Flexible wiring board, dimming device, and dimming system

Abstract

The present invention provides a dimming device, a dimming system, and a flexible wiring board that reduce the wiring installation load so as to adapt the wiring layout to the specifications of the dimming device. [Solution] The device comprises a pair of transparent electrode layers consisting of a first transparent electrode layer 34 and a second transparent electrode layer 32, a dimming layer disposed between the first transparent electrode layer and the second transparent electrode layer, and a first flexible wiring board 40 connected to the first transparent electrode layer 34. The first transparent electrode layer 34 comprises a plurality of first divided electrodes 34B electrically separated by a first insulating portion 34A. The first flexible wiring board 40 comprises a first electrode connection portion 42 connected to the first divided electrodes 34B, and a plurality of first terminals 43 connected in parallel to the first electrode connection portion 42 for connecting the first electrode connection portion 42 to a drive unit 60.

Description

Technical Field

[0001] The present disclosure relates to a flexible wiring board joined to a transparent electrode layer of a dimming device, a dimming device including the flexible wiring board, and a dimming system.

Background Art

[0002] A dimming device applied to a window of a building or a vehicle includes a liquid crystal composition between a first transparent electrode layer and a second transparent electrode layer. The orientation of the liquid crystal composition changes according to a driving voltage applied to the transparent electrode layer. A dimming device enabling divided driving divides the first transparent electrode layer into a plurality of transparent electrode portions. Divided driving for driving the liquid crystal composition for each transparent electrode portion gives high designability to the dimming range (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The improvement in designability by divided driving is on the way to expanding the application targets of the dimming device. On the other hand, the arrangement of wirings connecting the driving unit to the dimming device varies depending on the application target on which each device is mounted. For this reason, it is desired to reduce the mounting load of the wiring so as to conform the wiring arrangement to the specifications of the dimming device.

Means for Solving the Problems

[0005] A dimming device for solving the above problems comprises a pair of transparent electrode layers consisting of a first transparent electrode layer and a second transparent electrode layer, a dimming layer disposed between the first transparent electrode layer and the second transparent electrode layer, and a flexible wiring board connected to the first transparent electrode layer. Each transparent electrode layer is provided with a plurality of divided electrodes electrically separated by an insulating portion, and the flexible wiring board is provided with an electrode connection portion connected to the divided electrodes of the first transparent electrode layer, and a plurality of terminals connected in parallel to the electrode connection portion for connecting the electrode connection portion to a drive portion that drives the dimming layer.

[0006] The wiring connected to the drive unit of the dimming layer supplies power to the transparent electrode layer through terminals on a flexible wiring board. With the above configuration, the arrangement of the wiring supplying power to the electrode connection part is made more flexible by the number of terminals connected in parallel to the electrode connection part. Therefore, the wiring installation burden required to adapt the wiring arrangement to the specifications of the dimming device is reduced.

[0007] In the dimming device described above, the plurality of divided electrodes are arranged along a first direction, and the electrode connection portion is a first electrode connection portion that extends in the first direction and further comprises a plurality of second electrode connection portions, one for each of the divided electrodes constituting the second transparent electrode layer, which are connected in parallel to each of the divided electrodes constituting the second transparent electrode layer.

[0008] According to the above configuration, multiple divided electrodes are connected in parallel to the first electrode connection point. Then, one second electrode connection point is connected to each divided electrode. Therefore, in a dimming device that applies a common voltage to multiple divided electrodes, the wiring load required to adapt the wiring arrangement to the specifications of the dimming device is reduced.

[0009] In the above-described dimming device, the first transparent electrode layer may comprise a first insulating portion and a plurality of first divided electrodes insulated from each other by the first insulating portion, and the second transparent electrode layer may comprise a second insulating portion that overlaps the first insulating portion in the thickness direction of the dimming layer and a plurality of second divided electrodes insulated from each other by the second insulating portion.

[0010] Because the first transparent electrode layer, the dimming layer, and the second transparent electrode layer are thin, processing only the first transparent electrode layer into multiple segmented electrodes may be subject to various constraints, such as avoiding cutting the second transparent electrode layer. In this respect, processing by overlapping the second insulating layer with the first insulating layer in the thickness direction of the dimming layer can alleviate these constraints. Therefore, in a dimming device where the processing load of segmented electrodes is reduced, the wiring installation load required to adapt the wiring layout to the specifications of the dimming device is also reduced.

[0011] In the dimming device described above, the plurality of divided electrodes may be arranged along a first direction, the electrode connection portion may extend in the first direction and the plurality of divided electrodes constituting the first transparent electrode layer may be connected in parallel, and the plurality of terminals may be arranged along the first direction.

[0012] With the above configuration, since multiple terminals are arranged along the first direction, a group of terminals for applying a common voltage to multiple divided electrodes is easily visible. Therefore, it is easy to understand during wiring installation that connecting a wire to any of the terminals arranged in the first direction will apply a common voltage to multiple divided electrodes.

[0013] In the dimming device described above, the divided electrode extends in a second direction intersecting the first direction from the second end to the first end, the first electrode connection portion is formed by the parallel connection of the first ends of a plurality of the divided electrodes in the first transparent electrode layer, and the second electrode connection portion may be connected one by one to the second ends of the divided electrodes in the second transparent electrode layer.

[0014] According to the above configuration, a common voltage is applied to each divided electrode from the first end of the divided electrode extending in the second direction. Then, a voltage is applied to each divided electrode from the second end of the divided electrode extending in the second direction. As a result, the voltage applied between the divided electrodes of the first transparent electrode layer and the divided electrodes of the second transparent electrode layer is made uniform in the second direction. Therefore, in a dimming device in which the voltage between divided electrodes is made uniform, the wiring load required to adapt the wiring arrangement to the specifications of the dimming device is reduced.

[0015] In the dimming device described above, the plurality of terminals may be arranged at regular intervals along the first direction. According to the above configuration, the candidates for wiring connections are arranged at regular intervals, further reducing the wiring installation burden required to adapt the wiring layout to the specifications of the dimmer.

[0016] In the above-described dimming device, the terminal may be a double-sided pad. According to the above configuration, the wiring arrangement offers greater flexibility on both the front and back sides of the flexible wiring board. This further reduces the burden of wiring installation, which is required to adapt the wiring arrangement to the specifications of the dimming device.

[0017] In the above-described dimming device, the end of the flexible wiring board may be provided with an exposed connecting portion connected to the electrode connection portion, and the connecting portion may be configured to be electrically connected to the connecting portion of another flexible wiring board.

[0018] With the above configuration, the two flexible wiring boards are electrically connected at their ends, allowing the length of the flexible wiring board to be increased. In the above-described dimming device, an insulating film is provided to support the electrode connection portion and the terminal, and the insulating film may have a weak portion between the electrode connection portion and the terminal for separating the terminal from the electrode connection portion.

[0019] According to the above configuration, terminals that are not connected to the wiring are disconnected by the vulnerable part. As a result, the mounting load of wiring that would otherwise be required to adapt the wiring arrangement to the specifications of the dimming device is reduced, while the size of the flexible wiring board is also reduced.

[0020] A dimming system for solving the above problems comprises a pair of transparent electrode layers consisting of a first transparent electrode layer and a second transparent electrode layer, a dimming layer disposed between the first transparent electrode layer and the second transparent electrode layer, a flexible wiring board electrically connected to the first transparent electrode layer, a drive unit for driving the dimming layer, and wiring electrically connecting the flexible wiring board to the drive unit. Each transparent electrode layer comprises a plurality of divided electrodes electrically separated by an insulating portion, the flexible wiring board comprises an electrode connection portion electrically connected to the first transparent electrode layer, a plurality of parallel wirings connected in parallel to the electrode connection portion and extending from the electrode connection portion, and an insulating film supporting the electrode connection portion and the parallel wiring, a portion of the plurality of parallel wirings being connected to a terminal for connecting the electrode connection portion to the drive unit, and the other portion of the plurality of parallel wirings being cut together with the insulating film to be shorter than the portion of the plurality of parallel wirings, forming a cut mark.

[0021] According to the above configuration, the wiring connected to the drive unit supplies power to the transparent electrode layer through the terminals of the flexible wiring board, the parallel wiring connected to those terminals, and the electrode connection section where multiple parallel wirings are connected in parallel. The arrangement of the wiring is made more flexible by the number of parallel wirings. As a result, the mounting burden of wiring to adapt the wiring arrangement to the specifications of the dimming device is reduced. Furthermore, the parallel wiring not connected to the drive unit is cut to be shorter than the parallel wiring connected to the drive unit. As a result, the parallel wiring used to reduce the mounting burden does not lead to an increase in the size of the flexible wiring board within the dimming system.

[0022] The flexible printed circuit board for solving the above problems is a flexible printed circuit board connected to the dimming sheet. The dimming sheet includes a pair of transparent electrode layers composed of a first transparent electrode layer and a second transparent electrode layer, and a dimming layer disposed between the first transparent electrode layer and the second transparent electrode layer. Each transparent electrode layer includes a plurality of divided electrodes electrically divided by insulating portions. The flexible printed circuit board extends in a direction in which the divided electrodes of the first transparent electrode layer are arranged, and has a plurality of divided electrodes connected in parallel having comb teeth arranged in the direction, and one electrode connection portion; and a plurality of terminals connected in parallel to the electrode connection portion and arranged at a certain interval along the direction.

[0023] The wiring connected to the driving portion of the dimming layer supplies power to the transparent electrode layer through at least one terminal among the plurality of terminals included in the flexible printed circuit board and an electrode connection portion common to the plurality of terminals. According to the above configuration, the arrangement of the wiring increases the degree of freedom by the number of terminals. Therefore, the mounting load of the wiring for adapting the wiring arrangement to the specifications of the dimming device is reduced.

Effect of the Invention

[0024] According to the above dimming system, dimming device, and flexible printed circuit board, the mounting load of the wiring for adapting the wiring arrangement to the specifications of the dimming device can be reduced.

Brief Description of the Drawings

[0025] [Figure 1] FIG. 1 is a configuration diagram showing a dimming system. [Figure 2] FIG. 2 is a cross-sectional view showing a part of the dimming sheet. [Figure 3] FIG. 3 is a plan view showing the surface structure of the flexible printed circuit board. [Figure 4] FIG. 4 is a plan view showing the back surface structure of the flexible printed circuit board. [Figure 5] FIG. 5 is a cross-sectional view showing the connection structure of the flexible printed circuit board. [Figure 6] FIG. 6 is a cross-sectional view showing the connection structure of the flexible printed circuit board. [Figure 7] Figure 7 is a diagram showing the configuration of the dimming system. [Modes for carrying out the invention]

[0026] [Dimming System 10] As shown in Figure 1, the dimming system 10 comprises a dimming device 20, a drive unit 60, a first wiring 61, and a second wiring 62. The dimming device 20 is connected to the drive unit 60 via the first wiring 61. The dimming device 20 is also connected to the drive unit 60 via the second wiring 62. The drive unit 60 applies a common voltage to the dimming device 20 through the first wiring 61. The drive unit 60 applies a control voltage to the dimming device 20 through the second wiring 62.

[0027] There may be two or more first wires 61 connecting the drive unit 60 to the dimming device 20. If there are two or more first wires 61, the drive unit 60 applies a common voltage to all of the first wires 61. There are two or more second wires 62 connecting the drive unit 60 to the dimming device 20. The drive unit 60 has a mode in which it applies a different control voltage to each of the second wires 62, and a mode in which it applies the same control voltage to all of the second wires 62.

[0028] [Dimming device 20] The dimming device 20 comprises a dimming sheet 30, a first flexible wiring board 40, and a second flexible wiring board 50. The first wiring 61 electrically connects the first flexible wiring board 40 to the drive unit 60. The second wiring 62 electrically connects the second flexible wiring board 50 to the drive unit 60. The dimming sheet 30 may be attached to a transparent substrate such as a transparent glass substrate or a transparent resin substrate, or it may be sandwiched between transparent substrates.

[0029] As shown in Figure 2, the dimming sheet 30 comprises a second transparent support layer 31, a second transparent electrode layer 32, a first transparent support layer 35, a first transparent electrode layer 34, and a dimming layer 33. The first transparent support layer 35 and the second transparent support layer 31 are transparent substrates that transmit light in the visible region. The first transparent support layer 35 supports the first transparent electrode layer 34 on its upper surface (Figure 2). The second transparent support layer 31 supports the second transparent electrode layer 32 on its lower surface (Figure 2). The side of the first transparent support layer 35 opposite to the first transparent electrode layer 34 is the back surface of the dimming sheet 30. The side of the second transparent support layer 31 opposite to the second transparent electrode layer 32 is the back surface of the dimming sheet 30.

[0030] The constituent materials of the first transparent support layer 35 and the second transparent support layer 31 may be synthetic resins or inorganic compounds, respectively. The constituent materials of the first transparent support layer 35 and the second transparent support layer 31 may be equal to or different from each other. The synthetic resin may be at least one selected from the group consisting of polyester, polycarbonate, polypropylene, polystyrene, acrylic resin, nylon resin, polyurethane, polyethylene, polyvinyl alcohol, polyvinyl chloride, polyimide, polysulfone, cycloolefin polymer, and triacetylcellulose. The inorganic compound may be at least one selected from the group consisting of silicon dioxide, silicon oxynitride, and silicon nitride.

[0031] The first transparent electrode layer 34 and the second transparent electrode layer 32 each have transparent conductivity that transmits light in the visible region. The first transparent electrode layer 34 may be laminated on the upper surface of the first transparent support layer 35. The second transparent electrode layer 32 may be laminated on the lower surface of the second transparent support layer 31. The first transparent electrode layer 34 comprises one or more first insulating portions 34A and a plurality of first divided electrodes 34B. The second transparent electrode layer 32 comprises one or more second insulating portions 32A and a plurality of second divided electrodes 32B.

[0032] Returning to Figure 1, the first insulating portion 34A has a linear shape extending in the second direction D2. The first insulating portion 34A may have a straight line extending in the second direction D2, or it may have a curved shape such as a bent line or an arc. When the first transparent electrode layer 34 comprises a plurality of first insulating portions 34A, the plurality of first insulating portions 34A are arranged at intervals in the first direction D1 which is perpendicular to the second direction D2. The first transparent electrode layer 34 shown in Figure 1 comprises four first insulating portions 34A, each having a straight line extending in the second direction D2 and at a constant interval in the first direction D1.

[0033] The first insulating portion 34A insulates the first divided electrodes 34B adjacent to each other in the first direction D1. The first insulating portion 34A is integral with the first divided electrodes 34B that are insulated by the first insulating portion 34A. The first transparent support layer 35 is continuous between the adjacent first divided electrodes 34B.

[0034] The second insulating portion 32A has a linear shape extending in the second direction D2. The second insulating portion 32A has the same shape as the first insulating portion 34A. When the second transparent electrode layer 32 comprises a plurality of second insulating portions 32A, the plurality of second insulating portions 32A are arranged in the first direction D1 at intervals equal to the intervals of the first insulating portions 34A. The second transparent electrode layer 32 shown in Figure 1 comprises four second insulating portions 32A, each having a linear shape extending in the second direction D2 and spaced at a constant interval in the first direction D1.

[0035] The second insulating portion 32A insulates the adjacent second divided electrodes 32B in the first direction D1 from each other. The second insulating portion 32A is integral with the second divided electrodes 32B insulated by the second insulating portion 32A. The second transparent support layer 31 is continuous between adjacent second divided electrodes 32B. The second insulating portion 32A overlaps with the first insulating portion 34A in the thickness direction of the dimming layer 33 (see Figure 2). The first insulating portion 34A and the second insulating portion 32A may be formed by the same laser irradiation to the first transparent electrode layer 34 and the second transparent electrode layer 32.

[0036] Multiple first divided electrodes 34B are arranged along a first direction D1. Adjacent first divided electrodes 34B in the first direction D1 are insulated by a single first insulating portion 34A. Multiple second divided electrodes 32B are arranged along the first direction D1. Adjacent second divided electrodes 32B in the first direction D1 are insulated by a single second insulating portion 32A. The first divided electrodes 34B and the second divided electrodes 32B each extend along a second direction D2 from a second end to a first end. A single first flexible wiring board 40 is connected to the first end 34BE of multiple first divided electrodes 34B. A second flexible wiring board 50 is connected to each second end 32BE of multiple second divided electrodes 32B.

[0037] The constituent materials of the first transparent electrode layer 34 and the second transparent electrode layer 32 may each be at least one selected from the group consisting of polymers containing indium tin oxide (ITO), fluorine-doped tin oxide (FTO), tin oxide, zinc oxide, carbon nanotubes (CNTs), poly(3,4-ethylenedioxythiophene) (PEDOT), and multilayer films containing Ag alloy thin films.

[0038] [Dimming layer 33] The light-adjusting layer 33 changes its optical state from transparent to opaque, or from opaque to transparent, depending on the power supplied between the first divided electrode 34B and the second divided electrode 32B. The light-adjusting layer 33 may be a polymer dispersed liquid crystal element, a polymer network liquid crystal element, or a guest-host liquid crystal element. The light-adjusting layer 33 may be a suspended particle device, a photochromic element, an electrochromic element, or an electrokinetic element.

[0039] An example of a light-adjusting layer 33 comprises a transparent polymer layer and a liquid crystal composition. The transparent polymer layer partitions the voids into which the liquid crystal composition is filled. The shape of the voids may be spherical, ellipsoidal, or irregular. The structure of the light-adjusting layer 33 may be a polymer network type, a polymer dispersion type, or a capsule type. A polymer network type light-adjusting layer 33 comprises a polymer network having a three-dimensional mesh structure. The polymer network is an example of a transparent polymer layer, and the liquid crystal composition is held in the interconnected mesh voids of the polymer network. A polymer dispersion type light-adjusting layer 33 comprises a transparent polymer layer partitioning a number of isolated voids, and the liquid crystal composition is held in the voids dispersed in the transparent polymer layer. A capsule type light-adjusting layer 33 holds the liquid crystal composition in the voids within capsules dispersed in the transparent polymer layer.

[0040] The transparent polymer layer is a polymer of a photopolymerizable compound. Photopolymerizable compounds are, for example, UV polymerizable compounds. UV polymerizable compounds include, for example, acrylate compounds such as butyl ethyl acrylate and cyclohexyl acrylate, methacrylate compounds such as N,N-dimethylaminoethyl methacrylate and phenoxyethyl methacrylate, stilbene compounds, diacrylate compounds, dimethacrylate compounds, triacrylate compounds, trimethacrylate compounds, tetraacrylate compounds, tetramethacrylate compounds, and oligomers of these compounds.

[0041] The liquid crystal composition contains a liquid crystal compound and a dichroic dye. The liquid crystal composition may also contain viscosity reducers, defoamers, antioxidants, weather-resistant agents, etc. Examples of liquid crystal compounds include Schiff base-based, azo-based, azoxy-based, biphenyl-based, terphenyl-based, benzoic acid ester-based, tran-based, pyrimidine-based, pyridazine-based, cyclohexanecarboxylic acid ester-based, phenylcyclohexane-based, biphenylcyclohexane-based, dicyanobenzene-based, naphthalene-based, and dioxane-based compounds.

[0042] Dichroic dyes exhibit color when driven by a guest-host mechanism using liquid crystal compounds as the host. Dichroic dyes include polyiodine, azo compounds, anthraquinone compounds, naphthoquinone compounds, azomethine compounds, tetrazine compounds, quinophthalone compounds, merocyanine compounds, perylene compounds, and dioxazine compounds.

[0043] In addition to the first transparent support layer 35, the first transparent electrode layer 34, the second transparent support layer 31, the second transparent electrode layer 32, and the photochromic layer 33, the photochromic sheet 30 may also have a functional layer. An example of a functional layer is one that protects the photochromic layer 33, the first transparent electrode layer 34, and the second transparent electrode layer 32. The functional layer with protective function may be a gas barrier layer or an ultraviolet barrier layer. The gas barrier layer may be placed between the first transparent support layer 35 and the first transparent electrode layer 34, or between the second transparent support layer 31 and the second transparent electrode layer 32. An example of a functional layer is one that contributes to the control of light transmittance. The functional layer that contributes to the control of light transmittance may be an alignment layer or a polarizing layer. The alignment layer may be placed between the first transparent electrode layer 34 and the photochromic layer 33, or between the second transparent electrode layer 32 and the photochromic layer 33. The polarizing layer may be placed between the first transparent support layer 35 and the first transparent electrode layer 34, or between the second transparent support layer 31 and the second transparent electrode layer 32. An example of a functional layer is one that enhances the strength and heat resistance of the photochromic sheet 30. The functional layer that enhances strength and heat resistance may be a hard coat layer. The hard coat layer may be placed on the lower surface of the first transparent support layer 35, or on the upper surface of the second transparent support layer 31. An example of a functional layer may be a layer that enhances the adhesion between layers within the photochromic sheet 30.

[0044] [First flexible wiring board 40] The first flexible wiring board 40 electrically connects the first transparent electrode layer 34 to the drive unit 60. The first flexible wiring board 40 is an FPC (Flexible Printed Circuits) that applies a common voltage from the drive unit 60 to the first transparent electrode layer 34.

[0045] The first flexible printed circuit board 40 may be a double-sided FPC, a double-sided exposed FPC, a single-sided FPC, or a multilayer FPC. A double-sided FPC has wiring layers on both sides of an insulating base film, and a portion of each wiring layer is separately covered with a covering insulating film. A double-sided exposed FPC has a portion of both sides of a single wiring layer separately covered with a covering insulating film. A single-sided FPC has wiring layers on one side of an insulating base film, and a portion of the wiring layer is covered with a single covering insulating film. A multilayer FPC has three or more wiring layers laminated with insulating films in between.

[0046] The following example shows a first flexible printed circuit board 40 that is a double-sided exposed FPC and has first terminals 43 on both the front and back surfaces of the first flexible printed circuit board 40. Alternatively, the first flexible printed circuit board 40 may be a single-sided FPC and have first terminals 43 on either the front or back surface of the first flexible printed circuit board 40.

[0047] As shown in Figure 3, the first flexible wiring board 40 has a strip shape extending in one direction. The first flexible wiring board 40 is bonded to the dimming sheet 30 such that the direction in which the first flexible wiring board 40 extends coincides with the first direction D1 in the dimming device 20.

[0048] The first flexible wiring board 40 is provided with a plurality of lead-outs that protrude in a direction intersecting the direction in which the first flexible wiring board 40 extends. The surface of the first flexible wiring board 40 (the surface facing the viewer in Figure 1) is provided with one front-side first terminal 43 at each lead-out. The lead-outs may be arranged at a constant interval in the extending direction of the first flexible wiring board 40, or they may be arranged at different intervals from each other. The lead-outs may be unevenly distributed at the ends and the center in the extending direction of the first flexible wiring board 40. The number of lead-outs on the first flexible wiring board 40 is greater than the number of first wirings 61.

[0049] The surface of the first flexible wiring board 40 is covered by the first insulating film 41 on the front side, except for the first terminal 43 on the front side and one connecting portion 45 (the connecting portion 45 on the upper side of the paper in Figure 1). The first terminal 43 on the front side is supported around the periphery by the first insulating film 41 on the front side. As shown in Figure 1, in the dimming system 10, the first wiring 61 is connected to only one of the multiple first terminals 43. In the dimming system 10, among the multiple first terminals 43, the first terminal 43 located at the lower end of the first direction D1 may be connected to the first wiring 61. In the dimming system 10, among the multiple first terminals 43, the first terminal 43 located at the upper end may be connected to the first wiring 61, or the first terminal 43 located in the center may be connected to the first wiring 61. The position of the first terminal 43 connected to the first wiring 61 can be appropriately selected in the first direction D1 depending on the arrangement of the drive unit 60, the arrangement of the first wiring 61, the shape of the surrounding structure on which the dimming device 20 is mounted, and so on.

[0050] If the dimming system 10 includes a plurality of first wirings 61, the plurality of first terminals 43 include at least one first terminal 43 to which the first wiring 61 is not connected. In the dimming system 10, among the plurality of first terminals 43, two first terminals 43 located at the lower end and upper end of the first direction D1 may be connected to the first wiring 61, or two first terminals 43 located at the upper end and center may be connected to the first wiring 61. The positions of two or more first terminals 43 connected to the first wiring 61 are appropriately selected in the first direction D1 depending on the arrangement of the drive unit 60, the arrangement of the first wiring 61, the shape of the surrounding structure on which the dimming device 20 is mounted, the magnitude of the potential gradient that may occur in the first direction D1, etc.

[0051] The first insulating film 41 on the front side may be a single-layer polyimide film, a multilayer polyimide film joined via an adhesive, a liquid crystal polymer film, a polyethylene terephthalate film, or an aramid cellulose ester film.

[0052] As shown in Figure 4, the first flexible wiring board 40 comprises a first insulating film 41 on the back side (the back side of the page in Figure 1), one first electrode connection part 42, multiple parallel wirings 44, a first terminal 43 on the back side, and two connecting parts 45.

[0053] The first electrode connection portion 42 is exposed on the back surface (the side facing the back of the paper in Figure 1) of the first flexible wiring board 40. The first electrode connection portion 42 has a strip shape extending in the extending direction of the first flexible wiring board 40. The first electrode connection portion 42 has a comb-like shape that is repeated in the extending direction of the first flexible wiring board 40. The first electrode connection portion 42 is supported by the first insulating film 41 on the front side. The length of the first electrode connection portion 42 in the extending direction of the first flexible wiring board 40 is equal to the length of the first transparent electrode layer 34 in the first direction D1.

[0054] As shown in Figures 1 and 5, the first electrode connection portion 42 is electrically connected to the first end portions 34BE of the plurality of first segmented electrodes 34B in the first transparent electrode layer 34 via the first conductive adhesive layer 47. The first conductive adhesive layer 47 is made of an anisotropic or isotropic conductive material.

[0055] Multiple parallel wirings 44 extend in a direction intersecting the direction in which the first flexible wiring board 40 extends from one first electrode connection part 42. Multiple parallel wirings 44 are connected in parallel to one first electrode connection part 42. Each parallel wiring 44 is located one at each lead-out. Each parallel wiring 44 is sandwiched between a first insulating film 41 on the front side and a first insulating film 41 on the back side. The back surface of the first flexible wiring board 40 has one first terminal 43 on the back side at each lead-out. The first terminal 43 on the front side and the first terminal 43 on the back side are connected one to each parallel wiring 44. The first flexible wiring board 40 has first terminals 43 as double-sided pads on both the front and back surfaces of the first flexible wiring board 40. In the dimming system 10, the first terminal 43 located on the front surface may be connected to the first wiring 61, or the first terminal 43 located on the back surface may be connected to the first wiring 61. Whether the first terminal 43 connected to the first wiring 61 is on the front or back surface can be appropriately selected in the first direction D1 depending on the arrangement of the drive unit 60, the arrangement of the first wiring 61, the shape of the surrounding structure on which the dimming device 20 is mounted, etc.

[0056] Returning to Figure 4, the connecting portion 45 is located at both ends in the extending direction of the first flexible wiring board 40. The connecting portion 45 is connected to the first electrode connection portion 42. The connecting portion 45 is a comb-tooth electrode connected to both ends of the first electrode connection portion 42. One of the connecting portion 45 is exposed on the back surface of the first flexible wiring board 40 and supported by the first insulating film 41 on the front side. The other connecting portion 45 is exposed on the front surface of the first flexible wiring board 40 and supported by the first insulating film 41 on the back side.

[0057] One connecting portion 45 of the first flexible wiring board 40 is configured to be electrically connected to the other connecting portion 45 of the other first flexible wiring board 40. The two first flexible wiring boards 40 connected by their connecting portions 45 are electrically connected by their first electrode connection portions 42.

[0058] The back surface of the first flexible wiring board 40 is covered by a first insulating film 41 on the back side, except for the first terminal 43, the first electrode connection portion 42, and one connecting portion 45 on the back side. The first insulating film 41 on the back side may be covered by an adhesive layer 41B on the back surface of the first flexible wiring board 40, except for the first electrode connection portion 42. The adhesive layer 41B adheres the first flexible wiring board 40 to the first transparent electrode layer 34.

[0059] The first insulating film 41 on the back side may be a single-layer polyimide film, a multilayer polyimide film joined via an adhesive, a liquid crystal polymer film, a polyethylene terephthalate film, or an aramid cellulose ester film.

[0060] The first electrode connection portion 42, the first terminal 43, and the parallel wiring 44 may be formed from a single copper foil such as rolled copper foil or electrolytic copper foil, or from a single aluminum foil such as rolled aluminum foil or electrolytic aluminum foil.

[0061] The first flexible wiring board 40 may have a weak portion 47B at the lead-out portion. The weak portion 47B may be located at the base end of the lead-out portion. The weak portion 47B is configured to separate the first terminal 43 from the first electrode connection portion 42 between the first electrode connection portion 42 and the first terminal 43. The weak portion 47B may also be a notch located on at least one of the first insulating film 41 on the front side and the first insulating film 41 on the back side. The weak portion 47B may also be a perforation line located on at least one of the first insulating film 41 on the front side and the first insulating film 41 on the back side.

[0062] As shown in Figure 5, the dimming device 20 may be provided with a first sealing portion 46 that covers the first transparent electrode layer 34 and the first flexible wiring board 40 at the portion where the first transparent electrode layer 34 connects to the first flexible wiring board 40. The first sealing portion 46 covers the end face of the dimming layer 33. The first sealing portion 46 reinforces the connection between the first transparent electrode layer 34 and the first flexible wiring board 40.

[0063] [Second flexible wiring board 50] Returning to Figure 1, the second flexible printed circuit board 50 electrically connects the second divided electrode 32B to the drive unit 60. The second flexible printed circuit board 50 is an FPC that applies a control voltage from the drive unit 60 to the second divided electrode 32B.

[0064] The second flexible printed circuit board 50 may be a double-sided FPC, a double-sided exposed FPC, a single-sided FPC, or a multilayer FPC. Below, an example is shown in which the second flexible printed circuit board 50 is a single-sided FPC and has a second terminal 53 on its surface. The second flexible printed circuit board 50 may be a double-sided FPC or a double-sided exposed FPC and may have a second terminal 53 on both its front and back surfaces.

[0065] The second flexible wiring board 50 comprises one second electrode connection portion 52 and one second terminal 53. The second electrode connection portion 52 has a comb-like structure with teeth aligned in a first direction D1. The second electrode connection portion 52 is electrically connected to the second terminal 53. The surface of the second flexible wiring board 50 (the surface facing the viewer in Figure 1) exposes one second terminal 53. The second flexible wiring board 50 has one second terminal 53 for each second electrode connection portion 52. In the direction in which the comb teeth of the second electrode connection portion 52 are aligned, the length of the second electrode connection portion 52 is equal to the length of the second divided electrode 32B.

[0066] As shown in Figures 1 and 6, the second flexible wiring board 50 comprises a second insulating film 51 on the front side (the side facing the viewer in Figure 1), a second insulating film 51 on the back side (the side facing the viewer in Figure 1), a second electrode connection portion 52, and a second terminal 53. The second electrode connection portion 52 is electrically connected to the second terminal 53.

[0067] The second electrode connection portion 52 is supported by the second insulating film 51 on the back side. The second electrode connection portion 52 is connected to the second end portion 32BE of one second divided electrode 32B in the second transparent electrode layer 32 via a second conductive adhesive layer 57. The second conductive adhesive layer 57 is made of an anisotropic or isotropic conductive material.

[0068] The second electrode connection portion 52 and the second terminal 53 are supported on the front side of the second flexible wiring board 50 by the second insulating film 51 on the front side. The second electrode connection portion 52 is supported on the back side of the second insulating film 51 on the back side of the second flexible wiring board 50.

[0069] The second electrode connection portion 52 and the second terminal 53 may be formed from a single copper foil, such as rolled copper foil or electrolytic copper foil, or from a single aluminum foil, such as rolled aluminum foil or electrolytic aluminum foil.

[0070] The dimming device 20 may include a second sealing portion 56 that covers the second transparent electrode layer 32 and the second flexible wiring board 50 at the portion where the second transparent electrode layer 32 connects to the second flexible wiring board 50. The second sealing portion 56 covers the end face of the dimming layer 33. The second sealing portion 56 reinforces the connection between the first divided electrode 34B and the second flexible wiring board 50.

[0071] [Effect] As described above, the first wiring 61 connected to the drive unit 60 of the dimming layer 33 supplies power to the first transparent electrode layer 34 through the first terminal 43 of the first flexible wiring board 40. The arrangement of the first wiring 61 is such that it is connected to one of the first terminals 43 connected in parallel to the first electrode connection unit 42. The common voltage applied to the multiple first terminals 43 is applied to all the first divided electrodes 34B through the first electrode connection unit 42. Then, according to the control voltage applied to each second terminal 53, the dimming layer 33 sandwiched between the first divided electrode 34B and the second divided electrode 32B is driven for each second divided electrode 32B.

[0072] As shown in Figure 7, in the dimming system 10, some of the parallel wirings 44 among the multiple parallel wirings 44 are electrically connected to the first wiring 61. Here, the other parallel wirings 44 among the multiple parallel wirings 44 may be cut at the weak point 47B together with the first insulating film 41 so that they are shorter than the parallel wirings 44 to which the first wiring 61 is connected. In this case, the parallel wirings 44 not connected to the first wiring 61, and the first insulating film 41 covering the parallel wirings 44, constitute a cut mark where the lead portion is separated from the first flexible wiring board 40. The cut mark may be covered with a sealing material to protect the parallel wirings 44 from the outside air. Note that the separation of the lead portion may be performed on the first flexible wiring board 40 after it has been connected to the first transparent electrode layer 34, or on the first flexible wiring board 40 before it has been connected to the first transparent electrode layer 34.

[0073] [effect] As explained above, the following effects can be obtained. (1) The arrangement of the first wiring 61 increases the degree of freedom in the first direction D1 by the amount of the number of first terminals 43. As a result, the mounting burden of the first wiring 61, which is required to adapt the wiring arrangement to the specifications of the dimming device 20, is reduced.

[0074] (2) Multiple first divided electrodes 34B are connected in parallel to the first electrode connection part 42. One second electrode connection part 52 is connected to each second divided electrode 32B. Therefore, even if the first wiring 61 is connected to only some of the multiple first terminals 43, a common voltage can be applied to the multiple first divided electrodes 34B. Then, the dimming layer 33 sandwiched between the first divided electrode 34B and the second divided electrode 32B is driven for each second divided electrode 32B.

[0075] (3) The dimming layer 33 can be processed to overlap the second insulating portion 32A on the first insulating portion 34A in the thickness direction. The process of overlapping the second insulating portion 32A on the first insulating portion 34A is performed, for example, by irradiating the second transparent electrode layer 32 through the first transparent electrode layer 34 and the dimming layer 33 with a laser that insulates the first transparent electrode layer 34. When the thickness of the dimming layer 33 is a thin film of 100 μm or less, the process of irradiating the first transparent electrode layer 34 and the second transparent electrode layer 32 with a laser makes it easy to overlap the second insulating portion 32A on the first insulating portion 34A. For this reason, in a dimming device 20 in which the processing load of the first divided electrode 34B and the second divided electrode 32B is reduced, the mounting load of the first wiring 61 that adapts the wiring arrangement to the specifications of the dimming device 20 is reduced.

[0076] (4) Since multiple first terminals 43 are arranged along the first direction D1, a group of first terminals 43 for applying a common voltage is easily identified by sight. For this reason, it is easy to understand during wiring installation that a common voltage can be applied to multiple first divided electrodes 34B by connecting the first wiring 61 to any of the group of first terminals 43.

[0077] (5) A common voltage is applied from the first end 34BE of the first divided electrode 34B. A control voltage is applied from the second end 32BE of the second divided electrode 32B. As a result, the voltage applied between the first divided electrode 34B and the second divided electrode 32B is made uniform in the second direction D2.

[0078] (6) The first flexible wiring board 40 is equipped with double-sided pads, such as the first terminal 43 on the front side and the first terminal 43 on the back side. In this case, the arrangement of the first wiring 61 is made more flexible on the front and back sides of the first flexible wiring board 40.

[0079] (7) When the end of the first flexible wiring board 40 is provided with a connecting portion 45, the two first flexible wiring boards 40 are electrically connected at their ends. This allows the length of the first flexible wiring board 40, and consequently the length of the dimming device 20 driven by the drive unit 60, to be increased.

[0080] The above-described embodiment can be implemented with the following modifications. Parallel wiring 44 that is not connected to the first wiring 61 may remain in the dimming system 10 without being disconnected from the first flexible wiring board 40. The vulnerable portion 47B for disconnecting the parallel wiring 44 may be omitted from the first flexible wiring board 40. The first terminal 43 that is not connected to the first wiring 61 may be covered with a sealing material to prevent contact with the outside.

[0081] The connecting section 45 may be omitted from the first flexible wiring board 40. The first flexible wiring board 40 may be longer than the length of the dimming sheet 30 in the first direction D1. In this case, the first flexible wiring board 40 may be cut in the middle of the first direction D1 so as to assign one or more first terminals 43 to the dimming sheet 30.

[0082] The first flexible wiring board 40 may have a single-sided pad on at least one of the plurality of first terminals 43. The second flexible wiring board 50 may have two or more second terminals 53 connected in parallel to one second electrode connection portion 52. The second terminals 53 may be double-sided pads. In this configuration as well, the effects similar to those described in (1) to (7) above can be obtained.

[0083] The first insulating portion 34A and the second insulating portion 32A may be composed of multiple line segments extending in mutually different directions, such as in an L-shape. In this case, the direction in which the first divided electrode 34B and the second divided electrode 32B are aligned may be in a direction that intersects with each line segment constituting the first insulating portion 34A and the second insulating portion 32A, or it may be parallel to the direction in which one line segment extends. The direction in which the first terminals 43 are aligned may be parallel to the direction in which the first divided electrode 34B and the second divided electrode 32B are aligned, or it may be in a direction that intersects with it. The direction in which the first terminals 43 are aligned may be in multiple directions that include the direction in which each line segment extends. [Explanation of symbols]

[0084] 10…Dimming system 20… Dimming device 30… Dimmable sheet 31…Second transparent support layer 32...Second transparent electrode layer 32A...Second insulation section 32B…Second divided electrode 32BE…Second end 33…Dimming layer 34...First transparent electrode layer 34A...First insulation section 34B…1st divided electrode 34BE…First end 35...First transparent support layer 40...First flexible wiring board 41...First insulating film 42...First electrode connection section 43...1st terminal 44…Parallel wiring 45…Continuous part

Claims

1. A dimming device, A pair of transparent electrode layers, consisting of a first transparent electrode layer and a second transparent electrode layer, A light-adjusting layer disposed between the first transparent electrode layer and the second transparent electrode layer, A flexible wiring substrate connected to the first transparent electrode layer, Equipped with, Each of the aforementioned transparent electrode layers is It is equipped with multiple divided electrodes that are electrically separated by an insulating part, The aforementioned flexible wiring board is An electrode connection portion connected to the divided electrode of the first transparent electrode layer, The electrode connection portion is connected in parallel to the drive portion for driving the dimming layer, and includes a plurality of terminals for connecting the electrode connection portion to the drive portion. A dimming device characterized by the following features.

2. The plurality of divided electrodes are arranged along the first direction, The electrode connection portion is a first electrode connection portion that extends in the first direction and has a plurality of divided electrodes constituting the first transparent electrode layer connected in parallel. The second transparent electrode layer further comprises a plurality of second electrode connection portions, each of which is connected to one of the divided electrodes constituting the second transparent electrode layer. The dimming device according to claim 1.

3. The first transparent electrode layer is First insulating section and It comprises a plurality of first divided electrodes insulated from each other by the first insulating portion, The aforementioned second transparent electrode layer is A second insulating portion overlapping the first insulating portion in the thickness direction of the dimming layer, The invention comprises a plurality of second divided electrodes, which are insulated from each other by the second insulating portion, The dimming device according to claim 2.

4. The plurality of divided electrodes are arranged along the first direction, The electrode connection portion extends in the first direction, and the plurality of divided electrodes constituting the first transparent electrode layer are connected in parallel. The plurality of terminals are arranged along the first direction. A dimming device according to any one of claims 1 to 3.

5. The divided electrode extends from the second end to the first end in a second direction intersecting the first direction, The first electrode connection portion is formed by connecting the first ends of the multiple divided electrodes in the first transparent electrode layer in parallel. The second electrode connection portion is connected one by one to the second end of the divided electrode in the second transparent electrode layer. The dimming device according to claim 2.

6. The plurality of terminals are arranged at regular intervals along the first direction. The dimming device according to claim 4.

7. The aforementioned terminal is a double-sided pad. A dimming device according to any one of claims 1 to 3.

8. The end of the flexible wiring board is provided with an exposed connecting portion connected to the electrode connection portion, The aforementioned connecting portion is configured to be electrically connected to the aforementioned connecting portion of another flexible wiring board. A dimming device according to any one of claims 1 to 3.

9. The electrode connection portion and the terminal are provided with an insulating film that supports them. The insulating film has a weak portion between the electrode connection portion and the terminal for separating the terminal from the electrode connection portion. A dimming device according to any one of claims 1 to 3.

10. It is a dimming system, A pair of transparent electrode layers, consisting of a first transparent electrode layer and a second transparent electrode layer, A light-adjusting layer disposed between the first transparent electrode layer and the second transparent electrode layer, A flexible wiring substrate electrically connected to the first transparent electrode layer, A drive unit for driving the dimming layer, The drive unit has wiring that electrically connects the flexible wiring board, Equipped with, Each of the aforementioned transparent electrode layers is It is equipped with multiple divided electrodes that are electrically separated by an insulating part, The aforementioned flexible wiring board is An electrode connection portion electrically connected to the first transparent electrode layer, Multiple parallel wirings are connected in parallel to the electrode connection portion and extend from the electrode connection portion, The device comprises the electrode connection portion and an insulating film supporting the parallel wiring, Some of the aforementioned parallel wirings are connected to terminals for connecting the electrode connection part to the drive unit, The other parts of the plurality of parallel wirings form cut marks together with the insulating film so that they are shorter than the aforementioned part. A dimming system characterized by the following features.

11. A flexible wiring board connected to a dimming sheet, The aforementioned dimming sheet is A pair of transparent electrode layers, consisting of a first transparent electrode layer and a second transparent electrode layer, A light-adjusting layer disposed between the first transparent electrode layer and the second transparent electrode layer, Equipped with, Each of the aforementioned transparent electrode layers is It is equipped with multiple divided electrodes that are electrically separated by an insulating part, The aforementioned flexible wiring board is The first transparent electrode layer has one electrode connection portion that extends in the direction in which the divided electrodes are aligned and has comb teeth aligned in the same direction, and the multiple divided electrodes are connected in parallel, The electrode connection portion comprises a plurality of terminals connected in parallel and arranged at regular intervals along the direction, A flexible wiring board characterized by the following.

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