JP5359913B2 - Radio receiver and radio clock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio receiver and radio-controlled timepiece appropriately selecting whether receiving operations should be continued or interrupted when a reception environment is not favorable, and reducing current consumption by the useless receiving operations. <P>SOLUTION: The radio receiver is equipped with: a reception control means for operating a receiving section for a series of reception period to output a time code signal from the receiving section in order to determine a time; a first edge numbers determination means for determining whether the number of edges of the time code signal is beyond a first setting range during a first period immediately after starting the reception period; and a second edge numbers determination means (S13, S15) for determining whether the number of edges of the time code signal is beyond a second setting range during a second period after the first period. The reception control means interrupts operations of the receiving section (S18) when it is determined by the first edge numbers determination means or the second edge numbers determination means (S13, S15) that the number of edges is beyond the setting range. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a radio wave receiver and a radio timepiece that receive a standard radio wave and reproduce a time code signal.

  A radio timepiece that receives a standard radio wave including a time code and automatically corrects the time is generally known. In such a radio timepiece, there may be a situation where time code reproduction is not performed accurately in a reception environment where the electric field strength of a standard radio wave is very weak.

  Further, as a conventional technique related to the present invention, Patent Document 1 discloses a technique for selecting a reception frequency by evaluating a reception state based on the number of edges of a standard time radio signal in a radio-controlled timepiece. Further, Patent Document 2 discloses a technique for similarly evaluating a reception state and displaying the evaluation.

Japanese Patent Laid-Open No. 2004-226131 JP 2006-98272 A

  When standard radio wave reception processing is performed in a poor reception environment, the reception operation is performed over a long period of time despite the fact that the time code signal cannot be accurately reproduced and the time cannot be adjusted, and a relatively large amount of current is consumed. May be made. In addition, there is a possibility that the time code is erroneously decoded.

  On the other hand, depending on the reception algorithm that acquires time data from the standard radio wave, if a relatively accurate signal can be received at the start of reception, it may be necessary to perform decoding processing over time even if the reception state deteriorates slightly thereafter. Some time data can be obtained accurately.

  An object of the present invention is to determine a reception environment in which time cannot be determined properly according to a standard radio wave reception algorithm, and to reduce a consumption current due to a useless reception operation and a radio wave reception device. To provide a watch.

In order to achieve the above object, the invention according to claim 1
A receiver that receives and demodulates standard radio waves and outputs a time code signal;
Edge detection means for detecting either one or both edges of the rising edge and falling edge of the time code signal;
Receiving control means for operating the receiving unit in a series of receiving periods for time determination and outputting the time code signal from the receiving unit;
First edge number determination means for determining whether or not the number of edges detected by the edge detection means in a first period immediately after the start of the reception period is out of a first setting range;
Second edge number determination means for determining whether or not the number of edges detected by the edge detection means in a second period after the first period of the reception period is out of a second setting range;
With
The reception control means includes
The operation of the receiving unit is interrupted when it is determined by the first edge number determining means or the second edge number determining means that the number of edges has deviated.

The invention described in claim 2 is the radio wave receiver according to claim 1,
The first setting range is set to be narrower than the second setting range.

The invention described in claim 3 is the radio wave receiving apparatus according to claim 1,
The second setting range is set to be narrower than the first setting range.

The invention according to claim 4 is the radio wave receiving apparatus according to claim 1,
The first period is
It is set to a period in which the second sync point detection process is executed based on the time code signal,
The second period is
The period is set to a period in which minute synchronization point detection or time code decoding processing is executed based on the time code signal.

The invention described in claim 5 is the radio wave receiver according to claim 1,
The first edge number discrimination means includes
Determining whether the number of edges exceeds the upper limit of the first setting range in the middle of the first period;
The second edge number determining means includes
Determining whether the number of edges exceeds the upper limit of the second setting range in the middle of the second period;
The reception control means includes
As soon as the first edge number determining means or the second edge number determining means determines that the number of edges exceeds the upper limit value during the first period or during the second period, the operation of the receiving unit It is characterized by interrupting.

The invention described in claim 6 is the radio wave receiver according to claim 1,
The first edge number discrimination means includes
It is determined whether or not the number of edges falls below a predetermined lower limit value in each partial period obtained by dividing the first period into a plurality of periods,
The second edge number determining means includes
It is determined whether or not the number of edges falls below a predetermined lower limit value in each partial period obtained by dividing the second period into a plurality of parts,
The reception control means includes
As soon as the first edge number determining means or the second edge number determining means determines that the number of edges has fallen below the lower limit value in the middle of the first period or in the second period, the operation of the receiving unit It is characterized by interrupting.

The invention described in claim 7
A time measuring means for measuring time;
Time display means for displaying the time corresponding to the time measured by the time measuring means;
The radio wave receiver according to any one of claims 1 to 6,
Time correcting means for acquiring the current time based on a time code signal sent by the radio wave receiver and correcting the time measured by the time measuring means;
A radio-controlled timepiece characterized by comprising:

  According to the present invention, when the radio wave condition of the standard radio wave is not good, the number of edges of the time code signal is determined as the number of errors, so that the reception operation is interrupted and wasteful current consumption can be reduced. In addition, by setting the determination criterion for the number of edges in the first period immediately after the start of reception and the determination criterion for the number of edges in the second period thereafter to an appropriate value, optimum reception continuation according to the reception algorithm Or it becomes possible to make a judgment of interruption.

1 is a block diagram illustrating an overall configuration of a radio timepiece according to a first embodiment of the present invention. It is a figure explaining the counting method of the rising edge and falling edge of a time code signal. It is a graph which shows the relationship between electric field strength and the count value of an edge. It is a graph which shows the generation probability of the count value of the edge at the time of weak electric field and no signal. It is a 1st part of the flowchart which shows the procedure of the reception control process of 1st Embodiment performed by CPU. FIG. 6 is a second part of a flowchart showing the procedure of the reception control process of the first embodiment. It is the 1st part of the flow chart which shows the procedure of the reception control processing of a 3rd embodiment performed by CPU. FIG. 9 is a second part of a flowchart showing the procedure of the reception control process of the third embodiment.

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

[First Embodiment]
FIG. 1 is a block diagram showing the overall configuration of the radio timepiece 1 according to the first embodiment of the present invention.

  The radio timepiece 1 of this embodiment is, for example, an electronic timepiece that receives a Japanese standard radio wave and demodulates a time code included in the standard radio wave, acquires time information from the time code, and automatically corrects the time. It is. The radio-controlled timepiece 1 includes an antenna 19 that receives a long-wave standard radio wave, a radio wave reception IC (integrated circuit) 20 that serves as a receiving unit that demodulates the received standard radio wave and outputs a time code signal, and the entire timepiece. A central processing unit (CPU) 10 for performing general control, a display means 11 as a time display means including a liquid crystal display for displaying time, an oscillation circuit 14 for generating a predetermined frequency signal, and the frequency signal A clock circuit 15 as a clocking means for counting time, a RAM (Random Access Memory) 12 that provides a working memory space to the CPU 10, and a ROM (Read that stores control programs and control data executed by the CPU 10) Only Memory) 13 and the like. In this embodiment, the CPU 10 constitutes an edge detection means, a reception control means, a first edge number determination means, a second edge number determination means, and a time correction means. Moreover, a radio wave receiving apparatus is comprised by the antenna 19, radio wave receiving IC20, and CPU10 among the said structures.

  The radio wave receiver IC 20 receives a standard radio wave and extracts a raw time code signal having a dull or distorted signal waveform and noise mixed therein, and performs waveform shaping of the raw time code signal to form an external signal. Are provided with a comparator 22 for outputting a time code signal TCO. The receiving circuit 21 is provided with an automatic gain control circuit, and even when the electric field strength of the standard radio wave is very weak or zero, the raw signal changes to a high level and a low level with a certain level difference or more due to external noise or the like. Outputs a time code signal. The comparator 22 compares the raw time code signal with a predetermined threshold value, and outputs a predetermined high level signal or a predetermined low level signal according to the comparison result.

  Therefore, the time code signal TCO output from the radio wave receiving IC 20 has a rising edge or falling edge generation timing compared to the original time code waveform due to weak electric field strength of the standard radio wave or external noise. Are shifted forward and backward, the number of rising edges and falling edges increases due to noise, and rising edges and falling edges in the original time code disappear.

  Further, the radio wave receiving IC 20 performs a receiving operation when the standby signal Stb input from the CPU 10 is set to an invalid level, for example, and the standby signal Stb input from the CPU 10 is set to an effective level. The reception operation is stopped, and the current consumption is reduced to a low level during non-operation.

  The clock circuit 15 normally counts the frequency signal from the oscillation circuit 14 and counts the time, and supplies a timing signal for notifying the CPU 10 of the timing when switching the time display, for example. The CPU 10 realizes the time display according to the clocked time by updating the display content of the display means 11 according to the timing signal. Further, the clock data of the clock circuit 15 can be read and rewritten by the CPU 10.

  The ROM 13 is based on a time display processing program for updating the display time of the display means 11 in correspondence with the time measured by the time measuring circuit 15 or a time code demodulated by receiving a standard radio wave during a predetermined operation period. A reception control processing program for determining the time and correcting the timekeeping time is stored.

  Next, the operation at the time of radio wave reception of the radio timepiece 1 having the above configuration will be described.

  In the radio timepiece 1 of this embodiment, when the time is determined by the time code signal demodulated by receiving the standard radio wave, it is difficult to accurately determine the time in parallel with the time determination process. If the radio wave condition is difficult to determine, the reception control is performed by the CPU 10 so that the radio wave reception operation is interrupted and useless current consumption cannot be continued for a long time.

  Whether or not the radio wave condition is difficult to determine is determined by counting the number of rising and falling edges of the time code signal TCO output from the radio wave receiving IC 20, and setting the number of edges in a predetermined period in advance. It is based on whether or not it is within the range.

  Specifically, first, an early termination determination process is performed in a first period of 15 seconds from the start of reception. That is, the number of edges in the first period is counted to determine whether it exceeds the first set value (for example, 62), and if it exceeds, the number of edges (number of errors) that can be considered difficult to acquire time data based on the time code. The radio wave reception is interrupted by determining that it has become. That is, in this embodiment, the range of 0 to 61 edges for 15 seconds is the first setting range that is not determined as the number of errors.

  In the first period, the second synchronization process is performed in which the edge appearing at intervals of 1 second among the rising edges of the time code signal TCO is identified in the time determination process, thereby detecting the second synchronization point (comma zero second point). It is a period.

  Subsequently, when it is determined in the early termination determination process that the reception is continued, the middle-term termination determination process is performed in the second period of 15 seconds from the end point of the first period. That is, the number of edges in this second period is counted whether it exceeds a second set value (for example, 77), and if it exceeds, the number of edges (number of errors) that can be regarded as difficult to acquire time data based on the time code. The radio wave reception is interrupted by determining that it has become. That is, in this embodiment, the range of 0 to 77 edges for 15 seconds is the second setting range that is not determined as the number of errors.

  Further, the above-described medium-term end determination process is repeatedly executed a plurality of times every 15 seconds as long as reception is continued.

  Each second period in which this medium-term end determination process is executed a plurality of times includes a process of detecting a minute synchronization point (00 second point) in which the position marker and the marker pulse continue from the time code signal TCO in the time determination process, A decoding process that decodes the time code represented by the time code signal TCO to obtain time data indicating the date and hour / minute digit value, and performs a parity check to check whether there is an error in the time code. This is a period during which a minute synchronization / decoding process is executed.

  As described above, the first set value and the second set value, which are the determination criteria as to whether or not the number of edges has reached the number of errors, in the above-described early end determination process and medium-term end determination process are 62 as described above. The latter is set to a value different from 77. Since the number of edges detected in 15 seconds in an ideal time code signal is 30, the former is more severe than the latter in the first set value and the second set value (the number of errors is the same even in the same radio wave condition). (It is easy to determine).

  FIG. 2 is a diagram illustrating a method of counting the rising edge and falling edge of the time code signal TCO.

  As shown in FIG. 2, an ideal time code signal TCO includes a pulse signal representing one code per second, and the type of code is indicated by the high-level pulse width of this pulse signal. Further, as shown in FIG. 2, the time code signal TCO output from the radio wave receiving IC 20 is a signal binarized into a high level “+1” and a low level “−1” by the comparator 22.

  Therefore, the CPU 10 samples the time code signal TCO at a period much shorter than 1 second, thereby causing the rising edge Eh that changes from the low level to the high level and the falling edge El that changes from the high level to the low level. Can be detected. Alternatively, the CPU 10 inputs the time code signal TCO as an interrupt signal, and generates an interrupt by a signal that changes from a low level to a high level and from a high level to a low level, whereby the rising edge Eh and the falling edge El Can be detected.

  Further, in an ideal time code signal TCO that is not affected by noise or the like, the number of edges Eh and El is detected in two per second and 30 in 15 seconds.

  FIG. 3 is a graph showing the relationship between the electric field strength of the standard radio wave and the edge count value. In the figure, the solid line indicates the count value of the edge for 15 seconds in the ideal time code signal. Further, the rhombus plot line indicates the minimum value of the count value in the simulation result obtained by counting the edge for 15 seconds while changing the electric field intensity of the standard radio wave from small to large. The square plot line indicates the average value of the count values in the simulation result, and the triangle plot line indicates the maximum value of the count value in the simulation result.

  As shown in the range on the right side of the graph of FIG. 3, when the electric field strength of the standard radio wave is large, the time code signal TCO that is close to ideal is output, so the edge count value for 15 seconds approaches the ideal value “30”. The variation in the count value is also reduced.

  On the other hand, as shown in the left range of the graph of FIG. 3, when the electric field strength of the standard radio wave decreases, an edge due to external noise or the like is added to the time code signal TCO. Becomes a value larger than the ideal value “30”. In addition, the variation of the count value also increases. Furthermore, in the range where the electric field strength is very small, even the minimum count value is larger than the ideal value “30”.

  FIG. 4 is a graph showing the occurrence probability of the edge count value when the electric field is weak and when there is no signal.

  In FIG. 4, a square plot line indicates an edge for 15 seconds when a simulation is performed many times when a standard electric wave with a weak electric field that minimizes the electric field strength is obtained in a range in which time data can be acquired by normal decoding processing. The occurrence rate of the count value of the number (the numerical value on the vertical axis is a value proportional to the occurrence rate). A rhombus plot line represents a simulation result of a large number of times in the weak electric field in a normal distribution. This normal distribution is created on the basis of the average value and standard deviation of the count values of a large number of simulation results.

  In FIG. 4, the circle plot line indicates the occurrence rate of the count value of the number of edges for 15 seconds when the reception processing simulation is performed many times in a no-signal state where the electric field strength of the standard radio wave is zero. Yes. The triangular plot line represents the result of many simulations with no signal in a normal distribution. This normal distribution is created on the basis of the average value and standard deviation of the count values of a large number of simulation results.

  In FIG. 4, a dotted line f2 represents a count value corresponding to a point of + 3σ (σ is a standard deviation) from the average value of the normal distribution at the time of the weak electric field. In the radio wave receiving IC 20 of this embodiment, the count value “ 77 ". A dotted line f1 represents a count value corresponding to a point of −3σ (σ is a standard deviation) from the average value of the normal distribution at the time of no signal. In the radio wave reception IC 20 of this embodiment, the count value is “62”. Yes.

  As shown in FIG. 4, the count value of the edge for 15 seconds is mainly in the range of “45 to 68” at the time of weak electric field from which time data can be acquired and in the range of “72 to 102” at the time of no signal. It can be seen that it fluctuates.

  Therefore, if the minimum range is obtained under the condition that the count value at the time of the weak electric field is hardly excluded, the range within the count value “77” corresponding to the point of + 3σ from the average value at the time of the weak electric field is obtained. Further, if the maximum range is obtained under the condition that the count value at the time of no signal is almost excluded, a range within the count value “62” corresponding to the point of −3σ from the average value at the time of no signal is obtained.

  That is, the first set value “62”, which is a criterion for determining whether or not the number of edges has reached the number of errors in the early termination determination process described above, is mostly in the case of a weak electric field within a range where time information can be acquired. It is set to a value that is not determined as the number of errors with the probability of.

  On the other hand, the second set value “77”, which is a criterion for determining whether or not the number of edges has reached the number of errors in the above-described medium-term end determination processing, is almost the number of errors in the case of a weak electric field where time information can be acquired. In the case of no signal when the time information is not acquired, the value is set to a value that is determined as the number of errors with the most probability.

  With such a setting, a slightly severe end determination is performed during the second synchronization process by the early end determination process, and then a slightly sweet end determination process is performed in the minute synchronization / decode process by the medium end determination process. ing. Such a two-stage end determination process based on different determination criteria corresponds to the following design concept of the time determination process. That is, according to the time determination processing algorithm of this embodiment, the second synchronization processing is performed relatively accurately by the time code signal TCO whose degree of deterioration is not so severe. It is designed so that necessary time data can be accurately obtained even with a deteriorated time code signal by processing with a little time while eliminating the influence. Therefore, by the end determination process using the two-stage determination criterion as described above, the reception process is continued to the end until the last deterioration state where time data can be acquired even if the time code signal TCO is deteriorated. In a very deteriorated state in which data cannot be acquired, radio wave reception is interrupted so that useless current consumption does not occur.

  FIG. 5 and FIG. 6 show a flowchart of a reception control process in which the standard radio wave is received to acquire time data and the interruption and continuation of the reception operation are determined in the middle.

  This reception control process is started based on the establishment of a predetermined condition, for example, when a predetermined time for executing time correction using a standard radio wave is reached, or when a time correction using a standard radio wave is requested from another program. Is done. Here, it is assumed that the time counting time of the time measuring circuit 15 is started from the timing of “00 seconds”.

  When the reception control process is started, first, the CPU 10 sets the standby signal Stb of the radio wave reception IC 20 to an invalid level and starts the radio wave reception operation (step S1). Then, the second synchronization detection process for detecting the second synchronization point by inputting the time code signal TCO from the radio wave receiving IC 20 is started (step S2). In this second synchronization detection process, a second synchronization point (comma zero second point) is obtained by finding an edge generated at intervals of 1 second among rising edges of the time code signal TCO and adding a predetermined offset to this timing. These are executed in parallel with the subsequent steps S3 to S8.

  Next, the CPU 10 proceeds to a step of early termination determination processing. First, a variable Edge for counting the number of edges of the time code signal TCO is initialized to zero (step S3), and it is determined whether or not there is an edge of the time code signal TCO (step S4: edge detection means). Edge is incremented by “1” (step S5), and the process proceeds to step S6. If not, the process proceeds to step S6.

  In step S6, the CPU 10 determines whether the value of the variable Edge (hereinafter referred to as the edge number Edge) exceeds the first set value “62” (step S6: first edge number determining means). If it exceeds, since it can be determined that the edge number Edge has reached the number of errors even during the early end determination process for 15 seconds, the process jumps to step S18 in order to interrupt radio wave reception. On the other hand, if it does not exceed the first set value, the process proceeds to the next to determine whether the time measured by the time measuring circuit 15 is “15 seconds”. If it is not yet “15 seconds”, the process returns to step S4. On the other hand, when “15 seconds” is reached, it is the end timing of the early end determination process for 15 seconds, and the process proceeds to step S8. Note that the algorithm for time determination processing is designed so that the second synchronization processing is completed in 15 seconds.

  When the process proceeds to step S8, it is determined whether or not the edge number Edge counted for 15 seconds from the start of reception exceeds the first set value “62” (step S8: first edge number determining means). And if it exceeds, it will be judged that it is the number of errors, and it jumps to step S18 in order to interrupt radio wave reception. On the other hand, if the first set value is not exceeded, the process proceeds to step S9 while radio wave reception continues.

  That is, the loop processing of steps S4 to S7 is repeatedly executed within 15 seconds from the start of radio wave reception, and the edge number Edge of the time code signal TCO during that time is counted. Then, at the end of 15 seconds, it is confirmed whether the edge number Edge has reached the error number. If the error number is reached, the radio wave reception is interrupted, and if the error number is not reached, the radio wave reception is continued. . Further, if the edge number Edge exceeds the first set value even during the early termination determination process, it is determined by the determination process of step S6, and radio wave reception is immediately interrupted.

  When the process proceeds to step S9, first, the CPU 10 starts detection of the minute synchronization point (00 second point) from the time code signal TCO, and decodes the time code to acquire time data (step S9). This synchronization / decoding process is executed in parallel with the subsequent steps S10 to S17.

  Next, the CPU 10 resets the edge number Edge of the time code signal TCO to “0”, and updates the variable M (initial value “0”) indicating the number of executions of the medium-term end determination process by “+1” (step S10). .

  Subsequently, the CPU 10 determines whether or not there is an edge of the time code signal TCO (step S11: edge detection means). If there is, the CPU adds 10 to the edge number Edge (step S12), and proceeds to step S13. If not, the process proceeds to step S13.

  In step S13, the CPU 10 determines whether the edge number Edge has exceeded the second set value “77” (step S13: second edge number determining unit). Even during the process, it can be determined that the edge number Edge has reached the error number, so the process jumps to step S18 to interrupt the radio wave reception. On the other hand, if the second set value is not exceeded, the process proceeds to the next and the time counting seconds of the time measuring circuit 15 are multiples of 15 such as “30 seconds”, “45 seconds”, “00 seconds”, “15 seconds”. Is determined (step S14). As a result, if these seconds are not reached, the process returns to step S11. On the other hand, if it is these second numerical values, it is the end timing of the medium-term end determination process for one 15-second period, so the process proceeds to the next.

  Next, it is determined whether or not the edge number Edge counted in the previous 15 seconds has exceeded the second set value “77” (step S15: second edge number determination means). And if it exceeds, it will be judged that it is the number of errors, and it jumps to step S18 in order to interrupt radio wave reception. On the other hand, if the second set value is not exceeded, the process proceeds to step S16 while the radio wave reception is continued.

  That is, the loop processing of steps S11 to S14 is repeatedly executed during 15 seconds of the medium-term end determination processing, and the edge number Edge of the time code signal TCO during that time is counted. Then, at the end of 15 seconds, it is confirmed whether the edge number Edge has reached the error number. If the error number is reached, the radio wave reception is interrupted, and if the error number is not reached, the radio wave reception is continued. . Further, if the edge number Edge exceeds the second set value even during the mid-term termination determination process, it is determined by the determination process of step S13, and radio wave reception is immediately interrupted.

  When the process proceeds to step S16, it is determined whether or not the number of executions M of the medium-term end determination process has reached the predetermined number MAX (step S16). If not, the process returns to step S10, and if it has reached, the process proceeds to the next step S17. Transition. With this process, the medium-term termination determination process is executed a predetermined number of times every 15 seconds after the early termination determination process.

  As a result, when the predetermined number of medium-term end determination processes are completed and the process proceeds to step S17, the CPU 10 waits until the remaining time code decoding process is completed with respect to the process of the end determination process. Is completed, the timing data of the timing circuit 15 is corrected based on the time data (step S17). Then, the process proceeds to step S18.

  In step S18, the CPU 10 sets the standby signal Stb of the radio wave receiving IC 20 to an effective level and stops the receiving operation (step S18). Then, this reception control process ends.

[Second Embodiment]
In the radio timepiece according to the second embodiment, the first set value, which is a criterion for determining whether or not the number of edges has reached the number of errors in the early termination determination process, and whether or not the number of edges has reached the number of errors in the medium-term termination determination process. The second set value, which is a criterion for determining whether or not, is different from that of the radio timepiece 1 of the first embodiment. The description of the same configuration as that of the first embodiment is omitted.

  In the radio timepiece of the second embodiment, the first set value is set to “77” and the second set value is set to “62”. That is, in the early termination determination process and the middle termination determination process, the latter is a setting value that is stricter than the former (easily determined as the number of errors even in the same radio wave situation).

  With such a setting, an intermediate end determination is performed by the early end determination process during the second synchronization process. In other words, when there is no signal when time data cannot be acquired, the number of errors is determined with a large probability, and the reception operation is interrupted. When there is a weak electric field where time data can be acquired, the number of errors hardly occurs. An end determination is made.

  Further, during the subsequent synchronization / decoding process, a slightly strict end determination is performed by the medium-term end determination process. In other words, in the case of a weak electric field where time data can be acquired, it is determined that the reception operation is continued without the number of errors with a large probability, and the reception operation is interrupted with a small probability with the number of errors. Is done.

  Such end determination processing corresponds to the design concept of time determination processing as follows. That is, the time determination processing algorithm of this embodiment performs time determination in a short time when the radio wave condition is relatively good, and gives up acquisition of time data when the probability that time determination cannot be performed is relatively high. Designed. Therefore, if it becomes difficult to obtain time data in the minute synchronization / decoding process due to the two-step end determination process using the above-described determination criteria, the reception of radio waves is immediately interrupted and wasteful current consumption occurs. It is surely avoided.

[Third Embodiment]
The radio timepiece of the third embodiment differs from the first and second embodiments in that a lower limit value of the number of edges is provided as a criterion for determining the number of edges as the number of errors in the early termination determination process and the medium-term termination determination process. . Therefore, the description of the configuration different from the first and second embodiments is omitted.

  As shown in FIG. 3, when the electric field intensity of the standard radio wave decreases, the edge count value becomes larger than the ideal value. However, when the radio wave condition is abnormal, the circuit of the radio wave reception IC 20 operates abnormally, and the time code signal TCO is kept at a constant level for a long period without being affected by the standard radio wave or external noise. Sometimes done. In the third embodiment, this abnormal output is detected at an early stage to stop the radio wave receiving operation.

  7 and 8 show a flowchart of the reception control process of the third embodiment.

  When the reception control process of the third embodiment is started, first, the CPU 10 sets the standby signal Stb of the radio wave receiving IC 20 to an invalid level and starts an operation of radio wave reception (step S21). Then, the second synchronization detection process for detecting the second synchronization point by inputting the time code signal TCO from the radio wave receiving IC 20 is started (step S22).

  Next, the CPU 10 proceeds to a step of early termination determination processing. First, a variable Edge for counting the number of edges of the time code signal TCO is initialized to zero (step S23), and it is determined whether or not there is an edge of the time code signal TCO (step S24: edge detecting means). The number Edge is incremented by “1” (step S25), and the process proceeds to step S26. If there is not, the process proceeds to step S26 as it is.

  In step S26, the CPU 10 determines whether the timekeeping seconds of the timekeeping circuit 15 are “5 seconds”, “10 seconds”, and “15 seconds”, and if not, returns to step S24. On the other hand, if the timed seconds are these values, the process proceeds to the next, and it is determined whether or not the edge number Edge counted in the immediately preceding 5 seconds is equal to or lower than the lower limit value (for example, 2) (step S27: first edge number). Discrimination means). And if it is below a lower limit, in order to interrupt radio wave reception, it jumps to Step S40.

  On the other hand, if it is larger than the lower limit value, it proceeds to the next, and it is determined whether or not the time counting second of the time measuring circuit 15 is “15 seconds” (step S28). As a result, if it is not yet “15 seconds”, the process returns to step S24. On the other hand, if it is “15 seconds”, it is the end timing of the early end determination process for 15 seconds, so the process proceeds to the next to make an early end determination (step S29: first edge number determination means). That is, in step S29, it is determined whether the number of edges Edge exceeds the first set value “62”.

  As a result, if it exceeds the first set value, it is determined that the number of errors is reached, and the process jumps to step S40 to interrupt radio wave reception. On the other hand, if the first set value is not exceeded, the process proceeds to step S30 while radio wave reception continues.

  That is, the loop process of steps S24 to S28 is repeated during the 15-second early end determination process, the number of edges Edge is counted, and it is determined whether the number of errors is reached at the end of the early end determination process. It has come to be. In addition, by the processes in steps S26 and S27 described above, it is determined whether the number of edges counted during the 15-second early end determination process is less than or equal to the lower limit value (for example, 2) for 5 seconds, If it is equal to or lower than the lower limit value, the number of errors is assumed, and radio wave reception is interrupted even during the early termination determination process. That is, the number of edges counted only in each period in each period of 0 second to 5 seconds, 5 seconds to 10 seconds, and 10 seconds to 15 seconds in the 15 seconds of the early termination determination process If Edge is less than or equal to the lower limit value (for example, 2), radio wave reception is interrupted as the number of errors.

  When the process proceeds to step S30, first, the CPU 10 starts detection of the minute synchronization point (00 second point) from the time code signal TCO and decodes the time code to acquire time data (step S30).

  Next, the CPU 10 resets the edge number Edge of the time code signal TCO to “0”, and updates the variable M (initial value “0”) indicating the number of executions of the medium-term end determination process by “+1” (step S31). .

  Subsequently, the CPU 10 determines whether or not there is an edge of the time code signal TCO (step S32: edge detection means), and if there is, adds the edge number Edge by “1” (step S33), and next step S34. If not, the process proceeds to step S34 as it is.

  After shifting to step S34, the CPU 10 determines whether or not the time measured by the time counting circuit 15 is divisible by “5” (step S34). If not, the process returns to step S32 while this value is reached. Then, it is determined whether or not the edge number Edge counted in the immediately preceding 5 seconds is equal to or lower than a lower limit value (for example, 2) (step S35: second edge number determining means).

  If the result of determination in step S35 is below the lower limit value, the process jumps to step S40 to interrupt radio wave reception. On the other hand, if it is not less than the lower limit, the process proceeds to the next, and it is determined whether or not the time measured by the time measuring circuit 15 is divisible by “15” (step S36). If not, the process proceeds to step S32. Return.

  On the other hand, as a result of the determination process in step S36, if the time measured is a value divisible by “15”, it indicates the passage of one period of the medium-term end determination process. It is determined whether the edge number Edge exceeds the second set value “77” (step S37: second edge number determining means). If it exceeds, it indicates that the edge number Edge has reached the number of errors, so the process jumps to step S40 in order to interrupt radio wave reception.

  If it is determined in step S37 that the edge number Edge does not exceed the second set value “77”, whether the number of times of the medium-term end determination process reaches the predetermined number MAX by proceeding to the next while continuing radio wave reception. It discriminate | determines (step S38). As a result, if not reached, the process returns to step S31, and if reached, the process proceeds to step S39.

  That is, by repeating the loop process of steps S31 to S38 a predetermined number of times, the medium-term end determination process is executed a plurality of times every 15 seconds while radio wave reception is continued. In addition, the processing in steps S34 and S35 confirms whether the number of edges is less than or equal to the lower limit value every 5 seconds during each medium-term end determination process. Radio reception is interrupted immediately even in the middle.

  In step S39, the CPU 10 stands by until the time code decoding process is completed with respect to the end determination process. When the decoding process is completed, the CPU 10 corrects the timing data of the timing circuit 15 based on the time data ( Step S39). Then, the process proceeds to step S40.

  In step S40, the CPU 10 sets the standby signal Stb of the radio wave receiving IC 20 to an effective level and stops radio wave reception (step S40). Then, this reception control process ends.

  In the third embodiment, the first set value for determining the number of errors in the early end determination process is “62”, and the second set value for determining the number of errors in the medium end determination process is “77”. However, these set values may be changed to the values of the second embodiment.

  As described above, according to the radio timepiece of the first to third embodiments and the radio wave receiver mounted thereon, the early end determination process is performed immediately after the start of radio wave reception, and the number of edges of the time code signal TCO is increased. If the number of errors exceeds the first set value, radio wave reception is interrupted early. Even if it is determined that the radio wave reception is continued in the early termination determination process, the radio wave reception is interrupted if the mid-term termination determination is performed after that and the number of edges exceeds the second set value and the number of errors. Therefore, the first set value and the second set value are set to the degree of deterioration of the time code signal TCO allowed in the initial stage of the time determination process and the time code signal TCO allowed in the middle stage of the time determination process. By appropriately setting according to the degree of deterioration, radio wave reception is interrupted when it is difficult to determine the time, and generation of useless current consumption can be prevented. It is also possible to prevent erroneous time data from being acquired by an unreasonable decoding process.

  Further, as shown in the first embodiment, the error determination of the number of edges in the early end determination process is made relatively strict (the first setting value is “62”), and the error of the number of edges in the medium end determination process is made. By making the determination relatively loose (the second set value is “77”), it is possible to determine whether to continue or interrupt the radio wave reception that corresponds well to the time determination process designed as follows. That is, it is possible to realize an optimum end determination process for the time determination process designed to remove the influence of noise and perform an accurate time determination even when a certain amount of time is taken in the minute synchronization / decoding process.

  Further, as shown in the second embodiment, the error determination of the number of edges in the early end determination process is set to a medium severity (the first set value is “77”), and the number of edges in the medium end determination process is determined. By strict error determination (the second set value is “62”), it is possible to determine whether to continue or interrupt radio wave reception that is well suited to the time determination process designed as follows. In other words, optimal end determination processing is performed for time determination processing designed to quickly detect second synchronization and minute synchronization and decode time code on the assumption that the time code signal is not severely degraded. realizable.

  Further, as shown in the first to third embodiments, the early termination determination process is executed during the second synchronization detection process period, and the intermediate termination determination process is performed during the minute synchronization / decoding process period. When the degree of deterioration of the time code signal TCO allowed for the detection of the synchronization and the detection of the minute synchronization and the decoding of the time code are different, it is possible to cope with them.

  In addition, as shown in the first embodiment, not only whether the number of edges is the number of errors at the end of each end determination process, but also when the number of errors is reached even during each end determination process In this case, since radio wave reception is interrupted promptly, wasteful current consumption can be further reduced.

  Further, as shown in the third embodiment, during each end determination process, it is determined whether the number of edges is not less than the lower limit value every 5 seconds. Since radio wave reception is interrupted promptly even during processing, radio waves can be quickly responded to abnormal operation of the receiving circuit that the time code signal TCO has reached a certain level due to abnormal radio wave reception. Reception can be interrupted. Thereby, wasteful current consumption can be further reduced.

  Note that the present invention is not limited to the radio timepiece of the above embodiment and the radio wave receiver mounted thereon, and various modifications can be made. For example, in the above-described embodiment, the first setting value that is a criterion for determining whether to interrupt radio wave reception in the early termination determination process, and the second setting value that is a criterion for determining whether radio wave reception is interrupted in the medium term termination determination process Although two patterns are shown, for example, the first set value is “62”, the early end determination process is set to be a strict setting, and the second set value is set to a value smaller than “62”. Can be set to a stricter setting. In this case, it is possible to realize an end determination process that places more emphasis on reducing unnecessary current consumption. The first set value and the second set value may be the same value.

  In the above embodiment, the average value of normal distribution in the weak electric field + 3σ value “77” including almost the count value of the edge in the weak electric field as the value of the first setting value and the second setting value, and no signal The example of applying the average value of −3σ of the normal distribution at the time of no signal “62” which can almost exclude the count value of the edge at the time is shown, but the average ± 2σ value of each normal distribution can be used, The set value may be obtained by logic. Even if the first set value and the second set value are obtained by the logic as described above, the numerical value varies depending on the internal configuration of the radio wave receiving IC 20.

  In addition, the influence of external noise or the like of the radio wave reception IC 20 varies depending on external factors such as the remaining battery level (decrease in operating voltage), aging and temperature. In addition, external noise varies depending on the time, such as less noise at night. Therefore, for example, the first set value and the second set value may be dynamically changed according to the previous reception result (whether or not the time can be determined), the remaining battery level, the current time, and the like. .

  Further, in the above-described embodiment, the period for counting the number of edges in the early termination determination process and the medium-term termination determination process is 15 seconds, but this period can be changed as appropriate, such as 10 seconds or 20 seconds. Further, the period length of the early end determination process and the period length of the medium period end determination process may be made different from each other. In this case, the degree of severity of the first set value and the second set value can be compared by dividing the set value by the period length and normalizing.

  In the above embodiment, only the first set value and the second set value, which are the upper limit values, are set as a setting range in which the number of edges is not determined to be the number of errors at the end of each period of the early end determination process and the intermediate end determination process. Although an example has been shown, a lower limit value that excludes an abnormal operation of the receiving means due to abnormal radio wave reception may be set.

  In the above embodiment, both the rising edge and the falling edge are counted, but only one of them may be counted. In addition, in the above embodiment, the number of edges is counted for the time code signal TCO having a waveform formed by the comparator 22, but the number of edges is detected by detecting a level change in response to a raw time code signal that is not waveform-shaped. You may make it count. In addition, the detailed configuration and the detailed method shown in the embodiments can be appropriately changed without departing from the spirit of the invention.

1 Radio clock 10 CPU
11 Display means 12 RAM
13 ROM
15 Timekeeping circuit 19 Antenna 20 Radio wave receiving IC
21 Receiving circuit 22 Comparator Stb Standby signal TCO Time code signal Eh Rising edge El Falling edge

Claims (7)

A receiver that receives and demodulates standard radio waves and outputs a time code signal;
Edge detection means for detecting either one or both edges of the rising edge and falling edge of the time code signal;
Receiving control means for operating the receiving unit in a series of receiving periods for time determination and outputting the time code signal from the receiving unit;
First edge number determination means for determining whether or not the number of edges detected by the edge detection means in a first period immediately after the start of the reception period is out of a first setting range;
Second edge number determination means for determining whether or not the number of edges detected by the edge detection means in a second period after the first period of the reception period is out of a second setting range;
With
The reception control means includes
The radio wave receiver characterized in that the operation of the receiving unit is interrupted when it is determined by the first edge number determining means or the second edge number determining means that the number of edges has deviated.   The radio wave receiver according to claim 1, wherein the first setting range is set to a range narrower than the second setting range.   The radio wave receiver according to claim 1, wherein the second setting range is set to a range narrower than the first setting range. The first period is
It is set to a period in which the second sync point detection process is executed based on the time code signal,
The second period is
2. The radio wave receiving apparatus according to claim 1, wherein the radio wave receiving apparatus is set to a period in which a minute synchronization point detection or a time code decoding process is executed based on the time code signal. The first edge number discrimination means includes
Determining whether the number of edges exceeds the upper limit of the first setting range in the middle of the first period;
The second edge number determining means includes
Determining whether the number of edges exceeds the upper limit of the second setting range in the middle of the second period;
The reception control means includes
As soon as the first edge number determining means or the second edge number determining means determines that the number of edges exceeds the upper limit value during the first period or during the second period, the operation of the receiving unit The radio wave receiving apparatus according to claim 1, wherein the radio wave receiving apparatus is interrupted. The first edge number discrimination means includes
It is determined whether or not the number of edges falls below a predetermined lower limit value in each partial period obtained by dividing the first period into a plurality of periods,
The second edge number determining means includes
It is determined whether or not the number of edges falls below a predetermined lower limit value in each partial period obtained by dividing the second period into a plurality of parts,
The reception control means includes
As soon as the first edge number determining means or the second edge number determining means determines that the number of edges has fallen below the lower limit value during the first period or during the second period, the operation of the receiving unit The radio wave receiving apparatus according to claim 1, wherein the radio wave receiving apparatus is interrupted. A time measuring means for measuring time;
Time display means for displaying the time corresponding to the time measured by the time measuring means;
The radio wave receiver according to any one of claims 1 to 6,
Time correcting means for acquiring the current time based on a time code signal sent by the radio wave receiver and correcting the time measured by the time measuring means;
A radio timepiece characterized by comprising.

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