JP2003194971A - Radio controlled timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a miniaturizable radio controlled timepiece which reliably and accurately detects a reference position. <P>SOLUTION: The winding direction of a drive coil 121b of a stepping motor 212 and the pole direction of its rotor 121c are predetermined to assemble the radio controlled timepiece. Pulse signals for driving the rotor 121c are inputted to a winding start and winding end terminals 121b', 121b'' of the coil 121b. A control circuit outputs to the motor 121 predetermined one of the pulse signals inputted to the winding start and winding end terminals 121b', 121b'' and also a detect instruction signal to a photo sensor 140 so that the sensor 140 emits light in a first state in which a needle wheel fixed to a needle is located at a reference position, using the relation between the first state and a second state at a specified time before the first state. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic correction timepiece that receives a time signal by radio waves and adjusts the time.

[0002]

2. Description of the Related Art A radio-controlled timepiece that uses radio waves among automatic correction clocks receives, for example, a long-wave standard time signal (JJY) that accurately conveys Japan Standard Time (JST) and corrects the time based on this received signal. It has a function of performing so-called zeroing. Then, when performing the zeroing, first, a pointer position detecting device is provided for accurately adjusting the position of the pointer to a reference time such as the hour.

A light detection sensor is generally used for detecting the position of the pointer, and the light detection sensor is roughly classified into a light reflection type sensor and a light transmission type sensor.

As a conventional radio-controlled timepiece equipped with a pointer position detecting device using a light reflection type sensor, for example, Japanese Unexamined Patent Publication No. Hei 6 (1999) -96242
The ones described in JP-A-222164 and JP-B-6-30793 are known. The radio-controlled timepieces disclosed in these publications include a first drive system for rotating a second hand gear, a second drive system for rotating a minute hand gear and an hour hand gear, and a first light for detecting the position of the second hand. A reflective sensor and a second for detecting the position of the minute and hour hands
A detection means such as a light reflection type sensor is provided.

The first light reflection type sensor and the second light reflection type sensor are formed of a light emitting element and a light receiving element, respectively, and are formed on the intermediate wheel and the hour hand wheel which constitute the first drive system. When the detection hole and the light-reflecting portion formed on the second hand wheel and the separately provided rotary plate respectively coincide with each other, the light-receiving element receives the light emitted from the light-emitting element to detect the pointer position. ing.

An example of a radio-controlled timepiece using a light-transmissive sensor is a radio-wave corrected automatic timepiece disclosed in Japanese Patent Laid-Open No. 2000-162336. In this radio-controlled timepiece, through holes are formed in the gear that constitutes the drive system that drives the second hand and the gear that constitutes the drive system that drives the minute hand and hour hand, and the light emitting element and the light receiving element are formed through the through holes. When the light emitted from the light emitting element is received by the light receiving element with the through holes facing each other, the pointer position is detected.

[0007]

However, particularly in the pointer position detecting device using the light transmission type sensor as described above, there are variations in the machining accuracy of parts such as gears and rattling of gears such as backlash. As a result, there is a possibility that the detection light emitted from the light emitting element will be deviated by about one step before and after, and the pointer position will be erroneously detected. Here, one step refers to a process in which the direction of the magnetic field that rotates the rotor that generates the driving force in the quartz timepiece changes, and the rotor makes a half rotation.

This erroneous detection is one of the gears used for position detection.
It tends to occur when the movement amount (rotation amount) per step is small. The amount of movement per step becomes smaller as the speed reduction ratio of the gear train of the drive system increases in order to move the pointer smoothly. Further, in order to reduce the time required for detecting the reference position, if the light-transmitting portion (through-hole) for position detection provided in the detection gear has a long hole shape, the possibility of erroneous position detection increases.

Further, the gears used for position detection must overlap at least on the optical path of the detection light emitted from the light emitting element. For this reason, there are restrictions on the arrangement of the gears that form the drive system in terms of design, and the pointer position detection device becomes thick, which is a factor that hinders the downsizing of the automatic correction timepiece. Further, if the detection gear is downsized and the amount of movement per step is reduced, the possibility of false detection is likely to occur as described above, which is another factor that makes it difficult to downsize the self-correcting timepiece. .

In view of the above-mentioned problems, in the present invention, automatic correction capable of miniaturization while enabling extremely highly accurate pointer position detection in which erroneous detection of the position for one step cannot occur. The purpose is to provide a watch.

[0011]

In order to achieve the above-mentioned object, the self-correcting timepiece of the invention includes a stator, a drive coil, and a rotor, which are used as a drive source of a pointer,
When at least one stepping motor for transmitting the rotational driving force of the rotor to the pointer and a pointer wheel directly connected to the pointer upon receiving a detection command signal receive a time signal and correct it at a predetermined time. A detecting means for detecting that the stepping motor is positioned at the reference position, a pulse signal for driving the stepping motor, and an operation for correcting at a predetermined time based on the output signal of the detecting means and the time signal are performed. And a control unit for controlling, and the detection means has a transmissive light detection sensor including a light emitting element that emits detection light and a light receiving element that receives the detection light emitted from the light emitting element and outputs a signal. The winding direction of the drive coil and the magnetic pole direction of the rotor are predetermined, and the drive coil changes the direction of the magnetic field generated in the stator, The control unit has a winding start terminal and a winding end terminal to which the pulse signals from the control unit are applied in order to rotate the rotor due to repulsion with the magnetic poles of the rotor. Of the pulse signal so that the light emitting element emits light in the first state by using the relationship between the first state and the second state that is a predetermined time before the first state. One of the predetermined pulse signals is output to the stepping motor, and the detection command signal is output to the detection means.

Preferably, the stepping motor includes a second hand stepping motor, and a first detection gear wheel, which is a second hand wheel directly connected to the second hand, is used for detecting the position of the second hand by the detecting means. The light-transmitting portion and the light-shielding portion are provided in a predetermined detection pattern on the same circumference around the rotation axis. More preferably, the first detection gear is an arc-shaped light transmitting portion having a predetermined width in the radial direction for transmitting the detection light from the detecting means, and a portion other than the light transmitting portion. Each of the plurality of light-shielding portions has a plurality of light-shielding portions, and the light-transmitting portions and the light-shielding portions of the first detection gear are arranged alternately, and one of the plurality of light-shielding portions is a circle more than other light-shielding portions. It is formed to be long in the circumferential direction by a predetermined length. The rotational driving force of the stepping motor for the second hand may be decelerated by an intermediate wheel and transmitted to the pointer.

Further, the stepping motor may include a stepping motor for the hour and minute hands, and in this case, the rotational driving force of the stepping motor for the hour and minute hands depends on the intermediate wheel used as the second detection gear. The speed is reduced and transmitted to the minute hand and the hour hand, and in the second detection gear, the light transmitting portion and the light shielding portion used for the position detection of the minute hand and the hour hand by the detecting means are the same with the rotation axis as the center. A rotating shaft is provided on a third detection gear wheel, which is a minute hand wheel directly connected to the minute hand, and a fourth detection gear wheel, which is a hour wheel directly connected to the hour hand, which are provided on the circumference in a predetermined detection pattern. A pattern of a light transmitting portion and a light shielding portion having a predetermined positional relationship with the detection pattern of the second detection gear is provided on the same circle around the center so that the positions of the minute hand and the hour hand can be detected. It is.

Preferably, the second detection gear has a predetermined width in the radial direction for transmitting the detection light from the detection means in a portion where the second detection gear overlaps with the third and fourth detection gears. At least one arc-shaped light-transmitting portion having a predetermined length in the circumferential direction and at least one light-shielding portion having a predetermined length in the circumferential direction, which is a portion other than the light-transmitting portion, are provided. The third and fourth detection gears have a circular arc-shaped light-transmitting portion having a predetermined width in the radial direction for transmitting the detection light from the detection means in a portion overlapping with the second detection gear, and the light-transmission portion. And a plurality of light-shielding portions that are portions other than the light-shielding portion, wherein the light-transmitting portions and the light-shielding portions of the third and fourth detection gears are alternately arranged and one of the plurality of light-shielding portions is provided. Is longer than other light-shielding parts by a predetermined length in the circumferential direction. It is made.

In the present invention, the winding direction of the drive coil and the direction of the magnetic poles at the stationary position of the rotor are defined in advance. Further, by clearly distinguishing the winding start terminal and the winding end terminal of the drive coil, and predetermining the direction of the magnetic field generated in the stator when a pulse signal from the control unit is input to each terminal, It is possible to know which direction the magnetic poles of the rotor are facing when a pulse signal is input to each of the two terminals.

The control unit outputs a detection command signal so that the light detection sensor emits and receives the detection light in a predetermined relationship with the output timing of the pulse signal input to one of the terminals. For example, the detection signal of the photodetection sensor can be obtained every time the rotor is oriented in a predetermined magnetic pole, that is, every predetermined step.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

First, a general time detection method by a standard radio wave of a radio-controlled timepiece as an automatic correction timepiece will be described. Generally, a radio-controlled timepiece receives a standard radio wave (JJY) containing time information (time code information),
The time is corrected based on the time code information.

FIG. 1 is a block diagram showing an example of the configuration of a signal processing system circuit of a radio-controlled timepiece as an automatic correction timepiece according to the present invention. In the figure, the signal processing system circuit 10 has a standard radio wave reception system 11, an oscillation circuit 13, a control circuit 14, a buffer circuit 17, and a light transmission type photodetection sensor 140.

The standard radio wave reception system 11 receives, for example, a reception antenna 11a and a standard radio wave including a time code transmitted from a transmitting station, performs a predetermined process, and outputs a pulse signal S11.
And a long-wave receiving circuit 11b that outputs the control signal to the control circuit 14. This long wave receiving circuit 11b is, for example, RF
It is composed of an amplifier, a detection circuit, a rectification circuit, and an integration circuit.

Note that the standard radio wave reception system 11 receives
Fig. 2 shows the longwave standard radio wave that conveys Japan Standard Time with high accuracy.
It is sent in the form shown in (a).

Specifically, the time code is a "1" signal,
It is composed of three types of signal patterns of "0" signal and "P" signal, and each signal pattern is 1 in 1 second (s).
They are distinguished by the width of the 00% amplitude period. That is,
When representing a "1" signal, 500 ms during 1 second (s)
A signal of a predetermined frequency is transmitted for (0.5s),
800 ms during 1 second (s) to represent "0" signal
The signal of the predetermined frequency is transmitted only for (0.8s), and "P"
When representing a signal, 200ms (0.2
Only s), a signal of a predetermined frequency is transmitted. When the reception condition is good, the standard radio wave reception system 11 outputs a signal S11 as a pulse signal corresponding to the signal of the standard radio wave to the control circuit 14 as shown in FIG. 2B.

The standard radio wave in Japan is 12 December 2001.
As of January 1, it is operated under the Communications Research Laboratory (CRL). As the frequency of the standard radio wave, a frequency of 40 kHz has been used so far.
From 1st October, a transmission station that transmits 60kHz standard radio waves has also been opened. The maximum amplitude of the modulated wave is 100.
%, The minimum is 10%.

Next, the transmission data of the long wave standard radio wave will be described. FIG. 3 shows an example of the time code of the standard radio signal. As shown in FIG. 3, the time code is divided into 60 with a period of 1 minute (1 frame), and 1-bit information is allocated every 1 second and transmitted.

The information transmitted by the time code is hour, minute, 1
The day of the month, the year (last 2 digits of the year), the day of the week, the leap second information, the parity corresponding to the hour and minute, the spare bit, and the notice of the stoppage of the wave. Of these, the hour, minute, and January 1st The binary number (BCD (BCD (BCD (BCD)
inary Coded Decimal Notation: Binary coded decimal system) Positive logic) and transmitted. Therefore, sometimes 24-hour JS
To represent the hour of T, 6 bits are needed for the minute, 7 bits for the minute, 10 bits for the total day, 8 bits for the year, and 3 bits for the day of the week. Regarding the second signal, the second is the rising edge of the pulse signal of the radio wave, and the 55% value (the center of the 10% value and the 100% value) of the rising edge of the pulse is synchronized with the standard one second signal.

The P signal is transmitted 7 times in one frame, and the one corresponding to the minute (0 second) is called the marker M, and 9 seconds,
Those corresponding to 19 seconds, 29 seconds, 39 seconds, and 49 seconds are called position markers P1 to P5, respectively. The other position marker P0 normally corresponds to the rising of 59 seconds (at the time of non-leap second). The P signal continuously appears once in one frame at 59 seconds, 0 seconds,
That is, only when the position marker P0 and the marker M continue, the position that appears in succession becomes the straight position. In other words, the position of the time data such as minute / hour data is determined in the frame with reference to this right-minute position, so the time data cannot be extracted unless the right-minute position is accurately detected.

However, the format of the frame of the standard radio wave is not the same every minute, and as shown in FIG.
The formats of the 5 minutes and 45 minutes are different from the formats of the other minutes. As will be described later, the spare bits and the leap second information are 15 minutes and 45 minutes shown in FIG.
It is included only in the formats other than the minutes, and as shown in FIG. 3B, the calling code and the wave stop information appear only in the formats of 15 minutes and 45 minutes instead of the year information and the day of the week information. The spare bits, leap second information, and wave stop information will be described below.

The reserved bits are SU as shown in Table 1.
1, use bits labeled SU2. These are prepared for future information expansion. When this bit is used in summer time information, SU1 = SU2
= 0, "no change to daylight saving time within 6 days", SU1 = 1
・ SU2 = 0: "There is a change to daylight saving time within 6 days", SU
When 1 = 0 and SU2 = 1, "during summer time", SU1 = SU2 =
In No. 1, the information format is such that "daylight saving time ends within 6 days." Regarding the switch to daylight saving time, daylight saving time has not yet been introduced in Japan, and it is still unknown, but when you look at the change of daylight saving time in Europe,
I often go there during the night.

[0029]

[Table 1]

The next leap second is LS as shown in Table 2.
1, using 2 bits named LS2, LS1 = LS2
= 0, "No leap second correction is made within one month", LS1 = 1 and LS2 = 0 "Negative leap second (deleted) within one month", that is, 1 minute is 59 seconds, and LS1
In the case of = LS2 = 1, "there is a positive leap second (insertion) within one month", that is, one minute is 61 seconds. The timing for the leap second correction has already been determined, and will be performed immediately before January 1st or July 1st of Coordinated Universal Time (UTC) time. Therefore, in Japan time, it will be held on January 1 or July 1 just before 9:00 am. The leap second information is continuously transmitted from 9:00 on the 2nd day of the previous month to 8:59 on the 1st day of the execution month.

[0031]

[Table 2]

The wave stop information is ST1, ST2, ST3, ST4, ST5, ST6 as shown in (a), (b) and (c) of Table 3.
Using the bit named, ST1, ST2, and ST3 provide the notice of the start of the wave stoppage, ST4 gives the notice of the stoppage time period, and ST5 and ST6 give the notice of the stoppage period. First, the notice of the start of the wave stop will be explained. When ST1 = ST2 = ST3 = 0, “No wave stop schedule”, ST
When 1 = ST2 = 0 and ST3 = 1, "stops within 7 days", ST1
= 0 / ST2 = 1 / ST3 = 0 "stops within 3 to 6 days", ST1 = 0 / ST2 = ST3 = 1 "stops within 2 days", ST1 = 1 / ST2 = ST3 = 0 "Stops within 24 hours", "ST1 = 1 / ST2 = 0 / ST3 = 1" indicates "Stops within 12 hours", ST1 = ST2 = 1 / ST3 = 0 indicates "Stops within 2 hours" Has become. Next, notice the ST
4 = 1 means "only during daytime", and ST4 = 0 means "all day or no scheduled wave stop". Next is ST5 = ST
6 = 0 means "no scheduled stop", ST5 = 0 / ST6 = 1 means "7 days or more, or unknown period", ST5 = 1 / ST6 =
0 indicates "stops within 2 to 6 days", and ST5 = ST6 = 1 indicates "stops within 2 days".

[0033]

[Table 3]

The above is the principle of time acquisition using the standard radio wave, but the time input by an external device or manually may be adopted as the target time at the time of correction.

After the time is obtained, the hands of the clock are moved according to the time to correct the time of the clock. Less than,
Regarding an example of the method for adjusting the time of this timepiece, it has a motor for driving the second hand and a motor for driving the minute hand and the hour hand.
A motor automatic correction clock will be briefly described as an example.

When it becomes necessary to correct the time, first the pointer is moved to the reference position. After that, the difference between the reference position and the acquired time is detected, and the pointer is moved to the target time. In detail, when moving the pointer to the reference position,
The control circuit 14 sends the control signal CTL ₁ to the stepping motor 121 which is the power source of the second hand drive system and the control signal CTL ₂ to the stepping motor 131 which is the power source of the hour and minute hand drive system to fast forward each pointer. The fast-forwarding of the pointer is ended when the pointer position detecting means confirms that the pointer has moved to a predetermined reference position.

The control circuit 14 includes a minute hand counter, a second hand counter, a standard minute / second counter, etc. using a basic clock of a predetermined frequency generated by the oscillator circuit 13 using the crystal oscillator CRY and supplied to the control circuit 14. An internal clock including a counter is provided and continues counting the time based on the input time even when the hands are fast forwarded. Using the time of this internal clock as the target value, the control circuit 14 obtains the amount by which each pointer should be moved, and outputs control signals CTL ₁ and CTL ₂ to the stepping motors 121 and 131 via the buffer 17 to set each pointer to the target time. Move to and correct the clock time.

In the following, one embodiment of the present invention in which the time is adjusted by the above method will be described in more detail with reference to the drawings. In the present embodiment, a two-motor step automatic correction timepiece of step movement in which the second hand is instantaneously moved from one display position to the next display position every second will be described.

FIG. 4 is a sectional development view showing the construction of an embodiment of a pointer position detecting device of an automatic correction timepiece for step movement as an example of the present invention, and FIG. 5 is a plan view of a main part of the pointer position detecting device. It is a figure. Further, FIG. 6 shows the gear train configuration in which only the gear for driving the pointer is extracted from FIG.

The pointer position detecting device main body 100 is connected to face each other to form a lower case 111 and an upper case 112, and a lower case 111 in the space formed by the lower case 111 and the upper case 112. The intermediate plate 113 arranged in a connected state is provided, and the first hand for driving the second hand, which is the first pointer, with respect to predetermined positions of the lower case 111, the intermediate plate 113, and the upper case 112 in the space. 1 drive system, that is, the second hand drive system 120, a second drive system for driving the hour and minute hands that are the second hands, that is, the hour and minute hand drive system 130, the transmission type light detection sensor 140, and the time manually. A manual correction system 150 for correcting the time, a second hand drive system 120, an hour / minute hand drive system 130, and a light detection sensor 140, and a circuit board 160 used for transmission of electric power and signals. It is constant or supported. A second hand wheel 123 connected to the second hand, a minute hand wheel 134 connected to the minute hand, and an hour hand wheel 136 connected to the hour hand are provided at approximately the center of the space formed by the lower case 111 and the upper case 112. And are arranged coaxially.

As shown in FIGS. 4 to 6, the second hand drive system 120 includes a notch type stator 121a, a drive coil 121b wound around an iron core 121d of the stator, and an iron core 121d of the stator 121a. The stepping motor 121 for the second hand constituted by the rotor 121c rotatably supported between the magnetic poles of the leg pieces opposed to the first pinion 121c 'of the rotor 121c. Gear) and this first 5th wheel 128
A second hand wheel 123 as a first detection gear (first pointer wheel) meshing with. In the present embodiment, the first fifth wheel & pinion 128 has 12 steps / revolution and the second hand wheel 123.
Has 60 steps / revolution.

The rotation direction, rotation angle, and rotation speed of the second hand stepping motor 121 are controlled based on the control signal CTL ₁ output from the control circuit 14. In addition,
As described above, in the present embodiment, the control circuit 14 oscillates the pulse output once to pulse-drive the stepping motors 121 and 131 as the minimum unit when considering the movement of the drive system, and the drive coil is generated. The direction of the magnetic field to be changed is changed and the rotors of the stepping motors 121 and 131 make a half rotation, which is called one step. The actual length of the interval between steps is different between the normal hand movement and the fast-forwarding at the time correction, and also the second hand drive system and the hour / minute hand drive system. In the present embodiment, the second hand wheel 123 is 6 °.
/ It will rotate in steps.

In the present embodiment, only the second hand wheel 123 is used for detecting the reference position of the second hand. FIG. 7 shows a diagram of the second hand wheel 123 used in the present embodiment. Second hand wheel 12
3 has three arc-shaped elongated holes 123 each having a predetermined width in the radial direction and extending a predetermined length in the circumferential direction.
a, 123b, 123c and light-shielding portions 123d, 123e, 123f, which are the portions between the respective long holes, are alternately arranged on a concentric circle centering on the rotation axis of the second hand wheel 123. These elongated holes are arranged at positions where the light detected by the light detection sensor 140 can be transmitted. In the present embodiment, the central angles λ ₁ °, λ ₂ °, and λ ₃ ° of the elongated holes 123a, 123b, and 123c are respectively λ ₁ = 60 °,
λ ₂ = 81 ° and λ ₃ = 111 °. Also, the long hole 1
Central angle ψ ₁ ° between 23a and slot 123b, slot 123b
The central angle ψ ₂ ° between the long hole 123 c and the long hole 123 c and the central angle ψ ₃ ° between the long hole 123 c and the long hole 123 a are respectively ψ ₁ = 6.
0 ° and ψ ₂ = ψ ₃ = 24 °. ψ ₁ is ψ ₂ , ψ ₃
It is bigger than

The sizes of λ _{1 to} λ ₃ and ψ _{1 to} ψ ₃ do not necessarily have to be the above-mentioned values, but the reference position of the pointer is detected including the second to fourth detection gears described later. In consideration of this, it is desirable to satisfy a certain predetermined condition.

As will be described later in detail, when the second hand wheel 123 is rotated while emitting the detection light at a predetermined timing, an ON / OFF pattern of the light detection sensor 140 generated by the long hole of the second hand wheel 123 and the light shielding portion will be described. By discriminating, the second hand, that is, the reference position of the second hand wheel 123 is detected. As shown in FIG. 7, the second hand wheel 123 rotates counterclockwise when viewed from the upper case 112 side. Since the light shielding portion 123d of the second hand wheel 123 is longer than the other light shielding portions 123e and 123f,
If the OFF period by the light shielding unit 123d, which is longer than the OFF period by the light shielding units 123e and 123f, can be detected, it is understood that the second hand wheel 123 is located at a specific place at that time. In the present embodiment, the second hand directly connected to the second hand wheel 123 is set to indicate the hour, that is, 0 second, in the step in which the light detection sensor is first turned on after a long OFF period by the light shielding unit 123d. There is. The groove 123g of the second hand wheel 123 is for defining an initial position therefor. The second hand wheel 123 is assembled so that the groove 123g is located at a predetermined position. Then the second hand wheel 123
No matter how much it rotates, when the groove 123g returns to the assembled position, the long O
The first ON of the light detection sensor after the FF period is detected, and the second hand indicates 0 second.

FIG. 8 shows a state in which the reference position of the second hand wheel 123 is detected from two steps before the second hand wheel 123 reaches the reference position. 8A shows a state two steps before, FIG. 8B shows a state one step before, and FIG. 8C shows a state at the step when the second hand wheel 123 reaches the reference position. FIG. 8C corresponds to the first state in claim 1 of the present application, and FIG. 8B corresponds to the second state. In the first fifth wheel & pinion 128, its ring tooth portion meshes with the pinion 121c 'of the rotor 121c, and its pinion meshes with the second hand wheel 123. 8 (a) to (c),
Pinion 121c 'of the rotor 121c, the first fifth wheel 12
The 8 and the second hand wheel 123 rotate about the rotation axis in the directions of the arrows in the figure. Since the light detection sensor 140 does not move, the arrangement area 140a of the light detection sensor 140 and the position of the circular penetrating portion 140b for converging and passing the detection light of the light detection sensor 140 in the figure do not change.

In the present embodiment, in the state of FIG. 8B, the elongated hole 123b of the second hand wheel 123 partially overlaps the circular penetrating portion 140b in the arrangement region 140a (region RE of FIG. 8B).
Part). Since the radius of the circular penetrating portion 140b in the present embodiment is 0.5 mm, the above-mentioned overlap is caused by variations in the processing accuracy of parts such as gears and rattling of gears such as backlash, etc. It is easy to change to almost completely overlapping state. Therefore, if the ON / OFF of the light detection sensor 140 is detected at each step, the second hand wheel 123 in the state of FIG. 8B, which is one step before, is detected.
Has a possibility of being erroneously detected as having reached the reference position. Even if there is no variation or rattling of the gears as described above,
Leakage of the detection light of the light detection sensor 140 from the region RE may cause erroneous detection.

In the present embodiment, in order to prevent erroneous detection of this position, for example, in the steps of FIGS. 8 (a) and 8 (c), ON / OFF of the photodetection sensor is detected, and FIG. The detection is performed once every two steps so that the detection is not performed in the step b). As a result, erroneous detection does not occur even if disturbance such as gear shift occurs,
When the second hand wheel 123 reaches the reference position shown in FIG. 8C, it is surely detected that it is ON. As described above, the ON state at this time is long O due to the light shielding portion 123d.
It is the first ON after the FF period.

Since the second hand wheel 123 makes one revolution in an even number of steps, the position of the gear to be turned on is also turned on when both gears are returned to the same place again, and there is no deviation in detection. .

Each time the direction of the magnetic pole of the stator 121a changes, the rotor makes a half rotation and the gear advances by one step.
In order to realize the detection once every two steps,
The detection may be performed every time the magnetic pole of the stator 121a changes twice.

However, accurate reference position detection cannot be realized only by performing detection every time the magnetic pole of the stator 121a changes twice. This is because the direction of the magnetic field changes even if the winding direction of the drive coil wire changes.
This is because the step shifts depending on whether the detection is based on the pulse signal input to the start point or the end point of the conductor.

In order to eliminate this inconvenience, in the present embodiment, the winding direction of the conducting wire of the drive coil 121b is specified in advance when manufacturing the movement.
A winding start terminal 121b ′ and a winding end terminal 121b ″ are prepared so that the winding start and winding end of the conductor can be distinguished. The winding direction of the lead wire of the drive coil 121b is, for example, when the pulse signal for driving the stepping motor 121 is input from the control circuit 14 to the winding start terminal 121b ′ side, the directions of the N and S magnetic poles of the stator 121a are The direction is set as shown in FIG. As described above, for example, each time a pulse signal is input to the winding start terminal 121b ′, a detection command signal is output from the control circuit 14 to the photodetection sensor 140 to obtain the detection result of ON or OFF. In all products, it is possible to detect every two steps after aligning the directions of the magnetic poles at the time of detection.

However, when manufacturing the movement, the orientation of the magnetic poles of the rotor 121c and the stepping motor 121
Winding start terminal 121b 'and winding end terminal 1 when driving
It is necessary to preliminarily define which side of 21b '' the pulse signal is to be input first, and then to assemble. For example, when the rotor 121c is assembled so that the S pole of the rotor 121c faces the N direction shown in FIG. 5 and the N pole of the rotor 121c faces the S direction in a stationary state in which no electric power is supplied during assembly. deep. If the magnetic poles of the rotor 121c are misaligned, the S pole (N pole of the rotor 121c will be generated when the power is first turned on to generate a magnetic field that produces the N and S magnetic pole directions of the stator 121a shown in FIG. Each gear advances by the rotation angle until the N pole (S pole) of the stator 121a is attracted.

As described above, when assembling and manufacturing the timepiece,
The winding direction of the drive coil 121b, the direction of the magnetic poles of the rotor 121c, the positional relationship of the reference position detection gear, and the timing of pulse input to either one of the winding start terminal 121b 'and the winding end terminal 121b''. By setting and so that the correct reference position of the pointer can be detected, it is possible to perform accurate time correction by detecting once every two steps without causing erroneous detection due to gear shift.

Hereinafter, the hour / minute hand drive system 13 which is the second drive system
The description will proceed for 0. The hour and minute hand drive system 130 is shown in FIG.
~ As shown in FIG. 6, the substantially U-shaped stator 13
1a, a drive coil 131b wound around one leg of the stator 131a, and a rotor 131c rotatably supported between magnetic poles of the other leg of the stator 131a.
Stepping motor 13 for hour and minute hands
1, a second fifth wheel & pinion 132 as an intermediate wheel that meshes with the pinion 131c 'of the rotor 131c, and a third wheel 5 for detection (second transmission gear) meshing with the second fifth wheel & pinion 132. The third wheel & pinion 133 and the third wheel meshing with the third wheel & pinion 133.
A minute hand wheel 134 as a detection gear (second hand wheel) and a back wheel 13 of the day as an intermediate wheel meshed with the minute hand wheel 134.
5 and an hour wheel 136 as a fourth detection gear (third pointer wheel) that meshes with the back wheel 135 of the day. Here, the stepping motor 131 for the hour and minute hands is controlled by the control circuit 1
4 based on the control signal CTL ₂ output,
The rotation angle and the rotation speed are controlled.

The third wheel 133 on the kana of the second fifth wheel 132
The teeth of the wheel mesh with each other, and the minute wheel 13
The ring tooth portion of No. 4 meshes with the pinion of the minute wheel 134, the ring tooth portion of the day back wheel 135 meshes with it, and the hour wheel 136 meshes with the pinion of the day back wheel 135. In the present embodiment, the third wheel & pinion 133 has 45 steps / rotation and the minute hand wheel 134.
Is 360 steps / revolution, and the hour wheel 136 is 4320 steps / revolution.

As shown in FIG. 9, the third wheel & pinion 133 has three arc-shaped long holes 133a each having a predetermined width in the radial direction and extending in the circumferential direction by a predetermined length. 133
b and 133c and light-shielding portions 133d, 133e and 133f, which are portions between the respective long holes, are alternately arranged on a concentric circle centered on the rotation axis of the third wheel & pinion 133. In the present embodiment, the long holes 133a, 133b, 1
The respective central angles λ ₄ °, λ ₅ °, and λ ₆ ° of 33c are λ ₄ = 96 °, λ ₅ = 56 °, and λ ₆ = 72 °, respectively. Further, the central angle ψ between the long holes 133a and the long holes 133b is ψ.
₄ °, central angle ψ ₅ ° between long hole 133b and long hole 133c,
The central angles ψ ₆ ° between the long holes 133c and the long holes 133a are set to ψ ₄ = 88 ° and ψ ₅ = ψ ₆ = 24 °, respectively. ψ ₄
Is larger than ψ ₅ and ψ ₆ .

On the minute hand wheel 134, as shown in FIG.
It has a specified width in the radial direction and a specified width in the circumferential direction.
Three arc-shaped long holes 134a, 13 extending the length
4b, 134c and the part between each long hole
The light-shielding parts 134d, 134e, and 134f are
They are arranged alternately on concentric circles centering on the rotation axis.
In the present embodiment, the long holes 134a, 134b,
Central angle λ of each of 134c₇°, λ₈°, λ₉°
Λ₇= 60 °, λ₈= 120 °, λ₉= 60 °
ing. In addition, the center between the long holes 134a and 134b
Angle ψ₇°, the central angle ψ between the long holes 134b and 134c₈
°, the central angle ψ between the long holes 134c and 134a₉°
Respectively ψ₉°, ψ₇= 60 °, ψ₈= Ψ₉= 30 °
is doing. ψ₇Is ψ₈, Ψ ₉Bigger than
It

In the hour hand wheel 136, as shown in FIG.
Three arc-shaped elongated holes 136a, 13 each having a predetermined width in the radial direction and extending a predetermined length in the circumferential direction.
6b and 136c and light-shielding portions 136d, 136e and 136f, which are portions between the respective long holes, are alternately arranged on a concentric circle around the rotation axis of the hour hand wheel 136.
In the hour wheel 136 of the present embodiment, the long hole 13
6a, 136b, 136c central angles λ ₁₀ °, λ ₁₁ °, λ ₁₂
Is λ ₁₀ = 90 °, λ ₁₁ = 77.5 °, λ ₁₂ =
It is set to 60 °. Also, the long holes 136a, 136b, 13
Since both ends of 6c are straight, the central angle ψ ₁₀ ° between the long holes 136a and 136b, and the long holes 13
6b and the long hole 136c, the central angle ψ ₁₁ °, the long hole 136c
The central angle ψ ₁₂ ° between the hole and the long hole 136a becomes the central angle of the light shielding portions 136d, 136e, 136f, respectively, and ψ ₁₀ = 27.5 °, ψ ₁₁ = 45 °, ψ ₁₂ = 60 °. ing.

In the present embodiment, the third wheel 133 is
The translucent portion for detecting the reference position is not a circular or substantially circular transmissive hole as in the past, but long holes 133a, 133b, 133.
c is provided. Therefore, as in the case of the second hand wheel 123, the third wheel 133 and the minute hand wheel 134 are used to determine the reference position.
It is necessary to distinguish the OFF pattern of the light detection sensor caused by the long hole and the light shielding part. As the reference position, as in the case of the second hand wheel 123, in the step in which the light detection sensor is first turned ON after the OFF period of the light shield 133d that is longer than the OFF period of the light detection sensor of the light shields 133e and 133f is detected. The minute hand directly connected to the minute hand wheel 134 indicates the hour, that is, 0 minute. The hole 133g of the third wheel & pinion 133, the groove 134g of the minute hand wheel 134, and the groove 136g of the hour hand wheel 136 are for defining the initial positional relationship therefor, and the hole 1g at a predetermined position.
When 33g and grooves 134g and 136g overlap, hour and minute hands
It is supposed to point to 2:00.

Manual correction system 15 shown in FIGS. 5 and 6.
0 has a back wheel 135 of the day that meshes with the minute hand wheel 134 and the hour wheel 136 described above, and a manual correction shaft 151 that meshes with the back wheel 135 of the day. This manual correction axis 151
It has a head 151a positioned outside the upper case 112 and allowing the user to directly touch his / her finger. The wheel tooth portion of the sun wheel & pinion 135 has a manual correction shaft 151 and a minute hand wheel 134.
By meshing with both of the kana, the manual correction shaft 151,
The minute hand wheel 134 is configured to rotate in the same phase as the minute hand wheel 134. When the minute hand wheel drive system 130 is driving the minute hand wheel 134, the minute hand wheel 1 is driven via the day back wheel 135.
While rotating in the same phase as 34, the head position 151a can be manually corrected by rotating the head portion 151a with a finger when the hour / minute hand drive system 130 is not operated.

As shown in FIG. 4, the transmissive light detection sensor 140 includes, for example, a light emitting element 142 formed of a light emitting diode attached to the lower case 111, and the light emitting element 1.
It is formed by a light receiving element 144 formed of a phototransistor attached to the upper case 112 so as to oppose to 42. Further, as shown in FIGS. 4 to 6, the light detection sensor 140 includes a second hand wheel 123, a third wheel & pinion 133, and a minute hand wheel 1
34 and hour hand wheel 136 are all arranged at the same time. Long hole 123a (or 123b or 123c) of the second hand wheel 123, long hole 133a of the third wheel & pinion 133
(Or 133b or 133c), the long hole 134a (or 134b or 134c) of the minute hand wheel 134, and the long hole 136a (or 136b or 136) of the hour hand wheel 136.
When c) are overlapped, the detection light emitted from the light emitting element 142 is received by the light receiving element 144, and the light detection sensor 140 is turned on. By using the arc-shaped elongated hole as described above, the chances of receiving the detection light are increased, and the time required to detect the reference position can be shortened.

Hereinafter, the light detection sensor 140 is turned on and off.
The time adjustment operation of the automatic adjustment timepiece according to the present embodiment using the above will be described with reference to FIGS. 12 and 13. 12
6 is a flowchart for explaining a reference position detecting operation of a pointer in the present embodiment. FIG. 13 shows pulse outputs SO1 and SO2 for driving the stepping motor 121 for the second hand driving system 120 and pulse outputs MHO1 and MHO2 for the stepping motor 131 for the hour and minute hand driving system 130 during the pointer position detecting operation. FIG. 6 is a diagram showing a light emission timing of a light emitting diode (LED) of the light detection sensor 140.

When adjusting the time, first, the control circuit 1
In response to the detection command signal from 4, the light emitting element 142, that is, the light emitting diode emits detection light. The detection light from the light emitting diode is detected by the light receiving element 144, that is, the phototransistor, and it is checked whether the phototransistor emits an output (STEP 1). Below,
The output of the phototransistor is turned on, and the output of the phototransistor is turned off. STEP1 is
As described above, this means checking whether or not the long holes provided in the second hand wheel 123, the third wheel 133, the minute hand wheel 134, and the hour hand wheel 136 are all overlapped on the light emitting diode.

When the phototransistor does not generate an output, that is, when it is OFF, the second hand stepping motor 121 of the second hand drive system 120 and the hour / minute hand stepping motor 131 of the hour / minute hand drive system 130 are both fast-forward driven by two steps. Yes (STEP2, STEP3). At this time, in synchronization with this fast-forward drive, as described above, the light emitting diode is caused to emit light once every two steps to check the ON / OFF state of the phototransistor. Here, if the pulse output SO2 is input to the winding start terminal 121b 'of the drive coil and the pulse output SO1 is input to the winding end terminal 121b'', the above description can be taken. As shown in FIG. 13, in the present embodiment, the pulse output SO1 and
The phases of SO2 and pulse outputs MHO1 and MHO2 match each other. Therefore, it is not necessary to separately set the number of fast-forwarding steps of the stepping motor 121 for the second hand driving system 120 and the stepping motor 131 for the hour and minute hand driving system.

The fast-forward operation in STEP2 and STEP3 is continued until the phototransistor is turned on, and when the phototransistor is turned on, both the stepping motor 121 and the stepping motor 131 are once stopped. This means that the position of the pointer may be anywhere, so the second hand wheel 123, the 3rd wheel 1
It is equivalent to confirming that the long holes provided in 33, the minute hand wheel 134, and the hour hand wheel 136 are all overlapped on the light emitting diode, and that the through holes through which the detection light can pass are formed.

Next, the second origin is searched, that is, the second hand is moved to the reference position of 0 second. Therefore, as shown in FIG. 13, the second hand drive system 12
Move only the stepping motor 121 for 0 to drive the second hand wheel 1
While driving 23 fast forward by 2 steps, the ON / OFF state of the phototransistor is checked (STEP 4). At this time, since the arc-shaped elongated hole is formed in the second hand wheel 123, the detection light penetrates the second hand wheel 123 and the phototransistor is turned on in most of the fast-forward driving, but in the present embodiment. Turns off the phototransistor
Count the number of steps in the state (STEP5).
During the 5 to 12 steps, if it is in the OFF state without turning ON even once, the stepping motor 1
21 is stopped and the second hand wheel 123 is stopped (STEP 6). This means that the first ON state after a long OFF period by the light shielding portion 123d of the second hand wheel 123 is detected, and at this time, as described above, the stop position of the second hand is exactly 0 second.

Finally, consider moving the positions of the hour and minute hands to the reference origin position. Therefore, the second hand wheel 123 remains stopped, and this time, the hour and minute hand drive system 130
Minute hand wheel 13 by moving only the stepping motor 131 for
4 is fast forward driven step by step (STEP 7).

Each time the minute hand wheel 134 is driven in one step, the number of steps in which the phototransistor is in the OFF state is counted (STEP 8). The pattern in the OFF state is the third wheel 133, the minute hand wheel 134, the hour hand wheel 13
In the case of the present embodiment, there are five types of A, B, C, D, and E shown in Table 4 depending on the shape of the long holes and the shape of the light-shielding portion.

[0070]

[Table 4]

In STEP7 and STEP8, the minute hand wheel 134 is driven via the third wheel, and accordingly the hour hand wheel 1
36 is naturally driven, and the number of steps in the OFF state is C:
When it is 280-449, the hour hand, that is, the minute hand is at the position indicating 4 o'clock, when D: 450-999 is at the position indicating 8 o'clock, and when E: 65-279 is at the position indicating 12 o'clock. is there. When the number of steps in the OFF state is B: 45 to 64, the minute hand, that is, the long hand, is in the state of pointing to 0 minute. OF
When the number of F is A: 0 to 44, it is in a state of none of them.

Therefore, after recognizing the number of OFF as C, the number of B is O
If the stepping motor 131 is stopped when the number of FFs is recognized, the pointer will stop at the position of 4:00 and turn OFF.
If the stepping motor 131 is stopped when the number of OFF is recognized after the number of B is recognized as D, the pointer is 8:
After stopping at the position of 00, recognizing the number of OFF as E, and then recognizing the number of OFF as B, the stepping motor 13
If 1 is stopped, the pointer will stop at the position of 12:00 (STEP 9). Actually 4:00, 8: 0
All of the hands stop at the position of the hands at the next time closest to the current time among the positions of the hands at 0,12: 00.

After the reference position of the pointer is defined in this way, as described above, the time of the internal clock provided in the control circuit 14 which is operated based on the received JJY is set as the target value, The control circuit 14 calculates the number of steps required to move the hands from the currently stopped reference position to the target time, and fast-forwards each hand to that position to complete the time adjustment.

In the present embodiment, only the second hand wheel 123 is used to detect the reference position of the second hand. In the conventional self-correcting timepiece, as shown in FIG. 14, for example, both the first fifth wheel & pinion 1280 and the second hand wheel 123 are used, and
The reference position of the second hand was detected without performing the detection once in each step. In the first fifth wheel & pinion 1280 used in FIG. 14, two circular through-holes 1280a are provided on a concentric circle centered on the rotation axis so as to face each other across the rotation axis. Since the first fifth wheel & pinion has a large amount of rotation per step, the through hole 1280a for transmitting the detection light for detecting the reference position is formed at such a separated position. The light-shielding portion of the first fifth wheel & pinion 1280 other than the through hole 1280a functions as a shutter. In the conventional self-correcting timepiece, the light detection sensor 140
When N and OFF are detected, leakage of detection light due to the overlap of the long hole 123b of the second hand wheel 123 and the circular penetrating portion 140b of the light detection sensor 140 at a place other than the reference position can be prevented by the first 5
The light-shielding portion of the wheel & pinion 1280 blocks the light to prevent erroneous detection.

However, in such a configuration, as shown in FIG. 14, the first fifth wheel & pinion 1280, the second hand wheel 123, and
The minute hand wheel 134, the hour wheel 136, and the third wheel & pinion 133 need to be overlapped all at least at the position where the light detection sensor 140 is arranged. Therefore, the first
The degree of freedom of layout of car No. 5 is low. Moreover, the thickness of the pointer position detecting device also becomes thicker. On the other hand, according to the present embodiment, since the second hand wheel 123 alone detects the reference position of the second hand, the first fifth wheel & pinion 128 is provided with the pinion 1 of the rotor 121.
21c 'and the second hand wheel 123 can be arranged anywhere as long as they mesh with each other. Therefore, the degree of freedom in designing the pointer position detecting device is increased. Further, it is possible to make the pointer position detecting device thin.

As described above, in this embodiment, the winding direction of the drive coil 121b and the rotor 121c are
The direction of the magnetic poles and the positional relationship of the gears for detecting the reference position are predetermined when the timepiece is assembled, and the timing is synchronized with the pulse input to either the winding start terminal 121b 'or the winding end terminal 121b''. Let the light detection sensor 1
With a simple configuration of acquiring the detection signal of 40, there is no possibility of erroneous position detection at the time of detecting the reference position of the second hand in all of the self-correcting timepieces to be manufactured, without requiring any special device. It becomes possible to detect once every two steps.

In the above embodiment, the first 5
Stepping motor 1 using the number wheel 128 as an intermediate vehicle
Although the rotational driving force of 21 is transmitted to the second hand wheel 123, if the predetermined reduction ratio is obtained, the second hand wheel 123 may be driven without using the first fifth wheel & pinion 128 to detect the reference position. it can. In the above embodiment, the second hand drive system 12
Although the position detection is performed every two steps using the mechanism of the present invention only in 0, the hour and minute hand drive system 130 can also be provided with a similar position detection mechanism, if necessary.
Further, for example, the present invention can be applied to a one-motor step automatic correction timepiece in which one motor drives three hands of a second hand and an hour / minute hand. In addition, for example, whether the detection means or the detection signal from the detection means is synchronized with the pulse signal to the winding start terminal or the winding end terminal, how many steps to perform the detection once, etc. Various changes are possible.

[0078]

According to the present invention, in an automatic correction timepiece such as a radio-controlled timepiece, even when the amount of movement per step of the gear used to detect the position of the hands is small, the simple structure ensures reliable and accurate operation. It is possible to provide an automatic correction timepiece that can detect a reference position and can be downsized.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing a configuration example of a signal processing system circuit of a radio-controlled timepiece according to the invention.

FIG. 2 is a diagram showing a signal pattern of a standard radio wave.

FIG. 3 is a diagram showing an example of a time code of a standard radio wave.

FIG. 4 is a sectional development view showing the overall configuration of one embodiment of a pointer position detecting device for a radio-controlled timepiece according to the invention.

5 is a plan view of a main part of FIG. 4. FIG.

FIG. 6 is a diagram showing a gear train configuration of the gears in FIG. 5;

FIG. 7 is a plan view showing a second hand wheel which is a part of a first drive system for driving the second hand.

FIG. 8 is a diagram showing how the reference position of the second hand wheel is detected.

FIG. 9 is a plan view showing a third wheel & pinion forming a part of a second drive system that drives a minute hand and an hour hand.

FIG. 10 is a plan view showing a minute hand wheel which constitutes a part of a second drive system which drives a minute hand and an hour hand.

FIG. 11 is a plan view showing an hour hand wheel which constitutes a part of a second drive system which drives a minute hand and an hour hand.

FIG. 12 is a flowchart for explaining a reference position detecting operation of a pointer in one embodiment of the radio-controlled timepiece according to the present invention.

FIG. 13 is a diagram showing a pulse output to a stepping motor and a detection timing of a light detection sensor during a pointer position detection operation.

FIG. 14 is a diagram showing an example of a wheel train configuration of gears of a pointer position detecting device in a conventional radio-controlled timepiece.

[Explanation of symbols]

10 ... Signal processing circuit 11 ... Standard radio wave reception system 14 ... Control circuit 17 ... Buffer circuit 111 ... Lower case 112 ... Upper case 113 ... Middle plate 120 ... First drive system (second hand drive system) 121 ... Stepping motor for second hand 121a ... stator 121b ... Drive coil 121b '... Winding start terminal 121b ″ ... Winding end terminal 121c ... rotor 121c '... Pinion 121d ... iron core 123 ... Second hand wheel (first detection gear, first pointer wheel) 123a, 123b, 123c ... elongated holes 123d, 123e, 123f ... Shading section 128 ... 1st 5th wheel (1st transmission gear) 130 ... Second drive system (hour / minute hand drive system) 131 ... Stepping motor for hour and minute hands 131a ... Stator 131b ... Drive coil 131c ... rotor 131c '... Pinion 132 ... the second fifth car 133 ... No. 3 wheel (second detection gear, second transmission gear) 133a, 133b, 133c ... elongated holes 133d, 133e, 133f ... Shading section 134 ... minute hand wheel (third detection gear, second hand wheel) 134a, 134b, 134c ... elongated holes 134d, 134e, 134f ... Shading section 135 ... behind the sun 136 ... Hour wheel (4th detection gear, 3rd pointer wheel) 136a, 136b, 136c ... elongated holes 136d, 136e, 136f ... Shading section 140 ... Light detection sensor (detection means) 142 ... Light emitting element 144 ... Light receiving element 150 ... Manual correction system

Claims (6)

[Claims] 1. A at least one stepping motor which is used as a drive source of a pointer, includes a stator, a drive coil, and a rotor, and transmits a rotational driving force of the rotor to the pointer, and receives a detection command signal. And a pulse signal for driving the stepping motor, and a detection means for detecting that the pointer wheel directly connected to the pointer is positioned at the reference position when the time signal is received and corrected at a predetermined time. And a control unit for controlling an operation of correcting the output signal of the detection means and a predetermined time based on the time signal, wherein the detection means emits detection light from a light emitting element and the light emitting element. A transmissive photodetection sensor including a light receiving element that receives the emitted detection light and outputs a signal, wherein the winding direction of the drive coil and the magnetic pole direction of the rotor are provided. It is predetermined, and the drive coil changes the direction of the magnetic field generated in the stator, and the pulse signal from the control unit is applied to rotate the rotor by repulsion with the magnetic pole of the rotor. The controller has a winding start terminal and a winding end terminal, and the control unit has a relationship between a first state in which the pointer wheel is positioned at a reference position and a second state a predetermined time before the first state. In order to cause the light emitting element to emit light in the first state, one predetermined pulse signal of the pulse signals is output to the stepping motor, and the detection command signal is output to the detection means. Automatically corrected clock. 2. The stepping motor includes a stepping motor for a second hand, and a first detecting gear, which is a second hand wheel directly connected to the second hand, has a light transmitting portion used for detecting the position of the second hand by the detecting means. 2. The self-correcting timepiece according to claim 1, wherein the light-shielding portion and the light-shielding portion are provided in a predetermined detection pattern on the same circumference around the rotation axis. 3. The first detecting gear is an arc-shaped light transmitting portion having a predetermined width in a radial direction for transmitting the detection light from the detecting means, and a portion other than the light transmitting portion. Each of the plurality of light blocking portions has a plurality of light blocking portions, and the light transmitting portions and the light blocking portions of the first detection gear are arranged alternately, and one of the plurality of light blocking portions is a circle more than other light blocking portions. The self-correcting timepiece according to claim 2, wherein the self-adjusting timepiece is formed to be long in the circumferential direction by a predetermined length. 4. The self-correcting timepiece according to claim 2, wherein the rotational driving force of the stepping motor for the second hand is decelerated by an intermediate wheel and transmitted to the second hand. 5. The stepping motor includes a stepping motor for the hour and minute hands, and the rotational driving force of the stepping motor for the hour and minute hands is reduced by an intermediate wheel used as a second detection gear and transmitted to the minute hand and the hour hand. The second detecting gear is provided with a light-transmitting portion and a light-shielding portion, which are used for detecting the positions of the minute hand and the hour hand by the detecting means, in a predetermined detection pattern on the same circumference around the rotation axis. The third detection gear, which is a minute hand wheel directly connected to the minute hand, and the fourth detection gear, which is an hour hand wheel directly connected to the hour hand, are provided on the same circumference around the rotation axis, 5. A pattern of a light transmitting portion and a light shielding portion having a predetermined positional relationship with the detection pattern of the second detection gear so that the positions of the minute hand and the hour hand can be detected. Automatic timepiece described. 6. The second detection gear has a circumference with a predetermined width in a radial direction for transmitting the detection light from the detection means in a portion where the second detection gear overlaps with the third and fourth detection gears. At least one arc-shaped light-transmitting portion having a predetermined length in the direction, and at least one light-shielding portion having a predetermined length in the circumferential direction that is a portion other than the light-transmitting portion. The fourth detection gear has an arc-shaped light-transmitting portion having a predetermined width in the radial direction for transmitting the detection light from the detection means at a portion overlapping with the second detection gear, and other than the light-transmitting portion. And a plurality of light-shielding portions that are portions of the third and fourth detection gears, and the light-transmitting portions and the light-shielding portions of the third and fourth detection gears are alternately arranged, and one of the plurality of light-shielding portions is It is formed longer than other light-shielding parts by a predetermined length in the circumferential direction. Automatic timepiece according to claim 5, wherein there.