Electronic clock

Abstract

To provide an electronic clock capable of suppressing a decrease in reception performance of an aerial and expanding an area of a power generation part.SOLUTION: An electronic clock includes: a dial; a solar cell which is disposed on a reverse surface side of the dial and is provided with a power generation part converting light into electric energy; an aerial which is disposed on the reverse surface side of the solar cell and has a plate-shaped first conductor element overlapping the power generation part in a planar view seen from the direction orthogonal to the surface of the dial, a plate-shaped second conductor element overlapping the first conductor element in a planar view, and a short-circuit part connected to an outer periphery of the first conductor element and short-circuiting the first conductor element and the second conductor element. The outer periphery of the first conductor element is composed of a connection part connected to the short circuit part and a non-connection part not connected to the short circuit part. At least a part of the non-connection part is located outside the power generation part in a planar view. The power generation part has an overlapping part overlapping the connection part.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] Patent Document 1 discloses an electronic timepiece incorporating a solar cell and an antenna for receiving satellite signals. The antenna is a plate-shaped inverted-F antenna with a radiation electrode that is disposed on the back side of the solar cell and overlaps with the solar cell, and it is disclosed that a portion of the outer periphery of the radiation electrode is located outside the power generation section of the solar cell in a planar view. Specifically, it discloses a configuration in which the entire outer periphery of the radiation electrode is located outside the power generation section, and a configuration in which a first power generation section is provided inside the radiation electrode and a second power generation section is provided outside a first non-power generation section that surrounds the first power generation section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-191146 Summary of the Invention [Problem to be solved by the invention]

[0004] In the electronic timepiece of Patent Document 1, the power generating unit is placed outside the radiation electrode in order to increase the area of ​​the power generating unit, but there is a problem in that depending on the position of the power generating unit, the reception performance of the antenna can be significantly reduced. [Means for solving the problem]

[0005] The electronic timepiece disclosed herein comprises a dial, a solar cell arranged on the back side of the dial and having a power generation unit that converts light into electrical energy, a plate-shaped first conductor element arranged on the back side of the solar cell and overlapping the power generation unit in a planar view seen from a direction perpendicular to the surface of the dial, a plate-shaped second conductor element that overlaps the first conductor element in the planar view, and an antenna connected to the outer periphery of the first conductor element and having a short-circuiting portion that short-circuits the first conductor element and the second conductor element, wherein the outer periphery of the first conductor element is composed of a connection portion that connects to the short-circuiting portion and a non-connection portion that is not connected to the short-circuiting portion, at least a portion of the non-connection portion is located outside the power generation unit in the planar view, and the power generation unit has an overlapping portion that overlaps the connection portion. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a front view showing an electronic timepiece according to a first embodiment. [Figure 2] 1 is a cross-sectional view showing 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 an exploded oblique view showing the antenna, solar panel, and movement of the electronic timepiece according to the first embodiment. [Figure 5] FIG. 2 is an exploded perspective view showing the antenna and the antenna auxiliary member of the first embodiment. [Figure 6] FIG. 2 is a plan view showing the antenna and solar panel of the electronic timepiece according to the first embodiment. [Figure 7] FIG. 10 is a plan view showing an antenna and a solar panel according to a second embodiment. [Figure 8] FIG. 10 is a plan view showing an antenna and a solar panel according to a third embodiment. [Figure 9] FIG. 10 is a plan view showing an antenna and a solar panel according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] [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.

[0008] The electronic watch 1 of this embodiment has a built-in antenna 50, which will be described later, and is configured to receive satellite signals from multiple positioning information satellites S, such as GPS satellites and quasi-zenith satellites, that orbit the Earth in a predetermined orbit, as shown in Figure 1, to obtain satellite time information and correct the internal time information.

[0009] 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.

[0010] [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.

[0011] 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.

[0012] [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, the solar panel 25 which is a solar cell, the antenna 50, the antenna auxiliary member 60, and the like.

[0013] The dial 2 is formed into a circular disk shape from a non-conductive material. In this embodiment, the dial 2 is made of polycarbonate resin with a 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, which serves as an indicator, 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 wheel train, which will be described later. Note that the indicator wheel is not limited to the date wheel 5, and may be one that displays calendar information such as a day of the week indicator, or one that displays information other than the calendar.

[0014] 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 dielectric constant of 3.

[0015] The movement 20 includes a main plate 21, a drive mechanism 23, a secondary battery 24, a solar panel 25, an antenna 50, a circuit board 70, a magnetic shield 81, a circuit holder 82, etc. Although not shown, 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.

[0016] 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.

[0017] 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 antenna 50, and a control IC that controls the drive of hour hand 31, minute hand 32, second hand 33, and date wheel 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.

[0018] [antenna] The 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 to 5, the antenna 50 is disposed so as to overlap the cover crystal 15 and the solar panel 25 in a plan view, and is disposed between the solar panel 25, which is disposed on the back side of the dial 2, and the main plate 21 in a side view seen in a direction parallel to the surface of the dial 2. For this reason, the antenna 50 also serves as a support substrate that supports the solar panel 25 made of film. The antenna 50 is configured to include a dielectric 51, a plate-shaped first conductor element 52, a plate-shaped second conductor element 53 arranged to overlap the first conductor element 52 in a planar view, and a short-circuit portion 54 that short-circuits the first conductor element 52 and the second conductor element 53. A through-hole 501, through which the pointer shafts 35 to 37 are inserted, is formed in the planar center position of the antenna 50. That is, the through-hole 501 is formed by passing through the first conductor element 52, the dielectric 51, and the second conductor element 53. In the antenna 50, the date wheel 5 is disposed between the dielectric 51, on the surface of which the first conductor element 52 is formed, and the second conductor element 53, and a date window 503 for viewing the date wheel 5 is formed in the dielectric 51 and the first conductor element 52 at a position that overlaps with the date windows 2B, 256 in a planar view. 3 to 5, a recess 502 is formed on the outer peripheral surface of the antenna 50. In the recess 502, a conductive member 251 is disposed, as shown in FIG.

[0019] Dielectric 51 is made of a dielectric material such as polyphenylene sulfide, liquid crystal polymer, or polycarbonate, and is disposed between first conductive element 52 and second conductive element 53 in side view. Dielectric 51 made of these materials has a dielectric constant of approximately 2 to 4. 5, the dielectric 51 comprises a thin plate-shaped dielectric body 51A, an inner circumference protrusion 51B formed on the back surface of the dielectric body 51A at a position on the inner circumference side of the date indicator 5 in a plan view, and an outer circumference protrusion 51C formed at a position on the outer circumference side of the date indicator 5. The outer circumference protrusion 51C is formed in a range from approximately the 12 o'clock position to approximately the 3 o'clock position on the dial 2 in a plan view. The dielectric 51 has a dielectric body 51A which is a thin plate portion, and an inner peripheral protrusion 51B and an outer peripheral protrusion 51C which are thick portions. The dielectric 51 has the function of pressing the date wheel 5 against the main plate 21.

[0020] The first conductive element 52 is formed of a metal coating formed on the surface of the dielectric 51, i.e., the surface on the dial 2 side, and is electrically connected to the circuit board 70 via the feed pin 56. Therefore, the first conductive element 52 is a plate-shaped first conductive element connected to the feed pin 56, which is the power supply section, and functions as a radiating electrode of the plate-shaped inverted-F antenna. The metal coating forming first conductive element 52 can be formed by plating, for example, gold, copper, silver, nickel, aluminum, or the like. While Fig. 2 shows feed pin 56 as penetrating second conductive element 53 and dielectric 51 to contact first conductive element 52, in reality, as shown in Fig. 5, feed terminal 55 formed of a metal coating that is conductive to first conductive element 52 is formed on the side surface of outer peripheral protrusion 51C of dielectric 51 to the underside, and the upper end of feed pin 56, which serves as a power feed portion, is in contact with feed terminal 55. First conductive element 52 is not limited to a metal coating formed on dielectric 51 by plating or the like, and may also be formed from a thin metal plate made of, for example, copper, iron alloy, or the like. 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.

[0021] The second conductive element 53 is formed of a thin metal plate such as copper or iron alloy, and is electrically connected to the ground terminal of the circuit board 70. The second conductive element 53 functions as a ground electrode of the planar inverted-F antenna. 2 and 4, second conductive element 53 is a plate-shaped second conductive element that overlaps with first conductive element 52 in a plan view. Second conductive element 53 is formed in a size that covers almost the entire surface of main plate 21, and serves both as a magnetic shield that covers the dial 2 side of the step motor and as an hour wheel holder that holds down the hour wheel. Second conductive element 53 does not come into contact with power supply terminal 55, but does come into contact with short-circuit portion 54 for electrical continuity.

[0022] The short-circuiting portion 54 is formed of a metal coating formed by plating or the like on the side and back surfaces of the outer peripheral protrusion 51C of the dielectric 51, and is electrically connected to the first conductive element 52 and the second conductive element 53. The length of the short-circuiting portion 54 is set according to the frequency of the radio waves received by the antenna 50. The reception frequency of the antenna 50 can be adjusted by the size of the antenna 50 and the dielectric constant of the dielectric 51. Therefore, in order to receive satellite signals from GPS satellites with the antenna 50, the length of the short-circuiting portion 54 is adjusted according to the size of the antenna 50 and the dielectric constant of the dielectric 51. 6, the short-circuiting portion 54 of this embodiment is provided on the dial 2 from approximately the 12 o'clock position to approximately the 3.5 o'clock position, that is, in a range R1 having a central angle of approximately 110 degrees. Therefore, the short-circuiting portion 54 is also provided in the recess 502 of the dielectric 51, and the conductive member 251 is disposed outside the short-circuiting portion 54 in the recess 502. 4 to 6, the outer periphery of the first conductive element 52 has a connection portion 521 that connects to the short-circuit portion 54 and a non-connection portion 522 that is not connected to the short-circuit portion 54. As shown in Fig. 6, the connection portion 521 is provided in the same range R1 as the short-circuit portion 54, and the non-connection portion 522 is provided in a range R2 outside the range R1. In this embodiment, the feed pin 56, which is the power supply part of the antenna 50, is arranged within a range of ±45 degrees from the 12 o'clock position on the dial 2, that is, within a 90-degree range from the 10.5 o'clock position to the 1.5 o'clock position on the dial 2. As shown in FIG. 6, the feed pin 56 in this embodiment is located approximately near the 12 o'clock position on the dial 2 in a plan view, specifically at a position approximately -5 degrees from the 12 o'clock position. This allows the directivity of the antenna 50 to be directed toward the 9 o'clock direction on the dial 2. The entire short-circuit portion 54 is provided within a range of 180 degrees clockwise from the power supply pin 56. This configuration also allows the directivity of the antenna 50 to be directed toward the 9 o'clock direction of the dial 2.

[0023] [Antenna auxiliary components] The antenna auxiliary member 60 is a dielectric auxiliary member made of a high-dielectric material having a higher dielectric constant than the dielectric 51 of the antenna 50. That is, since the dielectric constant of the dielectric 51 is approximately 2 to 4, the antenna auxiliary member 60 is made of a synthetic resin or the like having a dielectric constant of 5 or more, preferably 8 or more. When the dielectric constant of the antenna auxiliary member 60 is 8 or more, since the dielectric constant of the dielectric 51 is approximately 2 to 4, the dielectric constant of the antenna auxiliary member 60 is at least twice that of the dielectric 51. As shown in Figures 2, 4 and 5, the antenna auxiliary member 60 is arranged outside the date wheel 5 in a plan view, and is arranged between the first conductor element 52 and the second conductor element 53 in a side view, specifically between the dielectric body 51A, which is the thin plate portion of the dielectric 51, and the second conductor element 53. 4 and 5, the antenna auxiliary member 60 includes an arc portion 61 formed in an arc shape, guide recesses 62, screw fastening portions 63, and protrusions 64. The guide recesses 62 are formed at four locations on the inner periphery of the arc portion 61. The screw fastening portions 63 are formed at three locations on the outer periphery of the arc portion 61: both ends and a middle portion. A guide pin 211 formed on the synthetic resin base plate 21 is placed in the guide recess 62. This allows the antenna support member 60 to be positioned. The screw fastening portions 63 are formed with through holes through which screws 65 are inserted. The antenna auxiliary member 60 is fixed to the base plate 21 by the screws 65. The screws 65 inserted into the screw fastening portions 63 at both ends of the antenna auxiliary member 60 fix only the antenna auxiliary member 60 to the base plate 21, and the screw 65 inserted into the screw fastening portion 63 in the center fastens the screw fastening portion 63 together with the screw fastening portion 513 formed in the dielectric 51 of the antenna 50. The screw 65 is also provided so as not to come into contact with any metal part set to the ground potential, so that it is in an electrically floating state. The protrusions 64 are formed at four locations on the inner periphery of the arc portion 61 so as to protrude toward the dielectric body 51A in side view. The upper surfaces of the protrusions 64 are flat and come into contact with the lower surface of the dielectric body 51A. The upper surfaces of the above-mentioned guide pins 211 also come into contact with the lower surface of the dielectric body 51A, and the protrusions 64 and the guide pins 211 support the dielectric body 51A so that the dielectric 51 does not bend downward.

[0024] The antenna auxiliary member 60 is formed in a planar arc shape with a central angle of 90° or more, specifically approximately 180°. The antenna auxiliary member 60 is arranged in a range from approximately the 5 o'clock position on the dial 2 clockwise to approximately the 11 o'clock position, and is arranged so as to overlap in plan view with the non-connected portion 522 on the open end side of the antenna 50. The non-connected portion 522 that overlaps with the antenna auxiliary member 60 in plan view is arranged so as to overlap with the non-power generation portion 270, as will be described later. In other words, at least the area of ​​the non-connected portion 522 that overlaps with the antenna auxiliary member 60 in plan view is located outside the solar cell, which is the power generation portion.

[0025] [Solar panel] As shown in Figures 3 to 6, the solar panel 25 is a solar cell panel formed in an approximately circular disk shape and used for wristwatches, and is equipped with a through hole 255 through which the hand axes 35 to 37 are inserted, a date window 256 for viewing the date wheel 5, solar cells 261 to 268, and two electrode terminals 250. The solar cells 261 to 268 are divided by a plurality of division lines that extend from the through-hole 255 toward the outer periphery. In this embodiment, there are eight division lines, and eight solar cells 261 to 268 are provided. Each solar cell 261-268 has, for example, a resin substrate, a metal electrode, a semiconductor layer, a transparent electrode, and a protective layer laminated in this order from the antenna 50 side to the dial 2 side, and functions as a power generation section that converts light into electrical energy. The semiconductor layer is formed so that a p-type semiconductor and an n-type semiconductor sandwich an i-type semiconductor. However, the configuration of the solar cells 261-268 is not limited to this. The solar cells 261 to 268 are arranged clockwise from the 1 o'clock position on the dial 2. A date window 256 is formed in the solar cell 262. The solar cells 261 to 268 are connected in series clockwise from solar cell 261 to solar cell 268, and an electrode terminal 250, with which a conductive member 251 comes into contact, is formed on the back surface of each of the solar cells 261 and 268. Electrical continuity is established between the electrode terminal 250 and the circuit board 70 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.

[0026] 6, in each of the solar cells 261-268, which are the power generating portion, in a portion that overlaps with the connection portion 521, i.e., the short-circuit portion 54, on the periphery of the first conductive element 52 of the antenna 50 in a plan view, the solar cell extends to the outer periphery side of the connection portion 521. Specifically, the portion of the range R1 in the solar cells 261, 262, 268 extends to the periphery of the solar panel 25. Therefore, the solar cells 261, 262, 268 have an overlapping portion that overlaps with the connection portion 521 in a plan view. In this embodiment, the range in which the solar cell, which is the power generating unit, overlaps with the outer periphery of the first conductive element 52 is range R1 in which the connection portion 521 is formed, that is, a range with a central angle of approximately 110 degrees. Therefore, the range in which the solar cell overlaps with the outer periphery of the first conductive element 52 is within ±90 degrees, or 180 degrees, of an imaginary line connecting the center of the dial 2 and the center of the short-circuit portion 54. The center of the short-circuit portion 54 is located halfway in the circumferential direction of range R1. On the other hand, in the solar panel 25, no solar cell is formed in the portion that overlaps with the non-connected portion 522 on the periphery of the first conductive element 52 in a planar view, and a non-power-generating portion 270 of the solar panel 25 is arranged therein. In other words, the entire non-connected portion 522 is located outside the solar cell. Therefore, the non-power-generating portion 270 is provided on the outer periphery side of the solar cells 262 to 268 within the range R2 of the solar panel 25. The non-power-generating portion 270 does not have the metal electrodes and transparent electrodes that the solar cells 261 to 268 have, and is therefore transparent to radio waves received by the antenna 50. Specifically, the non-power-generating portion 270 is formed by, for example, laminating a resin substrate, a semiconductor layer, and a protective layer in this order from the antenna 50 side to the dial 2 side. Note that the structure of the non-power-generating portion 270 does not have to be as described above; for example, the semiconductor layer may be omitted.

[0027] By adjusting the size of the date window 256 and the position and shape of the dividing lines of each solar cell 261-268, each solar cell 261-268, including the solar cells 261, 262, 268 with extended outer peripheries, is set to have approximately the same area.

[0028] [Antenna characteristics and power generation performance] Simulation analysis of the antenna characteristics of antenna 50 revealed that antenna 50 receives radio waves from the open end opposite short-circuit portion 54, with the electric field density being higher at the open end. On the other hand, the electric field density at short-circuit portion 54 is low, which reduces the influence of the metal electrode of the solar cell. For this reason, by forming a solar cell in the portion that overlaps with short-circuit portion 54 in a planar view, i.e., the portion that overlaps with connection portion 521 of first conductive element 52 in a planar view, it is possible to expand the area of ​​the solar cell, i.e., the power generation portion, without degrading antenna performance. Furthermore, by increasing the area of ​​the antenna 50 or using a dielectric 51 with a low dielectric constant, it is possible to lengthen the short-circuit portion 54 of the antenna 50. If the short-circuit portion 54 is lengthened, the area of ​​the solar cell that overlaps with the short-circuit portion 54 in a plan view can be increased, thereby improving power generation performance.

[0029] [Effects of the first embodiment] In electronic timepiece 1, solar cells are formed in areas that overlap short-circuit portion 54 of antenna 50, i.e., connection portion 521, in a planar view. This allows the solar cells to be expanded to the outer periphery of solar panel 25 in area R1 where short-circuit portion 54 is formed, thereby increasing the area of ​​solar cells 261-268, i.e., the entire power generation unit, and improving power generation performance. Furthermore, non-connection portion 522 of first conductive element 52 overlaps non-power generation portion 270 in a planar view, but not the solar cells, improving power generation performance without degrading antenna performance. This ensures sufficient area for solar cells 261-268, which form the power generation unit, and ensures the power required for hand movement and reception, even when multiple hands are provided or the dial is fitted with a timepiece ring or other attachment.

[0030] Since the power generation performance can be improved by increasing the power generation area of ​​the solar panel 25, the necessary amount of power generation can be secured even if the light transmittance of the dial 2 is reduced. By reducing the light transmittance of the dial 2, the solar panel 25 becomes less visible from the dial 2, improving the design and enhancing the luxurious feel of the electronic timepiece 1. By setting the position of the power supply pin 56 and the short circuit section 54, the antenna directivity can be directed toward the 9 o'clock direction of the dial, so when the user is walking outdoors with the electronic watch 1 worn on the left wrist, the 9 o'clock direction of the electronic watch 1 is approximately in the direction of the zenith, making it easier to receive satellite signals from the zenith direction.

[0031] [Second embodiment] Next, an electronic timepiece 1B according to a second embodiment will be described with reference to FIG. The electronic timepiece 1B includes a case 10B, a movement 20, an antenna 50B, a solar panel 25B, and a dial (not shown). The movement 20 includes a main plate 21 and other components and has the same configuration as in the first embodiment, so a description thereof will be omitted. Antenna 50B is not generally circular in shape, but has an asymmetrical shape. That is, antenna 50B has an asymmetrical shape with respect to an imaginary line connecting 12 o'clock and 6 o'clock on the dial. Antenna 50B includes a first conductive element 52B that is a radiation electrode, and the outer periphery of first conductive element 52B has a connection portion 521B that connects to short-circuit portion 54B of antenna 50B and a non-connection portion 522B that is not connected to short-circuit portion 54B. The dimension (diameter) from the planar center of the first conductor element 52B, i.e., from the through hole 255 of the solar panel 25, to the connection portion 521B is smaller than the dimension (diameter) from the planar center of the first conductor element 52B to the non-connection portion 522B. In other words, the connection portion 521B is disposed inside the outer periphery of the ground plate 21 in a planar view, whereas the non-connection portion 522B protrudes outside the outer periphery of the ground plate 21 in a planar view.

[0032] Antenna 50B is formed with a recess 502 in which conductive member 251 is disposed. Recess 502 is formed so as to be recessed further inward than connection portion 521B. Furthermore, a feed pin 56 that is electrically connected to first conductive element 52B of antenna 50B is disposed near recess 502. The dimension from through hole 255 of solar panel 25 to conductive member 251 is approximately the same as the dimension from through hole 255 to feed pin 56. Short-circuit portion 54B is located clockwise from feed pin 56, which is the power supply portion. Therefore, short-circuit portion 54B is formed in recess 502 and in the portion that continues clockwise from recess 502, i.e., the portion that overlaps solar cells 261B and 262B in a plan view. Therefore, short-circuit portion 54B is located radially and continuously toward the edge of non-connected portion 522B in the region that overlaps solar cell 262B, and connection portion 521B that connects to short-circuit portion 54B also includes a substantially arc-shaped portion and a portion that extends from the substantially arc-shaped edge toward the outer periphery. In this embodiment, feed pin 56 is located within a range of ±45 degrees from the 12 o'clock position on the dial, and the entire short-circuit portion 54B is located within a range of 180 degrees clockwise from feed pin 56, so that the antenna directivity is set to the 9 o'clock direction.

[0033] Solar panel 25B is formed in a substantially circular plate shape and includes eight solar cells 261B to 268B divided by eight dividing lines that radiate from through-hole 255 formed in the center of the plane. The outer periphery of each of solar cells 261B to 268B is located outside connection portion 521B and inside non-connection portion 522B. Therefore, solar cells 261B, 262B, and 268B have overlapping portions that overlap short-circuit portion 54B, that is, connection portion 521B, in a planar view.

[0034] [Effects of the second embodiment] In the electronic watch 1B, in the antenna 50B, the connection portion 521B that connects to the short-circuit portion 54B overlaps with the solar cells 261B, 262B, and 268B in a planar view, but the non-connection portion 522B is positioned on the outer periphery of the solar cells 262B to 268B, so that, as in the first embodiment, it is possible to ensure a sufficient power generation area without reducing antenna performance. Furthermore, because the conductive member 251 and power supply pin 56 are positioned inside the outer periphery of the main plate 21, i.e., inside the movement 20, the movement 20 can be shared with an electronic timepiece 1C of a third embodiment, described below, reducing costs. Furthermore, when an electronic timepiece 1B with a large planar size is constructed using a case 10B, antenna 50B, and solar panel 25B, the sizes of the antenna 50B and solar panel 25B can be made larger than the movement 20, improving antenna performance and power generation performance. The connection part 521B of the antenna 50B is provided inside the outer periphery of the base plate 21, and the non-connection part 522B is provided outside the outer periphery of the base plate 21, so that the solar panel 25B can have a simple disk-like shape overall and there is no need to provide a non-power generating part, thereby reducing manufacturing costs.

[0035] [Third embodiment] Next, an electronic timepiece 1C according to a third embodiment will be described with reference to FIG. The electronic timepiece 1C includes a case 10C, a movement 20, an antenna 50C, a solar panel 25C, and a dial (not shown). The movement 20 includes a main plate 21 and other components and has the same configuration as the first and second embodiments, so a description thereof will be omitted. Antenna 50C has a generally circular shape in plan view. That is, antenna 50C has a shape symmetrical with respect to an imaginary line connecting 12 o'clock and 6 o'clock on the dial. Antenna 50C includes a first conductive element 52C that serves as a radiation electrode, and the outer periphery of first conductive element 52C has a connection portion 521C that connects to short-circuit portion 54C of antenna 50C and a non-connection portion 522C that is not connected to short-circuit portion 54C. The dimension (diameter) from the planar center of first conductor element 52C, i.e., from through hole 255 of solar panel 25, to connection portion 521C is the same as the dimension (diameter) from the planar center of first conductor element 52C to non-connection portion 522C. In other words, connection portion 521C and non-connection portion 522C are arranged inside the outer periphery of ground plate 21 in plan view.

[0036] Antenna 50C is formed with a recess 502 in which conductive member 251 is disposed. Recess 502 is formed so as to be recessed further inward than connection portion 521C. Furthermore, a power feed pin 56 that is electrically connected to first conductive element 52C of antenna 50C is disposed near recess 502. The dimension from through hole 255 of solar panel 25 to conductive member 251 is approximately the same as the dimension from through hole 255 to power feed pin 56.

[0037] Solar panel 25C is formed in a substantially circular plate shape and includes eight solar cells 261C to 268C divided by eight dividing lines that radiate from through-hole 255 formed in the center of the plane. Each of solar cells 261C, 262C, 268C has an overlapping portion that overlaps short-circuit portion 54C, i.e., connection portion 521C, in a planar view. On the other hand, the portion of solar panel 25C that overlaps with non-connection portion 522C in plan view is defined as non-power generating portion 270C. Non-power generating portion 270C is formed in an arc shape on the outer periphery of solar cells 263C to 268C.

[0038] [Effects of the third embodiment] According to the electronic watch 1C, in the antenna 50C, the connection portion 521C that connects to the short-circuit portion 54C overlaps with the solar cells 261C, 262C, and 268C in a planar view, but the non-connection portion 522C is positioned on the outer periphery of the solar cells 263C to 268C and overlaps with the non-power generating portion 270C in a planar view, so that, as in the first embodiment, the power generating area can be secured without reducing the antenna performance. Furthermore, because the conductive member 251 and power supply pin 56 are located inside the outer periphery of the main plate 21, i.e., inside the movement 20, the movement 20 can be shared with the electronic timepiece 1B of the second embodiment, reducing costs. Furthermore, by using the same movement 20 and the same case 10C, antenna 50C, and solar panel 25C, an electronic timepiece 1C with a small planar size can be constructed. In other words, by using the same movement 20 and selecting only the minimum number of parts, such as the cases 10B and 10C, solar panels 25B and 25C, and antennas 50B and 50C, two types of electronic timepieces 1B and 1C of different sizes can be constructed at low cost.

[0039] [Fourth embodiment] Next, an electronic timepiece 1D according to a fourth embodiment will be described with reference to Fig. 9. Fig. 9 shows an antenna 50D and solar panel 25D of the electronic timepiece 1D. Antenna 50D has a generally circular shape in plan view. Antenna 50D includes first conductive element 52D, which is a radiation electrode. The outer periphery of first conductive element 52D has connection portion 521D that connects to short-circuit portion 54D of antenna 50D and non-connection portion 522D that is not connected to short-circuit portion 54D. Short-circuit portion 54D and connection portion 521D are arranged within a range of a central angle of approximately 130 degrees. The dimension (diameter) from the planar center of the first conductor element 52D, that is, from the through hole 255 of the solar panel 25D to the connection portion 521D is the same as the dimension (diameter) from the planar center of the first conductor element 52D to the non-connection portion 522D. A feed pin 56 that is electrically connected to the first conductive element 52D is disposed near the outer periphery of the antenna 50D and near the end of the non-connected portion 522D.

[0040] Solar panel 25D is formed in a substantially circular plate shape and includes eight solar cells 261D-268D partitioned by eight dividing lines that radiate from through-hole 255 formed in the center of the plane. Solar cells 261D, 262D, 263D, and 268D extend to the outer periphery of short-circuit portion 54D, i.e., connected portion 521D and non-connected portion 522D. The outer peripheries of the remaining solar cells 264D-267D are located inside non-connected portion 522D, and non-power generating portion 270D is provided on the outer periphery of these solar cells 264D-267D. That is, of the eight solar cells 261D to 268D, the four solar cells 261D, 262D, 263D, and 268D located on the side of short-circuit portion 54D, i.e., the solar cells within a central angle of 180 degrees, have overlapping portions that overlap connection portion 521D and short-circuit portion 54D in a planar view, and the outer periphery of each solar cell extends beyond connection portion 521D. On the other hand, the four solar cells 264D-267D on the side opposite to the short-circuit portion 54D, i.e., the open end side of the antenna 50D, are arranged inside the non-connected portion 522D and are configured so as not to overlap with the non-connected portion 522D in a planar view. For this reason, the non-power-generating portion 270D is formed in an arc shape with a central angle of 180 degrees around the outer periphery of the solar cells 264D-267D. For this reason, both ends of the non-connected portion 522D overlap with the solar cells 263D and 268D, but the middle portion, i.e., at least a part of the non-connected portion 522D, is located outside the solar cells 264D-267D. The conductive member 251 is disposed near the outer periphery of the solar cells 261D and 268D, and is provided on the outer periphery side of the power supply pin 56.

[0041] [Effects of the fourth embodiment] In the electronic timepiece 1D, the areas of the solar cells 261D to 263D and 268D are large within a central angle of 180 degrees, which includes the range in which the short-circuit section 54D is provided, so the power generation area can be maximized, improving power generation performance. Furthermore, solar cells 264D to 267D on the antenna open end side do not overlap non-connected portion 522D in a plan view, ensuring antenna performance. This makes it possible to expand the power generation area while minimizing the impact on antenna performance.

[0042] [Other embodiments] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, the shapes of the antennas 50, 50B, 50C, and 50D and the solar panels 25, 25B, 25C, and 25D are not limited to being substantially disc-shaped, but may be rectangular or tonneau-shaped in plan view. In other words, the solar cells may have a portion that overlaps with the short-circuit portion of the antenna in plan view, thereby expanding the power generation area. In the above embodiment, the antenna auxiliary member 60 is provided, but the antenna auxiliary member 60 is not necessarily required and may not be provided.

[0043] The solar panel may be provided with a color adjustment section to reduce the color difference between the power-generating section made up of solar cells and the areas other than the power-generating section. For example, the non-power-generating sections 270, 270C, and 270D may be provided with a semiconductor layer, similar to the solar cell section, and then a non-conductive material such as a colored resin layer may be laminated or painted on top of that to provide a color adjustment section. In this case, even if the non-power-generating sections 270, 270C, and 270D are visible through the dial 2, the color difference between the power-generating section and the non-power-generating section will be less noticeable, improving the design.

[0044] 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 one 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 watch should be an appropriate antenna depending on the type of signal to be received, the size of the watch, how it fits in with other components, etc.

[0045] Summary of this disclosure The electronic timepiece disclosed herein comprises a dial, a solar cell arranged on the back side of the dial and having a power generation unit that converts light into electrical energy, a plate-shaped first conductor element arranged on the back side of the solar cell and overlapping the power generation unit in a planar view seen from a direction perpendicular to the surface of the dial, a plate-shaped second conductor element that overlaps the first conductor element in the planar view, and an antenna connected to the outer periphery of the first conductor element and having a short-circuiting portion that short-circuits the first conductor element and the second conductor element, wherein the outer periphery of the first conductor element is composed of a connection portion that connects to the short-circuiting portion and a non-connection portion that is not connected to the short-circuiting portion, at least a portion of the non-connection portion is located outside the power generation unit in the planar view, and the power generation unit has an overlapping portion that overlaps the connection portion. In the electronic timepiece disclosed herein, the outer periphery of the antenna's first conductive element is composed of a connection section that connects to the antenna's short-circuit section and a non-connection section that is not connected to the short-circuit section, and at least a portion of the non-connection section, i.e., the open end of the antenna, is located outside the power generation section, reducing the effect of the power generation section on radio wave reception at the antenna. Furthermore, the solar cell has an overlap section that overlaps with the connection section, allowing the area of ​​the power generation section to be expanded and power generation performance to be improved.

[0046] In the electronic timepiece of the present disclosure, it is preferable that the range in which the power generating section overlaps with the outer periphery of the first conductive element is within ±90 degrees of an imaginary line connecting the center of the dial and the center of the short-circuit section in the plan view. The electronic timepiece disclosed herein allows the overlapping portion to be located within an angular range of up to 180 degrees, including the short-circuited portion, thereby increasing the power generation area. Furthermore, the overlapping portion is located within a ±90-degree range relative to the center of the short-circuited portion, and is not located on the opposite side of the dial center from the short-circuited portion, i.e., on the open end side, thereby minimizing the impact on antenna performance.

[0047] In the electronic timepiece of this disclosure, it is preferable that the entire non-connected portion be located outside the power generation portion in the plan view. According to the electronic timepiece of the present disclosure, the entire non-connected portion is located outside the power generating portion, so that the metal electrodes of the power generating portion overlap only the connected portion in a planar view, and do not overlap the non-connected portion, thereby improving antenna performance.

[0048] In the electronic timepiece disclosed herein, it is preferable that the electronic timepiece has a dielectric auxiliary member that overlaps with the non-connected portion in the planar view, and that in the area that overlaps with the dielectric auxiliary member in the planar view, the non-connected portion is located outside the power generating portion. According to the electronic watch of the present disclosure, a dielectric auxiliary member is placed at the non-connected portion, i.e., the open end side of the antenna where the electric field density is high, and in this area, the non-connected portion is placed outside the power generating unit, so that the dielectric auxiliary member can improve the directivity of the antenna in the zenith direction and prevent a decrease in reception performance due to the influence of the power generating unit.

[0049] In the electronic watch disclosed herein, it is preferable that the watch comprises a circuit board that is electrically connected to the solar cell via a conductive member, a recess is formed on the outer peripheral surface of the antenna, the connection portion and the short-circuit portion are formed to include the recess, and the conductive member is positioned in the recess in the planar view and is provided outside the short-circuit portion. According to the electronic timepiece of the present disclosure, a conductive member is provided outside the short-circuit portion, preventing the conductive member that passes current from the solar cell to the circuit board from affecting the antenna's reception performance, ensuring reception performance. Furthermore, because the conductive member is located in the recess, the electrode terminals of the solar cell that the conductive member contacts can be located within the recess in a plan view. Therefore, it is not necessary to have only the electrode terminals of the solar cell protrude toward the outer periphery, and a disk-shaped solar cell can be used. [Explanation of symbols]

[0050] 1...electronic clock, 1B...electronic clock, 1C...electronic clock, 1D...electronic clock, 2...dial, 3...hand, 10...case, 10B...case, 10C...case, 21...base plate, 25...solar panel, 25B...solar panel, 25C...solar panel, 25D...solar panel, 50...antenna, 50B...antenna, 50C...antenna, 50D...antenna, 51...dielectric, 52...first conductor element, 52B...first conductor element, 52C...first conductor element , 52D...first conductive element, 53...second conductive element, 54...short circuit portion, 54B...short circuit portion, 54C...short circuit portion, 54D...short circuit portion, 56...power supply pin, 60...antenna support member, 70...circuit board, 251...conductive member, 261...solar cell, 261B...solar cell, 261C...solar cell, 261D...solar cell, 262...solar cell, 262B...solar cell, 262C...solar cell, 262D...solar cell, 263...solar cell, 263B... solar cell, 263C... solar cell, 263D... solar cell, 264... solar cell, 264B... solar cell, 264C... solar cell, 264D... solar cell, 265... solar cell, 265B... solar cell, 265C... solar cell, 265D... solar cell, 266... ​​solar cell, 266B... solar cell, 266C... solar cell, 266D... solar cell, 267... solar cell, 2 67B...solar cell, 267C...solar cell, 267D...solar cell, 268...solar cell, 268B...solar cell, 268C...solar cell, 268D...solar cell, 270...non-power-generating portion, 270C...non-power-generating portion, 270D...non-power-generating portion, 502...recess, 521...connecting portion, 521B...connecting portion, 521C...connecting portion, 521D...connecting portion, 522...non-connecting portion, 522B...non-connecting portion, 522C...non-connecting portion, 522D...non-connecting portion.

Claims

1. The dial and a solar cell disposed on the back side of the dial and including a power generating unit that converts light into electrical energy; an antenna arranged on the back side of the solar cell and including a plate-shaped first conductor element that overlaps the power generation unit in a plan view seen from a direction perpendicular to the surface of the dial, a plate-shaped second conductor element that overlaps with the first conductor element in the plan view, and a short-circuiting portion connected to the outer periphery of the first conductor element and short-circuiting the first conductor element and the second conductor element; Equipped with an outer periphery of the first conductive element is composed of a connection portion connected to the short-circuit portion and a non-connection portion not connected to the short-circuit portion, and at least a part of the non-connection portion is located outside the power generation portion in the plan view; The power generating section has an overlapping section that overlaps with the connection section. An electronic watch characterized by:

2. 2. The electronic timepiece according to claim 1, The range in which the power generating portion overlaps with the outer periphery of the first conductive element is within ±90 degrees with respect to an imaginary line connecting the center of the dial and the center of the short-circuit portion in the plan view. An electronic watch characterized by:

3. 2. The electronic timepiece according to claim 1, In the plan view, the entire non-connected portion is located outside the power generation portion. An electronic watch characterized by:

4. 2. The electronic timepiece according to claim 1, a dielectric auxiliary member overlapping the non-connected portion in the plan view; In the area overlapping with the dielectric auxiliary member in the plan view, the non-connected portion is located outside the power generating portion. An electronic watch characterized by:

5. 2. The electronic timepiece according to claim 1, a circuit board that is electrically connected to the solar cell via a conductive member; A recess is formed on the outer circumferential surface of the antenna, the connection portion and the short-circuit portion are formed to include the recess, The conductive member is disposed in the recess in the plan view and is provided outside the short-circuit portion. An electronic watch characterized by:

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