　［遮光部］
　遮光部３３は、入射した光の少なくとも一部を遮光する。なお、本明細書において、「遮光」とは、入射した光を完全に遮断することだけでなく、一部のみを遮断し、残りを透過させることも意味する。例えば、「遮光」は、光の透過よりも遮断が支配的な状態を言う。具体的には、遮光部３３の可視光に対する透過率は、５０％より低く、好ましくは、２０％以下、又は、１０％以下でもよい。 [Shading section]
The light shielding unit 33 shields at least part of the incident light. In the present specification, “shielding” means not only completely blocking incident light but also blocking only a part and transmitting the rest. For example, “light blocking” refers to a state where blocking is more dominant than light transmission. Specifically, the transmittance for visible light of the light-shielding portion 33 is lower than 50%, preferably 20% or less, or 10% or less.
　本実施の形態では、遮光部３３は、凹部３５の底に設けられた遮光膜である。具体的には、遮光部３３は、凹凸構造層３１と同様に、ｘ軸方向に延びるストライプ状に形成されている。本実施の形態では、全ての凹部３５に遮光部３３が設けられているが、これに限らない。例えば、ｚ軸方向に沿って複数の凹部３５のｎ個置き（ｎは１以上の自然数）に遮光部３３が設けられていてもよい。 In the present embodiment, the light shielding portion 33 is a light shielding film provided on the bottom of the recess 35. Specifically, like the concavo-convex structure layer 31, the light shielding portion 33 is formed in a stripe shape extending in the x-axis direction. In the present embodiment, the light shielding portions 33 are provided in all the concave portions 35, but the present invention is not limited to this. For example, the light-shielding part 33 may be provided every n pieces (n is a natural number of 1 or more) of the plurality of recesses 35 along the z-axis direction.
　遮光部３３は、例えば、黒色顔料を含んでいる。黒色顔料としては、例えば、カーボンブラックなどの炭素系黒色顔料、又は、酸化物系黒色顔料などを用いることができる。例えば、黒色水性インクを凹部３５内にバーコーターを用いて塗布した後、１００℃の環境下で乾燥させる。 The light shielding part 33 includes, for example, a black pigment. As the black pigment, for example, a carbon black pigment such as carbon black or an oxide black pigment can be used. For example, black aqueous ink is applied in the recesses 35 using a bar coater and then dried in an environment of 100 ° C.
　遮光部３３の透過率は、使用する黒色水性インクの濃度（具体的には、黒色顔料の量）と、塗布回数とで調整することができる。具体的には、インクの濃度を濃く、又は、塗布回数を多くすることで、遮光部３３の透過率を低く（すなわち、光を通過させにくく）することができる。 The transmittance of the light shielding part 33 can be adjusted by the concentration of black aqueous ink to be used (specifically, the amount of black pigment) and the number of coatings. Specifically, the transmittance of the light shielding portion 33 can be lowered (that is, it is difficult for light to pass through) by increasing the concentration of ink or increasing the number of times of application.
　遮光部３３の幅（ｚ軸方向）は、凹部３５の幅、すなわち、隣り合う凸部３４間の距離である。例えば、遮光部３３の幅は、０μｍ～１００μｍである。遮光部３３の幅は、凸部３４の根元部の厚さ（台形の下底）より小さい。具体的には、遮光部３３の幅は、凸部３４の根元部の厚さの５分の１以下であり、例えば２μｍである。 The width (z-axis direction) of the light shielding portion 33 is the width of the concave portion 35, that is, the distance between the adjacent convex portions 34. For example, the width of the light shielding portion 33 is 0 μm to 100 μm. The width of the light shielding part 33 is smaller than the thickness of the base part of the convex part 34 (the bottom of the trapezoid). Specifically, the width of the light shielding portion 33 is equal to or less than one fifth of the thickness of the root portion of the convex portion 34, for example, 2 μm.
　本実施の形態では、遮光部３３は、導電性を有する。具体的には、遮光部３３の電気抵抗値は、絶縁性液体３６の電気抵抗値より小さく、第１電極層４０の電気抵抗値以上である。例えば、遮光部３３のシート抵抗は、１００ｋΩ／ｓｑ以下である。なお、遮光部３３のシート抵抗は、１０ｋΩ／ｓｑ以下でもよく、１ｋΩ／ｓｑ以下でもよい。例えば、遮光部３３は、導電性のカーボンブラックを含むことにより導電性を有する。 In the present embodiment, the light shielding portion 33 has conductivity. Specifically, the electrical resistance value of the light shielding part 33 is smaller than the electrical resistance value of the insulating liquid 36 and is equal to or greater than the electrical resistance value of the first electrode layer 40. For example, the sheet resistance of the light shielding part 33 is 100 kΩ / sq or less. In addition, the sheet resistance of the light shielding part 33 may be 10 kΩ / sq or less, or 1 kΩ / sq or less. For example, the light shielding part 33 has conductivity by including conductive carbon black.
　遮光部３３は、例えば、第１電極層４０と屈折率可変層３２との両方に接触している。遮光部３３は、第１電極層４０と略同じ電位になる。このため、屈折率可変層３２に含まれるナノ粒子３７は、絶縁性液体３６が接触している遮光部３３に引き寄せられやすくなる。遮光部３３が導電性を有することで、第１電極層４０及び第２電極層５０間に電流を流すことができる。これにより、ナノ粒子３７の泳動がスムーズに行われ、屈折率可変層３２の屈折率分布を異ならせることができる。 The light shielding part 33 is in contact with both the first electrode layer 40 and the refractive index variable layer 32, for example. The light shielding part 33 has substantially the same potential as the first electrode layer 40. For this reason, the nanoparticles 37 contained in the refractive index variable layer 32 are easily attracted to the light shielding portion 33 with which the insulating liquid 36 is in contact. Since the light shielding part 33 has conductivity, a current can flow between the first electrode layer 40 and the second electrode layer 50. Thereby, the migration of the nanoparticles 37 can be performed smoothly, and the refractive index distribution of the refractive index variable layer 32 can be made different.
　本実施の形態では、遮光部３３は、略均一な膜厚で形成されている。遮光部３３の膜厚（ｙ軸方向）は、例えば２００ｎｍ～１μｍである。 In the present embodiment, the light shielding part 33 is formed with a substantially uniform film thickness. The thickness (y-axis direction) of the light shielding part 33 is, for example, 200 nm to 1 μm.
　あるいは、遮光部３３は、図４に示される遮光部２３３のように、膜厚が均一でなくてもよい。図４は、本実施の形態の変形例に係る配光制御デバイス２０１の一部を拡大して示す拡大断面図である。 Alternatively, the film thickness of the light shielding part 33 may not be uniform like the light shielding part 233 shown in FIG. FIG. 4 is an enlarged cross-sectional view showing a part of a light distribution control device 201 according to a modification of the present embodiment.
　図４に示す配光制御デバイス２０１は、配光層３０の代わりに配光層２３０を備える。配光層２３０は、遮光部３３の代わりに遮光部２３３を備える。 4 includes a light distribution layer 230 instead of the light distribution layer 30. The light distribution control device 201 illustrated in FIG. The light distribution layer 230 includes a light shielding unit 233 instead of the light shielding unit 33.
　図４に示されるように、遮光部２３３の両端部の膜厚は、遮光部２３３の中央部の膜厚より大きい。具体的には、遮光部２３３と屈折率可変層３２との界面は、凹状に凹んでいる。例えば、遮光部２３３と屈折率可変層３２との界面は、湾曲した曲面を有する。 As shown in FIG. 4, the film thickness at both ends of the light shielding part 233 is larger than the film thickness at the central part of the light shielding part 233. Specifically, the interface between the light shielding part 233 and the refractive index variable layer 32 is recessed in a concave shape. For example, the interface between the light shielding part 233 and the refractive index variable layer 32 has a curved surface.
　遮光部２３３は、例えば、黒色顔料を含むインクを乾燥させることにより形成される。このとき、第１基板１０が鉛直下方側（すなわち、ｙ軸の正方向を鉛直上方）になる姿勢でインクを塗布して乾燥させた場合に、インクの自重及び表面張力により、凹面が自然に形成される。あるいは、均一な膜厚の遮光部３３を形成した後、遮光部３３の中央部をエッチングなどにより削ることで、遮光部２３３を形成してもよい。 The light shielding part 233 is formed by drying ink containing a black pigment, for example. At this time, when the ink is applied and dried in a posture in which the first substrate 10 is vertically downward (that is, the positive direction of the y axis is vertically upward), the concave surface is naturally formed by the weight of the ink and the surface tension. It is formed. Alternatively, the light shielding part 233 may be formed by forming the light shielding part 33 with a uniform film thickness and then shaving the central part of the light shielding part 33 by etching or the like.
　なお、遮光部３３及び２３３は、黒色でなくてもよい。例えば、遮光部３３及び２３３は、有色顔料を含む溶剤インクを乾燥させたものでもよい。乾燥は、自然乾燥でもよい。 Note that the light shielding portions 33 and 233 may not be black. For example, the light shielding portions 33 and 233 may be obtained by drying a solvent ink containing a colored pigment. Drying may be natural drying.
　［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. The first electrode layer 40 and the second electrode layer 50 are paired not only electrically but also in arrangement, and are arranged 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 arranged so as 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 are translucent and transmit incident light. The first electrode layer 40 and the second electrode layer 50 are, for example, transparent conductive layers. As a material for the transparent conductive layer, a conductor-containing resin made of a resin containing a conductor such as a transparent metal oxide such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), silver nanowires or conductive particles, or A metal thin film such as a silver thin film can be used. In addition, the 1st electrode layer 40 and the 2nd electrode layer 50 may be these single layer structures, and these laminated structures (for example, laminated structure of a transparent metal oxide and a metal thin film) may be sufficient as them. 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。 In addition, the 1st electrode layer 40 and the 2nd electrode layer 50 are comprised so that electrical connection with an external power supply is attained, for example. For example, electrode pads or the like for connecting to an external power source may be formed on the first substrate 10 and the second substrate 20 by being drawn from each of the first electrode layer 40 and the second electrode layer 50.
　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 forming a conductive film such as ITO by vapor deposition, sputtering, or the like, for example.
　［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]
Next, the operation and optical state of the light distribution control device 1 will be described.
　＜透明状態（無印加モード）＞
　図５Ａ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。また、図５Ａには、配光制御デバイス１に対して斜めに入射する光Ｌ１及び光Ｌ２の経路を矢印で示している。 <Transparent state (non-application mode)>
FIG. 5A is an enlarged cross-sectional view for explaining a non-application mode (transparent state) of the light distribution control device 1 according to the present embodiment. Further, in FIG. 5A, the paths of the light L1 and the light L2 that enter the light distribution control device 1 obliquely are indicated by arrows.
　図５Ａ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、ナノ粒子３７は、いずれの電極層にも引き寄せられないので、絶縁性液体３６の全体に亘って分散された状態となる。 In FIG. 5A, 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 equipotential with each other. In this case, since the nanoparticles 37 are not attracted to any electrode layer, the nanoparticles 37 are dispersed throughout the insulating liquid 36.
　本実施の形態では、ナノ粒子３７が絶縁性液体３６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３４の屈折率は、約１．５である。つまり、複数の凸部３４と、屈折率可変層３２とは、屈折率が同等になる。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 refractive index variable layer 32 in a state where the nanoparticles 37 are dispersed throughout the insulating liquid 36 is about 1.5 as described above. Moreover, the refractive index of the convex part 34 of the concavo-convex structure layer 31 is about 1.5. That is, the plurality of convex portions 34 and the refractive index variable layer 32 have the same refractive index. Therefore, the refractive index is uniform throughout the light distribution layer 30.
　このため、図５Ａに示されるように、斜め上方から斜め下方に向けて光Ｌ１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。つまり、ｙｚ断面において、光Ｌ１の入射角と出射角とは、実質的に同じになる。 For this reason, as shown in FIG. 5A, when the light L1 is incident from obliquely upward to obliquely downward, there is no difference in refractive index at the interface between the refractive index variable layer 32 and the concavo-convex structure layer 31, Proceed straight. That is, in the yz section, the incident angle and the exit angle of the light L1 are substantially the same.
　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。 Thus, the light distribution control device 1 is in a transparent state that allows the incident light to pass through substantially as it is (without changing the traveling direction).
　なお、光Ｌ１は、実際には、第１基板１０に入射するとき、第２基板２０から出射するとき、第１基板１０と第１電極層４０との界面を通過するとき、及び、第２電極層５０と第２基板２０との界面を通過するとき、などの通過する媒体が変化するときに屈折するが、図５Ａには図示していない。後述する図５Ｂにおいても同様である。 The light L1 is actually incident on the first substrate 10, emitted from the second substrate 20, passed through the interface between the first substrate 10 and the first electrode layer 40, and the second. Although it is refracted when the passing medium changes, such as when passing through the interface between the electrode layer 50 and the second substrate 20, it is not shown in FIG. 5A. The same applies to FIG. 5B described later.
　＜配光状態（電圧印加モード）＞
　図５Ｂは、本実施の形態に係る配光制御デバイス１の電圧印加モード（配光状態）を説明するための拡大断面図である。また、図５Ｂには、配光制御デバイス１に対して斜めに入射する光Ｌ１及び光Ｌ２の経路を太線の矢印で示している。 <Light distribution state (voltage application mode)>
FIG. 5B is an enlarged cross-sectional view for explaining a voltage application mode (light distribution state) of the light distribution control device 1 according to the present embodiment. Further, in FIG. 5B, the paths of the light L1 and the light L2 that are obliquely incident on the light distribution control device 1 are indicated by thick arrows.
　図５Ｂにおいて、第１電極層４０及び第２電極層５０間に所定の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程度の電位差の電圧が印加されている。これにより、屈折率可変層３２では、帯電したナノ粒子３７が、ナノ粒子３７が帯びた極性とは異なる極性の電極層に引き寄せられるように絶縁性液体３６内を泳動する。つまり、ナノ粒子３７は、絶縁性液体３６内を電気泳動する。 In FIG. 5B, a predetermined voltage is applied between the first electrode layer 40 and the second electrode layer 50. For example, a 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. Thereby, in the refractive index variable layer 32, the charged nanoparticles 37 migrate in the insulating liquid 36 so as to be attracted to the electrode layer having a polarity different from the polarity of the nanoparticles 37. That is, the nanoparticles 37 are electrophoresed in the insulating liquid 36.
　図５Ｂ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３７は、第１電極層４０に向かって泳動し、凹凸構造層３１の凹部３５に入り込んで集積していく。 In the example shown in FIG. 5B, the second electrode layer 50 has a higher potential than the first electrode layer 40. For this reason, the positively charged nanoparticles 37 migrate toward the first electrode layer 40 and enter the concave portion 35 of the concave-convex structure layer 31 and accumulate.
　このように、ナノ粒子３７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３７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５Ｂに示すように、屈折率可変層３２内でナノ粒子３７の濃度分布が形成される。 As described above, the nanoparticles 37 are unevenly distributed on the uneven structure layer 31 side in the refractive index variable layer 32, whereby the particle distribution of the nanoparticles 37 is changed and the refractive index distribution in the refractive index variable layer 32 is not uniform. Disappear. Specifically, as shown in FIG. 5B, a concentration distribution of nanoparticles 37 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３７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３７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 32a on the uneven structure layer 31 side, the concentration of the nanoparticles 37 is high, and in the second region 32b on the second electrode layer 50 side, the concentration of the nanoparticles 37 is low. Accordingly, a difference in refractive index occurs between the first region 32a and the second region 32b.
　本実施の形態では、ナノ粒子３７の屈折率が絶縁性液体３６の屈折率よりも高い。このため、ナノ粒子３７の濃度が高い第１領域３２ａの屈折率は、ナノ粒子３７の濃度が低い、すなわち、絶縁性液体３６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３７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３７の濃度に応じて約１．４～約１．５より小さい値になる。 In this embodiment, the refractive index of the nanoparticles 37 is higher than the refractive index of the insulating liquid 36. For this reason, the refractive index of the first region 32a in which the concentration of the nanoparticles 37 is high is higher than the refractive index of the second region 32b in which the concentration of the nanoparticles 37 is low, that is, the proportion of the insulating liquid 36 is large. For example, the refractive index of the first region 32a is greater than about 1.5 to about 1.8 depending on the concentration of the nanoparticles 37. The refractive index of the second region 32 b becomes a value less than about 1.4 to less than about 1.5 depending on the concentration of the nanoparticles 37.
　複数の凸部３４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３４と第１領域３２ａとの間には、屈折率差が生じる。このため、図５Ｂに示すように、斜め方向から光Ｌ１が入射した場合、入射した光Ｌ１は、凸部３４の第１側面３４ａで屈折した後、第２側面３４ｂで全反射される。 Since the refractive index of the plurality of protrusions 34 is about 1.5, when a voltage is applied between the first electrode layer 40 and the second electrode layer 50, the protrusion 34 and the first region 32a There is a difference in refractive index between them. Therefore, as shown in FIG. 5B, when the light L1 is incident from an oblique direction, the incident light L1 is refracted by the first side surface 34a of the convex portion 34 and then totally reflected by the second side surface 34b.
　これにより、図５Ｂに示されるように、垂直断面において、光Ｌ１の入射角と出射角とが異なる。例えば、斜め上方から斜め下方に向けて入射した光Ｌ１は、斜め上方に向けて配光制御デバイス１から出射される。 Thereby, as shown in FIG. 5B, the incident angle and the emission angle of the light L1 are different in the vertical cross section. For example, the light L1 incident from diagonally upward to diagonally downward is emitted from the light distribution control device 1 diagonally upward.
　このように、第１電極層４０と第２電極層５０との間に所定の電圧が印加された場合に、複数の凸部３４の各々と屈折率可変層３２との界面に屈折率差が発生し、配光層３０に入射する光の進行方向が曲げられる。つまり、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。 As described above, when a predetermined voltage is applied between the first electrode layer 40 and the second electrode layer 50, there is a difference in refractive index at the interface between each of the plurality of convex portions 34 and the refractive index variable layer 32. The traveling direction of the light generated and incident on the light distribution layer 30 is bent. That is, the light distribution control device 1 enters a light distribution state in which incident light is transmitted with its traveling direction bent.
　また、印加する電圧の大きさによってナノ粒子３７の凝集の程度を変化させることができる。ナノ粒子３７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３４の第１側面３４ａ及び第２側面３４ｂ（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。 Also, the degree of aggregation of the nanoparticles 37 can be changed according to the magnitude of the applied voltage. The refractive index of the refractive index variable layer 32 changes depending on the degree of aggregation of the nanoparticles 37. For this reason, it is also possible to change the light distribution direction by changing the difference in refractive index between the first side surface 34 a and the second side surface 34 b (interface) of the convex portion 34.
　［遮光部の光学的な機能］
　続いて、配光制御デバイス１の遮光部３３の光学的な機能について、本実施の形態に至る経緯も含めて説明する。 [Optical function of shading part]
Next, the optical function of the light shielding unit 33 of the light distribution control device 1 will be described including the background to the present embodiment.
　図６は、従来の配光制御デバイス１ｘで発生する光の筋の一要因を説明するための拡大断面図である。図６に示す配光制御デバイス１ｘは、実施の形態に係る図２に示す配光制御デバイス１と比較して、遮光部３３が設けられていない点が相違する。なお、図６では、配光制御デバイス１ｘが配光モードである場合を示している。具体的には、配光層３０ｘの屈折率可変層３２の第１領域３２ａの屈折率が、凸部３４の屈折率より大きくなっている。 FIG. 6 is an enlarged cross-sectional view for explaining one factor of light streaks generated in the conventional light distribution control device 1x. The light distribution control device 1x illustrated in FIG. 6 is different from the light distribution control device 1 illustrated in FIG. 2 according to the embodiment in that the light shielding unit 33 is not provided. FIG. 6 shows a case where the light distribution control device 1x is in the light distribution mode. Specifically, the refractive index of the first region 32 a of the refractive index variable layer 32 of the light distribution layer 30 x is larger than the refractive index of the convex portion 34.
　このとき、第１電極層４０から配光層３０ｘの凹部３５に入射する光Ｌ３は、第１電極層４０と配光層３０ｘとの屈折率の差によって、光が部分的に散乱する（図６に示す散乱光Ｌｘ）。散乱光の多くは、ｙｚ平面内において進行する光であるため、ｚ軸方向に沿った光の筋となって現れる。これにより、配光制御デバイス１ｘを正面から見る人にとっては、ライン状の局所的な眩しさが感じられる。 At this time, the light L3 incident on the concave portion 35 of the light distribution layer 30x from the first electrode layer 40 is partially scattered by the difference in refractive index between the first electrode layer 40 and the light distribution layer 30x (see FIG. Scattered light Lx shown in FIG. Most of the scattered light is light traveling in the yz plane, and thus appears as a streak of light along the z-axis direction. Thereby, for the person who sees the light distribution control device 1x from the front, a linear local glare is felt.
　これに対して、本実施の形態に係る配光制御デバイス１では、図２などに示されるように、凹凸構造層３１の凹部３５に遮光部３３が設けられている。 On the other hand, in the light distribution control device 1 according to the present embodiment, as shown in FIG. 2 and the like, the light shielding portion 33 is provided in the concave portion 35 of the concave-convex structure layer 31.
　図５Ａ及び図５Ｂに示すように、配光制御デバイス１に対して斜めに入射する光のうち、遮光部３３に入射する光Ｌ２は、遮光部３３によって遮光される。これにより、図６で示したような散乱光Ｌｘの発生が抑制される。散乱光Ｌｘの各々の強度は、光Ｌ１の主成分に比べて弱いので、遮光部３３によって十分に減衰される。配光状態及び透明状態のいずれの場合も、光Ｌ２は、遮光部３３によって遮光される。 As shown in FIGS. 5A and 5B, the light L <b> 2 incident on the light shielding part 33 among the light obliquely incident on the light distribution control device 1 is shielded by the light shielding part 33. Thereby, generation | occurrence | production of the scattered light Lx as shown in FIG. 6 is suppressed. Since each intensity of the scattered light Lx is weaker than the main component of the light L1, it is sufficiently attenuated by the light shielding unit 33. In both the light distribution state and the transparent state, the light L <b> 2 is blocked by the light blocking unit 33.
　本実施の形態では、遮光部３３の幅（ｚ軸方向）は、凸部３４の根元部の幅よりも小さいので、遮光部３３によって遮光される光Ｌ２の光量は、凸部３４を通過する光Ｌ１の光量よりも少ない。したがって、配光制御デバイス１は、配光制御デバイス１に入射する光の大部分（例えば、８０％）以上を透過させることができる。 In the present embodiment, since the width (z-axis direction) of the light shielding portion 33 is smaller than the width of the root portion of the convex portion 34, the light amount of the light L2 shielded by the light shielding portion 33 passes through the convex portion 34. Less than the amount of light L1. Therefore, the light distribution control device 1 can transmit most (for example, 80%) or more of light incident on the light distribution control device 1.
　なお、上述したように、遮光部３３は、光Ｌ２の一部を透過してもよい。この場合、配光状態の場合は、光Ｌ２の透過光は、光Ｌ１と同様に、凸部３４の第２側面３４ｂによって反射されて、斜め上方に向けて第２基板２０から出射される。また、透明状態の場合は、光Ｌ２の透過光は、光Ｌ１と同様に、そのまま真っ直ぐ配光制御デバイス１を透過する。 Note that, as described above, the light shielding unit 33 may transmit a part of the light L2. In this case, in the light distribution state, the transmitted light of the light L2 is reflected by the second side surface 34b of the convex portion 34 and emitted from the second substrate 20 obliquely upward, similarly to the light L1. Further, in the transparent state, the transmitted light of the light L2 passes through the light distribution control device 1 as it is, as with the light L1.
　［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、並んで配置された複数の凸部３４を有する凹凸構造層３１と、複数の凸部３４間である凹部３５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、凹部３５に設けられた、入射した光の少なくとも一部を遮光する遮光部３３とを含む。屈折率可変層３２は、絶縁性液体３６と、絶縁性液体３６とは屈折率が異なる、絶縁性液体３６に分散された帯電する複数のナノ粒子３７とを備える。遮光部３３は、導電性を有する。 [Effects, etc.]
As described above, the light distribution control device 1 according to the present embodiment includes the first substrate 10 having translucency, and the second substrate 20 having translucency disposed so as to face the first substrate 10. And the first electrode layer 40 and the second electrode layer 50 having translucency, which are disposed opposite to each other between the first substrate 10 and the second substrate 20, and the first electrode layer 40 and the second electrode. The light distribution layer 30 is disposed between the layer 50 and distributes incident light. The light distribution layer 30 is disposed so as to fill the concavo-convex structure layer 31 having the plurality of convex portions 34 arranged side by side and the concave portion 35 between the plurality of convex portions 34, and the first electrode layer 40 and the second electrode layer 40. It includes a refractive index variable layer 32 whose refractive index changes according to the voltage applied between the electrode layers 50, and a light shielding portion 33 provided in the concave portion 35 for shielding at least part of incident light. The refractive index variable layer 32 includes an insulating liquid 36 and a plurality of charged nanoparticles 37 dispersed in the insulating liquid 36 having a refractive index different from that of the insulating liquid 36. The light shielding part 33 has conductivity.
　これにより、凹部３５に遮光部３３が設けられているので、凹部３５で発生する散乱光を抑制することができる。したがって、光の筋の発生が抑制され、局所的な眩しさが軽減される。 Thereby, since the light shielding portion 33 is provided in the concave portion 35, the scattered light generated in the concave portion 35 can be suppressed. Therefore, generation of light streaks is suppressed and local glare is reduced.
　また、遮光部３３が導電性を有するので、屈折率可変層３２に含まれる帯電性のナノ粒子３７の電気泳動を起こさせることができる。具体的には、第１電極層４０及び第２電極層５０間に電圧が印加された場合に、遮光部３３は、第１電極層４０と同じ極性を有する。したがって、絶縁性液体３６に分散された複数のナノ粒子３７は、絶縁性液体３６に接触している遮光部３３に引き寄せられやすくなる。このため、例えば、複数のナノ粒子３７が遮光部３３に引き寄せられて凹部３５内に集積することで、凸部３４と屈折率可変層３２との屈折率差が発生する。当該屈折率差によって、入射した光を屈折又は反射させることで、光の進行方向を曲げることができる。 In addition, since the light shielding portion 33 has conductivity, electrophoresis of the charged nanoparticles 37 included in the refractive index variable layer 32 can be caused. Specifically, when a voltage is applied between the first electrode layer 40 and the second electrode layer 50, the light shielding unit 33 has the same polarity as the first electrode layer 40. Therefore, the plurality of nanoparticles 37 dispersed in the insulating liquid 36 are easily attracted to the light shielding portion 33 that is in contact with the insulating liquid 36. For this reason, for example, a plurality of nanoparticles 37 are attracted to the light shielding portion 33 and accumulated in the concave portion 35, thereby generating a refractive index difference between the convex portion 34 and the refractive index variable layer 32. The light traveling direction can be bent by refracting or reflecting the incident light by the refractive index difference.
　また、本実施の形態によれば、第１電極層４０及び第２電極層５０に印加する電圧を調整することで、複数の凸部３４と屈折率可変層３２との間の屈折率の差を変化させることができる。例えば、複数の凸部３４と屈折率可変層３２との間の屈折率差を実質的に０にすることで、配光制御デバイス１を透明状態にすることができる。また、複数の凸部３４と屈折率可変層３２との間の屈折率差を大きくすることで、凸部３４と屈折率可変層３２との界面（具体的には、凸部３４の第２側面３４ｂ）を全反射面として機能させることができ、入射光を全反射させて進行方向を曲げることができる。すなわち、配光制御デバイス１を配光状態にすることができる。 Further, according to the present embodiment, the difference in refractive index between the plurality of convex portions 34 and the refractive index variable layer 32 is adjusted by adjusting the voltage applied to the first electrode layer 40 and the second electrode layer 50. Can be changed. For example, the light distribution control device 1 can be made transparent by making the refractive index difference between the plurality of convex portions 34 and the refractive index variable layer 32 substantially zero. Further, by increasing the refractive index difference between the plurality of convex portions 34 and the refractive index variable layer 32, the interface between the convex portions 34 and the refractive index variable layer 32 (specifically, the second of the convex portions 34). The side surface 34b) can be made to function as a total reflection surface, and the traveling direction can be bent by totally reflecting incident light. That is, the light distribution control device 1 can be in a light distribution state.
　以上のように、本実施の形態に係る配光制御デバイス１によれば、局所的な眩しさを軽減することができ、かつ、窓に利用された場合に光を効率良く採り入れることができる。 As described above, according to the light distribution control device 1 according to the present embodiment, local glare can be reduced, and light can be taken in efficiently when used in a window.
　なお、発明者らは、配光制御デバイス１を試作し、第１電極層４０と第２電極層５０との間に所定の電圧を印加した結果、配光制御デバイス１を配光状態にできることを確認できた。また、配光制御デバイス１が配光状態である場合、第１電極層４０と第２電極層５０との間に電流が流れていることが確認された。つまり、本実施の形態に係る配光制御デバイス１は、電流が流れることにより光学状態が変化する電流制御デバイスであると推察される。 The inventors made a prototype of the light distribution control device 1 and applied a predetermined voltage between the first electrode layer 40 and the second electrode layer 50. As a result, the light distribution control device 1 can be in a light distribution state. Was confirmed. In addition, when the light distribution control device 1 is in the light distribution state, it was confirmed that a current flows between the first electrode layer 40 and the second electrode layer 50. That is, it is assumed that the light distribution control device 1 according to the present embodiment is a current control device that changes its optical state when a current flows.
　一方で、遮光部３３が導電性を有しないデバイスを試作し、第１電極層４０と第２電極層５０との間に電流がほとんど流れず、配光状態も得られなかった。このため、遮光部３３が導電性を有しない場合は、電気泳動がほとんど起きず、凹部３５内へのナノ粒子３７の集積による屈折率の変化が起きていないことが分かる。このように、電気泳動を利用した配光制御デバイス１では、遮光部３３を導電性にすることが肝要である。 On the other hand, a device in which the light shielding portion 33 has no conductivity was made as a prototype, and almost no current flowed between the first electrode layer 40 and the second electrode layer 50, and a light distribution state was not obtained. For this reason, when the light-shielding portion 33 does not have conductivity, electrophoresis hardly occurs, and it is understood that the refractive index does not change due to the accumulation of the nanoparticles 37 in the recess 35. Thus, in the light distribution control device 1 using electrophoresis, it is important to make the light shielding portion 33 conductive.
　また、例えば、遮光部３３は、凹部３５の底に設けられた遮光膜である。 For example, the light shielding part 33 is a light shielding film provided on the bottom of the recess 35.
　これにより、遮光部３３と第１電極層４０とを略同じ電位にすることができるので、ナノ粒子３７は、より遮光部３３に引き寄せられやすくなる。したがって、絶縁性液体３６内でのナノ粒子３７の泳動がスムーズに行われ、配光状態及び透明状態の切り替えを速やかに行うことができる。 Thereby, since the light shielding part 33 and the first electrode layer 40 can be set to substantially the same potential, the nanoparticles 37 are more easily attracted to the light shielding part 33. Therefore, the migration of the nanoparticles 37 in the insulating liquid 36 is performed smoothly, and the light distribution state and the transparent state can be quickly switched.
　また、例えば、複数の凸部３４の並び方向において、遮光膜の両端部の膜厚は、遮光膜の中央部の膜厚より大きくてもよい。 Further, for example, in the direction in which the plurality of convex portions 34 are arranged, the film thickness at both ends of the light shielding film may be larger than the film thickness at the center of the light shielding film.
　これにより、図４に示されるように、遮光部２３３の中央部が薄くなるので、中央部の光の透過率が高くなる。したがって、散乱光を遮光しつつ、主な入射光を透過させることができるので、局所的な眩しさを抑制しつつ、採光効率を高めることができる。また、屋内に居る人にとって屋外の視認性を高めることができるので、窓としての本来の機能（すなわち、透明性）を高めることができる。 As a result, as shown in FIG. 4, the central portion of the light shielding portion 233 is thinned, so that the light transmittance at the central portion is increased. Accordingly, since the main incident light can be transmitted while blocking the scattered light, the daylighting efficiency can be increased while suppressing local glare. Moreover, since the visibility of the outdoors can be improved for the person who is indoors, the original function (namely, transparency) as a window can be improved.
　また、例えば、複数の凸部１３４は、第１基板１０を平面視した場合に、複数の凸部１３４の並び方向に直交する方向に延びる複数の波線を成すように設けられていてもよい。 Further, for example, the plurality of convex portions 134 may be provided so as to form a plurality of wavy lines extending in a direction orthogonal to the arrangement direction of the plurality of convex portions 134 when the first substrate 10 is viewed in plan.
　これにより、図３Ｂに示されるように、複数の凸部１３４が平面視において複数の波線を成すように設けられているので、例えば、波線毎にピーク位置、周期及び振幅などを異ならせた場合に、複数の凸部１３４の周期性を容易に乱すことができる。周期性が乱されることにより、回折現象が抑制され、虹むらを緩和することができる。 As a result, as shown in FIG. 3B, the plurality of convex portions 134 are provided so as to form a plurality of wavy lines in a plan view. For example, when the peak position, period, amplitude, etc. are different for each wavy line In addition, the periodicity of the plurality of convex portions 134 can be easily disturbed. When the periodicity is disturbed, the diffraction phenomenon is suppressed and rainbow irregularities can be mitigated.
　また、全反射面として機能する第２側面３４ｂは波線に沿って、ｘ軸に対して斜めに交差する面が含まれる。このため、配光制御デバイス１を透過する光の一部は、ｘ軸に沿った方向（例えば、左右方向）に広がるように配光される。このため、配光可能な範囲、具体的には、屋内の照射可能な範囲を拡げることができる。 Further, the second side surface 34b functioning as a total reflection surface includes a surface that intersects the x axis obliquely along the wavy line. For this reason, a part of the light transmitted through the light distribution control device 1 is distributed so as to spread in the direction along the x axis (for example, the left-right direction). For this reason, the range which can distribute light, specifically, the range which can be irradiated indoors can be expanded.
　また、例えば、遮光部３３の電気抵抗値は、絶縁性液体３６の電気抵抗値より小さく、第１電極層４０の電気抵抗値以上である。 For example, the electrical resistance value of the light shielding part 33 is smaller than the electrical resistance value of the insulating liquid 36 and is equal to or greater than the electrical resistance value of the first electrode layer 40.
　これにより、遮光部３３の抵抗が小さくなり、遮光部３３の電位を第１電極層４０の電位に近づけることができるので、ナノ粒子３７は、遮光部３３に引き寄せられやすくなる。したがって、絶縁性液体３６内でのナノ粒子３７の泳動がスムーズに行われ、配光状態及び透明状態の切り替えを速やかに行うことができる。 Thereby, the resistance of the light shielding part 33 is reduced and the potential of the light shielding part 33 can be brought close to the potential of the first electrode layer 40, so that the nanoparticles 37 are easily attracted to the light shielding part 33. Therefore, the migration of the nanoparticles 37 in the insulating liquid 36 is performed smoothly, and the light distribution state and the transparent state can be quickly switched.
　（その他）
　以上、本発明に係る配光制御デバイスについて、上記の実施の形態及びその変形例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。 (Other)
As described above, the light distribution control device according to the present invention has been described based on the above embodiment and the modifications thereof, but the present invention is not limited to the above embodiment.
　例えば、上記の実施の形態では、遮光部３３又は２３３が凹部３５の底に設けられている例を示したが、これに限らない。遮光部３３又は２３３は、第１電極層４０に接触していなくてもよく、第１電極層４０と遮光部３３又は２３３との間には、接着層などが設けられていてもよい。 For example, in the above-described embodiment, the example in which the light shielding portion 33 or 233 is provided at the bottom of the concave portion 35 is shown, but the present invention is not limited thereto. The light shielding part 33 or 233 may not be in contact with the first electrode layer 40, and an adhesive layer or the like may be provided between the first electrode layer 40 and the light shielding part 33 or 233.
　また、例えば、複数の凸部３４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３４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３４を、ドット状に点在するように配置してもよい。 Further, for example, the plurality of convex portions 34 may be divided into a plurality of portions in the x-axis direction. For example, the plurality of convex portions 34 may be arranged so as to be scattered in a matrix or the like. That is, you may arrange | position the some convex part 34 so that it may be scattered in dot shape.
　また、例えば、上記の実施の形態において、ナノ粒子３７の屈折率が絶縁性液体３６の屈折率より低くてもよい。ナノ粒子３７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。例えば、第１電極層４０及び第２電極層５０間に電圧が印加されていない場合に配光状態が実現され、電圧が印加された場合に透明状態が実現されてもよい。 Further, for example, in the above-described embodiment, the refractive index of the nanoparticles 37 may be lower than the refractive index of the insulating liquid 36. By appropriately adjusting the voltage to be applied according to the refractive index of the nanoparticles 37, a transparent state and a light distribution state can be realized. For example, the light distribution state may be realized when a voltage is not applied between the first electrode layer 40 and the second electrode layer 50, and the transparent state may be realized when a voltage is applied.
　また、例えば、上記の実施の形態において、ナノ粒子３７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３７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。 In addition, for example, in the above embodiment, the nanoparticles 37 are positively charged, but the present invention is not limited to this. That is, the nanoparticles 37 may be negatively charged. In this case, a direct voltage 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. Good.
　また、複数のナノ粒子３７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。 Further, the plurality of nanoparticles 37 may include a plurality of types of nanoparticles having different optical characteristics. For example, a transparent first nanoparticle charged positively and an opaque (black or the like) second nanoparticle charged negatively may be included. 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。 For example, in the above-described embodiment, an example in which an electrophoretic material is used as the refractive index variable material has been described. However, 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 refractive index variable layer changes using the birefringence of the liquid crystal molecules contained in the liquid crystal material. By changing the orientation of the liquid crystal molecules in accordance with the electric field applied to the refractive index variable layer, the refractive index of the refractive index variable layer changes. Thereby, the transparent state, the light distribution state, and the light distribution direction in the light distribution state can be controlled.
　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。 In the above embodiment, sunlight is exemplified as light incident on the light distribution control device. However, the present invention is not limited to this. For example, the light incident on the light distribution control device may be light emitted from 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。 Also, for example, the light distribution control device is not limited to being installed in a building window, and may be installed in a car window, for example. The light distribution control device can also be used for a light distribution control member such as a light-transmitting cover of a lighting fixture. Alternatively, the light distribution control device can also be used as a blindfold member that utilizes light scattering 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 embodiment can be realized by arbitrarily combining the components and functions in each embodiment without departing from the scope of the present invention, or a form obtained by subjecting each embodiment to various modifications conceived by those skilled in the art. Forms are also included in the present invention.
１、１０１、２０１　配光制御デバイス
１０　第１基板
２０　第２基板
３０、２３０　配光層
３１　凹凸構造層
３２　屈折率可変層
３３、２３３　遮光部
３４、１３４　凸部
３６　絶縁性液体
３７　ナノ粒子
４０　第１電極層
５０　第２電極層 DESCRIPTION OF SYMBOLS 1, 101, 201 Light distribution control device 10 1st board | substrate 20 2nd board | substrate 30, 230 Light distribution layer 31 Uneven structure layer 32 Refractive index variable layer 33, 233 Light-shielding part 34, 134 Projection part 36 Insulating liquid 37 Nanoparticle 40 First electrode layer 50 Second electrode layer

Claims (5)

  1. 　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、
    　並んで配置された複数の凸部を有する凹凸構造層と、
    　前記複数の凸部間である凹部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、
    　前記凹部に設けられた、入射した光の少なくとも一部を遮光する遮光部とを含み、
    　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、
    　前記遮光部は、導電性を有する
    　配光制御デバイス。     A first substrate having translucency;
    A second substrate having translucency, 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
    A concavo-convex structure layer having a plurality of convex portions arranged side by side;
    A refractive index variable layer that is disposed so as to fill a concave portion 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;
    A light shielding portion provided in the concave portion for shielding at least a part of incident light,
    The refractive index variable layer is
    An insulating liquid;
    A plurality of charged nanoparticles dispersed in the insulating liquid having a refractive index different from that of the insulating liquid;
    The light shielding unit is a light distribution control device having conductivity.
  2. 　前記遮光部は、前記凹部の底に設けられた遮光膜である
    　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 light shielding portion is a light shielding film provided on a bottom of the concave portion.
  3. 　前記複数の凸部の並び方向において、前記遮光膜の両端部の膜厚は、前記遮光膜の中央部の膜厚より大きい
    　請求項２に記載の配光制御デバイス。     The light distribution control device according to claim 2, wherein a film thickness at both end portions of the light shielding film is larger than a film thickness at a central portion of the light shielding film in an arrangement direction of the plurality of convex portions.
  4. 　前記複数の凸部は、前記第１基板を平面視した場合に、前記複数の凸部の並び方向に直交する方向に延びる複数の波線を成すように設けられている
    　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 plurality of convex portions are provided so as to form a plurality of wavy lines extending in a direction orthogonal to the arrangement direction of the plurality of convex portions when the first substrate is viewed in plan view. The light distribution control device according to claim 1.
  5. 　前記遮光部の電気抵抗値は、前記絶縁性液体の電気抵抗値より小さく、前記第１電極層の電気抵抗値以上である
    　請求項１～４のいずれか１項に記載の配光制御デバイス。     The light distribution control device according to any one of claims 1 to 4, wherein an electric resistance value of the light shielding portion is smaller than an electric resistance value of the insulating liquid and is equal to or larger than an electric resistance value of the first electrode layer.
PCT/JP2019/009687 2018-03-26 2019-03-11 Light distribution control device WO2019188191A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5642265A (en) * 1979-08-02 1981-04-20 Philips Nv Electrophoresis image display unit
JP2002122891A (en) * 2000-10-19 2002-04-26 Konica Corp Electrophoretic display device and method of manufacturing the same
JP2010510538A (en) * 2006-11-21 2010-04-02 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Switchable grid based on electrophoretic particle system
US7751667B2 (en) * 2005-12-21 2010-07-06 Xerox Corporation Microfabricated light collimating screen
JP2010538413A (en) * 2007-08-27 2010-12-09 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Optical output device
WO2015122083A1 (en) * 2014-02-17 2015-08-20 Ｎｌｔテクノロジー株式会社 Optical element, method for manufacturing same, display device having optical element, electronic device, and illumination device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5642265A (en) * 1979-08-02 1981-04-20 Philips Nv Electrophoresis image display unit
JP2002122891A (en) * 2000-10-19 2002-04-26 Konica Corp Electrophoretic display device and method of manufacturing the same
US7751667B2 (en) * 2005-12-21 2010-07-06 Xerox Corporation Microfabricated light collimating screen
JP2010510538A (en) * 2006-11-21 2010-04-02 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Switchable grid based on electrophoretic particle system
JP2010538413A (en) * 2007-08-27 2010-12-09 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Optical output device
WO2015122083A1 (en) * 2014-02-17 2015-08-20 Ｎｌｔテクノロジー株式会社 Optical element, method for manufacturing same, display device having optical element, electronic device, and illumination device

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