JP2007107891A - Radio controlled watch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio controlled watch capable of compensate the tuning deviation of a receiving antenna even the environment of the receiving antenna is fluctuated. <P>SOLUTION: The radio controlled watch 1 comprises: the external packaging 2 composed of components 10, 14 and 17 of non magnetic metal; the standard radio wave receiving antenna 40 arranged in the external packaging 2; the receiving circuit 63 forming a resonance circuit to the standard radio wave JJY cooperating with the receiving antenna 40; and the magnetic material 50 for correcting the inductance arranged at the position for correction proximity to the receiving antenna 40 in the external package 2 for correcting the inductance of the receiving antenna 40 in the external package 2 so that the standard radio wave receiving antenna 40 might resonance to the standard radio wave JJY by cooperating with the resonance part of the receiving circuit 63. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radio-controlled timepiece or radio-controlled timepiece, and more particularly to a radio-controlled timepiece suitable for use as a portable or small-sized timepiece such as a wristwatch.

  In a radio timepiece that receives a standard radio wave including time information and corrects the time based on the time information of the standard radio wave, a reception system including a receiving antenna basically has a long wave of a standard radio wave (for example, a frequency of 40 kHz or (60 kHz radio wave).

  In a radio timepiece with a metal watch case, even if the receiving system is formed to be tuned to a standard radio wave in a single state outside the case, if the receiving system is accommodated in the metal case, the magnetic core Since the inductance component of the receiving antenna in the form of an attached coil changes, a tuning shift (a shift from the resonance state) occurs.

  In order to compensate for this deviation, the capacitance is typically adjusted. The adjustment of the capacitance is performed by adding about 2 to 3 capacitors in parallel to the receiving antenna. However, in that case, since it is necessary to apply heat to connect the capacitor, there is a possibility that the plastic material part may be deformed or the part may be soiled to damage the part.

  On the other hand, as a method of compensating for the tuning deviation, it is also known to adjust the inductance by changing the winding length of the coil (the drawing position of the coil from the winding). However, it is not practical to apply this method to a relatively small timepiece.

  Not only when the watch case is made of non-magnetic metal but also when other exterior parts such as the back cover and dial are made of non-magnetic metal, the above-described synchronization shift occurs to some extent.

  When the receiving system is housed in the metal case, the sensitivity of the receiving system is minimized by eddy current loss caused by the magnetic flux passing through the magnetic core of the receiving antenna interlinking with the inner surface of the metal case. Therefore, it has been proposed to arrange a magnetic material around the receiving antenna (Patent Document 1).

However, this proposal is intended to increase the reception sensitivity by minimizing the loss, and does not attempt to compensate for the tuning deviation.
JP 2005-101708 A

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide a radio-controlled timepiece that can compensate for the tuning deviation even if the installation environment of the receiving antenna changes.

  In order to achieve the above object, the radio-controlled timepiece of the present invention is equipped with an exterior provided with a non-magnetic metal part, a standard radio wave receiving antenna disposed in the exterior, and a standard in cooperation with the receiving antenna. A receiving circuit that forms a resonance circuit for radio waves, and the inductance of the receiving antenna in the exterior is corrected so that the standard radio wave receiving antenna resonates with respect to the standard radio wave in cooperation with a resonance portion of the receiving circuit. Preferably, the magnetic material body for inductance correction is disposed in a correction position close to the receiving antenna in the exterior.

  In the radio-controlled timepiece according to the present invention, the exterior includes a non-magnetic metal part. Therefore, when the standard radio wave receiving antenna is disposed inside the exterior, the antenna is compared with the case where the antenna is outside the exterior. The inductance (self-inductance) changes (decreases). Therefore, for example, even if the receiving antenna is tuned with respect to the standard radio wave in a state where the receiving antenna is outside the exterior, if the receiving antenna is accommodated in the exterior, a tuning deviation occurs. However, in the radio timepiece of the present invention, “the reception of the standard radio wave reception antenna within the exterior is performed in order to correct the inductance component of the reception antenna so as to resonate with the standard radio wave in cooperation with the resonance part of the reception circuit. Since the “inductance correcting magnetic material body disposed at the correcting position close to the antenna” is provided, the receiving system including the receiving antenna can be tuned to the standard radio wave in the normal use state.

  That is, when the magnetic material for correction is arranged close to the receiving antenna, the three-dimensional shape of the magnetic material body, the relative position (distance and orientation) with respect to the receiving antenna, and the material (magnetic permeability) of the receiving antenna The magnetic resistance of the magnetic loop of the magnetic flux passing through the magnetic core decreases, and the inductance (component) of the receiving antenna increases accordingly. As a result, the resonant frequency of the resonant circuit including the receiving antenna is lowered. Therefore, by arranging the magnetic material body of a specific material and a specific shape at a specific relative position with respect to the receiving antenna so that the resonance frequency matches the frequency of the long wave of the standard radio wave, the tuning deviation can be compensated. Of course, the larger the magnetic material for correction is closer to both ends of the receiving antenna, and the higher the magnetic permeability of the magnetic material is, the greater the increase in inductance (component) of the receiving antenna. Here, “the inductance of the receiving antenna” or “the inductance component of the receiving antenna” refers to an effective self-inductance when the influence of the surroundings is expressed by an equivalent circuit attributed to the coil portion of the receiving antenna.

  In addition, the environment of the exterior in which the receiving antenna is disposed is usually different for each model of the radio timepiece. That is, usually, the main part of the watch including the radio wave correction function part made up of the receiving antenna and the receiving circuit (in this specification, the whole is referred to as “movement”) with a different exterior (that is, the watch case, the back cover and the character). Various models of timepiece products can be made by incorporating them into the area surrounded by a plate or the like. Therefore, the deviation of the inductance that occurs when the receiving antenna is arranged at a predetermined position in the exterior (the degree of reduction) also varies from model to model. In the radio-controlled timepiece of the present invention, the inductance of the receiving antenna can be increased by disposing the inductance correcting magnetic material at a position close to the receiving antenna. By changing the relative position with respect to (allowing different relative positions), the inductance of the receiving antenna can be increased to different degrees. Therefore, for example, even when the same movement is incorporated in different exteriors, variations (decreases) in inductance due to incorporation in the exterior are compensated for by arranging magnetic material bodies for inductance correction at different correction positions. Thus, it can be tuned (resonated) with respect to the standard radio wave.

  If desired, in the radio timepiece of the present invention, the receiving antenna is formed so that the inductance is already deviated from the tuning condition in a single state in which the receiving antenna is outside the exterior in consideration of the exterior environment to some extent. May be.

  Here, since the inductance of the receiving antenna also changes when the size and shape of the magnetic material body for inductance correction change, typically, the magnetic material for inductance correction has a size and shape that can surely correct the inductance. The body is preformed. Once the size and shape of the magnetic material for inductance correction are selected, the size and shape are typically maintained as they are, and the effective inductance is adjusted by changing the relative position with respect to the receiving antenna. Is done. In a specific radio timepiece with a specific exterior (watch case, back cover, dial, etc.), it is expected that the deviation of inductance is substantially the same. The magnetic material body is disposed at substantially the same position with respect to the receiving antenna. However, if desired, the magnetic material for inductance correction may be disposed in the exterior so that the position of the magnetic material for inductance correction can be adjusted with respect to the receiving antenna.

  The “correction position” that gives the tuning can be different if the three-dimensional size and the three-dimensional shape of the magnetic material for inductance correction are different. When the three-dimensional shape is changed, naturally, the occupied area in the interior of the watch case constituting the exterior is changed, which is accompanied by a change of the correction position in a broad sense. The correction position can also be changed by changing the material of the magnetic material for inductance correction (becomes a material with different magnetic permeability). Depending on the size of the inductance to be adjusted and the size and shape of the receiving antenna, instead of using the magnetic material body for inductance correction made of the same shape and the same material, the magnetic material body for inductance correction of different size, shape and material May be used to correct the inductance.

  In the radio timepiece of the present invention, the magnetic material body is naturally made of a soft magnetic material having a high magnetic permeability. On the other hand, the component part of the exterior is “made of non-magnetic metal” means that at least a part of the exterior part or at least a part of the exterior part is made of a non-magnetic metal. Say. That is, typically, at least one of a watch case, a back cover, and a dial plate, which are main components (exterior components) constituting the exterior, is made of nonmagnetic metal, or at least a part of the exterior components. For example, a part of the watch case or a part of the dial is made of a nonmagnetic metal. “Nonmagnetic metal” includes nonmagnetic alloys.

  In the radio timepiece of the present invention, the magnetic material body is typically disposed at a position shifted in the thickness direction of the timepiece with respect to the receiving antenna in the timepiece case.

  In this case, the magnetic material body has a desired shape spread in a plane perpendicular to the thickness direction, and the effective value of the inductance can be changed by adjusting the position of the magnetic material body along the plane. Here, the adjustment of the position typically means being left at a position adjusted (selected) in advance. However, the position may be adjustable (displaceable). Although the thickness of the magnetic material body may vary depending on the position in the plane perpendicular to the thickness direction, the magnetic material body typically has a flat or thin plate shape having a certain thickness. (Thin film shape). In this case, when viewed in the thickness direction, the magnetic material body may take a position that overlaps the receiving antenna as a whole, a position that at least partially overlaps, or a position that does not overlap at all. When the planar shape of the receiving antenna is constant, the inductance of the receiving antenna varies depending on the degree of overlap or proximity of the magnetic material body to the receiving antenna (particularly the degree of overlap or proximity of both ends of the receiving antenna where magnetic flux enters and exits). To do. Of course, it also depends on the thickness of the magnetic material body. Therefore, taking these into account, for example, every time the model changes, the inductance of the receiving antenna when the relative position of the magnetic material body with respect to the receiving antenna is variously measured is measured in advance to satisfy the tuning (resonance) condition. The position of the magnetic material body is determined in advance, the determined position is selected as the correction position, and the magnetic material body is disposed at the correction position.

  Instead of the magnetic material body being disposed in the case at a position shifted in the watch thickness direction with respect to the receiving antenna, if desired, the magnetic material body is in the same plane perpendicular to the watch thickness direction. It may be arranged at a position away from the receiving antenna.

  In the radio timepiece of the present invention, typically, the receiving antenna is a rod-shaped receiving antenna disposed at a position shifted in the thickness direction of the watch with respect to the magnetic material body, and the magnetic material body is arranged in the thickness direction of the watch. The correction position is selected depending on the degree of overlapping with the rod-shaped receiving antenna as viewed or the distance from the rod-shaped receiving antenna.

  In this case, the inductance can be changed greatly with the occupied area kept to a minimum, and tuning can be reliably performed. Here, when the inner peripheral surface of the watch case is circular (cylindrical), the rod-shaped antenna is typically curved in an arc shape. However, if desired, it may extend linearly. Further, if desired, the receiving antenna may have a planar shape instead of a rod shape.

  In the radio timepiece of the present invention, typically, when viewed in the thickness direction, the degree to which the magnetic material body overlaps or separates from the rod-shaped receiving antenna is perpendicular to the thickness direction. It is selected by translating in one direction in the plane. In that case, the positioning of the magnetic material body is relatively easy.

  In the radio timepiece of the present invention, typically, when viewed in the thickness direction, the degree to which the magnetic material body overlaps or separates from the rod-shaped receiving antenna is perpendicular to the thickness direction. It is selected by rotating around a rotation center axis. In this case, when the watch case is circular or the like, the position of the magnetic material body can be easily adjusted because there is little possibility that other watch parts are in the way.

  In the radio-controlled timepiece according to the present invention, as described above, the degree to which the magnetic material body overlaps the rod-shaped receiving antenna or the distance from the rod-shaped receiving antenna when viewed in the thickness direction is perpendicular to the thickness direction. For example, by selecting by translation in one direction in the plane, or by rotating the magnetic material body around a rotation center axis perpendicular to the thickness direction, and for example, When incorporating the same movement into different exteriors, if the inductance change caused by the nonmagnetic metal parts of the exterior is significantly different from the other models, instead of changing the position of the magnetic material body (correction position) significantly For example, by changing the size and shape (one or both of the planar shape and thickness) of the magnetic material body and the type of the magnetic material, the inductance increase by the magnetic material body is increased. By changing the degree of substantially the same location with respect to the case and receiving antennas may be a magnetic material body (correction position) it can be placed.

  In the radio timepiece of the present invention, typically, the magnetic material body has a disk shape or a semicircular plate shape. In that case, the arrangement of the magnetic material body is easy, or the inductance is easily changed due to the change in the relative position between the magnetic material body and the receiving antenna, and the magnetic material body is easily formed. However, when the magnetic material body is plate-shaped (or layered), the planar shape of the magnetic material body may be any shape other than a circle or a semicircle.

  In the radio timepiece according to one embodiment of the present invention, the magnetic material body is disposed on the inner surface of the back cover. In that case, the arrangement of the magnetic material body and the change of the arrangement position can be easily performed.

  In the radio timepiece of one embodiment of the present invention, the magnetic material body is disposed on the back side of the dial. In that case, it is easy to use the back cover for a buzzer and other functions.

  When the magnetic material body is made of a thin film such as a thin plate or a thin layer, the magnetic material body may be fixed to the inner surface or the back surface of a support such as a back cover or a dial plate by being attached, It may be formed by means.

  The radio timepiece according to the embodiment of the present invention is configured such that the magnetic material body is disposed in the case so that the position of the magnetic material body can be adjusted. In that case, tuning adjustments can be made on an individual basis.

    The radio timepiece of the present invention is typically in the form of a portable or small radio timepiece such as a wristwatch. However, if desired, it may be incorporated as a part of another electronic device that enables time display, or instead, a function other than the clock function may be incorporated in the timepiece.

  Next, some preferred embodiments of the present invention will be described based on preferred examples shown in the accompanying drawings.

  As shown in FIGS. 1 and 2, the radio timepiece 1 has a circular or annular nonmagnetic metal timepiece case 10. In the thin disk-like or low columnar (cylindrical) chamber 11 of the metal case 10, the dial 14 and the dial 14 are held in a state of being locked to the annular protrusion 13 protruding from the inner peripheral surface 12 of the case 10. A ground plate 15 is provided. The chamber 11 of the case 10 is closed by a watch glass 16 fitted in the opening 10 a of the case 10 and a back lid 17 screwed into the opposite opening 10 b of the case 10. In this example, the dial plate 14 and the back cover 17 are made of nonmagnetic metal, and the base plate 15 is made of resin. In the central portion of the chamber 11, a watch wheel train 20 is disposed between the base plate 15 and the resin train wheel bridge 18 facing the base plate 15. The watch wheel train 20 may be made of nonmagnetic metal or resin. The timepiece wheel train 20 is a minute wheel 21 that is rotated around the central axis B through an intermediate train wheel by a rotor 31 of a motor 30 that is disposed at an intermediate portion between the central portion and the peripheral portion of the chamber 11. And the hour wheel 22 is included. The true or shaft of the minute wheel 21 and the hour wheel 22 protrudes through the dial plate 14, and a minute hand 23 and an hour hand 24 are attached to the protruding ends. Although omitted here for simplification of the drawing, a second wheel and a second hand may be further provided. As described above, the exterior 2 includes the watch case 10, the dial 14, the back cover 17, the minute hand 23, and the hour hand 24.

  It should be noted that, in the exterior 2, all of the main exterior parts such as the watch case 10, the dial 14 and the back cover 17 are made of nonmagnetic metal, and any one of the watch case 10, the dial 14 and the back cover 17 is used. One or two may be made of a non-magnetic metal. Further, for example, only a part of the watch case 10 may be made of a nonmagnetic metal and the other part may be made of a resin or other nonmagnetic nonconductive material.

  An arc-shaped receiving antenna 40 is disposed in the chamber 11 at a position where a gap G having a desired size is provided from the inner peripheral surface 12 of the case 10. The receiving antenna 40 includes an antenna core or magnetic core 41 made of a soft magnetic material, and a winding 42 wound around the core 41. A soft magnetic material layer or soft magnetic material 50 having a predetermined size and shape is attached to a predetermined position (correction position) Dr of a surface (inner surface) 17a facing the chamber 11 in the back cover 17. Has been. The correction position Dr is not only the distance from the receiving antenna 40 with respect to the shape of the receiving antenna 40 and the thickness direction of the watch, but also the size of the soft magnetic material body 50 (size and thickness in the extending surface) and It differs depending on the shape in the extending surface and the material of the soft magnetic material body 50. The soft magnetic material may be a non-metallic magnetic material such as ferrite, or a metallic magnetic material such as an amorphous alloy.

  Instead of the inner surface of the back cover 17, the magnetic material layer 50 is, for example, the back surface 14 a of the dial 14, that is, the side facing the base plate 15 of the dial 14 as indicated by an imaginary line 50 i in FIG. It may be arranged or formed. The magnetic material layer 50 can be provided at any other location as long as it does not interfere with the placement of other timepiece components. In some cases, the magnetic material layer 50 may not overlap the receiving antenna 40 in the thickness direction.

  A circuit block 60 is arranged along the rear cover 17 side of the train wheel bridge 18. The circuit block 60 includes a circuit board 61, a clock integrated circuit (clock IC) 62 and a reception integrated circuit (reception IC) 63 mounted on the circuit board 61, and a crystal oscillator that generates clock signals for the ICs 62 and 63. 64, 65 are included. The reception IC 63 includes a resonance portion that cooperates with the reception antenna 40 to form a tuning (resonance) circuit that tunes to a long wave (for example, one or both of 40 kHz and 60 kHz) of the standard radio wave JJY including time information. The train wheel bridge 18 and the circuit board 61 have openings and notches in the portion of the stator coil 32 of the motor 30 and the portion of the winding 42 of the receiving antenna 40. The crystal oscillator 64 for the timepiece IC 62 emits a second pulse through the frequency dividing circuit of the timepiece IC 62. The crystal oscillator 65 for the reception IC 63 generates a clock pulse for controlling acquisition of time information from the standard radio wave JJY received by the reception antenna 40.

  A button type battery 19 is disposed in a region of the chamber 11 opposite to the motor 30 and the receiving antenna 40 in the diameter direction. The circuit board 61 is also cut out in the area where the battery 19 is disposed, and a battery plus electrode 66 for applying the reference potential of the circuit block 60 to the plus terminal of the battery 19 extends from the circuit board 61.

  The receiving antenna 40 and the magnetic material layer 50 located in the chamber 11 of the metal case 10 of the exterior 2 cooperate with the resonance part of the receiving circuit of the receiving IC 63, and as shown in FIG. And a resonance circuit 70 represented by an equivalent circuit including the capacitance C is formed. Here, the inductance L is the type, size and shape of the magnetic material of the core 41 of the receiving antenna 40, the characteristics of the receiving antenna 40 such as the number of windings 42, the metal case 10 and the metal in the chamber 11 of the metal case 10. It depends not only on the arrangement of the receiving antenna 40 with respect to the dial plate 14 or the metal back lid 17 but also on the material, size and shape of the magnetic material layer 50 and the relative position of the magnetic material layer 50 with respect to the receiving antenna 40.

When the inductance L of the receiving antenna 40 is a size L ₀ (for example, about 70 mH) outside the case 10 of the exterior 2, a resonant circuit such as the circuit 70 has a curve A ₀ indicated by an imaginary line in FIG. The resonance frequency fr that shows the resonance characteristics as shown and is represented by 1 / (2π (LC) ^1/2 ) is f ₀ . On the other hand, when the receiving antenna 40 is arranged in the chamber 11 of the metal case 10 of the exterior 2, the inductance L of the receiving antenna 40 in the form of a coil with a magnetic core has a magnitude L ₀ to L ₁ (where L ₁ <L ₀ , For example, it changes (decreases) to about 50 mH. As a result, the resonance frequency fr also changes from f ₀ to f ₁ (where f ₁ > f ₀ ), and the resonance characteristics are as shown by the curve A ₁ indicated by the one-dot chain line in FIG. Here, with reference to the long-wave frequency f _s = 40 kHz of the standard radio wave JJY, taking into account the change ΔL = L ₀ −L ₁ of the inductance L when placed in the metal case 10, f ₀ <f _s and By selecting the inductance L ₀ so as to ensure f _s <f ₁ , the magnetic material layer 50 can be appropriately positioned with respect to the receiving antenna 40 (correcting position) with an appropriate material, size and shape. ) By arranging at Dr, it is possible to realize the resonance characteristic as shown by the curve A _c shown by the solid line in FIG. 4 by adjusting the inductance L = L _c giving f _c = f _s . As long as the inductance L can be adjusted by providing the magnetic material layer 50, if desired, instead of f ₀ <f _s and f _s <f ₁ , simply f ₀ = f _s. In some cases, f ₀ > f _s may be satisfied.

As described above, in the radio timepiece 1, the exterior 2 includes the watch case 10, the back cover 17, and the dial 14 as non-magnetic metal parts, so 12 and the inner surface 17a of the back cover 17 and the like, when placed in the small chamber 11 of the exterior 2, the inductance L of the antenna 40 compared to the case where the antenna 40 is outside the exterior 2. Changes (decreases). Therefore, for example, even if the receiving antenna 40 is tuned with respect to the standard radio wave JJY in the state of being outside the exterior 2, if the receiving antenna 40 is accommodated in the exterior 2, a tuning deviation occurs as it is. . However, in the radio-controlled timepiece 1, the inductance correcting magnetic material body 50 having a specific size and shape is disposed in the correction position Dr close to the receiving antenna 40 in the exterior 2. Since L is corrected by the magnetic material body 50, the standard radio wave receiving antenna 40 connected to the resonance portion of the receiving circuit of the receiving IC 63 can be tuned to the long wave of the frequency f _s of the standard radio wave JJY. As a result, in the radio timepiece 1, the size of the timepiece 1 is minimized, and the standard radio wave receiving antenna 40 is disposed in the state of being close to the inner peripheral surface 12 of the timepiece case 10, the inner surface 17 a of the back cover 17, and the like. However, it is possible to compensate for the adverse effects caused by the nonmagnetic metal material portion of the exterior 2 and to increase the reception sensitivity of the standard radio wave. Therefore, in this radio timepiece 1, not only it is possible to give a high-class feeling by increasing the number of metal exterior parts, but it is not necessary to add a tuning capacitor, so that the resin material of the movement is damaged by heat. The fear can be minimized.

  Next, two test examples in which the magnetic material layer 50 is formed of semicircular magnetic material bodies 51 and 52 will be described with reference to FIGS. 5 and 6, and the magnetic material layer 50 may be a circular magnetic material body. A test example consisting of 53 will be described with reference to FIG.

Test example 1
As shown in the lower part of FIG. 5, the magnetic material layer 50 is in the form of a semicircular thin plate 51 having approximately half the size of a circular region facing the chamber 11 in the back cover 17. The thin plate 51 is made of a Co-based soft magnetic amorphous alloy. In Test Example 1, the semicircular magnetic material body 51 is placed around the center B of the circle of the chamber 11 with respect to the receiving antenna 40 disposed in the chamber 11 of the metal case 10 as shown in FIGS. , Relative rotation.

In the state indicated by T1a, the semicircular magnetic material body 51 is on the opposite side of the diametrical direction from the receiving antenna 40, and there is no portion overlapping the receiving antenna 40 when viewed along the extending direction of the central axis B. Also, it is considerably away from both ends of the core 41 of the receiving antenna 40. Therefore, the magnetic flux passing through the core 41 of the receiving antenna 40 hardly passes through the magnetic material layer 51. As a result, the inductance L _t1a of the receiving antenna 40 in the state T1a is substantially the same as the inductance L _{1 in the} absence of the magnetic material body 51, and the resonance frequency f _t1a is also substantially the same as the resonance frequency f ₁ .

On the other hand, in the state indicated by T1b, the magnetic material body 51 takes a position that is relatively rotated by 90 degrees as compared with the case of the state T1a, and when viewed along the extending direction of the central axis B, the receiving antenna A magnetic material body 51 is overlapped with a half portion of 40. That is, the magnetic material body 51 overlaps with one end portion of the core 41 of the receiving antenna 40 and does not overlap with the other end portion when viewed in the extending direction of the central axis B. Accordingly, the magnetic material body 51 provides a portion near half of the magnetic path of the magnetic flux passing through the core 41 of the receiving antenna 40. As a result, as can be seen from the points on the graph of FIG. 5, the inductance L _t1b of the receiving antenna 40 in the state T1b is larger than the inductances L ₁ and L _t1a . Therefore, the resonance frequency f _t1b of the reception system including the reception antenna 40 in the state T1b is smaller than the resonance frequencies f ₁ and f _t1a .

Furthermore, in the state indicated by T1c, the magnetic material body 51 is in a state in which the magnetic material body 51 is further rotated by 90 degrees compared to the state T1b (a state in which the magnetic material body 51 is relatively rotated by 180 degrees compared with the case of the state T11). When taken along the extending direction of the central axis B, the magnetic material body 51 completely overlaps the receiving antenna 40. That is, the magnetic material body 51 overlaps both ends of the core 41 of the receiving antenna 40 when viewed in the extending direction of the central axis B. Therefore, most of the magnetic path of the magnetic flux passing through the core 41 of the receiving antenna 40 is provided by the magnetic material body 51. As a result, as can be seen from the points on the graph of FIG. 5, the inductance L _t1c of the receiving antenna 40 in the state T1c has a value larger than the inductances L ₁ , L _t1a and L _t1b . Therefore, the resonance frequency f _t1c of the reception system including the reception antenna 40 in the state T1c is further smaller than the resonance frequencies f ₁ , f _t1a and f _t1b .

The dependence of the inductance L _t1 and the resonance frequency f _t1 on the relative angle between the magnetic material body 51 and the receiving antenna 40 is given by curves L _t1 and f _t1 in the graph of FIG. Accordingly, in FIG. 5, the direction (relative angle) indicated by the symbol D _t1 that gives a position that matches fr = fc = 40 kHz in FIG. 5 is set so that the resonance (tuning) frequency fr matches the long wave frequency fc of the standard radio wave JJY. Then, the direction (relative angle) of the magnetic material body 51 with respect to the receiving antenna 40 is selected, and the semicircular magnetic material body 51 is pasted on the surface 17a of the back cover 17 so that the semicircular magnetic material body 51 faces in this direction. Etc. are formed. Accordingly, the timepiece 1 manufactured under substantially the same conditions (that is, a timepiece in which substantially the same movement is accommodated in the substantially identical metal case 10 or other substantially identical exterior). For example, the receiving antenna 40 can be incorporated as a component of the timepiece 1 so as to satisfy the resonance (tuning) condition.

  In the case where the rotational position of the back cover 17 is configured to be adjustable, even if there is a variation in parts due to some cause and a slight difference may occur between individuals or lots, the back cover 17 By slightly changing the rotational position of the watch 1, the timepiece 1 can be assembled to satisfy the tuning condition.

Even when the magnetic material body 51 is rotated in the opposite direction from the state T1a to the state T1b, a curve having characteristics substantially similar to the rotation characteristic curves L _t1 and f _t1 can be obtained. You may select / determine the direction. However, of course, if there are other metal parts or magnetic parts in the case 10 that are relatively close to the receiving antenna 40, it depends on their arrangement, so the characteristics are slightly different. Also, the magnitude of the rotation angle can be somewhat different.

  Even when another magnetic material is used as the magnetic material of the magnetic material body 51 instead of the Co-based amorphous alloy, the above description is qualitatively applied. Further, even when the planar shape and thickness of the magnetic material body 51 are changed to some extent, the above description is qualitatively applicable as it is.

Test example 2
As shown in the lower part of FIG. 6, the magnetic material layer 50 is formed of a semicircular thin plate 52 having a half size of a circle smaller than a circular region facing the chamber 11 in the back cover 17. The magnetic material of the thin plate 52 is the same as the magnetic material of the thin plate 51 of Test Example 1. In Test Example 2, as shown in FIGS. 1 and 2, the position or state T2a far away from the receiving antenna 40 and the central axis B with respect to the receiving antenna 40 disposed in the chamber 11 of the metal case 10 are used. The thin plate 52 was moved in parallel with the state T2f overlapping the receiving antenna 40 as viewed in the extending direction. The intermediate translation position or state is as shown by T2b, T2c, T2d, and T2e in FIG. 6, and the translation amounts are the same in T2a → T2b, T2b → T2c, and T2c → T2d, T2d → T2e and T2e → T2f were twice as large.

The closer the magnetic material body 52 is to the receiving antenna 40 (particularly to both ends of the core 41 of the receiving antenna 40), the inductance L _t2 of the receiving antenna 40 increases and the resonance frequency f _t2 decreases. The characteristic curves L _t2 and f _t2 of the inductance L and the resonance frequency fr depending on the translation position are as shown in FIG. The horizontal axis of the graph represents the six states T2a, T2b, T2c, T2d, T2e, and T2f at equal intervals, but the translation amount of the magnetic material 52 is not constant between adjacent states as described above. Thus, although the direction of the trend of the characteristic curves L _t2, f _t2 (slope) is significant, as the magnitude of the slope of the change in the characteristic curve L _t2, f _t2 should be evaluated in view of the above translation amount It is.

That is, since the core 41 of the receiving antenna 40 and the magnetic material body 52 can be relatively close to each other in the thickness direction of the timepiece 1, when the overlap begins to occur toward the state T2e beyond the state T2d, the translation amount becomes two. The inductance L _t2 increases abruptly even when considering that it is twice, and the magnetic material body 52 overlaps with a corresponding portion on the inner peripheral side of the end portion of the core 41 and the magnetic flux passing through the end portion of the core 41 is actually magnetic. As it passes through the material body 52, it can be seen that the inductance L _t2 tends to hardly change even if the degree of overlap further advances.

Also in this case, in FIG. 6, the translation position indicated by reference symbol D _t2 is given to give a position that matches fr = fc = 40 kHz so that the resonance (tuning) frequency fr matches the long wave frequency fc of the standard radio wave JJY. The magnetic material body 52 is selected as the translation position of the magnetic material body 52, and the magnetic material body 52 is formed on the surface 17a of the back cover 17 so that the magnetic material body 52 is positioned at the translation position. As a result, if the timepiece 1 is manufactured under substantially the same conditions, even if the receiving antenna 40 has an inductance that is originally deviated from the resonance (tuning) condition, the receiving antenna 40 is not affected by the resonance (tuning) condition. Can be incorporated into the watch 1 to satisfy

Test example 3
A circular magnetic material layer 53 having a diameter of about 60% of the diameter of the metal disk 14f is formed as a magnetic material layer 50 on the back surface of the nonmagnetic metal disk 14f having the same size as the dial 14. The receiving antenna 40 was moved on the metal disc 14f, and changes in the inductance and the resonance frequency of the receiving antenna 40 were measured. In this example, the magnetic material layer 53 is made of hardened ferrite powder.

  More specifically, as shown in the lower part of FIG. 7, on the nonmagnetic metal disk 14f, the position or the state T3a farthest from the circular magnetic material layer 53 and the extending direction of the central axis of the metal disk 14f. Between the state T3f that overlaps the magnetic material layer 53 as viewed along the line, the receiving antenna 40 is rotated while being close to the extending surface of the metal disk 14f so as to gradually overlap the magnetic material layer 43. Moved. Intermediate movement positions or states are as indicated by T3b, T3c, T3d, and T3e in FIG. In the case of this example, in an intermediate movement position, the degree to which one end and the other end of the end portions of the core 41 of the receiving antenna 40 are close to the magnetic material layer 53 is different from that of the test example. Different from 2.

As the receiving antenna 40 (particularly the end of the core 41 of the receiving antenna 40) is closer to the magnetic material layer 53, the inductance L _t3 of the receiving antenna 40 increases and the resonance frequency _ft3 decreases. The characteristic curves L _t3 and f _t3 of the inductance L and the resonance frequency fr depending on are as shown in FIG.

Also in this case, the horizontal axis of the graph represents the six states T3a, T3b, T3c, T3d, T3e, and T3f at equal intervals, but the direction of movement (relative displacement) of the receiving antenna 40 with respect to the magnetic material layer 53. since and size are not the same between adjacent states, another trend (slope) characteristic curve L _t3, f _t3, the size of the change in slope of the characteristic curve should be consulted for trend . That is, since the core 41 of the receiving antenna 40 and the magnetic material layer 53 can be relatively close to each other in the thickness direction of the metal disc 14f (thickness direction of the timepiece 1), the state goes beyond the state T3d toward the state T3e. When the overlap begins to occur, not only one end portion of the core 41 of the receiving antenna 40 but also the other end portion is close to the magnetic material layer 53, so that the inductance L _t3 rapidly increases and the other end portion of the core 41 is increased. It can be seen that there is a tendency that the inductance L _t3 continues to increase until the magnetic material layer 52 overlaps the end.

In the timepiece 1, when the timepiece case 10 is not made of metal but is made of a non-conductive resin and only the influence of the back cover 17 in the form of the metal disk 14f needs to be considered, the resonance frequency fr is a standard radio wave. In FIG. 7, the relative displacement position indicated by reference symbol D _t3 that gives a position that matches fr = fc = 40 kHz is selected as the relative displacement position of the magnetic material layer 53 so as to match the frequency fc of the long wave of JJY. to the relative displacement positions D _t3, as the magnetic material layer 53 is positioned, it will form the magnetic material layer 53 on the inner surface 17a of the back cover 17 in the form of a metal disk 14f (see FIG. 2). As a result, if the timepiece 1 is manufactured under substantially the same conditions, even if the receiving antenna 40 has an inductance that is originally deviated from the resonance (tuning) condition, the receiving antenna 40 is not affected by the resonance (tuning) condition. Can be incorporated into the watch 1 to satisfy When this test example 3 is applied to the dial 14, the ground plate 15 is interposed between the dial 14 and the receiving antenna 40, and the dial 14 and the receiving antenna 40 in the thickness direction of the timepiece 1 are connected. Considering that the relative position is slightly different from the relative position of Test Example 3, strictly speaking, it is necessary to determine the characteristic curve f _t3 by performing a similar test in consideration of the thickness of the ground plane 15.

  The magnetic material body 50 typically occupies a continuous continuous area, but may be dispersed in a plurality of areas apart from each other if desired.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory plan view of a radio timepiece according to a preferred embodiment of the present invention (a view from the back cover side in a state where the back cover is removed); II-II sectional view explanatory drawing of the radio timepiece of FIG. FIG. 2 is an equivalent circuit diagram schematically showing a resonance (tuning) circuit of a receiving system including the receiving antenna of the radio timepiece of FIG. 1. The typical graph for demonstrating the resonance characteristic depending on the arrangement environment of the receiving antenna used for the radio timepiece of FIG. The graph which showed one test example of the change of the inductance and resonant frequency of a receiving antenna when the magnetic material body is rotated relative to the receiving antenna in the radio timepiece of FIG. FIG. 2 is a graph showing a test example of changes in the inductance and resonance frequency of the receiving antenna when the magnetic material body is relatively translated with respect to the receiving antenna in the radio timepiece of FIG. The graph which showed one test example of the change of the inductance and resonant frequency of a receiving antenna when the position and direction of a receiving antenna were changed on a nonmagnetic metal plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio clock 2 Exterior 10 Nonmagnetic metal watch case 11 Chamber 14 Nonmagnetic metal dial 15 Resin base plate 16 Watch glass 17 Nonmagnetic metal back cover 18 Resin wheel train 19 Battery 20 Clock train 30 Motor 40 Receiving Antenna 41 Magnetic Core 42 Winding 50, 51, 52, 53 Soft Magnetic Material Body 60 Circuit Block 61 Circuit Board 62, 63 Integrated Circuit 64, 65 Oscillator 70 Resonant Circuits A ₀ , A ₁ , _Ac Resonance Characteristic Curve B central axis _{Dr, D t1, D t2,} D t3 correction position f _0, f _1, f _r the resonant frequency f _c standard radio frequency f _t1, f _t2, curve representing the variation of f _t3 resonant frequency L, L ₀ , L ₁ the inductance L _t1, L _t2, L curve T1a indicating the change of _t3 inductance, T1b, state corresponding to the relative rotational positions of the magnetic material body with respect to the receiving antenna in T1c metal case T2a, T2b T2c, T2d, T2e, T2f States corresponding to the relative translation position of the magnetic material body with respect to the receiving antenna in the metal case T3a, T3b, T3c, T3d, T3e, T3f Relative of the receiving antenna to the magnetic material body on the metal dial State according to displacement position

Claims (10)

An exterior with parts made of non-magnetic metal,
A standard radio wave receiving antenna disposed in the exterior;
A receiving circuit that forms a resonant circuit for a standard radio wave in cooperation with the receiving antenna;
In order to correct the inductance of the reception antenna in the exterior so that the standard radio wave reception antenna resonates with the standard radio wave in cooperation with the resonance portion of the reception circuit, A radio-controlled timepiece having an inductance correction magnetic material disposed at a close correction position.   The radio timepiece according to claim 1, wherein the nonmagnetic metal part of the exterior is at least a part of a watch case, a back cover, and a dial. The radio timepiece according to claim 1 or 2, wherein the magnetic material body is in a position shifted in a thickness direction of the timepiece with respect to the receiving antenna in a timepiece case constituting the exterior.   The receiving antenna is a rod-shaped receiving antenna, and the correction position is selected depending on the degree to which the magnetic material body overlaps or separates from the rod-shaped receiving antenna when viewed in the thickness direction of the watch. The radio timepiece according to claim 3.   The degree to which the magnetic material body overlaps or separates from the rod-shaped receiving antenna as viewed in the thickness direction translates the magnetic material body in one direction within a plane perpendicular to the thickness direction. The radio timepiece according to claim 4, which is selected by being moved.   The degree to which the magnetic material body overlaps or separates from the rod-shaped receiving antenna as viewed in the thickness direction is determined by moving the magnetic material body around the rotation center axis perpendicular to the thickness direction. The radio timepiece according to claim 4, wherein the radio timepiece is selected by rotating.   The radio timepiece according to any one of claims 1 to 6, wherein the magnetic material body has a disk shape or a semicircular plate shape.   The radio timepiece according to any one of claims 2 to 7, wherein the magnetic material body is disposed on an inner surface of the back cover.   The radio timepiece according to any one of claims 2 to 7, wherein the magnetic material body is disposed on a back side of the dial.   The radio timepiece according to any one of claims 1 to 8, wherein the magnetic material body is arranged in the exterior so as to be adjustable in position.

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