Wiring board and head-mounted display

Abstract

A wiring board comprising a transparent substrate, and a mesh wiring layer that is disposed on the substrate. The wiring board has an electromagnetic wave transmission / reception function. The mesh wiring layer is configured as an electromagnetic-wave-transmitting / receiving portion and has wiring. In the planar shape of the wiring, a plurality of curved lines are connected. The curved lines are arcs or elliptic arcs.

Description

Wiring board and head-mounted display

[0001] An embodiment of the present disclosure relates to a wiring board and a head-mounted display.

[0002] Currently, mobile terminal devices such as smartphones, tablets, and smart glasses (AR, MR, etc.) are becoming more functional, smaller, thinner, and lighter. These mobile terminal devices use multiple communication bands. Therefore, multiple antennas corresponding to the communication bands are required. For example, mobile terminal devices are equipped with multiple antennas, such as a telephone antenna, a Wi-Fi (Wireless Fidelity) antenna, a 3G (Generation) antenna, a 4G (Generation) antenna, a 5G (Generation) antenna, an LTE (Long Term Evolution) antenna, a Bluetooth (registered trademark) antenna, and an NFC (Near Field Communication) antenna. However, as mobile terminal devices become smaller, the space available for antenna installation is limited, limiting the freedom of antenna design. Furthermore, because antennas are built into a limited space, radio wave sensitivity is not always satisfactory.

[0003] For this reason, a film antenna that can be mounted in the display area of ​​a mobile terminal device or the transparent area of ​​smart glasses has been developed. This film antenna is a transparent antenna in which an antenna pattern is formed on a transparent substrate. The antenna pattern is formed by a mesh-like conductive mesh layer. The conductive mesh layer includes a conductive portion as a formed portion of an opaque conductive layer and a large number of openings as a non-formed portion.

[0004] JP 2011-66610 A Japanese Patent No. 5636735 Japanese Patent No. 5695947

[0005] In conventional film antennas, a region in which a conductive mesh layer (antenna pattern) is formed exists on a transparent substrate. When the wiring of the conductive mesh layer is arranged in a regular grid pattern, light streaks (rays of light) depending on the direction of the wiring may be observed when observing a point light source. When such rays of light occur, the visibility of images on mobile terminal devices, etc., may be reduced.

[0006] One way to eliminate the beams of light is to eliminate the periodicity of the wiring. However, if the periodicity of the wiring is eliminated, the direction of the wiring will vary, which could cause flickering due to light reflection.

[0007] An object of the present embodiment is to provide a wiring board and a head-mounted display that can suppress a decrease in visibility due to light beams and also suppress flickering due to reflected light.

[0008] A first aspect of the present disclosure is a wiring board comprising a transparent substrate and a mesh wiring layer disposed on the substrate, wherein the wiring board has an electromagnetic wave transmitting and receiving function, the mesh wiring layer is configured as an electromagnetic wave transmitting and receiving unit and has wiring, the planar shape of the wiring is a shape formed by connecting multiple curves, and the curve is a circular arc or an elliptical arc.

[0009] In a second aspect of the present disclosure, in the wiring board according to the first aspect described above, the mesh wiring layer may have an aperture ratio of 94% or more.

[0010] According to a third aspect of the present disclosure, in the wiring board according to the first aspect or the second aspect described above, an opening may be formed by being surrounded by the wiring, and the shape of the wiring surrounding the opening, where ends of chords of a plurality of the curves are connected to each other, may be a polygon, and the wiring may have a shape where a plurality of arcs cut at a central angle of 160° or more and 200° or less are connected, and one side of the polygon may be composed of 2N (N is a natural number greater than or equal to 1) chords, and on the one side, of the division points obtained by dividing the side into 2N equal parts, the Mth (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) division point counting from one end of the side is defined as the Mth division point, and on the one side, of the connection points between the chords, the Mth connection point counting from the one end of the side is defined as the Mth connection point, and the distance from the Mth division point to the Mth connection point may be 0.1 / N times the length of the side.

[0011] A fourth aspect of the present disclosure is that in the wiring board according to the third aspect described above, a plurality of the openings may be formed, and the corners of the polygon may be irregularly arranged.

[0012] In a fifth aspect of the present disclosure, in the wiring board according to the first aspect described above, an opening may be formed by being surrounded by the wiring, and the shape of the wiring surrounding the opening, where ends of chords of the plurality of curves are connected together, may be a square, and the wiring may have a shape where a plurality of arcs cut at a central angle of 160° or more and 200° or less are connected, and one side of the square may be composed of 2N (N is a natural number greater than or equal to 1) chords, and on the one side, of the division points obtained by dividing the side into 2N equal parts, the Mth (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) division point, counting from one end of the side, is defined as the Mth division point, and on the one side, of the connection points between the chords, counting from the one end of the side, is defined as the Mth connection point, and the distance from the Mth division point to the Mth connection point may be 0.1 / N times or less the length of the side.

[0013] A sixth aspect of the present disclosure is directed to a wiring board according to the first aspect described above, wherein an opening is formed by being surrounded by the wiring, and the shape of the wiring surrounding the opening, where ends of chords of the plurality of curves are connected to each other, may be a square, and the wiring may have a shape where a plurality of arcs cut at a central angle of 80° or more and 100° or less are connected, and one side of the square may be composed of 2N (N is a natural number greater than or equal to 1) chords, and on the one side, of the division points obtained by dividing the side into 2N equal parts, the Mth (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) division point counting from one end of the side is defined as the Mth division point, and on the one side, of the connection points between the chords, the Mth connection point counting from the one end of the side is defined as the Mth connection point, and the distance from the Mth division point to the Mth connection point may be 0.1 / N times the length of the side.

[0014] A seventh aspect of the present disclosure is that, in a wiring board according to each of the first aspect to the fifth aspect described above, the curve may be an arc cut at a central angle of 180°, and in a wiring board according to the first aspect or the sixth aspect described above, the curve may be an arc cut at a central angle of 90°.

[0015] According to an eighth aspect of the present disclosure, in the wiring board according to the first aspect described above, an opening may be formed by being surrounded by the wiring, and the shape of the wiring surrounding the opening, where ends of chords of the plurality of curves are connected to each other, may be a rhombus, and the wiring may have a shape where ends of chords of the plurality of curves are connected to each other, and the wiring may have a shape where a plurality of arcs cut at a central angle of 160° or more and 200° or less are connected, and one side of the rhombus may be composed of 2N chords (N is a natural number greater than or equal to 1), and on the one side, of the division points obtained by dividing the side into 2N equal parts, the Mth division point (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) counting from one end of the side is defined as the Mth division point, and on the one side, of the connection points between the chords, counting from the one end of the side is defined as the Mth connection point, and the distance from the Mth division point to the Mth connection point may be 0.1 / N times or less the length of the side.

[0016] According to a ninth aspect of the present disclosure, in the wiring board according to the first aspect described above, an opening may be formed by being surrounded by the wiring, and the shape of the wiring surrounding the opening, obtained by connecting ends of chords of a plurality of the curves, may be a regular hexagon, and the wiring may have a shape obtained by connecting a plurality of arcs cut at a central angle of 160° or more and 200° or less, and one side of the regular hexagon may be composed of 2N (N is a natural number greater than or equal to 1) chords, and on the one side, of the division points obtained by dividing the side into 2N equal parts, the Mth (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) division point, counting from one end of the side, is defined as the Mth division point, and on the one side, of the connection points between the chords, counting from the one end of the side, is defined as the Mth connection point, and the distance from the Mth division point to the Mth connection point may be 0.1 / N times or less the length of the side.

[0017] A tenth aspect of the present disclosure is a wiring board according to the first aspect described above, wherein an opening is formed by being surrounded by the wiring, and the shape of the wiring surrounding the opening, where ends of chords of a plurality of the curves are connected to each other, may be a polygon, and the wiring may have a shape where a plurality of arcs cut at a central angle of 80° or more and 100° or less are connected, and one side of the polygon may be composed of 2N (N is a natural number greater than or equal to 1) chords, and on the one side, of the division points obtained by dividing the side into 2N equal parts, the Mth (M is a natural number greater than or equal to 1 and less than or equal to (2N-1)) division point counting from one end of the side is defined as the Mth division point, and on the one side, of the connection points between the chords, the Mth connection point counting from the one end of the side is defined as the Mth connection point, and the distance from the Mth division point to the Mth connection point may be 0.1 / N times the length of the side.

[0018] An eleventh aspect of the present disclosure is the wiring board according to the tenth aspect, wherein the polygon may be a rhombus or a hexagon.

[0019] A twelfth aspect of the present disclosure is the wiring board according to each of the first to eleventh aspects described above, wherein N may be 1.

[0020] A thirteenth aspect of the present disclosure is a wiring board according to each of the first to twelfth aspects described above, wherein the wiring board may have a function of transmitting and receiving radio waves at a frequency of 1 GHz or higher.

[0021] A fourteenth aspect of the present disclosure is the wiring board according to any one of the first to thirteenth aspects described above, wherein the mesh wiring layer has an electromagnetic wave shielding function.

[0022] A fifteenth aspect of the present disclosure is a wiring board according to each of the first to fourteenth aspects described above, wherein when the wiring board is bent 180° around a cylinder having a diameter of 1 mm and then stretched ten times, the increase in the resistance value of the mesh wiring layer may be 10% or less.

[0023] A sixteenth aspect of the present disclosure is that, in a wiring substrate according to each of the first aspect to the fifteenth aspect described above, a dummy wiring layer electrically independent from the mesh wiring layer may be provided around the mesh wiring layer.

[0024] A seventeenth aspect of the present disclosure is that in a wiring substrate according to each of the first aspect to the sixteenth aspect described above, a plurality of dummy wiring layers may be provided, and the aperture ratio of the mesh wiring layer and the dummy wiring layer may increase stepwise from the mesh wiring layer toward the dummy wiring layer farther from the mesh wiring layer.

[0025] An 18th aspect of the present disclosure is a head-mounted display comprising a frame and a transparent display device attached to the frame, the display device having a first substrate, a wiring board according to any one of the first to 17th aspects described above provided on the first substrate, and a display unit provided between the first substrate and the wiring board.

[0026] According to the embodiments of the present disclosure, it is possible to suppress the reduction in visibility due to light beams and also suppress flickering due to reflected light.

[0027] FIG. 1 is a perspective view showing a head-mounted display according to an embodiment. FIG. 2 is a front view (view taken in the direction of arrow II in FIG. 1 ) showing a head-mounted display according to an embodiment. FIG. 3 is a cross-sectional view (cross-sectional view taken along line III-III in FIG. 2 ) showing a display device of a head-mounted display according to an embodiment. FIG. 4 is a plan view showing a wiring board according to an embodiment. FIG. 5 is an enlarged plan view showing a mesh wiring layer of a wiring board according to an embodiment. FIG. 6 is a cross-sectional view (cross-sectional view taken along line VI-VI in FIG. 5 ) showing a wiring board according to an embodiment. FIG. 7 is a cross-sectional view (cross-sectional view taken along line VII-VII in FIG. 5 ) showing a wiring board according to an embodiment. FIG. 8A is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. FIG. 8B is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. FIG. 8C is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. FIG. 8D is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. FIG. 8E is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. FIG. 8F is a cross-sectional view showing a method for manufacturing a wiring board according to an embodiment. FIG. 9 is an enlarged plan view showing a wiring board according to a first modified example. FIG. 10A is an enlarged plan view showing a wiring board according to a second modified example. FIG. 10B is an enlarged plan view showing another example of the wiring board according to the second modified example. FIG. 11 is an enlarged plan view showing a wiring board according to a third modified example. FIG. 12A is an enlarged plan view showing a wiring board according to a fourth modified example. FIG. 12B is an enlarged plan view showing another example of the wiring board according to the fourth modified example. FIG. 13 is an enlarged plan view showing a wiring board according to a fifth modified example. FIG. 14 is an enlarged plan view showing another example of the wiring board according to the fifth modified example. FIG. 15 is an enlarged plan view showing another example of the wiring board according to the fifth modified example. FIG. 16 is a plan view showing a wiring board according to a sixth modified example. FIG. 17 is an enlarged plan view showing a wiring board according to the sixth modified example. FIG. 18 is a plan view showing a wiring board according to a seventh modified example. FIG. 19 is an enlarged plan view showing a wiring board according to the seventh modified example.

[0028] First, one embodiment will be described with reference to Figures 1 to 8F. Figures 1 to 8F are diagrams showing this embodiment.

[0029] The figures shown below are schematic diagrams. Therefore, the size and shape of each part are appropriately exaggerated for ease of understanding. Furthermore, appropriate modifications can be made within the scope of the technical concept. In the figures shown below, the same parts are denoted by the same reference numerals, and some detailed descriptions may be omitted. Furthermore, the numerical values, such as dimensions, and material names of each component described in this specification are examples of embodiments, and are not limited to these and may be selected and used as appropriate. In this specification, terms specifying shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are interpreted not only to mean their strict meanings but also to include substantially the same state.

[0030] In the following embodiments, the "X direction" refers to a direction parallel to one side of the substrate. The "Y direction" refers to a direction perpendicular to the X direction and parallel to another side of the substrate. The "Z direction" refers to a direction perpendicular to both the X and Y directions and parallel to the thickness direction of the substrate. The "front surface" refers to the surface on the positive side of the Z direction that faces the wearer. The "back surface" refers to the surface on the negative side of the Z direction that is opposite to the surface facing the wearer.

[0031] First, the configuration of a head mounted display (hereinafter simply referred to as HMD) according to this embodiment will be described with reference to Figures 1 to 3. The HMD according to this embodiment is a transmission type (see-through type) HMD.

[0032] As shown in FIG. 1 , the HMD 90 according to this embodiment includes a frame 91 and a transparent display device 95 attached to the frame 91. In this embodiment, the HMD 90 includes a display device 95 for the right eye and a display device 95 for the left eye, and is a so-called eyeglass-type HMD. The display device 95 for the right eye and the display device 95 for the left eye have substantially the same structure. The display devices 95 are synchronized with each other and are configured to display the same image on the left and right, or to display corresponding images on the left and right. Furthermore, the two display devices 95 may be individually controllable, and the two display devices 95 may display different images from each other. The HMD 90 may also be a so-called goggle-type HMD that includes a single display device 95.

[0033] A frame 91 of the HMD 90 has a rim 92 and a pair of temples 93 connected to the rim 92. Each display device 95 is fitted into the rim 92. In this embodiment, a wireless communication circuit 94a of the HMD 90 is provided on the rim 92.

[0034] Furthermore, a control unit 94b for controlling each display device 95 is provided on each of the pair of temples 93. This control unit 94b may include an image display unit (not shown) that generates image light. In this embodiment, one control unit 94b is provided on each temple 93. The control unit 94b provided on the right temple 93 controls the display device 95 for the right eye, and the control unit 94b provided on the left temple 93 controls the display device 95 for the left eye.

[0035] Next, the display device 95 will be described. As shown in Figures 2 and 3, the display device 95 has a first substrate 96, a wiring board 10 provided on the first substrate 96, and a display unit 97 provided between the first substrate 96 and the wiring board 10. In this embodiment, the wiring board 10 covers the entire first substrate 96. Although not shown, the wiring board 10 may cover only a portion of the first substrate 96.

[0036] The first substrate 96 may be made of any material that is transparent in the visible light range. For example, a glass substrate may be used as the first substrate 96. In this embodiment, when the HMD 90 is worn by a wearer, the first substrate 96 is disposed farther from the wearer, and the wiring substrate 10 is disposed closer to the wearer. That is, when the HMD 90 is worn by a wearer, the wiring substrate 10 is disposed between the first substrate 96 and the wearer. This prevents the wiring substrate 10 from coming into contact with surrounding structures or other people, for example, even if the HMD 90 comes into contact with surrounding structures or other people when worn by the wearer. This prevents the first directional wiring 21 and the second directional wiring 22 of the mesh wiring layer 20 of the wiring substrate 10, which will be described later, from being disconnected due to contact with surrounding structures or other people. Note that when the HMD 90 is worn by a wearer, the first substrate 96 may be disposed closer to the wearer, and the wiring substrate 10 may be disposed farther from the wearer.

[0037] Such a display device 95 may be a display device that projects an image using a prism or a hologram, or may be a display device that uses a transmissive liquid crystal display or the like.

[0038] The display unit 97 of the display device 95 may include a half mirror if the display device is a projection type display device. This half mirror is a component that superimposes external light in front of the display device 95 with image light from an image display unit (not shown) that generates image light. If the display device 95 is a display device using a transmissive liquid crystal display or the like, a half mirror is not necessary. Furthermore, the display unit 97 is configured so that the image display area is transparent when the image is not displayed, allowing the wearer to view the external world through the light that passes through the display unit 97. The wearer can then view a virtual image (image) formed by the image light while viewing the external world. In the illustrated example, the display unit 97 is positioned so as to overlap approximately the center of the first substrate 96 in a front view (see FIG. 2 ). However, this is not limited thereto, and the display unit 97 may be positioned so as to overlap any region of the first substrate 96 in a front view. The display unit 97 and the wiring substrate 10 may be positioned so as to overlap each other without interfering with each other, or they may be positioned so as not to overlap each other.

[0039] Next, the configuration of the wiring board will be described with reference to Figures 4 to 7. Figures 4 to 7 are diagrams showing the wiring board according to this embodiment.

[0040] The wiring board 10 according to the present embodiment is a board used in, for example, the above-described HMD 90 (see FIGS. 1 to 3). The wiring board 10 may also be used in mobile terminal devices such as smartphones and tablets.

[0041] The wiring board 10 can transmit and receive radio waves of a predetermined frequency (e.g., a frequency of 1 GHz or higher) and perform communication. The wiring board 10 may be compatible with any of a millimeter wave antenna, a telephone antenna, a Wi-Fi antenna, a 3G antenna, a 4G antenna, a 5G antenna, an LTE antenna, a Bluetooth (registered trademark) antenna, an NFC antenna, etc. Alternatively, the wiring board 10 may have functions such as a gesture sensing function, a wireless power supply function, an anti-fogging function, a heater function, a hovering function (a function that allows the user to operate the display without directly touching it), a fingerprint authentication function, and a noise reduction (electromagnetic wave shielding) function. Herein, the "gesture sensing function" refers to a function for detecting the relative position (distance, angle, etc.) of an object with respect to the mesh wiring layer 20 (described later) of the wiring board 10, or the movement speed of the object. In this case, for example, the mesh wiring layer 20 of the wiring board 10 may perform the gesture sensing function by detecting millimeter waves.

[0042] The wiring board 10 includes a transparent substrate 11 and a mesh wiring layer 20 disposed on the substrate 11. A power supply section 40 is electrically connected to the mesh wiring layer 20.

[0043] The shape of the substrate 11 is generally rectangular in plan view (a rectangle with rounded corners (see FIG. 2 )). In the illustrated example, its longitudinal direction is parallel to the X direction, and its lateral direction is parallel to the Y direction. The substrate 11 is transparent and generally flat, and its thickness is generally uniform overall. The shape of the substrate 11 can be selected as appropriate to match the shape of the first base material 96 of the display device 95 to be attached to the frame 91.

[0044] The material of the substrate 11 may be any material that is transparent in the visible light range and electrically insulating. The material of the substrate 11 is preferably an organic insulating material such as a polyester resin, an acrylic resin, a polycarbonate resin, a polyimide resin, a polyolefin resin, a cellulose resin, or a fluororesin material. The polyester resin may be polyethylene terephthalate or the like. The acrylic resin may be polymethyl methacrylate or the like. The polyolefin resin may be a cycloolefin polymer or the like. The cellulose resin may be triacetyl cellulose or the like. The fluororesin material may be PTFE, PFA or the like. For example, the material of the substrate 11 may be an organic insulating material such as a cycloolefin polymer (e.g., ZF-16 manufactured by Nippon Zeon Co., Ltd.) or a polynorbornene polymer (manufactured by Sumitomo Bakelite Co., Ltd.). Furthermore, the material of the substrate 11 may be glass, ceramics, or the like, appropriately selected depending on the application. Although the substrate 11 is illustrated as being made up of a single layer, the present invention is not limited to this and may have a structure in which multiple base materials or layers are stacked. Furthermore, the substrate 11 may be a film-like member or a plate-like member.

[0045] Furthermore, the substrate 11 is transparent. In this specification, "transparent" means that the transmittance of visible light (light having a wavelength of 400 nm or more and 700 nm or less) is 85% or more. The substrate 11 may have a transmittance of visible light (light having a wavelength of 400 nm or more and 700 nm or less) of 85% or more, preferably 90% or more. There is no particular upper limit to the visible light transmittance of the substrate 11, but it may be, for example, 100% or less. By setting the visible light transmittance of the substrate 11 within the above range, it is possible to prevent interference with visibility of the outside world when the wiring substrate 10 is incorporated into the HDM 90. Note that a visible light transmittance of 85% or more means that when the absorbance of the substrate 11 is measured using a known spectrophotometer (spectroscope: V-670 manufactured by JASCO Corporation), the transmittance is 85% or more over the entire wavelength range of 400 nm to 700 nm.

[0046] The tensile modulus of elasticity of the substrate 11 is preferably 0.5 GPa or more and 4.5 GPa or less. By making the tensile modulus of elasticity of the substrate 11 0.5 GPa or more, the rigidity of the substrate 11 can be maintained, and deformation of the substrate 11 can be suppressed. Furthermore, by making the tensile modulus of elasticity of the substrate 11 4.5 GPa or less, the substrate 11 can be prevented from becoming too hard. This prevents the substrate 11 from being damaged even when the substrate 11 is bent. Therefore, deterioration of antenna performance due to deformation of the wiring board 10 can be suppressed. The tensile modulus of elasticity of the substrate 11 can be measured in accordance with ASTM-D-882. Specifically, the elongation of a test piece is measured using a tensile tester, and the maximum elasticity immediately before plastic deformation (a linear equation of the tangent to the maximum slope of the stress-strain curve) can be obtained.

[0047] The dielectric loss tangent of the substrate 11 may be 0.002 or less, and preferably 0.001 or less. There is no particular lower limit to the dielectric loss tangent of the substrate 11, but it may be greater than 0. When the dielectric loss tangent of the substrate 11 is in the above range, particularly when the electromagnetic waves (e.g., millimeter waves) transmitted and received by the mesh wiring layer 20 are high frequency, the gain loss (i.e., reduction in sensitivity) associated with the transmission and reception of electromagnetic waves can be reduced.

[0048] The dielectric constant of the substrate 11 is preferably 2 or more and 10 or less. Having a dielectric constant of 2 or more for the substrate 11 increases the options for materials for the substrate 11. Having a dielectric constant of 2 or more for the substrate 11 also allows for the selection of inexpensive materials, thereby reducing manufacturing costs. Having a dielectric constant of 2 or more for the substrate 11 also allows for the selection of materials suitable for the manufacturing process, thereby improving manufacturing yield and reducing manufacturing costs. Having a dielectric constant of 10 or less for the substrate 11 reduces the loss of gain (sensitivity) associated with the transmission and reception of electromagnetic waves. That is, if the dielectric constant of the substrate 11 increases, the thickness of the substrate 11 has a greater effect on the propagation of electromagnetic waves. Furthermore, if there is an adverse effect on the propagation of electromagnetic waves, the dielectric loss tangent of the substrate 11 increases, which can increase the loss of gain associated with the transmission and reception of electromagnetic waves. On the other hand, having a dielectric constant of 10 or less for the substrate 11 reduces the effect of the thickness of the substrate 11 on the propagation of electromagnetic waves. Therefore, the loss of gain associated with the transmission and reception of electromagnetic waves can be reduced. In particular, when the electromagnetic waves (for example, millimeter waves) transmitted and received by the mesh wiring layer 20 are high frequency waves, the loss of gain associated with the transmission and reception of the electromagnetic waves can be reduced.

[0049] The dielectric loss tangent and relative dielectric constant of the substrate 11 can be measured in accordance with IEC 62562. Specifically, first, a test piece is prepared by cutting out a portion of the substrate 11 where the mesh wiring layer 20 is not formed. The dimensions of the test piece are a width of 10 mm to 20 mm and a length of 50 mm to 100 mm. Next, the dielectric loss tangent or relative dielectric constant is measured in accordance with IEC 62562.

[0050] In this embodiment, the mesh wiring layer 20 is configured as a transmitter / receiver of electromagnetic waves. In other words, the mesh wiring layer 20 is made up of an antenna pattern that functions as an antenna. This mesh wiring layer 20 may be configured as an array antenna including two or more antenna elements (radiating elements (tip portion 20b described later)). In this way, when the mesh wiring layer 20 is configured as an array antenna, it is possible to improve the millimeter wave antenna performance for transmitting and receiving millimeter waves with high linearity. Note that an array antenna is an antenna in which multiple antenna elements are regularly arranged and in which the amplitude and phase of the excitation of the elements can be independently controlled.

[0051] As shown in FIG. 4, a plurality of mesh wiring layers 20 are formed on the substrate 11. It is preferable that four or more mesh wiring layers 20 are provided. In this case, four or more antenna elements (tip side portions 20b described later) are provided on the wiring substrate 10. In the illustrated example, four mesh wiring layers 20 are formed on the substrate 11 (see FIG. 2). Also, as shown in FIG. 4, the mesh wiring layer 20 may not be present on the entire surface of the substrate 11, but may be present only in a partial region on the substrate 11. Each mesh wiring layer 20 may have the same shape. In this case, each mesh wiring layer 20 has a length (length in the Y direction) L of the tip side portion 20b described later. ａ Error and width (length in the X direction) W ａ It is preferable that the errors of the above are within 10%. This can effectively improve the performance of the millimeter wave antenna.

[0052] The mesh wiring layer 20 has a base end portion (transmission portion) 20a on the power supply unit 40 side and a tip end portion (transmission / reception portion) 20b connected to the base end portion 20a. The base end portion 20a is connected to the power supply unit 40. In this case, the base end portion (transmission portion) 20a may be configured as a microstrip line or a coplanar line. The base end portion 20a and the tip end portion 20b each have a substantially rectangular shape in a plan view. In this case, the width (distance in the X direction) of the tip end portion 20b is wider than the width (distance in the X direction) of the base end portion 20a.

[0053] The tip end portion 20b of the mesh wiring layer 20 corresponds to a predetermined frequency band. That is, the tip end portion 20b has a length (length in the Y direction) L ａ The length L of the distal end portion 20b corresponds to a specific frequency band. ａ The length of the mesh wiring layer 20 becomes longer. In addition to a millimeter wave antenna, the mesh wiring layer 20 may be compatible with any of a telephone antenna, a Wi-Fi antenna, a 3G antenna, a 4G antenna, a 5G antenna, an LTE antenna, a Bluetooth (registered trademark) antenna, an NFC antenna, etc. Note that the lengths of the plurality of tip side portions 20b may be different from each other, and each may correspond to a different frequency band. Alternatively, each mesh wiring layer 20 may perform functions such as a hovering function, fingerprint authentication, a heater, noise reduction (electromagnetic wave shielding), etc.

[0054] In the illustrated example, the tip portion 20b has a longitudinal direction parallel to the X direction and a lateral direction parallel to the Y direction. Alternatively, the tip portion 20b may have a longitudinal direction parallel to the Y direction and a lateral direction parallel to the X direction. The length L of the tip portion 20b in the Y direction ａ The width W of the tip portion 20b in the X direction can be selected, for example, in the range of 1 mm to 100 mm. ａ In particular, when the mesh wiring layer 20 is a millimeter wave antenna, the length L of the tip side portion 20b can be selected within a range of, for example, 1 mm or more and 100 mm or less. ａ When the mesh wiring layer 20 is a millimeter wave antenna, the length L of the tip side portion 20b can be selected in the range of 1 mm or more, more preferably 1.5 mm or more. ａ can be selected in the range of 10 mm or less, more preferably 5 mm or less.

[0055] The distance between the mesh wiring layers 20 can be set appropriately depending on the corresponding frequency, but is preferably 1 mm or more and 30 mm or less. ２０ｂ (See FIG. 4) is preferably 1 mm or more and 30 mm or less. By setting an appropriate distance, desired antenna directivity and gain improvement can be obtained.

[0056] 4, the mesh wiring layer 20 has a pattern shape in which metal wires are arranged in a mesh shape. This pattern shape is repeatedly arranged in the X direction and the Y direction. That is, the mesh wiring layer 20 has a pattern shape composed of a portion (first-directional wiring 21 described later) extending in a first direction (e.g., Y direction) and a portion (second-directional wiring 22 described later) extending in a second direction (e.g., X direction).

[0057] As shown in FIG. 5 , the mesh wiring layer 20 has wiring. Specifically, the mesh wiring layer 20 has a plurality of first-directional wirings (wirings) 21 and a plurality of second-directional wirings (wirings) 22 connecting the plurality of first-directional wirings 21. The plurality of first-directional wirings 21 and the plurality of second-directional wirings 22 are integrated as a whole to form a mesh-like shape. Each first-directional wiring 21 extends in the longitudinal direction (Y direction) of the mesh wiring layer 20. Each second-directional wiring extends in the width direction (X direction) of the mesh wiring layer 20. Note that the first-directional wirings 21 and the second-directional wirings 22 may extend in a direction that is not parallel to either the X direction or the Y direction.

[0058] The planar shape of the first directional wiring 21 and the second directional wiring 22 is a shape formed by connecting multiple curves. In this case, the curves are circular arcs or elliptical arcs. In the illustrated example, the planar shape of the first directional wiring 21 and the second directional wiring 22 is a shape formed by connecting multiple arcs. Here, a diffraction image generated due to a linear structure extends in a direction perpendicular to the longitudinal direction of the structure and becomes a light beam (a streak of light observed to trail). On the other hand, when the planar shape of the first directional wiring 21 and the second directional wiring 22 is a shape formed by connecting multiple arcs, the generated light beams extend in various directions. When the generated light beams extend in various directions, the light beams overlap each other, making it difficult to distinguish each light beam. This reduces the impact of the light beams on visibility. Note that when the curves are elliptical arcs, the length of the major axis of the ellipse formed by the elliptical arcs may be more than 1 time and not more than 1.1 times the length of the minor axis.

[0059] In the mesh wiring layer 20, openings 23 are formed by being surrounded by first directional wires 21 and second directional wires 22. Specifically, in the mesh wiring layer 20, a plurality of openings 23 are formed by being surrounded by adjacent first directional wires 21 and adjacent second directional wires 22. The transparent substrate 11 is exposed from each opening 23. This allows the transparency of the wiring substrate 10 as a whole to be increased.

[0060] In the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23, the shape formed by connecting the ends of the chords of a plurality of arcs (curves) is a polygon. In this case, one side of the polygon may be made up of 2N (N is a natural number equal to or greater than 1) chords. In this embodiment, one side of the polygon is made up of two (N=1) chords. Also, in this embodiment, the shape formed by connecting the ends of the chords of a plurality of arcs (curves) in the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23 is a square. That is, the straight line L1 connecting the ends of the chords of the first directional wiring 21 and the straight line L2 connecting the ends of the chords of the second directional wiring 22 are arranged at equal intervals. The straight lines L1 connecting the ends of the chords of the first directional wiring 21 are arranged at equal intervals, and the pitch P １ The pitch P can be set to, for example, a range of 0.01 mm to 1 mm. The straight lines L2 connecting the ends of the chords of the second directional wirings 22 are arranged at equal intervals, and the pitch P ２ can be, for example, in the range of 0.01 mm to 1 mm. This eliminates variation in the size of the openings 23 within the mesh wiring layer 20, making the mesh wiring layer 20 difficult to see with the naked eye. Note that although the lines L1 and L2 are perpendicular to each other, this is not a limitation and they may intersect at an acute or obtuse angle. Furthermore, the shape of the openings 23 is preferably the same shape and size over the entire surface, but it does not have to be uniform over the entire surface, and may vary depending on the location. Furthermore, although not shown, one side of the polygon may be composed of four or more chords (N≧2), or may be composed of an odd number of chords.

[0061] Here, the first directional wiring 21 and the second directional wiring 22 may have a shape in which a plurality of arcs cut at a central angle of 160° to 200° are connected. In this case, the diameter of the circle from which the arcs are cut may be 0.4 to 0.6 times the length of one side of the square S1 formed by the straight lines L1 and L2. In this specification, the square S1 formed by the straight lines L1 and L2 refers to the square with the smallest area (see the shaded area in FIG. 5 ) among the regions (squares) surrounded by the straight lines L1 and L2.

[0062] Also, on one side of the square (polygon) S1, among the division points obtained by dividing the side into 2N equal parts, the end E １ , E ２ One end E of １ The Mth division point (M is a natural number between 1 and (2N-1)) counting from the beginning is defined as the Mth division point. １ The Mth connection point counting from the first is defined as the Mth connection point. In this case, the distance from the Mth division point to the Mth connection point may be 0.1 / N times or less the length of one side.

[0063] In this embodiment, as described above, one side of a polygon is made up of two chords, and N = 1. Therefore, the division point on one side into 2N is one end E of the side. １ The first division point DiP is the first division point (M=1) counting from １ In this embodiment, the first division point DiP １ is the midpoint of one side. Also, on one side, the connection point between the chords is one end E of the side. １ The first connection point CP is the first connection point (M=1) counting from １ Only.

[0064] In this way, when N=1 and M=1, the first division point DiP １ to the first connection point CP １ The shortest distance to ｐ１may be 0.1 times (N=1) or less the length of one side. When the first directional wiring 21 and the second directional wiring 22 have a shape in which arcs that satisfy the above relationship are connected, a nearly perfect circle can be formed by connecting the first directional wiring 21 and the second directional wiring 22 that surround the opening 23. The imaginary line in FIG. 5 is a curve connecting two arcs, and the first connection point CP １ is the midpoint of one side (the first division point DiP １ ) is the curve when

[0065] In this embodiment, as shown in Fig. 5, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ1 of 180° are connected. In this case, the diameter of the circle C1 from which the arcs are cut is 0.5 times the length of one side of the square S1 formed by the straight lines L1 and L2. Also, on one side of the square S1 formed by the straight lines L1 and L2, the first connection point CP １ is the first division point DiP １ The second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ2 of 180° are connected. In this case, the diameter of the circle C2 from which the arcs are cut is 0.5 times the length of one side of the square S1 formed by the straight lines L1 and L2. The first connection point CP is located on one side of the square S1 formed by the straight lines L1 and L2. １ is the first division point DiP １ (midpoint of one side). In this case, a complete circle can be formed by connecting, for example, the second directional wirings 22, 22a that form the upper straight line L1 among the first directional wirings 21 and the second directional wirings 22 that surround the opening 23 (see the shaded portion in FIG. 5 ). Here, a complete circle means a circle formed without overlapping arcs when curves are connected. Also, in this case, multiple complete circles can be formed by connecting the first directional wirings 21 and the second directional wirings 22 that surround the opening 23 (see the shaded portion in FIG. 5 ). Note that in this specification, the opening 23 refers to the area surrounded by the first directional wirings 21 and the second directional wirings 22 that has the smallest area (see the shaded portion in FIG. 5 ).

[0066] As described above, the diffraction image generated by the linear structure extends in a direction perpendicular to the longitudinal direction of the structure and becomes a beam of light (a streak of light observed to have a trailing tail). On the other hand, if the generated beam of light extends in all directions (360°), it becomes difficult to distinguish each beam of light. In other words, by overlapping a large number of beams of light in a circular shape, the effect of the beams of light on visibility can be reduced. Therefore, in order for the beams of light to extend in all directions and, as a result, overlap each other and be visible as a circle, it is sufficient that the normals perpendicular to the longitudinal direction of the first directional wiring 21 and the second directional wiring 22 surrounding one opening 23 are distributed in all directions.

[0067] In contrast to this, in this embodiment, the first directional wiring 21 and the second directional wiring 22 may have a shape in which a plurality of arcs cut at a central angle of 160° or more and 200° or less are connected. １ to the first connection point CP １ The shortest distance to ｐ１ can be 0.1 times or less the length of one side. As a result, the normals orthogonal to the longitudinal direction of the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23 (see the shaded area in FIG. 5 ) can be distributed in almost all directions. Therefore, it is possible to more effectively suppress the decrease in visibility due to the light beams. In particular, when the first directional wiring 21 and the second directional wiring 22 have a shape in which a plurality of arcs are connected, which are obtained by cutting circles C1 and C2, each having a diameter 0.5 times the length of one side of a square S1 formed by the straight lines L1 and L2, at central angles θ1 and θ2 of 180°, and when the first connection point CP １ is the first division point DiP １ When the normal is located on the midpoint of one side, the normal is distributed in all directions, which makes it possible to more effectively prevent the deterioration of visibility due to the light beams.

[0068] As shown in FIG. 6 , each first directional wiring 21 has a cross section perpendicular to its longitudinal direction that is substantially rectangular or square. In this case, the cross-sectional shape of the first directional wiring 21 is substantially uniform along the longitudinal direction of the first directional wiring 21. As shown in FIG. 7 , each second directional wiring 22 has a cross section perpendicular to its longitudinal direction that is substantially rectangular or square, and has substantially the same shape as the cross-sectional shape of the first directional wiring 21 described above. In this case, the cross-sectional shape of the second directional wiring 22 is substantially uniform along the longitudinal direction of the second directional wiring 22. The cross-sectional shapes of the first directional wiring 21 and the second directional wiring 22 do not necessarily have to be substantially rectangular or square. For example, the cross-sectional shapes of the first directional wiring 21 and the second directional wiring 22 may be substantially trapezoidal, with the front side (positive side in the Z direction) narrower than the back side (negative side in the Z direction), or may have curved side surfaces on both widthwise sides.

[0069] In this embodiment, the line width W of the first direction wiring 21 １ (see FIG. 6) and the line width W ２ (See FIG. 7) is not particularly limited and can be appropriately selected depending on the application. １ is the width in a cross section perpendicular to the longitudinal direction, and the line width W of the second directional wiring 22 ２ is the width in a cross section perpendicular to the longitudinal direction. For example, the line width W of the first directional wiring 21 １ The width W of the second direction wiring 22 can be selected in the range of 0.1 μm to 5.0 μm, and may be set to 0.2 μm to 2.0 μm. ２ can be selected from the range of 0.1 μm to 5.0 μm, and may be set to 0.2 μm to 2.0 μm.

[0070] Height H of the first directional wiring 21 １ (See FIG. 6) and the height H ２ (See FIG. 7) is not particularly limited and can be appropriately selected depending on the application. １ and the height H of the second direction wiring 22 ２ are the lengths in the Z direction. １ and the height H of the second direction wiring 22 ２The height H of the first directional wiring 21 can be selected within a range of, for example, 0.1 μm or more, and may be 0.2 μm or more. １ and the height H of the second direction wiring 22 ２ can be selected, for example, in the range of 5.0 μm or less, and may be 2.0 μm or less.

[0071] The material of the first directional wiring 21 and the second directional wiring 22 may be any conductive metal material. In the present embodiment, the material of the first directional wiring 21 and the second directional wiring 22 is copper, but is not limited to this. The material of the first directional wiring 21 and the second directional wiring 22 may be, for example, a metal material such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or an alloy containing these metals. Furthermore, the first directional wiring 21 and the second directional wiring 22 may be a plating layer formed by electrolytic plating.

[0072] The overall aperture ratio At of the mesh wiring layer 20 may be, for example, in the range of 87% or more and less than 100%. By setting the overall aperture ratio At of the mesh wiring layer 20 in this range, the conductivity and transparency of the wiring substrate 10 can be ensured. The overall aperture ratio At of the mesh wiring layer 20 is preferably 94% or more and less than 100%. This allows the transparency of the wiring substrate 10 to be increased while ensuring the conductivity of the wiring substrate 10. The aperture ratio refers to the ratio (%) of the area of ​​the open region to the unit area of ​​a predetermined region (e.g., the entire mesh wiring layer 20). The open region refers to a region where no metal parts such as the first directional wiring 21 and the second directional wiring 22 are present and the substrate 11 is exposed.

[0073] Although not shown, a protective layer may be formed on the first surface 11a of the substrate 11 so as to cover the mesh wiring layer 20. The protective layer protects the mesh wiring layer 20 and is formed so as to cover at least the mesh wiring layer 20 of the substrate 11. Examples of materials that can be used for the protective layer include acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate, modified resins thereof, copolymers thereof, polyvinyl resins such as polyester, polyvinyl alcohol, polyvinyl acetate, polyvinyl acetal, and polyvinyl butyral, copolymers thereof, polyurethane, epoxy resin, polyamide, and chlorinated polyolefin, and other colorless and transparent insulating resins.

[0074] Furthermore, when a bending resistance test is performed on the wiring substrate 10, the increase in the resistance value of the mesh wiring layer 20 may be 10% or less, or may be 5% or less. The bending resistance test is a test in which, using a cylindrical mandrel bending tester, the wiring substrate 10 is bent 180° around the circumference of a cylinder with a diameter of 1 mm and then straightened 100 times.

[0075] Specifically, the test is carried out as follows: First, the electrical resistance value between both ends of the mesh wiring layer 20 in the longitudinal direction is measured. The resistance value at this time is defined as R ０ (Ω). Next, the wiring substrate 10 is wound around the cylinder of a cylindrical mandrel bending tester so that both ends of the wiring substrate 10 in the longitudinal direction are oriented in opposite directions by 180°. Thereafter, the wiring substrate 10 is removed from the cylinder and flattened out. This process is repeated 100 times. Thereafter, the electrical resistance value between both ends of the mesh wiring layer 20 in the longitudinal direction is measured again. The resistance value at this time is defined as R １ (Ω). In this case, ((R １ -R ０ ) / R ０ ) × 100(%) is the increase in resistance value. When the increase in resistance value is 10% or less, the durability of the wiring substrate 10 can be improved when the wiring substrate 10 is used while being curved or bent.

[0076] 4 again, a power supply section 40 is electrically connected to the mesh wiring layer 20. The power supply section 40 is made of a substantially rectangular conductive thin plate member.

[0077] The power supply unit 40 is disposed at the longitudinal end (the end on the negative Y-side) of the substrate 11. The power supply unit 40 may be made of a metal such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or an alloy containing any of these metals.

[0078] When the wiring substrate 10 is incorporated into the HDM 90 (see FIG. 2 ), the power supply unit 40 is electrically connected to a wireless communication circuit 94a provided on a frame 91 of the HMD 90. Here, the power supply unit 40 is preferably provided in a position overlapping a rim 92 of the frame 91 in a front view of the HMD 90. This further facilitates connection between the mesh wiring layer 20 and the wireless communication circuit 94a and prevents interference with visibility of the outside world. Note that, although the power supply unit 40 is provided on the first surface 11a of the substrate 11, this is not a limitation, and part or all of the power supply unit 40 may be located outside the periphery of the substrate 11.

[0079] [Method of Manufacturing Wiring Board] Next, a method of manufacturing wiring board 10 according to this embodiment will be described with reference to FIGS. 8A to 8F.

[0080] 8A, a substrate 11 is prepared, which includes a first surface 11a and a second surface 11b located on the opposite side of the first surface 11a. The substrate 11 is transparent.

[0081] Next, the mesh wiring layer 20 and the power supply section 40 electrically connected to the mesh wiring layer 20 are formed on the first surface 11 a of the substrate 11 .

[0082] 8B , metal foil 51 is first laminated over substantially the entire first surface 11a of substrate 11. In this embodiment, the thickness of metal foil 51 may be 0.1 μm or more and 5.0 μm or less. In this embodiment, metal foil 51 may contain copper.

[0083] 8C, a photo-curable insulating resist 52 is applied to almost the entire surface of the metal foil 51. As the photo-curable insulating resist 52, for example, an organic resin such as an acrylic resin or an epoxy resin can be used.

[0084] 8D , the insulating layer 54 is formed by photolithography. In this case, the photo-curable insulating resist 52 is patterned by photolithography to form the insulating layer 54 (resist pattern). At this time, the insulating layer 54 is formed so that the metal foil 51 corresponding to the first-directional wiring 21 and the second-directional wiring 22 is exposed.

[0085] 8E , the metal foil 51 located on the first surface 11 a of the substrate 11 in the portion not covered with the insulating layer 54 is removed. At this time, the metal foil 51 is etched so as to expose the first surface 11 a of the substrate 11 by wet processing using ferric chloride, cupric chloride, a strong acid such as sulfuric acid or hydrochloric acid, persulfate, hydrogen peroxide, an aqueous solution of these, or a combination of these.

[0086] 8F, the insulating layer 54 is removed by wet treatment using a permanganate solution, N-methyl-2-pyrrolidone, an acid or alkaline solution, or dry treatment using oxygen plasma.

[0087] In this manner, the wiring substrate 10 is obtained, which includes the substrate 11 and the mesh wiring layer 20 provided on the first surface 11a of the substrate 11. In this case, the mesh wiring layer 20 includes first directional wiring 21 and second directional wiring 22. At this time, the power supply unit 40 may be formed by a part of the metal foil. Alternatively, a flat power supply unit 40 may be separately prepared and electrically connected to the mesh wiring layer 20.

[0088] 1 is obtained by attaching the wiring board 10 to the first substrate 96 that is fitted into the rim 92 of the frame 91. Note that the wiring board 10 may be attached to the first substrate 96 before the first substrate 96 is fitted into the rim 92 of the frame 91.

[0089] [Operation of the Present Embodiment] Next, the operation of the present embodiment configured as described above will be described.

[0090] 2, the wiring board 10 is incorporated into the HMD 90 as a component of the display device 95. The mesh wiring layer 20 of the wiring board 10 is electrically connected to a wireless communication circuit 94a of the HMD 90 via the power supply unit 40. In this way, radio waves of a predetermined frequency can be transmitted and received via the mesh wiring layer 20, and communication can be performed using the HMD 90.

[0091] According to this embodiment, the planar shape of the first directional wiring 21 and the second directional wiring 22 is a shape formed by connecting a plurality of arcs. This causes the generated light beams to extend in various directions. Therefore, the light beams overlap each other, making them difficult to distinguish. As a result, a decrease in visibility due to the light beams can be suppressed. Furthermore, in this case, a decrease in visibility due to the light beams can be suppressed without increasing the variation in the pitch of the first directional wiring 21 and the second directional wiring 22 and the variation in the pitch of the second directional wiring 22. Therefore, flickering caused by reflection of visible light by the mesh wiring layer 20 can be suppressed. Furthermore, since the planar shape of the first directional wiring 21 and the second directional wiring 22 is a shape formed by connecting a plurality of arcs, reflection of electromagnetic waves from the first directional wiring 21 and the second directional wiring 22 can be reduced. This increases the transmission efficiency of the wiring board 10.

[0092] Furthermore, according to this embodiment, in the HMD 90, the wiring substrate 10 includes a transparent substrate 11 and a mesh wiring layer 20 disposed on the substrate 11. The mesh wiring layer 20 has an aperture ratio of 94% or more. This ensures the transparency of the wiring substrate 10. As a result, when the wiring substrate 10 is incorporated into the HMD 90, the outside world can be viewed through the openings 23 of the mesh wiring layer 20, and visibility of the outside world is not obstructed.

[0093] Next, modified examples of the wiring board will be described.

[0094] Fig. 9 shows a first modified example of the wiring board 10. The modified example shown in Fig. 9 differs in that the first directional wiring 21 and the second directional wiring 22 have a shape formed by connecting a plurality of arcs cut at a central angle of 80° or more and 100° or less, but the other configurations are substantially the same as those of the embodiment shown in Figs. 1 to 8F described above. In Fig. 9, the same parts as those of the embodiment shown in Figs. 1 to 8F are designated by the same reference numerals, and detailed description thereof will be omitted.

[0095] 9, the first directional wiring 21 and the second directional wiring 22 have a shape in which a plurality of arcs cut at a central angle of 80° or more and 100° or less are connected. In this case, the diameter of the circle from which the arcs are cut may be (1 / √2)×0.8 times or more and (1 / √2)×1.2 times or less the length of one side of the square S1 formed by the straight lines L1 and L2. Also in this modification, the first division point DiP １ to the first connection point CP １ The shortest distance to ｐ１ (See FIG. 5 ) may be 0.1 times or less the length of one side. Even when the first directional wiring 21 and the second directional wiring 22 have a shape formed by connecting arcs that satisfy the above relationship, a nearly perfect circle can be formed by connecting the first directional wiring 21 and the second directional wiring 22 that surround the opening 23.

[0096] In this modification, as shown in Fig. 9, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ3 of 90° are connected. In this case, the diameter of a circle C3 from which the arcs are cut is 1 / √2 times the length of one side of the square S1 formed by the straight lines L1 and L2. Also, on one side of the square S1 formed by the straight lines L1 and L2, the first connection point CP １ is the first division point DiP １The second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ4 of 90° are connected. In this case, the diameter of the circle C4 from which the arcs are cut is 1 / √2 times the length of one side of the square S1 formed by the straight lines L1 and L2. The first connection point CP is located on one side of the square S1 formed by the straight lines L1 and L2. １ is the first division point DiP １ (midpoint of one side). Even in this case, by connecting the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23, multiple complete circles can be formed. Even in this case, the influence of the light beams on visibility can be reduced by overlapping the multiple light beams in a circular shape. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed.

[0097] In this modification, the first directional wiring 21 has a shape formed by connecting multiple arcs cut at a central angle θ3 of 80° to 100°, and the second directional wiring 22 has a shape formed by connecting multiple arcs cut at a central angle θ4 of 80° to 100°. In this case, the difference between the line length of the shape (polygon) formed by connecting the ends of multiple curved chords in the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23 and the total line length of the first directional wiring 21 and the second directional wiring 22 can be reduced. In other words, compared to when the central angles θ3 and θ4 are, for example, 180°, the central angles θ3 and θ4 being 80° to 100° can reduce the rate of increase in the total line length of the first directional wiring 21 and the second directional wiring 22 relative to the polygon. This can suppress an increase in the resistance value of the mesh wiring layer 20.

[0098] Furthermore, since the rate of increase in the line length can be reduced, a decrease in the aperture ratio of the mesh wiring layer 20 can be suppressed. Furthermore, since the rate of increase in the line length can be reduced, the line lengths of the first directional wiring 21 and the second directional wiring 22 can be prevented from becoming too long. Therefore, the risk of breakage of the first directional wiring 21 and the second directional wiring 22 can also be reduced. Furthermore, since the line lengths of the first directional wiring 21, etc. and the second directional wiring 22 can be prevented from becoming too long, the patterning accuracy when manufacturing the first directional wiring 21 and the second directional wiring 22 and the dimensional stability of the first directional wiring 21 and the second directional wiring 22 can be improved. Therefore, the productivity of the wiring substrate 10 can be improved.

[0099] Fig. 10A shows a second modified example of the wiring board 10. The modified example shown in Fig. 10A differs in that the shape of the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23, where the ends of the chords of a plurality of curves are connected to each other, is a rhombus, but the other configuration is substantially the same as the embodiment shown in Figs. 1 to 9 described above. In Fig. 10A, the same parts as those shown in Figs. 1 to 9 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0100] In the wiring board 10 shown in Figure 10A, the shape of the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23, where the ends of the chords of the multiple curves are connected, is a rhombus. In other words, the polygon described above is a rhombus. In this case, the first directional wiring 21 and the second directional wiring 22 extend in directions non-parallel to both the X direction and the Y direction, respectively. This reduces the resistance in the Y direction, through which current flows. This improves the antenna characteristics.

[0101] Furthermore, the first directional wiring 21 and the second directional wiring 22 have a shape in which a plurality of arcs cut at a central angle of 160° to 200° are connected. In this case, the diameter of the circle from which the arcs are cut may be 0.4 to 0.6 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. Also, as shown by the imaginary line (two-dot chain line) in FIG. 10A, the first division point DiP １ to the first connection point CP １ The shortest distance toｐ２ may be 0.1 times or less the length of one side. Even when the first directional wiring 21 and the second directional wiring 22 have a shape formed by connecting arcs that satisfy the above relationship, a nearly perfect circle can be formed by connecting the first directional wiring 21 and the second directional wiring 22 that surround the opening 23. The imaginary line in FIG. 10A is a curve connecting two arcs, and the first connection point CP １ is the midpoint of one side (the first division point DiP １ ) is the curve when

[0102] In this modification, as shown in Fig. 10A, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ5 of 180° are connected. In this case, the diameter of the circle C5 from which the arcs are cut is 0.5 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. Also, on one side of the rhombus S2 formed by the straight lines L1 and L2, the first connection point CP １ is the first division point DiP １ The second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ6 of 180° are connected. In this case, the diameter of the circle C6 from which the arcs are cut is 0.5 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. The first connection point CP is located on one side of the rhombus S2 formed by the straight lines L1 and L2. １ is the first division point DiP １ (midpoint of one side). Even in this case, by connecting the first directional wiring 21 and the second directional wiring 22 surrounding the opening 23, multiple complete circles can be formed. Even in this case, the influence of the light beams on visibility can be reduced by overlapping the multiple light beams in a circular shape. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed.

[0103] 10A has been described as an example in which the first directional wiring 21 and the second directional wiring 22 have a shape in which a plurality of arcs cut at a central angle of 160° to 200° are connected, but this is not limiting. For example, the first directional wiring 21 and the second directional wiring 22 may have a shape in which a plurality of arcs cut at a central angle of 80° to 100° are connected. Even in this case, the diameter of the circle from which the arcs are cut may be 0.4 to 0.6 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. Furthermore, as shown by the virtual line (two-dot chain line) in FIG. 10B, the first division point DiP １ to the first connection point CP １ The shortest distance to ｐ２ The virtual line in FIG. 10B is a curve connecting two circular arcs, and the first connection point CP １ is the midpoint of one side (the first division point DiP １ ) is the curve when

[0104] In this modification, as shown in FIG. 10B , the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ5 of 90° are connected. In this case, too, the diameter of the circle C5 from which the arcs are cut is 0.5 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. Also, on one side of the rhombus S2 formed by the straight lines L1 and L2, the first connection point CP １ is the first division point DiP １ The second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ6 of 90° are connected. In this case, too, the diameter of the circle C6 from which the arcs are cut is 0.5 times the length of one side of the rhombus S2 formed by the straight lines L1 and L2. The first connection point CP is located on one side of the rhombus S2 formed by the straight lines L1 and L2. １ is the first division point DiP １ (midpoint of one side) is located above.

[0105] In the example shown in FIG. 10B , multiple complete circles can be formed by connecting the first directional wirings 21 and the second directional wirings 22 surrounding the opening 23. In this case, the overlapping of multiple light beams in a circular shape reduces the impact of the light beams on visibility. This more effectively suppresses the reduction in visibility due to the light beams. Also in the example shown in FIG. 10B , the rate of increase in the total line length of the first directional wirings 21 and the second directional wirings 22 relative to the polygon described above can be reduced, thereby suppressing an increase in the resistance value of the mesh wiring layer 20. Furthermore, since the rate of increase in the line length can be reduced, a decrease in the aperture ratio of the mesh wiring layer 20 can be suppressed. Also in the example shown in FIG. 10B , the line lengths of the first directional wirings 21 and the second directional wirings 22 can be prevented from becoming too long, thereby reducing the risk of disconnection of the first directional wirings 21 and the second directional wirings 22. Furthermore, it is possible to improve the patterning accuracy when fabricating the first directional wiring 21 and the second directional wiring 22, and the dimensional stability of the first directional wiring 21 and the second directional wiring 22. Therefore, it is possible to improve the productivity of the wiring substrate 10.

[0106] Figure 11 shows a third modified example of the wiring board 10. The modified example shown in Figure 11 differs in that one side of the diamond S2 is composed of four (N=2) chords, but the other configuration is substantially the same as the embodiment shown in Figures 1 to 10B described above. In Figure 11, the same parts as those shown in Figures 1 to 10B are designated by the same reference numerals, and detailed description thereof will be omitted.

[0107] 11, one side of the diamond S2 is made up of four chords (N=2). Therefore, the division point on one side that divides the side into four (N=2) is the first division point DiP １ , second dividing point DiP ２ and the third division point DiP ３ Among these, the second division point DiP ２ is the midpoint of one side. Also, on one side, the connection point between the chords is the first connection point CP １ , second connection point CP ２ and the third connection point CP ３ There are three of them.

[0108] In this modification, as shown by the imaginary line (two-dot chain line) in FIG. 11, a first division point DiP １ to the first connection point CP １ The shortest distance to ｐ３ may be 0.05 times the length of one side (N=2) or less. ２ From the second connection point CP ２ The shortest distance to ｐ４ may be equal to or less than 0.05 times the length of one side (N=2). ３ From the third connection point CP ３ The shortest distance to ｐ５ may be 0.05 times the length of one side (N=2) or less. Even when the first directional wiring 21 and the second directional wiring 22 have a shape formed by connecting arcs that satisfy the above relationship, a nearly perfect circle can be formed by connecting the first directional wiring 21 and the second directional wiring 22 that surround the opening 23. The imaginary line in FIG. 11 is a curved line connecting four arcs, and the first connection point CP １ is the first division point DiP １ Instead, the second connection point CP ２ is the second division point DiP ２ Instead, the third connection point CP ３ is the third division point DiP ３ This is the curve when it is not.

[0109] As shown in Figure 11, the diameter of the circles C5 and C6 from which the arcs are cut is 0.25 times the length of one side of the rhombus S2. １ is the first division point DiP １ Located above, the second connection point CP ２ is the second division point DiP ２ (midpoint of one side) and the third connection point CP ３ is the third division point DiP ３ It is located above.

[0110] In this modification, as shown in FIG. 11, a first division point DiP is set on one side of a rhombus S2. １ to the first connection point CP １The shortest distance to ｐ３ is equal to or less than 0.05 times the length of one side (N=2). ２ From the second connection point CP ２ The shortest distance to ｐ４ is equal to or less than 0.05 times the length of one side (N=2). ３ From the third connection point CP ３ The shortest distance to ｐ５ is 0.05 times the length of one side (N=2) or less. Even in this case, by connecting the first directional wirings 21 and the second directional wirings 22 surrounding the opening 23, multiple complete circles can be formed. Even in this case, the influence of the light beams on visibility can be reduced by overlapping the multiple light beams in a circular shape. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed.

[0111] Fig. 12A shows a fourth modified example of the wiring board 10. The modified example shown in Fig. 12A differs in that the shape formed by connecting the ends of the chords of a plurality of curves in the first directional wiring 21, second directional wiring 22, and third directional wiring 24 surrounding the opening 23 is a regular hexagon, but the other configurations are substantially the same as those shown in Figs. 1 to 11 described above. In Fig. 12A, the same parts as those shown in Figs. 1 to 11 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0112] In the wiring board 10 shown in FIG. 12A , the shape of the first directional wiring 21, the second directional wiring 22, and the third directional wiring (wiring) 24 surrounding the opening 23, with the ends of the chords of multiple curves connected together, is a regular hexagon. In other words, the polygon described above is a regular hexagon. In this case, the first directional wiring 21 and the second directional wiring 22 extend in directions non-parallel to both the X direction and the Y direction, respectively. On the other hand, the third directional wiring 24 extends in the X direction. This reduces the resistance in the Y direction, through which current flows. This improves the antenna characteristics. Furthermore, since the third directional wiring 24 connects the first directional wiring 21 and the second directional wiring 22, breaks in the mesh wiring layer 20 can be effectively suppressed. Note that the third directional wiring 24 may extend in a direction non-parallel to either the X direction or the Y direction. The line width and height of the third directional wiring 24 and the material constituting the third directional wiring 24 may be the same as those of the first directional wiring 21 .

[0113] Furthermore, the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 have a shape in which a plurality of arcs cut at a central angle of 160° to 200° are connected. In this case, the diameter of the circle from which the arcs are cut may be 0.4 to 0.6 times the length of one side of the regular hexagon S3 formed by the lines L1, L2, and L3. Furthermore, as shown by the virtual line (two-dot chain line) in FIG. 12A , the first division point DiP １ to the first connection point CP １ The shortest distance to ｐ６ may be 0.1 times (N=1) or less the length of one side. Even when the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 have a shape formed by connecting arcs that satisfy the above relationship, a nearly perfect circle can be formed by connecting the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 that surround the opening 23. The virtual line in FIG. 12A is a curve connecting two arcs, and the first connection point CP １ is the midpoint of one side (the first division point DiP １ ) is the curve when

[0114] In this modification, as shown in Fig. 12A, the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ7 of 180° are connected. In this case, the diameter of a circle C7 from which the arcs are cut is 0.5 times the length of one side of a regular hexagon S3 formed by the straight lines L1, L2, and L3. Also, on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3, a first connection point CP １ is the first division point DiP １ The second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ8 of 180° are connected. In this case, the diameter of the circle C8 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. The first connection point CP is located on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. １ is the first division point DiP １ The third directional wiring 24 has a shape in which a plurality of arcs cut at a central angle θ9 of 180° are connected. In this case, the diameter of the circle C9 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. The first connection point CP is located on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. １ is the first division point DiP １ (midpoint of one side). Even in this case, by connecting the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 surrounding the opening 23, multiple complete circles can be formed. Even in this case, the influence of the light beams on visibility can be reduced by overlapping the multiple light beams in a circular shape. Therefore, the decrease in visibility due to the light beams can be more effectively suppressed.

[0115] In this modification, the shape (polygon) formed by connecting the ends of multiple curved chords of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 surrounding the opening 23 is a regular hexagon. In this case, a maximum of three wires (the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24) connect to the vertices of the polygon. Furthermore, the angle formed by the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 at the vertices of the polygon is 120°, which is larger than when the polygon is a square. Therefore, the patterning accuracy when fabricating the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 near the vertices of the polygon and the dimensional stability of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 can be improved. This improves the productivity of the wiring substrate 10.

[0116] 12A has been described as an example in which the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 have shapes formed by connecting multiple arcs cut at a central angle of 160° to 200°, but this is not limiting. For example, the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 may have shapes formed by connecting multiple arcs cut at a central angle of 80° to 100°. Even in this case, the diameter of the circle from which the arcs are cut may be 0.4 to 0.6 times the length of one side of the regular hexagon S3 formed by the lines L1, L2, and L3. Furthermore, as shown by the virtual line (two-dot chain line) in FIG. 12B, the first division point DiP １ to the first connection point CP １ The shortest distance to ｐ６ The virtual line in FIG. 12B is a curve connecting two circular arcs, and the first connection point CP １ is the midpoint of one side (the first division point DiP １ ) is the curve when

[0117] In this modification, as shown in FIG. 12B , the first directional wiring 21 has a shape in which a plurality of arcs cut at a central angle θ7 of 90° are connected. In this case, too, the diameter of the circle C7 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. Also, on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3, the first connection point CP １ is the first division point DiP １ The second directional wiring 22 has a shape in which a plurality of arcs cut at a central angle θ8 of 90° are connected. In this case, too, the diameter of the circle C8 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. The first connection point CP is located on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. １ is the first division point DiP １ The third directional wiring 24 has a shape in which a plurality of arcs cut at a central angle θ9 of 90° are connected. In this case, too, the diameter of the circle C9 from which the arcs are cut is 0.5 times the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. The first connection point CP is located on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. １ is the first division point DiP １ (midpoint of one side) is located above.

[0118] In the example shown in FIG. 12B , multiple complete circles can be formed by connecting the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 surrounding the opening 23. In this case, the overlapping of multiple light beams in a circular shape reduces the impact of the light beams on visibility. This more effectively suppresses the reduction in visibility due to the light beams. Also in the example shown in FIG. 12B , the rate of increase in the total line length of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 relative to the polygon described above can be reduced, thereby suppressing an increase in the resistance value of the mesh wiring layer 20. Furthermore, since the rate of increase in the line length can be reduced, a decrease in the aperture ratio of the mesh wiring layer 20 can be suppressed. Also in the example shown in FIG. 12B , the line lengths of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24 can be prevented from becoming too long, thereby reducing the risk of breakage of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24. Furthermore, it is possible to improve the patterning accuracy when fabricating the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24, and the dimensional stability of the first directional wiring 21, the second directional wiring 22, and the third directional wiring 24. As a result, it is possible to improve the productivity of the wiring substrate 10.

[0119] Fig. 13 shows a fifth modified example of the wiring board. The modified example shown in Fig. 13 differs in that the corners of the polygon are irregularly arranged, but other configurations are substantially the same as the embodiment shown in Figs. 1 to 12B described above. In Fig. 13, the same parts as those shown in Figs. 1 to 12B are designated by the same reference numerals, and detailed description thereof will be omitted.

[0120] 13, the corners of the polygon S4 formed by the straight lines L1 and L2 are irregularly arranged. That is, the straight line L1 connecting the ends of the chords of the first directional wirings 21 and the straight line L2 connecting the ends of the chords of the second directional wirings 22 are irregularly arranged relative to each other. Specifically, the straight lines L1 are arranged parallel to each other, and the pitch P １ Similarly, the straight lines L2 are arranged parallel to each other, and the pitch P ２ In this way, the pitch P of the straight line L1 １ and the pitch P of the straight line L2２ By making the wirings 21 and 22 irregular, it is possible to suppress the deterioration of visibility due to the light beams. Also in this case, by connecting the first directional wirings 21 and the second directional wirings 22 surrounding the opening 23, it is possible to form a plurality of complete circles. Also in this case, by overlapping the many light beams with each other in a circular shape, it is possible to reduce the effect of the light beams on visibility. Therefore, it is possible to more effectively suppress the deterioration of visibility due to the light beams.

[0121] As shown in FIG. 14 , the polygon S5 formed by the straight lines L1 and L2 may be a quadrangle whose opposing sides are not parallel. In this case, the curved chords may extend in a bent linear fashion. In other words, the connected chords may extend in non-parallel directions. As shown in FIG. 15 , in the mesh wiring (wiring) 200 surrounding the opening 23, the shape formed by connecting the ends of the chords of multiple arcs (curves) may be a polygon S6, and the planar structure formed by the polygon S6 may be a Voronoi pattern. The line width and height of the mesh wiring 200, as well as the material constituting the mesh wiring 200, may be the same as those of the first directional wiring 21.

[0122] Figures 16 and 17 show a sixth modified example of the wiring board. The modified example shown in Figures 16 and 17 differs in that a dummy wiring layer 30 is provided around the mesh wiring layer 20, but other configurations are substantially the same as the embodiment shown in Figures 1 to 15 described above. In Figures 16 and 17, the same parts as those shown in Figures 1 to 15 are given the same reference numerals and detailed description thereof will be omitted.

[0123] 16, a dummy wiring layer 30 is provided along the periphery of the mesh wiring layer 20. Unlike the mesh wiring layer 20, this dummy wiring layer 30 does not substantially function as an antenna.

[0124] 17, the dummy wiring layer 30 is composed of repeated dummy wirings 30a having a predetermined pattern shape. That is, the dummy wiring layer 30 includes a plurality of dummy wirings 30a, and each dummy wiring 30a is electrically independent from the mesh wiring layer 20 (the first directional wirings 21 and the second directional wirings 22). The plurality of dummy wirings 30a are regularly arranged throughout the dummy wiring layer 30. The plurality of dummy wirings 30a are spaced apart from each other in the planar direction and are arranged to protrude above the substrate 11. That is, each dummy wiring 30a is electrically independent from the mesh wiring layer 20, the power supply section 40, and the other dummy wirings 30a.

[0125] In this case, the dummy wiring 30a has a shape in which a portion of the pattern shape of the mesh wiring layer 20 described above is missing. This makes it difficult to visually recognize the difference between the mesh wiring layer 20 and the dummy wiring layer 30, and makes the mesh wiring layer 20 arranged on the substrate 11 less visible. As shown in FIG. 17 , the dummy wiring 30a includes a first portion 31a obtained by cutting out a portion of the first directional wiring 21 and a second portion 32a obtained by cutting out a portion of the second directional wiring 22. In this way, since the dummy wiring 30a is composed of a portion of the first directional wiring 21 or the second directional wiring 22 that is cut out, the mesh wiring layer 20 arranged on the substrate 11 can be made even less visible. The aperture ratio of the dummy wiring layer 30 may be the same as or different from the aperture ratio of the mesh wiring layer 20, but is preferably close to the aperture ratio of the mesh wiring layer 20. Therefore, within the region of the dummy wiring layer 30, copper wiring having the same shape as the missing portion may be arranged at any position so that the dummy wirings 30a are not connected to each other. In this case, copper wiring having the same area as the missing portion in plan view may be placed at any position within the region of the dummy wiring layer 30 so that the dummy wirings 30a are not connected to each other.

[0126] As in this modified example, the dummy wiring layer 30 that is electrically independent from the mesh wiring layer 20 is provided around the mesh wiring layer 20, thereby making it possible to obscure the outer edge of the mesh wiring layer 20. This makes it possible to make the mesh wiring layer 20 less visible on the surface of the HMD 90, and makes it difficult for a user of the HMD 90 to recognize the mesh wiring layer 20 with the naked eye.

[0127] Figures 18 and 19 show a seventh modified example of the wiring board. The modified example shown in Figures 18 and 19 differs in that a plurality of dummy wiring layers 30A, 30B having different aperture ratios are provided around the mesh wiring layer 20, but other configurations are substantially the same as those shown in Figures 1 to 17 described above. In Figures 18 and 19, the same parts as those shown in Figures 1 to 17 are given the same reference numerals, and detailed description thereof will be omitted.

[0128] 18, a plurality of (two in this case) dummy wiring layers 30A, 30B (a first dummy wiring layer 30A and a second dummy wiring layer 30B) having different aperture ratios are provided along the periphery of the mesh wiring layer 20. Specifically, the first dummy wiring layer 30A is arranged along the periphery of the mesh wiring layer 20, and the second dummy wiring layer 30B is arranged along the periphery of the first dummy wiring layer 30A. Unlike the mesh wiring layer 20, these dummy wiring layers 30A, 30B do not actually function as antennas.

[0129] As shown in FIG. 19 , the first dummy wiring layer 30A is composed of repeated dummy wirings 30a1 each having a predetermined pattern. The second dummy wiring layer 30B is composed of repeated dummy wirings 30a2 each having a predetermined pattern. That is, the dummy wiring layers 30A and 30B each include a plurality of dummy wirings 30a1 and 30a2, and each of the dummy wirings 30a1 and 30a2 is electrically independent from the mesh wiring layer 20. The dummy wirings 30a1 and 30a2 are regularly arranged throughout the dummy wiring layers 30A and 30B, respectively. The dummy wirings 30a1 and 30a2 are spaced apart from each other in the planar direction and protrude above the substrate 11. Each of the dummy wirings 30a1 and 30a2 is electrically independent from the mesh wiring layer 20, the power supply section 40, and the other dummy wirings 30a1 and 30a2.

[0130] In this case, the dummy wirings 30a1 and 30a2 have a shape in which a portion of the pattern shape of the mesh wiring layer 20 described above is missing. This makes it difficult to visually recognize the difference between the mesh wiring layer 20 and the first dummy wiring layer 30A, and the difference between the first dummy wiring layer 30A and the second dummy wiring layer 30B, and makes it difficult to see the mesh wiring layer 20 arranged on the substrate 11. As shown in FIG. 19 , the dummy wiring 30a1 includes a first portion 31a1 having a shape in which a portion of the first directional wiring 21 is cut out, and a second portion 32a1 having a shape in which a portion of the second directional wiring 22 is cut out. The dummy wiring 30a2 includes a first portion 31a2 having a portion of the first directional wiring 21 cut out, and a second portion 32a2 having a portion of the second directional wiring 22 cut out.

[0131] The area of ​​each dummy wiring 30a1 in the first dummy wiring layer 30A is larger than the area of ​​each dummy wiring 30a2 in the second dummy wiring layer 30B. In this case, the line width of each dummy wiring 30a1 is the same as the line width of each dummy wiring 30a2, but this is not limiting, and the line width of each dummy wiring 30a1 may be wider than the line width of each dummy wiring 30a2.

[0132] In this modification, the aperture ratios of the mesh wiring layer 20 and the multiple dummy wiring layers 30A, 30B preferably increase stepwise from the mesh wiring layer 20 toward the dummy wiring layers 30A, 30B farther from the mesh wiring layer 20. In other words, the aperture ratios of the dummy wiring layers preferably increase gradually from those closer to the mesh wiring layer 20 to those farther from the mesh wiring layer 20. In this case, the aperture ratio of the first dummy wiring layer 30A is preferably greater than that of the mesh wiring layer 20. The aperture ratio of the second dummy wiring layer 30B is preferably greater than that of the first dummy wiring layer 30A. This makes it possible to further obscure the outer edges of the mesh wiring layer 20 and the dummy wiring layers 30A, 30B. This makes it possible to make the mesh wiring layer 20 even less visible on the surface of the HMD 90.

[0133] In this way, by arranging the dummy wiring layers 30A and 30B electrically independent from the mesh wiring layer 20, the outer edge of the mesh wiring layer 20 can be made more unclear. This makes the mesh wiring layer 20 less visible on the surface of the HMD 90, making it difficult for a user of the HMD 90 to recognize the mesh wiring layer 20 with the naked eye. Note that three or more dummy wiring layers with different aperture ratios may be provided around the mesh wiring layer 20.

[0134] The components disclosed in the above-described embodiment and each modification may be combined as needed, or some components may be omitted from all the components shown in the above-described embodiment and each modification.

Claims

1. A wiring board, A transparent substrate; a mesh wiring layer disposed on the substrate; The wiring board has an electromagnetic wave transmitting and receiving function, The mesh wiring layer is configured as a transmission / reception unit for electromagnetic waves, and has wiring. The planar shape of the wiring is a shape in which a plurality of curved lines are connected, the curve is a circular arc or an elliptical arc, An opening is formed by being surrounded by the wiring, the wiring surrounding the opening has a shape formed by connecting ends of chords of the plurality of curves to each other, the shape being a polygon; Each side of the polygon is composed of 2N chords (N is a natural number equal to or greater than 1), Among the division points obtained by dividing the side into 2N equal parts, an Mth division point (M is a natural number between 1 and (2N-1)) counting from one end of the side is designated as an Mth division point, Among the connection points between the strings on the one side, when the Mth connection point counting from the one end of the one side is defined as the Mth connection point, A wiring board, wherein a distance from the Mth division point to the Mth connection point is equal to or less than 0.1 / N times the length of the one side.

2. The wiring board according to claim 1 , wherein the mesh wiring layer has an aperture ratio of 94% or more.

3. The wiring board described in claim 1, wherein the wiring has a shape formed by connecting multiple arcs cut at a central angle of 160° or more and 200° or less.

4. A wiring board as described in claim 2, wherein the wiring has a shape formed by connecting multiple arcs cut at a central angle of 160° or more and 200° or less.

5. A plurality of the openings are formed, The wiring board according to claim 3 , wherein corners of the polygon are irregularly arranged.

6. In the wiring surrounding the opening, a shape obtained by connecting ends of chords of the plurality of curves to each other is a square, 2. The wiring board according to claim 1, wherein the wiring has a shape in which a plurality of circular arcs cut at a central angle of 160 degrees or more and 200 degrees or less are connected.

7. In the wiring surrounding the opening, a shape obtained by connecting ends of chords of the plurality of curves to each other is a square, 2. The wiring board according to claim 1, wherein the wiring has a shape in which a plurality of circular arcs cut at a central angle of 80 degrees or more and 100 degrees or less are connected.

8. The wiring board according to claim 1 , wherein the curve is a circular arc cut at a central angle of 90° or 180°.

9. In the wiring surrounding the opening, a shape obtained by connecting ends of chords of the plurality of curves to each other is a rhombus, 2. The wiring board according to claim 1, wherein the wiring has a shape in which a plurality of circular arcs cut at a central angle of 160 degrees or more and 200 degrees or less are connected.

10. In the wiring surrounding the opening, a shape obtained by connecting ends of chords of the plurality of curves to each other is a regular hexagon, 2. The wiring board according to claim 1, wherein the wiring has a shape in which a plurality of circular arcs cut at a central angle of 160 degrees or more and 200 degrees or less are connected.

11. The wiring board described in claim 1, wherein the wiring has a shape formed by connecting multiple arcs cut at a central angle of 80° or more and 100° or less.

12. The wiring board according to claim 11 , wherein the polygon is a rhombus or a hexagon.

13. 12. The wiring board according to claim 3, wherein N is 1.

14. The wiring board according to claim 1 , wherein the wiring board has a function of transmitting and receiving radio waves at a frequency of 1 GHz or more.

15. The wiring board according to claim 1 , wherein the mesh wiring layer has an electromagnetic wave shielding function.

16. 2. The wiring board according to claim 1, wherein when the wiring board is bent 180 degrees around a cylinder having a diameter of 1 mm and then straightened 10 times, the increase in resistance value of the mesh wiring layer is 10% or less.

17. 2. The wiring board according to claim 1, further comprising a dummy wiring layer disposed around said mesh wiring layer and electrically independent from said mesh wiring layer.

18. 18. The wiring board according to claim 17, wherein a plurality of the dummy wiring layers are provided, and the aperture ratios of the mesh wiring layer and the dummy wiring layer are gradually increased from the mesh wiring layer to the dummy wiring layer farther from the mesh wiring layer.

19. A frame, a transparent display attached to the frame; The display device includes: A first substrate; The wiring board according to claim 1 provided on the first base material; a display unit provided between the first base material and the wiring board.