Electronic clock

Abstract

An electronic timepiece is provided, which can improve the electromagnetic coupling between antenna elements. The electronic timepiece comprises: a ring-shaped antenna substrate having an upper surface, an outer peripheral surface, a bottom surface, and an inner peripheral surface; a first antenna element disposed on the outer peripheral surface; and a second antenna element disposed on the inner peripheral surface, at least one of the first antenna element and the second antenna element having a power supply terminal connected to a power supply unit, and a spacing between the first antenna element and the second antenna element being greater than 0 mm and less than 2 mm.

Description

Technical Field

[0001] The present invention relates to an electronic clock with a built-in loop antenna. Background Art

[0002] There is known an electronic timepiece having a built-in loop antenna for receiving satellite signals transmitted from GPS (Global Positioning System) satellites (see, for example, Patent Document 1).

[0003] The loop antenna of Patent Document 1 discloses a structure in which an excitation element powered from a power source and a C-type loop element as a non-powered element are provided on the inner and outer peripheral surfaces of a ring-shaped substrate having a rectangular cross section.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2013-183437

[0005] In Patent Document 1, there is a problem that the two antenna elements are separated and the electromagnetic coupling between the elements is weakened. Summary of the invention

[0006] The electronic timepiece comprises: a ring-shaped antenna substrate having an upper surface, an outer peripheral surface, a bottom surface, and an inner peripheral surface; a first antenna element arranged on the outer peripheral surface; and a second antenna element arranged on the inner peripheral surface, at least one of the first antenna element and the second antenna element having a power supply terminal connected to a power supply part, and a spacing between the first antenna element and the second antenna element is greater than 0 mm and less than 2 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a top view showing the electronic timepiece according to the embodiment.

[0008] Figure 2 It is a cross-sectional view showing the electronic timepiece according to the embodiment.

[0009] Figure 3 It is an exploded perspective view showing the main parts of the electronic timepiece according to the embodiment.

[0010] Figure 4 It is a block diagram showing a circuit configuration of an electronic timepiece according to an embodiment.

[0011] Figure 5 It is a perspective view showing an antenna body according to the embodiment.

[0012] Figure 6 It is a cross-sectional view showing the antenna body according to the embodiment.

[0013] Figure 7 It is an enlarged perspective view showing the mounting structure of the solar cell panel according to the embodiment.

[0014] Figure 8 It is an enlarged perspective view showing the mounting structure of the dial according to the embodiment.

[0015] Fig. 9 It is a characteristic diagram showing the radiation pattern of the antenna body.

[0016] Fig.10 It is a graph showing the characteristics of the antenna body.

[0017] Fig.11 It is a graph showing the characteristics of the antenna body.

[0018] Fig.12 It is a perspective view showing an antenna body according to a modified example.

[0019] Fig.13 : is a cross-sectional view of an antenna body showing a modified example.

[0020] Description of symbols

[0021] 10: electronic clock; 11: dial; 11A: fixing convex part; 15: calendar window; 16: calendar wheel; 21: pointer; 22: pointer; 23: pointer; 25: pointer shaft; 26: pointer shaft; 27: pointer shaft; 28: pointer shaft; 30: outer shell; 31: shell; 32: bezel; 33: glass cover; 34: back cover; 40: scale ring; 41: flat plate; 42: inclined part; 50: crown; 61: A button; 62: B button; 63: C button; 64: C button; 65: C button; 66: C button; 67: C button; 68: C button; 69: C button; 70: C button; 71: C button; 72: C button; 73: C button; 74: C button; 75: C button; 76: C button; 77: C button; 78: C button; 79: C button; 80: C button; 81: C button; 82: C button; 83: C button; 84: C button; 85: C button; 86: C button; 87: C button; 88: C button; 89: C button; 90: C button; 91: C button; 92: C button; 93: C button; 94: C button; 95: C button; 96: C button; 97: C button; 98: C button; 99: C button; 10: electronic clock; 11: dial; 11: 4: D button; 70: first small window; 71: pointer; 80: second small window; 81: pointer; 90: third small window; 91: pointer; 115: antenna connection pin; 116: bottom plate support; 120: circuit substrate; 122: circuit pressing member; 125: bottom plate; 125A: fixing convex part; 125B: fixing pin; 126: anti-magnetic plate; 127: anti-magnetic plate; 130: secondary battery; 135: solar cell panel; 135A: fixing convex part; 140: drive actuating mechanism; 200: antenna body; 210: antenna substrate; 211: upper surface; 212: outer peripheral surface; 213: bottom surface; 214: inner peripheral surface; 215: first inner peripheral surface; 216: second inner peripheral surface; 217: recess; 218: recess; 220: antenna element; 221: first antenna element; 221C: power supply terminal; 225: second antenna element; 225A: first inner peripheral portion; 225B: second inner peripheral portion; 225C: power supply terminal; 230: SAW filter : wave filter; 300: GPS receiving unit; 310: RF unit; 320: baseband unit; 340: flash memory; 400: control display unit; 410: control unit; 411: RTC; 412: ROM; 413: storage unit; 420: drive circuit; 430: quartz oscillator; 500: power supply unit; 510: charging control circuit; 520: first voltage conversion unit; 530: second voltage conversion unit; 540: voltage detection circuit; 901: solid line; 902: dotted line. DETAILED DESCRIPTION

[0022] Hereinafter, an electronic timepiece according to an embodiment of the present disclosure will be described based on the drawings.

[0023] Figure 1 is a plan view of the electronic timepiece 10 as viewed from the front side. Figure 2 is a cross-sectional view showing an outline of an electronic timepiece, Figure 3 It is an exploded perspective view of the main parts of the electronic timepiece 10 .

[0024] The electronic timepiece 10 is a watch that receives radio waves from GPS (Global Positioning System) satellites to correct the internal time, and displays the time on the surface (hereinafter referred to as the front) opposite to the surface (hereinafter referred to as the back) on the side that contacts the arm. GPS satellites are navigation satellites that orbit the earth in a predetermined orbit, superimposing navigation messages on 1.57542 GHz radio waves (L1 waves) and sending them to the ground. In the following description, the 1.57542 GHz radio waves superimposed with navigation messages are referred to as satellite signals. Satellite signals are circularly polarized waves of right-handed polarized waves.

[0025] like Figure 1 as well as Figure 2 As shown, the electronic timepiece 10 includes an outer case 30, a glass cover 33, and a metal back cover 34. The outer case 30 is formed by fitting a metal bezel 32 to a metal cylindrical case 31.

[0026] On the side surface of the outer case 30, relative to the center of the dial 11, a button A 61 is provided at the 8 o'clock position, a button B 62 is provided at the 10 o'clock position, a button C 63 is provided at the 2 o'clock position, a button D 64 is provided at the 4 o'clock position, and a crown 50 is provided at the 3 o'clock position.

[0027] The inner side of the outer casing 30 is provided with the following: a scale ring 40, which is mounted on the inner periphery of the bezel 32; a translucent dial 11; a pointer shaft 25, which penetrates the dial 11; pointers 21, 22, 23, which surround the pointer shaft 25; and a drive mechanism 140, which is Figure 2 The hands 71, 81, 91 and the calendar wheel 16 (not shown) are driven.

[0028] The pointer shaft 25 passes through the center of the plane of the outer case 30 and is provided along the forward and reverse directions, that is, the thickness direction of the electronic timepiece 10 , and the pointers 21 , 22 , 23 are mounted thereon.

[0029] On the dial 11, with respect to the plane center thereof, a circular first small window 70 and a pointer 71 are provided at 2 o'clock, a circular second small window 80 and a pointer 81 are provided at 10 o'clock, a circular third small window 90 and a pointer 91 are provided at 6 o'clock, and a rectangular calendar small window 15 is provided at 4 o'clock. The dial 11, the pointers 21, 22, 23, the first small window 70, the second small window 80, the third small window 90, the calendar small window 15, etc. can be seen through the glass cover 33 installed in the opening of the bezel 32.

[0030] Furthermore, a calendar wheel 16 is disposed on the back side of the dial 11 , and the calendar wheel 16 can be seen through the calendar window 15 .

[0031] The dial 11 is a circular plate for displaying the time inside the outer case 30, and is formed of a light-transmitting material made of synthetic resin, and has hands 21, 22, 23, etc. between the dial 11 and the glass cover 33, and is arranged inside the scale ring 40. The dial 11 of this embodiment is made of polycarbonate.

[0032] A solar cell panel 135 for generating photovoltaic power is arranged between the dial 11 and the bottom plate 125 on which the driving mechanism 140 is mounted. Figure 3 As also shown, the solar panel 135 is a circular flat plate formed by connecting a plurality of solar cell units in series to convert light energy into electric energy. The dial 11, the solar panel 135 and the bottom plate 125 are provided with holes through which the pointer shaft 25, the pointer shaft 26 of the pointer 71, the pointer shaft 27 of the pointer 81 and the pointer shaft 28 of the pointer 91 pass, and an opening portion of the calendar window 15 is formed.

[0033] The drive mechanism 140 is mounted on the bottom plate 125 and is covered by the circuit substrate 120 from the back side. The drive mechanism 140 has a gear train such as a stepping motor and a gear. In this embodiment, there are drive mechanisms for driving the pointers 22 and 23, and drive mechanisms for independently driving the pointers 21, 71, 81, 91, and the calendar wheel 16. It should be noted that in this embodiment, the pointer 21 is a chronograph second hand, the pointer 71 is a chronograph minute hand, the pointer 81 is a second hand, the pointer 91 is a chronograph hour hand, and the calendar wheel 16 is a date wheel.

[0034] Antimagnetic plates 126 and 127 are provided on the dial 11 side and the circuit board 120 side of the driving mechanism 140 , respectively.

[0035] The circuit board 120 includes a GPS receiving unit 300 and a control display unit 400. A circuit pressing member 122 for covering these circuit components is provided on the back cover 34 side (back side) of the circuit board 120 where the GPS receiving unit 300 and the control display unit 400 are provided. In addition, a secondary battery 130 such as a lithium ion battery is provided between the bottom plate 125 and the back cover 34, and is charged by the power generated by the solar panel 135.

[0036] The circuit pressing member 122 is provided with an opening for housing the secondary battery 130 in the outer casing 30 . The circuit pressing member 122 is made of a metal plate and has a conductive spring portion 123 that contacts the back cover 34 .

[0037] The scale ring 40 is made of a ring-shaped synthetic resin material having a flat plate portion 41 and an inclined portion 42. The scale ring 40 of the present embodiment is made of ABS (Acrylonitrile Butadiene Styre).

[0038] The flat plate portion 41 is arranged parallel to the glass cover 33, and its outer peripheral end is in contact with the inner peripheral surface of the bezel 32. The inclined portion 42 extends from the flat plate portion 41, and its inner peripheral end is in contact with the dial 11. The surface of the inclined portion 42, i.e., the inner peripheral surface of the scale ring 40, is inclined toward the back side of the electronic timepiece 10, i.e., downward, from the upper end connected to the flat plate portion 41 to the lower end in contact with the dial 11. Therefore, the inner peripheral surface of the scale ring 40 becomes smaller relative to the dial 11 as it moves toward the inner side of the electronic timepiece 10, and the dial 11 can be seen in a wider angle range.

[0039] The scale ring 40 and the bezel 32 form a ring-shaped storage space, and the ring-shaped antenna body 200 is stored in the storage space. A ring-shaped bottom plate support 116 is arranged between the antenna body 200 and the circuit substrate 120. The antenna body 200 is electrically connected to the circuit substrate 120 through the antenna connection pin 115 provided through the bottom plate support 116.

[0040] In addition, the ground pattern of the circuit substrate 120 is connected to the metal back cover 34 via the conductive spring portion 123 of the circuit pressing member 122, and the outer casing 30 and the back cover 34 can also be used as a ground plane together with the circuit substrate 120. By using the outer casing 30 and the back cover 34 as a ground plane, the area of ​​the ground plane can be increased, the antenna gain is increased, and the antenna characteristics can be improved.

[0041] The scale ring 40 is made of a non-conductive material such as synthetic resin, so it does not hinder the radio wave reception of the antenna body 200. In addition, since the scale ring 40 covers the antenna body 200, it can shield the antenna body 200 and prevent the appearance of the electronic timepiece 10 from being inconsistent, thereby improving the appearance design of the electronic timepiece 10.

[0042] [Circuit structure of electronic clock]

[0043] Figure 4 2 is a block diagram showing a circuit configuration of the electronic timepiece 10 .

[0044] The electronic timepiece 10 includes a GPS receiving unit 300 , a control display unit 400 , and a power supply unit 500 , which are arranged on a circuit board 120 .

[0045] [GPS receiving unit]

[0046] The GPS receiving unit 300 receives and processes satellite signals from GPS satellites via the GPS antenna body 200 and the SAW (Surface Acoustic Wave) filter 230. The SAW filter 230 is a bandpass filter that allows 1.5 GHz satellite signals to pass through. It should be noted that an LNA (Low Noise Amplifier) ​​that improves the receiving sensitivity may also be inserted between the antenna body 200 and the SAW filter 230. In addition, a structure in which the SAW filter 230 is assembled into the GPS receiving unit 300 may also be adopted.

[0047] The GPS receiving unit 300 processes the satellite signal that has passed through the SAW filter 230 , and includes an RF (Radio Frequency) unit 310 , a baseband unit 320 , a crystal oscillator circuit (TCXO) 330 with a temperature compensation circuit, and a flash memory 340 .

[0048] The RF unit 310 is a general RF unit for GPS reception including a PLL (Phase Locked Loop), a VCO (Voltage Controlled Oscillator), an LNA (Low Noise Amplifier), a mixer, an IF (Intermediate Frequency) amplifier, an IF filter, an ADC (A / D converter), and the like.

[0049] The baseband unit 320 is a general baseband unit for GPS reception that includes a DSP (Digital Signal Processor), a CPU (Central Processing Unit), an RTC (Real Time Clock), an SRAM (Static Random Access Memory), etc. The baseband unit 320 is also connected to a TCXO 330 and a flash memory 340 .

[0050] The baseband unit 320 receives the received signal converted into a digital signal from the RF unit 310, obtains satellite time information and positioning data by performing correlation processing, positioning calculation, etc., corrects the obtained satellite time information, i.e., Z count, using the leap second stored in the SRAM, and calculates the coordinated universal time, i.e., UTC, as time data. Thus, the baseband unit 320 outputs the positioning data and time data to the control and display unit 400.

[0051] A clock that serves as a basis for the local oscillation signal is supplied from the TCXO 330 to the RF unit 310 via the baseband unit 320 .

[0052] The flash memory 340 stores a time difference database that establishes a correspondence between the location information determined by the latitude and longitude and the time difference information of the place. When the GPS receiving unit 300 obtains the location information in the positioning mode, it obtains the time difference information, i.e., the time difference relative to UTC, based on the location information (latitude, longitude), and outputs it to the control display unit 400.

[0053] [Control and display unit]

[0054] The control display unit 400 includes a control unit (CPU) 410 , a drive circuit 420 that drives hands and the like, and a crystal oscillator 430 .

[0055] The control unit 410 includes an RTC (Real Time Clock) 411 , a ROM 412 , and a storage unit 413 , and measures time and outputs a control signal to the GPS receiving unit 300 to control the operation thereof.

[0056] The RTC 411 uses the reference signal output from the quartz oscillator 430 to measure the internal time. The ROM 412 stores various programs executed by the control unit 410. In the present embodiment, the internal time measured by the RTC 411 is the Coordinated Universal Time, i.e., UTC. When reception in the time measurement mode or the positioning mode is successful, the control unit 410 updates the RTC 411 using the UTC output from the GPS receiving unit 300.

[0057] The storage unit 413 stores satellite time information, positioning information, and time difference information output from the GPS receiving unit 300. Therefore, the control unit 410 calculates the current time at the location based on UTC and the time difference information, drives the drive mechanism 140 through the drive circuit 420, and uses the hands 22, 23, and 81 to indicate the calculated time.

[0058] [Power supply unit]

[0059] The power supply unit 500 supplies power to the GPS receiving unit 300 and the control display unit 400 , and includes a solar cell panel 135 , a charging control circuit 510 , a secondary battery 130 , a first voltage conversion unit 520 , a second voltage conversion unit 530 , and a voltage detection circuit 540 .

[0060] The charging control circuit 510 controls charging of the electric power generated by the solar cell panel 135 into the secondary battery 130 .

[0061] The secondary battery 130 supplies driving power to the control and display unit 400 via the first voltage conversion unit 520 , and supplies driving power to the GPS receiving unit 300 via the second voltage conversion unit 530 .

[0062] The voltage detection circuit 540 monitors the output voltage of the secondary battery 130 and outputs the output voltage to the control unit 410. Therefore, the control unit 410 can grasp the voltage of the secondary battery 130 detected by the voltage detection circuit 540 and control the reception process.

[0063] [Structure of the antenna]

[0064] The antenna body 200 is an antenna for receiving GPS satellite signals. Figure 5 and Figure 6 As shown, a ring-shaped dielectric is used as an antenna substrate 210, and an antenna element 220 is formed on the antenna substrate 210 by plating or silver paste printing. The antenna substrate 210 of this embodiment has a complex shape with recessed portions 217 and 218 formed to avoid interference with other components such as buttons 61 to 64, solar cell panel 135, and dial 11. When forming the antenna element 220 on such a complex-shaped antenna substrate 210, it is preferably formed by plating using a laser direct structuring (LDS) process.

[0065] The frequency of radio waves from GPS satellites 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, so a loop antenna of about 19 cm to 24 cm is required to receive radio waves from GPS satellites. If a loop antenna of such an antenna length is stored inside a watch, the watch will become larger.

[0066] In contrast, in this embodiment, the antenna body 200 has a ring-shaped antenna substrate 210 formed by a dielectric having a relative dielectric constant εr of approximately 7 to 15, so that the antenna length can be shortened by the wavelength shortening effect, and the antenna body 200 can be miniaturized to a size that can be stored inside a watch.

[0067] [Antenna substrate]

[0068] Next, the structure of the antenna substrate 210 is described. It should be noted that, in the present embodiment, the central axis direction of the annular antenna substrate 210 is consistent with the axial direction of the pointer shaft 25, that is, the thickness direction of the electronic timepiece 10. In addition, in the thickness direction of the electronic timepiece 10, the front side of the electronic timepiece 10 is defined as the upper side, and the back side is defined as the lower side.

[0069] The antenna substrate 210 includes an upper surface 211, an outer peripheral surface 212, a bottom surface 213, and an inner peripheral surface 214. The inner peripheral surface 214 includes a first inner peripheral surface 215 continuous with the upper surface 211 and a second inner peripheral surface 216 provided between the first inner peripheral surface 215 and the bottom surface 213. The first inner peripheral surface 215 is inclined relative to the central axis direction of the antenna substrate 210, and the lower end of the first inner peripheral surface 215 continuous with the second inner peripheral surface 216 is inclined in a direction close to the central axis of the antenna substrate 210 relative to the upper end of the first inner peripheral surface 215 continuous with the upper surface 211. That is, the lower end of the first inner peripheral surface 215 is located at a position closer to the inner side of the antenna substrate 210 than the upper end.

[0070] In addition, the second inner peripheral surface 216 is formed along the thickness direction of the electronic timepiece 10. Figure 6 As shown, the cross section of the antenna substrate 210 when cut in the diameter direction is a pentagon. The height dimension Tg of the outer peripheral surface 212 and the height dimension Tn of the inner peripheral surface 214 of the cross section of the antenna substrate 210 are set to be greater than the width dimension Wj of the upper surface 211 and the width dimension Wa of the bottom surface 213, and are set to be vertically long as a whole.

[0071] The antenna substrate 210 of this embodiment has arc-shaped recessed portions 217 formed at portions that interfere with the buttons 61 to 64. In addition, a plurality of recessed portions 218 are formed on the inner peripheral surface 214 of the antenna substrate 210. As described later, the recessed portions 218 are formed to prevent interference with the solar cell panel 135 and the fixing protrusions 135A and 11A of the dial 11.

[0072] As the dielectric forming the antenna substrate 210, a dielectric obtained by mixing a ceramic dielectric material used in high frequency such as titanium oxide and a synthetic resin can be used.

[0073] As for the base resin material of the dielectric, PPS (Poly Phenylene Sulfide), LCP (Liquid Crystal Polymer), and polycarbonate are preferred from the perspective of easy application of electroless plating described later. This, combined with the shortening of the wavelength of the dielectric, can further reduce the size. For example, when using an antenna substrate 210 with a relative dielectric constant of εr, the wavelength shortening rate of the antenna substrate 210 is generally (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 200 can be shortened. That is, the antenna body 200 of the present embodiment includes an antenna substrate 210 having a relative dielectric constant of εr, and thus the antenna length of the antenna body 200 can be shortened compared to a case where such an antenna substrate is not provided, and the antenna can be miniaturized.

[0074] The electroless plating forming the antenna element 220 is made of copper, nickel, and gold, and the thickness of the plating layer is as thin as about 10 μm. Therefore, in order to reduce the resistance value of the antenna element 220, the width of the antenna element 220 needs to be about 0.5 mm or more.

[0075] Here, if Figure 6 As shown, the cross section of the antenna substrate 210 of the antenna body 200 of this embodiment is a pentagon, and the width dimension Wj of the upper surface 211 is less than 0.5 mm, which is small. Therefore, if the antenna element 220 is formed on the upper surface 211 of the antenna substrate 210, the width of the antenna element 220 becomes narrower, the resistance value becomes larger, the loss increases, and the antenna gain decreases.

[0076] Therefore, in this embodiment, the first antenna element 221 is formed on the outer peripheral surface 212 of the antenna substrate 210 , and the second antenna element 225 is formed on the inner peripheral surface 214 .

[0077] The first antenna element 221 is formed on the outer peripheral surface 212 of the antenna substrate 210 and is formed into a C-shape with a portion of a ring cut out when the antenna body 200 is viewed from the front of the electronic timepiece 10. The first antenna element 221 has an antenna length that resonates with radio waves from GPS satellites, that is, satellite signals.

[0078] The second antenna element 225 is an arc-shaped element formed on the inner peripheral surface 214 of the antenna substrate 210, and includes a first inner peripheral portion 225A formed on the first inner peripheral surface 215 and a second inner peripheral portion 225B formed on the second inner peripheral surface 216. In addition, the second antenna element 225 includes a power supply terminal 225C formed on the bottom surface 213 at a portion of the circumferential direction of the antenna substrate 210, in this embodiment, at the 6 o'clock position.

[0079] The interval between the first antenna element 221 and the second antenna element 225 is set to be less than the following size: as a part of the circumferential direction of the antenna substrate 210, the antenna substrate 210 is arranged opposite to each other, and the electromagnetic coupling is performed to convert the electromagnetic wave into the current. In the present embodiment, the largest interval between the first antenna element 221 and the second antenna element 225 is the width dimension Wa between the outer peripheral surface 212 and the second inner peripheral portion 225B of the antenna substrate 210, that is, the width dimension Wa of the bottom surface 213. This width dimension Wa, that is, the interval Wa between the first antenna element 221 and the second inner peripheral portion 225B of the second antenna element 225, is set to be greater than 0 mm and less than 2.0 mm. In particular, in the present embodiment, the interval Wa is less than 1.5 mm, for example, 1.3 mm.

[0080] The second antenna element 225 is an element called a power element or an excitation element that is powered via the power supply terminal 225C. By appropriately setting the length of the second antenna element 225, the impedance of the GPS receiving unit 300 electrically connected to the antenna body 200 can be matched with the impedance of the antenna body 200.

[0081] It should be noted that in this embodiment, the circumferential angle range of the first antenna element 221 is set within a range of, for example, 170 to 330 degrees, and the circumferential angle range of the second antenna element 225 is set within a range of, for example, 40 to 160 degrees. Figure 6 is a cross section of a position where the first antenna element 221 and the second antenna element 225 are arranged opposite to each other. Figure 6 The left side of the figure is a cross-section at the 6 o'clock position where the power supply terminal 225C is formed. Figure 6 The figure on the right is a cross section at the 3 o'clock position.

[0082] The width of the first antenna element 221 and the second antenna element 225 is 0.5 mm or more. In the present embodiment, the width of each antenna element 221 and 225 is set to 1 mm or more in the thin part, and 2 mm or more in the other parts. In addition, the first antenna element 221 is provided on the outer peripheral surface 212, so the width W1 of the first antenna element 221 is set to be less than the height dimension Tg of the outer peripheral surface 212. The second antenna element 225 is provided on the inner peripheral surface 214, so the width W2 of the second antenna element 225, that is, the total dimension of the width W21 of the first inner peripheral part 225A and the width W22 of the second inner peripheral part 225B is set to be less than the total dimension of the width Wn of the first inner peripheral surface 215 of the inner peripheral surface 214 and the height dimension Tn2 of the second inner peripheral surface 216. It should be noted that in the present embodiment, the height dimension Tn of the inner peripheral surface 214 of the antenna element 220 is the total dimension of the height dimension Tn1 of the first inner peripheral surface 215 and the height dimension Tn2 of the second inner peripheral surface 216. In addition, the height dimension Ta of the antenna substrate 210 , the height dimension Tn of the inner peripheral surface 214 , and the height dimension Tg of the outer peripheral surface 212 are the same.

[0083] Therefore, the resistance value of the antenna body 200 is small, and the loss is small, so high antenna performance can be obtained. In addition, the aforementioned wavelength shortening effect becomes larger according to the area of ​​contact with the dielectric, so making the width of the antenna element 220 wider is effective for miniaturizing the antenna diameter. Furthermore, by increasing the width of the antenna element 220, the antenna body 200 can be broadbanded, and is not easily affected by the deviation of the assembly size, and stable antenna characteristics can be achieved.

[0084] Next, the mounting structure of the antenna body 200, the solar cell panel 135, the dial 11, and the scale ring 40 will be described.

[0085] The outer peripheral surface 212 of the antenna body 200 is formed with a plurality of notched portions (not shown), and flange portions are provided on the notched portions. The flange portions are engaged with not shown hook portions of the bottom support member 116 , thereby fixing the antenna body 200 to the bottom support member 116 .

[0086] like Figure 7 , 8 As shown, recessed portions 218 are formed at a plurality of locations in the circumferential direction on the inner circumferential surface 214 of the antenna body 200 , and fixing protrusions 125A formed on the bottom plate 125 are arranged in these recessed portions 218 .

[0087] like Figure 7 As shown, a pair of fixing protrusions 135A are formed at multiple locations on the solar cell panel 135 , and the solar cell panel 135 is fixed to the bottom plate 125 by fitting the fixing protrusion 125A into the groove portion between the pair of fixing protrusions 135A.

[0088] like Figure 8 As shown, a pair of fixing protrusions 11A are formed at multiple locations on the dial 11 , and the dial 11 is fixed to the bottom plate 125 by fitting a fixing protrusion 125A into a groove portion between the pair of fixing protrusions 11A.

[0089] A fixing pin 125B formed on the bottom plate 125 is disposed in the recess 218 of the antenna body 200. The scale ring 40 is fixed to the bottom plate 125 by fitting the fixing pin 125B into a hole (not shown) formed on the scale ring 40.

[0090] The antenna body 200 is arranged on the outer periphery of the dial 11 and on the inner side of the bezel 32 , and is covered by the scale ring 40 and the glass cover 33 formed of synthetic resin, so that good reception can be ensured.

[0091] Furthermore, the antenna body 200 is powered via the power supply terminal 225C, as shown in FIG. Figure 2 , 3 As shown in the figure, the antenna connection pin 115 is connected to the power supply terminal 225C. The antenna connection pin 115 is a pin-shaped connector formed of metal, which is arranged to penetrate the bottom plate support member 116 and abuts against the terminal of the antenna power supply circuit of the circuit substrate 120. As a result, the circuit substrate 120 and the antenna body 200 inside the storage space are connected via the antenna connection pin 115. Therefore, the antenna power supply circuit of the circuit substrate 120 and the antenna connection pin 115 constitute a power supply portion connected to the power supply terminal 225C of the second antenna element 225.

[0092] [Antenna characteristics]

[0093] Next, the characteristics of the antenna body 200 according to the present embodiment will be described.

[0094] Fig. 9 is a characteristic diagram showing the radiation pattern of the antenna body 200. Fig. 9 In FIG. 1 , the solid line 901 is the right-hand polarization characteristic of the antenna, and the dotted line 902 is the left-hand polarization characteristic of the antenna. Fig. 9 0 degrees is the dial front direction, 180 degrees is the back cover direction, and 90 degrees and 270 degrees are the side directions of the electronic timepiece 10. Therefore, in the right-handed polarization characteristic, it is possible to obtain directivity in the dial-back cover direction, that is, in the thickness direction of the electronic timepiece 10. Therefore, the antenna body 200 is an antenna suitable for receiving a satellite signal that is a circularly polarized wave that is a right-handed polarized wave.

[0095] then, Fig.10 The curve graph shows the relationship between the size of the first antenna element 221 and the second antenna element 225 and the relative antenna gain.

[0096] Fig.10 The curve graph is a graph of relative antenna gain obtained through simulation, where the relative antenna gain is the antenna gain relative to the size between the first antenna element 221 and the second antenna element 225, which is obtained based on the antenna gain when the size between the first antenna element 221 and the second antenna element 225 is 2.5 mm.

[0097] according to Fig.10 The simulation results show that the antenna gain is improved if the width of the antenna substrate 210 is reduced and the distance between the first antenna element 221 and the second antenna element 225 is reduced. In particular, it is found that the antenna gain is improved if the distance between the antenna elements 221 and 225 is 2 mm or less, preferably 1.5 mm or less, and the antenna characteristics can be improved.

[0098] then, Fig.11 The curve graph shows the relationship between antenna element width and relative antenna gain. Fig.11 The graph of is a graph of relative antenna gain corresponding to the antenna element width obtained by simulation with the case where the antenna element width is 0.5 mm as a reference.

[0099] according to Fig.11 The simulation results shown show that the antenna gain increases when the width of the antenna element 220 increases, that is, when the widths of the first antenna element 221 and the second antenna element 225 increase. In particular, it is found that when the width of each antenna element 221, 225 is 1.0 mm or more, the antenna gain increases compared to the case where the width is 0.5 mm, and the antenna characteristics can be improved.

[0100] [Effects of the Embodiments]

[0101] According to the antenna body 200 of this embodiment, a first antenna element 221 is provided on the outer peripheral surface 212 of the antenna substrate 210, and a second antenna element 225 is provided on the inner peripheral surface 214. Therefore, compared with the case where the antenna element is provided on the upper surface of the antenna substrate 210, the width of the antenna element 220 can be increased, the antenna gain can be maintained, and the antenna substrate 210 can be made thinner, so that the electronic timepiece 10 can be miniaturized.

[0102] Furthermore, since the interval Wa between the first antenna element 221 and the second antenna element 225 is set to be larger than 0 mm and smaller than 2 mm, the two antenna elements 221 and 225 can be easily electromagnetically coupled to each other, the antenna gain can be increased, and the antenna characteristics can be improved.

[0103] In particular, in the present embodiment, the interval Wa between the two antenna elements 221 and 225 is set to 1.5 mm or less, for example, 1.3 mm, so that the antenna characteristics can be further improved.

[0104] Since the widths W1 and W2 of the first antenna element 221 and the second antenna element 225 are set to be greater than 0.5 mm, the resistance of the antenna elements 221 and 225 can be reduced, and the antenna performance can be improved. In particular, in the present embodiment, the widths W1 and W2 of the first antenna element 221 and the second antenna element 225 are set to be greater than 1.0 mm, and thus the antenna characteristics can be further improved.

[0105] The inner circumferential surface 214 of the antenna substrate 210 is composed of a first inner circumferential surface 215 and a second inner circumferential surface 216. The first inner circumferential surface 215 is an inclined surface. Therefore, a scale ring 40 covering the antenna substrate 210 can be set along the inclined first inner circumferential surface 215, which can improve the visibility of the dial 11.

[0106] In addition, compared with the case where the inner circumferential surface is formed along the thickness direction of the electronic timepiece 10, when the first inner circumferential surface 215 and the second inner circumferential surface 216 are provided, the width of the second antenna element 225 formed across these first inner circumferential surfaces 215 and the second inner circumferential surface 216 can be increased, the resistance of the second antenna element 225 can be reduced, and the antenna performance can be improved.

[0107] In the cross section of the annular antenna substrate 210 cut in the radial direction, the antenna substrate 210 is formed into a longitudinal shape in which the height dimensions Tg and Tn of the outer peripheral surface 212 and the inner peripheral surface 214 are larger than the width dimensions Wj and Wa of the upper surface 211 and the bottom surface 213, so that the width dimensions of the first antenna element 221 and the second antenna element 225 formed on the outer peripheral surface 212 and the inner peripheral surface 214 can be increased. Therefore, the resistance of each antenna element 221 and 225 can be reduced, and the area of ​​contact between the antenna elements 221 and 225 and the antenna substrate 210 as a dielectric can be increased, and the wavelength shortening effect can be increased, so that the antenna performance can be improved.

[0108] Since the antenna substrate 210 is formed of PPS, LCP, or polycarbonate, it is possible to manufacture a high dielectric constant, low loss, and easily plated complex-shaped antenna substrate 210. Furthermore, since the antenna elements 221 and 225 are formed by plating, the antenna elements 221 and 225 can be easily formed on the antenna substrate 210 of a complex shape.

[0109] In particular, when the antenna substrate 210 is formed of a dielectric having a relative dielectric constant of 7 or more, a sufficient wavelength shortening effect can be obtained, and the antenna body 200 can be miniaturized.

[0110] A recess 218 is formed on the inner circumferential surface 214 of the antenna substrate 210, and a fixing protrusion 125A and a fixing pin 125B for fixing the solar cell panel 135, the dial 11, and the scale ring 40 are arranged on the recess 218. Therefore, compared with the case where no recess is formed on the inner circumferential surface of the antenna substrate and the inner circumferential surface is arranged on the outside of the fixing protrusion 125A and the fixing pin 125B, the diameter of the antenna substrate 210 can be reduced, the antenna body 200 can be miniaturized, and the electronic timepiece 10 can also be miniaturized.

[0111] The antenna body 200 is covered with the synthetic resin scale ring 40, so that the design can be improved without hindering the antenna performance. In addition, since the metal bezel 32 is used, the appearance of the electronic timepiece 10 can be improved, and the sense of luxury can be enhanced.

[0112] [Other embodiments]

[0113] In addition, the present disclosure is not limited to the above-described embodiments, and modifications, improvements, etc. within the scope that can achieve the purpose of the present disclosure are also included in the present invention.

[0114] For example, in the above embodiment, the power supply terminal 225C is provided in the second antenna element 225, but it may also be provided as follows. Fig.12 as well as Fig.13As shown, a power supply terminal 221C is formed on the first antenna element 221, and the first antenna element 221 formed on the outer peripheral surface 212 is used as a power supply element. In this case, the first antenna element 221 is formed, for example, in a range of about 40 degrees to 160 degrees in the circumferential direction of the antenna substrate 210. In addition, the second antenna element 225 is formed, for example, in a range of about 170 degrees to 330 degrees in the circumferential direction of the antenna substrate 210.

[0115] In addition, in the above embodiment, the width of the first antenna element 221 and the second antenna element 225 is described as being 0.5 mm or more, but even if at least a portion of the width of the power supply terminal 221C or the power supply terminal 225C provided in the first antenna element 221 or the second antenna element 225 is thinner than 0.5 mm, the influence on the antenna gain is small. Therefore, "the width of the first antenna element 221 and the second antenna element 225 is 0.5 mm or more" means that the portion other than the power supply terminal 221C or the power supply terminal 225C is 0.5 mm or more.

[0116] The antenna substrate 210 of the antenna body 200 is not limited to a pentagonal cross section, and an antenna substrate having a rectangular cross section without an inclined surface may also be used. In this case, by forming the antenna substrate into a longitudinal cross section, the width of the first antenna element 221 and the second antenna element 225 formed on the outer peripheral surface and the inner peripheral surface can also be increased, thereby improving the antenna performance. In addition, in this case, the width W2 of the second antenna element 225 is set to be less than the height dimension of the inner peripheral surface. In addition, the antenna substrate 210 may also be an antenna substrate having a hexagonal cross section in which the outer peripheral surface 212 has a first outer peripheral surface along the central axis of the annular antenna substrate 210 and a second outer peripheral surface inclined relative to the above-mentioned central axis. In this case, it is also possible to form the first inner peripheral surface parallel to the second outer peripheral surface. In the above embodiment, a metal bezel 32 is used, but a ceramic bezel may also be used. If a ceramic bezel is used, the bezel portion can also allow satellite signals to pass through, thereby improving the receiving sensitivity.

[0117] The antenna substrate 210 is not limited to a material having a relative dielectric constant of 7 or more, and a material having a relative dielectric constant of less than 7 may be used depending on the type of radio waves to be received, the size of the antenna body 200, that is, the size of the electronic timepiece 10 housing the antenna body 200, etc. In addition, the antenna substrate 210 may be a shape without the recesses 217 and 218 formed therein.

[0118] [Summary of the present disclosure]

[0119] The electronic timepiece disclosed in the present invention comprises: a ring-shaped antenna substrate, which has an upper surface, an outer peripheral surface, a bottom surface, and an inner peripheral surface; a first antenna element, which is arranged on the outer peripheral surface; and a second antenna element, which is arranged on the inner peripheral surface, at least one of the first antenna element and the second antenna element has a power supply terminal connected to the power supply part, and the interval between the first antenna element and the second antenna element is greater than 0 mm and less than 2 mm.

[0120] According to the electronic timepiece disclosed herein, since the first antenna element is formed on the outer peripheral surface of the antenna substrate and the second antenna element is formed on the inner peripheral surface, the width of the antenna element can be increased compared to the case where the antenna element is provided on the upper surface of the antenna substrate, and the antenna gain can be improved.

[0121] Furthermore, since the interval between the first antenna element and the second antenna element is larger than 0 mm and smaller than 2 mm, the two antenna elements can be easily electromagnetically coupled to each other, which can also increase the antenna gain and improve the antenna characteristics.

[0122] In the electronic timepiece of the present disclosure, it is preferable that a distance between the first antenna element and the second antenna element is larger than 0 mm and not more than 1.5 mm.

[0123] Since the interval between the first antenna element and the second antenna element is larger than 0 mm and smaller than 1.5 mm, the width of the antenna substrate can be reduced, and accordingly, the diameter of the antenna substrate can be easily reduced, and the electronic timepiece can also be easily miniaturized.

[0124] In the electronic timepiece disclosed herein, preferably, the width of the first antenna element and the second antenna element is greater than 0.5 mm, and the width of the first antenna element and the second antenna element is less than the height of the outer peripheral surface and the inner peripheral surface. Since the width of each antenna element is greater than 0.5 mm, the resistance value of the antenna element can be reduced, and the antenna gain can be improved.

[0125] In the electronic timepiece disclosed in the present invention, the inner circumferential surface may also include a first inner circumferential surface continuously arranged with the upper surface and a second inner circumferential surface arranged between the first inner circumferential surface and the bottom surface, the lower end of the first inner circumferential surface continuous with the second inner circumferential surface is inclined in a direction close to the central axis of the antenna substrate relative to the upper end continuous with the upper surface, and the second antenna element is continuously arranged on the first inner circumferential surface and the second inner circumferential surface.

[0126] Since the inner circumferential surface is composed of a first inner circumferential surface and a second inner circumferential surface, the first inner circumferential surface is inclined from the upper end toward the lower end close to the center axis. Therefore, a scale ring covering the antenna substrate can be set along the inclined first inner circumferential surface, which can improve the visibility of the dial.

[0127] In the electronic timepiece of the present disclosure, the height dimension of the antenna substrate may be greater than the width dimension of the antenna substrate.

[0128] If the height of the antenna substrate is greater than the width of the antenna substrate, that is, the cross section is long and narrow, the widths of the first antenna element and the second antenna element can be large, and the antenna gain can be improved.

[0129] In the electronic timepiece disclosed herein, the material of the antenna substrate may be any one of polyphenylene sulfide, liquid crystal polymer, and polycarbonate, and the first antenna element and the second antenna element may be formed by plating.

[0130] When the material of the antenna substrate is any one of polyphenylene sulfide, liquid crystal polymer, and polycarbonate, electroless plating can be easily performed and the relative dielectric constant can be increased, thereby making it suitable as an antenna substrate.

[0131] In the electronic timepiece disclosed in the present invention, a dial may be provided on the inner side of the antenna substrate, and a recessed portion for the fixing convex portion of the dial may be formed on the inner peripheral surface. Since the fixing convex portion of the dial is arranged in the recessed portion formed on the inner peripheral surface of the antenna substrate, the diameter of the antenna substrate can be reduced, the antenna body can be miniaturized, and the electronic timepiece can also be miniaturized.

[0132] In the electronic timepiece disclosed herein, preferably, the antenna substrate has a relative dielectric constant of 7 or more.

[0133] If the antenna base material is formed of a dielectric having a relative dielectric constant of 7 or more, a sufficient wavelength shortening effect can be obtained, and the antenna body can be miniaturized.

[0134] The electronic timepiece of the present disclosure may include a bezel disposed outside the antenna substrate, wherein at least a portion of the bezel is formed of a conductive material.

[0135] If a conductive material is used for a part of the bezel, the appearance of the electronic timepiece can be improved, and the sense of luxury can be enhanced.

[0136] In the electronic timepiece of the present disclosure, the antenna base may be covered with a scale ring made of synthetic resin.

[0137] By covering the antenna base with a synthetic resin scale ring, the design can be improved without hindering the antenna performance.

Claims

1. An electronic clock, comprising: The annular antenna substrate has an upper surface, an outer peripheral surface, a bottom surface, and an inner peripheral surface; A first antenna element, which is disposed on the outer peripheral surface; as well as A second antenna element is disposed on the inner peripheral surface, At least one of the first antenna element and the second antenna element includes a power supply terminal connected to a power supply unit. The distance between the first antenna element and the second antenna element is greater than 0 mm and less than 2 mm. The inner peripheral surface includes: a first inner peripheral surface provided continuously with the upper surface; and a second inner peripheral surface provided between the first inner peripheral surface and the bottom surface. The lower end of the first inner peripheral surface which is continuous with the second inner peripheral surface is inclined in a direction approaching the central axis of the antenna substrate relative to the upper end which is continuous with the upper surface. The second antenna element is continuously provided on the first inner peripheral surface and the second inner peripheral surface.

2. The electronic timepiece according to claim 1, wherein: The distance between the first antenna element and the second antenna element is greater than 0 mm and less than or equal to 1.5 mm.

3. The electronic timepiece according to claim 1 or 2, wherein: The width of the first antenna element and the second antenna element is greater than or equal to 0.5 mm and less than or equal to the height of the outer peripheral surface and the inner peripheral surface.

4. The electronic timepiece according to claim 1 or 2, wherein: The height dimension of the antenna substrate is greater than the width dimension of the antenna substrate.

5. The electronic timepiece according to claim 1 or 2, wherein: The material of the antenna substrate is any one of polyphenylene sulfide, liquid crystal polymer, and polycarbonate. The first antenna element and the second antenna element are formed by plating.

6. The electronic timepiece according to claim 1 or 2, wherein: The electronic timepiece includes a dial disposed inside the antenna substrate. A recessed portion is formed on the inner peripheral surface, and a protruding portion for fixing the dial is arranged in the recessed portion.

7. The electronic timepiece according to claim 1 or 2, wherein: The antenna substrate has a relative dielectric constant of 7 or more.

8. The electronic timepiece according to claim 1 or 2, wherein: The electronic timepiece includes a bezel disposed outside the antenna substrate, and at least a portion of the bezel is formed of a conductive material.

9. The electronic timepiece according to claim 1 or 2, wherein: The antenna substrate is covered with a scale ring made of synthetic resin.

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