Radio wave reflecting device

Abstract

A radio wave reflecting device includes an array substrate, a plurality of radio wave reflecting elements, a wiring, and a metasurface. The array substrate has a radio wave reflecting region and a frame region surrounding the radio wave reflecting region. The plurality of radio wave reflecting elements are located on the radio wave reflecting region. The wiring is electrically connected to at least one of the plurality of radio wave reflecting elements, and at least a portion of the wiring overlaps the bezel region. The metasurface overlaps the wiring in the bezel region. The metasurface includes: a first conductive film; a plurality of absorption control units overlapping the first conductive film and each having at least one conductive film; and an insulating layer between the first conductive film and the plurality of absorption control units.

Description

Technical Field

[0001] One embodiment of the present invention relates to a radio wave reflecting device. Background Art

[0002] Liquid crystal molecules have dielectric anisotropy. Therefore, by adjusting the electric field applied to a liquid crystal layer containing the liquid crystal molecules, the orientation of the liquid crystal molecules can be controlled, thereby controlling the dielectric constant of the liquid crystal layer. It is known that by utilizing this property, a radio wave reflection device with controllable reflection characteristics can be provided (for example, see Patent Documents 1 and 2).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 11-103201

[0006] Patent Document 2: Japanese Patent Application Publication No. 2019-530387 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] One of the problems of one embodiment of the present invention is to provide a new radio wave reflection device including a liquid crystal layer. Alternatively, one of the problems of one embodiment of the present invention is to provide a radio wave reflection device including a liquid crystal layer and having excellent radio wave reflection characteristics.

[0009] Means for solving problems

[0010] One embodiment of the present invention is a radio wave reflection device. The radio wave reflection device includes an array substrate, multiple radio wave reflection elements, wiring, and a metasurface. The array substrate includes a radio wave reflection region and a frame region surrounding the radio wave reflection region. The multiple radio wave reflection elements are located on the radio wave reflection region. The wiring is electrically connected to at least one of the multiple radio wave reflection elements, and at least a portion of the wiring overlaps with the frame region. The metasurface overlaps with the wiring in the frame region. The metasurface includes: a first conductive film; multiple absorption control units overlapping with the first conductive film and each having at least one conductive film; and an insulating layer between the first conductive film and the multiple absorption control units. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] [ Figure 1 ] is a schematic expanded stereoscopic view of a radio wave reflecting device according to one embodiment of the present invention.

[0012] [ Figure 2 ] is a schematic end view of a radio wave reflecting device according to one embodiment of the present invention.

[0013] [ Figure 3A] is a schematic bottom view of a radio wave reflecting device according to one embodiment of the present invention.

[0014] [ Figure 3B ] is a schematic top view of a radio wave reflecting device according to one embodiment of the present invention.

[0015] [ Figure 4A ] is a schematic top view of a radio wave reflecting device according to one embodiment of the present invention.

[0016] [ Figure 4B ] is a schematic top view of a radio wave reflecting device according to one embodiment of the present invention.

[0017] [ Figure 4C ] is a schematic top view of a radio wave reflecting device according to one embodiment of the present invention.

[0018] [ Figure 5 ] is a schematic top view of a radio wave reflecting device according to one embodiment of the present invention.

[0019] [ Figure 6 ] is a schematic end view of a radio wave reflecting device according to one embodiment of the present invention.

[0020] [ Figure 7 ] is a schematic end view of a radio wave reflecting device according to one embodiment of the present invention.

[0021] [ Figure 8 ] is a schematic end view of a radio wave reflecting device according to one embodiment of the present invention.

[0022] [ Figure 9 ] is a schematic end view of a radio wave reflecting device according to one embodiment of the present invention.

[0023] [ Figure 10 ] is a schematic end view of a radio wave reflecting device according to one embodiment of the present invention.

[0024] [ Figure 11 ] is a schematic end view of a radio wave reflecting device according to one embodiment of the present invention.

[0025] [ Figure 12 ] is a schematic end view of a radio wave reflecting device according to one embodiment of the present invention.

[0026] [ Figure 13A ] is a schematic top view of the model metasurface of Example 1.

[0027] [ Figure 13B] is a schematic top view of the model metasurface of Example 2.

[0028] [ Figure 14 ] is a graph showing the frequency dependence of the radio wave absorption intensity of the model metasurface of Example 1.

[0029] [ Figure 15A ] is a graph showing the effect of the length difference of the rectangular conductive film in Example 2 on the radio wave absorption intensity of the model metasurface.

[0030] [ Figure 15B ] is a graph showing the effect of the length difference of the rectangular conductive film in Example 2 on the frequency of the radio waves absorbed by the model metasurface.

[0031] [ Figure 16A ] is a schematic top view of the model metasurface of Example 3.

[0032] [ Figure 16B ] is a schematic top view of the model metasurface of Example 4.

[0033] [ Figure 17A ] is a graph showing the frequency dependence of the radio wave absorption intensity of the model metasurface of Example 3.

[0034] [ Figure 17B ] is a graph showing the frequency dependence of the radio wave absorption intensity of the model metasurface of Example 4.

[0035] [ Figure 18A ] is a schematic top view of the model metasurface of Example 5.

[0036] [ Figure 18B ] is a schematic top view of the model metasurface of Example 5.

[0037] [ Figure 19 ] is a graph showing the frequency dependence of the radio wave absorption intensity of the model metasurface of Example 5.

[0038] [ Figure 20 ] is a schematic top view of the model metasurface of Example 6.

[0039] [ Figure 21 ] is a graph showing the frequency dependence of the radio wave absorption intensity of the model metasurface of Example 6.

[0040] [ Figure 22A ] is a graph showing the frequency dependence of the radio wave absorption intensity of the model metasurface of Example 7.

[0041] [ Figure 22B] is a graph showing the effect of the difference in length of the rectangular conductive film in Example 7 on the frequency of the radio waves absorbed by the model metasurface.

[0042] [ Figure 23 ] is a schematic top view of the model metasurface of Example 8.

[0043] [ Figure 24 ] is a graph showing the frequency dependence of the radio wave absorption intensity of the model metasurface of Example 8. DETAILED DESCRIPTION

[0044] Hereinafter, various embodiments of the present invention will be described with reference to the drawings, etc. However, the present invention can be implemented in various forms within the scope of the present invention and should not be construed as being limited to the description of the embodiments illustrated below.

[0045] In the drawings, the width, thickness, shape, etc. of various parts may be schematically shown in contrast to their actual forms to clarify the description. However, this is merely an example and does not limit the interpretation of the present invention. In this specification and the drawings, elements having the same functions as those described in the accompanying drawings are denoted by the same reference numerals, and duplicate descriptions may be omitted.

[0046] In this specification and claims, when expressing the form of arranging another structure above a certain structure, when it is simply expressed as "on...", unless otherwise specified, it includes both the case where the other structure is arranged directly above the certain structure in a manner connected to the certain structure, and the case where the other structure is arranged above the certain structure with another structure further between them.

[0047] In this specification and claims, the expression "a structure emerges from another structure" means that a portion of a structure is not covered by another structure, and also includes a form in which the portion not covered by another structure is further covered by another structure. Furthermore, this expression also includes a form in which a structure is not in contact with another structure.

[0048] In the embodiment of the present invention, when multiple films are formed simultaneously in the same process, these films have the same layer structure, the same material, and the same composition. Therefore, it is defined that the multiple films exist in the same layer.

[0049] 1. Composition of the radio wave reflection device

[0050] The following describes the structure of a radio wave reflection device, one embodiment of the present invention. The radio wave reflection device is a so-called liquid crystal radio wave reflection device, a device that utilizes the change in dielectric constant caused by the orientation change of the liquid crystal layer due to an electric field to reflect incident radio waves in a desired direction. The frequency of the wavelength that can be reflected is not restricted, but is, for example, in the range of 400 MHz to 50 GHz. Typically, the radio wave reflection device 100 can be used to reflect radio waves in the 400 MHz to 6.0 GHz band, the 2.5 GHz to 4.7 GHz band, and the 24 GHz to 50 GHz band.

[0051] Figure 1 A schematic expanded perspective view of a radio wave reflection device 100 is shown. The radio wave reflection device 100 includes a substrate (hereinafter referred to as an array substrate) 102 and an opposing substrate 104. A plurality of radio wave reflection elements arranged in a matrix having a plurality of columns and rows are provided between the array substrate 102 and the opposing substrate 104. The area in which the radio wave reflection elements are arranged (a single quadrilateral area that simultaneously surrounds all of the radio wave reflection elements) is referred to as a radio wave reflection area. In the radio wave reflection area, the radio wave reflection elements can be used to reflect incident radio waves in any direction. The area surrounding the radio wave reflection area is referred to as a frame area or a peripheral area.

[0052] The drive circuit (scanning line drive circuit 106, signal line drive circuit 108) for driving the radio wave reflection element can be set in the frame area of the array substrate 102. Figure 1 Multiple wirings not shown in the figure. The wiring electrically connects the driving circuit to the radio wave reflection element, and at least a portion extends in the frame area to reach the end of the array substrate 102. The wiring is exposed at the end of the array substrate 102 to form a plurality of terminals 110. A flexible printed circuit (FPC) substrate (not shown) is connected to the terminal 110. Various driving signals for driving the radio wave reflection device 100 are supplied from an external circuit via the flexible printed circuit and the terminal 110. The driving circuit generates a control signal for controlling the radio wave reflection element based on the signal and supplies it to the radio wave reflection element. It should be noted that it is also possible to not provide the scan line driving circuit 106 and / or the signal line driving circuit 108, but to supply the control signal directly to the radio wave reflection element from an external circuit via the wiring.

[0053] The radio wave reflecting device 100 further includes a metasurface 160 on the counter substrate 104. The metasurface 160 is provided to absorb a portion of the radio waves incident on the radio wave reflecting device 100 and suppress reflection in the frame region, as will be described in detail later. These components are described in detail below.

[0054] (1) Array substrate and counter substrate

[0055] Figure 2 A schematic end view of the radio wave reflecting device 100 is shown. This figure shows a portion of multiple radio wave reflecting elements 140 disposed in the radio wave reflecting area RA and a schematic end view of the frame area FA. The array substrate 102 and the counter substrate 104 face each other, providing physical strength to the radio wave reflecting device 100 and providing surfaces for disposing the radio wave reflecting elements. The array substrate 102 and the counter substrate 104 can be made of inorganic insulators such as glass or quartz, semiconductors such as silicon, polymers such as polyimide, polycarbonate, or polyester, or metals such as aluminum, copper, or stainless steel. When made of conductive materials such as metal, a primer layer 112 and an overcoat layer 132 are preferably provided on the surfaces on which the radio wave reflecting elements 140 are disposed, i.e., the surface of the array substrate 102 facing the counter substrate 104, and the surface of the counter substrate 104 facing the array substrate 102. The array substrate 102 and the counter substrate 104 may or may not transmit visible light. The array substrate 102 and / or the counter substrate 104 may also be flexible. The array substrate 102 and the counter substrate 104 are fixed to each other by a sealant 152 directly or via a first alignment film 144 and a second alignment film 148 described later.

[0056] (2) Radio wave reflection element

[0057] like Figure 2 As shown, the radio wave reflecting element 140 includes a drive electrode 142, a first alignment film 144 on the drive electrode 142, a liquid crystal layer 146 on the first alignment film 144, a second alignment film 148 on the liquid crystal layer 146, and a common electrode 150 on the second alignment film 148. Radio waves are incident from the common electrode 150 side. Therefore, in the radio wave reflecting element 140, the common electrode 150 functions as a patch electrode.

[0058] Each radio wave reflecting element 140 is connected to an element circuit including at least one transistor 120. Each element circuit may also include multiple transistors and may also include one or more capacitor elements. Figure 2 As will be understood, the element circuit including the transistor 120 and the radio wave reflecting element 140 are provided on the array substrate 102 directly or via the optional base coat layer 112. The structure of the transistor included in the element circuit is not restricted and may be a bottom-gate transistor or a top-gate transistor. Alternatively, the transistor may have gate electrodes above and below the semiconductor film. Figure 2The illustrated transistor is a bottom-gate transistor, comprising a gate electrode 122, a gate insulating film 124 on the gate electrode 122, a semiconductor film 126 on the gate insulating film 124, and a pair of terminals 128 and 130 on the semiconductor film 126. A planarization film 116 is provided on the transistor 120, and a radio wave reflecting element 140 is formed thereon. As an optional configuration, interlayer insulating films 114 and 118 may be provided between the transistor 120 and the planarization film 116, and on the planarization film 116, respectively.

[0059] The driving electrode 142 of the radio wave reflecting element 140 is electrically connected to the transistor 120 via an opening provided in the interlayer insulating film 118, the planarizing film 116, etc. Various signals supplied from the external circuit are supplied to the radio wave reflecting element 140 directly or via the driving circuit via the wiring 134 constituting the terminal 110. Figure 2 As shown, at least a portion of the wiring 134 extends over the frame area FA. The wiring 134 may be present in the same layer as the gate electrode 122 or in the same layer as the terminals 128 and 130. Alternatively, a portion of the wiring 134 may be present in the same layer as the gate electrode 122, while another portion may be present in the same layer as the terminals 128 and 130.

[0060] The gate electrode 122, gate insulating film 124, semiconductor film 126, terminals 128 and 130 that constitute the transistor 120, as well as the interlayer insulating films 114 and 118 that cover the transistor 120, the planarization film 116, and the wiring 134 can be formed using known materials and appropriately applying known methods, so a detailed description is omitted. In short, the gate electrode 122, terminals 128 and 130, and wiring 134 are formed by forming a film containing a metal such as tantalum, molybdenum, titanium, or aluminum using sputtering, chemical vapor deposition (CVD), or the like, and patterning it appropriately using a photolithography process. The semiconductor film 126 is formed as a film containing a Group 14 element, such as silicon, or a film containing an oxide of a Group 13 element such as indium or gallium. The semiconductor film 126 can also be formed using sputtering or CVD. The gate insulating film 124, interlayer insulating films 114 and 118, undercoat layer 112, and overcoat layer 132 are formed using sputtering or CVD methods, using inorganic compounds such as silicon oxide and silicon nitride. The planarizing film 116 is formed using a polymer such as acrylic resin, epoxy resin, polyimide, polyamide, or silicone resin, and can be formed using a wet film forming method such as spin coating, inkjet, or printing. The provision of the planarizing film 116 allows the radio wave reflecting element 140 to be formed on a flat surface.

[0061] The drive electrode 142 of the radio wave reflecting element 140 may include, for example, a metal such as copper, aluminum, tungsten, molybdenum, or titanium, or an alloy comprising at least one of these metals. Alternatively, the drive electrode 142 may include a light-transmitting conductive oxide such as indium-zinc oxide (IZO) or indium-tin oxide (ITO). The drive electrode 142 may have a single-layer structure or a stacked structure comprising layers of different compositions. For example, a stacked structure may be employed comprising a layer comprising a conductive oxide and a layer comprising the above-mentioned metal or alloy. Alternatively, in order to impart light translucency to the drive electrode 142 comprising a metal or alloy, the drive electrode 142 may have a mesh shape.

[0062] The first alignment film 144 provided on the plurality of drive electrodes 142 is provided to control the alignment of the liquid crystal molecules constituting the liquid crystal layer 146 provided thereon. The first alignment film 144 can be provided continuously across the plurality of radio wave reflecting elements 140. In other words, the first alignment film 144 can be provided so as to be shared by all radio wave reflecting elements 140 without being separated from adjacent radio wave reflecting elements 140.

[0063] The first alignment film 144 comprises a polymer such as polyimide or polyester. The first alignment film 144 is formed using a wet film-forming method such as inkjet, spin coating, printing, or dip coating, and its surface is rubbed. Alternatively, the first alignment film 144 may be formed using a photo-alignment process.

[0064] The liquid crystal layer 146 is sealed between the array substrate 102 and the counter substrate 104 by a sealant 152. The structure of the liquid crystal molecules contained in the liquid crystal layer 146 is not limited. Therefore, the liquid crystal molecules can be nematic liquid crystals, or can also be smectic liquid crystals, cholesteric liquid crystals, and chiral smectic liquid crystals. The thickness of the liquid crystal layer 146 is, for example, not less than 20 μm and not more than 50 μm, or not less than 30 μm and not more than 50 μm. Although not shown in the figure, in order to maintain this thickness throughout the entire radio wave reflection device 100, a spacer can also be provided in the liquid crystal layer 146. It should be noted that when the above-mentioned thickness of the liquid crystal layer 146 is used in the liquid crystal display device, the high responsiveness required for displaying dynamic images cannot be obtained, and it is obviously difficult to present the function as a liquid crystal display device.

[0065] The second alignment film 148 is also provided to control the alignment of the liquid crystal molecules and has the same structure as the first alignment film 144. The second alignment film 148 can also be formed continuously across adjacent radio wave reflecting elements 140 and shared by multiple radio wave reflecting elements 140. The first and second alignment films 144, 148 are arranged so that the direction in which the first alignment film 144 aligns the liquid crystal molecules is parallel to the direction in which the second alignment film 148 aligns the liquid crystal molecules. The first and second alignment films 144, 148 align the liquid crystal molecules in a fixed direction.

[0066] The common electrode 150 is provided for each radio wave reflecting element 140. Thus, the common electrode 150 is also configured in a matrix shape having multiple rows and multiple columns. In each radio wave reflecting element 140, the common electrode 150 overlaps with the driving electrode 142. As described above, radio waves are incident from the common electrode 150 side. Therefore, it is preferred that the common electrode 150 has a highly symmetrical shape such as a regular polygon or a circle so as to be able to efficiently reflect the two orthogonal components of the radio wave (vertically polarized wave and horizontally polarized wave). In addition, the size of the common electrode 150 can be appropriately adjusted according to the wavelength of the radio wave to be reflected. For example, the length in the row direction and the length in the column direction can be appropriately selected from a range of 1 mm to 40 mm. Although not shown, the multiple common electrodes 150 are electrically connected to each other in the column direction and / or the column direction by connecting wiring. A fixed potential (common potential) is supplied to the common electrode 150 directly from an external circuit or via the signal line driving circuit 108.

[0067] Similar to the drive electrode 142, the common electrode 150 may also include metals such as copper, aluminum, tungsten, molybdenum, titanium, alloys comprising at least one of these metals, or conductive oxides such as ITO and IZO. The common electrode 150 may also have a single-layer structure or a stacked structure formed by stacking layers of different compositions. The common electrode 150 may also be formed by sputtering, CVD, etc. It should be noted that the radio wave reflecting element 140 may or may not transmit visible light. For example, a metal or alloy having a thickness that does not transmit visible light may be used in the drive electrode 142 and the common electrode 150 to block visible light.

[0068] In the radio wave reflecting device 100, as described above, the first and second alignment films 144 and 148 align the liquid crystal molecules in parallel directions. Therefore, when no potential difference is applied between the drive electrode 142 and the common electrode 150, no longitudinal electric field is generated within the liquid crystal layer 146, resulting in a spray orientation of the liquid crystal molecules. The orientation of the liquid crystal layer 146 is the same across the radio wave reflecting elements 140, so the dielectric constant is also constant within the liquid crystal layer 146. The spread (phase) of the reflected wave generated by the incident radio wave from the common electrode 150 side reflecting off the surface of the common electrode 150 remains unchanged. As a result, the incident radio wave is reflected orthogonally by the radio wave reflecting device 100, providing a reflected wave at the same angle of incidence as the incident angle.

[0069] In contrast, when a device circuit controls the voltage applied to the drive electrode 142, creating a potential difference between the drive electrode 142 and the common electrode 150, the liquid crystal molecules stand upright due to the generated longitudinal electric field, undergoing bend orientation. At this point, if longitudinal electric fields of varying strength are generated between the radio wave reflecting elements 140, the dielectric constant of the liquid crystal layer 146 varies between the radio wave reflecting elements 140 depending on the strength of the longitudinal electric field. As a result, the phase of the reflected wave changes, and with it, the reflection direction of the radio wave incident on the radio wave reflecting area RA can be altered. The reflection direction can be arbitrarily controlled by varying the strength of the longitudinal electric field formed in the radio wave reflecting element 140.

[0070] (3) Metasurface

[0071] like Figure 1 and Figure 2 As shown, the metasurface 160 includes, as a basic structure, a first conductive film 162, a plurality of absorption control units 166, and an insulating layer 164 located between the first conductive film 162 and the plurality of absorption control units 166. The metasurface 160 can be fixed to the counter substrate 104 using an adhesive layer 136, or can be formed by sequentially stacking the first conductive film 162, the insulating layer 164, and the absorption control units 166 on the counter substrate 104.

[0072] Figure 3A and Figure 3B Schematic bottom and top views of the metasurface 160 are shown, respectively. Figure 3A is a schematic diagram of observing the metasurface 160 from the side of the first conductive film 162, Figure 3B is a schematic diagram of observing the metasurface 160 from the side of the absorption control unit 166. Figure 1 、 Figure 2 、 Figure 3AAs can be understood, the first conductive film 162 is provided so as to overlap with the frame area FA of the array substrate 102 and overlap with at least a portion of the wiring 134 in the frame area FA. Figure 1 and Figure 3A In the example shown, the first conductive film 162 is not provided in the frame area FA on the terminal 110 side, and the first conductive film 162 has a U-shape. However, the first conductive film 162 may also be provided in the frame area FA on the terminal 110 side to form the first conductive film 162 in a manner that surrounds the four sides of the radio wave reflection area RA.

[0073] The first conductive film 162 may include, for example, a conductive oxide such as ITO or IZO, or may include a metal such as copper, aluminum, tungsten, molybdenum, titanium, or an alloy comprising at least one of these metals. Preferably, the first conductive film 162 is formed by including a metal having high conductivity such as titanium, molybdenum, tungsten, etc., so that the metasurface 160 exhibits high radio wave absorption characteristics. The first conductive film 162 may be electrically floating, or a fixed potential (common potential) may be applied. In the latter case, the potential applied to the first conductive film 162 may be the same as the potential applied to the common electrode 150.

[0074] The insulating layer 164 includes, for example, a polymer material such as glass, quartz, epoxy resin, acrylic resin, polyimide resin, polyamide resin, or silicone resin. The insulating layer 164 is provided so as to overlap the entire first conductive film 162. The thickness of the insulating layer 164 is, for example, not less than 0.1 mm and not more than 1 mm. The insulating layer 164 functions as a dielectric in the metasurface 160.

[0075] The plurality of absorption control units 166 are provided so as to overlap with the first conductive film 162 via the insulating layer 164 (see Figure 2 、 Figure 3B The plurality of absorption control units 166 are arranged to surround the radio wave reflection area RA. Thus, at least one pair of absorption control units 166 that surround the radio wave reflection area RA can be selected from the plurality of absorption control units 166. Similarly to the first conductive film 162, the plurality of absorption control units 166 may be arranged to surround the four sides of the radio wave reflection area RA.

[0076] Each of the plurality of absorption control units 166 includes at least one electrically floating conductive film. Each absorption control unit 166 may be composed of a single conductive film or may include n (n is an integer greater than 2) conductive films. For example, Figure 4A As shown, each absorption control unit 166 may include two rectangular conductive films 168-1 and 168-2, or may be as shown in FIG. Figure 4B As shown, three rectangular conductive films 168-1, 168-2, and 168-3 are included.

[0077] Here, in each absorption control unit 166, the plurality of rectangular conductive films 168 are arranged parallel to one another. That is, the rectangular conductive films 168 are arranged so that their long sides are parallel. Furthermore, in each absorption control unit 166, the plurality of rectangular conductive films 168 are arranged so that they overlap one another in a direction perpendicular to the long sides (the short sides). Furthermore, in each absorption control unit 166, the plurality of rectangular conductive films 168 are preferably arranged so that the centers (or centers of gravity) of all the rectangular conductive films 168 lie on the same straight line perpendicular to the long sides.

[0078] In addition, in each absorption control unit 166, a plurality of rectangular conductive films 168 are configured to have different lengths (lengths in the long side direction) from each other. In other words, in each absorption control unit 166, there are no more than two rectangular conductive films 168 of the same length. The length L of the rectangular conductive film 168 also depends on the wavelength of the radio wave to be reflected, for example, it is not less than 0.5 mm and not more than 2 mm. The length L1 of the shortest rectangular conductive film 168 of each absorption control unit 166 can be selected, for example, from a range of not less than 0.5 mm and not more than 1.6 mm. On the other hand, the length L2 of the longest rectangular conductive film 168 of each absorption control unit 166 can be selected, for example, from a range of not less than 0.5 mm and not more than 2.0 mm (see Figure 4A ) In addition, the difference between the lengths L1 and L2 also depends on the wavelength of the radio wave to be reflected, and can be, for example, not less than 0.1 mm and not more than 0.3 mm.

[0079] The width (length in the short side direction) W of each absorption control unit 166 also depends on the wavelength of the radio wave to be reflected, and can be selected from a range of 0.05 mm to 2.0 mm. In addition, in each absorption control unit 166, the widths W of the plurality of rectangular conductive films 168 may be the same or different. For example, when each absorption control unit 166 has two rectangular conductive films 168, their widths W1 and W2 may be the same or different (see Figure 4A ).

[0080] Furthermore, in each absorption control unit 166, the distance D between adjacent rectangular conductive films 168 is also adjusted appropriately according to the wavelength of the radio wave to be reflected. For example, the distance D can be selected from a range of 0.2 mm to 1.0 mm. It should be noted that the distance D refers to the distance between the centers (or centers of gravity) of adjacent rectangular conductive films 168 in the direction of the short sides of the rectangular conductive films 168.

[0081] By adopting the above-described shape and configuration, as shown in the simulation results described in the embodiments, the metasurface 160 selectively absorbs radio waves of a desired wavelength. As a result, it is possible to suppress radio wave reflection in the frame area FA and selectively reflect radio waves in the radio wave reflection area RA. As will be described later, this characteristic facilitates precise control of the reflection direction.

[0082] In addition, the plurality of absorption control units 166 are preferably arranged so that the long side direction of the rectangular conductive film 168 is perpendicular to the adjacent absorption control units 166. For example, the plurality of absorption control units 166 are preferably arranged so that the long side direction of the rectangular conductive film 168 is alternately arranged (see FIG. Figure 3B By adopting such a configuration, both vertically polarized waves and horizontally polarized waves can be effectively absorbed. It should be noted that, when absorbing only one of the vertically polarized waves and the horizontally polarized waves, the long sides of the rectangular conductive film 168 may be parallel to each other in all the absorption control units 166.

[0083] The pitch P of the absorption control unit 166 (refer to Figure 3B ) also depends on the wavelength of the radio wave to be reflected, and can be appropriately selected from a range of 0.4 mm to 3.0 mm, for example. Preferably, the pitch P is twice the distance D. In addition, the pitch P may be the same or substantially the same as the pitch of the drive electrode 142 or the common electrode 150. Thus, as Figure 3B As shown, a pair of absorption control units 166 can be arranged in each row to sandwich a plurality of radio wave reflecting elements 140. In addition, the same number of absorption control units 166 as the number of columns can be arranged along the row direction at positions corresponding to each column. Figure 3B In the example shown, when the number of rows of the matrix formed by the plurality of driving electrodes 142 is N and the number of columns is M, the number of absorption control units 166 becomes (2N+M). However, the arrangement of the absorption control units 166 is not limited to the above arrangement. For example, Figure 5 As shown in FIG. 1 , the absorption control units 166 are arranged in a plurality of rows or columns along the sides of the radio wave reflection area FA. Figure 3B Although not shown in the figure, the absorption control units 166 may also be arranged at the corners indicated by C, that is, at positions where the arrangement direction of the absorption control units 166 arranged in the row direction intersects the arrangement direction of the absorption control units 166 arranged in the column direction. In this case, the absorption control units 166 may be arranged so that the repetitive patterns of the absorption control units 166 arranged in the row direction and the repetitive patterns of the absorption control units 166 arranged in the column direction match each other.

[0084] As described above, the frame area FA of the radio wave reflecting device 100 is provided with wiring 134 for supplying various signals. Furthermore, a driving circuit is sometimes also located in the frame area FA. Because structures such as the wiring 134 and the driving circuit also reflect radio waves, the radio waves reflected by the radio wave reflecting device 100 contain not only the desired reflected waves obtained in the radio wave reflecting area RA but also waves reflected in the frame area FA. This reduces the amplitude of the reflected waves, resulting in a decrease in reflection characteristics.

[0085] However, by configuring the metasurface 160, radio waves incident on the frame area FA can be effectively absorbed. As a result, radio waves incident on the radio wave reflecting device 100 can be selectively reflected in the radio wave reflecting area RA, thereby achieving excellent reflection characteristics with reduced amplitude of reflected waves.

[0086] 2. Modification

[0087] The configuration of the radio wave reflection device 100 according to the embodiment of the present invention is not limited to the configuration described above, and various modifications are possible. Modifications of the radio wave reflection device 100 will be described below.

[0088] (1) Absorption control unit

[0089] like Figure 4C As shown, each absorption control unit 166 can also be composed of a single L-shaped conductive film 170. Although it also depends on the wavelength of the radio wave to be reflected, the length L of the mutually orthogonal arms (two straight portions separated by the bend) of the L-shaped conductive film 170 can be appropriately selected, for example, from a range of 0.5 mm to 2.0 mm, and the width W of the arm can be appropriately selected, for example, from a range of 0.1 mm to 0.5 mm. The two arms are preferably configured in a manner orthogonal to each other. As shown in the embodiment, even if each absorption control unit 166 is composed of a single L-shaped conductive film 170, it can effectively absorb radio waves in a wider frequency range. In addition, the L-shaped conductive film 170 can be said to be composed of two orthogonal conductive films, so each absorption control unit 166 can absorb the polarized waves of both. Therefore, the configuration direction of the L-shaped conductive film 170 can also be the same between multiple absorption control units 166.

[0090] (2) Metasurface Configuration

[0091] In the radio wave reflection device 100 having the above-mentioned structure, the metasurface 160 is provided on the counter substrate 104, but the position of the metasurface 160 is not limited to the position in the above-mentioned structure. Figure 6As shown, the opposing substrate 104 is arranged on the super surface 160. In this case, the common electrode 150 and the first conductive film 162 can also be formed on the insulating layer 164 directly or through the outer coating 132. Therefore, the common electrode 150 and the first conductive film 162 can exist in the same layer. The opposing substrate 104 can be fixed to the absorption control unit 166 and the insulating layer 164 using an adhesive layer 136, or the absorption control unit 166, the insulating layer 164, the first conductive film 162, the common electrode 150 and the second orientation film 148 can be stacked in sequence on the opposing substrate 104 and attached to the array substrate 102. It should be noted that, although not shown in the figure, the opposing substrate 104 can also be not provided on the super surface 160, but the insulating layer 164 and the absorption control unit 166 of the super surface 160 can be directly exposed to the atmosphere.

[0092] Or, as Figure 7 As shown, the insulating layer 164 need not cover the entire counter substrate 104 but may include an opening 164a that exposes all or at least a portion of the radio wave reflecting area RA. The provision of the opening 164a prevents absorption of radio waves incident on the radio wave reflecting area RA by the insulating layer 164. Furthermore, when high light transmittance is required for the radio wave reflecting device 100, a decrease in light transmittance due to the insulating layer 164 can be avoided.

[0093] Or, as Figure 8 As shown, an insulating layer 164 may be used instead of the seal 152. In other words, the insulating layer 164 may function as a seal, and the array substrate 102 and the counter substrate 104 may be fixed to each other by the insulating layer 164. In this case, the first conductive film 162 may be provided on the planarization film 116 or the interlayer insulating film 118. In addition, the first conductive film 162 and the drive electrode 142 may be formed simultaneously in a manner that they exist on the same layer. On the other hand, the absorption control unit 166 may be provided on the counter substrate 104 directly or via the outer coating 132. In addition, the absorption control unit 166 and the common electrode 150 may be formed simultaneously in a manner that they exist on the same layer.

[0094] Or, as Figure 9 As shown, the first conductive film 162 may be provided between the array substrate 102 and the wiring 134. Although not shown, if the wiring 134 and the terminals 128 and 130 are present in the same layer, the first conductive film 162 and the gate electrode 122 may be formed simultaneously in the same layer.

[0095] (3) Direction of incident radio waves

[0096] In the radio wave reflection device 100 having the above-mentioned structure, radio waves are incident from the common electrode 150 side (i.e., the counter substrate 104 side), but the radio wave reflection device 100 can also be configured so as to reflect radio waves incident from the driving electrode 142 side (i.e., the array substrate 102 side) in an optional direction. For example, Figure 10 As shown, the common electrode 150 is constructed as a patch electrode in a manner shared by all or a plurality of radio wave reflecting elements 140. On the other hand, the driving electrode 142 is provided in a manner having a shape with high symmetry such as a regular polygon or a circle. The size of the driving electrode 142 can be appropriately adjusted according to the wavelength of the radio wave to be reflected, for example, the length in the row direction and the length in the column direction can be set to be greater than 1 mm and less than 40 mm. In addition, the metasurface 160 is provided on the lower side of the array substrate 102. That is, the metasurface 160 is constructed in a manner such that the first conductive film 162 is located above the absorption control unit 166 via the insulating layer 164, and the array substrate 102 and the opposing substrate 104 are arranged on the side of the first conductive film 162. The metasurface 160 can be fixed to the array substrate 102 using an adhesive layer 136.

[0097] In addition, with Figure 7 Similarly to the modified example shown, the insulating layer 164 does not need to cover the entire array substrate 102, and may also have an opening 164a ( Figure 11 ). In addition, Figure 12 As shown, the array substrate 102 can also be arranged below the metasurface 160. That is, the metasurface 160 can also be arranged between the array substrate 102 and the wiring 134. In addition, although not shown, the array substrate 102 can also be placed without being below the metasurface 160, and the absorption control unit 166 and the insulating layer 164 can be directly exposed to the atmosphere. In this case, the insulating layer 164 functions as the array substrate 102, or a portion of the array substrate 102 functions as the insulating layer 164.

[0098] By adopting the above configuration, radio waves incident on the frame area FA from the array substrate 102 side can be absorbed by the metasurface 160 , thereby providing the radio wave reflection device 100 having excellent reflection characteristics.

[0099] Example

[0100] 1. Example 1

[0101] In this embodiment, the results of analyzing, by simulation, the effects of the number and length differences of the rectangular conductive films 168 on the radio wave absorption characteristics of the metasurface 160 are described.

[0102] like Figure 13AAs shown, three types of model metasurfaces 1 to 3 are constructed. Model metasurfaces 1 to 3 all have a first conductive film 162, an insulating layer 164, and an absorption control unit 166, but the length or configuration of the rectangular conductive film 168 constituting the absorption control unit 166 is different. The conductivity of the first conductive film 162 and the rectangular conductive film 168 is set to 3.5×107 S / m, the dielectric constant of the insulating layer 164 is set to 5.4, which is the relative dielectric constant of glass, and the thickness of the insulating layer 164 is set to 0.5 mm. Other parameters of model metasurfaces 1 to 3 are as follows Figure 13A As shown, a simulation was performed by fixing the length of one rectangular conductive film 168 at 1.5 mm and varying the length of the other rectangular conductive film 168 in the model metasurface 3. The simulation was performed under the condition that the absorption control unit 166 was exposed to air.

[0103] Figure 14 The simulation results are shown. Figure 14 The vertical axis of the graph shown represents the attenuation of the amplitude of the reflected wave using common logarithms, and the smaller the value, the stronger the absorption of the radio wave. Figure 14 As can be understood, in the model metasurface 1 composed of a single rectangular conductive film 168 and the model metasurface 2 composed of two rectangular conductive films 168 of the same length, the electromagnetic wave absorption is small in the frequency band range of 10GHz to 60GHz. In contrast, it can be seen that in the model metasurface 3 composed of two rectangular conductive films 168 of different lengths, electromagnetic waves are strongly absorbed in a specific frequency band. The intensity of the electromagnetic wave absorption and the frequency of the absorbed electromagnetic waves depend on the difference in length between the two rectangular conductive films 168. The above results clearly show that by providing two rectangular conductive films 168 of different lengths, electromagnetic waves can be effectively absorbed, and by appropriately adjusting the difference in length, the intensity of the electromagnetic wave absorption and the frequency of the absorbed electromagnetic waves can be controlled.

[0104] 2. Example 2

[0105] In this embodiment, the results of analyzing, by simulation, the effect of the length difference between the two rectangular conductive films 168 on the radio wave absorption characteristics of the metasurface 160 are described.

[0106] like Figure 13B As shown in FIG. 1 , a model metasurface 4 having two rectangular conductive films 168 was constructed. The length L1 of one rectangular conductive film 168 was fixed at 1.40 mm, 1.45 mm, 1.50 mm, 1.55 mm, or 1.60 mm, while the length L2 of the other rectangular conductive film 168 was varied to perform simulations. The parameters of the model metasurface 4 are shown in FIG. Figure 13B As shown, other parameters and simulation setting conditions are the same as those in the first embodiment.

[0107] The simulation results are Figure 15A Shown in. Figure 15A The vertical axis of the graph represents the minimum value of the reflected wave amplitude using common logarithm. Figure 15A It can be seen that the absorption characteristics vary depending on the difference in length of the rectangular conductive film 168 , and that radio waves can be strongly absorbed when the difference is between 0.1 mm and 0.2 mm. Figure 15B This is a graph showing the frequency at which the radio wave absorption intensity becomes maximum relative to the difference in length of the rectangular conductive film 168. Figure 15B As can be understood, when there is no length difference between the rectangular conductive films 168 (ΔL = 0 mm), the frequency of the absorbed radio waves is approximately 35 GHz. However, by providing a difference of 0.05 mm or more between the two, wavelengths with frequencies between 40 GHz and 60 GHz can be effectively absorbed. The above results show that by appropriately setting the length of the two rectangular conductive films 168 and the difference between them, the frequency of the absorbed radio waves and their absorption characteristics can be controlled.

[0108] 3. Example 3

[0109] In this embodiment, the results obtained by analyzing the effect of the distance D between the two rectangular conductive films 168 on the radio wave absorption characteristics of the metasurface 160 through simulation are described.

[0110] use Figure 16A The model metasurface 5 shown in the figure changes the distance D and uses simulation to analyze the radio wave absorption characteristics. The parameters of the model metasurface 5 are as follows Figure 16A As shown, other parameters and simulation setting conditions are the same as those in the first embodiment.

[0111] Figure 17A The simulation results are shown. Figure 17A The vertical axis of the graph uses common logarithms to represent the attenuation of the amplitude of the reflected wave. The smaller the value, the stronger the absorption of the radio wave. Figure 17A As shown, it can be seen that varying the distance D significantly changes the absorption characteristics, and depending on the distance D, the metasurface 160 strongly absorbs radio waves in a specific frequency band. In other words, by appropriately setting the distance D, the frequency of the absorbed radio waves can be controlled. Furthermore, it can be seen that by setting the area occupied by each absorption control unit 166, that is, the distance D between the rectangular conductive films 168, to 0.4 to 0.6 times the pitch P, even stronger radio wave absorption is achieved.

[0112] 4. Example 4

[0113] In this embodiment, the results of analyzing the effect of the width W of the rectangular conductive film 168 on the radio wave absorption characteristics of the metasurface 160 using simulations are described.

[0114] use Figure 16BThe model metasurface 6 shown in FIG. 1 changes the width W of the two rectangular conductive films 168 and uses simulation to analyze the electromagnetic wave absorption characteristics. The parameters of the model metasurface 6 are as follows: Figure 16B As shown, other parameters and simulation setting conditions are the same as those in the first embodiment.

[0115] Figure 17B The simulation results are shown. Figure 17B The vertical axis of the graph uses common logarithms to represent the attenuation of the amplitude of the reflected wave. The smaller the value, the stronger the absorption of the radio wave. Figure 17B As shown, varying the width W significantly changes the absorption characteristics, and metasurface 160 strongly absorbs radio waves in a specific frequency band depending on the width W. In other words, by appropriately setting the width W, the frequency of the absorbed radio waves can be controlled. Furthermore, it can be seen that high absorption characteristics are achieved when the width W is between 1% and 10% of the pitch P of the absorption control units 166.

[0116] 5. Example 5

[0117] In this embodiment, the radio wave absorption characteristics when a plurality of absorption control units 166 each including two rectangular conductive films 168 are arranged alternately in the longitudinal direction of the rectangular conductive films 168 are analyzed by simulation, and the obtained results are described.

[0118] use Figure 18A The model metasurface 7 shown in the figure uses simulation to analyze the absorption characteristics of horizontally polarized waves and vertically polarized waves. In the model metasurface 7, there are four absorption control units 166 each having two rectangular conductive films 168. The long side directions of the rectangular conductive films 168 of two of the absorption control units 166 are orthogonal to the long side directions of the other absorption control units 166. Other parameters of the model metasurface 7 are as follows: Figure 18A As shown, the parameters of each absorption control unit 166 are as follows Figure 18B The other parameters and simulation setting conditions are the same as those in Example 1.

[0119] Figure 19 The simulation results are shown. Figure 19 The vertical axis of the graph uses common logarithms to represent the attenuation of the amplitude of the reflected wave. The smaller the value, the stronger the absorption of the radio wave. Figure 19 As shown, the model metasurface 7 effectively absorbs both horizontally polarized and vertically polarized components. This result indicates that, when the absorption control unit 166 includes multiple rectangular conductive films 168, the metasurface 160 including multiple absorption control units 166 with different longitudinal directions of the rectangular conductive films 168 can effectively absorb radio waves.

[0120] 6. Example 6

[0121] In this embodiment, the results of analyzing, by simulation, the radio wave absorption characteristics of a metasurface having an absorption control unit 166 composed of three rectangular conductive films 168 will be described.

[0122] like Figure 20 As shown in FIG, model metasurfaces 8 and 9 having three rectangular conductive films 168 were constructed. In model metasurface 8, the lengths of the rectangular conductive films 168 are different from each other, but the lengths of the rectangular conductive films 168 of model metasurface 9 are the same. It should be noted that as a comparison object, model metasurfaces 10 and 11 having square and circular conductive films 172, respectively, were constructed and similarly analyzed based on simulations. The parameters of these model metasurfaces 8 to 11 are as follows: Figure 20 As shown, other parameters and simulation setting conditions are the same as those in Example 1.

[0123] The results are Figure 21 Shown in. Figure 21 The vertical axis of the graph represents the attenuation of the amplitude of the reflected wave using common logarithms, and the smaller the value, the stronger the absorption of the radio wave. Figure 21 It can be easily understood that the model metasurfaces 10 and 11 do not show significant absorption in the frequency band within the range of 10 GHz to 60 GHz. Similarly, the model metasurface 8 having rectangular conductive films 168 of the same length also shows radio wave absorption near 53 GHz, but its absorption intensity is extremely small. In contrast, it was confirmed that the model metasurface 9 having rectangular conductive films 168 of different lengths shows strong radio wave absorption near 48 GHz and 54 GHz. The above results suggest that the number of rectangular conductive films 168 constituting each absorption control unit 166 is not limited to two, and the use of three or more rectangular conductive films 168 can also constitute a metasurface 160 that effectively absorbs radio waves.

[0124] 7. Example 7

[0125] In this embodiment, the description is made on Figure 6 The results are obtained by simulation analysis of the radio wave absorption characteristics of the metasurface 160 in the radio wave reflection device 100 having the structure shown.

[0126] In this embodiment, the Figure 13B The model metasurface 4 is shown. The length L1 of one rectangular conductive film 168 is fixed to 0.90 mm, 0.95 mm, 1.00 mm, 1.05 mm, or 1.10 mm, while the length L2 of the other rectangular conductive film 168 is varied to simulate the model metasurface 4. Figure 13B As shown in FIG, other parameters are the same as those in Example 1. However, in the Figure 6In the radio wave reflection device 100 of the structure shown, since the opposing substrate 104 is located on the metasurface 160, the simulation was performed in the same manner as in Example 1 under the following conditions: the absorption control unit 166 of the model metasurface 4 was not exposed to the air and a layer with a thickness of 0.5 mm and a relative dielectric constant of 5.4 existed on the absorption control unit 166.

[0127] The simulation results are Figure 22A Shown in. Figure 22A The vertical axis of the graph represents the minimum value of the reflected wave amplitude using common logarithm. Figure 22A It can be seen that the absorption characteristics vary depending on the difference in length of the rectangular conductive film 168 , and that radio waves can be strongly absorbed when the difference is between 0.1 mm and 0.2 mm. Figure 22B This is a graph showing the frequency at which the radio wave absorption intensity becomes maximum relative to the difference in length of the rectangular conductive film 168. Figure 22B As can be understood, the maximum absorption frequency varies depending on the length difference of the rectangular conductive film 168. Figure 6 In the radio wave reflecting device 100 having the structure shown, the frequency of the absorbed radio wave and its absorption characteristics can be controlled by appropriately setting the lengths of the two rectangular conductive films 168 and the difference therebetween.

[0128] 8. Example 8

[0129] In this embodiment, the results of simulation analysis of the radio wave absorption characteristics of a metasurface including the absorption control unit 166 having the L-shaped conductive film 170 are described.

[0130] exist Figure 23 A schematic top view of the constructed model metasurface 12 is shown in FIG. In this embodiment, similarly to Example 7, a simulation was performed in the same manner as in Example 1, under the conditions that the absorption control unit 166 was not exposed to the air and a layer with a thickness of 0.5 mm and a relative dielectric constant of 5.4 existed on the absorption control unit 166. The parameters of the model metasurface 12 are as follows: Figure 23 As shown, other parameters are the same as those in Example 1.

[0131] exist Figure 24 The simulation results are shown in . Figure 24 The vertical axis of the graph uses common logarithms to represent the attenuation of the amplitude of the reflected wave. The smaller the value, the stronger the absorption of the radio wave. Figure 24As can be understood, the model metasurface 12 composed of the L-shaped conductive film 170 also strongly absorbs radio waves in a specific frequency band. Compared to the model metasurface 3 having the rectangular conductive film 168, the frequency bandwidth of the absorbed radio waves is wider. The model metasurface 12 can effectively absorb radio waves in a wide frequency band ranging from approximately 50 GHz to approximately 45 GHz. In addition, it can be seen that by appropriately adjusting the length L and width W of the arms of the L-shaped conductive film 170, the frequency band of the absorbed radio waves can be controlled.

[0132] The various embodiments described above as embodiments of the present invention may be implemented in combination as appropriate, as long as they do not conflict with each other. Furthermore, solutions obtained by those skilled in the art by appropriately adding, deleting, or modifying the design of components, or by adding, omitting, or modifying conditions based on the radio wave reflection elements or radio wave reflection devices of the various embodiments, as long as they conform to the spirit of the present invention, are also within the scope of the present invention.

[0133] Even if there are other effects different from the effects brought about by the schemes of the above-mentioned embodiments, as long as they are clearly known from the description of this specification or can be easily predicted by those skilled in the art, they are of course understood to be the effects brought about by the present invention.

[0134] Description of Reference Numerals

[0135] 100: Radio wave reflection device, 102: Array substrate, 104: Counter substrate, 106: Scan line driver circuit, 108: Signal line driver circuit, 110: Terminal, 112: Undercoat layer, 114: Interlayer insulating film, 116: Planarization film, 118: Interlayer insulating film, 120: Transistor, 122: Gate electrode, 124: Gate insulating film, 126: Semiconductor film, 128: Terminal, 130: Terminal, 132: Overcoat layer, 134: Wiring, 136: Adhesive layer, 140 : Radio wave reflecting element, 142: Driving electrode, 144: First orientation film, 146: Liquid crystal layer, 148: Second orientation film, 150: Common electrode, 152: Sealing member, 160: Supersurface, 162: First conductive film, 164: Insulating layer, 164a: Opening, 166: Absorption control unit, 168: Rectangular conductive film, 168-1: Rectangular conductive film, 168-2: Rectangular conductive film, 168-3: Rectangular conductive film, 170: L-shaped conductive film, 172: Conductive film.

Claims

1. A radio wave reflecting device comprising: An array substrate having an electric wave reflecting area and a frame area surrounding the electric wave reflecting area; a plurality of radio wave reflecting elements on the radio wave reflecting area; a wiring, the wiring being electrically connected to at least one of the plurality of radio wave reflecting elements, and at least a portion of the wiring overlapping with the frame area; as well as a metasurface, wherein the metasurface overlaps the wiring in the border area, The metasurface comprises: a first conductive film; a plurality of absorption control units, each of the plurality of absorption control units overlapping the first conductive film and having at least one conductive film; and an insulating layer between the first conductive film and the plurality of absorption control units.

2. The radio wave reflection device according to claim 1, wherein: The at least one conductive film is electrically floating.

3. The radio wave reflection device according to claim 1, wherein: The at least one conductive film includes first to nth rectangular conductive films that are parallel to each other and have different lengths. Here, n is an integer greater than or equal to 2.

4. The radio wave reflection device according to claim 3, wherein: The long side directions of the first to n-th rectangular conductive films are perpendicular to each other between adjacent absorption control units.

5. The radio wave reflection device according to claim 3, wherein: n is 2 or 3.

6. The radio wave reflection device according to claim 3, wherein: The first to n-th rectangular conductive films overlap with each other in a direction perpendicular to the longitudinal direction.

7. The radio wave reflection device according to claim 1, wherein: The at least one conductive film is formed from a single L-shaped conductive film.

8. The radio wave reflection device according to claim 7, wherein: The two straight portions of the L-shaped conductive film, which are present across the bent portion, are perpendicular to each other.

9. The radio wave reflection device according to claim 1, wherein: A counter substrate is also provided on the array substrate. The metasurface is located on the opposing substrate, The plurality of absorption control units are located on the first conductive film via the insulating layer.

10. The radio wave reflection device according to claim 1, wherein A counter substrate is further provided on the array substrate across the super surface. The plurality of absorption control units are located on the first conductive film via the insulating layer.

11. The radio wave reflection device according to claim 10, wherein: The insulating layer has an opening, At least a portion of the plurality of radio wave reflecting elements is exposed from the opening.

12. The radio wave reflection device according to claim 1, wherein: A counter substrate is also provided on the array substrate. The plurality of absorption control units are located on the first conductive film via the insulating layer. The insulating layer fixes the array substrate and the counter substrate.

13. The radio wave reflection device according to claim 1, wherein The plurality of absorption control units are located on the first conductive film via the insulating layer. The first conductive film is located between the array substrate and the wiring.

14. The radio wave reflection device according to claim 1, wherein The metasurface is located below the array substrate. The plurality of absorption control units are located below the first conductive film via the insulating layer.

15. The radio wave reflection device according to claim 14, wherein: The insulating layer has an opening overlapping with the radio wave reflecting region.

16. The radio wave reflection device according to claim 1, wherein The metasurface is located between the array substrate and the wiring. The plurality of absorption control units are located below the first conductive film via the insulating layer.

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