JP2017175541A - antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily improve the invisibility of an antenna layer provided at a base material.SOLUTION: An antenna 10 includes: a base material 11 formed into a sheet shape; a net-like antenna layer 20 provided at the base material 11 and having light blocking effect and conductivity; and a net-like mesh layer 30 provided at the base material 11 and having light blocking effect. The mesh layer 30 is positioned at an outer side of the antenna layer 20 and partially disposed at an inner side of the antenna layer 20 when viewed in a normal direction of the base material 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an antenna in which an antenna layer for receiving, transmitting or transmitting / receiving radio waves is provided on a base material.

  For example, in an automobile, it is installed on a windshield or the like as an antenna for receiving various radio waves such as TV radio waves and FM radio waves, and radio waves related to position coordinate information from GPS (global positioning system) satellites used in car navigation systems. A film antenna is known. A general film antenna is configured by providing an antenna layer made of a metal foil or the like on a transparent substrate such as a transparent polyester film. In such a film antenna, the antenna layer is opaque. Therefore, the antenna layer is in a state where it can be visually observed, although it does not significantly disturb the field of view. On the other hand, an antenna that improves invisibility by forming the antenna layer with a transparent ITO film (indium oxide film) is also known.

  A film antenna having an opaque antenna layer made of a metal foil or the like has good conductivity, but it is difficult to use it appropriately in applications where invisibility is strongly required. Therefore, the application range is restricted. For example, when it is provided on the screen of a display panel of a mobile phone, the visibility is remarkably impaired, making application difficult. On the other hand, when an ITO film is used, it can be applied to a display panel or the like. However, since the conductivity of the ITO film is generally inferior to that of a metal, when attempting to secure transparency with a typical film thickness of several tens of nanometers, a situation in which sufficient performance as an antenna cannot be obtained may occur. Therefore, even when the ITO film is used, there is a problem of limitation of the application range. In addition, since the ITO thin film is more fragile than the gold foil, there is a problem that if the ITO film is deformed during the manufacturing process, it tends to crack or break.

  In view of the above problems, the present inventors have previously proposed an antenna in which an antenna layer provided on a transparent substrate is formed in a mesh shape (see Patent Document 1 and Patent Document 2). According to this antenna, good invisibility and conductivity can be ensured. Such a so-called transparent antenna is considered to be able to further improve the quality by applying an invisibility technique or the like in the mesh electrode of the touch panel.

JP 2011-66610 A JP 2011-66691 A

  By the way, the mesh-shaped electrode in a touch panel is normally provided in a wide range on a panel surface. On the other hand, when an antenna having a mesh-like antenna layer is applied to an actual product, the antenna layer is locally installed on, for example, a part of a windshield or a part of a display of a mobile phone. Is assumed. Here, the present inventor has found that in such a local installation mode of the antenna layer peculiar to the transparent antenna, there arises a problem that the antenna layer is relatively easily recognized by the local installation.

  The present invention has been made in consideration of the above-described points, and an object thereof is to provide an antenna that can easily increase the invisibility of an antenna layer provided on a base material.

The antenna according to the present invention comprises:
A base material formed into a sheet,
A mesh-like antenna layer provided on the base material and having light shielding properties and conductivity;
A mesh-like mesh layer provided on the substrate and having a light shielding property,
When viewed from the normal direction of the substrate, the mesh layer is located outside the antenna layer, and a part of the mesh layer is arranged inside the antenna layer.

  In the antenna according to the present invention, the antenna layer may be formed in the same mesh pattern shape as the mesh layer.

  In the antenna according to the present invention, when viewed from the normal direction of the base material, the mesh layer is located outside the antenna layer in at least two of the four directions of upper, lower, left, and right determined by the base material. May be.

  In the antenna according to the present invention, the base material is provided with an extraction electrode portion that is electrically connected to a part of the outer peripheral portion of the antenna layer and extends outward from the antenna layer, and the mesh layer includes the antenna layer It may be located so as to surround the entire region of the outer peripheral portion excluding the connection position of the extraction electrode portion.

  In the antenna according to the present invention, a portion of the mesh layer disposed inside the antenna layer extends from a portion of the mesh layer located outside the antenna layer to the inside of the antenna layer. Also good.

  In the antenna according to the present invention, the antenna layer may be provided on one surface of the base material, and the mesh layer may be provided on the other surface of the base material.

  In the antenna according to the present invention, the antenna layer includes a plurality of antenna conductors arranged in a mesh pattern on the base material, and a plurality of antenna opening areas are defined by the plurality of antenna conductors, and the mesh layer includes the mesh layer, The substrate may include a plurality of mesh conductors arranged in a mesh shape, and a plurality of mesh opening regions may be defined by the plurality of mesh conductors.

  In the antenna according to the present invention, at least one of the antenna conductor and the mesh conductor is laminated on a main body layer made of a metal material, and on the base material side and / or on the opposite side of the base material with respect to the main body layer. A low reflection layer made of copper nitride containing oxygen atoms at a depth of 5 nm or more from the surface, and the thickness of the low reflection layer is 10 nm to 60 nm, and the reflection Y value of the low reflection layer May be 30% or less.

In the antenna according to the present invention, the average value m of the area of the antenna opening region in the antenna layer and the standard deviation σ of the area of the antenna opening region may satisfy the following expression.
3 ≦ 3σ / m × 100 ≦ 20

In the antenna according to the present invention, an average value m of the area of the mesh opening area in the mesh layer and a standard deviation σ of the area of the mesh opening area may satisfy the following expression.
3 ≦ 3σ / m × 100 ≦ 20

  In the antenna according to the present invention, the antenna layer and the mesh layer are provided at different positions in the normal direction, and when viewed from the normal direction, the antenna layer and the mesh layer overlap each other, The mesh pattern shape of the antenna layer and the mesh pattern shape of the mesh layer may be aligned with each other.

  In the antenna according to the present invention, the substrate may be transparent.

In the antenna according to the present invention, the antenna layer includes copper as a main component, is provided on one surface of the base material via a transparent adhesive layer, and is formed on the surface of the antenna layer on the transparent adhesive layer side. total light reflectivity, determined in accordance with the 8722 diffuse light reflectance for _{(R SCI)} ratio _{(R SCE) (R SCE /} R SCI) may be 0.4 or less.

In the antenna according to the present invention, the mesh layer includes copper as a main component, and is provided on one surface of the base material via a transparent adhesive layer, and the JIS Z of the surface of the mesh layer on the transparent adhesive layer side is provided. total light reflectivity, determined in accordance with the 8722 diffuse light reflectance for _{(R SCI)} ratio _{(R SCE) (R SCE /} R SCI) may be 0.4 or less.

  In the antenna according to the present invention, the base material further includes a mesh-like second antenna layer provided at a position different from the antenna layer in the normal direction and having light shielding properties and conductivity, and the base material is normal. When viewed from the direction, the second antenna layer may be provided inside the antenna layer.

  In the antenna according to the present invention, the antenna layer may be formed in the same mesh pattern shape as the second antenna layer.

  According to the present invention, the invisibility of the antenna layer provided on the substrate can be easily increased.

FIG. 1 is a plan view of an antenna according to an embodiment of the present invention. FIG. 2 is an enlarged view of an example of a region indicated by II in FIG. 3 is a cross-sectional view of the antenna taken along line III-III in FIG. FIG. 4 is a diagram showing a mobile phone to which the antenna shown in FIG. 1 is applied. FIG. 5 is a diagram showing an automobile to which the antenna shown in FIG. 1 is applied. FIG. 6 is a diagram showing a building to which the antenna shown in FIG. 1 is applied. FIG. 7 is a diagram showing an RFID tag to which the antenna shown in FIG. 1 is applied. FIG. 8 is a view corresponding to the cross-sectional view of the antenna of FIG. 3, and is a cross-sectional view of the antenna in a modified example. FIG. 9 is a view corresponding to the cross-sectional view of the antenna of FIG. 3, and is a cross-sectional view of the antenna in another modification. FIG. 10 is a diagram corresponding to the enlarged view of FIG. 2, and is an enlarged view of a plan view of an antenna in a modified example. 11 is a cross-sectional view of the antenna along the line XI-XI in FIG. FIG. 12 is a view corresponding to the cross-sectional view of the antenna of FIG. 11, and is a cross-sectional view of the antenna in another modification. FIG. 13 is a view corresponding to the cross-sectional view of the antenna of FIG. 11 and is a cross-sectional view of an antenna of still another modified example. FIG. 14 is a diagram corresponding to the enlarged view of FIG. 2, and is an enlarged view of a plan view of an antenna in another modification. 15 is a cross-sectional view of the antenna taken along line XV-XV in FIG. FIG. 16 is a diagram corresponding to the enlarged view of FIG. 2 and is an enlarged view of a plan view of an antenna in still another modification. 17 is a cross-sectional view of the antenna along the line XVII-XVII in FIG. FIG. 18 is a plan view of an antenna layer of an antenna according to still another modified example of the present invention. FIG. 19 is an enlarged view of FIG. FIG. 20 is a diagram showing a general image display mechanism.

  Embodiments of the present invention will be described below with reference to the drawings.

  In this specification, terms such as “layer”, “sheet”, and “film” are not distinguished from each other based only on the difference in designation. For example, the “layer” is a concept including a member that can be called a sheet or a film. Furthermore, as used in this specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel” and “orthogonal”, length and angle values, and the like are bound to a strict meaning. Therefore, it should be interpreted including the extent to which similar functions can be expected. In the drawings referred to in this embodiment, the same portions or portions having similar functions are denoted by the same reference symbols or similar symbols, and repeated description thereof may be omitted. In addition, the dimensional ratio in the drawing may be different from the actual ratio for convenience of explanation, or a part of the configuration may be omitted from the drawing.

(Schematic configuration of antenna)
1 is a plan view of an antenna 10 according to an embodiment of the present invention, FIG. 2 is an enlarged view of a region indicated by II in FIG. 1, and FIG. 3 is taken along line III-III in FIG. It is sectional drawing. As shown in FIGS. 1 to 3, the antenna 10 according to the present embodiment is a so-called transparent antenna, and is formed in a sheet-like and transparent base material 11, and provided on the base material 11. A pair of mesh-like antenna layers 20 having a property and a mesh-like mesh layer 30 provided on the substrate 11 and having at least a light shielding property.

  The illustrated antenna 10 is configured as a half-wave dipole antenna for radio wave transmission as an example. The base material 11 is provided with an extraction electrode portion 13 that is electrically connected to a part of the outer peripheral portion of each of the pair of antenna layers 20 and extends outward from the antenna layer 20. Each antenna layer 20 is electrically connected to a common power feeding unit 7 via a corresponding extraction electrode unit 13 and external wiring.

  The power feeding unit 7 corresponds to an AC power supply that supplies a signal to be transmitted as an AC current (voltage), and includes an oscillation circuit, a modulation circuit, an amplification circuit, and the like. When the antenna 10 is configured as a receiving half-wave dipole antenna, a receiving circuit including a tuning circuit, an amplifier circuit, a frequency conversion circuit, a demodulation (detection) circuit, and the like is connected instead of the power feeding unit 7.

  In the half-wave dipole antenna, the length (L1 + L2) of the antenna layer 20 shown in FIG. 1 is ½ times the wavelength of the radio wave to be transmitted or received. When the frequency of the radio wave to be transmitted or received is 2.45 GHz, the wavelength is about 122.4 mm, so the length of the antenna layer 20 (L1 + L2) is about 61.2 mm, and the length of one antenna layer 20 Is about 30.6 mm. In addition, although the dimension of the width | variety shown by E in the figure of the antenna layer 20 is suitably set by the resistance of the antenna layer 20 desired, for example, about 5-50 mm may be sufficient.

(Layer structure)
The layer configuration of the antenna 10 of the present embodiment will be described with reference to FIG. In the present embodiment, the antenna 10 is composed of a single-layer member having a first surface 11a and a second surface 11b with which the base material 11 is opposed to each other. The antenna layer 20 and the extraction electrode portion 13 are provided on the first surface 11 a of the base material 11 via the transparent adhesive layer 12, and the transparent surface of the base material 11 is provided via the transparent adhesive layer 12. The mesh layer 30 is provided. That is, the antenna layer 20 and the mesh layer 30 are provided at different positions in the normal direction of the substrate 11. In the present embodiment, the antenna layer 20 includes a main body layer 21a made of a metal material, and a low reflection layer 21b made of copper nitride laminated on the side opposite to the base material 11 side with respect to the main body layer 21a. Contains. Similarly, the mesh layer 30 includes a main body layer 31a made of a metal material, and a low reflection layer 31b made of copper nitride laminated on the side opposite to the base material 11 side with respect to the main body layer 31a.

  Moreover, in this Embodiment, in the antenna layer 20, the surface by the side of the base material 11 (surface by the side of the transparent adhesive layer 12) is the smooth surface 20a with low light scattering property, and is the opposite side to the base material 11 side. Is a non-smooth surface 20b. Similarly, in the mesh layer 30, the surface on the base material 11 side (surface on the transparent adhesive layer 12 side) is a smooth surface 30a having a low light scattering property, and the surface opposite to the base material 11 side is non-surface. It is a smooth surface 30b. Here, the smooth surface in the present embodiment means “mirror surface”, and the non-smooth surface means “rough surface”. In the metal foil manufacturer, the surface of the outer surface (front and back surfaces) of the metal foil is subjected to physical or chemical treatment that increases the degree of unevenness on the surface, and the surface on the side where the degree of unevenness is relatively increased. It is called “rough surface” (otherwise, “roughened surface” or “matte surface”). On the other hand, the surface on the other side is referred to as “mirror surface” (also referred to as “smooth surface”, “glossy surface”, or “mirror surface”). “Rough surface” and “mirror surface” as used in the present embodiment are defined as the same terms as “rough surface” and “mirror surface” as described by the metal foil manufacturer as described above.

  In the example shown in FIG. 3, the antenna layer 20 and the mesh layer 30 are exposed to the outside, but the antenna layer 20 and the mesh layer 30 may be covered with a transparent resin layer as necessary. Such a resin layer can be formed, for example, by applying a liquid composition containing a resin to the uneven surface formed by the antenna layer 20 and the mesh layer 30 on the substrate 11. The liquid composition is not particularly limited as long as it contains a transparent resin, and a known resin may be appropriately employed.

  In the present embodiment, the base material 11 is a single layer, but the base material 11 may have a multilayer structure including a plurality of layers. The antenna layer 20 and the mesh layer 30 have a multilayer structure, but may have a single layer structure. As will be described later, the low reflection layers 21b and 31b are provided to reduce the reflectance, but a blackening layer may be used instead of the low reflection layers 21b and 31b. Moreover, although the surface by the side of the base material 11 of the antenna layer 20 and the mesh layer 30 is a smooth surface, the surface on the opposite side is a non-smooth surface, but the surface of both sides may be a smooth surface. However, the surfaces on both sides may be non-smooth surfaces. Hereinafter, each component of the antenna 10 will be described in detail.

(Base material)
As the base material 11, for example, a sheet or plate made of an organic material such as resin or an inorganic material such as glass is used. When it is strongly desired to secure a field of view in the antenna 10, the higher the transparency of the base material 11, the better. In this case, it is desirable that the base material 11 has a light transmittance such that the light transmittance in the visible light region of 380 to 780 nm is 70% or more, more preferably 80% or more. The light transmittance can be measured using a spectrophotometer (for example, UV-3100PC manufactured by Shimadzu Corporation) and a value measured in the air at room temperature. Moreover, it is preferable that the haze value based on JISK7105-1981 of the base material 11 is 10% or less, Furthermore, it is preferable that it is 2.0% or less, It is especially preferable that it is 1.0% or less. .

  Examples of the resin used as the material of the substrate 11 include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, and the like. Polyester resins such as polyester resins, polyamide resins such as nylon 6, polyolefin resins such as polypropylene, polymethylpentene and cycloolefin polymers, acrylic resins such as polymethyl methacrylate, styrene resins such as polystyrene and styrene-acrylonitrile copolymers, Examples thereof include cellulose resins such as triacetyl cellulose, imide resins, and polycarbonate resins. These resins may be used alone or as a plurality of types of mixed resins (including polymer alloys). When the substrate 11 is a resin film, a uniaxially stretched or biaxially stretched film is more preferable in terms of mechanical strength. In addition, additives such as a filler, a plasticizer, and an antistatic agent may be appropriately added to these resins as necessary.

  Examples of the glass constituting the substrate 11 include soda glass, potash glass, borosilicate glass, and quartz glass. Usually, glass is used in the form of a thick plate.

  The thickness of the substrate 11 is not particularly limited, but is usually 12 to 5000 μm, preferably 50 to 500 μm, more preferably 50 to 200 μm in the case of a film, and 500 to 3000 μm in the case of a plate. Within such a thickness range, the mechanical strength is sufficient, warping, loosening, breakage, etc. are prevented, and it is easy to supply and process in a continuous belt shape. The substrate 11 is preferably made of a flexible resin film or plate in view of good manufacturing processability and reduced weight and cost. Moreover, in the base material 11 which consists of resin films etc., well-known, such as corona discharge treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, preheat treatment, dust removal treatment, vapor deposition treatment, alkali treatment, etc. The easy adhesion treatment may be performed. The base material 11 may be colored transparent or opaque.

(Transparent adhesive layer)
The transparent adhesive layer 12 is capable of adhering the antenna layer 20 and the mesh layer 30 to the base material 11, and the type of the transparent adhesive layer 12 is not particularly limited as long as the layer has sufficient transparency in the present embodiment. It is not something. However, in the present embodiment, after the antenna layer 20 and the mesh layer 30 are bonded to the metal foil and the base material 11 via the transparent adhesive layer 12, the metal foil is patterned by etching. It is preferable that the transparent adhesive layer 12 has etching resistance. Specific examples include polyurethane resins such as polyurethane ester resins and two-component curable urethane resins, acrylic resins, polyester resins, and epoxy resins. The transparent adhesive layer 12 may be an ultraviolet curable type or a thermosetting type. In particular, from the viewpoint of adhesion to the base material 2, a polyurethane resin, an acrylic resin, a polyester resin, particularly a two-component curable urethane resin is preferable.

  The film thickness of the transparent adhesive layer 12 is preferably in the range of 0.5 μm to 50 μm, particularly in the range of 1 μm to 20 μm. Thereby, the base material 11 and the antenna layer 20 and the mesh layer 30 can be firmly bonded, and the base material 11 is an etching solution such as iron oxide when the antenna layer 20 and the mesh layer 30 are etched. This is because it can be prevented from being affected by the above. Moreover, it is preferable that the refractive index of the transparent adhesive layer 12 exists in the range of 1.41-1.59 from a viewpoint of interface reflection reduction by the refractive index difference with the base material 11, and also 1.48-1. It is preferable to be within the range of 52.

(Antenna layer)
Next, the antenna layer 20 will be described with reference to FIG. The antenna layer 20 includes a plurality of antenna conductors 21 arranged in a mesh pattern on the first surface 11 a of the substrate 11, and the plurality of antenna conductors 21 define a plurality of antenna opening regions 22. In the present embodiment, the antenna lead wire 21 means a linear portion that extends between two branch points 23 at a plurality of branch points 23 scattered in the antenna layer 20 to define the antenna opening region 22. Yes.

The antenna layer 20 in the present embodiment has a mesh pattern shape in which a certain rectangular antenna opening region 22 is spread without gaps. Specifically, the antenna opening regions 22 are arranged at a constant pitch in a first direction d ₁ and a second direction d ₂ that intersect each other. That is, the antenna aperture area 22 includes a plurality of antenna wires 21 which are arranged at a constant pitch P1 in the direction of each orthogonal linearly extending and first direction d ₁ in the first direction d _1, each of the second direction A plurality of antenna conductors 21 extending linearly in d ₂ and arranged in a direction perpendicular to the second direction d ₂ and having a constant pitch P ₂ that is the same as the constant pitch P 1 are defined. As a result, the antenna opening regions 22 included in the illustrated antenna layer 20 are all formed in the same rectangular shape, in particular, a rhombus shape. Note that the above-described mesh pattern shape means a symbol determined by the shape, pitch, size, and the like of the opening region in the present embodiment.

  As shown in FIG. 1, in the present embodiment, each of the pair of antenna layers 20 is formed in a rectangular shape as indicated by the outline FL1, and is disposed so as to face each other. Here, as shown in FIGS. 1 and 2, the contour line FL1 means a line defined by connecting the ends of the plurality of antenna conductors 21 located on the outermost periphery in the antenna layer 20 with straight lines, and more Specifically, it means a line defined by connecting adjacent end portions of the end portions of the plurality of antenna conductor wires 21 located on the outermost periphery sequentially with straight lines. In the present embodiment, the antenna layer 20 has a rectangular shape, but such a shape is not particularly limited as long as a desired radio wave can be transmitted or received. It may be formed in a meandering shape.

  Further, as described above, the antenna layer 20 (antenna conductor 21) in the present embodiment has the main body layer 21a and the low reflection layer 21b made of copper nitride, and the low reflection layer 21b is made of copper nitride. Therefore, although copper is contained as a main component, the main body layer 21a also contains copper as a main component. Therefore, the antenna layer 20 contains copper as a main component as a whole. However, the material of the antenna conductor 21 is not limited to copper, and may be formed of, for example, gold, silver, aluminum, or the like.

  The thickness of the antenna layer 20 may be appropriately selected from the viewpoints of high conductivity, processability, mechanical strength, and the like depending on the material. Specifically, when the main component is copper, the thickness is 0. .1 μm or more and 20 μm or less is preferable, and 0.5 μm or more and 5 μm or less is more preferable. The thickness of the second antenna layer 30 is more preferably 1 μm or more and 3 μm or less. When the thickness is small, the conductivity and mechanical strength are lowered, and when the thickness is thick, the workability is lowered.

  Further, in the present embodiment, the antenna layer 20 is formed in a mesh pattern shape in which square-shaped antenna opening regions 22 are regularly arranged. The antenna pattern of the antenna layer 20 may be a honeycomb pattern shape or a square lattice. It may be a pattern shape such as a shape, a rectangular lattice shape, a triangular lattice shape, or a Voronoi mesh, in which irregularly shaped opening regions are irregularly defined.

(Mesh layer)
Next, the mesh layer 30 will be described with reference to FIG. Like the antenna layer 20, the mesh layer 30 includes a plurality of mesh conductors 31 arranged in a mesh pattern on the second surface 11 b of the substrate 11, and a plurality of mesh opening regions 32 are defined by the plurality of mesh conductors 31. It is made. The mesh conducting wire 31 means a linear portion that extends between the two branch points 33 at the branch points 33 scattered in the mesh layer 30 and defines the mesh opening region 32.

  As shown in FIGS. 1 to 3, the mesh layer 30 in the present embodiment is located outside the antenna layer 10 when the base material 11 is viewed from the normal direction of the base material 11, and the antenna layer 20. , A part of the antenna layer 20 is disposed inside the antenna layer 20 so as to overlap the overlapping portion R. More specifically, a part of the mesh layer 30 disposed inside the antenna layer 20 extends from the portion of the mesh layer 30 located outside the antenna layer 20 to the inside of the antenna layer 20.

Further, as shown in FIG. 2, the mesh layer 30 in the present embodiment is formed in the same mesh pattern shape as the antenna layer 20, and a mesh in which a certain square mesh opening region 32 is laid without gaps. It has a pattern shape. Accordingly, the mesh opening regions 32 are arranged at a constant pitch in the first direction d ₁ and the second direction d ₂ that intersect each other. That is, the mesh opening region 32 includes a plurality of mesh wires 31 which are arranged at a constant pitch P1 in the direction of each orthogonal linearly extending and first direction d ₁ in the first direction d _1, each of the second direction It is defined by a plurality of mesh conductors 31 extending linearly in d ₂ and arranged at a constant pitch P ₂ that is the same as the constant pitch P 1 in a direction orthogonal to the second direction d ₂ . As a result, the mesh opening regions 32 included in the illustrated mesh layer 30 are all formed in the same quadrangular shape, in particular, a rhombus shape.

  As described above, the mesh layer 30 (mesh conductor 31) in the present embodiment also includes the main body layer 31a and the low reflection layer 31b made of copper nitride, and the low reflection layer 31b is copper nitride. Therefore, although copper is included as a main component, the main body layer 31a also includes copper as a main component. Therefore, the mesh layer 30 contains copper as a main component as a whole. In addition, the material of the mesh conducting wire 31 is not limited to copper, but may be formed of, for example, gold, silver, aluminum, or the like. The mesh layer 30 may be formed of a material different from that of the antenna layer 20, and may be formed of, for example, a resin.

  The mesh layer 30 in the present embodiment does not perform a desired function in the antenna or the defroster by conducting, but may be configured to perform a desired function in the antenna or the defroster. Also good. The thickness of the mesh layer 30 may be appropriately selected from the viewpoints of processability, mechanical strength, high conductivity, etc. when functioning in a defroster or antenna, depending on the material. In order to suppress and increase invisibility, the thickness is preferably the same as that of the antenna layer 20. Therefore, the thickness of the mesh layer 30 is preferably 0.1 μm or more and 20 μm or less, and more preferably 0.5 μm or more and 5 μm or less. Further, the thickness of the mesh layer 30 is more preferably 1 μm or more and 3 μm or less.

  In the present embodiment, the mesh layer 30 is formed in a mesh pattern shape in which square-shaped mesh opening regions 32 are regularly arranged. The mesh pattern shape of the mesh layer 30 is a honeycomb pattern shape, a square lattice, or the like. It may be a pattern shape such as a shape, a rectangular lattice shape, a triangular lattice shape, or a Voronoi mesh, in which irregularly shaped opening regions are irregularly defined. However, in order to suppress the difference in transmittance between the two, the mesh layer 30 is preferably formed in the same mesh pattern shape as the antenna layer 20.

(Positional relationship between antenna layer and mesh layer)
Hereinafter, the positional relationship between the antenna layer 20 and the mesh layer 30 will be described in detail. As described above, when the mesh layer 30 is viewed from the normal direction of the base material 11, a part of the mesh layer 30 is disposed inside the antenna layer 20 so as to overlap the antenna layer 20 at the overlapping portion R. ing. Here, a part of the mesh layer 30 disposed inside the antenna layer 20 extends from the portion of the mesh layer 30 located outside the antenna layer 20 to the inside of the antenna layer 20. In the illustrated example, the mesh layer 30 and the antenna layer 20 are parallel to each other.

  Specifically, as shown in FIG. 1, the mesh layer 30 in the present embodiment is positioned so as to surround the entire outer peripheral portion except the connection position of the extraction electrode portion 13 in each of the pair of antenna layers 20, and It extends from the outside to the inside of the aforementioned contour line FL1 that defines the external shape of the antenna layer 20, and overlaps the antenna layer 20 at the overlapping portion R. Here, the overlapping portion R means a portion where the antenna layer 20 and the mesh layer 30 overlap in a direction orthogonal to the contour line FL1. In the present embodiment, the portion of the mesh layer 30 located inside the contour line FL1 is located in the entire inner region of the outer peripheral portion excluding the connection position of the extraction electrode portion 13 of the antenna layer 20. Such a portion of the mesh layer 30 located inside the antenna layer 20 is not located in the entire area of the antenna layer 20 in the illustrated example, and defines a space overlapping with the antenna layer 20 in the normal direction. ing. In this space, elements different from the antenna layer 20 and the mesh layer 30 can be provided, and desired elements can be efficiently arranged in a limited space.

  In the present embodiment, as shown in FIG. 2, when viewed from the normal direction of the base material 11, the antenna layer 20 and the mesh layer 30 are in the overlapping portion, that is, in the overlapping portion R. The mesh pattern shape of the antenna layer 20 of the material 11 and the mesh pattern shape of the mesh layer 30 are aligned to form a single mesh pattern shape. According to such an arrangement, it is possible to suppress variations in light transmittance between the portion where the antenna layer 20 and the mesh layer 30 overlap and the other portion.

  When an antenna having a mesh-like antenna layer is applied to an actual product, the antenna layer is assumed to be installed locally on, for example, a part of a windshield or a part of a display of a mobile phone. The The inventor of the present invention has found that the problem that the antenna layer becomes easy to be visually recognized due to the local installation mode arises in earnest research premised on such installation mode peculiar to the antenna. In order to solve this problem, the antenna layer 20 fulfills the intended function of the antenna, but the antenna layer does not appear to be locally installed. The different mesh layers 30 are located outside the antenna layer 20, and the mesh layer 30 has a configuration in which part of the mesh layer 30 is arranged inside the antenna layer 20. According to such a configuration, the invisibility of the antenna layer 20 can be easily increased by the mesh layer 30 being invisible as if the antenna layer 20 was locally installed and becoming inconspicuous. it can.

  Moreover, in this Embodiment, when it sees from the normal line direction of the base material 11, for example, the antenna layer 20 in all four directions of the four directions of the top, bottom, left, and right corresponding to the top, bottom, left, and right in the drawing The mesh layer 30 is located outside. The present invention is not limited to such an embodiment. For example, it is preferable that the mesh layer 30 is located outside the antenna layer 20 in at least two of the above-described four directions of up, down, left, and right. . This is because the antenna layer 20 can be made sufficiently inconspicuous.

(Body layer and low reflection layer in antenna layer and mesh layer)
As described above, in the present embodiment, the invisibility of the antenna layer 20 is enhanced by the mesh layer 30, but in this embodiment, in addition to this, the invisibility is further enhanced and visibility in the field of view is increased. Ingenuity to enhance the above-mentioned main body layers 21a and 31a and the low reflection layers 21b and 31b. Hereinafter, the main body layers 21a and 31a and the low reflection layers 21b and 31b will be described. In this example, in the antenna layer 20 and the mesh layer 30, the main body layer 21a and the main body layer 31a have the same configuration, and the low reflection layer 21b and the low reflection layer 31b have the same configuration. Therefore, hereinafter, the main body layer 21a and the main body layer 31a will be described together, and the low reflection layer 21b and the low reflection layer 31b will be described together.

  Specifically, first, the main body layers 21a and 31a are layers for mainly ensuring conductivity, and more specifically within a range of 0.5 μm to 5 μm so that the thickness thereof is, for example, 20 μm or less. It is configured as follows. As a result, the thickness of the entire antenna conductor 21 or mesh conductor 31 can be prevented from being increased, and external light and video light (when the display is installed) are reflected on the side surface of the antenna conductor 21 or mesh conductor 31. This can be suppressed. Thereby, the improvement of invisibility and the improvement of visibility are achieved.

As described above, reducing the thickness of the main body layers 21a and 31a can achieve the effect of improving the invisibility and improving the visibility, while increasing the electric resistance value of the antenna conductor 21 or the mesh conductor 31. Can lead to that. In particular, it is not desirable that the resistance of the antenna conductor 21 is excessively large. Therefore, in the present embodiment, a metal material having a specific resistance equal to or lower than a desired value is used as a material constituting the main body layers 21a and 31a. For example, the specific resistance is 4.0 × 10 ^−6. Metal materials that are (Ωm) or less are used. Thereby, in particular, the electric resistance value of the antenna conductor 21 can be made sufficiently low. For example, the sheet resistance values of the main body layers 21a and 31a can be set to 0.3Ω / □ or less. As a metal material having a specific resistance of 4.0 × 10 ⁻⁶ (Ωm) or less for constituting the main body layers 21a and 31a, for example, 90% by weight or more of metal such as gold, silver, copper, and aluminum The containing material (metal simple substance, metal alloy, etc.) can be used. In the present embodiment, a material containing 99% by weight of copper is used as the main body layers 21a and 31a. In the present embodiment, the main body layers 21a and 31a are made of a copper foil (copper thin film) laminated on the base material 11 with the transparent adhesive layer 12 interposed therebetween.

  On the other hand, metal materials such as copper have high conductivity but exhibit a metallic luster. For this reason, when an untreated metal material is used as the antenna conductor 21 or the mesh conductor 31, visibility is hindered by the metallic luster of the antenna conductor 21 or the mesh conductor 31. In particular, since copper exhibits a reddish color peculiar to copper, it is more conspicuous than other metal materials such as silver, and this impedes visibility.

  In order to reduce such metallic luster peculiar to copper, for example, the conductive wire is oxidized to form a blackening treatment layer made of copper oxide on the surface of the conductive wire, thereby blackening (blackening) the surface of the conductive wire. Technology is known. However, the blackening treatment layer formed by the blackening treatment needs to have a certain thickness. Specifically, although it is a document related to the touch panel technology, for example, JP 2012-79238 A discloses a range of 0.2 μm or more and 2 μm or less as a preferable thickness of the blackening treatment layer. Further, a value of 2 μm is mainly adopted as the thickness of the conducting wire. In the conductive wire in which the blackening layer is formed in this way, reflection not to be ignored occurs not only on the surface of the conductive wire but also on the side surface of the conductive wire, or the image light from the display device is hindered by the side surface of the conductive wire. It is possible that

  Therefore, in the present embodiment, the present inventor does not blacken the main body layers 21a and 31a, but suppresses metallic luster on the surfaces of the main body layers 21a and 31a as compared with the main body layers 21a and 31a. Further, thin low reflection layers 21b and 31b are provided. Thereby, the metallic luster of the antenna conducting wire 21 or the mesh conducting wire 31 is reduced. Specifically, the low reflection layers 21b and 31b are layers made of copper nitride containing oxygen atoms at a depth of 5 nm or more from the surface. The film thickness of the low reflection layers 21b and 31b is in the range of 10 nm to 60 nm, for example, 40 nm. The reflection Y value (also referred to as luminous reflectance) of the low reflection layers 21b and 31b is 30% or less, and preferably 27% or less. Here, the reflection Y value is a value according to the provisions of JIS Z 8722-1982, and means a reflectance with respect to light having a wavelength of around 550 nm.

  Generally, when the surface of a layer made of copper nitride is exposed to the atmosphere, the surface of the layer made of copper nitride may contain oxygen atoms by reacting with oxygen in the atmosphere (natural oxidation). However, according to the knowledge of the present inventors, the copper nitride that can be naturally oxidized in the copper nitride layer is copper nitride at a depth of about 0.1 nm from the surface. Therefore, when a layer made of copper nitride contains oxygen atoms at a depth of 5 nm or more from the surface, the oxygen atoms are not oxygen atoms derived from the natural oxidation of the surface, but from copper nitride at the time of film formation, for example. It can be considered that oxygen atoms are intentionally added to the layer. That is, the layer made of copper nitride containing oxygen atoms at a depth of 5 nm or more from the surface means a layer made of copper nitride intentionally added with oxygen atoms, although the method for adding oxygen atoms is not particularly limited. . Note that the expression “a layer made of copper nitride containing oxygen atoms at a depth of 5 nm or more from the surface” means that oxygen atoms are contained at a depth of 5 nm or more from the surface and oxygen atoms are also contained at a depth of less than 5 nm from the surface. Naturally, it includes a layer made of copper nitride.

  In the low reflection layers 21b and 31b configured using such copper nitride, the metallic luster is reduced as compared with the metallic luster in the main body layers 21a and 31a. The tinged color has been reduced. In addition, the low reflection layers 21b and 31b formed using such copper nitride have a significantly reduced reflection Y value compared to a layer made of copper nitride containing no oxygen atoms at a depth of 5 nm or more from the surface. Has been. For this reason, in this Embodiment, it becomes possible to suppress that invisibility and visibility fall by the reflected light from the antenna conducting wire 21 or the mesh conducting wire 31. FIG.

  The low reflection layers 21b and 31b have a smaller thickness than the main body layers 21a and 31a. Specifically, the thicknesses of the low reflection layers 21b and 31b are in the range of 10 nm to 60 nm. Therefore, it is suppressed that the thickness of the whole conducting wire becomes large. This suppresses reflection of external light or the like on the side surface of the antenna conductor 21 or the mesh conductor 31.

  Moreover, the reflectance of the light in the antenna conducting wire 21 or the mesh conducting wire 31 can also be lowered by setting the thickness of the low reflecting layers 21b and 31b within the range of 10 nm to 60 nm. The reason for this is not limited, but may be, for example, thin film interference that occurs in the low reflection layers 21b and 31b. The thin film interference is a phenomenon in which light reflected on one surface of the low reflection layers 21b and 31b interferes with light reflected on the other surface of the low reflection layers 21b and 31b. By setting the thicknesses of the low reflection layers 21b and 31b within the above-mentioned range of 10 to 60 nm, thin film interference occurs so as to weaken the reflected light, whereby the reflectance of light in the antenna conductor 21 or the mesh conductor 31 is increased. It can be considered to be reduced.

  The method for forming the thin low reflection layers 21b and 31b as described above is not particularly limited, and known thin film forming methods such as a sputtering method, a vacuum evaporation method, a CVD method, an ion plating method, and an electron beam method are used. Can be used. For example, when sputtering is used, oxygen is applied to a depth of 5 nm or more from the surface by applying discharge power to a target made of copper in an environment where nitrogen gas and oxygen gas controlled to a predetermined partial pressure exist. A layer made of copper nitride containing atoms can be obtained.

  In the present embodiment, the low reflection layers 21b and 31b are laminated on the main body layers 21a and 31a. However, the low reflection layers 21b and 31b are the surfaces of the main body layers 21a and 31a on the base material 11 side or the base layers. You may laminate | stack on the surface on the material 11 side, and the surface on the opposite side. Further, a blackened layer may be used in place of the low reflective layers 21b and 31b. For example, although the low reflection layer 21b is provided in the main body layer 21a, an aspect in which a blackening layer is provided in the main body layer 31a may be adopted.

(Surface characteristics of antenna layer and mesh layer)
Moreover, in this Embodiment, the device for reducing the haze in the antenna 10 is also made | formed. Below, the surface characteristic of the antenna layer 20 and the mesh layer 30 in this Embodiment is demonstrated. In the present embodiment, in order to reduce haze in the antenna 10, the surface of the antenna layer 20 and the mesh layer 30 on the substrate 11 side is devised. In this example, the surface characteristics of the antenna layer 20 and the mesh layer 30 are the same. Therefore, hereinafter, the antenna layer 20 and the mesh layer 30 will be described together.

Specifically, in the present embodiment, the diffused light with respect to the total light reflectance ( _RSCI ) measured according to JIS Z 8722 of the smooth surfaces 20a and 30a of the antenna layer 20 and the mesh layer 30 on the transparent adhesive layer 12 side. The ratio ( _RSCE / _RSCI ) of the reflectance ( _RSCE ) is 0.4 or less.

As described above, in the present embodiment, the main body layers 21a and 31a are made of a copper foil (copper thin film) laminated on the base material 11 with the transparent adhesive layer 12 interposed therebetween. In this case, the antenna layers 20 and the mesh layers 30 provided on the base material 11 are open areas 22 and 32, that is, the exposed surface of the transparent adhesive layer 12 is a surface facing the base material 11 side of the copper foil. The fine uneven shape (smooth surface with low light scattering property) is transferred. Therefore, the diffused light reflectivity (R _SCI ) with respect to the total light reflectivity ( _RSCI ) measured in accordance with JIS Z 8722 on the surface of the transparent adhesive layer 12 exposed from the opening regions 22 and 32 of the antenna layer 20 and the mesh layer 30 ( R _SCE ) ratio (R _SCE / R _SCI ) and the surfaces of the antenna layer 20 and the mesh layer 30 that are in contact with the conductive wires 21 and 31, that is, the antenna layer 20 and the transparent adhesive layer 12 of the mesh layer 30 (light scattering properties). considered and the ratio of the total light reflectance was measured in conformity with JIS Z 8722 of lower smooth surface) of _(diffuse light reflectance for _{R SCI) (R SCE) (} R SCE / R SCI), becomes equivalent to the value of It is done.

Therefore, in this embodiment, the numerical value of the light reflectance ratio (R _SCE / R _SCI ) on the surface of the transparent adhesive layer 12 exposed from the opening regions 22 and 32 of the antenna layer 20 and the mesh layer 30 is directly measured. In the form of a transparent antenna, i.e., because most of the light is transmitted through the exposed adhesive layer;
Base material 11 / transparent adhesive layer 12 / antenna layer 20 and mesh layer 30
In the laminate, the measurement light is incident from the substrate 11 side, passes through the intervening substrate 11 and the transparent adhesive layer 12, and is reflected by the surfaces of the antenna layer 20 and the mesh layer 30 ( ( _RSCE / _RSCI ) is measured and indirectly evaluated.

  As a result of experiments by the present inventors, the surface of the copper foil to be bonded to one surface of the base material 11 via the transparent adhesive layer 12 is smooth and exposed to the opening regions 22 and 32 to which this surface is transferred. It was confirmed that the surface of the transparent adhesive layer 12 to be able to reduce the haze of the antenna 10 obtained when light transmission is mainly parallel light transmitted light.

  Further, the present inventor has found that the surface of the metal foil can be distinguished from the rough surface and the mirror surface in appearance, but there is no difference in the numerical value represented by the JIS B 0601 arithmetic average roughness Ra. Here, the arithmetic average roughness Ra of JIS B 0601 is the reference length L extracted from the roughness curve in the direction of the average line, and the absolute value of the deviation from the average line of the extracted part to the measurement curve is summed. The average value. Further, in the experiment, even when the Ra of the rough surface of a certain metal foil is larger than the Ra of the rough surface of a metal foil different from this, when an antenna is produced from these metal foils, a metal with a large Ra It was also found that the foil had a smaller haze value after the etching treatment. Furthermore, in a certain metal foil, the mirror surface Ra is smaller than the rough surface Ra, but it has also been found that the mean square roughness Rq measured in a minute range is larger in the mirror surface than in the rough surface.

  From the above results, the present inventor found that the arithmetic mean roughness Ra, the appearance of the metal foil surface, and the haze value transferred to the surface of the transparent adhesive layer 12 in the opening regions 22 and 32 after the etching treatment. We found that there was no correlation. The correlation between the ten-point average roughness (specified in JIS B 0601 (1994 version)) that has been used as an index of specularity in the past and the haze transferred to the adhesive layer surface is the same. Not clear. Moreover, the average roughness showing the uneven | corrugated shape on the surface of metal foil changes with the methods to measure. From this, in the same arithmetic mean roughness Ra, the surface shape having a high unevenness frequency and a close unevenness interval has a large haze value after the etching process, while the unevenness frequency is low and the uneven interval is low. It is considered that the haze value after the etching process is small in a surface shape with a sparse and many flat portions.

  That is, conventionally, the haze after the etching process has been reduced in correlation with the ten-point average roughness Rz because the conditions such as the roughness of the rough surface of the metal foil surface, the density of the protrusions, etc. It is concluded that it is not a design standard that can be widely applied in general when the manufacturing method of metal foil, the rough surface fine uneven shape of the surface, the density of protrusions, etc. vary in various ways. The

As a result of the above studies, the present inventors can reduce the haze after the etching process with good correlation by making the surface of the copper foil to be bonded to the transparent adhesive layer 12 side into a mirror surface with low light scattering property. I found. Specifically, the surface of the copper foil bonded to one surface of the base material 11 via the transparent adhesive layer 12 is a diffused light with respect to the total light reflectance ( _RSCI ) measured according to JIS Z8722. When the ratio ( _RSCE / _RSCI ) of the reflectance ( _RSCE ) is in the range of 0.4 or less, the antenna layer 20 and the mesh layer after the etching process regardless of the value of the arithmetic average roughness Ra of the surface It has been found that the haze of light transmitted through 30 open regions 22 and 32 can be reduced. Accordingly, as described above, the diffused light reflectance (R _SCI ) with respect to the total light reflectance ( _RSCI ) measured according to JIS Z 8722 of the smooth surfaces 20a and 30a on the adhesive layer 12 side of the antenna layer 20 and the mesh layer 30 ( It is specified that the ratio of R _SCE ) (R _SCE / R _SCI ) is 0.4 or less. This ratio (R _SCE / R _SCI ) is more preferably 0.3 or less.

The ratio of the total light reflectance diffuse light reflectance for _{(R SCI) (R SCE)} (R SCE / R SCI) is an indicator that the surface shape of the metal foil (copper foil) represents whether easily scatters light When the shape of the surface of the metal foil (copper foil) is transferred to the transparent adhesive layer 12, the value directly affects the haze of the transmitted light of the antenna obtained. In the present embodiment, the surfaces on the base material 11 side of the antenna layer 20 and the mesh layer 30 are smooth surfaces 20a and 30a having low light scattering properties (by selecting the surface on which the copper foil is applied). , the total light reflectance of the surface of the antenna layer 20 and the transparent adhesive layer 12 in the opening region 22, 32 of the mesh layer 30 diffuse light reflectance for _{(R SCI)} the ratio of _{(R SCE) (R SCE /} R SCI) The specific range can be set, and the surface of the transparent adhesive layer 12 has a shape that hardly scatters transmitted light, so that haze can be reduced. In addition, the said specific reflective characteristic is acquired by raising the polish degree of the rolling roll surface which contacts the copper foil which forms the antenna layer 20 and the mesh layer 30. FIG.

Total light reflectance was measured in accordance with JIS Z 8722-1982 of the copper foil surface in the present embodiment _{(R SCI)} is in conformity with JIS Z 8722-1982, spectrophotometer (e.g., Konica Minolta Sensing CM-3600d) manufactured by Co., Ltd. is set to the reflection mode, the light source is standard light D65, the visual field is 2 °, the measurement diameter is 4 mmφ or more, and both the diffuse reflection light and the specular reflection light are reflected in the detector. The Y value (Y of tristimulus values XYZ) is measured by setting the SCI (Special Component Include) mode in which the (integrated) intensity of the total reflected light is measured. Further, JIS Z 8722-1982 diffuse light reflectance was measured according to the copper foil surface _{(R SCE)} is similarly using spectrophotometer, a light source, field of view, and measuring the diameter is the same as the The detector is set to an SCE (Special Component Exclude) mode that measures the (integral) intensity of only the diffuse reflected light of the reflected light, and the Y value (Y of tristimulus values XYZ) is measured. is there. Here, the tristimulus value XYZ is defined by JIS Z 8722-1982. A sample placed in an ideal environment is illuminated with a standard light source, and the spectroscopic analysis result of reflected light from the sample is calculated. It is a value to be determined.

As described above, the degree of haze reduction has a low dependency (correlation) on the arithmetic average roughness Ra defined in JIS B 0601. However, if the value of Ra becomes too large, there is generally no mistake in increasing the surface irregularities, so the haze of the exposed surface of the transparent adhesive layer 12 tends to increase (weak correlation). In view of this point, it can be said that it is preferable to select a small Ra within a possible range on the assumption that a specific light reflectance ratio (R _SCE / R _SCI ) is set. Usually, Ra is set to 0.2 μm or less, more preferably 0.15 μm or less.

(Use)
Next, the use of the antenna 10 according to the present embodiment will be described. As an application of the antenna 10, first, an antenna for a mobile phone is cited. In this case, for example, as shown in FIG. 4, the antenna 10 may be attached to a part of the casing 1 a of the mobile phone 1. The antenna 10 may be configured to receive and transmit radio waves in the telephone / internet communication function, and to receive radio waves such as television and radio broadcasts and GPS. The illustrated mobile phone 1 is of a two-fold type, and includes a display screen (subwindow) 1b on the outer surface in a folded state. And the antenna 10 is affixed on the whole display range of the display screen 1b. A feeding electrode (not shown) of the antenna 10 is connected to a transmission / reception unit in the mobile phone 1 via an input / output terminal provided on the outer frame of the display screen 1b. The antenna 10 may be partially attached to a part of the display screen 1b.

  The antenna 10 may be a car navigation antenna. In this case, for example, as shown in FIG. 5, the antenna 10 may be attached to the windshield 2 a of the automobile 2. The antenna 10 may be connected to the TV tuner of the car navigation device 2b and configured to transmit and receive radio waves from GPS satellites.

  The antenna 10 may be a security system antenna. In this case, for example, as shown in FIG. 6, the antenna 10 may be attached to the window glass 3 a of the building 3. The antenna 10 may be configured to transmit a signal to the receiving device when the window glass 3a is broken, thereby detecting an abnormality.

  The antenna 10 may be a product management antenna. In this case, for example, as shown in FIG. 7, in the RFID (radio frequency identification) tag 4 including the IC chip 4a and the antenna 10, when the antenna 10 receives the calling radio wave from the reader / writer, the RFID chip 4a stores the calling radio wave in the memory of the IC chip 4a. The antenna 10 may be configured to transmit information to the reader / writer. Thereby, information processing such as product entry / exit, inventory, and sales management may be performed.

(Antenna manufacturing method)
Next, a method for manufacturing the antenna 10 will be described. In the manufacturing method of the present embodiment, first, the total light reflectance was measured in conformity with JIS Z 8722 _{(R SCI)} diffuse light reflectance for the ratio of _{(R SCE) (R SCE /} R SCI) is 0.4 A step of preparing a copper foil having the following surfaces is performed. The copper foil used here has a surface having the specific reflection characteristics (smooth surface with low light scattering property).

Next, the copper foil is placed on the first surface 11a which is one surface of the substrate 11 and the second surface 11b which is the other surface through the transparent adhesive layer 12, and the R _SCE / R _SCI is 0. The process of laminating | stacking the surface below 4 facing the base material 11 is performed. In this step, first, a base material 11 is prepared, and a transparent adhesive layer 12 is formed by coating the first surface 11a and the second surface 11b of the base material 11 with a transparent adhesive. As a layer forming method of the transparent adhesive layer 12, a known layer forming method, for example, a coating method such as roll coating, comma coating, gravure coating, die coating, or screen printing or gravure in which partial formation in an arbitrary shape is easy. Printing methods such as printing can be appropriately employed. Next, the copper foil is laminated on the surface of the transparent adhesive layer 12 of the substrate 11 with the smooth surface side having a low light scattering property directed.

  Next, a copper nitride layer that becomes the low reflection layers 21b and 31b after completion is laminated on the copper foil on the transparent adhesive layer 12 of each of the first surface 11a and the second surface 11b. As a method for forming the copper nitride layer, a thin film forming method such as a sputtering method can be used as described above.

  Next, a process of forming the antenna layer 20 and the mesh layer 30 by etching the copper foil and the copper nitride layer into a predetermined pattern shape is performed. In this step, first, a resist layer is provided in a predetermined mesh pattern shape corresponding to the antenna layer 20 and the mesh layer 30 on the copper foil and copper nitride layer laminated on the base material 11 and covered with the resist layer. The antenna layer 20 and the mesh layer 30 are formed by an etching process that removes the resist layer after removing the copper foil and copper nitride layer that are not formed by etching (corrosion). Among the etching processing methods, it is preferable to adopt a so-called photolithography method from the viewpoint of fine processing accuracy.

  In the present embodiment, a photolithography method is performed as follows. That is, first, a photosensitive resist layer is formed in a predetermined pattern on the copper nitride layer of the substrate 11. The photosensitive resist layer has photosensitivity to light in a specific wavelength range, for example, ultraviolet rays. The type of the photosensitive resist layer is not particularly limited. For example, a photodissolvable photosensitive resist layer may be used, or a photocurable photosensitive resist layer may be used. Here, an example in which a photodissolvable photosensitive resist layer is used will be described.

  The photosensitive resist layer is formed in a pattern corresponding to the pattern of the antenna layer 20 and the mesh layer 30. For example, first, the photosensitive resist layer is coated on the entire surface of the copper nitride layer with a coater using a coater, and then the photosensitive resist material is exposed and developed in a predetermined pattern. Thus, a photosensitive resist layer having a predetermined pattern shape is formed.

  Next, copper foil and copper nitride are etched using the photosensitive resist layer as a mask. As described above, both the copper foil and the copper nitride are configured to contain copper. For this reason, copper foil and copper nitride can be etched simultaneously using the etching liquid which can dissolve copper. For example, an aqueous ferric chloride solution is used as the etching solution.

  Next, the photosensitive resist layer remaining on the body layers 21a and 31a and the low reflection layers 21b and 31b formed by etching is washed with a chemical solution that dissolves and removes the film, and a film removal process is performed. Thereby, the photosensitive resist layer can be removed. Thus, the antenna layer 20 having the main body layer 21a and the low reflection layer 21b is provided on the first surface 11a of the base material 11, and the mesh layer 30 having the main body layer 31a and the low reflection layer 31b is the first layer 11 of the base material 11. The antenna 10 of the present embodiment is manufactured by being provided on the two surfaces 11b.

(effect)
The antenna 10 according to the present embodiment described above includes a base material 11 formed in a sheet shape, a mesh-like antenna layer 20 provided on the base material 11 and having light shielding properties and conductivity, and the base material 11. And a mesh-like mesh layer 30 having light shielding properties, and when viewed from the normal direction of the base material 11, the mesh layer 30 is located outside the antenna layer 20 and a part thereof Is arranged inside the antenna layer 20. According to such an antenna 10, the antenna layer 20 does not appear to be locally installed, and the antenna layer 20 becomes inconspicuous. Thereby, the invisibility of the antenna layer 20 can be increased easily. In particular, the boundary between the antenna layer 20 and the mesh layer 30 becomes difficult to see, and the antenna layer 20 becomes extremely inconspicuous, and the invisibility can be effectively improved. Further, the function can be expanded by adding a function different from the antenna layer 20 to the mesh layer 30, for example, a function as an antenna for transmitting and receiving radio waves having different frequencies, a heating function in a defroster, and the like. it can.

  In the antenna 10 according to the present embodiment, the antenna layer 20 is formed in the same mesh pattern shape as that of the mesh layer 30. According to such an antenna 10, since the difference in transmittance between the antenna layer 20 and the mesh layer 30 can be suppressed, the invisibility can be effectively increased.

  Furthermore, in the antenna 10 according to the present embodiment, when viewed from the normal direction of the base material 11, the mesh layer is formed outside the antenna layer 20 in at least two of the four directions of the top, bottom, left, and right determined on the base material 11. 30 is located. According to such an antenna 10, the antenna layer 20 can be made inconspicuous by the mesh layer 30.

  Further, in the antenna 10 according to the present embodiment, the base material 11 is provided with an extraction electrode portion 13 that is electrically connected to a part of the outer peripheral portion of the antenna layer 20 and extends outward from the antenna layer 20. 30 is located so as to surround the entire outer peripheral portion of the antenna layer 20 except for the connection position of the extraction electrode portion 13. According to such an antenna 10, the antenna layer 20 is not clearly noticeable, so that invisibility can be reliably increased.

  Further, in the antenna 10 according to the present embodiment, at least one of the antenna conductor 21 and the mesh conductor 31 includes the main body layers 21a and 31a made of a metal material, and the base material 11 side and / or the main body layers 21a and 31a. Or the low reflective layers 21b and 31b made of copper nitride containing oxygen atoms at a depth of 5 nm or more from the surface, which are laminated on the opposite side of the substrate 11, and the film thickness of the low reflective layers 21b and 31b is The reflection Y value of the low reflection layers 21b and 31b is 30% or less. According to such an antenna 10, it is possible to suppress the reddish light from reaching the observer due to the metallic luster of copper by the low reflection layers 21b and 31b. Further, since the film thickness of the low reflection layers 21b and 31b is 10 nm to 60 nm and the reflection Y value of the low reflection layers 21b and 31b is 30% or less, preferably 27% or less, the antenna conductor 21 or the mesh conductor 31 It can suppress that visibility falls by reflected light of. Furthermore, since both the main body layers 21a and 31a and the low reflection layers 21b and 31b contain copper, the main body layers 21a and 31a and the low reflection layer 21b can be obtained by using an etchant that can selectively dissolve copper. 31b can be formed simultaneously. For this reason, the man-hour required in order to produce the antenna layer 20 and the mesh layer 30 can be made small.

  Furthermore, in the antenna 10 according to the present embodiment, the antenna layer 20 and the mesh layer 30 are provided at different positions in the normal direction, and when viewed from the normal direction, the antenna layer 20 and the mesh layer 30 are In the overlapping portion, the mesh pattern shape of the antenna layer 20 and the mesh pattern shape of the mesh layer 30 are arranged to coincide with each other. According to such an antenna 10, it is possible to suppress variations in light transmittance between the portion where the antenna layer 20 and the mesh layer 30 overlap and the other portion.

Furthermore, in the antenna 10 according to the present embodiment, the antenna layer 20 and the mesh layer 30 include copper as a main component, and are provided on one surface of the substrate 11 with the transparent adhesive layer 12 interposed therebetween. the ratio of the total light reflectance was measured in conformity with JIS Z 8722 of the transparent adhesive layer 12 side surface diffusion light reflectance for _{(R SCI) (R SCE)} (R SCE / R SCI) is 0.4 or less . According to such an antenna 10, since the surface of the transparent adhesive layer 12 has a shape that hardly scatters transmitted light, haze can be reduced.

  Various modifications can be made to the above-described embodiment. Hereinafter, modified examples will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above embodiment are used for the parts that can be configured in the same manner as in the above embodiment. A duplicate description is omitted. In addition, when it is clear that the operational effects obtained in the above-described embodiment can be obtained in the modified example, the description thereof may be omitted.

(Modification on the second surface side of the substrate)
8 and 9 correspond to the cross-sectional view of the antenna of FIG. 3, and are cross-sectional views of antennas of different examples. In the example shown in FIGS. 8 and 9, the first surface 11a side of the substrate 11 on which the antenna layer 20 is provided is not different from the embodiment shown in FIG. 3, but the base on which the mesh layer 30 is provided. The second surface 11b side of the material 11 is different from the embodiment shown in FIG.

  In the modification shown in FIG. 8, when the base material 11 is viewed from the normal direction, the mesh layer 30 is provided over the entire region where the antenna layer 20 is provided. That is, when the base material 11 is viewed from the normal direction, the overlapping portion R extends over the entire antenna layer 20. Even with such a configuration, the invisibility of the antenna layer 20 can be easily increased. Furthermore, when the mesh layer 30 is provided with a function different from that of the antenna layer 20, the function can be exhibited even in a region where the antenna layer 20 is provided. For example, when the mesh layer 30 has a function as a defroster, the region where the antenna layer 20 is provided can also be overheated.

In the modification shown in FIG. 9, the antenna 10 is provided with a mesh-like second antenna layer 40 having light shielding properties and conductivity on the second surface 11 b of the substrate 11. In particular, when the base material 11 is viewed from the normal direction, the second antenna layer 40 is provided in a portion where the mesh layer 30 is not provided in FIG. 3, that is, inside the antenna layer 20. Therefore, when viewed substrate 11 from the normal direction, the antenna layer 20 is not only overlaps a mesh layer 30 and the overlapping portion R _1, overlaps the second antenna layer 40 both overlap R _2. A gap G is provided between the second antenna layer 40 and the mesh layer 30. According to such a configuration, two antenna layers can be provided in a narrow region while increasing the invisibility of the antenna layer 20. In particular, if the antenna layer 20 and the second antenna layer 40 have the same mesh pattern shape and are formed so as to coincide with each other in the normal direction, the portion where the antenna layer 20 and the second antenna layer 40 overlap each other. It is possible to suppress the occurrence of shading.

(Modification in which a mesh layer is provided on the first surface side of the substrate)
10 to 13, the second mesh layer 50 is also provided on the first surface 11 a side of the base material 11. FIG. 10 is an enlarged plan view of the antenna corresponding to FIG. 11 to 13 are cross-sectional views taken along the line XI-XI in FIG. 10, and are cross-sectional views of antennas of different examples.

In the example shown in FIGS. 10 and 11, the antenna 10 is provided with a mesh-like second mesh layer 50 having a light shielding property on the first surface 11 a of the substrate 11. In particular, when the base material 11 is viewed from the normal direction, the second mesh layer 50 is provided in a portion where the antenna layer 20 is not provided in FIG. 3, that is, outside the antenna layer 20. Therefore, when viewed substrate 11 from the normal direction, the mesh layer 30 is not only overlap with the antenna layer 20 and the overlapping portion R _1, overlaps with the second mesh layer 50 both overlap R _2. A gap G is provided between the antenna layer 20 and the second mesh layer 50. Even with such a configuration, the invisibility of the antenna layer 20 can be easily increased. In particular, if the mesh layer 30 and the second mesh layer 50 have the same mesh pattern shape and are formed so as to coincide with each other in the normal direction, the mesh layer 30 and the second mesh layer 50 overlap each other. It is possible to suppress the occurrence of shading.

FIG. 12 shows the antenna 10 in which the second mesh layer 50 is provided also on the first surface 11 a side of the base material 11 in the example shown in FIG. 8. That is, when viewed substrate 11 from the normal direction, overlapping portion R ₁ of the mesh layer 30 and the antenna layer 20 is over the entire region where the antenna layer 20 is provided. Further, the mesh layer 30 and the second mesh layer 50, overlap in overlapping portion _{R 2.} Further, a gap G is provided between the antenna layer 20 and the second mesh layer 50. Even with such a configuration, the invisibility of the antenna layer 20 can be easily increased, and different functions can be provided in the same region.

FIG. 13 shows the antenna 10 in which the second mesh layer 50 is provided also on the first surface 11 a side of the base material 11 in the example shown in FIG. 9. That is, when viewed substrate 11 from the normal direction, the antenna layer 20 is not only overlaps a mesh layer 30 and the overlapping portion R _1, overlaps the second antenna layer 40 both overlap R _2. Further, the mesh layer 30 and the second mesh layer 50, overlap in overlapping portion _{R 3.} Further, a gap G ₁ is provided between the antenna layer 20 and the second mesh layer 50, and a gap G ₂ is provided between the second antenna layer 40 and the mesh layer 30. The gaps G ₁ and G ₂ are provided at different portions when the base material 11 is viewed from the normal direction. In such a configuration, two antenna layers can be provided in a small area while increasing the invisibility of the antenna layer 20. In particular, if the antenna layer 20 and the second antenna layer 40, and the mesh layer 30 and the second mesh layer 50 are formed in the same mesh pattern shape, the antenna layer 20, the second antenna layer 40, the mesh layer 30 and the second mesh layer 30 are formed. The invisibility of the 2 mesh layer 50 can be increased. Further, since the gaps G ₁ and G ₂ are provided in different portions, when the base material 11 is viewed from the normal direction, the gap G ₁ is in the mesh layer 30, and the gap G ₂ is in the antenna layer 20. Covered. Therefore, the gaps G ₁ and G ₂ are not visually recognized and are not conspicuous.

  In the modification in which the second antenna layer 40 and the second mesh layer 50 are provided, the second antenna layer 40 and the second mesh layer 50 have the same configuration as the antenna layer 20 and the mesh layer 30. May be. That is, the second antenna layer 40 includes a plurality of second antenna conductors 41, the plurality of antenna conductors 41 defines a second antenna opening region 42, and the second mesh layer 50 includes a plurality of second mesh conductors 51, The second mesh opening area 52 may be defined by a plurality of mesh conductors 51. Further, at least one of the second antenna conductor 41 and the second mesh conductor 51 is laminated on the base material 11 side and / or the base material 11 side opposite to the main body layer and the main body layer. And a low reflection layer made of copper nitride containing oxygen atoms at a depth of 5 nm or more from the surface. The film thickness of the low reflection layer is 10 nm to 60 nm, and the reflection Y value of the low reflection layer is 30 % Or less.

(Modification in which the pitch of the opening areas on the first surface side and the second surface side of the base material is shifted)
In the above-described embodiment, an example in which the patterns of the opening regions on the first surface 11a side and the second surface 11b side of the base material 11 coincide with each other is shown, but the pitch of the opening regions may be shifted by a half pitch. . FIG. 14 is an enlarged plan view of the antenna corresponding to FIG. 15 is a cross-sectional view of the antenna along the line XV-XV in FIG.

  In the example shown in FIGS. 14 and 15, the antenna 10 has the same layer configuration as the example of FIG. 12 described above, and the antenna layer 20, the mesh layer 30, and the second mesh layer 50 have the same mesh pattern. Although formed in a shape, the pitch of the opening regions 22 and 52 of the antenna layer 20 and the second mesh layer 50 provided on the first surface 11a side of the base material 11 is on the second surface 11b side of the base material 11. The pitch of the opening regions 32 of the provided mesh layer 30 is shifted by a half pitch. That is, in the portion where the antenna layer 20 and the second mesh layer 50 and the mesh layer 30 overlap, the mesh pattern shape on the first surface 11a of the substrate 11 and the mesh pattern shape on the second surface 11b are shifted by a half pitch. Are arranged. In particular, in the example shown in FIG. 14, when the base material 11 is viewed from the normal direction in the gap G between the antenna layer 20 and the second mesh layer 50, the antenna conductor 21 is extended to extend the second mesh conductor 51. The mesh conducting wire 31 is also provided so as to be connected to.

(Modification in which the antenna layer and the mesh layer are provided on the same surface of the substrate)
In the example shown in FIGS. 16 and 17, both the antenna layer 20 and the mesh layer 30 are provided on the first surface 11 a of the substrate 11. 16 is an enlarged plan view of the antenna corresponding to FIG. 2, and FIG. 17 is a cross-sectional view of the antenna along the line XVII-XVII in FIG.

  As shown in FIG. 16, a part of the mesh layer 30 extends inside the antenna layer 20. However, although the antenna layer 20 and the mesh layer 30 have the same mesh pattern shape, the arrangement of the patterns is slightly shifted, and the antenna layer 20 and the mesh layer 30 are not electrically connected. On the other hand, when the antenna 10 of the present modification is observed from a sufficiently long distance, the antenna layer 20 and the mesh layer 30 are observed as the same mesh pattern shape. Furthermore, a part of the mesh layer 30 extending inside the antenna layer 20 and the antenna layer 20 are observed as overlapping portions R when observed from a sufficiently distant place. Therefore, even in such a configuration, the invisibility of the antenna layer 20 can be easily increased. Moreover, since the antenna layer 20 and the mesh layer 30 are provided on the same surface of the base material 11, the antenna 10 can be manufactured thin.

(Modified example with variable opening area)
18 is a plan view of the antenna layer 20 of the antenna 10 according to the modified example in which the opening area is varied, FIG. 19 is an enlarged view of FIG. 18, and FIG. 20 is a general image display mechanism 5. FIG. As shown in FIGS. 18 and 19, in this modification, the antenna opening region 22 in the antenna layer 20 changes its shape without greatly disturbing the periodicity of the arrangement so as to vary the opening area. It has become. Although not shown, the mesh layer 30 is also the same. This modification differs from the above-described embodiment in this point.

In the display area of the image display mechanism 5 shown in FIG. 20, pixels P for forming an image are regularly arranged. The antenna 10 is also assumed to be installed on a film that covers the image display mechanism 5. In a general image display mechanism 5, pixels are arranged at a constant pitch both in the horizontal direction (direction d _x in FIG. 20) in the installation state of the image display mechanism 5 and in the direction d _y (for example, the vertical direction) orthogonal to the horizontal direction. P is arranged. In general, each pixel P includes a plurality of sub-pixels RP, GP, and BP as in the example illustrated in FIG. When the antenna 10 overlaps the image display mechanism 5 having the pixel arrangement, when the antenna layer 20 of the antenna 10 and the opening regions 22 and 32 of the mesh layer 30 are regularly arranged, the pixel P is regularly (periodically). There is a possibility that a striped pattern resulting from the pattern and the arrangement pattern of the opening regions 22 and 32 of the antenna layer 20 and the mesh layer 30, that is, moire, is visually recognized.

  In general, in a member having a mesh pattern, it has been considered that making the mesh pattern irregular, that is, breaking the periodicity of the pattern arrangement is effective for invisibility of moire. However, according to the study by the present inventors, the pattern of the antenna layer 20 and the mesh layer 30 is aperiodic to such an extent that the moire is sufficiently inconspicuous, that is, the opening regions 22 and 32 are irregularly arranged. Then, the moire can be made inconspicuous, but it has been found that the unevenness of density due to the density variation of the opening regions 22 and 32 becomes conspicuous instead. That is, it has been found that the moire reduction and the shading reduction are incompatible with each other. Until now, various measures for invisibility of such moire or shading unevenness have been studied, but none of them has effectively made both moire and shading unevenness inconspicuous.

  On the other hand, the inventors of the present invention have an opening area of the opening regions 22, 32, in other words, a region inside the plurality of conducting wires 21, 31 surrounded by the plurality of conducting wires 21, 31 that define the opening regions 22, 32. Focusing on the variation of the area, we conducted extensive research. As a result, the inventors of the present invention are able to make the moire inconspicuous very effectively by imposing restrictions on the variation of the opening area of the opening regions 22 and 32, and at the same time, the unevenness of the shade is extremely effective. It was found that both can be made inconspicuous. Such an effect simply performs pattern irregularization as moiré invisibility, while simply pattern regularization as shading unevenness, resulting in both moire and shading unevenness. It can be said that this is a remarkable effect that exceeds the predicted range from the state of the art that could not be made invisible. Hereinafter, a preferable distribution of the opening areas of the opening regions 22 and 32 in the antenna layer 20 and the mesh layer 30 will be described from the viewpoint of invisibility of both moire and shading unevenness.

First, it is preferable that the average value m of the aperture area of the aperture region 22 in the antenna layer 20 and the standard deviation σ of the area of the aperture region 22 satisfy the following formula (a).
3 ≦ (((m + 1.5σ) − (m−1.5σ)) / m) × 100 ≦ 20 (a)

  In addition, Formula (a) can also be described as 3 ≦ 3σ / m × 100 ≦ 20. When this formula (a) is satisfied, it is possible to effectively prevent the moire and the shading unevenness from being visually recognized due to the target antenna layer 20. Similarly, with respect to the mesh layer 30 as well, it is preferable to satisfy the above formula (a) when the average value m of the opening area of the opening region 32 and the standard deviation σ of the area of the opening region 32 are used.

Here, when the graph normal variable X of the standard normal distribution conforms to N (m, σ ² ), the probability that X is included in the range where the deviation from the average value m is ± 1.5 × σ or less is 86.64%. . Therefore, “m + 1.5σ” in the equation (a) is assumed to be one on the assumption that the distribution of the aperture areas 22 and 32 included in one target antenna layer 20 and mesh layer 30 follows a normal distribution. It means the maximum value among the opening area values within 86.64% centered on the average among all opening area values of all opening regions 22 and 32 included in one antenna layer 20 and mesh layer 30. become. Similarly, “m−1.5σ” in the equation (a) assumes that the distribution of the opening areas 22 and 32 included in one target antenna layer 20 and mesh layer 30 follows a normal distribution. , The minimum value among the opening area values within 86.64% centered on the average among all the opening area values of all the opening regions 22 and 32 included in one antenna layer 20 and the mesh layer 30. Will mean.

When the present inventor has conducted extensive research, when the formula (a) is satisfied, that is, for the average value (m) of “3σ” which is the difference between “m + 1.5σ” and “m−1.5σ”. When the ratio is 3% or more and 20% or less as a percentage, both moire and shading unevenness can be effectively made inconspicuous to such an extent that it does not become a problem in normal use in combination with the image display mechanism 5. It was. Further, when the following expression (b) was satisfied, it was made inconspicuous to the extent that neither moiré nor shading unevenness was felt in normal observation. Furthermore, when the following formula (c) is satisfied, even if the presence of moiré and shading unevenness is carefully observed, it is possible to make the moiré and shading unevenness invisible to such an extent that they cannot be visually recognized. .
4 ≦ (((m + 1.5σ) − (m−1.5σ)) / m) × 100 ≦ 15 (b)
5 ≦ (((m + 1.5σ) − (m−1.5σ)) / m) × 100 ≦ 10 (c)

Furthermore, as a result of repeated studies by the inventors of the present invention, when the following equation (d) is satisfied, it should be made inconspicuous to the extent that neither moiré nor shading is felt in normal observation. When the following equation (e) is satisfied, even if the presence of moiré shading is carefully observed, it can be made invisible to the extent that both moiré and shading unevenness cannot be visually recognized. It was.
4 ≦ (((m + 2σ) − (m−2σ)) / m) × 100 ≦ 25 (d)
5 ≦ (((m + 2σ) − (m−2σ)) / m) × 100 ≦ 15 (e)

Here, when the graph normal variable X of the standard normal distribution follows N (m, σ ² ), the probability that X is included in the range where the deviation from the average value m is ± 2 × σ or less is 95.44%. That is, in the formula (d) and the formula (e), the ratio of the opening regions 22 and 32 in which the opening area values of all the opening regions 22 and 32 should be considered is increased as compared with the formulas (a) to (c). . Therefore, it is possible to control the overall distribution of the opening areas of the opening regions 22 and 32 included in one antenna layer 20 and the mesh layer 30 with higher accuracy. For this reason, the ratio in the formulas (d) and (e) represented by “((m + 2σ) − (m−2σ)) / m) × 100” represents “((m + 1.5σ) − (m It is considered that the same effect can be ensured even if the ratio is set larger than the ratio in the formulas (b) and (c) represented by −1.5σ)) / m) × 100 ”.

  In addition, the opening area of each opening area | region 22 and 32 contained in the one antenna layer 20 and the mesh layer 30 can be specified based on the image data acquired by an image processing apparatus as an example. For example, first, the antenna layer 20 and the mesh layer 30 are taken with a camera-equipped microscope from the normal direction of the film to obtain an image in which the opening region is black and the mesh portion is white. Next, the illumination unevenness is removed from the image by a spatial frequency high-pass filter, and further binarized using a discriminant analysis method (for example, binarization processing by Otsu). Thereafter, the number of pixels in the closed region is counted for the binarized image, and the number of pixels is converted to the actual size. The conversion to the actual size can be calculated from the image resolution.

  Returning to FIG. 18, an example of the antenna layer 20 in the present modification is shown. The pattern of the antenna layer 20 includes a group for generating the antenna layer 20 according to the present modification example, which is formed of a plurality of line segments 61 extending between the two intersections 63 and defining an opening region (opening) 62. On the basis of the reference mesh pattern 60 (see FIG. 19), the arrangement period of the reference mesh pattern is determined so as to be appropriately irregular. More specifically, the pattern of the antenna layer 20 is based on the reference mesh pattern 60 in which the opening regions 62 are regularly arranged, in other words, the opening regions 62 are arranged with periodicity. The shape of the opening region 62 is changed so that the moire can be sufficiently invisible while maintaining the uniformity of the arrangement position of the opening region 62 so as not to cause unevenness of light and shade. It is determined by varying the area.

  In this modification, the antenna layer 20 and the mesh layer 30 are determined based on the reference mesh pattern 60 shown in FIG.

  Below, an example of the determination method of the pattern of the antenna layer 20 and the mesh layer 30 in this modification is demonstrated. In the method described below, a step of determining a reference mesh pattern 60 formed from a plurality of line segments 61 extending between two intersection points 63 and defining an open region 62, and the intersection point 63 of the reference mesh pattern 60 is determined. Based on the step of determining the positions of the branch points 23 and 33 in the antenna layer 20 and the mesh layer 30 based on the line segment 61 of the determined branch points 23 and 33 and the reference mesh pattern 60, the antenna conductor 21 and the mesh conductor 31 are determined. And determining the position of. Hereinafter, each step will be described in order.

  First, in the step of determining the reference mesh pattern 60, a regular pattern that is the basis of the antenna layer 20 and the mesh layer 30, that is, the reference mesh pattern 60 is determined. The reference mesh pattern 60 determined here is formed of a plurality of line segments 61 that extend between two intersections 63 and define an open region 62. In the reference mesh pattern 60, the opening regions 62 having a predetermined shape are regularly arranged in the first direction d1 and the second direction d2 similar to the direction described in the embodiment. The reference mesh pattern 60 may include a plurality of types of opening regions 62, and the various types of opening regions 62 may be regularly arranged in two or more directions that intersect.

As shown in FIG. 19, in the illustrated reference mesh pattern 60, a constant rectangular opening region 62 is a pattern that is spread without gaps. The opening regions 62 are arranged at a constant pitch in the first direction d ₁ and the second direction d ₂ that intersect each other. In particular, the illustrated reference mesh pattern 60 includes a plurality of first straight lines 60a each extending linearly in the first direction d1 and arranged at a constant pitch P1 in a direction orthogonal to the first direction d1, respectively. It is defined but by a second straight line 60b group arranged at the same predetermined pitch P2 and the predetermined pitch P1 in the direction and perpendicular to the second direction d ₂ extends linearly in the second direction d ₂ . As a result, all the opening regions 62 included in the reference mesh pattern 60 are formed in the same quadrangular shape, particularly, a rhombus shape.

Incidentally, in general, the moire caused by interference between the pixel arrangement and the antenna layer 20 and mesh layer 30 of the image display mechanism 5 from the viewpoint of invisible, the arrangement direction of the pixels in the image display mechanism 5 d _x, to d _y, antenna The arrangement direction of the opening regions 22 and 32 of the layer 20 and the mesh layer 30 is preferably inclined. On the other hand, when the present inventors have repeated experiments, in order to invisible moire with square lattice arrayed pixels P shown in FIG. 20, further, even for diagonal d _o of the pixel, the aperture It was effective to incline the arrangement direction of the regions 22 and 32. This is because, as shown in FIG. 20, light-shielding portions in which the thick portions 5a1 of the light-shielding portions (for example, black matrix) 5a that define the pixels P are arranged at positions on the diagonal line of the pixels P, and are arranged at regular intervals. This is probably because moire between the thick portion 5a1 of 5a and the opening regions 22 and 32 is likely to occur.

A general pixel P arranged in a square lattice has a square shape in plan view. When using such a pixel P, the diagonal _{d o} is, 45 ° inclined with respect to the pixel arrangement direction _d x, _{d y.} Then, when the present inventors have confirmed, in order to invisible moire between the pixel P of a square shape, the arrangement direction of the aperture region 22 and 32, the pixel arrangement direction d _{x orthogonal,} one of d _y d _The angle formed with respect to _x is preferably 30 ° or more and 40 ° or less, more preferably 33 ° or more and 37 ° or less, and most preferably 35 °. In other words, in order to invisible moire between the pixel P of square shape, angular arrangement direction of the opening area 22 and 32, which forms with the other d _y of SEQ direction d _x, d _y of pixels perpendicular Is preferably 50 ° or more and 60 ° or less, more preferably 53 ° or more and 57 ° or less, and most preferably 55 °.

On the other hand, in the pattern determination method of the antenna layer 20 and the mesh layer 30 described here, the opening regions 22 and 32 of the antenna layer 20 and the mesh layer 30 generally follow the arrangement direction of the opening regions 62 of the reference mesh pattern 60. Become. The arrangement direction of the opening area 62 in the reference mesh pattern 60 becomes the first direction _{d 1} and the second direction _{d 2.} Therefore, the first direction _{d 1} and the second direction _{d 2} determining the orientation of the opening region 62 included in the reference mesh pattern 60, the arrangement direction _d x of the pixel P that is perpendicular, to one in which _{d x} of _{d y} The angle is preferably 30 ° or more and 40 ° or less, more preferably 33 ° or more and 37 ° or less, and the angles θ _1x and θ _2x of 35 ° may be formed as shown in FIG. Most preferred. The angle θ _x formed by the first direction d ₁ and the second direction d ₂ with respect to each other is preferably 60 ° or more and 80 ° or less, more preferably 66 ° or more and 74 ° or less, as shown in FIG. Most preferably, the angle is 70 °. Further, the first direction d ₁ and the second direction d ₂ determining the orientation of the opening region 62 included in the reference mesh pattern 60, 50 ° to 60 ° with respect to the other d _y of the pixel arrangement direction orthogonal Is more preferable, and an angle between 53 ° and 57 ° is more preferable, and it is most preferable that the angles θ _1y and θ _2y are 55 ° as shown in FIG.

  Next, the process of determining the positions of the branch points 23 and 33 based on the intersection 63 of the reference mesh pattern 60 will be described. In this step, the position of one branch point 23 is determined from one intersection 63 of the reference mesh pattern 60. Specifically, each branch point 23 is arranged on the corresponding intersection 63 of the reference mesh pattern 60 or at a position shifted from the corresponding intersection 63 by a length equal to or less than a predetermined length. At this time, the shapes of the opening regions 22 and 32 of the antenna layer 20 and the mesh layer 30 finally obtained are determined by irregularly determining the amount of deviation and the direction of deviation from the corresponding intersection 63 of each branch point 23. It is not constant, and moire can be effectively inconspicuous. In addition, when the deviation amount selected irregularly becomes 0, the branch points 23 and 33 may be located on the corresponding intersection 63. Further, by providing a restriction on the amount of deviation from the corresponding intersection 63 of each of the branch points 23 and 33, the conditions of the above-described equations (a) to (e) are satisfied and finally determined. The regularity or uniformity to the extent that shading unevenness can be avoided is ensured in the pattern of the antenna layer 20 and the mesh layer 30 to be formed.

It should be noted that the amount of deviation of each branch point 23, 33 from the corresponding intersection 63 is less than half the arrangement pitch of the opening regions 62 in order to avoid the conductors 21, 31 from coming into contact with other conductors. Is preferred. This is because if one conductor 21, 31 overlaps with another conductor 21, 31, the portion is visually recognized and may cause uneven shading. Specifically, in order to avoid that the wire 21, 31 is in contact with other conductors 21 and 31, the deviation amount from the corresponding intersection 63 of each branch point 23 and 33, orthogonal to the first direction _{d 1} less than half of the first straight line 60a group arrangement pitch P1 in the direction, and may be less than half of the second straight line 60b groups the arrangement pitch P2 in a direction perpendicular to the second direction d _2.

Further, instead of determining both the amount of deviation from the corresponding intersection 63 and the direction of deviation for each branch point 23, 33, each branch point 23, 33 is preset from the corresponding intersection 63. The deviation amounts in the two directions may be determined respectively. As an example, the arrangement direction _d x of the pixel P of the image display device 5, the deviation amount [delta] _x of the corresponding intersection 63 to _{d y,} [delta] _y (see FIG. 19), then determined for each branch point 23 and 33 You may make it go. In this example, below a certain percentage of arrangement pitch p _x of the opening region 62 along one of the arrangement direction d _x of the pixel P (e.g., 10% or less, preferably 5% or less) is to become so shift amount [delta] _x determined so as to be, and, below a certain percentage of the arrangement pitch p _y open area 62 along the other arrangement direction d _y of the pixel P (e.g., 14% or less, preferably 7% or less) amount deviation such that δ _By determining _y , a restriction may be imposed on the amount of deviation of the branch point 23 from the corresponding intersection 63.

  Next, the process of determining the positions of the conducting wires 21 and 31 will be described. When the positions of the branch points 23 and 33 in the antenna layer 20 and the mesh layer 30 are determined as described above, the positions of the conductors 21 and 31 are then determined based on the determined branch points 23 and 33. Specifically, the positions of the conductors 21 and 31 so as to extend between the two branch points 23 and 33 respectively corresponding to the two intersections 63 located at both ends of a certain line segment 61 of the reference mesh pattern 60. To decide. The path of the conducting wires 21 and 31 between the two branch points 23 and 33 may be a straight line, a curved line, a broken line, or a combination of a straight line and a curved line. Also good. Moreover, the line width of the conducting wires 21 and 31 can be set to 0.2 μm or more and 2 μm or less as described above, or may be a thickness outside this range.

  In this way, the antenna layer 20 and the mesh layer 30 are formed. Since the positions of the branch points 23 and 33 of the antenna layer 20 and the mesh layer 30 are determined based on the position of the intersection 63 of the reference mesh pattern 60 having regularity, the obtained antenna layer 20 and mesh layer 30 are obtained. As a result, the opening regions 22 and 32 are uniformly dispersed to a certain extent, thereby suppressing the occurrence of shading unevenness. However, the positions of the branch points 23 and 33 are deviated from the positions of the corresponding intersection points 63 by an amount within a predetermined range selected irregularly. Therefore, the obtained antenna layer 20 and mesh layer 30 lose the regularity or regularity of the shape or opening area of the opening regions 22 and 32, and can also avoid problems due to moire.

  The antenna layer 20 and the mesh layer 30 whose patterns are determined as described above are produced on the base material 11 by patterning a copper foil or the like formed on the base material 11 using a photolithography technique. obtain.

In the modification as described above, the average value m of the opening areas 22 and 32 included in the antenna layer 20 and the mesh layer 30 and the standard deviation σ of the area of the opening areas 22 and 32 are expressed by Equation (a). It comes to meet. As a result, it is possible to effectively prevent the moire and shading unevenness from being visually recognized due to the target antenna layer 20 and mesh layer 30.
3 ≦ (((m + 1.5σ) − (m−1.5σ)) / m) × 100 ≦ 20 (a)

Further, the average value m of the opening areas 22 and 32 included in the antenna layer 20 and the mesh layer 30 and the standard deviation σ of the areas of the opening areas 22 and 32 satisfy the formula (b) or the formula (d). In such a case, in normal observation, it can be made inconspicuous to the extent that neither moiré nor shading unevenness is felt, and further satisfies formula (c) or formula (e). In such a case, even if the presence of moire and shading unevenness is carefully observed, it can be made invisible to such an extent that both moire and shading unevenness cannot be visually recognized.
4 ≦ (((m + 1.5σ) − (m−1.5σ)) / m) × 100 ≦ 15 (b)
5 ≦ (((m + 1.5σ) − (m−1.5σ)) / m) × 100 ≦ 10 (c)
4 ≦ (((m + 2σ) − (m−2σ)) / m) × 100 ≦ 25 (d)
5 ≦ (((m + 2σ) − (m−2σ)) / m) × 100 ≦ 10 (e)

  In addition, although several modifications with respect to embodiment mentioned above were demonstrated above, naturally, it is also possible to apply combining several modifications suitably.

DESCRIPTION OF SYMBOLS 10 Antenna 11 Base material 11a 1st surface 11b 2nd surface 12 Transparent adhesive layer 13 Extraction electrode part 20 Antenna layer 20a Smooth surface 20b Non-smooth surface 21 Antenna conductor 21a Main body layer 21b Low reflection layer 22 Antenna opening 23 Branch point 30 Mesh Layer 30a Smooth surface 30b Non-smooth surface 31 Mesh conductor 31a Body layer 31b Low reflection layer 32 Mesh opening 33 Branch point 40 Second antenna layer 50 Second mesh layer 60 Reference mesh pattern 61 Line segment 62 Opening region 63 Intersection R Overlapping part G Clearance FL1 contour line

Claims (16)

A base material formed into a sheet,
A mesh-like antenna layer provided on the base material and having light shielding properties and conductivity;
A mesh-like mesh layer provided on the substrate and having a light shielding property,
When viewed from the normal direction of the base material, the mesh layer is located outside the antenna layer, and a part of the mesh layer is arranged inside the antenna layer.   The antenna according to claim 1, wherein the antenna layer is formed in the same mesh pattern shape as the mesh layer.   The mesh layer is located outside the antenna layer in at least two directions of four directions (up, down, left, and right) determined on the base material when viewed from the normal direction of the base material. 2. The antenna according to 2. The substrate is provided with an extraction electrode portion that is electrically connected to a part of the outer peripheral portion of the antenna layer and extends outward from the antenna layer,
The antenna according to any one of claims 1 to 3, wherein the mesh layer is positioned so as to surround the entire region of the outer peripheral portion excluding a connection position of the extraction electrode portion in the antenna layer.   The part of the mesh layer disposed inside the antenna layer extends from the portion of the mesh layer located outside the antenna layer to the inside of the antenna layer. The antenna as described in any one.   The antenna according to any one of claims 1 to 5, wherein the antenna layer is provided on one surface of the base material, and the mesh layer is provided on the other surface of the base material. The antenna layer includes a plurality of antenna conductors arranged in a mesh pattern on the base material, and defines a plurality of antenna opening areas by the plurality of antenna conductors,
The antenna according to claim 1, wherein the mesh layer includes a plurality of mesh conductors arranged in a mesh pattern on the base material, and defines a plurality of mesh opening regions by the plurality of mesh conductors. At least one of the antenna conductor and the mesh conductor is
A body layer made of a metal material;
A low reflection layer made of copper nitride containing oxygen atoms at a depth of 5 nm or more from the surface, laminated on the base material side and / or on the opposite side of the base material with respect to the main body layer;
Including
The film thickness of the low reflection layer is 10 nm to 60 nm,
The antenna according to claim 7, wherein the reflection Y value of the low reflection layer is 30% or less. The antenna according to claim 7 or 8, wherein an average value m of the area of the antenna opening area in the antenna layer and a standard deviation σ of the area of the antenna opening area satisfy the following expression.
3 ≦ 3σ / m × 100 ≦ 20 The antenna according to claim 9, wherein an average value m of the area of the mesh opening area in the mesh layer and a standard deviation σ of the area of the mesh opening area satisfy the following expression.
3 ≦ 3σ / m × 100 ≦ 20 The antenna layer and the mesh layer are provided at different positions in the normal direction,
When viewed from the normal direction, the mesh pattern shape of the antenna layer and the mesh pattern shape of the mesh layer are arranged to coincide with each other in a portion where the antenna layer and the mesh layer overlap. Item 11. The antenna according to any one of Items 1 to 10.   The antenna according to claim 1, wherein the base material is transparent. The antenna layer includes copper as a main component, and is provided on one surface of the base material via a transparent adhesive layer,
Wherein the ratio of the total light reflectance was measured in conformity with JIS Z 8722 of the transparent adhesive layer side surface of the antenna layer _{(R SCI)} diffuse light reflectance for _{(R SCE) (R SCE /} R SCI) is 0. The antenna according to claim 12, wherein the antenna is 4 or less. The mesh layer contains copper as a main component, and is provided on one surface of the base material via a transparent adhesive layer,
Wherein the ratio of the total light reflectance was measured in conformity with JIS Z 8722 of the transparent adhesive layer side surface of the mesh layer _{(R SCI)} diffuse light reflectance for _{(R SCE) (R SCE /} R SCI) is 0. The antenna according to claim 12 or 13, which is 4 or less. In the base material, provided in a position different from the antenna layer in the normal direction, further comprising a mesh-like second antenna layer having light shielding properties and conductivity,
The antenna according to claim 1, wherein the second antenna layer is provided inside the antenna layer when the base material is viewed from a normal direction.   The antenna according to claim 15, wherein the antenna layer is formed in the same mesh pattern shape as the second antenna layer.

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