Light control device and method for manufacturing light control device

Abstract

This light control device comprises: a transparent substrate; a light control sheet in which a light control layer provided with a transparent resin layer defining a plurality of voids and a liquid crystal composition filled in the voids is sandwiched between a first electrode film and a second electrode film, the light control sheet being provided with a surface to be stuck facing the transparent substrate on the first electrode film; an adhesive layer with which the surface to be stuck is stuck on the transparent substrate; and a sealing part which fills a first gap between an edge part of the surface to be stuck and the transparent substrate and covers an end surface of the first electrode film and an end surface of the light control layer. The sealing part has a thickness by which an edge part of the adhesive layer is separated from the transparent substrate, and fills a second gap between the edge part of the adhesive layer and the transparent substrate.

Description

Light control device and method for manufacturing the same

[0001] The present disclosure relates to a light control device and a method for manufacturing a light control device.

[0002] An example of a light-controlling sheet includes a first transparent conductive film, a second transparent conductive film, and a light-controlling layer sandwiched between the first transparent conductive film and the second transparent conductive film. Each transparent conductive film includes a substrate and a transparent electrode supported by the substrate. A portion of the transparent electrode of the first transparent conductive film is exposed from the second transparent conductive film and the light-controlling layer. A portion of the transparent electrode of the second transparent conductive film is exposed from the first transparent conductive film and the light-controlling layer. The light-controlling sheet includes a sealing portion that covers the exposed portion of the transparent electrode of the first transparent conductive film, the edge face of the light-controlling layer, and the edge face of the second transparent conductive film. The light-controlling sheet includes a sealing portion that covers the exposed portion of the transparent electrode of the second transparent conductive film, the edge face of the light-controlling layer, and the edge face of the first transparent conductive film (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2020-21016

[0004] A portion of the sealing portion covering the edge of the first transparent conductive film is also located on a portion of the surface of the first transparent conductive film opposite the surface facing the light-controlling layer, which is continuous with the edge. For example, when the surface of the first transparent conductive film is attached to a support member by an adhesive layer, if the height of the sealing portion on the surface of the first transparent conductive film is greater than the thickness of the adhesive layer, the portion of the edge of the adhesive layer facing the sealing portion will peel off from the support member. The lower the height of the sealing portion on the surface of the first transparent conductive film, the smaller the amount of peeling of the adhesive layer can be. However, the lower the height of the sealing portion, the thinner the thickness of the sealing portion in the direction protruding from the edge of the first transparent conductive film in a plane parallel to the surface of the first transparent conductive film. This reduces the function of the sealing portion to seal the first transparent conductive film.

[0005] One aspect of the light control device is a light control sheet having a transparent substrate, a light control layer including a transparent resin layer defining a plurality of voids and a liquid crystal composition filled in the voids, sandwiched between a first electrode film and a second electrode film, the light control sheet including an attachment surface of the first electrode film facing the transparent substrate, an adhesive layer attaching the attachment surface to the transparent substrate, and a sealing portion that fills the gap between the edge of the attachment surface and the transparent substrate and covers the edge of the first electrode film and the edge of the light control layer. The sealing portion has a thickness that separates the edge of the adhesive layer from the transparent substrate and fills the gap between the edge of the adhesive layer and the transparent substrate.

[0006] One aspect of a method for manufacturing a light control device is a method for manufacturing a light control device comprising: a light control sheet in which a light control layer including a transparent substrate, a transparent resin layer defining a plurality of voids, and a liquid crystal composition filled in the voids is sandwiched between a first electrode film and a second electrode film, the light control sheet having an attachment surface facing the transparent substrate on the first electrode film, and an adhesive layer attaching the attachment surface to the transparent substrate. The light control sheet includes a first sealing element covering an edge surface of the first electrode film and an edge surface of the light control layer, the first sealing element having a height above the attachment surface greater than the thickness of the adhesive layer. The manufacturing method includes attaching the light-controlling sheet to the transparent substrate with the adhesive layer so that the first sealing element is in contact with the transparent substrate, thereby separating the edge of the adhesive layer from the transparent substrate; filling the gap between the edge of the adhesive layer and the transparent substrate and the gap between the adhesive layer and the first sealing element with ionizing radiation curable resin; and curing the ionizing radiation curable resin by irradiating it with ionizing radiation, thereby forming a sealing portion from the first sealing element and the ionizing radiation curable resin.

[0007] Fig. 1 is a plan view showing the structure of a light control device as seen from a viewpoint opposite to the plane on which the light control device extends. Fig. 2 is a cross-sectional view showing the structure of the light control device along line II-II shown in Fig. 1. Fig. 3 is a process diagram showing one step in a method for manufacturing a light control device. Fig. 4 is a process diagram showing one step in a method for manufacturing a light control device. Fig. 5 is a process diagram showing one step in a method for manufacturing a light control device. Fig. 6 is a process diagram showing one step in a method for manufacturing a light control device.

[0008] An embodiment of a light control device and a method for manufacturing the light control device will be described with reference to Figures 1 to 6. [Light Control Device] The light control device will be described with reference to Figures 1 and 2. Figure 1 shows the planar structure of the light control device as seen from a viewpoint opposite to the plane on which the light control device extends. Note that, for convenience of illustration, Figure 1 omits the illustration of a sealing portion provided in the light control device.

[0009] As shown in Fig. 1, the light control device 10 includes a transparent substrate 11 and a light control sheet 12. The light control sheet 12 is supported by the transparent substrate 11. The transparent substrate 11 and the light control sheet 12 have a flat plate shape. In the example shown in Fig. 1, the transparent substrate 11 and the light control sheet 12 have a rectangular shape. When viewed from a viewpoint opposite to the plane in which the transparent substrate 11 extends, the transparent substrate 11 is larger than the light control sheet 12, and the light control sheet 12 is located within the transparent substrate 11.

[0010] The type of the light controlling sheet 12 may be, for example, a normal type. The normal type light controlling sheet 12 has a high haze value when no voltage is applied to the light controlling sheet 12, and has a lower haze value when a voltage is applied to the light controlling sheet 12 than when no voltage is applied to the light controlling sheet 12.

[0011] The light controlling sheet 12 includes a first electrode portion 21C exposed to the outside and a second electrode portion 22C located between the light controlling sheet 12 and the transparent substrate 11. A first electrode terminal 24 is connected to the first electrode portion 21C. A second electrode terminal 25 is connected to the second electrode portion 22C. A first wiring 15A is connected to the first electrode terminal 24 by solder 24A. A second wiring 15B is connected to the second electrode terminal 25 by solder 25A. Each wiring 15A, 15B is connected to a drive unit 16 that applies a voltage to the light controlling sheet 12.

[0012] FIG. 2 shows the cross-sectional structure of the light control device 10 taken along line II-II in FIG. 1 . As shown in FIG. 2 , the light control device 10 further includes an adhesive layer 13 and a sealing portion 14. The adhesive layer 13 and the sealing portion 14 are transparent. The light control sheet 12 includes a first electrode film 21, a second electrode film 22, and a light control layer 23. The light control layer 23 includes a transparent resin layer that defines a plurality of voids, and a liquid crystal composition that fills the voids. The light control layer 23 is sandwiched between the first electrode film 21 and the second electrode film 22. The light control sheet 12 includes an attachment surface 21S on the first electrode film 21 that faces the transparent substrate 11.

[0013] The first electrode film 21 includes a first substrate 21A and a first electrode layer 21B. Both the first substrate 21A and the first electrode layer 21B are transparent. The first substrate 21A supports the first electrode layer 21B. The second electrode film 22 includes a second substrate 22A and a second electrode layer 22B. Both the second substrate 22A and the second electrode layer 22B are transparent. The second substrate 22A supports the second electrode layer 22B. In the thickness direction of the light controlling sheet 12, the first electrode layer 21B and the second electrode layer 22B face each other with the light controlling layer 23 sandwiched therebetween.

[0014] The adhesive layer 13 attaches the attachment surface 21S to the transparent substrate 11. The adhesive layer 13 is located between the transparent substrate 11 and the attachment surface 21S and is in contact with the transparent substrate 11 and the attachment surface 21S, thereby attaching the attachment surface 21S to the transparent substrate 11.

[0015] The sealing portion 14 fills a first gap G1, which is a gap between the edge portion 21SE of the attachment surface 21S and the transparent substrate 11, and covers the end surface 21E of the first electrode film 21 and the end surface 23E of the light-controlling layer 23. When viewed from a viewpoint facing the attachment surface 21S, the edge portion 21SE of the attachment surface 21S has a closed ring shape that follows the outer edge of the first electrode film 21. When viewed from a viewpoint facing the attachment surface 21S, the edge portion 21SE of the attachment surface 21S has a width that extends from the outer edge of the first electrode film 21 into the attachment surface 21S. The first gap G1 is a space that extends between the edge portion 21SE of the attachment surface 21S and a surface of the transparent substrate 11 that faces the attachment surface 21S.

[0016] The end surface 21E of the first electrode film 21 is a surface that connects the adhered surface 21S and the surface opposite the adhered surface 21S in the thickness direction of the first electrode film 21. The end surface 21E has a closed ring shape that follows the outer edge of the first electrode film 21. The end surface 21E includes the end surface of the first base material 21A and the end surface of the first electrode layer 21B. The end surface of the first base material 21A is a surface that connects a pair of surfaces of the first base material 21A in the thickness direction of the light controlling sheet 12. The end surface of the first electrode layer 21B is a surface that connects a pair of surfaces of the first electrode layer 21B in the thickness direction of the light controlling sheet 12. The end surface 23E of the light controlling layer 23 is a surface that connects a pair of surfaces of the light controlling layer 23 in the thickness direction of the light controlling layer 23. The end surface 23E has a closed ring shape that follows the outer edge of the light controlling layer 23.

[0017] The sealing portion 14 has a thickness that separates the edge 13E of the adhesive layer 13 from the transparent substrate 11 and fills the second gap G2, which is the gap between the edge 13E of the adhesive layer 13 and the transparent substrate 11. The thickness of the sealing portion 14 is the distance between the surface of the transparent substrate 11 that the adhesive layer 13 contacts and the second electrode layer 22B, and may be the distance at the portion of the sealing portion 14 where the thickness of the sealing portion 14 is greatest between the transparent substrate 11 and the attachment surface 21S. The edge 13E of the adhesive layer 13 includes the outer edge of the adhesive layer 13 and has a closed ring shape that follows the outer edge when viewed from a perspective opposite to the plane in which the adhesive layer 13 extends. When viewed from a perspective opposite to the plane in which the adhesive layer 13 extends, the edge 13E of the adhesive layer 13 has a width that extends from the outer edge of the adhesive layer 13 into the adhesive layer 13 and a thickness equal to the adhesive layer 13. The second gap G2 is a space extending between the surface of the transparent substrate 11 facing the adhesive layer 13 and the surface of the adhesive layer 13 facing the transparent substrate 11 .

[0018] According to the light control device 10 of the present disclosure, the thickness of the sealing portion 14 is thick enough to separate the edge portion 13E of the adhesive layer 13 from the transparent substrate 11, so that the sealing portion 14 can ensure the function of sealing the edge surface 21E of the first electrode film 21 and the edge surface 23E of the light control layer 23. Furthermore, because the sealing portion 14 fills the second gap G2 between the edge portion 13E of the adhesive layer 13 and the transparent substrate 11, the second gap G2 is prevented from being visible through the transparent substrate 11. Thus, according to the light control device 10, when attaching the light control sheet 12 to the transparent substrate 11, it is possible to achieve both the sealing function of the sealing portion 14 and the aesthetic appearance of the light control sheet 12.

[0019] From the viewpoint of preventing the adhesive layer 13 from lifting due to the sealing portion 14, it is preferable that the thickness of the sealing portion 14 is thin. However, the thinner the thickness of the sealing portion 14, the less effective the sealing portion 14 is in sealing the light-controlling layer 23. This results in, for example, a decrease in the moist heat resistance of the light-controlling sheet 12. In this regard, according to the present disclosure, the thickness of the sealing portion 14 is thick enough to separate the edge portion 13E of the adhesive layer 13 from the transparent substrate 11, and therefore the sealing function of the sealing portion 14 can be sufficiently ensured.

[0020] From the viewpoint of reducing the thickness of the light control device 10, it is preferable that the thickness of the adhesive layer 13 is thin. Furthermore, since the adhesive layer 13 is a layer that has predetermined optical properties, weather resistance, and adhesive reliability at a predetermined thickness, it is not easy to change the thickness of the adhesive layer 13 according to the thickness of the sealing portion 14 so that the edge portion 13E of the adhesive layer 13 does not separate from the transparent substrate 11.

[0021] The second electrode film 22 includes a second electrode portion 22C exposed from the light-controlling layer 23 and the first electrode film 21. The sealing portion 14 may further fill a third gap G3 between the second electrode portion 22C and the transparent substrate 11. The second electrode portion 22C is a region of the second electrode film 22 that is not covered by the light-controlling layer 23 and the first electrode film 21. The second electrode portion 22C is conductive. The third gap G3 is a space extending between a surface of the second electrode portion 22C facing the transparent substrate 11 and a surface of the transparent substrate 11 facing the second electrode portion 22C. The sealing portion 14 seals the second electrode portion 22C in addition to the end surface 21E of the first electrode film 21 and the end surface 23E of the light-controlling layer 23. This enhances the sealing function of the sealing portion 14.

[0022] 2, the light-controlling sheet 12 further includes a second electrode terminal 25 connected to the second electrode portion 22C of the second electrode film 22. The sealing portion 14 may cover the second electrode terminal 25 and the portion of the second electrode portion 22C that is exposed from the second electrode terminal 25. The sealing portion 14 seals not only the end surface 21E of the first electrode film 21 and the end surface 23E of the light-controlling layer 23, but also the second electrode terminal 25, thereby improving the sealing function of the sealing portion 14.

[0023] The first electrode film 21 includes a first electrode portion 21C exposed from the second electrode film 22 and the light control layer 23. The first electrode portion 21C is a region of the first electrode film 21 that is not covered by the light control layer 23 or the second electrode film 22. The first electrode portion 21C is conductive. The light control sheet 12 may further include a first electrode terminal 24 connected to the first electrode portion 21C of the first electrode film 21.

[0024] The light-adjusting sheet 12 may include a sealing portion 26. The sealing portion 26 covers the first electrode terminal 24, a portion of the first electrode portion 21C exposed from the first electrode terminal 24, an end surface 22E of the second electrode film 22, and a portion of the end surface 23E of the light-adjusting layer 23 that is different from the portion covered by the sealing portion 14.

[0025] The end surface 22E of the second electrode film 22 is a surface that connects a pair of surfaces provided on the second electrode film 22 in the thickness direction of the second electrode film 22. The end surface 22E has a closed ring shape that follows the outer edge of the second electrode film 22. The end surface 22E includes an end surface of the second base material 22A and an end surface of the second electrode layer 22B. The end surface of the second base material 22A is a surface that connects a pair of surfaces provided on the second base material 22A in the thickness direction of the second base material 22A. The end surface of the second electrode layer 22B is a surface that connects a pair of surfaces provided on the second electrode layer 22B in the thickness direction of the second electrode layer 22B.

[0026] [Method of Manufacturing Light Control Device] A method of manufacturing the light control device will be described with reference to Figures 3 to 6. The method of manufacturing the light control device 10 includes separating the edge portion 13E of the adhesive layer 13 from the transparent substrate 11, filling with an ionizing radiation curable resin, and forming a sealing portion 14 from a first sealing element and the ionizing radiation curable resin. In separating the edge portion 13E of the adhesive layer 13 from the transparent substrate 11, the light control sheet 12 is attached to the transparent substrate 11 by the adhesive layer 13 so that the first sealing element of the light control sheet 12 contacts the transparent substrate 11. In filling with the ionizing radiation curable resin, the ionizing radiation curable resin is filled in the gap between the edge portion 13E of the adhesive layer 13 and the transparent substrate 11 and the gap between the adhesive layer 13 and the first sealing element. In forming the sealing portion 14, the ionizing radiation curable resin is cured by irradiating the ionizing radiation curable resin with ionizing radiation.

[0027] According to the manufacturing method of the light control device 10, the thickness of the first sealing element is thick enough to separate the edge portion 13E of the adhesive layer 13 from the transparent substrate 11, thereby ensuring the first sealing element's ability to seal the edge surface 21E of the first electrode film 21 and the edge surface 23E of the light control layer 23. Furthermore, the ionizing radiation curable resin filled in the gap between the edge portion 13E of the adhesive layer 13 and the transparent substrate 11 and the gap between the adhesive layer 13 and the first sealing element forms a sealing portion 14 together with the first sealing element, thereby reducing visibility of the gap between the transparent substrate 11 and the light control sheet 12 through the transparent substrate 11. Thus, according to the manufacturing method of the light control device 10, it is possible to achieve both the sealing function of the sealing portion 14 and the aesthetic appearance of the light control sheet 12 when attaching the light control sheet 12 to the transparent substrate 11. The manufacturing method of the light control device 10 will be described in more detail below with reference to the drawings.

[0028] 3 shows the cross-sectional structure of the light controlling sheet 12 before it is attached to the transparent substrate 11. FIG. 3 shows the cross-sectional structure of the light controlling sheet 12, which corresponds to the cross-sectional structure along line II-II shown in FIG. 1, together with the cross-sectional structure of the adhesive layer 13.

[0029] 3, the light controlling sheet 12 before application includes a first electrode film 21, a second electrode film 22, and a light controlling layer 23, similar to the light controlling sheet 12 after application described above. The first electrode film 21 includes a first electrode portion 21C exposed from the second electrode film 22 and the light controlling layer 23. A first electrode terminal 24 is connected to the first electrode portion 21C. The second electrode film 22 includes a second electrode portion 22C exposed from the first electrode film 21 and the light controlling layer 23. A second electrode terminal 25 is connected to the second electrode portion 22C. The light controlling sheet 12 includes a sealing portion 26 that covers the first electrode portion 21C, an end surface 22E of the second electrode film 22, and an end surface 23E of the light controlling layer 23.

[0030] The light-controlling sheet 12 includes a first sealing element 14A. The first sealing element 14A covers the edge 21SE of the attachment surface 21S, the edge 21E of the first electrode film 21, the edge 23E of the light-controlling layer 23, and the second electrode portion 22C. The first sealing element 14A covers the corner of the light-controlling sheet 12 formed by the attachment surface 21S and the edge 22E of the second electrode film 22. Therefore, the thickness of the first sealing element 14A, which extends outward from the outer edge of the first electrode film 21 along a plane parallel to the attachment surface 21S, tends to be thin. The thickness of the first sealing element 14A tends to be thicker as the amount of protrusion of the first sealing element 14A away from the attachment surface 21S increases, and thinner as the amount of protrusion decreases. The smaller the amount that first sealing element 14A protrudes, the less effective first sealing element 14A is in sealing end surface 21E of first electrode film 21 and end surface 23E of light-control layer 23 .

[0031] Therefore, the amount by which the first sealing element 14A protrudes in the direction away from the attachment surface 21S, i.e., the height H14A of the first sealing element 14A above the attachment surface 21S, is set to be greater than the thickness T13 of the adhesive layer 13.

[0032] Before the light controlling sheet 12 is attached to the transparent substrate 11 , the adhesive layer 13 is attached to the attachment surface 21S of the first electrode film 21 .

[0033] 4 shows a state in which adhesive layer 13, which has been attached to receiving surface 21S, is attached to transparent substrate 11. As shown in FIG. 4, adhesive layer 13 is attached to transparent substrate 11. As described above, because height H14A of first sealing element 14A on receiving surface 21S is thicker than the thickness of adhesive layer 13, adhesive layer 13 contacts transparent substrate 11, and the top of first sealing element 14A contacts transparent substrate 11. As a result, edge portion 13E of adhesive layer 13, which is the portion facing first sealing element 14A, floats above transparent substrate 11 in accordance with the difference between height H14A of first sealing element 14A and thickness T13 of adhesive layer 13. As a result, a second gap G2 is formed between edge portion 13E of adhesive layer 13 and transparent substrate 11. The size of the second gap G2 tends to increase as the difference between the height H14A of the first sealing element 14A and the thickness T13 of the adhesive layer 13 increases, and tends to decrease as the difference between the height H14A of the first sealing element 14A and the thickness T13 of the adhesive layer 13 decreases.

[0034] As described above, because height H14A of first sealing element 14A on attachment surface 21S is greater than the thickness of adhesive layer 13, edge 13E of adhesive layer 13 floats above transparent substrate 11 in the vicinity of first sealing element 14A. On the other hand, the farther away from first sealing element 14A is, the smaller the effect of height H14A of first sealing element 14A on adhesive layer 13, and therefore the portion of adhesive layer 13 away from edge 13E is in close contact with transparent substrate 11. Therefore, second electrode film 22 is not flat in a cross section taken along line II-II and perpendicular to the plane in which transparent substrate 11 extends.

[0035] As shown in Fig. 5, ionizing radiation curable resin RR is filled between transparent substrate 11 and second electrode film 22. The ionizing radiation curable resin RR is transparent. At this time, the ionizing radiation curable resin RR is filled between first sealing element 14A and transparent substrate 11 on the side opposite adhesive layer 13 with respect to first sealing element 14A. The ionizing radiation curable resin RR is filled between transparent substrate 11 and second electrode film 22 from the side opposite adhesive layer 13 with respect to first sealing element 14A so as to fill third gap G3 and second gap G2. As a result, the space between transparent substrate 11 and second electrode film 22 where first sealing element 14A is not located is filled with ionizing radiation curable resin RR.

[0036] As a result, in the sealing portion 14 formed by curing the ionizing radiation curable resin RR, the thickness of the sealing portion 14 in the direction protruding from the end surface 21E of the first electrode film 21 becomes even thicker in the plane in which the first electrode film 21 extends, thereby further improving the function of the sealing portion 14 to seal the light controlling sheet 12.

[0037] The ionizing radiation that cures the ionizing radiation curable resin RR may be ultraviolet light or electron beams. The ionizing radiation curable resin RR may be an ultraviolet light curable resin or an electron beam curable resin.

[0038] 6, ionizing radiation R is irradiated to the ionizing radiation curable resin RR filled between the transparent substrate 11 and the second electrode film 22. This forms a second sealing element 14B, which is a cured product of the ionizing radiation curable resin RR. As a result, a sealing portion 14 composed of the first sealing element 14A and the second sealing element 14B is formed.

[0039] The first sealing element 14A is formed from a transparent synthetic resin. The refractive index of the first sealing element 14A is preferably equal to the refractive index of the second sealing element 14B. This prevents the boundary between the first sealing element 14A and the second sealing element 14B from being visible. The first sealing element 14A may be formed from an ionizing radiation curable resin RR. The ionizing radiation curable resin RR forming the first sealing element 14A is preferably the same as the ionizing radiation curable resin forming the second sealing element 14B. This prevents the boundary between the first sealing element 14A and the second sealing element 14B from being visible and improves adhesion of the second sealing element 14B to the first sealing element 14A.

[0040] 2 to 6, first sealing element 14A is illustrated separately from second sealing element 14B. However, if first sealing element 14A and second sealing element 14B have the same refractive index and if the two sealing elements 14A and 14B are made of the same material, first sealing element 14A and second sealing element 14B are recognized as an integrated cured body.

[0041] [Materials] In the light controlling sheet 12, the base materials 21A, 22A provided in each electrode film 21, 22 may be formed from a synthetic resin or an inorganic compound. The synthetic resin may be, for example, a polyester-based resin, a polyacrylate-based resin, a polycarbonate-based resin, a polyolefin-based resin, etc. The polyester-based resin may be, for example, polyethylene terephthalate, polyethylene naphthalate, etc. The polyacrylate-based resin may be, for example, polymethyl methacrylate, etc. The inorganic compound may be, for example, silicon dioxide, silicon oxynitride, silicon nitride, etc.

[0042] The electrode layers 21B, 22B of each electrode film 21, 22 may be formed from any one selected from the group consisting of, for example, indium tin oxide, fluorine-doped tin oxide, tin oxide, zinc oxide, carbon nanotubes, silver-based alloys, and poly(3,4-ethylenedioxythiophene).

[0043] The liquid crystal composition includes a liquid crystal compound. The liquid crystal composition may include a dichroic dye, and may also include additives such as an antifoaming agent, an antioxidant, a weatherproofing agent, a solvent, and a viscosity reducing agent. The weatherproofing agent may be an ultraviolet absorber or a light stabilizer.

[0044] The normal-type light-controlling sheet may contain, for example, a liquid crystal compound having positive dielectric anisotropy. The liquid crystal compound may be at least one selected from the group consisting of Schiff bases, azo compounds, azoxy compounds, biphenyl compounds, terphenyl compounds, benzoates, tolanes, pyrimidine compounds, pyridazine compounds, cyclohexanecarboxylic acid ester compounds, phenylcyclohexane compounds, biphenylcyclohexane compounds, dicyanobenzene compounds, naphthalene compounds, and dioxane compounds. The liquid crystal compound may be one type of liquid crystal compound or a combination of two or more types of liquid crystal compounds.

[0045] The transparent resin layer is a cured product of a photopolymerizable composition. The light for polymerizing the photopolymerizable composition may be ultraviolet light or an electron beam. The photopolymerizable composition may be an ultraviolet-polymerizable composition or an electron-beam-polymerizable composition. The lower and upper limits of the content of the transparent resin layer in the light-controlling layer 23 are within a range in which liquid crystal particles composed of a liquid crystal compound phase-separate from the polymer of the photopolymerizable composition during the polymerization process of the photopolymerizable composition.

[0046] The transparent substrate 11 may be formed from a synthetic resin or glass. The synthetic resin may be, for example, an acrylic resin or a polycarbonate resin. The adhesive layer 13 may be, for example, self-adhesive. The self-adhesive property of the adhesive layer 13 enables the light-controlling sheet 12 to be peeled off from the transparent substrate 11 due to external stress and to be re-adhered to the transparent substrate 11. The self-adhesive adhesion of the adhesive layer 13 does not require processing such as heating or drying when the adhesive layer 13 is in contact with the light-controlling sheet 12 and the transparent substrate 11. Furthermore, the light-controlling sheet 12 is adhered to the transparent substrate 11 by its own weight without pressing the light-controlling sheet 12 against the transparent substrate 11.

[0047] Each of the sealing elements 14A, 14B and the sealing portion 26 may be formed from at least one resin selected from the group consisting of, for example, polyacrylate-based resin, epoxy-based resin, allyl-based resin, polyurethane-based resin, and silicone-based resin.

[0048] As described above, one embodiment of the light control device and the method for manufacturing the light control device can achieve the following effects: (1) Because the thickness of the sealing portion 14 is thick enough to separate the edge portion 13E of the adhesive layer 13 from the transparent substrate 11, it is possible to ensure that the sealing portion 14 has the function of sealing the edge surface 21E of the first electrode film 21 and the edge surface 23E of the light control layer 23. Furthermore, because the sealing portion 14 fills the gap between the edge portion 13E of the adhesive layer 13 and the transparent substrate 11, it is possible to prevent the gap between the edge portion 13E of the adhesive layer 13 and the transparent substrate 11 from being visible through the transparent substrate 11.

[0049] (2) The sealing portion 14 seals the second electrode portion 22C in addition to the end surface 21E of the first electrode film 21 and the end surface 23E of the light-controlling layer 23, thereby enhancing the sealing function of the sealing portion 14. (3) The sealing portion seals the second electrode terminal 25 in addition to the end surface 21E of the first electrode film 21 and the end surface 23E of the light-controlling layer 23, thereby enhancing the sealing function of the sealing portion 14.

[0050] (4) Because the thickness of the first sealing element 14A is thick enough to separate the edge portion 13E of the adhesive layer 13 from the transparent substrate 11, it is possible to ensure that the first sealing element 14A functions to seal the edge surface 21E of the first electrode film 21 and the edge surface 23E of the light-controlling layer 23. Furthermore, the ionizing radiation curable resin RR filled in the gap between the edge portion 13E of the adhesive layer 13 and the transparent substrate 11 and the gap between the adhesive layer 13 and the first sealing element 14A forms the sealing portion 14 together with the first sealing element 14A. This prevents the gap between the transparent substrate 11 and the light-controlling sheet 12 from being visible through the transparent substrate 11.

[0051] (5) In the sealing portion 14 formed by curing the ionizing radiation curable resin RR, the thickness of the sealing portion 14 in the direction protruding from the end surface 21E of the first electrode film 21 is further increased in the plane in which the first electrode film 21 extends. This further enhances the sealing function of the sealing portion 14.

[0052] The above-described embodiment can be modified as follows: [Light-adjusting sheet] The type of the light-adjusting sheet 12 is not limited to a normal type, but may be a reverse type. A reverse-type light-adjusting sheet has a low haze value when no voltage is applied to the light-adjusting sheet, and has a higher haze value when a voltage is applied to the light-adjusting sheet compared to when no voltage is applied to the light-adjusting sheet.

[0053] The reverse-type light-controlling sheet further includes, for example, a pair of vertical alignment films sandwiching the light-controlling layer 23 in the thickness direction of the light-controlling layer 23. Each vertical alignment film is located between the electrode layers 21B, 22B of each electrode film 21, 22 and the light-controlling layer 23. The light-controlling layer 23 may include, for example, a liquid crystal compound having negative dielectric anisotropy.

[0054] The light controlling sheet 12 may have a curved surface. The outer shape of the light controlling sheet 12 may be a shape other than a rectangle. For example, the outer shape of the light controlling sheet 12 may be a circle, an ellipse, or a polygon other than a rectangle.

[0055] [Sealing Portion] As described above, the material for forming first sealing element 14A may be different from the material for forming second sealing element 14B. In this case, first sealing element 14A can be distinguished from second sealing element 14B, and therefore first sealing element 14A and second sealing element 14B can be identified as follows:

[0056] The first sealing element 14A covers an end surface 21E of the first electrode film 21 and an end surface 23E of the light-controlling layer 23. In the first sealing element 14A, the height from the attachment surface 21S to the transparent substrate 11 is greater than the thickness of the adhesive layer 13. The second sealing element 14B fills the gap between the edge portion 13E of the adhesive layer 13 and the transparent substrate 11, and the gap between the adhesive layer 13 and the first sealing element 14A.

[0057] [Functional Layer] The light controlling sheet 12 may include various functional layers. The functional layer may be included in at least one of the first electrode film 21 and the second electrode film 22. That is, only the first electrode film 21 may include a functional layer, only the second electrode film may include a functional layer, or both the first electrode film 21 and the second electrode film 22 may include a functional layer.

[0058] When the first electrode film 21 includes a functional layer, the functional layer may be located between the first substrate 21A and the first electrode layer 21B, or may be located on the opposite side of the first substrate 21A from the first electrode layer 21B. When the second electrode film 22 includes a functional layer, the functional layer may be located between the second substrate 22A and the second electrode layer 22B, or may be located on the opposite side of the second substrate 22A from the second electrode layer 22B.

[0059] The functional layer may be any one selected from the group consisting of a hard coat layer, an anti-blocking layer, a primer layer, a protective layer, and an index matching layer. The light controlling sheet 12 may include two or more functional layers.

[0060] [Notes] The above embodiments and modifications lead to the following technical ideas: [Note 1] A light control device comprising: a transparent substrate; a light control sheet in which a light control layer including a transparent resin layer defining a plurality of voids and a liquid crystal composition filled in the voids is sandwiched between a first electrode film and a second electrode film, the light control sheet having an attachment surface on the first electrode film facing the transparent substrate; and an adhesive layer attaching the attachment surface to the transparent substrate, the light control device comprising: a first sealing element covering an end surface of the first electrode film and an end surface of the light control layer, the first sealing element having a height from the attachment surface to the transparent substrate greater than a thickness of the adhesive layer; and a second sealing element filling a gap between an edge of the adhesive layer and the transparent substrate and a gap between the adhesive layer and the first sealing element, the material constituting the first sealing element being different from the material constituting the second sealing element.

[0061] [Supplementary Note 2] The light control device according to Supplementary Note 1, wherein the second sealing element further fills a gap between the first sealing element and the transparent substrate.

Claims

1. A light control device comprising: a transparent substrate; a light control layer sandwiched between a first electrode film and a second electrode film, the light control layer comprising a transparent resin layer defining a plurality of voids and a liquid crystal composition filled in the voids, the first electrode film having an attachment surface facing the transparent substrate; an adhesive layer attaching the attachment surface to the transparent substrate; and a sealing portion filling the gap between an edge of the attachment surface and the transparent substrate and covering an edge of the first electrode film and an edge of the light control layer, the sealing portion having a thickness that separates an edge of the adhesive layer from the transparent substrate and filling the gap between the edge of the adhesive layer and the transparent substrate.

2. The light control device according to claim 1, wherein the second electrode film includes an electrode portion exposed from the light control layer and the first electrode film, and the sealing portion further fills a gap between the electrode portion and the transparent substrate.

3. The light control device according to claim 2, wherein the light control sheet further comprises an electrode terminal connected to the electrode portion of the second electrode film, and the sealing portion covers the electrode terminal and a portion of the electrode portion exposed from the electrode terminal.

4. A method for manufacturing a light control device comprising: a transparent substrate; a light control layer comprising a transparent resin layer defining a plurality of voids and a liquid crystal composition filled in the voids, the light control sheet being sandwiched between a first electrode film and a second electrode film, the first electrode film having an attachment surface facing the transparent substrate; and an adhesive layer attaching the attachment surface to the transparent substrate, the light control sheet including a first sealing element covering an end surface of the first electrode film and an end surface of the light control layer, the first sealing element having a height on the attachment surface greater than a thickness of the adhesive layer, the light control sheet being attached to the transparent substrate by the adhesive layer so that the first sealing element is in contact with the transparent substrate, thereby separating an edge of the adhesive layer from the transparent substrate; filling a gap between the edge of the adhesive layer and the transparent substrate and a gap between the adhesive layer and the first sealing element with an ionizing radiation curable resin; the ionizing radiation curable resin is cured by irradiating the ionizing radiation curable resin with ionizing radiation, thereby forming a sealing portion from the first sealing element and the ionizing radiation curable resin.

5. The method for manufacturing a light control device according to claim 4, wherein filling the ionizing radiation curable resin further comprises filling the gap between the first sealing element and the transparent substrate on the side of the first sealing element opposite the adhesive layer.

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