Display Module

Abstract

This display module is provided with: a display; a transparent antenna disposed on the upper side of the display, and has a transparent substrate and an antenna pattern formed on the transparent substrate; and an artificial magnetic conductor disposed in a layer lower than the transparent antenna. The artificial magnetic conductor includes a periodic structure layer capable of selecting a specific frequency and a background conductor, the antenna pattern of the transparent antenna and the periodic structure layer of the artificial magnetic conductor each comprise a mesh-shaped conductor, the mesh-shaped conductor comprises a transparent conductor in which wiring widths w81, w82 are 5 μm or less, and wiring pitches p81, p82 are set so that a transmittance of 70% or more can be obtained in visible light, and a relationship of h1 < h2 is established where h1 is the distance from the antenna pattern of the transparent antenna to the periodic structure layer of the artificial magnetic conductor, and h2 is the distance from the periodic structure layer to the background conductor in the artificial magnetic conductor.

Description

[Technical field]

[0001] The present invention relates to a display module comprising an antenna and an artificial magnetic conductor. [Background technology]

[0002] In recent years, the fifth generation mobile communication system (5G) and the sixth generation mobile communication system (6G) have been developed as communication technologies for mobile communication devices such as smartphones, tablets, mobile phones, and laptops.

[0003] Here, millimeter waves, the frequency band used for 5G, are highly directional, have a relatively short reach, and are easily blocked by metal, etc., so a technology has been proposed to place transparent antennas on displays (OLED, LCD, LED) and touch panels (including display-integrated metal thin-line panels) as 5G antennas.

[0004] However, when a metal conductor with high resistance, such as a display or touch panel, is placed close to the antenna, the metal conductor absorbs radio waves without reflecting them, causing the antenna to have a narrow bandwidth, resulting in a large loss of gain in transmission and reception and a decrease in radiation efficiency. Therefore, as shown in Fig. 1, it has been proposed to provide an artificial magnetic conductor (AMC) between the antenna and the display or touch panel so as to make the reflection phase of the antenna zero (Patent Document 1).

[0005] The AMC in Patent Document 1 is composed of a periodic structure layer. Here, there are two types of AMC: an AMC composed of only a periodic structure, and an AMC composed of two layers, a periodic structure layer and a background layer. It is known that an AMC composed of two layers, a periodic structure layer and a background layer, has better antenna reflection performance as a magnetic wall than an AMC composed of only a periodic structure. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 10,326,196 Summary of the Invention [Problem to be solved by the invention]

[0007] AMCs, which are made up of two layers, a periodic structure layer and a background layer, are available in a top-bottom conductive structure with vias that magnetically connect the periodic structure layer and the background layer, and a top-bottom non-conductive structure without vias. However, it is known that AMCs with a top-bottom through structure are complicated to manufacture and require many manufacturing steps.

[0008] Furthermore, even when using an AMC consisting of two layers, a periodic structure layer and a background layer, the total thickness including the AMC, antenna, and display tends to be large, posing a challenge of how to reduce the total thickness.

[0009] In view of the above circumstances, the present invention aims to provide a display module that can significantly reduce antenna gain loss, contains an artificial magnetic conductor that is not complicated to manufacture, and minimizes the increase in lamination thickness due to the artificial magnetic conductor. [Means for solving the problem]

[0010] In order to solve the above problems, a display module according to one aspect of the present invention comprises: A display and a transparent antenna disposed above the display, the transparent antenna having a transparent substrate and an antenna pattern formed on the transparent substrate; An artificial magnetic conductor arranged below the transparent antenna; Equipped with The artificial magnetic conductor comprises: A periodic structure layer, and Including a background conductor; The antenna pattern of the transparent antenna and the periodic structure layer of the artificial magnetic conductor are composed of a mesh-shaped conductor. The mesh-shaped conductor is a transparent conductor with a wiring width of 5 μm or less and a wiring pitch determined so as to obtain a transmittance of 70% or more in visible light. Let the distance from the antenna pattern of the transparent antenna to the periodic structure layer of the artificial magnetic conductor be h1. When the distance from the periodic structure layer to the background conductor in the artificial magnetic conductor is h2, There is a relationship of h1 < h2.

Advantages of the Invention

[0011] According to one aspect, in a display module, it is possible to significantly suppress the gain loss of the antenna, contain an artificial magnetic conductor that is not complicated to manufacture, and minimize the increase in the stacking thickness due to the artificial magnetic conductor.

Brief Description of the Drawings

[0012] [Figure 1] Cross-sectional exploded view of an AMC-mounted display module according to a conventional example. [Diagram 2] Overall view of an electronic device with a display and a diagram showing the position of a transparent antenna according to the present invention. [Diagram 3] Cross-sectional view of the AA plane of the electronic device in FIG. 2. [Figure 4] Cross-sectional exploded view showing a display module according to the first embodiment of the present invention. [Figure 5A] Explanation diagram of the reflection of electromagnetic waves by a metal conductor. [Figure 5B] Explanation diagram of the reflection of electromagnetic waves by an AMC. [Figure 6] Explanation diagram of a transparent antenna provided with a periodic structure layer according to the first embodiment of the present invention. [Figure 7A] Top view of the transparent antenna of the present invention. [Figure 7B] Bottom view of the transparent antenna provided with the periodic structure layer of the present invention. [Figure 8]FIG. 2 is an explanatory diagram of a transparent conductor constituting an antenna pattern and a periodic structure layer of the present invention. [Figure 9A] An explanatory diagram of a typical up-down conduction type AMC. [Figure 9B] An explanatory diagram of a typical AMC with no top and bottom conduction. [Figure 10A] An explanatory diagram of an AMC with a patch-type periodic structure and no electrical continuity above or below. [Figure 10B] An explanatory diagram of an AMC with a top-bottom non-conductive structure and a hole-type periodic structure. [Figure 11] FIG. 13 is a diagram showing a modified example of a resonant element of a periodic structure layer of an AMC according to the present invention. [Figure 12] Schematic diagram of the sensor pattern of a typical projected capacitive touch panel. [Figure 13] FIG. 2 is a cross-sectional view of a touch panel. [Figure 14] Schematic diagram of a pseudo-AMC consisting of one floating conductor, an adhesive layer, and a metal conductor that mimics a touch panel. [Figure 15A] FIG. 15 is a diagram showing characteristic values ​​of reflection amplitude parameters when the resistance value of the metal conductor is changed from 0 to 2.4 Ω / sq in the pseudo AMC of FIG. 14. [Figure 15B] FIG. 15 is a diagram showing characteristic values ​​of reflection amplitude parameters when the resistance value of the metal conductor in the pseudo-AMC of FIG. 14 is changed from 2.8 to 10 Ω / sq. [Figure 16A] 15 is a diagram showing characteristic values ​​of reflection phase parameters when the resistance value of the metal conductor is changed from 0 to 2.4 Ω / sq in the pseudo AMC of FIG. 14. [Figure 16B] 15 is a diagram showing characteristic values ​​of reflection phase parameters when the resistance value of the metal conductor is changed from 2.8 to 10 Ω / sq in the pseudo AMC of FIG. 14. [Figure 17] Schematic diagram of a pseudo-AMC consisting of one floating conductor, an adhesive layer, and a metal conductor that mimics a touch panel. [Figure 18] 18 is a diagram showing characteristic values ​​of reflection amplitude parameters when the size of the floating conductor is changed in the pseudo AMC of FIG. 17. [Figure 19]18 is a diagram showing characteristic values ​​of reflection phase parameters when the size of the floating conductor is changed in the pseudo AMC of FIG. 17. [Figure 20] Schematic diagram of a measurement model consisting of a transparent antenna and an adhesive layer of the present invention. [Figure 21] Schematic diagram of a pseudo display module composed of a transparent antenna of the present invention, a periodic structure layer provided on the underside of the transparent antenna, an adhesive layer, and a metal conductor simulating a touch panel. [Figure 22] Schematic diagram of a measurement model of a comparative example that is composed of a transparent antenna, an adhesive layer, and a metal conductor that mimics a touch panel. [Diagram 23] Table showing maximum gains for the measurement models of Figures 20, 21, and 22. [Figure 24] FIG. 4 is an exploded sectional view showing a display module according to a modified example of the first embodiment of the present invention. [Diagram 25] FIG. 6 is an exploded sectional view showing a display module according to a second embodiment of the present invention. [Figure 26] FIG. 11 is a cross-sectional view of a display panel according to a second embodiment. [Figure 27] FIG. 11 is an exploded sectional view showing a display module according to a modified example of the second embodiment of the present invention. [Figure 28] FIG. 11 is an exploded sectional view showing a display module according to a third embodiment of the present invention. [Figure 29] FIG. 13 is an exploded sectional view showing a display module according to a first modified example of the third embodiment of the present invention. [Diagram 30] FIG. 13 is an exploded sectional view showing a display module according to Modification 2 of the third embodiment of the present invention. [Diagram 31] FIG. 13 is an exploded sectional view showing a display module according to Modification 3 of the third embodiment of the present invention. [Diagram 32] FIG. 11 is an exploded sectional view showing a display module according to a fourth embodiment of the present invention. [Diagram 33] FIG. 13 is an exploded sectional view showing a display module according to a modified example of the fourth embodiment of the present invention. [Diagram 34] FIG. 11 is an exploded sectional view showing a display module according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same components are denoted by the same reference numerals, and duplicated explanations may be omitted. Hereinafter, an embodiment of the present invention using a transparent antenna will be described.

[0014] The transparent antenna mounted on the display module of the present invention is applicable to the fifth generation mobile communication system (5G), for example.

[0015] In 5G frequencies, one frequency band is 24.2 to 29.5 GHz, and the second frequency band is The first frequency band is 37.3 to 40 GHz, and the third frequency band is 1.0 to 5.0 GHz, which is called the Sub6 band (5G band below 6 GHz). The antenna is configured to resonate in at least one of the three frequency bands listed above in the 5G band.

[0016] The display module according to the present invention will be described in the following order. 1. Electronic devices equipped with display modules 2-1. Display module 1 according to the first embodiment of the present invention 2-2. Structure of a transparent antenna with a periodic structure layer on the underside 2-3. Structure of transparent conductor 2-4.AMC configuration example 2-5. Touch panel configuration 3-1. Measurement model configuration and characteristics of pseudo-AMC minimum unit 1 3-2. Measurement model configuration and characteristics of pseudo-AMC minimum unit 2 3-3. Measurement model configuration and characteristics of antenna alone, pseudo display module with AMC, and pseudo display module for comparison 4. Display module 1A according to a modification of the first embodiment of the present invention 5-1. Display module 2 according to the second embodiment of the present invention 5-2. Display panel configuration 5-3. Display module 2A according to a modified example of the second embodiment of the present invention 6-1. Display module 3 according to the third embodiment of the present invention 6-2. Display module 3A according to modification 1 of the third embodiment of the present invention 6-3. Display module 3B according to modified example 2 of the third embodiment of the present invention 6-4. Display module 3C according to modification 3 of the third embodiment of the present invention 7-1. Display module 4 according to the fourth embodiment of the present invention 7-2. Display module 4A according to a modification of the fourth embodiment of the present invention 8. Display module 5 according to the fifth embodiment of the present invention

[0017] (1. Electronic device equipped with a display module) 2 and 3, the configuration of an electronic device 200, which is an example of a communication device equipped with a display module 1 including a transparent antenna 100 of the present invention, will be described. Fig. 2 is an overall view of the electronic device 200 equipped with the display module 1 of the present invention, and a diagram showing the position of the transparent antenna 100. Fig. 3 is a cross-sectional view of the A-side of the electronic device 200 of Fig. 2.

[0018] 2 and 3, the X direction indicates the horizontal direction of the electronic device 200, the Y direction indicates the vertical direction of the electronic device 200, and the Z direction indicates the height direction of the electronic device 200. In the following, the XYZ coordinate system is defined and described. For convenience of explanation, the planar view below refers to the XY plane view, and the description is given using the up-down direction with the +Z direction side being the upper side and the -Z direction side being the lower side, and the horizontal direction (side) with respect to the up-down direction, but these do not represent the universal up-down and horizontal directions.

[0019] In addition, in the directions of parallel, right-angled, orthogonal, horizontal, vertical, up-down, left-right, etc., deviations that do not impair the effects of the disclosure in the embodiments are permitted. In addition, the X direction, Y direction, and Z direction respectively represent directions parallel to the X axis, the Y axis, and the Z axis. The X direction, the Y direction, and the Z direction are perpendicular to each other. The XY plane, the YZ plane, and the ZX plane respectively represent imaginary planes parallel to the X direction and the Y direction, imaginary planes parallel to the Y direction and the Z direction, and imaginary planes parallel to the Z direction and the X direction.

[0020] The electronic device 200 is, for example, an information processing terminal such as a smartphone, a tablet computer, a notebook PC (Personal Computer), etc. In addition, the electronic device 200 is not limited to these, and may be, for example, a structure such as a pillar or a wall, a digital signage, an electronic device including a display panel in a train, or an electronic device including various display panels in a vehicle.

[0021] 2 and 3, a display module 1 capable of performing a display function is disposed on the entire top surface or at least a part of the top surface of the electronic device 200. The transparent antenna 100 of the present invention is disposed above a touch panel 230 on a display panel 220. The transparent antenna 100 of the present invention is visible from outside the electronic device 200 through a transparent cover 240, and is transparent so that the display panel 220 can be viewed from the outside through the transparent antenna 100.

[0022] 3, in electronic device 200, display panel 220, touch panel 230, transparent antenna 100, and transparent cover 240 are collectively referred to as display module 1 (also referred to as display module).

[0023] In addition to the display module 1, the electronic device 200 includes a housing 210, a wiring board 250, electronic components 260A, 260B, 260C, and 260D, a battery 270, and the like.

[0024] 2 and 3 show an example in which the electronic device 200 in which the transparent antenna 100 is mounted is a smartphone, but the electronic device in which the transparent antenna of the present invention is mounted may have another configuration as long as it includes a housing 210, a transparent cover 240, and a display panel 220. In addition, the electronic device 200 may not be provided with a touch panel 230.

[0025] Housing 210 is, for example, a case made of metal and / or resin, and covers the bottom and side surfaces of electronic device 200. Housing 210 has opening end 211 which is the upper end of the peripheral wall, and transparent cover 240 is attached to opening end 211. Housing 210 has storage section 212 which is an internal space communicating with opening end 211, and storage section 212 stores wiring board 250, electronic components 260A to 260D, battery 270, etc.

[0026] Transparent cover 240, which is an example of a cover glass, is a transparent glass plate provided on the top surface and has a size that matches open end 211 of housing 210 in a plan view. In this example, transparent cover 240 is mostly flat, and both ends in the lateral direction (+Y direction) are gently curved downward. However, the transparent cover 240 may be a flat glass plate in the horizontal direction. The end portion may be gently curved downward. Here, a form in which transparent cover 240 is made of glass will be described, but transparent cover 240 may be made of resin.

[0027] Transparent cover 240 is attached to open end 211 of housing 210, thereby sealing storage section 212 of housing 210.

[0028] The upper surface of the transparent cover 240 is an example of the outer surface of the transparent cover 240, and the lower surface of the transparent cover 240 is an example of the inner surface of the transparent cover 240. The transparent antenna 100 and the touch panel 230 are provided on the inner surface side of the transparent cover 240. Since the transparent cover 240 is transparent, the touch panel 230 and the display panel 220 provided inside can be seen through the transparent cover 240 from the outside of the electronic device 200.

[0029] Electronic components 260A to 260C are mounted on the wiring board 250. A power feed line extending from the power feed portion of the transparent antenna is connected to the wiring board 250. The wiring board 250 and the power feed portion of the transparent antenna 100 are connected to each other via a connector, an ACF (Anisotropic Conductive Film), etc. Alternatively, the connection may be made using other components.

[0030] As an example, the electronic component 260A is a communication module that is connected to a power supply portion of the transparent antenna 100 via wiring on the wiring board 250 and processes signals transmitted or received via the transparent antenna 100. The central electronic component 260B is, for example, a camera.

[0031] The electronic components 260C and 260D are, for example, components that perform information processing related to the operation of the electronic device 200, and are, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), etc. Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), Input / Output It is realized by a computer including an interface, an internal bus, and the like.

[0032] The battery 270 is a rechargeable secondary battery, and supplies the power required for the operation of the display module 1, the electronic components 260A to 260D, and the like.

[0033] (2-1. Display module according to the first embodiment) Next, a description will be given of the configuration of the display module 1 according to the first embodiment.

[0034] Although not shown in Fig. 3, as shown in Fig. 4, the display module 1 has a first adhesive layer 281, a polarizing plate 291, and a second adhesive layer 282 between the touch panel 230 and the transparent cover 240. The first adhesive layer 281 and the second adhesive layer 282 are made of a transparent optical adhesive OCA (Optical Clear Adhesive).

[0035] The transparent antenna 100 of this embodiment is provided between the first adhesive layer 281 and the polarizing plate 291. The transparent antenna 100 has a transparent substrate 101 and an antenna pattern 110 formed on the upper surface of the transparent substrate 101. In addition, a periodic structure layer 410 is formed on the lower surface of the transparent substrate 101.

[0036] In this configuration, the electrode layer 301, which is a part of the touch panel 230, is regarded as a background layer of the AMC. With this configuration, in Fig. 4, the artificial magnetic conductor (AMC) 400 is composed of the periodic structure layer 410 and the electrode layer 301 of the touch panel 230, which functions as a background layer, sandwiching the first adhesive layer 281.

[0037] Here, a normal metal conductor reflects electromagnetic waves with the phase reversed by 180 degrees, as shown in Figure 5 A. If such a normal metal conductor is placed close to an antenna, the radiation from the antenna and the waves reflected by the metal will interfere with each other, reducing the strength of the radio waves.

[0038] On the other hand, an artificial magnetic conductor (AMC) is a conductor layer that reflects electromagnetic waves with a phase of approximately 0 degrees (i.e., reflects them in phase) and amplifies the reflected waves near the reflecting surface, as shown in Figure 5B. Therefore, by placing an AMC with a periodic structure layer close to an antenna, it is possible to suppress the adverse effects of metal conductors on the antenna characteristics.

[0039] Moreover, touch panel 230 is a "metallic thin wire layer for an on-cell touch panel." Here, "on-cell" refers to a structure in which an electrode layer is formed directly on the surface of display panel 220, rather than attaching a touch panel formed on a substrate independent of display panel 220. Alternatively, touch panel 230 may be a non-on-cell metallic thin wire (wiring layer) for a touch panel in which a touch panel formed on an independent substrate is bonded to display panel 220.

[0040] The touch panel 230 includes an electrode layer 301 , which serves as a background conductor for the AMC 400 .

[0041] The display panel (display) 220 is, for example, a liquid crystal display panel, an organic EL (Electro-luminescence) display, or an OLED (Organic Light Emitting Diode) display. It is a splay panel, which is located at the bottommost part of the display module 1 in either configuration.

[0042] In the display module 1, the periodic structure layer 410 and the antenna pattern 110 may be provided partially on the transparent substrate 101. The periodic structure layer is provided so as to include at least the antenna portion of the antenna pattern 110 when viewed vertically. The transparent substrate 101 may cover the entire surface of the display when viewed vertically, or may be provided partially. When the transparent substrate covers the entire surface of the display, the thickness can be made uniform, and the occurrence of air lines due to steps can be suppressed.

[0043] In the case where the transparent antenna 100 having the periodic structure layer 410 formed on the lower surface is partially provided, the touch panel 230, the first adhesive layer 281, the polarizing plate 291, and / or the second adhesive layer 282 may be made thinner in the area where the transparent antenna 100 is provided than in other areas. Alternatively, the first adhesive layer 281, the polarizing plate 291, and / or the second adhesive layer 282 may be omitted. It may also be configured in this way. Thereby, in the display module 1, it is possible to prevent only the portion of the transparent antenna 100 from bulging up.

[0044] However, it has been found that if the transparent antenna 100 is too thick, in addition to the overall thickness of the device becoming thick, there are problems such as the edge portion of the transparent antenna being visible and air being likely to be mixed into the boundary with the adhesive layers 281 and 282. The thickness of the transparent antenna 100 is preferably 300 μm or less, more preferably 150 μm or less, and particularly preferably 100 μm or less. Also, from the viewpoint of ease of handling, the thickness of the transparent antenna 100 is preferably 10 μm or more and more preferably 50 μm or more.

[0045] Also, in FIGS. 2 and 3, an example is shown in which both end portions in the +-Y direction of the display module 1 have a gently curved surface shape, but the display module 1 may have a planar shape where the ends do not bend. In that case, the transparent antenna 100 may also have a planar shape. In addition, when the transparent antenna 100 is partially curved, the power feeding region described later has a curved surface shape.

[0046] Here, as a result of intensive studies, the inventors have found that in an artificial magnetic conductor (AMC), the more separated the periodic structure layer and the background conductor are, the better the electrical performance. Also, it has been found that even if the periodic structure layer of the antenna and the AMC is provided in close proximity to the antenna, there is not much adverse effect.

[0047] Therefore, in this configuration, when the distance from the antenna pattern 110 of the transparent antenna 100 to the periodic structure layer 410 of the AMC (artificial magnetic conductor) 400 is h1, and the distance from the periodic structure layer 410 to the background conductor 301 in the AMC 400 is h2, the relationship h1 < h2 is set. In this configuration, h1 corresponds to the thickness of the transparent substrate 101 of the transparent antenna 100. Regarding h2, it will be described later together with FIG. 13.

[0048] In this configuration, the periodic structure layer of the AMC400 is formed on the back surface of the antenna substrate (transparent substrate 101), and the background conductor of the AMC400 is a part (electrode layer 301) of the touch panel 230, which is a metal thin wire layer. In this manner, the electrode layer 301 of the existing touch panel 230 is used as the background conductor of the AMC400, so that the function of the AMC400 can be added to the display module 1 without adding a substrate by simply providing the periodic structure layer 410 under the transparent antenna 100. Therefore, the display module 1 according to this embodiment can avoid an increase in the lamination thickness while containing an artificial magnetic conductor (AMC) that can suppress antenna gain loss.

[0049] (2-2. Configuration of a transparent antenna with a periodic structure layer on the underside) Next, the configuration of the transparent antenna 100 provided with the periodic structure layer 410 according to the first embodiment of the present invention will be described with reference to Figs. 6 to 8. Fig. 6 is a perspective view of the transparent antenna 100 according to the first embodiment of the present invention, the underside of which is provided with a periodic structure layer of AMC. Figs. 7A and 7B are explanatory views of the transparent antenna 100 according to the first embodiment, in which Fig. 7A is a top view seen from the +Z direction and Fig. 7B is a bottom view seen from the -Z direction. Note that even when a part of the transparent antenna 100 is arranged along a curve as in Fig. 2, Fig. 6 shows the transparent antenna 100 in a state parallel to the XY plane before it is folded.

[0050] The transparent antenna 100 has a transparent substrate 101, and an antenna pattern 110 is provided on the transparent substrate 101. The antenna pattern 110 in this configuration is an example of a dipole antenna. Note that in this embodiment, an antenna feed line is not shown, and an ideal antenna unit model that is ideally fed is used.

[0051] The transparent substrate (also referred to as a transparent base material or a transparent substrate) 101 is, for example, a flexible substrate made of polyimide, and is bendable in the Z direction and / or the X direction. The transparent substrate 101 is also colorless and transparent, and is an insulating substrate.

[0052] 6 and 7A, antenna pattern 110 in this configuration is composed of one linear element that passes through the center in the Y direction and extends in the Y direction. In this configuration, antenna pattern 110 is provided on the +Z side, which is the upper surface side of transparent substrate 101.

[0053] Here, the conductor length of the antenna pattern 110 is L110, and the wavelength on the transparent substrate 101 at the resonant frequency f1 (28 GHz) of the transparent antenna 100 is λ 01 As a result, L110 is about 0.5λ. 01 Therefore, when it is desired to improve the antenna gain in the frequency band f1, the conductor length L110 of the line element of the antenna pattern 110 may be adjusted to within ±10% of about 4.0 mm, for example.

[0054] Also, referring to Figures 6 and 7B, a plurality of conductive patterns P1 to P9 are periodically arranged on the lower surface of the transparent substrate 101, and the conductive patterns P1 to P9 thus arranged periodically serve as periodic floating conductors (resonant elements) to form the periodic structure layer 410 of the AMC 400.

[0055] In this embodiment, by forming a multi-layer structure on one substrate (the transparent substrate 101), the periodic structure layer 410 of the AMC 400 and the antenna pattern 110 of the transparent antenna 100 can be formed at the same time.

[0056] (2-3. Structure of transparent conductor) Fig. 8 is an explanatory diagram of a transparent conductor 80 of the present invention. The transparent conductor 80 is formed on the surfaces (upper and lower surfaces) of the transparent substrate 101, and is used, for example, to constitute the antenna pattern 110 and the periodic structure layer 410 shown in Fig. 6, Fig. 7A, and Fig. 7B. The transparent conductor 80 is a conductor with such high optical transparency that it is difficult for the human eye to see it.

[0057] Specifically, the transparent conductor 80 is a layer of conductive lines, i.e., a thin metal wire layer, formed, for example, in a mesh shape to enhance light transparency. As shown in Fig. 8, in the mesh-shaped thin metal wire layer, a plurality of thin metal wires 81 extending in one direction and a plurality of thin metal wires 82 extending in the other direction are arranged to intersect with each other, and openings (through holes) 83, which are mesh-like gaps (openings), are formed.

[0058] When the transparent conductor 80 is formed in a mesh shape, the openings 83 of the mesh may be rectangular or rhombic. When the openings 83 of the mesh are formed in a rectangular shape, the mesh preferably has square openings, which provides good design. The openings 83 of the mesh may also have a random shape formed by a self-organizing method, which can suppress moire. The line widths (wiring widths) w81 and w82 of the thin metal wires 81 and 82 constituting the mesh are preferably 1 to 10 μm, more preferably 1 to 5 μm, and even more preferably 1 to 3 μm. The line spacings (also called mesh openings or wiring pitches) p81 and p82 between the thin metal wires 81 and between the thin metal wires 82 of the mesh are preferably 300 to 500 μm.

[0059] The aperture ratio, which is the ratio of the area of ​​the openings 83 to the entire mesh in the transparent conductor 80, is preferably 80% or more, and more preferably 90% or more. The larger the aperture ratio of the transparent conductor 80, the higher the visible light transmittance of the transparent conductor 80 can be.

[0060] The sheet resistance of the transparent conductor is preferably 5 Ω / sq or less, more preferably 3 Ω / sq, and even more preferably 1 Ω / sq.

[0061] When the transparent conductor 80 is formed in a mesh shape, the thickness of the transparent conductor 80 may be 1 to 40 μm. By forming the transparent conductor 80 in a mesh shape, the visible light transmittance can be increased even if the transparent conductor 80 is thick. The thickness of the transparent conductor 80 is more preferably 5 μm or more, and even more preferably 8 μm or more. Moreover, the thickness of the transparent conductor 80 is more preferably 30 μm or less, even more preferably 20 μm or less, and particularly preferably 15 μm or less.

[0062] In the transparent conductor 80, the conductor thickness t is set smaller than the line widths (conductor widths) w81, w82 of the mesh-like thin lines. This is because if the aspect ratio exceeds 1, the structure will be unbalanced, prone to breakage, and difficult to manufacture. However, the thicker the conductor thickness t, the smaller the sheet resistance value can be, and therefore a larger conductor thickness t is better for antenna efficiency, so it is preferable that t is smaller than w and as large as possible.

[0063] The conductive material of the thin metal wires 81, 82 of the transparent conductor 80 can be copper, but other metal materials such as gold, silver, platinum, aluminum, chromium, tin, iron, and nickel can also be used, and the material is not limited to these.

[0064] The antenna pattern 110 and the periodic structure layer 410 realized by such a transparent conductor 80 are transparent, have such high light transmittance that they are difficult to see with human eyesight, and can function as a conductor.

[0065] (2-4. AMC configuration example) As mentioned above, an artificial magnetic conductor (AMC) is a conductor that reflects electromagnetic waves with a phase of approximately 0 degrees and amplifies the reflected waves near the reflecting surface.

[0066] AMCs with such characteristics can be roughly divided into two types, as shown in Figures 9A and 9B. Figures 9A and 9B are explanatory diagrams of two general types of AMCs. Figure 9A shows an example of a vertically conductive AMC, and Figure 9B shows an example of a vertically non-conductive AMC.

[0067] (1) As shown in Fig. 9A, in the vertically conductive AMC, a lower background conductor (ground plate) 46 and an upper floating conductor 47 of a periodic structure layer 45 are vertically connected through vias 49. The multiple floating conductors 47 are separated by slits 48. This type of structure is also called a mushroom type. (2) The top-bottom non-conductive AMC, as shown in Fig. 9B, is composed of a background conductor (ground plane) 42 and a periodic structure layer 41 that is not connected to the background conductor. The periodic structure layer 41 has multiple floating conductors 43 separated by slits 44.

[0068] The periodic structure layer is a spatial filter that selectively reflects a specific frequency and is called an FSR (Frequency Selective Reflector), an FSS (Frequency Selective Surface), an EBG (Electromagnetic Band Gap), or a metasurface.

[0069] In the case of the configuration (1), since the upper and lower layers are connected through vias, the periodic structure layer and the background conductor must be formed on the upper and lower surfaces of the same substrate, as shown in Fig. 9 A. In contrast, in the case of the configuration (2), since the periodic structure layer 41 and the background conductor 42 are not connected, they may be formed on different substrates.

[0070] In the present invention, the top-bottom non-conductive AMC of (2) is applied, and further, a configuration in which the functions of the periodic structure layer 41 of the AMC and the background conductor 42 are realized by separate substrates will be described.

[0071] The above-mentioned (2) AMC with vertical non-conductivity has two main types of periodic structure layers. Figures 10A and 10B are explanatory diagrams of AMCs with vertical non-conductivity, where Figure 10A shows an AMC with a patch-type periodic structure and Figure 10B shows an AMC with a hole-type periodic structure.

[0072] In the patch-type periodic structure layer on the upper layer of the AMC shown in Fig. 10A, metal (resonant element) patches of the same shape are periodically arranged. The periodic structure layer 410 provided on the lower surface of the transparent antenna 100 shown in Fig. 6 is also an example of a patch-type periodic structure layer. In the AMC having the periodic structure of the patch-type FSR, when the resonant element completely resonates, the reflection coefficient becomes -1, and the AMC functions as a band-stop filter.

[0073] In the hole-type periodic structure layer on the AMC shown in Fig. 10B, holes (resonant elements) of the same shape are periodically formed in a metal layer. When the resonant elements of the AMC with the periodic structure of the hole-type FSR completely resonate, the transmission coefficient becomes 1, and the AMC functions as a band-pass filter.

[0074] In Figures 6 and 7B and the simulation example described below, examples are shown in which the periodic structure layer 410 of the AMC has a patch-type configuration, but the periodic structure layer in the AMC of the present invention may also be a hole-type periodic structure layer, as shown in Figure 10B.

[0075] In the periodic structure layer, the multiple patches in FIG. 10A and the multiple holes in FIG. 10B serve as resonant elements.

[0076] FIG. 7B shows an example in which the resonant element is square, and FIGS. 10A and 10B show examples in which the resonant element is circular, but the configuration of the patch portion of the patch-type FSR or the hole portion of the hole-type FSR may be other shapes.

[0077] Fig. 11 is a diagram showing a modified example of the resonant element in the periodic structure layer of the AMC of the present invention. For example, the resonant element can be in the shape of a square loop, a ring, a double square loop, a cross shape, a cross shape with arms, a rectangular loop with a capacitor, a rectangular dipole, a tripole, a three-legged dipole, a four-legged dipole, a heart shape, etc., as shown in Fig. 11. Note that the example in Fig. 11 is just one example, and the resonant element in the periodic structure layer may have another shape, such as the floating conductor 43 shown in Fig. 9B.

[0078] (2-5. Touch panel configuration) Next, the configuration of the touch panel 230 in the first embodiment, part of which also serves as a background conductor of the AMC 400, will be described with reference to Figs. 12 and 13. As an example of the touch panel 230, the configuration of a sensor pattern in a projected capacitive touch panel (also called a touch sensor) will be described below. Fig. 12 is a schematic diagram of a sensor pattern of a general projected capacitive touch panel 230.

[0079] Referring to FIG. 12, the touch panel 230 has a plurality of first electrodes 31 and a plurality of second electrodes 32 provided on a substrate, and has a plurality of first wirings 38 connecting to the plurality of first electrodes 31 and a plurality of second wirings 39 connecting to the plurality of second electrodes 32.

[0080] As shown in Fig. 12, in the sensor pattern of the projected capacitive touch panel 230, multiple electrodes 31, 32 are arranged in a matrix, and adjacent electrodes are capacitively coupled to each other. When a conductive material such as a finger approaches an electrode, capacitive coupling occurs between the finger and the electrode, and the part where the capacitive coupling value between the electrodes changes is detected as the touch position. With such a projected capacitive touch panel, multiple positions on the touch panel 230 can be detected simultaneously.

[0081] In the touch panel 230, the first electrode 31 and the second electrode 32 may be provided on different surfaces or different layers, or may be provided on the same surface. Specific examples are shown below. For example, (1) A first electrode 31 is provided on one surface of one glass substrate, and a second electrode 32 is provided on the other surface. (2) In a structure in which two layers of glass (printed circuit boards) are stacked, a first electrode 31 is provided on the upper glass substrate, and a second electrode 32 is provided on the lower glass substrate. (3) A first electrode 31 is provided on one surface of one film, and a second electrode 32 is provided on the other surface. (4) In a structure in which two films are stacked, a first electrode 31 is provided on the upper film and a second electrode 32 is provided on the lower film. (5) The diamond-shaped electrode portions of the first electrode 31 are provided on the same plane as the second electrode 32, and the diamond-shaped electrodes are connected by bridge electrodes provided on different layers. (1) to (4) are cases where they are provided on different surfaces or in different layers, and (5) is a case where they are provided in the same layer.

[0082] 12, the first electrodes 31 are connected in a skewer shape in the horizontal direction (X direction), and the second electrodes 32 are connected in a skewer shape in the vertical direction (Y direction). The outlines of the first electrodes 31 and the second electrodes 32 are defined by a common first straight line L1 and a second straight line perpendicular to the first straight line. The shape is a diamond or square formed by

[0083] In the first electrode 31 and the second electrode 32, whose four sides are formed using a plurality of parallel straight lines L1 and a plurality of parallel straight lines L2, adjacent sides are spaced apart by a distance d.

[0084] The smaller the distance d, the less visible the gap between the electrodes, which is preferable, but if the distance d is too wide, areas where the electrodes 31 and 32 are not present may be visible. However, the smaller the distance d, the more difficult it is to adjust the positions between different layers, and the more complicated the manufacturing process becomes. The size of the gap d may be, for example, greater than 0 and less than 10 mm, preferably greater than 1 μm and less than 5 mm, more preferably greater than 3 μm and less than 1 mm, and more preferably greater than 5 μm and less than 500 μm.

[0085] Fig. 13 is an example of a cross-sectional view of a touch panel 230. Fig. 13 shows a configuration example in which the diamond-shaped electrode portion of the first electrode 31 is provided in the same plane as the second electrode 32 described above (5), and the diamond-shaped electrodes are connected by bridge electrodes provided in different layers.

[0086] In the example of FIG. 13, the touch panel 230 has an electrode layer 301, an insulating layer 302, a bridge layer 303, and an insulating protection layer 304. The electrode layer 301 is partitioned by insulating holes 306 to form electrodes 31 and 32. In this example, the insulating holes 306 that separate the electrodes 31 and 32 correspond to the slits S1 and S2. The insulating holes 306 and the insulating protection layer 304 are integrally formed.

[0087] Through holes 305 that penetrate vertically are formed in the insulating layer 302, and the electrode layer 301 and the bridge layer 303 are electrically conductive through the through holes 305. The bridge layer 303 and the through holes 305 function as jumpers 35.

[0088] The electrode layer 301, the bridge layer 303, and the through holes 305 are composed of, for example, metals such as Ti and Al. The insulating layer 302 is composed of, for example, SiNx. The insulating protection layer 304 and the insulating holes 306 do not have conductors and are composed of, for example, acrylic.

[0089] As described above, in the first embodiment, the electrode layer 301 of the touch panel 230 functions as the background conductor of the AMC400. Therefore, the distance h2 from the periodic structure layer 410 of the AMC400 to the background conductor in FIG. 4 is exactly the sum of the first adhesive layer 281 and the thickness of the insulating protection layer 304 above the electrode layer 301 in the touch panel 230.

[0090] Therefore, in FIG. 4, to achieve h1 < h2, the sum of the thickness of the first adhesive layer 281 and the insulating protection layer 304 of the touch panel 230 may be made thicker than the thickness of the transparent substrate 101 of the transparent antenna 100.

[0091] h2 is preferably 100 μm or more, more preferably 150 μm or more, and even more preferably 300 μm or more. By setting it in this way, it is possible to obtain a function of effectively reflecting electromagnetic waves. Moreover, h2 is preferably 2000 μm or less, more preferably 1000 μm or less, and even more preferably 600 μm or less. By doing so, it is possible to maintain the characteristics while suppressing a significant increase in the lamination thickness.

[0092] h1 is preferably 5 μm or more, more preferably 15 μm or more, and even more preferably 50 μm or more. By setting it in this way, it is possible to prevent an increase in the laminate thickness while maintaining the function of reflecting electromagnetic waves. Moreover, h1 is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 100 μm or less.

[0093] <Simulation example> (3-1. Measurement model configuration and characteristics of pseudo-AMC minimum unit 1) In order to confirm the behavior of the AMC, the inventors of the present application performed various simulations on a pseudo-AMC that imitates the AMC of the present application.

[0094] Fig. 14 is a schematic diagram of a pseudo-AMC consisting of one floating conductor, an adhesive layer, and a metal conductor simulating a touch panel. In the measurement model 61 of the pseudo-AMC shown in Fig. 14, a floating conductor P, which is smaller than the adhesive layer and serves as a repeating unit of the periodic structure layer, is provided on the adhesive layer 281, and a metal conductor M is provided under the adhesive layer 281. This metal conductor M functions as a background conductor of the AMC.

[0095] In this simulation, the parameters of the reflection amplitude and reflection phase were measured while changing the resistance value of the metal conductor M, which is the resistor in the bottom layer. The dimensions of each part of the pseudo AMC shown in Figure 14 when measuring these parameters are as follows: One side of floating conductor P: 3 mm Adhesive layer 281, one side of metal conductor M: 4.7 mm It is.

[0096] In addition, the thickness of each layer in the pseudo-AMC is Thickness of floating conductor P: 1 μm Thickness of adhesive layer 281: 150 μm It is. Since the surface impedance for which the surface resistance is set is set as the boundary condition, the metal conductor M is set to have no thickness.

[0097] Figures 15A and 15B show characteristic values ​​of reflection amplitude parameters when the resistance value of the metal conductor M is changed in the pseudo-AMC of Figure 14. Figures 16A and 16B show characteristic values ​​of reflection phase parameters when the resistance value of the metal conductor M is changed in the pseudo-AMC of Figure 14.

[0098] In this measurement, in the pseudo-AMC shown in FIG. 14, the resistance value (sheet resistance value) of the metal conductor M was changed in 23 steps, namely, 0.00001, 0.1, 0.2, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.1, 2.4, 2.8, 3.2, 3.7, 4.2, 4.9, 5.6, 6.4, 7.4, 8.4, 9.7, and 10 Ω / sq. The parameters of the reflection amplitude and phase were calculated.

[0099] In order to explain the tendency of change in the measured parameters, Figs. 15A and 16A show the case where the resistance value of the metal conductor M is 0 to 2.4 Ω / sq, and Figs. 15B and 16B show the case where the resistance value of the metal conductor M is 0 to 2.4 Ω / sq. This shows the case where the resistance is 2.8 to 10 Ω / sq.

[0100] As shown in Fig. 15A, when the resistance value of the metal conductor M is 0 to 2.4 Ω / sq, the absolute value of the pole value of the reflection amplitude increases as the resistance value increases at 29 GHz. On the other hand, as shown in Fig. 15B, when the resistance value of the metal conductor M is 2.8 to 10 Ω / sq, the resistance value increases at 29 GHz. Indeed, the absolute value of the pole value of the reflection amplitude becomes smaller. Note that the part with a downward convex pole is the part where the electromagnetic wave is absorbed by the AMC, and the smaller the value (the larger the absolute value), the greater the amount of absorption.

[0101] When the resistance value of the metal conductor M shown in FIG. 16A is 0 to 2.4 Ω / sq, the reflection phase passes through phase 0 with a certain gradient at 29 GHz. These waveforms are similar to the waveforms seen in the reflection phase of so-called general AMCs, and such waveforms can be used as AMCs when the reflection phase is in the range of -90° to 0° to 90°. That is, within this resistance range, Therefore, it can be said that the pseudo-AMC measurement model 61 in FIG. 14 functions as an AMC.

[0102] In contrast, when the resistance value of the metal conductor M shown in Fig. 16B is 2.8 to 10 Ω / sq, the phase suddenly switches from positive to negative at the point where the phase passes through 0 in response to the change in frequency, and the reflection phase changes significantly and instantaneously. If the phase changes from 0 in this way instantaneously, it will not function as an AMC.

[0103] Therefore, the floating conductor P and the metal conductor M are connected by the adhesive layer 281 that transmits electromagnetic waves. When the metal conductors are spaced apart by 1 μm, the metal conductor M must be less than 2.8 Ω / sq to be considered an AMC. All of these functions can be realized.

[0104] 15A and 15B and Fig. 16A and 16B, the phase is zero in Fig. 16A and 16B at the frequency where the downward convex pole appears in Fig. 15A and 15B. As described above, the smaller the value (the larger the absolute value) of the downward convex part in Fig. 15A and 15B, the more the electromagnetic wave is absorbed by the AMC, resulting in a loss of the electromagnetic wave, and therefore, from Fig. 15A, it is preferable that the metal conductor M has a resistance value as close to 0 as possible within a range of less than 2.8 Ω / sq, more preferably less than 2.4 Ω / sq.

[0105] In addition, since the influence of the metal conductor M decreases as the distance between the floating conductor P and the metal conductor M increases, the resistance value of the metal conductor M can be appropriately set according to the distance between the floating conductor P and the metal conductor M. For example, when the distance between the floating conductor P and the metal conductor M is greater than 0.15 mm as shown in Fig. 14, the resistance value of the metal conductor functioning as an AMC becomes 2.8 Ω / sq or more, and when the distance between the floating conductor P and the metal conductor M is smaller, the resistance value of the metal conductor functioning as an AMC becomes smaller than 2.8 Ω / sq.

[0106] For example, when the distance between the floating conductor P and the metal conductor M is 0.30 mm, the resistance value of the metal conductor M functioning as an AMC is preferably less than 5.6 Ω / sq, and more preferably 5.0 Ω / sq or less.

[0107] 4 is 0.15 mm, the sheet resistance of the electrode layer 301 of the touch panel 230 is preferably less than 2.8 Ω / sq in order to allow the electrode layer 301 to function as a background conductor of the AMC 400. In addition, when h2 is 0.30 mm, the sheet resistance of the electrode layer 301 functioning as a background conductor of the AMC is preferably less than 5.6 Ω / sq, more preferably 5.0 Ω / sq or less.

[0108] In this example, the electrode layer 301 in the touch panel 230 is a member having a small sheet resistance value and functions as a background conductor, but the sheet resistance value may be adjusted by modifying the wiring pattern of the electrode layer 301 of the touch panel from an existing one. Specifically, a touch panel having a low sheet resistance value may be configured by adjusting the length of the slits in the thin line pattern of the electrode layer 301, the length of the contour side of the electrode, and the presence or absence of a jumper, as described in paragraphs

[0082] to

[0106] of Japanese Patent Application No. 2020-078661.

[0109] Alternatively, the insulating protective layer 304 on the electrode layer 301 of the touch panel 230 may be made of a resin material having a dielectric constant different from that of acrylic, such as a material containing polycarbonate resin or fluororesin, instead of general insulating materials such as glass, film, acrylic, etc. This can reduce the sheet resistance of the touch panel.

[0110] Furthermore, the conductor thickness of electrode layer 301 of touch panel 230 may be increased, thereby making it possible to reduce the sheet resistance value of touch panel 230.

[0111] (3-2. Measurement model configuration and characteristics of pseudo-AMC minimum unit 2) Fig. 17 is a schematic diagram of a pseudo-AMC consisting of one floating conductor, an adhesive layer, and a metal conductor simulating a touch panel. In the measurement model 62 of the pseudo-AMC shown in Fig. 17, similar to Fig. 14, a floating conductor P that is smaller than the adhesive layer and serves as a repeating unit of the periodic structure layer is provided on the adhesive layer 281, and a metal conductor M is provided under the adhesive layer 281. This metal conductor M functions as a background conductor of the AMC.

[0112] In this simulation, the parameters of reflection amplitude and reflection phase were measured while changing the size of the floating conductor P of the top layer as shown by the dotted line in Fig. 17. The dimensions of each part of the pseudo-AMC shown in Fig. 17 when measuring these parameters are the same as those in Fig. 14, except for the size of the floating conductor P. In this simulation, the resistance value of the metal conductor M of the bottom layer was fixed at 1.0 Ω / sq.

[0113] Fig. 18 shows characteristic values ​​of the reflection amplitude parameters when the size of the floating conductor P is changed in the pseudo-AMC of Fig. 17. Fig. 19 shows characteristic values ​​of the reflection phase parameters when the size of the floating conductor P is changed in the pseudo-AMC of Fig. 17.

[0114] In this measurement, in the pseudo AMC shown in Figure 17, the size of one side of the square floating conductor P was changed to five steps of 2.0, 2.5, 2.7, 3.0, and 3.5 mm, and the reflection amplitude and reflection phase were measured for each step. The parameters were calculated.

[0115] 18, when the size of the floating conductor P is changed, the frequency at which the pole appears in the reflection amplitude changes. The frequency band at which the downward convex pole appears is higher as the floating conductor P is smaller, and is lower as the floating conductor P is larger.

[0116] 19, changing the size of the floating conductor P changes the frequency of the reflected phase that passes through phase 0. The band where phase 0 occurs has a higher frequency as the floating conductor P is smaller, and a lower frequency as the floating conductor P is larger.

[0117] In order to support the 29 GHz used in 5G communications, the 5G 18 is close to the pole and the 5G 19 is close to the pole. Of the structures measured, a floating conductor measuring 3 x 3 mm is the most suitable for returning electromagnetic waves with a phase of zero +-90°.

[0118] As shown in Figures 15A, 15B, 16A, and 16B above, the frequency band where the pole of the reflection amplitude and the reflection phase become 0 do not change even if the resistance value of the metal conductor changes. Therefore, when a square patch-type floating conductor is provided in the periodic structure of the AMC of the present invention, in order to accommodate 29 GHz used in 5G communications, it is preferable to set the size of the floating conductor to around 3 x 3 mm (for example, one side is about 2.8 to 3.4 mm).

[0119] (3-3. Measurement model configuration and characteristics of antenna alone, pseudo display module with AMC, and pseudo display module for comparison) The inventors conducted a comparative experiment of the performance of a single antenna, a pseudo display module in which a floating conductor of the size selected in Simulation Example 2 is formed as a periodic structure layer, and a measurement model in which no floating conductor is provided.

[0120] 20 is a schematic diagram of a measurement model 63 composed of the transparent antenna 100 of the present invention and an adhesive layer 281. This measurement model 63 has a transparent antenna 100 without a floating conductor, and an adhesive layer 281. Since the adhesive layer 281 transmits electromagnetic waves, the antenna characteristics of this measurement model 63 are considered to be almost equivalent to those of the antenna alone.

[0121] When this parameter was measured, the dimensions of each part of the measurement model 63 shown in FIG. 20 were as follows: L110: 4.0mm W110: 0.2mm One side of the substrate 101 and adhesive layer 281: 20 mm

[0122] In addition, the thickness of each layer in the measurement model 63 is Thickness of antenna pattern 110: 1 μm Thickness of transparent substrate 101: 75 μm Thickness of adhesive layer 281: 150 μm It is.

[0123] 21 is a schematic diagram of a pseudo display module consisting of a transparent antenna of the present invention, a periodic structure layer 41 formed on the lower surface of the transparent antenna, an adhesive layer 281, and a metal conductor simulating a touch panel. In this measurement model 64, a periodic structure layer 410, which is a plurality of periodic floating conductors, is provided on the lower surface of a transparent substrate 101, and a metal conductor M is provided under the adhesive layer 281 below the transparent conductor. The resistance value of the metal conductor M in the bottom layer is fixed at 1.0 Ω / sq.

[0124] In the dimensions of each part of the pseudo display module shown in FIG. 21 when this parameter was measured, the antenna pattern 110 is the same as in FIG. 20, and the other dimensions are as follows: One side of the substrate 101 and adhesive layer 281: 20 mm Floating conductor side: 3mm Distance between adjacent floating conductors: 1.7mm

[0125] In addition, the thickness of each layer in the measurement model 64 is Thickness of antenna pattern 110: 1 μm Thickness of transparent substrate 101: 75 μm Thickness of the periodic structure layer 410: 1 μm Thickness of adhesive layer 281: 150 μm It is. That is, h1 is 75 μm and h2 is 150 μm. Since the surface impedance for which the surface resistance is set is set as the boundary condition, the metal conductor M is set to have no thickness.

[0126] Fig. 22 is a schematic diagram of a measurement model of a pseudo display module according to a comparative example, which is composed of a transparent antenna, an adhesive layer, and a metal conductor simulating a touch panel. This measurement model 65 differs from Fig. 21 in that the periodic structure layer shown in Fig. 21 is not provided on the lower surface of the transparent substrate 101 of the transparent antenna 100, but the other configurations are the same as those in Fig. 21.

[0127] FIG. 23 is a table showing the maximum gains for the measurement models of FIGS. 20, 21, and 22.

[0128] Comparing the maximum gains in the table of Figure 23, the maximum gain for the antenna alone in Figure 20 was +1.9 dB, but when a metal conductor is provided under the adhesive layer as in Figure 22, the maximum gain drops significantly to -5.3 dB. In contrast, when a periodic structure layer is provided as in Figure 21 in addition to the structure in Figure 22, the maximum gain becomes -3.1 dB, and the drop in gain from the structure in Figure 21 is smaller.

[0129] Therefore, it can be seen that the maximum gain is improved and the performance of the antenna is improved when the periodic structure layer is provided, compared to when a single metal conductor is provided.

[0130] In this simulation example, an example was described in which the frequency used for transmission and reception was 29 GHz (24.2 to 29.5 GHz), but the transparent antenna 100 included in the display module of the present invention may be an antenna compatible with other frequency bands used in 5G, such as 37.3 to 40 GHz or 1.0 to 5.0 GHz. When the frequency used by the antenna changes in this way, it is preferable to design the AMC to have a structure suitable for that frequency band by changing the size of the patch, which is the floating conductor of the periodic structure layer 410 of the AMC 400, as shown in FIG.

[0131] In this simulation example, the frequency band used for transmission and reception is 29 GHz. However, the transparent antenna 100 included in the display module of the present invention may be configured to support dual bands, enabling transmission and reception in other frequency bands used in 5G. In that case, it is preferable to appropriately set the shape of the floating conductor of the periodic structure layer so that the AMC also reflects in multiple bands used in the dual band.

[0132] (4. Display module 1A according to a modification of the first embodiment of the present invention) Fig. 24 shows a display module 1A according to a modification of the first embodiment. Fig. 4 illustrates an example in which only a first adhesive layer 381 is provided between the periodic structure layer constituting the AMC and the electrode layer 301 of the touch panel 230, which is a background conductor, but in this modification, as shown in Fig. 24, a first adhesive layer 281 and a polarizing plate 292 are provided between the periodic structure layer and the background conductor.

[0133] That is, in the configuration shown in Figure 24, an artificial magnetic conductor (AMC) 400α is formed by a periodic structure layer 410 sandwiched between a polarizing plate 292 and a first adhesive layer 281, and an electrode layer 301 of the touch panel 230 that functions as a background conductor.

[0134] Also in this configuration, the periodic structure layer 410 of the AMC400α is formed on the lower surface of the antenna substrate (transparent substrate 101), and the background conductor of the AMC400α is the electrode layer 301 of the touch panel of the metal fine wire layer. And in this configuration, the polarizing plate sandwiched between the periodic structure layer and the background conductor of the AMC generally allows electromagnetic waves to pass through, so it can be considered that it does not affect the characteristics of the AMC or the antenna.

[0135] Also in this configuration, when the distance from the antenna pattern 110 of the transparent antenna 100 to the periodic structure layer 410 of the AMC400α is h1, and the distance from the periodic structure layer 410 to the background conductor in the AMC400α is h2α, there is a relationship of h1 < h2α. In FIG. 24, since h2α is the sum of the thickness of the polarizing plate 292, the thickness of the first adhesive layer 281, and the thickness of the insulating protection layer 304 of the touch panel, by making this total thickness thicker than the transparent substrate 101 of the transparent antenna 100, the above relationship of h1 < h2α is realized.

[0136] In the configuration according to FIG. 24, an additional substrate is not required. As a result, the performance of the antenna can be improved without increasing the stacking thickness of the display module 1A compared to the case where only the touch panel which is a metal plate is provided.

[0137] Furthermore, in this modification, since the polarizing plate 292 can also be used as the thickness of h2α that constitutes the AMC400α, even if the polarizing plate 292 and the adhesive layer 281 are thinner than in FIG. 4 without providing the polarizing plate on the antenna, the relationship of h1 > h2α can be established. Therefore, the thickness of the display module 1A can be further suppressed.

[0138] (5-1. Display Module 2 According to the Second Embodiment of the Present Invention) FIG. 25 shows a display module 2 according to the second embodiment of the present invention. In this embodiment, the periodic structure layer 410 of the AMC is formed on the back surface of the antenna substrate as described above, but the background conductor of the AMC is constituted by a part of the display panel 220.

[0139] In the configuration shown in Figure 25, an artificial magnetic conductor (AMC) 400β is formed by a periodic structure layer 410 sandwiched between a first adhesive layer 281 and a transparent electrode (cathode) 26 of the display panel 220 that functions as a background conductor.

[0140] (5-2. Display panel configuration explanation) Fig. 26 is a schematic diagram of an OLED display panel 220, which is an example of a common display panel. In Fig. 26, the upper diagram is a cross-sectional view, and the lower diagram is a plan view (top view).

[0141] 26, an OLED display panel 220 includes a substrate 21, a backplane 22, a lower reflective electrode 23, an aperture insulating film 24, light-emitting layers 25R, 25G, and 25B, and a transparent electrode 26. The substrate 21 is, for example, glass, and the backplane 22 is a TFT (Thin Film Transistor).

[0142] 25R, 25G, and 25B are laminated thin films including a light-emitting layer, and the lower reflective electrode 23, the aperture insulating film 24, the laminated thin films 25R, 25G, and 25B including the light-emitting layer, and the transparent electrode 26 form OLED elements (organic light-emitting diodes) 27R, 27G, and 27B of each color, red, green, and blue.

[0143] The uppermost transparent electrode 26 is made of a metal such as Al or an alloy of Mg and Ag, thin enough to transmit light, or made of a metal oxide such as ITO.

[0144] In this configuration, the portion of the topmost transparent electrode 26 of the display panel 220 acts as a background conductor underneath the AMC 400 .

[0145] Therefore, in the present configuration shown in FIG. 26, when the thickness of the transparent substrate 101, which is the distance from the antenna pattern 110 of the transparent antenna to the periodic structure layer 410 of the AMC400, is h1, and the distance from the periodic structure layer 410 to the transparent electrode 26 of the display panel 220, which is the background conductor, in the AMC400β is h2β, there is a relationship of h1 > h2β.

[0146] As shown in FIG. 26, since the transparent electrode 26 is the uppermost layer of the display panel 220, and since the h2β in FIG. 25 is the thickness of the first adhesive layer 281, by making the thickness of this first adhesive layer 281 thicker than the transparent substrate 101 of the transparent antenna 100, the above relationship of h1 < h2β can be realized.

[0147] Also, referring to the graphs of FIGS. 14 to 16B described above, when h2β in FIG. 25 is 0.15 mm, in order to make the transparent electrode 26 of the display panel 220 function as the background conductor of the AMC400, the sheet resistance value of the transparent electrode 26 is preferably less than 2.8 Ω / sq. Further, when h2β is 0.30 mm, the sheet resistance value of the transparent electrode 26 functioning as the AMC is preferably less than 5.6 Ω / sq, more preferably 5.0 Ω / sq or less.

[0148] In this example, an example has been described in which the transparent electrode 26 on the display surface in the display panel 220 functions as a background conductor having a small sheet resistance value. However, as a part of the components of the display panel 220, a member (for example, a pattern electrode) for a dedicated background conductor may be further provided on the transparent electrode 26. Specifically, the pattern electrode of the display panel described in paragraphs

[0124] to

[0127] of Japanese Patent Application No. 2020-078661 may be used as the background conductor of the AMC.

[0149] Even when a pattern electrode is provided on the transparent electrode 26 to achieve a low sheet resistance value in the display panel 220, the pattern electrode is located in the uppermost layer of the display panel 220, and therefore the distance h2β that realizes the above-mentioned relationship h1>h2β shown in FIG. 25 becomes the thickness of the first adhesive layer 281.

[0150] In this configuration example, a periodic structure layer 410 is formed of a transparent conductor on the lower surface side of the antenna substrate (transparent substrate 101), and a part of the display panel 220 is used as a background conductor for the AMC, eliminating the need for an additional substrate. This makes it possible to improve the performance of the antenna compared to the case where only a touch panel, which is a metal plate, is provided, without increasing the laminate thickness of the display module 2.

[0151] (5-3. Display module 2A according to a modification of the second embodiment of the present invention) Fig. 27 shows a display module 2A according to a modification of the second embodiment. In Fig. 25, an example in which only an adhesive layer is provided between the periodic structure layer of the AMC and the background conductor has been described, but in this modification, as shown in Fig. 26, an adhesive layer 281 and a polarizing plate 292 are provided between the periodic structure layer and the background conductor.

[0152] In the configuration shown in Figure 27, an artificial magnetic conductor (AMC) 400γ is formed by a periodic structure layer 410 sandwiched between a polarizing plate 292 and a first adhesive layer 281, and a transparent electrode (cathode) 26 of the display panel 220 that functions as a background conductor.

[0153] In this configuration, when the distance from the antenna pattern of the transparent antenna to the periodic structure layer 410 of the AMC is h1 and the distance from the periodic structure layer 410 to the background conductor 26 in the AMC is h2γ, the relationship of h1>h2γ holds. In Fig. 27, h2γ is the sum of the thickness of the polarizing plate 292 and the thickness of the first adhesive layer 281, and therefore, by making this total thickness thicker than the transparent substrate 101 of the transparent antenna 100, the above-mentioned relationship of h1>h2γ is realized.

[0154] This modification also eliminates the need for an additional substrate, and as a result, the performance of the antenna can be improved compared to the case where only a metal touch panel is provided, without increasing the laminate thickness of the display module 2A.

[0155] Furthermore, in this modification, the polarizing plate 292 can also be used as the thickness of h2γ constituting the AMC400γ, so that the relationship h1>h2γ can be established without providing a polarizing plate on the antenna, even if the polarizing plate 292 and the adhesive layer 281 are thinner than those in Fig. 26. This makes it possible to further reduce the thickness of the display module 2A.

[0156] (6-1. Display module 3 according to the third embodiment of the present invention) 28 is an exploded cross-sectional view showing a display module 3 according to a third embodiment of the present invention. In this configuration, the periodic structure layer of the AMC is provided on the back surface of the antenna substrate (transparent substrate 101), while the background conductor is provided on a substrate 401 for AMC, which is a dedicated substrate provided above the touch panel, separately from the touch panel 230. In addition, a third adhesive layer (OCA) 283 is provided between the touch panel 230 and the substrate 401 for AMC in order to laminate the substrates in close contact with each other.

[0157] In this configuration, AMC substrate 401, which is a dedicated substrate for the background conductor of AMC 400δ, is provided above touch panel 230. AMC substrate 401 is a second transparent substrate, and is, for example, a flexible substrate made of polyimide, and is a colorless and transparent insulating substrate that can be bent in the Z direction and / or the X direction.

[0158] In addition, in order for the substrate 401 for AMC to function as the background conductor of the AMC 400δ, a background conductor 420 formed of a mesh-like thin transparent conductor 80 as shown in FIG. 8 is formed over the entire back surface of the substrate. Since the substrate 401 for AMC and the transparent conductor 80 forming the background conductor 420 are transparent, they do not have an adverse effect on the visibility of the display panel 220 below the touch panel 230.

[0159] In the configuration shown in FIG. 28, an artificial magnetic conductor (AMC) 400δ is constituted by a periodic structure layer 410 sandwiching a first adhesive layer 281 and a background conductor 420 provided on the substrate 401 for AMC.

[0160] In this configuration, when the distance from the antenna pattern 110 of the transparent antenna 100 to the periodic structure layer 410 of the AMC 400δ is h1, and the distance from the periodic structure layer 410 to the background conductor 420 in the AMC 400δ is h2δ, they are in the relationship of h1 < h2δ. In FIG. 28, since h2δ is the sum of the thickness of the first adhesive layer 281 and the thickness of the substrate 401 for AMC, by making this total thickness thicker than the transparent substrate 101 of the transparent antenna 100, the above relationship of h1 < h2δ can be realized.

[0161] In this configuration, as described above, since the substrate 401 for AMC, which is a dedicated substrate functioning as the background conductor of the AMC, is provided separately from the touch panel 230, the substrate 401 for AMC can be freely designed independently of the performance of the touch panel 230, such as reducing the sheet resistance value of the background conductor 420 in the substrate 401 for AMC.

[0162] Also, compared with the configuration of the conventional example shown in FIG. 1, the AMC 400δ of this configuration has a periodic structure layer and a background conductor, so it has good performance as a magnetic wall. Furthermore, since the substrate 401 for AMC is formed on a substrate different from the periodic structure layer 410 via the adhesive layer 281, the distance between the background conductor and the periodic structure layer can be increased, and the performance of the AMC can be improved.

[0163] (6-2. Display module 3A according to modification 1 of the third embodiment of the present invention) Fig. 29 is an exploded cross-sectional view showing a display module 3A according to Modification 1 of the third embodiment of the present invention. Fig. 28 describes an example in which a dedicated substrate for the background of the AMC is provided on a touch panel, but the configuration of the AMC having a dedicated background substrate as in this embodiment can also be applied to a display module that does not have a touch panel, as shown in Fig. 29.

[0164] In this modified example, similar to the configuration of Figure 28, an artificial magnetic conductor (AMC) 400δ is composed of a periodic structure layer 410 sandwiching a first adhesive layer 281 therebetween and a background conductor 420 provided on an AMC substrate 401.

[0165] The configuration in Fig. 29 is almost the same as that in Fig. 28 including the configuration of AMC400δ, except that it does not have a touch panel. In this configuration, an AMC substrate, which is a dedicated substrate that functions as a background conductor of the AMC, is provided separately from the display panel 220. Therefore, the AMC substrate 401 can be freely designed independently of the performance of the display panel 220, for example by lowering the sheet resistance value of the background conductor in the AMC substrate 401.

[0166] (6-3. Display module 3B according to modification 2 of the third embodiment of the present invention) Fig. 30 is an exploded cross-sectional view showing a display module 3B according to Modification 2 of the third embodiment of the present invention. While Fig. 28 describes an example in which only an adhesive layer is provided between the periodic structure layer and the AMC substrate, which constitute the AMC, in this modification, as shown in Fig. 30, an adhesive layer 282 and a polarizing plate 292 are provided between the periodic structure layer and the AMC substrate.

[0167] In this modification, an artificial magnetic conductor (AMC) 400ε is composed of a periodic structure layer 410 sandwiching a polarizing plate 292 and a first adhesive layer 281, and a background conductor 420 provided on an AMC substrate 401. In this configuration, too, the periodic structure layer 410 of the AMC 400ε is formed on the back surface of the antenna substrate (transparent substrate 101), and the background conductor 420 of the AMC 400ε is provided on the lower surface of the AMC substrate 401.

[0168] In this configuration, when the distance from the antenna pattern 110 of the transparent antenna 100 to the periodic structure layer 410 of the AMC 400ε is h1 and the distance from the periodic structure layer 410 to the background conductor in the AMC 400ε is h2ε, the relationship of h1>h2ε holds. In Fig. 30, h2ε is the sum of the thickness of the polarizing plate 292, the thickness of the first adhesive layer 281, and the thickness of the AMC substrate 401, and therefore, by making this total thickness thicker than the transparent substrate 101 of the transparent antenna 100, the above-mentioned relationship of h1>h2ε is realized.

[0169] In this modification, the polarizing plate 292 can also be used as the thickness of h2ε constituting the AMC 400ε, so that the relationship h1>h2ε can be established without providing a polarizing plate on the antenna, even if the polarizing plate 292 and the adhesive layer 281 are thinner than those in Fig. 28. This makes it possible to further reduce the thickness of the display module 3B.

[0170] (6-4. Display module 3C according to modification 3 of the third embodiment of the present invention) Fig. 31 is an exploded cross-sectional view showing a display module 3C according to Modification 3 of the third embodiment of the present invention. Although Fig. 30 describes an example in which AMC substrate 401 for a background conductor is provided on a touch panel, the configuration having a dedicated AMC substrate 401 can also be applied to a display module that does not have a touch panel, as shown in Fig. 31.

[0171] In this modified example, as in Figure 30, an artificial magnetic conductor (AMC) 400ε is composed of a periodic structure layer 410 sandwiched between a polarizing plate 292 and a first adhesive layer 281, and a background conductor 420 provided on an AMC substrate 401.

[0172] The configuration of Fig. 31 is almost the same as that of Fig. 30, including the configuration of AMC400ε, except that it does not have a touch panel. Since the polarizing plate 292 can also be used as the thickness of h2ε constituting AMC400ε, the relationship h1>h2ε can be established without providing a polarizing plate on the antenna, even if the polarizing plate 292 and adhesive layer 282 are thinner than those in Fig. 29. This makes it possible to further reduce the thickness of the display module 3C.

[0173] (7-1. Display module 4 according to the fourth embodiment of the present invention) 32 is an exploded cross-sectional view showing a display module 4 according to a fourth embodiment of the present invention. In this configuration, the periodic structure layer of the AMC is provided on the upper surface of a dedicated AMC substrate that is separate from the transparent substrate of the transparent antenna. A part of the touch panel functions as a background conductor for the AMC. In addition, a third adhesive layer (OCA) 284 is provided between the touch panel 230 and the dedicated AMC substrate 501 to laminate the substrates in close contact with each other.

[0174] In this configuration, an AMC substrate 501, which is a dedicated substrate for the periodic structure layer 510 of the AMC 500, is provided above the touch panel 230. The AMC substrate 501 is a second transparent substrate, and is, for example, a flexible substrate made of polyimide, and is a colorless, transparent, insulating substrate that can be bent in the Z direction and / or the X direction.

[0175] In the configuration of Figure 32, an artificial magnetic conductor (AMC) 500 is formed by a periodic structure layer 510 formed on the upper surface of an AMC substrate 501, sandwiching a third adhesive layer 284, and an electrode layer 301 of the touch panel 230 that functions as a background conductor.

[0176] In this configuration, when the distance from the antenna pattern 110 of the transparent antenna 100 to the periodic structure layer 510 of the AMC500 is h3, and the distance from the periodic structure layer 510 to the electrode layer 301, which is the background conductor, in the AMC500 is h4, the relationship h3 < h4 holds.

[0177] In FIG. 32, h3 is the sum of the thickness of the transparent substrate 101 of the transparent antenna 100 and the thickness of the first adhesive layer 281, and h4 is the sum of the thickness of the substrate 501 for the AMC, the thickness of the third adhesive layer 284, and the thickness of the insulating protection layer 304 of the touch panel 230. By making the sum h4 of the thickness of the substrate 501 for the AMC, the thickness of the third adhesive layer 284, and the thickness of the insulating protection layer 304 of the touch panel 230 thicker than the sum h3 of the thickness of the transparent substrate 101 and the thickness of the first adhesive layer 281, the above relationship h3 < h4 is realized.

[0178] In this configuration, compared with the configuration of the conventional example shown in FIG. 1, the AMC500 of this configuration has a periodic structure layer and a background conductor, so it has good performance as a magnetic wall. Furthermore, since the AMC500 is configured by being laminated via the adhesive layer 284, the distance between the background conductor and the periodic structure layer can be increased, and the performance of the AMC can be improved.

[0179] Here, in this configuration, similar to FIG. 4, in order to make the touch panel function as a background conductor, for example, when the distance h4 shown in FIG. 32 is 0.15 mm, the sheet resistance value of the electrode layer 301 of the touch panel 230 is preferably less than 2.8 Ω / sq. Also, when h4 is 0.30 mm, the sheet resistance value of the electrode layer 301 of the touch panel 230 is preferably less than 5.6 Ω / sq, more preferably 5.0 Ω / sq or less.

[0180] In this example, in the touch panel 230, an example in which the electrode layer 301 is a member having a small sheet resistance value and functions as a background conductor has been described. However, by devising the wiring pattern of the electrode layer 301 of the touch panel 230, the thickness of the electrode layer 301, and the material of the insulation protection layer 304 from the existing ones as described above, the sheet resistance value of the touch panel 230 may be adjusted.

[0181] Also, in this example, in the substrate 501 for AMC, an example in which the periodic structure layer 510 is provided on the upper side has been described. However, the periodic structure layer 510 may be formed on the lower side of the substrate 501 for AMC. In this case, it is preferable to design such that the sum of the thickness of the transparent substrate 101 of the transparent antenna 100, the thickness of the first adhesive layer 281, and the thickness of the substrate 501 for AMC is thinner than the sum of the thickness of the third adhesive layer 284 and the thickness of the insulation protection layer 304 of the touch panel 230.

[0182] (7-2. Display Module 4A According to a Modified Example of the Fourth Embodiment of the Present Invention) FIG. 33 is a cross-sectional exploded view showing a display module 4A according to a modified example of the fourth embodiment of the present invention. In FIG. 32, an example in which a dedicated substrate 501 for AMC for the periodic structure layer of AMC is provided on the touch panel has been described. However, the configuration of AMC having the substrate 501 for AMC for the periodic structure layer as in the present embodiment can also be applied to a display module that does not have a touch panel, as shown in FIG. 33.

[0183] In the configuration of FIG. 33, an artificial magnetic conductor (AMC) 500ζ is constituted by the periodic structure layer 510 formed on the upper surface of the substrate 501 for AMC with the third adhesive layer 284 interposed therebetween and the transparent electrode 26 of the display panel 220 that functions as a background conductor.

[0184] In this configuration, when the distance from the antenna pattern 110 of the transparent antenna to the periodic structure layer 510 of the AMC is h3 and the distance from the periodic structure layer 510 to the background conductor in the AMC is h4ζ, there is a relationship of h3 < h4ζ.

[0185] In FIG. 33, h3 is the sum of the thickness of the transparent substrate 101 of the transparent antenna 100 and the thickness of the first adhesive layer 281, and h4ζ is the sum of the thickness of the AMC substrate 501 and the thickness of the third adhesive layer 284. By making the sum h4ζ of the thickness of the AMC substrate 501 and the thickness of the third adhesive layer 284 thicker than the sum h3 of the thickness of the transparent substrate 101 and the thickness of the first adhesive layer 281, the relationship h3 < h4ζ described above is realized.

[0186] In this configuration, as described above, since the AMC 500ζ is formed by being laminated via the adhesive layer 284, the distance between the background conductor and the periodic structure layer can be increased, and the performance of the AMC can be improved.

[0187] Here, in this configuration, as in FIG. 25, in order to make the display panel 220 function as a background conductor, for example, when h4ζ is 0.15 mm, the sheet resistance value of the transparent electrode 26 is preferably less than 2.8 Ω / sq. Further, when h4ζ is 0.30 mm, the sheet resistance value of the transparent electrode 26 functioning as an AMC is preferably less than 5.6 Ω / sq, more preferably 5.0 Ω / sq or less.

[0188] In this example, an example in which the transparent electrode 26 of the display panel 220 functions as the background conductor of the AMC has been described. However, as described above, as a part of the components of the display panel 220, a dedicated member (for example, a pattern electrode) for the background conductor of the AMC may be provided on the transparent electrode 26.

[0189] In this example, an example in which the periodic structure layer 510 is provided on the upper side of the AMC substrate 501 has been described. However, the periodic structure layer 510 may be formed on the lower side of the AMC substrate 501. In this case, it is preferable to design such that the sum of the thickness of the transparent substrate 101 of the transparent antenna 100, the thickness of the first adhesive layer 281, and the thickness of the AMC substrate 501 is thinner than the thickness of the third adhesive layer 284.

[0190] (8. Display Module 5 According to the Fifth Embodiment of the Present Invention) FIG. 34 is an exploded cross-sectional view showing a display module 5 according to the fifth embodiment of the present invention. In this configuration, the periodic structure layer of the AMC is provided on the upper surface of a dedicated AMC substrate that is separate from the transparent substrate of the transparent antenna, and the background conductor of the AMC is provided on the lower surface of the substrate for the AMC. Further, in order to stack the substrates in close contact with each other, a third adhesive layer (OCA) 284 is provided between the touch panel 230 and the dedicated AMC substrate 501.

[0191] In this configuration, the AMC substrate 501 having the periodic structure layer 510 provided on the upper surface and the background conductor 520 provided on the lower surface is provided above the touch panel 230. The AMC substrate 501 is a second transparent substrate, and is, for example, a flexible substrate made of polyimide, and is a colorless transparent insulating material substrate that can be bent in the Z direction and / or the X direction.

[0192] In the configuration of FIG. 34, an artificial magnetic conductor (AMC) 500η is constituted by the periodic structure layer 510 formed on the upper surface of the AMC substrate 501 and the background conductor 520 formed on the lower surface.

[0193] In this configuration, when the distance from the antenna pattern 110 of the transparent antenna 100 to the periodic structure layer 510 of the AMC 500η is h3, and the distance from the periodic structure layer 510 to the background conductor 520 in the AMC 500η is h5, the relationship h3 < h5 holds.

[0194] In FIG. 34, h3 is the sum of the thickness of the transparent substrate 101 of the transparent antenna 100 and the thickness of the first adhesive layer 281, and h5 is the thickness of the AMC substrate 501. By making the thickness h5 of the AMC substrate 501 thicker than the sum h3 of the thickness of the transparent substrate 101 and the thickness of the first adhesive layer 281, the above relationship h3 < h5 is realized.

[0195] In this configuration, compared to the conventional configuration shown in Figure 1, AMC500η has a periodic structure layer and a background conductor in the same substrate, so antenna gain loss can be significantly reduced compared to AMCs that do not have a background conductor. In addition, in this configuration, AMC500η is realized by a single substrate, but does not have vias that conduct electricity from top to bottom, so complicated manufacturing can be avoided.

[0196] In this example, an example has been described in which an AMC 500η having a dedicated AMC substrate is provided on the touch panel 230, but in a display module, the AMC 500η of this configuration may be provided on the display panel 220 without providing the touch panel 230.

[0197] Although the transparent antenna of the present invention can function as an antenna even with only one, in order to further improve the characteristics, a plurality of transparent antennas may be arranged in an array state (antenna array). When a plurality of transparent antennas are provided, it is preferable to provide a periodic structure layer on the lower surface or the lower side of the transparent substrate of all the antennas, and to provide the same number of AMCs as the transparent antennas.

[0198] Although a transparent antenna according to an exemplary embodiment of the present invention has been described above, the present invention is not limited to the specifically disclosed embodiment, and various modifications and variations are possible without departing from the scope of the claims.

[0199] This international application claims priority based on Japanese Patent Application No. 2020-102629, filed on June 12, 2020, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0200] 1,1A,2,2A,3,3A,3B,3C,4,4A,5 Display Module 26 Cathode (background conductor for AMC) 61 Measurement model of pseudo-AMC 62 Measurement model of pseudo-AMC 63 Antenna alone (measurement model) 64 Pseudo display module with AMC (measurement model) 65 Comparative example pseudo display module (measurement model) 80 Transparent Conductor 81 Fine metal wire 82 Fine metal wire 83 Opening 100 Transparent Antenna 101 Transparent substrate (antenna substrate) 110 Antenna pattern (transparent conductor, thin metal wire layer) 200 Electronic equipment 210 Cabinet 220 Display Panel (OLED Display Panel, Display) 230 Touch panel (metallic thin wire layer for on-cell touch panel, on-cell metallic thin wire layer) 240 Transparent cover (cover glass) 250 Wiring Board 260A, 260B, 260C, 260D Electronic Components 270 Battery 281 First adhesive layer (OCA, adhesive layer) 282 Second adhesive layer (OCA) 283,284 Third adhesive layer (OCA) 291 Polarizing Plate 292 Polarizing Plate 300 On-cell metal wire layer 301 Electrode layer (background conductor for AMC) 304 Insulating protective layer 400, 400α, 400β, 400γ, 400δ, 400ε AMC (artificial magnetic conductor) 401 AMC substrate (second transparent substrate) 410 Periodic structure layer 420 Background Conductor for AMC 500,500ζ,500η AMC (Artificial Magnetic Conductor) 501 AMC substrate (second transparent substrate) 510 Periodic structure layer 520 Background Conductor P Floating conductor M Metal conductor h1 Thickness of transparent conductor (distance from antenna pattern to periodic structure layer) h2, h2α, h2β, h2γ, h2δ, h2ε (distance from the periodic structure layer to the background conductor) h3 Total thickness of the transparent conductor and the third adhesive layer (distance from the antenna pattern to the periodic structure layer) h4,h4ζ Distance from the periodic structure layer to the background conductor h5 Thickness of the AMC substrate (distance from the periodic structure layer to the background conductor) p81, p82 Line spacing between metal fine wires (wiring pitch) w81, w82: The line width (wiring width) of each of the metal thin wires that make up the mesh

Claims

1. A display and a transparent antenna disposed above the display, the transparent antenna having a transparent substrate and an antenna pattern formed on the transparent substrate; An artificial magnetic conductor arranged below the transparent antenna; Equipped with The artificial magnetic conductor comprises: A periodic structure layer, and Including a background conductor; The antenna pattern of the transparent antenna and the periodic structure layer of the artificial magnetic conductor are made of a mesh-shaped conductor, and the mesh-shaped conductor has a wiring width of 5 μm or less and is made of a transparent conductor with a wiring pitch determined so as to obtain a transmittance of 70% or more in visible light; The distance from the antenna pattern of the transparent antenna to the periodic structure layer of the artificial magnetic conductor is h1; In the artificial magnetic conductor, when the distance from the periodic structure layer to the background conductor is h2, The relationship is h1<h2. Display module.

2. The sheet resistance of the background conductor is 5 Ω / sq or less. The display module of claim 1 .

3. The periodic structure layer of the artificial magnetic conductor is provided on the lower surface of the transparent substrate of the transparent antenna.

3. A display module according to claim 1 or 2.

4. a touch panel provided below the periodic structure layer and above the display, the touch panel having a thin metal wire layer formed directly on an upper surface thereof; The metal thin wire layer of the touch panel is the background conductor of the artificial magnetic conductor. The display module according to claim 3 .

5. The display includes a light-emitting layer, a bottom anode, and a top cathode; The cathode of the display is the background conductor of the artificial magnetic conductor. The display module according to claim 3 .

6. a second transparent substrate provided below the transparent antenna and above the display; The background conductor of the artificial magnetic conductor is provided on the lower surface of the second transparent substrate. The display module according to claim 3 .

7. a second transparent substrate provided below the transparent antenna and above the display; The periodic structure layer of the artificial magnetic conductor is provided on the upper surface of the second transparent substrate.

3. A display module according to claim 1 or 2.

8. A touch panel is provided below the periodic structure layer and above the display, and has a metal thin line layer formed directly on the upper surface. The metal thin wire layer of the touch panel is the background conductor of the artificial magnetic conductor.

8. The display module of claim 7.

9. The display includes a light-emitting layer, a bottom anode, and a top cathode; The cathode of the display is the background conductor of the artificial magnetic conductor.

8. The display module of claim 7.

10. The artificial magnetic conductor has a periodic structure layer and a background conductor. The periodic structure layer and the background conductor are provided with an adhesive layer that transmits radio waves. A display module according to any one of the preceding claims.

11. The artificial magnetic conductor further includes a polarizing plate that is disposed between the periodic structure layer of the artificial magnetic conductor and the background conductor and transmits radio waves. The display module of claim 10.

12. a second transparent substrate provided below the transparent antenna and above the display; The periodic structure layer of the artificial magnetic conductor is provided on the upper surface of the second transparent substrate, The background conductor of the artificial magnetic conductor is provided on the lower surface of the second transparent substrate. The display module of claim 1 .

13. In the artificial magnetic conductor, the periodic structure layer and the background conductor are not conductive. A display module according to any one of the preceding claims.

14. The transparent antenna transmits and receives radio waves in the range of 24.2 to 29.5 GHz; h2 = 0.15 mm, the periodic structure layer is configured by periodically arranging a plurality of square floating conductors; One side of the floating conductor is 2.8 to 3.4 mm, The spacing between floating conductors is configured to be 0.5 to 1.5 mm. A display module according to any one of the preceding claims.

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