JP6768260B2 - Electronic clock movement and electronic clock - Google Patents

Description

The present invention relates to an electronic timepiece movement and an electronic timepiece.

An electronic watch whose pointer is driven by a motor is equipped with a magnetic-resistant plate in the movement to protect the motor from an external magnetic field.
The magnetic resistance plate is generally formed so as to cover the motor from above and below in the thickness direction (see, for example, Patent Document 1). Conventionally, the magnetic resistance plate covers the motor widely to improve the magnetic resistance performance of the motor.

JP-A-2007-232680

However, simply arranging a large anti-magnetic plate has a problem that the size of the electronic timepiece itself becomes large or the thickness of the electronic timepiece itself becomes thick in order to secure the space for that amount. In the case of a functional electronic watch, it may not be possible to place a large anti-magnetic plate inside the movement.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic timepiece movement and an electronic timepiece capable of improving the magnetic resistance performance against a motor without increasing or thickening the magnetic resistance plate. And.

The first aspect of the present invention includes a motor and a magnetic-resistant plate that covers the motor, and the magnetic-resistant plate is located on the upstream side of the motor in a magnetically weakest direction of the magnetic field acting on the magnetic-resistant plate. A narrowed portion having a small cross-sectional area of the path through which the magnetic flux passes is formed, the magnetic resistance plate covers a plurality of motors, and at least one of the motors is arranged in a direction orthogonal to the longitudinal direction of the magnetic resistance plate. It is a movement of an electronic clock.
The second aspect of the present invention includes a motor and a magnetic-resistant plate that covers the motor, and the magnetic-resistant plate is located on the upstream side of the motor in the magnetically weakest direction of the magnetic field acting on the magnetic-resistant plate. A motor in which a narrowed portion having a small cross-sectional area of a path through which magnetic flux passes is formed and arranged in a direction orthogonal to the longitudinal direction of the magnetic resistance plate is a movement of an electronic clock which is a motor for driving a second hand.
A third aspect of the present invention includes a motor and a magnetic-resistant plate that covers the motor, and the magnetic-resistant plate is located on the upstream side of the motor in the magnetically weakest direction of the magnetic field acting on the magnetic-resistant plate. A narrowed portion having a small cross-sectional area of the path through which the magnetic flux passes is formed, and the narrowed portion is a movement of an electronic clock formed so that the thickness of the magnetic resistance plate is thinner than other portions.
A fourth aspect of the present invention is an electronic timepiece including the movement of the electronic timepiece of the present invention and a case for accommodating the movement.

According to the movement of the electronic timepiece and the electronic timepiece according to the present invention, it is possible to improve the magnetic resistance performance for the motor without increasing or thickening the magnetic resistance plate.

It is a partial perspective view which shows the radio wave correction timepiece which is one Embodiment of the electronic timepiece which concerns on this invention. FIG. 5 is an exploded perspective view showing a part of the movement shown in FIG. 1 in an exploded manner. It is a top view corresponding to FIG. 1 which shows the positional relationship between two magnetic resistance plates and a motor in a plan view. It is a top view which shows the simple substance of the upper magnetic resistance plate shown in FIG. It is a top view which shows the simple substance of the lower magnetic resistance plate shown in FIG. It is a figure which shows the detail of the second hand motor shown in FIG. With respect to the anti-magnetic plate shown in FIG. 4, the outer shape shown by the alternate long and short dash line without a notch, and the thickness of the portion corresponding to the notch in the anti-magnetic plate is formed thinner than the other portions. It is a figure which shows the magnetic-resistant plate, (A) is a plan view corresponding to FIG. 4, (B) is a sectional view which shows the cross section along the line AA in (A).

Hereinafter, the movement of the electronic timepiece and the embodiment of the electronic timepiece according to the present invention will be described with reference to the drawings.

<Structure of radio wave correction clock>
FIG. 1 shows a radio wave correction watch 1 which is an embodiment of an electronic watch according to the present invention, and a movement 3 represented by a solid line is virtually transmitted through a case 2 represented by a two-dot chain line from the back cover side. It is a partial perspective view showing a visible state. The upper part of FIG. 1 is the 12 o'clock direction, and the left side is the 3 o'clock direction. FIG. 2 is an exploded perspective view showing a part of the movement 3 shown in FIG. 1 in an exploded manner.

The radio wave correction watch 1 has a movement 3 housed inside a metal case 2.
The radio wave correction clock 1 has a function of receiving a radio wave and the movement 3 automatically correcting a pointer for time based on the received radio wave. Further, the radio wave correction clock 1 includes a solar cell panel and a secondary battery, and drives the movement 3 by the electric power generated by the solar cell panel.

<Structure of movement>
The movement 3 is an embodiment of the movement of an electronic timepiece according to the present invention. The movement 3 includes a main plate 5, a train wheel (not shown), a train wheel receiver 6, a circuit board 7, a circuit holding plate 8, two magnetic resistant plates 21 and 22, and an antenna 10 for receiving radio waves (FIG. 1), a second hand motor 11 which is a four-step motor, a dual minute / hour hand motor 12, a minute / hour hand motor 15, and a functional hand motor 16.
In addition to the above-described configuration, the movement 3 also includes a mechanism for manually correcting the pointer for displaying the time, an alarm buzzer, a secondary battery, and other mechanisms. Since it is not essential for the explanation of the radio wave correction clock 1, the explanation will be omitted.

The second hand motor 11 includes a coil (converter) 11a, a stator 11b, and a rotor 11c. The rotor 11c of the second hand motor 11 is connected to the train wheel that drives the second hand.
The dual minute hand motor 12 includes a coil 12a, a stator 12b and a rotor 12c. The rotor 12c of the dual minute hand motor 12 is connected to the minute hand for the lowercase plate and the train wheel that drives the hour hand.

The minute hand motor 15 includes two coils 13a and 14a, a stator 15b and a rotor 15c. The rotor 15c of the minute hand motor 15 is connected to the minute hand and the train wheel that drives the hour hand. The minute hand motor 15 includes two coils 13a and 14a in order to make the rotation speed in the forward rotation direction equal to the rotation speed in the reverse rotation direction.

That is, the minute hand and the hour hand are linked, but in order to correct the time difference, the minute hand and the hour hand are rotated in the direction of advancing the time (forward rotation direction) and the minute hand is in the direction of returning the time (reverse rotation direction). And the hour hand may be rotated. By making the rotation speed equal in the forward rotation direction and the reverse rotation direction, there is no difference in the rotation speed of the minute hand and the hour hand at the time of correction between the case where the time is advanced and the case where the time is set back and the time is corrected. Can be done.

The functional needle motor 16 includes a coil 16a, a stator 16b, and a rotor 16c. The rotor 16c of the functional needle motor 16 is connected to a train wheel that drives the functional needle for the lowercase plate. The functional needle is, for example, a guideline for instructing the amount of charge of the electric power generated by the solar cell panel and being charged in the secondary battery, a guideline for instructing the day of the week, and the like. The guideline for instructing the amount of charge and the guideline for instructing the day of the week may be independent guidelines or may be used in combination with one guideline.

The second hand motor 11, the dual minute and hour hand motor 12, the minute and hour hand motor 15, and the functional hand motor 16 are joined to the circuit board 7. The circuit board 7 controls the second hand motor 11, the dual minute and hour hand motor 12, the minute and hour hand motor 15, and the functional hand motor 16, controls the reception of radio waves and the correction of pointers based on the received radio waves, and the electric power generated by the solar panel. An electronic circuit is formed that charges the secondary battery and controls the supply of electric power from the secondary battery. The electronic circuit itself is driven by the electric power supplied from the secondary battery.

Under the control of the electronic circuit of the circuit board 7, the second hand motor 11 is driven at a frequency of once per second, the dual minute / hour hand motor 12 is driven at a frequency of once per minute, and the minute / hour hand motor 15 is driven at a frequency of 10 seconds. It is driven once, and the functional needle motor 16 is driven only when an operation for displaying a state (charge amount, day of the week, etc.) corresponding to the function is input.

Due to such drive frequency, the four motors 11, 12, 15 and 16 are driven in descending order of frequency, that is, in ascending order of coercive force, second hand motor 11, minute hand motor 15, dual minute hand motor 12, and functional hand motor. It becomes 16. The lower the coercive force, the higher the magnetic resistance is required. Therefore, the second hand motor 11, the minute and hour hand motor 15, the dual minute and hour hand motor 12, and the functional hand motor 16 have higher priorities for requiring magnetic resistance.

The train wheel is supported by being sandwiched between the main plate 5 and the train wheel receiver 6, and is rotated by the drive of any of the corresponding motors 11, 12, 15, 16 to drive the second hand, the minute hand, the hour hand, or the functional hand. ..
The circuit holding plate 8 is formed of a conductive metal plate, and a part thereof is connected to a ground (GND) line in an electronic circuit of a circuit board 7, and a other part is connected to a case 2. As a result, the circuit holding plate 8 electrically conducts the ground line of the electronic circuit to the case 2.
The antenna 10 receives a radio wave (for example, a GPS signal including time information transmitted from a GPS satellite) including time information for adjusting the time display pointer to a correct position.

FIG. 3 is a plan view corresponding to FIG. 1 showing the positional relationship between the two magnetic resistant plates 21 and 22 in the movement 3 and the motors 11, 12, 15 and 16 in a plan view. The two anti-magnetic plates 21 and 22 particularly sandwich the rotors 11c, 12c, 15c and 16c in the thickness direction of the radio wave correction watch 1 from the back cover side and from the back side of the main plate 5 so that the rotors 11c, 12c, Covers 15c and 16c. The magnetic resistant plates 21 and 22 cover the rotors 11c, 12c, 15c and 16c to suppress the influence of the external magnetic field on the rotors 11c, 12c, 15c and 16c.

FIG. 4 is a plan view showing a single unit of the upper anti-magnetic plate 21 shown in FIG. 3, and FIG. 5 is a plan view showing a single unit of the lower anti-magnetic plate 22 shown in FIG.
As shown in FIG. 4, the anti-magnetic plate 21 has a large number of escape holes 21a for preventing interference with the coil 11a of the second hand motor 11 and a large number of holes 21b for supporting the motors 11, 12, 15, and 16. Has been done. As shown in FIG. 5, the anti-magnetic plate 22 is also formed with a large number of holes 22b for supporting the motors 11, 12, 15, and 16.

FIG. 6 is a diagram showing details of the second hand motor 11 shown in FIG. As shown in FIG. 6, when the coil is not energized, the rotor 11c of the second hand motor 11 is stably stopped at a predetermined position. The stopped rotor 11c is magnetically weakest with respect to the magnetic field J in which the magnetic flux is along the direction M orthogonal to the direction L connecting the two slits 11s and 11s of the stator 11b.
Such magnetically weak orientations are also present in the other motors 12, 15 and 16, respectively.
Although the slit 11s of the stator 11b in the present embodiment is formed by voids, the stator 11b may be integrated by filling the voids with a non-magnetic material.

Here, as shown in FIG. 4, the magnetic resistance plate 21 has a narrow narrowed portion 21c (with respect to the direction M of the magnetic field J, which is magnetically weakest with respect to the second hand motor 11 due to the presence of the relief hole 21a of the coil 11a. It has another example of a stenosis). As shown in FIG. 3, the narrowed portion 21c corresponds to a narrowed portion formed around the coil 11a of the second hand motor 11.

Generally, the larger the outer shape of the anti-magnetic plate, the better the anti-magnetic performance. Therefore, as shown in FIG. 4, it is generally considered that the magnetic resistant plate 21 also adopts an outer shape without a notch 21d, for example, as shown by a two-dot chain line on the lower left side portion.
However, in the anti-magnetic plate 21 of the present embodiment, a notch 21d as shown by a solid line is formed in the lower left portion of the drawing of the anti-magnetic plate 21.

Due to this notch 21d, the portion between the magnetic field resistant plate 21 and the hole 21b is narrowed narrower than the other portions with respect to the direction M of the magnetic field J, which is magnetically weakest with respect to the second hand motor 11. It becomes part 21e. Moreover, the narrowed portion 21e is located upstream of the rotor 11c of the second hand motor 11 with respect to the direction M of the magnetic field J. Further, the narrowed portion 21e is upstream of the narrowed portion 21c with respect to the direction M of the magnetic field J.

The anti-magnetic plate 22 shown in FIG. 5 also has a notch 22d formed in a portion (see FIG. 3) that overlaps the notch 21d of the anti-magnetic plate 21 in a plan view. Further, in this magnetic resistant plate 22, the portion between the notch 22d and the hole 22b is narrower than the other portions with respect to the direction M of the magnetic field J, which is magnetically weakest with respect to the second hand motor 11. It becomes. Moreover, the narrowed portion 22e is located upstream of the rotor 11c of the second hand motor 11 with respect to the direction M of the magnetic field J.

<Action of movement>
According to the radio wave correction clock 1 and the movement 3 of the embodiment configured as described above, the second hand motor 11 having the weakest coercive force among the four step motors is magnetically as shown in FIG. When the magnetic field J in the weakest direction acts, the magnetic field J acts on the magnetic resistant plates 21 and 22 that cover the second hand motor 11 from above and below in the thickness direction of the radio wave correction clock 1 as shown in FIGS.

At this time, in the narrowed portion 21e of the magnetic resistance plate 21 formed on the upstream side in the direction of the magnetic field J with respect to the second hand motor 11, partial magnetic saturation is induced because the area (cross-sectional area) of the path through which the magnetic flux passes is small. To. As a result, the magnetic flux of the magnetic field J is distributed in a path that does not pass through the narrowed portion 21e where magnetic saturation has occurred.
As a result, the magnetic flux density at the portion of the magnetic resistance plate 21 corresponding to the second hand motor 11 on the downstream side of the narrowed portion 21e where magnetic saturation has occurred becomes smaller than that without the narrowed portion 21e.

Therefore, according to the radio wave correction watch 1 and the movement 3 of the present embodiment, the portion of the magnetic resistant plate 21 corresponding to the second hand motor 11 is used without increasing the outer size (size, thickness) of the magnetic resistant plate 21. The magnetic resistance performance of the magnetic resistance plate 21 with respect to the second hand motor 11 can be improved as compared with the magnetic resistance plate without the narrowed portion 21e.
Further, in the radio wave correction watch 1 and the movement 3 of the present embodiment, another anti-magnetic plate 22 is arranged on the other surface side of the second hand motor 11, and the anti-magnetic plate 22 is also the same as the narrowed portion 21e of the anti-magnetic plate 21. The narrowed portion 22e of the above is formed. Therefore, the magnetic resistance performance of the magnetic resistance plate 22 with respect to the second hand motor 11 is further improved.

According to the radio wave correction clock 1 and the movement 3 of the present embodiment, the narrowed portions 21e and 22e are formed on the magnetically resistant plates 21 and 22 corresponding to the magnetic field J in the direction in which the second hand motor 11 is magnetically weakest. Therefore, the magnetic resistance of the second hand motor 11 in the weakest direction is improved, and the overall magnetic resistance is raised.
However, the constricted portion in the present invention is not limited to that of this embodiment. That is, the narrowed portions 21e and 22e in the embodiment do not correspond to the magnetic field J in the direction that is magnetically weakest with respect to the second hand motor 11, but are attached to the magnetic resistant plates 21 and 22 of the radio wave correction clock 1 from the second hand motor 11. May be formed in any part on the upstream side. In this case, the magnetic resistance performance of the magnetic resistance plates 21 and 22 with respect to the second hand motor 11 can be improved with respect to the magnetic field in the direction corresponding to the narrowed portions 21e and 22e.

Further, in the radio wave correction clock 1 and the movement 3 of the present embodiment, since the magnetic resistance plate 21 is formed with a relief hole 21a for avoiding interference with the coil 11a of the second hand motor 11, the coil 11a of the second hand motor 11 is formed. A narrowed portion 21c is formed in the periphery in which the width of the portion between the escape hole 21a and the outer shape is narrower than the width of the other portion in the direction of the magnetic field J.
Then, in such a narrowed portion 21c, magnetic saturation is likely to occur due to the acting magnetic field J. When magnetic saturation occurs around the coil 11a, the anti-magnetic plate 21 does not work effectively around the coil 11a, which may adversely affect the rotor 11c of the second hand motor 11.

However, in the magnetic resistant plate 21 of the present embodiment, the narrowed portion 21e is formed on the upstream side of the second hand motor 11 and on the upstream side of the narrowed portion 21c around the coil 11a with respect to the direction M of the magnetic field J. ing. As a result, when the magnetic field J acts on the magnetic resistance plate 21, magnetic saturation occurs in the narrowed portion 21e, so that the magnetic flux density decreases in the narrowed portion 21c on the downstream side.
Therefore, according to the radio wave correction watch 1 and the movement 3 of the present embodiment, magnetic saturation is less likely to occur in the narrowed portion 21c on the downstream side as compared with the one without the narrowed portion 21e. As a result, the anti-magnetic plate 21 functions effectively around the coil 11a, and it is possible to prevent an adverse effect due to the presence of the narrowed portion 21c around the rotor 11c of the second hand motor 11.

The electronic clock and movement according to the present invention are not limited to this form. That is, the electronic clock and the movement according to the present invention may not have another constricted portion formed around the coil of the motor, and even in this case, the constricted portion on the upstream side with respect to the direction of the magnetic field from the motor. Can induce magnetic saturation in the stenosis due to the formation of.
As a result, the magnetic flux of the magnetic field acting on the magnetic resistance plate is dispersed in other paths avoiding the narrowed portion when magnetic saturation is induced in the narrowed portion, and the dispersed magnetic flux corresponds to the position of the motor. It passes through the part of the magnetic resistance plate. As a result, the magnetic resistance performance of the magnetic resistance plate at the position of the motor can be improved without increasing the size of the magnetic resistance plate.

<Modification example of configuration>
The narrowed portion 21e in the present embodiment is formed as a narrow portion by a notch 21d cut inward from the outer peripheral edge, but the narrowed portion in the present invention is limited to the embodiment of this embodiment. It is not something that is done. That is, for example, it is a constricted portion in which the width from the removed portion to the contour of the outer shape is narrowed by removing the contour of the outer shape by forming a hole in the inner portion without changing the contour of the outer shape. May be good.

However, in the case where the narrowed portion 21e is formed by the notch 21d, the contour is narrowed inward from the outer shape (the shape shown by the alternate long and short dash line in FIG. 4) when there is no notch 21d (in FIG. 4). The shape shown by the solid line). Due to the external magnetic field J, the magnetic flux in the vicinity of the magnetic-resistant plate 21 is attracted to the inside of the magnetic-resistant plate 21 if the outer shape of the magnetic-resistant plate 21 is a two-dot chain wire shape, and if it is a solid wire shape, the inside of the magnetic-resistant plate 21. May not be attracted to.

That is, the magnetic-resistant plate 21 in which the narrowed portion 21e is formed by the notch 21d has a smaller absolute amount of magnetic flux attracted to the inside of the magnetic-resistant plate 21 than the magnetic-resistant plate having the narrowed portion formed by removing the inner portion. To do. Therefore, the magnetic resistance plate 21 having the narrowed portion 21e formed by the notch 21d is less likely to cause magnetic saturation in the narrowed portions 21c and 21e than the magnetic resistant plate having the narrowed portion formed by removing the inner portion.

Further, the constricted portion in the present invention may be a portion having a narrowed cross-sectional area through which the magnetic flux along the direction M of the magnetic field J, which is magnetically weakest with respect to the second hand motor 11, passes. Therefore, in the narrowed portion in the present invention, in addition to the portion where the cross-sectional area is reduced by reducing the dimension in the width direction (narrowing the width), the dimension in the thickness direction of the magnetic resistance plate is reduced (thickness is reduced). ) Therefore, the cross-sectional area may be reduced. Further, the narrowed portion in the present invention may be a portion formed by narrowing the width and reducing the thickness to reduce the cross-sectional area.

FIG. 7 shows the outer shape of the magnetically resistant plate 21 shown in FIG. 4 as shown by a two-dot chain line without the notch 21d, and the thickness of the portion of the magnetically resistant plate 21 corresponding to the notch 21d is different. It is a figure which shows the magnetic resistance plate 121 formed thinner than the part of (A), (A) is the plan view corresponding to FIG. 4, (B) is the sectional view which shows the cross section along the line AA in (A). ..
As shown in FIG. 7, the magnetic resistant plate 121 becomes a narrowed portion 121e having a thickness t2 thinner than the thickness t1 of the other portion with respect to the direction M of the magnetic field J, which is magnetically weakest with respect to the second hand motor 11. ..

In this way, the narrowed portion 121e in which the cross-sectional area of the magnetic-resistant plate 121 through which the magnetic flux passes along the direction of the magnetic field J is smaller than the cross-sectional area of the other portion by reducing the thickness is the same as that of the narrowed portion 21e. In addition, it is easier to induce magnetic saturation than other parts.
By inducing magnetic saturation in the narrowed portion 121e, the magnetic flux is dispersed in another path avoiding the narrowed portion 121e, and the dispersed magnetic flux passes through the magnetic resistance plate at the position of the second hand motor 11. As a result, the magnetic resistance performance of the magnetic resistance plate 121 at the position of the second hand motor 11 is relatively improved without increasing the size of the magnetic resistance plate 121.

By narrowing the width of the magnetic-resistant plate and reducing the thickness, the cross-sectional area of the portion of the magnetic-resistant plate through which the magnetic flux passes can be further reduced.
Further, by partially reducing the thickness to form the narrowed portion, it is possible to increase the space in the thickness direction for the portion where the thickness is reduced.
On the other hand, by narrowing the width to form the narrowed portion, it is possible to increase the space in the direction in which the surface of the magnetic resistance plate spreads.

The radio wave correction clock 1 and the movement 3 of the present embodiment have magnetic resistance plates 21 and 22 formed on the upper and lower sides of the second hand motor 11 respectively, but the electronic clock and the movement according to the present invention have the same embodiment. It is not limited. Therefore, in the electronic watch and the movement according to the present invention, a magnetic resistance plate is provided on only one of the upper and lower sides of the motor, and the magnetic resistance plate has a constricted portion formed around the coil of the motor, and the constricted portion is formed. It suffices if another constriction is formed on the upstream side of the magnetic field.

In the radio wave correction watch 1 and the movement 3 of the present embodiment, the magnetic resistance plate 21 is formed with a relief hole 21a for preventing interference with the coil 11a of the second hand motor 11, and between the relief hole 21a and the outer shape. , Another narrowed portion 21c, which is narrower than the other portions, is formed.

In the radio wave correction clock 1 and the movement 3 of the present embodiment, the constricted portions 21e and 22e are formed in the portions of the magnetic resistant plates 21 and 22 through which the magnetic flux along the direction M of the magnetic field J, which is the weakest magnetic field of the second hand motor 11, passes. However, the electronic clock and movement according to the present invention are not limited to this form.

The radio wave correction clock 1 and the movement 3 of the present embodiment include four step motors, a second hand motor 11, a dual minute and hour hand motor 12, a minute and hour hand motor 15, and a functional hand motor 16. As described above, the order thereof is as described above. Therefore, the priority required for magnetic resistance is high.
The radio wave correction clock 1 and the movement 3 of the present embodiment are magnetically most attached to the magnetically resistant plates 21 and 22 only for the second hand motor 11 having the highest priority required for magnetic resistance among the four step motors. A narrowed portion 21e is formed on the upstream side of the direction M of the magnetic field J in the weak direction.

However, in the radio wave correction clock 1 and the movement 3 of the present embodiment, in addition to the second hand motor 11, the anti-magnetic plate 21 and the anti-magnetic plate 21 are also used for the minute and hour hand motor 15 in which the magnetic resistance performance is required to have the second priority (driving frequency). In 22, another constriction may be formed on the upstream side in the direction of the magnetic field in the weakest magnetic direction.

In addition to the second hand motor 11 and the minute and hour hand motor 15, the radio wave correction clock 1 and the movement 3 of the present embodiment relate to the dual minute and hour hand motor 12, which has the third priority (driving frequency) for which magnetic resistance is required. In addition, another constriction portion may be formed on the magnetic resistance plates 21 and 22 on the upstream side in the direction of the magnetic field in the weakest magnetic direction.

Further, in the radio wave correction clock 1 and the movement 3 of the present embodiment, in addition to the second hand motor 11, the minute and hour hand motor 15, and the dual minute and hour hand motor 12, the priority (driving frequency) required for magnetic resistance is fourth. Regarding the functional needle motor 16, another constricted portion may be formed on the magnetic resistant plates 21 and 22 on the upstream side in the direction of the magnetic field in the weakest magnetic direction.
According to the radio wave correction clock 1 and the movement 3 formed in this way, constricted portions are formed on the magnetic resistance plates 21 and 22 in order from the step motor having the highest priority for which magnetic resistance performance is required. As a result, the magnetic resistance can be improved in the order of the step motors having the highest priority for which the magnetic resistance is required.

Since the magnetically weakest directions of the four step motors (second hand motor 11, dual minute and hour hand motor 12, minute and hour hand motor 15 and functional hand motor 16) are not necessarily the same, the constricted portion corresponding to each step motor. Does not always have the same orientation.

1 Radio wave correction clock 2 Case 3 Movement 7 Circuit board 11 seconds Hand motor 11a Coil 11c Rotor 21 and 22 Magnetic plate 21a Escape hole 21b Hole 21c, 21e Stenosis 21d Notch J Magnetic field L, M direction

Claims (7)

A motor and a magnetic resistance plate that covers the motor are provided.
In the magnetic resistance plate, a narrowed portion having a small cross-sectional area of the path through which the magnetic flux passes is formed in a portion on the upstream side in the magnetically weakest direction of the magnetic field acting on the magnetic resistance plate than the motor.
The narrowed portion is a movement of an electronic watch formed by making the thickness of the magnetic resistance plate thinner than other portions. The movement of an electronic timepiece according to claim 1, wherein the anti-magnetic plate has another constricted portion formed around the converter of the motor. The movement of an electronic watch according to claim 1 or 2, wherein the constricted portion is formed in a portion of a magnetic field in a direction substantially orthogonal to the direction connecting two slits of the stator of the motor on the upstream side with respect to the motor. .. The constriction, electronic timepiece movement according to any one of claims 1 or et 3 the width of the antimagnetic plate is formed narrower than the other portions. The magnetic resistance plate covers a plurality of motors, and the magnetic resistance plate covers a plurality of motors.
At least one of the motor, the anti-magnetic shield plate longitudinal and electronic timepiece movement according to any one of the claims 1, which is arranged in a direction orthogonal 4. Longitudinal direction as the motor disposed in a direction perpendicular to, electronic timepiece movement according to claim 5 which is a motor for driving the second hand of the antimagnetic plate. An electronic watch movement according to any one of claims 1 or et 6,
An electronic timepiece including a case for accommodating the movement.