JP2019117080A - Electronic timepiece and method for controlling electronic timepiece - Google Patents

Abstract

To increase the accuracy of the internal time of the electronic timepiece.SOLUTION: A controller 22 controls an oscillation circuit 23 according to the frequency of the carrier wave of a standard electric wave and the frequency fof a clock signal so that the frequency fof the clock signal becomes closer to a reference frequency f0. Since the controller 22 controls the frequency fof the clock signal, using the carrier wave of the standard electric wave with its frequency being managed accurately, the accuracy of the internal time can be increased.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electronic watch and a control method of the electronic watch.

  Conventionally, as a technique for adjusting the internal time of an electronic watch to an accurate time, a configuration for receiving standard radio waves is known. For example, Patent Document 1 discloses an electronic watch that receives a standard radio wave. This electronic clock demodulates the received standard radio wave to acquire a TCO (Time Code Out: time code output) signal, extracts date information and time information from the TCO signal, and matches the internal time to an accurate time. to correct.

JP, 2016-161467, A

  The radio wave correction watch of Patent Document 1 operates a reception unit that receives a standard radio wave, a crystal oscillator 431 that generates a reference signal, a time counter 471 that clocks an internal time based on the reference signal, and a reception unit. It has a scheduled reception control unit 472 that performs reception processing, and a time correction unit 474 that corrects the internal time. The scheduled reception control unit 472 executes the reception process at the first time to acquire the first reception time data, compares the acquired first reception time data with the internal time, and if the time difference is equal to or more than the first threshold, The reception process is performed at a second time different from the first time to acquire second reception time data. However, even if the internal time is corrected using the TCO signal acquired from the standard radio wave, when the frequency accuracy of the clock signal of the crystal oscillator 431 is low, an error of time due to the clock signal is accumulated in the internal time There was a problem of

  An object of the present invention is to improve the accuracy of the internal time of an electronic watch.

  In an electronic watch according to a preferred aspect (first aspect) of the present invention, a reception unit for receiving a standard radio wave, an oscillation circuit for generating a clock signal used to measure an internal time, and the reception unit receive A control unit that controls the oscillation circuit such that the frequency of the clock signal approaches a reference frequency determined according to the frequency of the carrier wave of the standard radio wave based on the frequency of the carrier wave of the standard radio wave and the frequency of the clock signal And.

  According to the above aspect, since the frequency of the clock signal is controlled using the carrier wave of the standard radio wave managed with high accuracy, the accuracy of the internal time can be improved.

  In a preferred example of the first aspect (second aspect), the control unit controls the oscillation circuit based on a specific part that specifies a difference between the reference frequency and the frequency of the clock signal, and the difference. And a correction unit that corrects the frequency of the clock signal to approach the reference frequency.

  According to the above aspect, the frequency of the clock signal can be made close to the reference frequency by controlling the oscillation circuit such that the specified difference is cancelled.

  In a preferred example of the second aspect (third aspect), the specification unit specifies the difference based on a reference wave generated from a carrier wave of the standard radio wave and the clock signal.

  According to the above aspect, it is possible to obtain the reference wave of high accuracy by generating the reference wave from the carrier wave of the standard radio wave of high accuracy.

  In the preferable example (4th aspect) of the 3rd aspect, the said specification part is the 1st phase difference between the said reference wave and the said clock signal in 1st time, the said reference wave in the 2nd time, and the said clock signal The difference is identified based on a second phase difference between the first and second times and the time from the first time to the second time.

  Generally, as a method of obtaining the difference between two frequencies, counting the number of periods of the other frequency within an integer multiple of one period of one frequency as a reference, and identifying the other frequency There is a so-called counter system that specifies the difference between one frequency and the other frequency. Therefore, in the counter method, it takes an integral multiple of one period to obtain information necessary to specify the other frequency. On the other hand, according to the above aspect, it is possible to obtain the first phase difference and the second phase difference used to specify the difference during the time from the first time to the second time. By setting the time from the first time to the second time as the time until one cycle of the reference frequency elapses, it is possible to specify the difference in a short time as compared with the counter system.

  In a preferable example (fifth aspect) of the second to fourth aspects, the correction unit outputs a control voltage based on the difference, and the oscillation circuit oscillates a clock signal having a frequency according to the control voltage. Do.

  According to the above aspect, the control voltage based on the difference can be input to the oscillation circuit, the frequency of the clock signal can be corrected, and the accuracy of the internal time can be improved.

  In a preferable example (sixth aspect) of the second to fifth aspects, the oscillation circuit oscillates a clock signal of a frequency according to a control voltage, and the accumulated operation time of the oscillation circuit and the predetermined control voltage are oscillated. And a storage unit for storing accumulated operation time characteristic information related to a frequency of a clock signal generated when input to a circuit, wherein the control unit refers to the accumulated operation time characteristic information and accumulates the oscillation circuit. And a control voltage generation unit that specifies an error in the frequency of the clock signal according to the operation time and generates the control voltage so as to cancel the error, and the correction unit determines the difference and the difference The accumulated operation time characteristic information is updated based on the accumulated operation time of the oscillation circuit to correct the frequency of the clock signal.

  According to the above aspect, even when the standard radio wave is not received when a certain amount of time has elapsed after specifying the difference, the frequency of the clock signal is corrected using the updated cumulative operation characteristic information. It becomes possible.

  In a preferable example (a seventh aspect) of the second to fourth aspects, the oscillation circuit oscillates a clock signal of a frequency according to a control voltage, and a temperature and a predetermined voltage which can be taken by the oscillation circuit are the oscillation circuit. And a storage unit for storing temperature characteristic information related to the frequency of the clock signal generated when input to the clock signal, the control unit refers to the temperature characteristic information, and a clock signal according to the temperature of the oscillation circuit And a control voltage generation unit that generates the control voltage so as to cancel the error, and the correction unit determines the difference and the temperature of the oscillation circuit at the time when the difference is specified. Based on the temperature characteristic information, the frequency of the clock signal is corrected.

  According to the above aspect, it is possible to correct the frequency of the clock signal using the updated temperature characteristic information even when the standard radio wave is not received at a temperature different from the temperature at the time of specifying the difference. become.

    In a preferable example (eighth aspect) of the second aspect to the seventh aspect, the internal time is set based on the difference and the number of clock signals since setting the internal time based on a standard radio wave. Includes an internal time correction unit to correct.

  According to the above aspect, when receiving the standard radio wave, it is possible to reduce the load applied to the correction of the internal time as compared with the case where the internal time is always corrected using the TCO signal. In order to obtain the TCO signal, it is necessary to demodulate the standard radio wave. However, when correcting the internal time using the carrier wave of the standard radio wave, it is not necessary to demodulate the standard radio wave. Therefore, by correcting the internal time using the difference between the reference frequency and the frequency of the clock signal, when the standard radio wave is received, the internal time is corrected as compared to always correcting the internal time using the TCO signal. The load on the correction can be reduced and completed in a short time.

  A control method of an electronic watch according to a preferred aspect (ninth aspect) of the present invention is an electronic watch including a receiving unit for receiving a standard radio wave, and an oscillation circuit for generating a clock signal used to measure an internal time. The control method, wherein the electronic watch is determined according to the frequency of the carrier wave of the standard wave based on the frequency of the carrier wave of the standard wave received by the receiving unit and the frequency of the clock signal. The oscillator circuit is controlled so that the frequency of the clock signal approaches.

  According to the above aspect, since the frequency of the clock signal is controlled using the carrier wave of the standard radio wave managed with high accuracy, the accuracy of the internal time can be improved.

  In a preferable example (tenth aspect) of the ninth aspect, the electronic timepiece specifies a difference between the reference frequency and the frequency of the clock signal, and controls the oscillation circuit based on the difference to control the clock signal. Are corrected so as to approach the reference frequency.

  According to the above aspect, the frequency of the clock signal can be made close to the reference frequency by controlling the oscillation circuit such that the specified difference is cancelled.

  In a preferable example of the tenth aspect (an eleventh aspect), the electronic watch specifies the difference based on a reference wave generated from a carrier wave of the standard radio wave and the clock signal.

  According to the above aspect, it is possible to obtain the reference wave of high accuracy by generating the reference wave from the carrier wave of the standard radio wave of high accuracy.

  In a preferred example of an eleventh aspect (a twelfth aspect), the electronic watch includes a first phase difference between the reference wave and the clock signal at a first time, the reference wave at a second time, and the clock signal. The difference is identified based on a second phase difference between the first and second times and the time from the first time to the second time.

  According to the above aspect, it is possible to obtain the first phase difference and the second phase difference used to specify the difference at the time from the first time to the second time. By setting the time from the first time to the second time as the time until one cycle of the reference frequency elapses, it is possible to specify the difference in a short time as compared with the counter system.

  In a preferable example (a thirteenth aspect) of the tenth aspect to the twelfth aspect, the electronic watch outputs a control voltage based on the difference, and the oscillation circuit oscillates a clock signal of a frequency according to the control voltage. Do.

  According to the above aspect, the control voltage based on the difference can be input to the oscillation circuit, the frequency of the clock signal can be corrected, and the accuracy of the internal time can be improved.

  In a preferable example (fourteenth aspect) of the tenth aspect to the twelfth aspect, the oscillation circuit oscillates a clock signal of a frequency according to a control voltage, and the electronic watch is predetermined with an accumulated operation time of the oscillation circuit. A storage unit for storing accumulated operation time characteristic information related to a frequency of a clock signal generated when a control voltage is input to the oscillation circuit, the electronic watch referring to the accumulated operation time characteristic information An error in the frequency of the clock signal according to the accumulated operation time of the oscillator circuit is specified, the control voltage is generated so as to cancel the error, and the difference and the difference are identified. The accumulated operation time characteristic information is updated based on time to correct the frequency of the clock signal.

  According to the above aspect, even when the standard radio wave is not received when a certain amount of time has elapsed after specifying the difference, the frequency of the clock signal is corrected using the updated cumulative operation characteristic information. It becomes possible.

  In a preferable example (fifteenth aspect) of the tenth aspect to the twelfth aspect, the oscillation circuit oscillates a clock signal having a frequency according to a control voltage, and the electronic timepiece can obtain a predetermined temperature and a temperature that the oscillation circuit can take. The electronic timepiece includes a storage unit storing temperature characteristic information related to a frequency of a clock signal generated when a voltage is input to the oscillation circuit, and the electronic watch refers to the temperature characteristic information to determine a temperature of the oscillation circuit. The temperature characteristic information is determined based on the difference between the frequency and the temperature of the oscillation circuit at the time of specifying the difference by specifying the error of the frequency of the corresponding clock signal and generating the control voltage to cancel the error. Update to correct the frequency of the clock signal.

  According to the above aspect, it is possible to correct the frequency of the clock signal using the updated temperature characteristic information even when the standard radio wave is not received at a temperature different from the temperature at the time of specifying the difference. become.

  In a preferable example (sixteenth aspect) of the tenth aspect through the fifteenth aspect, the electronic timepiece sets the difference and the number of clock signals since setting the internal time based on a standard radio wave. , Correct the internal time.

  According to the above aspect, when receiving the standard radio wave, it is possible to reduce the load applied to the correction of the internal time as compared with the case where the internal time is always corrected using the TCO signal. In order to obtain the TCO signal, it is necessary to demodulate the standard radio wave. However, when correcting the internal time using the carrier wave of the standard radio wave, it is not necessary to demodulate the standard radio wave. Therefore, by correcting the internal time using the difference between the reference frequency and the frequency of the clock signal, when the standard radio wave is received, the internal time is corrected as compared to always correcting the internal time using the TCO signal. The load on the correction can be reduced and completed in a short time.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view of the electronic timepiece 1 in 1st Embodiment. BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the electronic timepiece 1 in 1st Embodiment. Diagram showing the relationship of _{I t1, Q t1, I t2} , and _{Q t2.} The figure which shows the flowchart of a frequency correction process. The block diagram of the electronic timepiece 1 in 2nd Embodiment. The figure which shows the example of an update of the accumulation operation time characteristic information 251. FIG. The block diagram of the electronic timepiece 1 in 3rd Embodiment. The figure which shows the example of an update of the temperature characteristic information 252. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, in each drawing, the dimensions and the scale of each part are appropriately changed from the actual ones. Further, the embodiment described below is a preferable specific example of the present invention, and therefore, various technically preferable limitations are added, but the scope of the present invention particularly limits the present invention in the following description. As long as there is no statement of purport, it is not limited to these forms.

A. First Embodiment An electronic timepiece 1 according to a first embodiment will be described below.

A. 1. Overview of Electronic Watch 1 According to First Embodiment FIG. 1 is a perspective view of the electronic watch 1 according to the first embodiment. The electronic timepiece 1 uses the movement of electrons to indicate time. As shown in FIG. 1, the electronic watch 1 is a watch. The electronic timepiece 1 includes a band portion 2, a button 4-1, a button 4-2, a button 4-3, a case portion 6 and a time display portion 10. The time display unit 10 includes an hour hand 11, a minute hand 12, and a second hand 13. The time display unit 10 indicates the time by the direction of each of the hour hand 11, the minute hand 12, and the second hand 13.

  In FIG. 2, the block diagram of the electronic timepiece 1 in 1st Embodiment is shown. The electronic timepiece 1 includes a storage unit 20, a reception unit 21, a control unit 22, an oscillation circuit 23, a processing unit 24, and a time display unit 10. The control unit 22 is an electronic circuit that executes a process designed by a designer, such as a field programmable gate array (FPGA) or an application specific IC (ASIC).

  The storage unit 20 is a computer readable / writable non-volatile storage medium. The storage unit 20 is, for example, a flash memory. The storage unit 20 is not limited to the flash memory and can be appropriately changed. The storage unit 20 stores, for example, a program that the processing unit 24 executes.

The receiving unit 21 receives a standard radio wave. Standard radio waves are transmitted as a national standard of time and frequency. There are several types of standard radio waves, depending on the country where the standard radio waves are transmitted, and JJY (registered trademark) transmitted in Japan, WWVB transmitted in the United States, DCF 77 in Germany, MSF in the United Kingdom, or BPC in China Etc. In the following description, the standard radio wave is JJY, and the carrier frequency of JJY is 40 kHz. The carrier wave of the standard radio wave is generated based on a national standard such as a cesium atomic clock, and is a high accuracy signal with an error of ± 10 ⁻¹² .

A. 2. Time Setting by Standard Radio Wave The receiving unit 21 receives a standard radio wave. The receiving unit 21 outputs the TCO signal obtained by demodulating the received standard radio wave to the processing unit 24. The TCO signal is a signal obtained by demodulating a standard radio wave from when the second of the national standard time is 0 seconds to 1 minute. Further, the receiving unit 21 outputs the received standard radio wave itself to the control unit 22.

  The processing unit 24 is a computer such as a CPU (Central Processing Unit). The processing unit 24 controls the entire electronic timepiece 1. The processing unit 24 implements the TCO decoding unit 241, the internal time correction unit 242, and the internal time keeping unit 243 by reading and executing the program stored in the storage unit 20.

  The TCO decoding unit 241 extracts, from the TCO signal, a time code (time information) having date information, time information, and the like included in the TCO signal. Then, the TCO decoding unit 241 outputs the extracted time code to the internal time correction unit 242.

  The internal time correction unit 242 outputs the time code obtained from the TCO decoding unit 241 to the internal time keeping unit 243, and sets a value based on the time code in the counter of the internal time keeping unit 243. Thereby, the internal time is set.

  The internal timekeeping unit 243 measures the internal time using a 1 Hz signal obtained by dividing the clock signal generated by the oscillation circuit 23. Specifically, the internal timekeeping unit 243 has a second counter that counts seconds, a minute counter that counts minutes, and an hour counter that counts hours. The internal timekeeping unit 243 rotates the second hand 13 according to the value of the second counter, rotates the minute hand 12 according to the value of the minute counter, and rotates the hour hand 11 according to the value of the hour counter. Let Thus, the time display unit 10 displays the internal time.

A. 3. Correction of Frequency of Clock Signal Based on Standard Radio Wave and Clock Signal The oscillation circuit 23 generates a clock signal used to clock an internal time. The oscillation circuit 23 includes a quartz oscillator. The oscillation circuit 23 is, for example, a VCO (Voltage Controlled Oscillator) that oscillates a clock signal of a frequency according to the control voltage.

The control unit 22 controls the oscillation circuit 23 based on the frequency of the carrier wave of the standard radio wave received by the reception unit 21 and the frequency of the clock signal generated by the oscillation circuit 23 to set the frequency of the clock signal to the reference frequency f0. Control to approach. The reference frequency f0 is determined in accordance with the frequency of the carrier wave of the standard radio wave. In order to measure one second, the reference frequency f0 is preferably a frequency that is 1 Hz divided by a power of 2, for example, 32.768 kHz. Hereinafter, the reference frequency f0 is 32.768 kHz.
As described above, the frequency of the carrier wave of the standard radio wave has very few errors. Therefore, when the frequency of the carrier wave of the standard radio wave is fc, the frequency obtained by multiplying the frequency of the carrier wave of the standard radio wave by f0 / fc can be regarded as the reference frequency f0. Hereinafter, a signal whose frequency is the reference frequency f0 is referred to as a "reference wave".

More specifically, the control method of the oscillation circuit 23 by the control unit 22 will be described. Control unit 22 includes an identification unit 221, a correction unit 222, and a control voltage generation unit 223. The identifying unit 221 identifies the difference Δfv between the reference frequency f0 and the frequency f _{VCO of the} clock signal. Hereinafter, the difference between the reference frequency f0 and the frequency f _{VCO of the} clock signal is referred to as a "frequency difference".

In order to specify the frequency difference Δfv, the specification unit 221 generates a reference wave from the carrier wave of the standard radio wave. Specifically, the specifying unit 221 uses a numerically controlled oscillator (NCO) as an arithmetic unit that performs numerical calculation for converting the frequency. Then, the specifying unit 221 applies the NCO calculation to the carrier wave of the standard radio wave, and converts it into a reference wave. The NCO can be converted to a signal of any frequency. In the present embodiment, as described above, since the carrier wave frequency of the standard radio wave is 40 kHz, the carrier wave frequency of the standard radio wave is multiplied by f0 / (40 × 10 ³ ) to obtain the carrier wave of the standard radio wave. It is possible to convert to waves.
Next, the specifying unit 221 determines the first phase difference between the reference wave and the clock signal at time t1 (an example of “first time”), the reference wave and the clock at time t2 (an example of “second time”). The frequency difference Δfv is specified based on the second phase difference from the signal and the time PDI from time t1 to time t2. The time PDI is preferably less than one cycle of the reference frequency f0. Specifically, the specifying unit 221 combines the reference wave and the clock signal and combines the combined signal (referred to as an I signal) and a signal (referred to as a Q signal) obtained by delaying the I signal by π / 2. Generate Next, the specification unit 221, the I and Q signals, the value _{Q t1} value _{I t1} and Q signals I signal at time t1 has elapsed time PDI from the measurement start time, and, more time PDI from time t1 in elapsed time t2 to determine the value _{Q t2} value _{I t2} and Q signals of the I signal.

Figure 3 _shows a relationship between the _{I t1, Q t1, I t2} , and _{Q t2.} As shown in FIG. 3, the I signal and the Q signal indicate the phase difference between the reference wave and the clock signal as a complex number. The phase change amount Δφ _t12 of the first phase difference to the second phase difference is expressed by the following equation (1).

Δφ _t12 = φ _t2 −φ _t1 (1)

φ _t1 is a first phase difference. φ _t2 is a second phase difference. φ _t1 = I _t1 + jQ _t1 and φ _t2 = I _t2 + jQ _t2 j is an imaginary unit. From trigonometry, the equation (1) is converted into the following equation (2) using X = Cross / Dot.

Δφ _t12 = tan ⁻¹ (X) (2)

_Here, Cross ₌ a _{I t1 * Q t2 -I t2 *} Q t1, a _{Dot = I t1 * I t2 +} Q t1 * Q t2. Further, Δφ _t12 is expressed by the following equation (3).

Δφ _t12 + 2nπ = 2π * PDI * f _VCO (3)

n is an integer of 0 or more. Here, the time PDI in which n = 0 is set to 0 <Δφ _t12 <2π, and is obtained as follows using the equation (3).

0 <Δφ _t12 <2π
⇔ 0 <2π * PDI * f _VCO <2π
⇔ 0 <PDI <1 / f _VCO

The frequency f _{VCO of the} clock signal has a value close to the reference frequency f0. Therefore, the time PDI is less than one cycle of the reference frequency f0 and can be approximately n = 0. However, in the case where the frequency f _{VCO of the} clock signal becomes larger than the reference frequency f0, n may become 1 or more if the time PDI is close to one cycle of the reference frequency f0. Therefore, the time _PDI, the difference _{I t1} and _{I t2,} and the difference between the _{Q t1} and _{Q t2} are sufficiently measured, and it is preferably sufficiently smaller than the one period of the reference frequency f0. By setting n = 0, the calculation for specifying the frequency difference Δfv is simplified, and the time required for the calculation is shortened. If n = 0, the frequency f _{VCO of the} clock signal is expressed by the following equation (4) using the equations (2) and (3).

f _VCO = tan ⁻¹ (X) / (PDI * 2π) (4)

Then, from the frequency difference Δfv = the frequency f _{VCO of the} clock signal−the reference frequency f0, the specifying unit 221 specifies the frequency difference Δfv using the equation (4).

The explanation is returned to FIG.
The correction unit 222 controls the oscillation circuit 23 based on the frequency difference Δfv to correct the frequency f _{VCO of the} clock signal so as to approach the reference frequency f0. More specifically, the correction unit 222 corrects the frequency of the clock signal by controlling the oscillation circuit 23 such that a voltage based on the frequency difference Δfv is input to the oscillation circuit 23. For example, the correction unit 222 supplies, to the control voltage generation unit 223, data indicating a voltage at which the frequency difference Δfv is canceled. The control voltage generation unit 223 D / A converts the supplied data and outputs the control voltage indicated by the data to the oscillation circuit 23.
The voltage at which the frequency difference Δfv is canceled will be described more specifically. It is assumed that the oscillation circuit 23 to which the voltage V0 is input at the first timing oscillates the clock signal of the reference frequency f0, and the specification unit 221 specifies the frequency difference Δfv at the second timing. When the time from the first timing to the second timing is long, the frequency of the clock signal changes due to the temporal change of the oscillation circuit 23. The frequency of the clock signal also changes when the temperature of the first timing is different from the temperature of the second timing. In such a case, the correction unit 222 cancels the frequency difference Δfv at the second timing and notifies the control voltage generation unit 223 of data in which the frequency of the clock signal is the reference frequency f0. For example, when the magnitude of the control voltage corresponding to the frequency difference Δfv is “−ΔV”, the control voltage generation unit 223 outputs data indicating “V0−ΔV”.

The internal time correction unit 242 corrects the internal time based on the frequency difference Δfv and the number of clock signals after setting the internal time based on the time information of the standard radio wave and until the present time. A specific correction method will be described. At the first timing, the receiving unit 21 receives the standard radio wave, and the TCO decoding unit 241 extracts a time code from the TCO signal obtained by demodulating the standard radio wave, and the internal time correction unit 242 sets the internal time according to the time code. Assume that. Further, at the first timing, the identifying unit 221 identifies the frequency difference Δfv0 based on the carrier wave of the standard radio wave received by the receiving unit 21 and the clock signal, and the correcting unit 222 determines the clock signal based on the frequency difference Δfv0. It is assumed that the frequency f _VCO is matched to the reference frequency f 0. Then, at the second timing after the first timing, the receiving unit 21 receives the standard radio wave again, and the specifying unit 221 specifies the frequency difference Δfv based on the carrier wave of the standard radio wave received by the receiving unit 21 and the clock signal. Assume that.

  When the internal time correction unit 242 receives the frequency difference Δfv, the number of clock signals from when the internal time is set to the current internal time at the first timing to the current time * (1 / (f0 + Δfv) −1 / Add f0). (1 / (f0 + .DELTA.fv) -1 / f0) indicates an error from an accurate time which occurs as one clock elapses. For example, when Δfv is a positive value, the time of one clock after the first timing is shortened, and the internal time is ahead of the correct time. Since 1 / (f0 + Δfv) -1 / f0 is a negative value, the internal time correction unit 242 reduces the value of the internal time, and the internal time can be made closer to the correct time.

  FIG. 4 shows a flowchart of the frequency correction process. The receiving unit 21 receives the standard radio wave (step S1). The identifying unit 221 applies the NCO operation to the carrier wave of the received standard wave to convert it into a reference wave (step S2).

Next, the specifying unit 221 acquires a clock signal of the oscillation circuit 23 (step S3). Then, the specification unit 221, the reference wave and the clock signal from the combined I and Q signals, detects the value _{Q t1} value _{I t1} and Q signals I signal at time t1 (step S4). Subsequently, the specifying unit 221 detects the value _{Q t2} value _{I t2} and Q signals I signal at time t2 (Step S5). Then, the specifying unit _221, based on the _{I t1, Q t1, I t2} , Q t2, and time PDI, using equation (4), to identify the frequency difference Derutafv (step S6).

The correction unit 222 corrects the frequency f _{VCO of the} clock signal based on the frequency difference Δfv (step S7). After completion of the process of step S7, the electronic timepiece 1 ends the series of processes.

A. 4. Effects of the First Embodiment As described above, the control unit 22 causes the frequency f _{VCO of the} clock signal to approach the reference frequency f 0 based on the frequency of the carrier wave of the standard radio wave and the frequency f _VCO of the clock signal. The oscillator circuit 23 is controlled. As described above, since the frequency f _{VCO of the} clock signal is controlled using the carrier wave of the standard radio wave managed with high accuracy, it is necessary to always receive the standard radio wave and correct the frequency f _{VCO of the} clock signal. Allows the internal time to continue to indicate the correct time. In addition, as described above, the TCO signal represents time information in one minute from the time when the second of the national standard time is 0 seconds to one minute. Therefore, if the standard radio wave can not be received in a part of the one minute period, the reception unit 21 can not demodulate the standard radio wave, and a TCO signal can not be obtained. As a result, the electronic timepiece 1 can not set the internal time. Therefore, the accuracy of the internal time decreases until the TCO signal is obtained. For example, the case where the reception intensity of the standard radio wave is temporarily reduced due to the influence of noise or the like is applicable.
However, in the first embodiment, even if the standard radio wave that could not be partially received, the internal time can be obtained by always correcting the frequency f _{VCO of the} clock signal using the carrier wave of the standard radio wave of the received portion. It is possible to continue to indicate the correct time. If the frequency f _{VCO of the} clock signal can be corrected to maintain the frequency difference Δfv / reference frequency f0 at ± 0.03 ppm (parts per million), it is possible to realize an annual difference of ± 1 second.

Further, the specification unit 221 specifies the frequency difference Δfv between the reference frequency f0 and the frequency of the clock signal, and the correction unit 222 controls the oscillation circuit 23 based on the frequency difference Δfv specified by the specification unit 221 to perform clocking. The frequency f _{VCO of the} signal is corrected so as to approach the reference frequency f0. The correction unit 222 can make the frequency f _VCO of the clock signal approach the reference frequency f 0 by controlling the oscillation circuit 23 such that the frequency difference Δf v is canceled.

  Further, the specifying unit 221 applies the NCO calculation to the carrier wave of the standard radio wave and converts it into a reference wave. This makes it possible to obtain a reference wave of high accuracy.

Further, the specifying unit 221 specifies the frequency difference Δfv based on the first phase difference, the second phase difference, and the time PDI. In the method of specifying the frequency difference Δfv based on the phase difference, it becomes possible to specify the frequency difference Δfv / reference frequency f0 with an accuracy of ± 10 ⁻⁷ in a short time of several tens of milliseconds to several seconds.
The fact that the method of specifying the frequency difference Δfv based on the phase difference can be performed in a short time will be described. In the method of specifying the frequency difference Δfv based on the phase difference, the time PDI * 2 is required since the measurement start time passes from the measurement start time to the time t2 in order to obtain X in the above-mentioned equation (2). Become. The time PDI is approximately 1 / reference frequency f0 at the longest, so the time PDI * 2 = 2 / (32.768 * 10 ³ ) = about 0.06 msec. From the above, in the method of specifying the frequency difference Δfv based on the phase difference, the time PDI * 2 is at most about 0.06 ms at most, and even if it takes time to calculate the equation (4), several tens of ms Can be performed in a short time, such as within a few seconds.
On the other hand, as a method of obtaining the difference between two frequencies, counting how many periods of the other frequency are within the time obtained by multiplying one period of one frequency as a reference by n (n is a natural number) There is a so-called counter system which specifies the frequency of the frequency of the signal of the frequency of the frequency of the However, in the counter method, a relatively long time is required to specify the frequency difference Δfv / reference frequency f0 with an accuracy of ppm. More specifically, the accuracy obtained by the counter method depends on the number of clocks of the other frequency in a fixed time. Therefore, in order to increase the accuracy in the counter system, it is necessary to increase n in order to increase the number of clocks of the other frequency, which is not practical at a low frequency such as 32.768 kHz. Thus, the method of specifying the frequency difference Δfv based on the phase difference can be performed in a shorter time than the counter method.
Since the frequency difference Δfv can be specified in a short time, it becomes easy to correct the internal time in a short time.

Further, the correction unit 222 corrects the frequency of the clock signal by controlling the oscillation circuit 23 such that a control voltage based on the frequency difference Δfv is input to the oscillation circuit 23. As a result, a voltage based on the frequency difference Δfv is input to the oscillation circuit 23, the frequency f _{VCO of the} clock signal can be corrected, and the internal time can continue to indicate the correct time.

Further, the internal time correction unit 242 corrects the internal time based on the frequency difference Δfv and the number of clock signals after setting the internal time based on the standard radio wave and until the present time. Thereby, the electronic timepiece 1 can reduce the load applied to the correction of the internal time, as compared with the case where the internal time is always set using the TCO signal when the standard radio wave is received. Specifically, in order to obtain the TCO signal, it is necessary to demodulate the standard radio wave, but when the internal time is corrected using the carrier wave of the standard radio wave, it is not necessary to demodulate the standard radio wave. Therefore, by correcting the internal time using the difference between the reference frequency and the frequency of the clock signal, when the standard radio wave is received, the internal time is corrected as compared to always correcting the internal time using the TCO signal. The load on the correction can be reduced and completed in a short time.
Further, in the case of setting the internal time using the TCO signal, in JJY, as described above, since the TCO signal is transmitted over one minute, it takes at least one minute or more to set the internal time. On the other hand, when the internal time is corrected using the frequency difference Δfv, the frequency difference Δfv can be specified in a short time of several tens of milliseconds to several seconds.

B. Second Embodiment Generally, desorption of dust to a quartz oscillator which occurs in the hermetically sealed container of the oscillation circuit 23, environmental change due to some outgassing, aging of adhesive used for the oscillation circuit 23, etc. The frequency of the clock signal generated when a predetermined control voltage is input changes. Therefore, in the second embodiment, the electronic timepiece 1 has accumulated operation time characteristics related to the accumulated operation time of the oscillation circuit 23 and the frequency of the clock signal generated when the predetermined control voltage is input to the oscillation circuit 23. The correction unit 222 has the information 251 (see FIG. 5), and updates the cumulative operation time characteristic information 251 using the frequency difference Δfv. The characteristic indicated by the cumulative operation time characteristic information 251 is a so-called aging characteristic. The control voltage generation unit 223 corrects the frequency of the clock signal of the oscillation circuit 23 by generating a control voltage that cancels the deterioration characteristic due to the accumulated operation time indicated by the updated accumulated operation time characteristic information 251. The second embodiment will be described below. In addition, about the element which an operation | movement and a function are the same as 1st Embodiment in each form and each modification illustrated below, the code | symbol used in 1st Embodiment is diverted and detailed description of each is abbreviate | omitted suitably Do.

B. 1. Outline of Electronic Watch 1 According to Second Embodiment FIG. 5 shows a configuration diagram of the electronic watch 1 according to the second embodiment. The electronic timepiece 1 further includes a storage unit 25 and a temperature sensor 26. Control unit 22 includes an accumulated operation time measurement unit 224.

  The storage unit 25 is a readable and writable non-volatile storage medium. The storage unit 25 is, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory). The storage unit 25 is not limited to the EEPROM and can be appropriately changed. The storage unit 25 includes accumulated operation time characteristic information 251 and temperature characteristic information 252.

The temperature sensor 26 measures the temperature of the oscillation circuit 23. The accumulated operation time measuring unit 224 measures an elapsed time from the time when the oscillation circuit 23 is incorporated into the electronic timepiece 1 and the operation starts. Therefore, the time measured by the accumulated operation time measuring unit 224 indicates the accumulated operation time of the oscillation circuit 23.
The accumulated operation time characteristic information 251 indicates the relationship between the accumulated operation time of the oscillation circuit 23 and the frequency of the clock signal generated when a predetermined control voltage is input to the oscillation circuit 23. The predetermined voltage is, for example, a voltage V0 that oscillates a clock signal of the reference frequency f0 when the cumulative operation time is zero. The accumulated operation time characteristic information 251 has two modes. The accumulated operation time characteristic information 251 in the first aspect indicates the relationship between the accumulated operation time of the oscillation circuit 23 and the frequency itself of the clock signal generated when the voltage V0 is input to the oscillation circuit 23. The accumulated operation time characteristic information 251 in the second mode represents the relationship between the accumulated operation time of the oscillator circuit 23 and the frequency error Δfe of the frequency f _VCO of the clock signal generated when the voltage V 0 is input to the oscillator circuit 23. Show. The frequency error Δfe (an example of “error of frequency of clock signal”) is a difference between the frequency f _{VCO of the} clock signal and the reference frequency f0. Hereinafter, the accumulated operation time characteristic information 251 is assumed to be the second aspect.
The frequency difference Δfv and the frequency error Δfe coincide in terms of the difference between the reference frequency f0 and the frequency f _{VCO of the} clock signal. However, to make the following description clearer, the difference specified by the specifying unit 221 is referred to as “frequency difference”, and the difference stored in the cumulative operation time characteristic information 251 and the temperature characteristic information 252 is referred to as “frequency error”. .
For example, the accumulated operation time characteristic information 251 is a clock signal generated when the voltage V0 is input to the oscillation circuit 23 for each of the accumulated operation times of one month, two months,..., One year,. The frequency error Δfe is shown. The frequency error Δfe indicated by the accumulated operation time characteristic information 251 is, for example, a value obtained by experiment for the same oscillation circuit as the oscillation circuit 23.
The temperature characteristic information 252 indicates the characteristic due to the temperature change of the crystal oscillator in the oscillation circuit 23. The temperature characteristic information 252 relates to the temperature that can be taken by the oscillation circuit 23 and the frequency of the clock signal generated when a predetermined voltage is input to the oscillation circuit 23. The predetermined voltage is, for example, a voltage V0. The temperature characteristic information 252 has two modes. The temperature characteristic information 252 in the first aspect indicates the relationship between the temperature that can be taken by the oscillation circuit 23 and the frequency itself of the clock signal generated when the voltage V0 is input to the oscillation circuit 23. Temperature characteristic information 252 in the second embodiment, the temperature oscillation circuit 23 can take, and the frequency error Δfe between the frequency f _VCO and the reference frequency f0 of the clock signal generated when the input voltage V0 to the oscillation circuit 23 Show the relationship between Hereinafter, the temperature characteristic information 252 is assumed to be the second aspect.
For example, the temperature characteristic information 252 is the frequency error Δfe of the clock signal generated when the voltage V0 is input to the oscillation circuit 23 for each of 10 ° C., 15 ° C., 20 ° C., 25 ° C., 30 ° C., 35 ° C. Indicates The frequency error Δfe indicated by the temperature characteristic information 252 is, for example, a value obtained by experiment for the same oscillation circuit as the oscillation circuit 23.

  The correction unit 222 updates the cumulative operation time characteristic information 251 on the basis of the frequency difference Δfv specified by the specifying unit 221 and the accumulated operation time of the oscillation circuit 23 at the time the specifying unit 221 specifies the frequency difference Δfv. Correct the frequency of the clock signal. A specific update example of the cumulative operation time characteristic information 251 will be described with reference to FIG.

FIG. 6 is a diagram showing an example of updating the cumulative operation time characteristic information 251. As shown in FIG. A graph 600 shown in FIG. 6 shows a frequency error Δfe corresponding to the cumulative operation time of the oscillation circuit 23. The accumulated operation time characteristic 601 shown in the graph 600 is a characteristic indicated by the accumulated operation time characteristic information 251 before being updated by the correction unit 222. The reason why the frequency error Δfe becomes other than 0 as time passes is that the desorption of dust to the quartz oscillator which occurs in the hermetically sealed container of the oscillation circuit 23, the environmental change due to some outgassing, or the oscillation circuit 23 Aging of the adhesive, etc. In the example shown in FIG. 6, at the time of manufacture, the frequency error Δfe = 0, but as time passes, the frequency error Δfe increases in the negative direction. More specifically, the accumulated operation time characteristic information 251 indicates that the frequency error Δfe0 _ti1 is obtained when the accumulated operation time is time ti1, and the frequency error Δfe0 _ti2 is obtained when the accumulated operation time is time ti2. There is.

  It is assumed that the specifying unit 221 specifies the frequency difference Δfv when the accumulated operation time is the first time. The correction unit 222 updates the frequency error Δfe in the first time of the cumulative operation time characteristic information 251 to the same value as the frequency difference Δfv. At this time, a value obtained by subtracting the frequency error Δfe before update from the frequency difference Δfv is stored. The correction unit 222 adds the stored value to the frequency error Δfe at times other than the first time of the cumulative operation time characteristic information 251.

A specific update example of the cumulative operation time characteristic information 251 will be described. It is assumed that the identifying unit 221 identifies the frequency difference Δfv _ti1 when the accumulated operation time is the time ti1. The correction unit 222 updates the frequency error Δfe0 _ti1 of the accumulated operation time characteristic information 251 at the time _ti1 to the frequency error Δfe _ti1 . The frequency error Δfe _ti1 is the same value as the frequency difference Δfv _ti1 . Furthermore, the correction unit 222 adds the frequency difference Δfv _{ti1 −the} frequency error Δfe 0 _ti1 to the frequency error Δfe of the accumulated operation time characteristic information 251 other than the time _ti1 . The accumulated operation time characteristic 602 shown in the graph 600 is the characteristic indicated by the accumulated operation time characteristic information 251 after the update. The accumulated operation time characteristic 602 is a characteristic in which the accumulated operation time characteristic 601 is moved in parallel by the frequency difference Δfv ti1 _−the frequency error Δfe 0 _ti1 . For example, the correction unit 222 _adds the frequency difference Δfv _ti1 -the frequency error Δfe0 _ti1 to the frequency error Δfe0 _ti2 of the accumulated operation time characteristic information 251 at the time _ti2, and updates the frequency error Δfe _ti2 as shown in FIG.

It returns to the explanation of FIG.
Control voltage generation unit 223 specifies frequency error Δfe _ti according to the current accumulated operation time indicated by accumulated operation time measurement unit 224, using updated accumulated operation time characteristic information 251. Further, control voltage generation unit 223 specifies temperature error Δfe _te according to the current temperature indicated by temperature sensor 26 using temperature characteristic information 252.
Then, control voltage generation unit 223 generates a control voltage so that frequency error Δfe _ti and frequency error Δfe _te are canceled, and outputs the generated control voltage to oscillation circuit 23. For example, control voltage generation unit 223 generates control voltage V0-.DELTA.Vti-.DELTA.Vte such that frequency error .DELTA.fe _ti and frequency error .DELTA.fe _te are canceled. The magnitude of the control voltage corresponding to the frequency error Δfe _ti is “−ΔVti”. Further, the magnitude of the control voltage corresponding to the frequency error Δfe _te is “−ΔVte”.

B. 2. Effects of Second Embodiment As described above, the correction unit 222 updates the cumulative operation time characteristic information 251 based on the frequency difference Δfv and the cumulative operation time of the oscillation circuit 23 at the time of specifying the frequency difference Δfv. , Correct the frequency of the clock signal. Thus, when time passes after the frequency difference Δfv is specified, the electronic timepiece 1 uses the updated cumulative operation time characteristic information 251 even when the standard radio wave is not received, and the frequency of the clock signal It becomes possible to correct the

C. Third Embodiment In the second embodiment, the correction unit 222 updates the cumulative operation time characteristic information 251, and the control voltage generation unit 223 cancels the deterioration due to the cumulative operation time indicated by the cumulative operation time characteristic information 251 after the update. The frequency of the clock signal of the oscillation circuit 23 is corrected by generating such a control voltage. On the other hand, in the third embodiment, the correction unit 222 updates the temperature characteristic information 252, and the control voltage generation unit 223 generates a control voltage such that the temperature change indicated by the updated temperature characteristic information 252 is cancelled. Thus, the frequency of the clock signal of the oscillation circuit 23 is corrected. The third embodiment will be described below. In addition, about the element which an operation | movement and a function are the same as 2nd Embodiment in each form and each modification illustrated below, the code | symbol used in 2nd Embodiment is diverted and detailed description of each is abbreviate | omitted suitably Do.

C. 1. Outline of Electronic Watch 1 According to Third Embodiment FIG. 7 shows a configuration diagram of the electronic watch 1 according to the third embodiment. The correction unit 222 updates the temperature characteristic information 252 based on the frequency difference Δfv specified by the specifying unit 221 and the temperature of the oscillation circuit 23 at the time when the frequency difference Δfv is specified by the specifying unit 221, and the frequency of the clock signal Correct the A specific update example of the temperature characteristic information 252 will be described with reference to FIG.

The figure which shows the example of an update of the temperature characteristic information 252 in FIG. 8 is shown. A graph 800 shown in FIG. 8 shows the frequency error Δfe corresponding to the temperature of the oscillation circuit 23. The temperature characteristic 801 shown in the graph 800 is a characteristic indicated by the temperature characteristic information 252 before correction by the correction unit 222. In the example shown in FIG. 8, according to the environment in which the electronic timepiece 1 is used, the frequency error Δfe = 0 at 25 ° C., and the frequency error Δfe increases in the negative direction as it deviates from 25 ° C. More specifically, the temperature characteristic information 252 shows that the frequency error Derutafe0 _te2 if the frequency error Derutafe0 _te1, and the temperature of the oscillation circuit 23 is at a temperature te2 when the temperature te1 of the oscillation circuit 23 There is.

  When the temperature of the oscillation circuit 23 is the first temperature, it is assumed that the specifying unit 221 specifies the frequency difference Δfv. The correction unit 222 updates the frequency error Δfe at the first temperature of the temperature characteristic information 252 to the same value as the frequency difference Δfv. At this time, a value obtained by subtracting the frequency error Δfe before update from the frequency difference Δfv is stored. The correction unit 222 adds the stored value to the frequency error Δfe at temperatures other than the first temperature of the temperature characteristic information 252.

It is assumed that the identifying unit 221 identifies the frequency difference Δfv _te1 when the temperature of the oscillation circuit 23 is the temperature te1. The correction unit 222 updates the frequency error Δfe0 _te1 at the temperature te1 of the temperature characteristic information 252 to the frequency error Δfe _te1 . The frequency error Δfe _te1 has the same value as the frequency difference Δfv _te1 . Furthermore, the correction unit 222 adds the frequency difference Δfv _{te1 −the} frequency error Δfe ₀ te ₁ to the frequency error Δfe at a temperature other than the temperature te 1 of the temperature characteristic information 252. The temperature characteristic 802 shown in the graph 800 is the characteristic indicated by the updated temperature characteristic information 252. The temperature characteristic 802 is a characteristic in which the temperature characteristic 801 is moved in parallel by the frequency difference Δfv te1 _−the frequency error Δfe ₀ te ₁ . For example, the correction unit 222 _adds the frequency difference Δfv _te1 − frequency error Δfe ₀ te ₁ to the frequency error Δfe ₀ te ₂ at time te 2 of the temperature characteristic information 252 and updates the frequency error Δfe _{te 2} as shown in FIG.

It returns to the explanation of FIG.
The control voltage generation unit 223 specifies the frequency error Δfe _ti corresponding to the current accumulated operation time indicated by the accumulated operation time measurement unit 224 using the accumulated operation time characteristic information 251. Further, the control voltage generation unit 223 specifies the frequency error Δfe _te according to the current temperature indicated by the temperature sensor 26 using the updated temperature characteristic information 252. The subsequent processing of the control voltage generation unit 223 is the same as that of the second embodiment, and thus the description thereof is omitted.

C. 2. Effects of the Third Embodiment As described above, the correction unit 222 updates the temperature characteristic information 252 based on the specified frequency difference Δfv and the temperature of the oscillation circuit 23 at the time of specifying the frequency difference Δfv, and the clock Correct the frequency of the signal. Thereby, the electronic timepiece 1 corrects the frequency of the clock signal using the updated temperature characteristic information 252 even when the standard radio wave is not received at a temperature different from the temperature at the time of specifying the frequency difference Δfv. It will be possible to

D. Modified Embodiments The above embodiments can be variously modified. The aspect of a specific deformation | transformation is illustrated below. Two or more aspects arbitrarily selected from the following exemplifications may be combined as appropriate within the range not mutually contradictory. In addition, about the element in which an effect | action or a function is equivalent to embodiment in the modification illustrated below, the code | symbol referred by the above description is diverted and detailed description of each is abbreviate | omitted suitably.

In the above embodiments, it is assumed that the frequency f _{VCO of the} clock signal is corrected each time the reception unit 21 receives a standard radio wave, but the present invention is not limited to this. For example, even if the reception unit 21 receives a standard radio wave, the frequency f _{VCO of the} clock signal may not be corrected each time, but may be intermittently corrected, for example, once in several times. Even in such a form, it is possible to improve the accuracy of the internal time as compared with the case where the frequency f _{VCO of the} clock signal is not corrected at all.

  In each of the above embodiments, the standard radio wave is JJY and the carrier frequency of JJY is 40 kHz, but it is not limited thereto. The above embodiments can be applied even if the frequency of the carrier wave of JJY is 60 kHz, and can be applied even if the standard radio wave is WWVB, DCF 77, MSF, BPC or the like.

  In each of the above embodiments, the frequency of the carrier wave of the standard radio wave is converted to the reference frequency f0, but the clock signal may be converted to the frequency of the carrier wave of the standard radio wave. However, since the exact frequency of the clock signal is unknown, the electronic watch 1 uses the NCO to multiply the frequency of the clock signal by (the frequency of the carrier wave of the standard radio wave / reference frequency f0) to specify the frequency difference Δfv You may Alternatively, in each of the embodiments described above, the carrier wave and the clock signal of the standard radio wave may be converted to a frequency different from the reference frequency f0 and the carrier wave frequency of the standard radio wave, and the frequency difference Δfv may be specified.

  In each of the above embodiments, the electronic timepiece 1 determines whether to correct the internal time using the TCO signal or to correct the internal time using the frequency difference Δfv according to the number of times the standard radio wave is received. Good. For example, the electronic timepiece 1 corrects the internal time using the TCO signal when the remainder obtained by dividing the number of times the standard radio wave is received by a predetermined natural number is 1, and when the remainder is not 1, the frequency difference Δfv It may be used to correct the internal time. The electronic timepiece 1 may correct the internal time using the frequency difference Δfv every predetermined period such as one week or one month, and may correct the internal time using the TCO signal during that time. Furthermore, the processing unit 24 acquires an operation signal output when the user operates the button 4-1, the button 4-2, or the button 4-3, and the processing unit 24 uses the TCO signal based on the operation signal. It may be determined whether to correct the internal time or to correct the internal time using the frequency difference Δfv. In addition, the processing unit 24 periodically corrects the internal time using the TCO signal, and processes the operation signal output when the user operates the button 4-1, the button 4-2, or the button 4-3. Once acquired, the internal time may be corrected using the frequency difference Δfv.

  In each of the above embodiments, the electronic timepiece 1 corrects the internal time using the TCO signal according to the time when the standard radio wave is received and the number of times the standard radio wave is received, or the internal time is calculated using the frequency difference Δfv. It may be determined whether to correct. For example, the electronic timepiece 1 corrects the internal time using the TCO signal when the standard radio wave is received for the first time in a certain month, and corrects the internal time using the frequency difference Δfv in the second and subsequent times. Good.

  In each of the above embodiments, the electronic timepiece 1 is not limited to the wristwatch shown in FIG. 1, but may be a clock, a clock or the like. Furthermore, the display method of the electronic timepiece 1 is not limited to the analog type shown in FIG. 1, but may be digital. When the display method of the electronic timepiece 1 is digital, the electronic timepiece 1 may display an image indicating that the correction is completed when the clock frequency is corrected.

  In each of the above-described embodiments, it can be considered as a computer program configured to cause the control unit 22 to function or a computer-readable recording medium having the computer program recorded thereon. The recording medium is, for example, a non-transitory recording medium, and may include, in addition to an optical recording medium such as a CD-ROM, any known recording medium such as a semiconductor recording medium or a magnetic recording medium. The present invention is also specified as a control method of the electronic timepiece according to each aspect described above.

  In each of the above-described embodiments, the control unit 22 may realize all or part of the elements realized by executing the program in hardware by an electronic circuit such as FPGA or ASIC, or the software and hardware It may be realized by cooperation with the wear. The control unit 22 may be a single electronic circuit or a plurality of electronic circuits. Although the internal time correction unit 242 describes that the processing unit 24 is realized by executing a program, the internal time correction unit 242 may be included in the control unit 22.

DESCRIPTION OF SYMBOLS 1 ... Electronic clock, 10 ... Time display part, 11 ... Hour hand, 12 ... Minute hand, 13 ... Second hand, 20 ... Storage part, 21 ... Reception part, 22 ... Control part, 221 ... Identification part, 222 ... Correction part, 223 ... Control voltage generation unit 224 cumulative operation time measuring unit 23 oscillation circuit 24 processing unit 241 TCO decoding unit 242 internal time correction unit 243 internal time clock unit 25 storage unit 251 Accumulated operating time characteristic information 252 temperature characteristic information 26 temperature sensor.

Claims (16)

A receiver that receives standard radio waves,
An oscillator circuit that generates a clock signal used to clock an internal time;
The oscillation is performed such that the frequency of the clock signal approaches the reference frequency determined according to the frequency of the carrier wave of the standard radio wave based on the frequency of the carrier wave of the standard radio wave received by the receiving unit and the frequency of the clock signal A control unit that controls the circuit;
An electronic watch characterized by including. In claim 1,
The control unit
An identifying unit that identifies a difference between the reference frequency and the frequency of the clock signal;
A correction unit configured to control the oscillation circuit based on the difference to correct the frequency of the clock signal to approach the reference frequency;
An electronic watch characterized by including. In claim 2,
The identification unit is
Identifying the difference based on a reference wave generated from a carrier wave of the standard radio wave and the clock signal;
An electronic watch characterized by In claim 3,
The identification unit is
A first phase difference between the reference wave and the clock signal at a first time, a second phase difference between the reference wave and the clock signal at a second time, and the first time difference from the first time Identifying the difference based on the time to time,
An electronic watch characterized by In any one of claims 2 to 4,
The correction unit outputs a control voltage based on the difference,
The oscillation circuit oscillates a clock signal of a frequency according to the control voltage.
An electronic watch characterized by In any one of claims 2 to 4,
The oscillation circuit oscillates a clock signal of a frequency corresponding to a control voltage,
A storage unit for storing accumulated operation time characteristic information related to an accumulated operation time of the oscillation circuit and a frequency of a clock signal generated when a predetermined control voltage is input to the oscillation circuit;
The control unit
The control voltage generation unit is configured to specify an error of a frequency of a clock signal according to an accumulated operation time of the oscillation circuit with reference to the accumulated operation time characteristic information, and generate the control voltage so as to cancel the error.
The correction unit is
The accumulated operation time characteristic information is updated based on the difference and the accumulated operation time of the oscillation circuit at the time of specifying the difference, and the frequency of the clock signal is corrected.
An electronic watch characterized by In any one of claims 2 to 4,
The oscillation circuit oscillates a clock signal of a frequency corresponding to a control voltage,
A storage unit storing temperature characteristic information related to a temperature that can be taken by the oscillation circuit and a frequency of a clock signal generated when a predetermined voltage is input to the oscillation circuit;
The control unit
The control voltage generation unit is configured to specify an error in the frequency of the clock signal according to the temperature of the oscillation circuit with reference to the temperature characteristic information, and generate the control voltage so as to cancel the error.
The correction unit is
The temperature characteristic information is updated based on the difference and the temperature of the oscillation circuit at the time when the difference is specified, and the frequency of the clock signal is corrected.
An electronic watch characterized by In any one of claims 2 to 7,
An internal time correction unit configured to correct the internal time based on the difference and the number of clock signals from the setting of the internal time based on a standard radio wave to the present time;
An electronic watch characterized by including. A control method of an electronic watch including a receiving unit for receiving a standard radio wave and an oscillation circuit for generating a clock signal used to measure an internal time,
The electronic watch is
The oscillation is performed such that the frequency of the clock signal approaches the reference frequency determined according to the frequency of the carrier wave of the standard radio wave based on the frequency of the carrier wave of the standard radio wave received by the receiving unit and the frequency of the clock signal Control the circuit,
A control method of an electronic watch characterized in that. In claim 9,
The electronic watch is
Identifying the difference between the reference frequency and the frequency of the clock signal;
The oscillation circuit is controlled based on the difference to correct the frequency of the clock signal to approach the reference frequency.
A control method of an electronic watch characterized in that. In claim 10,
The electronic watch is
Identifying the difference based on a reference wave generated from a carrier wave of the standard radio wave and the clock signal;
A control method of an electronic watch characterized in that. In claim 11,
The electronic watch is
A first phase difference between the reference wave and the clock signal at a first time, a second phase difference between the reference wave and the clock signal at a second time, and the first time difference from the first time Identifying the difference based on the time to time,
A control method of an electronic watch characterized in that. In any one of claims 10 to 12,
The electronic clock outputs a control voltage based on the difference;
The oscillation circuit oscillates a clock signal of a frequency according to the control voltage.
A control method of an electronic watch characterized in that. In any one of claims 10 to 12,
The oscillation circuit oscillates a clock signal of a frequency corresponding to a control voltage,
The electronic watch includes a storage unit storing cumulative operation time characteristic information related to the accumulated operation time of the oscillation circuit and the frequency of a clock signal generated when a predetermined control voltage is input to the oscillation circuit.
The electronic watch is
An error in the frequency of the clock signal according to the accumulated operation time of the oscillation circuit is specified with reference to the accumulated operation time characteristic information, and the control voltage is generated to cancel the error.
The accumulated operation time characteristic information is updated based on the difference and the accumulated operation time of the oscillation circuit at the time of specifying the difference, and the frequency of the clock signal is corrected.
A control method of an electronic watch characterized in that. In any one of claims 10 to 12,
The oscillation circuit oscillates a clock signal of a frequency corresponding to a control voltage,
The electronic timepiece includes a storage unit storing temperature characteristic information related to the temperature that can be taken by the oscillation circuit and the frequency of a clock signal generated when a predetermined voltage is input to the oscillation circuit,
The electronic watch is
An error in the frequency of the clock signal according to the temperature of the oscillation circuit is specified with reference to the temperature characteristic information, and the control voltage is generated to cancel the error.
The temperature characteristic information is updated based on the difference and the temperature of the oscillation circuit at the time when the difference is specified, and the frequency of the clock signal is corrected.
A control method of an electronic watch characterized in that. In any one of claims 10 to 15,
The electronic watch is
The internal time is corrected based on the difference and the number of clock signals from the setting of the internal time based on a standard radio wave to the present.
A control method of an electronic watch characterized in that.

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