dimmer

Abstract

To provide a dimming device with which, when connecting an ITO and an FPC in the power supply connecting part of the dimming device using an ACF, it is possible to suppress the occurrence of cracks to the ITO as will be caused by conductive particles included in the ACF and prevent the drive voltage from lowering due to a rise of connection resistance between the FPC and a dimming sheet.SOLUTION: Provided is a dimming device comprising a dimming sheet which is capable of switching between an opaque state and a transparent state in accordance with an applied voltage, and a power supply connection unit for connecting the dimming sheet to an external power supply. The dimming sheet is composed by being sandwiched between a dimming layer and a transparent substrate in which a transparent electrode layer for applying a voltage to the dimming layer is formed. The power supply connection unit electrically connects the transparent electrode layer and an FPC via an ACF and has a mechanically bonded structure, with a conductive substance further laminated between the transparent electrode layer and the ACF, the conductive substance being formed from a material that is more flexible than the transparent electrode layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a light control device equipped with an optical element that controls the light transmission state by electrical control, and in particular to a light control device in which a positioning pattern for connecting a light control film and a flexible printed circuit board is formed. [Background technology]

[0002] Various ideas have been proposed for light control films that use liquid crystal panels that are attached to windows to control the transmission of external light. An example of a light control film is one that has a liquid crystal layer held between a pair of transparent electrodes made of ITO (indium tin oxide), and is configured so that the orientation of the liquid crystal molecules contained in the liquid crystal layer can be changed by applying a voltage to the transparent electrodes, allowing the film to switch between an opaque state (or a cloudy white state) that scatters incident light and a transparent state that transmits incident light (see, for example, Patent Document 1).

[0003] By fixing such light control films to a transparent substrate such as glass, they can be used not only in buildings but also in window glass for vehicles, exhibition windows, and partitions. They have also been proposed for use as a space separation device to separate private and public spaces, as well as a screen for projecting images.

[0004] Such light control films have a power supply connection part for connecting the transparent electrode layer to a power supply. As a low-cost and simple structure for the power supply connection part for supplying power from an external power supply, a structure has been adopted in which the transparent electrode ITO and an FPC (flexible printed circuit) are electrically connected using an ACF (conductive adhesive layer) and then mechanically bonded to draw out wiring (see Patent Document 2). The connection using an FPC and an ACF results in a planar bonding structure, which improves the durability of the bond against shaking and impacts during transportation and installation of the light control unit.

[0005] At this time, the power supply connection part of the light-controlling film and the FPC are aligned so that the connection terminals of the power supply connection part of the light-controlling film and the connection terminals of the FPC are not connected in a misaligned state.

[0006] Figure 1 shows a front view of a light control device. As shown in Figure 1, power connection portions 16A and 16B are provided at the ends of both sides of a light control film 11. A portion of the transparent electrode layer 13B on one side corresponding to the power connection portion 16A on the other side is cut and removed. The connection terminal of an FPC 17A is connected to the exposed transparent electrode layer 13A of the power connection portion 16A via an ACF 19A (see Figure 2). Because the light control film 11 does not have an alignment mark, the conventional alignment procedure for connecting the FPC 17A to the power connection portion 16A is as follows: As shown in Figure 4, in the vertical direction (Y direction), the light control film 11 is aligned using an edge 14 near the power connection portion 16A of the light control film 11 and alignment marks 15A made of Cu patterns formed on both sides of the FPC as alignment references. In the horizontal direction (X direction), the light control film 11 is aligned using an outer edge 5 or a cut line 6 on the other side where the transparent electrode layer on the other side has been removed and one edge 7 in the width direction of the FPC as alignment references. In a similar manner, the connection terminal of the FPC 17B is connected to the power supply connection portion 16B on the other surface.

[0007] However, since the alignment mark is not located in the area corresponding to the connection area on the light-control film 11, and the X-direction FPC alignment reference 7 and the light-control film 11 alignment reference (5 or 6) are formed at positions far apart, the positioning accuracy of the positioning camera is poor, and there was a problem that the transparent electrode layers 13A, 13B of the power connection parts 16A, 16B of the light-control film 11 and the terminal groups formed on the FPC 17A, 17B were not connected accurately. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-187775 [Patent Document 2] Patent No. 6439029 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in consideration of these problems, and an object of the present invention is to provide a light control device that uses an FPC and improves the positioning accuracy between the light control film and the FPC. [Means for solving the problem]

[0010] As a means for solving the above problems, the first aspect of the present invention is A light control device including a light control film that can be switched between an opaque state and a transparent state depending on an applied voltage, and a conductive part of an FPC connected to a power supply connection part formed at an end of the light control film, The light-control film is configured by sandwiching a light-control layer between a transparent substrate on which a transparent electrode layer for applying a voltage to the light-control layer is formed, the power supply connection portion has a structure in which the transparent electrode layer and the FPC are electrically connected to each other via an ACF and are mechanically bonded to each other; Vertical (Y-direction) alignment marks are provided on both ends of the FPC, and the alignment marks are aligned with the edge of the light control film near the power supply connection portion to position the connection between the light control film and the FPC in the vertical direction (Y-direction); The transparent electrode layer has a notch or a convex shape on the edge near the power connection portion, and one widthwise side edge of the notch or convex shape is used as a reference line, and one widthwise side edge of the FPC is abutted against the reference line, thereby positioning the connection between the light-control film and the FPC in the horizontal direction (X direction).This is a light-control device.

[0011] According to the present invention, positioning accuracy can be improved by forming a notch or convex shape with an alignment reference in the location on the light control film that corresponds to the connection area. In order to position the connection between the light control film and the FPC in the X direction, a notch or convex shape is provided in the transparent electrode layer near the power connection part. Therefore, there is no need to provide a separate alignment mark, and positioning can be achieved by abutting the references provided on each substrate, which has the effect of improving positioning accuracy.

[0012] In addition, a second aspect of the present invention is The notch or convex shape may be any shape, such as a straight line, a square, or a triangle, as long as it has a reference line that allows measurement of the distance in the X direction from one side in the width direction of the FPC. [Effects of the Invention]

[0013] In a light control device that uses an FPC, it is possible to provide a light control device that improves the positioning accuracy between the light control film and the FPC by providing a notch or a convex shape in the transparent electrode layer near the power connection part of the light control film. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a front view of a light control device according to an embodiment of the present invention; [Figure 2] 4 is a schematic cross-sectional view of a power supply connection portion formed on one surface of the light control device. FIG. [Figure 3] 10 is a schematic cross-sectional view of a power supply connection portion formed on the other surface of the light control device. FIG. [Figure 4] A diagram explaining the conventional method for positioning the connection between the light control film and the FPC. [Figure 5] 1A to 1C are diagrams illustrating a method for positioning the connection between the light control film and the FPC according to the present invention. [Figure 6] 5A and 5B are diagrams showing the shape of a notch according to the present invention. [Figure 7] 10A and 10B are diagrams showing the shape of a convex portion according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0015] An example of the structure of a light control device according to one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a light control device according to one embodiment of the present invention. As shown in FIG. 1, the light control device 10 is attached to a transparent plate 20 such as a window glass when used over a large area. The light control device 10 is mainly made of a flexible and thin material and is highly flexible. The support substrate is a transparent plate-like member made of glass, resin, or the like, and may be flat or curved. The transparent plate 20 may be a building material such as a partition or glass wall other than window glass, or may be a vehicle component such as an automobile window glass.

[0016] 1, the light control device 10 has a substantially rectangular shape, and the light control film 11, which accounts for the majority of the light control device 10, is sandwiched between a light control layer (liquid crystal layer) 12 and a pair of transparent electrode layers 13A and 13B that apply voltage to the light control layer 12 (see FIGS. 2 and 3). A power supply connection part 16A for supplying power from an external power supply 18A is connected to an end of the transparent electrode layer 13A, and a power supply connection part 16B for supplying power from an external power supply 18B is connected to an end of the transparent electrode layer 13B.

[0017] Each of the pair of transparent electrode layers 13A, 13B that apply a voltage to the light-controlling layer 12 is a transparent layer having electrical conductivity. Examples of materials that can be used to form the transparent electrode layers 13A, 13B include indium tin oxide (ITO), fluorine-doped tin oxide (FTO), tin oxide, zinc oxide, carbon nanotubes (CNT), and polymers containing poly(3,4-ethylenedioxythiophene) (PEDOT). The preferred thickness of the transparent electrode layers 13A, 13B is approximately 80 nm or more and 150 nm or less.

[0018] The power supply connectors 16A and 16B are located at the ends of the transparent electrode layers 13A and 13B along one side of the light control film. The side on which the power supply connectors 16A and 16B are located may be any side of the rectangle, and may be set depending on the arrangement of the transparent plate 20 and the drive circuit (not shown). The power supply connectors 16A and 16B may be located at a position that includes the center of the side, or may be located at a position that includes the end of the side, as shown in FIG. 1. The power supply connectors 16A and 16B are provided with lead wires (not shown), which extend outside the light control film 11 and are connected to the drive circuit.

[0019] In addition, a portion of the transparent electrode layer on the other surface (a portion of transparent electrode layer 13B and a portion of transparent electrode layer 13A, respectively) corresponding to the locations of transparent electrode layers 13A and 13B to which power supply connection portions 16A and 16B are connected is cut and removed, and power supply connection portions 16A and 16B are connected to the area exposed from dimming layer 12 and the transparent electrode layer on the other surface.

[0020] 2 and 3 , the transparent electrode layers 13A and 13B are attached to the transparent plate 20 via an adhesive layer 25. The transparent electrode layer 13A contacts one surface of the light-controlling layer 12, and the power supply connection portion 16A is connected to a region of the transparent electrode layer 13A that is exposed from the light-controlling layer 12 and the other transparent electrode layer 13B. The transparent electrode layer 13B contacts the other surface of the light-controlling layer 12. The power supply connection portion 16B is connected to a region of the transparent electrode layer 13B that is exposed from the light-controlling layer 12 and the other transparent electrode layer 13A, and faces the transparent plate 20.

[0021] The power supply connectors 16A and 16B include ACFs 19A and 19B, which are conductive adhesive layers bonded to the transparent electrode layers 13A and 13B, and flexible printed circuit boards FPCs 17A and 17B bonded by the ACFs 19A and 19B. The power supply connectors 16A and 16B further include lead wires connected to the FPCs 17A and 17B. The lead wires are connected to the power supply. The light control film 11 is connected to a drive circuit that converts voltage into a drive voltage, and the drive voltage is applied to the transparent electrode layers 13A and 13B through the power supply connectors 16A and 16B. Therefore, by relatively aligning the power supply connectors 16A and 16B with the terminals provided on the FPCs 17A and 17B, the light control film 11 and the FPCs 17A and 17B are electrically connected to each other.

[0022] 5 shows rectangular cutouts 30 formed on both sides of the position where the FPC 17A is connected to the corresponding portion of the power connection portion 16A in the light control film 11 according to the present invention. One widthwise side 31 of this cutout 30 and one widthwise side 7 of the FPC 17A are used as alignment references in the X direction, and Y-direction alignment marks 15A formed at both ends of the FPC and the edge 4 near the power connection portion are used as alignment references in the Y direction to position the connection between the light control film and the FPC 17A. The light control film 11 and the FPC 17B on the other side are also connected using a similar positioning method. The rectangular cutouts 30 may be formed only on one side of the connection position.

[0023] In this way, the notches 30 are formed close to both sides of the position where the light-control film 11 and the FPCs 17A and 17B are connected. By using one widthwise side edge 31 of the notch 30 and one widthwise side edge 7 of the FPC 17A as the alignment reference in the X direction, it becomes possible to perform accurate positioning in the X direction using a positioning camera.

[0024] Furthermore, the shape of the notch 30 according to the present invention can be a triangle or a straight line, in addition to a square, as shown in Fig. 6, as long as it has a reference line in the X direction. For the same reason, a convex shape other than a notch can also be used. Examples of convex shapes that can be used include a square convex shape, a triangular convex shape, and an FPC portion convex shape, as shown in Fig. 7.

[0025] Positioning using the notched or convex positioning pattern 30 is performed, for example, by installing a CCD camera and an illumination light source, while observing the vicinity of the positioning pattern 30 in a magnified manner. The illumination light source illuminates the vicinity of the positioning pattern 30, and an image of the vicinity of the positioning pattern 30 captured by the CCD camera is displayed on a monitor or the like. While viewing this monitor, alignment is performed by moving the FPCs 17A and 17B so that their reference lines abut, and the light control film 11 and the FPCs 17A and 17B are aligned and then bonded together via the ACFs 19A and 19B. This allows the light control film 11 and the FPCs 17A and 17B to be connected with high precision.

[0026] As described above, by simply aligning one widthwise side 7 of FPCs 17A, 17B as a reference line in the X direction and aligning the reference line with one widthwise side of the notched or convex shape provided in transparent electrode layers 13A, 13B near power connection portions 16A, 16B, and placing FPCs 17A, 17B in contact with each other, terminal portions of FPCs 17A, 17B automatically align with terminal portions of power connection portions 16A, 16B, and therefore, positioning can be performed accurately in a short time by optically aligning them using a CCD camera. In other words, by using positioning patterns 30 of notched or convex shapes provided in transparent electrode layers 13A, 13B as a positioning jig, positioning of FPCs 17A, 17B can be performed inexpensively and easily.

[0027] Therefore, according to the present invention, it is possible to provide a light control device in which the light control film 11 and the FPCs 17A and 17B can be connected with high precision in both the horizontal and vertical directions. [Explanation of symbols]

[0028] 4. Edge of light control film 5. Light control film side 6 Transparent electrode layer cut line 7...FPC side 10. Light control device 11. Light-controlling film 12. Photochromic layer 13A, 13B...Transparent electrode layer 15 Alignment mark 16A, 16B... Power supply connection 17A, 17B...FPC 18A, 18B...External power supply 19A, 19B...ACF 20...Transparent plate 25...Adhesive layer 30. Notch or convex shape (positioning pattern)

Claims

1. A light control device including a light control film that can be switched between an opaque state and a transparent state depending on an applied voltage, and a conductive portion of an FPC connected to a power supply connection portion formed at an end of the light control film, The light-control film is configured by sandwiching a light-control layer between a transparent substrate on which a transparent electrode layer for applying a voltage to the light-control layer is formed, the power supply connection portion has a structure in which the transparent electrode layer and the FPC are electrically connected to each other via an ACF and are mechanically bonded to each other; Alignment marks in the vertical direction (Y direction) are provided on both ends of the FPC, and the alignment marks are aligned with the edge of the light control film near the power supply connection portion to position the connection between the light control film and the FPC in the vertical direction (Y direction); A light-adjusting device characterized in that the transparent electrode layer has a notch or a convex shape on the edge near the power supply connection portion, one side edge in the width direction of the notch or convex shape is used as a reference line, and one side edge in the width direction of the FPC is abutted against the reference line, thereby positioning the connection between the light-adjusting film and the FPC in the horizontal direction (X direction).

2. The light control device according to claim 1 , wherein the notch or the convex shape is any one of a linear shape, a rectangular shape, and a triangular shape.

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