JP3523159B2 - Radio-controlled clock and its second signal detection method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio-controlled timepiece that receives a radio signal including a time signal (time standard radio signal) and sets the time based on the time signal. The present invention relates to a radio-controlled timepiece that detects a second signal having a 1-second cycle from a reception result including noise and a second signal detection method thereof in order to improve reception sensitivity.

[0002]

2. Description of the Related Art Generally, a radio-controlled timepiece is used indoors. Therefore, the radio signal becomes weak due to being blocked by a building or the like, and the radio-controlled timepiece must receive such a weak radio signal and set the time.

On the other hand, the radio signal contains various information such as time, day of the week, date, and noise, and the second signal indicating the second of the time detects the timing at which a 40 KHz signal is generated in the radio signal. It is something that can be obtained. Therefore, if noise is mixed in the radio signal, this noise may be detected as the occurrence of a 40 KHz signal. In particular, since the second signal is a signal with a cycle of 1 second, it may overlap with the driving of the step motor provided in the radio-controlled timepiece, and noise generated by the step motor may make it difficult to accurately detect the second signal. there were.

Therefore, conventionally, in order to accurately detect the second hand signal and increase the reception sensitivity, the step motor is stopped during the detection of the radio wave signal to prevent the generation of noise, and the radio wave reception state is as good as possible. The place was selected and the clock was installed.

[0005]

However, even if the step motor is stopped to prevent the generation of noise as in the above-mentioned prior art, the noise intruding from the outside cannot be prevented, and it is not a fundamental countermeasure against noise. Therefore, the receiving sensitivity could not be improved.

Further, even if a place where the reception condition of the radio signal is good is selected, it may be affected by noise intruding from the outside, and it takes time to select the place of installation, and the degree of freedom of the place of installation is low. There was also the problem of not having it.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is a radio-controlled timepiece capable of more accurately detecting the second signal which is most susceptible to noise to be resistant to noise and enhancing the reception sensitivity. And a second signal detection method thereof.

[0008]

A radio-controlled timepiece according to the present invention is a radio-controlled timepiece that receives a radio signal including a time signal and sets the time based on the time signal, in the radio signal every one second. And a receiving circuit that outputs a detection signal that changes in level in a direction determined according to the presence or absence of a frequency signal that occurs for a set time, and the detection signal has a constant period based on a frequency higher than the second signal. And a sampling means for sampling by the sampling means and a sampling value sampled by the sampling means are divided into sampling frames every one second and arranged for a certain period of time.
Sumps that have the same order within each sampling frame
An average value calculation means arranged to seek an average value by summing the ring value from the average value string of each sampling value of one sampling frame of said mean value calculating means is calculated, indicating the level change of the detection signal A specific pattern detecting means for detecting the specific pattern and a second correcting means for synchronizing the seconds based on the time when the specific pattern detecting means detects the specific pattern are provided. Further, in this radio-controlled timepiece, when the specific pattern detecting means detects two or more specific patterns, the average value calculating means is caused to operate by the sampling means instead of the sampling value for the first one sampling frame in the constant second. Re-detection means for adding a new sampled value for one sampling frame and calculating the average value again is provided.

According to the second signal detecting method of the radio-controlled timepiece of the invention, the radio-controlled timepiece receives the radio signal including the time signal and sets the time based on the time signal. A detection signal that is generated every time and that changes in level in a direction determined according to the presence or absence of a frequency signal that is generated for each set time is sampled at a constant cycle based on a frequency higher than the second signal, and the sampled value is sampled. Is divided into sampling frames every 1 second and arranged for a certain number of seconds , and within each sampling frame
The sampled values that have the same order of
It arranged seeking, from the average value column of the calculated respective sampling values 1 sampling frame, and detects a specific pattern indicating the level change of the detection signal, the second synchronization based on the time of detecting the specific pattern To take.
Further, in this second signal detection method, when two or more of the specific patterns are detected, a new sampling value for one sampling frame is added instead of the sampling value for the first one sampling frame in a certain period, and the average value is calculated again. To do.

In the method for detecting the second signal of the radio-controlled timepiece according to the present invention, the signal is generated every one second in the radio signal and is set respectively.
The level change of the detection signal that changes in level in the direction determined according to the presence or absence of the frequency signal generated for a fixed time is detected, and the seconds are synchronized based on the detected level change. In particular, in detecting the level change, in the present invention, the detection signal is sampled for a certain period of time, an average value of the sampled values is obtained, and the level change is detected from the average value. Since detection is performed based on the average value in this way, it is possible to accurately detect even a slight level change due to noise.

If the level change is detected twice or more per second, it is highly likely that noise is mixed in the second signal. In this case, some sampling values are replaced and the average value is again calculated. And the level change is detected again from the average value.

By detecting the level change of the detection signal as described above, it is possible to reliably detect the second signal having a cycle of one second without being disturbed by noise.

On the other hand, in the radio-controlled timepiece based on the above-mentioned second signal detecting method, the direction determined by the presence or absence of the frequency signal generated by the receiving circuit every second in the radio signal and generated for the set time. A detection signal whose level changes to is output. Then, the detection signal is sampled at a constant cycle by the sampling means. This sampling value is divided into sampling frames every 1 second by the average value calculating means and arranged for a certain number of seconds. Furthermore, the order in each sampling frame is the same in the average value calculation means.
An average value is obtained by adding the sampled values, and the average value is arranged in the same manner as the sampled value. The average value sequence of each sampling value for one sampling frame calculated by the average value calculating means always includes a specific pattern indicating the level change (1 second cycle) of the detection signal,
The specific pattern detecting means detects this specific pattern.

Usually, one specific pattern is included in one sampling frame, and the second signal can be synchronized by detecting this specific pattern. If this particular pattern is present more than once in one sampling frame,
It is recognized that this is due to the influence of noise, and the re-detection unit replaces some of the sampling values and performs detection again.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a radio-controlled timepiece according to an embodiment of the present invention, and FIG. 2 is a functional explanatory diagram of the main part thereof.
FIG. 3 is a time chart showing the states of the radio signal and its detection signal.

A receiving circuit 2 receives a radio wave signal including a time signal via the receiving antenna 4, performs predetermined signal processing, and outputs a time signal composed of a pulse signal.

The radio wave signal is, as shown in FIG.
"1" when a 40 KHz signal is transmitted for 0.5 seconds per second
Is set to indicate "0" when transmitted for 0.8 seconds and to indicate "P" (marker indicating information break) when transmitted for 0.2 seconds, and these are combined. 1
The information regarding the time when one minute is one frame in bits / second is configured.

The receiving circuit 2 receives the radio wave signal and receives the radio signal.
A pulse signal (FIG. 3B) is output as a detection signal depending on the presence or absence of a 0 KHz signal. This pulse signal is shown in FIG.
As shown in (b), when a 40 KHz signal is generated in the radio signal, it is set to fall to the L level. Therefore, from that fall to the next fall (40 KHz signal generation to next 40 KHz signal generation) ) Is 1 second, and this becomes the second signal.

On the other hand, when the reception condition of the radio wave signal is poor, the receiving circuit 2 cannot accurately process the 40 KHz signal of the radio wave signal.
The level changes regardless of the presence or absence of a signal (Fig. 3 (c)).
As a result, the second signal cannot be obtained accurately.

In FIG. 1, reference numeral 6 denotes a control unit composed of a microcomputer for inputting a time signal composed of a pulse signal from the receiving circuit 2 to correct the time and detect a second signal.

Reference numeral 8 is a display device, which has a pointer for displaying the time in an analog manner, a drive mechanism thereof, and the like.

The main part of the control unit 6 described above has a functional configuration as shown in FIG. The sampling means 10 samples the detection signal from the receiving circuit 2 based on the 32 Hz signal which is a frequency signal higher than the second signal. That is, when the detection signal shown in FIG. 3B is sampled at 32 Hz, 32 sampling values (level signal of 0 or 1) are obtained in 1 second corresponding to the level of the detection signal, and this is performed for a fixed time.

The average value calculating means 12 divides the sampling value obtained by sampling into sampling frames in which 32 sampling values obtained in one second are set as one segment, as shown in FIG. That is, the sampling values (1) to (32) are regarded as one sampling frame,
The sampling values (33) to (64) are similarly set as one sampling frame. Then, similarly, 32 sampling values are similarly divided into one sampling frame. Then, when the sampling value for a certain period of time is obtained, the average value calculating means 12 adds the sampling values in each sampling frame in a corresponding order to obtain an average value, and removes the influence of a slight level change due to noise. . Then, the obtained 32 average values “1” to “32” are arranged in the same order as the sampling values.

The specific pattern detecting means 14 searches the array of average values "1" to "32" for a specific pattern of level "1110000". This specific pattern shows the trailing edge of the detection signal shown in FIG. 3B, and by detecting this specific pattern, a second signal having a one-second cycle can be obtained.

The second correcting means 16 synchronizes the second digit measured with the time when the specific pattern detecting means 14 detects the specific pattern as a reference, and adjusts the second digit to the second signal of the radio wave signal.

When the specific pattern detecting means 14 detects two or more specific patterns, the re-detecting means 18 causes detection again. That is, since the specific pattern indicating the fall of the detection signal shown in FIG. 3B is generated only once per second, if there are two or more patterns, the level change due to noise as shown in FIG. Has occurred. Therefore, in this case, the sampling values (1) to (32)
In place of the first sampling frame including S, a sampling frame including new sampling values (225) to (256) is inserted, the average value is calculated again, and it is detected whether the average value sequence has a specific pattern. By performing such detection again, the influence of noise on the second signal can be removed.

[0027]

According to the present invention, a signal containing noise obtained by receiving a radio wave signal is sampled at a constant cycle, an average value of the sampled values is obtained, and a second signal within the average value is obtained. Since the second signal is detected by detecting the specific pattern corresponding to, it is possible to remove the influence of noise and reliably detect the second signal.

Further, when two or more specific patterns are detected, a new sampling value is inserted and detection is performed again, so that seconds are not synchronized with an inaccurate detection result.
Seconds can only be synchronized if they are always received correctly.

[Brief description of drawings]

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

FIG. 2 is a functional explanatory diagram of a control unit shown in FIG.

3A is a time chart showing a waveform of a radio wave signal and a generation timing of a 40 KHz signal, FIG. 3B is a time chart of an output signal of a receiving circuit when a receiving state is good, and FIG.
It is a time chart which shows an example of the output signal of a receiving circuit when there is much noise.

FIG. 4 is an explanatory diagram illustrating how to set a sampling frame and how to calculate an average value thereof.

[Explanation of symbols]

2 Receiver circuit 6 control unit 8 display devices 10 Sampling means 12 Mean value calculation means 14 Specific pattern detection means 16 seconds correction means 18 Re-detection means

Claims (2)

(57) [Claims] 1. A radio-controlled timepiece that receives a radio signal including a time signal and sets the time based on the time signal, wherein a frequency is generated every one second in the radio signal and a time is set for each time. A receiving circuit that outputs a detection signal whose level changes in a direction determined according to the presence or absence of a signal, sampling means that samples the detection signal at a constant cycle based on a frequency higher than the second signal, and the sampling means performs sampling. The sampled values are divided into sampling frames every 1 second and arranged for a certain number of seconds , and the order within each sampling frame is the same.
Array that calculates the average value by adding the same sampling values
An average calculation section that, from the average value string of each sampling value of one sampling frame <br/> that said average value calculation means has calculated a specific pattern to detect a specific pattern indicating the level change of the detection signal detected Means, second correction means for synchronizing the seconds based on the time when the specific pattern detection means detects the specific pattern, and the average value calculation means when the specific pattern detection means detects two or more specific patterns. Re-detecting means for adding a new sampling value for one sampling frame sampled by the sampling means instead of the sampling value for the first one sampling frame in the certain second and re-calculating the average value. A characteristic radio-controlled watch. 2. A radio-controlled timepiece that receives a radio signal including a time signal and sets the time based on the time signal, wherein a frequency is generated in the radio signal every one second and at a set time. A detection signal whose level changes in a direction determined according to the presence or absence of a signal is sampled at a constant cycle based on a frequency higher than the second signal, and the sampled value is divided into sampling frames every 1 second for a certain second. Sumps that are arrayed and in the same order within each sampling frame
By summing the ring values arranged by an average value from the average value string of the calculated respective sampling values 1 sampling frame, and detects a specific pattern indicating the level change of the detection signal, detects the specific pattern The second pattern is detected on the basis of the time point, and if two or more of the specific patterns are detected, a new sampling value for one sampling frame is added instead of the sampling value for the first sampling frame in a certain second, and the average value is calculated again. A method for detecting a second signal of a radio-controlled timepiece, characterized by calculating.