Light control sheet and method for manufacturing light control sheet

Abstract

To provide a light control sheet that can suppress peeling starting from a corner portion of the light control sheet, and a method for manufacturing the light control sheet.SOLUTION: A light control sheet 20 comprises a first transparent conductive sheet, a second transparent conductive sheet, and a light control layer located between the first transparent conductive sheet and the second transparent conductive sheet. In the light control sheet 20, a state of light transmitted through the light control layer changes depending on the application of voltage between the first transparent conductive sheet and the second transparent conductive sheet. When viewed from a viewpoint facing a plane on which the light control sheet 20 extends, the light control sheet 20 includes an outer edge 20E. The outer edge 20E has one or more corner portions 20C. At the corner portion 20C, an arc-shaped outer shape whose center of curvature is located inside the light control sheet 20 is continuous in a thickness direction of the light control sheet 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a light-controlling sheet and a method for manufacturing the light-controlling sheet. [Background technology]

[0002] The light-controlling sheet includes a pair of transparent conductive sheets and a light-controlling layer located between the pair of transparent conductive sheets. Each transparent conductive sheet includes a transparent substrate having insulating properties and a transparent electrode layer having conductivity. The light-controlling layer is located between the pair of transparent electrode layers.

[0003] An example of a light-controlling layer includes a liquid crystal composition and a transparent polymer layer. The liquid crystal composition includes a plurality of liquid crystal compounds. The plurality of liquid crystal compounds have different alignments between a state where no potential difference is applied between a pair of transparent electrode layers and a state where a potential difference is applied between the pair of transparent electrode layers. The light-controlling sheet has a diffuse transmittance that corresponds to the alignment of the liquid crystal compounds depending on the potential difference between the pair of transparent electrode layers (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-070962 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when viewed from a viewpoint opposite the plane on which the light-adjusting sheet spreads, the light-adjusting sheet may have a corner formed by a first straight line and a second straight line. For example, if the light-adjusting sheet has a rectangular shape when viewed from a viewpoint opposite the plane on which the light-adjusting sheet spreads, the light-adjusting sheet has four corners. Stress tends to concentrate at the corners of the light-adjusting sheet, and the area contributing to adhesion between the layers of the light-adjusting sheet is small at the corners. As a result, peeling is likely to occur starting from the corners of the light-adjusting sheet. [Means for solving the problem]

[0006] A light-controlling sheet that solves the above problems includes a first transparent conductive sheet, a second transparent conductive sheet, and a light-controlling layer located between the first transparent conductive sheet and the second transparent conductive sheet, and the state of light transmitted through the light-controlling layer changes depending on the application of a voltage between the first transparent conductive sheet and the second transparent conductive sheet. When viewed from a viewpoint opposite to the plane in which the light-controlling sheet extends, the light-controlling sheet has an outer edge. The outer edge includes one or more corners. At the corners, an arc-shaped outline whose center of curvature is located within the light-controlling sheet continues in the thickness direction of the light-controlling sheet.

[0007] A method for manufacturing a light-controlling sheet that solves the above-mentioned problems includes a first transparent conductive sheet, a second transparent conductive sheet, and a light-controlling layer located between the first transparent conductive sheet and the second transparent conductive sheet, and the state of light transmitted through the light-controlling layer changes in response to application of a voltage between the first transparent conductive sheet and the second transparent conductive sheet. The method for manufacturing a light-controlling sheet includes forming a pre-cut sheet of the light-controlling sheet by forming the light-controlling layer between the first transparent conductive sheet and the second transparent conductive sheet, and cutting the pre-cut sheet with a cutting blade extending from the first transparent conductive sheet to the second transparent conductive sheet so that the pre-cut sheet has a predetermined outer edge when viewed from a viewpoint opposite to the plane in which the pre-cut sheet extends, thereby forming the light-controlling sheet with the outer edge. Forming the light-controlling sheet with the outer edge includes forming the light-controlling sheet with one or more corners, the corners having an arc-shaped outline with a center of curvature located within the light-controlling sheet and continuing in the thickness direction of the light-controlling sheet.

[0008] According to the light-adjusting sheet and the method for manufacturing the light-adjusting sheet, the arc-shaped contours at the corners of the light-adjusting sheet are connected in the thickness direction of the light-adjusting sheet, so stress is less likely to concentrate at the corners than in a contour where two straight lines intersecting at a single point are connected in the thickness direction of the light-adjusting sheet, which reduces the risk of peeling starting from the corners.

[0009] In the light controlling sheet, the radius of curvature of the outer shape may be 1 mm or more and 10 mm or less. With the light-controlling sheet, the corners of the sheet are prevented from deforming from the designed shape during or after processing by having a curvature radius of 1 mm or more, thereby preventing a decrease in the accuracy of the corner shape. Also, the curvature radius is 10 mm or less, preventing the corners from becoming too smooth.

[0010] The light-controlling sheet includes a first transparent conductive sheet, a second transparent conductive sheet, and a light-controlling layer located between the first transparent conductive sheet and the second transparent conductive sheet, and the state of light transmitted through the light-controlling layer changes depending on the application of a voltage between the first transparent conductive sheet and the second transparent conductive sheet. When viewed from a viewpoint facing the plane in which the light-controlling sheet extends, the laminate of the first transparent conductive sheet and the light-controlling layer has a first outer edge, and the second transparent conductive sheet has a second outer edge, the first outer edge being smaller than the second outer edge and located within the second outer edge. The first outer edge includes a first corner, which is located within the second outer edge and includes a second corner. At the first corner, a first arc-shaped outer shape with a radius of curvature located within the light-controlling sheet continues in the thickness direction of the laminate. At the second corner, an arc-shaped second contour having a radius of curvature positioned within the light-control sheet continues in the thickness direction of the second transparent conductive sheet.

[0011] According to the light-adjusting sheet, the arc-shaped contours are connected in the thickness direction of the light-adjusting sheet at both the first corner and the second corner. Therefore, stress is less likely to concentrate at both the first corner and the second corner compared to a contour in which two straight lines intersecting at one point are connected in the thickness direction of the light-adjusting sheet. Therefore, peeling starting from the corners is suppressed.

[0012] In the light controlling sheet, the first corner portion and the second corner portion may be arranged in one direction with an interval therebetween, and the radius of curvature of the first outer shape may be smaller than the radius of curvature of the second outer shape.

[0013] With the above-mentioned dimming sheet, the area in which the state of light incident on the dimming layer can be changed by applying a voltage between the transparent electrode layers is prevented from becoming smaller, compared to when the radius of curvature of the first outer shape is greater than or equal to the radius of curvature of the second outer shape.

[0014] In the light controlling sheet, the second outer shape may have a radius of curvature of 1 mm or more and 10 mm or less, and the first outer shape may have a radius of curvature of 0.5 mm or more and 5 mm or less. According to the light-controlling sheet, the radius of curvature of the second outer shape is 1 mm or more, and the radius of curvature of the first outer shape is 0.5 mm or more, thereby preventing a decrease in the accuracy of the shape of each corner. Furthermore, the radius of curvature of the second outer shape is 10 mm or less, and the radius of curvature of the first outer shape is 5 mm or less, thereby preventing each corner from becoming too smooth. [Effects of the Invention]

[0015] According to the light controlling sheet of the present disclosure, it is possible to prevent peeling starting from the corners of the light controlling sheet. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a plan view showing the structure of a light controlling sheet in the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the structure of the light-control sheet. [Figure 3] FIG. 3 is a cross-sectional view showing another example of the structure of the light controlling sheet. [Figure 4] FIG. 4 is a plan view showing the structure of a light controlling sheet in the second embodiment. [Figure 5] FIG. 5 is an enlarged plan view showing a part of the light controlling sheet. [Figure 6] FIG. 6 is a cross-sectional view showing the structure of the light controlling sheet. [Figure 7] FIG. 7 is a cross-sectional view showing another example of the structure of the light controlling sheet. DETAILED DESCRIPTION OF THE INVENTION

[0017] [First embodiment] [Light-adjusting sheet] A first embodiment of a light controlling sheet and a method for manufacturing the light controlling sheet will be described with reference to FIGS. 1 to 3. FIG.

[0018] The light controlling sheet 20 shown in Figure 1 is attached to a flat transparent member 10. When viewed from a viewpoint opposite to the plane on which the light controlling sheet 20 extends, the light controlling sheet 20 has an outer edge 20E. The outer edge 20E includes one or more corners 20C. In the example shown in Figure 1, the light controlling sheet 20 has a rectangular shape. The light controlling sheet 20 has four corners 20C. The corners 20C have an arc shape with a center of curvature located within the light controlling sheet 20. The corners 20C may have an arc shape over the entire corner 20C, or only part of the corner 20C may have an arc shape.

[0019] In the example shown in FIG. 1, the transparent member 10 has a rectangular shape, similar to the light controlling sheet 20. The transparent member 10 is larger than the light controlling sheet 20. Therefore, the outer edge 20E of the light controlling sheet 20 is located inside the transparent member 10. The transparent member 10 has four corners 10C. Each corner 10C is a right angle. That is, the corner 10C is composed of a first straight line and a second straight line.

[0020] The light controlling sheet 20 is attached to the transparent member 10 so that each corner 20C is aligned in one direction with one corner 10C of the transparent member 10. The corner 20C of the light controlling sheet 20 and the corner 10C of the transparent member 10 are aligned at an interval along the direction in which the diagonal line of the transparent member 10 extends.

[0021] FIG. 2 shows the cross-sectional structure of the light controlling sheet 20 along a plane including a diagonal line of the transparent member 10, and includes a corner portion 20C. As shown in FIG. 2, the light-controlling sheet 20 includes a first transparent conductive sheet, a second transparent conductive sheet, and a light-controlling layer 23. The light-controlling layer 23 is located between the first transparent conductive sheet and the second transparent conductive sheet. In the example shown in FIG. 2, the first transparent conductive sheet includes a first transparent substrate 21A and a first transparent electrode layer 22A. The first transparent substrate 21A supports the first transparent electrode layer 22A. The second transparent conductive sheet includes a second transparent substrate 21B and a second transparent electrode layer 22B. The second transparent substrate 21B supports the second transparent electrode layer 22B. The light-controlling layer 23 is sandwiched between the first transparent electrode layer 22A and the second transparent electrode layer 22B. The first transparent substrate 21A and the second transparent substrate 21B sandwich a pair of transparent electrode layers 22A and 22B.

[0022] In the light-controlling sheet 20, the state of light transmitted through the light-controlling layer 23 changes depending on the voltage applied between the first transparent conductive sheet and the second transparent conductive sheet. An example of the light-controlling layer 23 includes a transparent polymer layer having a plurality of voids and a liquid crystal composition located in the voids. When a voltage is applied between the pair of transparent electrode layers 22A and 22B, the light-controlling sheet 20 becomes transparent, for example. On the other hand, when no voltage is applied between the pair of transparent electrode layers 22A and 22B, the light-controlling sheet 20 becomes opaque.

[0023] The diffuse transmittance of light transmitted through the light-modulating layer 23 differs between when the light-modulating sheet 20 is transparent and when it is opaque. When the light-modulating sheet 20 is transparent, the light-modulating sheet 20 has a first haze value. When the light-modulating sheet 20 is opaque, the light-modulating sheet 20 has a second haze value. The second haze value is higher than the first haze value.

[0024] At the corner 20C of the light controlling sheet 20, an arc-shaped outline whose center of curvature is located within the light controlling sheet 20 continues in the thickness direction of the light controlling sheet 20. That is, at the end face of the light controlling sheet 20, the first transparent conductive sheet, the second transparent conductive sheet, and the light controlling layer 23 included in the light controlling sheet 20 are flush with one another. When viewed from a viewpoint opposite to the plane in which the light controlling sheet 20 extends, the end face of the light controlling sheet 20 connects opposing surfaces of the light controlling sheet 20. At the corner 20C of the light controlling sheet 20, the end face of the light controlling sheet 20 includes an arc-shaped surface whose center of curvature is located within the light controlling sheet 20.

[0025] The light controlling sheet 20 further includes an adhesive layer 28. The adhesive layer 28 is located between the second transparent substrate 21B and the transparent member 10. The light controlling sheet 20 is attached to the transparent member 10 by the adhesive layer 28.

[0026] According to the light controlling sheet 20 of the present disclosure, at the corners 20C of the light controlling sheet 20, the arc-shaped contours are continuous in the thickness direction of the light controlling sheet 20. Therefore, stress is less likely to concentrate at the corners 20C than in a contour in which two straight lines intersecting at one point are continuous in the thickness direction of the light controlling sheet 20. This prevents peeling starting from the corners 20C. That is, in the light controlling sheet 20, peeling of the adhesive layer 28 from the transparent member 10 and peeling between layers of the light controlling sheet 20 are both prevented.

[0027] The radius of curvature of the outer shape of the corner 20C of the light controlling sheet 20 may be 1 mm or more and 10 mm or less. A radius of curvature of 1 mm or more prevents a decrease in the accuracy of the shape of the corner 20C. Furthermore, a radius of curvature of 10 mm or less prevents the corner 20C from becoming too smooth.

[0028] The material for forming each of the transparent substrates 21A and 21B may be a synthetic resin or an inorganic compound. Examples of synthetic resins include polyester, polyacrylate, polycarbonate, and polyolefin. Examples of polyesters include polyethylene terephthalate and polyethylene naphthalate. Examples of polyacrylates include polymethyl methacrylate. Examples of inorganic compounds include silicon dioxide, silicon oxynitride, and silicon nitride.

[0029] The material for forming each of the transparent electrode layers 22A and 22B may be any one selected from the group consisting of indium tin oxide, fluorine-doped tin oxide, tin oxide, zinc oxide, carbon nanotubes, and poly(3,4-ethylenedioxythiophene).

[0030] The material for forming adhesive layer 28 has photocuring or thermosetting properties and may be at least one selected from the group consisting of polyolefin resins, polystyrene resins, polyamide resins, polyester resins, polyvinyl resins, polycarbonate resins, polyacrylate resins, polyurethane resins, and silicone resins.

[0031] The material for forming the transparent member 10 may include, for example, glass, acrylic resin, or polycarbonate resin. The thickness of the transparent member 10 is greater than the thickness of the light controlling sheet 20.

[0032] 3, the light controlling sheet 20 may include a sealing portion 24. The sealing portion 24 covers the edge surface of the light controlling sheet 20 and a portion of the surface of the first transparent base material 21A that is continuous with the edge surface of the light controlling sheet 20. The edge surface of the light controlling sheet 20 includes a surface of each transparent base material 21A, 21B extending along the thickness direction, a surface of each transparent electrode layer 22A, 22B extending along the thickness direction, a surface of the light controlling layer 23 extending along the thickness direction, and a surface of the adhesive layer 28 extending along the thickness direction.

[0033] When the light controlling sheet 20 has the sealing portion 24, it is possible to prevent moisture and the like from penetrating from the end face of the light controlling sheet 20 to the light controlling layer 23. This prevents deterioration of the light controlling layer 23. The material forming the sealing portion 24 may be photocurable or thermosetting, and may be at least one selected from the group consisting of polyacrylate resins, epoxy resins, allyl resins, polyurethane resins, and silicone resins.

[0034] [Method of manufacturing the light controlling sheet 20] The manufacturing method of the light control sheet 20 includes forming a pre-cut sheet of the light control sheet 20 and forming a light control sheet 20 with an outer edge 20E. In forming the pre-cut sheet of the light control sheet 20, a light control layer 23 is formed between the first transparent conductive sheet and the second transparent conductive sheet. In forming the light control sheet 20 with the outer edge 20E, the pre-cut sheet is cut with a cutting blade extending from the first transparent conductive sheet to the second transparent conductive sheet so that it has a predetermined outer edge 20E when viewed from a viewpoint opposite to the plane in which the pre-cut sheet extends. Forming the light control sheet 20 with the outer edge 20E includes forming the light control sheet 20 with the outer edge 20E including one or more corners 20C, where the corners 20C have an arc-shaped outline whose center of curvature is located within the light control sheet 20 and are connected in the thickness direction of the light control sheet 20.

[0035] In the step of forming the pre-cut sheets of the light-controlling sheet 20, a pair of transparent substrates on which a transparent electrode layer is formed is prepared. When the light-controlling layer 23 contains the above-mentioned transparent polymer layer and liquid crystal composition, a coating liquid for forming the light-controlling layer 23 is prepared. The coating liquid contains a polymerizable compound for forming the transparent polymer layer and a liquid crystal compound. In the coating film, the blending ratio of the liquid crystal compound may be, for example, 40% by mass or more and 60% by mass or less, and the blending ratio of the polymerizable compound may be, for example, 40% by mass or more and 60% by mass or less. The coating liquid may contain a dichroic dye.

[0036] Next, a coating film is formed between the transparent electrode layer of the first transparent substrate and the transparent electrode layer of the second transparent substrate using a coating liquid. Subsequently, with the coating film sandwiched between the pair of transparent electrode layers, the coating film is irradiated with light to cure the polymerizable compound. The light to cure the polymerizable compound may be, for example, ultraviolet light. This causes phase separation of the liquid crystal compound from the transparent polymer layer in the coating film. This allows for the production of a light-controlling layer 23 that includes a transparent polymer layer containing voids and a liquid crystal composition located in the voids. As a result, a pre-cut sheet is obtained that includes the light-controlling layer 23 between the first transparent conductive sheet and the second transparent conductive sheet.

[0037] In the process of cutting the pre-cut sheet, a cutting blade is used to cut the pre-cut sheet. An example of a cutting blade is a cutting blade provided in a cutting plotter. The cutting blade is configured to be able to cut the entire pre-cut sheet in the thickness direction of the pre-cut sheet at once. The light-controlling sheet 20 formed by cutting the pre-cut sheet has an outer edge 20E with an arc-shaped corner 20C. Therefore, when cutting the pre-cut sheet, it is possible to cut the pre-cut sheet by simply moving the cutting blade around the outer edge 20E of the light-controlling sheet 20. For example, if the corner 20C has a folded line shape, the cutting plotter must withdraw the cutting blade, change the direction of movement of the cutting edge, and re-insert the cutting blade at each end point of the straight line that constitutes the folded line. In contrast, if the corner 20C has an arc-shaped shape, the cutting plotter can continuously cut the pre-cut sheet with the cutting blade inserted into the pre-cut sheet without needing to move the cutting blade up and down or change the direction of movement of the cutting edge.

[0038] As described above, the light controlling sheet 20 and the method for manufacturing the light controlling sheet 20 can provide the following effects. (1-1) At the corner 20C of the light-adjusting sheet 20, the arc-shaped contour is continuous in the thickness direction of the light-adjusting sheet 20, so stress is less likely to concentrate at the corner 20C than in a contour in which two straight lines intersecting at one point are continuous in the thickness direction of the light-adjusting sheet 20. This prevents peeling from occurring at the corner 20C.

[0039] (1-2) By setting the radius of curvature to 1 mm or more, it is possible to prevent the accuracy of the shape of the corner 20C from decreasing. Furthermore, by setting the radius of curvature to 10 mm or less, it is possible to prevent the corner 20C from becoming too smooth.

[0040] [Second embodiment] A second embodiment of the light controlling sheet 20 and a method for manufacturing the light controlling sheet 20 will be described with reference to Figures 4 to 7. The light controlling sheet 20 of the second embodiment differs from the light controlling sheet 20 of the first embodiment in that the light controlling sheet 20 has layers of different sizes. Therefore, the following will describe in detail the differences between the light controlling sheet 20 of the second embodiment and the light controlling sheet 20 of the first embodiment, while omitting a description of the configuration of the light controlling sheet 20 of the second embodiment that is common to the light controlling sheet 20 of the first embodiment.

[0041] [Light-adjusting sheet] FIG. 4 shows the planar structure of the light controlling sheet 20 together with the planar structure of the transparent member 10. As shown in Fig. 4, when viewed from a viewpoint opposite to the plane on which the light-controlling sheet 20 extends, the laminate of the first transparent conductive sheet and the light-controlling layer 23 has a first outer edge 20E1, and the second transparent conductive sheet has a second outer edge 20E2. The first outer edge 20E1 is smaller than the second outer edge 20E2 and is located within the second outer edge 20E2. In the example shown in Fig. 4, the second outer edge 20E2 has a shape similar to that of the first outer edge 20E1. Both the first outer edge 20E1 and the second outer edge 20E2 have a rectangular shape.

[0042] The first outer edge 20E1 includes a first corner 20C1. The second outer edge 20E2 includes the second corner 20C2. The first corner 20C1 is located within the second outer edge 20E2. In the example shown in FIG. 4, the first outer edge 20E1 includes four first corners 20C1, and the second outer edge 20E2 includes four second corners 20C2. The first corners 20C1 have an arc shape with a center of curvature located within the light controlling sheet 20. The second corners 20C2 have an arc shape with a center of curvature located within the light controlling sheet 20. FIG. 5 is an enlarged view of the light controlling sheet 20 including one first corner 20C1 at the first outer edge 20E1 and one second corner 20C2 at the second outer edge 20E2.

[0043] As shown in Fig. 5, because the first outer edge 20E1 is smaller than the second outer edge 20E2, a portion of the second transparent electrode layer 22B is exposed to the outside outside the first outer edge 20E1. The first corner 20C1 and the second corner 20C2 are arranged side by side with a gap in one direction. The first corner 20C1 and the second corner 20C2 are arranged side by side with a gap in the direction in which the diagonal line of the light controlling sheet 20 extends. In the example shown in Fig. 5, the radius of curvature of the first corner 20C1 is smaller than the radius of curvature of the second corner 20C2.

[0044] Compared to when the radius of curvature of the first corner portion 20C1 is equal to or greater than the radius of curvature of the second corner portion 20C2, the area in which the state of light incident on the dimming layer 23 can be changed by applying a voltage between the transparent electrode layers 22A and 22B is prevented from becoming smaller.

[0045] Assuming that the positions of the two straight lines connecting to the first corner 20C1 of the first outer edge 20E1 are the same, the smaller the size of the first corner 20C1, the shorter the distance between the first corner 20C1 and the second corner 20C2 can be. Therefore, from the perspective of ensuring an area in the light control sheet 20 that can change the state of light incident on the light control layer 23, it is preferable that the radius of curvature of the first corner 20C1 be small. Therefore, it is preferable that the radius of curvature of the first corner 20C1 be smaller than the radius of curvature of the second corner 20C2.

[0046] FIG. 6 shows the cross-sectional structure of the light controlling sheet 20 along a plane including the diagonal line of the transparent member 10, and includes the first corner portion 20C1 and the second corner portion 20C2. As shown in FIG. 6, the light-controlling sheet 20 includes a first transparent conductive sheet, a second transparent conductive sheet, and a light-controlling layer 23, similar to the light-controlling sheet 20 of the first embodiment. The light-controlling layer 23 is located between the first transparent conductive sheet and the second transparent conductive sheet. In the example shown in FIG. 6, the first transparent conductive sheet includes a first transparent substrate 21A and a first transparent electrode layer 22A. The first transparent substrate 21A supports the first transparent electrode layer 22A. The second transparent conductive sheet includes a second transparent substrate 21B and a second transparent electrode layer 22B. The second transparent substrate 21B supports the second transparent electrode layer 22B. The light-controlling layer 23 is sandwiched between the first transparent electrode layer 22A and the second transparent electrode layer 22B. The first transparent substrate 21A and the second transparent substrate 21B sandwich a pair of transparent electrode layers 22A and 22B.

[0047] The second transparent substrate 21B and the second transparent electrode layer 22B have the same size. The first transparent substrate 21A, the first transparent electrode layer 22A, and the light control layer 23 have the same size. Because the first transparent substrate 21A is smaller than the second transparent substrate 21B, a portion of the second transparent electrode layer 22B supported by the second transparent substrate 21B is exposed from the light control layer 23.

[0048] At the first corner 20C1, an arc-shaped first outer shape continues in the thickness direction of the laminate, with the radius of curvature located within the light controlling sheet 20. At the second corner 20C2, an arc-shaped second outer shape continues in the thickness direction of the second transparent conductive sheet, with the radius of curvature located within the light controlling sheet 20. The radius of curvature of the first outer shape may be smaller than the radius of curvature of the second outer shape.

[0049] That is, at the end surface of the light controlling sheet 20, the first transparent conductive sheet included in the light controlling sheet 20 and the light controlling layer 23 are flush with each other. At the end surface of the light controlling sheet 20, the second transparent conductive sheet included in the light controlling sheet 20 and the adhesive layer 28 are flush with each other. The end surface of the light controlling sheet 20 includes an arc-shaped surface whose center of curvature is located within the light controlling sheet 20 at a first corner 20C1 of the light controlling sheet 20, and also includes an arc-shaped surface whose center of curvature is located within the light controlling sheet 20 at a second corner 20C2 of the light controlling sheet 20.

[0050] According to the light controlling sheet 20 of the present disclosure, the arc-shaped contours are continuous in the thickness direction of the light controlling sheet 20 at both the first corner 20C1 and the second corner 20C2. Therefore, stress is less likely to concentrate at both the first corner 20C1 and the second corner 20C2 compared to a contour in which two straight lines intersecting at one point are continuous in the thickness direction of the light controlling sheet 20. This reduces the likelihood of peeling starting from the corners 20C1 and 20C2.

[0051] The radius of curvature of the second outer shape may be, for example, 1 mm or more and 10 mm or less, and the radius of curvature of the first outer shape may be, for example, 0.5 mm or more and 5 mm or less. By making the radius of curvature of the second outer shape 1 mm or more and the radius of curvature of the first outer shape 0.5 mm or more, a decrease in the accuracy of the shape of each corner 20C1, 20C2 is suppressed. Furthermore, by making the radius of curvature of the second outer shape 10 mm or less and the radius of curvature of the first outer shape 5 mm or less, each corner 20C1, 20C2 is suppressed from becoming too gentle.

[0052] The sealing portion 24 covers the edge surface of the first transparent conductive sheet and the edge surface of the light-controlling layer 23, which are the edge surfaces of the light-controlling sheet 20. The sealing portion 24 also covers the portion of the second transparent electrode layer 22B that is exposed from the light-controlling layer 23 and the portion of the first transparent base material 21A that is continuous with the edge surface of the light-controlling sheet 20.

[0053] As shown in FIG. 7, the light-controlling sheet 20 may include, for example, a functional layer 25. The functional layer 25 is included in the first transparent conductive sheet. The functional layer 25 may be, for example, a hard coat layer, an ultraviolet absorbing layer, or an infrared absorbing layer. If the functional layer 25 is a hard coat layer, scratches on the surface of the light-controlling sheet 20 are reduced. If the functional layer 25 is an ultraviolet absorbing layer, the amount of ultraviolet light incident on the light-controlling sheet 20 is reduced, thereby reducing deterioration of the light-controlling sheet 20. If the functional layer 25 is an infrared absorbing layer, the amount of infrared light incident on the light-controlling sheet 20 is reduced, thereby reducing deterioration of the light-controlling sheet 20.

[0054] Furthermore, for example, the light controlling sheet 20 may have a self-adhesive function in the adhesive layer 28. In this case, the adhesive layer 28 may be a single layer or a laminate. The adhesive layer 28 configured as a laminate may be composed of a PET film (core) adhered to the second transparent substrate 21B by another adhesive layer, and a self-adhesive agent coated on the PET film. Furthermore, the other adhesive layer may be a single layer or a laminate. The other adhesive layer configured as a laminate may be configured so that two other adhesive layers sandwich another PET film with a hard coat layer. The light controlling sheet 20 is attached to the transparent member 10 by a self-adhesive agent.

[0055] The self-adhesive properties of the adhesive layer 28 allow the light-adjusting sheet 20 to be peeled off from the transparent member 10 due to external stress and to be re-adhered between the light-adjusting sheet 20 and the transparent member 10. Adhesion by the self-adhesion of the adhesive layer 28 does not require processing such as heating or drying when the adhesive layer 28 is in contact with the light-adjusting sheet 20 and the transparent member 10. Furthermore, adhesion by the self-adhesion of the adhesive layer 28 adheres the light-adjusting sheet 20 to the transparent member 10 by the weight of the light-adjusting sheet 20, without pressing the light-adjusting sheet 20 against the transparent member 10. The adhesive layer 28 makes it easy to peel the light-adjusting sheet 20 from the transparent member 10 and to re-adhere the light-adjusting sheet 20 to the transparent member 10.

[0056] [Method of manufacturing the light controlling sheet 20] The manufacturing method of the light controlling sheet 20 includes forming a pre-cut sheet of the light controlling sheet 20 and forming a light controlling sheet 20 having a first outer edge 20E1 and a second outer edge 20E2. Forming the pre-cut sheet of the light controlling sheet 20 is similar to forming the pre-cut sheet of the light controlling sheet 20 in the first embodiment.

[0057] To form the light control sheet 20 having the first outer edge 20E1 and the second outer edge 20E2, the pre-cut sheet is cut with a cutting blade that extends from the first transparent conductive sheet to the second transparent conductive sheet. The pre-cut sheet is cut so as to have the predetermined second outer edge 20E2 when viewed from a viewpoint opposite to the plane in which the pre-cut sheet extends. Next, in the pre-cut sheet having the second outer edge 20E2, the first transparent conductive sheet and the light control layer 23 are cut with the cutting blade so as to have the predetermined first outer edge 20E1.

[0058] In this case, forming the pre-cut sheet having the first outer edge 20E1 forms the first outer edge 20E1 including one or more first corners 20C1. The first outer edge 20E1 includes the first corners 20C1 so that an arc-shaped first contour having a center of curvature located within the light controlling sheet 20 is continuous in the thickness direction of the light controlling sheet 20.

[0059] Furthermore, the formation of the light controlling sheet 20 having the second outer edge 20E2 forms the second outer edge 20E2 including one or more second corners 20C2. The second outer edge 20E2 includes the second corners 20C2 so that an arc-shaped second contour having a center of curvature located within the light controlling sheet 20 is continuous in the thickness direction of the light controlling sheet 20.

[0060] In the process of cutting the pre-cut sheet, a cutting blade is used to cut the pre-cut sheet. An example of a cutting blade is a cutting blade provided in a cutting plotter. The cutting blade is configured to be able to cut the entire pre-cut sheet in the thickness direction of the pre-cut sheet at once. In the light controlling sheet 20 formed by cutting the pre-cut sheet, the second outer edge 20E2 has an arc-shaped second corner portion 20C2. Therefore, when cutting the pre-cut sheet, it is possible to cut the pre-cut sheet by simply moving the cutting blade around once along the second outer edge 20E2 of the light controlling sheet 20.

[0061] Furthermore, in the process of cutting the pre-cut sheet having the second outer edge 20E2, the pre-cut sheet having the second outer edge 20E2 is cut by a cutting blade provided in a cutting plotter, similar to the case of forming the second outer edge 20E2 in the pre-cut sheet. The cutting blade is configured to be able to cut the first transparent conductive sheet and the light-controlling layer 23 at once in the thickness direction of the pre-cut sheet. In the light-controlling sheet 20 formed by cutting the pre-cut sheet, the first outer edge 20E1 has an arc-shaped first corner portion 20C1. Therefore, when cutting the pre-cut sheet, it is possible to cut the pre-cut sheet by simply moving the cutting blade around once along the first outer edge 20E1 of the light-controlling sheet 20.

[0062] As described above, according to the light controlling sheet 20 and the manufacturing method for the light controlling sheet 20 of the second embodiment, the following effects can be obtained. (2-1) At both the first corner 20C1 and the second corner 20C2, the arc-shaped contours are continuous in the thickness direction of the light controlling sheet 20. Therefore, stress is less likely to concentrate at both the first corner 20C1 and the second corner 20C2 than in a contour in which two straight lines intersecting at one point are continuous in the thickness direction of the light controlling sheet 20. This reduces the likelihood of peeling starting from the corners 20C1 and 20C2.

[0063] (2-2) Compared to when the radius of curvature of the first outer shape is equal to or greater than the radius of curvature of the second outer shape, the area in which the state of light incident on the dimming layer 23 can be changed by applying a voltage between the transparent electrode layers 22A and 22B is prevented from becoming smaller.

[0064] (2-3) The radius of curvature of the second outer shape is 1 mm or more, and the radius of curvature of the first outer shape is 0.5 mm or more, thereby preventing a decrease in the accuracy of the shape of each corner 20C1, 20C2. Furthermore, the radius of curvature of the second outer shape is 10 mm or less, and the radius of curvature of the first outer shape is 5 mm or less, thereby preventing each corner 20C1, 20C2 from becoming too smooth.

[0065] [Example of change] The above-described embodiments can be modified as follows. [Feature Layer] The light controlling sheet 20 of the first embodiment may include a functional layer 25, similar to the light controlling sheet 20 of the second embodiment. This provides the light controlling sheet 20 with the effects of the functional layer 25. The functional layer 25 may also be disposed between the second transparent substrate 21B and the adhesive layer 28.

[0066] The functional layer 25 may be a laminate including two or more layers selected from the group consisting of a hard coat layer, an ultraviolet absorbing layer, and an infrared absorbing layer. The functional layer 25 may be composed of, for example, a PET film having a hard coat layer laminated thereon and an adhesive layer made of a UV-blocking adhesive for bonding the first transparent substrate 21A to the PET film. The functional layer 25 may be composed of, for example, a PET film having a hard coat layer laminated thereon and an adhesive layer made of a UV-blocking adhesive for bonding the second transparent substrate 21B to the PET film.

[0067] [Adhesive layer] The light controlling sheet 20 of the first embodiment may include an adhesive layer 28, similar to the light controlling sheet 20 of the second embodiment. The adhesive layer 28 may be composed of a PET film adhered to the hard coat layer of the functional layer 25 by an adhesive layer, and a self-adhesive agent coated on the PET film.

[0068] [Alignment layer] The light-controlling sheet 20 of each embodiment may include a pair of alignment layers. In this case, the first alignment layer is located between the light-controlling layer 23 and the first transparent electrode layer 22A, and the second alignment layer is located between the light-controlling layer 23 and the second transparent electrode layer 22B. Each alignment layer may be a vertical alignment layer. In this case, the light-controlling sheet 20 is transparent when no voltage is applied between the pair of transparent electrode layers 22A and 22B, and is opaque when a voltage is applied between them.

[0069] [First outer edge] The first outer edge 20E1 may have only a portion located within the second outer edge 20E2, while another portion of the first outer edge 20E1 overlaps the second outer edge 20E2. In this case, the first outer edge 20E1 only needs to have the first corner 20C1 at the portion of the first outer edge 20E1 located within the second outer edge 20E2. [Explanation of symbols]

[0070] 10...Transparent material 10C,20C…corner 20...Light-adjusting sheet 20E…outer edge 21A...First transparent base material 21B...Second transparent base material 22A...first transparent electrode layer 22B...Second transparent electrode layer 23...Photochromic layer 24...Sealing part 25...Functional layer 28…adhesive layer

Claims

1. a first transparent conductive sheet; A second transparent conductive sheet; a light-control layer located between the first transparent conductive sheet and the second transparent conductive sheet, A light-controlling sheet in which the state of light transmitted through the light-controlling layer changes in response to application of a voltage between the first transparent conductive sheet and the second transparent conductive sheet, When viewed from a viewpoint opposite to a plane on which the light controlling sheet extends, the light controlling sheet has an outer edge, the outer edge includes one or more corners; At the corner, an arc-shaped contour having a curvature center located within the light-controlling sheet is continuous in the thickness direction of the light-controlling sheet. Dimming sheet.

2. The radius of curvature of the outer shape is 1 mm or more and 10 mm or less. The light-controlling sheet according to claim 1 .

3. a first transparent conductive sheet; A second transparent conductive sheet; a light-control layer located between the first transparent conductive sheet and the second transparent conductive sheet, A light-controlling sheet in which the state of light transmitted through the light-controlling layer changes in response to application of a voltage between the first transparent conductive sheet and the second transparent conductive sheet, When viewed from a viewpoint opposite to a plane on which the light-controlling sheet extends, a laminate of the first transparent conductive sheet and the light-controlling layer has a first outer edge, the second transparent conductive sheet has a second outer edge, and the first outer edge is smaller than the second outer edge and is located within the second outer edge; the first outer edge includes a first corner portion, the first corner portion being located within the second outer edge; the second outer edge includes a second corner portion, At the first corner portion, an arc-shaped first outer shape having a curvature radius located within the light controlling sheet is continuous in the thickness direction of the laminate, At the second corner, an arc-shaped second contour having a curvature radius positioned within the light-controlling sheet is continuous in the thickness direction of the second transparent conductive sheet. Dimming sheet.

4. the first corner portion and the second corner portion are arranged at an interval in one direction, The radius of curvature of the first outer shape is smaller than the radius of curvature of the second outer shape. The light-controlling sheet according to claim 3 .

5. The radius of curvature of the second outer shape is 1 mm or more and 10 mm or less, The radius of curvature of the first outer shape is 0.5 mm or more and 5 mm or less. The light-controlling sheet according to claim 4 .

6. a first transparent conductive sheet; A second transparent conductive sheet; a light-control layer located between the first transparent conductive sheet and the second transparent conductive sheet, A method for manufacturing a light-controlling sheet in which the state of light transmitted through the light-controlling layer changes in response to application of a voltage between the first transparent conductive sheet and the second transparent conductive sheet, forming the light-controlling layer between the first transparent conductive sheet and the second transparent conductive sheet to form a pre-cut sheet of the light-controlling sheet; forming the light-controlling sheet having a predetermined outer edge by cutting the pre-cut sheet with a cutting blade extending from the first transparent conductive sheet to the second transparent conductive sheet so that the pre-cut sheet has the predetermined outer edge when viewed from a viewpoint opposite to a plane in which the pre-cut sheet extends, Forming the light-regulating sheet having the outer edge includes forming the light-regulating sheet having the outer edge including one or more corners, the corners having an arc-shaped contour with a center of curvature located within the light-regulating sheet, the arc-shaped contour continuing in the thickness direction of the light-regulating sheet. A method for manufacturing light-controlling sheets.

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