JP5263017B2 - Radio wave receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio wave reception device which can perform reception processing with excellent reception sensitivity even when metal or the like comes close to an antenna and a tuning setting is deviated, and start the reception processing in a short time when the tuning setting is not deviated. <P>SOLUTION: The radio wave reception device includes search control means (7, 8c) which can search for the setting of a tuning circuit part (A), wherein oscillation signals are generated in parts of an antenna (D) and the tuning circuit part (A), and the oscillation signals are extracted by a reception circuit part (C) while changing over the setting of the tuning circuit part (A). The tuning circuit part (A) is adjusted by default setting information stored in a first storage means (8d) to perform reception and, when the reception level is low, the tuning circuit part (A) is adjusted using setting information previously stored in a second storage means (9a) by performing search by the search control means (7, 8c) in actual use, and reception is performed. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a radio wave receiving apparatus including an antenna and tuning means.

  There have been proposed communication apparatuses that change the frequency characteristics of a tuning circuit connected to an antenna and tune the resonance frequency of the antenna to the frequency of a desired wave (for example, Patent Documents 1 and 2).

JP 11-31958 A Japanese Patent Laid-Open No. 2000-231609

  The present inventors generate an oscillation signal having a frequency substantially equal to the resonance frequency of the antenna by applying positive feedback to the antenna and the tuning circuit, and use this oscillation signal to adjust the antenna. We are developing a receiver.

  According to the antenna adjustment processing of this method, when the resonance frequency of the antenna becomes substantially equal to the frequency of the desired wave by adjusting the tuning circuit, that is, when the frequency of the oscillation signal becomes equal to the frequency of the desired wave. The oscillation signal passes through the narrow band filter of the reception circuit and is detected as an increase in the level of the reception signal. Therefore, by switching the tuning circuit setting while monitoring the reception signal level and searching for a setting state in which the reception signal level increases, it is possible to obtain the tuning circuit setting that matches the frequency of the desired wave. . With this method, antenna adjustment processing can be performed without supplying a signal having the same frequency as the desired wave from the outside.

  In the antenna adjustment processing of the above method, since the level of the received signal must be detected while switching the setting of the tuning circuit at a fine adjustment interval, the time required for the processing becomes relatively long. Therefore, if the antenna adjustment process is performed every time the reception process is performed, there is a problem that the time of the entire reception process becomes long.

  On the other hand, instead of performing antenna adjustment processing for each reception process, the tuning circuit adjustment point is obtained in advance so that good reception sensitivity can be obtained, and the tuning point obtained in advance is tuned during the reception process. It is also conceivable that the circuit setting is switched to shift to reception processing. However, if the setting of the tuning circuit can only be switched to a predetermined adjustment point, depending on the usage condition of the radio wave receiving device, when a conductor such as metal approaches the antenna or the tuning circuit, the resonance frequency of the antenna There arises a problem that a good reception sensitivity cannot be obtained by deviating relatively from the frequency of the desired wave.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a radio wave receiving apparatus that can cope with a deviation in tuning setting according to a use situation and can start reception processing in a short time when there is no deviation in tuning setting. .

In order to achieve the above object, the invention according to claim 1
An antenna for receiving radio waves,
Tuning means capable of switching the frequency characteristics of the antenna;
Oscillating means capable of oscillating a circuit portion of the antenna and the tuning means;
A reception processing means for performing signal processing by extracting a signal of a desired wave from the reception signals received from the antenna;
Search control means for generating an oscillation signal in the circuit portion by the oscillation means and searching for the setting of the tuning means in which the oscillation signal is extracted by the reception processing means while switching the setting of the tuning means;
First storage means for storing default setting information of the tuning means;
Second storage means for storing setting information of the tuning means obtained by the search control means during actual use of the device;
It is a radio wave receiving apparatus characterized by comprising.

The invention described in claim 2 is the radio wave receiver according to claim 1,
When the radio wave reception is performed and the predetermined reception level cannot be obtained, the search control unit is operated, and the setting of the tuning unit is detected when the search control unit detects the setting of the tuning unit that increases the reception level. And receiving control means for storing the setting information of the tuning means in the second storage means.

The invention described in claim 3 is the radio wave receiver according to claim 2,
The reception control means includes
When the tuning means is set to the setting indicated by the setting information of the first storage means and a predetermined reception level cannot be obtained, the tuning means is switched to the setting indicated by the setting information of the second storage means. When a predetermined reception level cannot be obtained even after switching, the search control unit is operated to search for the setting of the tuning unit that increases the reception level.

The invention according to claim 4 is the radio wave receiving apparatus according to claim 1,
The first storage means is a nonvolatile storage means;
The second storage means is a volatile storage means.

The invention described in claim 5 is the radio wave receiver according to claim 1,
The reception processing means is configured to be able to perform signal processing on the reception signals of a plurality of reception channels,
The tuning means has an adjustment range capable of tuning the resonance frequency of the antenna to the frequency of the plurality of reception channels, respectively.
The first storage means and the second storage means have storage areas for storing a plurality of setting information corresponding to the plurality of reception channels, respectively.

The invention described in claim 6 is the radio wave receiver according to claim 2,
A plurality of setting information corresponding to a plurality of reception channels is stored in the first storage unit and the second storage unit,
The reception control means causes a search for the setting of the tuning means corresponding to one reception channel to be received when radio reception is performed and a predetermined reception level cannot be obtained, and increases the reception level. When the setting of the tuning means to be detected is detected, the setting information of the tuning means is stored in the second storage means in association with the one reception channel.

  According to the present invention, when there is no tuning deviation, radio wave reception can be performed promptly and with high sensitivity using the default setting information of the tuning means in the first storage means. In addition, when a tuning deviation occurs during actual use, radio wave reception can be performed with high sensitivity by finding a good setting of the tuning means by the search control means. Furthermore, the good setting of the tuning means at this time can be stored in the second storage means, and thereafter, radio wave reception can be performed using this.

It is a block diagram showing the whole radio timepiece carrying a radio wave receiver of an embodiment of the present invention. It is a block diagram which shows the detail of the electromagnetic wave receiver of FIG. It is the chart which showed an example of the content of the tuning capacity | capacitance setting corresponding | compatible data memorize | stored in EEPROM or RAM. FIG. 5 is a characteristic diagram for explaining a difference between a default tuning capacity setting and a tuning capacity setting during actual use. It is the flowchart which showed the control procedure of the reception mode process performed by CPU. It is a flowchart which shows the process sequence of the tuning mode process performed by step J10 of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the entirety of a radio timepiece equipped with a radio wave receiver according to an embodiment of the present invention, and FIG. 2 is a block diagram showing details of the radio wave receiver 20.

  The radio timepiece according to this embodiment is, for example, a wristwatch or a table clock, and is equipped with the radio wave receiver of the embodiment of the present invention. The radio wave receiver receives domestic and international standard radio waves, and uses the time code signal. The time is automatically adjusted.

  As shown in FIG. 1, this radio timepiece includes a radio wave receiving unit 20 as a reception processing unit that receives standard radio waves, an ADC (analog / digital converter) 6 that AD converts the detection output of the radio wave receiving unit 20, and A CPU (Central Processing Unit) 7 that performs radio wave reception control and clock operation control, an EEPROM (Electrically Erasable and Programmable Read Only Memory) 8 that stores control programs and control data, and a working memory space for the CPU 7 A RAM (Random Access Memory) 9 for storing control data and temporary control data, an input unit 10 having operation buttons and an operation panel for inputting information and commands from the outside, and a display for displaying information such as time to the outside A unit 11, an oscillation circuit 12 for measuring time, and a timing circuit unit 13 are provided. Among these, the radio wave receiver 20, ADC 6, CPU 7, EEPROM 8, and RAM 9 constitute the radio wave receiver of the embodiment of the present invention.

  The radio wave receiving unit 20 forms a feedback loop in the circuit part of the antenna D that receives the radio wave, the tuning circuit unit (tuning means) A that adjusts the frequency characteristics of the antenna D, and the antenna D and the tuning circuit unit A. A feedback circuit section B serving as an oscillating means for performing oscillation, a receiving circuit section C for performing predetermined signal processing on the received signal, and the like.

  The antenna D is a bar antenna in which a winding is provided on a ferrite core, for example. In addition, various types such as a monopole antenna and a dipole antenna can be applied as long as they are not limited to reception of standard radio waves.

  As shown in FIG. 2, the tuning circuit unit A switches the tuning capacitance coupled to the antenna D to change the resonance frequency of the antenna D (resonance in which the inductance component of the antenna D and the capacitance of the tuning circuit unit A are coupled). This is a circuit for changing the resonance frequency of the circuit and tuning it to the frequency of the desired wave, and is provided between the antenna D and the RF circuit 1. The tuning circuit section A is composed of n + 1 capacitors Cc, C1 to Cn and n switches S1 to Sn connected in series to the capacitors C1 to Cn, respectively, and any one of the switches S1 to Sn is selective. By turning on, the corresponding one of the capacitors C1 to Cn is connected in parallel with the coil of the antenna D, and the value of the tuning capacitance coupled to the antenna D is changed.

  The capacitors C1 to Cn are weighted to the capacitance values, and are set so that each capacitance value increases to a power of approximately 2, for example, from the minimum capacitance C1 to the maximum capacitance Cn. With such a configuration, by switching the switches S1 to Sn, the total capacitance value coupled to the antenna D can be switched continuously and in multiple steps in fine steps.

  As shown in FIG. 2, the reception circuit unit C includes an RF circuit 1 that amplifies the reception signal and removes noise from the reception signal, and a BPF (band filter) that extracts only a signal in a desired frequency band from the reception signal. ) 2, an amplifier 3 that amplifies the signal that has passed through the BPF 2, and a detection circuit 4 that detects the received signal.

  The feedback circuit unit B is for causing the signal transmitted from the tuning circuit unit A through the RF circuit 1 to return to the signal path including the tuning circuit unit A, thereby causing the tuning circuit unit A to oscillate in a loop. As shown in FIG. 2, the circuit includes a switch Sw, a non-inverting amplifier 5 that switches between an operating state and a non-operating state by switching the switch Sw, a coupling capacitor Cf, and the like. When the switch Sw is turned on, the signal amplified by the RF circuit 1 is amplified by the non-inverting amplifier 5 and returned to the tuning circuit unit A, so that the antenna D and the tuning circuit unit A are connected to each other in the circuit portion of the antenna D. An oscillation signal having a frequency substantially equal to the resonance frequency can be generated.

  The configuration of the feedback circuit unit B can be variously changed. For example, the feedback destination of the signal via the feedback circuit unit B may be configured such that the signal is fed back to the signal line wound around the antenna D in addition to the signal line of the tuning circuit unit A, for example. Alternatively, the output of the RF circuit 1 may be converted into a differential signal and fed back to the pair of signal lines of the antenna D and the tuning circuit unit A, respectively. Further, an auxiliary winding electromagnetically coupled to the coil of the antenna D is provided, and a signal is fed back to the auxiliary winding, or a radiation antenna is provided to feed back a signal to the antenna D as a radio wave signal. Also good. Further, it is possible to feed back the output of the RF circuit 1 directly to the signal line of the antenna D or the tuning circuit unit A via the feedback signal line without amplifying the signal by the feedback circuit unit B. is there. In this case, it is possible to control the feedback operation on / off by providing a switch element in series with the feedback signal line and turning on / off the switch element.

  The CPU 7 executes the control program of the EEPROM 8 to perform time display control processing, standard radio wave reception control processing, and tuning capacity search processing for obtaining an optimum setting state of the tuning circuit unit A. To do.

  Specifically, the CPU 7 sends a tuning capacitance setting signal to the tuning circuit unit A, switches the switches S1 to Sn, and controls the combination of the capacitors C1 to Cn connected to the signal lines, thereby coupling to the antenna D. It is possible to switch the total value of the tuning capacity to be performed. Further, by sending an on / off switching signal to the switch Sw of the feedback circuit unit B, the feedback circuit unit B can be operated, or the feedback circuit unit B can be disconnected from the tuning circuit unit A and the receiving circuit unit C. It is possible. Further, the CPU 7 specifies the reception channel of the standard radio wave transmitted in the use area based on the setting information of the use area and the time difference information (home time setting) from the world standard time, or sends a switching signal to the BPF 2. Thus, the frequency of the pass band can be switched to the frequency of the corresponding reception channel. Further, it is configured to be able to read time data from the time circuit unit 13 and write time data when the time is corrected, and to input an instruction or information from the outside via the input unit 10 or display it on the display unit 11. It is possible to output a signal and display the time and the like.

  In addition, during the radio wave reception process, the CPU 7 inputs the output of the radio wave receiver 20 as digital time data (time code signal) by the ADC 6 and reads the time data to acquire time information. . Further, the CPU 7 converts the output of the radio wave receiving unit 20 into digital data by the ADC 6 and inputs it in the tuning capacity search process for finding a good setting of the tuning circuit unit A, and sets the detection output level of the radio wave receiving unit 20. It comes to monitor.

  The EEPROM 8 is a non-volatile memory in which data can be electrically written. The EEPROM 8 includes a time display program 8a for displaying time as time passes as a control program executed by the CPU 7. A time correction program 8b for receiving a standard radio wave and correcting the time based on the time code, a tuning capacity search program 8c for searching for an optimum setting of the tuning circuit unit A, and the like are stored. The CPU 7 that executes the time correction program 8b described above constitutes reception control means, and the CPU 7 that executes the tuning capacity search program 8c constitutes search control means.

  Further, the EEPROM 8 has a default tuning capacity setting correspondence table 8d as a first storage unit in which default setting values for each reception channel for which the tuning circuit unit A is optimally set are registered as control data. Although omitted, the setting of the tuning circuit unit A is switched by the home time-reception channel correspondence table in which information indicating the correspondence between the home time setting information and the standard radio wave reception channel (frequency) is registered, and the tuning capacity search program. Stored is a search range table in which information indicating correspondence between a range (referred to as a search range) and a reception channel is registered.

  In this embodiment, since the data content of the default tuning capacity setting correspondence table 8d is obtained and stored for each radio-controlled timepiece after assembly of the product, this data is stored after assembly of the product using the EEPROM 8. The contents are written, but when the data contents of the default tuning capacity setting correspondence table 8d do not vary from product to product, the data contents are determined collectively for the same type of radio clock, and instead of the EEPROM 8 Alternatively, ROM may be used to store the product before assembly. Also, the control program and control data that are the same between products may be stored in the ROM, and only the default tuning capacity setting correspondence table 8d and control data that differs for each product may be stored in the EEPROM 8.

  The RAM 9 is a volatile memory and provides a working memory space for the CPU 7 and stores control data registered and updated during actual use of the apparatus. This control data includes a temporary storage tuning capacity setting correspondence table 9a as second storage means in which the optimum setting value of the tuning circuit section A is registered for each reception channel. In addition, time information indicating the timing for executing the time correction program, home time setting information input from the outside, and the like are also included. The temporary storage tuning capacity setting correspondence table 9a may be stored in the EEPROM 8 as long as data can be written from the CPU 7 to the EEPROM 8 during the actual operation of the radio timepiece.

  FIG. 3 is a chart showing an example of the contents of the default tuning capacity setting correspondence table 8 d stored in the EEPROM 8 in advance and the temporary storage tuning capacity setting correspondence table 9 a stored in the RAM 9.

  In the tuning capacity setting correspondence tables 8d and 9a of this embodiment, the setting values of the tuning circuit unit A are registered in correspondence with a plurality of reception channels (40 kHz, 60 kHz, 77.5 kHz). In FIG. 3, the values in the column of the item “default value” indicate the setting values registered in the default tuning capacity setting correspondence table 8d, and three setting values are registered corresponding to the three reception channels. . Further, the value in the column of the item “temporary storage value” indicates the setting value registered in the temporary storage tuning capacity setting correspondence table 9a, and three setting values are registered corresponding to the three reception channels.

  Although not particularly limited, in this embodiment, the state values of the plurality of switches S1 to Sn of the tuning circuit section A are represented as “1” if they are on, and “0” if they are off, and these state values are arranged in the order of switches S1 → Sn. A binary value of a plurality of bits (for example, 8 bits) is defined as a set value that determines the set state of the tuning circuit unit A. The setting values shown in the chart of FIG. 3 represent the above 8-bit binary values in decimal notation. This set value is designed to be a value substantially proportional to the total capacitance value of the capacitors C1 to Cn connected in the tuning circuit portion A.

  The setting value registered in the default tuning capacity setting correspondence table 8d is, for example, a setting adjustment process before shipment from the factory. This is the default value obtained by executing for each channel. This value is not rewritten at the time of actual use after factory shipment.

  The setting value registered in the temporary storage tuning capacity setting correspondence table 9a is the setting value of the tuning circuit unit A that is obtained as the optimum value in accordance with the usage status of the apparatus during actual use. This value is rewritten every time an optimum set value of the tuning circuit unit A is found by performing a tuning capacity search process during actual use of the apparatus.

  In the above example, one set value is registered for each reception channel in the default tuning capacity setting correspondence table 8d and the temporary storage tuning capacity setting correspondence table 9a. When there are two or more types of standard radio wave reception environments, such as when the radio clock is placed and when it is worn on the wrist, the multiple tuning values obtained in these multiple reception environments are tuned for default. It may be registered in the capacity setting correspondence table 8d. Alternatively, a plurality of setting values registered in the past may be left as a history in the temporary storage tuning capacity setting correspondence table 9a.

  Next, the operation of the radio timepiece having the above configuration will be described.

[Time display processing]
The time display process is executed during the operation of the radio timepiece. During the operation of the radio timepiece, the clock circuit unit 13 counts the time based on a signal having a constant frequency from the oscillation circuit 12. The CPU 7 reads the time information of the timing circuit unit 13 or receives a signal (one-second elapsed signal, one-minute elapsed signal, etc.) indicating the update of a certain time from the timing circuit unit 13 and displays the display unit 11 Update the signal. As a result, the current time is displayed on the display unit 11.

[Time correction processing]
The time correction process is started when a predetermined time is reached. In addition, it may be started also when a predetermined external command is input from the input unit 10. When the time adjustment process is started, the CPU 7 operates the radio wave receiving unit 20 to receive the standard radio wave.

  In this reception process, the CPU 7 switches the characteristics of the BPF 2 of the reception circuit unit C in correspondence with the reception channel in association with the current reception channel. In addition, the tuning capacitance setting signal is output to the tuning circuit unit A and the switches S1 to Sn are switched to tune the resonance frequency of the antenna D to the frequency of the desired wave.

  When setting the tuning circuit unit A, the CPU 7 first reads the setting value corresponding to the current reception channel from the default tuning capacity setting correspondence table 8d of the EEPROM 8, and sets the tuning circuit unit A with this setting value. . Then, the reception process is executed.

  FIG. 4 is a characteristic diagram for explaining the difference between the default tuning capacity setting and the tuning capacity setting during actual use. In this characteristic diagram, the frequency level of a predetermined reception channel is input at a constant level, and the signal level sent to the detection circuit 4 is defined as the reception level, and the change in the reception level indicates the magnitude of the tuning capacity connected to the antenna D. It is expressed as a parameter.

  As shown by the solid line in FIG. 4, when there is no conductor such as metal in the periphery, the peak reception level V0 is obtained when the tuning circuit A is set to the tuning capacitor CA0, and the tuning circuit A is set. However, the reception level decreases as the value deviates from the tuning capacity CA0. The set value of the tuning circuit unit A to be the tuning capacitor CA0 is registered in the default tuning capacitor setting correspondence table 8d, for example.

  On the other hand, as shown by the one-dot chain line in FIG. 4, if there is a conductor such as a metal around the periphery, the inductance of the antenna D is reduced by the conductor, so that the peak when the setting of the tuning circuit portion A becomes the tuning capacitor CA1. The reception level decreases as the setting of the tuning circuit part A deviates from the tuning capacitor CA1. In other words, the setting value of the tuning circuit unit A where the peak of the reception level is obtained is slightly different depending on whether or not there is a conductor in the periphery.

  Therefore, when the default tuning capacity setting (tuning capacity CA0) is maintained and a conductor such as a metal comes close to the apparatus, the reception level V0b is very low. Therefore, when standard radio waves are received in such a situation, a tuning capacity search process is executed so that a high reception level V1 can be obtained even in such a situation, and tuning capacity setting suitable for this situation ( It is necessary to find the tuning capacitor CA1).

  Therefore, after setting the tuning circuit unit A with the values of the default tuning capacity setting correspondence table 8d as described above, if a reception level is not obtained by performing the reception process, the temporary storage tuning capacity of the RAM 9 is set. The setting value corresponding to the current reception channel is read from the setting correspondence table 9a, and the tuning circuit unit A is set with this setting value. Then, the reception process is executed again.

  In the temporary storage tuning capacity setting correspondence table 9a, the setting value of the tuning capacity circuit unit C obtained by performing the tuning capacity search process when a certain reception level cannot be obtained last time is registered. If the environment is the same as the current situation, a high reception level can be obtained by this setting.

  On the other hand, if a constant reception level cannot be obtained even in the previous setting, a tuning capacity search process for searching for the optimum setting of the tuning circuit unit A is executed to obtain an optimum setting value in accordance with the current situation. . If the optimum setting value is obtained, the CPU 7 overwrites and registers this setting value in the temporary storage tuning capacity setting correspondence table 9 a in the RAM 9. Then, the tuning circuit unit A is set with this set value, and the reception process is executed again.

  When the standard radio wave is received by the above-described reception processing and the time data (time code signal) is taken in by the CPU 7, the CPU 7 reads the time data and obtains time information indicating the current time. The CPU 7 corrects data in the time measuring circuit unit 13 and the display unit 11 based on the time information. Thereby, the time currently measured internally and the time displayed on the display part 11 are corrected.

[Tune capacity search processing]
The tuning capacity search process is performed by switching the setting of the tuning circuit unit A while monitoring the output level of the detection circuit 4 in a state in which the oscillation of the antenna D and the circuit unit of the tuning circuit unit A is performed. This is a process of searching for an optimal setting state of the tuning circuit section A in which the output level of the circuit 4 increases.

  When the tuning capacity search process is started, the CPU 7 puts the feedback circuit unit B into an operating state. Then, an oscillation loop is formed in the signal path of the feedback circuit unit B, the tuning circuit unit A, and the RF circuit 1, and an oscillation signal is generated in this portion. In this oscillation loop, the circuit constants that are dominant in determining the oscillation frequency are the inductance of the antenna D and the capacitance component of the tuning circuit section A. Therefore, the frequency of the oscillation signal is substantially the same as the resonance frequency of the coupling circuit of the antenna D and the tuning circuit unit A.

  When the oscillation signal is generated, the CPU 7 switches the switches S1 to Sn of the tuning circuit unit A to switch the total value of the tuning capacitors coupled to the antenna D over a predetermined adjustment range. By this switching, the resonance frequency of the antenna D is changed, and the frequency of the oscillation signal that is equal to this is also changed. Then, the CPU 7 performs AD conversion and captures the level of the detection output while switching the tuning circuit unit A.

  Here, if the resonance frequency of the antenna D deviates from the frequency of the desired wave by switching the setting of the tuning circuit unit A, an oscillation signal whose frequency is substantially equal to the resonance frequency is greatly attenuated by the BPF 2, so that the detection output The level becomes smaller. On the other hand, if the resonance frequency of the antenna D substantially overlaps the frequency of the desired wave by switching the setting of the tuning circuit unit A, an oscillation signal having a frequency substantially equal to the resonance frequency passes through the BPF 2 and raises the level of the detection output. .

  Therefore, the CPU 7 tunes the setting state of the tuning circuit unit A at which the level of the detection output reaches a peak by switching the setting of the tuning circuit unit A, so that the resonance frequency of the antenna D is tuned to the frequency of the desired wave. Obtained as the setting state.

  Note that the signal monitored by the CPU 7 during the tuning capacity search process is not limited to the output signal of the detection circuit 4 and may be any signal as long as the level of the signal passing through the BPF 2 can be detected. Further, when automatic gain control is performed for each amplifier of the radio wave receiver C, an increase in the level of a signal that has passed through the BPF 5 can be detected by monitoring the control voltage for automatic gain control.

  This tuning capacity search process is performed not only when a certain reception level cannot be obtained in the above-described time correction process, but also, for example, performed during a setting adjustment process before factory shipment. In this setting adjustment step, a tuning capacity search process is performed for each of the plurality of reception channels, and optimum setting values for the tuning circuit unit A are obtained. When these setting values are obtained, these setting values are written into the default tuning capacity setting correspondence table 8d of the EEPROM 8 by the CPU 7 or by an external writing device.

  Hereinafter, the time correction process and the tuning capacity search process executed therein will be described in detail with reference to the flowcharts of FIGS.

  FIG. 5 shows a flowchart of time correction processing executed by the CPU 7.

  In the time correction process, first, the CPU 7 determines whether or not the current time is the reception time in step J1, and if not, the CPU 7 repeats the standby process until the reception time is reached.

  If it is determined in step J1 that the current time has become the reception time, the process proceeds to step J2, and based on the home time setting information set in the RAM 9, the frequency of the current reception channel from the home time-reception channel correspondence table in the EEPROM 8 Read information.

  Next, the process proceeds to step J3, and the CPU 7 reads out the setting value of the tuning circuit unit A corresponding to the frequency information read out in step J2 from the default tuning capacitor setting correspondence table 8d, and uses this setting value to load the tuning circuit unit A. The standard radio wave is received by the radio wave receiving unit 20 after setting. Next, the process proceeds to step J4, where time data is input via the ADC 6 and the signal level is detected as the reception level.

  Subsequently, in step J5, the CPU 7 compares the reception level detected in step J4 with a predetermined threshold strength. As a result, if the reception level is equal to or higher than a predetermined threshold, it is determined that there is no problem in reception, and the process proceeds to J12 as it is. On the other hand, if the reception level is less than the threshold, it is determined that there is a possibility that the antenna D may be out of synchronization, and the process proceeds to step J6.

  In step J6, the CPU 7 checks whether or not a setting value corresponding to the current reception channel is registered in the temporary storage tuning capacity setting correspondence table 9a of the RAM 9. As a result, if the set value is registered, the process proceeds to step J7, the set value is read from the temporary storage tuning capacity setting correspondence table 9a, and the setting of the tuning circuit unit A is changed using this set value. To do. Then, the radio wave receiving unit 20 receives the standard radio wave, and the process proceeds to Step J8.

  On the other hand, if the set value is not yet registered in the temporary storage tuning capacity setting correspondence table 9a, such as at the beginning of using the radio timepiece, the process proceeds to NO in the discrimination process of step J6, and the tuning capacity search of step J10 is performed. Move to processing subroutine.

  At step J8, the CPU 7 inputs time data via the ADC 6 and detects the reception level. Next, in step J9, the CPU 7 compares the reception level detected in step J8 with a predetermined threshold strength. If the result is equal to or greater than the threshold value, it is determined that the antenna D has been tuned with the set value of the temporary storage tuning capacity setting correspondence table 9a, and the process proceeds to step J12. On the other hand, if it is less than the threshold value, it is determined that there is a possibility that the antenna D is still out of synchronization even with this setting, and the process proceeds to a tuning capacity search processing subroutine of step J10.

  The tuning capacity search process at step J10 is a process for obtaining the optimum setting of the tuning circuit section A of the current reception channel, as will be described in detail later.

  When the tuning capacity search process is completed, the process proceeds to step J11, and the CPU 7 determines whether the tuning capacity search process is successful. As a result, if it is determined to be successful, the process proceeds to step J12. If it is determined to be unsuccessful, radio wave reception at this point is stopped, and the process returns to step J1 to repeat the standby process until the next reception time.

  When the reception level is determined to be greater than or equal to the threshold value in the determination process of step J5, the determination of the reception level is greater than or equal to the threshold value in the determination process of step J9, and the tuning capacity search process is determined to be successful in step J11. If so, the process proceeds to step J12 to receive a standard radio wave.

  When the standard radio wave is received, in the next step J13, the CPU 7 interprets the time information from the time data (time code signal) to determine the success or failure of the radio wave reception. As a result, if successful, the process proceeds to Step J15, and if there is a deviation between the acquired time information and the time information of the time measuring circuit unit 13, this is corrected. Thereafter, the process proceeds to step J16, the reception time of the next standard radio wave is set (for example, the same time on the next day), and the process returns to step J1.

  If it is determined in step J3 that the radio wave reception is unsuccessful, it can be determined that the radio wave condition is bad and reception is not possible.

  By such time adjustment processing, the setting of the tuning circuit unit A is appropriately switched at the time of reception of the standard radio wave, so that the standard radio wave is received with high reception sensitivity and accurate time correction is performed. ing. Further, when the standard reception environment is used, the setting value of the default tuning capacity setting correspondence table 8d is used, so that the radio wave can be received promptly, and the reception deviating from the standard such as the proximity of metal or the like. Even in the environment, if the previous reception was performed in the same environment, the radio wave can be quickly received by using the setting value of the temporary storage tuning capacity setting correspondence table 9a. Furthermore, when the reception environment is deviated from the standard, the optimum setting value of the tuning circuit unit A corresponding to the current reception environment is obtained by the tuning capacity search process, and thereby high-sensitivity radio wave reception is performed. It has come to be.

  FIG. 6 shows a flowchart of the tuning capacity search process executed in step J10 of FIG.

  When the process proceeds to the tuning capacity search process, first, the CPU 7 operates the feedback circuit unit B in step J21. Thereby, loop oscillation is performed in the circuit portion of the antenna D and the tuning circuit portion A, and this oscillation signal is sent to the receiving circuit portion C.

  Next, in step J22, the CPU 7 reads the adjustment range (search range) of the tuning circuit unit A corresponding to the reception channel from the search range table of the EEPROM 8, and designates its initial value and end value.

  When the initial value and end value of the search range are designated, the process proceeds to step J23, where the CPU 7 outputs a setting signal to the tuning circuit unit A to set the tuning circuit unit A corresponding to the initial value. When the setting of the tuning circuit unit A is switched, the setting value of the tuning circuit unit A is sequentially stored in the data comparison storage area of the RAM 9 (step J24), and the output value of the ADC 6 representing the detection output level is used as the reception level. The data is input and stored in another storage area for data comparison in the RAM 9 (step J25), then the setting value of the tuning circuit unit A is changed by one step (step J26), and the setting value of the tuning circuit unit A is the end value. (Step J27), and if the end value has not yet been reached, the reception level that is the output value of the current ADC 6 is lower than the previous reception level stored in step J25 by a predetermined threshold value. Determine if it has become. (Step J28). This threshold value is set to a value that can exclude a change in the reception level due to noise from the determination of peak detection of the reception level.

  If the determination results at steps J27 and J28 are both NO, the loop processing at steps J24 to J28 is repeated. By this loop processing, the setting of the tuning circuit unit A is switched so that the value of the tuning capacitance coupled to the antenna D continuously changes from the initial value to the end value, and the setting switching of the tuning circuit unit A is switched. The reception levels before and after are compared under certain conditions.

  During the repetition process, if the resonance frequency of the antenna D overlaps with the frequency of the desired wave due to setting switching of the tuning circuit unit A, the reception level detected by the CPU 7 and stored in the data comparison storage area increases. . Next, when one setting of the tuning circuit unit A is switched and the resonance frequency of the antenna D slightly deviates from the frequency of the desired wave, the reception level detected by the CPU 7 decreases. Therefore, this decrease in the reception level is detected by the discrimination process in step J28.

  If the decision result in the step J28 is YES, it can be judged that the reception level has reached the peak at the setting immediately before the setting of the current tuning circuit section A, so the process goes through the loop process and proceeds to the step J29. The setting value of the tuning circuit section A stored in J24 is stored in the temporary storage tuning capacity setting correspondence table 9a in the RAM 9 in association with the current reception channel.

  Each time the setting of the tuning circuit unit A is switched as described above, the setting of the tuning circuit unit A is switched in all steps from the initial value to the end value, instead of comparing the reception levels before and after that. It is also possible to store the reception level at and to detect the peak of the reception level from these and obtain the set value of the tuning circuit unit A from which the peak is obtained.

  Thereafter, in step J30, the setting of the tuning circuit unit A is switched with the stored setting value. In step J31, the operation of the feedback circuit unit B is turned off, and the tuning capacitance search process is terminated. Here, when the tuning capacity search process is completed, a return value indicating a successful process result is returned to the caller process.

  On the other hand, if it is determined that the search range has reached the end value in the determination process in step J27 without obtaining a YES result in the determination process in step J28, the process proceeds to step J32 and the feedback circuit section B Turn off operation. In step J33, the reception time of the next standard radio wave is set (for example, after one hour), and the tuning capacity search process is terminated. Here, when the tuning capacity search process is completed, a return value indicating the process result of the failure is returned to the caller process.

  Through the tuning capacity search process as described above, it is possible to obtain the optimum setting value of the tuning circuit unit A according to the reception environment of the radio wave even during actual use of the apparatus without giving a frequency signal of the reception channel from the outside.

  As described above, according to the radio-controlled timepiece and radio-wave receiving apparatus of the present embodiment, the setting of the tuning circuit unit A that matches the resonance frequency of the antenna with the frequency of the desired wave is used as default information. In addition to being held at 8d, there is a temporary storage tuning capacity setting correspondence table 9a in which the optimum setting value of the tuning circuit section A obtained during actual use can be registered. By performing radio wave reception using the set value of the circuit unit A, the resonance frequency of the antenna D can be quickly set in a standard reception environment or when the reception environment is different even if the reception environment is different. High-sensitivity radio wave reception can be performed in synchronization with the frequency of the reception channel.

  If a predetermined reception level cannot be obtained by the reception process using both the setting value of the default tuning capacity setting correspondence table 8d and the setting value of the temporary storage tuning capacity setting correspondence table 9a, the tuning capacity search process is performed. Thus, the radio wave reception is performed by obtaining the optimum setting of the tuning circuit unit A. Therefore, even when the radio wave reception environment changes, the radio wave reception can be performed with good reception sensitivity.

  In addition, since it is considered that a change in the radio wave reception environment that causes the antenna D to be out of tune does not occur very frequently, the reception is first performed with the setting of the default tuning circuit unit A, and the reception state is not good. Next, reception is performed with the setting of the tuning circuit unit A stored in the temporary storage tuning capacity setting correspondence table 9a. If the reception state is not good in this case as well, the reception is performed by performing the tuning capacity search process. In many cases, the time required for radio wave reception can be shortened.

  Further, since the default setting value of the tuning circuit section A is stored in a nonvolatile storage medium such as the EEPROM 8, the default setting value is not lost even when the battery runs out. Since the temporary storage tuning capacity setting correspondence table 9a is provided in a volatile storage medium such as the RAM 9, data can be rewritten with low power consumption.

  In the default tuning capacity setting correspondence table 8d and the temporary storage tuning capacity setting correspondence table 9a, a plurality of setting values corresponding to a plurality of reception channels can be registered. It is also possible to deal with the case where

  Even in the case of corresponding to a plurality of reception channels, the setting values stored in the temporary storage tuning capacity setting correspondence table 9a are only the setting values corresponding to the reception channels set at the time of reception. Compared with the case where the set value is obtained and stored in the temporary storage tuning capacity setting correspondence table 9a, unnecessary processing can be omitted and reception processing can be performed promptly.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above embodiment, at the time of radio wave reception, first, the setting value of the default tuning capacity setting correspondence table 8d is used, and when a predetermined reception level cannot be obtained, the temporary storage tuning capacity setting correspondence table 9a Although set values are used, this order may be reversed.

  In the above-described embodiment, the tuning capacity setting correspondence tables 8d and 9a corresponding to the frequencies of 40 kHz, 60 kHz, and 77.5 kHz are shown, but the table may correspond to only a single frequency. It is possible to support more receiving channels such as 5 kHz and 75 kHz.

  In the above embodiment, an example in which the present invention is applied to a straight receiving circuit has been described. However, the present invention can also be applied to a super heterodyne receiving circuit or a direct conversion receiving circuit. In the above embodiment, a configuration is shown in which a radio wave receiving device is mounted on a radio timepiece and receives standard radio waves. However, the type of radio wave receiving device and the type of radio wave receiving device are not particularly limited. Absent. In addition, the details shown in the embodiments can be appropriately changed without departing from the spirit of the invention.

2 BPF
4 Detection circuit 6 ADC
7 CPU
8 EEPROM
8d Default tuning capacity setting correspondence table 9 RAM
9a Tuning capacity setting correspondence table for temporary storage A Tuning circuit part B Feedback circuit part C Reception circuit part C1 to Cn Capacitor D Antenna S1 to Sn switch Sw switch

Claims (6)

An antenna for receiving radio waves,
Tuning means capable of switching the frequency characteristics of the antenna;
Oscillating means capable of oscillating a circuit portion of the antenna and the tuning means;
A reception processing means for performing signal processing by extracting a signal of a desired wave from the reception signals received from the antenna;
Search control means for generating an oscillation signal in the circuit portion by the oscillation means and searching for the setting of the tuning means in which the oscillation signal is extracted by the reception processing means while switching the setting of the tuning means;
First storage means for storing default setting information of the tuning means;
Second storage means for storing setting information of the tuning means obtained by the search control means during actual use of the device;
A radio wave receiving apparatus comprising:   When the radio wave reception is performed and the predetermined reception level cannot be obtained, the search control unit is operated, and the setting of the tuning unit is detected when the search control unit detects the setting of the tuning unit that increases the reception level. 2. The radio wave receiving apparatus according to claim 1, further comprising: a reception control unit that performs radio wave reception and stores setting information of the tuning unit in the second storage unit. The reception control means includes
When the tuning means is set to the setting indicated by the setting information of the first storage means and a predetermined reception level cannot be obtained, the tuning means is switched to the setting indicated by the setting information of the second storage means. 3. The radio wave receiving apparatus according to claim 2, wherein when a predetermined reception level cannot be obtained after switching, the search control means is operated to search for a setting of the tuning means for increasing the reception level. . The first storage means is a nonvolatile storage means;
2. The radio wave receiving apparatus according to claim 1, wherein the second storage unit is a volatile storage unit. The reception processing means is configured to be able to perform signal processing on the reception signals of a plurality of reception channels,
The tuning means has an adjustment range capable of tuning the resonance frequency of the antenna to the frequency of the plurality of reception channels, respectively.
2. The radio wave receiving apparatus according to claim 1, wherein each of the first storage unit and the second storage unit has a storage area for storing a plurality of setting information corresponding to the plurality of reception channels. A plurality of setting information corresponding to a plurality of reception channels is stored in the first storage unit and the second storage unit,
The reception control means causes a search for the setting of the tuning means corresponding to one reception channel to be received when radio reception is performed and a predetermined reception level cannot be obtained, and increases the reception level. 3. The radio wave receiving apparatus according to claim 2, wherein when the setting of the tuning means to be detected is detected, the setting information of the tuning means is stored in the second storage means in correspondence with the one reception channel.

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