JP2016212018A - Radio wave receiving device and radio wave-controlled timepiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio wave receiving device capable of improving accuracy of determination of a code of a reception signal, and a radio wave -controlled timepiece.SOLUTION: A radio wave receiving device comprises: a reception section for receiving a standard radio wave and outputting a binary signal obtained by binarizing a reception signal; a signal width detection section 414 for detecting a signal width of the binary signal; a threshold adjustment section (adjustment value calculation section 416 and threshold setting section 417) for adjusting a determination threshold used for code determination of the binary signal; and a code determination section 418 for comparing a detection value of the signal width detection section 414 with the adjusted determination threshold and determining a code of the binary signal. The threshold adjustment section adjusts the determination threshold on the basis of a variation of the detection value of the signal width of the binary signal corresponding to a second to which a marker signal is pre-assigned from a theoretical value of a signal width of the marker signal.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a radio wave receiver and a radio wave correction watch that receive standard radio waves.

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 disclosed in Patent Literature 1 compares the signal width of the received signal with a threshold value to determine the codes “1”, “0”, and “marker”, and acquires time data based on the determined code. doing.

JP 2011-214871 A

  However, in the radio-controlled timepiece of Patent Document 1, if the electric field strength of the received radio wave is weak due to the surrounding environment, radio wave transmission conditions, etc., the signal width of the received signal deviates from the theoretical value. May be misjudged.

  An object of the present invention is to provide a radio wave receiver and a radio wave correction watch that can improve the accuracy of determining a code of a received signal.

  The radio wave receiving apparatus of the present invention includes a receiving unit that receives a standard radio wave and outputs a binarized signal obtained by binarizing the received signal, a signal width detecting unit that detects a signal width of the binarized signal, A threshold adjustment unit for adjusting a determination threshold used for code determination of the binarized signal and a detection value of the signal width detection unit are compared with the adjusted determination threshold to determine the code of the binarized signal A code determination unit, wherein the threshold adjustment unit has a specific signal detection signal width that is a detection value of a signal width of a binarized signal corresponding to a second in which the specific signal is assigned in advance. The determination threshold value is adjusted based on the amount of change from the theoretical value of the signal width.

According to the present invention, every time the receiving unit receives the standard radio wave and outputs the binarized signal, the signal width detecting unit detects the signal width of the binarized signal. The threshold adjustment unit is a theoretical value of the signal width of the specific signal of the specific signal detection signal width that is a detection value of the signal width of the binarized signal corresponding to the second in which a specific signal such as a marker signal is assigned in advance. The determination threshold is adjusted based on the amount of change from. Then, the code determination unit determines the code of the binarized signal by comparing the detection value of the signal width detection unit with the adjusted determination threshold value.
By detecting the amount of change from the theoretical value of the specific signal with respect to the specific signal detection signal width, the amount of change from the theoretical value of the signal width of the binarized signal output from the receiver is based on the actual measurement value. Can be detected. For this reason, by adjusting the determination threshold based on the amount of change, the code of the binarized signal can be correctly determined even when the electric field strength of the received radio wave is weak and the signal width of the binarized signal deviates from the theoretical value. The accuracy of code determination can be improved.

  In the radio wave receiver according to the aspect of the invention, it is preferable that the change amount is a difference between the specific signal detection signal width and the theoretical value.

  The average value of the difference from the theoretical value of the signal width of the binarized signal is about the same for a specific signal such as a marker signal, a 1 signal indicating a binary number “1”, and a 0 signal indicating a binary number “0”. In the case of the receiving unit having the following characteristic, the code (1, 0) of the binarized signal can be correctly determined by adjusting the determination threshold based on the difference between the specific signal detection signal width and the theoretical value.

  In the radio wave receiver of the present invention, it is preferable that the amount of change is a ratio of the specific signal detection signal width to the theoretical value.

  In the case of a receiver having the characteristic that the average value of the ratio of the signal width of the binarized signal to the theoretical value is the same for a specific signal such as a marker signal, 1 signal, and 0 signal, the theory of the specific signal detection signal width By adjusting the determination threshold based on the ratio to the value, the code (1, 0) of the binarized signal can be correctly determined.

  In the radio wave receiver of the present invention, the threshold adjustment unit detects the specific signal detection signal detected each time the reception unit outputs a binarized signal corresponding to a second to which the specific signal is assigned in advance. It is preferable to adjust the determination threshold based on the change amount of the width.

According to the present invention, when the receiving unit outputs a binarized signal corresponding to a second in which a specific signal is pre-assigned, the threshold adjustment unit is configured based on the change amount of the detected specific signal detection signal width. Adjust the determination threshold. Then, the code determination unit compares the detection value of the signal width detection unit with the adjusted determination threshold value until the reception unit outputs a binarized signal corresponding to the next second to which a specific signal is assigned in advance. Then, the code of the binarized signal is determined. These processes are performed each time the receiving unit outputs a binarized signal corresponding to a second to which a specific signal is assigned in advance.
According to this, since the code of the binarized signal can be determined with the adjusted determination threshold from the first minute, it is possible to improve the possibility that an accurate time code can be acquired early.

  In the radio wave receiver of the present invention, the threshold adjustment unit is configured to change the amount of change in the specific signal detection signal width detected at least for one minute each time the reception unit outputs a binarized signal for one minute. It is preferable to adjust the determination threshold based on the average value.

According to the present invention, when the receiving unit receives a standard radio wave for one minute and outputs a binarized signal for one minute, the threshold adjusting unit changes the specific signal detection signal width detected at least for the one minute. The determination threshold is adjusted based on the average amount. The code determination unit determines the code of the binarized signal by comparing the detection value of the signal width detection unit for the binarized signal for the next one minute with the adjusted determination threshold value.
According to the present invention, the determination threshold value is adjusted at intervals of 1 minute, so that the adjustment frequency can be reduced and the determination threshold value can be adjusted compared to the case where the determination threshold value is adjusted each time a specific signal such as a marker signal is received. Can reduce the processing load.
In addition, since the determination threshold is set based on the average value of the change amounts, when noise is included in a specific signal, the influence of noise on the adjustment of the determination threshold can be reduced. Therefore, it is possible to reduce the possibility that the code of the binarized signal is erroneously determined due to the influence of noise.

  The radio wave receiver of the present invention includes a detection value storage unit for storing data, the signal width detection unit stores the detection value in the detection value storage unit, and the threshold adjustment unit is binarized for one minute. Each time the reception unit outputs a signal, the determination threshold is adjusted based on an average value of the change amount of the specific signal detection signal width detected at least for one minute, and the code determination unit It is preferable to determine the code of the binarized signal for one minute by comparing the detection value stored in the detection value storage unit for one minute with the adjusted determination threshold.

According to the present invention, the signal width detection unit stores the detection value in the detection value storage unit every time the signal width is detected. Then, when the receiving unit receives the standard radio wave for 1 minute and outputs the binarized signal for 1 minute, the threshold value adjusting unit is the average value of the change amount of the specific signal detection signal width detected at least in the 1 minute The determination threshold is adjusted based on the above. The code determination unit determines the code of the binarized signal for the one minute by comparing with a determination threshold value obtained by adjusting the detection value stored in the detection value storage unit for the one minute.
According to this, the determination threshold value compared with the binarized signal for one minute is adjusted based on the change amount of the specific signal detection signal width detected in the same one minute. That is, since the determination threshold value compared with the binarized signal for one minute can be adjusted based on the amount of change in the specific signal detection signal width detected in the same reception environment, for example, the determination threshold value can be set in another one minute. Compared to the case of adjusting based on the detected change amount of the specific signal detection signal width, the code of the binarized signal can be determined more correctly.
Further, since the adjustment of the determination threshold is performed at 1 minute intervals, for example, the adjustment frequency can be reduced and the processing load for adjusting the determination threshold can be reduced as compared with the case where it is performed every time a specific signal is received.
Further, since the determination threshold is set based on the average value of the change amounts, it is possible to reduce the possibility that the code of the binarized signal is erroneously determined due to the influence of noise.

  A radio-controlled timepiece according to the present invention includes the radio wave receiving device, a time measuring unit that measures an internal time, and a time correcting unit that corrects the internal time based on a code determined by the radio wave receiving device. Features.

  According to the present invention, even when the electric field strength of the received radio wave is weak and the signal width of the binarized signal deviates from the theoretical value, the accuracy of code determination can be improved, so the probability of successfully correcting the internal time is improved. it can.

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 time code format of the standard radio wave "JJY" in Japan. It is a figure which shows the receiving pulse duty with respect to each signal of "JJY", and an amplitude change. It is a block diagram which shows the structure of the TCO decoding part in 1st Embodiment. It is a flowchart which shows the time correction operation | movement in 1st Embodiment. It is a flowchart which shows the TC acquisition process in 1st Embodiment. It is a flowchart which shows the code | cord | chord determination process in 1st Embodiment. It is a block diagram which shows the structure of the TCO decoding part which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the TC acquisition process in 2nd Embodiment. It is a flowchart which shows the TC acquisition process which concerns on 3rd 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. Based on the signal width (or duty) of the high-level signal or low-level signal, 1 signal indicating binary “1”, 0 signal indicating binary “0”, and markers (P, M) are indicated. The P signal is determined.

  The receiving circuit unit 3 demodulates the received signal of the standard radio wave received by the antenna 2 and outputs it 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 (internal 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, a binarization circuit 37, and a decoding circuit 38. Here, the receiving circuit unit 3 is an example of 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.

[Time code format]
Here, the time information (time code) is configured in accordance with a predetermined time information format (time code format) for each country.
For example, in the time code format of the Japanese standard radio wave “JJY” shown in FIG. 2, one signal is transmitted every second, and is configured as one record (one frame) in 60 seconds. That is, one frame is 60-bit data. The data items include the minute of the current time, the hour, the day of the current year since January 1, the year (the last two digits of the year), the day of the week, and “leap second”. The value of each item is composed of a combination of numerical values assigned every second (each bit), and this combination is determined from the type of signal. Here, “M” in FIG. 2 is a marker corresponding to the minute (0 seconds per minute), and “P1 to P5” is a position marker whose position is determined in advance. Signal. That is, “M” and “P1 to P5” are marker signals.

  As shown in FIG. 3, in “JJY”, in each item of the time code format, 1 signal is a signal having a pulse width of about 0.5 seconds (500 msec), and 0 signal is about 0.8 seconds (800 msec). A P signal indicating a pulse width and indicating each marker is a signal having a pulse width of approximately 0.2 seconds (200 msec).

  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.

  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.
The control circuit unit 4 sets the time (internal time) of the time counter 43 based on the TC acquired 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 sampling unit 411, a second synchronization detection unit 412, a 0 second position detection unit 413, a signal width detection unit 414, a difference storage unit 415, and an adjustment value calculation unit. 416, a threshold setting unit 417, a code determination unit 418, and a code storage unit 419.
Here, the TCO decoding unit 41 and the receiving circuit unit 3 constitute a radio wave receiving apparatus of the present invention. Further, the adjustment value calculation unit 416 and the threshold setting unit 417 constitute a threshold adjustment unit of the present invention.

The sampling unit 411 samples the input TCO signal. The second synchronization detection unit 412 performs second synchronization processing on the input TCO signal. The 0 second position detection unit 413 detects the 0 second position with respect to the input TCO signal. The signal width detection unit 414 detects the signal width of the input TCO signal. The difference storage unit 415 stores the difference between the detection value of the signal width detection unit 414 of the marker signal and the theoretical value. The adjustment value calculation unit 416 calculates an adjustment value for adjusting a determination threshold value used for code determination of the TCO signal. The threshold setting unit 417 sets a determination threshold based on the calculated adjustment value. The code determination unit 418 determines the code of the TCO signal by comparing the detection value of the signal width detection unit 414 with a determination threshold value. The code storage unit 419 stores the determination result (code value) determined by the code determination unit 418.
The details of 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 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, and the time correction unit 471 performs control to correct the count of the time counter 43 based on the TC input from the TCO decoding unit 41.

  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. .

[Operation of the radio-controlled clock]
Next, the time correction operation using the standard radio wave of the radio correction watch 1 will be described.
As shown in FIG. 5, the control unit 47 of the radio-controlled timepiece 1 receives the reception circuit when a regular reception time is reached or when a forced reception operation is performed by operating the external operation member 6 such as a button. The unit 3 is operated, and the receiving circuit unit 3 starts receiving the standard radio wave via the antenna 2 (S1).
Note that the type of the standard radio wave to be received is set as the initial value of the previously received standard radio wave, but the user can also select the standard radio wave by operating the external operation member 6.
Here, as an example, a time adjustment operation when “JJY” is received will be described.

When the receiving circuit unit 3 starts receiving standard radio waves, the binarization circuit 37 sequentially outputs TCO signals. Further, the TCO decoding unit 41 initializes the difference storage unit 415 that stores the difference between the detection value of the signal width detection unit 414 and the theoretical value and the code storage unit 419 that stores the code determination result, and erases the data (S2). ).
The sampling unit 411 samples the TCO signal output from the binarization circuit 37 at a frequency of 64 Hz (S3).
The second synchronization detection unit 412 executes the second synchronization process S4. Specifically, the second synchronization detection unit 412 detects the rising timing interval of the TCO signal based on the sampling result, and determines that the second synchronization is completed when the interval becomes one second interval.

When determining that the second synchronization is not completed in S5 (NO in S5), the second synchronization detection unit 412 determines whether a predetermined time (specifically, 5 minutes) has elapsed from the start of reception (S6).
If the second synchronization detection unit 412 determines NO in S6, it continues the second synchronization processing S4. If YES is determined in S6, the control unit 47 ends the operation of the receiving circuit unit 3 because the standard radio wave is not received or the radio wave intensity is weak even though it is received. The reception is terminated (S7). And the control part 47 complete | finishes time correction operation | movement.

When the second synchronization is completed and it is determined YES in S5, the sampling unit 411 determines, for example, a timing 50 msec before the second synchronization timing as the sampling start position (S8).
Next, the 0-second position detection unit 413 acquires a marker signal indicating the 0-second position of the time code and performs a process (minute synchronization process) for determining the 0-second position. For example, in JJY, the portion where the marker signal continues is the 0 second position, and the 0 second position can be determined by detecting this continuous marker signal.
Then, the 0-second position detection unit 413 determines whether the 0-second position has been confirmed (S9). When it is determined NO in S9, in S6, the 0-second position detection unit 413 determines whether a predetermined time (specifically, 5 minutes) has elapsed from the start of reception.
And the 0 second position detection part 413 returns a process to S4, when it determines with NO by S6. That is, the second synchronization process S4 and the process for determining the 0-second position are continued until YES is determined in S9 or S6. Note that the 0-second position detection unit 413 may return NO to S9 if NO is determined in S9 and NO is determined in S6.

If the 0-second position is confirmed and YES is determined in S9, the TCO decoding unit 41 executes the TC acquisition process S20.
FIG. 6 is a flowchart showing the TC acquisition process S20.
When the TC acquisition process S20 is started, the signal width detection unit 414 detects the signal width of the TCO signal output from the binarization circuit 37 based on the sampling result (S21).
Next, the adjustment value calculation unit 416 determines whether the TCO signal whose signal width has been detected in S21 is a signal of a second (transmission timing) to which a marker signal is assigned in advance in the time code format, and determines whether it is a marker signal. (S22). For example, in the case of “JJY”, the seconds to which the marker signal is assigned are 0 seconds, 9 seconds, 19 seconds, 29 seconds, 39 seconds, 49 seconds, and 59 seconds. Here, the marker signal is an example of a specific signal of the present invention.

When it is determined YES in S22, the adjustment value calculation unit 416 differs from the detection value detected in S21 with the theoretical value of the signal width of the marker signal (200 msec in the case of “JJY”) (detection value). -Theoretical value) is calculated (S23). Here, the detection value detected in S21 is an example of the specific signal detection signal width of the present invention.
For example, when the detection value is 170 msec, the difference is −30 msec (170 msec−200 msec). Here, the difference is an example of a change amount of the present invention.
Next, the adjustment value calculation unit 416 reads the difference calculated so far stored in the difference storage unit 415 (S24). Initially, since there is no difference stored in the difference storage unit 415, there is no difference to be read.
Next, the adjustment value calculation unit 416 calculates the average value of the difference calculated in S23 and the difference read in S24, thereby determining a determination threshold (first determination threshold and An adjustment value for adjusting the second determination threshold value is calculated (S25). Then, the adjustment value calculation unit 416 stores the difference calculated in S23 in the difference storage unit 415 (S26).

Then, the threshold setting unit 417 sets (adjusts) the determination threshold by adding the average value calculated in S25 to the initial value of the determination threshold (S27). In the case of “JJY”, the initial value of the first determination threshold is set to 350 msec, which is an intermediate value between 200 msec, which is the theoretical value of the signal width of the marker signal, and 500 msec, which is the theoretical value of the signal width of one signal. Has been. The initial value of the second determination threshold is set to 650 msec, which is an intermediate value between 500 msec, which is the theoretical value of the signal width of 1 signal, and 800 msec, which is the theoretical value of the signal width of 0 signal.
For example, when the average value calculated in S25 is −30 msec, the first determination threshold is set to 320 msec (350 msec−30 msec), and the second determination threshold is set to 620 msec (650 msec−30 msec).

After the process of S27, or when it is determined NO in S22, the code determination unit 418 executes a code determination process S40.
FIG. 7 is a flowchart showing the code determination process S40.
When the code determination process S40 is executed, the code determination unit 418 determines whether the detection value detected in S21 is greater than or equal to the first determination threshold set in S27 and less than the second determination threshold (S41). When it is determined YES in S41, the code determination unit 418 determines that the code of the TCO signal is “1” (S42).
On the other hand, when it is determined NO in S41, the code determination unit 418 determines whether the detected value is equal to or greater than the second determination threshold set in S27 (S43). When it is determined YES in S43, the code determination unit 418 determines that the code of the TCO signal is “0” (S44).
If NO is determined in S43, the code determining unit 418 determines that the code of the TCO signal is “P” (marker) (S45).
After the processes of S42, S44, and S45, the code determination unit 418 stores the determination result (code value) in the code storage unit 419 (S46). Then, the code determination unit 418 ends the code determination process S40.

When the code determination process S40 ends, as shown in FIG. 6, the TCO decoding unit 41 determines whether the code values for 60 seconds are stored in the code storage unit 419 (S28).
When it is determined NO in S28, the TCO decoding unit 41 returns the process to S21.
That is, the TCO decoding unit 41 repeatedly executes the processes of S21 to S27, S40, and S28 until it is determined YES in S28.
That is, until the TCO signal of the next marker signal is output from the binarization circuit 37, it is determined NO in S22. Therefore, the determination threshold value is not changed, and the signal width detection and code determination processing in S21 are performed. S40 is repeatedly executed.
Then, when the TCO signal of the next marker signal is output, YES is determined in S22, and the adjustment value calculation unit 416 calculates the difference in S23, reads the previous difference in S24, and averages the difference in S25. The value is calculated, and the difference calculated in S26 is stored in the difference storage unit 415. In step S27, the threshold setting unit 417 adjusts the determination threshold by adding the calculated average value to the initial value of the determination threshold.
Then, the code determination process S40 is performed with the adjusted determination threshold until the TCO signal of the next marker signal is output.

As described above, when the first (first) marker signal is received, the adjustment value calculation unit 416 uses the difference between the detected value of the first marker signal and the theoretical value as the adjustment value. When the second marker signal is received, the average value of the differences between the detected values of the first and second marker signals and the theoretical value is used as the adjustment value. When the third marker signal is received, the average value of the difference between the detected value of the first, second, and third marker signals and the theoretical value is adjusted. For example, when the detection values of the first, second, and third marker signals are 180 msec, 160 msec, and 170 msec, the difference from the theoretical value is −20 msec, −40 msec, and −30 msec, respectively, and the adjustment value Is -30 msec, which is the average of these values.
The adjustment value calculation unit 416 calculates the adjustment value in the same manner when the fourth and subsequent marker signals are received.

  The code value for 60 seconds is stored in the code storage unit 419, and if it is determined YES in S28, the TCO decoding unit 41 acquires the TC based on the code value stored in the code storage unit 419 and acquires the TC. The TC is output to the control unit 47. Then, the TCO decoding unit 41 ends the TC acquisition process S20.

When the TC acquisition process S20 ends, as shown in FIG. 5, the control unit 47 determines whether the consistency of time data can be confirmed among three frames of the TC output from the TCO decoding unit 41. (S10). Specifically, if the time intervals of the three time data are 1 minute intervals, it is determined that the consistency is confirmed, and if the time intervals are not 1 minute intervals, it is determined that the consistency cannot be confirmed.
Initially, since there is only time data for one frame, NO is determined in S10. Then, the control unit 47 determines whether 8 minutes have elapsed since the start of reception (S11). When it is determined YES in S11, it may be the case that the standard radio wave is not received or the radio wave intensity is weak even though it is received. Therefore, the control unit 47 ends the operation of the receiving circuit unit 3, Reception is terminated (S12). And the control part 47 complete | finishes time correction operation | movement.

On the other hand, when it determines with NO by S11, the control part 47 advances a process to S20. In other words, the TC acquisition process S20 is repeatedly executed until YES is determined in S10 or YES is determined in S11, and TC is output to the control unit 47 each time the TC acquisition process S20 is executed.
If the consistency of the time data can be confirmed between the three frames and it is determined YES in S10, the control unit 47 ends the operation of the receiving circuit unit 3 and ends the reception (S13).
Then, the time correction unit 471 corrects the count (internal time) of the time counter 43 based on the time data (S14). And the control part 47 complete | finishes time correction operation | movement.

In “WWVB”, in the time code format, the marker signal is assigned to 0 seconds, 9 seconds, 19 seconds, 29 seconds, 39 seconds, 49 seconds, and 59 seconds. An adjustment value is calculated by calculating a difference between the detected value of the TCO signal corresponding to these seconds and the theoretical value (800 msec) of the marker signal, and a determination threshold value is set.
In “DCF77”, since the marker signal is assigned to 0 second in the time code format, the adjustment value calculation unit 416 detects the detected value of the TCO signal corresponding to 0 second and the theoretical value ( 100 msec), an adjustment value is calculated, and a determination threshold value is set.

[Effects of First Embodiment]
When the reception circuit unit 3 has a characteristic that the average value of the difference from the theoretical value of the signal width of the binarized signal is approximately the same for the marker signal, 1 signal, and 0 signal, the detected value of the signal width of the marker signal On the other hand, by calculating the difference from the theoretical value of the marker signal, the difference from the theoretical value of the signal width of the binarized signal of the 1 signal and 0 signal output from the receiving circuit unit 3 is obtained as an actual measurement value. Can be detected based on. For this reason, by adjusting the determination threshold based on the calculated difference, even when the electric field strength of the received radio wave is weak and the signal width of the binarized signal deviates from the theoretical value, the binarized signal of 1 signal and 0 signal Can be determined correctly, and the accuracy of code determination can be improved.

  Since the determination threshold is set based on the average value of the calculated differences, when noise is included in the marker signal, the influence of noise on the adjustment of the determination threshold can be reduced. Therefore, it is possible to reduce the possibility that the code of the binarized signal is erroneously determined due to the influence of noise.

  Since one of the marker signals is assigned to the 0 second position, by adjusting the determination threshold at the timing when the marker signal is received, the code of the TCO signal is adjusted with the adjusted determination threshold immediately after the reception is started. Can be judged. For this reason, it is possible to improve the possibility that an accurate TC can be acquired early.

[Second Embodiment]
The radio wave correction timepiece 1 of the first embodiment sets a determination threshold every time a marker signal is received, but the radio wave correction timepiece of the second embodiment sets a determination threshold every minute. For this reason, the configuration of the TCO decoding unit 41A of the second embodiment and the TC acquisition process S20A performed by the TCO decoding unit 41A are different from the TCO decoding unit 41 and the TC acquisition process S20 of the first embodiment. Other configurations are the same as those in the first embodiment.

As illustrated in FIG. 8, the TCO decoding unit 41A includes a detection value storage unit 420 that stores the detection value of the signal width detection unit 414 in addition to the functional units of the TCO decoding unit 41 of the first embodiment. The data stored in the detected value storage unit 420 is initialized and erased by the initialization process S2.
When the TCO decoding unit 41A executes the TC acquisition process S20A, as shown in FIG. 9, the signal width of the TCO signal is detected in S21, and it is determined whether it is a marker signal in S22.
When it is determined YES in S22, the signal width detection unit 414 stores the detection value detected in S21 in the detection value storage unit 420 (S31).
After the process of S31 or when it is determined NO in S22, the code determination unit 418 executes the code determination process S40.
After the process of S40, the TCO decoding unit 41A determines whether the code values for 60 seconds are stored in the code storage unit 419 (S28).
When it is determined NO in S28, the TCO decoding unit 41 returns the process to S21. And until it determines with YES by S28, the process of S21, S22, S31, S40, S28 is repeatedly performed.
Note that the determination threshold value is not set for the first minute, and the code determination process S40 is executed based on the initial value of the determination threshold value.

On the other hand, when it is determined YES in S28, the adjustment value calculation unit 416 reads the detection value stored in the detection value storage unit 420 (S32). At the stage where the first minute has passed, the detection value storage unit 420 stores the detection values of the marker signals detected in one minute, and these detection values are read in S32.
Next, in S23, the adjustment value calculation unit 416 calculates the difference between the detection value read in S32 and the theoretical value of the signal width of the marker signal.
Then, in S25, the adjustment value calculation unit 416 calculates an adjustment value for adjusting the determination threshold by calculating the average value of the differences calculated in S23.
In S27, the threshold setting unit 417 sets (adjusts) the determination threshold by adding the average value calculated in S25 to the initial value of the determination threshold. Then, the TCO decoding unit 41 ends the TC acquisition process S20A.

As a result, in the next one minute (second one minute), the code determination process S40 is executed based on the determination threshold set in S27.
In addition, in the second one minute, when it is determined YES in S28, the detection value storage unit 420 stores the detection value of the marker signal detected in two minutes, but the adjustment value calculation unit 416 Then, only the detection value for the immediately preceding 1 minute (second 1 minute) is read from the detection value storage unit 420. Then, the adjustment value calculation unit 416 calculates an adjustment value based on the read detection value, and the threshold value setting unit 417 sets a determination threshold value based on the calculated adjustment value.
The code determination process S40 and the determination threshold value are set in the same manner in the first minute after the third time.

[Effects of Second Embodiment]
Also in the second embodiment, the same function and effect can be obtained with the same configuration as in the first embodiment.
Furthermore, since the determination threshold value is set at 1-minute intervals, the adjustment frequency can be reduced and the processing load for setting the determination threshold value can be reduced as compared with the case where the determination threshold value is set each time a marker signal is received.
In addition, since the determination threshold is set based on the average value of the calculated differences for one minute, when noise is included in the marker signal, the influence of noise on the adjustment of the determination threshold can be reduced. Therefore, it is possible to reduce the possibility that the code of the binarized signal is erroneously determined due to the influence of noise.

[Third Embodiment]
In the radio-controlled timepiece according to the second embodiment, a determination threshold is set every minute, and the code determination process S40 is performed on the received signal received in the next one minute with the set determination threshold. The radio-controlled timepiece of the embodiment performs a code determination process S40 on the received signal received in the immediately preceding minute with a determination threshold set every minute. For this reason, the TC acquisition process S20B of the third embodiment is different from the TC acquisition process S20A of the second embodiment. Other configurations are the same as those of the second embodiment.

As shown in FIG. 10, when the TC acquisition process S20B is executed, the signal width of the TCO signal is detected in S21.
Then, the signal width detection unit 414 stores the detection value detected in S21 in the detection value storage unit 420 in association with the corresponding second in the time code format (S31B).
Next, the TCO decoding unit 41A determines whether the detection values for 60 seconds are stored in the detection value storage unit 420 (S51).
When it is determined NO in S51, the TCO decoding unit 41A returns the process to S21. Then, the processes of S21, S31B, and S51 are repeatedly executed.

Then, the detected value of the TCO signal for 60 seconds is stored in the detected value storage unit 420, and when it is determined YES in S51, the adjustment value calculating unit 416 stores the detected value stored in the detected value storage unit 420. Of these, only the detection value corresponding to the second to which the marker signal is assigned is read (S32B).
In S23, the adjustment value calculation unit 416 calculates the difference between the detection value read in S32B and the theoretical value of the signal width of the marker signal.
Then, in S25, the adjustment value calculation unit 416 calculates an adjustment value for adjusting the determination threshold by calculating the average value of the differences calculated in S23.
In S27, the threshold setting unit 417 sets (adjusts) the determination threshold by adding the average value calculated in S25 to the initial value of the determination threshold.

Next, the code determination unit 418 reads one detection value for the last 60 seconds stored in the detection value storage unit 420 in order from 0 seconds (S52).
Then, the code determination unit 418 executes a code determination process S40 based on the detection value read in S52.
After the process of S40, the TCO decoding unit 41A determines whether the code values for 60 seconds are stored in the code storage unit 419 (S28).
When it is determined NO in S28, the TCO decoding unit 41A returns the process to S52. And the process of S52, S40, S28 is repeatedly performed. Thereby, the code determination process S40 is executed for all the detected values for the immediately preceding 60 seconds.
Then, the code values for 60 seconds are stored in the code storage unit 419, and if YES is determined in S28, the TCO decoding unit 41 ends the TC acquisition process S20B.
In addition, while performing the processing of S52, S40, and S28, the processing of S21, S31B, and S51 may be performed on the TCO signal for the next one minute in parallel.

In addition, in the second one minute, when it is determined YES in S51, the detection value storage unit 420 stores the detection value detected for two minutes, but the adjustment value calculation unit 416 Only the detected value of the marker signal for the previous minute (second minute) is read from the storage unit 420. Then, the adjustment value calculation unit 416 calculates an adjustment value based on the read detection value, and the threshold value setting unit 417 sets a determination threshold value based on the calculated adjustment value. Based on the set determination threshold, the code determination process S40 is performed on the second one-minute TCO signal.
The determination threshold value setting and the code determination process S40 are performed in the same manner also for 1 minute after the third time.

[Effects of Third Embodiment]
In the third embodiment, the same function and effect can be obtained with the same configuration as in the second embodiment.
Furthermore, the determination threshold value to be compared with the binarized signal for 1 minute is adjusted based on the difference from the theoretical value of the detected value of the marker signal detected in the same 1 minute. That is, since the determination threshold value to be compared with the binarized signal for 1 minute can be adjusted based on the difference of the marker signal detected in the same reception environment, for example, the marker for which the determination threshold value is detected in another one minute Compared with the case of adjusting based on the difference between the signals, the code of the binarized signal can be determined more correctly.
In addition, since the code of the TCO signal can be determined based on the determination threshold adjusted from the first minute, the possibility that an accurate time code can be acquired early can be improved.

[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, the adjustment value calculation unit 416 calculates the adjustment value based on the detection value of the signal width of the marker signal, but the present invention is not limited to this. For example, in “JJY” and “WWVB”, a fixed signal previously assigned to 4 seconds, 10 seconds, 11 seconds, 14 seconds, etc. in the time code format, or in “DCF77”, 1 second to 14 seconds in the time code format. The adjustment value may be calculated based on the detection value of the signal width of the extension signal assigned in advance.

In each of the above embodiments, the adjustment value calculation unit 416 calculates the adjustment value by calculating the average value of the difference between the detection value of the signal width of the marker signal and the theoretical value, but the present invention is not limited to this. Not. For example, the adjustment value may be calculated by calculating the average value of the ratio of the detected value to the theoretical value. For example, in “JJY”, when the detected value of the marker signal is 180 msec, the ratio is 0.9 (180 msec / 200 msec).
In this case, the threshold setting unit 417 sets the determination threshold by multiplying the initial value of the determination threshold by the adjustment value. For example, in “JJY”, when the average value of the ratio is 0.9, the first determination threshold is 315 msec (350 msec × 0.9), and the second determination threshold is 585 msec (650 × 0.9). It becomes.

  In the first embodiment, the adjustment value calculation unit 416 calculates the difference between the detection value and the theoretical value every time the signal width of the marker signal is detected, and calculates the difference between the calculated difference and the average of the difference calculated up to the previous time. The adjustment value is calculated by calculating the value, but the present invention is not limited to this. For example, the calculated difference may be used as an adjustment value as it is.

  In the second and third embodiments, the adjustment value calculation unit 416 calculates the adjustment value based on the detection value of the signal width of the marker signal for the last minute, but the present invention is not limited to this. For example, the adjustment value may be calculated based on the detection values of the signal widths of all marker signals received after the start of reception.

  In the second embodiment, the code determination process S40 may not be performed for the first one minute TCO signal.

  In each of the above embodiments, in S10, the control unit 47 determines whether the consistency of time data can be confirmed between three frames in the TC output from the TCO decoding unit 41. Is not limited to this. For example, you may determine whether consistency can be confirmed between TC and internal time.

  DESCRIPTION OF SYMBOLS 1 ... Radio wave correction clock, 3 ... Reception circuit part, 37 ... Binarization circuit, 4 ... Control circuit part, 41 ... TCO decoding part, 411 ... Sampling part, 412 ... Second synchronization detection part, 413 ... Second position detection part, 414: Signal width detection unit, 415 ... Difference storage unit, 416 ... Adjustment value calculation unit, 417 ... Threshold setting unit, 418 ... Code determination unit, 419 ... Code storage unit, 420 ... Detection value storage unit, 43 ... Time counter, 47: Control unit, 471: Time correction unit.

Claims (7)

A receiving unit that receives a standard radio wave and outputs a binarized signal obtained by binarizing the received signal;
A signal width detector for detecting a signal width of the binarized signal;
A threshold adjustment unit for adjusting a determination threshold used for code determination of the binarized signal;
A code determination unit that compares the detection value of the signal width detection unit with the adjusted determination threshold and determines the code of the binarized signal;
The threshold adjustment unit is configured to obtain a specific signal detection signal width, which is a detection value of a signal width of a binarized signal corresponding to a second in which a specific signal is assigned in advance, from a theoretical value of the signal width of the specific signal. The radio wave receiving apparatus, wherein the determination threshold is adjusted based on a change amount. The radio wave receiver according to claim 1,
The amount of change is a difference between the specific signal detection signal width and the theoretical value. The radio wave receiver according to claim 1,
The amount of change is a ratio of the specific signal detection signal width to the theoretical value. In the radio wave receiver according to any one of claims 1 to 3,
The threshold adjustment unit is based on the detected change amount of the specific signal detection signal width every time the reception unit outputs a binarized signal corresponding to a second in which the specific signal is assigned in advance. The radio wave receiver characterized by adjusting the determination threshold. In the radio wave receiver according to any one of claims 1 to 3,
The threshold adjustment unit performs the determination based on an average value of the change amounts of the specific signal detection signal width detected at least in the one minute each time the reception unit outputs a binarized signal for one minute. A radio wave receiver characterized by adjusting a threshold value. In the radio wave receiver according to any one of claims 1 to 3,
A detection value storage unit for storing data;
The signal width detection unit stores a detection value in the detection value storage unit,
The threshold adjustment unit performs the determination based on an average value of the change amounts of the specific signal detection signal width detected at least in the one minute each time the reception unit outputs a binarized signal for one minute. Adjust the threshold,
The code determination unit determines a code of the binarized signal for one minute by comparing the detection value stored in the detection value storage unit for the one minute with the adjusted determination threshold value. A radio wave receiver. The radio wave receiver according to any one of claims 1 to 6,
A timekeeping section for measuring the internal time,
And a time correction unit for correcting the internal time based on a code determined by the radio wave receiver.

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