CN101344758B - Radio-controlled timepiece and control method for a radio-controlled timepiece - Google Patents

Abstract

The present invention provides a radio-controlled timepiece capable of reducing the influence of the reception environment when acquiring time information and realizing power saving, and a control method thereof. The radio wave corrected clock has: a receiving unit, which receives standard radio waves; a binarization circuit (37), which binarizes the received signal of the standard radio wave according to a prescribed threshold, and outputs a binarized signal; a time counter (43); a TC generating part (44), generate the reference time code according to the time counted by the time counter (43); the duty ratio judging part (45), judge whether the received pulse duty ratio calculated according to the binarized signal is consistent with the duty ratio of the reference time code Consistent; control section (47), when judging that the duty ratio of the received pulse duty ratio and the reference time code is inconsistent, outputs a control signal for changing the threshold value relative to the relative level of the received signal; and TCO decoding section (41) , when it is judged to be consistent, the binarized signal is decoded and the time code is demodulated.

Description

Radio wave corrected clock and its control method

technical field

The present invention relates to a radio wave corrected timepiece and its control method which receives a standard radio wave with time information and corrects the time according to the received standard radio wave.

Background technique

Conventionally, radio-controlled timepieces capable of receiving standard radio waves are known (for example, refer to Patent Documents 1 and 2).

The standard radio wave is amplitude modulated, and the radio-controlled timepiece has a binarization circuit in the receiving circuit. The binarization circuit uses a filter or the like to extract the envelope of the received signal, and then compares the envelope signal with a comparator or the like. and reference voltage and perform binarization. Then, the radio-controlled timepiece acquires time information based on the time code signal obtained by the binarization circuit, and displays the time.

In addition, these radio-controlled timepieces also have an AGC circuit (Automatic Gain Control: Automatic Gain Control) that automatically controls the amplification rate of the received signal according to the received signal.

[Patent Document 1] Japanese Patent Application Laid-Open No. 10-274681

[Patent Document 2] Japanese Patent Laid-Open No. 2006-60849

However, although the radio-controlled timepiece has an AGC circuit, the binarization level (threshold) of the binarization circuit is fixed, and it may not be possible to obtain a correct time code depending on the reception environment.

Therefore, in radio-controlled timepieces, the following processing is also performed: receiving a standard radio wave for about 3 to 7 minutes, acquiring a plurality of time codes, evaluating each time code, and judging whether correct time information has been obtained.

However, in this method, it takes at least several minutes until it can be judged whether or not the correct time information has been obtained. Therefore, for example, it takes time until it is judged that the reception environment has deteriorated and correct time information cannot be obtained, and there is a problem that power consumption increases accordingly.

Contents of the invention

An object of the present invention is to provide a radio-controlled timepiece capable of reducing the influence of the receiving environment when acquiring time information and realizing power saving, and a control method thereof.

The radio-controlled timepiece of the present invention receives a standard radio wave with a time code, and implements time correction according to the received standard radio wave, and is characterized in that the radio-corrected clock has: a receiving unit for receiving the standard radio wave; a binarization unit, It binarizes the received signal of the standard radio wave according to a prescribed threshold, and outputs a binarized signal; a time counter, which counts the time; a time code generation unit, which, according to the time counted by the time counter, Generate a reference time code; a duty ratio judging unit, which calculates the pulse duty ratio of the binarized signal output from the binarization unit, and judges whether the calculated received pulse duty ratio is consistent with that obtained by the time The duty cycle of the reference time code generated by the code generation unit is consistent; the level switching unit is configured to determine that the received pulse duty cycle is the same as the duty cycle of the reference time code by the duty cycle judging unit. When the ratios do not match, change the relative level of the threshold with respect to the received signal; and a time code decoding unit, which determines that the received pulse duty ratio and the When the duty ratio of the reference time code is the same, the binarized signal is decoded and the time code is demodulated.

According to the present invention, the time code generation unit generates the reference time code based on the time counted by the time counter. In addition, the duty ratio judging unit has a duty ratio of the generated reference time code and a reception pulse duty ratio of a binarized signal obtained by binarizing a reception signal of a standard radio wave received by the reception unit. Compare. Furthermore, when the duty ratio of the received pulse does not coincide with the duty ratio of the reference time code, the level switching means performs, for example, control to change the amplification factor of the received signal, or performs binarization processing on the received signal. The control of the threshold changes the relative level of the threshold with respect to the received signal. Thus, the duty cycle of the received pulse coincides with the duty cycle of the reference time code, and the binarization conditions in the binarization unit are optimized.

The feature of the present invention is that the accuracy of a quartz watch usually has a daily difference of less than 1 second. In a radio wave corrected watch, it is almost unnecessary to correct the time when the radio wave reception process is performed regularly every day. Therefore, based on the time based on the internal time counter Based on the new discovery that the time code and the received time code of the received standard radio wave usually match, the received radio wave was evaluated based on the duty ratio of the time code.

That is, in Japan's standard radio wave JJY, the time code alternates "0 signal", "1 signal" and "P signal" in parallel to indicate the time and year, month, and day. Therefore, the duty cycle of the time code is based on the published value determined by time. Therefore, by generating a reference time code in advance based on the time counted by the time counter, as long as the radio-controlled timepiece is set to receive JJY, the pulse duty ratio of the received signal should match the duty ratio of the reference time code. Therefore, if the duty ratio of the received pulse does not coincide with the duty ratio of the above-mentioned time code, it can be grasped that the level of the received signal is lowered due to the influence of the reception environment around the radio-controlled timepiece, etc., and the threshold value relative to the received signal can be changed. Optimized relative to level to get correct timecode.

Moreover, the change of the relative level of such a threshold can be controlled by acquiring, for example, a time code of 1 minute. Compared with the conventional control method that cannot be judged without several minutes of reception, it can be performed in a short time. to process. Therefore, it is possible to shorten the overall reception time and realize power saving.

Furthermore, by changing the relative level of the threshold, even if the reception environment is slightly deteriorated, the threshold level suitable for the received signal can be adjusted, and an accurate time code can be obtained. Therefore, according to the radio-controlled timepiece of the present invention, the influence of the receiving environment can be reduced, and the correct time can be corrected.

In addition, the duty ratio of the time code refers to the ratio of the high (High) level portion within the predetermined signal range of the time code with respect to the time code. For example, in the time code, when the duty ratio is obtained using 1-minute data, the ratio obtained by dividing the time at which the high level becomes high in 1-minute data by 1 minute (= 60 seconds) is the duty ratio. empty ratio.

In addition, the relative level of the threshold value to the received signal refers to, for example, the relative level of the threshold voltage to the amplitude value (voltage value) of the received signal. That is, the received signal oscillates between a high level and a low (Low) level, and the threshold is arranged between these levels. At this time, for example, the value of the threshold with respect to the maximum level value of the received signal may be set as a relative level.

Furthermore, the coincidence mentioned in the present invention includes a small error range. For example, when the duty cycle of the reference time code and the duty cycle of the received pulse differ by about 1 to 3%, it is also judged as the duty cycle of the reference time code. It is consistent with the received pulse duty cycle. That is, in the pulse signal of the standard radio wave every 1 second, according to the difference in the length of the high level (difference in the duty cycle), information such as "1", "0" and "mark" are formed, and the combination of these information Send timecode. For example, in JJY, "P mark" is 20%, "1" is 50%, and "0" is 80% in the duty ratio of a pulse signal of 1 Hz. Therefore, the duty ratio of one time code (time code of one minute) fluctuates depending on the time information of each time code, but as long as the current time and the date and time in the time counter do not deviate greatly, the error range is About 1 to 3%. Therefore, in the case of receiving JJY, as long as the duty ratio of the received pulse substantially matches the duty ratio of the reference time code, it can be determined that the threshold level has been optimized and the correct time code can be acquired.

In addition, the received pulse duty ratio and the duty ratio of the reference time code may be calculated based on the one-minute time code, or may be calculated based on a part of the one-minute time code. In this case, for example, if the duty cycle of the hour (hour) data part of each time code is calculated and compared, the internal time (time counter value) of the radio-controlled watch hardly deviates by more than 1 hour from the time of the standard radio wave. Therefore, it can also be judged by using whether or not the respective duty ratios are completely consistent.

In addition, in the radio-controlled timepiece according to the present invention, it is preferable that the duty ratio judging unit judges that the duty ratio of the received pulse is determined to be equal to the duty ratio of the reference time code when it is judged that the duty ratio of the received pulse does not match the duty ratio of the reference time code. Whether the duty cycle is larger than the duty cycle of the reference time code or smaller than the duty cycle of the reference time code, in the case where the duty cycle of the received pulse is larger than the duty cycle of the reference time code, the electrical The level switching unit increases the relative level of the threshold with respect to the received signal, and when the duty cycle of the received pulse is smaller than the duty cycle of the reference time code, the level switching unit decreases the The threshold is relative to the relative level of the received signal.

When the duty ratio of the received pulse is larger than the duty ratio of the reference time code, the threshold level is lower than the level of the received signal, so it is predicted that a signal that should be judged to be low is judged to be high. Conversely, when the duty ratio of the received pulse is smaller than the duty ratio of the reference time code, the threshold level is higher than the level of the received signal, so it is predicted that a signal that should be judged to be high is judged to be low. flat.

Therefore, if the relative level of the threshold with respect to the received signal is increased in the case where the received pulse duty ratio is larger than the duty ratio of the reference time code, the received pulse duty ratio When the duty ratio of the reference time code is small, the relative level of the threshold can be appropriately adjusted in a shorter time by reducing the relative level of the threshold with respect to the received signal.

Furthermore, in the radio-controlled timepiece of the present invention, it is preferable that the radio-controlled timepiece has a threshold value adjusting unit that changes the threshold value in the binarization unit, and that when the duty ratio judging unit judges that it is When the received pulse duty ratio does not match the duty ratio of the reference time code, the level switching unit outputs a control signal for changing the threshold in the binarization unit to the threshold adjustment unit The threshold adjustment unit changes the level of the threshold according to the control signal, and changes the relative level of the threshold relative to the received signal.

According to the present invention, since the level switching means changes the threshold level in the binarization means, even if the signal amplification factor is fixed, the level of the threshold value relative to the received signal can be changed, and an accurate time code can be obtained.

For example, when the duty ratio of the signal pulse is larger than the duty ratio of the reference time code, the threshold level is lower than the received signal, so it is determined that the noise component of the low-level portion of the received signal is equal to or greater than the threshold, and the The portion of the signal judged to be low level is judged to be high level. In this case, by raising the threshold, the noise component in the low-level portion becomes smaller than the threshold level, and a correct time code can be obtained.

On the other hand, when the signal pulse duty ratio is smaller than the duty ratio of the reference time code, the threshold level is higher than the received signal, so it is determined that the high level part is smaller than the threshold level, and it should be judged as high The signal part of the level is judged as low level. In this case, by lowering the threshold, the high-level portion becomes equal to or higher than the threshold level, and a correct time code can be obtained.

In addition, when the binarization means is constituted by a comparator, in order to change the threshold level, for example, it is only necessary to switch the level of the reference voltage value input to the comparator. Therefore, the threshold level can be changed by simple control, and the circuit configuration can be set relatively easily.

Also, the threshold level may be configured to be continuously changeable, but generally, it may be configured to be switchable in multiple stages (for example, 3 to 4 stages).

Furthermore, in the radio-controlled timepiece of the present invention, it is preferable that the radio-controlled timepiece includes: an amplifying unit that amplifies a received signal of a standard radio wave received; and an amplification adjusting unit that changes the received signal in the amplifying unit. magnification ratio, when it is judged by the duty ratio judging unit that the received pulse duty ratio is inconsistent with the duty ratio of the reference time code, the level switching unit outputs to the amplification adjustment unit A control signal for changing the signal amplification rate of the amplifying unit, the amplification adjustment unit changes the signal amplification rate of the amplifying unit according to the control signal, and changes the relative level of the threshold value relative to the received signal.

According to the present invention, since the level switching means changes the signal amplification factor, even if the threshold level is fixed, the relative level of the threshold with respect to the received signal can be changed, and an accurate time code can be obtained.

For example, when the duty ratio of the signal pulse is greater than the duty ratio of the reference time code, the noise component of the low-level part is amplified to be equal to or higher than the threshold level, and the signal part that should be judged to be low-level is judged to be high. level. In this case, by reducing the signal amplification factor, the noise component in the low-level portion becomes smaller than the threshold level, and a correct time code can be obtained.

On the other hand, when the duty ratio of the signal pulse is smaller than the duty ratio of the reference time code, the high-level part decreases to less than the threshold level, and the signal part that should be judged to be high-level is judged to be low-power. flat. In this case, by increasing the signal amplification factor, the high-level portion becomes equal to or higher than the threshold level, and a correct time code can be obtained.

Furthermore, the level switching unit changes the signal amplification rate in the amplification unit, so, for example, when an AGC circuit is provided as the amplification adjustment unit, it is only necessary to switch the AGC characteristic of the AGC circuit to control the amplification rate in the amplification unit. Such an AGC circuit is originally incorporated in a radio-controlled timepiece, so when changing the relative level of the threshold value by changing the signal amplification factor, it can be realized at low cost without assembling new parts.

Furthermore, in the radio-controlled timepiece of the present invention, it is preferable that the radio-controlled timepiece includes: a receiving circuit unit including the receiving unit, the binarization unit, and the threshold adjustment unit; and a control circuit unit including the The time counter, the time code generating unit, the duty ratio judging unit, the time code decoding unit, and the level switching unit, the control circuit unit outputs the output signal from the electric circuit to the receiving circuit unit. The control signal output by the level switching unit controls the receiving state of the standard radio wave in the receiving circuit part, and the receiving circuit part has a control signal decoding unit, and the control signal decoding unit controls the receiving state of the standard radio wave from the control circuit. Decoding the control signal output by the level switching unit of the unit, and outputting the decoded control signal to the threshold adjustment unit.

According to the present invention, the decoding unit decodes the input control signal, and the threshold adjustment unit adjusts the threshold of the binarization unit based on the decoded control signal. Thus, since the decoding unit decodes the control signal, the control signal output from the control circuit unit can be set as a simple signal, and the reliability of the communicated signal can be improved.

In addition, the radio-controlled timepiece of the present invention preferably includes: a receiving circuit unit having the receiving unit, the amplifying unit, the amplifying adjusting unit, and the binarization unit; and a control unit. a circuit unit having the time counter, the time code generating unit, the duty ratio judging unit, the time code decoding unit, and the level switching unit, the control circuit unit providing the receiving circuit unit with Outputting the control signal output from the level switching means to control the receiving state of the standard radio wave in the receiving circuit part, the receiving circuit part has a control signal decoding means for The control signal output from the level switching unit of the control circuit unit is decoded, and the decoded control signal is output to the amplification adjustment unit.

According to the present invention, the decoding unit decodes the input control signal, and the amplification adjusting unit adjusts the signal amplification ratio of the amplifying unit according to the decoded control signal. Thus, since the decoding unit decodes the control signal, the control signal output from the control circuit unit can be set as a simple signal, and the reliability of the communicated signal can be improved.

Furthermore, in the radio-controlled timepiece of the present invention, it is preferable that the radio-controlled timepiece has a serial communication line that connects the receiving circuit unit and the control circuit unit, and that the control circuit unit communicates in serial. output the control signal to the receiving circuit part via the serial communication line, and the receiving circuit part receives the control signal via the serial communication line in a serial communication mode, and utilizes the control The signal decoding unit performs decoding.

According to the present invention, the receiving circuit unit and the control circuit unit are connected by a serial communication line. Thereby, compared with the case where the receiving circuit unit and the control circuit unit are connected by parallel communication lines, the number of connected communication lines can be reduced, and the circuit configuration of the radio-controlled timepiece can be further simplified. In addition, parallel communication needs to synchronize the data transmission in each signal line, so it is difficult to increase the communication speed. However, in the present invention, by serially outputting the control signal, the communication speed can be increased and the transmission of signals can be suppressed. Errors, for example, can improve responsiveness in voltage adjustment by the voltage adjustment unit and signal amplification ratio adjustment by the amplification adjustment unit, and improve reliability.

In addition, in the radio-controlled timepiece according to the present invention, it is preferable that, after the reception operation is started, after the duty judging means judges that the duty ratio of the reception pulse coincides with the duty ratio of the reference time code The level switching unit keeps the relative level of the threshold value relative to the received signal unchanged until the receiving operation ends.

According to the present invention, after setting the relative level of the threshold value with respect to the received signal to an appropriate level, the level is fixed. Therefore, during the period when the time code is decoded by the time code decoding unit, all The level is maintained at a constant value.

As a result, stable binarization processing can be performed, bit changes can be prevented, and time codes can be decoded more accurately.

Furthermore, in the radio-controlled timepiece of the present invention, it is preferable that the level switching unit stores the relative level of the threshold value set at the time of receiving operation with respect to the received signal according to the type of the standard radio wave, and stores the relative level of the threshold value set at the time of the receiving operation for the next reception. When operating, the stored relative level of the threshold value to the received signal is set as an initial setting value.

A radio-controlled timepiece generally has a function of automatically receiving it at a preset time. During such regular reception, there is a high possibility that the surrounding reception environment is also substantially constant. Therefore, if the relative level of the threshold value set at the time of previous reception with respect to the received signal is used as an initial value, there is a high possibility that the duty ratio of the received pulse coincides with the duty ratio of the reference time code. , without switching the level. Therefore, reception processing can be efficiently performed in a shorter time.

Furthermore, in the radio-controlled timepiece of the present invention, it is preferable that the receiving unit is configured to be able to selectively receive a plurality of types of standard radio waves, and that the radio-controlled timepiece has a reception radio-wave setting unit that selects the type of the standard radio wave received by the receiving unit, the time code generating unit generates a reference time code corresponding to the type of the standard radio wave selected by the received radio wave setting unit, and the duty judging unit compares with The determination is made by the duty ratio of the reference time code corresponding to the type of the standard radio wave selected by the received radio wave setting unit and the received pulse duty ratio of the binarized signal.

According to the present invention, for example, in a radio-controlled timepiece that can receive various standard radio waves such as JJY (Japan), WWVB (USA), DCF77 (Germany), etc. Since the duty ratio of the reference time code is set, an optimum level can be set for each standard radio wave, and an accurate time code can be obtained.

Furthermore, in the radio-controlled timepiece of the present invention, it is preferable that the radio-controlled timepiece has an internal time reliability judging unit for judging the reliability of the time counted by the time counter. The time code generating unit generates the reference time code when the internal time reliability judging unit judges that the time counted by the time counter is reliable.

The internal time reliability judging unit judges whether the time counted by the time counter, that is, the internal time and the actual time coincide to some extent to judge its reliability. Here, the internal time reliability judging means judges that the reliability of the internal time is low in the following cases, for example, as a criterion for judging the reliability of the internal time. That is, (1) after performing the process of resetting the value of the time counter, the reception of the standard radio wave has not been successful even once; (2) when a predetermined time (for example, 1 (3) when the user has manually adjusted the time, etc., the internal time reliability judging unit judges that the reliability of the internal time is low.

When the internal time deviates greatly, the duty ratio of the reference time code generated based on the internal time is a value different from the duty ratio of the time code at the actual time. Therefore, when the relative level of the threshold value to the received signal is changed by the level switching unit to a level corresponding to the duty ratio of the reference time code, it may not be possible to obtain an accurate time code based on the received standard radio wave. . On the other hand, in the present invention, when the reliability of the internal time is determined to be low by the internal time reliability determination unit, the time code generation unit does not generate the reference time code. Thereby, an erroneous reference time code based on internal time deviation is not generated, and setting of the threshold level of a received signal based on the reference time code can be performed only when the reliability of the internal time is high. Therefore, a more reliable time code can be obtained, and more accurate time adjustment can be performed.

The method for controlling a radio wave corrected timepiece of the present invention is used for a radio wave corrected timepiece that receives a standard radio wave having a time code and performs time correction based on the received standard radio wave, and is characterized in that the standard radio wave is received, and the time is adjusted according to a predetermined threshold value. Binarize the received signal of the standard radio wave, and output the binarized signal, generate a reference time code according to the time counted by the time counter, calculate the pulse duty ratio of the binarized signal, and judge whether the received pulse duty ratio is It is consistent with the duty ratio of the generated reference time code, and when it is determined that the duty ratio of the received pulse is inconsistent with the duty ratio of the reference time code, changing the threshold value relative to the received signal The level change process is repeated until the duty cycle of the received pulse coincides with the duty cycle of the reference time code. In the case that the duty ratios of the signals are consistent, the binarized signal is decoded and the time code is demodulated.

According to the present invention, similar to the above-mentioned radio-controlled timepiece, the overall reception time can be shortened to save power, and even if the reception environment is slightly deteriorated, the threshold level can be adjusted to be suitable for the reception signal, and the correct time can be obtained. code, it is possible to reduce the influence of the reception environment and to correct the correct time.

Description of drawings

FIG. 1 is a block diagram showing the configuration of a radio-controlled timepiece according to a first embodiment.

FIG. 2 is a circuit diagram showing configurations of a binarization circuit and a VREF switching circuit of the first embodiment.

FIG. 3 is a graph showing the reception pulse duty ratio and amplitude change of each signal with respect to the Japanese standard radio wave "JJY".

FIG. 4 is a graph showing the reception pulse duty ratio and amplitude change of each signal with respect to the standard radio wave "WWVB" in the United States.

FIG. 5 is a graph showing the reception pulse duty ratio and amplitude change of each signal with respect to the German standard radio wave "DCF77".

FIG. 6 is a graph showing the reception pulse duty ratio and amplitude change of each signal with respect to the British standard radio wave "MSF".

FIG. 7 is a diagram showing a time code format of the Japanese standard radio wave "JJY".

8 is a diagram illustrating a method of measuring a pulse duty ratio of a TCO signal by a duty ratio determination unit.

9 is a diagram illustrating another example of a method of measuring the pulse duty ratio of the TCO signal by the duty ratio determination unit.

FIG. 10 is a flowchart showing the time adjustment operation of the radio-controlled timepiece.

11 shows the original waveform of TC included in the standard radio wave, the waveform of the envelope signal when the standard radio wave is received in a weak electric field environment, and the envelope signal when the standard radio wave is received in a noisy environment diagram of the waveform.

12 is a diagram showing an original waveform of TC included in a standard radio wave and a waveform of a TCO signal obtained by binarizing a received signal of the standard radio wave according to each reference voltage after envelope detection.

FIG. 13 is a block diagram showing the configuration of a radio-controlled timepiece according to the second embodiment.

FIG. 14 is a graph showing the relationship between the AGC voltage and the gain in the first amplifier circuit.

15 is a graph showing the relationship of the AGC voltage with respect to the input level of the received signal in each AGC characteristic switched by the AGC circuit.

FIG. 16 is a flowchart showing the time adjustment operation of the radio-controlled timepiece.

FIG. 17 shows the original waveform of TC included in the standard radio wave, the waveform after envelope detection of the received signal output according to the setting of each AGC voltage characteristic, and the waveform after the envelope detection. A graph of the waveform of the TCO signal after quantization.

FIG. 18 is a block diagram showing the configuration of a radio-controlled timepiece according to a third embodiment.

19 is a flowchart showing the time adjustment operation of the radio-controlled timepiece according to the third embodiment.

Label description

1, 1A, 1B: radio wave correction clock; 2: antenna as receiving unit; 3, 3A: receiving circuit part; 4, 4A: control circuit part; 6: external operation part as receiving radio wave setting unit; 32, 32A : the first amplification circuit as the amplification unit; 36, 36A: the AGC circuit as the amplification adjustment unit; 37: the binarization circuit as the binarization unit; 38: the VREF switching circuit as the threshold adjustment unit; 39: the control signal Decoding circuit of decoding unit; 41: TCO decoding part as time code decoding unit; 43: time counter; 44: TC generation part as time code generating unit; 44A: as time code generating unit and internal time reliable 45: a duty ratio determination unit 47, 47A: a control unit as a level switching unit.

Detailed ways

[the first embodiment]

Next, a radio-controlled timepiece 1 according to a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a radio-controlled timepiece according to a first embodiment.

FIG. 2 is a circuit diagram showing configurations of a binarization circuit and a VREF switching circuit.

FIG. 3 is a graph showing the reception pulse duty ratio and amplitude change of each signal with respect to the Japanese standard radio wave "JJY".

FIG. 4 is a graph showing the reception pulse duty ratio and amplitude change of each signal with respect to the standard radio wave "WWVB" in the United States.

FIG. 5 is a graph showing the reception pulse duty ratio and amplitude change of each signal with respect to the German standard radio wave "DCF77".

FIG. 6 is a graph showing the reception pulse duty ratio and amplitude change of each signal with respect to the British standard radio wave "MSF".

FIG. 7 is a diagram showing a time code format of the Japanese standard radio wave "JJY".

8 is a diagram illustrating a method of measuring a pulse duty ratio of a TCO signal by a duty ratio determination unit.

9 is a diagram illustrating another example of a method of measuring the pulse duty ratio of the TCO signal by the duty ratio determination unit.

(1) Structure of radio-controlled timepiece 1

As shown in FIG. 1 , a radio-controlled timepiece 1 includes an antenna 2 as a receiving unit, a receiving circuit unit 3 , a control circuit unit 4 , a display unit 5 , an external operation member 6 as a radio-received wave setting unit, and a quartz oscillator 48 .

The antenna 2 receives long-wave standard radio waves (hereinafter referred to as “standard radio waves”), and outputs the received standard radio waves to the receiving circuit unit 3 .

The receiving circuit section 3 demodulates the reception signal of the standard radio wave received by the antenna 2, and outputs it to the control circuit section 4 as TCO (Time Code Out: time code output). In addition, the detailed description of the reception circuit part 3 is mentioned later.

The control circuit unit 4 decodes the input TCO to generate a TC (time code), and sets the time of the time counter 43 based on the generated TC. Furthermore, the control circuit unit 4 controls the display unit 5 to display the time of the time counter 43 . Furthermore, the control circuit unit 4 judges the duty ratio of the TCO input from the receiving circuit unit 3 , and outputs a control signal to the receiving circuit unit 3 . In addition, the detailed description of the control circuit part 4 is mentioned later.

The display unit 5 is driven and controlled by the drive circuit unit 46 of the control circuit unit 4 , and displays the time counted by the time counter 43 . The display unit 5 may, for example, have a liquid crystal panel for displaying the time, or may have a dial and hands for displaying the time by moving the hands through the control circuit unit 4 .

The external operation member 6 is composed of, for example, a crown, a setting button, and the like, and outputs a predetermined operation signal to the control circuit section 4 by the user's operation. Examples of the operation signal include: radio wave type setting data and reception standard for setting the type of standard radio waves received by the antenna 2 (for example, "JJY" in Japan, "WWVB" in the United States, "DCF77" in Germany, etc.). Correction request information, etc. to adjust the time by radio waves.

The crystal resonator 48 for the reference clock outputs a predetermined reference signal (reference clock, for example, a signal of 1 Hz), and the reference signal output from the crystal resonator 48 is input to the control circuit unit 4 .

(2) Configuration of the receiving circuit section 3

As shown in FIG. 1, the receiving circuit unit 3 is configured to include: a synchronous circuit 31, a first amplifying circuit 32 as an amplifying unit, a band-pass filter (Band-pass filter, hereinafter sometimes abbreviated as "BPF") 33, a second Amplifying circuit 34, envelope detection circuit 35, AGC (Auto Gain Control) circuit 36 as amplification adjustment unit, binarization circuit 37 as binarization unit, VREF switching circuit 38 as threshold value adjustment unit, and control The decoding circuit 39 of the signal decoding unit.

The synchronous circuit 31 is configured with a capacitor, and the synchronous circuit 31 and the antenna 2 form a parallel resonance circuit. The synchronization circuit 31 receives radio waves of a specific frequency by the antenna 2 . The standard radio wave received by the antenna 2 is converted into a voltage signal by the synchronization circuit 31 and output to the first amplifier circuit 32 . In addition, in the receiving circuit unit 3 of this embodiment, in addition to the Japanese standard radio wave "JJY", it is also possible to receive the American standard radio wave "WWVB", the German standard radio wave "DCF77", the British standard radio wave "MSF", etc. Standard radio waves for each region.

The first amplifier circuit 32 adjusts the gain based on the signal input from the AGC circuit 36 described later, amplifies the reception signal input from the synchronization circuit 31, and inputs it to the BPF 33 with a constant amplitude. That is, the first amplifying circuit 32 lowers the gain when the amplitude is large and increases the gain when the amplitude is small, based on the signal input from the AGC circuit 36, and amplifies the received signal to a constant amplitude.

The BPF 33 is a filter for extracting a signal of a desired frequency band. That is, by passing through the BPF 33, components other than the carrier component are removed from the received signal input from the first amplifying circuit 32.

The second amplifying circuit 34 further amplifies the received signal input from the BPF 33 with a fixed gain.

The envelope detection circuit 35 is configured to have an unshown rectifier and an unshown low-pass filter (Low-pass Filter, LPF), rectifies and filters the received signal input from the second amplifying circuit 34, and filters The obtained envelope signal is output to the AGC circuit 36 and the binarization circuit 37 .

The AGC circuit 36 outputs a signal for determining a gain when the first amplifier circuit 32 amplifies the received signal based on the received signal input from the envelope detection circuit 35 .

As shown in FIG. 2 , the binarization circuit 37 is composed of a binarization comparator, one of two input terminals is connected to the envelope detection circuit 35 , and the other input terminal is connected to the VREF switching circuit 38 . Furthermore, the binarization circuit 37 outputs a TCO signal which is a binarized signal based on the envelope signal input from the envelope detection circuit 35 and a reference voltage (threshold) having a predetermined voltage input from the VREF switching circuit 38 .

Specifically, when the voltage of the envelope signal is higher than the reference voltage, the binarization circuit 37 outputs a signal having a voltage of H level (high level) to the TCO decoding unit 41 of the control circuit unit 4, As the TCO signal, and when the voltage of the envelope signal is lower than the reference voltage, the binarization circuit 37 outputs an L voltage whose voltage value is lower than an H level signal to the TCO decoding part 41 of the control circuit part 4. A flat (low level) signal is used as a TCO signal. Alternatively, when the voltage of the envelope signal is higher than the reference voltage, an L-level signal is output to the TCO decoding section 41 of the control circuit section 4 as the TCO signal, which is equal to or equal to the envelope signal. When the voltage is lower than the reference voltage, an H-level signal is output to the TCO decoding unit 41 of the control circuit unit 4 as a TCO signal.

The VREF switching circuit 38 generates reference voltages VREF1 to VREF4 based on the power supply voltage VDD output from the constant voltage source 381 , and outputs the reference voltages to the binarization circuit 37 . The VREF switching circuit 38 is configured to include: a constant voltage source 381; four resistors R1 to R4 arranged between the constant voltage source 381 and the ground GND; Four switches SW1 to SW4 between the middle of the line GND and the binarization circuit 37; and a constant current source 382 arranged between the resistor R4 and the ground line GND.

Wherein, each switch SW1～SW4 is constituted by analog switch, and switch SW1 is disposed between resistance R1, R2 and binarization circuit 37, and switch SW2 is disposed between resistance R2, R3 and binarization circuit 37, and switch SW3 It is arranged between the resistors R3 and R4 and the binarization circuit 37 , and the switch SW4 is arranged between the resistor R4 , the constant current source 382 and the binarization circuit 37 . The switches SW1 to SW4 are independently connected to the decoding circuit 39 via selection lines SEL1 to SEL4 , and are switched on/off in accordance with a signal input from the decoding circuit 39 . Then, by turning any one of these switches SW1 to SW4 on (conducting state) and turning the other switches off (non-conducting state), the power supply voltage VDD output from the constant voltage source 381 passes through the The current IS output from the constant current source 382 varies with the resistance R, and becomes the reference voltage VREF, which is input to the binarization circuit 37 .

Such a VREF switching circuit 38 outputs the highest voltage reference voltage VREF1 to the binarization circuit 37 when only the switch SW1 is in the ON state. Furthermore, when only the switch SW2 is turned on, the VREF switching circuit 38 outputs the reference voltage VREF2 with the second highest voltage, and when only the switch SW3 is turned on, the VREF switching circuit 38 outputs the reference voltage VREF with the third highest voltage. The reference voltage VREF3, and when only the switch SW4 is on, the VREF switching circuit 38 outputs the lowest reference voltage VREF4.

The decoding circuit 39 is connected to the control circuit unit 4 described later via the serial communication line SL. Furthermore, the decoding circuit 39 decodes the control signal input from the control circuit unit 4, and outputs the ON/OFF state for setting the switches SW1 to SW4 to the respective selection lines SEL1 to SEL4 based on the code included in the control signal. Signal of the disconnected state.

(3) Configuration of the control circuit section 4

As described above, the control circuit unit 4 controls the operation of the receiving circuit unit 3 , specifically, outputs a control signal for switching the reference voltage VREF to the decoding circuit 39 of the receiving circuit unit 3 . And the control circuit part 4 decodes the TCO signal input from the binarization circuit 37, and sets the time of the time counter 43 based on the time code generated by decoding. Furthermore, the control circuit unit 4 controls the display unit 5 to display the time of the time counter 43 .

As shown in FIG. 1, the control circuit unit 4 is configured to have: a TCO decoding unit 41 as a time code decoding unit, a storage unit 42, a time counter 43, a TC generating unit 44 as a time code generating unit, and a duty A duty ratio judging unit 45 of a ratio judging unit, a drive circuit unit 46, and a control unit 47 as a level switching unit. In addition, the reference signal output from the above-mentioned quartz oscillator 48 is input to the control unit 47 .

The TCO decoding unit 41 decodes the TCO signal input from the binarization circuit 37 of the receiving circuit unit 3, and extracts a time code (TC) including date information, time information, etc. included in the TCO signal. Then, the TCO decoding unit 41 outputs the extracted TC to the control unit 47 .

Specifically, the TCO decoding unit 41 recognizes the waveform of the TCO signal, and measures the reception pulse duty ratio with respect to a predetermined pulse width (for example, 1 Hz). Then, the TC is identified from the TCO signal according to the difference in duty cycle of the received pulse. For example, in the standard radio wave (JJY) used in Japan, as shown in FIG. %), a signal of "1" (1 signal) is recognized. Then, when the pulse width of the high-level signal is 0.8 seconds with respect to the pulse width of 1 second (that is, when the duty ratio is 80%), a signal of "0" (0 signal) is recognized. When the pulse width of the high-level signal is 0.2 seconds with respect to the pulse width of 1 second (that is, when the duty ratio is 20%), a "P" signal (P signal) is identified. Then, the TCO decoding unit 41 recognizes a predetermined TC based on the arrangement of these recognized 1 signals, 0 signals, and P signals.

In addition, in the above description, identification of TCs in JJY was exemplified. However, when the received standard radio waves are of other types, TCs are identified based on duty ratios corresponding to the respective radio waves. For example, as shown in Figure 4, Figure 5, and Figure 6, in the standard radio wave (WWVB) in the United States, a 1 signal is recognized when the duty ratio is 50%, and a 0 signal is recognized when the duty ratio is 20%. signal, a P signal is identified with a duty cycle of 80%. Also, in the German standard radio wave (DCF77), a 1 signal is recognized when the duty ratio is 80%, and a 0 signal is recognized when the duty ratio is 90%. In the British standard radio wave (MSF), A 1 signal is recognized when the duty ratio is 80%, a 0 signal is recognized when the duty ratio is 90%, and a P signal is recognized when the duty ratio is 50%.

The storage unit 42 is a memory for storing various data and programs necessary for the control circuit unit 4 to control the receiving circuit unit 3 and the like. Such a storage unit 42 is set when the radio-controlled timepiece 1 is manufactured, and stores a radio wave data table in which radio wave data related to standard radio waves received by the receiving circuit unit 3 is recorded.

This radio wave data table is constructed in a table structure in which radio wave data formed by associating radio wave type data and reference radio wave data is recorded as one record, and a plurality of these radio wave data are recorded.

Here, the radio wave type data is information on the type of the standard radio wave received by the receiving circuit unit 3, for example, JJY, WWVB, DCF77, MSF, etc. are recorded.

The reference radio wave data records the duty ratio of TC (time code) included in the standard radio wave specified by the radio wave type data. Specifically, the reference radio wave data records the duty ratios of the 0 signal, the 1 signal, and the P signal constituting the TC, and information on the amplitude change of the standard radio wave.

In addition, the storage unit 42 stores radio wave type setting data related to the standard radio wave type received by the receiving circuit unit 3 and reception setting data recording other setting information related to reception.

The time counter 43 counts time (internal time) based on the reference signal output from the quartz oscillator 48 . Specifically, the time counter 43 has a second counter that counts seconds, a minute counter that counts minutes, and an hour counter that counts hours.

The second counter is, for example, a counter that circulates the signal at 60 counts, that is, for 60 seconds, when a reference signal of 1 Hz is output from the quartz oscillator 48 . The minute counter is a counter that counts 60 times of the reference signal of 1 Hz and then counts 1, and counts at 60, that is, a 60-minute cycle. The hour counter is a counter that counts 1 Hz after counting 3600 times of the reference signal, and counts by 24, that is, a 24-hour cycle.

In addition, the minute counter may be configured such that every time the second counter counts 60, a signal is output from the second counter to the minute counter to increment the minute counter. Similarly, the hour counter may be configured such that every time the minute counter counts 60, a signal is output from the minute counter to the hour counter to increase the hour counter count.

The TC generation unit 44 generates a reference time code (reference TC) based on the time counted by the time counter.

Specifically, the TC generation unit 44 reads the radio wave type setting data of the reception setting data stored in the storage unit 42 and generates a reference time code corresponding to the standard radio wave type recorded in the radio wave type setting data. For example, when setting the Japanese standard radio wave "JJY" is recorded in the radio wave type setting data, the TC generation unit 44 generates the reference TC in accordance with the time code format of JJY.

Here, as shown in FIG. 7 , in the time code format of JJY, one signal is transmitted every one second, and one record is constituted by 60 seconds. That is, one frame is 60-bit data. In addition, as data items, current time information of minutes and hours; and calendar information of total days, years (last 2 digits of the Western calendar), and days of the week from January 1 of the current year are included. The value of each item is composed of a combination of numerical values allocated for each second, and ON and OFF of the combination are judged according to the type of signal.

Furthermore, the TC generation unit 44 generates the reference TC of the current time information from the header to the minute and hour, that is, the reference TC corresponding to 0 to 20 seconds, in combination with the above-mentioned JJY time code format.

Then, the TC generation unit 44 outputs the generated reference TC to the duty ratio determination unit 45 .

The duty ratio judging section 45 compares the reception pulse duty ratio of the TCO signal input from the receiving circuit section 3 with the reference duty ratio of the reference TC generated by the TC generation section 44, and judges whether the reception pulse duty ratio of the TCO signal is Same as the reference duty cycle of the reference TC. Specifically, the duty ratio determination unit 45 measures the reception pulse duty ratio with respect to the input TCO signal and the reference TC by the method shown in FIG. 8 .

That is, in the measurement method shown in FIG. 8 , the input TCO signal and the reference TC are sampled for a predetermined period using a sampling clock of, for example, 64 Hz or 100 Hz generated based on the reference clock, and the quality of the sampled TCO signal is judged. Whether the signal level is high or low. At this time, when the sampled TCO and the reference TC are at a high level, the TCO decoding unit 41 judges as "1", and when they are at a low level, judges as "0". Here, for example, in the case of sampling at 100 Hz for 30 seconds, the total number of data is 30×100=3000, and when “1”s are 751, the reception pulse duty ratio is 751/3000=25.0%.

In addition, not limited to the measuring method shown in FIG. 8 described above, the pulse duty ratio can also be measured by the measuring method shown in FIG. 9 .

That is, in the measurement method shown in FIG. 9 , the rising detection of the rising edge U of the detection TCO signal and the reference TC is implemented, the timer is driven from the position where the rising edge U is detected, and the timer is driven until the falling edge D is detected. Time is measured. The measurement of the time T from the rising edge U to the falling edge D is repeated, and the ratio of the total time T from the rising edge U to the falling edge D to the total sampling time of the TCO signal and the reference TC is calculated. Measure the received pulse duty cycle and the reference duty cycle.

Then, the duty ratio judging unit 45 compares the reception pulse duty ratio of the TCO signal measured and calculated by the above measurement method with the reference duty ratio of the reference TC, and judges whether the reception pulse duty ratio of the TCO signal is the same as that of the reference TC. The base duty cycle is the same. At this time, the duty ratio judging section 45 recognizes the radio wave type setting data of the reception setting data stored in the storage section, and compares the reception pulse duty ratio and Baseline duty cycle for comparison. For example, when the Japanese standard radio wave (JJY) is recorded in the radio wave type setting data, the reception pulse of the part from the head indicating the reception start part of the TCO signal to the 20 seconds when the time information of the hour and minute is digitized is recognized. Duty cycle, compare the received pulse duty cycle with the reference duty cycle.

In addition, the "coincidence" mentioned here includes an error of about 1 to 3% due to the time deviation of the time counter and the influence of the receiving environment. That is, when the difference between the reception pulse duty ratio and the reference duty ratio is about 1 to 3%, the duty ratio judging unit 45 judges that it is "coincidence".

Moreover, when the duty ratio judging unit 45 judges that the reception pulse duty ratio of the TCO signal does not match the reference duty ratio, it further judges whether the reception pulse duty ratio of the TCO signal is larger than the reference duty ratio or is higher than the reference duty ratio. Small.

The drive circuit unit 46 controls the display state of the display unit 5 based on the time display control signal output from the control unit 47 , and performs control to display the time on the display unit 5 . For example, when the display unit 5 has a liquid crystal panel and displays the time on the liquid crystal panel, the drive circuit unit 46 controls the liquid crystal panel based on the time display control signal to perform control to display the time on the liquid crystal panel. Furthermore, when the display unit 5 has a dial and hands, the drive circuit unit 46 outputs a pulse signal to a stepping motor that drives the hands, and performs control to move the hands by the driving force of the stepping motor.

The control unit 47 is driven in accordance with the drive frequency input from the quartz oscillator 48 and performs various control processes. That is, the control unit 47 performs control to correct the count of the time counter 43 by outputting the TC input from the TCO decoding unit 41 to the time counter 43 . Then, the control unit 47 outputs a time display control signal for causing the display unit 5 to display the time counted by the time counter 43 to the drive circuit unit 46 .

Furthermore, the control unit 47 outputs a predetermined control signal to the receiving circuit unit 3 based on the determination of the duty ratio determination unit 45 .

Specifically, when the operation signal input from the external operation member 6 includes the radio wave type setting data for setting the standard radio wave type, the control unit 47 updates the radio wave reception status of the storage unit 42 based on the radio wave type setting data. Status setting information. For example, when the operation signal of the radio wave type setting data that sets the type of the standard radio wave to be received as JJY is inputted through the operation of the external operation member 6, the control unit 47 sets the reception setting data in the storage unit 42 Record the radio wave type setting data of the receiving JJY.

And, for example, when an operation signal for performing time correction based on a standard radio wave is input through the external operation member 6, or when a preset correction scheduled time is reached, the control unit 47 controls the TC generating unit 44 to generate a reference TC, and further, Control is performed so that the duty ratio judging unit 45 compares and judges the reference duty ratio of the reference TC generated by the TC generation unit 44 with the reception pulse duty ratio of the TCO signal.

Furthermore, when it is determined in the duty ratio judging section 45 that the reception pulse duty ratio of the TCO signal is larger than the reference duty ratio of the reference TC, the control section 47 outputs the reference voltage in the VREF switching circuit 38 to the receiving circuit section 3. Improve control signal by level 1. And, when it is judged by the duty ratio judging unit 45 that the reception pulse duty ratio of the TCO signal is smaller than the reference duty ratio of the reference TC, the control unit 47 outputs the reference voltage in the VREF switching circuit 38 to the receiving circuit unit 3. Lowered control signal by level 1.

In addition, as described above, the control unit 47 and the decoding circuit 39 are connected through the serial communication line SL, and control signals are input to the decoding circuit 39 through the serial communication line SL. Accordingly, a control signal for controlling voltage switching of the VREF switching circuit 38 can be output to the VREF switching circuit 38 via the decoding circuit 39 .

Here, in the serial communication between the control unit 47 and the receiving circuit unit 3, a two-wire synchronous interface capable of bidirectional communication between the control unit 47 and the receiving circuit unit 3 may be used, and bidirectional serial communication may be performed based on this interface. communication. In this case, after the control signal is output from the control unit 47 to the receiving circuit unit 3, the receiving circuit unit 3 transfers the received and recognized control signal to the control unit 47 again, and the control unit 47 confirms the output control signal and the input signal. The data difference between the control signals enables more reliable serial communication.

(4) Operation of radio-controlled timepiece 1

Next, the time adjustment operation based on the standard radio wave in the radio-controlled timepiece 1 described above will be described.

FIG. 10 is a flowchart showing the time adjustment operation of the radio-controlled timepiece 1 .

11 shows the original waveform of TC included in the standard radio wave, the waveform of the envelope signal when the standard radio wave is received in a weak electric field environment, and the envelope signal when the standard radio wave is received in a noisy environment diagram of the waveform.

12 is a diagram showing an original waveform of TC included in a standard radio wave and a waveform of a TCO signal obtained by binarizing a received signal of the standard radio wave according to each reference voltage after envelope detection.

When the radio-controlled timepiece 1 is manufactured, a radio-controlled data table is written and stored in the storage unit 42 . In addition, when the radio-controlled timepiece 1 is manufactured, JJY is recorded as default data, for example, as the radio wave type setting data of the reception setting data. Therefore, when the receiving circuit is manufactured, the radio-controlled timepiece 1 is set in a state where the TC included in the JJY can be decoded.

In FIG. 10 , the control unit 47 of the radio-controlled timepiece 1 recognizes that an operation signal for time correction is input from the external operation member 6 or when the preset time is reached, and receives a standard radio wave by the antenna 2 to start the time correction operation. control (step S101).

In this step S101 , the standard radio wave received by the antenna 2 is converted into a voltage signal (received signal) by the synchronization circuit 31 . Then, the received signal is amplified to a predetermined level by the first amplifying circuit 32, the bandpass filter 33, the second amplifying circuit 34, and the envelope detection circuit 35, and a signal of a desired frequency band is extracted, rectified and filtered to form an envelope network signal. Furthermore, the envelope signal is binarized by the binarization circuit 37 into a TCO signal, and the TCO signal is output to the control circuit unit 4 .

After this step S101 , the control unit 47 of the control circuit unit 4 recognizes the radio wave type setting data from the reception setting data stored in the storage unit 42 . Here, in the initial state, since JJY is recorded as the radio wave type setting data as described above, the control unit 47 recognizes that the received standard radio wave is JJY. Also, when the reception setting data is changed by the operation of the external operation member 6, the type of the standard radio wave recorded in the changed reception setting data is identified (step S102). Then, the control unit 47 outputs the recognized reception setting data to the TC generation unit 44 .

Then, the TC generation unit 44 of the control circuit unit 4 generates a reference TC based on the time counter 43 (step S103 ). At this time, the reception setting data input from the control unit 47 is recognized, and the reference TC is generated by digitizing the time information on the time and division corresponding to the standard radio wave type. For example, when the Japanese standard radio wave "JJY" is set in the reception setting data, the reference TC of the current time information from the head to the minute and hour is generated in combination with the time code format of JJY, that is, the reference TC from 0 to 20 seconds corresponds to the baseline TC. Then, the TC generation unit 44 outputs the generated reference TC to the duty ratio determination unit 45 .

Then, after step S103, when the reference TC is input from the TC generation unit 44, the duty ratio determination unit 45 of the control circuit unit 4 calculates the reference duty ratio of the reference TC according to the measurement method shown in FIG. 8 or FIG. ratio (step S104).

Then, when the TCO signal is input from the receiving circuit unit 3 (step S105), the duty ratio determination unit 45 calculates the reception pulse duty ratio of the TCO signal according to the measurement method shown in FIG. 8 or FIG. 9 described above. Then, the duty judging unit 45 judges whether or not the received pulse duty coincides with the reference duty calculated in step S104 (step S106 ).

Here, in the receiving circuit unit 3 , as shown in FIG. 11 , the envelope signal after the envelope detection has a different waveform depending on the reception environment of the standard radio wave. For example, as shown in Fig. 11(a), in the case of a weak electric field where there is little ambient noise in the receiving environment but the distance from the transmitting station is long, the standard radio wave is weak, so the amplitude of the envelope signal is small and the signal level is also low. get smaller. Furthermore, when the receiving environment is a noisy environment, the received signal of the standard radio wave is affected by the noise, and both the amplitude and the signal level become large. Therefore, when the envelope signal is binarized by the binarization circuit 37, a binarized signal (TCO signal) having a different waveform due to a difference in the reference voltage is output.

In step S106 , the duty ratio judging unit 45 calculates the reception pulse duty ratio of such a TCO signal, and judges whether or not the reception pulse duty ratio matches the reference duty ratio.

For example, as shown in FIG. 12, the standard radio wave (JJY) including the TCO signal shown in A1 is received, envelope detection is performed by the receiving circuit unit 3, and a signal with a waveform shown in A2 in FIG. 12 is obtained.

Here, when the VREF switching circuit 38 switches to a high reference voltage setting (for example, VREF1), the TCO signal having the waveform shown in A3 is output from the receiving circuit unit 3 to the control circuit unit 4 . In this case, the duty ratio determination unit 45 compares the reference duty ratio (68%) of the reference TC calculated in step S104 with the received pulse duty ratio (54%) of the calculated TCO signal, It is determined that the reception pulse duty ratio of the TCO signal is smaller than the reference duty ratio.

Then, when the VREF switching circuit 38 switches to a low reference voltage setting (for example, VREF3), the TCO signal having the waveform shown in A5 is output from the receiving circuit unit 3 to the control circuit unit 4 . In this case, the duty ratio determination unit 45 compares the reference duty ratio (68%) of the reference TC calculated in step S104 with the received pulse duty ratio (75%) of the calculated TCO signal, It is determined that the reception pulse duty ratio of the TCO signal is larger than the reference duty ratio.

Furthermore, when the VREF switching circuit 38 switches to a setting where the reference voltage is intermediate (for example, VREF2 ), the TCO signal having the waveform shown in A4 is output from the receiving circuit unit 3 to the control circuit unit 4 . In this case, the duty ratio judging unit 45 compares the reference duty ratio (68%) of the reference TC calculated in step S104 with the received pulse duty ratio (67%) of the calculated TCO signal, It is determined that the reception pulse duty ratio of the TCO signal matches the reference duty ratio.

Then, when it is determined in the duty ratio judging section 45 that the received pulse duty ratio does not coincide with the reference duty ratio, the control section 47 judges whether the reference voltage can be switched in the VREF switching circuit 38 (step S107), and if it is possible to switch In the case of , a control signal for switching the reference voltage is output to the receiving circuit section 3 .

For example, when the TCO signal shown in A3 of FIG. 12 is obtained, it is judged that the reception pulse duty ratio of the TCO signal is smaller than the reference duty ratio, so the control unit 47 outputs a voltage lowered by 1 to the reference voltage in the VREF switching circuit 38. Level (set as VREF2) control signal to increase the receive pulse duty cycle.

And, when the TCO signal shown in A5 of FIG. 12 is obtained, it is judged that the reception pulse duty ratio of the TCO signal is larger than the reference duty ratio, so the control unit 47 outputs an output that increases the reference voltage in the VREF switching circuit 38 by 1 Level (set as VREF2) control signal to reduce the receive pulse duty cycle.

In this way, by switching the reference voltage, for example, when the reception environment shown in FIG. , however, the TCO can be obtained accurately by lowering the reference voltage to lower the binarization level. Moreover, when the receiving environment shown in FIG. 11(b) is a noisy environment, the received signal of the standard radio wave is affected by noise, and the amplitude and signal level become large. level, so that the TCO can be accurately obtained.

Then, when the above-mentioned control signal is input to the receiving circuit unit 3 , the control signal is decoded by the decoding circuit 39 and output to the VREF switching circuit 38 . VREF switching circuit 38 switches the reference voltage according to the control signal. As a result, the reference voltage in the binarization circuit 37 changes, and the TCO signal whose waveform has been corrected is output to the control circuit unit 4 again.

On the other hand, when it is determined in step S107 that the reference voltage cannot be switched, for example, when the current reference voltage setting is the setting of the lowest voltage, namely VREF4, and it is determined that the reception pulse duty ratio reference of the TCO signal is When the duty ratio is small, the reception of the standard radio wave is terminated, and the time adjustment operation is terminated (step S109).

And, in step S106, for example, as shown in A4 of FIG. Second synchronization processing is performed (step S110). That is, the standard radio wave is a radio wave in which 1 TC is transmitted every minute, and the above-mentioned 0 signal, 1 signal, and P signal are transmitted every 1 second. Therefore, each signal can be identified by performing second synchronization processing by detecting the rise of the signal every second of the standard radio wave or the like.

Thereafter, the control unit 47 controls the TCO decoding unit 41 to decode the TCO signal to acquire the TC (step S111 ). In addition, standard radio waves are sequentially input to the antenna 2, and the standard radio waves are received by the receiving circuit unit 3. However, during the TC decoding process in step S111, the control unit 47 maintains the set voltage of the VREF switching circuit 38. The reference voltage (threshold) in the binarization circuit 37 is not changed.

Then, the control unit 47 judges whether an accurate TC has been acquired in step S111 (step S112), and if an accurate TC has been acquired, ends the receiving operation of the standard radio wave in the receiving circuit unit 3 (step S113). Then, the control unit 47 outputs the acquired TC to the time counter 43, corrects each counter value of the time counter 43, and corrects the display time of the display unit 5 (step S114).

On the other hand, in step S112, when the accurate TC cannot be obtained due to a difference in the received pulse duty ratio, the process of step S109 is performed, that is, the receiving operation is terminated, and the time adjustment operation is terminated.

(5) Effects of the radio-controlled timepiece 1 of the first embodiment

As described above, in the radio-controlled timepiece 1 described above, the duty ratio judging section 45 compares the reference duty ratio of the reference TC, which is determined by the TC generation section 44 according to the time, and the reception pulse duty ratio of the TCO signal. generated at the time counted by the counter 43. Furthermore, when it is judged by the duty judging unit 45 that the reception pulse duty ratio of the TCO signal does not match the reference duty ratio, the control unit 47 outputs a control to switch the reference voltage of the binarization circuit 37 to the receiving circuit unit 3 . Signal.

Therefore, optimization can be performed so that the reception pulse duty ratio of the TCO signal output from the binarization circuit 37 coincides with the reference duty ratio. And, the reference TC is generated by the TC generation part 44 in conjunction with the current time, and the TCO signal having a reception pulse duty ratio consistent with the reference duty ratio of the reference TC is decoded by the TCO decoding part 41, whereby the TCO signal The reliability is improved, accurate TC can be obtained, and the time adjustment process of the radio-controlled timepiece 1 can be accurately performed based on the decoded TC.

In addition, it can be determined whether or not the received pulse duty ratio matches the reference TC only by comparing the portion of the TCO signal in which the time-divided time information is recorded. For example, in the standard radio wave of JJY, it can be judged as long as the time code of 20 seconds is received.

Therefore, it can be judged in a short time compared with the conventional method in which it takes several minutes to receive radio waves, and it is impossible to judge whether or not the correct time code has been received unless a plurality of time codes are acquired. Therefore, the average reception time of the radio-controlled timepiece can be shortened, and power saving can be achieved.

Furthermore, since the reference voltage in the binarization circuit 37 can be changed, even if the receiving environment is slightly deteriorated, the threshold level can be adjusted to be suitable for the received signal, and an accurate time code can be obtained. Therefore, it is possible to reduce the influence of the reception environment such as the noise environment and the strength of received radio waves, and to correct the time to the correct time.

Furthermore, since the reference TC is generated by the TC generation unit 44 in conjunction with the current time, the time adjustment operation of the radio-controlled timepiece 1 can be performed at the timing when the user desires to perform time adjustment.

Furthermore, while the TCO signal is decoded into TC by the TCO decoding unit 41 , the control unit 47 maintains the reference voltage set by the VREF switching circuit 38 and does not change the reference voltage in the binarization circuit 37 .

Therefore, since the reference voltage does not change during decoding, it is possible to avoid problems such as preventing accurate decoding due to bit changes, for example, and to decode an accurate TC.

Furthermore, the receiving circuit unit 3 has a decoding circuit 39 , decodes the control signal input from the control circuit unit 4 by the decoding circuit 39 , and outputs the decoded control signal to the VREF switching circuit 38 .

Therefore, since the decoding circuit 39 decodes the control signal, the control signal output from the control circuit unit 4 can be set as a simple signal, and the reliability of the communicated signal can be improved.

Furthermore, the TC generating unit 44 generates a reference TC in a format corresponding to the type of the standard radio wave recorded in the radio wave type setting data. Then, the duty ratio judging section 45 compares the reference duty ratio of the reference TC generated based on the type of the standard radio wave with the reception pulse duty ratio of the TCO signal, and the control section 47 outputs to the receiving circuit section 3 according to the comparison result: control signal.

Therefore, the radio-controlled timepiece 1 can correspond to the types of the plurality of standard radio waves, and extract the optimum TCO signal from the received signals of the respective standard radio waves. Therefore, for example, even when moving to a place where a different standard radio wave is distributed, the time can be adjusted easily and accurately only by operating the external operation member 6 to set the type of standard radio wave.

Furthermore, the receiving circuit unit 3 and the control circuit unit 4 are connected by a serial communication line. Therefore, the number of communication lines can be reduced and the circuit configuration of the radio-controlled timepiece 1 can be further simplified compared to the case where the receiving circuit unit 3 and the control circuit unit 4 are connected by a parallel communication circuit. Furthermore, the communication speed can be further increased by serially outputting the control signal from the control circuit unit 4 to the receiving circuit unit 3 via the serial communication line. Furthermore, by using a pair of serial communication lines to connect the control circuit section 4 and the receiving circuit section 3 to enable two-way communication, after the control signal is output from the control section 47 to the receiving circuit section 3, the receiving circuit section 3 will receive and The recognized control signal is transferred to the control unit 47 again, and the data difference between the output control signal and the input control signal can be confirmed by the control unit 47 . With this configuration, it is possible to perform serial communication with higher reliability.

[the second embodiment]

Next, a radio-controlled timepiece 1A according to a second embodiment of the present invention will be described with reference to the drawings.

FIG. 13 is a block diagram showing the configuration of a radio-controlled timepiece according to the second embodiment.

FIG. 14 is a graph showing the relationship between the AGC voltage and the gain in the first amplifier circuit.

15 is a graph showing the relationship of the AGC voltage with respect to the input level of the received signal in each AGC characteristic switched by the AGC circuit.

In addition, when describing the radio-controlled timepiece 1A of the second embodiment, the same structures as those of the radio-controlled timepiece 1 of the above-mentioned first embodiment are assigned the same reference numerals, and their descriptions are simplified or omitted.

(1) Structure of radio-controlled timepiece 1A

In FIG. 13 , a radio-controlled timepiece 1A has: an antenna 2, a receiving circuit unit 3A for receiving standard radio waves input from the antenna 2, a control circuit unit 4A for controlling the receiving circuit unit 3A, and a time counter 43 for displaying the time determined by the control circuit unit 4A. The display unit 5 for counting the time, the external operation member 6 for inputting the operation of the radio-controlled timepiece 1A, and the quartz vibrator 48 .

The control unit 47 of the above-mentioned first embodiment outputs a control for changing the reference voltage in the binarization circuit 37 when the duty ratio judging unit 45 judges that the reception pulse duty ratio of the TCO signal is different from the reference duty ratio. However, when the control section 47A of the radio-controlled timepiece 1A judges by the duty ratio judging section 45 that the received pulse duty ratio of the TCO signal is different from the reference duty ratio, the output changes the signal amplified by the first amplifying circuit 32A. rate control signal.

(2) Configuration of the receiving circuit section 3A

As shown in FIG. 13, the receiving circuit unit 3A has: a synchronization circuit 31, a first amplifier circuit 32A as an amplifier unit, a BPF 33, a second amplifier circuit 34, an envelope detection circuit 35, an AGC circuit 36A, and a binarization circuit. 37. VREF switching circuit 38, and decoding circuit 39. The configurations of the synchronization circuit 31, the BPF 33, the second amplifier circuit 34, and the envelope detection circuit 35 are the same as those of the first embodiment, and description thereof will be omitted.

The first amplifier circuit 32A, like the first amplifier circuit 32 in the radio-controlled timepiece 1 of the first embodiment, switches the AGC voltage and adjusts the gain according to the signal input from the AGC circuit 36A, and amplifies the reception signal input from the synchronization circuit 31 , feed it into BPF 33.

Here, the relationship between the AGC voltage and the gain in the first amplifier circuit 32A is as shown in FIG. 14 . That is, when the AGC voltage is set at 0.0 to 0.2V, the gain in the first amplifying circuit 32A is 80dB, and when the AGC voltage is set at 0.2V or higher, the gain decreases approximately in proportion to the AGC voltage. When the AGC voltage is set to 1.0V, the gain is about 0.0dB. In addition, as the AGC voltage input to the first amplifying circuit 32A, a variable width of about 0.1 to 0.9V is set.

The AGC circuit 36A outputs an AGC voltage corresponding to the AGC characteristic set by the control signal input from the decoding circuit 39 to the first amplifier circuit 32A.

Specifically, as shown in FIG. 15 , AGC circuit 36A selects one AGC characteristic from AGC1 to AGC4 based on a control signal, and outputs an AGC voltage corresponding to the selected AGC characteristic to first amplifier circuit 32A.

For example, when the AGC characteristic of AGC1 is selected, the AGC circuit 36A outputs an AGC voltage of 0.4V to the first amplifying circuit 32A when the input level of the received signal input to the first amplifying circuit 32A is about 50 dB. . Then, when the input level of the received signal becomes large, for example, about 66 dB, the AGC circuit 36A inputs an AGC voltage of 0.8 V to the first amplifier circuit 32A. As described above, the AGC circuit 36A is controlled by outputting the AGC voltage corresponding to the input level of the received signal input to the first amplifying circuit 32A so that the amplitude of the received signal is kept constant according to the AGC characteristic.

In addition, in the second embodiment, as shown in FIG. 15 , a configuration in which the AGC voltage can be switched to any one of AGC1, AGC2, AGC3, and AGC4 is exemplified, but it is also possible to select five or more AGC voltages Any one of them is output to the first amplifying circuit 32A. In addition, the AGC voltage output to the first amplifying circuit 32A may be continuously changed. However, since the power supply voltage used in the electronic circuit of the watch is lower than 1.4V, the dynamic range of the AGC voltage is narrow, as described above. , preferably configured to switch the AGC characteristic.

The decoding circuit 39 is connected to the control circuit unit 4A described later via the serial communication line SL, as in the first embodiment described above. And this decoding circuit 39 decodes the control signal input from the control circuit part 4A, and outputs the signal for setting the AGC voltage in the AGC circuit 36A based on the code contained in this control signal.

(3) Configuration of the control circuit unit 4A

The control circuit unit 4A has substantially the same configuration as the control circuit unit 4 of the radio-controlled timepiece 1 of the first embodiment. That is, as shown in FIG. 13 , the control circuit unit 4A is composed of: a TCO decoding unit 41, a storage unit 42, a time counter 43, a TC generation unit 44, a duty ratio determination unit 45, a drive circuit unit 46, and a control circuit unit 41. Part 47A.

The control unit 47A in the control circuit unit 4A of the radio-controlled timepiece 1A of the second embodiment is driven according to the drive frequency input from the quartz oscillator 48, and performs various control processes. That is, the control unit 47A performs control to correct the count of the time counter 43 by outputting the TC input from the TCO decoding unit 41 to the time counter 43 similarly to the control unit 47 of the first embodiment. Then, the control unit 47A outputs a time display control signal for causing the display unit 5 to display the time counted by the time counter 43 to the drive circuit unit 46 .

Then, the control unit 47A outputs a predetermined control signal to the receiving circuit unit 3A based on the determination of the duty ratio determination unit 45 . Specifically, when it is determined by the duty ratio determination unit 45 that the reception pulse duty ratio of the TCO signal is larger than the reference duty ratio, the control unit 47A outputs the AGC characteristic set by the AGC circuit 36A to the reception circuit unit 3A. Switch to a control signal that sets the AGC characteristic to reduce the gain by 1 stage. In addition, when the duty judging unit 45 judges that the received pulse duty ratio of the TCO signal is smaller than the reference duty ratio, the control unit 47A outputs to the receiving circuit unit 3A to switch the AGC characteristic set by the AGC circuit 36A to Set to the control signal of the AGC characteristic that increases the gain by one stage.

(4) Operation of radio-controlled timepiece 1A

Next, the time adjustment operation based on the standard radio wave in the radio-controlled timepiece 1A described above will be described.

FIG. 16 is a flowchart showing the time adjustment operation of the radio-controlled timepiece.

FIG. 17 shows the original waveform of TC included in the standard radio wave, the waveform after envelope detection of the received signal output according to the setting of each AGC voltage characteristic, and the waveform after the envelope detection. A graph of the waveform of the TCO signal after quantization.

In FIG. 16 , the radio-controlled timepiece 1A performs substantially the same time adjustment operation as the radio-controlled timepiece 1 described above. That is, in the radio-controlled timepiece 1A, the same processing as steps S101 to S106 in the time adjustment operation of the radio-controlled timepiece 1 is performed. Here, the description of the operations of steps S101 to S105 is omitted, and the description of the operations of step S106 is briefly described.

In step S106, in the control circuit unit 4A of the radio-controlled timepiece 1A, the duty ratio determination unit 45 compares the reception pulse duty ratio of the TCO signal confirmed in step S105 and the reference duty ratio calculated in step S104. Compare the duty cycle to determine whether the received pulse duty cycle is consistent with the reference duty cycle.

For example, as shown in FIG. 17, when the standard radio wave (JJY) including the TCO signal indicated by A1 is received, and the AGC voltage corresponding to the AGC characteristic of AGC1 is output from the AGC circuit 36A, the envelope after envelope detection The envelope signal has a waveform shown in A6 of FIG. 17 , and the TCO signal obtained when the envelope signal A6 is binarized by the binarization circuit 37 has a waveform shown in A7 of FIG. 17 .

In this case, the duty ratio judging unit 45 compares the reference duty ratio (68%) of the reference TC calculated in step S104 with the pulse duty ratio (54%) of the TCO signal, and judges that the duty ratio of the TCO signal is The reception pulse duty ratio is smaller than the reference duty ratio.

Then, when an AGC voltage corresponding to the AGC characteristic of AGC2 is output from the AGC circuit 36A, an envelope signal of a waveform shown in A8 of FIG. 17 is obtained, and a TCO signal shown in A9 is output. In this case, the duty ratio judging unit 45 compares the reference duty ratio (68%) of the reference TC calculated in step S104 with the received pulse duty ratio (67%) of the calculated TCO signal, It is determined that the reception pulse duty ratio of the TCO signal matches the reference duty ratio.

Then, in this step S106, when the duty ratio judging section 45 judges that the received pulse duty ratio does not match the reference duty ratio, the control section 47A judges whether or not the AGC characteristic can be switched in the AGC circuit 36A (step S201). , when switching is possible, a control signal for switching the AGC characteristic is output to the receiving circuit section 3A.

For example, when the TCO signal shown in A7 of FIG. 17 is obtained, it is determined that the reception pulse duty of the TCO signal is smaller than the reference duty. In this case, the control unit 47A needs to increase the gain of the first amplifying circuit 32A (decrease the AGC voltage) to increase the duty ratio of the received pulse, so it outputs a signal that switches the AGC characteristic in the AGC circuit 36A to increase the gain of the first stage. Set (set to AGC2) control signal.

Also, although not shown in the figure, when it is determined that the received pulse duty ratio of the TCO signal is larger than the reference duty ratio, the control unit 47A needs to reduce the gain of the first amplifier circuit 32A (increase the AGC voltage) to reduce the Small receive pulse duty cycle. In this case, a control signal for switching the AGC characteristic in the AGC circuit 36A to a setting that reduces the gain of the first stage is output.

Then, when the above-mentioned control signal is input to the receiving circuit unit 3A, the control signal is decoded by the decoding circuit 39 and output to the AGC circuit 36A (step S202). The AGC circuit 36A switches the AGC characteristic according to the control signal. Accordingly, the AGC voltage output to the first amplifier circuit 32A changes, and the signal amplification factor also changes. Therefore, when envelope detection is performed on the received signal and output as an envelope signal, the amplitude of the envelope signal changes compared with the original waveform, thereby changing the waveform of the TCO signal.

On the other hand, when it is determined in step S201 that the AGC voltage cannot be switched, for example, when the current AGC characteristic is set to AGC1 in FIG. In the case of , the process of step S109 is performed, that is, the reception of the standard radio wave is terminated, and the time adjustment operation is terminated.

In addition, in step S106, for example, as shown in A9 of FIG. 17 , when the duty ratio judging unit 45 judges that the reception pulse duty ratio matches the reference duty ratio, the radio-controlled timepiece of the first embodiment is executed. Step S110 to step S114 of 1 are the same processing.

That is, in step S110, the control unit 47A performs second synchronization processing based on the currently received TCO signal, and in step S111, uses the TCO decoding unit 41 to decode the TC from the TCO signal. At this time, like the radio-controlled timepiece 1 of the first embodiment, the control unit 47A maintains the setting of the AGC characteristic of the AGC circuit 36A during the TC decoding process in step S111, and does not change the AGC characteristic during the decoding process.

Then, in step S112, the control unit 47A judges whether or not the correct TC has been obtained in step S111, and if the correct TC has been obtained, the processing of step S113 is performed, that is, the reception of the standard radio wave in the receiving circuit unit 3A is terminated. action. Then, in step S114 , the control unit 47A outputs the acquired TC to the time counter 43 , corrects each counter value of the time counter 43 , and performs control to display the corrected time on the display unit 5 .

On the other hand, in step S112, when the accurate TC cannot be obtained due to a difference in the received pulse duty ratio, the process of step S109 is performed, that is, the receiving operation is terminated, and the time adjustment operation is terminated.

(5) Effects of the radio-controlled timepiece 1A of the second embodiment

As described above, in the radio-controlled timepiece 1A of the above-mentioned second embodiment, the duty ratio judging section 45 compares the reference duty ratio of the reference TC which is the duty ratio of the received pulse of the TCO signal. 44 is generated based on the time counted by the time counter 43. Furthermore, when it is judged by the duty ratio judging unit 45 that these reference duty ratios do not coincide with the reception pulse duty ratio of the TCO signal, the control unit 47A outputs to the receiving circuit unit 3A the AGC characteristic switch in the first amplifying circuit 32A. control signal.

Therefore, the signal amplification ratio in the first amplifying circuit 32A is changed, and the TCO signal can be optimized so that the reception pulse duty ratio of the TCO signal output from the binarization circuit 37 becomes the reference duty ratio. Therefore, like the radio-controlled timepiece 1 of the first embodiment, accurate TC can be obtained from the TCO signal, and the time adjustment process of the radio-controlled timepiece 1A can be accurately performed based on the TC.

[the third embodiment]

Next, a radio-controlled timepiece 1B according to a third embodiment of the present invention will be described with reference to the drawings.

FIG. 18 is a block diagram showing the configuration of a radio-controlled timepiece 1B according to the third embodiment. In the description of the radio-controlled timepiece 1B of the third embodiment, the same reference numerals are assigned to the same configurations as those of the radio-controlled timepieces 1 and 1A of the first and second embodiments described above, and their descriptions are simplified or omitted.

(1) Configuration of the radio-controlled timepiece 1B of the third embodiment

The radio-controlled timepiece 1B of the third embodiment is a timepiece in which the TC generator 44 of the radio-controlled timepiece 1 of the first embodiment is modified.

That is, the TC generating unit 44A in the radio-controlled timepiece 1B functions as the internal time reliability judging means and the time code generating means of the present invention.

Specifically, the TC generation unit 44A judges the reliability of the internal time counted by the time counter 43 in the radio-controlled timepiece 1B. As the judgment of the reliability of the internal time, for example, the storage unit 42 stores time adjustment history information related to the time at which the time adjustment processing is performed, and the TC generating unit 44A reads the time adjustment history information to judge the internal time. Reliability is high or low. Here, the TC generation unit 44A determines that the reliability of the internal time is low in the following cases, for example. That is, (1) when there is no history of corrected time in the time adjustment history information, that is, after the internal time is reset, the time adjustment process based on the reception of the standard radio wave has not succeeded even once; (2) recorded in the time When the time adjustment process based on the reception of standard radio waves has not been performed for more than a predetermined time (for example, one week) after the last time adjustment process in the correction history information; (3) The last time recorded in the time correction history information When the correction processing is time correction processing performed by user's operation input, TC generating unit 44A determines that the reliability of the internal time is low.

Furthermore, as described above, when it is determined that the reliability of the internal time is low, the TC generation unit 44A does not generate the reference TC. On the other hand, when it is judged that the reliability of the internal time is high because the above-mentioned situation is not satisfied, the TC generation unit 44A uses the time counted by the time counter (internal time) as in the TC generation unit 44 of the first embodiment. ), generate a benchmark TC.

(2) Operation of the radio-controlled timepiece 1B of the third embodiment

Next, the time adjustment operation of the radio-controlled timepiece 1B described above will be described.

FIG. 19 is a flowchart showing the time adjustment operation of the radio-controlled timepiece 1B.

As shown in FIG. 19 , in the time adjustment operation of the radio-controlled timepiece 1B of the third embodiment, first, the same processing as steps S101 and S102 in the radio-controlled timepiece 1 of the first embodiment is performed. That is, when it is the preset time for time adjustment, or when time adjustment based on radio wave reception is input, the control unit 47 executes the process of step S101 , that is, controls to start the time adjustment operation.

Then, the control unit 47 recognizes the radio wave type setting data through the process of step S102.

Thereafter, in the radio-controlled timepiece 1B, the reliability of the internal time counted by the time counter 43 is judged by the TC generation unit 44A (step S301 ).

In this step S301 , as described above, the TC generation unit 44A refers to the time adjustment history information stored in the storage unit 42 . Then, identify whether there is a history of time correction, the correction method when the time was last adjusted (whether it was time adjustment based on standard radio waves or manual time adjustment), and the time from the last time adjustment based on standard radio wave reception to the present. elapsed time so far.

Here, after resetting the internal time, the time adjustment based on the standard radio wave has not been successful even once and there is no time adjustment history; the last time adjustment is based on manual correction; and the last time adjustment based on the standard radio wave is carried out. After the received time is corrected, when a predetermined period or more has elapsed, the TC generation unit 44A determines that the reliability of the internal time is low.

Then, in this step S301, when the TC generation unit 44A determines that the reliability of the internal time is high, it executes the process of step S103 in the radio-controlled timepiece 1 of the first embodiment, and the subsequent steps are the same as in the first embodiment. , implement the processing of step S104 to step S114.

On the other hand, when the TC generating unit 44A determines in step S301 that the reliability of the internal time is low, the processes of steps S110 to S114 in the radio-controlled timepiece 1 of the first embodiment are performed. That is, as with general radio-controlled timepieces, no comparison is made between the received pulse duty ratio of the received standard radio wave and the reference duty ratio, and TC is decoded from the TCO signal of the received standard radio wave. Based on this TC, combined The internal clock is corrected by each counter value counted by the time counter 43 , and the display time of the display unit 5 is corrected.

(3) Effects of the radio-controlled timepiece 1B of the third embodiment

As described above, in the radio-controlled timepiece 1B of the third embodiment, the TC generator 44A also functions as internal time reliability judging means, and judges the reliability of the internal time counted by the time counter 43 . Furthermore, the TC generation unit 44A generates the reference TC only when the reliability of the internal time is high.

Therefore, an erroneous reference TC different from the actual current time is not generated due to a deviation in the internal time. Therefore, the VREF switching circuit 38 does not switch the reference voltage to a level based on the reference duty of such an inaccurate reference TC, and it is possible to prevent a time correction error based on the inaccurate reference TC. Accordingly, in step S106 , the highly reliable reference TC and the received pulse duty can be compared, and the VREF switching circuit 38 can output a more appropriate reference voltage to the binarization circuit 37 . Thereby, more accurate time adjustment processing can be performed based on the highly reliable reference TC.

And, when it is judged in step S301 that the reliability of the internal time is low, the reference voltage in the binarization circuit 37 is not switched, and the time correction process based on general standard radio waves is implemented. , the internal time of the time counter 43 is corrected.

Therefore, the reference TC based on the internal time can be generated from the next time the standard radio wave is received, and the reception level can be adjusted based on the reference TC, thereby performing more accurate time adjustment.

[Other implementations]

In addition, the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the range in which the object of the present invention can be achieved are also included in the present invention.

That is, in the above-described embodiment, the TC generation unit 44 generates the reference TC of the part corresponding to the time information of the time division, but the present invention is not limited thereto.

For example, the time counter 43 can also be configured as a counter that can count the year, month, and day in addition to the second counter, the minute counter, and the hour counter, and the TC generation unit 44 is used to generate current time information with minutes and hours and information from the current year. The base TC of one frame of calendar information such as the total day, year (last 2 digits of the Western calendar), and day of the week from January 1.

Moreover, the TC generation part 44 generates a reference TC of calendar information such as the total day, year, and week from January 1 of the current year, and the duty ratio judging part 45 can also compare and judge the reference duty ratio of the reference TC and the reference duty ratio of the reference TC. The reception pulse duty ratio of the data part related to the calendar information of the TCO signal.

In addition, in the above-described embodiment, the time adjustment operation is performed by manually inputting a time adjustment command by the user, and the time adjustment operation is performed at a preset timing reception time, for example, from 2:00 am to 5:00 am. Next, the reference TC is generated by the TC generation unit 44 every time the time adjustment operation is performed. However, for example, when the time adjustment operation is performed at the timing reception time, the reference TC stored in the storage unit 42 may be used. .

That is, when the time is adjusted for the first time at the timed reception time after the factory leaves the factory, or when the time is adjusted for the first time at the timed reception time after the user sets the timed reception time, the TC generation unit 44 uses the time of the time counter 43 The data generates a reference TC, and the duty ratio determination unit 45 compares and judges the generated reference TC with the reception pulse duty ratio of the TCO signal. In addition, at this time, the TC generation unit 44 stores the generated reference TC in the storage unit 42 . Then, at the next timing correction operation of the timing reception time, the duty ratio judging unit 45 compares and judges the reference duty ratio of the reference TC stored in the storage unit 42 and the pulse duty ratio of the received TCO signal.

In this configuration, the TC generation unit 44 does not need to generate the reference TC each time during the time adjustment operation of the timing reception time, so the processing load of the TC generation unit 44 can be reduced, and the speed-up and the speed of the time adjustment operation can be realized. Power saving.

In each of the above-described embodiments, the reference voltage VREF of the binarization circuit 37 and the initial value of the AGC characteristic in the AGC circuit 36A at the time of receiving processing may be preset fixed values, but may be stored in advance, for example. The value set at the time of the first receiving process is set, and the previous setting value is used as the initial value at the next receiving process.

In this case, in the receiving process in which the surrounding receiving environment is constant as at the time of regular reception, if the value set at the time of the previous reception is used as the initial value, the reference voltage and the AGC characteristic can be controlled so that the receiving There is a high possibility that the pulse duty ratio matches the reference duty ratio. Therefore, reception processing can be efficiently performed in a shorter time.

In addition, in the above-mentioned embodiment, the radio-controlled timepieces 1 and 1A are examples of the direct method without frequency conversion, but the invention is not limited to this, and may be a radio-controlled timepiece having a receiving circuit unit of a superheterodyne method, for example. In this case, the switching of the receiving frequency is not the switching of the bandpass filter, but only needs to be performed by switching the distribution frequency of the VCO (Voltage Controlled Oscillator) or the frequency division ratio.

Furthermore, in the first embodiment, switching of the reference voltage in the binarization circuit 37 is performed by switching the reference voltage in the VREF switching circuit 38 , but the present invention is not limited thereto. For example, a circuit for changing the bias value of the comparator by fixing the reference voltage may be provided, and further, the threshold value may be changed by providing a plurality of inverters for changing the capabilities of the Pch transistor and the Nch transistor.

Furthermore, in the above-mentioned third embodiment, the radio-controlled timepiece 1B has a function as an internal time reliability judgment unit added to the TC generation unit 44 of the radio-controlled timepiece 1 of the first embodiment, but the radio-controlled timepiece 1B may also be used in the second embodiment. A function as internal time reliability judging means is added to the TC generator 44 of the radio-controlled timepiece 1A. In this case, the same operational effect as that of the radio-controlled timepiece 1B of the third embodiment described above can be obtained, and accurate time adjustment processing with higher reliability can be performed.

In addition, specific configurations and procedures for carrying out the present invention can be appropriately changed to other configurations within the range in which the object of the present invention can be achieved.

Claims (12)

1. A radio-corrected timepiece, which receives a standard radio wave with a time code, and implements time correction according to the received standard radio wave, is characterized in that the radio-corrected clock has: a receiving unit, which receives the standard radio wave; a binarization unit, which binarizes the received signal of the standard radio wave according to a prescribed threshold, and outputs a binarized signal; a time counter, which counts the time; a time code generation unit, which generates a reference time code according to the time counted by the time counter; a duty ratio judging unit that calculates a pulse duty ratio of the binarized signal output from the binarization unit, and judges whether the calculated reception pulse duty ratio is the same as that generated by the time code generation unit The duty cycle of the reference time code is the same; a level switching unit that changes the threshold value with respect to the received signal when it is determined by the duty ratio judging unit that the reception pulse duty ratio does not match the duty ratio of the reference time code relative level; and a time code decoding unit that decodes the binarized signal when it is determined by the duty ratio judging unit that the received pulse duty ratio is consistent with the duty ratio of the reference time code And demodulate the time code. 2. The radio-controlled timepiece according to claim 1, wherein: When it is determined that the duty ratio of the received pulse is inconsistent with the duty ratio of the reference time code, the duty ratio judging unit judges that the duty ratio of the received pulse is larger than the duty ratio of the reference time code. is still smaller than the duty cycle of the reference time code, When the duty ratio of the received pulse is larger than the duty ratio of the reference time code, the level switching unit increases the relative level of the threshold with respect to the received signal, and when the duty ratio of the received pulse is When the duty ratio is smaller than the duty ratio of the reference time code, the level switching unit decreases the relative level of the threshold value to the received signal. 3. The radio-controlled timepiece according to claim 1 or 2, wherein: The radio-controlled timepiece has a threshold adjustment unit that changes the threshold in the binarization unit, When it is judged by the duty ratio judging unit that the duty ratio of the received pulse is inconsistent with the duty ratio of the reference time code, the level switching unit outputs to the threshold adjustment unit to change the two value the threshold control signal in the unit, The threshold adjustment unit changes the level of the threshold according to the control signal, and changes the relative level of the threshold with respect to the received signal. 4. The radio-controlled timepiece according to claim 1 or 2, wherein: The radio-controlled timepiece has: an amplifying unit that amplifies the received signal of the received standard electric wave; and an amplification adjustment unit that changes the amplification ratio of the received signal in the amplification unit, When it is judged by the duty ratio judging unit that the duty ratio of the received pulse is inconsistent with the duty ratio of the reference time code, the level switching unit outputs a signal to the amplification adjusting unit to change the amplification The control signal for signal amplification in the unit, The amplification adjustment unit changes the signal amplification ratio of the amplification unit according to the control signal, and changes the relative level of the threshold value to the received signal. 5. The radio-controlled timepiece according to claim 3, wherein: The radio-controlled timepiece has: a receiving circuit section having the receiving unit, the binarization unit, and the threshold adjustment unit; and a control circuit section having the time counter, the time code generating unit, the duty ratio judging unit, the time code decoding unit, and the level switching unit, the control circuit unit providing the receiving circuit with a control signal output from the level switching unit to control the receiving state of the standard radio wave in the receiving circuit unit, The receiving circuit unit has a control signal decoding unit that decodes the control signal output from the level switching unit of the control circuit unit and outputs the decoded signal to the threshold adjustment unit. Coded control signal. 6. The radio-controlled timepiece according to claim 4, wherein: The radio-controlled timepiece has: a reception circuit section having the reception unit, the amplification unit, the amplification adjustment unit, and the binarization unit; and a control circuit section having the time counter, the time code generating unit, the duty ratio judging unit, the time code decoding unit, and the level switching unit, the control circuit unit providing the receiving circuit with a control signal output from the level switching unit to control the receiving state of the standard radio wave in the receiving circuit unit, The receiving circuit unit has a control signal decoding unit that decodes the control signal output from the level switching unit of the control circuit unit and outputs the decoded signal to the amplification adjustment unit. code after the control signal. 7. The radio-controlled timepiece according to claim 5 or 6, wherein: The radio-controlled timepiece has a serial communication line connecting the receiving circuit unit and the control circuit unit, The control circuit unit outputs the control signal to the receiving circuit unit via the serial communication line in a serial communication manner, The receiving circuit part receives the control signal via the serial communication line in a serial communication manner, and decodes it by the control signal decoding unit. 8. The radio-controlled timepiece according to claim 1, wherein: After the receiving operation is started and the duty ratio judging unit judges that the reception pulse duty ratio matches the duty ratio of the reference time code, the level switching unit sets the threshold value relative to the The relative level of the received signal remains unchanged until the receiving operation is completed. 9. The radio-controlled timepiece according to claim 1, wherein: The level switching unit stores a relative level of the threshold value set at the time of receiving operation with respect to the received signal for each type of standard radio wave, In the next receiving operation, the stored relative level of the threshold value to the received signal is set as an initial setting value. 10. The radio-controlled timepiece according to claim 1, wherein: The receiving unit is configured to selectively receive a plurality of types of standard radio waves, The radio wave corrected timepiece has a reception radio wave setting unit that selects the type of the standard radio wave received by the reception unit, the time code generation unit generates a reference time code corresponding to the type of the standard radio wave selected by the reception radio wave setting unit, The duty ratio judging unit compares the duty ratio of the reference time code corresponding to the type of the standard radio wave selected by the received radio wave setting unit with the received pulse duty ratio of the binarized signal to make a judgment. . 11. The radio-controlled timepiece according to claim 1, wherein: The radio-controlled timepiece has an internal time reliability judging unit that judges the reliability of the time counted by the time counter, The time code generation unit generates the reference time code when the time counted by the time counter is judged to be reliable by the internal time reliability judgment unit. 12. A control method for a radio-controlled timepiece that receives a standard radio wave having a time code and performs time correction based on the received standard radio wave, characterized in that: receiving said standard radio wave, performing binarization on the received signal of the standard radio wave according to a prescribed threshold, and outputting a binarized signal, Generate a base timecode based on the time counted by the time counter, calculating the pulse duty ratio of the binarized signal, and judging whether the received pulse duty ratio is consistent with the duty ratio of the generated reference time code, When it is determined that the duty ratio of the received pulse does not match the duty ratio of the reference time code, the relative level of the threshold value relative to the received signal is changed, and this level changing process is repeated until the until the received pulse duty cycle is consistent with the duty cycle of the reference time code, Decoding the binarized signal and demodulating the time code when it is determined that the duty cycle of the received pulse coincides with the duty cycle of the reference time code.

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