JPH09197064A - Mechanism for detecting position of hands - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanism for detecting the position of electronic clock hands for improving the initial positioning operation of clock hands and achieving a reliable and inexpensive a hand-displayed electronic clock. SOLUTION: A motor drive circuit devices a step motor A 10, a clock hands wheel train A7, and a hand wheel 23, a deceleration wheel train is constituted at the next-stage position of the hand wheel 23, and at the same time, a wheel 29 for detecting the specific position of the hand wheel 23 is arranged, the wheel 29 constitutes a circuit block 19 and a clock hands position-detection switch which are electrically controlled, the reduction ration of the hand wheel 23 to the wheel 29 is N, and denominator N of the reduction ratio is an integer, thus simplifying the 0 alignment operation of the electronic clock hands.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting mechanism of a pointer wheel which constitutes a pointer wheel train for displaying time information of a pointer display type electronic timepiece.

[0002]

2. Description of the Related Art In recent years, a pointer display type electronic timepiece is not limited to simply displaying the time, and many multifunctional timepieces having various functions have come to be seen. For example, an electronic timepiece equipped with various functions such as a chronograph function, a timer function or an alarm function has been proposed.

An IC having such a function mounted on an electronic timepiece
In the case of a multi-function timepiece in which the drive of the pointer is controlled by a logic circuit, a method is generally used in which the initial operating position of the IC logic circuit and the initial position of the pointer are matched in advance by an external operation or the like. There are many. However, the initial positioning operation of the hands may be complicated and cumbersome and time-consuming, depending on the specifications of the timepiece, and is considered as a weak point for the multifunctional timepiece in terms of assembly work and after-sales service.

Under such circumstances, it has been proposed to add a pointer position detecting device to the timepiece movement mechanism in order to simplify the initial position adjusting operation of the hands. For example, when the external operation member is operated in accordance with the time signal (00 seconds), the second hand reaches the position of 00 seconds by fast forward and enters the standby state, and at the same time, the external operation switch works to reset the counter of the IC logic circuit, Further, the second hand is a method of maintaining a standby state until the deviation amount of 00 seconds from the position of the normal hand movement before fast-forwarding is eliminated.

The structure of the pointer position detecting device will be described with reference to FIGS. 5 and 6. FIG. 5 is a plan view of a main part of a conventional pointer position detecting device, and FIG. 6 is a sectional view of FIG. A fourth wheel & pinion 43, which receives a rotational force from a motor rotor 41 constituting the step motor 40, together with a coil (not shown) and a stator 42, performs one-rotational drive in 60 seconds. The fourth wheel & pinion 43 has a second hand (not shown) and a fourth switch cam 44 fixedly coaxially with the rotation center shaft 43a.
The fourth switch cam 44 having a substantially circular shape has a concave cutout shape 44a in a part of the outer peripheral shape and an elongated hole shape 4 on a surface opposite to the concave cutout shape 44a with respect to the rotation center 44c.
4d. On the outer peripheral side surface of the fourth switch cam 44,
The tip portion 45a of the switch contact spring 45 having an elastic force is pressed against the rotation center 44c of the fourth switch cam 44 by a slight contact pressure. Switch contact spring 45
Is a fourth switch spring ball 48 having a thin plate-shaped spring portion 45c made of a conductive member and a slit 48a for fine adjustment.
It consists of. The No. 4 switch spring ball 48 is fixed to the No. 4 switch support base 46 for fine adjustment for matching the phase of the tip 45a of the switch contact spring 45 and the position of the recessed notch shape 44a of the No. 4 switch cam 44. It can be rotated by being engaged with the fourth switch spring shaft 49, and engaging a driver having a special shape with the slit 48a provided on the upper surface side of the fourth switch spring ball 48.

The No. 4 switch spring shaft 49 engages with the No. 4 switch lead plate (2) 50 fixed to the No. 4 switch support base 46, and also the No. 4 switch support base 46.
To secure the base plate to the base plate 51, which is the base of the timepiece movement, through the number 4 switch lead plate (2) 50.
Is fastened to the screw tube 51a that is planted in the main plate 51, so that the VDD electrode, which is the ground of the timepiece movement, is electrically connected to the switch contact spring 45. Within the deflection range 45b of the switch contact spring 45, an electrical switch signal is sent to an IC chip (not shown) at a substantially intermediate position between the fourth switch spring ball 48 and the tip portion 45a of the switch contact spring 45. A fourth switch contact 47 for inputting is provided. The fourth switch contact 47 is the fourth switch lead plate (1) fixed to the fourth switch support base 46.
The third switch terminal 54 is fixed to the fourth switch lead plate (1) 53.
The fourth switch terminal 54 is electrically connected to a conductive pattern (not shown) that is electrically connected to an IC chip (not shown) that constitutes the circuit block 55. 3) Pressed by 58.

When the fourth wheel & pinion 43 is driven in a predetermined step in the clockwise rotation direction, the recessed notch shape 44a provided on the outer peripheral portion of the fourth switch cam 44 has a tip portion 45a of the switch contact spring 45. Concave notch shape 4 near the
4a arrives, and at the next driving of the second wheel & pinion 43, the tip end portion 45a of the switch contact spring 45 instantly becomes a recessed notch shape 44a.
It is designed to fall into the valley portion 44b. However, when the fourth wheel & pinion 43 is driven in the counterclockwise direction, the tip 45a of the switch contact spring 45 abuts against the trough portion 44b of the recessed notch shape 44a, so that the fourth wheel & pinion 43 cannot rotate. Tip portion 45a of the switch contact spring 45
Is dropped to the valley portion 44b of the recessed notch shape 44a, the operation from the stationary position to the dropping position is completed while the fourth wheel & pinion 43 is being driven in one step, and the switch contact spring 4
After assembling the timepiece movement, the fourth switch spring ball 48 and the fourth switch fine movement adjusting shaft 56 are operated and adjusted so that the tip portion 45a of No. 5 becomes free. The fourth switch fine movement adjusting shaft 56 engaged with the main plate 51
The rotation operation of the No. 4 switch support base 46 is performed on the eccentric shaft 56a.
The recessed notch shape 46a of the No. 4 engages, and further, two elongated holes 46b formed in the fourth switch support base 46,
46c serves as a guide and moves along the screw tube 51a and the fourth switch support base pin 51b planted in the main plate 51 to move the fourth switch support base 46 in a substantially extending direction of the switch contact spring 45. It is possible.

The operation of the switch contact spring 45 and the fourth switch cam 44 is such that the tip end 45a of the switch contact spring 45 once falls to the valley portion 44b of the recessed notch shape 44a during one rotation operation of the fourth wheel & pinion 43. When the switch contact spring 45 is pressed against the fourth switch contact 47, the VDD signal is transmitted from the switch contact spring 45 to the fourth switch contact 47,
Fourth switch contact shaft 57, fourth switch lead plate (1)
VDD signal to a second hand position detection circuit (not shown) which is a logic circuit by conducting to the fourth switch lead plate (3) 58 through 53 and the fourth switch terminal 54 and electrically conducting to the IC chip. Is input, and the time system is recognized so that the time point of the input is recognized and stored as the 0 position of the second hand.

[0009]

However, according to the above-mentioned conventional example, the battery as the power source of the timepiece has been made thinner and smaller in accordance with the recent market needs such as thinner and smaller watches. Along with this, the battery capacity tends to decrease, and the other need is to extend the battery life. In order to realize this, the IC chip drive current consumption is reduced and the step motor drive current consumption is reduced. Reductions are made,
As a result, the rotational drive torque of the step motor tends to decrease. Further, while the rotational driving torque of the pointer wheel itself which is rotationally driven from the step motor via the pointer wheel train is also reduced, the outer peripheral portion of the fourth switch cam in which the switch contact spring described above is fixed to the fourth wheel. In the structure that directly contacts the contact point, the contact load of the switch contact spring causes a large rotational load on the fourth wheel, which may cause a rotation failure of the step motor via the indicator wheel train. Therefore, the contact reliability of the switch mechanism constituting the pointer position detecting device may be significantly reduced.

Further, the timing at which the tip of the switch contact spring falls into the recessed notch shape of the No. 4 switch cam varies depending on the precision of the parts and the backlash of the train wheel when viewed from each individual clock movement. Since the desired fall timing may shift, fine adjustment of this fall timing must be done by mechanical work, so the number of parts increases due to an increase in work man-hours and an increase in fine adjustment mechanism. There is a risk of becoming a pointer position detection device that is unfavorable to.

Further, since the switch contact spring which comes into contact with the cam is made of an elastic member, there is a risk of chattering at the input of the switch. In addition, the number 4 wheel with the number 4 switch cam fixed is driven only in the clockwise direction, so for example, in the case of making a complicated pointer movement such that the pointer rotates forward or backward in a specific mode. It is a pointer position detection device that is not suitable for multi-function watches, which are often used.

An object of the present invention is to provide a pointer position detecting mechanism which is highly reliable and inexpensive in cost.

[0013]

In an electronic timepiece in which a step motor is controlled by a motor drive circuit and time information is displayed by a pointer via a pointer wheel train, the pointer wheel train is used for a pointer wheel to which the pointer is fixed. A deceleration train wheel is formed at a position of the next stage, and a train wheel for detecting a specific position of the pointer wheel is arranged. The train wheel is a circuit for electrically controlling the pointer train wheel and the pointer wheel through a step motor. The block and the switch mechanism are constituted, and the reduction gear ratio of the next wheel and wheel forming the reduction wheel train and the pointer wheel is 1 / N, and the denominator N of the reduction ratio is an integer.

According to this structure, in the case of the wheel & pinion which is interlocked with the pointer wheel driven by the step motor through the pointer wheel train, the reduction wheel train is made so that the wheel & pinion makes one revolution when the pointer wheel makes N rotations. Since it is configured, the rotary drive torque that the watch wheel can hold through the pointer wheel is larger than that of the pointer wheel, and the mechanical load of the pointer position detection switch mechanism that is composed of the circuit block and the watch wheel is set relatively freely. be able to.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan view of a main part of a timepiece module showing an embodiment of the present invention viewed from the back cover side of the timepiece with the 3 o'clock side facing upward. FIG. FIG. 3 is a plan view of the main part of FIG. 3, FIG. 3 is a cross-sectional view of the main part of FIG. 1, and FIG. 4 is a block diagram of the timepiece system. 1, 2, 3,
In FIG. 4, the same numbers indicate the same components.

In FIG. 1, reference numeral 4 denotes a base plate which is a base of the timepiece movement and is composed of a thin flat plate and forms an outer profile of the timepiece movement. In the 12 o'clock direction (right side in FIG. 1) with respect to the center of the timepiece movement, the step motors A, 10 and 1 o'clock for driving the second hand 1 (see FIG. 3) via the hand wheel trains A, 7 In the direction (upper right side of FIG. 1), step motors B and 11 for driving the minute hand 2 and hour hand 3 via the hand wheel trains B and 8, and the hand wheel train in the 5 o'clock direction (upper left side of FIG. 1). Step motors C and 12 for driving a date plate 39 (see FIG. 4) for displaying the date of the calendar via C and 9 are provided. In addition, 1
A battery 13 which is a power source of the electronic timepiece is arranged in the 0 o'clock direction (on the lower right side of FIG. 1), and on the surface opposite to the battery 13 with respect to the axial extension line of the winding stem 15. , Circuit block 19
Mounted on the circuit board 20 constituting the
An IC chip 21 forming a logic circuit such as a motor drive circuit 21b and a switch control circuit 21c, and a crystal oscillator 22 forming a reference oscillator are provided.

A winding stem 15 which is an external operation member arranged in the 3 o'clock direction of the timepiece movement is engaged with a mandrel 16 which constitutes an already known external operation switching mechanism, and the mandrel 16 is integrated with the back holder 17. It is positioned by the jump control portion 17b provided at the tip of the jump control spring 17a. Further, the mandrel 16 is equipped with switch springs A and 18 that constitute input switches A and 36 (see FIG. 4) that perform electrical control in conjunction with the pulling and pushing operation of the winding stem 15. There is. The switch springs A and 18 are formed by elastically deforming a spring portion 18a and a switch contact portion 18b integrally formed at the tip of the spring portion 18a. The switch contact portion 18b is a conductive pattern provided on a circuit board 20. By touching (not shown) the IC chip 21
The switch signal is input to the IC chip 21.

Here, the pointer wheel train A will be described with reference to FIG. Reference numeral 10 denotes a step motor A which is rotationally driven by one step per second by a motor drive pulse transmitted from the circuit block 19, and includes coil blocks A, 26,
It is composed of stators A and 27 and motor rotors A and 28. The second wheel 23 to which the second hand 1 is fixed is driven by the motor rotors A and 28 via the second intermediate wheel 24, and is arranged at a substantially central position of the timepiece movement. The pointer wheel train A, 7 includes a deceleration wheel train from the motor rotor A, 28 to the second intermediate wheel 24, the second wheel 23 so that the second wheel 23 makes one rotation in 60 seconds. It has a pinion portion 23a for transmitting a rotational force to a wheel & pinion driven at a reduction ratio of 1/4 to the position of the next stage, that is, a switch wheel 29.

Next, the pointer position detecting switch constituting the pointer position detecting mechanism will be described in detail. In FIG. 3, a switch wheel 29 that receives a driving force from the second wheel 23 is rotationally driven at a deceleration of 1/4 of the rotation speed of the second wheel 23, and its structure is a switch gear 32, a switch contact spring 30, a switch shaft. And a step portion 31a of the switch shaft 31.
The switch contact spring 30 is mounted on the switch contact spring 30, and the switch gear 32 is press-fitted and fixed to the engaging portion 31b of the switch shaft 31 to fix the switch contact spring 30 to the switch shaft 31. Driving is performed with the center hole 31c formed in the portion as the center of rotation. A spring portion 30 that is elastically deformable in the outer peripheral direction of the switch contact spring 30.
a, 30c, and contact portions 30b, 30d for contacting the tips of the spring portions 30a, 30c with the conductive patterns 20a, 20c arranged on the circuit board 20. The switch contact spring 30 has a distance (contact points 30b, 3d) connecting the contact points 30b, 30d and the rotation center of the switch wheel 29.
Two contact springs A, 30a with different turning radius 0d)
The contact springs B and 30c are the rigid portions 3 of the switch contact spring 30.
0e is integrally formed. The switch gear 32 has escape holes 32a and 32b so that the contact springs A and 30a and the contact springs B and 30c provided in the switch contact spring 30 do not interfere with the switch gear 32 in cross section.

On the circuit board 20 constituting the circuit block 19, two kinds of conductive patterns, that is, a VDD electrode pattern 20a constituting a position detection switch and a switch terminal pattern 20c are formed around the switch wheel 29. Both the patterns are electrically connected to the IC chip 21. The VDD electrode pattern 20a has a contact portion 3 so that the contact portion 30b of the contact spring A30a is constantly in pressure contact with each other to form an electrical conduction path except for a part of the notch 20b.
A conductive pattern shape wider than the sliding locus of 0b is formed. Further, the switch terminal pattern 20c is formed with a local conductive pattern in a range in which the contact portion 30d of the contact spring B30c slides so as to be switched once by one rotation operation of the switch wheel 29. The VDD electrode pattern 20a has a cutout shape 2 so that only the peripheral portion of the switch terminal pattern 20c does not come into contact with the contact portion 30d.
0b.

The operation of the pointer position detecting switch 38 will be described with reference to FIG. In the state shown by the solid line in FIG. 2, in the normal hand movement state, the switch wheel 29 driven by the second wheel 23 is rotating clockwise. The switch contact spring 30 shown by a solid line rotates in synchronization with the switch wheel 29, the contact portion 30b electrically contacts the VDD electrode pattern 20a, and the contact portion 30d does not contact any conductive pattern. At the contact points 30b and 30d indicated by broken lines, the switch wheel 29 makes one revolution, the contact point 30b is in stable contact with the VDD electrode pattern 20a, and the contact point 30d is in contact with the switch terminal pattern 20c. Is shown. That is, this state shows a state in which the pointer position detection switch 38 is electrically switched. When the contact portion 30d shown by the broken line contacts the switch terminal pattern 20c, an electrical switch signal is input to the switch control circuit 21c. When the switch signal is input to the switch control circuit 21c, the needle position coincidence detection circuit 2
1d inputs the output signal from the switch control circuit 21c and the output signal from the needle position counter 21a to check the needle position matching state. For example, when the needle position matching state is deviated, the position deviation is detected. It is configured to be corrected by the needle position correction circuit 21e.

In recent years, the pointer display type three-hand electronic timepiece has a very small margin of rotational drive torque of the second wheel for fixing the second hand due to the battery size and battery life. It is not desirable to have the step motor in terms of performance, and there is a risk that it will stop choi and mis-rotate in the normal hand movement state, but the switch structure described above allows the shape, thickness, spring deflection of the switch contact spring to be set freely. Since it can be set to, the design and consideration can be taken to reduce the rotation drive torque of the second hand wheel as well as the reliability and durability of the contact part.

Next, a cross-sectional structure around the pointer wheel trains A and 7 and the switch wheel 29 will be described. In FIG. 3, reference numeral 4 is a base plate which is the base of the timepiece movement, and is a bearing for axially supporting the clearance holes 4a of the coil blocks A and 26 constituting the step motors A and 10 and the lower mortises of the pointer wheel trains A and 7. Four
b, 4c, etc. Reference numeral 5 denotes a train wheel bridge having bearings 5a, 5b, 5c and the like that pivotally support the upper hooks of the pointer wheel trains A and 7. In the hollow section of the main plate 4 and the train wheel bridge 5, a center pipe 6 in which a center pipe 6a that pivotally supports a center wheel & pinion 2 to which the minute hand 2 is fixed is press-fitted is arranged. A circuit board 20 forming a circuit block 19 is arranged at a cross-sectional position on the side opposite to the center bridge 6 with respect to the train wheel bridge 5. An insulating sheet 33 is provided between the circuit board 20 and the train wheel bridge 5 to prevent electrical shorts between the conductive patterns 20a and 20c arranged on the circuit board 20 and the train wheel bridge 5. ing.

In the hollow section of the main plate 4 and the train wheel bridge 5, a second intermediate wheel 24 constituting the motor rotors A and 28, a pointer wheel train A and 7, and a second wheel 23 for fixing the second hand 1 are arranged. Has been done. The second wheel 23 is provided with a pinion portion 23a for transmitting a rotational force to the switch wheel 29 arranged at the next stage position, between the train wheel bridge 5 and the second gear wheel 23b.
And the switch gear 32 mesh with each other to drive the switch wheel 29. The switch wheel 29 has a switch gear 32 and a switch contact spring 30 extending in a hollow section of the circuit board 20, and the contact portions 30b and 30d of the switch contact spring 30 are disposed on the lower surface side of the circuit board 20. The structure is such that the VDD electrode pattern 20a and the switch terminal pattern 20c are contacted while maintaining an appropriate elastic force in the cross-sectional direction. Further, a train wheel bridge 5 is provided on the outer periphery of the switch gear 32.
Is arranged so as to maintain a stable posture when the switch wheel 29 is assembled, and the shaft support of the switch wheel 29 is press-fitted and fixed to the center bridge 6 to the switch wheel shaft 6b. The structure is such that 31c is engaged. Reference numeral 34 denotes a winding stem spacer made of synthetic resin, which is equipped with the external operation switching mechanism 14, and has an inner wall 34a for preventing the motor rotors A and 28 from falling. 35 is the circuit board 20
Is a circuit support base for supporting in a cross-section.

Next, the coincidence between the pointer and the pointer position detecting mechanism and the operation of the timepiece in the normal use mode will be described. In FIG. 4, the initial phase alignment between the hand position counter 21a of the IC chip 21 that constitutes the circuit block 19 and the switch wheel 29 is performed by the input switch arranged in the timepiece movement in the process of hand setting in the process of assembling the timepiece. B, 37
When the switch signal is operated, the motor drive circuit 21b outputs a motor drive pulse by the switch signal to drive the step motors A and 10, drive the switch wheel 29 via the pointer train wheel A and 7, and drive the switch contact spring 30. Contact point 3
0c and the switch terminal pattern 20c are brought into contact with each other to change the ON state of the pointer position detection switch 38 to the switch control circuit 21c.
The motor drive pulse is controlled so as to stop the driving of the step motors A and 10 after the detection. After that, place the hands 1, 2, and 3 at predetermined positions (for example, 00:00).
Switch wheel 29 by sticking to (minute 00 second position)
The positional relationship between the second hand 1 and the second hand 1 is the same.

The hand position coincidence detection circuit 21d is constructed so as to confirm the operation of the pointer position detection switch 38 at regular intervals (for example, once every 24 hours) when the timepiece is in the normal hand movement state. For example, when there is a phase shift between the second hand 1 and the hand position counter 21a, the phase shift amount can be automatically corrected by a correction signal from the hand position correction circuit 21e.

Further, when a large time display deviation occurs immediately after the timepiece battery 13 is replaced, when the crown is pulled to correct the time, the above-mentioned input is performed in conjunction with the winding operation of the winding stem 15. The switches A and 36 are actuated, the switch contact portion 18b comes into contact with a switch pattern (not shown) arranged in the circuit block 19, and electrically VDD
It becomes conductive. In this state, the switch control circuit 21c
Is designed to input a reset signal to the motor drive circuit 21b. The motor drive circuit 21b transmits the fast-forward signal of the motor drive pulse to the step motors A and 10 to rotate the pointer wheel trains A and 7 until the ON position of the pointer position detection switch 38 is detected. Further, when the second wheel 23 and the switch wheel 29 are driven from the pointer wheel train A, 7 and the ON state of the pointer position detection switch 38 is detected, the motor drive circuit 21b stops the fast-forward signal of the motor drive pulse, and as a result, the second hand 1 Will stop at the 00 second position. In this way, the second hand 1 automatically reaches the 00 position when the crown is pulled, so that the time adjustment operation can be performed without being influenced by the movement of the second hand 1.

[0028]

As described above, according to the present invention, it is not necessary to finely adjust the drop timings of the No. 4 switch cam and the switch contact spring as in the pointer position detecting mechanism shown in the conventional example, and it is possible to assemble ordinary parts. As the watch movement is assembled in accordance with the above, the assembly time does not increase significantly, and a watch movement with a low cost needle position detection mechanism can be realized, and reliability that improves the operability of the watch It is intended to provide an electronic timepiece with a high pointer display type.

Further, by setting the reduction gear ratio of the pointer wheel to which the pointer is fixed and the next wheel constituting the reduction gear train to 1 / N and the denominator N of the reduction ratio to an integer, the driving rotation of the step motor can be performed. Since the spring force (contact force with the pattern) of the contact point spring that constitutes the pointer position detection mechanism can be set large according to the magnitude of the force, it is possible to secure electrical conduction reliability, Since the pointer position detection switch is switched at N times the number of rotations of the pointer wheel, operations such as shipping inspection and drive confirmation regarding the pointer position are easy to perform.

Although the embodiment of the present invention is intended to improve the operation of the zero return of the second hand by using the pointer position detecting device, for example, a similar device is provided for the hour wheel system wheel train. The position of the pointer that displays the time is installed by combining it with a pointer position detection device in which the pointer position detection switch turns on only once every 24 hours and detects the pointer position once every 24 hours. It is possible to automatically correct to match the time reference device mounted on the electronic timepiece, and it is possible to eliminate the pointer position shift due to external impact, which has often been a problem from the past.

Further, the pointer position detecting device of the embodiment of the present invention can be used for detecting the pointer position of a multi-function timepiece composed of a multi-hand, multi-motor.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a timepiece module showing an embodiment of the present invention viewed from the case back side of the timepiece with the 3 o'clock side facing upward.

FIG. 2 is a plan view of a main part of a pointer wheel train A and a number wheel, which shows an embodiment of the present invention.

FIG. 3 is a cross-sectional view of an essential part of FIG. 1 showing an embodiment of the present invention.

FIG. 4 is a block diagram of a timepiece system showing an embodiment of the invention.

FIG. 5 is a plan view of a main part of a pointer position detecting device showing a conventional example.

FIG. 6 is a cross-sectional view of a main part of FIG. 5 showing a conventional example.

[Explanation of symbols]

 1 second hand 5 wheel train bridge 6 center bridge 7 pointer wheel train A 10 step motor A 19 circuit block 20 circuit board 20a VDD electrode pattern 20c switch terminal pattern 23 seconds wheel 29 switch wheel 30 switch contact spring 30a contact spring A 30c contact spring B 32 switch gear 38 pointer position detection switch 44 fourth switch cam 45 switch contact spring 46 fourth switch support 47 fourth switch contact 48 fourth switch spring ball 51 base plate 53 fourth switch lead plate (1) 58 fourth switch lead Board (3)

Claims (3)

[Claims] 1. In an electronic timepiece in which a step motor is controlled by a motor drive circuit and clock information is displayed by a pointer through a pointer wheel train, the pointer wheel train 7 is next to a pointer wheel 23 to which the pointer 1 is fixed. A pointer position detecting mechanism characterized in that a reduction gear train is formed at a step position, and a watch wheel 29 for detecting a specific position of the pointer wheel 23 is arranged. 2. A circuit block 19 for controlling the position of the pointer wheel 23 is provided, and a switch mechanism 38 is constituted by the watch wheel 29 and the circuit block 19 which are arranged at a position next to the pointer wheel 23. The pointer position detecting mechanism according to claim 1, wherein the pointer position detecting mechanism comprises: 3. The reduction gear ratio of the pointer wheel 23 to which the pointer 1 is fixed and the next wheel wheel & pinion 29 constituting the reduction gear train is 1 / N, and the denominator N of the reduction ratio is an integer. The pointer position detecting mechanism according to claim 1.