Light-adjusting sheet

Abstract

To provide a dimming sheet capable of suppressing occurrence of ion migration between ends of transparent electrode layers.SOLUTION: A first transparent electrode layer 22 included in a dimming sheet comprises: an electrode section 30 to which a drive voltage is applied; an outer peripheral conductive section 31 that is positioned on an outside of the electrode section 30 and includes an end face of the first transparent electrode layer 22; a high resistance section 33 that electrically connects the electrode section 30 and the outer peripheral conductive section 31 therebetween, the high resistance section 33 having a higher resistance per unit area than that of the electrode section 30; and a non-conductive section 32 that linearly extends, the non-conductive section 32 partitioning the electrode section 30, the outer peripheral conductive section 31, and the high resistance section 33.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a light control sheet with variable light transmittance. [Background technology]

[0002] The light-controlling sheet comprises a light-controlling layer containing a liquid crystal composition and a pair of transparent electrode layers sandwiching the light-controlling layer. A driving voltage is applied between the pair of transparent electrode layers. The orientation state of the liquid crystal molecules changes depending on the potential difference between the transparent electrode layers, thereby changing the light transmittance of the light-controlling sheet (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-113746 Summary of the Invention [Problem to be solved by the invention]

[0004] If conductive impurities such as conductive dust or moisture adhere to the edge of the light-controlling sheet, defects such as short circuits or corrosion may occur at the edge of the transparent electrode layer located near that edge. In particular, because a high electric field is generated in the light-controlling sheet when a driving voltage is applied, if moisture adheres to the edge of the light-controlling sheet, ion migration occurs between the edges of the transparent electrode layer, causing driving defects.

[0005] In the past, in order to prevent defects from occurring at the ends of the transparent electrode layer and to prevent deterioration of the liquid crystal composition due to the intrusion of outside air or moisture into the light-controlling layer, a structure has been proposed in which a resin sealing portion is provided at the end of the light-controlling sheet to cover the end surface of the light-controlling sheet.

[0006] However, it is difficult to completely prevent moisture that adhered before the formation of the sealing portion from remaining or from permeating through the sealing portion. In particular, under high temperature and humidity conditions where the progression of ion migration accelerates, the occurrence of ion migration remains a major problem even when a sealing portion is provided. [Means for solving the problem]

[0007] A light-controlling sheet that solves the above problem is a light-controlling sheet comprising a light-controlling layer containing a liquid crystal composition and a pair of transparent electrode layers, a first transparent electrode layer and a second transparent electrode layer, sandwiching the light-controlling layer. When viewed from a position facing the surface of the light-controlling sheet, the first transparent electrode layer comprises: an electrode portion to which a driving voltage is applied; a peripheral conductive portion located outside the electrode portion and including the end face of the first transparent electrode layer; a high-resistance portion that electrically connects the electrode portion and the peripheral conductive portion, the high-resistance portion having a higher resistance per unit area than the electrode portion; and a linearly extending non-conductive portion that separates the electrode portion, the peripheral conductive portion, and the high-resistance portion.

[0008] According to the above configuration, when a driving voltage is applied, the potential difference between the transparent electrode layers near the edge of the first transparent electrode layer is smaller than when the first transparent electrode layer is composed only of the electrode portion. Furthermore, the electric field strength near the edge of the light-control sheet is weaker than in the region where the electrode portion is located. Therefore, ion migration between the edges of the transparent electrode layer can be suppressed.

[0009] In the above configuration, when viewed from a position facing the surface of the light controlling sheet, the high resistance portion may have a strip shape sandwiched between two linear portions included in the non-conductive portion. According to the above configuration, a high resistance portion having a high resistance can be suitably realized.

[0010] In the above configuration, the high resistance portion may extend linearly when viewed from a position facing the surface of the light controlling sheet. According to the above configuration, it is easy to design the shape of the high resistance portion and the size of the resistance.

[0011] In the above configuration, when viewed from a position facing the surface of the light-adjusting sheet, the second transparent electrode layer may include an electrode portion to which a driving voltage is applied, a peripheral conductive portion located outside the electrode portion and including an end face of the second transparent electrode layer, a high resistance portion that electrically connects the electrode portion and the peripheral conductive portion, the high resistance portion having a higher resistance per unit area than the electrode portion, and a non-conductive portion that extends linearly and separates the electrode portion, the peripheral conductive portion, and the high resistance portion.

[0012] According to the above configuration, the electric field strength near the edges of the light controlling sheet is further weakened, which further reduces the occurrence of ion migration between the edges of the transparent electrode layer.

[0013] In the above configuration, the first transparent electrode layer may contain indium tin oxide or silver. Generally, when a transparent electrode layer contains silver, tin, or indium, ion migration is likely to occur. According to the above configuration, even if the transparent electrode layer contains a material that is likely to cause ion migration, the occurrence of ion migration can be appropriately suppressed, thereby reducing the drawbacks of transparent electrode layers made of these materials and achieving significant advantages such as high versatility and low resistance.

[0014] A light-controlling sheet that solves the above problem is a light-controlling sheet comprising a light-controlling layer containing a liquid crystal composition and a pair of transparent electrode layers, a first transparent electrode layer and a second transparent electrode layer, sandwiching the light-controlling layer. When viewed from a position facing the surface of the light-controlling sheet, the first transparent electrode layer comprises an electrode portion to which a driving voltage is applied and a peripheral conductive portion located outside the electrode portion and including an end face of the first transparent electrode layer. The potential difference between the first transparent electrode layer and the second transparent electrode layer at the portion where the electrode portion is located is an electrode potential difference. A potential difference that follows the electrode potential difference is applied between the first transparent electrode layer and the second transparent electrode layer at the portion where the peripheral conductive portion is located. The potential difference at the portion where the peripheral conductive portion is located is a peripheral potential difference. When the driving voltage is applied, the peripheral potential difference may be 1 / 10 or less of the electrode potential difference.

[0015] According to the above configuration, when a driving voltage is applied, the electric field strength near the edges of the light controlling sheet is sufficiently weak, thereby making it possible to suppress the occurrence of ion migration between the edges of the transparent electrode layer. [Effects of the Invention]

[0016] According to the present invention, it is possible to suppress the occurrence of ion migration between the ends of the transparent electrode layer. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is a diagram showing a planar structure of a light controlling sheet according to an embodiment. [Figure 2] FIG. 2 is a diagram showing a cross-sectional structure taken along line II-II in FIG. [Figure 3] FIG. 3 is a diagram showing a planar structure of a first transparent electrode layer in the embodiment. [Figure 4] FIG. 3 is a diagram showing the planar structure of a second transparent electrode layer in the embodiment. [Figure 5] FIG. 2 is a diagram showing a cross-sectional structure taken along line VV in FIG. [Figure 6] FIG. 2 is a diagram showing a cross-sectional structure taken along line VI-VI in FIG. [Figure 7]10A and 10B are diagrams showing modified examples of the light controlling sheet according to the embodiment. [Figure 8] FIG. 10 is a diagram showing the planar structure of the second transparent electrode layer of the above-mentioned modified example. [Figure 9] FIG. 10 is a diagram showing the planar structure of a second transparent electrode layer according to another modified example. [Figure 10] FIG. 10 is a diagram showing the planar structure of a second transparent electrode layer according to another modified example. [Figure 11] FIG. 10 is a diagram showing the planar structure of a second transparent electrode layer according to another modified example. [Figure 12] FIG. 10 is a diagram showing a planar structure of a first transparent electrode layer according to another modified example. [Figure 13] FIG. 10 is a diagram showing a planar structure of a first transparent electrode layer according to another modified example. [Figure 14] FIG. 10 is a diagram showing a planar structure of a first transparent electrode layer according to another modified example. [Figure 15] FIG. 10 is a diagram showing the planar structure of a light-controlling sheet of a test example. [Figure 16] FIG. 10 is a diagram showing the cross-sectional structure of a light-controlling sheet of a test example. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of a light controlling sheet will be described with reference to the drawings. [Configuration of light control sheet] As shown in Figure 1, the light-controlling sheet 10 comprises a sheet body 20 which is a layered body including a light-controlling layer and a pair of transparent electrode layers, a sealing portion 50 which seals the ends of the sheet body 20, and a first wiring portion 60 and a second wiring portion 61 for applying a driving voltage to the sheet body 20.

[0019] The sheet body 20 has a first surface 11F which is the front surface of the light controlling sheet 10, and a second surface 11R which is the surface opposite to the first surface 11F. When viewed from a position facing the first surface 11F, the sheet body 20 has a light controlling region 70, a peripheral region 71, a first connection region 72, and a second connection region 73.

[0020] The light control region 70 is a region that spreads from the central part of the main sheet body 20, and the light transmittance of the light control region 70 changes depending on the state of application of a drive voltage to the main sheet body 20. The peripheral region 71 is a region located on the periphery of the light control region 70.

[0021] A first wiring portion 60 is connected to the first connection region 72, and a second wiring portion 61 is connected to the second connection region 73. The first wiring portion 60 is a wiring for applying a voltage to one of a pair of transparent electrode layers, and the second wiring portion 61 is a wiring for applying a voltage to the other of the pair of transparent electrode layers. Each connection region 72, 73 is located at an end of the sheet main body 20. For example, the first connection region 72 and the second connection region 73 are aligned along one side of the rectangular sheet main body 20.

[0022] The sealing portion 50 covers the sheet body 20 in the outer peripheral region 71 and each of the connection regions 72 and 73 . In the drawings, the sizes of the outer peripheral region 71 and the connection regions 72 and 73 are exaggerated relative to the light control region 70, and in FIG. 1, the region where the sealing portion 50 is located is indicated by dots.

[0023] FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, showing the cross-sectional structure of the light controlling sheet 10 in the light controlling region 70 and the peripheral region 71. As shown in FIG. The sheet main body 20 includes a light-controlling layer 21, a first transparent electrode layer 22, a second transparent electrode layer 23, a first transparent support layer 24, and a second transparent support layer 25. The light-controlling layer 21 is sandwiched between the first transparent electrode layer 22 and the second transparent electrode layer 23, and is in contact with these transparent electrode layers 22, 23. The first transparent support layer 24 supports the first transparent electrode layer 22 on the side opposite the light-controlling layer 21 with respect to the first transparent electrode layer 22. The second transparent support layer 25 supports the second transparent electrode layer 23 on the side opposite the light-controlling layer 21 with respect to the second transparent electrode layer 23.

[0024] The light-controlling layer 21 includes a transparent polymer layer and a liquid crystal composition. The transparent polymer layer has voids into which the liquid crystal composition is filled, and the liquid crystal composition is held in the voids. The liquid crystal composition includes liquid crystal molecules. Known materials can be used as the liquid crystal molecules. Examples of the liquid crystal molecules include 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 liquid crystal molecules. In addition to the above-mentioned liquid crystal molecules, the liquid crystal composition may also include a dichroic dye or the like.

[0025] The structure of the transparent polymer layer and the type of liquid crystal composition retention are, for example, a polymer network type, a polymer dispersion type, and a capsule type. The polymer network type light control layer 21 has a polymer network with a three-dimensional mesh structure. The polymer network is an example of a transparent polymer layer, and the liquid crystal composition is retained in the interconnected mesh-like voids in the polymer network. The polymer dispersion type light control layer 21 has a transparent polymer layer that partitions a large number of isolated voids, and the liquid crystal composition is retained in the voids dispersed in the transparent polymer layer. The capsule type light control layer 21 retains the liquid crystal composition in the voids within capsules dispersed in the transparent polymer layer.

[0026] Each of the first transparent electrode layer 22 and the second transparent electrode layer 23 is formed from a conductive material and is transparent to light in the visible region. Known materials can be used for the transparent electrode layers 22 and 23. Examples of materials for the transparent electrode layers 22 and 23 include indium tin oxide, fluorine-doped tin oxide, tin oxide, zinc oxide, carbon nanotubes, poly(3,4-ethylenedioxythiophene), silver, and silver alloys.

[0027] Each of the first transparent support layer 24 and the second transparent support layer 25 is a substrate that is transparent to light in the visible region. Known materials can be used for the transparent support layers 24, 25. The material for the transparent support layers 24, 25 may be a synthetic resin or an inorganic compound. Examples of synthetic resins include polyester, polyacrylate, polycarbonate, polyolefin, etc. Examples of polyesters include polyethylene terephthalate, polyethylene naphthalate, etc. Examples of polyacrylates include polymethyl methacrylate, etc. Examples of inorganic compounds include silicon dioxide, silicon oxynitride, silicon nitride, etc.

[0028] The first surface 11F of the sheet main body 20 is the surface of the first transparent support layer 24 opposite to the surface that contacts the first transparent electrode layer 22. The second surface 11R of the sheet main body 20 is the surface of the second transparent support layer 25 opposite to the surface that contacts the second transparent electrode layer 23. The second surface 11R is attached to a transparent plate made of glass, resin, or the like via an adhesive layer. Examples of transparent plates include window glass found in various buildings such as homes, stations, and airports, partitions installed in offices, show windows installed in stores, and window glass or windshields found in moving objects such as vehicles and aircraft. The surface of the transparent plate may be flat or curved.

[0029] When viewed from a position facing the first surface 11F, the second laminate 27, which is a laminate of the second transparent electrode layer 23 and the second transparent support layer 25, extends to the outside of the first laminate 26, which is a laminate of the light-switching layer 21, the first transparent electrode layer 22, and the first transparent support layer 24. The sealing portion 50 covers the end faces of the first laminate 26 on the second laminate 27, and also extends onto the first laminate 26 to cover the end faces of the first surface 11F. In other words, the end faces of the light-switching layer 21, the first transparent electrode layer 22, and the first transparent support layer 24 are covered by the sealing portion 50.

[0030] Known resin materials can be used as the material for the sealing portion 50. Examples of the material for the sealing portion 50 include epoxy resins, urethane resins, acrylic resins, vinyl acetate resins, ene-thiol resins, and silicone resins.

[0031] The first transparent electrode layer 22 includes an electrode portion 30, a peripheral conductive portion 31, a non-conductive portion 32, and a high-resistance portion 33. These portions are aligned in the direction in which the first transparent electrode layer 22 extends, in other words, along the first surface 11F. The electrode portion 30, the peripheral conductive portion 31, and the high-resistance portion 33 are each conductive. The non-conductive portion 32 is not conductive. The non-conductive portion 32 is a portion in which the conductive film, which is the material of the first transparent electrode layer 22, has lost its conductivity due to destruction or modification of the conductive film, for example, by laser irradiation. On the other hand, the electrode portion 30, the peripheral conductive portion 31, and the high-resistance portion 33 are portions in which the conductive film is not destroyed or modified.

[0032] When viewed from a position facing the first surface 11F, the electrode section 30 is located in the dimming region 70 and the first connection region 72, and the peripheral conductive section 31, the non-conductive section 32, and the high resistance section 33 are located in the peripheral region 71. Note that a portion of the peripheral region 71 does not have to be covered by the sealing section 50. For example, when viewed from a position facing the first surface 11F, the non-conductive section 32 and the high resistance section 33 may be located in a region exposed from the sealing section 50.

[0033] The arrangement of the above-mentioned components in the first transparent electrode layer 22 will be described in detail with reference to Fig. 3. Fig. 3 is a view of a laminate of the first transparent electrode layer 22 and the first transparent support layer 24, viewed from the side where the first transparent electrode layer 22 is located. Fig. 3 also illustrates the first wiring component 60 connected to the first transparent electrode layer 22. The configuration described below is the configuration as viewed from a position facing the surface of the first transparent electrode layer 22, and this configuration is also common when viewed from a position facing the first face 11F.

[0034] The electrode section 30 is located in a region including the central portion of the first transparent electrode layer 22, and the peripheral conductive section 31 is located outside the electrode section 30. The end face located on the outer edge of the first transparent electrode layer 22 is included in the peripheral conductive section 31. The non-conductive section 32 is located between the electrode section 30 and the peripheral conductive section 31.

[0035] The non-conductive portion 32 extends linearly to separate the electrode portion 30 and the peripheral conductive portion 31. The ends of the non-conductive portion 32 are not connected, and a partition portion 34a including one end of the non-conductive portion 32 and a partition portion 34b including the other end of the non-conductive portion 32 extend parallel to each other along the outer edge of the first transparent electrode layer 22. In the example shown in FIG. 3 , the partition portion 34a is located inside the partition portion 34b. A long and narrow high resistance portion 33 is defined between the partition portions 34a and 34b. In other words, the high resistance portion 33 is a strip-shaped portion sandwiched between the partition portions 34a and 34b, which are the two linear portions of the non-conductive portion 32.

[0036] In the region where the high resistance portion 33 is located from the electrode portion 30 toward the outer edge of the first transparent electrode layer 22, the electrode portion 30, non-conductive portion 32 (partition portion 34a), high resistance portion 33, non-conductive portion (partition portion 34b), and peripheral conductive portion 31 are arranged in this order. The high resistance portion 33 is located between the electrode portion 30 and the peripheral conductive portion 31, and is connected to both the electrode portion 30 and the peripheral conductive portion 31. In detail, one end of the high resistance portion 33 in the extension direction is connected to the electrode portion 30, and the other end of the high resistance portion 33 in the extension direction is connected to the peripheral conductive portion 31. In the region from the electrode section 30 toward the outer edge of the first transparent electrode layer 22 where the high resistance section 33 is not located, the electrode section 30, the non-conductive section 32, and the peripheral conductive section 31 are arranged in this order.

[0037] A first wiring portion 60 is connected to the electrode portion 30. That is, the first wiring portion 60 is connected to the first transparent electrode layer 22 inside the non-conductive portion 32. In the laminate of the first transparent electrode layer 22 and the first transparent support layer 24, a portion corresponding to the second connection region 73 is cut out. As described above, in the first transparent electrode layer 22, the conductive electrode portion 30, the peripheral conductive portion 31, and the high resistance portion 33 are separated by the non-conductive portion 32.

[0038] Fig. 4 is a diagram showing an example of the second transparent electrode layer 23, and is a diagram showing a laminate of the second transparent electrode layer 23 and the second transparent support layer 25, viewed from the side where the second transparent electrode layer 23 is located. Fig. 4 also shows a second wiring portion 61 connected to the second transparent electrode layer 23.

[0039] The second transparent electrode layer 23 does not have a structure in which conductive portions are separated by non-conductive portions, as in the first transparent electrode layer 22. The second transparent electrode layer 23 is a uniform conductive film, and is conductive as a whole. That is, the entire second transparent electrode layer 23 is the electrode portion 40. A second wiring portion 61 is connected to the electrode portion 40. In the laminate of the second transparent electrode layer 23 and the second transparent support layer 25, a portion corresponding to the first connection region 72 is cut out.

[0040] Fig. 5 is a cross-sectional view taken along line VV in Fig. 1, showing the cross-sectional structure in the vicinity of first connection region 72. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 1, showing the cross-sectional structure in the vicinity of second connection region 73.

[0041] 5, a laminate of the first transparent electrode layer 22 and the first transparent support layer 24 extends in the first connection region 72, and the first transparent electrode layer 22 is exposed from the light-controlling layer 21 in the first connection region 72. A first wiring section 60 is connected to this exposed first transparent electrode layer 22. The first wiring section 60 includes a conductive adhesive layer 62 bonded to the first transparent electrode layer 22, and a wiring substrate 63 bonded to the conductive adhesive layer 62. The portion where the first wiring section 60 is connected to the first transparent electrode layer 22 and the portion around the first wiring section 60 where the first transparent electrode layer 22 is exposed from the light-controlling layer 21 are covered with a sealing section 50.

[0042] 6, a laminate of the second transparent electrode layer 23 and the second transparent support layer 25 extends in the second connection region 73, and the second transparent electrode layer 23 is exposed from the light-controlling layer 21 in the second connection region 73. A second wiring section 61 is connected to this exposed second transparent electrode layer 23. The second wiring section 61 includes a conductive adhesive layer 64 bonded to the second transparent electrode layer 23 and a wiring substrate 65 bonded to the conductive adhesive layer 64. The portion where the second wiring section 61 is connected to the second transparent electrode layer 23 and the portion around the second wiring section 61 where the second transparent electrode layer 23 is exposed from the light-controlling layer 21 are covered with a sealing section 50.

[0043] The conductive adhesive layers 62 and 64 are 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. The wiring boards 63 and 65 are, for example, flexible printed circuits (FPC). Each of the first wiring portion 60 and the second wiring portion 61 may have a structure in which a conductive material such as a conductive tape and a conductor are joined by soldering.

[0044] The first wiring section 60 and the second wiring section 61 are connected to a drive circuit that generates a drive voltage. A voltage signal is applied to the electrode section 30 of the first transparent electrode layer 22 through the first wiring section 60, and a voltage signal is applied to the electrode section 40 of the second transparent electrode layer 23 through the second wiring section 61.

[0045] In the dimming region 70, the dimming layer 21 changes the orientation of the liquid crystal molecules in response to a change in the voltage generated between the two electrode units 30 and 40. The change in orientation of the liquid crystal molecules changes the degree of scattering, absorption, and transmission of visible light that enters the dimming layer 21.

[0046] Specifically, when no drive voltage is applied to the electrode units 30 and 40, the orientation of the long axes of the liquid crystal molecules is irregular. As a result, the degree of scattering of light incident on the light-controlling layer 21 increases, and the light-controlling region 70 appears cloudy. In other words, when no drive voltage is applied, the light-controlling region 70 is opaque. On the other hand, when a drive voltage is applied to the electrode units 30 and 40 and a potential difference of a predetermined value or greater occurs between these electrode units 30 and 40, the liquid crystal molecules are oriented, and the long axes of the liquid crystal molecules are oriented along the electric field direction between the electrode units 30 and 40. As a result, light is more easily transmitted through the light-controlling layer 21, and the light-controlling region 70 becomes transparent.

[0047] Here, in the first transparent electrode layer 22, the electrode units 30, the high-resistance units 33, and the peripheral conductive units 31 are electrically connected to one another. Meanwhile, the resistance of the high-resistance units 33, which are narrower than the electrode units 30, is high. The electrode units 30 and the peripheral conductive units 31 are electrically connected via the high-resistance units 33, which inhibits the transfer of charge from the electrode units 30 to the peripheral conductive units 31. As a result, when a driving voltage is applied, the potential difference between the first transparent electrode layer 22 and the second transparent electrode layer 23 near the edge of the first transparent electrode layer 22 is smaller than when the first transparent electrode layer 22 does not have the non-conductive units 32 and the high-resistance units 33. In this configuration, the electric field strength is weaker near the edge of the sheet body 20 than in the dimming region 70 where the electrode units 30 and 40 are located.

[0048] The stronger the electric field strength, the more accelerated the occurrence of ion migration. In contrast, in this embodiment, the electric field strength near the end face of the sheet main body 20 is weaker than when the first transparent electrode layer 22 does not have the non-conductive portion 32 and the high-resistance portion 33. Therefore, even if moisture adhering to the end face of the sheet main body 20 before the formation of the sealing portion 50 remains, or even if moisture penetrates the sealing portion 50 and adheres to the end face of the sheet main body 20, the occurrence of ion migration between the ends of the transparent electrode layers 22, 23 can be suppressed.

[0049] Furthermore, the likelihood of ion migration varies depending on the type of metal element contained in the transparent electrode layers 22, 23. Specifically, ion migration is most likely to occur when the transparent electrode layers 22, 23 contain silver (Ag), and is also likely to occur when the transparent electrode layers 22, 23 contain tin (Sn) or indium (In). Indium tin oxide is widely used as a material for transparent conductive films, and stacked films containing silver have attracted attention as low-resistance transparent conductive films. With the light-control sheet 10 of this embodiment, even when the transparent electrode layers 22, 23 are made of indium tin oxide or silver, the occurrence of ion migration can be suppressed, and the advantages of the transparent electrode layers 22, 23 made of these materials can be greatly obtained.

[0050] In order to effectively suppress the occurrence of ion migration, when the potential difference between the first transparent electrode layer 22 and the second transparent electrode layer 23 at the portion where the electrode portion 30 is located is defined as the electrode potential difference, and the potential difference between the first transparent electrode layer 22 and the second transparent electrode layer 23 at the portion where the peripheral conductive portion 31 is located is defined as the peripheral potential difference, it is preferable that the peripheral potential difference be 1 / 10 or less of the electrode potential difference when a driving voltage is applied.

[0051] Since the peripheral conductive portion 31 is not insulated from the electrode portion 30, the peripheral potential difference changes in accordance with the electrode potential difference. That is, when the electrode potential difference increases, the peripheral potential difference also increases, and when the electrode potential difference decreases, the peripheral potential difference also decreases.

[0052] The width and length of the high resistance portion 33 may be set so that the high resistance portion 33 has a resistance value necessary for the peripheral potential difference to be 1 / 10 or less of the electrode potential difference. The width of the peripheral conductive portion 31 is, for example, 10 μm or more and 5 mm or less, and the width of the non-conductive portion 32 is, for example, 1 μm or more and 100 μm or less.

[0053] The non-conductive portion 32 can be suitably formed by laser irradiation of a laminate including the light-controlling layer 21, a transparent conductive film that will become the transparent electrode layers 22 and 23, and the transparent support layers 24 and 25. By using laser irradiation, the non-conductive portion 32 can be formed in the transparent conductive film that is the underlying layer without destroying the transparent electrode layers 22 and 23. Because the ends of the non-conductive portion 32 in this embodiment are spaced apart from each other, it is possible to reduce the burden required to ensure the accuracy of the position at which the non-conductive portion 32 is formed, compared to forming the non-conductive portion 32 in a ring shape by connecting the ends of thin wire-shaped non-conductive portions 32 together.

[0054] [Modification of the second transparent electrode layer] 7 to 11, modified examples of the second transparent electrode layer 23 when the first transparent electrode layer 22 has the configuration shown in FIG. 3 will be described.

[0055] As shown in FIG. 7 , the second transparent electrode layer 23 may have a high resistance portion 43 at a position that overlaps the high resistance portion 33 of the first transparent electrode layer 22 when viewed from a position facing the first surface 11F. That is, the second transparent electrode layer 23 includes a conductive electrode portion 40, a peripheral conductive portion 41, a high resistance portion 43, and a non-conductive portion 42 that does not have conductivity. As shown in FIG. 8 , the non-conductive portion 42 extends linearly to separate the electrode portion 40 from the peripheral conductive portion 41 located outside it. An elongated high resistance portion 43 is defined between the two linear portions of the non-conductive portion 42. One end of the high resistance portion 43 in the extension direction is connected to the electrode portion 40, and the other end of the high resistance portion 43 in the extension direction is connected to the peripheral conductive portion 41.

[0056] When viewed from a position facing the first surface 11F, part or all of the non-conductive portion 42 may or may not overlap with the non-conductive portion 32 of the first transparent electrode layer. If the non-conductive portion 42 and the non-conductive portion 32 overlap, these non-conductive portions 32, 42 can be formed collectively by using laser irradiation.

[0057] According to the above configuration, in the second transparent electrode layer 23 as well, the electrode portions 40 and the peripheral conductive portions 41 are electrically connected via the high resistance portions 43, which are high resistance portions, and therefore the movement of charges from the electrode portions 40 to the peripheral conductive portions 41 is inhibited. As a result, compared to when the second transparent electrode layer 23 does not have the non-conductive portions 42 and the high resistance portions 43, the electric field strength near the end faces of the sheet main body 20 is weaker, and the occurrence of ion migration between the ends of the transparent electrode layers 22, 23 can be further suppressed.

[0058] 9, the second transparent electrode layer 23 may have a high resistance portion 43 at a position that does not overlap with the high resistance portion 33 of the first transparent electrode layer 22 when viewed from a position facing the first surface 11F. The second transparent electrode layer 23 may also have two or more high resistance portions 43. In the example shown in Fig. 9, the second transparent electrode layer 23 has two high resistance portions 43a, 43b, and the high resistance portions are located along each of two opposing sides of the substantially rectangular second transparent electrode layer 23.

[0059] Specifically, the second transparent electrode layer 23 has two non-conductive portions 42a, 42b spaced apart from each other, and a partition 44a including one end of the first non-conductive portion 42a and a partition 44b including one end of the second non-conductive portion 42b extend parallel to each other along the outer edge of the second transparent electrode layer 23. A first high resistance portion 43a is defined between the partitions 44a and 44b. A partition 44c including the other end of the first non-conductive portion 42a and a partition 44d including the other end of the second non-conductive portion 42b extend parallel to each other along the outer edge of the second transparent electrode layer 23. A second high resistance portion 43b is defined between the partitions 44c and 44d.

[0060] Even with the above configuration, the electrode portion 40 and the peripheral conductive portion 41 are electrically connected via the high-resistance portions 43a and 43b, so the electric field strength near the end faces of the sheet body 20 is weaker than when the second transparent electrode layer 23 does not have the non-conductive portions 42a and 42b and the high-resistance portions 43a and 43b. Therefore, the occurrence of ion migration between the ends of the transparent electrode layers 22 and 23 is suppressed.

[0061] The second transparent electrode layer 23 may have one high resistance portion 43, and this high resistance portion 43 may be located at a position that does not overlap with the high resistance portion 33 of the first transparent electrode layer 22. The first transparent electrode layer 22 may also have two or more high resistance portions 33.

[0062] 10, the second transparent electrode layer 23 may have a closed-ring-shaped non-conductive portion 42. In this case, the second transparent electrode layer 23 does not have a high-resistance portion 43, and the electrode portion 40 and the peripheral conductive portion 41 are completely separated by the non-conductive portion 42. In other words, the electrode portion 40 and the peripheral conductive portion 41 are insulated from each other.

[0063] According to the above configuration, the potential of the peripheral conductive portion 41 is in a floating state, and therefore, changes in the potential of the peripheral conductive portion 41 are suppressed even when a drive voltage is applied to the electrode portion 40. This also weakens the electric field strength near the end face of the sheet body 20 compared to when the second transparent electrode layer 23 does not have the non-conductive portion 42, and therefore, the occurrence of ion migration between the ends of the transparent electrode layers 22, 23 is suppressed.

[0064] 11 , in the second transparent electrode layer 23, the non-conductive portion 42 may extend along the outer edge of the second transparent electrode layer 23 around the portion corresponding to the first connection region 72, i.e., the portion of the sheet main body 20 where the first wiring portion 60 is arranged. The non-conductive portion 42 defines an end conductive portion 45 along the outer edge of the second transparent electrode layer 23 so as to surround the first connection region 72. In the portion other than the end conductive portion 45, the electrode portion 40 extends to the outer edge of the second transparent electrode layer 23, and the electrode portion 40 and the end conductive portion 45 are insulated by being separated by the non-conductive portion 42.

[0065] According to the above configuration, the potential of the end conductive portion 45 is in a floating state, and therefore, when a drive voltage is applied, the electric field strength is weaker around the first connection region 72 compared to when the second transparent electrode layer 23 does not have the non-conductive portion 42. When a drive voltage is applied, the actual voltage applied to the transparent electrode layers 22, 23 tends to be greatest around the wiring portions 60, 61. Therefore, when the non-conductive portion 42 is not provided, ion migration is likely to occur around the first wiring portion 60. Therefore, by floating the portion along the outer edge of the second transparent electrode layer 23 around the first wiring portion 60, the occurrence of ion migration can be effectively suppressed.

[0066] [Modification of the first transparent electrode layer] Modified examples of the arrangement of the high resistance portions 33 in the first transparent electrode layer 22 will be described with reference to FIGS.

[0067] When viewed from a position facing the surface of the first transparent electrode layer 22, the high resistance portion 33 does not have to extend linearly along the outer edge of the first transparent electrode layer 22, and may have a zigzag shape as shown in Fig. 12. In detail, the partitions 34a and 34b have a zigzag shape with a constant gap between them, and the high resistance portion 33 is defined between the partitions 34a and 34b. As long as the high resistance portion 33 has a higher resistance per unit area than the electrode portion 30, the high resistance portion 33 may extend in a curved shape, and the width of the high resistance portion 33 may not be constant.

[0068] 13, each of the linear portions of the non-conductive portion 32 sandwiching the high resistance portion 33 does not have to be a single continuous line; that is, there may be a break in the middle of the linear portion. The high resistance portion 33 can be formed by arranging another linear portion on the outside or inside of the break in a linear portion. In the example shown in FIG. 13, the non-conductive portion 32 is positioned in a ring shape with a break, and a linear non-conductive portion 32 extending along the outer edge of the first transparent electrode layer 22 is positioned outside this break and its vicinity. Even with this configuration, a band-like high resistance portion 33 is defined between the inner non-conductive portion 32 and the outer non-conductive portion 32.

[0069] Furthermore, as long as the arrangement of the non-conductive portions 32 forms high-resistance portions 33 having a higher resistance per unit area than the electrode portion 30, the high-resistance portions 33 do not have to be sandwiched between two linear portions extending in parallel. Specifically, as shown in FIG. 14 , the non-conductive portions 32 may be positioned intermittently along the outer edge of the first transparent electrode layer 22. In other words, the non-conductive portions 32 may have a ring shape made up of dotted lines. In such a configuration, the gaps between the intermittently arranged non-conductive portions 32 function as the high-resistance portions 33.

[0070] [Test example] Tests were conducted to determine the configuration of the high resistance portion required to make the peripheral potential difference 1 / 10 or less of the electrode potential difference.

[0071] 15 and 16 show the configuration of the light-controlling sheet used in the test. As shown in the plan view of FIG. 15, the light-controlling sheet is formed so that the transparent electrode layer has a high-resistance portion 110 between two terminal connection portions 100, 101, the high-resistance portion 110 being narrower than the terminal connection portions 100, 101. For simplicity, non-conductive portions around the high-resistance portion 110 are not shown. As shown in the cross-sectional view of FIG. 16, the light-controlling sheet includes a light-controlling layer 140, transparent electrode layers 141, 142 having the above-described configuration, and transparent support layers 143, 144. The high-resistance portion 110 of the first transparent electrode layer 141 faces the high-resistance portion 110 of the second transparent electrode layer 142, sandwiching the light-controlling layer 140 therebetween.

[0072] Input terminals 120, 121 are connected to the transparent electrode layers 141, 142 where one terminal connection portion 100 is located, and an AC voltage Vo is applied between these input terminals 120, 121. The applied voltage Vo is 80 V and has a frequency of 40 Hz. Measurement terminals 130, 131 are connected to the transparent electrode layers 141, 142 where the other terminal connection portion 101 is located, and a measurement voltage Vt, which is the voltage between these measurement terminals 130, 131, is measured.

[0073] In the above configuration, the portions where the input terminals 120, 121 are located correspond to the portions where the electrode portions 30, 40 are located in the above embodiment, and the portions where the measurement terminals 130, 131 are located correspond to the portions where the outer conductive portions 31, 41 are located in the above embodiment.

[0074] The length Lt of the high resistance section 110 was 10 cm, and the width Wt of the high resistance section 110 was changed to measure the measured voltage Vt and calculate the resistance value R of the high resistance section 110. The transparent electrode layers 141 and 142 were made of indium tin oxide, and the sheet resistance value ρs of the transparent electrode layers 141 and 142 was 130 Ω / sq. The resistance value R was calculated using the formula R=ρs×Lt / Wt. The results are shown in Table 1.

[0075] [Table 1]

[0076] As shown in Table 1, when the width Wt is smaller than 0.1 cm, the measured voltage Vt drops sharply. When the width Wt is 0.05 cm, i.e., 0.5 mm, the measured voltage Vt is 1 / 10 or less of the applied voltage Vo, and the resistance value R at this time is 26 kΩ. From this result, it was confirmed that in order to make the potential difference applied to the input terminals 120 and 121 1 / 10 at the measurement terminals 130 and 131, the resistance value of the high resistance section 110 needs to be 26 kΩ or more.

[0077] As described above, according to this embodiment, the following effects can be obtained. (1) In the first transparent electrode layer 22, the electrode portion 30 and the peripheral conductive portion 31 are electrically connected by the high resistance portion 33. Therefore, the electric field strength near the end face of the sheet body 20 is weakened, and the occurrence of ion migration can be suppressed.

[0078] (2) When a driving voltage is applied, the peripheral potential difference, which is the potential difference at the portion where the peripheral conductive portion 31 is located, is 1 / 10 or less of the electrode potential difference, which is the potential difference at the portion where the electrode portion 30 is located. As a result, the electric field strength near the end face of the sheet main body 20 is sufficiently weakened, making it possible to suppress the occurrence of ion migration.

[0079] (3) If the high resistance portion 33 has a strip shape sandwiched between two linear portions included in the non-conductive portion 32, the high resistance portion 33 can be suitably realized as having a high resistance. (4) If the high resistance portion 33 extends linearly, it is easy to design the shape and resistance of the high resistance portion 33.

[0080] (5) In the second transparent electrode layer 23, if the electrode portion 40 and the peripheral conductive portion 41 are electrically connected by the high resistance portion 43, the electric field strength near the end face of the sheet body 20 is weakened. Therefore, the occurrence of ion migration can be further suppressed.

[0081] (6) Even when the transparent electrode layers 22, 23 contain indium tin oxide or silver, which are materials that easily cause ion migration, the light controlling sheet 10 of the above embodiment can effectively suppress the occurrence of ion migration. Therefore, the drawbacks of the transparent electrode layers 22, 23 made of these materials are reduced, and the advantages of high versatility and low resistance can be obtained.

[0082] [Variations] The above embodiment can be modified as follows: The following modifications may also be combined with each other.

[0083] The sheet body 20 may include a first alignment layer and a second alignment layer. The first alignment layer is located between the light control layer 21 and the first transparent electrode layer 22 and is in contact with these layers. The second alignment layer is located between the light control layer 21 and the second transparent electrode layer 23 and is in contact with these layers.

[0084] Each of the first alignment layer and the second alignment layer 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 21. The material of each of the first alignment layer and the second alignment layer is an organic compound, an inorganic compound, or a mixture thereof. Examples of organic compounds include polyimide, polyamide, polyvinyl alcohol, and cyanide compounds. Examples of inorganic compounds include silicon oxide and zirconium oxide. The material of the first alignment layer and the second alignment layer may be silicone. Silicone is a compound having both inorganic and organic portions.

[0085] When the sheet body 20 includes a first alignment layer and a second alignment layer, in the dimming region 70, when no drive voltage is applied to the electrode units 30 and 40, the long axis direction of the liquid crystal molecules is oriented along the thickness direction of the dimming layer 21. Therefore, the dimming region 70 is transparent. On the other hand, when a drive voltage is applied to the electrode units 30 and 40, the long axis direction of the liquid crystal molecules is oriented to intersect with the thickness direction of the dimming layer 21. Therefore, the dimming region 70 appears cloudy and opaque.

[0086] In the above embodiment, the second surface 11R of the sheet body 20 is attached to the transparent plate, but instead, the first surface 11F may be attached to the transparent plate. In the above embodiment, a laminate of the second transparent electrode layer 23 and the second transparent support layer 25 protrudes from the end of the sheet main body 20, and the sealing portion 50 is arranged from above this laminate toward the first surface 11F. The structure of the sheet main body 20 in the portion where the sealing portion 50 is arranged is not limited to this. At the end of the sheet main body 20, the end faces of the light control layer 21, the transparent electrode layers 22, 23, and the transparent support layers 24, 25 may be aligned, and the sealing portion 50 may be arranged to cover the entire end face of each layer. Furthermore, the sealing portion 50 may not be provided. [Explanation of symbols]

[0087] 10...Light-adjusting sheet 11F…First page 11R…Second side 20...Seat body 21...Photochromic layer 22,23...Transparent electrode layer 24,25...Transparent support layer 30,40…electrode part 31, 41...Outer conductive part 32, 42...Non-conductive parts 33,43…High resistance part 60,61...Wiring section 70...Dimmer area 71...Outer area 72, 73...Connection area

Claims

1. a light-controlling layer containing a liquid crystal composition; a pair of transparent electrode layers, a first transparent electrode layer and a second transparent electrode layer, sandwiching the light control layer; A light control sheet comprising: When viewed from a position facing the surface of the light controlling sheet, the first transparent electrode layer an electrode portion to which a driving voltage is applied; a peripheral conductive portion located outside the electrode portion and including an end surface of the first transparent electrode layer; a high resistance portion electrically connecting the electrode portion and the outer peripheral conductive portion, the high resistance portion having a higher resistance per unit area than the electrode portion; a linearly extending non-conductive portion that separates the electrode portion, the outer circumferential conductive portion, and the high resistance portion; Dimming sheet.

2. When viewed from a position opposite to the surface of the light controlling sheet, The high resistance portion has a strip shape sandwiched between two linear portions included in the non-conductive portion. The light-controlling sheet according to claim 1 .

3. When viewed from a position opposite to the surface of the light controlling sheet, The high resistance portion extends linearly. The light-controlling sheet according to claim 2 .

4. When viewed from a position facing the surface of the light controlling sheet, the second transparent electrode layer an electrode portion to which a driving voltage is applied; a peripheral conductive portion located outside the electrode portion and including an end surface of the second transparent electrode layer; a high resistance portion electrically connecting the electrode portion and the outer peripheral conductive portion, the high resistance portion having a higher resistance per unit area than the electrode portion; a linearly extending non-conductive portion that separates the electrode portion, the outer circumferential conductive portion, and the high resistance portion; The light-controlling sheet according to any one of claims 1 to 3.

5. The first transparent electrode layer contains indium tin oxide or silver. The light-controlling sheet according to any one of claims 1 to 4.

6. a light-controlling layer containing a liquid crystal composition; a pair of transparent electrode layers, a first transparent electrode layer and a second transparent electrode layer, sandwiching the light control layer; A light control sheet comprising: When viewed from a position facing the surface of the light controlling sheet, the first transparent electrode layer an electrode portion to which a driving voltage is applied; a peripheral conductive portion located outside the electrode portion and including an end surface of the first transparent electrode layer; a high resistance portion electrically connecting the electrode portion and the outer peripheral conductive portion, the high resistance portion having a higher resistance per unit area than the electrode portion, a potential difference between the first transparent electrode layer and the second transparent electrode layer at a portion where the electrode portion is located is an electrode potential difference, a potential difference that follows the electrode potential difference is applied between the first transparent electrode layer and the second transparent electrode layer at a portion where the peripheral conductive portion is located, and the potential difference at the portion where the peripheral conductive portion is located is a peripheral potential difference, When the driving voltage is applied, the outer periphery potential difference is 1 / 10 or less of the electrode potential difference. Dimming sheet.

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