JP2012189558A - Radio wave correction clock, and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio wave correction clock capable of correctly displaying that an environment is suitable for reception.SOLUTION: A radio wave correction clock 1 includes: an amplifier circuit 32 for amplifying a reception signal of a standard radio wave; an AGC circuit 36 for adjusting the gain of the amplifier circuit 32 in accordance with the strength of the reception signal; a binarization circuit 37 for binarizing the reception signal on the basis of a threshold to output a binarized signal; a second interval counter 411 for discriminating an error state of the reception signal on the basis of pulse change timing of the binarized signal; receiving state discriminating means 461 for discriminating a receiving state on the basis of an AGC signal of the AGC circuit 36 and a count value of the second interval counter 411; and receiving state display means 462 for displaying the discriminated receiving state.

Description

  The present invention relates to a radio-controlled timepiece that receives a standard radio wave having time information and corrects the time based on the received standard radio wave, and a control method therefor.

  Radio timepieces that can receive standard radio waves are known. The standard radio wave is amplitude-modulated, and the radio-controlled timepiece extracts the envelope of the received signal with a filter or the like in the receiving circuit, and then compares the envelope signal with a reference voltage by a comparator or the like. A binarization circuit for converting into values is provided. The radio timepiece obtains time information based on the time code signal obtained by the binarization circuit and displays the time.

  By the way, the standard radio wave receiving process usually requires several minutes (for example, 5 to 10 minutes). At this time, if the reception operation is performed in an environment that is not suitable for reception of the standard radio wave, there is a possibility that power is consumed wastefully. For this reason, in particular, in a radio timepiece driven by a battery such as a wristwatch, a user of the radio timepiece is required to grasp the reception environment in order to reduce power consumption.

  In view of this, a standard radio wave receiver that conducts demodulation processing by guiding a received signal that has received a standard radio wave to a demodulator through an AGC circuit and displaying the reception level of the standard radio wave on an LED display has been proposed ( Patent Document 1).

JP 2002-286884 A

Since Patent Document 1 displays a reception level, there is an advantage that reception in an environment where radio waves are weak, such as reception in a room, can be avoided.
On the other hand, in an environment where there is a lot of noise generated from an electronic device, the reception level also increases. For this reason, even when the reception level is high, acquisition of time data may fail due to the influence of noise. Therefore, simply displaying the reception level has a problem in that standard radio wave reception processing may be performed in an environment unsuitable for reception due to the influence of noise.

  An object of the present invention is to provide a radio-controlled timepiece that can accurately indicate that the environment is suitable for reception and a control method therefor.

  The present invention is a radio-controlled timepiece that receives a standard radio wave having a time code and corrects the time of an internal clock based on the received standard radio wave, an amplification circuit that amplifies the received signal of the standard radio wave, and the reception An auto gain control circuit that adjusts the gain of the amplifier circuit according to the strength of the signal; and binarization means that binarizes the received signal based on a predetermined threshold value and outputs a binarized signal; The pulse determination means for determining the error state of the received signal based on the pulse change timing of the binarized signal, the gain adjustment level of the amplifier circuit by the auto gain control circuit, and the determination result of the pulse determination means Receiving state determining means for determining the receiving state based on the receiving state, and receiving state displaying means for displaying the receiving state determined by the receiving state determining means. The features.

An auto gain control circuit (hereinafter also referred to as an AGC circuit) adjusts the gain of the amplifier circuit according to the level of the received signal. Specifically, an auto gain control voltage (hereinafter also referred to as AGC voltage) is output to the amplifier circuit, and the amplifier circuit adjusts the gain of the amplifier circuit based on the AGC voltage. At this time, the AGC circuit increases the gain of the amplifier circuit when the reception signal level is low, such as when the reception environment is a weak electric field environment. Further, when the reception signal level is high, as in the case where the reception environment is a noise environment, the gain of the amplifier circuit is decreased to control the output signal level of the amplifier circuit to be constant.
Therefore, if the adjustment level signal indicating the gain adjustment level of the amplifier circuit, for example, the signal indicating the AGC voltage value is obtained from the AGC circuit, the reception signal level can be determined.
The pulse determining means determines an error state of the received signal based on the pulse change timing of the binarized signal. That is, since bit data is transmitted at intervals of 1 second with a standard radio wave, the pulse change timing in the received signal should also occur at intervals of 1 second. However, in an environment where there is a lot of noise, the received signal waveform is disturbed due to the influence of noise, so the pulse change timing is likely to be shifted from 1 second. Therefore, if the pulse change timing for a predetermined period, for example, 20 seconds is detected and the number of pulses changed at intervals of 1 second is counted, it can be determined that there is little noise when the count value is large and there is much noise when the count value is small. .
The reception state determination unit of the present invention determines the reception environment by combining the signal intensity based on the AGC voltage value and the noise level of the pulse determination unit. For this reason, when the signal level is increased due to the influence of noise, there is a risk of erroneous determination that the reception environment is good when the reception environment is determined only by the conventional AGC voltage. Since the presence or absence of noise is also determined based on the count value of the pulse determination means, the reception environment can be determined accurately. Therefore, the reception status display means can display an accurate reception environment, and the user can easily determine whether to continue reception at the current location or whether to stop reception and move to another location. For this reason, it is possible to prevent the reception process from being continued in a bad reception environment, and it is possible to eliminate a useless reception process.

  In the radio-controlled timepiece of the present invention, the reception state determination unit determines the strength of the reception signal from the gain adjustment level of the amplifier circuit, and determines the noise state from the determination result of the pulse determination unit, The reception status display means preferably displays the strength of the reception signal and the noise status separately.

According to the present invention, since the strength of the reception strength and the noise state can be displayed separately, the user can determine the reason why the reception state is not good. For example, if it is displayed that there is little noise but the reception strength is weak, it can be determined that the signal is received in a place where the radio wave is weak, such as indoors, and you can move to a place where the radio wave is strong, such as near the window, and receive it. I can understand that.
Further, if there is a lot of noise, it can be determined that it is close to the noise source, and it can be grasped that it is only necessary to move away from the noise source or to stop the electrical device that is the noise generating source.
Therefore, since the user can grasp the details of the reception state, it is possible to take an appropriate measure for receiving the standard radio wave.

  The radio-controlled timepiece according to the present invention includes a manual reception mode in which reception is started by an operation of an external operation member, and an automatic reception mode in which reception is started when the internal time reaches a predetermined time. It is preferable that the reception state is displayed at least when operating in the manual reception mode.

  According to this invention, since the reception state is displayed when operating in the manual reception mode, the reception state can be displayed when necessary for the user, and the convenience for the user can be improved. In other words, when operating in the manual reception mode, the user has started the reception operation on his / her own will, so if the reception status is displayed, the user can easily see whether the location is suitable for reception by viewing the display. This makes it possible to prevent the wasteful power consumption by continuing the reception operation at a place not suitable for reception.

  In the radio-controlled timepiece according to the aspect of the invention, it is preferable that the reception state display unit displays a reception state using a time display unit that displays time.

  According to the present invention, since the radio wave reception status is displayed using the time display means such as the second hand, a special mechanism for displaying the reception status can be eliminated, and the number of parts of the watch can be reduced. The cost can be reduced and the design of the watch can be simplified to improve the design.

  In the radio-controlled timepiece of the present invention, it is preferable that the reception process is stopped when a reception stop operation is performed by an external operation member while the reception state is displayed by the reception state display means.

  According to the present invention, the reception status display allows the user to easily determine whether the place is suitable for reception, and if it is determined that the place is not suitable for reception, the user can stop the reception with the external operation member. Since reception processing can be stopped, it is possible to prevent wasteful power consumption.

  The present invention relates to a method for controlling a radio-controlled timepiece that receives a standard radio wave having a time code and corrects the time of an internal clock based on the received standard radio wave, and an amplification circuit that amplifies the received signal of the standard radio wave An automatic gain control circuit for adjusting the gain of the amplification circuit according to the strength of the received signal, and binarization for binarizing the received signal based on a predetermined threshold value and outputting a binarized signal And determining the strength of the received signal based on the gain adjustment level of the amplifier circuit by the auto gain control circuit, and determining the error state of the received signal based on the pulse change timing of the binarized signal. And determining and displaying the reception state based on the strength of the reception signal and the error state of the reception signal.

  According to the present invention, the reception environment can be determined by combining the signal strength based on the AGC voltage value and the noise level determined by the pulse determination means, as in the radio-controlled timepiece. For this reason, compared with the case where the reception environment is determined only by the conventional AGC voltage, the presence / absence of noise is also determined, so that the reception environment can be accurately determined.

It is a block diagram which shows the structure of the electromagnetic wave correction watch which concerns on 1st Embodiment. It is a figure which shows the relationship between the AGC voltage and gain in a 1st amplifier circuit. It is a circuit diagram which shows the structure of an AGC circuit. It is a figure which shows the relationship between the input level of the received signal in an AGC circuit, and an AGC voltage. It is a figure which shows the time code format of the standard radio wave "JJY" in Japan. It is a figure which shows each signal of the standard radio wave "JJY" in Japan. It is a figure which shows the time code format of the standard radio wave "WWVB" in the United States. It is a figure which shows each signal of the standard radio wave "WWVB" in the United States. It is a figure which shows the waveform of the TCO signal which binarized based on the reference | standard voltage after the envelope detection of the original waveform concerning TC contained in a standard radio wave, and the received signal of this standard radio wave. It is a figure explaining the counting method in a second interval counter. It is a flowchart which shows the time correction operation | movement of a radio wave correction clock. It is a figure which shows the relationship between an AGC voltage value, the count value of a second interval counter, and a receiving state. The figure explaining the display operation of a radio wave reception state. The figure explaining the display operation of the electric wave reception state concerning a modification. The figure explaining the display operation | movement of the electromagnetic wave reception state which concerns on another modification.

[First Embodiment]
(1) Configuration of the radio-controlled timepiece 1 As shown in FIG. 1, the radio-controlled timepiece 1 includes an antenna 2, a receiving circuit unit 3, a control circuit unit 4, a display unit 5, an external operation member 6, and a reference. And a crystal oscillator 47 for a clock.
The antenna 2 receives a long-wave standard radio wave (hereinafter referred to as “standard radio wave”), and outputs the received standard radio wave to the receiving circuit unit 3.
The receiving circuit unit 3 demodulates the received signal of the standard radio wave received by the antenna 2 and outputs it to the control circuit unit 4 as TCO (Time Code Out). A detailed description of the receiving circuit unit 3 will be described later.

  The control circuit unit 4 decodes the input TCO to generate a TC (time code), and sets the time of the time counter 44 based on the generated TC. Further, the control circuit unit 4 performs control to display the time of the time counter 44 on the display unit 5. Further, the control circuit unit 4 outputs a control signal to the reception circuit unit 3. The detailed description of the control circuit unit 4 will be described later.

  The display unit 5 is driven and controlled by the drive circuit unit 45 of the control circuit unit 4 and displays the time counted by the time counter 44. For example, the display unit 5 may include a liquid crystal panel and display the time on the liquid crystal panel. The display unit 5 may include a dial and a pointer, and the control circuit unit 4 may move the pointer to display the time. There may be.

  The external operation member 6 is constituted by, for example, a crown or a setting button, and outputs a predetermined operation signal to the control circuit unit 4 when operated by a user. As the operation signal, for example, the radio wave type setting data for setting the type of standard radio wave received by the antenna 2 (for example, JJY in Japan, WWVB in the United States, DCF77 in Germany, BPC in China, etc.), standard radio wave For example, correction request information indicating that the time is corrected by receiving.

  The crystal oscillator 47 for the reference clock outputs a predetermined reference signal (reference clock, for example, a 32.768 kHz signal). The reference signal output from the crystal oscillator 47 is input to the control circuit unit 4. ing. This signal is frequency-divided into a signal of 1 Hz by a frequency dividing circuit in the control unit 46.

(2) Configuration of Reception Circuit Unit 3 As shown in FIG. 1, the reception circuit unit 3 is abbreviated as a tuning circuit 31, a first amplification circuit 32, and a band-pass filter (hereinafter referred to as “BPF”). 33), second amplifier circuit 34, envelope detection circuit 35, AGC (Auto Gain Control) circuit 36, binarization circuit 37 as binarization means, and control signal decoding means The decoding circuit 39 is provided.

  The tuning circuit 31 includes a capacitor, and the tuning circuit 31 and the antenna 2 constitute a parallel resonance circuit. The tuning circuit 31 causes the antenna 2 to receive a radio wave having a specific frequency. The tuning circuit 31 converts the standard radio wave received by the antenna 2 into a voltage signal and outputs the voltage signal to the first amplifier circuit 32. In the receiving circuit unit 3 of the present embodiment, in addition to the Japanese standard radio wave “JJY”, the standard radio wave “WWVB” in the United States, the standard radio wave “DCF77” in Germany, the standard radio wave “BPC” in China, etc. It is configured to receive standard radio waves.

The first amplifier circuit 32 adjusts the gain in accordance with a signal (AGC voltage) input from an AGC circuit 36 described later, and amplifies the received signal input from the tuning circuit 31 so as to be input to the BPF 33 as a constant amplitude.
Here, the relationship between the AGC voltage and the gain in the first amplifier circuit 32 is as shown in FIG. That is, when the AGC voltage is in the range of 0.0 to 0.2 V, the gain in the first amplifier circuit 32 is set to 80 dB, and when the AGC voltage is 0.2 V or more, the gain is approximately proportional to the AGC voltage. When the AGC voltage is in the range of 0.9 to 1.0 V, the gain is about 0.0 dB. The AGC voltage input to the first amplifier circuit 32 is actually set to a variable width of about 0.1 to 0.9V.

  The band pass filter (BPF) 33 is a filter that extracts a signal in a desired frequency band. That is, by passing through the BPF 33, components other than the carrier wave component are removed from the received signal input from the first amplifier circuit 32.

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

  The envelope detection circuit 35 includes a rectifier (not shown) and a low-pass filter (LPF) (not shown). The envelope detection circuit 35 rectifies and filters the received signal input from the second amplifier circuit 34, and performs filtering. The envelope signal thus obtained is output to the AGC circuit 36 and the binarization circuit 37.

[Configuration of AGC circuit]
The AGC circuit 36 outputs a signal (AGC voltage) for determining a gain when the first amplification circuit 32 amplifies the reception signal based on the reception signal input from the envelope detection circuit 35. For example, A circuit as shown in FIG. 3 can be used.

  That is, the AGC circuit 36 includes a comparator 361, an AGC capacitor 362, first and second constant current sources 363 and 364, an inverter 370, a pull-down resistor 372, and a constant voltage source 373 that outputs an AGC reference voltage. I have.

The comparator 361 includes two input terminals. One input terminal (minus input) is connected to a constant voltage source 373 that is connected to a low potential power source VSS and outputs an AGC reference voltage, and the other input terminal (plus input) is connected to the envelope detection circuit 35. Has been.
For this reason, the comparator 361 outputs a Hi level signal when the voltage of the envelope signal input from the envelope detection circuit 35 is equal to or higher than the AGC reference voltage, and outputs a Low level signal when the voltage is lower than the AGC reference voltage. Is output.

The first constant current source 363 is connected between the power supply VDD having a higher potential than the power supply VSS and the AGC capacitor 362. The first constant current source 363 is turned on when a Hi level signal is output from the comparator 361 and is turned off when a Low level signal is output.
The second constant current source 364 is connected between the AGC capacitor 362 and the power source VSS. Since the inverter 370 is disposed between the comparator 361 and the second constant current source 364, the second constant current source 364 is turned on when the Low level signal is output from the comparator 361, and is at the Hi level. When a signal is output, it is turned off.

Accordingly, when a Hi level signal is output from the comparator 361, the first constant current source 363 is turned on and the second constant current source 364 is turned off, and the constant current source 363 passes a constant current to cause the AGC capacitor 362 is charged.
When the AGC capacitor 362 is charged, the AGC voltage (AGC control voltage) input to the first amplifier circuit 32 increases.
On the other hand, when a low level signal is output from the comparator 361, the first constant current source 363 is turned off, the second constant current source 364 is turned on, and the constant current source 364 passes a constant value of current so that the AGC capacitor 362 is discharged.
When the AGC capacitor 362 is discharged, the AGC voltage input to the first amplifier circuit 32 decreases.

  Therefore, as shown in FIG. 4, in the AGC circuit 36, when the input level of the reception signal input to the first amplifier circuit 32 increases, the AGC voltage also increases, and the AGC voltage changes in proportion to the input signal level. . For this reason, the strength of the input signal can be grasped by monitoring the AGC voltage.

As shown in FIG. 2, the first amplifier circuit 32 of the present embodiment decreases the gain (gain) of the first amplifier circuit 32 when the AGC voltage increases, and the first amplifier circuit 32 when the AGC voltage decreases. The gain (gain) of 32 is configured to be large.
Therefore, when the input signal level increases, the AGC voltage output from the AGC circuit 36 to the first amplifier circuit 32 increases, and the gain in the first amplifier circuit 32 decreases.
On the other hand, when the input signal level decreases, the AGC voltage output from the AGC circuit 36 to the first amplifier circuit 32 decreases, and the gain in the first amplifier circuit 32 increases.
Therefore, the AGC circuit 36 and the first amplifier circuit 32 can automatically adjust the received signal so as to have a constant amplitude.

  The binarization circuit 37 is composed of, for example, a binarization comparator. This binarization comparator is a comparator having hysteresis, and compares the envelope signal inputted from the envelope detection circuit 35 with a reference voltage (threshold value) having a predetermined voltage, thereby obtaining a binary signal. That is, a TCO signal is output. The envelope signal is noisy, and flickering of the TCO signal can be suppressed by providing a binary comparator with a hysteresis of several mV.

  Specifically, the binarization circuit 37 uses a signal having an H level (high level) voltage when the voltage of the envelope signal exceeds the reference voltage, and the voltage of the envelope signal sets the reference voltage. If it is lower, an L level (low level) signal having a voltage value lower than that of the H level signal is output to the control circuit unit 4 as a TCO signal. When the voltage of the envelope signal is higher than the reference voltage, the control circuit unit 4 uses the L level as the TCO signal, and the L level when the voltage of the envelope signal is lower than the reference voltage. It is also possible to configure so as to output to

  The binarization circuit 37 may be one using an AD converter and a level selection unit. For example, when a 10-bit AD converter is used as an AD converter that digitizes an analog signal after envelope detection, 10 digital signals are output to the level selection unit. Therefore, the level selection unit may binarize the 10-bit signal of the AD converter at a predetermined level based on the control signal to obtain a TCO output.

  The decode circuit 39 is connected to the control circuit unit 4 described later via a serial communication line. The decode circuit 39 decodes the control signal input from the control circuit unit 4 and outputs it to the binarization circuit 37 and the like.

(3) Configuration of Control Circuit Unit 4 The control circuit unit 4 controls the operation of the reception circuit unit 3 as described above. Specifically, the control circuit unit 4 receives signals from the decoding circuit 39 of the reception circuit unit 3. A control signal for operating the circuit unit 3 and a control signal for setting the reference voltage of the binarization circuit 37 are output. Further, the control circuit unit 4 decodes the TCO signal input from the binarization circuit 37 and sets the time of the time counter 44 based on the time code generated by decoding. Further, the control circuit unit 4 performs control to display the time of the time counter 44 on the display unit 5.
As shown in FIG. 1, the control circuit unit 4 includes a TCO decoding unit 41 as a time code decoding unit, a storage unit 42 as a storage unit, a time counter 44, a drive circuit unit 45, a control unit 46, It is configured with. Note that the reference signal output from the crystal resonator 47 is input to the control unit 46.

  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) having date information and time information included in the TCO signal. Then, the TCO decoding unit 41 outputs the extracted TC to the control unit 46. The TCO decoding unit 41 of the present embodiment decodes and outputs time codes of a plurality of types of standard radio waves such as Japanese standard radio JJY, American standard radio WWVB, German standard radio DCF77, Chinese standard radio BPC, etc. It is configured to be able to.

  Further, the TCO decoding unit 41 is provided with a second interval counter 411 as pulse determining means. Details of the configuration of the second interval counter 411 will be described later.

  The storage unit 42 is a memory that stores various data, programs, and the like necessary for controlling the reception circuit unit 3 by the control circuit unit 4.

The time counter 44 counts time based on the reference signal output from the crystal resonator 47. Specifically, the time counter 44 includes a second counter that counts seconds, a minute counter that counts minutes, and an hour counter that counts hours.
For example, when a 1 Hz reference signal is output from the crystal unit 47, the second counter is a counter that loops the signal at 60 counts, that is, 60 seconds. The minute counter is a counter that counts once when the reference signal of 1 Hz is multiplied 60 times and loops at 60 counts, that is, 60 minutes. The hour counter is a counter that counts once when the 1 Hz reference signal is coefficiented 3600 times and loops in 24 counts, that is, 24 hours.
The minute counter may be configured to count up the minute counter by outputting a signal from the second counter to the minute counter every time the second counter counts 60 times. Similarly, the hour counter may be configured to output a signal from the minute counter to the hour counter every time the minute counter counts 60 to count up the hour counter.

  The drive circuit unit 45 controls the display state of the display unit 5 based on the time display control signal output from the control unit 46, and controls the display unit 5 to display the time. 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 45 controls the liquid crystal panel based on the time display control signal and displays the time on the liquid crystal panel. Let When the display unit 5 has a dial and a pointer, the drive circuit unit 45 outputs a pulse signal to the stepping motor that drives the pointer and moves the pointer by the driving force of the stepping motor.

  Further, when the reception state display control signal is output from the control unit 46, the drive circuit unit 45 controls the display unit 5 to display the reception state. Details of the reception state display control will be described later.

  The control unit 46 is driven based on the drive frequency input from the crystal unit 47 and performs various control processes. That is, the control unit 46 controls the correction of the count of the time counter 44 by outputting the TC input from the TCO decoding unit 41 to the time counter 44. Further, the control unit 46 outputs a time display control signal for displaying the time counted by the time counter 44 on the display unit 5 to the drive circuit unit 45.

Further, the control unit 46 includes a reception state determination unit 461 and a reception state display unit 462. The reception state determination unit 461 determines the strength of the reception signal based on the AGC signal output from the AGC circuit 36, and determines the noise state based on the determination result of the second interval counter 411 which is a pulse determination unit. The reception state is determined from the result.
The reception state display unit 462 outputs a display control signal for displaying the reception state determined by the reception state determination unit 461 on the display unit 5 to the drive circuit unit 45.

The control unit 46 and the decode circuit 39 are connected by a serial communication line, and the control signal is input to the decode circuit 39 via the serial communication line. As a result, a control signal for controlling the receiving circuit unit 3 can be output to the receiving circuit unit 3 via the decoding circuit 39.
Here, in the serial communication between the control unit 46 and the receiving circuit unit 3, a two-line synchronous interface capable of bidirectional communication between the control unit 46 and the receiving circuit unit 3 is used. Serial communication may be performed. In such a case, after outputting a control signal from the control unit 46 to the receiving circuit unit 3, the receiving circuit unit 3 again transfers the received and recognized control signal to the control unit 46 and outputs it from the control unit 46. By confirming the data difference between the control signal and the input control signal, serial communication with higher reliability can be performed.

[Second interval counter]
Next, the second interval counter 411 will be described.
The second interval counter 411 detects the pulse rising timing or pulse falling timing of the TCO signal output from the binarization circuit 37.
Whether the pulse rising timing is detected or the pulse falling timing is detected is set according to the type of the received standard radio wave.
For example, the Japanese standard radio wave (JJY) shown in FIGS. 5 and 6 is detected at the pulse rising timing, and the American reception radio wave (WWVB) shown in FIGS. 7 and 8 is detected at the pulse falling timing.

Here, FIG. 5 shows a JJY time code format, and FIG. 6 shows a JJY signal pulse. FIG. 7 shows a WWVB time code format, and FIG. 8 shows a WWVB signal pulse.
In any standard radio wave, signals are transmitted at intervals of 1 second as shown in FIGS. At this time, in JJY, as shown in FIG. 6, the amplitude of the signal changes from the low level to the high level at the start timing of the pulse every second. On the other hand, in WWVB, as shown in FIG. 8, the amplitude of the signal changes from the high level to the low level at the start timing of the pulse every second.

  In the present embodiment, the TCO output from the binarization circuit 37 of the reception circuit unit 3 changes from low to high at the pulse start timing every second in the case of JJY, and from high to low in the case of WWVB. The level is supposed to change. For this reason, the second interval counter 411 detects the pulse rising timing during reception of JJY, and detects the pulse falling timing during reception of WWVB.

Here, the reason why the noise state can be determined by detecting the change timing of the pulse rise or fall will be described.
For example, in the case of JJY, the original waveform of the standard radio wave is a rectangular wave as shown by A1 in FIG. However, as shown by A2 in FIG. 9, the waveform from the envelope detection circuit 35 is an amplification waveform of a minute signal, and there is a lot of noise generated by electronic equipment in the long wave frequency band (30 k to 300 kHz). In actual use environment, it contains a lot of noise.

In such a noisy environment, the TCO waveform A3 output from the binarization circuit 37 is disturbed, and the rising timing of the pulse also deviates from the original waveform.
Therefore, the second interval counter 411 checks the pulse change timing by the method shown in FIG.
That is, when JJY is received, the second interval counter 411 indicates that the rising edge of the pulse is within a predetermined range from the reference timing of the one second interval obtained by the second synchronization processing of the TCO signal (for example, ± 62.5 ms). Count the number of times that is within the range) and grasp the reception status. When the reception state is bad due to a noisy environment, as shown in FIG. 9, the rising timing of the pulse is deviated from the timing of the 1-second interval, so it often does not fall within the predetermined range, and the count value is also Get smaller.
On the other hand, when the reception state is good due to an environment with little noise, the number of cases often falls within the predetermined range, and the count value also increases.

Therefore, the second interval counter 411 performs sampling for 20 seconds, for example, and can determine the noise state by the count number (minimum value 0 to maximum value 20) at the end of the sampling period.
Note that the reception state determination method by the second interval counter 411 utilizes a processing method for synchronizing seconds. In the second synchronization, the rising timing of each pulse is measured, and the average is taken as a reference timing.
If WWVB is received, it may be detected at the pulse falling timing as described above.

(4) Operation of the radio-controlled timepiece 1 Next, the time-correcting operation using the standard radio wave in the radio-controlled timepiece 1 as described above will be described.
FIG. 11 is a flowchart showing the time adjustment operation of the radio-controlled timepiece 1.

  When the radio-controlled timepiece 1 is manufactured, for example, JJY is set as the type of standard radio wave to be received. Therefore, at the time of manufacturing the receiving circuit, the radio-controlled timepiece 1 is set to a state in which the TC included in JJY can be decoded. The type of radio wave to be received is basically the standard radio wave at the time of previous reception, but can be set by the user by operating the external operation member 6 after the previous reception.

In FIG. 11, when a manual reception operation is performed by the external operation member 6 (S1), the control unit 46 of the radio-controlled timepiece 1 starts a manual reception process (S2). That is, the reception process normally includes an automatic reception mode in which reception is automatically started at a predetermined time set in advance and a manual reception mode in which reception is started by the user operating the external operation member 6.
The automatic reception time is usually set to a time zone with little city noise, such as 2 to 4 am. In most cases, the user is not looking at the radio-controlled timepiece 1 during this time period. For this reason, in the present embodiment, the process of FIG. 11 is not performed during the automatic reception process, and the process of FIG. 11 is performed only in the manual reception mode where the user is surely looking at the radio-controlled timepiece 1.

When the reception process is started, the control unit 46 selects a receiving station (standard radio wave type) (S3). As described above, the initial setting of the receiving station is JJY, but in principle after that, the previous receiving station is set, and when the user selects a station, the selected station is set.
When the receiving station is selected, the control unit 46 receives the AGC signal output from the AGC circuit 36, and acquires AGC voltage data (S4).

Next, the control unit 46 performs second synchronization processing based on the TCO signal output from the binarization circuit 37 (S5). That is, the reception circuit unit 3 converts the standard radio wave received by the antenna 2 into a voltage signal (reception signal) by the tuning circuit 31, and the first amplification circuit 32, the bandpass filter 33, the second amplification circuit 34, The envelope detection circuit 35 amplifies the received signal to a predetermined level, extracts a signal in a desired frequency band, and rectifies and filters it to obtain an envelope signal. Further, the envelope signal is binarized by the binarization circuit 37 to obtain a TCO signal, and this TCO signal is output to the control circuit unit 4.
Therefore, the control unit 46 establishes second synchronization by confirming whether the rising timing of the TCO signal input to the TCO decoding unit 41 is 1 second.
Further, the control unit 46 uses the second interval counter 411 to measure a one-second interval pulse in a TCO signal for a predetermined time (for example, 20 seconds).

Then, the reception state determination unit 461 of the control unit 46 determines and displays the reception state from the count value of the second interval counter 411 and the AGC signal (AGC voltage value) (S7).
Here, a state display determination method by the reception state determination unit 461 will be described. FIG. 12 shows a relationship table between the AGC voltage and the count value of the second interval counter 411.

  As shown in FIG. 12, the reception state determination unit 461 has an AGC voltage of 0.8 V or more, 0.2 to 0.8 V (greater than 0.2 V and less than 0.8 V), 0.2 V or less. It is divided into three stages. The reception state determination unit 461 determines that the signal strength of the standard radio wave is strong (radio wave strength) if the AGC voltage is 0.8 V or higher, and the signal strength is medium (0.2 to 0.8 V). If it is 0.2 V or less, it is determined that the signal intensity is weak (radio wave weak).

  In addition, the reception state determination unit 461 sets the count value of the second interval counter 411 to 10 or less, 10 to 18 (greater than 10 and 18) in the measurement for 20 seconds (maximum count value = 20). Less), and is divided into three stages of 18 or more. The reception state determination unit 461 determines that there is a lot of noise (large noise) if the count value is 10 or less, and determines that the noise is medium (medium) if it is 10 to 18, and if it is 18 or more. It is determined that there is little noise (low noise).

  Note that the second interval counter 411 can perform measurement for a longer time such as 40 to 60 seconds, but in this case, the time until the reception state is displayed becomes longer and the usability is deteriorated. However, the longer the measurement time, the more accurately the noise environment can be grasped with high resolution. For example, if measurement is performed for 60 seconds, noise generated every 60 seconds can also be detected.

In the present embodiment, as shown in FIG. 13, the reception state is displayed using the second hand 53 among the hands (hour hand 51, minute hand 52, second hand 53) as the display unit 5.
FIG. 13A shows a display during reception, from the start of reception by manual operation (S2) until the reception status display (S7) is executed. In this case, the reception state display means 462 moves the second hand 53 to the 12 o'clock position via the drive circuit unit 45 and stops the hand movement of the pointer. At the 12 o'clock position, an R (Receive) character indicating that reception is in progress is also displayed. As a result, the user can confirm that the reception process has been started because the second hand 53 whose movement has been stopped is at the 12 o'clock position. In the present embodiment, the receiving operation is started by pressing the button 61 that is the external operation member 6.

  On the other hand, in the reception state display process of S7, the reception state display unit 462 moves the second hand 53 and displays the reception state based on the result of determination by the reception state determination unit 461 based on the table of FIG. In the present embodiment, the left half of the dial 7 of the radio-controlled timepiece 1 indicates the strength of the radio wave, and the right half indicates the noise environment.

For example, when the count value of the second interval counter 411 is 18 or more and the AGC voltage is 0.8 V or more (in the case of (1) in Table 12), the reception state determination unit 461 is very strong in radio waves and has little noise. Determine that the environment is good.
Therefore, as shown in FIG. 13B, the reception state display means 462 rotates the second hand 53 clockwise to return to the 12 o'clock position where “R (Receive)” is displayed, and the reception state is good. Display that there is.

When the count value is 10 or less (in the case of (7), (8), and (9) in Table 12), the reception state determination unit 461 has a lot of noise and the reception environment is extremely bad, and reception can be successful. It is determined that there is almost no sex.
Therefore, as shown in FIG. 13C, the reception state display means 462 moves the second hand 53 to the 6 o'clock position displayed as “N (NG)” by fast-forwarding. In the manual or the like, if the second hand 53 is moved to the 6 o'clock position in the reception status display (S7), the reception environment is bad, so it is only necessary to urge the user to stop receiving and change the location.

Further, when the count value is 10 to 18 and the AGC voltage is larger than 0.2 V (in the case of (4, 5) in Table 12), the reception state discriminating means 461 has an interval of 1 second although the signal level is somewhat large. Since there are several error pulses that could not be detected in step 1, it is determined that the signal level may be due to noise. In this case, it is necessary to be cautious that the noise source that interferes with radio wave reception is near, and notify the user that the standard radio wave may interfere with the noise, and move away from the noise source. It is desirable to encourage
Therefore, the reception state display means 462 moves the second hand 53 to the 3 o'clock position where “I (Interfere)” is displayed as shown in FIG. In the manual or the like, when the second hand 53 is moved to the 3 o'clock position in the reception state display (S7), the noise source is close, so that it is only necessary to urge the user to change the location away from the noise source.

In addition, when the AGC voltage is 0.2 V or less and the signal intensity is weak, but the count value is 10 or more and is accurate to some extent (in the case of (3, 6) in Table 12), the reception state determination unit 461 is noisy. However, it is determined that there is a possibility of reception failure due to weak radio waves.
For this reason, as shown in FIG. 13E, the reception status display means 462 moves the second hand 53 to 8 o'clock, which is displayed as “L (Low)” and indicates that the radio wave is weak, by fast-forwarding. In the manual or the like, when the second hand 53 is moved to the 8 o'clock position in the reception status display (S7), the radio wave is weak, and therefore it is only necessary to urge the user to move outdoors where the radio wave becomes strong.

Furthermore, when the AGC voltage is 0.2 to 0.8 V and the radio wave is moderately strong and the count value is 18 or higher (in the case of (2) in Table 12), the reception state determination unit 461 However, it is determined that there is no problem in reception.
Therefore, as shown in FIG. 13 (F), the reception status display means 462 moves the second hand 53 to 10 o'clock position indicating “M (Mid)” and indicating that the radio wave is in a fast forward position. In the manual or the like, it should be noted that when the second hand 53 is moved to the 10 o'clock position in the reception status display (S7), the radio wave is medium and the noise is low, so that the reception can be continued as it is. .

  If the button 61 is pressed again and a reception stop button operation is performed during such reception state display (S8), the control unit 46 stops reception (S9). That is, the user can immediately stop the reception when the reception state display is bad and the reception state is bad. In this case, manual reception can be performed again by moving a place or stopping an electrical device that is a nearby noise source.

  On the other hand, if the button operation for stopping reception has not been performed (No in S8), the control unit 46 determines whether or not the second synchronization is successful based on the count value of the second interval counter 411 (S10). In other words, since the count value of the second interval counter 411 is the number of pulse rises detected at one second intervals, it can be said that when the count value is large, the second synchronization is also successful. Therefore, in the present embodiment, the control unit 46 determines that the second synchronization is successful if the count value is 11 or more, and fails if the count value is 10 or less.

If it is determined in S10 that the second synchronization has failed (No in S10), the control unit 46 determines whether or not reception of all stations has been completed (S11). If the answer is No in S11, the control unit 46 returns to the selection of the receiving station in S3, selects another station, and continues the process.
On the other hand, in the case of Yes in S11, it is determined that the standard radio wave cannot be received, and the control unit 46 stops the reception (S9).

  If it is determined in S10 that the second synchronization is successful, the control unit 46 acquires a marker indicating the 0-second position of the time code and performs frame synchronization (S12). For example, in the Japanese standard radio wave JJY, the portion where the P0 and M markers are continuous is the start point of the time code, and frame synchronization can be established by detecting this continuous marker.

  When the frame synchronization is established by acquiring the marker, the control unit 46 uses the TCO decoding unit 41 to decode the TCO signal output from the binarization circuit 37 and acquire the time code (TC) (S13).

Then, the control unit 46 determines whether or not an accurate TC has been acquired (S14). For example, the control unit 46 determines whether or not the acquired time data is consistent depending on whether or not each time data obtained by acquiring a plurality of continuous time codes is at one minute intervals.
When it determines with No by S14, the control part 46 judges whether predetermined time (for example, 5 minutes) passed since the reception start (S15). In the case of No in S15, the control unit 46 returns to the time code acquisition in S13 and continues the process.
On the other hand, in the case of Yes in S15, the controller 46 determines that the standard radio wave is not received even if the reception process is continued, and that power is wasted, and the control unit 46 stops receiving (S9). ).

In the case of Yes in S14, since the accurate TC has been acquired, the control unit 46 ends the reception operation of the standard radio wave (S16). Thereafter, the control unit 46 outputs the acquired TC to the time counter 44, corrects each count value of the time counter 44, and corrects the display time of the display unit 5 (S17). And it returns to normal hand movement.
When the reception is completed in S9, the time data could not be acquired, so the time counter 44 is not corrected and the routine returns to normal operation.

[Effects of Embodiment]
In the radio-controlled timepiece 1 of this embodiment, the reception environment is determined based on the AGC signal indicating the AGC voltage value and the count value of the second interval counter 411. For this reason, the reception environment can be determined not only by the signal level but also by the presence or absence of noise. Therefore, even when the signal level is increased due to the influence of noise, the reception state determination unit 461 of the present embodiment also determines the presence or absence of noise based on the count value of the second interval counter 411. Can be judged accurately.

Furthermore, since the reception state can be determined and displayed immediately after the start of the reception process, the user can grasp the current reception environment and can prevent the reception from continuing while the reception state is bad.
For this reason, for example, the radio-controlled timepiece 1 can be moved away from a noise source or moved to a place with good reception conditions such as a window if it is indoors. Probability of correction can be improved.

  Further, when the noise is large, the second hand 53 moves to the 6 o'clock position, and when the noise is present, the second hand 53 moves to the 3 o'clock position, so that the noise state can be displayed. For this reason, if the radio-controlled timepiece 1 is brought close to a noise source, the display of noise changes in the display of the reception state, so that the noise source can be easily found.

Further, since the radio wave reception status is displayed using the second hand 53, a special mechanism for displaying the reception status can be eliminated, the number of parts of the watch can be reduced, and the cost can be reduced. Design can be simplified and design can be improved.
Further, since the symbols R, I, N, L, and M indicating the reception state are displayed around the dial 7, the user can easily grasp the reception state by looking at the symbols indicated by the second hand 53.
In addition, L and M indicating the strength of the radio wave are arranged on the left half of the dial 7, I indicating the noise environment is arranged on the right half, and the reception radio wave state is NG at 6 o'clock on the dial 7. When the position is good, the dial 7 is set to the 12 o'clock position. Therefore, the user can intuitively grasp the received radio wave state from the indicated position of the second hand 53.

  Since the reception state is displayed only during the manual reception process, and the reception state display process is not performed during the automatic reception process, the reception state can be displayed only when necessary for the user. For this reason, the convenience of the user can be improved, and it is not necessary to perform useless radio wave reception state display processing, thereby reducing power consumption.

[Other Embodiments]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

That is, the reception state display method is not limited to the configuration of the above-described embodiment. For example, as shown in FIG. 14, the reception state may be displayed using both the second hand 53 and the calendar display means.
That is, the radio-controlled timepiece 1A shown in FIG. 14 includes a tenth date indicator 55 indicating the tens place of the date and a first date indicator 56 indicating the first place.
Normally, the date is displayed by each date indicator 55, 56. However, when manual reception processing is performed, the tenth date indicator 55 displays the letter “Q” from the date window. The date wheel 56 displays the noise level numerically.
That is, when the count value of the second interval counter 411 is 10 or less and the noise level is high, the tenth date indicator 55 displays the number “3”, and when the count value is 10 to 18 and the noise level is medium, The tenth date indicator 55 displays the number “2”. When the count value is 18 or more and the noise level is low, the tenth date indicator 55 displays the number “1”.

  On the other hand, the radio signal level is displayed using the second hand 53. That is, when the AGC voltage is 0.2 V or less and the radio wave is weak, the second hand 53 is moved to the L position (8 o'clock position), and when the AGC voltage is 0.2 to 0.8 V and the radio wave is in the radio wave, the second hand 53 is moved. When moving to the M position (10 o'clock position) and the AGC voltage is 0.8 V or higher and the radio wave intensity is strong, the second hand 53 is moved to the R position (12 o'clock position).

The tenth date indicator 55 is printed with “Q (Quality)” indicating the noise state in addition to the numbers “0, 1, 2, 3” indicating the date.
Since the first date indicator 56 is originally printed with a number “0-9” indicating the date, the number is used to display the noise level. Since the numbers are printed from “0 to 9”, the noise level may be displayed more finely. For example, five levels of noise levels may be displayed with numbers 1-5.

Further, the reception state may be displayed by the second hand 53 and the small hand 57 as in the radio wave correction timepiece 1B shown in FIG. The small hand 57 normally indicates the day of the week in the right half area of the small window 58. In FIG. 15, seven scales M (Monday) to S (Sunday) are set from the lower side to the upper side of the small window 58.
When the battery remaining amount display mode is set by button operation, the small hand 57 displays the remaining battery amount in the left half area of the small window 58. That is, the scale is such that the remaining battery level increases from 6 o'clock side to 12 o'clock side of the small window 58, and the small hand 57 indicates the current remaining battery level.
Further, in the reception state display mode, the small hand 57 displays the noise level in the left half area of the small window 58. That is, the scale is such that the noise decreases (the reception environment becomes better) from the 6 o'clock side to the 12 o'clock side of the small window 58, and the small hand 57 indicates the current noise level.
According to these radio wave correction watches 1A and 1B, the signal intensity and the noise level can be displayed completely separately.

In the above-described embodiment, the reception status display S7 is performed only once in one manual reception process, except in the case where “No” is determined in S11 and the receiving station is selected again in S3. In other words, the reception status display allows the user to recognize the reception environment at that location, and if the environment is good, continue the reception as it is, and if the environment is bad, stop the reception with a button operation and move to another location Because the reception process is started again by the button operation (S1), the reception status display S7 may be performed once every time the manual reception operation is performed.
On the other hand, the reception status display may be updated at 1-minute intervals even during reception of the time code. In this case, the user can move while searching for a place with good reception. In this case, the count value of the second interval counter 411 may be reset and updated at a cycle of 1 minute.

  In the above embodiment, the analog circuit shown in FIG. 3 is used as the AGC circuit 36, but other circuit configurations may be used. For example, an AGC circuit that detects a waveform after envelope detection with an AD converter and digitally generates an AGC voltage using a DA converter may be used. In this case, the digital signal before the DA converter can be used as the AGC signal output to the control unit 46, and the control unit 46 can control based on this digital data, so that the control by the control unit 46 can be easily performed. .

  Furthermore, in the above-described embodiment, the radio-controlled timepiece 1 has been described as an example of a straight system that does not perform frequency conversion. However, the present invention is not limited thereto, and may be a radio-controlled timepiece having a superheterodyne reception circuit unit, for example. . In such a case, the reception frequency may be switched not by switching the band-pass filter but by switching the transmission frequency or frequency division ratio of a VCO (Voltage Controlled Oscillator).

The reception state display method is not limited to using a member driven by a pointer or a motor such as a date wheel. For example, in the case of a digital watch, the reception state may be displayed on a display unit such as a liquid crystal panel. Good. In this case, detailed reception status display such as a graph display of changes in the AGC voltage value and the count value of the second interval counter 411 is possible.
Furthermore, the symbol displayed on the timepiece when the reception state is displayed with the hands such as the second hand 53 is not limited to the alphabet as in the above-described embodiment, but may be a number, a mark, or other characters. In addition, when using alphabets, the characters are not limited to the characters in the embodiment. For example, although the letter “I” representing “Interfere” or “interference” is used as the letter indicated by the second hand 53 when the reception environment is bad due to noise, “disturb” or “disturbance” is indicated. A character “D” or a character representing “Noise” may be used.

Furthermore, in the above embodiment, the reception state display by the reception state display unit 462 is performed only in the manual reception mode, but it may be performed in the automatic reception mode. The user may be able to set whether or not to display the reception state in the automatic reception mode.
In addition, the specific structure and procedure for carrying out the present invention can be appropriately changed to other structures and the like within a range in which the object of the present invention can be achieved.

  DESCRIPTION OF SYMBOLS 1,1A, 1B ... Radio wave correction clock, 2 ... Antenna, 3 ... Reception circuit part, 4 ... Control circuit part, 5 ... Display part, 6 ... External operation member, 32 ... 1st amplifier circuit, 35 ... Envelope detection circuit , 36 ... AGC circuit, 37 ... binarization circuit, 39 ... decoding circuit, 41 ... TCO decoding unit, 42 ... storage unit, 44 ... time counter, 45 ... drive circuit unit, 46 ... control unit, 53 ... second hand, 55 ... 10th date indicator, 56 ... 1st date indicator, 57 ... small hand, 58 ... small window, 61 ... button, 411 ... second interval counter, 461 ... reception state determination means, 462 ... reception state display means.

Claims (6)

A radio-controlled timepiece that receives a standard radio wave having a time code and corrects the time of the internal clock based on the received standard radio wave,
An amplifier circuit for amplifying the received signal of the standard radio wave;
An auto gain control circuit for adjusting the gain of the amplifier circuit according to the strength of the received signal;
Binarization means for binarizing the received signal based on a predetermined threshold and outputting a binarized signal;
Pulse determining means for determining an error state of the received signal based on the pulse change timing of the binarized signal;
A reception state determination unit that determines a reception state based on a gain adjustment level of the amplification circuit by the auto gain control circuit and a determination result of the pulse determination unit;
Reception status display means for displaying the reception status determined by the reception status determination means;
A radio-controlled timepiece characterized by comprising: The radio-controlled timepiece according to claim 1,
The reception state determination means determines the strength of the reception signal from the gain adjustment level of the amplifier circuit, and determines the noise state from the determination result of the pulse determination means,
The radio wave correction timepiece, wherein the reception status display means separately displays the strength of the reception signal and the noise status. In the radio-controlled timepiece according to claim 1 or 2,
Manual reception mode in which reception is started by operation of an external operation member;
It has an automatic reception mode that starts reception when the internal time reaches a predetermined time,
The radio wave correction timepiece, wherein the reception status display means displays the reception status at least when operating in the manual reception mode. The radio-controlled timepiece according to any one of claims 1 to 3,
The radio wave correction timepiece, wherein the reception status display means displays the reception status using time display means for displaying time. The radio-controlled timepiece according to any one of claims 1 to 4,
When the reception status is displayed by the reception status display means, if a reception stop operation is performed by an external operation member, the reception processing is stopped. A control method for a radio-controlled clock that receives a standard radio wave having a time code and corrects the time of the internal clock based on the received standard radio wave,
An amplifier circuit for amplifying the received signal of the standard radio wave;
An auto gain control circuit for adjusting the gain of the amplifier circuit according to the strength of the received signal;
Binarization means for binarizing the received signal based on a predetermined threshold and outputting a binarized signal; and
Determine the strength of the received signal based on the gain adjustment level of the amplifier circuit by the auto gain control circuit,
Determine the error condition of the received signal based on the pulse change timing of the binarized signal,
A method of controlling a radio-controlled timepiece, comprising: determining and displaying a reception state based on the strength of the reception signal and an error state of the reception signal.

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