CN111213116A

CN111213116A - Capacitive sensor

Info

Publication number: CN111213116A
Application number: CN201980005129.2A
Authority: CN
Inventors: 本松良文; 小笠原洋
Original assignee: Polymatech Japan Co Ltd
Current assignee: Sekisui Polymatech Co Ltd
Priority date: 2018-01-16
Filing date: 2019-01-11
Publication date: 2020-05-29
Anticipated expiration: 2039-01-11
Also published as: CN111213116B; JP6650161B2; JPWO2019142748A1; WO2019142748A1

Abstract

A planar resin film is used to obtain a capacitive sensor having a curved surface. A capacitance sensor 1 includes an electrode film 20, the electrode film 20 includes an insulating base film 30 attached to a sensor holder 10 and an electrode layer 40 provided on the base film 30, the electrode film 20 generates a change in capacitance in the electrode layer 40, the base film 30 includes one or more bridge-like extensions 30a, the bridge-like extensions 30a include a bridge portion 32 and a plurality of island portions 31, the island portions 31 are laminated along a curved surface of a curved surface portion 10a of the sensor holder 10, the bridge portion 32 connects the plurality of island portions 31 to each other along the curved surface portion 10a, and the electrode layer 40 includes an island electrode layer 30a provided on the island portions 31 and a bridge electrode layer 40b provided on the bridge portion 32.

Description

Capacitive sensor

Technical Field

The present invention relates to a capacitance sensor provided with a detection area for detecting a change in capacitance on a curved surface of a tangible object.

Background

In a conventional capacitive sensor used as a touch panel, a resin film which is hard and hardly stretched is often used, and the shape thereof also has a planar shape. In recent years, there has been an increasing demand for touch panels having three-dimensional shapes such as a spherical surface, a curved surface, and a torus (circular ring shape). However, a curved surface shape having a gaussian curvature other than 0, such as a horn shape (gaussian curvature <0) or a spherical shape (gaussian curvature >0), cannot be developed as a plane. Therefore, when a shape having a gaussian curvature other than 0 is to be formed from a plane, distortion occurs in some place. Therefore, when a planar touch panel is formed into a curved surface shape, there is a problem that uneven expansion and contraction portions, gaps, breakage, wrinkles, twisting, overlapping of corners, and the like are likely to occur.

In order to change the planar shape to a three-dimensional shape, there is a method of obtaining a final three-dimensional shape by using a vacuum molding technique involving stretching or shrinking in the touch panel. For example, the technique described in japanese patent laid-open No. 2017-102511 (patent document 1) belongs to the above-mentioned method.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-102511

Disclosure of Invention

Problems to be solved by the invention

However, the above-described conventional method has a problem that the cost is increased by using a mold and a problem that it is difficult to obtain the target molding accuracy due to the influence of heat.

Accordingly, an object of the present invention is to provide a capacitance sensor that can use a planar resin film as a raw material and can form a detection region in a curved surface shape.

Means for solving the problems

In order to achieve the above object, the present invention is configured as follows. That is, the present invention is a capacitive sensor including an electrode film having an insulating base film attached to a sensor holder and an electrode layer provided on the base film, wherein the base film has one or more bridge-like extensions, the bridge-like extensions have a bridge portion and a plurality of island portions, the island portions are laminated along a curved surface shape of a curved surface portion of the sensor holder, the bridge portion connects the plurality of island portions to each other along the curved surface portion, and the electrode layer has an island portion electrode layer provided on the island portion and a bridge portion electrode layer provided on the bridge portion.

The capacitive sensor according to the present invention includes one or more bridge-shaped extensions each having a plurality of island portions connected to each other by a bridge portion, and the bridge-shaped extensions each include the island electrode layer and the bridge electrode layer. In the island bridge-like elongated portion, an appropriate gap can be formed between the island portions by combining the island portions and the bridge portions. The island portions having the island electrode layers are stacked along the curved surface of the sensor holder, and the bridge portions having the bridge electrode layers, which connect the discrete island portions, are curved along the curved surface of the sensor holder. This allows the electrode film to be attached along the curved surface portion of the sensor holder without generating wrinkles or floating as much as possible. Therefore, a capacitance sensor (touch sensor) having a detection area with a curved surface can be provided on the sensor holder. Also, the electrode layer can be provided on a planar base film as a material, and thus the electrode film can be easily manufactured.

One island bridge-like extension of the base film may be configured to include any of the following forms: an island part and a bridge part are alternately arranged in series; a plurality of bridge parts branching from the island part and arranged in parallel; and a composite form in which these forms are combined. The island bridge-like extensions may be linear extending in one direction, or may be elongated in a plurality of directions.

According to the structure in which the island portions and the bridge portions are alternately arranged in series, a plurality of island portions can be provided by sandwiching the bridge portions. Therefore, even if a relatively large island portion cannot be formed in the detection region, a plurality of small island portions can be provided, and a wide detection region can be filled with the island portions.

According to the structure in which the plurality of bridge portions are branched from the island portion and arranged in parallel, it is possible to obtain a wider variety of combinations of the island portion and the bridge portion than a configuration in which the island portion and the bridge portions are alternately arranged in series, and it is possible to easily follow the island portion even for a wide variety of curved surfaces.

The electrode film may have a terminal portion for electrically connecting the electrode layer to an external device. According to the present invention, it is possible to output a change in capacitance in the capacitance sensor in which the detection region is a curved surface to an external device via the terminal portion. In addition, the terminal portion does not need to be provided to the sensor holder, and the conductive portions can be formed on the base film in a concentrated manner. Therefore, the electrode layer and the conductive wiring are easily formed.

The bridge portion may be configured in a thin band shape having a width smaller than that of the island portion. According to the present invention, since the width of the bridge portion is a narrow band shape narrower than the width of the island portion, the mutual constraint force in the portion where the island portion and the bridge portion are connected can be reduced. Therefore, the curved surface following property to the sensor holder can be improved over the entire length of the bridge portion, and the curved surface following property to the sensor holder can also be improved by the island portion itself. Therefore, the appropriate (Fit) feeling of the curved surface shape of the entire electrode film with respect to the sensor holder can be improved.

The plurality of islands may be configured to include a plurality of types of different sizes. According to the present invention, the island portions having different sizes can be densely arranged so that at least a part of the island portions is present in a range in which a contact body such as a finger in the detection area comes into contact with the island portions. Therefore, the following can be reduced as much as possible: the entire surface of the curved surface portion of the sensor holder cannot be covered with the electrode film, and a sea portion not covered with the electrode film is generated. Further, by arranging a plurality of kinds of islands having different sizes in combination, it is possible to suppress the occurrence of wrinkles, floating, and twisting when the electrode film is attached to the sensor holder.

The electrode layer may be formed of a conductive film layer and a metal wiring, and the metal wiring may be provided so as to be continuous from the terminal portion and border an outer edge of the island electrode layer. According to the present invention, the variation due to the length of the arrangement distance is small in the island portion close to the terminal portion and the island portion far from the terminal portion, and the change in capacitance can be detected by the metal wiring formed by bordering the electrode layer of the island portion.

In the present invention, a plurality of bridge portions may be connected to one island portion. According to the present invention, a branching structure in which a plurality of bridge portions branch from one island portion and each bridge portion is connected to a different island portion can be formed. Therefore, the space (sea portion) in which the electrode films are not laminated can be reduced as much as possible in the curved surface portion of the sensor holder. This allows the island and the island electrode layer to be disposed at each corner of the detection region provided in the curved surface portion.

The island can be circular in shape. According to the present invention, since there is no corner portion that is easily peeled from the curved molded body on the island portion, the occurrence of peeling of the electrode film can be suppressed. Further, since a gap can be inevitably generated between the adjacent island portions, when the electrode film is laminated on the curved surface portion of the sensor holder having a gaussian curvature different from 0, the generation of wrinkles, floating, and distortion can be suppressed.

The curved surface of the curved surface portion of the sensor holder may have a curved surface shape having a gaussian curvature different from 0, and the island portion may have a shape arranged along the curved surface shape. According to the present invention, the shape of the island portion has a shape that can be arranged along a curved surface shape having a gaussian curvature different from 0, and therefore, the capacitance sensor can be provided with excellent design. The gaussian curvature is defined as the product of the principal curvatures K1 and K2 (K ═ K1 × K2) of a surface at an arbitrary point on the surface, and when the gaussian curvature K is less than 0, the surface has a curved shape such as a pommel horse, when the gaussian curvature K is 0, the surface has a cylindrical shape without concavities and convexities on the curved shape, and when the gaussian curvature K >0, the surface has a spherical shape.

The curved surface of the curved surface portion of the sensor holder may have a curved surface shape having a positive gaussian curvature, and the island portion may have a shape arranged along the curved surface shape. According to the present invention, even if the curved surface shape of the sensor holder is a spherical surface shape, the capacitance sensor can be made excellent in design.

In the present invention, a ratio of a maximum width of each of the largest island portion and the smallest island portion among the island portions may be 3: 1-10: 1. according to the present invention, the island portion can be provided as large as possible on the curved surface portion of the sensor holder, and the island portion can be arranged relatively without a gap.

The present invention may be configured to have a plurality of the island-bridge-like extensions, and to form detection regions of different capacitances for each of the island-bridge-like extensions. According to the present invention, not only a change in capacitance of one detection region can be detected, but also position detection can be performed in accordance with the arrangement of each of the plurality of island-bridge-like extensions. Further, the more detection regions of the island-bridge-like extensions are provided, the more accurate position detection can be performed.

The present invention may further include the sensor holder that attaches the electrode film to the curved surface portion. According to the present invention, a capacitance sensor having a detection region with a curved surface shape can be obtained by mounting an electrode film on a curved surface portion.

The present invention may be configured to include a plurality of island portions adjacent to any one of the island portions and larger than the one island portion, and a bridge portion connecting the any one of the small island portions and the plurality of large island portions extends from the one small island portion. According to the present invention, even a small island portion is supported by a plurality of large island portions via a plurality of bridge portions, and therefore, the base film can be stably held as a part of the base film, and the base film can be easily handled.

The sensor holder may be formed in a hemispherical shape. Since the sensor holder has a hemispherical shape, the curvature is constant, and the electrode films are easily laminated. In addition, a capacitive sensor having excellent design can be obtained.

The electrode film may be formed of a flat base film, with the overall shape of the electrode film being substantially fan-shaped. According to the present invention, when the sensor holder is laminated on the curved surface portion having a gaussian curvature of not 0, the films do not overlap each other, and wrinkles, floating, and distortion can be prevented from occurring at the time of lamination.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the capacitance sensor of the present invention, the detection region along the curved surface shape can be easily provided on the curved surface portion of the sensor holder.

Drawings

Fig. 1 is a schematic plan view of a capacitive sensor according to a first embodiment.

Fig. 2 is a sectional view taken along line II-II of fig. 1.

Fig. 3 is an explanatory view explaining a surface shape of the detection region and a laminated structure thereof, 3A in fig. 3 shows a partially enlarged plan view of the detection region, and 3B in fig. 3 shows a cross-sectional view taken along line IIIB-IIIB of 3A in fig. 3.

Fig. 4 is an explanatory view for explaining the surface shape of the detection region and the layered structure thereof, 4A in fig. 4 shows a partially enlarged plan view of a portion different from 3A in fig. 3, and 4B in fig. 4 shows a cross-sectional view taken along line IVB-IVB of 4A in fig. 4.

Fig. 5 is an explanatory diagram corresponding to a schematic top view of fig. 1 for explaining the detection region.

Fig. 6 is a schematic plan view of the capacitive sensor according to the second embodiment.

Fig. 7 is a schematic plan view of the capacitive sensor according to the third embodiment.

Fig. 8 is an explanatory diagram showing a laminated structure of a capacitance sensor according to a modification of the embodiment.

Fig. 9 is a schematic plan view corresponding to fig. 1 of a capacitive sensor according to a first modification of the embodiment.

Fig. 10 is a schematic plan view corresponding to fig. 1 of a capacitive sensor according to a second modification of the embodiment.

Fig. 11 is a schematic perspective view of a capacitive sensor according to a third modification of the embodiment.

Fig. 12 is a schematic perspective view of a capacitive sensor according to a fourth modification of the embodiment.

Detailed Description

The capacitive sensor of the present invention will be described in detail based on embodiments. Repetitive description of parts, materials, manufacturing methods, operational effects, functions, and the like that are repeated in the respective embodiments will be omitted.

First embodiment (FIGS. 1 to 5)

As shown in fig. 1 to 5, a capacitance sensor 1 according to a first embodiment includes an electrically insulating curved molded body 10 and an electrode film 20 laminated on the curved molded body 10. The electrode film 20 has a base film 30 and an electrode layer 40 formed on the base film 30. The curved molded body 10 constitutes the "sensor holder" of the present invention. In the present embodiment, a resist layer 50 and a surface protection layer 60 are formed on the surface of the electrode film 20. In fig. 1 and 2, enlarged partial views are shown as R1 to R4.

The curved molded body 10 is a portion to be attached to which the electrode film 20 having the electrode layer 40 is attached. The curved molded body 10 may be formed into a molded body having various curved surfaces according to functions or applications. The material forming the curved molded body 10 is an electrically insulating material, and preferably a resin from the viewpoint of moldability. Specifically, various resins such as acrylic resin, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyethylene terephthalate, methacrylic resin, polyvinyl alcohol, polycarbonate, fluororesin, phenol resin, polyurethane, polyester, and epoxy resin can be used.

The surface of the curved molded body 10 may be a curved surface (a "curved surface portion" in the present invention) 10a or a cylindrical shape having a gaussian curvature of 0. However, with such a curved surface 10a, it is hardly difficult to stack planar electrode films. The electrode film 20 is advantageous when applied to the curved molded body 10 having a gaussian curvature other than 0. Examples of the shape having a gaussian curvature other than 0 include a hemispherical shape, a dome shape, a spherical shape, and an elliptical shape. The curved molded body 10 having the entire surface formed by the curved surface 10a having the gaussian curvature of not 0 is not limited, and the curved molded body 10 may be a curved molded body 10 having the curved surface 10a partially on a part of the surface, but the surface on which the electrode layer 40 is provided is the curved surface 10 a. The curved surface shape is preferably a hemispherical shape or a spherical shape having a constant curvature from the viewpoint of laminating the electrode film 20. As an example of the curved molded body 10, as shown in fig. 1, 2 and 5, a dome-shaped curved molded body 10 made of hard acrylic resin having a bottom surface with a diameter of 100mm, a height of 25mm and a spherical radius of 62.5mm may be used.

The base film 30 constituting the electrode film 20 is formed in a shape of a plurality of islands 31, a plurality of bridge portions 32, and terminal portions 33, and the bridge portions 32 are narrower than the islands 31 and connect the islands 31 to each other. The base film 30 is formed by cutting a sheet of flat resin film as a material, and punching out the other portions so as to retain the shapes.

The island portion 31 includes a plurality of kinds having different sizes. Each island 31 is formed in a size that can be stacked along the curved surface shape of the curved molded body 10. In other words, the curved molded body 10 is formed to have a size that does not cause wrinkles, floating, or twisting when attached to a curved surface. When the curvature of the curved molded body 10 is small, a large area can be molded. However, when the curvature of the curved molded body 10 is large, if the curved molded body is not molded in a small narrow area, wrinkles, floating, and twisting are likely to occur. The size of the island 31 is affected by the curvature of the curved molded article 10, but the maximum width is usually about 5mm to 30 mm. The shape of the island 31 may be a perfect circle, an ellipse, a polygon, or the like, but is preferably a shape that is easily followed along the curved surface shape of the curved molded body 10, and more preferably a circular shape.

Further, when comparing the sizes of the largest island 31 and the smallest island 31, it is preferable that the ratio of the maximum width of the largest island 31 to the maximum width of the smallest island 31 is 3: 1-10: 1. when the island 31 is disposed on a curved surface, if the maximum width of the smallest island 31 is extremely small relative to the maximum width of the largest island 31, the number of the small islands 31 increases. As a result, the electrode layer 40 is provided on all of the small island portions 31, or the bridge portion 32 having a width smaller than that of the island portion 31 is provided, which complicates the wiring structure. A complicated wiring structure is not preferable in view of mass production. Further, if the island portion 31 is too small, the contact area with a contact body such as a finger that performs touch input may be small, and detection accuracy may be degraded.

As an example of the island 31, the island 31 having a size as shown below can be exemplified. In the case where the island 31 having a size capable of being stuck to the curved molded body (dome shape having a bottom surface of 100mm in diameter, a height of 25mm and a spherical surface of 62.5mm in radius; made of hard acrylic resin) 10 is molded by a PET film having a thickness of 100 μm, the largest circular island 31 can be made to have a diameter of 14.5mm, and the smallest circular island 31 can be made to have a diameter of 4 mm.

The respective island portions 31 are connected by bridge portions 32. The bridge portion 32 is formed to be narrower than the maximum width of the island portion 31, and in addition to connecting the island portions 31 to each other, in the case where the terminal portion 33 is formed on the base film 30 as in the present embodiment, the terminal portion 33 is also connected to the island portion 31 via the bridge portion 32.

Any one of the island portions 31 is generally connected to two adjacent island portions 31 by two bridge portions 32. This is because the island electrode layer 40a of any one island 31 must be electrically connected to the terminal 33 even if another island 31 is interposed therebetween. That is, focusing on a certain island 31, there are many cases where: the bridge portion 32 is connected to the island portion 31 adjacent to the terminal portion 33, and the bridge portion 32 is connected to the island portion 31 adjacent to the island portion 31 on the side away from the terminal portion 33. Since the island portion 31 of the end no longer has the island portion 31 farther from the terminal portion 33, the island portion 31 of the end may be connected to the adjacent island portion 31 only by one bridge portion 32.

Therefore, the island portions 31 and the bridge portions 32 are alternately connected from the terminal portions 33, and the island portions 31 and the bridge portions 32, which are flat continuous bodies, are attached to the curved surface 10a of the curved molded body 10 without wrinkles or floating, so that the electrode film 20 can be attached to the curved surface 10a even in a large detection region. Therefore, the following disadvantages can be avoided: in the process of attaching the electrode film 20 to the surface 10a of the curved molded body 10, wrinkles and distortion become serious, and the electrode film 20 cannot be attached to a large detection region.

On the other hand, there are few cases where the three bridge portions 32 are connected to the three adjacent island portions 31, respectively. This is because the degree of freedom is reduced by being planarly constrained by being connected to the plurality of bridge portions 32, and it becomes difficult to follow the curved surface of the curved molded body 10. From the viewpoint of adhesion to the surface of the curved molded body 10, this is because, ideally, if conductive connection with the terminal portion 33 is neglected, it is preferable that the island portion 31 is isolated and not connected with the bridge portion 32. However, three bridge portions 32 connected to each of the three island portions 31 adjacent to any one of the island portions 31 may be provided. It is not excluded that one island portion 31 is connected by two or more bridge portions 32.

The reason why the island portion 31 has a plurality of (a plurality of) sizes is that if the surface of the curved molded body 10 is covered with the circular island portion 31 having a large area, the sea portion 11 where the base film 30 does not exist is generated between the island portions 31. Since the electrode layer 40 is not formed in the sea portion 11 and the capacitance change is not detected, the area of the sea portion 11 needs to be reduced. As a method for reducing the area of the sea portion 11, the portion can be filled with a small island portion 31.

The base film 30 is formed of an electrically insulating film, and examples of the material include polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, Polycarbonate (PC) resin, polymethyl methacrylate (PMMA) resin, polypropylene (PP) resin, Polyurethane (PU) resin, Polyamide (PA) resin, polyether sulfone (PES) resin, polyether ether ketone (PEEK) resin, triacetyl cellulose (TAC) resin, Polyimide (PI) resin, cycloolefin polymer (COP), and the like. In the capacitance sensor 1 requiring transparency, a resin film having transparency is preferably used as the base film 30.

The thickness of the base film 30 is not particularly limited, but is preferably 10 μm to 250 μm. When the thickness is smaller than 10 μm, the strength may be damaged. If the thickness exceeds 250 μm, flexibility when the laminate is laminated on the curved molded article 10 is impaired, and handling properties such as peeling may occur. Further, from the viewpoint of strength and handling property, the thickness is more preferably 50 μm to 150 μm. The surface of the base film 30 may be subjected to a surface treatment, or a primer layer or a surface protective layer for improving adhesion to a conductive polymer, an overcoat layer for the purpose of antistatic, and the like may be provided.

The electrode layer 40 stacked on the base film 30 includes an island electrode layer 40a provided on the island 31 and a bridge electrode layer 40b provided on the bridge 32. The electrode layer 40 of the present embodiment includes a conductive film layer 41 and a metal wiring 42. The conductive film layer 41 is preferably formed on the entire surface of the island portion 31 and the bridge portion 32 connecting the island portions 31 to each other, but is preferably formed at least at a portion other than the outer edge of the island portion 31 and the bridge portion 32 connecting the

island portions

31, 31 to each other. The conductive film layer 41 is not formed on the terminal portion 33 and the bridge portion 32 connecting the island portion 31 and the terminal portion 33. This is because these portions are connected to the terminal portion 33, and are portions in which the capacitance change is not normally detected. In addition, these portions are dense portions of wirings having different detection methods, and it is difficult to distinguish the wirings in the conductive film layer 41.

The conductive film layer 41 is preferably made of conductive ink containing a conductive polymer or the like. This is because the conductive polymer hardly loses conductivity when the base film 30 expands and contracts, and the capacitance sensor 1 having high transparency can be obtained. Further, it is also preferable that a liquid coating liquid be formed by printing, and that the capacitance sensor 1 be obtained at a lower cost than ITO or the like. Examples of the transparent conductive polymer include polyparaphenylene, polyacetylene, PEDOT-PSS (poly 3, 4-ethylenedioxythiophene-polystyrenesulfonic acid), and the like. In the case where transparency is not required, the conductive film layer 41 may be formed by a conductive ink such as carbon paste. The carbon paste is preferable from the viewpoint of being able to obtain the capacitance sensor 1 at a lower cost than the conductive polymer and from the viewpoint of being excellent in weather resistance.

The layer thickness of the conductive film layer 41 is preferably 0.04 to 1.0. mu.m, more preferably 0.06 to 0.4. mu.m. If the layer thickness is less than 0.04 μm, the resistance value of the capacitance sensor 1 may become high, and if the layer thickness exceeds 1.0 μm, the transparency may become low. Further, the thickness of the conductive film layer 41 may be measured by forming the conductive film layer 41 on the base film 30 and using an Atomic Force Microscope (AFM) or the like.

As shown in the partially enlarged view of fig. 1, in the present embodiment, in the island portion 31, the metal wiring 42 is formed in a linear shape so as to border the outer edge of the island portion 31, or in a linear shape so as to border the outer edge in the vicinity of the outer edge slightly inward from the outer edge. The metal wiring 42 provided on each of the

island portions

31 and 31 connected to the bridge portion 32 is formed in a linear shape near the center of the bridge portion 32 so as to be connected to the bridge portion 32. These linear metal wires 42 also serve as wires for connecting the island portions 31 to each other. In addition, unlike the formation of the electrode layer 40, the metal wiring 42 is a lead wire (wiring) extending from the electrode layer 40 and electrically connecting the electrode layer 40 and the terminal portion 33. Further, the metal wiring 42 also contributes to transmission of a detection signal of a capacitance change to a control unit of an external device provided in the terminal portion 33 and connected to the capacitance sensor 1. Fig. 3 and 4 show an enlarged plan view and a cross-sectional view of a part of the detection region of the capacitance sensor 1, with respect to the layer structure of the electrode film 20 adhered to the surface of the curved molded body 10. Since the cross-sectional views of fig. 3 and 4 are enlarged cross-sectional views of a small area, the surface is illustrated as a substantially flat view.

The metal wiring 42 is preferably formed of a conductive paste containing a highly conductive metal such as copper, aluminum, silver, or an alloy containing these metals, and among these, a silver wiring formed of a silver paste having a high conductivity and being less oxidized than copper is preferred.

The thickness of the metal wiring 42 is preferably 1.0 to 20 μm. If the thickness is less than 1.0 μm, the resistance of the wiring tends to increase, which may cause noise. On the other hand, if it exceeds 20 μm, the difference in height level between the wiring and the portion other than the wiring becomes large, and when a resist layer 50 described later is provided on the electrode layer 40, air bubbles may be mixed in.

Since the resistance value is reduced by providing the metal wiring 42 as compared with the case where only the conductive film layer 41 is provided, even in the case where the conductive film layer is touched with a finger or the like at a position away from the terminal portion 33, the capacitance change can be detected similarly to the case where the conductive film layer is touched with a finger or the like at a position close to the terminal portion 33, and variation in detection accuracy can be reduced.

In the present embodiment, all of the island portions 31 are connected to other island portions 31 via the bridge portion 32, and the electrode film 20 is formed from one base film 30. In addition, the electrode layer 40 formed on the island portion 31 and the bridge portion 32 is electrically connected to the terminal portion 33, but its path is formed by 5 systems insulated from each other, the 5 systems including: an island electrode layer 40a and a bridge electrode layer 40b connecting them to the terminal portion 33 are provided on one island portion 31 on top of the base film 30, and electrode layers 40 (an island electrode layer 40a and a bridge electrode layer 40b) are provided on 4 island-

like extensions

30a, 30b, 30c, and 30d, respectively (fig. 5). In other words, the electrode layer 40 formed on any one of the island portions 31 belongs to any one of the 5 systems.

In the capacitance sensor 1, since the hemispherical surface of the curved molded body 10 is covered with the electrode film 20 and the electrode layer 40 is disposed in this region, the hemispherical surface serves as a detection region P in which a capacitance change should be detected, and when a contact body such as a finger that performs a touch input comes into contact in this range, the capacitance change can be detected. In the present embodiment, as shown in fig. 5, the detection region P is divided into 5 regions a to E, and a change in capacitance can be detected by the electrode layer 40 disposed in each region. For example, if a certain portion in the area a in fig. 5 is touched, it can be detected that the switch in the area a is ON (ON), and if a certain portion in the area B is touched, it can be detected that the switch in the area B is ON (ON). Thus, 5 pieces of position information can be obtained. Although the boundaries of the regions a to E are not clearly shown in fig. 1, for convenience of explanation, the boundaries of the regions a to E are shown in bold in fig. 5, the terminal portion 33 is omitted, and the island-bridge-

like extensions

30a, 30b, 30c, and 30d are shown by broken lines.

Focusing on the region a, all of the island electrode layers 40a and bridge electrode layers 40b formed on the island 31 and bridge 32 of the island-bridge-like extensions 30a disposed in the region a are electrically connected to each other, and are connected to one wire reaching the terminal portion 33. Similarly, in the other regions, all of the island portions 31 and the electrode layers 40 formed on the bridge portion 32 disposed in one region are electrically connected to each other, and are connected to one wiring reaching the terminal portion 33. Thus, there are 5 wires in the terminal portion 33, and they do not contact each other (see fig. 1).

The resist layer 50 is an insulating coating film provided to prevent conduction of the plurality of electrode layers 40 and to protect the electrode layers 40 from ultraviolet rays, scratches, and the like. It is also suitable for use in preventing the metal wiring 42 made of a conductive paste containing silver paste or conductive metal from being vulcanized. Examples of the resin to be the resist layer 50 include acrylic, urethane, epoxy, polyolefin, and other resins, and when transparency is required, a resin having transparency is exemplified. The thickness of the resist layer 50 is about 6 μm to 30 μm, preferably 10 μm to 20 μm. If it exceeds 30 μm, flexibility is poor, and if it is less than 6 μm, protection of the electrode layer 40 may become insufficient.

In addition to the resist layer 50, a surface protective layer 60 may be further provided. The surface protective layer 60 may use a resin or an Elastomer (Elastomer). Among these, in consideration of the attachment to other members, the touch, and the like, a soft elastomer is preferable, and examples thereof include a thermosetting rubber and a thermoplastic elastomer.

The surface protective layer 60 is preferably made of a material having a high dielectric constant. The surface protective layer 60 having a high dielectric constant can be obtained by using a urethane resin having a high dielectric constant, a fluorine resin such as polyvinylidene fluoride, or a filler added to improve the dielectric constant such as barium titanate or titanium oxide. The thickness of the surface protection layer 60 is as thin as possible within a range in which a desired protective effect of the protective electrode layer 40 can be obtained. This is because the thinner the sensor, the higher the sensor sensitivity.

In order to laminate the electrode film 20 on the curved surface of the curved molded body 10, the electrode film 20 is bonded to the curved molded body 10 using an adhesive. As the Adhesive, a general liquid Adhesive may be used, but an Adhesive sheet called an optical clear Adhesive (optical Adhesive) is preferably used. This is because the workability of adhering the electrode film 20 to the curved molded body 10 is excellent.

By adhering the electrode film 20 to the curved surface of the curved molded body 10, the island portions 31 are densely arranged in the hemispherical detection region P where a capacitance change should be detected. The density is such that, when a change in capacitance due to a finger touch is detected, at least a part of the island 31 is present within the range of the area of the finger touching the detection region P. This is because, with this arrangement, it is possible to detect a capacitance change by contacting a certain island 31 regardless of the position in the touch detection region P.

Second embodiment (FIG. 6)

As shown in fig. 6, in the capacitive sensor 2 according to the second embodiment, the metal wiring 42 is not formed on the island portions 31 or the bridge portions 32 connecting the island portions 31 to each other, and the metal wiring 42 is provided only in a portion which is electrically connected from the terminal portion 33 to at least one of the island portions 31 belonging to each region. In the capacitive sensor 2 of this type, since the metal wiring 42 is not formed on the island portion 31 or the bridge portion 32 connected thereto, the transparency in the detection region P is improved. Therefore, it is suitable for applications requiring transparency. However, since conduction is performed only through the conductive film layer 41, the resistance value is likely to be higher and the detection accuracy is likely to be deteriorated, as compared with the capacitive sensor 1 according to the first embodiment.

Third embodiment (FIG. 7)

In the capacitive sensor 3 according to the third embodiment, in contrast to the capacitive sensor 2 according to the second embodiment, the conductive film layer 41 is not formed on the island portions 31 or the bridge portions 32 connecting the island portions 31 to each other, the entire portion where the conductive film layer 41 is formed is replaced with the metal wiring 42, and the electrode layer 40 is formed entirely of the metal wiring 42, including the portion that is electrically connected from the terminal portion 33 to at least one of the island portions 31 belonging to each region. In the capacitive sensor 3 of this embodiment, since the metal wiring 42 is formed in all the island portions 31 or the bridge portions 32 connecting the island portions 31, it is preferable in that the capacitive sensor 3 having very good conductivity, low resistance, and excellent sensitivity can be formed. However, it is difficult to apply the detection region P to a use requiring transparency.

Fourth embodiment

Unlike the

capacitive sensors

1, 2, and 3 described in the previous embodiments, the capacitive sensor according to the fourth embodiment is not divided into a plurality of detection regions, and can detect one ON/OFF (ON/OFF) in the entire hemispherical detection region. In such a capacitive sensor, the metal layer is entirely conductive and connected to the terminal portion.

Modifications of the embodiment (FIGS. 8 to 12)

The above embodiments are examples of the present invention, and modifications of the embodiments, additions and combinations of known techniques, and the like may be made without departing from the scope of the present invention, and these techniques are also included in the scope of the present invention.

As shown in fig. 8, the layer structure of the capacitance sensor may be a structure in which an electrode film 20 is attached to the inner surface of the curved molded body 10. In addition, as shown in fig. 8, 2 layers of a resist layer 50 may be provided on the inner surface of the base film 30.

In the above embodiment, the example in which the detection region P is divided into 5 regions a to E is shown in fig. 5, but the detection region may be divided into 4 regions and the island-bridge-like extensions 30a to 30d may be provided for each region as in the capacitive sensor 4 shown in fig. 9.

As in the capacitive sensor 5 shown in fig. 10, the detection region may be divided into 8 regions. In the modification of fig. 10, the detection region is divided into 4 regions in the circumferential direction (island bridge-like extensions 30a1 and 30a2, island bridge-like extensions 30b1 and 30b2, island bridge-like extensions 30c1 and 30c2, island bridge-like extensions 30d1 and 30d2), and is divided into 2 regions in the height direction (for example, island bridge-like extensions 30a1 at the lower stage and island bridge-like extensions 30a2 at the upper stage). Therefore, in this modification, the base film 30 has 8 island bridge extensions 30a 1-30 d 2. Accordingly, since the area is subdivided, it is possible to detect various inputs corresponding to the difference in the contact position.

In the above embodiment, as shown in fig. 5, an example in which the curved molded body 10 is hemispherical is illustrated, but in the capacitance sensor 6 shown in fig. 11, the curved molded body 10 has a truncated cone shape. The curved molded body 10 is formed in a Dial (Dial) shape in which the outer peripheral surface is curved in the height direction and is circular in the circumferential direction. In this way, only the electrode film 20 may be provided on the outer peripheral surface of the scale disk-shaped curved molded body 10. In this case, since the curved molded body 10 has a dial shape, it can be configured as a rotation input member for rotating the curved molded body 10. That is, in this modification, it is possible to configure the input operation member that realizes both the rotation input by the rotation operation of the capacitive sensor 6 and the touch input by the capacitive sensor 6.

As shown in fig. 5, in the above embodiment, the example in which the curved molded body 10 is hemispherical is exemplified, but the curved molded body 10 shown in fig. 12 is an elliptical dome shape. Island portions 31 each having a half-cross elliptical shape are provided on one side and the other side of the curved molded body 10 with respect to the major axis thereof. Further, a bridge portion 32 is formed to connect the island portions 3 to each other. The bridge portion 32 passes through the top of the curved molded body 10 and is elongated in the short axis direction of the curved molded body 10.

The capacitive sensor of the present invention can be used for an Interface (Interface) of a toy, an operation panel of a game machine, and an operation surface of an audio device. When a capacitive sensor is provided ON a surface having a curvature of an interface of a toy or an operation panel of a game machine and the interface or the operation panel is held in a palm-wrapped manner, a plurality of ON/OFF states (ON/OFF states) can be sensed depending ON the wrapped range, and the intensity of the output can be given. Further, a capacitance sensor is provided on a curved surface of the audio device, and by using the curved surface as an operation surface and sliding a finger, it is possible to advance to the next tune or increase or decrease the volume.

Description of the reference numerals

1. 2, 3,4, 5, 6, 7: a capacitance sensor,

10: a curved surface molding,

10 a: curved surface (curved surface portion),

11: a sea part,

20: an electrode film,

30: a base film,

30a to 30 e: an island bridge-shaped extension part,

31: an island part,

32: a bridge part,

33: a terminal portion,

40: an electrode layer,

40 a: an island electrode layer,

40 b: a bridge electrode layer,

41: a conductive film layer,

42: a metal wiring,

50. 50a, 50 b: an anti-corrosion layer,

60: a surface protective layer,

P: a detection region,

A to E: a region,

R1-R4: a partial enlarged view.

Claims

1. A capacitance sensor having an electrode film including an insulating base film attached to a sensor holder and an electrode layer provided on the base film,

the base film has one or more bridge-like extensions each having a bridge portion laminated along a curved surface of a curved surface portion of the sensor holder and a plurality of island portions connecting the plurality of island portions to each other along the curved surface portion,

the electrode layer has an island electrode layer provided on the island and a bridge electrode layer provided on the bridge.

2. A capacitive sensor according to claim 1,

the island bridge-like extensions have a configuration in which the island portions and the bridge portions are alternately arranged in series.

3. A capacitive sensor according to claim 1 or 2,

the bridge-like extension portion has a configuration in which a plurality of bridge portions are branched from the island portion and arranged in parallel.

4. A capacitive sensor according to any one of claims 1 to 3,

and the electrode film is provided with a terminal part for conducting and connecting the electrode layer with an external device.

5. A capacitive sensor according to any one of claims 1 to 4,

the bridge portion is in a thin band shape having a width narrower than that of the island portion.

6. A capacitive sensor according to any one of claims 1 to 5,

the plurality of islands include a plurality of categories of different sizes.

7. A capacitive sensor according to claim 4,

the electrode layer is formed of a conductive film layer and a metal wiring,

the metal wiring is provided so as to be continuous from the terminal portion and to border an outer edge of the island electrode layer.

8. A capacitive sensor according to any one of claims 1 to 7,

a plurality of the bridge portions are connected to one of the island portions.

9. A capacitive sensor according to any one of claims 1 to 8,

the island portion is circular.

10. A capacitive sensor according to any one of claims 1 to 9,

the curved surface of the curved surface portion of the sensor holder has a curved surface shape having a gaussian curvature of not 0, and the island portion has a shape arranged along the curved surface shape.

11. A capacitive sensor according to any one of claims 1 to 9,

the curved surface of the curved surface portion of the sensor holder has a curved surface shape having a positive gaussian curvature, and the island portion has a shape arranged along the curved surface shape.

12. A capacitive sensor according to any one of claims 1 to 11,

the ratio of the maximum width of each of the largest island portion and the smallest island portion among the island portions is 3: 1-10: 1.

13. a capacitive sensor according to any one of claims 1 to 12,

the sensor includes a plurality of the island-bridge-like extensions, and detection regions having different capacitances are formed for each of the island-bridge-like extensions.

14. A capacitive sensor according to any one of claims 1 to 13,

the sensor holder is configured to attach the electrode film to the curved surface portion.