Antenna unit

Abstract

This antenna unit (1) comprises: a monopole antenna (30) having a first electrode (12a), a second electrode (12b), and a radiating part (31) positioned between the first electrode (12a) and the second electrode (12b); and a plate-form conductor (40) that is positioned below the monopole antenna (30), overlaps the radiating part (31) in plan view, and is separated from the monopole antenna (30). The monopole antenna (30) has a first branch electrode section (33a) that is positioned to the right when viewed from the radiating part (31) and is electrically connected to the conductor (40), and a second branch electrode section (33b) that is positioned to the left when viewed from the radiating part (31) and is electrically connected to the conductor (40).

Description

Antenna Unit

[0001] The present invention relates to an antenna unit.

[0002] 2. Description of the Related Art Conventionally, a technique disclosed in Patent Document 1 is known, for example, regarding an antenna unit including a monopole antenna.

[0003] 7 of Patent Document 1 discloses a touch panel (touch panel 6) equipped with a monopole antenna. Specifically, this touch panel includes a plurality of sensor electrodes (a plurality of X-direction electrodes 61 and a plurality of Y-direction electrodes 62) and a monopole antenna (antenna structure 5). Both the plurality of sensor electrodes and the monopole antenna are formed on the surface of a film that constitutes the touch panel.

[0004] The plurality of X-direction electrodes each extend along the X direction and are spaced apart from one another in the Y direction. The plurality of Y-direction electrodes each extend along the Y direction and are spaced apart from one another in the X direction. The plurality of X-direction electrodes and the plurality of Y-direction electrodes are both made of a transparent conductor processed into a mesh shape.

[0005] The monopole antenna (antenna structure 5) includes an antenna element portion. The antenna element portion includes a radiation electrode (multi-frequency antenna 12a) that shares two frequencies and a pair of antenna GNDs (antenna GNDs 12b, 12b), each connected to ground potential (GND). The radiation electrode and the pair of antenna GNDs are both made of a transparent conductor processed into a mesh pattern. The radiation electrode extends from the pair of antenna GNDs in the Y direction (away from the multiple Y-direction electrodes).

[0006] Patent No. 7195645

[0007] In the above touch panel, in a plan view, multiple sensor electrodes are arranged in the so-called "active area" of the film, while the monopole antenna is arranged in the so-called "inactive area" of the film (a region of the film located outside the active area). Therefore, in the above touch panel, the region of the inactive area where the monopole antenna is located is relatively enlarged. In other words, in the above touch panel, the positional relationship between the multiple electrodes and the monopole antenna impairs the narrow frame of the inactive area.

[0008] In order to optimize the positional relationship between the multiple electrodes and the monopole antenna (to improve the narrowing of the non-active area), it is conceivable to dispose a portion of the monopole antenna within the active area. Specifically, a configuration is conceivable in which the radiation electrodes extend in the opposite Y direction from a pair of antenna GNDs (i.e., in the direction approaching the multiple Y-direction electrodes) and a portion of the radiation electrode is disposed between any Y-direction electrodes adjacent to each other in the X direction (hereinafter referred to as a "provisional configuration"). Such a provisional configuration makes it possible to reduce the area in the non-active area where the monopole antenna is located.

[0009] However, in the above-mentioned hypothetical configuration, the Y-direction electrode located near the radiation electrode blocks the path of the electric field generated between each antenna GND and the radiation electrode in the planar direction of the film. Specifically, a portion of the electric field acts on the transparent conductor constituting the Y-direction electrode, making it easier for a portion of the electric field to deviate from the path. As a result, the electric field is disturbed and the radio waves generated from the monopole antenna are less likely to travel. Thus, in the above-mentioned hypothetical configuration, optimizing the positional relationship between the multiple electrodes and the monopole antenna can cause another problem, such as impaired antenna characteristics of the monopole antenna.

[0010] The present disclosure has been made in consideration of these points, and its purpose is to ensure the antenna characteristics of a monopole antenna.

[0011] To achieve the above object, one embodiment of the present disclosure is an antenna unit including: a monopole antenna having a first electrode extending in a first direction and formed of a thin metal wire; a second electrode extending in the first direction and formed of a thin metal wire; a radiating portion located between the first electrode and the second electrode in a planar view; and a plate-shaped conductor located below the monopole antenna, overlapping with the radiating portion in a planar view, and spaced apart from the monopole antenna. The monopole antenna further includes a first branch electrode located to the right of the radiating portion and electrically connected to the conductor, and a second branch electrode located to the left of the radiating portion and electrically connected to the conductor.

[0012] According to the present disclosure, the antenna characteristics of a monopole antenna can be ensured.

[0013] FIG. 1 is an overall perspective view of an antenna unit according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 2. FIG. 3 is a partially enlarged view of portion III in FIG. 2. FIG. 4 is a perspective view schematically illustrating a touch sensor in a plan view. FIG. 5 is a diagram schematically illustrating a mesh pattern configuration. FIG. 6 is a cross-sectional view schematically illustrating the cross-sectional structure of a conductive wire. FIG. 7 is a partially enlarged view of portion VII in FIG. 4. FIG. 8 is a partially enlarged perspective view schematically illustrating the positional relationship of each element constituting the antenna unit. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. FIG. 10 is a cross-sectional view taken along line X-X in FIG. 8. FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 8. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 8. FIG. 13 is a partially enlarged view of portion XIII in FIG. 11. FIG. 14 is a view of an antenna unit according to Modification 1, equivalent to FIG. 11. FIG. 15 is a view of an antenna unit according to Modification 2, equivalent to FIG. 10. FIG. 16 is a view of a touch sensor, a component of an antenna unit according to Modification 3, equivalent to FIG. 4. Fig. 17 is a partially enlarged view of part XVII shown in Fig. 16. Fig. 18 is a view of an antenna unit according to Modification 4, which corresponds to Fig. 7. Fig. 19 is a view of an antenna unit according to Modification 5, which corresponds to Fig. 7.

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following description of the embodiments is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0015] In the following description, for convenience of explanation, in the embodiment of the present disclosure, the X direction from the left side of the paper to the diagonally upper right of the paper in Fig. 1 is defined as the "first direction." The Y direction from the bottom of the paper to the diagonally upper left of the paper in Fig. 1 is defined as the "second direction." The Z direction from the top of the paper to the bottom of the paper in Fig. 1 (a direction perpendicular to each of the first direction and the second direction) is defined as the "third direction."

[0016] 1 shows an entire antenna unit 1 according to an embodiment of the present disclosure. The antenna unit 1 illustrated in this embodiment includes a touch sensor 10 (see FIGS. 2 and 4) as a main component.

[0017] In the following description, the side on which an operation surface 2b (see FIG. 2) of a cover member 2 (described later) is located in the third direction Z is defined as the "upper side" of the antenna unit 1, and the opposite side (the side on which a display unit 9 (described later) is located) is defined as the "lower side" of the antenna unit 1, and the positional relationship of the elements constituting the antenna unit 1 is defined accordingly. This positional relationship is unrelated to the orientation of the antenna unit 1 or a product to which the antenna unit 1 is applied in actual use.

[0018] (Touch Sensor) The touch sensor 10 is a capacitance-type sensor-type input device. The touch sensor 10 is applied to, for example, in-vehicle devices such as car navigation systems, display devices for personal computers, mobile phones, personal digital assistants, portable game machines, copy machines, ticket vending machines, automated teller machines, and watches.

[0019] (Flexible Wiring Board) As shown in Figures 1 and 4, the antenna unit 1 is provided with flexible wiring boards 8 and 37. The flexible wiring boards 8 and 37 are configured to be flexible and to maintain their electrical characteristics even when deformed. The flexible wiring boards 8 and 37 are made of a flexible insulating film such as PI (polyimide), PET (polyethylene terephthalate), or PEN (polyethylene naphthalate). Note that, for convenience of illustration, the flexible wiring board 37 is omitted in Figure 1. Also, for convenience of illustration, the flexible wiring boards 8 and 37 are shown by phantom lines in Figure 4.

[0020] Flexible wiring board 8 is attached to a peripheral portion of a first substrate 3 (described later) located on the lower side of the paper in Fig. 4. Flexible wiring board 37 is attached to a peripheral portion of a first substrate 3 (described later) located on the left side of the paper in Fig. 4. In this embodiment, flexible wiring board 8 and flexible wiring board 37 are not electrically connected to each other. However, flexible wiring board 8 and flexible wiring board 37 may be electrically connected to each other.

[0021] (Cover Member) As shown in Fig. 2, the antenna unit 1 includes a cover member 2 having optical transparency. The cover member 2 is made of, for example, a cover glass or a plastic cover lens. The cover member 2 is formed, for example, in the shape of a rectangular plate in a plan view. The cover member 2 is fixed to a second layer 5 (see Fig. 3) of a first substrate 3, which will be described later. Note that, for convenience of illustration, the cover member 2 is omitted from Figs. 8 to 12.

[0022] A substantially frame-shaped decorative portion 2a is formed on the periphery of the underside of the cover member 2 using a dark color such as black, for example, by screen printing. The rectangular area inside this decorative portion 2a serves as a light-transmitting view area. That is, the user can obtain visual information from the display unit 9, which will be described later, through this view area. The upper surface of the cover member 2 in the view area serves as an operation surface 2b of the touch sensor 10, which the user's fingers come into contact with when performing a touch operation.

[0023] (First Substrate) As shown in Figures 2 to 4, the antenna unit 1 includes a first substrate 3. The first substrate 3 is transparent. The first substrate 3 is formed in a substantially rectangular shape in a plan view. The thickness of the first substrate 3 is, for example, 200 µm or more and 300 µm or less (0.2 mm or more and 0.3 mm or less).

[0024] As shown in FIG. 3, the first substrate 3 has a first layer 4 and a second layer 5 .

[0025] The first layer 4 is made of a transparent resin material, such as polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin polymer (COP), or cycloolefin copolymer (COC).

[0026] The second layer 5 is laminated on the upper side of the first layer 4. The second layer 5 is a layer for forming a plurality of grooves 6, which will be described later. The second layer 5 is made of an insulating and transparent resin material. The thickness of the second layer 5 is formed to be greater than the depth of the grooves 6, which will be described later.

[0027] A plurality of grooves 6 are provided on the upper surface 3a of the first substrate 3 (the surface of the second layer 5) (see FIG. 6). Each groove 6 has a bottom that is recessed from the upper surface 3a in the third direction Z (the thickness direction of the first substrate 3). The depth of each groove 6 is set to, for example, 0.8 μm or more and 4.0 μm or less. Although not shown, a plurality of grooves 6 are also provided on the lower surface 3b of the first substrate 3.

[0028] (Adhesive Layer) As shown in FIG. 2, the antenna unit 1 includes adhesive layers 7, 7. The adhesive layer 7 is laminated between the cover member 2 and the first substrate 3. The adhesive layer 7 is also laminated between the first substrate 3 and a display unit 9 (described later). The adhesive layer 7 is an optically transparent adhesive (OCA: Optical Clear Adhesive). The thickness of the adhesive layer 7 is, for example, 25 μm or more and 250 μm or less. Note that, for convenience of illustration, the adhesive layer 7 is omitted from FIGS. 8 to 12.

[0029] 2, a display unit 9 is provided on the lower side of the first substrate 3. The display unit 9 is laminated on the lower side of the first substrate 3 via an adhesive layer 7.

[0030] The display unit 9 has a display main body 9a and a first conductor 41 (conductor 40). Examples of the display main body 9a include a liquid crystal display (LCD) or an organic electroluminescence (EL) display device. The thickness of the display main body 9a is, for example, 1 cm or less. Specifically, the thickness of the display main body 9a is 0.5 mm or more and 5.0 mm or less. Details of the first conductor 41 will be described later.

[0031] 4, the touch sensor 10 is provided with an active area A and a non-active area B. The active area A has a rectangular shape in a plan view. The non-active area B has a rectangular frame shape. The non-active area B is arranged so as to surround the periphery of the active area A in a plan view.

[0032] (Sensor Electrode) The antenna unit 1 includes a plurality of capacitance-type sensor electrodes. As shown in Fig. 4, the plurality of sensor electrodes are configured by a plurality of transmitting electrodes 11 and a plurality of receiving electrodes 12 (a plurality of electrodes).

[0033] The plurality of transmitting electrodes 11 and the plurality of receiving electrodes 12 are arranged on the first substrate 3 at positions corresponding to the active area A. The touch sensor 10 is capable of detecting a touch operation by a user's finger (detection target) that is in contact with the operation surface 2 b, through the plurality of transmitting electrodes 11 and the plurality of receiving electrodes 12 located in the active area A.

[0034] Each transmitting electrode 11 is connected to a drive circuit of an IC device (not shown) via a flexible wiring board 8. Each transmitting electrode 11 is configured to radiate an electric field to the surroundings by the drive circuit. A predetermined pulse potential for radiating an electric field is applied to the multiple transmitting electrodes 11.

[0035] Each receiving electrode 12 is connected to a detection circuit of an IC device (not shown) via a flexible wiring board 8. Each receiving electrode 12 is configured to detect an electric field radiated from each transmitting electrode 11. A predetermined potential is constantly applied to the multiple receiving electrodes 12 in order to detect the electric fields radiated from the multiple transmitting electrodes 11.

[0036] 4, the transmitting electrodes 11 and the receiving electrodes 12 are arranged to intersect (orthogonal to) each other in a plan view. A node is formed in the area where each transmitting electrode 11 and each receiving electrode 12 overlap. The node is configured as an area where electrostatic capacitance can be generated.

[0037] The plurality of transmitting electrodes 11 are provided on the lower surface 3b of the first substrate 3 (see FIG. 2). As shown in FIG. 4, each transmitting electrode 11 extends along the second direction Y. The plurality of transmitting electrodes 11 are arranged at intervals from one another in the first direction X.

[0038] The plurality of receiving electrodes 12 are provided on the upper surface 3a of the first substrate 3 (see FIG. 2). That is, the plurality of receiving electrodes 12 are arranged on the first substrate 3 on the visible side of the touch sensor 10 (the side on which the operation surface 2b of the cover member 2 is located). The plurality of receiving electrodes 12 are insulated from the plurality of transmitting electrodes 11 via the first substrate 3.

[0039] As shown in Fig. 4 , each receiving electrode 12 extends along a first direction X. The multiple receiving electrodes 12 are arranged at intervals from one another in a second direction Y. Note that in Figs. 7 and 8 , the receiving electrodes 12, 12 adjacent to a radiating portion 31 (first radiating portion 32a and second radiating portion 32b) described later are referred to as a first electrode 12a and a second electrode 12b for convenience of explanation.

[0040] 18 and 19, for convenience of explanation, the receiving electrodes 12 are referred to as the fourth electrode 12d, the third electrode 12c, the first electrode 12a, the second electrode 12b, and the fifth electrode 12e, in that order from the top of the drawing. That is, the third electrode 12c is located on the opposite side of the second electrode 12b from the first electrode 12a. The fourth electrode 12d is located on the opposite side of the first electrode 12a from the third electrode 12c. The fifth electrode 12e is located on the opposite side of the first electrode 12b from the second electrode 12b.

[0041] 5 , the sensor electrode includes a mesh pattern 13. The mesh pattern 13 is formed so as to have a plurality of cells 14 arranged side by side, each cell 14 being made up of a plurality of conductive wires 20. The mesh pattern 13 constituting each transmitting electrode 11 and the mesh pattern 13 constituting each receiving electrode 12 are arranged so as to overlap each other in the thickness direction of the first substrate 3.

[0042] Each conductive line 20 is made of a thin metal wire having electrical conductivity. The plurality of conductive lines 20 extend obliquely with respect to each of the first direction X and the second direction Y. The line width of each conductive line 20 is, for example, 1 μm or more and 20 μm or less. The interval between adjacent conductive lines 20, 20 is, for example, 20 μm or more and 500 μm or less.

[0043] The cell 14 is composed of a plurality of conductive wires 20 that are electrically connected to one another. The cell 14 has a quadrilateral shape. In this embodiment, the quadrilateral shape is a rhombus. Although not shown, the quadrilateral shape may also be a square or a rectangle.

[0044] (Cross-sectional structure of conductive wire) Next, a description will be given of the cross-sectional structure of the conductive wire 20. Each conductive wire 20 includes a conductive metal buried in each groove 6. As shown in Fig. 6, each conductive wire 20 is composed of an adhesion layer 21, a seed layer 22, a conductive layer 23, and a blackening layer 24.

[0045] The adhesion layer 21 is an element for ensuring adhesion of the seed layer 22 to the groove portion 6. The adhesion layer 21 is, for example, a metal layer composed of a metal nitride or metal oxide containing at least one metal selected from the group consisting of Ti, Ni, Al, V, W, Ta, Si, Cr, Ag, Mo, Cu, and Zn. The adhesion layer 21 may be a single layer or a laminate in which multiple layers with different compositions are stacked. The adhesion layer 21 is stacked in the form of a thin film on the groove portion 6 by, for example, vapor deposition or sputtering.

[0046] The seed layer 22 has a function of bonding the conductive layer 23 to the adhesion layer 21. Specifically, the seed layer 22 functions as a cathode for depositing a plating solution containing copper (Cu) or the like, which will be described later, on the adhesion layer 21 in this embodiment, during, for example, an electroplating process for forming the conductive layer 23. The seed layer 22 is deposited as a thin film on the adhesion layer 21 by, for example, vapor deposition or sputtering.

[0047] The conductive layer 23 is made of a conductive metal such as copper (Cu). The conductive layer 23 is formed, for example, by electroplating. When the electroplating is performed, the seed layer 22 and the conductive layer 23 are formed integrally. This makes it impossible to distinguish the interface between the seed layer 22 and the conductive layer 23. Note that although copper (Cu) is suitable as the main component of the plating solution used in the electroplating, metals other than copper (for example, silver or gold) may also be included.

[0048] The blackening layer 24 has the function of making the conductive wire 20 less visible when viewed from above the antenna unit 1 (or the touch sensor 10). The blackening layer 24 is laminated on the surface of the conductive layer 23. The blackening layer 24 is formed by substituting palladium for copper crystal grains located at the boundaries between copper crystal grains located on the surface of the conductive layer 23 (blackening treatment). The thickness of the blackening layer 24 is, for example, 7 nm or more and 10 nm or less.

[0049] 4, the antenna unit 1 includes a plurality of wiring sections. The wiring sections are elements for electrically connecting the plurality of transmitting electrodes 11 and the plurality of receiving electrodes 12 to an IC device (not shown) (mainly the drive circuit and detection circuit described above). Each wiring section is made up of at least one conductive line 20.

[0050] 4, the plurality of wiring portions are configured by a plurality of first wiring portions 25 and a plurality of second wiring portions 26. The plurality of first wiring portions 25 and the plurality of second wiring portions 26 are arranged in the inactive area B.

[0051] The first wiring portions 25 and the second wiring portions 26 are arranged at positions that overlap with the decorative portion 2a (see FIG. 2) when viewed from the side where the operation surface 2b is located. That is, the decorative portion 2a prevents the first wiring portions 25 and the second wiring portions 26 from being visible from the side where the operation surface 2b is located.

[0052] The multiple first wiring portions 25 are arranged (not shown) on the lower surface 3b of the first substrate 3, similar to the multiple transmitting electrodes 11. Each first wiring portion 25 is electrically connected to each transmitting electrode 11. As shown in Fig. 4 , one end of each first wiring portion 25 is electrically connected to an end of each transmitting electrode 11 located on the lower side of the paper surface of Fig. 4 .

[0053] The multiple second wiring portions 26 are arranged (not shown) on the upper surface 3a of the first substrate 3, similar to the multiple receiving electrodes 12. Each second wiring portion 26 is electrically connected to a corresponding receiving electrode 12. As shown in Fig. 4 , one end of each second wiring portion 26 is electrically connected to an end of each receiving electrode 12 located on the right side of the paper surface of Fig. 4 .

[0054] 4, a pad 27 is provided at the other end of each wiring portion. Each pad 27 is made of a conductive wire 20 similar to the conductive wire 20. Each pad 27 is electrically connected to the flexible wiring board 8 via, for example, an anisotropic conductive film (ACF).

[0055] 4 and 8, the antenna unit 1 of this embodiment includes one monopole antenna 30. The antenna unit 1 may include a plurality of monopole antennas 30.

[0056] The monopole antenna 30 is applicable to devices that perform communication at frequencies between 3 GHz and 5 GHz. The communication frequency of the monopole antenna 30 is a predetermined frequency band, for example, between 0.5 GHz and 30 GHz. Specifically, the communication frequency of the monopole antenna 30 is the 700 MHz band, 800 MHz band, or 900 MHz band, the 1.5 GHz band, the 1.7 GHz band, the 2 GHz band, the 2.4 GHz band, the 3.4 GHz band or 3.5 GHz band, the 3.7 GHz band or 4.5 GHz band, the 5.0 GHz band, the 6.0 GHz band, or the 28 GHz band.

[0057] The monopole antenna 30 is disposed on the upper surface 3a of the first substrate 3 (see FIGS. 9 to 11). That is, the monopole antenna 30 is disposed on the same surface of the first substrate 3 as the surface on which the multiple receiving electrodes 12 are located.

[0058] Although not shown, the monopole antenna 30 is configured by a mesh pattern 13 made up of a plurality of conductive wires 20, similar to the sensor electrode.

[0059] (Radiating Section) The antenna unit 1 has a radiating section 31. The radiating section 31 has a function of generating radio waves in space or a function of receiving radio waves from space. As shown in Figures 7 and 8, the radiating section 31 illustrated in this embodiment is composed of a first radiating section 32a and a second radiating section 32b. Each of the first and second radiating sections 32a, 32b has a first electric potential.

[0060] The first radiating portion 32a is configured to support, for example, a communication frequency in the 2.4 GHz band. As shown in Figures 7 and 8, the first radiating portion 32a extends along a first direction X. The first radiating portion 32a is disposed in a second direction Y at an interval from each of the adjacent first electrodes 12a (receiving electrodes 12) and second electrodes 12b (receiving electrodes 12). When the wavelength of the electric field corresponding to the communication frequency in the 2.4 GHz band is defined as "λ1," the length of the first radiating portion 32a in the first direction X is set to ¼ of λ1.

[0061] This prevents the first radiating portion 32a from overlapping with the first electrode 12a or the second electrode 12b, making it less likely that the first electrode 12a or the second electrode 12b will impede the function of the first radiating portion 32a as an antenna.

[0062] In addition, the first electrode 12a or the second electrode 12b can be disposed at the edge of the view area, thereby widening the sensing area of ​​the touch sensor 10.

[0063] 7 and 8, each of the first and second radiating portions 32a, 32b has a power supply portion 34. The power supply portion 34 is configured as an end portion of the first radiating portion 32a located on the left side of the paper surfaces of FIGS. 7 and 8 (an end portion located closer to the peripheral edge of the first substrate 3). The power supply portion 34 is electrically connected to a flexible wiring board 37. A transmission wave is supplied to the power supply portion 34 from a power supply device (not shown) via a communication device through the flexible wiring board 37.

[0064] The second radiating portion 32b is configured to support a communication frequency different from the communication frequency of the first radiating portion 32a, for example, the 5.0 GHz band.

[0065] The second radiating portion 32b is formed in a substantially L-shape. Specifically, the second radiating portion 32b is configured to branch in the second direction Y from a midpoint of the first radiating portion 32a located closer to the power supply portion 34 and extend from the branched portion toward the first direction X. The second radiating portion 32b is disposed so as to be located between the adjacent first electrodes 12a and second electrodes 12b in the second direction Y. When the wavelength of the electric field corresponding to the communication frequency of the 5.0 GHz band is defined as "λ2," the total length of the second radiating portion 32b is set to one-quarter of λ2.

[0066] As will be described in Modifications 4 and 5 below, the second radiating portion 32b may extend from the first branch electrode portion 33a or the second branch electrode portion 33b.

[0067] 7 and 8, the antenna unit 1 has first and second branch electrode portions 33a and 33b. Each of the first and second branch electrode portions 33a and 33b is electrically connected to a conductor 40, which will be described later.

[0068] The first branch electrode portion 33a is located to the right as viewed from the radiation portion 31. Specifically, the first branch electrode portion 33a is arranged on the side of the first radiation portion 32a in the second direction Y. The second branch electrode portion 33b is located to the left as viewed from the radiation portion 31. Specifically, the second branch electrode portion 33b is arranged on the side opposite to the second direction Y in the second radiation portion 32b.

[0069] The first branch electrode portion 33a and the second branch electrode portion 33b extend in a direction different from the first direction X. That is, the first branch electrode portion 33a is located on the first electrode 12a side as viewed from the first radiating portion 32a, and extends in a direction different from the first direction X. The second branch electrode portion 33b is located on the second electrode 12b side as viewed from the first radiating portion 32a, and extends in a direction different from the first direction X.

[0070] Each of the first and second branch electrode portions 33 a, 33 b has a second potential that is lower than the potential (first potential) of the radiation portion 31. The second potential is, for example, ground potential (GND). Note that the second potential is not limited to ground potential (GND) as long as it is lower than the potential of the radiation portion.

[0071] Each of the first and second branch electrode portions 33a, 33b has a power supply portion 35. The power supply portion 35 is configured as an end portion of each of the first and second branch electrode portions 33a, 33b located closer to the first radiation portion 32a. The power supply portion 35 is electrically connected to a flexible wiring board 37. The power supply portion 35 is set to a second potential by a power supply device (not shown).

[0072] 7 and 8, the monopole antenna 30 includes a short portion 36. The short portion 36 has a function of adjusting impedance matching in the monopole antenna 30. The short portion 36 has an inverted L shape in a plan view.

[0073] The short-circuit portion 36 is configured to electrically connect the radiation portion 31 (either the first or second radiation portion 32a, 32b) to either the first or second branch electrode portion 33a, 33b. The short-circuit portion 36 in this embodiment is configured to electrically connect the first radiation portion 32a to the second branch electrode portion 33b.

[0074] 2 and 8 to 12, the antenna unit 1 includes a conductor 40. The conductor 40 in this embodiment has a first conductor 41. For convenience of illustration, the display main body 9a is omitted from illustration in FIGS.

[0075] The first conductor 41 in this embodiment is configured as one element of the display unit 9 (see FIG. 2 ). The first conductor 41 is located below the monopole antenna 30 and is spaced apart from the monopole antenna 30. Specifically, the first conductor 41 is disposed at a position spaced apart from the plurality of sensor electrodes and the monopole antenna 30 in the third direction Z. Furthermore, the first conductor 41 overlaps with the radiation unit 31 in a plan view.

[0076] The first conductor 41 has a bottom plate portion 42 and a wall portion 43. The bottom plate portion 42 and the wall portion 43 are each made of, for example, a metal material. The bottom plate portion 42 and the wall portion 43 are each formed in a substantially plate shape.

[0077] The first conductor 41 has a second potential that is lower than the first potential of the radiation portion 31. In this embodiment, the first conductor 41 is electrically connected to the wall portion 43 and a first connection portion 45, which will be described later. As a result, the first conductor 41 has the same potential as the first and second branch electrode portions 33 a, 33 b.

[0078] 2 and 8 to 12, the bottom plate portion 42 of the first conductor 41 includes a first opposing surface 44. That is, the first conductor 41 includes the first opposing surface 44. The first opposing surface 44 faces the monopole antenna 30 in the up-down direction (third direction Z). Specifically, the first opposing surface 44 is configured as a surface of the bottom plate portion 42 that faces the first substrate 3 in the third direction Z. The first opposing surface 44 is disposed so as to overlap with the monopole antenna 30 in a plan view.

[0079] 9 to 12 , the first opposing surface 44 is disposed at a first distance D1 from the monopole antenna 30 in the third direction Z. In this embodiment, the first distance D1 corresponds to the thickness of the display main body 9a constituting the display unit 9 (the length of the display main body 9a in the third direction Z). That is, the first distance D1 is, for example, not less than 0.5 mm and not more than 5.0 mm.

[0080] 8 to 12, the antenna unit 1 includes a plurality of (two in the illustrated example) first connection portions 45. Each first connection portion 45 is a member for electrically connecting the first and second branch electrode portions 33a, 33b to the first conductor 41, respectively.

[0081] Each first connection portion 45 is disposed between the first and second branch electrode portions 33 a, 33 b and the wall portion 43 of the first conductor 41 in the third direction Z. Each first connection portion 45 is made of, for example, a metal material. Each first connection portion 45 is formed in a substantially plate-like shape.

[0082] The upper end of each first connecting portion 45 is attached to the first and second branch electrode portions 33 a, 33 b, respectively, by, for example, solder, conductive adhesive, silver paste, or conductive tape, and the lower end of each first connecting portion 45 is attached to the wall portion 43 of the first conductor 41 by welding, screwing, or the like.

[0083] Furthermore, when the antenna unit 1 is electrically connected to an IC device (not shown), the first conductor 41 and the first branch electrode portion 70a or the second branch electrode portion 70b may be electrically connected within the IC device. Furthermore, the first conductor 41 and the first branch electrode portion 70a or the second branch electrode portion 70b may each be set to a ground potential separately. In this case, the first conductor 41 and the first branch electrode portion 70a or the second branch electrode portion 70b are electrically connected via the ground.

[0084] [Effects of the Embodiment] As described above, the radiation portion 31 is separated from each of the adjacent first electrodes 12a and second electrodes 12b in the second direction Y. That is, the radiation portion 31 (or a part thereof) is located within the active area A. As a result, in the touch sensor 10, it is possible to relatively reduce the region in the inactive area B where the monopole antenna 30 is located (in this embodiment, the width corresponding to the dimension b1 shown in FIG. 4 ). This optimizes the positional relationship between the multiple receiving electrodes 12 and the monopole antenna 30. Specifically, the antenna unit 1 according to this embodiment allows the frame of the inactive area B of the touch sensor 10 to be narrowed.

[0085] Furthermore, in the planar direction of the upper surface 3 a of the first substrate 3 (i.e., the planar direction of the plane formed by the first direction X and the second direction Y), an electric field E1 is generated between each of the first and second radiating portions 32 a, 32 b and each of the first and second branch electrode portions 33 a, 33 b (see FIG. 7 ). Meanwhile, a first conductor 41 (conductor 40) having a second potential lower than the first potential of the radiating portion 31 is provided at a position (position away in the third direction Z) below the first electrode 12 a, the second electrode 12 b, and the monopole antenna 30. This first conductor 41 generates an electric field E2 between the radiating portion 31 (first radiating portion 32 a in FIG. 11 ) and the first conductor 41 in the third direction Z (see FIG. 11 ). The path of the electric field E2 shown in FIG. 11 is formed along a different direction from the path of the electric field E1 shown in FIG. 7 .

[0086] By optimizing the positional relationship between the multiple receiving electrodes 12 and the monopole antenna 30 as described above, each of the first and second electrodes 12a, 12b, particularly those facing the first radiating portion 32a in the second direction Y, is positioned so as to block the path of the electric field E1 in the planar direction of the upper surface 3a of the first substrate 3 (see FIG. 7 ). This makes the electric field E1 more likely to impinge on the multiple conductive wires 20 constituting each of the first and second electrodes 12a, 12b. A portion of the electric field E1 that impinges on the conductive wires 20 is likely to deviate from the path of the electric field E1. Specifically, when the portion of the electric field E1 impinges on the conductive wires 20, it tends to be directed upward or downward relative to the upper surface 3a. As a result, the electric field E1 is generally disrupted, making it difficult for the monopole antenna 30 to generate radio waves normally. In other words, partial defects may occur in the electric field E1.

[0087] In contrast, as shown in FIG. 11 , each of the first and second electrodes 12a, 12b located near the first radiating portion 32a acts not to block the path of the electric field E2 in the third direction Z. Specifically, as shown in FIG. 13 , because each conductive wire 20 constituting the receiving electrode 12 (or transmitting electrode 11) is formed of a thin metal wire, the electric field E2 travels through areas where the conductive wires 20 are not located (between the conductive wires 20, 20 in this embodiment) and heads toward the first radiating portion 32a (or the first conductor 41) along the normal path of the electric field E2. In other words, the electric field E2 is less susceptible to the influence of the receiving electrode 12 (or the transmitting electrode 11). As a result, the electric field E2 is not generally disturbed, and radio waves are normally generated from the monopole antenna 30. Furthermore, the electric field E2 acts to compensate for the partial loss of the electric field E1 described above. This ensures the antenna characteristics of the monopole antenna 30.

[0088] Therefore, in the antenna unit 1 according to the embodiment of the present disclosure, even if the positional relationship between the multiple receiving electrodes 12 and the monopole antenna 30 is optimized, the antenna characteristics of the monopole antenna 30 can be ensured.

[0089] According to the results of a predetermined electromagnetic field simulation (when the operating frequencies were set to 2.5 GHz and 5.55 GHz), the maximum value of the antenna directivity (2.5 GHz) of the first radiating portion 32a in the antenna unit 1 was +1 dBi. Also, the maximum value of the antenna directivity (5.55 GHz) of the second radiating portion 32b was +2.9 dBi.

[0090] Each receiving electrode 12 also includes a plurality of conductive wires 20. The conductive wires 20 are spaced apart from one another. Each receiving electrode 12 is configured with a mesh pattern 13 formed by arranging a plurality of cells 14 each including a plurality of conductive wires 20. With this configuration, the electric field E2 passes through the conductive wires 20 constituting the receiving electrode 12 (particularly the first and second electrodes 12a and 12b) and travels toward the first radiating portion 32a (or the first conductor 41) along a normal path of the electric field E2. This ensures the antenna characteristics of the monopole antenna 30, as described above. Furthermore, because the receiving electrode 12 is configured with the mesh pattern 13, the conductive wires 20 are less noticeable. As a result, the visibility of the antenna unit 1 (or the touch sensor 10) can be improved.

[0091] The first conductor 41 also includes a first opposing surface 44 that faces the monopole antenna 30 in the vertical direction. The first opposing surface 44 is disposed so as to overlap the monopole antenna 30 in a plan view, and is disposed with a first distance D1 from the monopole antenna 30 in the vertical direction (third direction Z). Preferably, the first distance D1 is 0.5 mm or more and 5.0 mm or less. By disposing the first opposing surface 44 so as to overlap the monopole antenna 30, the path of the electric field E2 generated between the first radiating portion 32a and the first conductor 41 is easily aligned along the third direction Z. As a result, the antenna characteristics of the monopole antenna 30 are ensured as described above. Furthermore, by setting the first distance D1, the electric field E2 is more likely to be generated from the monopole antenna 30 in response to radio waves (such as microwaves) used in wireless communication compliant with the Wi-Fi (registered trademark) standard. In other words, the first distance D1 allows antenna characteristics appropriate for the type of radio waves to be transmitted.

[0092] Furthermore, first connecting portions 45 are provided between each of the first and second branch electrode portions 33a, 33b and the first conductor 41 (wall portion 43 in this embodiment). The first connecting portions 45 cause the first conductor 41 to have the same potential as the first and second branch electrode portions 33a, 33b (i.e., the second potential). The first connecting portions 45 make it easy to set the first conductor 41 to the second potential lower than the first potential of the radiation portion 31. Furthermore, providing the first connecting portions 45 improves the reliability of the electrical connection between each of the first and second branch electrode portions 33a, 33b and the first conductor 41. As a result, the antenna characteristics of the monopole antenna 30 can be ensured.

[0093] The short-circuit portion 36 is configured to electrically connect the radiation portion 31 to either the first or second branch electrode portion 33 a, 33 b. This configuration allows the impedance matching of the monopole antenna 30 to be adjusted.

[0094] Furthermore, in this embodiment, the multiple receiving electrodes 12 and the monopole antenna 30 are all arranged on the same surface (top surface 3a) of the first substrate 3. Specifically, the first and second electrodes 12a, 12b and the monopole antenna 30 are all arranged on the top surface 3a of the first substrate 3. This eliminates the need to provide separate layers for forming the multiple receiving electrodes 12 and the monopole antenna 30. In other words, the number of laminated substrates constituting the antenna unit 1 can be reduced.

[0095] [First Modification of the Embodiment] In the above embodiment, both the plurality of receiving electrodes 12 and the monopole antenna 30 are disposed on the upper surface 3 a of the first substrate 3, but the present invention is not limited to this. For example, a configuration like the first modification shown in FIG. 14 may be used.

[0096] The antenna unit 1 according to the first modification shown in Fig. 14 includes a first substrate 3 and a second substrate 50. The second substrate 50 is stacked above the first substrate 3 (in the opposite direction to the third direction Z relative to the first substrate 3). Specifically, the second substrate 50 is stacked on the upper surface 3a of the first substrate 3 via an adhesive layer 7. Although not shown, a flexible wiring board 37 is attached to the second substrate 50. The specific configuration of the second substrate 50 is the same as that of the first substrate 3 of the above embodiment. The adhesive layer 7 is also the same as that of the above embodiment.

[0097] Similar to the above embodiment, the plurality of receiving electrodes 12 are arranged on the upper surface 3a of the first substrate 3. In contrast, the monopole antenna 30 is arranged on the upper surface 50a of the second substrate 50. The specific configurations of the plurality of receiving electrodes 12 and the monopole antenna 30 are similar to those of the above embodiment. Although not shown, the cover member 2 described in the above embodiment is laminated on the upper surface 50a side of the second substrate 50 via the adhesive layer 7.

[0098] Here, the thickness of the second substrate 50 (200 μm or more and 300 μm or less) and the thickness of the adhesive layer 7 (25 μm or more and 250 μm or less) are both extremely small compared to the overall thickness of the antenna unit 1. Therefore, the antenna unit 1 according to Modification 1 can be considered to be the same as the configuration in which a plurality of receiving electrodes 12 and a monopole antenna 30 are arranged on the upper surface 3 a (the configuration shown in the above embodiment). That is, the first distance D1 in Modification 1 is substantially the same as the first distance D1 shown in the above embodiment. Therefore, the antenna unit 1 according to Modification 1 can also achieve the same effects as the above embodiment.

[0099] In this modification, the second substrate 50, on which the monopole antenna 30 is previously arranged, is laminated on the first substrate 3, on which the plurality of receiving electrodes 12 are previously arranged, using the adhesive layer 7. That is, in this modification, the manufacturing process of the antenna unit 1 can be simplified.

[0100] [Second Modification of the Embodiment] In the above-described embodiment, the conductor 40 is formed of the first conductor 41, but the present invention is not limited to this. For example, as in a second modification shown in Fig. 15 , the conductor 40 may have the first conductor 41 and further have a second conductor 61. Note that in the second modification as well, the first opposing surface 44 of the first conductor 41 is disposed so as to overlap with the monopole antenna 30 in a plan view, and is disposed with a first distance D1 from the monopole antenna 30 in the third direction Z.

[0101] 15 , the antenna unit 1 according to the second modification includes a third substrate 60. The third substrate 60 is laminated on the lower surface 3b side of the first substrate 3 via an adhesive layer 7. The specific configuration of the third substrate 60 is similar to that of the first substrate 3 of the above embodiment.

[0102] The second conductor 61 is disposed on the upper surface of the third substrate 60. Although not shown, the second conductor 61 includes a mesh pattern 13 made up of a plurality of conductive wires 20, similar to the sensor electrode.

[0103] The second conductor 61 overlaps with the monopole antenna 30 in a plan view, but is spaced apart from the monopole antenna 30. The second conductor 61 includes a second opposing surface 63 that faces the monopole antenna 30 in the up-down direction (third direction Z). The second distance D2 is smaller than the first distance D1. Preferably, the second distance D2 is 1 / 20 of the first distance D1. Specifically, the second distance D2 is 0.2 mm or more and 0.3 mm or less.

[0104] In this modification, the second distance D2 makes it easier for an electric field to be generated from the radiation portion 31 of the monopole antenna 30 in response to radio waves having a wavelength equal to or less than 1 / 10 of that of microwaves (radio waves in the millimeter wave band, terahertz band, etc.). That is, by providing the second conductor 61 and the second distance D2, it is possible to obtain antenna characteristics different from those suited to the first conductor 41 and the first distance D1.

[0105] The antenna unit 1 according to the second modification also includes second connection portions 62, 62. Each second connection portion 62 is an element for electrically connecting each of the first and second branch electrode portions 33 a, 33 b to each of the second conductors 61. Each second connection portion 62 is disposed between each of the first and second branch electrode portions 33 a, 33 b and each of the second conductors 61. Each second conductor 61 is set to the same potential as each of the first and second branch electrode portions 33 a, 33 b by each of the second connection portions 62. By providing this second connection portion 62, it becomes easy to set the second conductor 61 to a second potential that is lower than the first potential of the radiation portion 31.

[0106] In the above-described modified example 2, the conductor 40 is configured to include the first conductor 41 and the second conductor 61, but the present invention is not limited to this. That is, as a further modified example of modified example 2, the conductor 40 may be configured to include only the second conductor 61. In this configuration, the above-described unique operational effect can be achieved by providing the second conductor 61 and the second distance D2.

[0107] [Third Modification of the Embodiment] As a third modification of the embodiment, the monopole antenna 30 may be modified to the configuration illustrated in Figures 16 and 17. The monopole antenna 30 of the third modification differs mainly from the first and second branch electrode portions 33a and 33b shown in the above embodiment in the configurations of the first and second branch electrode portions 70a and 70b described below. Note that in the monopole antenna 30 of the third modification, the main configurations of the first radiating portion 32a, the second radiating portion 32b, and the short portion 36 are the same as those in the above embodiment.

[0108] As shown in FIG. 17, in the monopole antenna 30 of the third modification, a portion of each of the first and second branch electrode portions 70a, 70b is bent in the direction opposite to the first direction X (toward the left side of the paper in FIG. 7).

[0109] The first branch electrode portion 70a includes a first bent portion 71a and a first main body portion 72a.

[0110] The first bent portion 71a extends from one end of the first bent portion 71a (the end located on the left side of the paper in FIG. 7 ) in the first direction X. The first bent portion 71a has a first power supply portion 73a. The first power supply portion 73a is located at one end of the first bent portion 71a (the end located on the left side of the paper in FIG. 7 ).

[0111] The first main body portion 72a is integrally formed with the first bent portion 71a. The first main body portion 72a extends from the other end of the first bent portion 71a (the end located on the right side of the paper in FIG. 7 ) in a direction intersecting the first direction X (the second direction Y in this modified example). Note that in the configuration illustrated in FIG. 17 , the length of the first main body portion 72a in the second direction Y is longer than the length of the first bent portion 71a in the first direction X.

[0112] The second branch electrode portion 70b includes a second bent portion 71b and a second main body portion 72b.

[0113] The second bent portion 71b extends from one end of the second bent portion 71b (the end located on the left side of the paper in FIG. 7 ) in the first direction X. The second bent portion 71b has a second power supply portion 73b. The second power supply portion 73b is located at one end of the second bent portion 71b (the end located on the left side of the paper in FIG. 7 ).

[0114] The second main body portion 72b is formed integrally with the second bent portion 71b. The second main body portion 72b extends from the other end of the second bent portion 71b (the end located on the right side of the paper in FIG. 7 ) in a direction intersecting the first direction X (the opposite direction to the second direction Y in this modified example). A short portion 36 is connected to a middle portion of the second main body portion 72b. Note that in the configuration illustrated in FIG. 17 , the length of the second main body portion 72b in the second direction Y is longer than the length of the second bent portion 71b in the first direction X.

[0115] In this modification, the combined length of the first bent portion 71a in the extension direction and the first main body portion 72a in the extension direction is approximately the same as the overall length of the first branch electrode portion 33a in the extension direction shown in the above embodiment. Similarly, the combined length of the second bent portion 71b in the extension direction and the second main body portion 72b in the extension direction is approximately the same as the overall length of the second branch electrode portion 33b in the extension direction shown in the above embodiment. That is, the lengths of the first main body portion 72a and the second main body portion 72b are relatively shorter than the respective first branch electrode portions 33a and 33b in the above embodiment. Therefore, the overall length of the monopole antenna 30 in the second direction Y in the modification 3 is shorter than the overall length of the monopole antenna 30 in the second direction Y shown in the above embodiment. As a result, as shown in FIG. 16 , the antenna unit 1 in modification 3 allows multiple (three in the illustrated example) monopole antennas 30 to be arranged side by side along the second direction Y in the inactive area B. This allows the antenna function (for example, reception sensitivity) of the antenna unit 1 to be further improved.

[0116] [Fourth Modification of the Embodiment] As a fourth modification of the embodiment, the monopole antenna 30 may be modified to the configuration illustrated in Fig. 18. Unlike the monopole antenna 30 according to the above embodiment, in the monopole antenna 30 of the fourth modification, the second radiating portion 32b does not extend from the first radiating portion 32a but extends from the first branch electrode portion 33a. Note that, in the monopole antenna 30 of the fourth modification, description of the same configuration as in the above embodiment will be omitted.

[0117] By extending the second radiating portion 32b from the first branch electrode portion 33a, the second radiating portion 32b can be provided at a position separated from the first radiating portion 32a. Therefore, only the first radiating portion 32a can be disposed between the first electrode 12a and the second electrode 12b, rather than both the first radiating portion 32a and the second radiating portion 32b.

[0118] Therefore, the distance between the first radiating portion 32a and the first electrode 12a or the distance between the first radiating portion 32a and the second electrode 12b can be increased. This improves the radiation efficiency of the first radiating portion 32a. Furthermore, the width of the first radiating portion 32a along the second direction Y can be increased. This allows a larger number of conductive wires 20 in the mesh pattern 13 within the first radiating portion 32a. This reduces the resistance of the first radiating portion 32a, further improving the radiation efficiency of the first radiating portion 32a. In other words, by extending the second radiating portion 32b from the first branch electrode portion 33a, the radiation efficiency of the first radiating portion 32a can be improved compared to when the second radiating portion 32b extends from the first radiating portion 32a.

[0119] Furthermore, the distance between the first electrode 12a and the second electrode 12b can be narrowed compared to when the first radiating portion 32a and the second radiating portion 32b are disposed between the first electrode 12a and the second electrode 12b. As described above, the touch sensor 10 can detect a touch operation by a user's finger (detection target) touching the operation surface 2b through the multiple receiving electrodes 12. Therefore, increasing the number of the multiple receiving electrodes 12 can improve the sensing efficiency of the touch sensor 10. Narrowing the distance between the first electrode 12a and the second electrode 12b can increase the number of the multiple receiving electrodes 12. Therefore, the sensing efficiency of the touch sensor 10 can be improved. That is, extending the second radiating portion 32b from the first branch electrode portion 33a can improve the sensing efficiency of the touch sensor 10 compared to when the second radiating portion 32b extends from the first radiating portion 32a.

[0120] Furthermore, the second radiating portion 32b is located between the first electrode 12a and the third electrode 12c in a plan view. This prevents the second radiating portion 32b from overlapping with the first electrode 12a or the third electrode 12c. This makes it less likely that the first electrode 12a or the third electrode 12c will impede the function of the second radiating portion 32b as an antenna.

[0121] Furthermore, the first electrode 12a or the third electrode 12c can be disposed at the edge of the view area, thereby widening the sensing area of ​​the touch sensor 10.

[0122] Furthermore, the second radiating portion 32b is shorter than the first radiating portion 32a. Specifically, the length of the second radiating portion 32b in the first direction X is shorter than the length of the first radiating portion 32a in the first direction X. As described above, the length of the second radiating portion 32b can be adjusted according to the communication frequency. This enables the monopole antenna 30 to communicate in multiple frequency bands.

[0123] The monopole antenna 30 according to the fourth modification further includes a third radiating portion 32c located between the third electrode 12c and the fourth electrode 12d in a plan view. The third radiating portion 32c is electrically connected to the first branch electrode portion 33a.

[0124] The length of the third radiating portion 32c in the first direction X is shorter than the length of the second radiating portion 32b in the first direction X. The length of the third radiating portion 32c can be adjusted according to the communication frequency. This enables the monopole antenna 30 to communicate in multiple frequency bands.

[0125] [Fifth Modification of the Embodiment] As a fifth modification of the embodiment, the monopole antenna 30 may be modified to the configuration illustrated in Fig. 19. In the monopole antenna 30 according to the fifth modification, the position of the third radiating portion 32c differs from the configuration illustrated in Fig. 18. In the monopole antenna 30 according to the fifth modification, the description of the same configuration as that of the fourth modification will be omitted. Note that the monopole antenna 30 according to the fifth modification does not include the short portion 36.

[0126] In the monopole antenna 30 according to the fifth modification, the third radiating portion 32c is located between the fifth electrode 12e and the second electrode 12b in a plan view. The third radiating portion 32c of the fifth modification is electrically connected to the second branch electrode portion 33b.

[0127] Furthermore, the third radiating portion 32c is shorter than the second radiating portion 32b. Specifically, the length of the third radiating portion 32c in the first direction X is shorter than the length of the second radiating portion 32b in the first direction X. As described above, the length of the third radiating portion 32c can be adjusted depending on the communication frequency. This enables the monopole antenna 30 to communicate in multiple frequency bands.

[0128] Other Embodiments In the above embodiment, a rectangular active area A is used, but the present invention is not limited to this. The active area A may have a polygonal shape other than a rectangular shape in plan view.

[0129] In the above embodiment, the multiple transmitting electrodes 11 and the multiple first wiring portions 25 are arranged on the lower surface 3b of the first substrate 3, and the multiple receiving electrodes 12, the multiple second wiring portions 26, and the monopole antenna 30 are arranged on the upper surface 3a of the first substrate 3. However, this is not limiting. For example, although not shown, the multiple transmitting electrodes 11 and the multiple first wiring portions 25 may be arranged on the upper surface 3a, and the multiple receiving electrodes 12, the multiple second wiring portions 26, and the monopole antenna 30 may be arranged on the lower surface 3b.

[0130] In the above embodiment, the antenna unit 1 is shown in a state in which the cover member 2 and the flexible wiring board 8 are attached to the first substrate 3, but this is not limiting. That is, the concept of the touch sensor 10 includes a state before the cover member 2, the flexible wiring board 8, and the like are attached to the first substrate 3. Furthermore, the concept of the antenna unit 1 (or the touch sensor 10) also includes a configuration in which the above-mentioned plurality of transmitting electrodes 11, the plurality of receiving electrodes 12, the plurality of first wiring portions 25, the plurality of second wiring portions 26, the plurality of pads 27, and the monopole antenna 30 are formed on a long base material (for example, a long hoop-shaped member not shown) in a state before the first substrates 3 are individually formed.

[0131] In the above embodiment, the first connecting portions 45, 45 are provided, but the present invention is not limited to this. For example, if the first conductor 41 is set to the second potential (ground potential in the above embodiment) when the display unit 9 is electrically connected to an IC device (not shown), the first connecting portions 45, 45 do not need to be provided.

[0132] Although the antenna unit 1 according to the above embodiment includes the touch sensor 10 as a component, the present invention is not limited to this. That is, the antenna unit 1 may include, as a main component, a device or component relating to a technical field other than the touch sensor 10, instead of the touch sensor 10 of the above embodiment. Examples of devices or components relating to a technical field other than the touch sensor 10 include a liquid crystal display device, an organic electroluminescence display device (OLED), a micro LED display device, a solar cell device, a heater device, an antenna device, and an electromagnetic wave shielding sheet.

[0133] In the above embodiment, the receiving electrodes 12 are configured with a plurality of conductive wires 20, but this is not limiting. Although not shown, in another embodiment, for example, in an antenna unit 1 including a heater device as a main component, each of the plurality of electrodes provided on the heater device may be configured with a single conductive wire 20. In short, it is sufficient that each electrode applied to the antenna unit 1 is configured with at least one conductive wire 20. Even with such a configuration, the same effects as those described in the above embodiment (i.e., ensuring the antenna characteristics of the monopole antenna 30) can be achieved.

[0134] [Summary] The antenna unit 1 according to the embodiment and the modified example has been described above. The antenna unit 1 according to the present invention has the following configuration.

[0135] The antenna unit 1 includes a first electrode 12a extending along a first direction X and formed of a thin metal wire, a second electrode 12b extending along the first direction X and formed of a thin metal wire, a monopole antenna 30 having first and second radiating portions 32a, 32b located between the first electrode 12a and the second electrode 12b in a planar view, and a plate-shaped conductor 40 located below the monopole antenna 30, overlapping with the radiating portion 31 in a planar view, and spaced apart from the monopole antenna 30. The monopole antenna 30 further includes a first branch electrode portion 33a located to the right of the radiating portion 31 (corresponding to the direction opposite to the Y direction in this specification) and electrically connected to the conductor 40, and a second branch electrode portion 33b located to the left of the radiating portion 31 (corresponding to the Y direction in this specification) and electrically connected to the conductor 40. Here, the first electrode 12a and the second electrode 12b each represent one of a plurality of receiving electrodes 12 in this specification.

[0136] Here, the plate-shaped conductor 40 includes a conductor whose main component is a plate-shaped bottom plate portion 42, such as the first conductor 41. The plate-shaped conductor also includes a conductor whose entire plate is conductive due to a mesh pattern made up of conductive wires. In other words, the plate-shaped conductor 40 includes a second conductor that includes a mesh pattern made up of conductive wires.

[0137] Furthermore, the radiation portion 31 (each of the first and second radiation portions 32a, 32b) has a first potential, and the first branch electrode portion 33a, the second branch electrode portion 33b, and the conductor 40 have a second potential that is lower than the first potential.

[0138] With this configuration, the first electrode 12a and the second electrode 12b (hereinafter referred to as the receiving electrodes 12) located near the first radiating portion 32a do not block the path of the electric field E2 in the third direction Z. Specifically, as shown in FIG. 13 , because each conductive wire 20 constituting the receiving electrode 12 is formed as a thin wire, the electric field E2 travels through areas where the conductive wires 20 are not located (between the conductive wires 20, 20 in this embodiment) and heads toward the first radiating portion 32a (or the first conductor 41) along the normal path of the electric field E2. In other words, the electric field E2 is less affected by the receiving electrode 12. As a result, the electric field E2 is not generally disturbed, and radio waves are normally generated from the monopole antenna 30. Furthermore, the electric field E2 acts to compensate for the partial loss of the electric field E1 described above. This ensures the antenna characteristics of the monopole antenna 30.

[0139] Therefore, in the antenna unit 1 according to the embodiment of the present disclosure, even if the positional relationship between the multiple receiving electrodes 12 and the monopole antenna 30 is optimized, the antenna characteristics of the monopole antenna 30 can be ensured.

[0140] The conductor 40 also has a first conductor 41. The first conductor 41 includes a first opposing surface 44 that faces the monopole antenna 30 in the up-down direction. The first opposing surface 44 overlaps with the monopole antenna 30 in a plan view, and is spaced apart from the monopole antenna 30.

[0141] Furthermore, a first distance D1 between the first opposing surface 44 and the monopole antenna 30 in the up-down direction is not less than 0.5 mm and not more than 5.0 mm.

[0142] By arranging the first opposing surface 44 so as to overlap the monopole antenna 30, the path of the electric field E2 generated between the first radiating portion 32a and the first conductor 41 is more likely to follow the third direction Z. This ensures the antenna characteristics of the monopole antenna 30. Furthermore, by setting the first distance D1, the electric field E2 is more likely to be generated from the monopole antenna 30 in response to radio waves (such as microwaves) used in wireless communication compliant with the Wi-Fi (registered trademark) standard. In other words, the first distance D1 makes it possible to obtain antenna characteristics suited to the type of radio waves in question.

[0143] In addition, a first connection portion 45 is further provided between the first branch electrode portion 33 a and the first conductor 41 , and the first connection portion 45 electrically connects the first branch electrode portion 33 a and the first conductor 41 .

[0144] The first connection portion 45 can improve the reliability of the electrical connection between each of the branch electrode portions 33 a, 33 b and the first conductor 41. As a result, the antenna characteristics of the monopole antenna 30 can be ensured.

[0145] The monopole antenna 30 further includes a short-circuit portion 36 that electrically connects the radiation portion 31 and the first branch electrode portion 33a.

[0146] The short section 36 allows adjustment of impedance matching in the monopole antenna 30 .

[0147] The antenna unit 1 further includes a first substrate 3 having an upper surface. The first electrode 12a, the second electrode 12b, and the monopole antenna 30 are disposed on the upper surface of the first substrate 3.

[0148] With this configuration, the layer for forming the first electrode 12 a and the second electrode 12 b and the layer for forming the monopole antenna 30 can be provided on the same layer, which means that the number of laminated substrates constituting the antenna unit 1 can be reduced.

[0149] The antenna unit 1 further includes a first substrate 3 and a second substrate 50. The second substrate 50 is stacked above the first substrate 3, the first electrode 12a and the second electrode 12b are disposed on the first substrate 3, and the monopole antenna 30 is disposed on the second substrate 50.

[0150] With this configuration, the first electrode 12a and the second electrode 12b (hereinafter referred to as the receiving electrodes 12) located near the first radiating portion 32a do not block the path of the electric field E2 in the third direction Z. Specifically, as shown in FIG. 13 , because each conductive wire 20 constituting the receiving electrode 12 is formed as a thin wire, the electric field E2 travels through areas where the conductive wires 20 are not located (between the conductive wires 20, 20 in this embodiment) and heads toward the first radiating portion 32a (or the first conductor 41) along the normal path of the electric field E2. In other words, the electric field E2 is less affected by the receiving electrode 12. As a result, the electric field E2 is not generally disturbed, and radio waves are normally generated from the monopole antenna 30. Furthermore, the electric field E2 acts to compensate for the partial loss of the electric field E1 described above. This ensures the antenna characteristics of the monopole antenna 30.

[0151] Therefore, in the antenna unit 1 according to the embodiment of the present disclosure, even if the positional relationship between the multiple receiving electrodes 12 and the monopole antenna 30 is optimized, the antenna characteristics of the monopole antenna 30 can be ensured.

[0152] Furthermore, in this configuration, the second substrate 50 on which the monopole antenna 30 is previously arranged can be laminated with a plurality of receiving electrodes 12 on the first substrate 3 using the adhesive layer 7. In other words, this configuration can simplify the manufacturing process of the antenna unit 1.

[0153] The conductor 40 further includes a second conductor 61. The second conductor 61 includes a second opposing surface 63 that faces the monopole antenna 30 in the up-down direction. The second conductor 61 overlaps with the monopole antenna 30 in a plan view and is spaced apart from the monopole antenna 30, and a second distance D2 between the second conductor 61 and the monopole antenna 30 in the up-down direction is smaller than the first distance D1.

[0154] The second distance D2 is 1 / 20 of the first distance D1.

[0155] The second conductor 61 also includes a mesh pattern made up of conductive wires.

[0156] The second distance D2 makes it easier for an electric field to be generated from the radiation portion 31 of the monopole antenna 30 in response to radio waves having a wavelength equal to or less than 1 / 10 of that of microwaves (radio waves in the millimeter wave band, terahertz band, etc.). That is, by providing the second conductor 61 and the second distance D2, it is possible to obtain antenna characteristics different from those suited to the first conductor 41 and the first distance D1.

[0157] The conductor 40 also has a second conductor 61 including a mesh pattern made up of conductive wires. The second conductor 61 includes a second opposing surface 63 that faces the monopole antenna 30 in the up-down direction. The second conductor 61 overlaps with the monopole antenna 30 in a plan view and is spaced apart from the monopole antenna 30, and a second distance D2 in the up-down direction between the second conductor 61 and the monopole antenna 30 is 0.2 mm or more and 0.3 mm or less. In this case, the conductor 40 does not need to have the first conductor 41.

[0158] The electrode 33 further includes a second connection portion 62 between the first branch electrode portion 33 a and the second conductor 61. The second connection portion 62 electrically connects the first branch electrode portion 33 a and the second conductor 61, and the second connection portion 62 electrically connects the second branch electrode portion 33 b and the second conductor 61.

[0159] The second connection portion 62 makes it easy to set the second conductor 61 to a second potential that is lower than the first potential of the radiation portion 31 .

[0160] The first branch electrode portion 70a includes a first bent portion 71a having a first power supply portion 73a and extending in the first direction X, and a first main portion 72a formed integrally with the first bent portion 71a. The first power supply portion 73a of the first bent portion 71a is located at one end of the first bent portion 71a. The first main portion 72a extends from the other end of the first bent portion 71a in a direction intersecting the first direction X. The second branch electrode portion 70b includes a second bent portion 71b having a second power supply portion 73b and extending in the first direction X, and a second main portion 72b formed integrally with the second bent portion 71b. The second power supply portion 73b of the second bent portion 71b is located at one end of the second bent portion 71b, and the second main portion 72b extends from the other end of the second bent portion 71b in a direction intersecting the first direction X.

[0161] This configuration can shorten the overall length of the monopole antenna 30 in the second direction Y. Therefore, in the antenna unit 1, it is easy to arrange multiple (three in the illustrated example) monopole antennas 30 side by side along the second direction Y in the inactive area B. This can further improve the antenna function (e.g., reception sensitivity) of the antenna unit 1.

[0162] The antenna unit 1 also includes a first electrode 12a extending along a first direction X and formed of a thin metal wire, a second electrode 12b extending along the first direction X and formed of a thin metal wire, and a monopole antenna 30. The monopole antenna 30 has a first radiating portion 32a and a second radiating portion 32b located between the first electrode 12a and the second electrode 12b in a planar view, a first branch electrode portion 33a located on the first electrode 12a side as seen from the first radiating portion 32a and extending in a direction different from the first direction X, and a second branch electrode portion 33b located on the second electrode 12b side as seen from the first radiating portion 32a and extending in a direction different from the first direction X, and the second radiating portion 32b is electrically connected to the first branch electrode portion 33a.

[0163] With this configuration, only the first radiating portion 32a can be disposed between the first electrode 12a and the second electrode 12b, rather than both the first radiating portion 32a and the second radiating portion 32b. This allows the distance between the first radiating portion 32a and the first electrode 12a or the distance between the first radiating portion 32a and the second electrode 12b to be increased. This improves the radiation efficiency of the first radiating portion 32a. Furthermore, the width of the first radiating portion 32a can be increased. This reduces the resistance value of the first radiating portion 32a, further improving the radiation efficiency of the first radiating portion 32a.

[0164] Furthermore, compared to when the first radiating portion 32 a and the second radiating portion 32 b are disposed between the first electrode 12 a and the second electrode 12 b, the distance between the first electrode 12 a and the second electrode 12 b can be narrowed, thereby improving the sensing efficiency of the touch sensor 10.

[0165] The antenna unit 1 also includes a third electrode 12c formed of a thin metal wire, extending along the first direction X and positioned on the opposite side of the first electrode 12a from the second electrode 12b, and the second radiating portion 32b is positioned between the first electrode 12a and the third electrode 12c in a plan view. This ensures the antenna function of the second radiating portion 32b. Furthermore, the first electrode 12a or the third electrode 12c can be installed at the edge of the viewing area. This allows the sensing area of ​​the touch sensor 10 to be widened.

[0166] The second radiating portion 32b is shorter than the first radiating portion 32a, which enables the monopole antenna 30 to communicate in multiple frequency bands.

[0167] The antenna unit 1 further includes a fourth electrode 12d formed of a thin metal wire, extending along the first direction X and positioned on the opposite side of the first electrode 12a from the third electrode 12c, and the monopole antenna 30 further includes a third radiating portion 32c positioned between the third electrode 12c and the fourth electrode 12d in a planar view, and the third radiating portion 32c is electrically connected to the first branch electrode portion 33a.

[0168] The third radiating portion 32c is shorter than the second radiating portion 32b, which enables the monopole antenna 30 to communicate in multiple frequency bands.

[0169] The present disclosure is industrially applicable as an antenna unit.

[0170] 1: Antenna unit 2: Cover member 3: First substrate 9: Display section 10: Touch sensor 11: Transmitting electrode 12: Receiving electrode 12a: First electrode 12b: Second electrode 12c: Third electrode 12d: Fourth electrode 12e: Fifth electrode 13: Mesh pattern 14: Cell 20: Conductive wire 25: First wiring section 26: Second wiring section 30: Monopole antenna 31: Radiating section 32a: First radiation section 32b: Second radiation section 32c: Third radiation section 33a: First branched electrode section 33b: Second branched electrode section 36: Short section 40: Conductor 41: First conductor 42: Bottom plate section 43: Wall section 44: First opposing surface 45: First connecting section 50: Second substrate 60: Third substrate 61: Second conductor 62: Second connecting section 63: Second opposing surface 70a: First branch electrode portion 70b: Second branch electrode portion 71a: First bent portion 71b: Second bent portion 72a: First main body portion 72b: Second main body portion 73a: First power supply portion 73b: Second power supply portion A: Active area B: Inactive area D1: First interval D2: Second interval X: First direction Y: Second direction Z: Third direction

Claims

1. An antenna unit comprising: a first electrode extending in a first direction and formed of a thin metal wire; a second electrode extending in the first direction and formed of a thin metal wire; a monopole antenna having a radiating portion located between the first electrode and the second electrode in a planar view; and a plate-shaped conductor located below the monopole antenna, overlapping with the radiating portion in a planar view, and spaced apart from the monopole antenna, wherein the monopole antenna further comprises: a first branch electrode portion located to the right of the radiating portion and electrically connected to the conductor; and a second branch electrode portion located to the left of the radiating portion and electrically connected to the conductor.

2. An antenna unit according to claim 1, wherein the radiation portion has the first potential, and the first branch electrode portion, the second branch electrode portion and the conductor have a second potential lower than the first potential.

3. An antenna unit as described in claim 1, wherein the conductor has a first conductor, the first conductor includes a first opposing surface that faces the monopole antenna in the vertical direction, and the first opposing surface overlaps with the monopole antenna in a plan view and is spaced apart from the monopole antenna.

4. An antenna unit according to claim 3, wherein a first gap in the vertical direction between said first opposing surface and said monopole antenna is 0.5 mm or more and 5.0 mm or less.

5. An antenna unit according to claim 1, further comprising a first connection portion between the first branch electrode portion and the first conductor, the first connection portion electrically connecting the first branch electrode portion and the first conductor.

6. An antenna unit according to claim 5, wherein the monopole antenna further has a short-circuit portion that electrically connects the radiation portion and the first branch electrode portion.

7. An antenna unit according to claim 1, further comprising a first substrate having an upper surface, and the first electrode, the second electrode and the monopole antenna are disposed on the upper surface of the first substrate.

8. An antenna unit according to claim 1, further comprising a first substrate and a second substrate, the second substrate being stacked above the first substrate, the first electrode and the second electrode being disposed on the first substrate, and the monopole antenna being disposed on the second substrate.

9. An antenna unit as described in claim 3, wherein the conductor further has a second conductor, the second conductor includes a second opposing surface that faces the monopole antenna in the vertical direction, the second conductor overlaps with the monopole antenna in a plan view and is spaced apart from the monopole antenna, and a second gap in the vertical direction between the second conductor and the monopole antenna is smaller than the first gap.

10. An antenna unit according to claim 9, wherein the length of said second interval is 1 / 20 of the length of said first interval.

11. An antenna unit according to claims 9 and 10, wherein the second conductor includes a mesh pattern made up of conductive lines.

12. An antenna unit as described in claim 1, wherein the conductor has a second conductor including a mesh pattern made up of conductive wires, the second conductor includes a second opposing surface that faces the monopole antenna in the vertical direction, the second conductor overlaps with the monopole antenna in a planar view and is spaced apart from the monopole antenna, and a second gap in the vertical direction between the second conductor and the monopole antenna is 0.2 mm or more and 0.3 mm or less.

13. An antenna unit according to any one of claims 9 to 12, further comprising a second connection portion between the first branch electrode portion and the second conductor, the second connection portion electrically connecting the first branch electrode portion and the second conductor, and the second connection portion electrically connecting the second branch electrode portion and the second conductor.

14. An antenna unit as claimed in any one of claims 1 to 13, wherein the first branch electrode portion includes a first bent portion having a first power supply portion and extending in the first direction, and a first main body portion formed integrally with the first bent portion, the first power supply portion of the first bent portion being located at one end of the first bent portion, and the first main body portion extending from the other end of the first bent portion in a direction intersecting the first direction, the two-branch electrode portion includes a second bent portion having a second power supply portion and extending in the first direction, and a second main body portion formed integrally with the second bent portion, the second power supply portion of the second bent portion being located at one end of the second bent portion, and the second main body portion extending from the other end of the second bent portion in a direction intersecting the first direction.

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