Electronic clock

Abstract

To provide an electronic clock which, when composing an electronic clock differing in case size, enables prevention of increase in the cost thereof and furthermore enables improvement of the reception performance thereof.SOLUTION: The electronic clock comprises: a case; an indicator; a nameplate; a drive mechanism for driving the indicator; a bottom plate to which the drive mechanism is attached; an antenna which is located between the nameplate and the bottom plate in a lateral view when viewing from a direction parallel to the surface of the nameplate; and a circuit board. The antenna includes a tabular radiation electrode, a tabular ground electrode, and a dielectric substance which is located between the radiation electrode and the ground electrode in a lateral view. The circuit board is electrically conducted to the radiation electrode via a power feeding member, and the radiation electrode comprises a protrusion that protrudes to the outside of the bottom plate in a plan view when viewing from a direction orthogonal to the surface of the nameplate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electronic timepiece with a built-in antenna. [Background technology]

[0002] Among small electronic timepieces, such as wristwatches, there are known electronic timepieces that incorporate an antenna for receiving satellite signals. For example, Patent Document 1 discloses an electronic timepiece in which a flat antenna having a radiation conductor, a ground conductor, and a short circuit that connects these conductors is disposed between the dial and the base plate. Electronic timepieces with such an antenna incorporate have typically used dedicated movements for each case size. On the other hand, for electronic watches that do not have built-in antennas, it is known that multiple types of electronic watches with different case sizes can be constructed at low cost using a common movement and inner frames of different sizes, as disclosed in Patent Document 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-30056 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-114552 Summary of the Invention [Problem to be solved by the invention]

[0004] By using a movement with a flat antenna as in Patent Document 1 with an inner frame as disclosed in Patent Document 2, it is possible to create an electronic timepiece with a built-in antenna of a different case size. However, when a common movement is used, the antenna size is also common, which poses a problem in that it is not possible to improve reception performance. For this reason, when constructing electronic timepieces with built-in antennas with different case sizes, there is a demand for a structure that can improve reception performance while preventing increases in costs. [Means for solving the problem]

[0005] The electronic timepiece disclosed herein comprises a case, hands, a dial, a drive mechanism for driving the hands, a base plate to which the drive mechanism is attached, an antenna arranged between the dial and the base plate in a side view seen from a direction parallel to the surface of the dial, and a circuit board, wherein the antenna has a plate-shaped radiation electrode, a plate-shaped ground electrode, and a dielectric arranged between the radiation electrode and the ground electrode in the side view, the circuit board is electrically connected to the radiation electrode via a power supply member, and the radiation electrode has a portion that protrudes outward beyond the base plate in a plan view seen from a direction perpendicular to the surface of the dial.

[0006] The electronic timepiece disclosed herein comprises a case, hands, a dial, a drive mechanism that drives the hands, a base plate to which the drive mechanism is attached, an antenna that is arranged between the dial and the base plate in a side view seen from a direction parallel to the surface of the dial, and a circuit board, wherein the base plate has a first region to which the drive mechanism is attached and a second region that is provided on the outer periphery of the first region and abuts the case, the antenna has a plate-shaped radiating electrode, a plate-shaped ground electrode, and a dielectric that is arranged between the radiating electrode and the ground electrode in the side view, the circuit board is electrically connected to the radiating electrode via a power supply member, the dial is formed to a size that corresponds to the case, and the radiating electrode has a portion that overlaps the second region in a planar view seen from a direction perpendicular to the surface of the dial. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a front view showing an electronic timepiece according to a first embodiment. [Figure 2] FIG. 1 is a cross-sectional view of an electronic timepiece according to a first embodiment. [Figure 3]FIG. 2 is a perspective view showing the antenna, solar panel, and circuit board of the electronic timepiece according to the first embodiment. [Figure 4] FIG. 2 is a plan view showing the antenna and solar panel of the electronic timepiece according to the first embodiment. [Figure 5] FIG. 1 is a cross-sectional view of an electronic timepiece according to a reference example. [Figure 6] FIG. 10 is a plan view showing the antenna and solar panel of the electronic timepiece of the reference example. [Figure 7] 10 is a graph showing the relationship between antenna diameter and antenna gain. [Figure 8] FIG. 10 is a cross-sectional view of an electronic timepiece according to a second embodiment. [Figure 9] FIG. 10 is a plan view showing an antenna and a solar panel according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional view of an electronic timepiece according to a third embodiment. [Figure 11] FIG. 10 is a plan view showing an antenna and a solar panel according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] [First embodiment] The electronic timepiece 1 of the first embodiment will be described below with reference to the drawings. In this embodiment, the crystal 15 side of the electronic timepiece 1 will be described as the front side or upper side, and the case back 14 side will be described as the back side or lower side. Furthermore, a plan view means viewing the electronic timepiece 1 in a direction perpendicular to the surface of the dial 2, that is, from the axial direction of the pivot points 35 to 37 described below, and a side view means viewing the electronic timepiece 1 in a direction parallel to the surface of the dial 2.

[0009] The electronic watch 1 of this embodiment has a built-in planar antenna 50 (described later) and is configured to receive satellite signals from multiple positioning information satellites S, such as GPS satellites and quasi-zenith satellites, which orbit the Earth in a predetermined orbit, to obtain satellite time information and correct the internal time information.

[0010] As shown in Figures 1 and 2, the electronic timepiece 1 comprises a case 10 and a dial 2, hands 3, and a date wheel 5 housed within the case 10. The electronic timepiece 1 also comprises a crown 6 and two buttons 7 and 8 for external operation.

[0011] [Exterior structure of electronic watch] Case 10 comprises case main body 11 and back cover 14. Case main body 11 comprises a cylindrical case 12 and a ring-shaped bezel 13 attached to the front side of case 12. Note that in this embodiment, case 12 and back cover 14 are constructed as separate bodies, but this is not a limitation and a one-piece case in which case 12 and back cover 14 are integrated is also possible. Also, in this embodiment, case 12 and bezel 13 are constructed as separate bodies, but this is not a limitation and a structure in which case 12 and bezel 13 are integrated is also possible, which has the advantage of being less expensive. The case 12, bezel 13, and back cover 14 are made of a metallic material, such as stainless steel, titanium alloy, aluminum, or brass, that is, a conductive material.

[0012] A cover crystal 15 is attached to the bezel 13 via a plastic packing 17. The cover crystal 15 is made of a transparent material such as mineral glass, sapphire glass, or organic glass. The diameter of the cover crystal 15 is determined by the size of the case 10, and the thickness of the cover crystal 15 is determined by the relationship between the diameter and the waterproof performance.

[0013] [Internal structure of an electronic watch] Next, the internal structure of the case 10 of the electronic timepiece 1 will be described. As shown in FIG. 2, the case 10 accommodates the dial 2, the dial ring 16, the movement 20, and the like.

[0014] The dial 2 is formed into a disk shape from a non-conductive material. In this embodiment, the dial 2 is made of polycarbonate resin with a relative dielectric constant of 3. The dial 2 is formed to a size that corresponds to the case 10. In other words, the planar size of the dial 2, i.e., the diameter of the dial 2 in a planar view, is set according to the inner diameter of the case 10. In the electronic timepiece 1, the planar size of the dial 2 is larger than the planar size of the main plate 21, which will be described later, and overlaps with part of the center frame 28 in a planar view. As shown in Figure 2, the hands 3 include 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 coaxial hand stems 35, 36, and 37 are arranged in the through hole 2A. The hour hand 31 is attached to the stem 35, the minute hand 32 is attached to the stem 36, and the second hand 33 is attached to the stem 37. The hour hand 31, minute hand 32, and second hand 33 are set to lengths that correspond to the plane size of the dial 2. The hand shafts 35, 36, 37, the hour hand 31, the minute hand 32, and the second hand 33 are made of conductive metal members. A rectangular date window 2B is provided at the 3 o'clock position on the dial 2. A date wheel 5 is located on the back side of the dial 2 and can be seen through the date window 2B. The hour hand 31, minute hand 32, second hand 33, and date wheel 5 are driven via a step motor and gear train, which will be described later.

[0015] The dial ring 16 is made of a non-conductive material and has a ring shape in plan view, similar to the dial 2, and is arranged along the outer periphery of the dial 2. In this embodiment, the dial ring 16 is made of polycarbonate resin with a relative dielectric constant of 3.

[0016] The movement 20 includes a main plate 21, a drive mechanism 23, a secondary battery 24, a solar panel 25, a planar antenna 50, a circuit board 70, a magnetic shield 81, a circuit holder 82, etc. Although not shown in Fig. 2, a date wheel 5 is disposed between the planar antenna 50 and the main plate 21. Furthermore, a train wheel bridge is disposed between the main plate 21 and the circuit board 70, which supports the train wheels that make up the drive mechanism 23 together with the main plate 21.

[0017] The main plate 21 is made of synthetic resin, and its planar size is constant regardless of the inner diameter of the case 10. That is, the drive mechanism 23 is attached to the back surface of the main plate 21. For this reason, the main plate 21 is formed to a size that corresponds to the drive mechanism 23, that is, a size that allows the drive mechanism 23 to be attached. Therefore, the planar size of the main plate 21 can be kept constant even if the inner diameter of the case 10 increases. In the electronic timepiece 1, the outer diameter of the main plate 21 is smaller than the inner diameter of the case 10. For this reason, a ring-shaped inner frame 28 is disposed in the gap between the main plate 21 and the inner surface of the case 10. Drive mechanism 23 is attached to the back surface of main plate 21, and drives hour hand 31, minute hand 32, second hand 33, and date indicator 5. In other words, drive mechanism 23 has four step motors and four wheel trains that respectively drive hour hand 31, minute hand 32, second hand 33, and date indicator 5. These step motors are positioned so as not to overlap with secondary battery 24 in the plan view.

[0018] Circuit board 70 has circuit elements such as semiconductor integrated circuits (ICs), resistors, and capacitors mounted on both the front and back sides. The ICs provided include a receiving IC that processes signals received by planar antenna 50, and a control IC that controls the drive of hour hand 31, minute hand 32, second hand 33, and date indicator 5. Circuit board 70 is located on the back side of the train wheel bridge and is formed with a size that corresponds to the size of main plate 21, that is, the size that corresponds to the size of drive mechanism 23. The secondary battery 24 is a button-type lithium ion battery, and is disposed in a cutout portion of the circuit board 70.

[0019] As shown in Fig. 3, the solar panel 25 is a solar cell panel used in wristwatches, and can be, for example, a film-type solar cell in which an amorphous silicon thin film is laminated on a resin film substrate. The solar panel 25 is equipped with a through-hole 25A through which the hand shafts 35-37 are inserted, a date window 25B through which the date wheel 5 is visible, and two electrode terminals. These electrode terminals and the circuit board 70 are electrically connected by two conductive members 251. The conductive members 251 are specifically formed by coil springs, and the current generated by the solar panel 25 is charged into the secondary battery 24 via the conductive members 251 and the circuit board 70.

[0020] [Flat antenna] The planar antenna 50 is an antenna that receives satellite signals from GPS satellites, and in this embodiment is configured as a planar inverted-F antenna. 2, the planar antenna 50 is disposed between the dial 2 and the base plate 21 in a side view seen in a direction parallel to the surface of the dial 2. The planar antenna 50 is configured to include a dielectric 51, a plate-shaped radiation electrode 52, a plate-shaped ground electrode 53 arranged so as to overlap the radiation electrode 52 in a planar view, and a short-circuiting portion 54 that shorts the radiation electrode 52 and the ground electrode 53. A through-hole 501, through which the pointer shafts 35 to 37 are inserted, is formed in the planar center position of the planar antenna 50. That is, the through-hole 501 is formed by passing through the radiation electrode 52, the dielectric 51, and the ground electrode 53. Furthermore, in the planar antenna 50, a date window 503 for viewing the date wheel 5 is formed in a position that overlaps with the date windows 2B, 25B in a planar view. As shown in Figures 3 and 4, 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. In Figure 4, each cell of the solar panel 25 is shown as a fan shape divided into eight equal parts. In Figure 4, the through holes 501 through which the pointer shafts 35 to 37 are inserted are omitted.

[0021] The dielectric 51 is made of a dielectric material such as polyphenylene sulfide, liquid crystal polymer, or polycarbonate, and is disposed between the radiation electrode 52 and the ground electrode 53 when viewed from the side. The radiating electrode 52 is formed of a thin metal plate such as copper or an iron alloy, and is electrically connected to the circuit board 70 via a feed pin 56, which is a power feeding member. Note that in Fig. 2, the feed pin 56 is shown schematically as penetrating the ground electrode 53 and the dielectric 51 to contact the radiating electrode 52, but in reality, as shown in Fig. 3, the feed terminal of the radiating electrode 52 extends to the bottom surface via the side surface of the dielectric 51, and the upper end of the feed pin 56 contacts this feed terminal. The lower end of the power feed pin 56 abuts against the circuit board 70 and is electrically connected to a receiving IC mounted on the circuit board 70. Therefore, the power feed pin 56 is disposed so as to overlap the base plate 21 and the circuit board 70 in a plan view.

[0022] 4, the radiation electrode 52 is formed so that at least a portion thereof protrudes outward from the ground plate 21 in a plan view. That is, a portion of the radiation electrode 52 where the recess 502 is provided is disposed inside the outer periphery of the ground plate 21 in a plan view, while the other portion is formed so as to protrude outward from the outer periphery of the ground plate 21. Therefore, the radiation electrode 52 has a portion that protrudes outward from the ground plate 21 in a plan view. Specifically, when the circumferential position of the outer periphery of radiation electrode 52 is expressed in terms of the scale positions of dial 2, outer periphery 521, which extends from approximately 11 o'clock to approximately 2 o'clock in the clockwise direction of radiation electrode 52, is positioned inside the outer periphery of main plate 21. In other words, the dimension from the central axes of pivots 35 to 37 to outer periphery 521 is set smaller than the dimension from the central axes of pivots 35 to 37 to the outer periphery of main plate 21. On the other hand, an outer periphery 522 of the radiating electrode 52, which extends from approximately the 2 o'clock position to approximately the 11 o'clock position in the clockwise direction, protrudes outward from the outer periphery of the main plate 21, that is, toward the case 10. In other words, the dimension from the central axes of the pivots 35 to 37 to the outer periphery 522 is set to be larger than the dimension from the central axes of the pivots 35 to 37 to the outer periphery of the main plate 21. For this reason, the inner frame 28, which is arranged on the outside of the main plate 21, overlaps with the radiating electrode 52 in a plan view.

[0023] 2, the dielectric 51 and the ground electrode 53 of the planar antenna 50 are formed to be smaller than the ground plate 21. Therefore, the outer peripheries of the dielectric 51 and the ground electrode 53 are arranged inside the outer periphery of the ground plate 21. Therefore, the area of ​​the radiation electrode 52 is set to be larger than the area of ​​the dielectric 51 and the area of ​​the ground electrode 53 in a plan view, and is also set to be larger than the area of ​​the solar panel 25.

[0024] The ground electrode 53 is formed from a thin metal plate such as copper or an iron alloy, and is electrically connected to the ground terminal of the circuit board 70. The ground electrode 53 is sized to cover almost the entire surface of the main plate 21, and therefore also serves as a magnetic shield that covers the dial 2 side of the step motor. As the radiating electrode 52 is a metal plate as described above, it also serves as a support substrate that supports the film solar panel 25. The short-circuiting portion 54 is formed of a thin metal plate or a metal coating formed by plating or the like on the side surface of the dielectric 51, and is electrically connected to the radiation electrode 52 and the ground electrode 53. The short-circuiting portion 54 is provided at least in the recess 502, and in this embodiment, is also provided in the outer periphery 521. Therefore, the conductive member 251 is disposed on the outer periphery side of the short-circuiting portion 54. In addition, the outer periphery 522 of the radiation electrode 52, which protrudes outward beyond the ground plate 21, is not the portion where the short-circuiting portion 54 is provided.

[0025] [Reference example] For comparison with the electronic watch 1 of this embodiment, an electronic watch 1D having a case 10 smaller in size than the electronic watch 1 will be described with reference to Figures 5 and 6. Note that in the electronic watch 1D, components that are the same as or similar to those in the electronic watch 1 are given the same reference numerals and descriptions thereof will be omitted. The planar size of the case 10D of the electronic timepiece 1D is smaller than that of the electronic timepiece 1. Specifically, the size of the inner surface of the case 10D is set to match the planar size of the main plate 21, and the main plate 21 is placed inside the case 10D without an inner frame 28. In other words, the electronic timepiece 1D is the smallest size timepiece that can accommodate the main plate 21. The planar antenna 50D of the electronic timepiece 1D is configured with a dielectric 51D, a radiation electrode 52D, a ground electrode 53D, and a short-circuiting section 54D. The dielectric 51D, ground electrode 53D, and short-circuiting section 54D have the same configuration as the dielectric 51, ground electrode 53, and short-circuiting section 54 of the electronic timepiece 1. The electronic timepiece 1D differs from the electronic timepiece 1 in that the planar size of the dial 2D is smaller than the dial 2 of the electronic timepiece 1 in accordance with the size of the case 10D, that the lengths of the hour hand 31, minute hand 32, and second hand 33 are shorter than those of the electronic timepiece 1 in accordance with the dial 2D, and that the planar size of the radiating electrode 52D is smaller than the radiating electrode 52 of the electronic timepiece 1. As shown in Figure 6, the planar size of the radiating electrode 52D is smaller than that of the base plate 21, and the outer periphery 521D of the radiating electrode 52D is positioned inside the outer periphery of the base plate 21 along its entire circumference.

[0026] The rest of the configuration of the electronic timepiece 1D is the same as that of the electronic timepiece 1, so explanation will be omitted. Furthermore, the positions of the conductive member 251 and power supply pin 56 in a plan view are the same in both the electronic timepieces 1 and 1D. The planar size of the date wheel 5 is restricted to a size that does not interfere with the conductive member 251 or power supply pin 56. For this reason, the size of the date wheel 5 and the positions of the date windows 2B, 25B, and 503 are the same in both the electronic timepieces 1 and 1D.

[0027] [Antenna gain improvement effect] FIG. 7 is a graph showing the improvement in antenna gain when the antenna diameter of the planar antenna 50, specifically the diameter of the radiation electrode 52, is increased. FIG. 7 shows the gain variation when the antenna diameter is increased, with the antenna gain when the inner diameter of the case 10 is set to 33 mm and the antenna diameter of the planar antenna 50 is 28 mm set as the reference (0 dB). As shown in FIG. 7, when the antenna diameter is increased by 1 to 3 mm, the antenna gain improves by about 0.5 dB. However, when the antenna diameter is further increased, the antenna gain decreases. In particular, when the difference between the inner diameter of the case 10 and the antenna diameter is 1 mm or less, the antenna gain decreases compared to when the antenna diameter is 28 mm. This is because the planar antenna 50 is too close to the metal case 10, reducing reception sensitivity. Therefore, it was confirmed that the reception sensitivity can be improved by appropriately enlarging the size of the planar antenna 50 in accordance with the inner diameter of the case 10.

[0028] [Effects of the first embodiment] According to this embodiment, in an electronic timepiece 1 having a case 10 with a large planar size, the movement 20 other than the dial 2 and radiant electrode 52 is common to an electronic timepiece 1D having a case 10D with a small planar size, thereby reducing the manufacturing costs of electronic timepieces 1, 1D with different case sizes. That is, the main plate 21, drive mechanism 23, circuit board 70, etc. can be used in common in the electronic timepieces 1, 1D, and when incorporating into a case 10 that is larger in size than the main plate 21, it is only necessary to select and use the dial 2, radiant electrode 52, and inner frame 28 that correspond to the case size. Therefore, when configuring electronic timepieces 1, 1D with different sizes of dials 2, 2D and cases 10, 10D, a common movement 20 can be used, preventing increases in costs.

[0029] In the electronic timepiece 1, the planar size of the radiation electrode 52 of the planar antenna 50 is increased in accordance with the size of the case 10, improving the reception sensitivity of the planar antenna 50. In the planar antenna 50 of the electronic watch 1, only the size of the radiation electrode 52 has been increased, and the dielectric 51 and ground electrode 53 are common to the planar antenna 50D of the electronic watch 1D, so that the increase in cost of the planar antenna 50 can be kept to a minimum while improving reception sensitivity.

[0030] In the radiation electrode 52, the recess 502 and outer periphery 521 where the short-circuit portion 54 is provided are not expanded, but the other outer periphery 522 is expanded outward, so that the positions of the feed pin 56 and the conductive member 251 can be made common between the planar antennas 50 and 50D. This allows the use of the same circuit board 70, including the positions of the terminals with which the feed pin 56 and the conductive member 251 come into contact, and there is no need to change the circuit board 70 depending on the case size, thereby reducing costs. Furthermore, since the conductive member 251 is disposed in the recess 502 in which the short-circuit portion 54 is formed, that is, outside the short-circuit portion 54, the influence of the conductive member 251 made of a coil spring on the reception sensitivity can be reduced.

[0031] [Second embodiment] Next, an electronic timepiece 1B according to a second embodiment will be described with reference to FIGS. The electronic timepiece 1B differs from the electronic timepiece 1 of the first embodiment in the configuration of the planar antenna 50B, but the rest of the configuration is the same. Therefore, the same components as the electronic timepiece 1 of the first embodiment are given the same reference numerals and will not be described again.

[0032] As shown in FIGS. 8 and 9, the planar antenna 50B of the electronic timepiece 1B includes a radiation electrode 52B, a dielectric material 51B, a ground electrode 53B, and a short-circuit section 54B. The dielectric 51B also serves as a date dial holder (not shown) that holds the date dial. The radiation electrode 52B is made up of a metal coating formed on the front surface of the dielectric 51B. The short-circuiting portion 54B is made up of a metal coating formed on the side and back surface of the dielectric 51B. The metal coating can be formed by plating, for example, copper, silver, nickel, aluminum, or the like. Therefore, the dielectric 51B and the radiating electrode 52B have the same size in a planar view, and in this embodiment, they are formed to have a planar size larger than that of the solar panel 25. The dielectric 51B and the radiating electrode 52B also have an outer peripheral portion 521B whose outer peripheral surface is located inside the outer periphery of the ground plate 21, and an outer peripheral portion 522B located outside the ground plate 21. By providing this outer peripheral portion 522B, the area of ​​the radiating electrode 52B is larger than that of the radiating electrode 52D of the planar antenna 50D.

[0033] The ground electrode 53B is made of a metal plate and has a planar size larger than those of the dielectric 51B and the radiating electrode 52B. Therefore, in the planar antenna 50B, in addition to the radiating electrode 52B, at least a portion of the dielectric 51B and the ground electrode 53B also protrudes outward from the ground plate 21 in a planar view. That is, the radiating electrode 52B, the dielectric 51B, and the ground electrode 53B of the planar antenna 50B each have a portion that protrudes outward from the ground plate 21 in a planar view. Furthermore, the ground electrode 53B is formed in a size that covers almost the entire face of the drive mechanism 23 on the dial 2 side, and therefore also functions as a magnetic shield. The short-circuit portion 54B is electrically connected to the radiation electrode 52B, and is also electrically connected to the ground electrode 53B by contacting the short-circuit portion 54B. The short-circuit portion 54B is formed in the outer peripheral portion 521B and the recessed portion 502. Therefore, outer peripheral portion 522B of radiation electrode 52B and dielectric 51B protruding outward from ground plate 21 is other than outer peripheral portion 521B where short-circuit portion 54 is provided. On the other hand, ground electrode 53B protrudes outward from ground plate 21 except for recess 502 where conductive member 251 is disposed. These portions protruding outward from ground plate 21 overlap inner frame 28 in a plan view.

[0034] The radiation electrode 52B is electrically connected to the circuit board 70 via the feed pin 56. While FIG. 8 shows a schematic diagram of the electrical connection between the feed pin 56 and the radiation electrode 52B, in the planar antenna 50B, a metal coating is formed from the radiation electrode 52B, passing through the side surface of the dielectric 51B and reaching the rear surface to form a feed terminal, and the feed pin 56 is brought into contact with the feed terminal provided on the rear surface of the dielectric 51B for electrical connection. The planar positions of the feed pin 56 and the conductive member 251—that is, the positions of the feed pin 56 and the conductive member 251 relative to the central axes of the hands 35 to 37 in a planar view—are the same as those of the electronic timepieces 1 and 1D. Therefore, the electronic timepiece 1B also uses the same date wheel 5 and circuit board 70 as the electronic timepieces 1 and 1D. The conductive member 251, located in the recess 502, is located outside the short-circuit portion 54B.

[0035] [Effects of the second embodiment] In the electronic timepiece 1B of the second embodiment, the areas of the dielectric 51B and radiating electrode 52B of the planar antenna 50B are larger than those of the planar antenna 50D, and the ground electrode 53B is made larger than the radiating electrode 52B, thereby further improving the reception sensitivity of the planar antenna 50B.

[0036] The base plate 21, drive mechanism 23, secondary battery 24, solar panel 25, inner frame 28, power supply pin 56, circuit board 70, magnetic shield 81, circuit retainer 82, and conductive member 251 are the same as those in the electronic timepiece 1 and electronic timepiece 1D of the first embodiment, reducing costs. In other words, electronic timepieces 1, 1B, and 1D with different case sizes and antenna performance can be manufactured without increasing costs.

[0037] [Third embodiment] Next, an electronic timepiece 1C according to a third embodiment will be described with reference to FIGS. The electronic timepiece 1C differs from the electronic timepiece 1 in the configuration of the planar antenna 50C, solar panel 25C, conductive member 252, main plate 21C, and dial ring 16C, but has the same other configurations. Therefore, the same reference numerals are used for the configurations that are common to the electronic timepiece 1 of the first embodiment, and descriptions thereof will be omitted.

[0038] The planar antenna 50C of the electronic timepiece 1C includes a dielectric 51C, a radiation electrode 52C, a ground electrode 53C, and a short-circuit portion 54C. The dielectric 51C also serves as a date indicator holder (not shown) that holds the date indicator. The radiating electrode 52C is made up of a metal coating formed on the front side of the dielectric 51C, the ground electrode 53C is made up of a metal coating formed on the back side of the dielectric 51C, and the short-circuiting portion 54C is made up of a metal coating formed on the side of the dielectric 51C. The metal coating can be formed by plating, for example, copper, silver, nickel, aluminum, or the like. Therefore, the dielectric 51C, radiating electrode 52C, and ground electrode 53C are all the same size in a plan view.

[0039] The main plate 21C of the electronic timepiece 1C has a first region 211 to which the drive mechanism 23 is attached, and a second region 212 located on the outer periphery of the first region 211 and formed with dimensions corresponding to the difference between the inner diameter of the case 10 and the planar size of the first region 211. The first region 211 is configured with the same planar size as a main plate 21 that can be installed in the smallest case 10D. The width of the second region 212, i.e., the protrusion dimension from the first region 211 to the outer periphery of the second region 212, is set according to the case size. Therefore, the second region 212 of the main plate 21C abuts against the inner surface of the case 10, allowing the main plate 21C to be directly housed within the case 10 without the need for an inner frame. The second region 212 may abut against the inner surface of the case 10 along its entire periphery, or may abut against the inner surface of the case 10 at multiple locations.

[0040] The solar panel 25C has a larger area than the solar panel 25 of the electronic timepieces 1, 1B. The power generation layer of the solar panel 25C is set to have a smaller area than the radiation electrode 52C of the planar antenna 50C, expanding the area where the power generation layer of the solar panel 25 is not provided. Furthermore, the dial ring 16C is a member that covers a smaller area of ​​the dial 2 and solar panel 25C than the dial ring 16. Conduction member 252 is configured to include first coil spring 252A that contacts a terminal of solar panel 25C, second coil spring 252B that contacts a terminal of circuit board 70, and connecting portion 252C that connects first coil spring 252A and second coil spring 252B. Second coil spring 252B is disposed in first region 211 of ground plate 21C, and first coil spring 252A and connecting portion 252C are disposed in second region 212 of ground plate 21C. Furthermore, first coil spring 252A is disposed outside short-circuit portion 54C.

[0041] Because the first coil spring 252A of the conductive member 252 is positioned further outwards than the second coil spring 252B, the diameter of the date wheel 5 can be made larger than in the electronic watches 1 and 1B, and the date window 503 can be positioned further outwards. In this case, only the width dimension of the date wheel 5 is increased, and the positions of the internal teeth of the date wheel 5 and the date driving wheel are the same as those of the electronic watches 1 and 1B. Furthermore, since the first coil spring 252A is disposed on the outside, there is no need to form a recess in the planar antenna 50C for disposing the conductive member 252. Therefore, the outer periphery of the planar antenna 50C is expanded to a position that overlaps with the second region 212 of the ground plate 21C over the entire periphery.

[0042] [Effects of the third embodiment] The electronic timepiece 1C of the third embodiment not only has an enlarged area for the planar antenna 50C, but also for the solar panel 25C, improving reception sensitivity and power generation capacity. Furthermore, the drive mechanism 23, secondary battery 24, power supply pin 56, circuit board 70, magnetic shield 81, and circuit retainer 82 are common to the electronic watches 1, 1B, and 1D, reducing costs. The shape of the drive mechanism 23 retainer in the first area 211 of the main plate 21C can be formed in common with the electronic watches 1, 1B, and 1D, with only the second area 212 needing to be changed depending on the case size. This means that electronic watches 1, 1B, 1C, and 1D with different case sizes and antenna performance can be manufactured without increasing costs.

[0043] Because the first coil spring 252A of the conductive member 252 is positioned further outward than the second coil spring 252B, the diameter of the date indicator 5 can be increased and the date window 503 can be expanded further outward. In this case, because only the width dimension of the date indicator 5 is increased, there is no need to change the internal teeth of the date indicator 5 or the position of the date driving wheel, and increases in costs can be suppressed. Because the first coil spring 252A is positioned on the outer periphery of the solar panel 25C, the connection between the first coil spring 252A and the solar panel 25C can be covered by the dial ring 16C, improving the appearance of the electronic timepiece 1C.

[0044] [Other embodiments] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the present invention. For example, the shape of the planar antenna is not limited to an antenna that is approximately circular in plan view, but may also be rectangular or tonneau-shaped in plan view. For example, in an electronic timepiece using a case that is rectangular or tonneau-shaped in plan view, the shapes of the dial, solar panel, and planar antenna may be rectangular or tonneau-shaped to match the shape of the case, and other components such as the main plate 21 and drive mechanism 23 may be common to the electronic timepieces 1, 1B, and 1C of the above-mentioned embodiments. Note that a middle frame may be used to incorporate a circular main plate 21 into a case such as a rectangular case.

[0045] The planar antennas 50, 50B, and 50C are not limited to planar inverted-F antennas that resonate at 1 / 4 wavelength of the received signal, but may be other antennas such as thin patch antennas that resonate at 1 / 2 wavelength of the received signal. The dielectrics 51, 51B, 51C of the planar antennas 50, 50B, 50C are not limited to those that also serve as date indicator holders, but may also have the function of holding other timepiece parts, or may be provided exclusively for the antenna. In the planar antennas 50 and 50B, the outer peripheral portions 522 and 522B other than the short-circuit portions 54 and 54B protrude outside the base plate 21, but other portions than the recess 502, i.e., other portions of the short-circuit portions 54 and 54B other than those facing the conductive members 251 and 252, may also protrude outside the base plate 21.

[0046] The solar panel 25 of the electronic watches 1, 1B was the same size as the solar panel 25 of the electronic watch 1D, which had a smaller case size, but a solar panel with a larger area may be used to accommodate an increase in case size. In this case, the power generation layer of the solar panel 25 may be made smaller in area than the radiating electrodes 52, 52B of the planar antenna 50, and the portion without the power generation layer may be enlarged. In this case, the position of the conductive member 251 remains unchanged, so the solar panel may not be enlarged in the area overlapping the outer periphery 521, 521B, including the recess 502 where the short-circuit portions 54, 54B are provided, but the outer periphery of the solar panel may be enlarged in the area overlapping the outer periphery 522, 522B to increase its area.

[0047] The electronic timepieces 1, 1B, and 1C of the above-described embodiments are three-hand timepieces with hour hand 31, minute hand 32, and second hand 33, but the main plate 21, 21C or planar antenna 50, 50B, or 50C may be provided with shapes or through-holes that allow for the placement of other motors, wheel trains, or hand shafts. This configuration makes it easy to change the presence or absence of subdials or their positions by adding the corresponding motors or wheel trains or by changing the dial. This makes it easy to develop derivative electronic timepieces, such as by changing the case size and adding displays. Furthermore, the material of the case 10 is not limited to metal. For example, the case body 11 including the case case 12 and bezel 13, and the back cover 14 may be made of ceramic or synthetic resin.

[0048] The electronic watch may not have the solar panels 25, 25C and may use a primary battery instead of the secondary battery 24. In this case, the conductive members 251, 252 are not necessary and do not affect the reception sensitivity of the planar antennas 50, 50B, 50C, so the positions of the short-circuiting portions 54, 54B, 54C can be changed. The short-circuiting portions 54, 54B, 54C are provided to adjust the reception characteristics of the planar antennas 50, 50B, 50C, so if signals can be received without the short-circuiting portions 54, 54B, 54C, there is no need to provide the short-circuiting portions.

[0049] In the above-described embodiments, the antenna receives satellite signals transmitted from GPS satellites, but the signals received by the antenna are not limited to this. For example, the antenna may receive satellite signals transmitted from satellites of other global navigation satellite systems (GNSS) such as Galileo, GLONASS, and Beidou, geostationary satellite-based augmentation systems (SBAS), and regional navigation satellite systems (RNSS) that can be searched only in specific regions, such as quasi-zenith satellites. The antenna is not limited to one that receives satellite signals, but may also be an antenna that receives other radio waves, such as Bluetooth (registered trademark), BLE (Bluetooth Low Energy), Wi-Fi (registered trademark), NFC (Near Field Communication), LPWA (Low Power Wide Area), etc. In other words, the antenna incorporated into the electronic timepieces 1, 1B, 1C can be an antenna appropriate for the type of signal to be received, the size of the timepiece, how it fits in with other components, etc.

[0050] Summary of this disclosure The electronic timepiece disclosed herein comprises a case, hands, a dial, a drive mechanism for driving the hands, a base plate to which the drive mechanism is attached, an antenna arranged between the dial and the base plate in a side view seen from a direction parallel to the surface of the dial, and a circuit board, wherein the antenna has a plate-shaped radiation electrode, a plate-shaped ground electrode, and a dielectric arranged between the radiation electrode and the ground electrode in the side view, the circuit board is electrically connected to the radiation electrode via a power supply member, and the radiation electrode has a portion that protrudes outward beyond the base plate in a plan view seen from a direction perpendicular to the surface of the dial. In the electronic timepiece disclosed herein, the antenna is positioned between the dial and the main plate in a side view, allowing for a larger antenna area. Furthermore, the radiating electrode has a portion that protrudes outward from the main plate in a plan view, allowing for a larger radiating electrode area. This allows for the radiating electrode to be larger depending on the case size, improving the antenna's reception sensitivity.

[0051] In the electronic timepiece of this disclosure, the ground electrode and the dielectric preferably have portions that protrude outward beyond the base plate in the plan view. In addition to the radiation electrode, the areas of the ground electrode and the dielectric can also be increased, which further improves the receiving sensitivity of the antenna.

[0052] In the electronic timepiece disclosed herein, it is preferable that the electronic timepiece comprises a solar panel and a conductive member that provides electrical conductivity between the solar panel and the circuit board, the antenna has a short-circuiting portion that short-circuits the radiation electrode and the ground electrode, the conductive member and the short-circuiting portion overlap with the base plate in the planar view, and the conductive member is positioned outside the short-circuiting portion in the planar view. The antenna characteristics can be easily adjusted by providing a short circuit between the radiation electrode and the ground electrode. In addition, since the conductive member is positioned so that it overlaps with the ground plate in a plan view, it can be electrically connected to the circuit board at the position where it overlaps with the ground plate in a plan view, and the circuit board can also be shared. Furthermore, since the conductive member is disposed outside the short-circuit portion, the influence of the conductive member, which is formed of a coil spring or the like, on the reception sensitivity of the antenna can be reduced.

[0053] In the electronic timepiece disclosed herein, it is preferable that the antenna has a short-circuiting section that shorts the radiation electrode and the ground electrode, and that the portion of the radiation electrode that protrudes outward beyond the base plate is other than the short-circuiting section. In the radiation electrode of the antenna, the portion that protrudes outward from the ground plate is other than the short-circuit portion, so a large area other than the short-circuit portion can be protruded, effectively increasing the area of ​​the radiation electrode and improving the receiving sensitivity of the antenna. Furthermore, because the short-circuit portion does not protrude outward from the ground plate, when a connecting member is placed outside the short-circuit portion, the placement position can be fixed and circuit boards, etc. can be shared.

[0054] In the electronic timepiece disclosed herein, it is preferable that the portion of the radiation electrode that protrudes outward beyond the base plate is other than the portion of the short-circuiting portion that faces the conductive member. In the antenna's radiation electrode, the portion that protrudes outward from the ground plate is other than the portion facing the conductive member of the short-circuiting portion, so a wide area can be protruded, including not only the portion other than the short-circuiting portion but also the portion facing the conductive member of the short-circuiting portion, effectively increasing the area of ​​the radiation electrode and improving the antenna's receiving sensitivity. Furthermore, because the portion facing the conductive member of the short-circuiting portion does not protrude outward from the ground plate, the position of the connecting member can be fixed and circuit boards, etc. can be shared.

[0055] In the electronic timepiece disclosed herein, it is preferable that an inner frame be provided between the case and the base plate, and that the inner frame overlap with the radiation electrode in the plan view. By using an inner frame that matches the case size, a common ground plane can be attached to cases of various sizes. In addition, the radiation electrode can be expanded to the position of the inner frame, so the radiation electrode can be made larger depending on the case size, improving reception performance.

[0056] In the electronic timepiece of the present disclosure, it is preferable that the circuit board be formed to a size corresponding to the drive mechanism, and that the power supply member overlap the main plate and the circuit board in the plan view. The circuit board is sized to fit the drive mechanism, so like the base plate, it can be kept to a minimum size. This allows a common circuit board to be used for the base plate, drive mechanism, and multiple types of cases of different sizes, preventing increases in costs. Furthermore, since the power supply member that connects the antenna and circuit board overlaps the base plate and circuit board in a plan view, the position of the power supply member can be kept constant regardless of the case size, which also allows the circuit board to be standardized.

[0057] The electronic timepiece disclosed herein comprises a case, hands, a dial, a drive mechanism that drives the hands, a base plate to which the drive mechanism is attached, an antenna that is arranged between the dial and the base plate in a side view seen from a direction parallel to the surface of the dial, and a circuit board, wherein the base plate has a first region to which the drive mechanism is attached and a second region that is provided on the outer periphery of the first region and abuts the case, the antenna has a plate-shaped radiating electrode, a plate-shaped ground electrode, and a dielectric that is arranged between the radiating electrode and the ground electrode in the side view, the circuit board is electrically connected to the radiating electrode via a power supply member, the dial is formed to a size that corresponds to the case, and the radiating electrode has a portion that overlaps the second region in a planar view seen from a direction perpendicular to the surface of the dial. According to the electronic watch of the present disclosure, the base plate has a first area where the drive mechanism is attached and a second area that abuts the case. Therefore, for multiple types of cases with different sizes, it is sufficient to use a base plate with a different dimension of the second area and a dial of a size that corresponds to the case, and other parts such as the drive mechanism can be standardized, preventing increases in costs. In addition, because the antenna is positioned between the dial and the base plate in a side view, the antenna area can be increased. Furthermore, because the radiating electrode has a portion that overlaps with the second region of the base plate in a plan view, the area of ​​the radiating electrode can be further increased. This allows the radiating electrode to be larger depending on the case size, improving the antenna's reception sensitivity. [Explanation of symbols]

[0058] 1...electronic watch, 1B...electronic watch, 1C...electronic watch, 1D...electronic watch, 2...dial, 2D...dial, 3...hand, 5...date indicator, 10...case, 10D...case, 20...movement, 21...main plate, 21C...main plate, 23...driving mechanism, 24...secondary battery, 25...solar panel, 25C...solar panel, 28...center frame, 31...hour hand, 32...minute hand, 33...second hand, 50...flat antenna, 50B...flat antenna, 50C...flat antenna, 50D...flat antenna, 51...dielectric, 51B...dielectric, 51C...dielectric, 52...radiation pole, 52B...radiating electrode, 52C...radiating electrode, 52D...radiating electrode, 53...ground electrode, 53B...ground electrode, 53C...ground electrode, 54...short circuit portion, 54B...short circuit portion, 54C...short circuit portion, 56...feed pin, 70...circuit board, 81...magnetic shield, 82...circuit retainer, 211...first region, 212...second region, 251...conductive member, 252...conductive member, 252A...first coil spring, 252B...second coil spring, 252C...connecting portion, 502...recess, 521...outer periphery, 521B...outer periphery, 522...outer periphery, 522B...outer periphery.

Claims

1. Case and Guidelines and The dial and a drive mechanism for driving the pointer; a base plate to which the drive mechanism is attached; an antenna disposed between the dial and the main plate in a side view seen in a direction parallel to the surface of the dial; a circuit board; The antenna is a plate-shaped radiation electrode; a plate-shaped ground electrode; a dielectric disposed between the radiation electrode and the ground electrode in the side view, the circuit board is electrically connected to the radiation electrode via a power supply member; The radiation electrode has a portion that protrudes outward beyond the base plate in a plan view seen from a direction perpendicular to the surface of the dial. An electronic watch characterized by:

2. 2. The electronic timepiece according to claim 1, The ground electrode and the dielectric have portions that protrude outward beyond the base plate in the plan view. An electronic watch characterized by:

3. 3. The electronic timepiece according to claim 1, Solar panels and a conductive member that electrically connects the solar panel and the circuit board, the antenna has a short-circuiting portion that short-circuits the radiation electrode and the ground electrode, the conductive member and the short-circuit portion overlap with the ground plane in the plan view, The conductive member is disposed outside the short-circuit portion in the plan view. An electronic watch characterized by:

4. 4. The electronic timepiece according to claim 1, the antenna has a short-circuiting portion that short-circuits the radiation electrode and the ground electrode, The portion of the radiation electrode that protrudes outward beyond the ground plane is other than the short-circuit portion. An electronic watch characterized by:

5. 4. The electronic timepiece according to claim 3, The portion of the radiation electrode that protrudes outward beyond the ground plane is other than the portion of the short-circuit portion that faces the conductive member. An electronic watch characterized by:

6. 6. The electronic timepiece according to claim 1, a middle frame disposed between the case and the base plate, The inner frame overlaps with the radiation electrode in the plan view. An electronic watch characterized by:

7. 7. The electronic timepiece according to claim 1, the circuit board is formed to a size corresponding to the drive mechanism; The power supply member overlaps the base plate and the circuit board in the plan view. An electronic watch characterized by:

8. Case and Guidelines and The dial and a drive mechanism for driving the pointer; a base plate to which the drive mechanism is attached; an antenna disposed between the dial and the main plate in a side view seen in a direction parallel to the surface of the dial; a circuit board; the base plate has a first region to which the drive mechanism is attached and a second region provided on the outer circumferential side of the first region and in contact with the case, The antenna is a plate-shaped radiation electrode; a plate-shaped ground electrode; a dielectric disposed between the radiation electrode and the ground electrode in the side view, the circuit board is electrically connected to the radiation electrode via a power supply member; The dial is formed to a size corresponding to the case, The radiation electrode has a portion that overlaps the second region in a plan view seen from a direction perpendicular to the surface of the dial. An electronic watch characterized by:

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