JP2010048605A - Built-in antenna-type electronic timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a built-in antenna-type electronic timepiece which suppresses degradation of antenna characteristics with a simple structure. <P>SOLUTION: This radio wave correction timepiece 1 includes a metallic outer case 110, a metallic back cover 130 fitted to the rear-side opening of the outer case 110, an antenna 21 which is housed in the outer case 110 and receives external radio information, a receiving means for processing the external radio information received by the antenna 21, and a time display means for displaying time information. Between the outer case 110 and the back cover 130, a resin-made insulating ring 150 is interposed and arranged. The outer case 110 and the back cover 130 are fixed mutually by crimping the insulating ring 150 to each member, and are electrically insulated as the insulating ring 150 is interposed between them. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an antenna built-in electronic timepiece capable of receiving external wireless information by an antenna.

  Conventionally, an electronic timepiece with a built-in antenna such as a radio-controlled timepiece that receives external wireless information having time information from the outside by an antenna and performs processing such as time correction is known. In such an antenna built-in type electronic timepiece, when the antenna is arranged facing a metal case or back cover, there is a problem that eddy current is generated by the magnetic flux generated by the antenna and the reception characteristics of the antenna are deteriorated. On the other hand, the structure which reduces the influence by an eddy current is considered (for example, refer patent document 1, 2).

  In the electronic device described in Patent Document 1, the metal exterior portion that houses the antenna portion is configured by a metal body member and a metal back cover member, and these body members and the back cover member are bonded and fixed. The junction fixing part is not provided in a part facing the substantially central part of the antenna part or a part in the vicinity thereof. That is, in patent document 1, it is set as the structure which joins and fixes a trunk | drum member and a back cover member in a spot manner in multiple places.

  Moreover, the thing of patent document 2 is a metal case main body, the metal back cover attached to the back side of a case main body, and the case cover main body by screwing together to the internal peripheral surface of the said case main body. And a spacer member that is interposed between the case main body and the back cover and increases the insulation or electrical resistance therebetween.

International Publication Number WO2006 / 022433 Pamphlet JP 2008-32446 A

However, in Patent Document 1, since the body member and the back cover member must be spot-bonded and fixed at a plurality of locations, the structure of the body member and the back cover member becomes complicated, and processing and assembly work are complicated. There is a problem of becoming. For example, in the configuration shown in FIG. 11 of Patent Document 1, in the back cover member, it is necessary to provide the components to be joined to the body member except for the portion corresponding to the antenna portion.
For this reason, it is necessary to fix the component joined to the said trunk | drum member to several places on the upper surface of a back cover member by welding etc., the structure of a back cover member becomes complicated, and a process becomes complicated.
In addition, since the back cover member is fixed to the body member by a screw method, when the back cover member is screwed and fixed to the body member, the component joined to the body member is positioned at a portion facing the antenna portion. It is necessary to work with care so as not to reduce the assembly workability.

  In Patent Document 2, since it is necessary to separately provide a ring member for fixing the back cover to the case body and a spacer member for insulating the case body and the back cover, the number of parts is increased and assembly workability is increased. There is also a problem of lowering.

  In view of the above problems, an object of the present invention is to provide an antenna built-in electronic timepiece that can suppress deterioration of antenna characteristics with a simple configuration.

  An electronic timepiece with built-in antenna according to the present invention includes a metal exterior case, a metal back cover attached to an opening on the back side of the exterior case, and an antenna that is housed in the exterior case and receives external wireless information. An electronic timepiece with a built-in antenna comprising a receiving means for processing the external wireless information received by the antenna and a time display means for displaying time information, between the outer case and the back cover A resin insulating ring is sandwiched and arranged, and the outer case and the back cover are fixed to each other by crimping the resin insulating ring to each member, and the resin insulating ring is interposed to electrically It is characterized by being insulated.

The electronic timepiece with an antenna according to the present invention is electrically insulated by interposing a resin insulating ring between the metal outer case and the metal back cover, so that the eddy current loop is divided into small parts and the eddy current loss is reduced. Can be reduced. In particular, when an antenna in which an antenna coil is wound around a magnetic core is used as the antenna housed in the exterior case, a secondary magnetic path due to self-resonance is likely to occur. For this reason, an eddy current is generated by the secondary magnetic path in a metal exterior case or back cover provided around the antenna, and the reception characteristics of the antenna deteriorate. On the other hand, according to the present invention, by providing the resin insulating ring, the eddy current loop can be divided, and the eddy current loss can be reduced.
For this reason, even if a watch case made of a metal exterior case and back cover is used, the reception performance can be improved, the texture of the case can be improved, and the design can be improved.
In addition, since the resin insulation ring is sandwiched between the exterior case and the back cover, and the resin insulation ring is crimped to each exterior case and the back cover, a structure for fixing each member is adopted. In addition, there is no need to separately provide a fixing ring, the structure of the watch case can be simplified, and the assembly workability can be improved.

  In the electronic timepiece with built-in antenna according to the present invention, the back cover is configured to include a metal plate and a metal ring member having an opening to which the metal plate is attached, and the metal plate and the ring member. A resin insulating ring for back cover is interposed between the metal plate and the ring member, and the resin insulating ring for back cover is fixed to each member, and the back cover is fixed. It is preferable to be electrically insulated by interposing a resin insulating ring.

According to the present invention, since the back cover has a two-body structure of the metal plate and the ring member, and the resin insulating ring for the back cover is interposed between them, the loop of the eddy current in the back cover can be further divided, and the vortex Current loss can be further reduced.
In addition, the metal plate and ring member employ a structure that is fixed by crimping the resin insulation ring for the back cover sandwiched between the members to each member. Can also be improved.

  In the electronic timepiece with built-in antenna according to the present invention, the exterior case includes a metal case and a metal glass edge, and the resin insulation for the case is provided between the case and the glass edge. The case and the glass rim are fixed to each other when the case insulating resin ring is crimped to each member, and the case resin insulating ring is interposed between the ring and the glass rim. It is preferable to be insulated.

According to the present invention, since the outer case has a two-body structure of the trunk and the glass edge and the resin insulating ring for the case is interposed between them, the eddy current loop in the outer case can be further divided, and the eddy current loss Can be further reduced.
In addition, since the case and the glass edge are fixed by pressing the resin insulation ring for the case sandwiched between the members to each member, the structure of the exterior case can be simplified and the assembly workability is also improved. It can be improved.

  Further, in the electronic timepiece with built-in antenna according to the present invention, the time display means includes a time display unit for displaying time and a clock circuit unit for controlling the operation of the time display unit, and the power supply terminal of the clock circuit unit Is preferably electrically connected to at least one of the outer case and the back cover by a conductive spring.

  When the watch case is composed of a plurality of members and the members are insulated from each other, the antistatic property is deteriorated. However, in the present invention, the power supply terminal of the watch circuit portion is electrically connected to the exterior case or the back cover by a conductive spring. As a result, the antistatic performance can be improved. For this reason, it is possible to use a CPU or the like that is manufactured by a fine process and can be driven with low power, and power saving can be realized.

In the electronic timepiece with built-in antenna according to the present invention, it is preferable that the conductive spring is provided at a position separated from the antenna by a predetermined length or more.
In other words, if a conductive spring that connects the power supply terminal of the watch circuit part to a metal outer case or back cover is placed close to the antenna, an eddy current flows through the conductive spring, and the reception characteristics of the antenna are improved. Affect.
On the other hand, if the conductive spring is arranged away from the antenna by a predetermined length or more, the influence of the eddy current can be reduced and the reception characteristic of the antenna can be improved.
The predetermined length may be a length that can reduce the influence of eddy currents caused by the sub magnetic path of the antenna. For example, if the plane of the watch is divided into two by a line that passes through the central axis of the watch (for example, a line connecting the clock at 12 o'clock and 6 o'clock), an antenna is placed in one area and a conductive spring is placed in the other area Thus, a conductive spring may be disposed at a position away from the antenna by a predetermined length.

  In the electronic timepiece with built-in antenna of the present invention, the back cover is configured to include a metal plate and a metal ring member having an opening to which the metal plate is attached, and the metal plate and the ring member. A resin insulating ring for back cover is interposed therebetween, and the metal plate and the ring member are fixed to each other by the resin insulating ring for back cover being crimped to each member, and the back cover The insulating case is electrically insulated by interposing a resin insulating ring, and the outer case is configured to include a metal barrel and a metal glass edge, and the case is between the barrel and the glass edge. An insulating resin ring for sandwiching is disposed, and the case and the glass edge are fixed to each other when the insulating resin ring for case is crimped to each member, and the insulating resin ring for case is interposed By Manner insulated power supply terminal of the clock circuit section, it is preferable that the electrically conductive by conductive spring to the metal plate of the body and the back cover of the outer case.

  According to the present invention, the exterior case is constituted by the case and the glass edge, the back cover is constituted by the metal plate and the ring member, and the power supply terminal of the timepiece circuit unit is electrically connected to the case and the metal plate through the conductive spring. ing. For this reason, since the power supply terminal can be conducted to a part having a large volume among the metal parts constituting the watch case, the antistatic performance can be improved as compared with the case where the power supply terminal is conducted to the glass edge or the ring member.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
FIG. 1 is a front view of a radio wave correction timepiece 1 as an electronic timepiece with a built-in antenna according to the present embodiment.

The radio-controlled timepiece 1 is a pointer-type electronic timepiece (analog timepiece) including an hour hand 11, a minute hand 12, a second hand 13 (hands 11 to 13) and a dial plate 14.
The radio-controlled timepiece 1 further includes a module 10 (see FIG. 2) in which various configurations for controlling the driving of the antenna 21 and the hands 11 to 13 that receive a standard radio wave, the hands 11 to 13, A watch case 100 that houses the plate 14, the module 10, and the like therein is provided. The radio-controlled timepiece 1 is provided with a crown 81 and a button 82 as the external input device 8.
Such a radio-controlled timepiece 1 is provided with an antenna 21 to receive a long-wave standard radio wave as external wireless information having time information. Based on the received time information, the hour hand 11, the minute hand 12, and the second hand 13 The indicated position can be automatically corrected.

[Module configuration]
A module 10 constituting the radio-controlled timepiece 1 will be described with reference to FIGS.
2 is a schematic cross-sectional view of the radio-controlled timepiece 1, FIG. 3 is a diagram of the radio-controlled timepiece 1 viewed from the back side with the back cover removed, and FIG. 4 shows a schematic configuration of the radio-controlled timepiece 1. It is a block diagram.

The module 10 has a module middle frame 90 made of a synthetic resin and having a substantially cylindrical shape. A plurality of protrusions (not shown) that contact the inner peripheral surface of the watch case 100 in the radial direction are formed on the side surface of the module middle frame 90, and these protrusions are formed on the inner periphery of the watch case 100. It is arranged along the surface.
When the module 10 is housed in the watch case 100, the position of the module 10 is fixed by abutting each protrusion provided on the module middle frame 90 with the inner surface of the watch case 100.

  Further, the module 10 includes a circuit board 80 to which a receiving IC, a CPU, a crystal resonator, and the like are attached, a motor 411, 421 constituting a part of the driving means 4, a wheel train, and the like (movement). Each component such as a high-capacity secondary power source (secondary battery) 72 constituting the power supply means 7 is incorporated. Further, the antenna 10 for receiving radio waves is incorporated in the module 10 at a position close to the watch case 100.

As shown in FIGS. 2 and 3, conductive springs 84 and 85 that are electrically connected to the power supply terminals of the circuit board 80 are provided on the circuit holding plate 83 of the circuit board 80 incorporated in the module 10.
Two conductive springs 84 are provided, each extending outward from the outer peripheral surface of the circuit board 80 and in contact with a body 111 of an exterior case 110 described later.
The conductive spring 85 extends from the back surface of the circuit board 80 toward the back cover side and is in contact with a metal plate 131 of the back cover 130 described later.
Further, each of the conductive springs 84 and 85 is provided on the 3 o'clock side with respect to the antenna 21 arranged on the 9 o'clock side of the timepiece, with respect to a line connecting 12 o'clock and 6 o'clock of the timepiece. That is, when the timepiece plane is divided into two by a line passing through the central axis of the timepiece, the antenna 21 is arranged in one area, and the conductive springs 84 and 85 are arranged in the other area. For this reason, the conductive springs 84 and 85 are arranged at positions away from the antenna 21 by a length longer than the length that can reduce the influence of eddy current.

  As shown in FIG. 4, the circuit board 80 includes a receiving unit 2 that processes received radio waves, a drive control circuit unit 3, a driving unit 4 that drives a pointer, a counter unit 6 that counts time, Are provided as various circuit configurations. Each circuit provided on the circuit board 80 constitutes a timepiece circuit unit.

  The receiving means 2 includes an antenna 21 that receives radio waves, a tuning circuit portion 22 that is configured by a capacitor and tuned to the radio waves received by the antenna 21, a reception circuit portion 23 that processes information received by the antenna 21, and a reception A time data storage circuit unit 24 that stores time data processed by the circuit unit 23 is provided.

FIG. 5 is a block diagram showing the configuration of the receiving circuit unit of the radio-controlled timepiece 1.
As shown in FIG. 5, the tuning circuit unit 22 includes two capacitors 22A and 22B connected in parallel to the antenna 21, and one capacitor 22B is connected to the antenna 21 via a switch 22C. Has been.
The frequency of the radio wave received by the antenna 21 is switched by turning on or off the switch 22C according to a frequency switching control signal output from the drive control circuit unit 3. As a result, for example, in Japan, two types are output from the standard radio wave output station of Otakado and Mt. (East Japan) with a transmission frequency of 40 kHz and the standard radio wave output station of Mt. Hagane (West Japan) with a transmission frequency of 60 kHz. It is configured to be able to switch and receive a long wave standard radio wave having a frequency of.

  These capacitors 22A and 22B are provided on an antenna circuit board 220 provided on the antenna 21, as shown in FIG. The antenna circuit board 220 is provided with seven capacitors including the capacitors 22A and 22B (not shown). Then, by switching the connection of these capacitors with the antenna, it is possible to switch to three types of frequencies of 40 kHz, 60 kHz, and 77.5 kHz. At this time, two or three capacitors per frequency are connected in parallel so as to perform accurate frequency tuning, and are switched by a switch.

As shown in FIG. 5, the receiving circuit unit 23 amplifies the long wave standard radio signal received by the antenna 21, and a band pass filter that extracts only a desired frequency component from the amplified long wave standard radio signal. 232, a demodulation circuit 233 for smoothing and demodulating the long wave standard radio signal, an AGC (Automatic Gain Control) circuit 234 for controlling the gain of the amplification circuit 231 and controlling the reception level of the long wave standard radio signal to be constant, And a decoding circuit 235 that decodes and outputs the demodulated long-wave standard radio signal.
The time data received and signal-processed by the receiving circuit unit 23 is output and stored in the time data storage circuit unit 24 as shown in FIG.
The reception circuit unit 23 starts receiving time information based on a reception control signal output from the drive control circuit unit 3 by a preset schedule, a forced reception operation by the external input device 8, or the like.

  As shown in FIG. 4, a pulse signal from the pulse synthesis circuit 31 is input to the drive control circuit unit 3. The pulse synthesizing circuit 31 divides a reference pulse from a reference oscillator 311 such as a crystal oscillator to generate a clock pulse, and generates a pulse signal having a different pulse width and timing from the reference pulse. The reference vibrator 311 is connected to the CPU and becomes a clock signal of the circuit. However, since the frequency is close to the long wave reception frequency and the signal may be mixed as noise into the antenna 21, the reference vibrator 311 is separated from the antenna 21. Are arranged.

The drive control circuit unit 3 outputs a second drive pulse signal PS1 that is output once per second to drive the second hand 13, and an hour / minute drive pulse signal PS2 that is output once per minute to drive the hour / minute hands 11 and 12. Output to each second drive circuit 41 and hour / minute drive circuit 42 to control the driving of the hands. That is, each drive circuit 41, 42 drives a second motor 411 and an hour / minute motor 421 including a stepping motor driven by a pulse signal from each drive circuit 41, 42, and is thereby connected to each motor 411, 421. The second hand 13, the minute hand 12 and the hour hand 11 are driven.
The hands 11 to 13, the dial 14, the motors 411 and 421, and the drive circuits 41 and 42 constitute a time display unit that displays the time. As the time display unit, the hour hand 11, the minute hand 12, and the second hand 13 may be driven by one motor.

In the present embodiment, as shown in FIG. 3, the second motor 411 is disposed between the central axis of the timepiece and the antenna 21 in a plan view. The second motor coil 411 </ b> A of the second motor 411 is disposed in a notch portion of the circuit pressing plate 83.
The hour / minute motor 421 is disposed between the central axis of the timepiece and the conductive spring 85 in a plan view. The hour / minute motor coil 421 </ b> A of the hour / minute motor 421 is disposed in the opening portion of the circuit pressing plate 83.
Furthermore, when providing the calendar motor 431 for driving the date dial or the like, it may be disposed between the conductive spring 84 at the 5 o'clock position of the timepiece and the central axis of the timepiece in a plan view. The calendar motor coil 431A of the calendar motor 431 may also be disposed in the opening portion of the circuit pressing plate 83.

The counter unit 6 includes a second counter circuit unit 61 that counts seconds and an hour / minute counter circuit unit 62 that counts hours and minutes.
The second counter circuit unit 61 includes a second position counter 611, a second time counter 612, and a coincidence detection circuit 613. The second position counter 611 and the second time counter 612 are both 60 counts, that is, a counter that loops in 60 seconds when a 1 Hz signal is input. The second position counter 611 counts the drive pulse signal (second drive pulse signal PS1) supplied from the drive control circuit unit 3 to the second drive circuit 41. That is, the position of the second hand indicated by the second hand is counted by counting the drive pulse signal for driving the second hand.
The second time counter 612 normally counts a 1 Hz reference pulse signal (clock pulse) output from the drive control circuit unit 3. When the time data is received by the receiving means 2, the counter value is corrected according to the second data of the time data.

Similarly, the hour / minute counter circuit unit 62 includes an hour / minute position counter 621, an hour / minute time counter 622, and a coincidence detection circuit 623. Both the hour / minute position counter 621 and the hour / minute time counter 622 are counters that loop when signals for 24 hours are input. The hour / minute position counter 621 counts the drive pulse signal (hour / minute drive pulse signal PS2) supplied from the drive control circuit unit 3 to the hour / minute drive circuit 42, and counts the position of the hour / minute hands indicated by the hour hand and minute hand. is doing.
The hour / minute time counter 622 normally counts 1 Hz pulses (clock pulses) output from the drive control circuit unit 3 (more precisely, 1 count is obtained when 1 Hz is counted 60 times). When the time data is received by the receiving means 2, the counter value is corrected according to the hour / minute data of the time data.

The coincidence detection circuits 613 and 623 detect the coincidence of the count values of the position counters 611 and 621 and the time counters 612 and 622 and output a detection signal indicating whether or not they coincide to the drive control circuit unit 3. To do.
When the mismatch signal is input from the match detection circuits 613 and 623, the drive control circuit unit 3 continues to output the drive pulse signals PS1 and PS2 until the match signal is input. For this reason, during normal hand movement, when the counter values of the time counters 612 and 622 are changed by the reference signal of 1 Hz from the drive control circuit unit 3 and do not coincide with the position counters 611 and 621, the drive pulse signals PS1 and PS2 are As each pointer is output and moved, the position counters 611 and 621 coincide with the time counters 612 and 622. By repeating this operation, normal hand movement control is performed.
When the time counters 612 and 622 are corrected with the received time data, the drive pulse signals PS1 and PS2 are continuously output until the counter values of the position counters 611 and 621 coincide with the counter values. Is fast-forwarded and corrected to the correct time.
Accordingly, the driving control circuit unit 3, the counter unit 6, and the pulse synthesis circuit 31 constitute a clock circuit unit that controls the operation of the time display unit. The clock circuit section and the time display section constitute time display means.

The power supply means 7 includes a power generator 71 as a power generator configured by a self-winding generator, a solar battery (solar generator), and the like, and a high-capacity secondary power source 72 that stores power generated by the power generator 71. It is configured with. In the present embodiment, as shown in FIG. 2, a solar panel 74 is disposed on the back side of the dial 14 to form a power generator 71.
The high-capacity secondary power source 72 can use a secondary battery such as a lithium ion battery. As the power supply means 7, a primary battery such as a silver battery may be used. Further, the high-capacity secondary power source 72 is formed of a stainless steel case, and in order to suppress the influence on the antenna characteristics, as shown in FIG. It is arranged at the position.

  The external input device 8 as an external input means includes a crown 81 and a button 82, and is used for performing a receiving operation, time adjustment, and the like.

  The antenna 21 includes a magnetic core 211 and an antenna coil 212 wound around the magnetic core 211. As shown in FIG. 1, the antenna 21 is arranged in the module middle frame 90 in parallel with the direction connecting the clock at 12 o'clock and 6 o'clock, and the rotation shaft of each pointer is provided. It is arranged at a position that is at 9 o'clock with respect to the center position of the watch.

  The magnetic core 211 is formed by, for example, punching a cobalt-based amorphous foil (eg, amorphous foil of Co 50 wt% or more) with a mold, or bonding about 10 to 30 pieces formed by etching, and superimposing, annealing, etc. To stabilize the magnetic characteristics. That is, the magnetic core 211 is configured by laminating planar amorphous foils in the thickness direction of the watch. Note that the magnetic core 211 is not limited to the laminated amorphous foil, and ferrite may be used. In this case, the magnetic core 211 may be formed by a mold or the like and heat-treated.

  The antenna coil 212 requires an inductance value of about 10 mH when receiving long-wave standard radio waves (40 to 77.5 kHz). For this reason, in this embodiment, the antenna coil 212 is configured by winding a uremet wire having a diameter of about 0.1 μm for several hundred turns.

The antenna 21 resonates in parallel by the antenna coil 212 and capacitors 22A and 22B connected to the antenna coil 212, thereby increasing the induced voltage due to the external magnetic flux.
The antenna 21 and the receiving IC are connected by two wires. That is, the antenna 21 and the receiving IC are electrically connected by taking out the antenna coil 212 from the antenna end and soldering it to the circuit board 80. As a result, the standard radio wave received by the antenna 21 can be output to the receiving means 2. The electrical connection may be performed by attaching a flexible substrate made of polyimide or the like to the antenna 21 and screwing the substrate to the circuit board 80.

[Configuration of watch case]
Next, the configuration of the watch case 100 of the radio-controlled timepiece 1 will be described.
As shown in FIG. 2, the watch case 100 has an outer case 110 formed in a substantially cylindrical shape, a cover glass 120 attached to an opening on the front side of the outer case 110, and an opening on the back side of the outer case 110. And a back cover 130 attached thereto.

[Configuration of exterior case]
The outer case 110 includes a metal barrel 111 and a metal glass edge 115. For example, various materials such as titanium, brass, stainless steel, and aluminum can be used as the material of the body 111 and the glass edge 115.

  The body 111 is formed in a substantially cylindrical shape, and a concave portion 112 is formed on the surface thereof along the inner periphery of the body 111 as shown in FIG. The body 111 is formed with a through hole 113 through which the winding stem 81A of the crown 81 is inserted.

  The glass edge 115 includes a holding portion 116 that holds the cover glass 120 and an insertion portion 117 that is inserted into the inner peripheral side of the body 111. The cover glass 120 may be fixed to the holding portion 116 with an adhesive, or may be fixed with a packing material (not shown) interposed.

  A case resin insulating ring 151 is disposed in the recess 112 of the barrel 111. The case insulating resin ring 151 is a plastic ring material. When the case resin insulation ring 151 is attached to the outer peripheral surface of the insertion portion 117 and the insertion portion 117 is inserted into the body 111 and pushed in, the case resin insulation ring 151 is disposed in the recess 112 portion. Then, it is deformed and crimped to the barrel 111 and the glass edge 115. For this reason, the trunk | drum 111 and the glass edge 115 are being fixed mutually by the resin insulating ring 151 for cases being inserted | pinched between and crimped | bonded.

[Configuration of back cover]
As shown in FIG. 7, the back cover 130 includes a metal plate 131 and a metal ring member 135. The metal plate 131 and the ring member 135 can be made of various metals such as titanium, brass, stainless steel, and aluminum.

The metal plate 131 is formed in a disc shape.
The ring member 135 is formed in a substantially annular shape, and as shown in FIG. 6, a protrusion (protrusion) 136 that protrudes toward the inner peripheral side of the ring member 135 is formed on the inner peripheral surface thereof. Further, on the upper surface of the ring member 135, a protrusion 137 is formed that protrudes upward (on the cover glass 120 side) and is provided in an annular shape along the inner periphery of the body 111.

  A back cover resin insulating ring 152 is disposed between the outer peripheral surface of the metal plate 131 and the inner peripheral surface of the ring member 135. The resin insulation ring 152 for the back cover is also the same plastic ring material as the resin insulation ring 151 for the case. The metal plate 131 is inserted into the opening of the ring member 135 with the back cover resin insulating ring 152 attached to the outer peripheral surface of the metal plate 131 until the metal plate 131 comes into contact with the protrusion 136. When pushed, the resin insulating ring 152 for the back cover is disposed between the ring member 135 and the protrusion 136 and deforms, and is crimped to the ring member 135 and the protrusion 136. For this reason, the ring member 135 and the protrusion 136 are fixed to each other by the resin insulating ring 152 for back cover being sandwiched between and crimped.

[External case and back cover fixing structure]
The exterior case 110 and the back cover 130 configured as described above are fixed to each other by a resin insulating ring 150 sandwiched between the exterior case 110 and the back cover 130.
The resin insulating ring 150 is a plastic ring material like the rings 151 and 152. Then, with the resin insulating ring 150 attached to the outer peripheral surface of the protrusion 137 of the ring member 135, the back cover 130 is inserted into the opening on the back surface of the barrel 111, and the protrusion 136 contacts the lower surface of the barrel 111. When pushed in to the position, the resin insulating ring 150 is disposed between the projection 136 and the barrel 111 and deforms, and is crimped to the projection 136 and the barrel 111. For this reason, the back cover 130 and the outer case 110 are fixed to each other by the resin insulating ring 150 being sandwiched between and crimped.

In addition, as a material of each resin insulation ring 150, 151, 152, for example, POM (also called polyoxymethylene: polyoxymethylene, polyacetal, acetal resin, crystallinity mainly composed of (—CH ₂ O—) structural units. Can be used.
In addition, each of the resin insulating rings 150, 151, and 152 also functions as a waterproof packing, and ensures the waterproof property of the radio-controlled timepiece 1.

[Magnetic flux flow in radio-controlled watches]
FIG. 8 shows the flow of magnetic flux in the radio-controlled timepiece 1 having such a structure. In the radio-controlled timepiece 1, the timepiece case 100 including the exterior case 110 and the back cover 130 is made of metal. Then, the magnetic flux 214 from the outside of the watch based on the radio wave penetrates the magnetic core 211 of the antenna 21 while avoiding the metal watch case 100.
Then, a magnetic flux (sub magnetic path) 215 generated by the self-resonance of the antenna 21 is also generated as shown in FIG. When self-resonating in this way, the magnetic flux density of the antenna 21 and the secondary magnetic path 215 formed around the antenna 21 is increased, and the reception performance is improved. However, the metal around the antenna 21 is easily affected by the eddy current. Here, the eddy current flows through the metal outer case 110 and the back cover 130 in such a direction as to cancel the magnetic flux in the sub magnetic path 215 by electromagnetic induction. This eddy current loss is expressed by Equation 1 below.

Here, Pe: eddy current loss, t: iron plate thickness, f: frequency, Bm: maximum magnetic flux density, ρ: resistivity of magnetic material, ke: proportionality constant.
As shown in the above formula 1, the larger the thickness and size of the watch case 100, the larger the eddy current loss and the larger the eddy current loss. Therefore, if the members constituting the watch case 100 are insulated, the eddy current loop is also divided into small parts, so that the loss is reduced.

  That is, in this embodiment, the resin insulating ring 150 is disposed between the outer case 110 and the back cover 130. Further, the exterior case 110 has a two-body structure of a barrel 111 and a glass edge 115, and a resin insulating ring 151 for case is disposed between each barrel 111 and the glass edge 115. Further, the back cover 130 has a two-body structure of a metal plate 131 and a ring member 135, and a resin insulation ring 152 for the back cover is disposed between the metal plate 131 and the ring member 135.

Therefore, the metal watch case 100 is electrically insulated by the insulating rings 150 to 152 into four members: the case 111, the glass edge 115, the metal plate 131, and the ring member 135. For this reason, as shown in FIG. 9, the loop of the eddy current generated in each member is divided into small pieces, and the eddy current loss is also reduced.
On the other hand, as shown in FIG. 10, when the exterior case 110 </ b> A and the back cover 130 </ b> A are fixed with a screw structure, the contact pressure between the members increases and the high-frequency resistance also decreases. For this reason, the loop of the eddy current generated in each member becomes large, and the eddy current loss also increases.

  In the present embodiment, the metal portions are partially in contact with each other even in the portions insulated by the insulating rings 150 to 152. However, the contact pressure between each of the insulating rings 150 to 152 and the metal member is large, but between each metal member, that is, between the barrel 111 and the glass edge 115, between the metal plate 131 and the ring member 135, and between the barrel 111 and the ring member 135. The contact pressure is lower than that in the case where the screw structure is fixed and the contact area is small, so that the high-frequency resistance is increased, and the eddy current loss can be reduced as compared with the case where the screw structure is fixed.

[Effects of radio-controlled clock]
As described above, since the radio-controlled timepiece 1 of the above embodiment is electrically insulated by interposing the resin insulating ring 150 between the metal outer case 110 and the back cover 130, these members have a screw structure. Compared with the case of joining, eddy current loss can be reduced and reception performance can be improved. For this reason, even if it uses the metal exterior case 110 and the back cover 130, reception performance can be ensured and design property can also be improved.

In addition, since the outer case 110 has a two-body structure of the body 111 and the glass edge 115 and the resin insulating ring 151 for case is interposed between them, the eddy current loss in the outer case 110 can be further reduced.
Furthermore, since the back cover 130 has a two-body structure of the metal plate 131 and the ring member 135 and the back cover resin insulating ring 152 is interposed between them, the eddy current loss in the back cover 130 can be further reduced.

  Further, since the body 111, the glass edge 115, the metal plate 131, and the ring member 135 are fixed to each other by adopting a structure in which the insulating rings 150 to 152 are sandwiched and fixed, as in Patent Document 2, the insulation is performed. It is not necessary to separately provide a fixing ring in addition to the member for use, the structure of the watch case 100 can be simplified, and the assembly workability can be improved.

Furthermore, when the watch case 100 is composed of a plurality of members and the members are insulated from each other, the antistatic property is deteriorated. In particular, in the case of the timepiece 1 having the solar panel 74 as in the present embodiment, the CPU and the like are manufactured by a fine process for low power, and the antistatic performance is not so high. When such a CPU with low power consumption is used, in order to improve the antistatic property, it is preferable to connect to a component with a large volume among a plurality of external metal components because the charge is easily released. Therefore, in the present embodiment, the power supply terminal of the circuit board 80 is electrically connected to the body 111 which is a component having a larger volume than the glass edge 115 in the exterior case 110 by the conductive spring 84, and the back cover is covered by the conductive spring 85. In 130, since it is electrically connected to the metal plate 131 which is a component having a larger volume than the ring member 135, the anti-static performance can be improved.
In addition, although the antistatic performance improves as the number of conductive portions increases, in the present embodiment, two conductive springs 84 are provided for the body 111 and are conductive at two locations, so only one location is provided. Thus, the antistatic performance can be improved as compared with the case where the body 111 is made conductive.
Further, since each of the conductive springs 84 and 85 is provided at a position distant from the antenna 21, the influence of eddy current can be further reduced and reception performance can be improved.
In addition, since the contact area between each of the conductive springs 84 and 85 and the body 111 and the metal plate 131 is small, the influence of eddy current due to the contact of the conductive springs 84 and 85 is small, and reception performance can be improved in this respect as well. .

Further, since the back cover 130 can be press-fitted and fixed to the opening on the back side of the barrel 111 with the resin insulating ring 152 for the back cover interposed, the back cover 130 can be rotated as in the case of the screw structure. There is no need to install it. For this reason, since the direction of the back cover 130 can be fixed, when characters and designs are provided on the back cover 130, the characters and designs can be set in a predetermined direction, and the design can be improved.
Furthermore, it is not necessary to process the thread as compared with the screw structure back cover, and there is an advantage that the processing cost is reduced accordingly.

[Other embodiments]
It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

For example, in the above-described embodiment, the outer case 110 has a two-body structure including the body 111 and the glass edge 115, but an outer layer case having an integral structure may be used. Similarly, the back cover 130 has a two-body structure of the metal plate 131 and the ring member 135, but a back cover with an integral structure may be used.
Moreover, in the said embodiment, although the metal plate 131 was formed in the planar circular disk shape, you may form in a planar polygonal plate shape. In this case, the planar shape of the opening of the ring member 135 may be formed in accordance with the planar shape of the metal plate 131. In this way, the design of the back cover 130 can be improved by setting the shape of the metal plate 131 in various ways.

  In the above embodiment, the conductive springs 84 and 85 are provided and the power supply terminal of the timepiece circuit unit is electrically connected to the case 111 and the metal plate 131. However, the conductive springs 84 and 85 are not provided. Good. However, since the anti-static property can be improved by providing the conductive springs 84 and 85 as in the above embodiment, the conductive springs 84 and 85 are provided in a small device such as a wristwatch that requires power saving. It is preferable to provide it.

The present invention is not limited to a long wave radio timepiece that receives standard radio waves, but may be used for short-range wireless communication applications such as keyless entry that uses radio waves of 125 kHz or 13.56 MHz.
Furthermore, the antenna 21 is not limited to the antenna core 212 wound around the magnetic core 211, and may be a coreless antenna or the like. That is, an antenna corresponding to the type of radio wave to be received may be used.

  In addition, the specific structure and procedure for carrying out the present invention can be appropriately changed to other structures and the like within a range in which the object of the present invention can be achieved.

It is a front view of a radio wave correction timepiece as an electronic timepiece with built-in antenna according to the present embodiment. It is a sectional side view when it cuts in the thickness direction of the radio wave correction timepiece of the embodiment. It is a top view which shows schematic structure which looked at the electromagnetic wave correction timepiece of the said embodiment from the back cover side. It is a block diagram which shows schematic structure of the electromagnetic wave correction timepiece of the said embodiment. It is a block diagram which shows the structure of the receiving circuit part of the electromagnetic wave correction timepiece of the said embodiment. It is an expanded sectional view which shows the structure of the timepiece case of the radio wave correction timepiece of the embodiment. It is a perspective view which shows the structure of the back cover of the said embodiment. FIG. 4 is a diagram schematically showing a sub magnetic path generated when a radio wave is received by an antenna in the radio wave correction timepiece of the embodiment. It is the figure which showed typically the eddy current which generate | occur | produces with the radio wave correction timepiece of the said embodiment. It is the figure which showed typically the eddy current which generate | occur | produces with the timepiece of the comparative example of the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Radio wave correction clock, 2 ... Receiving means, 10 ... Module, 21 ... Antenna, 80 ... Circuit board, 83 ... Circuit holding plate, 84, 85 ... Conductive spring, 100 ... Clock case, 110 ... Exterior case, 111 ... 115, glass edge, 120, cover glass, 130, back cover, 131, metal plate, 135, ring member, 150, resin insulating ring, 151, resin insulating ring for case, 152, resin for back cover Insulating ring, 214 ... magnetic flux, 215 ... sub magnetic path.

Claims (6)

A metal outer case,
A metal back cover attached to the opening on the back side of the outer case;
An antenna housed in the exterior case and receiving external wireless information;
Receiving means for processing the external wireless information received by the antenna;
An electronic timepiece with a built-in antenna comprising a time display means for displaying time information,
Between the outer case and the back cover, a resin insulating ring is sandwiched and arranged,
The antenna is characterized in that the exterior case and the back cover are fixed to each other by crimping the resin insulating ring to each member and electrically insulated by interposing the resin insulating ring. Built-in electronic clock. The electronic watch with a built-in antenna according to claim 1,
The back cover includes a metal plate and a metal ring member having an opening to which the metal plate is attached.
Between the metal plate and the ring member, a resin insulating ring for back cover is sandwiched and arranged,
The metal plate and the ring member are fixed to each other by crimping the resin insulating ring for back cover to each member, and are electrically insulated by interposing the resin insulating ring for back cover. An electronic timepiece with a built-in antenna. In the electronic timepiece with a built-in antenna according to claim 1 or 2,
The exterior case includes a metal barrel and a metal glass edge,
Between the barrel and the glass edge, a case insulating resin ring is sandwiched and arranged,
The case and the glass edge are fixed to each other by crimping the case resin insulation ring to each member, and electrically insulated by interposing the case resin insulation ring. An electronic watch with a built-in antenna. In the electronic timepiece with a built-in antenna according to any one of claims 1 to 3,
The time display means includes a time display unit for displaying time, and a clock circuit unit for controlling the operation of the time display unit,
The power supply terminal of the timepiece circuit unit is electrically connected to at least one of the exterior case and the back cover by a conductive spring. The electronic watch with a built-in antenna according to claim 4,
The electronic timepiece with a built-in antenna, wherein the conductive spring is provided at a position separated from the antenna by a predetermined length or more. In the electronic timepiece with a built-in antenna according to claim 4 or 5,
The back cover includes a metal plate and a metal ring member having an opening to which the metal plate is attached, and a resin insulating ring for back cover is sandwiched between the metal plate and the ring member. The metal plate and the ring member are fixed to each other by crimping the resin insulating ring for the back cover to each member, and electrically connected by the resin insulating ring for the back cover. Insulated and
The exterior case is configured to include a metal barrel and a metal glass edge, and a resin insulating ring for case is interposed between the barrel and the glass edge. The edges are fixed to each other by crimping the resin insulating ring for case to each member, and electrically insulated by interposing the resin insulating ring for case,
The power supply terminal of the timepiece circuit unit is electrically connected to the body of the exterior case and the metal plate of the back cover by a conductive spring.

Images