Electronic timepiece

Abstract

An electronic timepiece, in a case where electronic timepieces having different sizes of cases are constituted, can prevent an increase in cost and can improve reception performance. An electronic timepiece characterized by having: a case; a hand; a dial; a drive mechanism that drives the hand; a bottom plate on which the drive mechanism is mounted; an antenna that is disposed between the dial and the bottom plate when viewed from a direction parallel to a surface of the dial; and a circuit substrate, the antenna having: a plate-shaped radiating electrode; a plate-shaped ground electrode; and a dielectric that is disposed between the radiating electrode and the ground electrode when viewed from the direction, the circuit substrate being in conduction with the radiating electrode via a power supply member, the radiating electrode having a portion that protrudes outward of the bottom plate when viewed from a direction perpendicular to the surface of the dial.

Description

Technical Field

[0001] This invention relates to electronic clocks with built-in antennas. Background Technology

[0002] In small electronic watches such as wristwatches, it is known that some electronic watches have built-in antennas for receiving satellite signals. For example, Patent Document 1 discloses an electronic watch with a flat antenna disposed between the dial and the base plate. This antenna has a radiating conductor, a grounding conductor, and a shorting portion that connects these conductors. Electronic watches with such built-in antennas generally use dedicated movements corresponding to the size of their respective cases.

[0003] On the other hand, in electronic clocks without built-in antennas, as disclosed in Patent Document 2, it is known that various electronic clocks with different case sizes are constructed at low cost using a common movement and a frame of different sizes.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2020-30056

[0005] Patent Document 2: Japanese Patent Application Publication No. 2016-114552

[0006] Considering the mechanism with a flat antenna in Patent Document 1, which uses the mid-frame disclosed in Patent Document 2, an electronic clock with an antenna built-in in a different housing size can be constructed.

[0007] However, since a common core module is used, the antenna size is also common, which presents the challenge of not being able to improve reception performance.

[0008] Therefore, in the case of electronic clocks with built-in antennas that have different housing sizes, a structure that can prevent increased costs and improve reception performance is required. Summary of the Invention

[0009] The electronic clock disclosed herein is characterized by having: a housing; hands; a dial; a drive mechanism that drives the hands; a base plate on which the drive mechanism is mounted; an antenna disposed between the dial and the base plate when viewed from the side in a direction parallel to the surface of the dial; and a circuit board, the antenna having: a plate-shaped radiating electrode; a plate-shaped ground electrode; and a dielectric disposed between the radiating electrode and the ground electrode when viewed from the side, the circuit board being connected to the radiating electrode via a power supply component, the radiating electrode having a portion that protrudes outward from the base plate when viewed from a direction perpendicular to the surface of the dial.

[0010] The electronic clock disclosed herein is characterized by having: a housing; hands; a dial; a drive mechanism that drives the hands; a base plate on which the drive mechanism is mounted; an antenna disposed between the dial and the base plate when viewed from the side in a direction parallel to the surface of the dial; and a circuit board, the base plate having: a first region on which the drive mechanism is mounted; and a second region disposed on the outer periphery of the first region and abutting against the housing; the antenna having: a plate-shaped radiating electrode; a plate-shaped grounding electrode; and a dielectric disposed between the radiating electrode and the grounding electrode when viewed from the side; the circuit board being connected to the radiating electrode via a power supply component; the dial being formed to a size corresponding to the housing; and the radiating electrode having a portion overlapping the second region when viewed from a direction perpendicular to the surface of the dial. Attached Figure Description

[0011] Figure 1 This is a front view showing the electronic clock of the first embodiment.

[0012] Figure 2 This is a cross-sectional view of the electronic clock according to the first embodiment.

[0013] Figure 3 This is a perspective view showing the antenna, solar panel, and circuit board of the electronic clock according to the first embodiment.

[0014] Figure 4 This is a top view showing the antenna and solar panel of the electronic clock according to the first embodiment.

[0015] Figure 5 This is a cross-sectional view of a reference electronic clock.

[0016] Figure 6 This is a top view showing the antenna and solar panel of an electronic clock as an example.

[0017] Figure 7 It is a graph showing the relationship between antenna diameter and antenna gain.

[0018] Figure 8 This is a cross-sectional view of the electronic clock according to the second embodiment.

[0019] Figure 9 This is a top view showing the antenna and solar panel of the second embodiment.

[0020] Figure 10 This is a cross-sectional view of the electronic clock according to the third embodiment.

[0021] Figure 11 This is a top view showing the antenna and solar panel of the third embodiment.

[0022] Label Explanation

[0023] 1: Electronic clock; 1B: Electronic clock; 1C: Electronic clock; 1D: Electronic clock; 2: Dial; 2D: Dial; 3: Hands; 5: Date wheel; 10: Case; 10D: Case; 20: Movement; 21: Base plate; 21C: Base plate; 23: Drive mechanism; 24: Secondary battery; 25: Solar panel; 25C: Solar panel; 28: Middle frame; 31: Hour hand; 32: Minute hand; 33: Second hand; 50: Planar antenna; 50B: Planar antenna; 50C: Planar antenna; 50D: Planar antenna; 51: Dielectric; 51B: Dielectric; 51C: Dielectric; 52: Radiation electrode; 52B 52C: Radiation electrode; 52D: Radiation electrode; 53: Ground electrode; 53B: Ground electrode; 53C: Ground electrode; 54: Shorting part; 54B: Shorting part; 54C: Shorting part; 56: Power supply pin; 70: Circuit board; 81: Magnetic plate; 82: Circuit pressure plate; 211: First region; 212: Second region; 251: Conducting component; 252: Conducting component; 252A: First helical spring; 252B: Second helical spring; 252C: Connecting part; 502: Recess; 521: Outer peripheral part; 521B: Outer peripheral part; 522: Outer peripheral part; 522B: Outer peripheral part. Detailed Implementation

[0024] [First Implementation Method]

[0025] The electronic clock 1 according to the first embodiment will now be described with reference to the accompanying drawings. In this embodiment, the side of the glass cover 15 of the electronic clock 1 will be described as the front side or the top side, and the side of the back cover 14 will be described as the back side or the bottom side. Furthermore, top view refers to viewing the electronic clock 1 from a direction perpendicular to the surface of the dial 2, i.e., along the axis of the pointer axes 35-37 (described later), while side view refers to viewing the electronic clock 1 from a direction parallel to the surface of the dial 2.

[0026] The electronic clock 1 of this embodiment is configured to have a built-in planar antenna 50, which receives satellite signals from multiple GPS satellites or quasi-zenith satellites or other position information satellites S that orbit the Earth in a predetermined orbit to obtain satellite time information and can correct internal time information.

[0027] like Figure 1 , 2 As shown, the electronic clock 1 has a housing 10, a dial 2 housed within the housing 10, hands 3, and a date wheel 5. The electronic clock 1 also has a crown 6 for external operation and two buttons 7 and 8.

[0028] [External Structure of Electronic Clocks]

[0029] The case 10 has a case body 11 and a back cover 14. The case body 11 has a cylindrical case 12 and an annular bezel 13 disposed on the front side of the case 12. In this embodiment, the case 12 and the back cover 14 are separate components, but this is not a limitation; the case 12 and the back cover 14 can also be a single integrated case. Alternatively, in this embodiment, the case 12 and the bezel 13 are separate components, but this is not a limitation; an integrated structure of the case 12 and the bezel 13 can also be used, which offers the advantage of lower cost.

[0030] The case 12, bezel 13, and case back 14 are made of stainless steel, titanium alloy, aluminum, brass, and other conductive metals.

[0031] A glass cover 15 is mounted on the bezel 13 via a plastic gasket 17. The glass cover 15 is made of transparent materials such as mineral glass, sapphire glass, or acrylic glass.

[0032] The diameter of the glass cover 15, i.e. the glass diameter, is determined by the size of the shell 10, and the thickness of the glass cover 15 is determined by the relationship between the glass diameter and the waterproof performance.

[0033] [Internal structure of electronic clocks]

[0034] Next, the internal structure of the housing 10 built into the electronic clock 1 will be described.

[0035] like Figure 2 As shown, the dial 2, dial ring 16, movement 20, etc. are housed inside the housing 10.

[0036] The dial 2 is formed into a circular plate shape from a non-conductive component. In this embodiment, the dial 2 is formed from polycarbonate resin with a relative permittivity of 3. The dial 2 is formed to a size corresponding to the housing 10. That is, the planar dimension of the dial 2, i.e., the diameter of the dial 2 when viewed from above, is set according to the inner diameter of the housing 10. In the electronic clock 1, the planar dimension of the dial 2 is larger than the planar dimension of the base plate 21 described later, and it overlaps with a portion of the middle frame 28 when viewed from above.

[0037] like Figure 2 As shown, the hands 3 have an hour hand 31, a minute hand 32, and a second hand 33. A through hole 2A is formed in the center of the plane of the dial 2, and three coaxially arranged pointer shafts 35, 36, and 37 are arranged in the through hole 2A. The hour hand 31 is mounted on the pointer shaft 35, the minute hand 32 is mounted on the pointer shaft 36, and the second hand 33 is mounted on the pointer shaft 37. The hour hand 31, minute hand 32, and second hand 33 are set to lengths corresponding to the planar dimensions of the dial 2.

[0038] The pointer axes 35, 36, and 37, as well as the hour hand 31, minute hand 32, and second hand 33, are made of conductive metal components.

[0039] A rectangular date window 2B is located at the 3 o'clock position on dial 2. A date wheel 5 is located on the back side of dial 2, and can be seen from the date window 2B. The hour hand 31, minute hand 32, second hand 33, and date wheel 5 are driven by a stepper motor and gear train described later.

[0040] The dial ring 16, like the dial 2, is made of non-conductive components and is ring-shaped when viewed from above, and is arranged along the outer periphery of the dial 2. In this embodiment, the dial ring 16 is formed of polycarbonate resin with a relative permittivity of 3.

[0041] The mechanism 20 includes a base plate 21, a drive mechanism 23, a secondary battery 24, a solar panel 25, a planar antenna 50, a circuit board 70, a magnetically resistant plate 81, and a circuit pressure plate 82. Additionally, although in Figure 2 The illustration is omitted, but a date wheel 5 is arranged between the planar antenna 50 and the base plate 21. In addition, a wheel train clamping plate, which together with the base plate 21 supports the wheel train that constitutes the drive mechanism 23, is arranged between the base plate 21 and the circuit board 70.

[0042] The base plate 21 is made of synthetic resin, and its planar dimensions are constant, independent of the inner diameter of the housing 10. That is, the drive mechanism 23 is mounted on the back of the base plate 21. Therefore, the base plate 21 is sized to correspond to the drive mechanism 23, i.e., large enough to mount the drive mechanism 23. Thus, even if the inner diameter of the housing 10 increases, the planar dimensions of the base plate 21 remain constant. In the electronic clock 1, the outer diameter of the base plate 21 is smaller than the inner diameter of the housing 10. Therefore, an annular frame 28 is arranged in the gap between the base plate 21 and the inner surface of the housing 10.

[0043] The drive mechanism 23 is mounted on the back of the base plate 21 and drives the hour hand 31, minute hand 32, second hand 33, and date wheel 5. Specifically, the drive mechanism 23 has four stepper motors and four gear trains that drive the hour hand 31, minute hand 32, second hand 33, and date wheel 5 respectively. These stepper motors are positioned so as not to overlap with the secondary battery 24 when viewed from above.

[0044] The circuit board 70 has integrated circuit (IC), resistors, capacitors, and other circuit components mounted on both sides of the back of the watch. As ICs, it includes a receiving IC for processing signals received by the planar antenna 50, and a control IC for controlling the driving of the hour hand 31, minute hand 32, second hand 33, and date wheel 5. The circuit board 70 is positioned on the back side of the wheel train clamp and is formed to a size corresponding to the base plate 21, i.e., the size corresponding to the drive mechanism 23.

[0045] The secondary battery 24 is a button-type lithium-ion battery, which is disposed in the cutout of the circuit board 70.

[0046] Also Figure 3 As shown, the solar panel 25 is a solar cell panel for use in watches, such as a thin-film solar cell obtained by laminating an amorphous silicon thin film on a resin film substrate. The solar panel 25 has: a through hole 25A for inserting the pointer shafts 35-37; a date window 25B for visually viewing the date wheel 5; and two electrode terminals. These electrode terminals are connected to the circuit board 70 via two conductive members 251. Specifically, the conductive members 251 are composed of coil springs, and the current generated by the solar panel 25 is charged to the secondary battery 24 via the conductive members 251 and the circuit board 70.

[0047] [Planar Antenna]

[0048] The planar antenna 50 is an antenna for receiving satellite signals from GPS satellites, and in this embodiment it is composed of a plate-shaped inverted F-type antenna.

[0049] Also Figure 2 As shown, when viewed from the side in a direction parallel to the surface of the dial 2, the planar antenna 50 is positioned between the dial 2 and the base plate 21. The planar antenna 50 is configured to include: a dielectric 51; a plate-shaped radiating electrode 52; a plate-shaped grounding electrode 53 arranged to overlap with the radiating electrode 52 when viewed from above; and a shorting portion 54 that shorts the radiating electrode 52 and the grounding electrode 53.

[0050] A through hole 501 is formed at the center of the plane of the planar antenna 50 for the insertion of pointer shafts 35-37. That is, the through hole 501 is formed through the radiating electrode 52, the dielectric 51, and the ground electrode 53. In addition, a date window 503 for visually viewing the date wheel 5 is formed in the planar antenna 50 at a position that overlaps with the date windows 2B and 25B when viewed from above.

[0051] like Figure 3 as well as Figure 4 As shown, a recess 502 is formed on the outer peripheral surface of the planar antenna 50. A conductive member 251 is disposed in the recess 502. Furthermore, in Figure 4 In the diagram, each unit of the solar panel 25 is schematically represented by an eight-part sector. Additionally, in... Figure 4 The through hole 501 for the insertion of pointer shafts 35-37 is omitted.

[0052] The dielectric 51 is formed of dielectric materials such as polyphenylene sulfide, liquid crystal polymer, and polycarbonate, and is positioned between the radiation electrode 52 and the ground electrode 53 when viewed from the side.

[0053] The radiating electrode 52 is formed of a thin metal plate, such as a copper or iron alloy, and is connected to the circuit board 70 via a power supply pin 56, which serves as a power supply component. Furthermore, in Figure 2 The diagram schematically illustrates that the power supply pin 56 passes through the ground electrode 53 and the dielectric 51 and contacts the radiation electrode 52, but in reality, as shown... Figure 3 As shown, the configuration is such that the power supply terminal of the radiation electrode 52 extends to the lower surface via the side of the dielectric 51, and the upper end of the power supply pin 56 contacts the power supply terminal.

[0054] The lower end of the power supply pin 56 abuts against the circuit board 70 and is connected to the receiving IC mounted on the circuit board 70. Therefore, when viewed from above, the power supply pin 56 is arranged overlapping the base plate 21 and the circuit board 70.

[0055] like Figure 4 As shown, when viewed from above, the radiation electrode 52 is formed such that at least a portion protrudes outward from the base plate 21. That is, when viewed from above, a portion of the radiation electrode 52 with the recess 502 is positioned closer to the inner side of the outer periphery of the base plate 21, but the remaining portion protrudes outward from the outer periphery of the base plate 21. Therefore, the radiation electrode 52 has a portion that protrudes outward from the base plate 21 when viewed from above.

[0056] Specifically, when using the scale positions of the dial 2 to indicate the circumferential position of the outer periphery of the radiation electrode 52, the outer periphery 521, extending clockwise from approximately 11 o'clock to approximately 2 o'clock, is positioned closer to the inner side of the outer periphery of the base plate 21. That is, the dimension from the central axis of the pointer axes 35-37 to the outer periphery 521 is set to be smaller than the dimension from the central axis of the pointer axes 35-37 to the outer periphery of the base plate 21.

[0057] On the other hand, the outer periphery 522, extending clockwise from approximately the 2 o'clock position of the radiation electrode 52 to approximately the 11 o'clock position, protrudes outward from the outer periphery of the base plate 21, i.e., towards the housing 10. That is, the dimension of the outer periphery 522 from the central axis of the pointer axes 35-37 is set larger than the dimension from the central axis of the pointer axes 35-37 to the outer periphery of the base plate 21. Therefore, when viewed from above, the middle frame 28, located on the outer side of the base plate 21, overlaps with the radiation electrode 52.

[0058] Also Figure 2 As shown, the dielectric 51 and ground electrode 53 of the planar antenna 50 are formed to be smaller than the substrate 21. Therefore, the outer periphery of the dielectric 51 and ground electrode 53 is positioned further inward than the outer periphery of the substrate 21.

[0059] Therefore, when viewed from above, the area of ​​the radiating electrode 52 is set to be larger than that of the dielectric 51 and the grounding electrode 53, and is also set to be larger than that of the solar panel 25.

[0060] The grounding electrode 53 is formed of a thin metal plate, such as copper or iron alloy, and is conductive to the grounding terminal of the circuit board 70. Furthermore, the grounding electrode 53 is formed to almost cover the surface of the base plate 21, thus also serving as a non-magnetic plate covering the side of the stepper motor near the dial 2. Additionally, the radiating electrode 52, as described above, is a metal plate, and therefore also serves as a support substrate for the film-coated solar panel 25.

[0061] The shorting portion 54 is formed by a metal coating, such as electroplating, on the side of a thin metal plate or dielectric 51, and is conductive to the radiation electrode 52 and the ground electrode 53. The shorting portion 54 is provided at least in the recess 502, and in this embodiment, it is also provided in the outer peripheral portion 521. Therefore, the conductive member 251 is disposed on the outer peripheral side of the shorting portion 54. Furthermore, the outer peripheral portion 522 of the radiation electrode 52 that protrudes outward from the base plate 21 is the portion other than the portion where the shorting portion 54 is provided.

[0062] [Reference Example]

[0063] For comparison with the electronic clock 1 of this embodiment, refer to Figure 5 and Figure 6 The electronic clock 1D, whose housing 10 is smaller than that of the electronic clock 1, will be described. Furthermore, in the electronic clock 1D, structures identical or the same as those in the electronic clock 1 will be labeled with the same reference numerals, and descriptions will be omitted.

[0064] The planar dimensions of the housing 10D of the electronic clock 1D are smaller than those of the electronic clock 1. Specifically, the inner surface dimensions of the housing 10D are set to match the planar dimensions of the base plate 21, and the base plate 21 is disposed within the housing 10D without a middle frame 28. That is, the electronic clock 1D is the smallest clock that can accommodate the base plate 21.

[0065] Furthermore, the planar antenna 50D of the electronic clock 1D is configured to have a dielectric 51D, a radiating electrode 52D, a ground electrode 53D, and a shorting portion 54D. The dielectric 51D, ground electrode 53D, and shorting portion 54D have the same structure as the dielectric 51, ground electrode 53, and shorting portion 54 of the electronic clock 1.

[0066] The differences between electronic clock 1D and electronic clock 1 are as follows: corresponding to the size of the casing 10D, the planar dimension of the dial 2D is smaller than that of the dial 2 of electronic clock 1; corresponding to the dial 2D, the lengths of the hour hand 31, minute hand 32, and second hand 33 are shorter than those of the hour hand 31, minute hand 32, and second hand 33 of electronic clock 1; and the planar dimension of the radiating electrode 52D is smaller than that of the radiating electrode 52 of electronic clock 1. For example... Figure 6As shown, the planar dimension of the radiation electrode 52D is smaller than the planar dimension of the base plate 21, and the outer peripheral portion 521D of the radiation electrode 52D is arranged around the entire circumference at a position closer to the inner side than the outer peripheral surface of the base plate 21.

[0067] In electronic clock 1D, the other structures are the same as in electronic clock 1, so descriptions are omitted. Furthermore, the configuration positions of the conducting component 251 and the power supply pin 56 when viewed from above are the same in electronic clocks 1 and 1D. The planar dimensions of the date wheel 5 are limited to dimensions that do not interfere with the conducting component 251 and the power supply pin 56. Therefore, the size of the date wheel 5 and the formation positions of the date windows 2B, 25B, and 503 are the same in electronic clocks 1 and 1D.

[0068] [Improvement in antenna gain]

[0069] Figure 7 This is a graph showing the improvement in antenna gain when the antenna diameter of the planar antenna 50 is increased, specifically the diameter of the radiating electrode 52 is increased. Figure 7 The diagram shows the gain variation when the inner diameter of the housing 10 is set to 33 mm, with the antenna gain (0 dB) as a reference when the antenna diameter of the planar antenna 50 is 28 mm, and the antenna diameter is increased. Figure 7 As shown, increasing the antenna diameter by 1–3 mm improved the antenna gain by approximately 0.5 dB. However, further increasing the antenna diameter reduced the antenna gain, especially when the difference between the inner diameter of the housing 10 and the antenna diameter was less than 1 mm, resulting in a lower antenna gain compared to the case with an antenna diameter of 28 mm. This is because the planar antenna 50 is too close to the metal housing 10, leading to a decrease in receiving sensitivity.

[0070] Therefore, it can be confirmed that by appropriately increasing the size of the planar antenna 50 in accordance with the inner diameter of the housing 10, the receiving sensitivity is improved.

[0071] [Effects of the First Embodiment]

[0072] According to this embodiment, in the electronic clock 1 with a large-scale housing 10, the movement 20, except for the dial 2 and the radiating electrode 52, is interchangeable with the electronic clock 1D with a small-scale housing 10D. Therefore, the manufacturing cost of electronic clocks 1 and 1D with different housing sizes can be reduced. That is, in electronic clocks 1 and 1D, the base plate 21, drive mechanism 23, circuit board 70, etc., can be interchangeable. When the base plate 21 is assembled into a larger-scale housing 10, only the dial 2, radiating electrode 52, and middle frame 28 corresponding to the housing size need to be selected. Therefore, in the case of electronic clocks 1 and 1D with different sizes of dials 2 and 2D and housings 10 and 10D, the interchangeable movement 20 can be used, and the increase in cost can be prevented.

[0073] In the electronic clock 1, the receiving sensitivity of the planar antenna 50 can be improved by increasing the planar size of the radiating electrode 52 of the planar antenna 50 in proportion to the size of the housing 10.

[0074] In the planar antenna 50 of the electronic clock 1, only the size of the radiating electrode 52 is increased. The dielectric 51 and the grounding electrode 53 are the same as those of the planar antenna 50D of the electronic clock 1D. Therefore, the cost increase of the planar antenna 50 can be minimized and the receiving sensitivity can be improved.

[0075] In the radiating electrode 52, the recess 502 with the shorting portion 54 and the outer peripheral portion 521 are not enlarged, but the outer peripheral portion 522, except for the shorting portion 54, is enlarged outward. Therefore, the placement positions of the power supply pin 56 and the conducting member 251 can be common in the planar antennas 50 and 50D. Thus, the same circuit board 70, including the terminal positions contacted by the power supply pin 56 and the conducting member 251, can be used without changing the circuit board 70 according to the housing size, thereby reducing costs.

[0076] Furthermore, since the conductive member 251 is disposed on the outside of the recess 502 where the shorting portion 54 is formed, the influence of the conductive member 251, which is made of a coil spring, on the receiving sensitivity can be reduced.

[0077] [Second Implementation]

[0078] Next, refer to Figure 8 as well as Figure 9 The electronic clock 1B according to the second embodiment will be described.

[0079] The structure of the planar antenna 50B of the electronic clock 1B differs from that of the electronic clock 1 in the first embodiment, but the rest of the structure is the same. Therefore, the same reference numerals are used for the structures common to the electronic clock 1 in the first embodiment, and the description is omitted.

[0080] like Figure 8 as well as Figure 9 As shown, the planar antenna 50B of the electronic clock 1B has a radiating electrode 52B, a dielectric 51B, a grounding electrode 53B, and a shorting part 54B.

[0081] The dielectric 51B also serves as a date wheel plate for holding the date wheel (not shown). The radiating electrode 52B is composed of a metal coating formed on the front side of the dielectric 51B. Furthermore, the shorting portion 54B is composed of metal coatings formed on the side and back sides of the dielectric 51B. The metal coating can be formed, for example, by plating with copper, silver, nickel, aluminum, etc.

[0082] Therefore, when viewed from above, the dielectric 51B and the radiating electrode 52B are the same size, and thus, in this embodiment, they are formed to have a planar size larger than that of the solar panel 25. Furthermore, the dielectric 51B and the radiating electrode 52B each have: an outer peripheral portion 521B whose outer peripheral surface is inward of the outer peripheral surface of the base plate 21; and an outer peripheral portion 522B whose outer peripheral surface is outward of the base plate 21. By providing this outer peripheral portion 522B, the area of ​​the radiating electrode 52B is larger than the area of ​​the radiating electrode 52D of the planar antenna 50D.

[0083] The ground electrode 53B is made of a metal plate and is formed with a planar dimension larger than that of the dielectric 51B and the radiating electrode 52B. Therefore, in addition to the radiating electrode 52B, at least a portion of the dielectric 51B and the ground electrode 53B of the planar antenna 50B also protrude outwards from the base plate 21 when viewed from above. That is, the radiating electrode 52B, dielectric 51B, and ground electrode 53B of the planar antenna 50B each have a portion that protrudes outwards from the base plate 21 when viewed from above.

[0084] In addition, the grounding electrode 53B is formed to roughly cover the side of the drive mechanism 23 near the dial 2, and thus also functions as a non-magnetic plate.

[0085] The shorting portion 54B is connected to the radiating electrode 52B, and further connected to the grounding electrode 53B through contact with it. The shorting portion 54B is formed in the outer peripheral portion 521B and the recessed portion 502.

[0086] Therefore, in the radiating electrode 52B and the dielectric 51B, the outer peripheral portion 522B that protrudes outward from the base plate 21 is the portion other than the outer peripheral portion 521B where the shorting portion 54B is provided. On the other hand, the grounding electrode 53B protrudes outward from the base plate 21, except for the recess 502 where the conductive member 251 is provided. These portions that protrude outward from the base plate 21 overlap with the middle frame 28 when viewed from above.

[0087] The radiating electrode 52B is connected to the circuit board 70 via power supply pin 56. Furthermore, in Figure 8The schematic diagram illustrates the conductive structure between the power supply pin 56 and the radiating electrode 52B. However, in the planar antenna 50B, a metal coating is formed extending from the radiating electrode 52B through the side of the dielectric 51B to the back surface to constitute a power supply terminal. This allows the power supply pin 56 to abut against the power supply terminal located on the back surface of the dielectric 51B, thus achieving conductivity. The planar arrangement of the power supply pin 56 and the conductive member 251, i.e., the arrangement of the power supply pin 56 and the conductive member 251 relative to the central axis of the pointer axes 35-37 when viewed from above, is the same as that of the electronic clocks 1 and 1D. Therefore, the electronic clock 1B also uses the same date wheel 5 and circuit board 70 as the electronic clocks 1 and 1D. Furthermore, the conductive member 251, located in the recess 502, is positioned outside the shorting portion 54B.

[0088] [Effects of the Second Implementation]

[0089] In the electronic clock 1B of the second embodiment, the areas of the dielectric 51B and the radiating electrode 52B of the planar antenna 50B are made larger than the area of ​​the planar antenna 50D, and the grounding electrode 53B is formed to be greater than or equal to the radiating electrode 52B, thereby further improving the receiving sensitivity of the planar antenna 50B.

[0090] Since the base plate 21, drive mechanism 23, secondary battery 24, solar panel 25, middle frame 28, power supply pin 56, circuit board 70, magnetic plate 81, circuit pressure plate 82, and conductive component 251 are common to the electronic clock 1 or electronic clock 1D of the first embodiment, the cost can be reduced. That is, it is possible to manufacture electronic clocks 1, 1B, and 1D with different housing sizes and antenna performances while preventing the cost from increasing.

[0091] [Third Implementation Method]

[0092] Next, refer to Figure 10 as well as Figure 11 The electronic clock 1C according to the third embodiment will be described.

[0093] The structure of the planar antenna 50C, solar panel 25C, conductive component 252, base plate 21C, and dial ring 16C of the electronic clock 1C differs from that of the electronic clock 1, but the other structures are the same. Therefore, the same reference numerals are used for the structures common to the electronic clock 1 of the first embodiment, and descriptions are omitted.

[0094] The planar antenna 50C of the electronic clock 1C has a dielectric 51C, a radiating electrode 52C, a grounding electrode 53C, and a shorting part 54C.

[0095] The dielectric 51C also serves as a date wheel holder for holding the date wheel (not shown in the diagram). The radiating electrode 52C is composed of a metal coating formed on the front side of the dielectric 51C, the grounding electrode 53C is composed of a metal coating formed on the back side of the dielectric 51C, and the shorting portion 54C is composed of a metal coating formed on the side of the dielectric 51C. The metal coating can be formed, for example, by plating with copper, silver, nickel, aluminum, etc. Therefore, when viewed from above, the dielectric 51C, the radiating electrode 52C, and the grounding electrode 53C are the same size.

[0096] Furthermore, the base plate 21C of the electronic clock 1C has: a first region 211 in which a drive mechanism 23 is mounted; and a second region 212 disposed on the outer periphery of the first region 211, formed to correspond to the difference between the inner diameter of the housing 10 and the planar dimension of the first region 211. The first region 211 is configured with the same planar dimension as the base plate 21 that can be assembled into the smallest size housing 10D. The width dimension of the second region 212, that is, the protrusion dimension from the first region 211 to the outer periphery of the second region 212, is set accordingly to the housing dimension. Therefore, the second region 212 of the base plate 21C abuts against the inner surface of the housing 10, and the base plate 21C can be directly housed inside the housing 10 without a middle frame. It should be noted that the second region 212 may abut against the inner surface of the housing 10 throughout its entire circumference, or it may abut against the inner surface of the housing 10 at multiple locations.

[0097] The solar panel 25C is formed to have an area larger than that of the solar panel 25 of the electronic clocks 1 and 1B. Furthermore, the power generation layer of the solar panel 25C is configured to have an area smaller than the radiating electrode 52C of the planar antenna 50C, thus expanding the portion of the solar panel 25 where the power generation layer is not located. Additionally, the dial ring 16C is formed to cover the dial 2 and the solar panel 25C, and its area is smaller than that of the dial ring 16.

[0098] The conductive component 252 is configured to include: a first helical spring 252A that contacts a terminal of the solar panel 25C; a second helical spring 252B that contacts a terminal of the circuit board 70; and a connecting portion 252C that connects the first helical spring 252A and the second helical spring 252B. The second helical spring 252B is disposed in a first region 211 of the base plate 21C, and the first helical spring 252A and the connecting portion 252C are disposed in a second region 212 of the base plate 21C. Additionally, the first helical spring 252A is disposed outside the shorting portion 54C.

[0099] Because the first helical spring 252A of the conducting component 252 is positioned further outward than the second helical spring 252B, the diameter of the date wheel 5 can be increased compared to electronic clocks 1 and 1B, allowing the date window 503 to be positioned further outward. At this time, only the width of the date wheel 5 is increased; the positions of the inner teeth and the date-changing wheel of the date wheel 5 are the same as in electronic clocks 1 and 1B.

[0100] Furthermore, by placing the first helical spring 252A on the outside, it is unnecessary to form a recess in the planar antenna 50C for arranging the conductive member 252. Therefore, the outer periphery of the planar antenna 50C extends all the way to a position overlapping with the second region 212 of the base plate 21C.

[0101] [Effects of the Third Implementation]

[0102] The electronic clock 1C of the third embodiment not only increases the area of ​​the planar antenna 50C, but also increases the area of ​​the solar panel 25C, thus improving the receiving sensitivity and power generation capacity.

[0103] Furthermore, since the drive mechanism 23, secondary battery 24, power supply pin 56, circuit board 70, magnetic plate 81, and circuit pressure plate 82 are interchangeable with electronic clocks 1, 1B, and 1D, costs can be reduced. Additionally, the holding shape of the drive mechanism 23 in the first region 211 of the base plate 21C can be made interchangeable with electronic clocks 1, 1B, and 1D; only the second region 212 and the housing size need to be changed accordingly. That is, electronic clocks 1, 1B, 1C, and 1D with different housing sizes or antenna performance can be manufactured without increasing costs.

[0104] Because the first helical spring 252A of the guiding component 252 is positioned further outward than the second helical spring 252B, the diameter of the date wheel 5 can be increased, thereby further expanding the date window 503 outwards. In this case, since only the width of the date wheel 5 is increased, it is not necessary to change the position of the inner teeth of the date wheel 5 or the date changing wheel, thus suppressing the increase in cost.

[0105] The first helical spring 252A is disposed on the outer periphery of the solar panel 25C, so the dial ring 16C can cover the connection portion where the first helical spring 252A connects to the solar panel 25C. Therefore, the appearance of the electronic clock 1C can be improved.

[0106] [Other Implementation Methods]

[0107] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be implemented within the scope of the spirit of the present invention.

[0108] For example, the shape of the planar antenna is not limited to an antenna that appears roughly circular when viewed from above; it can also be quadrilateral or Reynolds-shaped when viewed from above. For example, in an electronic clock that uses a quadrilateral or Reynolds-shaped housing, the shapes of the dial, solar panel, and planar antenna are formed to correspond to the shape of the housing and are quadrilateral or Reynolds-shaped. Other structures such as the base plate 21 or the drive mechanism 23 can be interchanged with the electronic clocks 1, 1B, and 1C described in the various embodiments. In addition, a mid-frame can be used to fit the circular base plate 21 into a quadrilateral or similar housing.

[0109] Planar antennas 50, 50B, and 50C are not limited to planar inverted-F antennas that resonate at 1 / 4 wavelength of the received signal; other antennas, such as thin patch antennas that resonate at 1 / 2 wavelength of the received signal, can also be used.

[0110] The dielectrics 51, 51B, and 51C of the planar antennas 50, 50B, and 50C are not limited to serving as date wheel pressure plates; they can also have the function of holding other clock components, or they can be set up specifically for antennas.

[0111] The planar antennas 50 and 50B have their outer peripheral portions 522 and 522B, excluding the shorting portions 54 and 54B, protruding outward from the base plate 21. However, the portions other than the recess 502, i.e., the portions of the shorting portions 54 and 54B other than those opposite to the conducting members 251 and 252, can also protrude outward from the base plate 21.

[0112] The solar panel 25 of electronic clocks 1 and 1B is the same size as the solar panel 25 of electronic clock 1D, which has a smaller housing size. However, a larger solar panel can be used to correspond to an increase in housing size. In this case, the area of ​​the power generation layer of the solar panel 25 is smaller than the area of ​​the radiating electrodes 52 and 52B of the planar antenna 50, so the portion where the power generation layer is not provided can be enlarged. In this case, since the arrangement position of the conducting member 251 does not change, the solar panel is not enlarged in the area overlapping with the outer peripheral portions 521 and 521B of the recess 502 where the shorting portions 54 and 54B are provided. Instead, the area is increased by enlarging the outer peripheral side of the solar panel in the area overlapping with the outer peripheral portions 522 and 522B.

[0113] The electronic clocks 1, 1B, and 1C described above are clocks with three hands: an hour hand 31, a minute hand 32, and a second hand 33. However, the shapes and through holes for accommodating other motors, gear trains, and pointer shafts can also be pre-set on the base plates 21 and 21C, and the planar antennas 50, 50B, and 50C. With this configuration, the presence or absence of a sub-dial and its position can be easily changed by adding corresponding motors or gear trains or altering the dial. Therefore, in addition to changing the size of the casing, it is also possible to easily derive electronic clocks such as adding a display section.

[0114] Furthermore, the material of the case 10 is not limited to metal. For example, the case body 11 with the case 12 and bezel 13, and the back cover 14 can also be made of ceramic or synthetic resin.

[0115] Electronic clocks may also forgo solar panels 25 and 25C, instead using a primary battery instead of a secondary battery 24. In this case, conductive components 251 and 252 are unnecessary, and they do not affect the receiving sensitivity of planar antennas 50, 50B, and 50C. Therefore, the configuration of shorting sections 54, 54B, and 54C can be changed.

[0116] The shorting sections 54, 54B, and 54C are provided to adjust the receiving characteristics of the planar antennas 50, 50B, and 50C. Therefore, if the signal can be received even without the shorting sections 54, 54B, and 54C, the shorting sections may not be required.

[0117] In the above embodiments, the antenna receives satellite signals transmitted from GPS satellites, but the signals received by the antenna are not limited to this. For example, it can also receive satellite signals transmitted from other Global Navigation Satellite Systems (GNSS) such as Galileo, GLONASS, and Beidou, Geostationary Satellite Navigation Augmentation Systems (SBAS), Quasi-Zenith Satellite Systems (RNSS) and other Regional Satellite Positioning Systems that can only be retrieved in specific regions.

[0118] Antennas are not limited to receiving satellite signals; they can also be antennas that receive other radio waves such as Bluetooth (registered trademark), BLE (Bluetooth Low Energy), Wi-Fi (registered trademark), NFC (Near Field Communication), and LPWA (Low Power Wide Area). In other words, the antennas assembled into electronic clocks 1, 1B, and 1C only need to be appropriate based on the type of signal received, the size of the clock, and its compatibility with other components.

[0119] [Summary of this disclosure]

[0120] The electronic clock disclosed herein is characterized by having: a housing; hands; a dial; a drive mechanism that drives the hands; a base plate on which the drive mechanism is mounted; an antenna disposed between the dial and the base plate when viewed from the side in a direction parallel to the surface of the dial; and a circuit board, the antenna having: a plate-shaped radiating electrode; a plate-shaped ground electrode; and a dielectric disposed between the radiating electrode and the ground electrode when viewed from the side, the circuit board being connected to the radiating electrode via a power supply component, the radiating electrode having a portion that protrudes outward from the base plate when viewed from a direction perpendicular to the surface of the dial.

[0121] According to the electronic clock disclosed herein, when viewed from the side, the antenna is positioned between the dial and the base plate, thus increasing the antenna area. Furthermore, since the radiating electrode has a portion that protrudes outwards from the base plate when viewed from above, the area of ​​the radiating electrode can be further increased. Therefore, the radiating electrode can be increased in size corresponding to the housing dimensions, thereby improving the antenna's receiving sensitivity.

[0122] In the electronic clocks of this disclosure, preferably, the grounding electrode and the dielectric have portions that protrude outward from the base plate when viewed from above.

[0123] In addition to the radiating electrodes, the area of ​​the grounding electrodes and dielectric can be increased, thus further improving the antenna's receiving sensitivity.

[0124] In the electronic clock of this disclosure, preferably, the electronic clock has: a solar panel; and a conductive member that connects the solar panel to the circuit board, the antenna having a shorting portion that shorts the radiating electrode to the ground electrode, the conductive member and the shorting portion overlapping the base plate when viewed from above, and the conductive member being disposed outside the shorting portion when viewed from above.

[0125] By providing a shorting section that connects the radiating electrode and the ground electrode, the antenna characteristics can be easily adjusted. Furthermore, since the conducting member is positioned where it overlaps with the base plate when viewed from above, it can conduct to the circuit board at the overlapping position, thus enabling the circuit board to be universally compatible.

[0126] Furthermore, since the conductive component is positioned on the outside of the shorting portion, the impact of the conductive component, such as the helical spring, on the antenna's receiving sensitivity can be reduced.

[0127] In the electronic clocks disclosed herein, preferably, the antenna has a shorting portion that short-circuits the radiating electrode to the ground electrode, and the portion of the radiating electrode that protrudes outward from the base plate is the portion other than the shorting portion.

[0128] In the antenna's radiating electrodes, the portion protruding outward from the base plate is defined as the part other than the shorting section. This allows for a large protruding area outside the shorting section, effectively increasing the area of ​​the radiating electrodes and improving the antenna's receiving sensitivity. Furthermore, since the shorting section does not protrude outward from the base plate, when a connecting component is placed outside the shorting section, its placement can be fixed, and the circuit board and other components can be standardized.

[0129] In the electronic clocks of this disclosure, preferably, the portion of the radiating electrode that protrudes outward from the base plate is the portion other than the portion of the shorting portion opposite the conducting member.

[0130] In the antenna's radiating electrode, the portion protruding outward from the base plate is defined as the portion other than the part of the shorting section opposite the conducting component. This allows for a large protruding area, including not only the portion excluding the shorting section but also the portion of the shorting section not opposite the conducting component, effectively increasing the area of ​​the radiating electrode and improving the antenna's receiving sensitivity. Furthermore, since the portion of the shorting section opposite the conducting component does not protrude outward from the base plate, the placement of connecting components can be fixed, and the circuit board and other components can be standardized.

[0131] In the electronic clocks disclosed herein, it is preferred that the electronic clock has a middle frame disposed between the housing and the base plate, and that the middle frame overlaps with the radiating electrode when viewed from above.

[0132] By using a mid-frame that matches the housing size, a universal base plate can be installed in housings of various sizes. Furthermore, since the radiating electrodes can be extended to the mid-frame, their size can be increased accordingly to match the housing dimensions, thereby improving receiving performance.

[0133] In the electronic clocks disclosed herein, it is preferred that the circuit board is formed to a size corresponding to the drive mechanism, and that, in the top view, the power supply component overlaps with the base plate and the circuit board.

[0134] The circuit board is sized to correspond to the drive mechanism, so it can be set to the same minimum size as the base plate. Therefore, a common circuit board can be used with the base plate and drive mechanism for various housings of different sizes, preventing increased costs.

[0135] Furthermore, since the power supply component that connects the antenna to the circuit board overlaps with the base plate and the circuit board when viewed from above, the placement of the power supply component can be fixed regardless of the size of the housing, which also enables the circuit board to be universalized.

[0136] The electronic clock disclosed herein is characterized by having: a housing; hands; a dial; a drive mechanism that drives the hands; a base plate on which the drive mechanism is mounted; an antenna disposed between the dial and the base plate when viewed from the side in a direction parallel to the surface of the dial; and a circuit board, the base plate having: a first region on which the drive mechanism is mounted; and a second region disposed on the outer periphery of the first region and abutting against the housing; the antenna having: a plate-shaped radiating electrode; a plate-shaped grounding electrode; and a dielectric disposed between the radiating electrode and the grounding electrode when viewed from the side; the circuit board being connected to the radiating electrode via a power supply component; the dial being formed to a size corresponding to the housing; and the radiating electrode having a portion overlapping the second region when viewed from a direction perpendicular to the surface of the dial.

[0137] According to the electronic clock disclosed herein, the base plate has a first region on which a drive mechanism is mounted and a second region that abuts against the housing. Therefore, for various housings of different sizes, a base plate of different sizes in the second region and a dial of a size corresponding to the housing can be used. Other components such as the drive mechanism can be universalized, thus preventing an increase in cost.

[0138] Furthermore, when viewed from the side, the antenna is positioned between the dial and the base plate, thus increasing the antenna area. Moreover, since the radiating electrode has a portion that overlaps with a second area of ​​the base plate when viewed from above, the area of ​​the radiating electrode can be further increased. Therefore, the radiating electrode can be increased in proportion to the housing size, thereby improving the antenna's receiving sensitivity.

Claims

1. An electronic timepiece characterized by comprising: a case of metal; a hand; a dial; and a movement including a driving mechanism that drives the hand, a base plate on which the driving mechanism is mounted, the base plate holding the driving mechanism, an antenna that is a plate-shaped inverted-F antenna, the antenna being disposed between the dial and the base plate when viewed from a direction parallel to a surface of the dial, a circuit board, a solar panel, and a conduction member that conduction the solar panel and the circuit board, the antenna having: a plate-shaped radiating electrode; a plate-shaped ground electrode; a dielectric disposed between the radiating electrode and the ground electrode when viewed from the direction parallel to the surface of the dial; and a shorting portion that shorts the radiating electrode and the ground electrode, the circuit board being conduction the radiating electrode via a power supply member, the radiating electrode having a portion that protrudes outward of the base plate when viewed from a direction perpendicular to the surface of the dial, a recess is formed in an outer peripheral surface of the radiating electrode, the shorting portion being provided at least in the recess, the conduction member is disposed in the recess, a diameter of the radiating electrode is enlarged corresponding to an inner diameter of the case so that a difference between the inner diameter of the case and the diameter of the radiating electrode is 2 mm to 4 mm, when viewed from the direction perpendicular to the surface of the dial, a portion of the radiating electrode in which the recess is provided is disposed inward of an outer periphery of the base plate, and the other portion of the radiating electrode is formed to protrude outward of the outer periphery of the base plate, an outer periphery of the dielectric and the ground electrode is disposed inward of the outer periphery of the base plate.

2. The electronic timepiece according to claim 1, characterized in that: when viewed from the direction perpendicular to the surface of the dial, the conduction member and the shorting portion overlap the base plate, when viewed from the direction perpendicular to the surface of the dial, the conduction member is disposed outward of the shorting portion.

3. The electronic timepiece according to claim 2, characterized in that: the portion of the radiating electrode that protrudes outward of the base plate is a portion other than a portion of the shorting portion that opposes the conduction member.

4. The electronic timepiece according to claim 1 or 2, characterized in that: the electronic timepiece has a middle frame disposed between the case and the base plate, when viewed from the direction perpendicular to the surface of the dial, the middle frame overlaps the radiating electrode.

5. The electronic timepiece according to claim 1 or 2, characterized in that: the circuit board is formed to a size corresponding to the driving mechanism, when viewed from the direction perpendicular to the surface of the dial, the power supply member overlaps the base plate and the circuit board. ​ ​

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