JP3329065B2 - Clock device with time calibration function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timepiece with a time calibration function, which detects a time signal included in a broadcast signal and calibrates the current time.

[0002]

2. Description of the Related Art A video cassette recorder or the like is equipped with a clock device for displaying the current time. This clock device is calibrated at an accurate time by an internal clock provided in the device.

[0003] As a method of calibrating the time with an internal clock,
As a time signal detection means, an analog filter tuned to the frequency of the time signal, a microcomputer (hereinafter referred to as a microcomputer), a DSP (Digital Signal Processor)
For example, a method of directly sampling a signal is used.

In the timepiece device for calibrating the time as described above, a time signal pattern, that is, three forecast sound signals and 1
The time signal is detected by detecting the temporal arrangement of the two hourly sound signals. Note that the forecast sound signal is 440H which is generated 3, 2, and 1 second before the hour in the hourly signal.
It is a time signal of z. The hour sound signal is an 880 Hz time signal emitted at the hour.

[0005]

By the way, when detecting the temporal arrangement of three forecast sound signals and one hour sound signal, in broadcast, an audio signal component having the same frequency as the forecast sound signal and the hour sound signal is detected. Exists with a considerable probability, and this audio signal component may be detected in the same pattern as the time signal. For this reason, the audio signal component may be erroneously determined to be a time signal, and the clock calibration function may malfunction.

That is, in the time signal detection method in which the same component as the forecast sound signal is detected from the audio signal of the broadcast and the signal is regarded as a time signal according to the detection interval, malfunction may occur. This is because there is no way to determine whether the detected signal is a forecast sound signal of a time signal or an audio signal having the same frequency component as the forecast sound signal, which has no meaning as a time signal at all.

Accordingly, an object of the present invention is to provide a timepiece device capable of accurately detecting a time signal and reducing malfunctions of time calibration.

[0008]

According to the present invention, a broadcast signal is transmitted.
Receiving means for receiving, the components of the specific frequency corresponding to the time signal contained in the broadcast signal <br/> No. received by receiving means
Specific frequency detection means for detecting a signal , and specific frequency detection
The time signal from a component in a specific frequency detected by means
Extraction means and time signal extraction from specific frequency components
If so, the time of the internal clock and the time obtained from the time signal
Means for obtaining information on the time difference between
The time between the time of the clock and the time obtained from the time signal
Means for holding the average deviation and the time of the internal clock this time
And the time difference from the time obtained from the time signal
Between the time of the internal clock up to and the time obtained from the time signal
The deviation from the average value of the time deviation is within the predetermined tolerance.
And the time and time of the built-in clock this time
The time difference from the time obtained from the information signal and the last time
Time between the time of the internal clock and the time obtained from the time signal
Deviation from the average value of the typical deviation is within the specified tolerance
For example, the internal clock can be compared based on the time obtained from the time signal.
Performs the correction and obtains the time and time signal from the built-in clock this time.
And the time of the internal clock up to the last time
Of the time difference between the time and the time obtained from the time signal
If the error is not within the specified tolerance, the internal clock
Means for controlling so as not to perform correction.

[0009]

The specific frequency is detected from the signal received by the broadcast receiving section by the tone decoder. The detection output of the tone decoder 5 is supplied to the microcomputer 7. The microcomputer 7 determines whether or not the signal detected this time is a time signal based on the time difference between the built-in clock unit and the time signal when the time was previously calibrated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a timepiece apparatus to which the present invention is applied will be described below with reference to the drawings. FIG. 1 is a system block diagram of a timepiece apparatus for detecting a forecast sound of a time signal, to which the present invention is applied. The clock device includes a broadcast receiving unit 1, a specific frequency detecting unit 4, a time signal coincidence detecting unit, a time calibrating unit, a built-in clock unit, and a timer unit 6. The broadcast receiving unit 1 includes an antenna 2 and a tuner 3. The specific frequency detector 4 is a tone decoder 5 that detects a forecast sound signal. Time signal match detection unit, time calibration unit,
The built-in clock section and the timer section 6 are constituted by a microcomputer 7.

A broadcast is received by the antenna 2, and a desired broadcast station is selected by the tuner 3. The audio signal of the station is supplied to the tone decoder 5. Note that the tone decoder 5 is set to detect a signal having the same frequency as the forecast sound signal. The output of the tone decoder 5 is supplied to the microcomputer 7. When the time signal coincidence detecting section of the microcomputer 7 detects that the input signal is a time signal, the time of the internal clock section is calibrated by the time calibrating section of the microcomputer 7. The tone decoder 5 is basically a PLL circuit, and can function equivalently to an analog filter having a high Q, and
It can be configured relatively easily.

The operation time of the time signal coincidence detection unit in the microcomputer 7 is determined by the elapsed time from the previous time calibration (when a time signal was detected) to the present. Only when the input signal is regarded as a time signal during this operation time, the time of the built-in clock section is calibrated.

For example, assuming that the time calibration operation is performed once a day at a predetermined time, 24 hours have passed since the last time the time was calibrated. If the accuracy of the built-in clock unit in the microcomputer 7 is ± 30 seconds per month, the error per day can be considered to be about ± 1 second on average.
Therefore, even if a signal having the same frequency component as the time signal is detected at a time greatly deviated from the time difference by referring to the information on the deviation of the built-in clock unit when the time signal is detected from the start of the clock operation, It can be determined that the signal is not a time signal. By applying this, for example, if the average value of the time difference of the built-in clock with respect to the time signal when the time signal was detected in the past is held, the signal received at a time away from the time signal is It can be determined that it is not a signal.

FIG. 2 is a diagram showing the relationship between the time signal and the output of the tone decoder. FIG. 2A shows the waveform of the time signal in Japan, and FIG. 2B shows the output waveform of the tone decoder when the time signal is used as an input signal. The output waveform of the tone decoder shown in FIG. 2B does not need to be the time signal shown in FIG. 2A. That is, if the input signal contains the same frequency component as the signal shown in FIG.
A waveform like B is obtained. In order to prevent a signal other than a time signal from being detected as a time signal, it is effective to use information on a time lag at the time of detection in the past as described above.

FIG. 3 is a flow chart for the time signal coincidence detection in the microcomputer 7. In FIG. 3, it is determined in step 11 whether or not the input signal includes a voice component having the same frequency as the predicted sound (hereinafter referred to as a predicted sound component). If there is no forecast sound component, step 11 is repeated, and if there is, the process proceeds to step 12. In step 12, measurement of the length of the forecast sound component is started. The measurement is started by turning on the timer unit of the microcomputer 7. In step 13, it is determined again whether or not there is a forecast sound component. In this case, it is actually determined whether or not the forecast sound component has ended. If the forecast sound component is still detected, this step is repeated; otherwise, the process proceeds to step 14. In step 14, the length measurement of the forecast sound component is ended by turning off the timer unit. It is determined in step 15 whether or not the length of the measured forecast sound component is the same as the length of the forecast sound signal of the hourly signal. If the lengths are not the same, it is output in step 20 that they do not match the time signal. On the other hand, if the lengths are the same, it is determined in step 16 whether or not the predicted sound component is the third predicted sound.

In the case of the third forecast sound, step 17
Proceed to. In step 17, it is determined whether or not the current deviation of the internal clock unit from the hour is within the average of the past deviations plus one second. If not, step 2
It is output if it does not match the time signal at 0. On the other hand, if it is settled, the input signal is determined to be a time signal and output (step 18). Thereafter, the average value of the deviation of the built-in clock unit at the time of detecting the time signal is updated using the information of the current deviation (step 19).

When the forecast sound component is not the third forecast sound in step 16, the measurement of the length between the forecast sound signals is started in step 21 by turning on the timer unit. In step 22, it is determined whether or not there is a forecast sound component. If not, step 22 is repeated. On the other hand, in some cases, in step 23, the length measurement between the signals is terminated by turning off the timer unit. Thereafter, in step 24, it is determined whether or not the length between the signals is the same as the length between the forecast audio components of the time signal.
If they are the same, the process returns to step 12. On the other hand, if they are different, an output is made at step 20 that the time signal does not match.

By realizing such an operation, when a predictive sound component is present in the input signal, it is compared with the average value of the deviation of the built-in clock unit when the time signal is detected, and the time when the predictive sound component is generated is determined by the internal clock. If the difference is very different from the average
It can be determined that the input signal is not a time signal. Therefore, erroneous detection of the time signal can be reduced, and erroneous operation of time calibration can be reduced. In the above-described flowchart, in step 17, the deviation of the built-in clock is set to the average value + 1 second. However, it goes without saying that this setting differs depending on the month difference of the built-in clock and the time signal detection interval. Also, instead of using the average value of the deviation, for example, using the maximum value or the minimum value of the deviation,
The same effect can be obtained by using the standard deviation in the deviation distribution.

In step 17 in FIG. 3, it is determined whether or not the inputted forecast sound component is a time signal by referring to the fixed value (average value) of the deviation of the built-in clock portion.
With such a criterion, for example, when the clock is calibrated by erroneously detecting the previous time signal, there is a possibility that an accurate time signal cannot be received from the next time. Therefore, if the operation time of the time signal coincidence detection unit is changed in accordance with the information on the deviation from the hour of the built-in clock when the previous time signal was detected, the malfunction of the time calibration can be reduced. .

That is, by setting the operation time of the time coincidence detection unit to a time corresponding to both a case where the previous time signal detection was correctly operated and a case where the previous time signal was erroneously operated, the time signal was erroneously detected at the first time. However, correct detection can be performed from the next time. Further, in the case of erroneous detection, the time signal detection operation time for the next time must be extended, but this operation time is extended only to the next detection after the erroneous detection.

FIG. 4 is a flowchart showing the operation of the time signal coincidence detecting section. Here, if the previous deviation of the built-in clock unit is minus, that is, if the built-in clock unit is behind the time signal,
Of the four values obtained by combining the two values of ± 5 seconds at the previous time and ± 5 seconds at the present time in the built-in clock section, the operation time is the time between the closest time and the farthest time. . This operation time is defined as a time signal detection allowable time. For example, if the built-in clock is 30 seconds late, the built-in clock
If the time is 59:30:30 (hereinafter referred to as 9:59:30), the timepiece at 11:00 advances the built-in clock by 30 seconds to 11: 00: 0 ± 5 seconds. On the other hand, when a signal other than the 10:00 time signal is erroneously detected, the built-in clock section is set to 9: 5.
If 9:30, the time signal at 11 o'clock is 10: 59: 30 ±
5 seconds.

Also, the previous deviation of the built-in clock section is a plus,
That is, when the internal clock section is advanced compared to the time signal, the two values of (current time + previous deviation) ± 5 seconds at the current internal clock section and ± 5 seconds at the current time at the current internal clock section are used. Of the four values obtained by combining the two values, a portion between the closest time and the farthest time is defined as the time signal detection allowable time. For example, if the built-in clock is advanced by 30 seconds, the built-in clock is 10:00:30 at the time signal of 10:00, and the built-in clock is configured at 11:00 at the time signal of 11: 00: 5 ± 5 seconds. Become. If a signal that is not a time signal is erroneously detected at 10:00:30 of the built-in clock section, the built-in clock section is set to 10: 59: 3 in the 11:00 time signal.
0 ± 5 seconds.

In FIG. 4, it is determined in step 31 whether or not a forecast sound component is present in the input signal. If there is no forecast sound component, step 31 is repeated. In step 32, the measurement of the length of the forecast sound component is started by turning on the timer unit. In step 33, it is determined again whether or not there is a forecast sound component. In this case, it is actually determined whether or not the forecast sound component has ended. If there is still a forecast sound component, this step is repeated. In step 34, the measurement of the length of the forecast sound component is ended by turning off the timer unit. At step 35, it is determined whether or not the length of the measured forecast sound component is the same as that of the hourly forecast sound signal. If the lengths are not the same, an output is made at step 40 if the length does not match the time signal. On the other hand, if the lengths are the same, it is determined in step 36 whether or not the predicted sound component is the third predicted sound.

In the case of the third forecast sound, step 37
Proceed to. In step 37, it is determined whether or not the current time of the built-in clock section is within the time signal detection allowable time. If it does not fit, it is output in step 40 that it does not match the time signal. On the other hand, if it does, the input signal is determined to be a time signal and output (step 38). Thereafter, the time signal detection allowable time at the time of the next time signal detection is calculated using the information of the current deviation (step 3).
9), the process ends.

If the predicted sound component is not the third predicted sound in step 36, the measurement of the length between the predicted sound signals is started in step 41 by turning on the timer unit. In step 42, it is determined whether there is a forecast sound component. If not, step 42 is repeated. On the other hand, in some cases, in step 43, the length measurement between the signals is terminated by turning off the timer unit. Thereafter, in step 44, it is determined whether or not the length between signals is the same as the length between hourly forecasts. If they are the same, the process returns to step 32. On the other hand, if they are different, it is output in step 40 that they do not match the time signal, and the process ends.

By realizing such an operation, if the input signal has a forecast sound component, if the time indicated by the built-in clock unit is within the time signal detection allowable time when the time signal is detected,
The forecast sound component is determined to be a time signal. Therefore, even if the previous time signal is erroneously detected, the next time signal can be correctly detected.

In the above-described flowchart, the allowable time signal detection time of the built-in clock unit is set to ± 5 seconds on the hour at step 37, but this value varies depending on the month difference of the built-in clock unit and the time signal detection interval. Needless to say,

Now, consider again the case where the time calibration operation is performed once a day at a predetermined time. If the accuracy of the built-in clock section in the microcomputer 7 is ± 30 seconds per month, The error per day can be regarded as about ± 1 second as described above. Therefore, even if there is a considerable margin, it is impossible that the time signal detection differs from the hour by, for example, ± 15 seconds in the normal operation. Thus, if the elapsed time from the previous detection is, for example, less than 50 hours, the operation of the time signal coincidence detection unit is sufficient if the internal clock unit is at ± 15 seconds. As described above, the time signal detection allowable time of the time signal coincidence detection unit that changes according to the elapsed time from the previous time detection can be set to an appropriate time according to the time signal detection interval and the month difference of the built-in clock unit. .

For example, considering a clock that performs a time signal detection operation at ± 5 seconds on the hour, if the time signal detection was correctly performed last time, the time signal will be present at ± 5 seconds on the hour. . In addition, if the time signal is incorrectly detected last time and the time is calibrated, there will be no time signal at ± 5 seconds on the hour. Furthermore, if the previous time signal detection is not performed,
The next time, the time signal is detected at ± 120 seconds on the hour, and if the previous time signal is detected, the next time the time signal detection operation is performed only at ± 5 seconds on the hour, the clock is incorrectly calibrated last time. If so, the possibility of detecting the time signal next time is extremely low. Here, the time signal detection is performed by the following processing.

FIG. 5 is a flowchart for detecting the coincidence of the time signal in the microcomputer 7 using the time signal detection allowable time set as described above. In this case, the time signal detection interval is 24 hours, and if the elapsed time from the previous time signal detection to the present is less than 50 hours, the time signal detection allowable time is set to ± 15 seconds of the hour at the internal clock section, If it is 50 hours or more, it is set to ± 120 seconds.

Referring to FIG. 5, in step 51, it is determined whether or not there is a forecast sound component in the input signal. If there is no forecast sound component, step 51 is repeated. In step 52, the measurement of the length of the forecast sound component is started by turning on the timer unit. In step 53, it is determined again whether or not there is a forecast sound component. In this case, it is actually determined whether or not the forecast sound component has ended. If there is still a forecast sound component, this step is repeated. In step 54, the measurement of the length of the forecast sound component is ended by turning off the timer unit. It is determined in step 55 whether or not the length of the measured forecast sound component is the same as the length of the forecast sound signal of the hourly signal. If the lengths are not the same, it is output in step 61 that they do not match the time signal. On the other hand, if the lengths are the same, it is determined in step 56 whether or not the forecast sound component is the third forecast sound.

In the case of the third forecast sound, step 57
Proceed to. In step 57, 5 hours after the previous time signal is detected
It is determined whether 0 hours or more have elapsed, and if not, the process proceeds to step 58. In step 58, it is detected whether or not the current time when the time is detected is within ± 15 seconds of the hour in the internal clock section to be calibrated. If within ± 15 seconds of the hour, the detected forecast sound component is output as a time signal (step 59). On the other hand, if it is not within ± 15 seconds of the hour, the detected forecast sound component is output as not a time signal (step 61).

If it is determined in step 57 that 50 hours or more have elapsed since the previous time signal was detected, the process proceeds to step 60. In step 60, the current time when the time signal is detected is set to ±
It is determined whether it is within 120 seconds. Hour ± 120
If within seconds, the detected forecast sound component is output as coincident with the time signal (step 59). On the other hand, if it is not within ± 120 seconds of the hour, the detected forecast sound component is output as not coincident with the time signal (step 61).

When the predicted sound component is not the third predicted sound in step 56, the measurement of the length between the predicted sound signals is started in step 62 by turning on the timer unit. In step 63, it is determined whether there is a forecast sound component. If not, step 63 is repeated. On the other hand, in some cases, in step 64, the length measurement between the signals is terminated by turning off the timer unit. Thereafter, in step 65, it is determined whether or not the length between signals is the same as the length between hourly forecasts. If they are the same, the process returns to step 52. On the other hand, if they are different, it is output in step 61 that they do not match the time signal, and the process ends.

By realizing such an operation, even if a forecast sound component is present in the input signal, if 50 hours or more have passed since the last time signal was detected, the time ± 120 seconds has passed. Otherwise, if no forecast sound component is detected within ± 15 seconds of the hour, it can be determined that the signal is not a time signal. Therefore, erroneous detection of the time signal can be reduced, and malfunction of time calibration can be reduced.

In the description of FIG. 5, the time signal detection interval is set to 24 hours, and when the elapsed time from the previous time signal detection to the present is less than 50 hours, the time signal detection allowable time is set to ± 1 of the hour.
Although the time signal detection permissible time has been described as ± 120 seconds on the hour when the time is 5 seconds or more than 50 hours, a similar effect can be obtained when these values are replaced with other values. Further, in the above description, two time signal detection allowable times are provided, but it goes without saying that the same effect can be obtained even if the time signal detection allowable time is divided into more cases.

[0037]

According to the present invention, it is possible to hold the average value of the deviation at the time when the time signal was detected in the past, and determine that a signal received at a time far from the deviation is not a time signal. Also,
The operation time of the time signal coincidence detection can be changed based on the information on the deviation of the internal clock from the hour when the time signal was detected last time. Further, the operation time can be changed according to the elapsed time from the detection of the previous time signal to the current time.
For this reason, it is possible to accurately detect the time signal and reduce the malfunction of the time calibration.

[Brief description of the drawings]

FIG. 1 is a system block diagram of a timepiece device to which the present invention is applied.

FIG. 2 is a diagram illustrating a relationship between a time signal and an output of a tone decoder.

FIG. 3 is a flowchart for time signal coincidence detection.

FIG. 4 is a flowchart for time signal coincidence detection.

FIG. 5 is a flowchart for time signal coincidence detection.

[Explanation of symbols]

4 Tone decoder 6 Time signal coincidence detection unit, time calibration unit, built-in clock unit and timer unit 7 Microcomputer

Claims (1)

(57) [Claims] [1 claim: a receiving means for receiving a broadcast signal, when included in the broadcast signal received by the upper Ki受 Shin means
A specific frequency detecting means for detecting a signal component of a specific frequency corresponding to the broadcast signal, means for extracting a time signal from a component of the specific frequency detected by the specific frequency detector, time signal from a component of the specific frequency Once the signal is extracted,
Between the time of the internal clock and the time obtained from the time signal
A means for obtaining information on temporal deviation, and a method for obtaining information on the time of the internal clock up to the previous time and the time signal.
Means for holding the average value of the time deviation from the time of the internal clock, and the time obtained from the time of the internal clock and the time signal.
The time difference from the time and the time of the built-in clock up to the last time
Time difference between the time and the time obtained from the time signal
Determines whether the difference from the average value is within a specified tolerance
And the time of the built-in clock and the time signal
The time difference from the time and the time of the built-in clock up to the last time
Time difference between the time and the time obtained from the time signal
If the error from the average value is within the specified tolerance,
Calibration of the built-in clock based on the time obtained from the signal
From the time of the built-in clock and the time signal
Time difference from the time when the
Total time and the time obtained from the time signal
If the deviation from the average of the deviation is not within the predetermined tolerance,
And means for controlling so as not to perform calibration of the internal clock
A clock device with time calibration provided .