JP2009080141A - Radio receiver, wave clock, and radio reception control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce power consumption by quickly receiving a standard wave for time calibration. <P>SOLUTION: A P signal is detected from a time code generated as needed in accordance with a signal on a received standard wave. Then, if the second of the internal time when detected takes on a units digit of "5 to 9", the units digit is turned into "0" by carrying the units digit one second after the detection of the P signal. When the second of the internal time takes on a units digit of "0 to 4", the units digit is turned into "0", without carrying the units digit one second after the detection of the P signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio wave receiving apparatus, a radio timepiece, and a radio wave receiving integrated circuit.

  At present, time data, that is, a standard radio wave including a time code is transmitted in each country (for example, Germany, the United Kingdom, Switzerland, Japan, etc.). In Japan (Japan), two transmitting stations (Fukushima Prefecture and Saga Prefecture) transmit 40 kHz and 60 kHz long wave standard radio waves, which are time-modulated time information (time code) using a standard radio wave format. The time code of the standard radio wave is transmitted in a frame of 60 seconds per cycle every time the minute digit of the correct time is updated, that is, every minute.

  A so-called radio timepiece that receives this standard radio wave and corrects the data of the time measurement time (hereinafter referred to as “internal time” as appropriate) has been commercialized.

  A radio timepiece generally receives a standard radio wave once a day at a fixed time, for example, at 2:00 AM. The standard radio wave may be received at all times, but in that case, the power consumption for the operation of the radio wave receiving circuit will increase, and the relationship between the time interval for correcting the time and the allowable time error will be one day. The reason is that a correction of about once is sufficient.

  However, in a wristwatch type radio-controlled timepiece or the like, power consumption is a problem directly related to the continuous operation time as a timepiece, and thus further reduction of power consumption is required. Therefore, various techniques for reducing the operation time of the radio wave receiving circuit as much as possible to suppress power consumption have been invented. For example, when the entire time code related to one frame included in the standard radio wave is received and the entire internal time is corrected, a time code switching signal called an M signal (hereinafter, referred to as “minute signal” as appropriate). There has been known an invention for appropriately switching between the case of correcting the second part data of the internal time by using (see, for example, Patent Document 1).

JP 2000-235093 A

  However, it takes at least 60 seconds to receive one entire time code. Actually, however, the time required for the reception of the radio wave receiving circuit to be stable, or the time code for receiving at least one frame is required. Since it is necessary to consider allowance time etc., it was necessary to continue the reception state for 120 seconds or more. In addition, when receiving the equivalence signal described in Patent Document 1, the standard radio wave is continuously received until the equivalence signal is received, and the reception of the radio wave receiving circuit is stabilized. Considering the time required, the reception state is continued at least for a time corresponding to one frame. Therefore, it takes a long time to receive the standard radio wave.

In view of the problems described above, an object of the present invention is to reduce power consumption by receiving a standard radio wave for time correction in a short time.

In order to solve the above problems, the radio wave receiver of the invention described in claim 1 is:
A time measuring means for measuring time (for example, the time measuring circuit unit 80 in FIG. 1);
Receiving means (for example, the radio wave receiving circuit unit 60 in FIG. 1) for receiving a part of the standard radio wave transmitted by modulating the time data in frame units;
Identification data detection means (for example, the CPU 10 in FIG. 1; step A20 in FIG. 3; FIG. 5) that detects identification data arranged in the frame at predetermined time intervals in the standard radio wave received by the reception means. Step C18 and step D20) of FIG.
Time correction means (for example, the CPU 10 in FIG. 1; steps A24, A26 in FIG. 3, FIG. 3) for correcting the time measured by the time counting means based on the detection timing of the identification data detected by the identification data detection means. Step C26 of FIG. 5 and step D22) of FIG.
It is characterized by providing.

The invention described in claim 2 is the radio wave receiver according to claim 1,
Time is measured by the time counting means from the elapsed time from the previous correction time by the time adjusting means to the time measured by the time counting means and the predetermined design timing accuracy of the time counting means. Error range calculation means (for example, CPU 10 in FIG. 1; steps A10 and A12 in FIG. 3) for calculating the error range of the time being
When the error calculated by the error calculating means is within a predetermined range, the detection timing of the identification data detected by the identification data detecting means is detected later than the scheduled detection timing or detected further. Detection timing determination means (for example, CPU 10 in FIG. 1; step A22 in FIG. 3) for determining whether or not
When the detection timing determining means determines that the time is delayed, the time advance correcting means (for example, the CPU 10 in FIG. 1; step A24 in FIG. 3) corrects the time counted by the time measuring means. When,
A time delay correcting means (for example, the CPU 10 in FIG. 1; step A26 in FIG. 3) for correcting to delay the time measured by the time measuring means when it is determined that the time is advanced by the detection timing determining means; ,
It is characterized by having.

The invention described in claim 3 is the radio wave receiver according to claim 1,
Time is measured by the time counting means from the elapsed time from the previous correction time by the time adjusting means to the time measured by the time counting means and the predetermined design timing accuracy of the time counting means. Error range calculation means (for example, CPU 10 in FIG. 1; steps C8 and C10 in FIG. 5) for calculating an error range of the current time,
The receiving means determines a reception time based on the error range calculated by the error range calculating means, and receives an error range reference receiving means (for example, the CPU 10 in FIG. 1) at the determined reception time. Step C14) of FIG.
There is further provided collating means (for example, CPU 10 in FIG. 1; step C20 in FIG. 5) for collating the time data of the standard radio wave received by the error range reference receiving means with the time measured by the time measuring means. ,
The time correction means corrects the second part of the time counted by the time counting means based on the detection timing of the identification data detected by the identification data detection means when it is determined that the matching means matches. A second part correcting means (for example, CPU 10 in FIG. 1; step C26 in FIG. 5).
It is characterized by that.

According to a fourth aspect of the present invention, in the radio wave receiver of the first aspect,
The time correction means includes
When the time counted by the time counting means becomes the time when the identification data is scheduled to be detected, the time stopping means (for example, the CPU 10 in FIG. 1) performs control to stop the time counting by the time counting means. Steps D16 and D18) of FIG.
Time-resumption means (for example, the CPU 10 in FIG. 1; steps D20 and D22 in FIG. 8) for performing control to resume the time measurement by the time-clocking means in response to detection of identification data by the identification-data detection means;
It is characterized by having.

The radio timepiece of the invention described in claim 5 is:
A time measuring means for measuring time (for example, the time measuring circuit unit 80 in FIG. 1);
Receiving means (for example, the radio wave receiving circuit unit 60 in FIG. 1) for receiving a part of the standard radio wave transmitted by modulating the time data in frame units;
Identification data detection means (for example, the CPU 10 in FIG. 1; step A20 in FIG. 3; FIG. 5) that detects identification data arranged in the frame at predetermined time intervals in the standard radio wave received by the reception means. Step C18 and step D20) of FIG.
Time correction means (for example, the CPU 10 in FIG. 1; steps A24, A26 in FIG. 3, FIG. 3) for correcting the time measured by the time counting means based on the detection timing of the identification data detected by the identification data detection means. Step C26 of FIG. 5 and step D22) of FIG.
Display means (display unit 30 in FIG. 1) for displaying the current time measured by the time counting means;
It is characterized by providing.

The radio wave receiving integrated circuit of the invention described in claim 6 is:
A receiving circuit (for example, the radio wave receiving circuit unit 60 in FIG. 1) that receives a part of a standard radio wave that is transmitted with time data modulated in frame units;
An identification data detection circuit (for example, the CPU 10 in FIG. 1; step A20 in FIG. 3; FIG. 5) that detects identification data arranged in a predetermined time interval in the frame in the standard radio wave received by the reception circuit. Step C18 and step D20) of FIG.
A time correction circuit (for example, CPU 10 in FIG. 1; steps A24 and A26 in FIG. 3; step C26 in FIG. 5) that corrects the internal time that is counted based on the detection timing of the identification data detected by the identification data detection circuit. And step D22) of FIG.
It is characterized by providing.

  According to the invention described in claim 1 or 6, the time measured is corrected based on the detection timing of the identification data arranged at a predetermined time interval in the received standard radio wave. The Therefore, it is not necessary to receive all the frames of the standard radio wave, and the standard radio wave can be received in a short time. For this reason, it is possible to reduce power consumption related to reception of standard radio waves.

  According to the second aspect of the present invention, when the detection timing of the detected identification data is detected later than the scheduled detection timing, the clocked time is advanced by advancing the clocked time. Is fixed. In addition, when the detection timing of the detected identification data is detected ahead of the scheduled detection timing, the clocked time is corrected by delaying the clocked time.

  According to the invention described in claim 3, the error range of the time measurement is calculated from the elapsed time from the previous correction time to the time measured by the time measuring means and the predetermined time measurement accuracy. A reception start time is calculated based on the calculated error range, and reception of the standard radio wave is started from the calculated reception start time. Then, the second portion of the time measured based on the detection timing of the identification data is corrected.

  According to the invention described in claim 4, when the timekeeping time is scheduled to detect the identification data, the timekeeping is stopped and the timekeeping is restarted in response to the detection of the identification data. The second part of the time is corrected.

According to the fifth aspect of the present invention, a radio wave in which the time measured is corrected based on the detection timing of identification data inserted at a predetermined time interval in the received standard radio wave. A clock can be realized.

The figure which shows the structure of the radio timepiece in this invention. The figure which shows the characteristic of a time code format. The figure which shows the operation | movement flow of the 1st standard radio wave reception process in 1st Embodiment of this invention. The figure which shows the structure of ROM in 2nd Embodiment of this invention. The figure which shows the operation | movement flow of the 2nd standard radio wave reception process in 2nd Embodiment of this invention. The figure for demonstrating operation | movement of the 2nd standard wave reception process in 2nd Embodiment of this invention. The figure which shows the structure of ROM in 3rd Embodiment of this invention. The figure which shows the operation | movement flow of the 3rd standard radio wave reception process in 3rd Embodiment of this invention. The figure for demonstrating operation | movement of the 3rd standard radio wave reception process in 3rd Embodiment of this invention. The figure for demonstrating the time code format in each country. The figure for demonstrating the time code format in Japan.

  Next, an embodiment in which the present invention is applied to a radio timepiece which is a type of radio wave receiver will be described in detail with reference to the drawings.

  First, the format of the time code generated from the standard radio wave will be described. In the time code shown in FIG. 11, time information having a format of one cycle of 60 seconds is transmitted as one frame every minute. The format of this time code is as follows. That is, an M signal is arranged at the head of the rising edge of the minute (0 seconds per minute), which is the start time point of the 60-second frame. This M signal has a pulse width of 0.2 seconds, and the same P signal with a pulse width of 0.2 seconds is 9 seconds (P1), 19 seconds (P2), 29 seconds (P3), It is also arranged at the time of 39 seconds (P4), 49 seconds (P5) and 59 seconds (P0).

  For this reason, two frames having a pulse width of 0.2 seconds (that is, the leading M signal and P signal) are arranged on the frame boundary at intervals of approximately 1 second. The start of the frame can be recognized. Further, the M signal is a signal indicating a frame reference, and the rising edge of the pulse indicated by the M signal is an accurate update of the digit of the current time. In the frame, the time data at the time of the start of the frame is 0 to 9 seconds, the hour data is 10 to 19 seconds, and the total date (number of days from January 1) Data in 20th to 39th, year (last 2 digits) data in 40th to 49th, day of the week in 50th to 59th, etc. In this case, logics 1 and 0 are represented by pulses having pulse widths of 0.5 seconds and 0.8 seconds, respectively. In the frame shown in FIG. 11, data at 17:25 on the 114th day is shown.

  The inventor has discovered that there is a certain characteristic (regularity) by analyzing the time code format. The characteristics of the time code format are shown in FIG. As shown in FIG. 2, for example, in the case of a P signal, it is distributed once every 10 seconds. Accordingly, when the time is corrected using the standard radio wave, the time can be corrected at high speed by using the position of the P signal (9th second) if the error is within ± 5 seconds. Further, the M signal is arranged only at the 0th to 10th seconds, and is the start time of the equidistant time. Therefore, when the time is corrected using the standard radio wave, the time can be corrected at high speed by using the M signal if the error is within ± 30 seconds.

  As described above, by using the characteristics of the time code in combination, high-speed time correction can be performed without receiving the entire time code related to one frame. An error in time measured by a time measuring circuit incorporated in a general clock is approximately a monthly difference of about ± 15 seconds. Therefore, even if the radio timepiece receives the standard radio wave only once within one week, the time error is usually within ± 5 seconds. Therefore, in the present embodiment, as an example, a description will be given of performing faster time correction by paying attention to the P signal.

[First Embodiment]
First, the first embodiment will be described. In the first embodiment, the second part of the internal time measured by the time measuring circuit unit 80 is corrected by using the P signal included in the received standard radio wave.

[1.1 Configuration]
[1.1.1 Overall configuration]
FIG. 1 is a block diagram illustrating an example of a functional configuration of the radio timepiece 1. According to FIG. 1, a radio timepiece 1 includes a CPU (Central Processing Unit) 10, an input unit 20, a display unit 30, a ROM (Read Only Memory) 40, a RAM (Random Access Memory) 50, and a radio wave reception. A circuit unit 60, a time code generation circuit unit 70, and a clock circuit unit 80 that counts clock signals output from the oscillation circuit unit 90 and obtains current time data are connected to the bus 100.

[1.1.2 Input / Display]
The input unit 20 includes a switch for causing the radio timepiece to execute various functions, and outputs an operation signal corresponding to the pressed switch to the CPU 10 when the switch is pressed by the user.

  The display unit 30 is a display device configured by, for example, an LCD (Liquid Crystal Display), a segment type display, or the like, and digitally displays the current date and time based on display data output from the CPU 10.

[1.1.3 ROM / RAM]
The ROM 40 is a read-only memory that mainly stores system programs and application programs related to the radio timepiece. According to FIG. 1, the ROM 40 stores a first standard radio wave reception program 402.

  The RAM 50 is a memory that can be written at any time to temporarily hold various programs executed by the CPU 10, data related to the execution of these programs, and the like. In the present embodiment, the time when the previous internal time was corrected based on the received standard radio wave (hereinafter referred to as “previous correction time” as appropriate) is stored in the previous correction time data 502. For example, the radio timepiece 1 corrects (initializes) the internal time by receiving the entire time code at least once, and the time at this time is stored as the previous correction time data 502.

[1.1.4 CPU]
The CPU 10 reads various programs stored in the ROM 40 in accordance with a predetermined timing or an operation signal output from the input unit 20, expands the program in the RAM 50, and instructs each functional unit based on the program. And data transfer. For example, the radio wave receiving circuit unit 60 is controlled to receive a standard radio wave at a predetermined time. Further, the time data as the internal time measured by the time measuring circuit unit 80 is corrected based on the time code output from the time code generating circuit unit 70, and the display of the current date and time is updated based on the corrected time data. Various controls are performed.

  The CPU 10 executes a first standard radio wave reception process (see FIG. 3) according to the first standard radio wave reception program 402 stored in the ROM 20. Specifically, the CPU 10 determines the time of the largest error (hereinafter referred to as “maximum” as appropriate) among the difference between the previous correction time and the current internal time, and the error per unit time that can occur in the time measuring circuit 80. The error range is calculated by multiplying the difference from “error unit time”). Further, the CPU 10 detects the P signal from the received standard radio wave, and corrects the second part of the internal time (hereinafter, appropriately referred to as “second part internal time”) according to the timing at which the P signal is detected.

[1.1.5 Radio wave receiving circuit section, etc.]
The radio wave receiving circuit unit 60 cuts unnecessary frequency components from the received signal received by the antenna ANT, extracts a signal having a frequency corresponding to the standard radio wave, detects the extracted signal, and supplies the signal to the time code generation circuit unit 70. Output at any time. In this case, by realizing a high-speed AGC operation based on Japanese Patent Application Laid-Open Nos. 2004-242157 and 2004-179948, the time lag from the start of reception until time information is generated and time code is generated is greatly increased. It can be shortened.

  The time code generation circuit unit 70 detects time information based on a signal output from the radio wave reception circuit unit 60, generates a time code as needed, and outputs the time code to the CPU 10.

[1.1.6 Timing circuit etc.]
The timer circuit unit 80 counts the clock signal output from the oscillation circuit unit 90 to obtain current time data (internal time) of the radio timepiece 1. Then, the current time data is output to the CPU 10. The oscillation circuit unit 90 is configured by a crystal oscillator or the like, and always outputs a clock signal having a constant frequency to the time measuring circuit unit 80.

[1.2 First standard radio wave reception processing]
Next, the operation process of the first standard radio wave process will be described. FIG. 3 is a flowchart for explaining the operation of the radio timepiece 1 according to the first standard radio wave reception process. This first standard radio wave reception process is a process realized by the CPU 10 executing the first standard radio wave reception program 402 stored in the ROM 40.

  First, the CPU 10 calculates, as R, the difference between the previous correction time stored in the previous correction time data 502 and the current time measured by the time measuring circuit unit 80 (step A10). Next, the CPU 10 multiplies the maximum error unit time by R calculated in step A10, thereby calculating the error range of the time counted by the time measuring circuit unit 80 (step A12). Here, the maximum error unit time means a time error range per unit time obtained from the time measurement accuracy of the time measurement circuit unit 80. That is, it is a range of errors generated in the time measuring circuit unit 80 per unit time (for example, “1 second”), for example, a value obtained by converting an error range of ± 15 seconds per month to an error range per second. .

  Subsequently, the CPU 10 determines whether or not the error range calculated in step A12 is within ± 5 seconds (step A14). Here, when the error range is out of the range within ± 5 seconds (step A14; No), the CPU 10 executes another time correction method. Here, another time correction method refers to, for example, a method of correcting the time based on the received time information of 1 to 3 frames as conventionally performed.

  On the other hand, when the error range calculated in step A12 is within ± 5 seconds (step A14; Yes), the CPU 10 causes the radio wave receiving circuit unit 60 to start receiving standard radio waves (step A16). The standard radio wave signal received by the radio wave receiving circuit unit 60 is output to the time code generation circuit unit 70 as needed. The time code generation circuit unit 70 generates a time code from time to time, and outputs it to the CPU 10 at any time (step A18). Subsequently, the CPU 10 detects one of the P signals included in the output time code (step A20).

  Here, at the time of detection of the P signal, when the 1's place of the second portion internal time is “5” to “9” (step A22; Yes), “1” seconds are detected after the P signal is detected. Later, the internal time of the second part is carried, and the first place is set to “0” seconds (step A24). That is, when the internal time has a delay of 5 seconds or less compared to the time of the standard radio wave received, the internal time is corrected by advancing the internal time.

  On the other hand, at the timing when the P signal is detected, if the 1's place of the second portion internal time is “0” to “4”, that is, the internal time is less than 5 seconds compared to the received standard time. If there is a lead (step A22; No), one second after detecting the P signal, the second part internal time is not carried and the first place is set to "0" seconds (step) A26). That is, when the internal time has an advance of less than 5 seconds compared to the time of the received standard radio wave, the internal time is corrected by delaying the internal time.

  Then, the CPU 10 causes the radio wave receiving circuit unit 60 to end the reception of the standard radio wave (step A28).

  A specific example will be described. When the value calculated as the error range is between 0 and −5 seconds, for example, at the timing when the P signal (for example, the pulse P2 in FIG. 11) is detected (“19” seconds at the time of the standard radio wave), For example, when the time measuring circuit 80 measures “16” seconds as the internal time (step A22; Yes), the CPU 10 carries the second partial internal time and corrects it to “20” seconds after “1” seconds. (Step A24). When the value calculated as the error range is between 0 and +5 seconds, for example, at the timing when the P signal (for example, the pulse P2 in FIG. 11) is detected, the time measuring circuit unit 80 sets the internal time, for example, “22 When the second has been counted (step A22; No), the internal time of the second part is not carried after “1” seconds and is corrected to “20 seconds” (step A26).

[1.3 Effect]
As described above, according to the first embodiment, when an error in the time measured by the time measuring circuit unit 80 with respect to the time of the standard radio wave is assumed to be within ± 5 seconds, the P signal is detected from the received standard radio wave. The time can be corrected based on the second digit of the second time measured by the time measuring circuit 80 when the P signal is detected. Thus, when correcting the time, it is not necessary to receive the entire time code related to one frame, and the time can be shortened compared to the case where the entire time code related to one frame is received.

[Second Embodiment]
Next, the second embodiment will be described.
[2.1 Configuration]
The configuration of the radio timepiece in the second embodiment is a configuration in which the ROM 40 shown in FIG. 1 is replaced with the ROM 42 shown in FIG. 4 in the first embodiment, and the same components as those in the first embodiment are the same in the following. Reference numerals are assigned and explanations thereof are omitted.

  The configuration of the ROM 42 will be described with reference to FIG. As shown in FIG. 4, the ROM 42 stores a second standard radio wave reception program 422. Here, the second standard radio wave reception program 422 is a program for realizing the second standard radio wave reception process in the present embodiment, and the CPU 10 executes the second standard radio wave reception program 422, whereby the second standard radio wave reception program 422 is executed. Radio wave reception processing is realized. Specifically, when an instruction operation for adjusting the time by receiving the standard radio wave is input by the user, the CPU 10 executes the second standard radio wave process. In the second standard radio wave processing, the CPU 10 assumes that the “time” partial data assumed as time data of the time code of the received standard radio wave and the “hour” part data at the internal time (hereinafter, the “time” partial internal If it is determined that the times coincide with each other, the next P signal is detected, and after “1” seconds, the second portion internal time is set to “20.00” seconds.

[2.2 Second standard radio wave reception processing]
Next, the second standard radio wave reception process will be described in detail. FIG. 5 is a flowchart for explaining the operation of the radio timepiece 1 according to the second standard radio wave reception process. This second standard radio wave reception process is a process realized by the CPU 10 executing the second standard radio wave reception program 422 stored in the ROM 42.

  First, the CPU 10 calculates, as R, the difference between the previous correction time stored in the previous correction time data 502 and the current time measured by the timing circuit unit 80 (step C8). Subsequently, the CPU 10 multiplies the maximum error unit time by R calculated in step C10, and calculates, for example, the result of adding “1” as S (step C10). Here, “1” is a margin for the maximum error unit time.

  Subsequently, the CPU 10 causes the radio wave receiving circuit unit 60 to start receiving the standard radio wave from S seconds before the time assumed to be the “hour” partial data in the time code of the standard radio wave scheduled to be received (step C14). . The standard radio wave signal received by the radio wave reception circuit unit 60 is output to the time code generation circuit unit 70 as needed. The time code generation circuit unit 70 generates a time code at any time according to a signal input at any time and outputs the time code to the CPU 10 (step C16). Subsequently, the CPU 10 detects a P signal included in the time code generated at any time by the time code generation circuit unit 70 (step C18).

  Subsequently, the “hour” partial data of the time code following the P signal detected in step C18 is collated with the “hour” partial internal time of the internal time measured by the time measuring circuit 80 (step C20). As a result of the collation, if it is determined that the data do not match (step C22; No), the reception of the standard radio wave is suspended for a predetermined time, and the process is repeated from step C14. Here, the predetermined time means a time for receiving the “hour” partial data again, for example, “50 seconds” after the “hour” partial data of the time code appears again.

  If it is determined in step C20 that the collated data matches (step C22; Yes), the P signal next to the “hour” partial data in the generated time code is detected, and one second later The “second” portion of the internal time is set to “20.00” seconds (step C26). Then, the CPU 10 causes the radio wave receiving circuit unit 60 to end the reception of the standard radio wave (Step C28).

  Here, it demonstrates concretely using a figure. FIG. 6 shows a part of the time code, and is a diagram in the case where the second standard radio wave reception process is executed at the internal time of “15”. The CPU 10 starts the reception of the standard radio wave from the timing T7 which is S seconds before the timing T10 which is the starting position of the assumed “hour” partial data. At time T9, the P signal (P1 signal) is detected. When the P signal is detected, the CPU 10 reads the “hour” partial data from the subsequent time code. Here, the “hour” portion data included in the time code is “15”, which coincides with “15” in the “hour” portion of the internal time. Therefore, the CPU 10 waits for detection of the next P signal. When the P signal (P2 signal) is detected at timing T19, the “second” portion of the internal time is set to “20.00” seconds at timing T20 one second later.

[2.3 Effects]
As described above, according to the second embodiment, when the “hour” partial data included in the time code of the standard radio wave matches the “hour” partial internal time of the internal time counted by the timing circuit unit 80, the internal time The “second” part of the time can be modified. Further, in the case of a general clock circuit, the error range of the internal time is usually about ± 15 seconds per month, so even if the time of one week is not corrected, the error range is within ± 5 seconds. Then, except for special circumstances, because the “hour” part data included in the time code of the standard radio wave and the “time” part internal time of the internal time match, it is efficient to receive the standard radio wave once, Time correction can be performed without consuming as much power as possible.

[2.4 Modification]
In the present embodiment, the second standard radio wave reception process is started in accordance with the user operation and the internal time is corrected. However, the second standard radio wave reception process is executed at a predetermined time. Of course, it is also good. Specifically, for example, when the internal time becomes “2:00 am”, the CPU 10 automatically executes the second standard radio wave reception process. In this case, in step C20, it is only necessary to compare whether or not the “hour” portion data of the time code matches the time “2” that is automatically received. In such a configuration, since the internal time is automatically corrected every day, the error range of the internal time is small, and the time for receiving the standard radio wave can be further shortened.
In the second embodiment, the “hour” partial data of the time code following the P signal is collated with the “hour” partial internal time of the internal time measured by the timing circuit unit 80, but the P signal is followed. The “minute” part data of the time code may be collated with the “minute” part internal time of the internal time measured by the time measuring circuit unit 80.

[Third Embodiment]
Subsequently, the third embodiment will be described.
[3.1 Configuration]
The configuration of the radio timepiece in the third embodiment is a configuration in which the ROM 40 shown in FIG. 1 in the first embodiment is replaced with the ROM 44 shown in FIG. 7, and the same components as those in the first embodiment are the same as those in the first embodiment. Reference numerals are assigned and explanations thereof are omitted.

  The configuration of the ROM 44 will be described with reference to FIG. As shown in FIG. 7, the ROM 44 stores a third standard radio wave reception program 442. Here, the third standard radio wave reception program 442 is a program for realizing the third standard radio wave reception process in the present embodiment, and the CPU 10 executes the third standard radio wave reception program 442 so that the third standard radio wave reception program 442 is executed. Radio wave reception processing is realized. Specifically, when the 1's place in the “second” portion of the internal time becomes “9”, the CPU 10 holds the 1's place of the “second” portion of the internal time at “9.00”. When the reception of the standard radio wave is started and the rising edge of the pulse of the P signal is detected, the internal time is corrected by releasing the holding of “9.00” and restarting the time measurement.

  Further, it is assumed that the time measuring circuit unit 80 of the third embodiment is set in advance so that the time measuring error is a progress error that always advances in comparison with the time of the received standard radio wave.

[3.2 Third standard radio wave reception processing]
Next, the third standard radio wave reception process will be described in detail. FIG. 8 is a flowchart for explaining the operation of the radio timepiece 1 according to the third standard radio wave reception process. This third standard radio wave reception process is a process realized by the CPU 10 executing the third standard radio wave reception program 442 stored in the ROM 44.

  First, the CPU 10 calculates, as R, the difference between the previous correction time stored in the previous correction time data 502 and the current time measured by the timing circuit unit 80 (step D10). Subsequently, the CPU 10 determines whether or not a value obtained by multiplying the maximum error unit time by R calculated in step D10 is less than one second (step D12). If it is determined that the value is 1 second or longer (step D12; No), the CPU 10 executes another time correction method. Here, another time correction method is, for example, a method of correcting the time based on the received time information of 1 to 3 frames, as in the past, or a time based on the first standard radio wave processing. How to correct.

  On the other hand, when it is determined in step D12 that the value is less than 1 second (step D12; Yes), reception of standard radio waves is started (step D14). Then, it waits until the first place of the “second” portion of the internal time becomes “9” (step D16; No), and when it is determined that the first place becomes “9” (step D16; Yes). Stops the time counting of the time measuring circuit unit 80 and keeps the internal time of the second part at “9.00” (step D18).

  Then, the CPU 10 causes the radio wave receiving circuit unit 60 to start receiving the standard radio wave, and when the rising edge of the pulse wave of the P signal included in the received standard radio wave is detected (step D20; Yes), the time measuring circuit unit 80 Timekeeping is resumed (step D22). Further, the CPU 10 ends the reception of the standard radio wave by outputting an instruction to end the reception of the standard radio wave to the radio wave receiving circuit unit 60 (step D24).

Here, a specific example will be described with reference to FIG. FIG. 9 illustrates a part of the time code. First, the CPU 10 causes the radio wave receiving circuit unit 60 to start receiving standard radio waves. T1 is the timing when the 1's place in the “second” portion of the internal time becomes “9”. Since the timing circuit unit 80 is a lead error, the time “1” in the standard radio wave is not reached at the time T1 when the 1's place of the “second” portion of the internal time becomes “9”. At the time T1, the CPU 10 causes the timing circuit unit 60 to stop timing and to hold the second portion internal time. Then, the rise of the pulse waveform of the P signal (P2 signal) is detected at the timing T2. Therefore, the CPU 10 causes the timing circuit unit 60 to restart timing from the time T2.
In FIG. 9, the specific description has been given for the case of the P2 signal, but the same can be done for the P0 to P5 signals.

[3.3 Effects]
As described above, according to the third embodiment, when the error range is within one second, the time counting of the time measuring circuit unit 80 is performed when the first digit of the “second” portion of the internal time becomes “9”. Is stopped, and the internal time can be corrected by restarting the timing of the timing circuit unit 80 when the P signal is detected. As a result, the reception of the standard radio wave is extremely short.

[3.4 Modification]
In the above-described embodiment, the time measurement is restarted as soon as the rising edge of the pulse wave of the P signal is detected. However, in consideration of the time lag from when the P signal is received until the internal time is corrected, for example, The time may be corrected after a predetermined time such as one second later. For example, if it is considered that a delay of “50” milliseconds occurs in the time lag, the internal time is carried after “950” milliseconds after receiving the P signal, and the first digit is changed to “0” seconds. By performing the above, it becomes possible to correct the internal time more accurately.

  In the above-described embodiment, the error characteristic of the time measuring circuit unit 80 has been described as an advance error, but it is needless to say that it may have a delay error characteristic. In this case, the reception of the standard radio wave is started when the 1's digit of the “second” portion of the internal time becomes “8”, and the rising edge of the pulse of the P signal is detected. The one's place should be corrected to “9”.

[Modification]
[4. Modified example]
In the above-described embodiment, the time is corrected according to the standard radio wave transmitted in Japan. However, the present invention can be similarly realized when the time is adjusted according to the foreign standard radio wave in a foreign country.

  However, since the time code format of the standard radio wave is different in each country, it is necessary to change the design according to the time code format in each country.

  FIG. 10 is a diagram showing a part of the time code format of each country. (A) shows the time code format used in Japan (JJY), (b) shows the United States (WWVB), and (c) shows the time code format used in Germany (DCF77). Here, as shown in FIG. 10A, in Japan, the timing of every second is the rising edge of the pulse wave, but in the United States and Germany, the falling edge of the pulse wave is every second. Therefore, the design may be changed so that the end (falling) of the pulse wave is detected when the P signal is detected.

  Further, as shown in FIG. 10C, the German time code does not include the P signal. In this case, the internal time may be corrected by using appropriate time partial data. For example, in the case of FIG. 10C, the internal time can be corrected by using the M signal as identification data.

In the present embodiment, the time is corrected by detecting the P signal once. However, the internal time may be corrected after receiving the P signal a plurality of times. In this case, it is necessary to receive the standard radio wave for a long time compared to the case where the correction is performed once. However, even when the standard radio wave is not stable due to noise or the like, the time can be accurately corrected. It is valid.

1 Radio clock 10 CPU
20 Input unit 30 Display unit 40, 42, 44 ROM
402 First standard radio wave reception program 422 Second standard radio wave reception program 442 Third standard radio wave reception program 50 RAM
60 radio wave receiving circuit unit 70 time code generating circuit unit 80 timing circuit unit 90 transmitting circuit unit

Claims (6)

A time keeping means for keeping time, and
Receiving means for receiving a part of a standard radio wave transmitted by modulating time data in frame units;
Identification data detecting means for detecting identification data arranged at predetermined time intervals in the frame in the standard radio wave received by the receiving means;
Time correction means for correcting the time counted by the time counting means based on the detection timing of the identification data detected by the identification data detection means;
A radio wave receiving apparatus comprising: Time is measured by the time counting means from the elapsed time from the previous correction time by the time adjusting means to the time measured by the time counting means and the predetermined design timing accuracy of the time counting means. An error range calculation means for calculating an error range of the current time;
When the error calculated by the error range calculation means is within a predetermined range, the detection timing of the identification data detected by the identification data detection means is detected later than the scheduled detection timing, or is detected Detection timing determination means for determining whether or not
A time advance correction means for performing a correction to advance the time counted by the time counting means when it is determined that the time is delayed by the detection timing determination means;
A time delay correcting means for correcting to delay the time measured by the time measuring means when it is determined that the detection timing determining means has advanced;
The radio wave receiver according to claim 1, comprising: Time is measured by the time counting means from the elapsed time from the previous correction time by the time adjusting means to the time measured by the time counting means and the predetermined design timing accuracy of the time counting means. An error range calculating means for calculating an error range of the current time,
The receiving means has an error range reference receiving means for determining a reception time based on the error range calculated by the error range calculation means, and receiving the standard radio wave at the determined reception time,
A collating unit for collating the time data of the standard radio wave received by the error range reference receiving unit with the time measured by the time measuring unit;
The time correction means corrects the second part of the time counted by the time counting means based on the detection timing of the identification data detected by the identification data detection means when it is determined that the matching means matches. Having a second part correcting means to
The radio wave receiver according to claim 1. The time correction means includes
When the time counted by the time counting means becomes the time when the identification data is scheduled to be detected, the time stopping means for controlling to stop the time counting by the time counting means,
In response to detection of identification data by the identification data detection means, timekeeping restarting means for performing control to restart timekeeping by the timekeeping means;
The radio wave receiver according to claim 1, comprising: A time keeping means for keeping time, and
Receiving means for receiving a part of a standard radio wave transmitted by modulating time data in frame units;
Identification data detecting means for detecting identification data arranged at predetermined time intervals in the frame in the standard radio wave received by the receiving means;
Time correction means for correcting the time counted by the time counting means based on the detection timing of the identification data detected by the identification data detection means;
Display means for displaying the current time measured by the time counting means;
A radio-controlled timepiece characterized by comprising: A receiving circuit that receives a part of a standard radio wave transmitted by modulating time data in frame units;
An identification data detection circuit for detecting identification data arranged at predetermined time intervals in the frame in the standard radio wave received by the reception circuit;
A time correction circuit for correcting the internal time being measured based on the detection timing of the identification data detected by the identification data detection circuit;
A radio wave receiving integrated circuit comprising:

Images