JP2017175540A - antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna which enables the invisibility of an antenna layer provided at a base material to be easily improved.SOLUTION: An antenna 1 according to an embodiment includes: a base material 2 formed into a sheet shape; a net-like antenna layer 10 provided at the base material 2 and having light blocking effect and conductivity; and a net-like mesh layer 100 provided at the base material 2 and having light blocking effect. When the base material 2 is viewed from a normal direction of the base material 2, the mesh layer 100 is positioned at an outer side of the antenna layer 10 forming a gap G between itself and the antenna layer 10.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 inventor has previously proposed an antenna in which an antenna layer provided on a transparent substrate is formed in a mesh shape (see Patent Documents 1 and 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 includes a base material formed in a sheet shape, a mesh-like antenna layer provided on the base material and having light shielding properties and conductivity, and a mesh having a light shielding property provided on the base material. And when the base material is viewed from the normal direction of the base material, the mesh layer is positioned outside the antenna layer with a gap with respect to the antenna layer. Yes.

  The antenna layer and the mesh layer may be formed in the same mesh pattern shape.

  The antenna layer and the mesh layer may be provided on the same plane.

  When the base material is viewed from the normal direction of the base material, even if the mesh layer is located outside the antenna layer in at least two of the four directions of up, down, left, and right determined on the base material Good.

  The substrate is provided with an extraction electrode portion that is electrically connected to a part of an outer peripheral portion of the antenna layer and extends outward from the antenna layer, and the mesh layer is formed of the extraction electrode portion of the antenna layer. You may position so that the whole region of the said outer peripheral part except a connection position may be surrounded.

  The gap between the mesh layer and the antenna layer may be 10 μm or more and 300 μm or less.

  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 regions by the plurality of antenna conductor wires, and the mesh layer is meshed on the base material A plurality of mesh conducting wires may be included, and a plurality of mesh opening regions may be defined by the plurality of mesh conducting wires.

  The mesh layer may be positioned with a gap with respect to a contour line defined by connecting ends of the plurality of antenna conductors positioned on the outermost periphery in the antenna layer with straight lines.

  At least one of the antenna layer and the mesh layer is a main body layer made of a metal material, and 5 nm from the surface laminated on the base material side and / or the reverse side of the base material with respect to the main body layer. A low reflection layer made of copper nitride containing oxygen atoms at the above depth, and 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. There may be.

  The mesh layer may be arranged so that the mesh conductor extends on an extension line to the mesh layer side of the antenna conductor whose end is located on the outermost periphery of the antenna layer.

The average value m of the area of the antenna opening area in the antenna layer and the standard deviation σ of the area of the antenna opening area may satisfy the following expression.
3 ≦ 3σ / m × 100 ≦ 20

The average value m of the area of the mesh opening area in the mesh layer and the standard deviation σ of the area of the mesh opening area may satisfy the following expression.
3 ≦ 3σ / m × 100 ≦ 20

  The substrate may be transparent.

The antenna layer contains copper as a main component, is provided on one surface of the base material via a transparent adhesive layer, and is measured according to JIS Z 8722 on the surface of the antenna layer on the transparent adhesive layer side. The ratio (R _SCE / R _SCI ) of the diffused light reflectance (R _SCE ) to the total light reflectance (R _SCI ) may be 0.4 or less.

The mesh layer contains copper as a main component, is provided on one surface of the base material via a transparent adhesive layer, and is measured according to JIS Z 8722 on the transparent adhesive layer side surface of the mesh layer. The ratio (R _SCE / R _SCI ) of the diffused light reflectance (R _SCE ) to the total light reflectance (R _SCI ) may be 0.4 or less.

  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 a region indicated by II in FIG. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 shows a mobile phone to which the antenna shown in FIG. 1 is applied. FIG. 6 is a diagram showing an automobile to which the antenna shown in FIG. 1 is applied. FIG. 7 is a diagram showing a building to which the antenna shown in FIG. 1 is applied. FIG. 8 is a diagram showing an RFID tag to which the antenna shown in FIG. 1 is applied. FIG. 9 is a plan view of an antenna according to the first modification. 10 is a cross-sectional view taken along line XX of FIG. FIG. 11 is a plan view of an antenna according to the second modification. FIG. 12 is a plan view of an antenna according to the third modification. 13 is a cross-sectional view taken along line XIII-XIII in FIG. FIG. 14 is a plan view of an antenna layer of an antenna according to Modification 4. FIG. 15 is an enlarged view of FIG. FIG. 16 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 1 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 the line III-III in FIG. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. As shown in FIGS. 1 to 4, the antenna 1 according to the present embodiment is a so-called transparent antenna, which is formed in a sheet shape and is provided on the transparent base material 2 and the base material 2. A pair of mesh-like antenna layers 10 having a property and a mesh-like mesh layer 100 provided on the base material 2 and having at least a light shielding property are provided.

  The illustrated antenna 1 is configured as a half-wave dipole antenna for radio wave transmission as an example. The base material 2 is provided with an extraction electrode portion 11 that is electrically connected to a part of the outer peripheral portion of each of the pair of antenna layers 10 and extends outward from the antenna layer 10. Each antenna layer 10 is electrically connected to a common power feeding unit 12 via a corresponding extraction electrode unit 11 and external wiring.

  The power supply unit 12 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 1 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 12.

  In the half-wave dipole antenna, when the frequency of a radio wave to be transmitted or received is 2.45 GHz, the wavelength is about 122.4 mm. In this case, since the length (L1 + L2) of the antenna layer 10 shown in FIG. 1 is ½ the wavelength, it is about 61.2 mm, and the length of one antenna layer 10 is about 30.6 mm. In addition, although the dimension of the width | variety shown by E in the figure of the antenna layer 10 is not specifically limited, For example, about 5-50 mm may be sufficient.

(Layer structure)
With reference to FIG.3 and FIG.4, in this Embodiment, the base material 2 is comprised with the member of the single layer which has the 1st surface 2a and the 2nd surface 2b which mutually oppose, on the 1st surface 2a of the base material 2 Further, the antenna layer 10, the extraction electrode portion 11, and the mesh layer 100 are provided via the transparent adhesive layer 3. In the present embodiment, the antenna layer 10 includes a main body layer 21 made of a metal material, and a low reflection layer 22 made of copper nitride laminated on the opposite side of the base material 2 with respect to the main body layer 21. Contains. Similarly, the mesh layer 100 includes a main body layer 121 made of a metal material, and a low reflection layer 122 made of copper nitride laminated on the side opposite to the base material 2 side with respect to the main body layer 121.

  Moreover, in this Embodiment, in the antenna layer 10, the surface by the side of the base material 2 (surface by the side of the transparent adhesive layer 3) becomes the smooth surface 10a with low light scattering property, and is the opposite side to the base material 2 side. Is a non-smooth surface 10b. Similarly, in the mesh layer 100, the surface on the base material 2 side (surface on the transparent adhesive layer 3 side) is a smooth surface 100a having a low light scattering property, and the surface opposite to the base material 2 side is non-surface. It is a smooth surface 10b. 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.

  3 and 4, the antenna layer 10 and the mesh layer 100 are exposed to the outside, but the antenna layer 10 and the mesh layer 100 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 concavo-convex surface of the antenna layer 10 and the mesh layer 100 on the substrate 2 by coating or the like. 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 substrate 2 is a single layer, but the substrate 2 may have a multilayer structure including a plurality of layers. The antenna layer 10 and the mesh layer 100 have a multilayer structure, but may have a single layer structure. As will be described later, the low reflection layers 22 and 122 are provided to reduce the reflectance, but a blackening layer may be used instead of the low reflection layers 22 and 122. Moreover, although the surface of the antenna layer 10 and the mesh layer 100 on the base material 2 side is a smooth surface and the opposite surface is a non-smooth surface, both surfaces may be smooth surfaces. However, the surfaces on both sides may be non-smooth surfaces. Hereinafter, each component of the antenna 1 will be described in detail.

(Base material)
As the base material 2, 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 ensure visibility in the antenna 1, the higher the transparency of the base material 2, the better. In this case, it is desirable that the base material 2 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 2 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 2 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 2 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 2 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 2 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 2 is preferably made of a flexible resin film or plate in view of good manufacturing processability and reduced weight and price. Moreover, in the base material 2 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 2 may be opaque.

(Transparent adhesive layer)
The type and the like of the transparent adhesive layer 3 are particularly limited as long as the transparent adhesive layer 3 can bond the antenna layer 10 and the mesh layer 100 to the base material 2 and has sufficient transparency in the present embodiment. It is not a thing. However, in the present embodiment, after the antenna layer 10 and the mesh layer 100 are bonded to the metal foil and the base material 2 via the transparent adhesive layer 3, the metal foil is patterned by etching. It is preferable that the transparent adhesive layer 3 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 3 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 3 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 2 and the antenna layer 10 and the mesh layer 100 can be firmly bonded, and the base material 2 is an etching solution such as iron oxide in the etching for forming the antenna layer 10 and the mesh layer 100. 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 3 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 2, and also 1.48-1. It is preferable to be within the range of 52.

(Antenna layer)
Next, the antenna layer 10 will be described. Referring to FIG. 2, the antenna layer 10 includes a plurality of antenna conductors 44 arranged in a mesh pattern on the first surface 2 a of the substrate 2, and a plurality of antenna opening regions 46 are defined by the plurality of antenna conductors 44. doing. In the present embodiment, the antenna lead wire 44 means a linear portion that extends between the two branch points 47 at the branch points 47 scattered in the antenna layer 10 and defines the antenna opening region 46. Yes.

  The antenna layer 10 in the present embodiment has a mesh pattern shape in which a certain rectangular antenna opening region 46 is spread without gaps. Specifically, the antenna opening regions 46 are arranged at a constant pitch in a first direction d1 and a second direction d2 that intersect each other. That is, the antenna opening region 46 includes a plurality of antenna conductors 44 each extending linearly in the first direction D1 and arranged at a constant pitch P1 in a direction orthogonal to the first direction d1, and each in the second direction D2. It is defined by a plurality of antenna conductors 44 extending in a straight line and arranged at a constant pitch P2 that is the same as the constant pitch P1 in a direction orthogonal to the second direction d2. As a result, the antenna opening regions 46 included in the illustrated antenna layer 10 are all formed in the same quadrangular shape, particularly 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 10 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 44 located on the outermost periphery in the antenna layer 10 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 conductors 44 located on the outermost periphery sequentially with straight lines. In the present embodiment, the antenna layer 10 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 10 (antenna conductor 44) in the present embodiment has the main body layer 21 and the low reflection layer 22 made of copper nitride, and the low reflection layer 22 is made of copper nitride. Therefore, although copper is included as a main component, the main body layer 21 also includes copper as a main component. Therefore, the antenna layer 10 contains copper as a main component as a whole. However, the material of the antenna conductor 44 is not limited to copper, and may be formed of, for example, gold, silver, aluminum, or the like.

  The thickness of the antenna layer 10 may be appropriately selected from the viewpoints of high conductivity, processability, mechanical strength, etc., 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 antenna layer 10 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 10 is formed in a mesh pattern shape in which the rectangular antenna opening regions 46 are regularly arranged. The mesh pattern shape of the antenna layer 10 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 100 will be described. Referring to FIG. 2, like the antenna layer 10, the mesh layer 100 includes a plurality of mesh conductors 144 arranged in a mesh pattern on the first surface 2 a of the substrate 2, and a plurality of mesh conductors 144 are used to form a plurality of mesh conductors 144. A mesh opening region 146 is defined. The mesh conducting wire 144 means a linear portion that extends between the two branch points 147 at the branch points 147 scattered in the mesh layer 100 and defines the mesh opening region 146.

  As shown in the plan views of FIGS. 1 and 2, the mesh layer 100 in the present embodiment has a gap with respect to the antenna layer 10 when the base material 2 is viewed in a plan view from the normal direction of the base material 2. G is located outside the antenna layer 10. Further, as shown in FIG. 2, the mesh layer 100 in the present embodiment is formed in the same mesh pattern shape as the antenna layer 10, and the mesh opening region 146 having a certain rectangular shape is laid without gaps. It has a pattern shape. Accordingly, the mesh opening regions 146 are arranged at a constant pitch in the first direction d1 and the second direction d2 that intersect each other. That is, the mesh opening region 146 includes a plurality of mesh conductors 144 each extending linearly in the first direction D1 and arranged at a constant pitch P1 in a direction orthogonal to the first direction d1, and each mesh opening region 146 in the second direction D2. The plurality of mesh conductive wires 144 extend linearly and are arranged at a constant pitch P2 that is the same as the constant pitch P1 in a direction orthogonal to the second direction d2. As a result, the mesh opening regions 146 included in the illustrated mesh layer 100 are also all formed in the same quadrangular shape, particularly a rhombus shape.

  As described above, the mesh layer 100 (mesh conductor 144) in the present embodiment also includes the main body layer 121 and the low reflection layer 122 made of copper nitride, and the low reflection layer 122 is copper nitride. Therefore, although copper is included as a main component, the main body layer 121 also includes copper as a main component. Therefore, the mesh layer 100 contains copper as a main component as a whole. In addition, the material of the mesh conducting wire 144 is not limited to copper, and may be formed of, for example, gold, silver, aluminum, or the like. The mesh layer 100 may be formed of a material different from that of the antenna layer 10, for example, a substance having an insulating property, or may be formed of a resin or the like.

  The mesh layer 100 in the present embodiment does not perform a desired function in the antenna or the defroster by conducting, but may be configured to be able to perform a desired function in the antenna or the defroster. Also good. The thickness of the mesh layer 100 may be appropriately selected from the viewpoints of processability, mechanical strength, high conductivity when functioning in a defroster or an antenna, depending on the material. In order to suppress and increase invisibility, the thickness is preferably the same as that of the antenna layer 10. Therefore, the thickness of the mesh layer 100 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 100 is more preferably 1 μm or more and 3 μm or less.

  Further, in the present embodiment, the mesh layer 100 is formed in a mesh pattern shape in which square-shaped mesh opening regions 146 are regularly arranged. The mesh pattern shape of the mesh layer 100 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 100 is preferably formed in the same mesh pattern shape as the antenna layer 10.

(Positional relationship between antenna layer and mesh layer)
Hereinafter, the positional relationship between the antenna layer 10 and the mesh layer 100 will be described in detail. As described above, when the base material 2 is viewed from the normal direction of the base material 2, the mesh layer 100 is located outside the antenna layer 10 with a gap G with respect to the antenna layer 10. In the example, the outline is formed in a rectangular shape.

  Specifically, as shown in FIG. 2, the mesh layer 100 in the present embodiment is positioned so as to surround the entire outer peripheral portion except for the connection position of the extraction electrode portion 11 in each of the pair of antenna layers 10, and The gap G is located with respect to the above-described contour FL1 that defines the external shape of the antenna layer 10. Here, the gap G means a gap in a direction orthogonal to the contour line FL1. In the illustrated example, the mesh layer 100 and the antenna layer 10 are parallel to each other.

  Further, in the present embodiment, as shown in FIG. 2, when an extension line EL to the mesh layer 100 side of the antenna conductor 44 whose end is located on the outermost periphery of the antenna layer 10 is extended, this extension line The mesh layer 100 is disposed so that the mesh conductor 144 extends on the EL. According to such an arrangement, it is possible to suppress variation in light transmittance around the boundary between the antenna layer 10 and the mesh layer 100.

  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. Then, in order to solve this problem, the antenna layer is fulfilling the intended function of the antenna, but the antenna layer is not visible as being locally installed. The different mesh layers 100 are arranged so as to be positioned close to each other with a gap G outside the antenna layer 10. According to such a configuration, only by providing the mesh layer 100 outside the antenna layer 10, the antenna layer 10 does not appear to be locally installed and the antenna layer 10 becomes inconspicuous. Invisibility can be easily increased.

  The gap G between the mesh layer 100 and the antenna layer 10 is preferably 10 μm or more and 300 μm or less. When the gap G is excessively narrow, there is a risk that the antenna layer 10 is energized with the mesh layer 100 and the appropriate performance of the antenna cannot be satisfied. When the gap G is excessively large, the presence of the antenna layer 10 is conspicuous. The inventor of the present invention has confirmed that the above-mentioned range is preferable as a value that achieves both ensuring invisibility and ensuring appropriate performance of the antenna layer 10 through intensive studies.

  Moreover, in this Embodiment, when the base material 2 is seen from the normal line direction of the base material 2, for example, in all four directions among the four directions of the top, bottom, left, and right determined on the base material 2 corresponding to the top, bottom, left and right The mesh layer 100 is located outside the antenna layer 10. Although the present invention is not limited to such an embodiment, for example, it is preferable that the mesh layer 100 is located outside the antenna layer 10 in at least two of the four directions of the above, below, left, and right. . This is because the antenna layer 10 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 10 is enhanced by the mesh layer 100. In this embodiment, in addition to this, the invisibility is further enhanced and the visibility in the field of view is increased. Ingenuity to enhance the above-described main body layers 21 and 121 and low reflection layers 22 and 122 is provided. Hereinafter, the main body layers 21 and 121 and the low reflection layers 22 and 122 will be described. In this example, in the antenna layer 10 and the mesh layer 100, the main body layer 21 and the main body layer 121 have the same configuration, and the low reflection layer 22 and the low reflection layer 122 have the same configuration. Therefore, hereinafter, the main body layer 21 and the main body layer 121 will be described together, and the low reflection layer 22 and the low reflection layer 122 will be described together.

  Specifically, first, the main body layers 21 and 121 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 44 or mesh conductor 144 can be prevented from being increased, and external light or video light (when the display is installed) is reflected on the side surface of the antenna conductor 44 or mesh conductor 144. 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 21 and 121 can improve the invisibility and improve the visibility, while increasing the electrical resistance value of the antenna conductor 44 or the mesh conductor 144. Can lead to that. In particular, it is not desirable that the resistance of the antenna conductor 44 is excessively large. Therefore, in the present embodiment, a metal material having a specific resistance equal to or less than a desired value is used as a material constituting the main body layers 21 and 121. 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 44 can be sufficiently reduced. For example, the sheet resistance value of the main body layers 21 and 121 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 21 and 121, 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 21 and 121. In the present embodiment, the main body layers 21 and 121 are made of a copper foil (copper thin film) laminated on the base material 2 via the transparent adhesive layer 3.

  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 44 or the mesh conductor 144, visibility is hindered by the metallic luster of the antenna conductor 44 or the mesh conductor 144. 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 21 and 121 but suppresses the metallic luster on the surface of the main body layers 21 and 121 as compared with the main body layers 21 and 121. Further, thin low reflection layers 22 and 122 are provided. Thereby, the metallic luster of the antenna conductor 44 or the mesh conductor 144 is reduced. Specifically, the low reflection layers 22 and 122 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 22 and 122 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 22 and 122 is 30% or less, and preferably 27% or less. Here, the reflection Y value is a value according to JIS Z8722-1982, and means a reflectance with respect to light having a wavelength in the vicinity of 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 22 and 122 formed using such copper nitride, the metallic luster is reduced as compared with the metallic luster in the main body layers 21 and 121. The tinged color has been reduced. Further, the low reflection layers 22 and 122 formed using such copper nitride have a significantly reduced reflection Y value compared to a layer made of copper nitride not containing 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 44 or the mesh conducting wire 144. FIG.

  The low reflection layers 22 and 122 have a smaller thickness than the main body layers 21 and 121. Specifically, the low reflection layers 22 and 122 have a thickness 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 44 or the mesh conductor 144.

  Moreover, the reflectance of the light in the antenna conducting wire 44 or the mesh conducting wire 144 can also be lowered by setting the thickness of the low reflective layers 22 and 122 within the range of 10 nm to 60 nm. Examples of this reason include, but are not limited to, thin film interference that occurs in the low reflective layers 22 and 122. The thin film interference is a phenomenon in which light reflected on one surface of the low reflection layers 22 and 122 interferes with light reflected on the other surface of the low reflection layers 22 and 122. By setting the thicknesses of the low reflection layers 22 and 122 within the above-mentioned range of 10 to 60 nm, thin film interference occurs so as to weaken the reflected light, and thereby the reflectance of light in the antenna conductor 44 or the mesh conductor 144 is increased. It can be considered to be reduced.

  A method for forming the thin low-reflection layers 22 and 122 as described above is not particularly limited, and a known thin film forming method such as a sputtering method, a vacuum evaporation method, a CVD method, an ion plating method, or an electron beam method is 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 22 and 122 are laminated on the main body layers 21 and 121. The low reflection layers 22 and 122 are the surfaces of the main body layers 21 and 121 on the base material 2 side, or the base material. You may laminate | stack on the surface of 2 sides, and the surface on the opposite side. Further, a blackened layer may be used in place of the low reflective layers 22 and 122. Further, for example, a mode in which the low reflection layer 22 is provided in the main body layer 21 but the low reflection layer 122 is not provided in the main body layer 121 may be employed.

(Surface characteristics of antenna layer and mesh layer)
Moreover, in this Embodiment, the device for reducing the haze in the antenna 1 is also made | formed. Below, the surface characteristic of the antenna layer 10 and the mesh layer 100 in this Embodiment is demonstrated. In the present embodiment, in order to reduce the haze in the antenna 1, the surface of the antenna layer 10 and the mesh layer 100 on the substrate 2 side is devised. In this example, the surface characteristics of the antenna layer 10 and the mesh layer 100 are the same. Therefore, hereinafter, the antenna layer 10 and the mesh layer 100 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 10a and 100a of the antenna layer 10 and the mesh layer 100 on the transparent adhesive layer 3 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 21 and 121 are made of a copper foil (copper thin film) laminated on the base material 2 via the transparent adhesive layer 3. In this case, the surfaces of the antenna layer 10 and the mesh layer 100 provided on the base material 2 and the opening regions 46 and 146 of the mesh layer 100, that is, the exposed surface of the transparent adhesive layer 3 face the copper foil on the base material 2 side. The fine uneven shape (smooth surface with low light scattering property) is transferred. Therefore, the diffused light reflectance (R _SCI ) with respect to the total light reflectance ( _RSCI ) measured on the surface of the transparent adhesive layer 3 exposed from the opening regions 46 and 146 of the antenna layer 10 and the mesh layer 100 in accordance with JIS Z8722 ( R _SCE ) (R _SCE / R _SCI ) and the surfaces of the antenna layer 10 and the mesh layer 100 that are in contact with the conductive wires 44 and 144, that is, the transparent adhesive layer 3 of the antenna layer 10 and the mesh layer 100 (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.

Accordingly, in this embodiment, numerical values of the light reflectance ratio at the exposed transparent adhesive layer 3 of the surface from the opening region 46, 146 of the antenna layer 10 and the mesh layer 100 _(R SCE _/ R _SCI) is measured directly In the form of a transparent antenna, i.e., because most of the light is transmitted through the exposed adhesive layer;
Base material 2 / transparent adhesive layer 3 / antenna layer 10 and mesh layer 100
In the laminate, the measurement light is incident from the substrate 2 side, passes through the intervening substrate 2 and the transparent adhesive layer 3, and is reflected by the surfaces of the antenna layer 10 and the mesh layer 100 ( ( _RSCE / _RSCI ) is measured and indirectly evaluated.

  As a result of the experiments by the present inventors, the surface of the copper foil to be bonded to one surface of the base material 2 via the transparent adhesive layer 3 is smooth and exposed to the opening regions 46 and 146 to which this surface is transferred. It was confirmed that the surface of the transparent adhesive layer 3 to be able to reduce the haze of the antenna 1 obtained when light transmission is mainly parallel light transmission 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 B0601 arithmetic average roughness Ra. Here, the arithmetic average roughness Ra of JIS B0601 is extracted from the roughness curve by the reference length L in the direction of the average line, and the absolute value of the deviation from the average line of the extracted portion to the measurement curve is totaled. 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 was between the haze value transferred to the surface of the transparent adhesive layer 3 in the opening regions 46 and 146 after the etching process and the appearance of the metal foil surface. We found that there was no correlation. The correlation between the ten-point average roughness (specified in JIS B0601 (1994 edition)) that has been used as an index of specularity and the haze transferred to the adhesive layer surface is the same, and the correlation is clear. is not. 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 have reduced 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 3 side into a mirror surface with low light scattering properties. I found. Specifically, on one side of the substrate 2, diffuse light reflection surface of the copper foil bonded via the transparent adhesive layer 3, the total light reflectance was measured in accordance with JIS Z8722 for (R _SCI) rate if the ratio of _{(R SCE) (R SCE /} R SCI) is in the range of 0.4 or less, regardless of the value of the arithmetic average roughness Ra of the surface, the antenna layer 10 and the mesh layer 100 after the etching process It has been found that the haze of light transmitted through the opening regions 46 and 146 can be reduced. Therefore, 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 10a and 100a on the adhesive layer 3 side of the antenna layer 10 and the mesh layer 100 ( 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 3, it is a value that directly affects the haze of the transmitted light of the obtained antenna. In the present embodiment, the surfaces on the base material 2 side of the antenna layer 10 and the mesh layer 100 are smooth surfaces 10a and 100a having low light scattering properties (by selecting the surface on which the copper foil is applied). , the total light reflectance of the transparent adhesive layer 3 of the surface at the opening region 46, 146 of the antenna layer 10 and the mesh layer 100 diffuse light reflectance for _{(R SCI)} the ratio of _{(R SCE) (R SCE /} R SCI) It can be set as the said specific range, and since the surface of the transparent adhesive layer 3 becomes a shape which is hard to scatter transmitted light, 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 10 and the mesh layer 100. FIG.

Total light reflectance was measured in accordance with JIS Z8722-1982 of the copper foil surface in the present embodiment _{(R SCI)} is in compliance with JIS Z8722-1982, spectrophotometer (e.g., Konica Minolta Sensing, Inc. CM-3600d) is set to the reflection mode, the light source is standard light D65, the field of view is 2 °, the measurement diameter is 4 mmφ or more, and the detector combines both diffuse reflection and specular reflection of the reflected light. The Y value (Y of tristimulus values XYZ) is measured by setting the SCI (Special Component Include) mode to measure the (integral) intensity of the total reflected light. The diffusion light reflectance was measured in accordance with JIS Z8722-1982 of the copper foil surface _{(R SCE)} is similarly using spectrophotometer, a light source, field of view, and measuring the diameter is the same as above, The detector is set to an SCE (Special Component Exclude) mode that measures the (integral) intensity of only diffusely reflected light in the reflected light, and the Y value (Y of tristimulus values XYZ) is measured. . Here, the tristimulus value XYZ is defined by JIS Z8722-1982, and is determined by illuminating a sample placed in an ideal environment with a standard light source and calculating the spectral analysis result of the reflected light from the sample. It is a value to be set.

As described above, the degree of haze reduction has a low dependency (correlation) on the arithmetic average roughness Ra defined in JIS B0601. However, if the value of Ra becomes too large, there is generally no mistake in increasing the surface irregularities, so that the haze of the exposed surface of the transparent adhesive layer 3 also 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 1 according to the present embodiment will be described. As an application of the antenna 1, first, an antenna for a mobile phone is cited. In this case, for example, as shown in FIG. 5, the antenna 1 may be attached to a part of the casing 301 of the mobile phone 300. The antenna 1 may be configured to receive radio waves such as transmission / reception of radio waves in the telephone / internet communication function, broadcasting of television and radio, GPS (Global Positioning System (Global Positioning System)) satellite, and the like. Good. The illustrated mobile phone 300 is of a two-fold type, and includes a display screen (subwindow) 302 on the outer surface in a folded state. The antenna 1 is attached to the entire display range of the display screen 302. A feeding electrode (not shown) of the antenna 1 is connected to a transmission / reception unit in the mobile phone 300 via an input / output terminal provided on the outer frame of the display screen 302. The antenna 1 may be partially attached to a part of the display screen 302.

  The antenna 1 may be a car navigation antenna. In this case, for example, as shown in FIG. 6, the antenna 1 may be attached to the windshield 311 of the automobile. The antenna 1 may be connected to the TV tuner of the car navigation device 312 and configured to transmit and receive GPS satellite radio waves.

  The antenna 1 may be a security system antenna. In this case, as shown in FIG. 7, the antenna 1 may be attached to the window glass 314 of the building 313. The antenna 1 may be configured to transmit a signal to the receiving device when the window glass 314 is broken, thereby detecting an abnormality.

The antenna 1 may be a product management antenna. In this case, as shown in FIG. 8, in an RFID (radio frequency identification) tag 315 including the IC chip 316 and the antenna 1, information stored in the memory of the IC chip 316 when the antenna 1 receives a calling radio wave from the reader / writer. The antenna 1 may be configured to transmit to the reader / writer. Thereby, information processing such as product entry / exit, inventory, and sales management may be performed.
The antenna 1 may be configured to receive radio waves of ETC (Electronic Toll Collection System (abbreviation of electronic toll collection system)).

(Antenna manufacturing method)
Next, a method for manufacturing the antenna 1 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 disposed on the first surface 2a, which is one surface of the substrate 2, with the R _SCE / _RSCI of 0.4 or less facing the substrate 2 via the transparent adhesive layer 3 The process of laminating together is performed. In this step, first, a substrate 2 is prepared, and a transparent adhesive layer 3 is formed by coating the first surface 2a of the substrate 2 with a transparent adhesive. The layer forming method of the transparent adhesive layer 3 may be a known layer forming method, for example, a coating method such as roll coating, comma coating, gravure coating, die coating, or screen printing, gravure that allows easy partial formation in an arbitrary shape. Printing methods such as printing can be appropriately employed. Next, the copper foil is laminated on the surface of the transparent adhesive layer 3 of the substrate 2 with the smooth surface side having a low light scattering property directed.

  Next, on the copper foil on the transparent adhesive layer 3, a copper nitride layer that becomes the low reflection layers 22 and 122 after completion is laminated. 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 10 and the mesh layer 100 is performed by etching the copper foil and the copper nitride layer into a predetermined pattern shape. In this step, first, a resist layer is provided in a predetermined mesh pattern shape corresponding to the antenna layer 10 and the mesh layer 100 on the copper foil and the copper nitride layer laminated on the base material 2 and covered with the resist layer. The antenna layer 10 and the mesh layer 100 are formed by an etching method that removes the resist layer after removing the copper foil and the 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 2. 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 10 and the mesh layer 100. 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 main body layers 21 and 121 and the low reflection layers 22 and 122 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. In this way, the antenna layer 10 and the mesh layer 100 having the main body layers 21 and 121 and the low reflection layers 22 and 122 are obtained.

(effect)
The antenna 1 according to the present embodiment described above includes a base material 2 formed in a sheet shape, a mesh-like antenna layer 10 provided on the base material 2 and having light shielding properties and conductivity, and a base material 2. A mesh-like mesh layer 100 having a light shielding property, and when the base material 2 is viewed from the normal direction of the base material 2, the mesh layer 100 has a gap G with respect to the antenna layer 10. It is open and located outside the antenna layer 10. Thereby, only by providing the mesh layer 100 outside the antenna layer 10, the antenna layer 10 does not appear to be locally installed, and the antenna layer 10 does not stand out. Thereby, the invisibility of the antenna layer 10 can be increased easily.

  Further, the function can be expanded by adding a function different from that of the antenna layer 10 to the mesh layer 100, 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. .

  In the present embodiment, the antenna layer 10 and the mesh layer 100 are formed in the same mesh pattern shape. Thereby, since the difference of the transmittance | permeability between the antenna layer 10 and the mesh layer 100 can be suppressed, invisibility can be improved effectively. The antenna layer 10 and the mesh layer 100 are provided on the same plane. For this reason, manufacture becomes easy and manufacturing efficiency can be improved.

  Further, the base material 2 is provided with an extraction electrode portion 11 that is electrically connected to a part of the outer peripheral portion of the antenna layer 10 and extends outward from the antenna layer 10, and the mesh layer 100 is an extraction electrode in the antenna layer 10. It is located so as to surround the entire outer peripheral portion excluding the connection position of the portion 11. Thereby, since the antenna layer 10 becomes inconspicuous surely, invisibility can be improved reliably.

  Further, the mesh layer 100 is arranged so that the mesh conductor 144 extends on an extension line EL toward the mesh layer 100 of the antenna conductor 44 whose end is located on the outermost periphery of the antenna layer 10. Thereby, since the dispersion | variation in the transmittance | permeability of the light around the boundary of the antenna layer 10 and the mesh layer 100 can be suppressed, invisibility can be improved effectively. In addition, when the gap G between the mesh layer 100 and the antenna layer 10 is 10 μm or more and 300 μm or less, both invisibility can be ensured and an appropriate function of the antenna layer 10 can be achieved.

  In the present embodiment, the antenna layer 10 and the mesh layer 100 are laminated on the opposite side of the base material 2 with respect to the main body layers 21 and 121 mainly composed of copper and the main body layers 21 and 121. Low reflection layers 22 and 122 made of copper nitride containing oxygen atoms at a depth of 5 nm or more from the surface, and the film thickness of the low reflection layers 22 and 122 is 10 nm to 60 nm. The reflection Y value of is 30% or less.

  Thereby, it is possible to suppress the reddish light from reaching the observer due to the metallic luster of copper by the low reflection layers 22 and 122. Further, since the film thickness of the low reflection layers 22 and 122 is 10 nm to 60 nm and the reflection Y value of the low reflection layers 22 and 122 is 30% or less, preferably 27% or less, the antenna conductor 44 or the mesh conductor 144 It can suppress that visibility falls by reflected light of. Further, since each of the main body layers 21 and 121 and the low reflection layers 22 and 122 contains copper, the antenna layer 10 and the mesh layer 100 are simultaneously formed by using an etching solution that can selectively dissolve copper. be able to. For this reason, the man-hour required in order to produce the antenna layer 10 and the mesh layer 100 can be made small.

The antenna layer 10 and the mesh layer 100 include copper as a main component, and are provided on one surface of the substrate 2 via the transparent adhesive layer 3, and the antenna layer 10 and the transparent adhesive layer 3 of the mesh layer 100. total light reflectance was measured in conformity with JIS Z 8722 of the side surface diffusion light reflectance for _{(R SCI)} ratio _{(R SCE) (R SCE /} R SCI) is 0.4 or less. Thereby, since the surface of the transparent adhesive layer 3 becomes a shape which 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 1)
FIG. 9 is a plan view of an antenna according to the first modification, and FIG. 10 is a cross-sectional view taken along line XX of FIG. 9 and 10, the antenna layer 10 is provided on the first surface 2a of the base material 2, and the mesh layer 100 is provided on the second surface 2b of the base material 2. Yes. A gap G is provided between the antenna layer 10 and the mesh layer 100 as in the above-described embodiment. Even with such a configuration, the invisibility of the antenna layer 10 can be easily increased.

(Modification 2)
FIG. 11 is a plan view of an antenna according to the second modification. In Modification 2, as shown in FIG. 11, the antenna layer 10 and the mesh layer 100 are formed in different mesh pattern shapes. In particular, in the illustrated example, the mesh pattern shape of the antenna layer 10 and the mesh pattern shape of the mesh layer 100 are similar, but the size and pitch of the opening regions are different from each other. Specifically, the length of one side of the square mesh opening region 146 is twice the length of one side of the antenna opening region 46, and the mesh opening region 146 is constant in the first direction d1 and the second direction d2. The pitch is twice the fixed pitch of the antenna opening area 46.

  On the other hand, in the second modification, when the extension line EL to the mesh layer 100 side of the antenna conductor 44 whose end is located on the outermost periphery of the antenna layer 10 is extended, as in the above-described embodiment. The mesh layer 100 is disposed so that the mesh conductor 144 extends on the extension line EL. Even with such a configuration, the invisibility of the antenna layer 10 can be easily increased.

(Modification 3)
12 is a plan view of an antenna according to Modification 3. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. In Modification 3, as shown in FIGS. 12 and 13, the second mesh layer 200 is provided on the second surface 2 b of the substrate 2, and the second mesh layer 200 is in the normal direction of the substrate 2. , It is located in a gap G provided between the antenna layer 10 and the mesh layer 100.

  The second mesh layer 200 includes a plurality of second mesh conductors 244 arranged in a mesh pattern on the second surface 2 b of the substrate 2, and a plurality of second antenna opening regions 246 are defined by the plurality of second mesh conductors 244. It is defined. The second mesh conductor 244 is a linear portion extending between the two branch points 247. In the illustrated example, the antenna layer 10, the mesh layer 100, and the second mesh layer 200 are formed in the same mesh pattern shape. Also in the third modification, when the extension line EL (see the thick two-dot chain line) of the antenna conductive wire 44 whose end is located on the outermost periphery of the antenna layer 10 is extended to the mesh layer 100 side, this extension line is used. The mesh layer 100 is disposed so that the mesh conductor 144 extends on the EL. On the other hand, the second mesh layer 200 is disposed so that the second mesh conductive wire 244 overlaps the extension line EL when viewed from the normal direction of the substrate 2.

  According to such a configuration, since the antenna layer 10 is not clearly noticeable, the invisibility of the antenna layer 10 can be effectively increased.

(Modification 4)
FIG. 14 is a plan view of the antenna layer 10 of the antenna according to the fourth modification, FIG. 15 is an enlarged view of FIG. 14, and FIG. 16 is a diagram showing a general image display mechanism 320. As shown in FIGS. 14 and 15, in the fourth modification, in the antenna layer 10, the antenna opening region 46 can change its shape without greatly disturbing the periodicity of the arrangement, thereby varying the opening area. It is like that. Although not shown, the mesh layer 100 is also the same. The modification 4 is different from the above-described embodiment in this point.

In the display area of the image display mechanism 320 shown in FIG. 16, pixels P for forming an image are regularly arranged. The antenna 1 is also assumed to be installed on a film or the like that covers such an image display mechanism 320. In a general image display mechanism 320, pixels are arranged at a constant pitch in both the horizontal direction (direction d _x in FIG. 16) and the direction d _y (eg, the vertical direction) orthogonal to the horizontal direction in the installed state of the image display mechanism 320. 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 1 overlaps the image display mechanism 320 having the pixel arrangement, when the antenna layer 10 of the antenna 1 and the opening regions 46 and 146 of the mesh layer 100 are regularly arranged, the pixel P is regularly (periodic). There is a possibility that a striped pattern resulting from the pattern and the arrangement pattern of the opening regions 46 and 146 of the antenna layer 10 and the mesh layer 100, 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 studies by the present inventors, the pattern of the antenna layer 10 and the mesh layer 100 is aperiodic enough to make the moire inconspicuous, that is, when the opening regions 46 and 146 are irregularly arranged. It has been found that the moire can be made inconspicuous, but instead, the unevenness of density due to the density variation of the open regions 46 and 146 becomes conspicuous. 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 46, 146, in other words, a region inside the plurality of conducting wires 44, 144 surrounded by the plurality of conducting wires 44, 144 defining the opening regions 46, 146. 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 in the opening area of the opening regions 46 and 146, 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 46 and 146 in the antenna layer 10 and the mesh layer 100 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 opening area of the opening region 46 in the antenna layer 10 and the standard deviation σ of the area of the opening region 46 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 10. Similarly, regarding the mesh layer 100, when the average value m of the opening area of the opening region 146 and the standard deviation σ of the area of the opening region 146 are satisfied, it is preferable that the above-described formula (a) is satisfied.

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 opening areas 46 and 146 included in one target antenna layer 10 and mesh layer 100 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 the opening areas 46 and 146 included in one antenna layer 10 and the mesh layer 100 become. Similarly, “m−1.5σ” in the formula (a) is assumed that the distribution of the opening areas 46 and 146 included in one target antenna layer 10 and mesh layer 100 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 46 and 146 included in one antenna layer 10 and the mesh layer 100. 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 cause a problem in normal use in combination with the image display mechanism 320. 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 expressions (d) and (e), the ratio of the opening areas 46 and 146 to which the opening area values of all the opening areas 46 and 146 should be considered is increased as compared with the expressions (a) to (c). . Therefore, it is possible to control the overall distribution of the opening areas of the opening regions 46 and 146 included in one antenna layer 10 and the mesh layer 100 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 46,146 contained in the one antenna layer 10 and the mesh layer 100 can be specified based on the image data acquired by an image processing apparatus as an example. For example, first, the antenna layer 10 and the mesh layer 100 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. 14, an example of the antenna layer 10 in Modification 4 is shown. The pattern of the antenna layer 10 includes a group for generating the antenna layer 10 according to the modified example 4 formed by a plurality of line segments 63 extending between the two intersections 62 and defining the opening region (opening) 61. On the basis of the reference mesh pattern 60 (see FIG. 15), it is determined that the arrangement period of the reference mesh pattern is modified so as to be irregular. More specifically, the pattern of the antenna layer 10 is based on the reference mesh pattern 60 in which the opening regions 61 are regularly arranged, in other words, the opening regions 61 are arranged with periodicity. In addition, while maintaining the uniformity of the arrangement position of the opening region 61 so as not to cause uneven shading, on the other hand, the shape of the opening region 61 is changed to such an extent that the moire can be sufficiently invisible. It is determined by varying the area.

  In the fourth modification, the antenna layer 10 and the mesh layer 100 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 10 in the modification 4 and the mesh layer 100 is demonstrated. In the method described below, a step of determining a reference mesh pattern 60 formed from a plurality of line segments 63 extending between two intersections 62 and defining an open area 61, and the intersection 62 of the reference mesh pattern 60 is determined. Based on the step of determining the positions of the branch points 47 and 147 in the antenna layer 10 and the mesh layer 100 based on the line segment 63 of the determined branch points 47 and 147 and the reference mesh pattern 60, the antenna conductor 44 and the mesh conductor 144 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 10 and the mesh layer 100, that is, the reference mesh pattern 60 is determined. The reference mesh pattern 60 determined here is formed of a plurality of line segments 63 that extend between two intersections 62 and define an open region 61. In the reference mesh pattern 60, the opening regions 61 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 areas 61, and the various opening areas 61 may be regularly arranged in two or more directions that intersect.

  As shown in FIG. 15, in the illustrated reference mesh pattern 60, a fixed rectangular opening region 61 is a pattern that is spread without gaps. The opening regions 61 are arranged at a constant pitch in the first direction d1 and the second direction d2 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. Is defined by a group of second straight lines 60b extending linearly in the second direction d2 and arranged at a constant pitch P2 identical to the constant pitch P1 in a direction perpendicular to the second direction d2. As a result, the opening regions 61 included in the reference mesh pattern 60 are all formed in the same quadrangular shape, particularly a rhombus shape.

Incidentally, in general, from the viewpoint of invisible moire caused by interference between the pixel arrangement and the antenna layer 10 and the mesh layer 100 of the image display mechanism 320, the arrangement direction of the pixels in the image display mechanism 320 d _x, to d _y, antenna The arrangement direction of the opening regions 46 and 146 of the layer 10 and the mesh layer 100 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. 16, further, even for diagonal d _o of the pixel, the aperture It was effective to incline the arrangement direction of the regions 46 and 146. This is because, as shown in FIG. 16, light-shielding portions arranged with a wide width portion 321a of a light-shielding portion (for example, a black matrix) 321 that defines the pixel P arranged at diagonal positions, and arranged at regular intervals. This is probably because moire between the thick portion 321a of the 321 and the opening regions 46 and 146 is likely to occur.

The general pixels P arranged in a square lattice have a square shape when viewed from the normal direction of the substrate, that is, 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, arrangement direction of the opening area 46 and 146 are perpendicular to the pixel arrangement direction d _x, one of the 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 46 and 146 is, that 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 10 and the mesh layer 100 described here, the opening regions 46 and 146 of the antenna layer 10 and the mesh layer 100 generally follow the arrangement direction of the opening regions 61 of the reference mesh pattern 60. Become. The arrangement direction of the opening regions 61 in the reference mesh pattern 60 is the first direction d1 and the second direction d2. Therefore, the first direction d1 and the second direction d2 determines the orientation of the opening region 61 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 An angle of 30 ° or more and 40 ° or less is preferable, an angle of 33 ° or more and 37 ° or less is more preferable, and an angle θ _1x or θ _2x of 35 ° is most preferable as shown in FIG. . The angle θ _x formed by the first direction d1 and the second direction d2 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, it is 70 °. Also, see the first direction d1 and the second direction d2 determines the direction of the opening region 61 included in the mesh pattern 60, the other d 60 ° angle of less than 50 ° or more with respect to _y of the pixel arrangement direction orthogonal Is more preferable, an angle of 53 ° to 57 ° is more preferable, and an angle θ _1y and θ _2y of 55 ° is most preferable as shown in FIG.

  Next, a process of determining the positions of the branch points 47 and 147 based on the intersection 62 of the reference mesh pattern 60 will be described. In this step, the position of one branch point 47 is determined from one intersection point 62 of the reference mesh pattern 60. Specifically, each branch point 47 is arranged on the corresponding intersection 62 of the reference mesh pattern 60 or at a position shifted from the corresponding intersection 62 by a length equal to or less than a predetermined length. At this time, the shapes of the opening regions 46 and 146 of the finally obtained antenna layer 10 and mesh layer 100 are determined by irregularly determining the amount of deviation and the direction of deviation of each branch point 47 from the corresponding intersection point 62. It is not constant, and moire can be effectively inconspicuous. In addition, when the deviation amount selected irregularly becomes 0, the branch points 47 and 147 may be positioned on the corresponding intersection point 62. Further, by providing a restriction on the amount of deviation of each branch point 47, 147 from the corresponding intersection point 62, 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 10 and the mesh layer 100.

  It should be noted that the amount of deviation of each branch point 47, 147 from the corresponding intersection 62 is less than half the arrangement pitch of the opening regions 61 in order to avoid the conductors 44, 144 coming into contact with other conductors. Is preferred. This is because when one conductor 44, 144 overlaps with another conductor 44, 144, the part is visually recognized and may cause uneven density. Specifically, in order to avoid that the conducting wires 44 and 144 come into contact with the other conducting wires 44 and 144, the amount of deviation of each branch point 47 and 147 from the corresponding intersection 62 is a direction orthogonal to the first direction d1. And less than half of the arrangement pitch P1 of the first straight line 60a group and less than half of the arrangement pitch P2 of the second straight line 60b group in the direction orthogonal to the second direction d2.

Further, instead of determining both the amount of deviation from the corresponding intersection 62 and the direction of deviation for each branch point 47, 147, each branch point 47, 147 is preset from the corresponding intersection 62. 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 mechanism 320, the deviation amount [delta] _x of the corresponding intersection 62 to _{d y,} [delta] _y (see FIG. 15), then determined for each branch point 47,147 You may make it go. In this example, below a certain percentage of arrangement pitch p _x of the opening region 61 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 61 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 47 from the corresponding intersection point 62.

  Next, the process of determining the positions of the conducting wires 44 and 144 will be described. When the positions of the branch points 47 and 147 in the antenna layer 10 and the mesh layer 100 are determined as described above, the positions of the conductors 44 and 144 are then determined based on the determined branch points 47 and 147. Specifically, the positions of the conductors 44 and 144 so as to extend between the two branch points 47 and 147 respectively corresponding to the two intersections 62 located at both ends of a certain line segment 63 of the reference mesh pattern 60. To decide. The path of the conducting wires 44 and 144 between the two branch points 47 and 147 may be a straight line, a curved line, a broken line, or a combination of a straight line and a curved line. Also good. Further, the line widths of the conductive wires 44 and 144 can be set to 0.2 μm or more and 2 μm or less as described above, or may have a thickness outside this range.

  In this way, the antenna layer 10 and the mesh layer 100 are formed. Since the positions of the branch points 47 and 147 of the antenna layer 10 and the mesh layer 100 are determined based on the position of the intersection 62 of the reference mesh pattern 60 having regularity, the obtained antenna layer 10 and mesh layer 100 are obtained. As a result, the opening regions 46 and 146 are uniformly dispersed to a certain extent, thereby suppressing the occurrence of uneven density. However, the positions of the branch points 47 and 147 are deviated from the positions of the corresponding intersections 62 by an amount within a predetermined range selected irregularly. Therefore, the obtained antenna layer 10 and mesh layer 100 lose the regularity or uniformity of the shape or opening area of the opening regions 46 and 146, and can also avoid problems due to moire.

  The antenna layer 10 and the mesh layer 100 whose patterns are determined as described above are produced on the base material 2 by patterning a copper foil or the like formed on the base material 2 using a photolithography technique. obtain.

In Modification 4 as described above, the average value m of the opening areas 46 and 146 included in the antenna layer 10 and the mesh layer 100 and the standard deviation σ of the areas of the opening areas 46 and 146 are expressed by the equation (a). It comes to satisfy. As a result, it is possible to effectively prevent the moire and shading unevenness from being visually recognized due to the target antenna layer 10 and mesh layer 100.
3 ≦ (((m + 1.5σ) − (m−1.5σ)) / m) × 100 ≦ 20 (a)

In addition, the average value m of the opening areas 46 and 146 included in the antenna layer 10 and the mesh layer 100 and the standard deviation σ of the areas of the opening areas 46 and 146 satisfy Expression (b) or Expression (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)

DESCRIPTION OF SYMBOLS 1 ... Antenna 2 ... Base material 2a ... 1st surface 2b ... 2nd surface 10 ... Antenna layer 11 ... Extraction electrode part 21 ... Main body layer 22 ... Low reflection layer 44 ... Antenna conducting wire 46 ... Antenna opening area 47 ... Branch point 61 ... Opening area 62 ... Intersection 63 ... Line segment 100 ... Mesh layer 100a ... Smooth surface 100b ... Non-smooth surface 121 ... Main body layer 122 ... Low reflection layer 144 ... Mesh conductive wire 146 ... Mesh opening region 147 ... Branching point G ... Gap FL1 ... Contour line

Claims (15)

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 the base material is viewed from the normal direction of the base material, the mesh layer is located outside the antenna layer with a gap from the antenna layer.   The antenna according to claim 1, wherein the antenna layer and the mesh layer are formed in the same mesh pattern shape.   The antenna according to claim 1 or 2, wherein the antenna layer and the mesh layer are provided on the same plane.   When the base material is viewed from the normal direction of the base material, the mesh layer is located outside the antenna layer in at least two directions among four directions of up, down, left, and right determined on the base material. The antenna according to any one of claims 1 to 3. 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 4, wherein the mesh layer is positioned so as to surround the entire area of the outer peripheral portion excluding a connection position of the extraction electrode portion in the antenna layer.   The antenna according to claim 1, wherein a gap between the mesh layer and the antenna layer is 10 μm or more and 300 μm or less. 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 any one of claims 1 to 6, 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. .   The mesh layer is located with a gap with respect to a contour line defined by connecting ends of the plurality of antenna conductor wires located at the outermost periphery in the antenna layer with straight lines. Antenna. At least one of the antenna layer and the mesh layer 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 or 8, wherein the reflection Y value of the low reflection layer is 30% or less.   The mesh layer is arranged so that the mesh conductor extends on an extension line of the antenna conductor, the end of which is located on the outermost periphery of the antenna layer, toward the mesh layer. The antenna according to Crab. The antenna according to any one of claims 7 to 9, 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 11, wherein an average value m of the area of the mesh opening region in the mesh layer and a standard deviation σ of the area of the mesh opening region satisfy the following expression.
3 ≦ 3σ / m × 100 ≦ 20   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 of claim 13, 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 13 or 14, which is 4 or less.

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