Light-adjusting sheet

Abstract

To provide a lighting control sheet that can increase the design of the lighting control sheet.SOLUTION: A lighting control sheet comprises: a first connection area 24A that includes a first terminal part 50A applying voltage to a first transparent electrode layer and is edged by a portion exposed from a lighting control layer in the first transparent electrode layer; and a second connection area that includes a second terminal part applying voltage to a second transparent electrode layer and is edged by a portion exposed from the lighting control layer in the second transparent electrode layer. The first transparent electrode layer includes grooves 120 that extend along a support surface and penetrate the first transparent electrode layer, a drive electrode element 30 that is applied with voltage, and a floating electrode element 31 that is an area surrounded by the grooves 120 and insulated from the drive electrode element 30 by the grooves 120. A direction in which the first connection area 24A and the second connection area are arranged side by side is a first direction. The shortest distance between a first straight line SL1 passing through the first connection area 24A along the first direction and a second straight line SL2 passing through the grooves 120 along the first direction is 5 mm or more and 50 mm or less.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a light controlling sheet. [Background technology]

[0002] A light-controlling sheet comprises a light-controlling layer containing a liquid crystal composition and a pair of transparent electrode layers sandwiching the light-controlling layer. A driving voltage is applied between the pair of transparent electrode layers. The orientation state of the liquid crystal molecules changes depending on the potential difference between the transparent electrode layers, which in turn changes the diffuse transmittance of the light-controlling sheet. For example, when the long axis direction of the liquid crystal molecules is aligned with the thickness direction of the light-controlling layer, the diffuse transmittance of the light-controlling sheet is relatively low and the light-controlling sheet is transparent. In contrast, when the long axis direction of the liquid crystal molecules intersects with the thickness direction of the light-controlling layer, the diffuse transmittance of the light-controlling sheet is relatively high and the light-controlling sheet is opaque (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-45135 Summary of the Invention [Problem to be solved by the invention]

[0004] Light-controlling sheets are attached to space-dividing components, such as building windows, partitions, and vehicle windows, and are used as part of the space-dividing components. In recent years, attention has been focused on the design of light-controlling sheets in order to increase the added value of light-controlling sheets. Improving the design of light-controlling sheets can greatly expand the range of application of light-controlling sheets and can also create new demand for light-controlling spaces. For this reason, there is a demand for light-controlling sheets that enable enhanced design. [Means for solving the problem]

[0005] A light-controlling sheet that solves the above problem includes a first transparent electrode layer, a second transparent electrode layer, a light-controlling layer located between the first transparent electrode layer and the second transparent electrode layer, and a first transparent support layer located on the opposite side of the first transparent electrode layer from the light-controlling layer, the first transparent support layer having a support surface that supports the first transparent electrode layer. The light-controlling sheet includes: a first connection region that includes a first terminal unit that applies a voltage to the first transparent electrode layer and is bordered by a portion of the first transparent electrode layer that is exposed from the light-controlling layer; and a second connection region that includes a second terminal unit that applies a voltage to the second transparent electrode layer and is bordered by a portion of the second transparent electrode layer that is exposed from the light-controlling layer. The first transparent electrode layer includes a groove that extends along the support surface and penetrates the first transparent electrode layer, a driving electrode element to which the voltage is applied, and a floating electrode element that is insulated from the driving electrode element by the groove in an area surrounded by the groove. The direction in which the first connection region and the second connection region are aligned is the first direction, and the shortest distance between a straight line passing through the first connection region along the first direction and a straight line passing through the groove along the first direction is 5 mm or more and 50 mm or less.

[0006] According to the light-controlling sheet, the shortest distance between the line passing through the first connection region and the line passing through the groove is 5 mm or more. Therefore, even if the floating electrode element is disposed near the first connection region where the shortest distance is 50 mm or less, an increase in the resistance value in the portion of the drive electrode element located between the first connection region and the floating electrode element is suppressed. This prevents a decrease in the effective voltage applied to the portion of the drive electrode element that is farther away from the first connection region than the floating electrode element. This makes it possible to change the optical properties of the entire light-controlling sheet depending on whether or not a voltage is applied between the transparent electrode layers, thereby improving the design of the light-controlling sheet.

[0007] In the light controlling sheet, an area of ​​the first transparent electrode layer adjacent to the first connection area is a unit area, the unit area extends along the first direction and is separated from the first connection area by the straight line passing through the first connection area, the length of the unit area in the first direction is 100 mm, the length of the unit area in a second direction perpendicular to the first direction is 100 mm, and in the unit area, the percentage of the area of ​​the floating electrode element to the sum of the area of ​​the driving electrode element and the area of ​​the floating electrode element may be 30% or more. This light controlling sheet can improve the effectiveness of having the shortest distance between the straight line passing through the first connection area and the straight line passing through the groove be 5 mm or more.

[0008] In the light controlling sheet, the first transparent electrode layer may have a narrowed portion sandwiched between the grooves, and the narrowed portion may have a width of 1 mm or more. With this light controlling sheet, it is possible to apply a voltage through the narrowed portion to a connection destination of the narrowed portion, and therefore it is possible to change the optical properties of the connection destination of the narrowed portion depending on whether or not a voltage is applied through the narrowed portion.

[0009] In the above-mentioned light-controlling sheet, the light-controlling layer contains a liquid crystal composition, and the grooves may penetrate the first transparent electrode layer in the thickness direction of the light-controlling sheet and extend halfway through the first transparent support layer, and the liquid crystal composition may be located within the grooves.

[0010] According to the above-mentioned light controlling sheet, since the liquid crystal composition is located in the grooves, when no voltage is applied between the transparent electrode layers, it is possible to reduce the difference in diffuse transmittance between the grooves and the areas other than the grooves in the light controlling sheet, thereby reducing the visibility of the grooves.

[0011] In the above-mentioned light-controlling sheet, the light-controlling layer may contain a liquid crystal composition, the groove may penetrate through the first transparent electrode layer and the first transparent support layer in the thickness direction of the light-controlling sheet, and the liquid crystal composition may be located within the groove.

[0012] According to the above-mentioned light controlling sheet, since the liquid crystal composition is located in the grooves, when no voltage is applied between the transparent electrode layers, it is possible to reduce the difference in diffuse transmittance between the grooves and the areas other than the grooves in the light controlling sheet, thereby reducing the visibility of the grooves. [Effects of the Invention]

[0013] According to the present invention, the design of the light controlling sheet can be improved. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a front view of a normal-type light controlling sheet in the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] 2 is an enlarged plan view showing a part of the light controlling sheet shown in FIG. 1. FIG. [Figure 5] 2 is an enlarged plan view showing a part of the light controlling sheet shown in FIG. 1. FIG. [Figure 6] 2 is an enlarged plan view showing a part of the light controlling sheet shown in FIG. 1. FIG. [Figure 7] 3A to 3C are diagrams schematically showing a method for manufacturing the light controlling sheet of the same embodiment. [Figure 8] FIG. 2 is a front view of the light controlling sheet in a non-driven state in the same embodiment. [Figure 9] FIG. 10 is a cross-sectional view of a light controlling sheet according to a second embodiment. [Figure 10] FIG. 10 is a front view of a light controlling sheet according to a modified example. [Figure 11] FIG. 10 is a front view of a modified reverse-type light controlling sheet. [Figure 12] FIG. 10 is a cross-sectional view of a modified example of the light controlling sheet. [Figure 13] FIG. 10 is a cross-sectional view of a modified example of the light controlling sheet. [Figure 14] FIG. 10 is a cross-sectional view of a modified example of the light controlling sheet. [Figure 15]FIG. 10 is a front view of a light controlling sheet according to a modified example. [Figure 16] FIG. 10 is a front view of a light controlling sheet according to a modified example. [Figure 17] FIG. 2 is a plan view showing the shape of a measurement sample for measuring a resistance value. [Figure 18] 10 is a table showing resistance values ​​of test examples. [Figure 19] 10 is a table showing effective voltages in test examples. [Figure 20] 1 is a table showing the peel strength of test examples. [Figure 21] 1 is a graph showing the relationship between the peel strength of a test piece and the peel strength per unit length. DETAILED DESCRIPTION OF THE INVENTION

[0015] [First embodiment] A first embodiment of a light controlling sheet will be described with reference to Figures 1 to 8. The light controlling sheet 10 of this embodiment is a normal type. The normal type light controlling sheet 10 increases the scattering of incident light in the region to be driven when no voltage signal is applied to the light controlling sheet 10, and decreases the scattering when a voltage signal is applied to the light controlling sheet 10.

[0016] [Light-adjusting sheet] The planar structure of the light controlling sheet 10 will be described with reference to FIG. 1, the light controlling sheet 10 has a first surface 11F and a second surface 11R that is the surface opposite to the first surface 11F. The light controlling sheet 10 has a driving region 20 and a non-driving region 21.

[0017] The light-controlling sheet 10 has a laminated structure. The driving region 20 is a region that includes a driving electrode element 30 as part of the laminated structure. The driving electrode element 30 is an electrode element to which a voltage signal is applied when the light-controlling sheet 10 is driven. The diffuse transmittance of the driving region 20 changes depending on the state of application of the voltage signal to the driving electrode element 30. The driving electrode element 30 is an example of a first electrode element. The non-driving region 21 is a region that includes a floating electrode element 31 as part of the laminated structure. The floating electrode element 31 is an electrode element to which a voltage signal is not applied when the light-controlling sheet 10 is driven. The floating electrode element 31 is an example of a second electrode element. The diffuse transmittance of the driving region 20 changes depending on the state of application of a voltage signal to the light-controlling sheet 10, while the diffuse transmittance of the non-driving region 21 does not change depending on the state of application of a voltage signal to the light-controlling sheet 10. In the example shown in Figure 1, the non-driving region 21 is arranged along the pattern. The design may be, for example, one or a combination of two or more of letters, numbers, symbols, figures, pictures, patterns, and the like.

[0018] The non-drive region 21 shown in FIG. 1 has a shape like a long, thin line. The non-drive region 21 is bent at multiple locations between the first end 21A and the second end 21B. The non-drive region 21 divides the drive region 20 into a second drive region 20B having a predetermined pattern shape and a first drive region 20A located outside the second drive region 20B. Furthermore, in the non-drive region 21, parts of the non-drive region 21 do not contact or intersect with other parts between the first end 21A and the second end 21B, and a distance of at least a predetermined distance is maintained between parts of the non-drive region 21 throughout the non-drive region 21. In the example shown in FIG. 1, even in region 101 where parts of the non-drive region 21 are close to each other, a distance is maintained between parts of the non-drive region 21.

[0019] Each of the driving regions 20A, 20B defined by the non-driving region 21 is sandwiched by the groove 120 (see FIG. 3 ), i.e., electrically connected via a narrowed portion 30A located between the first and second portions of the groove 120. The narrowed portion 30A is an example of an inter-groove region. In other words, the driving electrode element 30 includes the narrowed portion 30A included in the conductive portion 26. The conductive portion 26 is sandwiched between the first and second portions of the non-driving region 21, which include the groove 120 and the floating electrode element 31, and connects the first driving region 20A to the second driving region 20B. The width of the conductive portion 26, i.e., the width of the narrowed portion 30A, is narrower than the widths of the driving regions 20A, 20B. The non-driving region 21 and the conductive portion 26 surround the second driving region 20B. The first driving region 20A is an example of an outer region, and the second driving region 20B is an example of an inner region.

[0020] The light controlling sheet 10 has two connection regions 24. The connection regions 24 are regions for applying voltage signals to the driving regions 20. External wiring 25 is connected to the connection regions 24. The connection regions 24 and the driving regions 20 are adjacent to each other, and thus the driving regions 20 are connected to the connection regions 24.

[0021] One connection region 24 is a first connection region 24A, and the other connection region 24 is a second connection region 24B. The second connection region 24B is exposed to the outside of the light controlling sheet 10 when viewed from a viewpoint facing the first surface 11F of the light controlling sheet 10. The first connection region 24A is exposed to the outside of the light controlling sheet 10 when viewed from a viewpoint facing the second surface 11R of the light controlling sheet 10. The first connection region 24A and the second connection region 24B are aligned along the edge of the light controlling sheet 10. The direction in which the first connection region 24A and the second connection region 24B are aligned is the first direction.

[0022] When a voltage signal is applied to the light-adjusting sheet 10 via the connection region 24, the diffuse transmittance of the driving regions 20A and 20B becomes lower than when no voltage signal is applied to the light-adjusting sheet 10. On the other hand, even when a voltage signal is applied to the light-adjusting sheet 10, the diffuse transmittance of the non-driving region 21 does not change. As a result, a pattern 100 defined by the linear non-driving region 21 appears on the light-adjusting sheet 10. At this time, the diffuse transmittance is lowered in the second driving region 20B surrounded by the non-driving region 21, so that the so-called "white" pattern 100 is displayed. Note that although the light-adjusting sheet 10 shown in FIG. 1 displays one pattern using the non-driving region 21, multiple patterns may also be displayed. In other words, the light-adjusting sheet 10 may have multiple independent non-driving regions 21 that are not connected to each other.

[0023] The layered structure of the light controlling sheet 10 will be described with reference to Figures 2 and 3. Figure 2 is a cross-sectional view taken along line II-II in Figure 1, showing the cross-sectional structure of the light controlling sheet 10 in part of the driving region 20 and the connection region 24. Note that the thickness ratios of the layers in Figure 2 are shown for the sake of convenience, and the thickness ratios of the layers are not limited to those shown in the figure.

[0024] As shown in FIG. 2, the light-controlling sheet 10 has a light-controlling layer 11, a first transparent electrode layer 12A, a second transparent electrode layer 12B, a first transparent support layer 13A, and a second transparent support layer 13B. The light-controlling layer 11 is sandwiched between the first transparent electrode layer 12A and the second transparent electrode layer 12B. The first transparent support layer 13A supports the surface of the first transparent electrode layer 12A opposite to the surface that contacts the light-controlling layer 11 with a support surface 130 that is a single continuous surface. The second transparent support layer 13B supports the surface of the second transparent electrode layer 12B opposite to the surface that contacts the light-controlling layer 11. The light-controlling layer 11 may have a single-layer structure or a multi-layer structure. The multilayered dimming layer 11 may include, for example, a functional layer having a dimming function and a functional layer that enhances adhesion between the functional layer and the first transparent electrode layer 12A and between the functional layer and the second transparent electrode layer 12B.

[0025] The light controlling sheet 10 further includes a protective layer 44. The protective layer 44 is located on the opposite side of the first transparent support layer 13A from the first transparent electrode layer 12A. The protective layer 44 may be fixed to the first transparent support layer 13A via an adhesive layer (not shown).

[0026] The first surface 11F of the light-controlling sheet 10 is the surface of the protective layer 44 opposite the surface facing the first transparent support layer 13A. The second surface 11R of the light-controlling sheet 10 is the surface of the second transparent support layer 13B opposite the surface facing the second transparent electrode layer 12B. The second surface 11R is attached to a transparent plate made of glass, resin, or the like via an adhesive layer (not shown). Examples of transparent plates include window glass found in various buildings such as homes, stores, stations, and airports, partitions installed in offices, show windows installed in stores, and window glass or windshields found in moving objects such as vehicles and aircraft. Each surface of the transparent plate may be flat or curved.

[0027] As described above, the connection region 24 includes the first connection region 24A and the second connection region 24B. The first connection region 24A is connected to an external wiring 25 for applying a voltage signal to the first transparent electrode layer 12A. The second connection region 24B is connected to an external wiring 25 for applying a voltage signal to the second transparent electrode layer 12B.

[0028] The light control layer 11, the second transparent electrode layer 12B, and the second transparent support layer 13B are not located in the first connection region 24A, so that a portion of the first transparent electrode layer 12A is exposed to the outside. A first terminal 50A is connected to the portion of the first transparent electrode layer 12A exposed in the first connection region 24A. That is, the driving electrode element 30 extends from the driving region 20 to the first connection region 24A, and the first terminal 50A is connected to the driving electrode element 30 in the first connection region 24A. That is, the first transparent electrode layer 12A includes the driving electrode element 30, the driving region 20 includes a portion of the driving electrode element 30, and the first connection region 24A includes another portion of the driving electrode element 30.

[0029] The second connection region 24B is free from the light control layer 11, the first transparent electrode layer 12A, the first transparent support layer 13A, and the protective layer 44, thereby exposing a portion of the second transparent electrode layer 12B. The second terminal 50B is connected to the portion of the second transparent electrode layer 12B exposed in the second connection region 24B.

[0030] An external wiring 25 is connected to each of the first terminal 50A and the second terminal 50B. Each external wiring 25 is connected to a control unit 50. The control unit 50 applies a voltage signal to the driving electrode element 30 of the first transparent electrode layer 12A through the first terminal 50A, and applies a voltage signal to the second transparent electrode layer 12B through the second terminal 50B. In this way, the control unit 50 controls the potential difference between the first transparent electrode layer 12A and the second transparent electrode layer 12B in the driving region 20. The second transparent electrode layer 12B is controlled to, for example, ground potential. The light-controlling sheet 10 and the control unit 50 constitute a light-controlling device.

[0031] The light-controlling layer 11 comprises a transparent polymer layer and a liquid crystal composition. The transparent polymer layer has voids into which the liquid crystal composition is filled. The voids in the transparent polymer layer are filled with the liquid crystal composition. The liquid crystal composition contains liquid crystal molecules. An example of the liquid crystal molecules is any one selected from the group consisting of Schiff base-based, azo-based, azoxy-based, biphenyl-based, terphenyl-based, benzoate ester-based, tolan-based, pyrimidine-based, cyclohexane carboxylic acid ester-based, phenylcyclohexane-based, and dioxane-based molecules. When the light-controlling layer 11 has a single-layer structure, the light-controlling layer 11 consists only of a functional layer comprising a transparent polymer layer and a liquid crystal composition.

[0032] The liquid crystal composition can be held in one of three types: a polymer network type, a polymer dispersion type, or an encapsulated type. The polymer network type has a transparent polymer network with a three-dimensional mesh structure. The voids in the mesh are interconnected, and the liquid crystal composition is held in the voids of the mesh. The polymer network is an example of a transparent polymer layer. The polymer dispersion type has a large number of isolated voids in a transparent polymer layer, and the liquid crystal composition is held in the voids dispersed in the polymer layer. The encapsulated type holds the liquid crystal composition in an encapsulated state in a transparent polymer layer. In addition to the liquid crystal molecules described above, the liquid crystal composition may also contain a monomer for forming a transparent polymer layer and a dichroic dye. In the example shown in Figure 2, the light-controlling layer 11 includes a spacer 15. The spacer 15 maintains the thickness of the light-controlling layer 11 within a certain range.

[0033] Each of the first transparent electrode layer 12A and the second transparent electrode layer 12B is conductive and transparent to light in the visible region. Materials for forming the first transparent electrode layer 12A and the second transparent electrode layer 12B include, for example, indium tin oxide, fluorine-doped tin oxide, tin oxide, zinc oxide, carbon nanotubes, and poly(3,4-ethylenedioxythiophene).

[0034] Each of the first transparent support layer 13A and the second transparent support layer 13B is a substrate that is transparent to light in the visible region. Examples of materials for forming the first transparent support layer 13A and the second transparent support layer 13B may be synthetic resins or inorganic compounds. 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.

[0035] Each of the first terminal unit 50A and the second terminal unit 50B includes, for example, a conductive adhesive layer and a wiring substrate. The conductive adhesive layer is formed of, for example, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), an isotropic conductive film (ICF), or an isotropic conductive paste (ICP). The wiring substrate is, for example, a flexible printed circuit (FPC). Alternatively, each of the first terminal unit 50A and the second terminal unit 50B may be made of a conductive material such as conductive tape. When the first terminal unit 50A and the second terminal unit 50B are made of conductive tape, the external wiring 25 may be soldered to the first terminal unit 50A and the second terminal unit 50B.

[0036] In the driving region 20, the orientation of the liquid crystal molecules in the portion of the switchable layer 11 included in the driving region 20 changes in response to a change in voltage generated between the first transparent electrode layer 12A and the second transparent electrode layer 12B. The change in orientation of the liquid crystal molecules changes the degree of scattering, absorption, and transmission of visible light entering the switchable layer 11. Specifically, when no voltage signal is applied to the first transparent electrode layer 12A and the second transparent electrode layer 12B of the driving region 20, the orientation of the long axis direction of the liquid crystal molecules is irregular. As a result, the degree of scattering of light entering the switchable layer 11 increases, and the driving region 20 appears cloudy. In other words, when no voltage signal is applied to the switchable layer 11, the driving region 20 is opaque. On the other hand, when a voltage signal is applied to the first transparent electrode layer 12A and the second transparent electrode layer 12B, causing a potential difference of a predetermined value or more between the first transparent electrode layer 12A and the second transparent electrode layer 12B, the liquid crystal molecules are oriented, with the long axis direction of the liquid crystal molecules aligning with the electric field direction between the first transparent electrode layer 12A and the second transparent electrode layer 12B. As a result, light can easily pass through the light control layer 11, that is, diffusion in the light control layer 11 is suppressed, and the driving region 20 exhibits transparency.

[0037] 3 shows a cross-sectional structure taken along line III-III in FIG. 1. The cross-sectional structure includes the cross-sectional structure of the non-driving region 21. As shown in FIG. 3 , the driving region 20 includes driving electrode elements 30 that are part of the first transparent electrode layer 12A. The non-driving region 21 includes a floating region 22 where the floating electrode elements 31 are located and a boundary region 23 where the grooves 120 are located. The grooves 120 surround the outer edge of the floating electrode elements 31. The boundary region 23 does not include the driving electrode elements 30 and the floating electrode elements 31. The floating region 22 is defined by the boundary region 23 formed by the grooves 120. The driving electrode elements 30 and the floating electrode elements 31 are separate layered bodies aligned along the support surface 130 of the first transparent support layer 13A. In the first transparent electrode layer 12A, the grooves 120 and the floating electrode elements 31 constitute non-driving elements. The portion of the driving electrode elements 30 included in the first driving region 20A is the first driving electrode element, and the portion included in the second driving region 20B is the second driving electrode element.

[0038] The driving electrode elements 30 and the floating electrode elements 31 are separated by grooves 120. In this embodiment, the grooves 120 have openings 122 on the surface of the first transparent electrode layer 12A that contacts the light control layer 11. The grooves 120 penetrate the first transparent electrode layer 12A and extend partway through in the thickness direction of the first transparent support layer 13A. The driving electrode elements 30 and the floating electrode elements 31 are insulated from each other by being separated by the grooves 120.

[0039] The width L2 of the grooves 120 may be smaller than the diameter of the spacers 15. This prevents the spacers 15 from entering the grooves 120. The grooves 120 are filled with a liquid crystal composition. The liquid crystal composition need only fill a portion of the grooves 120, and does not have to fill the entire grooves 120. By filling the grooves 120 with the liquid crystal composition, the grooves 120 are less noticeable when the light controlling sheet 10 is viewed from a viewpoint facing the first surface 11F or a viewpoint facing the second surface 11R while the light controlling sheet 10 is not driven. In other words, because the liquid crystal composition is located in the grooves 120, it is possible to reduce the difference in diffuse transmittance between the grooves 120 and portions of the light controlling sheet 10 other than the grooves 120 when no voltage is applied between the transparent electrode layers 12A and 12B. This prevents the grooves 120 from being visible.

[0040] The non-driven region 21 will be described with reference to Figures 4 and 5. Figure 4 is an enlarged view of region 101 in Figure 1. 4, the conductive portion 26 including the narrowed portion 30A may be positioned so as to connect the first portion and the second portion of the non-driving region 21. Alternatively, the conductive portion 26 may be provided between the first end 21A and the second end 21B. From the viewpoint of ensuring conductivity between the first driving region 20A outside the non-driving region 21 and the second driving region 20B inside the non-driving region 21, the width L1 of the narrowed portion 30A included in the conductive portion 26 may be 1 mm or more.

[0041] 4, in the direction in which the first end 21A of the non-driving region 21 and the opposing portion of the non-driving region 21 that is closest to the first end 21A are aligned, the width L1 between the first end 21A and the opposing portion may be 1 mm or more. That is, in the non-driving region 21, the first portion and the second portion are separated from each other by a portion of the driving region 20. The portion of the driving region 20 that separates the first portion and the second portion of the non-driving region 21 is the conductive portion 26 including the narrowed portion 30A. The narrowed portion 30A is located between a portion of the groove 120 that surrounds a portion of the floating electrode element 31 included in the first portion and a portion of the groove 120 that surrounds a portion of the floating electrode element 31 included in the second portion.

[0042] By making the width L1 of the narrowing portion 30A 1 mm or more, an increase in the resistance value of the narrowing portion 30A is suppressed, thereby suppressing the occurrence of unequal diffuse transmittance in the driving regions 20A and 20B when a driving voltage is applied. For example, even when a driving voltage is applied, the occurrence of the second driving region 20B not changing from an opaque state to a transparent state is suppressed. Furthermore, when a white pattern 100 as shown in FIG. 1 is displayed on the light controlling sheet 10, the width L1 of the narrowing portion 30A may be 30 mm or less from the viewpoint of enhancing the design. By making the width L1 of the narrowing portion 30A 30 mm or less, the desired pattern is easily displayed.

[0043] The narrowed portion 30A is an example of an inter-groove region, a portion of the first transparent electrode layer 12A constricted by the groove 120 that defines the narrowed portion 30A. The peel strength between the narrowed portion 30A and the second transparent electrode layer 12B may be 0.01 N or greater. The peel strength is a value measured in accordance with 6.9.3 a) 180-degree peel test of JIS A 5759:2016, "Films for Architectural Window Glass." Because the peel strength between the narrowed portion 30A and the second transparent electrode layer 12B is 0.01 N or greater, peeling at the portion of the light-controlling sheet 10 that includes the narrowed portion 30A can be suppressed. This suppresses poor electrical conductivity due to peeling, even when the first transparent electrode layer 12A is patterned so that the narrowed portion 30A is formed between the grooves 120 in the first transparent electrode layer 12A, thereby improving the design of the light-controlling sheet 10.

[0044] When the width of the narrowed portion 30A is 2 mm or more, the peel strength between the narrowed portion 30A and the second transparent electrode layer 12B per unit length in the width direction of the narrowed portion 30A may be 0.1 N / 10 mm. In this way, because the peel strength between the narrowed portion 30A and the second transparent electrode layer 12B per unit length is 0.1 N / 10 mm or more, when the light controlling sheet 10 has a narrowed portion 30A with a width of 2 mm or more, peeling is suppressed in the portion including the narrowed portion 30A.

[0045] The peel strength between the inter-groove region and the second transparent electrode layer can be changed, for example, by changing the mechanical strength of the transparent polymer layer included in the light-controlling layer 11. The light-controlling sheet 10 tends to have a higher peel strength as the mechanical strength of the transparent polymer layer increases. The mechanical strength of the transparent polymer layer can be increased by increasing the ratio of the mass of the polymerizable composition to the mass of the liquid crystal in the light-controlling material used to form the light-controlling layer 11. The light-controlling sheet 10 also tends to have a higher peel strength as the adhesion between the transparent polymer layer and the transparent film including the transparent electrode layer increases.

[0046] Furthermore, the non-drive region 21 has a bent portion 102 according to the design 100. The bent portion 102 is a curved or bent portion. As shown in FIG. 4, when the bent portion 102 of the non-drive region 21 is curved, the minimum value of the first angle θ1 formed by the first tangent 105 and the second tangent 106 of the bent portion 102 may be 10 degrees or more. The first tangent 105 is a tangent that is tangent to a first portion of the bent portion 102 on the outside of the bent portion 102, and the second tangent 106 is a tangent that is tangent to a second portion of the bent portion 102 on the outside of the bent portion 102. The first portion and the second portion are set in the bent portion so as to sandwich a bending point included in the bent portion 102. The first portion and the second portion are set so as not to sandwich a part of the drive region 20 between the first portion and the second portion.

[0047] As shown in FIG. 5, the non-driving region 21 may include a bent portion 102 composed of two linear portions sandwiching a bending point. The two linear portions are a first linear portion and a second linear portion. In the bent portion 102, a portion of the driving region 20 is sandwiched between the first linear portion and the second linear portion. The minimum value of the second angle θ2 formed by the first linear portion and the second linear portion may be 10 degrees or greater. Note that the second angle θ2 is the angle formed on the inside of the bent portion 102 between a portion of the groove 120 included in the first linear portion and a portion of the groove 120 included in the second linear portion.

[0048] If the first angle θ1 and the second angle θ2 are less than 10 degrees, there is a possibility that the first transparent support layer 13A and the first transparent electrode layer 12A will peel off from the adjacent layers during or after the process of forming the grooves 120. In contrast, if the first angle θ1 and the second angle θ2 are 10 degrees or greater, peeling of the first transparent support layer 13A and the first transparent electrode layer 12A can be suppressed, and the pattern drawn by the non-driven regions 21 can be made clearer.

[0049] 5, the groove 120 has a groove bend 120GB. The groove bend 120GB is a portion of the groove 120 where the first groove portion GB1 and the second groove portion GB2 are folded back at a bending point GB3. The groove bend 120GB may include a portion where the width of the groove bend 120GB, i.e., the width of the inter-groove region, is 1 mm or more.

[0050] The width of the inter-groove region is defined as follows: When the first groove portion GB1 and the second groove portion GB2 are linear, as in the example shown in Figure 5, a first imaginary line is defined along the first groove portion GB1, and a second imaginary line is defined along the second groove portion GB2. The width of the inter-groove region is the distance between the first imaginary line and the second imaginary line in a direction perpendicular to the bisector that bisects the apex angle of the triangle formed by the first imaginary line and the second imaginary line.

[0051] In contrast, when at least one of the first groove portion GB1 and the second groove portion GB2 has a curved shape, the distance between the first groove portion GB1 and the second groove portion GB2 on a straight line extending in the normal direction of the curved groove portion is the width of the inter-groove region.

[0052] In the groove bend portion 120GB, similar to the narrow portion 30A, the peel strength between the inter-groove region and the second transparent electrode layer 12B may be 0.01 N or more. When the peel strength between the inter-groove region and the second transparent electrode layer 12B is 0.01 N or more, it is possible to suppress peeling that occurs in the portion of the light control sheet 10 that includes the inter-groove region sandwiched by the groove bend portion 120GB.

[0053] The inter-groove region may include a portion where the width of the inter-groove region is 2 mm or more. In this portion, the peel strength per unit length in the width direction of the inter-groove region between the inter-groove region and the second transparent electrode layer 12B may be 0.1 N / 10 mm. Peeling between the inter-groove region and the second transparent electrode layer 12B is suppressed in at least a portion of the portion of the light-controlling sheet 10 that includes the inter-groove region. This allows the optical properties of at least a portion of the portion of the light-controlling sheet 10 that includes the inter-groove region to change depending on whether or not a voltage is applied between the transparent electrode layers 12A and 12B, thereby improving the design of the light-controlling sheet 10.

[0054] On the other hand, the first transparent electrode layer 12A includes a conductive region in addition to the grooves 120 and the inter-groove regions. The conductive region is a region wider than the inter-groove regions. That is, the conductive region is a region that does not include a portion having a width smaller than the width of the inter-groove regions. In the example shown in FIG. 5, the conductive region is the portion of the first transparent electrode layer 12A that is included in the first driving region 20A. The peel strength between the conductive region and the second transparent electrode layer 12B may be 0.38 N / 25 mm or more.

[0055] Because the peel strength between the conductive region and the second transparent electrode layer 12B is 0.38 N / 25 mm, peeling from the second transparent electrode layer 12B is suppressed even in the groove regions, which are narrower than the conductive region. This suppresses poor conductivity due to peeling in the light-controlling sheet, thereby improving the design of the light-controlling sheet.

[0056] FIG. 6 shows an enlarged view of an area including the first connection area 24A and part of the non-drive area 21 in the light controlling sheet 10. As shown in Fig. 6, the first connection region 24A includes a first terminal 50A that applies a voltage to the first transparent electrode layer 12A. The first connection region 24A is bordered by a portion of the first transparent electrode layer 12A that is exposed from the light-switching layer 11. Like the first connection region 24A, the second connection region 24B also includes a second terminal 50B that applies a voltage to the second transparent electrode layer (see Fig. 2). Like the first connection region 24A, the second connection region 24B is bordered by a portion of the second transparent electrode layer 12B that is exposed from the light-switching layer 11.

[0057] The first line SL1 is a line that extends along the first direction in which the first connection region 24A and the second connection region 24B are aligned and passes through the first connection region 24A. The second line SL2 is a line that passes through the groove in the first direction. The shortest distance D between the first line SL1 and the second line SL2 may be 5 mm or more and 50 mm or less.

[0058] The shortest distance D between the first line SL1 passing through the first connection region and the second line SL2 passing through the groove 120 is 5 mm or more. Therefore, even if the floating electrode element 31 is disposed near the first connection region 24A where the shortest distance D is 50 mm or less, an increase in the resistance value in the portion of the driving electrode element 30 located between the first connection region 24A and the floating electrode element 31 is suppressed. This prevents a decrease in the effective voltage applied to the portion of the driving electrode element 30 that is farther from the first connection region 24A than the floating electrode element 31. This makes it possible to change the optical properties of the entire light controlling sheet 10 depending on whether or not a voltage is applied between the transparent electrode layers 12A and 12B, thereby improving the design of the light controlling sheet 10.

[0059] In the first transparent electrode layer 12A, a region adjacent to the first connection region 24A is a unit region. The unit region extends along a first direction and is separated from the first connection region 24A by a first straight line SL1 passing through the first connection region 24A. The length of the unit region in the first direction is 100 mm, and the length of the unit region in a second direction perpendicular to the first direction is 100 mm. In the unit region, the percentage {100×A2 / (A1+A2)} of the area of ​​the floating electrode element 31 to the sum (A1+A2) of the area (A1) of the drive electrode element 30 and the area (A2) of the floating electrode element 31 may be 30% or more. This can enhance the effectiveness of the shortest distance D being 5 mm or more between the first straight line SL1 passing through the first connection region 24A and the second straight line SL2 passing through the groove 120.

[0060] [Light control sheet manufacturing method] An example of a method for manufacturing the light controlling sheet 10 will be described with reference to FIG. First, a first film 51A and a second film 51B are prepared. The first film 51A includes a first transparent electrode layer 12A and a first transparent support layer 13A. The second film 51B includes a second transparent electrode layer 12B and a second transparent support layer 13B.

[0061] Of these, grooves 120 are formed in first film 51A using a cutting plotter on the surface of first transparent electrode layer 12A that contacts first transparent support layer 13A. A control device connected to the cutting plotter operates the cutting plotter according to a design input into the control device in advance, thereby forming grooves 120 that penetrate first transparent electrode layer 12A and extend partway through the thickness direction of first transparent support layer 13A.

[0062] It should be noted that the grooves 120 may be formed using a device other than a cutting plotter. For example, the grooves 120 may be formed in the first transparent electrode layer 12A using a blade other than a cutting plotter or a laser cutting device. The laser cutting device may be, for example, a laser equipped with a CO2 laser. When a laser cutting device is used, the portions of the first transparent electrode layer 12A and the first transparent support layer 13A irradiated with laser light are directly destroyed, thereby forming the grooves 120.

[0063] Next, a liquid containing spacers 15, whose main material is divinylbenzene or the like, and a dispersion medium for dispersing the spacers 15 is prepared. The liquid is then applied to the first transparent electrode layer 12A of the first film 51A and the second transparent electrode layer 12B of the second film 51B. In this way, the spacers 15 are dispersed on the first transparent electrode layer 12A and the second transparent electrode layer 12B. Furthermore, the films 51A and 51B on which the spacers 15 have been dispersed are heated, thereby removing the dispersion medium from the liquid. Note that the spacers 15 may be dispersed only on either the first film 51A or the second film 51B.

[0064] Then, a light-controlling material containing a liquid crystal composition and a polymerizable composition for forming a transparent polymer layer is applied to the first transparent electrode layer 12A and the second transparent electrode layer 12B. Furthermore, the films 51A and 51B are irradiated with ultraviolet light in a nitrogen atmosphere, thereby forming light-controlling layers 11A and 11B. Next, the second film 51B is laminated on the first film 51A so that the light-controlling layers 11A and 11B are in contact with each other. While applying a predetermined amount of pressure to the laminate, the second film 51B is bonded to the first film 51A. This fills the grooves 120 with at least a portion of the liquid crystal composition. The grooves 120 may be filled with both a portion of the transparent polymer layer and a portion of the liquid crystal composition.

[0065] The light-controlling sheet 10 may be manufactured by either a roll-to-roll method or a sheet-fed method. In the roll-to-roll method, the film is pulled out from an upstream roll and various processes are performed on it while it is being transported, and then the processed film is wound up on a downstream roll. In the sheet-fed method, various processes are performed on film that has been cut to a predetermined size. In either case, the process of forming the grooves 120 in the first film 51A is performed before the process of bonding the second film 51B to the first film 51A with the light-controlling layer 11 interposed therebetween.

[0066] Next, a corner of the second surface 11R of the light-controlling sheet 10 having a predetermined size is cut to peel off a portion of the second transparent support layer 13B and a portion of the second transparent electrode layer 12B. This exposes a portion of the light-controlling layer 11 to the outside. Furthermore, the exposed portion of the light-controlling layer 11 is removed to expose a portion of the first transparent electrode layer 12A, thereby forming a first connection region 24A. Similarly, a second connection region 24B is formed at a corner of the first surface 11F. Then, a first terminal portion 50A is formed in the first connection region 24A, and a second terminal portion 50B is formed in the second connection region 24B. Next, external wiring 25 is connected to each terminal portion 50A, 50B. Furthermore, the connection region 24 is sealed with epoxy resin or the like. The step of bonding the protective layer 44 to the first transparent support layer 13A may be performed after bonding the pair of films 51A and 51B together, or may be performed before bonding the films 51A and 51B together.

[0067] In this way, the grooves 120 are formed by cutting the first transparent electrode layer 12A and the first transparent support layer 13A. Therefore, compared to a manufacturing method that includes steps such as forming a resist mask required for patterning, etching, removing the resist mask, and cleaning, the grooves 120 can be formed more simply.

[0068] [Effect] The operation of this embodiment will be described with reference to Figures 1 and 8. Figure 8 schematically shows the degree of transparency of the light controlling sheet 10 when the light controlling sheet 10 is not driven, that is, when no voltage signal is applied to the first transparent electrode layer 12A and the second transparent electrode layer 12B.

[0069] 8, when the light controlling sheet 10 is not driven, both the driving region 20 and the non-driving region 21 are opaque. Therefore, the entire surface of the light controlling sheet 10 appears, for example, whitish and cloudy, and images such as letters and pictures formed in the non-driving region 21 cannot be seen.

[0070] Furthermore, because the grooves 120 have a depth that penetrates the first transparent electrode layer 12A but does not penetrate the first transparent support layer 13A, the grooves 120 are inconspicuous whether the light controlling sheet 10 is viewed from the first surface 11F or the second surface 11R. In addition, by filling the grooves 120 with at least a liquid crystal composition of the light controlling material, the grooves 120 can be made even less visible when the light controlling sheet 10 is not driven. This improves the aesthetic appearance of the light controlling sheet 10 when no pattern is displayed.

[0071] 1, when the light controlling sheet 10 is driven, the driving region 20 is transparent, while the non-driving region 21 is opaque. Therefore, only the non-driving region 21 appears, for example, whitish and cloudy, and images of patterns such as letters and pictures formed in the non-driving region 21 are visible. At this time, a voltage signal is applied to the second driving region 20B surrounded by the non-driving region 21 and the first driving region 20A outside the non-driving region 21, causing the driving regions 20A and 20B to appear transparent.

[0072] As described above, according to the light-adjusting sheet 10 of this embodiment, regions with different diffuse transmittances are formed within the surface of the light-adjusting sheet 10, and the difference in diffuse transmittance between these regions only appears when the light-adjusting sheet 10 is driven. Therefore, when the light-adjusting sheet 10 is driven, images such as letters and patterns formed in the non-driven regions 21 are visible. This makes it possible to improve the design of the light-adjusting sheet 10.

[0073] The image displayed by the light-controlling sheet 10 can also be used to decorate the space in which the light-controlling sheet 10 is installed. Furthermore, by switching between driving and non-driving the light-controlling sheet 10, the appearance of the image can be switched on and off, allowing the decorative state of the space to be dynamically changed.

[0074] As described above, according to the first embodiment, the following effects can be obtained. (1-1) Since the peel strength between the inter-groove region and the second transparent electrode layer 12B is 0.01 N or more, peeling of the light controlling sheet 10 in the portion including the inter-groove region can be suppressed.

[0075] (1-2) Since the peel strength per unit length between the narrowed portion 30A and the second transparent electrode layer 12B is 0.1 N / 10 mm or more, when the light-controlling sheet 10 has a narrowed portion 30A with a width of 2 mm or more, peeling is suppressed in the portion including the narrowed portion 30A.

[0076] (1-3) It is possible to prevent peeling from occurring in the portion of the light controlling sheet 10 that includes the inter-groove region sandwiched between the groove bends 120GB. (1-4) Peeling between the inter-groove region and the second transparent electrode layer 12B is suppressed in at least a part of the portion including the inter-groove region defined by the groove bend portion 120GB.

[0077] (1-5) Since the peel strength between the conductive region and the second transparent electrode layer 12B is 0.38 N / 25 mm, peeling between the conductive region and the second transparent electrode layer 12B is suppressed even in the groove region, which is narrower than the conductive region.

[0078] (1-6) Even when the floating electrode element 31 is disposed near the first connection region 24A, an increase in the resistance value is suppressed in the portion of the driving electrode element 30 located between the first connection region 24A and the floating electrode element 31. This prevents a decrease in the effective voltage applied to the portion of the driving electrode element 30 that is farther from the first connection region 24A than the floating electrode element 31.

[0079] (1-7) Since the width of the narrowed portion 30A provided in the driving electrode element 30 is 1 mm or more, peeling of the first transparent electrode layer 12A or the first transparent support layer 13A is unlikely to occur during the process of forming the groove 120 or after the groove 120 is formed.

[0080] (1-8) Because the width of the narrowed portion 30A is 1 mm or more, poor conduction due to increased resistance in the narrowed portion 30A is suppressed, and the diffuse transmittance of the first driving region 20A and the second driving region 20B can be appropriately controlled. Therefore, patterns can be clearly displayed on the light controlling sheet 10, improving the design of the light controlling sheet 10.

[0081] (1-9) The first driving region 20A and the second driving region 20B surrounded by the non-driving region 21 are electrically connected by the conductive portion 26 including the narrowed portion 30A, so that the changes in the diffuse transmittance of the driving regions 20A and 20B can be synchronized depending on the state of application of the voltage signal to the driving electrode element 30.

[0082] (1-10) The angle of the bent portion 102 in the non-driving region 21 or the angle between the tangents 105, 106 of the bent portion 102 is 10 degrees or more. Therefore, peeling of the first transparent electrode layer 12A or the first transparent support layer 13A is unlikely to occur in the process of forming the groove 120, which makes it easy to form the driving electrode elements 30 and the floating electrode elements 31 into the desired shapes. This allows patterns to be clearly displayed on the light control sheet 10.

[0083] (1-11) The grooves 120 that separate the driving region 20 and the non-driving region 21 have a depth that penetrates the first transparent electrode layer 12A but does not penetrate the first transparent electrode layer 12A. This reduces light scattering by the grooves 120 on the surface of the first transparent support layer 13A opposite the support surface 130. As a result, the grooves 120 can be made less noticeable when the light controlling sheet 10 is viewed from the first transparent electrode layer 12A side, at least from a position facing the surface opposite the support surface 130. This improves the aesthetic appearance of the light controlling sheet 10.

[0084] [Second embodiment] A second embodiment of the light controlling sheet will be described with reference to Fig. 9. In the second embodiment, the layered structure of the light controlling sheet 10 differs from that of the first embodiment of the light controlling sheet 10. Hereinafter, the same parts as those in the first embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted.

[0085] FIG. 9 shows the cross-sectional structure of the light controlling sheet 10. As shown in FIG. 9 , the driving electrode elements 30 and floating electrode elements 31 included in the first transparent electrode layer 12A are separated by grooves 120. The grooves 120 extend along the thickness direction of the first transparent electrode layer 12A. In this embodiment, the grooves 120 penetrate the first transparent electrode layer 12A and the first transparent support layer 13A. The grooves 120 have openings 122 located on the surface of the first transparent electrode layer 12A that contacts the light control layer 11, and openings 124 located on the surface of the first transparent support layer 13A opposite to the surface that contacts the first transparent electrode layer 12A. The driving electrode elements 30 and the floating electrode elements 31 are insulated from each other by being separated by the grooves 120.

[0086] The light controlling sheet 10 further includes an adhesive layer 45 and a protective layer 44. A portion of the adhesive layer 45 is filled in the grooves 120. The adhesive layer 45 may be formed from a light-transmitting material that can bond the protective layer 44 and the first transparent support layer 13A together. For example, the adhesive layer 45 is an optical clear adhesive film that bonds the first transparent support layer 13A and the protective layer 44 together.

[0087] In the light controlling sheet 10 of this embodiment, as in the light controlling sheet 10 of the first embodiment, the peel strength between the narrowing portion 30A and the second transparent electrode layer 12B may be 0.01 N or more. Furthermore, when the width of the narrowing portion 30A is 2 mm or more, the peel strength between the narrowing portion 30A and the second transparent electrode layer 12B per unit length in the width direction of the narrowing portion 30A may be 0.1 N / 10 mm. Furthermore, the peel strength between the inter-groove region of the groove bend portion 120GB and the second transparent electrode layer 12B may be 0.01 N or more. Furthermore, the inter-groove region may include a portion where the width of the inter-groove region is 2 mm or more. In this portion, the peel strength between the inter-groove region and the second transparent electrode layer 12B per unit length in the width direction of the inter-groove region may be 0.1 N / 10 mm.

[0088] [Light control sheet manufacturing method] An example of a method for manufacturing the light controlling sheet 10 will be described. As in the first embodiment, a first film 51A including a first transparent electrode layer 12A and a first transparent support layer 13A, and a second film 51B including a second transparent electrode layer 12B and a second transparent support layer 13B are prepared. Furthermore, spacers 15 are dispersed on each of the films 51A and 51B, and then a light-controlling material containing a polymerizable composition and a liquid crystal composition is applied. After forming light-controlling layers 11A and 11B from the light-controlling material, the pair of films 51A and 51B are laminated together, and the second film 51B is bonded to the first film 51A while applying a predetermined amount of pressure to the pair of films 51A and 51B.

[0089] In the laminate thus formed, an incision is made from surface 131 (see FIG. 9) opposite support surface 130 of first transparent support layer 13A to light-control layer 11. This forms grooves 120 that penetrate first transparent support layer 13A and first transparent electrode layer 12A. Note that grooves 120 can be formed by a method similar to that of the first embodiment. Thereafter, an adhesive layer 45 and a protective layer 44 are overlaid on surface 131 of first transparent support layer 13A.

[0090] In this way, when grooves 120 are formed in the light-controlling sheet 10 after forming the light-controlling sheet 10 including the first transparent electrode layer 12A, the second transparent electrode layer 12B, the light-controlling layer 11, and the first transparent support layer 13A, the light-controlling sheet 10 may satisfy the following. That is, the light-controlling sheet 10 may be a light-controlling sheet for forming inter-groove regions having a width of 2 mm or more, and the peel strength of the light-controlling sheet 10 may be 0.38 N / 25 mm or more. The inter-groove regions may be narrowed portions 30A, as described above, or may be regions surrounded by groove bends 120GB.

[0091] In this case, even if the first transparent electrode layer 12A of the light controlling sheet 10 is patterned to have inter-groove regions, peeling is prevented from occurring in the portion of the light controlling sheet 10 that includes the inter-groove regions. This makes it possible to prevent poor conductivity caused by peeling, thereby improving the design of the light controlling sheet 10.

[0092] The grooves 120 do not have to be formed after forming a laminate in which the light-controlling layer 11 is sandwiched between the films 51A and 51B. For example, the grooves 120 may be formed between any of the following steps in the process of forming the laminate. That is, the grooves 120 may be formed before the step of spraying the spacers 15 on the first film 51A, between the step of spraying the spacers 15 and the step of applying the light-controlling material, between the step of forming the light-controlling layer 11A and the step of laminating the films 51A and 51B, etc.

[0093] According to the second embodiment, in addition to the above-mentioned effects (1-1) to (1-10), the following effects can be obtained. (2-1) Even if the first transparent electrode layer 12A of the light controlling sheet 10 is patterned to have inter-groove regions, peeling is prevented from occurring in the portions of the light controlling sheet 10 that include the inter-groove regions.

[0094] (2-2) Because the grooves 120 have a depth that penetrates the first transparent support layer 13A and the second transparent support layer, the grooves 120 can be formed after laminating the first transparent support layer 13A, the first transparent electrode layer 12A, the light control layer 11, the second transparent electrode layer 12B, and the second transparent support layer 13B. It is also possible to form the grooves 120 between the steps of forming each layer. This allows for greater flexibility in the manufacturing process of the light control sheet 10.

[0095] [Example of change] The above-described embodiments can be modified as follows: The following modifications may be combined and implemented.

[0096] Number of Undriven Regions In each embodiment, the second driving region 20B surrounded by a linear non-driving region 21 and the first driving region 20A located outside the non-driving region 21 are connected by a conductive portion 26 including a narrowing portion 30A, but the number of non-driving regions 21 in the light control sheet 10 is not limited to one.

[0097] FIG. 10 shows an example of a light controlling sheet 10 in which a plurality of non-drive areas 21 are provided. As shown in Fig. 10, the non-drive area 21 includes a floating area 22 and a boundary area 23. The boundary area 23 has a frame shape. The boundary area 23 defines the floating area 22, which is a closed area. In the example shown in Fig. 10, the boundary area 23 included in the light controlling sheet 10 surrounds the floating area 22, which has a star shape. In other words, the floating area 22 is defined by the boundary area 23, which has a hollow star shape.

[0098] The light controlling sheet 10 has two different non-drive regions 21 that are independent of each other. Between the two non-drive regions 21 is a narrowed portion 30A sandwiched between two different grooves 120. The narrowed portion 30A is a portion of the first transparent electrode layer 12A whose width is narrowed by two different grooves 120 being close to each other. In the light controlling sheet 10, the portion including the narrowed portion 30A is a conductive portion 27, and the conductive portion 27 provides electrical conductivity to the drive regions 20 located around the conductive portion 27.

[0099] The width L3 of the narrowed portion 30A may be 1 mm or more. In other words, the distance between two different non-driving regions 21 may be 1 mm or more. When the width L3 of the narrowed portion 30A is 1 mm or more, a decrease in conductivity in the narrowed portion 30A is suppressed, and this makes it easier to equalize the diffuse transmittance in the driving regions 20 connected via the narrowed portion 30A. Note that although the light controlling sheet 10 shown in FIG. 10 has two non-driving regions 21, the light controlling sheet 10 may have three or more non-driving regions 21.

[0100] In each embodiment, the groove 120 has a closed frame shape surrounding the floating electrode element 31. Alternatively, the groove 120 does not have to have a closed frame shape surrounding the floating electrode element 31 as long as it extends along the support surface 130 of the first transparent support layer 13A and satisfies the following conditions: For example, the groove 120 may extend from a starting point located at a first end of one of the four sides of the rectangular light-controlling sheet 10, pass around the periphery of the floating region 22, and end at a second end. The second end may be located on the same side as the first end of the four sides of the light-controlling sheet 10, or on a different side. Even if the light-controlling sheet 10 is not rectangular, the starting and ending points of the groove 120 may be located at the ends of the light-controlling sheet 10, and the groove 120 may pass around the periphery of the floating region 22 during its extension.

[0101] [Light control sheet type] The light controlling sheet 10 may be of a reverse type. In the reverse type light controlling sheet 10, when no voltage signal is applied between the transparent electrode layers 12A and 12B, the incident light is transmitted, thereby reducing the diffuse transmittance, and when a voltage signal is applied, the incident light is scattered, thereby increasing the diffuse transmittance.

[0102] FIG. 11 shows an example of a reverse-type light controlling sheet 10. 11, the reverse-type light-controlling sheet 10 includes a functional layer 111 including a transparent polymer layer and a liquid crystal composition, a first alignment layer 112, and a second alignment layer 113. The functional layer 111, the first alignment layer 112, and the second alignment layer 113 constitute the light-controlling layer 11. The first alignment layer 112 is located between the functional layer 111 and the first transparent electrode layer 12A and is in contact with these layers. The second alignment layer 113 is located between the functional layer 111 and the second transparent electrode layer 12B and is in contact with these layers.

[0103] Each of the first alignment layer 112 and the second alignment layer 113 is, for example, a vertical alignment film. The vertical alignment film aligns the long axis direction of the liquid crystal molecules along the thickness direction of the light control layer 11. In this way, the first alignment layer 112 and the second alignment layer 113 regulate the alignment of the multiple liquid crystal molecules contained in the light control layer 11.

[0104] The material for forming each of the first alignment layer 112 and the second alignment layer 113 is an organic compound, an inorganic compound, or a mixture thereof. Examples of organic compounds include polyimide, polyamide, polyvinyl alcohol, and cyanide compounds. Examples of inorganic compounds include silicon oxide and zirconium oxide. The material for forming the first alignment layer 112 and the second alignment layer 113 may be silicone. Silicone is a compound having an inorganic portion and an organic portion.

[0105] The grooves 120 have openings 122 on the surface of the first alignment layer 112 that contacts the light-controlling layer 11, and penetrate the first alignment layer 112 and the first transparent electrode layer 12A but do not penetrate the first transparent support layer 13A. In other words, the depth of the grooves 120 is smaller than the sum of the thicknesses of the first alignment layer 112, the first transparent electrode layer 12A, and the first transparent support layer 13A. The grooves 120 are filled with a portion of the light-controlling layer 11. The grooves 120 may also penetrate the first transparent support layer 13A, similar to the grooves 120 provided in the light-controlling sheet 10 of the second embodiment.

[0106] When the light-controlling sheet 10 includes the first alignment layer 112 and the second alignment layer 113, in the driving region 20, when no voltage signal is applied to the first transparent electrode layer 12A and the second transparent electrode layer 12B, the long axis direction of the liquid crystal molecules is aligned with the thickness direction of the light-controlling layer 11. Therefore, the driving region 20 is transparent. On the other hand, when a voltage signal is applied to the first transparent electrode layer 12A and the second transparent electrode layer 12B in the driving region 20, the long axis direction of the liquid crystal molecules intersects with the thickness direction of the light-controlling layer 11. Therefore, the driving region 20 appears cloudy, in other words, opaque. When the light-controlling sheet 10 includes the first alignment layer 112 and the second alignment layer 113, in the floating region 22 and the boundary region 23, the long axis direction of the liquid crystal molecules is always aligned with the thickness direction of the light-controlling layer 11, and therefore the non-driving region 21 is always transparent.

[0107] Therefore, when the light-adjusting sheet 10 is not driven, all of the driving regions 20 are transparent, and images such as letters and patterns formed in the non-driving regions 21 are not visible. On the other hand, when the light-adjusting sheet 10 is driven, the driving regions 20 become opaque, while the non-driving regions 21 are transparent, so that images such as letters and patterns formed in the non-driving regions 21 are visible.

[0108] In this way, even when the light-controlling sheet 10 includes the first alignment layer 112 and the second alignment layer 113, regions with different diffuse transmittances are formed within the plane of the light-controlling sheet 10, and the difference in diffuse transmittance between these regions only appears when the light-controlling sheet 10 is in operation. This makes it possible to improve the design of the light-controlling sheet 10.

[0109] 11, the grooves 120 penetrate the first alignment layer 112, but the first alignment layer 112 may be formed after the grooves 120 are formed in a laminate consisting of the first transparent electrode layer 12A and the first transparent support layer 13A. In this case, the first alignment layer 112 is formed so as to follow the bottom and side surfaces of the grooves 120. Even in this case, the grooves 120 can be made less noticeable when the light controlling sheet 10 is viewed from a viewpoint opposite the first surface 11F or the second surface 11R of the light controlling sheet.

[0110] Groove Position As shown in FIG. 10 , when the light-adjusting sheet 10 has multiple grooves 120, the grooves 120 may be located at the same depth in the stacking direction of the layers constituting the light-adjusting sheet 10, i.e., in the thickness direction of the light-adjusting sheet 10. Alternatively, the multiple grooves 120 may be located at different depths in the stacking direction. Examples are listed in FIGS. 12 to 14 , and in each of these examples, the grooves 120 can be formed using the methods described in the above-mentioned embodiments. While the following describes a normal-type light-adjusting sheet 10, the following examples may also be applied to a reverse-type light-adjusting sheet 10. Furthermore, in the examples shown in FIGS. 12 to 14 , the grooves 120 are not filled with a light-adjusting material, but at least a portion of the grooves 120 may be filled with a light-adjusting material.

[0111] 12, the first groove 120A penetrates the first transparent support layer 13A and the first transparent electrode layer 12A. In contrast, the second groove 120B penetrates only the second transparent electrode layer 12B. The second groove 120B may be formed in the second transparent electrode layer 12B via the second transparent support layer 13B. In this case, the second groove 120B may be formed using, for example, a laser cutting device.

[0112] 13, the multiple grooves 120 are formed by cutting from the first transparent support layer 13A through at least the first transparent support layer 13A and the first transparent electrode layer 12A. The first grooves 120A penetrate the first transparent support layer 13A and the first transparent electrode layer 12A. The second grooves 120B penetrate the first transparent support layer 13A, the first transparent electrode layer 12A, the light control layer 11, and the second transparent electrode layer 12B.

[0113] 14, the first groove 120A penetrates through the first transparent support layer 13A and the first transparent electrode layer 12A. The second groove 120B penetrates through the second transparent support layer 13B and the second transparent electrode layer 12B.

[0114] 12 to 14, in a plan view facing the first surface 11F of the light controlling sheet 10, the second grooves 120B do not overlap the first grooves 120A. The region where each groove 120A, 120B is located is the boundary region 23. Furthermore, if the first grooves 120A and the second grooves 120B are formed close to each other at the same position in the stacking direction of the light controlling sheet 10, the strength of the region between the grooves 120A, 120B and its vicinity is likely to decrease. In this regard, as described above, by forming the grooves 120A, 120B at different positions in the stacking direction, it is possible to prevent a decrease in the strength of the light controlling sheet 10 even if the grooves 120A, 120B are formed close to each other.

[0115] [Floating electrode element] In each embodiment, a voltage signal is applied to the driving electrode element 30, which is the first electrode element, and no voltage signal is applied to the floating electrode element 31, which is the second electrode element. Alternatively, voltage signals may be applied separately to the first electrode element and the second electrode element. In this case, wiring for applying a voltage signal to the second electrode element is connected to the end of the second electrode element. The terminal portion connected to the first electrode element and the terminal portion connected to the second electrode element are separate terminal portions for each voltage signal.

[0116] As described above, when the second electrode elements are located at the end of the light-controlling sheet 10, it is easy to connect wiring to the second electrode elements. For example, the first region where the first electrode elements are located can be switched between transparent and opaque by switching the state of application of a voltage signal to the first electrode elements. The second region where the second electrode elements are located can be switched between transparent and opaque, independently of the first region, by switching the state of application of a voltage signal to the second electrode elements.

[0117] In this case, the state of the light controlling sheet 10 can be switched between the following four states: a first state in which both the first and second regions are opaque; a second state in which the first region is opaque and the second region is transparent; a third state in which the first region is transparent and the second region is opaque; and a fourth state in which both the first and second regions are opaque. This allows the decorative state of the space created by the light controlling sheet 10 to be changed in a more diverse manner, further improving the design of the light controlling sheet 10.

[0118] The diffuse transmittance in at least one of the first and second regions may be controlled to a diffuse transmittance between transparent and opaque. In a light-controlling sheet 10 including a light-controlling layer 11 containing a liquid crystal composition, when the potential difference between the first transparent electrode layer 12A and the second transparent electrode layer 12B is within a predetermined range, the diffuse transmittance of the light-controlling sheet 10 gradually changes as the potential difference changes. Therefore, by controlling the potential difference between the first transparent electrode layer 12A and the second transparent electrode layer 12B in the first or second region to a value between the potential difference at which each region becomes transparent and the potential difference at which each region becomes opaque, each region can be controlled to be translucent, i.e., have a diffuse transmittance between transparent and opaque.

[0119] Specifically, for example, the first region can be switched between transparent and opaque by switching the state of application of a voltage signal to the first electrode element, while the second region can be switched between translucent and opaque by switching the state of application of a voltage signal to the second electrode element. For example, when the first region is transparent, the second region is controlled to be translucent. This allows switching between a state in which both the first and second regions are opaque and a state in which the first region is opaque and the second region is translucent. This also improves the design of the light controlling sheet 10.

[0120] [Number of stenoses] In the first embodiment, the driving regions 20A and 20B defined by the non-driving regions 21 are electrically connected to each other through one narrowing portion 30A. Alternatively, the driving regions 20A and 20B defined by the non-driving regions 21 may be electrically connected to each other through multiple narrowing portions 30A. In other words, the light controlling sheet 10 may include multiple conductive portions 26 sandwiched between the non-driving regions 21. Each narrowing portion 30A has the same configuration as the narrowing portion 30A in the first embodiment. For example, as shown in FIG. 15 , the driving regions 20A and 20B may be electrically connected to each other through two narrowing portions 30A. The width of each narrowing portion 30A may be, for example, 1 mm or more. In this case, the light controlling sheet 10 includes two non-driving regions 21, and each non-driving region 21 includes a first end 21A and a second end 21B. In the example shown in FIG. 15, one narrowed portion 30A is located between the second end 21B of the first non-driving region 21 and the first end 21A of the second non-driving region 21.

[0121] [Width of the narrowed part] The width L1 of the narrowing portion 30A may be less than 1 mm. Even in this case, by increasing the voltage applied between the transparent electrode layers 12A and 12B compared to when the width L1 of the narrowing portion 30A is 1 mm or more, it is possible to reduce the difference in diffuse transmittance between the first driving region 20A and the second driving region 20B connected by the conductive portion 26 including the narrowing portion 30A. Alternatively, by reducing the area of ​​the second driving region 20B connected to the conductive portion 26 including the narrowing portion 30A compared to when the width of the narrowing portion 30A is 1 mm or more, it is possible to reduce the difference in diffuse transmittance between the first driving region 20A and the second driving region 20B.

[0122] [Non-Driven Area] The light-adjusting sheet 10 may include the first electrode element and the groove 120C but may not include the second electrode element. The groove 120C has a width wide enough that the shape of the groove 120C can be recognized by an observer when viewing the light-adjusting sheet 10 from a viewpoint opposite the first surface 11F of the light-adjusting sheet 10. In the example shown in FIG. 15, the light-adjusting sheet 10 includes the first electrode element and the groove 120C but does not include the second electrode element insulated from the first electrode element by the groove 120C. The diffuse transmittance of the portion of the light-adjusting sheet 10 including the first electrode element changes depending on the state of application of a voltage signal. The groove 120C may be a recess that does not penetrate the light-adjusting sheet 10.

[0123] In the example shown in Figure 16, the grooves 120C have a C-shape. In the light controlling sheet 10, the areas where the grooves 120C are formed do not include electrode elements. The grooves 120C are filled with at least one of a transparent polymer layer and a liquid crystal composition. Alternatively, the grooves 120C may be filled with a substance other than the transparent polymer layer and the liquid crystal composition, or the grooves 120C may be voids that are not filled with a substance.

[0124] Note that when the grooves 120C are filled with at least one of a liquid crystal composition and a transparent polymer layer, the grooves 120C have scattering properties. In this case, when the light-adjusting sheet 10 is not driven, both the driving region 20 where the grooves 120C are not formed and the grooves 120C are opaque. On the other hand, when the light-adjusting sheet 10 is driven, the driving region 20 is transparent, while the grooves 120C remain opaque. Therefore, only the grooves 120C appear whitish, in other words, cloudy, which allows the image of the pattern, such as letters or pictures, formed by the grooves 120C to be seen. In the example shown in FIG. 16, the letter "C" is visible.

[0125] In contrast, when the grooves 120C are filled with a substance other than the transparent polymer and liquid crystal composition that has lower scattering properties than the liquid crystal composition and the transparent polymer layer, or when the grooves 120C are voids, the grooves 120 are transparent. In this case, when the light controlling sheet 10 is driven, the driving regions 20 in which the grooves 120C are not formed and the grooves 120C are both transparent. On the other hand, when the light controlling sheet 10 is not driven, the driving regions 20 are opaque, while the grooves 120C remain transparent. Therefore, graphic images such as letters and patterns formed by the grooves 120C are visible.

[0126] Furthermore, when the light controlling sheet 10 has multiple grooves 120C, the width L30 of the narrowed portion 30A defined by the multiple grooves 120C may be 1 mm or more. Furthermore, the width L10 of the narrowed portion 30A formed by one groove 120C may be 1 mm or more. In the first transparent electrode layer 12A, the region surrounded by the grooves 120C is the second drive electrode element, and the region located outside the grooves 120C and connected to the second drive electrode element is the first drive electrode element.

[0127] [Test example] A test example will be described with reference to FIGS. [Resistance value] [Test Example 1-1] As shown in FIG. 17, a rectangular resistance measurement area 143 was formed on a substrate having a transparent electrode layer 140 and a transparent support layer 141. The resistance measurement area 143 was 50 mm × 25 mm in size. Two resistance measurement areas 143 were connected via a narrowed portion 144 (conductive portion) having a width L4 of 50 mm and a length L5 of 100 mm, thereby producing a measurement sample. The measurement sample was produced so that the long sides of each resistance measurement area 143 were connected by the narrowed portion 144. A tester was then connected to the two resistance measurement areas 143 to measure the resistance.

[0128] [Test Example 1-2] A measurement sample for Test Example 1-2 was prepared in the same manner as in Test Example 1-1, except that the width L4 of the narrowed portion 144 in Test Example 1-1 was set to 20 mm.

[0129] [Test Example 1-3] A measurement sample for Test Example 1-3 was prepared in the same manner as in Test Example 1-1, except that the width L4 of the narrowed portion 144 in Test Example 1-1 was set to 10 mm.

[0130] [Test Example 1-4] A measurement sample for Test Example 1-4 was prepared in the same manner as in Test Example 1-1, except that the width L4 of the narrowed portion 144 in Test Example 1-1 was set to 5 mm.

[0131] [Test Example 1-5] A measurement sample for Test Example 1-5 was prepared in the same manner as in Test Example 1-1, except that the width L4 of the narrowed portion 144 in Test Example 1-1 was set to 2 mm.

[0132] [Test Example 1-6] A measurement sample for Test Example 1-6 was prepared in the same manner as in Test Example 1-1, except that the width L4 of the narrowed portion 144 in Test Example 1-1 was set to 1 mm.

[0133] [Test Example 1-7] A measurement sample for Test Example 1-7 was prepared in the same manner as in Test Example 1-1, except that the width L4 of the narrowed portion 144 in Test Example 1-1 was set to 0.5 mm.

[0134] [Measurement method and evaluation results] The resistance value of each measurement sample was measured using a digital multimeter (TY530, manufactured by Yokogawa Measurement Corporation).

[0135] 18, the resistance values ​​(Ω) of the measurement samples of Test Examples 1-1 to 1-6 were 494Ω, 719Ω, 1,225Ω, 2,259Ω, 5,220Ω, and 10,900Ω, respectively, and it was observed that the resistance value increased as the width L4 of the narrowed portion 144 became smaller. The resistance value of the measurement sample of Test Example 1-7 was 26,800Ω, which was observed to be dramatically higher than that of Tests 1-1 to 1-6.

[0136] [Effective voltage] Next, the effective voltage was measured in a light-control sheet in which a light-control layer was sandwiched between a pair of substrates. [Test Example 1-8] A light-controlling sheet with a layered structure similar to the light-controlling sheet 10 shown in Figure 2 was prepared. Two rectangular characteristic measurement areas measuring 50 mm x 25 mm were secured at separate locations, and these characteristic measurement areas were connected by a conductive section including a constriction. The widths of the conductive section and the constriction section were set to 50 mm, and the length of the constriction section was set to 100 mm.

[0137] Furthermore, two connection areas were formed in each characteristic measurement area using a method similar to the method for forming the connection areas in the light-controlling sheet 10 shown in FIG. 2. That is, for each characteristic measurement area, a notch was made in the corner of one of the surfaces (the second surface), the transparent support layer and transparent electrode layer were peeled off, and the liquid crystal was then removed to form a connection area. Similarly, a notch was made in the corner of the other surface (the first surface), the transparent support layer and transparent electrode layer were peeled off, and the liquid crystal was then removed to form a connection area. External wiring was then connected to these connection areas. This made it possible to control the voltage applied to one characteristic measurement area and to connect an effective voltage measuring device to the other characteristic measurement area.

[0138] [Test Example 1-9] A measurement sample was prepared in the same manner as in Test Example 1-8, except that the width of the narrowed portion was set to 20 mm. [Test Example 1-10] A measurement sample was prepared in the same manner as in Test Example 1-8, except that the width of the narrowed portion was set to 10 mm.

[0139] [Test Example 1-11] A measurement sample was prepared in the same manner as in Test Example 1-8, except that the width of the constricted portion was set to 5 mm. [Test Example 1-12] A measurement sample was prepared in the same manner as in Test Example 1-8, except that the width of the constricted portion was set to 2 mm.

[0140] [Test Example 1-13] A measurement sample was prepared in the same manner as in Test Example 1-8, except that the width of the constricted portion was set to 1 mm. [Test Example 1-14] A measurement sample was prepared in the same manner as in Test Example 1-8, except that the width of the narrowed portion was set to 0.5 mm.

[0141] [Measurement method and evaluation results] A power supply (LP1-RS232, manufactured by Toppan Printing Co., Ltd.) was connected to one of the characteristic measurement areas. A voltage of 80 V with a frequency of 40 Hz and a rectangular waveform was applied using the power supply. The above-mentioned digital multimeter was connected to the other characteristic measurement area, and the effective voltage was measured using the digital multimeter.

[0142] As shown in Figure 19, in Test Examples 1-8 to 1-13, where the width of the conductive portion was 1.0 mm or more, the effective voltage was found to be between 79.7 V and 81.4 V. In Test Examples 1-8 to 1-13, the effective voltage decreased as the width of the constricted portion included in the conductive portion narrowed, but there was no significant change in the effective voltage. In contrast, in Test Example 1-14, where the width of the constricted portion included in the conductive portion was 0.5 mm, the effective voltage was found to be 7.9 V. In other words, when the width of the constricted portion was less than 1 mm, the effective voltage was found to drop significantly. Furthermore, in Test Example 1-14, repeated starting and stopping of voltage application caused poor conductivity.

[0143] [Peel strength] [Test Example 2-1] A first transparent film and a second transparent film were prepared, each including a transparent electrode layer made of indium tin oxide and a transparent support layer made of polyethylene terephthalate to support the transparent electrode layer. Next, a coating liquid containing an acrylic monomer and liquid crystal was prepared. The first transparent film and the second transparent film were placed opposite each other so that the transparent support layer was positioned on the outside of the transparent electrode layer, and the coating liquid was sandwiched between the first transparent film and the second transparent film. Then, ultraviolet light was irradiated onto the coating liquid through the first transparent film and the second transparent film, causing phase separation between the liquid crystal and the transparent resin layer, thereby forming a light-controlling layer. This resulted in the light-controlling sheet of Test Example 2-1.

[0144] [Test Example 2-2] A light-controlling sheet of Test Example 2-2 was obtained in the same manner as in Test Example 2-1, except that the ratio of the mass of the monomer to the mass of the liquid crystal in the coating liquid was made smaller.

[0145] [Test Example 2-3] A light-controlling sheet of Test Example 2-3 was obtained in the same manner as in Test Example 2-2, except that the ratio of the mass of the monomer to the mass of the liquid crystal in the coating liquid was made smaller.

[0146] [Test Example 2-4] A light-controlling sheet of Test Example 2-4 was obtained in the same manner as Test Example 2-1, except that the acrylic monomer contained in the coating liquid in Test Example 2-1 was changed to an acrylic monomer with lower adhesion to each transparent film.

[0147] [Test Example 2-5] A light-controlling sheet of Test Example 2-5 was obtained in the same manner as Test Example 2-3, except that the ratio of the mass of the monomer to the mass of the liquid crystal in the coating liquid was made smaller.

[0148] [Test Example 2-6] A light-control sheet of Test Example 2-6 was obtained in the same manner as in Test Example 2-1, except that the time for irradiating the coating liquid with ultraviolet light was shortened.

[0149] [Test Example 2-7] The light-control sheet of Test Example 2-7 was obtained in the same manner as Test Example 2-5, except that the acrylic monomer contained in the coating liquid in Test Example 2-5 was changed to an acrylic monomer with lower adhesion to each transparent film.

[0150] [Test Example 2-8] A light-control sheet of Test Example 2-8 was obtained in the same manner as in Test Example 2-6, except that the time for irradiating the coating liquid with ultraviolet light was shortened.

[0151] [Measurement method and evaluation results] From each light-controlling sheet, a first test piece having a width of 2 mm, a test piece having a width of 5 mm, a test piece having a width of 10 mm, a test piece having a width of 15 mm, a test piece having a width of 20 mm, and a test piece having a width of 25 mm were cut out. The peel strength of each test example was measured using a method based on 6.9.3 a) 180-degree peel test of JIS A 5759:2016 "Films for Architectural Window Glass." The evaluation results of the peel strength are shown in Figure 20. A small tabletop testing machine (Shimadzu Corporation, EZ-LX) was used to measure the peel strength.

[0152] After preparing the light-controlling sheet using the same method as in each test example, a groove penetrating the transparent electrode layer was formed on the side of the first transparent film opposite the side facing the light-controlling layer using a cutting plotter. This resulted in the formation of narrowed sections with the following widths: narrowed sections with a width of 2 mm, 5 mm, 10 mm, 15 mm, 20 mm, and 25 mm in the transparent electrode layer of the first transparent film. This resulted in the formation of one first drive region adjacent to the connection region, a conductive section including a narrowed section, and one second drive region for each conductive section in the light-controlling sheet. The second drive region was connected to the first drive region through the conductive section to which the second drive region was connected, but was not electrically connected to other regions of the light-controlling sheet.

[0153] As shown in Figure 20, in each test example, the peel strength of the test specimen increased with increasing specimen width. In test example 2-1, the peel strength was found to be within the range of 0.022 N to 0.616 N, and in test example 2-2, the peel strength was found to be within the range of 0.025 N to 0.610 N. In test example 2-3, the peel strength was found to be within the range of 0.021 N to 0.530 N, and in test example 2-4, the peel strength was found to be within the range of 0.019 N to 0.469 N. In test example 2-5, the peel strength was found to be within the range of 0.014 N to 0.400 N, and in test example 2-6, the peel strength was found to be within the range of 0.015 N to 0.380 N. In Test Example 2-7, the peel strength was found to be within the range of 0.007 N or more and 0.200 N or less, and in Test Example 2-8, the peel strength was found to be within the range of 0.002 N or more and 0.060 N or less.

[0154] For each light-controlling sheet with a narrowed portion formed, we evaluated whether the diffuse transmittance of the second driving region would change by applying a voltage between the transparent electrode layer of the first transparent film and the transparent electrode layer of the second transparent film.In the light-controlling sheets of Test Example 2-1 to Test Example 2-6, it was found that the diffuse transmittance changed in all second driving regions between the state where a voltage was applied between the transparent electrode layers and the state where it was not applied, regardless of the width of the narrowed portion included in the conductive portion connecting the first driving region to the second driving region.

[0155] In contrast, in the light-adjusting sheet of Test Example 2-7, when the width of the narrowed portion was in the range of 5 mm to 25 mm, the diffuse transmittance was found to change in the second drive region, but when the width of the narrowed portion was 2 mm, the diffuse transmittance was found to remain unchanged in the second drive region.Furthermore, in the light-adjusting sheet of Test Example 2-8, when the width of the narrowed portion was in the range of 10 mm to 25 mm, the diffuse transmittance was found to change in the second drive region, but when the width of the narrowed portion was 5 mm or less, the diffuse transmittance was found to remain unchanged in the second drive region.

[0156] When the cross-sectional structure of the conductive portion was examined in Test Examples 2-7 and 2-8, peeling was observed in the conductive portion when the narrowed portion width was 2 mm in Test Example 2-7. Furthermore, peeling was observed in the conductive portion when the narrowed portion width was 2 mm and when the narrowed portion width was 5 mm in Test Example 2-8. Therefore, it can be said that the lack of change in the diffuse transmittance of the second driving region was caused by peeling in the portion including the narrowed portion. In other words, in the light-controlling sheet, by having a peel strength of 0.01 N or more between the narrowed portion of the first transparent electrode layer and the second transparent electrode layer, peeling in the narrowed portion can be suppressed, thereby suppressing poor conductivity caused by peeling.

[0157] Furthermore, as is clear from the results of peel strength measurements, if the peel strength of the light-controlling sheet is 0.380 N / mm or more, peeling of the narrowed portion will not occur even when a narrowed portion having a width of 2 mm is formed.

[0158] FIG. 21 shows the relationship between the peel strength of a 10 mm wide test specimen in each test example and the peel strength of a 5 mm wide test specimen in that test example, and also the relationship between the peel strength of a 10 mm wide test specimen in each test example and the peel strength of a 2 mm wide test specimen in that test example.

[0159] 21 and as described above, it was confirmed that peeling in the area including the narrowed portion can be suppressed by ensuring that the peel strength between the narrowed portion and the second transparent electrode layer is 0.01 N or more, regardless of the width of the narrowed portion. Furthermore, it was confirmed that peeling in the narrowed portion can be suppressed even when a narrowed portion having a width of 2 mm is formed, so long as the peel strength per unit length of 10 mm is 0.100 N or more. [Explanation of symbols]

[0160] 10...Light-adjusting sheet 12A...first transparent electrode layer 12B...Second transparent electrode layer 13A...First transparent support layer 13B…Second transparent support layer 26, 27...Conductive section 30...Drive electrode element 30A…Stenosis 31...Floating electrode element 120...Groove 122, 124...Opening

Claims

1. a first transparent electrode layer; A second transparent electrode layer; a light-controlling layer located between the first transparent electrode layer and the second transparent electrode layer; A light-controlling sheet comprising: a first transparent support layer located on the opposite side of the light-controlling layer with respect to the first transparent electrode layer, the first transparent support layer having a support surface that supports the first transparent electrode layer; The light-control sheet is a first connection region including a first terminal portion for applying a voltage to the first transparent electrode layer, the first connection region being bordered by a portion of the first transparent electrode layer that is exposed from the light control layer; a second connection region including a second terminal portion for applying a voltage to the second transparent electrode layer, the second connection region being bordered by a portion of the second transparent electrode layer that is exposed from the light control layer; The first transparent electrode layer is a groove extending along the support surface and penetrating the first transparent electrode layer; a driving electrode element to which the voltage is applied; a floating electrode element insulated from the drive electrode element by the groove, the floating electrode element being insulated from the drive electrode element by the groove; a direction in which the first connection region and the second connection region are aligned is a first direction; a shortest distance between a straight line passing through the first connection region along the first direction and a straight line passing through the groove along the first direction is 5 mm or more and 50 mm or less; a non-driving region including the groove and the floating electrode element has a first end and a second end, and divides the driving electrode element into a second driving electrode element surrounded by the non-driving region and a first driving electrode element located outside the non-driving region; the first transparent electrode layer includes a narrowed portion sandwiched between the grooves, the narrowed portion connecting the first drive electrode element to the second drive electrode element; The width of the narrowed portion is 1 mm or more, a distance between a straight line passing through the first connection region along the first direction and a straight line passing through the narrowed portion along the first direction is longer than the shortest distance; Dimming sheet.

2. In the first transparent electrode layer, a region adjacent to the first connection region is a unit region, the unit area extends along the first direction and is separated from the first connection area by the straight line passing through the first connection area; The length of the unit area in the first direction is 100 mm, The length of the unit area in a second direction perpendicular to the first direction is 100 mm, In the unit area, the percentage of the area of ​​the floating electrode element to the total area of ​​the driving electrode element and the floating electrode element is 30% or more. The light-controlling sheet according to claim 1 .

3. the light-modulating layer contains a liquid crystal composition, The groove penetrates the first transparent electrode layer in the thickness direction of the light-controlling sheet and extends halfway through the first transparent support layer, The liquid crystal composition is located in the groove. The light-controlling sheet according to claim 1 or 2.

4. the light-modulating layer contains a liquid crystal composition, the groove penetrates through the first transparent electrode layer and the first transparent support layer in the thickness direction of the light-controlling sheet, The liquid crystal composition is located in the groove. The light-controlling sheet according to claim 1 or 2.

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