JP5374415B2 - GPS reception clock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide accurate time quickly even in a recovered state immediately after power recovery where a power supply state is unstable in a GPS reception timepiece. <P>SOLUTION: In an unreceivable state, a control means 6 makes control to keep at least leap second information held by a nonvolatile memory 9, and reads leap second information when recovering to a receivable state, thus quickly completing reception after recovery of the receivable state in a short period of time and accurately displaying time. The unreceivable state includes an operation stop state because of a power drop and a power-saving state because of continuation of a non-power-generation state. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a GPS receiving clock, and more particularly to a GPS receiving apparatus that holds leap second information that is updated irregularly.

  GPS uses 32 satellites and is used in navigation systems, clocks, etc. as an information source from which the current position and time can be obtained anywhere in the world. Each GPS satellite is equipped with an atomic clock, which provides time information with extremely high accuracy. GPS time information includes TOW (TIME OF WEEK), week number, leap second information, and the like, and these can be calculated to obtain accurate time. On the other hand, in recent years, GPS receivers have been reduced in size and power saving, and wristwatch-type GPS reception watches are also being reduced in size to a practical size.

  Leap second information is indispensable for providing time information accurately to the user, while TOW is transmitted in a cycle of 6 seconds and a week number is transmitted in a cycle of 30 seconds. Since it has a period of 12.5 minutes, it takes a maximum of 12.5 minutes to obtain leap second information. Even though power saving is progressing, in the case of battery driving, continuous reception for more than 12 minutes causes an early voltage drop. As a technique for avoiding this, a technique for starting reception in accordance with the transmission timing of leap second information is disclosed (see Patent Document 1).

JP 2008-145287 A

In a wristwatch, the capacity of a power source is limited due to the fate of battery driving, and the battery capacity decreases with continued use, and the wristwatch cannot be used continuously.
In the case of a primary battery, the device stops due to the battery capacity being depleted. Some devices predict battery capacity in advance (by voltage measurement, etc.) and stop it.
Even when a power source such as a solar cell (solar battery) and a charging system power source comprising a secondary battery are used, the battery capacity is generally predicted in advance (by voltage measurement or the like) and stopped.
In such a stopped state, the data stored in the wristwatch including the time data is lost. This is the same when applied to a wristwatch type GPS reception clock.

When the wristwatch is reused from the stopped state, the power source capacity is recovered by battery replacement for the primary battery and recharging for the charging system power source, and the wristwatch is returned to a usable state.
However, as described above, since the time data is lost at the time of return, it is necessary to reset the time data in some form. In the case of a wristwatch type GPS receiving clock, the time can be set by receiving GPS information.
However, even in this case, there are the following problems.

(1) In order to obtain accurate time information from GPS information, time information including leap second information must be received. This is because the format of GPS information is time information that makes sense only when TOW and leap seconds are combined.
However, even if the technique described in Patent Document 1 is used, it takes 12.5 minutes at the longest to provide an accurate time including leap seconds.
For this reason, since the reception time becomes long, the current consumption is large, and when a charging system power supply is used, the power supply capacity may rapidly decrease and stop again.
In addition, since the reception time is long and the clock does not start operation, the user is distrusted.

(2) Leap second information is information that is updated only when there is a leap second adjustment at the timing of the end of June and the end of December, and is a low change frequency information that may be received at a very low frequency. . However, since there is no calendar information after returning from the stop, it is necessary to receive it without fail, and as a result, it is necessary to receive the leap second described in (1).

  An object of the present invention is to provide a GPS clock that can immediately obtain an accurate time or a time very close to an accurate time without going into the reception state for a long time when shifting from the reception-incapable state to the reception-enabled state. It is an object.

  The GPS reception clock according to the present invention includes at least receiving means 1 for receiving satellite information relating to time, processing means 2 for processing information received by the receiving means, timing means 3 for measuring time, and demodulation of the processing means. A time information generating means (6) for generating time information based on the signal and setting the time measuring means; a non-volatile storage means 9 for storing various data; and a control means 6 for performing various controls. The control means discriminates between a receivable state and a receivable state of the GPS reception clock, shifts to a receivable state according to a first predetermined condition, and changes from a receivable state to a second predetermined condition. When returning to the receivable state and shifting to the unreceivable state, the leap second information is stored in the nonvolatile storage means, and when returning from the unreceivable state to the receivable state, the leap second information is stored in the non-volatile storage. Means Characterized in that the read.

  In the present invention, the latest leap second information obtained in the receivable state is stored in the non-volatile storage means, so that the leap second is taken into account when returning from the unreceivable state to the receivable state. Can be provided.

  In the present invention, the control means does not acquire leap second information at the time of first reception after returning from the unreceivable state to the receivable state, and uses the leap second information read from the non-volatile storage means to Control is performed to generate information.

  In the present invention, when returning from the unreceivable state to the receivable state, time (TOW) / calendar information (week number) other than leap second information transmitted every 12.5 minutes is received, and leap second. By using the information stored in the non-volatile storage means, it is possible to provide an accurate time and calendar within a short time after the transition to the receivable state.

  In the present invention, the control means receives leap second information when the third predetermined condition is satisfied at the time of the first reception after returning from the unreceivable state to the receivable state, and acquires leap second information. When successful, it is controlled to generate time information based on the acquired leap second information.

  In the present invention, when the operation prohibition period is continued for a long time by receiving leap second information when there is a sufficient power supply voltage, the stored leap second information is different from the latest information. It is possible to provide an accurate time even in a certain situation.

In the present invention, a power supply unit that supplies power is provided, and the first, second, and third predetermined conditions are that a power supply voltage of the power supply unit reaches a predetermined value.

  In the present invention, the first, second, and third predetermined conditions are the first voltage (V1), the second voltage (V2), and the third voltage (V3), respectively, and V1 <V2 <V3. In the case of the relationship, consideration is given so that the voltage V1 does not become immediately below the voltage V1 immediately after the return to the receivable state by shifting to the receivable state at the voltage V2 higher than the voltage V1 that shifts to the receivable state. In addition, the voltage for receiving leap second information is set to a voltage V3 higher than the voltage V2, so that it becomes lower than the voltage V1 during the reception of the leap second information requiring a maximum of 12.5 minutes and shifts to the unreceivable state. However, the GPS reception clock is prevented from being used again.

  In the present invention, the power supply unit has a chargeable storage means and a power generation means for charging the power storage means, and the first and second predetermined conditions are values indicating a power generation state of the power generation means. And

  In the present invention, for example, when the power generation means is a solar cell and the low power generation state continues for several days as the first predetermined condition, and the power generation state is higher than the first predetermined condition as the second predetermined condition, If it is determined that there is a high possibility of being stored in a dark place under the first predetermined condition, the state shifts to the reception prohibited state, and then the reception prohibited state is canceled when the second predetermined condition is reached. With such a configuration, an effect of suppressing wasteful power consumption can be obtained by prohibiting reception in an environment where reception is not possible in a dark place, that is, indoors where a satellite cannot be seen.

  In the present invention, the first and second predetermined conditions are generated voltages of the power generation means, and the absolute value of the voltage corresponding to the thirty-second predetermined condition is the absolute value of the voltage corresponding to the first predetermined condition. It is characterized by being higher than or equal to the value.

  In the present invention, for example, the power generation means is a solar cell, the first predetermined condition is a voltage (V4) in a low power generation state, and the second predetermined condition is a voltage (V5) in a power generation state higher than the first predetermined condition. In the case of the relationship of V4 ≦ V5, when the generated voltage becomes V4 or less, the state is shifted to the reception prohibited state, and when the generated voltage becomes V5 thereafter, the reception prohibited state is cancelled. Thereby, hysteresis is provided in the return condition, and the return operation can be ensured.

  In the present invention, only time information is acquired at the time of the first reception when returning to a receivable state upon detection of a generated voltage that is equal to or higher than the second predetermined condition.

Compared with the stop state in which the clock is completely stopped, the timekeeping continues in the power saving state, so that the timekeeping time is not significantly different.
In the present invention, this is utilized, and only the TOW is received, so that even if the voltage is lowered (higher than the voltage at which it is stopped) due to the long-term non-power generation state, the signal is received for a long time. Therefore, normal use can be provided even after the reception prohibited state is released.

  In the present invention, as the leap second information, the current leap second, leap second update week, leap second update date, and leap second after update are stored, the week number is received at the time of reception, and the week number is successfully received. The update timing obtained from the received week number is compared with the update timing of the stored leap second information. If it is before the update timing, it is the current leap second, and after the update timing, the leap second after the update. And generating time information.

  In the present invention, it is possible to determine whether or not the update timing of the leap second information stored in the non-volatile storage means has passed by receiving the calendar information when shifting from the unreceivable state to the receivable state. Leap second correction at an appropriate timing becomes possible.

  In the present invention, at the time of production, default data of leap seconds is stored in the non-volatile storage means, and time information is created using the default data from the start of use until the first successful leap second reception. And

  In the present invention, even when there is an update of leap second information during storage for a stock item in which the timepiece has been assembled, the leap second information is updated by non-contact communication means or the like at the time of final shipment. By storing the information, the latest leap second information is always available at the time of shipment, so that an accurate time can be provided.

  According to the present invention, leap second information is held and stored when shifting from the receivable state to the unreceivable state, and held and stored when shifting from the unreceivable state to the receivable state. By reading out the leap second information, it is possible to obtain the leap second information after shifting to the receivable state, so even if it is not in the reception state for a long time, it is based on the read leap second information, or it is very close to the accurate time. It can provide time immediately.

It is a block diagram of the GPS reception clock concerning a 1st embodiment of the present invention. It is a flowchart which shows the content of operation | movement of the GPS receiving timepiece concerning the 1st form of this invention. It is a flowchart which shows the content of the voltage drop operation | movement of the GPS receiving timepiece concerning the 1st form of this invention. It is a flowchart which shows the content of the voltage return operation | movement of the GPS receiving timepiece concerning the 1st form of this invention. It is a state transition diagram which shows the state of the GPS receiving timepiece concerning the 1st form and 2nd form of this invention. It is a flowchart which shows the content of the voltage return operation | movement of the GPS receiving timepiece concerning the 2nd form of this invention. It is a flowchart which shows the operation | movement from production and shipment to the first reception of the GPS receiving timepiece concerning the 4th form of this invention. It is a flowchart which shows operation | movement of the GPS receiving timepiece concerning the 5th form of this invention.

  Hereinafter, preferred embodiments of a GPS reception timepiece according to the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment: Basic Embodiment]
<Circuit configuration>
First, an outline of a circuit configuration of a GPS reception clock 100 as an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of a GPS reception clock 100 according to the first embodiment of the present invention.
Reference numeral 1 denotes GPS receiving means for receiving a GPS signal transmitted from a GPS satellite at 50 bps and outputting a demodulated result. Reference numeral 2 denotes data processing means for receiving data from the GPS receiving means 1 and performing data processing. 3 is a time measuring means for measuring time, 4 is a display driving means for controlling display based on the output of the time measuring means, and 5 is a display means for displaying time.

6 is an output of a reception start command to the GPS receiving means 1, an arithmetic processing of information obtained from the data processing means 2, an output of time information to the time measuring means 3, a drive command to the display drive means 4, Control means for performing overall control within the GPS reception clock 100, such as a detection start instruction and a nonvolatile memory access instruction for the nonvolatile memory control means 8.

Reference numeral 7 denotes voltage detection means for detecting the voltage of the power supply unit 12, reference numeral 8 denotes nonvolatile memory control means for erasing, writing, and reading of a nonvolatile memory described later in response to an instruction from the control means 6, and reference numeral 9 stores various data. Non-volatile memory, 10 is a ROM (read only memory) that stores a control sequence of operations in the timepiece such as a control means, 11 is a RAM (random access memory), and 12 is a power supply unit that supplies power to the GPS reception timepiece.
It should be noted that a circuit configuration that is not relevant to the description of the present invention, such as an oscillator, is not shown, but a configuration necessary for the GPS reception clock 100 is included.

<Overview of operation>
Next, a schematic operation of the GPS reception clock will be described with reference to FIG.
The control means 6 outputs a command to start reception to the GPS receiving means 1 when the external time input from a switch (not shown) or the internal time of the GPS reception clock timed by the time measuring means 3 reaches a predetermined time, and the display means 5 A command is output to the display driving means 4 so that the reception start display is displayed (for example, the reception mark is turned on digitally).
The GPS receiving means 1 enters a receiving state, and performs processing necessary for demodulation such as satellite acquisition and phase synchronization. The demodulated signal is input to the data processing means 2, and it is determined whether or not the information necessary for the GPS reception clock, that is, the data related to the time in this embodiment can be received correctly. Output data.
The control means 6 calculates the year, month, day, hour, minute, and second based on the time data output from the data processing means 2 and outputs it to the time measuring means 3 and outputs a reception end command to the GPS receiving means 1 To do. Based on the time information of the time measuring means 3, the display driving means 4 updates the time information to the display means 5. If the satellite cannot be captured within a specified time from the start of reception or if reception is stopped due to external input, the control means does not update the time to the time measuring means 3 and sends a reception end command to the GPS receiving means 1. Output.

In the GPS reception clock 100, the voltage of the power supply unit 12 decreases with the progress of use. Since the GPS reception clock 100 cannot be controlled normally when the voltage drops, the control means 6 executes a process for stopping the clock when the voltage drops below a certain specified voltage.
FIG. 5 is a state transition diagram showing the operation state of the watch. When the voltage decreases, the operation state 200 is shifted to the operation inhibition state 300. Detailed operation will be described below.

The voltage detection means 7 detects the voltage of the power supply unit 12 and outputs the information to the control means 6 when the voltage is lower than a specified voltage, for example, the first predetermined voltage or lower.
The control means 6 receives the information about the voltage drop and outputs a display stop command to the display drive means 4 and also issues a command to the nonvolatile memory control means 8 to store the information inside the watch in the nonvolatile memory 9. In response to the command, the nonvolatile memory control means 8 stores necessary information inside the timepiece including the leap second information in the nonvolatile memory 9.
In addition to the leap second information, information such as an alarm, time zone, daylight saving time, and the like set by the user and information such as a stopped hand position in the case of a pointer type display clock are stored in the nonvolatile memory 9. Since the time and calendar change every moment even when the GPS reception clock 100 is stopped and stored, it does not make sense, so time information and calendar information are not stored.
When the writing is completed, the GPS reception clock 100 continues the operation prohibited state 300 until the voltage is restored, and the reception operation by the reception unit 1 and the time measurement by the time measurement unit 3 are not performed. The operation prohibition state 300 can also be said to be a reception impossible state.

After the stop, in the case of battery replacement or a rechargeable power source, when charging is performed and the voltage returns to the second predetermined voltage or higher, the GPS reception clock 100 is subjected to a power-on reset, and the operation prohibited state 300 is released. In FIG. 5, the voltage is restored and the state is shifted from the operation prohibited state 300 to the operable state 200.
After the suspension is released, when the voltage detecting means 7 detects the voltage and the control means 6 determines that there is a voltage at which the clock operation can be resumed, the control means 6 sends a read command of the data stored in the nonvolatile memory 9 to the nonvolatile memory control. Output to means 8. After reading, reception is started, and TOW, week number, leap second information, etc. are received. The operable state 200 is a receivable state.
Note that the first predetermined voltage and the second predetermined voltage may be the same or different. However, if they are different, the second predetermined voltage is set higher than the first predetermined voltage in consideration of system safety. The

<Basic reception operation>
Next, the reception processing operation will be described based on the flowchart of FIG. Note that the GPS transmission format is described in Patent Document 1 and the like and is well known, and is omitted here.

When the time manually received by the external switch or the time measured in the GPS reception clock reaches a specified time, the control circuit 6 outputs a reception start command to the GPS receiving means 1.
After the start of reception, the data processing means 2 determines whether or not the satellite is supplemented (ST1), and if it is determined that acquisition and demodulation are possible (ST1: Y), acquisition of information is started (ST2), and acquisition is performed. If it is determined that it cannot be performed, the reception ends (ST1: N).

When acquisition of information is started in ST2, first, TLM (TELEMETRY) information is detected in order to synchronize with transmission data, and if detection is possible, TOW is extracted.
When the time information can be extracted (ST2: Y), the process proceeds to detection of week number information (ST3).
If TLM information cannot be detected or TOW cannot be extracted as time information due to noise or the like (ST2: N), reception ends.

Similarly, when the week number information can be normally extracted (ST3: Y), the process proceeds to acquisition of leap second information (ST4). When the week number information cannot be obtained (ST3: Y), the reception is terminated.
When the leap second information has been successfully extracted (ST4: Y), the control means 6 calculates the display time (ST5), holds the received information in the RAM 10 (ST6), and calculates the time to the time measuring means 3 The display drive unit 4 causes the display unit 5 to display the update time.
If the leap second information could not be extracted (ST4: N), the reception is terminated.

In FIG. 2, the process is such that reception is not successful unless TOW, week number (WN), and leap second information (LS) cannot be extracted.
For example, when only the TOW is successfully received, the display time may be updated using the previously received week number and leap second information.

<Voltage drop (stop) process>
Next, processing at the time of voltage drop will be described based on the flowchart of FIG.
The GPS reception clock 100 periodically detects whether or not it is equal to or lower than a specified voltage (ST11). If it is equal to or higher than the specified voltage (first predetermined voltage) (ST11: N), it is determined that the voltage can operate normally, and the operation continues. When the voltage is lower than the specified voltage (first predetermined voltage) (ST11: Y), the process proceeds to a function stop process, and the control means 6 is nonvolatile in order to store the received leap second information in the nonvolatile memory 9. The volatile memory control means 8 executes erasure of the nonvolatile memory 9 and writes leap second information after erasure is completed (ST12).
When the writing is completed, the control means 6 outputs a display drive stop command to the display drive means 4, stops the display on the display means 5, and puts the entire timepiece into a stop state (ST13).
In the stop state, the GPS reception clock 100 does not resume operation until the voltage is restored.

<Voltage recovery (recovery) processing>
Next, processing at the time of voltage recovery will be described based on the flowchart of FIG.
In the stop state, when the battery is replaced or in the case of a rechargeable power source, charging is performed, and when the power supply unit 12 recovers to the operable voltage (second predetermined voltage) of the GPS reception clock 100, a power-on reset is executed. The GPS reception clock 100 starts operating.
At this time, in order to determine whether the voltage is equal to or higher than the specified voltage (second predetermined voltage), the control means 6 outputs a voltage detection command to the voltage detection means 7 as to whether the voltage is sufficiently operable (ST21). If the voltage is less than the specified voltage (ST21: N), the voltage detection is continued until the voltage becomes equal to or higher than the specified voltage.

When the voltage is equal to or higher than the specified voltage (second predetermined voltage) (ST21: Y), the control means 6 instructs the nonvolatile memory control means 8 to read the leap second information from the nonvolatile memory 9, and the readout is performed. Leap second information is stored in the RAM 11 (ST22).
In the case of a specification for manual reception start operation or automatic reception upon voltage recovery, the control means 6 outputs a reception start command to the GPS reception means 1 (ST23), and the data processing means 2 starts detection of received data To do.

First, it is determined whether or not the TOW can be extracted (ST24). If it cannot be extracted (ST24: N), reception is terminated, default data is set in the time and calendar (ST31), and the clock operation is started (ST30). At this time, the default data is, for example, 12:00 am on January 1, 2009.
If extraction is successful (ST24: Y), extraction of week numbers is started (ST25).
When the week number cannot be extracted (ST25: N), the reception is terminated and the calendar is set to default data (for example, January 1, 2009) (ST27), and the week number is extracted when extracted. A calendar is calculated from the information (ST26). Subsequently, the present time is calculated from the TOW acquired by reception and the leap second information read from the nonvolatile memory 9 (ST28), the received time information is held (ST29), and only the time information is corrected to measure time. 3 and the correction time is displayed on the display means 5 via the display driving means 4 (ST30).

<Effect of the first embodiment>
As described above, according to the present embodiment, there is an effect that it is possible to provide a time close to an accurate or extremely accurate time in a short time, at least for a time when the voltage drops and stops from a stopped state. can get.

<Modification of the first embodiment>
This embodiment has been described as an example of receiving TOW and week numbers.
However, since it takes about 30 seconds at the maximum to acquire the week number, there may be a heavy load depending on the power state after the return, and the user may feel that the user has been waiting for a long time.
Therefore, when it is desired to display the accurate time in a shorter time after the power is restored, it is desirable to use the leap second information stored as TOW without receiving the week number.
In this case, it is possible to display an accurate time within a few seconds after the start of reception.
Note that the execution / non-execution of week number reception may be controlled by the power supply voltage as in the second embodiment.

[Second Embodiment: Receive Leap Second at Return]
A second embodiment according to the present invention will be described with reference to FIG. In the present embodiment, as in the first embodiment, the GPS reception timepiece 100 is used, the description of the same configuration as in the first embodiment is omitted, and different portions are mainly described.

In the second embodiment, a leap second is acquired at the time of the first reception after return, and it is assumed that more accurate time information is obtained.
6 are the same as those in FIG. 6 for the same processing as the step number in FIG. The power supply unit 12 will be described as a charging system power supply.

Steps up to ST28 are the same as in FIG.
When the TOW and week number extraction processing is completed and the calculation of time and calendar is completed using the stored leap second information (ST28), voltage detection of the power supply unit 12 by the voltage detection means 7 is executed again (ST28). ST40). The execution of ST40 voltage detection is for the following reason.

In the case of the return from the stopped state in ST21, the battery capacity (second predetermined voltage) is assumed assuming that the TOW and the week number alone are executed for a short time. As a result, unnecessary charging is unnecessary, and the user can use the watch at an early stage.
On the other hand, as described above, reception of leap seconds requires a reception time of up to 12.5 minutes, which increases the burden on the power supply unit 12, and the return permission level from the stop may not necessarily be sufficient. Is expensive.
Therefore, in ST40, the determination at the third predetermined voltage higher than the specified voltage in ST21 is performed. When it is determined that the voltage is equal to or lower than the specified voltage (ST40: N), the process waits until the voltage becomes equal to or higher than the specified voltage.
If the voltage is not more than the specified voltage (third predetermined voltage) even after waiting for a predetermined time, the process proceeds to ST29.

  When a voltage equal to or higher than the specified voltage is detected (ST40: Y), extraction of leap second information is started (ST42). If the leap second cannot be extracted (ST42: N), the reception is terminated, and the time and calendar calculated in ST28 (and the elapsed time required for ST40, ST41, ST42 are also added) are output to the time measuring means 3 and extracted. The stored TOW and week number are stored in the RAM 11 (ST29), the time and calendar are displayed on the display means 5 via the display driving means 4, and the clock operation is started (ST30).

  When the leap second can be extracted (ST42: Y), the display time is calculated from the extracted TOW, week number, and leap second information (ST43), the extracted information is stored in the RAM 11 (ST29), and the corrected time is corrected. Then, the calendar is output to the time measuring means 3, the time and calendar are displayed on the display means 5 via the display driving means 4, and the clock operation is started (ST30).

<Effect of the second embodiment>
According to this embodiment, when the return is received, the leap second is also received if there is a margin in the power supply voltage (= battery capacity), so that more accurate time can be generated at the time of return.
Also, by setting the permitted power supply voltage (third predetermined voltage) for receiving leap second information higher than the voltage (second predetermined voltage) when receiving only the TOW and week number, only the TOW and week number are received. Return to permit reception can be realized at an early stage.

<Modification of Second Embodiment>
In this embodiment, the voltage detection is continued until the leap second reception is possible, and the clock operation is not performed. However, the present invention is not limited to this, and the TOW and the week number are stored when they are extracted. The clock operation may be started using the leap second information, and the leap second information may be received when the voltage necessary for the leap second reception is reached during the clock operation.

[Third embodiment: behavior in a power saving state]
A third embodiment according to the present invention will be described with reference to the drawings. Also, the description of the same configuration as that of the first embodiment is omitted, and different portions will be mainly described.
The third embodiment is an embodiment of a GPS reception timepiece that has a charging system power supply by power generation means and shifts to a power saving state depending on the presence or absence of power generation.

The power storage means (secondary battery) of the charging system power supply often has a smaller capacity than the primary battery, and a power saving function is required to extend the life. Further, the non-power generation state is often not used by the user, and in such a case, it is wasteful to operate as usual.
Therefore, the function of shifting to a power saving state that restricts the function when non-power generation is continuously detected for a predetermined period or longer is useful for the charging system power supply, and the same applies to the GPS reception clock.
In an electronic timepiece with a reception function, in the power saving state, the internal clock keeps counting, and the time display means and the reception means are often stopped to save power.
The same control is effective for the GPS reception clock.

When a non-power generation state continues for a period when a reception prohibition command by an external input (not shown) or a power generation means (not shown) constituting the power supply unit 12 is periodically detected by the control means 6, the control means 6 Activate the power save function.
In the power saving state, output of a reception start command to the GPS receiving means 1 is prohibited, and the display means 5 is stopped (display of the needle is stopped, LCD display is turned off, etc.) for the display driving means 4. Further, while the received leap second information is held in the RAM 11, the control unit 6 outputs a command to the nonvolatile memory control unit 8 to store the leap second information in the nonvolatile memory 9.
FIG. 5 shows an operation state. When a non-power generation (power generation voltage equal to or lower than the first predetermined voltage) state continues for a certain period or longer, the operation state shifts to the operation prohibition state.
It is to be noted that the operable state is the receivable state and the operation prohibited state (power save) state is the unreceivable state, as in the first embodiment.

When the control means 6 detects an external input (not shown) for canceling the power save, or a power generation means (not shown) generating power (a power generation voltage equal to or higher than the second predetermined voltage), the control means 6 cancels the power saving function. When the power saving function is canceled, a display return command is output to the display driving means 4 to cause the display means 5 to be in a display state. Furthermore, reception is performed at any timing before, during or after the return of display.
FIG. 5 shows an operation state. When an external input for canceling power save or power generation is detected, the operation prohibition state 300 shifts to the operation enable state 200.

Since the timekeeping continues even during the power save function, there is no deviation of the calendar, depending on the accuracy, and there is a high possibility that only the time is shifted. Further, since it is sometimes necessary to use the GPS reception clock immediately after canceling the power save, it is desirable that the reception should be completed in a short time.
Therefore, only TOW is received after canceling the power save, and the week number and leap second information are not received. Specifically, the control unit 6 issues a command to the data processing unit 2 so that only TOW data is extracted. After successful reception, the current time is calculated from the received TOW and the stored leap second information, the time information of the time measuring means 3 is updated, and displayed on the display means 5 via the display driving means 4.

<Effect of the third embodiment>
As described above, according to the present embodiment, the leap second that can be received only by TOW is used by using the stored leap second information, so that an accurate time or a time close to an extremely accurate time can be obtained even immediately after canceling the power save. The effect which can be provided is acquired.

In addition, by selecting only TOW as the extraction target, even if the voltage drops (higher than the voltage at which it stops) due to long-term power saving, it will not be in a state of receiving for a long time, so it will not stop. An effect that can be used in a normal state even after canceling the power save is obtained.

<Modification of the third embodiment>
In the present embodiment, only TOW is extracted. However, the present invention is not limited to this. If the stopped period is short, only TLM is extracted to correct the time, or the calendar may shift. If so, it may be received up to a week number that can be extracted in less than one minute.

[Fourth Embodiment; Leap Second Default Data Writing in Production]
In the above three embodiments, an example has been described in which leap second information is written in the nonvolatile memory at the time of transition to the unreceivable state.
By the way, there are many cases where the GPS radio wave reception environment is not always good at the time of stocking after shipment or display at a store. In such a case, it is not always preferable to acquire leap second information with a long reception time for TOW and week numbers with a relatively short reception time.
However, the time information cannot be accurate unless the leap second information is added to the TOW.
Therefore, the GPS reception clock 100 writes default data of leap second information at the time of shipment in the nonvolatile memory 9, and uses this default data to create and display time information until the leap second reception is successful. preferable.
This makes it possible to provide time information with relatively high accuracy immediately after shipment.

The default data is written by using an inspection / adjustment terminal or the like from the outside of the watch when the GPS receiving watch 100 is produced. The writing method may be a contact method, but the non-contact method is more convenient because writing can be performed in a completed clock state.
There are various types of non-contact writing methods. For example, when a step motor is used as the display driving unit 4, it is more preferable to use communication via the motor because no components are added.

An outline from production / shipment to the first reception will be described with reference to the flowchart of FIG.
FIG. 7 is a flowchart showing operations from production / shipment to the first reception of the GPS reception timepiece according to the fourth embodiment of the present invention.
After completion of the watch (ST100), default data of leap second information is written in the nonvolatile memory 9 by non-contact communication using, for example, a motor coil (ST101). As default data, the latest leap second information at the time of production is written.

After a system reset (ST102) for starting the completed clock, the leap second (LS) of the nonvolatile memory 9 is read and written to the RAM 11 (ST103).
Thereafter, only the TOW and week number are received (ST104). The reason for not receiving the leap second is to consider shortening the shipping process.
If reception fails (ST105: N), default time / calendar information is written (ST107).
If reception is successful (ST105: Y), a time obtained by adding default leap second information to the received time information is created and displayed.

  Thereafter, the GPS reception clock receives leap seconds in the actual use state. When the reception of the leap second is successful, the received leap second information is stored in the clock (for example, the RAM 11) instead of the default data. Thereafter, time information data is created from the received leap second information. Also, the received leap second information is stored in the nonvolatile memory 9 when the state is shifted to the reception disabled state.

<Effect of the fourth embodiment>
As described above, the default data of leap second information at the time of shipment is written in the non-volatile memory 9, so that accurate time information can be created and displayed even in an environment where reception is difficult such as in stock or store display. It becomes.

[Fifth embodiment: Leap second update week storage]
The fifth embodiment is an embodiment in which the correction method is changed according to the stored leap second information in the first to fourth embodiments.
The leap second information of the GPS transmission signal includes the current leap second, the leap second update week, the leap second update date, and the leap second after the update.
As the leap second information stored at the time of stoppage or production, some or all of the above four types of information may be stored, but in the present embodiment, all are stored.

The operation will be described with reference to the flowchart shown in FIG.
First, it is determined whether or not the week number has been successfully received when receiving the voltage (ST200). If it has failed (ST200: N), the leap second update time cannot be determined. Using the current leap second, the time is generated (ST204).

If the week number has been successfully received (ST200: Y), the stored update week and update date are compared (ST201). If the update timing has passed (ST202: Y), the time is generated using the updated leap second (ST203), and if it is before the update timing, the current leap second is used to generate the time (ST204). .
With this configuration, it is possible to provide a time that is more accurate than the current leap second that has been stored.

[Other variations]
Although the first to fourth embodiments have been described above, the following modifications may be made to the respective embodiments.

(1) In this embodiment, TOW, week number, and leap second information are targeted for extraction, but in addition to these, the sub-frame ID, parity, etc. may be extracted for ensuring the reliability of received data. The target may be reduced.

(2) In the fifth embodiment, the current leap second, leap second update week, leap second update date, and all leap second information after the leap second are stored. However, the fifth embodiment is adopted. If not, only some leap second information may be stored.
As a result, the capacity of the nonvolatile memory 9 can be reduced.

(3) Although details of the display are not touched in the present embodiment, the display may be any one of means capable of constituting a display such as a pointer type, LCD, LED, or a combination of a plurality of means.

(4) The configuration of the present invention may be a random logic, a microprocessor having a CPU, or a combination of both.

(5) In the present embodiment, the information to be written in the nonvolatile memory 9 is leap second information. However, the present invention is not limited to this, and positioning information obtained by reception, information on the clock such as time zone setting, alarm time, daylight saving time setting, etc. May be stored. In particular, the time zone is effective because it is not necessary to set the zone again when the time zone is in the same zone when the clock is stopped and when the voltage is restored.

(6) In the present embodiment, the voltage for shifting from the operable state to the disabled state and the voltage for shifting from the disabled state to the operable state are the same. However, the present invention is not limited to this, and different voltages may be used.

(7) Further, in this embodiment, the two states of the operation enable state and the operation prohibition state are set according to the voltage. However, the present invention is not limited to this. There may be a state where the function is limited but the function is restricted but the clock is operated.

(8) The power supply unit 12 may be a primary battery or a secondary battery. Further, as a power generation means in the case of a secondary battery, a solar battery, automatic winding, thermoelectric power generation, or any combination or combination of these It doesn't matter.

(9) In this embodiment, the clock operation is started after the reception operation. However, the present invention is not limited to this, and TOW, week number, leap second information, etc. are sequentially received and updated after the clock operation is started. For example, there is no stress that the user waits until the time is displayed after the voltage is restored.

DESCRIPTION OF SYMBOLS 1 GPS receiving means 6 Control means 7 Voltage detection means 8 Non-volatile memory control means 9 Non-volatile memory 12 Power supply part

Claims (10)

Receiving means for receiving satellite information about at least time;
Processing means for processing the information received by the receiving means;
A time measuring means for measuring time;
Time information generating means for generating time information based on the demodulated signal of the processing means and setting the time measuring means;
Non-volatile storage means for storing various data;
Control means for performing various controls;
In a GPS reception watch having
The control means discriminates a reception enabled state and a reception disabled state of the receiving means of the GPS reception clock,
Due to the first predetermined condition, it shifts to a reception impossible state,
Due to the second predetermined condition, it returns from the unreceivable state to the receivable state,
After the transition to the unreceivable state, the leap second information is stored in the nonvolatile storage means,
A GPS reception timepiece which reads leap second information from the non-volatile storage means when returning from a non-receivable state to a receivable state. The control means includes
Control to generate time information using the leap second information read from the non-volatile storage means without acquiring the leap second information at the first reception after returning from the unreceivable state to the receivable state. The GPS reception timepiece according to claim 1. Having a power supply for supplying power,
It said first, second predetermined condition GPS receiver clock according to any one of claims 1 to 2, wherein the power supply voltage of the power supply unit is to reach a predetermined value. The control means, at the time of the first reception after returning from the unreceivable state to the receivable state,
Furthermore, the leap second information is received when the third predetermined condition is satisfied,
If successful leap second information acquisition, GPS receiver clock according to control any one of claims 1 to 3, characterized in that to generate the time information by the acquired leap second information. The third predetermined condition is that the power supply voltage of the power supply unit has reached a predetermined value,
5. The GPS receiving timepiece according to claim 4, wherein an absolute value of a power supply voltage corresponding to the third predetermined condition is higher than an absolute value of a voltage corresponding to the second predetermined condition. The power supply unit has a chargeable power storage means and a power generation means for charging the power storage means,
6. The GPS reception timepiece according to claim 1, wherein the first and second predetermined conditions are values indicating a power generation state of the power generation means. The first and second predetermined conditions are power generation voltages of the power generation means,
The absolute value of the voltage corresponding to the second predetermined condition is
The GPS reception timepiece according to claim 6, wherein the GPS reception timepiece is higher than or equal to an absolute value of a voltage corresponding to the first predetermined condition. 8. Only time information is acquired at the time of the first reception when returning to a receivable state upon detection of a generated voltage that is equal to or higher than the second predetermined condition. 9. GPS reception clock. As the leap second information, the current leap second, leap second update week, leap second update date, leap second after update are stored,
Receive the week number when receiving,
Update timing obtained from the received week number when the week number is successfully received,
Compare the update timing of the stored leap second information,
If the current leap second before the update timing,
The GPS reception clock according to any one of claims 1 to 8, wherein time information is generated in a leap second after the update timing. During production, default data of leap seconds is stored in the nonvolatile storage means,
10. The GPS reception clock according to claim 1, wherein time information is created using the default data from the start of use until the first successful leap second reception.

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