Radio wave control body

Abstract

To provide a radio wave control body in which the shape of each region is hardly visible in the radio wave control body including regions having different brightness.SOLUTION: The radio wave control body 11 includes one or more conductive elements 20. The conductive element 20 includes a base material layer 13 having optical transparency, a first conductive layer 16 provided on one surface of the base material layer 13 and including a conductor 12, and a second conductive layer 17 including the conductor 12, and the first conductive layer 16, the base material layer 13, and the second conductive layer 17 are laminated. The first conductive layer 16 is divided into at least two first and second regions 31 and 32 having different lightness in a plan view, and the lightness of the first region 31 is lower than that of the second region 32. The second conductive layer 17 is partitioned into third and fourth regions 33 and 34 having different brightness corresponding to the at least two first and second regions 31 and 32 of the first conductive layer 16 in a plan view. The third region 33 has a higher lightness than the fourth region 34.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a radio wave control device. [Background technology]

[0002] Mobile phones and wireless communications use radio waves in the frequency band of approximately 2 GHz to 300 GHz, known as centimeter waves or millimeter waves. Such short-wavelength radio waves have a tendency to travel in a straight line and are less likely to bend around obstacles. Therefore, to allow the radio waves to reach a wide area, radio wave control devices are installed on the surfaces of buildings, such as the walls, floors, ceilings, and pillars of buildings (hereinafter referred to as "walls, etc."). While most radio wave control devices are opaque, a transparent radio wave control device is required when installing them on window glass, for example. For example, Patent Document 1 proposes an electromagnetic shielding member with a visible light transmittance of 80% or more.

[0003] The electromagnetic shielding member of Patent Document 1 includes a light-transmitting film substrate and a conductive layer disposed on the substrate. The conductive layer has a mesh-like (lattice-like) conductive pattern made up of linear conductive lines that intersect each other at right angles and a plurality of square openings. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. WO2023 / 54634 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in electromagnetic shielding members such as those described in Patent Document 1, the conductive pattern formed on the conductive layer may differ depending on the region. For example, if the pitch between the mesh-like conductive lines of the conductive pattern differs between one region of the conductive layer and another region, the area occupied by the conductive lines per unit area will differ, resulting in differences in brightness depending on the region, making the boundaries between the regions of the conductive layer and the overall shape of the regions more visible.

[0006] The present invention has been made with an eye on the above-mentioned problems, and aims to provide a radio wave control body in which the shapes of each area are difficult to see when the conductive layer includes areas of different brightness. [Means for solving the problem]

[0007] To achieve the above object, the present invention includes the following subject matter.

[0008] Item 1: A radio wave control unit including one or more conductive elements, The conductive element is a light-transmitting substrate layer; a first conductive layer provided on one surface of the base layer and including a conductor; a second conductive layer including a conductor; the first conductive layer, the base material layer, and the second conductive layer are laminated together, the first conductive layer is divided into at least two regions, a first region and a second region, having different brightness levels when viewed from above, and the first region has a lower brightness level than the second region; A radio wave control body, wherein the second conductive layer is divided into at least two third and fourth regions of different brightness corresponding to the at least two first and second regions of the first conductive layer when viewed from above, and the third region is brighter than the fourth region.

[0009] Item 2: When viewed from above, the first conductive layer is divided into a first overlapping region where a first region of the first conductive layer and a third region of the second conductive layer overlap, and a second overlapping region where a second region of the first conductive layer and a fourth region of the second conductive layer overlap, The standard deviation of the brightness at multiple measurement positions is 2 or less, Item 2. The radio wave control device according to item 1, wherein the measurement positions include at least one position within the first overlapping region and at least one position within the second overlapping region.

[0010] Item 3: The radio wave control device according to item 1 or 2, wherein the second conductive layer is provided on at least one of one surface of the first conductive layer and the other surface of the base material layer.

[0011] Item 4: The first conductive layer includes the conductor in both or one of the first and second regions, Item 4. The radio wave controller according to any one of items 1 to 3, wherein the conductor is included in both or one of the third and fourth regions of the second conductive layer.

[0012] Item 5: The radio wave control device according to any one of items 1 to 4, wherein the conductor is a linear body and surrounds the area where no conductor is present.

[0013] Item 6: The radio wave control device according to any one of items 1 to 4, wherein the conductor is in the form of a thin film.

[0014] Item 7: The radio wave control device according to Item 4, wherein the second region of the first conductive layer does not include the conductor.

[0015] Item 8: The radio wave controller according to any one of items 1 to 7, which has a total light transmittance of 65% or more. [Effects of the Invention]

[0016] According to the present invention, when the conductive layer includes areas of different brightness, it is possible to provide a radio wave control device in which the shapes of the areas are difficult to see. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is a plan view of a radio wave control body according to an embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 4] 1 is a diagram for explaining the principle of a radio wave control body. FIG. [Figure 5] FIG. 10 is a plan view showing another embodiment of the radio wave control body. [Figure 6]FIG. 10 is a plan view showing another example of the conductive element. [Figure 7] FIG. 10 is a plan view showing another example of the conductive element. [Figure 8] 1. (A) to (F) are plan views showing other examples of the conductor, and are enlarged views of part B in FIG. [Figure 9] FIG. 10 is a bottom view of a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0018] (Overall configuration of radio wave control unit 11) An embodiment of the present invention will be described with reference to the drawings. The radio wave control body 11 of the present invention operates as a radio wave reflector that reflects radio waves, a radio wave absorber that absorbs radio waves, or a radio wave transmitting body that transmits radio waves. The radio wave control body 11 reflects, absorbs, or transmits radio waves with a frequency of 2 GHz or more and 300 GHz or less transmitted from a transmitter. The transmitter is a communication device or the like having a transmitting antenna capable of transmitting radio waves. The reflected or transmitted radio waves are propagated to a receiving unit. The receiving unit is a communication device having a receiving antenna capable of receiving radio waves. Examples of receiving units include smartphones, mobile phones, tablet devices, laptop computers, portable game consoles, repeaters, radios, and televisions. In the following description, the radio wave control body 11 will be described as a radio wave reflector.

[0019] The shape of the radio wave control unit 11 in a planar view is not limited, but is preferably, for example, a square, with the length L10 of one side being 20 cm or more and 400 cm or less. Radio waves with frequencies between 2 GHz and 300 GHz or less attenuate with distance, but in order to reflect with sufficient intensity at all points within a practical distance from the radio wave source (transmitter), the length of one side is preferably 20 cm or more. The upper limit of the length L10 of one side is not particularly limited, but is preferably 400 cm or less from a manufacturing perspective. The overall shape of the radio wave control unit 11 is not limited to a square and may be a rectangle or a polygon such as a triangle, pentagon, or hexagon. In this case, the length of the shortest side is set to 20 cm or more and 400 cm or less. Alternatively, the shortest distance between a vertex and the opposite side, or the shortest distance between a side and the opposite side, may be set to 20 cm or more and 400 cm or less. Furthermore, if the overall shape of the radio wave control unit 11 is circular, the diameter is set to 20 cm or more and 400 cm or less. If the overall shape of the radio wave control body 11 is elliptical, the minor axis is set to 20 cm or more and 400 cm or less. If the overall shape of the radio wave control body 11 is sector-shaped, the length of the shorter arc or radius is set to 20 cm or more and 400 cm or less. Furthermore, the overall shape of the radio wave control body 11 may be a three-dimensional shape such as a cylindrical or conical shape. The shape and size of the radio wave control body 11 are selected appropriately depending on the manner in which the radio wave control body 11 is used.

[0020] It is preferable that the thickness L1 of the radio wave control body 11 is set to 1 mm or less. The thickness L1 of the radio wave control body 11 is set to a thickness that allows the radio wave control body 11 to be flexible and that prevents force from concentrating on the conductor 12 when an external force is applied to the radio wave control body 11 to bend it.

[0021] The radio wave control body 11 has a total light transmittance of 65% or more, preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more, under a D65 standard light source (one of the standard light sources defined by the CIE (Commission Internationale de l'Eclairage)). The total light transmittance refers to the ratio of the total transmitted light flux to the parallel incident light flux on a test piece, and is defined in JIS K7375:2008. That is, the radio wave control body 11 is so-called "transparent." "Transparent" means that one side of the radio wave control body 11 can be seen from the other side, and includes translucency. The radio wave control body 11 may also be colored as a whole. The material of the base layer 13, which will be described later, and the configurations of the conductors 12 of the first conductive layer 16 and the second conductive layer 17 are selected so that the radio wave control body 11 has a total light transmittance of 65% or more.

[0022] (Configuration of radio wave control body 11) The radio wave control body 11 is composed of one conductive element 20, or is composed of a plurality of conductive elements 20 arranged in series. Figures 1 to 3 show an example in which the radio wave control body 11 is composed of one conductive element 20. Figure 5 shows an example in which the radio wave control body 11 is composed of a plurality of conductive elements 20. Each example will be explained below.

[0023] (Example in which the radio wave control device 11 is composed of one conductive element 20) An example will be described in which the radio wave control device 11 is composed of one conductive element 20. As shown in Figs. 1 to 3, the conductive element 20 comprises a light-transmitting base layer 13, a first conductive layer 16 including a conductor 12 and a second conductive layer 17 including the conductor 12, which are provided on one surface of the base layer 13, and in this embodiment, the first conductive layer 16, base layer 13, and second conductive layer 17 are laminated in this order. Radio waves enter from the first conductive layer 16 side and are reflected.

[0024] In the following description, unless otherwise specified, the radio wave control body 11 will be described assuming that the up-down direction in FIG. 3 is the up-down direction of the radio wave control body 11 (conductive element 20), but the up-down direction of the radio wave control body 11 does not have to be along the vertical direction.

[0025] Although not shown, a protective layer for protecting first conductive layer 16 and second conductive layer 17 may be provided on the surface of first conductive layer 16 opposite to base material layer 13 (the upper surface of first conductive layer 16) and on the surface of second conductive layer 17 opposite to base material layer 13 (the lower surface of second conductive layer 17). Furthermore, an adhesive layer made of an adhesive may be provided between the protective layer and first conductive layer 16 and second conductive layer 17 to bond the protective layer to first conductive layer 16 and second conductive layer 17.

[0026] (Base material layer 13) The base layer 13 is a sheet-like member on whose upper surface the first conductive layer 16 is formed. The term "sheet" refers to a shape in which the thickness of the object is 10% or less of the maximum length between the outer edges in a planar view. When the shape in a planar view is rectangular, the "maximum length between the outer edges in a planar view" refers to the length of the diagonal. When the shape in a planar view is circular, the "maximum length between the outer edges in a planar view" refers to the length of the diameter. In this specification, the term "sheet" also includes membranes, foils, films, etc.

[0027] The base layer 13 is made of, for example, PET (polyethylene terephthalate), FR4 (glass fiber cloth impregnated with epoxy resin and thermosetting processed to form a plate), glass, silicon, etc. Alternatively, a synthetic resin may be used as the material, and examples of the synthetic resin include one or more selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polyester, polyformaldehyde, polyamide, polyphenylene ether, vinylidene chloride, polyvinyl acetate, polyvinyl acetal, AS resin, ABS resin, acrylic resin, fluororesin, nylon resin, polyacetal resin, polycarbonate resin, polyamide resin, and polyurethane resin.

[0028] The base material layer 13 is formed to have an outer shape that is square in plan view, but is not limited to this, and may have a rectangular, circular, elliptical, sector-shaped, polygonal, three-dimensional shape, or the like, in accordance with the overall shape of the radio wave control body 11.

[0029] The base layer 13 is optically transparent and transparent, that is, the total light transmittance of the base layer 13 is preferably 80% or more, and more preferably 85% or more.

[0030] (First conductive layer 16) The first conductive layer 16 is formed on one surface (the upper surface in FIG. 3 ) of the base layer 13. The first conductive layer 16 is partitioned into at least two first and second regions 31, 32 with different brightness levels when viewed from above. In this embodiment, as shown in FIG. 1 , there are two first and two second regions 31, 32. The first region 31 has a lower brightness than the second region 32. The brightness of the first region 31 and the brightness of the second region 32 refer to the brightness of the portion corresponding to the first region 31 and the portion corresponding to the second region 32 in a laminate made of the base layer 13 and the first conductive layer 16 when viewed from above.

[0031] 1, the first region 31 is rectangular (square) in plan view and is located at the center of the radio wave control body 11, while the second region 32 has a rectangular ring-like overall shape and surrounds the periphery of the first region 31. Note that in FIGS. 1 and 2, the first region and third and fourth regions 33 and 34, which will be described later, are colored gray for ease of explanation.

[0032] The first region 31 includes a conductor 12. The conductor 12 may be a linear body or may be a thin film that corresponds to the shape of the first region 31. The configuration of the conductor 12 will be described in detail later.

[0033] The second region 32 does not contain the conductor 12 and is simply a space. The second region 32 may be filled with an adhesive for adhering a protective layer. Because the second region 32 is a space, it has a higher brightness than the first region 31 which contains the conductor 12. The second region 32 only needs to have a higher brightness than the first region 31, and the second region 32 may contain the conductor 12.

[0034] (Second conductive layer 17) As shown in FIG. 3, the second conductive layer 17 is formed on the other surface (the bottom surface in FIG. 3) of the base layer 13. The second conductive layer 17 is partitioned into at least two third and four regions 33, 34 having different brightness levels when viewed from above. In this embodiment, as shown in FIG. 2, the second conductive layer 17 has two third and two fourth regions 33, 34 when viewed from above (the bottom surface). The third region 33 has a higher brightness than the fourth region 34. The brightness of the third region 33 and the brightness of the fourth region 34 refer to the brightness of the portion of the laminate made of the base layer 13 and the second conductive layer 17 that corresponds to the third region 33 and the fourth region 34 when viewed from above.

[0035] The third region 33 has a size and shape corresponding to the first region 31 of the first conductive layer 16 and is formed at a corresponding position. The fourth region 34 has a size and shape corresponding to the second region 32 of the first conductive layer 16 and is formed at a corresponding position. The first region 31 and the third region 33, and the second region 32 and the fourth region 34 do not necessarily have to be completely identical in size, shape, and position; some degree of deviation or difference is acceptable as long as the shape of the first conductive layer 16 and the shape of the second conductive layer 17 are difficult to visually recognize. The positions of the edges of the first region 31 and the third region 33, and the edges of the second region 32 and the fourth region 34 do not have to be strictly coincident in a plan view; a positional deviation of 20% or less, preferably 10% or less, is acceptable with respect to the maximum length of a straight line connecting any two points on the edge of the first region 31.

[0036] The third region 33 and the fourth region 34 include a conductor 12. The conductor 12 may be linear, or may be a thin film corresponding to the shapes of the third region 33 and the fourth region 34. The configuration of the conductor 12 in the first region 31, the third region 33, and the fourth region 34 may be arbitrarily selected from linear or thin film, and may be different for the first region 31, the third region 33, and the fourth region 34. For example, the conductor 12 in the first region 31 may be linear, and the conductor 12 in the third region 33 and the fourth region 34 may be thin film.

[0037] The fourth region 34 may simply be a space without including the conductor 12. In this case, the fourth region 34 may be filled with an adhesive material for adhering the protective layer.

[0038] (Brightness of Radio Control Unit 11) When viewed from above, the radio wave control device 11 is divided into a first overlapping region 41 where the first region 31 of the first conductive layer 16 and the third region 33 of the second conductive layer 17 overlap, and a second overlapping region 42 where the second region 32 of the first conductive layer 16 and the fourth region 34 of the second conductive layer 17 overlap. The standard deviation of brightness at multiple measurement positions on the radio wave control device 11 (i.e., on the first conductive layer 16) when viewed from above is 2 or less. The measurement positions include at least one arbitrary position in the first overlapping region 41 and at least one arbitrary position in the second overlapping region 42. Brightness is measured at preferably five or more measurement positions, and more preferably ten or more measurement positions.

[0039] Conventional radio wave control devices do not include a second conductive layer 17 for adjusting brightness. Therefore, when the first conductive layer 16 is divided into first and second regions 31 and 32 with different brightnesses, the difference in brightness between the first region 31 and the second region 32 is large, and the boundary between the first region 31 and the second region 32 and the overall shape of the conductive element 20 may be visible.

[0040] However, in this embodiment, a second conductive layer 17 is provided to adjust the brightness of the first conductive layer 16. As shown in FIG. 4 , a third region 33 of the second conductive layer 17 having a high brightness is overlapped with a first region 31 of the first conductive layer 16 having a low brightness, and a fourth region 34 of the second conductive layer 17 having a low brightness is overlapped with a second region 32 of the first conductive layer 16 having a high brightness. Therefore, in the entire conductive element 20, the standard deviation of brightness between a first overlapping region 41 where the first and third regions 31 and 33 overlap and a second overlapping region 42 where the second and fourth regions 32 and 34 overlap is 2 or less, and the difference in brightness is small. Therefore, the boundary between the first overlapping region 41 and the second overlapping region 42 and the shape of the conductor 12 are difficult to visually recognize.

[0041] (Example in which the radio wave control device 11 is composed of multiple conductive elements 20) Fig. 5 shows an example in which the radio wave control body 11 is composed of a plurality of conductive elements 20. The radio wave control body 11 is formed by continuously arranging rectangular conductive elements 20 to have any shape as a whole, and in Fig. 5 it is formed in a rectangular shape (square). Unless otherwise specified, the configuration of each conductive element 20 is the same as the embodiment shown in Figs. 1 to 3, and therefore detailed description will be omitted. In the example of Fig. 5, the base material layer 13 of the plurality of conductive elements 20 may be formed integrally.

[0042] (Examples of shapes of the first to fourth regions of the conductive element 20) 1 is composed of one conductive element 20, and in either case where the radio wave control device 11 shown in FIG. 5 is composed of a plurality of conductive elements 20, the shape of the first region 31 in the plan view of the first conductive layer 16 of the conductive element 20 is not limited to a rectangular shape, and may be any shape such as a circle, an ellipse, a polygon, or a combination thereof. The second region 32 to the fourth region 34 have shapes corresponding to the shape of the first region 31. Furthermore, when the radio wave control device 11 is composed of a plurality of conductive elements 20, the shapes of the first regions 31 of the respective conductive elements 20 may be different.

[0043] Fig. 6 shows an example of the conductive element 20. Fig. 6 shows each conductive element 20 when the radio wave control device 11 shown in Fig. 5 is made up of a plurality of conductive elements 20.

[0044] When the multiple conductive elements 20 are the same, and the radio wave control body 11 functions as a radio wave reflector, it causes so-called "specular reflection" of the radio waves. "Specular reflection" means that the reflection angle α2 of the reflected wave is the same as the incident angle α1.

[0045] The configuration of the conductive element 20 shown in FIG. 6 may be applied to the conductive element 20 when the radio wave control device 11 is configured from one conductive element 20.

[0046] 6 and the shape of FIG. 7 described later, the vertical direction in FIGS. 6 and 7 is the vertical direction of the conductive element 20, and the horizontal direction in FIGS.

[0047] In the example shown in FIG. 6, each conductive element 20 is square-shaped, and the first region 31 of the first conductive layer 16 includes top, bottom, left, and right side edge portions 21a-21d extending along the four edges of the square, and a central portion 22 located at the center in the vertical direction in FIG. 6 and extending leftward from the right side edge portion 21a. The central portion 22 extends leftward in FIG. 6 to a length approximately half the side length L20, and includes a first central portion 22a whose vertical length is approximately 5 / 6 of the side length L20. The central portion 22 further includes a second central portion 22b whose vertical length is approximately 1 / 8 the side length L20 and whose horizontal length is approximately 1 / 10 the side length L20.

[0048] The second region 32 is a region surrounded by the upper, lower, left, and right side edge portions 21a to 21d, the first central portion 22a, and the second central portion 22b. The second region 32 does not include the conductor 12 and is a space, and the base layer 13 is exposed through the second region 32.

[0049] Although not shown, the third region 33 of the second conductive layer 17 has a size and shape corresponding to the first region 31 of the first conductive layer 16 and is formed at a corresponding position. The fourth region 34 has a size and shape corresponding to the second region 32 of the first conductive layer 16 and is formed at a corresponding position.

[0050] Even in the example of Fig. 6, in the entire conductive element 20, the standard deviation of brightness between the first overlapping region 41 where the first and third regions 31, 33 overlap and the second overlapping region 42 where the second and fourth regions 32, 34 overlap is 2 or less, and the difference in brightness is small. Furthermore, because the difference in brightness between the conductive elements 20 is small, the radio wave control device 11 as a whole is perceived as having a single brightness. The conductive element 20 shown in Fig. 6 may be used as the radio wave control device 11 shown in Fig. 1.

[0051] (Other Examples of Shapes of the First to Fourth Regions of the Conductive Element 20) When the radio wave control body 11 is composed of multiple conductive elements 20, the multiple conductive elements 20 may be of different types. Different types refer to different phase differences (hereinafter also referred to as "phase differences") between the radio waves incident on each conductive element 20 and the radio waves reflected from each conductive element 20. For example, the conductive elements 20A to 20C shown in FIG. 7 have different shapes for the first region 31 to the fourth region 34, resulting in different phase differences. The radio wave control body 11 has multiple conductive elements 20A to 20C of different types as one unit, and these units are arranged repeatedly. When such a radio wave control body 11 functions as a radio wave reflector, it causes so-called "polarized reflection" of radio waves. "Polarized reflection" refers to the presence of at least one reflection angle α2 at which the reflection intensity of the reflected wave is greater than the other reflection angles α2, and the reflection angle α2 of the reflected wave at this time is an angle different from the incident angle α1.

[0052] The conductor 12 in the first region 31 of the conductive element 20A includes upper, lower, left, and right side edge portions 21a-21d extending along the four edges of the square, and a central portion 22 located at the center in the vertical direction in FIG. 7, continuing from the right side edge portion 21a and extending leftward. The central portion 22 extends leftward to a length approximately 5 / 6 of the length L20 of one side of the conductive element 20A. The central portion 22 includes a first central portion 22a located on the right side edge portion 21a side and having a vertical length approximately 2 / 3 of the length L20 of one side of the conductive element 20A. The central portion 22 also includes a second central portion 22b that is continuous with the first central portion 22a and slightly shorter in the vertical direction than the first central portion 22a. The horizontal length of the first central portion 22a is approximately 1 / 2 of the length L20 of one side of the conductive element 20. The area surrounded by the upper, lower, left and right side edge portions 21a to 21d and the first central portion 22a and the second central portion 22b is the second area 32, which does not include the conductor 12 and is a space, and the base material layer 13 is exposed through the second area 32.

[0053] The conductive element 20B includes upper, lower, left, and right side edge portions 21a-21d extending along the four edges of the square, and a central portion 22 located at the center in the vertical direction in FIG. 7, continuing from the right side edge portion 21a and extending leftward. The central portion 22 extends leftward to a length approximately 5 / 6 of the length L20 of one side of the conductive element 20B. The central portion 22 includes a first central portion 22a located on the right side edge portion 21a side and having a vertical length approximately 2 / 3 of the length L20 of one side. The central portion 22 also includes a second central portion 22b continuing from the first central portion 22a and having a vertical length slightly longer than that of the first central portion 22a. The horizontal length of the first central portion 22a is approximately 1 / 6 of the length L20 of one side. The area surrounded by the upper, lower, left and right side edge portions 21a to 21d and the first central portion 22a and the second central portion 22b is the second area 32, which does not include the conductor 12 and is a space, and the base material layer 13 is exposed through the second area 32.

[0054] The conductive element 20C includes side edge portions 21a-21d extending along the four edges of the square, and a central portion 22. The right side edge portion 21a has a length in the left-right direction that is approximately 1 / 2 of the side length L20. The central portion 22 is located in the center in the up-down direction and extends continuously from the right side edge portion 21a toward the left for a length that is approximately 5 / 6 of the side length L20 of the conductive element 20C. The length in the up-down direction is approximately 2 / 3 of the side length L20. The area surrounded by the top, bottom, left, and right side edge portions 21 and the central portion 22 is a second region 32. The second region 32 does not include the conductor 12 and is a space, and the base material layer 13 is exposed through the second region 32.

[0055] Although not shown, the third region 33 of the second conductive layer 17 has a size and shape corresponding to the first region 31 of the first conductive layer 16 and is formed at a corresponding position. The fourth region 34 has a size and shape corresponding to the second region 32 of the first conductive layer 16 and is formed at a corresponding position.

[0056] 7, in each of the conductive elements 20A to 20C, the standard deviation of brightness between the first overlapping region 41 where the first and third regions 31, 33 overlap and the second overlapping region 42 where the second and fourth regions 32, 34 overlap is 2 or less, and the difference in brightness is small. Furthermore, because the difference in brightness between the conductive elements 20 is small, the radio wave control body 11 as a whole is visually recognized as having a single brightness.

[0057] The configuration of the conductive element 20 is not limited to the above example and can be appropriately selected depending on the frequency and intensity of the radio waves to be reflected, absorbed, or transmitted. The shape of the first region 31 may be, for example, any shape in plan view, such as rectangular, circular, elliptical, triangular, or polygonal. The shapes, sizes, and arrangements of the first region 31 and the second region 32 are arbitrary. For example, the first region 31 and the second region 32 may be periodically arranged in any shape, such as rectangular, circular, elliptical, triangular, or polygonal. Even in these cases, the second region 33 and the third region 34 are set depending on the shapes of the first region 31 and the second region 32, respectively.

[0058] (Example of the configuration of the conductor 12) An example of the configuration of the conductor 12 included in the first region 31 of the first conductive layer 16, and the third region 33 and fourth region 34 of the second conductive layer 17 of the conductive element 20 will be described. Whether the radio wave control body 11 shown in FIG. 1 is composed of one conductive element 20 or the radio wave control body 11 shown in FIG. 5 is composed of multiple conductive elements 20, the conductive element 20 may be provided with the conductor 12 described below. Note that if the second region 32 includes the conductor 12, the second region 32 may also have the conductor 12 described below. Furthermore, different types of conductive elements 20A to 20C may also have the conductor 12 described below.

[0059] In one example, the conductor 12 may be a thin film. The first region 31, the third region 32, and the fourth region 34 are made up of the thin film conductor 12, and the thin film conductor 12 has the shapes of the first region 31, the third region 32, and the fourth region 34 described above. In this case, the brightness of the first region 31, the third region 32, and the fourth region 34 is adjusted by the thicknesses L3 and L11 of the thin film.

[0060] The conductor 12 is preferably made of silver (Ag), for example. The conductor 12 may be made of any metal having free electrons, and is not limited to silver. For example, the conductor 12 may be made of one or more metals selected from the group consisting of gold, copper, platinum, aluminum, titanium, silicon, indium tin oxide, and alloys (e.g., alloys containing nickel, chromium, and molybdenum). Examples of alloys containing nickel, chromium, and molybdenum include various grades of Hastelloy B-2, B-3, C-4, C-2000, C-22, C-276, G-30, N, W, and X.

[0061] The conductor 12 may be formed on the base layer 13 by forming a film of the conductor 12, forming a pattern by etching, and then extracting a conductive thin film having the pattern. Alternatively, a base film having a lift-off layer may be coated with a photosensitive resist, forming a pattern by photolithography, filling the patterned portion with the conductor 12, and then extracting a conductive thin film having the pattern.

[0062] Alternatively, the conductor 12 may be attached to the base layer 13 with an adhesive layer containing a transparent adhesive.

[0063] The thickness (film thickness) L3 of the conductor 12 in the first region 31 of the first conductive layer 16 and the thickness (film thickness) L11 of the conductor 12 in the second region 32 of the second conductive layer 17 are, for example, 500 nm (0.5 μm). From the viewpoint of ensuring appropriate radio wave intensity, the thicknesses L3 and L11 are preferably 50 nm or more.

[0064] (Another example of the configuration of the conductor 12) FIG. 8 shows another example of the conductors 12 included in the first region 31, the third region 32, and the fourth region 34. The conductors 12 may be linear (thin linear conductive wires). In this case, the first region 31, the third region 32, and the fourth region 34 include one or more linear conductors (linear bodies) 12 and regions 12a without the conductors 12, surrounded by the conductors 12. As shown in FIG. 8(A), the conductors 12 and the regions 12a without the conductors 12 are periodically arranged at a predetermined interval. The distance between adjacent regions 12a without the conductors 12 is equal to the line width L6 of the conductors 12. Note that "linear" means that the longitudinal length is 3000 times or more the length in the direction perpendicular to the longitudinal direction. Also, FIGS. 8(A) to 8(F) only show the conductors 12 and the regions 12a without the conductors, and do not show the configuration of other layers. The area 12a without the conductor may be filled with an adhesive or the like for attaching a protective layer.

[0065] In the example of FIG. 8(A), the conductors 12 are arranged at equal intervals in the vertical and horizontal directions, and the conductor-free regions 12a surrounded by the conductors 12 are square. That is, the conductor-free regions 12a are arranged at intervals equal to the line width L6 of the conductors 12. The conductors 12 (linear bodies 12A) along the horizontal direction and the conductors 12 (linear bodies 12B) along the vertical direction are electrically connected at the intersections where they overlap. The line width L6 of the linear bodies 12A and 12B is set to be 0.1 μm or more and 4.0 μm or less. The length L7 between adjacent linear bodies 12A and 12B along the vertical or horizontal direction (the length of one side of the square conductor-free region 12a) is set to be longer than the wavelength of visible light and shorter than the wavelength of the radio wave reflected by the radio wave control device 11, and in this embodiment, it is set to be 2 μm or more and 10 cm or less. More preferably, the thickness is 20 μm or more and 1 cm or less, even more preferably, 25 μm or more and 1 mm or less, and even more preferably, 30 μm or more and 250 μm or less.

[0066] In addition, in the conductive element 20, the spacing between adjacent linear bodies 12A extending in the horizontal direction is different from the spacing between adjacent linear bodies 12B extending in the vertical direction, and the shape of the region 12a without conductors may be rectangular.

[0067] The arrangement of the conductors 12 and the conductor-free regions 12a surrounded by the conductors 12 may also be as shown in Figures 8(B) to 8(F). In Figure 8(B), the conductors 12 are arranged in a brickwork pattern. A plurality of first linear bodies 12A are arranged horizontally and vertically at predetermined intervals, and a plurality of second linear bodies 12B extending vertically are arranged in a staggered pattern between vertically adjacent first linear bodies 12A. The staggered pattern refers to a state in which a plurality of second linear bodies 12B extending vertically are arranged horizontally at predetermined intervals, a plurality of second linear bodies 12B forming one row are located between a plurality of second linear bodies 12B forming a row adjacent to this row in the vertical direction, and the second linear bodies 12B in every other row are arranged in a straight line. The region 12a without a conductor is a region surrounded by two adjacent first linear members 12A and two adjacent second linear members 12B.

[0068] In FIG. 8(C), the conductors 12 are arranged so that the conductor-free regions 12a are triangular. The conductor-free regions 12a include a plurality of triangular first conductor-free regions 12b and a plurality of inverted triangular second conductor-free regions 12c. The first conductor-free regions 12b and the second conductor-free regions 12c are arranged at regular intervals in the horizontal and vertical directions, and the second conductor-free regions 12c are arranged between adjacent first conductor-free regions 12b. Each of the first conductor-free regions 12b and the second conductor-free regions 12c is surrounded by the first to third linear bodies 12A to 12C. The first linear body 12A is arranged along the horizontal direction, the second linear body 12B is arranged along a direction oblique to the first linear body 12A, and the third linear body 12C is arranged along a direction symmetrical to the second linear body 12B with respect to the first linear body 12A. Note that although the shape of each of the regions 12b and 12c is an equilateral triangle in Fig. 8(C), it may also be an isosceles triangle or a triangle with three sides of different lengths.

[0069] 8(D), the conductors 12 are arranged surrounding regular hexagonal conductor-free regions 12a. The conductor-free regions 12a are arranged continuously in the vertical direction at intervals of the line width L6 of the conductors 12, and multiple such rows are arranged in the horizontal direction. Between adjacent conductor-free regions 12a in the vertical direction, conductor-free regions 12a in adjacent rows in the horizontal direction are arranged.

[0070] In FIG. 8(E), the region 12a free of conductors includes a plurality of types of regions 12b to 12d with different shapes. The region 12a free of conductors includes a first region 12b free of conductors that is a regular pentagon surrounded by linear conductors 12, a second region 12c free of conductors that is an inverted pentagon, and a third region 12d free of conductors that is a rhombic shape. The first region 12b free of conductors to the third region 12d free of conductors are arranged at regular intervals in the horizontal and vertical directions. Specifically, the first region 12b free of conductors and the second region 12c free of conductors are arranged adjacent to each other in the vertical direction with an interval of the line width L6 of the conductors 12 spaced apart, and pairs of the first region 12b free of conductors and the second region 12c free of conductors are periodically arranged side by side in the horizontal direction. A third region 12d without a conductor is disposed between a pair of a first region 12b without a conductor and a second region 12c without a conductor that are adjacent in the horizontal direction. The shapes formed by the first region 12b without a conductor, the second region 12c without a conductor, and the third region 12d without a conductor are arranged at the same period.

[0071] In FIG. 8(F), the conductor-free region 12a includes a plurality of conductor-free regions 12b-12d of different shapes. The conductor-free region 12a includes a circular first conductor-free region 12b surrounded by linear conductors 12, a substantially triangular second conductor-free region 12c, and a substantially inverted triangular third conductor-free region 12d. The first to third conductor-free regions 12b-12d are periodically arranged at regular intervals in the vertical and horizontal directions. The first conductor-free regions 12b are periodically arranged in the horizontal and diagonal directions so as to be continuous with an interval of the line width L6 of the conductors 12.

[0072] The conductors 12 contained in the first region 31, the third region 32, and the fourth region 34 may have the same configuration, or may be different from one another. For example, the conductors 12 contained in the first region 31, the third region 32, and the fourth region 34 may all have the configuration shown in FIG. 8(A). In this case, the width of the conductors 12, the length L7 of one side of the conductor-free region 12a, etc. may be different or the same in each region. Furthermore, the conductors 12 contained in the first region 31, the third region 32, and the fourth region 34 may each be a thin film or may have the configurations shown in FIGS. 8(A) to 8(F).

[0073] (Conductor coverage) The conductor coverage is the ratio of the area occupied by the conductor 12 to the area of ​​each of the first to fourth regions 31 to 34 in a plan view. The conductor coverage is measured using a scanning electron microscope (SEM), a transmission electron microscope (TEM), an optical microscope, or the like.

[0074] (Brightness adjustment) The brightness of the first overlap region 41 and the second overlap region 42 of the conductive element 20 of the radio wave control body 11 is adjusted by the thicknesses L3 and L11 and the conductor coverage rate of the conductor 12 contained in the first region 31 of the first conductive layer 16, the third region 33 and the fourth region 34 of the second conductive layer 17.

[0075] For example, when the conductor 12 is made up of one thin film conductor 12, the conductor coverage is 100%, and the brightness is adjusted by the thicknesses L3 and L11 of the conductor 12.

[0076] Furthermore, when the conductor 12 is a linear body as shown in FIG. 8, the brightness is adjusted by the thicknesses L3 and L11 of the conductor 12, as well as by the conductor coverage. The conductor coverage is determined by the line width L6 of the conductor 12 and the area of ​​the conductor-free region 12a surrounded by the conductor 12. In other words, when the thickness of the conductor 12 is constant, the brightness of these regions is adjusted by the area occupied by the conductor 12 per unit area in a planar view. Furthermore, when the phase difference of the conductive elements 20 is to be varied, the widths of the conductor 12 (linear body) in the first region 31, the third region 32, and the fourth region 34, the size of the conductor-free region 12a surrounded by the conductor 12, and the thickness of the conductor 12 may be appropriately selected for each conductive element 20. The conductor coverage is preferably 1% or more and 10% or less.

[0077] (Another example of the configuration of the conductive element 20) In the embodiment shown in FIGS. 1 and 5 , the first conductive layer 16 and the second conductive layer 17 of the conductive element 20 are each divided into two regions, but they may be divided into three or more regions. For example, if the first conductive layer 16 and the second conductive layer 17 are divided into three regions, the first, second, and fifth regions of the first conductive layer 16 and the third, fourth, and sixth regions of the second conductive layer 17 have corresponding sizes, shapes, and positions in a plan view. The conductive element 20 has first to third overlapping regions in a plan view. The first overlapping region is where the first region of the first conductive layer 16 overlaps with the third region of the second conductive layer 17. The second overlapping region is where the second region of the first conductive layer 16 overlaps with the fourth region of the second conductive layer 17. The third overlapping region is where the fifth region of the first conductive layer 16 and the sixth region of the second conductive layer 17 overlap. In this case, the standard deviation of brightness at at least three measurement positions, including at least one of each of the first to third overlapping regions, is 2 or less. The difference in brightness becomes small, making the boundary between the first overlapping region 41 and the second overlapping region 42 less visible.

[0078] (Another example of the configuration of the conductive element 20) 1 and 5, second conductive layer 17 is provided on the lower surface of base material layer 13, on the surface opposite to the surface on which first conductive layer 16 is provided. However, second conductive layer 17 may also be formed on the upper surface of first conductive layer 16. In this case, an adhesive layer containing an adhesive may be provided between first conductive layer 16 and second conductive layer 17. Furthermore, second region 32, which is a space, may be filled with adhesive to support second conductive layer 17.

[0079] Additionally, second conductive layer 17 may be formed on both the lower surface of base layer 13 and the upper surface of first conductive layer 16. Conductive element 20 is formed by laminating second conductive layer 17, first conductive layer 16, base layer 13, and second conductive layer 17 in this order.

[0080] Even in these cases, the standard deviation of brightness between the first overlapping region 41 and the second overlapping region 42 where the second and fourth regions 32, 34 overlap is 2 or less, so the difference in brightness is small and the boundary between the first overlapping region 41 and the second overlapping region 42 and the shape of the conductive element 20 are difficult to see.

[0081] (Evaluation test) Example 1 and Comparative Example 1 were produced as the radio wave control device 11, and a brightness evaluation test was carried out. However, the radio wave control device 11 of the present invention is not limited to Example 1.

[0082] Example 1 The radio wave control device 11 of Example 1 has a configuration similar to that of the embodiment shown in Figures 1 to 3, has a square planar shape, and is formed by laminating a second conductive layer 17, a base layer 13, and a first conductive layer 16 in this order. The first conductive layer 16 has a square first region 31 located in the center and a second region 32 located around the first region 31. The second conductive layer 17 has a square third region 33 provided at a position corresponding to the first region 31 in the center, and a fourth region 34 corresponding to the second region 32 and located around the third region 33.

[0083] The first region 31 and second region 32 of the first conductive layer 16 of the radio wave control device 11, and the third region 33 and fourth region 34 of the second conductive layer 17 will be described below.

[0084] (1) Radio Control Unit 11 Length of one side L10:20cm Thickness L1: 202 μm

[0085] (2) First region 31 of first conductive layer 16 Length of one side of the first region 31 L31: 5 cm Conductors 12: Linear bodies, arranged in a lattice pattern with square regions 12a where no conductors are present, as shown in FIG. 8(A). Line width L6 of conductor 12: 5 μm Length (pitch) L7 between adjacent conductors 12: 200 μm Thickness L3 of the conductor 12: 1 μm Material of conductor 12: copper

[0086] (3) Second region 32 of first conductive layer 16 No conductor 12. Just space.

[0087] (4) Base material layer 13 Thickness L2: 200 μm Material: PET Total light transmittance: 93%

[0088] (5) Third region 33 of second conductive layer 17 Length of one side of the third region 33 L33: 5 cm Conductors 12: Linear bodies, arranged in a lattice pattern with square regions 12a where no conductors are present, as shown in FIG. 8(A). Line width L6 of conductor 12: 5 μm Length (pitch) L7 between adjacent conductors 12: 200 μm Thickness L11 of the conductor 12: 1 μm Material of conductor 12: copper

[0089] (6) Fourth region 34 of second conductive layer 17 Conductors 12: Linear bodies, arranged in a lattice pattern with square regions 12a where no conductors are present, as shown in FIG. 8(A). Line width L6 of conductor 12: 5 μm Length (pitch) L7 between adjacent conductors 12: 100 μm Thickness L11 of the conductor 12: 1 μm Material of conductor 12: copper

[0090] (Comparative Example 1) Comparative Example 1 differs from Example 1 in the configuration of the second conductive layer 17. As shown in FIG. 9, the second conductive layer 17 of Comparative Example 1 has conductors 12 provided as the second conductive layer 17 on the entire lower surface of the base layer 13, and is not divided into third region 33 and fourth region 34. In other words, the arrangement of the conductors 12 is the same in the third region 33 and the fourth region 34. The configuration of Comparative Example 1 is as follows. The configurations of the first conductive layer 16 and base layer 13 are the same as those of Example 1, so a description thereof will be omitted.

[0091] (7) Second conductive layer 17 of Comparative Example 1 Conductor 12: A linear body, and as shown in FIG. 8(A), a lattice-like structure in which the region 12a without the conductor is square. Line width L6 of conductor 12: 5 μm Length (pitch) L7 between adjacent conductors 12: 200 μm Thickness L11 of the conductor 12: 1 μm Material of conductor 12: copper

[0092] In Comparative Example 1, in the radio wave control body 11, the area corresponding to the first area 31 of the first conductive layer 16 is designated as the first overlap area 41, and the area corresponding to the second area 32 of the first conductive layer 16 is designated as the second overlap area 42.

[0093] (Evaluation method) (brightness) In Example 1 and Comparative Example 1, five arbitrary points on the first conductive layer 16 of the radio wave control device 11 were determined as measurement positions, and the brightness was measured at each of these measurement positions. The measurement positions were three arbitrary points on the first overlapping region 41 of the radio wave control device 11 and two arbitrary points on the second overlapping region 42. The brightness was measured using a method in accordance with JIS Z 8722:2009.

[0094] The standard deviation of the brightness measured at these measurement positions was calculated, and a standard deviation of 2 or less was evaluated as "good", and a standard deviation of more than 2 was evaluated as "poor".

[0095] (Total light transmittance) The total light transmittance of the radio wave control devices 11 of Example 1 and Comparative Example 1 was measured. The total light transmittance was measured in accordance with the method specified in JISK 7375:2008 using a D65 standard light source. A total light transmittance of 65% or more was evaluated as "Good", and a total light transmittance of less than 65% was evaluated as "Poor".

[0096] (Evaluation results) The evaluation results are shown in Table 1. The total light transmittance was evaluated as "○" for both Example 1 and Comparative Example 1, but the brightness was evaluated as "○" in Example 1, and the difference in brightness between the first overlapping region 41 and the second overlapping region 42 of the radio wave control body 11 was small. As a result, the boundary between the first overlapping region 41 and the second overlapping region 42 and their shapes were difficult to see. On the other hand, the brightness was evaluated as "×" in Comparative Example 1, and the difference in brightness between the first overlapping region 41 and the second overlapping region 42 of the radio wave control body 11 was large, and the boundary between the first overlapping region 41 and the second overlapping region 42 and their shapes were easily visible.

[0097] [Table 1]

[0098] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. The dimensions, materials, shapes, and relative arrangements of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention. Expressions expressing the same state of things, such as "in a certain direction," "along a certain direction," "the same," "identical," "equal," and "homogeneous," not only refer to strict equality, but also to tolerances or differences to the extent that the same function is achieved. Expressions expressing triangular, rectangular, and circular shapes not only refer to shapes in the strict geometric sense, but also to shapes including irregularities, chamfers, etc., to the extent that the same effect is achieved. Expressions referring to one component as "comprising," "comprises," "equips," "includes," or "has" do not exclude the presence of other components. "Parallel" and "orthogonal" mean substantially "parallel" and "orthogonal," and include not only strict "parallel" and "orthogonal" states, but also include an error of several degrees. In addition, expressions such as "part" are sometimes used, such as "end part." For example, "end part" means a part with a certain range that includes the "end." The same applies to other expressions that include "part." [Explanation of symbols]

[0099] 11 Radio Control Body 12 Conductors 13 Base material layer 20 Conductive element 16 First conductive layer 17 Second conductive layer 31-34 Areas 1-4 41 First overlapping area 42 Second overlap area

Claims

1. A radio wave control body including one or more conductive elements, The conductive element is a light-transmitting substrate layer; a first conductive layer provided on one surface of the base layer and including a conductor; a second conductive layer including a conductor; the first conductive layer, the base material layer, and the second conductive layer are laminated together, the first conductive layer is partitioned into at least two first and second regions having different brightness levels when viewed from above, the first region having a lower brightness level than the second region; A radio wave control body, wherein the second conductive layer is divided into at least two third and fourth regions of different brightness corresponding to at least two of the first and second regions of the first conductive layer when viewed from a plane, and the third region is brighter than the fourth region.

2. When viewed from above, the conductive layer is divided into a first overlapping region where the first region of the first conductive layer and the third region of the second conductive layer overlap, and a second overlapping region where the second region of the first conductive layer and the fourth region of the second conductive layer overlap, The standard deviation of the brightness at the plurality of measurement positions is 2 or less, The radio wave control body according to claim 1 , wherein the measurement positions include at least one position within the first overlapping region and at least one position within the second overlapping region.

3. The radio wave control body according to claim 1 , wherein the second conductive layer is provided on at least one of one surface of the first conductive layer and the other surface of the base material layer.

4. the first conductive layer includes the conductor in both or one of the first region and the second region; The radio wave control device according to claim 1 , wherein the conductor is included in both or one of the third region and the fourth region of the second conductive layer.

5. The radio wave control device according to claim 1 , wherein the conductor is a linear body and surrounds the region where no conductor is present.

6. The radio wave control device according to claim 1 , wherein the conductor is in the form of a thin film.

7. The radio wave control device according to claim 4 , wherein the second region of the first conductive layer does not include the conductor.

8. 2. The radio wave control device according to claim 1, wherein the total light transmittance is 65% or more.

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