JP2016206058A - Radio wave correction timepiece and time correction method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio wave correction timepiece capable of improving reception performance and of reducing a load of signal processing too, and a time correction method of the radio wave correction timepiece.SOLUTION: A radio wave correction timepiece comprises: a reception section receiving a standard radio wave and outputting a TCO signal obtained by demodulating a reception signal; a timing section timing internal time; a signal width detection section 411 detecting a signal width of the TCO signal; a code determination section 412 determining a code of the TCO signal on the basis of a detection value of the signal width detection section 411; and a time correction section correcting the internal time on the basis of the code determined by the code determination section 412. The code determination section 412 determines the code of the TCO signal to be a code corresponding to a specific code determination range when the detection value is included in the specific code determination range, and determines the code of the TCO signal on the basis of reference data when the detection value is included in a non-specific code determination range.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a radio-controlled timepiece that corrects time based on a standard radio wave and a time-correcting method for a radio-controlled timepiece.

A radio-controlled timepiece that receives a standard radio wave and corrects the internal time based on the received standard radio wave is known (for example, see Patent Document 1). The radio-controlled timepiece determines data “1”, “0”, “M (marker)” based on the signal width of the received signal, and acquires time data based on the determined data.
At this time, if the electric field strength of the received radio wave becomes weak due to the environment around the radio-controlled timepiece, the radio wave transmission conditions, and the like, the signal width of the received signal varies, and thus there is a possibility that the data is erroneously determined.
For this reason, the watch of Patent Document 1 receives a signal for 1 minute or 2 minutes, determines the data of each bit based on the signal width per second, checks the parity, matches the time data before and after, and the internal time. It is determined whether each of the data “1”, “0”, and “M” has been correctly determined from the received signal by any of the coincidence. When each data can be correctly determined, an average value of detection signal widths of 0 signal and 1 signal is obtained, and a difference between this average value and the actual signal width of 0 signal and 1 signal is obtained. Then, the signal width of the received signal is corrected with this difference and compared with a threshold value, so that a more correct determination can be made.

JP 2014-77695 A

  However, in the watch of Patent Document 1, after receiving data for 1 minute or 2 minutes, an average value of detection signal widths is obtained, and further, a difference from the original signal width is calculated. Data must be recognized by subtracting the difference from the detection signal width, which increases the signal processing load.

  An object of the present invention is to provide a radio-controlled timepiece and a time-correcting method for a radio-controlled clock that can improve reception performance and reduce the load of signal processing.

  The radio-controlled timepiece of the present invention includes a receiving unit that receives a standard radio wave and outputs a demodulated signal obtained by demodulating the received signal, a time measuring unit that measures the internal time, and a signal width detecting unit that detects the signal width of the demodulated signal A code determination unit that determines a code of the demodulated signal based on a detection value of the signal width detection unit; a time correction unit that corrects the internal time based on the code determined by the code determination unit; The code determination unit includes the code of the demodulated signal in the specific code determination range when the detected value is included in a specific code determination range preset as a range in which code determination based on the signal width is possible If the detected value is included in an unspecified code determination range set in advance as a range where code determination based on the signal width is not possible, refer to the code of the demodulated signal. And judging on the basis of the use data.

For example, when the standard radio wave to be received is the German standard radio wave “DCF77”, the specific code determination range is determined to be 0 signal, for example, a range longer than 0 ms and shorter than 125 ms, and 1 signal. For example, it is set in a range longer than 175 ms and shorter than 300 ms. The unspecified code determination range is set to a range of 125 ms or more and 175 ms or less where it is difficult to determine whether the signal is a 0 signal or a 1 signal.
The reference data is internal time or the like.
According to the present invention, when the detected value is included in the specific code determination range, the code of the demodulated signal is determined to be a code (0 signal or 1 signal) corresponding to the specific code determination range.
Further, when the signal width of the received signal is deviated from the original signal width (100 ms or 200 ms), the detected value is included in the unspecified code determination range, and the code of the demodulated signal cannot be determined based on the detected value, for reference A code is determined based on the data.
For this reason, even when the electric field strength of the received radio wave is weak and the signal width of the received signal varies due to the influence of noise, the code of the demodulated signal can be determined and the reception performance can be improved.
In addition, according to the present invention, since the code of the demodulated signal is determined, for example, it is not necessary to perform a process such as calculating a difference between the detected value and the original signal width, so that the processing load can be reduced.

  In the radio-controlled timepiece according to the invention, the specific code determination range includes a first code determination range in which the code of the demodulated signal can be determined as a first code, and a second code in which the code of the demodulated signal can be determined as a second code. It is preferable that the unspecified code determination range is set between the first code determination range and the second code determination range.

Here, the unspecified code determination range is set in the vicinity of an intermediate value between the original signal width of the first code and the original signal width of the second code.
For example, the first code is a 0 signal and the second code is a 1 signal. When the received standard radio wave is “DCF77”, the first code determination range is set to a range longer than 0 ms and shorter than 125 ms, for example, and the second code determination range is longer than 175 ms and shorter than 300 ms, for example. Set to The unspecified code determination range is set to a range of 125 ms or more and 175 ms or less, for example.
When the detection value is included in a range between the first code determination range and the second code determination range, the detection value is a value detected by increasing the signal width of the 0 signal or the signal width of the 1 signal. It is not possible to determine whether or not the detected value is shortened.
For this reason, when the interval between the first code determination range and the second code determination range is set as an unspecified code determination range, and the detected value is included in the unspecified code determination range, the demodulated signal is based on the reference code. Therefore, the possibility of erroneously determining the code of the demodulated signal can be reduced.

  In the radio-controlled timepiece according to the aspect of the invention, the reference data is the internal time, and when the detection value is included in the unspecified code determination range, the code determination unit converts the code of the demodulated signal into the internal time. It is preferable to make a determination based on the time.

  For example, when the radio-controlled timepiece receives a standard radio wave every day and corrects the internal time, the internal time is accurate and is likely to match the received signal. Therefore, the code of the demodulated signal can be accurately determined by determining the code of the demodulated signal based on the internal time.

  In the radio-controlled timepiece of the invention, the receiving unit receives a plurality of frames of the standard radio wave, the code determining unit determines a code of a demodulated signal of the plurality of frames, and the reference data includes the plurality of frames. It is a determination result of the code of the demodulated signal, and the code determination unit preferably determines the code of the demodulated signal based on the determination result when the detection value is included in the unspecified code determination range.

The code of the demodulated signal can be specified based on the determination result of the other frame if the code of the demodulated signal of the other frame is correctly determined.
Therefore, when the detected value is included in the unspecified code determination range, the code determination unit determines the code of the demodulated signal by determining the code of the demodulated signal based on the determination result of the code of the demodulated signal of a plurality of frames. Can be determined accurately.
Further, according to the present invention, since the code of the demodulated signal can be determined without using the internal time, the code of the demodulated signal can be determined even when the clock does not have the internal time such as after reset.

  In the radio-controlled timepiece according to the aspect of the invention, the receiving unit receives a predetermined number of frames of one or more frames of the standard radio wave, the code determining unit determines a code of the demodulated signal of the predetermined number of frames, and the code determining unit When the number of demodulated signals whose detection value is included in the unspecified code determination range among the demodulated signals of the predetermined number of frames is equal to or greater than a predetermined value as a result of determination by the time correction unit, It is preferable that the internal time is not corrected based on the code determined by the code determination unit.

  In this case, it is possible to determine that the reliability of the received signal is low when the number of demodulated signals whose demodulated signal is included in the unspecified code determination range is greater than or equal to the predetermined value among the demodulated signals of a predetermined number of frames. By not performing time correction, it is possible to prevent the internal time from being corrected by an inaccurate code.

A time correction method for a radio-controlled timepiece according to the present invention is a time correction method for a radio-controlled timepiece that includes a receiving unit that receives a standard radio wave and outputs a demodulated signal obtained by demodulating the received signal, and a time measuring unit that measures the internal time A signal width detecting step for detecting a signal width of the demodulated signal, a code determining step for determining a code of the demodulated signal based on the detection value detected in the signal width detecting step, and the code determining step. A time correction step of correcting the internal time based on the determined code, and the code determination step includes a specific code determination range in which the detection value is set in advance as a range in which code determination based on a signal width is possible Is included, the code of the demodulated signal is determined to be a code corresponding to the specific code determination range, and the detection value is determined based on the signal width. If it included in the preset unspecified code determination range as a range not ability, and judging on the basis of the code of the demodulated signal to the reference data.
According to the time correction method of the radio-controlled timepiece of the present invention, the same effects as those of the radio-controlled timepiece invention can be obtained.

1 is a block diagram showing a configuration of a radio wave correction timepiece according to a first embodiment of the present invention. It is a figure which shows the receiving pulse duty and amplitude change with respect to each signal of the standard radio wave "DCF77" in Germany. It is a figure which shows the time code format of the standard radio wave "DCF77" in Germany. It is a block diagram which shows the structure of the TCO decoding part of the electromagnetic wave correction timepiece in 1st Embodiment. It is a flowchart which shows the time correction operation | movement of the electromagnetic wave correction timepiece in 1st Embodiment. It is a figure which shows the example of distribution of the detected value of the signal width | variety detection part of the electromagnetic wave correction timepiece in 1st Embodiment. It is a figure which shows the relationship between the said detected value and determination result of the electromagnetic wave correction timepiece in 1st Embodiment. It is a figure which shows an example of the said detected value and determination result of the radio wave correction timepiece in 1st Embodiment, and the conversion data which converted internal time into TC. It is a flowchart which shows the time correction operation | movement of the electromagnetic wave correction timepiece which concerns on 2nd Embodiment of this invention.

[First Embodiment]
Hereinafter, a radio-controlled timepiece 1 according to a first embodiment of the present invention will be described with reference to the drawings.
[Configuration of radio-controlled clock]
As shown in FIG. 1, the radio-controlled timepiece 1 includes an antenna 2, a receiving circuit unit 3, a control circuit unit 4, a display unit 5, an external operation member 6, and a crystal resonator 48.
The antenna 2 receives a long-wave standard radio wave (hereinafter referred to as “standard radio wave”), and outputs the received standard radio wave signal to the reception circuit unit 3.

Standard radio waves include Japanese standard radio "JJY", United States standard radio "WWVB", German standard radio "DCF77", British standard radio "MSF", and Chinese standard radio "BPC".
In each standard radio wave, a signal is output by AM modulation in which the ratio of the amplitude of the high level signal and the amplitude of the low level signal is a predetermined ratio. Then, based on the signal width (or duty) of the high level signal or the low level signal, the 0 signal, the 1 signal, and the “M” signal (M signal) indicating the marker are determined.

For example, in “DCF77”, as shown in FIG. 2, a signal is output by AM modulation in which the ratio of the amplitude of the high-level signal and the amplitude of the low-level signal is 100: 25.
In “DCF77”, as shown in FIGS. 2A to 2C, when the signal width of the low level signal is 0.1 second (100 ms), that is, when the duty of the low level signal is 10%, One signal is recognized when the signal width of the level signal is 0.2 seconds (200 ms), that is, when the duty of the low level signal is 20%.
Further, in “DCF77”, the M signal is not subjected to AM modulation, and is recognized as an M signal when a high level signal continues for one second.

In each standard radio wave, time information is transmitted by using the signals 1, 0 and M in the time code format for each standard radio wave. Each standard time code format includes time information such as minutes and hours, and parity.
For example, in the time code format of “DCF77” shown in FIG. 3, one signal is transmitted every second, and one record is formed in 60 seconds. That is, one frame is 60-bit information. In addition, minutes, hours, days, days of the week, months, and years are set as information items. The minute bit string includes a parity bit P1, and the hour bit string includes a parity bit P2. Further, after the year bit string, a parity bit P3 for year, month, and sunday is set as a parity bit for date. The value of each information item is set by a combination of numerical values (0, 1) assigned every second (each bit).
That is, with each standard radio wave, a time code corresponding to the time code format for each standard radio wave is transmitted every minute.

  Returning to FIG. 1, the receiving circuit unit 3 demodulates the received signal of the standard radio wave received by the antenna 2 and outputs the demodulated signal to the control circuit unit 4 as a TCO (Time Code Out) signal. A detailed description of the receiving circuit unit 3 will be described later.

  The control circuit unit 4 decodes the input TCO signal to generate TC (time code, time data), and sets the time of the time counter 43 based on the generated TC. In addition, the control circuit unit 4 controls the display unit 5 to display the time of the time counter 43. The detailed description of the control circuit unit 4 will be described later.

  The display unit 5 is driven and controlled by the drive circuit unit 46 of the control circuit unit 4 and displays the time counted by the time counter 43. For example, the display unit 5 may include a liquid crystal panel and display the time on the liquid crystal panel. The display unit 5 may include a dial and a pointer, and the control circuit unit 4 may move the pointer to display the time. There may be.

  The external operation member 6 is constituted by, for example, a crown or a setting button, and outputs a predetermined operation signal to the control circuit unit 4 when operated by a user. As this operation signal, for example, a radio wave type setting signal for setting the type of standard radio wave received by the antenna 2 (for example, “JJY”, “WWVB”, “DCF77”, “MSF”, “BPC”, etc.) For example, a correction request signal for receiving a standard radio wave and correcting the time may be used.

  The crystal oscillator 48 for the reference clock outputs a predetermined reference signal (reference clock, for example, a 32.768 kHz signal). The reference signal output from the crystal oscillator 48 is input to the control circuit unit 4. ing.

[Receiver circuit configuration]
As shown in FIG. 1, the receiving circuit unit 3 includes a tuning circuit 31, a first amplifier circuit 32, a band-pass filter (BPF) 33, a second amplifier circuit 34, and an envelope detector circuit. 35, an AGC (Auto Gain Control) circuit 36 as an automatic gain control circuit, a binarization circuit 37, and a decoding circuit 38. Here, the receiving circuit unit 3 is a receiving unit of the present invention.

The tuning circuit 31 includes a capacitor, and the tuning circuit 31 and the antenna 2 constitute a parallel resonance circuit. The tuning circuit 31 causes the antenna 2 to receive a radio wave having a specific frequency. The tuning circuit 31 converts the standard radio wave received by the antenna 2 into a voltage signal and outputs the voltage signal to the first amplifier circuit 32.
The receiving circuit unit 3 of the present embodiment is configured to be able to receive standard radio waves such as “JJY”, “WWVB”, “DCF77”, “MSF”, “BPC”, and the like. Therefore, the antenna 2 and the tuning circuit 31 constitute a receiver that can receive a plurality of types of standard radio waves.

  The first amplifying circuit 32 adjusts the gain according to a signal (AGC voltage) input from an AGC circuit 36 described later, and inputs the received signal input from the tuning circuit 31 to the band pass filter 33 as a constant amplitude. Amplify. That is, according to the signal input from the AGC circuit 36, the first amplifying circuit 32 reduces the gain when the amplitude is large, and increases the gain when the amplitude is small. Amplify so that

The band pass filter 33 is a filter that extracts a signal in a desired frequency band. That is, by passing through the band pass filter 33, components other than the carrier wave component are removed from the received signal input from the first amplifier circuit 32.
The second amplification circuit 34 further amplifies the reception signal input from the band pass filter 33 with a fixed gain.

  The envelope detection circuit 35 includes a rectifier (not shown) and a low-pass filter (LPF) (not shown). The envelope detection circuit 35 rectifies and filters the received signal input from the second amplifier circuit 34, and performs filtering. The envelope signal thus obtained is output to the AGC circuit 36 and the binarization circuit 37.

The AGC circuit 36 outputs a signal for determining a gain when the first amplification circuit 32 amplifies the reception signal based on the envelope signal input from the envelope detection circuit 35.
The binarization circuit 37 compares the envelope signal input from the envelope detection circuit 35 with a reference voltage (threshold) and outputs a binarized signal, that is, a TCO signal. Here, the TCO signal is a demodulated signal of the present invention.

  The decode circuit 38 is connected to the control circuit unit 4 to be described later via a serial communication line SL. The decode circuit 38 decodes the control signal input from the control circuit unit 4 and outputs a control signal for controlling the tuning circuit 31 and the band pass filter 33 based on the code included in the control signal.

[Configuration of control circuit section]
The control circuit unit 4 controls the operation of the receiving circuit unit 3 and outputs a control signal to the receiving circuit unit 3. Specifically, the control unit 47 of the control circuit unit 4 outputs a control signal instructing switching of the tuning capacitor or switching of the bandpass filter 33 according to the received standard radio wave, and a power-on signal for starting the receiving circuit unit 3. Sent when sending.
Further, the control circuit unit 4 sets the time of the time counter 43 based on the TC obtained by decoding the TCO signal input from the binarization circuit 37. Furthermore, the control circuit unit 4 controls the display unit 5 to display the time of the time counter 43.

  As shown in FIG. 1, the control circuit unit 4 includes a TCO decoding unit 41, a storage unit 42, a time counter 43, a drive circuit unit 46, and a control unit 47.

The TCO decoding unit 41 decodes the TCO signal input from the binarization circuit 37 of the receiving circuit unit 3 and acquires a TC having date information and time information included in the TCO signal. Then, the TCO decoding unit 41 outputs the acquired TC to the control unit 47.
Specifically, as shown in FIG. 4, the TCO decoding unit 41 includes a signal width detection unit 411, a code determination unit 412, a determination result storage unit 413, and a TC acquisition unit 414.
The signal width detector 411 detects the signal width of the input TCO signal. The code determination unit 412 determines the code of the TCO signal based on the detection value detected by the signal width detection unit 411. The determination result storage unit 413 stores the determination result determined by the code determination unit 412. The TC acquisition unit 414 acquires a TC based on the determination result stored in the determination result storage unit 413.
The function of each part of the TCO decoding unit 41 will be described in detail in the description of the operation of the radio-controlled timepiece 1 described later.

Returning to FIG. 1, the storage unit 42 is a memory that stores various information and programs necessary for the control circuit unit 4 to control the receiving circuit unit 3.
The time counter 43 counts time (internal time) based on the reference signal output from the crystal resonator 48. That is, the time counter 43 is a time measuring unit of the present invention.

  The drive circuit unit 46 controls the display state of the display unit 5 based on the time display control signal output from the control unit 47 and controls the display unit 5 to display the time. For example, when the display unit 5 has a liquid crystal panel and displays the time on the liquid crystal panel, the drive circuit unit 46 controls the liquid crystal panel based on the time display control signal and displays the time on the liquid crystal panel. To control. When the display unit 5 has a dial and a pointer, the drive circuit unit 46 outputs a pulse signal to the stepping motor that drives the pointer, and controls the pointer to move by the driving force of the stepping motor. .

The controller 47 is driven based on the drive frequency input from the crystal resonator 48 and performs various control processes. The control unit 47 includes a time correction unit 471. The time correction unit 471 outputs the TC input from the TCO decoding unit 41 to the time counter 43, and controls to correct the count of the time counter 43.
The control unit 47 also outputs a time display control signal for causing the display unit 5 to display the time counted by the time counter 43 to the drive circuit unit 46.

[Operation of the radio-controlled clock]
Next, the time correction operation using the standard radio wave in the radio wave correction watch 1 as described above will be described.
FIG. 5 is a flowchart showing the time adjustment operation of the radio-controlled timepiece 1.

  The control unit 47 of the radio-controlled timepiece 1 activates the reception circuit unit 3 when an operation signal for performing time correction is input from the external operation member 6 or when it is recognized that the preset reception time is reached, Reception of the standard radio wave by the antenna 2 is started (S11).

At this time, the control unit 47 stops moving the second hand via the drive circuit unit 46 so as not to affect reception by the antenna 2. Further, the control unit 47 sets the frequency of the tuning circuit 31 according to the standard radio wave received.
The type of the standard radio wave to be received is set as the initial value of the previously received standard radio wave, but can be selected by operating the external operation member 6 by the user.
Here, as an example, a time adjustment operation when “DCF77” is received will be described.

When the reception of the standard radio wave by the antenna 2 is started in S 11, TCO signals are sequentially output from the binarization circuit 37 and input to the signal width detection unit 411 of the TCO decoding unit 41.
The signal width detector 411 detects the signal width of the input TCO signal (S12). Then, the code determination unit 412 determines the code (0 signal, 1 signal, M signal) of the TCO signal based on the detection value detected by the signal width detection unit 411. Here, the 0 signal is the first code of the present invention, and the 1 signal is the second code of the present invention.

FIG. 6 is a diagram illustrating a distribution example of detection values of the signal width detection unit 411.
For example, in “DCF77”, when the signal width is detected by the signal width detection unit 411 with respect to the received signal, the reception environment is good, the received signal does not include noise pulses, and the electric field strength of the received radio wave is sufficient. In this case, the detected value is 100 ms or 200 ms. However, actually, the detection value may be a value deviated from 100 ms or 200 ms due to the influence of a noise pulse or the like. Accordingly, as shown in FIGS. 6A and 6B, the distribution of the detected value of the 0 signal is a distribution that substantially follows the normal distribution with a peak of 100 ms, and the distribution of the detected value of one signal is 200 ms. The distribution substantially follows the normal distribution with the peak.
When the electric field strength of the received radio wave is relatively high, as shown in FIG. 6A, the distribution of detected values of 0 signal and the detected value of 1 signal do not overlap.
However, when the electric field strength of the received radio wave is relatively low, as shown in FIG. 6B, the distribution of the detected values of the 0 signal and the distribution of the detected values of the 1 signal overlap. For this reason, it is difficult to determine the code of the TCO signal for the detection values included in the overlapping range (boundary range A: 125 ms or more and 175 ms or less).

Therefore, when the signal width is detected in S12, the code determination unit 412 can determine whether the detected value is included in a specific code determination range in which code determination based on the signal width is possible or based on the signal width. It is determined whether it is included in the boundary range A. If the detected value is included in the specific code determination range, the code of the TCO signal is determined based on the detected value. If the detected value is included in the boundary range A, the code of the TCO signal is determined based on the internal time. Determine. Here, the boundary range A is an unspecified code determination range of the present invention.
That is, when the electric field strength of the received radio wave is relatively high, as shown in FIG. 6A, since the detection value is hardly included in the boundary range A, the code determination unit 412 almost always The code of the TCO signal is determined based on the detected value.
On the other hand, when the electric field strength of the received radio wave is relatively low, the detection value may be included in the boundary range A as shown in FIG. Therefore, the code determination unit 412 determines the code of the TCO signal based on the detection value when the detection value is included in the specific code determination range, and at the internal time when the detection value is included in the boundary range A. Based on this, the code of the TCO signal is determined. Even when the electric field strength of the received radio wave is low, the number of signals whose detection values are included in the boundary range A is about a few of the TCO signals for one minute.

  In other words, as shown in FIG. 5, when the signal width is detected in S12, the code determination unit 412 has a 0 signal determination range (first code determination range) in which the detected value can determine that the code of the TCO signal is 0 signal. (S13). In the case of “DCF77”, the 0 signal determination range is set to a range longer than 0 ms and shorter than 125 ms, as shown in FIG. When it is determined YES in S13, the code determination unit 412 determines that the code of the TCO signal is a 0 signal (S14). Then, the code determination unit 412 stores the determination result (0 signal) in the determination result storage unit 413 in association with the second position of the TCO signal to be determined.

  When it is determined NO in S13, the code determination unit 412 determines whether the detected value is included in a one-signal determination range (second code determination range) in which the code of the TCO signal can be determined as one signal (S15). . In the case of “DCF77”, the 1-signal determination range is set to a range longer than 175 ms and shorter than 300 ms, as shown in FIG. When it is determined YES in S15, the code determination unit 412 determines that the code of the TCO signal is one signal (S16). Then, the code determination unit 412 stores the determination result (one signal) in the determination result storage unit 413 in association with the second position of the TCO signal to be determined.

When it is determined NO in S15, the code determination unit 412 determines whether the detection value is included in the boundary range A (a range of 125 ms or more and 175 ms or less) (S17). When it is determined YES in S17, the code determination unit 412 determines the code of the TCO signal based on the internal time (reference data) counted by the time counter 43 (S18). That is, for example, when the standard time is received every day and the internal time is corrected, it is highly possible that the internal time is accurate and coincides with the received signal. For this reason, the code of the TCO signal can be determined based on the internal time.
Specifically, the code determination unit 412 determines the code (0 signal or 1 signal) corresponding to the second position of the converted data obtained by converting the internal time to TC as the code of the TCO signal.

FIG. 8A is a diagram illustrating an example of a detection value and a determination result of the signal width of the TCO signal of the hour data. FIG. 8B is an example of converted data obtained by converting the internal time to TC.
The example of FIG. 8A is an example when a standard radio wave is received at 23:00. In the example of FIG. 8A, the signal width of the TCO signal at the position of 32 seconds (position of BCD (Binary-Coded Decimal) “8” of hour data) and position of 33 seconds (position of BCD “10” of hour data). Since the detected value is included in the 0 signal determination range, the code of the TCO signal is determined to be 0 signal. In addition, the TCO signal at the position of 29 seconds (position of BCD “1” of hour data), position of 30 seconds (position of BCD “2” of hour data), and position of 34 seconds (position of BCD “20” of hour data). Since the detection value of the signal width is included in one signal determination range, the code of the TCO signal is determined to be one signal.
The detection value of the signal width of the signal at the 31-second position (position of BCD “4” of the hour data) is 155 ms and is included in the boundary range A. Therefore, the code of the TCO signal is converted from the internal time converted to TC. Determined based on the data. As shown in FIG. 8B, when the code (BCD) at the 31-second position of the converted data is a 0 signal, the code of the TCO signal is determined to be a 0 signal.

When it is determined NO in S17, the code determination unit 412 determines whether the detected value is 0 ms, that is, the M signal (S19).
When it is determined YES in S19, the code determination unit 412 determines that the code of the TCO signal is the M signal (S20). Then, the code determination unit 412 stores the determination result (M signal) in the determination result storage unit 413 in association with the second position of the TCO signal to be determined.
On the other hand, when it is determined NO in S19, that is, when the detected value is 300 ms or more, since it can be determined that the reliability of the received signal is low, the control unit 47 stops the operation of the receiving circuit unit 3, The reception of the standard radio wave is terminated (S21). Further, the control unit 47 returns to the normal hand movement process (S22) and ends the process.

After the processes of S14, S16, S18, and S20, the code determination unit 412 determines whether a TCO signal for one minute (one frame) is input to the signal width detection unit 411 (S23).
When it is determined NO in S23, the TCO decoding unit 41 returns the process to S12. As a result, every time a TCO signal for 1 bit is input from the binarization circuit 37 to the signal width detector 411 until YES is determined in S23, the processing of S12 to S23 is repeatedly executed.
If it is determined YES in S23, the TC acquisition unit 414 acquires the TC based on the determination result for one minute (60 bits) stored in the determination result storage unit 413, and acquires the acquired TC. Is output to the controller 47 (S24).

  When the TC is input, the control unit 47 stops the operation of the reception circuit unit 3 and ends the reception of the standard radio wave (S25). The time correction unit 471 of the control unit 47 updates the time counter 43 based on the input TC. And the control part 47 corrects the time display in the display part 5 via the drive circuit part 46 (S26). And the control part 47 returns to a normal hand movement process by S22, and complete | finishes a process.

[Effects of First Embodiment]
When the detection value of the signal width detection unit 411 is included in the 0 signal determination range, the code of the TCO signal is determined to be 0 signal, and when the detection value is included in the 1 signal determination range, the code of the TCO signal is 1 signal. It is determined. When the detected value is included in the boundary range A, the code is determined based on the internal time.
For this reason, even when the electric field intensity of the received radio wave is weak and the signal width of the received signal varies due to the influence of noise, the code of the TCO signal can be determined and the reception performance can be improved.
In addition, since the code of the TCO signal is determined, for example, a process of calculating a difference between the detected value of the signal width and the original signal width is not necessary. Further, the process of determining the code of the TCO signal based on the internal time is performed only when the detection value of the signal width is included in the boundary range A. For this reason, the processing load can be reduced.

Since the code of the TCO signal is determined based on the internal time, the code of the TCO signal can be accurately determined when the radio-controlled timepiece 1 receives the standard radio wave and corrects the internal time every day, for example.
In addition, since it is not necessary to receive a plurality of frames of standard radio waves in order to determine the TCO signal code, the TCO signal code can be determined in a short time.

[Second Embodiment]
The radio-controlled timepiece of the second embodiment differs from the radio-controlled timepiece 1 of the first embodiment in that it receives standard radio waves for three frames, and further differs from the radio-controlled timepiece 1 in the method of determining the TCO signal code. Other configurations are the same as those of the radio-controlled timepiece 1.
FIG. 9 is a flowchart showing the time adjustment operation of the radio-controlled timepiece according to the second embodiment.
As shown in FIG. 9, in the time adjustment operation of the second embodiment, the processes of S11 to S17, S19 to S22, S25, S26, and S31 to S36 are executed. Among these, since the process of S11-S17, S19-S22, S25, S26 is the same as that of 1st Embodiment, description is abbreviate | omitted.

In the time correction operation of the second embodiment, if YES is determined in S17, that is, if the detected value is included in the boundary range, the code determination unit 412 determines the TCO signal as a boundary signal (S31). Then, the code determination unit 412 stores the boundary signal in the determination result storage unit 413 in association with the second position of the determination target TCO signal.
In addition, after the processes of S14, S16, S20, and S31, the code determination unit 412 determines whether a TCO signal for 3 minutes (3 frames) has been input to the signal width detection unit 411 (S32). When it is determined NO in S32, the TCO decoding unit 41 returns the process to S12.

If it is determined YES in S32, the code determination unit 412 refers to the determination result storage unit 413 and determines whether there is a boundary signal among the TCO signals for 3 minutes (60 bits × 3) ( S33).
Here, if the code of the TCO signal in another frame is correctly determined, the code of the TCO signal can be specified based on the determination result of the other frame.
For this reason, when it is determined YES in S33, that is, when there is a boundary signal, the code determination unit 412 determines the determination results of two frames different from the frame including the boundary signal, for the boundary signal, Read from the determination result storage unit 413.
Then, the code determination unit 412 determines the code of the boundary signal based on the read determination result. For example, when there is a boundary signal in the first frame, the code determination unit 412 determines the code of the boundary signal of the first frame based on the determination results of the second and third frames.
That is, in the second embodiment, the determination result of the code of the TCO signal for three frames is the reference data of the present invention.
Then, the code determination unit 412 stores the determined result in the determination result storage unit 413 in association with the corresponding frame and second position (S34).

After the process of S34, or when it is determined NO in S33, the TC acquisition unit 414 determines 3 minutes (60 bits × 3) based on the determination result stored in the determination result storage unit 413. The TC for the frame is acquired, and the acquired TC is output to the control unit 47 (S35). In step S25, the control unit 47 ends the reception of the standard radio wave.
And the control part 47 determines whether the consistency of time data can be confirmed between three frames (S36). Specifically, if the time interval of the time data is 1 minute, it is determined that consistency has been confirmed, and if it is not 1 minute, it is determined that consistency cannot be confirmed.
When it is determined YES in S36, the time correction unit 471 of the control unit 47 updates the time counter 43 based on the input TC in S26. And the control part 47 corrects the time display in the display part 5 via the drive circuit part 46, returns to a normal hand movement process by S22, and complete | finishes a process.
If NO is determined in S36, it can be determined that the TC is not accurate. Therefore, the control unit 47 returns to the normal hand movement process in S22 without correcting the time display, and ends the process.

  In the second embodiment, the code of the boundary signal is determined based on the determination result of another frame, but may be determined using the internal time in addition to the determination result.

[Effects of Second Embodiment]
Also in the second embodiment, similarly to the first embodiment, the code of the TCO signal can be determined and the reception performance can be improved even when the electric field strength of the received radio wave is weak. In addition, the processing load can be reduced.
In the second embodiment, since the code of the TCO signal can be determined without using the internal time, the code of the TCO signal can be determined even when the clock does not have the internal time such as after reset.

[Other Embodiments]
The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
In each of the above embodiments, when the detection value of the signal width detection unit 411 is included in the boundary range A, the code determination unit 412 determines that the code of the TCO signal is the original detection signal width of the TCO signal included in the same frame. The determination may be made based on whether the signal width tends to be longer or shorter than the signal width.
For example, when the detection value of the TCO signal at the 31-second position is included in the boundary range A, the detection signal width of the TCO signal included in the same frame tends to be longer than the original signal width. Since the detected value of the TCO signal can be estimated to be a value detected by increasing the signal width of the 0 signal, the code of the TCO signal at the 31-second position is determined as the 0 signal. In addition, when the detection signal width of the TCO signal included in the same frame tends to be shorter than the original signal width, the detection value of the TCO signal at the 31-second position is detected by reducing the signal width of one signal. Therefore, the code of the TCO signal at the 31-second position is determined as one signal.
Whether the detection signal width of the TCO signal included in the frame tends to be longer or shorter than the original signal width is, for example, the detection of the 60-second TCO signal included in the frame. It can be determined by calculating an average value of the signal width and comparing the calculated average value with a threshold value. This calculation process is executed only when the detected value is included in the boundary range A. That is, when the electric field strength of the received radio wave is relatively high, the probability that this calculation process is performed is low.

In the time adjustment operation of the second embodiment, when the standard radio wave is received for 3 minutes and it is determined YES in S32, the number of boundary signals is greater than or equal to a predetermined value (two) at any one of the second positions in the frame. In such a case, the time correction unit 471 does not have to correct the internal time.
For example, if the detection value at the 31-second position is included in the boundary range A in the first frame, included in the 0 signal determination range in the second frame, and included in the boundary range A in the third frame, 31 seconds Since the number of position boundary signals is two or more, the time correction unit 471 does not correct the internal time.
If the number of boundary signals at the same second position is greater than or equal to the predetermined value, it can be determined that the reliability of the received signal is low. In this case, the time is not corrected, and the internal time is corrected with an incorrect code. Can be suppressed.
When the number of boundary signals is 2 or more at any one of the second positions, the reception of the standard radio wave is continued, and the number of boundary signals is 1 or less at all the second positions in the three most recently received frames. In such a case, the time correction unit 471 may correct the internal time.
In addition, when confirming the consistency of time data between four or more frames, the predetermined value may be three or more values.
In addition, when the number of boundary signals included in one frame, two frames, or three frames is equal to or greater than a predetermined value instead of the same second position, the time correction unit 471 does not correct the internal time. May be.

  In each of the embodiments described above, the boundary range A is set around an intermediate value (150 ms) between the original signal width (100 ms) of the 0 signal and the original signal width (200 ms) of the 1 signal. Is not limited to this. For example, the boundary range A may be 135 ms or more and 185 ms or less.

  DESCRIPTION OF SYMBOLS 1 ... Radio wave correction clock, 3 ... Reception circuit part, 4 ... Control circuit part, 41 ... TCO decoding part, 411 ... Signal width detection part, 412 ... Code determination part, 413 ... Determination result storage part, 414 ... TC acquisition part, 43: Time counter, 47: Control unit, 471: Time correction unit, A: Boundary range.

Claims (6)

A receiving unit that receives a standard radio wave and outputs a demodulated signal obtained by demodulating the received signal;
A timekeeping section for measuring the internal time,
A signal width detector for detecting a signal width of the demodulated signal;
A code determination unit that determines a code of the demodulated signal based on a detection value of the signal width detection unit;
A time correction unit for correcting the internal time based on the code determined by the code determination unit,
The code determination unit
When the detection value is included in a specific code determination range preset as a range in which code determination based on the signal width is possible, the code of the demodulated signal is determined as a code corresponding to the specific code determination range;
The code of the demodulated signal is determined based on reference data when the detection value is included in an unspecified code determination range set in advance as a range in which code determination based on the signal width is not possible. A radio correction watch. The radio-controlled timepiece according to claim 1,
The specific code determination range includes a first code determination range in which a code of the demodulated signal can be determined as a first code, and a second code determination range in which a code of the demodulated signal can be determined as a second code,
The radio-controlled timepiece, wherein the unspecified code determination range is set between the first code determination range and the second code determination range. In the radio-controlled timepiece according to claim 1 or 2,
The reference data is the internal time,
When the detected value is included in the unspecified code determination range, the code determination unit determines the code of the demodulated signal based on the internal time. The radio-controlled timepiece according to any one of claims 1 to 3,
The receiving unit receives a plurality of frames of the standard radio wave,
The code determination unit determines a code of the demodulated signal of the plurality of frames,
The reference data is a determination result of a code of the demodulated signal of the plurality of frames,
When the detected value is included in the unspecified code determination range, the code determination unit determines a code of a demodulated signal based on the determination result. The radio-controlled timepiece according to any one of claims 1 to 4,
The receiving unit receives a predetermined number of frames of one or more frames of the standard radio wave;
The code determination unit determines a code of the demodulated signal of the predetermined number of frames,
As a result of determination by the code determination unit, when the number of demodulated signals whose detection value is included in the unspecified code determination range among the demodulation signals of the predetermined number of frames is equal to or greater than a predetermined value, the time The correction unit does not correct the internal time based on the code determined by the code determination unit. A time correction method for a radio-controlled timepiece comprising a receiving unit that receives a standard radio wave and outputs a demodulated signal obtained by demodulating the received signal, and a time measuring unit that measures the internal time,
A signal width detection step of detecting a signal width of the demodulated signal; and
A code determination step for determining a code of the demodulated signal based on the detection value detected in the signal width detection step;
A time correction step of correcting the internal time based on the code determined in the code determination step,
The code determination step includes
When the detection value is included in a specific code determination range preset as a range in which code determination based on the signal width is possible, the code of the demodulated signal is determined as a code corresponding to the specific code determination range;
The code of the demodulated signal is determined based on reference data when the detection value is included in an unspecified code determination range set in advance as a range in which code determination based on the signal width is not possible. How to correct the time of the radio correction clock.

Images