JP5228608B2 - Electronic clock with built-in antenna - Google Patents

Description

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

  Conventionally, an electronic timepiece with a built-in antenna such as a radio-controlled timepiece that receives external wireless information having time information from the outside by an antenna and performs processing such as time correction is known. In such an electronic timepiece with a built-in antenna, in order to improve antenna characteristics, various configurations for improving the magnetic flux collecting effect in the antenna are considered (for example, see Patent Documents 1 and 2).

  The wristwatch described in Patent Document 1 includes a built-in antenna including a laminated core portion, a winding portion in which a winding is wound around the laminated core, and end caps fixed to both ends of the laminated core portion. It is taken.

  Moreover, the wristwatch described in Patent Document 2 includes a core, a core case that houses the core, a coil that is wound around the core case, and an amorphous thin film that is attached to a position where the coil of the core is not wound. The composition with which it was equipped is taken.

JP 2005-269234 A JP 2007-184894 A

By the way, in the conventional configuration in which the end caps are attached to both ends of the laminated core portion of the antenna as described in Patent Document 1, the timepiece module is increased in size by the amount of the end cap, making it difficult to reduce the thickness and size of the timepiece. There's a problem.
Further, in the configuration in which the amorphous thin film is fixed to the core as described in Patent Document 2, there is a problem that the amorphous thin film is easily damaged when an impact is applied to the timepiece. Although it is possible to prevent the amorphous thin film from being damaged by providing a structure such as newly providing a holding member, there is a problem that the size of the timepiece is increased when such a holding member is provided.

  In view of the above problems, an object of the present invention is to provide an electronic timepiece with a built-in antenna capable of improving antenna characteristics without increasing the timepiece size.

An electronic timepiece with built-in antenna according to the present invention includes an elongated magnetic core formed of a magnetic material, a coil wound around the magnetic core, and an antenna capable of receiving external wireless information; An electronic timepiece with a built-in antenna comprising a dial plate formed of a non-conductive material, wherein the magnetic core is provided at a central portion in a longitudinal direction and the coil is wound thereon A coil winding portion and a pair of lead portions projecting from both ends of the coil winding portion; the module includes a ground plate facing the dial; and the antenna includes a recess for fixing the magnetic core. An antenna frame having an opening end of the concave portion in contact with the ground plane so that the magnetic core and the ground plane are arranged with a gap between the antenna frame and the ground plane. Fixed, the surface opposite to the dial of the base plate in a plan view to see the surface direction of the dial, in a position not overlapping the coil-overlapping area that overlaps the coil winding part of the antenna, and a pair of A magnetic member having a magnetic permeability higher than that of the dial is provided at a position overlapping at least a part of a lead overlapping region overlapping with the lead portion.

According to this invention, the magnetic member is provided at a position that does not overlap the coil overlap region between the module and the dial and overlaps the lead overlap region. Here, the coil overlap region and the lead overlap region are a region that overlaps with the coil winding portion of the antenna and a region that overlaps the lead portion in a plan view in which the surface direction of the dial is viewed. In the timepiece thickness direction, the region is sandwiched between the dial and the module (including the face of the dial facing the module and the face of the module facing the dial). Accordingly, the position overlapping with the lead overlapping area without overlapping with the coil overlapping area may be, for example, the surface facing the module of the dial plate as long as the position does not overlap with the coil and overlaps with the lead portion in the plan view. It may be a surface facing the dial plate of the module, and may be provided between the dial plate and the module.
According to the present invention, since the magnetic member having a larger magnetic permeability than the dial is provided in the lead overlapping region adjacent to the lead portion, many magnetic flux lines can be collected by this magnetic member. Magnetic flux lines can be guided from the lead portion into the magnetic core. Therefore, the magnetic flux collection effect in the antenna can be improved, and the reception characteristics can be improved. At this time, since no magnetic member is provided in the coil superposition region, the magnetic flux lines can be effectively collected in the lead portions at both ends of the magnetic core, and the magnetic field extending from one end to the other end of the magnetic core can be collected. A path can be easily formed. Thereby, the receiving performance of an antenna can be improved more.
Further, in many cases, a wristwatch or the like generally has an exterior case or a back cover made of metal. In this case, an external wireless device such as a standard radio wave from a windshield glass of a non-conductive member disposed on the dial side of the watch. Information enters. In such a timepiece, by providing the magnetic member between the dial and the module as described above, the magnetic flux lines generated along with these external wireless information can be collected well by the magnetic member. As compared with the case where the is provided on the back cover side, better reception characteristics can be obtained.
In addition, due to the structure of the watch, a drive mechanism for driving time display means such as hands is often incorporated on the back cover side of the module, and a watch member is disposed on the dial side of the module. Less is. Therefore, other timepiece members are rarely disposed between the module and the dial, and a sufficient space for providing the magnetic member can be easily secured.

Further, according to this invention, the magnetic member is provided in the surface facing the dial of the main plate. As described above, the timepiece member is rarely disposed between the main plate and the dial, and a sufficient space for providing the magnetic member can be provided on the surface of the main plate facing the dial. Accordingly, a concave portion for arranging the magnetic member can be easily formed on the surface of the main plate facing the dial plate, and the surface of the main plate facing the dial plate by arranging the magnetic member in such a concave portion. Can be made flat. Therefore, when the timepiece is assembled, since the main plate has no irregularities, the surface of the main plate facing the dial plate can be brought into close contact with the dial plate, and the watch can be made thinner.
Furthermore, by sticking the magnetic member to the ground plate, the magnetic member can be easily fixed at an appropriate position corresponding to the position of the antenna, and the manufacturing efficiency can be improved.
In addition, by providing the module with a magnetic member, it is possible to easily measure the antenna tuning frequency and the antenna reception sensitivity before incorporating the module into the case.

Furthermore, in the electronic timepiece with built-in antenna of the present invention, it is preferable that the magnetic member is an amorphous foil material made of an amorphous metal.
Here, examples of the metal magnetic foil material in the present invention include cobalt-based amorphous (Co—Fe—Ni—B—Si).
Amorphous metal has a magnetic permeability much higher than that of the dial when the dial is made of a low magnetic permeability such as synthetic resin or ceramic. Therefore, by using the amorphous foil material, the magnetic flux collecting effect can be further increased, and the magnetic flux lines input from the lead portion of the magnetic core into the antenna can be increased, thereby further improving the antenna characteristics.

In the electronic timepiece with built-in antenna of the present invention, it is preferable that the magnetic member is formed in an area larger than the lead overlapping region in the plan view.
According to the present invention, by using a magnetic member having a larger area than the lead overlapping region, it is possible to further increase the magnetic flux collection effect and increase the amount of magnetic flux lines passing between the pair of lead portions of the magnetic core. . Therefore, antenna characteristics such as the reception sensitivity of the antenna can be improved, and the antenna characteristics can be improved.

In the electronic timepiece with built-in antenna according to the present invention, the module includes a base plate for fixing the antenna, and the magnetic member is attached and fixed to a surface corresponding to the dial of the base plate via an adhesive layer. It is preferable.
According to the present invention, the magnetic member can be easily fixed via the adhesive layer formed of an adhesive or the like. Further, in the fixing with the adhesive layer, the thickness dimension can be reduced as compared with the holding structure made of synthetic resin or the like. Thereby, the clearance gap between a dial and a module can be made smaller, and thickness reduction of an electronic timepiece with a built-in antenna can be achieved. In addition, in the configuration in which a concave portion is formed on the base plate and a magnetic member is attached and fixed to the concave portion, the depth of the concave portion can be reduced, the formation of the base plate can be simplified, and the arrangement space for other watch parts inside the base plate Can contribute to making the watch thinner.

In the electronic timepiece with built-in antenna according to the present invention, it is preferable that a plurality of the magnetic members are stacked.
According to this invention, by laminating the magnetic members, the thickness dimension of the magnetic members is increased, and more magnetic flux lines can be collected. Therefore, the antenna characteristics can be further improved by improving the magnetic flux collecting effect.

In the electronic timepiece with built-in antenna according to the present invention, the ground plate communicates at least a part facing the lead portion with a lead facing surface facing the lead portion and a dial facing surface facing the dial. The magnetic member is formed in an area larger than the lead overlap region on the dial-facing surface of the base plate, and a magnetic flux collecting portion provided to cover the communication hole; and the communication hole It is good also as a structure provided with the magnetic field output part laminated | stacked and formed in the state which penetrates and protrudes toward the said lead part from the surface facing the said antenna of the said magnetism collection part.
According to the present invention, the magnetic flux lines can be efficiently collected by the magnetic flux collecting portion provided on the surface of the main plate facing the dial plate, and the collected magnetic flux lines are laminated on the communication hole by the magnetic field output portion. It can guide to the surface which opposes the lead part. Therefore, the magnetic flux lines can be guided to the lead portion more efficiently, and the antenna characteristics can be further improved.

And in the electronic timepiece with built-in antenna of the present invention, the module is provided on a ground plate on which the antenna is disposed and a surface of the ground plate facing the dial, and from a date display window provided on the dial. It is preferable that at least one date indicator that displays a date is provided, and the magnetic member is provided at a position that does not overlap the date indicator between the main plate and the dial.
According to the present invention, in the electronic timepiece with a built-in antenna capable of displaying the date by driving the date wheel provided between the main plate and the dial, the magnetic member is provided between the main plate and the dial. That is, in the configuration in which the date dial is provided, a gap of a predetermined dimension is required between the dial and the main plate by the thickness dimension of the date dial, and in this case, no date dial is provided between the dial and the main plate. Sufficient space can be secured in the part. Therefore, by providing a magnetic member in this space, the space can be effectively used, and it is not necessary to form a concave portion or the like for providing the magnetic member on the ground plane, and the configuration can be simplified.

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

In FIG. 1, the radio-controlled timepiece 1 is a pointer-type timepiece (analog timepiece) provided with hands 11, 12, 13 and a dial 14, and receives a long-wave standard radio wave as external wireless information having time information, The timepiece 11, 12, 13 can correct the position of the hands based on the received time information.
The radio-controlled timepiece 1 includes a pointer 10, 12, 13, a dial 14, an antenna 21 that receives standard radio waves, and a module 10 in which various configurations for controlling the driving of the hands 11, 12, 13 are incorporated (FIG. 2). And an exterior case 100 that accommodates these pointers 11, 12, 13, dial 14, module 10, and the like.
Here, the dial plate 14 is preferably formed of a non-conductive material such as synthetic resin or ceramic, for example, so that the standard radio wave entering from the windshield side is not hindered, and the antenna 21 described later is not obstructed. Can be received well.

[Module configuration]
A module 10 constituting the radio-controlled timepiece 1 will be described with reference to FIGS.
FIG. 2 is a plan view showing a schematic configuration of the inside of the radio-controlled timepiece according to the first embodiment viewed from the back cover side.
FIG. 3 is a block diagram showing a schematic configuration of the radio-controlled timepiece according to the first embodiment.
FIG. 4 is a block diagram showing the configuration of the receiving circuit unit of the radio-controlled timepiece according to the first embodiment.
FIG. 5 is a side cross-sectional view of the radio-controlled timepiece according to the first embodiment when cut in the thickness direction.
FIG. 6 is a cross-sectional view of the vicinity of the antenna in the radio-controlled timepiece according to the first embodiment.
FIG. 7 is a front view of the dial-facing surface of the main plate constituting the module of the radio-controlled timepiece according to the first embodiment.

The module 10 has a circular shape in plan view and has a module middle frame 101 (see FIG. 5) made of synthetic resin, and is fitted and fixed to the inner peripheral side of the outer case 100, for example.
In addition, when a plurality of projecting portions are provided on the outer peripheral surface of the module middle frame 101 and stored in the outer case 100, the position is fixed by abutting these projecting portions with the inner surface of the outer case 100, etc. It is good.

  Further, the module 10 includes a circuit board 80 (see FIG. 5) in which a receiving IC 86, a CPU 87, a reference vibrator 311 (see FIG. 3), and the like are mounted inside the module middle frame 101, and a part of the driving unit 4. Components such as a timepiece (movement) incorporating motors 411, 421 and a train wheel constituting the same, a high-capacity secondary power source (secondary power source) 72 constituting the power supply means 7, and the antenna for receiving radio waves 21 and a main plate 102 that supports the clock body, the antenna 21, and the like are incorporated. Here, each component such as the circuit board 80, the watch body, the secondary power source 72, and the antenna 21 is disposed on the back cover side of the main plate 102. As shown in FIG. 6, the module 10 has a dial plate facing surface 103 that faces the dial plate 14 of the main plate 102 in a state in which the dial plate facing surface 103 is in close contact with the solar cell 15 provided on the back surface of the dial plate 14. It is stored in.

  Further, as shown in FIG. 3, the circuit board 80 includes a receiving means 2 for processing received radio waves, a drive control circuit section 3, a driving means 4 for driving a pointer, and a counter section 6 for counting time. Are provided as various circuit configurations.

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

As shown in FIG. 4, 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. 4, the reception circuit unit 23 includes an amplification circuit 231 that amplifies the longwave standard radio signal received by the antenna 21, and a bandpass filter that extracts only a desired frequency component from the amplified longwave standard radio signal. 232, a demodulation circuit 233 that smoothes and demodulates the long wave standard radio signal, an AGC (Automatic Gain Control) circuit 234 that controls the gain of the amplification circuit 231 and controls the reception level of the long wave standard radio signal to be constant, And a decoding circuit 235 that decodes and outputs the demodulated long-wave standard radio signal.
The time data received and signal-processed by the receiving circuit unit 23 is output to and stored in the time data storage circuit unit 24 as shown in FIG.
The reception circuit unit 23 starts receiving time information based on a reception control signal output from the drive control circuit unit 3 by a preset schedule, a forced reception operation by the external input device 8, or the like.

  As shown in FIG. 3, the drive control circuit unit 3 receives a 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 reference vibrator 311 is connected to the CPU 87 and becomes a clock signal of the circuit. However, since the frequency is close to the long wave reception frequency and there is a possibility that a signal is mixed in the antenna 21 as noise, it is separated from the antenna 21. Are arranged.

  The drive control circuit unit 3 outputs a second drive pulse signal PS1 that is output once per second to drive the second hand and an hour / minute drive pulse signal PS2 that is output once per minute to drive the hour / minute hand. And output to the hour / minute drive circuit 42. The drive circuits 41 and 42 drive the second motor 411 and the hour / minute motor 421 that are stepping motors based on the pulse signal input from the drive control circuit 3. As a result, the second hand, the minute hand, and the hour hand connected to these motors 411 and 421 are driven. Each pointer, dial 14, 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. The second position counter 611 and the second time counter 612 are both 60 counts, that is, a counter that loops in 60 seconds when a 1 Hz signal is input. The second position counter 611 counts the drive pulse signal (second drive pulse signal PS1) supplied from the drive control circuit unit 3 to the second drive circuit 41. That is, the position of the second hand indicated by the second hand is counted by counting the drive pulse signal for driving the second hand.
The second time counter 612 normally counts a 1 Hz reference pulse signal (clock pulse) output from the drive control circuit unit 3. When the time data is received by the receiving means 2, the counter value is corrected according to the second data of the time data.

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

The coincidence detection circuits 613 and 623 detect 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.
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, if the counter values of the time counters 612 and 622 are changed by the 1 Hz reference signal 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 output. As the hands move, the position counters 611 and 621 coincide with the time counters 612 and 622. By repeating this operation, normal hand movement control is performed.
Further, when the time counters 612 and 622 are corrected with the received time data, the drive pulse signals PS1 and PS2 continue to be output until the counter values of the position counters 611 and 621 coincide with the counter values, and the pointer is fast-forwarded. Is corrected to the correct time.

  The power supply means 7 includes a high-capacity secondary power source 72 that is connected to the solar cell 15 that is attached and fixed to the back surface (side surface of the module 10) of the dial plate 14 and that stores the power generated by the solar cell 15. It is configured. The high-capacity secondary power source 72 can use a secondary power source such as a lithium ion battery. As the power supply means 7, a primary battery such as a silver battery may be used. In addition, the high-capacity secondary power source 72 is configured by a stainless steel case, and in order to suppress the influence on the antenna characteristics, as shown in FIG. It is arranged at the position. The solar cell 15 is a low-permeability solar cell panel that does not affect the reception of standard radio waves.

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

As shown in FIG. 6, the antenna 21 includes a magnetic core 211, a coil 212 wound around the magnetic core 211, and an antenna frame 213 that holds the magnetic core 211.
As shown in FIG. 2, the antenna 21 is formed in a circular arc shape having a planar shape that is substantially concentric with the inner periphery of the casing 110 constituting the trunk of the exterior case 100, and is formed on the inner surface of the module middle frame 101. Along the 9 o'clock direction of the watch.

The magnetic core 211 is formed in a longitudinal shape along the longitudinal direction of the antenna 21. The magnetic core 211 includes a coil winding portion 211A around which a coil 212 is wound and a lead portion 211B extending from both ends of the coil winding portion 211A.
The magnetic core 211 is formed by, for example, punching a cobalt-based amorphous foil (eg, amorphous foil of Co 50 wt% or more) as a magnetic foil material with a mold or bonding and bonding 10 to 30 pieces formed by etching. In addition, heat treatment such as annealing is performed to stabilize the magnetic characteristics. That is, the magnetic core 211 is configured by laminating planar amorphous foils in the thickness direction of the watch. Note that the magnetic core 211 is not limited to the laminated amorphous foil, and ferrite may be used. In this case, the magnetic core 211 may be formed by a mold or the like and heat-treated.

  Further, the magnetic core 211 is held by an antenna frame 213 as shown in FIG. The antenna frame 213 includes a core holding magnetic member installation recess 213A corresponding to the shape of the magnetic core 211. The magnetic core 211 is bonded and fixed to the antenna frame 213 through an adhesive layer formed of, for example, an adhesive in the core holding magnetic member installation recess 213A. Further, a fixing portion (not shown) is provided at an end portion of the antenna frame 213, and the antenna 21 is incorporated in the module 10 by fixing the fixing portion to the ground plate 102. At this time, the antenna frame 213 is fixed to the ground plane 102 so that the opening of the core holding magnetic member installation recess 213 </ b> A faces the ground plane 102. As a result, the magnetic core 211 can be disposed closer to the dial side that is the incoming direction of the standard radio wave. At this time, the magnetic core 211 is fixed to the ground plane 102 with a predetermined gap between the magnetic core 211 and the ground plane 102. Thereby, when an impact or the like is applied to the radio-controlled timepiece 1, the impact from the ground plane 102 is not directly applied to the magnetic core 211, and the antenna 21 is prevented from being damaged.

  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 the present embodiment, a uremet wire having a diameter of about 0.1 μm is wound as the coil 212 for several hundred turns.

  Here, as shown in FIG. 7, a region that overlaps the coil 212 in the plan view of the radio-controlled timepiece 1 viewed from the thickness direction is defined as a coil overlap region 104. Further, an area overlapping with the lead part 211B is defined as a lead overlapping area 105.

  The antenna 21 and the receiving IC 86 are connected by two wires. That is, the antenna 21 and the receiving IC 86 are electrically connected by taking out the coil 212 from the end of the antenna and soldering it to the circuit board 80. As a result, the standard radio wave received by the antenna 21 can be output to the receiving means 2. The electrical connection may be performed by attaching a flexible substrate made of polyimide or the like to the antenna 21 and screwing the substrate to the circuit board 80.

As shown in FIGS. 6 and 7, an amorphous foil material 140 as a magnetic member is attached and fixed to the dial facing surface 103 of the base plate 102 facing the dial 14.
Specifically, on the dial-facing surface 103 of the base plate 102, a coil overlapping region that is superimposed on the coil 212 of the antenna 21 in a plan view of the inside of the radio-controlled timepiece 1 viewed from the clock thickness direction as shown in FIG. Magnetic member installation recesses 102A are provided at positions that do not overlap with 104 and overlap with a part of the pair of lead overlapping regions 105 that overlap with the pair of lead portions 211B, respectively. An amorphous foil material 140 is stuck and fixed. Here, the pair of amorphous foil materials 140 are formed so as to extend in the protruding direction of the lead portion 211B (a direction away from the coil 212) in the plan view. That is, the amorphous foil material 140 is formed in an area larger than the lead overlap region 105. Further, these amorphous foil materials 140 are fixedly attached to the dial facing surface 103 via an adhesive layer.

  Examples of the amorphous foil material 140 include cobalt-based amorphous (Co—Fe—Ni—B—Si). The amorphous foil material 140 is, for example, cobalt-based amorphous (Co—Fe—Ni—B—Si), has a relative magnetic permeability of 20000, and has a magnetic permeability much higher than that of the dial 14 and the solar cell 15. doing. Therefore, the magnetic flux lines around the amorphous foil material 140 are collected to increase the magnetic field, and the magnetic flux lines passing from the amorphous foil material 140 to the inside of the magnetic core 211 via the lead portions 211B increase.

Here, when the amorphous foil material 140 is provided on the ground plane 102, the amorphous foil material 140 is provided at a position overlapping both the coil overlapping region 104 and the lead overlapping region 105, and the amorphous foil material 140 is overlapped on the coil overlapping region. FIG. 8 shows a measurement result of measuring the reception sensitivity of the antenna 21 when the antenna is provided at a position that does not become a position and overlaps with the lead overlap region.
As shown in FIG. 8, when the amorphous foil material 140 is provided at a position overlapping the coil overlapping region, no improvement in reception sensitivity was observed. That is, when a part of the amorphous foil material 140 is superimposed on the coil overlapping region 104, the distance from the amorphous foil material 140 to the coil 212 is reduced, and the portion of the amorphous foil material 140 that is overlapped with the coil overlapping region is collected in the coil 212. It can be seen that the flux lines escape, the reception sensitivity is not improved, and the effect of improving the antenna characteristics cannot be obtained. On the other hand, when the amorphous foil material 140 is provided at a position that does not overlap the coil overlapping area and at a position that overlaps the lead overlapping area, the reception sensitivity of the antenna 21 can be improved by 2 dB compared to the case where the amorphous foil material 140 is not provided. confirmed.

[Configuration of exterior case]
Next, the configuration of the exterior case 100 of the radio-controlled timepiece 1 will be described.
As shown in FIGS. 2 and 5, the outer case 100 includes a casing 110, a windshield 120 mounted on the front surface side of the casing 110, and a metal detachably attached to the back surface (lower end surface) side of the casing 110. And a back cover 130 made of metal. The casing 110 is made of a metal material such as stainless steel, brass, or titanium. The casing 110 is formed in a substantially cylindrical shape, and the inner peripheral surface is formed in a substantially circular plane. Note that the back cover 130 and the casing 110 may be provided with a magnetic member for preventing an eddy current caused by a sub magnetic path generated by receiving radio waves with the antenna 21.

[Effects of radio-controlled clock]
As described above, in the radio-controlled timepiece 1 of the first embodiment described above, it does not overlap the coil overlap region 104 and overlaps the pair of lead overlap regions 105 between the dial 14 and the base plate 102 of the module 10. An amorphous foil material 140 having a higher magnetic permeability than the dial 14 and the solar battery 15 is provided at the position.
For this reason, many magnetic flux lines can be collected by this amorphous foil material 140, the collected magnetic flux lines can be guided to the lead part 211B, and the magnetic flux collecting effect in the antenna 21 can be improved. In addition, since the amorphous foil material 140 is not provided in the coil overlap region, the magnetic flux lines collected by the amorphous foil material 140 do not escape to the coil 212 and concentrate the magnetic flux lines on the lead portion 211B of the magnetic core 211. be able to. Accordingly, the amount of magnetic flux lines passing through the inside of the magnetic core 211 is increased and the magnetic flux density is increased, so that the antenna characteristics of the antenna 21 can be improved.
Further, in the case of using a back cover made of metal, if the antenna 21 is arranged close to the back cover, it is affected by eddy currents and reception sensitivity is lowered. In order to avoid this, it is preferable to arrange the antenna 21 on the dial 14 side away from the back cover as in the present embodiment, and in this case, between the dial 14 and the module 10 as described above. By providing the amorphous foil material 140, generation of eddy current due to the sub magnetic path generated in the antenna 21 can be suppressed, and the antenna characteristics can be improved.
Further, in the module 10, the circuit board 80, the clock body driving means, the motor, the train wheel, and the like are provided on the back cover side of the main plate 102, and are arranged on the dial facing surface 103 of the main plate 102. Since there are a small number of other watch parts, providing the amorphous foil material 140 in this space can secure a sufficient space for attaching the amorphous foil material 140 without pressing the space of other members. it can. Therefore, the area of the amorphous foil material 140 can be increased, and the magnetic flux collection effect can be further enhanced.

Further, the amorphous foil material 140 is attached and fixed to the magnetic member installation concave portion 102 </ b> A formed on the dial facing surface 103 of the base plate 102. That is, as described above, each driving means, motor, train wheel, secondary power source 72 and the like constituting the circuit board 80 and the watch body are disposed on the back cover side of the base plate 102 in the module 10. A timepiece constituent member is not disposed on the dial facing surface 103 side. For this reason, a sufficient area for attaching the amorphous foil material 140 can be secured, and the area of the amorphous foil material 140 can be increased. Therefore, more magnetic flux lines can be collected, the magnetic collection effect in the antenna 21 can be improved, and the antenna characteristics can be further improved.
Further, in the configuration in which the amorphous foil material 140 is attached to the ground plane 102, antenna characteristics such as measurement of the tuning frequency of the antenna 21 can be measured before the module 10 is housed in the casing 110. Therefore, it is possible to detect the failure of the antenna 21 at an early stage in the timepiece manufacturing process as compared with the case where the antenna characteristics are measured after the radio-controlled timepiece 1 is assembled, and to detect the failure of the antenna 21 earlier. Can do. Therefore, compared with the case where the antenna characteristics of the antenna 21 are measured after the radio-controlled timepiece 1 is assembled, the manufacturing process can be simplified, and the radio-controlled timepiece 1 can be manufactured efficiently. Further, in the configuration in which the amorphous foil material 140 is fixed to the dial plate 14, the antenna 21 and the amorphous foil material 140 are precisely aligned when the module 10 is stored after the dial plate 14 is stored in the casing 110. There is a need to. On the other hand, as described above, in the configuration in which the amorphous foil material 140 is attached to the ground plane 102, the fixed position of the antenna 21 on the ground plane 102 is set in advance. Matching can be performed easily. Therefore, the manufacturing efficiency of the radio-controlled timepiece 1 can be further improved.

  Moreover, the amorphous foil material 140 is used as a magnetic member. This amorphous foil material 140 has a value that is much higher in magnetic permeability than timepiece components other than the magnetic core 211 of the antenna 21, such as the dial plate 14, the solar cell 15, the casing 110, the back cover 130, and the like. For this reason, surrounding magnetic flux can be efficiently collected on this amorphous foil material 140. Therefore, the amount of magnetic flux lines input from the amorphous foil material 140 to the magnetic core 211 via the lead portion 211B is increased, and the magnetism collecting effect of the antenna 21 is improved, so that the antenna characteristics can be improved.

Furthermore, the amorphous foil material 140 extends in the extending direction of the lead portion 211B and is formed in an area larger than the lead overlapping region.
For this reason, the magnetic flux lines collected by the amorphous foil material 140 increase, and the magnetic flux lines input to the lead portion 211B also increase. Therefore, the magnetic flux density at the center of the magnetic core 211 is also increased, and the receiving sensitivity can be further improved.

  Furthermore, the amorphous foil material 140 is formed in a foil shape, and is fixed by pasting with an adhesive layer. For this reason, compared with the structure using the conventional magnetic sheet which mix | blended the amorphous metal with the resin sheet, for example, the thickness dimension of the amorphous foil material 140 and an adhesion layer can fully be made small, and it is affixed on the back surface of the dial plate 14, and is fixed. It can be easily provided in a slight gap between the solar cell 15 and the ground plane 102. Therefore, the thickness dimension of the radio-controlled timepiece 1 does not increase, and the design can be improved.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to the drawings. In the following drawings and embodiments, the same components as those of the radio-controlled timepiece 1 of the first embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
FIG. 9 is a cross-sectional view showing a cross section near the lead portion of the antenna in the radio wave correction timepiece according to the second embodiment.

  A radio-controlled timepiece 1A according to the second embodiment is obtained by laminating a plurality of amorphous foil materials 140 formed on the base plate 102 according to the first embodiment.

That is, as shown in FIG. 9, the ground plate 102 in the radio-controlled timepiece 1 </ b> A of the second embodiment has a plurality of amorphous foil materials at positions that do not overlap the coil overlap region 104 and overlap the lead overlap region 105. 140 is laminated to form an amorphous foil layer 141.
In this case, the magnetic member installation recess 102A is provided on the dial facing surface 103 of the base plate 102, as in the first embodiment. Here, when the amorphous foil layer 141 is formed according to the number of layers of the laminated amorphous foil material 140, the depth dimension of the magnetic member installation recess 102A is the same as the dial facing surface 103 of the base plate 102 and the amorphous foil. The surface of the layer 141 facing the dial plate 14 is appropriately set so as to be a substantially flat surface. And these amorphous foil materials 140 are mutually adhere | attached by the contact bonding layer by an adhesive agent, and it adheres and fixes to the ground plane 102 through an contact bonding layer similarly to 1st embodiment.

[Effects of the radio-controlled timepiece according to the second embodiment]
As described above, in the radio-controlled timepiece 1A according to the second embodiment, the dial plate facing surface 103 of the main plate 102 is positioned so as not to overlap the coil overlapping region 104 and overlaps at least a part of the lead overlapping region 105. Thus, an amorphous foil layer 141 in which the amorphous foil material 140 is laminated is formed.
For this reason, compared with the structure where the single amorphous foil material 140 is affixed, the layer thickness dimension of the amorphous foil layer 141 can be increased, more magnetic flux lines can be collected, and the magnetic flux collecting effect can be further enhanced. it can. Therefore, the antenna characteristics of the antenna 21 can be improved.

In addition, the ground plate 102 is formed with a magnetic member installation recess 102 </ b> A having a depth dimension set according to the number of laminated amorphous foil members 140, that is, according to the thickness dimension of the amorphous foil layer 141. For this reason, the surface facing the dial 14 of the amorphous foil layer 141 and the dial facing surface 103 of the base plate 102 can be made substantially flat. Accordingly, when the module 10 is housed in the casing 110, the gap between the solar cell 15 on the back side of the dial plate 14 and the main plate 102 can be reduced, and the radio-controlled timepiece 1A can be thinned.
Further, since the depth dimension of the magnetic member installation concave portion 102A is increased, the distance between the amorphous foil layer 141 and the lead portion 211B can be shortened, and the magnetic flux lines collected by the amorphous foil layer 141 are favorably input to the lead portion 211B. Thus, the magnetic flux density passing through the central portion of the magnetic core 211 is also increased. Therefore, the magnetic flux collection efficiency by the amorphous foil layer 141 can be further improved, and the antenna characteristics can be further improved.

[Third embodiment]
Next, a third embodiment according to the present invention will be described with reference to the drawings. In the following drawings and embodiments, the same components as those of the radio-controlled timepiece 1 of the first embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
FIG. 10 is a cross-sectional view showing a cross section near the lead portion of the antenna in the radio wave correction timepiece according to the third embodiment.

In the radio wave correction watch 1B of the second embodiment, the amorphous foil layer 141 is formed by laminating the amorphous foil material 140 on the dial facing surface 103 of the base plate 102. However, in the third embodiment, The amorphous foil material 140 is laminated toward the lead portion 211B side. That is, as shown in FIG. 10, the lead overlapping region 105 of the base plate 102 communicates with the dial facing surface 103 and the lead facing surface 106 facing the lead portion 211 </ b> B in part of the magnetic member installation recess 102 </ b> A. A communication hole 102B is provided. In addition, the amorphous foil material 140 (magnet collecting part) is installed in the magnetic member installation recess 102A, as in the first embodiment.
Then, an amorphous foil material 140A is laminated on the surface facing the communication hole 102B of the amorphous foil material 140 attached and fixed to the magnetic member installation recess 102A toward the lead portion 211B, and the amorphous foil layer 141A (magnetic field output) Part) is formed. Here, a gap of a predetermined interval is provided between the surface of the amorphous foil layer 141A facing the lead portion 211B and the lead portion 211B, and damage to the lead portion 211B and the amorphous foil layer 141A is prevented. That is, when the lead portion 211B and the amorphous foil layer 141A are in contact with each other, if an impact or the like is applied to the radio wave correction watch 1B, the amorphous foil layer 141A and the lead portion 211B may collide with each other due to vibration caused by the impact and may be damaged. is there. On the other hand, by providing a gap as described above, even when an impact or the like is applied, collision due to vibration is avoided, and damage to the lead portion 211B and the amorphous foil layer 141A is prevented.

[Effects of the radio-controlled timepiece according to the third embodiment]
As described above, in the radio wave correction timepiece 1B according to the third embodiment, the amorphous foil material 140 is positioned not to overlap the coil overlap region 104 but to the lead overlap region 105 on the dial facing surface 103 of the main plate 102. Is provided. The lead overlap region 105 of the main plate 102 is formed with a communication hole 102B that communicates the dial facing surface 103 and the lead facing surface 106. The communication hole 102B is amorphous toward the lead portion 211B from the amorphous foil material 140. 140 A of foil materials are laminated | stacked and the amorphous foil layer 141A is formed.
Therefore, the magnetic flux lines collected by the amorphous foil material 140 can be favorably guided from the dial facing surface 103 side to the lead facing surface 106 side of the base plate 102 by the amorphous foil layer 141A. Further, since the amorphous foil layer 141A is provided close to the lead portion 211B, the magnetic flux lines guided to the ground plane 102 can be input to the lead portion 211B more efficiently. Therefore, the increase in the magnetic flux lines input to the lead portion 211B increases the magnetic flux density of the magnetic core 211, improves the magnetic flux collection effect, and improves the antenna characteristics.

  In addition, a gap with a predetermined interval is provided between the lead portion 211B and the amorphous foil layer 141A. For this reason, even when an impact is applied to the radio-controlled timepiece 1B, the lead portion 211B does not collide with the amorphous foil layer 141A due to vibration caused by the impact, and damage can be prevented.

[Fourth embodiment]
Next, a fourth embodiment according to the present invention will be described with reference to the drawings. In the following drawings and embodiments, the same components as those of the radio-controlled timepiece 1 of the first embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
FIG. 11 is a cross-sectional view showing a cross section near the lead portion of the antenna in the radio-controlled timepiece according to the fourth embodiment. FIG. 12 is a plan view showing the dial-facing surface of the base plate of the radio-controlled timepiece according to the fourth embodiment.

  In the radio-controlled timepiece 1C of the fourth embodiment, a date display window (not shown) for displaying the date on the dial 14 and the solar cell 15 is formed, and the module 10 has a date display as shown in FIGS. A date wheel 160 for displaying the date from the display window is provided.

The date indicator 160 includes a tenth date indicator 162 and a first date indicator 161.
In the tenth date wheel 162, “10” scales of “0”, “1”, “2”, and “3” are equally arranged in order along the outer peripheral edge of the surface facing the dial 14. In addition, on the outer peripheral edge of the 1st-place date wheel 161 facing the dial 14, “1” to “9” corresponding to “01th” to “09th”, the first scale from “10th” to “10th” “0” to “9” mid-scale corresponding to “19th”, “0” to “9” late-highest scale corresponding to “20th” to “29th”, “30th” and “ “0” and “1” end-of-month scales corresponding to “31st” are arranged in this arrangement order.
Then, the driving force transmitted from the hour / minute motor 421 is transmitted to the 1st date indicator 161 while being decelerated by a date wheel train (not shown) set to a predetermined gear ratio. As a result, the 1st date indicator 161 rotates by one scale in 24 hours, switches the date displayed from the date display window by one day, and rotates once in 31 days. In addition, the 1st place date wheel 161 is “0” in the 1st scale from “9” in the 1st scale in the beginning, “0” in the 1st scale in the middle, “0” in the late 1st scale, and the 1st scale in the late 1st scale. When switching from “9” to “0” on the 1st scale at the end of the month and “1” on the 1st scale at the end of the month to “1” on the 1st scale at the beginning of the month, A tenth interlocking engagement portion (not shown) for advancing the date wheel 162 by one scale is provided. Thereby, one of the tenth scales of the date indicator 160 to the tenth date indicator 162 and one of the first number scales of the first date indicator is displayed from the date display window, and the date is switched every day.

The date dial 160 as described above is attached to the face on the dial 14 side of the main plate 102 in the module 10. That is, in the radio-controlled timepiece 1 </ b> C, the module 10 has a gap 163 having a predetermined size between the solar cell 15 and the main plate 102, and the date wheel 160 is provided in the gap 163.
In addition, the amorphous foil material 140 is affixed and fixed at a position in the gap 163 between the ground plane 102 and the solar cell 15 that does not overlap the coil overlapping area 104 but overlaps the lead overlapping area 105 and where the date wheel 160 is not disposed. Has been. Here, the base plate 102 is not formed with the magnetic member installation recess 102A as in the first to third embodiments, and the amorphous foil material 140 protrudes from the dial facing surface 103 of the base plate 102 into the gap 163. Pasted and fixed as you want.

[Effects of the radio-controlled timepiece according to the fourth embodiment]
In the radio-controlled timepiece 1C of the fourth embodiment, the module 10 includes a date wheel 160 that can display the date from the date display window of the dial 14. The date dial 160 is disposed in a gap 163 provided between the main plate 102 and the dial 14. The amorphous foil material 140 protrudes from the dial plate facing surface 103 of the main plate 102 into the gap 163 and does not overlap the coil overlap region, does not overlap the lead overlap region 105, and does not overlap the date wheel 160. In the position.
That is, in the configuration in which the date wheel 160 is provided, the amorphous foil material 140 can be provided by effectively utilizing the gap 163 in which the date wheel 160 is disposed. Therefore, it is not necessary to provide the magnetic member installation recess 102A in the ground plane 102, the amorphous foil material 140 can be installed with a simpler configuration, and the antenna characteristics of the antenna 21 can be improved.

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

  For example, although the amorphous metal foil-shaped member which is a ferromagnetic member was used as a magnetic member, it is not limited to this. For example, the magnetic member is not particularly limited as long as it has a magnetic permeability larger than that of the dial plate 14 or the solar cell 15, and may be appropriately selected depending on the configuration of the dial plate 14 or the solar cell 15.

Moreover, although FIG. 7 and FIG. 12 were illustrated as a position where the amorphous foil material 140 is arrange | positioned, it is not limited to this. For example, the amorphous foil material 140 may be further extended to increase the area as long as it is provided at a position that does not overlap the coil overlap region 104 or the date wheel 160 and at least partially overlaps the lead overlap region. .
Furthermore, in the above-described embodiment, the configuration in which the pair of amorphous foil materials 140 is provided corresponding to the pair of lead portions 211B is shown. However, a single amorphous foil material corresponding to one of the pair of lead portions is shown. 140 may be provided. Even in this case, better antenna characteristics can be obtained as compared with the case where the amorphous foil material 140 is not provided.

  Moreover, in the radio-controlled timepiece 1B of the third embodiment, the configuration in which the communication hole 102B is provided in the base plate 102 and the amorphous foil layer 141A is laminated in the communication hole 102B is exemplified, but the present invention is not limited to this. For example, the structure may be such that the communication hole 102B is not provided in the ground plane 102 but the amorphous foil material 140A is provided on the lead facing surface facing the lead portion of the ground plane 102. Even in this case, the magnetic flux lines can be passed from the amorphous foil material 140 attached to the dial facing surface 103 to the lead portion 211B via the amorphous foil material 140A.

  Furthermore, in the first to fourth embodiments, the amorphous foil material 140 is exemplified as the magnetic member, but the present invention is not limited to this. For example, a configuration formed by a ferrite material, a configuration formed by plating by ferrite plating, or a configuration in which a resin sheet provided with a magnetic member such as an amorphous metal is attached may be used. Particularly in the case where the gap 163 is secured as in the fourth embodiment, the magnetic member can be formed in a thickness dimension that can be accommodated in the gap 163. In this case, the thickness of the resin sheet or the like Larger dimensions can also be used.

  In each of the above-described embodiments, the amorphous foil material 140 is provided on the base plate 102. However, the amorphous foil material 140 may be provided on the dial 14 or the solar cell 15. Furthermore, the position is not particularly limited as long as it does not overlap with the coil overlapping region 104 in a plan view but overlaps at least a part of the lead overlapping region 105. For example, when a date wheel train holder for holding a date wheel is arranged between the dial plate 14 and the main plate 102, an amorphous foil material 140 may be provided on the date wheel train receiver. The amorphous foil is located in a region surrounded by the surface region closest to the lead portion 211B on the back surface and the surface region closest to the lead portion 211B on the dial-facing surface 103 of the base plate 102 at a position that does not overlap the coil overlapping region 105. Any configuration may be used as long as the material 140 is provided.

  Moreover, in each said embodiment, although the example in which the solar cell 15 was fixed to the back surface of the dial 14 was shown, it is not limited to this, It is good also as a structure where the solar cell 15 is not provided.

  In addition, the specific structure and procedure for carrying out the present invention can be changed as appropriate to other structures and the like within the scope of achieving the object of the present invention.

1 is a front view of a radio wave correction timepiece as an electronic timepiece with a built-in antenna according to a first embodiment of the present invention. It is a top view which shows schematic structure which looked at the electromagnetic wave correction timepiece of said 1st embodiment from the back cover side. It is a block diagram which shows schematic structure of the electromagnetic wave correction timepiece of said 1st embodiment. It is a block diagram which shows the structure of the receiving circuit part of the electromagnetic wave correction timepiece of said 1st embodiment. It is a sectional side view at the time of making a cross section in the thickness direction of the radio-controlled timepiece of the first embodiment. It is sectional drawing which carried out the cross section of the antenna vicinity in the radio wave correction timepiece of the first embodiment. It is a front view of the dial opposing surface of the main plate which comprises the module of the radio wave correction timepiece of the first embodiment. The measurement results of the reception sensitivity of the antenna of the radio correction watch of the first embodiment and the measurement results of the reception sensitivity of the antenna of the radio correction watch in which the amorphous foil material is provided in both the coil overlap region and the lead overlap region are shown. FIG. It is sectional drawing which shows the cross section of the lead | read | reed part vicinity of the antenna in the radio wave correction watch which concerns on 2nd embodiment. It is sectional drawing which shows the cross section of the lead | read | reed part vicinity of the antenna in the electromagnetic wave correction watch which concerns on 3rd embodiment. It is sectional drawing which shows the cross section of the lead | read | reed part vicinity of the antenna in the electromagnetic wave correction timepiece which concerns on 4th embodiment. It is a top view which shows the dial plate opposing surface of the baseplate of the electromagnetic wave correction timepiece of 4th Embodiment.

Explanation of symbols

  1, 1A, 1B, 1C ... Radio correction watch as an electronic watch with built-in antenna, 10 ... Module, 14 ... Dial plate, 21 ... Antenna, 102 ... Ground plate, 140,140A ... Amorphous foil material as a magnetic member, 141 141A ... amorphous foil layer, 211 ... magnetic body core, 211A ... coil winding part, 211B ... lead part, 212 ... coil.

Claims (7)

An elongated magnetic core formed of a magnetic body and a coil wound around the magnetic core, and an antenna capable of receiving external wireless information, a module for housing the antenna, and a non-conductive material An electronic timepiece with a built-in antenna comprising a dial,
The magnetic core includes a coil winding portion provided at a central portion in the longitudinal direction and wound with the coil, and a pair of lead portions protruding to both end sides of the coil winding portion,
The module includes a ground plate facing the dial,
The antenna includes an antenna frame having a recess for fixing the magnetic core,
The antenna frame is fixed to the ground plane by bringing the opening end of the opening of the recess into contact with the ground plane so that the magnetic core and the ground plane are disposed through a gap,
The surface of the main plate facing the dial plate is a position that does not overlap with the coil overlapping region that overlaps the coil winding portion of the antenna in a plan view when the surface direction of the dial plate is viewed, and the pair of lead portions An electronic timepiece with a built-in antenna, characterized in that a magnetic member having a larger permeability than the dial is provided at a position overlapping at least a part of a lead overlapping region overlapping with the antenna. The electronic watch with a built-in antenna according to claim 1 ,
The timepiece with a built-in antenna, wherein the magnetic member is an amorphous foil material made of an amorphous metal. In the electronic timepiece with a built-in antenna according to claim 1 or 2 ,
The electronic member built-in antenna timepiece, wherein the magnetic member is formed in an area larger than the lead overlapping region in the plan view. The electronic timepiece with a built-in antenna according to any one of claims 1 to 3 ,
The module includes a ground plane for fixing the antenna,
The electronic timepiece with built-in antenna, wherein the magnetic member is attached and fixed to a surface of the base plate corresponding to the dial plate via an adhesive layer. In the electronic timepiece with a built-in antenna according to any one of claims 1 to 4 ,
An electronic timepiece with a built-in antenna, wherein a plurality of the magnetic members are provided. The electronic watch with a built-in antenna according to claim 1 ,
The base plate includes a communication hole that communicates a lead facing surface facing the lead portion and a dial facing surface facing the dial at least partially facing the lead portion,
The magnetic member is formed in an area larger than the lead overlap region on the dial-facing surface of the base plate, and passes through the communication hole, a magnetism collecting portion provided to cover the communication hole, and And a magnetic field output unit formed so as to protrude from a surface of the magnetic flux collecting unit facing the antenna toward the lead unit. In the electronic timepiece with a built-in antenna according to any one of claims 1 to 6 ,
The module is provided on a ground plate on which the antenna is disposed, and at least one date wheel that is provided on a surface of the ground plate facing the dial and displays a date from a date display window provided on the dial. With
The electronic timepiece with a built-in antenna, wherein the magnetic member is provided at a position between the base plate and the dial so as not to overlap the date wheel.

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