Wiring board and head mounted display

Abstract

To provide a wiring board and a head mounted display that suppress the deterioration of visibility due to light beams and suppress flickering due to reflected light.SOLUTION: A wiring board 10 used in a mobile terminal device, such as a head mounted display, smartphone, or tablet, includes a transparent board 11 and a mesh wiring layer 20 disposed on the board 11. The wiring board 10 has an electromagnetic wave transmitting and receiving function. The mesh wiring layer 20 is configured as a transmitting and receiving section for electromagnetic waves, and has wiring. The planar shape of the wiring is a shape in which multiple curves are connected. The curves are circular or elliptical arcs.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a wiring board and a head-mounted display.

Background Art

[0002] Currently, high functionality, miniaturization, thinning, and weight reduction of portable terminal devices such as smartphones, tablets, smart glasses (AR, MR, etc.) are progressing. These portable terminal devices use multiple communication bands. For this reason, a plurality of antennas corresponding to the communication bands are required. For example, portable terminal devices are equipped with a plurality of antennas such as a telephone antenna, a WiFi (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, with the miniaturization of portable terminal devices, the mounting space for antennas is limited, and the degree of freedom in antenna design is narrowing. In addition, since the antenna is built in a limited space, the radio wave sensitivity is not always satisfactory.

[0003] For this reason, film antennas that can be mounted in the display area of a portable terminal device or the transparent area of smart glasses have been developed. This film antenna is a transparent antenna in which an antenna pattern is formed on a transparent base material. The antenna pattern is formed by a mesh-shaped conductor mesh layer. The conductor mesh layer includes a conductor part as a forming part of an opaque conductor layer and a large number of openings as non-forming parts.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] Incidentally, in a conventional film antenna, there is a region where a conductor mesh layer (antenna pattern) is formed on a transparent substrate. And when the wiring of the conductor mesh layer is arranged regularly and in a grid pattern, when observing a point light source, there is a possibility that streaks of light (glints) depending on the direction of the wiring are observed. Thus, when glints occur, there is a risk that the visibility of an image will deteriorate in a mobile terminal device or the like.

[0006] In order to eliminate the glints, it is also conceivable to eliminate the periodicity of the wiring. However, when the periodicity of the wiring is eliminated, the directions of the wiring become various, and there is a risk of flicker due to light reflection.

[0007] One object of the present embodiment is to provide a wiring substrate and a head-mounted display capable of suppressing a decrease in visibility due to glints and suppressing flicker due to reflected light. [Disclosure of the Invention]

[0008] A first aspect of the present disclosure includes a substrate having transparency and a mesh wiring layer disposed on the substrate. The wiring substrate has an electromagnetic wave transmission / reception function, the mesh wiring layer is configured as an electromagnetic wave transmission / reception unit and has wiring, and a planar shape of the wiring is a shape connecting a plurality of curves, and the curves are arcs or elliptical arcs.

[0009] A second aspect of the present disclosure is the wiring substrate according to the first aspect described above, wherein an aperture ratio of the mesh wiring layer may be 94% or more.

[0010] The third aspect of the present disclosure is in the wiring board according to the above-described first aspect or the above-described second aspect. An opening may be formed by being surrounded by the wiring. In the wiring surrounding the opening, the shape connecting the ends of the chords of the plurality of curves may be a polygon. The wiring may have a shape formed by connecting a plurality of arcs cut out with a central angle of 160° or more and 200° or less. One side of the polygon may be composed of 2N (N is a natural number of 1 or more) chords. On one side, among the division points obtained by dividing the one side into 2N equal parts, the Mth (M is a natural number of 1 or more and (2N - 1) or less) division point counted from one end of the one side is defined as the Mth division point. On one side, when the Mth connection point counted from one end of the one side among the connection points of the chords is defined as the Mth connection point, the distance from the Mth division point to the Mth connection point may be 0.1 / N times or less of the length of the one side.

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

[0012] The fifth aspect of the present disclosure is in the wiring board according to the above-described first aspect. An opening may be formed by being surrounded by the wiring. In the wiring surrounding the opening, the shape connecting the ends of the chords of the plurality of curves may be a square. The wiring may have a shape formed by connecting a plurality of arcs cut out with a central angle of 160° or more and 200° or less. One side of the square may be composed of 2N (N is a natural number of 1 or more) chords. On one side, among the division points obtained by dividing the one side into 2N equal parts, the Mth (M is a natural number of 1 or more and (2N - 1) or less) division point counted from one end of the one side is defined as the Mth division point. On one side, when the Mth connection point counted from one end of the one side among the connection points of the chords is defined as the Mth connection point, the distance from the Mth division point to the Mth connection point may be 0.1 / N times or less of the length of the one side.

[0013] The sixth aspect of the present disclosure is in the wiring board according to the first aspect described above. An opening may be formed by being surrounded by the wiring. In the wiring surrounding the opening, the shape connecting the ends of the chords of the plurality of curves may be a square. The wiring may have a shape formed by connecting a plurality of arcs cut out with a central angle of 80° or more and 100° or less. One side of the square may be composed of 2N (N is a natural number of 1 or more) chords. On one side, among the division points that divide the one side into 2N equal parts, the M-th (M is a natural number of 1 or more and (2N - 1) or less) division point counted from one end of the one side is defined as the M-th division point. On one side, among the connection points of the chords, when the M-th connection point counted from one end of the one side is defined as the M-th connection point, the distance from the M-th division point to the M-th connection point may be 0.1 / N times or less the length of the one side.

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

[0015] The eighth aspect of the present disclosure is in the wiring board according to the first aspect described above. An opening may be formed by being surrounded by the wiring. In the wiring surrounding the opening, the shape connecting the ends of the chords of the plurality of curves may be a rhombus. The wiring may have a shape formed by connecting a plurality of arcs cut out with a central angle of 160° or more and 200° or less. One side of the rhombus may be composed of 2N (N is a natural number of 1 or more) chords. On one side, among the division points that divide the one side into 2N equal parts, the M-th (M is a natural number of 1 or more and (2N - 1) or less) division point counted from one end of the one side is defined as the M-th division point. On one side, among the connection points of the chords, when the M-th connection point counted from one end of the one side is defined as the M-th connection point, the distance from the M-th division point to the M-th connection point may be 0.1 / N times or less the length of the one side.

[0016] A ninth aspect of the present disclosure is the wiring board according to the first aspect described above. An opening may be formed by being surrounded by the wiring. In the wiring surrounding the opening, the shape formed by connecting the ends of the chords of the plurality of curves may be a regular hexagon. The wiring may have a shape formed by connecting a plurality of arcs cut out with a central angle of 160° or more and 200° or less. One side of the regular hexagon may be composed of 2N (N is a natural number of 1 or more) chords. On one side, among the division points that divide the side into 2N equal parts, the Mth (M is a natural number of 1 or more and (2N - 1) or less) division point counted from one end of the side is defined as the Mth division point. On one side, among the connection points of the chords, when the Mth connection point counted from one end of the side is defined as the Mth connection point, the distance from the Mth division point to the Mth connection point may be 0.1 / N times or less of the length of the side.

[0017] A tenth aspect of the present disclosure is the wiring board according to the first aspect described above. An opening may be formed by being surrounded by the wiring. In the wiring surrounding the opening, the shape formed by connecting the ends of the chords of the plurality of curves may be a polygon. The wiring may have a shape formed by connecting a plurality of arcs cut out with a central angle of 80° or more and 100° or less. One side of the polygon may be composed of 2N (N is a natural number of 1 or more) chords. On one side, among the division points that divide the side into 2N equal parts, the Mth (M is a natural number of 1 or more and (2N - 1) or less) division point counted from one end of the side is defined as the Mth division point. On one side, among the connection points of the chords, when the Mth connection point counted from one end of the side is defined as the Mth connection point, the distance from the Mth division point to the Mth connection point may be 0.1 / N times or less of the length of the side.

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

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

[0020] In the thirteenth aspect of the present disclosure, in the wiring board according to each of the first aspect to the twelfth aspect described above, the wiring board may have a radio wave transmission and reception function at a frequency of 1 GHz or higher.

[0021] In the fourteenth aspect of the present disclosure, in the wiring board according to each of the first aspect to the thirteenth aspect described above, the mesh wiring layer may have an electromagnetic wave shielding function.

[0022] In the fifteenth aspect of the present disclosure, in the wiring board according to each of the first aspect to the fourteenth aspect described above, when the operation of bending the wiring board 180° along the circumference of a cylinder with a diameter of 1 mm and then stretching it is performed 10 times, the increase amount of the resistance value of the mesh wiring layer may be 10% or less.

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

[0024] In the seventeenth aspect of the present disclosure, in the wiring board according to each of the first aspect to the sixteenth aspect described above, a plurality of the dummy wiring layers may be provided, and the aperture ratios of the mesh wiring layer and the dummy wiring layer may gradually increase from the mesh wiring layer toward the dummy wiring layer farther from the mesh wiring layer.

[0025] The eighteenth aspect of the present disclosure includes a frame and a transparent display device attached to the frame, and the display device is a head-mounted display having a first base material, a wiring board according to any one of the first aspect to the seventeenth aspect described above provided on the first base material, and a display portion provided between the first base material and the wiring board.

[0026] According to an embodiment of the present disclosure, it is possible to suppress a decrease in visibility due to glare and suppress flicker due to reflected light.

Brief Description of the Drawings

[0027]

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

[0029] The figures shown below are schematic figures. Therefore, the size and shape of each part are exaggerated as appropriate for easy understanding. Also, it can be implemented with appropriate changes within the scope that does not deviate from the technical idea. In each of the figures shown below, the same parts are denoted by the same reference numerals, and some detailed explanations may be omitted. Also, the numerical values such as the dimensions of each member described in this specification and the material names are examples as embodiments, and are not limited thereto, and can be appropriately selected and used. In this specification, terms specifying shapes and geometric conditions, such as terms like parallel, orthogonal, and perpendicular, are to be interpreted to include not only the strictly meant state but also substantially the same state.

[0030] Also, in the following embodiments, the "X direction" is a direction parallel to one side of the substrate. The "Y direction" is a direction perpendicular to the X direction and parallel to the other side of the substrate. The "Z direction" is a direction perpendicular to both the X direction and the Y direction and parallel to the thickness direction of the substrate. The "surface" is the surface on the positive side of the Z direction and faces the wearer side. The "back surface" is the surface on the negative side of the Z direction and is the side opposite to the surface facing the wearer side.

[0031] First, with reference to FIGS. 1 to 3, the configuration of a head-mounted display (hereinafter simply referred to as HMD) according to this embodiment will be described. The HMD according to this embodiment is a transmissive (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 glasses-type HMD. Note that the display device 95 for the right eye and the display device 95 for the left eye have substantially the same structure as each other. Further, the display devices 95 are synchronized with each other and are configured to display the same image on the left and right, or are configured 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. Note that the HMD 90 may be a so-called goggle-type HMD including a single display device 95.

[0033] The 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, respectively. In this embodiment, a wireless communication circuit 94a of the HMD 90 is provided on the rim 92.

[0034] In addition, a control unit 94b for controlling each display device 95 is provided on the pair of temples 93. This control unit 94b may include a video display unit (not shown) that generates video light. In this embodiment, one control unit 94b is arranged on each temple 93. Then, the control unit 94b arranged on the right temple 93 is configured to control the display device 95 for the right eye, and the control unit 94b arranged on the left temple 93 is configured to control the display device 95 for the left eye.

[0035] Next, the display device 95 will be described. As shown in FIGS. 2 and 3, the display device 95 includes a first base material 96, a wiring board 10 provided on the first base material 96, and a display unit 97 provided between the first base material 96 and the wiring board 10. In this embodiment, the wiring board 10 covers the entire area of the first base material 96. Note that although not shown, the wiring board 10 may cover only a part of the first base material 96.

[0036] As the material of the first base material 96, any material having transparency in the visible light region may be used. As the first base material 96, for example, a glass base material can be used. In the present embodiment, when the HMD 90 is worn by the wearer, the first base material 96 is disposed on the side farther from the wearer, and the wiring board 10 is disposed on the side closer to the wearer. That is, when the HMD 90 is worn by the wearer, the wiring board 10 is disposed between the first base material 96 and the wearer. Thereby, for example, when the wearer wears the HMD 90, even if the HMD 90 contacts a surrounding structure or another person, it is possible to suppress the wiring board 10 from contacting the surrounding structure or the like. For this reason, it is possible to suppress the first-direction wiring 21 and the second-direction wiring 22 of the mesh wiring layer 20, which will be described later, of the wiring board 10 from being disconnected due to contact with a surrounding structure or the like. Note that when the HMD 90 is worn by the wearer, the first base material 96 may be disposed on the side closer to the wearer, and the wiring board 10 may be disposed on the side farther from the wearer.

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

[0038] When the display unit 97 of the display device 95 is a display device that projects an image, it may include a half mirror. This half mirror is a member that superimposes external light in front of the display device and image light from an image display unit (not shown) that generates video light. When the display device 95 is a display device using a transmissive liquid crystal display or the like, the half mirror is unnecessary. Further, the display unit 97 is configured such that the display area of the image becomes transparent when the image is not displayed, and the wearer can visually recognize the outside world by the light passing through the display unit 97. Then, the wearer can visually recognize a virtual image (image) formed by the video light while visually recognizing the outside world. In the illustrated example, the display unit 97 is provided at a position overlapping the substantially central portion of the first base material 96 in a front view (see FIG. 2). However, the present invention is not limited to this, and the display unit 97 may be provided at a position overlapping any region of the first base material 96 in a front view. The display unit 97 and the wiring board 10 may be arranged at overlapping positions without interfering with each other's positions, or may be arranged at non-overlapping positions.

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

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

[0041] The wiring board 10 can transmit and receive radio waves of a predetermined frequency (for example, a frequency of 1 GHz or higher) and can perform communication. The wiring board 10 may be compatible with any one of an antenna for millimeter waves, an antenna for telephones, an antenna for WiFi, an antenna for 3G, an antenna for 4G, an antenna for 5G, an antenna for LTE, an antenna for Bluetooth (registered trademark), an antenna for NFC, etc. Alternatively, the wiring board 10 may have functions such as, for example, a gesture sensing function, a wireless power supply function, a function for preventing fogging, a heater function, a hovering function (a function that allows operation even when the user does not directly touch the display), a fingerprint authentication function, a noise cut (electromagnetic wave shielding) function, etc. Here, in this specification, the "gesture sensing function" means a function of detecting the relative position (distance, angle, etc.) of an object with respect to the mesh wiring layer 20 of the wiring board 10 described later, or the moving 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 substrate 11 having transparency and a mesh wiring layer 20 disposed on the substrate 11. Further, a power supply unit 40 is electrically connected to the mesh wiring layer 20.

[0043] The shape of the substrate 11 is substantially 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 short side direction is parallel to the Y direction. The substrate 11 has transparency and is substantially flat, and its thickness is substantially uniform as a whole. Note that the shape of the substrate 11 can be appropriately selected according to the shape of the first base material 96 of the display device 95 attached to the frame 91.

[0044] The material of the substrate 11 may be any material having transparency and electrical insulation in the visible light region. As the material of the substrate 11, for example, organic insulating materials such as polyester resins, acrylic resins, polycarbonate resins, polyimide resins, polyolefin resins, cellulose resins, or fluororesin materials are preferably used. 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 or PFA or the like. For example, as the material of the substrate 11, organic insulating materials such as cycloolefin polymer (e.g., ZF-16 manufactured by Nippon Zeon Co., Ltd.) or polynorbornene polymer (manufactured by Sumitomo Bakelite Co., Ltd.) may be used. Also, as the material of the substrate 11, glass, ceramics, etc. may be appropriately selected according to the application. Although an example in which the substrate 11 is composed of a single layer is illustrated, it is not limited thereto, and a structure in which a plurality of base materials or layers are laminated may be used. Also, the substrate 11 may be a film-like member or a plate-like member.

[0045] Also, the substrate 11 has transparency. In this specification, "having transparency" means that the transmittance of visible light (light with 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 with a wavelength of 400 nm or more and 700 nm or less) of 85% or more, and preferably 90% or more. Although there is no particular upper limit to the transmittance of visible light of the substrate 11, it may be, for example, 100% or less. By setting the transmittance of visible light of the substrate 11 within the above range, when the wiring substrate 10 is incorporated into the HDM90, it is possible to suppress the visibility of the outside world from being obstructed. Note that the transmittance of visible light being 85% or more means that when the absorbance of the substrate 11 is measured using a known spectrophotometer (spectrometer manufactured by JASCO Corporation: V-670), the transmittance is 85% or more in the entire wavelength region of 400 nm or more and 700 nm or less.

[0046] The tensile elastic modulus of the substrate 11 is preferably 0.5 GPa or more and 4.5 GPa or less. When the tensile elastic modulus of the substrate 11 is 0.5 GPa or more, the rigidity of the substrate 11 can be maintained, and deformation of the substrate 11 can be suppressed. Further, when the tensile elastic modulus of the substrate 11 is 4.5 GPa or less, excessive hardening of the substrate 11 can be suppressed. Thereby, even when the substrate 11 is bent, damage to the substrate 11 can be suppressed. For this reason, a decrease in antenna performance due to deformation of the wiring substrate 10 can be suppressed. The tensile elastic modulus of the substrate 11 can be measured according to ASTM-D-882. Specifically, it can be obtained from the maximum elasticity immediately before plastic deformation (the linear equation of the tangent line of the maximum slope of the stress-strain curve) by measuring the elongation of the test piece using a tensile testing machine.

[0047] The dielectric tangent of the substrate 11 may be 0.002 or less, and preferably 0.001 or less. Note that there is no particular lower limit for the dielectric tangent of the substrate 11, and it may be more than 0. When the dielectric tangent of the substrate 11 is within the above range, particularly when the electromagnetic wave (for example, millimeter wave) transmitted and received by the mesh wiring layer 20 is a high frequency wave, the loss of gain (that is, the decrease in sensitivity) associated with the transmission and reception of the electromagnetic wave can be reduced.

[0048] The relative permittivity of the substrate 11 is preferably 2 or more and 10 or less. When the relative permittivity of the substrate 11 is 2 or more, the options for the material of the substrate 11 can be increased. Also, when the relative permittivity of the substrate 11 is 2 or more, an inexpensive material can be selected, and the manufacturing cost can be suppressed. Furthermore, when the relative permittivity of the substrate 11 is 2 or more, a material suitable for the manufacturing process can also be selected, the manufacturing yield can be improved, and the manufacturing cost can be suppressed. Also, when the relative permittivity of the substrate 11 is 10 or less, the loss of gain (sensitivity) associated with the transmission and reception of electromagnetic waves can be reduced. That is, when the relative permittivity of the substrate 11 increases, the influence of the thickness of the substrate 11 on the propagation of electromagnetic waves increases. Also, when there is an adverse effect on the propagation of electromagnetic waves, the dielectric tangent of the substrate 11 increases, and the loss of gain associated with the transmission and reception of electromagnetic waves can increase. In contrast, when the relative permittivity of the substrate 11 is 10 or less, the influence of the thickness of the substrate 11 on the propagation of electromagnetic waves can be reduced. Therefore, the loss of gain associated with the transmission and reception of electromagnetic waves can be reduced. Especially when the electromagnetic waves (for example, millimeter waves) transmitted and received by the mesh wiring layer 20 are high-frequency, the loss of gain associated with the transmission and reception of electromagnetic waves can be reduced.

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

[0050] In the present embodiment, the mesh wiring layer 20 is configured as an electromagnetic wave transmitting and receiving unit. In other words, the mesh wiring layer 20 is composed of an antenna pattern having the function of an antenna. The mesh wiring layer 20 may be configured as an array antenna including two or more antenna elements (radiating elements (tip-side portions 20b described later)). In this way, when the mesh wiring layer 20 is configured as an array antenna, the antenna performance for millimeter waves that transmit and receive millimeter waves with high directivity can be enhanced. Note that an array antenna is an antenna in which a plurality of antenna elements are regularly arranged, and an antenna 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, in the wiring substrate 10, four or more antenna elements (tip-side portions 20b described later) are provided. In the illustrated example, four mesh wiring layers 20 are formed on the substrate 11 (see FIG. 2). Further, as shown in FIG. 4, the mesh wiring layer 20 may exist not on the entire surface of the substrate 11 but only in a partial region on the substrate 11. Each mesh wiring layer 20 may have the same shape as each other. In this case, each mesh wiring layer 20 has a length (length in the Y direction) L a of error and a width (length in the X direction) W a of error that are each preferably within 10%. Thereby, the antenna performance for millimeter waves can be effectively enhanced.

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

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

[0054] In the illustrated example, the longitudinal direction of the tip-side portion 20b is parallel to the X direction, and the short-side direction thereof is parallel to the Y direction. Note that the longitudinal direction of the tip-side portion 20b may be parallel to the Y direction, and the short-side direction thereof may be parallel to the X direction. The length L in the Y direction of the tip-side portion 20b a can be selected, for example, in the range of 1 mm or more and 100 mm or less. The width W in the X direction of the tip-side portion 20b a can be selected, for example, in the range of 1 mm or more and 100 mm or less. In particular, when the mesh wiring layer 20 is an antenna for millimeter waves, the length L of the tip-side portion 20b a can be selected in the range of 1 mm or more, more preferably 1.5 mm or more. When the mesh wiring layer 20 is an antenna for millimeter waves, the length L of the tip-side portion 20b 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 appropriately set according to the corresponding frequency, but is preferably 1 mm or more and 30 mm or less. That is, the distance D between the tip-side portions 20b 20b(See FIG. 4) is preferably 1 mm or more and 30 mm or less. By setting an appropriate distance, a desired antenna directivity and gain improvement can be obtained.

[0056] As shown in FIG. 4, the mesh wiring layer 20 has a pattern shape in which metal wires are arranged in a mesh pattern. 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 extending in the first direction (for example, the Y direction) (the first direction wiring 21 described later) and a portion extending in the second direction (for example, the X direction) (the second direction wiring 22 described later).

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

[0058] The planar shapes of the first-direction wiring 21 and the second-direction wiring 22 are shapes formed by connecting a plurality of curves. In this case, the curves are arcs or elliptical arcs. In the illustrated example, the planar shapes of the first-direction wiring 21 and the second-direction wiring 22 are shapes formed by connecting a plurality of arcs. Here, the diffraction image caused by the linear structure extends in a direction orthogonal to the longitudinal direction of the structure and becomes a flare (a streak of light observed as trailing). On the other hand, when the planar shapes of the first-direction wiring 21 and the second-direction wiring 22 are shapes formed by connecting a plurality of arcs, the generated flares extend in various directions. When the generated flares extend in various directions, it becomes difficult to distinguish each flare due to the overlap of the flares. Thereby, the influence on visibility due to the flares can be reduced. In addition, when the curve is an elliptical arc, the length of the major axis of the ellipse formed by the elliptical arc may be more than 1 times and 1.1 times or less of the length of the minor axis.

[0059] In the mesh wiring layer 20, an opening 23 is formed by being surrounded by the first-direction wiring 21 and the second-direction wiring 22. Specifically, in the mesh wiring layer 20, a plurality of openings 23 are formed by being surrounded by the first-direction wiring 21 adjacent to each other and the second-direction wiring 22 adjacent to each other. The transparent substrate 11 is exposed from each opening 23. Thereby, the transparency of the entire wiring substrate 10 can be enhanced.

[0060] In the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23, the shape formed by connecting the ends of the chords of the plurality of arcs (curves) is a polygon. In this case, one side of the polygon may be composed of 2N (N is a natural number of 1 or more) chords. In the present embodiment, one side of the polygon is composed of 2 chords (N = 1). Also, in the present embodiment, in the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23, the shape formed by connecting the ends of the chords of the plurality of arcs (curves) is a square. That is, the straight line L1 connecting the ends of the chords of the first-direction wiring 21 and the straight line L2 connecting the ends of the chords of the second-direction wiring 22 are arranged at equal intervals from each other. The straight line L1 connecting the ends of the chords of the first-direction wiring 21 is arranged at equal intervals from each other, and its pitch P1 can be in the range of, for example, 0.01 mm or more and 1 mm or less. Also, the straight line L2 connecting the ends of the chords of the second-direction wiring 22 is arranged at equal intervals from each other, and the pitch P 2 can be in the range of, for example, 0.01 mm or more and 1 mm or less. Thereby, the size of the opening 23 becomes uniform within the mesh wiring layer 20, and the mesh wiring layer 20 can be made difficult to be visually recognized with the naked eye. Although each straight line L1 and each straight line L2 are orthogonal to each other, it is not limited thereto, and they may intersect at an acute angle or an obtuse angle with each other. Also, the shape of the opening 23 is preferably the same shape and the same size throughout, but it is not necessary to be uniform throughout, such as changing depending on the location. Furthermore, although not shown, one side of a polygon may be composed of four or more (N≥2) chords, or may be composed of an odd number of chords.

[0061] Here, the first-direction wiring 21 and the second-direction wiring 22 may have a shape in which a plurality of arcs cut out with a central angle of 160° or more and 200° or less are connected. In this case, the diameter of the circle from which the arc is cut out may be 0.4 times or more and 0.6 times or less 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 means the square (the shaded portion in FIG. 5) having the smallest area 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 one side into 2N equal parts, one end E 1 、E 2 of one of the ends E 1 counting from is defined as the Mth division point. Also, on one side, among the connection points between the chords, the Mth connection point counting from one end E 1 of one side is defined as the Mth connection point. At this time, 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 the polygon is composed of two chords and N = 1. Therefore, on one side, the division points obtained by dividing the side into 2N equal parts are the first division point DiP 1 which is the first division point counted from one end E 1 of the side (M = 1) only. In this embodiment, this first division point DiP 1 is the midpoint of one side. Also, on one side, the connection points between the chords are the first connection point CP 1 which is the first connection point counted from one end E 1 of the side (M = 1) only.

[0064] Thus, when N = 1 and M = 1, as shown by the virtual line (two-dot chain line) in FIG. 5, the shortest distance D 1 from the first division point DiP 1 to the first connection point CP p1 may be 0.1 times or less of the length of one side (N = 1). When the first direction wiring 21 and the second direction wiring 22 are in a shape connecting arcs satisfying the above relationship, by connecting the first direction wiring 21 and the second direction wiring 22 surrounding the opening 23, a substantially complete circle can be formed. Note that the virtual line in FIG. 5 is a curve connecting two arcs, and is the curve when the first connection point CP 1 is not the midpoint of one side (the first division point DiP 1 ).

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

[0066] As described above, the diffraction image caused by the linear structure extends in a direction orthogonal to the longitudinal direction of the structure and becomes a flare (a streak of light observed as trailing). On the other hand, when the generated flares extend in all directions (360°), it becomes difficult to distinguish each flare. That is, by a large number of flares overlapping each other in a circular shape, the influence on the visibility due to the flares can be reduced. Therefore, for the flares to extend in all directions and as a result, a large number of flares are visually recognized as overlapping each other in a circular shape, it is sufficient that the normal lines orthogonal to the longitudinal directions of the first-direction wiring 21 and the second-direction wiring 22 surrounding one opening 23 are distributed in all directions.

[0067] In contrast, in this embodiment, the first-direction wiring 21 and the second-direction wiring 22 can have a shape formed by connecting a plurality of arcs cut out with a central angle of 160° or more and 200° or less. Also, the first division point DiP 1 from the first connection point CP 1The shortest distance D to p1 can be 0.1 times or less of the side length. As a result, the normal lines orthogonal to the longitudinal directions of the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23 (see the shaded portion in FIG. 5) can be distributed in substantially all directions. For this reason, the reduction in visibility due to glare can be suppressed more effectively. In particular, the first-direction wiring 21 and the second-direction wiring 22 have a shape in which a plurality of arcs obtained by cutting circles C1, C2 having a diameter of 0.5 times the side length of a square S1 formed by a straight line L1 and a straight line L2 are connected at a central angle θ1, θ2 of 180°, and the first connection point CP 1 is the first division point DiP 1 (the midpoint of one side), the above-described normal lines are distributed in all directions. For this reason, the reduction in visibility due to glare can be suppressed more effectively.

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

[0069] In the present embodiment, the line width W of the first-direction wiring 21 1 (see FIG. 6) and the line width W of the second-direction wiring 22 2 (see FIG. 7) are not particularly limited and can be appropriately selected according to the application. Here, the line width W of the first-direction wiring 21 1 is the width in a cross section perpendicular to its longitudinal direction, and the line width W of the second-direction wiring 22 2is the width in a cross-section perpendicular to its longitudinal direction. For example, the line width W of the first-direction wiring 21 1 can be selected in the range of 0.1 μm or more and 5.0 μm or less, and may be 0.2 μm or more and 2.0 μm or less. Also, the line width W of the second-direction wiring 22 2 can be selected in the range of 0.1 μm or more and 5.0 μm or less, and may be 0.2 μm or more and 2.0 μm or less.

[0070] The height H of the first-direction wiring 21 1 (see FIG. 6) and the height H of the second-direction wiring 22 2 (see FIG. 7) are not particularly limited and can be appropriately selected according to the application. Here, the height H of the first-direction wiring 21 1 and the height H of the second-direction wiring 22 2 are each the length in the Z direction. The height H of the first-direction wiring 21 1 and the height H of the second-direction wiring 22 2 can each be selected, for example, in the range of 0.1 μm or more, and may be 0.2 μm or more. The height H of the first-direction wiring 21 1 and the height H of the second-direction wiring 22 2 can each be selected, for example, in the range of 5.0 μm or less, and may be 2.0 μm or less.

[0071] The materials of the first-direction wiring 21 and the second-direction wiring 22 may be any metallic material having conductivity. In this embodiment, the materials of the first-direction wiring 21 and the second-direction wiring 22 are copper, but are not limited thereto. As the materials of the first-direction wiring 21 and the second-direction wiring 22, for example, metallic materials such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or alloys containing these metals can be used. Also, the first-direction wiring 21 and the second-direction wiring 22 may be plating layers formed by an electrolytic plating method.

[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 within 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%. Thereby, while ensuring the conductivity of the wiring substrate 10, the transparency of the wiring substrate 10 can be increased. Note that the aperture ratio refers to the ratio (%) of the area of the opening region to the unit area of a predetermined region (for example, the entire area of the mesh wiring layer 20). The opening region refers to a region where the substrate 11 is exposed without the presence of metal portions such as the first-direction wiring 21 and the second-direction wiring 22.

[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. As the material of the protective layer, acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate, modified resins thereof, copolymers, polyesters, polyvinyl alcohol, polyvinyl acetate, polyvinyl acetal, polyvinyl butyral, etc. polyvinyl resins and their copolymers, colorless and transparent insulating resins such as polyurethane, epoxy resin, polyamide, and chlorinated polyolefin can be used.

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

[0075] Specifically, the test is performed as follows. First, the electrical resistance value between both ends in the longitudinal direction of the mesh wiring layer 20 is measured. The resistance value at this time is R 0Let it be \((\Omega)\). Next, wrap the wiring board 10 around the cylinder of the cylindrical mandrel bending tester so that both ends in the longitudinal direction of the wiring board 10 face in opposite directions by 180°. Then, remove the wiring board 10 from the cylinder and stretch it flat. Repeat this operation 100 times. Then, measure the electrical resistance value again between both ends in the longitudinal direction of the mesh wiring layer 20. Let the resistance value at this time be \(R\). 1 (\Omega)\). At this time, \(((R 1 -R 0 ) / R 0 )×100(\%)\), the value obtained by this formula is defined as the increased amount of the resistance value. When the increased amount of this resistance value is 10% or less, the durability of the wiring board 10 can be improved when the wiring board 10 is used after being bent or flexed.

[0076] Referring to FIG. 4 again, a power supply unit 40 is electrically connected to the mesh wiring layer 20. This power supply unit 40 is composed of a substantially rectangular conductive thin plate member.

[0077] Also, the power supply unit 40 is arranged at the longitudinal end (the end on the minus side in the Y direction) of the substrate 11. As the material of the power supply unit 40, for example, a metal material such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel, or an alloy containing these metals can be used.

[0078] This power supply unit 40 is electrically connected to a wireless communication circuit 94a provided on the frame 91 of the HMD90 when the wiring board 10 is incorporated into the HDM90 (see FIG. 2). Here, it is preferable that the power supply unit 40 is provided at a position overlapping the rim 92 of the frame 91 in the front view of the HMD90. Thereby, the connection between the mesh wiring layer 20 and the wireless communication circuit 94a can be made easier, and it is possible to suppress the visibility of the outside world from being obstructed. Although the power supply unit 40 is provided on the first surface 11a of the substrate 11, it is not limited to this, and part or all of the power supply unit 40 may be located outside the periphery of the substrate 11.

[0079] [Manufacturing method of wiring board] Next, referring to FIGS. 8A to 8F, the manufacturing method of the wiring board 10 according to the present embodiment will be described.

[0080] First, as shown in FIG. 8A, a substrate 11 including a first surface 11a and a second surface 11b located on the opposite side of the first surface 11a is prepared. The substrate 11 has transparency.

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

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

[0083] Next, as shown in FIG. 8C, a photocurable insulating resist 52 is supplied over substantially the entire surface of the metal foil 51. Examples of the photocurable insulating resist 52 include organic resins such as acrylic resins and epoxy resins.

[0084] Subsequently, as shown in FIG. 8D, an insulating layer 54 is formed by photolithography. In this case, the photocurable insulating resist 52 is patterned by photolithography to form the insulating layer 54 (resist pattern). At this time, the insulating layer 54 is formed such that the metal foil 51 corresponding to the first-direction wiring 21 and the second-direction wiring 22 is exposed.

[0085] Next, as shown in FIG. 8E, the metal foil 51 located on the portion of the first surface 11a of the substrate 11 that is not covered by the insulating layer 54 is removed. At this time, wet treatment using strong acids such as ferric chloride, cupric chloride, sulfuric acid and hydrochloric acid, persulfates, hydrogen peroxide or their aqueous solutions, or combinations thereof is performed to etch the metal foil 51 so that the first surface 11a of the substrate 11 is exposed.

[0086] Subsequently, as shown in FIG. 8F, the insulating layer 54 is removed. In this case, wet processing using a permanganate solution, N-methyl-2-pyrrolidone, an acid or an alkali solution, etc., or dry processing using oxygen plasma is performed to remove the insulating layer 54 on the metal foil 51.

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

[0088] Then, by attaching the wiring substrate 10 to the first base material 96 fitted into the rim 92 of the frame 91, the HMD 90 shown in FIG. 1 is obtained. Note that the wiring substrate 10 may be attached to the first base material 96 before the first base material 96 is fitted into the rim 92 of the frame 91.

[0089] [Operation of the Present Embodiment] Next, the operation of the present embodiment having such a configuration will be described.

[0090] As shown in FIG. 2, the wiring substrate 10 is incorporated into the HMD 90 as a component of the display device 95. The mesh wiring layer 20 of the wiring substrate 10 is electrically connected to the wireless communication circuit 94a of the HMD 90 via the power supply part 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 shapes of the first-direction wiring 21 and the second-direction wiring 22 are shapes formed by connecting a plurality of arcs. As a result, the generated light rays extend in various directions. Therefore, due to the overlapping of the respective light rays, it becomes difficult to distinguish each light ray. As a result, it is possible to suppress a decrease in visibility due to the light rays. Also, in this case, it is possible to suppress a decrease in visibility due to the light rays without increasing the variation in the pitch of the first-direction wiring 21 and the variation in the pitch of the second-direction wiring 22. For this reason, it is possible to suppress the flickering caused by the reflection of visible light by the mesh wiring layer 20. Furthermore, since the planar shapes of the first-direction wiring 21 and the second-direction wiring 22 are shapes formed by connecting a plurality of arcs, it is possible to reduce the reflection of electromagnetic waves in the first-direction wiring 21 and the second-direction wiring 22. For this reason, the transmission efficiency in the wiring substrate 10 can be increased.

[0092] Also, 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. And the aperture ratio of the mesh wiring layer 20 is 94% or more. For this reason, the transparency of the wiring substrate 10 is ensured. As a result, when the wiring substrate 10 is incorporated into the HMD 90, the outside can be visually recognized through the openings 23 of the mesh wiring layer 20, so the visibility of the outside is not hindered.

[0093] Next, a modified example of the wiring substrate will be described.

[0094] FIG. 9 shows a first modified example of the wiring substrate 10. The modified example shown in FIG. 9 is different in that the first-direction wiring 21 and the second-direction wiring 22 have a shape formed by connecting a plurality of arcs cut out with a central angle of 80° or more and 100° or less, and other configurations are substantially the same as the forms shown in FIGS. 1 to 8F described above. In FIG. 9, the same parts as those in the forms shown in FIGS. 1 to 8F are denoted by the same reference numerals, and detailed description thereof is omitted.

[0095] In the wiring board 10 shown in FIG. 9, the first-direction wiring 21 and the second-direction wiring 22 have a shape in which a plurality of arcs cut out with a central angle of 80° or more and 100° or less are connected. In this case, the diameter of the circle from which the arc is cut out 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 modified example as well, on one side of the square S1 formed by the straight lines L1 and L2, the shortest distance D 1 from the first division point DiP 1 to the first connection point CP p1 (see FIG. 5) may be 0.1 times or less the length of one side. Even when the first-direction wiring 21 and the second-direction wiring 22 have a shape in which arcs satisfying the above relationship are connected, by joining the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23, a substantially complete circle can be formed.

[0096] In this modified example, as shown in FIG. 9, the first-direction wiring 21 has a shape in which a plurality of arcs cut out with a central angle θ3 of 90° are connected. In this case, the diameter of the circle C3 from which the arc is cut out 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 located on the first division point DiP 1 (the midpoint of one side). Also, the second-direction wiring 22 has a shape in which a plurality of arcs cut out with a central angle θ4 of 90° are connected. In this case, the diameter of the circle C4 from which the arc is cut out 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 1It is located on the midpoint of one side. Also in this case, by connecting the first-direction wiring 21 and the second-direction wiring 22 that surround the opening 23, a plurality of complete circles can be formed. Also in this case, since a large number of rays overlap each other in a circular shape, the influence on the visibility due to the rays can be reduced. Therefore, the decrease in visibility due to the rays can be more effectively suppressed.

[0097] Further, in this modification, the first-direction wiring 21 has a shape formed by connecting a plurality of arcs cut out with a central angle θ3 of 80° or more and 100° or less, and the second-direction wiring 22 has a shape formed by connecting a plurality of arcs cut out with a central angle θ4 of 80° or more and 100° or less. In this case, in the first-direction wiring 21 and the second-direction wiring 22 that surround the opening 23, the difference between the line length of the shape (polygon) formed by connecting the ends of the chords of the plurality of curves and the total line length of the first-direction wiring 21 and the second-direction wiring 22 can be made small. In other words, compared with the case where the central angle θ3 and the central angle θ4 are, for example, 180°, since the central angle θ3 and the central angle θ4 are 80° or more and 100° or less, the increase rate of the total line length of the first-direction wiring 21 and the second-direction wiring 22 with respect to the above-described polygon can be reduced. Thereby, an increase in the resistance value of the mesh wiring layer 20 can be suppressed.

[0098] Further, since the increase rate of the above-described line length can be reduced, a decrease in the aperture ratio of the mesh wiring layer 20 can be suppressed. Also, since the increase rate of the above-described line length can be reduced, it is possible to suppress the line lengths of the first-direction wiring 21 and the second-direction wiring 22 from becoming too long. Therefore, the risk of disconnection of the first-direction wiring 21 and the second-direction wiring 22 can also be reduced. Furthermore, since it is possible to suppress the line lengths of the first-direction wiring 21 etc. and the second-direction wiring 22 from becoming too long, the patterning accuracy when manufacturing the first-direction wiring 21 and the second-direction wiring 22, as well as the dimensional stability of the first-direction wiring 21 and the second-direction 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 is different in that the shape in which the ends of the chords of a plurality of curves are connected in the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23 is a rhombus, and other configurations are substantially the same as those shown in FIGS. 1 to 9 described above. In FIG. 10A, the same parts as those shown in FIGS. 1 to 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

[0100] In the wiring board 10 shown in FIG. 10A, in the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23, the shape in which the ends of the chords of a plurality of curves are connected is a rhombus. In other words, the polygon described above is a rhombus. In this case, the first-direction wiring 21 and the second-direction wiring 22 extend in directions non-parallel to either the X direction or the Y direction. Thereby, the resistance in the Y direction in which current flows can be reduced. For this reason, the antenna characteristics can be improved.

[0101] Further, the first-direction wiring 21 and the second-direction wiring 22 have a shape in which a plurality of arcs cut out with a central angle of 160° or more and 200° or less are connected. In this case, the diameter of the circle from which the arc is cut out may be 0.4 times or more and 0.6 times or less the length of one side of the rhombus S2 formed by the straight line L1 and the straight line L2. Also, as shown by the virtual line (two-dot chain line) in FIG. 10A, on one side of the rhombus S2 formed by the straight line L1 and the straight line L2, the first division point DiP 1 from the first connection point CP 1 to the shortest distance D p2 may be 0.1 times or less the length of one side. Even when the first-direction wiring 21 and the second-direction wiring 22 are in a shape in which arcs satisfying the above relationship are connected, by joining the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23, a substantially complete circle can be formed. Note that the virtual line in FIG. 10A is a curve connecting two arcs, and the curve when the first connection point CP 1 is not the midpoint of one side (the first division point DiP 1 ).

[0102] In this modified example, as shown in FIG. 10A, the first-direction wiring 21 has a shape formed by connecting a plurality of arcs cut out with a central angle θ5 of 180°. In this case, the diameter of the circle C5 from which the arcs are cut out is 0.5 times the length of one side of the rhombus S2 formed by the straight line L1 and the straight line L2. Also, on one side of the rhombus S2 formed by the straight line L1 and the straight line L2, the first connection point CP 1 is located on the first division point DiP 1 (the midpoint of one side). Also, the second-direction wiring 22 has a shape formed by connecting a plurality of arcs cut out with a central angle θ6 of 180°. In this case, the diameter of the circle C6 from which the arcs are cut out is 0.5 times the length of one side of the rhombus S2 formed by the straight line L1 and the straight line L2. Also, on one side of the rhombus S2 formed by the straight line L1 and the straight line L2, the first connection point CP 1 is located on the first division point DiP 1 (the midpoint of one side). Also in this case, by joining the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23, a plurality of complete circles can be formed. Also in this case, since a large number of rays overlap each other in a circular shape, the influence on the visibility due to the rays can be reduced. Therefore, the decrease in visibility due to the rays can be more effectively suppressed.

[0103] Note that in the wiring board 10 shown in FIG. 10A, an example in which the first-direction wiring 21 and the second-direction wiring 22 have a shape formed by connecting a plurality of arcs cut out with a central angle of 160° or more and 200° or less has been described, but it is not limited to this. For example, the first-direction wiring 21 and the second-direction wiring 22 may have a shape formed by connecting a plurality of arcs cut out with a central angle of 80° or more and 100° or less. Also in this case, the diameter of the circle from which the arcs are cut out may be 0.4 times or more and 0.6 times or less the length of one side of the rhombus S2 formed by the straight line L1 and the straight line L2. Also, as shown by the virtual line (two-dot chain line) in FIG. 10B, on one side of the rhombus S2 formed by the straight line L1 and the straight line L2, the shortest distance D 1 from the first division point DiP 1 to the first connection point CP p2It may be 0.1 times or less the length of one side. Note that the virtual line in Fig. 10B is a curve connecting two arcs, and the first connection point CP 1 is a curve when it is not at the midpoint of one side (the first division point DiP 1 ).

[0104] In this modification, as shown in Fig. 10B, the first-direction wiring 21 has a shape formed by connecting a plurality of arcs cut out with a central angle θ5 of 90°. Also in this case, the diameter of the circle C5 from which the arc is cut out 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 located on the first division point DiP 1 (the midpoint of one side). Also, the second-direction wiring 22 has a shape formed by connecting a plurality of arcs cut out with a central angle θ6 of 90°. Also in this case, the diameter of the circle C6 from which the arc is cut out 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 located on the first division point DiP 1 (the midpoint of one side).

[0105] Also in the example shown in FIG. 10B, by connecting the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23, a plurality of complete circles can be formed. Also in this case, since a large number of rays overlap each other in a circular shape, the influence on the visibility due to the rays can be reduced. Therefore, the decrease in visibility due to the rays can be more effectively suppressed. Also in the example shown in FIG. 10B, the increase rate of the total wire length of the first-direction wiring 21 and the second-direction wiring 22 with respect to the above-described polygon can be reduced, and an increase in the resistance value of the mesh wiring layer 20 can be suppressed. Also, since the increase rate of the wire length described above 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, since the wire length of the first-direction wiring 21 and the wire length of the second-direction wiring 22 can be suppressed from becoming too long, the risk of disconnection of the first-direction wiring 21 and the second-direction wiring 22 can be reduced. Furthermore, the patterning accuracy when manufacturing the first-direction wiring 21 and the second-direction wiring 22, and the dimensional stability of the first-direction wiring 21 and the second-direction wiring 22 can be improved. Therefore, the productivity of the wiring substrate 10 can be improved.

[0106] FIG. 11 shows a third modification example of the wiring substrate 10. The modification example shown in FIG. 11 is different in that one side of the rhombus S2 is composed of four (N = 2) chords, and other configurations are substantially the same as the forms shown in FIGS. 1 to 10B described above. In FIG. 11, the same parts as those in the forms shown in FIGS. 1 to 10B are denoted by the same reference numerals, and detailed description thereof is omitted.

[0107] In the wiring substrate 10 shown in FIG. 11, one side of the rhombus S2 is composed of four (N = 2) chords. Therefore, on one side, the division points obtained by dividing one side into four (N = 2) are the first division point DiP 1 , the second division point DiP 2 and the third division point DiP 3 , a total of three. Among these, the second division point DiP 2 is the midpoint of one side. Also, on one side, the connection points between the chords are the first connection point CP 1 , the second connection point CP 2 and the third connection point CP 3 , a total of three.

[0108] In this modified example, as shown by the virtual line (two-dot chain line) in FIG. 11, on one side of the rhombus S2, the first division point DiP 1 to the first connection point CP 1 The shortest distance D p3 may be 0.05 times or less (N = 2) the length of one side. Also, on one side of the rhombus S2, the second division point DiP 2 to the second connection point CP 2 The shortest distance D p4 may be 0.05 times or less (N = 2) the length of one side. Further, on one side of the rhombus S2, the third division point DiP 3 to the third connection point CP 3 The shortest distance D p5 may be 0.05 times or less (N = 2) the length of one side. Even when the first-direction wiring 21 and the second-direction wiring 22 are in a shape connecting arcs satisfying the above relationship, by joining the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23, a nearly complete circle can be formed. Note that the virtual line in FIG. 11 is a curve connecting four arcs, and the first connection point CP 1 is not the first division point DiP 1 , but the second connection point CP 2 is not the second division point DiP 2 , but the third connection point CP 3 is not the third division point DiP 3 It is a curve when it is not.

[0109] As shown in FIG. 11, the diameters of the circles C5 and C6 from which the arcs are cut are 0.25 times the length of one side of the rhombus S2. Also, on one side of the rhombus S2 formed by the straight line L1 and the straight line L2, the first connection point CP 1 is located on the first division point DiP 1 , the second connection point CP 2 is located on the second division point DiP 2 (the midpoint of one side), and the third connection point CP 3 is located on the third division point DiP 3 .

[0110] In this modified example, as shown in FIG. 11, on one side of the rhombus S2, the first division point DiP1 to the first connection point CP 1 The shortest distance D p3 is 0.05 times or less of the side length (N = 2). Also, on one side of the rhombus S2, the second division point DiP 2 to the second connection point CP 2 The shortest distance D p4 is 0.05 times or less of the side length (N = 2). Further, on one side of the rhombus S2, the third division point DiP 3 to the third connection point CP 3 The shortest distance D p5 is 0.05 times or less of the side length (N = 2). Also in this case, by connecting the first direction wiring 21 and the second direction wiring 22 surrounding the opening 23, a plurality of complete circles can be formed. Also in this case, by overlapping a large number of rays in a circular shape, the influence on the visibility due to the rays can be reduced. Therefore, the decrease in visibility due to the rays can be more effectively suppressed.

[0111] FIG. 12A shows a fourth modification of the wiring board 10. The modification shown in FIG. 12A is different in that the shape in which the ends of the chords of a plurality of curves are connected in the first direction wiring 21, the second direction wiring 22, and the third direction wiring 24 surrounding the opening 23 is a regular hexagon, and other configurations are substantially the same as the forms shown in FIGS. 1 to 11 described above. In FIG. 12A, the same parts as those in the forms shown in FIGS. 1 to 11 are denoted by the same reference numerals and detailed description thereof is omitted.

[0112] In the wiring board 10 shown in FIG. 12A, in the first-direction wiring 21, second-direction wiring 22, and third-direction wiring (wiring) 24 that surround the opening 23, the shape in which the ends of the chords of a plurality of curves are connected to each other is a regular hexagon. In other words, the polygon described above is a regular hexagon. In this case, the first-direction wiring 21 and the second-direction wiring 22 extend in directions that are not parallel to either the X direction or the Y direction. On the other hand, the third-direction wiring 24 extends in the X direction. Thereby, the resistance in the Y direction through which current flows can be reduced. For this reason, the antenna characteristics can be improved. Further, since the third-direction wiring 24 connects the first-direction wiring 21 and the second-direction wiring 22, disconnection of the mesh wiring layer 20 can be effectively suppressed. Note that the third-direction wiring 24 may extend in a direction that is not parallel to either the X direction or the Y direction. Note that the line width and height of the third-direction wiring 24, and the material and the like that constitute the third-direction wiring 24 may be the same as those of the first-direction wiring 21.

[0113] Further, the first-direction wiring 21, second-direction wiring 22, and third-direction wiring 24 have a shape in which a plurality of arcs cut out with a central angle of 160° or more and 200° or less are connected. In this case, the diameter of the circle from which the arc is cut out may be 0.4 times or more and 0.6 times or less the length of one side of the regular hexagon S3 formed by the straight line L1, straight line L2, and straight line L3. Also, as shown by the virtual line (two-dot chain line) in FIG. 12A, on one side of the regular hexagon S3 formed by the straight line L1, straight line L2, and straight line L3, the first division point DiP 1 to the first connection point CP 1 The shortest distance D p6 may be 0.1 times (N = 1) or less the length of one side. Even when the first-direction wiring 21, second-direction wiring 22, and third-direction wiring 24 have a shape in which arcs satisfying the above relationship are connected, by joining the first-direction wiring 21, second-direction wiring 22, and third-direction wiring 24 that surround the opening 23, a substantially complete circle can be formed. Note that the virtual line in FIG. 12A is a curve connecting two arcs, and the first connection point CP 1 is a curve when it is not the midpoint of one side (the first division point DiP 1 ).

[0114] In this modification example, as shown in FIG. 12A, the first-direction wiring 21 has a shape in which a plurality of arcs cut out with a central angle θ7 of 180° are connected. In this case, the diameter of the circle C7 from which the arcs are cut out is 0.5 times the length of one side of the regular hexagon S3 formed by the straight line L1, the straight line L2, and the straight line L3. Also, on one side of the regular hexagon S3 formed by the straight line L1, the straight line L2, and the straight line L3, the first connection point CP 1 is located on the first division point DiP 1 (the midpoint of one side). Also, the second-direction wiring 22 has a shape in which a plurality of arcs cut out with a central angle θ8 of 180° are connected. In this case, the diameter of the circle C8 from which the arcs are cut out is 0.5 times the length of one side of the regular hexagon S3 formed by the straight line L1, the straight line L2, and the straight line L3. Also, on one side of the regular hexagon S3 formed by the straight line L1, the straight line L2, and the straight line L3, the first connection point CP 1 is located on the first division point DiP 1 (the midpoint of one side). Further, the third-direction wiring 24 has a shape in which a plurality of arcs cut out with a central angle θ9 of 180° are connected. In this case, the diameter of the circle C9 from which the arcs are cut out is 0.5 times the length of one side of the regular hexagon S3 formed by the straight line L1, the straight line L2, and the straight line L3. Also, on one side of the regular hexagon S3 formed by the straight line L1, the straight line L2, and the straight line L3, the first connection point CP 1 is located on the first division point DiP 1 (the midpoint of one side). Also in this case, by joining together the first-direction wiring 21, the second-direction wiring 22, and the third-direction wiring 24 surrounding the opening 23, a plurality of complete circles can be formed. Also in this case, since a large number of rays overlap each other in a circular shape, the influence on the visibility due to the rays can be reduced. Therefore, the decrease in visibility due to the rays can be more effectively suppressed.

[0115] Also, in this modified example, in the first-direction wiring 21, second-direction wiring 22, and third-direction wiring 24 surrounding the opening 23, the shape (polygon) formed by connecting the ends of the chords of a plurality of curves is a regular hexagon. In this case, the maximum number of wirings (first-direction wiring 21, second-direction wiring 22, and third-direction wiring 24) connected to the vertices of the polygon is three. Also, at the vertices of the polygon, the angles formed by the first-direction wiring 21, second-direction wiring 22, and third-direction wiring 24 with each other are 120°, which is larger than the case where the polygon is a square. Therefore, near the vertices of the polygon, the patterning accuracy when fabricating the first-direction wiring 21, second-direction wiring 22, and third-direction wiring 24, and the dimensional stability of the first-direction wiring 21, second-direction wiring 22, and third-direction wiring 24 can be improved. For this reason, the productivity of the wiring board 10 can be improved.

[0116] In addition, in the wiring board 10 shown in FIG. 12A, an example in which the first-direction wiring 21, second-direction wiring 22, and third-direction wiring 24 have a shape formed by connecting a plurality of arcs cut out with a central angle of 160° or more and 200° or less has been described, but it is not limited to this. For example, the first-direction wiring 21, second-direction wiring 22, and third-direction wiring 24 may have a shape formed by connecting a plurality of arcs cut out with a central angle of 80° or more and 100° or less. Even in this case, the diameter of the circle from which the arc is cut out may be 0.4 times or more and 0.6 times or less the length of one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3. Also, as shown by the virtual line (two-dot chain line) in FIG. 12B, on one side of the regular hexagon S3 formed by the straight lines L1, L2, and L3, from the first division point DiP 1 to the first connection point CP 1 the shortest distance D p6 may be 0.1 times (N = 1) or less the length of one side. The virtual line in FIG. 12B is a curve connecting two arcs, and is a curve when the first connection point CP 1 is not the midpoint of one side (the first division point DiP 1 ).

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

[0118] Also in the example shown in FIG. 12B, by connecting the first-direction wiring 21, the second-direction wiring 22, and the third-direction wiring 24 surrounding the opening 23, a plurality of complete circles can be formed. Also in this case, since a large number of rays overlap each other in a circular shape, the influence on visibility due to the rays can be reduced. Therefore, the decrease in visibility due to the rays can be more effectively suppressed. Also in the example shown in FIG. 12B, the increase rate of the total wire length of the first-direction wiring 21, the second-direction wiring 22, and the third-direction wiring 24 with respect to the above-described polygon can be reduced, and an increase in the resistance value of the mesh wiring layer 20 can be suppressed. Also, since the increase rate of the above-described wire 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, since the wire length of the first-direction wiring 21, the wire length of the second-direction wiring 22, and the wire length of the third-direction wiring 24 can be suppressed from becoming too long, the risk of disconnection of the first-direction wiring 21, the second-direction wiring 22, and the third-direction wiring 24 can be reduced. Furthermore, the patterning accuracy when manufacturing the first-direction wiring 21, the second-direction wiring 22, and the third-direction wiring 24, and the dimensional stability of the first-direction wiring 21, the second-direction wiring 22, and the third-direction wiring 24 can be improved. Therefore, the productivity of the wiring substrate 10 can be improved.

[0119] FIG. 13 shows a fifth modification of the wiring substrate. The modification shown in FIG. 13 is different in that the corners of the polygon are arranged irregularly, and the other configurations are substantially the same as the forms shown in FIGS. 1 to 12B described above. In FIG. 13, the same parts as those in the forms shown in FIGS. 1 to 12B are denoted by the same reference numerals, and detailed description thereof is omitted.

[0120] In the wiring substrate 10 shown in FIG. 13, the corners of the polygon S4 formed by the straight line L1 and the straight line L2 are arranged irregularly. That is, the straight line L1 connecting the ends of the chords of the first-direction wiring 21 and the straight line L2 connecting the ends of the chords of the second-direction wiring 22 are arranged irregularly with respect to each other. Specifically, the straight line L1 is arranged in parallel with each other, and its pitch P 1 is irregular. Similarly, the straight line L2 is arranged in parallel with each other, and its pitch P 2 is irregular. Thus, the pitch P of the straight line L11 and the pitch P of the straight line L2 2 By making the pitches irregular, it is possible to suppress a decrease in visibility due to the light beams. Also, even in this case, by connecting the first-direction wiring 21 and the second-direction wiring 22 surrounding the opening 23, a plurality of complete circles can be formed. Also in this case, since a large number of light beams overlap each other in a circular shape, the influence on visibility due to the light beams can be reduced. Therefore, a decrease in visibility due to the light beams can be more effectively suppressed.

[0121] Note that, as shown in FIG. 14, the polygon S5 formed by the straight lines L1 and L2 may be a quadrilateral in which opposite sides are not parallel. In this case, the chord of the curve may extend in a bent linear shape. In other words, the chords connected to each other may extend in directions that are not parallel to each other. Also, as shown in FIG. 15, in the mesh wiring (wiring) 200 surrounding the opening 23, the shape in which the ends of the chords of the plurality of arcs (curves) are connected to each other is the polygon S6, and the planar structure formed by the polygon S6 may be a Voronoi pattern. Note that the line width and height of the mesh wiring 200, and the material and the like constituting the mesh wiring 200 may be the same as those of the first-direction wiring 21.

[0122] FIGS. 16 and 17 show a sixth modification of the wiring board. The modifications shown in FIGS. 16 and 17 are different in that a dummy wiring layer 30 is provided around the mesh wiring layer 20, and other configurations are substantially the same as the forms shown in FIGS. 1 to 15 described above. In FIGS. 16 and 17, the same parts as those in the forms shown in FIGS. 1 to 15 are denoted by the same reference numerals, and detailed description thereof is omitted.

[0123] In the wiring board 10 shown in FIG. 16, a dummy wiring layer 30 is provided along the periphery of the mesh wiring layer 20. This dummy wiring layer 30 is different from the mesh wiring layer 20 and does not substantially function as an antenna.

[0124] As shown in FIG. 17, the dummy wiring layer 30 is composed of repetitions of 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-direction wiring 21 and the second-direction wiring 22) respectively. Also, the plurality of dummy wirings 30a are regularly arranged over the entire area within 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 on the substrate 11. That is, each dummy wiring 30a is electrically independent from the mesh wiring layer 20, the power supply unit 40, and other dummy wirings 30a.

[0125] In this case, the dummy wiring 30a has a shape in which a part of the pattern shape of the above-described mesh wiring layer 20 is missing. Thereby, the difference between the mesh wiring layer 20 and the dummy wiring layer 30 can be made difficult to be visually recognized, and the mesh wiring layer 20 arranged on the substrate 11 can be made less visible. As shown in FIG. 17, the dummy wiring 30a includes a first portion 31a obtained by cutting out a part of the first-direction wiring 21 and a second portion 32a obtained by cutting out a part of the second-direction wiring 22. Thus, since the dummy wiring 30a is composed of a portion in which a part of the first-direction wiring 21 or the second-direction wiring 22 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 it is preferably close to the aperture ratio of the mesh wiring layer 20. Therefore, within the region of the dummy wiring layer 30, copper wirings having the same shape as the missing portion may be arranged at arbitrary positions so that the dummy wirings 30a are not connected to each other. In this case, within the region of the dummy wiring layer 30, copper wirings having the same area as the missing portion in plan view may be arranged at arbitrary positions so that the dummy wirings 30a are not connected to each other.

[0126] As in this modified example, by providing a dummy wiring layer 30 that is electrically independent of the mesh wiring layer 20 around the mesh wiring layer 20, the outer edge of the mesh wiring layer 20 can be made unclear. As a result, the mesh wiring layer 20 can be made less visible on the surface of the HMD90, and it can be made more difficult for the user of the HMD90 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 examples shown in Figures 18 and 19 are different in that a plurality of dummy wiring layers 30A and 30B having different aperture ratios are provided around the mesh wiring layer 20, and 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 denoted by the same reference numerals, and detailed description thereof is omitted.

[0128] In the wiring board 10 shown in Figure 18, a plurality (two in this case) of dummy wiring layers 30A and 30B (first dummy wiring layer 30A and 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 and 30B do not substantially function as antennas.

[0129] As shown in FIG. 19, the first dummy wiring layer 30A is composed of repetitions of dummy wirings 30a1 having a predetermined pattern shape. Further, the second dummy wiring layer 30B is composed of repetitions of dummy wirings 30a2 having a predetermined pattern shape. 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 of the mesh wiring layer 20. Also, the dummy wirings 30a1 and 30a2 are regularly arranged over the entire area within the dummy wiring layers 30A and 30B, respectively. Each of the dummy wirings 30a1 and 30a2 is spaced apart from each other in the plane direction and is disposed so as to protrude on the substrate 11. Each of the dummy wirings 30a1 and 30a2 is electrically independent of the mesh wiring layer 20, the power supply unit 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 part of the pattern shape of the mesh wiring layer 20 described above is missing. Thereby, 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 can be made difficult to visually recognize, and the mesh wiring layer 20 disposed on the substrate 11 can be made less visible. As shown in FIG. 19, the dummy wiring 30a1 includes a first portion 31a1 having a shape in which a part of the first direction wiring 21 is cut out, and a second portion 32a1 having a shape in which a part of the second direction wiring 22 is cut out. The dummy wiring 30a2 includes a first portion 31a2 in which a part of the first direction wiring 21 is cut out, and a second portion 32a2 in which a part of the second direction wiring 22 is cut out.

[0131] Note that the area of each dummy wiring 30a1 of the first dummy wiring layer 30A is larger than the area of each dummy wiring 30a2 of 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 it is not limited thereto, and the line width of each dummy wiring 30a1 may be thicker than the line width of each dummy wiring 30a2.

[0132] In this modification example, it is preferable that the aperture ratios of the mesh wiring layer 20 and the plurality of dummy wiring layers 30A and 30B gradually increase from the mesh wiring layer 20 toward the dummy wiring layers 30A and 30B that are farther from the mesh wiring layer 20. In other words, it is preferable that the aperture ratio of each dummy wiring layer gradually increases from the one closer to the mesh wiring layer 20 toward the one farther from the mesh wiring layer 20. In this case, the aperture ratio of the first dummy wiring layer 30A is preferably larger than the aperture ratio of the mesh wiring layer 20. The aperture ratio of the second dummy wiring layer 30B is preferably larger than the aperture ratio of the first dummy wiring layer 30A. Thereby, the outer edges of the mesh wiring layer 20 and the dummy wiring layers 30A and 30B can be made even less distinct. For this reason, the mesh wiring layer 20 can be made even less visible on the surface of the HMD 90.

[0133] As described above, by arranging the dummy wiring layers 30A and 30B that are electrically independent from the mesh wiring layer 20, the outer edge of the mesh wiring layer 20 can be made less distinct. Thereby, the mesh wiring layer 20 can be made less visible on the surface of the HMD 90, and it can be made difficult for the user of the HMD 90 to recognize the mesh wiring layer 20 with the naked eye. Note that three or more dummy wiring layers having different aperture ratios from each other may be provided around the mesh wiring layer 20.

[0134] It is also possible to appropriately combine a plurality of components disclosed in the above-described embodiments and each modification example as needed. Alternatively, some components may be deleted from all the components shown in the above-described embodiments and each modification example.

Claims

1. A wiring board, A transparent substrate; a mesh wiring layer disposed on the substrate; The mesh wiring layer has wiring, The planar shape of the wiring is a shape in which a plurality of curved lines are connected, 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 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, A wiring board, wherein the Mth connection point is not located on the Mth division point.

2. 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.

3. 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.

4. The wiring board according to claim 1 , wherein corners of the polygon are irregularly arranged.

5. The wiring board according to claim 1 , wherein the polygon is a square or a rhombus.

6. The wiring board according to claim 1 , wherein the strings that are connected to each other extend in directions that are not parallel to each other.

7. The wiring board according to claim 1 , wherein the polygon is a hexagon.

8. The wiring board according to claim 1 , wherein the planar structure formed by the polygons is a Voronoi pattern.

9. 5. The wiring board according to claim 1, wherein the wiring has a first directional wiring extending in a first direction and a second directional wiring extending in a second direction different from the first direction, and the opening is formed by being surrounded by the first directional wiring and the second directional wiring.

10. 5. The wiring board according to claim 1, wherein the wiring has a first directional wiring extending in a first direction, a second directional wiring extending in a second direction different from the first direction, and a third directional wiring extending in a third direction non-parallel to both the first direction and the second direction, and the opening is formed by being surrounded by the first directional wiring, the second directional wiring, and the third directional wiring.

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

12. A method for manufacturing a wiring board, comprising: Providing a transparent substrate; forming a mesh wiring layer on the substrate; The mesh wiring layer has wiring, The planar shape of the wiring is a shape in which a plurality of curved lines are connected, 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 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, The method for manufacturing a wiring substrate, wherein the Mth connection point is not located on the Mth division point.

Images