JP2018084494A - Electronic watch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic watch including an antenna allowing its size to be reduced and allowing deteriorated reception sensitivity to be prevented.SOLUTION: An electronic watch 10 includes: a cylindrical exterior case 31; a dial plate 11 housed in the exterior case 31; a rear lid 34 for blocking one opening of the exterior case 31; a battery 130 disposed closer to the rear lid 34 side than the dial plate 11 inside the exterior case 31; and an antenna body 110 disposed inside the exterior case 31 and including a substrate formed with an annular dielectric and an antenna electrode installed on the substrate. In plan view viewed in a direction parallel to an in-plane direction of the dial plate 11, the substrate overlaps with at least part of the dial plate 11 and at least part of the battery 130.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electronic timepiece having an antenna.

  In recent years, an analog electronic timepiece has been developed that receives radio waves wirelessly transmitted from a position information satellite such as a GPS (Global Positioning System) satellite and displays the time.

Patent Documents 1, 2, and 3 describe an electronic timepiece (hereinafter referred to as “electronic timepiece with a ring antenna”) in which an annular antenna is employed as an antenna for receiving radio waves.
In these electronic timepieces with ring antennas, the base on which the antenna electrode of the annular antenna is installed is formed of a dielectric, thereby shortening the wavelength of the radio wave received by the antenna electrode, and reducing the shortened wavelength with the antenna electrode. Receive. For this reason, the antenna electrode is downsized.

JP 2013-64723 A JP 2013-181918 A JP 2011-21929 A

Further miniaturization is required for electronic watches with ring antennas. In order to meet this requirement, it is conceivable to reduce the diameter of the annular antenna or battery and the diameter of the entire electronic timepiece.
However, when the diameter of the annular antenna having the antenna electrode having a length corresponding to the reception wavelength is reduced, there is a problem that the reception sensitivity is reduced. Further, when the battery diameter is reduced, the battery thickness is increased in order to secure the battery capacity, the distance between the battery and the antenna electrode is reduced, and the reception sensitivity is reduced.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to reduce the diameter of the electronic timepiece and to suppress the reduction in reception sensitivity.

One aspect of the electronic timepiece according to the present invention includes a cylindrical outer case, a dial accommodated in the outer case, a back cover that closes one opening of the outer case, and the character inside the outer case. A battery disposed on the back cover side of the plate, an antenna body disposed on the inner side of the exterior case, and including a base formed of an annular dielectric and an antenna electrode placed on the base. In addition, in a plan view as viewed from a direction parallel to the in-plane direction of the dial, the base body overlaps at least a part of the dial and at least a part of the battery.
According to this aspect, the substrate formed of the annular dielectric material overlaps at least a part of the dial and at least a part of the battery in a plan view as viewed from a direction parallel to the in-plane direction of the dial.
With this configuration, the base can be elongated in the normal direction of the dial plate, so that the volume of the base can be increased and the effective dielectric constant for the antenna electrode can be improved. For this reason, it is possible to suppress a reduction in reception sensitivity while reducing the diameter of the antenna and hence the diameter of the electronic timepiece. In addition, since the volume of the dielectric disposed between the battery and the antenna electrode increases, the electrical length between the battery and the antenna electrode can be increased compared to the case where air is interposed between the battery and the antenna electrode, It can suppress that reception sensitivity falls with a battery.
Here, the “annular shape” includes a circular shape or a substantially square shape, and includes an open ring shape (for example, C type) that is partially opened, and a closed ring shape (for example, O type) that is partially closed.

In one aspect of the electronic timepiece described above, the electronic timepiece includes a circuit board disposed inside the exterior case and closer to the back cover than the dial, and in the plan view, at least a part of the battery includes the circuit board. It is desirable that a part of the base body overlaps at least a part of the part of the battery located closer to the back cover than the circuit board.
According to this aspect, in a plan view seen from a direction parallel to the in-plane direction of the dial, a part of the base body overlaps with a part of the battery part located on the back cover side with respect to the circuit board.
For this reason, the base can be made longer in the normal direction of the dial plate and the volume of the base can be increased compared with the case where the base and the battery portion located on the back cover side of the circuit board do not overlap in the plan view. It becomes possible. Therefore, the diameter of the electronic timepiece can be further reduced.
Further, by positioning at least a part of the battery on the back cover side of the circuit board, a space can be provided between the circuit board and the back cover. For example, an element is disposed only on the back cover side of the circuit board. The elements can be arranged on both sides of the circuit board. Thus, the electronic timepiece can be thinned by effectively utilizing the space between the circuit board and the back cover.

In one aspect of the above-described electronic timepiece, the electronic timepiece includes a ground plate disposed on the back cover side of the dial inside the exterior case, and a protrusion projecting toward the exterior case side is provided on an outer periphery of the ground plate. It is desirable that the base be provided with a notch that contacts the protrusion.
According to this aspect, the base can be positioned with reference to the protruding portion of the ground plane.

In one aspect of the electronic timepiece described above, it is desirable that a feed element that is electrically connected to the antenna electrode and fed with a predetermined potential is provided in the notch.
According to this aspect, it is possible to feed power to the antenna body through the notch.

In one aspect of the electronic timepiece described above, it is preferable that the protruding portion is provided with a protruding portion that comes into contact with the exterior case.
According to this aspect, the ground plate for positioning the antenna body is in contact with the exterior case at the protruding portion. For this reason, it becomes possible to fix the position of the ground plane and the antenna body with respect to the exterior case.

In one aspect of the electronic timepiece described above, it is preferable that an operation member is included, and the notch is provided at a location facing the operation member.
According to this aspect, it is possible to suppress the operation on the operation member from being restricted by the base body.

1 is an overall view of a GPS including an electronic timepiece 10 according to the present embodiment. 1 is a plan view showing an electronic timepiece 10. 1 is a cross-sectional view of an electronic timepiece 10. 2 is a perspective view of an antenna body 110. FIG. FIG. 4 is a diagram showing a positional relationship among a base body 110a, a secondary battery 130, a circuit board 120, and a dial plate 11 in a plan view viewed from a direction A parallel to the in-plane direction of the display surface 11a. FIG. 5 is a diagram illustrating a power feeding mechanism of an antenna body 110. 2 is a block diagram showing a circuit configuration of the electronic timepiece 10. FIG. It is a figure showing electronic timepiece 10A of a 2nd embodiment of the present invention. It is the figure which showed the electronic timepiece 10B of 3rd Embodiment of this invention. It is the figure which showed an example of the antenna fixing | fixed part 125a3 and the engaging part 110a1. It is sectional drawing of the antenna fixing | fixed part 125a3 and the engaging part 110a1.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the size and scale of each part are appropriately different from the actual ones. The embodiments described below are preferred specific examples of the present invention. For this reason, the technically preferable various restrictions are attached | subjected to this embodiment. However, the scope of the present invention is not limited to these forms unless otherwise specified in the following description.

<First Embodiment>
FIG. 1 is a general view of a GPS including an antenna built-in electronic timepiece (hereinafter simply referred to as “electronic timepiece”) 10 according to the present embodiment.

  The electronic timepiece 10 is a wristwatch that receives radio waves wirelessly transmitted from the GPS satellite 8 and corrects the time measured by an internal timepiece (RTC 152 described later). The electronic timepiece 10 displays time and the like on a surface (hereinafter referred to as “front surface”) opposite to a surface that contacts the arm (hereinafter referred to as “back surface”). The GPS satellite 8 is a navigation satellite that orbits a predetermined orbit in the sky above the earth. The GPS satellite 8 transmits a 1.57542 GHz radio wave (L1 wave) on which the navigation message is superimposed to the ground. In the following description, the 1.57542 GHz radio wave on which the navigation message is superimposed is referred to as a “satellite signal”. The satellite signal is a right-handed circularly polarized wave.

  Currently, there are about 31 GPS satellites 8 (only four are shown in FIG. 1). In order to identify which GPS satellite 8 the satellite signal is transmitted from, each GPS satellite 8 superimposes a unique pattern of 1023 chips (1 ms period) called a C / A code (Coarse / Acquisition Code) on the satellite signal. Each chip is either “+1” or “−1”. For this reason, the C / A code looks like a random pattern.

  The GPS satellite 8 is equipped with an atomic clock. The satellite signal (navigation message) includes extremely accurate GPS time information measured by an atomic clock. A slight time error of the atomic clock mounted on each GPS satellite 8 is measured by the control segment on the ground. The satellite signal (navigation message) also includes a time correction parameter for correcting the time error. The electronic timepiece 10 receives a satellite signal transmitted from one GPS satellite 8, and at an accurate time (time information) obtained using GPS time information and time correction parameters included in the satellite signal, Set the time of the internal clock.

The satellite signal includes orbit information indicating the position of the GPS satellite 8 on the orbit. The electronic timepiece 10 can perform positioning calculation using GPS time information and orbit information.
The positioning calculation is performed on the assumption that a certain amount of error is included in the time measured by the internal clock of the electronic timepiece 10. That is, in addition to the x, y, and z parameters for specifying the three-dimensional position of the electronic timepiece 10, the time error is also an unknown number. Therefore, the electronic timepiece 10 generally receives satellite signals respectively transmitted from four or more GPS satellites 8, performs positioning calculation using GPS time information and orbit information included in the satellite signals, Find location information for your current location.

FIG. 2 is a plan view showing the electronic timepiece 10. FIG. 3 is a cross-sectional view of the electronic timepiece 10 (a cross-sectional view taken along a line from the 7 o'clock position of the dial plate 11 through the pointer shaft 25 to the 3 o'clock position of the dial plate 11).
The electronic timepiece 10 includes a cylindrical outer case 31, a bezel 32, a light-transmitting cover glass 33, and a back cover 34. Of the two openings of the outer case 31, the opening on the front surface side (one opening) is closed with the cover glass 33 through the bezel 32, and the opening on the back surface side (the opening on the opposite side to the one opening). ) Is closed by the back cover 34. The exterior case 31, the bezel 32, and the back cover 34 are made of a metal such as stainless steel, titanium, aluminum, or brass.

  On the inner peripheral side of the bezel 32, a ring-shaped dial ring 40 made of plastic is disposed. As shown in FIG. 2, the dial ring 40 has a time difference display unit 45 representing a time difference from Coordinated Universal Time (hereinafter referred to as “UTC”) expressed by numerals and symbols other than numerals. .

Here, UTC, time difference, standard time, and time zone will be described.
A time zone is an area that uses a common standard time. Currently, there are 40 time zones. Each time zone is distinguished by the time difference between standard time and UTC. For example, Japan belongs to the “+9 hour time zone” using standard time 9 hours ahead of UTC.
A numeric time difference display unit 45 represents an integer time difference. On the other hand, the symbol time difference display unit 45 represents a time difference other than an integer. The time of the world agreement, which is the standard for the time difference, is represented by the time difference display 45 of the “UTC” symbol. A time difference other than an integer is represented by a time difference display unit 45 of a “•” symbol. Note that the time difference other than the integer time and the world agreement may be expressed using other symbols.

  In the bezel 32, city information 35 is written. The city information 35 represents a representative city name in the time zone using the standard time corresponding to the time difference of the time difference display unit 45. In the present embodiment, the city information 35 is described using a three-letter code in which the city name is abbreviated with a three-letter alphabet. For example, the code “TYO” represents Tokyo. Then, based on the number “9” in the time difference display section 45 that is written on the dial ring 40 corresponding to the “TYO” code, the user can easily use the standard time of UTC + 9 hours in Tokyo. Can be judged.

On the inner peripheral side of the dial ring 40, a dial-shaped dial plate 11 having light transmission properties is arranged. The dial 11 is made of plastic such as polycarbonate. The dial 11 is provided with pointers 21, 22 and 23. Each of the pointers 21, 22 and 23 rotates with the pointer shaft 25 as a rotation axis. The pointer shaft 25 is provided along a central axis extending in the front and back direction through the center of the exterior case 31 in a plan view (hereinafter referred to as “first plan view”) viewed from the display surface 11a side of the dial plate 11. It has been.
The dial 11 and the hand 23 display the time value, and the dial 11 and the hand 22 display the time value. The hand 23 is also called an hour hand, and the hand 22 is also called a minute hand. The dial 11 displays the time according to the position indicated by the rotating pointer 22 and the position indicated by the rotating pointer 23. The dial 11, the hands 22 and the hands 23 constitute a time display unit. The time display unit is housed in the outer case 31 and displays the time through an opening on the front side of the outer case 31. On the dial 11, the measured value of the second digit in the chronograph (stopwatch function) is displayed by the pointer 21.

  The dial 11 has a first display portion 70 and a pointer 71 that are circular at 2 o'clock, a second display portion 80 and a pointer 81 that are circular at 10 o'clock, and a third display portion that is circular at 6 o'clock. 90 and the pointer 91 are provided with a rectangular calendar display section 15 in the 4 o'clock direction.

The 1st display part 70 displays the measured value to 60 minutes with the pointer | guide 71 in a chronograph. The second display unit 80 displays the second value of the time with the hands 81. The pointer 81 is also referred to as a second hand.
On the outer periphery of the third display portion 90 in the range from the 7 o'clock direction to the 9 o'clock direction, a symbol 92 is written along the circumference, with the base end in the 9 o'clock direction being thick and the tip in the 7 o'clock direction being thin. . A symbol 92 is a power indicator of the secondary battery 130. Depending on the remaining amount of the secondary battery 130, the pointer 91 indicates one of the proximal end, the distal end, and the middle of the symbol 92. For example, a rechargeable lithium ion battery is used as the secondary battery 130.
On the outer periphery of the third display portion 90 in the range from 9 o'clock to 10 o'clock, an airplane-shaped symbol 93 is written. Symbol 93 represents an in-flight mode. When aircraft take off and landing, the reception of satellite signals is prohibited by the Aviation Law. The user can stop receiving the satellite signal by the electronic timepiece 10 by operating the button 61 and selecting the symbol 93 (airplane mode) with the hands 91.

  On the side surface of the outer case 31, on the dial 11, a button 61 at the 8 o'clock position, a button 62 at the 10 o'clock position, a button 63 at the 2 o'clock position, a button 64 at the 4 o'clock position, and A crown 50 is provided at a position in the 3 o'clock direction. When each of the buttons 61, 62, 63 and 64 and the crown 50 is operated, an operation signal corresponding to the operation is output. A drive mechanism 140 that drives the hands 21, 22, 23, 71, 81, and 91 is also provided inside the outer case 31.

  The drive mechanism 140 is attached to the main plate 125. The base plate 125 is disposed on the back cover 34 side of the dial 11 inside the outer case 31. Between the main plate 125 and the dial plate 11, a solar panel 135 that is a solar power generation device that performs photovoltaic power generation is provided. The solar panel 135 is a circular flat plate in which a plurality of solar cells (photovoltaic elements) that convert light energy into electric energy (electric power) are connected in series. The solar panel 135 also has a sunlight detection function. The dial 11, the solar panel 135, and the ground plate 125 are formed with a hole through which the pointer shaft 25 passes and an opening of the calendar display unit 15.

  The driving mechanism 140 is covered from the back cover 34 side by the surface 120a of the circuit board 120 on the dial plate 11 side. The drive mechanism 140 includes a step motor for driving the pointer 21, a step motor for driving the pointer 22 and the pointer 23, a step motor for driving the pointer 71, a step motor for driving the pointer 81, and a step for driving the pointer 91. A motor and a step motor for driving a date wheel for displaying the date on the calendar display unit 15 are provided.

  The circuit board 120 is disposed on the back cover 34 side of the dial 11 inside the outer case 31. A GPS receiving unit (receiving module) 122 and a control unit 150 are mounted on the surface 120b of the circuit board 120 on the back cover 34 side. Further, a conductive circuit holder 123 that covers the GPS receiver 122 and the controller 150 is provided on the surface 120 b of the circuit board 120. The circuit retainer 123 is connected to the back cover 34 via a conduction spring 124.

  The secondary battery 130 such as a lithium ion battery is disposed on the back cover 34 rather than the dial 11 inside the outer case 31. Furthermore, the secondary battery 130 is provided between the ground plate 125 and the back cover 34. A part of the secondary battery 130 is covered with a back cover more than the circuit board 120 in a plan view (hereinafter referred to as “second plan view”) viewed from a direction A parallel to the in-plane direction of the dial 11 (display surface 11a). It is located on the 34th side. The other part of the secondary battery 130 is located closer to the dial plate 11 than the circuit board 120 in the second plan view. The secondary battery 130 is a power storage device that is charged with power generated by the solar panel 135. In the present embodiment, as the secondary battery 130, a battery having a diameter of 9 mm and a thickness of 3.7 mm having a relatively small diameter is used. The size of the secondary battery 130 is not limited to the above and can be changed as appropriate.

  The dial ring 40 includes a flat plate portion 40a provided in parallel to the cover glass 33, and an inclined portion 40b inclined from the inner periphery of the flat plate portion 40a to the dial plate 11 side. The outer peripheral end of the flat plate portion 40 a is in contact with the inner peripheral surface of the bezel 32, and the inner peripheral end of the inclined portion 40 b is in contact with the dial 11. The dial ring 40 has a ring shape in the first plan view. The dial ring 40 has a mortar shape in a cross-sectional view of the dial ring 40 viewed from a direction A parallel to the in-plane direction of the dial 11 (display surface 11a) (hereinafter simply referred to as “cross-sectional view”). ing.

A cylindrical storage space is formed by the flat plate portion 40a, the inclined portion 40b, the inner peripheral surface of the bezel 32, the inner peripheral surface of the exterior case 31, and the like. In this storage space, a cylindrical antenna body (ring antenna) 110 is stored. For this reason, the antenna body 110 is disposed inside the outer case 31.
FIG. 4 is a perspective view of the antenna body 110. The antenna body 110 includes a base body 110a formed of an annular dielectric body surrounding the outer periphery of the dial plate 11, and an antenna electrode 110b installed on the base body 110a.

  The antenna body 110 is obtained by forming a metal antenna electrode 110b on a base 110a by plating or silver paste printing. The base 110a, which is a dielectric, is formed such that a dielectric material such as titanium oxide that can be used at high frequencies is mixed with a resin so that the relative dielectric constant εr is about 5 to 20. Thereby, the antenna body 110 can be further downsized in combination with the shortening of the wavelength of the dielectric.

The antenna electrode 110b has a first antenna pattern 110b1 installed on the surface of the base 110a on the cover glass 33 side and a second antenna pattern 110b2 installed on the inner surface of the base 110a. The first antenna pattern 110b1 and the second antenna pattern 110b2 are made of metal or other conductive material. The first antenna pattern 110b1 and the second antenna pattern 110b2 can be formed, for example, by plating or silver paste printing.
The first antenna pattern 110b1 has a notch 110b1a and is formed in a C shape with a part of a circle cut out. The first antenna pattern 110b1 has an antenna length that resonates with the radio wave (satellite signal) from the GPS satellite 8.
The second antenna pattern 110b2 is an arc-shaped element, and is formed so as to maintain a certain distance from the first antenna pattern 110b1. The two first antenna patterns 110b1 and second antenna patterns 110b2 function as antenna electrodes 110b that are electromagnetically coupled to each other and convert electromagnetic waves into current. The second antenna pattern 110b2 is a portion formed of a conductive material that is fed by the feeding portion, and is also called an excitation element. By appropriately setting the length of the second antenna pattern 110b2, it is possible to match the impedance of the circuit electrically connected to the antenna body 110 and the impedance of the antenna body 110.

The frequency of the radio wave from the GPS satellite 8 is about 1.575 GHz, and one wavelength is about 19 cm. In order to receive circularly polarized waves, an antenna length of about 1.0 to 1.2 times the wavelength is required. Therefore, in order to receive radio waves from the GPS satellite 8, a loop antenna of about 19 to 24 cm is used. Is required. When a loop antenna having such an antenna length is accommodated in the wristwatch, the wristwatch becomes large.
On the other hand, in the present embodiment, the antenna body 110 has a base 110a formed of a material having a relative dielectric constant εr of about 5 to 20. When the base 110a having the relative dielectric constant εr is used, the wavelength shortening rate by the base is (εr) −1/2. That is, by using a dielectric having a relative dielectric constant of εr, the wavelength of the radio wave received by the antenna body 110 can be shortened to (εr) −½ times. That is, since the antenna body 110 according to the present embodiment includes the base body 110a having the relative dielectric constant εr, the antenna length of the antenna body 110 is (εr) −1/2 compared to the case where the base body 110a is not provided. The antenna body 110 can be reduced in size.

  The element length of the second antenna pattern 110b2 is about 0.25 times the wavelength, and the distance between the second antenna pattern 110b2 and the first antenna pattern 110b1 is about 0.01 times the wavelength. With such an antenna element configuration, it is possible to efficiently generate circularly polarized waves by combining the radiation of the second antenna pattern 110b2 and the first antenna pattern 110b1. In the present embodiment, the example in which the first antenna pattern 110b1 is formed on the surface of the base 110a on the cover glass 33 side and the second antenna pattern 110b2 is formed on the inner surface is described. However, each antenna pattern is in contact with the base 110a. For example, the antenna pattern may be formed on the outer side surface of the base 110a, or the first and second antenna patterns may be formed on the same surface.

In order to further reduce the size of the antenna electrode 110b, it is necessary to improve the effective dielectric constant for the antenna electrode 110b. When the dielectric material is not changed, the effective dielectric constant for the antenna electrode 110b increases as the volume of the substrate 110a that is a dielectric increases.
FIG. 5 is a diagram showing a positional relationship among the base 110a, the secondary battery 130, the circuit board 120, and the dial plate 11 in the second plan view (plan view seen from the direction A parallel to the in-plane direction of the display surface 11a). It is.

As shown in FIG. 5, in the second plan view, a part of the base 110a is a portion of the dial plate 11 and the secondary battery 130 that is located closer to the back cover 34 than the circuit board 120 (hereinafter referred to as “first portion”). And 130a).
For this reason, in the second plan view, the base 110a can be made longer in the normal line H direction of the display surface 11a, compared to the case where the first portion 130a of the secondary battery 130 and the base 110a do not overlap, and the volume of the base 110a. Can be increased. Therefore, the effective dielectric constant with respect to the antenna electrode 110b is improved, and the antenna electrode 110b can be downsized, and thus the electronic timepiece 10 can be downsized.
In addition, the difference between the inner diameter and the outer diameter of the base body 110a can be reduced by increasing the volume of the base body 110a by elongating the base body 110a in the normal line H direction of the display surface 11a. For this reason, in the flat plate portion 40a of the dial ring 40, the width in the direction toward the pointer shaft 25 can be reduced. Therefore, the diameter of the display surface 11a (the inner diameter of the dial ring 40, that is, the diameter at which the dial 11 can be visually recognized) can be increased. Therefore, the degree of freedom in the design of the watch can be increased. The diameter of the display surface 11a is also referred to as “parting diameter”.

Further, in addition to a portion of the base 110 a overlapping the first portion 130 a of the secondary battery 130, at least a portion of the antenna electrode 110 b is disposed closer to the cover glass 33 than the display surface 11 a of the dial 11. Has been.
For this reason, compared with the case where the 1st part 130a of the secondary battery 130 and the base | substrate 110a have not overlapped in 2nd planar view, the dielectric material whose dielectric constant is higher than air is used for the antenna electrode 110b and the secondary battery 130. Since it can be interposed, the electrical length between the secondary battery 130 and the exterior case 31 and the back cover 34, which are metal members, and the antenna electrode 110b can be increased. Therefore, the influence of the battery or the metal member on the antenna electrode 110b can be reduced, and as a result, the reception performance of the antenna body 110 can be improved. Since the first antenna pattern 110b1 of the antenna electrode 110b is particularly affected by the secondary battery 130 or the outer case 31 and the back cover 34, which are metal members, it is preferable to increase the electrical length of these.
Note that a part of the base 110a overlaps the dial 11 in the second plan view. In addition, a part of the base 110a overlaps the circuit board 120 in the second plan view.

As shown in FIG. 4, the base 110a is provided with six notches (notches 110c1 to 110c6). The notch 110c1, the notch 110c2, the notch 110c3, the notch 110c4, and the notch 110c5 are provided at locations facing the button 61, the button 62, the button 63, the button 64, and the crown 50, respectively. The buttons 61 to 64 and the crown 50 are examples of operation members.
On the other hand, a protruding portion 125 a that protrudes to the outer peripheral side of the ground plate 125 is provided at a position facing each of the notches 110 c 1 to 110 c 6 in the outer periphery of the ground plate 125.
The position of the antenna body 110 in the vertical direction with respect to the ground plate 125 is determined by the contact between the surface on the back cover 34 side of each of the cutout portions 110c1 to 110c6 and the surface on the cover glass 33 side of the protruding portion 125a. Moreover, the movement of the antenna body 110 in the circumferential direction with respect to the ground plane 125 is also restricted by the side surfaces of the notches 110c1 to 110c6 coming into contact with the side surfaces of the protruding portion 125a. Therefore, the base 110a can be positioned with reference to the protrusion 125a. In addition, it is possible to suppress the positional deviation of the antenna body 110 with respect to the ground plane 125 due to the drop or impact of the electronic timepiece 10. The number of notches 110c is not limited to six and can be changed as appropriate.

FIG. 6 is an enlarged view of the power feeding mechanism of the antenna body 110, specifically, the region D of FIG. 4 in a situation where the antenna body 110 is incorporated in the electronic timepiece 10.
As shown in FIG. 6, the notch 110c is provided with a power feed pin 128 that is electrically connected to the antenna electrode 110b. The power supply pin 128 is electrically connected to the wiring 126 provided on the circuit board 120 through the through hole 125a1 provided in the protruding portion 125a. A predetermined potential is supplied from the wiring 126 to the power supply pin 128. Therefore, it is possible to feed power to the antenna body 110 through the notch 110c. The circuit board 120 is held by a circuit holder 123. Here, the circuit board 120 and the circuit retainer 123 also have protrusions at positions facing the notches 110c.

Next, the electrical configuration of the electronic timepiece 10 will be described.
FIG. 7 is a block diagram showing a circuit configuration of the electronic timepiece 10.
As shown in FIG. 7, the electronic timepiece 10 includes a GPS receiving unit 122, a control display unit 155, a charging control circuit 29, and a solar panel 135. Further, the electronic timepiece 10 has a secondary battery 130 built therein.
The GPS receiver 122 performs processing such as reception of satellite signals, acquisition of GPS satellites 8, and generation of position information. The control display unit 155 performs processing such as holding internal time information and correcting internal time information. The solar panel 135 charges the secondary battery 130 through the charge control circuit 29.

Electronic timepiece 10 includes regulators 162 and 163 and a voltage detection circuit 164.
The secondary battery 130 supplies driving power to the control display unit 155 via the regulator 162 and supplies driving power to the GPS receiving unit 122 via the regulator 163. Instead of the regulator 163, for example, a regulator 163-1 that supplies driving power to an RF unit 170 described later, and a regulator 163-2 (both not shown) that supplies driving power to a baseband unit 180 described later. May be provided. The regulator 163-1 may be provided inside the RF unit 170. The voltage detection circuit 164 detects the voltage of the secondary battery 130.

The electronic timepiece 10 includes an antenna body 110 and a SAW (Surface Acoustic Wave) filter 190.
As described above, the antenna body 110 receives satellite signals wirelessly transmitted from the plurality of GPS satellites 8. The antenna body 110 also receives unnecessary radio waves other than satellite signals. For this reason, the SAW filter 190 extracts a satellite signal from the signal received by the antenna body 110. That is, the SAW filter 190 functions as a band-pass filter that passes a 1.5 GHz band signal. Note that the SAW filter 190 may be incorporated in the GPS receiving unit 122.

  The GPS receiving unit 122 includes an RF (Radio Frequency) unit 170 and a baseband unit 180. The GPS receiving unit 122 acquires satellite information such as orbit information and GPS time information included in the navigation message from the 1.5 GHz band satellite signal extracted by the SAW filter 190.

  The RF unit 170 includes an LNA (Low Noise Amplifier) 171, a mixer 172, a VCO (Voltage Controlled Oscillator) 173, a PLL (Phase Locked Loop) circuit 174, an IF amplifier 175, an IF (Intermediate Frequency) filter 176, and an ADC (ADC). A / D converter) 177 and the like.

The satellite signal extracted by the SAW filter 190 is amplified by the LNA 171. The satellite signal amplified by the LNA 171 is mixed with the clock signal output from the VCO 173 by the mixer 172 and down-converted to an intermediate frequency band signal.
The PLL circuit 174 compares the phase of the clock signal obtained by dividing the output clock signal of the VCO 173 with the reference clock signal, and synchronizes the output clock signal of the VCO 173 with the reference clock signal. As a result, the VCO 173 can output a clock signal with a stable frequency accuracy of the reference clock signal. For example, several MHz can be selected as the intermediate frequency.

  The signal mixed by the mixer 172 is amplified by the IF amplifier 175. Here, by the mixing in the mixer 172, a high frequency signal of several GHz is generated together with the signal in the intermediate frequency band. Therefore, the IF amplifier 175 amplifies a high frequency signal of several GHz together with the intermediate frequency band signal. The IF filter 176 passes a signal in the intermediate frequency band and removes a high frequency signal of several GHz (precisely, attenuates to a predetermined level or less). The intermediate frequency band signal that has passed through the IF filter 176 is converted into a digital signal by the ADC 177.

  The baseband unit 180 includes a DSP (Digital Signal Processor) 181, a CPU 182, and a RAM (Random Access Memory) 183. The baseband unit 180 is connected to a crystal oscillation circuit with temperature compensation circuit (TCXO: Temperature Compensated Crystal Oscillator) 185, a flash memory 186, and the like.

A crystal oscillation circuit (TCXO) 185 with a temperature compensation circuit generates a reference clock signal having a substantially constant frequency regardless of the temperature.
The flash memory 186 stores, for example, time difference information (time difference information for UTC) associated with positioning information (latitude and longitude). The flash memory 186 stores a program that defines the operation of the baseband unit 180.
The CPU 182 controls the baseband unit 180, more specifically, the GPS receiving unit 122, by reading and executing a program stored in the flash memory 186. Instead of the flash memory 186, an EEPROM (Electrically Erasable Programmable Read-Only Memory) may be used.

  The baseband unit 180 demodulates the baseband signal from the digital signal (intermediate frequency band signal) converted by the ADC 177 of the RF unit 170.

  The baseband unit 180 generates a local code having the same pattern as each C / A code in a satellite search described later, and correlates each C / A code included in the baseband signal with the local code. Then, the baseband unit 180 adjusts the local code generation timing so that the correlation value for each local code has a peak. If the correlation value is equal to or greater than the threshold value, the baseband unit 180 is synchronized with the GPS satellite 8 of the local code (that is, , GPS satellite 8 is captured). Here, the GPS system employs a CDMA (Code Division Multiple Access) method in which all GPS satellites 8 transmit satellite signals of the same frequency using different C / A codes. Therefore, by detecting the C / A code included in the received satellite signal, the GPS satellite 8 that can be captured can be searched.

In addition, the baseband unit 180 mixes a local code and a baseband signal having the same pattern as the C / A code of the GPS satellite 8 in order to acquire satellite information of the captured GPS satellite 8. In the mixed signal, the navigation message including the satellite information of the captured GPS satellite 8 is demodulated. Then, the baseband unit 180 detects the TLM word (preamble data) of each subframe of the navigation message, and acquires satellite information such as orbit information and GPS time information included in each subframe. Then, the baseband unit 180 stores the satellite information in the RAM 183. The GPS time information is week number data (WN) and Z count data, but if week number data has been acquired previously, only Z count data may be acquired.
The week number data is information representing a week including the current GPS time information. The starting point of the GPS time information is UTC, January 6, 1980, 00:00:00, and the week starting on this day is the week number 0. Week number data is updated on a weekly basis.
The Z count data indicates the elapsed time from 0:00 every Sunday in seconds, and returns to 0 at 0:00 on the next Sunday. That is, the Z count data is information in units of seconds indicated every week from the beginning of the week.
Hereinafter, an example in which Z count data is used as GPS time information will be described.

The baseband unit 180 has a time information acquisition mode and a position information acquisition mode.
In the time information acquisition mode, the baseband unit 180 performs time measurement calculation based on the GPS time information (Z count data).
In the position information acquisition mode, the baseband unit 180 performs positioning calculation based on the GPS time information and the orbit information, and acquires position information (latitude and longitude of the place where the electronic timepiece 10 is located at the time of reception). Subsequently, the baseband unit 180 refers to the flash memory 186 and acquires time difference information associated with the coordinate values (for example, latitude and longitude) of the electronic timepiece 10 specified by the position information.

  The operation of the baseband unit 180 is synchronized with a reference clock signal output from a crystal oscillation circuit with temperature compensation circuit (TCXO) 185.

The control display unit 155 includes a control unit 150, a drive circuit 154, and a crystal resonator 153.
The control unit 150 includes a storage unit 151 and an RTC 152 and performs various controls. The control unit 150 can be configured by a CPU, for example. The controller 150 sends a control signal to the GPS receiver 122 and controls the reception operation of the GPS receiver 122. Further, the control unit 150 controls the operations of the regulator 162 and the regulator 163 based on the detection result of the voltage detection circuit 164.
Further, the control unit 150 controls the driving of the hands 21, 22, 23, 71, 81 and 91 and the date indicator via the drive circuit 154. The drive circuit 154 includes a drive circuit for the hands 21, a drive circuit for the hands 22 and 23, a drive circuit for the hands 71, a drive circuit for the hands 81, a drive circuit for the hands 91, And a driving circuit for a vehicle.

  The storage unit 151 stores information (Z count data and time difference information) generated by the baseband unit 180. The control unit 150 corrects the internal time information based on the information generated by the baseband unit 180. The internal time information is information on the internal time measured by the electronic timepiece 10. The internal time information is counted by the RTC 152 that is always driven, and is updated by the reference clock signal generated by the crystal resonator 153. Therefore, even when the power supply to the GPS receiver 122 is stopped, the internal time information can be updated and the hands of the hands 22, 23 and 81 can be continued.

  In the time information acquisition mode, the control unit 150 operates the GPS reception unit 122, corrects the internal time information based on the GPS time information (Z count data), and stores it in the storage unit 151. More specifically, the internal time information is corrected to a time obtained by adding a UTC offset to the acquired GPS time information.

  In addition, the control unit 150 operates the GPS receiving unit 122 even in the position information acquisition mode, and performs positioning calculation using the satellite signal. And the control part 150 corrects internal time information based on the time difference information according to the positioning calculation result, and memorize | stores it in the memory | storage part 151. FIG.

Second Embodiment
FIG. 8 is a view showing an electronic timepiece 10A according to the second embodiment of the present invention. In FIG. 8, the same components as those shown in FIG. In the electronic timepiece 10A shown in FIG. 8, a secondary battery 130b that is thinner than the secondary battery 130 shown in FIG. 3 is used. The secondary battery 130b is located on the surface 120b side of the circuit board 120 in the second plan view.

Also in the present embodiment, in the second plan view, a part of the base 110a overlaps with a part of the secondary battery 130b located on the back cover 34 side with respect to the circuit board 120.
For this reason, in the second plan view, the base in the normal line H direction of the display surface 11a compared to the case where the portion of the secondary battery 130b positioned on the back cover 34 side of the circuit board 120 and the base 110a do not overlap. 110a can be lengthened, and the volume of the base 110a can be increased.

<Third Embodiment>
FIG. 9 is a view showing an electronic timepiece 10B according to the third embodiment of the present invention. In FIG. 9, the same components as those shown in FIG. The electronic timepiece 10 </ b> B shown in FIG. 9 has an antenna holding portion 129 that holds the antenna body 110. The antenna holding part 129 shown in FIG. 9 has a recess into which a part of the antenna body 110 on the back cover 34 side is fitted. The antenna holding portion 129 having a recess may be provided at a plurality of locations.
According to this embodiment, since the antenna holding part 129 holds the antenna body 110, the positional deviation of the antenna body 110 can be suppressed. The antenna holding portion 129 may be formed by the ground plane 125.

<Fourth embodiment>
In the electronic timepiece according to the fourth embodiment of the present invention, an antenna fixing portion that fixes the antenna body 110 is provided on the projecting portion 125a of the ground plate 125, and an engagement portion that engages with the antenna fixing portion is provided on the base 110a. This is different from the electronic timepiece 10 of the first embodiment. Hereinafter, the fourth embodiment will be described focusing on differences from the first embodiment.
FIG. 10 is a diagram illustrating an example of the antenna fixing portion 125a3 and the engaging portion 110a1. FIG. 11 is a cross-sectional view of the antenna fixing portion 125a3 and the engaging portion 110a1.
An antenna fixing portion 125a3 and a protruding portion 125a2 are provided on the outer case 31 side of the protruding portion 125a. The antenna fixing portion 125a3 is a key claw that engages with the engaging portion 110a1 of the base 110a, and fixes the antenna body 110 to the ground plate 125. The protrusion 125 a 2 is in contact with the inner peripheral surface of the outer case 31 and determines the positions of the ground plate 125 and the outer case 31.

<Modification>
The present invention is not limited to the above-described embodiments. For example, various modifications as described below are possible. Further, one or a plurality of modifications arbitrarily selected from the modifications described below can be appropriately combined.

<Modification 1>
In the second plan view, a part of the first portion 130a of the secondary battery 130 may not overlap the base 110a.

<Modification 2>
All or part of the first display unit 70, the second display unit 80, the third display unit 90, and the calendar display unit 15 may be omitted.

<Modification 3>
In the second plan view, the base body 110a may overlap only with the circuit board 120 of the secondary battery 130 on the cover glass 33 side. In this case, the circuit board 120 may be disposed on the back cover 34 side of the secondary battery 130.

<Modification 4>
Although the antenna electrode 110b has been described as having the first antenna pattern 110b1 that is not fed and the second antenna pattern 110b2 that is fed, the antenna electrode 110b is not limited to this. For example, the antenna electrode 110b may be a C-shaped antenna pattern, and a pair of feeding points that feed power to the start point and the end point may be provided. In this case, both ends of the antenna pattern, that is, the peripheral length from the start point to the end point of the loop antenna is set to about one wavelength that is shortened by the dielectric.

<Modification 5>
Although the radio wave from the GPS satellite 8 has been described as an example of the radio wave received by the electronic timepiece 10, the radio wave is not limited to this. For example, radio waves from satellites used in other global public navigation satellite systems (GNSS) such as Galileo (EU) and GLONASS (Russia) can be applied. Radio waves from geostationary satellites such as geostationary satellite navigation augmentation system (SBAS) and satellites such as regional satellite positioning system (RNSS) that can be searched only in specific areas such as quasi-zenith satellite (MICHIBIKI) can also be applied. .

DESCRIPTION OF SYMBOLS 10 ... Electronic timepiece, 11 ... Dial, 11a ... Display surface, 110 ... Antenna body, 120 ... Circuit board, 130 ... Secondary battery.

Claims (6)

A cylindrical outer case,
A dial stored in the outer case;
A back cover that closes one opening of the exterior case;
A battery disposed on the back cover side of the dial on the inside of the exterior case;
An antenna body that is disposed inside the outer case and includes a base formed of a ring-shaped dielectric and an antenna electrode placed on the base;
The electronic timepiece according to claim 1, wherein the base body overlaps at least a part of the dial and at least a part of the battery in a plan view as viewed from a direction parallel to an in-plane direction of the dial. Including a circuit board disposed on the back cover side of the dial inside the exterior case,
In the plan view, at least a part of the battery is located on the back cover side of the circuit board, and a part of the base is located on the back cover side of the circuit board. The electronic timepiece according to claim 1, wherein the electronic timepiece overlaps at least a part of the portion. Including a main plate disposed on the back cover side of the dial inside the outer case,
On the outer periphery of the base plate, a protruding portion protruding toward the exterior case side is provided,
The electronic timepiece according to claim 1, wherein the base is provided with a notch at a position facing the protruding portion.   4. The electronic timepiece according to claim 3, wherein the notched portion is provided with a power feeding element that is electrically connected to the antenna electrode and is fed with a predetermined potential. 5.   5. The electronic timepiece according to claim 3, wherein the protruding portion is provided with a protruding portion that comes into contact with the exterior case. Including an operation member,
6. The electronic timepiece according to claim 3, wherein the cutout portion is provided at a location facing the operation member.

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