JP2007051939A - Radio-controlled timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio-controlled timepiece, capable of reducing adverse effects of radio reception as much as possible and prevent capacitors, which constitute a tuning circuit capable of receiving a plurality of radio waves, from degrading when the capacitance values of the capacitors have changed due to changes with the passage of time. <P>SOLUTION: The tuning circuit 1 includes an antenna 11, a first capacitor 12 capable of parallel connection to the antenna 11, and a second capacitor 14 capable of parallel connection to the antenna 11. The first capacitor 12 is connected to the antenna 11 in parallel by the turning-on of a switch 13 at the reception of radio waves of a first frequency modulated by a time code. The second capacitor 14 is connected to the antenna 11 in parallel by the turn-on of a switch 15 at the reception of radio waves of a second frequency modulated by a time code. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radio timepiece capable of receiving a radio wave of a predetermined frequency modulated by a time code and displaying a time, and more particularly to a radio timepiece capable of receiving radio waves of a plurality of frequencies.

Conventionally, a radio timepiece described in Patent Document 1 is known as a radio timepiece capable of receiving radio waves of a plurality of frequencies.
This radio timepiece includes a tuning circuit connected in parallel to an antenna. The tuning circuit includes a first capacitor connected in parallel to the antenna, a second capacitor for selective connection connected in parallel to the antenna, a switch for connecting the second capacitor in parallel to the antenna, It has.

In the radio timepiece having such a configuration, only the first capacitor connected in parallel to the antenna is used when receiving radio waves of the first frequency. When receiving radio waves of the second frequency, in addition to using the first capacitor, the switch is turned on and the second capacitor is also used.
Thus, in the conventional radio-controlled timepiece, the first frequency radio wave is received using only the first capacitor connected in advance to the antenna, and the second frequency radio wave is received by combining the first and second capacitors. Like to do. For this reason, for example, when the capacitance value of the first capacitor changes due to secular change or the like, not only the first frequency radio wave cannot be received well, but also the second frequency radio wave cannot be received well. Conceivable.

In the conventional radio timepiece, the antenna and the first capacitor are connected in parallel, and a parallel resonance circuit is always formed. For this reason, the resonant circuit is always in a state of resonance with the radio wave of the first frequency and operates continuously without suspending its operation, so that the deterioration of the antenna and the first capacitor is accelerated. It is done.
Japanese Patent No. 3572034

  In view of the above points, the object of the present invention is to reduce as much as possible the adverse effects of radio wave reception when the capacitance value of a capacitor constituting a tuning circuit capable of receiving a plurality of radio waves changes due to aging, etc. An object of the present invention is to provide a radio clock capable of preventing the deterioration of the capacitor.

In order to solve the above problems and achieve the object of the present invention, each invention has the following configuration.
That is, the first invention includes an antenna, a tuning circuit that selects a radio wave of a predetermined frequency from radio waves received by the antenna, and outputs an electrical signal corresponding to the selection, and an electrical circuit output from the tuning circuit. A radio wave receiving circuit that extracts and outputs a time code representing a time from a signal, wherein the tuning circuit includes the antenna and a first capacitor that can be connected in parallel with the antenna; A second capacitor that can be connected in parallel with the antenna, and one of the first capacitor and the second capacitor is selectively connected in parallel to the antenna. .

In a second aspect based on the first aspect, the first capacitor is connected in parallel to the antenna when receiving a radio wave having a first frequency modulated with a time code, and the second capacitor is modulated with a time code. When receiving the radio wave of the second frequency, the antenna is connected in parallel.
A third invention includes an antenna, a tuning circuit that selects a radio wave of a predetermined frequency from radio waves received by the antenna, and outputs an electrical signal corresponding to the selection, and an electrical signal output from the tuning circuit A radio timepiece including at least a radio wave receiving circuit that extracts and outputs a time code representing time, wherein the tuning circuit includes the antenna, a first capacitor that can be connected in parallel with the antenna, and the antenna A second capacitor that can be connected in parallel with the antenna, and a third capacitor that can be connected in parallel with the antenna and compensates for a reduced capacitance value due to deterioration of the first capacitor or the second capacitor, etc. And the first capacitor is connected in parallel to the antenna when receiving the radio wave of the first frequency modulated by the time code, Two capacitors are connected in parallel to the antenna when receiving radio waves of the second frequency modulated by the time code, and the third capacitor is required when receiving radio waves of the first frequency or the second frequency. The antenna is connected in parallel to the antenna.

  According to the present invention having such a configuration, when the capacitance value of the capacitor constituting the tuning circuit capable of receiving a plurality of radio waves changes due to aging, etc., the adverse effects of radio wave reception due to it can be reduced as much as possible. The deterioration of the capacitor can be prevented.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
The configuration of the first embodiment of the radio timepiece of the present invention will be described with reference to the block diagram of FIG.
As shown in FIG. 1, the radio timepiece according to the first embodiment includes a tuning circuit 1, a radio wave receiving circuit 2, a control processing unit 3, a time measuring circuit 4, and a display 5.

The tuning circuit 1 includes a coiled antenna 11, selects a radio wave having a predetermined frequency from radio waves received by the antenna 11, and outputs an electric signal corresponding to the selection. Operates according to the instructions.
As shown in FIG. 1, the tuning circuit 1 includes an antenna 11, a first series circuit in which a first capacitor 12 and a first switch 13 are connected in series, a second capacitor 14 and a second switch 15 in series. And a connected second series circuit. The antenna 11, its first series circuit, and its second series circuit are connected in parallel.

Further, as described later, the first switch 13 and the second switch 15 of the tuning circuit 1 are each controlled to be turned on and off by the control processing unit 3 when receiving radio waves of a predetermined frequency. Here, the switches 13 and 15 are composed of electronic switches such as transistors.
The radio wave receiving circuit 2 is a circuit that extracts and outputs a time code representing a time from the electrical signal output from the tuning circuit 1.

Although not shown, the radio wave receiving circuit 2 is composed of a high-frequency amplifier circuit, a detection circuit, a comparator, and the like. The electric signal output from the tuning circuit 1 is amplified and detected, and then binarized by the comparator. A time code is generated and output.
The control processing unit 3 is composed of a microprocessor and the like, and controls each unit according to a predetermined procedure and performs various arithmetic processes.

The timer circuit 4 counts signals from a crystal oscillator (not shown) to generate current time data (year, month, day, hour, minute, second data). The current time data generated by the time measuring circuit 4 is corrected using the standard time data reproduced by the control processing unit 3 based on the time code received by the radio wave receiving circuit 2.
The display 5 displays time data generated by the time measuring circuit 4 and is composed of a liquid crystal display.

Next, a first operation example of the first embodiment having such a configuration will be described with reference to FIG.
In the first operation example, a case will be described in which a radio wave having a first frequency (for example, 40 kHz) modulated by a time code and a radio wave having a second frequency (for example, 60 kHz) modulated by a time code are received.

First, when receiving the radio wave of the first frequency, the control processing unit 3 turns on only the first switch 13 of the tuning circuit 1. As a result, in the tuning circuit 1, only the first capacitor 12 is connected in parallel to the antenna 11, and it is possible to receive a radio wave of the first frequency. When the radio signal can be received, an electric signal corresponding to the first frequency is received. Is output.
The radio wave receiving circuit 2 extracts a time code from the electrical signal output from the tuning circuit 1, and the extracted time code is output to the control processing unit 3. The control processing unit 3 reproduces the standard time data based on the time code.

The time data generated by the timer circuit 4 is corrected by the control processing unit 3 using the reproduced standard time data. The corrected time data is displayed on the display 5.
Next, when receiving radio waves of the second frequency, the control processing unit 3 turns on only the second switch 15 of the tuning circuit 1. As a result, in the tuning circuit 1, only the second capacitor 14 is connected in parallel to the antenna 11, and it is possible to receive radio waves of the second frequency. When the radio signal can be received, an electric signal corresponding to the second frequency is received. Is output.

In this case, the subsequent processing of the electric signal output from the tuning circuit 1 is the same as in the above case, and thus the description thereof is omitted.
Here, in the first embodiment, since the tuning circuit 1 has the switches 13 and 15 connected in series to the capacitors 12 and 14, respectively, in addition to the two radio waves having different frequencies as described above, the frequencies are different. Three radio waves can be received.

In this case, according to each frequency of the received radio wave, the control processing unit 3 performs on / off control of the first and second switches 13 and 15 as follows, for example.
That is, when receiving radio waves of the first frequency, only the first switch 13 is turned on, and the antenna 11 and the first capacitor 12 are connected in parallel. When receiving radio waves of the second frequency, only the second switch 15 is turned on, and the antenna 11 and the second capacitor 14 are connected in parallel. Further, when receiving radio waves of the third frequency, both the first switch 13 and the second switch 15 are turned on, and the antenna 11, the first capacitor 12, and the second capacitor 14 are connected in parallel.

As described above, in the first embodiment, radio waves of the first frequency are received by connecting only the first capacitor 12 to the antenna 11 in parallel, and radio waves of the second frequency are connected by connecting only the second capacitor 14 to the antenna 11 in parallel. The radio wave of each frequency was received separately using an individual capacitor.
For this reason, for example, even if a situation occurs in which the capacitance value of one of the first capacitor 12 and the second capacitor 14 changes due to secular change or the like, and radio waves of one frequency cannot be received satisfactorily, This situation does not adversely affect the good reception of radio waves of the other frequency.

  In the first embodiment, the resonance circuit 1 is in an operating state when the first capacitor 12 or the second capacitor 14 is connected in parallel to the antenna 1 for the first time when receiving a radio wave to form a resonance circuit necessary for receiving the radio wave. In other cases, the resonance circuit is not formed, and a rest state is established. For this reason, it is thought that deterioration of an antenna and a capacitor can be prevented, and it is possible to extend their life.

Furthermore, in the first embodiment, it is possible to receive three radio waves having different frequencies as described above. When receiving the three radio waves, the use area can be expanded.
(Second Embodiment)
The configuration of the second embodiment of the radio timepiece of the invention will be described with reference to the block diagram of FIG.

As shown in FIG. 2, the radio timepiece according to the second embodiment includes a tuning circuit 1a, a radio wave receiving circuit 2, a control processing unit 3a, a timing circuit 4, and a display 5.
In the second embodiment, the tuning circuit 1 and the control processing unit 3 of the first embodiment shown in FIG. 1 are replaced with a tuning circuit 1a and a control processing unit 3a shown in FIG. Since the structure of the other part of this 2nd Embodiment is the same as that of the structure of 1st Embodiment, the same code | symbol is attached | subjected to the same component and the description is abbreviate | omitted.

  The tuning circuit 1a is based on the configuration of the tuning circuit 1 shown in FIG. 1, and compensates for the capacitance value ΔC reduced due to deterioration of the first capacitor 12 or the second capacitor 14 in the components of the tuning circuit 11. For this purpose, a third capacitor 16 and a third switch 17 connected in series are added, and this series circuit is connected to the antenna 11 in parallel. Accordingly, the capacitance value C3 of the third capacitor 16 is considerably smaller than the capacitance values C1 and C2 of the first or second capacitors 12 and 14.

  More specifically, as shown in FIG. 2, the tuning circuit 1a includes an antenna 11, a first series circuit in which a first capacitor 12 and a first switch 13 are connected in series, a second capacitor 14 and a second switch. 15 and a third series circuit in which a third capacitor 16 and a third switch 17 are connected in series. The antenna 11, the first series circuit, the second series circuit, and the third series circuit are connected in parallel.

The basic operation of the control processing unit 3a is the same as that of the control processing unit 3 shown in FIG. 1, but when receiving radio waves, the first switch 13, the second switch 15, and the third switch of the tuning circuit 1a. The switches 17 are different from each other in the on / off control as described later.
Next, an operation example of the second embodiment having such a configuration will be described with reference to FIG.

In this operation example, a case will be described in which a radio wave having a first frequency (for example, 40 kHz) modulated by a time code and a radio wave having a second frequency (for example, 60 kHz) modulated by a time code are received.
First, when receiving radio waves of the first frequency, the control processing unit 3a turns on only the first switch 13 of the tuning circuit 1a. As a result, in the tuning circuit 1a, only the first capacitor 12 is connected in parallel to the antenna 11, and it is possible to receive a radio wave of the first frequency. When the radio signal can be received, an electric signal corresponding to the first frequency is received. Is output.

From the electrical signal output from the tuning circuit 1a, the radio wave receiving circuit 2 extracts a time code, and the extracted time code is output to the control processing unit 3a. The control processing unit 3a reproduces the standard time data based on the time code.
The time data generated by the time measuring circuit 4 is corrected by the control processing unit 3a using the reproduced standard time data. The corrected time data is displayed on the display 5.

Next, when receiving radio waves of the second frequency, the control processing unit 3a turns on only the second switch 15 of the tuning circuit 1a. As a result, in the tuning circuit 1a, only the second capacitor 14 is connected in parallel to the antenna 11, and it is possible to receive radio waves of the second frequency. When the radio signal can be received, an electrical signal corresponding to the second frequency is generated. Is output.
In this case, the subsequent processing of the electrical signal output from the tuning circuit 1a is the same as in the above case, and thus the description thereof is omitted.

  By the way, as described above, when receiving radio waves of the first or second frequency, normally, the radio waves can be satisfactorily received. However, for example, the capacitance value of the first capacitor 12 or the second capacitor 14 is reduced due to deterioration or the like, and the capacitance value is insufficient with the first capacitor 12 or the second capacitor 14 alone, and the radio wave is generated. There are cases where reception is not good. Such a determination process is performed by the control processing unit 3a based on the received radio wave at that time.

In this case, the control processing unit 3a performs the following control.
That is, when it is determined that the radio wave of the first frequency is received and the radio wave is received using only the first capacitor 12 but is not satisfactorily received, the switch 17 is further turned on. A capacitor 17 is connected to the antenna 11 in parallel. As a result, the decrease in the capacitance value of the first capacitor 12 can be compensated by the third capacitor 17, so that when this compensation is effective, the radio wave of the first frequency can be received satisfactorily.

  On the other hand, when trying to receive the radio wave of the second frequency and trying to receive the radio wave using only the second capacitor 14 but not receiving it well, the switch 17 is turned on. A capacitor 17 is connected to the antenna 11 in parallel. As a result, the decrease in the capacitance value of the second capacitor 14 can be compensated by the third capacitor 17, so that when this compensation is effective, radio waves of the second frequency can be received well.

In the second embodiment, similarly to the first embodiment, the control processing unit 3a controls the switches 12 and 14 so that three radio waves having different frequencies can be received.
As described above, according to the second embodiment, the same effect as that of the first embodiment can be realized.

Furthermore, in the second embodiment, the third capacitor 16 for compensating for the decreased capacitance value due to the deterioration of the first capacitor 12 or the second capacitor 14 is provided, thereby compensating for it. did.
Therefore, according to the second embodiment, it is possible to receive radio waves satisfactorily even when the capacitance value decreases due to deterioration of the first capacitor 12 or the second capacitor 14. .

It is a block diagram which shows the structure of 1st Embodiment of this invention. It is a block diagram which shows the structure of 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1a ... Tuning circuit, 2 ... Radio wave receiving circuit, 3, 3a ... Control processing part, 4 ... Timing circuit, 5 ... Display, 11 ... Antenna, 12, 14 , 16 ... capacitor, 13, 15, 17 ... switch

Claims (3)

A tuning circuit that includes an antenna, selects a radio wave of a predetermined frequency from radio waves received by the antenna, and outputs an electric signal corresponding to the selection; and a time code that represents time from the electric signal output from the tuning circuit A radio timepiece comprising at least a radio wave receiving circuit for extraction and output,
The tuning circuit includes the antenna, a first capacitor that can be connected in parallel with the antenna, and a second capacitor that can be connected in parallel with the antenna.
One of the first capacitor and the second capacitor is selectively connected in parallel to the antenna.   The first capacitor is connected in parallel to the antenna when receiving a radio wave of a first frequency modulated by a time code, and the second capacitor is received when receiving a radio wave of a second frequency modulated by a time code. The radio timepiece according to claim 1, wherein the radio timepiece is connected in parallel to the antenna. A tuning circuit that includes an antenna, selects a radio wave of a predetermined frequency from radio waves received by the antenna, and outputs an electric signal corresponding to the selection; and a time code that represents time from the electric signal output from the tuning circuit A radio timepiece comprising at least a radio wave receiving circuit for extraction and output,
The tuning circuit includes the antenna, a first capacitor that can be connected in parallel with the antenna, a second capacitor that can be connected in parallel with the antenna, and a parallel connection with the antenna. A third capacitor for compensating for a reduced capacitance value due to degradation of the second capacitor, etc.
The first capacitor is connected in parallel to the antenna when receiving a radio wave having a first frequency modulated by a time code, and the second capacitor receives a radio wave having a second frequency modulated by a time code. The third capacitor is connected in parallel to the antenna as necessary when receiving the radio wave of the first frequency or the second frequency. Radio clock.

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