Light control unit and light control plate

Abstract

This light control unit comprises: a light control sheet having a plurality of light control regions; a first wiring connection part including a first wiring substrate; and a second wiring connection part including a second wiring substrate. The first wiring substrate includes a first electrode layer connection part connected to a first transparent electrode layer, and a first lead wire extending from the first electrode layer connection part. The second wiring substrate includes a plurality of second electrode layer connection parts connected one by one to the respective second transparent electrode layers of the light control regions, and a plurality of second lead wires extending one by one from the respective second electrode layer connection parts. To a terminal part of one of the wiring substrates, a lead wire and an extended line of this wiring substrate extend, and by connecting the first wiring substrate and the second wiring substrate, a lead wire of the other wiring substrate is connected to the extended line.

Description

Dimming unit and dimming plate

[0001] The present disclosure relates to a light control unit including a light control sheet with variable light transmittance, and a light control panel.

[0002] The light-controlling sheet includes 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 compound in the light-controlling layer changes depending on whether or not the driving voltage is applied, making it possible to switch between a transparent state in which light passes through the light-controlling layer and an opaque state in which light transmission through the light-controlling layer is suppressed by scattering or the like.

[0003] In recent years, a light-control sheet has been proposed in which one of the transparent electrode layers is divided into a plurality of regions, allowing each region to be switched between a transparent state and an opaque state (see, for example, Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2020-126153

[0005] The light-controlling sheet is provided with wiring connections for connecting the transparent electrode layer to a power supply. An example of the arrangement of wiring connections for a light-controlling sheet that can be driven in separate regions will be described with reference to FIG.

[0006] 10 , the light controlling sheet 100 includes a first electrode sheet 101 having a first transparent electrode layer, a second electrode sheet 102 having a second transparent electrode layer, and a light controlling layer 103 sandwiched between the first electrode sheet 101 and the second electrode sheet 102. The back surface of the light controlling sheet 100 is attached to a transparent plate 150, or the light controlling sheet 100 is sandwiched between two transparent plates 150.

[0007] The light controlling sheet 100 has a plurality of strip-shaped light controlling regions SL. Between adjacent light controlling regions SL, the first transparent electrode layer of the first electrode sheet 101 is conductive, and the second transparent electrode layer of the second electrode sheet 102 is insulated.

[0008] At the end of the light-adjusting sheet 100, a first wiring connection 110 consisting of a wiring substrate or the like is connected to the first transparent electrode layer of the first electrode sheet 101. Similarly, a second wiring connection 120 is connected to the second transparent electrode layer of the second electrode sheet 102. Because the first transparent electrode layer is conductive between the multiple light-adjusting regions SL, only one first wiring connection 110 is required to be connected to the first transparent electrode layer. On the other hand, because the second transparent electrode layer is insulated between the multiple light-adjusting regions SL, a second wiring connection 120 must be connected to the second transparent electrode layer for each light-adjusting region SL. Therefore, it is difficult to combine the connection regions of the first wiring connection 110 and the second wiring connection 120 in adjacent regions. For example, as shown in FIG. 10 , the first wiring connection 110 is arranged along one side of the light-adjusting sheet 100, and multiple second wiring connection 120 are arranged along the other side of the light-adjusting sheet 100.

[0009] Wires 111 and 121 are connected to the ends of the wiring connection portions 110 and 120, and the wires 111 and 121 are routed outside the transparent plate 150 and connected to a power supply. Wires 121 are connected to each of the multiple second wiring connection portions 120, and these wires 121 are routed. Therefore, compared to when there is only one second wiring connection portion 120 and it is provided in a position close to the first wiring connection portion 110, there is a problem in that a wider area is required outside the transparent plate 150 for routing the wires.

[0010] One aspect of the light-modulating unit is a light-modulating sheet including a light-modulating layer containing a liquid crystal composition, a pair of transparent electrode layers sandwiching the light-modulating layer, the pair being a first transparent electrode layer and a second transparent electrode layer; a first wiring connection portion including a first wiring substrate; and a second wiring connection portion including a second wiring substrate. When viewed from a position facing the surface of the light-modulating sheet, the light-modulating sheet has a plurality of light-modulating regions, and the second transparent electrode layer is insulated between adjacent light-modulating regions. A first conductor portion of the first wiring substrate includes a first electrode layer connection portion connected to the first transparent electrode layer and a first wiring extending from the first electrode layer connection portion. The second conductor portion of the second wiring board includes a plurality of second electrode layer connection portions connected one by one to the second transparent electrode layer of each dimming region, and a plurality of second wiring wires extending one by one from each second electrode layer connection portion, and the target wiring board, which is one of the first wiring board and the second wiring board, has a terminal portion at its end to which a drive voltage is input, and the wiring wires of the target wiring board and extension wires included in the conductor portion of the target wiring board extend to the terminal portion, and by connecting the first wiring board and the second wiring board, the wiring wires of the other of the first wiring board and the second wiring board are connected to the extension wires.

[0011] FIG. 1 is a diagram showing the planar structure of a light control panel of one embodiment. FIG. 2 is a diagram showing the cross-sectional structure of a light control unit taken along line 2-2 in FIG. 1. FIG. 3 is a diagram showing the cross-sectional structure of a light control unit taken along line 3-3 in FIG. 1. FIG. 4 is a diagram showing the planar structure of a light control sheet of one embodiment. FIG. 5 is a diagram showing an enlarged view of a portion of a second wiring connection portion in a light control unit of one embodiment. FIG. 6 is a diagram showing an enlarged view of a portion of a second wiring connection portion in a light control unit of one embodiment. FIG. 7 is a diagram showing an enlarged view of a portion of a second wiring connection portion in a light control unit of one embodiment. FIG. 8 is a diagram showing an enlarged view of a connection portion between a first wiring connection portion and a second wiring connection portion in a light control unit of one embodiment. FIG. 9 is a diagram showing an enlarged view of a portion of a first wiring connection portion in a light control unit of one embodiment. FIG. 10 is a diagram showing the planar structure of a conventional light control panel.

[0012] An embodiment of a light control unit and a light control panel will be described with reference to the drawings. [Configuration of light control unit and light control panel] The overall configuration of a light control unit 10 will be described with reference to Fig. 1. The light control unit 10 includes a light control sheet 11, a first wiring connection portion 12, and a second wiring connection portion 13. The wiring connections 12 and 13 are connected to ends of the light control sheet 11. The first wiring connection portion 12 is connected to one of a pair of transparent electrode layers included in the light control sheet 11, and the second wiring connection portion 13 is connected to the other of the pair of transparent electrode layers.

[0013] The light controlling sheet 11 is fixed to a transparent plate 60 made of glass, resin, or the like. The transparent plate 60 is, for example, window glass provided in various buildings, a partition installed indoors, or a window glass or windshield provided in a moving object such as a vehicle or an airplane. The surface of the transparent plate 60 may be flat or curved.

[0014] The light controlling sheet 11 is fixed to one transparent plate 60 by attaching the back surface of the light controlling sheet 11 to the transparent plate 60. Alternatively, the light controlling sheet 11 may be sandwiched between two transparent plates 60. In other words, the light controlling sheet 11 may be sandwiched between laminated glass, and both the front and back surfaces of the light controlling sheet 11 may be covered with transparent plates 60. In this case, the light controlling sheet 11, together with an intermediate film, is sandwiched between the two transparent plates 60. The light controlling unit 10 and the transparent plates 60 form a light controlling plate 70.

[0015] Fig. 2 is a cross-sectional view of only the light control unit 10 taken along line 2-2 in Fig. 1, and Fig. 3 is a cross-sectional view of only the light control unit 10 taken along line 3-3 in Fig. 1. First, the layer structure of the light control sheet 11 will be described with reference to Figs. 2 and 3.

[0016] The light-controlling sheet 11 includes a light-controlling layer 20, a first transparent electrode layer 21, a second transparent electrode layer 22, a first transparent support layer 23, and a second transparent support layer 24. The light-controlling layer 20 is sandwiched between the first transparent electrode layer 21 and the second transparent electrode layer 22 and is in contact with these transparent electrode layers 21, 22. The first transparent support layer 23 supports the first transparent electrode layer 21 on the side opposite the light-controlling layer 20 with respect to the first transparent electrode layer 21, and the second transparent support layer 24 supports the second transparent electrode layer 22 on the side opposite the light-controlling layer 20 with respect to the second transparent electrode layer 22.

[0017] The side of the first transparent support layer 23 opposite the first transparent electrode layer 21 is the front surface of the light-controlling sheet 11, and the side of the second transparent support layer 24 opposite the second transparent electrode layer 22 is the back surface of the light-controlling sheet 11.

[0018] The detailed structure of each layer will be described below. The light-controlling layer 20 includes a transparent polymer layer and a liquid crystal composition. The transparent polymer layer has voids, which are filled with the liquid crystal composition. The voids may be spherical, ellipsoidal, or irregular in shape.

[0019] The structure of the photochromic layer 20 is either a polymer network type, a polymer dispersion type, or an capsule type. The polymer network type photochromic layer 20 has a polymer network with a three-dimensional mesh structure. The polymer network is an example of a transparent polymer layer, and a liquid crystal composition is held in the voids of the interconnected mesh in the polymer network. The polymer dispersion type photochromic layer 20 has a transparent polymer layer that defines a large number of isolated voids, and the liquid crystal composition is held in the voids dispersed in the transparent polymer layer. The capsule type photochromic layer 20 holds the liquid crystal composition in the voids within capsules dispersed in the transparent polymer layer.

[0020] The transparent polymer layer is a polymer of a photopolymerizable compound. The photopolymerizable compound is, for example, an ultraviolet-polymerizable compound. The ultraviolet-polymerizable compound is, for example, an acrylate compound such as butyl ethyl acrylate or cyclohexyl acrylate, a methacrylate compound such as N,N-dimethylaminoethyl methacrylate or phenoxyethyl methacrylate, a stilbene compound, a diacrylate compound, a dimethacrylate compound, a triacrylate compound, a trimethacrylate compound, a tetraacrylate compound, a tetramethacrylate compound, or an oligomer of each of these compounds. The proportion of the transparent polymer layer to the total mass of the light-controlling layer 20 is preferably 20% by mass or more and 80% by mass or less.

[0021] The liquid crystal composition includes, for example, a liquid crystal compound with positive dielectric anisotropy. That is, the dielectric constant of the liquid crystal compound in the long axis direction is greater than the dielectric constant of the liquid crystal compound in the short axis direction. The liquid crystal compound is, for example, a Schiff base-based, azo-based, azoxy-based, biphenyl-based, terphenyl-based, benzoate ester-based, tolan-based, pyrimidine-based, pyridazine-based, cyclohexanecarboxylic acid ester-based, phenylcyclohexane-based, biphenylcyclohexane-based, dicyanobenzene-based, naphthalene-based, or dioxane-based compound. In addition to the liquid crystal compound, the liquid crystal composition may contain a dichroic dye, a viscosity reducer, an antifoaming agent, an antioxidant, a weathering agent, or the like. Examples of the weathering agent include an ultraviolet absorber and a light stabilizer.

[0022] The photochromic layer 20 may also include spacers dispersed throughout the transparent polymer layer. The spacers define the thickness of the photochromic layer 20 around the spacers, thereby making the thickness of the photochromic layer 20 uniform. The spacers may be bead spacers or photospacers formed by exposing and developing a photoresist.

[0023] Each of the first transparent electrode layer 21 and the second transparent electrode layer 22 is conductive and transparent to light in the visible region. Examples of materials for the transparent electrode layers 21 and 22 include indium tin oxide, fluorine-doped tin oxide, tin oxide, zinc oxide, carbon nanotubes, poly(3,4-ethylenedioxythiophene), silver, and silver alloys.

[0024] Each of the first transparent support layer 23 and the second transparent support layer 24 is a base material that is transparent to light in the visible region. The transparent support layers 23, 24 are made of, for example, a synthetic resin or an inorganic compound. Examples of synthetic resins include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyacrylates such as polymethyl methacrylate, polycarbonates, and polyolefins. Examples of inorganic compounds include silicon dioxide, silicon oxynitride, and silicon nitride.

[0025] Next, the structure near the wiring connections 12 and 13 will be described. As shown in Fig. 2, a first connection area SA is provided at an end along one side of the light-controlling sheet 11. In the first connection area SA, the first transparent electrode layer 21 is exposed from the light-controlling layer 20, the second transparent electrode layer 22, and the second transparent support layer 24. A first connection section 30 of the first wiring connection section 12 is connected to the exposed surface of the first transparent electrode layer 21.

[0026] The first connection portion 30 is composed of a first substrate portion 32 and a first conductive adhesive layer 39. The first substrate portion 32 is a part of the first wiring substrate 31 of the first wiring connection portion 12. The first conductive adhesive layer 39 is bonded to the first transparent electrode layer 21 and the first substrate portion 32 between them. This fixes the first connection portion 30 to the first transparent electrode layer 21, and establishes electrical conduction between the first transparent electrode layer 21 and the conductor portion of the first substrate portion 32. In the first connection region SA, the first transparent electrode layer 21 and the first connection portion 30 may be covered by a first sealing portion 15.

[0027] 3 , a second connection region SB is provided at an end along the other side of the light-controlling sheet 11. In the second connection region SB, the second transparent electrode layer 22 is exposed from the light-controlling layer 20, the first transparent electrode layer 21, and the first transparent support layer 23. A second connection portion 40 of the second wiring connection portion 13 is connected to the exposed surface of the second transparent electrode layer 22.

[0028] The second connection portion 40 is composed of a second substrate portion 42 and a second conductive adhesive layer 49. The second substrate portion 42 is a part of the second wiring substrate 41 of the second wiring connection portion 13. The second conductive adhesive layer 49 is bonded to the second transparent electrode layer 22 and the second substrate portion 42 between them. This fixes the second connection portion 40 to the second transparent electrode layer 22, establishing electrical conduction between the second transparent electrode layer 22 and the conductor portion of the second substrate portion 42. In the second connection region SB, the second transparent electrode layer 22 and the second connection portion 40 may be covered by the second sealing portion 16.

[0029] Each of the first wiring board 31 and the second wiring board 41 has a structure in which a conductor portion made of a metal foil such as copper foil is disposed on a resin base material made of polyimide or the like. The wiring boards 31 and 41 are preferably flexible printed circuit boards (FPCs).

[0030] Each of the first conductive adhesive layer 39 and the second conductive adhesive layer 49 is made of an anisotropic or isotropic conductive material. The conductive adhesive layers 39 and 49 are preferably anisotropic conductive films (ACFs).

[0031] The first sealing portion 15 and the second sealing portion 16 are components of the dimming unit 10. The sealing portions 15 and 16 are formed from a resin such as a photocurable resin or a thermosetting resin. Examples of the resin material for the sealing portions 15 and 16 include polyacrylate resin, epoxy resin, allyl resin, polyurethane resin, and silicone resin.

[0032] The planar structure of the light-controlling sheet 11 will be described with reference to Figure 4. Figure 4 is a plan view of the light-controlling sheet 11 in a state where the wiring connections 12, 13 are not connected. When viewed from a position facing the surface of the light-controlling sheet 11, the light-controlling sheet 11 has multiple light-controlling regions SL and the first connection region SA and second connection region SB described above. The light-controlling regions SL are regions in which the light-controlling layer 20 is sandwiched between the first transparent electrode layer 21 and the second transparent electrode layer 22, and are regions in which the light transmittance is variable.

[0033] When viewed from a position facing the surface of the light controlling sheet 11, the light controlling sheet 11 has a first side L1 and a second side L2 extending in a direction intersecting the first side L1. For example, if the light controlling sheet 11 has a substantially rectangular shape, the first side L1 and the second side L2 extend in directions perpendicular to each other. The multiple light controlling regions SL are arranged so that the ends of the light controlling regions SL are aligned along the direction in which the second side L2 extends. For example, the light controlling region SL has a strip shape extending in the same direction as the first side L1, and the multiple light controlling regions SL are aligned along the direction in which the second side L2 extends.

[0034] A second connection region SB for each light control region SL is connected to the end of each light control region SL. That is, the light controlling sheet 11 has a number of second connection regions SB corresponding to the number of light control regions SL. The multiple second connection regions SB are lined up along the second side L2 of the light controlling sheet 11. The first connection region SA is connected to at least one light control region SL and is located along the first side L1.

[0035] Note that as long as the multiple light control regions SL are arranged so that the multiple second connection regions SB are aligned along the second side L2, in other words, so that the ends of the multiple light control regions SL are aligned along a single line, there are no limitations on the shape of each light control region SL or the overall shape of the light control sheet 11. The multiple light control regions SL may include light control regions SL of different shapes.

[0036] Furthermore, the first side L1 and the second side L2 do not have to intersect directly. As shown in Figure 4, the corner Cn corresponding to the intersection of the first side L1 and the second side L2 may have a shape in which the vicinity of the intersection is partially missing depending on the arrangement of the connection areas SA and SB. The corner Cn of the light controlling sheet 11 is a region near the corner of one of the light controlling areas SL, and is a corner formed around the intersection of the first side L1 or its extension and the second side L2 or its extension.

[0037] In the above configuration, between adjacent dimming regions SL, the first transparent electrode layer 21 is conductive, while the second transparent electrode layer 22 is insulated. The insulating portion of the second transparent electrode layer 22 may be formed, for example, by laser irradiation. The dimming layer 20 and the transparent support layers 23 and 24 are each continuous between adjacent dimming regions SL.

[0038] The second transparent electrode layer 22 is conductive between adjacent dimming regions SL and second connection regions SB. That is, the second transparent electrode layer 22 is integrated between adjacent dimming regions SL and second connection regions SB, and the second electrode layer connectors 46 connected to each second connection region SB are considered to be connected to the second transparent electrode layer 22 for each dimming region SL. The second transparent electrode layer 22 is insulated between adjacent second connection regions SB. The second transparent support layer 24 is continuous between adjacent dimming regions SL and second connection regions SB, and between adjacent second connection regions SB. Furthermore, the first transparent electrode layer 21 is conductive and the first transparent support layer 23 is continuous between adjacent dimming regions SL and first connection regions SA.

[0039] The operation of the light-adjusting sheet 11 will now be described. The transparent electrode layers 21 and 22 are electrically connected to a power supply via wiring connections 12 and 13. The power supply applies a driving voltage, which is an AC voltage, to the transparent electrode layers 21 and 22 to change the alignment state of the liquid crystal compound.

[0040] In the light controlling sheet 11 configured as described above, a common voltage signal is input to the first transparent electrode layer 21 of all light controlling regions SL through the first connection portion 30. Meanwhile, a voltage signal for each light controlling region SL is input to the second transparent electrode layer 22 through the second connection portion 40 connected to the second connection region SB for each light controlling region SL. This makes it possible to apply a drive voltage independently to each light controlling region SL.

[0041] The dimming region SL switches between a transparent state and an opaque state based on a change in the alignment state of the liquid crystal compound. The transparent state is a state in which the light transmittance, i.e., the parallel ray transmittance, is relatively high, and the opaque state is a state in which the light transmittance is relatively low. The transparent state is a state in which the haze is relatively low, and the opaque state is a state in which the haze is relatively high.

[0042] When no driving voltage is applied, the orientation of the long axis of the liquid crystal compound is irregular. Therefore, due to the birefringence of the liquid crystal compound and the difference in refractive index between the liquid crystal compound and the transparent polymer layer, light incident on the dimming region SL is scattered in various directions by the dimming layer 20. Therefore, when no driving voltage is applied, the dimming region SL is in an opaque state.

[0043] When the dielectric anisotropy of the liquid crystal compound is positive, the liquid crystal compound is oriented such that its long axis is aligned with the electric field direction when a driving voltage is applied. That is, the orientation of the liquid crystal compound changes so that its long axis is aligned with the thickness direction of the switchable layer 20. As a result, light scattering in the switchable layer 20 is suppressed, and light is more easily transmitted through the switchable region SL. Therefore, the switchable region SL is in a transparent state when a driving voltage is applied.

[0044] Furthermore, the layer structure of the dimming sheet 11 may be different from the above-described structure as long as it is configured so that the transparent state and opaque state of the dimming region SL can be switched based on the change in the orientation state of the liquid crystal compound due to the application of a driving voltage.

[0045] For example, the light-modulating sheet 11 may include a pair of alignment layers sandwiching the light-modulating layer 20 between the light-modulating layer 20 and the transparent electrode layers 21 and 22. The alignment layers are layers that control the alignment of the liquid crystal compound contained in the light-modulating layer 20. The liquid crystal composition contained in the light-modulating layer 20 may also include a liquid crystal compound with negative dielectric anisotropy. For example, if the alignment layer is a vertical alignment film and the liquid crystal compound has negative dielectric anisotropy, the light-modulating region SL will be transparent when no drive voltage is applied to the transparent electrode layers 21 and 22, and will be opaque when a drive voltage is applied to the transparent electrode layers 21 and 22.

[0046] [Configuration of Wiring Connection Portion] The detailed configuration of the wiring connection portions 12, 13 will be described with reference to Fig. 1 and Figs. 5 to 9. As shown in Fig. 1, the first wiring connection portion 12 is located along the first side L1 of the light controlling sheet 11, and the second wiring connection portion 13 is located along the second side L2. The first wiring connection portion 12 includes the above-mentioned first connection portion 30, an extension portion 33 extending from the first connection portion 30 along the outer edge of the light controlling sheet 11, and a terminal portion 34 extending from the first connection portion 30 toward the outside of the transparent plate 60. The terminal portion 34 extends, for example, in a direction perpendicular to the first connection portion 30 and the extension portion 33. The first substrate portion 32, the extension portion 33, and the terminal portion 34 of the first connection portion 30 constitute a single first wiring substrate 31.

[0047] The second wiring connection portion 13 includes a plurality of second connection portions 40. The plurality of second connection portions 40 are arranged in a row along the second side L2 in accordance with the arrangement of the ends of the plurality of dimming regions SL. Adjacent second connection portions 40 are connected by continuous second substrate portions 42, and these plurality of second substrate portions 42 constitute a single second wiring substrate 41.

[0048] 1 illustrates a configuration in which the second wiring connection portion 13 has five second connection portions 40, namely, second connection portions 40a, 40b, 40c, 40d, and 40e. The second connection portions 40a, 40b, 40c, 40d, and 40e are arranged in this order, with the second connection portion 40e being located closest to the first wiring connection portion 12.

[0049] The first wiring board 31 and the second wiring board 41 are connected outside the corner Cn of the light controlling sheet 11. In detail, the end of the extension portion 33 of the first wiring connection portion 12 is connected to the second connection portion 40 at the end of the multiple second connection portions 40 arranged in a row, i.e., the second substrate portion 42 of the second connection portion 40e that is closest to the first wiring connection portion 12. As a result, the structure made up of the first wiring connection portion 12 and the second wiring connection portion 13 has a shape that bends along the edge of the light controlling sheet 11 as a whole.

[0050] If the corner Cn has a shape that includes a notch near the intersection of the first side L1 and the second side L2, a larger area can be secured outside the corner Cn compared to other areas. Therefore, even if it is necessary to widen the connection portion between the first wiring board 31 and the second wiring board 41, arranging the connection portion outside the corner Cn can prevent the connection portion from overlapping with the light controlling sheet 11, thereby preventing the light controlling unit 10 from becoming thicker.

[0051] The configuration of the conductor portion of the wiring board 31, 41 will be described with reference to FIGS. 5 to 9. FIG. 5 shows the planar structure of the second connection portion 40 located at the end farthest from the first connection portion 30, i.e., second connection portion 40a, among the multiple second connection portions 40. Note that in FIGS. 5 to 9, the positions of the conductor portion and the conductive adhesive layer are indicated by solid lines for ease of understanding. However, in the thickness direction, as shown in FIGS. 2 and 3, each portion is arranged so that the conductive adhesive layer is bonded to the transparent electrode layer and the conductor portion is electrically connected to the transparent electrode layer via the conductive adhesive layer. For example, the conductor portion may be located on the surface of the wiring board 31, 41 facing the transparent electrode layers 21, 22.

[0052] 5, the second connection portion 40a is composed of a second substrate portion 42a and a second conductive adhesive layer 49a, and is connected to a second connection region SBa. A second electrode layer connection portion 46a and a second lead-out wire 47a, which are part of the second conductor portion 45 of the second wiring board 41, are located on the second substrate portion 42a.

[0053] The end of the second electrode layer connection portion 46a overlaps the second connection region SBa and the second conductive adhesive layer 49a, and is connected to the second transparent electrode layer 22 in the second connection region SBa via the second conductive adhesive layer 49a. When the end of the second electrode layer connection portion 46a has a comb-like shape, the second substrate portion 42a is more firmly fixed to the second transparent electrode layer 22 via the second conductive adhesive layer 49a than when the end of the second electrode layer connection portion 46a has a flat film shape.

[0054] The second wiring line 47a has a linear shape extending from the second electrode layer connecting portion 46a in the extension direction of the second wiring substrate 41. The second wiring line 47a extends from an end of the second electrode layer connecting portion 46a opposite to the end joined to the second conductive adhesive layer 49a toward the second connecting portion 40b adjacent to the second connecting portion 40a.

[0055] 6 shows the planar structure of the second connection portion 40b. The second connection portion 40b is composed of a second substrate portion 42b and a second conductive adhesive layer 49b, and is connected to the second connection region SBb. The second substrate portion 42b is provided with a second electrode layer connection portion 46b and a second wiring line 47b, which are part of the second conductor portion 45, and the second wiring line 47a.

[0056] An end of the second electrode layer connection portion 46b is connected to the second transparent electrode layer 22 in the second connection region SBb via a second conductive adhesive layer 49b. The second wiring line 47b has a linear shape extending from the second electrode layer connection portion 46b. The second wiring line 47a extends continuously from the second connection portion 40a along the extension direction of the second wiring substrate 41, passing outside the second electrode layer connection portion 46b and extending toward the second connection portion 40c. The second wiring line 47b extends in the same direction as the second wiring line 47a on the side closer to the light controlling sheet 11 than the second wiring line 47a.

[0057] 7 shows the planar structure of the second connection portion 40e closest to the first connection portion 30. The second connection portion 40e is composed of a second substrate portion 42e and a second conductive adhesive layer 49e, and is connected to the second connection region SBe. The second substrate portion 42e is provided with a second electrode layer connection portion 46e and a second lead-out line 47e, which are part of the second conductor portion 45, as well as second lead-out lines 47a, 47b, 47c, and 47d. An end of the second electrode layer connection portion 46e is connected to the second transparent electrode layer 22 in the second connection region SBe via the second conductive adhesive layer 49e. The second lead-out line 47e has a linear shape extending from the second electrode layer connection portion 46e.

[0058] The second wiring lines 47a, 47b, 47c, and 47d extend outside the second electrode layer connection portion 46e in the direction in which the second wiring substrate 41 extends. As described above, the second wiring line 47a extends from the second connection portion 40a through the second connection portions 40b, 40c, and 40d to the second connection portion 40e, and the second wiring line 47b extends from the second connection portion 40b through the second connection portions 40c and 40d to the second connection portion 40e. Similarly, the second wiring line 47c extends from the second connection portion 40c through the second connection portion 40d to the second connection portion 40e, and the second wiring line 47d extends from the second connection portion 40d to the second connection portion 40e. The second lead-out wires 47a, 47b, 47c, 47d, and 47e are arranged in this order in the width direction of the second wiring board 41 so as to approach the light controlling sheet 11, and extend in parallel in a common direction.

[0059] In this way, the second wiring wires 47 extend from the electrode layer connection portion 46 of each second connection portion 40 toward the end portion of the second wiring board 41 that is connected to the first wiring board 31. The paths of the second wiring wires 47 are not limited as long as the second wiring wires 47 do not intersect with each other. For example, as shown in the drawings, the second wiring wires 47 may be arranged along the width direction of the second wiring board 41 so that the closer the second connection portion 40 is to the first connection portion 30, the closer the second connection portion 40 is to the first connection portion 30, the closer the second wiring wires 47 extending from the second electrode layer connection portion 46 of the second connection portion 40 passes to a position closer to the light controlling sheet 11.

[0060] 8 shows an enlarged planar structure near the connection portion between the first wiring board 31 and the second wiring board 41. As shown in Fig. 8, the first wiring board 31 and the second wiring board 41 are connected via a third conductive adhesive layer 50. This establishes electrical continuity between the first conductor portion 35 of the first wiring board 31 and the second conductor portion 45 of the second wiring board 41. The third conductive adhesive layer 50 is made of an anisotropic conductive material, such as an anisotropic conductive film.

[0061] More specifically, second wiring lines 47 are located at the end of the second wiring board 41, and these ends are connected to the end of the extension portion 33 of the first wiring board 31. Extension lines 38, which are part of the first conductor portion 35, are located in the extension portion 33. The same number of extension lines 38 as the second wiring lines 47 are located in the extension portion 33, and the end of the second wiring board 41 is connected to the extension portion 33 so that one extension line 38 is connected to each second wiring line 47. Each extension line 38 extends toward the terminal portion 34 of the first wiring board 31.

[0062] In the example shown in Figure 8, extension line 38a is connected to second wiring line 47a, extension line 38b is connected to second wiring line 47b, extension line 38c is connected to second wiring line 47c, extension line 38d is connected to second wiring line 47d, and extension line 38e is connected to second wiring line 47e.

[0063] 9 shows a planar structure near the first connection portion 30 and the terminal portion 34. A first electrode layer connection portion 36 and a first wiring line 37, which are part of the first conductor portion 35, and the above-mentioned extension line 38 are located in the first substrate portion 32 of the first connection portion 30. An end of the first electrode layer connection portion 36 is connected to the first transparent electrode layer 21 in the first connection area SA via a first conductive adhesive layer 39. The first wiring line 37 has a linear shape extending from the first electrode layer connection portion 36.

[0064] The first lead-out wire 37 extends toward the terminal portion 34. Furthermore, the multiple extension wires 38 extending from the extension portion 33 also bend at appropriate positions and extend toward the terminal portion 34. The first lead-out wire 37 and each extension wire 38 are located in the terminal portion 34. That is, the first lead-out wire 37 electrically connected to the first transparent electrode layer 21 and the multiple extension wires 38 electrically connected one by one to the second transparent electrode layer 22 in each dimming region SL are drawn out to the terminal portion 34.

[0065] Wiring is connected to the first outgoing wire 37 and each extension wire 38 of the terminal portion 34, and this wiring is connected to a power supply, thereby connecting the light controlling sheet 11 to the power supply. This allows a drive voltage to be input from the power supply to the terminal portion 34, making it possible to apply the drive voltage independently to each light controlling region SL.

[0066] As described above, in this embodiment, the first wiring board 31 and the second wiring board 41 are connected, and the second wiring lines 47 and the extension lines 38, which are conductor lines extending from each second connection portion 40, are routed to the terminal portion 34 of the first wiring board 31. Therefore, it is possible to input a voltage signal to the first transparent electrode layer 21 and to the second transparent electrode layer 22 of each dimming region SL from one terminal portion 34. In the above configuration, the routing of the wiring from each second connection portion 40 is handled by the conductor portions 35, 45 of the wiring boards 31, 41. Therefore, compared to when lead wires are used for the routing wiring, it is possible to reduce the required area and also to make the portion that functions as the routing wiring thinner.

[0067] For example, the thickness of the resin base material of the wiring boards 31, 41 is 12.5 μm to 50 μm, the thickness of the conductor portions 35, 45 is 9 μm to 70 μm, and the thickness of the adhesive between the conductor portions 35, 45 and the resin base material is 0 μm to 35 μm. Furthermore, the thickness of the conductive adhesive layers 39, 49, 50 is 10 μm to 20 μm, and the thickness of the laminate of the transparent electrode layers 21, 22 and the transparent support layers 23, 24 is 12.5 μm to 50 μm. Therefore, the wiring connection portions 12, 13 can be thinner than the light-controlling sheet 11, and it is also possible to prevent the connection portion between the first wiring connection portion 12 and the second wiring connection portion 13 from being thicker than the light-controlling sheet 11.

[0068] Therefore, it is easy to arrange the entire second wiring connection portion 13, including the portion that functions as the lead wiring, on the transparent plate 60. When the dimming unit 10 is sandwiched between two transparent plates 60, the portion that functions as the lead wiring can also be arranged in the area sandwiched between the transparent plates 60. Specifically, the entire second wiring connection portion 13, including the connection portion with the first wiring connection portion 12, is contained in the area sandwiched between the transparent plates 60, and only the terminal portion 34 of the first wiring connection portion 12 protrudes outside the transparent plate 60. Therefore, it is possible to significantly reduce the area required outside the transparent plate 60.

[0069] Since the area required outside the transparent plate 60 is reduced, the dimming unit 10 can be easily disposed even when it is difficult to secure a large area outside the transparent plate 60, such as when the dimming unit 10 is attached to a window of a vehicle.

[0070] If a flexible printed circuit board is used as the wiring board 31, 41, the patterns of the conductor portions 35, 45 can be formed by etching, allowing the routing lines 37, 47 and the extension lines 38 to be formed in a fine linear shape. Therefore, even if the number of dimming regions SL is large, the width of the wiring board 31, 41 can be prevented from increasing. Therefore, even if a frame-shaped member is provided to conceal the portions where the wiring connection portions 12, 13 are located, the width of this member can be kept narrow. Furthermore, by separately forming the first wiring board 31 and the second wiring board 41, the number of wiring boards 31, 41 that can be formed from one substrate can be increased, enabling efficient production.

[0071] As described above, according to this embodiment, the following effects can be obtained: (1) The first wiring board 31 and the second wiring board 41 are connected, and the conductor wires extending from the connection portions 30 and 40 are routed to the terminal portion 34. Therefore, compared to when lead wires are used for the routed wiring, the portion where the routed wiring is located can be made thinner and smaller, and the area required for routing the wiring can be reduced.

[0072] (2) Because the first wiring connection portion 12 having one first connection portion 30 has the terminal portion 34, the size of the second wiring board 41 is suppressed compared to when the second wiring connection portion 13 having multiple second connection portions 40 also has the terminal portion 34. Therefore, the expansion of the wiring boards 31, 41 is suppressed, enabling efficient production.

[0073] (3) The first side L1 on which the first wiring connection portion 12 is located and the second side L2 on which the second wiring connection portion 13 is located extend in directions that intersect with each other. This makes it easy to connect the ends of the first wiring board 31 and the second wiring board 41 close to each other, and it is possible to suppress an increase in the wiring routing distance and the size of the wiring boards 31 and 41.

[0074] (4) If the first wiring board 31 and the second wiring board 41 are connected outside the corner Cn of the light-adjusting sheet 11, the wiring boards 31, 41 are prevented from having a complex shape, and it is easier to secure a wide area for connection.

[0075] (5) The wiring boards 31 and 41 are flexible printed circuit boards, and the first wiring board 31 and the second wiring board 41 are connected via the third conductive adhesive layer 50 made of an anisotropic conductive material. This configuration makes it possible to preferably realize thin wiring boards 31 and 41, and also makes it possible to preferably connect the wiring boards 31 and 41.

[0076] (6) The dimming unit 10 is sandwiched between two transparent plates 60, the terminal portion 34 of the first wiring connection portion 12 protrudes outside the two transparent plates 60, and the entire second wiring connection portion 13 is sandwiched between the two transparent plates 60. This configuration makes it possible to significantly reduce the area required outside the transparent plates 60 for connection to the power supply device.

[0077] (Modifications) The above embodiment may be modified as follows: The following modifications may be combined with each other.

[0078] In the above embodiment, the first wiring connection portion 12 includes the terminal portion 34, and the conductor wires routed from the respective connection portions 30, 40 are gathered at the first wiring connection portion 12. However, the present invention is not limited to this, and the second wiring connection portion 13 may include a terminal portion, and the conductor wires routed from the respective connection portions 30, 40 may be gathered at the second wiring connection portion 13. In this case, each second routing wire 47 extends to the terminal portion of the second wiring connection portion 13, and the extension wire of the terminal portion is connected to the first routing wire 37 by the connection between the first wiring board 31 and the second wiring board 41.

[0079] In a configuration in which the dimming unit 10 is attached to one transparent plate 60, the first transparent support layer 23 may be attached to the transparent plate 60. In other words, either the transparent electrode layer closer to the transparent plate 60 or the transparent electrode layer farther from the transparent plate 60 may be divided into individual dimming regions SL.

[0080] The first wiring board 31 and the second wiring board 41 may be connected at a position other than the outside of the corner Cn of the light controlling sheet 11. The first side L1 on which the first wiring connection portion 12 is located and the second side L2 on which the second wiring connection portion 13 is located do not have to extend in intersecting directions. For example, the first side L1 and the second side L2 may be sides that extend parallel to each other, and at least one of the first wiring connection portion 12 and the second wiring connection portion 13 may have a bent shape, thereby connecting these wiring connection portions 12 and 13.

[0081] The first wiring substrate 31 may be made up of a plurality of wiring substrates, and the second wiring substrate 41 may be made up of a plurality of wiring substrates. The first transparent electrode layer 21 may also be insulated between adjacent dimming regions SL. In this case, the first wiring connection portion 12 has a plurality of first connection portions 30 connected to the first connection areas SA of each dimming region SL, and a first wiring wire 37 extends from the first electrode layer connection portion 36 of each first connection portion 30. The plurality of first wiring wires 37 and the plurality of second wiring wires 47 are then collected in the terminal portion 34 based on the connection of the extension wires 38.

[0082] The expression "at least one" used in this specification means "one or more" of the desired options. As an example, the expression "at least one" used in this specification means "only one option" or "both of two options" if the number of options is two. As another example, the expression "at least one" used in this specification means "only one option" or "any combination of two or more options" if the number of options is three or more.

Claims

1. A light-adjusting unit comprising: a light-adjusting sheet comprising a light-adjusting layer containing a liquid crystal composition and a pair of transparent electrode layers sandwiching the light-adjusting layer, the first transparent electrode layer and the second transparent electrode layer; a first wiring connection portion comprising a first wiring substrate; and a second wiring connection portion comprising a second wiring substrate, wherein, when viewed from a position facing the surface of the light-adjusting sheet, the light-adjusting sheet has a plurality of light-adjusting regions, and the second transparent electrode layer is insulated between adjacent light-adjusting regions; a first conductor portion of the first wiring substrate includes a first electrode layer connection portion connected to the first transparent electrode layer and a first wiring wire extending from the first electrode layer connection portion; and a second conductor portion of the second wiring substrate includes a plurality of second electrode layer connection portions connected one by one to the second transparent electrode layer in each light-adjusting region, and a plurality of second wiring wires extending one by one from each second electrode layer connection portion. a target wiring board, which is one of the first wiring board and the second wiring board, has a terminal portion at an end to which a drive voltage is input, and the pull-out wire of the target wiring board and an extension wire included in the conductor portion of the target wiring board extend to the terminal portion, and by connecting the first wiring board and the second wiring board, the pull-out wire of the other of the first wiring board and the second wiring board is connected to the extension wire.

2. The dimming unit according to claim 1, wherein the first transparent electrode layer is conductive between adjacent dimming regions, the target wiring board is the first wiring board, the first conductor portion includes a plurality of extension lines extending to the terminal portion, and the first wiring board and the second wiring board are connected so that one extension line is connected to each second routing line.

3. The dimming unit of claim 1, wherein, when viewed from a position opposite the surface of the dimming sheet, the dimming sheet has a first side and a second side extending in a direction intersecting the first side, the ends of the multiple dimming areas are aligned along the direction in which the second side extends, the first wiring connection portion is located along the first side, and the second wiring connection portion is located along the second side.

4. The dimming unit described in claim 3, wherein the first wiring board and the second wiring board are connected outside a corner of the dimming sheet corresponding to the intersection of the first side and the second side.

5. The dimming unit according to claim 1, wherein each of the first wiring board and the second wiring board is a flexible printed circuit board, and the first wiring board and the second wiring board are connected via an anisotropic conductive material.

6. A dimming board comprising: a dimming unit according to any one of claims 1 to 5; and two transparent plates sandwiching the dimming unit, wherein the terminal portion protrudes outside the two transparent plates, and the other wiring board is entirely sandwiched between the two transparent plates.

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