JP2012026810A - Time data receiving apparatus and radio clock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a time data receiving apparatus and a radio clock capable of more surely acquiring a time code contained in a standard radio wave.SOLUTION: A time data receiving apparatus includes: receiving means capable of receiving a standard radio wave containing a time code in at least two frequencies; time code acquisition means for acquiring the time code of the received standard radio wave; and reception control means which causes the receiving means to start receiving the standard radio wave in a first frequency at a reception starting time of the standard radio wave, and causes the receiving means to start receiving the standard radio wave in the other second frequency when the time code acquisition means can not acquire the required time code on the basis of the standard radio wave in the first frequency. If a standard radio wave reception period includes a transmission period of out-of-time information to be sent out within a quarter past after and/or before every hour, the time code acquisition means acquires the time code in any other period of time than this transmission period.

Description

  The present invention relates to a time data receiving device that receives a standard radio wave and obtains time information, and a radio timepiece including the time data receiving device.

  There has been a radio timepiece having a function of receiving a standard radio wave to acquire time information and correcting the time. In the standard radio wave, time and date data is transmitted by a plurality of codes (time codes) arranged according to a predetermined encoding format. In the radio timepiece, time information can be acquired by decoding the time code.

  As such a standard radio wave, there is a long wave broadcast in Japan with a call sign set as JJY. This JJY standard radio wave is currently transmitted at frequencies of 40 kHz and 60 kHz from transmitting stations in Fukushima Prefecture and Saga Prefecture, respectively. Accordingly, which frequency of the standard radio wave can be received in a better reception state varies depending on the location in Japan.

  In addition, the radio wave in the frequency band used for transmitting the standard radio wave propagates to a place away from the transmission point. That is, the standard radio wave can be received even at a point away from the transmitting station, but a lot of noise is often mixed. Therefore, there is a case where complete time information cannot be acquired with certainty only by acquiring the time code once.

  Therefore, conventionally, when one standard radio wave is continuously received for a predetermined time, and time information cannot be acquired with a precision exceeding a predetermined reference within the predetermined time, the other standard radio wave is automatically acquired. A radio timepiece that acquires time information by switching tuning to a radio frequency has been developed (for example, Patent Document 1).

JP 2003-75561 A

  However, some of the standard radio waves transmit information other than the time such as a call sign Morse code and stop wave notice information at a predetermined timing every hour. Therefore, complete time data cannot be acquired at this timing. In particular, if the reception period is long, such as when receiving two standard radio waves, if the standard radio wave reception period includes the transmission timing of information other than this time, the consistency of the time information to be acquired will be improved. There is a problem of causing problems.

  An object of the present invention is to provide a time data receiving apparatus that can more reliably acquire time information included in a standard radio wave, and a radio timepiece including the time data receiving apparatus.

In order to achieve the above object, the invention according to claim 1
A receiving means capable of receiving a standard radio wave including a time code at at least two frequencies, a time code obtaining means for obtaining a time code based on reception data of the standard radio wave received by the receiving means, and a standard radio wave reception start time The reception means starts reception of a standard radio wave of the first frequency from the at least two frequencies, and the time code acquisition means is based on data received by the reception means of the standard radio wave of the first frequency. A reception control means for causing the reception means to start receiving a standard radio wave having a second frequency different from the first frequency out of the at least two frequencies. In the data receiving device,
The time code acquisition means includes
If the period for receiving the standard radio waves of the first frequency and / or the second frequency includes a period for sending out-of-time information to be sent in the 15-minute range and / or 45-hour range, the out-of-time information The time code is acquired based on the data received by the receiving means in a period excluding the transmission period of.

The invention according to claim 2 is the time data receiving device according to claim 1,
The reception control means includes
Ending radio wave reception of the first frequency by the receiving means before the transmission period of the out-of-time information starts,
If the time code acquisition means cannot acquire the required time code based on the reception data of the standard frequency radio wave of the first frequency, the reception means The reception of the second frequency radio wave is started.

The invention described in claim 3
A receiving means capable of receiving a standard radio wave including a time code and one reception frequency from among at least two frequencies at which the standard radio wave is transmitted are selectively set, and the standard radio wave of the set reception frequency is set. In a time data receiving apparatus comprising: a reception control means for controlling the timing at which the reception means is received; and a time code acquisition means for acquiring a time code based on standard radio wave reception data at a set reception frequency.
The time code acquisition means includes
When the standard radio wave having the reception frequency set by the reception control means has a transmission period for non-time information in a format different from the transmission format for time information, the reception is performed in a period excluding the transmission period for the non-time information. The time code is obtained based on the data received by the means,
The reception control means includes
When the time code acquisition unit cannot acquire the necessary time code based on the reception data by the reception unit of the standard radio wave of the first frequency set as the reception frequency first, of the at least two frequencies, A time data receiving apparatus characterized in that a second frequency different from the first frequency is set as a reception frequency and is received by the receiving means.

The invention according to claim 4 is the time data receiver according to any one of claims 1 to 3,
The reception control means includes
Set a reception period in which a plurality of frames can be obtained for each time code for each reception frequency,
The time code acquisition means includes
Based on data obtained by acquiring the input signal from the receiving means over a plurality of frames of a time code at a predetermined sampling frequency and integrating the input signals acquired over the plurality of frames for each frame position It is characterized by acquiring the time code.

The invention according to claim 5 is the time data receiver according to claim 4,
The receiving means includes
The time code signal is demodulated from the received standard radio wave of the reception frequency, and either a low level signal or a high level signal is output to the time code acquisition unit for each frame position based on a predetermined reference signal strength. It is characterized by that.

The invention according to claim 6 is the time data receiver according to claim 4,
The time code acquisition means includes
Whether the input signal from the receiving means is low level or high level is determined for each frame position based on a predetermined reference signal strength, and is acquired as binary data.

The invention according to claim 7 is the time data receiver according to claim 3 or 4,
The reception control means includes
In the period for sending out-of-time information, reception of the standard radio wave by the receiving unit is stopped.

The invention according to claim 8 is the time data receiver according to claim 3 or 4,
The reception control means includes
The reception means ends the reception of the first frequency before the transmission period of the out-of-time information starts, and the time code acquisition means is based on data received by the reception means of the standard radio wave of the first frequency. When the necessary time code cannot be acquired, the reception frequency and the reception period at the reception frequency are set so that the reception unit starts receiving the second frequency after the transmission period of the out-of-time information ends. It is characterized by

The invention according to claim 9 is the time data receiver according to claim 7 or 8,
Equipped with a timekeeping means to count the current time,
The reception control means includes
Based on the current time counted by the time measuring means, the reception means stops receiving the standard radio wave during the out-of-time information transmission period.

The invention described in claim 10 is the time data receiver according to claim 3 or 4,
The standard radio wave includes JJY which is a Japanese standard radio wave transmission station.
The at least two frequencies include 40 KHz and 60 KHz,
The out-of-time information includes a call sign,
The non-time information transmission period is 15 minutes per hour and 45 minutes per hour.

The invention according to claim 11 is the time data receiving device according to any one of claims 1 to 4,
Comprising storage means for storing the reception frequency at which the time code has been successfully acquired;
The reception control means includes
The reception frequency stored in the storage means is set as the first frequency.

The invention according to claim 12
A time counting means for counting the current time;
The time data receiving device according to any one of claims 1 to 11,
A radio timepiece comprising: a time correcting means for decoding a time code acquired by the time data receiving device, calculating a time, and correcting a current time of the time measuring means based on the calculated time It is.

  According to the present invention, since the time code is obtained from data other than the call sign and stop information transmission period included in the received standard radio wave, the time information can be more reliably obtained based on the received data of the standard radio wave. There is an effect that can be.

It is a block diagram which shows the internal structure of the radio timepiece of embodiment of this invention. It is a figure explaining the decoding process of a time code. It is a figure explaining the setting method of the period which performs the reception process of a standard radio wave. It is a flowchart which shows the control processing procedure of time correction operation | movement. It is a flowchart which shows the procedure of a second synchronization detection process. It is a flowchart which shows the procedure of a time data acquisition process.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an internal configuration of a radio timepiece according to an embodiment of the present invention.

  The radio timepiece 1 of this embodiment includes a CPU (Central Processing Unit) 20, a RAM (Random Access Memory) 21, a ROM (Read Only Memory) 22, an oscillation circuit 13, a frequency divider circuit 14, and a clock circuit 15. An operation unit 16, a liquid crystal display 17, an antenna 10, a tuning circuit 11, a radio wave receiving circuit 12, and the like.

  The CPU 20 (reception control means, time code acquisition means, time correction means) performs overall control of the radio timepiece 1 and various calculations. The CPU 20 reads various programs from the ROM 22 as necessary, displays the time on the liquid crystal display 17, decodes the data input from the radio wave reception circuit 12, acquires time information, and the timekeeping circuit 15 holds it. Correct the current time data.

  The RAM 21 provides a working memory space to the CPU 20. The RAM 21 also includes a reception time setting storage unit 21a that stores setting data of the time at which the radio timepiece 1 receives standard radio waves, and a reception information storage unit 21b that stores the frequency of the standard radio waves received last time and the reception date and time ( Storage means).

  The ROM 22 stores various programs executed by the CPU 20 and initial setting data. The ROM 22 also includes a reception setting table 22a that records the frequency of standard radio waves in each region and the setting of the tuning circuit 11 corresponding to these frequencies.

  The oscillation circuit 13 generates a signal having a predetermined frequency and outputs the signal to the frequency divider circuit 14. The frequency dividing circuit 14 divides the frequency signal input from the oscillation circuit 13 to generate a signal having a frequency required by the CPU 20 or the time measuring circuit 15. An output signal of the frequency dividing circuit 14 is input to the time measuring circuit 15 as time measuring means via the CPU 20. Then, the timer circuit 15 counts the current time based on the input signal and outputs it to the CPU 20.

  The operation unit 16 converts a user operation into an input signal and outputs the input signal to the CPU 20. The operation unit 16 is not particularly limited, but is a button, for example.

  The liquid crystal display 17 displays the current time, the operating state of the radio timepiece 1, information related to various functions other than the time display, and the operation menu based on the control signal from the CPU 20.

  The antenna 10 is, for example, a bar antenna configured by providing a winding around a ferrite core. In addition, the tuning circuit 11 includes, for example, a plurality of capacitors and switches connected to the capacitors. The radio timepiece 1 receives a standard radio wave having a resonance frequency determined by a combination of the inductance of the antenna 10 and the total capacity of the capacitor of the tuning circuit 11.

  In the tuning circuit 11, the total capacity of the capacitors coupled to the antenna 10 can be changed by switching on / off combinations of the switches according to a command from the CPU 20. By changing the resonance frequency in this manner, the radio timepiece 1 is configured to be able to receive standard radio waves having a plurality of different frequencies. Alternatively, the frequency of the standard radio wave received may be changed by changing the inductance of the antenna.

  The radio wave receiving circuit 12 amplifies the received standard radio wave signal and demodulates the time code signal included in the standard radio wave to shape the waveform. The radio wave receiving circuit 12 outputs the demodulated time code signal to the CPU 20. The antenna 10, the tuning circuit 11, and the radio wave receiving circuit 12 constitute a receiving means.

  Next, a time code decoding process executed in the radio timepiece 1 of the present embodiment will be described.

  In the standard radio wave, a time code in which 60 1-second codes are arranged according to a predetermined format is transmitted every minute. For example, in the case of JJY, “1” is a marker indicating 0 second (minute synchronization point) and a position marker indicating 9, 19, 29, 39, 49, 59 seconds. There are three types: a code and a code indicating binary numbers “0” and “1”, respectively. The standard radio wave is an amplitude-modulated wave in which these three types of codes are expressed by changing the ratio of the duration time between the large amplitude period and the small amplitude period. For example, in JJY, the small amplitude is 10% of the large amplitude, and the period of the large amplitude is 0.8 seconds for the “0” code, 0.5 seconds for the “1” code, and 0.5 seconds for the “P” code. 0.2 seconds. The start position (second synchronization point) of each second is indicated by a large amplitude rising edge in JJY. The arrangement pattern of “0” code and “1” code indicates the hour, minute, date, year, day of the week, daylight saving time, and the like.

  In addition, in JJY standard radio waves, JJY call sign by Morse code and information on scheduled stoppage by maintenance, etc., between 40 to 58 seconds, 15 minutes per hour and 45 minutes per hour, respectively. Information (hereinafter referred to as “call sign etc.”) is being transmitted.

  The radio wave receiving circuit 12 according to the present embodiment includes, but is not limited to, a comparator that compares the amplitude intensity of the demodulated signal with a predetermined reference amplitude. This comparator outputs a low level signal to the CPU 20 during a period when the amplitude is larger than a reference amplitude (for example, 55% of the large amplitude), and outputs a high level signal to the CPU 20 during a period when the amplitude is smaller than a predetermined reference amplitude. Shape the waveform with an active-low output configuration. The CPU 20 determines whether the input signal from the radio wave receiving circuit 12 is a high level signal or a low level signal at a predetermined sampling frequency (for example, 50 Hz). Then, the CPU 20 digitizes the determination result and acquires, for example, the high level signal as “1” and the low level signal as “0”. In the present embodiment, when the second synchronization point is determined, the time code signal acquired by the CPU 20 is decoded in units of 60 seconds of data (one frame).

  FIG. 2 is a diagram for explaining time code decoding processing.

  In the time code decoding process, 59 seconds and 0 seconds continuous “P” codes are detected from the acquired data, and the minute synchronization point is identified as the first position of the second “P” code. Then, the code arrangement for one frame is decoded from this synchronization point, and the current time information is acquired. As shown by the solid lines in FIGS. 2A to 2E, the data input from the radio wave receiving circuit 12 and determined to be binarized by the CPU 20 stands at a “0” value (low level) at the second synchronization point. The value changes to a “1” value (high level) after a predetermined period that differs for each code.

  However, when noise of a level equal to or higher than the low-level signal strength of the standard radio wave is mixed in or the reception strength of the standard radio wave is reduced to a level equivalent to the noise strength, the signals shown in FIGS. As indicated by a broken line, data erroneously output from the radio wave receiving circuit 12 due to noise is included. If the frequency of errors due to noise increases, the accurate current time cannot always be acquired. Therefore, the data of the next frame is acquired following the data of one frame of FIG. 2A (FIG. 2B), each of these frame data is individually stored in the RAM 21, and each frame position is also stored. Store the integrated value of data. Error data due to randomly mixed noise is suppressed by an integrated value of a plurality of frames, thereby improving accuracy.

  When the frequency of error data mixing is slightly high, for example, error data appears at the same frame position as shown in the 18th and 32nd bits of the data in FIGS. 2 (b) and 2 (c). It can happen. In order to reduce such error bias and distribute it on an average, it is desirable to further increase the number of integrations. For example, as shown in FIG. 2 (d) and FIG. 2 (e), when two frames of data are acquired and five frames of data are integrated, a horizontal broken line as shown in FIG. 2 (f). All the data is completely separated into the high level and the low level by the reference line indicated by.

  As shown in FIG. 2 (f), the integration process of a plurality of time codes may be terminated when it is determined that the time code is completely separated, or the number of integrations is specified in advance (for example, (8 times) The reception period may be determined.

  Also, the value of the first digit data changes every minute in each frame. Therefore, correct time data cannot be obtained by simple integration. Therefore, for example, the process of decoding the time code of each frame every minute is performed, and it is determined whether or not the error data exists by checking whether or not the decoded value changes in the correct order.

  FIG. 3 is a diagram for explaining a method for setting a period during which reception processing is performed.

  As described above, when the number of data to be integrated is increased by extending the standard radio wave reception duration, the accuracy of the time information is improved. However, if the data to be integrated includes data for 15 minutes per hour, which is a call sign transmission period, and 45 minutes per hour, the integrated data will be disturbed by mixing data in a format different from that for other hours. It will be. Further, if the time integration is continued for an excessively long time, the merit of integrating the same data decreases due to the change of the time data and date data. Therefore, in this embodiment, the maximum reception duration per standard radio wave of one frequency is set to 8 minutes. First, reception is performed at one standard radio frequency for 8 minutes every hour.

  In the JJY standard radio wave, time information is transmitted at two different frequencies, that is, 40 KHz and 60 KHz, respectively, from two different points, that is, Fukushima Prefecture and Saga Prefecture. When the user of the radio timepiece 1 moves in Japan, or when the ionization state of the ionosphere changes, the frequency at which reception is easy may change. Therefore, if one of the standard radio waves, for example, the 40 KHz standard radio wave (JJY40) is received for 8 minutes and the time data cannot be acquired, the radio timepiece 1 automatically receives the standard radio wave of 60 KHz ( Switch to the reception of JJY60), and receive again for 8 minutes.

  However, if the standard radio wave (JJY60) of the other frequency is received for 8 minutes after receiving the standard radio wave (JJY40) of one frequency from 8 o'clock for 8 minutes, the 8th minute is received at the other frequency (JJY60). This data includes data such as a call sign transmitted every 15 minutes. If the data of the 8th minute is added to the data up to the 7th minute, the data is disturbed. Therefore, the radio timepiece 1 temporarily waits when the reception processing with the standard radio wave (JJY40) of one frequency is completed, and after sending the call sign or the like, for example, after the current time is 16 minutes, The standard radio wave (JJY60) reception process is started.

  Next, the procedure of the time correction operation by the radio timepiece 1 of the present embodiment will be described.

  FIG. 4 is a flowchart showing a control procedure by the CPU 20 of the time correction operation using JJY standard radio waves.

  The control process by the CPU 20 of the radio timepiece 1 of the present embodiment is a process that is automatically called and executed every hour on the basis of the current time data counted by the timer circuit 15. When this control process is started, the CPU 20 first determines whether or not the current time is a standard radio wave reception time (step S11). This list of standard radio wave reception times is set in advance, for example, from 0:00 to 5:00 on the basis of the user's operation on the operation unit 16, and stored in the reception time setting storage unit 21a. When it is determined that the current time is not the reception time of the standard radio wave, the CPU 20 ends the control process as it is without performing the subsequent processes.

  If it is determined that it is the reception time of the standard radio wave, the CPU 20 next determines whether or not this time correction processing has not been performed today (step S12). When it is determined that the current time correction processing has already been performed based on the reception history stored in the reception information storage unit 21b, for example, from 2 o'clock to 5 o'clock after the time adjustment is performed at 1 o'clock, “ The process branches to “NO”, and the CPU 20 ends the control process without correcting the time again.

  If it is determined that today's time correction processing has not yet been performed, the process branches to “YES”, and the CPU 20 reads the frequency at which the previous standard radio wave was received from the reception information storage unit 21b. Then, the CPU 20 reads the setting of the tuning circuit 11 corresponding to the read frequency from the reception setting table 22a, and changes the setting of the tuning circuit 11 (step S13). Then, the CPU 20 performs second synchronization detection processing described later (step S14), and identifies the second synchronization point based on the time code signal input from the radio wave receiving circuit 12.

  Next, the CPU 20 determines whether or not the acquisition of the second synchronization point has succeeded in the second synchronization point detection process of step S14 (step S15). If it is determined that the second synchronization point has not been successfully acquired, the process of the CPU 20 proceeds to step S21. If it is determined that acquisition of the second synchronization point is successful, the process of the CPU 20 proceeds to step S16.

  When the second synchronization point is acquired, the CPU 20 performs time data acquisition processing (step S16). Although the time data acquisition process will be described later, the CPU 20 determines each code included in the time code signal input from the radio wave reception circuit 12 and acquires the time information by decoding it.

  Subsequently, the CPU 20 determines whether or not acquisition of time data has succeeded in the time data acquisition process of step S16 (step S17). If it is determined that the time data acquisition is successful, the process of the CPU 20 branches to “YES” and proceeds to step S31. If it is determined that the acquisition of time data has not been successful, the process branches to “NO”, and the CPU 20 determines whether or not 8 minutes have elapsed since the start of the control process (step S18). When it is determined that 8 minutes have not elapsed since the start of the control process, the process of the CPU 20 returns to step S16 and the time data acquisition process is repeated. If it is determined that 8 minutes have elapsed since the start of the control process, the process of the CPU 20 proceeds to step S21.

  If it is determined in step S15 that the second synchronization point has not been successfully acquired, and if it is determined in step S18 that eight minutes have passed without acquiring time data, the CPU 20 Then, based on the setting data stored in the reception setting table 22a, a setting process is performed for switching the JJY reception frequency from the frequency tuned in the process of step S13 to the other frequency (step S21). Then, the CPU 20 determines whether or not 16 minutes have elapsed since the start of the control process (step S22). While it is determined that 16 minutes have not elapsed since the CPU 20 started the control process, the CPU 20 repeats this elapsed time determination process without shifting to the next processing operation.

  When it is determined that 16 minutes have elapsed since the start of the control process, the CPU 20 performs a second synchronization detection process again at the newly set frequency (step S24). The content of the process in step S24 is the same as the content of the second synchronization detection process in step S14. Then, the CPU 20 determines whether or not the acquisition of the second synchronization point has succeeded (step S25). If it is determined that the acquisition of the second synchronization point has not been successful, the CPU 20 causes the liquid crystal display 17 to display reception failure (step S30), and ends the control process.

  If it is determined in step S25 that the second synchronization point has been successfully acquired, the CPU 20 subsequently performs time data acquisition processing (step S26). The contents of the process in step S26 are the same as the contents of the time data acquisition process in step S16. And CPU20 discriminate | determines whether acquisition of time data was successful (step S27). If it is determined that the acquisition of time data has not been successful, the process of the CPU 20 proceeds to step S28, and the CPU 20 determines whether 8 minutes have elapsed since the start of the second synchronization detection process (step S24). Determine. If it is determined that 8 minutes have not elapsed, the process of the CPU 20 returns to step S26 and the time data acquisition process is repeated. If it is determined that 8 minutes have elapsed, the CPU 20 causes the liquid crystal display 17 to display a reception failure (step S30), and ends the control process.

  If it is determined in step S17 or step S27 that the time data has been successfully acquired, the process of the CPU 20 proceeds to step S31. The CPU 20 corrects the current time data held by the timer circuit 15 in accordance with the acquired time. At this time, if there is a time difference between the reception of the standard radio wave and the correction of the current time data of the time measuring circuit 15, the CPU 20 corrects the current time to the time obtained by adding this time difference. The CPU 20 causes the liquid crystal display 17 to display the corrected time and the reception success (step S32). Further, the CPU 20 stores the current reception time and the frequency of successful reception in the reception information storage unit 21b. Then, the control process ends.

  Next, the second synchronization detection process (steps S14 and S24) and the time data acquisition process (steps S16 and S26) will be described.

  FIG. 5 is a flowchart showing the procedure of the second synchronization detection process. FIG. 6 is a flowchart showing a procedure of time data acquisition processing.

  When the second synchronization detection process is called, as shown in FIG. 5, the CPU 20 first obtains a time code signal of a predetermined period input from the radio wave receiving circuit 12 by converting it into binary data and storing it in the RAM 21 ( Step S141). This predetermined period is, for example, 10 seconds.

  The CPU 20 converts the acquired data for a predetermined period into a form for use in the second synchronization point detection process, and performs a calculation process for the converted data (step S142). In this conversion and calculation processing, for example, a total value of each data point and the data before and after it, or a moving average is calculated. By this processing, the influence of burst noise can be reduced. Alternatively, it is possible to calculate a time derivative from the difference between each data point and the data before and after the data point, and perform conversion so that it becomes a non-zero value only at a timing that changes between the high level signal and the low level signal. It is.

  The CPU 20 performs a second synchronization point detection process based on the data that has been subjected to the above conversion and calculation processes (step S143). The signal output from the radio wave receiving circuit 12 of this embodiment is switched from a high level to a low level at the beginning of each second in the JJY standard radio wave. The CPU 20 detects a point at which switching from a high level signal to a low level signal occurs periodically every second. Or it is good also as detecting the point which switches from a high level signal to a low level signal in the data which integrated the data of the acquisition period (10 seconds) with a 1 second cycle. As the detection method, for example, a method of obtaining a timing at which the correlation value between the model waveform and the measurement waveform is maximized or a method of obtaining a minimum value of data obtained by integrating the differential values is possible. Alternatively, various other conventionally known detection methods can be applied. It is also possible to apply a detection method to each of the data generated by the above conversion and calculation processing and the original data and compare the results.

  Next, the CPU 20 determines whether or not a second synchronization point has been appropriately detected (step S144). If it is determined that the second synchronization point has not been properly detected, the CPU 20 outputs an error signal (step S146), ends the second synchronization detection process, and returns to the control process. As a case where the second synchronization point is not detected, for example, when the reception level of the standard radio wave is low or the standard radio wave cannot be received and the CPU 20 cannot detect the falling from the high level signal to the low level signal, The falling position may be shifted each time due to noise.

  On the other hand, when it is determined that the second synchronization point has been detected, the CPU 20 determines the detected timing and stores it in the RAM 21 (step S145). Then, the second synchronization detection process is terminated and the process returns to the control process.

  Next, when the time data acquisition process is started, as shown in FIG. 6, the CPU 20 acquires the time code signal for 60 seconds, that is, one frame as binary data (step S161). The CPU 20 stores the binarized data in the RAM 21 and also stores in the RAM 21 a value obtained by adding the binarized data to the data at the same frame position in one frame period in the second and subsequent time data acquisition processing. (Step S162).

  Then, the CPU 20 detects a minute synchronization point from the acquired data (step S163). Specifically, the CPU 20 detects a “P” code that is continuously transmitted only at 59 seconds and 0 seconds per minute in JJY. This “P” code is detected, for example, by detecting a change from a low level signal to a high level signal at a timing of 0.2 seconds from the second synchronization point, or from 0.2 to 0.5 seconds from the second synchronization point. This is performed by detecting a high level signal in between. Alternatively, various other conventionally known detection methods can be used as a specific detection method of the “P” code.

  Next, the CPU 20 determines whether or not the minute synchronization point is properly detected (step S164). If it is determined that the minute synchronization point has not been properly detected, the CPU 20 outputs an error signal (step S166), ends the time data acquisition process, and returns to the control process. A case where a minute synchronization point is not detected is, for example, a case where a large noise is mixed at the timing of two “P” codes.

  On the other hand, if it is determined that the minute synchronization point has been detected, the CPU 20 next determines each code of the time code based on the data stored in the RAM 21 and also decodes the time code (step S165). ). Here, the CPU 20 decodes the data whose value does not change within the range of the acquired data such as year data, date data, day of the week data, based on the accumulated data. As shown in FIG. 2 (f), all frame positions or predetermined necessary frame positions, for example, a section excluding a frame position that is always “0” code, and three types of codes are determined. The accumulated data within the interval of 0.2 to 0.8 seconds required for this can be separated into high level and low level, so that each code necessary for obtaining time information is reliably determined and accurately Time information can be acquired.

  Further, the decoding result may be compared with the decoding result of the time code based on individually stored data. For example, when a large amount of noise is mixed together, or when the current time data of the timing circuit 15 deviates significantly from the accurate time and a call sign or the like is received, the decoding accuracy of one frame alone and another frame If the accuracy of the former is significantly inferior to the accuracy of decoding, it is possible to exclude the data of the frame and recalculate, or to add up again from the next frame data .

  For data whose value changes every minute, for example, 1-digit data, the CPU 20 performs code determination and decoding based on the data stored in the RAM 21 for each frame, and changes the decoded value every minute. Confirm whether or not is appropriate. Alternatively, the optimal time information as a whole is acquired by correlating the data of each frame stored in the RAM 21 with the model data indicating the change pattern of the code arrangement that may occur with the passage of time per minute. You can also.

  If the decoding of the time code is not successful in the process of step S165, the CPU 20 ends the time data acquisition process as a decoding error and returns to the control process.

  This time data acquisition process (steps S16 and S26) is called once a minute and a maximum of 8 times. Then, the number of data accumulated in the accumulated data at each frame position is increased by the calculation process in step S162. If the time data cannot be acquired even in the eighth process, the time data acquisition process is terminated by the processes in steps S18 and S28.

  As described above, according to the radio timepiece 1 of the present embodiment, when the JJY reception period includes the transmission period of the call sign and the stop information transmitted at 15 minutes per hour and 45 minutes per hour in JJY. Only the normal time code excluding the call code and the time code of the stop information is acquired, and the time information is acquired based on the acquired time code. Therefore, it is possible to accurately decode the time code while suppressing the influence of mixing of the call sign and the stop information.

  In addition, since it is possible to exclude the data of the reception period such as call sign after receiving the standard radio wave for a predetermined period once, the time of the clock circuit which is a reference for setting the reception time is greatly deviated from the accurate time. Even in this case, accurate time information can be acquired by resetting the call sign period in the middle of the time code decoding process.

  Further, according to the radio timepiece 1 of the present embodiment, the reception of the first standard radio wave (for example, JJY40) before the call sign and wave stop information transmission period transmitted at 15 minutes and 45 minutes per hour. , And the reception frequency setting is changed during the call sign / stop information transmission period, and reception of the second standard radio wave (for example, JJY60) is started after the call sign / stop information transmission period. . Accordingly, it is possible to accurately decode the time code while omitting wasted time from the reception time of the standard radio wave at each reception frequency, while extending the necessary time.

  Also, when receiving a standard radio wave other than JJY, if there is a call sign transmission period, the time information can be appropriately acquired without using the data for that period, so the time information acquisition accuracy is improved. be able to.

  Conversely, when receiving a standard radio wave without transmission of a call sign or the like, it is possible to obtain time information without adjusting the reception timing of the standard radio wave. The amount of calculation due to can be reduced.

  In addition, by acquiring the time code over multiple frames, integrating the acquired data at the same frame position and decoding the time code, the influence of random noise can be reduced, so the time can be more reliably Information can be acquired.

  Further, the radio wave receiving circuit 12 shapes and outputs a waveform from a demodulated received signal to either a high level signal or a low level signal based on the signal strength, so that the weight of data due to the magnitude of the absolute strength, strong noise, etc. The time information can be acquired more reliably by the number of accumulated frames without being affected by the above.

  Further, by acquiring the high-level signal and the low-level signal input from the radio wave receiving circuit 12 as binary data “0” and “1”, data processing can be simplified.

  In addition, by temporarily interrupting the reception process of the standard radio wave during a transmission period such as a call sign, it is possible to prevent power from being consumed in the reception process of data that is unnecessary for acquiring time information. In addition, since it is not necessary to include a process for excluding a call sign or the like in the time code decoding process, the decoding process can be simplified.

  In addition, the standard radio wave reception process is canceled during the call sign transmission period, and the standard radio wave reception frequency is switched during the reception process cancellation period, so that the time code decoding process is integrated without complicating it. The number of time code frame data can be increased.

  Further, by controlling the reception timing of the standard radio wave based on the time data of the time measuring circuit 15, it is possible to easily control the reception time of the standard radio wave.

  In particular, when a standard radio wave of multiple frequencies can be received in overlapping reception areas, such as JJY, and a call sign or the like interrupts the transmission contents of the receivable standard radio wave, the call sign is used in this way. Since it is possible to change the reception frequency by removing the transmission period such as the above, it is possible to extend the reception time without waste and to acquire more reliable time data.

  In addition, in many cases, the frequency of the standard radio wave for which the time code has been successfully acquired is stored in the reception information storage unit 21b, and reception processing is first performed at this frequency when the next standard radio wave is received. There is no need to repeat the reception process at two different frequencies.

  In addition, by mounting the above time data receiver on a radio-controlled timepiece, even when a user who travels around Japan wears it, it uses the received data acquired from a standard radio wave with an appropriate frequency during an appropriate reception period. The time of the radio timepiece can be corrected reliably.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above embodiment, only two JJY waves are to be received, but other standard radio waves such as WWVB in the United States, MSF in the United Kingdom, DCF77 in Germany and BPC in China may be received and decoded. . Since these other standard radio waves do not transmit a call sign or the like, a configuration in which the reception timing is not adjusted can be adopted. On the other hand, when performing time adjustment processing using other standard radio waves with transmission of a call sign or the like, the reception processing can be stopped in accordance with the transmission period of the call sign or the like. Further, when JJY is used as the second reception frequency when returning from another area, the above embodiment can be applied. In such a case, for example, JJY 40 can be received after 16 minutes, and JJY 60 can be received after 46 minutes as the third reception frequency. In the above-described embodiment, reception at the second reception frequency is started from 16 minutes even when the second synchronization detection process fails at the first reception frequency. It is also possible to start reception at the second reception frequency immediately after processing failure.

  Further, in the above embodiment, reception starts at noon and reception is performed for a maximum of 8 minutes. However, as long as the transmission period such as a call sign can be excluded, the reception start timing and the reception duration can be appropriately changed. It is. For example, the reception process may be started 15 seconds before the hour and the second synchronization process may be performed, and the time data acquisition process may be performed from the hour. Alternatively, reception may be started from 46 minutes at one frequency, and if time information cannot be obtained, reception may be started from the other frequency from 16 minutes. Alternatively, the reception period of the second frequency is, for example, 25 to 33 minutes, so that it is less affected by the difference between the current time and the correct time of the timekeeping circuit 15 by separating it from the call sign transmission period. It's also good.

  Even when a reception period including a call sign transmission period is set, the second synchronization detection process and the time data acquisition process can be performed without using the data of the call sign reception period. The CPU 20 can be set not to acquire the time code signal from the radio wave receiving circuit during this period by the input from the time measuring circuit 15. In such a case, it is possible to extend the reception continuation time corresponding to the time when the time code signal is not acquired. When excluding data such as call signs in this way, it is possible to exclude only data from 15 minutes 40 seconds to 55 seconds per hour and 45 minutes 40 seconds to 55 seconds per hour, which are the relevant period. It is good or you may exclude the data of the whole one frame including the said period.

  In the above embodiment, the radio wave receiving circuit 12 outputs binary data. However, the radio wave receiving circuit 12 can also be applied to a radio timepiece that outputs multilevel data.

  In the above embodiment, the liquid crystal display type timepiece is used. However, other digital display methods may be used, or the pointer type analog electronic timepiece may be used. In addition, the details shown in the above embodiment can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Radio time signal 10 Antenna 11 Tuning circuit 12 Radio wave receiving circuit 13 Oscillation circuit 14 Frequency dividing circuit 15 Timekeeping circuit 16 Operation part 17 Liquid crystal display 20 CPU
21 RAM
21a Reception time setting storage unit 21b Reception information storage unit 22 ROM
22a Reception setting table

Claims (12)

A receiving means capable of receiving a standard radio wave including a time code at at least two frequencies, a time code obtaining means for obtaining a time code based on reception data of the standard radio wave received by the receiving means, and a standard radio wave reception start time The reception means starts reception of a standard radio wave of the first frequency from the at least two frequencies, and the time code acquisition means is based on data received by the reception means of the standard radio wave of the first frequency. A reception control means for causing the reception means to start receiving a standard radio wave having a second frequency different from the first frequency out of the at least two frequencies. In the data receiving device,
The time code acquisition means includes
If the period for receiving the standard radio waves of the first frequency and / or the second frequency includes a period for sending out-of-time information to be sent in the 15-minute range and / or 45-hour range, the out-of-time information A time data receiving apparatus characterized in that a time code is acquired based on data received by the receiving means during a period excluding the transmission period. The reception control means includes
Ending radio wave reception of the first frequency by the receiving means before the transmission period of the out-of-time information starts,
If the time code acquisition means cannot acquire the required time code based on the reception data of the standard frequency radio wave of the first frequency, the reception means The time data receiving device according to claim 1, wherein reception of the radio wave of the second frequency is started. A receiving means capable of receiving a standard radio wave including a time code and one reception frequency from among at least two frequencies at which the standard radio wave is transmitted are selectively set, and the standard radio wave of the set reception frequency is set. In a time data receiving apparatus comprising: a reception control means for controlling the timing at which the reception means is received; and a time code acquisition means for acquiring a time code based on standard radio wave reception data at a set reception frequency.
The time code acquisition means includes
When the standard radio wave having the reception frequency set by the reception control means has a transmission period for non-time information in a format different from the transmission format for time information, the reception is performed in a period excluding the transmission period for the non-time information. The time code is obtained based on the data received by the means,
The reception control means includes
When the time code acquisition unit cannot acquire the necessary time code based on the reception data by the reception unit of the standard radio wave of the first frequency set as the reception frequency first, of the at least two frequencies, A time data receiving apparatus, wherein a second frequency different from the first frequency is set as a reception frequency and is received by the receiving means. The reception control means includes
Set a reception period in which a plurality of frames can be obtained for each time code for each reception frequency,
The time code acquisition means includes
Based on data obtained by acquiring the input signal from the receiving means over a plurality of frames of a time code at a predetermined sampling frequency and integrating the input signals acquired over the plurality of frames for each frame position A time code is acquired. The time data receiver according to claim 1, wherein the time code is acquired. The receiving means includes
The time code signal is demodulated from the received standard radio wave of the reception frequency, and either a low level signal or a high level signal is output to the time code acquisition unit for each frame position based on a predetermined reference signal strength. The time data receiving device according to claim 4. The time code acquisition means includes
5. The input signal from the receiving means is determined for each frame position based on a predetermined reference signal strength, and is acquired as binary data, whether the input signal is low level or high level. The time data receiver described. The reception control means includes
5. The time data receiving apparatus according to claim 3, wherein reception of a standard radio wave by the receiving unit is stopped during a transmission period of the out-of-time information. The reception control means includes
The reception means ends the reception of the first frequency before the transmission period of the out-of-time information starts, and the time code acquisition means is based on data received by the reception means of the standard radio wave of the first frequency. When the necessary time code cannot be acquired, the reception frequency and the reception period at the reception frequency are set so that the reception unit starts receiving the second frequency after the transmission period of the out-of-time information ends. The time data receiving device according to claim 3 or 4, characterized in that: Equipped with a timekeeping means to count the current time,
The reception control means includes
The time data receiving device according to claim 7 or 8, wherein reception of the standard radio wave by the receiving means is stopped during a transmission period of the out-of-time information based on the current time counted by the time measuring means. The standard radio wave includes JJY which is a Japanese standard radio wave transmission station.
The at least two frequencies include 40 KHz and 60 KHz,
The out-of-time information includes a call sign,
The time data receiving apparatus according to claim 3 or 4, wherein the transmission period of the out-of-time information is in a range of 15 minutes per hour and 45 minutes per hour. Comprising storage means for storing the reception frequency at which the time code has been successfully acquired;
The reception control means includes
The time data receiving device according to claim 1, wherein the reception frequency stored in the storage unit is set as the first frequency. A time counting means for counting the current time;
The time data receiving device according to any one of claims 1 to 11,
A radio timepiece comprising: a time correcting means for decoding a time code acquired by the time data receiving device, calculating a time, and correcting a current time of the time measuring means based on the calculated time .

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