JP2009019921A - Radio controlled timepiece and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio controlled timepiece capable of reducing an influence of a reception environment when acquiring time information, and realizing power saving. <P>SOLUTION: The radio controlled timepiece includes a reception means for receiving a standard radio wave; a binarization circuit 37 for binarizing a reception signal of the standard radio wave with a prescribed threshold, and outputting a binary signal; a storage part 42 for storing a reference range value of a duty of a time code set beforehand corresponding to the kind of the time code; a duty determination part 43 for calculating a pulse duty of the binary signal, and determining whether the calculated received pulse duty is included within the reference range value; a control part 46 for outputting a control signal for changing a relative level of the threshold to the reception signal, when determined that the received pulse duty is not within the reference range value; and a TCO decoding part 41 for demodulating the time code by decoding the binary signal, when determined that the received pulse duty is within the reference range value. <P>COPYRIGHT: (C)2009,JPO&INPIT

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.

Conventionally, a radio timepiece capable of receiving a standard radio wave is known (see, for example, Patent Documents 1 and 2).
The standard radio wave is amplitude-modulated, and the radio timepiece is a binary signal obtained by extracting the envelope of the received signal with a filter or the like in the receiving circuit and then comparing the envelope signal with a reference voltage with a comparator (comparator). A binarization circuit is provided. The radio timepiece obtains time information based on the time code signal obtained by the binarization circuit and displays the time.
These radio timepieces also include an AGC circuit (Automatic Gain Control) that automatically controls the gain of the received signal based on the received signal.

JP-A-10-274681 JP 2006-60849 A

However, although the radio timepiece includes an AGC circuit, the binarization level (threshold value) of the binarization circuit is fixed, and there is a possibility that a correct time code cannot be obtained depending on the reception environment.
For this reason, in the radio timepiece, the reception of the standard radio wave is continued for about 3 to 7 minutes, a plurality of time codes are acquired, and each time code is evaluated to determine whether correct time information has been obtained. ing.
However, such a method requires at least several minutes until it can be determined whether correct time information has been obtained. For this reason, for example, it takes time to determine that correct time information cannot be obtained due to deterioration of the reception environment, and there is a problem that power consumption increases accordingly.

  An object of the present invention is to provide a radio-controlled timepiece that can reduce the influence of the reception environment when acquiring time information and can also realize power saving, and a control method therefor.

  The radio-controlled timepiece of the present invention is a radio-controlled timepiece that receives a standard radio wave having a time code and corrects the time based on the received standard radio wave, a receiving means for receiving the standard radio wave, and the standard radio wave The binarization means for binarizing the received signal based on a predetermined threshold and outputting the binarized signal, and the reference range value of the duty of the time code set in advance according to the type of the time code are stored And a duty determination unit that calculates a pulse duty of the binarized signal output from the binarization unit and determines whether the calculated reception pulse duty is included in the reference range value When the duty determination means determines that the received pulse duty is not within the reference range value, the relative level of the threshold with respect to the received signal is changed. Time code decoding means for decoding the binarized signal and demodulating the time code when the level switching means and the duty determination means determine that the received pulse duty is within the reference range value It was characterized by comprising.

  According to this invention, the duty determination means compares the reference range value stored in the storage unit with the received pulse duty of the binarized signal obtained by binarizing the received signal related to the standard radio wave received by the receiving means. To do. The level switching means, for example, performs control to change the amplification factor of the received signal or control to change the threshold value when the received signal is binarized when the received pulse duty is not within the reference range value. Then, the relative level of the threshold with respect to the received signal is changed. As a result, the received pulse duty is included in the reference range value, and the binarization condition in the binarization means is optimized.

The present invention is characterized in that the received radio wave is evaluated based on the duty of the time code based on the new knowledge that the duty of the time code is within a certain range depending on the type of the standard radio wave. .
That is, in the Japanese standard radio wave JJY, as will be described later, the duty of the time code is in the range of about 60 to 70% (reference range value). Therefore, if the radio-controlled timepiece is set to receive JJY, the pulse duty of the received signal should be within the reference range value. Therefore, if it is not within the above-mentioned reference range value, it is possible to grasp the situation that the level of the received signal is reduced due to the influence of the reception environment around the radio-controlled clock, and change the relative level of the threshold for the received signal Can be optimized and the correct time code can be obtained.
Then, such a relative level change of the threshold value can be controlled only by acquiring a time code of one minute, for example, and compared with a conventional control method that cannot be determined unless reception is performed for several minutes. Can be processed. Therefore, the overall reception time can be shortened and power saving can be achieved.
Further, by changing the relative level of the threshold value, even if the reception environment is somewhat deteriorated, it is possible to adjust the threshold level suitable for the received signal, and to acquire a correct time code. Therefore, according to the radio-controlled timepiece of the present invention, the influence of the reception environment can be reduced and the time can be corrected to the correct time.

Note that the duty of the time code means the ratio of the high level portion within the predetermined signal range of the time code. For example, when the duty is calculated using 1-minute data in the time code, the ratio obtained by dividing the high level time by 1 minute (= 60 seconds) in the 1-minute data is the duty.
Moreover, the relative level of the threshold with respect to the received signal means, for example, the relative level of the threshold voltage with respect to the amplitude value (voltage value) of the received signal. That is, the received signal oscillates between a high level and a low level, and the threshold value is arranged between these levels. At this time, for example, a threshold value for the maximum level value of the received signal may be set as a relative level.
Furthermore, the reference range value of the time code is set according to the type of standard radio wave. That is, the standard radio wave constitutes information such as “1”, “0”, “marker”, etc. by the difference in the length of the high level (difference in duty) in the pulse signal per second. The time code is transmitted in combination. For example, in JJY, the duty of a pulse signal of 1 Hz is “P marker” is 20%, “1” is 50%, and “0” is 80%. For this reason, the duty of one time code (one-minute time code) varies depending on time information of each time code, but is about 60 to 70%. Therefore, when receiving JJY, if the received pulse duty is within the reference range value (60 to 70%), it can be determined that the threshold level is optimized and the correct time code is available.

  In the radio-controlled timepiece according to the invention, the duty determination unit determines whether the received pulse duty is not within the reference range value, determines whether the received pulse duty is larger or smaller than the reference range value, The level switching means increases the relative level of the threshold with respect to the received signal when the received pulse duty is larger than the reference range value, and when the received pulse duty is smaller than the reference range value. Preferably, the relative level of the threshold with respect to the received signal is reduced.

When the received pulse duty is larger than the reference range value, the threshold level is smaller than the level of the received signal, so it is predicted that the signal to be determined as the low level is determined as the high level. Conversely, when the received pulse duty is smaller than the reference range value, the threshold level is larger than the level of the received signal, so that it is predicted that the signal that should be determined as the high level is determined as the Low level.
Therefore, when the reception pulse duty is larger than the reference range value, the relative level of the threshold with respect to the reception signal is increased, and when the reception pulse duty is smaller than the reference range value, If the relative level of the threshold with respect to the received signal is reduced, the relative level of the threshold can be appropriately adjusted in a shorter time.

The radio-controlled timepiece according to the present invention further includes a threshold adjustment unit that changes the threshold in the binarization unit, and the level switching unit includes the duty determination unit, and the received pulse duty is within the reference range value. When it is determined that the threshold value is not, the control signal for changing the threshold value in the binarization means is output to the threshold value adjustment means, and the threshold value adjustment means changes the threshold level based on the control signal. It is preferable to change the relative level of the threshold with respect to the received signal.
According to the present invention, since the level switching means changes the threshold level in the binarization means, the threshold level for the received signal can be changed even if the signal amplification factor is fixed, and the correct time Get the code.
For example, when the signal pulse duty is larger than the reference range value, the threshold level is low with respect to the received signal, so that the noise component in the low level portion of the received signal is determined to be equal to or higher than the threshold and determined to be the low level. This means that the power signal portion is determined to be the High level. In this case, by increasing the threshold value, the noise component of the Low level portion becomes less than the threshold level, and a correct time code can be acquired.
On the other hand, when the signal pulse duty is smaller than the reference range value, since the threshold level is high with respect to the received signal, the High level portion is determined to be less than the threshold level, and the signal portion to be determined as the High level is set to Low. It will be judged as a level. In this case, by lowering the threshold value, the High level portion becomes equal to or higher than the threshold level, and a correct time code can be acquired.
When the binarizing means is constituted by a comparator, the threshold level can be changed by switching the level of the reference voltage value input to the comparator, for example. Therefore, the threshold level can be changed by simple control, and the circuit configuration can be set relatively easily.
In addition, the threshold level may be configured to be continuously variable, but normally, it may be configured to be switchable to a plurality of levels (for example, 3 to 4 levels).

The radio-controlled timepiece according to the present invention further includes an amplifying unit that amplifies the received signal of the received standard radio wave, and an amplification adjusting unit that changes an amplification factor of the received signal in the amplifying unit, When the duty determination means determines that the received pulse duty is not within the reference range value, a control signal for changing a signal amplification factor in the amplification means is output to the amplification adjustment means, and the amplification adjustment means Preferably, based on the control signal, the signal amplification factor of the amplifying means is changed to change the relative level of the threshold with respect 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 the correct time code can be obtained. You can get it.
For example, when the signal pulse duty is larger than the reference range value, the noise component in the low level portion is amplified to the threshold level or higher, and the signal portion to be determined as the low level is determined as the high level. . In this case, by reducing the signal amplification factor, the noise component in the Low level becomes less than the threshold level, and a correct time code can be acquired.
On the other hand, when the signal pulse duty is smaller than the reference range value, the high level portion is as small as less than the threshold level, and the signal portion to be determined as the high level is determined as the low level. 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 acquired.
Since the level switching unit changes the signal amplification factor in the amplification unit, for example, when an AGC circuit is provided as the amplification adjustment unit, the AGC characteristic of the AGC circuit is switched to change the amplification factor in the amplification unit. Control is sufficient. Since such an AGC circuit is originally incorporated in a radio-controlled timepiece, when changing the relative level of the threshold value by changing the signal amplification factor, it is not necessary to incorporate a new component at low cost. Can be realized.

Further, the radio-controlled timepiece according to the present invention includes a receiving circuit unit including the receiving unit, the binarizing unit, and the threshold value adjusting unit, the storage unit, the duty determining unit, the time code decoding unit, and the level. A control circuit unit that includes a switching unit, and outputs a control signal output from the level switching unit to the reception circuit unit to control a reception state of the standard radio wave in the reception circuit unit, and the reception circuit The unit preferably includes 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 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. Thereby, since the decoding unit decodes the control signal, the control signal output from the control circuit unit can be set to a simple signal, and the reliability of the signal to be communicated can be improved.

The radio-controlled timepiece according to the present invention includes a reception circuit unit including the reception unit, the amplification unit, the amplification adjustment unit, and the binarization unit, the storage unit, the duty determination unit, and the time code decoding unit. And a control circuit unit that outputs a control signal output from the level switching unit to the receiving circuit unit and controls the reception state of the standard radio wave in the receiving circuit unit. The receiving circuit unit includes 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 control signal to the amplification adjusting unit. preferable.
According to this invention, the decoding unit decodes the input control signal, and the amplification adjustment unit adjusts the signal amplification factor of the amplification unit based on the decoded control signal. Thereby, since the decoding unit decodes the control signal, the control signal output from the control circuit unit can be set to a simple signal, and the reliability of the signal to be communicated can be improved.

The radio-controlled timepiece according to the present invention further includes a serial communication line that connects the receiving circuit unit and the control circuit unit, and the control circuit unit controls the receiving circuit unit via the serial communication line. Preferably, the signal is output by serial communication, and the receiving circuit unit receives the control signal by serial communication via the serial communication line, and decodes it by the control signal decoding means.
According to this invention, the receiving circuit unit and the control circuit unit are connected by the serial communication line. Thereby, the number of communication lines to be connected can be reduced as compared with the case where the receiving circuit unit and the control circuit unit are connected by parallel communication lines, and the circuit configuration of the radio-controlled timepiece can be further simplified. In parallel communication, it is difficult to increase the communication speed due to the need to synchronize data transmission on each signal line. However, in the present invention, the communication speed is increased and the signal is transmitted by serially outputting a control signal. It is possible to suppress mistakes, and for example, it is possible to improve responsiveness and reliability in voltage adjustment by the voltage adjustment unit and signal amplification factor adjustment by the amplification adjustment unit.

Further, in the radio-controlled timepiece according to the invention, the level switching means receives the reception after the start of the reception operation and the duty determination means determines that the reception pulse duty is within the reference range value. It is preferable that the relative level of the threshold with respect to the received signal is not fixed and changed until the operation is finished.
According to this invention, after setting the relative level of the threshold with respect to the received signal to an appropriate level, the level is fixed. Therefore, while the time code is being decoded by the time code decoding means, The level is maintained at a constant value.
Thereby, stable binarization processing can be performed, bit corruption and the like can be prevented, and the time code can be decoded more accurately.

Furthermore, in the radio-controlled timepiece of the present invention, the level switching means stores the relative level of the threshold value with respect to the received signal set during the receiving operation for each type of standard radio wave, and performs the next receiving operation. Sometimes, it is preferable to set a relative level of the threshold with respect to the stored received signal as an initial set value.
In general, the radio-controlled timepiece has a function of receiving automatically at a preset time. At the time of such regular reception, there is a high possibility that the surrounding reception environment is almost constant. Therefore, if the relative level of the threshold with respect to the received signal set at the previous reception is set as an initial value, the received pulse duty is likely to be within the reference range value without switching the level. Therefore, the reception process can be performed in a shorter time and efficiently.

Further, in the radio-controlled timepiece of the present invention, the receiving unit is configured to be able to select and receive a plurality of types of standard radio waves, and includes a received radio wave setting unit that selects the type of standard radio waves received by the receiving unit, The storage unit stores a plurality of reference range values that are set for each type of standard radio wave, and the duty determination unit includes the reference range value corresponding to the type of standard radio wave selected by the received radio wave setting unit. It is preferable to make a determination by comparing the received pulse duty of the binarized signal.
According to the present invention, for example, in a radio-controlled timepiece capable of receiving various types of standard radio waves, for example, JJY (Japan), WWVB (USA), DCF77 (Germany), etc., Since the reference range value can be set according to the type, the optimum level can be set for each standard radio wave, and the correct time code can be acquired.

A method for controlling a radio-controlled timepiece according to the present invention is a method for controlling a radio-controlled timepiece that receives a standard radio wave having a time code and corrects the time based on the received standard radio wave, receiving the standard radio wave, The received signal of the standard radio wave is binarized based on a predetermined threshold value to output a binarized signal, the pulse duty of the binarized signal is calculated, and the reference of the time code duty stored in advance in the storage unit When it is determined whether or not the received pulse duty is not within the reference range, the relative level of the threshold with respect to the received signal is changed, and this level changing process is performed. Repeat until the reception pulse duty is within the reference range, and when it is determined that the reception pulse duty is within the reference range value, decode the binarized signal. Characterized by demodulating the time code.
According to the present invention, as with the radio-controlled timepiece, the overall reception time can be shortened, power can be saved, and even if the reception environment is somewhat deteriorated, the threshold level is adjusted to be suitable for the received signal. The correct time code can be acquired, the influence of the reception environment can be reduced, and the time can be corrected to the correct time.

[First embodiment]
Hereinafter, 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 the radio-controlled timepiece according to the first embodiment.
FIG. 2 is a circuit diagram showing configurations of the binarization circuit and the VREF switching circuit.
FIG. 3 is a diagram showing the received pulse duty and amplitude change for each signal of the standard radio wave “JJY” in Japan.
FIG. 4 is a diagram showing changes in received pulse duty and amplitude for each signal of the standard radio wave “WWVB” in the United States.
FIG. 5 is a diagram showing changes in received pulse duty and amplitude for each signal of the standard radio wave “DCF77” in Germany.
FIG. 6 is a diagram showing changes in received pulse duty and amplitude for each signal of the standard radio wave “MSF” in the United Kingdom.
FIG. 7 is a diagram showing an outline of a radio wave data table stored in the storage unit.
FIG. 8 is a diagram illustrating a method of measuring the pulse duty of the TCO signal in the duty determination unit.
FIG. 9 is a diagram illustrating another example of a method for measuring the pulse duty of the TCO signal in the duty determination unit.

(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 quartz crystal. And a vibrator 47.
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. The control circuit unit 4 controls the display unit 5 to display the time of the time counter 44. Further, the control circuit unit 4 determines the duty of the TCO input from the receiving circuit unit 3 and outputs a control signal to the receiving 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, a 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, etc.), standard radio waves are received. Examples include correction request information for correcting the time.

  The crystal oscillator 47 for the reference clock outputs a predetermined reference signal (reference clock, for example, 1 Hz signal). The reference signal output from the crystal oscillator 47 is input to the control circuit unit 4. Yes.

(2) Configuration of Receiving Circuit Unit 3 As shown in FIG. 1, the receiving circuit unit 3 includes a tuning circuit 31, a first amplifying circuit 32 as an amplifying means, a band-pass filter (hereinafter referred to as “band-pass filter”). BPF ”(sometimes abbreviated as“ BPF ”) 33, second amplifier circuit 34, envelope detection circuit 35, AGC (Auto Gain Control) circuit 36 as amplification adjusting means, and binarization circuit as binarization means 37, a VREF switching circuit 38 as a threshold adjusting means, and a decoding circuit 39 as a control signal decoding means.

  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 this 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 “MSF” in the United Kingdom, etc. It is configured to receive standard radio waves.

  The first amplifier circuit 32 adjusts the gain according to a signal 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. That is, according to the signal input from the AGC circuit 36, the first amplifying circuit 32 reduces the gain when the amplitude is large, and increases the gain when the amplitude is small. Amplify so that

  The 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.
The AGC circuit 36 outputs a signal 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.

  As shown in FIG. 2, the binarization circuit 37 includes a binarization comparator, and one of the two input terminals is connected to the envelope detection circuit 35, and the other input terminal is The VREF switching circuit 38 is connected. Then, the binarization circuit 37 is based on an envelope signal input from the envelope detection circuit 35 and a reference voltage (threshold value) having a predetermined voltage input from the VREF switching circuit 38, that is, a binarization signal, that is, a TCO signal. Is output.

  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 TCO decoding unit 41 of 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 TCO decoding unit 41.

  The VREF switching circuit 38 generates reference voltages VREF1 to VREF4 from the power supply voltage VDD output from the constant voltage source 381 and outputs the reference voltage to the binarization circuit 37. The VREF switching circuit 38 includes a constant voltage source 381, four resistors R1 to R4 arranged between the constant voltage source 381 and the ground GND, and between these four resistors R1 to R4 and the binarization circuit 37. , Four switches SW1 to SW4 disposed between the R4 and the ground GND, and between the binarization circuit 37, and a constant current source 382 disposed between the resistor R4 and the ground GND. ing.

  Among these, each of the switches SW1 to SW4 is configured by an analog switch, the switch SW1 is binarized between the resistors R1 and R2 and the binarization circuit 37, and the switch SW2 is binarized between the resistors R2 and R3. Between the circuit 37, the switch SW3 is between the resistors R3 and R4 and the binarization circuit 37, and the switch SW4 is between the resistor R4 and the constant current source 382 and the binarization circuit 37. Each is arranged. Each of the switches SW1 to SW4 is independently connected to the decode circuit 39 via the selection lines SEL1 to SEL4 so that the on / off state is switched according to a signal input from the decode circuit 39. It is configured. Then, when any one of these switches SW1 to SW4 is turned on (conductive state) and the other switches are turned off (non-conductive state), the power supply voltage VDD output from the constant voltage source 381 is The voltage is changed by the current IS and the resistor R output from the constant current source 382, and the reference voltage VREF is input to the binarization circuit 37.

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

  The decode circuit 39 is connected to the control circuit unit 4 to be described later via a serial communication line SL. The decode circuit 39 decodes the control signal input from the control circuit unit 4 and outputs a signal for setting the on / off state of the switches SW1 to SW4 based on the code included in the control signal to each selection line. Output to SEL1 to SEL4.

(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 controls the decoding circuit 39 of the reception circuit unit 3 with respect to the reference circuit 39. A control signal for switching the voltage VREF is output. 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. Furthermore, 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, a duty determination unit 43 as a duty determination unit, a time counter 44, and a drive circuit unit. 45 and a control unit 46 as level switching means. 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.
Specifically, the TCO decoding unit 41 recognizes the waveform of the TCO signal and measures the reception pulse duty with respect to a predetermined pulse width (for example, 1 Hz). Then, TC is recognized from the TCO signal based on the difference in the received pulse duty. For example, in the standard radio wave (JJY) used in Japan, as shown in FIG. 3, when the pulse width of the high level signal is 0.5 seconds with respect to the pulse width of 1 second (that is, the duty is 50). %)), The signal “1” (1 signal) is recognized. Further, 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 is 80%), the signal “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 is 20%), the “P” signal (P signal) is recognized. Then, the TCO decoding unit 41 recognizes a predetermined TC from the sequence of the recognized 1 signal, 0 signal, and P signal.

  In the above, TC recognition in JJY has been exemplified. However, when the received standard radio wave is of another type, TC is recognized based on the time duty corresponding to each radio wave. For example, as shown in FIGS. 4, 5, and 6, in the standard radio wave (WWVB) in the United States, 1 signal is used when the duty is 50%, 0 signal when the duty is 20%, and the duty is 80%. In some cases, the P signal is recognized. In the standard radio wave (DCF77) in Germany, 1 signal is recognized when the duty is 80%, and 0 signal is recognized when the duty is 90%. In the standard radio wave (MSF) in the UK, the duty is 80%. 1 signal, 0 signal is recognized when the duty is 90%, and P signal is recognized when the duty is 50%.

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. Such a storage unit 42 stores a radio wave data table 8 in which radio wave data 81 relating to standard radio waves received by the receiving circuit unit 3 is recorded, which is set when the radio wave correction timepiece 1 is manufactured.
Here, as shown in FIG. 7, the radio wave data table 8 includes radio wave data 81 configured by associating radio wave type data 82 and reference radio wave data 83 as one record, and a plurality of these radio wave data 81 are stored. Built to record table structure.

The radio wave type data 82 is information related to the type of standard radio wave received by the receiving circuit unit 3, and records, for example, JJY, WWVB, DCF77, MSF, and the like.
In the reference radio wave data 83, a duty ratio of TC (time code) included in the standard radio wave specified by the radio wave type data 82 is recorded. Specifically, the reference radio wave data 83 is a reference range value that is a duty ratio for one TC of the standard radio wave specified by the radio wave type data 82, and the duty of the 0 signal, 1 signal, and P signal that constitute the TC. Information on amplitude change of standard radio waves is recorded. In this embodiment, since the average value of the duty of JJY time code is 66%, the reference range value is set to 60 to 70%. Similarly, since the average values of the time codes of WWVB, DCF77, and MSF are 89%, 67%, and 87%, respectively, the reference range values of these radio waves are 85 to 95% and 61 to 71, respectively. %, 83-92%, etc.
The storage unit 42 stores radio wave type setting data related to the type of standard radio wave received by the receiving circuit unit 3 and other reception setting data in which setting information related to reception is recorded.

The duty determination unit 43 compares the reception pulse duty of the TCO signal input from the reception circuit unit 3 with the reference range value of the standard radio wave duty, and whether the reception pulse duty of the TCO signal is included in the reference range value. Judge whether or not. Specifically, the duty determination unit 43 measures the received pulse duty with respect to the input TCO signal by a method as shown in FIG.
That is, in the measurement method shown in FIG. 8, the input TCO signal is sampled for a predetermined period with, for example, a sampling clock of 64 Hz or 100 Hz generated based on the reference clock, and the signal level of the sampled TCO is high. Or low level. At this time, the TCO decoding unit 41 determines “1” when the sampled TCO signal is at a high level, and determines “0” when the signal is at a low level. Here, for example, when sampling for 30 seconds at 100 Hz, the total number of data is 30 × 100 = 3000, and when “1” is 751 among them, the reception pulse duty is 751/3000 = 25.0%. Become.

The pulse duty may be measured by the measurement method shown in FIG. 9 without being limited to the measurement method shown in FIG.
That is, in the measurement method shown in FIG. 9, the time from when the rising edge U of the TCO signal is detected to when the rising edge U is detected and the timer is driven from the position where the rising edge U is detected until the falling edge D is detected. Measure. The time T from the rising edge U to the falling edge D is repeatedly measured, and reception is performed by calculating the ratio of the total of the time T from the rising edge U to the falling edge D to the total sampling time of the TCO signal. Measure the pulse duty.

The duty determination unit 43 then receives the received pulse duty of the TCO signal measured and calculated by the measurement method as described above, and the reference range value of the duty recorded in the radio wave data table 8 stored in the storage unit 42. To determine whether the reception pulse duty of the TCO signal is within the reference range value. Here, the portion of the TCO signal that transmits data related to the date of the month differs depending on the date on which the standard radio wave is received, and the portion that transmits data relating to the hour differs depending on the time of receiving the standard radio wave. Among these, by setting the time for receiving the standard radio wave to a predetermined time between 2 am and 5 am, for example, the standard radio wave is not easily affected by other radio waves, lighting or other electronic devices, The difference in the duty of the part that transmits the data relating to the hour and minute is minute. On the other hand, as described above, the portion for transmitting the data related to the date of the month differs depending on the date of reception, and therefore it is preferable to set the reference range value in consideration of the duty change of this portion.
Then, when the reception pulse duty of the TCO signal is not within the reference range value, the duty determination unit 43 further determines whether the reception pulse duty of the TCO signal is larger or smaller than the reference range value.

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

  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. To control. 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 controls to move the pointer by the driving force of the stepping motor. .

  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 outputs a predetermined control signal to the reception circuit unit 3 based on the determination in the duty determination unit 43.
Specifically, when the operation signal input from the external operation member 6 includes radio wave type setting data for setting the type of the standard radio wave, the control unit 46, based on the radio wave type setting data. The radio wave reception state setting information in the storage unit 42 is updated. For example, when an operation signal in which radio wave type setting data for setting the type of received standard radio wave to JJY is input by operating the external operation member 6, the control unit 46 displays the reception setting data in the storage unit 42. Record radio wave type setting data for receiving JJY.
When the control unit 46 recognizes that the periodical correction time set in advance, for example, between 2 am and 5 am is counted by the time counter 44, the control unit 46 determines the duty of the radio wave data 81 read from the storage unit 42. Control is performed to output to the unit 43 and to compare and judge the received pulse duty of the TCO signal with the reference range value. At this time, the control unit 46 selects the radio wave data 81 corresponding to the radio wave type setting data stored in the reception setting data of the storage unit 42, and sets the reference range value recorded in the reference radio wave data 83 of the radio wave data 81. It outputs to the duty judgment part 43.

  When the duty determination unit 43 determines that the reception pulse duty of the TCO signal is larger than the reference range value, the control unit 46 increases the reference voltage in the VREF switching circuit 38 by one step in the reception circuit unit 3. A control signal to that effect is output. When the duty determination unit 43 determines that the reception pulse duty of the TCO signal is smaller than the reference range value, the control unit 46 causes the reception circuit unit 3 to lower the reference voltage in the VREF switching circuit 38 by one step. The control signal is output.

Note that the control unit 46 and the decode circuit 39 are connected by the serial communication line SL as described above, and the control signal is input to the decode circuit 39 via the serial communication line SL. As a result, a control signal for controlling the 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 46 and the reception circuit unit 3, a two-line synchronous interface capable of bidirectional communication between the control unit 46 and the reception circuit unit 3 is used to perform bidirectional communication. 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.

(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. 10 is a flowchart showing the time adjustment operation of the radio-controlled timepiece 1.
FIG. 11 shows an original waveform related to TC included in a standard radio wave, a waveform of an envelope signal when the standard radio wave is received in a weak electric field environment, and an envelope signal when the standard radio wave is received in a noise environment. It is a figure which shows a waveform.
FIG. 12 is a diagram illustrating an original waveform relating to TC included in a standard radio wave and a waveform of a TCO signal obtained by binarizing the received signal of the standard radio wave based on each reference voltage after envelope detection.

  When the radio-controlled timepiece 1 is manufactured, the radio wave data table 8 is written and stored in the storage unit 42. Further, when the radio-controlled timepiece 1 is manufactured, for example, JJY is recorded as default data as radio wave type setting data of the reception setting data. 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.

In FIG. 10, the control unit 46 of the radio-controlled timepiece 1 monitors the time counted by the time counter 44, and the time counted by the time counter 44 is preset between 2 am and 5 am When it is recognized that the time has come, the standard radio wave is received by the antenna 2 and control for starting the time adjustment operation is performed (step S101).
In step S101, the standard radio wave received by the antenna 2 is converted into a voltage signal (reception signal) by the tuning circuit 31. Then, the first amplification circuit 32, the band-pass filter 33, the second amplification circuit 34, and the envelope detection circuit 35 amplify the received signal to a predetermined level, extract a signal in a desired frequency band, rectify and filter it. The 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.

After step S101, the control unit 46 of the control circuit unit 4 recognizes the type of the standard radio wave and the reference range value of the standard radio wave (step S102).
Specifically, the control unit 46 recognizes the radio wave type setting data from the reception setting data stored in the storage unit 42. Here, in the initial state, as described above, since JJY is recorded as the radio wave type setting data, the control unit 46 recognizes that the received standard radio wave is JJY. In addition, 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 recognized. The control unit 46 reads the radio wave data 81 having the radio wave type data 82 corresponding to the recognized radio wave type setting data from the radio wave data table 8, and the reference range recorded in the reference radio wave data 83 of the radio wave data 81. Recognize the value. In addition, the control unit 46 outputs the recognized reference range value to the duty determination unit 43.

  Then, when the TCO signal is input from the receiving circuit unit 3 (step S103), the duty determining unit 43 of the control circuit unit 4 receives the TCO signal by the measurement method as shown in FIG. 8 or FIG. Calculate the pulse duty. Further, the duty determination unit 43 recognizes the reference range value recognized in step S102, which is input from the control unit 46. Then, the duty determination unit 43 determines whether the reception pulse duty is within the reference range value (step S104).

  Here, in the reception circuit unit 3, the envelope signal after the envelope detection has a different waveform depending on the reception environment of the standard radio wave as shown in FIG. For example, as shown in FIG. 11 (a), the ambient noise in the reception environment is small, but when the distance from the transmission station is long and the electric field is weak, the standard radio wave is weakened, so the amplitude of the envelope signal is small. The signal level is also reduced. When the reception environment is a noise environment, the standard radio wave reception signal is affected by noise, and the amplitude and signal level also increase. Therefore, when the envelope signal is binarized by the binarization circuit 37, a binarized signal (TCO signal) having a different waveform is output due to a difference in the reference voltage.

  In step S104, the duty determination unit 43 calculates the reception pulse duty for such a TCO signal, and determines whether this reception pulse duty is within the reference range value.

For example, as shown in FIG. 12, a standard radio wave (JJY) including a TCO signal as shown in A1 is received, and envelope detection is performed by the receiving circuit unit 3 described above and shown in A2 of FIG. Assume that a waveform-like signal is obtained.
Here, when the reference voltage is switched to a high setting (for example, VREF1) in the VREF switching circuit 38, a TCO signal having a waveform as indicated by A3 is output from the receiving circuit unit 3 to the control circuit unit 4. In this case, the duty determination unit 43 compares the reference range value (60 to 70%) of the JJY duty input from the control unit 46 with the calculated reception pulse duty (54%) of the TCO signal. It is determined that the received pulse duty of the signal is smaller than the reference range value.
When the reference voltage is switched to a low setting (for example, VREF3) in the VREF switching circuit 38, a TCO signal having a waveform as indicated by A5 is output from the receiving circuit unit 3 to the control circuit unit 4. In this case, the duty determination unit 43 compares the JJY duty reference range value (60 to 70%) input from the control unit 46 with the calculated reception pulse duty (75%) of the TCO signal, and calculates the TCO. It is determined that the received pulse duty of the signal is larger than the reference range value.
Further, when the reference voltage is switched to an intermediate setting (for example, VREF2) in the VREF switching circuit 38, a TCO signal having a waveform as indicated by A4 is output from the receiving circuit unit 3 to the control circuit unit 4. In this case, the duty determination unit 43 compares the JJY duty reference range value (60 to 70%) input from the control unit 46 with the calculated reception pulse duty (67%) of the TCO signal, and calculates the TCO. It is determined that the received pulse duty of the signal is within the reference range value.

When the duty determination unit 43 determines that the received pulse duty is outside the reference range value, the control unit 46 determines whether or not the reference voltage can be switched by the VREF switching circuit 38 (step S105). ), When the switching is possible, a control signal for switching the reference voltage is output to the receiving circuit unit 3.
For example, when a TCO signal as shown in A3 of FIG. 12 is obtained, it is determined that the reception pulse duty of the TCO signal is smaller than the reference range value, so that the control unit 46 increases the reception pulse duty. , A control signal for lowering the reference voltage in the VREF switching circuit 38 by one step (set to VREF2) is output.
Further, when a TCO signal as shown in A5 of FIG. 12 is obtained, it is determined that the reception pulse duty of the TCO signal is larger than the reference range value, so that the control unit 46 reduces the reception pulse duty. Then, a control signal for increasing the reference voltage in the VREF switching circuit 38 by one level (set to VREF2) is output.
In this way, by switching the reference voltage, for example, when the reception environment as shown in FIG. 11A is a weak electric field, the standard radio wave is weakened as described above, so the amplitude of the envelope signal is small, Although the signal level is also reduced, the TCO can be accurately obtained by lowering the reference voltage so that the binarization level is lowered. Further, when the reception environment as shown in FIG. 11B is a noise environment, the received signal of the standard radio wave is affected by noise, and the amplitude and the signal level are increased, but the binarization level is increased. Thus, by raising the reference voltage, the TCO can be obtained accurately.
When receiving the control signal as described above, the receiving circuit unit 3 decodes the control signal by the decoding circuit 39 and outputs the decoded control signal to the VREF switching circuit 38. The VREF switching circuit 38 switches the reference voltage based on the control signal. As a result, the reference voltage in the binarization circuit 37 changes, and the corrected TCO signal is output to the control circuit unit 4 again.
On the other hand, if it is determined in step S105 that the reference voltage cannot be switched, for example, the current reference voltage setting is VREF4, which is the lowest voltage setting, and the reception pulse duty of the TCO signal is within the reference range. If it is determined that the value is smaller than the value, the reception of the standard radio wave is terminated and the time adjustment operation is terminated (step S107).

  In step S104, for example, as shown by A4 in FIG. 12, when the duty determination unit 43 determines that the received pulse duty is within the reference range value, the control unit 46 determines that the currently received TCO signal is , A second synchronization process is performed (step S108). That is, the standard radio wave is a radio wave that transmits one TC every minute, and the 0 signal, the 1 signal, and the P signal as described above are transmitted every second. Therefore, each signal can be recognized by detecting the rise of the standard radio wave signal every second and performing the second synchronization processing.

Thereafter, the control unit 46 controls the TCO decoding unit 41 to decode the TCO signal and acquire the TC (step S109). The standard radio wave is sequentially input to the antenna 2 and the standard radio wave is received by the receiving circuit unit 3, but the control unit 46 maintains the set voltage of the VREF switching circuit 38 during the TC decoding process in step S 109. In addition, the reference voltage (threshold value) in the binarization circuit 37 is not changed during decoding.
And the control part 46 judges whether exact TC was acquired by step S109 (step S110), and when accurate TC is acquired, the reception operation | movement of the standard wave in the receiving circuit part 3 is complete | finished (step S110). Step S111). Thereafter, the control unit 46 outputs the acquired TC to the time counter 44, corrects each counter value of the time counter 44, and corrects the display time of the display unit 5 (step S112).
On the other hand, when the accurate TC cannot be acquired because the received pulse duty is different in step S110, the processing of step S107, that is, the reception operation of the standard radio wave in the receiving circuit unit 3 is terminated, and the time correction operation is performed. Terminate.

(5) Effects of the radio-controlled timepiece 1 in the first embodiment As described above, in the radio-controlled timepiece 1 as described above, the duty determination unit 43 has the reference range value stored in advance in the storage unit 42. And the received pulse duty of the TCO signal. When the duty determination unit 43 determines that the reception pulse duty of the TCO signal is outside the reference range value, the control unit 46 switches the reference voltage of the binarization circuit 37 to the reception circuit unit 3. Output a control signal.
For this reason, it is possible to optimize so that the reception pulse duty of the TCO signal output from the binarization circuit 37 is within the reference range value. Therefore, an accurate TC can be obtained by decoding the TCO signal having the reception pulse duty within such a reference range value by the TCO decoding unit 41, and the radio wave correction timepiece 1 can be obtained by the decoded TC. The time correction process can be accurately performed.

Whether the received pulse duty is within the reference range value can be determined by receiving a time code of 1 minute at the maximum. For this reason, it is possible to make a determination in a shorter time than a conventional method in which it is not possible to determine whether or not a correct time code is received unless a plurality of time codes are acquired by receiving radio waves for several minutes. Therefore, the average reception time in the radio-controlled timepiece can be shortened, and power can be saved.
Furthermore, since the reference voltage in the binarization circuit 37 can be changed, even if the reception environment is somewhat deteriorated, it can be adjusted to a threshold level suitable for the received signal, and a correct time code can be acquired. Therefore, the influence of the reception environment such as the noise environment and the strength of the received radio wave can be reduced, and the time can be corrected to the correct time.

The control unit 46 maintains the reference voltage set by the VREF switching circuit 38 while the TCO decoding unit 41 decodes the TCO signal into TC, and the reference voltage in the binarization circuit 37 is not changed. .
For this reason, since the reference voltage does not change during decoding, it is possible to avoid inconveniences such as obstructing accurate decoding due to, for example, garbled bits, and to decode accurate TC.

Further, the receiving circuit unit 3 includes a decoding circuit 39, which 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.
For this reason, since the decoding circuit 39 decodes the control signal, the control signal output from the control circuit unit 4 can be set to a simple signal, and the reliability of the signal to be communicated can be improved.

Further, the radio wave data table 8 records a plurality of radio wave data 81 corresponding to a plurality of types of standard radio waves. When the radio wave type setting data for setting the type of the standard radio wave is input by operating the external operation member 6, the control unit 46 receives the radio wave type data 82 corresponding to the standard radio wave type of the radio wave type setting data. Is recognized. The duty determination unit 43 compares the reference range value recorded in the radio wave data 81 with the reception pulse duty of the TCO signal, and the control unit 46 sends a control signal to the reception circuit unit 3 according to the comparison result. Output.
Therefore, the radio-controlled timepiece 1 can extract an optimum TCO signal from each standard radio wave reception signal corresponding to a plurality of standard radio wave types. Therefore, for example, even when moving to a place where a different standard radio wave is transmitted, the time can be easily and accurately corrected only by operating the external operation member 6 and setting the type of the standard radio wave.

  The receiving circuit unit 3 and the control circuit unit 4 are connected by a serial communication line. For this reason, compared with the case where the receiving circuit part 3 and the control circuit part 4 are connected by a parallel communication circuit, the number of communication lines can be reduced and the circuit configuration in the radio-controlled timepiece 1 can be further simplified. In addition, the communication speed can be further increased by serially outputting a control signal from the control circuit unit 4 to the receiving circuit unit 3 via the serial communication line. Furthermore, the control circuit unit 4 and the reception circuit unit 3 are connected by a pair of serial communication lines so that bidirectional communication can be performed, so that a control signal is output from the control unit 46 to the reception circuit unit 3. The receiving circuit unit 3 can transfer the received and recognized control signal to the control unit 46 again, and can confirm the data difference between the control signal output by the control unit 46 and the input control signal. With such a configuration, more reliable serial communication can be performed.

In the radio-controlled timepiece 1, the standard radio wave is received at a preset time between 2 am and 5 am, and the time is adjusted.
In other words, from 2:00 am to 5:00 am, good standard radio waves that are less affected by electromagnetic waves generated from electronic devices, etc., and noise caused by communication radio waves from other communication devices, and that have little signal waveform disturbance, etc. Can be received.

[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 the radio-controlled timepiece according to the second embodiment.
FIG. 14 is a diagram illustrating the relationship between the AGC voltage and the gain in the first amplifier circuit.
FIG. 15 is a diagram illustrating 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 the description of the radio-controlled timepiece 1A of the second embodiment, the same components as those of the radio-controlled timepiece 1 of the first embodiment described above are denoted by the same reference numerals, and the description thereof is simplified or omitted. To do.

(1) Configuration of the radio-controlled timepiece 1A In FIG. 13, a radio-controlled timepiece 1A includes an antenna 2, a receiving circuit unit 3A that receives a standard radio wave input to the antenna 2, and a control circuit unit that controls the receiving circuit unit 3A. 4A, a display unit 5 for displaying the time counted by the time counter 44 of the control circuit unit 4A, an external operation member 6 for inputting the operation of the radio-controlled timepiece 1A, and a crystal resonator 47. .
The control unit 46 of the first embodiment described above changes the reference voltage in the binarization circuit 37 when the duty determination unit 43 determines that the received pulse duty of the TCO signal is different from the reference range value. In the control unit 46A of the radio-controlled timepiece 1A, when the duty determination unit 43 determines that the received pulse duty of the TCO signal is different from the reference range value, the control unit 46A A control signal for changing the signal amplification factor of the one amplifier circuit 32A is output.

(2) Configuration of Reception Circuit Unit 3A The reception circuit unit 3A includes a tuning circuit 31, a first amplification circuit 32A, a BPF 33, a second amplification circuit 34, an envelope detection circuit 35, as shown in FIG. , An AGC circuit 36A, a binarization circuit 37, and a decoding circuit 39 are provided. The tuning circuit 31, the BPF 33, the second amplifier circuit 34, and the envelope detection circuit 35 have the same configuration as in the first embodiment, and a description thereof is omitted.

Similar to the first amplifier circuit 32 in the radio-controlled timepiece 1 of the first embodiment, the first amplifier circuit 32A adjusts the gain by switching the AGC voltage according to the signal input from the AGC circuit 36A and tunes it. The reception signal input from the circuit 31 is amplified and input to the BPF 33.
Here, the relationship between the AGC voltage and the gain in the first amplifier circuit 32A is as shown in FIG. That is, when the AGC voltage is set to 0.0 to 0.2 V, the gain in the first amplifier circuit 32A is 80 dB. When the AGC voltage is set to 0.2 V or more, the gain is substantially proportional to the AGC voltage. If the AGC voltage is set to 1.0 V, the gain becomes about 0.0 dB. The AGC voltage input to the first amplifier circuit 32A is set to a variable width of about 0.1 to 0.9V.

The AGC circuit 36A outputs an AGC voltage corresponding to the AGC characteristic set based on the control signal input from the decode circuit 39 to the first amplifier circuit 32A.
Specifically, as shown in FIG. 15, the AGC circuit 36A selects one AGC characteristic from AGC1 to AGC4 based on the control signal, and sets the AGC voltage corresponding to the selected AGC characteristic to the first amplifier circuit. Output to 32A.
For example, when the AGC characteristic of the AGC 1 is selected, the AGC circuit 36A, when the input level of the received signal input to the first amplifier circuit 32A is about 50 dB, applies an AGC voltage of 0.4V to the first amplifier circuit 32A. Output to. When the input level of the received signal increases, for example, approximately 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 outputs the AGC voltage corresponding to the input level of the received signal input to the first amplifier circuit 32A, so that the amplitude of the received signal is maintained at a constant value corresponding to the AGC characteristic. To control.
In the second embodiment, as shown in FIG. 15, the AGC voltage can be switched to any one of AGC1, AGC2, AGC3, and AGC4, but five or more AGCs are illustrated. A configuration may be adopted in which any one of the voltages is selected and output to the first amplifier circuit 32A. In addition, the AGC voltage output to the first amplifier circuit 32A may be configured to be continuously variable, but the power supply voltage used in the electronic circuit of the watch is as low as 1.4V, so the dynamic range of the AGC voltage is narrow, As described above, a configuration in which the AGC characteristic is switched is preferable.

Similar to the first embodiment, the decode circuit 39 is connected to a control circuit unit 4A described later via a serial communication line SL. The decode circuit 39 decodes the control signal input from the control circuit unit 4A, and outputs a signal for setting the AGC voltage in the AGC circuit 36A based on the code included in the control signal.
(3) Configuration of 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 according to the first embodiment. That is, as shown in FIG. 13, the control circuit unit 4A includes a TCO decoding unit 41, a storage unit 42, a duty determination unit 43, a time counter 44, a drive circuit unit 45, and a control unit 46A. Configured.

  The control unit 46A in the control circuit unit 4A of the radio-controlled timepiece 1A according to the second embodiment is driven based on the drive frequency input from the crystal unit 47 and performs various control processes. That is, similarly to the control unit 46 of the first embodiment, the control unit 46A outputs the TC input from the TCO decoding unit 41 to the time counter 44 and performs control to correct the count of the time counter 44. . The control unit 46 </ b> A 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 46A outputs a predetermined control signal to the reception circuit unit 3A based on the determination in the duty determination unit 43. Specifically, when the duty determination unit 43 determines that the reception pulse duty of the TCO signal is greater than the reference range value, the control unit 46A sets the AGC circuit A set in the reception circuit unit 3A by the AGC circuit 36A. A control signal for switching the characteristic to the AGC characteristic in which the one-step gain is set small is output. When the duty determination unit 43 determines that the reception pulse duty of the TCO signal is smaller than the reference range value, the control unit 46A displays the AGC characteristic set by the AGC circuit 36A in the reception circuit unit 3A. A control signal for switching to the AGC characteristic having a large one-step gain is output.

(4) Operation of Radio Correction Clock 1A Next, the time correction operation using the standard radio wave in the radio correction clock 1A as 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 related to TC included in the standard radio wave, the waveform of the envelope signal after envelope detection of the received signal output based on the setting of each AGC voltage characteristic, and these envelope signals. It is a figure which shows the waveform of the binarized TCO signal.

  In FIG. 16, the radio-controlled timepiece 1 </ b> A performs a time correction operation substantially similar to the above-described radio-controlled timepiece 1. In other words, the radio-controlled timepiece 1A performs the same processing as steps S101 to S104 in the time-correcting operation of the radio-controlled timepiece 1. The description of the operation from step S101 to step S103 is omitted here, and the description of the operation of step S104 is simplified.

In step S104, in the control circuit unit 4A of the radio-controlled timepiece 1A, the duty determination unit 43 compares the received pulse duty of the TCO signal confirmed in step S103 with the reference range value recognized in step S102. It is determined whether the received pulse duty is within a reference range value.
For example, as shown in FIG. 17, when a standard radio wave (JJY) including a TCO signal as shown in A1 is received and an AGC voltage corresponding to the AGC characteristic of AGC1 is output from the AGC circuit 36A, an envelope is generated. The envelope signal after the line detection has a waveform as shown by A6 in FIG. 17, and the TCO signal when the envelope signal A6 is binarized by the binarization circuit 37 is as shown by A7 in FIG. Waveform.
In this case, the duty determination unit 43 compares the reference range value (60 to 70%) of the duty of JJY input from the control unit 46A with the pulse duty (54%) of the TCO signal, and receives the received pulse of the TCO signal. It is determined that the duty is smaller than the reference range value.
When an AGC voltage corresponding to the AGC characteristic of AGC2 is output from the AGC circuit 36A, an envelope signal having a waveform as shown in A8 of FIG. 17 is obtained, and a TCO signal as shown in A9 is output. The In this case, the duty determination unit 43 compares the reference range value (60 to 70%) of the JJY duty input from the control unit 46A with the calculated reception pulse duty (67%) of the TCO signal. It is determined that the received pulse duty of the signal is within the reference range value.

  In step S104, when the duty determination unit 43 determines that the received pulse duty is outside the reference range value, the control unit 46A determines whether or not the AGC characteristic can be switched in the AGC circuit 36A. However, if switching is possible, a control signal for switching the AGC characteristic is output to the receiving circuit unit 3A.

For example, when a TCO signal as indicated by A7 in FIG. 17 is obtained, it is determined that the reception pulse duty of the TCO signal is smaller than the reference range value. In this case, since the control unit 46A needs to increase the gain of the first amplifier circuit 32A (decrease the AGC voltage) in order to increase the reception pulse duty, the AGC characteristic in the AGC circuit 36A is determined by a one-step gain. A control signal for switching to a larger setting (setting to AGC2) is output.
Although not shown, when it is determined that the reception pulse duty of the TCO signal is larger than the reference range value, the control unit 46A reduces the gain of the first amplifier circuit 32A in order to reduce the reception pulse duty. (AGC voltage must be increased). In this case, a control signal for switching the AGC characteristic in the AGC circuit 36A to a setting in which the one-step gain is reduced is output.

  Then, when the control signal as described above is input, the receiving circuit unit 3A decodes the control signal by the decode circuit 39 and outputs it to the AGC circuit 36A (step S202). The AGC circuit 36A switches AGC characteristics based on the control signal. As a result, the AGC voltage output to the first amplifier circuit 32A changes, and the signal amplification factor also changes. Therefore, when this received signal is envelope-detected and output as an envelope signal, the amplitude of the envelope signal changes compared to the original waveform, thereby changing the waveform of the TCO signal.

  On the other hand, if it is determined in step S201 that the AGC voltage cannot be switched, for example, the current AGC characteristic is set to AGC1 in FIG. 15, and the reception pulse duty of the TCO signal is the reference range value. If it is determined that it is greater than the value, the process of step S107, that is, reception of the standard radio wave is terminated, and the time adjustment operation is terminated.

In step S104, for example, as shown by A9 in FIG. 17, when the duty determination unit 43 determines that the difference between the received pulse duty and the reference range value is within a predetermined threshold, The same processing as step S108 to step S112 in the radio wave correction timepiece 1 of the embodiment is performed.
That is, in step S108, the control unit 46A performs second synchronization processing based on the currently received TCO signal, and in step S109, the TCO decoding unit 41 decodes TC from the TCO signal. At this time, similarly to the radio-controlled timepiece 1 of the first embodiment, the control unit 46A maintains the setting of the AGC characteristic of the AGC circuit 36A during the decoding process of the TC in step S109, and the AGC characteristic during the decoding is determined. Will not be changed.
In step S110, the control unit 46A determines whether or not an accurate TC is acquired in step S109. When the accurate TC is acquired, the process of step S111, that is, the standard radio wave in the reception circuit unit 3A is obtained. The receiving operation is terminated. Thereafter, the control unit 46A performs control to output the acquired TC to the time counter 44, correct each counter value of the time counter 44, and display the time on the display unit 5.
On the other hand, if the accurate TC cannot be acquired because the received pulse duty is different in step S110, the processing of step S107, that is, the reception operation of the standard radio wave in the reception circuit unit 3A is terminated, and the time adjustment operation is performed. Terminate.

(5) Effects of the radio-controlled timepiece 1A according to the second embodiment As described above, in the radio-controlled timepiece 1A according to the second embodiment, the duty determination unit 43 is stored in the storage unit 42 in advance. The reference range value is compared with the received pulse duty of the TCO signal. When the duty determination unit 43 determines that the difference between the reference range value and the reception pulse duty of the TCO signal is greater than a predetermined threshold, the control unit 46A causes the reception circuit unit 3A to perform the first amplification. A control signal for switching the AGC characteristic in the circuit 32A is output.
Therefore, the TCO signal can be optimized so that the signal amplification factor in the first amplifier circuit 32A changes and the reception pulse duty of the TCO signal output from the binarization circuit 37 is within the reference range value. . Therefore, similarly to the radio-controlled timepiece 1 of the first embodiment, an accurate TC can be acquired based on this TCO signal, and the time correction process of the radio-controlled timepiece 1A is accurately performed using this TC. be able to.

[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, in the first and second embodiments, the example in which the duty determination unit 43 is incorporated in the control circuit units 4 and 4A has been described. However, the present invention is not limited to this, and for example, a radio wave correction watch as shown in FIG. 1B may be sufficient.

That is, in FIG. 18, the radio-controlled timepiece 1B is provided with a duty determination unit 301 in the reception circuit unit 3B. In such a radio-controlled timepiece 1B, the TCO signal output from the binarization circuit 37 is input to the duty determination unit 301 provided in the reception circuit unit 3B. The control unit 46B of the control circuit unit 4B recognizes the radio wave data 81 stored in the storage unit 42, and outputs a control signal including a reference range value (target value in FIG. 18) to the reception circuit unit 3B.
When receiving a control signal from the control circuit unit 4B, the receiving circuit unit 3B decodes the control signal by the decoding circuit 39 and outputs the decoded control signal to the duty determining unit 301.

  And the duty judgment part 301 performs the process similar to the duty judgment part 43 of said 1st and 2nd embodiment, ie, from the reference | standard range value contained in the control signal, and the binarization circuit 37 The received pulse duty of the input TCO signal is compared to determine whether the received pulse duty is within the reference range value. When the duty determination unit 301 determines that the received pulse duty is within the reference range value, a TCO signal is output from the binarization circuit 37 to the control circuit unit 4B, and the TCO decoding unit of the control circuit unit 4B. At 41, the TC is decoded. On the other hand, when the duty determination unit 301 determines that the received pulse duty is outside the reference range value, the duty determination unit 301 outputs a signal to the AGC circuit 36A to change the AGC characteristic setting, and the AGC circuit 36A Change the AGC characteristic setting. Note that the duty determination unit 301 may output a signal for switching the reference voltage in the binarization circuit 37 to the VREF switching circuit 38 as in the radio-controlled timepiece 1 of the first embodiment.

  Even in the above configuration, as in the first and second embodiments, the reference range value is compared with the reception pulse duty of the TCO signal, and the TCO is set so that the reception pulse duty is within the reference range value. The signal can be optimized, and an accurate TC can be obtained by decoding such a TCO signal. In addition, since the duty determination unit 301 is provided in the hardware of the reception circuit unit 3B, the control circuit unit 4B does not need to perform special control, and the control circuit unit 4B has the same configuration as the software of a normal radio-controlled clock. Since it can comprise, versatility can be improved.

In each of the above embodiments, the reference voltage VREF of the binarization circuit 37 at the time of the reception process and the initial value of the AGC characteristic in the AGC circuit 36A may be a fixed value set in advance, for example, set at the time of the previous reception process The stored value may be stored, and the previous set value may be set as the initial value in the next reception process.
In this case, in the reception process in which the surrounding reception environment is constant as in the case of regular reception, if the value set at the previous reception is set as the initial value, the reference voltage and the AGC characteristic are not switched. There is a high possibility that the received pulse duty can be controlled to be within the reference range value. Therefore, the reception process can be performed in a shorter time and efficiently.

  Further, in each of the above embodiments, the reception time for receiving the standard radio wave is not defined, but for example, calendar data is included at a predetermined scheduled reception time set in advance between 2 am and 5 am It is good also as a structure which receives the standard radio wave of the part which is not. That is, at the same time, the hour / minute data is a fixed value regardless of the date. For example, in the case of JJY, the standard radio wave transmitted from 55 seconds to 21 seconds per minute does not include calendar data but includes only hour / minute data. Therefore, when the time is adjusted every day when receiving the same scheduled time, by setting to receive the standard radio wave from 55 seconds to 21 seconds, the calendar data is not included and 27 bits consisting only of hour and minute data The TCO signal can be obtained. Therefore, the pulse duty of the TCO signal does not need to take into account fluctuations in pulse duty due to differences in calendar data, so the range of the reference range value to be compared with the TCO signal can be made narrower and more accurate. The pulse duty of the TCO signal can be compared and determined.

  Further, in the above embodiment, the radio correction watches 1, 1A, 1B have been shown as examples of the straight system that does not perform frequency conversion, but are not limited to this, for example, radio correction that has a superheterodyne reception circuit unit. It is good also as a clock. In such a case, the reception frequency may be switched not by switching the bandpass filter but by switching the transmission frequency or the frequency division ratio of a VCO (Voltage Controlled Oscillator).

  Furthermore, in the first embodiment, the reference voltage is switched in the binarization circuit 37 by switching the reference voltage by the VREF switching circuit 38. However, the present invention is not limited to this. For example, a circuit for fixing the reference voltage and changing the offset value of the comparator may be provided, and a threshold value may be changed by providing a plurality of inverters that change the capabilities of the Pch transistor and the Nch transistor.

  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.

It is a block diagram which shows the structure of the electromagnetic wave correction timepiece which concerns on 1st embodiment. It is a circuit diagram which shows the structure of the binarization circuit and VREF switching circuit of said 1st Embodiment. It is a figure which shows the receiving pulse duty and amplitude change with respect to each signal of the standard radio wave "JJY" in Japan. It is a figure which shows the receiving pulse duty and amplitude change with respect to each signal of standard radio wave "WWVB" in the United States of America. It is a figure which shows the received pulse duty and amplitude change with respect to each signal of the standard radio wave "DCF77" in Germany. It is a figure which shows the receiving pulse duty and amplitude change with respect to each signal of the standard radio wave "MSF" in the United Kingdom. It is a figure which shows the outline of the electromagnetic wave data table memorize | stored in a memory | storage part. It is a figure which shows the measuring method of the pulse duty of the TCO signal in a duty judgment part. It is a figure which shows the other example of the measuring method of the pulse duty of the TCO signal in a duty judgment part. It is a flowchart which shows the time correction operation | movement of a radio wave correction clock. The figure which shows the original waveform concerning TC contained in a standard radio wave, the waveform of the envelope signal when this standard radio wave is received in a weak electric field environment, and the waveform of the envelope signal when the standard radio wave is received in a noise environment It is. It is a figure which shows the waveform of the TCO signal which binarized based on each reference 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 block diagram which shows the structure of the electromagnetic wave correction timepiece which concerns on 2nd embodiment. It is a figure which shows the relationship between the AGC voltage and gain in a 1st amplifier circuit. It is a figure which shows the relationship of the AGC voltage with respect to the input level of a received signal in each AGC characteristic switched by an AGC circuit. It is a flowchart which shows the time correction operation | movement of a radio wave correction clock. The original waveform related to TC included in the standard radio wave, the waveform of the envelope signal after envelope detection of the received signal output based on the setting of each AGC voltage characteristic, and these envelope signals are binarized It is a figure which shows the waveform of a TCO signal. It is a block diagram which shows the structure of the radio wave correction timepiece which concerns on the modification of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,1A, 1B ... Radio wave correction clock, 2 ... Antenna, 3, 3A, 3B ... Reception circuit part, 4, 4A, 4B ... Control circuit part, 8 ... Radio wave data table, 32, 32A ... First amplification circuit, 36 , 36A ... AGC circuit, 37 ... binarization circuit, 38 ... VREF switching circuit, 39 ... decoding circuit, 41 ... TCO decoding unit, 42 ... storage unit, 43, 301 ... duty judgment unit, 46, 46A, 46B ... control 81: Radio wave data, 82: Radio wave type data, 83: Reference radio wave data.

Claims (11)

A radio-controlled timepiece that receives a standard radio wave having a time code and corrects the time based on the received standard radio wave,
Receiving means for receiving the standard radio wave;
Binarization means for binarizing the received signal of the standard radio wave based on a predetermined threshold and outputting a binarized signal;
A storage unit for storing a reference range value of a duty of a time code set in advance according to the type of the time code;
Duty determining means for calculating a pulse duty of the binarized signal output from the binarizing means and determining whether or not the calculated received pulse duty is included in the reference range value;
Level switching means for changing a relative level of the threshold with respect to the received signal when the duty determining means determines that the received pulse duty is not within the reference range value;
Time code decoding means for decoding the binarized signal and demodulating the time code when the duty determining means determines that the received pulse duty is within the reference range value;
A radio-controlled timepiece characterized by comprising: The radio-controlled timepiece according to claim 1,
The duty determination means determines whether the received pulse duty is greater than or less than the reference range value when it is determined that the received pulse duty is not within the reference range value;
When the received pulse duty is larger than the reference range value, the level switching means increases the relative level of the threshold with respect to the received signal, and the received pulse duty is smaller than the reference range value. The radio-controlled timepiece is characterized in that a relative level of the threshold with respect to the received signal is reduced. In the radio-controlled timepiece according to claim 1 or 2,
Threshold adjustment means for changing the threshold in the binarization means,
The level switching means sends a control signal for changing the threshold value in the binarization means to the threshold adjustment means when the duty determination means determines that the received pulse duty is not within the reference range value. Output,
The radio-controlled timepiece, wherein the threshold adjustment means changes the relative level of the threshold with respect to the received signal by changing the level of the threshold based on the control signal. In the radio-controlled timepiece according to claim 1 or 2,
Amplifying means for amplifying the received signal of the received standard radio wave;
Amplifying adjustment means for changing the amplification factor of the received signal in the amplification means,
The level switching means outputs, to the amplification adjusting means, a control signal for changing the signal amplification factor in the amplifying means when the duty judging means determines that the received pulse duty is not within the reference range value. And
The radio-controlled timepiece, wherein the amplification adjusting unit changes a relative level of the threshold with respect to a received signal by changing a signal amplification factor of the amplification unit based on the control signal. The radio-controlled timepiece according to claim 3,
A receiving circuit unit comprising the receiving unit, the binarizing unit, and the threshold adjustment unit;
The storage unit, the duty determination unit, the time code decoding unit, and the level switching unit, the control signal output from the level switching unit is output to the reception circuit unit, and the standard radio wave in the reception circuit unit A control circuit unit for controlling the reception state of
The receiving circuit unit is
A radio-controlled timepiece comprising: 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 control signal to the threshold adjustment unit. The radio-controlled timepiece according to claim 4,
A receiving circuit section comprising the receiving means, the amplifying means, the amplification adjusting means, and the binarizing means;
The storage unit, the duty determination unit, the time code decoding unit, and the level switching unit, the control signal output from the level switching unit is output to the reception circuit unit, and the standard radio wave in the reception circuit unit A control circuit unit for controlling the reception state of
The receiving circuit unit is
A radio-controlled timepiece comprising: control signal decoding means for decoding the control signal output from the level switching means of the control circuit section and outputting the decoded control signal to the amplification adjusting means. The radio-controlled timepiece according to claim 5 or 6,
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 serial communication via the serial communication line,
The radio wave correction timepiece, wherein the receiving circuit unit receives the control signal by serial communication via the serial communication line and decodes the control signal by the control signal decoding means. The radio-controlled timepiece according to any one of claims 1 to 7,
The level switching means starts the reception operation, and after the duty determination means determines that the reception pulse duty is within the reference range value, the level switching means performs the reception signal to the reception signal until the reception operation ends. A radio-controlled timepiece, characterized in that the relative level of the threshold is fixed and not changed. The radio-controlled timepiece according to any one of claims 1 to 8,
The level switching means stores, for each type of standard radio wave, the relative level of the threshold with respect to the reception signal set during the reception operation,
In the next reception operation, a relative level of the threshold with respect to the stored reception signal is set as an initial set value. The radio-controlled timepiece according to any one of claims 1 to 9,
The receiving means is configured to select and receive a plurality of types of standard radio waves,
Receiving radio wave setting means for selecting the type of standard radio wave received by the receiving means;
The storage unit stores a plurality of the reference range values set for each type of standard radio wave,
The duty determination means compares the reference range value corresponding to the type of the standard radio wave selected by the reception radio wave setting means and the reception pulse duty of the binarized signal to make a determination. Correction clock. A control method for a radio-controlled clock that receives a standard radio wave having a time code and corrects the time based on the received standard radio wave,
Receiving the standard radio wave,
Binarizing the received signal of the standard radio wave based on a predetermined threshold and outputting a binarized signal;
Calculating the pulse duty of the binarized signal, determining whether it is included in the reference range value of the duty of the time code stored in advance in the storage unit;
When it is determined that the received pulse duty is not within the reference range value, the relative level of the threshold with respect to the received signal is changed, and this level change process is performed so that the received pulse duty is within the reference range value. Repeat until
A control method comprising: decoding the binarized signal and demodulating the time code when it is determined that the reception pulse duty is within the reference range value.

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