Antenna device and electronic timepiece

Abstract

The present application relates to an antenna device, comprising: a loop-shaped antenna element located in a first plane; a conductive plate for grounding located in a second plane parallel to the antenna element; a conductive member located on a side farther than a center position of the first plane where the antenna element is located and electrically connected to the antenna element; and a power supply terminal connected to the antenna element at a power supply point located within a predetermined vicinity of a boundary between a first region and a second region, the first region including an angle range symmetrical with respect to the center position and the second region including an angle range symmetrical with respect to the center position and different from the first region, the conductive member being located in at least one of the first region and the second region and configured to provide different extension widths of the antenna element and the conductive member from the center position in a distance direction in the first region and the second region.

Description

Technical Field

[0001] This invention relates to antenna devices and electronic clocks. Background Technology

[0002] In small electronic devices that receive radio waves, it is known that shortening the spacing between components to achieve miniaturization and weight reduction can affect the antenna's receiving sensitivity. Japanese Patent Application Publication No. 2019-168336 discloses a technology in which, in an electronic clock that is roughly circular when viewed from above, the angular range of the patch antenna is completely separated from the conductive components involved in the solar cell and the motor involved in driving the hands, thereby reducing the impact of other structures on the patch antenna's radio wave reception.

[0003] In recent years, the number of electronic devices that receive radio waves at multiple frequencies has also increased. When multiple frequencies are separated to the extent that an antenna with a single excitation frequency cannot completely cover the receiving band of multiple frequencies, simply configuring multiple antennas in a way that allows both to have the receiving sensitivity can sometimes result in these antennas taking up space and hindering miniaturization and weight reduction. Summary of the Invention

[0004] An antenna device according to an embodiment of the present invention includes:

[0005] A ring-shaped antenna element located in a certain first plane;

[0006] A grounding conductive plate is located on a second plane parallel to the aforementioned antenna element;

[0007] A conductive component, located further away from the center of the first plane where the antenna element is situated, and electrically connected to the antenna element; and

[0008] A power supply terminal, which connects to the aforementioned antenna element at the power supply point.

[0009] The aforementioned power supply point is located within a predetermined vicinity of the boundary between the first region and the second region. The first region each includes an angular range symmetrical with respect to the aforementioned central position, and the second region each includes an angular range symmetrical with respect to the aforementioned central position but different from the aforementioned first region.

[0010] The conductive component is located in at least one of the first region and the second region, and is configured such that the extension width in the distance direction from the center position obtained by the antenna element and the conductive component is different in the first region and the second region.

[0011] An antenna device according to an embodiment of the present invention includes:

[0012] A ring-shaped antenna element located in a certain first plane;

[0013] A grounding conductive plate is located on a second plane parallel to the aforementioned antenna element;

[0014] A conductive component, not electrically connected to the antenna element, is positioned between the antenna element and the conductive plate in a height direction perpendicular to the first plane, and faces both the antenna element and the conductive plate respectively; and

[0015] A power supply terminal, which connects to the aforementioned antenna element at the power supply point.

[0016] The aforementioned power supply point is located within a predetermined vicinity of the boundary between the first region and the second region. The first region respectively includes a certain angular range symmetrical with respect to the center position of the first plane where the antenna element is located. The second region respectively includes a certain angular range symmetrical with respect to the center position and different from the first region.

[0017] The conductive component is located in at least one of the first region and the second region, which correspond to different frequencies of the receiving object, and is configured such that the characteristics related to the capacitance between the antenna element and the conductive plate are different in the first region and the second region. Attached Figure Description

[0018] Figure 1A This is a top view of an electronic clock.

[0019] Figure 1B This is a bottom view of an electronic clock.

[0020] Figure 2A This is a top view of an electronic clock used to illustrate the first example of an antenna structure.

[0021] Figure 2B This is a cross-sectional view of an electronic clock used to illustrate the first example of an antenna structure.

[0022] Figure 3A This is a top view of an electronic clock used to illustrate the antenna structure in the second example.

[0023] Figure 3B This is a cross-sectional view of an electronic clock used to illustrate the antenna structure in the second example.

[0024] Figure 4A This is a top view of an electronic clock used to illustrate the third example of antenna structure.

[0025] Figure 4B This is a cross-sectional view of an electronic clock used to illustrate the antenna structure in the third example.

[0026] Figure 5 This is a top view of an electronic clock used to illustrate the fourth example of antenna structure.

[0027] Figure 6A This is a top view of an electronic clock used to illustrate the antenna structure in the fifth example.

[0028] Figure 6B This is a cross-sectional view of an electronic clock used to illustrate the antenna structure in the fifth example. Detailed Implementation

[0029] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0030] Figure 1A , Figure 1B These are top and bottom views of the electronic clock 1 having the antenna device of this embodiment.

[0031] like Figure 1A As shown in the top view, the electronic clock 1 has a housing 2, a display screen 5, and operation receiving components such as push-button switches B1-B3 and a crown C1 to receive external operations. In the display screen 5, a rotatable pointer 51 is mounted, and content corresponding to the direction pointed by the pointer 51 is displayed. The display content of the electronic clock 1's display screen 5 includes the time (or date and day of the week, etc.).

[0032] The housing 2 has a cylindrical shape with open upper and lower surfaces. Inside, in addition to housing the display screen 5, it also houses a satellite radio wave receiving and processing unit (operation unit) that performs positioning calculations using radio waves received from the bezel 11, a control unit that controls the content displayed on the display screen 5, a drive unit related to the display screen 5 (the drive unit and display screen 5 are combined into a single display unit), a battery, etc. The upper surface of the display screen 5 (the upper end of the housing 2) is covered by a transparent windproof component (not shown in the illustration). The push-button switches B1-B3 and the crown C1 penetrate the openings on the side of the housing 2, with their front ends exposed to the outside. The 12 o'clock and 6 o'clock directions of the housing 2 are the directions in which the strap mounting part 2a extends outward from the display screen 5. Here, the housing 2 is an insulating component (insulating material; resin, ceramic, etc.).

[0033] Above the display screen 5, the windshield component is surrounded by a bezel 11. This bezel 11 may also have markings indicated by the pointer 51. Furthermore, in addition to its decorative purpose, the bezel 11 also functions as an antenna element as described below.

[0034] like Figure 1BAs shown in the bottom view, the lower end of the housing 2 is sealed by the back cover 3 (conductive plate). The back cover 3 is a conductive component (e.g., various stainless steel, titanium, and other metal components) that is grounded by contacting the user's wrist, which serves as the ground plane of the housing.

[0035] Next, the antenna structure of this embodiment will be described.

[0036] In the electronic clock 1 of this embodiment, a single antenna is used to receive radio waves of multiple frequencies. For example, as radio waves from positioning satellites, the electronic clock 1 receives radio waves in the L1 band (1.57542 GHz; second frequency) and the L5 band (1.17645 GHz; first frequency) involved in GPS (Global Positioning System). These frequencies, i.e., wavelengths, differ by nearly 30%. Furthermore, from the perspective of design and practical use, it is difficult to change (increase) the overall size of the electronic clock 1 to match the receiving wavelength of the antenna.

[0037] In the electronic clock 1, the annular bezel 11 is divided into regions in two orthogonal directions. That is, two diagonal blocks in each of the four 90-degree sections (with the directions of 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock as the centers) are each considered as the same region. Furthermore, by making the electrical length along the direction of the line connecting the centers of each region correspond to the wavelengths of the two receiving frequencies (e.g., λ / 8), multiple wavelengths of radio waves can be received. In addition, the radio waves transmitted from GPS positioning satellites (GPS satellites) are right-hand circularly polarized waves, but in the above-described reception, they are received as linearly polarized waves. It is necessary to make the direction of each region different from the direction from the center of the electronic clock 1 (bezel 11) to the connection point (power supply point) connected to the power supply terminal.

[0038] Figure 2A , Figure 2B This is a diagram illustrating the first example of an antenna structure. In subsequent diagrams, the outline of housing 2 is shown in a simplified manner. Furthermore, illustrations and explanations of structures not required for radio wave reception are appropriately omitted.

[0039] like Figure 2AAs shown, the antenna element viewed from above (top view) is an annular bezel 11 located on the upper side of the housing 2 within a plane (first plane) parallel to the surface containing the rear cover 3 (second plane). Alternatively, the antenna element can be a dedicated conductor component other than the bezel. The power supply point connected to the power supply terminal 12 is located at the 1:30 direction of the bezel 11. The 1:30 direction is the average of the first and second diameter directions described below (the average direction of the diameter direction (full width direction) without distinguishing between the start and end points is one of two in the plane, but either one can be chosen). It operates as a microstrip antenna in combination with the rear cover 3, which exists parallel to the bezel 11 and serves as a ground plane (housing ground).

[0040] When viewed from above (hereinafter, "viewed from above" includes cases where it is not actually visible from above (perspective view)), the bezel 11 can be divided into four blocks at 90-degree intervals (not physically divided) by a straight line (reference line) passing through the power supply terminal 12 and the center position O of the bezel 11, and a straight line orthogonal to it and passing through the center position O (the above two lines are shown by a single-dotted line). The center of each block is at the 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock positions (shown by dotted lines).

[0041] Within the second region, which comprises two blocks—one at the 3 o'clock direction (90 degrees from 1:30 to 4:30, a certain angular range) and the other at the 9 o'clock direction (90 degrees from 7:30 to 10:30)—radio waves of a wavelength corresponding to the diameter of the bezel 11 are received as the second frequency. This second frequency is the higher frequency of the two receiving frequencies, specifically the L1 band in this case.

[0042] Furthermore, in the region (first region) comprising two blocks—the 12 o'clock direction (90 degrees from 10:30 to 1:30, a certain angular range) and the symmetrical 6 o'clock direction (90 degrees from 4:30 to 7:30)—metal components 13a and 13b respectively contact the outer side of the bezel 11 (the side farther from the center position O), thereby establishing an electrical connection. Metal components 13a and 13b can be fixed to the bezel 11 by bonding with solder or the like, or they can be fixed by pressing from the outside by other components without bonding. Furthermore, within the aforementioned first region, below the position where they overlap with the bezel 11 when viewed from above, metal components 14a and 14b exist separately from the bezel 11.

[0043] The metal components 13a, 13b, 14a, and 14b located around the bezel 11 are adjustment components used to adjust the frequency (receiving frequency) of the radio waves received by the bezel 11. The metal components 13a, 13b, 14a, and 14b are, for example, stainless steel; as explained below, they may also be made of copper, silver, etc., in the case of a grounding film on the substrate; and the exposed parts may be made of titanium, etc. Furthermore, they may not be a single type of material, but may be a mixture of multiple types of materials. Also, some or all of the metal components 13a, 13b, 14a, and 14b may be made of the same material as the back cover 3, or they may be made of a different material.

[0044] Because the metal parts 13a and 13b that contact the bezel 11 increase the width (extension width) of the distance from the center position O of the radio wave receiving surface in the distance direction, the wavelength of the received radio wave is longer, i.e., the excitation frequency is lower, in relation to the first region including the 12 o'clock direction, the center position O of the bezel 11, and the 6 o'clock direction and the first diameter direction (first full width direction) that crosses the bezel 11, compared to the second region including the 3 o'clock direction, the center position O, and the 9 o'clock direction and the second diameter direction (second full width direction) that crosses the bezel 11. The metal parts 13a and 13b can also extend to the mounting portion 2a of the watch strap. However, as described above, it is difficult to significantly increase the size of the metal parts 13a and 13b.

[0045] like Figure 2B Sectional view (only showing along) Figure 2A As shown in the cross-sectional line AA and the related structure, metal parts 14a and 14b have a thickness dc and are located between the bezel 11 and the back cover 3. This reduces the distance (d1+dc+d2) between the back cover 3 and the bezel 11, which forms the ground plane, by an amount corresponding to the thickness dc of the metal parts 14a and 14b, thereby increasing the capacitance between the back cover 3 and the bezel 11, which depends on this distance. Furthermore, if the metal parts 14a and 14b are grounded (at the same potential as the back cover 3), the distance is essentially only the distance d1 between the metal parts 14a and 14b and the bezel 11, thus further increasing the capacitance. As a result, the electrical length on the bezel 11 is extended, allowing for the excitation of lower frequency radio waves with longer wavelengths even at the same size. When receiving (transmitting) high-frequency (including the GHz band of reception) radio waves, the influence of the aforementioned characteristics related to the capacitance in each polarization direction becomes greater than the static capacitance of the entire bezel 11. Therefore, the aforementioned metal parts 14a, 14b, 13a, and 13b are appropriately arranged to appropriately adjust the frequency of the radio waves excited in the direction along each cross section, thereby enabling reception of the lower frequency side of the two reception frequencies, i.e., the L5 band of reception in this case.

[0046] Figure 3A, Figure 3B This is a diagram illustrating the second example of an antenna structure.

[0047] The metal components don't necessarily have to be located at the 12 o'clock and 6 o'clock positions respectively. They can also be arranged as follows: Figure 3A As shown, for example, the circuit board 14c located inside the housing 2 extends in the 12 o'clock and 6 o'clock directions to the space between the bezel 11 and the back cover 3. Figure 3B As shown, the extended portion of the circuit board 14c has conductive surfaces (metal components) on both sides and is electrically connected to each other, thereby having the same function as the metal components 14a and 14b described above. The conductive surfaces can also be the usual ground plane of the circuit board 14c. The electrical connection is not particularly limited and through holes can be used. In addition, metal components 14a and 14b may also be present between the circuit board 14c and the bezel 11 as needed.

[0048] Figure 4A , Figure 4B This is the third example of an illustration of an antenna structure.

[0049] like Figure 4A As shown, metal components 14d and 14e are each divided into multiple (e.g., two) parts (separate from each other). Since other structures are also housed inside the housing 2, metal components 14d and 14e can also be separately located within a portion of the area that can exist based on their positional relationship with the aforementioned components. In this case, the shapes of the multiple metal components 14d and 14e can also be different from each other.

[0050] Furthermore, the aforementioned metal components 14d, 14e, etc., can be hollow or frame-shaped. For example... Figure 4B As shown, for example, metal components 14d and 14e are frame-shaped structures that extend vertically through the through-hole H and are parallel to the first plane containing the bezel 11. The upper and lower edges of the frame are electrically connected, and there are no openings on the surfaces opposite to the bezel 11 and the back cover 3, respectively. That is, the opposing area does not decrease. Therefore, by using the sum of the distance between the upper edge and the bezel 11 and the distance between the lower edge and the back cover 3, a large capacitance is obtained compared to the volume.

[0051] Figure 5 This is the fourth example of an illustration of an antenna structure.

[0052] The metal component located between the bezel 11 and the back cover 3 may include conventional components such as push-button switches B1-B3 and the crown C1. Here, the power supply terminal 12 is located at the 4:30 position, and within a range (first region) rotated 90 degrees counterclockwise from the reference line corresponding to the position of the power supply terminal 12, push-button switches B1-B3, the crown C1, and metal components 14f and 14g are respectively located. Push-button switches B1-B3 and the crown C1 are sometimes grounded using springs or the like as a static electricity countermeasure, but mechanisms that can stably maintain the grounding state may also be used, or conversely, a structure in which the housing is not grounded under normal circumstances may be used, so that during reception, the presence or absence of housing grounding will not change due to pressing the push-button switches B1-B3 or rotating the crown C1, thereby keeping the excitation frequency and reception gain unchanged.

[0053] The positions of push-button switches B1-B3 and the crown C1 are determined based on user convenience, so they cannot be significantly offset. However, fine adjustments such as changing the thickness of the shaft (making it thicker) can be made according to the frequency of the receiving object. Furthermore, the position of the power supply point can be determined by considering the positions of push-button switches B1-B3 and the crown C1, as in the example above.

[0054] Furthermore, in the above description, the following situation was explained: receiving high-frequency (second frequency) radio waves within a range of 90 degrees clockwise relative to the reference line when viewed from above, and receiving low-frequency (first frequency) radio waves within a range of 90 degrees counterclockwise relative to the reference line when viewed from above (this is the same positional relationship as the reception of normally right-hand circularly polarized waves). However, as mentioned above, since the electronic clock 1 of this embodiment can receive radio waves as linearly polarized waves even if the received radio wave is circularly polarized, the location of the low-frequency and high-frequency receiving areas relative to the position (angular direction) of the power supply terminal 12 is irrelevant. That is, the positional relationship of the first and second areas relative to the reference line in the above description of the embodiment can also be reversed. It is sufficient to be able to appropriately receive high-frequency and low-frequency radio waves in a direction of approximately ±45 degrees from the reference line. Furthermore, since the position is not selectively detected at ±45 degrees from the baseline, the adjustment can be made in a way that obtains the gain of the second frequency radio wave on the high-frequency side and the first frequency radio wave on the low-frequency side within a range of approximately ±90 degrees from the baseline.

[0055] Furthermore, the direction in which the highest gain is obtained relative to the desired excitation frequency is also affected by various components located inside the housing 2 (wiring of the wiring board, ground plane, cables, threaded parts, screws, helical springs, leaf springs, electronic devices, support frames (frames) for fixing the substrate, etc.). Therefore, it is theoretically difficult to determine the size and position of the metal parts, so the optimal size and position of the above-mentioned parts can be determined as needed by using numerical analysis (simulation) and based on the results of experiments or tests.

[0056] Figure 6A , Figure 6B This is the fifth example of an illustration of an antenna structure.

[0057] like Figure 6A , Figure 6B As shown, the metal components do not necessarily have to be positioned overlapping the bezel 11 when viewed from above, as described above. Here, the outer edge of the circuit board 14h is positioned approximately at the same level as the inner edge of the bezel 11 in the 12 o'clock and 6 o'clock directions when viewed from above, and they do not overlap. Even with such a degree of contact (or partial overlap) when viewed from above (a large separation would be meaningless), the conductors of the circuit board 14h can contribute to an increase in capacitance. In cases where the bezel 11 is located on the housing 2, etc., by making the shape of the circuit board 14h located inside the housing 2 (along the inner wall surface) and the extent of the ground plane anisotropic, the excitation frequency can be dispersed into multiple frequencies, enabling the reception of radio waves of these multiple frequencies.

[0058] As described above, the electronic clock 1 including the antenna device of this embodiment includes an annular bezel 11 located in a first plane, a back cover 3 for grounding (or housing grounding) located in a second plane parallel to the bezel 11, metal parts 13a, 13b, etc. located further away from the center position O of the bezel 11 and electrically connected to the bezel 11, and a power supply terminal 12 connected to the bezel 11 at a power supply point. The power supply point is located in the vicinity of a first region (e.g., the 12 o'clock direction, the 6 o'clock direction) that respectively includes an angular range symmetrical with respect to the center position O, and a second region (e.g., the 3 o'clock direction, the 9 o'clock direction) that respectively includes an angular range symmetrical with respect to the center position O and different from the first region. The metal parts 13a, 13b, etc. are located in at least one of the first region and the second region, so that the expansion width from the center position O obtained by the bezel 11 and the metal parts 13a, 13b in the distance direction is different in the first region and the second region.

[0059] In this way, the bezel 11, as a single antenna element, maintains its shape corresponding to a single receiving frequency, while the metal components are appropriately positioned around the bezel 11. This locally reduces the excitation frequency involved in receiving linearly polarized waves, allowing excitation from the peripheral frequencies of the two frequencies of the receiving target, depending on the direction. Therefore, in addition to receiving radio waves at the excitation frequency corresponding to the original size of the bezel 11, it is also easy to simultaneously receive radio waves at frequencies lower than that excitation frequency. Furthermore, compared to manufacturing the bezel 11 with a complex shape, the shape and position of the metal components 13a and 13b can be flexibly determined.

[0060] Furthermore, the electronic clock 1, which includes antenna devices in other embodiments, in addition to the aforementioned bezel 11, back cover 3, and power supply terminal 12, also includes conductive metal components 14a and 14b, which are not electrically connected to the bezel 11 and are positioned in the height direction perpendicular to the first plane, between the bezel 11 and the back cover 3, and respectively facing the bezel 11 and the back cover 3. The metal components 14a and 14b are located in at least one of a first region and a second region corresponding to different receiving frequencies, causing the capacitance characteristics between the bezel 11 and the back cover 3 to differ between the first and second regions. The term "facing" here is not limited to the case where the facing surfaces are parallel to each other, but also includes the case where one surface is inclined relative to the other. By clamping a conductor of thickness between the bezel 11 of the microstrip antenna and the ground plane in this way, the substantial distance between the antenna element and the ground plane can be shortened, the capacitance can be increased, and thus the excitation frequency can be reduced in a certain direction, enabling efficient reception of the original excitation frequency and both frequencies by a single antenna element and a single power supply terminal.

[0061] Furthermore, when viewed from above (including parts that are not actually visible from a perspective), at least a portion of the metal parts 14a and 14b overlaps with the bezel 11. This allows for a more effective increase in the capacitance between the bezel 11 and the back cover 3.

[0062] Furthermore, multiple metal parts can be arranged as in the manner of metal parts 14d and 14e. Since more components are located within the housing 2 compared to the size of the electronic clock 1, even in the absence of space to insert larger metal parts 14a, 14b, etc., of the same size, it is possible to receive radio waves with an excitation frequency lower than that of the original bezel 11 without difficulty and effectively by properly inserting smaller metal parts 14d and 14e in combination within the area containing multiple components.

[0063] Furthermore, conductive components (metal components) can also be conductive surfaces (ground surfaces) located on both sides of the substrate and electrically connected, as in circuit board 14c. By slightly altering the shape of the circuit board within the limits of possibility, the conductive surfaces can be easily fixed at the desired locations.

[0064] Furthermore, by making the first diameter direction (12 o'clock and 6 o'clock directions) orthogonal to the second diameter direction (3 o'clock and 9 o'clock directions), the receiving portions of multiple frequencies of radio waves received by the bezel 11 (antenna element) can be separated to a greater extent, thus making it easy and appropriate to configure the metal parts 13a, 13b, 14a, and 14b.

[0065] Furthermore, the power supply point is located in the average direction of the first and second diameter directions (at the 1:30 o'clock position on the baseline). Since the power supply terminals 12 are connected at positions that are equally separated from the two directions, the gain of multiple wavelengths of radio waves can be improved in a balanced manner.

[0066] Furthermore, the electronic clock 1 may also include a housing 2, which internally houses a satellite radio wave receiving and processing unit that serves as the actuator for transmitting and receiving radio waves using the bezel 11 (here, the receiving unit). The conductive plate is the back cover 3 of the housing 2. Even when it is difficult to prepare a dedicated ground plane, radio wave reception can be performed in a space-saving manner by using the cover as a ground plane in this way. In particular, in the watch-shaped electronic clock 1, since the back cover 3 is easily in contact with the human body, it is easy to properly ground.

[0067] Furthermore, the electronic clock 1 of this embodiment includes the aforementioned antenna device, a display unit located inside the housing 2, and a control unit, the control unit causing the display unit to display the time.

[0068] In electronic clocks and watches 1 (especially wristwatches), since the antenna element described above can be configured to receive radio waves of multiple frequencies when the bezel 11 is a single unit, space can be saved and the received (communication) radio waves can be utilized more efficiently.

[0069] Furthermore, the conductive components (metal components) may also include push-button switches B1 to B3, crown C1, etc., which serve as operation receiving components for receiving operations from the outside. By appropriately combining and using the existing metal components, it is possible to receive (transmit) radio waves of multiple frequencies while suppressing the increase in size.

[0070] Furthermore, the first region includes the 12 o'clock and 6 o'clock directions, and the second region includes the 3 o'clock and 9 o'clock directions. In the electronic clock 1, the watch strap is installed in the 12 o'clock and 6 o'clock directions, which makes it easy to slightly increase (lengthen) the main body of the case 2, etc. Therefore, by positioning the metal parts 13a, 13b, etc. in this direction, the impact on the design of the electronic clock 1 can be minimized.

[0071] Furthermore, the present invention is not limited to the above-described embodiments and various modifications can be made.

[0072] For example, in the above embodiment, the example was described where the metal component is selectively present only in the region receiving the lower frequency, but it could also be as in the first example. Figure 2A , Figure 2B As shown, metal components such as the operating receiving unit are also present in the region where the higher frequency is received. In this case, the diameter of the bezel 11 (antenna element) can be made smaller overall, but in the region where radio waves at the lower frequency are received, more metal components are needed to significantly reduce the excitation frequency.

[0073] Furthermore, the example given is that the ring-shaped antenna of the bezel 11 is circular, but it can also be angular (rectangular, polygonal, or a shape with rounded corners, etc.) depending on the shape of the housing 2, or elliptical when viewed from above.

[0074] Furthermore, in the above embodiment, an example was described where the first diameter direction (12 o'clock / 6 o'clock direction) and the second diameter direction (3 o'clock / 9 o'clock direction) are orthogonal, and a power supply point exists in their average direction (1.5 o'clock direction). However, since the two radio waves are independent, it is not necessary to excite them separately in orthogonal directions. If the angle between the power supply point and the reference line involved is obtained, and the angle between the two is also obtained, then it is also possible to deviate slightly (e.g., less than 10 degrees) from the orthogonal direction. Moreover, the position of the power supply point is also within the range where the angle between the reference line and the first diameter direction and the second diameter direction will not decrease, and it deviates slightly from the average (middle) direction (the boundary between the first region and the second region) of the first diameter direction and the second diameter direction, for example, deviating less than 5 degrees. Depending on the situation, it may also deviate within a range of less than 15 degrees (near the predetermined angle).

[0075] Furthermore, in the third example of the above embodiment, hollow or frame-shaped metal parts 14d and 14e are shown. However, other structures are also possible if the opposing areas opposite the bezel 11 and the back cover 3 are appropriately obtained, and the two opposing surfaces are electrically connected. (The direction of the through hole in the frame can also be inclined (or vertical). Furthermore, the two opposing surfaces may not be in the same position when viewed from above.)

[0076] Furthermore, the above embodiment was described using an example where only a metal component exists between the bezel 11 and the back cover 3, but it is not limited to this. For example, in the case where the inner wall surface of the housing 2 has irregularities and a metal component is embedded in the recess, insulating material is inserted between the metal component and the bezel 11 and the back cover 3, respectively. Alternatively, other insulating material components may exist between the metal component and the bezel 11 and the back cover 3.

[0077] Furthermore, in the above embodiments, as metal components separated from the bezel 11 within the housing 2, examples include dedicated components, ground planes on the substrate, and operation receiving components. However, threaded components, springs, frames, etc., which are other metal components, may also be intentionally arranged in the manner described above.

[0078] Furthermore, if the excitation frequency corresponding to the two receiving frequencies can be obtained by any one of the metal parts 13a, 13b and metal parts 14a, 14b, etc., then it is also possible to have an electronic clock 1 that only has that one part.

[0079] Furthermore, in the above embodiments, the rear cover 3 was described as an example of a conductive plate, but it is not limited to this. For example, the ground plane of the circuit board that carries the satellite radio wave receiving and processing unit, the control unit, and the drive unit may also be a conductive plate, and the metal parts are located between the bezel 11 and the circuit board in a grounded or floating state.

[0080] Furthermore, in the above embodiment, the example of receiving radio waves from a positioning satellite was used, but it can also be an antenna used to receive and transmit other radio waves.

[0081] Furthermore, display screen 5 may not be a pointer-based display screen, but rather a digital display screen such as an LCD monitor.

[0082] Furthermore, while the above embodiment uses a wristwatch-shaped electronic clock 1 as an example, it is not limited to this. It could also be other electronic devices that do not have a time display function or where time display is not a primary function, particularly wearable terminals such as activity meters.

[0083] In addition, the specific structure, processing actions, and operation sequence shown in the above embodiments can be appropriately changed without departing from the spirit of the present invention.

[0084] Several embodiments of the present invention have been described, but the scope of the present invention is not limited to the above embodiments, but includes the scope of the invention as set forth in the claims and its equivalents.

Claims

1. An antenna device, characterized in that, have: A ring-shaped antenna element located in a certain first plane; A grounding conductive plate is located on a second plane parallel to the aforementioned antenna element; A conductive component, not electrically connected to the antenna element, is positioned between the antenna element and the conductive plate in a height direction perpendicular to the first plane, and faces both the antenna element and the conductive plate respectively; and A power supply terminal, which connects to the aforementioned antenna element at the power supply point. The aforementioned power supply point is located within a predetermined vicinity of the boundary between the first region and the second region. The first region respectively includes a certain angular range symmetrical with respect to the center position of the first plane where the antenna element is located. The second region respectively includes a certain angular range symmetrical with respect to the center position and different from the first region. The conductive component is located in at least one of the first region and the second region, which correspond to different frequencies of the receiving object, and is configured such that the characteristics related to the capacitance between the antenna element and the conductive plate are different in the first region and the second region.

2. The antenna device according to claim 1, characterized in that, When viewed from above, at least a portion of the aforementioned conductive component overlaps with the aforementioned antenna element.

3. The antenna device according to claim 1, characterized in that, Multiple of the aforementioned conductive components are arranged in a row.

4. The antenna device according to any one of claims 1 to 3, characterized in that, The aforementioned conductive components are conductor surfaces located on both sides of the substrate and electrically connected to each other.

5. The antenna device according to any one of claims 1 to 3, characterized in that, The first diameter direction of each of the aforementioned angle ranges in the first region, which serves as the angle bisector of that angle, is orthogonal to the second diameter direction of each of the aforementioned angle ranges in the second region, which serves as the angle bisector of that angle.

6. The antenna device according to any one of claims 1 to 3, characterized in that, The aforementioned power supply points are located in the first diameter direction of the angle bisector of the aforementioned angle range in the first region and in the second diameter direction of the aforementioned angle range in the second region.

7. The antenna device according to any one of claims 1 to 3, characterized in that, It includes a housing that internally houses the operating part of at least one of the antenna elements used for transmitting and receiving radio waves. The aforementioned conductive plate is the rear cover of the housing.

8. An electronic clock, characterized in that, have: The antenna device according to claim 7; and The display unit and control unit are located within the aforementioned housing. The aforementioned control unit causes the aforementioned display unit to display the time.

9. The electronic clock according to claim 8, characterized in that, The aforementioned conductive component includes an operation receiving component that accepts operations from external sources.

10. The electronic clock according to claim 8 or 9, characterized in that, The first area mentioned above includes the 12 o'clock and 6 o'clock directions, and the second area mentioned above includes the 3 o'clock and 9 o'clock directions.

Images