Radio-controlled clock

Abstract

To provide a radio-controlled watch having a metallic dial plate 30, in which a decrease in reception sensitivity is suppressed.SOLUTION: A radio-controlled watch 1 comprises a metallic dial plate 30, an antenna unit 40 provided below the dial plate 30, and a movement 20 at least including a drive mechanism driving the hands. The antenna unit 40 has: an antenna core 41; a coil 42 wound around the antenna core 41; a pair of inside antenna elements 44 magnetically coupled to an end of the antenna core 41, and arranged inside the movement 20; and a pair of outside antenna units 45 magnetically coupled to the end of the antenna core 41, arranged outside the movement 20, and arranged in a manner not to overlap with the dial plate 30 at least in part in plain view.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a radio-controlled watch. [Background technology]

[0002] Patent Document 1 discloses a radio-controlled timepiece equipped with an antenna and a magnetic flux collector. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-89916 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to improve the design of radio-controlled watches, it is advisable to use a metal dial. However, if a metal dial is used in the radio-controlled watch disclosed in Patent Document 1, for example, the radio waves are affected by the metal, resulting in a decrease in reception sensitivity at the antenna.

[0005] The present invention has been made in view of the above-mentioned problems, and its object is to prevent a decrease in reception sensitivity in a radio-controlled timepiece having a metal dial. [Means for solving the problem]

[0006] (1) A radio-controlled watch having a metal dial, an antenna unit provided below the dial, and a movement including at least a drive mechanism for driving the hands, wherein the antenna unit has an antenna core, a coil wound around the antenna core, a pair of inner antenna elements magnetically coupled to the ends of the antenna core and positioned inside the movement, and a pair of outer antenna elements magnetically coupled to the ends of the antenna core and positioned outside the movement so as not to overlap at least a portion of the dial in a planar view.

[0007] (2) In (1), a radio-controlled clock has a pair of connection blocks connected to the ends of the antenna core, the movement has side walls that form its outer shape and includes a base plate that holds the drive mechanism, the inner antenna element is connected to the connection blocks on the inside of the side walls, and the outer antenna element is connected to the connection blocks on the outside of the side walls.

[0008] (3) In the radio-controlled watch according to (1) or (2), the outer antenna element is arranged so as to be separated from the inner antenna element via the side wall.

[0009] (4) A radio-controlled clock in any one of (1) to (3), wherein, in a planar view, the angle formed by a line connecting the center of the dial and the tip of the outer antenna element and a line connecting the center of the dial and the end of the outer antenna element is larger than the angle formed by a line connecting the center of the dial and the tip of the inner antenna element and a line connecting the center of the dial and the end of the inner antenna element.

[0010] (5) A radio-controlled clock in any one of (1) to (3), wherein, in a planar view, the entire inner antenna element overlaps with a fan-shaped area formed by the outer antenna element, a straight line connecting the center of the dial and the tip of the outer antenna element, and a straight line connecting the center of the dial and the end of the outer antenna element.

[0011] (6) A radio-controlled watch according to any one of (1) to (5), wherein the outer antenna element is positioned so as to be spaced apart from the dial in the vertical direction.

[0012] (7) A radio-controlled watch as set forth in any one of (1) to (6), having an outer case including a circular body, the movement having a non-metallic side wall that forms its outer shape and including a base plate that holds the drive mechanism, the external antenna element being provided between the body and the movement, and the distance between the external antenna element and the inner wall of the body being longer than the distance between the external antenna element and the side wall of the movement.

[0013] (8) In any of (1) to (7), the inner antenna element is plate-shaped and is arranged so that its surface faces in the vertical direction, and the outer antenna element is plate-shaped and is arranged so that its surface faces in a direction perpendicular to the vertical direction.

[0014] (9) A radio-controlled watch according to any one of (1) to (8), having a metal annular dial ring that is arranged along the edge of the dial in a planar view, and the dial is arranged so as to be spaced apart radially from the dial ring.

[0015] (10) A radio-controlled watch according to any one of (1) to (8), having a metal annular dial ring that is arranged along the edge of the dial in a planar view, and the dial is arranged so as to be spaced apart from the dial ring in the vertical direction.

[0016] (11) A radio-controlled watch according to any one of (1) to (8), having a non-metallic, annular dial ring arranged along the edge of the dial in a planar view, the dial ring being arranged to overlap the outer antenna element in a planar view.

[0017] (12) A radio-controlled watch according to any one of (1) to (11), which has a solar cell that generates electricity by receiving external light, and the external antenna element is positioned so as not to overlap the solar cell in a planar view.

[0018] (13) In the radio-controlled watch of (12), the solar cell is annular with a diameter larger than that of the dial, and the external antenna element is disposed radially inward of the solar cell.

[0019] (14) A radio-controlled watch according to any one of (1) to (11), which has a solar cell that generates electricity by receiving external light, the solar cell being annular with a diameter larger than the dial, and the external antenna element being located radially outward of the solar cell and with its upper end located at a higher position than the lower end of the solar cell.

[0020] (15) In any of (1) to (14), the movement has a non-metallic side wall that forms its outer shape and includes a base plate that holds the drive mechanism, and the outer antenna element is sheet-shaped and is attached to the side wall so that at least a portion of it is aligned with the extension direction of the inner antenna element.

[0021] (16) A radio-controlled watch according to any one of (1) to (15), having an outer case including an annular bezel, the bezel having a visor portion that protrudes radially inward and at least a portion of which overlaps with the dial in a planar view, and a non-metallic spacer provided between the dial and the visor portion.

[0022] (17) A radio-controlled watch according to any one of (1) to (16), wherein the dial includes a non-metallic outer edge portion, and the external antenna element is arranged so that at least a portion of the outer edge portion overlaps the outer edge portion in a planar view.

[0023] (18) A radio-controlled watch according to (17), further comprising a solar cell that generates electricity by receiving external light, the solar cell being arranged so that at least a portion of the solar cell overlaps the outer edge portion in a plan view.

[0024] (19) A radio-controlled clock according to any one of (1) to (16), which has a non-metallic support body that supports the dial and has a diameter larger than that of the dial, and the external antenna element is arranged so that it does not overlap the dial in a planar view, and at least a portion of it overlaps the support body. [Effects of the Invention]

[0025] According to the above aspects (1) to (19) of the present invention, the reception sensitivity can be reduced in a radio-controlled timepiece having a metal dial. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a plan view showing the case and antenna unit of a radio-controlled timepiece according to a first embodiment. FIG. [Figure 2] FIG. 1 is a plan view showing the exterior case and dial of an electronic timepiece according to a first embodiment. [Figure 3] FIG. 2 is a cross-sectional view showing a cross section taken along the line III-III in FIG. [Figure 4] FIG. 2 is a perspective view showing the antenna unit according to the present embodiment as viewed from below. [Figure 5] FIG. 2 is a cross-sectional perspective view showing a cross section of the antenna unit in the present embodiment. [Figure 6] FIG. 10 is a plan view showing an antenna unit and a solar cell in a second embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a cross section taken along the line VII-VII in FIG. 6. [Figure 8] FIG. 10 is a plan view showing an antenna unit and a solar cell according to a first modified example of the second embodiment. [Figure 9] 9 is a cross-sectional view showing a cross section taken along line IX-IX in FIG. 8. [Figure 10] FIG. 10 is a cross-sectional view showing a part of a cross section of a radio-controlled timepiece according to a second modified example of the second embodiment. [Figure 11] FIG. 10 is a cross-sectional view showing a part of a cross section of a radio-controlled timepiece according to a third modified example of the second embodiment. [Figure 12] FIG. 10 is a cross-sectional view showing a part of a cross section of a radio-controlled timepiece according to a third embodiment. [Figure 13] FIG. 11 is a plan view showing an example of a dial in a third embodiment. [Figure 14] FIG. 11 is a plan view showing the dial in a first modified example of the third embodiment. [Figure 15] FIG. 13 is a cross-sectional view showing an example of the configuration of the dial and support plate in a second modified example of the third embodiment. [Figure 16] FIG. 10 is a cross-sectional view showing a part of a cross section of a radio-controlled timepiece according to a second embodiment, showing an example of an annular solar cell. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings.

[0028] [Radio Clock 1 Overview] First, an overview of a radio-controlled timepiece 1 according to a first embodiment will be described with reference to Figures 1 to 3. Figure 1 is a plan view showing the case and antenna unit of the radio-controlled timepiece according to the first embodiment. Figure 2 is a plan view showing the exterior case and dial of the electronic timepiece according to the first embodiment. Figure 3 is a cross-sectional view showing a cross section taken along the III-III cutting line in Figure 1.

[0029] In Fig. 1, only the case body 11 of the exterior case 10 is shown to show the configuration and arrangement of the antenna unit 40. The dial 30 and the hands that move on the dial 30 are not shown in Fig. 1, but the center O of the dial 30 where the arbor to which the hands are attached is located is shown. Fig. 3 shows a cross section cut along a cutting line that passes through the antenna core 41, the coil 42, and the outer antenna element 45.

[0030] The radio-controlled clock 1 is preferably a wristwatch that has the function of correcting the time based on time information received by the antenna unit 40. The antenna unit 40 is preferably designed to be able to receive long-wave standard waves of, for example, about 30 to 80 KHz. The configuration of the antenna unit 40 will be described in detail later.

[0031] The radio-controlled watch 1 includes at least an exterior case 10, a movement 20, a dial 30, an antenna unit 40, a solar cell 50, and a crystal 90, which constitute the exterior.

[0032] The exterior case 10 includes a case 11, a bezel 12, a dial ring 13, and a back cover 14. The case 11 is annular and houses a movement 20 and other components inside. The bezel 12 holds the crystal 90 and is fixed to the case 11. The dial ring 13 is an annular member that fits along the edge of the dial 30 and is fixed to the bezel 12. The back cover 14 is fixed to the case 11 so as to seal the underside of the case 11.

[0033] The case 11, bezel 12, and back cover 14 are preferably made of metal, such as stainless steel or a titanium alloy, etc. The dial ring 13 is preferably made of metal, such as brass.

[0034] In the first embodiment, the side that is visible to the user wearing the radio-controlled watch 1 is the upper side, and the opposite side is the lower side. That is, in Fig. 3, the side on which the crystal 90 is located is the upper side, and the side on which the back cover 14 is located is the lower side. Note that the shape of the exterior case 10 shown in Figs. 1 to 3 is an example and is not limited to this.

[0035] The movement 20 is constructed by assembling an antenna unit 40, a drive mechanism for driving the hands, a control circuit for the timekeeping function, and the like into a frame called the main plate 21. The movement 20 is located below the dial 30. Note that in Figures 1 and 3, only the outline of the main plate 21 of the movement 20 is shown by a dashed line, and the various parts assembled to the main plate 21 are not shown.

[0036] In the first embodiment, the dial 30 is made of metal. Making the dial 30 out of metal creates a sense of luxury and improves the design. The dial 30 may be made of brass, for example.

[0037] The solar cell 50 is a generator that generates electricity by receiving external light. As shown in FIG. 3, the solar cell 50 is disposed below the dial 30. The solar cell 50 may be disk-shaped. The solar cell 50 may include, for example, a semiconductor layer and a pair of electrode layers sandwiching the semiconductor layer. The semiconductor layer of the solar cell 50 has the function of converting incident light into electricity and may be made of, for example, amorphous silicon. However, this is not limited to this, and other semiconductors such as crystalline silicon may also be used as the semiconductor layer. The pair of electrode layers may be made of, for example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), FTO (Fluorine-doped Tin Oxide), Al (Aluminum), Au (Gold), Ag (Silver), or the like.

[0038] The solar cell 50 may be configured to include a plurality of sector-shaped solar cells arranged adjacent to each other with parting lines interposed therebetween. The solar cell 50 may also have a notch in a part of its circumferential direction.

[0039] In the first embodiment, because the dial 30 is made of metal, external light that enters the dial 30 is reflected without passing through the dial 30. Therefore, as shown in Figure 2, a light-transmitting portion 30h is formed on the dial 30. The light-transmitting portion 30h corresponds to the inset dial, date window, and pivot hole through which the hand shaft is inserted on the dial 30. The inset dial is part of the dial 30 and is a portion that displays functions such as the time using a small hand, an indication of whether it is AM or AM, an indication of the day of the week, and an indication of the remaining charge of the secondary battery.

[0040] The light-transmitting portion 30h may be a through-hole formed in the dial 30. Although not shown, the light-transmitting portion 30h may have a non-metallic member arranged therein that constitutes an in-dial or the like. By forming the light-transmitting portion 30h on the dial 30 in this manner, external light is allowed to enter the solar cell 50 arranged below the dial 30. Note that the shape and arrangement of the light-transmitting portion 30h shown in FIG. 2 are merely an example and are not limited thereto.

[0041] In the first embodiment, the planar shapes of the dial 30 and the main plate 21 are substantially circular. A side wall 21W having a predetermined thickness is provided on at least a portion of the circumferential direction of the main plate 21, which constitutes the outer shape of the main plate 21. At least the side wall 21W of the main plate 21 may be made of a non-metallic material, such as a synthetic resin.

[0042] In the first embodiment, an example is described in which the solar cell 50 is provided, but the present invention is not limited to this, and the radio-controlled watch 1 may be configured without the solar cell 50. In this case, the light-transmitting portion 30h may not be formed on the dial 30.

[0043] [Antenna Unit 40] Next, the configuration of the antenna unit 40 in the first embodiment will be described with reference to Figures 1 to 5. Figure 4 is a perspective view showing the antenna unit in this embodiment as viewed from below. Figure 5 is a cross-sectional perspective view showing a cross section of the antenna unit in this embodiment.

[0044] The antenna unit 40 includes an antenna core 41, a coil 42 wound around the antenna core 41, a pair of connection blocks 43 connected to both ends of the antenna core 41, a pair of inner antenna elements 44 connected to each of the pair of connection blocks 43, and a pair of outer antenna elements 45 connected to each of the pair of connection blocks 43. The antenna core 41 is preferably an antenna winding core around which the coil 42 is wound. The antenna unit 40 may also include a capacitor (not shown) that forms a resonant circuit together with the coil 42. The coil 42 may be formed by winding a linear member multiple times around the antenna core 41, but is shown in a simplified form in each drawing.

[0045] As shown in Fig. 1, the antenna core 41 and the coil 42 are arranged at the 9 o'clock position in a plan view. More specifically, the antenna core 41 is arranged to extend in a direction parallel to the direction connecting the 0 o'clock position and the 6 o'clock position, and the center position of the extension direction of the antenna core 41 approximately coincides with the 9 o'clock position in the circumferential direction. By arranging the antenna core 41 and the coil 42 at the 9 o'clock position, any influence on the arrangement of the crown and winding core (not shown) located at the 3 o'clock position is suppressed.

[0046] The antenna core 41 and the coil 42 are assembled inside the base plate 21 so as to overlap the base plate 21 in a plan view. That is, the antenna core 41 and the coil 42 are disposed inside the side wall 21W of the base plate 21.

[0047] The coil 42 is not wound around either end of the antenna core 41, and both ends of the antenna core 41 are exposed. The lower surfaces 43B of a pair of connection blocks 43 are connected to the either end of the antenna core 41, respectively.

[0048] The pair of connection blocks 43 are arranged symmetrically with respect to the antenna core 41. The pair of connection blocks 43 may be made of a magnetic material such as ferrite and function as receiving terminals of the antenna. In a plan view, the pair of connection blocks 43 are arranged such that the portion to which the inner antenna element 44 is connected overlaps the base plate 21, and the portion to which the outer antenna element 45 is connected does not overlap the base plate 21. In other words, the pair of connection blocks 43 are provided so as to include a portion that is arranged inside and a portion that is arranged outside the side wall 21W of the base plate 21. Note that the side wall 21W of the base plate 21 may be formed with, for example, a pair of openings through which the pair of connection blocks 43 are inserted.

[0049] The inner antenna element 44 and the outer antenna element 45 are preferably both made of a plate-shaped (or strip-shaped) metal and have a magnetic collecting property that attracts magnetic flux. The inner antenna element 44 and the outer antenna element 45 are preferably amorphous thin plates having a thickness of 10 to 100 μm, for example.

[0050] The pair of inner antenna elements 44 have their end portions fixed to the upper surfaces 43U of the pair of connection blocks 43 so as to be magnetically coupled to the connection block 43 and antenna core 41, which are the receiving terminals of the coil 42. By fixing the inner antenna elements 44 to the upper surfaces 43U of the connection blocks 43 in this way, the inner antenna elements 44 are positioned relatively high within the radio-controlled watch 1. This makes it easier for the inner antenna elements 44 to receive radio waves.

[0051] The pair of inner antenna elements 44 are arranged symmetrically with respect to the antenna core 41. At least a portion of the inner antenna elements 44 extends along the side wall 21W of the base plate 21. The inner antenna elements 44 are provided inside the base plate 21 so that the entirety of the inner antenna elements 44 overlaps with the base plate 21 in a plan view. That is, the inner antenna elements 44 are provided inside the side wall 21W of the base plate 21. Note that FIG. 1 shows an example in which a portion of the inner antenna elements 44 extends along the side wall 21W of the base plate 21, but the present invention is not limited to this, and the inner antenna elements 44 may have a shape that entirely follows the side wall 21W of the base plate 21.

[0052] The pair of outer antenna elements 45 have their ends fixed to the side surfaces 43S of the pair of connection blocks 43 so as to be magnetically coupled to the connection blocks 43 and the antenna core 41, which are the receiving terminals of the coil 42. Each of the pair of outer antenna elements 45 has an arc shape in a plan view and is arranged symmetrically around the antenna core 41. The outer antenna elements 45 extend entirely along the side walls 21W of the base plate 21. However, this is not limited thereto, and it is preferable that at least a portion of the outer antenna elements 45 extend along the side walls of the base plate 21. Furthermore, the outer antenna element 45 is provided outside the base plate 21 so as not to overlap the entire outer antenna element 45 with the base plate 21 in a plan view. That is, the outer antenna element 45 is provided outside the side walls 21W of the base plate 21 and separated from the inner antenna element 44 by the side walls 21W.

[0053] Furthermore, the inner antenna element 44 is arranged so that its surface faces the vertical direction. On the other hand, the outer antenna element 45 is arranged so that its surface is perpendicular to the vertical direction. That is, the outer antenna element 45 is arranged so that its surface is perpendicular to the surface of the inner antenna element 44. By arranging the outer antenna element 45, which is arranged on the outside of the base plate 21, in this orientation, it is possible to prevent the antenna unit 40 from becoming large in the radial direction.

[0054] In the antenna unit 40 of this embodiment, the inner antenna element 44 is magnetically coupled to the coil 42, and therefore, when the inner antenna element 44 receives the magnetic force of radio waves, an induced electromotive force is generated in the coil 42. Similarly, the outer antenna element 45 is magnetically coupled to the coil 42, and therefore, when the outer antenna element 45 receives the magnetic force of radio waves, an induced electromotive force is generated in the coil 42. This configuration can improve reception sensitivity compared to a configuration having only one of the inner antenna element 44 and the outer antenna element 45.

[0055] As described above, in the first embodiment, the dial 30 is made of metal. The metal dial 30, which is provided above the antenna unit 40, may affect the reception sensitivity of the antenna unit 40. Therefore, in the first embodiment, a configuration is adopted in which the outer antenna element 45 is positioned so that it does not overlap the dial 30 in a plan view. This makes it easier for the outer antenna element 45 to receive radio waves. It is preferable that the outer antenna element 45 is positioned so that at least a portion of it does not overlap the dial 30 in a plan view.

[0056] In the first embodiment, as shown in FIG. 3 , the outer antenna element 45 is positioned so as to be spaced apart from the case 10 in the vertical and radial directions. Specifically, the outer antenna element 45 is positioned so as to be spaced apart from the bezel 12 and dial ring 13 in the vertical direction and from the back cover 14. The outer antenna element 45 is also positioned so as to be spaced apart from the case 11 in the radial direction. Specifically, the distance L1 between the outer antenna element 45 and the inner wall of the case 11 is longer than the distance L2 between the outer antenna element 45 and the side wall 21W of the movement 20. This configuration makes it possible to suppress the influence of the metal case 10 on the reception sensitivity of the outer antenna element 45.

[0057] 1, the length (arc length) of the outer antenna element 45 in the extension direction is longer than the length (arc length) of the inner antenna element 44 in the extension direction. In other words, in a plan view, the entire inner antenna element 44 overlaps with a fan-shaped area formed by the outer antenna element 45, a straight line connecting the center O of the dial 30 and the tip of the outer antenna element 45, and a straight line connecting the center O of the dial 30 and the end of the outer antenna element 45.

[0058] More specifically, the central angle θ1 of the outer antenna element 45 is made larger than the central angle θ2 of the inner antenna element 44. Here, the central angle θ1 is the angle formed, in a plan view, between a line connecting the center O of the dial 30 to the tip of the outer antenna element 45 and a line connecting the center O of the dial 30 to the end of the outer antenna element 45. Furthermore, the central angle θ2 is the angle formed, in a plan view, between a line connecting the center O of the dial 30 to the tip of the inner antenna element 44 and a line connecting the center O of the dial 30 to the end of the inner antenna element 44.

[0059] [Gap G] Furthermore, this embodiment employs a configuration in which radio waves can enter through a gap G (see FIG. 3) formed between the metal dial 30 and the metal face cover ring 13. Specifically, the diameter of the dial 30 is set to be equal to or smaller than the inner diameter of the face cover ring 13. However, this is not limited to this, and any configuration may be used as long as the gap G is formed at least between the dial 30 and the face cover ring 13. For example, the gap can be formed by making the diameter of the dial 30 larger than the inner diameter of the face cover ring 13 and positioning the dial 30 so that it is spaced apart from the face cover ring 13 in the vertical direction.

[0060] The magnetic flux of radio waves that enters through the gap G between the dial 30 and the dial ring 13 is attracted to the outer antenna element 45, which has a magnetic collecting property. Therefore, after the magnetic flux of radio waves enters through the gap G, it is prevented from being affected by the metal case 11 and bezel 12. As a result, overcurrent loss caused by the fact that the outer case 10 is made of metal is reduced, and a decrease in the reception sensitivity of the antenna unit 40 is suppressed.

[0061] In the first embodiment, an example was shown in which the inner diameter of the dial ring 13 of the exterior case 10 is the smallest, but this is not limited thereto, and the inner diameter of the case 11 or the bezel 12 may be the smallest. In this case, the diameter of the dial 30 should be equal to or smaller than the inner diameter of the case 11 or the bezel 12.

[0062] Furthermore, in the first embodiment, as described above, the central angle θ1 of the outer antenna element 45 is larger than the central angle θ2 of the inner antenna element 44, so that the entire inner antenna element 44 is surrounded by the outer antenna element 45. Therefore, over the entire area in the circumferential direction where the inner antenna element 44 is provided, overcurrent loss caused by the outer case 10 being made of metal is suppressed. Therefore, in addition to the outer antenna element 45, the inner antenna element 44 also easily receives radio waves. As a result, a decrease in the reception sensitivity of the antenna unit 40 is suppressed.

[0063] [others] In the first embodiment, the diameter of the disk-shaped solar cell 50 is smaller than the diameter of the dial 30, and the center of the solar cell 50 coincides with the center O of the dial 30. With this configuration, the pair of outer antenna elements 45 do not overlap the solar cell 50 in a plan view. This prevents the influence of the solar cell 50 from reducing the reception sensitivity of the antenna unit 40.

[0064] [Second embodiment] Next, a radio-controlled timepiece according to a second embodiment will be described with reference to Figs. 6 and 7. Fig. 6 is a plan view showing an antenna unit and a solar cell according to the second embodiment. Fig. 7 is a cross-sectional view showing a cross section taken along the VII-VII line in Fig. 6. In Fig. 7, only the outline of the main plate 21 of the movement 20 is shown by a dashed line, and various components assembled to the main plate 21 are not shown. Note that components having the same functions as those described in the first embodiment are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0065] The radio-controlled watch according to the second embodiment has an annular (ring-shaped) solar cell 150 instead of the disk-shaped solar cell 50 provided in the radio-controlled watch 1 according to the first embodiment described above. The solar cell 150 is a generator that generates electricity by receiving external light. Although not shown, the radio-controlled watch may also have a secondary battery that is attached to the movement 20 and stores the power generated by the solar cell 150.

[0066] In the second embodiment, the exterior case 10 includes a bezel 112, an upper end cover ring 1131, and a lower end cover ring 1132.

[0067] The bezel 112 has an eave portion 112a that protrudes radially inward and is arranged to overlap the solar cell 150 and the dial 30 in a plan view.

[0068] The upper dial ring 1131 is annular and is fixed to the upper surface of the bezel 112. The lower dial ring 1132 is annular and follows the edge of the dial 30, and is provided between the dial 30 and the eaves portion 112a of the bezel 112 in the vertical direction.

[0069] The radio-controlled watch according to the second embodiment also has a ring-shaped middle frame 70 that supports a lower end ring 1132 and a solar cell 150. The lower end ring 1132 is disposed inside the middle frame 70, and the solar cell 150 is disposed outside the middle frame 70. In the second embodiment, the diameter of the solar cell 150 is larger than the diameter of the main plate 21 and the diameter of the lower end ring 1132.

[0070] In the second embodiment, the solar cell 150 is provided radially outward from the outer antenna element 45. Therefore, the solar cell 150 is provided so as not to overlap with the outer antenna element 45 in a plan view.

[0071] In the second embodiment, the lower end cover ring 1132 and the inner frame 70 are preferably made of non-metallic materials. The lower end cover ring 1132 and the inner frame 70 are preferably made of, for example, a light-transmitting resin. This allows the solar cell 150 to receive external light that is incident in a direction oblique to the surface of the dial 30. Furthermore, radio waves pass through the non-metallic lower end cover ring 1132 and enter the interior of the radio-controlled watch. This prevents a decrease in reception sensitivity in the antenna unit 40.

[0072] In the second embodiment, the middle frame 70 supporting the annular solar cell 150 may be extended downward, and the outer antenna element 45 may be fixed to the inner surface of the middle frame 70. For example, the middle frame 70 may be shaped so that its lower end is positioned at least lower than the lower end of the antenna core 41 in the vertical direction. This stabilizes the posture of the outer antenna element 45, and is expected to improve reception sensitivity. Furthermore, in such a configuration in which the middle frame 70 is extended downward, the middle frame 70 may be formed with a recess into which a portion of the connection block 43 is fitted. This stabilizes the posture of the connection block 43, and as a result, the posture of the outer antenna element 45.

[0073] Furthermore, inner frame 70 may be used as a spacer that fills the gap between annular solar cell 150 and outer case 10 in the radial direction, and also fills the gap between movement 20 and outer case 10 in the radial direction. In this case, annular solar cell 150 is preferably supported by inner frame 70. Specifically, an annular groove is formed in inner frame 70, and the lower part of annular solar cell 150 is preferably fitted into this groove.

[0074] 16, the annular solar cell 150 may include an annular power generating unit 150a and a connecting unit 150b electrically connected to the movement 20. As shown in FIG. 16, the connecting unit 150b may include wiring that extends along the sidewall 21W of the movement 20 and bends along the bottom surface of the movement 20, and a flexible substrate (not shown) that supports the wiring. The connecting unit 150b has the shape and arrangement shown in FIG. 16, so that it is not located directly above the inner antenna element 44 and the outer antenna element 45. This prevents the influence of the connecting unit 150b from reducing the reception sensitivity of the antenna unit 40. The connecting unit 150b may be fixed at its tip to the movement 20 with a fastener such as a screw.

[0075] The connection part 150b may be connected to the movement 20 at connection position C shown in Fig. 6, for example. That is, it may be connected to the movement 20 at a position that does not overlap with the inner antenna element 44 and the outer antenna element 45 in a plan view. In a radio-controlled watch that is provided with a crown, a winding core (not shown) that extends from the 3 o'clock position toward the center is disposed inside the movement 20. Therefore, as shown in Fig. 6, the connection part 150b may be connected to the movement 20 at a position that avoids the 3 o'clock position in a plan view.

[0076] [First Modification of Second Embodiment] Next, a first modified example of the second embodiment will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a plan view showing an antenna unit and a solar cell in the first modified example of the second embodiment. Fig. 9 is a cross-sectional view showing a cut surface taken along the IX-IX cutting line in Fig. 8.

[0077] The first modified example of the second embodiment is similar to the second embodiment described with reference to Figures 6 and 7, except for the configuration of the antenna unit. Note that the same reference numerals are used for components having the same functions as those described in the second embodiment, and detailed descriptions thereof will be omitted.

[0078] In a first variant of the second embodiment, the antenna unit 140 includes an antenna core 41, a coil 42 wound around the antenna core 41, a pair of connection blocks 243 respectively connected to both ends of the antenna core 41, a pair of inner antenna elements 44 respectively connected to the pair of connection blocks 243, and a pair of outer antenna elements 245 respectively connected to the pair of connection blocks 243.

[0079] The pair of connection blocks 243 are provided so that their entirety overlaps with the movement 20 in a plan view. In other words, the pair of connection blocks 243 are provided entirely inside the movement 20.

[0080] Each of the pair of outer antenna elements 245 has an extension portion 245a that is connected to the connection block 243 and extends radially outward, and an arc-shaped arc portion 245b that extends along the side wall 21W of the base plate 21. As shown in FIG. 9 , the arc portion 245b preferably has a shape that extends in the vertical direction to just below the eaves portion 112a of the bezel 112. Specifically, the upper end of the arc portion 245b is located higher than the lower end of the solar cell 150, and the upper end of the arc portion 245b is located between the bezel 112 and the solar cell 150 in the radial direction. By employing such outer antenna elements 245, it is possible to enlarge the receiving surface and improve receiving sensitivity.

[0081] [Second Modification of the Second Embodiment] Next, a radio-controlled timepiece according to a second modified example of the second embodiment will be described with reference to Fig. 10. Fig. 10 is a cross-sectional view showing a part of a cross section of a radio-controlled timepiece according to a second modified example of the second embodiment. Note that the same reference numerals are used for components having the same functions as those described in the first and second embodiments, and detailed descriptions thereof will be omitted.

[0082] In a second modification of the second embodiment, the antenna unit 40 has a magnetic sheet 345 as an outer antenna element instead of the outer antenna element 45 made of a metal plate. The magnetic sheet 345 may be, for example, an amorphous magnetic sheet. The magnetic sheet 345 may be attached to the side wall 21W of the base plate 21. Note that the magnetic sheet 345 is not limited to being attached to the side wall 21W, and may be provided at least outside the base plate 21 so as to follow the inner antenna element 44. For example, the middle frame 70 may be shaped so that its lower end is positioned at least below the lower end of the antenna core 41 in the up-down direction, and the magnetic sheet 345 may be attached to the inner surface of the middle frame 70.

[0083] In the second embodiment and the first and second modifications, an annular solar cell 150 whose light-receiving surface faces inward in the radial direction has been described as an example, but the present invention is not limited to this and an annular solar cell whose light-receiving surface faces upward may also be used. Furthermore, the radio-controlled watch may have both the flat solar cell 50 shown in the first embodiment and the annular solar cell 150 shown in the second embodiment.

[0084] [Third Modification of Second Embodiment] Next, a radio-controlled timepiece according to a third modified example of the second embodiment will be described with reference to Fig. 11. Fig. 11 is a cross-sectional view showing a part of a cross section of the radio-controlled timepiece according to the third modified example of the second embodiment. Note that the same reference numerals are used for components having the same functions as those described in the second embodiment, and detailed descriptions thereof will be omitted.

[0085] The radio-controlled watch according to the third modified example of the second embodiment does not have a solar cell 150. By not having a solar cell 150, the dial 30 and movement 20 can be positioned higher. Positioning the movement 20 higher also allows the antenna unit 40 to be positioned higher. Positioning the antenna unit 40 higher can improve reception sensitivity.

[0086] If the dial 30 were placed in contact with the eaves portion 112a of the bezel 112, the dial 30 and the bezel 112 would form a large, integrated metal member, which could have a significant effect on radio waves. Therefore, in the third modified example of the second embodiment, a non-metallic spacer S is provided between the dial 30 and the eaves portion 112a. The spacer S is preferably made of resin or the like. By adopting this configuration, it is possible to prevent radio waves from being affected by the metallic dial 30 and bezel 112. Furthermore, radio waves enter the interior of the radio-controlled watch through the spacer S. As a result, it is possible to prevent a decrease in reception sensitivity in the antenna unit 40.

[0087] [Third embodiment] Next, a radio-controlled timepiece according to a third embodiment will be described with reference to Fig. 12 and Fig. 13. Fig. 12 is a cross-sectional view showing a part of a cross section of a radio-controlled timepiece according to the third embodiment. Fig. 13 is a plan view showing an example of a dial in the third embodiment. Note that the same reference numerals are used for components having the same functions as those described in the first embodiment, and detailed descriptions thereof will be omitted.

[0088] In the third embodiment, the dial 530 includes a non-metallic outer edge 530a. That is, the dial 530 includes a metallic portion and a non-metallic portion surrounding the metallic portion. The outer edge 530a is annular and may be made of, for example, a light-transmitting resin.

[0089] The outer edge portion 530a is provided so as to overlap the outer antenna element 45 in a plan view. The outer edge portion 530a is also provided so as to overlap at least a portion of the inner antenna element 44 in a plan view. The diameter of the outer edge portion 530a is larger than the inner diameter of the dial ring 13. Therefore, the outer edge portion 530a is provided so as to overlap the dial ring 13 in a plan view.

[0090] In the third embodiment, the outer edge 530a is provided in contact with the dial ring 13. In other words, there is no gap between the dial ring 13 and the outer edge 530a. However, because the outer edge 530a is made of a resin that allows radio waves to pass through, radio waves can enter the inside of the radio-controlled watch through the outer edge 530a. With this configuration, even if the dial ring 13 is made of metal, it is possible to suppress a decrease in the reception sensitivity of the antenna unit 40.

[0091] Furthermore, outer edge portion 530a is arranged to overlap flat solar cell 50 in a plan view. Therefore, external light passes through outer edge portion 530a and is incident on solar cell 50. With this configuration, it is possible to ensure the amount of power generated by solar cell 50 even when light-transmitting portion 30h shown in Fig. 2 is not provided on the dial.

[0092] [First Modification of the Third Embodiment] Next, a first modified example of the third embodiment will be described with reference to Fig. 14. Fig. 14 is a plan view showing the dial in the first modified example of the third embodiment. Note that the same reference numerals are used for components having the same functions as those described in the first and third embodiments, and detailed descriptions thereof will be omitted.

[0093] 13 has been described as including non-metallic members around its entire periphery, but in the first modified example of the third embodiment, a configuration is adopted in which at least a non-metallic outer edge 530a is included at the 9 o'clock position where the antenna unit 40 is located. With this configuration, it is possible to suppress a decrease in reception sensitivity in the antenna unit 40 and increase the proportion of the metallic portion of the dial 530.

[0094] [Second Modification of the Third Embodiment] Next, a second modified example of the third embodiment will be described with reference to Fig. 15. Fig. 15 is a cross-sectional view showing an example of the configuration of the dial and support plate in the second modified example of the third embodiment. Note that the same reference numerals are used for components having the same functions as those described in the first and third embodiments, and detailed descriptions thereof will be omitted.

[0095] While the above-described FIG. 12 shows an example in which the metallic and non-metallic portions of dial 530 are on the same layer, this is not limiting and the metallic and non-metallic portions may be on different layers. Specifically, the radio-controlled watch may have a metallic dial 630 and a support plate 730, which is a non-metallic support body that supports dial 630. Support plate 730 may be made of, for example, a light-transmitting resin. In this example, outer antenna element 45 may be arranged so as not to overlap dial 630 but to overlap support plate 730 in a plan view.

[0096] As shown in FIG. 15(a), it is preferable that the diameter of the support plate 730 is larger than the diameter of the dial 630. With such a configuration, it is possible to obtain reception sensitivity equivalent to that of the configuration shown in FIG. 12. Also, as shown in FIG. 15(b), a recess 730r may be formed in the support plate 730, and the dial 630 may be fitted into this recess 730r. Also, as shown in FIG. 15(c), the dial 630 does not have to be positioned at the center of the support plate 730.

[0097] [others] In the above-described embodiments and modifications, the antenna core 41 and the coil 42 are disposed at the 9 o'clock position in a plan view, but this is not limitative. The antenna core 41 and the coil 42 only need to be disposed so as to avoid at least the positions where the crown and the winding core are disposed, and may be disposed at the 6 o'clock position or the 0 o'clock position, for example.

[0098] In the above embodiments and modifications, the connection block 43 is cubic, but this is not limiting, and the side surface 43S of the connection block 43 to which the outer antenna element 45 is fixed may be curved. By making the side surface 43S a curved surface that follows the shape of the outer antenna element 45, the area of ​​the adhesive surface of the outer antenna element 45 to the side surface 43S can be increased. This stabilizes the magnetic coupling between the connection block 43, which is the receiving terminal of the coil 42, and the outer antenna element 45.

[0099] The inside cover ring 13, the upper inside cover ring 1131, and the lower inside cover ring 1132 described in the above embodiments and modifications may be made of a non-metallic resin or the like. By making these inside cover rings non-metallic, it is possible to reduce the effect on the reception sensitivity of the antenna unit 40. When these inside cover rings are made of a non-metallic material, a thin metal film may be provided on the surface of the inside cover ring from the viewpoint of design.

[0100] In the above embodiments and modifications, an analog wristwatch has been used as an example, but the invention is not limited to this and the radio-controlled clock 1 may be a digital wristwatch with a digital display. Also, the radio-controlled clock 1 is not limited to a wristwatch and may be a table clock or a pocket watch. [Explanation of symbols]

[0101] 1 Radio-controlled watch, 10 outer case, 11 body, 12,112 bezel, 112a visor, 13 face cover ring, 1131 upper face cover ring, 1132 lower face cover ring, 14 back cover, 20 movement, 21 main plate, 21W side wall, 30,530,630,730 dial, 40 antenna unit, 41 antenna core, 42 coil, 43,243 connection block, 44 inner antenna element, 45,245 outer antenna element, 50,150 solar cell, 70 center frame, 90 crystal.

Claims

1. Metal dial and an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and a pair of connection blocks connected to ends of the antenna core; the movement has a side wall that defines its outer shape and includes a main plate that holds the drive mechanism; the inner antenna element is connected to the connection block inside the side wall, and the outer antenna element is connected to the connection block outside the side wall. Radio-controlled clock.

2. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and The outer antenna element is provided so as to be spaced apart from the inner antenna element via a side wall that constitutes the outer shape of the movement. Radio-controlled clock.

3. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and In a plan view, the angle formed by a line connecting the center of the dial and the tip of the outer antenna element and a line connecting the center of the dial and the end of the outer antenna element is larger than the angle formed by a line connecting the center of the dial and the tip of the inner antenna element and a line connecting the center of the dial and the end of the inner antenna element. Radio-controlled clock.

4. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; an outer case including a circular body; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and the movement has a non-metallic side wall that defines its outer shape, and includes a main plate that holds the drive mechanism; the external antenna element is provided between the case and the movement; the distance between the outer antenna element and the inner wall of the case is longer than the distance between the outer antenna element and the side wall of the movement; Radio-controlled clock.

5. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and The watch further includes a metal ring having an annular shape and arranged along the edge of the dial in a plan view, The dial is disposed so as to be spaced apart from the dial ring in the radial direction. Radio-controlled clock.

6. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and The watch further includes a metal ring having an annular shape and arranged along the edge of the dial in a plan view, The dial is disposed so as to be spaced apart from the dial ring in the up-down direction. Radio-controlled clock.

7. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and The watch further includes a non-metallic annular face cover ring that is arranged along the edge of the dial in a plan view, The dial ring is provided so as to overlap the outer antenna element in a plan view. Radio-controlled clock.

8. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; A solar cell that generates electricity by receiving external light, and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and The outer antenna element is arranged so as not to overlap with the solar cell in a plan view. Radio-controlled clock.

9. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; A solar cell that generates electricity by receiving external light, and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and the solar cell is annular and has a diameter larger than that of the dial, The outer antenna element is provided radially outward of the solar cell, and an upper end of the outer antenna element is provided at a position higher than a lower end of the solar cell. Radio-controlled clock.

10. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and the movement has a non-metallic side wall that defines its outer shape, and includes a main plate that holds the drive mechanism; The outer antenna element is in a sheet shape and is attached to the side wall so that at least a portion of the outer antenna element extends in the direction in which the inner antenna element extends. Radio-controlled clock.

11. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; an outer case including an annular bezel; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and the bezel has a visor portion that protrudes radially inward and at least a portion of which overlaps with the dial in a plan view; A non-metallic spacer is provided between the dial and the eaves. Radio-controlled clock.

12. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and the dial includes a non-metallic outer edge; The outer antenna element is provided so that at least a portion of the outer antenna element overlaps the outer edge portion in a plan view. Radio-controlled clock.

13. A metal dial plate; an antenna unit provided below the dial; a movement including at least a drive mechanism for driving the hands; and The antenna unit is An antenna core; a coil wound around the antenna core; a pair of inner antenna elements magnetically coupled to ends of the antenna core and disposed inside the movement; a pair of outer antenna elements magnetically coupled to ends of the antenna core, disposed outside the movement, and positioned so as not to overlap at least a portion of the dial in a plan view; and a non-metallic support member that supports the dial and has a diameter larger than that of the dial; the outer antenna element is provided so as not to overlap the dial and so as to overlap at least a portion of the support in a plan view; Radio-controlled clock.

14. In a plan view, the entire inner antenna element overlaps with a sector-shaped area formed by the outer antenna element, a straight line connecting the center of the dial and the tip of the outer antenna element, and a straight line connecting the center of the dial and the end of the outer antenna element. The radio-controlled watch according to any one of claims 1 to 13.

15. The outer antenna element is disposed so as to be spaced apart from the dial in the vertical direction. The radio-controlled watch according to any one of claims 1 to 13.

16. The inner antenna element is plate-shaped and is arranged so that its surface faces in the up and down directions, The outer antenna element is plate-shaped and is arranged so that its surface faces in a direction perpendicular to the up-down direction. The radio-controlled watch according to any one of claims 1 to 13.

17. the solar cell is annular and has a diameter larger than that of the dial, The outer antenna element is provided radially inward of the solar cell.

9. The radio-controlled watch according to claim 8.

18. It has a solar cell that generates electricity by receiving external light, The solar cell is provided so that at least a portion of the solar cell overlaps the outer edge portion in a plan view.

13. The radio-controlled watch according to claim 12.

Images