Antenna device and electronic device

Abstract

To provide an antenna device which is realized by a metal mesh, and can achieve both of a suppression of Moire and an improvement of an antenna characteristic.SOLUTION: An antenna device contains: a metal mesh antenna element that is provided onto a front surface of a first insulation substrate; and a power supply line that is provided onto the front surface of the first insulation substrate, is made of the metal mesh, and is extended between a first end part and a second end part connected to a power supply part of the antenna element. The power supply line is extended from the first end part to a second shaft direction to a first shaft and the second shaft which are orthogonal each other while being contained in the front surface, and the first insulation substrate is provided to the front surface side of a display device. A plurality of pixels provided in the display device, is arranged along a first shaft direction and a second shaft direction. Each metal mesh of the antenna element and the power supply line contains a plurality of cells having a first length in the first shaft direction and a second length in the second shaft direction, and an extension direction of a metal thin line constructing the plurality of cells has an angle to the first and second shaft directions, where a second length is longer than a first length.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to an antenna device and an electronic device. [Background technology]

[0002] Conventionally, there has been an antenna-on-display in which a coplanar waveguide is connected to an antenna element provided on the surface of a substrate, and the antenna element and the coplanar waveguide are formed of a transparent conductor, and the antenna device is mounted on a display. The transparent conductor is a metal mesh that is so fine that it is invisible to the human eye. The metal mesh is rhomboidal, and the length of the rhomboid shape along the extension direction of the coplanar waveguide is longer than the length along the width direction perpendicular to the extension direction of the coplanar waveguide in a planar view (see, for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] An Optically Invisible Antenna-on-Display Concept for Millimeter-Wave 5G Cellular Devices, IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 67, NO. 5, MAY 2019 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional antenna device does not describe a specific relationship between the pixel arrangement direction of the display device and the diamond shape of the metal mesh, nor does it describe the advantages and reasons for making the length of the diamond shape along the extension direction of the coplanar lines longer than the length along the width direction of the coplanar lines.

[0005] Therefore, an object of the present invention is to provide an antenna device and electronic device that are realized using a metal mesh and can simultaneously suppress moire and improve antenna characteristics. [Means for solving the problem]

[0006] An antenna device according to an embodiment of the present disclosure includes a first insulator substrate, an antenna element formed of a metal mesh and provided on a surface of the first insulator substrate, and a feed line formed of a metal mesh and provided on the surface of the first insulator substrate, the feed line extending between a first end and a second end connected to a power supply portion of the antenna element, wherein the feed line extends from the first end in a second axial direction with respect to a first axis and a second axis that are included on the surface and are orthogonal to each other, the first insulator substrate is provided on a display surface side of a display device, and a plurality of pixels of the display device are arranged along the first axial direction and the second axial direction, the metal mesh of the antenna element and the feed line includes a plurality of cells having a first length in the first axial direction and a second length in the second axial direction, and an extension direction of thin metal wires constituting the plurality of cells forms an angle with respect to the first axial direction and the second axial direction, and the second length is longer than the first length. a first pitch of the pixels in the first axis direction is different from the first length; and a second pitch of the pixels in the second axis direction is different from the second length. . [Effects of the Invention]

[0007] It is possible to provide an antenna device and electronic device that are realized using a metal mesh and can simultaneously suppress moire and improve antenna characteristics. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall view showing an example of the position of an antenna device 100 in an electronic device 200 equipped with a display module D. FIG. [Figure 2] 2 is a diagram showing an example of the configuration of the cross section of the electronic device 200 of FIG. 1 taken along the line AA. [Figure 3] 10 is a diagram showing an example of a cross-sectional configuration of a display module D. FIG. [Figure 4]1 is a perspective view showing an example of the configuration of an antenna device 100. FIG. [Figure 5] FIG. 2 is a diagram showing an example of an exploded state of the antenna device 100. [Figure 6] 2 is a diagram showing an example of the configuration of a transparent conductor 30 of the antenna device 100. FIG. [Figure 7] 10A is an exemplary diagram illustrating why the length Y30A in the Y direction is longer than the length X30A in the X direction. FIG. [Figure 8] 10 is a diagram illustrating an example of frequency characteristics of the S11 parameter of the antenna device 100. FIG. [Figure 9] 10 is a diagram showing an example of the directivity of the antenna device 100 in the YZ plane. [Figure 10] 10 is a diagram showing an example of the relationship between the shape of the cell of the transparent conductor 30 and the efficiency and peak gain. FIG. [Figure 11A] FIG. 10 is a diagram illustrating an example of the configuration of a cell 30MA1 according to a modified example of the embodiment. [Figure 11B] FIG. 10 is a diagram illustrating an example of the configuration of a cell 30MA2 according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the antenna device and electronic device according to the present disclosure will be described. In the following, the same elements will be denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0010] In the following description, an XYZ coordinate system is defined. The direction parallel to the X axis (X direction), the direction parallel to the Y axis (Y direction), and the direction parallel to the Z axis (Z direction) are perpendicular to one another. For ease of explanation, the -Z direction may be referred to as the lower side or bottom, and the +Z direction may be referred to as the upper side or top. A planar view refers to a view from the XY plane. In the following description, the length, width, thickness, etc. of each part may be exaggerated to make the configuration easier to understand. Terms such as parallel, right angle, orthogonal, horizontal, vertical, top and bottom, etc., are permitted to deviate to the extent that they do not impair the effects of the embodiments.

[0011] <Embodiment> <Electronic equipment 200> 1 and 2, the configuration of an electronic device 200, which is an example of a communication device equipped with a display module D including an antenna device 100 of the present disclosure, will be described. Fig. 1 is an overall view showing an example of the position of the antenna device 100 in the electronic device 200 equipped with the display module D. Fig. 2 is a diagram showing an example of the configuration of a cross section of the electronic device 200 in Fig. 1 taken along the line AA.

[0012] 1 and 2, the X direction indicates the vertical direction of electronic device 200 (the longitudinal direction of the device), the Y direction indicates the horizontal direction of electronic device 200 (the direction of the short sides of the device), and the Z direction indicates the height direction of electronic device 200. In the following, an XYZ coordinate system is defined and explained. For convenience of explanation, a planar view refers to an XY plane view, and explanation is given using a vertical direction with the +Z direction side being the upper side and the -Z direction side being the lower side, and a horizontal direction (side) relative to the vertical direction, but these do not represent universal vertical and horizontal directions.

[0013] Furthermore, deviations in directions such as parallel, right-angled, orthogonal, horizontal, vertical, up-down, left-right, etc. are permitted to the extent that they do not impair the effects of the disclosure in the embodiments. The X, Y, and Z directions represent directions parallel to the X axis, Y axis, and Z axis, respectively. The X, Y, and Z directions are perpendicular to one another. The XY plane, YZ plane, and ZX plane represent imaginary planes parallel to the X and Y directions, imaginary planes parallel to the Y and Z directions, and imaginary planes parallel to the Z and X directions, respectively. The X, Y, and Z axes are examples of the first, second, and third axes, respectively, and the X, Y, and Z directions are examples of the first, second, and third axis directions, respectively.

[0014] The electronic device 200 is, for example, an information processing terminal such as a smartphone, a tablet computer, a notebook PC (Personal Computer), etc. Furthermore, the electronic device 200 is not limited to these, and may be, for example, a structure such as a pillar or a wall, digital signage, an electronic device including a display panel inside a train, or an electronic device including various display panels inside a vehicle.

[0015] 1 and 2, a display module D capable of displaying information is disposed on the entire top surface of the electronic device 200, or on at least a portion of the top surface. The antenna device 100 is disposed above a touch panel 230 on a display panel 220. The upper side of the antenna device 100 is visible from outside the electronic device 200 through a transparent cover 240, which is transparent so that the display panel 220 can be seen from the outside through the antenna device 100. The display panel 220 is an example of a display device. The display surface of the display panel 220 is the surface on the +Z direction side of the display panel 220.

[0016] 2, in electronic device 200, display panel 220, touch panel 230, antenna device 100, and transparent cover 240 are collectively referred to as a display module D (also referred to as a display module).

[0017] In addition to the display module D, 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.

[0018] 1 and 2 show an example in which the electronic device 200 in which the antenna device 100 is mounted is a smartphone, but the electronic device in which the antenna device 100 is mounted may have other configurations as long as it includes a housing 210, a transparent cover 240, and a display panel 220. Furthermore, the electronic device 200 may not be provided with a touch panel 230.

[0019] 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 edge 211 which is the upper end of the peripheral wall, and transparent cover 240 is attached to opening edge 211. Housing 210 has storage section 212 which is an internal space communicating with opening edge 211, and storage section 212 stores wiring board 250, electronic components 260A to 260D, battery 270, etc.

[0020] 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 edge 211 of housing 210 in a plan view. In this example, transparent cover 240 is an example of a glass plate that is mostly flat and has both ends in the horizontal direction (±Y direction) that are gently curved downward, but it may also be a glass plate that is flat in the horizontal direction. Alternatively, transparent cover 240 may also have both ends in the vertical direction (±X direction) of electronic device 200 that are gently curved downward. Here, a form in which transparent cover 240 is made of glass will be described, but transparent cover 240 may also be made of resin.

[0021] The transparent cover 240 is attached to the open end 211 of the housing 210, thereby sealing the storage section 212 of the housing 210.

[0022] 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 antenna device 100 and the touch panel 230 are provided on the inner surface side of the transparent cover 240. Because 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.

[0023] Electronic components 260A to 260C are mounted on wiring board 250. A feeder line shown by a dotted line in FIG. 2, which extends from feeder line 120 of the antenna device (see FIG. 5), and the like are connected to wiring board 250. Wiring board 250 and feeder line 120 of antenna device 100 may be connected using a connector, an anisotropic conductive film (ACF), or the like, or may be connected using other components.

[0024] As an example, electronic component 260A is a communication module that is connected to feeder line 120 of antenna device 100 via wiring on wiring board 250 and processes signals transmitted or received via antenna device 100. Furthermore, central electronic component 260B is, for example, a camera.

[0025] As an example, electronic components 260C and 260D are components that perform information processing related to the operation of electronic device 200, and are realized by a computer that includes, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), an input / output interface, and an internal bus.

[0026] The battery 270 is a rechargeable secondary battery, and supplies the power required for the operation of the display module D, the electronic components 260A to 260D, and the like.

[0027] <Display Module D> Next, a description will be given of the position of the antenna device 100 in the display module D. FIG.

[0028] Although not shown in FIG. 2, the display module D has a polarizer 280 between the touch panel 230 and the transparent cover 240 as shown in FIG. 3. Although shown as a single component in FIG. 2, the antenna device 100 is actually composed of two substrates, a first transparent substrate 101 and a second transparent substrate 102, sandwiching the polarizer 280. The first transparent substrate 101 is an example of a first insulator substrate, and the second transparent substrate 102 is an example of a second insulator substrate. The top surface (the surface on the +Z direction side) of the first transparent substrate 101 is an example of a front surface. The second transparent substrate 102 is provided closer to the display panel 220 than the first transparent substrate 101.

[0029] The adhesive layers provided from top to bottom are a first adhesive layer 291, a second adhesive layer 292, a third adhesive layer 293, and a fourth adhesive layer 294. The first adhesive layer 291 to the fourth adhesive layer 294 are made of a transparent optical adhesive OCA (Optical Clear Adhesive).

[0030] 3 shows an example in which the touch panel 230 is a "metal thin line layer for an on-cell touch panel" formed directly on the surface of the display panel 220 without an adhesive layer. However, an adhesive layer may be provided between the touch panel 230 and the display panel 220.

[0031] 2 and 3 show an example in which the touch panel 230 is provided in the display module D, but the display module D mounted on the electronic device 200 does not necessarily have to be mounted with the touch panel 230.

[0032] The display panel 220 is, for example, a liquid crystal display panel, an organic EL (Electro-luminescence) or an OLED (Organic Light Emitting Diode) display panel. In either configuration, it is disposed at the bottom of the display module D.

[0033] 1, the antenna device 100 is provided partially in the display module D, so that the touch panel 230, the polarizing plate 280, and / or the first to fourth adhesive layers 291 to 294 may be made thinner in the area where the antenna device 100 is provided than in other areas, or the polarizing plate 280 and / or the first to fourth adhesive layers 291 to 294 may not be provided. This makes it possible to prevent only the area where the antenna device 100 is provided from being raised in the display module D.

[0034] Furthermore, if the antenna device 100 is too thick, the edges of the antenna device 100 may be visible, and air may easily become trapped at the boundaries with the first to fourth adhesive layers 291 to 294. The thickness of each of the first transparent substrate 101 and the second transparent substrate 102 of the antenna device 100 is preferably 300 μm or less, more preferably 150 μm or less, and particularly preferably 100 μm or less. From the viewpoint of ease of handling, the thickness of each of the transparent substrates 101, 102 of the antenna device 100 is preferably 10 μm or more, and more preferably 50 μm or more.

[0035] Furthermore, in the antenna device 100, the first transparent substrate 101 and the second transparent substrate 102 may have different substrate sizes in the ±X and ±Y directions. Furthermore, the transparent substrates 101 and 102 constituting the antenna device 100 may have the same or different substrate thicknesses, but if they are different, it is preferable that the relationship be such that the thickness t1 of the first transparent substrate 101 is smaller than the thickness t2 of the second transparent substrate 102.

[0036] Furthermore, as will be described later, in the antenna device 100, the first transparent substrate 101 and the second transparent substrate 102 are not connected by wiring but are connected by AC current. The second adhesive layer 292, the polarizing plate 280, and the third adhesive layer 293 function as dielectrics sandwiched between the first transparent substrate 101 and the second transparent substrate 102. It is preferable that the dielectric constants ε of the second adhesive layer 292, the polarizing plate 280, and the third adhesive layer 293 be within a range between the dielectric constant ε1 of the first transparent substrate 101 and the dielectric constant ε2 of the second transparent substrate 102.

[0037] 1 and 2 show an example in which both ends of the display module D in the ±Y direction are gently curved, but the display module D may have a flat shape with no curved ends. In that case, the antenna device 100 may also have a flat shape. Note that when the antenna device 100 has a partially curved surface, the transmission region, which will be described later, will have a curved shape.

[0038] <Configuration example of antenna device> Next, an example of the configuration of the antenna device 100 will be described with reference to Figs. 4 to 6 in addition to Fig. 3. Fig. 4 is a perspective view showing an example of the configuration of the antenna device 100. Fig. 5 is a view showing an example of an exploded state of the antenna device 100. Fig. 5(A) is a top view of the first transparent substrate 101 as seen from the +Z direction, and Fig. 5(B) is a bottom view of the first transparent substrate 101 as seen from the -Z direction. Fig. 5(C) is a top view of the second transparent substrate 102 as seen from the +Z direction, and Fig. 5(D) is a bottom view of the second transparent substrate 102 as seen from the -Z direction. Note that even when a portion of the antenna device 100 is arranged along a curve as in Fig. 1, Fig. 4 shows the antenna device 100 in a state parallel to the XY plane before it is bent.

[0039] In the antenna device 100, an antenna element 110 and a feed line 120 are provided on the upper surface (front surface) of a first transparent substrate 101. The antenna element 110 is an example of a patch antenna. A ground layer 130 is provided on the lower surface (back surface) of a second transparent substrate 102. The antenna element 110 and the feed line 120 may also be provided on the lower surface of the first transparent substrate 101.

[0040] 3, a second adhesive layer 292, a polarizing plate 280, and a third adhesive layer 293 are provided between the first transparent substrate 101 and the second transparent substrate 102. The distance ds between the first transparent substrate 101 and the second transparent substrate 102 shown in FIG. 4 is approximately 150 μm.

[0041] 4, the antenna element 110 is provided on the upper surface of the first transparent substrate 101, and the ground layer 130 is provided on the lower surface of the second transparent substrate 102. The distance dm between the antenna element 110 and the ground layer 130 is approximately 500 μm. The distance dm is 100 μm or more, preferably 200 μm or more, and more preferably 300 μm or more.

[0042] As shown in FIG. 3, the second transparent substrate 102 is disposed immediately above the touch panel 230 or the display panel 220, with an adhesive layer 294 sandwiched therebetween. Therefore, it is preferable that the retardation δ2, which is the product (Δnd) of the refractive index difference (Δn) with respect to the direction of polarization and the thickness (d) of the substrate, be low. On the other hand, since the first transparent substrate 101 is separated from the touch panel 230 or the display panel 220, it is not necessary that the retardation δ1 be low. Therefore, it is preferable that the retardations of the first transparent substrate 101 and the second transparent substrate 102 have a relationship of δ1≧δ2, and may be δ1>δ2.

[0043] To satisfy the above retardation, the first transparent substrate 101 is made of PET (polyethylene terephthalate resin) or COP (cycloolefin polymer), and the second transparent substrate 102 is made of, for example, COP. For example, the retardation of PET is 5061.7 nm at a thickness of 100 μm, and the retardation of COP is 3.77 nm at a thickness of 100 μm.

[0044] As mentioned above, for the same thickness, retardation is a value that increases or decreases depending on the birefringence caused by the substrate material, and is an amount that affects the clarity of images, etc. Therefore, retardation is evaluated using light in the visible light range (wavelengths of 380 nm to 780 nm).

[0045] On the other hand, the dielectric constant is a quantity related to the antenna characteristics. Therefore, the dielectric constant is evaluated within the wavelength range of the radio waves used. The dielectric constant ε2 of the second transparent substrate 102 is preferably lower than the dielectric constant ε1 of the first transparent substrate 101. With a low ε2, the pitch between the thin metal wires of the ground layer 130 becomes relatively narrow in terms of electrical length, thereby suppressing leakage of radio waves from the ground layer 130 downward. For example, the dielectric constant of the PET constituting the first transparent substrate 101 is 3.31 at 35 GHz, and the dielectric constant of the COP constituting the second transparent substrate 102 is 2.31 at 35 GHz.

[0046] Furthermore, to ensure that the antenna device 100 is colorless and transparent, it is preferable that the transmittance of each of the substrates 101, 102 is 80% or more, and both of the transparent substrates 101, 102 are flexible substrates that can be bent in the Z direction and / or the X direction.

[0047] The antenna element 110 is a patch-type antenna element provided near the center in the X direction of the first transparent substrate 101. The antenna element 110 has a rectangular shape in a plan view, and includes a feeding portion 111 and a recess 112.

[0048] Recess 112 is a portion where the center of an end side extending in the X direction on the −Y direction side of antenna element 110 is recessed toward the +Y direction, and power supply portion 111 is located in the X direction center of recess 112. Power supply portion 111 is connected to signal line 121B of power supply line 120, and recess 112 is divided into the +X direction side and the −X direction side by signal line 121B.

[0049] The antenna element 110 is provided on the upper surface of the first transparent substrate 101. The recess 112 is provided to match the radiation resistance, which is determined by the thickness and dielectric constant of the peripheral members of the antenna element 110 and the patch element size, with the feed line impedance.

[0050] Here, the length of the antenna element 110 in the X direction is defined as X110, and the effective length in the Y direction is defined as Y110. X110 is the overall length of the antenna element 110 in the X direction, and Y110 is the length from the end of the antenna element 110 on the +Y direction side to the power feeding point 111. Since the antenna element 110 is excited in the Y direction, Y110 is the effective length of the antenna element 110 in the excitation direction.

[0051] If the wavelength on the first transparent substrate 101 at the resonant frequency f1 (28 GHz) of the antenna device 100 is λ (electrical length), Y110 is set to an integer multiple of approximately 0.5λ, and X110 is set to a value smaller than 1.0λ. Therefore, if it is desired to improve the antenna gain at the resonant frequency f1, X110 and Y110, which define the size of the antenna element 110, should be adjusted to within ±10% of approximately 2.5 mm, for example.

[0052] The feed line 120 is disposed at a longitudinal end (-Y direction end) of the first transparent substrate 101. The feed line 120 has, for example, a coplanar waveguide (CPW) section and a microstrip line (MSL) section. The feed line 120 has a signal line 121 extending on the upper surface of the first transparent substrate 101 at the center of the first transparent substrate 101 in the X direction, and planar ground portions 122 and 123 sandwiching the signal line 121 in the X direction.

[0053] The signal line 121 has a signal line 121A on the −Y direction side and a signal line 121B on the +Y direction side. The signal line 121A is the portion of the signal line 121 on the −Y direction side, and the signal line 121B is the portion of the signal line 121 on the +Y direction side. The end 121A1 on the −Y direction side of the signal line 121 is located near an edge of the first transparent substrate 101 on the −Y direction side, extending in the X direction, and is an example of a first end. The end 121B1 on the +Y direction side of the signal line 121B is an example of a second end. The end 121B1 is connected to the power feed portion 111 of the antenna element 110.

[0054] Signal line 121A is a portion sandwiched between ground portions 122 and 123 to form a coplanar waveguide, and signal line 121B is a portion to form an MLS. Signal line 121B forms a microstrip line by overlapping with ground layer 130 on the lower surface of second transparent substrate 102. Note that, because ground layer 130 is provided over the entire lower surface of second transparent substrate 102, signal line 121A of signal line 121 also overlaps with ground layer 130.

[0055] In this configuration example, the signal line 121 and the ground portions 122 and 123 that constitute the feeder line 120 are all provided on the upper surface of the first transparent substrate 101.

[0056] When the antenna device 100 is incorporated into the electronic device 200, the signal line 121 of the feeder line 120 is electrically connected to the wiring board 250 and the electronic component 260A, which is a communication circuit, and power is supplied to them. While Fig. 4 shows an example in which the feeder line 120 is provided over approximately half the section in the Y direction from the end on the -Y direction side, the feeder line 120 may be provided over approximately one-quarter to three-quarters of the section on the -Y direction side. Furthermore, the first transparent substrate 101 may have a portion that extends further in the -Y direction, and a signal line that is positioned further in the -Y direction than the signal line 121 and is made of metal foil or the like rather than a metal mesh may be connected to the end 121A1 on the -Y direction side of the signal line 121.

[0057] 4 illustrates an example in which the end of the power supply line 120 extends to the end (-Y side end) of the first transparent substrate 101, but part or all of the power supply line 120 may be located outside the periphery of the first transparent substrate 101. Furthermore, by forming the power supply line 120 to be flexible, the power supply line 120 may be able to wrap around the side edge or rear surface of the display module D and be electrically connected on the side surface or rear surface.

[0058] On the other hand, in the second transparent substrate 102 on the lower side of the antenna device 100, the ground layer 130 is provided over the entire lower surface of the second transparent substrate 102.

[0059] The ground layer 130 preferably covers at least the entire area of ​​the antenna element 110 on the +Y side, and is further preferably arranged with a margin of +2.5 mm in the Y direction and 2.5 mm in the X direction from the end of the antenna element 110.

[0060] 4 and 5 show an example of a configuration in which the first transparent substrate 101 and the second transparent substrate 102 have the same vertical and horizontal sizes (X101=X102, Y101=Y102) and are completely overlapped in the up-down direction, but the vertical and horizontal sizes of the first transparent substrate 101 and the second transparent substrate 102 may be different, or they may only partially overlap in a planar view. When the first transparent substrate 101 and the second transparent substrate 102 are misaligned in size or position, it is sufficient that the ground layer 130 of the second substrate 102 overlaps with the antenna element 110 and the ground portions 122 and 123 of the feeder line 120 at least in the X and Y directions.

[0061] Here, the antenna element 110, the feed line 120, and the ground layer 130 shown in a mesh shape in FIGS. 4 and 5 are made up of a transparent conductor 30 shown in FIG.

[0062] <Transparent conductor (thin metal wire layer) of antenna device> Fig. 6 is a diagram showing an example of the configuration of the transparent conductor 30 of the antenna device 100. The transparent conductor 30 is formed on the outermost surfaces of the first transparent substrate 101 and the second transparent substrate 102, and is used to form, for example, the antenna element 110, the feed line 120, and the ground layer 130 shown in Fig. 4 and Fig. 5. The transparent conductor 30 is a conductor with such high optical transparency that it is difficult for the human eye to see.

[0063] The transparent conductor 30 is a layer of conductive lines, for example, formed in a mesh shape to enhance light transmittance, and is a thin metal wire layer. As shown in Fig. 6, the mesh-like thin metal wire layer constituting the transparent conductor 30 is arranged so that a plurality of thin metal wires 31 extending in one direction intersect with a plurality of thin metal wires 32 extending in the other direction, and openings (through holes) 33, which are mesh-like gaps (openings), are formed.

[0064] When the transparent conductor 30 is formed in a mesh shape, the openings 33 of the mesh may be rhombic or any polygonal shape other than rhombic, but here we will explain a case where the openings 33 are rhombic. The transparent conductor 30 has a plurality of openings 33, and the plurality of openings 33 basically only need to have the same shape, but the shapes of the openings 33 at the outer edges of the antenna element 110, the feed line 120, or the ground layer 130 do not need to be the same. Figure 6 shows a portion where the openings 33 all have the same shape.

[0065] The transparent conductor 30 includes a plurality of cells 30A. Each cell 30A has one opening 33. The plurality of cells 30A included in the transparent conductor 30 all have the same shape, and in this example, the length Y30A in the Y direction is longer than the length X30A in the X direction. The length X30A in the X direction is an example of a first length in the first axis direction, and the length Y30A in the Y direction is an example of a second length in the second axis direction. The Y direction is the longitudinal direction of the cell 30A. The reason why the length Y30A in the Y direction is longer than the length X30A in the X direction will be described later with reference to FIG. 7.

[0066] The pixels of the display panel 220 are arranged along the X and Y directions. The extension directions of the thin metal wires 31 and 32 are angled with respect to the X and Y directions, and are therefore oblique to the X and Y directions. Here, the extension directions of the thin metal wires 31 and 32 having an angle with respect to the X and Y directions means that the angle is greater than 0 degrees in absolute value. Moiré can be suppressed by having the extension directions of the thin metal wires 31 and 32 at an angle with respect to the arrangement direction of the pixels of the display panel 220. Note that at the outer edges of the antenna element 110, the feed line 120, or the ground layer 130, there may be a portion where the thin metal wires 31 or 32 are parallel to the arrangement direction of the pixels of the display panel 220.

[0067] The line widths w31 and w32 of the fine metal wires 31 and 32 constituting the mesh are preferably 1 to 10 μm, and more preferably 1 to 5 μm. The line widths w31 and w32 are widths in a direction perpendicular to the extension direction of the fine metal wires 31 and 32 in a plan view. The length X30A of the cell 30A in the X direction is preferably 50 μm to 500 μm, and more preferably 100 μm to 400 μm. Here, as an example, X30A is 100 μm. The length Y30A of the cell 30A in the Y direction is preferably 50 μm to 500 μm, and more preferably 100 μm to 400 μm. Here, as an example, Y30A is 200 μm.

[0068] The aperture ratio, which is the ratio of the area of ​​the openings 33 to the entire mesh in the transparent conductor 30, is preferably 80% or more, and more preferably 90% or more. The greater the aperture ratio of the transparent conductor 30, the higher the visible light transmittance of the transparent conductor 30 can be.

[0069] When the transparent conductor 30 is formed in a mesh shape, the thickness of the transparent conductor 30 may be 1 to 40 μm. By forming the transparent conductor 30 in a mesh shape, it is possible to increase the visible light transmittance even if the transparent conductor 30 is thick. The thickness of the transparent conductor 30 is more preferably 5 μm or more, and even more preferably 8 μm or more. Furthermore, the thickness of the transparent conductor 30 is more preferably 30 μm or less, even more preferably 20 μm or less, and particularly preferably 15 μm or less.

[0070] In the transparent conductor 30, the thickness (thickness in the Z direction) of the thin metal wires 31, 32 is set smaller than the line widths (conductor widths) w31, w32 of the mesh-like thin metal wires 31, 32. This is because an aspect ratio exceeding 1 results in structural imbalance, making the structure more fragile and difficult to manufacture. However, the thicker the thin metal wires 31, 32, the lower the sheet resistance value, so in terms of antenna efficiency, it is better for the thin metal wires 31, 32 to be thicker. For this reason, it is preferable that the thickness of the thin metal wires 31, 32 be smaller than the line widths (conductor widths) w31, w32 of the thin metal wires 31, 32 and as large as possible.

[0071] The conductor materials of the metal fine wires 31 and 32 of the transparent conductor 30 include copper, but other metal materials such as silver, aluminum, chromium, nickel, gold, platinum, tin, iron, etc. can also be used, and it is not limited to these materials.

[0072] The antenna element 110, the feeding line 120, and the ground layer 130 realized by such a transparent conductor 30 are transparent, have high light transmittance that is difficult to confirm with human vision, and can function as a conductor. Further, the transparent conductor 30 constituting these metal fine wire layers has, for example, a sheet resistance of 5 Ω / sq or less, more preferably 1 Ω / sq or less, and even more preferably around 0.5 Ω / sq.

[0073] Here, as shown in FIG. 3, the first transparent substrate 101 on the upper side of the antenna device 100 is provided on the surface side of the polarizing plate 280. Therefore, the metal fine wire layer constituting the antenna element 110 and the feeding line 120 formed on the first transparent substrate 101 is suitable for blackening treatment because it is difficult to reflect visible light. In the blackening treatment, the surface of the metal fine wire is coated with a material containing copper oxide (CuO) or copper nitride (CuN). Regarding the metal fine wires of the ground layer 130, which is the metal fine wire layer of the second transparent substrate 102 provided on the inner surface side of the polarizing plate 280, the processing may not be necessary.

[0074] <Reason why the length Y30A in the Y direction is longer than the length X30A in the X direction> FIG. 7 is an exemplary diagram explaining the reason why the length Y30A in the Y direction is longer than the length X30A in the X direction. In the signal line 121, current flows in the Y direction. In other words, the signal transmission direction in the signal line 121 is the Y direction. Further, the excitation direction of the antenna element 110 is the Y direction. Also, since current flows in the Y direction in the ground layer 130, the signal transmission direction in the ground layer 130 is the Y direction.

[0075] When the length Y30A of the cell 30A in the Y direction is longer than the length X30A in the X direction, the equivalent impedance of the antenna element 110, the feed line 120, and the ground layer 130 in the Y direction is lowered, current flows more easily, and the radiation efficiency of the antenna device 100 is increased. When the radiation efficiency of the antenna device 100 is increased, the gain of the antenna device 100 is also increased. In particular, it has been found that when the length Y30A of the cell 30A in the Y direction is longer than the length X30A in the X direction in the signal line 121 of the feed line 120, the radiation efficiency of the antenna device 100 is increased, and the gain is also increased. This is thought to be because the length of the thin metal wires 31 and 32 in the Y direction is shorter in a transparent conductor 30 in which cells 30A having square openings 33 with a length X30A of 100 μm and a length Y30A of 200 μm are arranged than in a transparent conductor in which cells having square openings with lengths X30A and Y30A of 100 μm are arranged.

[0076] For this reason, in the antenna device 100, the Y-direction length Y30A of the cell 30A of the transparent conductor 30 that constitutes the antenna element 110, the feed line 120, and the ground layer 130 is set to be longer than the X-direction length X30A.

[0077] 7, the distance D1 between the end of antenna element 110 on the -Y side and the end of ground portions 122 and 123 on the +Y side is, for example, 500 μm. The distance D2 between the end of antenna element 110 on the -Y side and the end of recess 112 on the +Y side is, for example, 210 μm. Therefore, the length of signal line 121B in the Y direction is, for example, 710 μm. The distance D3 on the X side of recess 112 is, for example, 200 μm.

[0078] Furthermore, thin metal wires extend in the X and Y directions at the outer edges of the antenna element 110, the feed line 120, and the ground layer 130. In this way, at the outer edges of the antenna element 110, the feed line 120, and the ground layer 130, there may be portions where the thin metal wires are parallel to the arrangement direction of the pixels of the display panel 220. This is because, when viewed as a whole, these outer edges are only a small portion of the display panel 220.

[0079] Furthermore, since the length X30A in the X direction and the length Y30A in the Y direction of the cell 30A are different, irregularities occur in the X direction and the Y direction, and moire can be suppressed more effectively.

[0080] Furthermore, since the antenna element 110 and the feed line 120 overlap with the ground layer 130, for example, the size of the cells 30A of the transparent conductors 30 of the antenna element 110 and the feed line 120 and the size of the cells 30A of the transparent conductors 30 of the ground layer 130 are the same, and the positions of the cells 30A in the X and Y directions are the same. This is to more effectively suppress moire.

[0081] Also, as an example, the length X30A in the X direction of the cell 30A is different from the pixel pitch in the X direction of the display panel 220 (an example of a first pitch), and the length Y30A in the Y direction is different from the pixel pitch in the Y direction of the display panel 220 (an example of a second pitch). This is to more effectively suppress moiré. Also, as an example, the arrangement of the cell 30A is set so that the boundaries of the cell 30A in the X direction and the Y direction do not overlap as much as possible with the boundaries between pixels in the X direction and the Y direction of the display panel 220. This is to more effectively suppress moiré.

[0082] In addition, the ratio of the length Y30A in the Y direction to the length X30A in the X direction of the cell 30A is, for example, 2 (200 μm / 100 μm), but from the viewpoint of suppressing moiré and improving radiation efficiency, the ratio Y30A / X30A is preferably in the range of 1.2 to 5.0, and more preferably in the range of 1.5 to 3. Furthermore, the ratio Y30A / X30A is further preferably 2 or greater.

[0083] Furthermore, the ratio of the length X30A of the cell 30A in the X direction to the pixel pitch in the X direction of the display panel 220 (an example of a first pitch) is preferably within a range of 0.5 to 2.3. Furthermore, the ratio of the length Y30A of the cell 30A in the Y direction to the pixel pitch in the Y direction (an example of a second pitch) is preferably within a range of 1.2 to 4.0. Furthermore, the ratio Y30A / X30A is preferably larger than the ratio of the pixel pitch in the Y direction to the pixel pitch in the X direction of the display panel 220, and more preferably 1.5 times or more.

[0084] <Characteristics of the Antenna Device 100> Fig. 8 is a diagram showing an example of the frequency characteristic of the S11 parameter of antenna device 100. The S11 parameter shown in Fig. 8 is the ratio of power reflected back to power feeding section 111 to power input to power feeding section 111, and is obtained by electromagnetic field simulation.

[0085] As an example, when examining the value at -10 dB, it was found to be -10 dB or less in the frequency band from approximately 26.8 GHz to approximately 29.7 GHz, and it was confirmed that good radiation efficiency was obtained in the frequency band including the resonant frequency f1 (28 GHz) of the antenna device 100. This is thought to be due to the effect that the radiation efficiency of the antenna device 100 is increased and the gain is increased because the longitudinal direction of the cell 30A and the signal transmission direction in the feed line 120 and the ground layer 130 are aligned, and also the longitudinal direction of the cell 30A and the excitation direction of the antenna element 110 are aligned.

[0086] Fig. 9 is a diagram showing an example of the directivity of the antenna device 100 in the YZ plane. The directivity shown in Fig. 9 was obtained by electromagnetic field simulation. The 90 degree direction is the +Y direction, the 0 degree direction is the +Z direction, and the -90 degree direction is the -Y direction. As shown in Fig. 9, it was confirmed that uniform upward directivity was obtained in the YZ plane. It is believed that the good directivity was obtained due to the effect of increased gain resulting from increased radiation efficiency of the antenna device 100.

[0087] 10 is a diagram showing an example of the relationship between the cell shape of the transparent conductor 30 and the efficiency and peak gain. For comparison, the efficiency and peak gain were determined by electromagnetic field simulation using a transparent conductor with a square cell shape and a diamond-shaped transparent conductor elongated in the X direction. The cell shape is the opening shape of the cell.

[0088] The transparent conductor, which is composed of square cells, has a length of 100 μm in the X direction, a length of 100 μm in the Y direction, and a line width of 6 μm. The square cells have thin metal lines extending at 45 degrees to the X and Y directions. The efficiency was 59.1% and the peak gain was 3.85 dB.

[0089] For the transparent conductor consisting of cells long in the X direction, the length of the cell in the X direction was 200 μm, the length in the Y direction was 100 μm, and the line width was 6 μm. The cell long in the X direction is a cell with a configuration in which cell 30A shown in Figure 6 is rotated 90 degrees clockwise in a planar view. The efficiency was 50.5% and the peak gain was 3.04 dB, both of which were lower than those of square cells.

[0090] The transparent conductor 30 made up of the cell 30A had a length of 100 μm in the X direction, a length of 200 μm in the Y direction, and a line width of 6 μm. The efficiency was 62.8% and the peak gain was 4.03 dB, both of which were higher than those of a square cell.

[0091] <Effects> As described above, the Y-direction length Y30A of the cell 30A of the transparent conductor 30 constituting the antenna element 110, the feed line 120, and the ground layer 130 is set to be longer than the X-direction length X30A, and the signal line 121A on the -Y-direction side of the signal line 121 of the feed line 120 extends in the Y direction. This increases the radiation efficiency of the antenna device 100, thereby increasing the gain. Furthermore, by setting the Y-direction length Y30A of the cell 30A to be longer than the X-direction length X30A, moire can be suppressed.

[0092] Therefore, it is possible to provide the antenna device 100 and the electronic device 200 that are realized with a metal mesh and are capable of suppressing moire and improving antenna characteristics at the same time. In particular, in the signal line 121 of the feed line 120, the length Y30A of the cell 30A in the Y direction is made longer than the length X30A in the X direction, thereby reducing the equivalent impedance and facilitating the flow of current, thereby increasing the radiation efficiency and gain of the antenna device 100.

[0093] Furthermore, the pitch of the pixels of the display panel 220 in the X direction is different from the length X30A of the cells 30A, and the pitch of the pixels of the display panel 220 in the Y direction is different from the length Y30A of the cells 30A, so moire can be suppressed more effectively.

[0094] Furthermore, the ratio (Y30A / X30A) of the length Y30A to the length X30A of the cell 30A is preferably equal to or greater than 2. By reducing the sheet resistance in the propagation direction (Y direction) of the high-frequency current, it is possible to achieve both a reduction in loss in the feed line 120 and an improvement in antenna efficiency.

[0095] Furthermore, the ratio of the length Y30A to the length X30A (Y30A / X30A) is preferably greater than the ratio of the pitch in the Y direction to the pitch in the X direction of the pixels of the display panel 220. From the viewpoint of reducing moiré, the ratio Y30A / X30A is more preferably 1.5 times or more the ratio of the pitch in the Y direction to the pitch in the X direction of the pixels of the display panel 220.

[0096] Furthermore, the opening ratio of the metal mesh of the antenna element 110, the feed line 120, and the ground layer 130 is 80% or more, so that the antenna device 100 can be realized as being colorless and transparent and difficult to see.

[0097] Furthermore, since the mesh is diamond-shaped, it is easy to create cells 30A whose Y-direction length Y30A and X-direction length X30A are different, making it possible to provide an antenna device 100 and an electronic device 200 that can more reliably suppress moire and improve antenna characteristics at the same time.

[0098] Since the signal line 121 of the feeder line 120 extends in the Y direction from the end 121A1 to the end 121B1, current flows more easily, thereby increasing the radiation efficiency of the antenna device 100. This makes it possible to provide the antenna device 100 and the electronic device 200 with improved antenna characteristics.

[0099] Furthermore, since the excitation direction of the antenna element 110 is along the Y direction, current flows more easily through the antenna element 110, further increasing the radiation efficiency of the antenna device 100. This makes it possible to provide the antenna device 100 and the electronic device 200 with further improved antenna characteristics.

[0100] Since the antenna element 110 is a patch antenna, a monopole, or a dipole antenna, the antenna device 100 and the electronic device 200 can be provided with the antenna element 110 having a simple configuration, which can suppress moire and improve antenna characteristics at the same time.

[0101] Furthermore, since the feed line 120 is a coplanar line or a microstrip line, it is possible to provide the antenna device 100 and the electronic device 200 that can simultaneously suppress moire and improve antenna characteristics with the feed line 120 having a simple configuration.

[0102] The antenna device 100 also includes a second transparent substrate 102 provided on the −Z direction side of the first transparent substrate 101 and a ground layer 130 provided on the second transparent substrate 102, and the signal line 121B of the signal line 121 of the feed line 120 forms a microstrip line. Therefore, impedance matching with the antenna element 110 can be achieved even in the signal line 121B of the signal line 121 that is on the +Y direction side of the end edge extending in the X direction on the +Y direction side of the ground portions 122 and 123, and it is possible to provide the antenna device 100 and the electronic device 200 that can realize further improvement in antenna characteristics in addition to suppressing moiré.

[0103] Note that signal line 121 only needs to extend in the Y direction from its end on the -Y direction side at least on the side including the end on the -Y direction side. Therefore, for example, signal line 121 may be bent in the +X direction or the -X direction on the side closer to power feeding portion 111. In this case, the excitation direction of antenna element 110 may be the X direction.

[0104] Furthermore, antenna element 110 is not limited to a patch type, and may be a monopole type or a dipole type. In particular, in the case of a dipole type, signal line 121 may be bent in the +X direction or the −X direction on the side closer to power supply portion 111.

[0105] <Modification> 11A and 11B are diagrams showing an example of the configuration of cells 30MA1 and 30MA2 according to a modified example of the embodiment. The cell 30MA1 shown in Fig. 11A and the cell 30MA2 shown in Fig. 11B are cells that can be arranged on the transparent conductor 30 in place of the cell 30A shown in Fig. 6.

[0106] The cell 30MA1 shown in FIG. 11A is configured by rotating an isosceles triangle in a plan view so that three sides form angles with respect to the X-axis and Y-axis. The length X30MA1 of such cell 30MA1 in the X direction is the length between the end of cell 30MA1 on the -X direction side and the end on the +X direction side, and the length Y30MA1 is the length between the end of cell 30MA1 on the -Y direction side and the end on the +Y direction side. The ends of cell 30MA1 on the ±X direction side and ±Y direction side are located at the center of the width of the thin metal wire of cell 30MA1. The length Y30MA1 is longer than the length X30MA1.

[0107] The cell 30MA2 shown in FIG. 11B is configured such that the six sides are angled with respect to the X-axis and Y-axis by rotating a hexagon in a plan view. The length X30MA2 in the X direction of such a cell 30MA2 is the length between the end of the cell 30MA2 on the -X direction side and the end on the +X direction side, and the length Y30MA2 is the length between the end of the cell 30MA2 on the -Y direction side and the end on the +Y direction side. The ends of the cell 30MA2 on the ±X direction side and the ±Y direction side are located at the center of the width of the thin metal wire of the cell 30MA2. The length Y30MA2 is longer than the length X30MA2.

[0108] The cells 30MA1 and 30MA2 are polygonal cells other than a rhombus. Here, the isosceles triangular and hexagonal cells 30MA1 and 30MA2 are shown as examples, but the polygonal cells other than a rhombus may be pentagonal, heptagonal, or polygonal with eight or more sides, as long as the length in the Y direction is longer than the length in the X direction.

[0109] The above describes exemplary antenna devices and electronic devices of the present disclosure, but the present disclosure is not limited to the specifically disclosed embodiments, and various modifications and variations are possible without departing from the scope of the claims. [Explanation of symbols]

[0110] 30 Transparent conductor 30A, 30MA1, 30MA2 cells 31, 32 Fine metal wire 33 Opening 100 Antenna device 101 First transparent substrate (an example of a first insulating substrate) 102 Second transparent substrate (an example of a second insulating substrate) 110 Antenna Element 111 Power Supply Unit 112 recess 120 Power Supply Line 121, 121A, 121B signal line 121A1 End (an example of the first end) 121B1 End (an example of the second end) 122, 123 Ground section 130 Ground Layer 200 Electronic equipment

Claims

1. a first insulating substrate; an antenna element formed of a metal mesh and provided on a surface of the first insulating substrate; a feeder line formed of a metal mesh and provided on the surface of the first insulator substrate, the feeder line extending between a first end and a second end connected to a feed portion of the antenna element; Including, the feed line extends from the first end in the second axial direction relative to a first axis and a second axis that are included in the surface and are perpendicular to each other; the first insulating substrate is provided on a display surface side of a display device, The plurality of pixels included in the display device are arranged along the first axis direction and the second axis direction, the metal mesh of the antenna element and the feed line includes a plurality of cells each having a first length in the first axis direction and a second length in the second axis direction; an extending direction of the thin metal wires constituting the plurality of cells has an angle with respect to the first axis direction and the second axis direction; the second length is longer than the first length, An antenna device, wherein a first pitch of the plurality of pixels in the first axis direction is different from the first length, and a second pitch of the plurality of pixels in the second axis direction is different from the second length.

2. 2. The antenna device according to claim 1, wherein a ratio of the second length to the first length is in a range of 1.2 to 5.

0.

3. 2. The antenna device according to claim 1, wherein a ratio of the second length to the first length is equal to or greater than 1.5 times a ratio of the second pitch to the first pitch.

4. 2. The antenna device according to claim 1, wherein a ratio of the first length to the first pitch is in a range of 0.5 to 2.3, and a ratio of the second length to the second pitch is in a range of 1.2 to 4.

0.

5. 5. The antenna device according to claim 1, wherein the opening ratio of the metal mesh of the antenna element and the feeder line is 80% or more.

6. The antenna device according to claim 1 , wherein the cells are rhombic or polygonal other than rhombic.

7. The antenna device according to claim 1 , wherein the feed line extends along the second axis direction from the first end to the second end.

8. The antenna device according to claim 1 , wherein an excitation direction of the antenna element is along the second axis direction.

9. the antenna element is a patch antenna, a monopole, or a dipole antenna; When the antenna element is the patch antenna, a second insulating substrate provided closer to the display device than the first insulating substrate; a ground layer provided on the second insulating substrate; 9. The antenna device according to claim 1, further comprising:

10. the feed line is a coplanar line or a microstrip line, When the feed line is a microstrip line, a second insulating substrate provided closer to the display device than the first insulating substrate; a ground layer provided on the second insulating substrate; further comprising The antenna device according to claim 1 , wherein a portion of the feed line that overlaps with the ground layer constitutes the microstrip line.

11. a display device; an antenna device provided on the display surface side of the display device; An electronic device comprising: the display device is a liquid crystal display or an organic light emitting diode; The antenna device includes: a first insulating substrate; an antenna element formed of a metal mesh and provided on a surface of the first insulating substrate; a feeder line formed of a metal mesh and provided on the surface of the first insulator substrate, the feeder line extending between a first end and a second end connected to a feed portion of the antenna element; and the feed line extends from the first end in the second axial direction relative to a first axis and a second axis that are included in the surface and are perpendicular to each other; The plurality of pixels included in the display device are arranged along the first axis direction and the second axis direction, the metal mesh of the antenna element and the feed line includes a plurality of cells each having a first length in the first axis direction and a second length in the second axis direction; an extending direction of the thin metal wires constituting the plurality of cells has an angle with respect to the first axis direction and the second axis direction; the second length is longer than the first length, An electronic device, wherein a first pitch of the plurality of pixels in the first axis direction is different from the first length, and a second pitch of the plurality of pixels in the second axis direction is different from the second length.

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