JP2007147328A - Radio-controlled clock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce power consumption generated by a receiving operation by simplifying an operation, and by shortening a reception time of a time code. <P>SOLUTION: An antenna 101 receives a standard radio wave, and a receiving circuit 102 extracts a time code included in the standard radio wave and outputs it to a control circuit 103. The control circuit 103 discriminates each digital signal constituting the time code in a prescribed time width unit and stores it successively in a memory 105. The control circuit 103 discriminates the kind of the time code based on the digital signal stored in the memory 105, discriminates a present time by analyzing the received time code based on the kind of the time code, corrects a clocked time and displays it on a display part 104. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radio-controlled timepiece that receives a time code including information on the current time by radio waves, and corrects the measured time to a time corresponding to the time code.

Conventionally, a radio timepiece has been developed that receives a standard radio wave including a time code representing the current time and automatically corrects the time measured by the time measuring means.
The frequency of the standard radio wave and the format of the time code are determined for each country.
FIGS. 8 to 10 are diagrams showing formats of digital signals constituting time codes used in Japan (identification code: JJY), the United States (identification code: WWVB), and the United Kingdom (identification code: MSF), respectively. Yes, the period of each digital signal representing signals "1", "0", etc. is 1 second. JJY has two types of radio wave frequencies of 40 kHz and 60 kHz, and WWVB and MSF are 60 kHz, which is the same as one frequency of JJY.

As shown in FIG. 8A, in JJY, a digital signal representing a P code is composed of a high modulation portion with a time width of 200 msec and a low modulation portion with a time width of 800 msec, and the digital signal representing the signal “1” is The digital signal representing the signal “0” is composed of a high modulation portion having a time width of 800 msec and a low modulation portion having a time width of 200 msec. ing.
In WWVB, as shown in FIG. 9, a digital signal representing a P code is composed of a low modulation portion with a time width of 200 msec and a high modulation portion with a time width of 800 msec, and signal “1” is a low modulation portion with a time width of 500 msec. The signal “0” is composed of a low modulation portion having a time width of 200 msec and a high modulation portion having a time width of 800 msec.

  In MSF, as shown in FIG. 10, a digital signal representing a P code indicating the beginning of a frame is composed of a low modulation portion having a time width of 500 msec and a high modulation portion having a time width of 500 msec. The signal “0” is composed of a low modulation portion having a time width of 100 msec and a high modulation portion having a time width of 900 msec, and is a parity check bit. The digital signal representing the PA code is composed of a low modulation portion with a time width of 300 msec and a high modulation portion with a time width of 700 msec.

In FIGS. 8 to 10, when the high modulation portion and the low modulation portion are demodulated, which signal format is output in the high level or the low level is determined by the configuration of the demodulation circuit or the like. It is possible to appropriately select whether to adopt a signal of the above level.
FIG. 11 is a diagram showing a part (59 seconds to 37 seconds) of a time code representing “July 11, 2005, 9:47” by JJY, WWVB, and MSF.

  Conventional radio timepieces were designed to receive only the standard radio waves of each country, that is, only one type of standard radio wave, but in recent years, there has been a multi-reception function that can receive standard radio waves from multiple countries and regions. Radio wave watches are also being commercialized. Because the standard radio frequency and time code of each country are different from each other, radio timepieces with multi-reception function must support multiple standard radio frequency and time code formats to be received. There is.

The radio timepiece with a built-in multi-reception function is roughly divided into a method in which a user designates and selects a receiving station by performing an operation (for example, refer to Patent Document 1), and a receiving station based on a reception result. There is a method (for example, refer to Patent Document 2) that automatically and sequentially switches.
In the method of specifying the receiving station, it is possible to minimize the time and energy consumption required for reception, but there is a problem that it is necessary to provide means for specifying and selecting the receiving station, which makes the operation complicated. .

  On the other hand, in Seibu that automatically switches the receiving station sequentially based on the reception result, there is no need to specify the receiving station, so the operation is simple, but there is a function that can receive multiple receiving stations of the same frequency The receiving station cannot be switched until reception fails. Therefore, even if it is determined whether the received data is different from the receiving station to be received based on the time code format, if the same code continues multiple times, it is determined correctly where the code starts. Since it may not be possible, it takes time to make a determination, and time and energy consumption are wasted.

  FIG. 12 is a diagram illustrating a case where a signal “0” is generated continuously for 6 bits in JJY and WWVB, and a case where a signal “1” is generated continuously for 6 bits in MSF. As shown in FIG. 12, the digital signal of each time code is a signal in which a high level signal having a width of 200 msec and a low level signal having a width of 800 msec are alternately repeated, and it is not possible to determine the type from these signals alone. Is possible. Therefore, since it is necessary to make a determination using another part of the time code, there is a problem that the determination takes time.

Paragraphs [0014] to [0018] and [0020] to [0026] of Japanese Patent Application Laid-Open No. 2003-121571, FIGS. Paragraphs [0075] to [0084] of Japanese Patent Application Laid-Open No. 2004-4136, FIGS. 12 to 14

  An object of the present invention is to make it possible to reduce the power consumption caused by the reception operation by simplifying the operation and shortening the reception time of the time code.

  According to the present invention, in a radio timepiece that receives a time code including current time information by radio waves and corrects the time measured by the time measuring means to a time corresponding to the received time code, the time code is received by radio waves. Receiving means, storage means for sequentially identifying and storing digital signals constituting the time code in predetermined time width units, and determining means for determining the type of the time code based on the digital signals stored in the storage means And a correcting means for analyzing the received time code based on the type of the time code determined by the determining means to determine the current time and correcting the time measured by the time measuring means. Is done.

  The receiving means receives a time code including information on the current time by radio waves. The storage means sequentially identifies and stores digital signals constituting the time code in units of a predetermined time width. The discriminating unit discriminates the type of the time code based on the digital signal stored in the storage unit. The correcting means analyzes the received time code based on the type of time code determined by the determining means to determine the current time, and corrects the time measured by the time measuring means.

Here, it has edge detection means for detecting a predetermined direction edge of the digital signal constituting the received time code, and the storage means stores the time code on the basis of the predetermined direction edge detected by the edge detection means. You may comprise so that the digital signal to comprise may be identified and stored sequentially in the said predetermined time width unit.
The determining means may be configured to determine the type of the time code based on whether or not a plurality of the predetermined direction edges of the digital signal stored in the storage means exist within a predetermined time. Good.

Further, the determination means determines the type of the time code based on whether or not the number of cases where the start of each second of the digital signal stored in the storage means is not the predetermined direction edge is greater than a predetermined value. You may comprise so that it may discriminate | determine.
Further, the determining means is configured to determine the type of the time code based on whether or not the digital signal stored in the storage means has a total pulse width of a predetermined level at a predetermined time larger than a predetermined value. May be.

Further, the storage means may be configured to identify and sequentially store digital signals constituting the time code by one type of predetermined time width unit.
The storage means may be configured to identify and sequentially store digital signals constituting the time code in a plurality of predetermined time width units.

  According to the present invention, since there is no need to designate a receiving station, the operation is simplified. In addition, since the time code reception time can be shortened, it is possible to reduce the power consumption caused by the reception operation.

  The radio timepiece according to the embodiment of the present invention will be described below. Since the standard radio wave frequency and time code format are determined in each country as described above, the radio timepiece must be compatible with the standard radio wave (frequency and time code format) to be received. . In the present embodiment, radio waves corresponding to standard radio waves in Japan (identification code: JJY), the United States (identification code: WWVB), and the United Kingdom (identification code: MSF) having the same frequency and different time codes. The watch will be described.

FIG. 1 is a block diagram of a radio timepiece according to an embodiment of the present invention.
In FIG. 1, a radio timepiece is constituted by an antenna 101 constituted by an antenna coil, a receiving circuit 102 for extracting and outputting a time code contained in a standard radio signal received by the antenna 101, and a central processing unit (CPU). A control circuit 103 that controls each component of the timepiece and the entire control, a display unit 104 that is configured by a liquid crystal display device or the like and displays the current time, etc., and a program and time code executed by the control circuit 103 A memory (random access memory: RAM) 105 as storage means for storing various data such as a digital signal to be stored, and an operation unit 106 as operation means. The antenna 101 and the receiving circuit 102 constitute a receiving means, and the control circuit 103 constitutes a control means, a discriminating means, and a correcting means.

2 to 5 are flowcharts showing processing of the radio timepiece of FIG. 1, and mainly show processing performed by the control circuit 103 executing a program stored in advance in the memory 105.
FIG. 6 is a signal waveform diagram showing an operation when a time code is detected from a received standard radio wave in this embodiment. A digital signal constituting the time code is converted into one type of predetermined time width unit (FIG. 6). Shows a waveform diagram for detection in units of 0.1 sec.
Hereinafter, the operation of the radio timepiece according to the embodiment of the present invention will be described with reference to FIGS.

In the radio timepiece, when the time stored in advance in the memory 105 has arrived, or when the user instructs time adjustment processing by operating the operation unit 106, the control circuit 103 detects this and detects the time. Start the correction process.
When the time adjustment process is started, the control circuit 103 supplies power to the reception circuit 102 to start the operation of the reception circuit 102. The receiving circuit 102 receives the standard radio wave by the antenna 101, extracts the time code included in the standard radio wave, and outputs it.

  The control circuit 103 detects a predetermined direction edge (rising edge which is a first direction edge in the present embodiment) of the digital signal constituting the received time code (step S201), and uses the rising edge as a reference. The digital signal is identified by one type of predetermined time width unit (in this embodiment, as shown in FIG. 6, 100 msec unit), and is sequentially stored and stored in the memory 105 as data (step S202). Here, step S201 constitutes an edge detection means.

  Next, the control circuit 103 determines whether or not a predetermined time T1 (for example, about 30 seconds) has elapsed (step S203), and when determining that the predetermined time T1 has elapsed, Of the digital signals stored in the memory 105, the pulse width times of a predetermined level (high level in the present embodiment) at a predetermined time are totaled, and it is determined whether or not the total time is larger than the predetermined time T ( Step S205).

  If the control circuit 103 determines in step S205 that the total time of the high level is smaller than the predetermined time T, the control circuit 103 determines that the received time code is a British time code (MSF) (FIG. 3 (step S217), a digital signal (signal P in FIG. 10) representing the MSF frame start position is searched from the digital signal stored in the memory 105 and the digital signal being received (step S218). Here, step S217 constitutes a discrimination means.

Next, when the control circuit 103 detects the signal P indicating the start position of the frame of the MSF (step S219), the control circuit 103 decodes the received digital signal data from the start position of the frame and performs an operation of determining the current time. When the current time can be determined, the power supply of the receiving circuit 102 is shut off and the receiving operation of the receiving circuit 102 is ended (step S220).
Next, the control circuit 103 determines whether or not the current time has been determined in step S220, that is, whether or not the reception operation has ended (step S221).

If the control circuit 103 determines in step S221 that the reception operation has not yet been completed, the control circuit 103 continues the reception operation of the standard radio wave by the reception circuit 105 and decodes the received time code as an MSF. The current time determination operation is performed, and when the current time can be determined, the reception operation of the reception circuit 102 is terminated (step S222).
Next, the control circuit 103 determines whether or not the current time has been determined in step S222, that is, whether or not the reception operation has been completed. If the reception operation has been completed, the control circuit 103 counts time (not shown). The time is corrected to the current time corresponding to the determined time code, and the time is displayed on the display unit 104, and the time correction process is terminated (step S223). Here, step S223 constitutes correction means.

  When the control circuit 103 cannot detect the signal P indicating the start position of the frame in step S219, the control circuit 103 proceeds to step S222 and performs the processing. If the control circuit 103 determines in step 221 that the current time has been determined in step S220, that is, if it is determined that the reception operation has been completed, the control circuit 103 ends the processing. If the control circuit 103 determines in step S223 that the current time could not be determined in step S222, that is, if it is determined that the reception operation has not ended, the control circuit 103 returns to step S222 to perform the processing.

On the other hand, when the control circuit 103 determines in step S205 that the total value of the time at the high level is greater than the predetermined time T, the received time code is not a British time code (MSF) (ie, It is determined that the received time code is JJY or WWVB).
Next, the control circuit 103 uses a plurality of (two in this embodiment) predetermined direction edges (this embodiment) from a digital signal stored in the memory 105 at a predetermined time (1 second in this embodiment). Then, the number A in which rising edges) are present is counted (step S207). When the received signal is WWVB, there are no more than one rising edge per second, but in the case of JJY, for example, as shown in FIG. 8B, digital signals “0” and “1”. Continuously received, there will be two rising edges per second. Therefore, if the reception state is normal, it can be determined in step S207 that the received signal is not WWVB but JJY if the number A in which a plurality of predetermined direction edges exist in one second is 1 or more. Become.

  Next, the control circuit 103 determines from the digital signal stored in the memory 105 that the start of a predetermined time (1 second in this embodiment) does not become a predetermined direction edge (rising edge in this embodiment). B is counted (step S208). In the case of WWVB, the start of each second (that is, each digital signal) is a rising edge, whereas in the case of JJY, the start of each second is not a rising edge but a falling edge. Therefore, if the reception state is normal, it can be determined in step S208 that the received signal is not WWVB but JJY if the number B that is not a rising edge at the start of each second is 1 or more. become.

Next, the control circuit 103 determines whether the number A is larger than a predetermined value α (for example, 5 to 7) and / or whether the number B is larger than a predetermined value β (for example, 3 to 5). Is determined (step S209). Here, when the reception state is ideal and is not affected by noise or the like, as described above, α and β may each be 1, but the reception state may not be good. In addition, the values of α and β are set to positive integer values larger than 1.
In step S209, the control circuit 103 may determine WWVB or JJY when both α and β satisfy the above condition, or either α or β satisfies the above condition. In such a case, it may be determined as WWVB or JJY. In the latter case, step S207 or step S208 can be omitted.

In step S209, the control circuit 103 determines that the received time code is WWVB or JJY based on the magnitude relationship between A and α and / or the magnitude relationship between B and β as described above. Here, if the control circuit 103 determines in step S209 that A is not greater than α and / or B is not greater than β, it determines that the received time code data is WWVB (step S210). Here, step S210 constitutes a discrimination means.
Next, the control circuit 103 searches the digital signal stored in the memory 105 for a digital signal (for example, a signal PP in which two signals P in FIG. 9 are continuous) representing the start position of the WWVB frame (step S211). ).

Next, when the control circuit 103 detects the signal PP indicating the start position of the WWVB frame (step S212), the control circuit 103 decodes the digital signal data stored in the memory 105 from the start position of the frame to obtain the current time. When the current time can be determined, the receiving operation of the receiving circuit 102 is terminated (step S213).
Next, the control circuit 103 determines whether or not the current time has been determined in step S213, that is, whether or not the reception operation has ended (step S214).

  If the control circuit 103 determines in step S214 that the reception operation has not yet ended, the control circuit 103 continues the reception operation of the standard radio wave by the reception circuit 105 and decodes the received time code as WWFB. The current time determination operation is performed, and when the current time can be determined, the power supply of the reception circuit 102 is shut off and the reception operation is terminated (step S215).

Next, the control circuit 103 determines whether or not the current time has been determined in step S215, that is, whether or not the reception operation has been completed. If the reception operation has been completed, the control circuit 103 sets the time measured by the time measuring means. The time is corrected to the current time corresponding to the time code and the time is displayed on the display unit 104, and the time correction process is terminated (step S216). Step S216 constitutes correction means.
If the control circuit 103 cannot detect the signal PP indicating the start position of the frame in step S212, the control circuit 103 proceeds to step S215 and performs the processing.

  If the control circuit 103 determines in step 214 that the current time has been determined in step S213, that is, if it is determined that the reception operation has ended, the control circuit 103 ends the processing. If the control circuit 103 determines in step S216 that the current time could not be determined in step S215, that is, if it is determined that the reception operation has not ended, the control circuit 103 returns to step S215 to perform the processing.

On the other hand, if the control circuit 103 determines in step S209 that A is greater than α and / or B is greater than β, it determines that the received time code data is JJY (step S224). Here, step S224 constitutes a discrimination means.
Next, the control circuit 103 sets the edge of the digital signal data stored in the memory 102 in the direction different from the predetermined direction edge (the falling edge which is the second direction edge in the present embodiment) as the start position of each second. (Step S225). As a result, the digital signal stored in the memory 102 can be recognized as a JJY time code.

Next, the control circuit 103 searches for a digital signal (for example, a signal PP in which two signals P in FIG. 8 are continuous) representing the start position of the JJY frame from the converted digital signal (step S226).
Next, when the control circuit 103 detects the signal PP indicating the start position of the frame of JJY (step S227), the control circuit 103 decodes the received digital signal data from the start position of the frame and performs an operation of determining the current time. When the current time can be determined, the power supply to the receiving circuit 102 is cut off and the receiving operation is terminated (step S228).

Next, the control circuit 103 determines whether or not the current time has been determined in step S228, that is, whether or not the reception operation has ended (step S229).
If the control circuit 103 determines in step S229 that the reception operation has not yet been completed, the control circuit 103 continues to store the standard radio wave reception operation by the reception circuit 105 in the memory 105, and receives the received time code. Is decoded as JJY to determine the current time. When the current time can be determined, the receiving operation of the receiving circuit 102 is terminated (step S230).
Next, the control circuit 103 determines whether or not the current time has been determined in step S230, that is, whether or not the reception operation has been completed. If the reception operation has been completed, the control circuit 103 sets the time measured by the time measuring means. The time is corrected to the current time corresponding to the time code and the time is displayed on the display unit 104, and the time correction process is terminated (step S231). Here, step S231 constitutes correction means.

  When the control circuit 103 cannot detect the signal PP indicating the start position of the frame in step S227, the control circuit 103 proceeds to step S230 and performs the processing. If the control circuit 103 determines in step 229 that the current time has been determined in step S228, that is, if it is determined that the reception operation has been completed, the control circuit 103 ends the processing. If the control circuit 103 determines in step S231 that the current time could not be determined in step S230, that is, if it is determined that the reception operation has not ended, the control circuit 103 returns to step S230 to perform the processing.

  In the present embodiment, when detecting a digital signal constituting a time code, the maximum time width capable of detecting the time code to be received is used as the predetermined unit time, and the digital signal in the predetermined unit time unit is used. The signal is detected. In the present embodiment, three types of MSF, WWVB, and JJY are assumed as time codes to be received, and the minimum time width of the high modulation unit and the low modulation unit in the digital signal is 100 msec. One kind of predetermined unit time of 100 msec is used as the predetermined unit time.

  However, for example, when two types of WWVB and JJY are assumed as reception time codes, the time code can be configured to be detected in a plurality of types of predetermined time units. For example, digital signals with WWVB and JJY time codes have a minimum time width of 200 msec for both the high modulation unit and the low modulation unit, so the digital signal identification timing is as shown in FIG. The part and the end part may be 200 msec each, and the interval between them may be divided every 100 msec. In this case, compared to the example of FIG. 6, the number of bits representing a digital signal can be reduced, and a memory 105 having a small capacity can be used.

  As described above, the radio timepiece according to the embodiment of the present invention receives a time code including information on the current time by radio wave, and corrects the time measured by the time measuring means to a time corresponding to the received time code. In the radio timepiece, the antenna 101 and the receiving circuit 102 for receiving the time code by radio wave, the memory 105 for identifying and sequentially storing the digital signals constituting the time code in units of a predetermined time width, and the memory 105 A discriminating unit for discriminating the type of the time code based on a digital signal; and analyzing the received time code based on the type of the time code discriminated by the discriminating unit to discriminate a current time; Correction means for correcting the time.

  Therefore, it is not necessary to specify the receiving station, and the operation is simplified. In addition, since the type of time code is determined based on the number of rising edges within a predetermined time, even when the radio wave condition is bad and it is difficult to receive an accurate time code for a long time, the time code It becomes possible to accurately determine the type. Accordingly, since it is possible to accurately determine the time code without receiving it for a long time, the reception time can be shortened, and the power consumption caused by the reception operation can be reduced.

In the above embodiment, examples have been described in Japan, the United States, and the United Kingdom. However, the present invention can be applied not only to the above-described countries but also to radio timepieces that are used in a plurality of countries using the same frequency and different time codes. It is.
Further, as the reference edge for detecting the digital signal, a rising edge or a falling edge can be appropriately selected according to the format of the time code to be received.

  The present invention is not limited to Japan, the United States, the United Kingdom, and the like, and can also be applied to a radio clock used in a plurality of countries that use different time codes with the same standard radio frequency. Further, it can be applied to both an analog radio timepiece and a digital radio timepiece.

1 is a block diagram of a radio timepiece according to an embodiment of the present invention. It is a flowchart which shows the process of the radio timepiece which concerns on embodiment of this invention. It is a flowchart which shows the process of the radio timepiece which concerns on embodiment of this invention. It is a flowchart which shows the process of the radio timepiece which concerns on embodiment of this invention. It is a flowchart which shows the process of the radio timepiece which concerns on embodiment of this invention. It is a signal waveform diagram which shows operation | movement of the radio timepiece which concerns on embodiment of this invention. It is a signal waveform diagram which shows operation | movement of the radio timepiece which concerns on other embodiment of this invention. It is a signal waveform diagram of a digital signal constituting a Japanese time code. It is a signal waveform diagram of a digital signal constituting a time code in the United States. It is a signal wave form diagram of a digital signal which constitutes a British time code. It is a signal waveform diagram which shows a part of term code in Japan, the United States, and the United Kingdom. It is a signal waveform diagram which shows a part of term code in Japan, the United States, and the United Kingdom.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Antenna which comprises receiving means ... Receiving circuit 103 which constitutes receiving means ... Control circuit, discriminating means, correcting means, control circuit constituting edge detecting means 104 ... Display means Display unit 105... Memory (RAM) as storage means
106: Operation unit as operation means

Claims (7)

In a radio timepiece that receives a time code including information on the current time by radio wave, and corrects the time measured by the time measuring means to a time corresponding to the received time code,
Receiving means for receiving the time code by radio waves;
Storage means for identifying and sequentially storing digital signals constituting the time code in predetermined time width units;
Determining means for determining the type of the time code based on the digital signal stored in the storage means;
A radio timepiece comprising: a correcting unit that analyzes the received time code based on the type of the time code determined by the determining unit to determine a current time and corrects the time measured by the time measuring unit. Edge detection means for detecting a predetermined direction edge of the digital signal constituting the received time code;
2. The storage means according to claim 1, wherein the digital signals constituting the time code are identified and sequentially stored in units of the predetermined time width with reference to a predetermined direction edge detected by the edge detection means. Radio clock.   2. The time code type according to claim 1, wherein the determining means determines the type of the time code based on whether or not a plurality of the predetermined direction edges of the digital signal stored in the storage means exist within a predetermined time. Or the radio timepiece of 2.   The discriminating unit discriminates the type of the time code based on whether or not the number of cases where the start of each second of the digital signal stored in the storage unit is not the predetermined direction edge is larger than a predetermined value. The radio timepiece according to any one of claims 1 to 3.   The discriminating unit discriminates the type of the time code based on whether or not a digital signal stored in the storage unit has a total pulse width of a predetermined level at a predetermined time larger than a predetermined value. Item 5. The radio timepiece according to any one of Items 1 to 4.   6. The radio timepiece according to claim 1, wherein the storage means sequentially stores the digital signals constituting the time code by identifying one type of predetermined time width unit.   6. The radio timepiece according to claim 1, wherein the storage means stores the digital signals constituting the time code in a plurality of predetermined time width units and sequentially stores them.

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