JP2005003651A - Time data receiving device and method of correcting time data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent increase in errors, without achieving time correction, when wave reception fails. <P>SOLUTION: The failure or success of reception of standard wave conducted via a reception antenna 5 and a reception circuit 6 is discriminated by a CPU2. When success is discriminated, a time-counting circuit 9 corrects the counting present date and time. When failure is discriminated, a correction record contained in a RAM4 is referred to, and time correction quantity is calculated, based on the previous time correction quantity, the elapsed time from time before the last time correction date and time to the last time correction date and time, and the elapsed time from the last time correction date and time to the present time correction date and time; and the present time counted by the time-counting circuit 9 is corrected for the time correction quantity. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a time data receiving apparatus that receives radio waves including time information, and a time data correction method that corrects time data.
[0002]
[Prior art]
Currently, in each country (for example, Japan, the United States, Germany, etc.), a time code, that is, a longwave standard radio wave including a time code is transmitted. In Japan (Japan), two transmitting stations (Fukushima Prefecture and Saga Prefecture) transmit 40 kHz and 60 kHz long wave standard radio waves that are amplitude-modulated with a time code in a format as shown in FIG. The upper stage and the lower stage of FIG. 7 are continuous, and the right end of the upper stage time code and the left end of the lower stage time code represent the same time point.
[0003]
According to FIG. 7, the time code is transmitted in a frame of 60 seconds per cycle every time the minute digits of the correct time are updated, that is, every minute. The leading marker (M) corresponds to the rising edge of the minute (0 seconds per minute), which is the start time of the frame of 60 seconds (1 minute). The first marker (M) has a pulse width of 0.2 seconds, and the same position markers (P0 to P5) having a pulse width of 0.2 seconds are 9 seconds (P1) and 19 seconds (P2). ), 29 seconds (P3), 39 seconds (P4), 49 seconds (P5), and 59 seconds (P0). For this reason, two frames having a pulse width of 0.2 seconds at intervals of approximately 1 second (ie, those indicated by the head marker (M) and those indicated by the position marker (P0)) are present at the frame boundaries. (This will recognize the start of a new frame). The leading marker (M), which is the former of the two pulses, is the frame reference marker M. That is, the rising edge of the pulse indicated by the frame reference marker M is an accurate update of the digit of the current time.
[0004]
In the frame, the data such as the minute, hour, and integration date (number of days from January 1) at the start time (M) of the frame are stored in the 1 second range, the 10 second range, and the 20 to 20th respectively. It is encoded in binary coded decimal (BCD) in the 30-second range. In this case, logics 1 and 0 are represented by pulses having pulse widths of 0.5 seconds and 0.8 seconds, respectively. In addition, as shown in FIG. 7, a frame having a pulse width of 0.8 seconds, which is used as a simple delimiter as appropriate, is also arranged in the frame.
[0005]
By the way, a time data receiving device called a radio timepiece that receives such a standard radio wave and corrects the date and time data of the clock circuit by this standard has been put into practical use.
[0006]
In such a radio timepiece that receives radio waves and corrects the time, if the radio waves cannot be received in places where the radio waves are difficult to reach, for example, in the central part of a reinforcing steel house, the time data of the clock circuit must be corrected. Cannot be performed, and an error may occur in the date and time. Therefore, for example, a method of increasing the reception success rate by increasing the number of reception processes per day so that reception processes are performed three times a day at 2 am, 4 am, and 6 am has been used.
[0007]
Further, according to Patent Document 1, the success or failure of the reception of the standard radio wave is determined, and when it is determined to be successful and the date and time are corrected correctly, the display body is turned on and it is determined that the failure is detected and the date and time are not corrected. Discloses a time data receiving device that clearly indicates whether or not the display date and time is accurate by turning off the display. Specifically, whether the displayed time is the correct time corrected by the standard radio wave, or if the time is adjusted manually or when the standard radio wave cannot be received and cannot be corrected. Is provided with a means for the user to recognize.
[0008]
[Patent Document 1]
JP 9-43368 A
[0009]
[Problems to be solved by the invention]
However, if reception of radio waves fails continuously, the time remains corrected when the previous reception was successful. If the state in which reception is not possible continues, the difference (error) between the time being measured and the accurate time increases, and there is a problem that a certain accuracy cannot be maintained.
[0010]
An object of the present invention is to provide a time data receiving apparatus and a time data correcting method capable of preventing an error from being enlarged without time correction when reception of radio waves fails.
[0011]
[Means for Solving the Problems]
To solve the above issues,
The time data receiver of the invention according to claim 1 is
Time counting means for counting the reference clock signal to obtain current time data (for example, the oscillation circuit 7, the frequency dividing circuit 8, and the clock number circuit 9 shown in FIG. 1);
A radio wave receiving means (for example, the receiving antenna 5 and the receiving circuit 6 shown in FIG. 1) for receiving a standard radio wave including standard time data at time correction timing;
Determining means (for example, CPU 2 shown in FIG. 1; step S6 shown in FIG. 4) for determining success or failure of reception of the received standard radio wave;
When this determination means determines success, time correction means (for example, CPU 2 shown in FIG. 1) corrects current time data measured by the time measurement means based on standard time data included in the received standard radio wave. Step S10) shown in FIG.
Recording means (for example, shown in FIG. 3) for recording the correction by the time correction means;
When it is determined that the determination unit has failed, referring to the record, the previous time correction amount, the elapsed time from the previous time correction date and time to the previous time correction date and time, and the current time from the previous time correction date and time A time correction amount calculation means (for example, CPU 2 shown in FIG. 1; step S28 shown in FIG. 4) for obtaining a time correction amount based on the elapsed time until
Correction means (for example, CPU 2 shown in FIG. 1; step S29 shown in FIG. 4) for correcting the current time data measured by the time measuring means by the calculated time correction amount;
It is characterized by having.
[0012]
According to the first aspect of the present invention, first, the standard radio wave is received, and the determination unit determines whether the reception is successful. When it is determined that the reception is successful, the time correction means corrects the current time data counted by the time measuring means using the current time data obtained from the standard radio wave. At this time, in preparation for reception failure, the time correction amount calculation means refers to the correction record and calculates the time correction amount. When it is determined that the reception has failed, the correction unit corrects the current time data counted by the time measuring unit using the time correction amount.
Even when reception is unsuccessful, the correction means corrects the time correction amount, so that it is possible to prevent an increase in the error between the current time data counted by the time measuring means and the current time data of the standard radio wave.
[0013]
The invention according to claim 2 is the time data receiver according to claim 1,
Clarifying means (for example, the display unit 11 shown in FIG. 1; step S12 shown in FIG. 4) clearly indicates whether the time correction at the previous time correction timing is the time correction by the time correction means or the time correction by the correction means. Step S32) is provided.
[0014]
According to the invention described in claim 2, it is obvious that the same effect as that of the invention described in claim 1 can be obtained, whether the time adjustment by the time adjustment means or the time correction by the correction means is specified. it can.
For this reason, the user can recognize the accuracy of whether the displayed time is due to time correction or time correction.
[0015]
According to a third aspect of the present invention, in the time data receiving device according to the first or second aspect, it is clearly indicated that the determination by the determination means that the reception of the standard radio wave has failed has continuously occurred a predetermined number of times or more. It is characterized by comprising continuous failure indication means (for example, the display unit 11 shown in FIG. 1; step S34 shown in FIG. 4).
[0016]
According to the third aspect of the present invention, it is possible to obtain the same effect as the first or second aspect of the invention, and whether or not the number of consecutive reception failures is a predetermined number or more. Can be specified.
For this reason, the user can recognize the accuracy of whether or not the displayed time maintains a certain standard accuracy.
[0017]
The invention according to claim 4 is a time data correction method for correcting the current time data received by the time measuring means by receiving the standard radio wave including the standard time data,
A radio wave receiving step for receiving a standard radio wave (for example, step S4 shown in FIG. 4);
A determination step (for example, step S6 shown in FIG. 4) for determining success or failure of reception of the received standard radio wave;
A time correction step (for example, step S10 shown in FIG. 4) for correcting the current time data measured by the time measuring means based on the standard time data included in the received standard radio wave when it is determined that the determination is successful. )When,
A recording step (for example, step S14, step S16, step S20, step S22 shown in FIG. 4; step S306 shown in FIG. 6) for recording the correction in this time correction step;
If it is determined that the determination step is unsuccessful, referring to the record, the previous time correction amount, the elapsed time from the previous time correction date and time to the previous time correction date and time, and the previous time correction date and time to the current time A time correction amount calculating step for obtaining a time correction amount based on the elapsed time (for example, step S28 shown in FIG. 4);
A correction step (for example, step S29 shown in FIG. 4) for correcting the current time data timed by the time measuring means by the calculated time correction amount;
It is characterized by including.
[0018]
According to the fourth aspect of the present invention, first, the standard radio wave is received, and the determination step determines whether the reception is successful. When it is determined that the reception is successful, the time correction step corrects the current time data counted by the time measuring means using the current date and time data obtained from the standard radio wave. At this time, in preparation for reception failure, the time correction amount calculating step refers to the correction record and calculates the time correction amount. When it is determined that the reception has failed, the correction step corrects the current time data counted by the time measuring means using the time correction amount.
Even when reception is unsuccessful, the correction step corrects the time correction amount, so that the error between the current time data counted by the time measuring means and the current time data of the standard radio wave is prevented from expanding. Can do.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 is a block diagram of the time data receiving apparatus 1. As shown in FIG. 1, the time data receiving apparatus 1 includes a CPU (Central Processing Unit) 2, a ROM (Read Only Memory) 3, a RAM (Random Access Memory) 4, a receiving antenna 5, a receiving circuit 6, an oscillation circuit 7, a frequency divider. A circuit 8, a clock count circuit 9, a switch unit 10, and a display unit 11 are provided.
[0020]
The CPU 2 expands the program stored in the ROM 3 in the RAM 4 in accordance with the operation signal output from the switch unit 10, and processes and processes data based on the program and data between the functional units. Execute input / output, etc.
[0021]
The CPU 2 controls the reception circuit 6 by outputting a reception start signal C1 and a reception end signal C2 to the reception circuit 6. When the CPU 2 outputs the reception start signal C1, the receiving circuit 6 starts receiving the standard radio wave, and the CPU 2 receives the time code TC from the receiving circuit 6. The time code TC is input to the CPU 2 three times every minute, and the CPU 2 converts the time code TC into current date and time data and stores it in a standard time code storage area 414 described later. Then, when confirming that the time code TC has been input three times, the CPU 2 outputs a reception end signal C2 to the reception circuit 6 and ends the reception of the standard radio wave.
[0022]
The CPU 2 determines the consistency of the received data and the success or failure of reception based on the standard time code. Specifically, consistency determination for each frame and consistency determination for three frames are performed. In the consistency determination for each frame, it is determined whether or not each value of the hour / minute data and the date data is an appropriate value. For example, the minute data range of the minute data is 0 to 9, and the range of the ten minute digit is 0 to 5, so if the received minute data value is 9, it is determined that there is no consistency. To do. Similarly, the consistency of all the digits in the three frames is determined. Consistency determination between the three frames is the same in the reception date data as to whether the reception time data is continuous data every other minute in the standard time code received three times every minute. Determine whether it is data. For example, if the value of the received minute data is the first 20 minutes, the second 20 minutes, and the third 21 minutes, the values are not continuous. In this case, it is determined that there is no consistency. In the two determinations, if it is determined that there is consistency, it is determined that the reception has been successful, and if it is determined that there is no consistency, it is determined that the reception has failed.
[0023]
When the standard time signal is successfully received, the CPU 2 rewrites the current date and time counted by the clock circuit 9 with the standard time code input at the third time as the current date and outputs a preset signal P to the frequency divider 8. 1. Reset the output timing of the 1-minute signal m.
[0024]
Further, the CPU 2 calculates a unit time correction amount, which will be described later, in preparation for the case where the standard radio wave reception fails. Then, an estimated correction date and time is calculated using this unit time correction amount, and the current date and time counted by the clock count circuit 9 is corrected. Then, as in the case of successful reception, the preset signal P is output to the frequency dividing circuit 8, and the output timing of the 1-minute signal m is reset.
[0025]
When the reception is successful, the CPU 2 determines the elapsed time T1 (= t2−t1) from the previous successful reception date / time t1 (previous reception date / time) to the current date / time t2 (reference reception date / time) when reception was successful, and the previous successful reception. Elapsed time T2 (= t2′−t1 ′) from the total clock number circuit date and time t1 ′ (reference time and date) before correction to the total clock number circuit date and time t2 ′ (temporary time and date) before correction when reception is successful , The error per unit time (= (T2−T1) / T1) (unit time correction amount) of the clock counting circuit 9 is calculated. Thereafter, if reception fails, the error per unit time and the previous reception success date and time t2 (reference reception date and time) to the total clock number circuit date and time t3 ′ (provisional timing date and time) before correction at the time of reception failure Using the elapsed time T3 (= t3′−t2), the error (= {(T2−T1) / T1} * T3) from the previous successful reception date and time t2 to the current clock count circuit date and time t3 ′ is calculated. To do. Then, the estimated correction date and time are calculated by subtracting this error from the current date and time counted by the counting clock circuit 9, and the date and time are estimated and corrected.
[0026]
Further, the CPU 2 determines the time displayed on the display unit 11, that is, the accuracy of the current date and time counted by the clock count circuit 9. Here, if the current date / time is the date / time corrected by reception of radio waves, accuracy A, if the date / time has failed to be corrected and corrected by the estimated correction date / time, accuracy B, correction by the estimated correction date / time is continuously performed a predetermined number of times or more. If so, it is determined that the accuracy is C. Then, the CPU 2 causes the display unit 11 to output this accuracy.
[0027]
The ROM 3 stores a system program 32 and a time data correction program 34 as shown in FIG. The time data correction program 34 is provided with a radio wave reception program 342 and a time correction program 344 as subroutines.
[0028]
The RAM 4 temporarily stores various programs executed by the CPU 2 and data processed by the CPU 2 under the control of the CPU 2. Input / output of this data is controlled by the CPU 2. In this RAM 4, as shown in FIG. 3, a reference reception date / time storage area 402, a previous reception date / time storage area 404, a provisional time / date / time storage area 406, a reference time / date / time storage area 408, a unit time correction amount storage area 410, a continuous reception failure A number storage area 412, a standard time code storage area 414, and the like are provided.
[0029]
The reference reception date storage area 402 stores the reference reception date and time. The reference reception date and time is the current date and time extracted by the CPU 2 from the standard radio wave when the radio wave is successfully received. That is, the latest reception success date / time is always stored in the reference reception date / time storage area 402.
[0030]
The previous reception date storage area 404 stores the previous reception date and time. The previous reception date and time is the reference reception date and time before the CPU 2 stores the current date and time extracted from the standard radio wave in the reference reception date and time storage area 402 when the reception of the radio wave is successful. That is, the previous reception date / time storage area 404 stores the reception success date / time immediately before the latest reception success date / time by the CPU 2. Accordingly, the reception date / time of the last two receptions is stored in the reference reception date / time storage area 402 and the previous reception date / time storage area 404.
[0031]
The temporary timing date and time storage area 406 stores temporary timing date and time. The provisional timing date and time is the current date and time counted by the counting clock circuit 9 when the CPU 2 corrects the date and time when reception is successful and corrects the date and time when reception fails.
[0032]
The reference time / date storage area 408 stores the reference time / date. The reference time and date is the current date and time counted by the clock circuit 9 when reception is successful. In other words, the reference time and date storage area 408 stores the current date and time counted by the clock counter circuit 9 when reception is successful, and is updated each time reception is successful. Therefore, immediately after the date and time correction process at the time of successful reception, the current date and time counted by the clock count circuit 9 at the time of the last two successful receptions are stored in the temporary time and date storage area 406 and the reference time and date storage area 408. The
[0033]
The unit time correction amount storage area 410 stores the unit time correction amount. The unit time correction amount is an error of the counting clock circuit 9 generated per unit time. When reception is successful, the elapsed time of the standard radio wave date and time calculated from the reference reception date and time and the previous reception date and time, the provisional timing date and time, and the reference The CPU 2 calculates the elapsed time of the date and time counted by the clock count circuit 9 calculated from the time and date.
[0034]
The continuous reception failure frequency storage area 412 stores the continuous reception failure frequency. The number of continuous reception failures is the number of times of continuous failure in receiving the standard radio wave, and is incremented only when reception fails and reset to “0” when reception is successful.
[0035]
The standard time code storage area 414 stores the standard time code. The standard time code is a reception date and time extracted by the CPU 2 from the time code TC output from the reception circuit 6. This reception date and time includes hour / minute data, day of the week data, accumulated date data, year data, and the like. Here, reception time data storage areas X1 to X3 and reception date data storage areas D1 to D3 are provided.
[0036]
The reception time data storage areas X1 to X3 store reception time data. The reception time / minute data is the hour / minute data extracted by the CPU 2 from each time code TC output three times continuously from the reception circuit 6 every minute. The extracted hour / minute data is stored in a continuous order.
[0037]
Reception date data storage areas D1 to D3 store reception date data. The CPU 2 extracts the accumulated date data and year data from each time code TC output three times continuously from the receiving circuit 6 every minute. Then, the accumulated date data is converted into date data (what month and what day), and the date data and year data are stored in the sequential order as received date data.
[0038]
The reception hour / minute data storage area X3 also stores hour / minute data that is the source of rewriting the current time actually counted by the clock counting circuit 9 as the current time. That is, the CPU 2 receives the elapsed time from the third radio wave reception until the current date and time are corrected to the reception time data stored in the reception time data storage area X3. Rewrite X3. When the date changes between the time of the third radio wave reception and the date correction, the CPU 2 sets the reception date data storage area D3 by the number of days obtained by adding the elapsed date and time to the reception date data stored in the reception date data storage area D3. rewrite.
[0039]
The CPU 2 determines the consistency of the reception data described above using the reception time data and the reception date data stored in the reception time data storage areas X1 to X3 and the reception date data storage areas D1 to D3. .
[0040]
The receiving antenna 5 receives a long wave standard wave transmitted from a transmitting station or the like and outputs it to the receiving circuit 6.
[0041]
The receiving circuit 6 is controlled by a reception start signal C1 and a reception end signal C2 output from the CPU 2, and receives radio waves. When the reception start signal C1 is input, the reception of the radio wave tuned to the signal of the predetermined frequency from the radio wave received by the reception antenna 5 is continued until the reception end signal C2 is input. The received standard radio wave is amplified and demodulated and converted into a corresponding electric signal. The time code TC is extracted from the electrical signal and output to the CPU 2.
[0042]
Although not shown, the receiving circuit 6 is a tuning circuit that cuts an unnecessary frequency from an electrical signal output from the receiving antenna 5 and extracts a specific frequency signal, a high-frequency amplifier circuit that amplifies the specific frequency signal, and a local oscillator. A PLL frequency synthesizer to be used, a mixer for mixing the signal from the PLL frequency synthesizer with the signal amplified by the high frequency amplifier circuit, a bandpass filter for extracting a desired intermediate frequency signal from the signal from the mixer, and A detection circuit that obtains a baseband signal from the intermediate frequency signal extracted by the bandpass filter, and an A / D conversion circuit that converts the baseband signal obtained by this detection circuit into a digital signal and outputs it to the CPU 2 as the time code TC Is a superheterodyne receiver circuit.
[0043]
The oscillation circuit 7 always outputs a clock signal having a constant frequency to the frequency dividing circuit 8.
The frequency dividing circuit 8 counts the clock signal input from the oscillation circuit 7 and outputs a 1-minute signal m to the clock counting circuit 9 every time the counted value becomes a value corresponding to 1 minute. When the preset signal P is input from the CPU 2, the frequency dividing circuit 8 resets the count value of the clock signal.
[0044]
The clock count circuit 9 counts the current date and time, such as the current date and hour / minute / second, based on the 1-minute signal m input from the frequency divider circuit 8 and outputs it to the CPU 2. The current date and time counted by the clock number circuit 9 is appropriately corrected or corrected under the control of the CPU 2.
[0045]
The switch unit 10 includes, for example, various operation switches such as a switch for automatically performing estimation correction processing (date and time automatic correction switch) and a switch for manually correcting the time. The switch unit 10 outputs operation signals corresponding to inputs from various operation switches to the CPU 2.
[0046]
The display unit 11 is a display device configured with, for example, an LCD (Liquid Crystal Display) or the like, and digitally displays the current date / time and the accuracy of the display date / time based on a display signal input from the CPU 2.
[0047]
Next, the operation of the time data receiving apparatus 1 will be described below using the flowcharts shown in FIGS.
[0048]
When the date / time automatic correction switch (not shown) connected to the switch unit 10 is pressed, the time data correction process is started. At this time, the CPU 2 reads the time data correction program 34 stored in the ROM 3. Then, the time data correction process is started by developing this program in the RAM 4 and executing the program.
[0049]
First, the CPU 2 determines whether or not the current time input from the clock count circuit 9 is 3:00 am (step S2). If it is 3:00 am (step S2: Yes), it will transfer to step S4 and will start a radio wave reception process (step S4). If it is not 3 o'clock in the morning (step S2: No), the process proceeds to step S24.
[0050]
If the CPU 2 determines that it is 3:00 am (step S2: Yes), it reads the radio wave reception program 342 stored in the ROM 3. Then, the radio wave receiving process is started by developing this program in the RAM 4 and executing it (step S4). When the radio wave reception process is started, the CPU 2 outputs a reception start signal C1 to the reception circuit 6 and causes the reception circuit 6 to start radio wave reception (step S202).
[0051]
When the reception start signal C1 is input from the CPU 2, the reception circuit 6 starts radio wave reception. The receiving circuit 6 selects a radio wave that is tuned to a predetermined frequency, that is, a standard radio wave including a standard time code, from the radio waves received by the receiving antenna 5, and starts reception. The receiving circuit 6 extracts the time code TC from the received standard radio wave and outputs it to the CPU 2.
[0052]
The CPU 2 receives the time code TC from the receiving circuit 6, and detects the frame reference marker M in the time code TC (step S204). When the CPU 2 detects the frame reference marker M (step S204: Yes), the process proceeds to step S206. If the frame reference marker M is not detected, the CPU 2 returns to step S204 and detects the frame reference marker M again. . That is, the CPU 2 repeats step S204 until the frame reference marker M is detected.
[0053]
When the frame reference marker M is detected, the CPU 2 extracts time data, accumulated date data, and year data following the frame reference marker M from the time code TC (step S206).
[0054]
The CPU 2 converts the accumulated date data extracted from the time code TC into date data (step S208).
[0055]
Next, the time data is stored in the received time data storage area X1, and the date data and year data are stored in the received date data storage area D1 (step S210).
[0056]
Next, the CPU 2 determines whether or not the frame reference marker M has been detected three times (step S212). If it is determined that the frame reference marker M has been detected three times (step S212: Yes), the process proceeds to step S214. If it is determined that the frame reference marker M has not been detected three times (step S212: No), the process proceeds to step S204. Transition.
[0057]
That is, the CPU 2 repeats the processes in steps S204 to S212 three times in total. By repeating the same process three times, the CPU 2 stores the time data, date data and year data extracted from the time code TC in the reception time / minute data storage areas X1 to X3 and the reception date data storage areas D1 to D3. Also, it is determined that the frame reference marker M has been detected three times (step S212: Yes). Here, the frame reference marker detected at the first reception is set as the first frame reference marker, and then the frame reference marker detected every other minute is set as the second frame reference marker and the third frame reference marker.
[0058]
When determining that the frame reference marker M has been detected three times, the CPU 2 performs consistency determination of the received three data, that is, consistency determination for each frame and consistency determination between the three frames (step S214). .
[0059]
Next, the CPU 2 ends the radio wave reception process, and determines the success or failure of reception based on the result of the consistency determination in step S214 (step S6). That is, when it is determined that there is consistency (step S6: Yes), it is determined that the reception is successful, and the process proceeds to step S8. When it is determined that there is no consistency (step S6: No), the reception is performed. Is determined to have failed, and the process proceeds to step S26.
[0060]
If it is determined that the reception is successful, the CPU 2 resets the continuous reception failure count to “0” (step S8).
[0061]
Next, the CPU 2 reads the time correction program 344 stored in the ROM 3. Then, this program is expanded in the RAM 4 and executed to start time correction processing (step S10).
[0062]
When the time correction process is executed, first, the CPU 2 detects a fourth frame reference marker input from the receiving circuit 6 one minute after the third frame reference marker (step S302). When the fourth frame reference marker is detected (step S302: Yes), the process proceeds to step S304. When the fourth frame reference marker is not detected (step S302: No), the process returns to step S302 again, and the fourth frame is again displayed. Detects the reference marker. That is, the CPU 2 repeats step S302 until the fourth frame reference marker is detected.
[0063]
When the fourth frame reference marker is detected, the CPU 2 detects a pulse signal T1 that rises after 1 second from the rising time of the fourth frame reference marker (time point 1 second after the frame reference marker M in FIG. 7) ( Step S304). When the CPU 2 detects the pulse signal T1 (step S304: Yes), the process proceeds to step S306, and when the pulse signal T1 is not detected (step S304: No), the CPU 2 detects the pulse signal T1 again. That is, the CPU 2 repeats step S304 until the pulse signal T1 is detected.
[0064]
When the CPU 2 detects the pulse signal T1, the CPU 2 stores the current date and time counted by the clock count circuit 9 in the temporary time and date storage area 406 (step S306).
[0065]
Next, the CPU 2 adds the elapsed time (specifically, 1 minute) until the current date and time counted by the clock count circuit 9 is corrected to the reception time data stored in the reception time data storage area X3. The reception time data storage area X3 is rewritten with data (step S308). Then, the current date and time counted by the counting clock circuit 9 is rewritten with the data stored in the reception time data storage area X3 and the reception date data storage area D3 as the current date and time. If the date in the reception date data storage area D3 changes before and after adding the elapsed time to the reception time / minute data, the CPU 2 adds the elapsed date / time (specifically, to the reception date data stored in the reception date data storage area D3). The received date data storage area D3 is rewritten with the date data obtained by adding 1) to the date.
[0066]
By the way, the date / time data rewritten here is data at the time of rising of the fourth frame reference marker as described above. That is, since the data is delayed by 1 second from the pulse signal T1, the CPU 2 outputs the preset signal P to the frequency dividing circuit 8 so that the next 1-minute signal m is output after 59 seconds instead of 60 seconds. Then, the count value of the frequency dividing circuit 8 is forcibly set (reset) to be larger by one second (step S310).
[0067]
And CPU2 complete | finishes a time correction process and displays the precision A on the display part 11 (step S12).
[0068]
Next, the CPU 2 rewrites the previous reception date storage area 404 with the reference reception date (step S14).
[0069]
Next, the CPU 2 rewrites the reference reception date storage area 402 with the current date and time stored in the reception time data storage area X3 and the reception date data storage area D3 (step S16).
[0070]
Next, a unit time correction amount is calculated. The CPU 2 calculates an error generated in the clock circuit 9 by subtracting the elapsed time obtained by subtracting the previous reception date from the reference reception date from the elapsed time obtained by subtracting the reference time from the provisional timing date. By dividing this error by the elapsed time obtained by subtracting the previous reception date and time from the reference reception date and time, the error of the clock count circuit 9 per unit time generated from the previous reception date and time to the reference reception date, that is, the unit time correction amount Is obtained (step S18).
[0071]
Then, the CPU 2 stores the unit time correction amount in the unit time correction amount storage area 410 (step S20).
[0072]
Next, the CPU 2 rewrites the reference time / date storage area 408 with the provisional time / date (step S22).
[0073]
If it is determined in step S6 that reception has failed (step S6: No), the CPU 2 increments the number of consecutive reception failures (step S26).
[0074]
Next, an estimated correction date and time is calculated. The CPU 2 multiplies the unit time correction amount by the elapsed time obtained by subtracting the reference reception date and time from the current date and time stored in the reception time / minute data storage area X3 and the reception date / data storage area D3. Calculate the error that occurred by the date and time. Then, the estimated correction date and time is calculated by subtracting this error from the current date and time counted by the clock count circuit 9. The CPU 2 stores the estimated correction date and time in the reception time data storage area X3 and the reception date data storage area D3 (step S28).
[0075]
Next, the CPU 2 performs time correction processing (step S29), and determines whether or not the number of consecutive reception failures is less than a predetermined number (step S30). Here, since step S29 is the same process as the time correction process (step S10) described above, detailed description thereof is omitted.
[0076]
In step S30, when it is determined that the number of consecutive reception failures is less than the predetermined number (step S30: Yes), the CPU 2 displays the accuracy B on the display unit 11 (step S32).
[0077]
In Step S30, when it is determined that the number of consecutive reception failures is equal to or greater than the predetermined number (Step S30: No), the CPU 2 displays the accuracy C on the display unit 11 (Step S34).
[0078]
After the process of step S22, S32, or S34, the CPU 2 causes the display unit 11 to output the current date and time counted by the clock count circuit 9 (step S24).
[0079]
The CPU 2 repeatedly executes the processes in steps S2 to S24 described above. The time data correction process is executed by the CPU 2 until the output of the date / time automatic correction switch is turned off.
[0080]
As described above, according to the embodiment of the present invention, when the standard radio wave is successfully received, the date and time are corrected by the standard time code. However, when the standard radio wave is not received, the date and time correction by the estimated correction date and time is performed. Do. Therefore, it is possible to prevent an increase in error that occurs in the current date and time counted by the counting clock circuit 9 when the reception of the standard radio wave continuously fails.
[0081]
In the conventional technique, the reception success rate is increased by increasing the number of receptions so that the standard radio wave is received three times a day, and the accuracy of the display time is improved. However, there has been a problem that if the standard radio wave reception fails continuously, the error occurring in the display time is enlarged. According to the embodiment of the present invention, it is possible to maintain the accuracy of the display time more than the conventional technology by the estimation correction, and thus it is possible to reduce the number of receptions per day. Therefore, specifically, by setting the number of receptions per day to one, a power saving design can be realized, and the battery life as a wristwatch can be extended. In this case, the reception interval becomes longer and the reception success rate decreases. However, either the date correction or the date correction is surely performed regardless of the success or failure of the reception. Can be prevented.
[0082]
In addition, the accuracy of the display date and time is clearly indicated by the display unit 11 so that the user can recognize the reliability of the displayed date and time. For example, when the accuracy of the display date and time decreases, a user who has recognized the decrease in accuracy can manually perform radio wave reception processing to correct the time.
[0083]
In the present embodiment, the rank display of accuracy has three levels of A to C, but is not limited to this, and can be changed as appropriate. For example, the number of consecutive reception failures may be counted and the number of times displayed. Specifically, in the case of a digital clock, it is displayed as “Error 2” on the LCD display. In the case of an analog clock, the number of consecutive reception failures is indicated by the hand pointing to 2 o'clock when the push button is pressed. May be specified twice.
[0084]
In this embodiment, the reception time of the standard radio wave is 3 am, but the present invention is not limited to this and can be changed as appropriate. For example, it may be possible to arbitrarily set the reception time according to the user's life rhythm, such as a time zone with little geographic movement or a time zone when a clock is not used.
[0085]
【The invention's effect】
According to the first aspect of the present invention, first, the standard radio wave is received, and the determination unit determines whether the reception is successful. When it is determined that the reception is successful, the time correction means corrects the current time data counted by the time measuring means using the current time data obtained from the standard radio wave. At this time, in preparation for reception failure, the time correction amount calculation means refers to the correction record and calculates the time correction amount. When it is determined that the reception has failed, the correction unit corrects the current time data counted by the time measuring unit using the time correction amount.
Even when reception is unsuccessful, the correction means corrects the time correction amount, so that it is possible to prevent an increase in the error between the current time data counted by the time measuring means and the current time data of the standard radio wave. it can.
[0086]
According to the second aspect of the present invention, since the specifying means clearly indicates whether the time correction by the time adjusting means or the time correction by the correcting means, the user can check whether the displayed time is due to the time correction, The accuracy of the correction can be recognized.
[0087]
According to the third aspect of the invention, the continuous failure indication means clearly indicates whether or not the number of consecutive reception failures is equal to or greater than a predetermined number. The accuracy of whether or not the accuracy is maintained can be recognized.
[0088]
According to the fourth aspect of the present invention, first, the standard radio wave is received, and the determination step determines whether the reception is successful. When it is determined that the reception is successful, the time correction step corrects the current time data counted by the time measuring means using the current date and time data obtained from the standard radio wave. At this time, in preparation for reception failure, the time correction amount calculating step refers to the correction record and calculates the time correction amount. When it is determined that the reception has failed, the correction step corrects the current time data counted by the time measuring means using the time correction amount.
Even when reception is unsuccessful, the time correction amount is corrected by the correction step, so that it is possible to prevent an increase in error between the current time data counted by the time measuring means and the current time data of the standard radio wave. .
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a time data receiving device.
FIG. 2 is a diagram showing a program configuration of a ROM.
FIG. 3 is a diagram illustrating a memory configuration of a RAM.
FIG. 4 is a flowchart for explaining overall processing;
FIG. 5 is a flowchart for explaining radio wave reception processing;
FIG. 6 is a flowchart for explaining time correction processing;
FIG. 7 is a diagram showing a time code.
[Explanation of symbols]
1 Time data receiver
2 CPU
3 ROM
4 RAM
5 Receiving antenna
6 Receiver circuit
7 Oscillator circuit
8 frequency divider
9 Clock circuit
10 Switch part
11 Display

Claims (4)

A time counting means for counting the reference clock signal to obtain current time data;
A radio wave receiving means for receiving a standard radio wave including standard time data at a time correction timing;
Determining means for determining success or failure of reception of the received standard radio wave;
A time correcting unit that corrects current time data measured by the time measuring unit based on standard time data included in the received standard radio wave when it is determined that the determining unit is successful;
Recording means for recording the correction by the time correction means;
When it is determined that the determination unit has failed, referring to the record, the previous time correction amount, the elapsed time from the previous time correction date and time to the previous time correction date and time, and the current time from the previous time correction date and time A time correction amount calculating means for obtaining a time correction amount based on the elapsed time until,
Correction means for correcting current time data timed by the time measuring means by the calculated time correction amount;
A time data receiving device comprising: 2. The time data receiving apparatus according to claim 1, further comprising an explicit unit that clearly indicates whether the time correction at the previous time correction timing is the time correction by the time correction unit or the time correction by the correction unit. The time data receiving device according to claim 1 or 2, further comprising continuous failure indicating means for clearly indicating that the determination by the determining means that reception of a standard radio wave has occurred continuously a predetermined number of times or more. . A time data correction method for correcting current time data received by a standard radio wave including standard time data,
A radio wave receiving step for receiving the standard radio wave;
A determination step for determining success or failure of reception of the received standard radio wave;
A time correction step for correcting current time data measured by the time measuring means based on standard time data included in the received standard radio wave when it is determined that the determination step is successful;
A recording step for recording the correction in this time correction step;
If it is determined that the determination step is unsuccessful, referring to the record, the previous time correction amount, the elapsed time from the previous time correction date and time to the previous time correction date and time, and the previous time correction date and time to the current time A time correction amount calculating step for obtaining a time correction amount based on the elapsed time of
A correction step of correcting current time data timed by the time measuring means by the calculated time correction amount;
The time data correction method characterized by including.

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