Radio communication device

Abstract

To provide a cover for a display of a radio terminal capable of amplifying radio waves of an antenna that makes a direction with the display arranged a main radiation direction by suppressing a deterioration in antenna performance of the radio terminal arranged even on the display.SOLUTION: This cover for a display of a radio terminal is a cover for a display of a radio terminal arranged on the display of a radio terminal formed in the shape of a plate includes a sheet-like transparent member arranged so as to overlap on the display and formed with a transparent dielectric body with a relative dielectric constant being within the range from 1 to 10, and a plurality of conductive elements arranged on the transparent member side by side with visible light transmittance being 50% or more. The conductive elements are formed such that the length of the longest line segment longest among line segments formed on the conductive elements by connecting two optional points on the conductive elements is within the range from 0.1 times to 0.4 times of the length of effective wavelength in the dielectric body of radio waves used for radio communication by the radio terminal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cover for a display of a wireless terminal. [Background technology]

[0002] In recent years, wireless terminals such as smartphones have become widely used. Various techniques have been proposed to improve the antenna performance of such wireless terminals.

[0003] For example, Patent Document 1 describes an antenna device in which a thin metal film provided on the interior side of a window is concentrically removed to form circular zones, and radio waves diffracted by passing through the zones converge at a position where the phases are aligned, thereby increasing the energy density. Patent Document 2 describes an antenna device in which each parasitic element is fixed to a dielectric substrate so that it is positioned in the radiation direction as seen from the feed element. Patent Document 3 describes an antenna for a wireless device that includes a second radiator installed on the cover of the wireless device to radiate a wireless signal radiated by a first radiator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-171122 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-079340 [Patent Document 3] Japanese Patent Application Publication No. 2017-537515 Summary of the Invention [Problem to be solved by the invention]

[0005] Display covers are often used in wireless terminals such as smartphones to protect the display and prevent others from peeking at it. Recent wireless terminals sometimes use antenna modules whose main radiation direction is directed toward the display, and the placement of a display cover may degrade the antenna performance of such wireless terminals.

[0006] One aspect of the disclosed technology aims to provide a cover for a display of a wireless terminal that suppresses degradation of the antenna performance of the wireless terminal even when placed on a display, and that can amplify the radio waves of an antenna whose main radiation direction is in the direction in which the display is placed. [Means for solving the problem]

[0007] One aspect of the disclosed technology is exemplified by the following wireless terminal display cover. This wireless terminal display cover is a wireless terminal display cover that is placed on a wireless terminal display that is formed in a plate shape. This wireless terminal display cover includes: a sheet-like transparent member that is arranged to overlap the display and is formed of a transparent dielectric material with a relative dielectric constant in the range of 1 to 10; and a plurality of conductor elements that are arranged side by side on the transparent member and have a visible light transmittance of 50% or more. The conductor elements are formed so that the length of the longest line segment that connects any two points on the conductor elements and is formed on the conductor elements is within the range of 0.1 to 0.4 times the effective wavelength within the dielectric of the radio waves used for wireless communication by the wireless terminal. [Effects of the Invention]

[0008] This wireless terminal display cover can suppress a decrease in the wireless terminal's antenna performance even when placed on the display, and can amplify the radio waves of the antenna whose main radiation direction is in the direction in which the display is placed. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is a diagram showing an example of a display cover for a smartphone according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of a state in which a smartphone provided with a display cover according to an embodiment is viewed from the front side. [Figure 3] FIG. 3 is a diagram schematically illustrating the positional relationship between the conductive element provided on the display cover according to the embodiment and the antenna of the display cover. [Figure 4] FIG. 4 is a first diagram illustrating the parameters used in the first simulation. [Figure 5] FIG. 5 is a second diagram illustrating the parameters used in the first simulation. [Figure 6] FIG. 6 is a diagram illustrating the results of the second simulation. [Figure 7] FIG. 7 is a diagram showing an example of a display cover according to a first modified example. [Figure 8] FIG. 8 is a first diagram showing variations in the positional relationship between the conductive element and the patch antenna in the first modified example. [Figure 9] FIG. 9 is a second diagram showing variations in the positional relationship between the conductive element and the patch antenna in the first modified example. [Figure 10] FIG. 10 is a third diagram showing variations in the positional relationship between the conductive element and the patch antenna in the first modified example. [Figure 11] FIG. 11 is a fourth diagram showing variations in the positional relationship between the conductive element and the patch antenna in the first modified example. [Figure 12] FIG. 12 is a first diagram illustrating an example of an arrangement of conductive elements that adopt a shape other than a rectangle. [Figure 13] FIG. 13 is a second diagram illustrating an arrangement of conductive elements that adopt a shape other than a rectangle. [Figure 14] FIG. 14 is a third diagram illustrating an arrangement of conductive elements that adopt a shape other than a rectangle. [Figure 15]FIG. 15 is a fourth diagram illustrating an arrangement of conductive elements having a shape other than a rectangle. [Figure 16] FIG. 16 is a diagram illustrating an example of an arrangement pattern of conductive elements. [Figure 17] FIG. 17 is a diagram showing an example of a display cover having a protrusion. [Figure 18] FIG. 18 is a diagram illustrating a state in which a display cover with a protrusion is attached to a smartphone. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Embodiment> The configurations of the embodiments described below are merely examples, and the disclosed technology is not limited to the configurations of the embodiments. A display cover for a wireless terminal according to the embodiments has, for example, the following configuration. The display cover for a wireless terminal according to the present embodiment is a wireless terminal display cover that is placed on a plate-shaped display of the wireless terminal. The display cover for the wireless terminal includes: a sheet-like transparent member that is arranged to overlap the display and is made of a transparent dielectric material with a relative permittivity ranging from 1 to 10; and a plurality of conductor elements that are arranged side by side on the transparent member and have a visible light transmittance of 50% or more. The conductor elements are formed so that the length of the longest line segment that connects any two points on the conductor element and is formed on the conductor element is within a range of 0.1 to 0.4 times the effective wavelength in the dielectric of the radio waves used for wireless communication by the wireless terminal.

[0011] According to such a cover for a display of a wireless terminal, the conductive element can be made to function as a resonator for the antenna of the wireless terminal, the main radiation direction of which is directed toward the display. In addition, since the wireless terminal cover has multiple conductive elements arranged side by side, it is possible to maximize the possibility of placing the conductive elements near the antenna. In other words, the wireless terminal display cover increases the possibility of the conductive elements operating as a resonator, and by operating the conductive elements as a resonator, it is possible to improve the operating gain of the wireless terminal antenna. Furthermore, the conductive elements of the wireless terminal display cover have a visible light transmittance of 50% or more. Therefore, even when the wireless terminal display cover is placed on a display, it is possible to reduce the user's discomfort with the display.

[0012] Hereinafter, an embodiment in which the above-described wireless terminal display cover is applied to a smartphone display cover will be further described with reference to the drawings. FIG. 1 is a diagram showing an example of a smartphone display cover 100 according to the embodiment. The display cover 100 is a member that is placed on a smartphone display and protects the display. The display cover 100 includes a sheet portion 101 formed in a sheet (plate) shape and four conductive elements 120 arranged on the sheet portion 101. Note that, although the sheet portion 101 is formed in a rectangular shape in FIG. 1, the shape of the sheet portion 101 may be determined appropriately depending on the shape of the smartphone display to be protected. Also, although four conductive elements 120 are arranged in FIG. 1, the number of conductive elements 120 is not limited to four.

[0013] The sheet member 101 is a transparent sheet-like member. Here, "transparent" means, for example, that the transmittance of visible light is 50% or more. The sheet member 101 is formed of a dielectric material having, for example, a relative dielectric constant of about 1 to 10 and a thickness of about 0.1 to 0.5 mm. Examples of such dielectric materials include polyethylene terephthalate (PET), thermoplastic polyurethane (TPU), and optical glass.

[0014] The sheet part 101 is a member that is placed on the display of the smartphone to be protected by the display cover 100 so as to cover the display. The sheet part 101 is formed in a substantially rectangular plate shape that matches the shape of the display of the smartphone to be protected by the display cover 100. The sheet part 101 protects the display by, for example, being placed so as to overlap the display of the smartphone.

[0015] The conductive element 120 is a transparent element formed by processing a conductor such as a metal into a thin plate. The conductive element 120 can also be referred to as a thin film formed of a metal. Examples of metals that form the conductive element 120 include gold (Au), silver (Ag), copper (Cu), indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), and zinc oxide (AZO). The conductive element 120 can be made transparent by processing such a metal into a thin film having a thickness of 30 nm or less or into a mesh shape, for example.

[0016] The conductive element 120 is disposed at a position corresponding to an antenna module with its main radiation direction facing the display side, which is provided in the smartphone to be protected by the display cover 100. The size of the conductive element 120 is determined according to the wavelength of the radio waves used for wireless communication by the smartphone housed in the smartphone cover 100 and the dielectric constant of the dielectric forming the sheet part 101 of the display cover 100. The conductive element 120 is, for example, formed to have an effective wavelength λ of the smartphone's radio waves, taking into account wavelength shortening due to the dielectric forming the sheet part 101 and the glass and housing of the smartphone. g Then, the length of the diagonal is 0.1λ g to 0.4λ g A plate-like polygon with a diameter of 0.1λ g to 0.4λ g The pitch between adjacent conductive elements 120 is 0.5λ g It is preferable to set the following.

[0017] For example, if a smartphone that is the object of protection of the display cover 100 is in the millimeter wave band (circumferential When wireless communication is performed using radio waves with a frequency of 24 to 300 GHz, the effective wavelength λ in the sheet portion 101 is selected from materials with a relative dielectric constant in the range of 1 to 10. g can be determined by the following equation (1):

number

[0018] In the above equation (1), c is the speed of light, f is the frequency, ε r is the relative permittivity. From equation (1), the effective wavelength λ g is 0.32 mm or more and 12.5 mm or less. Therefore, when a smartphone performs wireless communication using radio waves in the millimeter wave band, the conductive element 120 can be a plate-like polygon with a diagonal length of 0.032 to 5 mm, or a disk with a diameter of 0.032 to 5 mm. Furthermore, the pitch between adjacent conductive elements 120 is preferably within the range of 0.16 to 6.25 mm. The diagonal length (or diameter) and pitch of the conductive element 120 determined as described above are intended to cause the conductive element 120 to operate as a resonator, not as an antenna radiator.

[0019] 2 is a diagram showing an example of a smartphone 500 provided with a display cover 100 according to an embodiment, as viewed from the front side. The smartphone 500 is formed in the shape of a rectangular plate when viewed overall. A display 513 is provided on the front side of the smartphone 500. The smartphone 500 can be said to be a smartphone in which the display cover 100 is placed on the display 513.

[0020] 2, the positions of antennas mounted on the smartphone 500 are indicated by dotted lines. The smartphone 500 includes five millimeter-wave antenna modules 501, 502, 503, 504, and 505. The millimeter-wave antenna modules 501, 502, 503, 504, and 505 are antennas that perform wireless communication using radio waves in the millimeter wave band.

[0021] Each of millimeter-wave antenna modules 501, 502, 503, 504, and 505 is a four-element patch array antenna having four patch antennas 530. Millimeter-wave antenna modules 501 and 503 are provided on side surface 512 forming the short side of smartphone 500 so that the direction of transmission and reception of radio waves faces. Millimeter-wave antenna module 502 is provided on side surface 511 forming the long side of smartphone 500 so that the direction of transmission and reception of radio waves faces. Millimeter-wave antenna module 504 is provided on the bottom surface of smartphone 500 so that the direction of transmission and reception of radio waves faces. Millimeter-wave antenna module 505 is provided on display 513 of smartphone 500 so that the direction of transmission and reception of radio waves faces.

[0022] In the display cover 100, a conductive element 120 is disposed on a sheet portion 101 that is physically separated from the millimeter-wave antenna modules 501, 502, 503, 504, and 505 to which the power feed lines of the smartphone 500 are connected. In the display cover 100, the conductive element 120 operates as a resonator for radio waves emitted from the millimeter-wave antenna modules 501, 502, 503, 504, and 505. The conductive element 120 operates without receiving power from a physical connection from the smartphone 500, and therefore can also be called a parasitic element.

[0023] 3A and 3B are diagrams showing a schematic diagram of the positional relationship between the conductive element provided on the display cover 100 according to the embodiment and the antenna of the display cover 100. FIG. 3A is a diagram showing the millimeter-wave antenna module 505 and the conductive element 120 as viewed from the side, and FIG. 3B is a diagram showing the millimeter-wave antenna module 505 and the conductive element 120 as viewed from the front. In FIG. 3B, the millimeter-wave antenna module 505 and the conductive element 120, which cannot be seen when viewed from the front, are shown. A patch antenna 530 provided on the roof 505 is illustrated by a dotted line.

[0024] The display cover 100 and the display 513 of the smartphone 500 are detachably attached, for example, by double-sided tape 110 provided on the back surface of the sheet portion 101. On the sheet portion 101 of the display cover 100, a plurality of conductive elements 120 are arranged side by side at positions corresponding to the patch antennas 530 of the millimeter-wave antenna module 505, whose main radiation direction faces the display 513 side of the smartphone 500. Therefore, when the display cover 100 is placed on the display 513 of the smartphone 500, each of the conductive elements 120 is positioned in the direction in which radio waves are emitted by each of the patch antennas 530 provided on the millimeter-wave antenna module 505. In FIG. 3 , the conductive elements 120 and the patch antennas 530 are arranged overlapping each other so that their centers coincide when viewed from the front, but the centers of the conductive elements 120 and the patch antennas 530 may be offset from each other when viewed from the front.

[0025] The patch antenna 530 has an effective wavelength λ g 3, the conductive element 120 located near the emission direction of the radio waves from the patch antenna 530 operates as a resonator (a so-called stacked patch). By having the conductive element 120 operate as a stacked patch, the display cover 100 can improve the operating gain of the millimeter-wave antenna module 505 of the smartphone 500.

[0026] <Simulation> The effects of the display cover 100 were verified by performing a simulation, and will be described below.

[0027] (First simulation) In the first simulation, the thickness of the sheet portion 101 and the length of the diagonal line of the conductive element 120 were varied as parameters to verify the effect of the display cover 100.

[0028] 4 and 5 are diagrams illustrating the parameters used in the first simulation. Fig. 4 illustrates the thickness t1 of the sheet portion 101, the thickness t2 of the double-sided tape 110, the thickness t3 of the display 513, the distance t4 between the display 513 and the millimeter-wave antenna module 505, and the thickness t4 of the substrate of the millimeter-wave antenna module 505. Fig. 5 illustrates the length S of the diagonal line (longest line segment) of the conductor element 120.

[0029] In the first simulation, the thickness t2 of the double-sided tape 110 is set to 0.05 mm, the thickness t3 of the display 513 is set to 0.7 mm, the gap t4 between the display 513 and the millimeter-wave antenna module 505 is set to 0.23 mm, and the thickness t4 of the substrate of the millimeter-wave antenna module 505 is set to 0.27 mm. The relative dielectric constant of the sheet portion 101 is set to 6.8, the relative dielectric constant of the double-sided tape 110 to 3.0, the relative dielectric constant of the display 513 to 6.8, and the relative dielectric constant of the substrate of the millimeter-wave antenna module 505 to 12.0. In the first simulation, the thickness t1 of the sheet portion 101 is varied within a range from 0.1 mm to 1.0 mm, and the length of the longest line segment S of the conductive element 120 is varied within a range from 0.28 mm to 5.0 mm.

[0030] The results of the first simulation are shown in Table 1 below. Table 1 below illustrates the gain (dBi) of the patch antenna 530 when the thickness t1 of the sheet portion 101 and the length of the longest line segment S of the conductor element 120 are varied. Table 1 below also illustrates the case where the conductor element 120 is not provided (the value of S in Table 1 corresponds to 0 mm). Note that when the display cover 100 is not provided on the display 513 (when the sheet portion 101 and the conductor element 120 are not present), the gain of the patch antenna 530 was 9.54 dBi. [Table 1]

[0031] Conventionally, protective covers for displays have a thickness of 0.15 mm to 0.33 mm, with thicknesses of around 0.2 mm being widely used. Referring to Table 1 above, for example, when t1 is 0.1 mm and S is in the range of 0.56 to 3.78 mm, when t1 is 0.2 mm and S is in the range of 0.56 to 3.43 mm, and when t1 is 0.3 mm and S is in the range of 1.33 to 3.43 mm, the gain of patch antenna 530 is improved compared to when display cover 100 is not provided on display 513 or when only sheet portion 101 is provided on display 513. Table 1 also shows that a maximum gain of 10.69 dBi was achieved when t1 was 0.1 mm and S was 3.08 mm.

[0032] (Second simulation) In the second simulation, the gain of the patch antenna 530 was examined when the conductivity and thickness of the conductive element 120 were varied. FIG. 6 is a diagram illustrating the results of the second simulation. The vertical axis of FIG. 6 illustrates the operational gain of the patch antenna 530, and the horizontal axis illustrates the conductivity of the conductive element 120. In the second simulation, the thickness of the conductive element 120 was set to 400 nm, 40 nm, 4 nm, 2.2 nm, 0.4 nm, and 1.0 nm, and the gain of the patch antenna 530 was examined. In FIG. 6, the operational gain of the patch antenna 530 without the conductive element 120 is illustrated by a straight line L.

[0033] Referring to FIG. 6, it can be seen that the operational gain of the patch antenna 530 is improved when the conductive element 120 is provided compared to when the conductive element 120 is not provided. Here, it can be seen that if the conductivity of the conductive element 120 is less than 5.8e+3 S / m, the effect of amplifying the gain of the patch antenna 530 drops sharply. Therefore, it can be said that the conductivity of the conductive element 120 is preferably 5.8e+3 S / m or more. Also, referring to FIG. 6, it can be seen that if the thickness of the conductive element 120 is too thin, the effect of amplifying the patch antenna 530 drops. Therefore, it is preferable that the thickness of the conductive element 120 is 1 nm or more.

[0034] <Effects of the embodiment> Placing a display cover on the display 513 of the smartphone 500 may reduce the operating gain of the display 513 when the direction of radio wave emission is directed toward the display 513. This problem occurs particularly in smartphones that are compatible with 5G and utilize radio waves in the millimeter wave band.

[0035] In this embodiment, a conductive element 120 is placed on the display cover 100, and the conductive element 120 is operated as a stacked patch, which is a parasitic element, so that even if the display cover is placed on the display 513 of the smartphone 500, a decrease in the operating gain of the smartphone 500 can be suppressed.

[0036] In this embodiment, the shape of the conductor element 120 is optimized for millimeter-wave radio waves. That is, one side of the rectangular conductor element 120 is 0.1λ g to 0.4λ g By setting the distance (0.032 to 5 mm), the conductive element 120 can function as a resonator suitable for millimeter-wave radio waves. As a result, according to this embodiment, an improvement in the operating gain of the smartphone 500 in which the display cover 100 is placed on the display 513 can be expected.

[0037] Furthermore, in this embodiment, the conductive element 120 is arranged in a position on the sheet part 101 corresponding to the millimeter-wave antenna module 505 of the smartphone 500. By arranging the conductive element 120 in this manner, the conductive element 120 is more likely to be arranged in a position that is favorable for amplifying the operating gain of the patch antenna 530 provided on the millimeter-wave antenna module 505.

[0038] <First Modification> FIG. 7 is a diagram showing an example of a display cover 100a according to a first modified example. In the embodiment, the pitch interval of the conductor elements 120 is 0.5 λg (0.16 to 6.25 mm), but the pitch interval of the conductor elements 120 is not limited to being equal. As illustrated in FIG. 7, the conductor elements 120 may be unevenly arranged within the above interval (0.16 to 6.25 mm). Among the unevenly arranged conductor elements 120, a set of conductor elements 120 arranged at a first pitch interval is an example of a "set of conductor elements arranged at a first pitch interval." Among the unevenly arranged conductor elements 120, a set of conductor elements 120 arranged at a second pitch interval is an example of a "set of conductor elements arranged at a second pitch interval." It is preferable that both the first pitch interval and the second pitch interval be selected within the range of 0.5 λg (0.16 to 6.25 mm).

[0039] 8 to 11 are diagrams illustrating variations in the positional relationship between the conductive element 120 and the patch antenna 530 in the first modified example. FIGS. 8 to 11 are front views of the conductive element 120 and its vicinity when the display cover 100a is placed on the display 513. Note that the number of conductive elements 120 placed on the sheet portion 101 is also varied in FIGS. 8 to 11. In the display cover 100a, multiple conductive elements 120 are placed in positions where there is a high probability that the millimeter-wave antenna module 505 will be present. Therefore, there is a high probability that one of the multiple placed conductive elements 120 will be placed in front of or near the patch antenna 530 provided on the millimeter-wave antenna module 505. Therefore, even with the first modified example, an improvement in the operating gain of the display cover 100a can be expected. Furthermore, the number of conductive elements 120 and the number of patch antennas 530 may be the same or different.

[0040] In the embodiment and the first modification, the distance between the plurality of conductor elements 120 arranged side by side is optimized for millimeter wave band radio waves. g By setting the distance (0.16 to 6.25 mm), even if there is a positional misalignment between the conductive element 120 and the patch antenna 530 provided in the millimeter-wave antenna module 505 of the smartphone 500, the conductive element 120 can operate as a resonator suitable for millimeter-wave radio waves.

[0041] <Other variations> In the embodiment, the shape of the conductor element 120 is rectangular, but the shape of the conductor element 120 is not limited to a rectangle. The conductor element 120 may be circular or a polygon other than a rectangle. Figs. 12 to 15 are diagrams illustrating the arrangement of conductor elements 120 employing a shape other than a rectangle. Also, in Figs. 12 to 15, the conductor elements 120 are arranged not in a single row but in multiple rows. Fig. 12 illustrates an example of a conductor element 120 formed in an elliptical shape. When the conductor element 120 is elliptical, the major axis of the conductor element 120 is 0.1λ. g to 0.4λ g(0.032 to 5 mm). In addition, when the conductive element 120 is a perfect circle, the diameter of the conductive element 120 is 0.1λ. g to 0.4 λ g (0.032 to 5 mm) should be used.

[0042] 13 illustrates a pentagonal conductive element 120, and FIG. 14 illustrates a rectangular conductive element 120. When the conductive element 120 is a polygon including a rectangle, the longest line segment of one side or diagonal line is 0.1λ. g to 0.4λ g (0.032 to 5 mm). That is, the conductor element 120 is formed in a plate shape, and its shape when viewed from the front can be formed in various ways. The conductor element 120 formed in various shapes has a length of 0.1λ or less of the longest line segment (also referred to as the maximum line segment) among the line segments formed on the conductor element 120 by connecting any two points on the conductor element 120. g to 0.4λ g (0.032 to 5 mm) should be used.

[0043] Fig. 15 is a diagram illustrating an example of an arrangement of conductor elements of various shapes. As illustrated in Fig. 15, the display cover 100 may be provided with a mixture of circular or elliptical conductor elements 120 and polygonal conductor elements 120. That is, the display cover 100 may be provided with conductor elements 120 of a plurality of different shapes. Furthermore, the display cover 100 may have the conductor elements 120 aligned in a plurality of rows.

[0044] FIG. 16 is a diagram illustrating an arrangement pattern of the conductive elements 120. The double-sided tape 110 is not shown in FIG. 16. FIG. 16(A) illustrates a state in which the conductive elements 120 are arranged on the outer surface of the sheet portion 101 (the surface opposite the display 513). FIG. 16(B) illustrates a state in which the outer surface of the sheet portion 101 is etched and the conductive elements 120 are arranged in the etched portion. FIG. 16(C) illustrates a state in which the inner surface of the sheet portion 101 (the surface on the display 513 side) is etched and the conductive elements 120 are arranged in the etched portion. FIG. 16(D) illustrates a state in which three conductive elements 120 are arranged side by side in the thickness direction of the sheet portion 101.

[0045] As illustrated in Figures 16(A) to 16(C), the conductive elements 120 may be provided on the surface of the sheet portion 101, or the surface of the sheet portion 101 may be etched (shaved) and the conductive elements 120 may be embedded therein. The thickness direction of the sheet portion 101 in the display cover 100 substantially coincides with the direction in which the patch antenna 530 of the millimeter-wave antenna module 503 emits radio waves. Therefore, as illustrated in Figure 16(D), the conductive elements 120 are arranged side by side in the thickness direction of the sheet portion 101, thereby further improving the operating gain of the patch antenna 530. Note that, although three conductive elements 120 are arranged side by side in the thickness direction of the sheet portion 101 in Figure 16(D), two conductive elements 120 may be arranged side by side, or four or more conductive elements 120 may be arranged side by side.

[0046] The display cover 100 may further include a protrusion disposed on a side surface of the smartphone 500. FIG. 17 is a diagram showing an example of a display cover 100b including a protrusion 130. The protrusion 130 is formed to protrude from the long side of the sheet portion 101 in the direction of the short side of the sheet portion 101. A conductive element 120 is disposed on the protrusion 130 at a position corresponding to a patch antenna 530 of a millimeter-wave antenna module 502 provided on a side surface 511 of the smartphone 500 so as to face the direction of transmission and reception of radio waves. When the display cover 100b is attached to the smartphone 500, the protrusion 130 is folded along a folding line 131 and disposed on the side surface of the smartphone 500. The conductive element 120 disposed on the protrusion 130 is an example of an "additional conductive element."

[0047] 18 is a diagram illustrating a state in which a display cover 100b having a protrusion 130 is attached to a smartphone 500. In FIG. 18, the display 513 of the smartphone 500 is illustrated facing upward. When the display cover 100 is attached to the smartphone 500, the protrusion 130 is arranged on a side surface 511 of the smartphone 500. Since the conductive element 120 on the protrusion 130 is provided at a position corresponding to the patch antenna 530 of the millimeter-wave antenna module 502, the display cover 100b can improve the operating gain of the patch antenna 530 of the millimeter-wave antenna module 502.

[0048] The embodiments and modifications disclosed above can be combined with each other. [Explanation of symbols]

[0049] 100··Display cover 100a··Display cover 100b··Display cover 101 Seat section 110··Double-sided tape 120 Conductor element 130...Protrusion 131··Bending line 500··Smartphone 501··Millimeter-wave antenna module 502··Millimeter-wave antenna module 503··Millimeter-wave antenna module 504··Millimeter-wave antenna module 505··Millimeter-wave antenna module 530··Patch antenna 511··Side 512··Side 513··Display

Claims

1. A cover for a display of a wireless terminal that is arranged on a display of the wireless terminal formed in a plate shape, a sheet-like transparent member arranged so as to overlap the display and formed of a transparent dielectric material having a relative dielectric constant in the range of 1 to 10; a plurality of conductive elements arranged side by side on the transparent member, the conductive elements having a visible light transmittance of 50% or more; the conductor element is formed so that the length of the longest line segment among the line segments formed on the conductor element by connecting any two points on the conductor element is within a range of 0.1 to 0.4 times the length of the effective wavelength in the dielectric of the radio wave used by the wireless terminal for wireless communication, the plurality of conductive elements further include a plurality of additional conductive elements arranged in a thickness direction of the transparent member; A cover for the display of a wireless terminal.

2. the plurality of conductive elements include conductive elements formed in a polygonal shape in a front view, The longest line segment is the length of one side of the conductor element formed in the polygon, or the longest line segment among the diagonals of the conductor element formed in the polygon. A cover for a display of a wireless terminal according to claim 1.

3. the plurality of conductive elements include a conductive element formed in a circular shape in a front view, The longest line segment is the diameter of the circularly formed conductive element. A cover for a display of a wireless terminal according to claim 1 or 2.

4. The plurality of conductive elements are arranged at equal intervals. A cover for a display of a wireless terminal according to any one of claims 1 to 3.

5. the plurality of conductive elements include a set of conductive elements in which adjacent conductive elements are arranged at a first pitch interval, and a set of conductive elements in which adjacent conductive elements are arranged at a second pitch interval different from the first pitch interval; A cover for a display of a wireless terminal according to any one of claims 1 to 3.

6. Each of the plurality of conductive elements is provided within the dielectric. A cover for a display of a wireless terminal according to any one of claims 1 to 5.

7. The plurality of conductive elements are formed of one or more metals selected from the group consisting of gold (Au), silver (Ag), copper (Cu), indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), and zinc oxide (AZO). A cover for a display of a wireless terminal according to any one of claims 1 to 6.

8. a protrusion is formed on the transparent member and is disposed on a side surface of the wireless terminal; The plurality of conductive elements are disposed on the protrusion. A cover for a display of a wireless terminal according to any one of claims 1 to 7.

9. The plurality of conductive elements have a pitch interval between adjacent conductive elements that is 0.5 times the effective wavelength. A cover for a display of a wireless terminal according to claim 4.

10. the radio waves are millimeter wave band radio waves, The pitch interval is in the range of 0.16 mm to 6.25 mm. The cover for a display of a wireless terminal according to claim 9.

11. the radio waves are millimeter wave band radio waves, The length of the longest line segment is in the range of 0.032 mm to 5 mm. A cover for a display of a wireless terminal according to any one of claims 1 to 10.

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