Cover for the display of a wireless terminal

Abstract

The present invention provides a display cover for a wireless terminal that suppresses a decrease in antenna performance of the wireless terminal even when arranged on a display, and that can amplify electric waves of the antenna that uses the direction in which the display is arranged as the main radiation direction. This display cover for a wireless terminal is arranged on the display of a wireless terminal formed in a plate shape. This display cover for a wireless terminal comprises: a sheet-shaped transparent member arranged so as to be superimposed on the display and formed using a transparent dielectric in which the relative dielectric constant is in the range of 1-10; and a plurality of conductive elements arranged side by side on the transparent member, the visible light transmittance of the conductive elements being 50% or greater. The conductive elements are formed such that the length of the longest line segment, which is the longest among the line segments formed on the conductive element by connecting any two points on the conductive element, is in the range of 0.1-0.04 times the length of the effective wavelength in the dielectric of the electric wave used for wireless communication by the wireless terminal.

Description

Technical Field

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

Background Art

[0002] In recent years, wireless terminals such as smartphones have been widely used. In such wireless terminals, various techniques for improving antenna performance have been proposed.

[0003] For example, Patent Document 1 describes an antenna device in which a circular annular band is formed by removing a metal thin film concentrically in a metal thin film provided on the indoor side of a window, and diffracted radio waves transmitted through the annular band converge at a position where the phases are aligned and the energy density increases. Patent Document 2 describes an antenna device fixed to a dielectric substrate such that each non-powered element is located in the radiation direction as viewed from the powered element. Patent Document 3 describes an antenna of a wireless device including a second radiator installed on a cover of the wireless device for radiating a wireless signal radiated by a first radiator.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] In wireless terminals such as smartphones, a display cover is often used to protect the display and prevent peeping by others. In recent wireless terminals, an antenna module with the main radiation direction facing the display may be used. When a display cover is placed, the antenna performance of such wireless terminals may deteriorate.

[0006] One aspect of the disclosed technology aims to provide a display cover for a wireless terminal that can suppress a decrease in the antenna performance of the wireless terminal even when placed on the display and can amplify the radio waves of an antenna with the direction in which the display is placed as the main radiation direction.

Means for Solving the Problem

[0007] One aspect of the disclosed technology is exemplified by a display cover for a wireless terminal as follows. The display cover for this wireless terminal is a display cover for a wireless terminal that is placed on the display of the wireless terminal formed in a plate shape. The display cover for this wireless terminal is arranged to overlap the above display, and includes a sheet-like transparent member formed of a transparent dielectric with a relative permittivity in the range of 1 to 10, and a plurality of conductor elements arranged side by side on the transparent member with a visible light transmittance of 50% or more. The above conductor elements are formed such that the length of the longest line segment among the line segments formed on the conductor elements by connecting any two points on the conductor elements is in the range of 0.1 times to 0.4 times the length of the effective wavelength of the radio wave used by the wireless terminal for wireless communication in the above dielectric.

Effect of the Invention

[0008] The display cover for this wireless terminal can suppress a decrease in the antenna performance of the wireless terminal even when placed on the display and can amplify the radio waves of an antenna with the direction in which the display is placed as the main radiation direction.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] <Embodiment> The configuration of the embodiments shown below is an example, and the disclosed technology is not limited to the configuration of the embodiments. The display cover for a wireless terminal according to the embodiment includes, for example, the following configuration. The display cover for a wireless terminal according to the present embodiment is a display cover for a wireless terminal that is disposed on a display of the wireless terminal formed in a plate shape. This display cover for the wireless terminal is disposed so as to overlap the above display, and includes a sheet-like transparent member formed of a transparent dielectric having a relative permittivity in the range of 1 to 10, and a plurality of conductor elements arranged side by side on the transparent member and having a visible light transmittance of 50% or more. The conductor element is formed such 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 in the range of 0.1 times to 0.4 times the length of the effective wavelength of the radio wave used by the wireless terminal for wireless communication in the dielectric.

[0011] According to such a cover for the display of a wireless terminal, the conductor element can be made to operate as a resonator with respect to the antenna of the wireless terminal whose main radiation direction is directed toward the display side. And in this cover for the wireless terminal, since a plurality of conductor elements are arranged side by side, the possibility of arranging the conductor elements in the vicinity of the antenna can be increased as much as possible. That is, according to the cover for the display of this wireless terminal, the possibility of making the conductor element operate as a resonator can be increased, and as a result, the operating gain of the antenna of the wireless terminal can also be improved by making the conductor element operate as a resonator. And the conductor element of the cover for the display of this wireless terminal has a visible light transmittance of 50% or more. Therefore, even if the cover for the display of this wireless terminal is arranged on the display, the discomfort of the user with respect to the display of the display can be reduced.

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

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

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

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

[0016] The conductor element 120 is disposed at a position corresponding to an antenna module whose main radiation direction is directed toward the display side, which is provided in the smartphone to be protected by the display cover 100. The size of the conductor element 120 is determined according to the wavelength of the radio wave used for wireless communication by the smartphone accommodated in the smartphone cover 100 and the dielectric constant of the dielectric forming the sheet part 101 of the display cover 100. The conductor element 120, for example, takes into account the wavelength shortening due to the dielectric forming the sheet part 101, the glass of the smartphone, or the housing, and the effective wavelength of the radio wave of the smartphone is λ g If so, the length of the diagonal is 0.1λ g to 0.4λ g is a plate-shaped polygon, or a disc with a diameter length of 0.1λ g to 0.4λ g is. Also, the pitch interval between adjacent conductor elements 120 is preferably 0.5λ g

[0017] ​For example, when a smartphone to be protected by the display cover 100 performs wireless communication using radio waves in the millimeter wave band (frequency from 24 to 300 GHz), the effective wavelength λ in the sheet portion 101 selected from materials with a relative permittivity in the range of 1 to 10 g can be determined by the following formula (1). [Number]

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

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

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

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

[0022] In the display cover 100, the conductor element 120 is disposed on a sheet portion 101 physically separated from the millimeter-wave antenna modules 501, 502, 503, 504, and 505 to which the power supply line of the smartphone 500 is connected. The display cover 100 is configured such that the conductor element 120 operates as a resonator with respect to the radio waves radiated from the millimeter-wave antenna modules 501, 502, 503, 504, and 505. Since the conductor element 120 operates without receiving power supply physically connected from the smartphone 500, it can also be referred to as a non-powered element.

[0023] FIG. 3 is a diagram schematically showing the positional relationship between the conductor element provided in the display cover 100 according to the embodiment and the antenna of the display cover 100. FIG. 3(A) is a view of the millimeter-wave antenna module 505 and the conductor element 120 as seen from the side, and FIG. 3(B) is a view of the millimeter-wave antenna module 505 and the conductor element 120 as seen from the front. In FIG. 3(B), the millimeter-wave antenna module 505 and the patch antenna 530 provided in the millimeter-wave antenna module 505, which are not visible in the front view, are illustrated by dotted lines.

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

[0025] The patch antenna 530 resonates with radio waves having an effective wavelength λ g . Therefore, as shown in FIG. 3, the conductor element 120 positioned near the radio wave emission direction of the patch antenna 530 operates as a resonator (so-called stacked patch). By the conductor element 120 operating as a stacked patch, the cover 100 for a display can improve the operating gain of the millimeter-wave antenna module 505 of the smartphone 500.

[0026] <Simulation> Regarding the effect of the cover 100 for a display, simulations were performed and verified, 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 of the conductor element 120 were varied as parameters to verify the effect of the cover 100 for a display.

[0028] Figures 4 and 5 are diagrams for explaining each parameter used in the first simulation. In Figure 4, 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 are illustrated. In Figure 5, the length S of the diagonal line (the longest line segment) of the conductor element 120 is illustrated.

[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 distance 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. Also, the relative permittivity of the sheet portion 101 is set to 6.8, the relative permittivity of the double-sided tape 110 is set to 3.0, the relative permittivity of the display 513 is set to 6.8, and the relative permittivity of the substrate of the millimeter-wave antenna module 505 is set to 12.0. Further, in the first simulation, the thickness t1 of the sheet portion 101 is varied in the range of 0.1 mm to 1.0 mm, and the length of the longest line segment S of the conductor element 120 is varied in the range of 0.28 mm to 5.0 mm.

[0030] The results of the first simulation are illustrated in Table 1 below. In Table 1 below, 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 is illustrated. In Table 1 below, the case where the conductor element 120 is not provided (corresponding to a value of 0 mm for S in Table 1) is also illustrated. Note that in the state where the display cover 100 is not provided on the display 513 (the state where the sheet portion 101 and the conductor element 120 are absent), the gain of the patch antenna 530 was 9.54 dBi.

Table 1

[0031] The thickness of the conventional protective cover for a display is 0.15 mm to 0.33 mm, and those around 0.2 mm in thickness are widely used. Referring to Table 1 above, for example, when t1 is 0.1 mm, S is in the range of 0.56 to 3.78 mm; when t1 is 0.2 mm, S is in the range of 0.56 to 3.43 mm; when t1 is 0.3 mm, S is in the range of 1.33 to 3.43 mm. It can be understood that the gain of the patch antenna 530 is improved compared to the state where the display cover 100 is not provided on the display 513 or when only the sheet portion 101 is provided on the display 513. It can also be understood from Table 1 above that the maximum gain of 10.69 dBi was obtained 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 verified when the conductivity and thickness of the conductor element 120 were varied. FIG. 6 is a diagram illustrating the results of the second simulation. The vertical axis in FIG. 6 illustrates the operating gain of the patch antenna 530, and the horizontal axis illustrates the conductivity of the conductor element 120. In the second simulation, the thickness of the conductor element 120 was set to 400 nm, 40 nm, 4 nm, 2.2 nm, 0.4 nm, and 1.0 nm respectively, and the gain of the patch antenna 530 was verified. In FIG. 6, the operating gain of the patch antenna 530 in the state where the conductor element 120 is not provided is illustrated by a straight line L.

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

[0034] <Effects of Embodiment> When a display cover is placed on the display 513 of the smartphone 500, the operating gain of the display 513 with the radio wave emission direction facing the display 513 side may decrease. Such a problem becomes prominent in smartphones compatible with 5G that utilize millimeter-wave band radio waves.

[0035] In this embodiment, by arranging the conductor element 120 in the display cover 100 and operating the conductor element 120 as a stacked patch that is a passive element, it is possible to suppress a decrease in the operating gain of the smartphone 500 even when the display cover is placed on the display 513 of the smartphone 500.

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

[0037] Also, in this embodiment, the conductor element 120 is arranged at a position corresponding to the millimeter-wave antenna module 505 of the smartphone 500 in the sheet portion 101. By arranging the conductor element 120 in this way, it becomes easier for the conductor element 120 to be arranged at a position favorable for amplifying the operating gain of the patch antenna 530 provided in the patch antenna 530 of the millimeter-wave antenna module 505.

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

[0039] FIGS. 8 to 11 are diagrams showing variations in the positional relationship between the conductor element 120 and the patch antenna 530 in the first modification. FIGS. 8 to 11 are diagrams showing a front view of the vicinity of the conductor element 120 with the display cover 100a arranged on the display 513. In FIGS. 8 to 11, the number of the conductor elements 120 arranged on the sheet portion 101 is also varied. In the display cover 100a, a plurality of conductor elements 120 are arranged at positions where there is a high probability of the millimeter-wave antenna module 505 existing. Therefore, any one of the plurality of arranged conductor elements 120 is highly likely to be arranged in front of or in the vicinity of the patch antenna 530 provided in the millimeter-wave antenna module 505. Therefore, also according to the first modification, an improvement in the operating gain of the display cover 100a can be expected. Also, the number of the conductor elements 120 and the number of the patch antennas 530 may be the same or different.

[0040] In the embodiment and the first modification, the distance between the plurality of arranged conductor elements 120 is optimized for radio waves in the millimeter-wave band. That is, the pitch interval of the conductor elements 120 is 0.5λ gBy setting it to (0.16 to 6.25 mm), even if there is a displacement between the conductor element 120 and the patch antenna 530 provided in the millimeter-wave antenna module 505 of the smartphone 500, the conductor element 120 can be made to operate as a resonator suitable for millimeter-wave radio waves.

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

[0042] Also, FIG. 13 illustrates a conductor element 120 formed in a pentagonal shape, and FIG. 14 illustrates a conductor element 120 formed in a rectangular shape. When the conductor element 120 is a polygon including a rectangle, the longest line segment among one side or the diagonal may be 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 in a front view can be formed in various ways. And for the conductor element 120 formed in various shapes, among the line segments formed on the conductor element 120 by connecting any two points of the conductor element 120, the length of the longest line segment (also referred to as the longest line segment) may be 0.1λ g to 0.4λ g (0.032 to 5 mm).

[0043] FIG. 15 is a diagram illustrating a state in which conductor elements of various shapes are arranged. As illustrated in FIG. 15, in the display cover 100, circular or elliptical conductor elements 120 and polygonal conductor elements 120 may be provided in a mixed manner. That is, in the display cover 100, a plurality of conductor elements 120 having different shapes may be provided. Further, in the display cover 100, the conductor elements 120 may be arranged in a plurality of rows.

[0044] FIG. 16 is a diagram illustrating an arrangement pattern of the conductor elements 120. In FIG. 16, the illustration of the double-sided tape 110 is omitted. In FIG. 16(A), a state in which the conductor elements 120 are arranged on the outer surface of the sheet portion 101 (the surface opposite to the display 513) is illustrated. In FIG. 16(B), a state in which the outer surface of the sheet portion 101 is etched and the conductor elements 120 are arranged in the etched portion is illustrated. In FIG. 16(C), a state in which the inner surface of the sheet portion 101 (the surface on the display 513 side) is etched and the conductor elements 120 are arranged in the etched portion is illustrated. In FIG. 16(D), a state in which three conductor elements 120 are arranged side by side in the thickness direction of the sheet portion 101 is illustrated.

[0045] As illustrated in FIGS. 16(A) to 16(C), the conductor elements 120 may be provided on the surface of the sheet portion 101, or the surface of the sheet portion 101 may be etched (scraped) to embed the conductor elements 120. Further, 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 FIG. 16(D), by arranging the conductor elements 120 side by side in the thickness direction of the sheet portion 101, the operating gain of the patch antenna 530 can be further improved. In FIG. 16(D), three conductor elements 120 are arranged side by side in the thickness direction of the sheet portion 101, but two conductor elements 120 may be arranged side by side, or four or more conductor elements 120 may be arranged side by side.

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

[0047] FIG. 18 is a diagram illustrating a state in which the display cover 100b including the protrusion 130 is attached to the smartphone 500. In FIG. 18, the display 513 of the smartphone 500 is illustrated in an upward-facing state. When the display cover 100 is attached to the smartphone 500, the protrusion 130 is disposed on the side surface 511 of the smartphone 500. Then, since the conductor 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 operating gain of the patch antenna 530 of the millimeter-wave antenna module 502 can be improved by the display cover 100b.

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

Description of Reference Numerals

[0049] 100 ··· Display cover 100a ··· Display cover 100b ··· Display cover 101 ··· Sheet portion 110 ··· Double-sided tape 120 ··· Conductor element 130 ··· Protrusion 131··Folding 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 surface 512··Side surface 513··Display

Claims

1. A cover for a display of a wireless terminal, which is arranged on the display of the wireless terminal formed in a plate shape, a sheet-like transparent member formed of a transparent dielectric arranged so as to overlap the display and having a relative dielectric constant in the range of 1 to 10; a plurality of conductor elements arranged side by side on the transparent member and having a visible light transmittance of 50% or more, wherein the conductor element is formed such 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 in the range of 0.1 times to 0.4 times the length of the effective wavelength of the radio wave used by the wireless terminal for wireless communication in the dielectric; the plurality of conductor elements further includes additional conductor elements arranged in a plurality in the thickness direction of the transparent member, A cover for a display of a wireless terminal.

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

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

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

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

6. Each of the plurality of conductor elements is provided in the dielectric, The cover for a display of a wireless terminal according to any one of claims 1 to 5.

7. The plurality of conductor 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), The cover for a display of a wireless terminal according to any one of claims 1 to 6.

8. The transparent member is formed with a protruding portion disposed on the side surface side of the wireless terminal. The plurality of conductor elements are disposed on the protruding portion. A cover for a display of a wireless terminal according to any one of claims 1 to 7. **Claim 9** For the plurality of conductor elements, the pitch interval between adjacent conductor elements is 0.5 times the effective wavelength. A cover for a display of a wireless terminal according to claim 4. **Claim 10** The radio wave is a radio wave in the millimeter wave band. The pitch interval is within a range of 0.16 mm to 6.25 mm. A cover for a display of a wireless terminal according to claim 9. **Claim 11** The radio wave is a radio wave in the millimeter wave band. The length of the longest line segment is within a 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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