JP6456030B2 - Radio wave watch - Google Patents

Description

  The present invention relates to a radio-controlled wristwatch that receives radio waves using a planar antenna.

  There is known a radio wristwatch that receives a radio wave transmitted from a time information source and corrects the time using time information included in the radio wave. Among such radio watches, for example, satellite radio watches that receive radio waves from GPS (Global Positioning System) satellites use planar antennas such as patch antennas to receive radio waves ( For example, see Patent Document 1).

JP2013-40793A

  In the radio wave wrist watch as described above, it is desired to improve the characteristics (gain) of the planar antenna in order to increase the radio wave reception sensitivity. The present invention has been made in consideration of such problems, and one of its purposes is to provide a radio-controlled wristwatch capable of improving the characteristics of a planar antenna.

  The invention disclosed in the present application in order to solve the above problems has various aspects, and the outline of typical aspects of the aspects is as follows.

  (1) A planar antenna that receives radio waves including time information, a planar antenna substrate on which the planar antenna is mounted, and a back cover formed of a conductive member, the ground of the planar antenna substrate and the back A radio-controlled wristwatch characterized in that a lid is electrically connected via a contact provided in a region of the back lid that overlaps the planar antenna in plan view.

  (2) In (1), a conductive member including a spring that biases the planar antenna substrate toward the opposite side of the back cover is disposed between the planar antenna substrate and the back cover, The radio-controlled wristwatch, wherein the conductive member is electrically connected to the ground of the planar antenna substrate, and the back cover and the spring are electrically connected via the contact.

  (3) In (1) or (2), the ground of the planar antenna substrate is electrically connected to the back cover through a plurality of contacts provided in the region. Watches.

  According to the side surface of (1) above, the gain of the planar antenna can be improved by ensuring that the region overlapping the planar antenna in the plan view of the back cover has the same potential as the ground of the planar antenna substrate.

  According to the side surface of said (2), the ground and back cover of a planar antenna board | substrate can be electrically connected using the member which fixes a planar antenna board | substrate.

  According to the side surface of (3) above, the ground of the planar antenna substrate and the back cover can be electrically connected more reliably.

It is a top view which shows the external appearance of the radio wave wristwatch which concerns on embodiment of this invention. It is the top view which looked at the movement accommodated in the case of a radio-wave wristwatch from the back side. It is a schematic exploded perspective view of a movement. It is sectional drawing which shows the cross section containing the battery of a movement.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a plan view showing a radio-controlled wristwatch 100 according to an embodiment of the present invention. The figure shows a case 1 constituting a case (exterior) of the radio-controlled wristwatch 100, a dial 2 arranged in the case 1, and an hour hand 3, a minute hand 4 and a second hand 5 which are hands indicating time. Further, a crown 6 and a push button 7 for a user to perform various operations are arranged on the side surface of the trunk 1 on the 3 o'clock side. A band fixing portion 8 for fixing the band extends from the side surface of the trunk 1 on the 12 o'clock side and the 6 o'clock side.

  In addition, the design of the radio-controlled wristwatch 100 shown in the figure is an example. In addition to those shown here, for example, the body 1 may be square instead of round, and the presence / absence, number, and arrangement of the push buttons 7 are arbitrary. Further, in the present embodiment, the hands are three hands of the hour hand 3, the minute hand 4, and the second hand 5, but the present invention is not limited to this, and even if the second hand 5 is omitted, the day of the week, the time zone or the presence / absence of summer time, the radio wave The reception status, remaining battery level, pointers for various displays, date display, and the like may be added. Further, the case of the radio-controlled wristwatch 100 includes a case 1 and a back cover 9 that does not appear in FIG. Both the body 1 and the back cover 9 may be made of metal, or the body 1 may be made of a material other than metal, for example, ceramic. In any case, the back cover 9 constituting the case in the present embodiment is made of a conductive member such as metal.

  In this specification, the term radio-controlled wristwatch is used to indicate a radio-controlled timepiece and a wristwatch. In this embodiment, the radio-controlled wristwatch 100 receives the satellite signal from a satellite (such as a GPS satellite) that transmits a satellite signal including information related to the date and time, and information related to the date and time included in the received satellite signal, that is, Based on the reference time information, it is assumed that the internal time, which is the time information held in the wristwatch, is corrected. The radio wave signal received by the radio wristwatch 100 is not limited to a satellite signal, and is not particularly limited as long as it is a signal including reference time information. However, since the radio wave signal is preferably received by the planar antenna 11 described later, it is preferably a high frequency signal from a short wave to a very high frequency.

  In the radio-controlled wristwatch 100, a windshield made of a transparent material such as glass is attached to the case 1 so as to cover the dial 2. A back cover 9 is attached to the body 1 on the opposite side of the windshield. In the present specification, hereinafter, the direction in which the windshield of the radio-controlled wristwatch 100 is arranged (front side in FIG. 1) is referred to as the front side, and the direction in which the back cover 9 is arranged (back direction in FIG. 1) is referred to as the back side.

  On the back side of the dial 2, the battery 10 and the planar antenna 11 are arranged so as not to overlap in a plan view. In the present embodiment, the battery 10 is a disc-shaped lithium secondary battery, and accumulates electric power generated by a solar battery provided on the back side of the dial 2. Therefore, the dial 2 is transparent or translucent. In addition, the kind of battery 10 is not specifically limited, A primary battery may be sufficient. In that case, a solar cell may not be provided and the dial 2 may not have transparency. Moreover, in this embodiment, the back side surface and side surface of the battery 10 constitute a positive electrode, and the front side surface constitutes a negative electrode. The potential of the positive electrode of the battery 10 becomes the reference potential of the radio-controlled wristwatch 100, that is, the so-called ground potential.

  In the present embodiment, the planar antenna 11 is a patch antenna having a substantially rectangular flat plate shape, and is arranged near the 12 o'clock direction on the back side of the dial 2 in parallel with the dial 2 and the back cover 9. The radio wave signal received by the planar antenna 11 is a satellite signal from a GPS satellite and is a very high frequency wave. In the present embodiment, the feeding electrode of the planar antenna 11 is disposed on the back side, and is connected to the electrode provided on the side surface on the 12 o'clock side to constitute a strip electrode. This feeding electrode detects a current flowing in the detection target region 11a along the left and right side surfaces of the receiving surface arranged on the upper surface of the planar antenna 11. Specifically, as shown in FIG. 1, the detection target region 11 a is formed along the 3 o'clock side and the 9 o'clock side of the upper surface of the planar antenna 11. This detection target area 11a is mainly used for reception of radio waves by the planar antenna 11.

  FIG. 2 is a plan view of the movement 101 housed in the case of the radio-controlled wristwatch 100 as viewed from the back side. The movement 101 has a configuration in which each member is assembled to a ground plane 12 made of a substantially circular insulating material serving as a support frame. In FIG. 2, the winding stem 13 to which the crown 6 is attached so as to jump out from the movement 101 in the left direction in the drawing can be seen. Accordingly, in the figure, the left direction corresponds to the 3 o'clock direction in FIG. 1, the right direction is the 9 o'clock direction, the upper direction is the 12 o'clock direction, and the lower direction is the 6 o'clock direction.

  As shown in FIG. 2, in the 6 o'clock direction on the back side of the movement 101, a battery retainer 14 made of a circular conductive member is disposed so as to cover the battery 10. Further, in a region excluding the battery retainer 14 on the back side of the movement 101, a magnetic resistant plate 15 made of a substantially crescent-shaped conductive member is disposed. The battery retainer 14 is in contact with the positive electrode on the back side of the battery 10 and is electrically connected. Further, the battery retainer 14 is screwed to the magnetic resistant plate 15 by a screw 14 a and is electrically connected to the magnetic resistant plate 15. As will be described later, the ground of the planar antenna substrate 16 on which the planar antenna 11 is mounted is also electrically connected to the positive electrode of the battery 10. As a result, the ground of the planar antenna substrate 16 is electrically connected to the antimagnetic plate 15.

  Further, a spring 15a formed by an elastic tongue-shaped protrusion is disposed on the end of the magnetically resistant plate 15 opposite to the battery retainer 14 (that is, in the 12 o'clock direction) so as to protrude to the back side. In a state where the movement 101 is housed in the case, the contact C at the tip of the spring 15a comes into contact with the front surface of the back cover 9, whereby the antimagnetic plate 15 and the back cover 9 are conducted. Further, the antimagnetic plate 15 is biased to the front side by the elasticity of the spring 15a, and each member inside the movement 101 including the planar antenna substrate 16 is pressed and fixed to the ground plate 12 side.

  In this way, the ground of the planar antenna substrate 16 is electrically connected to the antimagnetic plate 15, and the antimagnetic plate 15 is electrically connected to the back cover 9 via the contact C, whereby the back cover 9 is connected to the ground of the flat antenna 16. It is electrically connected and the back cover 9 serves as a ground. As described above, by using the back cover 9 which is a large conductive member as compared with other members as a ground, a sufficient ground for the planar antenna 11 can be secured.

  In FIG. 2, the position of the planar antenna 11 is indicated by a broken line. As can be seen from the figure, the tip of the spring 15a (that is, the contact C between the magnetic-resistant plate 15 and the back cover 9) is located in a region overlapping the planar antenna 11 in plan view. That is, the contact C is in a region overlapping the planar antenna 11 when viewed from the direction perpendicular to the back cover 9 and the dial 2. Thereby, especially the area | region which opposes the planar antenna 11 of the back cover 9 can be earth | grounded reliably, and it can maintain at reference potential. As a result of research, the inventors of the present application have found that the gain of the planar antenna 11 can be improved by arranging the contact C in a region overlapping the planar antenna 11 in plan view as shown in FIG. This is because if a contact point is provided at a position away from the planar antenna 11, the potential distribution on the back cover 9 tends to be asymmetric with respect to the planar antenna 11, which adversely affects the reception characteristics of the two detection target regions 11 a of the planar antenna 11. It is because it exerts. Therefore, the gain of the planar antenna 11 can be expected to be improved by providing the contact C in a region that is near the same distance from the two detection target regions 11a in the region overlapping the planar antenna 11 in a plan view of the back cover 9. Here, a center line parallel to the detection target region 11 a of the planar antenna 11 (that is, a center line in the left-right direction) is set as a center line L. In FIG. 2, the center line L is indicated by a one-dot chain line. At this time, it is more preferable to arrange the contact C at a position closer to the center line L than to the distance to the left and right side surfaces of the planar antenna 11.

  Here, only one spring 15a is provided on the magnetic-resistant plate 15. For this reason, there is only one contact C between the magnetic plate 15 and the back cover 9. However, the present invention is not limited to this, and a plurality of contacts C may be provided in a region overlapping the planar antenna 11 of the back cover 9. For example, a plurality of springs 15 a may be formed side by side on the magnetic-resistant plate 15, and the tips of the plurality of springs 15 a may be in contact with the back cover 9. In this way, the ground of the planar antenna substrate 16 and the back cover 9 can be electrically connected more reliably. Further, it is more preferable that the plurality of contacts C formed by the plurality of springs 15a are provided so as to be symmetric with respect to the center line L.

  Next, an electrical connection path between the planar antenna substrate 16 and the antimagnetic plate 15 will be described with reference to FIGS. 3 and 4.

  FIG. 3 is a schematic exploded perspective view of the movement 101. In the figure, the upward direction is the back side, and the downward direction is the front side. 3 shows a state in which a driving component such as a motor is accommodated with respect to the base plate 12, and the clock circuit board 21 and the circuit pressing plate 22 are arranged on top of each other. The clock circuit board 21 is a board on which various electronic components such as a control circuit that realizes a timekeeping function are mounted. A rectangular notch is provided at the 12 o'clock position of the timepiece circuit board 21 for accommodating the substantially rectangular planar antenna 11. The circuit holding plate 22 is disposed so as to be electrically connected to the timepiece circuit board 21 and fixes the timepiece circuit board 21 to the ground plate 12 side. Further, a planar antenna substrate 16 is disposed on the back side. The planar antenna 11 is disposed at a position on the front side of the planar antenna substrate 16 on the 12:00 side. A high-frequency circuit for reception by the planar antenna 11 is also mounted on the planar antenna substrate 16. A circular notch is provided at a position of the planar antenna substrate 16 at the 6 o'clock side, that is, at a position opposite to the rectangular notch of the timepiece circuit board 21, and accommodates the substantially circular battery 10. ing. On the back side of the battery 10 and the planar antenna substrate 16, the above-described battery retainer 14 and magnetic-resistant plate 15 are disposed, respectively. Each member constituting the movement 101 described above is fixed by inserting a columnar columnar member 23 into a hole provided in each member and screwing.

  FIG. 4 is a cross-sectional view of the movement 101 viewed from 6 o'clock with the back side facing upward. That is, the front side of the page corresponds to the 6 o'clock direction, the back direction corresponds to the 12 o'clock direction, the right direction corresponds to the 9 o'clock direction, and the left direction corresponds to the 3 o'clock direction. FIG. 4 shows a cross section of the movement 101 passing through the battery 10, but is a schematic cross sectional view showing the positional relationship of each member constituting the movement 101. Therefore, members that are actually offset in the depth direction of the drawing may be shown on the same plane in FIG.

  As shown in FIG. 3, the magnetic-resistant plate 15 and the planar antenna substrate 16 are disposed so as to overlap each other, but are not directly conducted and are insulated from each other. Instead, as shown in FIG. 4, the ground of the planar antenna substrate 16 is connected to the ground of the timepiece circuit board 21 via a conductive rubber 21 a attached to the timepiece circuit board 21. Note that the ground of the planar antenna substrate 16 and the ground of the timepiece circuit substrate 21 are conducted via a columnar member 23 formed of a conductive member such as a metal instead of or in addition to the conductive rubber 21a. It is good as well. The ground of the timepiece circuit board 21 is electrically connected to a circuit pressing plate 22 made of a conductive member. Further, the circuit holding plate 22 is formed with a connection terminal portion 22 a that protrudes so as to come into contact with the positive electrode on the side surface of the battery 10. The circuit holding plate 22 is electrically connected to the positive electrode of the battery 10 through the connection terminal portion 22a. Further, as described above, the positive electrode on the back side of the battery 10 is electrically connected to the back cover 9 via the battery retainer 14 and the magnetically resistant plate 15. As a result, the ground of the planar antenna substrate 16 is electrically connected to the back cover 9 and constitutes the reference potential of the radio-controlled wristwatch 100 as a whole.

  According to the radio wave wristwatch 100 according to the present embodiment described above, the contact C on the back cover 9 that electrically connects the ground of the flat antenna substrate 16 and the back cover 9 is in a region overlapping the flat antenna 11 in plan view. By disposing, the region of the back cover 9 that overlaps with the planar antenna 11 can be reliably grounded, whereby the gain of the planar antenna 11 can be improved.

  Note that the specific configuration shown in the embodiment described above is an exemplification, and those skilled in the art may make various modifications. For example, the shape and number of each member or part thereof may be changed as appropriate, and need not be the same as illustrated. For example, the electrical path shown in FIGS. 3 and 4 is merely an example, and the ground of the planar antenna substrate 16 may be electrically connected to the back cover 9 by another path. For example, as in the electrical connection between the planar antenna substrate 16 and the timepiece circuit substrate 21 described above, each member in the movement 101 such as the anti-magnetic plate 15 and the circuit pressing plate 22 is a columnar member made of a conductive member. 23 may be electrically connected.

  1 body, 2 dial, 3 hour hand, 4 minute hand, 5 second hand, 6 crown, 7 push button, 8 band fixing part, 9 back cover, 10 battery, 11 planar antenna, 11a detection target area, 12 ground plate, 13 winding true , 14 Battery holder, 14a Screw, 15 Magnetic plate, 15a Spring, 16 Planar antenna board, 21 Clock circuit board, 21a Conductive rubber, 22 Circuit holding board, 22a Connection terminal part, 23 Columnar member, 100 Radio wave watch, 101 Movement.

Claims (5)

And Rua antenna to receive the radio waves including time information,
And Rua container board before Kia antenna is mounted,
A back cover formed of a conductive member;
Battery,
With
Before and Kia antenna ground of the substrate and the back cover, it said back cover are electrically connected via the contacts provided in a region overlapping with the previous Kia antenna in plan view,
A radio-controlled wristwatch, wherein the battery and the antenna are arranged so as not to overlap each other in plan view . Having a trunk constituting the exterior of the radio-controlled wristwatch;
The contact is provided closer to the body than the battery in the region.
The radio-controlled wristwatch according to claim 1. Before Kia between antenna substrate and with the back cover, the conductive member disposed with a spring for urging the front Kia antenna substrate to the back cover opposite side,
The conductive member is connected before Kia antenna board ground electrically,
The radio-controlled wristwatch according to claim 1 or 2, wherein the back cover and the spring are electrically connected via the contact point. Ground before Kia antenna substrate according to any one of claims 1 to 3, characterized in that via a plurality of contacts provided in said region is electrically connected to the back cover of the wristwatch. The antenna is arranged in a region on one side of a bisector that passes through the center of the radio-controlled wristwatch.
The radio-controlled wristwatch according to any one of claims 1 to 4.

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