JP2005062163A - Electronic clock with built-in antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic timepiece with a built-in antenna capable of improving the appearance design of an exterior case, reducing the manufacturing cost, and realizing downsizing.
A radio wave correction timepiece (1) includes an outer case (9) and an antenna (21) disposed in the outer case (9). The antenna 21 includes a core 211 and a coil 212 wound around the core 211. At least both end portions 211 </ b> A of the core 211 are arranged along the inner peripheral surface 91 </ b> A of the exterior case 9. Since the end surface 211B of the core 211 is not opposed to the inner peripheral surface 91A, even if the antenna 21 is disposed close to the metal case 9, it is possible to prevent deterioration of the antenna characteristics. For this reason, since the case 9 can be made of metal and the appearance design can be improved, and it is not necessary to form a notch in the case, the manufacturing cost can be reduced and the timepiece 1 can be miniaturized.
[Selection] Figure 4

Description

  The present invention relates to an antenna built-in type electronic timepiece represented by a radio-controlled timepiece that receives external wireless information including time information and performs processing such as time correction.

An electronic timepiece with a built-in antenna such as a radio-controlled timepiece that receives time information from the outside and corrects the time is known (see, for example, Patent Document 1).
In this electronic timepiece with built-in antenna, an antenna is housed in a first watch case made of a non-conductive material such as plastic, and the first watch case is covered with a second watch case made of a metal material. A notch is formed in a part of the watch case 2 and the loop opening surface of the antenna is opposed to the notch so that radio waves can be received by the antenna without being blocked by the metal case.

JP 2003-161788 A

However, in such a timepiece, the surface of the timepiece can be made of metal and can have a high-quality appearance, while two types of cases having different first and second materials are required, In addition, a notch portion must be formed in a non-conductive case such as plastic, which has a problem that the manufacturing process becomes complicated and the manufacturing cost increases.
An electronic watch with a built-in antenna whose watch case is made of plastic is also known, but in this case, the design of the watch surface is lower than when a metal case is used, and there is a problem that it lacks a sense of quality. is there.
Furthermore, it is conceivable that the watch case is made of metal and a rod-shaped general antenna as disclosed in Patent Document 1 is arranged in the case. In this case, however, there is a problem that the watch case becomes large. is there. That is, when the core end surface of the antenna is brought close to the inner peripheral surface of the case, the radio wave is attenuated by the metal case, so that the reception sensitivity of the antenna is lowered. For this reason, the core end surface of the antenna must be arranged away from the inner peripheral surface of the case. On the other hand, it is necessary to ensure the minimum length of the antenna depending on the type of radio wave to be received. Therefore, since the antenna having a predetermined length is disposed in the watch case away from the inner peripheral surface of the case, there is a problem that the watch case is enlarged accordingly.

Such a problem is not limited to the radio-controlled timepiece, and is a problem common to various electronic timepieces with a built-in antenna for wireless communication.
An object of the present invention is to provide an antenna built-in type electronic timepiece that can improve the appearance design of an exterior case, can reduce the manufacturing cost, and can be downsized.

  The antenna built-in type electronic timepiece of the present invention includes an exterior case at least partially made of metal, an antenna that is disposed in the exterior case and receives external wireless information, and processes external wireless information received by the antenna. Receiving means and time display means, and the antenna is constituted by a core and a coil wound around the core, and at least both ends of the core are arranged along the inner peripheral surface of the outer case. It is characterized by.

  Here, both ends of the core are arranged along the inner peripheral surface of the outer case. When the inner peripheral surface of the outer case is circular, the axial direction of both ends of the core is adjacent to both ends of the core. When the inner peripheral surface of the outer case is substantially parallel and the inner peripheral surface of the outer case is polygonal, the axial direction of both ends of the core and the inner peripheral surface of the outer case adjacent to both ends of the core are It means that it is substantially parallel. Further, “substantially parallel” is not limited to the case of being completely parallel, that is, the case where the crossing angle in each direction is 0 degree, and includes that the crossing angle is within a range of ± 30 degrees with respect to 0 degree. In short, “substantially parallel” means that the axial direction of both ends of the core faces the case inner peripheral surface adjacent to both ends of the core so that the magnetic field component of the radio wave interlinking the core is not affected by the case inner peripheral surface. It means that they are arranged at an angle.

In the present invention, at least both ends of the core are disposed along the inner peripheral surface of the outer case, that is, the end surface of the core does not face the inner peripheral surface of the outer case. Even if at least a part is made of metal, the antenna arranged in the case can be arranged close to the metal part of the outer case.
In other words, when at least a part of the outer case is made of metal, if the core end face is placed in close proximity to the metal part of the inner peripheral surface of the outer case, radio waves are attenuated by the case, and the reception sensitivity is several. Decibel degradation. For this reason, the core end face must be arranged away from the outer case. In that case, in the case of an antenna placed in a small outer case such as a wristwatch, the length of the antenna is also shortened and the antenna characteristics are deteriorated. Resulting in.
On the other hand, as in the present invention, both ends of the core are arranged along the inner peripheral surface of the outer case, that is, the axial direction of both ends of the core is substantially parallel to the inner peripheral surface of the outer case adjacent to both ends of the core. If the both ends of the core are arranged close to the inner peripheral surface of the outer case, the end surfaces of the core can be separated from the outer case to some extent. Therefore, even when the outer case is made of metal, it is possible to suppress the deterioration of the reception sensitivity of the antenna, to secure the antenna length to some extent, to prevent the deterioration of the antenna characteristics, and to reduce the size of the watch. .
In addition, since the outer case can be made of metal, it is not necessary to make a double case or to form a notch in the case, so that the manufacturing cost can be reduced.
In addition, if a metal cover is used on at least a part, especially the exterior case surface, as in the case where a metal cover is attached to a plastic case, a metallic appearance can be obtained and a high-quality appearance design can be obtained. An electronic timepiece with a built-in antenna can be obtained.

Here, in the electronic timepiece with an antenna according to the present invention, at least a part of the circuit elements constituting the receiving means is arranged in a space formed between a line segment connecting both end faces of the core and the core. It is preferred that
For example, when the inner peripheral surface of the outer case is formed in a circumferential surface shape, the conventional antenna having a substantially planar core cannot be disposed along the inner peripheral surface of the outer case. Even if it is arranged as close as possible to the inner peripheral surface of the outer case, a dead space is generated between the antenna and the inner peripheral surface of the outer case. Since this dead space is too narrow to arrange circuit elements, it is generally a wasteful space that is not used after all. In addition, even if a part of the circuit element can be arranged in the dead space, the circuit element arranged in the dead space is arranged in a space formed on the opposite side of the dead space with the antenna interposed therebetween. It is necessary to form a conductor for electrically connecting to the antenna across the antenna, resulting in a problem of complicated wiring.
On the other hand, in the present invention, since both ends of the core are arranged along the inner peripheral surface of the outer case, it is easier to arrange the entire antenna along the inner peripheral surface of the outer case than in the past. Thus, the dead space can be narrowed and useless space can be reduced. Further, since the dead space can be reduced, the space for arranging the circuit elements can be widened, and the circuit elements can be arranged by making the maximum use of the space in the limited exterior case. Therefore, it is possible to reduce the size of the outer case that is required when arranging circuit elements similar to the conventional one. Furthermore, according to the present invention, it is not necessary to dare to arrange circuit elements in the dead space, and it is not necessary to form a conductive wire for electrically connecting the circuit elements across the antenna, so that wiring can be simplified. Further, in the present invention, at least a part of the circuit elements constituting the receiving means, for example, a tuning capacitor, a receiving IC, etc. are arranged in a space formed between the line connecting the both end faces of the core and the core. Therefore, the conducting wire for electrically connecting the antenna and the receiving means can be shortened. Therefore, the possibility that electromagnetic noise is mixed through the conducting wire is reduced, and radio waves can be received more accurately by the antenna and the receiving means.

Moreover, it is preferable that at least both ends of the coil are arranged along the inner peripheral surface of the outer case.
For example, when the coil is wound only on a part of the middle part of the core, that is, when the length of the coil winding part is shorter than half the total length of the core, both ends of the core are Even if it arrange | positions along a surface, the end surface of a coil may be opposingly arranged by a metal case. In this case, the magnetic field directly interlinking with the coil rather than from the end face of the core is hindered by the case, and the antenna characteristics are degraded accordingly. On the other hand, according to the present invention, since both ends of the coil are also arranged along the inner peripheral surface of the outer case, the magnetic field directly interlinking with the coil is less likely to be disturbed by the outer case, Accordingly, the antenna characteristics can be further improved.
Normally, if the coil is wound up to both ends of the core disposed along the inner peripheral surface of the case, the end of the coil can also be disposed along the inner peripheral surface of the case. In this case, the length of the coil can be maximized, and the antenna characteristics can be improved while suppressing the antenna arrangement space.
Here, when the coil is wound up to both ends of the core, it is usually difficult to completely wind the coil up to both ends of the core in the manufacturing process. Therefore, the coil is wound up to a position about several millimeters away from the end face of the core. However, if the coil can be wound up to both end faces of the core, the coil may be wound up to both end faces of the core.
Furthermore, the fact that both end portions of the coil are arranged along the inner peripheral surface of the case has the same meaning as the case where both end portions of the core are arranged along the inner peripheral surface of the case. When the peripheral surface is circumferential, it means that the axial direction of both ends of the coil and the tangential direction of the inner peripheral surface of the outer case adjacent to both ends of the coil are substantially parallel.

In addition, the inner peripheral surface of the outer case is formed in a circular shape, and the core has an arc shape whose plane shape is substantially concentric with the inner peripheral surface of the outer case, and along the inner peripheral surface of the outer case. Are preferably arranged.
With such a configuration, the entire length of the antenna consisting of the core and the coil can be arranged along the exterior case, and a large space for placing the movement etc. inside the case can be secured, so the space in the case is effective. Can be used. Therefore, the downsizing of the watch can be further promoted.

Also, in the electronic timepiece with built-in antenna of the present invention, the inner peripheral surface of the outer case is formed in a circumferential surface shape, and the core has both ends of an arc shape whose plane shape is substantially concentric with the inner peripheral surface of the outer case. And an intermediate portion having a substantially arcuate shape in which the coil is wound and connected between both ends, and the curvature of the intermediate portion is smaller than the curvature of each end. It may be a thing.
According to such a configuration, the intermediate part around which the coil is wound in the core has a small curvature and is closer to a linear shape, so that the coil can be easily wound. Therefore, the coil winding efficiency can be increased and the antenna can be easily manufactured.

Further, in the electronic timepiece with built-in antenna of the present invention, the inner peripheral surface of the outer case is formed in a circumferential surface shape, and the core has both ends of a circular arc shape whose plane shape is substantially concentric with the inner peripheral surface of the outer case. And a planar substantially arc-shaped intermediate portion around which the coils are wound and connected between both ends, and each contour line on the outer circumferential side and the inner circumferential side in the planar substantially arc-shaped shape of the intermediate portion is The center of curvature of the contour line on the outer peripheral side is formed at a position farther from the intermediate portion than the center of curvature of the contour line on the inner peripheral side. Also good.
According to the core having such a configuration, the outer peripheral side contour line and the inner peripheral side contour center of curvature coincide with each other, that is, the outer peripheral side and inner peripheral side contour lines are concentric. The curvature of the contour line on the outer peripheral side can be reduced as compared with the formed core having the intermediate portion. When the inner and outer contour lines are formed concentrically in the middle part of the core, the length of the inner contour line is shorter and the curvature is larger than the length of the outer contour line of the middle part. Therefore, even if the coil conductor wire can be wound without any gap on the inner circumference side contour line of the intermediate portion of the core, a gap is generated between the coil conductor wires on the outer circumference side contour, and the winding efficiency is reduced. To do.
On the other hand, in the core of the present invention, the contour on the outer peripheral side of the intermediate portion has a smaller curvature than the case where the inner and outer contours are formed concentrically. The difference in length can be reduced, and the length of each contour line can be made substantially equal depending on the setting of each curvature. Moreover, since the curvature of the contour line on the outer peripheral side is small, a shape close to a straight line can be obtained. Therefore, the coil conductor wire can be easily wound around the outer contour line without any gap, and when the coil conductor wire is wound without any gap on the inner contour line of the core intermediate portion, the coil conductor is also wound on the outer contour line. The gap between them can be made very small or eliminated, and the winding efficiency can be improved. Therefore, it is possible to improve radio wave reception sensitivity while suppressing the length of the antenna.

Furthermore, the said core may be comprised provided with the intermediate part which connects the both ends which have a linear planar shape, and each both ends, It may be characterized by the above-mentioned.
Here, the intermediate portion may be formed in an arc shape, may be formed in a polygonal shape composed of a plurality of linear portions, and is further formed in a linear shape connecting between both end portions. Also good.
If at least both ends are formed in a straight line, coil winding of that portion can be easily performed. Furthermore, if the intermediate part is also formed of one or a plurality of linear parts, the core cutting work and the coil winding work can be easily performed compared to the arc-shaped core, which is realized at low cost. be able to.

Moreover, it is preferable that the crossing angle of the line segment which connects each end surface of the both ends of the said coil and the center point of the outer peripheral surface of an exterior case is 60 degree | times or more.
The diameter of the outer peripheral surface of the exterior case in a wristwatch is usually about 30 mm. Therefore, when the coil is wound around a planar arc core or a planar polygonal core close to an arc shape, the length of the coil (antenna length) is the radius of the arc (about 15 mm) × the central angle (60 degrees). If it is, it can be calculated by 60/180 × π), which is about 15 to 16 mm. When receiving long wave standard radio waves (40 to 77.5 KHz), the antenna length may be about 15 mm. Therefore, if the crossing angle is 60 degrees or more, the antenna can be used as an antenna for receiving long wave standard radio waves. Can be configured. The center point of the outer peripheral surface of the outer case means the center point of the circumference if it is an arc-shaped inner peripheral surface, and the center point of the circumscribed circle if it is an inner surface of a regular polygon. .

Furthermore, the inner peripheral surface of the outer case is formed in a circumferential surface, and the inner peripheral surface of the outer case adjacent to the both ends of the core and the straight line along the center line direction in the width direction at both ends of the core. The angle of intersection with the tangent line is preferably in the range of 0 ± 30 degrees.
By setting this angle range, when the antenna is placed close to the inner peripheral surface of the outer case, the end surface of the core and the inner peripheral surface of the outer case can be separated by a distance of a predetermined dimension (several millimeters). A reduction in reception sensitivity can be prevented, and the space inside the outer case can be used effectively.
For example, in the case of a wristwatch, if the diameter of the inner peripheral surface of the outer case is about 30 mm and the width of the antenna core is about 3 mm, the center point in the width direction of the core when the crossing angle is 0 degree (the above-mentioned The distance from the inner circumferential surface to the inner circumferential surface is about 6.5 mm. When the intersection angle is +30 degrees, the distance is about 2.6 mm. Therefore, a predetermined space can be formed between the core end surface and the outer peripheral surface of the outer case, and a magnetic field of radio waves can be linked to the core end surface through the space portion, thereby preventing a decrease in reception sensitivity.
On the other hand, when the crossing angle is +30 degrees or more, for example, +45 degrees, the distance is about 2.0 mm, and the space is narrowed. Further, when the end face of the core becomes -30 degrees or more, the core end face is disposed away from the inner peripheral surface of the case on the center side of the case, and the space for placing the movement or the like is reduced, so that the timepiece of the watch This will hinder downsizing.
Therefore, if the angle is set within the angle range, the space inside the case can be used effectively, and a decrease in reception sensitivity can be prevented.
In addition, +1 degree to +30 degree means that the end surface of the core is inclined in a direction facing the inner peripheral surface of the outer case from a state where the tangent line and the straight line are parallel (intersection angle 0 degree). 1 degree to -30 degrees means that the end face of the core is inclined in a direction facing the central portion side of the exterior case.

Moreover, it is preferable that the said core is comprised with the magnetic body which consists of laminated amorphous foil. At this time, the stacking direction of the amorphous foils may be the thickness direction of the timepiece, or the plane direction of the timepiece (direction orthogonal to the thickness direction).
As the laminated amorphous foil, various amorphous metal thin plates such as cobalt-based amorphous metal and iron-based amorphous metal magnetic material can be used. If a laminated amorphous foil is used as such a magnetic core, the cross-sectional area in the direction in which magnetic flux flows can be reduced, eddy currents caused by changes in magnetic flux can be suppressed, and iron loss can be reduced. Then, the magnetic field generated by the eddy current can be suppressed, and as a result, the receiving sensitivity of the antenna can be improved.
Furthermore, when the stacking direction of the amorphous foil is set to the thickness direction of the watch, that is, the direction connecting the back cover of the watch and the surface glass, the thickness dimension of the antenna can be reduced. That is, the thickness dimension of the amorphous foil is usually about 0.01 mm to 0.05 mm, and about 10 to 30 amorphous foils are laminated to constitute an antenna. Therefore, the thickness dimension of the core in the amorphous lamination direction is about 1.5 mm at the maximum, and can be very thin as compared with a conventional ferrite core or the like. For this reason, the thickness of the timepiece itself can be reduced, and a thin and high-quality timepiece can be provided.
Further, when the lamination direction of the amorphous foil is set to the plane direction of the watch, that is, the direction orthogonal to the direction connecting the watch case back and the surface glass, the dimension of the antenna in the plane direction can be reduced. For this reason, the plane space which an antenna occupies inside a timepiece can be made small, and arrangement space, such as a movement, can be enlarged. In addition, when the antenna is formed in a planar arc shape along the inner frame, that is, the inner peripheral surface of the outer case, the amorphous foil cut into a rectangular shape may be bent and stacked, and can be manufactured easily and efficiently.

Furthermore, the electronic timepiece with built-in antenna of the present invention preferably includes a battery for supplying power, and the antenna is disposed on the opposite side of the battery across the center of the inner peripheral surface of the outer case.
A battery is usually configured with a stainless steel case, and when placed near the antenna, the antenna characteristics are affected. Therefore, if the antenna and the battery are arranged with the center of the outer case interposed therebetween, the antenna and the battery can be arranged apart from each other, and deterioration of the antenna characteristics due to the battery can be prevented.

  As described above, according to the electronic timepiece with built-in antenna of the present invention, it is possible to improve the appearance design of the outer case, reduce the manufacturing cost, and realize the downsizing of the timepiece.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same constituent elements are denoted by the same reference numerals, and the description thereof is omitted or simplified.
[First Embodiment]
FIG. 1 is a block diagram showing a configuration of a radio-controlled timepiece 1 as an antenna built-in type electronic timepiece according to the first embodiment of the present invention.
A radio wave correction timepiece 1 of the present invention has a configuration similar to that of a general radio wave correction timepiece, and includes a receiving means 2 as communication means for receiving radio waves (external wireless information) including time information, and a drive control means. Drive control circuit unit 3, drive unit 4 for driving the hands, counter unit 6 for counting time, power supply unit 7 for supplying power, and external input device 8 such as a crown. ing.

The receiving means 2 includes an antenna 21 that receives radio waves, a tuning circuit portion 22 that is configured by a capacitor and tunes to radio waves received by the antenna 21, a receiving circuit 23 that processes information received by the antenna 21, and a receiving circuit 23 And a time data storage circuit unit 24 for storing the time data processed in (1).
As shown in FIG. 2, the antenna 21 is configured by winding a coil 212 around a magnetic core 211, and is insulated by cationic electrodeposition coating having excellent corrosion resistance, if necessary.

The magnetic core 211 is formed by, for example, punching a cobalt-based amorphous foil (for example, 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 a plane arc-shaped amorphous foil in the thickness direction of the watch. The magnetic core is not limited to the laminated amorphous foil, and ferrite may be used. In this case, the magnetic core may be formed by a mold or the like and heat-treated.
Here, since each amorphous foil of the magnetic core 211 has a thickness dimension of about 0.01 mm to 0.05 mm, for example, when 30 sheets are stacked, the thickness dimension of the magnetic core 211 in the stacking direction is 0.00. It is about 3 to 1.5 mm. Since the amorphous material has better magnetic characteristics than ferrite, a smaller and thinner antenna 21 can be realized. Since antenna characteristics are affected by the volume of the core, the antenna area must be increased or the antenna length (core length) must be increased in order to maintain the antenna characteristics by making the antenna thinner. There is. Therefore, in this embodiment, the width dimension of the magnetic core 211 is, for example, about 0.5 to 3.0 mm, and the length is about 15 to 30 mm. If the thickness of the amorphous metal plate is greater than 0.05 mm, it is difficult to quickly cool the central portion of the plate pressure, so that the metal is crystallized without being amorphized. That is, in order to produce an amorphous metal, it is necessary to perform a rapid cooling operation before the metal is crystallized. For this purpose, the thickness of the metal must be reduced. In addition, when the thickness of the amorphous metal plate is less than 0.01 mm, the strength of the amorphous metal plate is weakened and easily deformed during assembly work, etc., so that it is very difficult to position the parts and handle the parts. .

The coil 212 needs an inductance value of about 10 mH when receiving a long-wave standard radio wave (40 to 77.5 kHz). For this reason, in this embodiment, the coil 212 is formed by winding a uremet wire having a diameter of about 0.1 μm for several hundred turns. In the present embodiment, the coil 212 is not wound up to the end surface 211B of the core 211 to facilitate the winding operation of the coil 212 and to prevent the end portion from being unwound. Is wound to a position several millimeters apart. Accordingly, the end portion 211A of the core 211 has a portion where the coil 212 is not wound.
Further, the winding method of the coil 212 is not particularly limited, and random winding may be used, but aligned winding is particularly preferable. If the aligned winding is employed, there is no useless space between the coil wires, and the coil volume for obtaining the same inductance value can be reduced. In this embodiment, since the core 211 has a planar arc shape, the antenna 21 is manufactured as follows. First, a coil of a self-bonding electric wire is wound around a bobbin, and then the coil is hardened by dipping in heat or a solution. After the coil is solidified, the bobbin is pulled out, and the magnetic core 211 is inserted into a through-hole portion formed by pulling out the bobbin. The antenna may be configured by inserting a core into a bobbin wound with a coil. In this case, the size is increased by the presence of the bobbin, but the antenna can be easily manufactured.

As shown in FIG. 3, 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.

As shown in FIG. 3, the receiving circuit 23 amplifies the long wave standard radio signal received by the antenna 21, and a bandpass filter 232 that extracts only a desired frequency component from the amplified long wave standard radio signal. 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 demodulation And a decoding circuit 235 for decoding and outputting the long wave standard radio wave signal.
The time data received and signal processed by the receiving circuit 23 is output to and stored in the time data storage circuit unit 24 as shown in FIG.
The reception circuit 23 starts reception of 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. 1, the drive control circuit unit 3 receives the pulse signal from the pulse synthesis circuit 31. 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 drive control circuit unit 3 outputs a second drive pulse signal PS1 that is output once per second to drive the second hand, and an hour / minute drive pulse signal PS2 that is output once per minute to drive the hour / minute hand. 41, output to the hour / minute driving circuit 42 to control the driving of the hands. That is, each drive circuit 41, 42 drives a second motor 411, which is a stepping motor driven by a pulse signal from each circuit 41, 42, and an hour / minute motor 421, thereby being connected to each motor 411, 421. The second hand, the minute hand and the hour hand are driven. Each pointer, motors 411 and 421, and drive circuits 41 and 42 constitute time display means for displaying the time. In addition, as a time display means, you may drive an hour hand, a minute hand, and a second hand with one motor.

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. Both the second position counter 611 and the second time counter 612 are counters that loop in 60 seconds when a signal of 60 counts, that is, 1 Hz 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. doing.
The hour / minute time counter 622 normally counts a 1 Hz pulse (clock pulse) output from the drive control circuit unit 3 (more precisely, 1 count is counted 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.

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. As the high capacity secondary power source 72, a secondary battery such as a lithium ion battery can be used. As the power supply means 7, a primary battery such as a silver battery may be used.
The external input device 8 as an external input means includes a crown and is used for performing a receiving operation, time adjustment, and the like.

Next, a specific structure of the radio-controlled timepiece 1 will be described.
As shown in FIGS. 4 and 5, the radio-controlled timepiece 1 includes a casing (cylinder) 91 formed in an approximately ring shape, a cover glass 92 attached to the front surface side of the casing 91, and a back surface side of the casing 91. And a back cover 93 that is detachably attached. The casing 91 is made of a metal material such as stainless steel, brass, or titanium. Therefore, the casing 91 constitutes a metal exterior case (watch case) 9 in the present embodiment. Each component including the antenna 21 is incorporated in the outer case 9.
That is, the circuit board 80 to which the receiving IC 81, the CPU 82, the reference vibrator 311 and the like constituting the receiving circuit 23, the drive control circuit unit 3 and the counter unit 6 are attached, and the motor and the train wheel constituting the driving unit 4 are incorporated. The timepiece (movement), the high-capacity secondary power source (secondary battery) 72 constituting the power supply means 7, and the dial 95 and the base plate 96 provided on the surface side of the timepiece are incorporated. ing.
The antenna 21 is fixed to the ground plane 96 using a thermoplastic resin (hot melt), an ultraviolet curable epoxy, or the like. Moreover, in order to give the function as a buffer material of the antenna 21, it may be fixed using an elastic sealing material.

Here, the antenna 21 and the receiving IC 81 are connected by two wires. That is, the antenna 21 and the receiving IC 81 are electrically connected by taking out the coil 212 from the end of the antenna and soldering it to the circuit board 80. 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.
Further, the dial plate 95 can be made of a metal such as brass (brass, Bs), white (white silver, NS), etc., but a non-conductive member (electrical insulator) such as plastic or ceramic. In other words, it is preferably made of a material that allows easy transmission of standard radio waves.
The back cover 93 may be made of a metal material similar to that of the casing 91, but is preferably made of a non-conductive member (electrical insulator) such as plastic or glass, that is, a material that can easily transmit radio waves.

  At two opposing portions of the casing 91, usually at the 12 o'clock direction and 6 o'clock direction on the dial plate 95, connecting protrusions (cans) 94 for connecting the watch band are respectively provided. The watch band attached to the casing 91 is configured by connecting a plurality of piece members so as to be rotatable with pins (spring bars or the like). The piece member at the end is also rotatably connected to the casing 91 with a pin.

The antenna 21 is disposed along the circumferential inner surface 91 </ b> A of the casing 91, that is, the outer case 9. That is, as shown in FIG. 4, the planar shape of the magnetic core 211 of the antenna 21 is formed in an arc shape that is substantially concentric with the inner peripheral surface 91 </ b> A, and the coil 212 is wound around the magnetic core 211 to form a substantially circular plane. It is configured in an arc.
Here, the crossing angle θ1 of the line segment connecting the end faces of both end portions 212A of the coil 212 and the center point O of the inner peripheral face 91A is approximately 115 degrees, and is set to 60 degrees or more.
The antenna 21 is arranged in the 12 o'clock direction with respect to the center point O of the outer case 9. On the other hand, the high-capacity secondary power source (secondary battery) 72 is arranged at about 7 o'clock with respect to the center point O. Therefore, the antenna 21 and the secondary battery 72 are disposed on the opposite sides with respect to the center point O, and are disposed relatively far apart. Further, the reference vibrator 311 is also arranged farther from the antenna 21 than the receiving IC 81, the CPU 82, and the like. A spacer made of a plastic disk (not shown) is provided between the antenna 21 and the movement as a cushioning material.

Since the core 211 is formed in a planar arc shape, it is adjacent to the axial direction of both end portions 211A of the core 211, that is, the straight line L2 along the center line direction in the width direction at both end portions 211A, and both end portions 211A of the core 211. The crossing angle of the inner peripheral surface 91A with the tangent line L1 is approximately 0 degrees.
That is, of the tangent lines in contact with the inner peripheral surface 91A of the casing 91, the radius passing through the center point P in the width direction of the core 211 on the end surface 211B of both end portions 211A of the core 211 and the tangent line L1 at the intersection Q with the inner peripheral surface 91A If the both ends 211B of the core 211 are axial directions of the two ends 211A, that is, the extending direction of both ends 211, and the both ends 211B of the core 211 are surfaces along the radius, the straight line L2 along the direction orthogonal to the end surface 211B is They are arranged in parallel. That is, the intersection angle between the lines L1 and L2 is approximately 0 degrees, and the intersection angle is within a range of 0 degrees ± 30 degrees.
Similarly, since the coil 212 is also configured in a planar arc shape, the straight line along the axial direction of the coil 212 at both ends 212A of the coil 212 is tangent to the inner peripheral surface 91A adjacent to both ends 212A of the coil 212. Are arranged substantially in parallel.

When the antenna 21 receives a radio wave such as a long wave standard radio wave, as shown in FIG. 6, the magnetic field component, which is a part of the radio wave, causes the core 211 of the antenna 21 to move from one end 211A to the other end. Passes to part 211A. Then, an alternating current is induced in the coil 212 wound around the core 211, and accordingly, an alternating voltage is generated at both ends of the coil 212. Then, this AC voltage flows through the reception circuit 23 as an analog reception signal.
The analog reception signal is subjected to processing such as amplification, demodulation, and decoding by the reception circuit 23 to obtain digital time data, which is stored in the time data storage circuit unit 24.
That is, the antenna 21 has directivity that reacts to a magnetic field in an extension line direction (an axial direction of the core 211 and the coil 212) connecting the end portions 211A of the core 211. Therefore, if the metallic casing 91 is disposed close to the core 211 or the coil 212 in the axial direction, the magnetic field interlinking the coil 212 is hindered, so that the antenna characteristics (reception sensitivity) of the antenna 21 are reduced. To do. On the other hand, in the present embodiment, as described above, the core 211 and the coil 212 are formed in a planar arc shape, and the end portions 211A and 212A are arranged along the inner peripheral surface 91A. As shown, the distance W1 to the metal casing 91 arranged in the axial direction can be made relatively large, and the radio wave reception sensitivity of the antenna 21 can be improved. The dimension W1 is set depending on the diameter of the inner peripheral surface 91A and the like. For example, if the inner peripheral surface 91A has a diameter of about 30 mm and the antenna core has a width of about 3 mm, the intersection angle is set to 0 degree. The distance W1 from the center point P in the width direction on the end surface 211B of the core 211 (a position about 1.5 mm away from the inner peripheral surface) to the inner peripheral surface 91A is about 6.5 mm.
Note that the distance from the end 211A of the core 211 to the secondary battery 72 and the reference vibrator 311 is made larger than the distance W1, and like the casing 91, the secondary battery 72 and the reference vibrator 311 are subjected to an interlinkage magnetic field. It is supposed not to affect. That is, since the secondary battery 72 includes a metal case such as stainless steel, the interlinkage magnetic field is affected when the secondary battery 72 is disposed close to the core 211 like the casing 91. On the other hand, as the reference vibrator 311, a 32.768 kHz crystal vibrator is used, and since this vibration frequency is close to the long wave reception frequency (40 kHz), the reference vibrator 311 is disposed close to the antenna 21. There is a possibility that a signal is mixed in the antenna 21 as noise. Accordingly, the secondary battery 72 and the reference vibrator 311 are arranged at the same distance as the casing 91 with respect to the core 211.

Next, a specific configuration of the drive circuits 41 and 42 of the motors 411 and 421 will be described. Since the configuration of each of the drive circuits 41 and 42 is basically the same, the drive circuit 41 of the second motor 411 will be described as an example.
The motor 411 is a stepping motor driven by a pulse signal. Specifically, as shown in FIG. 7, a drive coil 412 that generates a magnetic force by a drive pulse supplied from the second drive circuit 41, a stator 413 excited by the drive coil 412, and excitation inside the stator 413 And a rotor 414 rotated by a magnetic field generated.
The rotation of the rotor 414 of the motor 411 is transmitted to the second hand by a wheel train composed of a fifth wheel 415 and a fourth wheel 416 engaged with the rotor 414 via the kana. Although not shown, the rotation of the rotor of the motor 421 is transmitted to the minute hand and the hour hand by a train wheel composed of the third wheel, the second wheel, the minute wheel, and the hour wheel.

The second drive circuit 41 includes a bridge circuit including a p-channel MOS 43A and an n-channel MOS 44A connected in series, and a p-channel MOS 43B and an n-channel MOS 4B connected in series.
The second drive circuit 41 includes rotation detection resistors 45A and 45B connected in parallel to the p-channel MOSs 43A and 43B, and sampling p-channel MOSs 46A and 46B for supplying chopper pulses to the resistors 45A and 45B, respectively. 46B. Therefore, by applying a control pulse having a predetermined polarity and pulse width from the drive control circuit unit 3 to each gate electrode of the MOSs 43A, 43B, 44A, 44B, 46A, and 46B at each timing, the polarity is applied to the drive coil 412. Drive pulses different from each other, or a detection pulse for exciting an induced voltage for rotation detection or magnetic field detection of the rotor 414 can be supplied.

The operation of the radio-controlled timepiece 1 having such a configuration will be described.
First, normal time display will be described. Normally, the drive control circuit unit 3 uses the pulse signal (reference signal) input from the pulse synthesizing circuit 31 to send a 1 Hz pulse signal to count up the counter value of the second time counter 612. When the second time counter 612 counts up and differs from the counter value of the second position counter 611, the coincidence detection circuit 613 detects the mismatch and outputs a mismatch signal to the drive control circuit unit 3. The drive control circuit unit 3 outputs the second drive pulse signal PS1 based on the mismatch signal. The second position counter 611 is counted up by the output of the second drive pulse signal PS1, and the second motor 411 is driven by appropriately turning on and off the MOSs 43A, 43B, 44A, 44B of the second drive circuit 41, The second hand is driven. The above processing is performed by the coincidence detection circuit 613 until the values of the counters 611 and 612 coincide. Therefore, at the time of normal hand movement, every time 1 Hz is input to the second time counter 612 and the counter value is incremented by “1”, one second drive pulse signal PS1 is output, and the second hand is stepped every one second. The
Similarly, the hour / minute drive pulse signal PS2 is output from the drive control circuit unit 3 so that the count value of the hour / minute position counter 621 matches the count value counted by the hour / minute time counter 622. In response to the drive pulse signal PS2, the hour / minute drive circuit 42 outputs a pulse signal to the hour / minute motor 421 to drive the hour and minute hands.

Next, the operation when receiving time information will be described.
When the set reception start time is reached, the drive control circuit unit 3 outputs a predetermined pulse signal to the second drive circuit 41 and the hour / minute drive circuit 42, turns on the MOSs 43A and 43B, and sets both ends of the drive coil 412 to the potential. Connected to VDD to short circuit. In the present embodiment, the potential VDD (high voltage side) is taken as the reference potential (GND), and VSS (low voltage side) is generated as the power supply voltage.

The drive control circuit unit 3 drives the receiving circuit 23 to start receiving time information after stopping the motors 411 and 421 by short-circuiting the drive coils 412 of the motors 411 and 421. It is also possible to forcibly start (forced reception) by an operation of starting the reception operation by the external input device 8, but in this case also, when the reception operation is instructed by the external input device 8, the drive control circuit unit 3 First, the drive coil 412 is short-circuited to fix the voltage at a predetermined potential (for example, VDD), and then the reception circuit 23 is driven to start receiving time information.
When the receiving circuit 23 is activated, radio waves (time information) received via the antenna 21 are processed by the receiving circuit 23 and then stored in the storage circuit unit 24. At this time, verification of whether the received time data is correct is also performed. Specifically, since the time information of the long wave standard radio wave is data for every minute, it is determined based on whether or not the received time data are data with different one minute intervals.
When the received time information is determined to be correct data, the time data is output to the second time counter 612 and the hour / minute time counter 622 according to the instruction of the drive control circuit unit 3, and the second time counter 612 and the hour / minute time counter 622 are output. The count value is corrected. At this time, the short state of the drive coil 412, that is, the stopped state of the motors 411 and 421 is also released.
When the count values of the time counters 612 and 622 are corrected and become different from the position counters 611 and 621, the mismatch detection circuits 613 and 623 receive the mismatch signal until the count values match. The drive control circuit unit 3 outputs the drive pulse signals PS1 and PS2 to drive the hands. Since the driving of the pointer is continued by fast-forwarding until each counter value matches, the pointer position is automatically corrected according to the reception time, and the time is adjusted.

According to the above-described embodiment, the following effects can be obtained.
(1) Since both end portions 211A of the core 211 of the antenna 21 are arranged along the inner peripheral surface 91A of the exterior case 9, the distance between the inner peripheral surface 91A in the axial direction of the core 211 and the end surface 211B of the core 211, That is, the interval W1 between the end surface 211B of the core 211 and the inner peripheral surface 91A at a position facing the end surface 211B can be made relatively large. For this reason, the magnetic field of the standard radio wave interlinking the coil 212 through the core 211 is less likely to be hindered by the outer case 9, and even when the metal outer case 9 is used, the deterioration of the antenna characteristics can be suppressed. it can.
Therefore, since external wireless information can be received even when the metal case 9 is used, a high-quality appearance design can be obtained compared to the case where the case is made of plastic or the like. Fewer radio wave correction watches 1 can be provided. In addition, since it is not necessary to form a notch in the outer case 9 or to make the outer case a double case of plastic and metal, the manufacturing cost can be reduced. Furthermore, since the antenna 21 can be disposed close to the inner peripheral surface 91A, the length of the antenna 21 can be secured to some extent, the deterioration of the antenna characteristics can be prevented, and the timepiece 1 can be miniaturized.

  (2) Since the coil 212 is wound up to the end portion 211 </ b> A of the core 211, both end portions 212 </ b> A of the coil 212 can be arranged along the inner peripheral surface 91 </ b> A of the case 9. For this reason, the magnetic field of the standard radio wave that enters from the end surface portion of the coil 212 and interlinks in the coil 212 is also less likely to be hindered by the case 9, and when the metal outer case 9 is used, the antenna characteristics are deteriorated. It can be further suppressed. In addition, the number of turns of the coil 212 can be increased as compared with the case where the coil is wound only on a part of the central portion of the core 211, and the sensitivity of the antenna 21 can be improved accordingly.

(3) Since the antenna 21 is arranged away from the high-capacity secondary power source (secondary battery) 72, the battery 72 having a metal case can be reduced from affecting the antenna characteristics, and the antenna characteristics can be further reduced. It can be further suppressed.
In addition, since the antenna 21 is arranged away from the reference vibrator 311, it is possible to prevent the signal of the reference vibrator 311 from being mixed in the received signal as noise, and the deterioration of the antenna characteristics can be further suppressed.

(4) Since the antenna 21 is formed in a planar arc shape, the antenna 21 can be disposed along the case inner peripheral surface 91A over the entire length thereof. For this reason, the clearance gap between 91 A of internal peripheral surfaces and the antenna 21 can be made very small, the dead space inside case 9 can be eliminated, and the internal space of case 9 can be utilized effectively. For this reason, the exterior case 9 can be miniaturized, and for example, the antenna 21 can be incorporated even in a female wristwatch that is smaller than a male wristwatch.
In addition, the layout of each IC, battery, etc. disposed inside the case 9 is less restricted, and the antenna 21 having a relatively large or large number of turns can be used, and the antenna sensitivity can be improved.

  (5) Since the coil 212 of the antenna 21 is configured so that its central angle is 60 degrees or more, the length of the coil 212 (antenna length) can be about 15 mm or more, and a standard radio wave is received. can do. In particular, in the present embodiment, the central angle is increased to about 115 degrees, so that the antenna length can be increased correspondingly, and the antenna characteristics can be improved.

  (6) When the exterior case 9 is made of a material other than a metal material such as plastic, in order to ensure the required strength, the case 9 needs to be devised to make it thicker or provided with reinforcing ribs. Since the case 9 made of metal is used, when the thickness is the same as that made of plastic, the case 9 can be made stronger, or the thickness of the case 9 necessary to ensure the same strength. The dimensions can be reduced.

  (7) Since the lamination direction of the amorphous foil is the thickness direction of the timepiece 1, that is, the direction connecting the back cover 93 and the surface glass 92 of the timepiece, the thickness dimension of the antenna 21 is set when a ferrite core or the like is used. It can be made very small in comparison. For this reason, the thickness dimension of the timepiece 1 itself can be reduced, and a thin and high-class timepiece 1 can be provided.

(8) The drive control circuit unit 3 fixes the drive coil 412 to the potential VDD when receiving radio waves, so that the antenna characteristics are not adversely affected as in the case where the drive coil 412 is open. The antenna characteristics can be improved.
(9) Since the antenna 21 has the magnetic core 211 inserted, the directivity of the antenna 21 can be made sharper and the antenna characteristics can be improved.
(10) Since amorphous has a coercive force of about 0.32 A / m, which is smaller than that of ferrite, even when a metal is arranged around it, it is not easily affected by the magnetic influence from the metal. . In this embodiment, since the thing made from amorphous foil is used as the magnetic body core 211, even if the exterior case 9 is made from metal, the magnetic body core 211 is hardly affected by the exterior case 9 magnetically. Therefore, since the magnetic core 211, and thus the antenna 21, can be disposed closer to the inner peripheral surface 91A of the exterior case 9, the dead space between the inner peripheral surface 91A and the antenna 21 can be reduced. For this reason, the space in the exterior case 9 can be used effectively without waste, and the exterior case 9 can be downsized.
When the exterior case 9 is made of metal, an intermediate frame made of an insulating material is provided between the inner peripheral surface 91 </ b> A of the exterior case 9 and the antenna 21 in order to insulate the exterior case 9 from the antenna 21. It is common. In the present embodiment, the magnetic core 211 is made of an amorphous material, and is not easily affected by the magnetic force from the outer case 9, and can be disposed close to the inner peripheral surface 91A as described above, so that the inner frame can be made thin. Therefore, the outer case 9 can be downsized even when the middle frame is provided.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the second embodiment, since only the planar shape of the antenna is different from that of the first embodiment, only that portion will be described. In the following embodiments, the same or similar components as those of the above-described embodiments are denoted by the same reference numerals, and description thereof is omitted or simplified.
As shown in FIG. 8, the magnetic core 511 of the antenna 51 of the second embodiment includes end portions 511A and intermediate portions 511B that connect the end portions 511A. Here, each of the end portions 511A and the intermediate portion 511B is not formed in a planar arc shape but is formed in a straight line shape.
Here, as in the first embodiment, the crossing angle θ2 of the line segment connecting both end faces of the coil 512 and the center point O of the inner peripheral surface 91A is about 105 degrees, and is set to 60 degrees or more. Further, the crossing angle θ3 between the axial straight line L2 of the end portion 511A of the core 511 and the tangent line L2 of the inner peripheral surface 91A adjacent to the end portion 511A is about 15 degrees, that is, in the range of 0 degree ± 30 degrees. The end of the coil 512 is disposed along the inner peripheral surface 91A.

In the second embodiment, the same operational effects as those of the first embodiment can be obtained.
Further, (11) since the antenna 51 is configured in a polygonal shape instead of a planar arc shape, the arc-shaped core 211 is used for the work of cutting the core 511 from the amorphous plate and the winding work of the coil 512. This can be performed more easily than the case, and the manufacturing workability of the antenna 51 can be improved.

The present invention is not limited to the above embodiments.
That is, the present invention has been illustrated and described primarily with respect to particular embodiments, but without departing from the spirit and scope of the present invention relative to the embodiments described above. Various modifications may be made by those skilled in the art in terms of shape, material, quantity, and other detailed configurations.
For example, as a configuration of the antenna, as shown in FIGS. 9A and 9B, an intermediate portion 521B between the end portions 521A of the core 521 is composed of a plurality of straight portions, and a coil 522 is attached to the core 521. A wound planar polygonal antenna 52 may be used. Although the core 521 may be configured with the same width dimension over the entire length, in FIG. 9, the width dimension W3 of both ends 521A where the coil 522 is not wound is the width of the intermediate part 521B where the coil 522 is wound. It is formed larger than the dimension W4. Thus, if the width dimension of the core both ends 521A is increased, the volume of the core 521 can be increased without changing the thickness dimension of the portion around which the coil 522 is wound, and without increasing the antenna 52, Antenna characteristics can be improved.
Further, the antenna 52 can easily cut out the core and wind the coil, as well as the antenna 51 of the second embodiment, and is closer to the arc shape than the antenna 51. The dead space between the inner peripheral surface 91A of the case can be made smaller than that of the antenna 51, and the space efficiency can be improved.
In this case, it is preferable to wind an insulating tape having a thickness of about 20 to 30 μm around a portion where the coil 522 of the core 521 is wound. If this insulating tape is wound, the coil 522 and the core 521 can be reliably insulated, and when the core 521 is formed in a rectangular cross section as shown in FIG. Can be prevented from being cut at the corner edge of the core 521. In addition, if a substantially U-shaped winding frame 523 made of polyester or the like is set at the step portion of the core 521, that is, the end portion of the portion around which the coil 522 is wound, the coil 522 can be easily wound, It is possible to prevent the end portion from being wound.
Furthermore, an antenna in which an intermediate part of the core is formed in an arc shape and both end parts are configured in a straight line may be used.

Further, the antenna having the configuration shown in FIG. 10 may be used. The core 531 of the antenna 53 has a substantially circular arc shape in plan, but the curvature of both end portions 531A and the curvature of the intermediate portion 531B are different. The radius of curvature of the contour line on the outer peripheral side of the end portion 531A is R1, and the radius of curvature on the outer peripheral side of the intermediate portion 531B is R2, and R1 <R2. Therefore, the curvature of the intermediate part 531B is smaller than the curvatures of both end parts 531A, and the intermediate part 531B is close to a linear shape. According to such an antenna 53, since the intermediate portion 531B is close to a linear shape, it is easy to wind the coil 532, the winding efficiency can be improved, and the antenna 53 can be easily manufactured. It should be noted that both end portions 531A of the core 531 can be disposed along the inner peripheral surface 533 by setting the radius of curvature of the circumferential inner peripheral surface 91A of the outer case 9 to a value substantially equal to R1. Further, in the antenna 53, the intermediate portion 531B of the core 531 may be formed in a linear shape.
Further, as shown in FIG. 10, both end portions 531 </ b> A of the core 531 are increased in width and length and have a large area. For this reason, the radio wave is easily taken into the antenna 53 through the both end portions 531A. Therefore, the radio wave reception sensitivity of the antenna 53 can be improved. The length dimension of each end portion 531A is, for example, about 1/6 to 1/12 times the circumferential length of the inner peripheral surface 91A of the exterior case 9, or 1/1/2 of the length of the intermediate portion 531B. About 2 to 1 times can be selected as appropriate.

In the first embodiment, the magnetic core 211 having a flat circular arc shape is used, and the center of curvature of the contour line on the outer peripheral side and the contour line on the inner peripheral side in the flat circular arc shape of the intermediate portion around which the coil 212 is wound. And the center of curvature of (1) in FIG. In contrast, in the present invention, as shown in FIG. 11, the center of curvature 0o of the contour line Co on the outer peripheral side (upper side in FIG. 11) in the planar shape of the intermediate portion 541A in the core 541 and the inner peripheral side ( The antenna 54 having a configuration in which the curvature center 0i of the contour line Ci on the lower side in FIG. 11 is not coincident may be used. In FIG. 11, the contour line Co is an arc having a curvature radius Ro, the contour line Ci is an arc having a curvature radius Ri, and the curvature centers 0o and 0i are the centers of the respective arcs. Here, 0o and 0i do not match, and 0o is formed at a position farther from the intermediate portion 541A than 0i. Therefore, the curvature of the contour line Co on the outer peripheral side is smaller than the curvature of the contour line on the outer peripheral side in the core 211 having the same size as the core 541, and the contour line Co is close to a linear shape.
In FIG. 4, when the coil 212 is wound around the core 211, the length of the portion of the coil 212 on which the coil 212 is wound is set on the outer periphery of the core 211, and the coil 212 is wound on the inner periphery. It tends to be larger than the length of the portion to be cut, and a gap is likely to be generated between the conductors of the coil 212 on the outer peripheral contour line. That is, even if the conductor wire of the coil 212 can be wound around the contour line on the inner peripheral side of the intermediate portion of the core 211 without a gap, a gap is generated between the conductor wires of the coil 212 on the contour line on the outer peripheral side. Winding efficiency will deteriorate. However, in FIG. 11, the contour line Co on the outer peripheral side is closer to a linear shape than in the case of FIG. 4, so that the conductor of the coil 542 can be easily wound around the contour line Co without gaps. The length Lo of the portion around which the conducting wire is wound and the length Li of the portion around which the conducting wire of the coil 542 is wound on the contour line Ci can be made substantially equal. As described above, when the conductor of the coil 542 is wound around the contour line Ci on the inner peripheral side without any gap, the gap generated between the conductors of the coil 542 on the contour Co can be reduced or eliminated, and the winding efficiency is improved. Can be made. Therefore, it is possible to improve antenna characteristics while suppressing the length of the antenna 54.

In the embodiment, as shown in FIG. 3, the capacitance of a circuit including the antenna 21 and the tuning circuit unit 22 (hereinafter referred to as an antenna circuit) is switched by switching the switch 22C, and the received radio frequency is changed. Although switching has been performed, as shown in FIG. 12, the received radio wave frequency is switched not only by switching the capacitance of the antenna circuit but also by switching both the capacitance and the inductance (antenna inductance). It may be.
In FIG. 12, the antenna 21 is configured by connecting a first antenna portion 21A having an inductance La and a second antenna portion 21B having an inductance Lb in series. Inductance is switched. The switch 223 opens and closes the circuit based on the frequency switching control signal S1 output from the drive control circuit unit 3. When the switch 223 is on, the inductance of the antenna circuit is La, and when it is off Is La + Lb. In addition, two capacitors 221 (capacitance C1) and 222 (capacitance C2) are connected in parallel to the antenna 21, and the total capacitance of the antenna circuit is switched by switching the switch 224. The switch 224 opens and closes the circuit based on the frequency switching control signal S2 output from the drive control circuit unit 3. When the switch 224 is on, the capacitance of the antenna circuit is C1 + C2, and the switch 224 is off. Is C1. In FIG. 12, T1, T2, and T3 are terminals.
As described above, by switching the inductance and capacitance of the antenna circuit using the switches 223 and 224, the impedance of the antenna circuit can be changed and the frequency of the radio wave received by the antenna 21 can be switched. Thus, for example, a 40 kHz long wave standard radio wave output from a standard radio wave output station in Japan's Otakado and Mt. (East Japan), a standard radio wave output station in Japan, Mt. Hagane (West Japan), or a standard in the United States, etc. Switch and receive the long-wave standard radio wave of 3 types of frequency, 60kHz long-wave standard radio wave output from the radio wave output station, and 77.5kHz long-wave standard radio wave output from the standard radio wave output station in Germany etc. be able to.
Specifically, as shown in FIG. 13, the switching reception of the long wave standard radio wave is performed by switching on / off of the switches 223 and 224 for each reception radio wave frequency.
When the switch 223 is off and the switch 224 is on, the antenna 21 receives a 40 kHz long wave standard radio wave. The tuning frequency (resonance frequency) f _40k (= 40 kHz) of the antenna circuit at this time is expressed by the following equation (1).

When the switches 223 and 224 are on, the antenna 21 receives a long-wave standard radio wave of 60 kHz. The tuning frequency f _60k (= 60 kHz) at this time is expressed by the following formula 2.

When the switch 223 is on and the switch 224 is off, the antenna 21 receives a long-wave standard radio wave of 77.5 kHz. The tuning frequency f _77.5k (= 77.5 kHz) at this time is expressed by the following formula 3.

Here, La, Lb, C1, and each value of C2 _{is, f 40k = 40kHz, f 60k} = 60kHz, so as to satisfy f 77.5k = 77.5kHz, each equation, is set appropriately beforehand It shall be.

According to such a configuration, the amount of change in the impedance of the antenna circuit accompanying the switching of the reception radio frequency can be reduced, impedance matching with the receiving IC can be appropriately taken, and the sensitivity of the antenna can be improved. This will be described with reference to FIG.
FIG. 14 is a graph in which the horizontal axis represents the received radio frequency in the antenna circuit, and the vertical axis represents the impedance of the antenna circuit. The numerical value on the vertical axis is expressed as a ratio with respect to the impedance value of the point corresponding to the received radio frequency of 40 kHz among the three points in FIG.

  The solid line in FIG. 14 represents the relationship between the received radio frequency and the impedance in the antenna circuit having a configuration in which the antenna inductance is fixed and the received radio frequency is switched only by switching the capacitance. Since the impedance (ratio) when the reception radio frequency is 40 kHz is about 1 and the impedance (ratio) when the reception radio frequency is 77.5 kHz is about 4, the reception radio frequency was switched from 40 kHz to 77.5 kHz. In some cases, the impedance is changed about four times. Thus, when the width of the change in impedance is large, it becomes difficult to perform impedance matching between the antenna circuit and the receiving IC in all frequency regions of the received radio wave. That is, for example, when the value of the input impedance of the receiving IC is set in accordance with the value of the impedance of the antenna circuit when the received radio frequency is 40 kHz, the 40 kHz radio wave can be received with high sensitivity while the received radio frequency is received. When the frequency is set to 60 kHz, 77.5 kHz, etc., the impedance of the antenna circuit is greatly changed. As a result, impedance matching with the receiving IC cannot be properly obtained, and the receiving sensitivity of the antenna is deteriorated.

  On the other hand, three points in FIG. 14 indicate impedance ratio values in the antenna circuit having the configuration shown in FIG. 12 in which the received radio frequency is switched by switching both the inductance and the capacitance, and the received radio frequencies are 40 kHz, 60 kHz, and 77. Plotted against three frequencies of 5 kHz. As can be easily seen from this figure, when the antenna circuit having the configuration shown in FIG. 12 is used, the impedance of the antenna circuit is kept substantially constant even when the reception radio frequency is switched between 40 kHz, 60 kHz, and 77.5 kHz. It is. Therefore, impedance matching with the receiving IC is facilitated, and a radio timepiece having good reception sensitivity for radio waves of all three frequencies can be manufactured.

In FIG. 12, the frequency of the radio wave received by the antenna 21 can be arbitrarily set by appropriately adjusting the values of La, Lb, C1, and C2.
In addition, a radio timepiece that can receive more frequencies is manufactured by dividing the antenna 21 into three or more antenna parts, or by providing three or more capacitors and changing the inductance and capacitance of the antenna circuit. You can also.
Further, the reception radio frequency may be switched by switching only the inductance of the antenna circuit.

FIG. 15 shows a specific structure of a radio-controlled timepiece incorporating the antenna circuit having the configuration shown in FIG. The conductor of the antenna 21 is made of, for example, polyurethane copper wire, and is soldered to the circuit board 800 at terminals T1, T2, and T3. Both the lead wire of the first antenna portion 21A and the lead wire of the second antenna portion 21B are soldered to the terminal T2. As shown in FIG. 16, the circuit board 800 includes the antenna 21, the high-capacity secondary power supply 72 receiving IC 81, the CPU 82, and the reference vibrator 311, and the notches 21 </ b> C, 72 </ b> C, 81 </ b> C, 82 </ b> C having substantially the same shape. 311C is formed.
Terminals T 1, T 2, T 3 and capacitors 221, 222 as circuit elements constituting the receiving means of the present invention are between a line segment LS 1 connecting the center points of both end surfaces 211 B of the core 211 of the antenna 21 and the core 211. It is arranged in the space to be formed, and the space formed by making the antenna 21 into a substantially circular arc shape is effectively used. In addition, according to such a configuration, since the conducting wire for connecting the antenna 21 and each capacitor 221, 222 can be shortened, the possibility of noise being mixed through the conducting wire can be reduced, and radio wave reception at the antenna 21 can be performed more accurately. It can be carried out. The space is not limited to a capacitor or the like, and at least a part of the circuit elements constituting the tuning circuit unit 22 or the reception circuit 23 may be disposed. For example, the reception IC 81 can also be disposed. Conversely, if the component parts other than the circuit elements constituting the tuning circuit unit 22 or the receiving circuit 23 such as the CPU 82 and the reference vibrator 311 are arranged near the antenna 21, the antenna characteristics may be adversely affected. Therefore, it is not arranged in the space. For example, if the CPU 82 is placed in the space and is brought close to the antenna 21, there is a possibility that radio wave reception by the antenna 21 may be hindered by noise generated from the core portion in the CPU 82. On the other hand, in FIG. 15, the CPU 82 is disposed outside the space and away from the antenna 21, so that noise from the CPU 82 is not mixed into the antenna 21.

  Further, the position of the antenna is not limited to the 12 o'clock direction of the timepiece in the case 9 as in each of the above-described embodiments, but other positions such as the 9 o'clock direction of the timepiece shown in FIG. It may be a position. However, the crown winding stem 100, the button shaft 101, etc. are usually provided in the 3 o'clock direction, and the antenna 21 must be disposed so as not to interfere with these. It is preferable to arrange in. In particular, as shown in FIG. 17, when buttons are arranged at 2 o'clock and 4 o'clock, when the antenna 21 is arranged in the 12 o'clock direction or 6 o'clock direction, the antenna 21 does not interfere with the shaft 101. Since the length of 21 may be limited, it is most preferable to arrange the antenna 21 in the 9 o'clock direction.

Further, the exterior case 9 in the timepiece 1 of the present invention is not limited to a metal case, and for example, as shown in FIG. 18, a metal cover 111 such as stainless steel or titanium is attached to the surface of a plastic case 110. May be good. Further, the outer case 9 may be made of a non-conductive material such as a synthetic resin or ceramic, or may be made of a metal layer formed by subjecting these plastics or the like to a surface treatment such as metallic coating. Good.
Furthermore, the back cover 93 is not limited to a metal one, and for example, as shown in FIG. 18, a glass plate 93B fitted into a metal outer ring 93A may be used. If a part of the back cover 93 is made of glass, radio waves can easily enter the exterior case 9 from the glass plate 93B, so that the receiving sensitivity can be improved. Similarly, if the dial 95 is also made of plastic, radio waves can easily enter the case 9 and reception sensitivity can be improved.

The antenna core is not limited to a laminated amorphous foil, and a magnetic material such as a ferrite core may be used.
The length of the antenna core can be set as appropriate. In particular, when the antenna core is formed in an arc shape, the central angle can be increased to about 180 degrees, and can be set to 180 degrees or more. . The antenna characteristics are improved when the antenna is longer. Therefore, when the antenna length is at least about 15 mm, the central angle may be about 50 to 60 degrees. However, it is preferable to increase the central angle in order to further improve the antenna characteristics. On the other hand, when the central angle is 180 degrees or more, there is an angular difference between the axial direction of both ends of the antenna 21, that is, the direction in which the interlinkage magnetic field (magnetic flux) enters and exits, and the direction of the magnetic flux in the intermediate portion of the antenna 21. Since it becomes 90 degrees or more and the flow of the magnetic field component becomes unsmooth, it is not preferable to increase it greatly exceeding 180 degrees. Therefore, when the length of the antenna core is formed in a circular arc shape or a polygonal shape approximate to the circular arc, it is preferable that the central angle is within a range of about 50 degrees to 240 degrees. In consideration of the above, it is preferable that the central angle is in the range of about 60 to 180 degrees. In practice, it may be set in consideration of an arrangement space of other parts such as a motor coil and a battery.
Even when the core is not formed in an arc shape, the positional relationship between the end faces may be the same as in the arc shape.

Furthermore, the present invention is not limited to the analog radio wave correction timepiece 1 and may be applied to a digital radio wave correction timepiece 1A. As shown in FIG. 19, the digital radio-controlled timepiece 1A includes an antenna 21, a receiving circuit 23, a time data storage circuit unit 24, a drive control circuit unit 3, a pulse synthesizing circuit 31, a battery 73 as a power supply means 7, It has the same configuration as the radio wave correction timepiece 1 such as an external input device 8 such as a crown. Further, a time counter 630 is provided in the drive control circuit unit 3, and the time data of the time counter 630 is configured to be displayed on the liquid crystal panel 430 as time display means via the drive circuit 43 of the liquid crystal panel. Yes.
The value of the time counter 630 changes according to the pulse signal from the pulse synthesizing circuit 31, and when it is determined that the time data received by the receiving circuit 23 and stored in the time data storage circuit unit 24 is correct, Updated with the time data.

  Also in such a digital radio wave correction watch 1A, if both ends of the core of the antenna 21 are arranged along the case inner peripheral surface 91A, the antenna characteristics can be improved, and the exterior case 9 can be Even when it is made of metal, it can receive radio waves. Further, in the case of a digital timepiece, it can be constituted by a liquid crystal panel 430, a circuit board, a battery 73, etc., and has a smaller number of parts than an analog timepiece, so that a very thin timepiece 1A can be obtained.

Moreover, in the said embodiment, although the antenna 21 and the battery 72 were arrange | positioned on the opposite side on both sides of the center point O, it is not necessarily limited to such an arrangement, You may arrange | position closer. Similarly, the positional relationship between the reference vibrator 311 and the antenna 21 is not limited to the above embodiment, and for example, the distance between the battery 72 or the reference vibrator 311 and the antenna 21 may be equal to or less than the distance W1.
Further, when the core 211 is made of an amorphous foil, in the embodiment, as shown in FIG. 2, the amorphous foil is formed in a plane arc shape and laminated in the thickness direction (longitudinal direction) of the watch 1. However, the core may be manufactured by forming an amorphous foil in a planar rectangular shape and laminating it in the plane direction of the watch (the direction perpendicular to the thickness direction of the watch, that is, the lateral direction). In this case, it is necessary to bend each amorphous foil, but since the amorphous foil is a thin film, there is no problem because it can be bent relatively easily. In addition, each amorphous foil need not be formed into a planar arc shape, and can be formed into a planar rectangular shape (rectangular shape), so that each amorphous foil, that is, the core can be easily and efficiently manufactured.
In each of the above embodiments, the coil is wound up to the vicinity of both end faces 211B of the core 211. However, the coil may be wound only in an intermediate portion (center portion) of the core. However, in terms of antenna characteristics and space efficiency, it is preferable to wind the coil to the vicinity of both ends of the core as in the above embodiment.

  Further, the radio information received by the antenna 21 is not limited to the long wave standard radio wave including time information. For example, even when receiving time information, a weak radio wave of 300 MHz band, a specific low power radio of 400 MHz band, Bluetooth (Bluetooth) of 2.4 GHz band, or the like may be used as the radio signal. When receiving these radio waves, since the frequency is high, the number of turns of the coil 212 may be small, and the antenna 21 can be made small.

  In addition to the wireless communication using radio waves, other wireless communication methods such as an electromagnetic coupling method and an electromagnetic induction method may be used. Note that the electromagnetic coupling and electromagnetic induction methods require communication devices to be close to each other. However, if a non-magnetic material such as stainless steel is used, it is possible to communicate through a metal part. There exists an advantage which can be comprised with metal, such as.

Furthermore, radio information communicated using the antenna 21 is not limited to time information. For example, an IC card function may be built in the watch 1 and used to transmit and receive information such as train commuter passes and various prepaid IC cards. For example, an IC chip and an antenna may be incorporated in the case 9 so that information can be exchanged by placing a wristwatch close to a ticket gate using a smart card, an entrance / exit management machine, various billing machines, or the like. In this case, it is not necessary to insert and remove the IC card separately, and it is only necessary to bring the hand with the watch close to it, so that the operability can be greatly improved.
Therefore, the antenna 21 incorporated in the outer case 9 of the present invention may be used exclusively for reception as in the case of receiving a standard radio wave, or transmits and receives information like a tag using a non-contact IC. May be used exclusively for transmission, or may be used exclusively for transmission, and these may be appropriately selected according to the type of electronic timepiece to which the present invention is applied, that is, the electronic device with a built-in antenna.

The electronic apparatus with a built-in antenna according to the present invention is not limited to the above-described radio-controlled timepiece, and can be applied to various electronic apparatuses such as an electronic apparatus provided with only the IC card function. For example, electronic devices include measuring devices such as pulse and body temperature, communication, communication devices having a call function, calendars and schedules, portable information terminal devices having an address book function, portable computers having an electronic calculation function, The present invention can be applied to electronic devices having various wireless information communication functions, such as music and image, AV equipment having a video playback function, and personal information management equipment having a non-contact communication function.
Also in these electronic devices, for example, a liquid crystal display unit or the like is provided in the main body so that information received by an antenna incorporated in the outer case 9 or transmitted to the outside, for example, information such as balance information and usage history is displayed. It may be. Furthermore, the user ID information may be communicated from the electronic device, and the information may be provided to the user from the system side communicating with the electronic device. For example, when getting in and out of transportation, entering or leaving an event venue or store, or going to or going to a company, a message is sent to all users, or a special message (specified by ID) ( Benefit point guidance, event information) may be sent.

  The antenna 21 is not limited to a loop antenna, and other antennas such as a derivative antenna may be used, and these may be set as appropriate according to the type of wireless information to be transmitted or received. In addition, when using a loop antenna, you may use the thing in which the magnetic body core is not inserted.

It is a block diagram which shows the structure of 1st Embodiment of this invention. It is a perspective view which shows the structure of the antenna of the said embodiment. It is a block diagram which shows the structure of the receiving circuit of the said embodiment. It is a schematic plan view of the timepiece of the embodiment. It is a schematic sectional drawing of the timepiece of the embodiment. It is a conceptual diagram explaining reception of the electromagnetic wave by an antenna. It is a circuit diagram which shows the drive circuit of a motor. It is a schematic plan view of the timepiece of the second embodiment of the present invention. It is a perspective view which shows the modification of the antenna of this invention, (A) is a perspective view of a core, (B) is a perspective view of the antenna which consists of a core and a coil. It is a schematic plan view which shows the other modification of the antenna of this invention. It is a schematic plan view which shows the other modification of the antenna of this invention. It is a block diagram which shows the modification of the antenna of this invention, and a tuning circuit part. It is a figure which shows the correspondence of ON / OFF of each switch in FIG. 12, and a received radio wave frequency. It is a graph which shows the relationship between a received radio wave frequency and the impedance of an antenna circuit. FIG. 13 is a schematic plan view of a timepiece including the antenna and the tuning circuit unit in FIG. 12. It is a schematic plan view which shows the example of the circuit board of this invention. It is a schematic plan view which shows the other modification of this invention. It is a schematic sectional drawing which shows the other modification of this invention. It is a block diagram which shows the structure of the digital timepiece which is the other modification of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,1A ... Radio wave correction clock, 2 ... Receiving means, 3 ... Drive control circuit part, 4 ... Drive means, 9 ... Outer case, 21, 51, 52, 53, 54 ... Antenna, 71 ... Power generation device, 72 ... High Capacity secondary power source 73 ... Battery 80, 800 ... Circuit board 91 ... Casing 91A ... Inner peripheral surface 92 ... Cover glass 93 ... Back cover 93A ... Outer ring 93B ... Glass plate 95 ... Dial 96 ... Ground plate, 100 ... Winding stem, 101 ... Button shaft, 110 ... Plastic case, 111 ... Metal cover, 211, 511, 521, 531, 541 ... Magnetic core, 211A, 511A, 521A, 531A ... End 212, 512, 522, 532, 542 ... coil, 311 ... reference vibrator, 411 ... second motor, 421 ... hour / minute motor, 430 ... liquid crystal panel, 511B, 521B, 531 ... middle part.

Claims (1)

An exterior case made of at least a part of metal, an antenna arranged in the exterior case for receiving external wireless information, a receiving means for processing external wireless information received by the antenna, and a time display means Prepared,
The antenna is composed of a core and a coil wound around the core, and at least both ends of the core are arranged along the inner peripheral surface of the outer case,
The antenna is configured by connecting a first antenna unit having an inductance La and a second antenna unit having an inductance Lb in series,
Two capacitors connected in parallel to the antenna are provided;
A drive control circuit that controls a switch connected in parallel to the second antenna unit and a switch connected in series to the one capacitor to change the impedance of the antenna circuit including the antenna and the capacitor An electronic timepiece with a built-in antenna, characterized by comprising a portion.

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