Light-adjusting sheet

Abstract

To provide a light control sheet that can inhibit the proliferation of virus in the light control sheet.SOLUTION: A light control sheet 21 has a first transparent electrode layer 34, a second transparent electrode layer 35, a light control layer 31 located between the first transparent electrode layer 34 and the second transparent electrode layer 35, a first transparent support layer 36 located on the opposite side of the first transparent electrode layer 34 from the light control layer 31, and an antiviral layer 41 located on the opposite side of the first transparent support layer 36 from the first transparent electrode layer 34 and including an antiviral agent.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] The light-controlling sheet includes a first transparent electrode layer, a second transparent electrode layer, and a light-controlling layer located between the first and second transparent electrode layers. In one example of a light-controlling sheet, the light-controlling layer includes a transparent polymer layer having a plurality of voids and a liquid crystal composition filling the voids. In this light-controlling sheet, for example, when no voltage is applied to the light-controlling layer, the light-controlling layer is opaque, whereas when a voltage is applied to the light-controlling layer, the light-controlling layer is transparent. When the light-controlling layer is opaque, it is difficult to see objects through the light-controlling layer. For this reason, the application of light-controlling sheets to partitions and windows that separate spaces requiring privacy from the outside has been considered (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-67785 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the state of a light-controlling sheet can be switched between transparent and opaque simply by switching between applying and not applying a voltage to the light-controlling layer. Therefore, the state of the light-controlling sheet can be changed in a shorter time than, for example, opening and closing a fabric curtain. Therefore, light-controlling sheets are being considered for use in environments where privacy can be instantly created, such as medical institutions. With the expansion of environments in which light-controlling sheets are used, there is a new demand for light-controlling sheets to contribute to increasing the safety of the environments in which they are used. [Means for solving the problem]

[0005] A light-controlling sheet that solves the above problems 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, a first transparent support layer located on the opposite side of the first transparent electrode layer from the light-controlling layer, and an antiviral layer located on the opposite side of the first transparent support layer from the first transparent electrode layer and containing an antiviral agent. With this light-controlling sheet, the antiviral agent contained in the antiviral layer suppresses the proliferation of viruses in the light-controlling sheet.

[0006] The above-mentioned light-controlling sheet may further comprise an alignment layer sandwiched between the first transparent electrode layer and the light-controlling layer, the first alignment layer being configured to increase the haze of the light-controlling layer by applying a voltage to the first transparent electrode layer, and the light-controlling layer comprising a resin layer positioned between the first transparent electrode layer and the second transparent electrode layer and having voids dispersed therein, and a liquid crystal composition containing liquid crystal molecules and filling the voids, and further comprising a first high-density portion in which the density of the liquid crystal composition per unit thickness is high, and a low-density portion in which the density of the liquid crystal composition per unit thickness is lower than that of the first high-density portion, and the first high-density portion may be in contact with the first alignment layer.

[0007] In the light-controlling sheet, the density of the liquid crystal composition is high in the region close to the alignment layer, so that it is possible to increase the number of liquid crystal molecules aligned by the alignment force of the alignment layer, thereby improving the transparency of the light-controlling sheet when no potential difference is generated between the first transparent electrode layer and the second transparent electrode layer.

[0008] The light-adjusting sheet may further include a covering layer located between the first transparent support layer and the antiviral layer, wherein the first transparent support layer includes a support surface that supports the first transparent electrode layer and a protected surface that is the surface opposite the support surface, the first transparent electrode layer includes first electrode elements and second electrode elements, the first electrode elements and the second electrode elements are separate layered bodies aligned along the support surface and are electrically insulated from each other by grooves extending in a direction along the support surface, the thickness direction of the first transparent electrode layer is the depth direction of the grooves, the grooves penetrate the first transparent support layer and the first transparent electrode layer in the depth direction, and have openings in the protected surface, the openings being covered by the covering layer.

[0009] With the light-adjusting sheet, the light transmittance of the region where the first electrode element is located and the region where the second electrode element is located can be changed by applying a voltage signal to only one of the first electrode element and the second electrode element, or by applying different voltage signals to the first electrode element and the second electrode element. Therefore, it is possible to switch between a state in which there is no difference in light transmittance between the regions where these electrode elements are located without applying a voltage signal to both the first electrode element and the second electrode element, and a state in which there is a difference in light transmittance between the regions where each electrode element is located, as described above, thereby improving the design of the light-adjusting sheet.

[0010] In the above-mentioned light-controlling sheet, the first transparent support layer includes a support surface that supports the first transparent electrode layer, and the first transparent electrode layer includes first electrode elements and second electrode elements, the first electrode elements and the second electrode elements being separate layered bodies aligned along the support surface and electrically insulated from each other by grooves extending along the support surface, the depth direction of the grooves being the thickness direction of the first transparent electrode layer, and the grooves having a depth that penetrates the first transparent electrode layer but does not penetrate the first transparent support layer.

[0011] According to the light-controlling sheet, the light transmittance of the region where the first electrode element is located and the region where the second electrode element is located can be changed by applying a voltage signal to only one of the first electrode element and the second electrode element, or by applying different voltage signals to the first electrode element and the second electrode element. This allows switching between a state where there is no difference in light transmittance between the regions where the first electrode element and the second electrode element are located without applying a voltage signal to both the first electrode element and the second electrode element, and a state where there is a difference in light transmittance between the regions where the electrode elements are located, as described above, thereby improving the design of the light-controlling sheet. Furthermore, because the grooves have a depth that penetrates the first transparent electrode layer but does not penetrate the first transparent electrode layer, light scattering by the grooves is suppressed on the surface of the first transparent support layer opposite the support surface. As a result, the grooves are less noticeable when the light-controlling sheet is viewed from the first transparent electrode layer side, at least from a position facing the opposite surface. This improves the aesthetic appearance of the light-controlling sheet.

[0012] In the above-mentioned light-controlling sheet, the first transparent support layer includes a support surface that supports the first transparent electrode layer, and the first transparent electrode layer includes a first electrode element and a second electrode element, the first electrode element and the second electrode element being separate layer bodies aligned along the support surface and electrically insulated from each other by a groove extending along the support surface, and the first electrode element has a narrowed portion sandwiched between the grooves, and the width of the narrowed portion may be 1 mm or more.

[0013] According to the light-controlling sheet, the light transmittance of the region where the first electrode element is located and the region where the second electrode element is located can be changed by applying a voltage signal to only one of the first electrode element and the second electrode element, or by applying different voltage signals to the first electrode element and the second electrode element. Therefore, by changing the state of the voltage signal applied to these regions, it is possible to make a pattern appear on the light-controlling sheet, improving the design of the light-controlling sheet. Furthermore, because the width of the constriction portion provided in the first electrode element is 1 mm or more, peeling of the first transparent electrode layer or the first transparent support layer is unlikely to occur during or after the groove formation process. Furthermore, conductivity within the same electrode element can be ensured at the constriction portion. This suppresses conduction defects due to increased resistance at the constriction portion and allows appropriate control of the light transmittance of the first electrode element and the second electrode element. Therefore, patterns can be clearly displayed on the light-controlling sheet, improving the design of the light-controlling sheet. [Effects of the Invention]

[0014] According to the present invention, it is possible to suppress the proliferation of viruses on the light-control sheet. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view showing the structure of a light-adjusting device including a light-adjusting sheet according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the structure of an antiviral film provided in the light control device shown in FIG. [Figure 3] FIG. 10 is a cross-sectional view showing the structure of a light control device according to a second embodiment together with a drive unit. [Figure 4] 2 is a cross-sectional view schematically showing an example of the structure of a light controlling sheet provided in the light controlling device shown in FIG. 1. FIG. [Figure 5] 1. FIG. 4 is a cross-sectional view schematically showing another example of the structure of the light controlling sheet provided in the light controlling device shown in FIG. [Figure 6] 1 is an SEM image of the cross-sectional structure of the light-modulating sheet of Test Example 1-1. [Figure 7] 1 is an SEM image of the cross-sectional structure of the light-modulating sheet of Test Example 1-2. [Figure 8] 1 is an SEM image of the cross-sectional structure of the light-control sheet of Test Example 1-3. [Figure 9] 1 is an SEM image of the cross-sectional structure of the light-control sheet of Test Example 1-4. [Figure 10] 1 is an SEM image of the cross-sectional structure of the light-modulating sheet of Test Example 1-5. [Figure 11] 1 is an SEM image of the cross-sectional structure of the light-control sheet of Test Example 1-6. [Figure 12] 1 is an SEM image of the cross-sectional structure of the light-control sheet of Test Example 1-7. [Figure 13] 1 is an SEM image of the cross-sectional structure of the light-control sheet of Test Example 1-8. [Figure 14] 10 is an SEM image of the cross-sectional structure of the light-control sheet of Test Example 1-9. [Figure 15] 10 is an SEM image of the cross-sectional structure of the light-modulating sheet of Test Example 1-10. [Figure 16] 10 is an SEM image of the cross-sectional structure of the light-control sheet of Test Example 1-11. [Figure 17] 10 is an SEM image of the cross-sectional structure of the light-control sheet of Test Example 1-12. [Figure 18] 10 is an SEM image of the cross-sectional structure of the light-control sheet of Test Example 1-13. [Figure 19] FIG. 10 is a plan view showing the structure of a light controlling sheet in a third embodiment. [Figure 20] FIG. 20 is a cross-sectional view showing the structure taken along line II of FIG. 19. [Figure 21] FIG. 20 is a cross-sectional view showing a first example of the structure taken along line II-II in FIG. [Figure 22] FIG. 20 is a cross-sectional view showing a second example of the structure taken along line II-II in FIG. [Figure 23] FIG. 20 is a cross-sectional view showing a third example of the structure taken along line II-II in FIG. [Figure 24] FIG. 10 is a schematic diagram illustrating one step included in the method for producing a light controlling sheet according to the third embodiment. [Figure 25] FIG. 10 is a schematic diagram illustrating one step included in the method for producing a light controlling sheet according to the third embodiment. [Figure 26] FIG. 10 is a schematic diagram illustrating one step included in the method for producing a light controlling sheet according to the third embodiment. [Figure 27] FIG. 10 is a schematic diagram illustrating one step included in the method for producing a light controlling sheet according to the third embodiment. [Figure 28] FIG. 11 is a plan view showing the structure of a light controlling sheet in a non-driven state in a third embodiment. [Figure 29] FIG. 10 is a cross-sectional view showing the structure of a light controlling sheet in a modified example. [Figure 30] FIG. 10 is a plan view showing the structure of a light controlling sheet in a modified example. [Figure 31] FIG. 10 is a plan view showing the structure of a normal-type light controlling sheet in a fourth embodiment. [Figure 32] FIG. 2 is a cross-sectional view showing the structure of the light controlling sheet of the same embodiment. [Figure 33] FIG. 2 is a cross-sectional view showing the structure of the light controlling sheet of the same embodiment. [Figure 34] FIG. 2 is an enlarged view of the cross-sectional structure of the light controlling sheet of the embodiment. [Figure 35] 1 is an SEM image showing the cross-sectional structure of the light controlling sheet of the same embodiment. [Figure 36] 3 is a schematic diagram illustrating one step included in the manufacturing method of the light controlling sheet of the same embodiment. FIG. [Figure 37] FIG. 2 is a plan view showing the structure of a light controlling sheet in a non-driven state in the same embodiment. [Figure 38] FIG. 10 is a plan view showing the structure of a light controlling sheet in a driven state in a modified example. [Figure 39] FIG. 10 is a cross-sectional view showing the structure of a light controlling sheet in a modified example. [Figure 40] FIG. 10 is a plan view showing the structure of a normal-type light controlling sheet in a fifth embodiment. [Figure 41]FIG. 41 is a cross-sectional view taken along line VV shown in FIG. [Figure 42] FIG. 41 is a cross-sectional view taken along line VI-VI shown in FIG. [Figure 43] 41 is an enlarged plan view showing a part of the light controlling sheet shown in FIG. 40. FIG. [Figure 44] 41 is an enlarged plan view showing a part of the light controlling sheet shown in FIG. 40. FIG. [Figure 45] 41 is an enlarged plan view showing a part of the light controlling sheet shown in FIG. 40. FIG. [Figure 46] 3A to 3C are diagrams schematically showing a method for manufacturing the light controlling sheet of the same embodiment. [Figure 47] FIG. 2 is a plan view showing the structure of a light controlling sheet in a non-driven state in the same embodiment. [Figure 48] FIG. 10 is a cross-sectional view showing the structure of a light controlling sheet according to a sixth embodiment. [Figure 49] FIG. 10 is a plan view showing the structure of a modified light controlling sheet. [Figure 50] FIG. 10 is a plan view showing the structure of a reverse-type light controlling sheet according to a modified example. [Figure 51] FIG. 10 is a cross-sectional view showing the structure of a modified light controlling sheet. [Figure 52] FIG. 10 is a cross-sectional view showing the structure of a modified light controlling sheet. [Figure 53] FIG. 10 is a cross-sectional view showing the structure of a modified light controlling sheet. [Figure 54] FIG. 10 is a front view showing the structure of a modified light controlling sheet. [Figure 55] FIG. 10 is a front view showing the structure of a modified light controlling sheet. [Figure 56] FIG. 2 is a plan view showing the shape of a measurement sample for measuring a resistance value. [Figure 57] 10 is a table showing resistance values ​​of test examples. [Figure 58] 10 is a table showing effective voltages in test examples. [Figure 59] 1 is a table showing the peel strength of test examples. [Figure 60] 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

[0016] [First embodiment] A first embodiment of the light controlling sheet will be described with reference to FIGS.

[0017] [Light control device] A light control device including a light control sheet will be described with reference to FIG. As shown in FIG. 1, the light control device 10 includes a light control unit 11 including a reverse-type light control sheet 21, and a drive unit 12.

[0018] The light-controlling sheet 21 includes a light-controlling layer 31, a first alignment layer 32, a second alignment layer 33, a first transparent electrode layer 34, and a second transparent electrode layer 35. In the light-controlling sheet 21, the first alignment layer 32 and the second alignment layer 33 sandwich the light-controlling layer 31 in the thickness direction of the light-controlling layer 31. The first transparent electrode layer 34 and the second transparent electrode layer 35 sandwich the pair of alignment layers 32, 33 in the thickness direction of the light-controlling layer 31. The light-controlling sheet 21 further includes a first transparent substrate 36 that supports the first transparent electrode layer 34, and a second transparent substrate 37 that supports the second transparent electrode layer 35. The first transparent substrate 36 is an example of a first transparent support layer.

[0019] The dimming unit 11 includes a first electrode 22A attached to a portion of the first transparent electrode layer 34 and a second electrode 22B attached to a portion of the second transparent electrode layer 35. The dimming unit 11 further includes a first wiring 23A connected to the first electrode 22A and a second wiring 23B connected to the second electrode 22B. The first electrode 22A is connected to the driving unit 12 by the first wiring 23A, and the second electrode 22B is connected to the driving unit 12 by the second wiring 23B.

[0020] The light-controlling layer 31 includes a transparent resin layer and a liquid crystal composition. The resin layer has voids into which the liquid crystal composition is filled. The voids in the resin layer are filled with the liquid crystal composition. The liquid crystal composition contains liquid crystal molecules. The liquid crystal molecules are negative-type liquid crystal molecules with negative dielectric anisotropy. 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.

[0021] The liquid crystal composition holding type is any one selected from the group consisting of a polymer network type, a polymer dispersion type, and a capsule type. The polymer network type has a transparent polymer network with a three-dimensional mesh structure, and holds the liquid crystal composition in the interconnected voids of the mesh. The polymer network is an example of a resin layer. The polymer dispersion type has a large number of isolated voids in a resin layer, and holds the liquid crystal composition in the voids dispersed in the polymer layer. The capsule type holds a liquid crystal composition having an encapsulated shape in a resin layer. In addition to the above-mentioned liquid crystal molecules, the liquid crystal composition may also contain a monomer for forming a resin layer, a dichroic dye, etc.

[0022] The materials for forming the first alignment layer 32 and the second alignment layer 33 are organic compounds, inorganic compounds, and mixtures 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 alignment layers 32 and 33 may be silicone. Silicon is a compound having an inorganic portion and an organic portion. The thickness of each alignment layer 32 and 33 is, for example, 0.02 μm or more and 0.5 μm or less.

[0023] The first alignment layer 32 and the second alignment layer 33 are, for example, vertical alignment layers that align the long axes of the liquid crystal molecules so that they are perpendicular to the surface opposite to the surface in contact with the first transparent electrode layer 34 and the surface opposite to the surface in contact with the second transparent electrode layer 35.

[0024] The first transparent electrode layer 34 and the second transparent electrode layer 35 are optically transparent, allowing visible light to pass through. The optical transparency of the first transparent electrode layer 34 allows visual recognition of objects through the light-controlling sheet 21. The optical transparency of the second transparent electrode layer 35, like the optical transparency of the first transparent electrode layer 34, allows visual recognition of objects through the light-controlling sheet 21. The thickness of each transparent electrode layer 34, 35 may be, for example, 0.005 μm or more and 0.1 μm or less. This makes it possible to reduce cracks when the light-controlling sheet 21 is flexed while ensuring proper operation.

[0025] The material for forming each of the transparent electrode layers 34, 35 may be, for example, any one selected from the group consisting of indium tin oxide, fluorine-doped tin oxide, tin oxide, zinc oxide, carbon nanotubes, and poly(3,4-ethylenedioxythiophene).

[0026] The material forming each of the transparent substrates 36, 37 may be a synthetic resin or an inorganic compound. Examples of synthetic resins include polyester, polyacrylate, polycarbonate, and polyolefin. Examples of polyesters include polyethylene terephthalate and polyethylene naphthalate. Examples of polyacrylates include polymethyl methacrylate. Examples of inorganic compounds include silicon dioxide, silicon oxynitride, and silicon nitride. The thickness of each of the transparent substrates 36, 37 is, for example, 16 μm or more and 250 μm or less. Having a thickness of 16 μm or more for the transparent substrates 36, 37 prevents difficulties in processing and applying the light controlling sheet 21. Having a thickness of 250 μm or less for the transparent substrates 36, 37 prevents difficulties in manufacturing the light controlling sheet 21 using a roll-to-roll process.

[0027] Each of the electrodes 22A, 22B is, for example, a flexible printed circuit (FPC). The FPC includes a support layer, a conductor portion, and a protective layer. The conductor portion is sandwiched between the support layer and the protective layer. The support layer and the protective layer are made of insulating synthetic resin. The support layer and the protective layer are made of, for example, polyimide. The conductor portion is made of, for example, a metal thin film. The material for forming the metal thin film may be, for example, copper. Each of the electrodes 22A, 22B is not limited to an FPC, and may be, for example, a metal tape.

[0028] Each of the electrodes 22A and 22B is attached to each of the transparent electrode layers 34 and 35 by a conductive adhesive layer (not shown). In each of the electrodes 22A and 22B, the conductor portion is exposed from the protective layer or the support layer at the portion connected to the conductive adhesive layer.

[0029] The conductive adhesive layer may be formed of, for example, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), an isotropic conductive film (ICF), an isotropic conductive paste (ICP), etc. From the viewpoint of ease of handling in the manufacturing process of the light control device 10, the conductive adhesive layer is preferably an anisotropic conductive film.

[0030] Each of the wirings 23A and 23B is formed of, for example, a metal wire and an insulating layer covering the metal wire. The wire is formed of, for example, copper.

[0031] The driving unit 12 applies an AC voltage between the first transparent electrode layer 34 and the second transparent electrode layer 35. The driving unit 12 preferably applies an AC voltage having a rectangular waveform between the pair of transparent electrode layers 34, 35. The driving unit 12 may also apply an AC voltage having a waveform other than a rectangular waveform between the pair of transparent electrode layers 34, 35. For example, the driving unit 12 may apply an AC voltage having a sine wave between the pair of transparent electrode layers 34, 35.

[0032] The light-controlling layer 31 changes the orientation of the liquid crystal molecules in response to a change in voltage generated between the two transparent electrode layers 34, 35. The change in orientation of the liquid crystal molecules changes the degree of scattering, absorption, and transmission of visible light entering the light-controlling layer 31. The reverse-type light-controlling sheet 21 has a relatively high haze when the light-controlling sheet 21 is energized, i.e., when a potential difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35. The reverse-type light-controlling sheet 21 has a relatively low haze when the light-controlling sheet 21 is not energized, i.e., when no potential difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35. For example, the reverse-type light-controlling sheet 21 is opaque when the light-controlling sheet 21 is energized and transparent when the light-controlling sheet 21 is not energized.

[0033] The light controlling sheet 21 is attached to windows of moving objects such as vehicles and aircraft. The light controlling sheet 21 is also attached to windows of various buildings such as homes, train stations, and airports, partitions installed in offices, medical institutions, and nursing homes, show windows installed in stores, and screens for projecting images. The light controlling sheet 21 may be flat or curved.

[0034] The light controlling sheet 21 further includes a first antiviral film 41 and a second antiviral film 42. The first antiviral film 41 is located on the surface of the first transparent base material 36 opposite to the surface on which the first transparent electrode layer 34 is located. The second antiviral film 42 is located on the surface of the second transparent base material 37 opposite to the surface on which the second transparent electrode layer 35 is located.

[0035] 1, the light controlling sheet 21 includes the first antiviral film 41 and the second antiviral film 42, but the light controlling sheet 21 may include only one of the first antiviral film 41 and the second antiviral film 42. When the light controlling sheet 21 includes the first antiviral film 41 and the second antiviral film 42, the virus-reducing effect of the light controlling sheet 21 is enhanced and the difference in appearance between the front and back of the light controlling sheet 21 can be reduced.

[0036] 2 shows the cross-sectional structure of the first antiviral film 41. Note that while the second antiviral film 42 is attached to an object different from the object to which the first antiviral film 41 is attached, it has a cross-sectional structure in common with the first antiviral film 41. Therefore, the following description will focus on the cross-sectional structure of the first antiviral film 41, but will omit a description of the cross-sectional structure of the second antiviral film 42.

[0037] As shown in Fig. 2, the first antiviral film 41 includes a base layer 41A, an antiviral layer 41B, and an adhesive layer 41C. The base layer 41A has a pair of opposing surfaces, with the antiviral layer 41B located on one surface and the adhesive layer 41C located on the other surface. The base layer 41A is made of, for example, polyethylene phthalate or polyolefin. The base layer 41A has a thickness of, for example, 80 µm or more and 120 µm or less.

[0038] The adhesive layer 41C may have high adhesion to the target, but may not be removable from the target, or may be removable but not re-attachable. Alternatively, the adhesive layer 41C may have low adhesion to the target, but may be reversibly removable from and reattached to the target. The adhesive layer 41C having high adhesion is formed, for example, from an olefin-based adhesive. The adhesive layer 41C having low adhesion is formed, for example, from a polyethylene terephthalate-based adhesive or an olefin-based adhesive. The adhesive layer 41C has a thickness of, for example, several μm. The antiviral film 41 is attached to the first transparent substrate 36, which is the target, by the adhesive layer 41C.

[0039] The antiviral layer 41B contains a synthetic resin and an antiviral agent. The antiviral agent contained in the antiviral layer 41B suppresses the proliferation of viruses in the light controlling sheet 21. Therefore, the light controlling sheet 21 can contribute to increasing the safety of the space defined by the light controlling sheet 21.

[0040] The synthetic resin may be, for example, a melamine-based resin, a urethane-based resin, an acrylic-based resin, or the like. The synthetic resin may be an ultraviolet-curable resin. The antiviral agent may be, for example, an organic antiviral agent. The organic antiviral agent may be, for example, bis(2-pyridylthio)zinc 1,1'-dioxide, 2-(4-thiazolyl)benzimidazole, or an organic nitrogen-sulfur-halogen compound.

[0041] The antiviral agent may be composed of, for example, a porous substance and metal ions supported on the porous substance. The porous substance may be, for example, zeolite, apatite, zirconia, etc. The metal ions may be silver ions, copper ions, zinc ions, etc. The antiviral agent may have an antibacterial function in addition to an antiviral function.

[0042] The metal ions carried by the porous material have a positive charge, and therefore, when an AC voltage is applied between the pair of transparent electrode layers 34 and 35, the metal ions may migrate in the thickness direction of the first antiviral film 41.

[0043] As described above, the antiviral layer 41B containing the antiviral agent is separated from the transparent base materials 36, 37 by the base material layer 41A and the adhesive layer 41C. This prevents metal ions from migrating outside the antiviral films 41, 42 and inside the antiviral films 41, 42 in the light controlling sheet 21 in response to the application of an AC voltage.

[0044] When the light controlling sheet 21 includes the antiviral films 41 and 42, an increase in the electrostatic capacitance of the light controlling sheet 21 is suppressed compared to when the transparent base materials 36 and 37 contain an antiviral agent. Furthermore, because the antiviral layers 41B of the antiviral films 41 and 42 contain an antiviral agent, the antiviral agent is prevented from migrating further inward into the light controlling sheet 21 than the antiviral films 41 and 42 compared to when the adhesive layer contains an antiviral agent. Furthermore, when the light controlling sheet 21 includes the antiviral films 41 and 42, uneven distribution of metal ions within the light controlling layer 31 is suppressed compared to when the light controlling layer 31 contains an antiviral agent, thereby suppressing deterioration of the light controlling layer 31. Even when the antiviral agent is an organic antiviral agent, the antiviral films 41 and 42 suppress reaction between the liquid crystal molecules LCM contained in the light controlling layer 31 and the antiviral agent, thereby suppressing deterioration of the light controlling layer 31.

[0045] When forming the antiviral layer 41B, for example, a coating liquid containing the above-mentioned synthetic resin, antiviral agent, and solvent is prepared. The coating liquid is applied to one surface of the base material layer 41A, and then cured to form the antiviral layer 41B.

[0046] From the viewpoint of further enhancing the privacy protection function of the light controlling sheet 21, the antiviral films 41, 42 preferably have a haze of 30% or more. From the viewpoint of further enhancing the transparency of the light controlling sheet 21 when no voltage is applied, the antiviral films 41, 42 preferably have a haze of less than 30%.

[0047] As described above, according to the first embodiment of the light controlling sheet, the following effects can be obtained. (1-1) The antiviral agent contained in the antiviral layer 41B suppresses the proliferation of viruses in the light controlling sheet 21. Therefore, the light controlling sheet 21 can contribute to increasing the safety of the space defined by the light controlling sheet 21.

[0048] (1-2) By providing the light-control sheet 21 with the first antiviral film 41 and the second antiviral film 42, the light-control sheet 21 is more effective in reducing viruses and the difference in appearance between the front and back of the light-control sheet 21 can be reduced.

[0049] (1-3) In the antiviral film 41, the antiviral layer 41B is separated from the transparent base materials 36 and 37 by the base material layer 41A and the adhesive layer 41C. Therefore, even if the antiviral layer 41B contains metal ions, the metal ions are prevented from migrating inward from the antiviral films 41 and 42 in response to the application of an AC voltage.

[0050] [Modification of the first embodiment] The above-described first embodiment can be modified and implemented as follows. [Anti-viral film] The light controlling sheet 21 may have only the antiviral layer of the above-mentioned antiviral films 41, 42. That is, the light controlling sheet 21 may have an antiviral layer located on each of the transparent substrates 36, 37. Alternatively, the light controlling sheet 21 may have an antiviral layer on only one of the first transparent substrate 36 and the second transparent substrate 37. The antiviral layer is formed by applying the above-mentioned coating liquid to each of the transparent substrates 36, 37.

[0051] In this case, the antiviral light controlling sheet 21 can be made thinner and lighter than when the light controlling sheet 21 includes the antiviral films 41 and 42. In addition, because there is only one layer located outside the transparent base materials 36 and 37, it is also possible to improve optical properties such as light transmittance and haze.

[0052] The light controlling sheet 21 may further include the above-mentioned antiviral films 41, 42 in addition to the antiviral layers located on the transparent base materials 36, 37. In this case, the light controlling sheet 21 includes both the antiviral films 41, 42 and the antiviral layer, thereby enhancing the antiviral properties of the light controlling sheet 21.

[0053] The light controlling sheet 21 may include a pair of antiviral layers and a pair of antiviral films, or may include only one antiviral layer and one antiviral film. When the light controlling sheet 21 includes only one antiviral layer and one antiviral film, the antiviral layer may be located on one of the first transparent substrate 36 and the second transparent substrate 37, and the antiviral film may be located on the other. Alternatively, when the light controlling sheet 21 includes only one antiviral layer and one antiviral film, the antiviral layer may be located on either the first transparent substrate 36 or the second transparent substrate 37, and the antiviral film may be located on the antiviral layer.

[0054] The light controlling sheet 21 may also include a pair of antiviral layers and one antiviral film, or alternatively, the light controlling sheet 21 may include one antiviral layer and a pair of antiviral films.

[0055] The light adjusting body may include the antiviral films 41, 42, not limited to the light adjusting sheet 21 described above. The light adjusting body includes the light adjusting sheet 21 and a transparent support that supports the light adjusting sheet 21. The light adjusting body may include only one transparent support, or may include two transparent supports. When the light adjusting body includes one transparent support, the transparent support is adhered to the first transparent substrate 36 or the second transparent substrate 37 of the light adjusting sheet 21 by a transparent adhesive layer. When the light adjusting body includes two transparent supports, one transparent support is adhered to the first transparent substrate 36 by a transparent adhesive layer, and the other transparent support is adhered to the second transparent substrate 37 by a transparent adhesive layer. The light adjusting body may have antiviral films on both of a pair of surfaces facing each other in the thickness direction of the light adjusting body, or may have an antiviral film on only one of the pair of surfaces.

[0056] The photochromic element may include only the antiviral layer of the antiviral films 41 and 42. That is, the photochromic element may include an antiviral layer located on at least one of a pair of surfaces that face each other in the thickness direction of the photochromic element.

[0057] The photochromic element may include both an antiviral layer and an antiviral film. In this case, the photochromic element may include a pair of antiviral layers and a pair of antiviral films, or may include only one antiviral layer and one antiviral film. When the photochromic element includes only one antiviral layer and one antiviral film, the antiviral layer may be located on one of a pair of opposing surfaces in the thickness direction of the photochromic element, and the antiviral film may be located on the other. Alternatively, the antiviral layer may be located on one of a pair of opposing surfaces in the thickness direction of the photochromic element, and the antiviral film may be located on the antiviral layer.

[0058] The light control body may also include a pair of antiviral layers and one antiviral film, or alternatively, the light control body may include one antiviral layer and a pair of antiviral films.

[0059] The transparent support provided in the light control body may have an antiviral layer on the surface that is bonded to the light control sheet 21 by the adhesive layer.

[0060] [Light-adjusting sheet] The light-controlling sheet may be a normal type. In this case, the light-controlling sheet does not have alignment layers 32 and 33, and the light-controlling layer 31 contains positive-type liquid crystal molecules with positive dielectric anisotropy. A normal type light-controlling sheet has a relatively low haze when the light-controlling sheet is energized and a relatively high haze when the light-controlling sheet is not energized. For example, a normal type light-controlling sheet is transparent when the light-controlling sheet is energized and opaque when the light-controlling sheet is not energized.

[0061] The form of the light-controlling sheet is not limited to a system that switches between transparent and opaque by controlling the orientation of liquid crystal molecules, but may also be an electrochromic system that reversibly promotes a redox reaction depending on the magnitude of the electric field applied to the light-controlling sheet, and changes the light absorption rate as the redox reaction progresses.

[0062] [Second embodiment] A second embodiment of the light controlling sheet will be described with reference to Figures 3 to 18. The light controlling sheet of the second embodiment has a different structure of the light controlling layer compared to the light controlling sheet of the first embodiment. Therefore, these differences will be described in detail below, while detailed description of the commonalities between the light controlling sheet of the second embodiment and the light controlling sheet of the first embodiment will be omitted. The light controlling device, light controlling sheet, and examples will be described in order below.

[0063] [Light control device] The light control device will be described with reference to Fig. 3. For convenience of illustration, the antiviral film provided in the light control device is omitted from Fig. 3. The light control sheet of the second embodiment can include the antiviral film provided in the light control sheet of the first embodiment, and the antiviral film or antiviral layer described in the modified example of the first embodiment.

[0064] As shown in FIG. 3, the light control device 10, like the light control device 10 of the first embodiment, includes a light control unit 11 including a reverse-type light control sheet 21, and a drive unit 12. The light control layer 31 includes a transparent resin layer and a liquid crystal composition. The resin layer has voids into which the liquid crystal composition is filled. The liquid crystal composition fills the voids in the resin layer. The liquid crystal composition includes liquid crystal molecules. Any of the liquid crystal molecules listed in the first embodiment can be used as the liquid crystal molecules.

[0065] The thickness of the light-controlling layer 31 is preferably at least twice the minimum size of the voids and no greater than 10 μm, for example, at least 2 μm and less than 10 μm. Furthermore, the thickness of the light-controlling layer 31 is more preferably at least 3.0 μm and no greater than 8.0 μm. When the thickness of the light-controlling layer 31 is at least twice the size of the voids, at least two regions with relatively different densities, as described below, are likely to be generated within the light-controlling layer 31. Furthermore, when the thickness of the light-controlling layer 31 is 10 μm or less, the liquid crystal molecules and the transparent resin layer are likely to be appropriately separated from each other when a coating liquid containing liquid crystal molecules is exposed to light during the production of the light-controlling sheet 21.

[0066] [Light-adjusting sheet] The structure of the light controlling sheet 21 will be described in more detail with reference to FIGS. 4 and 5 schematically show the cross-sectional structure of the light-controlling sheet 21. For ease of illustration, the transparent substrates 36 and 37 are omitted from FIGS. 4 and 5. For ease of illustrating the structure of the light-controlling layer 31, the ratio of the thickness of the light-controlling layer 31 to the thicknesses of the alignment layers 32 and 33 and the transparent electrode layers 34 and 35 is shown larger than the actual ratio. Furthermore, FIGS. 4 and 5 show the state of the light-controlling layer 31 when no potential difference is generated between the pair of transparent electrode layers 34 and 35.

[0067] As shown in FIG. 4, the light-controlling sheet 21 includes a first transparent electrode layer 34, a second transparent electrode layer 35, a light-controlling layer 31, and a first alignment layer 32, to which a voltage is applied. The light-controlling layer 31 includes a resin layer 31P and a liquid crystal composition 31LC. The resin layer 31P is located between the first transparent electrode layer 34 and the second transparent electrode layer 35, and voids 31D are dispersed in the resin layer 31P. The liquid crystal composition 31LC contains liquid crystal molecules LCM and fills the voids 31D. The first alignment layer 32 is sandwiched between the first transparent electrode layer 34 and the light-controlling layer 31. The first alignment layer 32 is configured to increase the haze of the light-controlling layer 31 upon application of a voltage. The light-controlling layer 31 includes a first high-density portion 31H1 having a high density of the liquid crystal composition 31LC per unit thickness and a low-density portion 31L having a low density of the liquid crystal composition 31LC per unit thickness. The first high density portion 31H1 is in contact with the first alignment layer 32.

[0068] In other words, the density of the liquid crystal composition 31LC is lowest in the middle of the thickness of the switchable layer 31. The middle of the thickness of the switchable layer 31 refers to a portion closer to the center of the switchable layer 31 than the opposing surfaces of the switchable layer 31 in the thickness direction. The density of the liquid crystal composition 31LC per unit thickness in each portion of the switchable layer 31 is calculated by dividing the volume of the liquid crystal composition 31LC contained in each portion by the thickness of the corresponding portion. Preferably, the density of the liquid crystal composition 31LC is lowest in a portion of the switchable layer 31 including the center in the thickness direction. Because the switchable layer 31 is very thin, it is practically difficult to determine the volume of the liquid crystal composition 31LC contained in the switchable layer 31. Therefore, in the present disclosure, the densities are calculated using the area of ​​the liquid crystal composition 31LC and the area of ​​the switchable layer 31, which are determined from an SEM image of a cross section of the switchable layer 31.

[0069] The first alignment layer 32 is, for example, a vertical alignment layer, and typically aligns the liquid crystal molecules LCM so that the long axes of the liquid crystal molecules LCM are perpendicular to the first transparent electrode layer 34. However, the first alignment layer 32 may align the liquid crystal molecules LCM so that the long axes are inclined by several degrees from the vertical, within a range in which the long axes of the liquid crystal molecules LCM are determined to be substantially vertical to the first transparent electrode layer 34. Furthermore, the density of the liquid crystal composition 31LC in the first high density portion 31H1 is higher than the density of the liquid crystal composition 31LC in the low density portion 31L.

[0070] Since the density of the liquid crystal composition 31LC is high in the region that is close to the first alignment layer 32, it is possible to increase the amount of liquid crystal molecules LCM that are aligned by the alignment restriction force of the first alignment layer 32. Therefore, when no potential difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35, the transparency of the light control sheet 21 can be increased.

[0071] The transparency of the light controlling sheet 21 can be expressed by the transmittance of visible light that the light controlling sheet 21 has. The transparency of the light controlling sheet 21 can also be expressed by the haze that the light controlling sheet 21 has. The haze is calculated by a method that complies with JIS K 7136:2000. In the light controlling sheet 21, the lower the haze value, the higher the transparency of the light controlling sheet 21, and the higher the haze value, the lower the transparency of the light controlling sheet 21.

[0072] As described above, the light-controlling sheet 21 further includes a second alignment layer 33 located between the light-controlling layer 31 and the second transparent electrode layer 35 in the thickness direction of the light-controlling layer 31. The light-controlling layer 31 further includes a second high-density portion 31H2. The second high-density portion 31H2 is in contact with the second alignment layer 33 and has a higher density of the liquid crystal composition 31LC than the density of the liquid crystal composition 31LC in the low-density portion 31L. The low-density portion 31L is sandwiched between the first high-density portion 31H1 and the second high-density portion 31H2 in a cross section along the thickness direction of the light-controlling layer 31.

[0073] In the light-controlling layer 31, liquid crystal molecules LCM are aligned in the vicinity of a pair of surfaces that face each other in the thickness direction of the light-controlling layer 31 according to the alignment restricting force of the alignment layers 32 and 33. Therefore, when no potential difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35, the light transmittance of the light-controlling sheet 21 can be further improved. In other words, the haze of the light-controlling sheet 21 can be reduced.

[0074] The photochromic layer 31 is composed of a first high-density portion 31H1, a second high-density portion 31H2, and a low-density portion 31L. In a cross section along the thickness direction of the photochromic layer 31, the density of the voids 31D per unit thickness is the value obtained by dividing the area of ​​the voids 31D by the thickness of the photochromic layer 31. The density of the voids 31D per unit thickness in the first high-density portion 31H1 and the density of the voids 31D per unit thickness in the second high-density portion 31H2 are higher than the density of the voids 31D per unit thickness in the low-density portion 31L.

[0075] Therefore, the density of the liquid crystal composition 31LC in the first high density portion 31H1 and the density of the liquid crystal composition 31LC in the second high density portion 31H2 can be made higher than the density of the liquid crystal composition 31LC in the low density portion 31L. The density of voids 31D per unit thickness is calculated by dividing the sum of the areas of voids 31D included in each portion by the thickness of each portion.

[0076] In the switchable layer 31, for example, the thickness TH1 of the first high-density portion 31H1, the thickness TH2 of the second high-density portion 31H2, and the thickness TL of the low-density portion 31L are approximately equal to one another. That is, the thickness TH1 of the first high-density portion 31H1, the thickness TH2 of the second high-density portion 31H2, and the thickness TL of the low-density portion 31L are approximately one-third of the thickness T31 of the switchable layer 31. The thickness TL of the low-density portion 31L may be thicker or thinner than the thicknesses TH1 and TH2 of the high-density portions 31H1 and 31H2. The thickness TH1 of the first high-density portion 31H1 and the thickness of the second high-density portion 31H2 may be equal to or different from each other.

[0077] In a cross section along the thickness direction of the light-controlling layer 31, the percentage ([SD / SL] × 100) of the sum of the areas (SD) of the voids 31D included in the low-density portions 31L to the area (SL) of the low-density portions 31L is preferably 10% or less. This makes it possible to reduce the proportion of the liquid crystal composition 31LC held by the voids 31D in the low-density portions 31L, thereby preventing the liquid crystal molecules LCM included in the low-density portions 31L from increasing the opacity of the light-controlling sheet 21 when no potential difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35.

[0078] Furthermore, it is preferable that the low-density portions 31L do not have voids 31D. In other words, it is preferable that the low-density portions 31L do not contain the liquid crystal composition 31LC. This makes it easier for all the liquid crystal molecules LCM contained in the light-controlling layer 31 to be aligned in accordance with the alignment restricting force of the alignment layers 32 and 33, thereby further reducing the haze of the light-controlling sheet 21 when no voltage difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35.

[0079] Thus, in the low density portion 31L, the sum SD of the areas of the voids 31D relative to the area SL of the low density portion 31L is preferably 10% or less, more preferably 5% or less, and most preferably 0%.

[0080] Furthermore, in a cross section along the thickness direction of the switchable layer 31, the voids 31D can be located within a range of 3.0 μm or less from the first alignment layer 32 and within a range of 3.0 μm or less from the second alignment layer 33. In other words, the thickness TH1 of the first high density portion 31H1 can be 3.0 μm or less, and the thickness TH2 of the second high density portion 31H2 can be 3.0 μm or less.

[0081] The range of the voids 31D relative to the first alignment layer 32 is the maximum distance between the voids 31D located closer to the first alignment layer 32 than the center of the switchable layer 31 in a cross section along the thickness direction of the switchable layer 31 and the surface of the first alignment layer 32 that contacts the switchable layer 31. The range of the voids 31D relative to the second alignment layer 33 is the maximum distance between the voids 31D located closer to the second alignment layer 33 than the center of the switchable layer 31 in a cross section along the thickness direction of the switchable layer 31 and the surface of the second alignment layer 33 that contacts the switchable layer 31.

[0082] In a cross section along the thickness direction of the dimming layer 31, the gaps 31D are located within a range of 3.0 μm or less from each alignment layer 32, 33, thereby increasing the reliability with which the liquid crystal molecules LCM held in each gap 31D are aligned in accordance with the alignment control force.

[0083] Each void 31D included in the first high density portion 31H1 is preferably in contact with the first alignment layer 32. Furthermore, each void 31D included in the second high density portion 31H2 is preferably in contact with the second alignment layer 33. In other words, the multiple voids 31D provided in the switchable layer 31 are preferably composed of only one void layer along the interface between the first alignment layer 32 and the switchable layer 31, and one void layer along the interface between the second alignment layer 33 and the switchable layer 31.

[0084] Each void 31D included in the first high-density portion 31H1 and each void 31D included in the second high-density portion 31H2 can hold the liquid crystal composition 31LC in contact with the alignment layers 32, 33, and therefore the alignment restricting force of the alignment layers 32, 33 can be easily applied to the entire liquid crystal composition 31LC held in each void 31D. This can further enhance the transparency of the light control sheet 21 when no potential difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35.

[0085] On the other hand, the light controlling sheet 21 of the present disclosure can also be defined by the thickness of the light controlling layer 31 and the size of the voids 31D. That is, in the light controlling sheet 21, the thickness T31 of the light controlling layer 31 is 3.0 μm or more and 8.0 μm or less, and the size of the voids 31D is 1.0 μm or more and 2.5 μm or less.

[0086] Because the thickness of the light-controlling layer 31 is 3.0 μm or more and 8.0 μm or less, the formation of voids 31D at positions away from a pair of opposing surfaces in the thickness direction of the light-controlling layer 31 is suppressed. Furthermore, because the size of the voids 31D is 1.0 μm or more and 2.5 μm or less, the liquid crystal composition 31LC is held in the vicinity of the alignment layers 32 and 33. This makes it possible to enhance the transparency of the light-controlling sheet 21 when no voltage difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35.

[0087] From the viewpoint of the scattering characteristics of the light controlling sheet 21, the size of the voids 31D is preferably 0.38 μm or more and 3.0 μm or less. By setting the size of the voids 31D within the range of 0.38 μm or more and 3.0 μm or less, it is possible to achieve an appropriate level of scattering in the light controlling sheet 21. By setting the size of the voids 31D to 0.38 μm or more, scattering characteristics, particularly scattering characteristics in the visible range, are sufficiently ensured. By setting the size of the voids 31D to 3.0 μm or less, the optical effect of the liquid crystal, i.e., the component of light that passes through the voids is prevented from becoming greater than the component of light that is scattered, thereby making it easier to achieve an appropriate light controlling effect.

[0088] When the voids 31D have a circular shape in a cross section along the thickness direction of the light controlling sheet 21, the size of the voids 31D is the diameter of the voids 31D. When the voids 31D have an elliptical shape in a cross section along the thickness direction of the light controlling sheet 21, the size of the voids 31D is the major axis of the voids 31D. When the voids 31D have an irregular shape in a cross section along the thickness direction of the light controlling sheet 21, the size of the voids 31D is the diameter of a circle circumscribing the voids 31D.

[0089] In a cross section along the thickness direction of the light-controlling layer 31, the liquid crystal molecules LCM held at a position closer to each alignment layer 32, 33 are more likely to be aligned according to the alignment restricting force of the alignment layers 32, 33. As described above, when the size of the voids 31D is 2.5 μm or less, the liquid crystal molecules LCM held in each void 31D located in the high-density portions 31H1, 31H2 are more likely to be aligned according to the alignment restricting force.

[0090] When forming the light controlling sheet 21, first, transparent substrates 36 and 37 on which transparent electrode layers 34 and 35 are formed are prepared. Then, alignment layers 32 and 33 are formed on the transparent electrode layers 34 and 35, respectively. Next, a coating liquid is applied between the pair of alignment layers 32 and 33. The coating liquid contains a polymerizable composition for forming a resin layer 31P and liquid crystal molecules LCM. The polymerizable composition is a monomer or oligomer that can be polymerized by irradiation with ultraviolet light. Thereafter, ultraviolet light is irradiated onto the coating liquid through the transparent electrode layers 34 and 35, thereby forming a resin layer 31P having voids 31D, and the liquid crystal molecules LCM are held within the voids 31D.

[0091] When the coating liquid hardens, the liquid crystal composition 31LC containing the liquid crystal molecules LCM is first separated from the polymerizable composition, and the liquid crystal composition 31LC is located in multiple locations within the polymerizable composition. Next, before the polymerizable composition hardens, the liquid crystal composition 31LC migrates toward the alignment layers 32 and 33. The polymerizable composition is then hardened to form a resin layer 31P having voids 31D surrounding the liquid crystal composition 31LC. Until the resin layer 31P is formed, the voids 31D formed in the resin layer 31P continue to expand as the separated liquid crystal compositions 31LC aggregate. In this regard, if the size of the voids 31D is 1.0 μm or greater, it is possible to reduce the possibility that the polymerizable composition will harden before each void 31D migrates to the vicinity of the alignment layers 32 and 33. As a result, it is possible to reduce the number of voids 31D in the low-density portion 31L of the light-controlling layer 31.

[0092] 4 is one example of a possible structure of the light-switching layer 31. The light-switching layer 31 may have a cross-sectional structure shown in FIG. 5, the light-controlling layer 31 includes one gap layer formed by a plurality of gaps 31D in contact with the first alignment layer 32, and one gap layer formed by a plurality of gaps 31D in contact with the second alignment layer 33. In each gap layer, a single gap 31D is arranged along the interface between the light-controlling layer 31 and each of the alignment layers 32, 33.

[0093] The gap layer in contact with the first alignment layer 32 includes at least one gap 31D that is in contact with any of the gaps 31D in the gap layer in contact with the second alignment layer 33. All of the gaps 31D included in the gap layer in contact with the first alignment layer 32 may be in contact with any of the gaps 31D included in the gap layer in contact with the second alignment layer 33.

[0094] In the gap layer in contact with the first alignment layer 32, the surface in contact with the first alignment layer 32 is the first surface, and the surface opposite to the first surface is the second surface. The second surface is a plane including the portion of the voids 31D contained in the gap layer that is the farthest from the first alignment layer 32. In the gap layer in contact with the second alignment layer 33, the surface in contact with the second alignment layer 33 is the first surface, and the surface opposite to the first surface is the second surface. The second surface is a plane including the portion of the voids 31D contained in the gap layer that is the farthest from the second alignment layer 33. It is preferable that the second surface of the gap layer in contact with the first alignment layer 32 and the second surface of the gap layer in contact with the second alignment layer 33 are the same surface.

[0095] The light-controlling sheet 21 includes a first high-density portion 31H1, a second high-density portion 31H2, and a low-density portion 31L. In the thickness direction of the light-controlling layer 31, the low-density portion 31L is sandwiched between the first high-density portion 31H1 and the second high-density portion 31H2. The low-density portion 31L includes a portion of the gap layer in contact with the first alignment layer 32 where the voids 31D are not located, and also includes a portion of the gap layer in contact with the second alignment layer 33 where the voids 31D are not located. Therefore, the density of the liquid crystal composition 31LC in the low-density portion 31L is lower than the density of the liquid crystal composition 31LC in the first high-density portion 31H1 and the density of the liquid crystal composition 31LC in the second high-density portion 31H2.

[0096] Also in the example shown in FIG. 5, in the light-controlling layer 31, the density of the liquid crystal composition 31LC is lowest at the middle of the light-controlling layer 31 in the thickness direction.

[0097] [Test example] A test example will be described with reference to FIGS. The light-control sheets of Test Examples 1-1 to 1-8 were obtained by the manufacturing method described below. [Test Example 1-1] A pair of PET substrates with ITO films formed thereon was prepared. The ITO films were 30 nm thick, and the PET substrates were 125 μm thick. A vertical alignment layer with a thickness of 100 nm was formed on each ITO film using a bar coater. Next, a coating liquid containing a polymerizable composition and liquid crystal molecules was applied to one of the vertical alignment layers. The other vertical alignment layer was then placed on the coating film, sandwiching the coating film between the pair of vertical alignment layers. The coating film was irradiated with ultraviolet light from both sides in the thickness direction of the coating film through the PET substrate, ITO film, and vertical alignment layer.

[0098] One factor that influences the quality of light-controlling sheets is the exposure process of the coating film, i.e., the light-controlling layer, during the production of the light-controlling sheet. More specifically, during the exposure process, the optimal exposure amount, or in other words, the optimal cumulative light amount, is determined in consideration of various conditions, such as the materials contained in the coating liquid and the thickness of the coating film. Here, the cumulative light amount is calculated by multiplying the illuminance of the irradiated ultraviolet light by the exposure time of the ultraviolet light. Each test example described below describes a light-controlling sheet obtained by appropriately changing the illuminance and exposure time to obtain the optimal cumulative light amount. Note that the thickness of the light-controlling layer of all light-controlling sheets shown in each test example was set to 7.0 μm.

[0099] In Test Example 1-1, the irradiance of ultraviolet light was 10 mW / cm 2 and the cumulative light intensity is set to 600mJ / cm 2 The coating film was irradiated with ultraviolet light so that [Test Example 1-2] In Test Example 1-1, the illuminance when irradiating the coating with ultraviolet light was 15 mW / cm 2 A light-controlling sheet of Test Example 1-2 was obtained in the same manner as in Test Example 1-1, except that the above-mentioned procedure was changed to the above.

[0100] [Test Example 1-3] In Test Example 1-1, the illuminance when irradiating the coating with ultraviolet light was 20 mW / cm 2 A light-controlling sheet of Test Example 3 was obtained in the same manner as in Test Example 1-1, except for changing the above.

[0101] [Test Example 1-4] In Test Example 1-1, the illuminance when irradiating the coating with ultraviolet light was 25 mW / cm 2 A light-controlling sheet of Test Example 1-4 was obtained in the same manner as in Test Example 1-1, except that the above-mentioned procedure was changed to the above.

[0102] [Test Example 1-5] In Test Example 1-1, the illuminance when irradiating the coating with ultraviolet light was 30 mW / cm 2 A light-controlling sheet of Test Example 1-5 was obtained in the same manner as in Test Example 1-1, except that the above-mentioned procedure was changed.

[0103] [Test Example 1-6] In Test Example 1-1, the illuminance when irradiating the coating with ultraviolet light was 35 mW / cm 2 A light-controlling sheet of Test Example 1-6 was obtained in the same manner as in Test Example 1-1, except that the above-mentioned procedure was changed.

[0104] [Test Example 1-7] In Test Example 1-1, the illuminance when irradiating the coating with ultraviolet light was 40 mW / cm 2 A light-controlling sheet of Test Example 1-7 was obtained in the same manner as in Test Example 1-1, except that the above-mentioned procedure was changed to the above.

[0105] [Test Example 1-8] In Test Example 1-1, the illuminance when irradiating the coating with ultraviolet light was 200 mW / cm 2 A light-controlling sheet of Test Example 1-8 was obtained in the same manner as in Test Example 1-1, except that the above-mentioned procedure was changed to the above.

[0106] [Evaluation method] [Gap size] The size of the voids was determined by observing the cross section of the resin layer using a scanning electron microscope. To determine the size of the voids, the liquid crystal composition containing liquid crystal molecules was first removed from the resin layer. A square test piece with a side length of 10 cm was cut out from each of the light-controlling sheets of Test Examples 1-1 to 1-8. The liquid crystal composition was then removed from the resin layer by immersing each test piece in isopropyl alcohol. The liquid crystal composition can also be removed from the test piece by immersing the test piece in an organic solvent that dissolves the liquid crystal composition but does not dissolve the resin layer.

[0107] Then, a scanning electron microscope was used to image the cross section of the test piece from which the liquid crystal composition had been removed. At this time, 30 rectangular regions were arbitrarily set on the cross section of the test piece. Images were then obtained for each region using the scanning electron microscope at a magnification of 1000 times. The 30 rectangular regions were set so that the distance between adjacent rectangular regions was 1 mm or more.

[0108] Ten voids were randomly selected in each image, and the size of each void was measured. The maximum and minimum values ​​of the sizes of the 10 voids were set as the maximum and minimum values ​​of the void size in that image. The maximum and minimum values ​​of the void size in each image were calculated. The maximum value of the maximum values ​​found in the 30 images was set as the maximum value of the void size in the test piece. In addition, the minimum value of the minimum values ​​found in the 30 images was set as the minimum value of the void size in the test piece.

[0109] For voids included in the image that were circular, the diameter of the void was set as the void size. For voids included in the image that were elliptical, the major axis of the void was set as the void size. For voids included in the image that were irregular, the diameter of the circle circumscribing the void was set as the void size.

[0110] [Formation range] In each of the images used to calculate the size of the voids, the boundary between the first alignment layer and the photochromic layer was used as a reference to calculate the void formation range, which is the range in the thickness direction of the photochromic layer. The maximum value of the formation ranges found in the 30 images was set as the void formation range for that test piece.

[0111] [Percentage of void area to low-density area SL] For each image used to calculate the size of the voids, the area SL of the low-density portion and the area of ​​each void were calculated. Then, for each image, the percentage ([SD / SL] × 100) of the sum SD of the void area relative to the area SL of the low-density portion was calculated. Then, for 30 images, the average value of the percentage of the sum of the void area relative to the area of ​​the low-density portion was calculated. This average value was set as the percentage of the sum of the void area relative to the area of ​​the low-density portion in each test piece. The area of ​​each void was calculated based on the number of pixels located within the area partitioned by the void in each image.

[0112] [Hayes] For each of the light-controlling sheets of Test Examples 1-1 to 1-8, the haze when opaque and when transparent were calculated. The haze calculation was performed using a method conforming to JIS K 7136:2000. For each light-controlling sheet, the state in which no potential difference was generated between the pair of transparent electrode layers, i.e., the state in which no AC voltage was applied between the pair of transparent electrodes, was defined as transparent. Furthermore, the state in which an AC voltage was applied between the pair of transparent electrode layers and the haze of the light-controlling sheet was saturated was defined as opaque.

[0113] [Clarity] The clarity when opaque was calculated for each of the light-controlling sheets of Test Examples 1-1 to 1-8. Clarity is calculated by dividing the light transmitted through the light-controlling layer 31 by the amount of light L that travels straight along the optical axis of the parallel light LP that entered the light-controlling layer 31. C The amount of narrow-angle scattered light whose angle with respect to the optical axis of the parallel light LP is within ±2.5° is defined as the light amount L R When the haze is calculated, the haze is calculated by the following formula (1): As in the case of calculating the haze, an AC voltage is applied between the pair of transparent electrode layers, and the state in which the haze of the light-control sheet is saturated is defined as the opaque state. 100×(L C -L R ) / (L C +L R ) … Formula (1)

[0114] [Linear transmittance] For each of the light-controlling sheets of Test Examples 1-1 to 1-8, the linear transmittance when opaque and the linear transmittance when transparent were calculated. For each light-controlling sheet, the state in which no potential difference occurs between the pair of transparent electrode layers, i.e., the state in which no AC voltage is applied between the pair of transparent electrodes, was defined as the transparent state. In addition, the state in which an AC voltage is applied between the pair of transparent electrode layers and the haze of the light-controlling sheet is saturated was defined as the opaque state.

[0115] [Evaluation results] The results of photographing the cross section of each test piece are shown in Figures 6 to 13. The evaluation results are shown in Tables 1 and 2 below. Figures 6 to 13 show SEM images of the cross sections of the light-control sheets of Test Examples 1-1 to 1-8, in order.

[0116] [Table 1]

[0117] [Table 2]

[0118] As shown in Figure 13, in the light-controlling sheet of Test Example 1-8, it was found that voids were formed almost uniformly throughout the entire thickness of the light-controlling sheet. In other words, it was found that the light-controlling sheet did not have high-density areas where the density of liquid crystal molecules was relatively high and low-density areas where the density of liquid crystal molecules was relatively low.

[0119] In contrast, as shown in Figures 6 to 12, in the light-control sheets of Test Examples 1-1 to 1-7, high-density areas were formed in the areas in contact with each alignment layer, and low-density areas were formed between the two high-density areas in the thickness direction of the light-control sheet. In particular, the light-control sheet of Test Example 1-7 had voids in the low-density areas, while the light-control sheets of Test Examples 1-1 to 1-6 did not have voids in the low-density areas.

[0120] It was found that the haze values ​​when transparent in the light controlling sheets of Test Examples 1-1 to 1-7 were significantly smaller than the haze value when transparent in the light controlling sheet of Test Example 1-8. Therefore, it can be said that by having high-density and low-density parts in the light controlling sheet, the haze value when transparent was reduced, that is, the transparency of the light controlling sheet 21 when transparent was improved.

[0121] As shown in Tables 1 and 2, the percentage of the total void area SD relative to the area SL of the low-density portion was 0% in Test Example 1-1, 0% in Test Example 1-2, and 0% in Test Example 1-3. Also, the percentage of the total void area SD relative to the area SL of the low-density portion was 0% in Test Example 1-4, 0% in Test Example 1-5, 0% in Test Example 1-6, and 8% in Test Example 1-7. In contrast, the percentage of the total void area relative to the area SL of the low-density portion was 11% in Test Example 1-8.

[0122] The haze values ​​when transparent in the light-controlling sheets of Test Examples 1-1 to 1-6 are further improved than the haze value when transparent in the light-controlling sheet of Test Example 1-7. Therefore, it can be said that the haze value when transparent is further improved by having the percentage of the sum SD of the void area relative to the area SL of the low-density portion be 10% or less.

[0123] Furthermore, in the light-controlling sheets of Test Example 1-1 to Test Example 1-7, the minimum void size was found to be 1.1 μm or more and 1.4 μm or less, and was found to be 1.0 μm or more. In contrast, in the light-controlling sheet of Test Example 1-8, the minimum void size was found to be 0.8 μm, and was found to be less than 1.0 μm. On the other hand, in the light-controlling sheets of Test Example 1-2 to Test Example 1-8, the maximum void size was found to be 1.5 μm or more and 2.4 μm or less, and was found to be 2.5 μm or less. In contrast, in the light-controlling sheet of Test Example 1-1, the maximum void size was found to be 2.7 μm, and was found to be greater than 2.5 μm.

[0124] In the light-control sheets of Test Examples 1-1 to 1-7, the minimum void size was 1.0 μm or more, so it can be said that the haze value was lower when transparent compared to the light-control sheet of Test Example 1-8, in which the minimum void size was less than 1.0 μm. On the other hand, in the light-control sheets of Test Examples 1-2 to 1-5, the maximum void size was 2.5 μm or less, so it can be said that the haze value when transparent was even lower compared to the light-control sheet of Test Example 1-1, in which the maximum void size was greater than 2.5 μm.

[0125] Furthermore, in Test Examples 1-1 to 1-5, it was observed that voids were formed within a range of 3.0 μm from the alignment layer. On the other hand, in Test Examples 1-6, 1-7, and 1-8, it was observed that voids were formed within a range of more than 3.0 μm from the alignment layer. Since Test Examples 1-1 to 1-5 had lower haze values ​​when transparent than Test Examples 1-6 and 1-7, it can be said that the formation of voids within a range of 3.0 μm from the alignment layer in Test Examples 1-1 to 1-5 is one of the factors that lower the haze values ​​when transparent.

[0126] In Test Examples 1-1 to 1-8, the thickness of the photochromic layer was set constant and the difference due to changing the exposure conditions was evaluated.In Test Examples 1-9 to 1-13 described below, the exposure conditions were set constant and the difference due to changing the thickness of the photochromic layer was evaluated.

[0127] [Test Example 1-9] In Test Example 1-9, a light-control layer having a thickness of 3.0 μm was formed by reducing the amount of coating liquid applied to the vertical alignment layer compared to Test Example 1-1. In all of the examples described below, the illuminance when irradiating the coating film with ultraviolet light was 20 mW / cm 2 , cumulative light intensity 600mJ / cm 2 was set to.

[0128] [Test Example 1-10] In Test Example 1-10, the light-controlling sheet of Test Example 1-10 was prepared in the same manner as Test Example 1-9, except that a light-controlling layer having a thickness of 7.0 μm was obtained by increasing the amount of coating liquid applied to the vertical alignment layer.

[0129] [Test Example 1-11] In Test Example 1-11, the light-controlling sheet of Test Example 1-11 was prepared in the same manner as Test Example 1-9, except that a light-controlling layer having a thickness of 8.0 μm was obtained by increasing the amount of coating liquid applied to the vertical alignment layer.

[0130] [Test Example 1-12] In Test Example 1-12, the light-controlling sheet of Test Example 1-12 was prepared in the same manner as Test Example 1-9, except that a light-controlling layer having a thickness of 10.0 μm was obtained by increasing the amount of coating liquid applied to the vertical alignment layer.

[0131] [Test Example 1-13] In Test Example 1-13, the light-controlling sheet of Test Example 1-13 was prepared in the same manner as Test Example 1-9, except that a light-controlling layer having a thickness of 16.0 μm was obtained by increasing the amount of coating liquid applied to the vertical alignment layer.

[0132] [Evaluation method] [image] The cross sections of the light controlling sheets of Test Examples 1-9 to 1-13 were imaged using the same method as that used to image the cross sections of the light controlling sheets of Test Examples 1-1 to 1-8.

[0133] [Gap size] The void size was calculated for the light-adjusting sheets of Test Examples 1-9 to 1-13 using the same method as that used to calculate the void size for the light-adjusting sheets of Test Examples 1-1 to 1-8. This allowed the minimum and maximum void size to be calculated for each light-adjusting sheet.

[0134] [Evaluation results] The results of imaging the cross sections of the light-adjusting sheets of Test Examples 1-9 to 1-13 are shown in Figures 14 to 18. Figures 14 to 18 show SEM images of the cross sections of the light-adjusting sheets of Test Examples 1-9 to 1-13, in order.

[0135] 14 to 16, when the thickness of the switchable layer is 3.0 μm or more and 8.0 μm or less, it was found that multiple voids were formed along the boundaries between each alignment layer and the switchable sheet. On the other hand, when the thickness of the switchable layer is 3.0 μm or more and 8.0 μm or less, it was found that no voids were formed in the center of the switchable layer in the thickness direction.

[0136] In contrast, as shown in Figure 17, when the thickness of the photochromic layer was 10.0 μm, it was observed that multiple voids were irregularly formed throughout the entire photochromic layer. That is, when the thickness of the photochromic layer was 10 μm, it was observed that the photochromic layer did not have high-density or low-density areas. Furthermore, as shown in Figure 18, when the thickness of the photochromic layer was 16.0 μm, it was observed that multiple voids were formed in the center of the photochromic layer in the thickness direction, with a density similar to the density of voids at the boundaries between each alignment layer and the photochromic sheet. It was also observed that multiple voids were formed between the voids located in the center and the voids located at the boundaries between the alignment layer and the photochromic layer in the thickness direction of the photochromic layer.

[0137] It was confirmed that the minimum and maximum void sizes in each light-controlling sheet were within the range of 1.0 μm or more and 2.5 μm or less. As described above, according to the second embodiment of the light controlling sheet, the following effects can be obtained.

[0138] (2-1) Because the density of the liquid crystal composition 31LC is high in regions that are close to the alignment layers 32 and 33, it is possible to increase the amount of liquid crystal molecules LCM that are aligned by the alignment restraining force of the alignment layers 32 and 33. Therefore, when no potential difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35, the transparency of the light control sheet 21 can be increased.

[0139] (2-2) Because the thickness T31 of the light-controlling layer 31 is 3.0 μm or more and 8.0 μm or less, the formation of voids 31D at positions away from a pair of opposing surfaces in the thickness direction of the light-controlling layer 31 is suppressed. Furthermore, because the size of the voids 31D is 1.0 μm or more and 2.5 μm or less, the liquid crystal composition 31LC is held in the vicinity of the alignment layers 32 and 33. This makes it possible to enhance the transparency of the light-controlling sheet 21 when no voltage difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35.

[0140] (2-3) In the light-controlling layer 31, the liquid crystal molecules LCM are aligned in accordance with the alignment restricting force of the alignment layers 32 and 33 in the vicinity of a pair of surfaces that face each other in the thickness direction of the light-controlling layer 31. Therefore, when no potential difference is generated between the first transparent electrode layer 34 and the second transparent electrode layer 35, the transparency of the light-controlling sheet 21 can be further improved.

[0141] (2-4) Since the density of the voids 31D in each high-density portion 31H1, 31H2 is higher than the density of the voids 31D in the low-density portion 31L, it is possible to make the density of the liquid crystal composition 31LC in each high-density portion 31H1, 31H2 higher than the density of the liquid crystal composition 31LC in the low-density portion 31L.

[0142] (2-5) Each void 31D included in the first high density portion 31H1 and each void 31D included in the second high density portion 31H2 are capable of holding the liquid crystal composition 31LC in the vicinity of the alignment layers 32, 33, so that the alignment control force of the alignment layers 32, 33 is more likely to act on the entire liquid crystal composition 31LC held in each void 31D.

[0143] (2-6) Since the percentage of the sum SD of the areas of the voids 31D contained in the low-density portion 31L relative to the area SL of the low-density portion 31L is 10% or less, it is possible to reduce the proportion of the liquid crystal composition 31LC held by the voids 31D of the low-density portion 31L.

[0144] (2-7) When the low-density portion 31L does not have a void 31D, the proportion of liquid crystal molecules LCM contained in the dimming layer 31 that are oriented in accordance with the orientation control force of the orientation layers 32, 33 is increased, thereby further increasing the transparency of the dimming sheet 21 when no voltage difference occurs between the first transparent electrode layer 34 and the second transparent electrode layer 35.

[0145] (2-8) In a cross section along the thickness direction of the dimming layer 31, the gaps 31D are located within a range of 3.0 μm or less from each alignment layer 32, 33, thereby increasing the reliability with which the liquid crystal molecules LCM held in each gap 31D are aligned in accordance with the alignment control force.

[0146] [Modification of the second embodiment] The second embodiment described above can be modified and implemented as follows. [Alignment layer] The light-controlling sheet 21 may include the first alignment layer 32 but may not include the second alignment layer 33. In this case, the light-controlling layer 31 may include the first high-density portion 31H1 and the low-density portion 31L, thereby achieving the effect equivalent to that described in (2-1) above.

[0147] When the light-controlling sheet 21 has a first alignment layer 32 but does not have a second alignment layer 33, the density of the voids 31D in the first high-density portion 31H1 is higher than the density of the voids 31D in the low-density portion 31L, and thus the effects related to the first high-density portion 31H1 among those mentioned above (2-5) can be obtained.

[0148] [Photochromic layer] The light-controlling layer 31 may have the lowest density of the liquid crystal composition 31LC at the middle of the thickness direction of the light-controlling layer 31, but may not have high-density portions 31H1 and 31H2 in contact with the alignment layers 32 and 33. That is, the high-density portions may be located in portions of the light-controlling layer 31 closer to the alignment layers 32 and 33 than the middle of the thickness direction of the light-controlling layer 31, but at positions farther from the alignment layers 32 and 33. Even in this case, the density of the liquid crystal composition 31LC being lowest at the middle of the thickness direction of the light-controlling layer 31 can provide the effect equivalent to the above-mentioned (2-1).

[0149] When the density of the liquid crystal composition 31LC is lowest at the middle of the thickness direction of the switchable layer 31 and the switchable layer 31 does not have high-density portions 31H1, 31H2 in contact with the alignment layers 32, 33, the void 31D may be located within 3.0 μm or less from the alignment layers 32, 33 in the cross section along the thickness direction of the switchable layer 31. In this case, it is possible to obtain the effects equivalent to those of (2-1) and (2-8) described above.

[0150] In the light-control sheet 21 having the light-control layer 31 with the high-density portions 31H1, 31H2 and the low-density portion 31L, the thickness of the light-control layer 31 may be at least twice the minimum size of the voids 31D and less than 10 μm, and the size of the voids 31D may be at least 0.38 μm and no more than 3.0 μm. In this case, the effects equivalent to those described in (2-1) and (2-2) above can be obtained.

[0151] In a light-controlling sheet 21 having a light-controlling layer 31 in which the density of the liquid crystal composition 31LC is lowest at the middle in the thickness direction of the light-controlling layer 31, the thickness of the light-controlling layer 31 may be at least twice the smallest value of the size of the voids 31D but less than 10 μm, and the size of the voids 31D may be at least 0.38 μm but not more than 3.0 μm. In this case, the effects equivalent to those described in (2-1) and (2-2) above can be obtained.

[0152] [Third embodiment] A third embodiment of the light controlling sheet will be described with reference to FIGS. [Light-adjusting sheet] 19, the light controlling sheet 110 has a first surface 111F and a second surface 111R that is the surface opposite to the first surface 111F. When viewed from a position facing the first surface 111F, the light controlling sheet 110 has a driving region 120, a non-driving region 121, and a connection region 124.

[0153] The driving region 120 is an area where driving electrode elements 130 are located, which are electrode elements to which a voltage signal is applied when the light controlling sheet 110 is driven. The light transmittance of the driving region 120 changes depending on the state of application of the voltage signal to the driving electrode elements 130. The driving electrode elements 130 are an example of a first electrode element.

[0154] The non-driving region 121 includes a floating region 122, which is a region where floating electrode elements 131, which are electrode elements to which no voltage signal is applied when the light controlling sheet 110 is driven, are located, and a boundary region 123 that surrounds the floating region 122. The floating electrode elements 131 are an example of a second electrode element. The boundary region 123 is located between the driving region 120 and the floating region 122, and has a closed frame shape that surrounds the floating region 122. No electrode elements are located in the boundary region 123. Note that the width of the boundary region 123 is exaggerated in the drawings for ease of understanding. The light transmittance of the non-driving region 121 does not change whether the light controlling sheet 110 is driven or not.

[0155] The floating areas 122 form a pattern, and by making the floating areas 122 visible, the pattern is displayed on the light controlling sheet 110. The pattern is, for example, one of letters, numbers, symbols, figures, pictures, and patterns, or a combination thereof. The light controlling sheet 110 may have multiple floating areas 122 that are separated from each other, that is, multiple non-driven areas 121 that are separated from each other.

[0156] The connection region 124 is a region to which wiring for applying a voltage signal to the driving region 120 is connected. The connection region 124 includes a first connection region 124A and a second connection region 124B. A first terminal portion 135A is provided in the first connection region 124A, and a second terminal portion 135B is provided in the second connection region 124B. Each of the connection regions 124A and 124B is adjacent to the driving region 120 and is located at an end of the light controlling sheet 110, for example.

[0157] 20 is a cross-sectional view taken along line I-I in FIG. 19, showing the cross-sectional structure of the light controlling sheet 110 in the drive region 120 and the connection region 124. For ease of illustration, the antiviral film provided on the light controlling sheet 110 is omitted from FIG. 20. The light controlling sheet 110 of the third embodiment can include the antiviral film provided on the light controlling sheet of the first embodiment, and the antiviral film or antiviral layer described in the modified example of the first embodiment.

[0158] 20, the light-controlling sheet 110 has a light-controlling layer 140, a first transparent electrode layer 141A, a second transparent electrode layer 141B, a first transparent support layer 142A, a second transparent support layer 142B, and a cover layer 145. The light-controlling layer 140 is sandwiched between the first transparent electrode layer 141A and the second transparent electrode layer 141B and is in contact with these transparent electrode layers 141A and 141B. The first transparent support layer 142A supports the first transparent electrode layer 141A on the side opposite the light-controlling layer 140 with respect to the first transparent electrode layer 141A, and the second transparent support layer 142B supports the second transparent electrode layer 141B on the side opposite the light-controlling layer 140 with respect to the second transparent electrode layer 141B.

[0159] The above-described driving electrode elements 130 and floating electrode elements 131 are included in the first transparent electrode layer 141A. The portions of the first transparent electrode layer 141A located in the driving region 120 are the driving electrode elements 130. Of the two surfaces of the first transparent support layer 142A, the surface that contacts the first transparent electrode layer 141A and supports the first transparent electrode layer 141A is the supporting surface 146S, and the surface opposite to the supporting surface 146S is the protected surface 146P.

[0160] The covering layer 145 is located on the opposite side of the first transparent support layer 142A from the first transparent electrode layer 141A. The covering layer 145 includes an adhesive layer 143 and a protective layer 144. The adhesive layer 143 is in contact with the protected surface 146P of the first transparent support layer 142A. The protective layer 144 is in contact with the adhesive layer 143 on the opposite side of the adhesive layer 143 from the first transparent support layer 142A. When the light controlling sheet 110 includes an antiviral film, the light controlling sheet 110 may include an antiviral film instead of the covering layer 145. Alternatively, the light controlling sheet 110 may include an antiviral film on the covering layer 145. In this case, the adhesive layer of the antiviral film is in contact with the covering layer 145.

[0161] The first surface 111F of the light controlling sheet 110 is a surface of the covering layer 145, specifically, the surface opposite the surface of the protective layer 144 that contacts the adhesive layer 143. The second surface 111R of the light controlling sheet 110 is the surface of the second transparent support layer 142B that is opposite the surface that contacts the second transparent electrode layer 141B. The second surface 111R is attached to a transparent plate made of glass, resin, or the like via an adhesive layer. Examples of transparent plates include windowpanes in various buildings such as homes, stations, and airports; partitions installed in offices, medical institutions, and nursing homes; show windows installed in stores; and windowpanes and windshields in moving objects such as vehicles and aircraft. The surface of the transparent plate may be flat or curved. Note that if the light controlling sheet 110 includes an antiviral film, the adhesive layer of the antiviral film is located on the second surface 111R of the light controlling sheet 110, and the antiviral film is attached to the transparent plate.

[0162] In the first connection region 124A, a first transparent electrode layer 141A supported by a first transparent support layer 142A extends from the driving region 120, and in the first connection region 124A, the first transparent electrode layer 141A is exposed from the light control layer 140. A first terminal portion 135A is connected to this exposed first transparent electrode layer 141A. In other words, the driving electrode element 130 extends from the driving region 120 to the first connection region 124A, and in the first connection region 124A, the first terminal portion 135A is connected to the driving electrode element 130.

[0163] In the second connection region 124B, the second transparent electrode layer 141B and the second transparent support layer 142B extend from the driving region 120, and in the second connection region 124B, the second transparent electrode layer 141B is exposed from the light control layer 140. The second terminal portion 135B is connected to this exposed second transparent electrode layer 141B.

[0164] A first wiring section 150A extends from the first terminal section 135A, and a second wiring section 150B extends from the second terminal section 135B. These wiring sections 150A and 150B are connected to a control section 151. The control section 151 applies a voltage signal to the driving electrode element 130 of the first transparent electrode layer 141A through the first wiring section 150A and the first terminal section 135A, and applies a voltage signal to the second transparent electrode layer 141B through the second wiring section 150B and the second terminal section 135B. In this way, the control section 151 controls the potential difference between the first transparent electrode layer 141A and the second transparent electrode layer 141B in the driving region 120. The second transparent electrode layer 141B is controlled to, for example, ground potential. The light control sheet 110 and the control section 151 constitute a light control device.

[0165] The light-controlling layer 140 includes a transparent polymer layer and a liquid crystal composition. The transparent polymer layer has voids, and the voids are filled with a liquid crystal composition. The liquid crystal composition contains liquid crystal molecules. Any of the liquid crystal molecules listed in the first embodiment can be used as the liquid crystal molecules.

[0166] The retention type of the liquid crystal composition in the light control layer 140 may be any of the retention types listed in the first embodiment. Note that, like the liquid crystal composition of the first embodiment, the liquid crystal composition may contain, in addition to the above-mentioned liquid crystal molecules, a monomer for forming a transparent polymer layer, a dichroic dye, and the like.

[0167] Each of the first transparent electrode layer 141A and the second transparent electrode layer 141B is conductive and transparent to light in the visible region. The material of the transparent electrode layers 141A and 141B may be any of the materials listed in the first embodiment.

[0168] Each of the first transparent support layer 142A and the second transparent support layer 142B is a substrate that is transparent to light in the visible region. The material of the transparent support layers 142A and 142B may be any of the materials listed in the first embodiment.

[0169] The adhesive layer 143 is a layer that is transparent to light in the visible region and is made of a resin that has adhesiveness and insulating properties. The adhesive layer 143 is made of an optical clear adhesive (OCA).

[0170] The protective layer 144 is a layer that is transparent to light in the visible region. The material of the protective layer 144 is, for example, a synthetic resin such as polyethylene terephthalate, polyethylene naphthalate, polymethyl methacrylate, polycarbonate, polyolefin, or triacetyl cellulose. The protective layer 144 may have an anti-reflection function.

[0171] Each of the first terminal 135A and the second terminal 135B includes, for example, a conductive adhesive layer and a wiring substrate. The conductive adhesive layer may be any of the adhesive layers listed in the first embodiment. The wiring substrate is, for example, a flexible printed circuit (FPC), similar to the wiring substrate of the first embodiment.

[0172] Alternatively, each of the first terminal portion 135A and the second terminal portion 135B may have a structure in which a conductive material such as a conductive tape and a conductor are joined by soldering. In the driving region 120, the light-controlling layer 140 changes the orientation of the liquid crystal molecules in response to a change in the voltage generated between the two transparent electrode layers 141A, 141B. The change in orientation of the liquid crystal molecules changes the degree of scattering, absorption, and transmission of visible light that enters the light-controlling layer 140.

[0173] Specifically, when no voltage signal is applied to the transparent electrode layers 141A and 141B, the orientation of the long axis direction of the liquid crystal molecules is irregular. As a result, the degree of scattering of light incident on the light-controlling layer 140 increases, and the driving region 120 appears cloudy. In other words, when no driving voltage is applied to the light-controlling layer 140, the driving region 120 is opaque. On the other hand, when a voltage signal is applied to the transparent electrode layers 141A and 141B and a potential difference of a predetermined value or greater occurs between the first transparent electrode layer 141A and the second transparent electrode layer 141B, the liquid crystal molecules are oriented, and the long axis direction of the liquid crystal molecules is aligned with the electric field direction between the transparent electrode layers 141A and 141B. As a result, light is more easily transmitted through the light-controlling layer 140, and the driving region 120 becomes transparent.

[0174] 21 is a cross-sectional view taken along line II-II in FIG. 19, showing the cross-sectional structure of the light controlling sheet 110 in the boundary region 123 and the driving region 120 and floating region 122 sandwiching the boundary region 123. FIG.

[0175] 21, in the first transparent electrode layer 141A, the driving electrode elements 130 are located in the driving region 120, and the floating electrode elements 131 are located in the floating region 122. In other words, the driving electrode elements 130 and the floating electrode elements 131 are separate layer bodies aligned along the support surface 146S.

[0176] The driving electrode element 130 and the floating electrode element 131 are separated by a groove 132. The depth direction of the groove 132 is the thickness direction of the first transparent electrode layer 141A, and the groove 132 penetrates the first transparent support layer 142A and the first transparent electrode layer 141A in the depth direction. Separation by the groove 132 means that the driving electrode element 130 and the floating electrode element 131 are insulated from each other.

[0177] When viewed from a position facing the first surface 111F of the light controlling sheet 110, the region where the grooves 132 are located is the boundary region 123. As described above, the boundary region 123 has a closed frame shape that surrounds the floating region 122, that is, the grooves 132 extend in a direction along the support surface 146S and have a closed frame shape that surrounds the entire periphery of the floating electrode elements 131 when viewed from a position facing the first surface 111F. No wiring for applying a voltage signal is connected to the floating electrode elements 131, and therefore the floating electrode elements 131 are in an electrically floating state.

[0178] Therefore, the degree of scattering of light incident on the switchable layer 140 is always large in the floating region 122. Furthermore, since no electrode elements are located on the first transparent electrode layer 141A in the boundary region 123, the degree of scattering of light incident on the switchable layer 140 is always large even in the boundary region 123. Therefore, the non-driving region 121 always appears cloudy.

[0179] The groove 132 has an opening 133 on the surface 146P to be protected of the first transparent support layer 142A. The opening 133 is covered with an adhesive layer 143 of the covering layer 145. Furthermore, an adhesive portion 147 that is continuous with the adhesive layer 143 extends into the groove 132, and the groove 132 is filled with the adhesive portion 147. The adhesive portion 147 is made of the same material as the adhesive layer 143. The adhesive portion 147 is an example of a filling portion.

[0180] Filling the grooves 132 with the insulating adhesive portions 147 improves the reliability of insulation between the drive electrode elements 130 and the floating electrode elements 131. The adhesive that constitutes the adhesive layer 143 and the adhesive portions 147 is a material that easily ensures fluidity and flexibility during manufacturing, and therefore can accurately fill the grooves 132. Furthermore, because the protective layer 144 is laminated on the adhesive layer 143, adhesion of dust to the first surface 111F of the light controlling sheet 110 is suppressed compared to when the adhesive layer 143 is exposed, and the light controlling sheet 110 is easier to handle.

[0181] Furthermore, by filling the grooves 132 with the adhesive portions 147, the grooves 132 are prevented from being conspicuous, that is, the boundary regions 123 are prevented from being conspicuous, when viewed from a position facing the first surface 111F of the light controlling sheet 110. Furthermore, by covering the openings 133 of the grooves 132 with the adhesive layer 143 and the protective layer 144, the grooves 132 are further prevented from being conspicuous.

[0182] To more suitably prevent grooves 132 from being conspicuous, it is preferable that the refractive indices of first transparent electrode layer 141A, first transparent support layer 142A, adhesive layer 143 and adhesive portion 147, and protective layer 144 are close to each other. The smaller the difference between these refractive indices, the more the reflection and refraction of light in the vicinity of grooves 132 is suppressed, making grooves 132 less visible.

[0183] For example, the refractive index of indium tin oxide, which is widely used for first transparent electrode layer 141A, is approximately 2.1 to 2.2, and the refractive index of polyethylene terephthalate or acrylic resin, which is widely used for first transparent support layer 142A, is approximately 1.4 to 1.5. Therefore, the refractive index of the adhesive that forms adhesive layer 143 and adhesive portion 147 is preferably 1.4 or more and 1.5 or less, and the refractive index of protective layer 144 is preferably 1.4 or more and 1.6 or less.

[0184] The grooves 132 may extend in the depth direction into the switchable layer 140. For example, as shown in Fig. 22, the grooves 132 may penetrate the switchable layer 140, or the bottoms of the grooves 132 may be located inside the switchable layer 140. Furthermore, for example, as shown in Fig. 23, the grooves 132 may penetrate the switchable layer 140 and the second transparent electrode layer 141B.

[0185] If the grooves 132 extend to the inside of the light-controlling layer 140, the reliability of insulation between the driving electrode elements 130 and the floating electrode elements 131 can be increased. Furthermore, in a configuration in which the groove 132 penetrates the second transparent electrode layer 141B, the portion of the second transparent electrode layer 141B located in the floating region 122 is insulated from the surroundings, and no voltage signal is applied to this portion. Therefore, regardless of the potential of the second transparent electrode layer 141B in the driving region 120, the formation of a potential difference between the first transparent electrode layer 141A and the second transparent electrode layer 141B in the floating region 122 is suppressed. In other words, regardless of the magnitude of the voltage signal applied to the second transparent electrode layer 141B in the driving region 120 or the state of its fluctuation, the orientation state of the liquid crystal molecules of the dimming layer 140 in the floating region 122 does not change. Therefore, the degree of freedom in controlling the potential of the second transparent electrode layer 141B in the driving region 120 is increased.

[0186] The width of groove 132 in the depth direction may or may not be constant. For example, the width of groove 132 may become smaller toward the bottom of the groove. In other words, groove 132 may have a V-shaped cross section. If groove 132 has a V-shaped cross section, it is easy to fill groove 132 by flowing adhesive into groove 132.

[0187] To prevent the grooves 132 from being conspicuous when viewed from a position facing the first surface 111F of the light controlling sheet 110, the width of the grooves 132 at the openings 133 is preferably 1 mm or less, and more preferably 0.5 mm or less.

[0188] [Light control sheet manufacturing method] A method for manufacturing the light controlling sheet 110 will be described with reference to FIGS. 24, first, a light control layer 140 is formed between a first transparent electrode layer 141A supported by a first transparent support layer 142A and a second transparent electrode layer 141B supported by a second transparent support layer 142B, thereby forming a stacked body 160 consisting of the light control layer 140, the transparent electrode layers 141A and 141B, and the transparent support layers 142A and 142B. At this point, the first transparent electrode layer 141A is a uniform layer that is not divided into the driving electrode elements 130 and the floating electrode elements 131.

[0189] 25, grooves 132 are formed in the laminate 160 from the outside of the laminate 160. In detail, grooves 132 are formed by making cuts in the laminate 160 from the side where the first transparent support layer 142A is located relative to the light-controlling layer 140. To form the grooves 132, a cutting device such as a cutting plotter or a laser cutter is used.

[0190] 26, an adhesive is placed on first transparent support layer 142A in laminate 160, thereby forming adhesive layer 143 and adhesive portion 147. Groove 132 is filled with adhesive portion 147. Then, protective layer 144 is attached to adhesive layer 143, as shown in FIG.

[0191] The adhesive layer 143 and the adhesive portion 147 may be formed by attaching a film-like adhesive such as an OCA film to the laminate 160, or by applying a flowable adhesive to the laminate 160. Even when the adhesive is in film form, the film made of this adhesive is flexible, so that the adhesive can fill the grooves 132. Furthermore, heating and pressure may be applied when forming the adhesive layer 143 and the adhesive portion 147 and when laminating the protective layer 144.

[0192] In addition, instead of placing an adhesive on the laminate 160, an adhesive may be placed on the surface of the protective layer 144 to form an adhesive layer 143, and the protective layer 144 and the adhesive layer 143 may be attached to the laminate 160.

[0193] The connection region 124 is formed by cutting out a part of the constituent layers from the laminate 160. The connection region 124 may be formed in the same process as the formation of the grooves 132, or may be formed after the adhesive layer 143 and the protective layer 144 are laminated onto the laminate 160. If the connection region 124 is formed in the same process as the formation of the grooves 132, the number of processes and time required to manufacture the light controlling sheet 110 can be reduced.

[0194] Since the first transparent electrode layer 141A is very thin compared to the light-controlling layer 140, forming the grooves 132 so that the bottoms of the grooves 132 are located within the light-controlling layer 140 reduces the burden required to control the depth of the grooves 132, compared to forming the grooves 132 so that they penetrate the first transparent electrode layer 141A but do not enter the light-controlling layer 140. Therefore, if the bottoms of the grooves 132 are located within the light-controlling layer 140, it is possible to increase the reliability of insulation between the driving electrode elements 130 and the floating electrode elements 131 while suppressing an increase in the burden required for manufacturing.

[0195] As described above, in this embodiment, the grooves 132 for insulating the driving electrode elements 130 and the floating electrode elements 131 are formed by making cuts from the outside into the laminate 160 made up of the transparent electrode layers 141A, 141B, the transparent support layers 142A, 142B, and the light control layer 140 after these layers are laminated together. Therefore, compared to dividing the electrode elements using etching or the like before forming the laminate 160, it is possible to reduce the number of steps and time required to separate the driving electrode elements 130 and the floating electrode elements 131 and simplify the equipment. In addition, the degree of freedom in the shapes of the driving electrode elements 130 and the floating electrode elements 131 is increased, and further, it is possible to easily accommodate design changes in the shapes of the driving electrode elements 130 and the floating electrode elements 131.

[0196] [Effect] FIG. 28 schematically shows the degree of transparency of the light controlling sheet 110 when the light controlling sheet 110 is not driven, that is, when no voltage signal is applied to the transparent electrode layers 141A and 141B.

[0197] 28, when the light controlling sheet 110 is not driven, both the driving region 120 and the floating region 122 are opaque. Therefore, the entire surface of the light controlling sheet 110 appears whitish or cloudy, for example, and images such as letters and pictures formed in the floating region 122 cannot be seen.

[0198] In contrast, when the light controlling sheet 110 is driven, that is, when a voltage signal is applied to the transparent electrode layers 141A and 141B, the driving region 120 becomes transparent, while the floating region 122 is opaque. Therefore, as shown in Fig. 19 above, only the floating region 122 appears, for example, whitish or cloudy, and images such as letters and pictures that are made up of the floating region 122 become visible.

[0199] As described above, with the light controlling sheet 110 of this embodiment, regions with different light transmittances are formed within the surface of the light controlling sheet 110, and the difference in light transmittance between these regions only appears when the light controlling sheet 110 is driven. Therefore, when the light controlling sheet 110 is driven, images such as letters and pictures formed by the floating area 122 are visible, making it possible to decorate the space in which the light controlling sheet 110 is placed. Furthermore, by switching between driving and non-driving the light controlling sheet 110, it is possible to switch whether or not the above images appear, thereby dynamically changing the decorative state of the space. This makes it possible to improve the design of the light controlling sheet 110.

[0200] Note that if the light-adjusting layer 140 is present in the boundary region 123, the boundary region 123 is always opaque. Therefore, when the light-adjusting sheet 110 is not driven, both the driving region 120 and the non-driving region 121 appear opaque, and when the light-adjusting sheet 110 is driven, the non-driving region 121 appears opaque as a unit. On the other hand, if the grooves 132 separating the driving electrode elements 130 and the floating electrode elements 131 penetrate the light-adjusting layer 140 and the light-adjusting layer 140 is not present in the boundary region 123, the boundary region 123 is always transparent. Therefore, when the light-adjusting sheet 110 is not driven, the driving region 120 and the floating region 122 are opaque, while the boundary region 123 is transparent. However, because the boundary region 123 is thin and linear, it is not very noticeable, and images such as letters and pictures that make up the floating region 122 are not easily visible. When the light-adjusting sheet 110 is driven, the boundary region 123 appears transparent as a unit with the driving region 120.

[0201] To prevent the boundary region 123 from being noticeable when the light-adjusting sheet 110 is not driven, it is preferable that the grooves 132 do not penetrate the light-adjusting layer 140, and that at least a portion of the light-adjusting layer 140 is present in the thickness direction in the boundary region 123. Alternatively, as part of the design of the light-adjusting sheet 110, the boundary region 123 may be made more noticeable so that the border-shaped boundary region 123 is visible when the light-adjusting sheet 110 is not driven. In this case, the light-adjusting layer 140 does not need to be present in the boundary region 123, and the width of the boundary region 123 may be increased.

[0202] As described above, according to the third embodiment of the light controlling sheet, the following effects can be obtained. (3-1) By controlling the application of voltage signals to the driving electrode elements 130 and the floating electrode elements 131, it is possible to change the difference in light transmittance between the driving region 120 and the floating region 122, thereby changing the visibility of the image formed by the floating region 122. Therefore, it is possible to dynamically change the decorative state of the space created by the light controlling sheet 110, and it is possible to improve the design of the light controlling sheet 110.

[0203] (3-2) Grooves 132 for insulating the driving electrode elements 130 and the floating electrode elements 131 extend through the first transparent support layer 142A and the first transparent electrode layer 141A. This structure can be formed by making cuts from the surface of the first transparent support layer 142A into the first transparent support layer 142A and the first transparent electrode layer 141A after laminating the transparent electrode layers 141A, 141B and the transparent support layers 142A, 142B with the light control layer 140. This makes it easy to separate the driving electrode elements 130 and the floating electrode elements 131. This also increases the degree of freedom in the shapes of the driving electrode elements 130 and the floating electrode elements 131, and further makes it easy to accommodate design changes in the shapes of the driving electrode elements 130 and the floating electrode elements 131.

[0204] (3-3) Because the openings 133 of the grooves 132 are covered with the covering layer 145, it is possible to prevent a conductive material from entering the grooves 132 and causing electrical conduction between the driving electrode elements 130 and the floating electrode elements 131. In addition, it is possible to prevent the grooves 132 from being noticeable when viewed from the first surface 111F of the light control sheet 110.

[0205] (3-4) Because the grooves 132 are filled with filling portions that extend continuously from the covering layer 145, the reliability of insulation between the driving electrode elements 130 and the floating electrode elements 131 is improved. Furthermore, the covering layer 145 includes an adhesive layer 143 and a protective layer 144, and the filling portions are adhesive portions 147 that extend from the adhesive layer 143. In other words, because the grooves 132 are filled with an adhesive that has flexibility and fluidity, the grooves 132 can be easily filled. Furthermore, because the protective layer 144 is laminated on the adhesive layer 143, adhesion of dust and the like to the adhesive layer 143 is suppressed, and the light control sheet 110 becomes easier to handle.

[0206] (3-5) When the refractive index of the layer included in covering layer 145 is 1.4 or more and 1.6 or less, the refractive index of covering layer 145 is greater than that of air, which tends to reduce the difference in refractive index between first transparent support layer 142A and covering layer 145. Therefore, compared to when grooves 132 are exposed to air, the difference in refractive index at the interface near grooves 132 is smaller, and light reflection and refraction are suppressed, making grooves 132 less noticeable.

[0207] (3-6) If the grooves 132 extend to the inside of the light-controlling layer 140 in the depth direction of the grooves 132, the reliability of insulation between the driving electrode elements 130 and the floating electrode elements 131 is increased.

[0208] (3-7) In a configuration in which the grooves 132 penetrate the light-controlling layer 140 and the second transparent electrode layer 141B in the depth direction of the grooves 132, the second transparent electrode layer 141B is also divided into a plurality of parts insulated from each other in correspondence with the driving electrode elements 130 and the floating electrode elements 131. Therefore, the potential difference between the first transparent electrode layer 141A and the second transparent electrode layer 141B can be precisely controlled for each divided region. Therefore, the light transmittance of the region where each electrode element 130, 131 is located can be precisely controlled.

[0209] (3-8) When viewed from a position facing the first surface 111F, the grooves 132 have a closed frame shape that surrounds the floating electrode elements 131. This makes it easy to insulate the driving electrode elements 130 from the floating electrode elements 131 so that the floating areas 122 form letters, numbers, symbols, figures, designs, and the like, and also increases the degree of freedom in the arrangement and shape of the floating electrode elements 131. This increases the degree of freedom in the configuration of the image that appears on the light control sheet 110.

[0210] (3-9) Of the driving electrode element 130 and the floating electrode element 131, only the driving electrode element 130 is connected to the terminal portions 135A and 135B. This makes it possible to switch between a state in which there is no difference in light transmittance between the driving region 120 and the floating region 122 and a state in which there is a difference in light transmittance between the driving region 120 and the floating region 122, depending on whether or not a voltage signal is applied to the driving electrode element 130. Therefore, the design of the light control sheet can be improved with a simple configuration.

[0211] [Modification of the third embodiment] The third embodiment described above can be modified as follows: The following modifications may also be combined with each other.

[0212] 29, the light control sheet 110 may include a first alignment layer 148A and a second alignment layer 148B. The first alignment layer 148A is located between the light control layer 140 and the first transparent electrode layer 141A and is in contact with these layers. The second alignment layer 148B is located between the light control layer 140 and the second transparent electrode layer 141B and is in contact with these layers.

[0213] Each of the first alignment layer 148A and the second alignment layer 148B 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 140. The material of each of the first alignment layer 148A and the second alignment layer 148B may be any of the materials listed in the first embodiment.

[0214] When the light-controlling sheet 110 includes the alignment layers 148A and 148B, in the driving region 120, when no voltage signal is applied to the transparent electrode layers 141A and 141B, the long axis direction of the liquid crystal molecules is oriented along the thickness direction of the light-controlling layer 140. Therefore, the driving region 120 is transparent. On the other hand, when a voltage signal is applied to the transparent electrode layers 141A and 141B in the driving region 120, the long axis direction of the liquid crystal molecules is oriented to intersect with the thickness direction of the light-controlling layer 140. Therefore, the driving region 120 appears cloudy and opaque.

[0215] When the light-controlling sheet 110 has alignment layers 148A and 148B, the floating region 122 is always transparent because the long axis direction of the liquid crystal molecules is always oriented along the thickness direction of the light-controlling layer 140.

[0216] Therefore, when the light adjusting sheet 110 is not driven, both the driving region 120 and the floating region 122 are transparent, and images such as letters and patterns formed in the floating region 122 are not visible. On the other hand, when the light adjusting sheet 110 is driven, the driving region 120 becomes opaque, but the floating region 122 is transparent, so images such as letters and patterns formed in the floating region 122 become visible.

[0217] As in the above embodiment, the grooves 132 for separating the driving electrode elements 130 and the floating electrode elements 131 need only penetrate at least the first transparent support layer 142A and the first transparent electrode layer 141A. The grooves 132 may also penetrate part or all of the first alignment layer 148A, the light control layer 140, the second alignment layer 148B, and the second transparent electrode layer 141B.

[0218] When the grooves 132 do not penetrate the first alignment layer 148A, or when the grooves 132 penetrate the light-controlling layer 140, the boundary region 123 is always transparent and appears to be integrated with the floating region 122. Therefore, in order to prevent the boundary region 123 from being noticeable when the light-controlling sheet 110 is not driven, it is preferable that the grooves 132 do not penetrate the first alignment layer 148A or extend to a position where they penetrate the light-controlling layer 140.

[0219] As described above, even when the light controlling sheet 110 includes the alignment layers 148A and 148B, the driving region 120 and the floating region 122 exist within the plane of the light controlling sheet 110, and these are regions where a difference in light transmittance appears only when the light controlling sheet 110 is driven. This makes it possible to improve the design of the light controlling sheet 110.

[0220] The protective layer 144 may have a lower light transmittance than the first transparent support layer 142A. For example, the protective layer 144 may be a half-mirror film or a colored film such as a smoked film. If the protective layer 144 has a lower light transmittance than the first transparent support layer 142A, the appearance of the light-controlling sheet 110 changes depending on the intensity of the light source behind the light-controlling sheet 110. For example, if the protective layer 144 is a half-mirror film, when the light source behind the light-controlling sheet 110 is weak, the first surface 111F of the light-controlling sheet 110 appears as a mirror. Alternatively, if the protective layer 144 is a smoked film, when the light source behind the light-controlling sheet 110 is weak, the light-controlling sheet 110 appears as a dark color such as black. This allows the light-controlling sheet 110 to decorate a space in a more diverse manner, further improving the design of the light-controlling sheet 110.

[0221] There are no particular limitations on the number of layers or materials included in the covering layer 145. The covering layer 145 may include only one of the adhesive layer 143 and the protective layer 144, or may include a layer different from the adhesive layer 143 and the protective layer 144. As long as the covering layer 145 covers the opening 133 of the groove 132, the effect of preventing conductive materials from entering the groove 132 can be obtained.

[0222] Furthermore, the filling portion that fills groove 132 may be made of a material other than an adhesive. For example, a thermosetting resin or photocurable resin used as a hard coating material may be applied to first transparent support layer 142A in which groove 132 is formed, and the applied resin may be cured by heat or light to form the filling portion and covering layer 145. In this case, the filling portion and covering layer 145 are made of a curable resin, and the filling portion extends continuously from covering layer 145 into groove 132.

[0223] Even if the materials of the filling portion and the covering layer 145 are different from those in the above embodiment, in order to prevent the groove 132 from being noticeable, it is preferable that the refractive index of the layers included in the filling portion and the covering layer 145 be 1.4 or more and 1.6 or less. As long as opening 133 of groove 132 is covered with covering layer 145, groove 132 does not have to be partially or entirely filled with the filling portion.

[0224] The cover layer 145 may include a layer that is ultraviolet absorbing. For example, at least one of the adhesive layer 143 and the protective layer 144 may be ultraviolet absorbing. With this configuration, ultraviolet light contained in sunlight or the like irradiated onto the light controlling sheet 110 is absorbed by the cover layer 145 and is less likely to reach the light controlling layer 140. This prevents the deterioration of the function of the liquid crystal composition.

[0225] The grooves 132 located in the boundary region 123 do not have to form a closed frame surrounding the floating electrode elements 131, as long as they extend in a direction along the support surface 146S of the first transparent support layer 142A. For example, as shown in Figure 30, when viewed from a position facing the first surface 111F, the boundary region 123 and grooves 132 may extend from a starting point located at the edge 110E of the light controlling sheet 110, through the periphery of the floating region 122 and floating electrode elements 131, to an ending point located at the edge 110E of the light controlling sheet 110. In this case, the ends of the floating region 122 and floating electrode elements 131 are located at the edge 110E of the light controlling sheet 110. In Figure 30, the lower side of the rectangular light-adjusting sheet 110 is shown as the end 110E, but the end 110E where the starting and ending points of the boundary region 123 and groove 132 are located may be any of the upper side, left side, or right side, or may be multiple of these sides.

[0226] In the above embodiment, a voltage signal is applied to the driving electrode element 130, which is the first electrode element, and no voltage signal is applied to the floating electrode element 131, which is the second electrode element. Alternatively, voltage signals may be applied separately to the first electrode element and the second electrode element. Wiring for applying a voltage signal to the second electrode element is connected to the end of the second electrode element through a terminal portion. 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. As described above, if the second electrode element is located at the end of the light controlling sheet 110, it is easy to connect wiring to the second electrode element.

[0227] For example, the first region where the first electrode elements are located can be switched between transparent and opaque by switching the state of a voltage signal applied 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 a voltage signal applied to the second electrode elements. This configuration allows switching between four states: a state where both the first and second regions are opaque, a state where the first region is opaque and the second region is transparent, a state where the first region is transparent and the second region is opaque, and a state where both the first and second regions are opaque. This allows the decorative state of the space created by the light controlling sheet 110 to be varied in a more diverse manner, further improving the design of the light controlling sheet 110.

[0228] Alternatively, for example, the light transmittance of at least one of the first and second regions may be controlled to a light transmittance corresponding to a value between transparency and opacity. In a light-controlling sheet 110 including a light-controlling layer 140 containing a liquid crystal composition, when the potential difference between the transparent electrode layers 141A and 141B is within a predetermined range, the light transmittance of the light-controlling sheet 110 gradually changes as the potential difference changes. Therefore, by controlling the potential difference between the transparent electrode layers 141A and 141B in the first or second region to a value between the potential difference at which the region becomes transparent and the potential difference at which the region becomes opaque, the region can be controlled to be translucent, with a light transmittance between transparency and opaque.

[0229] 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, and 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. When the first region is transparent, the second region is controlled to be translucent. This configuration makes it possible to switch between a state in which both the first region and the second region are opaque and a state in which the first region is opaque and the second region is translucent. This also makes it possible to improve the design of the light controlling sheet 110. In the above embodiment, the driving region 120 is the first region, and the floating region 122 is the second region.

[0230] [Fourth embodiment] A fourth embodiment of the light-adjusting sheet will be described with reference to Figures 31 to 37. The light-adjusting sheet of this embodiment is a normal type. A normal type light-adjusting sheet scatters incident light in the area to be driven when no voltage signal is applied to the light-adjusting sheet, reducing the light transmittance, and increases the light transmittance when a voltage signal is applied to the light-adjusting sheet.

[0231] [Light-adjusting sheet] 31, the light controlling sheet 210 has a first surface 211F and a second surface 211R that is the surface opposite to the first surface 211F. The light controlling sheet 210 has a driving region 220 and a non-driving region 221.

[0232] The driving region 220 is an area where driving electrode elements 230 are located, which are electrode elements to which a voltage signal is applied when the light controlling sheet 210 is driven. The light transmittance of the driving region 220 changes depending on the state of application of the voltage signal to the driving electrode elements 230. The driving electrode elements 230 are an example of a first electrode element.

[0233] The non-driving region 221 includes a floating region 222 and a boundary region 223 surrounding the floating region 222. The floating region 222 is a region where floating electrode elements 231, which are electrode elements to which no voltage signal is applied when the light controlling sheet 210 is driven, are located. The floating electrode elements 231 are an example of second electrode elements. The boundary region 223 is located between the driving region 220 and the floating region 222, and has a closed frame shape that surrounds the floating region 222. No electrode elements are located in the boundary region 223. Note that the width of the boundary region 223 is exaggerated in the drawings for ease of understanding. The light transmittance of the non-driving region 221 does not change whether the light controlling sheet 210 is driven or not.

[0234] The non-driven area 221 displays a pattern on the light controlling sheet 210. The pattern may be, for example, one of letters, numbers, symbols, figures, pictures, patterns, or a combination of these. Note that the light controlling sheet 210 shown in FIG. 31 has one star-shaped figure as the non-driven area 221, but may have multiple non-driven areas 221 that are separated from each other. In other words, the light controlling sheet 210 may have multiple boundary areas 223 that form a closed area.

[0235] The connection region 224 is a region for applying a voltage signal to the driving region 220, and is connected to external wiring 225. The connection region 224 and the driving region 220 are adjacent to each other. The location where the connection region 224 is provided is not particularly limited. The connection region 224 is located, for example, in a corner of the light controlling sheet 210.

[0236] FIG. 32 is a cross-sectional view taken along line III-III in FIG. 31, showing the cross-sectional structure of the light controlling sheet 210 in the drive region 220 and the connection region 224. Note that the thickness ratios of the layers in FIG. 32 are shown for the sake of convenience and are not limited to those shown in FIG. 32. For the sake of convenience, the antiviral film provided in the light controlling sheet 210 is omitted from FIG. 32. The light controlling sheet 210 of the fourth embodiment can be provided with the antiviral film provided in the light controlling sheet of the first embodiment, and the antiviral film or antiviral layer described in the modified example of the first embodiment.

[0237] 32, the light control sheet 210 has a light control layer 211, a first transparent electrode layer 212A, a second transparent electrode layer 212B, a first transparent support layer 213A, and a second transparent support layer 213B. The light control layer 211 is sandwiched between the first transparent electrode layer 212A and the second transparent electrode layer 212B. The first transparent support layer 213A supports the first transparent electrode layer 212A on a support surface 2130 opposite the light control layer 211 with respect to the first transparent electrode layer 212A, and the second transparent support layer 213B supports the second transparent electrode layer 212B on the opposite side of the second transparent electrode layer 212B with respect to the light control layer 211. The light control layer 211 may have a single-layer structure or a multi-layer structure. The multi-layered dimming layer 211 may include a functional layer having a dimming function and a thin layer that enhances adhesion between the functional layer and the first transparent electrode layer 212A and between the functional layer and the second transparent electrode layer 212B.

[0238] The light controlling sheet 210 further includes a protective layer 244. The protective layer 244 is located on the opposite side of the first transparent support layer 213A from the first transparent electrode layer 212A. The protective layer 244 is fixed to the first transparent support layer 213A via an adhesive layer (not shown). When the light controlling sheet 210 includes an antiviral film, the light controlling sheet 210 may include the antiviral film instead of the protective layer 244 and the adhesive layer. Alternatively, the light controlling sheet 210 may include an antiviral film on the protective layer 244. In this case, the adhesive layer of the antiviral film contacts the protective layer 244.

[0239] The first surface 211F of the light controlling sheet 210 is the surface of the protective layer 244 opposite to the surface facing the first transparent support layer 213A. The second surface 211R of the light controlling sheet 210 is the surface of the second transparent support layer 213B opposite to the surface facing the second transparent electrode layer 212B. The second surface 211R 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 in various buildings such as homes, stores, stations, and airports; partitions installed in offices, medical institutions, and nursing homes; show windows installed in stores; and window glass or windshields installed in mobile objects such as vehicles and aircraft. The surface of the transparent plate may be flat or curved. Note that if the light controlling sheet 210 includes an antiviral film, the adhesive layer of the antiviral film is located on the second surface 211R of the light controlling sheet 210, and the antiviral film is attached to the transparent plate.

[0240] The connection region 224 includes a first connection region 224A to which external wiring 225 is connected for applying a voltage signal to the first transparent electrode layer 212A, and a second connection region 224B to which external wiring 225 is connected for applying a voltage signal to the second transparent electrode layer 212B.

[0241] The first connection region 224A is an area where the light control layer 211, the second transparent electrode layer 212B, and the second transparent support layer 213B are not located, and as a result, a part of the first transparent electrode layer 212A is exposed. A first terminal 250A is connected to the part of the first transparent electrode layer 212A exposed in the first connection region 224A. That is, the driving electrode element 230 extends from the driving region 220 to the first connection region 224A, and the first terminal 250A is connected to the driving electrode element 230 in the first connection region 224A.

[0242] The second connection region 224B is an area where the light control layer 211, the first transparent electrode layer 212A, the first transparent support layer 213A, and the protective layer 244 are not located, and as a result, a part of the second transparent electrode layer 212B is exposed. A second terminal 250B is connected to the part of the second transparent electrode layer 212B exposed in the second connection region 224B. That is, the driving electrode element 230 extends from the driving region 220 to the second connection region 224B, and the second terminal 250B is connected to the driving electrode element 230 in the second connection region 224B.

[0243] External wiring 225 extends from each of the first terminal 250A and the second terminal 250B, and these external wirings 225 are connected to the control unit 250. The control unit 250 applies a voltage signal to the driving electrode element 230 of the first transparent electrode layer 212A through the first terminal 250A, and applies a voltage signal to the second transparent electrode layer 212B through the second terminal 250B. In this way, the control unit 250 controls the potential difference between the first transparent electrode layer 212A and the second transparent electrode layer 212B in the driving region 220. The second transparent electrode layer 212B is controlled to, for example, ground potential. The light control sheet 210 and the control unit 250 constitute a light control device.

[0244] The light-controlling layer 211 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 liquid crystal composition fills the voids in the transparent polymer layer. The liquid crystal composition contains liquid crystal molecules. The liquid crystal molecules may be any of the liquid crystal molecules listed in the first embodiment. When the light-controlling layer 211 has a single-layer structure, the light-controlling layer 211 consists only of a functional layer comprising a transparent polymer layer and a liquid crystal composition.

[0245] The retention type of the liquid crystal composition may be any of the retention types listed in Embodiment 1. Note that, similar to the liquid crystal composition of Embodiment 1, the liquid crystal composition may contain, in addition to the above-mentioned liquid crystal molecules, a monomer for forming a transparent polymer layer, a dichroic dye, and the like.

[0246] Each of the first transparent electrode layer 212A and the second transparent electrode layer 212B is conductive and transparent to light in the visible region. The materials for forming the first transparent electrode layer 212A and the second transparent electrode layer 212B may be any of the materials listed in the first embodiment.

[0247] Each of the first transparent support layer 213A and the second transparent support layer 213B is a base material that is transparent to light in the visible region. The materials for forming the first transparent support layer 213A and the second transparent support layer 213B may be any of the materials listed in the first embodiment.

[0248] Each of the first terminal 250A and the second terminal 250B includes, for example, a conductive adhesive layer and a wiring substrate. The conductive adhesive layer may be any of the adhesive layers listed in the first embodiment. The wiring substrate is, for example, a flexible printed circuit (FPC), as in the first embodiment.

[0249] Alternatively, each of the first terminal portion 250A and the second terminal portion 250B may have a structure in which a conductive material such as a conductive tape is joined to the external wiring 225 by soldering or the like, as in the first embodiment.

[0250] In the driving region 220, the light-controlling layer 211 changes the orientation of the liquid crystal molecules in response to a change in the voltage generated between the two transparent electrode layers 212A and 212B. The change in orientation of the liquid crystal molecules changes the degree of scattering, absorption, and transmission of visible light entering the light-controlling layer 211. Specifically, when no voltage signal is applied to the first transparent electrode layer 212A and the second transparent electrode layer 212B of the driving region 220, the orientation of the long axis direction of the liquid crystal molecules is irregular. As a result, the degree of scattering of light incident on the light-controlling layer 211 increases, and the driving region 220 appears cloudy. In other words, when no voltage signal is applied to the light-controlling layer 211, the driving region 220 is opaque. On the other hand, when a voltage signal is applied to the transparent electrode layers 212A and 212B, and a potential difference of a predetermined value or more occurs between the first transparent electrode layer 212A and the second transparent electrode layer 212B, the liquid crystal molecules are oriented, and the long axis direction of the liquid crystal molecules is oriented along the electric field direction between the transparent electrode layers 212A and 212B. As a result, light can easily pass through the dimming layer 211, and the driving region 220 becomes transparent.

[0251] FIG. 33 is a cross-sectional view taken along line IV-IV in FIG. 31, showing the cross-sectional structure of the light controlling sheet 210 in the boundary region 223 and the driving region 220 and floating region 222 sandwiching the boundary region 223.

[0252] 33, the light control layer 211 includes a plurality of spacers 215. The spacers 215 maintain a substantially constant distance between the first transparent electrode layer 212A and the second transparent electrode layer 212B. In the first transparent electrode layer 212A, the driving electrode elements 230 are located in the driving region 220, and the floating electrode elements 231 are located in the floating region 222. In other words, the driving electrode elements 230 and the floating electrode elements 231 are separate layered bodies aligned along the support surface 2130 of the first transparent support layer 213A.

[0253] The drive electrode element 230 and the floating electrode element 231 are separated by the groove 2120. The depth direction of the groove 2120 is the thickness direction of the first transparent electrode layer 212A. In the present embodiment, the groove 2120 has an opening 2122 on the light control layer 211 side of the first transparent electrode layer 212A, penetrates the first transparent electrode layer 212A, and extends to the middle of the thickness direction of the first transparent support layer 213A. By being separated by the groove 2120, the drive electrode element 230 and the floating electrode element 231 are insulated from each other. The region where the groove 2120 is located is the boundary region 223.

[0254] FIG. 34 is an enlarged view of the cross-sectional structure of the groove 2120 and its periphery in FIG. 33. The thickness T3, which is the sum of the thickness T1 of the first transparent support layer 213A and the thickness T2 of the first transparent electrode layer 212A, is 20 μm or more and 200 μm or less. The thickness T2 of the first transparent electrode layer 212A is several tens of nm. Also, the thickness of the light control layer 211 is 0.5 μm or more and 460 μm or less. The overall thickness of the light control sheet 210 is 45 μm or more and 500 μm or less. Note that the thickness of the second transparent support layer 213B may be the same as or different from the thickness of the first transparent support layer 213A. Similarly, the thickness of the second transparent electrode layer 212B may be the same as or different from the thickness of the first transparent electrode layer 212A.

[0255] When the depth of the groove 2120 is "D1", the depth of the groove 2120 satisfies "T2 < D1 < T3". As described above, the groove 2120 has a depth that penetrates the first transparent electrode layer 212A but does not penetrate the first transparent support layer 213A.

[0256] The width W1 of the groove 2120 is smaller than the diameter φ1 of the spacer 215 (width W1 < diameter φ1). When there is variation in the particle size of the spacer 215, the diameter φ1 of the spacer 215 is the diameter φ1 of the spacer 215 with the smallest particle size. Since the diameter φ1 of the spacer 215 is larger than the width W1 of the groove 2120, the spacer 215 is difficult to enter the groove 2120.

[0257] FIG. 35 is an SEM photograph of a cross-sectional structure including a groove 2120. The groove 2120 shown in the center of the SEM photograph is open on the side of the light-controlling layer 211, and is therefore filled with a light-controlling material 2110 made of a transparent polymer layer of the light-controlling layer 211 and a liquid crystal composition. If the groove 2120 is not filled with the light-controlling material 2110, light that passes through the first transparent support layer 213A and enters the inside of the groove 2120 is reflected by the side surfaces of the groove 2120. In this case, the groove 2120 is noticeable when viewed from the outside of the light-controlling sheet 210. On the other hand, because the refractive index of the material constituting the first transparent support layer 213A is closer to the refractive index of the light-controlling material 2110 than to the refractive index of air, when the groove 2120 is filled with the light-controlling material 2110 as in this embodiment, the reflectivity on the side surfaces of the groove 2120 is reduced, and the groove 2120 is less visible when viewed from the outside of the light-controlling sheet 210. Furthermore, even if a small gap 2121 (see FIG. 34) remains in the groove 2120, the groove 2120 will not be noticeable if most of the volume of the groove 2120 is filled with the light-adjusting material 2110. In order to obtain the effect of making the groove 2120 less visible from the outside, it is preferable that the filling rate of the light-adjusting material 2110 with respect to the volume of the groove 2120 be 80% or more.

[0258] Furthermore, as described above, the width W1 of the groove 2120 is smaller than the diameter φ1 of the spacer 215, which prevents the spacer 215 from entering the groove 2120, thereby preventing the groove 2120 from being impeded by the light-adjusting material 2110. Furthermore, since the thickness of the light-adjusting layer 211 is 0.5 μm or greater, the light-adjusting material 2110 is likely to be filled at a filling rate of 80% or greater. The reason for this is not yet clear, but it is thought that by increasing the thickness of the light-adjusting layer 211, a sufficient amount of the light-adjusting material 2110 is secured around the opening 2122, making it easier for the light-adjusting material 2110 to fill the groove 2120 when the light-adjusting layer 211 is sandwiched between the first transparent electrode layer 212A and the second transparent electrode layer 212B and a predetermined pressure is applied.

[0259] Furthermore, the first transparent electrode layer 212A has a burr 2123 formed around the opening 2122 of the groove 2120. The burr 2123 is generated when the groove 2120 is formed in the first transparent electrode layer 212A, and protrudes from the periphery of the opening 2122 toward the light control layer 211 side. When forming the groove 2120, it is adjusted so that the height H1 of the burr 2123 is lower than the thickness T4 of the light control layer 211 (H1 < T4). If the height H1 of the burr 2123 exceeds the thickness T4 of the light control layer 211, the first transparent electrode layer 212A contacts the second transparent electrode layer 212B through the light control layer 211, and a short circuit occurs between the first transparent electrode layer 212A and the second transparent electrode layer 212B. Also, the height H1 of the burr 2123 may be set to 0.8 times or less of the thickness T4 of the light control layer 211. By doing so, even when the light control sheet 210 is attached to a curved surface or the light control sheet 210 is unintentionally pressed, and the distance between the first transparent electrode layer 212A and the second transparent electrode layer 212B is reduced, a short circuit between the first transparent electrode layer 212A and the second transparent electrode layer 212B can be sufficiently suppressed. Note that the depth D1 of the groove 2120 is the length extending in the thickness direction of the first transparent electrode layer 212A from the surface of the first transparent electrode layer 212A on the light control layer 211 side, and does not include the height of the burr 2123.

[0260] [Method for manufacturing a light control sheet] Next, referring to FIG. 36, a method for manufacturing the light control sheet 210 will be described. First, a film 251A provided with the first transparent electrode layer 212A and the first transparent support layer 213A, and a film 251B provided with the second transparent electrode layer 212B and the second transparent support layer 213B are prepared. Among these, for the film 251A provided with the first transparent electrode layer 212A and the first transparent support layer 213A, the groove 2120 is formed from the first transparent electrode layer 212A side using a cutting plotter. A control device connected to the cutting plotter operates the cutting plotter along a previously input pattern to form the groove 2120.

[0261] The grooves 2120 may be formed using a device other than a cutting plotter. For example, the grooves 2120 may be formed in the first transparent electrode layer 212A using a blade other than a cutting plotter or a laser cutting device. As the laser cutting device, for example, a laser cutter equipped with a CO2 laser or the like may be used.

[0262] Next, a liquid containing spacers 215, whose main material is divinylbenzene or the like, and a dispersion medium for dispersing the spacers 215 is applied to the surfaces of the films 251A, 251B facing the first transparent electrode layer 212A and the second transparent electrode layer 212B. The films with the spacers 215 dispersed therein are then heated to remove the dispersion medium. At this time, the spacers 215 may be dispersed on only one of the films.

[0263] Then, a light-controlling material containing a transparent polymer material and a liquid crystal composition is applied to the first transparent electrode layer 212A of the film 251A in which the grooves 2120 are formed and the second transparent electrode layer 212B of the film 251B in which the grooves 2120 are not formed. At this time, as shown in FIG. 36, the grooves 2120 do not have to be filled with the light-controlling material. Furthermore, the films 251A and 251B are irradiated with ultraviolet light in a nitrogen atmosphere to form light-controlling layers 211A and 211B. The pair of films thus obtained are stacked and bonded together while applying a predetermined amount of pressure. This causes the light-controlling material to fill the grooves 2120.

[0264] The light-controlling sheet 210 may be manufactured by either a roll-to-roll method in which a film transported from an upstream roll is subjected to various processes and then wound onto a downstream roll, or a sheet-to-sheet method in which various processes are performed on a film cut to a predetermined size. In either case, the step of forming the grooves 2120 is performed before bonding the film consisting of the first transparent electrode layer 212A and the first transparent support layer 213A and the film consisting of the second transparent electrode layer 212B and the second transparent support layer 213B with the light-controlling layer 211 interposed therebetween.

[0265] Next, a cut of a predetermined size is made in the corner of the second surface 211R of the light controlling sheet 210, and the second transparent support layer 213B and the second transparent electrode layer 212B are peeled off. Furthermore, the light controlling layer 211 is removed, exposing the first transparent electrode layer 212A and forming the connection region 224. Similarly, the connection region 224 is also formed in the corner of the first surface 211F. Then, the first terminal portion 250A and the second terminal portion 250B are formed, and the external wiring 225 is connected to the connection region 224. Furthermore, the connection region 224 is sealed with epoxy resin or the like. The step of bonding the protective layer 244 to the first transparent support layer 213A may be performed after bonding the pair of films together.

[0266] By forming groove 2120 by cutting into first transparent electrode layer 212A and first transparent support layer 213A in this manner, groove 2120 can be formed more easily than in a manufacturing method that includes steps such as forming a resist mask required for patterning, exposure, development, etching, removing the resist mask, and cleaning.

[0267] [Effect] Next, the operation of this embodiment will be described with reference to Fig. 37. Fig. 37 schematically shows the degree of transparency of the light controlling sheet 210 when the light controlling sheet 210 is not driven, that is, when no voltage signal is applied to the first transparent electrode layer 212A and the second transparent electrode layer 212B. When the light controlling sheet 210 is not driven, both the driving region 220 and the non-driving region 221 are opaque. Therefore, the entire surface of the light controlling sheet 210 appears whitish or cloudy, for example, and images such as letters and pictures formed in the non-driving region 221 cannot be seen.

[0268] Furthermore, the grooves 2120 have a depth that penetrates the first transparent electrode layer 212A but does not penetrate the first transparent support layer 213A, and therefore the grooves 2120 are inconspicuous when viewed from either the first surface 211F or the second surface 211R of the light controlling sheet 210. In addition, by filling the grooves 2120 with a light controlling material, the grooves 2120 can be made even less visible. This improves the aesthetic appearance of the light controlling sheet 210 when a pattern is displayed.

[0269] 31, when the light controlling sheet 210 is driven, the driving area 220 becomes transparent, while the non-driving area 221 is opaque. Therefore, only the non-driving area 221 appears, for example, whitish or cloudy, and the image of the pattern such as letters or pictures that the non-driving area 221 comprises becomes visible.

[0270] As described above, according to the light controlling sheet 210 of this embodiment, regions with different light transmittances are formed within the surface of the light controlling sheet 210, and the difference in light transmittance between these regions only appears when the light controlling sheet 210 is driven. Therefore, when the light controlling sheet 210 is driven, images such as letters and pictures formed in the non-driven areas 221 are visible, making it possible to decorate the space in which the light controlling sheet 210 is placed. Furthermore, by switching between driven and non-driven states of the light controlling sheet 210, it is possible to switch whether or not the above images appear, thereby dynamically changing the decorative state of the space. This makes it possible to improve the design of the light controlling sheet 210.

[0271] As described above, the fourth embodiment of the light controlling sheet can provide the following effects. (4-1) By applying a voltage signal to only one of the driving electrode elements 230 and the floating electrode elements 231, or by applying different voltage signals to the driving electrode elements 230 and the floating electrode elements 231, it is possible to change the light transmittance between the region of the light controlling sheet 210 where the driving electrode elements 230 are located and the region where the floating electrode elements 231 are located. This makes it possible to switch between a state where there is no difference in light transmittance between the regions where these electrode elements are located without applying a voltage signal to both the driving electrode elements 230 and the floating electrode elements 231, and a state where there is a difference in light transmittance between the regions where each electrode element is located, as described above, thereby improving the design of the light controlling sheet 210. Furthermore, the grooves 2120 have a depth that penetrates the first transparent electrode layer 212A but does not penetrate the first transparent electrode layer 212A, so the grooves 2120 can be made less noticeable when the light controlling sheet 210 is viewed from the first transparent electrode layer 212A side. This can improve the aesthetic appearance of the light controlling sheet 210. Furthermore, for example, the grooves 2120 can be formed more easily than by a method that includes a step of removing the first transparent electrode layer 212A by etching or the like.

[0272] (4-2) By filling at least a portion of the groove 2120 with a portion of the light-controlling layer 211, the groove 2120 can be made less visible when the light-controlling sheet 210 is viewed from the first transparent support layer 213A side or the second transparent support layer 213B side.

[0273] (4-3) By making the filling rate of the light-controlling material in the grooves 2120 80% or more, the grooves 2120 can be made less visible. (4-4) By making the inner diameter of the opening 2122 of the groove 2120 smaller than the diameter of the spacer 215, it is possible to prevent the spacer 215 from entering the groove 2120. Therefore, the filling of the groove 2120 with the switchable layer 211 is less likely to be hindered by the spacer 215 that has entered the groove 2120.

[0274] (4-5) Because the height of the burrs 2123 present around the openings 2122 of the grooves 2120 is smaller than the thickness of the light control layer 211, it is possible to prevent the tips of the burrs 2123 formed on the first transparent electrode layer 212A from contacting the second transparent electrode layer 212B via the light control layer 211. This makes it possible to prevent a short circuit from occurring between the first transparent electrode layer 212A and the second transparent electrode layer 212B.

[0275] (4-6) The groove 2120 has a closed frame shape that surrounds the floating electrode element 231. Therefore, since the closed frame shape can partition the floating electrode element 231, it is possible to reduce constraints on the layout of the floating electrode element 231.

[0276] [Modification of the fourth embodiment] The above-described fourth embodiment can be modified and implemented as follows: In addition, the following modifications may be implemented in combination.

[0277] In the above embodiment, the grooves 2120 have a closed frame shape surrounding the floating electrode elements 231. Alternatively, the grooves 2120 do not have to have a closed frame shape surrounding the floating electrode elements 231 as long as they extend along the support surface 2130 of the first transparent support layer 213A. For example, as shown in FIG. 38 , when viewed from a position facing the first surface 211F, the boundary region 223 and the grooves 2120 may extend from a starting point located at the edge 210E of the light controlling sheet 210, through the outer periphery of the floating region 222 and the floating electrode elements 231, to an ending point located at the edge 210E of the light controlling sheet 210. In this case, the ends of the floating region 222 and the floating electrode elements 231 are located at the edge 210E of the light controlling sheet 210. In Figure 38, the lower side of the rectangular light-adjusting sheet 210 is shown as the end 210E, but the end 210E, which is the starting point and ending point of the boundary region 223 and groove 2120, may be any of the upper side, left side, or right side, or may be any of multiple sides.

[0278] In the above embodiment, the light controlling sheet 210 is of a normal type, but it may also be of a reverse type. The reverse type light controlling sheet 210 transmits incident light when no voltage signal is applied, increasing its light transmittance, and scatters incident light when a voltage signal is applied, decreasing its light transmittance.

[0279] FIG. 39 shows an example of a reverse-type light control sheet 210. As shown in FIG. 39, the light control layer 211 of the reverse-type light control sheet 210 has a multilayer structure and includes a functional layer 2111 including a transparent polymer layer and a liquid crystal composition, a first alignment layer 2112, and a second alignment layer 2113. The functional layer 2111, the first alignment layer 2112, and the second alignment layer 2113 constitute the light control layer 211. The first alignment layer 2112 is located between the functional layer 2111 and the first transparent electrode layer 212A and is in contact with these layers. The second alignment layer 2113 is located between the functional layer 2111 and the second transparent electrode layer 212B and is in contact with these layers.

[0280] Each of the first alignment layer 2112 and the second alignment layer 2113 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 211. The material for forming each of the first alignment layer 2112 and the second alignment layer 2113 may be any of the materials listed in the first embodiment.

[0281] The groove 2120 has an opening 2122 on the side of the first alignment layer 2112 facing the light control layer 211, and penetrates the first alignment layer 2112 and the first transparent electrode layer 212A but not the first transparent support layer 213A. In other words, the depth of the groove 2120 is smaller than the sum of the thicknesses of the first alignment layer 2112, the first transparent electrode layer 212A, and the first transparent support layer 213A. The groove 2120 is filled with a portion of the light control layer 211.

[0282] When the light-controlling sheet 210 includes the first alignment layer 2112 and the second alignment layer 2113, in the driving region 220, when no voltage signal is applied to the transparent electrode layers 212A and 212B, the long axis direction of the liquid crystal molecules is oriented along the thickness direction of the light-controlling layer 211. Therefore, the driving region 220 is transparent. On the other hand, when a voltage signal is applied to the transparent electrode layers 212A and 212B in the driving region 220, the long axis direction of the liquid crystal molecules is oriented intersecting the thickness direction of the light-controlling layer 211. Therefore, the driving region 220 appears cloudy and opaque. When the light-controlling sheet 210 includes the first alignment layer 2112 and the second alignment layer 2113, in the floating region 222 and the boundary region 223, the long axis direction of the liquid crystal molecules is always oriented along the thickness direction of the light-controlling layer 211, so the non-driving region 221 is always transparent.

[0283] Therefore, when the light adjusting sheet 210 is not driven, both the driving region 220 and the non-driving region 221 are transparent, and images such as letters and patterns formed in the non-driving region 221 are not visible. On the other hand, when the light adjusting sheet 210 is driven, the driving region 220 becomes opaque, while the non-driving region 221 is transparent, so that images such as letters and patterns formed in the non-driving region 221 are visible.

[0284] In this way, even when the light controlling sheet 210 includes the first alignment layer 2112 and the second alignment layer 2113, regions with different light transmittances are formed within the plane of the light controlling sheet 210, and the difference in light transmittance between these regions appears only when the light controlling sheet 210 is driven. This makes it possible to improve the design of the light controlling sheet 210.

[0285] Furthermore, in the above embodiment, the grooves 2120 penetrate the first alignment layer 2112, but the first alignment layer 2112 may be formed after the grooves 2120 are formed in a laminate consisting of the first transparent electrode layer 212A and the first transparent support layer 213A. In this case, the first alignment layer 2112 is formed so as to follow the bottom and side surfaces of the grooves 2120. This also makes it possible to make the grooves 2120 less noticeable when viewed from the outside.

[0286] In the above embodiment, a voltage signal is applied to the driving electrode element 230, which is the first electrode element, and no voltage signal is applied to the floating electrode element 231, 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 connected to the first electrode element and the terminal connected to the second electrode element are separate terminals for each voltage signal. As described above, if the second electrode element is located at the end of the light controlling sheet 210, it is easy to connect wiring to the second electrode element.

[0287] For example, the first region where the first electrode elements are located can be switched between transparent and opaque by switching the state of a voltage signal applied 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 a voltage signal applied to the second electrode elements. This configuration allows switching between four states: a state where both the first and second regions are opaque, a state where the first region is opaque and the second region is transparent, a state where the first region is transparent and the second region is opaque, and a state where both the first and second regions are opaque. This allows the decorative state of the space created by the light controlling sheet 210 to be varied in a more diverse manner, further improving the design of the light controlling sheet 210.

[0288] The light transmittance of at least one of the first and second regions may be controlled to a light transmittance between transparent and opaque. In a light-controlling sheet 210 including a light-controlling layer 211 containing a liquid crystal composition, when the potential difference between the transparent electrode layers 212A and 212B is within a predetermined range, the light transmittance of the light-controlling sheet 210 gradually changes as the potential difference changes. Therefore, by controlling the potential difference between the transparent electrode layers 212A and 212B in the first or second region to a value between the potential difference at which the region becomes transparent and the potential difference at which the region becomes opaque, the region can be controlled to be translucent, with a light transmittance between transparent and opaque.

[0289] 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, and 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. When the first region is transparent, the second region is controlled to be translucent. This configuration makes it possible to switch between a state in which both the first region and the second region are opaque and a state in which the first region is opaque and the second region is translucent. This also makes it possible to improve the design of the light controlling sheet 210.

[0290] [Fifth embodiment] A fifth embodiment of the light controlling sheet will be described with reference to Figures 40 to 47. The light controlling sheet 310 of this embodiment is a normal type. The normal type light controlling sheet 310 increases the scattering of incident light in the region to be driven when no voltage signal is applied to the light controlling sheet 310, and decreases the scattering when a voltage signal is applied to the light controlling sheet 310.

[0291] [Light-adjusting sheet] The planar structure of the light controlling sheet 310 will be described with reference to FIG. 40, the light controlling sheet 310 has a first surface 311F and a second surface 311R that is the surface opposite to the first surface 311F. The light controlling sheet 310 has a driving region 320 and a non-driving region 321.

[0292] The light controlling sheet 310 has a laminated structure. The driving region 320 is a region that includes a driving electrode element 330 as part of the laminated structure. The driving electrode element 330 is an electrode element to which a voltage signal is applied when the light controlling sheet 310 is driven. The diffuse transmittance of the driving region 320 changes depending on the state of application of a voltage signal to the driving electrode element 330. The driving electrode element 330 is an example of a first electrode element. The non-driving region 321 is a region that includes a floating electrode element 331 as part of the laminated structure. The floating electrode element 331 is an electrode element to which a voltage signal is not applied when the light controlling sheet 310 is driven. The floating electrode element 331 is an example of a second electrode element. The diffuse transmittance of the driving region 320 changes depending on the state of application of a voltage signal to the light controlling sheet 310, while the diffuse transmittance of the non-driving region 321 does not change depending on the state of application of a voltage signal to the light controlling sheet 310. In the example shown in FIG. 40 , the non-driving region 321 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.

[0293] The non-driving region 321 shown in FIG. 40 has a shape resembling a long, thin line. The non-driving region 321 is bent at multiple locations between the first end 321A and the second end 321B. The non-driving region 321 divides the driving region 320 into a second driving region 320B having a predetermined pattern shape and a first driving region 320A located outside the second driving region 320B. Furthermore, in the non-driving region 321, parts of the non-driving region 321 do not contact or intersect with other parts between the first end 321A and the second end 321B, and a distance of at least a predetermined distance is maintained between parts of the non-driving region 321 throughout the non-driving region 321. In the example shown in FIG. 40, even in region 3101 where parts of the non-driving region 321 are close to each other, a distance is maintained between parts of the non-driving region 321.

[0294] The driving regions 320A and 320B defined by the non-driving region 321 are electrically connected via a narrowed portion 330A sandwiched between the groove 3120 (see FIG. 42), i.e., located between the first and second portions of the groove 3120. The narrowed portion 330A is an example of an inter-groove region. In other words, the driving electrode element 330 includes the narrowed portion 330A included in the conductive portion 326. The conductive portion 326 is sandwiched between the first and second portions of the non-driving region 321, which includes the groove 3120 and the floating electrode element 331, and connects the first driving region 320A to the second driving region 320B. The width of the conductive portion 326, i.e., the width of the narrowed portion 330A, is narrower than the widths of the driving regions 320A and 320B. The non-driving region 321 and the conductive portion 326 surround the second driving region 320B. The first driving region 320A is an example of an outer region, and the second driving region 320B is an example of an inner region.

[0295] The light controlling sheet 310 has two connection regions 324. The connection regions 324 are regions for applying voltage signals to the driving regions 320. External wiring 325 is connected to the connection regions 324. The connection regions 324 and the driving regions 320 are adjacent to each other, and thus the driving regions 320 are connected to the connection regions 324.

[0296] One connection region 324 is a first connection region 324A, and the other connection region 324 is a second connection region 324B. The second connection region 324B is exposed to the outside of the light controlling sheet 310 when viewed from a viewpoint facing the first surface 311F of the light controlling sheet 310. The first connection region 324A is exposed to the outside of the light controlling sheet 310 when viewed from a viewpoint facing the second surface 311R of the light controlling sheet 310. The first connection region 324A and the second connection region 324B are aligned along the edge of the light controlling sheet 310. The direction in which the first connection region 324A and the second connection region 324B are aligned is the first direction.

[0297] When a voltage signal is applied to the light controlling sheet 310 via the connection region 324, the diffuse transmittance of the driving regions 320A and 320B becomes lower than when a voltage signal is not applied to the light controlling sheet 310. On the other hand, even when a voltage signal is applied to the light controlling sheet 310, the diffuse transmittance of the non-driving region 321 does not change. As a result, a pattern 3100 defined by the linear non-driving region 321 appears on the light controlling sheet 310. At this time, the diffuse transmittance is lowered in the second driving region 320B surrounded by the non-driving region 321, so that the so-called "white" pattern 3100 is displayed. Note that although the light controlling sheet 310 shown in FIG. 40 displays one pattern using the non-driving region 321, multiple patterns may be displayed. In other words, the light controlling sheet 310 may have multiple independent non-driving regions 321 that are not connected to each other.

[0298] The layered structure of the light controlling sheet 310 will be described with reference to Figures 41 and 42. Figure 41 is a cross-sectional view taken along line V-V in Figure 40, showing the cross-sectional structure of the light controlling sheet 310 in part of the drive region 320 and the connection region 324. Note that the thickness ratios of the layers in Figure 41 are shown for convenience of explanation, and the thickness ratios of the layers are not limited to those shown in the figure. Also, for convenience of illustration, Figure 41 does not show the antiviral film provided in the light controlling sheet 310. The light controlling sheet 310 of the fifth embodiment can be provided with the antiviral film provided in the light controlling sheet of the first embodiment, and the antiviral film or antiviral layer described in the modified example of the first embodiment.

[0299] As shown in FIG. 41, the light control sheet 310 has a light control layer 311, a first transparent electrode layer 312A, a second transparent electrode layer 312B, a first transparent support layer 313A, and a second transparent support layer 313B. The light control layer 311 is sandwiched between the first transparent electrode layer 312A and the second transparent electrode layer 312B. The first transparent support layer 313A supports the surface of the first transparent electrode layer 312A opposite to the surface that contacts the light control layer 311 with a support surface 3130 that is a single continuous surface. The second transparent support layer 313B supports the surface of the second transparent electrode layer 312B opposite to the surface that contacts the light control layer 311. The light control layer 311 may have a single-layer structure or a multi-layer structure. The multi-layered dimming layer 311 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 312A and between the functional layer and the second transparent electrode layer 312B.

[0300] The light controlling sheet 310 further includes a protective layer 344. The protective layer 344 is located on the opposite side of the first transparent support layer 313A from the first transparent electrode layer 312A. The protective layer 344 may be fixed to the first transparent support layer 313A via an adhesive layer (not shown). When the light controlling sheet 310 includes an antiviral film, the light controlling sheet 310 may include the antiviral film instead of the protective layer 344 and adhesive layer. Alternatively, the light controlling sheet 310 may include an antiviral film on the protective layer 344. In this case, the adhesive layer of the antiviral film contacts the protective layer 344.

[0301] The first surface 311F of the light controlling sheet 310 is the surface of the protective layer 344 opposite the surface facing the first transparent support layer 313A. The second surface 311R of the light controlling sheet 310 is the surface of the second transparent support layer 313B opposite the surface facing the second transparent electrode layer 312B. The second surface 311R 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 in various buildings such as homes, stores, stations, and airports; partitions installed in offices, medical institutions, and nursing homes; show windows installed in stores; and window glass or windshields installed in mobile objects such as vehicles and aircraft. Each surface of the transparent plate may be flat or curved. If the light controlling sheet 310 includes an antiviral film, the adhesive layer of the antiviral film is located on the second surface 311R of the light controlling sheet 310, and the antiviral film is attached to the transparent plate.

[0302] As described above, the connection region 324 includes the first connection region 324A and the second connection region 324B. The first connection region 324A is connected to the external wiring 325 for applying a voltage signal to the first transparent electrode layer 312A. The second connection region 324B is connected to the external wiring 325 for applying a voltage signal to the second transparent electrode layer 312B.

[0303] The light control layer 311, the second transparent electrode layer 312B, and the second transparent support layer 313B are not located in the first connection region 324A, so that a portion of the first transparent electrode layer 312A is exposed to the outside. The first terminal 350A is connected to the portion of the first transparent electrode layer 312A exposed in the first connection region 324A. That is, the driving electrode element 330 extends from the driving region 320 to the first connection region 324A, and the first terminal 350A is connected to the driving electrode element 330 in the first connection region 324A. That is, the first transparent electrode layer 312A includes the driving electrode element 330, the driving region 320 includes a portion of the driving electrode element 330, and the first connection region 324A includes another portion of the driving electrode element 330.

[0304] The second connection region 324B is free from the light control layer 311, the first transparent electrode layer 312A, the first transparent support layer 313A, and the protective layer 344, thereby exposing a portion of the second transparent electrode layer 312B. The second terminal 350B is connected to the portion of the second transparent electrode layer 312B exposed in the second connection region 324B.

[0305] External wiring 325 is connected to each of the first terminal 350A and the second terminal 350B. Each external wiring 325 is connected to the control unit 350. The control unit 350 applies a voltage signal to the driving electrode element 330 of the first transparent electrode layer 312A through the first terminal 350A, and applies a voltage signal to the second transparent electrode layer 312B through the second terminal 350B. In this way, the control unit 350 controls the potential difference between the first transparent electrode layer 312A and the second transparent electrode layer 312B in the driving region 320. The second transparent electrode layer 312B is controlled to, for example, ground potential. The light control sheet 310 and the control unit 350 constitute a light control device.

[0306] The light-controlling layer 311 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 liquid crystal composition fills the voids in the transparent polymer layer. The liquid crystal composition contains liquid crystal molecules. The liquid crystal molecules may be any of the liquid crystal molecules listed in the first embodiment. When the light-controlling layer 311 has a single-layer structure, the light-controlling layer 311 consists only of a functional layer comprising a transparent polymer layer and a liquid crystal composition.

[0307] The retention type of the liquid crystal composition may be any of the retention types listed in the first embodiment. As in the first embodiment, the liquid crystal composition may contain, in addition to the above-mentioned liquid crystal molecules, a monomer for forming a transparent polymer layer, a dichroic dye, and the like. In the example shown in FIG. 41, the light-controlling layer 311 includes a spacer 315. The spacer 315 maintains the thickness of the light-controlling layer 311 within a certain range.

[0308] Each of the first transparent electrode layer 312A and the second transparent electrode layer 312B is conductive and transparent to light in the visible region. The materials for forming the first transparent electrode layer 312A and the second transparent electrode layer 312B may be any of the materials listed in the first embodiment.

[0309] Each of the first transparent support layer 313A and the second transparent support layer 313B is a substrate that is transparent to light in the visible region. The materials for forming the first transparent support layer 313A and the second transparent support layer 313B may be any of the materials listed in the first embodiment.

[0310] Each of the first terminal unit 350A and the second terminal unit 350B includes, for example, a conductive adhesive layer and a wiring substrate. The conductive adhesive layer may be any of the adhesive layers listed in the first embodiment. The wiring substrate may be, for example, a flexible printed circuit (FPC), as in the first embodiment. Alternatively, each of the first terminal unit 350A and the second terminal unit 350B may be made of a conductive material such as conductive tape, as in the first embodiment. When the first terminal unit 350A and the second terminal unit 350B are made of conductive tape, the external wiring 325 may be soldered to the first terminal unit 350A and the second terminal unit 350B.

[0311] In the driving region 320, in the portion of the light-controlling layer 311 included in the driving region 320, the orientation of the liquid crystal molecules changes in response to a change in voltage generated between the first transparent electrode layer 312A and the second transparent electrode layer 312B. The change in orientation of the liquid crystal molecules changes the degree of scattering, absorption, and transmission of visible light entering the light-controlling layer 311. Specifically, when no voltage signal is applied to the first transparent electrode layer 312A and the second transparent electrode layer 312B of the driving region 320, 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 light-controlling layer 311 increases, and the driving region 320 appears cloudy. In other words, when no voltage signal is applied to the light-controlling layer 311, the driving region 320 is opaque. On the other hand, when a voltage signal is applied to first transparent electrode layer 312A and second transparent electrode layer 312B, causing a potential difference of a predetermined value or more between first transparent electrode layer 312A and second transparent electrode layer 312B, the liquid crystal molecules are oriented, with the long axis direction of the liquid crystal molecules aligning with the electric field direction between first transparent electrode layer 312A and second transparent electrode layer 312B. As a result, light can more easily pass through light control layer 311, that is, diffusion in light control layer 311 is suppressed, and driving region 320 exhibits transparency.

[0312] 42 shows a cross-sectional structure taken along line VI-VI in FIG. 40. This cross-sectional structure includes the cross-sectional structure of the non-driving region 321. As shown in FIG. 42, the driving region 320 includes a driving electrode element 330 that is part of the first transparent electrode layer 312A. The non-driving region 321 includes a floating region 322 where the floating electrode element 331 is located and a boundary region 323 where the groove 3120 is located. The groove 3120 surrounds the outer edge of the floating electrode element 331. The boundary region 323 does not include the driving electrode element 330 or the floating electrode element 331. The floating region 322 is defined by the boundary region 323 made of the groove 3120. The driving electrode element 330 and the floating electrode element 331 are separate layered bodies aligned along the support surface 3130 of the first transparent support layer 313A. In the first transparent electrode layer 312A, the groove 3120 and the floating electrode element 331 constitute a non-driving element. Of the drive electrode elements 330, the portions included in the first drive region 320A are first drive electrode elements, and the portions included in the second drive region 320B are second drive electrode elements.

[0313] The driving electrode elements 330 and the floating electrode elements 331 are separated by grooves 3120. In this embodiment, the grooves 3120 have openings 3122 on the surface of the first transparent electrode layer 312A that contacts the light control layer 311. The grooves 3120 penetrate the first transparent electrode layer 312A and extend partway through in the thickness direction of the first transparent support layer 313A. The driving electrode elements 330 and the floating electrode elements 331 are insulated from each other by being separated by the grooves 3120.

[0314] The width L2 of the grooves 3120 may be smaller than the diameter of the spacers 315. This prevents the spacers 315 from entering the grooves 3120. The grooves 3120 are filled with a liquid crystal composition. The liquid crystal composition need only fill a portion of the grooves 3120, and does not have to fill the entire grooves 3120. By filling the grooves 3120 with the liquid crystal composition, the grooves 3120 are less noticeable when the light controlling sheet 310 is viewed from a viewpoint facing the first surface 311F or a viewpoint facing the second surface 311R while the light controlling sheet 310 is not driven. In other words, because the liquid crystal composition is located in the grooves 3120, it is possible to reduce the difference in diffuse transmittance between the grooves 3120 and portions of the light controlling sheet 310 other than the grooves 3120 when no voltage is applied between the transparent electrode layers 312A and 312B. This prevents the grooves 3120 from being visible.

[0315] The non-driven region 321 will be described with reference to Figures 43 and 44. Figure 43 is an enlarged view of the region 3101 in Figure 40. 43, the conductive portion 326 including the narrowed portion 330A may be positioned so as to connect the first portion and the second portion of the non-driving region 321. Alternatively, the conductive portion 326 may be provided between the first end 321A and the second end 321B. From the viewpoint of ensuring conductivity between the first driving region 320A outside the non-driving region 321 and the second driving region 320B inside the non-driving region 321, the width L1 of the narrowed portion 330A included in the conductive portion 326 may be 1 mm or more.

[0316] 43 , the width L1 between the first end 321A of the non-driving region 321 and the facing portion of the non-driving region 321 that is closest to the first end 321A may be 1 mm or more in the direction in which the first end 321A and the facing portion are aligned. That is, in the non-driving region 321, the first portion and the second portion are separated from each other by a portion of the driving region 320. The portion of the driving region 320 that separates the first portion and the second portion of the non-driving region 321 is the conductive portion 326 including the narrowed portion 330A. The narrowed portion 330A is located between a portion of the groove 3120 that surrounds a portion of the floating electrode element 331 included in the first portion and a portion of the groove 3120 that surrounds a portion of the floating electrode element 331 included in the second portion.

[0317] By making the width L1 of the narrowing portion 330A 1 mm or more, an increase in the resistance value of the narrowing portion 330A is suppressed, thereby suppressing the occurrence of unequal diffuse transmittance in the driving regions 320A and 320B when a driving voltage is applied. For example, even when a driving voltage is applied, the occurrence of the second driving region 320B not changing from an opaque state to a transparent state is suppressed. Furthermore, when a white pattern 3100 as shown in FIG. 40 is displayed on the light controlling sheet 310, the width L1 of the narrowing portion 330A may be 30 mm or less from the viewpoint of enhancing the design. By making the width L1 of the narrowing portion 330A 30 mm or less, the desired pattern is easily displayed.

[0318] The narrowed portion 330A is an example of an inter-groove region, and is a portion of the first transparent electrode layer 312A that is constricted by the groove 3120 that defines the narrowed portion 330A. The peel strength between the narrowed portion 330A and the second transparent electrode layer 312B 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 330A and the second transparent electrode layer 312B is 0.01 N or greater, peeling can be suppressed in the portion of the light control sheet 310 that includes the narrowed portion 330A. As a result, even when the first transparent electrode layer 312A is patterned so that a narrowed portion 330A sandwiched between grooves 3120 is formed in the first transparent electrode layer 312A, poor conductivity due to peeling can be suppressed, thereby improving the design of the light-control sheet 310.

[0319] When the width of narrowed portion 330A is 2 mm or more, the peel strength between narrowed portion 330A and second transparent electrode layer 312B per unit length in the width direction of narrowed portion 330A may be 0.1 N / 10 mm. In this way, because the peel strength between narrowed portion 330A and second transparent electrode layer 312B per unit length is 0.1 N / 10 mm or more, when light controlling sheet 310 has narrowed portion 330A with a width of 2 mm or more, peeling is suppressed in the portion including narrowed portion 330A.

[0320] 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 311. The light-controlling sheet 310 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 311. The light-controlling sheet 310 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.

[0321] Furthermore, the non-driving region 321 has a bending portion 3102 according to the design 3100. The bending portion 3102 is a curved or bent portion. As shown in FIG. 43 , when the bending portion 3102 of the non-driving region 321 is curved, the minimum value of the first angle θ1 formed by the first tangent 3105 and the second tangent 3106 of the bending portion 3102 may be 10 degrees or more. The first tangent 3105 is a tangent that is tangent to a first portion of the bending portion 3102 on the outside of the bending portion 3102, and the second tangent 3106 is a tangent that is tangent to a second portion of the bending portion 3102 on the outside of the bending portion 3102. The first portion and the second portion are set at the bending portion so as to sandwich a bending point included in the bending portion 3102. The first portion and the second portion are set so as not to sandwich a part of the driving region 320 between the first portion and the second portion.

[0322] As shown in FIG. 44, the non-driving region 321 may include a bending portion 3102 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 bending portion 3102, a portion of the driving region 320 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 bending portion 3102 between a portion of the groove 3120 included in the first linear portion and a portion of the groove 3120 included in the second linear portion.

[0323] If the first angle θ1 and the second angle θ2 are less than 10 degrees, the first transparent support layer 313A and the first transparent electrode layer 312A may peel off from the adjacent layers during or after the process of forming the groove 3120. In contrast, if the first angle θ1 and the second angle θ2 are 10 degrees or greater, peeling of the first transparent support layer 313A and the first transparent electrode layer 312A can be suppressed, and the pattern drawn by the non-driven region 321 can be made clearer.

[0324] 44, the groove 3120 has a groove bend 120GB. The groove bend 120GB is a portion of the groove 3120 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.

[0325] 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 44, first, a first imaginary line along the first groove portion GB1 and a second imaginary line along the second groove portion GB2 are defined. 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.

[0326] 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.

[0327] In the groove bend portion 120GB, similar to the narrowed portion 330A, the peel strength between the inter-groove region and the second transparent electrode layer 312B may be 0.01 N or more. When the peel strength between the inter-groove region and the second transparent electrode layer 312B is 0.01 N or more, it is possible to suppress peeling that occurs in the portion of the light controlling sheet 310 that includes the inter-groove region sandwiched by the groove bend portion 120GB.

[0328] 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 312B may be 0.1 N / 10 mm. Peeling between the inter-groove region and the second transparent electrode layer 312B is suppressed in at least a portion of the light controlling sheet 310 that includes the inter-groove region. This changes the optical properties of at least a portion of the light controlling sheet 310 that includes the inter-groove region depending on whether or not a voltage is applied between the transparent electrode layers 312A and 312B, thereby improving the design of the light controlling sheet 310.

[0329] On the other hand, the first transparent electrode layer 312A includes a conductive region in addition to the grooves 3120 and the inter-groove regions. The conductive region is wider than the inter-groove regions. That is, the conductive region does not include a portion having a width smaller than that of the inter-groove regions. In the example shown in FIG. 44, the conductive region is the portion of the first transparent electrode layer 312A included in the first driving region 320A. The peel strength between the conductive region and the second transparent electrode layer 312B may be 0.38 N / 25 mm or more.

[0330] Because the peel strength between the conductive region and second transparent electrode layer 312B is 0.38 N / 25 mm, peeling from second transparent electrode layer 312B is suppressed even in groove regions that 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.

[0331] FIG. 45 shows an enlarged view of a region including the first connection region 324A and part of the non-drive region 321 in the light controlling sheet 310. 45, the first connection region 324A includes a first terminal 350A that applies a voltage to the first transparent electrode layer 312A. The first connection region 324A is bordered by a portion of the first transparent electrode layer 312A that is exposed from the light control layer 311. Like the first connection region 324A, the second connection region 324B also includes a second terminal 350B that applies a voltage to the second transparent electrode layer 312B (see FIG. 41). Like the first connection region 324A, the second connection region 324B is bordered by a portion of the second transparent electrode layer 312B that is exposed from the light control layer 311.

[0332] The first line SL1 is a line that extends along the first direction in which the first connection region 324A and the second connection region 324B are aligned and passes through the first connection region 324A. 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.

[0333] The shortest distance D between the first line SL1 passing through the first connection region and the second line SL2 passing through the groove 3120 is 5 mm or more. Therefore, even if the floating electrode element 331 is disposed near the first connection region 324A, where the shortest distance D is 50 mm or less, an increase in resistance is suppressed in the portion of the driving electrode element 330 located between the first connection region 324A and the floating electrode element 331. This prevents a decrease in the effective voltage applied to the portion of the driving electrode element 330 that is farther away from the first connection region 324A than the floating electrode element 331. This allows the optical properties of the entire light controlling sheet 310 to be changed depending on whether or not a voltage is applied between the transparent electrode layers 312A and 312B, thereby improving the design of the light controlling sheet 310.

[0334] In the first transparent electrode layer 312A, an area adjacent to the first connection area 324A is a unit area. The unit area extends along a first direction and is separated from the first connection area 324A by a first line SL1 passing through the first connection area 324A. The length of the unit area in the first direction is 100 mm, and the length of the unit area in a second direction perpendicular to the first direction is 100 mm. In the unit area, the percentage {100×A2 / (A1+A2)} of the area of ​​the floating electrode element 331 to the sum (A1+A2) of the area (A1) of the drive electrode element 330 and the area (A2) of the floating electrode element 331 may be 30% or more. This can enhance the effectiveness of the shortest distance D being 5 mm or more between the first line SL1 passing through the first connection area 324A and the second line SL2 passing through the groove 3120.

[0335] [Light control sheet manufacturing method] An example of a method for manufacturing the light controlling sheet 310 will be described with reference to FIG. First, first film 351A and second film 351B are prepared. First film 351A includes first transparent electrode layer 312A and first transparent support layer 313A. Second film 351B includes second transparent electrode layer 312B and second transparent support layer 313B.

[0336] Of these, grooves 3120 are formed in first film 351A using a cutting plotter on the surface of first transparent electrode layer 312A opposite to the surface in contact with first transparent support layer 313A. 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 3120 that penetrate first transparent electrode layer 312A and extend partway through the thickness of first transparent support layer 313A.

[0337] It should be noted that grooves 3120 may be formed using a device other than a cutting plotter. For example, grooves 3120 may be formed in first transparent electrode layer 312A 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 first transparent electrode layer 312A and first transparent support layer 313A irradiated with laser light are directly destroyed, thereby forming grooves 3120.

[0338] Next, a liquid containing spacers 315, whose main material is divinylbenzene or the like, and a dispersion medium for dispersing the spacers 315 is prepared. The liquid is then applied to the first transparent electrode layer 312A of the first film 351A and the second transparent electrode layer 312B of the second film 351B. In this way, the spacers 315 are dispersed on the first transparent electrode layer 312A and the second transparent electrode layer 312B. Furthermore, the films 351A and 351B onto which the spacers 315 have been dispersed are heated, thereby removing the dispersion medium from the liquid. Note that the spacers 315 may be dispersed only on either the first film 351A or the second film 351B.

[0339] 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 312A and the second transparent electrode layer 312B. Furthermore, the films 351A and 351B are irradiated with ultraviolet light in a nitrogen atmosphere, thereby forming light-controlling layers 311A ​​and 311B. Next, the second film 351B is laminated on the first film 351A so that the light-controlling layers 311A ​​and 311B are in contact with each other. While applying a predetermined amount of pressure to the laminate, the second film 351B is bonded to the first film 351A. This fills the groove 3120 with at least a portion of the liquid crystal composition. The groove 3120 may be filled with both a portion of the transparent polymer layer and a portion of the liquid crystal composition.

[0340] The light-controlling sheet 310 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 3120 in the first film 351A is performed before the process of bonding the second film 351B to the first film 351A with the light-controlling layer 311 interposed therebetween.

[0341] Next, a corner of the second surface 311R of the light-controlling sheet 310 having a predetermined size is cut to peel off a portion of the second transparent support layer 313B and a portion of the second transparent electrode layer 312B. This exposes a portion of the light-controlling layer 311 to the outside. Furthermore, the exposed portion of the light-controlling layer 311 is removed to expose a portion of the first transparent electrode layer 312A, thereby forming the first connection region 324A. Similarly, a second connection region 324B is formed at the corner of the first surface 311F. Then, a first terminal 350A is formed in the first connection region 324A, and a second terminal 350B is formed in the second connection region 324B. Next, the external wiring 325 is connected to each terminal 350A, 350B. Furthermore, the connection region 324 is sealed with epoxy resin or the like. The step of bonding the protective layer 344 to the first transparent support layer 313A may be performed after bonding the pair of films 351A and 351B together, or may be performed before bonding the films 351A and 351B together.

[0342] In this way, groove 3120 is formed by cutting first transparent electrode layer 312A and first transparent support layer 313A. Therefore, groove 3120 can be formed more simply than, for example, a manufacturing method that includes steps such as forming a resist mask required for patterning, etching, removing the resist mask, and cleaning.

[0343] [Effect] The operation of this embodiment will be described with reference to Figures 40 and 47. Figure 47 schematically shows the degree of transparency of the light controlling sheet 310 when the light controlling sheet 310 is not driven, that is, when no voltage signal is applied to the first transparent electrode layer 312A and the second transparent electrode layer 312B.

[0344] 47, when the light controlling sheet 310 is not driven, both the driving area 320 and the non-driving area 321 are opaque. Therefore, the entire surface of the light controlling sheet 310 appears, for example, whitish and cloudy, and images such as letters and pictures that constitute the non-driving area 321 are not visible.

[0345] Furthermore, the grooves 3120 have a depth that penetrates the first transparent electrode layer 312A but does not penetrate the first transparent support layer 313A, so the grooves 3120 are inconspicuous whether the light controlling sheet 310 is viewed from the first surface 311F or the second surface 311R. In addition, by filling the grooves 3120 with at least a liquid crystal composition of the light controlling material, the grooves 3120 can be made even less visible when the light controlling sheet 310 is not driven. This improves the aesthetic appearance of the light controlling sheet 310 when no pattern is displayed.

[0346] 40, when the light controlling sheet 310 is driven, the driving region 320 is transparent, while the non-driving region 321 is opaque. Therefore, only the non-driving region 321 appears, for example, whitish and cloudy, and images of patterns such as letters and pictures formed in the non-driving region 321 are visible. At this time, a voltage signal is applied to the second driving region 320B surrounded by the non-driving region 321 and the first driving region 320A outside the non-driving region 321, causing the driving regions 320A and 320B to appear transparent.

[0347] As described above, according to the light controlling sheet 310 of this embodiment, regions with different diffuse transmittances are formed within the surface of the light controlling sheet 310, and the difference in diffuse transmittance between these regions appears only when the light controlling sheet 310 is driven. Therefore, when the light controlling sheet 310 is driven, images such as letters and patterns formed in the non-driven region 321 are visible. This makes it possible to improve the design of the light controlling sheet 310.

[0348] The image displayed by the light-controlling sheet 310 can be used to decorate the space in which the light-controlling sheet 310 is installed. Furthermore, by switching between driving and non-driving of the light-controlling sheet 310, it is possible to switch whether or not the image appears, thereby dynamically changing the decorative state of the space.

[0349] As described above, the fifth embodiment of the light controlling sheet can provide the following effects. (5-1) Since the peel strength between the inter-groove region and the second transparent electrode layer 312B is 0.01 N or more, peeling of the light controlling sheet 310 in the portion including the inter-groove region can be suppressed.

[0350] (5-2) Since the peel strength per unit length between the narrowed portion 330A and the second transparent electrode layer 312B is 0.1 N / 10 mm or more, when the light-controlling sheet 310 has a narrowed portion 330A with a width of 2 mm or more, peeling is suppressed in the portion including the narrowed portion 330A.

[0351] (5-3) It is possible to prevent peeling of the light controlling sheet 310 in the portion including the inter-groove region sandwiched between the groove bends 120GB. (5-4) Peeling between the inter-groove region and the second transparent electrode layer 312B is suppressed in at least a part of the portion including the inter-groove region defined by the groove bend portion 120GB.

[0352] (5-5) The peel strength between the conductive region and the second transparent electrode layer 312B is 0.38 N / 25 mm, so peeling between the conductive region and the second transparent electrode layer 312B is suppressed even in the groove region, which is narrower than the conductive region.

[0353] (5-6) Even when the floating electrode element 331 is disposed near the first connection region 324A, an increase in the resistance value is suppressed in the portion of the driving electrode element 330 located between the first connection region 324A and the floating electrode element 331. This prevents a decrease in the effective voltage applied to the portion of the driving electrode element 330 that is farther away from the first connection region 324A than the floating electrode element 331.

[0354] (5-7) Since the width of the narrowed portion 330A provided in the driving electrode element 330 is 1 mm or more, peeling of the first transparent electrode layer 312A or the first transparent support layer 313A is unlikely to occur during the process of forming the groove 3120 or after the groove 3120 is formed.

[0355] (5-8) Because the width of the narrowed portion 330A is 1 mm or more, poor conduction due to increased resistance in the narrowed portion 330A is suppressed, and the diffuse transmittance of the first driving region 320A and the second driving region 320B can be appropriately controlled. Therefore, patterns can be clearly displayed on the light controlling sheet 310, improving the design of the light controlling sheet 310.

[0356] (5-9) The first driving region 320A and the second driving region 320B surrounded by the non-driving region 321 are electrically connected by the conductive portion 326 including the narrowed portion 330A, so that the changes in the diffuse transmittance of the driving regions 320A and 320B can be synchronized depending on the state of application of the voltage signal to the driving electrode element 330.

[0357] (5-10) The angle of the bent portion 3102 in the non-driving region 321 or the angle between the tangents 3105, 3106 of the bent portion 3102 is 10 degrees or more. Therefore, peeling of the first transparent electrode layer 312A or the first transparent support layer 313A is unlikely to occur in the process of forming the groove 3120, which makes it easy to form the driving electrode element 330 and the floating electrode element 331 into the desired shape. This allows a pattern to be clearly displayed on the light control sheet 310.

[0358] (5-11) The grooves 3120 that separate the driving region 320 and the non-driving region 321 penetrate the first transparent electrode layer 312A, but have a depth that does not penetrate the first transparent electrode layer 312A. Therefore, light scattering by the grooves 3120 is suppressed on the surface of the first transparent support layer 313A opposite the support surface 3130. As a result, the grooves 3120 can be made less noticeable when the light controlling sheet 310 is viewed from the first transparent electrode layer 312A side, at least from a position facing the surface opposite the support surface 3130. This improves the aesthetic appearance of the light controlling sheet 310.

[0359] [Sixth embodiment] A sixth embodiment of the light controlling sheet will be described with reference to Figure 48. Note that in the sixth embodiment, the layered structure of the light controlling sheet 310 differs from that of the light controlling sheet 310 of the fifth embodiment. Hereinafter, the same parts as in the fifth embodiment will be given the same reference numerals, and detailed description thereof will be omitted. Note that, like the light controlling sheet 310 of the fifth embodiment, the light controlling sheet of the sixth embodiment can also be provided with the antiviral film provided in the light controlling sheet of the first embodiment, and the antiviral film or antiviral layer described in the modified example of the first embodiment.

[0360] FIG. 48 shows the cross-sectional structure of the light controlling sheet 310. As shown in FIG. 48 , the driving electrode elements 330 and floating electrode elements 331 included in the first transparent electrode layer 312A are separated by grooves 3120. The grooves 3120 extend along the thickness direction of the first transparent electrode layer 312A. In this embodiment, the grooves 3120 penetrate the first transparent electrode layer 312A and the first transparent support layer 313A. The grooves 3120 have openings 3122 located on the surface of the first transparent electrode layer 312A that contacts the light control layer 311, and openings 3124 located on the surface of the first transparent support layer 313A opposite to the surface that contacts the first transparent electrode layer 312A. The driving electrode elements 330 and the floating electrode elements 331 are insulated from each other by being separated by the grooves 3120.

[0361] The light controlling sheet 310 further includes an adhesive layer 345 and a protective layer 344. A portion of the adhesive layer 345 fills the grooves 3120. The adhesive layer 345 may be formed from a light-transmitting material that can bond the protective layer 344 and the first transparent support layer 313A together. For example, the adhesive layer 345 is an optical clear adhesive film that bonds the first transparent support layer 313A and the protective layer 344 together. If the light controlling sheet 310 includes an antiviral film, the antiviral film may be provided instead of the adhesive layer 345 and the protective layer 344. Alternatively, the light controlling sheet 310 may include an antiviral film located on the protective layer 344. In this case, the adhesive layer of the antiviral film contacts the protective layer 344.

[0362] In the light controlling sheet 310 of this embodiment, as in the light controlling sheet 310 of the fifth embodiment, the peel strength between the narrowing portion 330A and the second transparent electrode layer 312B may be 0.01 N or more. Furthermore, when the width of the narrowing portion 330A is 2 mm or more, the peel strength between the narrowing portion 330A and the second transparent electrode layer 312B per unit length in the width direction of the narrowing portion 330A 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 312B 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 312B per unit length in the width direction of the inter-groove region may be 0.1 N / 10 mm.

[0363] [Light control sheet manufacturing method] An example of a method for manufacturing the light controlling sheet 310 will be described. As in the fifth embodiment, a first film 351A including a first transparent electrode layer 312A and a first transparent support layer 313A, and a second film 351B including a second transparent electrode layer 312B and a second transparent support layer 313B are prepared. Furthermore, spacers 315 are dispersed on each of the films 351A and 351B, and then a light-controlling material containing a polymerizable composition and a liquid crystal composition is applied. After forming light-controlling layers 311A ​​and 311B from the light-controlling material, the pair of films 351A and 351B are laminated together, and the second film 351B is bonded to the first film 351A while applying a predetermined amount of pressure to the pair of films 351A and 351B.

[0364] In the laminate thus formed, an incision is made from surface 3131 (see FIG. 48) opposite support surface 3130 of first transparent support layer 313A to light-control layer 311. This forms groove 3120 that penetrates first transparent support layer 313A and first transparent electrode layer 312A. Note that groove 3120 can be formed by a method similar to that of the first embodiment. Thereafter, adhesive layer 345 and protective layer 344 are overlaid on surface 3131 of first transparent support layer 313A.

[0365] In this way, when grooves 3120 are formed in the light controlling sheet 310 after forming the light controlling sheet 310 including the first transparent electrode layer 312A, the second transparent electrode layer 312B, the light controlling layer 311, and the first transparent support layer 313A, the light controlling sheet 310 may satisfy the following. That is, the light controlling sheet 310 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 310 may be 0.38 N / 25 mm or more. The inter-groove regions may be narrowed portions 330A as described above, or may be regions surrounded by groove bends 120GB.

[0366] In this case, even if the first transparent electrode layer 312A of the light controlling sheet 310 is patterned to have inter-groove regions, peeling is prevented from occurring in the portion of the light controlling sheet 310 that includes the inter-groove regions. This makes it possible to prevent poor conduction caused by peeling, thereby improving the design of the light controlling sheet 310.

[0367] The grooves 3120 do not have to be formed after forming a laminate in which the light-controlling layer 311 is sandwiched between the films 351A and 351B. For example, the grooves 3120 may be formed between any of the following steps in the process of forming the laminate. That is, the grooves 3120 may be formed before the step of spraying the spacers 315 on the first film 351A, between the step of spraying the spacers 315 and the step of applying the light-controlling material, between the step of forming the light-controlling layer 311A ​​and the step of laminating the films 351A and 351B, etc.

[0368] According to the sixth embodiment, in addition to the above-mentioned effects (5-1) to (5-10), the following effects can be obtained. (6-1) Even if the first transparent electrode layer 312A of the light controlling sheet 310 is patterned to have inter-groove regions, peeling is prevented from occurring in the portion of the light controlling sheet 310 that includes the inter-groove regions.

[0369] (6-2) Because the grooves 3120 have a depth that penetrates the first transparent support layer 313A and the first transparent electrode layer 312A, the grooves 3120 can be formed after laminating the first transparent support layer 313A, the first transparent electrode layer 312A, the light control layer 311, the second transparent electrode layer 312B, and the second transparent support layer 313B. It is also possible to form the grooves 3120 between the steps of forming each layer. This allows for greater flexibility in the manufacturing process of the light control sheet 310.

[0370] [Modifications of the Fifth and Sixth Embodiments] The above-described embodiments can be modified as follows: The following modifications may be combined and implemented.

[0371] Number of Undriven Regions In each embodiment, the second driving region 320B surrounded by a linear non-driving region 321 and the first driving region 320A located outside the non-driving region 321 are connected by a conductive portion 326 including a narrowing portion 330A, but the number of non-driving regions 321 provided in the light control sheet 310 is not limited to one.

[0372] FIG. 49 shows an example of a light controlling sheet 310 provided with a plurality of non-driving areas 321. As shown in Fig. 49, the non-driven area 321 includes a floating area 322 and a boundary area 323. The boundary area 323 has a frame shape. The boundary area 323 defines the floating area 322, which is a closed area. In the example shown in Fig. 49, the boundary area 323 included in the light controlling sheet 310 surrounds the floating area 322, which has a star shape. In other words, the floating area 322 is defined by the boundary area 323, which has a hollow star shape.

[0373] The light controlling sheet 310 has two different non-driving regions 321 that are independent of each other. Between the two non-driving regions 321, a narrowed portion 330A is located, sandwiched between two different grooves 3120. The narrowed portion 330A is a portion of the first transparent electrode layer 312A whose width is narrowed by two different grooves 3120 being close to each other. In the light controlling sheet 310, the portion including the narrowed portion 330A is a conductive portion 327, and the conductive portion 327 provides electrical conductivity to the driving regions 320 located around the conductive portion 327.

[0374] The width L3 of the narrowed portion 330A may be 1 mm or more. In other words, the distance between two different non-driving regions 321 may be 1 mm or more. When the width L3 of the narrowed portion 330A is 1 mm or more, a decrease in conductivity in the narrowed portion 330A is suppressed, and this makes it easier to equalize the diffuse transmittance in the driving regions 320 connected via the narrowed portion 330A. Note that although the light controlling sheet 310 shown in FIG. 49 has two non-driving regions 321, the light controlling sheet 310 may have three or more non-driving regions 321.

[0375] In each embodiment, the groove 3120 has a closed frame shape surrounding the floating electrode element 331. Alternatively, the groove 3120 does not have to have a closed frame shape surrounding the floating electrode element 331 as long as it extends along the support surface 3130 of the first transparent support layer 313A and satisfies the following conditions: For example, the groove 3120 may extend from a starting point located at a first end of one of the four sides of the rectangular light controlling sheet 310, pass around the periphery of the floating region 322, 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 310, or on a different side. Even if the light controlling sheet 310 is not rectangular, the starting and ending points of the groove 3120 may be located at the ends of the light controlling sheet 310, and the groove 3120 may pass around the periphery of the floating region 322 during its extension.

[0376] [Light control sheet type] The light controlling sheet 310 may be of a reverse type. In the reverse type light controlling sheet 310, when no voltage signal is applied between the transparent electrode layers 312A and 312B, 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.

[0377] FIG. 50 shows an example of a reverse-type light controlling sheet 310. As shown in Figure 50, the reverse-type light control sheet 310 includes a functional layer 3111 including a transparent polymer layer and a liquid crystal composition, a first alignment layer 3112, and a second alignment layer 3113. The functional layer 3111, the first alignment layer 3112, and the second alignment layer 3113 constitute the light control layer 311. The first alignment layer 3112 is located between the functional layer 3111 and the first transparent electrode layer 312A and is in contact with these layers. The second alignment layer 3113 is located between the functional layer 3111 and the second transparent electrode layer 312B and is in contact with these layers.

[0378] Each of the first alignment layer 3112 and the second alignment layer 3113 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 311. In this way, the first alignment layer 3112 and the second alignment layer 3113 regulate the alignment of the multiple liquid crystal molecules contained in the light control layer 311. The material for forming each of the first alignment layer 3112 and the second alignment layer 3113 may be any of the materials listed in the first embodiment.

[0379] The grooves 3120 have openings 3122 on the surface of the first alignment layer 3112 that contacts the light control layer 311, and penetrate the first alignment layer 3112 and the first transparent electrode layer 312A but do not penetrate the first transparent support layer 313A. In other words, the depth of the grooves 3120 is smaller than the sum of the thicknesses of the first alignment layer 3112, the first transparent electrode layer 312A, and the first transparent support layer 313A. A portion of the light control layer 311 is filled into the grooves 3120. The grooves 3120 may also penetrate the first transparent support layer 313A, similar to the grooves 3120 provided in the light control sheet 310 of the sixth embodiment.

[0380] When the light-controlling sheet 310 includes the first alignment layer 3112 and the second alignment layer 3113, in the driving region 320, when no voltage signal is applied to the first transparent electrode layer 312A and the second transparent electrode layer 312B, the long axis direction of the liquid crystal molecules is aligned with the thickness direction of the light-controlling layer 311. Therefore, the driving region 320 is transparent. On the other hand, when a voltage signal is applied to the first transparent electrode layer 312A and the second transparent electrode layer 312B in the driving region 320, the long axis direction of the liquid crystal molecules intersects with the thickness direction of the light-controlling layer 311. Therefore, the driving region 320 appears cloudy, in other words, opaque. When the light-controlling sheet 310 includes the first alignment layer 3112 and the second alignment layer 3113, in the floating region 322 and the boundary region 323, the long axis direction of the liquid crystal molecules is always aligned with the thickness direction of the light-controlling layer 311, so the non-driving region 321 is always transparent.

[0381] Therefore, when the light adjusting sheet 310 is not driven, all of the driving regions 320 are transparent, and images such as letters and patterns formed in the non-driving regions 321 are not visible. On the other hand, when the light adjusting sheet 310 is driven, the driving regions 320 become opaque, while the non-driving regions 321 are transparent, so that images such as letters and patterns formed in the non-driving regions 321 are visible.

[0382] In this way, even when the light controlling sheet 310 includes the first alignment layer 3112 and the second alignment layer 3113, regions with different diffuse transmittances are formed within the plane of the light controlling sheet 310, and the difference in diffuse transmittance between these regions only appears when the light controlling sheet 310 is driven. This makes it possible to improve the design of the light controlling sheet 310.

[0383] 50, the grooves 3120 penetrate the first alignment layer 3112, but the first alignment layer 3112 may be formed after the grooves 3120 are formed in a laminate consisting of the first transparent electrode layer 312A and the first transparent support layer 313A. In this case, the first alignment layer 3112 is formed so as to follow the bottom and side surfaces of the grooves 3120. Even in this case, the grooves 3120 can be made less noticeable when the light controlling sheet 310 is viewed from a viewpoint facing the first surface 311F or the second surface 311R of the light controlling sheet.

[0384] Groove Position As shown in FIG. 49 , when the light controlling sheet 310 has multiple grooves 3120, the grooves 3120 may be located at the same depth in the stacking direction of the layers constituting the light controlling sheet 310, i.e., in the thickness direction of the light controlling sheet 310. Alternatively, the multiple grooves 3120 may be located at different depths in the stacking direction. Examples are listed in FIGS. 51 to 53 , and in each of these examples, the grooves 3120 can be formed using the methods described in the above-mentioned embodiments. While the following describes a normal-type light controlling sheet 310, the following examples may also be applied to a reverse-type light controlling sheet 310. Furthermore, in the examples shown in FIGS. 51 to 53 , the grooves 3120 are not filled with a light controlling material, but at least a portion of the grooves 3120 may be filled with a light controlling material.

[0385] 51, first groove 3120A penetrates first transparent support layer 313A and first transparent electrode layer 312A. In contrast, second groove 3120B penetrates only second transparent electrode layer 312B. Second groove 3120B may be formed in second transparent electrode layer 312B via second transparent support layer 313B. In this case, second groove 3120B may be formed using, for example, a laser cutting device.

[0386] 52, multiple grooves 3120 are formed by cutting from first transparent support layer 313A through at least first transparent support layer 313A and first transparent electrode layer 312A. First groove 3120A penetrates first transparent support layer 313A and first transparent electrode layer 312A. Second groove 3120B penetrates first transparent support layer 313A, first transparent electrode layer 312A, and also light control layer 311 and second transparent electrode layer 312B.

[0387] 53, first groove 3120A penetrates first transparent support layer 313A and first transparent electrode layer 312A. Second groove 3120B penetrates second transparent support layer 313B and second transparent electrode layer 312B.

[0388] 51 to 53, in a plan view facing the first surface 311F of the light controlling sheet 310, the second grooves 3120B do not overlap the first grooves 3120A. The region where each groove 3120A, 3120B is located is the boundary region 323. Furthermore, if the first grooves 3120A and the second grooves 3120B are formed close to each other at the same position in the stacking direction of the light controlling sheet 310, the strength of the region between the grooves 3120A, 3120B and its vicinity is likely to decrease. In this regard, as described above, by forming the grooves 3120A, 3120B at different positions in the stacking direction, it is possible to prevent a decrease in the strength of the light controlling sheet 310 even if the grooves 3120A, 3120B are formed close to each other.

[0389] [Floating electrode element] In each embodiment, a voltage signal is applied to the driving electrode element 330, which is the first electrode element, and no voltage signal is applied to the floating electrode element 331, 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 connected to the first electrode element and the terminal connected to the second electrode element are separate terminals for each voltage signal.

[0390] As described above, when the second electrode elements are located at the edge of the light controlling sheet 310, 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.

[0391] In this case, the state of the light controlling sheet 310 can be switched among 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 310 to be changed in a more diverse manner, further improving the design of the light controlling sheet 310.

[0392] 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 310 including a light-controlling layer 311 containing a liquid crystal composition, when the potential difference between the first transparent electrode layer 312A and the second transparent electrode layer 312B is within a predetermined range, the diffuse transmittance of the light-controlling sheet 310 gradually changes as the potential difference changes. Therefore, by controlling the potential difference between the first transparent electrode layer 312A and the second transparent electrode layer 312B 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.

[0393] 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 allows for improved design of the light controlling sheet 310.

[0394] [Number of stenoses] In the fifth embodiment, the drive regions 320A and 320B defined by the non-drive region 321 are electrically connected to each other through one narrowing portion 330A. Alternatively, the drive regions 320A and 320B defined by the non-drive region 321 may be electrically connected to each other through multiple narrowing portions 330A. In other words, the light controlling sheet 310 may include multiple conductive portions 326 sandwiched between the non-drive regions 321. Each narrowing portion 330A has the same configuration as the narrowing portion 330A in the fifth embodiment. For example, as shown in FIG. 54, the drive regions 320A and 320B may be electrically connected to each other through two narrowing portions 330A. The width of each narrowing portion 330A may be, for example, 1 mm or more. In this case, the light controlling sheet 310 has two non-driving regions 321, and each non-driving region 321 has a first end 321A and a second end 321B. In the example shown in Fig. 54, one narrowed portion 330A is located between the second end 321B of the first non-driving region 321 and the first end 321A of the second non-driving region 321.

[0395] [Width of the narrowed part] The width L1 of the narrowing portion 330A may be less than 1 mm. Even in this case, by increasing the voltage applied between the transparent electrode layers 312A and 312B compared to when the width L1 of the narrowing portion 330A is 1 mm or greater, it is possible to reduce the difference in diffuse transmittance between the first driving region 320A and the second driving region 320B connected by the conductive portion 326 including the narrowing portion 330A. Alternatively, by reducing the area of ​​the second driving region 320B connected to the conductive portion 326 including the narrowing portion 330A compared to when the width of the narrowing portion 330A is 1 mm or greater, it is possible to reduce the difference in diffuse transmittance between the first driving region 320A and the second driving region 320B.

[0396] [Non-Driven Area] The light controlling sheet 310 may include the first electrode element and the groove 3120C but may not include the second electrode element. The groove 3120C has a width wide enough that an observer can recognize the shape of the groove 3120C when viewing the light controlling sheet 310 from a viewpoint opposite the first surface 311F of the light controlling sheet 310. In the example shown in FIG. 55, the light controlling sheet 310 includes the first electrode element and the groove 3120C but does not include the second electrode element insulated from the first electrode element by the groove 3120C. The diffuse transmittance of the portion of the light controlling sheet 310 including the first electrode element changes depending on the state of application of a voltage signal. The groove 3120C may be a recess that does not penetrate the light controlling sheet 310.

[0397] In the example shown in Figure 55, the grooves 3120C have a C-shape. In the light controlling sheet 310, the areas where the grooves 3120C are formed do not include electrode elements. The grooves 3120C are filled with at least one of a transparent polymer layer and a liquid crystal composition. Alternatively, the grooves 3120C may be filled with a substance other than the transparent polymer layer and the liquid crystal composition, or the grooves 3120C may be voids that are not filled with a substance.

[0398] Note that when the grooves 3120C are filled with at least one of a liquid crystal composition and a transparent polymer layer, the grooves 3120C have scattering properties. In this case, when the light controlling sheet 310 is not driven, both the driving region 320 where the grooves 3120C are not formed and the grooves 3120C are opaque. On the other hand, when the light controlling sheet 310 is driven, the driving region 320 is transparent, while the grooves 3120C remain opaque. Therefore, only the grooves 3120C appear whitish, in other words, cloudy, and thus the image of the pattern, such as letters or pictures, formed by the grooves 3120C can be seen. In the example shown in FIG. 55, the letter "C" is visible.

[0399] In contrast, when the grooves 3120C 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 3120C are voids, the grooves 3120 are transparent. In this case, when the light controlling sheet 310 is driven, the driving regions 320 in which the grooves 3120C are not formed and the grooves 3120C are both transparent. On the other hand, when the light controlling sheet 310 is not driven, the driving regions 320 are opaque, while the grooves 3120C remain transparent. Therefore, graphic images such as letters and patterns formed by the grooves 3120C are visible.

[0400] Furthermore, when the light controlling sheet 310 has multiple grooves 3120C, the width L30 of the narrowed portion 330A defined by the multiple grooves 3120C may be 1 mm or more. Furthermore, the width L10 of the narrowed portion 330A formed by one groove 3120C may be 1 mm or more. In the first transparent electrode layer 312A, the region surrounded by the grooves 3120C is the second drive electrode element, and the region located outside the grooves 3120C and connected to the second drive electrode element is the first drive electrode element.

[0401] [Test example] A test example will be described with reference to FIGS. [Resistance value] [Test Example 2-1] As shown in FIG. 56, a rectangular resistance measurement area 3143 was formed on a substrate having a transparent electrode layer 3140 and a transparent support layer 3141. The resistance measurement area 3143 was 50 mm × 25 mm in size. Two resistance measurement areas 3143 were connected via a narrowed portion 3144 (conductive portion) having a width L4 of 50 mm and a length L5 of 100 mm, thereby preparing a measurement sample. The measurement sample was prepared so that the long sides of each resistance measurement area 3143 were connected by the narrowed portion 3144. Furthermore, a tester was connected to the two resistance measurement areas 3143, and the resistance was measured.

[0402] [Test Example 2-2] A measurement sample for Test Example 2-2 was prepared in the same manner as in Test Example 2-1, except that the width L4 of the narrowed portion 3144 in Test Example 2-1 was set to 20 mm.

[0403] [Test Example 2-3] A measurement sample for Test Example 2-3 was prepared in the same manner as in Test Example 2-1, except that the width L4 of the narrowed portion 3144 in Test Example 2-1 was set to 10 mm.

[0404] [Test Example 2-4] A measurement sample for Test Example 2-4 was prepared in the same manner as in Test Example 2-1, except that the width L4 of the narrowed portion 3144 in Test Example 2-1 was set to 5 mm.

[0405] [Test Example 2-5] A measurement sample for Test Example 2-5 was prepared in the same manner as in Test Example 2-1, except that the width L4 of the narrowed portion 3144 in Test Example 2-1 was set to 2 mm.

[0406] [Test Example 2-6] A measurement sample for Test Example 2-6 was prepared in the same manner as in Test Example 2-1, except that the width L4 of the narrowed portion 3144 in Test Example 2-1 was set to 1 mm.

[0407] [Test Example 2-7] A measurement sample for Test Example 2-7 was prepared in the same manner as in Test Example 2-1, except that the width L4 of the narrowed portion 3144 in Test Example 2-1 was set to 0.5 mm.

[0408] [Measurement method and evaluation results] The resistance value of each measurement sample was measured using a digital multimeter (TY530, manufactured by Yokogawa Measurement Corporation).

[0409] 57, the resistance values ​​(Ω) of the measurement samples of Test Examples 2-1 to 2-6 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 3144 became smaller. The resistance value of the measurement sample of Test Example 2-7 was 26,800Ω, which was observed to be dramatically higher than that of Tests 2-1 to 2-6.

[0410] [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 2-8] A light-controlling sheet with a layered structure similar to the light-controlling sheet 310 shown in Figure 41 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 part including a constriction. The widths of the conductive part and the constriction were set to 50 mm, and the length of the constriction was set to 100 mm.

[0411] Furthermore, two connection areas were formed in each characteristic measurement area using a method similar to the method for forming connection areas in the light controlling sheet 310 shown in FIG. 41. 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.

[0412] [Test Example 2-9] 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 2-10] 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.

[0413] [Test Example 2-11] 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 2-12] 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.

[0414] [Test Example 2-13] 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 2-14] 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.

[0415] [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.

[0416] As shown in Figure 58, in Test Examples 2-8 to 2-13, 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 2-8 to 2-13, the effective voltage decreased as the width of the constricted portion included in the conductive portion became narrower, but there was no significant change in the effective voltage. In contrast, in Test Example 2-14, 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 2-14, repeated starting and stopping of voltage application caused poor continuity.

[0417] [Peel strength] [Test Example 3-1] 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 3-1.

[0418] [Test Example 3-2] A light-controlling sheet of Test Example 3-2 was obtained in the same manner as in Test Example 3-1, except that the ratio of the mass of the monomer to the mass of the liquid crystal in the coating liquid was made smaller.

[0419] [Test Example 3-3] A light-controlling sheet of Test Example 3-3 was obtained in the same manner as in Test Example 3-2, except that the ratio of the mass of the monomer to the mass of the liquid crystal in the coating liquid was made smaller.

[0420] [Test Example 3-4] A light-controlling sheet of Test Example 3-4 was obtained in the same manner as Test Example 3-1, except that the acrylic monomer contained in the coating liquid in Test Example 3-1 was changed to an acrylic monomer with lower adhesion to each transparent film.

[0421] [Test Example 3-5] A light-controlling sheet of Test Example 3-5 was obtained in the same manner as in Test Example 3-3, except that the ratio of the mass of the monomer to the mass of the liquid crystal in the coating liquid was made smaller.

[0422] [Test Example 3-6] A light-control sheet of Test Example 3-6 was obtained in the same manner as in Test Example 3-1, except that the time for irradiating the coating liquid with ultraviolet light was shortened.

[0423] [Test Example 3-7] The light-control sheet of Test Example 3-7 was obtained in the same manner as Test Example 3-5, except that the acrylic monomer contained in the coating liquid in Test Example 3-5 was changed to an acrylic monomer with lower adhesion to each transparent film.

[0424] [Test Example 3-8] A light-control sheet of Test Example 3-8 was obtained in the same manner as in Test Example 3-6, except that the time for irradiating the coating liquid with ultraviolet light was shortened.

[0425] [Measurement method and evaluation results] From each light-controlling sheet, a first test piece with a width of 2 mm, a test piece with a width of 5 mm, a test piece with a width of 10 mm, a test piece with a width of 15 mm, a test piece with a width of 20 mm, and a test piece with a width of 25 mm were cut out. The peel strength of each test piece 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 peel strength evaluation results are shown in Figure 59. A small tabletop testing machine (Shimadzu Corporation, EZ-LX) was used to measure the peel strength.

[0426] 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.

[0427] As shown in Figure 59, in each test example, the peel strength of the test specimen increased with increasing specimen width. In test example 3-1, the peel strength was found to be within the range of 0.022 N to 0.616 N, and in test example 3-2, the peel strength was found to be within the range of 0.025 N to 0.610 N. In test example 3-3, the peel strength was found to be within the range of 0.021 N to 0.530 N, and in test example 3-4, the peel strength was found to be within the range of 0.019 N to 0.469 N. In test example 3-5, the peel strength was found to be within the range of 0.014 N to 0.400 N, and in test example 3-6, the peel strength was found to be within the range of 0.015 N to 0.380 N. In Test Example 3-7, 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 3-8, the peel strength was found to be within the range of 0.002 N or more and 0.060 N or less.

[0428] 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 3-1 to Test Example 3-6, 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.

[0429] In contrast, in the light-adjusting sheet of Test Example 3-7, 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 3-8, 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.

[0430] When the cross-sectional structure of the conductive portion was confirmed in Test Example 3-7 and Test Example 3-8, peeling was observed in the conductive portion when the narrowed portion width was 2 mm in Test Example 3-7. 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 3-8. 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.

[0431] 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.

[0432] Figure 60 shows the relationship between the peel strength of a test piece having a width of 10 mm in each test example and the peel strength of a test piece having a width of 5 mm in that test example, and the relationship between the peel strength of a test piece having a width of 10 mm in each test example and the peel strength of a test piece having a width of 2 mm in that test example.

[0433] 60 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]

[0434] 21...Light-adjusting sheet 31...Photochromic layer 34...First transparent electrode layer 35...Second transparent electrode layer 41...1st Antiviral Film 41A…Base material layer 41B...Antiviral layer 41C…Adhesive layer 42...Second antiviral film

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 first transparent support layer located on the opposite side of the first transparent electrode layer from the light control layer; an antiviral layer located on the opposite side of the first transparent electrode layer with respect to the first transparent support layer, the antiviral layer including an antiviral agent; a covering layer located between the first transparent support layer and the antiviral layer, the first transparent support layer includes a support surface that supports the first transparent electrode layer and a protected surface that is a surface opposite to the support surface, the first transparent electrode layer includes a first electrode element and a second electrode element; the first electrode element and the second electrode element are separate layered bodies arranged along the support surface, and are electrically insulated from each other by grooves extending in a direction along the support surface; a thickness direction of the first transparent electrode layer is a depth direction of the groove, the groove penetrates the first transparent support layer and the first transparent electrode layer in the depth direction, and has an opening in the surface to be protected; The opening is covered with the covering layer. Dimming sheet.

2. The liquid crystal display device further includes an alignment layer sandwiched between the first transparent electrode layer and the light-controlling layer, the alignment layer being configured to increase the haze of the light-controlling layer by applying a voltage to the first transparent electrode layer; the light-controlling layer comprises a resin layer located between the first transparent electrode layer and the second transparent electrode layer and having voids dispersed therein, and a liquid crystal composition containing liquid crystal molecules and filling the voids; a first high density portion in which the density of the liquid crystal composition per unit thickness is high; a low-density portion in which the density of the liquid crystal composition per unit thickness is lower than that of the first high-density portion, The first high density portion is in contact with the first alignment layer. The light-controlling sheet according to claim 1 .

3. The groove is a first groove, the first transparent electrode layer includes a third electrode element and a fourth electrode element; the third electrode element and the fourth electrode element are separate layers aligned along the support surface and are electrically insulated from each other by a second groove extending along the support surface; a depth direction of the second groove is a thickness direction of the first transparent electrode layer, The second groove penetrates the first transparent electrode layer and extends partway through the first transparent support layer in the thickness direction, and has a depth that does not penetrate the first transparent support layer. The light-controlling sheet according to claim 1 or 2.

4. The groove is a first groove, the first transparent electrode layer includes a third electrode element and a fourth electrode element; the third electrode element and the fourth electrode element are separate layers aligned along the support surface and are electrically insulated from each other by a second groove extending along the support surface; the third electrode element has a narrowed portion sandwiched by the second groove, The width of the narrowed portion is 1 mm or more and 30 mm or less. The light-controlling sheet according to claim 1 or 2.

Images