WO2007119798A1

WO2007119798A1 - Radio wave shielding body and method of producing the same

Info

Publication number: WO2007119798A1
Application number: PCT/JP2007/058106
Authority: WO
Inventors: Kazuyuki Kashihara; Toshio Kudo; Satoshi Sakai
Original assignee: Mitsubishi Cable Industries, Ltd.
Priority date: 2006-04-18
Filing date: 2007-04-12
Publication date: 2007-10-25
Also published as: GB0820928D0; GB2451389B; JP2007285026A; JP4171500B2; KR101050026B1; GB2451389A; KR20080111541A

Abstract

A radio wave shielding body easily produceable and having desired radio wave shielding ability. The radio wave shielding body has a base (10) having on its surface at least either pores or projections/recesses, a coating film (11) formed on the surface of the base (10), and antennas (13) formed on the coating film (11) from a radio wave reflecting material.

Description

Specification

Radio wave shield and manufacturing method thereof

Technical field

The present invention relates to a radio wave shield and a method for manufacturing the same.

Background art

[0002] In recent years, as the use of wireless devices such as PHS and wireless LAN in offices has expanded, offices can be used from the standpoint of preventing information leakage and preventing malfunctions and noise caused by incoming radio waves from outside. It is indispensable to prepare the radio wave environment in the house. Conventionally, various types of members have been proposed as members for maintenance of radio wave environments such as offices (for example, Patent Documents 1 and 2).

[0003] For example, Patent Document 1 discloses an electromagnetic shield capable of information communication using radio waves of an arbitrary frequency in a wide frequency band by adding an electromagnetic shield member such as metal or ferrite to a building frame. Intel Genetville is disclosed. As radio wave shielding members, radio wave reflectors such as iron plates, metal nets, metal meshes, metal foils, and radio wave absorbers such as flight are disclosed.

[0004] However, these radio wave reflectors and radio wave absorbers do not have frequency selectivity! For this reason, the electromagnetic shield 'Intelgent Building' disclosed in Patent Document 1 cannot selectively shield radio waves of a specific frequency, and has a problem that it shields radio waves other than the frequency to be shielded.

[0005] On the other hand, Patent Document 2 discloses an electromagnetic shielding building characterized in that an electromagnetic shielding space is secured in a building by an electromagnetic shielding surface in which "Y" -shaped linear antennas are regularly arranged. ing. The “Υ” -shaped linear antenna is composed of three line-shaped element parts extending radially with the antenna central force approximately the same length. Patent Document 2 describes that according to the electromagnetic shielding building disclosed in Patent Document 2, it is possible to select an electromagnetic wave of a necessary frequency and perform electromagnetic shielding.

Patent Document 1: Japanese Patent Publication No. 6-99972

Patent Document 2: JP-A-10-169039 Disclosure of the invention

Problems to be solved by the invention

[0006] By the way, when preparing the indoor radio wave environment, it is also necessary to provide a radio wave shielding property that shields only radio waves of a desired frequency on curtains, cloths attached to walls and ceilings, concrete walls, and the like. Is preferred. In that case, cloth-like objects such as cloths stuck to curtains, walls, ceilings, etc., and concrete walls! It is necessary to form an antenna.

[0007] On the other hand, as a method for forming an antenna, it is generally performed by liquefying a radio wave reflecting material and applying and drying (that is, by a wet method). The method is usually not suitable for forming an antenna because it requires a large-scale device with high cost and is relatively time-consuming.

[0008] While trying to form an antenna as described in Patent Document 2 using a radio wave reflecting material on a base material (for example, a cloth-like body) having micropores on its surface, Due to the capillary phenomenon, the liquid material bleeds into the substrate (for example, in the case of a woven fabric, it tends to bleed in the fiber arrangement direction), and it is difficult to form an antenna with a desired shape and dimension. It is difficult to obtain a desired radio wave shielding property.

[0009] Even when an antenna such as that described in Patent Document 2 is formed of a material that reflects radio waves on a base material having unevenness on the surface, the dimensions of the formed antenna become inaccurate and soon. After all, it is difficult to obtain a desired radio wave shielding property.

[0010] In the case where the antenna is formed by using a dry method such as a sputtering method without using a liquid material, problems such as bleeding of the liquid material to the base material do not occur, but a large-scale device is used. This leads to problems such as necessity, high manufacturing costs, and complicated manufacturing processes.

The present invention has been made in view of such various points, and a main object thereof is to provide a radio wave shield having a desired radio wave shielding property while being easily manufactured. . Means for solving the problem

[0012] In the present invention that solves the above object, as a radio wave shield, a substrate having at least one of a plurality of micropores and a plurality of irregularities on the surface, and formed on the surface of the substrate. And a plurality of radio wave reflecting antennas formed on the coating film using a radio wave reflecting material as a specification material. That is, the plurality of radio wave reflecting antennas are not directly in contact with the substrate surface, but are disposed on the coating film.

[0013] In the above configuration, by providing a coating film on the surface of the base material, micropores (particularly, openings of the micropores) existing on the surface of the base material are blocked, or unevenness is flattened. Therefore, a material that reflects radio waves caused by unevenness on the surface of the base material, which suppresses bleeding (impregnation, specifically impregnation in the direction of the base material surface) that occurs when a material that reflects radio waves penetrates into the micropores, is provided. Thus, it is possible to reduce the dimensional variation and inaccuracy (deviation from the desired size of the radio wave reflecting antenna) of the radio wave reflecting antenna formed by the above.

That is, the coating film substantially eliminates holes and irregularities present on the surface of the base material and flattens the base material surface, and forms a radio wave reflecting antenna on such a coating film. This makes it possible to obtain a desired radio wave shielding property.

[0015] In the radio wave shield configured as described above, the base material has at least one of fine holes and irregularities on the surface, that is, the base material surface is not flat. For example, such a base material includes a cloth-like body (woven fabric, non-woven fabric, knitted fabric, lace, felt, paper, etc.), and a porous body (foam).

[0016] The above-mentioned coating film is a film that can suppress bleeding of a material that reflects an electric wave to the base material (specifically, the surface of the base material) when the base material has a plurality of fine holes. If the substrate has a plurality of irregularities, the coating film is a flattened one, specifically, one that closes the open ends of the micropores present on the surface of the substrate that causes bleeding. There is no particular limitation as long as the surface of the base material is smoothed and the entire thickness (the thickness of the base material + coating film) is made uniform. Those having edge properties are preferred. Specific examples of the coating film material include inorganic materials such as resin and glass, and rubber.

[0017] The radio wave reflecting material is a liquid material (for example, in the form of ink, in the present specification, "liquid material" is a solution composed of a solvent and a solute, or a fine particle in a liquid (a solvent only or a solvent and a solute). It is a concept that includes a dispersion in which a child or a colloidal substance is dispersed and mixed. The term “material” refers to all materials including at least a liquid. ) Is preferable. Specifically, a solution (ink) in which a substance that reflects radio waves is melted, a solution (ink) that contains a substance that reflects colloidal radio waves, and fine particles that substantially consist of substances that reflect radio waves are dispersed and mixed. It may be a fine particle dispersion (ink) or the like. Here, examples of the substance that reflects radio waves include conductive substances. Specifically, examples of the conductive material include copper, aluminum, and silver.

[0018] The radio wave reflecting antenna is preferably one that selectively reflects radio waves of a specific frequency or a specific frequency band. Specific examples of such an antenna include a so-called Jerusalem cross-type antenna and a “Y” -shaped antenna. In addition, each of the radio wave reflecting antennas has three linear first element portions that extend radially with substantially the same length at an antenna central force of approximately 120 ° from each other, and each first element portion. And a second element portion having a line shape coupled to the outer end of the antenna and reflecting a radio wave of a specific frequency (in this specification, an antenna of this shape is referred to as a “Τ-Υ type antenna”) May be called.).

[0019] The manufacturing method according to the present invention is a method for manufacturing a radio wave shield provided with a plurality of radio wave reflecting antennas formed on a substrate having fine holes and ridges or irregularities on the surface. The manufacturing method according to the present invention is characterized in that a plurality of radio wave reflecting antennas are formed of a material that reflects radio waves after the surface of a base material is coated with a coating film.

[0020] Thus, by forming a coating film on the substrate surface prior to the formation of the radio wave reflecting antenna, the substrate surface is smoothed (the entire thickness (substrate + coating film thickness) is uniform). ). Accordingly, bleeding of the material on the surface of the base material is suppressed, and a radio wave reflecting antenna having a desired shape and dimension can be easily and accurately manufactured. Therefore, according to this manufacturing method, it is possible to easily manufacture a radio wave shield having high radio wave shielding properties.

The invention's effect

[0021] According to the present invention, it is possible to provide a radio wave shielding body that can be easily manufactured and has desired radio wave shielding properties.

Brief Description of Drawings FIG. 1 is a plan view showing a configuration of a radio wave shield according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view showing a part of the radio wave shield.

FIG. 3 is a cross-sectional view taken along line III-III in FIG.

FIG. 4 is an enlarged plan view showing the antenna.

FIG. 5 is a plan view schematically showing an enlarged part of a base material that also has a woven cloth force.

FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG.

FIG. 7 is a cross-sectional view showing a state in which the radio wave shield is attached to the wall on the base material side.

[FIG. 8] FIG. 8 is an explanatory view showing the entire roll-shaped radio wave shielding body in which an adhesive and a protective film are formed on the substrate side, and a partially enlarged cross section thereof.

FIG. 9 is a view corresponding to FIG. 7, showing a state in which the radio wave shield is attached to the wall on the reflective layer side.

[FIG. 10] FIG. 10 is a view corresponding to FIG. 8 showing the entire roll-shaped radio wave shielding body in which a pressure-sensitive adhesive and a protective film are formed on the reflective layer side, and a partially enlarged cross section thereof.

[FIG. 11] FIG. 11 is a characteristic diagram showing the relationship between the frequency of radio waves transmitted through the radio wave shield and the amount of transmission attenuation.

FIG. 12 is a characteristic diagram showing the relationship between the element length of an antenna and the frequency (matching frequency) of a radio wave reflected by the antenna.

FIG. 13 is a view corresponding to FIG. 1, showing a first modification of the radio wave shielding body.

FIG. 14 is an enlarged plan view showing the antenna of the first modification.

FIG. 15 is a view corresponding to FIG. 1, showing a second modification example of the radio wave shield.

FIG. 16 is a view corresponding to FIG. 1 and showing a third modification example of the radio wave shield.

FIG. 17 is a view corresponding to FIG. 1 and showing a fourth modification example of the radio wave shielding body.

FIG. 18 is a view corresponding to FIG. 1 and showing a fifth modification example of the radio wave shield.

[FIG. 19] FIG. 19 is a view corresponding to FIG.

FIG. 20 is a characteristic diagram showing the relationship between the radio wave frequency and radio wave shielding amount (radio wave transmission attenuation amount) in Modification 6.

FIG. 21 is a view corresponding to FIG. 1 and showing a modification example 7 of the radio wave shielding body. FIG. 22 is a view corresponding to FIG. 1, showing a modification 8 of the radio wave shield.

FIG. 23 is a view corresponding to FIG. 1, showing a modification 9 of the radio wave shielding body.

FIG. 24 is a view corresponding to FIG. 1 and showing a tenth modification of the radio wave shielding body.

FIG. 25 is a view corresponding to FIG. 1 and showing a modification 11 of the radio wave shielding body.

FIG. 26 is a characteristic diagram showing the relationship between the frequency of radio waves and the amount of transmitted water loss when the radio wave shield of modification 2 is used as an example, together with the comparative example.

Explanation of symbols

1 Radio wave shield

10 Substrate

10a Substrate surface

11 Coating film

12 Reflective layer

13, 16, 17, 22, 24, 25, 26, 27, 28, 29

Antenna (radio-reflection antenna)

13a, 24a, 27a

First element part

13b, 16b, 17b, 27b, 28b, 29b

Second element part

14, 18, 20

Antenna unit

15, 19, 21

Antenna assembly

30 walls

31 Adhesive

32 Protective film

40, 41

Weaving

42 micropores 43 Concave (Uneven)

44 Convex part

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a radio wave shielding body according to the present embodiment, FIG. 2 is an enlarged plan view showing a part of the radio wave shielding body, and FIG. Fig. 4 is a cross-sectional view taken along line III-III of Fig. 2, and Fig. 4 is a plan view showing the antenna enlarged.

The radio wave shield 1 includes a substrate 10 having a surface having at least one of a plurality of fine holes and a plurality of irregularities, a coating film 11, and a reflective layer 12. Note that the radio wave shield 1 may be, for example, a mode that imparts radio wave shielding characteristics to an existing object (eg, a window, a wall, a ceiling, a floor, a partition, a desk, etc.) in a room. In this case, the substrate 10 is preferably in a shape having a flat surface such as a plate shape, a sheet shape, or a film shape.

In the present embodiment, the substrate 10 is not limited as long as it has at least one of a plurality of fine holes and a plurality of irregularities on the surface. As long as that is the case, the base material 10 can be appropriately selected according to the intended use of the radio wave shield 1. For example, the base material 10 may be made of resin, glass, paper, cloth, rubber, gypsum, tile, wood, or the like. Specifically, the base material 10 is made of urethane resin, polyethylene (PE) resin, polystyrene resin resin, etc., wood (including plywood), or woven fabric (for example, plain weave) or non-woven fabric, Cloths such as knitting, lace, felt, and paper (for example, curtains, walls and floors, ceilings, windows, desks, cloths that stick to or stick to partitions, etc.) etc.!

Here, taking as an example the case where the base material 10 is made of woven fabric, “micropores” and “unevenness” existing on the surface of the base material 10 will be described with reference to FIGS. 5 and 6. This will be specifically described. FIG. 5 is an enlarged plan view schematically showing a part of the base material 10 also having a woven cloth force, and FIG. 6 is a sectional view taken along line VI-VI in FIG.

[0029] The base material 10 includes a plurality of first woven fibers 40 extending in parallel with each other, and intersecting the first woven fibers 40.

And second textiles 41 extending in parallel (typically orthogonal) to each other. In plan view, each of the plurality of spaces defined by the first woven fabric 40 and the second woven fabric 41 constitutes the fine holes 42. In addition, as shown in FIG. In the same manner, the first woven fabric 40 passes between the plurality of first woven fabrics 40, and similarly, the first woven fabric 40 also passes between the plurality of second woven fabrics 41 and is serpentine. Therefore, a plurality of concave portions 43 and convex portions 44 (that is, concave and convex portions) are formed on the surface 10a of the base material 10 on which the coating film 11 is formed. As will be described in detail below, the coating film 11 is for filling the fine holes 42 (specifically, openings of the fine holes 42) and flattening the concave portions 43 and the convex portions 44.

[0030] In order to install the radio wave shield 1 in which the reflective layer 12 is formed on the surface of the base material 10 on an existing object in the room (for example, a window, a wall, a ceiling, a floor, a partition, a desk, etc.) At least one of the surface on which the reflective layer 12 is formed and the surface on the opposite side thereof is coated with an adhesive or an adhesive (or is subjected to adsorption processing), and the surface of the adhesive or the adhesive is applied to the surface. It is good also as an aspect which provides a protective layer, rolls (rolls in the shape of toilet paper), and can cut | disconnect according to required length.

[0031] Fig. 7 to Fig. 10 illustrate product patterns (usage status) of the radio wave shield 1 according to the present embodiment. FIG. 7 is a cross-sectional view showing a state in which the radio wave shield 1 is attached to the wall 30 on the base material 10 side. In this case, the radio wave shield 1 is the base material 10 of the radio wave shield 1. It is attached to the wall 30 by the adhesive 31 provided on the side. FIG. 8 shows a schematic diagram of the radio wave shield 1 in which the adhesive 31 and the protective film 32 are formed on the substrate 10 side and are rolled in the form of toilet paper. In this case, the radio wave shield 1 is cut according to the required length. The protective film 32 can be peeled off and attached to a wall or the like. On the other hand, FIG. 9 is a cross-sectional view showing a state in which the radio wave shield 1 is adhered to the wall 30 on the reflective layer 12 side. In this case, the adhesive 31 is reflected from the radio wave shield 1. It is provided on the layer 12 side. FIG. 10 is a schematic diagram of the radio wave shield 1 in which the pressure-sensitive adhesive 31 and the protective film 32 are formed on the reflective layer 12 side and rolled in the form of toilet paper. In this case, the radio wave shield 1 is cut according to the required length. The protective film 32 can be peeled off and adhered to a wall or the like. Note that the base material 10 has various properties (light transmissibility, non-flammability, flame retardancy, etc.) as well as just a role as a base material (for example, a role to ensure the mechanical durability of the radio wave shield 1). It is particularly preferred that it plays a role of imparting non-halogenity, flexibility, impact resistance, heat resistance, etc.) to the radio wave shield.

In the present embodiment, the reflective layer 12 selectively reflects radio waves having a specific frequency. Is. Specifically, the reflective layer 12 includes a plurality of antennas 13 that are two-dimensionally arranged to form a pattern. Each antenna 13 selectively reflects radio waves having a specific frequency. The plurality of antennas 13 are formed by applying a radio wave reflecting material (preferably in a liquid state).

[0033] The coating film 11 is formed on the surface of the substrate 10 having a plurality of fine holes so as to cover the surface. The coating film 11 has a radio wave reflecting material (for example, a radio wave reflecting liquid material) for forming the antenna 13 described in detail later on the base material 10 (a radio wave reflecting material toward the surface of the base material (for example, a radio wave reflecting liquid) (Impregnation of the material)) and the unintentional spread of the radio wave reflecting material (for example, radio wave reflecting liquid material) on the surface of the base material 10 is suppressed. The coating film 11 is preferably one that densifies and flattens the surface of the substrate 10 having at least one of a plurality of fine holes and a plurality of irregularities (for example, porous). In addition, it is preferable that the surface of the base material 10 is densified and flattened and the thickness of the base material 10 is made uniform. Further, it is preferable that the coating film 11 is a material that is low in swelling property with respect to a radio wave reflecting material (for example, radio wave reflecting liquid material) (a material that is difficult to be impregnated with a radio wave reflecting material (for example, radio wave reflecting liquid material)). For example, the coating film 11 can be formed of resin (for example, urethane resin, acrylic resin, polyester resin, etc.).

Next, a method for manufacturing the radio wave shield 1 according to the present embodiment will be described. First, the coating film 11 is formed on the substrate 10. Specifically, the surface of the substrate 10 having at least one of a plurality of fine holes and a plurality of irregularities is flattened (that is, the surface is smoothed and the entire thickness (substrate 10 + coating film The coating film 11 is formed so that the thickness (11) is uniform. The coating film 11 can be formed by, for example, a roll coater method, a slit die coater method, a doctor knife coater method, or a gravure coater method.

[0035] After the coating film 11 is formed, the radio wave shield 1 is completed by producing the antenna 13 and forming the reflective layer 12 using a radio wave reflecting material (for example, a liquid radio wave reflecting material). Specifically, for example, the reflective layer 12 is formed by applying a liquid radio wave reflecting material, drying, and firing as necessary to produce a plurality of antennas 13. The application of the radio wave reflecting liquid material is mist coating method, silk printing method, spin coating method, doctor blade method, discharge coating method, spray coating method, ink jet method, letterpress printing method, intaglio printing method, screen printing method. The microgravure coating method can be used.

[0036] For example, when a liquid radio wave reflecting material is applied directly to the surface of the base material 10 without forming the coating film 11, micropores exist on the surface of the base material 10, and therefore, due to capillary action. Thus, the base material 10 is impregnated with the radio wave reflecting liquid material (the liquid radio wave reflecting material is impregnated toward the base material surface). As a result, the liquid radio wave reflecting material is blurred. Therefore, it is very difficult to manufacture the antenna 13 having a desired shape and size. In detail, when the liquid radio wave reflecting material is spread, the shape of the formed antenna 13 becomes broad (for example, when the antenna 13 is a linear antenna, the line width is wider than the design value, And it will shake.) In addition, variations in the shape and dimensions of the antenna occur. Specifically, when the TY-shaped antenna 13 shown in the present embodiment is formed, variations occur in the length of the first element portion 13a and the length of the second element portion 13b. In addition, part of the antenna 13 may be cut (electrically).

[0037] In addition, since the surface of the substrate 10 has irregularities, the liquid radio wave reflection material unintentionally flows from the convex part into the adjacent concave part, or the liquid radio wave reflective material is concentrated in the concave part. Therefore, it becomes difficult to manufacture the antenna 13 having a desired shape and size. That is, there is a possibility that the shape and size of the antenna 13 obtained may vary, or that the shape and size of the antenna 13 may be different from the desired shape.

[0038] For example, it is conceivable to form the antenna 13 on the base material 10 by using a dry method such as a sputtering method. In this case, although there is no problem such as bleeding of the liquid radio wave reflecting material, a large facility Is required, the manufacturing cost is increased, and the manufacturing process is complicated.

On the other hand, in this embodiment, the surface of the substrate 10 is coated with the coating film 11 and is V. The coating film 11 fills the fine pores and recesses present on the surface of the substrate 10, and the surface is flattened. Therefore, bleeding (impregnation, particularly impregnation of the liquid radio wave reflection material in the surface direction of the base material 10) of the liquid radio wave reflection material and unintended flow of the liquid radio wave reflection material are suppressed. Therefore, a shading method using a liquid radio wave reflecting material that does not require a large facility or the like and can be easily and inexpensively performed is used. A plurality of antennas 13 having a small shape and little variation in shape dimensions (for example, when the antenna 13 is a linear antenna, the line width is substantially equal to the design value and the line width is stable. An antenna 13) having a stable part length can be formed. That is, the radio wave shield 1 according to the present embodiment can be easily and inexpensively manufactured and has high radio wave shielding properties.

[0040] The liquid radio wave reflecting material is a liquid or paste in which fine particles or colloids substantially made of a radio wave reflecting substance such as a conductive substance are dispersed and mixed (hereinafter sometimes referred to as "conductive paste"). Or a solution in which a radio wave reflecting material is melted.

[0041] Examples of the conductive material include aluminum, silver, copper, gold, platinum, iron, carbon, graphite, indium tin oxide (ITO), indium zinc oxide (IZO), a mixture or an alloy thereof. . Among these, it is preferable that the antenna 13 includes at least one of copper, aluminum, and silver having high conductivity and relatively inexpensive.

[0042] On the other hand, examples of the medium containing a conductive material include a resin (eg, polyester resin) and a solvent.

(Organic solvent, water, etc.). When fine particles containing conductive material are dispersed and mixed in the resin, it is preferable that the content of the conductive material is not less than 40% by weight and not more than 80% by weight. More preferably, the content of the conductive material is not less than 50 weight percent and not more than 70 weight percent. If the content of the conductive material is less than 40 weight percent, the conductivity of the antenna 13 tends to decrease. On the other hand, when the content of the conductive material is more than 80 weight percent, it tends to be difficult to uniformly disperse and mix it in the resin. Resin is made of conductive material

It may also serve as an adhesive that bonds the substrate 10.

[0043] The drying (firing) conditions of the applied liquid radio wave reflective material can be determined as appropriate depending on the composition of the liquid radio wave reflective material, for example, 100 ° C to 200 ° C and 10 minutes to 5 hours. This is better to dry.

[0044] In the case where the antenna 13 includes a material that is relatively easily oxidized, such as silver.

Further, an anti-oxidation film may be formed on the antenna 13 so as to cover the antenna 13.

[0045] Next, the configuration of the reflective layer 12 in the present embodiment will be described in more detail. In this embodiment, the reflective layer 12 has frequency selectivity arranged in a matrix at equal intervals. The plurality of antennas 13 are configured. That is, the antenna 13 selectively reflects radio waves having a specific frequency. For this reason, the radio wave shield 1 can selectively shield radio waves of a specific frequency and transmit other radio waves.

Specifically, as shown in FIG. 4, the antenna 13 has three first element portions 13a and three second element portions 13b. The three first element portions 13a extend outward from the antenna center C1 at an angle of 120 ° to each other.

[0047] Each second element portion 13b is coupled to the outer end of the first element portion 13a. The lengths of the first element portions 13a are preferably substantially the same. The lengths of the second element portions 13b are preferably substantially the same. By doing so, the frequency selectivity of the reflective layer 12 can be made higher.

[0048] Note that the length (L1) of the first element portion 13a and the length (L2) of the second element portion 13b may be different from each other (L1 ≠ L2) (L1 = L2). ). It is preferable that the length (L1) of the first element portion 13a and the length (L2) of the second element portion 13b satisfy the relational expression of 0 <L2 2 (3) ^1/2 ZL1. If L2 is 2 (3) ^1/2 ZL1 or more (L2≥2 (3) ^1/2 / L1), the adjacent second element parts 13b come in contact with each other, and the desired radio wave shielding effect It is because it becomes impossible to obtain. From the viewpoint of realizing a high specific frequency and shielding rate, the length (L2) of the second element portion 13b is not less than 0.5 times and not more than 2.0 times the length (L1) of the first element portion 13a (0 5'L1≤L2≤2'L1) is preferred. More preferably, it is from 0.75 times to 2 times (0.75'L1≤L2≤2'L1). On the other hand, the width of the first element portion 13a and the width of the second element portion 13b may be different from each other or the same. In the present embodiment, the width of the first element portion 13a and the width of the second element portion 13b are substantially the same width (L3).

[0049] As described above, the antenna 13 includes the three second element portions 13b coupled to the outer ends of the first element portions 13a. For this reason, the antenna 13 is a “Y” -shaped linear antenna (a linear antenna including only the three first element portions extending radially of the antenna central force and having no second element portion), or a so-called antenna. Jerusalem cross-type antennas (each having four line-shaped first element portions extending radially at substantially the same length from each other at an angle of 90 ° from the center of the antenna, and the outer ends of the first element portions) Line segments connected to The antenna has a higher frequency selectivity than the antenna having the second element portion. Therefore, the radio wave shield 1 having high frequency selectivity can be realized.

[0050] Since the antenna 13 includes the second element portion 13b, the second element portions 13b are opposed to each other between the adjacent antennas 13, 13 (more preferably, the second elements facing each other). It is easy to place a plurality of antennas 13 by placing the parts 13b close to each other (however, the distance dimension between both the second element parts 13b and 13b ≠ 0). This can improve the radio wave shielding rate against radio waves of a specific frequency, especially when the second element part 13b is in close contact with the liquid radio wave reflection material and the unintentional liquid radio wave reflection material. If flow occurs, the opposing second element parts 13b may be connected to each other, and if the second element parts 13b are connected to each other, desired radio wave shielding characteristics (radio wave shielding rate and frequency selectivity) can be obtained. Et For this reason, the coating film 11 can be provided particularly when the second element portions 13b of the antenna 13 located adjacent to each other are arranged so as to face each other (more closely). It is valid.

[0051] From the viewpoint of making the second element portions 13b face each other and disposing more antennas 13 per unit area, the second element portion 13b is coupled to the outer end of the first element portion 13a at the center, Further, it is preferable that the second element portion 13b and the first element portion 13a form a right angle. Further, it is preferable that the length of the second element portion 13b and the length of the first element portion 13a are substantially the same.

[0052] The length of the first element portion 13a and the length of the second element portion 13b correlate with the frequency (specific frequency) of the radio wave to be reflected by the antenna 13. For this reason, the length of the first element portion 13a and the length of the second element portion 13b can be appropriately determined according to the frequency (specific frequency) of the radio wave to be shielded by the radio wave shield 1. For example, when the length of the first element portion 13a is the same as the length of the second element portion 13b, the specific frequency is lowered by increasing the length of the first element portion 13a and the second element portion 13b. It can be made. Further, the specific frequency can be increased by reducing the lengths of the first element portion 13a and the second element portion 13b.

[0053] Hereinafter, the length L1 of the first element portion 13a and the length L2 of the second element portion 13b are the same. (Hereinafter, “L1” and “L2” are collectively referred to as the element length L.) The radio wave shielding characteristics of the radio wave shield 1 will be described in detail with reference to FIGS. Fig. 11 is a characteristic diagram showing the relationship between the frequency of radio waves and the transmission attenuation of radio waves when passing through the radio wave shield 1. In the example shown, the lengths L1 and L2 are both 10.6 mm (Ll = L2 = 10.6 mm) and the width L3 is 0.7 mm (L3 = 0.7 mm).

As shown in FIG. 11, the transmittance of radio waves having a specific frequency (about 2.7 GHz) among radio waves incident on the radio wave shield 1 is selectively attenuated. In other words, the radio wave shield 1 selectively shields radio waves having a specific frequency among radio waves incident on the radio wave shield 1. This is because the radio wave of the specific frequency is selectively reflected among the radio waves incident on the reflection layer 12 of the radio wave shield 1, specifically, the plurality of antennas 13 included in the reflection layer 12. The frequency of the radio wave reflected by the antenna 13 is determined by the length LI (= L) of the first element portion 13a and the length L2 (= L) of the second element portion 13b.

FIG. 12 is a characteristic diagram showing the relationship between the element length L and the frequency of the radio wave reflected by the antenna 13. As can be seen from this figure, the frequency of the radio wave reflected by the antenna 13 decreases as the element length L increases. On the contrary, the frequency of the radio wave reflected by the antenna 13 becomes higher as the element length L becomes shorter.

[0056] On the other hand, the frequency of the reflected radio wave does not greatly correlate with the width L3. That is, the frequency of the reflected radio wave is mainly determined by the element length L. Therefore, based on the relationship between the element length L and the selected frequency as shown in FIG. 12, the element length L can also be calculated and determined for the V reflected by the antenna 13 and the frequency (specific frequency) force of the radio wave. For example, when creating radio wave shield 1 that shields radio waves with a frequency of 5 GHz, it can be seen from Fig. 12 that the element length L should be about 6 mm (L = 6 mm)!

[0057] For example, the specific frequency can be adjusted by fixing the length L1 of the first element portion 13a and adjusting the length L2 of the second element portion 13b. Specifically, the specific frequency can be lowered by increasing the length L2 of the second element portion 13b. Further, the specific frequency can be increased by shortening the length L2 of the second element portion 13b.

[0058] The thickness of the antenna 13 is preferably 10 μm or more and 20 μm or less (10 to 20 μm). That's right. If the thickness of the antenna 13 is smaller than 10 / zm, the conductivity of the antenna 13 tends to decrease. On the other hand, when the thickness of the antenna 13 is larger than 20 m, the formability of the antenna 13 tends to be lowered.

As described above, the radio wave shield 1 according to the present embodiment has been described in detail, but the shape and size of the radio wave shield 1 is not limited at all. The radio wave shield 1 may be a small one with a length of several millimeters square on one side or a large one with a few meters or more on one side.

[0060] In addition, the radio wave shield 1 may have any shape such as a triangle, a quadrilateral (rectangle, square), a polygon, a circle, an ellipse, or the like in plan view.

Further, the number of antennas 13 included per unit area of the radio wave shield 1 is not limited at all. The number of antennas 13 included per unit area of the radio wave shield 1 can be appropriately changed depending on the use of the radio wave shield 1 and the like. By increasing the number of antennas 13 included per unit area of the radio wave shield 1, high radio wave shielding can be realized.

[0062] In the present invention, the shape, dimensions, and the like of the antenna constituting the reflective layer 12 are not particularly limited, and the antenna 13 described here is merely an example. In addition, the reflective layer 12 may include a plurality of antennas 13 and one or a plurality of types of antennas having different shape dimensions from the antenna 13! /.

Hereinafter, as a modification of the present embodiment, various radio wave shields having different configurations of the reflective layer 12 (the shape and arrangement of the antenna 13) will be described.

[Variation 1]

FIG. 13 is a plan view of the reflective layer 12a in Modification 1, and FIG. 14 is an enlarged plan view of a part of the reflective layer 12a.

In the first modification, the reflection layer 12 is arranged so that a plurality of antennas 13 constitute a plurality of antenna assemblies 15 arranged in a matrix at predetermined intervals. Specifically, each of the plurality of antennas 13 constitutes a plurality of antenna units 14 having a pair of forces and disposed so that the second element portions 13b face each other, and further, the plurality of antenna units 14 Are arranged so that the second element parts 13b face each other and are continuous in two dimensions. A plurality of hexagonal antenna assemblies 15 are formed. That is, each antenna assembly 15 includes three antennas arranged in a ring shape with the second element portions 13b facing each other.

14 In other words, the antenna assembly 15 includes six antennas 13 arranged in a ring shape with the second element portions 13b facing each other.

[0066] As in Modification 1, particularly when the second element portion 13b is closely opposed, if the liquid radio wave reflecting material bleeds or an unintentional flow of the liquid radio wave reflecting material occurs, the second element portion 13b faces. There is a possibility that the second element portions 13b are connected to each other. If the second element portions 13b are connected to each other, desired radio wave shielding characteristics (radio wave shielding rate and frequency selectivity) cannot be obtained. For this reason, it is particularly effective to provide the coating film 11 in the case where the second element portions 13b of the antenna 13 located adjacent to each other are arranged facing each other (more closely facing each other).

In the first modification, 12 second element portions 13b among the 18 second element portions 13b constituting the antenna assembly 15 are provided so as to face each other substantially in parallel. Thus, by arranging and configuring the antenna 13 so that a relatively large number of the second element portions 13b face each other, the radio wave reflectance (radio wave shielding rate) of the antenna 13 with respect to radio waves of a specific frequency is further improved. be able to. Therefore, it is possible to realize a radio wave shielding body having a high radio wave shielding rate with respect to radio waves of a specific frequency.

[0068] Note that the shorter the distance XI between the opposing second element portions 13b, the higher the radio wave reflectivity of the antenna (the radio wave shield rate of the radio wave shield). Specifically, it is preferable that the distance XI (see FIG. 14) between the opposing second element portions 13b is 0.4 mm or more and 3 mm or less (0.4 mm≤Xl≤3mm). 0.6 mm or more and lmm or less (0.6 mm ≤ XI ≤ lmm). Incidentally, if the distance XI is shorter than 0.4 mm (XI <0.4 mm), the opposing second element parts 13b may contact each other undesirably, while the distance XI is longer than 3 mm (XI> 3mm). ) And the radio wave shielding rate tends to decrease.

[0069] From the viewpoint of realizing constant radio wave shielding against radio waves incident at various incident angles, the antenna assembly 15 is preferably hexagonal (preferably substantially regular hexagonal). Accordingly, it is preferable that the first element portion 13a and the second element portion 13b are perpendicular to each other. Good. Further, it is preferable that the second element portion 13b is coupled to the first element portion 13a at the center thereof.

[0070] (Modification 2)

FIG. 15 is a plan view of the reflective layer 12b in the second modification.

[0071] In the second modification, the antenna assembly 15 is arranged so that the second element portions 13b are opposed to each other (in a so-called “Harcam” shape). For this reason, in the second modification, all the second element portions 13b face each other. As described above, by disposing the antenna 13, it is possible to increase the number of second element portions 13 b provided so as to face each other more than in the first modification. For this reason, a radio wave shield having a higher radio wave shielding rate can be realized.

[0072] In the case of the antenna arrangement as in the second modification example, if the liquid radio wave reflection material bleeds or an unintended flow of the liquid radio wave reflection material occurs and the opposing second element parts 13b come into contact with each other, As a result, the reflective layer 12 may have little frequency selectivity. Therefore, the coating film 11 is very effective even in the case of the antenna arrangement in the second modification.

[Modification 3]

FIG. 16 is a plan view of the reflective layer 12c in the third modification.

[0074] In the example shown in Fig. 1 and the examples of Modifications 1 and 2, the reflection layer is composed of only one type of antenna, whereas in Modification 3, there are multiple types of reflection layer 12c. It is composed of antennas. Specifically, the reflective layer 12c has two types of antennas 16, 17 including a relatively small antenna 16 and a plurality of relatively large antennas 17. Each of the antenna 16 and the antenna 17 is a so-called TY antenna.

[0075] The plurality of antennas 16 and the plurality of antennas 17 are arranged in an alternating pattern and in a matrix so as not to interfere with each other. The antenna 16 and the antenna 17 may be similar to each other or may be non-similar. Further, the reflective layer 12c may further include an antenna other than the antenna 16 and the antenna 17.

[0076] The relatively small antenna 16 and the relatively large antenna 17 have mutually different frequency selectivity. That is, the frequencies of the reflected radio waves are different from each other. others Therefore, according to the third modification, it is possible to realize a radio wave shield capable of selectively shielding two types of radio waves having different frequencies.

[0077] For example, in the wireless LAN, the radio wave shielding body according to the third modification uses radio waves of two types of frequency, 2.4 GHz band radio waves and 5.2 GHz band radio waves. Yes. This is especially useful in environments where wireless LAN is used and environments where radio waves of two different frequencies are used.

[0078] In an environment where radio waves of three or more types of frequencies are used, the reflective layer 12c may be configured by three or more types of antennas having different sizes.

[0079] (Modification 4)

FIG. 17 is a plan view of the reflective layer 12d in Modification 4.

[0080] In the fourth modification, like the plurality of antennas 13 in the second modification, each of the plurality of antennas 16 has a plurality of force pairs that are arranged so that the second element portions 16b face each other. The antenna unit 18 is configured, and the plurality of antenna units 18 are arranged so that the second element portions 16b are opposed to each other, and a plurality of hexagonal antenna assemblies 19 that are continuously developed in two dimensions are provided. It is composed. In other words, each antenna assembly 19 includes three antenna units 18 arranged in a ring shape with the second element portions 16b facing each other. In other words, the antenna assembly 19 includes six antennas 13 arranged in an annular shape with the second element portions 16b facing each other. The antenna assembly 19 is further arranged so as to face the second element portions 13b (in a so-called “Hercam” shape).

On the other hand, the plurality of antennas 17 constitutes a plurality of antenna units 20 each having a pair of forces arranged so that the second element portions 17b face each other, similarly to the plurality of antennas 13 in Modification 1. In addition, the plurality of antenna units 20 constitutes a plurality of hexagonal antenna assemblies 21 that are arranged so that the second element portions 17b face each other and are continuously developed in two dimensions. Each antenna assembly 21 is arranged so as to be surrounded by the antenna assembly 19. According to such an arrangement, the second element portions 16b of the antenna 16 and the second element portions 17b of the antenna 17 are opposed to each other with a high probability, and both the antennas 16 and 17 have substantially the same density. Can be arranged. Therefore, both the radio wave reflected by the antenna 16 and the radio wave reflected by the antenna 17 are more It is possible to shield with high frequency selectivity and higher shielding rate.

[0082] In the case of Modification 4, as in the case of Modification 1 and Modification 2, if the liquid radio wave reflecting material bleeds or the unintended flow of the liquid radio wave reflecting material occurs, the opposing second Since the element part 13b may come into contact with each other and the desired radio wave shielding characteristics may not be obtained, the coating film

It is effective to form 11.

[0083] In Modification 4, it is preferable that the lengths of the second element portions 16b and 17b are relatively short. By doing so, contact between the antenna 16 and the antenna 17 can be suppressed. Therefore, the dimensional freedom of the antenna 17 constituting the antenna assembly 21 surrounded by the antenna assembly 19 can be further increased. As a result, for example, a radio wave shield capable of selectively shielding two types of radio waves having relatively close frequencies can be realized.

[0084] (Modification 5)

FIG. 18 is a plan view of the reflective layer 12e in Modification 5.

This Modification 5 is a further modification of Modification 4 described above. In Modification 5, the antenna assembly 19 and the antenna assembly 21 are inclined with respect to each other so as to have different symmetry axes (specifically, line symmetry axes extending in the arrangement direction of the antennas 16 and 17). Are arranged as follows.

In order to surround the antenna assembly 21 with the antenna assembly 19, it is necessary to make the dimensions of the antenna 17 constituting the antenna assembly 21 smaller than the dimensions of the antenna 16 constituting the antenna assembly 19. As shown in Modification 4, when antenna assembly 19 and antenna assembly 21 are arranged without being inclined, antenna 16 and antenna 17 are not interfered with each other so that antenna 16 and antenna 17 do not interfere with each other. Therefore, the design flexibility of the antenna 16 and the antenna 17 is reduced.

On the other hand, as shown in the fifth modification, when the antenna assembly 19 and the antenna assembly 21 are arranged with an inclination (for example, 0 = 10 ° in FIG. 18), they face each other. The relative positions of the second element portion 16b and the second element portion 17b facing each other are shifted. For this reason, in the fifth modification, compared to the case shown in the fourth modification, the relative size of the antenna 17 with respect to the antenna 16 can be made relatively large. Therefore, antenna 16 and antenna 1 The degree of freedom in designing the shape dimensions with 7 can be expanded. As a result, it is possible to shield the two waves that are close in frequency (ratio of the first frequency to the second frequency (first frequency <second frequency) is 0.45 or more).

Further, in FIG. 18, the substantially hexagonal antenna assembly 19 and the antenna assembly 21 are arranged in a close-packed manner, but depending on a desired radio wave shielding rate, they are not arranged in a close-packed manner, but in a substantially hexagonal shape. Adjust the number of antenna assemblies 19 and 21 as appropriate.

[0089] (Modification 6)

In Modification 6, an example will be described in which the reflection layer is configured by a plurality of types of antennas that selectively reflect radio waves of different specific frequencies so that radio waves of specific frequency bands can be selectively shielded. Specifically, an example in which the reflective layer 12f is configured by three types of antennas 22a, 22b, and 22c will be described.

[0090] "Frequency band" refers to a frequency range where the ratio band exceeds 10%. A radio wave shield that selectively shields radio waves in a specific frequency band is a radio wave shield that has a 10 dB ratio band (preferably a 20 dB ratio band, more preferably a 30 dB ratio band) exceeding 10%. It means the body. On the other hand, a radio wave shield that “selectively blocks radio waves of a specific frequency” refers to a radio wave shield with a 10 dB ratio band of 10% or less. The 10dB bandwidth is 10dB or more, where F is the maximum frequency of the radio wave that is shielded by 10dB or more.

max

Blocking

If the minimum frequency of the radio wave to be covered is F, 2 (F — F) / (Y + F)

mm max min max min Expressed.

Hereinafter, the configuration of the reflective layer 12f in Modification 6 will be described in detail with reference to FIG. FIG. 19 is a plan view of the reflective layer 12f.

[0092] The reflection layer 12f includes a plurality of types of antennas 22 that selectively reflect radio waves having different specific frequencies, specifically, the first antenna 22a, the second antenna 22b, and the third antenna 22c. It is composed of different types of antennas. The first antenna 22a, the second antenna 22b, and the third antenna 22c have their respective radio wave reflection spectrum peaks that are not independent of each other. In other words, each radio wave reflection spectrum peak is continuous. For this reason, the reflective layer 12f according to this modification has a frequency having a predetermined width. Radio waves in a band (for example, a frequency band from 815 MHz to 925 MHz) can be selectively reflected. For example, the reflective layer 12f has a radio wave shielding characteristic (radio transmission attenuation characteristic) as shown in FIG. From the viewpoint of achieving higher continuity of the radio wave reflection spectrum peak, the size of each antenna 22 included in the reflection layer 12f is ± 15% of the size of the reference type antenna 22 of the antennas 22 (preferably ± 10%, more preferably within ± 5%).

FIG. 20 is a graph illustrating the correlation between the radio wave shielding amount (radio wave transmission attenuation amount) of the reflective layer 12f and the frequency. As shown in the figure, the spectrum peak P2 of the first antenna 22a, the spectrum peak P3 of the second antenna 22b, and the spectrum peak P1 of the third antenna 22c are not independent of each other and are continuous. . In other words, the ratio of the depth H2 from the base line BL of the valley to the depth HI from the base line BL of P1, which is the largest peak, is 50% or less (3 dB or more). According to the reflection layer 12f, the radio waves in the entire frequency band between the peaks P1 to P3 are shielded (reflected) with a high shielding rate of 10 dB or more. It is also preferable that the 10 dB bandwidth is greater than 10%.

[0094] "Radio reflection spectrum peaks are independent of each other (continuously! /, Ru)" means that the largest spectrum of radio wave reflection (shielding) spectra of an electromagnetic shield is present. The ratio of the minimum radio wave reflection (shielding) rate in the valley between the spectral peaks to the radio wave reflection (shielding) rate of the peak (peak) is greater than 50% (the peak (peak) radio wave with the largest spectrum) The difference between the reflection (shielding) rate and the minimum radio wave reflection (shielding) rate in the valley is less than 3 dB). On the other hand, “radiowave reflection spectrum peaks are independent of each other (not continuous)” means that the radio wave at the peak (peak) of the largest spectrum of the radio wave shielding spectrum (radio wave reflection spectrum) of the radio wave shield. The ratio of the minimum radio wave reflection (shielding) rate at the valley between the spectral peaks to the reflection (shielding) rate is 50% or less The difference from the radio wave reflection (shielding) rate is 3 dB or more).

In Modification 6, each of the first antenna 22a, the second antenna 22b, and the third antenna 22c is the TY antenna described above. However, each of the first antenna 22a, the second antenna 22b, and the third antenna 22c is, for example, a “Y” -shaped antenna, so-called Elsa. It may be a remcross type antenna or the like. Further, the first antenna 22a, the second antenna 22b, and the third antenna 22c may be antennas having different shapes from each other or may be similar to each other.

[0096] Next, the arrangement of the antenna 22 in Modification 6 will be described in detail. As shown in FIG. 19, the reflective layer 12f includes a plurality of first antennas 22a, a plurality of second antennas 22b, and a plurality of third antennas 22c, which are respectively a first antenna 22a, a second antenna 22b, and a first antenna. 3 The antennas 22c are two-dimensionally arranged so as to form a plurality of antenna rows 23 that are alternately arranged in this order in the negative direction. In other words, the reflective layer 12f is formed by arranging a plurality of antenna arrays 23 in which the first antenna 22a, the second antenna 22b, and the third antenna 22c are alternately arranged in this order in the negative direction. is there.

In the reflective layer 12f, each first antenna 22a is adjacent to the second antenna 22b and the third antenna 22c belonging to the antenna row 23 adjacent to the antenna row 23 to which the first antenna 22a belongs. Similarly, each second antenna 22b is adjacent to the first antenna 22a and the third antenna 22c belonging to the antenna row 23 adjacent to the antenna row 23 to which the second antenna 22b belongs. Each third antenna 22c is adjacent to the second antenna 22b and the first antenna 22a belonging to the antenna row 23 adjacent to the antenna row 23 to which the third antenna 22c belongs. In other words, the antenna center of the first antenna 22a and the first antenna 22a adjacent to the first antenna 22a belonging to the antenna array 23 located on both sides of the antenna array 23 to which the first antenna 22a belongs is triangular (preferably Are arranged to form an equilateral triangle). The antenna center of the first antenna 22a and the second antenna 22b adjacent to the second antenna 22b belonging to the antenna array 23 located on both sides of the antenna array 23 to which the second antenna 22b belongs is a triangle ( Preferably, they are arranged to form an equilateral triangle. The antenna center between the first antenna 22a and the third antenna 22c adjacent to the third antenna 22c belonging to the antenna array 23 located on both sides of the antenna array 23 to which the third antenna 22c belongs is triangular (preferably Are arranged to form an equilateral triangle).

[0098] With this arrangement, for example, a plurality of second elements 22a of the first antenna 22a are inserted between the second antenna 22b and the third antenna 22c belonging to the adjacent antenna row 23. The antenna columns 23 can be densely arranged in the row direction. In other words As shown in FIG. 19, the antennas 22 can be densely arranged in such a manner that the second element portion of the adjacent antenna 22 enters the region R where the second antenna 22b is arranged. Therefore, more antennas 22a, 22b, and 22c can be arranged more closely per unit area.

[0099] Here, the radio wave shielding rate correlates with the number of antennas 22 per unit area, and as the number of antennas 22 per unit area increases, the radio wave shielding rate also increases. According to the arrangement of the antenna 22, a high radio wave shielding rate can be realized. In addition, since the number of the first antenna 22a, the second antenna 22b, and the third antenna 22c included in the unit area can be made substantially the same, it is possible to suppress radio wave shielding unevenness in the frequency band. From the viewpoint of increasing the number of antennas 22 per unit area, the second element portion is preferably shorter than the first element portion (L2> L1).

[0100] Further, in the arrangement of the antennas 22 in Modification 6, the plurality of antennas 22 are arranged so that the second element portions do not face each other in parallel. For this reason, the frequency selectivity of the antenna 22 can be kept relatively low. In other words, the specific band of the antenna 22 can be kept relatively wide. Therefore, it is possible to realize a favorable radio wave shielding rate with little bias to radio waves in the entire specific frequency band.

[0101] In the case of the antenna arrangement in Modification 6, the second element portions of the antennas 22 arranged adjacent to each other are not opposed to each other. For this reason, it is unlikely that the second element portions 13b of the antennas 22 arranged adjacent to each other contact each other. High electromagnetic shielding characteristics

In particular, when the number of antennas 22 included per unit area is increased by arranging closely the antennas 22 that realize the above, the first element part and the second element part of the adjacent antenna are in contact with each other. As a result, the desired radio wave shielding characteristics may not be obtained. In addition, the reflective layer 12f in Modification 6 reflects radio waves in a specific frequency band, and has a frequency selectivity lower than that of the reflective layer described in Embodiment 1 etc. If the length of the element part varies or the length of the second element part varies, the desired frequency selectivity cannot be obtained. Therefore, it is effective to provide the coating film 11 even in the case of the antenna arrangement as in Modification 6. Is.

[0102] (Variation 7)

The example of the reflective layer 12 configured by the TY antenna has been described above. However, the reflective layer 12 may be configured by an antenna other than the TY antenna. For example, as shown in FIG. 21, the reflective layer 12g may be composed of a plurality of “Y” -shaped antennas 24 arranged in a matrix. Each antenna 24 is constituted by three line-shaped first element portions 24a extending radially at substantially the same length at an angle of 120 ° from the antenna center.

[0103] As described above, even when the "Y" -shaped antenna is arranged, if the liquid radio wave reflecting material bleeds or the unintended flow of the liquid radio wave reflecting material occurs, the first element portion Since the length of 24a varies, the desired radio wave shielding characteristics cannot be obtained. Therefore, it is effective to provide the coating film 11 even when “Y” -shaped antennas are arranged like the reflective layer 12g.

[Variation 8]

The present modification 8 is a further modification of the modification 7. In Modification 7 above, the reflective layer 12 2g is composed of only one type of antenna 24, whereas in Modification 8, the reflective layer 12h has two types of “Y” characters with different sizes. The antennas 25 and 26 are used. According to this configuration, it is possible to realize a radio wave shield that can shield multiple types of radio waves having different frequencies.

As shown in FIG. 22, in Modification 8, relatively large antennas 25 are arranged so that the first element portions face each other. Specifically, the first element parts of different antennas 25 are arranged in parallel and densely in each of the three first element parts of an antenna 25. One relatively small antenna 24 is disposed in each of the hexagonal regions defined by the relatively large antenna 25. By adopting such an arrangement, it is possible to improve the radio wave shielding rate of the antenna 25 against radio waves of a specific frequency.

[0106] In the case of Modification 8, since the first element portions of the antenna 25 are closely opposed to each other, the liquid radio wave reflection material may spread out and the liquid radio wave reflection material may flow unintentionally. The antennas 25 in contact with each other are likely to come into contact with each other. Therefore, in the case of the antenna arrangement as in Modification 8, it is particularly effective to provide the coating film 11.

[0107] (Modification 9)

FIG. 23 is a plan view of the reflective layer 12i in Modification 9.

In the tenth embodiment, the reflective layer 12i is composed of a plurality of so-called Jerusalem cross-type antennas 27. Each antenna 27 has four linear first element portions 27a extending radially with substantially the same length at an angle of 90 ° to each other, and the outer end of each first element portion. Line-shaped second element connected to each other (typically vertically)

27b. By configuring the reflective layer with the antenna 27 having such a shape, a frequency selectivity higher than that in the case where the reflective layer is configured with the “Y” -shaped antenna described in the modified examples 7 and 8 (however, the so-called Τ —Frequency selectivity lower than in the case where the reflecting layer is formed by a saddle type antenna can be realized.

The plurality of antennas 27 are arranged in a matrix so that the second element portions 27b of the adjacent antennas 27 face each other (preferably so as to face each other in parallel and densely). According to this arrangement, it is possible to further improve the radio wave shielding rate of the antenna 27 with respect to radio waves of a specific frequency.

[0110] As described above, even when the Jerusalem cross-type antenna is arranged, each of the element portions is similar to the case where the T-Y antenna and the "Y" -shaped antenna are arranged. If the length varies, a desired radio wave shielding characteristic cannot be obtained. Therefore, it is effective to provide the coating film 11 even when the Jerusalem cross-type antenna is arranged like the reflective layer 12i.

[0111] (Modification 10)

FIG. 24 is a plan view of the reflecting layer 1¾ in the modified example 10.

[0112] The present modification 10 is a further modification of the modification 9. In Modification 9 above, the reflection layer 12i is composed of only one type of antenna 27, whereas in this Modification 10, the reflection layer 12j has two types of Jerusalem cross-type antennas having different sizes. It consists of 28 and 29. According to this configuration, it is possible to shield a plurality of types of radio waves having different frequencies. It is possible to realize a radio wave shield capable of.

[0113] As shown in Fig. 24, in Modification 10, the plurality of antennas 28 are arranged so that the second element portions 28b of the antennas 28 arranged adjacent to each other face each other (preferably in parallel and densely). Are arranged in a matrix). One relatively small antenna 29 is arranged in each of the areas partitioned by the relatively large antenna 28.

[0114] With such an arrangement, it is possible to improve the radio wave shielding rate with respect to radio waves of a specific frequency of the antenna 28.

[0115] In the case of the antenna arrangement as in Modification 10, if the liquid radio wave reflecting material bleeds or the unintentional flow of the liquid radio wave reflecting material occurs, the second element part 28b arranged in close contact with each other comes into contact with each other. There is a risk of it. In addition, the second element portion 28b of the antenna 28 and the second element portion 29b of the antenna 29 that are close to each other may come into contact with each other. Therefore, it is effective to provide the coating film 11 even in the case of the antenna arrangement as in the modification 10.

[0116] (Modification 11)

FIG. 25 is a plan view of the reflective layer 12k in Modification 11.

[0117] This modification 11 is a further modification of the modification 10 in which only the arrangement of the antennas 28 and 29 is different.

[0118] In Modification 11, in the same direction as the array of antennas 28 arranged so that the second element portions 28b face each other in the lateral direction in FIG. 25 (preferably, face in parallel and densely). The rows of antennas 29 arranged in such a manner that the second element portions 29b face each other (preferably in parallel and close to each other) and the force are alternately arranged in the vertical direction in FIG. this

By arranging in this way, it is possible to improve the radio wave shielding rate against radio waves of specific frequencies of the antennas 28 and 29, respectively.

[0119] In the case of Modification 11 as well, in the case of Modification 10 above, between the second element portions 28b, between the second element portions 29b, and between the second element portion 28b and the second element portion 29b. It is effective to form the coating film 11 so that contact does not occur and the length of each element portion does not vary. Example

[0120] A radio wave shield having the configuration shown in Fig. 15 (Modification 3) was produced and used as an example. Specifically, first, the surface of a dough (base material) made of Toyo Senka Co., Ltd. # 0717- CU (beige) was coated using urethane roll resin using a roll coater method.

[0121] Next, an antenna was prepared by screen printing on the surface of the fabric coated with urethane resin using silver paste in which 63% by weight of silver fine particles were dispersed and mixed in polyester resin. On the fabricated antenna, almost no silver paste bleeding was visible. The line width of the first element part and the second element part was 1.58 mm, the length of the first element part was 12.94 mm, and the length of the second element part was 9.32 mm.

[0122] The transmission attenuation of the obtained radio wave shield was measured using a network analyzer manufactured by Agilent.

[0123] As a comparative example, a radio wave shield was produced by the same process as in the above example except that a coating film of urethane resin was not formed, and the transmission attenuation was measured in the same manner. In the comparative example, bleeding of the silver paste was visually recognized on the manufactured antenna.

FIG. 26 is a characteristic diagram showing the transmission attenuation amounts of the example and the comparative example together. As can be seen from this graph, in the example, a strong peak was observed around 2.4 GHz. From this, it was found that the example has a relatively high frequency selectivity. On the other hand, in the comparative example, although the transmission attenuation increased slightly in the vicinity of 2.4 GHz, the peak-like peak was not observed. From this, it was found that the comparative example has almost no frequency selectivity.

[0125] From the above results, it is possible to suppress the bleeding of the silver paste by applying the grease coating on the surface of the fabric prior to the formation of the antenna, and to produce a radio frequency shield with high frequency selectivity. I found that I can do it.

Industrial applicability

[0126] As described above, the radio wave shielding body according to the present invention has high radio wave shielding properties against radio waves of a specific frequency, and includes wallpaper, partitions (partitions), cloth (roll screens), window glass, outer walls. It is useful as a panel, roof panel, ceiling panel, inner wall panel, floor panel, radio wave shield, etc.

Claims

The scope of the claims

[1] A substrate having at least one of a plurality of micropores and a plurality of irregularities on the surface, a coating film formed on the surface of the substrate,

A radio wave shielding body comprising: a plurality of radio wave reflection antennas formed using a radio wave reflection material as a material on the coating film!

[2] In the radio wave shield according to claim 1,!

The base material is a radio wave shield which is a cloth-like body.

[3] In the radio wave shield according to claim 1,!

The coating film is a radio wave shield substantially made of a resin.

[4] In the radio wave shield according to claim 1,!

The radio wave reflection material is a radio wave shield containing a conductive material.

[5] In the radio wave shield according to claim 1,!

Each of the radio wave reflecting antennas has three linear first element portions extending radially at substantially the same length at an angle of about 120 ° with respect to the antenna central force, and the first element. A radio wave shield having a line-shaped second element part coupled to the outer end of the part.

[6] A method of manufacturing a radio wave shielding body including a base material having at least one of a plurality of micropores and a plurality of irregularities on a surface and a plurality of radio wave reflection antennas formed on the base material. And

A method of manufacturing a radio wave shield, wherein the plurality of radio wave reflection antennas are formed using a radio wave reflection material after the surface of the substrate is coated with a coating film.