Flexible wiring board and dimming unit

Abstract

The flexible wiring board 40 includes: an insulating layer 41 with a support surface extending in a first direction D1; a first sheet-attached terminal 45A located on the support surface; and a second sheet-attached terminal 45B located on the support surface. The shape of the first sheet-attached terminal 45A is point-symmetrical with respect to a point on a bending line passing through guiding lines 4LA, 4LB, and 4LC extending in the first direction D1, and is similar to the shape of the second sheet-attached terminal 45B. This improves the flexibility of the flexible wiring board having terminals facing opposite directions.

Description

Technical Field

[0001] This disclosure relates to a flexible wiring board having connected terminals facing opposite directions, and a dimming unit having the flexible wiring board. Prior Technology

[0002] A dimming sheet having two transparent electrode layers facing each other exhibits a different light transmittance by applying a voltage to a liquid crystal composition between the transparent electrode layers. The two transparent electrode layers are connected to an external power source via a flexible wiring substrate (see, for example, Patent Documents 1 and 2). An example of the flexible wiring substrate has terminals facing opposite directions. The terminals are connected one by one to the electrode terminals of the dimming sheet.

[0003] For example, as shown in FIG10, the dimming sheet 70 includes a first transparent electrode sheet 71, a second transparent electrode sheet 81, and a dimming layer 91. The dimming layer 91 is located between the first transparent electrode sheet 71 and the second transparent electrode sheet 81. The first transparent electrode sheet 71 includes a first transparent electrode layer 73 and a first support film 72 connected to the dimming layer 91. The second transparent electrode sheet 81 includes a second transparent electrode layer 83 and a second support film 82 connected to the dimming layer 91. The dimming layer 91 located between the first transparent electrode layer 73 and the second transparent electrode layer 83 is driven by a voltage applied between the first transparent electrode layer 73 and the second transparent electrode layer 83.

[0004] The dimming plate 70 has an edge 70E extending in a straight line from the right side to the left side in FIG. 10. The first transparent electrode terminal 73P of the first transparent electrode layer 73 and the second transparent electrode terminal 83P of the second transparent electrode layer 83 are arranged along the edge 70E of the dimming plate 70. The dimming layer 91 is located between the first transparent electrode layer 73 and the second transparent electrode layer 83, with the first transparent electrode terminal 73P and the second transparent electrode terminal 83P exposed from the dimming layer 91.

[0005] The dimming disc 70 is connected to an external power supply 65 via a flexible wiring board 60. The flexible wiring board 60 includes an insulating layer 61, a first conductive layer 62, and a second conductive layer 63. The first support surface 61A of the insulating layer 61 supports the first conductive layer 62. The second support surface 61B of the insulating layer 61, opposite to the first support surface 61A, supports the second conductive layer 63.

[0006] As shown by the dashed lines in Figure 10, the first conductive layer 62 is connected to the external power supply 65 through the through hole in the insulating layer 61. Similarly, the second conductive layer 63 is connected to the external power supply 65. As shown by the dotted chain in Figure 10, the first sheet-attached terminal 62P of the first conductive layer 62 is arranged face-to-face with the first transparent electrode layer 73. The first sheet-attached terminal 62P is attached to the first transparent electrode terminal 73P using a conductive adhesive. The second sheet-attached terminal 63P of the second conductive layer 63 is arranged face-to-face with the second transparent electrode layer 83. The second sheet-attached terminal 63P is attached to the second transparent electrode terminal 83P using a conductive adhesive. [Previous Technical Documents] [Patent Literature]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2007-57925 [Patent Document 2] Japanese Patent Application Publication No. 2020-38265 Summary of the Invention

[0008] [The problem the invention aims to solve]

[0009] On one hand, the flexible wiring substrate 60, in which the first support surface 61A supports the first conductive layer 62 and the second support surface 61B supports the second conductive layer 63, is typically required to have protective layers covering the first conductive layer 62 and the second conductive layer 63, respectively. As a result, the aforementioned double-sided flexible wiring substrate is thicker than the single-sided flexible wiring substrate, thus reducing its flexibility. [Methods used to solve problems]

[0010] The flexible wiring board system for solving the above problems includes: The insulating layer has a supporting surface extending in the first direction; The first sheet is attached to a terminal, located on the aforementioned support surface, and extends in the aforementioned first direction; and The second sheet is attached to the terminal, located on the aforementioned support surface, and extends in the aforementioned first direction. The shape of the first thin sheet connected terminal is point-symmetrical with respect to a point on the bending straight line extending in the first direction, and is point-symmetrical with respect to the shape of the second thin sheet connected terminal.

[0011] The dimming unit for solving the above-mentioned problems includes: a dimming sheet having an edge extending in a first direction; and a flexible wiring substrate attached to the edge. The dimming sheet includes: a first transparent electrode layer having a first transparent electrode terminal on a first electrode surface; a second transparent electrode layer having a second transparent electrode terminal on a second electrode surface; and a dimming layer located between the first electrode surface and the second electrode surface such that the first and second transparent electrode terminals are exposed from the dimming layer. The first and second transparent electrode terminals constitute the edge and are arranged along the first direction. The flexible wiring substrate includes: an insulating layer having a support surface extending in the first direction; a first sheet-attached terminal attached to the first transparent electrode terminal, located on the support surface and extending in the first direction; and a second sheet-attached terminal attached to the second transparent electrode terminal, located on the support surface and extending in the first direction. The aforementioned support surface is bent along a straight line extending in the aforementioned first direction, and the shape of the aforementioned first sheet connected to the terminal is such that the shape of the aforementioned second sheet connected to the terminal is parallel to the aforementioned straight line.

[0012] Based on the above configuration, a support surface is divided into a first surface region and a second surface region by a bent straight line. When a support surface is bent along the bent straight line, the first surface region faces the first side opposite to the first surface region, while the second surface region faces the second side opposite to the first side. Furthermore, the first and second sheet-attached terminals face opposite sides. Therefore, a flexible wiring board with two sheet-attached terminals on one support surface can be used as a double-sided form.

[0013] Furthermore, the shape of the first sheet-attached terminal, viewed from a point on the bending line, is identical to the shape of the second sheet-attached terminal, viewed from the same point on the bending line. When a support surface bends along a bending line, the shape of the first sheet-attached terminal becomes identical to the shape of the second sheet-attached terminal, which runs parallel to the bending line. This allows the sheet-attached terminals to be attached one by one to two connecting objects arranged along the extending bending line and having identical shapes.

[0014] The aforementioned flexible wiring substrate may also have a vulnerable portion on the aforementioned bending line, which induces the aforementioned flexible wiring substrate to bend on the aforementioned bending line. Based on the above configuration, the load on the flexible wiring board when bending a straight line extending in the first direction can be reduced, and it is also easier to utilize the above-mentioned double-sided flexible wiring board.

[0015] The flexible wiring board for solving the above-mentioned problems includes: an insulating layer having a support surface extending in a first direction; a first sheet-attached terminal located on the support surface; and a second sheet-attached terminal located on the support surface. Furthermore, a weak portion is provided on the aforementioned bending line, which induces the flexible wiring board to bend along the bending line extending in the first direction; the first sheet-attached terminal is separated from the second sheet-attached terminal in the first direction and is located on the opposite side of the second sheet-attached terminal relative to the bending line.

[0016] The dimming unit for solving the above-mentioned problems includes: a dimming sheet extending along an edge in a first direction; and a flexible wiring substrate attached to the edge. The dimming sheet includes: a first transparent electrode layer having a first transparent electrode terminal on a first electrode surface; a second transparent electrode layer having a second transparent electrode terminal on a second electrode surface; and a dimming layer located between the first electrode surface and the second electrode surface such that the first and second transparent electrode terminals are exposed from the dimming layer. The first and second transparent electrode terminals constitute the edge and are arranged along the first direction. The flexible wiring substrate includes: an insulating layer having a support surface extending along the first direction; a first sheet-attached terminal attached to the first transparent electrode terminal and located on the support surface; and a second sheet-attached terminal attached to the second transparent electrode terminal and located on the support surface. The aforementioned support surface is bent along a straight line extending in the aforementioned first direction, the aforementioned first sheet attached terminal is separated from the aforementioned second sheet attached terminal in the aforementioned first direction, and the aforementioned support surface is located on the opposite side of the aforementioned second sheet attached terminal relative to the aforementioned straight line.

[0017] According to the aforementioned flexible wiring board, a support surface is divided into two surface regions by a series of bending lines defined by the weak points. When one support surface bends along a bending line, one surface region faces a first side relative to the support surface, while the other surface region faces a second side opposite to the first side. Furthermore, the first sheet-attached terminal faces the first side relative to the support surface, while the second sheet-attached terminal faces the second side relative to the support surface. Thus, a flexible wiring board having two sheet-attached terminals on one support surface can be used as a double-sided form.

[0018] In the aforementioned flexible substrate, the insulating layer may also include: a first support sheet supporting the terminal to which the first sheet is attached and extending in the aforementioned first direction; and a second support sheet supporting the terminal to which the second sheet is attached and extending in the aforementioned first direction. The portion of the first support sheet that contacts the second support sheet is at the front end of the first support sheet in the aforementioned first direction, and the portion of the second support sheet that contacts the first support sheet is at the base end of the second support sheet in the aforementioned first direction. Furthermore, the aforementioned flexible wiring substrate may also include a vulnerable portion located at the junction of the front end and the base end.

[0019] According to the aforementioned flexible wiring board, the bending of the first sheet connected to the terminal and the second sheet connected to the terminal to the terminal to the terminal to the terminal to the terminal to the terminal to the terminal to the terminal to the terminal to the terminal is performed at the junction of the front end of the first support sheet and the base end of the second support sheet. In this way, the load required for bending can be reduced compared to bending the entire first support sheet or bending the entire second support sheet.

[0020] In the aforementioned flexible wiring substrate, the aforementioned insulating layer may also include a first support piece that supports the aforementioned first sheet-attached terminal and extends in the aforementioned first direction. The aforementioned first support piece may also include: a first fold-back portion included at the front end of the aforementioned first support piece in the aforementioned first direction and extending in the aforementioned first direction; and a first terminal support portion for the aforementioned first sheet-attached terminal. The aforementioned first fold-back portion may also include a wiring located on the opposite side of the aforementioned first terminal support portion relative to the aforementioned bent straight line, extending from the aforementioned first sheet-attached terminal toward the aforementioned second sheet-attached terminal in the aforementioned first direction. Furthermore, the aforementioned flexible wiring substrate includes a vulnerable portion located at the junction of the aforementioned first fold-back portion and the aforementioned first terminal support portion.

[0021] According to the aforementioned flexible wiring board, since the wiring connected to the first thin-film connected terminal extends towards the second thin-film connected terminal, it is easy to aggregate the wiring connected to the first thin-film connected terminal and the wiring connected to the second thin-film connected terminal. In this way, the flexible wiring board can also give the aggregated wiring a unified look as if it were pulled out from a dimming sheet, thereby improving the design of the dimming unit. Furthermore, since the first terminal support portion and the first fold-back portion are distinguished by the bending straight lines defined by the weak points, the first terminal support portion and the first fold-back portion can be bent in opposite directions by bending the first thin-film connected terminal and the second thin-film connected terminal. In this way, these can be bent along the bending straight lines in a manner where the first thin-film connected terminal and the first fold-back portion overlap. Moreover, it can prevent the first fold-back portion from extending beyond the edge of the dimming sheet formed by attaching the first connected terminal to the edge. As a result, the flexible wiring board can also create a sense of integration between the dimming sheet and the flexible wiring board, thereby improving the design flexibility as a dimming unit.

[0022] In the aforementioned flexible wiring substrate, the aforementioned insulating layer may also include a second support piece that supports the aforementioned second sheet connected to the terminal and extends in the aforementioned first direction. The aforementioned second support piece may also include: a second fold-back portion, included at the base end of the aforementioned second support piece in the aforementioned first direction and extending in the aforementioned first direction; and a second terminal support portion for the aforementioned second sheet connected to the terminal. The aforementioned second fold-back portion may also include a wiring located on the opposite side of the aforementioned second terminal support portion relative to the aforementioned bent straight line, extending from the aforementioned second sheet connected to the terminal toward the aforementioned first sheet connected to the terminal in the aforementioned first direction. Furthermore, the aforementioned flexible wiring substrate may also include the aforementioned vulnerable portion located at the junction of the aforementioned second fold-back portion and the aforementioned second terminal support portion.

[0023] According to the aforementioned flexible wiring board, since the wiring connected to the second sheet-attached terminal extends towards the first sheet-attached terminal, it is easy to aggregate the wiring connected to the first sheet-attached terminal and the wiring connected to the second sheet-attached terminal. This also allows the flexible wiring board to give the aggregated wiring a unified appearance as if it were drawn from a single dimming sheet, thus improving the design of the dimming unit. Furthermore, since the second terminal support and the second fold-back portion are distinguished by the bending straight lines defined by the weak points, the second terminal support and the second fold-back portion can be bent by bending the first sheet-attached terminal and the second sheet-attached terminal in opposite directions. This allows bending along the bending straight lines in a manner where the second sheet-attached terminal and the second fold-back portion overlap. Moreover, it prevents the second fold-back portion from extending beyond the edge of the dimming sheet where the second sheet-attached terminal is attached. As a result, the flexible wiring board can also create a sense of integration between the dimming sheet and the flexible wiring board, thereby improving the design flexibility as a dimming unit.

[0024] In the aforementioned flexible wiring substrate, the portion of the first support piece that connects to the second support piece may also be the front end of the first support piece in the first direction, and the portion of the second support piece that connects to the first support piece may also be the base end of the second support piece in the first direction. Furthermore, the aforementioned flexible wiring substrate may also have the aforementioned vulnerable portion located at the junction of the front end and the base end.

[0025] According to the aforementioned flexible wiring board, the bending of the first sheet connected to the terminal and the second sheet connected to the terminal ...

[0026] The aforementioned flexible wiring board may also include external connection terminals, which are located at the ends of the aforementioned wiring extending from the terminal attached to the first sheet and the ends of the aforementioned wiring extending from the terminal attached to the second sheet. The aforementioned external connection terminals may also be located in the portion of the aforementioned flexible wiring board that connects to the aforementioned first fold-back portion, and extend from the aforementioned first fold-back portion relative to the aforementioned straight bend, toward the opposite side of the aforementioned first fold-back portion.

[0027] According to the aforementioned flexible wiring board, the external connection terminal extends from the first fold-back portion on the opposite side of the bending line towards the first fold-back portion. That is, the external connection terminal extends from the first fold-back portion on the same side as the first terminal support portion relative to the bending line. Furthermore, when the first terminal support portion and the first fold-back portion bend at the bending line, the external connection terminal extends from the first fold-back portion on the opposite side of the bending line towards the first terminal support portion. This allows the external connection terminal to be pulled out relative to the bending line towards the side opposite to the connection target of the first terminal support portion. Moreover, the flexible wiring board also provides a unified feel to the wiring gathered in one place, as if pulled out from a single dimming disc, thus improving the design versatility of the dimming unit. Simple Explanation of the Diagram

[0028] Figure 1 is a top view showing a magnified view of the transparent electrode terminals in the dimming film. Figure 2 shows the cross-section viewed from line II-II in Figure 1. Figure 3 shows the cross-section viewed from line III-III in Figure 1. Figure 4 is a top view showing the planar structure of the flexible wiring board. Figure 5 shows the cross-section as viewed from line VV in Figure 4. Figure 6 is a step diagram illustrating the method of attaching a flexible wiring board to a dimming film. Figure 7 is a step diagram illustrating the method of attaching a flexible wiring board to a dimming film. Figure 8 is a step diagram illustrating the method of attaching a flexible wiring substrate to a dimming film. Figure 9 is a cross-sectional view showing the configuration of the flexible wiring board in the dimming unit. Figure 10 is a cross-sectional view showing the configuration of the flexible wiring board in the dimming unit. Implementation

[0029] [The form in which the invention is carried out]

[0030] This paper describes one embodiment of a flexible wiring board and a dimming unit. First, the configuration of a dimming sheet, which is intended to be attached to the flexible wiring board, will be explained. Second, the configuration of the flexible wiring board will be explained. Then, a dimming unit comprising a dimming sheet and a flexible wiring board attached to the dimming sheet will be described.

[0031] [Dimming filter] As shown in Figure 1, the dimming plate 10 includes an edge 10E extending in a straight line along a first direction D1. The dimming plate 10 includes a first transparent electrode 11, a second transparent electrode 21, and a dimming layer 31 (see Figure 2). The dimming layer 31 is located between the first transparent electrode 11 and the second transparent electrode 21. The dimming plate 10 divides the space in which it exists into two spaces. The space in contact with the first transparent electrode 11 is the first space. The space in contact with the second transparent electrode 21 is the second space.

[0032] As shown in Figure 2, the first transparent electrode sheet 11 includes a first support film 14 and a first transparent electrode layer 15. The second transparent electrode sheet 21 includes a second support film 24 and a second transparent electrode layer 25. The first transparent electrode layer 15 is disposed on the side of the second transparent electrode sheet 21 relative to the first support film 14 and is in contact with the dimming layer 31. The second transparent electrode layer 25 is disposed on the side of the first transparent electrode sheet 11 relative to the second support film 24 and is in contact with the dimming layer 31. The dimming layer 31, located between the first transparent electrode layer 15 and the second transparent electrode layer 25, is driven by a voltage applied between the first transparent electrode layer 15 and the second transparent electrode layer 25. Furthermore, the dimming sheet 10 may also have an alignment layer between the first transparent electrode layer 15 and the dimming layer 31. Additionally, the dimming sheet 10 may also have an alignment layer between the second transparent electrode layer 25 and the dimming layer 31.

[0033] Supporting membranes 14 and 24 respectively possess light transmittance (transmitting visible light) and electrical insulation. The materials constituting supporting membranes 14 and 24 are organic or inorganic polymer compounds. An example of an organic polymer compound is at least one selected from the group consisting of polyester, polyacrylate, polycarbonate, and polyolefin. An example of an inorganic polymer compound is at least one selected from the group consisting of silicon dioxide, silicon oxynitride, and silicon nitride.

[0034] The transparent electrode layers 15 and 25 respectively possess light transmittance and electrical conductivity, allowing visible light to pass through. An example of the materials constituting the transparent electrode layers 15 and 25 is at least one selected from the group consisting of indium tin oxide, fluorine-doped tin oxide, tin oxide, zinc oxide, carbon nanotubes, and poly(3,4-ethylenedioxythiophene).

[0035] The dimming layer 31 achieves a difference in light transmittance between the applied voltage and the unapplied voltage by applying a voltage. An example of the dimming layer 31 comprises a transparent organic polymer layer and a liquid crystal composition. The transparent organic polymer layer defines gaps filled by the liquid crystal composition between the first transparent electrode layer 15 and the second transparent electrode layer 25. The liquid crystal composition fills the gaps in the transparent organic polymer layer. The liquid crystal composition contains a liquid crystal compound. An example of the liquid crystal compound is composed of compounds containing Schiff bases, azo compounds, azoxy compounds, biphenyl compounds, terphenyl compounds, benzoic acid esters, tolan compounds, pyrimidine compounds, cyclohexane carboxylic acid esters, phenylcyclohexane compounds, and diphenylacetylene compounds. At least one of the groups of dioxane compounds selected.

[0036] One example of the retention type of the liquid crystal composition in the dimming layer 31 is any one selected from the group consisting of polymer network type, polymer dispersion type, and capsule type. The polymer network type has a transparent polymer network with a three-dimensional mesh structure, retaining the liquid crystal composition in the interconnected mesh-like voids. The polymer network is an example of a transparent organic polymer layer. The polymer dispersion type has a majority of isolated voids in the transparent organic polymer layer, retaining the liquid crystal composition in the voids dispersed in the polymer layer. The capsule type retains a capsule-shaped liquid crystal composition within the transparent organic polymer layer. Furthermore, in addition to the aforementioned liquid crystal compound, the liquid crystal composition may also contain monomers for forming the transparent organic polymer layer and dichroic pigments.

[0037] Referring back to Figure 1, in the edge 10E of the dimming plate 10, the first transparent electrode 11 and the dimming layer 31 have a first terminal opening 12. The first terminal opening 12 extends from the edge 10E of the dimming plate 10 toward the inside of the dimming plate 10. The first terminal opening 12 exposes a portion of the second transparent electrode 21 in the first space defined by the dimming plate 10.

[0038] In the edge portion 10E, the second transparent electrode sheet 21 and the dimming layer 31 have a second terminal opening 22. The second terminal opening 22 extends from the edge portion 10E of the dimming sheet 10 toward the inside of the dimming sheet 10. The second terminal opening 22 exposes a portion of the transparent electrode sheet 21 toward the second space defined by the dimming sheet 10.

[0039] The first terminal opening 12 and the second terminal opening 22 are arranged with a gap along the edge 10E of the dimming plate 10. The first terminal opening 12 has a shape equivalent to that of the second terminal opening 22 parallel to the first direction D1. Alternatively, the first terminal opening 12 may have a shape different from that of the second terminal opening 22 parallel to the first direction D1.

[0040] In Figure 1, from the viewpoint of easily explaining the positions of the terminal openings 12 and 22 in the thickness direction of the dimming sheet 10, the portion of the first transparent electrode sheet 11 exposed toward the second space is surrounded by a dashed line. Furthermore, the portion of the second transparent electrode sheet exposed toward the first space is an additional point.

[0041] As shown in Figure 2, in the first transparent electrode layer 15, the first electrode surface 15S facing the dimming layer 31 extends from the second terminal opening 22 to the edge 10E. The second terminal opening 22 distinguishes the first transparent electrode terminal 13, which is a part of the first electrode surface 15S, in the first transparent electrode layer 15. The first transparent electrode terminal 13 is surrounded by the second terminal opening 22 and the edge 10E of the dimming plate 10 in the first electrode surface 15S.

[0042] The second terminal opening 22 can also be formed by cutting off a portion of the second transparent electrode sheet 21 and a portion of the dimming layer 31. Alternatively, the second terminal opening 22 can also be formed in the first transparent electrode sheet 11 beforehand as a portion where the second transparent electrode sheet 21 and the dimming layer 31 do not face each other.

[0043] The first transparent electrode terminal 13 is attached to the flexible wiring substrate via a conductive adhesive. The conductive adhesive is at least one selected from the group consisting of anisotropic conductive film (ACF), anisotropic conductive paste (ACP), isotropic conductive film (ICF), and isotropic conductive paste (ICP).

[0044] As shown in Figure 3, the second electrode surface 23S facing the dimming layer 31 in the second transparent electrode layer 25 extends from the first terminal opening 12 to the edge 10E. The first terminal opening 12 distinguishes the second transparent electrode terminal 23, which is a part of the second transparent electrode layer 25. The second transparent electrode terminal 23 is surrounded by the first terminal opening 12 and the edge 10E of the dimming plate 10 in the second electrode surface 23S.

[0045] The first terminal opening 12 can also be formed by cutting off a portion of the first transparent electrode sheet 11 and a portion of the dimming layer 31. Alternatively, the first terminal opening 12 can also be formed in the second transparent electrode sheet 21 beforehand as a portion where the first transparent electrode sheet 11 and the dimming layer 31 do not face each other. Furthermore, the second transparent electrode terminal 23 is also connected to the flexible wiring substrate through a conductive adhesive.

[0046] The first transparent electrode terminal 13 has a shape similar to that of the second transparent electrode terminal 23 parallel to the first direction D1. Alternatively, the first transparent electrode terminal 13 may have a shape different from that of the second transparent electrode terminal 23 parallel to the first direction D1. The dimming layer 31 is located between the first transparent electrode layer 15 and the second transparent electrode layer 25, with both the first transparent electrode terminal 13 and the second transparent electrode terminal 23 exposed from the dimming layer 31.

[0047] Flexible wiring board As shown in Figure 4, the flexible wiring substrate 40 has a strip extending in the first direction D1. The flexible wiring substrate 40 includes an insulating layer 41, a protective layer 42, and a conductive layer 45. The shape of the insulating layer 41 mimics the shape of the flexible wiring substrate 40. The insulating layer 41 is a resin substrate sheet. In Figure 4, the space in contact with the protective layer 42 in the two spaces defined by one surface of the flexible wiring substrate 40 is the first space. The space in contact with the insulating layer 41 in the two spaces defined by the surface of the flexible wiring substrate 40 is the second space.

[0048] The flexible wiring board 40 includes a plurality of bend-inducing recesses W1 arranged in a first direction D1 and a plurality of bend-inducing through holes W2 arranged in the first direction D1. The bend-inducing recesses W1 have a shape recessed in the first direction D1 or in the opposite direction to the first direction D1 within the outline of the flexible wiring board 40. The bend-inducing through holes W2 are flat elliptical holes extending in the first direction D1. The bend-inducing recesses W1 and the bend-inducing through holes W2 are located on a straight bend extending in the first direction D1. The bend-inducing recesses W1 and the bend-inducing through holes W2 are examples of vulnerable parts.

[0049] As shown in Figure 5, the conductive layer 45 is located between the insulating layer 41 and the protective layer 42. The insulating layer 41 supports the entire conductive layer 45. A supporting surface 41S is located on the surface of the insulating layer 41 in Figure 5. The protective layer 42 covers another portion of the conductive layer 45, exposing a portion of it. The portion of the conductive layer 45 exposed from the protective layer 42 is connected to the dimming disc 10 or an external power supply.

[0050] The flexible wiring substrate 40 is a flexible printed circuit board (FPC). The material constituting the insulating layer 41 is an insulating organic polymer compound or an insulating inorganic-organic composite material. Similarly, the material constituting the protective layer 42 is also an insulating organic polymer compound. An example of the materials constituting the insulating layer 41 and the protective layer 42 is at least one selected from the group consisting of polyimide and polyester, respectively. An example of the material constituting the conductive layer 45 is at least one selected from the group consisting of copper thin film, aluminum thin film, and nickel thin film.

[0051] [Insulation layer 41] Returning to Figure 4, the insulating layer 41 is imaginarily divided equally in the first direction D1 into a first support sheet 4A located on the left side of Figure 4 and a second support sheet 4B located on the right side of Figure 4. The first support sheet 4A and the second support sheet 4B are integral. The first support sheet 4A and the second support sheet 4B constitute a resin sheet. A resin sheet can be a single-layer structure composed of a single resin film, or it can be a laminated structure composed of two or more resin films.

[0052] The first support piece 4A includes a base end portion in the insulating layer 41 in the first direction D1. The first support piece 4A has a strip extending in the first direction D1. The first base end portion 4AT of the first support piece 4A includes the base end portion in the first direction D1 of the first support piece 4A. The first front end portion 4AE of the first support piece 4A includes the front end portion in the first direction D1 of the first support piece 4A. The first base end portion 4AT constitutes the base end portion in the insulating layer 41 in the first direction D1. The first front end portion 4AE is the portion in the first support piece 4A that connects to the second support piece 4B.

[0053] The second support piece 4B includes the front end portion of the insulating layer 41 in the first direction D1. The second support piece 4B has a strip-like shape extending in the first direction D1. The length of the second support piece 4B in the first direction D1 is approximately equal to the length of the first support piece 4A in the first direction D1. The second base end portion 4BT of the second support piece 4B includes the base end of the second support piece 4B in the first direction D1. The second front end portion 4BE of the second support piece 4B includes the front end portion of the second support piece 4B in the first direction D1. The second front end portion 4BE constitutes the front end portion of the insulating layer 41 in the first direction D1. The second base end portion 4BT is the portion of the second support piece 4B that is connected to the first support piece 4A.

[0054] In the insulating layer 41, the first front end portion 4AE of the first support piece 4A is integral with the second base end portion 4BT of the second support piece 4B. The boundary between the first front end portion 4AE of the first support piece 4A and the second base end portion 4BT of the second support piece 4B is located approximately at the center of the first direction D1 in the insulating layer 41. The boundary line between the first front end portion 4AE and the second base end portion 4BT is located on the third guiding straight line 4LC extending along the first direction D1. The boundary line between the first front end portion 4AE and the second base end portion 4BT is sandwiched by a bending guiding recess W1 recessed in the first direction D1 and a bending guiding recess W1 recessed in the opposite direction to the first direction D1. The two bending guiding recesses W1 that hold the boundary line between the first front end portion 4AE and the second base end portion 4BT induce bending of the flexible wiring substrate 40 on the guiding straight line 4LC.

[0055] The first support piece 4A includes: a strip-shaped first fold-back portion 4A1 extending in a first direction D1; and a strip-shaped first terminal support portion 4A2 extending in the first direction D1. The first fold-back portion 4A1 and the first terminal support portion 4A2 are arranged parallel to each other in a direction orthogonal to the first direction D1. The length of the first direction D1 in the first fold-back portion 4A1 is longer than the length of the first direction D1 in the first terminal support portion 4A2. The base end portion of the first direction D1 in the first fold-back portion 4A1 and the base end portion of the first direction D1 in the first terminal support portion 4A2 are formed as the first base end portion 4AT in the first support piece 4A. The front end portion of the first direction D1 in the first fold-back portion 4A1 is the first front end portion 4AE in the first support piece 4A.

[0056] The first fold-back portion 4A1 is integral with the first terminal support portion 4A2. The boundary line between the first fold-back portion 4A1 and the first terminal support portion 4A2 is located on the first guiding straight line 4LA extending along the first direction D1. The boundary line between the first fold-back portion 4A1 and the first terminal support portion 4A2 is sandwiched by a bending guiding recess W1 recessed in the first direction D1 and a bending guiding recess W1 recessed in the opposite direction to the first direction D1. Five bending guiding through holes W2 are located on the boundary line between the first fold-back portion 4A1 and the first terminal support portion 4A2. The two bending guiding recesses W1 sandwiching the boundary line between the first fold-back portion 4A1 and the first terminal support portion 4A2 are bent in the guiding straight line 4LA to induce the insulating layer 41 to bend. In addition, the five bending-induced through holes W2 located on the boundary line between the first fold-back section 4A1 and the first terminal support section 4A2 also induce the insulation layer 41 to bend along the induced straight line 4LA.

[0057] The second support piece 4B comprises: a strip-shaped second fold-back portion 4B1 extending in the first direction D1; and a strip-shaped second terminal support portion 4B2 extending in the first direction D1. The second fold-back portion 4B1 and the second terminal support portion 4B2 are arranged parallel to each other in a direction orthogonal to the first direction D1. The length of the first direction D1 in the second fold-back portion 4B1 is longer than the length of the first direction D1 in the second terminal support portion 4B2. The front end portion of the first direction D1 in the second fold-back portion 4B1 and the front end portion of the first direction D1 in the second terminal support portion 4B2 constitute the second front end portion 4BE of the second support piece 4B. The base end portion of the first direction D1 in the second fold-back portion 4B1 constitutes the second base end portion 4BT of the second support piece 4B.

[0058] The second fold-back section 4B1 is integral with the second terminal support section 4B2. The boundary line between the second fold-back section 4B1 and the second terminal support section 4B2 is located on the second guiding straight line 4LB extending in the first direction D1. The boundary line between the second fold-back section 4B1 and the second terminal support section 4B2 is sandwiched by two bending guiding recesses W1. Five bending guiding through holes W2 are located on the boundary line between the second fold-back section 4B1 and the second terminal support section 4B2. The two bending guiding recesses W1 sandwiching the boundary line between the second fold-back section 4B1 and the second terminal support section 4B2 are bent in the guiding insulating layer 41 of the guiding straight line 4LB. In addition, the five bending guiding through holes W2 located on the boundary line between the second fold-back section 4B1 and the second terminal support section 4B2 are also bent in the guiding insulating layer 41 of the guiding straight line 4LB.

[0059] The flexible wiring board 40 has three imaginary directional lines 4LA, 4LB, and 4LC extending in the first direction D1. The three directional lines 4LA, 4LB, and 4LC are located on a bent straight line extending in the first direction D1.

[0060] The first reversing section 4A1 is located on the side opposite to the first terminal support section 4A2 relative to the guide line 4LA. The second reversing section 4B1 is located on the side opposite to the second terminal support section 4B2 relative to the guide line 4LB. The first reversing section 4A1 is located on the side opposite to the second reversing section 4B1 relative to a bend line through which the three guide lines 4LA, 4LB, and 4LC pass. The first terminal support section 4A2 is located on the side opposite to the second terminal support section 4B2 relative to a bend line through which the three guide lines 4LA, 4LB, and 4LC pass.

[0061] The shape of the first terminal support 4A2 is point-symmetric to the shape of the second terminal support 4B2 with respect to a point on a bent straight line through which the three guide lines 4LA, 4LB, and 4LC pass. For example, the shape of the first terminal support 4A2 is point-symmetric to the shape of the second terminal support 4B2 with respect to a point on a bent straight line through which the three guide lines 4LA, 4LB, and 4LC pass and located at the midpoint between the first terminal support 4A2 and the second terminal support 4B2.

[0062] The front end of the first fold-back section 4A1 is connected to the external terminal support section 48. The external terminal support section 48 is located on the side opposite to the first fold-back section 4A1 relative to the guide line 4LA. The external terminal support section 48 extends from the front end of the first fold-back section 4A1 in a direction orthogonal to the first direction D1, and is located on the same side as the first terminal support section 4A2 relative to the guide line 4LA.

[0063] [Conductive layer 45] The conductive layer 45 is divided into a first conductive layer and a second conductive layer in the first direction D1. The first conductive layer is located on the left side of the conductive layer 45 in Figure 4. The second conductive layer is located on the right side of the conductive layer 45 in Figure 4. The first conductive layer and the second conductive layer are electrically insulated from each other.

[0064] The first conductive layer is composed of a first sheet-mounted terminal 45A extending in a first direction D1 and a first fold-back wiring 43A extending in the first direction D1. The first sheet-mounted terminal 45A and the first fold-back wiring 43A are arranged parallel to each other in a direction orthogonal to the first direction D1. The length of the first direction D1 in the first sheet-mounted terminal 45A is longer than the length of the first direction D1 in the first fold-back wiring 43A. The base end of the first direction D1 in the first sheet-mounted terminal 45A and the base end of the first direction D1 in the first fold-back wiring 43A constitute the base end of the first direction D1 in the first conductive layer.

[0065] The first sheet-connected terminal 45A has comb-shaped terminals arranged in the first direction D1. The entire system of the first sheet-connected terminal 45A is supported by the first terminal support portion 4A2 of the first support piece 4A. The entire system of the first fold-back wiring 43A is supported by the first fold-back portion 4A1 of the first support piece 4A and the external terminal support portion 48.

[0066] The boundary line between the first sheet-attached terminal 45A and the first foldback wiring 43A is located on the first induced straight line 4LA. The first sheet-attached terminal 45A is integral with the first foldback wiring 43A and is electrically connected to the first foldback wiring 43A through the periphery of the bending induced through-holes W2. The five bending induced through-holes W2 are located on the boundary line between the first sheet-attached terminal 45A and the first foldback wiring 43A. The five bending induced through-holes W2 located on the boundary line between the first sheet-attached terminal 45A and the first foldback wiring 43A, like the first support sheet 4A, induce the conductive layer 45 to bend on the induced straight line 4LA.

[0067] The first thin sheet is connected to terminal 45A, which is exposed from the protective layer 42 towards the first space. The first foldback wiring 43A is covered by the protective layer 42 on the side of the first space opposite to the first foldback wiring 43A.

[0068] The leading end of the first direction D1 of the first foldback wiring 43A is bent in a direction orthogonal to the first direction D1. The leading end of the first direction D1 of the first foldback wiring 43A is the first power supply terminal 42AT, and is supported by the external terminal support 48. The first power supply terminal 42AT, like the first sheet-attached terminal 45A, is exposed from the protective layer 42 toward the first space.

[0069] The second conductive layer is composed of a second sheet-like bonding terminal 45B extending in the first direction D1 and a second strip-like fold-back wiring 43B extending in the first direction D1. The second sheet-like bonding terminal 45B and the second fold-back wiring 43B are arranged parallel to each other in a direction orthogonal to the first direction D1. The length of the second sheet-like bonding terminal 45B in the first direction D1 is longer than the length of the second fold-back wiring 43B in the first direction D1. The front end of the second sheet-like bonding terminal 45B in the first direction D1 and the front end of the second fold-back wiring 43B in the first direction D1 constitute the front end of the second conductive layer in the first direction D1.

[0070] The second sheet-connected terminal 45B has comb-shaped terminals arranged in the first direction D1. The entire system of the second sheet-connected terminal 45B is supported by the second terminal support portion 4B2 of the second support piece 4B. The entire system of the second fold-back wiring 43B is supported by the second fold-back portion 4B1 of the second support piece 4B, the front end of the first support piece 4A, and the external terminal support portion 48.

[0071] The boundary line between the second sheet-attached terminal 45B and the second foldback wiring 43B is located on the second induced straight line 4LB. The second sheet-attached terminal 45B is integral with the second foldback wiring 43B and is electrically connected to the second foldback wiring 43B through the periphery of the bending induced through-holes W2. The five bending induced through-holes W2 are located on the boundary line between the second sheet-attached terminal 45B and the second foldback wiring 43B. Similar to the second support sheet 4B, the five bending induced through-holes W2 located on the boundary line between the second sheet-attached terminal 45B and the second foldback wiring 43B induce bending of the conductive layer 45 on the induced straight line 4LB.

[0072] The second sheet-attached terminal 45B, like the first sheet-attached terminal 45A, is exposed from the protective layer 42 towards the first space. The second fold-back wiring 43B, like the first fold-back wiring 43A, is covered by the protective layer 42 on the side of the first space opposite to the second fold-back wiring 43B. The base end of the second fold-back wiring 43B in the first direction D1 is bent once in a direction orthogonal to the first direction D1 and once in a direction opposite to that direction. The base end of the second fold-back wiring 43B in the first direction D1 is bent only once, crossing the junction of the first support piece 4A and the second support piece 4B, and only once from the front end of the first support piece 4A towards the external terminal support portion 48. The base end of the second fold-back wiring 43B in the first direction D1 is the second power supply terminal 42BT and is supported on the external terminal support portion 48. The second power supply terminal 42BT, like the second sheet connected terminal 45B, is exposed from the protective layer 42 towards the first space.

[0073] The first sheet-attached terminal 45A is located on the opposite side of the first foldback wiring 43A relative to the guide line 4LA. The second sheet-attached terminal 45B is located on the opposite side of the second foldback wiring 43B relative to the guide line 4LB. The first sheet-attached terminal 45A is located on the opposite side of the second sheet-attached terminal 45B relative to a bend line through which the three guide lines 4LA, 4LB, and 4LC pass. The first foldback wiring 43A extends from the first sheet-attached terminal 45A toward the second sheet-attached terminal 45B. The second foldback wiring 43B extends from the second sheet-attached terminal 45B toward the first sheet-attached terminal 45A.

[0074] The shape of the first sheet-attached terminal 45A is point-symmetric to the shape of the second sheet-attached terminal 45B relative to a point on a bend line through which the three guide lines 4LA, 4LB, and 4LC pass. For example, the shape of the first sheet-attached terminal 45A is point-symmetric to the shape of the second sheet-attached terminal 45B relative to a point on a bend line through which the three guide lines 4LA, 4LB, and 4LC pass and located midway between the first sheet-attached terminal 45A and the second sheet-attached terminal 45B.

[0075] The external terminal support 48, the front end of the first foldback wiring 43A (i.e., the first power supply terminal 42AT), and the base end of the second foldback wiring 43B (i.e., the second power supply terminal 42BT) together constitute an external connection terminal.

[0076] [Dimming Unit] Next, the method of attaching the flexible wiring substrate 40 to the dimming sheet 10 will be described, that is, the method of manufacturing the dimming unit.

[0077] As shown in Figure 6, when the flexible wiring board 40 is attached to the dimming sheet 10, firstly, the flexible wiring board 40 is arranged so that the first thin-film bonding terminal 45A and the first transparent electrode terminal 13 face each other. Furthermore, the flexible wiring board 40 is arranged so that the guiding straight lines 4LA, 4LB, and 4LC in the flexible wiring board 40 approximately coincide with the edge 10E of the dimming sheet 10. Then, the first thin-film bonding terminal 45A and the first transparent electrode terminal 13 are bonded together using a conductive adhesive.

[0078] Furthermore, the first thin-film bonding terminal 45 faces the first space defined by the dimming sheet 10, while the first transparent electrode terminal 13 faces the second space defined by the dimming sheet 10. As shown by the dotted lines in FIG6, the second folded-back portion 4B1 and the external terminal support portion 48 are disposed on the side opposite to the second space of the second transparent electrode sheet 21. Also, similar to the first thin-film bonding terminal 45A, the second thin-film bonding terminal 45B also faces the first space defined by the dimming sheet 10.

[0079] As shown in Figure 7, when the first sheet is bonded to the first transparent electrode terminal 13, the first fold-back portion 4A1 folds back along the guiding line 4LA. The first fold-back portion 4A1, which folds back along the guiding line 4LA, is positioned on the opposite side of the first transparent electrode sheet 11 from the side of the second transparent electrode sheet 21, and is covered by the first transparent electrode sheet 11. That is, the first fold-back portion 4A1 is positioned relative to the first transparent electrode sheet 11 on the side of the first space.

[0080] At this time, the second fold-back portion 4B1, which is connected to the first fold-back portion 4A1, and the second sheet-attached terminal 45B, together with the first fold-back portion 4A1, fold back on the opposite side of the second transparent electrode sheet 21 relative to the first transparent electrode sheet 11. The second sheet-attached terminal 45B, which folds back together with the first fold-back portion 4A1, faces the second space and is face-to-face with the second transparent electrode terminal 23 through the first terminal opening 12.

[0081] Therefore, the shape of the second sheet-attached terminal 45B is such that the shape of the first sheet-attached terminal 45A is parallel to the guiding lines 4LA, 4LB, and 4LC. Furthermore, the second sheet-attached terminal 45B is separated from the first sheet-attached terminal 45A in the first direction D1, and its support surface of the insulating layer 41 is located on the opposite side of the first sheet-attached terminal 45A relative to the guiding lines 4LA, 4LB, and 4LC. Moreover, the second sheet-attached terminal 45B and the second transparent electrode terminal 23 are attached through a conductive adhesive.

[0082] Furthermore, the second sheet-attached terminal 45B faces the second space, while the second transparent electrode terminal 23 faces the first space. Also, as shown by the dotted line in FIG7, the first power supply terminal 42AT and the second power supply terminal 42BT located on the outer side of the dimming sheet 10 are located outside the dimming sheet 10, and like the second sheet-attached terminal 45B, they face the second space.

[0083] As shown in Figure 8, when the second sheet is connected to the terminal 45B and the second transparent electrode terminal 23, the second fold-back portion 4B1 folds back along the guiding lines 4LB and 4LC. The second fold-back portion 4B1, which folds back along the guiding lines 4LB and 4LC, is positioned on the opposite side of the first transparent electrode sheet 11 to the side of the second transparent electrode sheet 21 and is covered by the second terminal support portion 4B2.

[0084] In this way, the edge of the flexible wiring board 40, which is configured to bend in the induced straight lines 4LA, 4LB, and 4LC, is approximately aligned with the edge 10E of the dimming sheet 10. Furthermore, the flexible wiring board 40 is attached to the dimming sheet 10 in such a way that only the external terminal support portion 48 protrudes from the edge 10E of the dimming sheet 10, thereby manufacturing the dimming unit.

[0085] That is, as shown in Figure 9, the first fold-back portion 4A1 is folded back by sandwiching the first transparent electrode sheet 11 between the first fold-back portion 4A1 and the first terminal support portion 4A2. The second fold-back portion 4B1 is folded back by overlapping the second fold-back portion 4B1 and the second terminal support portion 4B2.

[0086] Based on the above implementation methods, the following effects can be obtained. (1) A support surface 41S is divided into two regions by a guide line 4LC. When a support surface 41S bends along the guide line 4LC, the support surface 41S in the first support piece 4A belonging to one region faces the first space divided by the dimming sheet 10. On the other hand, the support surface 41S in the second support piece 4B belonging to the other region faces the second space divided by the dimming sheet 10. Thus, the first sheet-attached terminal 45A and the second sheet-attached terminal 45B face opposite sides. As a result, the flexible wiring board 40 having two sheet-attached terminals 45A and 45B in one support surface 41S can be used in a double-sided configuration.

[0087] (2) Furthermore, viewed from a point on one of the bending lines 4LA, 4LB, and 4LC, the shape of the first sheet-attached terminal 45A is equal to the shape of the second sheet-attached terminal 45B. Also, when a support surface 41S bends along the guiding line 4LC, the shape of the first sheet-attached terminal 45A is equal to the shape that makes the shape of the second sheet-attached terminal 45B parallel to the guiding line 4LC. In this way, the sheet-attached terminals 45A and 45B can be attached one by one to two transparent electrode terminals 13 and 23 arranged along the guiding line 4LC and having the same shape.

[0088] (3) The plurality of bending-inducing recesses W1 and bending-inducing through holes W2 are located on a bending straight line passing through the guiding lines 4LA, 4LB, and 4LC. Therefore, the load on the flexible wiring board 40 when bending along the guiding lines 4LA, 4LB, and 4LC extending in the first direction D1 can be reduced, making it easier to utilize the above-mentioned double-sided flexible wiring board 40.

[0089] (4) The bending of the first sheet bonding terminal 45A and the second sheet bonding terminal 45B toward opposite sides is performed at the junction of the first front end 4AE of the first support piece 4A and the second base end 4BT of the second support piece 4B. In this way, the load required for bending can be reduced compared to bending the entire first support piece 4A or the entire second support piece 4B.

[0090] (5) The first foldback wiring 43A connected to the first thin-film connected terminal 45A extends toward the second thin-film connected terminal 45B. Therefore, it is easy to combine the first foldback wiring 43A connected to the first thin-film connected terminal 45A and the second foldback wiring 43B connected to the second thin-film connected terminal 45B. In this way, the flexible wiring board 40 can also give the wiring gathered in one place a unified feel as if it is pulled out from a dimming sheet 10, thereby improving the design of the dimming unit.

[0091] (6) Furthermore, the first terminal support portion 4A2 and the first fold-back portion 4A1 are distinguished by the guiding straight line 4LA defined by the bending guiding recess W1 and the bending guiding through hole W2. Therefore, the first terminal support portion 4A2 and the first fold-back portion 4A1 can be bent by bending the first sheet-attached terminal 45A and the second sheet-attached terminal 45B in opposite directions. In this way, the first terminal support portion 4A2 and the first fold-back portion 4A1 can be bent along the guiding straight line 4LA in an overlapping manner. Moreover, the first fold-back portion 4A1 can be prevented from extending beyond the edge of the dimming sheet 10 to which the first terminal support portion 4A2 is attached. As a result, the flexible wiring board 40 can also create a sense of unity between the dimming sheet 10 and the flexible wiring board 40, which can improve the design flexibility as a dimming unit.

[0092] (7) The second foldback wiring 43B connected to the second thin-film bonding terminal 45B extends toward the first thin-film bonding terminal 45A. Therefore, it is easy to combine the first foldback wiring 43A connected to the first thin-film bonding terminal 45A and the second foldback wiring 43B connected to the second thin-film bonding terminal 45B. In this way, the flexible wiring board 40 can also give the wiring gathered in one place a unified feel as if it is pulled out from a dimming sheet 10, thereby improving the design of the dimming unit.

[0093] (8) Furthermore, the guiding straight line 4LB defined by the bending guiding recess W1 and the bending guiding through hole W2 distinguishes the second terminal support portion 4B2 and the second fold-back portion 4B1. Therefore, the second terminal support portion 4B2 and the second fold-back portion 4B1 can be bent by bending the first sheet-attached terminal 45A and the second sheet-attached terminal 45B in opposite directions. In this way, the second terminal support portion 4B2 and the second fold-back portion 4B1 can be bent along the guiding straight line 4LB in an overlapping manner. Moreover, the second fold-back portion 4B1 can be prevented from extending beyond the edge of the dimming sheet 10 to which the second terminal support portion 4B2 is attached. As a result, the flexible wiring board 40 can also create a sense of unity between the dimming sheet 10 and the flexible wiring board 40, which can improve the design flexibility as a dimming unit.

[0094] (9) The external terminal support portion 48 extends from the first fold-back portion 4A1 relative to the guiding line 4LA towards the side opposite to the first fold-back portion 4A1. That is, the external terminal support portion 48 extends from the first fold-back portion 4A1 relative to the guiding line 4LA towards the same side as the first terminal support portion 4A2. Furthermore, when the first terminal support portion 4A2 and the first fold-back portion 4A1 bend at the guiding line 4LA, the external terminal support portion 48 extends from the first fold-back portion 4A1 relative to the guiding line 4LA towards the side opposite to the first terminal support portion 4A2. In this way, the external terminal support portion 48 can be pulled out relative to the guiding line 4LA towards the side opposite to the first terminal support portion 4A2, that is, towards the side opposite to the first transparent electrode terminal 13. Moreover, the flexible wiring board 40 can also give the wiring gathered in one place a unified feel as if it is pulled out from a dimming sheet 10, which can improve the design of the dimming unit.

[0095] (10) Since a flexible wiring board 40 that is not required to have a through hole can be used, the constraints of the bending part caused by the location of the through hole can also be reduced.

[0096] The above implementation can also be modified as shown below. [Vulnerable Ministry] The flexible wiring substrate 40 may also be configured such that at least a portion of the plurality of bending-inducing recesses W1 is omitted. The flexible wiring substrate 40 may also be configured such that at least a portion of the plurality of bending-inducing through holes W2 is omitted. In this case, the flexible wiring substrate 40 may also be configured such that at least a portion of the bending straight lines passing through the guiding straight lines 4LA, 4LB, and 4LC has an insulating layer 41 that is thinner than the portion outside the bending straight lines as a weak point.

[0097] • If the shape of the first thin-film connected terminal 45A is point-symmetrical with respect to a point on the bending line passing through the induced straight lines 4LA, 4LB, 4LC, and the shape of the second thin-film connected terminal 45B, then the flexible wiring substrate 40 can also be configured to omit the vulnerable part.

[0098] The portion of the first support piece 4A that connects with the second support piece 4B may also be located outside the first front end portion 4AE of the first support piece 4A in the first direction D1. For example, the portion of the first support piece 4A that connects with the second support piece 4B may also be located in the middle of the first support piece 4A in the first direction D1.

[0099] The portion of the second support piece B that connects with the first support piece 4A may also be located outside the base end 4BT of the second support piece 4B in the first direction D1. For example, the portion of the second support piece 4B that connects with the first support piece 4A may also be located in the middle of the second support piece 4B in the first direction D1.

[0100] [Bent straight line] • The first support piece 4A may also be configured such that there is no bend at the junction of the first fold-back portion 4A1 and the first terminal support portion 4A2. That is, the flexible wiring board 40 may also be configured to omit the induced straight line 4LA, or it may be configured to have induced straight lines 4LB and 4LC.

[0101] The second support piece 4B may also be configured such that there is no bend at the junction of the second fold-back portion 4B1 and the second terminal support portion 4B2. That is, the flexible wiring board 40 may also be configured to omit the induced straight line 4LB, or it may be configured to have induced straight lines 4LA and 4LC. Furthermore, the flexible wiring board 40 may also be configured to omit the induced straight line 4LA.

[0102] [Thin sheet connected to terminal] • The shape of the first sheet-attached terminal 45A can also be a shape other than being point-symmetrical with the shape of the second sheet-attached terminal 45B. In this case, the first sheet-attached terminal 45A only needs to be separated from the second sheet-attached terminal 45B in the first direction D1, and located on the opposite side of the second sheet-attached terminal 45B relative to the bending lines passing through the guiding lines 4LA, 4LB, and 4LC.

[0103] • The shape of the first terminal support 4A2 may also be a shape other than being point-symmetrical with the shape of the second terminal support 4B2. In this case, the first terminal support 4A2 may also be configured to be separated from the second terminal support 4B2 in the first direction D1 and located on the opposite side of the second terminal support 4B2 relative to the bending straight line passing through the guiding straight lines 4LA, 4LB, and 4LC.

[0104] The first sheet-attached terminal 45A is not limited to a single comb-shaped terminal; it may also be two or more comb-shaped terminals arranged in the first direction D1, or it may be two or more flat terminals. The second sheet-attached terminal 45B is not limited to a single comb-shaped terminal; it may also be two or more comb-shaped terminals arranged in the first direction D1, or it may be two or more flat terminals. The number of the first sheet-attached terminals 45A may also be different from the number of the second sheet-attached terminals 45B. In this case, the first sheet-attached terminals 45A may also be separated from the second sheet-attached terminals 45B in the first direction D1, and be located on the opposite side of the second sheet-attached terminals 45B relative to the bending lines passing through the guiding lines 4LA, 4LB, and 4LC.

[0105] The number of first foldback wiring 43A is not limited to one, but may be two or more. The number of first foldback wiring 43A may also be one of each of the comb-shaped terminals provided in the first sheet-connected terminal 45A. The number of second foldback wiring 43B is not limited to one, but may be two or more. The number of second foldback wiring 43B may also be one of each of the comb-shaped terminals provided in the second sheet-connected terminal 45B. The number of first foldback wiring 43A may also be a different number than the number of second foldback wiring 43B.

[0106] D1: Direction 1 10: Dimming film 10E: Edge 13: First transparent electrode terminal 15: First transparent electrode layer 15S: First electrode surface 23: Second transparent electrode terminal 23S: Second electrode surface 25: Second transparent electrode layer 31: Dimming Layer 40: Flexible wiring board 41: Insulation layer 41S: Support surface 4A: First Support Film 4A1: First Turnaround Section 4A2: Terminal 1 support section 4LA, 4LB, 4LC: Induced straight lines 4B: Second Support Piece 4B1: Second Turnaround Section 4B2: Second terminal support section 45A: The first thin sheet is connected to the terminal. 45B: The second thin sheet is connected to the terminal.

Claims

1. A flexible wiring board comprising: an insulating layer having a support surface extending in a first direction; a first sheet-attached terminal located on the support surface and extending in the first direction; and a second sheet-attached terminal located on the support surface and extending in the first direction, wherein the flexible wiring board is such that the shape of the first sheet-attached terminal is point-symmetrical with respect to a point on a bending line extending in the first direction to the shape of the second sheet-attached terminal; the insulating layer comprising: a first support sheet supporting the first sheet-attached terminal and extending in the first direction; and a second support sheet supporting the second sheet-attached terminal and extending in the first direction; wherein the portion of the first support sheet that contacts the second support sheet is at the front end of the first support sheet in the first direction; and the portion of the second support sheet that contacts the first support sheet is at the base end of the second support sheet in the first direction. The aforementioned flexible wiring board has a vulnerable portion located at the junction of the aforementioned front end and the aforementioned base end.

2. The flexible wiring board of claim 1 has a weak portion on the aforementioned bending line, the weak portion inducing the aforementioned flexible wiring board to bend on the aforementioned bending line.

3. A flexible wiring board comprising: an insulating layer having a support surface extending in a first direction; a first sheet-attached terminal located on the support surface; and a second sheet-attached terminal located on the support surface, wherein the flexible wiring board has a vulnerable portion along the bending line, the vulnerable portion inducing the flexible wiring board to bend along the bending line extending in the first direction; the first sheet-attached terminal is separated from the second sheet-attached terminal in the first direction and is located on the opposite side of the second sheet-attached terminal relative to the bending line; the insulating layer comprising: a first support piece supporting the first sheet-attached terminal and extending in the first direction; and a second support piece supporting the second sheet-attached terminal and extending in the first direction; wherein the portion of the first support piece that contacts the second support piece is at the front end of the first support piece in the first direction. The portion of the second support piece that is in contact with the first support piece is the base end of the second support piece in the first direction. The flexible wiring substrate has a vulnerable portion located at the junction of the front end and the base end.

4. A flexible wiring board as claimed in any one of claims 1 to 3, wherein the aforementioned insulating layer has a first support piece that supports the aforementioned first sheet connected terminal and extends in the aforementioned first direction, the aforementioned first support piece having: a first fold-back portion included in the aforementioned first direction at the front end of the aforementioned first support piece and extending in the aforementioned first direction; and a first terminal support portion, wherein the aforementioned first sheet connected terminal is located in the aforementioned first terminal support portion, the aforementioned first fold-back portion having a wiring located on the opposite side of the aforementioned first terminal support portion relative to the aforementioned bending line and extending from the aforementioned first sheet connected terminal toward the aforementioned second sheet connected terminal in the aforementioned first direction, the aforementioned flexible wiring board having a vulnerable portion located at the junction of the aforementioned first fold-back portion and the aforementioned first terminal support portion.

5. The flexible wiring substrate of claim 4, wherein the aforementioned insulating layer has a second support piece that supports the aforementioned second sheet connected terminal and extends in the aforementioned first direction, the aforementioned second support piece having: a second fold-back portion included at the base end of the aforementioned second support piece in the aforementioned first direction and extending in the aforementioned first direction; and a second terminal support portion, wherein the aforementioned second sheet connected terminal is located in the aforementioned second terminal support portion, the aforementioned second fold-back portion having a wiring located on the opposite side of the aforementioned second terminal support portion relative to the aforementioned bent straight line and extending from the aforementioned second sheet connected terminal toward the aforementioned first sheet connected terminal in the aforementioned first direction, the aforementioned flexible wiring substrate having the aforementioned vulnerable portion located at the junction of the aforementioned second fold-back portion and the aforementioned second terminal support portion.

6. The flexible wiring substrate of claim 5, wherein the portion of the first support sheet that is in contact with the second support sheet is at the front end of the first support sheet in the first direction, the portion of the second support sheet that is in contact with the first support sheet is at the base end of the second support sheet in the first direction, and the flexible wiring substrate has the aforementioned vulnerable portion located at the junction of the front end and the base end.

7. The flexible wiring board of claim 5, which has an external connection terminal, wherein the end of the aforementioned wiring extending from the aforementioned first sheet connected terminal and the end of the aforementioned wiring extending from the aforementioned second sheet connected terminal are located at the aforementioned external connection terminal, wherein the aforementioned external connection terminal is a portion of the aforementioned flexible wiring board that is connected to the aforementioned first fold-back portion, and extends from the aforementioned first fold-back portion toward the opposite side of the aforementioned bending straight line toward the aforementioned first fold-back portion.

8. A dimming unit comprising: a dimming sheet having an edge extending in a first direction; and a flexible wiring substrate attached to the edge, the dimming sheet comprising: a first transparent electrode layer having a first transparent electrode terminal on a first electrode surface; a second transparent electrode layer having a second transparent electrode terminal on a second electrode surface; and a dimming layer located between the first electrode surface and the second electrode surface such that the first transparent electrode terminal and the second transparent electrode terminal are exposed from the dimming layer, the first transparent electrode terminal and the second transparent electrode terminal constituting the edge and arranged along the first direction, the flexible wiring substrate comprising: an insulating layer having a support surface extending in the first direction; a first sheet-attached terminal attached to the first transparent electrode terminal, located on the support surface and extending in the first direction; and a second sheet-attached terminal attached to the second transparent electrode terminal, located on the support surface and extending in the first direction. The aforementioned support surface is bent along a bending straight line extending in the aforementioned first direction, and the shape of the aforementioned first sheet connected to the terminal is such that the shape of the aforementioned second sheet connected to the terminal is translated along the aforementioned bending straight line.

9. A dimming unit comprising: a dimming sheet having an edge extending in a first direction; and a flexible wiring substrate attached to the edge, the dimming sheet comprising: a first transparent electrode layer having a first transparent electrode terminal on a first electrode surface; a second transparent electrode layer having a second transparent electrode terminal on a second electrode surface; and a dimming layer located between the first electrode surface and the second electrode surface such that the first transparent electrode terminal and the second transparent electrode terminal are exposed from the dimming layer, the first transparent electrode terminal and the second transparent electrode terminal constituting the edge and arranged along the first direction, the flexible wiring substrate comprising: an insulating layer having a support surface extending in the first direction; a first sheet-attached terminal attached to the first transparent electrode terminal and located on the support surface; and a second sheet-attached terminal attached to the second transparent electrode terminal and located on the support surface, the support surface being bent in a straight line extending in the first direction. The first sheet-attached terminal is separated from the second sheet-attached terminal in the first direction, and the support surface is located on the opposite side of the second sheet-attached terminal relative to the bending line.

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